Targeting high glucose-induced epigenetic modifications at cardiac level: the role of SGLT2 and SGLT2 inhibitors

Co-localization of the sodium-glucose co-transporter-2 channel (SGLT-2) with endothelin ETA and ETB receptors in human cardiorenal tissue

Endothelin (ET) receptor antagonists are being investigated in combination with sodium-glucose co-transporter-2 inhibitors (SGLT-2i). These drugs primarily inhibit the SGLT-2 transporter that, in humans, is thought to be mainly restricted to the renal proximal convoluted tubule, resulting in increased glucose excretion favouring improved glycaemic control and diuresis. This action reduces fluid retention with ET receptor antagonists. Studies have suggested SGLT-2 may also be expressed in cardiomyocytes of human heart. To understand the potential of combining the two classes of drugs, our aim was to compare the distribution of ET receptor sub-types in human kidney, with SGLT-2. Secondly, using the same experimental conditions, we determined if SGLT-2 expression could be detected in human heart and whether the transporter co-localised with ET receptors.

METHODS

Immunocytochemistry localised SGLT-2, ETA and ETB receptors in sections of histologically normal kidney, left ventricle from patients undergoing heart transplantation or controls. Primary antisera were visualised using fluorescent microscopy. Image analysis was used to measure intensity compared with background in adjacent control sections.

RESULTS

As expected, SGLT-2 localised to epithelial cells of the proximal convoluted tubules, and co-localised with both ET receptor sub-types. Similarly, ETA receptors predominated in cardiomyocytes; low (compared with kidney but above background) positive staining was also detected for SGLT-2.

DISCUSSION

Whether low levels of SGLT-2 have a (patho)physiological role in cardiomyocytes is not known but results suggest the effect of direct blockade of sodium (and glucose) influx via SGLT-2 inhibition in cardiomyocytes should be explored, with potential for additive effects with ETA antagonists.

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.

Recent Updates on Epigenetic-Based Pharmacotherapy for Atherosclerosis

Atherosclerosis is one of the most dominant pathological processes responsible in cardiovascular diseases (CVD) caused by cholesterol accumulation accompanied by inflammation in the arteries which will subsequently lead to further complications, including myocardial infarction and stroke. Although the incidence of atherosclerosis is decreasing in some countries, it is still considered the leading cause of death worldwide. Atherosclerosis is a vascular pathological process that is chronically inflammatory and is characterized by the invasion of inflammatory cells and cytokines. Many reports have unraveled the pivotal roles of epigenetics such as DNA methylation, post-translational histone modifications, and non-coding RNAs (ncRNAs) in atherogenesis, which regulate the expression of numerous genes related to various responsible pathways. Many studies have been conducted to develop new therapeutical approaches based on epigenetic changes for combating atherosclerosis. This review elaborates on recent updates on the development of new atherosclerosis drugs whose mechanism of action is associated with the modulation of DNA methylation, posttranslational histone modifications, and ncRNA-based gene regulation.

The latest emerging drugs for the treatment of diabetic cardiomyopathy

INTRODUCTION

Diabetic cardiomyopathy (DCM) is a serious complication of diabetes mellitus involving multiple pathophysiologic mechanisms. In addition to hypoglycemic agents commonly used in diabetes, metabolism-related drugs, natural plant extracts, melatonin, exosomes, and rennin-angiotensin-aldosterone system are cardioprotective in DCM. However, there is a lack of systematic summarization of drugs for DCM.

AREAS COVERED

In this review, the authors systematically summarize the most recent drugs used for the treatment of DCM and discusses them from the perspective of DCM pathophysiological mechanisms.

EXPERT OPINION

We discuss DCM drugs from the perspective of the pathophysiological mechanisms of DCM, mainly including inflammation and metabolism. As a disease with multiple pathophysiological mechanisms, the combination of drugs may be more advantageous, and we have discussed some of the current studies on the combination of drugs.

The Cardioprotective and Anticancer Effects of SGLT2 Inhibitors: JACC: CardioOncology State-of-the-Art Review

Sodium-glucose cotransporter-2 (SGLT2) inhibitors, originally approved for type 2 diabetes mellitus, have demonstrated efficacy in reducing cardiovascular events, particularly heart failure, in patients with and without diabetes. An intriguing research area involves exploring the potential application of SGLT2 inhibitors in cardio-oncology, aiming to mitigate the cardiovascular adverse events associated with anticancer treatments. These inhibitors present a unique dual nature, offering both cardioprotective effects and anticancer properties, conferring a double benefit for cardio-oncology patients. In this review, the authors first examine the established cardioprotective effects of SGLT2 inhibitors in heart failure and subsequently explore the existing body of evidence, including both preclinical and clinical studies, that supports the use of SGLT2 inhibitors in the context of cardio-oncology. The authors further discuss the mechanisms through which SGLT2 inhibitors protect against cardiovascular toxicity secondary to cancer treatment. Finally, they explore the potential anticancer effects of SGLT2 inhibitors along with their proposed mechanisms.

