Single-nucleus transcriptome unveils the role of ferroptosis in ischemic stroke.

Multiple cell death pathways are involved in neuronal death in ischemic stroke (IS). However, the role of different cell death pathways in different cell types has not been elucidated. By analyzing three single-nucleus RNA sequencing (snRNA-seq) data of IS, we first found that a variety of programmed cell death (PCD) -related genes were significantly changed in different cell types. Based on machine learning and virtual gene knockout, we found that ferroptosis related genes, ferritin heavy chain 1 (Fth1) and ferritin light chain (Ftl1), play a key role in IS. Ftl1 and Fth1 can promote microglia activation, as well as the production of inflammatory factors and chemokines. Cell communication analysis showed that activated microglia could enhance chemotactic peripheral leukocyte infiltration, such as macrophages and neutrophils, through Spp1-Cd44 and App-Cd74 signaling, thereby aggravating brain tissue damage. Furthermore, real-time quantitative polymerase chain reaction (RT-qPCR) showed that P2ry12 and Mef2c were significantly decreased in oxygen-glucose deprivation (OGD) group, while Ftl1, Fth1, Apoe, Ctsb, Cd44 and Cd74 were significantly increased in OGD group. Collectively, our findings suggested targeted therapy against microglia Ftl1 and Fth1 might improve the state of microglia, reduce the infiltration of peripheral immune cells and tissue inflammation, and then improve the ischemic brain injury in mouse.

Brain microvascular endothelial cell-derived exosomes transmitting circ_0000495 promote microglial M1-polarization and endothelial cell injury under hypoxia condition.

Human brain microvascular endothelial cells (HBMVECs) and microglia play critical roles in regulating cerebral homeostasis during ischemic stroke. However, the role of HBMVECs-derived exosomes in microglia polarization after stroke remains unknown. We isolated exosomes (Exos) from oxygen glucose deprivation (OGD)-exposed HBMVECs, before added them into microglia. Microglia polarization markers were tested using RT-qPCR or flow cytometry. Inflammatory cytokines were measured with ELISA. Endothelial cell damage was assessed by cell viability, apoptosis, apoptosis-related proteins, oxidative stress, and angiogenic activity using CCK-8, flow cytometry, western blot, ELISA, and endothelial tube formation assay, respectively. We also established middle cerebral artery occlusion (MCAO) mice model to examine the function of circ_0000495 on stroke in vivo. Our study found that HBMVECs-Exos reduced M2 markers (IL-10, CD163, and CD206), increased M1 markers (TNF-α, IL-1ß, and IL-12), CD86-positive cells, and inflammatory cytokines (TNF-α and IL-1ß), indicating the promotion of microglial M1-polarization. Microglial M1-polarization induced by HBMVECs-Exos reduced viability and promoted apoptosis and oxidative stress, revealing the aggravation of endothelial cell damage. However, circ_0000495 silencing inhibited HBMVECs-Exos-induced alterations. Mechanistically, circ_0000495 adsorbed miR-579-3p to upregulate toll-like receptor 4 (TLR4) in microglia; miR-579-3p suppressed HBMVECs-Exos-induced alterations via declining TLR4; furthermore, Yin Yang 1 (YY1) transcriptionally activated circ_0000495 in HBMVECs. Importantly, circ_0000495 aggravated ischemic brain injury in vivo via activating TLR4/nuclear factor-κB (NF-κB) pathway. Collectively, OGD-treated HBMVECs-Exos transmitted circ_0000495 to regulate miR-579-3p/TLR4/NF-κB axis in microglia, thereby facilitating microglial M1-polarization and endothelial cell damage.

Extracellular Vesicles from Neural Stem Cells Carry microRNA-16-5p to Reduce Corticosterone-induced Neuronal Injury in Depression Rats.

