Early administration of empagliflozin preserved heart function in cardiorenal syndrome in rat

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.

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.

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.

Repeated administration of adipose-derived mesenchymal stem cells added on beneficial effects of empagliflozin on protecting renal function in diabetic kidney disease rat

BACKGROUND

Diabetic kidney disease (DKD) is one of the most significant public health burdens worldwide. This study explored the renal protections of combined adipose-derived mesenchymal stem cells (ADMSCs) and empagliflozin (EMPA) in DKD rats.

METHODS

Adult-male-SD rats were equally allocated into group 1 (sham-operated-control), group 2 (DKD), group 3 (DKD + EMPA/20 mg/kg/day since day-14 after CKD-induction), group 4 [DKD + ADMSCs (6.0 × 105/intrarenal-arterial-injection/post-day-28, followed by 1.2 × 106/intravenous injection post-days 35 and 42 after CKD-induction, i.e., defined as repeated administration)] and group 5 (DKD + ADMSCs + EMPA) and kidney was harvested post-day-60 CKD-induction.

RESULTS

The result showed that the blood sugar and circulatory levels of BUN/creatinine and the ratio of urine protein/creatinine at day 60 were greatly increased in group 2 as compared the SC (i.e., group 1), significantly increased in groups 3 and 4 than in groups 5, but these parameters showed the similar manner in groups 3 and 4, except for blood sugar that was significantly lower in group 3 than in group 4 (all p < 0.0001). The protein levels of inflammation (NF-κB/FNF-α/MMP-9)/oxidative-stress (NOX-1/NOX-2/oxidized protein/p22-phox)/apoptosis (cleaved-caspase-3/cleaved-PARP/mitochondrial-Bax)/fibrosis (TGF-β/Smad 3)/mitochondrial/DNA-damaged (p-DRP1/γ-H2AX) biomarkers revealed a similar manner of creatinine level among the groups (all p < 0.0001). Kidney injury score/fibrotic area/oxidative-stress score (8-OHdG) and cellular levels of kidney-damaged biomarkers (KIM-1/γ-H2AX) showed a unanimous manner. In contrast, the cellular expressions of podocyte components (ZO-1/synaptopodin) revealed an antithetical manner of creatinine among the groups (all p < 0.0001).

CONCLUSION

Combined ADMSCs-EMPA was superior to just one therapy for protecting kidney function and ultra-structural integrity in DKD rodents.

The cardioprotective potential of sodium-glucose cotransporter 2-inhibitors in breast cancer therapy-related cardiac dysfunction - A systematic review

BACKGROUND

Sodium-glucose cotransporter 2-inhibitors (SGLT2i) improve cardiovascular outcomes including reduction in risk of first hospitalisation for heart failure (HF), worsening HF and cardiovascular death regardless of HF or diabetes mellitus (DM) status. It is not known whether SGLT2i can prevent the development of incident HF or reduce the risk of HF in patients receiving trastuzumab with or without other concurrent anti-HER2 agent or sequential anthracycline for treatment of HER2 positive breast cancer. Patients with active malignancy or recent history of malignancy were excluded from participating in the main cardiovascular outcome trials involving SGLT2i.

AIM

A systematic review was performed to objectively assess published literature on the cardioprotective effects of SGLT2i in breast cancer treatment-related cardiotoxicity.

METHODS

Systematic searches of Embase, Medline, The Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov databases were performed. Titles and abstracts were screened separately by two cardio-oncologists (JHC, WTC). Full texts of potentially eligible records were then assessed separately by JHC and WTC before inclusion into review upon joint agreement.

RESULTS

479 records were identified from 3 databases (MEDLINE=51, EMBASE=408, CENTRAL=13) and 1 registry (Clinicaltrials.gov=7). 460 records were excluded based on title and abstract (including duplicates). 19 full text reports were assessed for eligibility and included in review (basic science/animal study paper 2, Clinicaltrials.gov randomised controlled trial submission 1 (currently recruiting), basic science/animal study conference abstract 5, case report 2, review 3, editorial comment 2, clinical guidelines 1, retrospective/registry-based conference abstract 3).

CONCLUSION

Cardiotoxicity is the most common dose-limiting toxicity associated with trastuzumab. Discontinuation of trastuzumab however, can lead to worse cancer outcomes. There have been case reports, registry-based, retrospective cohort-based and mechanistic studies suggesting the cardioprotective potential of SGLT2i in cancer therapy-related cardiac dysfunction (CTRCD). Based on these, there is now a call for randomised controlled trials to be performed in this patient cohort to advise guideline-directed therapy for CTRCD, which will in turn also provide detailed safety information and improve cancer and cardiovascular outcomes.

ZNF746 plays cardinal roles on colorectal cancer (CRC) cell invasion and migration and regulates mitochondrial dynamics and morphological changes of CRC cells-Role of combined melatonin and 5-FU regimen

The underlying mechanism of colorectal cells developing into cancer cells has been extensively investigated, yet is still not fully delineated, resulting in the treatment of advanced colorectal cancer (CRC) remains regrettably an unmet need. Zinc Finger Protein 746/Parkin-interacting substrate (ZNF746/PARIS) has previously been identified to play a fundamental role on bladder cancer cell proliferation and metastasis that were effectively inhibited by melatonin (Mel). In this study, we utilized ex vivo/in vivo studies to verify whether the ZNF746 signaling was also crucial in CRC growth/invasion/migration. Tissue-bank specimens showed that the protein expression of ZNF746 was significantly increased in CRC than that of healthy colorectal tissues (p < 0.001). Additionally, in vitro study demonstrated that excessive expression of ZNF746 significantly inhibited mitochondrial activity via (1) interfering with the dynamic balance of mitochondrial fusion/fission and (2) inhibiting the protein expression of MFN1/MFN2/PGC1a (all p < 0.001). Furthermore, we identified that inhibition of ZNF746 protein expression significantly reduced the resistance of CRC cell lines to the anticancer drug of 5-FU (p < 0.001), whereas overexpression of ZNF746 significantly augmented resistance of CRC cells to 5-FU (all p < 0.001). Finally, using the cell culture method, we found that combined Mel and 5-FU was superior to merely one on promoting the CRC cell apoptosis (p < 0.001). Our results confirmed that ZNF746 signaling played a cardinal role of CRC cell proliferation/survival and combined Mel and 5-FU treatment attenuated the resistance of CRC cells to the drug mainly through suppressing this signaling.

Cytosine-phosphate-guanine oligodeoxynucleotides alleviate radiation-induced kidney injury in cervical cancer by inhibiting DNA damage and oxidative stress through blockade of PARP1/XRCC1 axis

BACKGROUND

Radiotherapy can cause kidney injury in patients with cervical cancer. This study aims to investigate the possible molecular mechanisms by which CpG-ODNs (Cytosine phosphate guanine-oligodeoxynucleotides) regulate the PARP1 (poly (ADP-ribose) polymerase 1)/XRCC1 (X-ray repair cross-complementing 1) signaling axis and its impact on radiation kidney injury (RKI) in cervical cancer radiotherapy.

METHODS

The GSE90627 dataset related to cervical cancer RKI was obtained from the Gene Expression Omnibus (GEO) database. Bioinformatics databases and R software packages were used to analyze the target genes regulated by CpG-ODNs. A mouse model of RKI was established by subjecting C57BL/6JNifdc mice to X-ray irradiation. Serum blood urea nitrogen (BUN) and creatinine levels were measured using an automated biochemical analyzer. Renal tissue morphology was observed through HE staining, while TUNEL staining was performed to detect apoptosis in renal tubular cells. ELISA was conducted to measure levels of oxidative stress-related factors in mouse serum and cell supernatant. An in vitro cell model of RKI was established using X-ray irradiation on HK-2 cells for mechanism validation. RT-qPCR was performed to determine the relative expression of PARP1 mRNA. Cell proliferation activity was assessed using the CCK-8 assay, and Caspase 3 activity was measured in HK-2 cells. Immunofluorescence was used to determine γH2AX expression.

