Peroxisome proliferator activator receptor gamma coactivator-1alpha (PGC-1α) improves motor performance and survival in a mouse model of amyotrophic lateral sclerosis

Potential of resveratrol in the treatment of systemic lupus erythematosus (Review)

Systemic lupus erythematosus (SLE) is a multi‑system chronic autoimmune disease with a complex occurrence and development process, associated with immune disorders, uncertain prognosis, and treatment modalities which vary by patient and disease activity. At present, the clinical treatment of SLE mainly focuses on hormones and immunosuppressants. In recent years, the research on new treatment strategies for SLE has been booming, and strong preclinical results and clinical research have promoted the development of numerous drugs (such as rituximab and orencia), but numerous of these drugs have failed to achieve effectiveness in clinical trials, and there are some adverse reactions. Recent evidence suggests that resveratrol (RSV) has the effect of ameliorating immune disorders by inhibiting overactivation of immune cells. In the present review, advances in research on the protective effects and potential mechanisms of RSV against SLE are summarized and the potential potency of RSV and its use as a promising therapeutic option for the treatment of SLE are highlighted.

Role of Mitochondrial Dysfunctions in Neurodegenerative Disorders: Advances in Mitochondrial Biology

Mitochondria, essential organelles responsible for cellular energy production, emerge as a key factor in the pathogenesis of neurodegenerative disorders. This review explores advancements in mitochondrial biology studies that highlight the pivotal connection between mitochondrial dysfunctions and neurological conditions such as Alzheimer's, Parkinson's, Huntington's, ischemic stroke, and vascular dementia. Mitochondrial DNA mutations, impaired dynamics, and disruptions in the ETC contribute to compromised energy production and heightened oxidative stress. These factors, in turn, lead to neuronal damage and cell death. Recent research has unveiled potential therapeutic strategies targeting mitochondrial dysfunction, including mitochondria targeted therapies and antioxidants. Furthermore, the identification of reliable biomarkers for assessing mitochondrial dysfunction opens new avenues for early diagnosis and monitoring of disease progression. By delving into these advancements, this review underscores the significance of understanding mitochondrial biology in unraveling the mechanisms underlying neurodegenerative disorders. It lays the groundwork for developing targeted treatments to combat these devastating neurological conditions.

ALS-Linked VapB P56S Mutation Alters Neuronal Mitochondrial Turnover at the Synapse

Mitochondrial population maintenance in neurons is essential for neuron function and survival. Contact sites between mitochondria and the endoplasmic reticulum (ER) are poised to regulate mitochondrial homeostasis in neurons. These contact sites can facilitate transfer of calcium and lipids between the organelles and have been shown to regulate aspects of mitochondrial dynamics. Vesicle-associated membrane protein-associated protein B (VapB) is an ER membrane protein present at a subset of ER-mitochondrial contact sites. A proline-to-serine mutation in VapB at amino acid 56 (P56S) correlates with susceptibility to amyotrophic lateral sclerosis (ALS) type 8. Given the relationship between failed mitochondrial health and neurodegenerative disease, we investigated the function of VapB in mitochondrial population maintenance. We demonstrated that transgenic expression of VapBP56S in zebrafish larvae (sex undetermined) increased mitochondrial biogenesis, causing increased mitochondrial population size in the axon terminal. Expression of wild-type VapB did not alter biogenesis but, instead, increased mitophagy in the axon terminal. Using genetic manipulations to independently increase mitochondrial biogenesis, we show that biogenesis is normally balanced by mitophagy to maintain a constant mitochondrial population size. VapBP56S transgenics fail to increase mitophagy to compensate for the increase in mitochondrial biogenesis, suggesting an impaired mitophagic response. Finally, using a synthetic ER-mitochondrial tether, we show that VapB's function in mitochondrial turnover is likely independent of ER-mitochondrial tethering by contact sites. Our findings demonstrate that VapB can control mitochondrial turnover in the axon terminal, and this function is altered by the P56S ALS-linked mutation.

Evidence of mitochondrial dysfunction in ALS and methods for measuring in model systems

Metabolic dysfunction is a hallmark of multiple amyotrophic lateral sclerosis (ALS) models with a majority of ALS patients exhibiting hypermetabolism. The central sites of metabolism in the cell are mitochondria, capable of utilising a multitude of cellular substrates in an array of ATP-generating reactions. With reactive oxygen species (ROS) production occurring during some of these reactions, mitochondria can contribute considerably to oxidative stress. Mitochondria are also very dynamic organelles, interacting with other organelles, undergoing fusion/fission in response to changing metabolic states and being turned over by the cell regularly. Disruptions to many of these mitochondrial functions and processes have been reported in ALS models, largely indicating compromised mitochondrial function, increased ROS production by mitochondria, disrupted interactions with the endoplasmic reticulum and reduced turnover. This chapter summarises methods routinely used to assess mitochondria in ALS models and the alterations that have been reported in these models.

Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) family in physiological and pathophysiological process and diseases

Peroxisome proliferator-activated receptor gamma coactivator-1 (PGC-1) family (PGC-1s), consisting of three members encompassing PGC-1α, PGC-1β, and PGC-1-related coactivator (PRC), was discovered more than a quarter-century ago. PGC-1s are essential coordinators of many vital cellular events, including mitochondrial functions, oxidative stress, endoplasmic reticulum homeostasis, and inflammation. Accumulating evidence has shown that PGC-1s are implicated in many diseases, such as cancers, cardiac diseases and cardiovascular diseases, neurological disorders, kidney diseases, motor system diseases, and metabolic disorders. Examining the upstream modulators and co-activated partners of PGC-1s and identifying critical biological events modulated by downstream effectors of PGC-1s contribute to the presentation of the elaborate network of PGC-1s. Furthermore, discussing the correlation between PGC-1s and diseases as well as summarizing the therapy targeting PGC-1s helps make individualized and precise intervention methods. In this review, we summarize basic knowledge regarding the PGC-1s family as well as the molecular regulatory network, discuss the physio-pathological roles of PGC-1s in human diseases, review the application of PGC-1s, including the diagnostic and prognostic value of PGC-1s and several therapies in pre-clinical studies, and suggest several directions for future investigations. This review presents the immense potential of targeting PGC-1s in the treatment of diseases and hopefully facilitates the promotion of PGC-1s as new therapeutic targets.