OBJECTIVE: Depression is a common mental illness. Neural stem cell-derived extracellular vesicles (NSC-EVs) are involved in repairing neuronal injury. We estimated the mechanism of miR-16-5p in depression rats. METHODS: EVs were extracted from NSCs. The depression rat model was established by corticosterone (CORT) induction and treated with NSC-EVs. The depression behavioral/pathological changes in rats were assessed using forced swimming test, open field test, sucrose consumption test and western blotting. The neuronal apoptosis in hippocampal tissue were detected. CORT-induced PC12 cell model was established. EV uptake by PC12 cells was measured and PC12 cell apoptosis was detected. The downstream targets of miR-16-5p were predicted and verified. The expressions of miR-16-5p and MYB in rats, PC12 cells, and EVs were measured. Functional rescue experiments were conducted to verify the role of miR-16-5p and MYB in PC12 cell apoptosis. RESULTS: CORT induction increased neuronal apoptosis in hippocampal tissue and induced depression-like behaviors in rats, while NSC-EV treatment improved depression-like behaviors and apoptosis in rats. In PC12 cells, NSC-EVs decreased CORT-induced PC12 cell apoptosis. NSC-EVs carried miR-16-5p into PC12 cells. miR-16-5p knockdown in EVs partially reversed the inhibitory effects of NSC-EVs on CORT-induced PC12 cell apoptosis. miR-16-5p targeted to inhibit MYB to repress CORT-induced PC12 cell apoptosis. In vivo experiments further verified that NSC-EVs reduced neuronal injury in CORT-induced depression rats via the miR-16-5p/MYB axis. CONCLUSION: NSC-EVs-mediated alleviation on neuronal injury by carrying miR-16-5p to target MYB was highly likely one of the mechanisms by which NSC-EVs mediated miR-16-5p in neuroprotection of depression rats.

Stress conditions induced circRNAs profile of extracellular vesicles in brain microvascular endothelial cells.

Cerebral ischemia causes hypoxic injury and inflammation, and brain microvascular endothelial cells (BMVECs) dysfunction is an initial stage of blood-brain barrier disruption. Endothelial cells secrete extracellular vesicles (EVs) that are involved in intercellular signal transduction. EVs contain a variety of RNAs, proteins, and metabolites. Circular RNA (circRNA) is a member of the non-coding RNA. The expression profile and potential function of circRNAs in BMVECs are unknown. Here, human BMVECs have undergone hypoxia or TNF-α induction, and the changes in circRNAs were measured by RNA sequencing. A total of 70 circRNAs showed differential expression, including 43 previously unrecorded circRNAs and 27 recorded circRNAs. Since astrocyte end-feet encircle endothelial cells, they are considered the main targets of the EVs from BMVEC. The miRNA sequence data and bioinformatics were used to predict the circRNA-miRNA-mRNA networks in astrocytes. The gene ontology (GO) analysis showed the main downstream targets of circRNAs are DNA transcription regulation and protein kinase-related signaling pathways. These results suggest that altering circRNAs may be a potential therapeutic target for cerebral ischemia induced hypoxic injury and inflammation.

Broad and dynamic neurochemical alterations in the brain of alcoholic rats.

Ethanol is the active ingredient in alcoholic beverages. As ethanol consumption increases from zero to very high, it is still unknown which metabolites are present at different times and which are essential to normal functioning. In this article, we used an intermittent-access 20% ethanol drinking paradigm to make Wistar male rats voluntarily drink large amounts of ethanol for 10, 20, 30, and 50 days, respectively. A hydrogen-1 nuclear magnetic resonance approach was used to investigate the time-dependent neurochemical metabolites spectra in the hippocampus, striatum, nucleus accumbens and prefrontal cortex. Multivariate pattern recognition techniques were used to analyze the hydrogen-1 nuclear magnetic resonance spectra data. Metabolic profiling was obtained, differentiating the ethanol-treated and control rats. The ethanol-affected metabolites disrupted processes associated with neurotransmitters, oxidative stress, energy metabolism and amino acids. Together, our findings demonstrate broad, dynamic, and time-dependent endogenous metabolic alterations in rats treated with ethanol.

miR-18b attenuates cerebral ischemia/reperfusion injury through regulation of ANXA3 and PI3K/Akt signaling pathway.

