Salidroside attenuates cardiac dysfunction in a rat model of diabetes

Tinglu Yixin granule inhibited fibroblast-myofibroblast transdifferentiation to ameliorate myocardial fibrosis in diabetic mice

ETHNOPHARMACOLOGICAL RELEVANCE

Myocardial fibrosis is one of the pathological characteristics of advanced diabetic cardiomyopathy (DCM) and serves as the strong evidence of poor prognosis. Among them, the transdifferentiation of cardiac fibroblasts (CFs) may play a crucial role in the development of myocardial fibrosis in DCM. Tinglu Yixin granule (TLYXG) has been clinically used for many years and can significantly improve cardiac function of patients with DCM. However, the effect of TLYXG on myocardial fibrosis in DCM remains unknown, and the underlying mechanisms of its efficacy have yet to be fully understood.

AIM OF THE STUDY

This study aimed to investigate the impact and underlying mechanism of TLYXG on myocardial fibrosis in diabetes mice.

MATERIALS AND METHODS

The bioactive compounds in TLYXG were identified using ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). The potential mechanism of TLYXG in treating DCM was predicted using network pharmacology combined with molecular docking and protein-protein docking. The mice model of type 2 diabetes were established by intraperitoneal injection of streptozotocin (STZ) and the high-fat diet (HFD). Indicators of pancreatic islet function, lipids, oxidative stress, and inflammatory factors were tested using kits. Cardiac function was assessed in diabetic mice using echocardiography. Histologic staining was performed to evaluate myocardial hypertrophy and fibrosis. Mechanistically, the hypothesis was tested through rescue experiments. The expression levels of transient receptor potential channel 6 (TRPC6), transforming growth factor-β1 (TGF-β1), collagen I (COL-I) and alpha-smooth muscle actin (α-SMA), along with the mRNA and phosphorylation levels of SMAD family member 3 (Smad3) and protein 38 mitogen-activated protein kinase (p38 MAPK), were assessed using quantitative RT-qPCR, Western blot, immunohistochemistry, and immunofluorescence. Neonatal lactating mice were used to extract primary CFs for vitro experiments. Scratch and transwell assays were conducted to assess CFs migration and invasion abilities. Western blot and immunofluorescence were used to evaluate the expression levels of CFs transdifferentiation markers COL-I and α-SMA.

RESULTS

A total of 168 active ingredients were detected in TLYXG based on UPLC-MS and databases. Network pharmacology indicated that TLYXG could improve DCM through inflammatory mediator regulation of TRP channels, TGF-beta signaling pathway, and MAPK signaling pathway. ELISA results showed that TLYXG could ameliorate metabolic levels, inflammation, and oxidative stress in diabetic mice. Echocardiography suggested that TLYXG improved cardiac systolic and diastolic dysfunction in diabetic mice. Histological analysis revealed that TLYXG alleviated myocardial fibrosis in diabetes mice. Additionally, molecular docking analysis indicated strong binding activity between the main active ingredients of TLYXG and TRPC6 of the TRP family. At the molecular level, TLYXG reduced the mRNA and protein expression levels of TRPC6 and TGF-β1 and inhibited the mRNA and phosphorylation levels of Smad3 and p38 MAPK. Furthermore, TLYXG inhibited CFs migration and invasion, and reduced the expression levels of the CFs transdifferentiation markers COL-I and α-SMA.

CONCLUSION

TLYXG inhibited the proliferation, migration, invasion and transdifferentiation of CFs by suppressing TGF-β1/Smad3/p38 MAPK signaling through down-regulation of TRPC6, thereby ameliorating myocardial fibrosis in diabetes mice.

Salidroside treatment decreases the susceptibility of atrial fibrillation in diabetic mice by reducing mTOR-STAT3-MCP-1 signaling and atrial inflammation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in clinic, and type 2 diabetes mellitus (T2DM) is an independent risk factor for AF. Salidroside (Sal), the active ingredient of the Rhodiola rosea, has hypoglycemic, anti-inflammatory, anti-fibrotic and anti-arrhythmic effects. The aim of this study is to investigate the effects and underlying molecular mechanisms of Sal on T2DM associated atrial inflammation and the pathogenesis of AF. In the in vivo study, T2DM mice model was established by high-fat diet and intraperitoneal injection of streptozotocin (STZ). Sal (25 mg/kg/d, 50 mg/kg/d, and 100 mg/kg/d) was administered orally for 4 weeks. T2DM caused atrial electrical and structural remodeling and significantly increased the susceptibility of AF. Meanwhile, mTOR-STAT3-MCP-1 signaling and inflammatory markers were also significantly enhanced in diabetic atria. However, Sal dose-dependently ameliorated cardiac dysfunction, mitigated atrial structural and electrical remodeling, and reduced atrial inflammation. Moreover, Sal-treated group exhibited remarkably down-regulated activity of mTOR-STAT3-MCP-1 pathway, and decreased atrial monocyte/macrophage infiltration. In palmitic acid (PA)-challenged HL-1 cells, Sal attenuated cytotoxicity, downregulated the expressions of TNF-α, IL-6, MCP-1, and inhibited the activation of mTOR-STAT3 signaling. However, co-treatment with MHY1485 (a mTOR agonist) reversed these effects. Taken together, the present study demonstrates that Sal treatment decreases the susceptibility of AF in diabetic mice by reducing mTOR-STAT3-MCP-1 signaling and atrial monocyte/macrophage infiltration. Sal treatment may represent a novel preventive therapy for cardiac arrhythmia and atrial fibrillation in diabetic patients.

