Mechanism Actions of Coniferyl Alcohol in Improving Cardiac Dysfunction in Renovascular Hypertension Studied by Experimental Verification and Network Pharmacology.

Renovascular hypertension (RH), a secondary hypertension, can significantly impact heart health, resulting in heart damage and dysfunction, thereby elevating the risk of cardiovascular diseases. Coniferol (CA), which has vascular relaxation properties, is expected to be able to treat hypertension-related diseases. However, its potential effects on cardiac function after RH remain unclear. In this study, in combination with network pharmacology, the antihypertensive and cardioprotective effects of CA in a two-kidney, one-clip (2K1C) mice model and its ability to mitigate angiotensin II (Ang II)-induced hypertrophy in H9C2 cells were investigated. The findings revealed that CA effectively reduced blood pressure, myocardial tissue damage, and inflammation after RH. The possible targets of CA for RH treatment were screened by network pharmacology. The interleukin-17 (IL-17) and tumor necrosis factor (TNF) signaling pathways were identified using a Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The inflammatory response was identified using a Gene Ontology (GO) enrichment analysis. Western blot analysis confirmed that CA reduced the expression of IL-17, matrix metallopeptidase 9 (MMP9), cyclooxygenase 2 (COX2), and TNF α in heart tissues and the H9C2 cells. In summary, CA inhibited cardiac inflammation and fibrohypertrophy following RH. This effect was closely linked to the expression of MMP9/COX2/TNF α/IL-17. This study sheds light on the therapeutic potential of CA for treating RH-induced myocardial hypertrophy and provides insights into its underlying mechanisms, positioning CA as a promising candidate for future drug development.

Apigenin Attenuates Transverse Aortic Constriction-Induced Myocardial Hypertrophy: The Key Role of miR-185-5p/SREBP2-Mediated Autophagy.

Introduction: Apigenin is a natural flavonoid compound with promising potential for the attenuation of myocardial hypertrophy (MH). The compound can also modulate the expression of miR-185-5p that both promote MH and suppress autophagy. The current attempts to explain the anti-MH effect of apigenin by focusing on changes in miR-185-5p-mediated autophagy. Methods: Hypertrophic symptoms were induced in rats using transverse aortic constriction (TAC) method and in cardiomyocytes using Ang II and then handled with apigenin. Changes in myocardial function and structure and cell viability and surface area were measured. The role of miR-185-5p in the anti-MH function of apigenin was explored by detecting changes in autophagic processes and miR-185-5p/SREBP2 axis. Results: TAC surgery induced weight increase, structure destruction, and collagen deposition in hearts of model rats. Ang II suppresses cardiomyocyte viability and increased cell surface area. All these impairments were attenuated by apigenin and were associated with the restored level of autophagy. At the molecular level, the expression of miR-185-5p was up-regulated by TAC, while the expression of SREBP2 was down-regulated, which was reserved by apigenin both in vivo and in vitro. The induction of miR-185-5p in cardiomyocytes could counteracted the protective effects of apigenin. Discussion: Collectively, the findings outlined in the current study highlighted that apigenin showed anti-MH effects. The effects were related to the inhibition of miR-185-5p and activation of SREBP, which contributed to the increased autophagy.

Transcriptome sequencing analysis reveals the molecular regulatory mechanism of myocardial hypertrophy induced by angiotensin II.

The pathogenesis of myocardial hypertrophy remains incompletely understood, highlighting the critical need for in-depth investigation into its pathogenesis and pathophysiology to develop innovative strategies for preventing and treating heart diseases. In this study, a model of angiotensin II (Ang II)-induced myocardial hypertrophy was established using subcutaneous administration with a micropump. Echocardiography, wheat germ agglutinin staining, and western blot analysis were used to evaluate the myocardial hypertrophy model after 5, 10, and 15 days of Ang II treatment. RNA-seq was employed to analyze the differential expression profile of mRNA, followed by bioinformatics analysis. Subsequently, the anti-inflammatory drug meloxicam was utilized to explore its impact on cardiac hypertrophy in mice. The findings demonstrated that mice developed myocardial hypertrophy following subcutaneous administration of Ang II. Transcriptomic analysis revealed significant changes in gene expression in the myocardium induced by Ang II, with the most pronounced differences observed at day 10. Functional analysis and verification of differentially expressed genes indicated that Ang II triggered an inflammatory response in the myocardium, leading to up-regulation of genes associated with fibrosis and apoptosis while decreasing energy metabolism; alterations were also observed in genes related to oxidative stress and calcium ion binding. Treatment with meloxicam improved Ang II-induced myocardial hypertrophy. This study not only elucidated the molecular regulatory mechanism underlying mouse myocardial hypertrophy at a transcriptional level but also provided new insights into clinical prevention and treatment strategies for cardiac diseases such as dilated cardiomyopathy and heart failure.