Recent, research has displayed that the disorders of miR-18b are related to ischemic stroke. Here, we aimed to investigate the underlying neuroprotective mechanism of miR-18b in cerebral ischemia/reperfusion (I/R) injury. Oxygen-glucose deprivation/reperfusion (OGDR) model in vitro and middle cerebral artery occlusion (MCAO) model in vivo were established to simulate cerebral I/R injury. RT-PCR, western blotting, CCK-8, TUNEL, and TTC staining assays were applied in this study to explore the effect of miR-18b on cerebral I/R injury. Results displayed that miR-18b expression was reduced after cerebral I/R injury. Besides, miR-18b showed neuroprotective effects on cerebral I/R injury both in vitro and in vivo, These neuroprotective effects included promoting cell viability, decreasing cell apoptosis, reducing the production of inflammatory cytokines in SH-SY 5Y cells after OGDR and depressing MCAO-induced infarct size, neurological deficits and apoptotic cells in mice. Moreover, miR-18b negatively regulated ANXA3 expression, and its neuroprotection on cerebral I/R injury was overturned by ANXA3. Additionally, increasing miR-18b or decreasing ANXA3 promoted the activation of the PI3K/Akt signaling pathway in SH-SY 5Y cells after cerebral I/R injury. In conclusion, these data indicate that miR-18b protects against cerebral I/R injury by inhibiting ANXA3 and activating PI3K/Akt pathway, which provides a promising therapeutic target for ischemic stroke therapy.

CircRNA_0001449 disturbs phosphatidylinositol homeostasis and AKT activity by enhancing Osbpl5 translation in transient cerebral ischemia.

Phosphatidylinositol-3,4,5-trisphosphate [PI(3,4,5)P3] is a phosphorylated derivative of phosphatidylinositol 4-phosphate [PI(4)P] and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2], which recruit and activate AKT in the plasma membrane (PM) to promote cellular survival. ORP5 anchors at the endoplasmic reticulum (ER)-PM contact sites and acts as a PI(4)P and PI(4,5)P2/phosphatidylserine (PS) exchanger. Here, a lipidomics analysis of the sensorimotor cortex revealed that transient middle cerebral artery occlusion (tMCAO) disturbs the homeostasis of phosphatidylinositols (PIs) and PS between the PM and ER. Conditional knockout mice showed that ORP5 contributes to this abnormal distribution. Abolishing the ORP5 gene significantly inhibited apoptosis and autophagy. RNA sequencing and RNA pull down analyses confirmed a competing endogenous RNA pathway in which circ_0001449 sponges miR-124-3p and miR-32-5p to promote Osbpl5 translation. Our data showed that circRNA_0001449 regulates membrane homeostasis via ORP5 and is involved in the AKT survival pathway.

Novel circular RNAs expressed in brain microvascular endothelial cells after oxygen-glucose deprivation/recovery.

Circular RNAs (circRNAs) are generated by head-to-tail splicing and are ubiquitously expressed in all multicellular organisms. Their important biological functions are increasingly recognized. Cerebral ischemia reperfusion injury-induced brain microvascular endothelial cell dysfunction is an initial stage of blood-brain barrier disruption. The expression profile and potential function of circRNAs in brain microvascular endothelial cells is unknown. Rat brain microvascular endothelial cells were extracted and cultured in glucose-free medium for 4 hours with 5% CO2 and 95% N2, and the medium was then replaced with complete growth medium for 6 hours. The RNA in these cells was then extracted. The circRNA was identified by Find_circ and CIRI2 software. Functional and pathway enrichment analysis of genes that were common to differentially expressed mRNAs and circRNA host genes was performed by the Database for Annotation, Visualization and Integrated Discovery Functional Annotation Tool. Miranda software was used to predict microRNAs that were potentially spong-ed by circRNAs. Furthermore, cytoscape depicted the circR-NA-microRNA interaction network. The results showed that there were 1288 circRNAs in normal and oxygen-glucose deprived/recovered primary brain microvascular endothelial cells. There are 211 upregulated and 326 downregulated differentially expressed circRNAs. The host genes of these differentially expressed circRNAs overlapped with those of differentially expressed mRNAs. The shared genes were further studied by functional enrichment analyses, which revealed that circRNAs may contribute to calcium ion function and the cyclic guanosine 3',5'-monophosphate (CAMP) dependent protein kinase (PKα) signaling pathway. Next, quantitative reverse transcription polymerase chain reaction assays were performed to detect circRNA levels transcribed from the overlapping host genes. Eight out of the ten circRNAs with the highest fold-change identified by sequencing were successfully verified. Subsequently, the circRNA-microRNA interaction networks of these eight circRNAs were explored by bioinformatic analysis. These results demonstrate that altered circRNAs may be important in the pathogenesis of cerebral ischemia reperfusion injury and consequently may also be potential therapeutic targets for cerebral ischemia diseases. All animal experiments were approved by the Chongqing Medical University Committee on Animal Research, China (approval No. CQMU20180086) on March 22, 2018.

