Therapeutic efficacy of cyclosporin A against spinal cord injury in rats with hyperglycemia

Targeting CaN/NFAT in Alzheimer's brain degeneration

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by a progressive loss of cognitive functions. While the exact causes of this debilitating disorder remain elusive, numerous investigations have characterized its two core pathologies: the presence of β-amyloid plaques and tau tangles. Additionally, multiple studies of postmortem brain tissue, as well as results from AD preclinical models, have consistently demonstrated the presence of a sustained inflammatory response. As the persistent immune response is associated with neurodegeneration, it became clear that it may also exacerbate other AD pathologies, providing a link between the initial deposition of β-amyloid plaques and the later development of neurofibrillary tangles. Initially discovered in T cells, the nuclear factor of activated T-cells (NFAT) is one of the main transcription factors driving the expression of inflammatory genes and thus regulating immune responses. NFAT-dependent production of inflammatory mediators is controlled by Ca2+-dependent protein phosphatase calcineurin (CaN), which dephosphorylates NFAT and promotes its transcriptional activity. A substantial body of evidence has demonstrated that aberrant CaN/NFAT signaling is linked to several pathologies observed in AD, including neuronal apoptosis, synaptic deficits, and glia activation. In view of this, the role of NFAT isoforms in AD has been linked to disease progression at different stages, some of which are paralleled to diminished cognitive status. The use of classical inhibitors of CaN/NFAT signaling, such as tacrolimus or cyclosporine, or adeno-associated viruses to specifically inhibit astrocytic NFAT activation, has alleviated some symptoms of AD by diminishing β-amyloid neurotoxicity and neuroinflammation. In this article, we discuss the recent findings related to the contribution of CaN/NFAT signaling to the progression of AD and highlight the possible benefits of targeting this pathway in AD treatment.

The role of immune cells and associated immunological factors in the immune response to spinal cord injury

Spinal cord injury (SCI) is a devastating neurological condition prevalent worldwide. Where the pathological mechanisms underlying SCI are concerned, we can distinguish between primary injury caused by initial mechanical damage and secondary injury characterized by a series of biological responses, such as vascular dysfunction, oxidative stress, neurotransmitter toxicity, lipid peroxidation, and immune-inflammatory response. Secondary injury causes further tissue loss and dysfunction, and the immune response appears to be the key molecular mechanism affecting injured tissue regeneration and functional recovery from SCI. Immune response after SCI involves the activation of different immune cells and the production of immunity-associated chemicals. With the development of new biological technologies, such as transcriptomics, the heterogeneity of immune cells and chemicals can be classified with greater precision. In this review, we focus on the current understanding of the heterogeneity of these immune components and the roles they play in SCI, including reactive astrogliosis and glial scar formation, neutrophil migration, macrophage transformation, resident microglia activation and proliferation, and the humoral immunity mediated by T and B cells. We also summarize findings from clinical trials of immunomodulatory therapies for SCI and briefly review promising therapeutic drugs currently being researched.

Cyclophilin D-induced mitochondrial impairment confers axonal injury after intracerebral hemorrhage in mice

The mitochondrial permeability transition pore is a nonspecific transmembrane channel. Inhibition of mitochondrial permeability transition pore opening has been shown to alleviate mitochondrial swelling, calcium overload, and axonal degeneration. Cyclophilin D is an important component of the mitochondrial permeability transition pore. Whether cyclophilin D participates in mitochondrial impairment and axonal injury after intracerebral hemorrhage is not clear. In this study, we established mouse models of intracerebral hemorrhage in vivo by injection of autologous blood and oxyhemoglobin into the striatum in Thy1-YFP mice, in which pyramidal neurons and axons express yellow fluorescent protein. We also simulated intracerebral hemorrhage in vitro in PC12 cells using oxyhemoglobin. We found that axonal degeneration in the early stage of intracerebral hemorrhage depended on mitochondrial swelling induced by cyclophilin D activation and mitochondrial permeability transition pore opening. We further investigated the mechanism underlying the role of cyclophilin D in mouse models and PC12 cell models of intracerebral hemorrhage. We found that both cyclosporin A inhibition and short hairpin RNA interference of cyclophilin D reduced mitochondrial permeability transition pore opening and mitochondrial injury. In addition, inhibition of cyclophilin D and mitochondrial permeability transition pore opening protected corticospinal tract integrity and alleviated motor dysfunction caused by intracerebral hemorrhage. Our findings suggest that cyclophilin D is used as a key mediator of axonal degeneration after intracerebral hemorrhage; inhibition of cyclophilin D expression can protect mitochondrial structure and function and further alleviate corticospinal tract injury and motor dysfunction after intracerebral hemorrhage. Our findings provide a therapeutic target for preventing axonal degeneration of white matter injury and subsequent functional impairment in central nervous diseases.

