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Girardi ACC, Polidoro JZ, Castro PC, Pio-Abreu A, Noronha IL, Drager LF. Mechanisms of heart failure and chronic kidney disease protection by SGLT2 inhibitors in nondiabetic conditions. Am J Physiol Cell Physiol 2024; 327:C525-C544. [PMID: 38881421 DOI: 10.1152/ajpcell.00143.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 06/11/2024] [Accepted: 06/11/2024] [Indexed: 06/18/2024]
Abstract
Sodium-glucose cotransporter 2 inhibitors (SGLT2is), initially developed for type 2 diabetes (T2D) treatment, have demonstrated significant cardiovascular and renal benefits in heart failure (HF) and chronic kidney disease (CKD), irrespective of T2D. This review provides an analysis of the multifaceted mechanisms underlying the cardiorenal benefits of SGLT2i in HF and CKD outside of the T2D context. Eight major aspects of the protective effects of SGLT2i beyond glycemic control are explored: 1) the impact on renal hemodynamics and tubuloglomerular feedback; 2) the natriuretic effects via proximal tubule Na+/H+ exchanger NHE3 inhibition; 3) the modulation of neurohumoral pathways with evidence of attenuated sympathetic activity; 4) the impact on erythropoiesis, not only in the context of local hypoxia but also systemic inflammation and iron regulation; 5) the uricosuria and mitigation of the hyperuricemic environment in cardiorenal syndromes; 6) the multiorgan metabolic reprogramming including the potential induction of a fasting-like state, improvement in glucose and insulin tolerance, and stimulation of lipolysis and ketogenesis; 7) the vascular endothelial growth factor A (VEGF-A) upregulation and angiogenesis, and 8) the direct cardiac effects. The intricate interplay between renal, neurohumoral, metabolic, and cardiac effects underscores the complexity of SGLT2i actions and provides valuable insights into their therapeutic implications for HF and CKD. Furthermore, this review sets the stage for future research to evaluate the individual contributions of these mechanisms in diverse clinical settings.
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Affiliation(s)
- Adriana C C Girardi
- Laboratório de Genética e Cardiologia Molecular, Faculdade de Medicina, Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Universidade de São Paulo, São Paulo, Brazil
| | - Juliano Z Polidoro
- Laboratório de Genética e Cardiologia Molecular, Faculdade de Medicina, Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Universidade de São Paulo, São Paulo, Brazil
| | - Paulo C Castro
- Laboratório de Genética e Cardiologia Molecular, Faculdade de Medicina, Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Universidade de São Paulo, São Paulo, Brazil
| | - Andrea Pio-Abreu
- Disciplina de Nefrologia, Faculdade de Medicina, Hospital das Clínicas HCFMUSP, Universidade de São Paulo, São Paulo, Brazil
| | - Irene L Noronha
- Disciplina de Nefrologia, Faculdade de Medicina, Hospital das Clínicas HCFMUSP, Universidade de São Paulo, São Paulo, Brazil
| | - Luciano F Drager
- Disciplina de Nefrologia, Faculdade de Medicina, Hospital das Clínicas HCFMUSP, Universidade de São Paulo, São Paulo, Brazil
- Unidade de Hipertensão, Faculdade de Medicina, Instituto do Coração (InCor), Hospital das Clínicas HCFMUSP, Universidade de São Paulo, São Paulo, Brazil
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Sasako T. Exploring mechanisms of insulin action and strategies to treat diabetes. Endocr J 2024; 71:651-660. [PMID: 38811207 DOI: 10.1507/endocrj.ej24-0003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/31/2024] Open
Abstract
Insulin is a hormone that positively regulates anabolism and cell growth, whereas diabetes mellitus is a disease characterized by hyperglycemia associated with impaired insulin action. My colleagues and I have elucidated multifaceted insulin action in various tissues mainly by means of model mice. In the liver, insulin regulates endoplasmic reticulum (ER) stress response during feeding, whereas ER stress 'response failure' contributes to the development of steatohepatitis comorbid with diabetes. Not only the liver but also the proximal tubules of the kidney are important in the regulation of gluconeogenesis, and we revealed that insulin suppresses gluconeogenesis in accordance with absorbed glucose in the latter tissue. In skeletal muscle, another important insulin-targeted tissue, impaired insulin/IGF-1 signaling leads not only to sarcopenia, an aging-related disease of skeletal muscle, but also to osteopenia and shorter longevity. Aging is regulated by adipokines as well, and it should be considered that aging could be accelerated by 'imbalanced adipokines' in patients with a genetic background of progeria. Moreover, we reported the effects of intensive multifactorial intervention on diabetic vascular complications and mortality in patients with type 2 diabetes in a large-scale clinical trial, the J-DOIT3, and the results of subsequent sub-analyses of renal events and fracture events. Various approaches of research enable us of endocrinologists to elucidate the physiology of hormone signaling, the mechanisms underlying the development of endocrine diseases, and the appropriate treatment measures. These approaches also raise fundamental questions, but addressing them in an appropriate manner will surely contribute to the further development of endocrinology.