Mitochondria in health, disease, and aging

Mitochondria are well known as organelles responsible for the maintenance of cellular bioenergetics through the production of ATP. Although oxidative phosphorylation may be their most important function, mitochondria are also integral for the synthesis of metabolic precursors, calcium regulation, the production of reactive oxygen species, immune signaling, and apoptosis. Considering the breadth of their responsibilities, mitochondria are fundamental for cellular metabolism and homeostasis. Appreciating this significance, translational medicine has begun to investigate how mitochondrial dysfunction can represent a harbinger of disease. In this review, we provide a detailed overview of mitochondrial metabolism, cellular bioenergetics, mitochondrial dynamics, autophagy, mitochondrial damage-associated molecular patterns, mitochondria-mediated cell death pathways, and how mitochondrial dysfunction at any of these levels is associated with disease pathogenesis. Mitochondria-dependent pathways may thereby represent an attractive therapeutic target for ameliorating human disease.

Mitochondrial regulation of local supply of energy in neurons

Brain computation is metabolically expensive and requires the supply of significant amounts of energy. Mitochondria are highly specialized organelles whose main function is to generate cellular energy. Due to their complex morphologies, neurons are especially dependent on a set of tools necessary to regulate mitochondrial function locally in order to match energy provision with local demands. By regulating mitochondrial transport, neurons control the local availability of mitochondrial mass in response to changes in synaptic activity. Neurons also modulate mitochondrial dynamics locally to adjust metabolic efficiency with energetic demand. Additionally, neurons remove inefficient mitochondria through mitophagy. Neurons coordinate these processes through signalling pathways that couple energetic expenditure with energy availability. When these mechanisms fail, neurons can no longer support brain function giving rise to neuropathological states like metabolic syndromes or neurodegeneration.

Resveratrol in Neurodegeneration, in Neurodegenerative Diseases, and in the Redox Biology of the Mitochondria

Neurodegeneration is a process leading to the progressive loss of structure and functions of neurons. Many neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease have shown many common points at the subcellular level. Neurons are metabolically active cells and need a high amount of energy. Mitochondria are known as the energy synthesis center for cells, involved in the synthesis of adenosine triphosphate by oxidative phosphorylation. Rather than just being an energy synthesis center, it has critical importance for many cellular functions such as calcium homeostasis, cell proliferation, cell growth, and apoptosis. In the process of mitochondrial dysfunction, cellular functions are disrupted and cells enter the apoptotic or necrotic pathway. Resveratrol (trans-3,5,4-trihydoxystilbene), a plant-derived polyphenol found in the seed of grapes, berries, peanuts, and wine, has many biological effects such as inhibition of lipid peroxidation, scavenging of free radicals, changes in eicosanoid synthesis, inhibition of platelet aggregation, anti-inflammatory and anticancer activity, and regulation of lipid metabolism. Through the reviewed literature, the current study investigated the protective role of resveratrol in neurodegenerative diseases. Studies show that resveratrol moderates mitochondrial function, redox status, and cellular dynamics in both in vivo and in vitro experimental models of neurodegeneration. Resveratrol suppresses reactive oxygen species production by reducing the activity of complex III due to its competition effect with coenzyme Q. In the present work, we discussed the protective effects of resveratrol on neurodegeneration, neurodegenerative diseases, and the redox biology of the mitochondria.

The Role of PGC-1α-Mediated Mitochondrial Biogenesis in Neurons

Neurons are highly dependent on mitochondrial ATP production and Ca²⁺ buffering. Neurons have unique compartmentalized anatomy and energy requirements, and each compartment requires continuously renewed mitochondria to maintain neuronal survival and activity. Peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) is a key factor in the regulation of mitochondrial biogenesis. It is widely accepted that mitochondria are synthesized in the cell body and transported via axons to the distal end. However, axonal mitochondrial biogenesis is necessary to maintain axonal bioenergy supply and mitochondrial density due to limitations in mitochondrial axonal transport rate and mitochondrial protein lifespan. In addition, impaired mitochondrial biogenesis leading to inadequate energy supply and neuronal damage has been observed in neurological disorders. In this review, we focus on the sites where mitochondrial biogenesis occurs in neurons and the mechanisms by which it maintains axonal mitochondrial density. Finally, we summarize several neurological disorders in which mitochondrial biogenesis is affected.

Antioxidant Potential of Resveratrol as the Result of Radiation Exposition

The purpose of this study was to determine the effect of electron beam irradiation (EBI) at a dose of 25 kGy on the stability and antioxidant properties of resveratrol (RSV), a nutraceutical with clinically proven activity. The electron paramagnetic resonance (EPR) method was used to evaluate the concentration of free radicals after irradiation. Minor changes in chemical structure due to free radicals induced by EBI were confirmed by FTIR spectroscopy. HPLC and HPLC-MS analysis ruled out the appearance of degradation products after irradiation. In addition, HPLC analysis confirmed the absence of trans- to cis-resveratrol conversion. Changes in the antioxidant potential of RSV after irradiation were studied using DPPH, ABTS, CUPRAC, and FRAP techniques. It was confirmed that EBI favorably affected the antioxidant properties of tests based on the HAT mechanism (increase in DPPH and CUPRAC tests).

The neuroprotective effects of fisetin, a natural flavonoid in neurodegenerative diseases: Focus on the role of oxidative stress

Oxidative stress (OS) disrupts the chemical integrity of macromolecules and increases the risk of neurodegenerative diseases. Fisetin is a flavonoid that exhibits potent antioxidant properties and protects the cells against OS. We have viewed the NCBI database, PubMed, Science Direct (Elsevier), Springer-Nature, ResearchGate, and Google Scholar databases to search and collect relevant articles during the preparation of this review. The search keywords are OS, neurodegenerative diseases, fisetin, etc. High level of ROS in the brain tissue decreases ATP levels, and mitochondrial membrane potential and induces lipid peroxidation, chronic inflammation, DNA damage, and apoptosis. The subsequent results are various neuronal diseases. Fisetin is a polyphenolic compound, commonly present in dietary ingredients. The antioxidant properties of this flavonoid diminish oxidative stress, ROS production, neurotoxicity, neuro-inflammation, and neurological disorders. Moreover, it maintains the redox profiles, and mitochondrial functions and inhibits NO production. At the molecular level, fisetin regulates the activity of PI3K/Akt, Nrf2, NF-κB, protein kinase C, and MAPK pathways to prevent OS, inflammatory response, and cytotoxicity. The antioxidant properties of fisetin protect the neural cells from inflammation and apoptotic degeneration. Thus, it can be used in the prevention of neurodegenerative disorders.

