Empagliflozin improved systolic blood pressure, endothelial dysfunction and heart remodeling in the metabolic syndrome ZSF1 rat

Empagliflozin Improves Diastolic Function in HFpEF by Restabilizing the Mitochondrial Respiratory Chain

BACKGROUND

Clinical studies demonstrated beneficial effects of sodium-glucose-transporter 2 inhibitors on the risk of cardiovascular death in patients with heart failure with preserved ejection fraction (HFpEF). However, underlying processes for cardioprotection remain unclear. The present study focused on the impact of empagliflozin (Empa) on myocardial function in a rat model with established HFpEF and analyzed underlying molecular mechanisms.

METHODS

Obese ZSF1 (Zucker fatty and spontaneously hypertensive) rats were randomized to standard care (HFpEF, n=18) or Empa (HFpEF/Empa, n=18). ZSF1 lean rats (con, n=18) served as healthy controls. Echocardiography was performed at baseline and after 4 and 8 weeks, respectively. After 8 weeks of treatment, hemodynamics were measured invasively, mitochondrial function was assessed and myocardial tissue was collected for either molecular and histological analyses or transmission electron microscopy.

RESULTS

In HFpEF Empa significantly improved diastolic function (E/é: con: 17.5±2.8; HFpEF: 24.4±4.6; P<0.001 versus con; HFpEF/Empa: 19.4±3.2; P<0.001 versus HFpEF). This was accompanied by improved hemodynamics and calcium handling and by reduced inflammation, hypertrophy, and fibrosis. Proteomic analysis demonstrated major changes in proteins involved in mitochondrial oxidative phosphorylation. Cardiac mitochondrial respiration was significantly impaired in HFpEF but restored by Empa (Vmax complex IV: con: 0.18±0.07 mmol O2/s/mg; HFpEF: 0.13±0.05 mmol O2/s/mg; P<0.041 versus con; HFpEF/Empa: 0.21±0.05 mmol O2/s/mg; P=0.012 versus HFpEF) without alterations of mitochondrial content. The expression of cardiolipin, an essential stability/functionality-mediating phospholipid of the respiratory chain, was significantly decreased in HFpEF but reverted by Empa (con: 15.9±1.7 nmol/mg protein; HFpEF: 12.5±1.8 nmol/mg protein; P=0.002 versus con; HFpEF/Empa: 14.5±1.8 nmol/mg protein; P=0.03 versus HFpEF). Transmission electron microscopy revealed a reduced size of mitochondria in HFpEF, which was restored by Empa.

CONCLUSIONS

The study demonstrates beneficial effects of Empa on diastolic function, hemodynamics, inflammation, and cardiac remodeling in a rat model of HFpEF. These effects were mediated by improved mitochondrial respiratory capacity due to modulated cardiolipin and improved calcium handling.

Emerging therapies: Potential roles of SGLT2 inhibitors in the management of pulmonary hypertension

Pulmonary hypertension (PH) is a pathophysiological disorder that may involve multiple clinical conditions and may be associated with a variety of cardiovascular and respiratory diseases. Pulmonary hypertension due to left heart disease (PH-LHD) currently lacks targeted therapies, while Pulmonary arterial hypertension (PAH), despite approved treatments, carries considerable residual risk. Metabolic dysfunction has been linked to the pathogenesis and prognosis of PH through various studies, with emerging metabolic agents offering a potential avenue for improving patient outcomes. Sodium-glucose cotransporter 2 inhibitor (SGLT-2i), a novel hypoglycemic agent, could ameliorate metabolic dysfunction and exert cardioprotective effects. Recent small-scale studies suggest SGLT-2i treatment may improve pulmonary artery pressure in patients with PH-LHD, and the PAH animal model shows that SGLT-2i can reduce pulmonary vascular remodeling and prevent progression in PAH, suggesting potential benefits for patients with PH-LHD and perhaps PAH. This review aims to succinctly review PH's pathophysiology, and the connection between metabolic dysfunction and PH, and investigate the prospective mechanisms of action of SGLT-2i in PH-LHD and PAH management.

miR-155-5p promotes hepatic steatosis via PICALM-mediated autophagy in aging hepatocytes

BACKGROUND

Hepatic steatosis, a lipid disorder characterized by the accumulation of intrahepatic fat, is more prevalent in the elderly population. This study investigates the role of miR-155-5p in the autophagy dysregulation of aging hepatic steatosis.

METHODS

We established an aging mouse model in vivo and a hepatocellular senescence model induced by low serum and palmitic acid in vitro. The fluctuations of microRNAs were derived from RNA-seq data and confirmed by qPCR in 4- and 18-month-old mouse liver tissues. Hematoxylin-eosin (H&E) staining observed pathological changes. Markers of senescence, autophagy, and lipolysis genes were analyzed using Western blot and qPCR. Bioinformatics analysis predicted miR-155-5p's target gene PICALM, confirmed by dual luciferase reporter assay and transfection of miR-155-5p mimic/inhibitor into senescent hepatocytes.

RESULTS

Senescent markers (p21, p16, and p-P53) and miR-155-5p were up-regulated in aging liver tissues and senescent hepatocytes. Bioinformatics analysis identified PICALM as a target gene of miR-155-5p, a finding further supported by dual luciferase reporter assays. Inhibition of miR-155-5p reduced expression of senescent marker genes (p16, p21, p-P53), improved autophagy (evidenced by increased LC3B-II and ATG5, and decreased P62), and enhanced lipolysis (indicated by increased ATGL and p-HSL) in senescent hepatocytes. Oil red O staining confirmed that miR-155-5p inhibition significantly reduced lipid accumulation in these cells.

CONCLUSIONS

This study suggests a potential new therapeutic approach for age-related hepatic steatosis through the inhibition of miR-155-5p to enhance autophagy.

Hepatoprotective and cardioprotective effects of empagliflozin in spontaneously hypertensive rats fed a high-fat diet

A combination of liver and heart dysfunction worsens the prognosis of human survival. The aim of this study was to investigate whether empagliflozin (a sodium-glucose transporter-2 inhibitor) has beneficial effects not only on cardiac and renal function but also on hepatic function. Adult (6-month-old) male spontaneously hypertensive rats (SHR) were fed a high-fat diet (60% fat) for four months to induce hepatic steatosis and mild heart failure. For the last two months, the rats were treated with empagliflozin (empa, 10 mg.kg-1.day-1 in the drinking water). Renal function and oral glucose tolerance test were analyzed in control (n=8), high-fat diet (SHR+HF, n=10), and empagliflozin-treated (SHR+HF+empa, n=9) SHR throughout the study. Metabolic parameters and echocardiography were evaluated at the end of the experiment. High-fat diet feeding increased body weight and visceral adiposity, liver triglyceride and cholesterol concentrations, and worsened glucose tolerance. Although the high-fat diet did not affect renal function, it significantly worsened cardiac function in a subset of SHR rats. Empagliflozin reduced body weight gain but not visceral fat deposition. It also improved glucose sensitivity and several metabolic parameters (plasma insulin, uric acid, and HDL cholesterol). In the liver, empagliflozin reduced ectopic lipid accumulation, lipoperoxidation, inflammation and pro-inflammatory HETEs, while increasing anti-inflammatory EETs. In addition, empagliflozin improved cardiac function (systolic, diastolic and pumping) independent of blood pressure. The results of our study suggest that hepatoprotection plays a decisive role in the beneficial effects of empagliflozin in preventing the progression of cardiac dysfunction induced by high-fat diet feeding.

Effects of Glucagon-Like Peptide-1 Receptor Agonists and Sodium-Glucose Cotransporter 2 Inhibitors on Intima-Media Thickness: Systematic Review and Meta-Analysis

Background

Beyond glycemic control, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter 2 inhibitors (SGLT2is) have been proposed to reduce the risk of cardiovascular events. The aim of the present systematic review and meta-analysis is to demonstrate the effects of GLP-1 RA and SGLT2is on intima-media thickness (IMT).

Methods

PubMed, EMBASE, Web of Science, SCOPUS, and Google Scholar databases were searched from inception to September 9, 2023. All interventional and observational studies that provided data on the effects of GLP-1 RAs or SGLT2is on IMT were included. Critical appraisal was performed using the Joanna Briggs Institute checklists. IMT changes (preintervention and postintervention) were pooled and meta-analyzed using a random-effects model. Subgroup analyses were based on type of medication (GLP-1 RA: liraglutide and exenatide; SGLT2i: empagliflozin, ipragliflozin, tofogliflozin, and dapagliflozin), randomized clinical trials (RCTs), and diabetic patients.

Results

The literature search yielded 708 related articles after duplicates were removed. Eighteen studies examined the effects of GLP-1 RA, and eleven examined the effects of SGLT2i. GLP-1 RA and SGLT2i significantly decreased IMT (MD = -0.123, 95% CI (-0.170, -0.076), P < 0.0001, I2 = 98% and MD = -0.048, 95% CI (-0.092, -0.004), P = 0.031, I2 = 95%, respectively). Metaregression showed that IMT change correlated with baseline IMT, whereas it did not correlate with gender, duration of diabetes, and duration of treatment.

Conclusions

Treatment with GLP-1 RA and SGLT2i can lower IMT in diabetic patients, and GLP-1 RA may be more effective than SGLT2i.

