Adiponectin-Transfected Endothelial Progenitor Cells Have Protective Effects After 2-Hour Middle-Cerebral Artery Occlusion in Rats With Type 2 Diabetes Mellitus

Advanced Glycation End-Products (AGEs) Promote Endothelial Cell Pyroptosis Under Cerebral Ischemia and Hypoxia via HIF-1α-RAGE-NLRP3

This work mainly aimed to explore the role and mechanism of advanced glycation end-products (AGEs) in inducing cerebrovascular endothelial cell pyroptosis under oxygen glucose deprivation (OGD) condition. The mouse cerebral microvascular endothelial cells (BMECs and bEnd.3) were used as the objects to construct the OGD model in vitro. Then, cells were pretreated with AGE-modified human serum albumin (AGE-HSA). Thereafter, CCK-8 assay was conducted to detect cell viability, and flow cytometry (FCM) was performed to measure cell pyroptosis level. Meanwhile, the expression of inflammatory factors was detected by enzyme-linked immunosorbent assay (ELISA). The expression of HIF-α, NLRP3, and RAGE was detected by fluorescence staining. The opening status of cell membrane pore was observed under the electron microscope, and the expression levels of FL-GSDMD, NT-GSDMD, and caspase-1 were measured through Western Blot (WB) assay. Moreover, bEnd.3 cells were treated with siRAN-silenced NLRP3 and HIF-α inhibitor, so as to observe the effect of AGEs on cell pyroptosis level. In the mouse model, the middle cerebral artery occlusion (MCAO) model was constructed by the suture-occluded method. After intraperitoneal injection of AGEs, the pathological changes in mouse brain tissues were detected; the expression levels of NLRP3, ZO-1, and CD31 were determined by histochemical staining, and the levels of inflammatory factors and pyroptosis-related proteins were also detected. Under OGD condition, AGEs induced the pyroptosis of bEnd.3 cells, and the cell pyroptosis rate increased, higher than that of the OGD group. Meanwhile, the levels of inflammatory factors were up-regulated; the expression of HIF-α, NLRP3, and RAGE in cells increased; and the levels of NT-GSDMD and caspase-1 were markedly higher than those of the control and OGD groups. siRNA-NLRP3 or HIF-α inhibitor treatment suppressed pyroptosis and reduced the inflammatory factor levels. In mouse experiments, AGE injection aggravated brain injury in the MCAO mouse model, decreased the expression of ZO-1 and CD31, and elevated the levels of NLRP3 and inflammatory factors. Under cerebral ischemia condition, AGEs can induce endothelial cell pyroptosis via HIF-α-RAGE-NLRP3, thereby further aggravating brain injury.

Unraveling the potential of endothelial progenitor cells as a treatment following ischemic stroke

Ischemic stroke is becoming one of the most common causes of death and disability in developed countries. Since current therapeutic options are quite limited, focused on acute reperfusion therapies that are hampered by a very narrow therapeutic time window, it is essential to discover novel treatments that not only stop the progression of the ischemic cascade during the acute phase, but also improve the recovery of stroke patients during the sub-acute or chronic phase. In this regard, several studies have shown that endothelial progenitor cells (EPCs) can repair damaged vessels as well as generate new ones following cerebrovascular damage. EPCs are circulating cells with characteristics of both endothelial cells and adult stem cells presenting the ability to differentiate into mature endothelial cells and self-renew, respectively. Moreover, EPCs have the advantage of being already present in healthy conditions as circulating cells that participate in the maintenance of the endothelium in a direct and paracrine way. In this scenario, EPCs appear as a promising target to tackle stroke by self-promoting re-endothelization, angiogenesis and vasculogenesis. Based on clinical data showing a better neurological and functional outcome in ischemic stroke patients with higher levels of circulating EPCs, novel and promising therapeutic approaches would be pharmacological treatment promoting EPCs-generation as well as EPCs-based therapies. Here, we will review the latest advances in preclinical as well as clinical research on EPCs application following stroke, not only as a single treatment but also in combination with new therapeutic approaches.

Associations of Abdominal Visceral Fat Content and Plasma Adiponectin Level With Intracranial Atherosclerotic Stenosis: A Cross-Sectional Study

Background

Abdominal obesity and adipocytokines are closely related to atherosclerosis, and adiponectin level is considered one of the important clinical indicators. This study aimed to analyze the associations of abdominal visceral fat content and adiponectin level with intracranial atherosclerotic stenosis (ICAS).

Methods

A total of 186 patients were enrolled in this study. Patients were distributed into ICAS and non-ICAS by the degree of artery stenosis. Plasma adiponectin levels and the ratio of visceral adipose tissue (VAT) to subcutaneous adipose tissue (SAT) were measured. The related factors of intracranial atherosclerotic stenosis were determined using multivariable logistic regression analysis.

Results

The VAT/SAT ratio (OR, 26.08; 95% CI, 5.92–114.83; p < 0.001) and adiponectin (OR, 0.61; 95% CI, 0.44–0.84; p = 0.002) were found to be the independent predictors of ICAS in a multivariable logistic regression analysis. The prevalence of ICAS increased (T1: 27.4%; T2: 50.0%; T3: 75.8%) as the VAT/SAT ratio tertile increased (p < 0.001). The prevalence of ICAS decreased (T1: 72.6%; T2: 54.8%; T3: 25.8%) as the adiponectin tertile increased (p < 0.001). In ROC curves analysis, VAT/SAT ratio had a sensible accuracy for the prediction of ICAS. The optimal cut-off value of VAT/SAT ratio to predict ICAS in this study was 1.04 (AUC: 0.747; p < 0.001; sensitivity: 67.4%; specificity: 74.7%). The optimal adiponectin cutoff was 3.03 ug/ml (AUC: 0.716; p < 0.001; sensitivity:75.8%; specificity: 61.5%).

Conclusion

Higher VAT/SAT ratio and lower plasma adiponectin levels were closely related to the increased risk of intracranial atherosclerotic stenosis.

Human amniotic fluid stem cells can improve cerebral vascular remodelling and neurological function after focal cerebral ischaemia in diabetic rats

Diabetes causes vascular injury and carries a high risk of ischaemic stroke. Human amniotic fluid stem cells (hAFSCs) can enhance cerebral vascular remodelling and have the potential to improve neurological function after stroke in diabetic rats. Five groups of female rats were examined: (1) normal control, (2) type 1 diabetic (T1DM) rats induced by streptozotocin injection (DM), (3) non‐DM rats receiving 60‐minute middle cerebral artery occlusion (MCAO), (4) T1DM rats receiving 60‐minute MCAO (DM + MCAO) and (5) T1DM rats receiving 60‐minute MCAO and injection with 5 × 10⁶ hAFSCs at 3 h after MCAO (DM + MCAO + hAFSCs). Neurological function was examined before, and at 1, 7, 14, 21 and 28 days, and cerebral infarction volume and haemorrhage, cerebral vascular density, angiogenesis and inflammatory were examined at 7 and 28 days after MCAO. hAFSCs treatment caused a significant improvement of neurological dysfunction, infarction volume, blood‐brain barrier leakage, cerebral arterial density, vascular density and angiogenesis and a reduction of brain haemorrhage and inflammation compared with non‐treatment. Our results showed that the effect of hAFSCs treatment against focal cerebral ischaemia may act through the recovery of vascular remodelling and angiogenesis and the reduction of inflammation in ischaemic brain.