Current neurovascular research最新文献

Background: Smad ubiquitination regulatory factor 2 (Smurf2) has been observed to alleviate ischemia-reperfusion injury. This study sought to explore the molecular mechanism of Smurf2-mediated forkhead box O4 (FOXO4) ubiquitination in oxygen-glucose deprivation/ reperfusion (OGD/R)-induced pyroptosis of cortical neurons.

Methods: Human cortical neurons (HCN-2) were subjected to OGD/R to establish a cell model of cerebral stroke. Smurf2, FOXO4, and doublecortin domain containing 2 (DCDC2) expressions were determined by RT-qPCR and Western blot. LDH release, pyroptosis-related proteins NLRP3, GSDMD-N, and cleaved-caspase-3, as well as inflammatory factors IL-1β and IL-18, were assessed by LDH assay kit, Western blot, and ELISA. The ubiquitination level of FOXO4 was determined by ubiquitination assay. The bindings of Smurf2 to FOXO4 and FOXO4 to DCDC2 were testified by Co-IP, ChIP, and dual-luciferase assays. Rescue experiments were designed to validate the role of FOXO4/DCDC2 in the pyroptosis of HCN-2 cells.

Results: Smurf2 was weakly expressed, while FOXO4 and DCDC2 were prominently expressed in OGD/R-treated HCN-2 cells. Smurf2 overexpression promoted LDH release, reduced NLRP3, GSDMD-N, and cleaved-caspase-3 proteins, and decreased IL-1β and IL-18 concentrations. Sumrf2 improved the ubiquitination level of FOXO4 to downregulate its protein level. FOXO4 is bound to the DCDC2 promoter to facilitate its transcription. Overexpression of FOXO4 or DCDC2 reversed the inhibition of Smurf2 overexpression on pyroptosis of OGD/Rtreated HCN-2 cells.

Conclusion: Smurf2 overexpression facilitated the ubiquitination of FOXO4 to reduce its protein level, thereby suppressing DCDC2 transcription and restricting OGD/R-induced pyroptosis of cortical neurons.

Background and purpose: The role of intravenous thrombolysis in patients with acute mild ischemic stroke remains highly controversial. Therefore, this study aims to analyze the efficacy and safety of intravenous thrombolysis in patients with mild ischemic stroke based on admission National Institutes of Health Stroke Scale (NIHSS) score.

Methods: The present study enrolled 507 patients with acute mild ischemic stroke admitted within 4.5 hours of symptom onset with an admission NIHSS score of 0 to 5. Patients were assigned to two groups based on admission NIHSS scores of 0 to 2 and 3 to 5, and subsequent analyses compared functional outcomes between thrombotic and non-thrombotic patients within these groups. The primary outcome was a modified Rankin score (mRS) of 0 or 1 at 90 days, representing functional independence. The safety outcomes were symptomatic intracranial hemorrhage (sICH), early neurological deterioration (END), and the rate of stroke recurrence within 90 days.

Results: Among the 267 patients with NIHSS scores of 0 to 2, 112 (41.9%) patients received intravenous thrombolysis. Overall, thrombolysis administration did not significantly improve the patient's functional prognoses at 90 days (adjusted OR=1.046, 95%CI=0.587-1.863, p = 0.878). However, there was a marked increase in the risk of sICH (p = 0.030). Of the 240 patients with NIHSS scores of 3 to 5, 155 (64.6%) patients received intravenous thrombolysis, resulting in a significant improvement in 90-day functional prognosis (adjusted OR=3.284, 95%CI=1.876- 5.749, p < 0.001) compared to those that did not receive thrombolysis intervention. Importantly, there was no significant increase in sICH incidence (adjusted OR=2.770, 95%CI=0.313-24.51, p = 0.360). There were no statistically significant differences in END or the rate of stroke recurrence within 90 days between thrombotic and non-thrombotic groups.

Conclusions: Intravenous thrombolysis is safe and effective in patients with baseline NIHSS scores of 3 to 5. In contrast, it did not improve 90-day functional outcomes in patients with NIHSS scores of 0 to 2 and instead increased the risk of sICH.

Background: The AKT/mTOR/p70S6K pathway has been shown to potentially promote spinal cord injury (SCI) repair in rats. However, its exact mechanism and beyond needs to be further explored.

Objective: This study aims to explore the AKT/mTOR/p70S6K pathway in oligodendrocyte precursor cell (OPC) differentiation, microglial polarization differentiation, and the role of these in myelin regeneration in vitro.

