Dapagliflozin, SGLT2 Inhibitor, Attenuates Renal Ischemia-Reperfusion Injury

Dapagliflozin ameliorates kidney injury following limb ischemia-reperfusion via the AMPK/SIRT1/NLRP3 pathway

Limb ischemia-reperfusion (I/R) results in both localized tissue harm and injury to distant organs, particularly affecting the kidneys and leading to acute kidney injury. This study evaluates the renoprotective effect of dapagliflozin, a drug frequently prescribed for type 2 diabetes management, in relation to kidney injury caused by limb I/R. The extent of kidney injury was detected through serum marker testing in the rat model. Oxidative stress indicators and inflammatory factors were evaluated in rat and cellular models. Histological changes in the kidneys were examined using HE staining and electron microscopy. Cell pyroptosis was quantified using both TUNEL staining and flow cytometry. Cellular mitochondrial function was analyzed with JC-1 staining. AMPK/SIRT1/NLRP3 pathway-related proteins and their mRNAs were assessed via western blotting and RT-qPCR techniques. We showed that dapagliflozin reduced serum CRE, BUN, NGAL and KIM-1 levels and improved renal pathology in rat. Additionally, dapagliflozin significantly raised the concentrations of GSH-Px and SOD, concurrently reduced MDA and ROS levels in vivo and in vitro. It also lowered the levels of IL-6 and TNF-α and reduced cell pyroptosis. Furthermore, it was observed that dapagliflozin elevated AMPK and SIRT1 expressions, while decreasing NLRP3, ASC, GSDMD, IL-1β, and caspase-1 expressions. Notably, these effects of dapagliflozin were diminished in the presence of AMPK siRNA. Taken together, dapagliflozin exhibits a significant protective effect against kidney injury resulting from limb I/R. This protective effect operates through the inhibition of pyroptosis by activating the AMPK/SIRT1/NLRP3 signaling pathway.

Impact of sodium-glucose transport protein-2 (SGLT2) inhibitors on the inflammasome pathway in acute myocardial infarction in type 2 diabetes mellitus: a comprehensive review

Sodium-glucose transport protein-2 (SGLT2) inhibitors, initially developed for glycemic control in type 2 diabetes mellitus (T2DM), have emerged as potential cardioprotective agents, reducing cardiovascular mortality and improving heart failure outcomes. Recent evidence suggests that SGLT2 inhibitors exert anti-inflammatory effects, particularly through modulating the inflammasome pathway. This review explores the role of the inflammasome in acute myocardial infarction (AMI) in T2DM and discusses the mechanisms by which SGLT2 inhibitors influence this pathway. We evaluate current studies on the impact of SGLT2 inhibitors on key inflammatory mediators, particularly the NLRP3 inflammasome, and discuss their potential therapeutic implications for reducing inflammation and myocardial injury in patients with T2DM experiencing AMI. In summary, the key novelties in this review lie in its focused mechanistic approach on the inflammasome pathway, its integration of diabetes and cardiovascular research, and its potential to influence future therapeutic strategies for AMI in T2DM patients. It offers a novel angle by tying together molecular mechanisms of inflammation with clinical implications in a specific patient population that faces high cardiovascular risk.

Oxyresveratrol and/or Dapagliflozin Attenuate Doxorubicin-Induced Nephrotoxicity via Modulation of PPAR-γ/Nrf-2/HO-1, NF-κB/TNF-α/Keap-1, and Bcl-2/Caspase-3/ATG-5 signaling pathways in rats

PURPOSE

Among the most undesirable effects that lead to the restriction of doxorubicin (DOX) use in chemotherapy is kidney damage. This research aimed to assess the possible defenses against DOX-induced nephrotoxicity offered by oxyresveratrol (ORES) and/or dapagliflozin (DAPA).

METHODS

Five groups of eight male Swiss albino rats each were created from a total of sixty-four. One intravenous injection of DOX (10 mg/kg) was given into the tail vein on the fourteenth day of the experiment; in the meantime, ORES (80 mg/kg) and DAPA (10 mg/kg) were given orally 14 days prior to the DOX injection and 2 days following the DOX injection.

RESULTS

In rats given DOX, ORES and/or DAPA both successfully reduced the kidney weight, kidney/bodyweight ratio, and blood levels of creatinine, uric acid, and urea. They also increased final body weight and albumin serum levels. Additionally, lower serum concentrations of TNF-α and IL-6 were noted, along with a lower kidney content of caspase-3. Furthermore, the expression of the Bcl-2 gene was upregulated, as were the Nrf-2, PPAR-γ, and HO-1 proteins, and there was a downregulation of the ATG-5, Keap-1, and NF-κB renal gene expression. These findings support a decrease in oxidative stress and relief of histopathological alterations.

CONCLUSION

The current study's findings suggest that ORES and/or DAPA pretreatment could be a viable therapeutic approach to ameliorate DOX-induced nephrotoxicity.

Sodium-glucose cotransporter 2 inhibitors: a novel approach to prevent the transition from acute kidney injury to chronic kidney disease

PURPOSE OF REVIEW

Acute kidney injury (AKI) often progresses to chronic kidney disease (CKD), yet standardized clinical guidelines for managing this transition remain lacking. Recent studies suggest that sodium-glucose cotransporter 2 inhibitors (SGLT2i) or flozins improve AKI outcomes. Studies on patients living with diabetes post-AKI show flozins reduce mortality, CKD progression, and recurrent AKI, highlighting their potential in mitigating maladaptive kidney repair. We discuss recent preclinical evidence supporting a role of SGLT2i during AKI repair and subsequent CKD.

RECENT FINDINGS

AKI is characterized by endothelial and tubular injury, hypoperfusion, metabolic dysfunction, inflammation, and cell death. SGLT2i restore renal hemodynamics, mitochondrial dysfunction, and reduce oxidative stress, improving recovery following AKI. Additionally, SGLT2i mitigate cell death by counteracting apoptosis and ferroptosis while reducing inflammation through suppression of pro-inflammatory cytokines and inflammasome activation. Beyond AKI, flozins exhibit long-term antifibrotic effects, reducing extracellular matrix deposition even after treatment discontinuation. Preclinical studies demonstrate a sustained protective effect on kidney integrity months after short-term treatment.

SUMMARY

These inhibitors hold promise for broad nephroprotection, with robust biological rationale in maladaptive repair. Further research is needed to optimize their use and establish clinical guidelines for AKI management in both diabetic and nondiabetic populations.

Sodium-glucose cotransporter-2 inhibitors in individuals with ischemia reperfusion injury: A systematic review

Background: The effects of sodium-glucose cotransporter-2 (SGLT-2) inhibitors on ischemia reperfusion injury (IRI) is a novel concept and only limited number of animals studies have yet been investigated. We aimed to perform a systematic review of literature to explore the clinical studies which investigated the effects of SGLT-2 inhibitors on myocardial IRI setting.Methods: We searched MEDLINE, Embase, and Cochrane Library from inception until December 7th, 2023. ClinicalTrials.gov was also explored for ongoing studies. Two authors independently conducted the literature search, examined the studies, and evaluated the eligibility criteria. Any disagreements or uncertainties were resolved by the corresponding author. The search strategy followed the PICO process (Population, Intervention, Comparison, and Outcome) and Emtree was used to select relevant keywords.Results: Of 220 articles identified from the literature research, five articles were included in the study, of which three studies lately were retracted. The remaining studies included 1229 participants, with 209 receiving SGLT-2 inhibitors and 1090 not receiving them. All of the participants were diabetic patients admitted with acute myocardial infarction (AMI), undergoing percutaneous coronary intervention (PCI). The results demonstrated that the use of SGLT-2 inhibitors is associated with lower troponin levels, and higher rates of ST resolution. The results of the studies also showed smaller infarct sizes, lower inflammatory biomarkers and improved left ventricular function at discharge among SGLT-2 inhibitor users.Conclusion: In line with in vivo and ex vivo findings, the results of this systematic review supported benefits of SGLT-2 inhibitors in IRI through reducing infarct size and inflammatory biomarkers. However, further clinical trials are warranted to provide robust evidence.