Mitochondrial protein dysfunction in pathogenesis of neurological diseases

Mitochondria are essential organelles for neuronal function and cell survival. Besides the well-known bioenergetics, additional mitochondrial roles in calcium signaling, lipid biogenesis, regulation of reactive oxygen species, and apoptosis are pivotal in diverse cellular processes. The mitochondrial proteome encompasses about 1,500 proteins encoded by both the nuclear DNA and the maternally inherited mitochondrial DNA. Mutations in the nuclear or mitochondrial genome, or combinations of both, can result in mitochondrial protein deficiencies and mitochondrial malfunction. Therefore, mitochondrial quality control by proteins involved in various surveillance mechanisms is critical for neuronal integrity and viability. Abnormal proteins involved in mitochondrial bioenergetics, dynamics, mitophagy, import machinery, ion channels, and mitochondrial DNA maintenance have been linked to the pathogenesis of a number of neurological diseases. The goal of this review is to give an overview of these pathways and to summarize the interconnections between mitochondrial protein dysfunction and neurological diseases.

Altered Bioenergetics and Metabolic Homeostasis in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease that primarily affects motor neurons and causes muscle atrophy, paralysis, and death. While a great deal of progress has been made in deciphering the underlying pathogenic mechanisms, no effective treatments for the disease are currently available. This is mainly due to the high degree of complexity and heterogeneity that characterizes the disease. Over the last few decades of research, alterations to bioenergetic and metabolic homeostasis have emerged as a common denominator across many different forms of ALS. These alterations are found at the cellular level (e.g., mitochondrial dysfunction and impaired expression of monocarboxylate transporters) and at the systemic level (e.g., low BMI and hypermetabolism) and tend to be associated with survival or disease outcomes in patients. Furthermore, an increasing amount of preclinical evidence and some promising clinical evidence suggests that targeting energy metabolism could be an effective therapeutic strategy. This review examines the evidence both for and against these ALS-associated metabolic alterations and highlights potential avenues for therapeutic intervention.

Butyrate Ameliorates Mitochondrial Respiratory Capacity of The Motor-Neuron-like Cell Line NSC34-G93A, a Cellular Model for ALS

Mitochondrial defects in motor neurons are pathological hallmarks of ALS, a neuromuscular disease with no effective treatment. Studies have shown that butyrate, a natural gut-bacteria product, alleviates the disease progression of ALS mice overexpressing a human ALS-associated mutation, hSOD1^G93A. In the current study, we examined the potential molecular mechanisms underlying the effect of butyrate on mitochondrial function in cultured motor-neuron-like NSC34 with overexpression of hSOD1^G93A (NSC34-G93A). The live cell confocal imaging study demonstrated that 1mM butyrate in the culture medium improved the mitochondrial network with reduced fragmentation in NSC34-G93A cells. Seahorse analysis revealed that NSC34-G93A cells treated with butyrate showed an increase of ~5-fold in mitochondrial Spare Respiratory Capacity with elevated Maximal Respiration. The time-dependent changes in the mRNA level of PGC1α, a master regulator of mitochondrial biogenesis, revealed a burst induction with an early increase (~5-fold) at 4 h, a peak at 24 h (~19-fold), and maintenance at 48 h (8-fold) post-treatment. In line with the transcriptional induction of PGC1α, both the mRNA and protein levels of the key molecules (MTCO1, MTCO2, and COX4) related to the mitochondrial electron transport chain were increased following the butyrate treatment. Our data indicate that activation of the PGC1α signaling axis could be one of the molecular mechanisms underlying the beneficial effects of butyrate treatment in improving mitochondrial bioenergetics in NSC34-G93A cells.

Deciphering the role of PGC-1α in neurological disorders: from mitochondrial dysfunction to synaptic failure

The onset and mechanisms underlying neurodegenerative diseases remain uncertain. The main features of neurodegenerative diseases have been related with cellular and molecular events like neuronal loss, mitochondrial dysfunction and aberrant accumulation of misfolded proteins or peptides in specific areas of the brain. The most prevalent neurodegenerative diseases belonging to age-related pathologies are Alzheimer's disease, Huntington's disease, Parkinson's disease and amyotrophic lateral sclerosis. Interestingly, mitochondrial dysfunction has been observed to occur during the early onset of several neuropathological events associated to neurodegenerative diseases. The master regulator of mitochondrial quality control and energetic metabolism is the transcriptional coactivator peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Additionally, it has been observed that PGC-1α appears to be a key factor in maintaining neuronal survival and synaptic transmission. In fact, PGC-1α downregulation in different brain areas (hippocampus, substantia nigra, cortex, striatum and spinal cord) that occurs in function of neurological damage including oxidative stress, neuronal loss, and motor disorders has been seen in several animal and cellular models of neurodegenerative diseases. Current evidence indicates that PGC-1α upregulation may serve as a potent therapeutic approach against development and progression of neuronal damage. Remarkably, increasing evidence shows that PGC-1α deficient mice have neurodegenerative diseases-like features, as well as neurological abnormalities. Finally, we discuss recent studies showing novel specific PGC-1α isoforms in the central nervous system that appear to exert a key role in the age of onset of neurodegenerative diseases and have a neuroprotective function in the central nervous system, thus opening a new molecular strategy for treatment of neurodegenerative diseases. The purpose of this review is to provide an up-to-date overview of the PGC-1α role in the physiopathology of neurodegenerative diseases, as well as establish the importance of PGC-1α function in synaptic transmission and neuronal survival.

Covering the Role of PGC-1α in the Nervous System

The peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a well-known transcriptional coactivator involved in mitochondrial biogenesis. PGC-1α is implicated in the pathophysiology of many neurodegenerative disorders; therefore, a deep understanding of its functioning in the nervous system may lead to the development of new therapeutic strategies. The central nervous system (CNS)-specific isoforms of PGC-1α have been recently identified, and many functions of PGC-1α are assigned to the particular cell types of the central nervous system. In the mice CNS, deficiency of PGC-1α disturbed viability and functioning of interneurons and dopaminergic neurons, followed by alterations in inhibitory signaling and behavioral dysfunction. Furthermore, in the ALS rodent model, PGC-1α protects upper motoneurons from neurodegeneration. PGC-1α is engaged in the generation of neuromuscular junctions by lower motoneurons, protection of photoreceptors, and reduction in oxidative stress in sensory neurons. Furthermore, in the glial cells, PGC-1α is essential for the maturation and proliferation of astrocytes, myelination by oligodendrocytes, and mitophagy and autophagy of microglia. PGC-1α is also necessary for synaptogenesis in the developing brain and the generation and maintenance of synapses in postnatal life. This review provides an outlook of recent studies on the role of PGC-1α in various cells in the central nervous system.

Neuroprotective Role of Nutritional Supplementation in Athletes

BACKGROUND

Neurodegenerative disorders belong to different classes of progressive/chronic conditions that affect the peripheral/central nervous system. It has been shown through studies that athletes who play sports involving repeated head trauma and sub-concussive impacts are more likely to experience neurological impairments and neurodegenerative disorders in the long run.

AIMS

The aim of the current narrative review article is to provide a summary of various nutraceuticals that offer promise in the prevention or management of sports-related injuries, especially concussions and mild traumatic brain injuries.

