Mets-IR as a predictor of cardiovascular events in the middle-aged and elderly population and mediator role of blood lipids.

Background: Cardiovascular disease (CVD) is a global health concern, with a significant impact on morbidity and mortality rates. Using fasting glucose, fasting triglycerides, body mass index (BMI), and high-density lipoprotein cholesterol (HDL-C), the metabolic score of insulin resistance (Mets-IR), a novel index created by Mexican researchers to assess insulin sensitivity, is a more precise way to measure insulin sensitivity. This study aimes to explore the association between Mets-IR and CVD, as well as investigate the potential mediating role of of low-density lipoprotein cholesterol (LDL-C). Methods: The study's data came from the 2011 and 2018 China Health and Retirement Longitudinal Studies (CHARLS). We used three logistic regression models to account for the potential effects of ten factors on cardiovascular disease/stroke/heart disease. Moreover, We performed mediation analyses to evaluate the role of LDL-C in the association between Mets-IR and incident CVD. Results: This study comprised 4,540 participants, of whom 494 (10.88%) were found to develop disease (CVD). Each interquartile range (IQR) increased in Mets-IR raised the risk of developing CVD by 38% (OR=1.38; 95% CI, 1.21-1.56) and there was a linear dose-response relationship between Mets-IR and the risk of new-onset cardiovascular disease, stroke, and heart disease (P overall<0.05, P non-linear>0.05). Approximately 5% (indirect effect/total effect) of the significant association of Mets-IR with stroke was mediated by LDL-C, respectively. With the addition of Mets-IR to the base model, the continuous net reclassification improvement and integrated discrimination improvement for predicting cardiovascular disease increased by 0.175 (P <0.001) and 0.006 (P <0.001), respectively. Conclusion: ets-IR is associated with an increased risk of cardiovascular disease/stroke/cardiac issues, with LDL-C mediating these relationships. Improving insulin sensitivity and lipid regulation may be essential and effective preventive measures for cardiovascular events.

HIF­1α protects PC12 cells from OGD/R­induced cell injury by regulating autophagy flux through the miR­20a­5p/KIF5A axis.

Hypoxia inducible factor 1α (HIF­1α) has been reported to play a key role in protecting neurons from ischaemic injury. However, the exact molecular mechanisms remain largely unclear. PC12 cells were exposed to oxygen glucose deprivation/reoxygenation (OGD/R) conditions to mimic ischaemic injury in vitro. The expression of the HIF­1α mRNA, miR­20a­5p, and kinesin family member 5A (KIF5A) mRNA was tested using qRT-PCR. Levels of the HIF­1α, LC3I/II, P62, LAMP2, cathepsin B (CTSB) and KIF5A proteins were determined using western blotting. The CCK­8 assay was conducted to assess PC12 cell viability. DQ­Red­BSA and LysoSensor Green DND­189 dyes were employed to measure the proteolytic activity and pH of lysosomes, respectively. The interaction between miR­20a­5p and HIF­1α or KIF5A was verified by performing chromatin immunoprecipitation (ChIP) and/or dual­luciferase reporter assays. TUNEL staining was adopted to assess PC12 cell death. GFP­LC3 and RFP­GFP­LC3 probes were used to examine the autophagy status and autophagy flux of PC12 cells. A rat middle cerebral artery occlusion­reperfusion (MCAO/R) model was established to investigate the role of the HIF­1α/miR­20a­5p/KIF5A axis in ischaemic stroke in vivo. OGD/R exposure initiated PC12 cell autophagy and injury. HIF­1α expression was substantially increased in PC12 cells after OGD/R exposure. Overexpression of HIF­1α reversed the effects of OGD/R on reducing cell viability, blocking autophagy flux and inducing lysosome dysfunction. These rescue effects of HIF­1α depended on KIF5A. HIF­1α negatively regulated miR­20a­5p expression by targeting its promoter region, and miR­20a­5p directly targeted and negatively regulated the KIF5A mRNA. Overexpression of miR­20a­5p abolished the effects of HIF­1α on rescuing OGD/R­induced injury in PC12 cells. The effects of the HIF­1α/miR­20a­5p/KIF5A axis were verified in MCAO/R rats. HIF­1α protects PC12 cells from OGD/R­induced cell injury by regulating autophagy flux through the miR­20a­5p/KIF5A axis.

LncRNA nuclear-enriched abundant transcript 1 aggravates cerebral ischemia/reperfusion injury through activating early growth response-1/RNA binding motif protein 25 axis.