New Insights into Endothelial Dysfunction in Cardiometabolic Diseases: Potential Mechanisms and Clinical Implications

The endothelium is a monocellular layer covering the inner surface of blood vessels. It maintains vascular homeostasis regulating vascular tone and permeability and exerts anti-inflammatory, antioxidant, anti-proliferative, and anti-thrombotic functions. When the endothelium is exposed to detrimental stimuli including hyperglycemia, hyperlipidemia, and neurohormonal imbalance, different biological pathways are activated leading to oxidative stress, endothelial dysfunction, increased secretion of adipokines, cytokines, endothelin-1, and fibroblast growth factor, and reduced nitric oxide production, leading eventually to a loss of integrity. Endothelial dysfunction has emerged as a hallmark of dysmetabolic vascular impairment and contributes to detrimental effects on cardiac metabolism and diastolic dysfunction, and to the development of cardiovascular diseases including heart failure. Different biomarkers of endothelial dysfunction have been proposed to predict cardiovascular diseases in order to identify microvascular and macrovascular damage and the development of atherosclerosis, particularly in metabolic disorders. Endothelial dysfunction also plays an important role in the development of severe COVID-19 and cardiovascular complications in dysmetabolic patients after SARS-CoV-2 infection. In this review, we will discuss the biological mechanisms involved in endothelial dysregulation in the context of cardiometabolic diseases as well as the available and promising biomarkers of endothelial dysfunction in clinical practice.

Empagliflozin Induces Vascular Relaxation in Rat Coronary Artery Due to Activation of BK Channels

Purpose

The aim of this study was to investigate the effects and mechanisms of SGLT2 inhibitor empagliflozin on diabetic coronary function.

Methods

A rat diabetic model was established by injection of streptozotocin. Rats in the treated group were administered empagliflozin by gavage and rat coronary vascular tensions were measured after eight weeks. Large conductance calcium activated K+ channel currents were recorded using a patch clamp technique, while human coronary artery smooth muscle cells were used to explore the underlying mechanisms.

Results

After incubation with empagliflozin (10, 30, 100, 300, 1000 μmol/L), the Δ relaxation % of rat coronary arteries were 2.459 ± 1.304, 3.251 ± 1.119, 6.946 ± 3.407, 28.36 ± 11.47, 86.90 ± 3.868, respectively. Without and with empagliflozin in the bath solution, BK channel opening probabilities at a membrane potential of +60 mV were 0.0458 ± 0.0517 and 0.3413 ± 0.2047, respectively (p < 0.05, n = 4 cells). After incubation with iberiotoxin, the Δ tensions of rat coronary arteries in the control (Ctrl), untreated (DM), low empagliflozin (10 mg/kg/d)-treated (DM+L-EMPA) and high empagliflozin (30mg/kg/d)-treated (DM+H-EMPA) group were 103.20 ± 5.85, 40.37 ± 22.12, 99.47 ± 28.51, 78.06 ± 40.98, respectively (p < 0.01 vs Ctrl, n = 3-7; p < 0.001 vs DM+L-EMPA, n = 5-7). Empagliflozin restored high glucose-induced downregulation of Sirt1, Nrf2, and BK-β1, while the effect of empagliflozin disappeared in the presence of EX-527, a Sirt1 selective inhibitor.

Conclusion

Empagliflozin has a vasodilation effect on the coronary arteries in a concentration-dependent manner and can activate BK channels via the Sirt1-Nrf2 mechanism.

Molecular mechanism of empagliflozin cardioprotection in 5-fluorouracil (5-FU)-induced cardiotoxicity via modulation of SGLT2 and TNFα/TLR/NF-κB signaling pathway in rats

One of the commoly used chemotherapeutic agents is 5-Fluorouracil (5-FU). Unfortunately, the clinical administration of 5-FU is complicated with serious cardiotoxic effects and the safe use becomes an urgent task in cardio-oncology. Till now, there are no studies discussed the role of empagliflozin (EMP) against 5-FU cardiotoxicity. Thus, we investigated this effect and the involved mechanisms in 5-FU induced heart injury. Forty male rats of Wistar albino species were used and divided randomly into four groups. Group I is the control group, group II is EMP given group, group III is 5-FU cardiotoxic group and group IV is 5-FU plus EMP group. 5-FU (150 mg/kg) was administered as a single intraperitoneal (i.p.) dose on 1st day to induce cardiotoxicity with or without EMP (30 mg/kg/d) orally for 5 days. The dose of 5-FU is relevant to the human toxic dose. Our data showed that 5-FU given group caused cardiotoxicity with significant increase of serum cardiac enzymes, toll like receptors, enhancement of nuclear factor kappa B (NF-κB), interleukin1β (IL1β), IL6, myeloid-differentiation-factor 88 (MYD88), heart weight, malondialdehyde (MDA), tumor-necrosis-factor-alpha (TNFα), sodium glucose co-transporter 2 (SGLT2), P53 and caspase3 expression with clear histopathological features of cardiotoxicity. Moreover, there is a significant decrease in reduced glutathione (GSH) and total antioxidant capacity (TAC). Interestingly, co-administration of EMP could ameliorate 5-FU induced biochemical and histopathological changes. This effect may be due to modulation of SGLT2, decreasing inflammation, oxidative stress and apoptosis with downregulation of an essential inflammatory cascade that mediates 5-FU cardiotoxicity; TNFα/TLR/NF-κB.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-023-00204-1.

Pressure-sensitive multivesicular liposomes as a smart drug-delivery system for high-altitude pulmonary edema

Changes in bodily fluid pressures, such as pulmonary artery pressure, play key roles in high-altitude pulmonary edema (HAPE) and other disorders. Smart delivery systems releasing a drug in response to these pressures might facilitate early medical interventions. However, pressure-responsive delivery systems are unavailable. We here constructed hydrostatic pressure-sensitive multivesicular liposomes (PSMVLs) based on the incomplete filling of the internal vesicle space with neutral lipids. These liposomes were loaded with amlodipine besylate (AB), a next-generation calcium channel inhibitor, to treat HAPE on time. AB-loaded PSMVLs (AB-PSMVLs) were destroyed, and AB was released through treatment under hydrostatic pressure of at least 25 mmHg. At 25 mmHg, which is the minimum pulmonary artery pressure value in HAPE, 38.8% of AB was released within 1 h. In a mouse HAPE model, AB-PSMVLs concentrated in the lung and released AB to diffuse into the vascular wall. Intravenously injected AB-PSMVLs before HAPE modeling resulted in a stronger protection of lung tissues and respiratory function and lower occurrence of pulmonary edema than treatment with free drug or non-pressure-sensitive AB-loaded liposomes. This study offers a new strategy for developing smart drug delivery systems that respond to changes in bodily fluid pressures.

Empagliflozin reduces endoplasmic reticulum stress associated TXNIP/NLRP3 activation in tunicamycin-stimulated aortic endothelial cells

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have proven to be of therapeutic significance for cardiovascular diseases beyond the treatment of type 2 diabetes. Recent studies have demonstrated the beneficial effects of SGLT2i on endothelial cell (EC) dysfunction, but the underlying cellular mechanisms remain to be clarified. In this study, we sought to understand the effect of empagliflozin (EMPA; Jardiance®) on cell homeostasis and endoplasmic reticulum (ER) stress signaling. ER stress was induced by tunicamycin (Tm) in human abdominal aortic ECs treated with EMPA over 24 h. Tm-induced ER stress caused increases in the protein expression of thioredoxin interacting protein (TXNIP), NLR-family pyrin domain-containing protein 3 (NLRP3), C/EBP homologous protein (CHOP), and in the ratio of phospho-eIF2α/eIF2α. EMPA (50-100 µM) resulted in a dampened downstream activation of ER stress as seen by the reduced expression of CHOP and TXNIP/NLRP3 in a dose-dependent manner. Nuclear factor erythroid 2-related factor 2 (nrf2) translocation was also attenuated in EMPA-treated ECs. These results suggest that EMPA improves redox signaling under ER stress which in turn attenuates the activation of TXNIP/NLRP3.

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.

Empagliflozin treatment of cardiotoxicity: A comprehensive review of clinical, immunobiological, neuroimmune, and therapeutic implications

Cancer and cardiovascular disorders are known as the two main leading causes of mortality worldwide. Cardiotoxicity is a critical and common adverse effect of cancer-related chemotherapy. Chemotherapy-induced cardiotoxicity has been associated with various cancer treatments, such as anthracyclines, immune checkpoint inhibitors, and kinase inhibitors. Different methods have been reported for the management of chemotherapy-induced cardiotoxicity. In this regard, sodium-glucose cotransporter-2 inhibitors (SGLT2i), a class of antidiabetic agents, have recently been applied to manage heart failure patients. Further, SGLT2i drugs such as EMPA exert protective cardiac and systemic effects. Moreover, it can reduce inflammation through the mediation of major inflammatory components, such as Nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasomes, Adenosine 5'-monophosphate-activated protein kinase (AMPK), and c-Jun N-terminal kinase (JNK) pathways, Signal transducer and activator of transcription (STAT), and overall decreasing transcription of proinflammatory cytokines. The clinical outcome of EMPA administration is related to improving cardiovascular risk factors, including body weight, lipid profile, blood pressure, and arterial stiffness. Intriguingly, SGLT2 suppressors can regulate microglia-driven hyperinflammation affecting neurological and cardiovascular disorders. In this review, we discuss the protective effects of EMPA in chemotherapy-induced cardiotoxicity from molecular, immunological, and neuroimmunological aspects to preclinical and clinical outcomes.

On the wake of metformin: Do anti-diabetic SGLT2 inhibitors exert anti-aging effects?