METHODS

This article reviews the various potential nutraceutical agents and their possible mechanisms in providing a beneficial effect in the injury recovery process. A thorough survey of the literature was carried out in the relevant databases to identify studies published in recent years. In the present article, we have also highlighted the major neurological disorders along with the associated nutraceutical(s) therapy in the management of disorders.

RESULTS

The exact pathological mechanism behind neurodegenerative conditions is complex as well as idiopathic. However, mitochondrial dysfunction, oxidative stress as well as intracellular calcium overload are some common reasons responsible for the progression of these neurodegenerative disorders. Owing to the multifaceted effects of nutraceuticals (complementary medicine), these supplements have gained importance as neuroprotective. These diet-based approaches inhibit different pathways in a physiological manner without eliciting adverse effects. Food habits and lifestyle of an individual also affect neurodegeneration.

CONCLUSION

Studies have shown nutraceuticals (such as resveratrol, omega-3-fatty acids) to be efficacious in terms of their neuroprotection against several neurodegenerative disorders and to be used as supplements in the management of traumatic brain injuries. Protection prior to injuries is needed since concussions or sub-concussive impacts may trigger several pathophysiological responses or cascades that can lead to long-term complications associated with CNS. Thus, the use of nutraceuticals as prophylactic treatment for neurological interventions has been proposed.

Resveratrol (RV): A pharmacological review and call for further research

Resveratrol (RV) is a well-known polyphenolic compound in various plants, including grape, peanut, and berry fruits, which is quite famous for its association with several health benefits such as anti-obesity, cardioprotective neuroprotective, antitumor, antidiabetic, antioxidants, anti-age effects, and glucose metabolism. Significantly, promising therapeutic properties have been reported in various cancer, neurodegeneration, and atherosclerosis and are regulated by several synergistic pathways that control oxidative stress, cell death, and inflammation. Similarly, RV possesses a strong anti-adipogenic effect by inhibiting fat accumulation processes and activating oxidative and lipolytic pathways, exhibiting their cardioprotective effects by inhibiting platelet aggregation. The RV also shows significant antibacterial effects against various food-borne pathogens (Listeria, Campylobacter, Staphylococcus aureus, and E. coli) by inhibiting an electron transport chain (ETC) and F0F1-ATPase, which decreases the production of cellular energy that leads to the spread of pathogens. After collecting and analyzing scientific literature, it may be concluded that RV is well tolerated and favorably affects cardiovascular, neurological, and diabetic disorders. As such, it is possible that RV can be considered the best nutritional additive and a complementary drug, especially a therapeutic candidate. Therefore, this review would increase knowledge about the blend of RV as well as inspire researchers around the world to consider RV as a pharmaceutical drug to combat future health crises against various inhumane diseases. In the future, this article will be aware of discoveries about the potential of this promising natural compound as the best nutraceuticals and therapeutic drugs in medicine.

Beneficial Effects of Exogenous Ketogenic Supplements on Aging Processes and Age-Related Neurodegenerative Diseases

Life expectancy of humans has increased continuously up to the present days, but their health status (healthspan) was not enhanced by similar extent. To decrease enormous medical, economical and psychological burden that arise from this discrepancy, improvement of healthspan is needed that leads to delaying both aging processes and development of age-related diseases, thereby extending lifespan. Thus, development of new therapeutic tools to alleviate aging processes and related diseases and to increase life expectancy is a topic of increasing interest. It is widely accepted that ketosis (increased blood ketone body levels, e.g., β-hydroxybutyrate) can generate neuroprotective effects. Ketosis-evoked neuroprotective effects may lead to improvement in health status and delay both aging and the development of related diseases through improving mitochondrial function, antioxidant and anti-inflammatory effects, histone and non-histone acetylation, β-hydroxybutyrylation of histones, modulation of neurotransmitter systems and RNA functions. Administration of exogenous ketogenic supplements was proven to be an effective method to induce and maintain a healthy state of nutritional ketosis. Consequently, exogenous ketogenic supplements, such as ketone salts and ketone esters, may mitigate aging processes, delay the onset of age-associated diseases and extend lifespan through ketosis. The aim of this review is to summarize the main hallmarks of aging processes and certain signaling pathways in association with (putative) beneficial influences of exogenous ketogenic supplements-evoked ketosis on lifespan, aging processes, the most common age-related neurodegenerative diseases (Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis), as well as impaired learning and memory functions.

Locomotor deficits in a mouse model of ALS are paralleled by loss of V1-interneuron connections onto fast motor neurons

ALS is characterized by progressive inability to execute movements. Motor neurons innervating fast-twitch muscle-fibers preferentially degenerate. The reason for this differential vulnerability and its consequences on motor output is not known. Here, we uncover that fast motor neurons receive stronger inhibitory synaptic inputs than slow motor neurons, and disease progression in the SOD1G93A mouse model leads to specific loss of inhibitory synapses onto fast motor neurons. Inhibitory V1 interneurons show similar innervation pattern and loss of synapses. Moreover, from postnatal day 63, there is a loss of V1 interneurons in the SOD1G93A mouse. The V1 interneuron degeneration appears before motor neuron death and is paralleled by the development of a specific locomotor deficit affecting speed and limb coordination. This distinct ALS-induced locomotor deficit is phenocopied in wild-type mice but not in SOD1G93A mice after appearing of the locomotor phenotype when V1 spinal interneurons are silenced. Our study identifies a potential source of non-autonomous motor neuronal vulnerability in ALS and links ALS-induced changes in locomotor phenotype to inhibitory V1-interneurons.

Sirtuins as pharmacological targets in neurodegenerative and neuropsychiatric disorders

Histone deacetylases (HDACs) are enzymes that regulate several processes, such as transcription, cell proliferation, differentiation and development. HDACs are classified as either Zn²⁺ -dependent or NAD⁺ -dependent enzymes. Over the years, experimental and clinical evidence has demonstrated that HDAC modulation is a critical process in neurodegenerative and psychiatric disorders. Nevertheless, most of the studies have focused on the role of Zn²⁺ -dependent HDACs in the development of these diseases, although there is growing evidence showing that the NAD⁺ -dependent HDACs, known as sirtuins, are also very promising targets. This possibility has been strengthened by reports of decreased levels of NAD⁺ in CNS disorders, which can lead to alterations in sirtuin activation and therefore result in increased pathology. In this review, we discuss the role of sirtuins in neurodegenerative and neuropsychiatric disorders as well the possible rationale for them to be considered as pharmacological targets in future therapeutic interventions.