RESULTS

Bioinformatics analysis revealed that the downstream targets regulated by CpG-ODNs in cervical cancer RKI were primarily PARP1 and XRCC1. CpG-ODNs may alleviate RKI by inhibiting DNA damage and oxidative stress levels. This resulted in significantly decreased levels of BUN and creatinine in RKI mice, as well as reduced renal tubular and glomerular damage, lower apoptosis rate, decreased DNA damage index (8-OHdG), and increased levels of antioxidant factors associated with oxidative stress (SOD, CAT, GSH, GPx). Among the CpG-ODNs, CpG-ODN2006 had a more pronounced effect. CpG-ODNs mediated the inhibition of PARP1, thereby suppressing DNA damage and oxidative stress response in vitro in HK-2 cells. Additionally, PARP1 promoted the formation of the PARP1 and XRCC1 complex by recruiting XRCC1, which in turn facilitated DNA damage and oxidative stress response in renal tubular cells. Overexpression of either PARP1 or XRCC1 reversed the inhibitory effects of CpG-ODN2006 on DNA damage and oxidative stress in the HK-2 cell model and RKI mouse model.

CONCLUSION

CpG-ODNs may mitigate cervical cancer RKI by blocking the activation of the PARP1/XRCC1 signaling axis, inhibiting DNA damage and oxidative stress response in renal tubule epithelial cells.

Cardioprotective Effects of Sodium Glucose Cotransporter 2 Inhibition in Angiotensin II-Dependent Hypertension Are Mediated by the Local Reduction of Sympathetic Activity and Inflammation

The cardioprotective effects of sodium glucose cotrasponter 2 (SGLT2) inhibitors seem to be independent from the effects on glycemic control, through little-known mechanisms. In this study, we investigate whether the cardioprotective effects of empagliflozin, a SGLT2 inhibitor, may be associated with myocardial sympathetic activity and inflammatory cell infiltration in an experimental model of angiotensin II-dependent hypertension. Angiotensin II (Ang II), Ang II plus Empagliflozin, physiological saline, or physiological saline plus empagliflozin were administered to Sprague Dawley rats for two weeks. Blood pressure was measured by plethysmographic method. Myocardial hypertrophy and fibrosis were analysed by histomorphometry, and inflammatory cell infiltration and tyrosine hydroxylase expression, implemented as a marker of sympathetic activity, were evaluated by immunohistochemistry. Ang II increased blood pressure, myocardial hypertrophy, fibrosis, inflammatory infiltrates and tyrosine hydroxylase expression, as compared to the control group. Empagliflozin administration prevented the development of myocardial hypertrophy, fibrosis, inflammatory infiltrates and tyrosine hydroxylase overexpression in Ang II-treated rats, without affecting blood glucose and the Ang II-dependent increase in blood pressure. These data demonstrate that the cardioprotective effects of SGLT2 inhibition in Ang II-dependent hypertension may result from the myocardial reduction of sympathetic activity and inflammation and are independent of the modulation of blood pressure and blood glucose levels.

Platelet Rich Plasma and Adipose-Derived Mesenchymal Stem Cells Mitigate Methotrexate-Induced Nephrotoxicity in Rat via Nrf2/Pparγ/HO-1 and NF-Κb/Keap1/Caspase-3 Signaling Pathways: Oxidative Stress and Apoptosis Interplay

BACKGROUND

the nephrotoxicity of methotrexate (MTX) is observed in high-dose therapy. Moreover, low-dose MTX therapy for rheumatic diseases is debatable and claimed to cause renal impairment. This study aimed at studying the effect of methotrexate in repeated low doses on rat kidneys and assessing the efficacy of adipose-derived mesenchymal stem cells (AD-MSCs) and platelet rich plasma (PRP) for attenuating this effect.

METHODS

Forty-two male Wistar rats were used, 10 rats were donors of AD-MSCs and PRP, 8 rats served as control, and the remaining rats were subjected to induction of nephrotoxicity by MTX intraperitoneal injection once weekly for successive 8 weeks and then assigned into 3 groups of 8 animals each: Group II: received MTX only. Group III: received MTX + PRP. Group IV: received MTX + AD-MSCs. After one month, rats were anaesthetized, serum-sampled, and renal tissue removed for biochemical, histological, and ultrastructural evaluation.

RESULTS

there was significant tubular degeneration, glomerulosclerosis, fibrosis, decreased renal index, along with increased levels of urea and creatinine in the MTX group compared to the control group. Immunohistochemical expression of caspase-3 and iNOS in the renal tissue was significantly increased in group II compared to groups III and IV. Biochemical results revealed higher tissue malondialdehyde (MDA) concentration in the MTX-injected group which decreased significantly in co-treatment with either AD-MSC or PRP + MTX. MSC promoted the activation of the Nrf2/PPARγ/HO-1 and NF-κB/Keap1/caspase-3 pathways, increased antioxidant enzyme activities, reduced lipid peroxidation levels, and alleviated oxidative damage and apoptosis. PRP showed therapeutic effects and molecular mechanisms similar to MSC. Furthermore, MSC and PRP treatment significantly reduced MTX-induced upregulation of the pro-inflammatory (NF-κB, interleukin-1ß, and TNF-α), oxidative stress (Nrf-2, hemoxygenase-1, glutathione, and malondialdehyde), and nitrosative stress (iNOS) markers in the kidney.

CONCLUSION

repeated administration of low-dose MTX resulted in massive renal tissue toxicity and deterioration of renal function in rats which proved to be attenuated by PRP and AD-MSCs through their anti-inflammatory, anti-apoptotic and anti-fibrotic properties.

Insights into SGLT2 inhibitor treatment of diabetic cardiomyopathy: focus on the mechanisms

Among the complications of diabetes, cardiovascular events and cardiac insufficiency are considered two of the most important causes of death. Experimental and clinical evidence supports the effectiveness of SGLT2i for improving cardiac dysfunction. SGLT2i treatment benefits metabolism, microcirculation, mitochondrial function, fibrosis, oxidative stress, endoplasmic reticulum stress, programmed cell death, autophagy, and the intestinal flora, which are involved in diabetic cardiomyopathy. This review summarizes the current knowledge of the mechanisms of SGLT2i for the treatment of diabetic cardiomyopathy.

Sodium-glucose Cotransporter 2 Inhibitors and Pathological Myocardial Hypertrophy

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new type of oral hypoglycemic drugs that exert a hypoglycemic effect by blocking the reabsorption of glucose in the proximal renal tubules, thus promoting the excretion of glucose from urine. Their hypoglycemic effect is not dependent on insulin. Increasing data shows that SGLT2 inhibitors improve cardiovascular outcomes in patients with type 2 diabetes. Previous studies have demonstrated that SGLT2 inhibitors can reduce pathological myocardial hypertrophy with or without diabetes, but the exact mechanism remains to be elucidated. To clarify the relationship between SGLT2 inhibitors and pathological myocardial hypertrophy, with a view to providing a reference for the future treatment thereof, this study reviewed the possible mechanisms of SGLT2 inhibitors in attenuating pathological myocardial hypertrophy. We focused specifically on the mechanisms in terms of inflammation, oxidative stress, myocardial fibrosis, mitochondrial function, epicardial lipids, endothelial function, insulin resistance, cardiac hydrogen and sodium exchange, and autophagy.

18F-FDG PET/MRI Imaging in a Preclinical Rat Model of Cardiorenal Syndrome-An Exploratory Study

Cardiorenal syndrome (CRS) denotes the bidirectional interaction of chronic kidney disease and heart failure with an adverse prognosis but with a limited understanding of its pathogenesis. This study correlates biochemical blood markers, histopathological and immunohistochemistry features, and 2-deoxy-2-fluoro-D-glucose positron emission tomography (¹⁸F-FDG PET) metabolic data in low-dose doxorubicin-induced heart failure, cardiorenal syndrome, and renocardiac syndrome induced on Wistar male rats. To our knowledge, this is the first study that investigates the underlying mechanisms for CRS progression in rats using ¹⁸F-FDG PET. Clinical, metabolic cage monitoring, biochemistry, histopathology, and immunohistochemistry combined with PET/MRI (magnetic resonance imaging) data acquisition at distinct points in the disease progression were employed for this study in order to elucidate the available evidence of organ crosstalk between the heart and kidneys. In our CRS model, we found that chronic treatment with low-dose doxorubicin followed by acute 5/6 nephrectomy incurred the highest mortality among the study groups, while the model for renocardiac syndrome resulted in moderate-to-high mortality. ¹⁸F-FDG PET imaging evidenced the doxorubicin cardiotoxicity with vascular alterations, normal kidney development damage, and impaired function. Given the fact that standard clinical markers were insensitive to early renal injury, we believe that the decreasing values of the ¹⁸F-FDG PET-derived renal marker across the groups and, compared with their age-matched controls, along with the uniform distribution seen in healthy developing rats, could have a potential diagnostic and prognostic yield in cardiorenal syndrome.

