SGLT2 Inhibitors as a Therapeutic Option for Diabetic Nephropathy

Quercetin prevented diabetic nephropathy by inhibiting renal tubular epithelial cell apoptosis via the PI3K/AKT pathway

Diabetic nephropathy (DN) is the most common and serious complication of diabetes, posing a significant threat to human health. Currently, safe and effective preventive strategies for DN are lacking. The study aimed to explore the preventive effect and the underlying mechanism of quercetin against DN. In the in vivo experiments, we established a mouse model of type 2 diabetes mellitus (T2DM) induced by a combination of high-fat diet (HFD) and streptozotocin (STZ) to explore the preventive effect of quercetin on DN and its protective role against renal tubular epithelial cell apoptosis. Subsequently, in vitro experiments using human tubular epithelial cells (HK-2 cells) were conducted to further validate the protective effects of quercetin on renal tubular epithelial cell apoptosis. Additionally, we employed RNA sequencing analysis (RNA-seq) and network pharmacology analysis to comprehensively elucidate the molecular mechanisms involved. In vivo, we observed a significant increase in the ratio of urinary microalbumin to creatinine in diabetic mice compared to control mice, accompanied by the activation of renal tubular epithelial cell apoptosis. Remarkably, all of these changes were reversed after quercetin treatment. In vitro, high-glucose-induced apoptosis in HK-2 cells was significantly attenuated by quercetin. Subsequent RNA sequencing analysis and network pharmacology analysis revealed that quercetin was most likely to inhibit high-glucose-induced HK-2 cell apoptosis through the PI3K/AKT signaling pathway. Western Blotting results further demonstrated that quercetin could inhibit the activation of the PI3K/AKT signaling pathway in HK-2 cells induced by high glucose. Our results supported that quercetin could prevent DN by inhibiting tubular epithelial cell apoptosis via the PI3K/AKT pathway. Quercetin might be a promising candidate for the prevention of DN.

Plasma angiotensin-converting enzyme 2 (ACE2) is a marker for renal outcome of diabetic kidney disease (DKD) (U-CARE study 3)

INTRODUCTION

ACE cleaves angiotensin I (Ang I) to angiotensin II (Ang II) inducing vasoconstriction via Ang II type 1 (AT1) receptor, while ACE2 cleaves Ang II to Ang (1-7) causing vasodilatation by acting on the Mas receptor. In diabetic kidney disease (DKD), it is still unclear whether plasma or urine ACE2 levels predict renal outcomes or not.

RESEARCH DESIGN AND METHODS

Among 777 participants with diabetes enrolled in the Urinary biomarker for Continuous And Rapid progression of diabetic nEphropathy study, the 296 patients followed up for 9 years were investigated. Plasma and urinary ACE2 levels were measured by the ELISA. The primary end point was a composite of a decrease of estimated glomerular filtration rate (eGFR) by at least 30% from baseline or initiation of hemodialysis or peritoneal dialysis. The secondary end points were a 30% increase or a 30% decrease in albumin-to-creatinine ratio from baseline to 1 year.

RESULTS

The cumulative incidence of the renal composite outcome was significantly higher in group 1 with lowest tertile of plasma ACE2 (p=0.040). Group 2 with middle and highest tertile was associated with better renal outcomes in the crude Cox regression model adjusted by age and sex (HR 0.56, 95% CI 0.31 to 0.99, p=0.047). Plasma ACE2 levels demonstrated a significant association with 30% decrease in ACR (OR 1.46, 95% CI 1.044 to 2.035, p=0.027) after adjusting for age, sex, systolic blood pressure, hemoglobin A1c, and eGFR.

CONCLUSIONS

Higher baseline plasma ACE2 levels in DKD were protective for development and progression of albuminuria and associated with fewer renal end points, suggesting plasma ACE2 may be used as a prognosis marker of DKD.

TRIAL REGISTRATION NUMBER

UMIN000011525.

Diabetes and Renal Complications: An Overview on Pathophysiology, Biomarkers and Therapeutic Interventions

Diabetic kidney disease (DKD) is a major microvascular complication of both type 1 and type 2 diabetes. DKD is characterised by injury to both glomerular and tubular compartments, leading to kidney dysfunction over time. It is one of the most common causes of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Persistent high blood glucose levels can damage the small blood vessels in the kidneys, impairing their ability to filter waste and fluids from the blood effectively. Other factors like high blood pressure (hypertension), genetics, and lifestyle habits can also contribute to the development and progression of DKD. The key features of renal complications of diabetes include morphological and functional alterations to renal glomeruli and tubules leading to mesangial expansion, glomerulosclerosis, homogenous thickening of the glomerular basement membrane (GBM), albuminuria, tubulointerstitial fibrosis and progressive decline in renal function. In advanced stages, DKD may require treatments such as dialysis or kidney transplant to sustain life. Therefore, early detection and proactive management of diabetes and its complications are crucial in preventing DKD and preserving kidney function.

Effect of dapagliflozin on collectins and complement activation in plasma from patients with type 2 diabetes and albuminuria: Data from the DapKid cohort

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT- 2) inhibitors exert cardiovascular and kidney-protective effects in people with diabetes. Attenuation of inflammation could be important for systemic protection. The lectin pathway of complement system activation is linked to diabetic nephropathy. We hypothesized that SGLT-2 inhibitors lower the circulating level of pattern-recognition molecules of the lectin cascade and attenuate systemic complement activation.

METHODS

Analysis of paired plasma samples from the DapKid crossover intervention study where patients with type 2 diabetes mellitus (T2DM) and albuminuria were treated with dapagliflozin and placebo for 12 weeks (10 mg/day, n=36). ELISA was used to determine concentrations of collectin kidney 1 (CL-K1), collectin liver 1 (CL-L1), mannose-binding lectin (MBL), MBL-associated serine protease 2 (MASP-2), the anaphylatoxin complement factor 3a (C3a), the stable C3 split product C3dg and the membrane attack complex (sC5b-9).

RESULTS

As published before, dapagliflozin treatment lowered Hba1C from 74 (14.9) mmol/mol to 66 (13.9) mmol/mol (p<0.0001), and the urine albumin/creatinine ratio from 167.8 mg/g to 122.5 mg/g (p<0.0001). Plasma concentrations of CL-K1, CL-L1, MBL, and MASP-2 did not change significantly after dapagliflozin treatment (P>0.05) compared to placebo treatment. The plasma levels of C3a (P<0.05) and C3dg (P<0.01) increased slightly but significantly, 0.6 [0.2] units/mL and 76 [52] units/mL respectively, after dapagliflozin treatment. The C9-associated neoepitope in C5b-9 did not change in plasma concentration by dapagliflozin (P>0.05).

CONCLUSION

In patients with type 2 diabetes and albuminuria, SGLT-2 inhibition resulted in modest C3 activation in plasma, likely not driven by primary changes in circulating collectins and not resulting in changes in membrane attack complex. Based on systemic analyses, organ-specific local protective effects of gliflozins against complement activation cannot be excluded.

Sotagliflozin versus dapagliflozin to improve outcome of patients with diabetes and worsening heart failure: a cost per outcome analysis

Background and aim

Dapagliflozin inhibits the sodium-glucose cotransporter protein 2 (SGLT-2), while sotagliflozin, belonging to a new class of dual-acting SGLT-1/SGLT-2 inhibitors, has garnered considerable attention due to its efficacy and safety. Both Dapagliflozin and sotagliflozin play a significant role in treating worsening heart failure in diabetes/nondiabetes patients with heart failure. Therefore, this article was to analyze and compare the cost per outcome of both drugs in preventing one event in patients diagnosed with diabetes-related heart failure.

Method

The Cost Needed to Treat (CNT) was employed to calculate the cost of preventing one event, and the Number Needed to Treat (NNT) represents the anticipated number of patients requiring the intervention treatment to prevent a single adverse event, or the anticipated number of patients needing multiple treatments to achieve a beneficial outcome. The efficacy and safety data were obtained from the results of two published clinical trials, DAPA-HF and SOLOIST-WHF. Due to the temporal difference in the drugs' releases, we temporarily analyzed the price of dapagliflozin to calculate the price of sotagliflozin within the same timeframe. The secondary analyses aimed to assess the stability of the CNT study and minimize differences between the results of the RCT control and trial groups, employing one-way sensitivity analyses.