Downregulating carnitine palmitoyl transferase 1 affects disease progression in the SOD1 G93A mouse model of ALS

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease characterized by death of motor neurons. The etiology and pathogenesis remains elusive despite decades of intensive research. Herein, we report that dysregulated metabolism plays a central role in the SOD1 G93A mouse model mimicking ALS. Specifically, we report that the activity of carnitine palmitoyl transferase 1 (CPT1) lipid metabolism is associated with disease progression. Downregulation of CPT1 activity by pharmacological and genetic methods results in amelioration of disease symptoms, inflammation, oxidative stress and mitochondrial function, whereas upregulation by high-fat diet or corticosterone results in a more aggressive disease progression. Finally, we show that downregulating CPT1 shifts the gut microbiota communities towards a protective phenotype in SOD1 G93A mice. These findings reveal that metabolism, and specifically CPT1 lipid metabolism plays a central role in the SOD1 G93A mouse model and shows that CPT1 might be a therapeutic target in ALS.

TBN improves motor function and prolongs survival in a TDP-43M337V mouse model of ALS

Amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD) are serious neurodegenerative diseases. Although their pathogenesis is unclear, the abnormal accumulation of TAR DNA-binding protein of 43 kDa (TDP-43) is a pathological feature that exists in almost all patients. Thus far, there is no drug that can cure ALS/FTLD. Tetramethylpyrazine nitrone (TBN) is a derivative of tetramethylapyrazine, derived from the traditional Chinese medicine Ligusticum chuanxiong, which has been widely proven to have therapeutic effects on models of various neurodegenerative diseases. TBN is currently under clinical investigation for several indications including a Phase II trial of ALS. Here, we explored the therapeutic effect of TBN in an ALS/FTLD mouse model. We injected the TDP-43 M337V virus into the striatum of mice unilaterally and bilaterally, and then administered 30 mg/kg TBN intragastrically to observe changes in behavior and survival rate of mice. The results showed that in mice with unilateral injection of TDP-43M337V into the striatum, TBN improved motor deficits and cognitive impairment in the early stages of disease progression. In mice with bilateral injection of TDP-43M337V into the striatum, TBN not only improved motor function but also prolonged survival rate. Moreover, we show that its therapeutic effect may be through activation of the Akt/mTOR/GSK-3β and AMPK/PGC-1α/Nrf2 signaling pathways. In summary, TBN is a promising agent for the treatment of ALS/FTLD.

Selective Activation of CNS and Reference PPARGC1A Promoters Is Associated with Distinct Gene Programs Relevant for Neurodegenerative Diseases

The transcriptional regulator peroxisome proliferator activated receptor gamma coactivator 1A (PGC-1α), encoded by PPARGC1A, has been linked to neurodegenerative diseases. Recently discovered CNS-specific PPARGC1A transcripts are initiated far upstream of the reference promoter, spliced to exon 2 of the reference gene, and are more abundant than reference gene transcripts in post-mortem human brain samples. The proteins translated from the CNS and reference transcripts differ only at their N-terminal regions. To dissect functional differences between CNS-specific isoforms and reference proteins, we used clustered regularly interspaced short palindromic repeats transcriptional activation (CRISPRa) for selective endogenous activation of the CNS or the reference promoters in SH-SY5Y cells. Expression and/or exon usage of the targets was ascertained by RNA sequencing. Compared to controls, more differentially expressed genes were observed after activation of the CNS than the reference gene promoter, while the magnitude of alternative exon usage was comparable between activation of the two promoters. Promoter-selective associations were observed with canonical signaling pathways, mitochondrial and nervous system functions and neurological diseases. The distinct N-terminal as well as the shared downstream regions of PGC-1α isoforms affect the exon usage of numerous genes. Furthermore, associations of risk genes of amyotrophic lateral sclerosis and Parkinson's disease were noted with differentially expressed genes resulting from the activation of the CNS and reference gene promoter, respectively. Thus, CNS-specific isoforms markedly amplify the biological functions of PPARGC1A and CNS-specific isoforms and reference proteins have common, complementary and selective functions relevant for neurodegenerative diseases.

Loss of FEZ1, a gene deleted in Jacobsen syndrome, causes locomotion defects and early mortality by impairing motor neuron development

FEZ1-mediated axonal transport plays important roles in central nervous system development but its involvement in the peripheral nervous system is not well-characterized. FEZ1 is deleted in Jacobsen syndrome (JS), an 11q terminal deletion developmental disorder. JS patients display impaired psychomotor skills, including gross and fine motor delay, suggesting that FEZ1 deletion may be responsible for these phenotypes, given its association with the development of motor-related circuits. Supporting this hypothesis, our data show that FEZ1 is selectively expressed in the rat brain and spinal cord. Its levels progressively increase over the developmental course of human motor neurons (MN) derived from embryonic stem cells. Deletion of FEZ1 strongly impaired axon and dendrite development, and significantly delayed the transport of synaptic proteins into developing neurites. Concurring with these observations, Drosophila unc-76 mutants showed severe locomotion impairments, accompanied by a strong reduction of synaptic boutons at neuromuscular junctions. These abnormalities were ameliorated by pharmacological activation of UNC-51/ATG1, a FEZ1-activating kinase, with rapamycin and metformin. Collectively, the results highlight a role for FEZ1 in MN development and implicate its deletion as an underlying cause of motor impairments in JS patients.

Tetramethylpyrazine nitrone improves motor dysfunction and pathological manifestations by activating the PGC-1α/Nrf2/HO-1 pathway in ALS mice

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive loss of upper and lower motor neurons that results in skeletal muscle atrophy, weakness and paralysis. Oxidative stress plays a key role in the pathogenesis of ALS, including familial forms of the disease arising from mutation of the gene coding for superoxide dismutase (SOD1). We have used the SOD1^G93A ALS mouse model to investigate the efficacy of 2-[[(1,1-dimethylethyl)oxidoimino]-methyl]-3,5,6-trimethylpyrazine (TBN), a novel tetramethylpyrazine derivative armed with a powerful free-radical scavenging nitrone moiety. TBN was administered to mice by intraperitoneal or intragastric injection after the onset of motor deficits. TBN slowed the progression of motor neuron disease as evidenced by improved motor performance, reduced spinal motor neuron loss and the associated glial response, and decreased skeletal muscle fiber denervation and fibrosis. TBN treatment activated mitochondrial antioxidant activity through the PGC-1α/Nrf2/HO-1 pathway and decreased the expression of human SOD1. These findings suggest that TBN holds promise as a therapeutic agent for ALS.