Combination of dapagliflozin and pioglitazone lacks superiority against monotherapy in streptozotocin-induced nephropathy

Oxidative stress and apoptosis are highly engaged in development of diabetic nephropathy (DN). In monotherapy, dapagliflozin and pioglitazone positively modulate target organ damage even independently of their hypoglycaemic effect. This study evaluated whether a simultaneous PPARγ activation and SGLT cotransporter inhibition offer superior protection against DN-related oxidative and apoptotic processes in a T1DM rat model. Diabetes was induced in Wistar rats using streptozotocin (55 mg/kg, i.p.). The rats received daily chow containing dapagliflozin (10 mg/kg), pioglitazone (12 mg/kg) or their combination. Six weeks after STZ administration, histological and molecular analyses were performed in excised kidneys. STZ-induced DN was demonstrated by the propagation of apoptotic (Bax, p53, Casp3) and oxidative reactions (Gp91phox, MnSOD) and disrupted nitric oxide signalling (eNOS, Hsp90, Cav1). Kidney damage molecule expression (Kim1, Nphs1) revealed a deceleration of kidney damage by pioglitazone and dapagliflozine monotherapies. The monotherapy also reduced apoptosis, oxidative stress, and partially restored NO signalling. The combined therapy ameliorated glomerulosclerosis but in other measured parameters, it reached the effect of the monotherapies except for Hsp90 expression modulation. Both dapagliflozin and pioglitazone exert protective character in kidneys when used in monotherapy. The combined therapy does not exhibit an expected additive effect within modulating oxidative stress, NO signalling or apoptosis.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

SGLT2 inhibition mitigates transition from acute kidney injury to chronic kidney disease by suppressing ferroptosis

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown to be renoprotective in ischemia-reperfusion (I/R) injury, with several proposed mechanisms, though additional mechanisms likely exist. This study investigated the impact of luseogliflozin on kidney fibrosis at 48 h and 1 week post I/R injury in C57BL/6 mice. Luseogliflozin attenuated kidney dysfunction and the acute tubular necrosis score on day 2 post I/R injury, and subsequent fibrosis at 1 week, as determined by Sirius red staining. Metabolomics enrichment analysis of I/R-injured kidneys revealed suppression of the glycolytic system and activation of mitochondrial function under treatment with luseogliflozin. Western blotting showed increased nutrient deprivation signaling with elevated phosphorylated AMP-activated protein kinase and Sirtuin-3 in luseogliflozin-treated kidneys. Luseogliflozin-treated kidneys displayed increased protein levels of carnitine palmitoyl transferase 1α and decreased triglyceride deposition, as determined by oil red O staining, suggesting activated fatty acid oxidation. Luseogliflozin prevented the I/R injury-induced reduction in nuclear factor erythroid 2-related factor 2 activity. Western blotting revealed increased glutathione peroxidase 4 and decreased transferrin receptor protein 1 expression. Immunostaining showed reduced 4-hydroxynonenal and malondialdehyde levels, especially in renal tubules, indicating suppressed ferroptosis. Luseogliflozin may protect the kidney from I/R injury by inhibiting ferroptosis through oxidative stress reduction.

Acute Dapagliflozin Administration Ameliorates Cardiac Surgery-Associated Acute Kidney Injury in a Rabbit Model

BACKGROUND

 Several studies have shown that sodium-glucose cotransporter-2 inhibitors have a renoprotective effect on acute kidney injury (AKI), but their effect on cardiac surgery-associated AKI is unknown.

METHODS AND RESULTS

 AKI was induced in 25 rabbits without diabetes mellitus by cardiopulmonary bypass (CPB) for 2 h and they were divided into 5 groups: sham; dapagliflozin-treated sham; CPB; dapagliflozin-treated CPB; and furosemide-treated CPB (n=5 in each group). Dapagliflozin was administered via the femoral vein before initiating CPB. Kidney tissue and urine and blood samples were collected after the surgical procedure. There were no differences in the hemodynamic variables of each group. Dapagliflozin reduced serum creatinine and blood urea nitrogen concentrations, and increased overall urine output (all P<0.05). Hematoxylin and eosin staining showed that the tubular injury score was improved after dapagliflozin administration (P<0.01). Dapagliflozin administration mitigated reactive oxygen species and kidney injury molecule-1 as assessed by immunohistochemistry (both P<0.0001). Protein expression analysis showed improvement of inflammatory cytokines and apoptosis, and antioxidant enzyme expression was elevated (all P<0.05) through activation of the nuclear factor erythroid 2-related factor 2 pathway (P<0.01) by dapagliflozin.

CONCLUSIONS

 Acute intravenous administration of dapagliflozin protects against CPB-induced AKI. Dapagliflozin may have direct renoprotective effects in renal tubular cells.

EValuating the Effect of periopeRaTIve empaGliflOzin on cardiac surgery associated acute kidney injury: rationale and design of the VERTIGO study

Background

Cardiac surgery-associated acute kidney injury (CSA-AKI) is a serious complication in patients undergoing cardiac surgery with extracorporeal circulation (ECC) that increases postoperative complications and mortality. CSA-AKI develops due to a combination of patient- and surgery-related risk factors that enhance renal ischemia-reperfusion injury. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) such as empagliflozin reduce renal glucose reabsorption, improving tubulo-glomerular feedback, reducing inflammation and decreasing intraglomerular pressure. Preclinical studies have observed that SGLT2i may provide significant protection against renal ischemia-reperfusion injury due to their effects on inadequate mitochondrial function, reactive oxygen species activity or renal peritubular capillary congestion, all hallmarks of CSA-AKI. The VERTIGO (EValuating the Effect of periopeRaTIve empaGliflOzin) trial is a Phase 3, investigator-initiated, randomized, double-blind, placebo-controlled, multicenter study that aims to explore whether empagliflozin can reduce the incidence of adverse renal outcomes in cardiac surgery patients.

Methods

The VERTIGO study (EudraCT: 2021-004938-11) will enroll 608 patients that require elective cardiac surgery with ECC. Patients will be randomly assigned in a 1:1 ratio to receive either empagliflozin 10 mg orally daily or placebo. Study treatment will start 5 days before surgery and will continue during the first 7 days postoperatively. All participants will receive standard care according to local practice guidelines. The primary endpoint of the study will be the proportion of patients that develop major adverse kidney events during the first 90 days after surgery, defined as ≥25% renal function decline, renal replacement therapy initiation or death. Secondary, tertiary and safety endpoints will include rates of AKI during index hospitalization, postoperative complications and observed adverse events.

Conclusions

The VERTIGO trial will describe the efficacy and safety of empagliflozin in preventing CSA-AKI. Patient recruitment is expected to start in May 2024.

The potential anti-arrhythmic effect of SGLT2 inhibitors

Sodium-glucose cotransporter type 2 inhibitors (SGLT2i) were initially recommended as oral anti-diabetic drugs to treat type 2 diabetes (T2D), by inhibiting SGLT2 in proximal tubule and reduce renal reabsorption of sodium and glucose. While many clinical trials demonstrated the tremendous potential of SGLT2i for cardiovascular diseases. 2022 AHA/ACC/HFSA guideline first emphasized that SGLT2i were the only drug class that can cover the entire management of heart failure (HF) from prevention to treatment. Subsequently, the antiarrhythmic properties of SGLT2i have also attracted attention. Although there are currently no prospective studies specifically on the anti-arrhythmic effects of SGLT2i. We provide clues from clinical and fundamental researches to identify its antiarrhythmic effects, reviewing the evidences and mechanism for the SGLT2i antiarrhythmic effects and establishing a novel paradigm involving intracellular sodium, metabolism and autophagy to investigate the potential mechanisms of SGLT2i in mitigating arrhythmias.

Cardiometabolic comorbidities and complications of obesity and chronic kidney disease (CKD)

Obesity and chronic kidney disease are two ongoing progressive clinical pandemics of major public health and clinical care significance. Because of their growing prevalence, chronic indolent course and consequent complications both these conditions place significant burden on the health care delivery system especially in developed countries like the United States. Beyond the chance coexistence of both of these conditions in the same patient based on high prevalence it is now apparent that obesity is associated with and likely has a direct causal role in the onset, progression and severity of chronic kidney disease. The causes and underlying pathophysiology of this are myriad, complicated and multi-faceted. In this review, continuing the theme of this special edition of the journal on " The Cross roads between Endocrinology and Nephrology" we review the epidemiology of obesity related chronic kidney disease (ORCKD), and its various underlying causes and pathophysiology. In addition, we delve into the consequent comorbidities and complications associated with ORCKD with particular emphasis on the cardio metabolic consequences and then review the current body of evidence for available strategies for chronic kidney disease modulation in ORCKD as well as the potential unique role of weight reduction and management strategies in its improvement and risk reduction.

SGLT2 inhibitors: from glucose-lowering to cardiovascular benefits

An increasing number of individuals are at high risk of type 2 diabetes (T2D) and its cardiovascular complications, including heart failure (HF), chronic kidney disease (CKD), and eventually premature death. The sodium-glucose co-transporter-2 (SGLT2) protein sits in the proximal tubule of human nephrons to regulate glucose reabsorption and its inhibition by gliflozins represents the cornerstone of contemporary T2D and HF management. Herein, we aim to provide an updated overview of the pleiotropy of gliflozins, provide mechanistic insights and delineate related cardiovascular (CV) benefits. By discussing contemporary evidence obtained in preclinical models and landmark randomized controlled trials, we move from bench to bedside across the broad spectrum of cardio- and cerebrovascular diseases. With landmark randomized controlled trials confirming a reduction in major adverse CV events (MACE; composite endpoint of CV death, non-fatal myocardial infarction, and non-fatal stroke), SGLT2 inhibitors strongly mitigate the risk for heart failure hospitalization in diabetics and non-diabetics alike while conferring renoprotection in specific patient populations. Along four major pathophysiological axes (i.e. at systemic, vascular, cardiac, and renal levels), we provide insights into the key mechanisms that may underlie their beneficial effects, including gliflozins' role in the modulation of inflammation, oxidative stress, cellular energy metabolism, and housekeeping mechanisms. We also discuss how this drug class controls hyperglycaemia, ketogenesis, natriuresis, and hyperuricaemia, collectively contributing to their pleiotropic effects. Finally, evolving data in the setting of cerebrovascular diseases and arrhythmias are presented and potential implications for future research and clinical practice are comprehensively reviewed.

Larger Degree of Renal Function Decline in Chronic Kidney Disease Is a Favorable Factor for the Attenuation of eGFR Slope Worsening by SGLT2 Inhibitors: A Retrospective Observational Study

INTRODUCTION

Sodium-glucose cotransporter 2 inhibitors (SGLT2Is) have beneficial effects on the renal function of chronic kidney disease (CKD) patients, although the types of patients suitable for this treatment remain unclear.