Inhibition of MMP2 activity mitigates N-omega-nitro-l-arginine-methyl ester (l-NAME)-induced right heart failure.

In rats decreased bioavailability of nitric oxide induces oxidative stress and right heart failure. Oxidative stress can activate matrix metalloproteinase-2 (MMP2). We addressed the question whether increasing oxidative defense by administration of the SOD mimetic Tempol or direct inhibition of MMP2 activity by SB-3CT mitigates right heart failure. Rats received l-NAME for four weeks and during week three and four treatment groups received either Tempol or SB-3CT in addition. After four weeks heart function was analyzed by echocardiography, organ weights and expression of NPPB and COL1A1 were analyzed, oxidative stress was monitored by DHE-staining and MMP2 activity was quantified by proteolytic auto-activation, zymography, and troponin I degradation. l-NAME induced oxidative stress and MMP2 activity stronger in the right ventricle than in the left ventricle. Troponin I, a MMP2 substrate, was degraded in right ventricles. Tempol reduced oxidative stress and preferentially affected the expression of fibrotic genes (i.e. COL1A1) and fibrosis. Tempol and SB-3CT mitigated right but not left ventricular hypertrophy. Neither SB-3CT nor Tempol alone strongly improved right ventricular function. In conclusion, both MMP2 activity and oxidative stress contribute to right ventricular failure but neither is MMP2 activation linked to oxidative stress nor does oxidative stress and MMP2 activity have common targets.

CaMK II in Cardiovascular Diseases, Especially CaMK II-δ: Friends or Enemies.

Cardiovascular diseases (CVDs) tend to affect the young population and are associated with a significant economic burden and psychological distress to the society and families. The physiological and pathological processes underlying CVDs are complex. Ca2+/calmodulin-dependent kinase II (CaMK II), a protein kinase, has multiple biological functions. It participates in multiple pathological processes and plays a central role in the development of CVDs. Based on this, this paper analyzes the structural characteristics and distribution of CaMK II, the mechanism of action of CaMK II, and the relationship between CaMK II and CVDs, including ion channels, ischemia-reperfusion injury, arrhythmias, myocardial hypertrophy, cardiotoxicity, hypertension, and dilated cardiomyopathy. Given the different regulatory mechanisms of different isoforms of CaMK II, the clinical use of specific targeted inhibitors or novel compounds should be evaluated in future research to provide new directions.

Mesenchymal stem cells may alleviate angiotensin II-induced myocardial fibrosis and hypertrophy by upregulating SFRS3 expression.

INTRODUCTION AND OBJECTIVES: The development of cardiac fibrosis (CF) and hypertrophy (CH) can lead to heart failure. Mesenchymal stem cells (MSCs) have shown promise in treating cardiac diseases. However, the relationship between MSCs and splicing factor arginine/serine rich-3 (SFRS3) remains unclear. In this study, our objectives are to investigate the effect of MSCs on SFRS3 expression, and their impact on CF and CH. Additionally, we aim to explore the function of the overexpression of SFRS3 in angiotensin II (Ang II)-treated cardiac fibroblasts (CFBs) and cardiac myocytes (CMCs). METHODS: Rat cardiac fibroblasts (rCFBs) or rat cardiac myocytes (rCMCs) were co-cultured with rat MSCs (rMSCs). The function of SFRS3 in Ang II-induced rCFBs and rCMCs was studied by overexpressing SFRS3 in these cells, both with and without the presence of rMSCs. We assessed the expression of SFRS3 and evaluated the cell cycle, proliferation and apoptosis of rCFBs and rCMCs. We also measured the levels of interleukin (IL)-ß, IL-6 and tumor necrosis factor (TNF)-α and assessed the degree of fibrosis in rCFBs and hypertrophy in rCMCs. RESULTS: rMSCs induced SFRS3 expression and promoted cell cycle, proliferation, while reducing apoptosis of Ang II-treated rCFBs and rCMCs. Co-culture of rMSCs with these cells also repressed cytokine production and mitigated the fibrosis of rCFBs, as well as hypertrophy of rCMCs triggered by Ang II. Overexpression of SFRS3 in the rCFBs and rCMCs yielded identical effects to rMSC co-culture. CONCLUSION: MSCs may alleviate Ang II-induced cardiac fibrosis and cardiomyocyte hypertrophy by increasing SFRS3 expression in vitro.

