Anti-Apoptotic Effect of Apelin in Human Placenta: Studies on BeWo Cells and Villous Explants from Third-Trimester Human Pregnancy

Previously, we demonstrated the expression of apelin and G-protein-coupled receptor APJ in human placenta cell lines as well as its direct action on placenta cell proliferation and endocrinology. The objective of this study was to examine the effect of apelin on placenta apoptosis in BeWo cells and villous explants from the human third trimester of pregnancy. The BeWo cells and villous explants were incubated with apelin (2 and 20 ng/mL) alone or with staurosporine for 24 to 72 h. First, we analysed the dose- and time-dependent effect of apelin on the expression of apoptotic factors on the mRNA level by real-time PCR and on the protein level using Western blot. Next, we checked caspase 3 and 7 activity by Caspase-Glo 3/7, DNA fragmentation by the Cell Death Detection ELISA kit and oxygen consumption by the MitoXpress-Xtra Oxygen Consumption assay. We found that apelin increased the expression of pro-survival and decreased proapoptotic factors on mRNA and protein levels in both BeWo cells and villous explants. Additionally, apelin inhibited caspase 3 and 7 activity and DNA fragmentation in staurosporine-induced apoptosis as also attenuated oxidative stress by increasing extracellular oxygen consumption. The antiapoptotic effect of apelin in BeWo cells was mediated by the APJ receptor and mitogen-activated protein kinase (ERK1/2/MAP3/1) and protein kinase B (AKT). The obtained results showed the antiapoptotic effect of apelin on trophoblast cells, suggesting its participation in the development of the placenta.

The Anti-apoptosis Effect of Single Electroacupuncture Treatment via Suppressing Neuronal Autophagy in the Acute Stage of Ischemic Stroke Without Infarct Alleviation

The main purpose of the study was to investigate the antiapoptotic effect of electroacupuncture (EA) in the acute stage of ischaemic stroke in rats. The cerebral ischemia model was established by middle cerebral artery occlusion (MCAO)/reperfusion in rats. A single EA treatment was performed at the acute stage of ischaemic stroke. The neurological function, brain water content, apoptotic cell number, and cerebral infarct volume were assessed in stroke rats. The expression of autophagy-related proteins (LC3II/I, Beclin1, P62, and LAMP1), Sirtuin 1 (SIRT1), p-JNK, p-ERK1/2, and cleaved caspase-3 (CCAS3) were measured by Western blot, immunofluorescence, and immunohistochemistry. Rapamycin (RAP, an activator of autophagy) was used to confirm the antiapoptotic effect of EA via regulating autophagy. The brain edema infarct size and apoptotic cell number were increasing within 3 days following stroke, and brain edema reached its peak at 24 h after stroke. EA treatment at 24 h after ischaemic stroke obviously suppressed the number of apoptotic cells and brain edema. However, there were no significant differences in infarct volumes among EA-12 h, EA-24 h, and MCAO/R group. Moreover, EA treatment at 24 h after ischaemic stroke obviously suppressed the expression of CCAS3, LC3II/I, Beclin1 while increasing the level of P62 and LAMP1 and hence mediating autophagy, which was reversed by RAP. Meanwhile, the expression of SIRT1, p-ERK1/2, p-JNK were promoted by EA at 24 h after ischaemic stroke. In conclusion, EA treatment may suppress apoptosis possibly via regulating autophagy in the acute period after ischaemic stroke, hence reducing brain injury.

Notch signaling is involved in the antiapoptotic effects of liraglutide on rat H9c2 cardiomyocytes exposed to hypoxia followed by reoxygenation

Objective Liraglutide (Lir) protects cardiomyocytes against high glucose-induced myocardial damage. This study investigated whether Notch signaling participated in the antiapoptotic effects of Lir on rat H9c2 cardiomyocytes subjected to hypoxia followed by reoxygenation (H/R). Methods We used H9c2 rat cardiomyocytes as a model of H/R and measured viability, apoptosis, and expression of the apoptotic genes Bax and Bcl-2 and Notch signaling genes Notch1 and Jagged1. Notch1 was depleted by siRNA to test the effect of Notch1 deficiency on the antiapoptotic effects of Lir on H/R-treated H9c2 cardiomyocytes. Results After H/R treatment, viability was significantly decreased, and the apoptosis rate was greater in the H/R group than in the control (CT). Lir at 50, 100, and 200 nM significantly increased viability and decreased apoptosis in H/R-treated H9c2 cells. Treatment with 50 nM Lir for 2 hours before H/R significantly increased the expression levels of Notch1, Jagged1, and Bcl-2 compared with the CT levels. Bax was downregulated, which indicated that Lir activated Notch signaling and inhibited apoptosis. Notch1 depletion partially abolished the antiapoptotic effect of Lir on H/R-treated H9c2 cells by altering apoptotic gene expression. Conclusion Lir activated Notch signaling, which was responsible for the antiapoptotic effect of Lir on H9c2 cardiomyocytes.

miRNA transfection via poly(amidoamine)-based delivery vector prevents hypoxia/reperfusion-induced cardiomyocyte apoptosis

Aim: Myocardial infarction is a tissue injury that leads to apoptosis of cardiomyocytes. This can be prevented by using miRNAs, but its delivery to cardiomyocytes is a major hurdle. We aimed to deliver miRNAs using poly(amidoamine)-histidine (PAMAM-His) nanocarriers to prevent apoptosis. Materials & methods: The PAMAM-His nanoparticles were synthesized and assessed for their transfection efficiency of miRNAs to prevent apoptosis in hypoxia/reperfusion-induced H9c2 as well as primary cultured cardiomyocytes. Results & conclusion: miRNAs-nanoparticle complexes exerted a significant antiapoptotic effect on the H9c2 and primary rat ventricular cardiomyocytes. Enhanced expression of antiapoptotic genes and decreased expression of proapoptotic genes were observed. PAMAM-His nanoparticles effectively delivered miRNAs to the cardiomyocytes and prevented the hypoxia/reperfusion-induced apoptosis critical in myocardial infarctions.