METHODS

A retrospective observational study was conducted on CKD patients who were treated with SGLT2I in our department from 2020 to 2023. The estimated glomerular filtration rate (eGFR) just before treatment was defined as the baseline and the difference between pre-and post-treatment eGFR slopes were used to compare the improvement of renal function. Logistic regression analysis was used to evaluate the independent factors for its improvement.

RESULTS

A total of 128 patients were analyzed (mean age: 67.2 years; number of women: 28 [22%]). The mean eGFR was 42.1 mL/min/1.73 m2, and urine protein was 0.66 g/gCr. The eGFR slopes of patients with an eGFR <30 mL/min/1.73 m2 were improved significantly after treatment (-0.28 to -0.14 mL/min/1.73 m2/month, p < 0.001) but were worsened in patients with an eGFR ≥30 mL/min/1.73 m2. Logistic analysis for the improvement in eGFR slopes showed that women (odds ratio [OR], 5.63; 95% confidence interval [CI], 1.16-27.3; p = 0.03), use of mineralocorticoid receptor antagonists (OR, 11.79; 95% CI, 1.05-132.67; p = 0.012) and rapid decline of eGFR before treatment (OR, 12.8 per mL/min/1.73 m2/month decrease in eGFR; 95% CI, 3.32-49.40; p < 0.001) were significant independent variables.

CONCLUSION

SGLT2Is may have beneficial effects, especially for rapid decliners of eGFR, including advanced CKD.

SGLT2 inhibition promotes glomerular repopulation by cells of renin lineage in experimental kidney disease

AIM

Sodium glucose co-transporter-2 (SGLT2) inhibitors stimulate renal excretion of sodium and glucose and exert renal protective effects in patients with (non-)diabetic chronic kidney disease (CKD) and may as well protect against acute kidney injury (AKI). The mechanism behind this kidney protective effect remains unclear. Juxtaglomerular cells of renin lineage (CoRL) have been demonstrated to function as progenitors for multiple adult glomerular cell types in kidney disease. This study assesses the impact of SGLT2 inhibition on the repopulation of glomerular cells by CoRL and examines their phenotypic commitment.

METHODS

Experiments were performed in Ren1cre-tdTomato lineage-trace mice. Either 5/6 nephrectomy (5/6NX) modeling CKD or bilateral ischaemia reperfusion injury (bIRI) mimicking AKI was applied, while the SGLT2 inhibitor empagliflozin (10 mg/kg) was administered daily via oral gavage for 14 days.

RESULTS

Both 5/6NX and bIRI-induced kidney injury increased the number of glomerular CoRL-derived cells. SGLT2 inhibition improved kidney function after 5/6NX, indicated by decreased blood creatinine and urea levels, but not after bIRI. In line with this, empagliflozin in 5/6NX animals resulted in less glomerulosclerosis, while it did not affect histopathological features in bIRI. Treatment with empagliflozin resulted in an increase in the number of CoRL-derived glomerular cells in both 5/6NX and bIRI conditions. Interestingly, SGLT2 inhibition led to more CoRL-derived podocytes in 5/6NX animals, whereas empagliflozin-treated bIRI mice presented with increased levels of parietal epithelial and mesangial cells derived from CoRL.

CONCLUSION

We conclude that SGLT2 inhibition by empagliflozin promotes CoRL-mediated glomerular repopulation with selective CoRL-derived cell types depending on the type of experimental kidney injury. These findings suggest a previously unidentified mechanism that could contribute to the renoprotective effect of SGLT2 inhibitors.

Transient inhibition of sodium-glucose cotransporter 2 after ischemia/reperfusion injury ameliorates chronic kidney disease

Sodium-glucose cotransporter 2 (SGLT2) inhibitor, dapagliflozin (Dapa), exhibited nephroprotective effects in patients with chronic kidney disease (CKD). We assessed the efficacy of short-term Dapa administration following acute kidney injury (AKI) in preventing CKD. Male Wistar rats were randomly assigned to Sham surgery, bilateral ischemia for 30 minutes (abbreviated as IR), and IR + Dapa groups. Daily treatment with Dapa was initiated just 24 hours after IR and maintained for only 10 days. Initially, rats were euthanized at this point to study early renal repair. After severe AKI, Dapa promptly restored creatinine clearance (CrCl) and significantly reduced renal vascular resistance compared with the IR group. Furthermore, Dapa effectively reversed the mitochondrial abnormalities, including increased fission, altered mitophagy, metabolic dysfunction, and proapoptotic signaling. To study this earlier, another set of rats was studied just 5 days after AKI. Despite persistent renal dysfunction, our data reveal a degree of mitochondrial protection. Remarkably, a 10-day treatment with Dapa demonstrated effectiveness in preventing CKD transition in an independent cohort monitored for 5 months after AKI. This was evidenced by improvements in proteinuria, CrCl, glomerulosclerosis, and fibrosis. Our findings underscore the potential of Dapa in preventing maladaptive repair following AKI, emphasizing the crucial role of early intervention in mitigating AKI long-term consequences.

SGLT2 inhibitor dapagliflozin protects the kidney in a murine model of Balkan nephropathy

Proximal tubular uptake of aristolochic acid (AA) forms aristolactam (AL)-DNA adducts, which cause a p53/p21-mediated DNA damage response and acute tubular injury. Recurrent AA exposure causes kidney function loss and fibrosis in humans (Balkan endemic nephropathy) and mice and is a model of (acute kidney injury) AKI to chronic kidney disease (CKD) transition. Inhibitors of the proximal tubule sodium-glucose transporter SGLT2 can protect against CKD progression, but their effect on AA-induced kidney injury remains unknown. C57BL/6J mice (15-wk-old) were administered vehicle or AA every 3 days for 3 wk (10 and 3 mg/kg ip in females and males, respectively). Dapagliflozin (dapa, 0.01 g/kg diet) or vehicle was initiated 7 days prior to AA injections. All dapa effects were sex independent, including a robust glycosuria. Dapa lowered urinary kidney-injury molecule 1 (KIM-1) and albumin (both normalized to creatinine) after the last AA injection and kidney mRNA expression of early DNA damage response markers (p53 and p21) 3 wk later at the study end. Dapa also attenuated AA-induced increases in plasma creatinine as well as AA-induced up-regulation of renal pro-senescence, pro-inflammatory and pro-fibrotic genes, and kidney collagen staining. When assessed 1 day after a single AA injection, dapa pretreatment attenuated AL-DNA adduct formation by 10 and 20% in kidney and liver, respectively, associated with reduced p21 expression. Initiating dapa application after the last AA injection also improved kidney outcome but in a less robust manner. In conclusion, the first evidence is presented that pretreatment with an SGLT2 inhibitor can attenuate the AA-induced DNA damage response and subsequent nephropathy.NEW & NOTEWORTHY Recurrent exposure to aristolochic acid (AA) causes kidney function loss and fibrosis in mice and in humans, e.g., in the form of the endemic Balkan nephropathy. Inhibitors of the proximal tubule sodium-glucose transporter SGLT2 can protect against CKD progression, but their effect on AA-induced kidney injury remains unknown. Here we provide the first evidence in a murine model that pretreatment with an SGLT2 inhibitor can attenuate the AA-induced DNA damage response and subsequent nephropathy.

The safety of SGLT-2 inhibitors in diabetic patients submitted to elective percutaneous coronary intervention regarding kidney function: SAFE-PCI pilot study

BACKGROUND

Percutaneous coronary intervention (PCI) is one of the most performed well-succeeded therapeutic procedures worldwide, reducing symptoms and improving quality of life. Neutrophil Gelatinase-associated Lipocalin (NGAL) is a biomarker of acute kidney injury (AKI) produced early after an ischemic renal insult. Osmotic diuresis and the vasoconstriction of the afferent arteriole promoted by Sodium-glucose Cotransporter-2 Inhibitors (SGLT2i) generate a concern regarding the possibility of dehydration and consequent AKI. There is no consensus on the maintenance or discontinuation of SGTL2i in patients who will undergo PCI. This study aimed to evaluate the safety of empagliflozin in diabetic patients submitted to elective PCI regarding kidney function.

METHODS

SAFE-PCI trial is a prospective, open-label, randomized (1:1), single-center pilot study and a follow-up of 30 days. The SGLT2i empagliflozin 25 mg daily was initiated at least 15 days before PCI in the intervention group and maintained until the end of the follow-up period. Serum NGAL was collected 6 h after PCI and creatinine before PCI, 24 h, and 48 h after the procedure. As per protocol, both groups received optimal medical treatment and standard protocol of nephroprotection.

RESULTS

A total of 42 patients were randomized (22 patients in the iSGLT-2 group and 20 patients in the control group). There was no difference between-group baseline data. The primary outcome (NGAL and creatinine values post PCI) did not differ in both groups: the mean NGAL value was 199 ng/dL in the empagliflozin group and 150 ng/dL in the control group (p = 0.249). Although there was an initial increase in creatinine in the SGLT-2i group compared to the control group between baseline creatinine and pre-PCI and 24 h post-PCI creatinine, no difference was detected in creatinine 48 h post-PCI (p = 0.065). The incidence of CI-AKI, determined by KDIGO criteria, in the iSGLT2-group was 13.6% and 10.0% in the control group without statistical difference.

CONCLUSION

The present study showed that the use of empagliflozin is safe regarding kidney function during elective PCI in patients with T2D when compared with no use of SGLT2i. Trial registration Our clinical study is registered on ClinicalTrials.gov with the following number: NCT05037695.