A user-friendly machine learning approach for cardiac structures assessment.

Background: Machine learning is increasingly being used to diagnose and treat various diseases, including cardiovascular diseases. Automatic image analysis can expedite tissue analysis and save time. However, using machine learning is limited among researchers due to the requirement of technical expertise. By offering extensible features through plugins and scripts, machine-learning platforms make these techniques more accessible to researchers with limited programming knowledge. The misuse of anabolic-androgenic steroids is prevalent, particularly among athletes and bodybuilders, and there is strong evidence of their detrimental effects on ventricular myocardial capillaries and muscle cells. However, most studies rely on qualitative data, which can lead to bias and limited reliability. We present a user-friendly approach using machine learning algorithms to measure the effects of exercise and anabolic-androgenic steroids on cardiac ventricular capillaries and myocytes in an experimental animal model. Method: Male Wistar rats were divided into four groups (n = 28): control, exercise-only, anabolic-androgenic steroid-alone, and exercise with anabolic-androgenic steroid. Histopathological analysis of heart tissue was conducted, with images processed and analyzed using the Trainable Weka Segmentation plugin in Fiji software. Machine learning classifiers were trained to segment capillary and myocyte nuclei structures, enabling quantitative morphological measurements. Results: Exercise significantly increased capillary density compared to other groups. However, in the exercise + anabolic-androgenic steroid group, steroid use counteracted this effect. Anabolic-androgenic steroid alone did not significantly impact capillary density compared to the control group. Additionally, the exercise group had a significantly shorter intercapillary distance than all other groups. Again, using steroids in the exercise + anabolic-androgenic steroid group diminished this positive effect. Conclusion: Despite limited programming skills, researchers can use artificial intelligence techniques to investigate the adverse effects of anabolic steroids on the heart's vascular network and muscle cells. By employing accessible tools like machine learning algorithms and image processing software, histopathological images of capillary and myocyte structures in heart tissues can be analyzed.

Actn2 defects accelerates H9c2 hypertrophy via ERK phosphorylation under chronic stress.

BACKGROUND: In humans, ACTN2 mutations are identified as highly relevant to a range of cardiomyopathies such as DCM and HCM, while their association with sudden cardiac death has been observed in forensic cases. Although ACTN2 has been shown to regulate sarcomere Z-disc organization, a causal relationship between ACTN2 dysregulation and cardiomyopathies under chronic stress has not yet been investigated. OBJECTIVE: In this work, we explored the relationship between Actn2 dysregulation and cardiomyopathies under dexamethasone treatment. METHODS: Previous cases of ACTN2 mutations were collected and the conservative analysis was carried out by MEGA 11, the possible impact on the stability and function of ACTN2 affected by these mutations was predicted by Polyphen-2. ACTN2 was suppressed by siRNA in H9c2 cells under dexamethasone treatment to mimic the chronic stress in vitro. Then the cardiac hypertrophic molecular biomarkers were elevated, and the potential pathways were explored by transcriptome analysis. RESULTS: Actn2 suppression impaired calcium uptake and increased hypertrophy in H9c2 cells under dexamethasone treatment. Concomitantly, hypertrophic molecular biomarkers were also elevated in Actn2-suppressed cells. Further transcriptome analysis and Western blotting data suggested that Actn2 suppression led to the excessive activation of the MAPK pathway and ERK cascade. In vitro pharmaceutical intervention with ERK inhibitors could partially reverse the morphological changes and inhibit the excessive cardiac hypertrophic molecular biomarkers in H9c2 cells. CONCLUSION: Our study revealed a functional role of ACTN2 under chronic stress, loss of ACTN2 function accelerated H9c2 hypertrophy through ERK signaling. A commercial drug, Ibudilast, was identified to reverse cell hypertrophy in vitro.

The spectrum of cardiac abnormalities in patients with acromegaly: results from a case-control cardiac magnetic resonance study.

