SGLT2 inhibitor dapagliflozin reduces endothelial dysfunction and microvascular damage during cardiac ischemia/reperfusion injury through normalizing the XO-SERCA2-CaMKII-coffilin pathways

Exploring the effect of dapagliflozin on coronary inflammation in type 2 diabetes patients based on the coronary artery perivascular fat attenuation index

BACKGROUND

The pericoronary fat attenuation index (FAI) is a novel biomarker that serves as an indicator of coronary artery inflammation. Dapagliflozin has become an important component of standard treatment for type 2 diabetes because of its cardioprotective and renoprotective effects. The objective of this research was to explore how dapagliflozin impacts coronary artery inflammation in T2DM patients and to establish a novel theoretical framework for the protective role of dapagliflozin in the cardiovascular system.

METHODS

This research retrospectively included 271 T2DM patients treated with coronary computed tomography angiography (CCTA) at Hebei Provincial People's Hospital from January 2021 to November 2024, with 103 patients receiving dapagliflozin therapy (dapagliflozin+) and 168 patients not receiving dapagliflozin (dapagliflozin-) (oral dapagliflozin 10 mg/day for no less than 6 months). Baseline clinical information, laboratory markers, and CCTA-related metrics were collected and analysed across both groups. The relationship between dapagliflozin treatment and the pericoronary FAI was analysed using multiple linear regression to control for confounding variables, and the correlation between the two variables was further examined across various subgroups.

RESULTS

Compared with those in the dapagliflozin- group, the patients in the dapagliflozin+ group were younger (P<0.001), and the proportion of men was higher (P<0.05). There were no between-group differences in the baseline data, such as diabetes course, BMI, and blood lipid status (P>0.05). The FAI of the LAD and RCA in the dapagliflozin+ group was lower than that in the other groups, and the average FAI of the three coronary arteries was also significantly lower, while there was no significant difference in the LCX (LAD: dapagliflozin- group: -85.50 (-90.43, -78.27)，dapagliflozin+ group：-86.94 (-92.81, -81.57)，P= 0.044；RCA：dapagliflozin- group：-86.31 (-92.12, -80.09), dapagliflozin+ group：-88.79 (-94.59, -83.31), P= 0.019; Mean: dapagliflozin- group: -84.05 (-87.73, -77.45), dapagliflozin+ group: -84.88 (-89.82, -79.67), P= 0.022; LCX: dapagliflozin- group：-77.81 (-82.57, -71.75), dapagliflozin+ group: -78.25 (-84.56, -72.15), P = 0.260). Multiple linear regression analyses revealed an independent association between dapagliflozin treatment and a decreased in FAI in the LAD and RCA (LAD: β=-2.449; RCA: β=-3.897; P values are all less than 0.05). This association was different across various subsets of T2DM patients.

CONCLUSION

Dapagliflozin treatment is associated with a significant reduction in coronary artery inflammation in T2DM patients, which may partly explain its beneficial effects on reducing cardiovascular risk.

Cardiac Fibrosis: Mechanistic Discoveries Linked to SGLT2 Inhibitors

Sodium-glucose cotransporter 2 inhibitors (SGLT2is), commonly known as flozins, have garnered attention not only for their glucose-lowering effects in type 2 diabetes mellitus (T2DM) but also for their cardioprotective properties. This review examines the mechanisms underlying the anti-fibrotic effects of SGLT2is, with a focus on key clinical trials and preclinical models. SGLT2is, mainly empagliflozin and dapagliflozin, have demonstrated significant reductions in heart failure-related hospitalizations, cardiovascular death, and fibrosis markers, independent of their glucose-lowering effects. The cardioprotective benefits appear to stem from direct actions on cardiac tissues, modulation of inflammatory responses, and improvements in metabolic parameters. In animal models of heart failure, SGLT2is were demonstrated to reduce cardiac fibrosis through mechanisms involving AMPK activation, reduced oxidative stress, and inhibition of pro-fibrotic pathways, not only through the inhibition of SGLT2 present on cardiac cells but also by targeting several other molecular targets. These findings confirm their efficacy in the treatment of heart failure and align with evidence from human trials, supporting the potential involvement of multiple pathways in mediating cardiac fibrosis. These results also provide a promising basis for clinical trials specifically targeting pathways shared with SGLT2is.

Microvascular Dysfunction Following Cardioplegic Arrest and Cardiopulmonary Bypass: Impacts of Diabetes and Hypertension

Cardioplegic arrest and cardiopulmonary bypass (CP/CPB) are known to engender microvascular dysfunction in patients undergoing cardiac surgery. These effects are significantly varied by patient comorbidities including diabetes and hypertension. Both diabetes and hypertension are associated with worse outcomes after cardiac surgery, partly related to increased microvascular complications. In this review, we examine several key facets of microvascular dysfunction after CP/CPB: microvascular endothelial and vasomotor dysfunction, altered gene and protein expression, endothelial adherens junction dysfunction, and programmed cell death as they relate to diabetes and hypertension. This review examines both classical techniques, including microvessel reactivity assays, and modern multiomic approaches to characterizing these microvascular changes.

Impact of sodium-glucose cotransporter-2 inhibitors on pulmonary vascular cell function and arterial remodeling

Sodium-glucose cotransporter-2 (SGLT-2) inhibitors represent a cutting-edge class of oral antidiabetic therapeutics that operate through selective inhibition of glucose reabsorption in proximal renal tubules, consequently augmenting urinary glucose excretion and attenuating blood glucose levels. Extensive clinical investigations have demonstrated their profound cardiovascular efficacy. Parallel basic science research has elucidated the mechanistic pathways through which diverse SGLT-2 inhibitors beneficially modulate pulmonary vascular cells and arterial remodeling. Specifically, these inhibitors exhibit promising potential in enhancing pulmonary vascular endothelial cell function, suppressing pulmonary smooth muscle cell proliferation and migration, reversing pulmonary arterial remodeling, and maintaining hemodynamic equilibrium. This comprehensive review synthesizes current literature to delineate the mechanisms by which SGLT-2 inhibitors enhance pulmonary vascular cell function and reverse pulmonary remodeling, thereby offering novel therapeutic perspectives for pulmonary vascular diseases.

Empagliflozin prevents TNF-α induced endothelial dysfunction under flow -the potential involvement of calcium and sodium-hydrogen exchanger

BACKGROUND

Empagliflozin (EMPA) attenuates inflammation-induced ROS generation in static endothelial cells through inhibition of sodium hydrogen exchanger 1 (NHE1) and modulation of ion homeostasis. We hypothesize that EMPA will alleviate TNF-α stimulated endothelial dysfunction under flow conditions, and that this might be mediated by NHE1 and intracellular Ca2+.

METHODS

Human coronary artery endothelial cells were pre-treated with EMPA or vehicle before starting flow with or without TNF-α. Intracellular Ca2+ was recorded for 5 min at the start of flow. ROS generation and NO bioavailability, Piezo-1, cytokines, adhesion molecules, VE-cadherin and eNOS were detected after 6 h. BAPTA-AM was applied to chelate intracellular Ca2+ and NHE1 was knocked down with specific siRNA.

RESULTS

Under flow conditions, EMPA inhibited ROS production and [Ca2+] increase in cells exposed to TNF-α (P < 0.05). BAPTA-AM and NHE1 knockdown both reduced ROS generation (P < 0.05), and genetical inhibition of NHE1 led to reduction of intracellular [Ca2+] in HCAECs receiving TNF-α (P < 0.05). Yet, EMPA showed no effect on the increased cytokine production, adhesion molecule expression and phosphorylation of eNOS in endothelial cells exposed to TNF-α.

CONCLUSION

EMPA mitigates increased ROS production and impaired NO bioavailability in TNF-α stimulated cells under flow. The anti-oxidative effect of EMPA is mediated by the decreased intracellular [Ca2+] following NHE1 inhibition.

Central SGLT2 mediate sympathoexcitation in hypertensive heart failure via attenuating subfornical organ endothelial cGAS ubiquitination to amplify neuroinflammation: Molecular mechanism behind sympatholytic effect of Empagliflozin

BACKGROUND

Sodium/glucose co-transporter 2 (SGLT2) inhibitors have transformed heart failure (HF) treatment, offering sympatholytic effects whose mechanisms are not fully understood. Our previous studies identified Cyclic GMP-AMP synthase (cGAS)-derived neuroinflammation in the Subfornical organ (SFO) as a promoter of sympathoexcitation, worsening myocardial remodeling in HF. This research explored the role of central SGLT2 in inducing endothelial cGAS-driven neuroinflammation in the SFO during HF and assessed the impact of SGLT2 inhibitors on this process.

METHODS

Hypertensive HF was induced in mice via Angiotensin II infusion for four weeks. SGLT2 expression and localization in the SFO were determined through immunoblotting and double-immunofluorescence staining. AAV9-TIE-shRNA (SGLT2) facilitated targeted SGLT2 knockdown in SFO endothelial cells (ECs), with subsequent analyses via immunoblotting, staining, and co-immunoprecipitation to investigate interactions with cGAS, mitochondrial alterations, and pro-inflammatory pathway activation. Renal sympathetic nerve activity and heart rate variability were measured to assess sympathetic output, alongside evaluations of cardiac function in HF mice.