Empagliflozin improves renal ischemia-reperfusion injury by reducing inflammation and enhancing mitochondrial fusion through AMPK-OPA1 pathway promotion

BACKGROUND

Renal ischemia-reperfusion injury (IRI) is one reason for renal transplantation failure. Recent studies have shown that mitochondrial dynamics is closely related to IRI, and that inhibition or reversal of mitochondrial division protects organs against IRI. Optic atrophy protein 1 (OPA1), an important factor in mitochondrial fusion, has been shown to be upregulated by sodium-glucose cotransporter 2 inhibitor (SGLT2i). Also, the antiinflammatory effects of SGLT2i have been demonstrated in renal cells. Thus, we hypothesized that empagliflozin could prevent IRI through inhibiting mitochondrial division and reducing inflammation.

METHODS

Using hematoxylin-eosin staining, enzyme linked immunosorbent assay (ELISA), flow cytometry, immunofluorescent staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining, real-time PCR, RNA-sequencing, and western blot, we analyzed renal tubular tissue from in vivo and in vitro experiments.

RESULTS

Through animal experiments and sequencing analysis, we first confirmed the protection against IRI and the regulation of mitochondrial dynamics-related factors and inflammatory factors by empagliflozin pretreatment. Then, through hypoxia/reoxygenation (H/R) cellular experiments, we confirmed that empagliflozin could inhibit mitochondrial shortening and division and upregulate OPA1 in human renal tubular epithelial cell line (HK-2) cells. Subsequently, we knocked down OPA1, and mitochondrial division and shortening were observed, which could be alleviated by empagliflozin treatment. Combined with the previous results, we concluded that OPA1 downregulation leads to mitochondrial division and shortening, and empagliflozin can alleviate the condition by upregulating OPA1. We further explored the pathway through which empagliflozin functions. Related studies have shown the activation of AMPK pathway by empagliflozin and the close correlation between the AMPK pathway and OPA1. In our study, we blocked the AMPK pathway, and OPA1 upregulation by empagliflozin was not observed, thus demonstrating the dependence of empagliflozin on the AMPK pathway.

CONCLUSION

The results indicated that empagliflozin could prevent or alleviate renal IRI through antiinflammatory effects and the AMPK-OPA1 pathway. Ischemia-reperfusion injury is an inevitable challenge in organ transplantation. It is necessary to develop a new therapeutic strategy for IRI prevention in addition to refining the transplantation process. In this study, we confirmed the preventive and protective effects of empagliflozin in renal ischemia-reperfusion injury. Based on these findings, empagliflozin is promising to be a preventive agent for renal ischemia-reperfusion injury and can be applied for preemptive administration in kidney transplantation.

Acute kidney injury in diabetes mellitus: Epidemiology, diagnostic, and therapeutic concepts

Acute kidney injury (AKI) and diabetes mellitus (DM) are public health problems that cause a high socioeconomic burden worldwide. In recent years, the landscape of AKI etiology has shifted: Emerging evidence has demonstrated that DM is an independent risk factor for the onset of AKI, while an alternative perspective considers AKI as a bona fide complication of DM. Therefore, it is necessary to systematically characterize the features of AKI in DM. In this review, we summarized the epidemiology of AKI in DM. While focusing on circulation- and tissue-specific microenvironment changes after DM, we described the active cellular and molecular mechanisms of increased kidney susceptibility to AKI under DM stress. We also reviewed the current diagnostic and therapeutic strategies for AKI in DM recommended in the clinic. Updated recognition of the epidemiology, pathophysiology, diagnosis, and medications of AKI in DM is believed to reveal a path to mitigate the frequency of AKI and DM comorbidity that will ultimately improve the quality of life in DM patients.

Network pharmacology, molecular docking, and experimental verification reveal the mechanism of San-Huang decoction in treating acute kidney injury

Background: Cisplatin is an effective anti-tumor drug. However, its usage is constrained by side effects such as nephron toxicity. Cisplatin-induced acute kidney injury (AKI) appears in approximately 20%-30% of cases. Hence, finding an effective protective strategy is necessary. San-Huang decoction (SHD) is a Chinese herbal decoction with good efficacy in treating chronic kidney disease (CKD). Nevertheless, the mechanism of SHD on AKI remains unclear. Consequently, we proposed to explore the potential mechanism of SHD against cisplatin-induced AKI. Methods: Active compounds, core target proteins, and associated signaling pathways of SHD were predicted through network pharmacology. Then confirmed by molecular docking. In vivo experiment, Cisplatin + SHD group was treated with SHD (6.5 g/kg/day) for 6 days before building the model. An AKI model was established with a single intraperitoneal injection of cisplatin at 20 mg/kg. After 72 h of cisplatin injection, all mice were sacrificed to collect blood and kidney tissues for verification of network pharmacology analysis. Results: We found that calycosin, rhein, and ginsenoside Rh2 may be SHD's primary active compounds in treating cisplatin-induced AKI, and AKT, TNF-α, IL-6, IL-1β, caspase-3, and MMP9 are the core target proteins. The relationship between the compound and target protein was further confirmed by molecular docking. The Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses predicted that SHD has an anti-inflammatory role through the TNF and IL-17 signaling pathway. Moreover, Western blot and immunohistochemistry validated the potential molecular mechanisms of SHD, predicted from network pharmacology analysis. The mechanism of cisplatin-induced AKI involves apoptosis and inflammation. In apoptosis, Caspase-3, caspase-8, caspase-9, and Bax proteins were down-regulated, while Bcl-2 was up-regulated by SHD. The differential expression of MMP protein is involved in the pathological process of AKI. MMP9 protects from glomerular tubule damage. MMP9 and PI3K/AKT anti-apoptosis pathway were up-regulated by SHD. In addition, we discovered that SHD alleviated AKI by inhibiting the NF-κB signaling pathway. Conclusion: SHD plays a critical role in anti-inflammation and anti-apoptosis via inhibiting the NF-κB signaling pathway and activating PI3K/AKT anti-apoptosis pathway, indicating that SHD is a candidate herbal drug for further investigation in treating cisplatin-induced AKI.

The effect of dapagliflozin on myocardial ischemia-reperfusion injury in diabetic rats

The incidence of ischemic heart disease is 2-3 times higher in diabetic patients. However, the effect of dapagliflozin on ischemia-reperfusion myocardial injury in diabetic rats has not been studied. We examined the effects of dapagliflozin on myocardial IR injury in streptozotocin-nicotinamide-induced diabetic rats. Rats were divided into four groups (n = 7 in each group): control, control-dapagliflozin, diabetes, and diabetes-dapagliflozin. Dapagliflozin (1.5 mg/kg/day) was administered concomitantly in drinking water for 2 months. The hearts were perfused in a Langendorff's apparatus at 2 months and assessed before (baseline) and after myocardial IR for the following parameters: left ventricular developed pressure (LVDP), minimum and maximum rates of pressure change in the left ventricle (±dP/dt), endothelial nitric oxide (NO) synthase (eNOS) and inducible NO synthase (iNOS) mRNA expressions, creatine kinase MB (CK-MB) and troponin imyocardial enzyme extravasation, and lactate dehydrogenase. The recovery of LVDP and ±dP/dt in diabetic rats was lower than that in controls but near normal after dapagliflozin treatment. Diabetic rats had decreased eNOS expression and increased iNOS expression at baseline and after IR, whereas dapagliflozin normalized these parameters after IR. Compared with controls, cardiac NOx levels were initially lower in diabetic patients but higher after IR. Baseline MDA levels were higher in diabetic rats after IR, whereas cardiac NOx levels decreased after treatment with dapagliflozin. Dapagliflozin protects the diabetic rat heart from ischemia-reperfusion myocardial injury by regulating the expression of eNOS and iNOS and inhibiting cardiac lipid peroxidation.

Renal outcomes with sodium-glucose cotransporters 2 inhibitors

Diabetic nephropathy (DN) is one of the most serious complications of diabetes. Therefore, delaying and preventing the progression of DN becomes an important goal in the clinical treatment of type 2 diabetes mellitus. Recent studies confirm that sodium-glucose cotransporters 2 inhibitors (SGLT2is) have been regarded as effective glucose-lowering drugs with renal protective effect. In this review, we summarize in detail the present knowledge of the effects of SGLT2is on renal outcomes by analyzing the experimental data in preclinical study, the effects of SGLT2is on estimated glomerular flitration rates (eGFRs) and urinary albumin-creatinine ratios (UACRs) from clinical trials and observational studies, and renal events (such as renal death or renal failure requiring renal replacement therapy) in some large prospective cardiovaslucar outcomes trials. The underlying mechanisms for renoprotective activity of SGLT2is have been demondtrated in multiple diabetic and nondiabetic animal models including kidney-specific effects and secondary kidney effects related to amelioration in blood glucose and blood pressure. In conclusion, these promising results show that SGLT2is act beneficially in terms of the kidney for diabetic patients.

