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An international clinical trial, is investigating whether infrared light can improve symptoms of Parkinson's disease. The experimental results, based on preclinical studies, indeed suggest that brain illumination in the near infrared is likely to slow down this neurodegenerative disease.

Hamilton, Mitrofanis and others had previously reported that wearing headphones equipped with infrared LEDs improved quality of life, although it did not have much effect on motor symptoms.

A medical device system (called Ev-NIRT) has been developed by the French scientists and Boston Scientific Corporation, for intracerebral illumination at 670 nm of the black substance pars compacta (SNpc), and will be tested in this pilot study.

Researchers will assess the feasibility and tolerance of surgery and brain illumination using the Ev-NIRT medical device, in a group of 7 patients with Parkinson's disease in whom the innovative medical device will be implanted. The patients will be followed for 4 years. The device will emit pulses at a wavelength of 670 nm for one minute, with a periodicity of 150 Hz. This burst of pulses will be followed by five minutes of rest. enter image description here

The team, led by neurosurgeon Alim-Louis Benabid of the Clinatec Institute, hopes that exposing this area of ​​the brain to infrared light will protect cells from death. Benabid, along with Pierre Pollak, are the pioneers who developed deep brain stimulation (DBS) in 1987. DBS works by sending electrical impulses into the brain. This invention has changed the lives of thousands of patients, but it has long term side effects.

About ten years ago, John Mitrofanis, a neuroanatomist at the University of Sydney, spent a year studying DBS with Benabid with the aim of creating a similar concept, but using infrared light. Mitrofanis was inspired by infrared headsets, used in the Parkinson's community. enter image description here

Benabid and Mitrofanis, however, felt that light from outside the skull would not penetrate deep enough and that an implantable device had to be created. In 2017, in collaboration with researcher Cécile Moro, they injected 20 macaques with a neurotoxin present in certain recreational drugs (MPTP) and known to cause the symptoms of Parkinson's disease. Scientists exposed nine macaques to near infrared in the midbrain region using an implanted device.

The French study will follow 14 patients with early-stage Parkinson's disease for 4 years, seven of whom will be treated periodically with 670 nanometer pulses of light delivered to the brain via a thin laser diode cable. The other seven patients will not be operated on; an ethics review committee has in fact decided not to subject them to surgery without the possibility of benefit.

Some Parkinson's researchers are skeptical. No one has shown why exposure to infrared should have an effect on cells that never see daylight. Neurons do not have a chlorophyll-based metabolism. Much of the encouraging results seen so far may be the result of the placebo effect, skeptics say.

There are three main hypotheses to explain how photomodulation works.

  • The first recalls that molecules sensitive to light in the body called chromophores are excited by photon stimulation. We now know that hemoglobin, myoglobin and COX are the only 3 chromophores in mammalian tissues capable of absorbing near infrared light (wavelength 600 to 900 nm). However, there is no clear mechanism of action linking these chromophores to the increased ATP synthesis which is observed under light stimulation.

  • The second hypothesis explains that the production of mitochondrial energy is the effect of a reduction in the intra-mitochondrial viscosity of water induced by the near infrared. the reduction in near infrared mediated viscosity decreases the friction that opposes the rotation of ATP synthase and results in a "smoother" rotation of the ATP synthase machinery. This theory is supported by the fact that increases in cellular ATP level are immediate after near infrared stimulation.

  • A third hypothesis suggests that the photoabsorbent pyropherophorbide-a (P-a) metabolite of dietary chlorophyll may facilitate light energy production processes in animals. In the experiments, ATP levels increased only in groups where P-a and near infrared light were co-administered, and not in those where P-a or near infrared were administered in isolation. Given the multiplicity of these competing theories, it is possible that the near infrared exerts its modulatory effects through several mechanisms instead of just one.

The main aim of this new clinical study is to prove that the implant is safe, says Benabid, but the researchers will also assess the progression of the disease. “This must lead to a great improvement,” he says. "There would be no reason to have extensive surgery for only slight improvement."

The major problem with all neuroprotection trials in Parkinson's disease is that diagnosis appears to occur after more than 50% of the dopamine-producing cells have disappeared. Unless the improvement is huge, the signal will be too weak to be detected.

The team will also be looking for clinical benefits. But because researchers assess symptoms of Parkinson's disease by observing patients performing specific tasks, the assessments are largely subjective and symptoms vary over time; everyone has good days and bad. Since the control group will not undergo surgery, it will be particularly difficult to rule out placebo effects.

Amyotrophic lateral sclerosis is a non-cell autonomous disease, and motor neuron degeneration is modulated by intracellular and intercellular damages. Or at least this is what tells some scientists, indeed there is an abundance of proposal for ALS etiology and no consensus.

Another dissension point between ALS scientists is if the disease starts in the brain, or in a muscle. The former is the mainstream hypothesis. Both camps have proven again and again that their proposal was the right one.

A third mystery is that scientists almost never bothered to explore the most obvious manifestation of ALS: The muscle wasting.

With the amelioration of tools' performance, scientist's attention is turning to extra cellular vesicles.

Extra cellular vesicles

In the Central Nervous System (CNS), intercellular crosstalk happens among neurons, between neurons and glia or cells of the innate immune system, through different modalities, involving the release into the extracellular space of molecules such as neurotransmitters, neurotrophic factors, metabolites, and mutant proteins encapsulated or not in vesicles.

C9orf72, which presents aberrant hexanucleotide (GGGGCC) expansion in the non-coding region in ALS patients, regulates vesicle trafficking. Other proteins such as SOD1, TDP-43 or FUS are found in vesicles in ALS.

Where we discuss of muscles

Although much less studied than for motor neurons, abnormalities have been also described in skeletal muscle from ALS patients.

Accumulation of misfolded mutant proteins is observed in skeletal muscle.

In line with the pivotal role of defective mitochondrial respiratory chain and oxidative stress in ALS skeletal muscle, increasing levels of PGC‐1α, a transcription coactivator that promotes mitochondrial biogenesis, can improve muscle function even at late stages of the disease.

Skeletal muscle is a major site of glucose storage in the form of glycogen, which is transformed into ATP through glycolysis. The dysfunction of fast‐twitch type IIb myofibres in ALS is consistent with glucose intolerance and insulin resistance reported in ALS patients.

