Changes in plasma and urine metabolites associated with empagliflozin in patients with type 1 diabetes

Female Protection Against Diabetic Kidney Disease Is Regulated by Kidney-Specific AMPK Activity

Reduced kidney AMPK activity is associated with nutrient stress-induced chronic kidney disease (CKD) in male mice. In contrast, female mice resist nutrient stress-induced CKD. The role of kidney AMPK in sex-related organ protection against nutrient stress and metabolite changes was evaluated in diabetic kidney tubule-specific AMPKγ2KO (KTAMPKγ2ΚΟ) male and female mice. In wild-type (WT) males, diabetes increased albuminuria, urinary kidney injury molecule-1, hypertension, kidney p70S6K phosphorylation, and kidney matrix accumulation; these features were not exacerbated with KTAMPKγ2ΚΟ. Whereas WT females had protection against diabetes-induced kidney injury, KTAMPKγ2ΚΟ led to loss of female protection against kidney disease. The hormone 17β-estradiol ameliorated high glucose-induced AMPK inactivation, p70S6K phosphorylation, and matrix protein accumulation in kidney tubule cells. The mechanism for female protection against diabetes-induced kidney injury is likely via an estrogen-AMPK pathway, as inhibition of AMPK led to loss of estrogen protection to glucose-induced mTORC1 activation and matrix production. RNA sequencing and metabolomic analysis identified a decrease in the degradation pathway of phenylalanine and tyrosine resulting in increased urinary phenylalanine and tyrosine levels in females. The metabolite levels correlated with loss of female protection. The findings provide new insights to explain evolutionary advantages to females during states of nutrient challenges.

ARTICLE HIGHLIGHTS

Quinolinic acid links kidney injury to brain toxicity

Kidney dysfunction often leads to neurological impairment, yet the complex kidney-brain relationship remains elusive. We employed spatial and bulk metabolomics to investigate a mouse model of rapid kidney failure induced by mouse double minute 2 ( Mdm2) conditional deletion in the kidney tubules to interrogate kidney and brain metabolism. Pathway enrichment analysis of focused plasma metabolomics panel pinpointed tryptophan metabolism as the most altered pathway with kidney failure. Spatial metabolomics showed toxic tryptophan metabolites in the kidneys and brains, revealing a novel connection between advanced kidney disease and accelerated kynurenine degradation. In particular, the excitotoxic metabolite quinolinic acid was localized in ependymal cells adjacent to the ventricle in the setting of kidney failure. These findings were associated with brain inflammation and cell death. A separate mouse model of acute kidney injury also had an increase in circulating toxic tryptophan metabolites along with altered brain inflammation. Patients with advanced CKD similarly demonstrated elevated plasma kynurenine metabolites and quinolinic acid was uniquely correlated with fatigue and reduced quality of life in humans. Overall, our study identifies the kynurenine pathway as a bridge between kidney decline, systemic inflammation, and brain toxicity, offering potential avenues for diagnosis and treatment of neurological issues in kidney disease.

Cardiovascular benefits of SGLT2 inhibitors and GLP-1 receptor agonists through effects on mitochondrial function and oxidative stress

Overloaded glucose levels in several metabolic diseases such as type 2 diabetes (T2D) can lead to mitochondrial dysfunction and enhanced production of reactive oxygen species (ROS). Oxidative stress and altered mitochondrial homeostasis, particularly in the cardiovascular system, contribute to the development of chronic comorbidities of diabetes. Diabetes-associated hyperglycemia and dyslipidemia can directly damage vascular vessels and lead to coronary artery disease or stroke, and indirectly damage other organs and lead to kidney dysfunction, known as diabetic nephropathy. The new diabetes treatments include Na+-glucose cotransporter 2 inhibitors (iSGLT2) and glucagon-like 1 peptide receptor agonists (GLP-1RA), among others. The iSGLT2 are oral anti-diabetic drugs, whereas GLP-1RA are preferably administered through subcutaneous injection, even though GLP-1RA oral formulations have recently become available. Both therapies are known to improve both carbohydrate and lipid metabolism, as well as to improve cardiovascular and cardiorenal outcomes in diabetic patients. In this review, we present an overview of current knowledge on the relationship between oxidative stress, mitochondrial dysfunction, and cardiovascular therapeutic benefits of iSGLT2 and GLP-1RA. We explore the benefits, limits and common features of the treatments and remark how both are an interesting target in the prevention of obesity, T2D and cardiovascular diseases, and emphasize the lack of a complete understanding of the underlying mechanism of action.

