Sevoflurane exerts protection against myocardial ischemia-reperfusion injury and pyroptosis through the circular RNA PAN3/microRNA-29b-3p/stromal cell-derived factor 4 axis.

Sevoflurane is suggested to exert protective functions against myocardial ischemia-reperfusion injury (MIRI). However, the particular mechanism remains elusive. Therefore, this research explored the mechanism of sevoflurane in MIRI-induced damage and pyroptosis. Subsequent to gain-or loss-of-function assays or/and sevoflurane treatment, the MIRI model was developed in rats. Cardiac function and body and heart weight of rats were evaluated, followed by measurement of apoptosis and creatine kinase MB (CK-MB), lactate dehydrogenase (LDH), and pyroptosis-related protein levels. After loss-of-function assays or/and sevoflurane treatment in human cardiomyocytes (HCMs), the hypoxia/reoxygenation (H/R) model was constructed. In HCMs, cell viability, apoptosis, and pyroptosis-related proteins were detected. Circular RNA PAN3 (circPAN3), microRNA (miR)-29b-3p, and stromal cell-derived factor 4 (SDF4) expression was determined in rat myocardial tissues and HCMs. Mechanistically, interactions among circPAN3, miR-29b-3p, and SDF4 were analyzed. MIRI modeling increased miR-29b-3p expression and diminished circPAN3 and SDF4 expression in H/R-treated HCMs and MIRI rats, which was nullified by sevoflurane preconditioning. Mechanistically, circPAN3 negatively targeted miR-29b-3p to upregulate SDF4. Moreover, sevoflurane preconditioning reduced heart weight/body weight ratio, LDH, CK-MB, myocardial infarct size, left ventricular end-diastolic pressure, apoptosis, and pyroptosis, while elevating the increase and decrease of left ventricular pressure (±dp/dt max) and left ventricular systolic pressure in MIRI rats. In addition, sevoflurane preconditioning augmented viability while diminishing apoptosis and pyroptosis in H/R-treated HCMs. Moreover, circPAN3 silencing or miR-29b-3p overexpression abrogated alleviatory effects of sevoflurane on myocardial injury and pyroptosis in vitro. Sevoflurane treatment ameliorated myocardial injury and pyroptosis in MIRI via circPAN3/miR-29b-3p/SDF4 axis.

An L ，Zhong Y ，Tan J ，Liu Y ，Li A ，Yang T ，Wang S ，Liu Y ，Gao H ... -  《-》

Dexmedetomidine inhibits pyroptosis by down-regulating miR-29b in myocardial ischemia reperfusion injury in rats.

Dexmedetomidine (DEX) was reported to protect heart against ischemic-reperfusion (IR) but the mechanism herein remains elusive. This study aims to explore the mechanism of DEX on pyroptosis induced by myocardial ischemic reperfusion (MIR). MIR rat models were established and injected DEX or miR-29b agomir/antagomir separately. The possible effect of DEX or miR-29b on myocardial cells was assessed according to measurement on creatine kinase-MB (CK-MB), cardiac troponin I (cTnI), interleukin-1β (IL-1β) and interleukin-18 (IL-18), myocardial infarction size, myocardial injury and apoptosis. Western blot determined the expression levels of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), apoptosis-associated speck-like protein containing CARD (ASC) and cleaved-caspase-1. Hypoxia/reoxygenation (H/R) cell model was established. The lactate dehydrogenase (LDH) content released by myocardial cells was examined. The relation between miR-29b and FoxO3a was confirmed by dual luciferase reporter gene assay. FoxO3a or ARC level was elevated in H/R myocardial cells to detect its effect on pyroptosis. MIR rat models were successfully established, in which cell pyroptosis was triggered as evidenced by increased expression levels of NLRP3, ASC and cleaved-caspase-1. Rats with DEX precondition had attenuated cell pyroptosis and ameliorated inflammatory response. FoxO3a was a target of miR-29b. MiR-29b agomir or miR-29b antagomir could inhibit or promote the protective effect of DEX on MIR. Overexpression of FoxO3a/ARC axis could suppress myocardial pyroptosis induced by H/R. DEX could ameliorate MIR injury (MIRI) and H/R injury in rats and inhibit H/R induced pyroptosis in myocardial cells via down-regulating miR-29b to activate FoxO3a/ARC axis.