The role of lipids in the central nervous system and their pathological implications in amyotrophic lateral sclerosis

Lipids play an important role in the central nervous system (CNS). They contribute to the structural integrity and physical characteristics of cell and organelle membranes, act as bioactive signalling molecules, and are utilised as fuel sources for mitochondrial metabolism. The intricate homeostatic mechanisms underpinning lipid handling and metabolism across two major CNS cell types; neurons and astrocytes, are integral for cellular health and maintenance. Here, we explore the various roles of lipids in these two cell types. Given that changes in lipid metabolism have been identified in a number of neurodegenerative diseases, we also discuss changes in lipid handling and utilisation in the context of amyotrophic lateral sclerosis (ALS), in order to identify key cellular processes affected by the disease, and inform future areas of research.

Peroxisome Proliferator Activator Receptor Gamma Coactivator-1α Overexpression in Amyotrophic Lateral Sclerosis: A Tale of Two Transgenics

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder manifesting with upper and lower neuron loss, leading to impairments in voluntary muscle function and atrophy. Mitochondrial dysfunction in metabolism and morphology have been implicated in the pathogenesis of ALS, including atypical oxidative metabolism, reduced mitochondrial respiration in muscle, and protein aggregates in the mitochondrial outer membrane. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) plays an essential role in the regulation of mitochondrial biogenesis, the process by which existing mitochondria grow and divide. PGC-1α has been previously reported to be downregulated in the spinal cord of individuals with ALS. Towards targeting PGC-1α as a therapeutic mechanism, we have previously reported improved motor function and survival in the SOD1^G93A mouse model of ALS by neuron-specific over-expression of PGC-1α under a neuron-specific enolase (NSE) promoter. As pharmacological intervention targeting PGC-1α would result in whole-body upregulation of this transcriptional co-activator, in the current study we investigated whether global expression of PGC-1α is beneficial in a SOD1^G93A mouse model, by generating transgenic mice with PGC-1α transgene expression driven by an actin promoter. Actin-PGC-1α expression levels were assayed and confirmed in spinal cord, brain, muscle, liver, kidney, and spleen. To determine the therapeutic effects of global expression of PGC-1α, wild-type, actin-PGC-1α, SOD1^G93A, and actin-PGC-1α/SOD1^G93A animals were monitored for weight loss, motor performance by accelerating rotarod test, and survival. Overexpression of actin-PGC-1α did not confer significant improvement in these assessed outcomes. A potential explanation for this difference is that the actin promoter may not induce levels of PGC-1α relevant to disease pathophysiology in the cells that are specifically relevant to the pathogenesis of ALS. This evidence strongly supports future therapeutic approaches that target PGC-1α primarily in neurons.

The Role of Sex and Sex Hormones in Neurodegenerative Diseases

Neurodegenerative diseases (NDs) are a wide class of disorders of the central nervous system (CNS) with unknown etiology. Several factors were hypothesized to be involved in the pathogenesis of these diseases, including genetic and environmental factors. Many of these diseases show a sex prevalence and sex steroids were shown to have a role in the progression of specific forms of neurodegeneration. Estrogens were reported to be neuroprotective through their action on cognate nuclear and membrane receptors, while adverse effects of male hormones have been described on neuronal cells, although some data also suggest neuroprotective activities. The response of the CNS to sex steroids is a complex and integrated process that depends on (i) the type and amount of the cognate steroid receptor and (ii) the target cell type-either neurons, glia, or microglia. Moreover, the levels of sex steroids in the CNS fluctuate due to gonadal activities and to local metabolism and synthesis. Importantly, biochemical processes involved in the pathogenesis of NDs are increasingly being recognized as different between the two sexes and as influenced by sex steroids. The aim of this review is to present current state-of-the-art understanding on the potential role of sex steroids and their receptors on the onset and progression of major neurodegenerative disorders, namely, Alzheimer's disease, Parkinson's diseases, amyotrophic lateral sclerosis, and the peculiar motoneuron disease spinal and bulbar muscular atrophy, in which hormonal therapy is potentially useful as disease modifier.

Neurodegenerative Diseases - Is Metabolic Deficiency the Root Cause?

Neurodegenerative diseases, including Alzheimer, Parkinson, Huntington, and amyotrophic lateral sclerosis, are a prominent class of neurological diseases currently without a cure. They are characterized by an inexorable loss of a specific type of neurons. The selective vulnerability of specific neuronal clusters (typically a subcortical cluster) in the early stages, followed by the spread of the disease to higher cortical areas, is a typical pattern of disease progression. Neurodegenerative diseases share a range of molecular and cellular pathologies, including protein aggregation, mitochondrial dysfunction, glutamate toxicity, calcium load, proteolytic stress, oxidative stress, neuroinflammation, and aging, which contribute to neuronal death. Efforts to treat these diseases are often limited by the fact that they tend to address any one of the above pathological changes while ignoring others. Lack of clarity regarding a possible root cause that underlies all the above pathologies poses a significant challenge. In search of an integrative theory for neurodegenerative pathology, we hypothesize that metabolic deficiency in certain vulnerable neuronal clusters is the common underlying thread that links many dimensions of the disease. The current review aims to present an outline of such an integrative theory. We present a new perspective of neurodegenerative diseases as metabolic disorders at molecular, cellular, and systems levels. This helps to understand a common underlying mechanism of the many facets of the disease and may lead to more promising disease-modifying therapeutic interventions. Here, we briefly discuss the selective metabolic vulnerability of specific neuronal clusters and also the involvement of glia and vascular dysfunctions. Any failure in satisfaction of the metabolic demand by the neurons triggers a chain of events that precipitate various manifestations of neurodegenerative pathology.

The Expression of CNS-Specific PPARGC1A Transcripts Is Regulated by Hypoxia and a Variable GT Repeat Polymorphism

PPARGC1A encodes a transcriptional co-activator also termed peroxisome proliferator-activated receptor (PPAR) gamma coactivator 1-alpha (PGC-1α) which orchestrates multiple transcriptional programs. We have recently identified CNS-specific transcripts that are initiated far upstream of the reference gene (RG) promoter. The regulation of these isoforms may be relevant, as experimental and genetic studies implicated the PPARGC1A locus in neurodegenerative diseases. We therefore studied cis- and trans-regulatory elements activating the CNS promoter in comparison to the RG promoter in human neuronal cell lines. A naturally occurring variable guanidine thymidine (GT) repeat polymorphism within a microsatellite region in the proximal CNS promoter increases promoter activity in neuronal cell lines. Both the RG and the CNS promoters are activated by ESRRA, and the PGC-1α isoforms co-activate ESRRA on their own promoters suggesting an autoregulatory feedback loop. The proximal CNS, but not the RG, promoter is induced by FOXA2 and co-activated by PGC-1α resulting in robust activation. Furthermore, the CNS, but not the RG, promoter is targeted by the canonical hypoxia response involving HIF1A. Importantly, the transactivation by HIF1A is modulated by the size of the GT polymorphism. Increased expression of CNS-specific transcripts in response to hypoxia was observed in an established rat model, while RG transcripts encoding the full-length reference protein were not increased. These results suggest a role of the CNS region of the PPARGC1A locus in ischemia and warrant further studies in humans as the activity of the CNS promoter as well as its induction by hypoxia is subject to inter-individual variability due to the GT polymorphism.