Interactive Effects of Empagliflozin and Hyperglycemia on Urinary Amino Acids in Individuals With Type 1 Diabetes

Optimizing energy use in the kidney is critical for normal kidney function. Here, we investigate the effect of hyperglycemia and sodium-glucose cotransporter 2 (SGLT2) inhibition on urinary amino acid excretion in individuals with type 1 diabetes (T1D). The open-label ATIRMA trial assessed the impact of 8 weeks of 25 mg empagliflozin orally once per day in 40 normotensive normoalbuminuric young adults with T1D. A consecutive 2-day assessment of clamped euglycemia and hyperglycemia was evaluated at baseline and posttreatment visits. Principal component analysis was performed on urinary amino acids grouped into representative metabolic pathways using MetaboAnalyst. At baseline, acute hyperglycemia was associated with changes in 25 of the 33 urinary amino acids or their metabolites. The most significant amino acid metabolites affected by acute hyperglycemia were 3-hydroxykynurenine, serotonin, glycyl-histidine, and nicotinic acid. The changes in amino acid metabolites were reflected by the induction of four biosynthetic pathways: aminoacyl-tRNA; valine, leucine, and isoleucine; arginine; and phenylalanine, tyrosine, and tryptophan. In acute hyperglycemia, empagliflozin significantly attenuated the increases in aminoacyl-tRNA biosynthesis and valine, leucine, and isoleucine biosynthesis. Our findings using amino acid metabolomics indicate that hyperglycemia stimulates biosynthetic pathways in T1D. SGLT2 inhibition may attenuate the increase in biosynthetic pathways to optimize kidney energy metabolism.

ARTICLE HIGHLIGHTS

SGLT2 inhibitor improves kidney function and morphology by regulating renal metabolism in mice with diabetic kidney disease

BACKGROUND

Diabetic kidney disease (DKD) is a secondary complication of diabetes mellitus and a leading cause of chronic kidney disease.

AIM

To investigate the impact of long-term canagliflozin treatment on DKD and elucidate its underlying mechanism.

METHODS

DKD model was established using high-fat diet and streptozotocin in male C57BL/6J mice (n = 30). Mice were divided into five groups and treated for 12 weeks. 1) normal control mice, 2) DKD model, 3) mice treated low-dose of canagliflozin, 4) high-dose of canagliflozin and 5) β-hydroxybutyrate. Mice kidney morphology and function were evaluated, and a metabolomics analysis was performed.

RESULTS

Canagliflozin treatment reduced blood creatinine and urine nitrogen levels and improved systemic insulin sensitivity and glucose tolerance in diabetic mice. Additionally, a decrease in histological lesions including collagen and lipid deposition in the kidneys was observed. β-hydroxybutyrate treatment did not yield a comparable outcome. The metabolomics analysis revealed that canagliflozin induced alterations in amino acid metabolism profiles in the renal tissue of diabetic mice.

CONCLUSION

Canagliflozin protects the kidneys of diabetic mice by increasing the levels of essential amino acids, promoting mitochondrial homeostasis, mitigating oxidative stress, and stimulating the amino acid-dependent tricarboxylic acid cycle.

Ketone production and excretion even during mild hyperglycemia and the impact of sodium-glucose co-transporter inhibition in type 1 diabetes

AIMS

We aimed to determine if ketone production and excretion are increased even at mild fasting hyperglycemia in type 1 diabetes (T1D) and if these are modified by ketoacidosis risk factors, including sodium-glucose co-transporter inhibition (SGLTi) and female sex.