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Affiliation(s)
- Takayoshi Sasako
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
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3
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Demko J, Saha B, Takagi E, Mannis A, Weber R, Pearce D. Coordinated Regulation of Renal Glucose Reabsorption and Gluconeogenesis by mTORC2 and Potassium. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.22.600201. [PMID: 38979219 PMCID: PMC11230149 DOI: 10.1101/2024.06.22.600201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Background The kidney proximal tubule is uniquely responsible for reabsorption of filtered glucose and gluconeogenesis (GNG). Insulin stimulates glucose transport and suppresses GNG in the proximal tubule, however, the signaling mechanisms and coordinated regulation of these processes remain poorly understood. The kinase complex mTORC2 is critical for regulation of growth, metabolism, solute transport, and electrolyte homeostasis in response to a wide array of inputs. Here we examined its role in the regulation of renal glucose reabsorption and GNG. Methods Rictor, an essential component of mTORC2, was knocked out using the Pax8-LC1 system to generate inducible tubule specific Rictor knockout (TRKO) mice. These animals were subjected to fasting, refeeding, and variation in dietary K + . Metabolic parameters including glucose homeostasis and renal function were assessed in balance cages. Kidneys and livers were also harvested for molecular analysis of gluconeogenic enzymes, mTORC2-regulated targets, and plasma membrane glucose transporters. Results On a normal chow diet, TRKO mice had marked glycosuria despite indistinguishable blood glucose relative to WT controls. Kidney plasma membrane showed lower SGLT2 and SGLT1 in the fed state, supporting reduced renal glucose reabsorption. Additional metabolic testing provided evidence for renal insulin resistance with elevated fasting insulin, impaired pyruvate tolerance, elevated hemoglobin A1c, and increased renal gluconeogenic enzymes in the fasted and fed states. These effects were correlated with reduced downstream phosphorylation of Akt and the transcription factor FOXO4, identifying a novel role of FOXO4 in the kidney. Interestingly, high dietary K + prevented glycosuria and excessive GNG in TRKO mice, despite persistent reduction in mTORC2 substrate phosphorylation. Conclusion Renal tubule mTORC2 is critical for coordinated regulation of sodium-glucose cotransport by SGLT2 and SGLT1 as well as renal GNG. Dietary K + promotes glucose reabsorption and suppresses GNG independently of insulin signaling and mTORC2, potentially providing an alternative signaling mechanism in states of insulin resistance. SIGNIFICANCE STATEMENT The kidney contributes to regulation of blood glucose through reabsorption of filtered glucose and gluconeogenesis. This study shows that mTORC2 and dietary potassium coordinate the regulation of sodium-glucose cotransport and glucose production in the kidney via independent mechanisms. New insights into the regulation of these processes in the kidney offer promising implications for diabetes mellitus management and treatment.