Here we propose that SGLT2 inhibitors (SGLT2i), a class of drugs primarily used to treat type 2 diabetes, could also be repositioned as anti-aging senomorphic drugs (agents that prevent the extrinsic harmful effects of senescent cells). As observed for metformin, another anti-diabetic drug with established anti-aging potential, increasing evidence suggests that SGLT2i can modulate some relevant pathways associated with the aging process, such as free radical production, cellular energy regulation through AMP-activated protein kinase (AMPK), autophagy, and the activation of nuclear factor (NF)-kB/inflammasome. Some interesting pro-healthy effects were also observed on human microbiota. All these mechanisms converge on fueling a systemic proinflammatory condition called inflammaging, now recognized as the main risk factor for accelerated aging and increased risk of age-related disease development and progression. Inflammaging can be worsened by cellular senescence and immunosenescence, which contributes to the increased burden of senescent cells during aging, perpetuating the proinflammatory condition. Interestingly, increasing evidence suggested the direct effects of SGLT-2i against senescent cells, chronic activation of immune cells, and metabolic alterations induced by overnutrition (meta-inflammation). In this framework, we analyzed and discussed the multifaceted impact of SGLT2i, compared with metformin effects, as a potential anti-aging drug beyond diabetes management. Despite promising results in experimental studies, rigorous investigations with well-designed cellular and clinical investigations will need to validate SGLT2 inhibitors' anti-aging effects.

Reversal of fibrosis and portal hypertension by Empagliflozin treatment of CCl4-induced liver fibrosis: Emphasis on gal-1/NRP-1/TGF-β and gal-1/NRP-1/VEGFR2 pathways

To date, liver fibrosis has no clinically approved treatment. Empagliflozin (EMPA), a highly selective sodium-glucose-cotransporter-2 (SGLT2) inhibitor, has shown ameliorative potential in liver diseases without revealing its full mechanisms. Neuropilin-1 (NRP-1) is a novel regulator of profibrogenic signaling pathways related to hepatic stellate cells (HSCs) and hepatic sinusoidal endothelial cells (HSECs) that modulates intrahepatic profibrogenic and angiogenic pathways. Herein, EMPA's antifibrotic potentials and effects on galactin-1 (Gal-1)/NRP-1 signaling pathways have been evaluated in an experimental liver fibrosis rat model by testing different EMPA dose regimens. EMPA treatment brought a dose-dependent decrease in Gal-1/NRP-1 hepatic expression. This was coupled with suppression of major HSCs pro-fibrotic pathways; transforming growth factor-β (TGF-β)/TGF-βRI/Smad2 and platelet-derived growth factor-beta (PDGF-β) with a diminution of hepatic Col 1A1 level. In addition, EMPA prompted a protuberant suppression of the angiogenic pathway; vascular endothelial growth factor (VEGF)/VEGF-receptor-2 (VEGFR-2)/SH2-Domain Containing Adaptor Protein-B (Shb), and reversal of altered portal hypertension (PHT) markers; endothelin-1 (ET-1) and endothelial nitric oxide synthase (eNOS). The amelioration of liver fibrosis was coupled with a remarkable improvement in liver aminotransferases and histologic hepatic fibrosis Ishak scores. The highest EMPA dose showed a good safety profile with minimal changes in renal function and glycemic control. Thus, the current study brought about novel findings for a potential liver fibrosis treatment modality via targeting NRP-1 signaling pathways by EMPA.

Serum uric acid levels and risk of cardiovascular disease in type 2 diabetes: results from a cross-sectional study and Mendelian randomization analysis

Aims

Serum uric acid (SUA) levels have been previously linked to a higher risk of cardiovascular disease (CVD) in individuals with type 2 diabetes (T2D) according to various observational studies. However, whether this association is causally linked or simply influenced by confounding factors is unclear. Therefore, this study utilized Mendelian randomization (MR) analysis to explore the causality between SUA levels and the risk of CVD in individuals with T2D.

Methods

Our study cohort consisted of 5723 participants who were diagnosed with T2D in the National Health and Nutrition Examination Survey (NHANES) from 1999-2018. The study assessed the association between SUA levels and the risk of CVD using a multivariable logistic regression model. To further examine causality between SUA levels and CVD, a two-sample MR study was conducted utilizing genetic data from genome-wide association studies (GWAS) involving over 140,000 individuals. The main MR analysis employed the inverse-variance-weighted (IVW) method. Additionally, several sensitivity analyses were performed to evaluate the robustness and pleiotropy of the results.

Results

In the cross-sectional study, after multivariable adjustment, participants with SUA levels >6.7 mg/dL exhibited odds ratios (ORs) of 1.51 (95% CI: 1.01-2.26, p=0.049) for heart failure, 1.02 (95% CI: 0.69-1.50, p=0.937) for coronary heart disease, 1.36 (95% CI: 0.78-2.38, p=0.285) for angina, and 1.22 (95% CI: 0.80-1.85, p=0.355) for myocardial infarction when compared to participants with SUA levels ≤ 4.6 mg/dL. However, in the IVW analysis, no causality between SUA levels and the risk of heart failure was observed (OR = 1.03, 95% CI: 0.97-1.09, p = 0.293). The secondary analysis yielded similar results (OR = 1.05, 95% CI: 0.96-1.14, p = 0.299). The sensitivity analyses further supported our primary findings.

Conclusion

Based on the MR study, we did not find supporting evidence for a causal association between SUA levels and the risk of heart failure.

Effects of Dapagliflozin on Myocardial Gene Expression in BTBR Mice with Type 2 Diabetes

BACKGROUND

Dapagliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, is approved for the treatment of type 2 diabetes, heart failure, and chronic kidney disease. DAPA-HF and DELIVER trial results demonstrate that the cardiovascular protective effect of dapagliflozin extends to non-diabetic patients. Hence, the mechanism-of-action may extend beyond glucose-lowering and is not completely elucidated. We have previously shown that dapagliflozin reduces cardiac hypertrophy, inflammation, fibrosis, and apoptosis and increases ejection fraction in BTBR mice with type 2 diabetes.

METHODS

We conducted a follow-up RNA-sequencing study on the heart tissue of these animals and performed differential expression and Ingenuity Pathway analysis. Selected markers were confirmed by RT-PCR and Western blot.

RESULTS

SGLT2 had negligible expression in heart tissue. Dapagliflozin improved cardiac metabolism by decreasing glycolysis and pyruvate utilization enzymes, induced antioxidant enzymes, and decreased expression of hypoxia markers. Expression of inflammation, apoptosis, and hypertrophy pathways was decreased. These observations corresponded to the effects of dapagliflozin in the clinical trials.

SGLT2 Inhibitors in Aging-Related Cardiovascular Disease: A Review of Potential Mechanisms

Population aging combined with higher susceptibility to cardiovascular diseases in older adults is increasing the incidence of conditions such as atherosclerosis, myocardial infarction, heart failure, myocardial hypertrophy, myocardial fibrosis, arrhythmia, and hypertension. sodium-glucose cotransporter 2 inhibitors (SGLT2i) were originally developed as a novel oral drug for patients with type 2 diabetes mellitus. Unexpectedly, recent studies have shown that, beyond their effect on hyperglycemia, SGLT2i also have a variety of beneficial effects on cardiovascular disease. Experimental models of cardiovascular disease have shown that SGLT2i ameliorate the process of aging-related cardiovascular disease by inhibiting inflammation, reducing oxidative stress, and reversing endothelial dysfunction. In this review, we discuss the role of SGLT2i in aging-related cardiovascular disease and propose the use of SGLT2i to prevent and treat these conditions in older adults.

Searching for Effective Treatments in HFpEF: Implications for Modeling the Disease in Rodents

BACKGROUND

While the prevalence of heart failure with preserved ejection fraction (HFpEF) has increased over the last two decades, there still remains a lack of effective treatment. A key therapeutic challenge is posed by the absence of animal models that accurately replicate the complexities of HFpEF. The present review summarizes the effects of a wide spectrum of therapeutic agents on HF.

METHODS

Two online databases were searched for studies; in total, 194 experimental protocols were analyzed following the PRISMA protocol.

RESULTS

A diverse range of models has been proposed for studying therapeutic interventions for HFpEF, with most being based on pressure overload and systemic hypertension. They have been used to evaluate more than 150 different substances including ARNIs, ARBs, HMGR inhibitors, SGLT-2 inhibitors and incretins. Existing preclinical studies have primarily focused on LV diastolic performance, and this has been significantly improved by a wide spectrum of candidate therapeutic agents. Few experiments have investigated the normalization of pulmonary congestion, exercise capacity, animal mortality, or certain molecular hallmarks of heart disease.

CONCLUSIONS

The development of comprehensive preclinical HFpEF models, with multi-organ system phenotyping and physiologic stress-based functional testing, is needed for more successful translation of preclinical research to clinical trials.