Zhong Y ，Li YP ，Yin YQ ，Hu BL ，Gao H ... -  《-》

The role of microRNA-1 targeting of MAPK3 in myocardial ischemia-reperfusion injury in rats undergoing sevoflurane preconditioning via the PI3K/Akt pathway.

Hao YL ，Fang HC ，Zhao HL ，Li XL ，Luo Y ，Wu BQ ，Fu MJ ，Liu W ，Liang JJ ，Chen XH ... -  《-》

The lncRNA ROR/miR-124-3p/TRAF6 axis regulated the ischaemia reperfusion injury-induced inflammatory response in human cardiac myocytes.

Liang YP ，Liu Q ，Xu GH ，Zhang J ，Chen Y ，Hua FZ ，Deng CQ ，Hu YH ... -  《-》

Suxiao Jiuxin Pill alleviates myocardial ischemia/reperfusion-induced autophagy via miR-193a-3p/ALKBH5 pathway.

Myocardial ischemia/reperfusion injury (MIRI) poses a formidable challenge to cardiac reperfusion therapy due to the absence of effective clinical interventions. Methylation of N6-methyladenosine (m6A), which is the most common post-transcriptional modifications occurring within mammalian mRNA, is believed to be involved in MIRI by modulating autophagy. MicroRNAs (miRNAs) play a crucial role in regulating gene expression at the post-transcriptional level and have been implicated in the regulation of m6A methylation. Suxiao Jiuxin Pill (SJP) is extensively used in China for the clinical treatment of angina pectoris and confers benefits to patients with acute coronary syndrome who have received percutaneous coronary intervention. However, the precise mechanisms underlying SJP intervention in MIRI remain unclear. This study aimed to demonstrate, both in vivo and in vitro, that SJP could alleviate autophagy in MIRI by regulating miR-193a-3p to target and upregulate the demethylase ALKBH5. An in vitro hypoxia/reoxygenation model was established using H9c2 cells, while an in vivo MIRI model was established using Wistar rats. A lentivirus harboring the precursor sequence of miR-193a-3p was employed for its overexpression. Adeno-associated viruses were used to silence both miR-193a-3p and ALKBH5 expressions. Cardiac function, infarct size, and tissue structure in rats were assessed using echocardiography, triphenyl tetrazolium chloride (TTC) staining, and HE staining, respectively. Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) was employed to detect the levels of apoptosis in rat cardiac tissue. m6A methylation levels were assessed using colorimetry. GFP-RFP-LC3B was used to monitor autophagic flux and transmission electron microscopy was used to evaluate the development of autophagosomes. Western Blot and qRT-PCR were respectively employed to assess the levels of autophagy-related proteins and miR-193a-3p. SJP alleviated autophagy, preserved cardiac function, and minimized myocardial damage in the hearts of MIRI rats. SJP attenuated autophagy in H/R H9C2 cells. Elevated levels of miR-193a-3p were observed in the cardiac tissues of MIRI rats and H/R H9C2 cells, whereas SJP downregulated miR-193a-3p levels in these models. ALKBH5, a target gene of miR-193, is negatively regulated by miR-193a-3p. Upon overexpression of miR-193a-3p or silencing of ALKBH5, m6A methylation decreased, and the autophagy-attenuating effects of SJP and its components, senkyunolide A and l-borneol, were lost in H/R H9C2 cells, whereas in MIRI rats, these effects were not abolished but merely weakened. Further investigation indicated that the METTL3 inhibitor STM2475, combined with the silencing of miR-193a-3p, similarly attenuated autophagy in the hearts of MIRI rats. This suggests that a reduction in m6A methylation is involved in autophagy alleviation. We demonstrated that SJP mitigates autophagy in MIRI by downregulating miR-193a-3p, enhancing ALKBH5 expression, and reducing m6A methylation, a mechanism potentially attributed to its constituents, senkyunolide A and l-borneol.

Wang D ，Wang D ，Jin Q ，Wang X ... -  《-》