Minocycline inhibits cytochrome c release and delays progression of amyotrophic lateral sclerosis in mice

Direct Interaction of Minocycline to p47phox Contributes to its Attenuation of TNF-α-Mediated Neuronal PC12 Cell Death: Experimental and Simulation Validation

Kaempferol illustrates an example of attempting to discover new treatments for neurodegeneration by investigating the potential efficacy of natural products. Despite the identification of several molecular targets for this bio-active compound, the precise underlying pathways are not well elucidated yet. Recently, it has been shown through pulldown assay that kaemferol directly interacts with p47phox, the organizer subunit of NADPH oxidase-2 (NOX2) complex. Hence, in this study, we used homology modelling, computational docking, mutation analysis, molecular dynamics simulations and free energy calculations to determine how kaempferol interacts with p47phox. Firstly, 3D structure of p47phox was generated using x-ray structures of its domains. Then, it was docked with kaempferol, and finally 100-ns molecular dynamics (MD) simulations were performed and the global properties like root-mean square deviation (RMSD) and root-mean square fluctuations (RMSF) were calculated. Literature survey and computational analysis of key interacting amino acid residues of p47phox provided insights into a possible binding site for kaempferol, approximately around Trp193 and Cys196 located within the N-terminal SH3 domain of p47phox. Moreover, free energy calculations indicated that in silico substitution of Trp193 and Cys196 with arginine and alanine, respectively, results in less favorable interaction corroborating their importance in binding with kaempferol. Taken together, these findings suggest that kaempferol directly attaches to N-SH3 domain p47 phox, with a subsequent diminution of p47phox protein-protein interaction and possibly attenuation of NOX2 complex assembly, which reduces reactive oxygen species (ROS) generation. These observations will be beneficial for researchers exploring neuroprotection and for the development of p47phox inhibitors.

Amyotrophic lateral sclerosis: exploring pathophysiology in the context of treatment

Amyotrophic lateral sclerosis (ALS) is a complex, neurodegenerative disorder in which alterations in structural, physiological, and metabolic parameters act synergistically. Over the last decade there has been a considerable focus on developing drugs to slow the progression of the disease. Despite this, only four disease-modifying therapies are approved in North America. Although additional research is required for a thorough understanding of ALS, we have accumulated a large amount of knowledge that could be better integrated into future clinical trials to accelerate drug development and provide patients with improved treatment options. It is likely that future, successful ALS treatments will take a multi-pronged therapeutic approach, targeting different pathways, akin to personalized medicine in oncology. In this review, we discuss the link between ALS pathophysiology and treatments, looking at the therapeutic failures as learning opportunities that can help us refine and optimize drug development.

Current state of neuroprotective therapy using antibiotics in human traumatic brain injury and animal models

TBI is a leading cause of death and disability in young people and older adults worldwide. There is no gold standard treatment for TBI besides surgical interventions and symptomatic relief. Post-injury infections, such as lower respiratory tract and surgical site infections or meningitis are frequent complications following TBI. Whether the use of preventive and/or symptomatic antibiotic therapy improves patient mortality and outcome is an ongoing matter of debate. In contrast, results from animal models of TBI suggest translational perspectives and support the hypothesis that antibiotics, independent of their anti-microbial activity, alleviate secondary injury and improve neurological outcomes. These beneficial effects were largely attributed to the inhibition of neuroinflammation and neuronal cell death. In this review, we briefly outline current treatment options, including antibiotic therapy, for patients with TBI. We then summarize the therapeutic effects of the most commonly tested antibiotics in TBI animal models, highlight studies identifying molecular targets of antibiotics, and discuss similarities and differences in their mechanistic modes of action.

Interleukin-1β converting enzyme (ICE): A comprehensive review on discovery and development of caspase-1 inhibitors

Caspase-1 is a critical mediator of the inflammatory process by activating various pro-inflammatory cytokines such as pro-IL-1β, IL-18 and IL-33. Uncontrolled activation of caspase-1 leads to various cytokines-mediated diseases. Thus, inhibition of Caspase-1 is considered therapeutically beneficial to halt the progression of such diseases. Currently, rilonacept, canakinumab and anakinra are in use for caspase-1-mediated autoinflammatory diseases. However, the poor pharmacokinetic profile of these peptides limits their use as therapeutic agents. Therefore, several peptidomimetic inhibitors have been developed, but only a few compounds (VX-740, VX-765) have advanced to clinical trials; because of their toxic profile. Several small molecule inhibitors have also been progressing based on the three-dimensional structure of caspase-1. However there is no successful candidate available clinically. In this perspective, we highlight the mechanism of caspase-1 activation, its therapeutic potential as a disease target and potential therapeutic strategies targeting caspase-1 with their limitations.

High-fat diet alters intestinal microbiota and induces endoplasmic reticulum stress via the activation of apoptosis and inflammation in blunt snout bream

The primary organ for absorbing dietary fat is the gut. High dietary lipid intake negatively affects health and absorption by causing fat deposition in the intestine. This research explores the effect of a high-fat diet (HFD) on intestinal microbiota and its connections with endoplasmic reticulum stress and inflammation. 60 fish (average weight: 45.84 ± 0.07 g) were randomly fed a control diet (6% fat) and a high-fat diet (12 % fat) in four replicates for 12 weeks. From the result, hepatosomatic index (HSI), Visceralsomatic index (VSI), abdominal fat (ADF), Intestosomatic index (ISI), mesenteric fat (MFI), Triglycerides (TG), total cholesterol (TC), non-esterified fatty acid (NEFA) content were substantially greater on HFD compared to the control diet. Moreover, fish provided the HFD significantly obtained lower superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities. In contrast, an opposite result was seen in malondialdehyde (MDA) content in comparison to the control. HFD significantly altered intestinal microbiota in blunt snout bream, characterized by an increased abundance of Aeromonas, Plesiomonas proteobacteria, and firmicutes with a reduced abundance of Cetobacterium and ZOR0006. The transcriptional levels of glucose-regulated protein 78 (grp78), inositol requiring enzyme 1 (ire1), spliced X box-binding protein 1 (xbp1), DnaJ heat shock protein family (Hsp40) member B9 (dnajb9), tumor necrosis factor alpha (tnf-α), nuclear factor-kappa B (nf-κb), monocyte chemoattractant protein-1 (mcp-1), and interleukin-6 (il-6) in the intestine were markedly upregulated in fish fed HFD than the control group. Also, the outcome was similar in bax, caspases-3, and caspases-9, ZO-1, Occludin-1, and Occludin-2 expressions. In conclusion, HFD could alter microbiota and facilitate chronic inflammatory signals via activating endoplasmic reticulum stress.

Advances in Neuropathic Pain Research: Selected Intracellular Factors as Potential Targets for Multidirectional Analgesics

Neuropathic pain is a complex and debilitating condition that affects millions of people worldwide. Unlike acute pain, which is short-term and starts suddenly in response to an injury, neuropathic pain arises from somatosensory nervous system damage or disease, is usually chronic, and makes every day functioning difficult, substantially reducing quality of life. The main reason for the lack of effective pharmacotherapies for neuropathic pain is its diverse etiology and the complex, still poorly understood, pathophysiological mechanism of its progression. Numerous experimental studies, including ours, conducted over the last several decades have shown that the development of neuropathic pain is based on disturbances in cell activity, imbalances in the production of pronociceptive factors, and changes in signaling pathways such as p38MAPK, ERK, JNK, NF-κB, PI3K, and NRF2, which could become important targets for pharmacotherapy in the future. Despite the availability of many different analgesics, relieving neuropathic pain is still extremely difficult and requires a multidirectional, individual approach. We would like to point out that an increasing amount of data indicates that nonselective compounds directed at more than one molecular target exert promising analgesic effects. In our review, we characterize four substances (minocycline, astaxanthin, fisetin, and peimine) with analgesic properties that result from a wide spectrum of actions, including the modulation of MAPKs and other factors. We would like to draw attention to these selected substances since, in preclinical studies, they show suitable analgesic properties in models of neuropathy of various etiologies, and, importantly, some are already used as dietary supplements; for example, astaxanthin and fisetin protect against oxidative stress and have anti-inflammatory properties. It is worth emphasizing that the results of behavioral tests also indicate their usefulness when combined with opioids, the effectiveness of which decreases when neuropathy develops. Moreover, these substances appear to have additional, beneficial properties for the treatment of diseases that frequently co-occur with neuropathic pain. Therefore, these substances provide hope for the development of modern pharmacological tools to not only treat symptoms but also restore the proper functioning of the human body.