The Impact of SGLT2 Inhibitors in the Heart and Kidneys Regardless of Diabetes Status

Chronic Kidney Disease (CKD) and Cardiovascular Disease (CVD) are two devastating diseases that may occur in nondiabetics or individuals with diabetes and, when combined, it is referred to as cardiorenal disease. The impact of cardiorenal disease on society, the economy and the healthcare system is enormous. Although there are numerous therapies for cardiorenal disease, one therapy showing a great deal of promise is sodium-dependent glucose cotransporter 2 (SGLT2) inhibitors. The SGLT family member, SGLT2, is often implicated in the pathogenesis of a range of diseases, and the dysregulation of the activity of SGLT2 markedly effects the transport of glucose and sodium across the luminal membrane of renal cells. Inhibitors of SGLT2 were developed based on the antidiabetic action initiated by inhibiting renal glucose reabsorption, thereby increasing glucosuria. Of great medical significance, large-scale clinical trials utilizing a range of SGLT2 inhibitors have demonstrated both metabolic and biochemical benefits via numerous novel mechanisms, such as sympathoinhibition, which will be discussed in this review. In summary, SGLT2 inhibitors clearly exert cardio-renal protection in people with and without diabetes in both preclinical and clinical settings. This exciting class of inhibitors improve hyperglycemia, high blood pressure, hyperlipidemia and diabetic retinopathy via multiple mechanisms, of which many are yet to be elucidated.

How Does It Work? Unraveling the Mysteries by Which Empagliflozin Helps Diabetic and Non-diabetic Patients With Heart Failure

In patients with heart failure, empagliflozin offers significant cardiovascular benefits. However, its exact mode of action is unknown. Understanding the way by which empagliflozin works in heart failure may uncover additional therapeutic targets or identify other classes of drugs that may be useful to clinicians and patients. This literature review aims to unravel the mysteries by which empagliflozin reduces cardiovascular death, cardiovascular events, and heart failure hospitalization in diabetic and non-diabetic patients. Three researchers conducted the data collection. We incorporated research that used human models, animal models, patients with diabetes, and patients without diabetes. Pathology, pathophysiology, metabolism, physiology, empagliflozin, heart failure, and cardiovascular were the search terms used to probe the mesh database on PubMed. This study showed that the mechanisms by which empagliflozin could lead to positive clinical outcomes in heart failure (HF) are as follows: down-regulation of the mammalian target of rapamycin complex 1 signaling (mTORC), decreasing sarcoplasmic reticulum calcium loss, increasing cytosolic calcium loss, inducing electrolyte-free osmotic diuresis, improving fuel efficiency, and protecting the endothelial glycocalyx. These findings were inconsistent, with no generally accepted hypotheses within the scientific community. Hence we conclude that further research is required to determine the function of Empagliflozin in heart failure and the degree to which the aforementioned mechanisms of action contribute to cardiac protection.

SGLT2 inhibitors for prevention of primary and secondary cardiovascular outcomes: A meta-analysis of randomized controlled trials

BACKGROUND

Many clinical studies have shown that sodium-glucose cotransporter 2 inhibitors (SGLT2i) reduce cardiovascular risks, such as heart failure, myocardial infarction and cardiovascular death.

OBJECTIVE

To investigate the use of SGLT2i for the prevention of primary and secondary cardiovascular outcomes.

METHODS

Pubmed, Embase and Cochrane libraries databases were searched and meta-analysis was performed using Revman 5.4.

RESULTS

Eleven studies with a total of 34,058 cases were analyzed. SGLT2i significantly reduced major adverse cardiovascular events (MACE) in patients with prior myocardial infarction (MI) (OR 0.83, 95% CI 0.73-0.94, p = 0.004), no prior MI (OR 0. 82, 95% CI 0.74-0.90, p<0.0001), prior coronary atherosclerotic disease (CAD) (OR 0.82, 95% CI 0.73-0.93, p = 0.001) and no prior CAD (OR 0.82, 95% CI 0.76-0.91, p = 0.0002) compared with placebo. In addition, SGLT2i significantly reduced hospitalization due to heart failure (HF) in patients with prior MI (OR 0.69, 95% CI 0.55-0.87, p = 0.001), no prior MI (OR 0.63, 95% CI 0.55-0. 72, p<0.00001), prior CAD (OR 0.65, 95% CI 0.53-0.79, p<0.0001) and no prior CAD (OR 0.65, 95% CI 0.56-0.75, p<0.00001) compared with placebo. SGLT2i reduced cardiovascular mortality and all-cause mortality events. MI (OR 0.79, 95% CI 0.70-0.88, p<0.0001), renal damage (OR 0.73, 95% CI 0.58-0.91, p = 0.004), all-cause hospitalization (OR 0.89, 95% CI 0.83-0.96, p = 0.002), systolic and diastolic blood pressure were all significantly reduced in patients receiving SGLT2i.

CONCLUSION

SGLT2i was effective in prevention of primary and secondary cardiovascular outcomes.

Cellular senescence and the blood-brain barrier: Implications for aging and age-related diseases

The blood-brain barrier (BBB) is a critical physiochemical interface that regulates communication between the brain and blood. It is comprised of brain endothelial cells which regulate the BBB's barrier and interface properties and is surrounded by supportive brain cell types including pericytes and astrocytes. Recent reports have suggested that the BBB undergoes dysfunction during normative aging and in disease. In this review, we consider the effect of cellular senescence, one of the nine hallmarks of aging, on the BBB. We first characterize known normative age-related changes at the BBB, and then evaluate changes in neurodegenerative diseases, with an emphasis on if/how cellular senescence is influencing these changes. We then discuss what insight has been gained from in vitro and in vivo studies of cellular senescence at the BBB. Finally, we evaluate mechanisms by which cellular senescence in peripheral pathologies can indirectly or directly affect BBB function.

Signaling pathways in vascular function and hypertension: molecular mechanisms and therapeutic interventions

Hypertension is a global public health issue and the leading cause of premature death in humans. Despite more than a century of research, hypertension remains difficult to cure due to its complex mechanisms involving multiple interactive factors and our limited understanding of it. Hypertension is a condition that is named after its clinical features. Vascular function is a factor that affects blood pressure directly, and it is a main strategy for clinically controlling BP to regulate constriction/relaxation function of blood vessels. Vascular elasticity, caliber, and reactivity are all characteristic indicators reflecting vascular function. Blood vessels are composed of three distinct layers, out of which the endothelial cells in intima and the smooth muscle cells in media are the main performers of vascular function. The alterations in signaling pathways in these cells are the key molecular mechanisms underlying vascular dysfunction and hypertension development. In this manuscript, we will comprehensively review the signaling pathways involved in vascular function regulation and hypertension progression, including calcium pathway, NO-NOsGC-cGMP pathway, various vascular remodeling pathways and some important upstream pathways such as renin-angiotensin-aldosterone system, oxidative stress-related signaling pathway, immunity/inflammation pathway, etc. Meanwhile, we will also summarize the treatment methods of hypertension that targets vascular function regulation and discuss the possibility of these signaling pathways being applied to clinical work.

The Sodium-Glucose Co-Transporter 2 (SGLT2) Inhibitor Empagliflozin Reverses Hyperglycemia-Induced Monocyte and Endothelial Dysfunction Primarily through Glucose Transport-Independent but Redox-Dependent Mechanisms

PURPOSE

Hyperglycaemia-induced oxidative stress and inflammation contribute to vascular cell dysfunction and subsequent cardiovascular events in T2DM. Selective sodium-glucose co-transporter-2 (SGLT-2) inhibitor empagliflozin significantly improves cardiovascular mortality in T2DM patients (EMPA-REG trial). Since SGLT-2 is known to be expressed on cells other than the kidney cells, we investigated the potential ability of empagliflozin to regulate glucose transport and alleviate hyperglycaemia-induced dysfunction of these cells.

METHODS

Primary human monocytes were isolated from the peripheral blood of T2DM patients and healthy individuals. Primary human umbilical vein endothelial cells (HUVECs) and primary human coronary artery endothelial cells (HCAECs), and fetoplacental endothelial cells (HPECs) were used as the EC model cells. Cells were exposed to hyperglycaemic conditions in vitro in 40 ng/mL or 100 ng/mL empagliflozin. The expression levels of the relevant molecules were analysed by RT-qPCR and confirmed by FACS. Glucose uptake assays were carried out with a fluorescent derivative of glucose, 2-NBDG. Reactive oxygen species (ROS) accumulation was measured using the H₂DFFDA method. Monocyte and endothelial cell chemotaxis were measured using modified Boyden chamber assays.

RESULTS

Both primary human monocytes and endothelial cells express SGLT-2. Hyperglycaemic conditions did not significantly alter the SGLT-2 levels in monocytes and ECs in vitro or in T2DM conditions. Glucose uptake assays carried out in the presence of GLUT inhibitors revealed that SGLT-2 inhibition very mildly, but not significantly, suppressed glucose uptake by monocytes and endothelial cells. However, we detected the significant suppression of hyperglycaemia-induced ROS accumulation in monocytes and ECs when empagliflozin was used to inhibit SGLT-2 function. Hyperglycaemic monocytes and endothelial cells readily exhibited impaired chemotaxis behaviour. The co-treatment with empagliflozin reversed the PlGF-1 resistance phenotype of hyperglycaemic monocytes. Similarly, the blunted VEGF-A responses of hyperglycaemic ECs were also restored by empagliflozin, which could be attributed to the restoration of the VEGFR-2 receptor levels on the EC surface. The induction of oxidative stress completely recapitulated most of the aberrant phenotypes exhibited by hyperglycaemic monocytes and endothelial cells, and a general antioxidant N-acetyl-L-cysteine (NAC) was able to mimic the effects of empagliflozin.

