Therapeutic effect of and mechanisms underlying the effect of miR-195-5p on subarachnoid hemorrhage-induced vasospasm and brain injury in rats

Propofol alleviates M1 polarization and neuroinflammation of microglia in a subarachnoid hemorrhage model in vitro, by targeting the miR-140-5p/TREM-1/NF-κB signaling axis

Subarachnoid hemorrhage (SAH) is a devastating stroke caused by ruptured intracranial aneurysms, leading to blood accumulation around the brain. Early brain injury (EBI) within 72 h post-SAH worsens prognosis, primarily due to intense neuroinflammation. Microglia, pivotal in central nervous system defense and repair, undergo M1 to M2 polarization post-SAH, with M1 exacerbating neuroinflammation. Propofol (PPF), an anesthetic with anti-inflammatory properties, shows promise in mitigating neuroinflammation in SAH by modulating microglial activation. It likely acts through microRNAs like miR-140-5p, which attenuates microglial activation and inflammation by targeting TREM-1 and the NF-κB pathway. Understanding these mechanisms could lead to new therapeutic approaches for SAH-related EBI. In this study, BV-2 cell was used to establish in vitro model of SAH, and the expression of miR-140-5p and TREM-1 was detected after modeling. Microglial activity, apoptosis, the inflammatory pathway and response, oxidative damage, and M1/M2 polarization of microglia were evaluated by drug administration or transfection according to experimental groups. Finally, the targeting relationship between miR-140-5p and TREM-1 was verified by dual luciferase reporter assays, and the effect of PPF on the miR-140-5p/TREM-1/NF-κB signaling cascade was evaluated by RT‒qPCR or Western blotting. PPF effectively mitigates apoptosis, neuroinflammation, oxidative damage, and M1 microglial polarization in SAH. In SAH cells, PPF upregulates miR-140-5p and downregulates TREM-1. Mechanistically, PPF boosts miR-140-5p expression, while TREM-1, a downstream target of miR-140-5p, inhibits NF-κB signaling by regulating TREM-1, promoting M1 to M2 microglial polarization. Reduced miR-140-5p or increased TREM-1 counters PPF's therapeutic impact on SAH cells. In conclusion, PPF plays a neuroprotective role in SAH by regulating the miR-140-5p/TREM-1/NF-κB signaling axis to inhibit neuroinflammation and M1 polarization of microglia.

Regulation of Schwann cell proliferation and migration via miR-195-5p-induced Crebl2 downregulation upon peripheral nerve damage

Background

Schwann cells acquire a repair phenotype upon peripheral nerve injury (PNI), generating an optimal microenvironment that drives nerve repair. Multiple microRNAs (miRNAs) show differential expression in the damaged peripheral nerve, with critical regulatory functions in Schwann cell features. This study examined the time-dependent expression of miR-195-5p following PNI and demonstrated a marked dysregulation of miR-195-5p in the damaged sciatic nerve.

Methods

CCK-8 and EdU assays were used to evaluate the effect of miR-195-5 on Schwann cell viability and proliferation. Schwann cell migration was tested using Transwell and wound healing assays. The miR-195-5p agomir injection experiment was used to evaluate the function of miR-195-5p in vivo. The potential regulators and effects of miR-195-5p were identified through bioinformatics evaluation. The relationship between miR-195-5p and its target was tested using double fluorescence reporter gene analysis.

Results

In Schwann cells, high levels of miR-195-5p decreased viability and proliferation, while suppressed levels had the opposite effects. However, elevated miR-195-5p promoted Schwann cell migration determined by the Transwell and wound healing assays. In vivo injection of miR-195-5p agomir into rat sciatic nerves promote axon elongation after peripheral nerve injury by affecting Schwann cell distribution and myelin preservation. Bioinformatic assessment further revealed potential regulators and effectors for miR-195-5p, which were utilized to build a miR-195-5p-centered competing endogenous RNA network. Furthermore, miR-195-5p directly targeted cAMP response element binding protein-like 2 (Crebl2) mRNA via its 3'-untranslated region (3'-UTR) and downregulated Crebl2. Mechanistically, miR-195-5p modulated Schwann cell functions by repressing Crebl2.

