MicroRNA-30b protects myocardial cell function in patients with acute myocardial ischemia by targeting plasminogen activator inhibitor-1

Relationships of Telomere Homeostasis with Oxidative Stress and Cardiac Dysfunction in Human Ischaemic Hearts

Although the roles of telomeres and oxidative stress in ischaemic cardiomyopathy (ICM) are known, mechanisms of telomere homeostasis and their relationship with oxidative stress are incompletely understood. We performed two RNA-seq analyses (mRNA n = 23; ncRNA n = 30) and protein validation on left ventricles of explanted hearts from ICM and control subjects. We observed dysregulation of the shelterin and cohesin complexes, which was related to an increase in the response to cellular oxidative stress. Moreover, we found alterations at mRNA level in the mechanisms of telomeric DNA repair. Specifically, increased RAD51D mRNA levels were correlated with left ventricular diameters. RAD51D protein levels were unaltered, however, and were inversely corelated with the miR-103a-3p upregulation. We also observed the overexpression of lncRNAs (TERRA and GUARDIN) involved in telomere protection in response to stress and alterations in their regulatory molecules. Expression of the TERRA transcription factor ATF7 was correlated with superoxide dismutase 1 expression and left ventricular diameters. The levels of GUARDIN and its transcription factor FOSL2 were correlated with those of catalase. Therefore, we showed specific alterations in the mechanisms of telomeric DNA repair and protection, and these alterations are related to an increase in the response mechanisms to oxidative stress and cardiac dysfunction in ICM.

Roles and regulatory mechanisms of miR-30b in cancer, cardiovascular disease, and metabolic disorders (Review)

MicroRNAs (miRNAs) are non-coding RNAs 21-23 nucleotides in length that regulate gene expression, and thereby modulate signaling pathways and protein synthesis in both physiological and pathogenic processes. miR-30b inhibits cell proliferation, migration, invasion and epithelial-mesenchymal transformation in multiple types of cancer. In addition to its role in several types of neoplasias, miR-30b has been shown to exhibit essential roles in cardiovascular and metabolic diseases. In the present review, an overview of the biological functions of miR-30b and its role in the pathogenesis of neoplastic, cardiovascular and metabolic diseases is provided. miR-30b is a potential candidate for clinical development as a diagnostic and prognostic biomarker, therapeutic agent and drug target. However, further research is required to elucidate its role in health and disease and to harness its potential clinical utility.

miR-30b facilitates preeclampsia through targeting MXRA5 to inhibit the viability, invasion and apoptosis of placental trophoblast cells

Preeclampsia (PE) may induce gestational failure threatening a significant number of pregnant women. Dysfunctional placental trophoblast cells have an important impact on PE progression. microRNAs (miRNAs) have been reported to participate in PE progression, whereas the mechanism that underlies miR-30b involved in PE progression and function of placental trophoblast cells remains poorly understood. Cell viability was investigated by cell counting kit-8 (CCK-8) assay. Cell apoptosis was detected by flow cytometry using Annexin V-FITC/propidium iodide (PI) staining. Cell invasion was analyzed by trans-well assay. The expression of miR-30b was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The abundance of matrix-remodeling associated 5 (MXRA5) protein was detected by western blots (WB). The interaction between miR-30b and MXRA5 was investigated by bioinformatics analysis and luciferase activity assay. The effect of miR-30b and MXRA5 on mitogen-activated protein kinases (MAPK) pathway and invasion was evaluated by WB. Then we found miR-30b was highly expressed in PE and its overexpression inhibited cell viability and invasion while enhanced apoptosis in JEG-3 and HTR8/SVneo cells. Moreover, MXRA5 was targeted by miR-30b and MXRA5 restoration attenuated the effect of miR-30b on cell processes in HTR8/SVneo cells. Besides, both of miR-30b and MXRA5 were associated with MAPK pathway in HTR8/SVneo cells. Our data suggested miR-30b might contribute to PE through inhibiting cell viability, invasion while inducing apoptosis of placental trophoblast cells via MAPK pathway by targeting MXRA5. These indicated that miR-30b might be a novel biomarker for PE treatment.

Tetramethylpyrazine exerts a protective effect against injury from acute myocardial ischemia by regulating the PI3K/Akt/GSK-3β signaling pathway

Objective

We investigated the protective effect of tetramethylpyrazine (TMP) on injury related to acute myocardial ischemia (AMI) induced by isoproterenol (ISO).

Materials and methods

Rats were randomly assigned to five groups: control, ISO, ISO + propranolol (10 mg/kg), ISO + TMP (10 mg/kg) and ISO + TMP (20 mg/kg). The rats in the three ISO + groups were pretreated with propranolol or TMP, while the rats in the control and ISO groups were pretreated with an equal volume of saline. Afterwards, the rats in the four administration groups were subcutaneously injected with ISO for two consecutive days. The levels of creatine kinase (CK), lactate dehydrogenase (LDH), superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-1β in the serum were measured using ELISA. The expressions of B-cell lymphoma-associated X-2 (Bax-2), B-cell lymphoma-2 (Bcl-2), phosphoinositide-3-kinase (PI3K), protein kinase B (Akt), glycogen synthase kinase 3β (GSK-3β), MDA5 and SOD1 were determined using western blotting assay. The phosphorylation of PI3K, Akt and GSK-3β were also determined using western blotting assay. The left ventricles of the rats were extracted and stained using hematoxylin and eosin (H&E). The ST segment was recorded using electrocardiograms (ECGs).

Results

Administration of TMP (10, 20 mg/kg) reduced the levels of MDA and CK and the activities of SOD and LDH in the serum. Pretreatment with TMP significantly reduced the levels of pro-inflammatory cytokines, including IL-1β, IL-6 and TNF-α. Treatment with TMP also improved the histopathological alteration and decreased the ST elevation. Furthermore, TMP ameliorated the expressions of Cu, SOD1, MDA5, Bax-2, Bcl-2, p-PI3K, p-Akt and p-GSK-3β in ISO-induced rats.

Conclusions

Tetramethylpyrazine protected against injury due to AMI by regulating the PI3K/Akt /GSK-3β signaling pathway.