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Hasenour CM, Banerjee DR, Young JD. Metabolic Fluxes in the Renal Cortex Are Dysregulated In Vivo in Response to High-Fat Diet. Diabetes 2024; 73:903-908. [PMID: 38502790 PMCID: PMC11109784 DOI: 10.2337/db23-0710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 03/13/2024] [Indexed: 03/21/2024]
Abstract
Diabetes and obesity are risk factors for kidney disease. Whereas renal glucose production increases in diabetes, recent data suggest that gluconeogenic and oxidative capacity decline in kidney disease. Thus, metabolic dysregulation caused by diet-induced insulin resistance may sensitize the kidney for a loss in function. Here, we examined how diet-induced insulin resistance disrupts mitochondrial metabolic fluxes in the renal cortex in vivo. C57BL/6J mice were rendered insulin resistant through high-fat (HF) feeding; anaplerotic, cataplerotic, and oxidative metabolic fluxes in the cortex were quantified through 13C-isotope tracing during a hyperinsulinemic-euglycemic clamp. As expected, HF-fed mice exhibited increased body weight, gluconeogenesis, and systemic insulin resistance compared with chow-fed mice. Relative to the citric acid cycle, HF feeding increased metabolic flux through pyruvate carboxylation (anaplerosis) and phosphoenolpyruvate carboxykinase (cataplerosis) and decreased flux through the pyruvate dehydrogenase complex in the cortex. Furthermore, the relative flux from nonpyruvate sources of acetyl-CoA profoundly increased in the cortex of HF-fed mice, correlating with a marker of oxidative stress. The data demonstrate that HF feeding spares pyruvate from dehydrogenation at the expense of increasing cataplerosis, which may underpin renal gluconeogenesis during insulin resistance; the results also support the hypothesis that dysregulated oxidative metabolism in the kidney contributes to metabolic disease. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Clinton M. Hasenour
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN
| | - Deveena R. Banerjee
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Jamey D. Young
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, TN
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
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Hatano R, Lee E, Sato H, Kiuchi M, Hirahara K, Nakagawa Y, Shimano H, Nakayama T, Tanaka T, Miki T. Hepatic ketone body regulation of renal gluconeogenesis. Mol Metab 2024; 84:101934. [PMID: 38604598 PMCID: PMC11039402 DOI: 10.1016/j.molmet.2024.101934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/20/2024] [Accepted: 04/02/2024] [Indexed: 04/13/2024] Open
Abstract
OBJECTIVES During fasting, liver pivotally regulates blood glucose levels through glycogenolysis and gluconeogenesis. Kidney also produces glucose through gluconeogenesis. Gluconeogenic genes are transactivated by fasting, but their expression patterns are chronologically different between the two organs. We find that renal gluconeogenic gene expressions are positively correlated with the blood β-hydroxybutyrate concentration. Thus, we herein aim to investigate the regulatory mechanism and its physiological implications. METHODS Gluconeogenic gene expressions in liver and kidney were examined in hyperketogenic mice such as high-fat diet (HFD)-fed and ketogenic diet-fed mice, and in hypoketogenic PPARα knockout (PPARα-/-) mice. Renal gluconeogenesis was evaluated by rise in glycemia after glutamine loading in vivo. Functional roles of β-hydroxybutyrate in the regulation of renal gluconeogenesis were investigated by metabolome analysis and RNA-seq analysis of proximal tubule cells. RESULTS Renal gluconeogenic genes were transactivated concurrently with blood β-hydroxybutyrate uprise under ketogenic states, but the increase was blunted in hypoketogenic PPARα-/- mice. Administration of 1,3-butandiol, a ketone diester, transactivated renal gluconeogenic gene expression in fasted PPARα-/- mice. In addition, HFD-fed mice showed fasting hyperglycemia along with upregulated renal gluconeogenic gene expression, which was blunted in HFD-fed PPARα-/- mice. In vitro experiments and metabolome analysis in renal tubular cells showed that β-hydroxybutyrate directly promotes glucose and NH3 production through transactivating gluconeogenic genes. In addition, RNA-seq analysis revealed that β-hydroxybutyrate-induced transactivation of Pck1 was mediated by C/EBPβ. CONCLUSIONS Our findings demonstrate that β-hydroxybutyrate mediates hepato-renal interaction to maintain homeostatic regulation of blood glucose and systemic acid-base balance through renal gluconeogenesis regulation.
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Affiliation(s)
- Ryo Hatano
- Department of Medical Physiology, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan
| | - Eunyoung Lee
- Department of Medical Physiology, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan; Research Institute of Disaster Medicine (RIDM), Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan
| | - Hiromi Sato
- Laboratory of Clinical Pharmacology and Pharmacometrics, Chiba University, Graduate School of Pharmaceutical Sciences, Chiba 260-8670, Japan
| | - Masahiro Kiuchi
- Department of Immunology, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan
| | - Kiyoshi Hirahara
- Research Institute of Disaster Medicine (RIDM), Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan; Department of Immunology, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan
| | - Yoshimi Nakagawa
- Division of Complex Biosystem Research, Department of Research and Development, Institute of Natural Medicine, University of Toyama, Toyama 930-0194, Japan
| | - Hitoshi Shimano
- Department of Endocrinology and Metabolism, Institute of Medicine, University of Tsukuba, Ibaraki 305-8575, Japan
| | - Toshinori Nakayama
- Department of Immunology, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan
| | - Tomoaki Tanaka
- Research Institute of Disaster Medicine (RIDM), Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan; Department of Molecular Diagnosis, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan
| | - Takashi Miki
- Department of Medical Physiology, Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan; Research Institute of Disaster Medicine (RIDM), Chiba University, Graduate School of Medicine, Chiba 260-8670, Japan.