Empagliflozin protects against renal ischemia/reperfusion injury in mice

Renal ischemia/reperfusion (I/R) can induce acute kidney injury. Empagliflozin is a newly developed inhibitor of sodium-glucose cotransporter-2 (SGLT2) approved as an antidiabetic medication for patients with type 2 diabetes mellitus. Despite the established cardioprotective functions of empagliflozin, its protective role in renal I/R is unclear. Here, the present study evaluated the renoprotective effects of empagliflozin in a mouse model of renal I/R injury. Male C57/BL6 mice were allocated to sham-operated, I/R, and empagliflozin groups. Kidney pedicles on both sides were clamped for 45 min and were reperfused for 24 h. Empagliflozin (1 mg/kg) was administered to the mice for 2 days preischemia. The GSK-3β inhibitor SB216763 was administered intravenously at the beginning of reperfusion (0.1 mg/kg). Renal function and histological scores were evaluated. The kidneys were taken for immunohistochemical analysis, western blotting and apoptosis measurements. We found that empagliflozin decreased serum levels of creatinine and urea, reduced the average kidney weight-to-tibia length ratio, attenuated tubular damage, reduced renal proinflammatory cytokine expression and inhibited apoptosis in injured kidneys. Furthermore, empagliflozin increased renal glycogen synthase kinase 3β (GSK-3β) phosphorylation post I/R. Pharmacological inhibition of GSK-3β activity mimicked the renal protective effects offered by empagliflozin. In summary, these results support a protective role of empagliflozin against renal I/R injury.

Critical Reanalysis of the Mechanisms Underlying the Cardiorenal Benefits of SGLT2 Inhibitors and Reaffirmation of the Nutrient Deprivation Signaling/Autophagy Hypothesis

SGLT2 (sodium-glucose cotransporter 2) inhibitors produce a distinctive pattern of benefits on the evolution and progression of cardiomyopathy and nephropathy, which is characterized by a reduction in oxidative and endoplasmic reticulum stress, restoration of mitochondrial health and enhanced mitochondrial biogenesis, a decrease in proinflammatory and profibrotic pathways, and preservation of cellular and organ integrity and viability. A substantial body of evidence indicates that this characteristic pattern of responses can be explained by the action of SGLT2 inhibitors to promote cellular housekeeping by enhancing autophagic flux, an effect that may be related to the action of these drugs to produce simultaneous upregulation of nutrient deprivation signaling and downregulation of nutrient surplus signaling, as manifested by an increase in the expression and activity of AMPK (adenosine monophosphate-activated protein kinase), SIRT1 (sirtuin 1), SIRT3 (sirtuin 3), SIRT6 (sirtuin 6), and PGC1-α (peroxisome proliferator-activated receptor γ coactivator 1-α) and decreased activation of mTOR (mammalian target of rapamycin). The distinctive pattern of cardioprotective and renoprotective effects of SGLT2 inhibitors is abolished by specific inhibition or knockdown of autophagy, AMPK, and sirtuins. In the clinical setting, the pattern of differentially increased proteins identified in proteomics analyses of blood collected in randomized trials is consistent with these findings. Clinical studies have also shown that SGLT2 inhibitors promote gluconeogenesis, ketogenesis, and erythrocytosis and reduce uricemia, the hallmarks of nutrient deprivation signaling and the principal statistical mediators of the ability of SGLT2 inhibitors to reduce the risk of heart failure and serious renal events. The action of SGLT2 inhibitors to augment autophagic flux is seen in isolated cells and tissues that do not express SGLT2 and are not exposed to changes in environmental glucose or ketones and may be related to an ability of these drugs to bind directly to sirtuins or mTOR. Changes in renal or cardiovascular physiology or metabolism cannot explain the benefits of SGLT2 inhibitors either experimentally or clinically. The direct molecular effects of SGLT2 inhibitors in isolated cells are consistent with the concept that SGLT2 acts as a nutrient surplus sensor, and thus, its inhibition causes enhanced nutrient deprivation signaling and its attendant cytoprotective effects, which can be abolished by specific inhibition or knockdown of AMPK, sirtuins, and autophagic flux.

Prevention of LPS-Induced Acute Kidney Injury in Mice by Bavachin and Its Potential Mechanisms

Acute kidney injury (AKI) is a serious complication of sepsis with a rapid onset and high mortality rate. Bavachin, an active component of Psoralea corylifolia L., reportedly has antioxidant, anti-apoptotic, and anti-inflammatory effects; however, its beneficial effects on AKI remain undetermined. We investigated the protective effect of bavachin on lipopolysaccharide (LPS)-induced AKI in mice and elucidated the underlying mechanism in human renal tubular epithelial HK-2 cells. Increased serum creatinine and blood urea nitrogen levels were observed in LPS-injected mice; however, bavachin pretreatment significantly inhibited this increase. Bavachin improved the kidney injury score and decreased the expression level of tubular injury markers, such as neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1), in both LPS-injected mice and LPS-treated HK-2 cells. LPS-induced oxidative stress via phosphorylated protein kinase C (PKC) β and upregulation of the NADPH oxidase (NOX) 4 pathway was also significantly decreased by treatment with bavachin. Moreover, bavachin treatment inhibited the phosphorylation of MAPKs (P38, ERK, and JNK) and nuclear factor (NF)-κB, as well as the increase in inflammatory cytokine levels in LPS-injected mice. Krüppel-like factor 5 (KLF5) expression was upregulated in the LPS-treated HK-2 cells and kidneys of LPS-injected mice. However, RNAi-mediated silencing of KLF5 inhibited the phosphorylation of NF-kB, consequently reversing LPS-induced KIM-1 and NGAL expression in HK-2 cells. Therefore, bavachin may ameliorate LPS-induced AKI by inhibiting oxidative stress and inflammation via the downregulation of the PKCβ/MAPK/KLF5 axis.

AMPK: The key to ischemia-reperfusion injury

Ischemia-reperfusion injury (IRI) refers to a syndrome in which tissue damage is further aggravated and organ function further deteriorates when blood flow is restored after a period of tissue ischemia. Acute myocardial infarction, stress ulcer, pancreatitis, intestinal ischemia, intermittent claudication, acute tubular necrosis, postshock liver failure, and multisystem organ failure are all related to reperfusion injury. AMP-activated protein kinase (AMPK) has been identified in multiple catabolic and anabolic signaling pathways. The functions of AMPK during health and diseases are intriguing but still need further research. Except for its conventional roles as an intracellular energy switch, emerging evidence reveals the critical role of AMPK in IRI as an energy-sensing signal molecule by regulating metabolism, autophagy, oxidative stress, inflammation, and other progressions. At the same time, drugs based on AMPK for the treatment of IRI are constantly being researched and applied in clinics. In this review, we summarize the mechanisms underlying the effects of AMPK in IRI and describe the AMPK-targeting drugs in treatment, hoping to increase the understanding of AMPK in IRI and provide new insights into future clinical treatment.

A review of potential mechanisms and uses of SGLT2 inhibitors in ischemia-reperfusion phenomena

Recently added to the therapeutic arsenal against chronic heart failure as a first intention drug, the antidiabetic drug-class sodium-glucose cotransporter-2 inhibitors (SGLT2i) showed efficacy in decreasing overall mortality, hospitalization, and sudden death in patients of this very population, in whom chronic or acute ischemia count among the first cause. Remarkably, this benefit was observed independently from diabetic status, and benefited both preserved and altered ventricular ejection fraction. This feature, observed in several large randomized controlled trials, suggests additional effects from SGLT2i beyond isolated glycemia control. Indeed, both in-vitro and animal models suggest that inhibiting the Na⁺/H⁺ exchanger (NHE) may be key to preventing ischemia/ reperfusion injuries, and by extension may hold a similar role in ischemic damage control and ischemic preconditioning. Yet, several other mechanisms may be explored which may help better target those who may benefit most from SGLT2i molecules. Because of a large therapeutic margin with few adverse events, ease of prescription and potential pharmacological efficacity, SGLT2i could be candidate for wider indications. In this review, we aim to summarize all evidence which link SGLT2i and ischemia/reperfusion injuries modulation, by first listing known mechanisms, including metabolic switch, prevention of lethal arrythmias and others, which portend the latter, and second, hypothesize how the former may interact with these mechanisms.

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.

Effect of dual inhibition of DPP4 and SGLT2 on tacrolimus-induced diabetes mellitus and nephrotoxicity in a rat model

Sodium/glucose co-transporter-2 inhibitor (SGLT2i) or dipeptidyl peptidase IV inhibitor (DPP4i) is a newer anti-diabetic drug in type II diabetes mellitus (DM), but their use in tacrolimus (TAC)-induced DM is still undetermined. We performed this study to evaluate the effect of these two drugs in TAC-induced DM and nephrotoxicity in ex vivo and in vivo. In the experimental Sprague Dawley rat model of TAC-induced DM and nephrotoxicity, dual inhibition of DPP4 and SGLT2 significantly decreased blood glucose level, HbA1C and increased plasma insulin levels and pancreatic islet size compared with each drug. In the kidney, dual inhibition improved renal function decreased interstitial fibrosis and profibrotic cytokines compared with DPP4i and SGLT2i alone. Increased oxidative stress by TAC was remarkably decreased with DPP4i or SGLT2i in serum, pancreatic and renal tissues and this decrease was much more significant in the combination group. In in vitro study, TAC decreased the cell viability of human kidney-2(HK-2) cells and insulin-secreting beta-cell-derived line(INS-1) cells. SGLT2i protected TAC-induced cell death in HK-2 cells, but not in INS-1 cells. The addition of DPP4i to SGLT2i compensated for a lack of protective effect of SGLT2i on INS-1 cells. This finding provides the rationale for the combined treatment of SGLG2i and DPP4i in TAC-induced DM and nephrotoxicity.