Result

The final results revealed an annualized Number Needed to Treat (aNNT) of 4 (95% CI 3-7) for preventing one event with sotagliflozin, as opposed to 23 (95% CI 16-55) for dapagliflozin. We calculated dapagliflozin's cost per prevented event (CNT) to be $109,043 (95% CI $75,856-$260,755). The price of sotagliflozin was set below $27,260, providing a favorable advantage. Sensitivity analysis suggests that sotagliflozin may hold a cost advantage.

Conclusion

In this study, sotagliflozin was observed to exhibit a price advantage over dapagliflozin in preventing one events, cardiovascular mortality, or all-cause mortality in patients with diabetes.

Association of SGLT2 inhibitor dapagliflozin with risks of acute kidney injury and all-cause mortality in acute myocardial infarction patients

OBJECTIVE

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have well-documented effects in reducing hospitalization or cardiovascular mortality, while the association of SGLT2 inhibitor dapagliflozin (DAPA) and the risk of acute kidney injury (AKI) in acute myocardial infarction (AMI) patients has not been comprehensively investigated. Therefore, we aimed to assess the association between DAPA and AKI risk in AMI patients after percutaneous coronary intervention (PCI) therapy.

METHODS

Using the Changzhou Acute Myocardial Infarction Registry database, we retrospectively included AMI patients from January 2017 to August 2021 and analyzed the risk of AKI and all-cause mortality after PCI therapy. The patients were divided into two groups according to the use of DAPA (DAPA group and Ctrl group). Patients in the DAPA group started to use DAPA after admission and continued its use during hospitalization and follow-up period. Baseline characteristics were balanced between the two groups with a propensity score matching (PSM) analysis. The outcome was AKI within 7 days after PCI and all-cause mortality during a follow-up of 2 years. Univariate and multivariate logistic regression analyses were used to assess the association between DAPA and AKI risk.

RESULTS

A total of 1839 AMI patients undergoing PCI were enrolled. DAPA was used in 278 (15.1%) patients. Postoperative AKI occurred in 351 (19.1%) cases. A 1:1 PSM analysis was used to reduce confounding factors. The multivariate stepwise regression analysis showed that DAPA (odds ratio, OR 0.66; 95% confidence interval, CI 0.44-0.97; P = 0.036) was an independent protective factor in the entire cohort. After matching, the use of DAPA in AMI patients was independently associated with a decline of AKI risk (OR 0.32; 95% CI, 0.19-0.53; P < 0.001) after hospital admission. Meanwhile, there were significant differences in mortality between the DAPA group and Ctrl group (2.5% vs. 7.6%, P = 0.012).

CONCLUSION

SGLT2 inhibitor DAPA was associated with lower risks of incident AKI and all-cause mortality in AMI patients after PCI therapy.

Identification of phytocompounds as potent inhibitors of sodium/glucose cotransporter-2 leading to diabetes treatment

Type-II diabetes, a major metabolic disorder has threatened the very existence of a healthy life since long ago. Commercially available antidiabetic drugs are known for several adverse effects. The present study attempted to identify potential phytocompounds as inhibitors of sodium/glucose cotransporter-2 (SGLT2), a major protein that helps in glucose re-absorption from renal tubules. A total of 28 phytocompounds were collected based on the literature survey. 3D co-ordinates of phytocompounds were collected from PubChem database. Molecular docking was carried out with SGLT2 protein and the best 3 docking complexes were subjected to molecular dynamics simulation for 100 ns. Free energy changes were also analyzed using MM/PBSA analysis. Phytocompounds were also analyzed for their drug-likeness and ADMET properties. Docking study observed a strong binding affinity of phytocompounds (> -7.0 kcal/mol). More than 10 phytocompounds showed better binding affinity compared to reference drugs. Further analysis of three best docking complexes when analyzed by MD simulation showed better stability and compactness of the complexes compared to reference drug, empagliflozin. MM/PBSA analysis also revealed that van der Waals force and electrostatic energy are the major binding energy involved in the complex formation. Like docking energy, free energy analysis also observed stronger binding energies (ΔGGAS) in SGLT2-phytocompound complexes compared to empagliflozin complex. All the phytocompounds showed drug-likeness and considerable ADMET properties. The study, therefore, suggests that Trifolirhizin-6'-monoacetate, Aspalathin, and Quercetin-3-glucoside could be a possible inhibitor of SGLT2 protein. However, further studies need to be carried out to reveal the exact mode of activity.Communicated by Ramaswamy H. Sarma.

Dapagliflozin mitigates oxidative stress, inflammatory, and histopathological markers of aging in mice

Aging, a complex physiological process affecting all living things, is a major area of research, particularly focused on interventions to slow its progression. This study assessed the antiaging efficacy of dapagliflozin (DAPA) on various aging-related parameters in a mouse model artificially induced to age. Forty male Swiss albino mice were randomly divided into four groups of ten animals each. The control group (Group I) received normal saline. The aging model group (Group II) was administered D-galactose orally at 500mg/kg to induce aging. Following the aging induction, the positive control group received Vitamin C supplementation (Group III), while the DAPA group (Group IV) was treated with dapagliflozin. The inflammatory mediators (TNF-α and IL-1β) showed similar patterns of change. No statistically significant difference was observed between groups III and IV. Both groups had significantly lower values compared to GII, while it was significantly higher compared to GI. Glutathione peroxidase (GSH-Px) showed no statistically significant difference between groups GIII and GIV, but it was higher in GIII compared to GII and significantly lower in GIII compared to GI. The study demonstrated that dapagliflozin exerts a beneficial impact on many indicators of aging in mice. The intervention resulted in a reduction in hypertrophy in cardiomyocytes, an enhancement in skin vitality, a decrease in the presence of inflammatory mediators, and an improvement in the efficacy of antioxidants.

Cognitive Benefits of Sodium-Glucose Co-Transporters-2 Inhibitors in the Diabetic Milieu

Patients with diabetes are at higher risk of cognitive impairment and memory loss than the normal population. Thus, using hypoglycemic agents to improve brain function is important for diabetic patients. Sodium-glucose cotransporters-2 inhibitors (SGLT2i) are a class of therapeutic agents used in the management of diabetes that has some pharmacologic effects enabling them to fight against the onset and progress of memory deficits. Although the exact mediating pathways are not well understood, emerging evidence suggests that SGLT2 inhibition is associated with improved brain function. This study reviewed the possible mechanisms and provided evidence suggesting SGLT2 inhibitors could ameliorate cognitive deficits.

Protective Effects of Home T2DM Treatment with Glucagon-Like Peptide-1 Receptor Agonists and Sodium-Glucose Co-transporter-2 Inhibitors Against Intensive Care Unit Admission and Mortality in the Acute Phase of the COVID-19 Pandemic: A Retrospective Observational Study in Italy

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is a relevant risk factor for severe forms of COVID-19 (SARS coronavrus 2 [SARS-CoV-2] disease 2019), and calls for caution because of the high prevalence of T2DM worldwide and the high mortality rates observed in patients with T2DM who are infected with SARS-CoV-2. People with T2DM often take dipeptidyl peptidase-4 inhibitors (DPP-4is), glucagon-like peptide-1 receptor agonists (GLP-1ras), or sodium-glucose co-transporter-2 inhibitors (SGLT-2is), all of which have clear anti-inflammatory effects. The study aimed to compare (i) the severity and duration of hospital stay between patients with T2DM categorized by pre-hospitalization drug class utilization and (ii) the COVID-19-related death rates of those three groups.

METHODS

We designed an observational, retrospective, multi-center, population-based study and extracted the hospital admission data from the health care records of 1916 T2DM patients over 18 years old who were previously on GLP-1ra, SGLT-2i, or DPP-4i monotherapy and were hospitalized for COVID-19 (diagnosis based on ICD.9/10 codes) between January 2020 and December 2021 in 14 hospitals throughout Italy. We analyzed general data, pre-admission treatment schedules, date of admission or transfer to the intensive care unit (ICU) (i.e., the index date; taken as a marker of increased COVID-19 disease severity), and death (if it had occurred). Statistics analyzed the impact of drug classes on in-hospital mortality using propensity score logistic regressions for (i) those admitted to intensive care and (ii) those not admitted to intensive care, with a random match procedure used to generate a 1:1 comparison without diabetes cohort replacement for each drug therapy group by applying the nearest neighbor method. After propensity score matching, we checked the balance achieved across selected variables if a balance was ever achieved. We then used propensity score matching between the three drug classes to assemble a sample in which each patient receiving an SGLT-2i was matched to one on a GLP-1ra, and each patient on a DPP-4i was matched to one on a GLP-1ra, adjusting for covariates. We finally used GLP-1ras as references in the logistic regression.