Myofibres from transgenic mice over expressing wild‐type TDP‐43 show impaired insulin‐mediated glucose uptake.

Does muscles kill motor neurons? In ALS, muscles are supposed to die from inactivity as motor neurons do not anymore activate them. A publication on MedRxiv proposes that it is actually the other way round: Muscles kill motor neurons. After all it is well known that many ALS patients were having intense sport activities. And an ALS-like phenotype was observed in mice when exogenous human mutant SOD1 expression was restricted to the skeletal muscle.

The authors of the pre-print, Laura Le Gall, Stephanie Duguez, Pierre Francois Pradat and colleagues, recall that pathological proteins have been identified in circulating extracellular vesicles of sporadic ALS patients. So they hypothesized that muscle vesicles may be involved in ALS pathology.

An accumulation of multivesicular bodies was observed in muscle biopsies of 27 sporadic ALS patients.

Study of muscle biopsies and biopsy-derived denervation-naïve differentiated muscle stem cells (myotubes) revealed a consistent disease signature in ALS myotubes, including intracellular accumulation of exosome-like vesicles and disruption of RNA-processing.

Compared to vesicles from healthy control myotubes, when administered to healthy motor neurons the vesicles of ALS myotubes induced shortened, less branched neurites, cell death, and disrupted localization of RNA and RNA-processing proteins. enter image description here

This article may revolutionize the understanding of ALS' etiology.

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This book retraces the main achievements of ALS research over the last 30 years, presents the drugs under clinical trial, as well as ongoing research on future treatments likely to be able stop the disease in a few years and to provide a complete cure in a decade or two.

The insulin signaling pathway plays a crucial role in regulating the growth and metabolism of neurons. Deregulation of IGF-R signaling has been linked to a variety of neurodegenerative diseases such as Alzheimer's, Parkinson's and Huntington's disease.

However, the role of insulin signaling in C9orf72 ALS / FTD is not yet clear. A positive correlation of the incidence of ALS with early-onset type 1 diabetes has been reported, and a decrease in insulin and IGF-1 in the blood and cerebrospinal fluid of patients with ALS, although the relevance of these findings to disease progression is unclear.

Intrathecal administration of IGF-1 improved motor performance, delayed disease onset, and prolonged survival in the SOD1G93A mouse model of ALS. However, three clinical trials of IGF-1 administered subcutaneously in ALS have reported conflicting results. The contradictory result of these trials may be due to insufficient administration of drugs to the brain and spinal cord and the fact that ALS has heterogeneous genetic risk factors.

Atilano, Isaacs, Partridge, and colleagues have shown in a recent article that insulin/IGF signaling is reduced in C9orf72 fly models using adult brain RNA sequencing. They further demonstrated that activation of insulin/IGF signaling can attenuate several neurodegenerative phenotypes in flies expressing expanded G4C2 repeats or the toxic dipeptide repeat protein poly-GR.

Poly-GR levels are reduced when components of the insulin/IGF signaling pathway are genetically activated in diseased flies, suggesting a rescue mechanism. This effect on poly-GR levels was confirmed in a mammalian cell model. Modulation of insulin signaling in mammalian cells also lowers poly-GR levels. Remarkably, the systemic injection of insulin improves the survival of flies expressing G4C2 repeats. Their data suggest that modulation of insulin/IGF signaling may be an effective therapeutic approach against C9orf72 ALS/FTD.

PTEN acts as a tumor suppressor gene through the action of its protein phosphatase product. This phosphatase is involved in the regulation of the cell cycle, preventing cells from growing and dividing too quickly. It is a target of many anticancer drugs. Pten reduction has also been reported to reduce the toxicity of C9orf72 repeats expressed in a mammalian cell line, again in agreement with the results described by scientists and the potential therapeutic benefit of modulating this pathway. It is also interesting to note that the process of brain aging has been linked to decreased insulin signaling as well as impaired insulin binding, which may partly explain why aging is a problem. risk factor for the disease.

The authors found that intrathoracic insulin administration prolonged the survival of flies expressing G4C2 repeats. Although robust, the lengthening of the lifespan was relatively modest, which could be explained by the transient nature of the insulin treatment. Insulin and IGF-1 ligands have already been tested in neurodegenerative diseases.

Overall, the researchers' study suggests that modulation of the insulin / IGF signaling pathway could be an effective therapeutic intervention against hexanucleotide repeat extension associated with C9orf72 neurodegenerative diseases, with InR being a genetic modifier. It will be interesting in the future to study the need for downstream effectors of insulin signaling in the rescue of toxicity. It is important to note that in the Drosophila, there is a single insulin-like system that has the dual function of insulin / IGF signaling; thus, the mechanism of toxicity described in the researchers' model could also be linked to IGFs. Therefore, it will be important to test whether treatment with insulin or IGF can save the survival of other C9orf72 ALS / FTD vertebrate model organisms.

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This book retraces the main achievements of ALS research over the last 30 years, presents the drugs under clinical trial, as well as ongoing research on future treatments likely to be able stop the disease in a few years and to provide a complete cure in a decade or two.

It was found in 2009 that toxicity of SOD1 is secondary to a gain of toxic function rather than a loss of enzymatic function of the SOD1 enzyme, thus reducing levels of the mutant protein was predicted to slow progression in SOD1-linked ALS. Tofersen (formerly known as BIIB067), is an antisense oligonucleotide designed for adults with a confirmed superoxide dismutase 1 (SOD1) genetic mutation, a subtype of familial ALS that makes up 2 percent of all ALS cases. 

As reducing levels of the mutant protein is predicted to slow progression in SOD1-linked ALS, this antisense oligonucleotide mediates the degradation of superoxide dismutase 1 (SOD1) messenger RNA. As there is less SOD1 mRNA, there is less production of the SOD1 protein. This is not without risks in itself, SOD1’s role is to protect against anti-oxidants which are the normal by-product of cellular respiration.

Tofersen was developed in a long time partnership between Biogen and Ionis Pharmaceuticals.  With the time doses went from 3mg up to 100mg. They conducted a phase 1-2 ascending-dose trial evaluating Tofersen in adults with ALS due to SOD1 mutations. In each dose cohort (20, 40, 60, or 100 mg), participants were randomly assigned in a 3:1 ratio to receive five doses of Tofersen or placebo, administered intrathecally for 12 weeks.  The results were presented in July 2020.