RESULTS

In HF model mice, SGLT2 levels are markedly raised in SFO ECs, disrupting mitochondrial function and elevating oxidative stress. SGLT2 knockdown preserved mitochondrial integrity and function, reduced inflammation, and highlighted the influence of SGLT2 on mitochondrial health. SGLT2's interaction with cGAS prevented its ubiquitination and degradation, amplifying neuroinflammation and HF progression. Conversely, Empagliflozin counteracted these effects, suggesting that targeting the SGLT2-cGAS interaction as a novel HF treatment avenue.

CONCLUSION

This study revealed that SGLT2 directly reduced cGAS degradation in brain ECs, enhancing neuroinflammation in the SFO, and promoting sympathoexcitation and myocardial remodeling. The significance of the central SGLT2-cGAS interaction in cardiovascular disease mechanisms is emphasized.

Energy Metabolism Dysregulation in Myocardial Infarction: An Integrative Analysis of Ischemic Cardiomyopathy

BACKGROUND

Myocardial metabolism is closely related to functional changes after myocardial infarction (MI).

OBJECTIVE

This study aimed to present an integrative examination of human ischemic cardiomyopathy.

METHODS

We used both GSE121893 single-cell suspension sequencing and GSE19303 transcription microarray data sets from the GEO database, along with a murine MI model for full-spectrum metabolite detection. Through a systematic investigation that involved differential metabolite identification and functional enrichment analysis, we shed light on the pivotal role of energy metabolism dysregulation in the progression of MI.

RESULTS

Our findings revealed an association between the core regulatory genes CDKN1A, FOS, ITGB4, and MAP2K1 and the underlying pathophysiology of the disease. These genes are identified as critical elements in the complex landscape of myocardial ischemic disorder, highlighting novel insights into therapeutic targets and the intricate biological mechanisms involved.

CONCLUSION

This analysis provides a framework for future research on the metabolic alterations associated with MI.

The Effect of Dapagliflozin on Heart Function in Animal Models of Cardiac Ischemia, A Systematic Review and Meta-analysis

INTRODUCTION

In this study, a meta-analysis was conducted to investigate the therapeutic effect of Dapagliflozin (DAPA) on animals suffering from myocardial ischemia reperfusion compared to the group that did not receive treatment.

METHODS

According to the inclusion and exclusion criteria two researchers performed the primary and secondary screening based on the title abstract and full text. After data extraction, meta-analysis was performed using STATA software. Standardized mean differences were used to analyze the results of the reported studies. Subgroup analysis and quality control of articles were also conducted.

RESULTS

A total of 21 separate experiments showed that DAPA increased mean fractional shortening (%FS) and ejection fraction (%EF) compared to the untreated animals. A significant reduction in the weight and size of the infarcted area and significant increases in dp/dt+, dp/dt-, left ventricular end-systolic internal dimensions (LVIDs), left ventricular end-diastolic internal dimensions (LVIDd), Volume systole and Volume diastole were observed in treated animals.

CONCLUSION

DAPA has the potential to become a candidate for the treatment of post-ischemic heart damage, pending animal and human studies to validate this.

Intra-myocardial hemorrhage and cardiac microvascular injury in ischemia/reperfusion. A systematic review of current evidences

The in-hospital mortality rate in acute myocardial infarction (AMI) remains high despite the undoubted achievements in treatment of this disease achieved in the last 40 years. The dangerous complications of AMI remain cardiac microvascular injury (CMI) and intramyocardial hemorrhage (IMH). IMH is a widespread pathology that occurs in 42 - 57% of patients with ST-segment elevation myocardial infarction and percutaneous coronary intervention. IMH is associated with larger infarct size and contractile dysfunction. IMH is accompanied by inflammation. The appearance of IMH is depending on the duration of ischemia and requires reperfusion of the heart. IMH is accompanied by contractile dysfunction and adverse remodeling of the heart. The most likely cause of IMH is CMI. Pretreatment with ATL-146e, melatonin, tanshinone IIA, relaxin, empagliflozin, dapagliflozin, and astragaloside IV can mitigate I/R-induced CMI. CMI is accompanied by an increase in the myocardial and plasma proinflammatory cytokine levels and also the downregulation of tight junction proteins in cardiac vascular endothelial cells. However, there is no convincing evidence that proinflammatory cytokines trigger CMI. An increase in the proinflammatory cytokine levels and CMI could be two independent processes.

9-PAHSA ameliorates microvascular damage during cardiac ischaemia/reperfusion injury by promoting LKB1/AMPK/ULK1-mediated autophagy-dependent STING degradation

BACKGROUND

Considering that cardiac microvascular injury may play a more critical role than cardiomyocyte injury in the pathology of early ischaemia/reperfusion (I/R) injury, therapeutic strategies targeting the microvasculature are highly desirable. Palmitic acid-9-hydroxystearic acid (9-PAHSA) is a new class of bioactive anti-inflammatory lipids widely distributed in vegetables, fruits and medicinal plants, especially broccoli and apple. However, the pharmacological effects and underlying mechanisms of 9-PAHSA in protecting- against cardiac microvascular I/R injury have rarely been studied.

PURPOSE

This study aimed to explore the potential effects and molecular mechanisms of 9-PAHSA on the coronary microvasculature after cardiac I/R injury.

METHODS

Immunofluorescence staining, western blotting, and other experimental methods were used to evaluate the role and mechanism of 9-PAHSA in cardiac microvascular I/R injury in vivo and in vitro.

RESULTS

9-PAHSA administration significantly attenuated myocardial I/R-induced microvascular damage, as indicated by an impaired microvascular structure, reduced regional blood perfusion and decreased endothelial barrier function. In addition, 9-PAHSA administration protected the structure and function of coronary artery endothelial cells (CMECs) to resist I/R damage, an effect that was at least partially mediated by increased autophagy. Mechanistically, 9-PAHSA activated autophagy through the LKB1/AMPK/ULK1 pathway and promoted STING degradation via the autophagic‒lysosomal pathway.

CONCLUSIONS

To our best knowledge, this study is the first to report that 9-PAHSA attenuates cardiac microvascular I/R injury, potentially by activating LKB1/AMPK/ULK1-mediated autophagy-dependent STING degradation to suppress apoptosis. Thus, 9-PAHSA may be a promising therapeutic option for alleviating cardiac microvascular I/R injury.

Prolonged Cardiopulmonary Bypass Time-Induced Endothelial Dysfunction via Glypican-1 Shedding, Inflammation, and Matrix Metalloproteinase 9 in Patients Undergoing Cardiac Surgery

OBJECTIVES

A prolonged cardiopulmonary bypass (CPB) time of over 180 min is linked to poorer outcomes and higher mortality in cardiac surgery. This study examines how glypican-1 shedding, matrix metallopeptidase 9 (MMP9), and the pro-inflammatory cytokine IL-1β may contribute to endothelial dysfunction in patients undergoing on-pump surgery with an extended CPB.

METHODS

Fifty-one patients undergoing cardiac surgical procedures were divided into two groups based on the intraoperative CPB duration: (i) normal CPB (<180 min, n = 23) and (ii) prolonged CPB (>180 min, n = 28). The preoperative, intraoperative, and postoperative plasma levels of glypican-1, MMP9, and IL-1β were measured.

RESULTS

Before surgery, the plasma levels of glypican-1, MMP9, and IL-1β were comparable between the normal CPB and the prolonged CPB groups. However, after the end of the CPB, all three markers showed significant elevation in the prolonged CPB group compared to the normal CPB group. Significant correlations were observed between the intraoperative and postoperative levels of MMP9, IL-1β, and glypican-1. A strong positive correlation was also observed between the intraoperative and postoperative levels of glypican-1 and the duration of the CPB.

CONCLUSIONS

A prolonged CPB triggers a systemic inflammatory response and activates MMP9, leading to glypican-1 shedding and endothelial dysfunction.

Exogenous Ketones in Cardiovascular Disease and Diabetes: From Bench to Bedside

Ketone bodies are molecules produced from fatty acids in the liver that act as energy carriers to peripheral tissues when glucose levels are low. Carbohydrate- and calorie-restricted diets, known to increase the levels of circulating ketone bodies, have attracted significant attention in recent years due to their potential health benefits in several diseases. Specifically, increasing ketones through dietary modulation has been reported to be beneficial for cardiovascular health and to improve glucose homeostasis and insulin resistance. Interestingly, although excessive production of ketones may lead to life-threatening ketoacidosis in diabetic patients, mounting evidence suggests that modest levels of ketones play adaptive and beneficial roles in pancreatic beta cells, although the exact mechanisms are still unknown. Of note, Sodium-Glucose Transporter 2 (SGLT2) inhibitors have been shown to increase the levels of beta-hydroxybutyrate (BHB), the most abundant ketone circulating in the human body, which may play a pivotal role in mediating some of their protective effects in cardiovascular health and diabetes. This systematic review provides a comprehensive overview of the scientific literature and presents an analysis of the effects of ketone bodies on cardiovascular pathophysiology and pancreatic beta cell function. The evidence from both preclinical and clinical studies indicates that exogenous ketones may have significant beneficial effects on both cardiomyocytes and pancreatic beta cells, making them intriguing candidates for potential cardioprotective therapies and to preserve beta cell function in patients with diabetes.