Protective effect of saxagliptin against renal ischaemia reperfusion injury in rats

Saxagliptin is an effective and selective dipeptidyl peptidase-4 (DPP-4) inhibitor. This study was designed to determine possible protective effects of saxagliptin against damage caused by renal ischaemia/reperfusion (I/R) in rats. In this study, 40 rats were divided into 4 groups (n = 10 for each). Group 1 (Control), Group 2 (I/R) in both kidneys ischaemia of 45 min was performed, and then reperfusion was applied for 24 h. Saxagliptin (Group 3: 2 mg/kg and Group 4: 10 mg/kg) was administered by oral gavage to the animals in treatment groups, before the I/R. Saxagliptin decreased the markers (BUN, Cre, NGAL, KIM-1 and IL-18) of acute renal damage in blood and kidney tissue. Saxagliptin provided increase in antioxidant enzyme levels and decrease in MDA and apoptosis. Histological results showed that the administration of saxagliptin exhibited a protective effect against renal damage caused by I/R. These results indicates that saxagliptin provide protection against kidney injury caused by I/R.

Fatty kidney: A possible future for chronic kidney disease research

BACKGROUND

Metabolic syndrome is a growing twenty-first century pandemic associated with multiple clinical comorbidities ranging from cardiovascular diseases, non-alcoholic fatty liver disease and polycystic ovary syndrome to kidney dysfunction. A novel area of research investigates the concept of fatty kidney in the pathogenesis of chronic kidney disease, especially in patients with diabetes mellitus or metabolic syndrome.

AIM

To review the most updated literature on fatty kidney and provide future research, diagnostic and therapeutic perspectives on a disease increasingly affecting the contemporary world.

MATERIALS AND METHOD

We performed an extensive literature search through three databases including Embase (Elsevier) and the Cochrane Central Register of Controlled Trials (Wiley) and PubMed/Medline Web of Science in November 2021 by using the following terms and their combinations: 'fatty kidney', 'ectopic fat', 'chronic kidney disease', 'cardiovascular event', 'cardio-metabolic risk', 'albuminuria' and 'metabolic syndrome'. Each study has been individually assessed by the authors.

RESULTS

Oxidative stress and inflammation, Klotho deficiency, endoplasmic reticulum stress, mitochondrial dysfunction and disruption of cellular energy balance appear to be the main pathophysiological mechanisms leading to tissue damage following fat accumulation. Despite the lack of large-scale comprehensive studies in this novel field of research, current clinical trials demonstrate fatty kidney as an independent risk factor for the development of chronic kidney disease and cardiovascular events.

CONCLUSION

The requirement for future studies investigating the pathophysiology, clinical outcomes and therapeutics of fatty kidney is clear.

Dapagliflozin protects neural and vascular dysfunction of the retina in diabetes

INTRODUCTION

Dapagliflozin, a sodium-glucose transporter inhibitor, effectively reduces blood glucose and is indicated for individuals with kidney diseases and cardiovascular disorders. In this study, we further expand the therapeutic benefit of dapagliflozin in the neural and vascular retina, with the potential to effectively manage diabetic retinopathy (DR), the most common complication of diabetes.

RESEARCH DESIGN AND METHODS

Db/db mice, an animal model of type 2 diabetes, were treated with dapagliflozin orally, and the electroretinogram (ERG) response and acellular capillary numbers were assessed. Messenger RNA levels of inflammatory cytokines were studied using real-time quantitative (q)PCR. We assessed endothelial cell migration in a scratch wound assay and retinal glucose uptake using human retinal endothelial cells.

RESULTS

The dapagliflozin treatment improved the ERG b-wave amplitude and decreased acellular capillary numbers. The scratch wound assay demonstrated a reduction in wound closure after dapagliflozin treatment. Retinal glucose uptake reduced after dapagliflozin treatment compared with the respective controls.

CONCLUSIONS

Our studies suggest that dapagliflozin treatment effectively corrects neural and vascular dysfunction of the retina in diabetes. This effect is mediated by a decrease in inflammation and improved glycemic control. In addition, dapagliflozin exhibits decreased wound healing and glucose uptake, which could benefit the retina. Thus, dapagliflozin could be helpful in the management of DR, with multimodal therapeutic effects.

Dapagliflozin Ameliorates Lipopolysaccharide Related Acute Kidney Injury in Mice with Streptozotocin-induced Diabetes Mellitus

Sepsis, which is a serious medical condition induced by infection, has been the most common cause of acute kidney injury (AKI) and is associated with high mortality and morbidity. Sodium-glucose cotransporter 2 (SGLT2) inhibitor is a new oral antidiabetic drug that has greatly improved the cardiovascular and renal outcomes in patients with type 2 diabetes independent of its sugar lowering effect, possibly by attenuation of the inflammatory process. We investigated the effect of the SGLT2 inhibitor dapagliflozin on lipopolysaccharide (LPS)-induced endotoxic shock with AKI in streptozotocin-induced diabetic mice. Endotoxin shock with AKI was induced by intravenous injection of 10 mg/kg LPS in C57BL6 mice with streptozotocin-induced diabetic mellitus with or without dapagliflozin treatment. Observation was done for 48 hours thereafter. In addition, NRK-52E cells incubated with LPS or dapagliflozin were evaluated for the possible mechanism. Treatment with dapagliflozin attenuated LPS-induced endotoxic shock associated AKI and decreased the inflammatory cytokines in diabetic mice. In the in vitro study, dapagliflozin decreased the expression of inflammatory cytokines and reactive oxygen species and increased the expressions of AMP-activated protein kinase (AMPK), nuclear factor erythroid-2-related factor, and heme oxygenase 1. These results demonstrated that dapagliflozin can attenuate LPS-induced endotoxic shock associated with AKI; this was possibly mediated by activation of the AMPK pathway.

Dapagliflozin Reduces Apoptosis of Diabetic Retina and Human Retinal Microvascular Endothelial Cells Through ERK1/2/cPLA2/AA/ROS Pathway Independent of Hypoglycemic

Introduction: It is known that the metabolic disorder caused by high glucose is one of pathogenesis in diabetic retinopathy (DR), the leading cause of blindness, due to the main pathological change of apoptosis of endothelial cells (ECs). In previous studies, the potential impact of sodium glucose cotransporter-2 (SGLT-2), whose inhibitors slow the progression of DR, has not been elucidated. The purpose of the presented study was to explore the effect of SGLT-2 inhibitors dapagliflozin (DAPA) on apoptosis of diabetic mice retina and human retinal microvascular endothelial cells (HRMECs), examine the effects of dapagliflozin on HRMECs metabolism, and explore the molecular processes that affect DR.

Methods and Results: The eyeballs of male streptozotocin (STZ)-induced diabetic C57BL/6N mice were evaluated. C57BL/6N mice were divided into control group (CON), diabetic untreated group (DM), diabetic dapagliflozin treatment group (DM + DAPA) and diabetic insulin treatment group (DM + INS). Hematoxylin-Eosin (HE) staining was performed to observe the pathological structure of the mice retina, and TUNEL staining to detect apoptosis of mice retinal cells. In vitro, DCFH-DA and western blot (WB) were used to evaluate ROS, Bcl-2, BAX, cleaved-caspase 3 in HRMECs and metabolomics detected the effect of dapagliflozin on the metabolism of HRMECs. And then, we performed correlation analysis and verification functions for significantly different metabolites. In vivo, dapagliflozin reduced the apoptosis of diabetic mice retina independently of hypoglycemic. In vitro, SGLT-2 protein was expressed on HRMECs. Dapagliflozin reduced the level of ROS caused by high glucose, decreased the expression of cleaved-caspase3 and the ratio of BAX/Bcl-2. Metabolomics results showed that dapagliflozin did not affect the intracellular glucose level. Compared with the high glucose group, dapagliflozin reduced the production of arachidonic acid (AA) and inhibited the phosphorylation of ERK1/2, therefore, reducing the phosphorylation of cPLA2, which is a key enzyme for arachidonic acid release.

Conclusion: Collectively, results unearthed for the first time that dapagliflozin reduced apoptosis of retina induced by DM whether in vivo or in vitro. Dapagliflozin did not affect the glucose uptake while mitigated intracellular arachidonic acid in HRMECs. Dapagliflozin alleviated HRMECs apoptosis induced by high glucose through ERK/1/2/cPLA2/AA/ROS pathway.

Sodium-Glucose Cotransporter 2 Inhibitors and Cardiac Remodeling

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

Dapagliflozin Alleviates Renal Fibrosis by Inhibiting RIP1-RIP3-MLKL-Mediated Necroinflammation in Unilateral Ureteral Obstruction

Dapagliflozin, a sodium-glucose cotransporter-2 inhibitor, offers renoprotection in diabetes. However, potential for use in nondiabetic kidney disease remains unknown. Herein, we assessed whether dapagliflozin alleviates renal fibrosis by interfering with necroinflammation in a rat model of unilateral ureteral obstruction (UUO) and in vitro. After induction of UUO, rats were administered dapagliflozin daily for seven consecutive days. UUO induced significant renal tubular necrosis and overexpression of RIP1-RIP3-MLKL axis proteins; these coincided with NLRP3 inflammasome activation, and subsequent development of renal fibrosis. Oxidative stress caused by UUO is tightly associated with endoplasmic reticulum stress and mitochondrial dysfunction, leading to apoptotic cell death through Wnt3α/β-catenin/GSK-3β signaling; all of which were abolished by both dapagliflozin and specific RIP inhibitors (necrostatin-1 and GSK872). In H₂O₂-treated HK-2 cells, dapagliflozin and RIP inhibitors suppressed overexpression of RIP1-RIP3-MLKL proteins and pyroptosis-related cytokines, decreased intracellular reactive oxygen species production and apoptotic cell death, whereas cell viability was improved. Moreover, activated Wnt3α/β-catenin/GSK-3β signaling was inhibited by dapagliflozin and Wnt/β-catenin inhibitor ICG-001. Our findings suggest that dapagliflozin ameliorates renal fibrosis by inhibiting RIP1-RIP3-MLKL-mediated necroinflammation via Wnt3α/β-catenin/GSK-3β signaling in UUO.