Network Pharmacology and Molecular Docking-Based Investigation of Potential Targets of Astragalus membranaceus and Angelica sinensis Compound Acting on Spinal Cord Injury

Background. Astragalus membranaceus (Huang-qi, AM) and Angelica sinensis (Dang-gui, AS) are common Chinese herbal medicines and have historically been used in spinal cord injury (SCI) therapies. However, the underlying molecular mechanisms of AM&AS remain little understood. The purpose of this research was to explore the bioactive components and the mechanisms of AM&AS in treating SCI according to network pharmacology and the molecular docking approach. Methods. AM&AS active ingredients were first searched from Traditional Chinese Medicine Systems Pharmacology (TCMSP) and Traditional Chinese Medicine Information Database (TCM-ID). Meanwhile, we collected relevant target genes of SCI through the GeneCards database, OMIM database, PharmGkb database, DurgBank database, and TDD database. By utilizing the STRING database, we constructed a network of protein-protein interactions (PPIs). In addition, we used R and STRING to perform GO and KEGG function enrichment analyses. Subsequently, AutoDock Vina was employed for a molecular docking study on the most active ingredients and most targeted molecules to validate the results of the network pharmacology analysis mentioned above. Result. The overall number of AM&AS active compounds identified was 22, while the number of SCI-related targets identified was 159. Then, the 4 key active ingredients were MOL000098 quercetin, MOL000422 kaempferol, MOL000354 isorhamnetin, and MOL000392 formononetin. A total of fourteen core targets were TP53, ESR1, MAPK1, MTC, HIF1A, HSP90AA1, FOS, MAPK14, STAT1, AKT1, EGFR, RELA, CCND1, and RB1. The KEGG enrichment analysis results indicated that lipid and atherosclerosis, PI3K-Akt signaling pathway, human cytomegalovirus infection, fluid shear stress, and atherosclerosis, etc., were enhanced with SCI development. Based on the analyses of docked molecules, four main active compounds had high affinity for the key targets. Conclusions. Altogether, it identified the mechanisms by which AM&AS was used for SCI treatment, namely, active ingredients, targets and signaling pathways. Consequently, further research into AM&AS treating SCI can be conducted on this scientific basis.

Akt-GSK3β-mPTP pathway regulates the mitochondrial dysfunction contributing to odontoblasts apoptosis induced by glucose oxidative stress

Diabetes Mellitus can cause dental pulp cells apoptosis by oxidative stress, and affect the integrity and function of dental pulp tissue. Mitochondria are the main attack targets of oxidative stress and have a critical role in apoptosis. However, whether mitochondria are involved in dental pulp damage caused by diabetes mellitus remains unclear. This study aimed to investigate the role of mitochondria in the apoptosis of odontoblast-like cell line (mDPC6T) induced by glucose oxidative stress, and to explore its possible mechanism. We established an oxidative stress model in vitro using glucose oxidase/glucose to simulate the pathological state under diabetic conditions. We found that the opening of mitochondrial permeability transition pore (mPTP) contributed to the apoptosis of mDPC6T treated with glucose oxidase, as evidenced by enhanced mitochondrial reactive oxygen species (mtROS) and intracellular Ca²⁺ disorder, significantly reduced mitochondrial membrane potential (MMP) and ATP production. Antioxidant N-acetylcysteine (NAC) or Cyclosporine A (mPTP inhibitor) blocked the mPTP opening, which significantly attenuated mitochondrial dysfunction and apoptosis induced by glucose oxidative stress. In addition, we found that glucose oxidative stress stimulated mPTP opening may through inhibition of Akt-GSK3β pathway. This study provides a new insight into the mitochondrial mechanism underlying diabetes-associated odontoblast-like cell apoptosis, laying a foundation for the prevention and treatment of diabetes-associated pulp injury.