PURPOSE: Cardiac abnormalities are common in patients with acromegaly, contributing to the increased morbidity and mortality. Cardiac magnetic resonance (CMR) is the gold standard for measuring cardiac morpho-functional changes. This study aims to detect cardiac alterations in acromegaly through CMR, even when the disease is adequately controlled. METHODS: In this, multicentre, case-control study, we compared consecutive patients with acromegaly, cured after surgery or requiring medical treatment, with matched controls recruited among patients harbouring non-functioning adrenal incidentalomas. RESULTS: We included 20 patients with acromegaly (7 females, mean age 50 years) and 17 controls. Indexed left ventricular-end-diastolic volume (LV-EDVi) and LV-end-systolic volume (LV-ESVi) were higher in patients than in controls (p < 0.001), as were left ventricular mass (LVMi) (p = 0.001) and LV-stroke volume (LV-SVi) (p = 0.028). Right ventricle (RV) EDVi and ESVi were higher, whereas RV-ejection fraction (RV-EF) was lower (p = 0.002) in patients than in controls (p < 0.001). No significant differences were observed in the prevalence of cardiometabolic comorbidities, including hypertension, glucose and lipid metabolism impairment, obstructive sleep apnoea syndrome, and obesity. IGF1 x upper limit of normal significantly predicted LVMi (b = 0.575; p = 0.008). Subgroup analysis showed higher LVMi (p = 0.025) and interventricular septum thickness (p = 0.003) in male than female patients, even after adjusting cardiac parameters for confounding factors. CONCLUSIONS: The CMR analysis reveals a cluster of biventricular structural and functional impairment in acromegaly, even when the biochemical control if achieved. These findings appear specifically triggered by the exposure to GH-IGF1 excess and show sex-related differences advocating a possible interaction with sex hormones in cardiac disease progression.

miR-31-5p suppresses myocardial hypertrophy by targeting Nfatc2ip.

Cardiac hypertrophy, worldwide known as an adaptive functional compensatory state of myocardial stress, is mainly believed to proceed to severe heart diseases, even to sudden death. Emerging studies have explored the microRNA alteration during hypertrophy. However, the mechanisms of microRNAs involved in cardiac hypertrophy are still uncertain. We studied young rats to establish abdominal aorta coarctation (AAC) for 4 weeks. With the significant downregulated cardiac function and upregulated hypertrophic biomarkers, AAC-induced rats showed enlarged myocardiocytes and alterations in microRNAs, especially downregulated miR-31-5p. miR-31-5p targets the 3'UTR of Nfatc2ip and inhibits myocardial hypertrophy in vitro and in vivo. Furthermore, we verified that Nfatc2ip is necessary and sufficient for cardiac hypertrophy in neonatal rat cardiomyocytes. Moreover, we found miR-31-5p inhibited the colocalization of Nfatc2ip and hypertrophic gene ß-Mhc. Luciferase assay and ChiP-qPCR test demonstrated that Nfatc2ip binded to the core-promoter of ß-Mhc and enhanced its transcriptional activity. Above all, our study found a new pathway, mir-31-5p/Nfatc2ip/ß-Mhc, which is involved in cardiac hypertrophy, suggesting a potential target for intervention of cardiac hypertrophy.

Effect of electroacupuncture on myocardial transient receptor potential channels in mice with myocardial hypertrophy. / ç”µé’ˆå¯¹å¿ƒè‚Œè‚¥åŽšå°é¼ å¿ƒè‚Œç»„ç»‡çž¬æ—¶å—ä½“ç”µä½é€šé“çš„å½±å“.