Extending the ambit of SGLT2 inhibitors beyond diabetes: a review of clinical and preclinical studies on non-diabetic kidney disease

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) are novel antidiabetic agents with overwhelming cardiorenal protection. Recent trials focusing on the nephroprotective role of SGLT2i have underscored its success as a phenomenal agent in halting the progression of kidney disease in patients with and without Type 2 diabetes mellitus. Multitudes of pleiotropic effects on tubules have raised hopes for reasonable nephroprotection beyond the purview of the hyperglycemic milieu.

AREA COVERED

This review summarizes various animal and human data as evidence for the utility of SGLT2i in non-diabetic chronic kidney disease (CKD). Web-based medical database entries were searched. On the premise of existing evidence, we have discussed mechanisms likely contributing to nephroprotection by SGLT2i in patients with non-diabetic CKD.

EXPERT OPINION

Further elucidation of mechanisms of nephroprotection offered by SGLT2i is required to extend its use as a nephroprotective agent. The use of non-traditional markers of kidney damage in future studies would improve the evaluation of their role in attenuating CKD progression. Emerging animal data support the early use of SGLT2i in states of modest proteinuria for superior outcomes. Future long-term trials in patients should aim to address the time of intervention with SGLT2i during the natural disease course of CKD for best outcomes.

Dapagliflozin Guards Against Cadmium-Induced Cardiotoxicity via Modulation of IL6/STAT3 and TLR2/TNFα Signaling Pathways

Cadmium (Cd) is a common environmental pollutant that leads to severe cardiotoxic hazards. Several studies were carried out to protect the myocardium against Cd-induced cardiotoxicity. Up till now, no researches evaluated the protective effect of dapagliflozin (DAP) against Cd induced cardiotoxicity. Thus, we aimed to explore the role of DAP in such model with deep studying of the involved mechanisms. 40 male Wistar albino rats were included in current study. Cd (5 mg/kg/day) was administered orally for 7 days to induce cardiotoxicity with or without co-administration of DAP in three different doses (2.5, 5, 10 mg/kg/day) orally for 7 days. Our data revealed that Cd could induce cardiotoxicity with significant increase in serum cardiac enzymes, heart weight, tissue malondialdehyde (MDA), tumor necrosis factor alpha (TNFα), nuclear factor kappa B (NFκB), toll like receptor2 (TLR2), interleukin 6 (IL6) and caspase3 immunoexpression with abnormal histopathological changes. In addition, Cd significantly decreased the level of heme oxygenase1 (HO1), nuclear factor erythroid 2-related factor 2 (Nrf2), signal transducer and activator of transcription (STAT3), reduced glutathione (GSH), glutathione peroxidase (GPx), and total antioxidant capacity (TAC). Co-administration of DAP could ameliorate Cd cardiotoxicity with significant improvement of the biochemical and histopathological changes. We found that DAP had protective properties against Cd induced cardiotoxicity and this may be due to its anti-oxidant, anti-inflammatory, anti-apoptotic properties and modulation of IL6/STAT3 and TLR2/TNFα-signaling pathways.

Renal Tubular Handling of Glucose and Fructose in Health and Disease

The proximal tubule of the kidney is programmed to reabsorb all filtered glucose and fructose. Glucose is taken up by apical sodium-glucose cotransporters SGLT2 and SGLT1 whereas SGLT5 and potentially SGLT4 and GLUT5 have been implicated in apical fructose uptake. The glucose taken up by the proximal tubule is typically not metabolized but leaves via the basolateral facilitative glucose transporter GLUT2 and is returned to the systemic circulation or used as an energy source by distal tubular segments after basolateral uptake via GLUT1. The proximal tubule generates new glucose in metabolic acidosis and the postabsorptive phase, and fructose serves as an important substrate. In fact, under physiological conditions and intake, fructose taken up by proximal tubules is primarily utilized for gluconeogenesis. In the diabetic kidney, glucose is retained and gluconeogenesis enhanced, the latter in part driven by fructose. This is maladaptive as it sustains hyperglycemia. Moreover, renal glucose retention is coupled to sodium retention through SGLT2 and SGLT1, which induces secondary deleterious effects. SGLT2 inhibitors are new anti-hyperglycemic drugs that can protect the kidneys and heart from failing independent of kidney function and diabetes. Dietary excess of fructose also induces tubular injury. This can be magnified by kidney formation of fructose under pathological conditions. Fructose metabolism is linked to urate formation, which partially accounts for fructose-induced tubular injury, inflammation, and hemodynamic alterations. Fructose metabolism favors glycolysis over mitochondrial respiration as urate suppresses aconitase in the tricarboxylic acid cycle, and has been linked to potentially detrimental aerobic glycolysis (Warburg effect). © 2022 American Physiological Society. Compr Physiol 12:2995-3044, 2022.

The combination of dapagliflozin and statins ameliorates renal injury through attenuating the activation of inflammasome-mediated autophagy in insulin-resistant rats

Long-term use of a high-fat diet with high-fructose (HFF) intake could promote insulin resistance and induce lipid accumulation leading to kidney injury possibly via impairment of the autophagy process and enhancement of the inflammasome pathway. We investigated whether dapagliflozin as a monotherapy or combined with atorvastatin could restore kidney autophagy impairment and reduce inflammasome activation associated with kidney injury induced by HFF consumption. Male Wistar rats were given an HFF for 16 weeks and then treated with dapagliflozin with or without atorvastatin for 4 weeks. Impaired glucose tolerance, dyslipidemia, renal lipid accumulation along with impaired renal autophagy and activated inflammasome pathway promoted renal injury were exhibited in HFF rats. Dapagliflozin with or without atorvastatin treatment could partially restore disrupted metabolic parameters and reduce kidney injury. In particular, the combination treatment group showed significant amelioration of inflammasome activation and autophagy impairment. In conclusion, the combination therapy of dapagliflozin and atorvastatin has a positive effect on renal injury associated with autophagy and inflammasome activation induced by HFF in insulin-resistant rats. This study is the first report demonstrating the underlying mechanism associated with a combination treatment of dapagliflozin and atorvastatin on autophagy and inflammasome pathways in an insulin-resistant condition. Therefore, dapagliflozin in combination with atorvastatin may be a further preventive or therapeutic strategy for chronic kidney disease in an insulin-resistant or diabetic condition.

Empagliflozin Reduces Renal Hyperfiltration in Response to Uninephrectomy, but Is Not Nephroprotective in UNx/DOCA/Salt Mouse Models

Large-scale clinical outcome studies demonstrated the efficacy of SGLT2 inhibitors in patients with type II diabetes. Besides their therapeutic efficacy in diabetes, significant renoprotection was observed in non-diabetic patients with chronic kidney disease (CKD), suggesting the existence of glucose-independent beneficial effects of SGLT2 inhibitors. However, the relevant mechanisms by which SGLT2 inhibition delays the progression of renal injury are still largely unknown and speculative. Previous studies showed that SGLT2 inhibitors reduce diabetic hyperfiltration, which is likely a key element in renoprotection. In line with this hypothesis, this study aimed to investigate the nephroprotective effects of the SGLT2 inhibitor empagliflozin (EMPA) in different mouse models with non-diabetic hyperfiltration and progressing CKD to identify the underlying diabetes-independent cellular mechanisms. Non-diabetic hyperfiltration was induced by unilateral nephrectomy (UNx). Since UNx alone does not result in renal damage, renal disease models with varying degrees of glomerular damage and albuminuria were generated by combining UNx with high NaCl diets ± deoxycorticosterone acetate (DOCA) in different mouse strains with and without genetic predisposition for glomerular injury. Renal parameters (GFR, albuminuria, urine volume) were monitored for 4–6 weeks. Application of EMPA via the drinking water resulted in sufficient EMPA plasma concentration and caused glucosuria, diuresis and in some models renal hypertrophy. EMPA had no effect on GFR in untreated wildtype animals, but significantly reduced hyperfiltration after UNx by 36%. In contrast, EMPA did not reduce UNx induced hyperfiltration in any of our kidney disease models, regardless of their degree of glomerular damage caused by DOCA/salt treatment. Consistent with the lack of reduction in glomerular hyperfiltration, EMPA-treated animals developed albuminuria and renal fibrosis to a similar extent as H₂O control animals. Taken together, the data clearly indicate that blockade of SGLT2 has the potential to reduce non-diabetic hyperfiltration in otherwise untreated mice. However, no effects on hyperfiltration or progression of renal injury were observed in hypervolemic kidney disease models, suggesting that high salt intake and extracellular volume might attenuate the protective effects of SGLT2 blockers.

Glucose Metabolism in Acute Kidney Injury and Kidney Repair

The kidneys play an indispensable role in glucose homeostasis via glucose reabsorption, production, and utilization. Conversely, aberrant glucose metabolism is involved in the onset, progression, and prognosis of kidney diseases, including acute kidney injury (AKI). In this review, we describe the regulation of glucose homeostasis and related molecular factors in kidneys under normal physiological conditions. Furthermore, we summarize recent investigations about the relationship between glucose metabolism and different types of AKI. We also analyze the involvement of glucose metabolism in kidney repair after injury, including renal fibrosis. Further research on glucose metabolism in kidney injury and repair may lead to the identification of novel therapeutic targets for the prevention and treatment of kidney diseases.