RESULTS

The overall mortality rate (MR) of the patients was 14.29%. The MR in patients with COVID was 53.62%, and it was as high as 42.42% in the case of associated T2DM, regardless of any glucose-lowering therapy. In those on DPP-4is, there was excess mortality; in those treated with GLP-1ras and SGLT-2is, the death rate was significantly lower, i.e., almost a quarter of the overall mortality observed in COVID-19 patients with T2DM. Indeed, the odds ratio (OR) in the logistic regression resulted in an extremely high risk of in-hospital death in individuals previously treated with DPP-4is [incidence rate (IR) 4.02, 95% confidence interval (CI) 2.2-5.7) and only a slight, nonsignificantly higher risk in those previously treated with SGLT-2is (IR 1.42, 95% CI 0.6-2.1) compared to those on GLP-1ras. Moreover, the longer the stay, the higher the death rate, which ranged from 22.3% for ≤ 3-day stays to 40.3% for 4- to 14-day stays (p < 0.01 vs. the former) and 77.4% for over-14-day stays (p < 0.001 vs. both the others).

DISCUSSION

Our data do not support a protective role of DPP-4is; indeed, this role has already been questioned due to previous observations. However, the data do show a strong protective effect of SGLT-2is and GLP-1ras. Beyond lowering circulating glucose levels, those two drug classes were found to exert marked anti-phlogistic effects: SGLT-2is increased adiponectin and reduced urate, leptin, and insulin concentrations, thus positively affecting overall low-grade inflammation, and GLP-1ras may also greatly help at the lung tissue level, meaning that their extra-glycemic effects extend well beyond those acknowledged in the cardiovascular and renal fields.

CONCLUSIONS

The aforedescribed observational clinical data relating to a population of Italian inpatients with T2DM suggest that GLP-1ras and SGLT-2is can be considered antidiabetic drugs of choice against COVID-19, and might even prove beneficial in the event of any upcoming pandemic that has life-threatening effects on the pulmonary and cardiovascular systems.

Comprehensive advancements in the prevention and treatment of diabetic nephropathy: A narrative review

Diabetic nephropathy (DN) is a common and severe complication of diabetes mellitus and is the leading cause of chronic kidney disease (CKD) worldwide. Despite current treatments, many individuals with DN progress to end-stage renal disease (ESRD), requiring dialysis or kidney transplantation. The advancement in our understanding of the pathogenesis of diabetic nephropathy has led to the development of new prevention and treatment strategies. We comprehensively reviewed the literature on advances in the prevention and treatment of DN. We searched PubMed, Scopus, and Web of Science databases for articles published between 2000 and 2023, using keywords such as "diabetic nephropathy," "prevention," "treatment," and "recent advances." The recent advances in the prevention and treatment of DN include novel approaches targeting inflammation and fibrosis, such as inhibitors of the nuclear factor kappa-B (NF-kB) pathway, inhibitors of the transforming growth factor-beta (TGF-beta) pathway, and anti-inflammatory cytokines. Other promising strategies include stem cell therapy, gene therapy, and artificial intelligence-based approaches, such as predictive models based on machine learning algorithms that can identify individuals at high risk of developing DN and guide personalized treatment strategies. Combination therapies targeting multiple disease pathways may also offer the most significant potential for improving outcomes for individuals with DN. Overall, the recent advances in the prevention and treatment of DN represent promising avenues for future research and clinical development. Novel therapies targeting inflammation and fibrosis, stem cell and gene therapies, and artificial intelligence-based approaches all show great potential for improving outcomes for individuals with DN.

Efficacy and Safety of Sodium-Glucose Cotransporter-2 Inhibitors in Nondiabetic Patients with Chronic Kidney Disease: A Review of Recent Evidence

Background

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) were initially developed as glucose-lowering agents in patients with type-2 diabetes. However, available data from clinical trials and meta-analyses suggest that SGLT2i have pleiotropic benefits in reducing mortality and delaying the progression of chronic kidney disease (CKD) in both diabetic and nondiabetic patients. Thus, we herein review the current evidence regarding the efficacy and safety of SGLT2i in patients with nondiabetic CKD and appraise the recently reported clinical trials that might facilitate the management of CKD in routine clinical practice.

Summary

The benefits of SGLT2i on nondiabetic CKD are multifactorial and are mediated by a combination of mechanisms. The landmark DAPA-CKD trial revealed that dapagliflozin administered with renin-angiotensin system blockade drugs reduced the risk of a sustained decline (at least 50%) in the estimated glomerular filtration rate, end-stage kidney disease, or death from cardiorenal causes. The recent EMPA-KIDNEY trial showed that empagliflozin therapy led to a lower risk of progression of kidney disease or death from cardiovascular causes. These benefits were consistent in patients with and without diabetes. Moreover, a meta-analysis of DAPA-HF and EMPEROR-Reduced trials confirmed reductions in the combined risk of cardiovascular death or worsening heart failure including composite renal endpoint.

Key Messages

Considering the robust data available from DAPA-CKD, EMPA-KIDNEY, and other trials such as EMPEROR-Preserved, DIAMOND that included nondiabetic patients, it may be necessary to update current guidelines to include SGLT2i as a first-line therapy for CKD and reevaluate current CKD therapeutic approaches.

Promising renoprotective effect of gold nanoparticles and dapagliflozin in diabetic nephropathy via targeting miR-192 and miR-21

Diabetic nephropathy (DN) is a worldwide issue that eventually leads to end-stage renal failure, with limited therapeutic options. Prior research has revealed that gold nanoparticles (AuNPs) have a substantial antidiabetic impact. In addition, sodium-glucose cotransporter2 (SGLT2) inhibitors, including dapagliflozin (DAPA), had renoprotective impact on DN. Therefore, this research attempted to determine the potential AuNPs and DAPA impacts in ameliorating experimentally DN induction and the underlying mechanisms focusing on miR-192 and miR-21, correlating them with autophagy, apoptosis, fibrosis, and oxidative stress. Diabetes induction was through a single intraperitoneal streptozotocin (55 mg/kg) injection, and rats with diabetes received AuNPs (2.5 mg/kg/day) as well as DAPA (2 mg/kg/day) for 7 weeks as a treatment. AuNPs and DAPA treatment for 7 weeks substantially alleviated DN. AuNPs and DAPA significantly increased catalase (CAT) activity as well as serum total antioxidant capacity (TAC), along with a substantial decline in malondialdehyde (MDA). AuNPs and DAPA treatment alleviated renal fibrosis as they decreased transforming growth factorß1(TGF-ß1) as well as matrix metalloproteinase-2 (MMP-2) renal expression, decreased apoptosis through alleviating the proapoptotic gene (caspase-3) renal expression and increased the antiapoptotic gene (Bcl-2) renal expression, and increased autophagy as they increased LC-3 as well as Beclin-1 renal expression. Autophagy activation, inhibition of apoptosis, and renal fibrosis could be due to their inhibitory impact on miR-192 and miR-21 renal expression. AuNPs and DAPA have a protective effect on DN in rats by targeting miR-192 and miR-21 and their downstream pathways, including fibrosis, apoptosis, autophagy, and oxidative stress.

Diabetic complications and prospective immunotherapy

The incidence of Diabetes Mellitus is increasing globally. Individuals who have been burdened with diabetes for many years often develop complications as a result of hyperglycemia. More and more research is being conducted highlighting inflammation as an important factor in disease progression. In all kinds of diabetes, hyperglycemia leads to activation of alternative glucose metabolic pathways, resulting in problematic by-products including reactive oxygen species and advanced glycation end products. This review takes a look into the pathogenesis of three specific diabetic complications; retinopathy, nephropathy and neuropathy as well as their current treatment options. By considering recent research papers investigating the effects of immunotherapy on relevant conditions in animal models, multiple strategies are suggested for future treatment and prevention of diabetic complications with an emphasis on molecular targets associated with the inflammation.

Recent Pharmacological Options in Type 2 Diabetes and Synergic Mechanism in Cardiovascular Disease

Diabetes Mellitus is a multifactorial disease with a critical impact worldwide. During prediabetes, the presence of various inflammatory cytokines and oxidative stress will lead to the pathogenesis of type 2 diabetes. Furthermore, insulin resistance and chronic hyperglycemia will lead to micro- and macrovascular complications (cardiovascular disease, heart failure, hypertension, chronic kidney disease, and atherosclerosis). The development through the years of pharmacological options allowed us to reduce the persistence of chronic hyperglycemia and reduce diabetic complications. This review aims to highlight the specific mechanisms with which the new treatments for type 2 diabetes reduce oxidative stress and insulin resistance and improve cardiovascular outcomes.