METHODS

In secondary analysis of an 8-week single-arm open-label trial of empagliflozin (NCT01392560) we evaluated ketone concentrations during extended fasting and clamped euglycemia (4-6 mmol/L) and mild hyperglycemia (9-11 mmol/L) prior to and after treatment. Plasma and urine beta-hydroxybutyrate (BHB) concentrations and fractional excretion were analyzed by metabolomic analysis.

RESULTS

Forty participants (50 % female), aged 24 ± 5 years, HbA1c 8.0 ± 0.9 % (64 ± 0.08 mmol/mol) with T1D duration of 17.5 ± 7 years, were studied. Increased BHB production even during mild hyperglycemia (median urine 6.3[3.5-13.6] vs. 3.5[2.2-7.0] µmol/mmol creatinine during euglycemia, p < 0.001) was compensated by increased fractional excretion (0.9 % [0.3-1.6] vs. 0.4 % [0.2-0.9], p < 0.001). SGLTi increased production and attenuated the increased BHB fractional excretion (decreased to 0.3 % during mild hyperglycemia, p < 0.001), resulting in higher plasma concentrations (increased to 0.21 [0.05-0.40] mmol/L, p < 0.001), particularly in females (interaction p < 0.001).

CONCLUSIONS

Even mild hyperglycemia is associated with greater ketone production, compensated by urinary excretion, in T1D. However, SGLTi exaggerates production and partially reduces compensatory excretion, particularly in women.

Sodium-dependent glucose transporter 2 inhibitor alleviates renal lipid deposition and improves renal oxygenation levels in newly diagnosed type 2 diabetes mellitus patients: a randomized controlled trial

BACKGROUND

Sodium-dependent glucose transporter 2 inhibitor (SGLT2i) has the advantages of effectively lowering blood glucose levels and improving renal outcomes in diabetic patients. This study evaluated the effect of canagliflozin on intrarenal lipid content and oxygenation in newly diagnosed type 2 diabetes mellitus (T2DM) patients.

METHODS

A total of 64 newly diagnosed T2DM patients with normal renal function were randomly divided into canagliflozin (n = 33) and glimepiride control (n = 31) groups. All patients underwent functional magnetic resonance imaging (fMRI) scanning to assay patients' intrarenal lipid content and oxygenation level before and after 24 weeks of treatment. Furthermore, the relationship between body mass index and intrarenal lipid content in T2DM patients was analyzed and the correlation between changes in intrarenal lipid content and improvements in renal hypoxia was further assessed.

RESULTS

The canagliflozin group had a greater decrease in body weight and blood uric acid level than the glimepiride group (all P < 0.05). The intrarenal lipid content could be significantly reduced after canagliflozin treatment for 24 weeks. The R2* values, a parameter for quantifying the oxygen content in tissues and is inversely related to the oxygen content, of the renal cortex and medulla in the canagliflozin group decreased from the baseline by 6.40% (P < 0.01) and 12.09% (P = 0.000007), respectively. In addition, the degree of reduction of fat fraction (ΔFF) in the kidneys of the canagliflozin group was correlated with the degree of improvement of oxygenation level (ΔR2*) in the renal cortex (r = 0.422, P = 0.014).

CONCLUSIONS

The early renal protective effect of SGLT2i in newly diagnosed T2DM patients may be partly attributed to the amelioration of renal hypoxia via the alleviation of ectopic lipid deposition in the kidneys.

TRIAL REGISTRATION

Chu Hsien-I Memorial Hospital of Tianjin Medical University (ChiCTR2000037951).

Metabolomic analysis of serum samples from a clinical study on ipragliflozin and metformin treatment in Japanese patients with type 2 diabetes: Exploring human metabolites associated with visceral fat reduction

STUDY OBJECTIVE

The effects of the sodium-dependent glucose transporter-2 inhibitor ipragliflozin were compared with metformin in a previous study, which revealed that ipragliflozin reduced visceral fat content by 12%; however, the underlying mechanism was unclear. Therefore, this sub-analysis aimed to compare metabolomic changes associated with ipragliflozin and metformin that may contribute to their biological effects.