FUS-dependent microRNA deregulations identify TRIB2 as a druggable target for ALS motor neurons

MicroRNAs (miRNAs) modulate mRNA expression, and their deregulation contributes to various diseases including amyotrophic lateral sclerosis (ALS). As fused in sarcoma (FUS) is a causal gene for ALS and regulates biogenesis of miRNAs, we systematically analyzed the miRNA repertoires in spinal cords and hippocampi from ALS-FUS mice to understand how FUS-dependent miRNA deregulation contributes to ALS. miRNA profiling identified differentially expressed miRNAs between different central nervous system (CNS) regions as well as disease states. Among the up-regulated miRNAs, miR-1197 targets the pro-survival pseudokinase Trib2. A reduced TRIB2 expression was observed in iPSC-derived motor neurons from ALS patients. Pharmacological stabilization of TRIB2 protein with a clinically approved cancer drug rescues the survival of iPSC-derived human motor neurons, including those from a sporadic ALS patient. Collectively, our data indicate that miRNA profiling can be used to probe the molecular mechanisms underlying selective vulnerability, and TRIB2 is a potential therapeutic target for ALS.

Therapeutic targeting of ALS pathways: Refocusing an incomplete picture

Numerous potential amyotrophic lateral sclerosis (ALS)-relevant pathways have been hypothesized and studied preclinically, with subsequent translation to clinical trial. However, few successes have been observed with only modest effects. Along with an improved but incomplete understanding of ALS as a neurodegenerative disease is the evolution of more sophisticated and diverse in vitro and in vivo preclinical modeling platforms, as well as clinical trial designs. We highlight proposed pathological pathways that have been major therapeutic targets for investigational compounds. It is likely that the failures of so many of these therapeutic compounds may not have occurred because of lack of efficacy but rather because of a lack of preclinical modeling that would help define an appropriate disease pathway, as well as a failure to establish target engagement. These challenges are compounded by shortcomings in clinical trial design, including lack of biomarkers that could predict clinical success and studies that are underpowered. Although research investments have provided abundant insights into new ALS-relevant pathways, most have not yet been developed more fully to result in clinical study. In this review, we detail some of the important, well-established pathways, the therapeutics targeting them, and the subsequent clinical design. With an understanding of some of the shortcomings in translational efforts over the last three decades of ALS investigation, we propose that scientists and clinicians may choose to revisit some of these therapeutic pathways reviewed here with an eye toward improving preclinical modeling, biomarker development, and the investment in more sophisticated clinical trial designs.

Anti-Inflammatory Effects of Miyako Bidens pilosa in a Mouse Model of Amyotrophic Lateral Sclerosis and Lipopolysaccharide-Stimulated BV-2 Microglia

Neuroinflammation is a fundamental feature in the pathogenesis of amyotrophic lateral sclerosis (ALS) and arises from the activation of astrocytes and microglial cells. Previously, we reported that Miyako Bidens pilosa extract (MBP) inhibited microglial activation and prolonged the life span in a human ALS-linked mutant superoxide dismutase-1 (SOD1G93A) transgenic mouse model of ALS (G93A mice). Herein, we evaluated the effect of MBP on microglial activation in the spinal cord of G93A mice and lipopolysaccharide-stimulated BV-2 microglial cells. The administration of MBP inhibited the upregulation of the M1-microglia/macrophage marker (interferon-γ receptor (IFN-γR)) and pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) in G93A mice. However, MBP did not affect the increase in the M2-microglia/macrophage marker (IL-13R) and anti-inflammatory cytokines (transforming growth factor (TGF)-β and IL-10) in G93A mice. BV-2 cell exposure to MBP resulted in a decrease in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium (MTT) reduction activity and bromodeoxyuridine incorporation, without an increase in the number of ethidium homodimer-1-stained dead cells. Moreover, MBP suppressed the production of lipopolysaccharide-induced pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in BV-2 cells. These results suggest that the selective suppression of M1-related pro-inflammatory cytokines is involved in the therapeutic potential of MBP in ALS model mice.

Microglial crosstalk with astrocytes and immune cells in amyotrophic lateral sclerosis

In recent years, biomedical research efforts aimed to unravel the mechanisms involved in motor neuron death that occurs in amyotrophic lateral sclerosis (ALS). While the main causes of disease progression were first sought in the motor neurons, more recent studies highlight the gliocentric theory demonstrating the pivotal role of microglia and astrocyte, but also of infiltrating immune cells, in the pathological processes that take place in the central nervous system microenvironment. From this point of view, microglia-astrocytes-lymphocytes crosstalk is fundamental to shape the microenvironment toward a pro-inflammatory one, enhancing neuronal damage. In this review, we dissect the current state-of-the-art knowledge of the microglial dialogue with other cell populations as one of the principal hallmarks of ALS progression. Particularly, we deeply investigate the microglia crosstalk with astrocytes and immune cells reporting in vitro and in vivo studies related to ALS mouse models and human patients. At last, we highlight the current experimental therapeutic approaches that aim to modulate microglial phenotype to revert the microenvironment, thus counteracting ALS progression.

The glial perspective of autism spectrum disorder convergent evidence from postmortem brain and PET studies

OBJECTIVE

The present study aimed to systematically and quantitatively review evidence derived from both postmortem brain and PET studies to explore the pathological role of glia induced neuroinflammation in the pathogenesis of ASD, and discuss the implications of these findings in relation to disease pathogenesis and therapeutic strategies.

METHOD

An online databases search was performed to collate postmortem studies and PET studies regarding glia induced neuroinflammation in ASD as compared to controls. Two authors independently conducted the literature search, study selection and data extraction. The discrepancies generated in these processes was resolved through robust discussions among all authors.

RESULT

The literature search yielded the identification of 619 records, from which 22 postmortem studies and 3 PET studies were identified as eligible for the qualitative synthesis. Meta-analysis of postmortem studies reported increased microglial number and microglia density as well as increased GFAP protein expression and GFAP mRNA expression in ASD subjects as compared to controls. Three PET studies produced different outcomes and emphasized different details, with one reported increased and two reported decreased TSPO expression in ASD subjects as compared to controls.

CONCLUSION

Both postmortem evidences and PET studies converged to support the involvement of glia induced neuroinflammation in the pathogenesis of ASD. The limited number of included studies along with the considerable heterogeneity of these studies prevented the development of firm conclusions and challenged the explanation of variability. Future research should prioritize the replication of current studies and the validation of current observations.

Recent advances to Neuroprotection: repurposing drugs against neuroinflammatory disorders

Cell death is a natural mechanism for biological clearance for the maintenance of homeostasis in a dynamic microenvironment of the central nervous system. Stress and various factors can lead to imbalance between cellular genesis and cell death leading to dysfunctionality and a number of neuropathological disorders. Drug repurposing can help bypass development time and cost. A complete understanding of drug actions and neuroinflammatory pathways can lead to effective control of neurodegenerative disorders. This review covers recent advances in various neuroinflammatory pathways understanding, biomarkers, and drug repurposing for neuroprotection.