Beneficial Effects of Empagliflozin Are Mediated by Reduced Renal Inflammation and Oxidative Stress in Spontaneously Hypertensive Rats Expressing Human C-Reactive Protein

Gliflozins (inhibitors of sodium-glucose cotransporter 2) show many beneficial actions beyond their antidiabetic effects. The underlying mechanisms of these additional protective effects are still not well understood, especially under non-diabetic conditions. Therefore, we analyzed the effects of empagliflozin in young (3-month-old) and adult (12-month-old) male spontaneously hypertensive rats (SHR) expressing human C-reactive protein (CRP) in the liver. SHR-CRP rats are a non-diabetic model of metabolic syndrome, inflammation, and organ damage. Empagliflozin was given in a daily dose of 10 mg/kg body weight for 8 weeks. Both age groups of SHR-CRP rats treated with empagliflozin had lower body weight, decreased weight of fat depots, reduced ectopic fat accumulation in the liver and kidneys, and decreased levels of plasma insulin and β-hydroxybutyrate. Empagliflozin effectively reduced ectopic renal fat accumulation, and was associated with decreased inflammation. Exclusively in young rats, decreased microalbuminuria after empagliflozin treatment was accompanied by attenuated oxidative stress. In adult animals, empagliflozin also improved left ventricle function. In conclusion, in young animals, the beneficial renoprotective effects of empagliflozin could be ascribed to reduced lipid deposition in the kidney and the attenuation of oxidative stress and inflammation. In contrast, hepatic lipid metabolism was ameliorated in adult rats.

Suppression of Cardiogenic Edema with Sodium–Glucose Cotransporter-2 Inhibitors in Heart Failure with Reduced Ejection Fraction: Mechanisms and Insights from Pre-Clinical Studies

In heart failure with reduced ejection fraction (HFrEF), cardiogenic edema develops from impaired cardiac function, pathological remodeling, chronic inflammation, endothelial dysfunction, neurohormonal activation, and altered nitric oxide-related pathways. Pre-clinical HFrEF studies have shown that treatment with sodium–glucose cotransporter-2 inhibitors (SGLT-2i) stimulates natriuretic and osmotic/diuretic effects, improves overall cardiac function, attenuates maladaptive cardiac remodeling, and reduces chronic inflammation, oxidative stress, and endothelial dysfunction. Here, we review the mechanisms and effects of SGLT-2i therapy on cardiogenic edema in various models of HFrEF. Overall, the data presented suggest a high translational importance of these studies, and pre-clinical studies show that SGLT-2i therapy has a marked effect on suppressing the progression of HFrEF through multiple mechanisms, including those that affect the development of cardiogenic edema.

Could SGLT2 Inhibitors Improve Exercise Intolerance in Chronic Heart Failure?

Despite the constant improvement of therapeutical options, heart failure (HF) remains associated with high mortality and morbidity. While new developments in guideline-recommended therapies can prolong survival and postpone HF hospitalizations, impaired exercise capacity remains one of the most debilitating symptoms of HF. Exercise intolerance in HF is multifactorial in origin, as the underlying cardiovascular pathology and reactive changes in skeletal muscle composition and metabolism both contribute. Recently, sodium-related glucose transporter 2 (SGLT2) inhibitors were found to improve cardiovascular outcomes significantly. Whilst much effort has been devoted to untangling the mechanisms responsible for these cardiovascular benefits of SGLT2 inhibitors, little is known about the effect of SGLT2 inhibitors on exercise performance in HF. This review provides an overview of the pathophysiological mechanisms that are responsible for exercise intolerance in HF, elaborates on the potential SGLT2-inhibitor-mediated effects on these phenomena, and provides an up-to-date overview of existing studies on the effect of SGLT2 inhibitors on clinical outcome parameters that are relevant to the assessment of exercise capacity. Finally, current gaps in the evidence and potential future perspectives on the effects of SGLT2 inhibitors on exercise intolerance in chronic HF are discussed.

Protective effect of empagliflozin on gentamicin-induced acute renal injury via regulation of SIRT1/NF-κB signaling pathway

Gentamicin is a highly effective antibiotic. However, its major complication is nephrotoxicity. This study investigated the beneficial effects of empagliflozin against gentamicin-induced nephropathy. Kidney damage was induced in male Wistar rats by administration of gentamicin (100 mg/kg/day, i.p.) for 8 days. Two doses of empagliflozin (10 and 20 mg/kg, p.o.) were concomitantly given with gentamicin for 8 days. Gentamicin administration increased serum creatinine, urea, and cystatin C concentrations. Empagliflozin in both doses ameliorated these changes via mitigation of gentamicin-induced increase in renal oxidative stress, inflammation, and apoptosis. Empagliflozin added to GM treatment led to lower measured levels of TGF-B, NF-κB and caspase 3, and only the higher dose increased PAX2 levels indicating an improvement in tubular regeneration. Additionally, empagliflozin (20 mg/kg/day) markedly prevented gentamicin-induced histopathological changes. The protective effects of empagliflozin may be mediated by decreasing gentamicin concentration in renal tissue and possibly other effects like antioxidant and antiapoptotic effects.

Combined therapy with dapagliflozin and entresto offers an additional benefit on improving the heart function in rat after ischemia-reperfusion injury

BACKGROUND

This study tested whether combined dapagliflozin and entresto treatment would be superior to either one alone for preserving the left-ventricular ejection-fraction (LVEF) in rat after ischemia-reperfusion (IR) injury.

METHODS AND RESULTS

In vitro flow-cytometric result showed that the intracellular and mitochondrial reactive oxygen species and mitochondrial permeability transition pore, and protein levels of oxidative-stress/DNA-damaged markers [NADPH-oxidase-1 (NOX-1)/NOX-2/oxidized-protein/γ-H2A-histone-family member X (γ-H2AX)] were significantly higher in hydrogen peroxide (H₂O₂) (300μM)-treated H9C2 cells as compared with the controls that were significantly reversed in sacubitril/valsartan and dapagliflozin therapy in the same H₂O₂-treated condition, whereas the protein expressions of antioxidants [Sirtuin-1 (SIRT1)/SIRT3/superoxide dismutase/catalase/glutathione peroxidase) exhibited an opposite pattern among the groups (all p<0.001). Adult-male-Sprague-Dawley rat (n=40) were equally categorized into group 1 (sham-operated control), group 2 (IR), group 3 (IR+dapagliflozin/20mg/kg/orally at 3h and post-days 1/2/3 after IR), group 4 (IR+entresto/100mg/kg/orally at 3h and post-days 1/2/3 after IR) and group 5 (IR+dapagliflozin+entresto) and the hearts were harvested by day 3 after IR. The 3^rd day's LVEF was highest in group 1, lowest in group 2 and significantly higher in group 5 than in groups 3/4, but it was similar between the latter two groups (p<0.001). The protein expressions of oxidative-stress (NOX-1/NOX-2/oxidized protein), fibrotic (transforming-growth factor-ß/phosphorylated-Smad3), apoptotic [mitochondrial-Bax/cleaved-caspase-3/cleaved-poly (ADP-ribose) polymerase], mitochondria/DNA damaged (cytosolic-cytochrome-C/γ-H2AX), pressure-overload/heart-failure [brain natriuretic peptide (BNP)/ß-myosin heavy chain] and autophagic (ratio of meiotic cyclins CLB3-II/CLB3-I) biomarkers, and the upstream (high-mobility group box 1/Toll-like receptor-4/MyD88/phosphorylated-nuclear factor-κB and downstream [interleukin (IL)-1ß/IL-6/tumor necrosis factor-α] inflammatory signalings revealed an antithetical features of LVEF among the groups (all p<0.0001). The cellular levels of inflammatory (myeloperoxidase+/CD68+), pressure-overload/heart-failure (BNP+) and DNA-damage (γ-H2AX+) biomarkers as well as infarct area demonstrated an opposite pattern of LVEF among the groups (all p<0.0001).