Effect of sodium glucose cotransporter 2 inhibitors on all cause death and rehospitalization for heart failure in patients with acute myocardial infarction

The impact of sodium-glucose co-transporter 2 inhibitors (SGLT2-i) on reducing the risk of all-cause mortality and rehospitalization for heart failure (HF) in patients with acute myocardial infarction (AMI) remains unclear. This study aims to evaluate the effect of SGLT2-i on all-cause mortality and rehospitalization for HF in patients diagnosed with AMI. A comprehensive search was conducted in PubMed, Web of Science, the Cochrane Library, and Embase for relevant studies published up to May 2024, following the PICOS principle. Eligible studies included randomized clinical trials and cohort studies comparing SGLT2-i with placebo regarding all-cause mortality, rehospitalization for HF, cardiovascular mortality, and the incidence of nonfatal MI in AMI patients. Patient-level data from each trial were synthesized into a pooled dataset and analyzed using a mixed-effects or random-effects model based on the I2 statistic. Ten clinical trials enrolling 15,748 participants (6913 in the SGLT2-i group and 8835 in the placebo group) were included. The follow-up duration ranged from 12 weeks to 2.1 years. SGLT2-i significantly reduced rehospitalization for HF (RR: 0.69, 95% CI 0.60-0.81, P < 0.00001, I2 = 39%) compared to placebo. However, SGLT2-i did not significantly reduce the risk of all-cause death (RR: 0.85, 95% CI 0.72-1.00, P = 0.05, I2 = 46%), cardiovascular death (RR: 0.96, 95% CI 0.78-1.18, P = 0.67, I2 = 24%) or nonfatal MI (RR: 0.71, 95% CI 0.44-1.14, P = 0.16, I2 = 64%) during follow-up. Compared to placebo, SGLT2-i significantly reduced rehospitalization for HF in patients with AMI, but did not reduce the risk of all-cause death, cardiovascular death and nonfatal MI.

Dapagliflozin attenuates high glucose-and hypoxia/reoxygenation-induced injury via activating AMPK/mTOR-OPA1-mediated mitochondrial autophagy in H9c2 cardiomyocytes

This study investigated the protective effect of dapagliflozin on H9c2 cardiomyocyte function under high glucose and hypoxia/reoxygenation (HG-H/R) conditions and identified the underlying molecular mechanisms. Dapagliflozin reduced the level of lactate dehydrogenase and reactive oxygen species in cardiomyocytes under HG-H/R conditions and was accompanied by a decrease in caspase-3/9 activity. In addition, Dapagliflozin significantly reduced mitochondrial permeability transition pore opening and increased ATP content, accompanied by upregulation of OPA1 with autophagy-related protein molecules and activation of the AMPK/mTOR signalling pathway in HG-H/R treated cardiomyocytes. OPA1 knockdown or compound C treatment attenuated the protective effects of dapagliflozin on the cardiomyocytes under HG-H/R conditions. Downregulation of OPA1 expression increased mitochondrial intolerance in cardiomyocytes during HG-H/R injury and the AMPK-mTOR-autophagy signalling is a key mechanism for protecting mitochondrial function and reducing cardiomyocyte apoptosis. Collectively, dapagliflozin exerted protective effects on the cardiomyocytes under HG-H/R conditions. Dapagliflozin attenuated myocardial HG-H/R injury by activating AMPK/mTOR-OPA1-mediated mitochondrial autophagy.

Dapagliflozin targets SGLT2/SIRT1 signaling to attenuate the osteogenic transdifferentiation of vascular smooth muscle cells

Vascular calcification is a complication that is frequently encountered in patients affected by atherosclerosis, diabetes, and chronic kidney disease (CKD), and that is characterized by the osteogenic transdifferentiation of vascular smooth muscle cells (VSMCs). At present, there remains a pressing lack of any effective therapies that can treat this condition. The sodium-glucose transporter 2 (SGLT2) inhibitor dapagliflozin (DAPA) has shown beneficial effects in cardiovascular disease. The role of this inhibitor in the context of vascular calcification, however, remains largely uncharacterized. Our findings revealed that DAPA treatment was sufficient to alleviate in vitro and in vivo osteogenic transdifferentiation and vascular calcification. Interestingly, our study demonstrated that DAPA exerts its anti-calcification effects on VSMCs by directly targeting SGLT2, with the overexpression of SGLT2 being sufficient to attenuate these beneficial effects. DAPA was also able to limit the glucose levels and NAD+/NADH ratio in calcified VSMCs, upregulating sirtuin 1 (SIRT1) in a caloric restriction (CR)-dependent manner. The SIRT1-specific siRNA and the SIRT1 inhibitor EX527 attenuated the anti-calcification effects of DAPA treatment. DAPA was also to drive SIRT1-mediated deacetylation and consequent degradation of hypoxia-inducible factor-1α (HIF-1α). The use of cobalt chloride and proteasome inhibitor MG132 to preserve HIF-1α stability mitigated the anti-calcification activity of DAPA. These analyses revealed that the DAPA/SGLT2/SIRT1 axis may therefore represent a viable novel approach to treating vascular calcification, offering new insights into how SGLT2 inhibitors may help prevent and treat vascular calcification.

Dapagliflozin mitigates cellular stress and inflammation through PI3K/AKT pathway modulation in cardiomyocytes, aortic endothelial cells, and stem cell-derived β cells

Dapagliflozin (DAPA), a sodium-glucose cotransporter 2 (SGLT2) inhibitor, is well-recognized for its therapeutic benefits in type 2 diabetes (T2D) and cardiovascular diseases. In this comprehensive in vitro study, we investigated DAPA's effects on cardiomyocytes, aortic endothelial cells (AECs), and stem cell-derived beta cells (SC-β), focusing on its impact on hypertrophy, inflammation, and cellular stress. Our results demonstrate that DAPA effectively attenuates isoproterenol (ISO)-induced hypertrophy in cardiomyocytes, reducing cell size and improving cellular structure. Mechanistically, DAPA mitigates reactive oxygen species (ROS) production and inflammation by activating the AKT pathway, which influences downstream markers of fibrosis, hypertrophy, and inflammation. Additionally, DAPA's modulation of SGLT2, the Na+/H + exchanger 1 (NHE1), and glucose transporter (GLUT 1) type 1 highlights its critical role in maintaining cellular ion balance and glucose metabolism, providing insights into its cardioprotective mechanisms. In aortic endothelial cells (AECs), DAPA exhibited notable anti-inflammatory properties by restoring AKT and phosphoinositide 3-kinase (PI3K) expression, enhancing mitogen-activated protein kinase (MAPK) activation, and downregulating inflammatory cytokines at both the gene and protein levels. Furthermore, DAPA alleviated tumor necrosis factor (TNFα)-induced inflammation and stress responses while enhancing endothelial nitric oxide synthase (eNOS) expression, suggesting its potential to preserve vascular function and improve endothelial health. Investigating SC-β cells, we found that DAPA enhances insulin functionality without altering cell identity, indicating potential benefits for diabetes management. DAPA also upregulated MAFA, PI3K, and NRF2 expression, positively influencing β-cell function and stress response. Additionally, it attenuated NLRP3 activation in inflammation and reduced NHE1 and glucose-regulated protein GRP78 expression, offering novel insights into its anti-inflammatory and stress-modulating effects. Overall, our findings elucidate the multifaceted therapeutic potential of DAPA across various cellular models, emphasizing its role in mitigating hypertrophy, inflammation, and cellular stress through the activation of the AKT pathway and other signaling cascades. These mechanisms may not only contribute to enhanced cardiac and endothelial function but also underscore DAPA's potential to address metabolic dysregulation in T2D.

Chronic stress in adulthood results in microvascular dysfunction and subsequent depressive-like behavior

Depression is a prevalent mental disorder characterized by unknown pathogenesis and challenging treatment. Recent meta-analyses reveal an association between cardiovascular risk factors and an elevated risk of depression. Despite this, the precise role of vascular injury in depression development remains unclear. In this investigation, we assess vascular system function in three established animal models of depression- chronic unpredictable mild stress (CUMS), chronic social defeat stress (CSDS) and maternal separation (MS)-utilizing ultrasonography and laser Doppler measurement. All three model animals exhibit anhedonia and despair-like behavior. However, significant microvascular dysfunction (not macrovascular) is observed in animals subjected to CUMS and CSDS models, while such dysfunction is absent in the MS model. Statistical analysis further indicates that microcirculation dysfunction is not only associated with depression-like behavior but is also intricately involved in the development of depression in the CUMS and CSDS models. Furthermore, our study has proved for the first time that endothelial nitric oxide synthase-deficient (eNOS+/-) mice, which is a classic model of vascular endothelial injury, showed depression-like behavior which occurred two months later than microvascular dysfunction. Notably, the mitigation of microvascular dysfunction successfully reverses depression-like behavior in eNOS+/- mice by enhancing nitric oxide production. In conclusion, this study unveils the pivotal role of microvascular dysfunction in the onset of depression induced by chronic stress in adulthood and proposes that modulating microvascular function may serve as a potential intervention in the treatment of depression.

Protective Mechanisms of SGLTi in Ischemic Heart Disease

Ischemic heart disease (IHD) is a common clinical cardiovascular disease with high morbidity and mortality. Sodium glucose cotransporter protein inhibitor (SGLTi) is a novel hypoglycemic drug. To date, both clinical trials and animal experiments have shown that SGLTi play a protective role in IHD, including myocardial infarction (MI) and ischemia/reperfusion (I/R). The protective effects may be involved in mechanisms of energy metabolic conversion, anti-inflammation, anti-fibrosis, ionic homeostasis improvement, immune cell development, angiogenesis and functional regulation, gut microbiota regulation, and epicardial lipids. Thus, this review summarizes the above mechanisms and aims to provide theoretical evidence for therapeutic strategies for IHD.