The Physio-Pathological Role of Group I Metabotropic Glutamate Receptors Expressed by Microglia in Health and Disease with a Focus on Amyotrophic Lateral Sclerosis

Microglia cells are the resident immune cells of the central nervous system. They act as the first-line immune guardians of nervous tissue and central drivers of neuroinflammation. Any homeostatic alteration that can compromise neuron and tissue integrity could activate microglia. Once activated, microglia exhibit highly diverse phenotypes and functions related to either beneficial or harmful consequences. Microglia activation is associated with the release of protective or deleterious cytokines, chemokines, and growth factors that can in turn determine defensive or pathological outcomes. This scenario is complicated by the pathology-related specific phenotypes that microglia can assume, thus leading to the so-called disease-associated microglia phenotypes. Microglia express several receptors that regulate the balance between pro- and anti-inflammatory features, sometimes exerting opposite actions on microglial functions according to specific conditions. In this context, group I metabotropic glutamate receptors (mGluRs) are molecular structures that may contribute to the modulation of the reactive phenotype of microglia cells, and this is worthy of exploration. Here, we summarize the role of group I mGluRs in shaping microglia cells' phenotype in specific physio-pathological conditions, including some neurodegenerative disorders. A significant section of the review is specifically focused on amyotrophic lateral sclerosis (ALS) since it represents an entirely unexplored topic of research in the field.

The Crosstalk between Microbiome and Mitochondrial Homeostasis in Neurodegeneration

Mitochondria are highly dynamic organelles that serve as the primary cellular energy-generating system. Apart from ATP production, they are essential for many biological processes, including calcium homeostasis, lipid biogenesis, ROS regulation and programmed cell death, which collectively render them invaluable for neuronal integrity and function. Emerging evidence indicates that mitochondrial dysfunction and altered mitochondrial dynamics are crucial hallmarks of a wide variety of neurodevelopmental and neurodegenerative conditions. At the same time, the gut microbiome has been implicated in the pathogenesis of several neurodegenerative disorders due to the bidirectional communication between the gut and the central nervous system, known as the gut-brain axis. Here we summarize new insights into the complex interplay between mitochondria, gut microbiota and neurodegeneration, and we refer to animal models that could elucidate the underlying mechanisms, as well as novel interventions to tackle age-related neurodegenerative conditions, based on this intricate network.

Novel therapeutic approaches for motor neuron disease

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that leads to the neurodegeneration and death of upper and lower motor neurons (MNs). Although MNs are the main cells involved in the process of neurodegeneration, a growing body of evidence points toward other cell types as concurrent to disease initiation and propagation. Given the current absence of effective therapies, the quest for other therapeutic targets remains open and still challenges the scientific community. Both neuronal and extra-neuronal mechanisms of cellular stress and damage have been studied and have posed the basis for the development of novel therapies that have been investigated on both animal models and humans. In this chapter, a thorough review of the main mechanisms of cellular damage and the respective therapeutic attempts targeting them is reported. The main areas covered include neuroinflammation, protein aggregation, RNA metabolism, and oxidative stress.

Zebrafish as a potential model for stroke: A comparative study with standardized models

Animal models of cerebral ischemia have improved our understanding of the pathophysiology and mechanisms involved in stroke, as well as the investigation of potential therapies. The potential of zebrafish to model human diseases has become increasingly evident. The availability of these models allows for an increased understanding of the role of chemical exposure in human conditions and provides essential tools for mechanistic studies of disease. To evaluate the potential neuroprotective properties of minocycline against ischemia and reperfusion injury in zebrafish and compare them with other standardized models. In vitro studies with BV-2 cells were performed, and mammalian transient middle cerebral artery occlusion (tMCAO) was used as a comparative standard with the zebrafish stroke model. Animals were subjected to ischemia and reperfusion injury protocols and treated with minocycline. Infarction size, cytokine levels, oxidative stress, glutamate toxicity, and immunofluorescence for microglial activation, and behavioral test results were determined and compared. Administration of minocycline provided significant protection in the three stroke models in different parameters analyzed. Both experimental models complement each other in their particularities. The proposal also strengthens the findings in the literature in rodent models and allows the validation of alternative models so that they can be used in further research involving diseases with ischemia and reperfusion injury.

Systematic Review of the Therapeutic Role of Apoptotic Inhibitors in Neurodegeneration and Their Potential Use in Schizophrenia

Schizophrenia (SZ) is a deleterious brain disorder affecting cognition, emotion and reality perception. The most widely accepted neurochemical-hypothesis is the imbalance of neurotransmitter-systems. Depleted GABAergic-inhibitory function might produce a regionally-located dopaminergic and glutamatergic-storm in the brain. The dopaminergic-release may underlie the positive psychotic-symptoms while the glutamatergic-release could prompt the primary negative symptoms/cognitive deficits. This may occur due to excessive synaptic-pruning during the neurodevelopmental stages of adolescence/early adulthood. Thus, although SZ is not a neurodegenerative disease, it has been suggested that exaggerated dendritic-apoptosis could explain the limited neuroprogression around its onset. This apoptotic nature of SZ highlights the potential therapeutic action of anti-apoptotic drugs, especially at prodromal stages. If dysregulation of apoptotic mechanisms underlies the molecular basis of SZ, then anti-apoptotic molecules could be a prodromal therapeutic option to halt or prevent SZ. In fact, risk alleles related in apoptotic genes have been recently associated to SZ and shared molecular apoptotic changes are common in the main neurodegenerative disorders and SZ. PRISMA-guidelines were considered. Anti-apoptotic drugs are commonly applied in classic neurodegenerative disorders with promising results. Despite both the apoptotic-hallmarks of SZ and the widespread use of anti-apoptotic targets in neurodegeneration, there is a strikingly scarce number of studies investigating anti-apoptotic approaches in SZ. We analyzed the anti-apoptotic approaches conducted in neurodegeneration and the potential applications of such anti-apoptotic therapies as a promising novel therapeutic strategy, especially during early stages.

Antioxidant Therapeutic Strategies in Neurodegenerative Diseases

The distinguishing pathogenic features of neurodegenerative diseases include mitochondrial dysfunction and derived reactive oxygen species generation. The neural tissue is highly sensitive to oxidative stress and this is a prominent factor in both chronic and acute neurodegeneration. Based on this, therapeutic strategies using antioxidant molecules towards redox equilibrium have been widely used for the treatment of several brain pathologies. Globally, polyphenols, carotenes and vitamins are among the most typical exogenous antioxidant agents that have been tested in neurodegeneration as adjunctive therapies. However, other types of antioxidants, including hormones, such as the widely used melatonin, are also considered neuroprotective agents and have been used in different neurodegenerative contexts. This review highlights the most relevant mitochondrial antioxidant targets in the main neurodegenerative disorders including Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease and also in the less represented amyotrophic lateral sclerosis, as well as traumatic brain injury, while summarizing the latest randomized placebo-controlled trials.

Integration of glucose and cardiolipin anabolism confers radiation resistance of HCC

BACKGROUND AND AIMS

Poor response to ionizing radiation (IR) due to resistance remains a clinical challenge. Altered metabolism represents a defining characteristic of nearly all types of cancers. However, how radioresistance is linked to metabolic reprogramming remains elusive in hepatocellular carcinoma (HCC).

APPROACH AND RESULTS

Baseline radiation responsiveness of different HCC cells were identified and cells with acquired radio-resistance were generated. By performing proteomics, metabolomics, metabolic flux, and other functional studies, we depicted a metabolic phenotype that mediates radiation resistance in HCC, whereby increased glucose flux leads to glucose addiction in radioresistant HCC cells and a corresponding increase in glycerophospholipids biosynthesis to enhance the levels of cardiolipin. Accumulation of cardiolipin dampens the effectiveness of IR by inhibiting cytochrome c release to initiate apoptosis. Mechanistically, mammalian target of rapamycin complex 1 (mTORC1) signaling-mediated translational control of hypoxia inducible factor-1α (HIF-1α) and sterol regulatory element-binding protein-1 (SREBP1) remodels such metabolic cascade. Targeting mTORC1 or glucose to cardiolipin synthesis, in combination with IR, strongly diminishes tumor burden. Finally, activation of glucose metabolism predicts poor response to radiotherapy in cancer patients.