Pomegranate extract ameliorates renal ischemia/reperfusion injury in rats via suppressing NF-κB pathway

Inflammation and oxidative stress are the major pathways involved in ischemia-reperfusion (I/R)-induced renal injury. This study was designed to evaluate the potential effect of pomegranate against I/R-induced renal injury. I/R injury was induced in nephrectomized rats by unilateral occlusion of the left renal pedicle for 45 min followed by 24 h of perfusion. Pomegranate succeeded to decrease serum levels of creatinine, potassium, and urea nitrogen, along with increasing creatinine clearance. Pomegranate also decreased I/R-induced changes in histopathological examination. Pomegranate attenuated the renal inflammatory response reflected by the suppression of nuclear factor κB p65 DNA binding activity, the upregulation of inhibitory protein kappa B-alpha mRNA expression, the downregulation of mRNA and protein expression of tumor necrosis factor α, in addition to the reduced myeloperoxidase activity and mRNA expression. Additionally, pomegranate attenuated oxidative stress likely through the modulation of lipid peroxidation and antioxidant levels reflected by the decreased MDA content and the increased glutathione level and superoxide dismutase activity. Results confirm the potential protective effect of pomegranate against I/R-induced renal injury through its anti-inflammatory and anti-oxidant effects mediated through the upregulation of inhibitory protein kappa B-alpha, the inhibition of NF-κB activity, and the associated TNF-α release, neutrophil infiltration, and oxidative stress.

Dapagliflozin protects H9c2 cells against injury induced by lipopolysaccharide via suppression of CX3CL1/CX3CR1 axis and NF-κB activity

BACKGROUND

Dapagliflozin, a selective Sodium-glucose cotransporter-2 (SGLT2) inhibitor, has been shown to play a key role in the control and management of the metabolic and cardiac disease.

OBJECTIVE

The current study aims to address the effects of dapagliflozin on the expression of fractalkine (FKN), known as CX3CL1, and its receptors CX3CR1, Nuclear factor-kappa B(NF-κB) p65 activity, Reactive oxygen species (ROS), and inflammation in LPS-treated H9c2 cell line.

METHODS

H9c2 cells were cultured with lipopolysaccharide (LPS) to establish a model of LPS-induced damage and then subsequently were treated with dapagliflozin for 72 h. Our work included measurement of cell viability (MTT), Malondialdehyde (MDA), intracellular ROS, tumor necrosis factor-α (TNF-α), NF-κB activity, and expression CX3CL1/CX3CR1.

RESULTS

The results showed that LPS-induced reduction of cell viability was successfully rescued by dapagliflozin treatment. The cellular levels of MDA, ROS, and TNF-α, as an indication of cellular oxidative stress and inflammation, were significantly elevated in H9c2 cells compared to the control group. Furthermore, dapagliflozin ameliorated inflammation and oxidative stress through the modulation of the levels of MDA, TNF-α, and ROS. Correspondingly, dapagliflozin reduced the expression of CX3CL1/CX3CR1, NF-κB p65 DNA binding activity and it also attenuated nuclear acetylated NF-κB p65 in LPS-induced injury in H9c2 cells compared to untreated cells.

CONCLUSION

These findings shed light on the novel pharmacological potential of dapagliflozin in the alleviation of LPS-induced CX3CL1/CX3CR1-mediated injury in inflammatory conditions such as sepsis-induced cardiomyopathy.

Sodium-glucose cotransporter-2 Inhibitors in Heart Failure: An Updated Systematic Review and Meta-analysis of 13 Randomized Clinical Trials Including 14,618 Patients With Heart Failure

Sodium-glucose cotransporter-2 (SGLT-2) inhibitors showed benefit in patients with heart failure. In this updated meta-analysis, we evaluate the therapeutic efficacy and safety of SGLT-2 inhibitors in patients with heart failure. Different electronic databases were searched to find relevant articles. RevMan 5.4 was used for pooling data using a random/fixed-effects model, complemented by several sensitivity and subgroup analyses. A total of 13 randomized clinical trials including 14,618 patients with heart failure were included in analysis among 6797 studies screened. The overall mortality rate was 12.45% in the SGLT-2 group and 14.67% in the placebo group with 18% lower odds of overall mortality [odds ratio (OR), 0.82; confidence interval (CI), 0.75-0.91] in the SGLT-2 group. Odds of cardiovascular mortality was 18% lower (OR, 0.82; CI, 0.74-0.92) in the SGLT-2 group. The odds of hospitalization for heart failure (HHF) was 38% lower during the study period (OR, 0.62; CI, 0.56-0.68) in the SGLT-2 group. In addition, a benefit was seen for composite outcome HHF or mortality and considering subgrouping based on diabetes status, gender, and age groups. Although genital infection was significantly higher in the SGLT-2 group, the occurrence of severe adverse events, hypoglycemia, urinary tract infection, bone fracture, volume depletion, and other renal events did not differ between the 2 groups. Thus, SGLT-2 inhibitors improved cardiovascular outcomes among patients with heart failure with no significant difference in adverse events. Clinical benefit was comparable in diabetic and nondiabetic individuals, males and females, people in younger and older age groups with underlying heart failure, and HF with reduced ejection fraction.

Protective effect of dapagliflozin against cyclosporine A-induced nephrotoxicity

This study aimed to reveal the possible protective effect of dapagliflozin (DAPA) against acute kidney damage due to cyclosporine A (CsA). Thirty-two mice with an eight-week-old Balb\c albino strain were divided into four groups: control group, CsA group, DAPA group, and CsA + DAPA group. On day 9 of treatment, the animals were decapitated, and bilateral nephrectomy was performed. Oxidative stress and apoptosis were evaluated with caspase-3 activity, total oxidant status (TOS), total antioxidant status (TAS), malondialdehyde (MDA), myeloperoxidase (MPO), B-cell lymphoma-2 (Bcl-2), and Bcl-2-associated X protein (Bax) in the right kidney resection material. The left kidney resection material was evaluated histopathologically. CsA increased caspase-3 activity, Bax, TOS, MDA, TAS, and MPO levels, and the administration of DAPA with CsA significantly reduced this increase in levels (p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, and p < 0.001, respectively). CsA decreased Bcl-2 levels, and administration of CsA + DAPA significantly increased Bcl-2 levels compared with only CsA administration (p < 0.001). Additionally, administration of DAPA significantly reduced the histopathological findings (parenchymal inflammation, hyaline cast formation, vacuolization, and lysis of renal tubular cells) caused by CsA. DAPA reduces oxidative stress, apoptosis, and histopathological damage caused by CsA in renal tissue.

Sirtuin 5 depletion impairs mitochondrial function in human proximal tubular epithelial cells

Ischemia is a major cause of kidney damage. Proximal tubular epithelial cells (PTECs) are highly susceptible to ischemic insults that frequently cause acute kidney injury (AKI), a potentially life-threatening condition with high mortality. Accumulating evidence has identified altered mitochondrial function as a central pathologic feature of AKI. The mitochondrial NAD⁺-dependent enzyme sirtuin 5 (SIRT5) is a key regulator of mitochondrial form and function, but its role in ischemic renal injury (IRI) is unknown. SIRT5 expression was increased in murine PTECs after IRI in vivo and in human PTECs (hPTECs) exposed to an oxygen/nutrient deprivation (OND) model of IRI in vitro. SIRT5-depletion impaired ATP production, reduced mitochondrial membrane potential, and provoked mitochondrial fragmentation in hPTECs. Moreover, SIRT5 RNAi exacerbated OND-induced mitochondrial bioenergetic dysfunction and swelling, and increased degradation by mitophagy. These findings suggest SIRT5 is required for normal mitochondrial function in hPTECs and indicate a potentially important role for the enzyme in the regulation of mitochondrial biology in ischemia.

Sodium-glucose cotransporter-2 inhibitors and non-steroidal mineralocorticoid receptor antagonists: Ushering in a new era of nephroprotection beyond renin-angiotensin system blockade

The therapeutic options for preventing or slowing the progression of chronic kidney disease (CKD) have been thus far limited. While angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs) are, without a doubt, safe and effective drugs, a significant proportion of patients with CKD still progress to end-stage kidney disease. After decades of negative trials, nephrologists have finally found cause for optimism with the introduction of sodium-glucose cotransporter-2 (SGLT2) inhibitors and non-steroidal mineralocorticoid receptor antagonists (MRAs). Recent trials such as EMPA-REG OUTCOME and CREDENCE have provided evidence of the renal benefits of SGLT2 inhibitors, which have now found widespread acceptance as first-line agents for diabetic CKD, in addition to ACEi/ARBs. Considering results from the DAPA-CKD study, it is expected that their use will soon be expanded to other causes of albuminuric CKD as well, although confirmation from further trials, such as the EMPA-KIDNEY study is awaited. Likewise, although the role of mineralocorticoid receptor overactivation in CKD progression has been known for decades, it is only now with the FIDELIO-DKD study that we have evidence of benefits of MRAs on hard renal endpoints, specifically in patients with diabetic CKD. While further research is ongoing, given the evidence of synergism between the three drug classes, it is foreseeable that a combination of two or more of these drugs may soon become the standard of care for CKD, regardless of underlying aetiology. This review describes pathophysiologic mechanisms, current evidence and future perspectives on the use of SGLT2 inhibitors and novel MRAs in CKD.