The role and mechanism of dapagliflozin in Alzheimer disease: A review

Alzheimer disease (AD), as the main type of dementia, is primarily characterized by cognitive dysfunction across multiple domains. Current drugs for AD have not achieved the desired clinical efficacy due to potential risks, inapplicability, high costs, significant side effects, and poor patient compliance. However, recent findings offer new hope by suggesting that sodium-glucose cotransporter 2 inhibitors (SGLT-2i) may possess neuroprotective properties, potentially opening up novel avenues for the treatment of AD. This review delves deeply into the multifaceted mechanisms of action of SGLT-2i in AD, encompassing antioxidative stress, antineuroinflammation, upregulation of autophagy, antiapoptosis, acetylcholinesterase inhibitor activity, and protection of endothelial cells against atherosclerosis and damage to the blood-brain barrier, among others. Furthermore, it provides an overview of recent advances in clinical research on this drug. These findings suggest that SGLT-2i is poised to emerge as a pivotal candidate for the treatment of AD, given its diverse functional effects.

ANOCA updated: From pathophysiology to modern clinical practice

Lately, a large number of stable ischemic patients, with no obstructed coronary arteries are being diagnosed. Despite this condition, which is being described as angina with no obstructive coronary arteries (ANOCA), was thought to be benign, recent evidence report that it is associated with increased risk for adverse cardiovascular outcomes. ANOCA is more frequent in women and, pathophysiologically, it is predominantly related with microvascular dysfunction, while other factors, such as endothelial dysfunction, inflammation and autonomic nervous system seem to also play a major role to its development, while other studies implicate ANOCA and microvascular dysfunction in the pathogenesis of heart failure with preserved ejection fraction. For establishing an ANOCA diagnosis, measurement including coronary flow reserve (CFR), microvascular resistance (IMR) and hyperemic microvascular resistance (HMR) are mostly used in clinical practice. In addition, new modalities, such as optical coherence tomography (OCT) are being tested and show promising results for future diagnostic use. Regarding management, pharmacotherapy consists of a wide selection of drugs, according to the respected pathophysiology of the disease (vasospastic angina or microvascular dysfunction), while research for new treatment options including interventional techniques, is currently ongoing. This review, therefore, aims to provide a comprehensive analysis of all aspects related to ANOCA, from pathophysiology to clinical managements, as well as clinical implications and suggestions for future research efforts, which will help advance our understanding of the syndrome and establish more, evidence-based, therapies.

Relationship between sodium-glucose cotransporter 2 inhibitors and atrial fibrillation recurrence after pulmonary vein isolation in patients with type 2 diabetes and persistent atrial fibrillation

BACKGROUND

The impact of sodium-glucose cotransporter 2 (SGLT2) inhibitors on the postoperative recurrence of atrial fibrillation (AF) in patients with persistent AF undergoing an initial radiofrequency ablation is not yet established. The objective of this study is to assess the impact of SGLT2 inhibitors on the recurrence of AF after radiofrequency ablation in patients with type 2 diabetes complicated persistent AF.

METHODS

A total of 182 patients with type 2 diabetes and persistent AF, who underwent their first radiofrequency ablation for AF at our center, were enrolled and divided into two groups: the SGLT2 inhibitor group and the non-SGLT2 inhibitor group. The main outcome of the follow-up was the postoperative recurrence of AF.

RESULTS

A total of 49 participants experienced AF recurrence. The use of SGLT2 inhibitors in patients with type 2 diabetes who underwent AF ablation was associated with a significantly lower risk of AF recurrence (adjusted hazard ratio: 0.65; 95% confidence interval: 0.28-0.83; p < .01).

CONCLUSIONS

The use of SGLT2 inhibitors is associated with a decreased risk of arrhythmia recurrence after AF ablation in patients with type 2 diabetes complicated with persistent AF.

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.

The role of serine/threonine protein kinases in cardiovascular disease and potential therapeutic methods

Protein phosphorylation is an important link in a variety of signaling pathways, and most of the important life processes in cells involve protein phosphorylation. Based on the amino acid residues of phosphorylated proteins, protein kinases can be categorized into the following families: serine/threonine protein kinases, tyrosine-specific protein kinases, histidine-specific protein kinases, tryptophan kinases, and aspartate/glutamyl protein kinases. Of all the protein kinases, most are serine/threonine kinases, where serine/threonine protein kinases are protein kinases that catalyze the phosphorylation of serine or threonine residues on target proteins using ATP as a phosphate donor. The current socially accepted classification of serine/threonine kinases is to divide them into seven major groups: protein kinase A, G, C (AGC), CMGC, Calmodulin-dependent protein kinase (CAMK), Casein kinase (CK1), STE, Tyrosine kinase (TKL) and others. After decades of research, a preliminary understanding of the specific classification and respective functions of serine/threonine kinases has entered a new period of exploration. In this paper, we review the literature of the previous years and introduce the specific signaling pathways and related therapeutic modalities played by each of the small protein kinases in the serine/threonine protein kinase family, respectively, in some common cardiovascular system diseases such as heart failure, myocardial infarction, ischemia-reperfusion injury, and diabetic cardiomyopathy. To a certain extent, the current research results, including molecular mechanisms and therapeutic methods, are fully summarized and a systematic report is made for the prevention and treatment of cardiovascular diseases in the future.

Phosphoglycerate mutase 5 exacerbates alcoholic cardiomyopathy in male mice by inducing prohibitin-2 dephosphorylation and impairing mitochondrial quality control

BACKGROUND

The induction of mitochondrial quality control (MQC) mechanisms is essential for the re-establishment of mitochondrial homeostasis and cellular bioenergetics during periods of stress. Although MQC activation has cardioprotective effects in various cardiovascular diseases, its precise role and regulatory mechanisms in alcoholic cardiomyopathy (ACM) remain incompletely understood.

METHODS

We explored whether two mitochondria-related proteins, phosphoglycerate mutase 5 (Pgam5) and prohibitin 2 (Phb2), influence MQC in male mice during ACM.

RESULTS

Myocardial Pgam5 expression was upregulated in a male mouse model of ACM. Notably, following ACM induction, heart dysfunction was markedly reversed in male cardiomyocyte-specific Pgam5 knockout (Pgam5cKO) mice. Meanwhile, in alcohol-treated male mouse-derived neonatal cardiomyocytes, Pgam5 depletion preserved cell survival and restored mitochondrial dynamics, mitophagy, mitochondrial biogenesis and the mitochondrial unfolded protein response (mtUPR). We further found that in alcohol-treated cardiomyocyte, Pgam5 binds Phb2 and induces its dephosphorylation at Ser91. Alternative transduction of phospho-mimetic (Phb2S91D) and phospho-defective (Phb2S9A) Phb2 mutants attenuated and enhanced, respectively, alcohol-related mitochondrial dysfunction in cardiomyocytes. Moreover, transgenic male mice expressing Phb2S91D were resistant to alcohol-induced heart dysfunction.

CONCLUSIONS

We conclude that ACM-induced Pgam5 upregulation results in Pgam5-dependent Phb2S91 dephosphorylation, leading to MQC destabilisation and mitochondrial dysfunction in heart. Therefore, modulating the Pgam5/Phb2 interaction could potentially offer a novel therapeutic strategy for ACM in male mice.

HIGHLIGHTS

Pgam5 knockout attenuates alcohol-induced cardiac histopathology and heart dysfunction in male mice. Pgam5 KO reduces alcohol-induced myocardial inflammation, lipid peroxidation and metabolic dysfunction in male mice. Pgam5 depletion protects mitochondrial function in alcohol-exposed male mouse cardiomyocytes. Pgam5 depletion normalises MQC in ACM. EtOH impairs MQC through inducing Phb2 dephosphorylation at Ser91. Pgam5 interacts with Phb2 and induces Phb2 dephosphorylation. Transgenic mice expressing a Ser91 phospho-mimetic Phb2 mutant are resistant to ACM.

Endothelial Protection by Sodium-Glucose Cotransporter 2 Inhibitors: A Literature Review of In Vitro and In Vivo Studies

Endothelial dysfunction often precedes the development of cardiovascular diseases, including heart failure. The cardioprotective benefits of sodium-glucose cotransporter 2 inhibitors (SGLT2is) could be explained by their favorable impact on the endothelium. In this review, we summarize the current knowledge on the direct in vitro effects of SGLT2is on endothelial cells, as well as the systematic observations in preclinical models. Four putative mechanisms are explored: oxidative stress, nitric oxide (NO)-mediated pathways, inflammation, and endothelial cell survival and proliferation. Both in vitro and in vivo studies suggest that SGLT2is share a class effect on attenuating reactive oxygen species (ROS) and on enhancing the NO bioavailability by increasing endothelial nitric oxide synthase activity and by reducing NO scavenging by ROS. Moreover, SGLT2is significantly suppress inflammation by preventing endothelial expression of adhesion receptors and pro-inflammatory chemokines in vivo, indicating another class effect for endothelial protection. However, in vitro studies have not consistently shown regulation of adhesion molecule expression by SGLT2is. While SGLT2is improve endothelial cell survival under cell death-inducing stimuli, their impact on angiogenesis remains uncertain. Further experimental studies are required to accurately determine the interplay among these mechanisms in various cardiovascular complications, including heart failure and acute myocardial infarction.