CONCLUSIONS

We demonstrate a link between radiation resistance and metabolic integration and suggest that metabolically dismantling the radioresistant features of tumors may provide potential combination approaches for radiotherapy in HCC.

Microglia in multiple sclerosis - pathogenesis and imaging

PURPOSE OF REVIEW

Microglia normally protects the central nervous system (CNS) against insults. However, their persistent activation in multiple sclerosis (MS) contributes to injury. Here, we review microglia activation in MS and their detection using positron emission tomography (PET).

RECENT FINDINGS

During lesion evolution and the progression of MS, microglia activity may contribute to neurotoxicity through the release of pro-inflammatory cytokines, reactive oxidative species, proteases and glutamate. A means to detect and monitor microglia activation in individuals living with MS is provided by positron emission tomography (PET) imaging using the mitochondrial 18-kDa translocator protein (TSPO) ligand. TSPO PET imaging shows increased microglial activation within the normal appearing white matter that precedes radiological signs of neurodegeneration measured by T2 lesion enlargement. PET-detected microglia activation increases with progression of MS. These findings demand the use of CNS penetrant inhibitors that affect microglia. Such therapies may include hydroxychloroquine that is recently reported in a small study to reduce the expected progression in primary progressive MS, and Bruton's tyrosine kinase inhibitors for which there are now eleven Phase 3 registered trials in MS.

SUMMARY

Microglial activation drives injury in MS. PET imaging with microglia-specific ligands offer new insights into progression of MS and as a monitor for treatment responses.

Minocycline treatment improves proteostasis during Drosophila aging via autophagy mediated by FOXO and Hsp70

Minocycline is a semi-synthetic tetracycline derivative antibiotic that has been examined for its non-antibiotic properties, such as anti-inflammatory, tumor-suppressive, and neuroprotective effects. In this study, we found that feeding minocycline to Drosophila improves proteostasis during organismal aging. Poly-ubiquitinated protein aggregates increase in the flight muscles as flies age, which are reduced in response to minocycline feeding. Minocycline feeding increases the expression of several autophagy genes and the activity of the autophagy/lysosomal pathway in Drosophila muscles. Interestingly, mutant flies lacking either FOXO or Hsp70 showed increased levels of poly-ubiquitinated protein aggregates with reduced autophagy/lysosomal activity, which was not reversed by minocycline feeding. Our findings suggest that minocycline may improve proteostasis in aging tissues via FOXO-Hsp70 axis, which highlights the multifaceted effects of minocycline as a therapeutic agent in age-associated features.

AAV Vector-Mediated Antibody Delivery (A-MAD) in the Central Nervous System

In the last four decades, monoclonal antibodies and their derivatives have emerged as a powerful class of therapeutics, largely due to their exquisite targeting specificity. Several clinical areas, most notably oncology and autoimmune disorders, have seen the successful introduction of monoclonal-based therapeutics. However, their adoption for treatment of Central Nervous System diseases has been comparatively slow, largely due to issues of efficient delivery resulting from limited permeability of the Blood Brain Barrier. Nevertheless, CNS diseases are becoming increasingly prevalent as societies age, accounting for ~6.5 million fatalities worldwide per year. Therefore, harnessing the full therapeutic potential of monoclonal antibodies (and their derivatives) in this clinical area has become a priority. Adeno-associated virus-based vectors (AAVs) are a potential solution to this problem. Preclinical studies have shown that AAV vector-mediated antibody delivery provides protection against a broad range of peripheral diseases, such as the human immunodeficiency virus (HIV), influenza and malaria. The parallel identification and optimization of AAV vector platforms which cross the Blood Brain Barrier with high efficiency, widely transducing the Central Nervous System and allowing high levels of local transgene production, has now opened a number of interesting scenarios for the development of AAV vector-mediated antibody delivery strategies to target Central Nervous System proteinopathies.

Revisiting Minocycline in Intracerebral Hemorrhage: Mechanisms and Clinical Translation

Intracerebral hemorrhage (ICH) is an important subtype of stroke with an unsatisfactory prognosis of high mortality and disability. Although many pre-clinical studies and clinical trials have been performed in the past decades, effective therapy that meaningfully improve prognosis and outcomes of ICH patients is still lacking. An active area of research is towards alleviating secondary brain injury after ICH through neuroprotective pharmaceuticals and in which minocycline is a promising candidate. Here, we will first discuss new insights into the protective mechanisms of minocycline for ICH including reducing iron-related toxicity, maintenance of blood-brain barrier, and alleviating different types of cell death from preclinical data, then consider its shortcomings. Finally, we will review clinical trial perspectives for minocycline in ICH. We hope that this summary and discussion about updated information on minocycline as a viable treatment for ICH can facilitate further investigations.

Minocycline can reduce testicular apoptosis related to varicocele in male rats

The current research aimed to assess the impacts of Minocycline on varicocele-induced regulation of apoptotic-related genes and oxidative stress in the testis of adult Wistar rats. Thirty-two rats were divided into 4 groups: sham, varicocele (VcI), varicocele treated with Minocycline (VcI + Mno) for 56 days and healthy rats treated with minocycline (Mno). After 8 weeks, the oxidative stress markers levels in serum were investigated, afterwards, the level of Bax and Bcl-2 expression were assessed through 'immunocytochemistry' and RT-qPCR assays. Also, the rate of apoptosis was evaluated through the TUNEL method. Johnson's score, 'the width of epithelium' and 'seminiferous tubules diameter' were ameliorated in the VcI + Mno group in comparison with the Vcl group. Administration of Minocycline raised the 'Glutathione peroxidase' and 'Superoxide dismutase' levels in serum and declined the Malondialdehyde level in serum (p = 0.001). Furthermore, current study represented that minocycline reduced Bax and enhanced the expression of Bcl-2 gene and protein in comparison with the Vcl group (p < 0.05). In addition, Minocycline administration significantly declined the rate of apoptosis in germ cells (p < 0.05). Our study demonstrated that the administration of Minocycline could improve testicular injury in varicocele-induced rats by its antioxidant activity.

Targeting Microglia to Treat Degenerative Eye Diseases

Microglia have been implicated in many degenerative eye disorders, including retinitis pigmentosa, age-related macular degeneration, glaucoma, diabetic retinopathy, uveitis, and retinal detachment. While the exact roles of microglia in these conditions are still being discovered, evidence from animal models suggests that they can modulate the course of disease. In this review, we highlight current strategies to target microglia in the eye and their potential as treatments for both rare and common ocular disorders. These approaches include depleting microglia with chemicals or radiation, reprogramming microglia using homeostatic signals or other small molecules, and inhibiting the downstream effects of microglia such as by blocking cytokine activity or phagocytosis. Finally, we describe areas of future research needed to fully exploit the therapeutic value of microglia in eye diseases.

