Tianma Gouteng Decoction Exerts Cardiovascular Protection by Upregulating OPG and TRAIL in Spontaneously Hypertensive Rats.

Tianma Gouteng Decoction (TGD) is widely used in traditional Chinese medicine for the treatment of hypertension and its related complications, but its mechanisms remain incompletely defined. We now aim to assess the protective effect of TGD against cardiovascular damage and to investigate its characteristics and underlying mechanisms. Blood pressure was determined in TGD-treated spontaneously hypertensive rats (SHR) by noninvasive measurements. Echocardiography was performed to assess cardiac function and structure and sirius red staining to evaluate cardiac fibrosis, and the degree of vascular remodeling was evaluated. Additionally, vasoconstriction and relaxation factor expression changes were examined by means of ELISA. Protein expression changes were verified by western blot. Compared with untreated SHR, TGD-treated SHR exhibited cardiovascular traits more akin to those of the normotensive Wistar Kyoto (WKY) rats. That is, they had lower diastolic blood pressure, systolic blood pressure and mean BP, and increased expression of vasodilation factor. We also found that TGD reduces ventricular and vascular remodeling and improves cardiac function in SHR. Finally, we tested the antiapoptosis effect TGD exerts in SHR, ostensibly by upregulating the expression of OPG, TRAIL, and death receptor 5 (DR5) and downregulating caspases 8, 7, and 3. TRAIL may also exert antiapoptotic and prosurvival effects by upregulating AKT expression. Therefore, TGD may reverse cardiovascular remodeling in SHR by upregulating the expression of OPG and TRAIL, upregulating AKT, and inhibiting apoptosis, at least in part. For the first time, we have shown that OPG and TRAIL play complimentary cardioprotective roles in SHR.

SERCA2a: a key protein in the Ca2+ cycle of the heart failure.

Calcium ion (Ca2+) cycle plays a crucial role in the contraction and relaxation of cardiomyocytes. The sarcoplasmic reticulum (SR) acts as an organelle for storing Ca2+, which mediated the release and re-uptake of Ca2+ during contraction and relaxation. Disorders of SR function lead to the dysfunction of Ca2+ cycle and myocardial cell function. The sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a (SERCA2a) acts as a subtype of SERCA expressed in the heart, which mediates the contraction of cardiomyocytes and Ca2+ in the cytoplasm to re-enter into the SR. The rate of uptake of Ca2+ by the SR determines the rate of myocardial relaxation. The regulation of SERCA2a activity controls the contractility and relaxation of the heart, affecting cardiac function. The expression and activity of SERCA2a are reduced in failing hearts. Gene therapy by increasing the expression of SERCA2a in the heart has been proven effective. In addition, SERCA2a is regulated by a variety of factors, including transmembrane micropeptides, protein kinases, and post-translational modifications (PTMs). In this review, we discuss the regulatory factors of SERCA2a and provide new insights into future treatments and the direction of heart failure research. In addition, gene therapy for SERCA2a has recently emerged as therapeutic option and hence will be discussed in this review.

Mitochondrial dynamics modulation as a critical contribution for Shenmai injection in attenuating hypoxia/reoxygenation injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Shenmai injection (SMI) is a CFDA-approved and widely prescribed herbal medicine injection in China for treating cardiac dysfunction, especially myocardial ischemia and reperfusion (I/R) injury. However, despite of its known clinical efficacy, the cardioprotective mechanisms of SMI remain to be established. AIM OF STUDY: The present study aimed to investigate the role of SMI on mitophagy and mitochondrial dynamics in cardiomyocytes with a hypoxia/reperfusion (H/R) injury setting. MATERIALS AND METHODS: H9c2 cardiomyocytes were subjected to 12 h of hypoxia followed by 2 h of reoxygenation to induce cellular injury. Multi-parameter imaging analysis was performed using Operetta High Content Imaging System to detect changes in mitochondrial function and morphological texture. The mPTP opening was directly assessed by analyzing mitochondrial calcein release in H9c2 and by Ca2+-induced swelling of isolated cardiac mitochondria. Mitochondrial respiration was measured by XF 24 analyzer of Seahorse Bioscience. RT-PCR and Western blotting analyses were used to detect mitophagy, mitochondrial fusion and fission biomarkers at the gene and protein levels. RESULTS: Pretreatment of SMI significantly improved myocardial cell survival and protected against H/R-induced deterioration of mitochondrial structure and function, as evidenced by decreased mitochondrial mass and cytosolic Ca2+, increased mitochondrial membrane potential (ΔΨm) and mitochondrial morphology by SER Texture analysis, inhibited mPTP opening in H9c2 cells and isolated cardiac mitochondria, and alleviated severely impaired mitochondrial respiration. Mechanistically, SMI attenuated H/R injury by inducing mitophagy and then modulated mitochondrial dynamics as indicated by a significantly increased expression of LC3, Beclin 1, Parkin and Pink, and the inhibition of excessive mitochondria fission and increased mitochondrial fusion. Finally, the cardioprotective effect of SMI was confirmed in a LAD-induced cardiac dysfunction model in vivo. CONCLUSION: We found that alleviation of H/R injury by pretreatment with SMI may be attributable to inducing mitophagy and modulating mitochondrial dynamics in cardiomyocytes, thereby providing a rationale for future clinical applications and potential mitoprotective therapy for MI/R injury.