DESIGN

A sub-analysis of a randomized controlled study.

SETTING

Chiba University Hospital and ten hospitals in Japan.

PATIENTS

Fifteen patients with type 2 diabetes in the ipragliflozin group and 15 patients with type 2 diabetes in the metformin group with matching characteristics, such as age, sex, baseline A1C, baseline visceral fat area, smoking status, and concomitant medication.

INTERVENTIONS

Ipragliflozin 50 mg or metformin 1000 mg daily.

MEASUREMENTS

The clinical data were reanalyzed, and metabolomic analysis of serum samples collected before and 24 weeks after drug administration was performed using capillary electrophoresis time-of-flight mass spectrometry.

MAIN RESULTS

The reduction in the mean visceral fat area after 24 weeks of treatment was significantly larger (p = 0.002) in the ipragliflozin group (-19.8%) than in the metformin group (-2.5%), as were the subcutaneous fat area and body weight. The A1C and blood glucose levels decreased in both groups. Glutamic pyruvic oxaloacetic transaminase, γ-glutamyl transferase, uric acid, and triglyceride levels decreased in the ipragliflozin group. Low-density lipoprotein cholesterol levels decreased in the metformin group. After ipragliflozin administration, N2-phenylacetylglutamine, inosine, guanosine, and 1-methyladenosine levels increased, whereas galactosamine, glucosamine, 11-aminoundecanoic acid, morpholine, and choline levels decreased. After metformin administration, metformin, hypotaurine, methionine, methyl-2-oxovaleric acid, 3-nitrotyrosine, and cyclohexylamine levels increased, whereas citrulline, octanoic acid, indole-3-acetaldehyde, and hexanoic acid levels decreased.

CONCLUSIONS

Metabolites that may affect visceral fat reduction were detected in the ipragliflozin group. Studies are required to further elucidate the underlying mechanisms.

SGLT2 Inhibitors in the Management of Type 1 Diabetes (T1D): An Update on Current Evidence and Recommendations

SGLT2i (sodium glucose transporter type 2 inhibitors) are pharmacological agents that act by inhibiting the SGLT2, by reducing the renal plasma glucose threshold and inducing glycosuria, resulting in a blood glucose lowering effect. In recent years, studies demonstrating some additional positive effects of SGLT2i also in the treatment of T1D have increased progressively. The SGLT2i dapagliflozin and sotagliflozin have been temporarily licensed for use by the European Medical Agency (EMA) as an adjunct to insulin therapy in adults with T1D with a body mass index of 27 kg/m2 or higher. However, in the meantime, the US Food and Drug Administration (FDA) Endocrinologic and Metabolic Drugs Advisory Committee was divided, citing concerns about the main side effects of SGLT2i, especially diabetic ketoacidosis (DKA). The aim of this manuscript was to conduct an update on current evidence and recommendations of the reported use of SGLT2i in the treatment of T1D in humans. Preclinical studies, clinical trial and real world data suggest benefits in glycaemia control and nefro-cardiovascular protection, even though several studies have documented an important increase in the risk of DKA, a serious and life-threatening adverse event of these agents. SGLT2i potentially addresses some of the unmet needs associated with T1D by improving glycaemic control with weight loss and without increasing hypoglycemia, by reducing glycaemic variability. However, due to side effects, EMA recommendation for SGLT2 use on T1D was withdrawn. Further studies will be needed to determine the safety of this therapy in T1D and to define the type of patient who can benefit most from these medications.