CONCLUSIONS

This study provides data indicating the beneficial role of empagliflozin in reversing hyperglycaemia-induced vascular cell dysfunction. Even though both monocytes and endothelial cells express functional SGLT-2, SGLT-2 is not the primary glucose transporter in these cells. Therefore, it seems likely that empagliflozin does not directly prevent hyperglycaemia-mediated enhanced glucotoxicity in these cells by inhibiting glucose uptake. We identified the reduction of oxidative stress by empagliflozin as a primary reason for the improved function of monocytes and endothelial cells in hyperglycaemic conditions. In conclusion, empagliflozin reverses vascular cell dysfunction independent of glucose transport but could partially contribute to its beneficial cardiovascular effects.

Benefits of the Non-Steroidal Mineralocorticoid Receptor Antagonist Finerenone in Metabolic Syndrome-Related Heart Failure with Preserved Ejection Fraction

The mineralocorticoid receptor (MR) plays an important role in the development of chronic kidney disease (CKD) and associated cardiovascular complications. Antagonizing the overactivation of the MR with MR antagonists (MRA) is a therapeutic option, but their use in patients with CKD is limited due to the associated risk of hyperkalemia. Finerenone is a non-steroidal MRA associated with an improved benefit-risk profile in comparison to steroidal MRAs. In this study, we decided to test whether finerenone improves renal and cardiac function in male hypertensive and diabetic ZSF1 rats as an established preclinical HFpEF model. Finerenone was administered at 10 mg/kg/day for 12 weeks. Cardiac function/hemodynamics were assessed in vivo. ZSF1 rats showed classical signs of CKD with increased BUN, UACR, hypertrophy, and fibrosis of the kidney together with characteristic signs of HFpEF including cardiac fibrosis, diastolic dysfunction, and decreased cardiac perfusion. Finerenone treatment did not impact kidney function but reduced renal hypertrophy and cardiac fibrosis. Interestingly, finerenone ameliorated diastolic dysfunction and cardiac perfusion in ZSF1 rats. In summary, we show for the first time that non-steroidal MR antagonism by finerenone attenuates cardiac diastolic dysfunction and improves cardiac perfusion in a preclinical HFpEF model. These cardiac benefits were found to be largely independent of renal benefits.

Bibliometric and visualized analysis of sodium-Glucose cotransporter 2 inhibitors

Background: Sodium-glucose cotransporter 2 inhibitors have proved to be extremely effective and reliable in reducing hyperglycemia, and have also been used for the treatment of cardiovascular and renal disease in patients with or without type 2 diabetes. Thousands of research articles on SGLT2 inhibitors have been published in the past, but few bibliometric analyses have systematically been studied this field. We aimed to visualize the global research hotspots and trends of SGLT2 inhibitors using a bibliometric analysis to provide new evidence and ideas for researchers and clinicians in this field. Methods: We retrieved publications from Science Citation Index Expanded of Web of Science Core Collection in 2004-2022 on 1 July 2022. Microsoft Excel, CiteSpace and VOSviewer were employed to collect publication data, analyze publication trends, and visualize relevant results. Results: We identified 4,419 original research articles on SGLT2 inhibitors published between 2004 and the first half of 2022. Global SGLT2 inhibitors-related research increased rapidly from 2004 to 2022, especially recently. United States made the greatest contribution to the topic, with (1,629, 36.86%) publications and citations (88,892). AstraZeneca was the most prolific institutions (272, 6.16%). Heerspink HJL published the most related articles (98), whereas Zinman B was cited the most frequently (1,784 citations). Diabetes Obesity and Metabolism was the journal with the most studies (406, 9.19%), and The New England Journal of Medicine was the most commonly cited journal (11,617 citations), with nine of the top 10 co-cited references published in this journal. The emerging keywords "heart failure," "diabetic cardiomyopathy," "ejection fraction," "mortality," "biomarker," "fibrosis," "ampk," and "guideline" appeared the most recently as research frontiers. Conclusion: United States is the leader in SGLT2 inhibitor research. Recently, the research on SGLT2 inhibitors has focused on clinical trials, related mechanisms, and therapy. In the future, the research on SGLT2 inhibitors will delve into molecular mechanisms, especially those related to fibrosis and AMPK, revealing the link between SGLT2 inhibitors and heart failure and diabetic cardiomyopathy will be the next research hotspot.

SGLT2 inhibitors protect cardiomyocytes from myocardial infarction: a direct mechanism?

SGLT2 inhibitors have been developed as a novel class of glucose-lowering drugs affecting reabsorption of glucose and metabolic processes. They have been recently identified to be remarkably favorable in treating cardiovascular diseases, especially heart failure. Preclinical experiments have shown that SGLT2 inhibitors could hinder the progression of myocardial infarction and alleviate cardiac remodeling by mechanisms of metabolism influence, autophagy induction, inflammation attenuation and fibrosis reduction. Here we summarize the direct mechanism of SGLT2 inhibitors on myocardial infarction and investigate whether it could be applied to the clinic in improving cardiac function and healing after myocardial infarction.

Sodium-glucose cotransporter 2 inhibitor ameliorates high fat diet-induced hypothalamic-pituitary-ovarian axis disorders

High-fat diet (HFD) consumption is known to be associated with ovulatory disorders among women of reproductive age. Previous studies in animal models suggest that HFD-induced microglia activation contributes to hypothalamic inflammation. This causes the dysfunction of the hypothalamic-pituitary-ovarian (HPO) axis, leading to subfertility. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a novel class of lipid-soluble antidiabetic drugs that target primarily the early proximal tubules in kidney. Recent evidence revealed an additional expression site of SGLT2 in the central nervous system (CNS), indicating a promising role of SGLT2 inhibitors in the CNS. In type 2 diabetes patients and rodent models, SGLT2 inhibitors exhibit neuroprotective properties through reduction of oxidative stress, alleviation of cerebral atherosclerosis and suppression of microglia-induced neuroinflammation. Furthermore, clinical observations in patients with polycystic ovary syndrome (PCOS) demonstrated that SGLT2 inhibitors ameliorated patient anthropometric parameters, body composition and insulin resistance. Therefore, it is of importance to explore the central mechanism of SGLT2 inhibitors in the recovery of reproductive function in patients with PCOS and obesity. Here, we review the hypothalamic inflammatory mechanisms of HFD-induced microglial activation, with a focus on the clinical utility and possible mechanism of SGLT2 inhibitors in promoting reproductive fitness.

Effect of high-fat diet and empagliflozin on cardiac proteins in mice

Using proteomic techniques the impact of the sodium-glucose transport protein 2 inhibitor empagliflozin on cardiac protein expression in a mouse model was assessed under normal and high-fat diet (HFD) conditions. We examined the effect of obesity on serological markers and heart function in obese mice treated with or without empagliflozin and used proteomic techniques to investigate alterations in cardiac protein expression. Using bioinformatic techniques, data were screened for differentially expressed proteins (DEPs) implicated in the putative mechanism of empagliflozin's cardioprotective effects. In C57BL/6 mice, HFD increased body weight, blood lipid, and glucose levels and was associated with structural damage to the heart. Empagliflozin reduces body weight, improves glucose and lipid metabolism, alleviates obesity-induced cardiac ventricular wall thickening, and lowers cardiac tissue collagen. The expression of several proteins was altered in the heart, mainly related to lipid metabolism. Following empagliflozin treatment, the expression of several lipid metabolism-related proteins was considerably reduced. Further examination of DEPs revealed that following empagliflozin treatment, the expressions of Apoe, Apoc1, Saa2, Apoa2, and Pon1 altered dramatically, suggesting that these proteins may be the main proteins that empagliflozin uses to treat obesity-induced aberrant lipid metabolism. Empagliflozin may protect the heart by altering the expression of genes including Apoe, Apoc1, Saa2, Apoa2, and Pon1, which are all involved in lipid metabolism disturbance in obesity.

Empagliflozin prevents angiotensin II-induced hypertension related micro and macrovascular endothelial cell activation and diastolic dysfunction in rats despite persistent hypertension: Role of endothelial SGLT1 and 2

SGLT2 inhibitors (SGLT2i) showed pronounced beneficial effects in patients with heart failure but the underlying mechanisms remain unclear. We evaluated the effect of empagliflozin, selective SGLT2i, on hypertension-induced cardiac and vascular dysfunction. Male Wistar rats received diet with or without empagliflozin (30 mg/kg/day). After 1 week, a hypertensive dose of Ang II (0.4 mg/kg/day) was administered using osmotic mini-pumps for 4 weeks. Systolic blood pressure was determined by sphygmomanometry, the cardiac function by echocardiography and ex vivo (coronary microvascular endothelial cell activation, LV remodeling and fibrosis responses), and the systemic micro and macrovascular endothelial cell activation ex vivo. Empagliflozin treatment did not affect the Ang II-induced hypertensive response. Ang II treatment increased LV mass and induced LV diastolic dysfunction, fibrosis, collagen I and ANP expression, and infiltration of macrophages. In the vasculature, it caused eNOS upregulation in the aorta and down-regulation in mesenteric microvessels associated with increased oxidative stress, ACE, AT1R, VCAM-1, MCP-1, MMP-2, and MMP-9 and collagen I expression, increased endothelial SGLT1 staining in the aorta, mesenteric and coronary microvessels, increased SGLT1 and 2 protein levels in the aorta. All Ang II-induced cardiac and vascular responses were reduced by the empagliflozin treatment. Thus, the SGLT2i effectively attenuated the deleterious impact of Ang II-induced hypertension on target organs including cardiac diastolic dysfunction and remodeling, and endothelial cell activation and pro-atherosclerotic, pro-fibrotic and pro-remodeling responses in macro and microvessels despite persistent hypertension.