The results were encouraging, but as for any ALS trial they are anything but stellar. Lumbar puncture-related adverse events were observed in most participants. Among participants who received Tofersen, one died from pulmonary embolus on day 137, and one from respiratory failure on day 152; one participant in the placebo group died from respiratory failure on day 52.

48 participants received all five planned doses. The technical indicators where better for participants having the higher doses. Patients taking the highest dose of Tofersen saw their ALS Functional Rating Scale score decrease by an average of 1.2 points, while the placebo group saw their score decrease by an average of 5.63 points.

Toby Ferguson the principal investigator acknowledged: “What we saw is a decline in ALS function, breathing and strength that was much greater in the placebo groups than in the treated groups. That said, if I were critical, I could poke holes in any one piece of those data, but we also have the data that SOD1 is being reduced.”

ALS is a difficult field in which drugs that show early promise can turn out to offer no benefit, or pose “unjustified risks” to patients in later studies. Biogen knows this as well as anyone, having seen its last ALS effort, dexpramipexole, fail in phase 3. Since then, the company has switched its focus from drugs with specific mechanisms, like anti-inflammatories, to medicines that target genetic mutations. Biogen strategy is  to learn more about the biology of the disease from looking at genetically defined populations (SOD1, C9orf72, ATXN2, XPO1) and then apply those findings to the broader population.

Despite those mixed results and as for other ALS drugs (Nurown, Cu(II)ATSM, Masitinib, AMX0035), there is an online petition for a compassionate access. Nearly 70,000 people have signed this online petition asking Biogen to provide an experimental ALS drug to a patient requesting it under compassionate use, but Biogen disagrees.

At the heart of Biogen’s denial is the question of broader access. The fastest way to get Tofersen to as many patients as possible would be regulatory approval, wrote Biogen chief medical officer, Maha Radhakrishnan, M.D., in a March 17 letter to an ALS patient, Stockman Mauriello that she shared with WCNC. That, of course, requires the completion of clinical trials.

“Providing individual access to Tofersen at this time could jeopardize access to Tofersen for hundreds of SOD1-ALS patients by impeding our ability to complete the study that will determine whether Tofersen is efficacious and safe and to seek subsequent regulatory approvals as quickly as possible,” Radhakrishnan wrote.

It's a moral position, it would not be fair to study participants who were randomized to placebo if Biogen were to offer the drug to patients not participating in the study.

However Biogen will provide early access to Tofersen only after study participants are no longer taking placebo.

“We cannot overlook these patients when considering questions of broader access, and cannot keep them on placebo while at the same time offering Tofersen to those outside of our study,” Sandrock wrote. “Offering Tofersen outside of the study would risk failing to complete the study and risk failing to obtain access for all SOD1-ALS patients".

“These patients agreed to participate in our study acknowledging the risk that they may not receive Tofersen, and with hope that Tofersen could be shown to work and be approved for all patients,” Sandrock wrote.

It has been clear for a while that anti-amyloid antibodies can sweep plaque from the brain, but until now the question of whether this slows cognitive decline has remained hotly contended. Despite some positive signals from four such antibodies, the data have been messy and hard to interpret.

In a Phase 2 trial, donanemab completely cleared plaque in two-thirds of participants. At the 15th International Conference on Alzheimer’s and Parkinson’s Diseases, held virtually March 10–14, Mark Mintun of Eli Lilly & Company presented the Phase 2 trial of the company’s anti-amyloid antibody donanemab.

This is the first anti-amyloid AD drug to meet a clinical endpoint in a Phase 2 trial.  While the drug met its primary endpoint, participants did not get better. Even so, donanemab slowed their decline by an average of 32 percent on a combined cognitive and functional measure. The treatment appeared to nudge down tangles, and worked best at low tangle loads.

The donanemab Phase 2 study offers some of the most compelling evidence to date that amyloid reduction can slow clinical decline, albeit modestly, in early stages of AD. In addition to the encouraging results, there are two unique features of this trial that move the field forward.

First is the decision by design to reduce dose or switch to placebo once patients are in the amyloid-negative range on PET. The discontinued dosing once the participant’s amyloid level normalizes may suggest that, if replicated, there will be not need to treat patients continuously. Doctors may be able to lower their patients amyloid levels, monitor them and, if the levels rise, re-dose. 

The second decision is the selection of patients with intermediate tau aggregates on PET. It is interesting that the overall clinical benefit was driven by the patients in the lowest tau PET tertile. This suggests that the primary role of amyloid-lowering therapies may be in patients in whom tau is not yet widespread, most of whom will be in the preclinical or very earliest clinical stage.

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This book retraces the main achievements of ALS research over the last 30 years, presents the drugs under clinical trial, as well as ongoing research on future treatments likely to be able stop the disease in a few years and to provide a complete cure in a decade or two.

Parkinson's disease is a common neurodegenerative disease. Although the exact etiology and natural course of this disease have yet to be fully clarified, numerous system-level processes and dysfunctions, have been implicated in the pathogenesis of Parkinson's disease.

Lipid droplets are highly dynamic organelles that emerge from the endoplasmic reticulum (ER) membrane. lipid droplets is involved in fatty acid storage and participate in many diseases. For example, myeloid cells, including macrophages, leukocytes, and eosinophils, form lipid droplets in response to inflammation and stress. enter image description here

Normally, intracellular lipid droplets are degraded in lysosomes and deliver fatty acids to mitochondria for their consumption as an alternative energy source during periods of nutrient depletion. However, neurons have a low capacity for mitochondrial fatty acid consumption for energy production. This characteristic makes neurons particularly sensitive to lipid droplet accumulation and peroxidation.

Furthermore, the accumulation of lipid droplets enhances the fatty acid oxidation rate and imposes persistent pressure on the mitochondrial electron transport chain. Lipid overload also leads to ROS production by oxidative enzymes. Emerging evidence indicates that unexpected lipid droplet deposition and peroxidation can accelerate organelle stress and plays a crucial role in the pathogenesis of neurodegenerative diseases.

In a previous study, Xiaojuan Han and colleagues found that kaempferol, a natural flavonoid small molecule, exhibited neuroprotective effects on mice with drug-induced Parkinson's disease.