Effect of sodium-glucose cotransporter 2 inhibitors on the rate of decline in kidney function: A systematic review and meta-analysis

AIM

To investigate the influence of sodium/glucose cotransporter-2 inhibitors (SGLT-2i) on renal function during the course of its administration, particularly in the initial weeks.

MATERIALS AND METHODS

Randomized controlled trials (RCTs) related to SGLT-2i were searched in databases (MEDLINE, EMBASE, and Cochrane Central Register) from the database's inception to August 31, 2021. All RCTs reported the kidney outcomes of SGLT2i versus active or placebo control were included, regardless of the presence of diabetes in the patients and the baseline estimated glomerular filtration rate (eGFR). The Cochrane Collaboration risk of bias tool was used to assess the quality of the included studies. All outcome comparisons were performed using the RevMan 5.4 software.

RESULTS

Eleven RCTs with 58 534 participants reporting prespecified renal outcomes were identified. There was no heterogeneity in the baseline eGFR and urine albumin-to-creatinine ratio in the included studies. In the initial 2-4 weeks, there was an acute decline of eGFR in the SGLT-2i group compared with placebo group (weighted mean difference [WMD] -3.35 ml/min/1.73 m² ; 95% CI, -3.81 to -2.90; I²  = 35%, p = .15); When compared to baseline eGFR in the SGLT-2i group, the WMD was -4.02 ml/min/1.73 m² (95% confidence interval [CI], -3.61 to -4.44; I²  = 0%, p = .45). The renoprotective effect gradually appeared, and the decline rate of eGFR in the SGLT-2i group was sustained slower than placebo. However, the statistically significant benefit of SGLT-2i did not appear until the 104th week (the second year) (WMD 0.35 ml/min/1.73 m² , 95% CI, 0.04 to 0.66; I²  = 45%, p = .08). Subgroup analysis showed SGLT-2i had a similar benefit on renal function regardless of baseline eGFR values.

CONCLUSION

SGLT-2i consistently slowed the deterioration of eGFR since the early stage of administration, even in patients with chronic kidney disease. However, there was an acute decline in eGFR in the initial 2-4 weeks; afterwards the renoprotective effect of SGLT-2i gradually appeared and remained stable in the next few years.

The antioxidative effects of empagliflozin on high glucose‑induced epithelial-mesenchymal transition in peritoneal mesothelial cells via the Nrf2/HO-1 signaling

High glucose (HG)-induced epithelial-mesenchymal transition (EMT) and oxidative stress play an important role in peritoneal fibrosis, which could be regulated by the nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. This study aimed to investigate whether empagliflozin could inhibit HG-induced EMT and oxidative stress via activating the Nrf2/HO-1 signaling pathway. We used HG-based peritoneal dialysis (PD) solution in rats and HG in human peritoneal mesothelial cells (HPMCs) to induce EMT in vivo and in vitro respectively. The peritoneal structure and function were evaluated by hematoxylin and eosin, Masson's trichrome staining, and the peritoneal equilibrium test. Oxidative stress was measured by assay kits. EMT was analyzed using immunohistochemistry and western blot. The PD rats showed decreased ultrafiltration capacity and increased levels of oxidative stress. Histopathological analysis revealed markedly peritoneal thickening, excessive collagen deposition, increased expression of α-SMA, Collagen-I, and Fibronectin, and decreased expression of E‑cadherin. Empagliflozin significantly ameliorated the aforementioned changes. The protein expression levels of nuclear Nrf2 (N-Nrf2) and HO-1 increased in PD rats, which were further promoted by treatment with empagliflozin. In in vitro experiments, the EMT of HPMCs was induced with 60 mM glucose for 24 h and inhibited by empagliflozin. Empagliflozin suppressed oxidative stress and promoted the protein expression of N-Nrf2 and HO-1 in HG‑stimulated HPMCs, which was reversed by the Nrf2 inhibitor. In conclusion, empagliflozin exerted a protective effect against HG-induced EMT and suppressed oxidative stress in PMCs by activating the Nrf2/HO-1 signaling pathway.

Molecular Mechanisms Linking Empagliflozin to Renal Protection in the LLC-PK1 Model of Diabetic Nephropathy

Aims: Chronic diabetes complications, including diabetic nephropathy (DN), frequently result in end-stage renal failure. This study investigated empagliflozin (SGLT2i) effects on collagen synthesis, oxidative stress, cell survival, and protein expression in an LLC-PK1 model of DN. Methods: Combinations of high glucose (HG) and increasing empagliflozin concentrations (100 nM and 500 nM), as well as combinations of HG, H2O2, and empagliflozin, were used for cell culture treatment. The cell viability, glutathione (tGSH), ECM expression, and TGF-β1 concentration were measured. In addition, the protein expression of Akt, pAkt, GSK3, pGSK3, pSTAT3, and SMAD7 was determined. Results: The addition of both concentrations of empagliflozin to cells previously exposed to glucose and oxidative stress generally improved cell viability and increased GSH levels (p < 0.001, p < 0.05). In HG30/H2O2/Empa500-treated cells, significant increase in pSTAT3, pGSK3β, GSK3β, SMAD7, and pAKT levels (p < 0.001, p < 0.001, p < 0.05) was observed except for AKT. Lower drug concentrations did not affect the protein expression levels. Furthermore, empagliflozin treatment (100 nM and 500 nM) of HG30/H2O2-injured cells led to a decrease in TGF-β1 levels (p < 0.001). In cells exposed to oxidative stress and hyperglycemia, collagen production remained unchanged. Conclusion: Renoprotective effects of empagliflozin, in this LLC-PK1 cell model of DN, are mediated via activation of the Akt/GSK-3 signalling pathway, thus reducing oxidative stress-induced damage, as well as enhanced SMAD7 expression leading to downregulation of TGF-β1, one of the key mediators of inflammation and fibrosis.

Sodium-Glucose Cotransporter-2 Inhibitors Could Help Delay Renal Impairment in Patients with Type 2 Diabetes: A Real-World Clinical Setting

This study compared the renoprotective effects of sodium−glucose cotransporter-2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP-4) inhibitors in patients with type 2 diabetes mellitus (T2DM). We performed a retrospective cohort study using electronic medical records of patients with T2DM. The primary outcome was the first occurrence of an estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m2 after the index date. We analyzed changes in repeatedly measured laboratory data, such as eGFR and serum uric acid (SUA). We included 2396 patients (1198 patients in each group) in the present study. The rate of renal events was significantly lower in the SGLT2 inhibitors group than that in the DPP-4 inhibitors group (hazard ratio, 0.46; 95% CI, 0.29 to 0.72; p = 0.0007). The annual mean change in the eGFR was significantly smaller in the SGLT2 inhibitors group than that in the DPP-4 inhibitors group, with a between-group difference of 0.86 ± 0.18 mL/min/1.73 m2 per year (95% CI, 0.49 to 1.23; p < 0.0001). Moreover, the mean change in SUA was lower in the SGLT2 inhibitors group. Considering the lower incidence of renal impairment, the slower decline in eGFR, and reduced SUA, SGLT2 inhibitors could help delay renal impairment in patients with T2DM.

Cardiovascular complications of diabetes

INTRODUCTION

Type 2 diabetes mellitus (T2DM) is the ninth leading cause of mortality globally, and the prevalence continues to rise. Among individuals with T2DM, over two-thirds of deaths are caused by the cardiovascular complications of diabetes. These complications include atherosclerosis, coronary artery disease, nephropathy, stroke, thromboembolism, peripheral vascular disease. They have been long studied, and there are several theories as to the pathophysiology of how diabetes leads to these complications. The least understood mechanism is the pathophysiology linking diabetes to heart failure.

AREAS COVERED

This review focuses on the mechanisms of how T2DM leads to the aforementioned complications, particularly highlighting the development of heart failure. An extensive literature review of novel therapeutic options targeting the cardiovascular effects of T2DM was completed and summarized in this review.

EXPERT OPINION

This review finds that most studies to date have focused on the atherosclerotic vascular complications of diabetes. The pathophysiology between T2DM and heart failure is even less understood. Currently therapies that aim to decrease the risk of heart failure in diabetes are sparse. More research is required in order to better understand the changes at a cellular level and subsequently help providers to choose therapeutics that better target cardiovascular complications.