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Sasako T. Exploring mechanisms underlying diabetes comorbidities and strategies to prevent vascular complications. Diabetol Int 2024; 15:34-40. [PMID: 38264227 PMCID: PMC10800323 DOI: 10.1007/s13340-023-00677-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 11/15/2023] [Indexed: 01/25/2024]
Abstract
It is important to prevent not only diabetic complications but also diabetic comorbidities in diabetes care. We have elucidated multifaceted insulin action in various tissues mainly by means of model mice, and it was revealed that insulin regulates endoplasmic reticulum (ER) stress response during feeding, whereas ER stress 'response failure' contributes to the development of steatohepatitis, one of the major diabetic comorbidities. Insulin regulates gluconeogenesis not only in the liver but also in the proximal tubules of the kidney, which is also suppressed by reabsorbed glucose in the latter. In skeletal muscle, another important insulin-targeted tissue, impaired insulin/IGF-1 signaling leads not only to sarcopenia, an aging-related disease, but also to bone loss and shorter longevity. Aging is regulated by adipokines as well, and it is deemed to be accelerated by 'imbalanced adipokines' in combination with genetic background of progeria. Moreover, we reported effects of intensive multifactorial intervention on diabetic complications and mortality in patients with type 2 diabetes in a large-scale clinical trial, the J-DOIT3, followed by reports of subsequent sub-analyses of renal events and fracture events. Various approaches to elucidate the mechanisms underlying the development of diabetes and how it should be treated are expected to help us improve diabetes management.
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Affiliation(s)
- Takayoshi Sasako
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo, 113-0033 Japan
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Packer M. Fetal Reprogramming of Nutrient Surplus Signaling, O-GlcNAcylation, and the Evolution of CKD. J Am Soc Nephrol 2023; 34:1480-1491. [PMID: 37340541 PMCID: PMC10482065 DOI: 10.1681/asn.0000000000000177] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 06/07/2023] [Indexed: 06/22/2023] Open
Abstract
ABSTRACT Fetal kidney development is characterized by increased uptake of glucose, ATP production by glycolysis, and upregulation of mammalian target of rapamycin (mTOR) and hypoxia-inducible factor-1 alpha (HIF-1 α ), which (acting in concert) promote nephrogenesis in a hypoxic low-tubular-workload environment. By contrast, the healthy adult kidney is characterized by upregulation of sirtuin-1 and adenosine monophosphate-activated protein kinase, which enhances ATP production through fatty acid oxidation to fulfill the needs of a normoxic high-tubular-workload environment. During stress or injury, the kidney reverts to a fetal signaling program, which is adaptive in the short term, but is deleterious if sustained for prolonged periods when both oxygen tension and tubular workload are heightened. Prolonged increases in glucose uptake in glomerular and proximal tubular cells lead to enhanced flux through the hexosamine biosynthesis pathway; its end product-uridine diphosphate N -acetylglucosamine-drives the rapid and reversible O-GlcNAcylation of thousands of intracellular proteins, typically those that are not membrane-bound or secreted. Both O-GlcNAcylation and phosphorylation act at serine/threonine residues, but whereas phosphorylation is regulated by hundreds of specific kinases and phosphatases, O-GlcNAcylation is regulated only by O-GlcNAc transferase and O-GlcNAcase, which adds or removes N-acetylglucosamine, respectively, from target proteins. Diabetic and nondiabetic CKD is characterized by fetal reprogramming (with upregulation of mTOR and HIF-1 α ) and increased O-GlcNAcylation, both experimentally and clinically. Augmentation of O-GlcNAcylation in the adult kidney enhances oxidative stress, cell cycle entry, apoptosis, and activation of proinflammatory and profibrotic pathways, and it inhibits megalin-mediated albumin endocytosis in glomerular mesangial and proximal tubular cells-effects that can be aggravated and attenuated by augmentation and muting of O-GlcNAcylation, respectively. In addition, drugs with known nephroprotective effects-angiotensin receptor blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter 2 inhibitors-are accompanied by diminished O-GlcNAcylation in the kidney, although the role of such suppression in mediating their benefits has not been explored. The available evidence supports further work on the role of uridine diphosphate N -acetylglucosamine as a critical nutrient surplus sensor (acting in concert with upregulated mTOR and HIF-1 α signaling) in the development of diabetic and nondiabetic CKD.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute , Dallas , Texas and Imperial College , London , United Kingdom