In the current study, the authors showed in-vitro that kaempferol protected against tyrosine hydroxylase neuronal loss and behavioral deficits in methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) induced Parkinson disease mice, accompanied by reduced lipid oxidative stress in the substantia nigra pars compacta.

Kaempferol-rich food has been linked to a decrease in the risk of developing some types of cancers and cardiovascular disease. Quercetin and kaempferol are among the most ubiquitous polyphenols in fruit and vegetables.

Kaempferol is a chemical produced by Kaempferia galanga, one of four plants called galangal. The extract of Kaempferia galanga causes central nervous system depression, a decrease in motor activity, and a decrease in respiratory rate.

The mice were treated with kaempferol. The rotarod performance time was markedly reduced in MPTP-treated mice, and this effect was prevented by kaempferol. kaempferol also restored the behavioral deficits induced by MPTP, as indicated by the reductions in the turning time and total time in the pole test, without affecting the body weights of the mice.

MPP+, the active metabolite of MPTP, inhibits mitochondrial complex enzymes and causes the cell death that is directly associated with PD. In cultured neuronal cells, kaempferol exhibited a relatively safe concentration range and significantly suppressed lipid droplet accumulation and cellular apoptosis induced by MPP.

Further studies indicated that the protective effect of kaempferol was dependent on autophagy, specifically lipophagy. Critically, kaempferol promoted autophagy to mediate lipid droplet degradation in lysosomes, which then alleviated lipid deposition and peroxidation and the resulting mitochondrial damage, consequently reducing neuronal death.

Furthermore a genetic knockdown abolished the neuroprotective effects of kaempferol against lipid oxidation in Parkinson disease mice.

This work demonstrates that kaempferol prevents dopaminergic neuronal degeneration in Parkinson disease via the inhibition of lipid peroxidation-mediated mitochondrial damage by promoting lipophagy and provides a potential novel therapeutic strategy for Parkinson disease and related NDDs.

A new article by Qaisar, Qayum and Muhammad made me think about links between severe forms of asthma and some ALS forms. Indeed this has already been questioned by scientists. There are only a few studies addressing skeletal muscle function in patients with moderate to severe asthma. enter image description here

Asthma is the result of chronic inflammation of the conducting zone of the airways (most especially the bronchi and bronchioles), which subsequently results in increased contractability of the surrounding smooth muscles. This among other factors leads to bouts of narrowing of the airway and the classic symptoms of wheezing. The narrowing is typically reversible with or without treatment. Occasionally the airways themselves change.

Patients with asthma have diminished activity patterns, leading to deleterious physiologic alterations and ultimately impaired functional capacity. Moreover, they may use corticosteroids during periods of disease exacerbation.

Yet patients with asthma who use systemic corticosteroids present a decrease in respiratory muscle strength. The use of high doses of glucocorticoids causes atrophy and loss of muscle strength, a condition known as steroid myopathy.

An effective pharmacological intervention in asthma remains elusive, partly because molecular mechanisms dictating muscle decline in asthma are not known.

The authors of this new article about the relation between asthma and muscle wasting, investigated the potential contribution of skeletal muscle sarcoplasmic reticulum Ca2+ ATPase (SERCA) to muscle atrophy and weakness in asthmatic patients.

SERCA resides in the sarcoplasmic reticulum within myocytes. The sarcoplasmic reticulum is a membrane-bound structure found within muscle cells that is similar to the endoplasmic reticulum in other cells. The main function of the sarcoplasmic reticulum is to store calcium ions (Ca2+). Calcium ion levels are kept relatively constant, with the concentration of calcium ions within a cell being 10,000 times smaller than the concentration of calcium ions outside the cell.[

SERCA transfers Ca2+ from the cytosol of the cell to the lumen of the sarcoplasmic reticulum. This uses energy from ATP hydrolysis during muscle relaxation.In addition to its calcium-transporting functions, SERCA also generates heat in brown adipose tissue and in skeletal muscles

Quadriceps muscle biopsies were taken from 58 to 72 years old male patients with mild and advanced asthma and the SERCA activity was analyzed in association with cellular redox environment and myonuclear domain size.

Maximal SERCA activity was reduced in skeletal muscles of mild and advanced asthmatics and was associated with reduced expression of SERCA protein and upregulation of sarcolipin, a SERCA inhibitory lipoprotein.

Sarcolipin is an important mediator of muscle based non shivering thermogenesis. It causes the sarcoplasmic reticulum Ca2+-ATPases to stop pumping Ca2+ ions but continue futilely hydrolysing ATP, thus releasing the energy as heat. Sarcolipin mediated heat production is very important for many organisms to maintain a warm body. In mammals thermogenesis by skeletal muscles is complemented by thermogenesis in the brown adipose tissue.

The authors also found downregulation of Ca2+ release protein calstabin and upregulation of Ca2+ buffer, calsequestrin in skeletal muscles of asthmatic patients. The atrophic single muscle fibers had smaller cytoplasmic domains per myonucleus possibly indicating the reduced transcriptional reserves of individual myonuclei. Plasma periostin and C-terminal Agrin Fragment 22 (CAF22) levels were significantly elevated in asthmatic patients and showed a strong correlation with hand-grip strength. These changes were accompanied by substantially elevated markers of global oxidative stress including lipid peroxidation and mitochondrial ROS production.

Agrin, a synaptically located protein, is a key player during initial formation and maintenance of neuromuscularjunctions (NMJ). During development, nerve cells approach muscle fibers and establish synaptic contacts defined as NMJ. Initially, the NMJ is small and weak, but if the contact is successful the connection is maintained and reinforced. Agrin induces and stabilizes clusters of AChRs at the NMJ, promotes synaptic maturation, and maintains the mature state of the NMJ.

C-terminal Agrin Fragment has been proposed as a novel biomarker for sarcopenia originating from the degeneration of the neuromuscular junctions. Manipulation of the agrin signaling path may therefore be a promising way to correct neuromuscular defects.

During development in humans, the growing end of motor neuron axons secrete agrin. When secreted, agrin binds to several receptors on the surface of skeletal muscle. The receptor which appears to be required for the formation of the neuromuscular junction (NMJ) is called the MuSK receptor (Muscle specific kinase). Elevation of MuSK signaling has improved motor performance and delayed denervation in ALS mice (Perez-Garcia and Burden, 2012).