New insights and advances of sodium-glucose cotransporter 2 inhibitors in heart failure

Sodium-glucose cotransporter 2 inhibitors (SGLT2is) are newly emerging insulin-independent anti-hyperglycemic agents that work independently of β-cells. Quite a few large-scale clinical trials have proven the cardiovascular protective function of SGLT2is in both diabetic and non-diabetic patients. By searching all relevant terms related to our topics over the previous 3 years, including all the names of agents and their brands in PubMed, here we review the mechanisms underlying the improvement of heart failure. We also discuss the interaction of various mechanisms proposed by diverse works of literature, including corresponding and opposing viewpoints to support each subtopic. The regulation of diuresis, sodium excretion, weight loss, better blood pressure control, stimulation of hematocrit and erythropoietin, metabolism remodeling, protection from structural dysregulation, and other potential mechanisms of SGLT2i contributing to heart failure improvement have all been discussed in this manuscript. Although some remain debatable or even contradictory, those newly emerging agents hold great promise for the future in cardiology-related therapies, and more research needs to be conducted to confirm their functionality, particularly in metabolism, Na⁺-H⁺ exchange protein, and myeloid angiogenic cells.

Novel cardioprotective mechanism for Empagliflozin in nondiabetic myocardial infarction with acute hyperglycemia

Patients with AMI and hyperglycemia upon hospital admission exhibited poorer prognosis compared with those without hyperglycemia. It is unknown whether SGLT2 inhibitors can also improve nondiabetic myocardial infarction (MI) with acute hyperglycemia and the underlying mechanisms. Here we demonstrated that hyperglycemia patients were more likely to have worse cardiac function levels, such as with Killip III/IV during hospitalization. Glucose injection-induced nondiabetic MI accompanied by acute hyperglycemia in WT mice, manifested lower survival compared with control. A significant increase in both survival and LV function was observed when treated with empagliflozin (EMPA). In addition, EMPA attenuated fibrosis and autophagy of border cardiac tissue in mice with MI accompanied by acute hyperglycemia. Applying Beclin1^+/- and NHE1 cKO mice, we found that Beclin1 deficiency improved survival. Mechanistically, EMPA had a more significant cardioprotective effect through inhibited its autophagy level by targeted Beclin1 rather than NHE1. In addition, EMPA rescued cardiomyocytes autosis induced by Tat-beclin1 or GD, conferring cardioprotection decreasing autophagic cell death. These findings provide new insights that SGLT2 inhibitor effectively ameliorates the myocardial injury in nondiabetic myocardial infarction with acute hyperglycemia through suppressing beclin1-dependent autosis rather than elusively targeting NHE1 in cardiomyocytes.

Antiarrhythmic effects and mechanisms of sodium-glucose cotransporter 2 inhibitors: A mini review

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a new type of oral hypoglycaemic agent with good cardiovascular protective effects. There are several lines of clinical evidence suggest that SGLT2i can significantly reduce the risks of heart failure, cardiovascular death, and delay the progression of chronic kidney disease. In addition, recent basic and clinical studies have also reported that SGLT2i also has good anti-arrhythmic effects. However, the exact mechanism is poorly understood. The aim of this review is to summarize recent clinical findings, studies of laboratory animals, and related study about this aspect of the antiarrhythmic effects of SGLT2i, to further explore its underlying mechanisms, safety, and prospects for clinical applications of it.

Genomic, Proteomic, and Metabolic Comparisons of Small Animal Models of Heart Failure With Preserved Ejection Fraction: A Tale of Mice, Rats, and Cats

Heart failure with preserved ejection fraction (HFpEF) remains a medical anomaly that baffles researchers and physicians alike. The overall phenotypical changes of diastolic function and left ventricular hypertrophy observed in HFpEF are definable; however, the metabolic and molecular alterations that ultimately produce these changes are not well established. Comorbidities such as obesity, hypertension, and diabetes, as well as general aging, play crucial roles in its development and progression. Various animal models have recently been developed to better understand the pathophysiological and metabolic developments in HFpEF and to illuminate novel avenues for pharmacotherapy. These models include multi‐hit rodents and feline aortic constriction animals. Recently, genomic, proteomic, and metabolomic approaches have been used to define altered signaling pathways in the heart associated with HFpEF, including those involved in inflammation, cGMP‐related, Ca²⁺ handling, mitochondrial respiration, and the unfolded protein response in endoplasmic reticulum stress. This article aims to present an overview of what has been learnt by these studies, focusing mainly on the findings in common while highlighting unresolved issues. The knowledge gained from these research models will not simply be of benefit for treating HFpEF but will undoubtedly provide new insights into the mechanisms by which the heart deals with external stresses and how the processes involved can fail.

Empagliflozin mitigates endothelial inflammation and attenuates endoplasmic reticulum stress signaling caused by sustained glycocalyx disruption

The disruption of the endothelial cell (EC) glycocalyx (GCX) leads to cellular dysfunction promoting inflammation and cardiovascular disease progression. Recent studies have shown that empagliflozin (EMPA; Jardiance), a sodium-glucose cotransporter 2 inhibitor used in the treatment of type 2 diabetes, can improve EC functions impacted by GCX disruption although the exact cellular mechanisms remain to be elucidated. In this study, the effect of EMPA on EC inflammatory response induced by sustained GCX disruption was investigated. Human aortic ECs were cultured under shear (10 dyne/cm²) for 24 h with or without sustained degradation of heparan sulfate (HS). HS degradation increased inflammatory cell adhesion to ECs. EMPA (50 μM) normalized adhesion levels under sustained HS degradation. Protein expressions of eNOS, phospho-eNOS Ser1177 and ICAM-1 remained unchanged between conditions. Transcriptome analysis revealed the induction of the unfolded protein response (UPR) through the increased expression of ATF3, ATF4, DDIT3 (CHOP), EIF2AK3 (PERK), HSPA5 (Grp78), PPP1R15A (GADD34) and TRIB3 which was in part downregulated by EMPA. mRNA and protein expression of thioredoxin interacting protein (TXNIP) was also downregulated by EMPA. Mitigation of oxidative stress with N-Acetyl-L-cysteine resulted in similar reduction in inflammatory cell adhesion compared to EMPA which could indicate a potential mechanism by which EMPA normalized the inflammatory response. In conclusion, this study demonstrated the potential of EMPA to resolve the inflammatory response of ECs caused by sustained GCX disruption while altering UPR signaling under endoplasmic reticulum stress.

Sodium-glucose cotransporter 2 inhibitors as the first universal treatment of chronic kidney disease

In the last five years, the medical community was astonishingly surprised by the sequential large outcome trials that displayed the renal effects of sodium glucose co-transporter inhibitors (SGLT2Is) in type 2 diabetes mellitus (T2DM) patients with or without chronic kidney disease (CKD). This favorable effect was later disclosed in non-diabetic CKD patients. The EMPA-REG OUTCOME trial was the first trial that showed a reduction for the need for dialysis in patients suffering diabetic kidney disease (DKD) by 55%. This figure is double the score achieved by the angiotensin receptor blocker, Losartan, in RENAAL trial. The need for dialysis in DAPA-CKD trial was reduced in diabetic and non-diabetic CKD patients by 33%. The renal-specific composite outcome was reduced by 39% in EMPA-REG trial, 40% in CANVAS study, 47% in DECLARE-TIMI 58 study, 34% in CREDENCE trial, and 44% in DAPA-CKD trial. The greater surprise is the significant favorable effect of SGLT2Is on overall mortality in CKD patients with or without T2DM. Similar survival benefit was not previously encountered with any of the medications used in CKD patients with or without diabetes. In this review, we disclose the results of the DAPA-CKD trial, the CREDENCE trial and those of several cardiovascular outcome trials (CVOT) that used different SGLT2Is and showed that patients with lower eGFR levels may have greater benefit with respect to cardiovascular morbidity than patients with normal kidney function. In addition, we discuss the different mechanisms of action that explain the renal beneficial effects of SGLT2Is.

Pleiotropic effects of SGLT2 inhibitors and heart failure outcomes

Heart failure (HF) represents a major public health concern with increasing prevalence among aging populations, with multifactorial pathophysiology including inflammation, oxidative stress, endothelial dysfunction, and fibrosis, among others. Lately, the use of sodium-glucose cotransporter-2 (SGLT2) inhibitors, originally destined for the treatment of type 2 diabetes mellitus, have revolutionized the treatment of HF. In this review article, we provide the milestones and the latest mechanistic evidence of SGLT2 inhibition in HF. Owing to the results of experimental studies, several pleiotropic effects of SGLT2 inhibitors have been proposed, including the restoration of autophagy which may be significant in the reversal of the aforementioned HF pathophysiology according to a latest hypotheses. Additional mechanisms consist of the regulation of inflammatory, oxidative, and fibrotic pathways, together with the improvement of endothelial function and reduction of epicardial adipose tissue. Other than their role as antidiabetic agents, a reduction in heart failure hospitalizations has been noted following their use in clinical trials, irrespective of DM status and degree of systolic dysfunction. Upcoming randomized trials are expected to additional clinical and mechanistic evidence regarding the diverse effects of SGLT2 inhibition across the spectrum of heart failure.

