Early derangement of axonal mitochondria occurs in a mouse model of progressive but not relapsing-remitting multiple sclerosis

Microglial suppression by myeloperoxidase inhibitor does not delay neurodegeneration in a mouse model of progressive multiple sclerosis

Drugs able to efficiently counteract the progression of multiple sclerosis (MS) are still an unmet need. Numerous preclinical evidence indicates that reactive oxygen-generating enzyme myeloperoxidase (MPO), expressed by neutrophils and microglia, might play a key role in neurodegenerative disorders. Then, the MPO inhibition has been evaluated in clinical trials in Parkinson's and multiple system atrophy patients, and a clinical trial for the treatment of amyotrophic lateral sclerosis is underway. The effects of MPO inhibition on MS patients have not yet been explored. In the present study, by adopting the NOD mouse model of progressive MS (PMS), we evaluated the pharmacological effects of the MPO inhibitor verdiperstat (also known as AZD3241) on functional, immune, and mitochondrial parameters during disease evolution. We found that daily treatment with verdiperstat did not affect the pattern of progression as well as survival, despite its ability to reduce mitochondrial reactive oxygen species and microglia activation in the spinal cord of immunized mice. Remarkably, verdiperstat did not affect adaptive immunity, neutrophils invasion as well as mitochondrial derangement in the spinal cords of immunized mice. Data suggest that microglia suppression is not sufficient to prevent disease evolution, corroborating the hypothesis that immune-independent components drive neurodegeneration in progressive MS.

Sex differences in progressive multiple sclerosis brain gene expression in oligodendrocytes and OPCs

Multiple sclerosis is a neurological autoimmune disease with sex-imbalanced incidence; in the USA, the disease is more likely to effect females at a ratio of 3:1. In addition, males are more likely to have a more severe disease course at time of diagnosis. Questions about both causes and downstream effects of this disparity remain. We aim to investigate gene expression differences at a cellular level while considering sex to discover fine-scale sex disparities. These investigations could provide new avenues for treatment targeting, or treatment planning based on sex. Public single-nuclei RNA-sequencing data from three publications of progressive MS including control brains were analysed using the Seurat R package. Differential gene and pathway expression was looked at both within a specific data set which has sub-lesion level sample dissection and across all studies to provide a broader lens. This allowed for the consideration of cell types and spatial positioning in relation to the interrogated lesion in some of the calculations. Our analysis showed expression changes in the female MS oligodendrocytes and oligodendrocyte progenitor cells compared to healthy controls, which were not observed in the corresponding male affected cells. Differentially up-regulated genes in females include increased HLA-A in the oligodendrocytes, and increased clusterin in the oligodendrocyte progenitor cells. There are also several mitochondrial genes in both the oligodendrocytes and oligodendrocyte progenitors which are up-regulated in females, including several directly involved in electron transport and which have previously been associated with neurodegenerative diseases. These results point to altered states in oligodendrocyte progenitors and oligodendrocytes that in combination with known physiological dissimilarities between sexes may denote different programming in males and females in response to the onset of demyelinating lesions. The potential for increased debris clearance mediated by clusterin and availability of oligodendrocyte progenitors in females may indicate an environment more primed for repair, potentially including remyelination. This could contribute to the disparity in etiology in females versus males.

Identification ATP5F1D as a Biomarker Linked to Diagnosis, Prognosis, and Immune Infiltration in Endometrial Cancer Based on Data-Independent Acquisition (DIA) Analysis