Preparation and Application of Ornidazole Magnetic Imprinted Polymers with Dual Functional Monomers / 分析化学

The magnetic molecularly imprinted polymers ( MMIPs ) was synthesiZed by suspension polymers technique using ornidaZole ( ONZ) as template, and methacrylic acid ( MAA) and acrylamide ( AA) as the binary functional monomers.The MMIPs were characteriZed by means of scanning electron microscopy ( SEM ) , Fourier transform infrared spectroscopy ( FT-IR ) , vibrating sample magnetometer ( VSM ) , thermogravimetric analysis ( TGA) and ultraviolet-visible ( UV-Vis) spectrophotometer.The results indicated that the adsorption capacity of MMIPs using the binary functional monomers to ONZ was higher than that using single functional monomer or that of its structural analogues.The Scatchard plot revealed that the template polymer system had a two-site binding behavior and the MMIPs exhibited the maximum rebinding to ONZ at 48.96 μmol/g and 10.60 μmol/g.Combined with high performance liquid chromatographic analysis technology, the prepared MMIPs were successfully applied to extract and enrich trace nitroimidaZoles from river water samples with recoveries range of 85.4%-104.3%.The precision of the results was good, and the manipulation of the developed method was simple and fast comparing to other methods.

MicroRNAs: a novel promising therapeutic target for cerebral ischemia/reperfusion injury?

To determine the molecular mechanism of cerebral ischemia/reperfusion injury, we examined the microRNA (miRNA) expression profile in rat cortex after focal cerebral ischemia/reperfusion injury using miRNA microarrays and bioinformatic tools to systematically analyze Gene Ontology (GO) function classifications, as well as the signaling pathways of genes targeted by these differentially expressed miRNAs. Our results show significantly changed miRNA expression profiles in the reperfusion period after focal cerebral ischemia, with a total of 15 miRNAs up-regulated and 44 miRNAs down-regulated. Target genes of these differentially expressed miRNAs were mainly involved in metabolic and cellular processes, which were identified as hub nodes of a miRNA-GO-network. The most correlated pathways included D-glutamine and D-glutamate metabolism, the renin-angiotensin system, peroxisomes, the PPAR signaling pathway, SNARE interactions in vesicular transport, and the calcium signaling pathway. Our study suggests that miRNAs play an important role in the pathological process of cerebral ischemia/reperfusion injury. Understanding miRNA expression and function may shed light on the molecular mechanism of cerebral ischemia/reperfusion injury.

[Integrated treatment of traditional Chinese medicine and western medicine for early- and intermediate-stage diabetic nephropathy].

OBJECTIVE: To study the therapeutic effect of traditional Chinese herbal medicinal preparation Tangshenqing (TSQ) combined with alprostadil in the treatment of early- and intermediate-stage diabetic nephropathy (DN). METHODS: One hundred and twenty DN patients were randomized into 3 groups for different treatment protocols. The patients in the control group were given the basic treatment (low-protein diabetic diet and rigorous control of blood glucose, blood pressure, and blood fatty acid), and those in treatment group A received TSQ (containing Astragalus membranaceus, Panax notoginseng, Epimedium brevicornum, etc) in addition to the basic treatment, and those in treatment group B were treated with alprostadil injections (for 14 consecutive days) in addition to the treatment given in group A. Therapeutic effect evaluation was carried out after a 30-day treatment in all the patients. RESULTS: The overall efficaey rate of the treatment was 78.37% in the control group, 88.57% in the treatment group A, and 94.44% in treatment group B, suggesting better therapeutic effect in the latter two groups than in the control group (P<0.05). Patients in all the 3 groups exhibited symptomatic improvement of various degrees, but the treatment group B had the best results. After the treatments, the patients' blood glucose and fatty acids were lowered, without obvious difference between the 3 groups. Compared with the control group, the patients in the two treatment groups showed significant reduction in fibrinogen, 24-h urine microprotein and urine protein after the treatment (P<0.01 or 0.05). CONCLUSION: Combined use of traditional Chinese herbal medicine TSQ and alprostadil injections produces definite therapeutic effect on early- to intermediate-stage DN.