Emerging role of antidiabetic drugs in cardiorenal protection

The global prevalence of diabetes mellitus (DM) has led to widespread multi-system damage, especially in cardiovascular and renal functions, heightening morbidity and mortality. Emerging antidiabetic drugs sodium-glucose cotransporter 2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP-1RAs), and dipeptidyl peptidase-4 inhibitors (DPP-4i) have demonstrated efficacy in preserving cardiac and renal function, both in type 2 diabetic and non-diabetic individuals. To understand the exact impact of these drugs on cardiorenal protection and underlying mechanisms, we conducted a comprehensive review of recent large-scale clinical trials and basic research focusing on SGLT2i, GLP-1RAs, and DPP-4i. Accumulating evidence highlights the diverse mechanisms including glucose-dependent and independent pathways, and revealing their potential cardiorenal protection in diabetic and non-diabetic cardiorenal disease. This review provides critical insights into the cardiorenal protective effects of SGLT2i, GLP-1RAs, and DPP-4i and underscores the importance of these medications in mitigating the progression of cardiovascular and renal complications, and their broader clinical implications beyond glycemic management.

GLP-1 receptor agonists-SGLT-2 inhibitors combination therapy and cardiovascular events after acute myocardial infarction: an observational study in patients with type 2 diabetes

BACKGROUND

Few studies explored the effect of the combination of glucose sodium-cotransporter-2 inhibitors (SGLT-2i) and glucagon-like peptide-1 receptor agonists (GLP-1RA) on the incidence of cardiovascular events in patients with type 2 diabetes (T2D) and acute myocardial infarction (AMI).

METHODS

We recruited patients with T2D and AMI undergoing percutaneous coronary intervention, treated with either SGLT-2i or GLP-1RA for at least 3 months before hospitalization. Subjects with HbA1c < 7% at admission were considered in good glycemic control and maintained the same glucose-lowering regimen, while those with poor glycemic control (HbA1c ≥ 7%), at admission or during follow-up, were prescribed either a SGLT-2i or a GLP-1RA to obtain a SGLT-2i/GLP-1RA combination therapy. The primary outcome was the incidence of major adverse cardiovascular events (MACE) defined as cardiovascular death, re-acute coronary syndrome, and heart failure related to AMI during a 2-year follow-up. After 3 months, the myocardial salvage index (MSI) was assessed by single-photon emission computed tomography.

FINDINGS

Of the 537 subjects screened, 443 completed the follow-up. Of these, 99 were treated with SGLT-2i, 130 with GLP-1RA, and 214 with their combination. The incidence of MACE was lower in the combination therapy group compared with both SGLT-2i and GLP-1RA treated patients, as assessed by multivariable Cox regression analysis adjusted for cardiovascular risk factors (HR = 0.154, 95% CI 0.038-0.622, P = 0.009 vs GLP-1RA and HR = 0.170, 95% CI 0.046-0.633, P = 0.008 vs SGLT-2i). The MSI and the proportion of patients with MSI > 50% was higher in the SGLT-2i/GLP-1RA group compared with both SGLT-2i and GLP-1RA groups.

INTERPRETATION

The combination of SGLT-2i and GLP-1RA is associated with a reduced incidence of cardiovascular events in patients with T2D and AMI compared with either drug used alone, with a significant effect also on peri-infarcted myocardial rescue in patients without a second event. Trial registraition ClinicalTrials.gov ID: NCT06017544.