Endogenous adenine mediates kidney injury in diabetic models and predicts diabetic kidney disease in patients

Diabetic kidney disease (DKD) can lead to end-stage kidney disease (ESKD) and mortality; however, few mechanistic biomarkers are available for high-risk patients, especially those without macroalbuminuria. Urine from participants with diabetes from the Chronic Renal Insufficiency Cohort (CRIC) study, the Singapore Study of Macro-angiopathy and Micro-vascular Reactivity in Type 2 Diabetes (SMART2D), and the American Indian Study determined whether urine adenine/creatinine ratio (UAdCR) could be a mechanistic biomarker for ESKD. ESKD and mortality were associated with the highest UAdCR tertile in the CRIC study and SMART2D. ESKD was associated with the highest UAdCR tertile in patients without macroalbuminuria in the CRIC study, SMART2D, and the American Indian study. Empagliflozin lowered UAdCR in nonmacroalbuminuric participants. Spatial metabolomics localized adenine to kidney pathology, and single-cell transcriptomics identified ribonucleoprotein biogenesis as a top pathway in proximal tubules of patients without macroalbuminuria, implicating mTOR. Adenine stimulated matrix in tubular cells via mTOR and stimulated mTOR in mouse kidneys. A specific inhibitor of adenine production was found to reduce kidney hypertrophy and kidney injury in diabetic mice. We propose that endogenous adenine may be a causative factor in DKD.

SGLT2 Inhibitors in the Treatment of Diabetic Kidney Disease: More than Just Glucose Regulation

Diabetic kidney disease (DKD) is a severe and common complication and affects a quarter of patients with type 2 diabetes mellitus (T2DM). Oxidative stress and inflammation related to hyperglycemia are interlinked and contribute to the occurrence of DKD. It was shown that sodium-glucose cotransporter-2 (SGLT2) inhibitors, a novel yet already widely used therapy, may prevent the development of DKD and alter its natural progression. SGLT2 inhibitors induce systemic and glomerular hemodynamic changes, provide metabolic advantages, and reduce inflammatory and oxidative stress pathways. In T2DM patients, regardless of cardiovascular diseases, SGLT2 inhibitors may reduce albuminuria, progression of DKD, and doubling of serum creatinine levels, thus lowering the need for kidney replacement therapy by over 40%. The molecular mechanisms behind these beneficial effects of SGLT2 inhibitors extend beyond their glucose-lowering effects. The emerging studies are trying to explain these mechanisms at the genetic, epigenetic, transcriptomic, and proteomic levels.

Role of endogenous adenine in kidney failure and mortality with diabetes

Diabetic kidney disease (DKD) can lead to end-stage kidney disease (ESKD) and mortality, however, few mechanistic biomarkers are available for high risk patients, especially those without macroalbuminuria. Urine from participants with diabetes from Chronic Renal Insufficiency Cohort (CRIC), Singapore Study of Macro-Angiopathy and Reactivity in Type 2 Diabetes (SMART2D), and the Pima Indian Study determined if urine adenine/creatinine ratio (UAdCR) could be a mechanistic biomarker for ESKD. ESKD and mortality were associated with the highest UAdCR tertile in CRIC (HR 1.57, 1.18, 2.10) and SMART2D (HR 1.77, 1.00, 3.12). ESKD was associated with the highest UAdCR tertile in patients without macroalbuminuria in CRIC (HR 2.36, 1.26, 4.39), SMART2D (HR 2.39, 1.08, 5.29), and Pima Indian study (HR 4.57, CI 1.37-13.34). Empagliflozin lowered UAdCR in non-macroalbuminuric participants. Spatial metabolomics localized adenine to kidney pathology and transcriptomics identified ribonucleoprotein biogenesis as a top pathway in proximal tubules of patients without macroalbuminuria, implicating mammalian target of rapamycin (mTOR). Adenine stimulated matrix in tubular cells via mTOR and stimulated mTOR in mouse kidneys. A specific inhibitor of adenine production was found to reduce kidney hypertrophy and kidney injury in diabetic mice. We propose that endogenous adenine may be a causative factor in DKD.