Systemic LPS-induced microglial activation results in increased GABAergic tone: A mechanism of protection against neuroinflammation in the medial prefrontal cortex in mice

Neuroinflammation with excess microglial activation and synaptic dysfunction are early symptoms of most neurological diseases. However, how microglia-associated neuroinflammation regulates synaptic activity remains obscure. We report here that acute neuroinflammation induced by intraperitoneal injection of lipopolysaccharide (LPS) results in cell-type-specific increases in inhibitory postsynaptic currents in the glutamatergic, but not the GABAergic, neurons of medial prefrontal cortex (mPFC), coinciding with excessive microglial activation. LPS causes upregulation in levels of GABA_AR subunits, glutamine synthetase and vesicular GABA transporter, and downregulation in brain-derived neurotrophic factor (BDNF) and its receptor, pTrkB. Blockage of microglial activation by minocycline ameliorates LPS-induced abnormal expression of GABA signaling-related proteins and activity of synaptic and network. Moreover, minocycline prevents the mice from LPS-induced aberrant behavior, such as a reduction in total distance and time spent in the centre in the open field test; decreases in entries into the open arm of elevated-plus maze and in consumption of sucrose; increased immobility in the tail suspension test. Furthermore, upregulation of GABA signaling by tiagabine also prevents LPS-induced microglial activation and aberrant behavior. This study illustrates a mode of bidirectional constitutive signaling between the neural and immune compartments of the brain, and suggests that the mPFC is an important area for brain-immune system communication. Moreover, the present study highlights GABAergic signaling as a key therapeutic target for mitigating neuroinflammation-induced abnormal synaptic activity in the mPFC, together with the associated behavioral abnormalities.

Protective effects of apigenin on methylmercury-induced behavioral/neurochemical abnormalities and neurotoxicity in rats

Methylmercury (MeHg) is a neurotoxin that induces neurotoxicity and cell death in neurons. MeHg increases oligodendrocyte death, glial cell activation, and motor neuron demyelination in the motor cortex and spinal cord. As a result, MeHg plays an important role in developing neurocomplications similar to amyotrophic lateral sclerosis (ALS). Recent research has implicated c-JNK and p38MAPK overactivation in the pathogenesis of ALS. Apigenin (APG) is a flavonoid having anti-inflammatory, antioxidant, and c-JNK/p38MAPK inhibitory activities. The purpose of this study is to determine whether APG possesses neuroprotective effects in MeHg-induced neurotoxicity in adult rats associated with ALS-like neuropathological alterations. In the current study, the neurotoxin MeHg causes an ALS-like phenotype in Wistar rats after 21 days of oral administration at a dose of 5 mg/kg. Prolonged administration of APG (40 and 80 mg/kg) improved neurobehavioral parameters such as learning memory, cognition, motor coordination, and grip strength. This is mainly associated with the downregulation of c-JNK and p38MAPK signaling as well as the restoration of myelin basic protein within the brain. Furthermore, APG inhibited neuronal apoptotic markers (Bax, Bcl-2, and caspase-3), restored neurotransmitter imbalance, decreased inflammatory markers (TNF- and IL-1), and alleviated oxidative damage. As a result, the current study shows that APG has neuroprotective potential as a c-JNK and p38MAPK signaling inhibitor against MeHg-induced neurotoxicity in adult rats. Based on these promising findings, we suggested that APG could be a potential new therapeutic approach over other conventional therapeutic approaches for MeHg-induced neurotoxicity in neurobehavioral, molecular, and neurochemical abnormalities.

Minocycline Mitigation of Tremor Syndrome and Defect of Cognitive and Balance Induced by Harmaline

Introduction:

Minocycline has anti-inflammatory, anti-apoptotic, and anti-oxidant effects. Preclinical data suggest that minocycline could be beneficial for treating common neurological disorders, including Parkinson disease and multiple sclerosis.

Methods:

In this study, the effects of minocycline on harmaline-induced motor and cognitive impairments were studied in male Wistar rats. The rats were divided into four groups of ten animals each. Harmaline was used for the induction of Essential Tremor (ET). Minocycline (90 mg/kg, IP) was administered 30 minutes before the saline or harmaline. Tremor intensity, spontaneous locomotor activity, passive avoidance memory, anxiety-related behaviors, and motor function were assessed in the rats.

Results:

The results showed that minocycline could recover tremor intensity and step width but failed to recuperate the motor balance. The memory impairments observed in harmaline-treated rats were somewhat reversed by administration of minocycline. The cerebellum and inferior olive nucleus were studied for neuronal degeneration using histochemistry and transmission electron microscopy techniques. Harmaline caused ultrastructural changes and neuronal cell loss in inferior olive and cerebellar Purkinje cells. Minocycline exhibited neuroprotective changes on cerebellar Purkinje cells and inferior olivary neurons.

Conclusion:

These results open new therapeutic perspectives for motor and memory impairments in ET. However, further studies are needed to clarify the exact mechanisms.

Combined antioxidants and anti-inflammatory therapies fail to attenuate the early and late phases of cyclodextrin-induced cochlear damage and hearing loss

Niemann-Pick C1 (NPC1) is a fatal neurodegenerative disease caused by aberrant cholesterol metabolism. The progression of the disease can be slowed by removing excess cholesterol with high-doses of 2-hyroxypropyl-beta-cyclodextrin (HPβCD). Unfortunately, HPβCD causes hearing loss; the initial first phase involves a rapid destruction of outer hair cells (OHCs) while the second phase, occurring 4-6 weeks later, involves the destruction of inner hair cells (IHCs), pillar cells, collapse of the organ of Corti and spiral ganglion neuron degeneration. To determine whether the first and/or second phase of HPβCD-induced cochlear damage is linked, in part, to excess oxidative stress or neuroinflammation, rats were treated with a single-dose of 3000 mg/kg HPβCD alone or together with one of two combination therapies. Each combination therapy was administered from 2-days before to 6-weeks after the HPβCD treatment. Combination 1 consisted of minocycline, an antibiotic that suppresses neuroinflammation, and HK-2, a multifunctional redox modulator that suppresses oxidative stress. Combination 2 was comprised of minocycline plus N-acetyl cysteine (NAC), which upregulates glutathione, a potent antioxidant. To determine if either combination therapy could prevent HPβCD-induced hearing impairment and cochlear damage, distortion product otoacoustic emissions (DPOAE) were measured to assess OHC function and the cochlear compound action potential (CAP) was measured to assess the function of IHCs and auditory nerve fibers. Cochleograms were prepared to quantify the amount of OHC, IHC and pillar cell (PC) loss. HPβCD significantly reduced DPOAE and CAP amplitudes and caused significant OHC, IHC and OPC losses with losses greater in the high-frequency base of the cochlea than the apex. Neither minocycline + HK-2 (MIN+ HK-2) nor minocycline + NAC (MIN+NAC) prevented the loss of DPOAEs, CAPs, OHCs, IHCs or IPCs caused by HPβCD. These results suggest that oxidative stress and neuroinflammation are unlikely to play major roles in mediating the first or second phase of HPβCD-induced cochlear damage. Thus, HPβCD-induced ototoxicity must be mediated by some other unknown cell-death pathway possibly involving loss of trophic support from damaged support cells or disrupted cholesterol metabolism.

Bifunctional conducting polymer matrices with antibacterial and neuroprotective effects

Current trends in the field of neural tissue engineering include the design of advanced biomaterials combining excellent electrochemical performance with versatile biological characteristics. The purpose of this work was to develop an antibacterial and neuroprotective coating based on a conducting polymer - poly(3,4-ethylenedioxypyrrole) (PEDOP), loaded with an antibiotic agent - tetracycline (Tc). Employing an electrochemical technique to immobilize Tc within a growing polymer matrix allowed to fabricate robust PEDOP/Tc coatings with a high charge storage capacity (63.65 ± 6.05 mC/cm²), drug release efficiency (629.4 µg/cm² ± 62.7 µg/cm²), and low charge transfer resistance (2.4 ± 0.1 kΩ), able to deliver a stable electrical signal. PEDOP/Tc were found to exhibit strong antimicrobial effects against Gram-negative bacteria Escherichia coli, expressed through negligible adhesion, reduction in viability, and a characteristic elongation of bacterial cells. Cytocompatibility and neuroprotective effects were evaluated using a rat neuroblastoma B35 cell line, and were analyzed using MTT, cell cycle, and Annexin-V apoptosis assays. The presence of Tc was found to enhance neural cell viability and neurite outgrowth. The results confirmed that PEDOP/Tc can serve as an efficient neural electrode coating able to enhance charge transfer, as well as to exhibit bifunctional biological characteristics, different for eukaryotic and prokaryotic cells.