CONCLUSION

Incorporated entresto-dapagliflozin treatment was superior to either one alone on protecting the heart against IR injury.

Mitochondrial Dysfunction: An Emerging Link in the Pathophysiology of Cardiorenal Syndrome

The crosstalk between the heart and kidney is carried out through various bidirectional pathways. Cardiorenal syndrome (CRS) is a pathological condition in which acute or chronic dysfunction in the heart or kidneys induces acute or chronic dysfunction of the other organ. Complex hemodynamic factors and biochemical and hormonal pathways contribute to the development of CRS. In addition to playing a critical role in generating metabolic energy in eukaryotic cells and serving as signaling hubs during several vital processes, mitochondria rapidly sense and respond to a wide range of stress stimuli in the external environment. Impaired adaptive responses ultimately lead to mitochondrial dysfunction, inducing cell death and tissue damage. Subsequently, these changes result in organ failure and trigger a vicious cycle. In vitro and animal studies have identified an important role of mitochondrial dysfunction in heart failure (HF) and chronic kidney disease (CKD). Maintaining mitochondrial homeostasis may be a promising therapeutic strategy to interrupt the vicious cycle between HF and acute kidney injury (AKI)/CKD. In this review, we hypothesize that mitochondrial dysfunction may also play a central role in the development and progression of CRS. We first focus on the role of mitochondrial dysfunction in the pathophysiology of HF and AKI/CKD, then discuss the current research evidence supporting that mitochondrial dysfunction is involved in various types of CRS.

Empagliflozin Alleviates Left Ventricle Hypertrophy in High-Fat-Fed Mice by Modulating Renin Angiotensin Pathway

Aims. The cardiobenefits of empagliflozin are multidimensional, and some mechanisms are still unclear. The aim of the present study was to evaluate the effect of treatment with empagliflozin on biometric parameters and gene expression in the local cardiac RAS, oxidative stress, and endoplasmic reticulum pathways in a mouse model. Main Methods. Forty male C57BL/6 mice were fed with control (C) or high-fat (HF) diets for 10 weeks. After that, the groups were redistributed according to the treatment with empagliflozin—CE or HFE. The empagliflozin was administered via food for 5 weeks (10 mg/kg/day). We performed biochemical analyses, blood pressure monitoring, oral glucose tolerance test, left ventricle (LV) stereology, RT-qPCR for genes related to classical and counterregulatory local RAS, oxidative stress, and endoplasmic reticulum stress. Key Findings. In comparison to HF, HFE decreased body mass and improved glucose intolerance and insulin resistance. The cardiac parameters were enhanced after treatment as expressed by decrease in plasma cholesterol, plasma uric acid, and systolic blood pressure. In addition, LV analysis showed that empagliflozin reduces cardiomyocyte area and LV thickness. The local RAS had less activity of the classical pathway and positive effects on the counterregulatory pathway. Empagliflozin treatment also decreased oxidative stress and endoplasmic reticulum stress-related genes. Significance. Our results suggests that empagliflozin modulates the local RAS pathway towards alleviation of oxidative stress and ER stress in the LV, which may be a route to its effects on improved cardiac remodeling.

Antihypertensive and metabolic effects of empagliflozin in Ren-2 transgenic rats, an experimental non-diabetic model of hypertension

The new antidiabetic drugs, gliflozins, inhibit sodium-glucose transporter-2 in renal proximal tubules promoting glucose and sodium excretion. This leads not only to a significant improvement of glucose control but also to the reduction of blood pressure and body weight in both diabetic patients and experimental models. We examined whether these beneficial effects can also be achieved in a non-diabetic hypertensive model, namely in Ren-2 transgenic rats (TGR). Adult 6-month-old hypertensive TGR and their normotensive controls (Hannover Sprague-Dawley rats), were either untreated or treated with empagliflozin (10 mg/kg/day) for two months. Telemetric blood pressure monitoring, renal parameters as well as cardiac function via echocardiography were analyzed during the experiment. At the end of the study, the contribution of major vasoactive systems to blood pressure maintenance was studied. Metabolic parameters and markers of oxidative stress and inflammation were also analyzed. Empagliflozin had no effect on plasma glucose level but partially reduced blood pressure in TGR. Although food consumption was substantially higher in empagliflozin-treated TGR compared to the untreated animals, their body weight and the amount of epididymal and perirenal fat was decreased. Empagliflozin had no effect on proteinuria, but it decreased plasma urea, attenuated renal oxidative stress and temporarily increased urinary urea excretion. Several metabolic (hepatic triglycerides, non-esterified fatty acids, insulin) and inflammatory (TNF-α, leptin) parameters were also improved by empagliflozin treatment. By contrast, echocardiography did not reveal any effect of empagliflozin on cardiac function. In conclusion, empagliflozin exerted beneficial antihypertensive, anti-inflammatory and metabolic effects also in a non-diabetic hypertensive model.

Entresto protected the cardiomyocytes and preserved heart function in cardiorenal syndrome rat fed with high-protein diet through regulating the oxidative stress and Mfn2-mediated mitochondrial functional integrity

This study tested the hypothesis that Entresto (En) therapy protected the cardiomyocytes and heart function in cardiorenal syndrome (CRS) rats fed with high-protein diet (HPD) through regulating the oxidative-stress and Mfn2-mediated mitochondrial functional integrity. En (12.5 μM for the in-vitro study) protected the H9C2-cells against H₂O₂-induced cell apoptosis, whereas stepwise-increased H₂O₂ concentrations induced a significant increase in protein expressions of Mfn2/phosphorylated (p)-DRP1/mitochondrial-Bax in H9C2-cells. En downregulated H₂O₂-induced mitochondrial fission/upregulated mitochondrial fusion and deletion of Mfn2 gene (i.e., shMfn2) to significantly reduce H₂O₂-induced ROS production. En significantly suppressed and shMfn2 further significantly suppressed both H₂O₂-reduced mitochondrial-membrane potential and H₂O₂-induced ROS production/cell apoptosis/mitochondrial damage/mitochondrial-Bax released from mitochondria in H9C2 cells. En significantly reduced protein expressions of Mfn2 and p-DRP1. Additionally, En significantly suppressed and shMfn2 further significantly suppressed the protein expressions of mitochondrial-damaged (DRP1)/oxidative-stress (NOX-1/NOX-2)/apoptosis (mitochondrial-Bax/caspase-3/PARP)/autophagic (LC3B-II/LC3B-I) biomarkers (all p < 0.01). Rats were categorized into group 1 [sham-control + high-protein-diet (HPD)], group 2 (CRS + HPD) and group 3 (CRS+ HPD + En/100 mg/kg/day). By day 63 after CRS induction, the LVEF was significantly lower in group 3 and more significantly lower in group 2 than in group 1, whereas the protein expressions of oxidative-stress (NOX-1/NOX-2/p22phox/oxidized protein)/apoptotic (mitochondrial-Bax/caspase-3/PARP), fibrotic (Smad-3/TGF-ß), autophagic (Beclin-1/Atg5/ratio of LC3B-II/LC3B-I) and mitochondrial-damaged (DRP1/cyclophilin-D/cytosolic-cytochrome-C) biomarkers exhibited an opposite pattern of LVEF among the groups. Downregulation of Mfn2 by En or shMfn2 in cardiomyocytes avoided H₂O₂ damage and En improved the cardiac function in HPD-feeding CRS rat via adjusting Mfn2-mediated mitochondrial functional integrity.

Early treatment with combination of SS31 and entresto effectively preserved the heart function in doxorubicin-induced dilated cardiomyopathic rat

BACKGROUND

This study tested the hypothesis that early administration of SS31 and entresto (En) was superior to either one alone on preserving the heart function in setting of dilated cardiomyopathy (DCM) induced by doxorubicin (Dox) [accumulated dosage of 12.5 mg/kg/administered by intraperitoneal (IP) at 4 separated time points within 20 days] in rat.

