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Hypertension is a severe public health risk factor worldwide. Elevated angiotensin II (Ang II) produced by the renin-angiotensin-aldosterone system can lead to hypertension and its complications.In this study, we addressed the cardiac-injury effects of Ang II and investigated the signaling mechanism induced by Ang II. Both H9c2 cardiomyoblast cells and neonatal rat cardiomyocytes were exposed to Ang II to observe hypertension-related cardiac apoptosis.The results of western blotting revealed that Ang II significantly attenuated the IGF1R-PI3K-AKT pathway via the Ang II-AT1 receptor axis and phosphatase and tensin homolog expression. Furthermore, real-time PCR showed that Ang II also activated miR-320-3p transcription to repress the PI3K-Akt pathway. In the heart tissue of spontaneously hypertensive rats, activation of the IGF1R survival pathway was also reduced compared with that in Wistar-Kyoto rats, especially in aged spontaneously hypertensive rats.Hence, we speculate that the Ang II-AT1 receptor axis induces both phosphatase and tensin homolog and miR-320-3p expression to downregulate the IGF1R-PI3K-AKT survival pathway and cause cell apoptosis in the heart.

Heart failure (HF) and cardiac hypertrophy is an unfavorable outcome of pathological cardiac remodeling and represents the most important contributing factor for HF and cardiac hypertrophy. Amygdalin (AMG) is a cyanogenic glycoside derived from bitter almonds. Accumulating evidences have highlighted their pharmacological potentials against various diseases. However, there is no report delineating the potential of AMG against angiotensin (Ang II) induced cardiac injuries. Thus, the present study was performed to explore whether AMG could ameliorate Ang II induced cardiomyopathies and thereby ascertain the underlying mechanisms thereof. To this end, H9c2 cells were treated with Ang II and thereafter treated with various concentration of AMG and finally the cardio-protective effects of AMG were analyzed through Western blotting, immunofluorescence, and insilico analysis. Our results showed that the cardiomyocyte cell size, inflammatory markers and cytokines(pNF-κB, TNF-α, iNOS and COX-2) were markedly increased following Ang II treatment; nevertheless, treatment with AMG led to considerable decrement in the Ang II induced enlargement of the cardiomyocytes, and attenuate the expression of hypertrophic markers(ANP, BNP and MHC-7), inflammatory markers and cytokines. Additionally, oxidative stress related proteins (Nrf2, catalase, SOD-2, and GPX-4) were markedly increased following AMG treatment. Molecular docking reveals the interaction of AMG with Nrf2 possessing good binding affinity. Cumulatively, our study highlights the cardio-protective role of AMG against Ang II induced cardiomyopathies, including oxidative stress and inflammation effects. The intriguing in vitro results warrants the need of further animal studies to truly ascertain their potentialities.