Preclinical studies of mesenchymal stem cells transplantation in amyotrophic lateral sclerosis: a systemic review and metaanalysis

OBJECTIVES

To assess the quality of preclinical evidence for mesenchymal stromal cell (MSCs) therapy of amyotrophic lateral sclerosis (ALS), decide the effect size of MSCs treatment, and identify clinical parameters that associate with differences in MSCs effects.

METHODS

A literature search identified studies of MSCs in animal models of ALS. Four main indicators (age of onset, disease progression deceleration, survival time, hazard ratio reduction) obtained through specific neurobehavioral assessment, and 14 relative clinical parameters were extracted for metaanalysis and systematic review. Subgroup analysis and metaregression were performed to explore sources of heterogeneity.

RESULTS

A total of 25 studies and 41 independent treated arms were used for systematic review and metaanalysis. After adjusted by sensitivity analysis, the mean effect sizes were significantly improved by 0.28 for the age of onset, 0.25 for the disease progression deceleration, 0.54 for the survival time, and 0.48 for hazard ratio reduction. With further analysis, we demonstrated that both the clinical parameter of animal gender and immunosuppressive drug of cyclosporin A (CSA) had a close correlation with disease progression deceleration effect size.

CONCLUSIONS

These results showed that MSCs transplantation was beneficial for neurobehavioral improvement in the treatment of ALS animal model and recommended that all potential reparative roles of MSCs postdelivery, should be carefully considered and fused to maximize the effectiveness of MSCs therapy in ALS.

Spinal Cord Injury: Pathophysiology, Multimolecular Interactions, and Underlying Recovery Mechanisms

Spinal cord injury (SCI) is a destructive neurological and pathological state that causes major motor, sensory and autonomic dysfunctions. Its pathophysiology comprises acute and chronic phases and incorporates a cascade of destructive events such as ischemia, oxidative stress, inflammatory events, apoptotic pathways and locomotor dysfunctions. Many therapeutic strategies have been proposed to overcome neurodegenerative events and reduce secondary neuronal damage. Efforts have also been devoted in developing neuroprotective and neuro-regenerative therapies that promote neuronal recovery and outcome. Although varying degrees of success have been achieved, curative accomplishment is still elusive probably due to the complex healing and protective mechanisms involved. Thus, current understanding in this area must be assessed to formulate appropriate treatment modalities to improve SCI recovery. This review aims to promote the understanding of SCI pathophysiology, interrelated or interlinked multimolecular interactions and various methods of neuronal recovery i.e., neuroprotective, immunomodulatory and neuro-regenerative pathways and relevant approaches.

Therapeutic repair for spinal cord injury: combinatory approaches to address a multifaceted problem

The recent years saw the advent of promising preclinical strategies that combat the devastating effects of a spinal cord injury (SCI) that are progressing towards clinical trials. However, individually, these treatments produce only modest levels of recovery in animal models of SCI that could hamper their implementation into therapeutic strategies in spinal cord injured humans. Combinational strategies have demonstrated greater beneficial outcomes than their individual components alone by addressing multiple aspects of SCI pathology. Clinical trial designs in the future will eventually also need to align with this notion. The scenario will become increasingly complex as this happens and conversations between basic researchers and clinicians are required to ensure accurate study designs and functional readouts.

Targeting the mitochondrial permeability transition pore in traumatic central nervous system injury

The mitochondrion serves many functions in the central nervous system (CNS) and other organs beyond the well-recognized role of adenosine triphosphate (ATP) production. This includes calcium-dependent cell signaling, regulation of gene expression, synthesis and release of cytotoxic reactive oxygen species, and the release of cytochrome c and other apoptotic cell death factors. Traumatic injury to the CNS results in a rapid and, in some cases, sustained loss of mitochondrial function. One consequence of compromised mitochondrial function is induction of the mitochondrial permeability transition (mPT) state due to formation of the cyclosporine A sensitive permeability transition pore (mPTP). In this mini-review, we summarize evidence supporting the involvement of the mPTP as a mediator of mitochondrial and cellular demise following CNS traumatic injury and discuss the beneficial effects and limitations of the current ex-perimental strategies targeting the mPTP.