The pathological mechanisms and potential therapeutic drugs for myocardial ischemia reperfusion injury

BACKGROUND

Cardiovascular disease is the main cause of death and disability, with myocardial ischemia being the predominant type that poses a significant threat to humans. Reperfusion, an essential therapeutic approach, promptly reinstates blood circulation to the ischemic myocardium and stands as the most efficacious clinical method for myocardial preservation. Nevertheless, the restoration of blood flow associated with this process can potentially induce myocardial ischemia-reperfusion injury (MIRI), thereby diminishing the effectiveness of reperfusion and impacting patient prognosis. Therefore, it is of great significance to prevent and treat MIRI.

PURPOSE

MIRI is an important factor affecting the prognosis of patients, and there is no specific in-clinic treatment plan. In this review, we have endeavored to summarize its pathological mechanisms and therapeutic drugs to provide more powerful evidence for clinical application.

METHODS

A comprehensive literature review was conducted using PubMed, Web of Science, Embase, Medline and Google Scholar with a core focus on the pathological mechanisms and potential therapeutic drugs of MIRI.

RESULTS

Accumulated evidence revealed that oxidative stress, calcium overload, mitochondrial dysfunction, energy metabolism disorder, ferroptosis, inflammatory reaction, endoplasmic reticulum stress, pyroptosis and autophagy regulation have been shown to participate in the process, and that the occurrence and development of MIRI are related to plenty of signaling pathways. Currently, a range of chemical drugs, natural products, and traditional Chinese medicine (TCM) preparations have demonstrated the ability to mitigate MIRI by targeting various mechanisms.

CONCLUSIONS

At present, most of the research focuses on animal and cell experiments, and the regulatory mechanisms of each signaling pathway are still unclear. The translation of experimental findings into clinical practice remains incomplete, necessitating further exploration through large-scale, multi-center randomized controlled trials. Given the absence of a specific drug for MIRI, the identification of therapeutic agents to reduce myocardial ischemia is of utmost significance. For the future, it is imperative to enhance our understanding of the pathological mechanism underlying MIRI, continuously investigate and develop novel pharmaceutical agents, expedite the clinical translation of these drugs, and foster innovative approaches that integrate TCM with Western medicine. These efforts will facilitate the emergence of fresh perspectives for the clinical management of MIRI.

PEDF and 34-mer peptide inhibit cardiac microvascular endothelial cell ferroptosis via Nrf2/HO-1 signalling in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) represents a critical pathology in acute myocardial infarction (AMI), which is characterized by high mortality and morbidity. Cardiac microvascular dysfunction contributes to MIRI, potentially culminating in heart failure (HF). Pigment epithelium-derived factor (PEDF), which belongs to the non-inhibitory serpin family, exhibits several physiological effects, including anti-angiogenesis, anti-inflammatory and antioxidant properties. Our study aims to explore the impact of PEDF and its functional peptide 34-mer on both cardiac microvascular perfusion in MIRI rats and human cardiac microvascular endothelial cells (HCMECs) injury under hypoxia reoxygenation (HR). It has been shown that MIRI is accompanied by ferroptosis in HCMECs. Furthermore, we investigated the effect of PEDF and its 34-mer, particularly regarding the Nrf2/HO-1 signalling pathway. Our results demonstrated that PEDF 34-mer significantly ameliorated cardiac microvascular dysfunction following MIRI. Additionally, they exhibited a notable suppression of ferroptosis in HCMECs, and these effects were mediated through activation of Nrf2/HO-1 signalling. These findings highlight the therapeutic potential of PEDF and 34-mer in alleviating microvascular dysfunction and MIRI. By enhancing cardiac microvascular perfusion and mitigating endothelial ferroptosis, PEDF and its derivative peptide represent promising candidates for the treatment of AMI.

Novel Therapeutics for Type 2 Diabetes Mellitus-A Look at the Past Decade and a Glimpse into the Future

Cardiovascular disease (CVD) and kidney disease are the main causes of morbidity and mortality in type 2 diabetes mellitus (T2DM). Globally, the incidence of T2DM continues to rise. A substantial increase in the burden of CVD and renal disease, alongside the socioeconomic implications, would be anticipated. Adopting a purely glucose-centric approach focusing only on glycemic targets is no longer adequate to mitigate the cardiovascular risks in T2DM. In the past decade, significant advancement has been achieved in expanding the pharmaceutical options for T2DM, with novel agents such as the sodium-glucose cotransporter type 2 (SGLT2) inhibitors and glucagon-like peptide receptor agonists (GLP-1 RAs) demonstrating robust evidence in cardiorenal protection. Combinatorial approaches comprising multiple pharmacotherapies combined in a single agent are an emerging and promising way to not only enhance patient adherence and improve glycemic control but also to achieve the potential synergistic effects for greater cardiorenal protection. In this review, we provide an update on the novel antidiabetic agents in the past decade, with an appraisal of the mechanisms contributing to cardiorenal protection. Additionally, we offer a glimpse into the landscape of T2DM management in the near future by providing a comprehensive summary of upcoming agents in early-phase trials.

Effect of dapagliflozin on ferroptosis through the gut microbiota metabolite TMAO during myocardial ischemia-reperfusion injury in diabetes mellitus rats

Dapagliflozin (DAPA) demonstrates promise in the management of diabetic mellitus (DM) and cardiomyopathy. Trimethylamine N-oxide (TMAO) is synthesized by the gut microbiota through the metabolic conversion of choline and phosphatidylcholine. Ferroptosis may offer novel therapeutic avenues for the management of diabetes and myocardial ischemia-reperfusion injury (IRI). However, the precise mechanism underlying ferroptosis in cardiomyocytes and the specific role of TMAO generated by gut microbiota in the therapeutic approach for DM and myocardial IRI utilizing DAPA need to be further explored. Nine male SD rats with specific pathogen-free (SPF) status were randomly divided equally into the normal group, the DM + IRI (DIR) group, and the DAPA group. The diversity of the gut microbiota was analyzed using 16S rRNA gene sequencing. Additionally, the Wekell technique was employed to measure the levels of TMAO in the three groups. Application of network pharmacology to search for intersection targets of DAPA, DIR, and ferroptosis, and RT-PCR experimental verification. Ultimately, the overlapping targets that were acquired were subjected to molecular docking analysis with TMAO. The changes of Bacteroidetes and Firmicutes in the gut microbiota of DIR rats were most significantly affected by DAPA. Escherichia-Shigella and Prevotella_9 within the phylum Bacteroidetes could be identified as the primary effects of DAPA on DIR. Compared with the normal group, the TMAO content in the DIR group was significantly increased, while the TMAO content in the DAPA group was decreased compared to the DIR group. For the network pharmacology analysis, DAPA and DIR generated 43 intersecting target genes, and then further intersected with ferroptosis-related genes, resulting in 11 overlapping target genes. The mRNA expression of ALB, HMOX1, PPARG, CBS, LCN2, and PPARA decreased in the DIR group through reverse transcription polymerase chain reaction (RT-PCR) validation, while the opposite trend was observed in the DAPA group. The docking score between TMAO and DPP4 was - 5.44, and the MM-GBSA result of - 22.02 kcal/mol. It epitomizes the finest docking performance among all the target genes with the lowest score. DAPA could reduce the levels of metabolite TMAO produced by gut microbiota, thereby regulating related target genes to decrease ferroptosis in DIR cardiomyocytes.

Cardiovascular outcomes and molecular targets for the cardiac effects of Sodium-Glucose Cotransporter 2 Inhibitors: A systematic review

Sodium-glucose cotransporter 2 inhibitors (SGLT2i), a new class of glucose-lowering drugs traditionally used to control blood glucose levels in patients with type 2 diabetes mellitus, have been proven to reduce major adverse cardiovascular events, including cardiovascular death, in patients with heart failure irrespective of ejection fraction and independently of the hypoglycemic effect. Because of their favorable effects on the kidney and cardiovascular outcomes, their use has been expanded in all patients with any combination of diabetes mellitus type 2, chronic kidney disease and heart failure. Although mechanisms explaining the effects of these drugs on the cardiovascular system are not well understood, their effectiveness in all these conditions suggests that they act at the intersection of the metabolic, renal and cardiac axes, thus disrupting maladaptive vicious cycles while contrasting direct organ damage. In this systematic review we provide a state of the art of the randomized controlled trials investigating the effect of SGLT2i on cardiovascular outcomes in patients with chronic kidney disease and/or heart failure irrespective of ejection fraction and diabetes. We also discuss the molecular targets and signaling pathways potentially explaining the cardiac effects of these pharmacological agents, from a clinical and experimental perspective.

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 sodium‑glucose 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.

Roles of flavonoids in ischemic heart disease: Cardioprotective effects and mechanisms against myocardial ischemia and reperfusion injury

BACKGROUND

Flavonoids are extensively present in fruits, vegetables, grains, and medicinal plants. Myocardial ischemia and reperfusion (MI/R) comprise a sequence of detrimental incidents following myocardial ischemia. Research indicates that flavonoids have the potential to act as cardioprotective agents against MI/R injuries. Several specific flavonoids, e.g., luteolin, hesperidin, quercetin, kaempferol, and puerarin, have demonstrated cardioprotective activities in animal models.

PURPOSE

The objective of this review is to identify the cardioprotective flavonoids, investigate their mechanisms of action, and explore their application in myocardial ischemia.

METHODS

A search of PubMed database and Google Scholar was conducted using keywords "myocardial ischemia" and "flavonoids". Studies published within the last 10 years reporting on the cardioprotective effects of natural flavonoids on animal models were analyzed.