METHODS AND RESULTS

Adult-male SD rats (n = 40) were equally categorized into groups 1 (sham-control), 2 (DCM), 3 (DCM + SS31/0.7 mg/kg/day/IP, since day-14 after DCM induction to day-60), 4 [DCM + En (30 mg/kg/day/orally since day-14 after DCM induction to day-60)] and 5 (DCM + combined SS31-En), and animals were euthanized by day 60. By day 60, left-ventricular ejection-fraction (LVEF) was highest in group 1, lowest in group 2 and significantly higher in group 5 than in groups 3 and 4 (all p < 0.0001), but it showed no difference between groups 3/4. The microscopic study showed that the fibrosis area/cardiomyocyte size and DNA-damaged (γ-H2AX+)/inflammatory (CD14+//CD68+) markers, and flow analysis of inflammatory (Ly6G+/MPO+/CD11^b/c+) and early/late apoptosis (AN-V⁺/PI^-//AN-V⁺/PI⁺) cells exhibited an opposite pattern of LVEF among the five groups (all p < 0.0001). The protein expressions of inflammatory upstream (TLR2/TLR4/MyD88/Mal/ TRAF6/IKK-α/IKK-ß) and downstream (p-NF-κb/TNF-α/IL-1ß/MMP-9), oxidative-stress/mitochondrial-damaged (NOX-1/NOX-2/cytosolic cytochrome-C/cyclophilin-D/DRP1) and autophagic/apoptotic (ratio of LC3B-II/LC3B-I and mitochondrial-Bax/caspase3/9) signaling pathways also exhibited an opposite pattern of LVEF among the five groups (all p < 0.0001).

CONCLUSION

Combined SS31-En therapy was superior to either one alone on protecting the heart structural and functional integrities against Dox-induced DCM damage.

Xenogeneic and Allogeneic Mesenchymal Stem Cells Effectively Protect the Lung Against Ischemia-reperfusion Injury Through Downregulating the Inflammatory, Oxidative Stress, and Autophagic Signaling Pathways in Rat

This study tested the hypothesis that both allogenic adipose-derived mesenchymal stem cells (ADMSCs) and human inducible pluripotent stem cell-derived MSCs (iPS-MSCs) offered a comparable effect for protecting the lung against ischemia-reperfusion (IR) injury in rodent through downregulating the inflammatory, oxidative stress, and autophagic signaling pathways. Adult male Sprague–Dawley rats (n = 32) were categorized into group 1 (sham-operated control), group 2 (IRI), group 3 [IRI + ADMSCs (1.0 × 10⁶ cells)/tail-vein administration at 0.5/18/36 h after IR], and group 4 [IRI + iPS-MSCs (1.0 × 10⁶ cells)/tail-vein administration at 0.5/18/36 h after IR], and lungs were harvested at 72 h after IR procedure. In vitro study demonstrated that protein expressions of three signaling pathways in inflammation (TLR4/MyD88/TAK1/IKK/I-κB/NF-κB/Cox-2/TNF-α/IL-1ß), mitochondrial damage/cell apoptosis (cytochrome C/cyclophilin D/DRP1/ASK1/APAF-1/mitochondrial-Bax/caspase3/8/9), and autophagy/cell death (ULK1/beclin-1/Atg5,7,12, ratio of LCB3-II/LC3B-I, p-AKT/m-TOR) were significantly higher in lung epithelial cells + 6h hypoxia as compared with the control, and those were significantly reversed by iPS-MSC treatment (all P < 0.001). Flow cytometric analysis revealed that percentages of the inflammatory cells in bronchioalveolar lavage fluid and circulation, and immune cells in circulation/spleen as well as circulatory early and late apoptotic cells were highest in group 2, lowest in group 1, and significantly higher in group 3 than in group 4 (all P < 0.0001). Microscopy showed the lung injury score and numbers of inflammatory cells and Western blot analysis showed the signaling pathways of inflammation, mitochondrial damage/cell apoptosis, autophagy, and oxidative stress exhibited an identical pattern of flow cytometric results among the four groups (all P < 0.0001). Both xenogeneic and allogenic MSCs protected the lung against IRI via suppressing the inflammatory, oxidative stress, and autophagic signaling.

The SGLT-2 inhibitor empagliflozin improves myocardial strain, reduces cardiac fibrosis and pro-inflammatory cytokines in non-diabetic mice treated with doxorubicin

BACKGROUND

Empagliflozin (EMPA), a selective inhibitor of the sodium glucose co-transporter 2, reduced the risk of hospitalization for heart failure and cardiovascular death in type 2 diabetic patients in the EMPA-REG OUTCOME trial. Recent trials evidenced several cardio-renal benefits of EMPA in non-diabetic patients through the involvement of biochemical pathways that are still to be deeply analysed. We aimed to evaluate the effects of EMPA on myocardial strain of non-diabetic mice treated with doxorubicin (DOXO) through the analysis of NLRP3 inflammasome and MyD88-related pathways resulting in anti-apoptotic and anti-fibrotic effects.

METHODS

Preliminary cellular studies were performed on mouse cardiomyocytes (HL-1 cell line) exposed to doxorubicin alone or combined to EMPA. The following analysis were performed: determination of cell viability (through a modified MTT assay), study of intracellular ROS production, lipid peroxidation (quantifying intracellular malondialdehyde and 4-hydroxynonenal), intracellular Ca2+ homeostasis. Moreover, pro-inflammatory studies were also performed: expression of NLRP3 inflammasome, MyD88 myddosome and p65/NF-κB associated to secretion of cytokines involved in cardiotoxicity (Interleukins 1β, 8, 6). C57Bl/6 mice were untreated (Sham, n = 6) or treated for 10 days with doxorubicin (DOXO, n = 6), EMPA (EMPA, n = 6) or doxorubicin combined to EMPA (DOXO-EMPA, n = 6). DOXO was injected intraperitoneally. Ferroptosis and xanthine oxidase were studied before and after treatments. Cardiac function studies, including EF, FS and radial/longitudinal strain were analysed through transthoracic echocardiography (Vevo 2100). Cardiac fibrosis and apoptosis were histologically studied through Picrosirius red and TUNEL assay, respectively and quantified through pro-collagen-1α1, MMP-9 and Caspase-3 expression. Tissue NLRP3, MyD88 and cytokines were also quantified before and after treatments through ELISA methods.

RESULTS

Cardiomyocytes exposed to doxorubicin increased the intracellular Ca2+ content and expression of several pro-inflammatory markers associated to cell death; co-incubation with EMPA reduced significantly the magnitude of the effects. In preclinical study, EMPA increased EF and FS compared to DOXO groups (p < 0.05), prevented the reduction of radial and longitudinal strain after 10 days of treatment with doxorubicin (RS) 30.3% in EMPA-DOXO vs 15.7% in DOXO mice; LS - 17% in EMPA-DOXO vs - 11.7% in DOXO mice (p < 0.001 for both). Significant reductions in ferroptosis, xanthine oxidase expression, cardiac fibrosis and apoptosis in EMPA associated to DOXO were also seen. A reduced expression of pro-inflammatory cytokines, NLRP3, MyD88 and NF-kB in heart, liver and kidneys was also seen in DOXO-EMPA group compared to DOXO (p < 0.001).

CONCLUSION

EMPA reduced ferroptosis, fibrosis, apoptosis and inflammation in doxorubicin-treated mice through the involvement of NLRP3 and MyD88-related pathways, resulting in significant improvements in cardiac functions. These findings provides the proof of concept for translational studies designed to reduce adverse cardiovascular outcomes in non-diabetic cancer patients treated with doxorubicin.

Empagliflozin and neohesperidin protect against methotrexate-induced renal toxicity via suppression of oxidative stress and inflammation in male rats

Kidney injury from chemotherapy is one of the worsening problems associated with methotrexate (MTX) use. This work aims to examine the nephroprotective effects of empagliflozin (EMPA) and neohesperidin dihydrochalcone (NHD) provoked by MTX. A rat model was implemented by a single administration of MTX (20 mg/kg, i.p.). EMPA and NHD were administered in two doses (10 and 30 mg/kg, p.o.) and (40 and 80 mg/kg, p.o.), respectively for 14 consecutive days, using N-acetylcysteine (150 mg/kg, p.o.) as a reference standard. Pretreatment with EMPA and NHD showed significant attenuation in the renal function biomarkers, histopathological abrasions, and renal oxidative parameters. Also, EMPA and NHD pretreatment produced marked reductions in the expression of IL-6 and TNF-α level as proinflammatory biomarkers. Furthermore, EMPA and NHD pretreatment revealed marked decreases in the expression level of NF-ĸB, Keap1, HSP70, and caspase-3 and notable increases in Nrf2, PPARγ and HO-1 expression levels. EMPA and NHD can constrain oxidative stress liberation, inflammatory mediators proliferation, and apoptotic reactions in the renal tissue, which may be promising for further clinical applications to protect against MTX-induced renal injury or at least to reduce its adverse effects.