In developed countries, endometrial cancer (EC) is the most prevalent gynecological cancer. ATP5F1D is a subunit of ATP synthase, as well as an important component of the mitochondrial electron transport chain (ETC). ETC plays a compelling role in carcinogenesis. To date, little is known about the role of ATP5F1D in EC. We undertook data-independent acquisition mass spectrometry (DIA-MS) of 20 EC patients, comprising 10 high-grade and 10 low-grade cancer tissues. Biological functions of differentially expressed genes (DEGs) were analyzed by GO and KEGG. The expression level, clinicopathological features, diagnostic potency, prognostic value, RNA modifications, immune characteristics, and therapy response of ATP5F1D were investigated. In total, 77 DEGs were acquired by DIA analysis, which were closely related to regulating immune response and metabolic pathways. Among the five genes (NDUFB8, SLC26A2, RAF1, ATP5F1D, and GSTM5) involving in reactive oxygen species pathway, ATP5F1D showed the most significant differential expression (2.903-fold change). We found ATP5F1D had a high diagnostic value and was associated with a favorable prognosis in EC patients. After analyzing the RNA modifications of ATP5F1D, revealing a negative regulation between them. Additionally, ATP5F1D was closely related to tumor immune infiltration. Our results suggested T-cell dysfunction and TAM-M2 polarization might be the important mechanisms of ATP5F1D to facilitate tumor immune escape. Noticeably, EC patients with ATP5F1D-high expression had better immune treatment responses and were more sensitive to chemotherapy drugs. ATP5F1D can be used as a biomarker for diagnosis, prognosis, and immune infiltration of EC, and offers a crucial reference for personalized treatment of EC patients.

The role of the "gut microbiota-mitochondria" crosstalk in the pathogenesis of multiple sclerosis

Multiple Sclerosis (MS) is a neurologic autoimmune disease whose exact pathophysiologic mechanisms remain to be elucidated. Recent studies have shown that the onset and progression of MS are associated with dysbiosis of the gut microbiota. Similarly, a large body of evidence suggests that mitochondrial dysfunction may also have a significant impact on the development of MS. Endosymbiotic theory has found that human mitochondria are microbial in origin and share similar biological characteristics with the gut microbiota. Therefore, gut microbiota and mitochondrial function crosstalk are relevant in the development of MS. However, the relationship between gut microbiota and mitochondrial function in the development of MS is not fully understood. Therefore, by synthesizing previous relevant literature, this paper focuses on the changes in gut microbiota and metabolite composition in the development of MS and the possible mechanisms of the crosstalk between gut microbiota and mitochondrial function in the progression of MS, to provide new therapeutic approaches for the prevention or reduction of MS based on this crosstalk.

The mitochondriogenic but not the immunosuppressant effects of mTOR inhibitors prompt neuroprotection and delay disease evolution in a mouse model of progressive multiple sclerosis

INTRODUCTION

Purportedly, the progression of multiple sclerosis (MS) occurs when neurodegenerative processes due to derangement of axonal bioenergetics take over the autoimmune response. However, a clear picture of the causative interrelationship between autoimmunity and axonal mitochondrial dysfunction in progressive MS (PMS) pathogenesis waits to be provided.

METHODS

In the present study, by adopting the NOD mouse model of PMS, we compared the pharmacological effects of the immunosuppressants dexamethasone and fingolimod with those of mTOR inhibitors rapamycin and everolimus that, in addition to immunosuppression, also regulate mitochondrial functioning. Female Non-Obese Diabetic (NOD) mice were immunized with MOG35-55 and treated with drugs to evaluate functional, immune and mitochondrial parameters during disease evolution.

RESULTS

We found that dexamethasone and fingolimod did not affect the pattern of progression as well as survival. Conversely, mTOR inhibitors rapamycin and everolimus delayed disease progression and robustly extended survival of immunized mice. The same effects were obtained when treatment was delayed by 30 days after immunization. Remarkably, dexamethasone and fingolimod prompted the same degree of immunosuppression of rapamycin within both spleen and spinal cord of mice. However, only rapamycin prompted mitochondriogenesis by increasing mitochondrial content, and expression of several mitochondrial respiratory complex subunits, thereby preventing mtDNA reduction in the spinal cords of immunized mice. These pharmacodynamic effects were not reproduced in healthy NOD mice, suggesting a disease context-dependent pharmacodynamic effect.

DISCUSSION

Data corroborate the key role of mitochondriogenesis to treatment of MS progression, and for the first time disclose the translational potential of mTOR inhibitors in PMS therapy.