OBJECTIVES: To observe the effect of electroacupuncture (EA) at "Neiguan"(PC6) on cardiac function, cardiac morphology and transient receptor potential channel (TRPC) protein expressions in myocardial tissue of mice with myocardial hypertrophy, so as to explore its mechanisms underlying improvement of myocardial hypertrophy. METHODS: Forty-five male C57BL/6 mice were randomly divided into control, model and EA groups (15 mice/group). The myocardial hypertrophy model was established by subcutaneous injection of isoproterenol hydrochloride (15 mg·kg-1·d-1) for 14 days. The mice of the control group received subcutaneous injection of same amount of normal saline. The mice of the EA group received EA stimulation (frequency of 2 Hz, intensity of 1 mA) of bilateral PC6 for 20 min each time, once a day for 14 consecutive days. After the intervention, the body weight, tibia length and heart weight were measured. The left ventricular ejection fraction (EF), fractional shortening index (FS), left ventricular end-systolic volume (LVEV), left ventricular end-systolic internal diameter (LVID) and left ventricular posterior wall thickness (LVPW) were measured by using echocardiography for evaluating the cardiac function. The mean number and surface area of myocardial cells was detected by wheat germ agglutinin (WGA) staining, and changes of the cardiac morphology were observed under light microscopy after HE staining. The expression levels of TRPC1, TRPC3, TRPC4 and TRPC6 (TRPC1/3/4/6) in the myocardial tissue were detected by real-time quantitative PCR (qPCR) and Western blot, separately. RESULTS: Compared with the control group, the heart-body weight ratio(P<0.05) and heart-weight-to-tibia-length ratio (P<0.01), LVEV and LVID levels, the relative surface area, left ventricular area ratio, and the expression levels of cardiac TRPC1/3/4/6 were significantly increased (P<0.01, P<0.05), while the EF, FS, LVPW, number of cardiomyocytes, and the left ventricular posterior wall ratio were obviously decreased (P<0.01, P<0.05) in the model group. In comparison with the model group, the heart/body weight ratio, heart-weight-to-tibia-length ratio, LVEV and LVID levels, relative surface area, left ventricular area ratio, and the expression levels of cardiac TRPC1/3/4/6 were significantly decreased (P<0.01, P<0.05), while the EF, FS, LVPW, number of cardiomyocytes and left ventricular posterior wall ratio were significantly increased (P<0.01, P<0.05) in the EA group. H.E. staining showed disordered arrangement of cardiomyocytes and obvious myocardial interstitial inflammatory cell infiltration in the model group, and evident reduction of degree of cardiac fibrosis and interstitial edema in the EA group. CONCLUSIONS: EA of PC6 can improve the cardiac function and cardiac morphology in mice with myocardial hypertrophy, which may be related to its functions in down-regulating the expression of transient receptor potential channels.

Hypoxia-Induced Myocardial Hypertrophy Companies with Apoptosis Enhancement and p38-MAPK Pathway Activation.

Li, Xiaoxu, Zhijun Pu, Gang Xu, Yidong Yang, Yu Cui, Xiaoying Zhou, Chenyuan Wang, Zhifeng Zhong, Simin Zhou, Jun Yin, Fabo Shan, Chengzhong Yang, Li Jiao, Dewei Chen, and Jian Huang. Hypoxia-induced myocardial hypertrophy companies with apoptosis enhancement and p38-MAPK pathway activation. High Alt Med Biol. 25:186-196, 2024. Background: Right ventricular function and remodeling are closely associated with symptom severity and patient survival in hypoxic pulmonary hypertension. However, the detailed molecular mechanisms underlying hypoxia-induced myocardial hypertrophy remain unclear. Methods: In Sprague-Dawley rats, hemodynamics were assessed under both normoxia and hypobaric hypoxia at intervals of 7 (H7), 14 (H14), and 28 (H28) days. Morphological changes in myocardial tissue were examined using hematoxylin and eosin (HE) staining, while myocardial hypertrophy was evaluated with wheat germ agglutinin (WGA) staining. Apoptosis was determined through TUNEL assays. To further understand the mechanism of myocardial hypertrophy, RNA sequencing was conducted, with findings validated via Western blot analysis. Results: The study demonstrated increased hypoxic pulmonary hypertension and improved right ventricular diastolic and systolic function in the rat models. Significant elevations in pulmonary arterial systolic pressure (PASP), mean pulmonary arterial pressure (mPAP), right ventricular mean pressure (RVMP), and the absolute value of +dp/dtmax were observed in the H14 and H28 groups compared with controls. In addition, right ventricular systolic pressure (RVSP), -dp/dtmax, and the mean dp/dt during isovolumetric relaxation period were notably higher in the H28 group. Heart rate increased in the H14 group, whereas the time constant of right ventricular isovolumic relaxation (tau) was reduced in both H14 and H28 groups. Both the right heart hypertrophy index and the heart weight/body weight ratio (HW/BW) were elevated in the H14 and H28 groups. Myocardial cell cross-sectional area also increased, as shown by HE and WGA staining. Western blot results revealed upregulated HIF-1α levels and enhanced HIF-2α expression in the H7 group. In addition, phosphorylation of p38 and c-fos was augmented in the H28 group. The H28 group showed elevated levels of Cytochrome C (Cyto C), whereas the H14 and H28 groups exhibited increased levels of Cleaved Caspase-3 and the Bax/Bcl-2 ratio. TUNEL analysis revealed a rise in apoptosis with the extension of hypoxia duration in the right ventricle. Conclusions: The study established a link between apoptosis and p38-MAPK pathway activation in hypoxia-induced myocardial hypertrophy, suggesting their significant roles in this pathological process.