Oral Minocycline Therapy Improves Symptoms of Myalgic Encephalomyelitis, Especially in the Initial Disease Stage

Objective Central nervous system dysfunction associated with myalgic encephalomyelitis (ME) has been suggested to be the main cause of chronic fatigue syndrome. In animal models of chronic fatigue, minocycline was reported to act as a suppressor of neural inflammation. Minocycline may thus exert favorable therapeutic effects in patients with ME. Methods Oral minocycline (100 mg×2 on the first day, followed by 100 mg/day for 41 days) was administered to 100 patients with ME. The performance status score (0-9), orthostatic intolerance during the 10-min standing test, neurologic disequilibrium, and neuropathic pain were compared before and after treatment. Results After therapy completion, favorable effects were observed with a decrease in the performance status score of ≥2 points in 27 patients (27%). Before treatment, 6 of the 27 patients had orthostatic intolerance with an inability to complete the 10-min standing test; after treatment, this symptom resolved in 4 and improved in 2 patients. In addition, after treatment, postural orthostatic tachycardia resolved in five of eight patients, disequilibrium resolved in five of eight patients, and fibromyalgia or neuropathic pain was attenuated in four of five patients. The favorable effects appeared dependent on a shorter disease duration, primarily for a duration of less than three years and most frequently within six months of the disease onset. However, acute adverse effects with nausea and/or dizziness caused 38 patients (38%) to discontinue treatment in the first few days. Conclusion Oral minocycline therapy may be an effective treatment option for patients with ME, especially in the initial stage of the disease.

Contribution of Apaf-1 to the pathogenesis of cancer and neurodegenerative diseases

Deregulation of apoptosis is associated with various pathologies, such as neurodegenerative disorders at one end of the spectrum and cancer at the other end. Generally speaking, differentiated cells like cardiomyocytes, skeletal myocytes and neurons exhibit low levels of Apaf-1 (Apoptotic protease activating factor 1) protein suggesting that down-regulation of Apaf-1 is an important event contributing to the resistance of these cells to apoptosis. Nonetheless, upregulation of Apaf-1 has not emerged as a common phenomenon in pathologies associated with enhanced neuronal cell death, i.e., neurodegenerative diseases. In cancer, on the other hand, Apaf-1 downregulation is a common phenomenon, which occurs through various mechanisms including mRNA hyper-methylation, gene methylation, Apaf-1 localization in lipid rafts, inhibition by microRNAs, phosphorylation, and interaction with specific inhibitors. Due to the diversity of these mechanisms and involvement of other factors, defining the exact contribution of Apaf-1 to the development of cancer in general and neurodegenerative disorders, in particular, is complicated. The current review is an attempt to provide a comprehensive image of Apaf-1's contribution to the pathologies observed in cancer and neurodegenerative diseases with the emphasis on the therapeutic aspects of Apaf-1 as an important target in these pathologies.

In Vivo Imaging of Allografted Glial-Restricted Progenitor Cell Survival and Hydrogel Scaffold Biodegradation

Transplanted glial-restricted progenitor (GRP) cells have potential to focally replace defunct astrocytes and produce remyelinating oligodendrocytes to avert neuronal death and dysfunction. However, most central nervous system cell therapeutic paradigms are hampered by high initial cell death and a host anti-graft immune response. We show here that composite hyaluronic acid-based hydrogels of tunable mechanical strengths can significantly improve transplanted GRP survival and differentiation. Allogeneic GRPs expressing green fluorescent protein and firefly luciferase were scaffolded in optimized hydrogel formulations and transplanted intracerebrally into immunocompetent BALB/c mice followed by serial in vivo bioluminescent imaging and chemical exchange saturation transfer magnetic resonance imaging (CEST MRI). We demonstrate that gelatin-sensitive CEST MRI can be exploited to monitor hydrogel scaffold degradation in vivo for ∼5 weeks post transplantation without necessitating exogenous labeling. Hydrogel scaffolding of GRPs resulted in a 4.5-fold increase in transplanted cell survival at day 32 post transplantation compared to naked cells. Histological analysis showed significant enhancement of cell proliferation as well as Olig2⁺ and GFAP⁺ cell differentiation for scaffolded cells compared to naked cells, with reduced host immunoreactivity. Hence, hydrogel scaffolding of transplanted GRPs in conjunction with serial in vivo imaging of cell survival and hydrogel degradation has potential for further advances in glial cell therapy.

Stroke and immunotherapy: Potential mechanisms and its implications as immune-therapeutics

Ischemia or brain injuries are mostly associated with emergency admissions and huge mortality rates. Stroke is a fatal cerebrovascular malady and second top root of disability and death in both developing and developed countries with a projected rise of 24.9% (from 2010) by 2030. It's the most frequent cause of morbidities and systemic permanent morbidities due to its multi-organ systemic pathology. Brain edema or active immune response cause disturbed or abnormal systemic affects causing inflammatory damage leading to secondary infection and secondary immune response which leads to activation like pneumonia or urine tract infections. There are a variety of post stroke treatments available which claims their usefulness in reducing or inhibiting post stroke and recurrent stroke damage followed by heavy inflammatory actions. Stroke does change the quality of life and also ensures daily chronic rapid neurodegeneration and cognitive decline. The only approved therapies for stroke are alteplase and thrombectomy which is associated with adverse outcomes and are not a total cure for ischemic stroke. Stroke and immune response are reciprocal to the pathology and time of event and it progresses till untreated. The immune reaction during ischemia opens new doors for advanced targeted therapeutics. Nowadays stem cell therapy has shown better results in stroke-prone individuals. Few monoclonal antibodies like natalizumab have shown great impact on pre-clinical and clinical stroke trial studies. In this current review, we have explored an immunology of stroke, current therapeutic scenario and future potential targets as immunotherapeutic agents in stroke therapeutics.

Neuroprotective effect of minocycline against acute brain injury in clinical practice: A systematic review

Acute brain injury is a leading cause of morbidity and mortality worldwide. The term is inclusive of traumatic brain injury, cerebral ischemia, subarachnoid hemorrhage, and intracerebral hemorrhage. Current pharmacologic treatments have had minimal effect on improving neurological outcomes leading to a significant interest in the development neuroprotective agents. Minocycline is a second-generation tetracycline with high blood brain barrier penetrance due to its lipophilic properties. It functions across multiple molecular pathways involved in secondary-injury cascades following acute brain injury. Animal model studies suggest that minocycline might lead to improved neurologic outcomes, but few such trials exist in humans. Clinical investigations have been limited to small randomized trials in ischemic stroke patients which have not demonstrated a clear advantage in neurologic outcomes, but also have not been sufficiently powered to draw definitive conclusions. The potential neuroprotective effect of minocycline in the setting of traumatic brain injury, subarachnoid hemorrhage, and intracerebral hemorrhage have all been limited to pilot studies with phase II/III investigations pending. The authors aim to synthesize what is currently known about minocycline as a neuroprotective agent against acute brain injury in humans.

Potential of Antibiotics for the Treatment and Management of Parkinson Disease: An Overview

Evidences have emerged over the last 2 decades to ascertain the proof of concepts viz. mitochondrial dysfunction, inflammation-derived oxidative damage and cytokine-induced toxicity that play a significant role in Parkinson's disease (PD). The available pharmacotherapies for PD are mainly symptomatic and typically indications of L-DOPA to restrain dopamine deficiency and their consequences. In the 21st century, the role of the antibiotics has emerged at the forefront of medicine in health and human illness. There are several experimental and pre-clinical evidences that supported the potential use of antibiotic as neuroprotective agent. The astonishing effects of antibiotics and their neuroprotective properties against neurodegeneration and neuro-inflammation would be phenomenal for the development of effective therapy against PD. Antibiotics are also testified as useful not only to prevent the formation of alpha-synuclein but also act on mitochondrial dysfunction and neuro-inflammation. Thus, the possible therapy with antibiotics in PD would impact both the pathways leading to neuronal cell death in substantia nigra and pars compacta in midbrain. Moreover, the antibiotic based pharmacotherapy will open a scientific research passageway to add more to the evidence based and rational use of antibiotics for the treatment and management of PD and other neurodegenerative disorders.

