Up-regulation of TNF Receptor-associated Factor 7 after spinal cord injury in rats may have implication for neuronal apoptosis

Protective effect of TNIP2 on the inflammatory response of microglia after spinal cord injury in rats

BACKGROUND

Spinal cord injury (SCI) is a devastating disease that can lead to tissue loss and neurological dysfunction. TNIP2 is a negative regulator of NF-κB signaling due to its capacity to bind A20 and suppress inflammatory cytokines-induced NF-κB activation. However, the anti-inflammatory role of TNIP2 in SCI remains unclear. Our study's intention was to evaluate the effect of TNIP2 on the inflammatory response of microglia after spinal cord injury in rats.

METHODS

HE staining and Nissl staining were performed on day 3 following SCI to analyze the histological changes. To further investigate the functional changes of TNIP2 after SCI, we performed immunofluorescence staining experiments. The effect of LPS on TNIP2 expression in BV2 cells was examined by western blot. The levels of TNF-α, IL-1β, and IL-6 in spinal cord tissues of rats with SCI and in BV2 cells with LPS were measured by using qPCR.

RESULTS

TNIP2 expression was closely associated with the pathophysiology of SCI in rats, and TNIP2 was involved in regulating functional changes in microglia. TNIP2 expression was increased during SCI in rats and that overexpression of TNIP2 inhibited M1 polarization and pro-inflammatory cytokine production in microglia, which might ultimately protect against inflammatory responses through the MAPK and NF-κB signaling pathways.

CONCLUSIONS

The present study provides evidence for a role of TNIP2 in the regulation of inflammation in SCI and suggests that induction of TNIP2 expression alleviated the inflammatory response of microglia.

Spinal cord injury: molecular mechanisms and therapeutic interventions

Spinal cord injury (SCI) remains a severe condition with an extremely high disability rate. The challenges of SCI repair include its complex pathological mechanisms and the difficulties of neural regeneration in the central nervous system. In the past few decades, researchers have attempted to completely elucidate the pathological mechanism of SCI and identify effective strategies to promote axon regeneration and neural circuit remodeling, but the results have not been ideal. Recently, new pathological mechanisms of SCI, especially the interactions between immune and neural cell responses, have been revealed by single-cell sequencing and spatial transcriptome analysis. With the development of bioactive materials and stem cells, more attention has been focused on forming intermediate neural networks to promote neural regeneration and neural circuit reconstruction than on promoting axonal regeneration in the corticospinal tract. Furthermore, technologies to control physical parameters such as electricity, magnetism and ultrasound have been constantly innovated and applied in neural cell fate regulation. Among these advanced novel strategies and technologies, stem cell therapy, biomaterial transplantation, and electromagnetic stimulation have entered into the stage of clinical trials, and some of them have already been applied in clinical treatment. In this review, we outline the overall epidemiology and pathophysiology of SCI, expound on the latest research progress related to neural regeneration and circuit reconstruction in detail, and propose future directions for SCI repair and clinical applications.

Roles of physical exercise-induced MiR-126 in cardiovascular health of type 2 diabetes

Although physical activity is widely recommended for preventing and treating cardiovascular complications of type 2 diabetes mellitus (T2DM), the underlying mechanisms remain unknown. MicroRNA-126 (miR-126) is an angiogenetic regulator abundant in endothelial cells (ECs) and endothelial progenitor cells (EPCs). It is primarily involved in angiogenesis, inflammation and apoptosis for cardiovascular protection. According to recent studies, the levels of miR-126 in the myocardium and circulation are affected by exercise protocol. High-intensity interval training (HIIT) or moderate-and high-intensity aerobic exercise, whether acute or chronic, can increase circulating miR-126 in healthy adults. Chronic aerobic exercise can effectively rescue the reduction of myocardial and circulating miR-126 and vascular endothelial growth factor (VEGF) in diabetic mice against diabetic vascular injury. Resistance exercise can raise circulating VEGF levels, but it may have a little influence on circulating miR-126. The Several targets of miR-126 have been suggested for cardiovascular fitness, such as sprouty-related EVH1 domain-containing protein 1 (SPRED1), phosphoinositide-3-kinase regulatory subunit 2 (PIK3R2), vascular cell adhesion molecule 1 (VCAM1), high-mobility group box 1 (HMGB1), and tumor necrosis factor receptor-associated factor 7 (TRAF7). Here, we present a comprehensive review of the roles of miR-126 and its downstream proteins as exercise mechanisms, and propose that miR-126 can be applied as an exercise indicator for cardiovascular prescriptions and as a preventive or therapeutic target for cardiovascular complications in T2DM.

Ac-SDKP peptide improves functional recovery following spinal cord injury in a preclinical model

Damage to the spinal cord triggers a local complex inflammatory reaction that results in irreversible impairments or complete loss of motor function. The evidence suggested that inhibiting the pro-inflammatory macrophage/microglia (M1 subsets) and stimulating the anti-inflammatory macrophage/microglia (M2 subsets) are potential strategies for the treatment of neuroinflammation-related diseases. We evaluated the potentially protective effect of Ac-SDKP as an endogenous tetrapeptide on rat spinal cord injury (SCI). Wistar rats were subjected to a weight-drop contusion model and were treated with Ac-SDKP (0.8 mg/kg) given subcutaneously once a day for 7 days starting at two clinically relevant times, at 2 h or 6 h post-injury. The effect of Ac-SDKP was assessed by motor functional analysis, real-time PCR (CD86 and CD206 mRNA), western blot (caspase-3), ELISA (TNF-a, IL-10), and histological analysis (toluidine blue staining). Ac-SDKP improved locomotor recovery and rescue motor neuron loss after SCI. Moreover, a decreased in TNF-a level as well as caspase 3 protein levels occurred in the lesion epicenter of the spinal cord following treatment. In addition, CD206 mRNA expression level increased significantly in Ac-SDKP treated rats compared with SCI. Together these data suggest that Ac-SDKP might be a novel immunomodulatory drug. It may be beneficial for the treatment of SCI with regards to increasing CD206 gene expression and suppress inflammatory cytokine to improve motor function and reducing histopathological lesion.