Loss of mitochondrial protein CHCHD10 in skeletal muscle causes neuromuscular junction impairment

The neuromuscular junction (NMJ) is a synapse between motoneurons and skeletal muscles to control motor behavior. Acetylcholine receptors (AChRs) are restricted at the synaptic region for proper neurotransmission. Mutations in the mitochondrial CHCHD10 protein have been identified in multiple neuromuscular disorders; however, the physiological roles of CHCHD10 at NMJs remain elusive. Here, we report that CHCHD10 is highly expressed at the postsynapse of NMJs in skeletal muscles. Muscle conditional knockout CHCHD10 mice showed motor defects, abnormal neuromuscular transmission and NMJ structure. Mechanistically, we found that mitochondrial CHCHD10 is required for ATP production, which facilitates AChR expression and promotes agrin-induced AChR clustering. Importantly, ATP could effectively rescue the reduction of AChR clusters in the CHCHD10-ablated muscles. Our study elucidates a novel physiological role of CHCHD10 at the peripheral synapse. It suggests that mitochondria dysfunction contributes to neuromuscular pathogenesis.

Impairment between Oxidant and Antioxidant Systems: Short- and Long-term Implications for Athletes' Health

The role of oxidative stress, an imbalance between reactive oxygen species production (ROS) and antioxidants, has been described in several patho-physiological conditions, including cardiovascular, neurological diseases and cancer, thus impacting on individuals' lifelong health. Diet, environmental pollution, and physical activity can play a significant role in the oxidative balance of an organism. Even if physical training has proved to be able to counteract the negative effects caused by free radicals and to provide many health benefits, it is also known that intensive physical activity induces oxidative stress, inflammation, and free radical-mediated muscle damage. Indeed, variations in type, intensity, and duration of exercise training can activate different patterns of oxidant-antioxidant balance leading to different responses in terms of molecular and cellular damage. The aim of the present review is to discuss (1) the role of oxidative status in athletes in relation to exercise training practice, (2) the implications for muscle damage, (3) the long-term effect for neurodegenerative disease manifestations, (4) the role of antioxidant supplementations in preventing oxidative damages.

SIRT1 deacetylase in aging-induced neuromuscular degeneration and amyotrophic lateral sclerosis

SIRT1 is an NAD+ -dependent deacetylase that functions in a variety of cells and tissues to mitigate age-associated diseases. However, it remains unknown if SIRT1 also acts to prevent pathological changes that accrue in motor neurons during aging and amyotrophic lateral sclerosis (ALS). In this study, we show that SIRT1 expression decreases in the spinal cord of wild-type mice during normal aging. Using mouse models either overexpressing or lacking SIRT1 in motor neurons, we found that SIRT1 slows age-related degeneration of motor neurons' presynaptic sites at neuromuscular junctions (NMJs). Transcriptional analysis of spinal cord shows an overlap of greater than 90% when comparing alterations during normal aging with changes during ALS, revealing a substantial upregulation in immune and inflammatory response genes and a downregulation of synaptic transcripts. In addition, overexpressing SIRT1 in motor neurons delays progression to end-stage disease in high copy SOD1G93A mice. Thus, our findings suggest that there are parallels between ALS and aging, and interventions to impede aging may also slow the progression of this devastating disease.

Skeletal Muscle Modulates Huntington's Disease Pathogenesis in Mice: Role of Physical Exercise

Huntington’s disease (HD) is a monogenic fatal neurodegenerative disorder. However, there is increasing evidence that HD is a pleiotropic systemic disorder. In particular, skeletal muscle metabolism is greatly affected in HD, which in turn can have a major impact on whole-body metabolism and energetic balance. Throughout an unbiased mutagenesis approach in HD mice, we have found that Scn4a, a skeletal muscle–specific sodium channel gene, is a modifier of the disease. Mutations in Scn4a enhance HD disease progression and weight loss by accelerating muscle waste and cachexia, increasing skeletal muscle activity and energy demands. At the molecular level, Scn4a mutations activate AMP-activated protein kinase (AMPK), leading to a fibre switch towards more oxidative types. These adaptations seen in HD; Scn4a double mutant muscles are similar to those observed in healthy individuals after endurance exercise training regimes. This prompted us to assess the effects of an endurance exercise regime in HD mice, independently showing that skeletal muscle adaptations leading to the activation of AMPK are detrimental for HD pathogenesis. Although it is undeniable that physical exercise can lead to many health benefits, our work shows that, at least under certain situations such as in HD, an endurance exercise routine could be a detrimental therapeutic option.

Bojungikgi-tang Improves Muscle and Spinal Cord Function in an Amyotrophic Lateral Sclerosis Model

Amyotrophic lateral sclerosis (ALS) is a motor neuron disease characterized by progressive motor function impairment, dysphagia, and respiratory failure. Owing to the complexity of its pathogenic mechanisms, an effective therapy for ALS is lacking. Herbal medicines with multiple targets have good efficacy and low adverse reactions for the treatment of neurodegenerative diseases. In this study, the effects of Bojungikgi-tang (BJIGT), an herbal medicine with eight component herbs, on muscle and spinal cord function were evaluated in an ALS animal model. Animals were randomly divided into three groups: a non-transgenic group (nTg, n = 24), a hSOD1^G93A transgenic group (Tg, n = 24), and a hSOD1^G93A transgenic group in which 8-week-old mice were orally administered BJIGT (1 mg/g) once daily for 6 weeks (Tg+BJIGT, n = 24). The effects of BJIGT were evaluated using a rotarod test, foot-printing, and survival analyses based on Kaplan-Meier survival curves. To determine the biological mechanism underlying the effects of BJIGT in hSOD1^G93A mice, western blotting, transmission electron microscopy, and Bungarotoxin staining were used. BJIGT improved motor function and extended the survival duration of hSOD1^G93A mice. In addition, BJIGT had protective effects, including anti-oxidative and anti-inflammatory effects, in both the spinal cord and muscle of hSOD1^G93A mice. Our results demonstrated that BJIGT causes muscle atrophy and the denervation of neuromuscular junctions in the gastrocnemius of hSOD1^G93A mice. The components of BJIGT may alleviate the symptoms of ALS via different mechanisms, and accordingly, BJIGT treatment may be an effective therapeutic approach.