Activated Microglia in the Rat Spinal Cord Following Peripheral Axon Injury Promote Glial and Neuronal Plasticity Which is Necessary for Long-Term Neuronal Survival

Following the transection of peripheral sympathetic preganglionic axons comprising the cervical sympathetic trunk (CST), we observe robust glial and neuronal plasticity at 1 week post-injury in the rat spinal cord intermediolateral cell column (IML), which houses the injured parent neuronal cell bodies. This plasticity contributes to neuroprotection, as no neuronal loss in the IML is present at 16 weeks post-injury. Here, we administered the antibiotic minocycline or vehicle (VEH) daily for 1 week after CST transection to investigate the role of activated microglia in IML glial and neuronal plasticity and subsequent neuronal survival. At 1 week post-injury, minocycline treatment did not alter microglia number in the IML, but led to a dampened microglia activation state. In addition, the increases in oligodendrocyte (OL) lineage cells and activated astrocytes following injury in VEH rats were attenuated in the minocycline-treated rats. Further, the normal downregulation of choline acetyltransferase (ChAT) in the injured neurons was blunted. At 16 weeks post-injury, fewer ChAT+ neurons were present in the minocycline-treated rats, suggesting that activated microglia together with the glial and neuronal plasticity at 1 week post-injury contribute to the long-term survival of the injured neurons. These results provide evidence for beneficial crosstalk between activated microglia and neurons as well as other glial cells in the cord following peripheral axon injury, which ultimately leads to neuroprotection. The influences of microglia activation in promoting neuronal survival should be considered when developing therapies to administer minocycline for the treatment of neurological pathologies.

Complementing Matrix-Assisted Laser Desorption Ionization-Mass Spectrometry Imaging with Chromatography Data for Improved Assignment of Isobaric and Isomeric Phospholipids Utilizing Trapped Ion Mobility-Mass Spectrometry

Lipids, such for example the multifaceted category of glycerophospholipids (GP), play a major role in many biological processes. High-resolution mass spectrometry is able to identify these highly diverse lipid species in combination with fragmentation experiments (MS/MS) on the basis of the accurate m/z and fragmentation pattern. However, for the differentiation of isomeric lipids or isobaric interferences, more elaborate separation methods are required. Especially for imaging techniques, such as matrix-assisted laser desorption/ionization (MALDI)-MS imaging, the identification is often exclusively based on the accurate m/z. Fragmentation via MS/MS increases the confidence in lipid annotation in imaging approaches. However, this is sometimes not feasible due to insufficient sensitivity and significantly prolonged analysis time. The use of a separation dimension such as trapped ion mobility spectrometry (TIMS) after ionization strengthens the confidence of the identification based on the collision cross section (CCS). Since CCS libraries are limited, a tissue-specific database was initially generated using hydrophilic interaction liquid chromatography-TIMS-MS. Using this database, the identification of isomeric lipid classes as well as isobaric interferences in a lipid class was performed using a mouse spleen sample in a workflow described in this study. Besides a CCS-based identification as an additional identification criterion for GP in general, the focus was on the distinction of the isomeric GP classes phosphatidylglycerol and bis(monoacylglycero)phosphate, as well as the differentiation of possible isobaric interferences based on the formation of adducts by MALDI-TIMS-MS imaging on a molecular level.

The Molecular Mechanism of Aluminum Phosphide poisoning in Cardiovascular Disease: Pathophysiology and Diagnostic Approach

Nowadays, poisoning with metal phosphides, especially aluminum phosphide (ALP), is one of the main health threats in human societies. Patients suffer from significant complications due to this type of poisoning, and the heart is one of the main organs targeted by ALP. Therefore, in this study, we discussed the effect of phosphine on cardiac function. This study is based on data obtained from PubMed, between 2002 and 2020. The key keywords included "Aluminum phosphide," "Oxidative Stress," "Mitochondria," "Cardiovascular disease," and "Treatment." The results showed that ALP produced reactive oxygen species (ROS) due to mitochondrial dysfunction. ROS production leads to red blood cell hemolysis, decreased ATP production, and induction of apoptosis in cardiomyocytes, which eventually results in cardiovascular disease. Since ALP has the most significant effect on cardiomyocytes, the use of appropriate treatment strategies to restore cell function can increase patients' survival.

Tolerance-inducing effect and properties of innate immune stimulation on chronic stress-induced behavioral abnormalities in mice

Over-activation of the innate immune system constitutes a risk factor for the development of nervous system disorders but may reduce the severity of these disorders by inducing tolerance effect. Here, we studied the tolerance-inducing effect and properties of innate immune stimulation on chronic social defeat stress (CSDS)-induced behavioral abnormalities in mice. A single injection of the innate immune enhancer lipopolysaccharide (LPS) one day before stress exposure prevented CSDS-induced impairment in social interaction and increased immobility time in the tail suspension test and forced swimming test. This effect was observed at varying doses (100, 500, and 1000 μg/kg) and peaked at 100 μg/kg. A single LPS injection (100 μg/kg) either one or five but not ten days before stress exposure prevented CSDS-induced behavioral abnormalities. A second LPS injection ten days after the first LPS injection, or a 2 × or 4 × LPS injections ten days before stress exposure also induced tolerance against stress-induced behavioral abnormalities. Our results furthermore showed that a single LPS injection one day before stress exposure skewed the neuroinflammatory response in the hippocampus and prefrontal cortex of CSDS-exposed mice toward an anti-inflammatory phenotype. Inhibiting the central innate immune response by pretreatment with minocycline or PLX3397 abrogated the tolerance-inducing effect of LPS preconditioning on CSDS-induced behavioral abnormalities and neuroinflammatory responses in the brain. These results provide evidence for a prophylactic effect of innate immune stimulation on stress-induced behavioral abnormalities via changes in microglial activation, which may help develop novel strategies for the prevention of stress-induced psychological disorders.

Minocycline in neurodegenerative and psychiatric diseases: An update

BACKGROUND AND PURPOSE

Minocycline is a broad-spectrum antibiotic, effective as a chronic treatment for recurrent bacterial infections. Beyond its antibiotic action, minocycline also has important anti-inflammatory, antioxidant and antiapoptotic properties. Its efficacy has therefore been evaluated in many neurodegenerative and psychiatric diseases that have an inflammatory basis. Our aim was to review preclinical and clinical studies performed in neurological and psychiatric diseases whose treatment involved the use of minocycline and thereby to discern the possible beneficial effect of minocycline in these disorders.

METHODS

Completed and ongoing preclinical studies and clinical trials of minocycline for both neurodegenerative diseases and psychiatric disorders, published from January 1995 to January 2020, were identified through searching relevant databases (https://www.ncbi.nlm.nih.gov/pubmed/, https://clinicaltrials.gov/). A total of 74 preclinical studies and 44 clinical trials and open-label studies were selected.

RESULTS

The results of the nearly 20 years of research identified are diverse. While minocycline mostly proved to be effective in animal models, clinical results showed divergent outcomes, with positive results in some studies counterbalanced by a number of cases with no significant improvements. Specific data for each disease are further individually described in this review.

CONCLUSIONS

Despite minocycline demonstrating antioxidant and anti-inflammatory effects, discrepancies between preclinical and clinical data indicate that we should be cautious in analyzing the outcomes. Improving and standardizing protocols and refining animal models could help us to determine if minocycline really is a useful drug in the treatment of these pathologies.