Association of cardiovascular risk factors and myocardial hypertrophy in women with preeclampsia history.

AIMS: A historic of preeclampsia (PE) has been associated with cardiovascular disease (CVD) in women. There are substantial evidences that cardiovascular changes resulting from PE can persist even after pregnancy end. Therefore, the aims was to evaluate the prevalence of myocardial hypertrophy in young women 12 months after PE event as well as try to identify risk factors for these changes. MATERIALS AND METHODS: Single-center observational prospective cross-sectional study that included 118 consecutive patients after 12 months of PE. Clinical and laboratory evaluations, echocardiogram were performed. Myocardial hypertrophy (LVH) was defined as an index myocardial mass ≥ 45 g/m2.7, for women. Classical risk factors for CVD were considered. Analysis included linear or logistic regression and Spearman's correlation coefficient. Significance level of 5 %. KEY FINDINGS: Systemic arterial hypertension (SAH) was identified in 52 patients (44 %), overweight/obesity (OOB) in 82 (69 %), dyslipidemia in 68 (57 %) and metabolic syndrome in 47 patients (40 %). LVH was present in 35 cases (29 %) and associated with OOB (OR = 4.51; CI95%:1.18-17.17, p < 0.001), in a model corrected for age and SAH diagnosis. When only the metabolic syndrome components were analyzed, in the multiple logistic regression model, the abdominal circumference was the only clinical variable associated with LVH (OR = 17.65; CI95%:3.70-84.17; p < 0.001). SIGNIFICANCE: It was observed a high prevalence of ventricular hypertrophy in young women with a history of pre-eclampsia. This condition was associated with the presence of obesity.

Combined Pharmacological Modulation of Translational and Transcriptional Activity Signaling Pathways as a Promising Therapeutic Approach in Children with Myocardial Changes.

Myocardial hypertrophy is the most common condition that accompanies heart development in children. Transcriptional gene expression regulating pathways play a critical role both in cardiac embryogenesis and in the pathogenesis of congenital hypertrophic cardiomyopathy, neonatal posthypoxic myocardial hypertrophy, and congenital heart diseases. This paper describes the state of cardiac gene expression and potential pharmacological modulators at different transcriptional levels. An experimental model of perinatal cardiac hypoxia showed the downregulated expression of genes responsible for cardiac muscle integrity and overexpressed genes associated with energy metabolism and apoptosis, which may provide a basis for a therapeutic approach. Current evidence suggests that RNA drugs, theaflavin, neuraminidase, proton pumps, and histone deacetylase inhibitors are promising pharmacological agents in progressive cardiac hypertrophy. The different points of application of the above drugs make combined use possible, potentiating the effects of inhibition in specific signaling pathways. The special role of N-acetyl cysteine in both the inhibition of several signaling pathways and the reduction of oxidative stress was emphasized.

Effect and mechanism of gomisin D on the isoproterenol induced myocardial injury in H9C2 cells and mice.

We established myocardial injury models in vivo and in vitro to investigate the cardioprotective effect of gomisin D obtained from Schisandra chinensis. Gomisin D significantly inhibited isoproterenol-induced apoptosis and hypertrophy in H9C2 cells. Gomisin D decreased serum BNP, ANP, CK-MB, cTn-T levels and histopathological alterations, and inhibited myocardial hypertrophy in mice. In mechanisms research, gomisin D reversed ISO-induced accumulation of intracellular ROS and Ca2+. Gomisin D further improved mitochondrial energy metabolism disorders by regulating the TCA cycle. These results demonstrated that gomisin D had a significant effect on isoproterenol-induced myocardial injury by inhibiting oxidative stress, calcium overload and improving mitochondrial energy metabolism.

Structure-based design of non-hypertrophic apelin receptor modulator.

