Effect of necrostatin-1 on sciatic nerve crush injury in rat models

Indole-3-propionic acid promotes Schwann cell proliferation following peripheral nerve injury by activating the PI3K/AKT pathway

The proliferation of Schwann cells (SCs) is integral for axonal regeneration following peripheral nerve injury, and enhancing their proliferation can accelerate axonal regeneration. Indole-3-propionic acid (IPA), a metabolite of tryptophan synthesized by the intestinal microbiota, has potential in accelerating axonal regeneration in peripheral nerves. Nonetheless, the capacity of IPA to promote SC proliferation remains undetermined. Consequently, this study aimed to investigate the effects of IPA on SC proliferation and the underlying mechanisms. Therefore, we cultured RSC96 ​cells in vitro and used a Cell Counting Kit-8 (CCK8), an EdU Cell Proliferation Detection Kit (EdU), and a Cell Cycle and Apoptosis Assay Kit for the analyses. Additionally, we established a rat sciatic nerve crush injury model in vivo and performed immunofluorescence staining. These findings indicated that IPA enhanced SC proliferation. We further investigated the potential mechanism by which IPA promotes SC proliferation by conducting Western blotting and observed that IPA increased the levels of phosphorylated phosphatidylinositol 3-kinase/phosphatidylinositol 3-kinase (p-PI3K/PI3K) and phosphorylated protein kinase B/protein kinase B (p-AKT/AKT) in RSC96 ​cells, which suggested that IPA may promote the proliferation of RSC96 ​cells by activating the PI3K/AKT pathway. We cultured RSC96 ​cells in vitro, established a sciatic nerve crush model in vivo, and administered a PI3K inhibitor (LY294002) in combination with IPA treatment to validate this hypothesis. Our results revealed a reduction in the proliferation rate of RSC96 ​cells or SCs following the inhibition of p-PI3K/PI3K and p-AKT/AKT expression, as evidenced by the results of the EdU, CCK8 and immunofluorescence staining assays. These findings indicated that IPA may indeed promote SC proliferation through the activation of the PI3K/AKT pathway.

Biomechanical Evaluation of the Sheep Common Peroneal Nerve After Crush Injury

Axonotmesis, a common peripheral nerve injury in humans and animals, leads to significant biomechanical and physiological consequences. The lack of a standardized crushing protocol for complex animal models limits research and therapeutic translations for humans and clinically relevant animal species. This study aimed to assess the impact of different crushing forces on the biomechanical behavior of the sheep common peroneal nerve and to establish a force for standardized in vivo protocols. Fourteen nerves of equal length were harvested and preserved and their initial diameter measured. They were subjected to crushing forces of 0 N, 80 N, and 180 N for one minute. Post crushing, the diameter, ultimate tensile strength, displacement at rupture, stress, strain, and stiffness were evaluated. Results showed that increasing crushing forces significantly affected nerve biomechanical parameters. Nerves crushed with 180N displayed lower tensile strength, displacement, and stiffness but higher stress and strain, indicating greater physical damage and structural degradation. These findings suggest that 180N induces substantial nerve fiber rupture and disruption of nerve trunk support elements, making it a candidate force for an axonotmesis protocol in the ovine model. Future in vivo studies should validate its effectiveness in creating complete crush injuries with functional and histological consequences, facilitating protocol standardization and translational research.

Molecular characterization of PANoptosis-related genes as novel signatures for peripheral nerve injury based on time-series transcriptome sequencing

Programmed cell death (PCD) pathways play pivotal roles in the development and progression of peripheral nerve injury (PNI). PANoptosis, as a novel form of PCD pathway with key features of pyroptosis, apoptosis and necroptosis, is implicated in the pathogenesis of multiple neurologic diseases. This study aimed to identify PANoptosis-related biomarkers and characterize their molecular roles and immune landscape in PNI. PANoptosis-related genes (PRGs) were retrieved from Reactome pathway database and previous literatures. Differentially expressed PANoptosis-related genes (DEPRGs) were identified based on a time-series transcriptome sequencing dataset. DEPRGs were predicted to be enriched in inflammatory response, inflammatory complex, PCD and NOD-like receptor signaling pathway through GO, KEGG, Reactome and GSEA analysis. Hub genes, including Ripk3, Pycard and Il18, were then recognized through PPI network and multiple algorithms. The molecular regulatory mechanisms of hub genes were elucidated by transcription factor network and competing endogenous RNA network. Moreover, the immune cell landscape of hub genes was analyzed. Eventually, the expression levels of hub genes were verified through external dataset and animal model. Ripk3, Pycard and Il18 were remarkably upregulated in PNI samples, which were in consistent with the results of bioinformatic analysis. This study uncovered the molecular characterization of PANoptosis-related genes in PNI and illustrated the novel PANoptosis biomarkers for PNI.

An injectable thermosensitive pluronic F127 loaded-nanohydroxyapatite / Polydopamine for promoting sciatic nerve repair after crush injury

Peripheral nerve injury (PNI) remains an urgent issue due to its huge financial burden and high rate of disability. Here, an injectable HAP/PDA thermosensitive pluronic F-127 (PF-127) hydrogel is proposed for peripheral nerve repair. We investigated the surface characteristics of HAP/PDA and evaluated biocompatibility, cellular proliferation, differentiation, and apoptosis in vitro. After injecting the hydrogel into the injured site of rats, we recorded the recovery of motor function and judged the degree of nerves through electrophysiological and morphological changes. The hydrogel was found to accelerate the nerve regeneration. Collectively, the HAP/PDA thermosensitive PF-127 hydrogel has potential in promoting sciatic nerve repair.

Necrostatin-1: a promising compound for neurological disorders

Necrostatin-1, a small molecular alkaloid, was identified as an inhibitor of necroptosis in 2005. Investigating the fundamental mechanism of Necrostatin-1 and its role in various diseases is of great significance for scientific and clinical research. Accumulating evidence suggests that Necrostatin-1 plays a crucial role in numerous neurological disorders. This review aims to provide a comprehensive overview of the potential functions of Necrostatin-1 in various neurological disorders, offering valuable insights for future research.

RNA-seq based transcriptomic map reveals multiple pathways of necroptosis in treating myocardial ischemia reperfusion injury

Necroptosis has been shown to contribute to myocardial ischemia reperfusion injury (MIRI). This study aims to gain new insights into the signaling pathway of necroptosis in rat MIRI using RNA sequencing. MIRI was induced in male rats by ligating the left anterior descending coronary artery for 30 min, followed by reperfusion for 120 min. RNA sequencing was performed to obtain mRNA profiles of MIRI group and MIRI group treated with necrostatin-1 (Nec-1,an inhibitor of necroptosis). Differentially expressed genes (DEGs) were then identified. The DEGs were prominently enriched in the TNF-α signaling pathway, the MAPK signaling pathway and cytokine-cytokine receptor pathways. The majority of the results were associated with genes like Thumpd3,Egr2,Dot1l,Cyp1a1,Dbnl,which primarily regulate inflammatory response and apoptosis, particularly in myocardium. The above results suggested that Nec-1 might be involved in the regulation of necroptosis and the inflammatory response through the above-mentioned genes.