Sodium-glucose co-transporter 2 inhibitors and hematopoiesis

Many patients with diabetes mellitus, especially those with chronic kidney disorders, have some degree of anemia due to a spectrum of causes and underlying pathophysiologic pathways. As such, enhancement in erythropoiesis is important in these patients. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a relatively new class of antidiabetic drugs with confirmed protective effects in kidney and cardiovascular tissues. Recent evidence suggests that these drugs may provide additional benefits in enhancing hematopoietic processes in diabetic patients. Though the exact mediating pathways have not been fully elucidated, cellular mechanisms are likely involved. In the current study, we present the potential pathways by which SGLT2i may modulate hematopoiesis and stimulate erythropoiesis.

Crosstalk between kidney and liver in non-alcoholic fatty liver disease: mechanisms and therapeutic approaches

Liver and kidney are vital organs that maintain homeostasis and injury to either of them triggers pathogenic pathways affecting the other. For example, non-alcoholic fatty liver disease (NAFLD) promotes the progression of chronic kidney disease (CKD), vice versa acute kidney injury (AKI) endorses the induction and progression of liver dysfunction. Progress in clinical and basic research suggest a role of excessive fructose intake, insulin resistance, inflammatory cytokines production, activation of the renin-angiotensin system, redox imbalance, and their impact on epigenetic regulation of gene expression in this context. Recent developments in experimental and clinical research have identified several biochemical and molecular pathways for AKI-liver interaction, including altered liver enzymes profile, metabolic acidosis, oxidative stress, activation of inflammatory and regulated cell death pathways. This review focuses on the current preclinical and clinical findings on kidney-liver crosstalk in NAFLD-CKD and AKI-liver dysfunction settings and highlights potential molecular mechanisms and therapeutic targets.

TMBIM6 promotes diabetic tubular epithelial cell survival and albumin endocytosis by inhibiting the endoplasmic reticulum stress sensor, IRE1α

AIM

Reduced albumin reabsorption in proximal tubular epithelial cells (PTECs), resulting from decreased megalin plasma membrane (PM) localization due to prolonged endoplasmic reticulum (ER) stress, potentially contributes to albuminuria in early diabetic kidney disease (DKD). To examine this possibility, we investigated the cytoprotective effect of TMBIM6 in promoting diabetic PTEC survival and albumin endocytosis by attenuating ER stress with an IRE1α inhibitor, KIRA6.

METHODS AND RESULTS

Renal TMBIM6 distribution and expression were determined by immunohistochemistry, western blotting, and qPCR, whereas tubular injury was evaluated in db/db mice. High-glucose (HG)-treated HK-2 cells were either treated with KIRA6 or transduced with a lentiviral vector for TMBIM6 overexpression. ER stress was measured by western blotting and ER-Tracker Red staining, whereas apoptosis was determined by performing TUNEL assays. Megalin expression was measured by immunofluorescence, and albumin endocytosis was evaluated after incubating cells with FITC-labeled albumin. Tubular injury and TMBIM6 downregulation occurred in db/db mouse renal cortical tissues. Both KIRA6 treatment and TMBIM6 overexpression inhibited ER stress by decreasing the levels of phosphorylated IRE1α, XBP1s, GRP78, and CHOP, and stabilizing ER expansion in HG-treated HK-2 cells. TUNEL assays performed with KIRA6-treated or TMBIM6-overexpressing cells showed a significant decrease in apoptosis, consistent with the significant downregulation of BAX and upregulation of BCL-2, as measured by immunoblotting. Both KIRA6 and TMBIM6 overexpression promoted megalin PM localization and restored albumin endocytosis in HG-treated HK-2 cells.

CONCLUSION

TMBIM6 promoted diabetic PTEC survival and albumin endocytosis by negatively regulating the IRE1α branch of ER stress.

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

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

Modulation of Reactive Oxygen Species Homeostasis as a Pleiotropic Effect of Commonly Used Drugs

Age-associated diseases represent a growing burden for global health systems in our aging society. Consequently, we urgently need innovative strategies to counteract these pathological disturbances. Overwhelming generation of reactive oxygen species (ROS) is associated with age-related damage, leading to cellular dysfunction and, ultimately, diseases. However, low-dose ROS act as crucial signaling molecules and inducers of a vaccination-like response to boost antioxidant defense mechanisms, known as mitohormesis. Consequently, modulation of ROS homeostasis by nutrition, exercise, or pharmacological interventions is critical in aging. Numerous nutrients and approved drugs exhibit pleiotropic effects on ROS homeostasis. In the current review, we provide an overview of drugs affecting ROS generation and ROS detoxification and evaluate the potential of these effects to counteract the development and progression of age-related diseases. In case of inflammation-related dysfunctions, cardiovascular- and neurodegenerative diseases, it might be essential to strengthen antioxidant defense mechanisms in advance by low ROS level rises to boost the individual ROS defense mechanisms. In contrast, induction of overwhelming ROS production might be helpful to fight pathogens and kill cancer cells. While we outline the potential of ROS manipulation to counteract age-related dysfunction and diseases, we also raise the question about the proper intervention time and dosage.

Oxidative stress in the pathophysiology of type 2 diabetes and related complications: Current therapeutics strategies and future perspectives

Type 2 diabetes (T2DM) is a persistent metabolic disorder rising rapidly worldwide. It is characterized by pancreatic insulin resistance and β-cell dysfunction. Hyperglycemia induced reactive oxygen species (ROS) production and oxidative stress are correlated with the pathogenesis and progression of this metabolic disease. To counteract the harmful effects of ROS, endogenous antioxidants of the body or exogenous antioxidants neutralise it and maintain bodily homeostasis. Under hyperglycemic conditions, the imbalance between the cellular antioxidant system and ROS production results in oxidative stress, which subsequently results in the development of diabetes. These ROS are produced in the endoplasmic reticulum, phagocytic cells and peroxisomes, with the mitochondrial electron transport chain (ETC) playing a pivotal role. The exacerbated ROS production can directly cause structural and functional modifications in proteins, lipids and nucleic acids. It also modulates several intracellular signaling pathways that lead to insulin resistance and impairment of β-cell function. In addition, the hyperglycemia-induced ROS production contributes to micro- and macro-vascular diabetic complications. Various in-vivo and in-vitro studies have demonstrated the anti-oxidative effects of natural products and their derived bioactive compounds. However, there is conflicting clinical evidence on the beneficial effects of these antioxidant therapies in diabetes prevention. This review article focused on the multifaceted role of oxidative stress caused by ROS overproduction in diabetes and related complications and possible antioxidative therapeutic strategies targeting ROS in this disease.

Characteristics and molecular mechanisms through which SGLT2 inhibitors improve metabolic diseases: A mechanism review

Metabolic diseases, such as diabetes, gout and hyperlipidemia are global health challenges. Among them, diabetes has been extensively investigated. Type 2 diabetes mellitus (T2DM), which is characterized by hyperglycemia, is a complex metabolic disease that is associated with various metabolic disorders. The newly developed oral hypoglycemic agent, sodium-glucose cotransporter 2 (SGLT2) inhibitor, has been associated with glucose-lowering effects and it affects metabolism in various ways. However, the potential mechanisms of SGLT2 inhibitors in metabolic diseases have not fully reviewed. Many of the effects beyond glycemic control must be considered off-target effects. Therefore, we reviewed the effects of SGLT2 inhibition on metabolic diseases such as obesity, hypertension, hyperlipidemia, hyperuricemia, fatty liver disease, insulin resistance, osteoporosis and fractures. Moreover, we elucidated their molecular mechanisms to provide a theoretical basis for metabolic disease treatment.

Evaluating the effects of sodium glucose co-transporter -2 inhibitors from a renin-angiotensin-aldosterone system perspective in patients infected with COVID-19: contextualizing findings from the dapagliflozin in respiratory failure in patients with COVID-19 study

Numerous studies demonstrate parallels between CVD, type 2 diabetes mellitus (T2DM) and COVID-19 pathology, which accentuate pre-existing complications in patients infected with COVID-19 and potentially exacerbate the infection course. Antidiabetic drugs such as sodium-glucose transporter-2 (SGLT-2) inhibitors have garnered substantial attention recently due to their efficacy in reducing the severity of cardiorenal disease. The effect of SGLT-2 inhibitors in patients with COVID-19 remains unclear particularly since SGLT-2 inhibitors contribute to altering the RAAS cascade activity, which includes ACE-2, the major cell entry receptor for SARS-CoV2. A study, DARE-19, was carried out to unveil the effects of SGLT-2 inhibitor treatment on comorbid disease complications and concomitant COVID-19 outcomes and demonstrated no statistical significance. However, the need for further studies is essential to provide conclusive clinical findings.

