LncRNA GAS5/miR-137 Is a Hypoxia-Responsive Axis Involved in Cardiac Arrest and Cardiopulmonary Cerebral Resuscitation.

Background: Cardiac arrest/cardiopulmonary resuscitation (CA/CPR) represents one of the devastating medical emergencies and is associated with high mortality and neuro-disability. Post-cardiac arrest syndrome (PCAS) is mechanistically ascribed to acute systemic ischemia/reperfusion(I/R) injury. The lncRNA/microRNA/mRNA networks have been found to play crucial roles in the pathogenesis of the hypoxia-responsive diseases. Nonetheless, the precise molecular mechanisms by which lncRNA/miRNA/mRNA axes are involved in the astrocyte-microglia crosstalk in CA/CPR have not been fully elucidated. Methods: We collected and purified the exosomes from the blood of CA/CPR patients and supernatant of OGD/R-stimulated astrocytes. On the basis of microarray analysis, bioinformatic study, and luciferase activity determination, we speculated that lncRNA GAS5/miR-137 is implicated in the astrocyte-microglia crosstalk under the insult of systemic I/R injury. The regulation of lncRNA GAS5/miR-137 on INPP4B was examined by cellular transfection in OGD/R cell culture and by lateral ventricle injection with miR-137 agomir in CA/CPR mice model. Flow cytometry and immunofluorescence staining were performed to detect the microglial apoptosis, M1/M2 phenotype transformation, and neuroinflammation. Neurological scoring and behavior tests were conducted in CA/CPR group, with miR-137 agomir lateral-ventricle infusion and in their controls. Results: In all the micRNAs, miR-137 was among the top 10 micRNAs that experienced greatest changes, in both the blood of CA/CPR patients and supernatant of OGD/R-stimulated astrocytes. Bioinformatic analysis revealed that miR-137 was sponged by lncRNA GAS5, targeting INPP4B, and the result was confirmed by Luciferase activity assay. qRT-PCR and Western blotting showed that lncRNA GAS5 and INPP4B were over-expressed whereas miR-137 was downregulated in the blood of CA/CPR patients, OGD/R-stimulated astrocytes, and brain tissue of CA/CPR mice. Silencing lncRNA GAS5 suppressed INPP4B expression, but over-expression of miR-137 negatively modulated its expression. Western blotting exhibited that PI3K and Akt phosphorylation was increased when lncRNA GAS5 was silenced or miR-137 was over-expressed. However, PI3K and Akt phosphorylation was notably suppressed in the absence of miR-137, almost reversing their phosphorylation in the silencing lncRNA GAS5 group. Then we found that GAS5 siRNA or miR-137 mimic significantly increased cell viability and alleviated apoptosis after OGD/R injury. Furthermore, over-expression of miR-137 attenuated microglial apoptosis and neuroinflammation in CA/CPR mice model, exhibiting significantly better behavioral tests after CA/CPR. Conclusion: LncRNA GAS5/miR-137 may be involved in the astrocyte-microglia communication that inhibits PI3K/Akt signaling activation via regulation of INPP4B during CA/CPR.

Clinical study of soluble thrombomodulin and urinary neutrophil gelatinase-associated lipocalin in early prediction of sepsis-induced acute kidney injury / 中华急诊医学杂志

Objective:To compare the early diagnostic value of the indicators of endothelial injury, renal injury, inflammation and coagulation in patients with sepsis-induced acute kidney injury (AKI).Methods:A retrospective study was performed on 119 patients with sepsis from February 2017 to March 2018. Lab tests were performed on patients at admission, which included:ing soluble thrombomodulin (sTM), tissue plasminogen activators and inhibitors (t-PAI-C), antithrombin III (AT-III), thrombin-antithrombin (TAT) complex, plasmin-alpha 2, plasmin inhibitor complex (PIC), fibrin degradation product (FDP), fibrinogen (FIB), D-Dimer, prothrombin time (PT), prothrombin time international normalized ratio (PT-INR), procalcitoni (PCT), white blood cell (WBC), neutrophil (Neu), and platelet count (PLT). The receiver-operating characteristic curve was used to analyze the predictive value of the above indicators, and logistic regression analysis was used to analyze the risk factors of sepsis-induced AKI. A prospective study was conducted from April 2018 to September 2018 and 46 patients were enrolled. The lab tests results retrieved including sTM, t-PAI-C, FDP, AT-III, TAT, PIC, FIB, D-Dimer, PT, PCT, serum cystatin C (Cys C), urine albumin (microalbumin) and albumin to creatinine ratio (ACR), urinary neutrophil gelatinase-associated lipocalin (uNGAL), urinary N-acetyl-beta-glucosaminidase (uNAG), and urinary retinol-binding protein (uRBP). As same with the previous group, the receiver-operating characteristic curve was used to analyze the diagnostic value of the above indicators, and logistic regression Was used to analyze the risk factors of sepsis-induced AKI.Results:(1) In the retrospective study: sTM, D-Dimer, PCT, PT, and PT-INR were statistically different. sTM, D-Dimer, PCT, PT, and PT-INR had a good diagnostic value for septis-induced AKI, among which, sTM had a highest diagnostic value (AUC: 0.857; 95% CI: 0.790, 0.924), better sensitivity (64.4%) and specificity (91.8%). The high expression of sTM and history of chronic kidney disease were independent risk factors for septis-induced AKI.(2) In the prospective study: PCT, sTM , Cys C, and uNGAL were statistically different. PCT, sTM, Cys C, uNGAL showed good predictive features for septis-induced AKI. sTM had the highest sensitivity (>0.999) while uNGAL had the highest specificity (0.800). The high expression of sTM was an independent risk factor for septis-induced AKI. Conclusions:sTM and uNGAL represent endothelial injury and renal tubular injury respectively. sTM is an independent risk factor of sepsis-induced AKI.