The study aims to explore the effects of miR-135b-5p on
myocardial ischemia/reperfusion (I/R)
injuries by regulating Janus
protein tyrosine kinase 2 (JAK2)/signal transducer and activator of transcription (STAT) signaling pathway by mediating
inhalation anesthesia with
sevoflurane. A sum of 120 healthy Wistar male mice was assigned into six groups. Left ventricular ejection fraction (LVEF) and left ventricular shortening fraction (LVSF) were detected. Cardiomyocyte apoptosis was determined by terminal dexynucleotidyl
transferase mediated dUTP-
biotin nick end labeling (TUNEL) assay. MiR-135b-5p expression,
mRNA and
protein expression of p-STAT3, p-JAK2, STAT3, JAK2, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X
protein B (Bax) were detected by quantitative real-time PCR (qRT-PCR) and Western blotting. Target relationship between miR-135b-5p and JAK2 was confirmed by dual-
luciferase reporter assay. The other five groups exhibited increased cardiomyocyte
necrosis, apoptosis, miR-135b-5p and Bax expression,
mRNA expression of JAK2 and STAT3, and
protein expression of p-STAT3 and p-JAK2 compared with the
sham group, but showed decreased LVEF, LVFS, and Bcl-2 expression. Compared with the model and
AG490 + Sevo groups, the Sevo, inhibitor + Sevo and inhibitor +
AG490 + Sevo groups displayed reduced cardiomyocyte
necrosis, apoptosis, miR-135b-5p and Bax expression, but displayed elevated
mRNA expression of JAK2 and
STAT3, protein expression of p-STAT3 and p-JAK2, LVEF, LVFS and Bcl-2 expression. Compared with the Sevo and inhibitor +
AG490 + Sevo groups, the
AG490 + Sevo group showed decreased LVEF, LVFS, Bcl-2 expression,
mRNA expressions of JAK2 and STAT3, and
protein expressions of p-STAT3 and p-JAK2, but increased cardiomyocyte
necrosis, apoptosis, and Bax expressions. MiR-135b-5p negatively targetted JAK2. Inhibition of miR-135b-5p can protect against myocardial I/R injury by activating JAK2/STAT3 signaling pathway through mediation of
inhalation anesthesia with
sevoflurane.