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Hasegawa K, Sakamaki Y, Tamaki M, Wakino S. PCK1 Protects against Mitoribosomal Defects in Diabetic Nephropathy in Mouse Models. J Am Soc Nephrol 2023; 34:1343-1365. [PMID: 37199399 PMCID: PMC10400109 DOI: 10.1681/asn.0000000000000156] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 05/19/2023] Open
Abstract
SIGNIFICANCE STATEMENT Renal gluconeogenesis plays an important role in the pathogenesis of diabetic nephropathy (DN). Proximal tubular phosphoenolpyruvate carboxykinase1 (PEPCK1) is the rate-limiting enzyme in gluconeogenesis. However, the functions of PEPCK1 have not been elucidated. We describe the novel role of PEPCK1 as a mitoribosomal protector using Pck1 transgenic (TG) mice and knockout mice. Pck1 blocks excessive glycolysis by suppressing the upregulation of excess HK2 (the rate-limiting enzyme of glycolysis). Notably, Pck1 overexpression retains mitoribosomal function and suppresses renal fibrosis. The renal and mitoribosomal protective roles of Pck1 may provide important clues for understanding DN pathogenesis and provide novel therapeutic targets. BACKGROUND Phosphoenolpyruvate carboxykinase (PEPCK) is part of the gluconeogenesis pathway, which maintains fasting glucose levels and affects renal physiology. PEPCK consists of two isoforms-PEPCK1 and PEPCK2-that the Pck1 and Pck2 genes encode. Gluconeogenesis increases in diabetic nephropathy (DN), escalating fasting and postprandial glucose levels. Sodium-glucose cotransporter-2 inhibitors increase hepatic and renal gluconeogenesis. We used genetically modified mice to investigate whether renal gluconeogenesis and Pck1 activity are renoprotective in DN. METHODS We investigated the expression of Pck1 in the proximal tubule (PTs) of streptozotocin (STZ)-treated diabetic mice. We studied the phenotypic changes in PT-specific transgenic (TG) mice and PT-specific Pck1 conditional knockout (CKO) mice. RESULTS The expression of Pck1 in PTs was downregulated in STZ-treated diabetic mice when they exhibited albuminuria. TG mice overexpressing Pck1 had improved albuminuria, concomitant with the mitigation of PT cell apoptosis and deposition of peritubular type IV collagen. Moreover, CKO mice exhibited PT cell apoptosis and type IV collagen deposition, findings also observed in STZ-treated mice. Renal fibrotic changes in CKO mice were associated with increasing defects in mitochondrial ribosomes (mitoribosomes). The TG mice were protected against STZ-induced mitoribosomal defects. CONCLUSION PCK1 preserves mitoribosomal function and may play a novel protective role in DN.
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Affiliation(s)
- Kazuhiro Hasegawa
- Department of Nephrology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Yusuke Sakamaki
- Department of Internal Medicine, Tokyo Dental College, Ichikawa General Hospital, Chiba, Japan
| | - Masanori Tamaki
- Department of Nephrology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
| | - Shu Wakino
- Department of Nephrology, Tokushima University Graduate School of Biomedical Sciences, Tokushima, Japan
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Sharma A, Ferreira JP, Zannad F, Pocock SJ, Filippatos G, Pfarr E, Petrini M, Kraus BJ, Wanner C, Packer M, Butler J, Anker SD. Cardiac and kidney benefits of empagliflozin in heart failure across the spectrum of kidney function: Insights from the EMPEROR-Preserved trial. Eur J Heart Fail 2023; 25:1337-1348. [PMID: 37062851 DOI: 10.1002/ejhf.2857] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 02/24/2023] [Accepted: 04/08/2023] [Indexed: 04/18/2023] Open
Abstract
AIM In the EMPEROR-Preserved trial, empagliflozin improved clinical outcomes of patients with heart failure (HF) with preserved ejection fraction. In this pre-specified analysis, we aim to study the effect of empagliflozin on cardiovascular and kidney outcomes across the spectrum of kidney function. METHODS AND RESULTS Patients were categorized by the presence or absence of chronic kidney disease (CKD) at baseline (CKD defined by an estimated glomerular filtration rate [eGFR] <60 ml/min/1.73 m2 or urine albumin to creatinine ratio >300 mg/g). The primary and key secondary outcomes were (i) a composite of cardiovascular death or first HF hospitalization (primary outcome); (ii) total number of HF hospitalization, (iii) eGFR slope; and a pre-specified exploratory composite kidney outcome including a sustained ≥40% decline in eGFR, chronic dialysis or renal transplant. The median follow-up was 26.2 months. A total of 5988 patients were randomized to empagliflozin or placebo, of whom 3198 (53.5%) had CKD. Irrespective of CKD status, empagliflozin reduced the primary outcome (with CKD: hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.69-0.94; without CKD: HR 0.75, 95% CI 0.60-0.95; interaction p = 0.67) and total (first and recurrent) hospitalizations for HF (with CKD: HR 0.68, 95% CI 0.54-0.86; without CKD: HR 0.89, 95% CI 0.66-1.21; interaction p = 0.17). Empagliflozin slowed the