Ischemic stroke is a major global health issue. Ischemia and subsequent reperfusion results in stroke-related brain injury. Previous studies have demonstrated that nuclear-enriched abundant transcript 1 (NEATa and early growth response 1 (EGR1) are involved in ischemia reperfusion (IR) injury). In this study, we aimed to explore the roles of NEAT1/EGR1 axis as well as its downstream effector RNA binding motif protein 25 (RBM25) in cerebral IR injury. Oxygen-glucose deprivation/reperfusion (OGD/R) and middle cerebral artery occlusion (MCAO) were used to establish in vitro and in vivo models of cerebral IR injury, respectively. According to our data, NEAT1, EGR1, and RBM25 levels were elevated in OGD/R-exposed SK-N-SH and SH-SY5Y cells and cerebral cortex of MCAO mice. NEAT1, EGR1, or RBM25 knockdown effectively reduced infarct volumes and apoptosis, and improved neurological function. Mechanistically, NEAT1 directly interacted with EGR1, which restrained WW domain containing E3 ubiquitin protein ligase 1 (WWP1)-mediated ubiquitination of EGR1 and subsequently caused EGR1 accumulation. EGR1 bound to RBM25 promoter and transcriptionally activated RBM25. Rescue experiments indicated that RBM25 overexpression abolished the therapeutic effects of NEAT1 knockdown. In conclusion, this work identified a novel NEAT1/EGR1/RBM25 axis in potentiating brain injury after IR insults, suggesting a potential therapeutic target for ischemic stroke.

LncRNA RMRP accelerates autophagy-mediated neurons apoptosis through miR-3142/TRIB3 signaling axis in alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is a major neurodegenerative disorder. The functions of lncRNA RMRP have been characterized mainly in various human cancers. However, the functional network of RMRP in AD progression remains unknown. METHODS: Human serum samples, AD transgenic (Tg) mice as well as SH-SY5Y cells were used in this study. The RNA expression patterns of RMRP, miR-3142 and TRIB3 were assessed by quantitative real-time PCR (qRT-PCR). Levels of apoptosis- or autophagy-associated biomarkers and TRIB3 level were evaluated using immunohistochemistry (IHC), western blotting or immunofluorescence assays, respectively. Bioinformatics methods and luciferase assays were used to predict and validate the interactions among RMRP, miR-3142, and TRIB3. Flow cytometry, TUNEL staining and EdU assays were used to examine the apoptosis and proliferation of neurons, respectively. RESULTS: The elevated RMRP and TRIB3 expressions and activation of autophagy were observed in AD. Knockdown of RMRP restrained neuronal apoptosis and autophagy activation in vitro and in vivo. Interestingly, TRIB3 overexpression reversed the biological effects of RMRP silencing on Aß1-42-induced cell apoptosis and autophagy. Further mechanistic analysis showed RMRP acted as a sponge of miR-3142 to elevate TRIB3 level. CONCLUSION: These data illustrated that knockdown of RMRP inhibited autophagy and apoptosis via regulating miR-3142/TRIB3 axis in AD, suggesting that inhibition of RMRP maybe a therapeutic strategy for AD.

Matrix Metalloproteases-Mediated Cleavage on ß-Dystroglycan May Play a Key Role in the Blood-Brain Barrier After Intracerebral Hemorrhage in Rats.

BACKGROUND It is well documented that the Blood-Brain barrier (BBB) can be damaged by matrix metalloproteases (MMPs) after intracerebral hemorrhage (ICH), but little is known about the mechanism of this effect. MATERIAL AND METHODS We established an ICH model in rats by injecting collagenase VII into the striatum. Afterwards, intraperitoneal injection of these rats with 40 mg/kg GM6001 (a MMPs inhibitor). The effects of GM6001 on ICH were investigated by neurological severity score, brain water content, Evans blue staining, hematoxylin-eosin staining, immunohistochemical staining, and Western blot assays. RESULTS We demonstrated that the neurological damage caused by ICH was relieved at 5 and 7 days following administration of GM6001. The impaired BBB induced by ICH was improved in response to GM6001 treatment at around 3 days, as evidenced by alleviated cerebral edema, decreased Evans blue extravasation, and a reduction in inflammatory cellular infiltration. Mechanism analysis revealed that ICH induced the generation of ß-dystroglycan cleavage, which could be suppressed by GM6001 treatment. Furthermore, we found that recombinant MMP2 and MMP9 triggered the cleavage of ß-dystroglycan in vitro, and this action could be inhibited by GM6001 administration. CONCLUSIONS Taken together, our results suggest that MMPs-mediated cleavage on ß-dystroglycan may play an important role in BBB after ICH.