Mapping the metabolic reprogramming induced by sodium-glucose cotransporter 2 inhibition

Diabetes is associated with increased risk for kidney disease, heart failure, and mortality. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) prevent these adverse outcomes; however, the mechanisms involved are not clear. We generated a roadmap of the metabolic alterations that occur in different organs in diabetes and in response to SGLT2i. In vivo metabolic labeling with 13C-glucose in normoglycemic and diabetic mice treated with or without dapagliflozin, followed by metabolomics and metabolic flux analyses, showed that, in diabetes, glycolysis and glucose oxidation are impaired in the kidney, liver, and heart. Treatment with dapagliflozin failed to rescue glycolysis. SGLT2 inhibition increased glucose oxidation in all organs; in the kidney, this was associated with modulation of the redox state. Diabetes was associated with altered methionine cycle metabolism, evident by decreased betaine and methionine levels, whereas treatment with SGLT2i increased hepatic betaine along with decreased homocysteine levels. mTORC1 activity was inhibited by SGLT2i along with stimulation of AMPK in both normoglycemic and diabetic animals, possibly explaining the protective effects against kidney, liver, and heart diseases. Collectively, our findings suggest that SGLT2i induces metabolic reprogramming orchestrated by AMPK-mTORC1 signaling with common and distinct effects in various tissues, with implications for diabetes and aging.

SGLT2 inhibition in heart failure with reduced or preserved ejection fraction: Finding the right patients to treat

Sodium-glucose transport inhibitors (SGLT2i) are effective in heart failure (HF) with ejection fraction (EF) <40% (referred to as HF with reduced EF - HFrEF) and left ventricular EF (LVEF) >40%. Current evidence suggests that SGLT2i should be initiated across a large spectrum of EFs and renal function in patients with HF and with and without diabetes. We reviewed the benefits of SGLT2i in the entire spectrum of HF and provided some clues that may guide physicians in their strategy of initiating and maintaining SGLT2i (with or without SGLT1i effect) therapy. Taken together, the evidence thus far arises from an array of trials performed in different settings (acute/chronic), risk categories, and phenotypes of HF (HFrEF/HFpEF), and in addition to the most common HF therapies, supports the homogenous effect of SGLT2i across a large spectrum of patients with HF. SGLT2i appear to be effective and well-tolerated drugs in the majority of clinical HF scenarios, regardless of LVEF, estimated glomerular filtration rate, diabetic status or the level of the acuteness of the clinical setting. Therefore, most patients with HF should be treated with SGLT2i. However, in the face of the therapeutic inertia that has been observed in HF over the past decades, the actual implementation of SGLT2i in routine practice remains the most significant challenge.

SGLT2 Inhibitors: The Sweet Success for Kidneys

Sodium-glucose cotransporter-2 inhibitors (SGLT2 inhibitors) were originally developed as antidiabetic agents, with cardiovascular (CV) outcome trials demonstrating improved CV outcomes in patients with type 2 diabetes mellitus (T2D). Secondary analyses of CV outcome trials and later dedicated kidney outcome trials consistently reported improved kidney-related outcomes independent of T2D status and across a range of kidney function and albuminuria. Importantly, SGLT2 inhibitors are generally safe and well tolerated, with clinical trials and real-world analyses demonstrating a decrease in the risk of acute kidney injury. The kidney protective effects of SGLT2 inhibitors generally extend across different members of the class, possibly on the basis of hemodynamic, metabolic, anti-inflammatory, and antifibrotic mechanisms. In this review, we summarize the effects of SGLT2 inhibitors on kidney outcomes in diverse patient populations.

Insulin resistance in Alzheimer's disease: The genetics and metabolomics links

Alzheimer's disease (AD) is a neurodegenerative disease with significant socioeconomic burden worldwide. Although genetics and environmental factors play a role, AD is highly associated with insulin resistance (IR) disorders such as metabolic syndrome (MS), obesity, and type two diabetes mellitus (T2DM). These findings highlight a shared pathogenesis. The use of metabolomics as a downstream systems' biology (omics) approach can help to identify these shared metabolic traits and assist in the early identification of at-risk groups and potentially guide therapy. Targeting the shared AD-IR metabolic trait with lifestyle interventions and pharmacological treatments may offer promising AD therapeutic approach. In this narrative review, we reviewed the literature on the AD-IR pathogenic link, the shared genetics and metabolomics biomarkers between AD and IR disorders, as well as the lifestyle interventions and pharmacological treatments which target this pathogenic link.