Mimicking Metabolic Disturbance in Establishing Animal Models of Heart Failure With Preserved Ejection Fraction

Heart failure (HF), the terminal state of different heart diseases, imposed a significant health care burden worldwide. It is the last battlefield in dealing with cardiovascular diseases. HF with preserved ejection fraction (HFpEF) is a type of HF in which the symptoms and signs of HF are mainly ascribed to diastolic dysfunction of left ventricle, whereas systolic function is normal or near-normal. Compared to HF with reduced ejection fraction (HFrEF), the diagnosis and treatment of HFpEF have made limited progress, partly due to the lack of suitable animal models for translational studies in the past. Given metabolic disturbance and inflammatory burden contribute to HFpEF pathogenesis, recent years have witnessed emerging studies focusing on construction of animal models with HFpEF phenotype by mimicking metabolic disorders. These models prefer to recapitulate the metabolic disorders and endothelial dysfunction, leading to the more detailed understanding of the entity. In this review, we summarize the currently available animal models of HFpEF with metabolic disorders, as well as their advantages and disadvantages as tools for translational studies.

An Effective Sodium-Dependent Glucose Transporter 2 Inhibition, Canagliflozin, Prevents Development of Hypertensive Heart Failure in Dahl Salt-Sensitive Rats

Background: The aim of the study was to investigate the protective effect of canagliflozin (CANA) on myocardial metabolism and heart under stress overload and to further explore its possible molecular mechanism.

Methods: High-salt diet was used to induce heart failure with preserved ejection fraction (HFpEF), and then, the physical and physiological indicators were measured. The cardiac function was evaluated by echocardiography and related indicators. Masson trichrome staining, wheat germ agglutinin, and immunohistochemical staining were conducted for histology analysis. Meanwhile, oxidative stress and cardiac ATP production were also determined. PCR and Western blotting were used for quantitative detection of related genes and proteins. Comprehensive metabolomics and proteomics were employed for metabolic analysis and protein expression analysis.

Results: In this study, CANA showed diuretic, hypotensive, weight loss, and increased intake of food and water. Dahl salt-sensitive (DSS) rats fed with a diet containing 8% NaCl AIN-76A developed left ventricular remodeling and diastolic dysfunction caused by hypertension. After CANA treatment, cardiac hypertrophy and fibrosis were reduced, and the left ventricular diastolic function was improved. Metabolomics and proteomics data confirmed that CANA reduced myocardial glucose metabolism and increased fatty acid metabolism and ketogenesis in DSS rats, normalizing myocardial metabolism and reducing the myocardial oxidative stress. Mechanistically, CANA upregulated p-adenosine 5′-monophosphate-activated protein kinase (p-AMPK) and sirtuin 1 (SIRT1) and significantly induced the expression of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1a).

Conclusion: CANA can improve myocardial hypertrophy, fibrosis, and left ventricular diastolic dysfunction induced by hypertension in DSS rats, possibly through the activation of the AMPK/SIRT1/PGC-1a pathway to regulate energy metabolism and oxidative stress.

CX3CL1 Worsens Cardiorenal Dysfunction and Serves as a Therapeutic Target of Canagliflozin for Cardiorenal Syndrome

The prognosis of cardiorenal dysfunction induced by diabetes mellitus (DM), which belongs to cardiorenal syndrome type 5, is poor and its pathogenesis remains elusive. We have reported that CX3CL1 exacerbated heart failure and direct inhibition of CX3CL1 improved cardiac function. Emerging evidence supports that CX3CL1 is involved in renal impairment. Here we attempt to clarify whether CX3CL1 might be a therapeutic target for cardiorenal dysfunction in diabetes. We found that cardiac and renal CX3CL1 protein levels were significantly increased in both streptozotocin-induced diabetic mice and in non-obese diabetic mice, and that hyperglycemia led to persistent CX3CL1 expression in the heart and kidneys even after it was controlled by insulin. In cultured cardiac and renal cells, soluble CX3CL1 accelerated mitochondrial-dependent apoptosis via activation of the RhoA/ROCK1-Bax signaling pathway and promoted fibrosis through cellular phenotypic trans-differentiation mediated by the TGF-β/Smad pathway. In the two diabetic mouse models, knockout of CX3CL1 receptor CX3CR1 or treatment with an CX3CL1 neutralizing antibody significantly improved cardiorenal dysfunction by inhibiting apoptosis, mitochondrial dysfunction, and fibrosis. Moreover, sodium glucose cotransporter 2 inhibitor canagliflozin significantly downregulated cardiac and renal CX3CL1 expression and improved cardiorenal dysfunction. These findings indicate that CX3CL1 could be a new therapeutic target for diabetes-induced cardiorenal dysfunction.

Emerging Roles of Sodium Glucose Cotransporter 2 (SGLT-2) Inhibitors in Diabetic Cardiovascular Diseases: Focusing on Immunity, Inflammation and Metabolism

Diabetes mellitus (DM) is one of the most fast evolving global issues characterized by hyperglycemia. Patients with diabetes are considered to face with higher risks of adverse cardiovascular events. Those are the main cause of mortality and disability in diabetes patients. There are novel antidiabetic agents that selectively suppress sodium-glucose cotransporter-2 (SGLT-2). They work by reducing proximal tubule glucose reabsorption. Although increasing evidence has shown that SGLT-2 inhibitors can contribute to a series of cardiovascular benefits in diabetic patients, including a reduced incidence of major adverse cardiovascular events and protection of extracardiac organs, the potential mechanisms of SGLT2 inhibitors’ cardiovascular protective effects are still not fully elucidated. Given the important role of inflammation and metabolism in diabetic cardiovascular diseases, this review is intended to rationally compile the multifactorial mechanisms of SGLT-2 inhibitors from the point of immunity, inflammation and metabolism, depicting the fundamental cellular and molecular processing of SGLT-2 inhibitors exerting regulating immunity, inflammation and metabolism. Finally, future directions and perspectives to prevent or delay cardiovascular complications in DM by SGLT-2 inhibitors are presented.

Sodium-Glucose Cotransporter 2 Inhibitors and Cardiac Remodeling

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have evident cardiovascular benefits in patients with type 2 diabetes with or at high risk for atherosclerotic cardiovascular disease, heart failure with reduced ejection fraction, heart failure with preserved ejection fraction (only empagliflozin and dapagliflozin have been investigated in this group so far), and chronic kidney disease. Prevention and reversal of adverse cardiac remodeling is one of the mechanisms by which SGLT2 inhibitors may exert cardiovascular benefits, especially heart failure-related outcomes. Cardiac remodeling encompasses molecular, cellular, and interstitial changes that result in favorable changes in the mass, geometry, size, and function of the heart. The pathophysiological mechanisms of adverse cardiac remodeling are related to increased apoptosis and necrosis, decreased autophagy, impairments of myocardial oxygen supply and demand, and altered energy metabolism. Herein, the accumulating evidence from animal and human studies is reviewed investigating the effects of SGLT2 inhibitors on these mechanisms of cardiac remodeling.

Effects of soluble guanylate cyclase stimulator on renal function in ZSF-1 model of diabetic nephropathy

BACKGROUND

Diabetic nephropathy is associated with endothelial dysfunction and oxidative stress, in which the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate (NO-sGC-cGMP) signaling pathway is impaired. We hypothesize that sGC stimulator Compound 1 can enhance NO signaling, reduce proteinuria in a diabetic nephropathy preclinical model with diminished NO bioavailability and increased oxidized sGC. Therefore, we evaluated the effect of sGC stimulator Compound 1 on the renal effect in obese ZSF1 (ZSF1 OB) rats.

MATERIALS AND METHODS

The sGC stimulator Compound 1, the standard of care agent Enalapril, and a combination of Compound 1 and Enalapril were administered chronically to obese ZSF1 rats for 6 months. Mean arterial pressure, heart rate, creatinine clearance for glomerular filtration rate (eGFR), urinary protein excretion to creatinine ratio (UPCR), and urinary albumin excretion ratio (UACR) were determined during the study. The histopathology of glomerular and interstitial lesions was assessed at the completion of the study.

RESULTS

While both Compound 1 and Enalapril significantly reduced blood pressure, the combination of Compound 1 and Enalapril normalized blood pressure levels. Compound 1 improved eGFR and reduced UPCR and UACR. A combination of Enalapril and Compound 1 resulted in a marked reduction in UPCR and UACR and improved GFR.

CONCLUSION

The sGC stimulator Compound 1 as a monotherapy slowed renal disease progression, and a combination of the sGC stimulator with Enalapril provided greater renal protection in a rodent model of diabetic nephropathy.

A G-protein-biased S1P1 agonist, SAR247799, improved LVH and diastolic function in a rat model of metabolic syndrome

Aim

Heart failure with preserved ejection fraction (HFpEF) is a major cause of death worldwide with no approved treatment. Left ventricular hypertrophy (LVH) and diastolic dysfunction represent the structural and functional components of HFpEF, respectively. Endothelial dysfunction is prevalent in HFpEF and predicts cardiovascular events. We investigated if SAR247799, a G-protein-biased sphingosine-1-phosphate receptor 1 (S1P1) agonist with endothelial-protective properties, could improve cardiac and renal functions in a rat model of metabolic syndrome LVH and diastolic function.

Methods

31- and 65-week-old obese ZSF1 (Ob-ZSF1) rats, representing adult and aged animals with LVH and diastolic dysfunction, were randomized to a chow diet containing 0.025% (w/w) of SAR247799, or control (CTRL) chow for 4 weeks. Age-matched lean ZSF1 (Le-ZSF1) rats were fed control chow. Echocardiography, telemetry, biochemical and histological analysis were performed to evaluate the effect of SAR247799.