Taken together, the scientists' data suggest that muscle weakness and atrophy in asthma is in part driven by SERCA dysfunction and oxidative stress. The data propose SERCA dysfunction as a therapeutic intervention to address muscle decline in asthma.

You can write me at contact at padiracinnovation.org

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This book retraces the main achievements of ALS research over the last 30 years, presents the drugs under clinical trial, as well as ongoing research on future treatments likely to be able stop the disease in a few years and to provide a complete cure in a decade or two.

Nearly 3 out of 4 cancer patients undergoing chemotherapy suffer from loss of memory, attention or concentration. This range of cognitive deficiencies referred to as chemotherapy-induced cognitive impairment, chemobrain or chemofog severely hampers quality of life of patients undergoing treatment. Advanced neuroimaging analyses have identified structural white and gray matter damage following chemotherapy in patients treated for various types of cancer. Cognitive deficits associated with platinum-based therapeutics such as cisplatin have been observed for 5-10 years post-diagnosis. However, no United States Food and Drug Administration-approved therapeutic interventions are available to date.

Mitochondrial dysfunction, characterized by abnormal morphology, impaired bioenergetics, altered mitochondrial dynamics and mitochondrial DNA mutations, has emerged as an underlying mechanism of several pathologies, including neurodegenerative diseases, cerebral and cardiac ischemia , traumatic brain injury, spinal cord injury, cancer, and chemotherapy-induced cognitive impairment and peripheral neuropathy. Following cerebral ischemia, astrocytes donate their healthy mitochondria to ischemic neurons with dysfunctional mitochondria to maintain adequate mitochondrial function and survival.

Studies in the 1930s already showed that nasally administered bacteria can cross the nasal epithelium within minutes, indicating a paracellular route of entry.

In a recent study, Jenolyn F. Alexander, Cobi J. Heijnen and colleagues demonstrated that nasal administration of mesenchymal stem cells restores cisplatin-induced cognitive impairment in mice and their data indicated that these mesenchymal stem cells act by repairing neuronal mitochondrial damage. enter image description here

It appeared that autologous mesenchymal stem cells work as well as human mesenchymal stem cells in their mouse model. The concept of mitochondrial administration is also being considered the treatment of Parkinson's disease, cerebral and cardiac ischemia, cancer, diabetic nephropathy and spinal cord injuries and some clinical trials for evaluating the safety and efficacy of isolated mitochondria based therapies have also recently commenced.

These findings indicate that cisplatin-induced accumulation of mitochondrial p53 is the cause of the damage to brain mitochondria that leads to cognitive deficits in response to treatment with this chemotherapeutic. The authors recently showed that astrocytes donate their healthy mitochondria and rescue primary cortical neurons damaged by cisplatin in vitro.

Based on their above-mentioned findings that mitochondrial deficits underlie cisplatin-induced neuronal damage and cognitive deficits, and that healthy mitochondria can be taken up by damaged neurons, the scientists hypothesized that isolated mitochondria from healthy mesenchymal stem cells can be used to resolve cisplatin-induced cognitive deficits and the associated structural damage. This would provide an advantage from the perspective of safety because the scientists do not need donation of allogeneic intact cells.

Mice were intraperitoneally injected with cisplatin at 2.3 mg/kg for 5 consecutive days, followed by 5 days of rest and another 5 days of cisplatin injection. The two administrations of mitochondria on mice delivered nasally, completely restored within two weeks mice's executive functioning, spatial recognition and working memory previously impaired by cisplatin treatment. The entry of mesenchymal stem cells into the brain is facilitated by pretreatment of the nasal cavity with hyaluronidase. The scientists maintained the mitochondria in calcium-free mitochondrial respiration buffer until ready for nasal delivery when they were transferred to calcium-free PBS.

Within 30 min of nasal administration, the mitochondria were detectable in the meninges where they were predominantly internalized by macrophages. Within this 30 min, the mitochondria also arrived at the ventricles and choroid plexus, gaining access to the brain.

3 h after delivery, mitochondria were found distributed along the rostral migratory stream where they were internalized by GFAP+ cells. By this time the nasally administered mitochondria also reached the hippocampus. Evidently, these mitochondria that had entered the meninges and brain completely restored the cisplatin-induced white matter damage in the cingulate cortex, synaptic loss in the hippocampus, and the compromised synaptosome membrane integrity and structural mitochondrial defects in synaptosomes as observed 35 days after the second mitochondrial donation.

The scientists used mitochondria isolated from human mesenchymal stem cells in their mouse model for the primary purpose of being able to trace the administered mitochondria with a human-specific mitochondrial antibody.

One topic of concern usually raised with the administration of isolated mitochondria is the possibility that they may function as damage-associated molecular proteins (DAMPs) which could lead to neuroinflammation. However, the scientists did not see activation of inflammatory pathways in the hippocampal transcriptome using human mitochondria. Mitochondria lack many surface antigens including HLA-Class 1 antigens thereby exhibiting lower immunogenicity than mesenchymal stem cells. This is one advantage favoring the clinical translation of allogeneic donation of mitochondria over mesenchymal stem cells.

An important benefit of their approach is the nasal route of delivery. In case of central nervous system (CNS)-targeted delivery of therapeutics, intracranial administration poses serious risk of injury. Intravenous administration has the disadvantage that it may lead to accumulation in the lung and liver requiring high doses which may generate inflammatory reactions or other adverse effects. Systemic administration of therapeutics intended to reach the brain are also obstructed by the blood-brain and blood-cerebrospinal fluid (CSF) barriers. In contrast, the nasal route of delivery is simple, non-invasive and facilitates the delivery of therapeutics to the brain thereby reducing the amount of mitochondria required.

Questions are raised on the ability of isolated mitochondria to survive in high extracellular calcium levels upon administration and to generate sufficient energy to enter cells and continue to function after cellular uptake. Upon internalization, mitochondrial donation enhanced the bioenergetics of the damaged cells for at least 21 days.