Minocycline reduces inflammatory response and cell death in a S100B retina degeneration model

BACKGROUND

Previous studies noted that intravitreal injection of S100B triggered a glaucoma-like degeneration of retina and optic nerve as well as microglia activation after 14 days. The precise role of microglia in our intravitreal S100B model is still unclear. Hence, microglia were inhibited through minocycline. The aim is to investigate whether microglia have a significant influence on the degeneration process or whether they are only a side effect in the model studied here.

METHODS

Minocycline was applied daily in rats by intraperitoneal injection using two different concentrations (13.5 mg/kg body weight, 25 mg/kg body weight). One day after treatment start, S100B or PBS was intravitreally injected in one eye per rat. The naïve groups received no injections. This resulted in a total of five groups (naïve n = 14, PBS n = 14, S100B n = 13, 13.5 mg/kg mino n = 15, 25 mg/kg mino n = 15). At day 14, electroretinogram measurements were performed, followed by immunofluorescence and label-free quantitative proteomics analysis. The focus of these investigations was on the survival of RGCs as well as their axons, the response of the microglia, and the identification of further pathological modes of action of S100B.

RESULTS

The best signal transmission was detected via ERG in the 13.5 mg/kg mino group. The inhibition of the microglia protected optic nerve neurofilaments and decreased the negative impact of S100B on RGCs. However, the minocycline treatment could not trigger complete protection of RGCs. Furthermore, in retina and optic nerve, the minocycline treatment reduced the number and activity of S100B-triggered microglia in a concentration-dependent manner. Proteomics analysis showed that S100B application led to numerous metabolic functions and cellular stress, mainly an increased inflammatory response, glycolysis, and mitochondrial dysfunction, which caused oxidative stress in the retina. Importantly, the protective capability of lower dose of minocycline was unraveled by suppressing the apoptotic, inflammatory, and the altered metabolic processes caused by S100B insult in the retina.

CONCLUSION

Intravitreally injected S100B not only led to a pro-inflammatory microglial reaction, but also a mitochondrial and metabolic dysfunction. Also, these results suggest that an excessive microglial response may be a significant degenerative factor, but not the only trigger for increased cell death.

Antibiotics with therapeutic effects on spinal cord injury: a review

Accumulating evidence indicates that a considerable number of antibiotics exert anti-inflammatory and neuroprotective effects in different central and peripheral nervous system diseases including spinal cord injury (SCI). Both clinical and preclinical studies on SCI have found therapeutic effects of antibiotics from different families on SCI. These include macrolides, minocycline, β-lactams, and dapsone, all of which have been found to improve SCI sequels and complications. These antibiotics may target similar signaling pathways such as reducing inflammatory microglial activity, promoting autophagy, inhibiting neuronal apoptosis, and modulating the SCI-related mitochondrial dysfunction. In this review paper, we will discuss the mechanisms underlying therapeutic effects of these antibiotics on SCI, which not only could supply vital information for investigators but also guide clinicians to consider administering these antibiotics as part of a multimodal therapeutic approach for management of SCI and its complications.

Chronic minocycline treatment exerts antidepressant effect, inhibits neuroinflammation, and modulates gut microbiota in mice

RATIONAL

Minocycline is a second-generation, semi-synthetic tetracycline, and has broad spectrum-antibacterial activity. Interestingly, many studies have demonstrated that minocycline is beneficial for depression, which may be due to its effects on neuroinflammation modulation. Recently, gut microbiota imbalance has been found in depression patient and animal models.

OBJECTIVES

Based on the fact of minocycline usually acting as an antibiotic and the relationship between depression, gut microbiota, and neuroinflammation, we designed this study to detect the effects of chronic minocycline treatment on antidepression, neuroinflammation, and gut microbiota modulation.

RESULTS

Our results showed that minocycline treatment for 4 weeks, not acute treatment, exerted antidepressant effect in mice exposed to unpredictable chronic mild stress (CUMS). Further results suggested that chronic minocycline treatment inhibited neuroinflammation of hippocampus and altered species abundance and metabolites of gut microbiota. Meantime, we found that chronic minocycline treatment ameliorated intestinal barrier disruption and reduced the bacteriological indexes, such as diamine oxidase, C-reaction protein, and endotoxin in peripheral blood of CUMS mice.

CONCLUSIONS

To sum up, our findings confirm that chronic minocycline treatment exerts the antidepressant effect, inhibits neuroinflammation, and modulates gut microbiota. All of these imply that the antidepressant mechanism of chronic minocycline treatment is maybe due to the combined action of neuroinflammation and gut microbiota modulation, which need further prospective studies.

What Are the Odds of Finding a COVID-19 Drug from a Lab Repurposing Screen?

Massive drug repurposing (or repositioning) campaigns are trying to find potential antiviral treatments for COVID-19. Many involve experimental or virtual screening of libraries of compounds previously proven safe in humans-"old drugs". In 20 years of these efforts in many other diseases, never has a new therapeutic hypothesis derived from screening of old drugs in a lab led to the drug being approved for the new indication.

Role of CGRP in Neuroimmune Interaction via NF-κB Signaling Genes in Glial Cells of Trigeminal Ganglia

Activation of the trigeminal system causes the release of various neuropeptides, cytokines, and other immune mediators. Calcitonin gene-related peptide (CGRP), which is a potent algogenic mediator, is expressed in the peripheral sensory neurons of trigeminal ganglion (TG). It affects the inflammatory responses and pain sensitivity by modulating the activity of glial cells. The primary aim of this study was to use array analysis to investigate the effect of CGRP on the glial cells of TG in regulating nuclear factor kappa B (NF-κB) signaling genes and to further check if CGRP in the TG can affect neuron-glia activation in the spinal trigeminal nucleus caudalis. The glial cells of TG were stimulated with CGRP or Minocycline (Min) + CGRP. The effect on various genes involved in NF-κB signaling pathway was analyzed compared to no treatment control condition using a PCR array analysis. CGRP, Min + CGRP or saline was directly injected inside the TG and the effect on gene expression of Egr1, Myd88 and Akt1 and protein expression of cleaved Caspase3 (cleav Casp3) in the TG, and c-Fos and glial fibrillary acidic protein (GFAP) in the spinal section containing trigeminal nucleus caudalis was analyzed. Results showed that CGRP stimulation resulted in the modulation of several genes involved in the interleukin 1 signaling pathway and some genes of the tumor necrosis factor pathway. Minocycline pre-treatment resulted in the modulation of several genes in the glial cells, including anti-inflammatory genes, and neuronal activation markers. A mild increase in cleav Casp3 expression in TG and c-Fos and GFAP in the spinal trigeminal nucleus of CGRP injected animals was observed. These data provide evidence that glial cells can participate in neuroimmune interaction due to CGRP in the TG via NF-κB signaling pathway.

Hydroperoxylated vs Dihydroxylated Lipids: Differentiation of Isomeric Cardiolipin Oxidation Products by Multidimensional Separation Techniques

In recent years, cardiolipin (CL) oxidation products were recognized as potential markers for mitochondrial dysfunction in conjunction with age related diseases. The analysis of oxidized CL requires powerful analysis techniques due to high structural diversity. In addition, low concentrations of partly labile compounds pose a special challenge, supplemented by the occurrence of isomeric compounds, e.g., hydroperoxylated vs dihydroxylated products. Therefore, we present a hyphenated method based on liquid chromatography coupled to trapped ion mobility spectrometry (TIMS) for separation and tandem mass spectrometry (MS/MS) for structural characterization. This enables comprehensive analysis of an artificially oxidized CL extract of bovine heart. Isomeric oxidation products could be differentiated by mobility-resolved MS/MS fragmentation experiments. Our developed method could help to better understand the physiological role of oxidized CL.