Apelin is a key hormone in cardiovascular homeostasis that activates the apelin receptor (APLNR), which is regarded as a promising therapeutic target for cardiovascular disease. However, adverse effects through the ß-arrestin pathway limit its pharmacological use. Here, we report cryoelectron microscopy (cryo-EM) structures of APLNR-Gi1 complexes bound to three agonists with divergent signaling profiles. Combined with functional assays, we have identified "twin hotspots" in APLNR as key determinants for signaling bias, guiding the rational design of two exclusive G-protein-biased agonists WN353 and WN561. Cryo-EM structures of WN353- and WN561-stimulated APLNR-G protein complexes further confirm that the designed ligands adopt the desired poses. Pathophysiological experiments have provided evidence that WN561 demonstrates superior therapeutic effects against cardiac hypertrophy and reduced adverse effects compared with the established APLNR agonists. In summary, our designed APLNR modulator may facilitate the development of next-generation cardiovascular medications.

Connexin43, A Promising Target to Reduce Cardiac Arrhythmia Burden in Pulmonary Arterial Hypertension.

While essential hypertension (HTN) is very prevalent, pulmonary arterial hypertension (PAH) is very rare in the general population. However, due to progressive heart failure, prognoses and survival rates are much worse in PAH. Patients with PAH are at a higher risk of developing supraventricular arrhythmias and malignant ventricular arrhythmias. The latter underlie sudden cardiac death regardless of the mechanical cardiac dysfunction. Systemic chronic inflammation and oxidative stress are causal factors that increase the risk of the occurrence of cardiac arrhythmias in hypertension. These stressful factors contribute to endothelial dysfunction and arterial pressure overload, resulting in the development of cardiac pro-arrhythmic conditions, including myocardial structural, ion channel and connexin43 (Cx43) channel remodeling and their dysfunction. Myocardial fibrosis appears to be a crucial proarrhythmic substrate linked with myocardial electrical instability due to the downregulation and abnormal topology of electrical coupling protein Cx43. Furthermore, these conditions promote ventricular mechanical dysfunction and heart failure. The treatment algorithm in HTN is superior to PAH, likely due to the paucity of comprehensive pathomechanisms and causal factors for a multitargeted approach in PAH. The intention of this review is to provide information regarding the role of Cx43 in the development of cardiac arrhythmias in hypertensive heart disease. Furthermore, information on the progress of therapy in terms of its cardioprotective and potentially antiarrhythmic effects is included. Specifically, the benefits of sodium glucose co-transporter inhibitors (SGLT2i), as well as sotatercept, pirfenidone, ranolazine, nintedanib, mirabegron and melatonin are discussed. Discovering novel therapeutic and antiarrhythmic strategies may be challenging for further research. Undoubtedly, such research should include protection of the heart from inflammation and oxidative stress, as these are primary pro-arrhythmic factors that jeopardize cardiac Cx43 homeostasis, the integrity of intercalated disk and extracellular matrix, and, thereby, heart function.

The Role and Mechanism of STIM1/Orai1-Regulated Ca2+ Influx in Myocardial Hypertrophy in Type 2 Diabetes Mellitus.

OBJECTIVE: Diabetic cardiomyopathy (DCM) is the most common cardiovascular complication of type 2 diabetes mellitus (T2DM). Patients affected with DCM face a notably higher risk of progressing to congestive heart failure compared to other populations. Myocardial hypertrophy, a clearly confirmed pathological change in DCM, plays an important role in the development of DCM, with abnormal Ca2+ homeostasis serving as the key signal to induce myocardial hypertrophy. Therefore, investigating the mechanism of Ca2+ transport is of great significance for the prevention and treatment of myocardial hypertrophy in T2DM. METHODS: The rats included in the experiment were divided into wild type (WT) group and T2DM group. The T2DM rat model was established by feeding the rats with high-fat and high-sugar diets for three months combined with low dose of streptozotocin (100mg/kg). Afterwards, primary rat cardiomyocytes were isolated and cultured, and cardiomyocyte hypertrophy was induced through high-glucose treatment. Subsequently, mechanistic investigations were carried out through transfection with si-STIM1 and oe-STIM1. Western blot (WB) was used to detect the expression of the STIM1, Orai1 and p-CaMKII. qRT-PCR was used to detect mRNA levels of myocardial hypertrophy marker proteins. Cell surface area was detected using TRITC-Phalloidin staining, and intracellular Ca2+ concentration in cardiomyocytes was measured using Fluo-4 fluorescence staining. RESULTS: Through animal experiments, an upregulation of Orai1 and STIM1 was revealed in the rat model of myocardial hypertrophy induced by T2DM. Meanwhile, through cell experiments, it was found that in high glucose (HG)-induced hypertrophic cardiomyocytes, the expression of STIM1, Orai1, and p-CaMKII was upregulated, along with increased levels of store-operated Ca2+ entry (SOCE) and abnormal Ca2+ homeostasis. However, when STIM1 was downregulated in HG-induced cardiomyocytes, SOCE levels decreased and p-CaMKII was downregulated, resulting in an improvement in myocardial hypertrophy. To further elucidate the mechanism of action involving SOCE and CaMKII in T2DM-induced myocardial hypertrophy, high-glucose cardiomyocytes were respectively treated with BTP2 (SOCE blocker) and KN-93 (CaMKII inhibitor), and the results showed that STIM1 can mediate SOCE, thereby affecting the phosphorylation level of CaMKII and improving cardiomyocyte hypertrophy. CONCLUSION: STIM1/Orai1-mediated SOCE regulates p-CaMKII levels, thereby inducing myocardial hypertrophy in T2DM.