PGC-1α sparks the fire of neuroprotection against neurodegenerative disorders

Recently, growing evidence has demonstrated that peroxisome proliferator activated receptor γ (PPARγ) coactivator-1α (PGC-1α) is a superior transcriptional regulator that acts via controlling the expression of anti-oxidant enzymes and uncoupling proteins and inducing mitochondrial biogenesis, which plays a beneficial part in the central nervous system (CNS). Given the significance of PGC-1α, we summarize the current literature on the molecular mechanisms and roles of PGC-1α in the CNS. Thus, in this review, we first briefly introduce the basic characteristics regarding PGC-1α. We then depict some of its important cerebral functions and discuss upstream modulators, partners, and downstream effectors of the PGC-1α signaling pathway. Finally, we highlight recent progress in research on the involvement of PGC-1α in certain major neurodegenerative disorders (NDDs), including Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Collectively, the data presented here may be useful for supporting the future potential of PGC-1α as a therapeutic target.

Energy metabolism in ALS: an underappreciated opportunity?

Amyotrophic lateral sclerosis (ALS) is a relentlessly progressive and fatal neurodegenerative disorder that primarily affects motor neurons. Despite our increased understanding of the genetic factors contributing to ALS, no effective treatment is available. A growing body of evidence shows disturbances in energy metabolism in ALS. Moreover, the remarkable vulnerability of motor neurons to ATP depletion has become increasingly clear. Here, we review metabolic alterations present in ALS patients and models, discuss the selective vulnerability of motor neurons to energetic stress, and provide an overview of tested and emerging metabolic approaches to treat ALS. We believe that a further understanding of the metabolic biology of ALS can lead to the identification of novel therapeutic targets.

PGC-1α affects aging-related changes in muscle and motor function by modulating specific exercise-mediated changes in old mice

The age-related impairment in muscle function results in a drastic decline in motor coordination and mobility in elderly individuals. Regular physical activity is the only efficient intervention to prevent and treat this age-associated degeneration. However, the mechanisms that underlie the therapeutic effect of exercise in this context remain unclear. We assessed whether endurance exercise training in old age is sufficient to affect muscle and motor function. Moreover, as muscle peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) is a key regulatory hub in endurance exercise adaptation with decreased expression in old muscle, we studied the involvement of PGC-1α in the therapeutic effect of exercise in aging. Intriguingly, PGC-1α muscle-specific knockout and overexpression, respectively, precipitated and alleviated specific aspects of aging-related deterioration of muscle function in old mice, while other muscle dysfunctions remained unchanged upon PGC-1α modulation. Surprisingly, we discovered that muscle PGC-1α was not only involved in improving muscle endurance and mitochondrial remodeling, but also phenocopied endurance exercise training in advanced age by contributing to maintaining balance and motor coordination in old animals. Our data therefore suggest that the benefits of exercise, even when performed at old age, extend beyond skeletal muscle and are at least in part mediated by PGC-1α.

Neuronal Lipid Metabolism: Multiple Pathways Driving Functional Outcomes in Health and Disease

Lipids are a fundamental class of organic molecules implicated in a wide range of biological processes related to their structural diversity, and based on this can be broadly classified into five categories; fatty acids, triacylglycerols (TAGs), phospholipids, sterol lipids and sphingolipids. Different lipid classes play major roles in neuronal cell populations; they can be used as energy substrates, act as building blocks for cellular structural machinery, serve as bioactive molecules, or a combination of each. In amyotrophic lateral sclerosis (ALS), dysfunctions in lipid metabolism and function have been identified as potential drivers of pathogenesis. In particular, aberrant lipid metabolism is proposed to underlie denervation of neuromuscular junctions, mitochondrial dysfunction, excitotoxicity, impaired neuronal transport, cytoskeletal defects, inflammation and reduced neurotransmitter release. Here we review current knowledge of the roles of lipid metabolism and function in the CNS and discuss how modulating these pathways may offer novel therapeutic options for treating ALS.

Resveratrol alleviates motor and cognitive deficits and neuropathology in the A53T α-synuclein mouse model of Parkinson's disease

Resveratrol exerts neuroprotective effects on the A53T α-synuclein mouse model of Parkinson's disease.

Resveratrol Role in Autoimmune Disease-A Mini-Review

Autoimmune diseases are still considered to be pressing concerns due the fact that they are leaders in death and disability causes worldwide. Resveratrol is a polyphenol derived from a variety of foods and beverages, including red grapes and red wine. Anti-inflammatory, antioxidant, and antiaging properties of resveratrol have been reported, and in some animal and human studies this compound reduced and ameliorated the progression of autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, psoriasis, inflammatory bowel disease, and type 1 diabetes mellitus. Thus, this review aims to summarize and critically analyze the role of resveratrol in the modulation of several organ-specific or systemic autoimmune diseases.

Could Sirtuin Activities Modify ALS Onset and Progression?

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with a complex etiology. Sirtuins have been implicated as disease-modifying factors in several neurological disorders, and in the past decade, attempts have been made to check if manipulating Sirtuin activities and levels could confer benefit in terms of neuroprotection and survival in ALS models. The efforts have largely focused on mutant SOD1, and while limited in scope, the results were largely positive. Here, the body of work linking Sirtuins with ALS is reviewed, with discussions on how Sirtuins and their activities may impact on the major etiological mechanisms of ALS. Moving forward, it is important that the potentially beneficial effect of Sirtuins in ALS disease onset and progression are assessed in ALS models with TDP-43, FUS, and C9orf72 mutations.

Molecular Pathway to Protection From Age-Dependent Photoreceptor Degeneration in Mef2 Deficiency

Purpose

Photoreceptor degeneration in the retina is a major cause of blindness in humans. Elucidating mechanisms of degenerative and neuroprotective pathways in photoreceptors should afford identification and development of therapeutic strategies.

Methods

We used mouse genetic models and improved methods for retinal explant cultures. Retinas were enucleated from Mef2d^+/+ and Mef2d^−/− mice, stained for MEF2 proteins and outer nuclear layer thickness, and assayed for apoptotic cells. Chromatin immunoprecipitation (ChIP) assays revealed MEF2 binding, and RT-qPCR showed levels of transcription factors. We used AAV2 and electroporation to express genes in retinal explants and electroretinograms to assess photoreceptor functionality.

Results

We identify a prosurvival MEF2D-PGC1α pathway that plays a neuroprotective role in photoreceptors. We demonstrate that Mef2d^−/− mouse retinas manifest decreased expression of PGC1α and increased photoreceptor cell loss, resulting in the absence of light responses. Molecular repletion of PGC1α protects Mef2d^−/− photoreceptors and preserves light responsivity.

Conclusions

These results suggest that the MEF2-PGC1α cascade may represent a new therapeutic target for drugs designed to protect photoreceptors from developmental- and age-dependent loss.