RESULTS

A total of 55 natural flavonoids were identified and discussed within this review. It can be summarized that flavonoids regulate the following main strategies: antioxidation, anti-inflammation, calcium modulation, mitochondrial protection, ER stress inhibition, anti-apoptosis, ferroptosis inhibition, autophagy modulation, and inhibition of adverse cardiac remodeling. Additionally, the number and position of OH, 3'4'-catechol, C2=C3, and C4=O may play a significant role in the cardioprotective activity of flavonoids.

CONCLUSION

This review serves as a reference for designing a daily diet to prevent or reduce damages following ischemia and screening of flavonoids for clinical application.

Dapagliflozin alleviates high glucose-induced injury of endothelial cells via inducing autophagy

Hyperglycaemia is a key factor in the progression of diabetes complications. Dapagliflozin (DAPA), a new type of hypoglycaemic agent, has been shown to play an important role in anti-apoptotic, anti-inflammatory and antioxidant activities. Previous studies have demonstrated an endothelial protective effect of DAPA, but the underlying mechanism was still unclear. Autophagy is a homeostatic cellular mechanism that circulates unfolded proteins and damaged organelles through lysosomal dependent degradation. In this study, we aimed to investigate whether DAPA plays a protective role against high glucose (HG)-induced endothelial injury through regulating autophagy. The results showed that DAPA treatment resulted in increased cell viability. Additionally, DAPA treatment decreased interleukin (IL)-1β, IL-6, and tumour necrosis factor-α levels in endothelial cells subjected to HG conditions. We observed that HG inhibited autophagy, and DAPA increased the autophagy level by inhibiting the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signalling pathway. Chloroquine reversed all of these beneficial effects as an autophagy inhibitor. In summary, the endothelial protective effect of DAPA in HG can be attributed in part to its role in activating of autophagy via the AKT/mTOR signalling pathway. Therefore, suggesting that the activation of autophagy by DAPA may be a novel target for the treatment of HG-induced endothelial cell injury.

DNA-PKcs Phosphorylates Cofilin2 to Induce Endothelial Dysfunction and Microcirculatory Disorder in Endotoxemic Cardiomyopathy

The presence of endotoxemia is strongly linked to the development of endothelial dysfunction and disruption of myocardial microvascular reactivity. These factors play a crucial role in the progression of endotoxemic cardiomyopathy. Sepsis-related multiorgan damage involves the participation of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs). However, whether DNA-PKcs contributes to endothelial dysfunction and myocardial microvascular dysfunction during endotoxemia remains unclear. Hence, we conducted experiments in mice subjected to lipopolysaccharide (LPS)-induced endotoxemic cardiomyopathy, as well as assays in primary mouse cardiac microvascular endothelial cells. Results showed that endothelial-cell-specific DNA-PKcs ablation markedly attenuated DNA damage, sustained microvessel perfusion, improved endothelial barrier function, inhibited capillary inflammation, restored endothelium-dependent vasodilation, and improved heart function under endotoxemic conditions. Furthermore, we show that upon LPS stress, DNA-PKcs recognizes a TQ motif in cofilin2 and consequently induces its phosphorylation at Thr25. Phosphorylated cofilin2 shows increased affinity for F-actin and promotes F-actin depolymerization, resulting into disruption of the endothelial barrier integrity, microvascular inflammation, and defective eNOS-dependent vasodilation. Accordingly, cofilin2-knockin mice expressing a phospho-defective (T25A) cofilin2 mutant protein showed improved endothelial integrity and myocardial microvascular function upon induction of endotoxemic cardiomyopathy. These findings highlight a novel mechanism whereby DNA-PKcs mediates cofilin2Thr25 phosphorylation and subsequent F-actin depolymerization to contribute to endotoxemia-related cardiac microvascular dysfunction.

Dapagliflozin ameliorated retinal vascular permeability in diabetic retinopathy rats by suppressing inflammatory factors

BACKGROUND

Diabetic retinopathy is a common microvascular complication of diabetes and one of the major causes of blindness in the working-age population. Emerging evidence has elucidated that inflammation drives the key mechanism of diabetes-mediated retinal disturbance. As a new therapeutic drug targeting diabetes, whether dapagliflozin could improve vascular permeability from the perspective of anti-inflammatory effect need to be further explored.

METHODS

Type 2 diabetic retinopathy rat model was established and confirmed by fundus fluorescein angiography (FFA). ELISA detected level of plasma inflammatory factors and C-peptide. HE staining, immunohistochemistry and western blot detected histopathology changes of retina, expression of retinal inflammatory factors and tight junction proteins.

RESULTS

Dapagliflozin exhibited hypoglycemic effect comparable to insulin, but did not affect body weight. By inhibiting expression of inflammatory factors (NLRP3, Caspase-1, IL-18, NF-κB) in diabetic retina and plasma, dapagliflozin reduced damage of retinal tight junction proteins and improved retinal vascular permeability. The anti-inflammatory effect of dapagliflozin was superior to insulin.

CONCLUSIONS

Dapagliflozin improved retinal vascular permeability by reducing diabetic retinal and plasma inflammatory factors. The anti-inflammatory mechanism of dapagliflozin is independent of hypoglycemic effect and superior to insulin.

The use of sodium-glucose cotransporter 2 inhibitors and the incidence of uveitis in type 2 diabetes: a population-based cohort study

Introduction

To survey the potential correlation between the application of sodium-glucose cotransporter 2 (SGLT2) inhibitors and the incidence of uveitis in individuals with type 2 diabetes mellitus (T2DM).

Material and methods

A retrospective cohort study using the National Health Insurance Research Database (NHIRD) was conducted. The T2DM patients using SGLT2 inhibitors and those taking other anti-diabetic medications were assigned to the SGLT2 group and the control group, respectively, with a 1 : 2 ratio via the propensity score-matching (PSM) method. The major outcome in this study is the development of uveitis according to the diagnostic codes. The Cox proportional hazard regression was adopted to yield the adjusted hazard ratio (aHR) with 95% confidence interval (CI) between the groups.

Results

There were 147 and 371 new uveitis episodes in the SGLT2 and control groups after the follow-up period up to 5 years. The incidence of uveitis in the SGLT2 group (aHR = 0.736, 95% CI: 0.602-0.899, p = 0.0007) was significantly lower than that in the control group after adjusting for the effect of all the confounders. In the subgroup analyses, the SGLT2 inhibitors showed a higher correlation with low uveitis incidence in T2DM patients aged under 50 than T2DM individuals aged over 50 years (p = 0.0012), while the effect of SGLT2 inhibitors on the incidence of anterior and posterior uveitis development was similar (p = 0.7993).

Conclusions

The use of SGLT2 inhibitors could be an independent protective factor for uveitis development in T2DM population.

The correlation between admission hyperglycemia and 30-day readmission after hip fracture surgery in geriatric patients: a propensity score-matched study

Purpose

This study aimed to investigate the association between admission hyperglycemia and 30-day readmission after hip fracture surgery in geriatric patients.

Methods

This retrospective study included 1253 geriatric hip fracture patients. Patients were categorized into normoglycemia(<6.10 mmol/L) and hyperglycemia groups(≥6.10 mmol/L) based on admission blood glucose. We performed multivariable logistic regression analyses and propensity score matching (PSM) to estimate adjusted odds ratios and 95% confidence intervals for 30-day readmission, controlling for potential confounding factors. An analysis of the dose-dependent association between admission blood glucose and the probability of 30-day readmission was performed. Additional subgroup analysis was conducted to examine the impact of other factors on the relationship between admission blood glucose and 30-day readmission.

Results

Patients with hyperglycemia had higher 30-day readmission rates than normoglycemic patients before (19.1% vs 9.7%, p<0.001) and after PSM (18.1% vs 12.3%, p=0.035). Admission hyperglycemia was an independent predictor of increased 30-day readmission risk, with an adjusted odds ratio of 1.57 (95% CI 1.08-2.29, p=0.019) after multivariable regression and 1.57 (95% CI 1.03-2.39, p=0.036) after PSM. A dose-response relationship was observed between higher glucose levels and increased readmission risk.

Conclusion

Admission hyperglycemia is an independent risk factor for 30-day readmission after hip fracture surgery in the elderly. Routine glucose testing upon admission and perioperative glycemic control may help reduce short-term readmissions in this vulnerable population.

Dapagliflozin Suppresses Isoprenaline-Induced Cardiac Hypertrophy Through Inhibition of Mitochondrial Fission

ABSTRACT

Dapagliflozin (DAPA) is a novel oral hypoglycemic agent, and there is increasing evidence that DAPA has a protective effect against cardiovascular disease. The study aimed to investigate how DAPA inhibits cardiac hypertrophy and explore its potential mechanisms. By continuously infusing isoprenaline (ISO) for 2 weeks using a subcutaneous osmotic pump, a cardiac hypertrophic model was established in male C57BL/6 mice. On day 14 after surgery, echocardiography showed that left ventricle mass (LV mass), interventricular septum, left ventricle posterior wall diastole, and left ventricular posterior wall systole were significantly increased, and ejection fraction was decreased compared with control mice. Masson and Wheat Germ Agglutinin staining indicated enhanced myocardial fibrosis and cell morphology compared with control mice. Importantly, these effects were inhibited by DAPA treatment in ISO-induced mice. In H9c2 cells and neonatal rat cardiomyocytes, we found that mitochondrial fragmentation and mitochondrial oxidative stress were significantly augmented in the ISO-induced group. However, DAPA rescued the cardiac hypertrophy in ISO-induced H9c2 cells and neonatal rat cardiomyocytes. Mechanistically, we found that DAPA restored the PIM1 activity in ISO-induced H9c2 cells and subsequent increase in dynamin-associated protein 1 (Drp1) phosphorylation at S616 and decrease in Drp1 phosphorylation at S637 in ISO-induced cells. We found that DAPA mitigated ISO-induced cardiac hypertrophy by suppressing Drp1-mediated mitochondrial fission in a PIM1-dependent fashion.