Role and molecular mechanisms of SGLT2 inhibitors in pathological cardiac remodeling (Review).

Cardiovascular diseases are caused by pathological cardiac remodeling, which involves fibrosis, inflammation and cell dysfunction. This includes autophagy, apoptosis, oxidative stress, mitochondrial dysfunction, changes in energy metabolism, angiogenesis and dysregulation of signaling pathways. These changes in heart structure and/or function ultimately result in heart failure. In an effort to prevent this, multiple cardiovascular outcome trials have demonstrated the cardiac benefits of sodium­glucose cotransporter type 2 inhibitors (SGLT2is), hypoglycemic drugs initially designed to treat type 2 diabetes mellitus. SGLT2is include empagliflozin and dapagliflozin, which are listed as guideline drugs in the 2021 European Guidelines for Heart Failure and the 2022 American Heart Association/American College of Cardiology/Heart Failure Society of America Guidelines for Heart Failure Management. In recent years, multiple studies using animal models have explored the mechanisms by which SGLT2is prevent cardiac remodeling. This article reviews the role of SGLT2is in cardiac remodeling induced by different etiologies to provide a guideline for further evaluation of the mechanisms underlying the inhibition of pathological cardiac remodeling by SGLT2is, as well as the development of novel drug targets.

Case report: Systemic lupus erythematosus combined with myocardial hypertrophy.

OBJECTIVE: Systemic lupus erythematosus (SLE) is a multisystem-involved, highly heterogeneous autoimmune disease with diverse clinical manifestations. We report an extremely rare case of SLE with severe diffuse myocardial hypertrophy. METHODS: The patient's echocardiography and cardiac magnetic resonance imaging (CMR) results indicated diffuse myocardial hypertrophy. After excluding coronary atherosclerosis, hypertensive cardiomyopathy, drug toxicity, and other causes, the patient was diagnosed with SLE-specific cardiomyopathy. Medications such as hormones, antimalarials, immunosuppressants, and biologics were administered. RESULTS: Ancillary test results were as follows: hs-cTnI: 0.054 ng/mL (0-0.016); NTproBNP: 1594.0 pg/mL (<150); A contrast-enhanced CMR revealed the diffuse thickening of the left ventricular wall with multiple abnormal enhancements, reduced left ventricular systolic and diastolic function, and moderate amount of pericardial effusion. Endomyocardial myocardial biopsy was performed, showing cardiomyocyte hypertrophy and degeneration, and no changes in myocarditis or amyloidosis. The pathology viewed by electron microscopy showed increased intracellular glycogen in the myocardium, and no hydroxychloroquine-associated damage in the myocardium. The 24-h ambulatory blood pressure and contrast-enhanced computed tomography of coronary arteries were normal. The diagnosis of SLE-specific cardiomyopathy was clear. The myocardial hypertrophy showed reversible alleviation following treatment with high-dose corticosteroids. CMR results before and after treatment were as follows: interventricular septum, pretreatment (28) versus post-treatment (22) mm; left ventricular inferior wall, pretreatment (18-21) versus post-treatment (12-14) mm; left ventricular lateral wall, pretreatment (17-18) versus post-treatment (10-12) mm; pericardial effusion (left ventricular lateral wall), pretreatment (25) versus post-treatment (12) mm; left ventricular ejection fraction, pretreatment (38.9%) versus post-treatment (66%). CONCLUSION: Myocardial hypertrophy may be an important sign of active and prognostic assessment in SLE diagnosis and management. Similarly, when encountering cases of myocardial hypertrophy, the possibility of autoimmune disease should be considered in addition to common causes.