Results

Echocardiography revealed that Ob-ZSF1 rats, in contrast to Le-ZSF1 rats, developed progressive diastolic dysfunction and cardiac hypertrophy with age. SAR247799 blunted the progression of diastolic dysfunction in adult and aged animals: in adult animals E/e’ was evaluated at 21.8 ± 1.4 for Ob-ZSF1-CTRL, 19.5 ± 1.2 for Ob-ZSF1-SAR247799 p<0.01, and 19.5 ± 2.3 for Le-ZSF1-CTRL (median ± IQR). In aged animals E/e’ was evaluated at 23.15 ± 4.45 for Ob-ZSF1-CTRL, 19.5 ± 5 for Ob-ZSF1-SAR247799 p<0.01, and 16.69 ± 1.7 for Le-ZSF1-CTRL, p<0.01 (median ± IQR). In aged animals, SAR247799 reduced cardiac hypertrophy (g/mm mean ± SEM of heart weight/tibia length 0.053 ± 0.001 for Ob-ZSF1-CTRL vs 0.046 ± 0.002 for Ob-ZSF1-SAR247799 p<0.01, Le-ZSF1-CTRL 0.035 ± 0.001) and myocardial perivascular collagen content (p<0.001), independently of any changes in microvascular density. In adult animals, SAR247799 improved endothelial function as assessed by the very low frequency bands of systolic blood pressure variability (mean ± SEM 67.8 ± 3.41 for Ob-ZSF1-CTRL 55.8 ± 4.27 or Ob-ZSF1-SAR247799, p<0.05 and 57.3 ± 1.82 Le-ZSF1-CTRL), independently of any modification of arterial blood pressure. In aged animals, SAR247799 reduced urinary protein/creatinine ratio, an index of glomerular injury, (10.3 ± 0.621 vs 8.17 ± 0.231 for Ob-ZSF1-CTRL vs Ob-ZSF1-SAR247799, respectively, p<0.05 and 0.294 ± 0.029 for Le-ZSF1-CTRL, mean ± SEM) and the fractional excretion of electrolytes. Circulating lymphocytes were not decreased by SAR247799, confirming lack of S1P1 desensitization.

Conclusions

These experimental findings suggest that S1P1 activation with SAR247799 may be considered as a new therapeutic approach for LVH and diastolic dysfunction, major components of HFpEF.

The Effects of the New Therapeutic Treatments for Diabetes Mellitus on the Male Reproductive Axis

One of the complications of chronic hyperglycemia and insulin resistance due to type 2 diabetes mellitus (T2DM) on the hypothalamic-pituitary-gonadal axis in men, is the high prevalence of hypogonadotropic hypogonadism, which has been recently defined as functional hypogonadism, characterized by low testosterone associated with inappropriately normal gonadotropin levels. Although the pathophysiology of this hormonal imbalance may be related to several factors, including glycemic control, concomitant sleep apnea, insulin resistance, the main role is determined by the degree of central or visceral obesity and the consequent inflammatory state. Several drugs have been developed to treat T2DM such as glucagon-like peptide-1 receptor agonists, dipeptidyl peptidase 4 inhibitors, and sodium-glucose co-transporter 2 inhibitors. All appear to be effective in ameliorating blood glucose control, by lowering inflammation and body weight, and most seem to reduce the risk of micro- and macrovascular damage as a consequence of uncontrolled diabetes. A few studies have evaluated the impact of these drugs on gonadal function in T2DM patients with hypogonadism, with promising results. This review summarizes the main current knowledge of the effects of these new antidiabetic drugs on the hypothalamus-pituitary-gonadal axis, showing their potential future application in addition to glucose control in dysmetabolic male patients.

Effects of SGLT-2 Inhibitors on Vascular Endothelial Function and Arterial Stiffness in Subjects With Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

This systematic review and meta-analysis aimed to evaluate the effects of SGLT-2 inhibitors (SGLT-2i) on endothelial function and arteriosclerosis in diabetic patients.

METHODS

Randomized controlled trials (RCTs) were retrieved from PubMed, Embase, Cochrane Library, and Web of Science databases to evaluate the effects of SGLT-2i on endothelial function and atherosclerosis in type 2 diabetic patients.

RESULTS

We selected 9 RCTs and 2 cohort studys involving 868 patients. Of these, six studies provided flow-mediated dilation (FMD) levels before and after the intervention. The pooled analysis showed that SGLT-2i could significantly improve the FMD compared to the control group (SMD: 0.18, 95% CI: 0.02 ~ 0.34, P = 0.03). Three studies provided the change in FMD before and after the intervention. Pooled analysis showed no significant differences in FMD change between the SGLT-2i group and the control group. (MD: 2.1, 95%-CI: -0.11~4.31, P = 0.06). Five studies showed pulse wave velocity (PWV) results. Pooled analysis showed no significant differences in the change in PWV between the SGLT-2i group and the control group (SMD: 0.11, 95%-CI: - 0.15 ~ 0.37, P = 0.4).

CONCLUSIONS

The ability of SGLT-2 inhibitors to improve FMD was significant, but there was no significant effect on PWV levels. SGLT-2i was superior to other antidiabetic agents in improving arterial endothelial function.

Effect of empagliflozin on ketone bodies in patients with stable chronic heart failure

Background

Recent studies indicated that sodium glucose cotransporter (SGLT)2 inhibition increases levels of ketone bodies in the blood in patients with type 1 and 2 diabetes. Other studies suggested that in patients with chronic heart failure (CHF), increased myocardial oxygen demand can be provided by ketone bodies as a fuel substrate. Experimental studies reported that ketone bodies, specifically beta-hydroxybutyrate (β-OHB) may increase blood pressure (BP) by impairing endothelium-dependant relaxation, thereby leading to increased vascular stiffness. In our study we assessed whether the SGLT 2 inhibition with empagliflozin increases ketone bodies in patients with stable CHF and whether such an increase impairs BP and vascular function.

Methods

In a prospective, double blind, placebo controlled, parallel-group single centre study 75 patients with CHF (left ventricular ejection fraction 39.0 ± 8.2%) were randomised (2:1) to the SGLT-2 inhibitor empagliflozin 10 mg orally once daily or to placebo, 72 patients completed the study. After a run-in phase we evaluated at baseline BP by 24 h ambulatory blood pressure (ABP) monitoring, vascular stiffness parameters by the SphygmoCor system (AtCor Medical, Sydney, NSW, Australia) and fasting metabolic parameters, including β-OHB by an enzymatic assay (Beckman Coulter DxC 700 AU). The same measurements were repeated 12 weeks after treatment. In 19 of the 72 patients serum levels of β-OHB were beneath the lower border of our assay (< 0.05 mmol/l) therefore being excluded from the subsequent analysis.

Results

In patients with stable CHF, treatment with empagliflozin (n = 36) was followed by an increase of β-OHB by 33.39% (p = 0.017), reduction in 24 h systolic (p = 0.038) and diastolic (p = 0.085) ABP, weight loss (p = 0.003) and decrease of central systolic BP (p = 0.008) and central pulse pressure (p = 0.008). The increase in β-OHB was related to an attenuated decrease of empagliflozin-induced 24 h systolic (r = 0.321, p = 0.069) and diastolic (r = 0.516, p = 0.002) ABP and less reduction of central systolic BP (r = 0.470, p = 0.009) and central pulse pressure (r = 0.391, p = 0.033). No significant changes were seen in any of these parameters after 12 weeks of treatment in the placebo group (n = 17).

Conclusion

In patients with stable CHF ketone bodies as assessed by β-OHB increased after treatment with empagliflozin. This increase led to an attenuation of the beneficial effects of empagliflozin on BP and vascular parameters.

Trial registration The study was registered at http://www.clinicaltrials.gov (NCT03128528).

Empagliflozin protects the heart against ischemia/reperfusion-induced sudden cardiac death

BACKGROUND

Empagliflozin is a selective sodium-glucose cotransporter 2 (SGLT2) inhibitor used to lower blood sugar in adults with type 2 diabetes. Empagliflozin also exerts cardioprotective effects independent from glucose control, but its benefits on arrhythmogenesis and sudden cardiac death are not known. The purpose of this study was to examine the effect of empagliflozin on myocardial ischemia/reperfusion-provoked cardiac arrhythmia and sudden cardiac death in vivo.

METHODS

Male Sprague Dawley rats were randomly assigned to sham-operated, control or empagliflozin groups. All except for the sham-operated rats were subjected to 5-min left main coronary artery ligation followed by 20-min reperfusion. A standard limb lead II electrocardiogram was continuously measured throughout the experiment. Coronary artery reperfusion-induced ventricular arrhythmogenesis and empagliflozin therapy were evaluated. The hearts were used for protein phosphorylation analysis and immunohistological assessment.

RESULTS

Empagliflozin did not alter baseline cardiac normal conduction activity. However, empagliflozin eliminated myocardial vulnerability to sudden cardiac death (from 69.2% mortality rate in the control group to 0% in the empagliflozin group) and reduced the susceptibility to reperfusion-induced arrhythmias post I/R injury. Empagliflozin increased phosphorylation of cardiac ERK1/2 after reperfusion injury. Furthermore, inhibition of ERK1/2 using U0126 abolished the anti-arrhythmic action of empagliflozin and ERK1/2 phosphorylation.

CONCLUSIONS

Pretreatment with empagliflozin protects the heart from subsequent severe lethal ventricular arrhythmia induced by myocardial ischemia and reperfusion injury. These protective benefits may occur as a consequence of activation of the ERK1/2-dependent cell-survival signaling pathway in a glucose-independent manner.