Connexin 43: A Target for the Treatment of Inflammation in Secondary Complications of the Kidney and Eye in Diabetes

Of increasing prevalence, diabetes is characterised by elevated blood glucose and chronic inflammation that precedes the onset of multiple secondary complications, including those of the kidney and the eye. As the leading cause of end stage renal disease and blindness in the working population, more than ever is there a demand to develop clinical interventions which can both delay and prevent disease progression. Connexins are membrane bound proteins that can form pores (hemichannels) in the cell membrane. Gated by cellular stress and injury, they open under pathophysiological conditions and in doing so release 'danger signals' including adenosine triphosphate into the extracellular environment. Linked to sterile inflammation via activation of the nod-like receptor protein 3 inflammasome, targeting aberrant hemichannel activity and the release of these danger signals has met with favourable outcomes in multiple models of disease, including secondary complications of diabetes. In this review, we provide a comprehensive update on those studies which document a role for aberrant connexin hemichannel activity in the pathogenesis of both diabetic eye and kidney disease, ahead of evaluating the efficacy of blocking connexin-43 specific hemichannels in these target tissues on tissue health and function.

Impact of untreated diabetes and COVID-19-related diabetes on severe COVID-19

Diabetes is a common comorbidity in patients with coronavirus disease (COVID-19) and contributes significantly to COVID-19 severity. We aimed to investigate the association between diabetic status and severe COVID-19. This prospective study included all COVID-19 patients admitted to our hospital, who were divided into four groups according to their diabetic status: no diabetes, treated diabetes, untreated diabetes, and COVID-19-related diabetes. Severe COVID-19 was defined as a condition that required the use of a ventilator. Of the 114 patients included in this study, 26 had severe COVID-19. The adjusted odds ratio (OR; 95% confidence interval [CI]) for severe COVID-19 was significantly higher in the treated diabetes, untreated diabetes, and COVID-19-related diabetes groups than in the no diabetes group (OR: 5.9, 95% CI [1.2–27.9]; OR 12.6, 95% CI [1.8–86.4]; and OR: 9.3, 95% [1.1–81.4], respectively). Findings from this study showed that the risk of severe COVID-19 was increased in treated diabetes, untreated diabetes, and COVID-19-related diabetes compared to no diabetes. Furthermore, the OR for severe COVID-19 was greater in untreated diabetes and COVID-19-related diabetes than in treated diabetes.

Metabolic Dysfunction in the Regulation of the NLRP3 Inflammasome Activation: A Potential Target for Diabetic Nephropathy

Metabolic dysfunction plays a key role in the development of diabetic nephropathy (DN). However, the exact effects and mechanisms are still unclear. The pyrin domain-containing protein 3 (NLRP3) inflammasome, a member of the nod-like receptor family, is considered a crucial inflammatory regulator and plays important roles in the progress of DN. A growing body of evidence suggests that high glucose, high fat, or other metabolite disorders can abnormally activate the NLRP3 inflammasome. Thus, in this review, we discuss the potential function of abnormal metabolites such as saturated fatty acids (SFAs), cholesterol crystals, uric acid (UA), and homocysteine in the NLRP3 inflammasome activation and explain the potential function of metabolic dysfunction regulation of NLRP3 activation in the progress of DN via regulation of inflammatory response and renal interstitial fibrosis (RIF). In addition, the potential mechanisms of metabolism-related drugs, such as metformin and sodium glucose cotransporter (SGLT2) inhibitors, which have served as the suppressors of the NLRP3 inflammasomes, in DN, are also discussed. A better understanding of NLRP3 inflammasome activation in abnormal metabolic microenvironment may provide new insights for the prevention and treatment of DN.

The molecular link between oxidative stress, insulin resistance, and type 2 diabetes: A target for new therapies against cardiovascular diseases

Type 2 Diabetes Mellitus (T2D) is a chronic disease with a pandemic incidence whose pathogenesis has not yet been clarified. Raising evidence highlighted the role of oxidative stress in inducing insulin resistance, pancreatic beta-cell dysfunction, and leading to cardiovascular disease (CVD). Therefore, understanding the link between oxidative stress, T2D and CVD may help to further understand the pathological processes beyond this association, to personalize the algorithm of the cure, and to find new therapeutic targets. Here, we discussed the role of oxidative stress and the decrease of antioxidant defenses in the pathogenesis of T2D. Furthermore, some aspects of hypoglycemic therapies and their potential role as antioxidant agents were examined, which might be pivotal in preventing CVD in T2D patients.

Inflammation and Oxidative Stress in Chronic Kidney Disease and Dialysis Patients

Significance: Chronic kidney disease (CKD) can be regarded as a burden of lifestyle disease that shares common underpinning features and risk factors with the aging process; it is a complex constituted by several adverse components, including chronic inflammation, oxidative stress, early vascular aging, and cellular senescence. Recent Advances: A systemic approach to tackle CKD, based on mitigating the associated inflammatory, cell stress, and damage processes, has the potential to attenuate the effects of CKD, but it also preempts the development and progression of associated morbidities. In effect, this will enhance health span and compress the period of morbidity. Pharmacological, nutritional, and potentially lifestyle-based interventions are promising therapeutic avenues to achieve such a goal. Critical Issues: In the present review, currents concepts of inflammation and oxidative damage as key patho-mechanisms in CKD are addressed. In particular, potential beneficial but also adverse effects of different systemic interventions in patients with CKD are discussed. Future Directions: Senotherapeutics, the nuclear factor erythroid 2-related factor 2-kelch-like ECH-associated protein 1 (NRF2-KEAP1) signaling pathway, the endocrine klotho axis, inhibitors of the sodium-glucose cotransporter 2 (SGLT2), and live bio-therapeutics have the potential to reduce the burden of CKD and improve quality of life, as well as morbidity and mortality, in this fragile high-risk patient group. Antioxid. Redox Signal. 35, 1426-1448.

Mitophagy in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the most common cause of end-stage kidney disease worldwide and is the main microvascular complication of diabetes. The increasing prevalence of diabetes has increased the need for effective treatment of DKD and identification of new therapeutic targets for better clinical management. Mitophagy is a highly conserved process that selectively removes damaged or unnecessary mitochondria via the autophagic machinery. Given the important role of mitophagy in the increased risk of DKD, especially with the recent surge in COVID-19-associated diabetic complications, in this review, we provide compelling evidence for maintaining homeostasis in the glomeruli and tubules and its underlying mechanisms, and offer new insights into potential therapeutic approaches for treatment of DKD.

Impact of licochalcone A on the progression of diabetic nephropathy in type 2 diabetes mellitus of C57BL/6 mice

Diabetic nephropathy (DN) is the most common chronic microvascular complication of diabetes. Therefore, it is of great significance to effectively prevent and treat DN. Licochalcone A (LicA) is a flavonoid found in licorice; previous studies have shown that LicA can reduce blood glucose, blood lipids and improve insulin resistance. There has been no research on whether LicA can prevent and treat DN. In this study, an animal model of type 2 diabetes mellitus (T2DM) mice induced by high fat diet/streptozotocin was established, and the intervention of LicA was applied to investigate the protective effect of LicA on the kidneys of DN mice. After 4 weeks of intervention, LicA could effectively reduce blood glucose and alleviate the phenomenon of weight loss in mice. Meanwhile, the levels of MDA, SOD and GSH-Px in the kidney tissue and serum were recovered to different degrees. Besides, LicA decreased the levels of TC, TG and LDL-C in the kidney tissue and increased the level of HDL-C in the kidney tissue. The 24 h urinary protein, blood urea nitrogen (BUN) and serum creatinine (SCr) levels of mice in the treatment group of LicA were significantly lower than those in the model group. Furthermore, HE staining, PAS staining and Masson staining indicated that LicA improved the pathological damage of kidneys, and the kidney index of mice also decreased. Western blotting results indicated that LicA could significantly down-regulate the protein expression of AGEs/RAGE, TGF-β1, HIF-1α and GLUT1, and up-regulate the protein expression of Nrf2. It provides a theoretical basis for the further development and utilization of LicA.

Sodium-Glucose Co-transporter-2 Inhibitor-Induced Pruritus: Itching for Answers

Sodium-glucose co-transporter 2 inhibitors (SGLT2-I) have revolutionized the treatment of type 2 diabetes mellitus during the last decade. It has not only proven to be very effective for glycemic control but also has adjunctive effects in the management of heart failure, hypertension, and diabetic nephropathy, and even contributes to weight loss. Another benefit is the apparent lack of major side effects, particularly hypoglycemia, apart from euglycemic diabetic ketoacidosis. The most well-known side effects are genital mycotic infections and urinary tract infections (UTI). Although pruritus is less well known, we highlight in this case study this side effect as notable albeit uncommon so as to sensitize clinicians to its possibility.