It is still unknown how donated mitochondria repair damaged neuronal cells. Interactions between mitochondrial and nuclear genes are vital for fundamental cellular processes such as respiration, transcription and translation. The authors observed that the internalized mitochondria, in many instances were localized close to the nucleus (perinuclear), as if communicating with them. In the literature it has been suggested that donated mitochondria can fuse with mitochondria of damaged recipient cells and thereby repair the bioenergetic machinery or replenish mitochondrial DNA in the acceptor cell.

Although this might be true, it remains difficult to accept that the few mesenchymal stem cells-derived mitochondria can restore cellular respiration by physical fusion to the many acceptor cell mitochondria. It is more likely that the donated mitochondria activate a transcriptional program leading to enhanced Nrf2 signaling and subsequent recovery of host mitochondrial function by a host of antioxidants.

Their findings elucidate the therapeutic effects of nasally delivered mitochondria to resolve unmet needs in the treatment of cancer survivors with neurotoxicities and highlights its potential significance for clinical translation. It also provides promise for treatment of a range of cognitive and neuronal deficits warranting further investigation in large animal models.

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This book retraces the main achievements of ALS research over the last 30 years, presents the drugs under clinical trial, as well as ongoing research on future treatments likely to be able stop the disease in a few years and to provide a complete cure in a decade or two.

Every month a revolutionary discovery?

Every month the specialized press informs us of decisive progress in the treatment of ALS. At the beginning of February, it was a young doctor in Scotland, who turns out to have only done in-vitro experiments showing lengthening of axons of lower motor neurons when subjected to a PGC1α inhibitor, but the press service of his university had translated this as being a great discovery allowing to hope for an ALS drug. It has been known since 2008 that PPAR-γ is a transcription factor that interacts with PGC-1α and that they are involved in ALS.

We are at the end of the month, and here is an important new discovery announcement regarding a treatment for ALS. It is a molecule that has been developed for almost ten years at Northwestern University in Illinois. Several articles have already been written about this molecule. The aim was to find a molecule which is both characterized by low toxicity, capable of crossing the blood-brain barrier and of having an action on the progression of disease. But in 10 years, extensive testing of this molecule had not been carried out on ALS model mice. It would seem that this is the case today, perhaps thanks to the collaboration between two teams, those of Professor Richard B. Silverman who is oriented "chemistry" and that of Professor Hande Ozdinler rather oriented "biology".

There is both good and bad news in this new article. The bad news is that the molecule would only be effective on upper motor neurons. This is a bit surprising and there really isn't any elaborate explanation that would be provided by the authors of the article. Usually in ALS both types of neurons are affected and restoring the functioning of the upper motor neurons will be of little help if the lower motor neurons are unable to control the muscles. In addition, the article is all about restoring the health of diseased neurons, which therefore must treated as soon as symptoms appear.

The authors use very aggressive language

The authors believe that other researchers did not seek to develop therapies for upper motor neurons. This is obviously not true, the number of studies using brain samples from deceased patients are there to testify.

The authors are also not shy about saying that other researchers are enough dumb to do their in-vitro research with different sets of cell lines, sometimes unrelated to motor neuron biology. Since the nervous system involves a lot of different types of cells, and these come from only a few lines of stem cells, on the contrary it seems a very good practice.

In addition, we could counter this focus on neurons by recalling that neurons do not perform their function in isolation, cells collaborate on the same task. Moreover, reading the article one immediately wonders why the authors did not examine the astrocytes, which are only present in the central nervous system.

They further explain that there has never been a study that examines upper motor neurons at the cellular level during the disease. The number of studies on ALS using mice models of the disease is proof of the fallacy of this claim.

A therapy that is effective regardless of the type of proteopathy.

The good news, apparently unexpected, is that the molecule is effective for both SOD1 (about 2% of patients) and TDP-43 (about 95% of patients) pathologies.

In this study, only four thin slices of motor cortex from normal control subjects without neurological disease and nine slices from ALS patients were used in addition to mice studies. Again the number is very low, in other studies several hundred tissues from deceased people are studied. There are also databases that allow data to be shared between researchers.

Histological sections of deceased patients

Upper motor neurons were only counted if their soma and apical dendrite were both visualized in the same 50 µm thick section. This assumes a severe selection of neurons, are the selected neurons representative of the upper motor neuron population?

Identification of NU-9:

The chiral 1,3-Diones cyclohexane, is a cyclohexane molecule containing two ketone groups. As said above, in fact work on NU-9 started almost ten years ago. High throughput screening of over 50,000 molecules was performed using a PC12 cell-based assay expressing SOD1G93A to identify compounds that attenuate protein aggregation and cytotoxicity. This made it possible to identify three families of compounds:

  • A first compound was selected from over 50 analogues of cyclohexan-1,3-dione, because of its ability to reduce mSOD1-mediated toxicity and inhibit protein aggregation.

  • Several rounds of optimization were performed, resulting in another compound, which also had excellent pharmaceutical properties in vitro, but did not enter neurons. Further modifications of this compound then led to the generation of NU-9, which crosses the blood-brain barrier, penetrates cortical neurons and has favorable pharmacokinetic properties.

Mouse management

The mice were derived from a cross between SOD1-type ALS model mice and mice carrying a fluorescent protein. In this study, only female mice were used for the experiments. The study involves a very small number of mice, one might wonder if it would be of interest to do a study on such a small number of mice, because no smoothing can erase the inevitable indesirable events. Mice noticeably overreact to tiny variations in their environment, we recently reported that ALS model mice were getting sick at Stanford but not at MIT!

  • Ten WT-UeGFP and six hSOD1G93A-UeGFP mice were treated with placebo,
  • Five WT-UeGFP mice and seven hSOD1G93A-UeGFP mice were treated with 20 mg / kg / day dose of NU-9.
  • Eleven WT-UeGFP mice, nine hSOD1G93A-UeGFP mice and four prpTDP-43A315T-UeGFP mice were treated with a dose of 100 mg / kg / day of NU-9.

The dose of NU-9 or placebo was administered once daily by oral gavage, starting on postnatal day P60 and continuing until P120. This NU-9 compound is able to prolong the lifespan of an ALS model mouse by 13% with a dose of 20 mg / kg. A repeated 7-day toxicological study in mice demonstrated a no-observed-adverse-effect level of 100 mg / kg.