Conclusion

The above findings suggested a vital role for miR-195-5p/Crebl2 in the regulation of Schwann cell phenotype after sciatic nerve damage, which may contribute to peripheral nerve regeneration.

Sinomenine Protects against Early Brain Injury by Inhibiting Microglial Inflammatory Response via Nrf2-Dependent Pathway after Subarachnoid Hemorrhage

Microglial activation and sustained inflammation plays an important role in the processes of early brain injury (EBI) after subarachnoid hemorrhage (SAH). Sinomenine (SIN) has been demonstrated to have neuroprotective effects in the traumatic brain injury (TBI) model. However, the role of SIN in SAH-induced EBI and its latent mechanisms remain unclear. This study was carried out to explore the role of SIN on SAH-induced EBI and its effects on the microglial inflammatory response following SAH. In this study, a model of SAH in rats was established. Modified neurological severity scores (mNSS), encephaledema, and Nissl staining were employed to determine the effects of SIN. Western blot and immunofluorescence analysis were performed to evaluate nuclear factor erythroid 2-related factor 2 (Nrf2) expression. Nrf2-related downstream proteins, including heme oxygenase-1 (HO-1) and quinine oxidoreductase-1 (NQO-1), were detected with immunohistochemistry analyses and Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR). Microglia activation and associated inflammatory factors, factor-kappa B (NF-κB), interleukin-1β (IL-1β), and interleukin-6 (IL-6), were assessed after SAH. The results showed that SIN administration improved neurobehavior function, and attenuated neural apoptosis and brain edema after SAH. In addition, SIN inhibited microglial action and the subsequent inflammatory response after SAH through the upregulated expression of HO-1 and NQO-1 via activation of the Nrf2 pathway. These results demonstrated that SIN supplementation provided protection against SAH-induced neuronal apoptosis by microglial inflammatory response regulation and possible involvement of the Nrf2 pathway.

Poor expression of miR-195-5p can assist the diagnosis of cerebral vasospasm after subarachnoid hemorrhage and predict adverse outcomes

OBJECTIVE

Patients with spontaneous subarachnoid hemorrhage (SAH) may develop refractory arterial cerebral vasospasm (CVS), which is the leading cause of death in SAH patients. This study explored the clinical diagnostic value of serum miR-195-5p levels in CVS after SAH (SAH + CVS) and its relationship with the prognosis of SAH + CVS.

METHODS

A total of 110 patients with spontaneous SAH were divided into the SAH group (N = 62) and SAH + CVS group (N = 58), with 60 healthy subjects as controls. The clinical data of blood glucose, blood sodium fluctuation, and serum lactic acid were recorded. miR-195-5p serum level was detected by RT-qPCR and its diagnostic value on SAH + CVS was analyzed by receiver operating characteristic curve. Serum levels of PDGF/IL-6/ET-1 and their correlation with miR-195-5p were analyzed using RT-qPCR, enzyme-linked immunosorbent assay, and Pearson's method. The patient prognosis was evaluated by Glasgow Outcome Scale. The effect of miR-195-5p levels on adverse prognosis was analyzed by Kaplan-Meier method and Cox regression analysis.

RESULTS

miR-195-5p was lowly expressed in the serum of SAH patients and lower in SAH + CVS patients. Serum miR-195-5p level assisted the diagnosis of SAH and SAH + CVS and was negatively correlated with PDGF/IL-6/ET-1 levels and was an independent risk factor together with ET-1 and blood glucose for SAH + CVS. miR-195-5p low expression predicted a higher cumulative incidence of adverse outcomes and was an independent predictor of adverse outcomes.

CONCLUSION

Poor expression of miR-195-5p can assist the diagnosis of SAH + CVS and predict higher adverse outcomes.

Noncoding RNA as Diagnostic and Prognostic Biomarkers in Cerebrovascular Disease

Noncoding RNAs (ncRNAs), such as microRNAs, long noncoding RNAs, and circular RNAs, play an important role in the pathophysiology of cerebrovascular diseases (CVDs). They are effectively detectable in body fluids, potentially suggesting new biomarkers for the early detection and prognosis of CVDs. In this review, the physiological functions of circulating ncRNAs and their potential role as diagnostic and prognostic markers in patients with cerebrovascular diseases are discussed, especially in acute ischemic stroke, subarachnoid hemorrhage, and moyamoya disease.