LncRNA SNHG8 regulates the migration and angiogenesis of pHUVECs induced by high glucose via the TRPM7/ERK1/2 signaling axis

This study aimed to evaluate the regulatory effect and molecular mechanism of long noncoding RNA small nucleolus RNA host gene 8 (LncRNA SNHG8) in the migration and angiogenesis of primary human umbilical vein endothelial cells (pHUVECs) under high-glucose (HG) conditions. The HG-induced endothelial injury model was established in vitro.The cell model of silencing SNHG8, overexpressing SNHG8, and silencing TRPM7 was established by transfecting SNHG8-siRNA, SNHG8 plasmid and TRPM7-siRNA into cells with liposomes.The SNHG8 level was determined through reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The expression levels of transient receptor potential melastatin 7 (TRPM7), endothelial nitric oxide synthase (eNOS), p-eNOS, extracellular signal-regulated kinase 1/2(ERK1/2), and p-ERK1/2 were assessed through western blot. Nitric oxide (NO) levels were measured with DAF-FM. pHUVEC migration was examined through wound healing and Transwell assay, and pHUVEC angiogenesis was observed through a tube formation assay. Results showed that HG promoted the expression of lncRNA SNHG8 and TRPM7 and decreased the ratio of p-eNOS/eNOS and p-ERK1/2/ERK1/2 in pHUVECs . NO production, migration , and angiogenesis were inhibited in pHUVECs under HG conditions. Silencing lncRNA SNHG8 and TRPM7 could significantly reverse the HG-induced decrease in eNOS activation, NO production , migration, and angiogenesis . SNHG8 and U0126 (ERK pathway inhibitor) overexpression enhanced the HG effects, whereas using U0126 did not affect the TRPM7 expression. In conclusion, lncRNA SNHG8 participates in HG-induced endothelial cell injury and likely regulates NO production, migration, and angiogenesis of pHUVECs via the TRPM7/ERK1/2 signaling axis.

Effects of empagliflozin on right ventricular adaptation to pressure overload

Background

Right ventricular (RV) failure is the prime cause of death in patients with pulmonary arterial hypertension. Novel treatment strategies that protect the RV are needed. Empagliflozin, a sodium-glucose co-transporter-2 inhibitor, shows cardioprotective effects on the left ventricle in clinical and preclinical studies, but its direct effects on RV remain elusive. We investigated the effects of empagliflozin on RV dysfunction induced by pulmonary trunk banding (PTB).

Methods

Male Wistar rats (116 ± 10 g) were randomized to PTB or sham surgery. One week after surgery, PTB animals received empagliflozin mixed into the chow (300 mg empagliflozin/kg chow; PTB-empa, n = 10) or standard chow (PTB-control, n = 10). Sham rats (Sham, n = 6) received standard chow. After five weeks, RV function was evaluated by echocardiography, cardiac MRI, and invasive pressure-volume measurements.

Results

PTB caused RV failure evident by decreased cardiac output compared with sham. PTB-empa rats had a 49% increase in water intake compared with PTB-control yet no differences in hematocrit or blood glucose. Treatment with empagliflozin decreased RV end-systolic pressures without any changes in RV cardiac output or ventricular-arterial coupling (Ees/Ea). The decrease in RV end-systolic pressure was complemented by a slight reduction in RV cross sectional area as a sign of reduced hypertrophy. Load-independent measures of RV systolic and diastolic function were not affected in PTB-empa rats compared with PTB-control.

Conclusion

Empagliflozin treatment reduced RV end-systolic pressure in RV failure induced by pressure overload. Further studies are needed to elucidate whether this simply relates to a diuretic effect and/or additional independent beneficial RV effects.

Dapagliflozin attenuates the vulnerability to atrial fibrillation in rats with lipopolysaccharide-induced myocardial injury

BACKGROUND

Oxidative stress is an essential component participating in the development and maintenance of atrial fibrillation (AF). Dapagliflozin, a SGLT2 inhibitor, has been shown to exert cardioprotective effects by ameliorating oxidative stress in multiple heart disease models. However, its potential to attenuate lipopolysaccharide (LPS)-induced myocardial injury in rats remains unknown.

AIM

This study aims to investigate the role of dapagliflozin in LPS-induced myocardial injury and the potential mechanisms involved.

METHODS

Rats were intraperitoneally administered LPS to induce sepsis-like condition. The intervention was conducted with intraperitoneal injection of dapagliflozin or saline 1 h in advance. The effects of dapagliflozin were detected by electrophysiological recordings, western blot, qPCR, ELISA, HE staining, immunohistochemistry and fluorescence. We further validated the mechanism in vitro using HL-1 cells.

RESULTS

Dapagliflozin significantly improved LPS-induced myocardial injury, reduced susceptibility to AF, and mitigated atrial tissue inflammatory cell infiltration and atrial myocyte apoptosis. These were correlated with the Nrf2/HO-1 signaling pathway, which subsequently reduced oxidative stress. Subsequently, we used a specific inhibitor of the Nrf2/HO-1 pathway in vitro, reversed the anti-oxidative stress effects of dapagliflozin on HL-1 cells, further confirming the Nrf2/HO-1 pathway's pivotal role in dapagliflozin-mediated cardioprotection.

