Gentianella acuta improves TAC-induced cardiac remodelling by regulating the Notch and PI3K/Akt/FOXO1/3 pathways.

Cardiac remodelling mainly manifests as excessive myocardial hypertrophy and fibrosis, which are associated with heart failure. Gentianella acuta (G. acuta) is reportedly effective in cardiac protection; however, the mechanism by which it protects against cardiac remodelling is not fully understood. Here, we discuss the effects and mechanisms of G. acuta in transverse aortic constriction (TAC)-induced cardiac remodelling in rats. Cardiac function was analysed using echocardiography and electrocardiography. Haematoxylin and eosin, Masson's trichrome, and wheat germ agglutinin staining were used to observe pathophysiological changes. Additionally, real-time quantitative reverse transcription polymerase chain reaction and western blotting were used to measure protein levels and mRNA levels of genes related to myocardial hypertrophy and fibrosis. Immunofluorescence double staining was used to investigate the co-expression of endothelial and interstitial markers. Western blotting was used to estimate the expression and phosphorylation levels of the regulatory proteins involved in autophagy and endothelial-mesenchymal transition (EndMT). The results showed that G. acuta alleviated cardiac dysfunction and remodelling. The elevated levels of myocardial hypertrophy and fibrosis markers, induced by TAC, decreased significantly after G. acuta intervention. G. acuta decreased the expression of LC3 II and Beclin1, and increased p62 expression. G. acuta upregulated the expression of CD31 and vascular endothelial-cadherin, and prevented the expression of α-smooth muscle actin and vimentin. Furthermore, G. acuta inhibited the PI3K/Akt/FOXO1/3a pathway and activated the Notch signalling. These findings demonstrated that G. acuta has cardioprotective effects, such as alleviating myocardial fibrosis, inhibiting hypertrophy, reducing autophagy, and blocking EndMT by regulating the PI3K/Akt/FOXO1/3a and Notch signalling pathways.

Salvia miltiorrhiza-derived miRNAs suppress vascular remodeling through regulating OTUD7B/KLF4/NMHC IIA axis.

Objective: Abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are essential for vascular remodeling. Natural compounds with diterpene chinone or phenolic acid structure from Salvia miltiorrhiza, an eminent medicinal herb widely used to treat cardiovascular diseases in China, can effectively attenuate vascular remodeling induced by vascular injury. However, it remains unknown whether Salvia miltiorrhiza-derived miRNAs can protect VSMCs from injury by environmental stimuli. Here, we explored the role and underlying mechanisms of Salvia miltiorrhiza-derived Sal-miR-1 and 3 in the regulation of VSMC migration and monocyte adhesion to VSMCs induced by thrombin. Methods: A mouse model for intimal hyperplasia was established by the ligation of carotid artery and the injured carotid arteries were in situ-transfected with Sal-miR-1 and 3 using F-127 pluronic gel. The vascular protective effects of Sal-miR-1 and 3 were assessed via analysis of intimal hyperplasia with pathological morphology. VSMC migration and adhesion were analyzed by the wound healing, transwell membrane assays, and time-lapse imaging experiment. Using loss- and gain-of-function approaches, Sal-miR-1 and 3 regulation of OTUD7B/KLF4/NMHC IIA axis was investigated by using luciferase assay, co-immunoprecipitation, chromatin immunoprecipitation, western blotting, etc. Results:Salvia miltiorrhiza-derived Sal-miR-1 and 3 can enter the mouse body after intragastric administration, and significantly suppress intimal hyperplasia induced by carotid artery ligation. In cultured VSMCs, these two miRNAs inhibit thrombin-induced the migration of VSMCs and monocyte adhesion to VSMCs. Mechanistically, Sal-miR-1 and 3 abrogate OTUD7B upregulation by thrombin via binding to the different sites of the OTUD7B 3'UTR. Most importantly, OTUD7B downregulation by Sal-miR-1 and 3 attenuates KLF4 protein levels via decreasing its deubiquitylation, whereas decreased KLF4 relieves its repression of transcription of NMHC IIA gene and thus increases NMHC IIA expression levels. Further, increased NMHC IIA represses VSMC migration and monocyte adhesion to VSMCs via maintaining the contractile phenotype of VSMCs. Conclusions: Our studies not only found the novel bioactive components from Salvia miltiorrhiza but also clarified the molecular mechanism underlying Sal-miR-1 and 3 inhibition of VSMC migration and monocyte adhesion to VSMCs. These results add important knowledge to the pharmacological actions and bioactive components of Salvia miltiorrhiza. Sal-miR-1 and 3-regulated OTUD7B/KLF4/NMHC IIA axis may represent a therapeutic target for vascular remodeling.

Salvia miltiorrhiza-Derived Sal-miR-58 Induces Autophagy and Attenuates Inflammation in Vascular Smooth Muscle Cells.