Double overexpression of miR-19a and miR-20a in induced pluripotent stem cell-derived mesenchymal stem cells effectively preserves the left ventricular function in dilated cardiomyopathic rat

BACKGROUND

This study tested the hypothesis that double overexpression of miR-19a and miR-20a (dOex-mIRs) in human induced pluripotent stem cell (iPS)-derived mesenchymal stem cells (MSCs) effectively preserved left ventricular ejection fraction (LVEF) in dilated cardiomyopathy (DCM) (i.e., induced by doxorubicin) rat.

METHODS AND RESULTS

In vitro study was categorized into groups G1 (iPS-MSC), G2 (iPS-MSC^dOex-mIRs), G3 (iPS-MSC + H₂O₂/100uM), and G4 (iPS-MSC^dOex-mIRs + H₂O₂/100uM). The in vitro results showed the cell viability was significantly lower in G3 than in G1 and G2, and that was reversed in G4 but it showed no difference between G1/G2 at time points of 6 h/24 h/48 h, whereas the flow cytometry of intra-cellular/mitochondrial oxidative stress (DCFA/mitoSOX) and protein expressions of mitochondrial-damaged (cytosolic-cytochrome-C/DRP1/Cyclophilin-D), oxidative-stress (NOX-1/NOX2), apoptotic (cleaved-caspase-3/PARP), fibrotic (p-Smad3/TGF-ß), and autophagic (ratio of LC3B-II/LC3BI) biomarkers exhibited an opposite pattern of cell-proliferation rate (all p< 0.001). Adult-male SD rats (n=32) were equally divided into groups 1 (sham-operated control), 2 (DCM), 3 (DCM + iPS-MSCs/1.2 × 10⁶ cells/administered by post-28 day's DCM induction), and 4 (DCM + iPS-MSC^dOex-mIRs/1.2 × 10⁶ cells/administered by post-28 day's DCM induction) and euthanized by day 60 after DCM induction. LV myocardium protein expressions of oxidative-stress signaling (p22-phox/NOX-1/NOX-2/ASK1/p-MMK4,7/p-JNK1,2/p-cJUN), upstream (TLR-4/MAL/MyD88/TRIF/TRAM/ TFRA6/IKK_α/ß/NF-κB) and downstream (TNF-α/IL-1ß/MMP-9) inflammatory signalings, apoptotic (cleaved-PARP/mitochondrial-Bax), fibrotic (Smad3/TGF-ß), mitochondrial-damaged (cytosolic-cytochrome-C/DRP1/cyclophilin-D), and autophagic (beclin1/Atg5) biomarkers were highest in group 2, lowest in group 1 and significantly lower in group 4 than in group 3, whereas the LVEF exhibited an opposite pattern of oxidative stress (all p< 0.0001).

CONCLUSION

iPS-MSC^dOex-mIRs therapy was superior to iPS-MSC therapy for preserving LV function in DCM rat.

Low-Dose Empagliflozin Improves Systolic Heart Function after Myocardial Infarction in Rats: Regulation of MMP9, NHE1, and SERCA2a

The effects of the selective sodium-glucose cotransporter 2 (SGLT2) inhibitor empagliflozin in low dose on cardiac function were investigated in normoglycemic rats. Cardiac parameters were measured by intracardiac catheterization 30 min after intravenous application of empagliflozin to healthy animals. Empagliflozin increased the ventricular systolic pressure, mean pressure, and the max dP/dt (p < 0.05). Similarly, treatment with empagliflozin (1 mg/kg, p.o.) for one week increased the cardiac output, stroke volume, and fractional shortening (p < 0.05). Myocardial infarction (MI) was induced by ligation of the left coronary artery. On day 7 post MI, empagliflozin (1 mg/kg, p.o.) improved the systolic heart function as shown by the global longitudinal strain (−21.0 ± 1.1% vs. −16.6 ± 0.7% in vehicle; p < 0.05). In peri-infarct tissues, empagliflozin decreased the protein expression of matrix metalloproteinase 9 (MMP9) and favorably regulated the cardiac transporters sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA2a) and sodium hydrogen exchanger 1 (NHE1). In H9c2 cardiac cells, empagliflozin decreased the MMP2,9 activity and prevented apoptosis. Empagliflozin did not alter the arterial stiffness, blood pressure, markers of fibrosis, and necroptosis. Altogether, short-term treatment with low-dose empagliflozin increased the cardiac contractility in normoglycemic rats and improved the systolic heart function in the early phase after MI. These effects are attributed to a down-regulation of MMP9 and NHE1, and an up-regulation of SERCA2a. This study is of clinical importance because it suggests that a low-dose treatment option with empagliflozin may improve cardiovascular outcomes post-MI. Down-regulation of MMPs could be relevant to many remodeling processes including cancer disease.

Sodium-Glucose CoTransporter-2 Inhibitor Empagliflozin Ameliorates Sunitinib-Induced Cardiac Dysfunction via Regulation of AMPK-mTOR Signaling Pathway-Mediated Autophagy

Background: Sodium–glucose cotransporter-2 (SGLT2) inhibitors have been shown to decrease the adverse cardiac events and risks of cardiovascular mortality among patients with or without diabetes, which has made these drugs promising treatment options for patients with chronic heart failure. Cardiac dysfunction is a common and severe side effect induced by cancer chemotherapies, which seriously affects the prognosis and life quality of tumor patients. However, it is not clear whether SGLT2 inhibitors have cardiovascular benefits in patients with cancer chemotherapy–related cardiac dysfunction. We aimed to determine whether empagliflozin (EMPA), an SGLT2 inhibitor, has a protective role against sunitinib (SNT)-induced cardiac dysfunction in a mouse model.

Methods: Male C57BL/6J mice were randomized into control (control, n = 8), empagliflozin (EMPA, n = 8), sunitinib (SNT, n = 12), or sunitinib and empagliflozin coadministration (SNT + EMPA, n = 12) groups. EMPA, SNT, or SNT-combined EMPA was given via oral gavage for consecutive 28 days. Cardiovascular functions and pathological changes were examined, and the underlying mechanisms of EMPA’s effects were investigated in H9c2 cardiomyocytes.

Results: Mice in the SNT group exhibited dramatically elevated blood pressure (systolic blood pressure [SBP] 134.30 ± 6.455 mmHg vs. 114.85 ± 6.30 mmHg) and impaired left ventricular function (left ventricular ejection fraction [LVEF] 50.24 ± 3.06% vs. 84.92 ± 2.02%), as compared with those of the control group. However, EMPA could ameliorate SNT-induced cardiotoxicity, both in terms of SBP (117.51 ± 5.28 mmHg vs. 134.30 ± 6.455 mmHg) and LVEF (76.18 ± 5.16% vs. 50.24 ± 3.06 %). In H9c2 cardiomyocytes, SNT-induced cardiomyocyte death and cell viability loss as well as dysfunction of adenosine 5’-monophosphate–activated protein kinase–mammalian target of rapamycin (AMPK-mTOR) signaling–mediated autophagy were restored by EMPA. However, these favorable effects mediated by EMPA were blocked by the inhibition of AMPK or autophagy.

Conclusion: EMPA could ameliorate SNT-induced cardiac dysfunction via regulating cardiomyocyte autophagy, which was mediated by the AMPK-mTOR signaling pathway. These findings supported that SGLT2 inhibitor therapy could be a potential cardioprotective approach for cardiovascular complications among patients receiving SNT. However, these favorable effects still need to be validated in clinical trials.