Empagliflozin activates Wnt/β-catenin to stimulate FUNDC1-dependent mitochondrial quality surveillance against type-3 cardiorenal syndrome

Objectives

Cardiorenal syndrome type-3 (CRS-3) is an abrupt worsening of cardiac function secondary to acute kidney injury. Mitochondrial dysfunction is a key pathological mechanism of CRS-3, and empagliflozin can improve mitochondrial biology by promoting mitophagy. Here, we assessed the effects of empagliflozin on mitochondrial quality surveillance in a mouse model of CRS-3.

Methods

Cardiomyocyte-specific FUNDC1-knockout (FUNDC1^CKO) mice were subjected to CRS-3 prior to assessment of mitochondrial homeostasis in the presence or absence of empagliflozin.

Results

CRS-3 model mice exhibited lower heart function, increased inflammatory responses and exacerbated myocardial oxidative stress than sham-operated controls; however, empagliflozin attenuated these alterations. Empagliflozin stabilized the mitochondrial membrane potential, suppressed mitochondrial reactive oxygen species production, increased mitochondrial respiratory complex activity and restored the oxygen consumption rate in cardiomyocytes from CRS-3 model mice. Empagliflozin also normalized the mitochondrial morphology, mitochondrial dynamics and mitochondrial permeability transition pore opening rate in cardiomyocytes. Cardiomyocyte-specific ablation of FUN14 domain-containing protein 1 (FUNDC1) in mice abolished the protective effects of empagliflozin on mitochondrial homeostasis and myocardial performance. Empagliflozin activated β-catenin and promoted its nuclear retention, thus increasing FUNDC1-induced mitophagy in heart tissues; however, a β-catenin inhibitor reversed these effects.

Conclusions

In summary, empagliflozin activated Wnt/β-catenin to stimulate FUNDC1-dependent mitochondrial quality surveillance, ultimately improving mitochondrial function and cardiac performance during CRS-3. Thus, empagliflozin could be considered for the clinical management of heart function following acute kidney injury.

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Empagliflozin reduces myocardial damage and improves myocardial function after CRS-3.

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Empagliflozin normalizes the mitochondrial structure in cardiomyocytes during CRS-3.

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Empagliflozin attenuates cardiomyocyte mitochondrial dysfunction during CRS-3.

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Empagliflozin activates FUNDC1-dependent mitophagy and preserves mitochondrial integrity in the heart during CRS-3.

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Loss of FUNDC1 abolishes the cardioprotective effects of empagliflozin during CRS-3.

Podocyte Injury in Diabetic Kidney Disease: A Focus on Mitochondrial Dysfunction

Podocytes are a crucial cellular component in maintaining the glomerular filtration barrier, and their injury is the major determinant in the development of albuminuria and diabetic kidney disease (DKD). Podocytes are rich in mitochondria and heavily dependent on them for energy to maintain normal functions. Emerging evidence suggests that mitochondrial dysfunction is a key driver in the pathogenesis of podocyte injury in DKD. Impairment of mitochondrial function results in an energy crisis, oxidative stress, inflammation, and cell death. In this review, we summarize the recent advances in the molecular mechanisms that cause mitochondrial damage and illustrate the impact of mitochondrial injury on podocytes. The related mitochondrial pathways involved in podocyte injury in DKD include mitochondrial dynamics and mitophagy, mitochondrial biogenesis, mitochondrial oxidative phosphorylation and oxidative stress, and mitochondrial protein quality control. Furthermore, we discuss the role of mitochondria-associated membranes (MAMs) formation, which is intimately linked with mitochondrial function in podocytes. Finally, we examine the experimental evidence exploring the targeting of podocyte mitochondrial function for treating DKD and conclude with a discussion of potential directions for future research in the field of mitochondrial dysfunction in podocytes in DKD.

Metabolomics Study Reveals the Alteration of Fatty Acid Oxidation in the Heart of Diabetic Mice by Empagliflozin

Empagliflozin (Empa, SGLT2 inhibitor), is widely used in clinical situation for the management of diabetes. It has beneficial effects in reducing cardiac dysfunction and heart failure. However, rare studies had...