PKM2 interacts with and phosphorylates PHB2 to sustain mitochondrial quality control against septic cerebral-cardiac injury

Sepsis induces profound disruptions in cellular homeostasis, particularly impacting mitochondrial function in cardiovascular and cerebrovascular systems. This study elucidates the regulatory role of the Pyruvate Kinase M2 (PKM2)- Prohibitin 2 (PHB2) axis in mitochondrial quality control during septic challenges and its protective effects against myocardial and cerebral injuries. Employing LPS-induced mouse models, we demonstrate a significant downregulation of PKM2 and PHB2 in both heart and brain tissues post-sepsis, with corresponding impairments in mitochondrial dynamics, including fission, fusion, and mitophagy. Overexpression of PKM2 and PHB2 not only restores mitochondrial function, as evidenced by normalized ATP production and membrane potential but also confers resistance to oxidative stress by mitigating reactive oxygen species generation. These cellular mechanisms translate into substantial in vivo benefits, with transgenic mice overexpressing PKM2 or PHB2 displaying remarkable resistance to sepsis-induced cardiomyocyte and neuronal apoptosis, and organ dysfunction. Our findings highlight the PKM2-PHB2 interaction as a novel therapeutic target for sepsis, providing a foundation for future research into mitochondrial-based interventions to treat this condition. The study's insights into the molecular underpinnings of sepsis-induced organ failure pave the way for potential clinical applications in the management of sepsis and related pathologies.

Association of sodium-glucose cotransporter 2 inhibitors with the incidence of corneal diseases in type 2 diabetes mellitus

Sodium-glucose cotransporter 2 (SGLT2) inhibitors revealed the protective function on various systemic diseases. This study aimed to determine whether the usage of SGLT2 inhibitors associates with incidences of superficial keratopathy and infectious keratitis in type 2 diabetes mellitus (T2DM) patients. A retrospective cohort study with the usage of National Health Insurance Research Database of Taiwan was conducted. The T2DM patients were divided into the SGLT2 inhibitors and control groups according to the usage of SGLT2 inhibitors or not. The major outcomes were defined as the occurrence of superficial keratopathy and infectious keratitis. There were 766 and 1037 episodes of superficial keratopathy in the SGLT2 inhibitors and control groups and SGLT2 inhibitors group showed a significantly lower incidence of superficial keratopathy than the control group (aHR: 0.721, 95% CI: 0.656-0.791, P < 0.0001). Also, there were 166 and 251 infectious keratitis events in the SGLT2 inhibitors and control groups and patients in the SGLT2 inhibitors group revealed a significantly lower infectious keratitis incidence than those in the control group (aHR: 0.654, 95% CI: 0.537-0.796, P < 0.0001). In addition, the patients that received SGLT2 inhibitors demonstrated lower cumulative incidences of both superficial keratopathy and infectious keratitis compared to the non-SGLT2 inhibitors users (both P < 0.0001). In conclusion, the usage of SGLT2 inhibitors correlates to lower incidence of superficial keratopathy and infectious keratitis in T2DM individuals, which is more significant in patients with persistent SGLT2 inhibitors application.

Salvianolic acids and its potential for cardio-protection against myocardial ischemic reperfusion injury in diabetes

The incidence of diabetes and related mortality rate increase yearly in modern cities. Additionally, elevated glucose levels can result in an increase of reactive oxygen species (ROS), ferroptosis, and the disruption of protective pathways in the heart. These factors collectively heighten the vulnerability of diabetic individuals to myocardial ischemia. Reperfusion therapies have been effectively used in clinical practice. There are limitations to the current clinical methods used to treat myocardial ischemia-reperfusion injury. As a result, reducing post-treatment ischemia/reperfusion injury remains a challenge. Therefore, efforts are underway to provide more efficient therapy. Salvia miltiorrhiza Bunge (Danshen) has been used for centuries in ancient China to treat cardiovascular diseases (CVD) with rare side effects. Salvianolic acid is a water-soluble phenolic compound with potent antioxidant properties and has the greatest hydrophilic property in Danshen. It has recently been discovered that salvianolic acids A (SAA) and B (SAB) are capable of inhibiting apoptosis by targeting the JNK/Akt pathway and the NF-κB pathway, respectively. This review delves into the most recent discoveries regarding the therapeutic and cardioprotective benefits of salvianolic acid for individuals with diabetes. Salvianolic acid shows great potential in myocardial protection in diabetes mellitus. A thorough understanding of the protective mechanism of salvianolic acid could expand its potential uses in developing medicines for treating diabetes mellitus related myocardial ischemia-reperfusion.

A newly synthesized flavone avoids COMT-catalyzed methylation and mitigates myocardial ischemia/reperfusion injury in H9C2 cells via JNK and P38 pathways

Objectives

Luteolin is a flavone that provides defense against myocardial ischemia/reperfusion (I/R) injury. However, this compound is subjected to methylation mediated by catechol-O-methyltransferase (COMT), thus influencing its pharmacological effect. To synthesize a new flavone from luteolin that avoids COMT-catalyzed methylation and find out the protective mechanism of LUA in myocardial I/R injury.

Materials and Methods

Luteolin and 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) were used to synthesize the new flavone known as LUAAPH-1 (LUA). Then, the myocardial ischemia/reperfusion injury cell model was established using H9c2 cells to detect the effect in myocardial ischemia/reperfusion regulation and to identify the underlying mechanism.

Results

Pretreatment with LUA (20 μmol/l) substantially increased cell viability while reducing cell apoptosis rate and caspase-3 expression induced by I/R, and the protective effect of LUA on cell viability was stronger than diosmetin, which is the major methylated metabolite of luteolin. In addition, intracellular reactive oxygen species (ROS) production and calcium accumulation were both inhibited by LUA. Furthermore, we identified that LUA markedly relieved the promotive effects of I/R stimulation upon JNK and p38 phosphorylation.

Conclusion

LUT pretreatment conveys significant cardioprotective effects after myocardial I/R injury, and JNK and p38 MAPK signaling pathway may be involved.

Altered Gut Microbiota as a Potential Risk Factor for Coronary Artery Disease in Diabetes: A Two-Sample Bi-Directional Mendelian Randomization Study

The current body of research points to a notable correlation between an imbalance in gut microbiota and the development of type 2 diabetes mellitus (T2D) as well as its consequential ailment, coronary artery disease (CAD). The complexities underlying the association, especially in the context of diabetic coronary artery disease (DCAD), are not yet fully understood, and the causal links require further clarification. In this study, a bidirectional Mendelian randomization (MR) methodology was utilized to explore the causal relationships between gut microbiota, T2D, and CAD. By analyzing data from the DIAGRAM, GERA, UKB, FHS, and mibioGen cohorts and examining GWAS databases, we sought to uncover genetic variants linked to T2D, CAD, and variations in gut microbiota and metabolites, aiming to shed light on the potential mechanisms connecting gut microbiota with DCAD. Our investigation uncovered a marked causal link between the presence of Oxalobacter formigenes and an increased incidence of both T2D and CAD. Specifically, a ten-unit genetic predisposition towards T2D was found to be associated with a 6.1% higher probability of an increase in the Oxalobacteraceae family's presence (β = 0.061, 95% CI = 0.002-0.119). In a parallel finding, an augmented presence of Oxalobacter was related to an 8.2% heightened genetic likelihood of CAD (β = 0.082, 95% CI = 0.026-0.137). This evidence indicates a critical pathway by which T2D can potentially raise the risk of CAD via alterations in gut microbiota. Additionally, our analyses reveal a connection between CAD risk and Methanobacteria, thus providing fresh perspectives on the roles of TMAO and carnitine in the etiology of CAD. The data also suggest a direct causal relationship between increased levels of certain metabolites - proline, lysophosphatidylcholine, asparagine, and salicylurate - and the prevalence of both T2D and CAD. Sensitivity assessments reinforce the notion that changes in Oxalobacter formigenes could pose a risk for DCAD. There is also evidence to suggest that DCAD may, in turn, affect the gut microbiota's makeup. Notably, a surge in serum TMAO levels in individuals with CAD, coinciding with a reduced presence of methanogens, has been identified as a potentially significant factor for future examination.

Dapagliflozin improves erectile dysfunction in patients with type 2 diabetes mellitus: An open-label, non-randomized pilot study

INTRODUCTION

The role of dapagliflozin on erectile dysfunction (ED), a condition widely affecting patients with type 2 diabetes mellitus (T2DM), has not yet been studied.

AIM

The aim of the study was to evaluate the effects of dapagliflozin alone or in combination with tadalafil on ED in patients with T2DM.

METHODS

This was an open-label, non-randomized pilot study involving 30 Caucasian male patients with T2DM and severe ED. They were equally divided into three groups, assigned to treatment with tadalafil 5 mg/day (Group 1), tadalafil 5 mg/day plus dapagliflozin 10 mg/day (Group 2) and dapagliflozin 10 mg/day (Group 3) for 3 months. The presence and the severity of ED were evaluated at enrolment and after treatment, by the International Index of Erectile Function 5-item (IIEF-5) questionnaire and the dynamic penile echo colour Doppler ultrasound (PCDU) examination.