All of the mice were sacrificed after 120 days (P120), which is considered a terminal stage for this type of ALS model mouse and approximately 60% of the upper motor neurons in the motor cortex are then lost while the motor neurons are lost. remaining upper ones have a smaller soma size and vacuolated and disintegrated apical dendrites. There does not seem to have been any test on an increase in the lifespan of the treated mice.

SOD1 qualitative analyzes

The electron microscope allowed cell type analyzes of upper motor neurons and their key organelles with great precision. At P120, the upper motor neurons of the placebo-treated hSODG93A-UeGFP mice had lost most of their cytoplasmic integrity. There were very few intact organelles left in the soma. However, the presence of disintegrated mitochondria and endoplasmic reticulum was evident. The mitochondria had mostly lost the integrity of their inner membrane, aggregated, enlarged or started to disintegrate. The endoplasmic reticulum also showed broken and scattered cisterns.

NU-9 treatment (dose of 100 mg / kg per day) showed profound improvements in both the structure and integrity of the mitochondria and endoplasmic reticulum of diseased upper motor neurons. Upon treatment, the soma of these neurons showed an intact nuclear membrane, which was devoid of any invagination or protrusion, and the detection of many organelles which were appropriate in size, location and interactions between them. The mitochondrial inner membrane was intact with proper ridges that were in close contact with the endoplasmic reticulum.

SOD1 quantitative analyzes

The authors then performed quantitative analyzes to determine whether these improvements were widely seen in diseased upper motor neurons treated with NU-9. The total number of mitochondria in upper motor neurons of hSODG93A-UeGFP mice was significantly increased after 100 mg / kg / day NU-9 treatment compared to upper motor neurons treated with placebo. The total number of mitochondria after NU-9 treatment was comparable to that of healthy mice. In addition, NU-9 treatment significantly increased the number of healthy mitochondria and endoplasmic reticulum.

present in the motor cortex of hSOD1G93A-UeGFP mice treated for 60 days with 100 mg / kg / day of NU-9 became almost comparable to that of the higher motor neuron numbers present in healthy mice

What about TDP-43?

Since NU-9 appears to improve the integrity of mitochondria and endoplasmic reticulum of upper motor neurons diseased due to mSOD1 toxicity, and these are problems that are also found in pathologies such as TDP-43, the authors speculated that NU-9 might also be effective in TDP-43 pathology. It still seems like a big conceptual step, because they are two distinct disease models. Even if NU-9 has an effect on the structure of the mitochondria and endoplasmic reticulum of higher motor neurons, it should not act on poorly formed and poorly localized protein aggregates that are already present in cytosol? But as the article assumes the drug is administered as soon as symptoms appears, they do not have to deal with that problem.

To test their new hypothesis, the scientists generated a new type of mouse, this time modeling TDP-43 type ALS.

Four mice were treated with a dose of 100 mg / kg / day of NU-9, and 3 mice of the prpTDP-43A315T-UeGFP type were used as a control. The WT-UeGFP mouse cohort was used as a healthy control for both groups.

TDP-43 qualitative analyzes

The NU-9 treatment resulted in profound improvements in both mitochondria and endoplasmic reticulums of higher motor neurons. The mitochondria, especially their internal membranes, became intact and there was no sign of mitoautophagy or mitophagy. The endoplasmic reticulum retained its structure with attached ribosomes, and there was no enlargement or disintegration of the cisterns.

TDP-43 quantitative analyzes

Quantitative analysis confirmed a significant increase in the number of total mitochondria per upper motor neuron per section after 100 mg / kg / day of NU-9 treatment. This number of mitochondria after NU-9 treatment in prpTDP-43A315T-UeGFP mice became comparable to that of healthy mice. The average percentage of healthy mitochondria also increased significantly with NU-9 treatment compared to diseased upper motor neurons. NU-9 treatment also increased the average number of intact endoplasmic reticulum cisterns in upper motor neurons.

The scientists then examined whether NU-9 treatment would also promote cell integrity and the survival of the higher motor neurons with TDP-43 pathology in vivo. The health and integrity of the apical dendrites in prpTDP-43A315T-UeGFP mice showed a profound improvement with the NU-9 treatment because the percentage of upper motor neurons with vacuolated primary apical dendrites was significantly reduced. More interestingly, the mean number of higher motor neurons in the motor cortex of prpTDP-43A315T-UeGFP mice treated with NU-9 was dramatically increased compared to that of untreated prpTDP-43A315T-UeGFP mice.

The same WT-UeGFP cohort was used as a healthy control for the hSOD1G93A-UeGFP and prpTDP-43A315T-UeGFP mice, as mentioned previously. The higher motor neuron numbers with the NU-9 treatment were comparable and almost identical to those of the healthy control mice treated with the placebo, revealing the ability of NU-9 to eliminate the continued degeneration of the higher motor neurons.

Effect of NU-9 on lower motor neurons

In order to determine whether NU-9 treatment also improves the health and survival of lower motor neurons (lower motor neurons), the authors studied the lumbar cords of hSOD1G93A-UeGFP and prpTDP-43A315T-UeGFP mice. As indicated by previous studies, there was no significant loss of lower motor neurons in the spinal cord of prpTDP-43A315T-UeGFP mice, even at P120, and therefore an investigation of NU-9 treatment on motor neuron survival inferior was not possible. This seems to indicate that TDP-43 pathology only affects the higher motor neurons, yet other studies show the opposite.

However, in the case of SOD1, there was a dramatic reduction in the number of lower motor neurons in hSOD1G93A-UeGFP mice compared to healthy mice.

Macroscopic effects

The authors quantitatively assessed the changes in the number of lower motor neurons in the lumbar spinal cord of mice that were treated with either placebo or NU-9 (20 or 100 mg / kg / day), or healthy control mice. . NU-9 treatment, regardless of dose, was not sufficient to eliminate the ongoing lower motor neuron degeneration in hSOD1G93A-UeGFP mice.

NU-9 treatment improves upper motor neuron function Even though most behavioral tests fail to properly assess upper motor neuron health and connectivity, the hanging wire test would be more specific to upper motor neuron integration.

The untreated hSOD1G93A-UeGFP mice could not stay on the hanger as the disease progressed. In contrast, hSOD1G93A-UeGFP mice treated with 100 mg / kg / day of NU-9 performed better than hSOD1G93A-UeGFP mice treated with placebo, and this performance was comparable to that of healthy mice at same age. However, treatment with NU-9 did not result in a significant improvement in performance on the rotarod test at any dose.