slope of eGFR decline by 1.43 (1.01-1.85) ml/min/1.73 m2 /year in patients with CKD and 1.31 (0.88-1.74) ml/min/1.73 m2 /year in patients without CKD (interaction p = 0.70). Empagliflozin did not reduce the pre-specified kidney outcome in patients with or without CKD (with CKD: HR 0.97, 95% CI 0.71-1.34; without CKD: HR 0.92, 95% CI 0.58-1.48; interaction p = 0.86) but slowed progression to macroalbuminuria and reduced the risk of acute kidney injury. The effect of empagliflozin on the primary composite outcome and the key secondary outcomes was consistent across five baseline eGFR categories (all interaction p >0.05). Empagliflozin was well tolerated independent of CKD status. CONCLUSIONS In EMPEROR-Preserved, empagliflozin had a beneficial effect on the key efficacy outcomes in patients with and without CKD. Overall, the benefit and safety of empagliflozin was consistent across a wide range of kidney function spectrum, down to a baseline eGFR of 20 ml/min/1.73 m2 .
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Affiliation(s)
| | - João Pedro Ferreira
- Cardiovascular Research and Development Center, Faculty of Medicine of the University of Porto, Porto, Portugal
- Centre d'Investigations Cliniques Plurithématique 14-33, and Inserm U1116, CHRU, F-CRIN INI-CRCT (Cardiovascular and Renal Clinical Trialists), Université de Lorraine, Nancy, France
| | - Faiez Zannad
- Centre d'Investigations Cliniques Plurithématique 14-33, and Inserm U1116, CHRU, F-CRIN INI-CRCT (Cardiovascular and Renal Clinical Trialists), Université de Lorraine, Nancy, France
| | - Stuart J Pocock
- Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, UK
| | - Gerasimos Filippatos
- National and Kapodistrian University of Athens School of Medicine, Athens University Hospital Attikon, Athens, Greece
| | - Egon Pfarr
- Boehringer Ingelheim Pharma GmbH & Co KG, Ingelheim, Germany
| | | | - Bettina J Kraus
- Boehringer Ingelheim International GmbH, Ingelheim, Germany; Department of Internal Medicine I, University Hospital Würzburg, Würzburg, Germany
| | | | - Milton Packer
- Baylor University Medical Center, Dallas, TX, USA
- Imperial College, London, UK
| | - Javed Butler
- Baylor Scott and White Research Institute, Dallas, TX, USA
- Department of Medicine, University of Mississippi School of Medicine, Jackson, MS, USA
| | - Stefan D Anker
- Department of Cardiology (CVK) and Berlin Institute of Health Center for Regenerative Therapies (BCRT), Berlin, Germany
- German Centre for Cardiovascular Research (DZHK) partner site Berlin, Berlin, Germany
- Charité Universitätsmedizin, Berlin, Germany
- Institute of Heart Diseases, Wrocław Medical University, Wrocław, Poland
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Sahoo B, Srivastava M, Katiyar A, Ecelbarger C, Tiwari S. Liver or kidney: Who has the oar in the gluconeogenesis boat and when? World J Diabetes 2023; 14:1049-1056. [PMID: 37547592 PMCID: PMC10401452 DOI: 10.4239/wjd.v14.i7.1049] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/20/2023] [Accepted: 04/11/2023] [Indexed: 07/12/2023] Open
Abstract
Gluconeogenesis is an endogenous process of glucose production from non-carbohydrate carbon substrates. Both the liver and kidneys express the key enzymes necessary for endogenous glucose production and its export into circulation. We would be remiss to add that more recently gluconeogenesis has been described in the small intestine, especially under high-protein, low-carbohydrate diets. The contribution of the liver glucose release, the net glucose flux, towards systemic glucose is already well known. The liver is, in most instances, the primary bulk contributor due to the sheer size of the organ (on average, over 1 kg). The contribution of the kidney (at just over 100 g each) to endogenous glucose production is often under-appreciated, especially on a weight basis. Glucose is released from the liver through the process of glycogenolysis and gluconeogenesis. Renal glucose release is almost exclusively due to gluconeogenesis, which occurs in only a fraction of the cells in that organ (proximal tubule cells). Thus, the efficiency of glucose production from other carbon sources may be superior in the kidney relative to the liver or at least on the level. In both these tissues, gluconeogenesis regulation is under tight hormonal control and depends on the availability of substrates. Liver and renal gluconeogenesis are differentially regulated under various pathological conditions. The impact of one source vs the other changes, based on post-prandial state, acid-base balance, hormonal status, and other less understood factors. Which organ has the oar (is more influential) in driving systemic glucose homeostasis is still in-conclusive and likely changes with the daily rhythms of life. We reviewed the literature on the differences in gluconeogenesis regulation between the kidneys and the liver to gain an insight into who drives the systemic glucose levels under various physiological and pathological conditions.