Diabetic proximal tubulopathy: Can we mimic the disease for in vitro screening of SGLT inhibitors?

Diabetic kidney disease (DKD) is the foremost cause of renal failure. While the glomeruli are severely affected in the course of the disease, the main determinant for disease progression is the tubulointerstitial compartment. DKD does not develop in the absence of hyperglycemia. Since the proximal tubule is the major player in glucose reabsorption, it has been widely studied as a therapeutic target for the development of new therapies. Currently, there are several proximal tubule cell lines available, being the human kidney-2 (HK-2) and human kidney clone-8 (HKC-8) cell lines the ones widely used for studying mechanisms of DKD. Studies in these models have pushed forward the understanding on how DKD unravels, however, these cell culture models possess limitations that hamper research, including lack of transporters and dedifferentiation. The sodium-glucose cotransporters (SGLT) are identified as key players in glucose reabsorption and pharmacological inhibitors have shown to be beneficial for the long-term clinical outcome in DKD. However, their mechanism of action has, as of yet, not been fully elucidated. To comprehend the protective effects of SGLT inhibitors, it is essential to understand the complete functional, structural, and molecular features of the disease, which until now have been difficult to recapitulate. This review addresses the molecular events of diabetic proximal tubulopathy. In addition, we evaluate the protective role of SGLT inhibitors in cardiovascular and renal outcomes, and provide an overview of various in vitro models mimicking diabetic proximal tubulopathy used so far. Finally, new insights on advanced in vitro systems to surpass past limitations are postulated.

Reno-protective potential of sodium glucose cotransporter-2 (SGLT2) inhibitors: Summary evidence from clinical and real-world data

Type 2 diabetes mellitus is an independent risk factor for renal impairment, developing in due course to end-stage kidney disease (ESKD). Such progressive renal damage is related to an increased predisposition to cardiovascular events and mortality. Even with intensive glycemic control and use of nephro-protective renin angiotensin system (RAS) blockers, rise in the worldwide prevalence of diabetic kidney disease remains tenacious. Identifying drugs with potential to halt progressive renal damage is the pressing priority at present. Sodium glucose cotransporter 2 (SGLT2) inhibitors, by virtue of their glucose-lowering and additional pleotropic effects, such as weight reduction, blood pressure lowering, anti-inflammatory, anti-fibrotic effects etc. are postulated to affect systemic and intrarenal hemodynamic mechanisms in a favorable manner which ultimately contribute to beneficial processes in the kidney. The promising reno-protective efficacy of these drugs is further highlighted by a reduction in development/progression of albuminuria and stabilization of renal function associated with their use. In particular, recent cardiovascular and kidney disease focused outcome trials have effectively demonstrated reduced rates of ESKD and other hard renal end-points, including doubling of serum creatinine, renal transplantation, death due to renal causes etc. with SGLT2 inhibitors. In this review, we dig further deep into the proposed reno-protective benefit furnished by this class of drugs by summarizing the evidence generated from clinical trials and large real-world studies. Current guideline recommendations and probability of reno-protection being influenced by factors, such as diabetic status, baseline renal function, RAS blockade is also explored to discuss their intended use in clinical settings.

Direct Blood Pressure-Independent Anti-Fibrotic Effects by the Selective Nonsteroidal Mineralocorticoid Receptor Antagonist Finerenone in Progressive Models of Kidney Fibrosis

INTRODUCTION

The nonsteroidal mineralocorticoid receptor (MR) antagonist finerenone and sodium-glucose cotransporter-2 (SGLT2) inhibitors have demonstrated clinical benefits in chronic kidney disease patients with type 2 diabetes. Precise molecular mechanisms responsible for these benefits are incompletely understood. Here, we investigated potential direct anti-fibrotic effects and mechanisms of nonsteroidal MR antagonism by finerenone or SGLT2 inhibition by empagliflozin in 2 relevant mouse kidney fibrosis models: unilateral ureter obstruction and sub-chronic ischemia reperfusion injury.

METHODS

Kidney fibrosis was induced in mice via unilateral ureteral obstruction or ischemia. In a series of experiments, mice were treated orally with the MR antagonist finerenone (3 or 10 mg/kg), the SGLT2 inhibitor empagliflozin (10 or 30 mg/kg), or in a direct comparison of both drugs. Interstitial myofibroblast accumulation was quantified via alpha-smooth muscle actin and interstitial collagen deposition via Sirius Red/Fast Green staining in both models. Secondary analyses included the assessment of inflammatory cells, kidney mRNA expression of fibrotic markers as well as functional parameters (serum creatinine and albuminuria) in the ischemic model. Blood pressure was measured via telemetry in healthy conscious compound-treated animals.

RESULTS

Finerenone dose-dependently decreased pathological myofibroblast accumulation and collagen deposition with no effects on systemic blood pressure and inflammatory markers in the tested dose range. Reduced kidney fibrosis was paralleled by reduced kidney plasminogen activator inhibitor-1 (PAI-1) and naked cuticle 2 (NKD2) expression in finerenone-treated mice. In contrast, treatment with empagliflozin strongly increased urinary glucose excretion in both models and reduced ischemia-induced albuminuria but had no effects on kidney myofibroblasts or collagen deposition.

DISCUSSION/CONCLUSION

Finerenone has direct anti-fibrotic properties resulting in reduced myofibroblast and collagen deposition accompanied by a reduction in renal PAI-1 and NKD2 expression in mouse models of progressive kidney fibrosis at blood pressure-independent dosages.

Dapagliflozin ameliorates pancreatic injury and activates kidney autophagy by modulating the AMPK/mTOR signaling pathway in obese rats

Chronic consumption of a high-fat diet induces obesity and impairs the ultra-structure of organs and tissues. We examined the effect of sodium-glucose cotransporter 2 (SGLT2) inhibitor-dapagliflozin on renal and pancreatic injuries in obese condition. Rats were fed a high-fat diet for 16 weeks to induce obesity. After that, dapagliflozin or vildagliptin, 1.0 or 3.0 mg/kg/day, respectively, was administered by oral gavage for 4 weeks. The effects of dapagliflozin on insulin resistance, kidney autophagy, pancreatic oxidative stress, endoplasmic reticulum (ER) stress, inflammation, and apoptosis in high-fat diet-induced obese rats were elucidated. High-fat-diet fed rats demonstrated metabolic abnormalities including increased body weight, visceral fat weight, plasma insulin, plasma cholesterol, homeostasis model assessment (HOMA) index, and TAUCg, indicating the obese-insulin resistant and glucose intolerance conditions. Also, high-fat-diet fed rats exhibited significant pancreatic injury accompanied by decreased kidney autophagy. Dapagliflozin or vildagliptin treatment for 4 weeks ameliorated pancreatic oxidative stress, ER stress, inflammation, and apoptosis and restored kidney autophagy in obese rats. Moreover, the morphology changes of the pancreas and kidney were improved in the treated groups. Interestingly, dapagliflozin showed higher efficacy than vildagliptin in improving body weight, visceral fat weight, plasma cholesterol level, and pancreatic oxidative stress in our model. Taken together, the present study demonstrated that the therapeutic effects of dapagliflozin attenuated pancreatic injury, pancreatic oxidative stress, ER stress, inflammation, apoptosis, and exerted renoprotective effects by restoring autophagic signaling in obese rats.

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

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

Emergence of SGLT2 Inhibitors as Powerful Antioxidants in Human Diseases

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new class of oral glucose-lowering agents. Apart from their glucose-lowering effects, large clinical trials assessing certain SGLT2 inhibitors have revealed cardiac and renal protective effects in non-diabetic patients. These excellent outcomes motivated scientists and clinical professionals to revisit their underlying mechanisms. In addition to the heart and kidney, redox homeostasis is crucial in several human diseases, including liver diseases, neural disorders, and cancers, with accumulating preclinical studies demonstrating the therapeutic benefits of SGLT2 inhibitors. In the present review, we aimed to update recent advances in the antioxidant roles of SGLT2 inhibitors in common but debilitating human diseases. We anticipate that this review will guide new research directions and novel therapeutic strategies for diabetes, cardiovascular diseases, nephropathies, liver diseases, neural disorders, and cancers in the era of SGLT2 inhibitors.