Advances in Liver Cancer Stem Cell Isolation and their Characterization

Over the last decade research on cancer stem cells (CSC) significantly contributed to a better understanding of tumor biology. Given their similarity to normal stem cells, i.e. self-renewal and pluripotency the need arises to develop robust protocols for the isolation and characterization of CSCs. As with other malignancies, hepatic tumors are composed of a heterogeneous population of cells including liver cancer stem cells (LCSC). Yet, a precise understanding of why stem cells become cancerous is still lacking. There is unmet need to develop robust protocols for the successful isolation of LCSCs from human tissue resection material as to assist in the development of molecular targeted therapies. Here we review the research progress made in the isolation and characterization of LCSCs by considering a wide range of cell surface markers and sorting methods, as applied to side populations, microsphere cultures and the gradient centrifugation method. We emphasize the different fluorescence activated cell sorting methods and the possibility to enrich LCSCs by immunomagnetic beads. We review the specificity of functional assays by considering ABCG transporter and ALDH1 enzyme activities and evaluate the in vivo tumorigenicity of LCSCs in highly sensitive bioassays. Finally, we evaluate different LCSC markers in association with viral and non-viral liver disease and explore the potential of novel drug delivery systems targeting CD133, EpCAM, CD13 and CD90 for the development of molecular targeted therapies. Graphical Abstract.

Cardiorenal Syndrome in Type 2 Diabetes Mellitus - Rational Use of Sodium-glucose Cotransporter-2 Inhibitors

Cardiorenal syndrome (CRS) in people with type 2 diabetes mellitus (T2DM) illustrates the bidirectional link between the heart and the kidneys, with acute or chronic dysfunction of one organ adversely impacting the function of the other. Of the five subtypes identified, type 1 and 2 CRS occur because of the adverse impact of cardiac conditions on the kidneys. Type 3 and 4 occur when renal conditions affect the heart, and in type 5, systemic conditions impact the heart and kidneys concurrently. The cardiovascular and renoprotective benefits evidenced with sodium-glucose cotransporter-2 (SGLT2) inhibitors make them a potential choice in the management of CRS. Cardiovascular protection is mediated by a reduction in cardiac workload, blood pressure, and body weight; with improvement in lipid profile, uric acid levels, and adaptive ketogenesis process. Renoprotection is facilitated by reduction in albuminuria and hypoxic stress, and restoration of tubuloglomerular feedback. The favourable effect on cardiovascular complications and death, as well as renal complications and progression to end-stage kidney disease, has been confirmed in clinical trials. Guidelines endorse first-line use of SGLT2 inhibitors after metformin in patients with T2DM with high cardiovascular risk, chronic kidney disease or both. Since most trials with SGLT2 inhibitors excluded subjects with acute illness, patients with CRS subtypes 1 and 3 have not been studied adequately, making SGLT2 initiation in clinical practice challenging. Ongoing trials may provide evidence for SGLT2 inhibitor use in CRS. This review aims to enhance understanding of CRS and provide guidance for judicious use of SGLT2 inhibitors in T2DM.

SGLT2 Inhibitor Empagliflozin and DPP4 Inhibitor Linagliptin Reactivate Glomerular Autophagy in db/db Mice, a Model of Type 2 Diabetes

Recent data have indicated the emerging role of glomerular autophagy in diabetic kidney disease. We aimed to assess the effect of the SGLT2 inhibitor empagliflozin, the DPP4 inhibitor linagliptin, and their combination, on glomerular autophagy in a model of type 2 diabetes. Eight-week-old male db/db mice were randomly assigned to treatment with empagliflozin, linagliptin, empagliflozin–linagliptin or vehicle for 8 weeks. Age-matched non-diabetic db/+ mice acted as controls. To estimate glomerular autophagy, immunohistochemistry for beclin-1 and LAMP-1 was performed. Podocyte autophagy was assessed by counting the volume density (Vv) of autophagosomes, lysosomes and autolysosomes by transmission electron microscopy. LC3B and LAMP-1, autophagy markers, and caspase-3 and Bcl-2, apoptotic markers, were evaluated in renal cortex by western blot. Vehicle-treated db/db mice had weak glomerular staining for beclin-1 and LAMP-1 and reduced Vv of autophagosomes, autolysosomes and lysosomes in podocytes. Empagliflozin and linagliptin, both as monotherapy and in combination, enhanced the areas of glomerular staining for beclin-1 and LAMP-1 and increased Vv of autophagosomes and autolysosomes in podocytes. Renal LC3B and Bcl-2 were restored in actively treated animals. LAMP-1 expression was enhanced in the empagliflozin group; caspase-3 expression decreased in the empagliflozin–linagliptin group only. Mesangial expansion, podocyte foot process effacement and urinary albumin excretion were mitigated by both agents. The data provide further explanation for the mechanism of the renoprotective effect of SGLT2 inhibitors and DPP4 inhibitors in diabetes.

The Role of AMPK Activation for Cardioprotection in Doxorubicin-Induced Cardiotoxicity

Doxorubicin is a commonly used chemotherapeutic agent for the treatment of a range of cancers, but despite its success in improving cancer survival rates, doxorubicin is cardiotoxic and can lead to congestive heart failure. Therapeutic options for this patient group are limited to standard heart failure medications with the only drug specific for doxorubicin cardiotoxicity to reach FDA approval being dexrazoxane, an iron-chelating agent targeting oxidative stress. However, dexrazoxane has failed to live up to its expectations from preclinical studies while also bringing up concerns about its safety. Despite decades of research, the molecular mechanisms of doxorubicin cardiotoxicity are still poorly understood and oxidative stress is no longer considered to be the sole evil. Mitochondrial impairment, increased apoptosis, dysregulated autophagy and increased fibrosis have also been shown to be crucial players in doxorubicin cardiotoxicity. These cellular processes are all linked by one highly conserved intracellular kinase: adenosine monophosphate-activated protein kinase (AMPK). AMPK regulates mitochondrial biogenesis via PGC1α signalling, increases oxidative mitochondrial metabolism, decreases apoptosis through inhibition of mTOR signalling, increases autophagy through ULK1 and decreases fibrosis through inhibition of TGFβ signalling. AMPK therefore sits at the control point of many mechanisms shown to be involved in doxorubicin cardiotoxicity and cardiac AMPK signalling itself has been shown to be impaired by doxorubicin. In this review, we introduce different agents known to activate AMPK (metformin, statins, resveratrol, thiazolidinediones, AICAR, specific AMPK activators) as well as exercise and dietary restriction, and we discuss the existing evidence for their potential role in cardioprotection from doxorubicin cardiotoxicity.

Empagliflozin Blunts Worsening Cardiac Dysfunction Associated With Reduced NLRP3 (Nucleotide-Binding Domain-Like Receptor Protein 3) Inflammasome Activation in Heart Failure

BACKGROUND

Although empagliflozin was shown to profoundly reduce cardiovascular events in diabetic patients and blunt the decline in cardiac function in nondiabetic mice with established heart failure (HF), the mechanism of action remains unknown.

METHODS AND RESULTS

We treated 2 rodent models of HF with 10 mg/kg per day empagliflozin and measured activation of the NLRP3 (nucleotide-binding domain-like receptor protein 3) inflammasome in the heart. We show for the first time that beneficial effects of empagliflozin in HF with reduced ejection fraction (HF with reduced ejection fraction [HFrEF]; n=30-34) occur in the absence of changes in circulating ketone bodies, cardiac ketone oxidation, or increased cardiac ATP production. Of note, empagliflozin attenuated activation of the NLRP3 inflammasome and expression of associated markers of sterile inflammation in hearts from mice with HFrEF, implicating reduced cardiac inflammation as a mechanism of empagliflozin that contributes to sustained function in HFrEF in the absence of diabetes mellitus. In addition, we validate that the beneficial cardiac effects of empagliflozin in HF with preserved ejection fraction (HFpEF; n=9-10) are similarly associated with reduced activation of the NLRP3 inflammasome. Lastly, the ability of empagliflozin to reduce inflammation was completely blunted by a calcium (Ca²⁺) ionophore, suggesting that empagliflozin exerts its benefit upon restoring optimal cytoplasmic Ca²⁺ levels in the heart.

CONCLUSIONS

These data provide evidence that the beneficial cardiac effects of empagliflozin are associated with reduced cardiac inflammation via blunting activation of the NLRP3 inflammasome in a Ca²⁺-dependent manner and hence may be beneficial in treating HF even in the absence of diabetes mellitus.