Autophagy is associated with the cytoprotection of physiological processes against inflammation and oxidative stress. Salvia miltiorrhiza possesses cardiovascular protective actions and has powerful anti-oxidative and anti-inflammatory effects; however, whether and how Salvia miltiorrhiza-derived microRNAs (miRNAs) protect vascular smooth muscle cells (VSMCs) by inducing autophagy across species are unknown. We first screened and identified Sal-miR-58 from Salvia miltiorrhiza as a natural autophagy inducer. Synthetic Sal-miR-58 suppresses chronic angiotensin II (Ang II) infusion-induced abdominal aortic aneurysm (AAA) formation in mice, as well as induces autophagy in VSMCs and attenuates the inflammatory response elicited by Ang II in vivo and in vitro. Mechanistically, Sal-miR-58 downregulates Krüppel-like factor 3 (KLF3) expression through direct binding to the 3' UTR of KLF3, which in turn relieves KLF3 repression of E3 ubiquitin ligase neural precursor cell-expressed developmentally downregulated 4-like (NEDD4L) expression, whereas NEDD4L upregulation increases the ubiquitination and degradation of the platelet isoform of phosphofructokinase (PFKP), subsequently leading to a decrease in the activation of Akt/mammalian target of rapamycin (mTOR) signaling and facilitating VSMC autophagy induced by Sal-miR-58 in the context of chronic Ang II stimulation and aneurysm formation. Our results provide the first evidence that plant-derived Sal-miR-58 induces autophagy and attenuates inflammation in VSMCs through cross-species modulation of the KLF3/NEDD4L/PFKP regulatory pathway.

Tanshinone â ¡A inhibits VSMC inflammation and proliferation in vivo and in vitro by downregulating miR-712-5p expression.

The inflammation and proliferation of vascular smooth muscle cells (VSMCs) are the basic pathological feature of proliferative vascular diseases. Tanshinone ⅡA (Tan ⅡA), which is the most abundant fat-soluble element extracted from Salvia miltiorrhiza, has potent protective effects on the cardiovascular system. However, the underlying mechanism is still not fully understood. Here, we show that Tan ⅡA significantly inhibits neointimal formation and decreases VSMC inflammation by upregulating the expression of KLF4 and inhibiting the activation of NFκB signaling. Using a microRNA array analysis, we found that miR-712-5p expression is significantly upregulated in tumor necrosis factor alpha (TNF-α)-treated VSMCs. Loss- and gain-of-function experiments revealed that transfection of miR-712-5p mimic promotes, whereas depletion of miR-712-5p suppresses TNF-α-induced VSMC inflammation, leading to amelioration of intimal hyperplasia induced by carotid artery ligation. Moreover, depletion of miR-712-5p by its antagomir largely abrogates TNF-α-induced VSMC proliferation. Our findings suggest that miR-712-5p mediates the stimulatory effect of TNF-α on VSMC inflammation, and that Tan ⅡA inhibits VSMC inflammation and proliferation in vivo and in vitro by suppression of miR-712-5p expression. Targeting miR-712-5p may be a novel therapeutic strategy to prevent proliferative vascular diseases.

Morin Inhibits Proliferation and Induces Apoptosis by Modulating the miR-188-5p/PTEN/AKT Regulatory Pathway in CML Cells.

Increased activity of the PI3K/AKT/mTOR pathway has been observed in chronic myeloid leukemia (CML). Morin, a kind of flavonoid, exhibits a significant anticancer activity by suppressing the PI3K/AKT signaling pathway. However, the effect of morin on CML and its underlying mechanisms is poorly understood. Here, we found that morin dose dependently inhibited the proliferation of CML cell lines K562 and KCL22 and induced their apoptosis, with a significant increase in cell apoptosis upon exposure of cells to 50 µmol/L morin. Moreover, morin significantly reduced CML xenograft growth in nude mice. Mechanically, morin attenuated phosphorylated AKT level by upregulating PTEN expression, thus leading to the inhibition of AKT signaling. Knockdown of PTEN by its siRNA completely abrogated morin-induced cell apoptosis, indicating that PTEN mediates the inductive effect of morin on CML cell apoptosis. More importantly, we found that miR-188-5p was significantly upregulated in CML patients and CML cell lines. Treating CML cells with morin markedly downregulated the miR-188-5p expression level. Further, we demonstrated that miR-188-5p repressed PTEN expression by directly targeting its 3'-UTR. miR-188-5p downregulation induced by morin enhanced CML cell apoptosis by relieving miR-188-5p repression of PTEN expression. In summary, morin exerts significant anticancer efficacy in CML by regulating the miR-188-5p/PTEN axis and thus repressing the PI3K/AKT signaling.