Methods: The isolation, induction and characterization of rat primary neuronal stem cells, OPCs and oligodendrocytes were investigated with immunofluorescence and RT-qPCR. Then, the role of AKT/mTOR/p70S6K signaling was explored using western blotting and immunofluorescence, the effect on myelination was examined with OPC-dorsal root ganglion (DRG) neurons co-culture, and the influence of M1/M2 polarization status of microglia on myelin formation was also observed by adding M1/M2 supernatants into OPC-DRG neurons co-culture.

Results: Activation of the AKT/mTOR/p70S6K pathway elevated the expression of oligodendrocyte differentiation markers, including MBP, PLP and MOG, which also promoted the colocalization of MBP and NFH in OPC-DRG neurons co-culture. More interestingly, stimulation of the AKT/mTOR/p70S6K pathway facilitated M2 polarization of rat microglia. M2 polarization of microglia enhanced OPC differentiation to oligodendrocytes and myelin formation.

Conclusion: Our findings highlight the potential of targeting the AKT/mTOR/p70S6K pathway in promoting oligodendrocyte differentiation and myelin regeneration in neurological disorders such as SCI.

Background: Stroke is a serious disease that threatens human health both in China and worldwide. Identifying and establishing its risk factors are prerequisites for intervention and evaluation of prognosis. Over the years, risk factors, such as age, diabetes, and hypertension, have gradually been established. However, at present, there is no consensus on the influence of sex on the prognosis of ischaemic stroke.

Aims: The aims of our research was to analyse the correlation between sex and poststroke prognosis based on the results of the Third China National Stroke Registry [CNSR-III], as well as the influence of other risk factors that may be confounded by sex on ischaemic stroke and potential interventions.

Methods: The CNSR-III recruited 14146 acute ischaemic stroke [AIS] patients between 2015 and 2018. Our study included 13,972 patients who had complete follow-up information. This research analysed basic information, socioeconomic status, lifestyle habits, medical history, and poststroke prognosis.

Results: There was a conspicuous relationship between sex and functional prognosis, stroke recurrence and all-cause death due to ischemic stroke in univariate analysis. Male stroke patients had a better prognosis than female patients. In multivariate analysis, we found that age, atrial fibrillation [AF], diabetes, hypertension and the severity of stroke had adverse effects on ischemic stroke prognosis. After adjustment for other risk factors, the functional prognosis of female patients at 3 months was worse than that of male patients [odds ratio [OR] 1.16, 95% confidence interval [CI], 1.025- 1.314]. Sex had a nonsignificant association with stroke recurrence at 3 months [hazard ratio [HR] 1.141, 95% CI, 0.975-1.336]. Furthermore, compared to male patients, female stroke patients had a lower cumulative death rate at 12 months [HR 0.777, 95% CI, 0.628-0.963].

Conclusion: Our study identified sex differences in stroke-related disability, recurrence, and death and attempted to explain the causes of these differences. Our study clearly showed that a large proportion of this difference could be attributed to age, socioeconomic factors, lifestyle habits, and medical history, confounded by sex differences rather than sex per se.

Periprosthetic osteolysis induced by wear particles can lead to aseptic loosening, one main reason of arthroplasty failure. However, the role of microRNA-130b (miR-130b) in particle-induced osteolysis (PIO) has not been explored yet. In this study, PIO models were established in C57BL/J6 mice via the implantation of Co-Cr-Mo alloy particles, and evaluated by detecting tartrate-resistant acid phosphatase (TRAP) activity and bone resorption in the calvaria. Mouse preosteoblast MC3T3-E1 cells were cultured to receive particle stimulation in vitro. Real time PCR and western blotting were performed to determine the expression levels of miR-130b and frizzled-related protein (FRZB), one potential target of miR-130b. Results showed upregulated miR-130b and downregulated FRZB in both PIO mice with remarkable osteolysis and particle-treated MC3T3-E1 cells showing inhibited proliferation and differentiation assayed by bromodeoxy urodine (BrdU) incorporation and alkaline phosphatase (ALP) activity respectively. Functional studies were conducted by transfection of miR-130b inhibitor in vitro or the injections of miR-130b inhibitor or small interfering RNA (siRNA) targeting FRZB in vivo. Interestingly, particle-induced inhibition on cell proliferation, differentiation and FRZB expression were all reversed by miR-130b silence. Luciferase report assays demonstrated that miR-130b indeed negatively regulated FRZB expression by targeting, while FRZB could reverse the opposed effect of miR-130b silence on PIO development. Therefore, the upregulated miR-130b in PIO models could act as one key regulator of PIO development, partly due to its negative regulation on FRZB.