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Affiliation(s)
- Biswajit Sahoo
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Medha Srivastava
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Arpit Katiyar
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Carolyn Ecelbarger
- Department of Medicine, Georgetown University, Washington, DC 20057, United States
| | - Swasti Tiwari
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
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11
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Gao Z, Bao J, Hu Y, Tu J, Ye L, Wang L. Sodium-glucose Cotransporter 2 Inhibitors and Pathological Myocardial Hypertrophy. Curr Drug Targets 2023; 24:1009-1022. [PMID: 37691190 PMCID: PMC10879742 DOI: 10.2174/1389450124666230907115831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 08/18/2023] [Accepted: 08/23/2023] [Indexed: 09/12/2023]
Abstract
Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a new type of oral hypoglycemic drugs that exert a hypoglycemic effect by blocking the reabsorption of glucose in the proximal renal tubules, thus promoting the excretion of glucose from urine. Their hypoglycemic effect is not dependent on insulin. Increasing data shows that SGLT2 inhibitors improve cardiovascular outcomes in patients with type 2 diabetes. Previous studies have demonstrated that SGLT2 inhibitors can reduce pathological myocardial hypertrophy with or without diabetes, but the exact mechanism remains to be elucidated. To clarify the relationship between SGLT2 inhibitors and pathological myocardial hypertrophy, with a view to providing a reference for the future treatment thereof, this study reviewed the possible mechanisms of SGLT2 inhibitors in attenuating pathological myocardial hypertrophy. We focused specifically on the mechanisms in terms of inflammation, oxidative stress, myocardial fibrosis, mitochondrial function, epicardial lipids, endothelial function, insulin resistance, cardiac hydrogen and sodium exchange, and autophagy.
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Affiliation(s)
- Zhicheng Gao
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
- Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People’s Hospital (Affiliated People’s Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Jiaqi Bao
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
- Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People’s Hospital (Affiliated People’s Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Yilan Hu
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
- Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People’s Hospital (Affiliated People’s Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Junjie Tu
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
| | - Lifang Ye
- Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People’s Hospital (Affiliated People’s Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, China
| | - Lihong Wang
- The Second Clinical Medical College, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
- Heart Center, Department of Cardiovascular Medicine, Zhejiang Provincial People’s Hospital (Affiliated People’s Hospital), Hangzhou Medical College, Hangzhou, Zhejiang, China
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12
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Ahmad M, Abramovich I, Agranovich B, Nemirovski A, Gottlieb E, Hinden L, Tam J. Kidney Proximal Tubule GLUT2-More than Meets the Eye. Cells 2022; 12:cells12010094. [PMID: 36611887 PMCID: PMC9818791 DOI: 10.3390/cells12010094] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/06/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Tubulopathy plays a central role in the pathophysiology of diabetic kidney disease (DKD). Under diabetic conditions, the kidney proximal tubule cells (KPTCs) are exposed to an extensive amount of nutrients, most notably glucose; these nutrients deteriorate KPTCs function and promote the development and progression of DKD. Recently, the facilitative glucose transporter 2 (GLUT2) in KPTCs has emerged as a central regulator in the pathogenesis of DKD. This has been demonstrated by identifying its specific role in enhancing glucose reabsorption and glucotoxicity, and by deciphering its effect in regulating the expression of the sodium-glucose transporter 2 (SGLT2) in KPTCs. Moreover, reduction/deletion of KPTC-GLUT2 has been recently found to ameliorate DKD, raising the plausible idea of considering it as a therapeutic target against DKD. However, the underlying molecular mechanisms by which GLUT2 exerts its deleterious effects in KPTCs remain vague. Herein, we review the current findings on the proximal tubule GLUT2 biology and function under physiologic conditions, and its involvement in the pathophysiology of DKD. Furthermore, we shed new light on its cellular regulation during diabetic conditions.