CONCLUSION

Dapagliflozin ameliorated myocardial injury and susceptibility to AF induced by LPS through anti-oxidative stress, which relied on upregulation of the Nrf2/HO-1 pathway.

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.

Biomarkers for Assessing Non-Alcoholic Fatty Liver Disease in Patients with Type 2 Diabetes Mellitus on Sodium-Glucose Cotransporter 2 Inhibitor Therapy

In the current modern era of unhealthy lifestyles, non-alcoholic fatty liver disease (NAFLD) is the most prevalent liver disease and has become a serious global health problem. To date, there is no approved pharmacotherapy for the treatment of NAFLD, and necessary lifestyle changes such as weight loss, diet, and exercise are usually not sufficient to manage this disease. Patients with type 2 diabetes mellitus (T2DM) have a significantly higher risk of developing NAFLD and vice versa. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are antidiabetic agents that have recently been approved for two other indications: chronic kidney disease and heart failure in diabetics and non-diabetics. They are also emerging as promising new agents for NAFLD treatment, as they have shown beneficial effects on hepatic inflammation, steatosis, and fibrosis. Studies in animals have reported favorable effects of SGLT2 inhibitors, and studies in patients also found positive effects on body mass index (BMI), insulin resistance, glucose levels, liver enzymes, apoptosis, and transcription factors. There are some theories regarding how SGLT2 inhibitors affect the liver, but the exact mechanism is not yet fully understood. Therefore, biomarkers to evaluate underlying mechanisms of action of SGLT2 inhibitors on the liver have now been scrutinized to assess their potential as a future in-label therapy for NAFLD. In addition, finding suitable non-invasive biomarkers could be helpful in clinical practice for the early detection of NAFLD in patients. This is crucial for a positive disease outcome. The aim of this review is to provide an overview of the most recent findings on the effects of SGLT2 inhibitors on NAFLD biomarkers and the potential of SGLT2 inhibitors to successfully treat NAFLD.

Multi-omics analysis reveals attenuation of cellular stress by empagliflozin in high glucose-treated human cardiomyocytes

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) inhibitors constitute the gold standard treatment for type 2 diabetes mellitus (T2DM). Among them, empagliflozin (EMPA) has shown beneficial effects against heart failure. Because cardiovascular diseases (mainly diabetic cardiomyopathy) are the leading cause of death in diabetic patients, the use of EMPA could be, simultaneously, cardioprotective and antidiabetic, reducing the risk of death from cardiovascular causes and decreasing the risk of hospitalization for heart failure in T2DM patients. Interestingly, recent studies have shown that EMPA has positive benefits for people with and without diabetes. This finding broadens the scope of EMPA function beyond glucose regulation alone to include a more intricate metabolic process that is, in part, still unknown. Similarly, this significantly increases the number of people with heart diseases who may be eligible for EMPA treatment.

METHODS

This study aimed to clarify the metabolic effect of EMPA on the human myocardial cell model by using orthogonal metabolomics, lipidomics, and proteomics approaches. The untargeted and multivariate analysis mimicked the fasting blood sugar level of T2DM patients (hyperglycemia: HG) and in the average blood sugar range (normal glucose: NG), with and without the addition of EMPA.

RESULTS

Results highlighted that EMPA was able to modulate and partially restore the levels of multiple metabolites associated with cellular stress, which were dysregulated in the HG conditions, such as nicotinamide mononucleotide, glucose-6-phosphate, lactic acid, FA 22:6 as well as nucleotide sugars and purine/pyrimidines. Additionally, EMPA regulated the levels of several lipid sub-classes, in particular dihydroceramide and triacylglycerols, which tend to accumulate in HG conditions resulting in lipotoxicity. Finally, EMPA counteracted the dysregulation of endoplasmic reticulum-derived proteins involved in cellular stress management.

CONCLUSIONS

These results could suggest an effect of EMPA on different metabolic routes, tending to rescue cardiomyocyte metabolic status towards a healthy phenotype.

The legacy effect of hyperglycemia and early use of SGLT-2 inhibitors: a cohort study with newly-diagnosed people with type 2 diabetes

Background

A delay in reaching HbA1c targets in patients with newly-diagnosed type 2 diabetes (T2D) is associated with an increased long-term risk of developing cardiovascular diseases (CVD), a phenomenon referred to as legacy effect. Whether an early introduction of glucose-lowering drugs with proven benefit on CVD can attenuate this phenomenon is unknown.