Salidroside attenuates myocardial remodeling in DOCA-salt-induced mice by inhibiting the endothelin 1 and PI3K/AKT/NFκB signaling pathways

Myocardial remodeling, which occurs in the final stage of cardiovascular diseases such as hypertension, can ultimately result in heart failure. However, the pathogenesis of myocardial remodeling remains incompletely understood, and there is currently a lack of safe and effective treatment options. Salidroside, which is extracted from the plant Rhodiola rosea, shows remarkable antioxidant and anti-inflammatory characteristics. The purpose of this investigation was to examine the cardioprotective effect of salidroside on myocardial remodeling, and clarify the associated mechanism. Salidroside effectively attenuated cardiac dysfunction, myocardial hypertrophy, myocardial fibrosis, and cardiac inflammation, as well as renal injury and renal fibrosis in an animal model of deoxycortone acetate (DOCA)-salt-induced myocardial remodeling. The cardioprotective effect of salidroside was mediated by inhibiting the endothelin 1 and PI3K/AKT/NFκB signaling pathways. Salidroside was shown to inhibit the expression of endothelin1 in the hearts of mice treated with DOCA-salt. Additionally, it could prevent cardiomyocyte hypertrophy induced by endothelin-1 stimulation. Furthermore, Salidroside could effectively inhibit the excessive activation of the PI3K/AKT/NFκB pathway, which was caused by DOCA-salt treatment in mouse hearts and endothelin 1 stimulation in cardiomyocytes. Our study suggests that salidroside can be used as a therapeutic agent for the treatment of myocardial remodeling.

A cross-talk between sestrins, chronic inflammation and cellular senescence governs the development of age-associated sarcopenia and obesity

The rapid increase in both the lifespan and proportion of older adults is accompanied by the unprecedented rise in age-associated chronic diseases, including sarcopenia and obesity. Aging is also manifested by increased susceptibility to multiple endogenous and exogenous stresses enabling such chronic conditions to develop. Among the main physiological regulators of cellular adaption to various stress stimuli, such as DNA damage, hypoxia, and oxidative stress, are sestrins (Sesns), a family of three evolutionarily conserved proteins, Sesn1, 2, and 3. Age-associated sarcopenia and obesity are characterized by two key processes: (i) accumulation of senescent cells in the skeletal muscle and adipose tissue and (ii) creation of a systemic, chronic, low-grade inflammation (SCLGI). Presumably, failed SCLGI resolution governs the development of these chronic conditions. Noteworthy, Sesns activate senolytics, which are agents that selectively eliminate senescent cells, as well as specialized pro-resolving mediators, which are factors that physiologically provide inflammation resolution. Sesns reveal clear beneficial effects in pre-clinical models of sarcopenia and obesity. Based on these observations, we propose a novel treatment strategy for age-associated sarcopenia and obesity, complementary to the conventional therapeutic modalities: Sesn activation, SCLGI resolution, and senescent cell elimination.

Emerging Roles of SIRT3 in Cardiac Metabolism

The heart is a highly metabolically active organ that predominantly utilizes fatty acids as an energy substrate. The heart also derives some part of its energy by oxidation of other substrates, including glucose, lactose, amino acids and ketones. The critical feature of cardiac pathology is metabolic remodeling and loss of metabolic flexibility. Sirtuin 3 (SIRT3) is one of the seven mammalian sirtuins (SIRT1 to SIRT7), with NAD⁺ dependent deacetylase activity. SIRT3 is expressed in high levels in healthy hearts but downregulated in the aged or diseased hearts. Experimental evidence shows that increasing SIRT3 levels or activity can ameliorate several cardiac pathologies. The primary deacetylation targets of SIRT3 are mitochondrial proteins, most of which are involved in energy metabolism. Thus, SIRT3 improves cardiac health by modulating cardiac energetics. In this review, we discuss the essential role of SIRT3 in regulating cardiac metabolism in the context of physiology and pathology. Specifically, we summarize the recent advancements that emphasize the critical role of SIRT3 as a master regulator of cardiac metabolism. We also present a comprehensive view of all known activators of SIRT3, and elaborate on their therapeutic potential to ameliorate energetic abnormalities in various cardiac pathologies.

Mechanisms and Efficacy of Traditional Chinese Medicine in Heart Failure

Heart failure (HF) is one of the main public health problems at present. Although some breakthroughs have been made in the treatment of HF, the mortality rate remains very high. However, we should also pay attention to improving the quality of life of patients with HF. Traditional Chinese medicine (TCM) has a long history of being used to treat HF. To demonstrate the clinical effects and mechanisms of TCM, we searched published clinical trial studies and basic studies. The search results showed that adjuvant therapy with TCM might benefit patients with HF, and its mechanism may be related to microvascular circulation, myocardial energy metabolism, oxidative stress, and inflammation.