RESULTS

At the end of treatment, the three groups showed a significant improvement in IIEF-5 score, by 294%, 375% and 197%, in Groups 1, 2 and 3, respectively. PCDU evaluation showed a significant increase in peak systolic velocity by 178.9%, 339% and 153%; acceleration time was significantly shortened in Group 2 (-26.2%) and was significantly lower than in Group 1 and 3 (-7.2% and -6.6%), while no significant difference was found in end-diastolic velocity after treatment. The greatest rates of improvement were observed in Group 2 for all the end points.

CONCLUSIONS

Dapagliflozin improves ED in patients with T2DM and enhances the efficacy of tadalafil. Further studies are needed to confirm our results explain the mechanism(s) by which dapagliflozin exerts its effects on ED.

METTL3 boosts mitochondrial fission and induces cardiac fibrosis after ischemia/reperfusion injury

METTL3, an RNA methyltransferase enzyme, exerts therapeutic effects on various cardiovascular diseases. Myocardial ischemia-reperfusion injury (MIRI) and subsequently cardiac fibrosis is linked to acute cardiomyocyte death or dysfunction induced by mitochondrial damage, particularly mitochondrial fission. Our research aims to elucidate the potential mechanisms underlying the therapeutic actions of METTL3 in MIRI, with focus on mitochondrial fission. When compared with Mettl3flox mice subjected to MIRI, Mettl3 cardiomyocyte knockout (Mettl3Cko) mice have reduced infarct size, decreased serum levels of myocardial injury-related factors, limited cardiac fibrosis, and preserved myocardial ultrastructure and contractile/relaxation capacity. The cardioprotective actions of Mettl3 knockout were associated with reduced inflammatory responses, decreased myocardial neutrophil infiltration, and suppression of cardiomyocyte death. Through signaling pathway validation experiments and assays in cultured HL-1 cardiomyocytes exposed to hypoxia/reoxygenation, we confirmed that Mettl3 deficiency interfere with DNA-PKcs phosphorylation, thereby blocking the downstream activation of Fis1 and preventing pathological mitochondrial fission. In conclusion, this study confirms that inhibition of METTL3 can alleviate myocardial cardiac fibrosis inflammation and prevent cardiomyocyte death under reperfusion injury conditions by disrupting DNA-PKcs/Fis1-dependent mitochondrial fission, ultimately improving cardiac function. These findings suggest new approaches for clinical intervention in patients with MIRI.

A Powerful Tool in the Treatment of Myocardial Ischemia-Reperfusion Injury: Natural and Nanoscale Modified Small Extracellular Vesicles Derived from Mesenchymal Stem Cells

Myocardial ischemia-reperfusion injury (MI/RI) constitutes a pivotal determinant impacting the long-term prognosis of individuals afflicted by ischemic cardiomyopathy subsequent to reperfusion therapy. Stem cells have garnered extensive application within the realm of MI/RI investigation, yielding tangible outcomes. Stem cell therapy encounters certain challenges in its application owing to the complexities associated with stem cell acquisition, a diminished homing rate, and a brief in vivo lifespan. Small extracellular vesicles (sEV) originating from mesenchymal stem cells (MSCs) have been demonstrated to possess the benefits of abundant availability, reduced immunogenicity, and a diminished tumorigenic incidence. They can exert their effects on damaged organs, improving injuries by transporting a lot of constituents, including proteins, RNA, lipid droplets, and more. This phenomenon has garnered substantial attention in the context of MI/RI treatment. Simultaneously, MSC-derived sEV (MSC-sEV) can exhibit enhanced therapeutic advantages through bioengineering modifications, biomaterial incorporation, and natural drug interventions. Within this discourse, we shall appraise the utilization of MSC-sEV and their derivatives in the context of MI/RI treatment, aiming to offer valuable insights for future research endeavors related to MI/RI.

Dapagliflozin protects against chronic heart failure in mice by inhibiting macrophage-mediated inflammation, independent of SGLT2

The specific mechanism of sodium-glucose cotransporter 2 (SGLT2) inhibitor in heart failure (HF) needs to be elucidated. In this study, we use SGLT2-global-knockout (KO) mice to assess the mechanism of SGLT2 inhibitor on HF. Dapagliflozin ameliorates both myocardial infarction (MI)- and transverse aortic constriction (TAC)-induced HF. Global SGLT2 deficiency does not exert protection against adverse remodeling in both MI- and TAC-induced HF models. Dapagliflozin blurs MI- and TAC-induced HF phenotypes in SGLT2-KO mice. Dapagliflozin causes major changes in cardiac fibrosis and inflammation. Based on single-cell RNA sequencing, dapagliflozin causes significant differences in the gene expression profile of macrophages and fibroblasts. Moreover, dapagliflozin directly inhibits macrophage inflammation, thereby suppressing cardiac fibroblasts activation. The cardio-protection of dapagliflozin is blurred in mice treated with a C-C chemokine receptor type 2 antagonist. Taken together, the protective effects of dapagliflozin against HF are independent of SGLT2, and macrophage inhibition is the main target of dapagliflozin against HF.

The effect of SGLT2 inhibitors on the endothelium and the microcirculation: from bench to bedside and beyond

AIMS

The beneficial cardiovascular effects of sodium-glucose cotransporter 2 (SGLT2) inhibitors irrespective of the presence of diabetes mellitus are nowadays well established and they already constitute a significant pillar for the management of heart failure, irrespective of the ejection fraction. The exact underlying mechanisms accountable for these effects, however, remain largely unknown. The direct effect on endothelial function and microcirculation is one of the most well studied. The broad range of studies presented in this review aims to link all available data from the bench to bedside and highlight the existing gaps as well as the future directions in the investigations concerning the effects of SGLT2 inhibitors on the endothelium and the microcirculation.

METHODS AND RESULTS

An extensive search has been conducted using the MEDLINE/PubMed database in order to identify the relevant studies. Preclinical data suggest that SGLT2 inhibitors directly affect endothelial function independently of glucose and specifically via several interplaying molecular pathways, resulting in improved vasodilation, increased NO production, enhanced mitochondrial homeostasis, endothelial cell viability, and angiogenesis as well as attenuation of oxidative stress and inflammation. Clinical data systematically confirm this beneficial effect on the endothelium, whereas the evidence concerning the effect on the microcirculation is conflicting.

CONCLUSION

Preclinical and clinical studies indicate that SGLT2 inhibitors attenuate endothelial and microvascular dysfunction via a combination of mechanisms, which play a role in their beneficial cardiovascular effect.

Involvement of mitochondrial dynamics and mitophagy in diabetic endothelial dysfunction and cardiac microvascular injury

Endothelial cells (ECs), found in the innermost layer of blood vessels, are crucial for maintaining the structure and function of coronary microcirculation. Dysregulated coronary microcirculation poses a fundamental challenge in diabetes-related myocardial microvascular injury, impacting myocardial blood perfusion, thrombogenesis, and inflammation. Extensive research aims to understand the mechanistic connection and functional relationship between cardiac EC dysfunction and the development, diagnosis, and treatment of diabetes-related myocardial microvascular injury. Despite the low mitochondrial content in ECs, mitochondria act as sensors of environmental and cellular stress, influencing EC viability, structure, and function. Mitochondrial dynamics and mitophagy play a vital role in orchestrating mitochondrial responses to various stressors by regulating morphology, localization, and degradation. Impaired mitochondrial dynamics or reduced mitophagy is associated with EC dysfunction, serving as a potential molecular basis and promising therapeutic target for diabetes-related myocardial microvascular injury. This review introduces newly recognized mechanisms of damaged coronary microvasculature in diabetes-related microvascular injury and provides updated insights into the molecular aspects of mitochondrial dynamics and mitophagy. Additionally, novel targeted therapeutic approaches against diabetes-related microvascular injury or endothelial dysfunction, focusing on mitochondrial fission and mitophagy in endothelial cells, are summarized.

Induction of heme oxygenase-1 antagonizes PM2.5-induced pulmonary VEGFA expression through regulating HIF-1α

Particulate matter (PM) 2.5 has long been regarded as a major risk factor of the respiratory system, which constitutes a threat to human health. Although the positive relationship between PM2.5 exposure and the development of respiratory diseases has been well established, limited studies investigate the intrinsic self-protection mechanisms against PM2.5-induced respiratory injuries. Excessive pulmonary inflammation served as a key pathogenic mechanism in PM2.5-induced airway dysfunction, and we have previously shown that PM2.5 induced the production of vascular endothelial growth factor A (VEGFA) in the bronchial epithelial cells, which subsequently led to pulmonary inflammatory responses. In the current study, we found that PM2.5 also concurrently induced the expression of the stress-responsive protein heme oxygenase-1 (HO-1) along with VEGFA in the bronchial epithelial cells both in vivo and in vitro. Importantly, knocking down of HO-1 expression significantly increased the synthesis and secretion of VEGFA; while overexpression of HO-1 showed the opposite effects, indicating that HO-1 induction can antagonize VEGFA production in the bronchial epithelial cells upon PM2.5 exposure. Mechanistically, HO-1 inhibited PM2.5-evoked VEGFA induction through modulating hypoxia-inducible factor 1 alpha (HIF-1α), which was the upstream transcriptional factor of VEGFA. More specifically, HO-1 could not only inhibit HIF-1α expression, but also suppress its transactivity. Taken together, our results suggested that HO-1 was an intrinsic protective factor against PM2.5-induced pulmonary VEGFA production with a mechanism relating to HIF-1α, thus providing a potential treatment strategy against PM2.5 triggered airway injuries.