Methods

Using data derived from a large Italian clinical registry, i.e. the AMD Annals, we identified 251,339 subjects with newly-diagnosed T2D and without CVD at baseline. Through Cox regressions adjusted for multiple risk factors, we examined the association between having a mean HbA1c between 7.1 and 8% or >8%, compared with ≤7%, for various periods of early exposure (0-1, 0-2, 0-3 years) and the development of later (mean subsequent follow-up 4.6 ± 2.9 years) CVD, evaluated as a composite of myocardial infarction, stroke, coronary or peripheral revascularization, and coronary or peripheral bypass. We performed this analysis in the overall cohort and then splitting the population in two groups of patients: those that introduced sodium-glucose transport protein 2 inhibitors (SGLT-2i) during the exposure phase and those not treated with these drugs.

Findings

Considering the whole cohort, subjects with both a mean HbA1c between 7.1 and 8% and >8%, compared with patients attaining a mean HbA1c ≤ 7%, showed an increased risk of developing the outcome in all the three early exposure periods assessed, with the highest risk observed in patients with mean HbA1c > 8% in the 3 years exposure period (hazard ratio [HR]1.33; 95% confidence interval [CI] 1.063-1.365). The introduction of SGLT-2i during the exposure periods of 0-1 and 0-2 years eliminated the association between poor glycemic control and the outcome (p for interaction 0.006 and 0.003, respectively, vs. patients with the same degree of glycemic control but not treated with these drugs).

Interpretation

Among patients with newly diagnosed T2D and free of CVD at baseline, a poor glycemic control in the first three years after diagnosis is associated with an increased subsequent risk of CVD. This association is no longer evident when SGLT-2i are introduced in the first two years, suggesting that these drugs attenuate the phenomenon of legacy effect. An early treatment with these drugs might thus promote a long-lasting benefit in patients not attaining proper glycemic control after T2D diagnosis.

Funding

This work was supported, in part, by the Italian Ministry of Health (Ricerca Corrente) to IRCCS MultiMedica.

Impact of SGLT2-inhibitors on contrast-induced acute kidney injury in Diabetic patients with Acute Myocardial Infarction with and without chronic kidney disease: Insight from SGLT2-I AMI PROTECT Registry

AIMS

To analyze the association between chronic SGLT2-I treatment and development of contrast-induced acute kidney injury (CI-AKI) in diabetic patients with acute myocardial infarction (AMI) undergoing PCI.

METHODS

Multicenter international registry of consecutive patients with type 2 diabetes mellitus (T2DM) and AMI undergoing PCI between 2018-2021. The study population was stratified by the presence of chronic kidney disease (CKD) and anti-diabetic therapy at admission (SGLT2-I versus non-SGLT2-I users).

RESULTS

The study population consisted of 646 patients: 111 SGLT2-I users [28 (25.2%) with CKD] and 535 non-SGLT2-I users [221 (41.3%) with CKD]. The median age was 70 [61-79] years. SGLT2-I users exhibited significantly lower creatinine values at 72h after PCI, both in the non-CKD and CKD stratum. The rate of CI-AKI was 76 (11.8%), significantly lower in SGLT2-I users compared to non-SGLT2-I patients (5.4% vs 13.1%, p=0.022). This finding was also confirmed in patients without CKD (p=0.040). In the CKD cohort, SGLT2-I users maintained significantly lower creatinine values at discharge. The use of SGLT2-I was an independent predictor of reduced rate of CI-AKI (OR 0.356; 95%CI 0.134-0.943, p=0.038).

CONCLUSION

In T2DM patients with AMI, the use of SGLT2-I was associated with a lower risk of CI-AKI, mostly in patients without CKD.

Sodium-Glucose Cotransporter 2 (SGLT2) Inhibitors: Harms or Unexpected Benefits?

There is a need for innovative pharmaceutical intervention in light of the increasing prevalence of metabolic disease and cardiovascular disease. The kidneys' sodium-glucose cotransporter 2 inhibitors (SGLT2) receptors are targeted to reduce glucose reabsorption by SGLT2. Patients with type 2 diabetes mellitus (T2DM) benefit the most from reduced blood glucose levels, although this is just one of the numerous physiological consequences. To establish existing understanding and possible advantages and risks for SGLT2 inhibitors in clinical practice, this article will explore the influence of SGLT2 inhibitors on six major organ systems. In addition, this literature review will discuss the benefits and potential drawbacks of SGLT2 inhibitors on various organ systems and their potential application in therapeutic settings.