The prpTDP-43A315T mice performed worse than the WT litter mates on rotarod and hanging wire tests. However, when treated with 100 mg / kg / day of NU-9, they performed better on the hanging wire test, comparable to healthy WT mice at P120. Unlike the hSOD1G93A mouse model, even the Rotarod test revealed a significant improvement in the TDP-43 model only after 30 days of NU-9 treatment.

Conclusion

The possibility that NU-9 can improve the integrity of both mitochondria and endoplasmic reticulum is important, because, although the underlying causes of the disease are heterogeneous, many clues converge on the proper functioning of the mitochondria and the endoplasmic reticulum. Disruption of intracellular membrane organelles, such as the Golgi apparatus, has been suggested as a possible cause of ALS and is proposed to be upstream of endoplasmic reticulum dysfunction.

This could explain why the NU-9 treatment improves the cytoarchitecture of higher motoneurons and eliminates their progressive degeneration in hSOD1G93A and TDP-43A315T mice.

However, this does not explain why lower motor neurons would not be affected by this molecule. The explanation given that these are different lineages seems very short and has not been further investigated. At no time axons are mentioned in this article, which seems odd in an article that claims to seek a cure for ALS. It seems to me that this weakens the claim that NU-9 treatment improves upper motor neuron cytoarchitecture as this architecture is not extensively tested.

Moreover, the number of mice tested is very, very low and probably statistically meaningless. It is the same for the few histological sections of deceased patients, and the selection of motor neurons. We can also notice that it has been demonstrated for more than 15 years that other types of cells are involved in ALS, starting with astrocytes, than motor neurons. This has absolutely not been studied in this article. However, when a molecule is effective on the higher motor neurons and not on the lower motor neurons, it immediately suggests that it is not on the neurons that it acts, but on the astrocytes!.

All this considerably relativizes the very strong assertions of the press service of the university which reported that "After 60 days of treatment, diseased brain cells look like healthy cells".

For any correspondence write to me at contact [at] padiracinnovation.org

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This book retraces the main achievements of ALS research over the last 30 years, presents the drugs under clinical trial, as well as ongoing research on future treatments likely to be able stop the disease in a few years and to provide a complete cure in a decade or two.

Parkinson’s disease (Parkinson’s disease) is a major neurodegenerative disorder. It currently lacks a clinically relevant treatment that can directly target the disease-causing processes. Current clinical approaches, like deep brain stimulation and pharmacological treatments with levodopa and dopamine agonists, only relieve symptoms. The efficacy of these treatments is largely limited by their undesirable complications and side effects. enter image description here Source: By Ajpolino via Wikipedia

Since α-synuclein is overexpressed under certain pathological conditions of PD and these upregulated proteins can interfere with many physiological processes, such as ER-to-Golgi transport, synaptic transmission, and mitochondria function and morphology, robustly knocking down the overexpressed α-synucleinmay have better neuroprotective efficacy in restoring normal cellular functions in the Parkinson’s disease brain than simply inhibiting the formation of toxic α-synuclein oligomers.

Knockdown of α-synuclein using genetic manipulations, such as antisense oligonucleotide and small interfering RNA (siRNA), has shown protection of dopaminergic neurons in various models of Parkinson’s disease.

The clinical translation of these manipulations into an efficient Parkinson’s disease therapy has however costly and uncomfortable, as it is mainly accomplished by an invasive injection or viral infection. These technologies may not be clinically practical for therapeutic use in human patients.

Here the scientists report the development of a short, BBB and plasma membrane-permeant synthetic peptide that can rapidly reduce endogenous α-synuclein via proteasomal degradation.

Using both in vitro and in vivo models of Parkinson’s disease, the scientists provide proof-of-principle evidence for using this small α-synuclein knockdown peptide as a potential Parkinson’s disease therapy.

The authors first demonstrated that the Tat-βsyn-degron peptide can specifically reduce the level of α-synuclein both in vitro and in vivo. The authors then showed that the peptide-induced α-synuclein knockdown is associated with protection of dopaminergic neurons against toxin-induced damage in a culture model of Parkinson’s disease.

Most importantly, the scientists were able to demonstrate the therapeutic potential of systemic application of the Tat-βsyn-degron peptide as an effective Parkinson’s disease treatment in two well-characterized animal models of Parkinson’s disease.

Their α-synuclein knockdown peptide (Tat-βsyn-degron) is innovative as the peptide directly targets one of the disease-causing processes, and can be expected to stop or slow down the progression of the disease.

In addition, the peptide-mediated knockdown has a clear temporal advantage over antisense or siRNA-mediated knockdown. α-synuclein is a very stable protein with a long half-life while by hijacking the endogenous proteasomal degradation system in the cell, the Tat-βsyn-degron peptide produced a rapid and robust degradation of α-synuclein protein within a few hours.

It is also interesting to note that α-synuclein is also expressed in tissues outside the central nervous system and the scientists found that a single intraperitoneal injection of the Tat-βsyn-degron peptide similarly reduced the α-synuclein expression in the kidney and the spleen of wild-type C57BL/6 mice .

A recent success in a phase 3 clinical trial has already demonstrated that a Tat-fused short peptide is not only safe, but therapeutically effective in protecting neurons against ischemic damage in humans. The authors hope this α-synuclein knockdown peptide may also have the potential to be quickly translated into the clinic as an effective disease-modifying treatment that directly targets the disease-causing process of Parkinson’s disease.

Due to the versatility of their peptide-mediated protein knockdown method, the scientists can theoretically target disease-causing cellular proteins by simply changing the protein-binding sequence of the targeting peptide. Since many human diseases, including some of the age-related neurodegenerative diseases such as ALS, Alzheimer’s disease and Huntington’s disease, are pathologically caused by gain of function of a protein due to its mutations and/or increased expression levels, the proposed study can be expected to spur the development of new therapeutics for human diseases beyond Parkinson’s disease.

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This book retraces the main achievements of ALS research over the last 30 years, presents the drugs under clinical trial, as well as ongoing research on future treatments likely to be able stop the disease in a few years and to provide a complete cure in a decade or two.

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