Management of diabetes in elderly patients during the COVID-19 pandemic: current and future perspectives

Introduction: The COVID-19 pandemic has affected the entire population with the most deleterious effects in elders. Elders, especially those with diabetes, are at the highest risk of COVID-19 related adverse outcomes and mortality. This is usually linked to the comorbidities that accumulate with age, diabetes-related chronic inflammation, and the pandemic's psychosocial effects.Areas covered: We present some approaches to manage these complicated elderly patients with diabetes during the COVID-19 pandemic. In the inpatient setting, we suggest similar (pre-pandemic) glycemic targets and emphasize the importance of using IV insulin and possible use of continuous glucose monitoring to reduce exposure and PPE utilization. Outside the hospital, we recommend optimal glycemic control within the limits imposed by considerations of safety. We also describe the advantages and challenges of using various technological platforms in clinical care.Expert opinion: The COVID-19 pandemic has lifted the veil off serious deficiencies in the infrastructures for care at both the individual level and the population level and also highlighted some of the strengths, all of which affect individuals with diabetes and COVID-19. We anticipate that things will not return to 'normal' after the COVID-19 pandemic has run its course, but rather they will be superseded by 'New Normal.'

Could Dapagliflozin Attenuate COVID-19 Progression in High-Risk Patients With or Without Diabetes? Behind DARE-19 Concept

ABSTRACT

Epidemiological studies indicate that diabetes is the second most common comorbidity in COVID-19 (coronavirus disease 2019). Dapagliflozin, a sodium-glucose co-transporter 2 inhibitor, exerts direct cardioprotective and nephroprotective effects. DARE-19 (Dapagliflozin in Respiratory Failure in Patients With COVID-19), an ongoing clinical trial, is designed to investigate the impact of dapagliflozin on COVID-19 progression. This article discusses the potential favorable impact of dapagliflozin on COVID-19 and its complications.

Advances in understanding the innate immune-associated diabetic kidney disease

Millions of human deaths occur annually due to chronic kidney disease, caused by diabetic kidney disease (DKD). Despite having effective drugs controlling the hyperglycemia and high blood pressure, the incidence of DKD is increasing, which indicates the need for the development of novel therapies to control DKD. In this article, we discussed the recent advancements in the basic innate immune mechanisms in renal tissues triggered under the diabetes environment, leading to the pathogenesis and progression of DKD. We also summarized the currently available innate immune molecules-targeting therapies tested against DKD in clinical and preclinical settings, and highlighted additional drug targets that could potentially be employed for the treatment of DKD. The improved understanding of the disease pathogenesis may open avenues for the development of novel therapies to rein in DKD, which consequently, can reduce morbidity and mortality in humans in the future.

Sodium-Glucose Co-transporter-2 Inhibitors and Nephroprotection in Diabetic Patients: More Than a Challenge

Diabetic nephropathy is the most common cause of end-stage renal disease worldwide. Control of blood glucose and blood pressure (BP) reduces the risk of developing this complication, but once diabetic nephropathy is established, it is then only possible to slow its progression. Sodium-glucose cotransporter-2 inhibitors (SGLT2is) are a novel class of oral hypoglycemic agents that increase urinary glucose excretion by suppressing glucose reabsorption at the renal proximal tubule. SGLT2is lower glycated hemoglobin (HbA1c) without increasing the risk of hypoglycemia, induce weight loss and improve various metabolic parameters including BP, lipid profile, albuminuria and uric acid. Several clinical trials have shown that SGLT2is (empagliflozin, dapagliflozin canagliflozin, and ertugliflozin) improve cardiovascular and renal outcomes and mortality in patients with type 2 diabetes. Effects of SGLT2is on the kidney can be explained by multiple pathways. SGLT2is may improve renal oxygenation and intra-renal inflammation thereby slowing the progression of kidney function decline. Additionally, SGLT2is are associated with a reduction in glomerular hyperfiltration, an effect which is mediated by the increase in natriuresis, the re-activation of tubule-glomerular feedback and independent of glycemic control. In this review, we will focus on renal results of major cardiovascular and renal outcome trials and we will describe direct and indirect mechanisms through which SGLT2is confer renal protection.

Cardiologist's approach to the diabetic patient: No further delay for a paradigm shift

Type 2 diabetes mellitus (DM) is constantly increasing worldwide and its most critical determinant of morbidity and mortality is still represented by cardiovascular (CV) complications. For years, cardiologists' approach to diabetic patients has been focused on risk factors optimization, with positive results. However, the management of DM per se was never truly considered in order to obtain prevention from major CV events, because medications used for glycemic control were not expected to gain CV benefit. Early trials concerning intensive versus conventional glycemia control did not prove useful in reducing the number of CV events. The introduction of new molecules led to a game change in DM treatment, as some new glucose-lowering drugs (GLDs), such as sodium-glucose linked transporter-2 inhibitors (SGLT-2i) and glucagon-like peptide 1 receptor agonists (GLP-1 RA), showed not only to be safe but also to ensure CV benefit. A combination of anti-atherogenic effects and hemodynamic improvements are likely explanations of the observed reduction of CV events and mortality. These evidence opened a completely new era in the field of GLDs and of DM treatment. Nonetheless, the presence of residual cardiovascular risk despite optimal medical therapy remains an issue and an aggressive strategy against multiple risk factors is suggested. A paradigm shift toward a new approach to DM management should be made with no further delay with the use of medications that may prevent CV events in an integrated strategy of CV risk reduction.

Inhibition of Lysine 63 Ubiquitination Prevents the Progression of Renal Fibrosis in Diabetic DBA/2J Mice

Diabetic nephropathy (DN) is the most frequent cause of end-stage renal disease. Tubulointerstitial accumulation of lysine 63 (K63)-ubiquitinated (Ub) proteins is involved in the progression of DN fibrosis and correlates with urinary miR-27b-3p downregulation. We explored the renoprotective effect of an inhibitor of K63-Ub (NSC697923), alone or in combination with the ACE-inhibitor ramipril, in vitro and in vivo. Proximal tubular epithelial cells and diabetic DBA/2J mice were treated with NSC697923 and/or ramipril. K63-Ub protein accumulation along with α-SMA, collagen I and III, FSP-1, vimentin, p16^INK4A expression, SA-α Gal staining, Sirius Red, and PAS staining were measured. Finally, we measured the urinary albumin to creatinine ratio (uACR), and urinary miR-27b-3p expression in mice. NSC697923, both alone and in association with ramipril, in vitro and in vivo inhibited hyperglycemia-induced epithelial to mesenchymal transition by significantly reducing K63-Ub proteins, α-SMA, collagen I, vimentin, FSP-1 expression, and collagen III along with tubulointerstitial and glomerular fibrosis. Treated mice also showed recovery of urinary miR-27b-3p and restored expression of p16^INK4A. Moreover, NSC697923 in combination with ramipril demonstrated a trend in the reduction of uACR. In conclusion, we suggest that selective inhibition of K63-Ub, when combined with the conventional treatment with ACE inhibitors, might represent a novel treatment strategy to prevent the progression of fibrosis and proteinuria in diabetic nephropathy and we propose miR-27b-3p as a biomarker of treatment efficacy.

Empagliflozin Inhibits IL-1β-Mediated Inflammatory Response in Human Proximal Tubular Cells

SGLT2 inhibitor-related nephroprotection is—at least partially—mediated by anti-inflammatory drug effects, as previously demonstrated in diabetic animal and human studies, as well as hyperglycemic cell culture models. We recently presented first evidence for anti-inflammatory potential of empagliflozin (Empa) under normoglycemic conditions in human proximal tubular cells (HPTC) by demonstrating Empa-mediated inhibition of IL-1β-induced MCP-1/CCL2 and ET-1 expression on the mRNA and protein level. We now add corroborating evidence on a genome-wide level by demonstrating that Empa attenuates the expression of several inflammatory response genes in IL-1β-induced (10 ng/mL) normoglycemic HPTCs. Using microarray-hybridization analysis, 19 inflammatory response genes out of >30.000 human genes presented a consistent expression pattern, that is, inhibition of IL-1β (10 ng/mL)-stimulated gene expression by Empa (500 nM), in both HK-2 and RPTEC/TERT1 cells. Pathway enrichment analysis demonstrated statistically significant clustering of annotated pathways (enrichment score 3.64). Our transcriptomic approach reveals novel genes such as CXCL8/IL8, LOX, NOV, PTX3, and SGK1 that might be causally involved in glycemia-independent nephroprotection by SGLT2i.