Norepinephrine turnover in the left ventricle of subtotally nephrectomized rats

Increased activity of the sympathetic nervous system (SNS) has been proposed as a risk factor for increased cardiovascular mortality in patients with chronic kidney disease (CKD). Information on the activity of cardiac sympathetic innervation is non-homogeneous and incomplete. The aim of our study was to evaluate the tonic effect of SNS on heart rate, norepinephrine turnover and direct and indirect effects of norepinephrine in left ventricles of subtotally nephrectomized rats (SNX) in comparison with sham-operated animals (SHAM). Renal failure was verified by measuring serum creatinine and urea levels. SNX rats developed increased heart rates and blood pressure (BP). The increase in heart rate was not caused by sympathetic overactivity as the negative chronotropic effect of metipranolol did not differ between the SNX and SHAM animals. The positive inotropic effects of norepinephrine and tyramine on papillary muscle were not significantly different. Norepinephrine turnover was measured after the administration of tyrosine hydroxylase inhibitor, pargyline, tyramine, desipramine, and KCl induced depolarization. The absolute amount of released norepinephrine was comparable in both groups despite a significantly decreased norepinephrine concentration in the cardiac tissue of the SNX rats. We conclude that CKD associated with renal denervation in rats led to adaptive changes characterized by an increased reuptake and intracellular norepinephrine turnover which maintained normal reactivity of the heart to sympathetic stimulation.

Empagliflozin, a sodium glucose co-transporter-2 inhibitor, alleviates atrial remodeling and improves mitochondrial function in high-fat diet/streptozotocin-induced diabetic rats

Background

Diabetes mellitus is an important risk factor for atrial fibrillation (AF) development. Sodium–glucose co-transporter-2 (SGLT-2) inhibitors are used for the treatment of type 2 diabetes mellitus (T2DM). Their cardioprotective effects have been reported but whether they prevent AF in T2DM patients are less well-explored. We tested the hypothesis that the SGLT-2 inhibitor, empagliflozin, can prevent atrial remodeling in a diabetic rat model.

Methods

High-fat diet and low-dose streptozotocin (STZ) treatment were used to induce T2DM. A total of 96 rats were randomized into the following four groups: (i) control (ii) T2DM, (iii) low-dose empagliflozin (10 mg/kg/day)/T2DM; and (iv) high-dose empagliflozin (30 mg/kg/day)/T2DM by the intragastric route for 8 weeks.

Results

Compared with the control group, left atrial diameter, interstitial fibrosis and the incidence of AF inducibility were significantly increased in the DM group. Moreover, atrial mitochondrial respiratory function, mitochondrial membrane potential, and mitochondrial biogenesis were impaired. Empagliflozin treatment significantly prevented the development of these abnormalities in DM rats, likely via the peroxisome proliferator-activated receptor-c coactivator 1α (PGC-1α)/nuclear respiratory factor-1 (NRF-1)/mitochondrial transcription factor A (Tfam) signaling pathway.

Conclusions

Empagliflozin can ameliorate atrial structural and electrical remodeling as well as improve mitochondrial function and mitochondrial biogenesis in T2DM, hence may be potentially used in the prevention of T2DM-related atrial fibrillation.

Effect of sodium glucose cotransporter 2 inhibitors on cardiac function and cardiovascular outcome: a systematic review

A high incidence of left ventricular diastolic dysfunction and increased risk of cardiovascular events have been reported in patients with diabetes mellitus. Sodium glucose cotransporter 2 (SGLT2) inhibitors selectively inhibit kidney glucose and sodium reabsorption, and cardiovascular benefits of SGLT2 inhibitors beyond other antidiabetic drugs have been reported in type 2 diabetes mellitus (T2DM) clinical trials. However, underlying mechanisms contributing to the improvement of cardiovascular outcomes have not been clearly identified. In this review, likely mechanisms of SGLT2 inhibitors contributing to a favorable cardiovascular outcomes are discussed based on experimental and clinical studies on cardiac function.

Empagliflozin reduces the levels of CD36 and cardiotoxic lipids while improving autophagy in the hearts of Zucker diabetic fatty rats

The EMPA-REG OUTCOME (Empagliflozin, Cardiovascular Outcome Event Trial in patients with Type 2 Diabetes Mellitus (T2DM)) trial made evident the potentiality of pharmacological sodium-glucose cotransporter 2 (SGLT2) inhibition for treating patients with diabetes and cardiovascular disease. Since the effect of empagliflozin or other SGLT2 inhibitors on the whole cardiac metabolic profile was never analysed before, and with the purpose to contribute to elucidate the benefits at cardiac level of the use of empagliflozin, we explored the effect of the treatment with empagliflozin for six weeks on the cardiac metabolomic profile of Zucker diabetic fatty rats, a model of early stage T2DM, using untargeted metabolomics approach. Empagliflozin reduced significantly the cardiac content of sphingolipids (ceramides and sphingomyelins) and glycerophospholipids (major bioactive contributing factors linking insulin resistance to cardiac damage) and decreased the cardiac content of the fatty acid transporter cluster of differentiation 36 (CD36); induced significant decreases of the cardiac levels of essential glycolysis intermediaries 2,3-bisphosphoglycerate and phosphoenolpyruvate, and regulated the abundance of several amino acids of relevance as tricarboxylic acid suppliers and/or in the metabolic control of the cardiac function as glutamic acid, gamma-aminobutyric acid and sarcosine. Empagliflozin treatment activated the cardioprotective master regulator of cellular energyhomeostasis AMP-activatedproteinkinase (AMPK) and enhanced autophagy at cardiac level, while it decreased significantly the cardiac mRNA levels of the pro-inflammatory cytokines interleukin-6 (IL-6), chemerin, TNF-α and MCP-1, reinforcing the hypothesis of a direct role for empagliflozin in attenuating cardiac inflammation. Our results provide an advancement on the knowledge of the mechanisms linking the therapy with empagliflozin with protective effects on the development of cardiometabolic diseases whose course is associated with remarkable cardiac bioenergetics dysregulation and disarrangement in cardiac metabolome and lipidome.

The therapeutic impact of entresto on protecting against cardiorenal syndrome-associated renal damage in rats on high protein diet

BACKGROUND

This study tested the hypothesis that Entresto could safely and effectively preserve heart and kidney function in rats with cardiorenal syndrome (CRS) induced by 5/6 nephrectomy and intra-peritoneal doxorubicin administration (accumulated dosage up to 7.5 mg/kg) together with daily high-protein-diet (H^PD).

METHODS AND RESULTS

Adult male Sprague-Dawley rats (n = 24) were equally categorized into Group 1 (sham-operated control + H^PD), Group 2 (CRS + H^PD) and Group 3 [CRS + H^PD + Entresto (100 mg/kg/day orally) since Day 14 after CRS induction] and euthanized by Day 63 after CRS induction. By Day 63, circulatory BUN and creatinine levels and ratios of urine protein to creatinine were significantly higher in Group 2 than those in Groups 1 and 3, and significantly higher in Group 3 than in Group 1, whereas left-ventricular ejection fraction and kidney weight showed an opposite pattern among all groups (all p < 0.001). Microscopically, fibrosis area and intensity of oxidative stress (i.e., DCFDA stain) in kidney/heart tissues exhibited a pattern identical to that of creatinine level among all groups (all p < 0.0001). Kidney injury score and protein expressions of autophagy (i.e., beclin-1/Atg-5/protein ratio of LC3-BII/LC3-BI), fibrosis (Smad3/TGF-ß), apoptosis (mitochondrial-Bax/capase2/3/9), oxidative-stress (NOX-4/oxidized protein/xanthine-oxidase/catalase), membranous p47phox phosphorylation and mitochondrial-damage biomarker (cytosolic-cytochrome-C) were higher in Group 2 than those in Groups 1 and 3, and significantly higher in Group 3 than in Group 1, while protein expressions of anti-apoptosis (Bcl-2/Bcl-XL) and mitochondrial integrity (mitochondrial-cytochrome-C) markers displayed an opposite pattern among all groups in kidney tissues (all p < 0.0001).

CONCLUSION

Oral administration of entresto was safe and could offer protection against CRS-induced heart and kidney damage.