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Affiliation(s)
- Majdoleen Ahmad
- Obesity and Metabolism Laboratory, Faculty of Medicine, The Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Ifat Abramovich
- Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 3525422, Israel
| | - Bella Agranovich
- Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 3525422, Israel
| | - Alina Nemirovski
- Obesity and Metabolism Laboratory, Faculty of Medicine, The Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
| | - Eyal Gottlieb
- Rappaport Faculty of Medicine and Research Institute, Technion, Haifa 3525422, Israel
| | - Liad Hinden
- Obesity and Metabolism Laboratory, Faculty of Medicine, The Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
- Correspondence: (L.H.); (J.T.); Tel.: +972-2-675-7650 (L.H.); +972-2-675-7645 (J.T.)
| | - Joseph Tam
- Obesity and Metabolism Laboratory, Faculty of Medicine, The Institute for Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel
- Correspondence: (L.H.); (J.T.); Tel.: +972-2-675-7650 (L.H.); +972-2-675-7645 (J.T.)
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13
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Nakamura M, Satoh N, Horita S, Nangaku M. Insulin-induced mTOR signaling and gluconeogenesis in renal proximal tubules: A mini-review of current evidence and therapeutic potential. Front Pharmacol 2022; 13:1015204. [PMID: 36299884 PMCID: PMC9589488 DOI: 10.3389/fphar.2022.1015204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 09/27/2022] [Indexed: 12/02/2022] Open
Abstract
Energy is continuously expended in the body, and gluconeogenesis maintains glucose homeostasis during starvation. Gluconeogenesis occurs in the liver and kidneys. The proximal tubule is the primary location for renal gluconeogenesis, accounting for up to 25% and 60% of endogenous glucose production during fasting and after a meal, respectively. The mechanistic target of rapamycin (mTOR), which exists downstream of the insulin pathway, plays an important role in regulating proximal tubular gluconeogenesis. mTOR is an atypical serine/threonine kinase present in two complexes. mTORC1 phosphorylates substrates that enhance anabolic processes such as mRNA translation and lipid synthesis and catabolic processes such as autophagy. mTORC2 regulates cytoskeletal dynamics and controls ion transport and proliferation via phosphorylation of SGK1. Therefore, mTOR signaling defects have been implicated in various pathological conditions, including cancer, cardiovascular disease, and diabetes. However, concrete elucidations of the associated mechanisms are still unclear. This review provides an overview of mTOR and describes the relationship between mTOR and renal.
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Affiliation(s)
- Motonobu Nakamura
- Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
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14
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Sasako T, Umehara T, Soeda K, Kaneko K, Suzuki M, Kobayashi N, Okazaki Y, Tamura-Nakano M, Chiba T, Accili D, Kahn CR, Noda T, Asahara H, Yamauchi T, Kadowaki T, Ueki K. Deletion of skeletal muscle Akt1/2 causes osteosarcopenia and reduces lifespan in mice. Nat Commun 2022; 13:5655. [PMID: 36198696 PMCID: PMC9535008 DOI: 10.1038/s41467-022-33008-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 08/19/2022] [Indexed: 01/23/2023] Open
Abstract
Aging is considered to be accelerated by insulin signaling in lower organisms, but it remained unclear whether this could hold true for mammals. Here we show that mice with skeletal muscle-specific double knockout of Akt1/2, key downstream molecules of insulin signaling, serve as a model of premature sarcopenia with insulin resistance. The knockout mice exhibit a progressive reduction in skeletal muscle mass, impairment of motor function and systemic insulin sensitivity. They also show osteopenia, and reduced lifespan largely due to death from debilitation on normal chow and death from tumor on high-fat diet. These phenotypes are almost reversed by additional knocking out of Foxo1/4, but only partially by additional knocking out of Tsc2 to activate the mTOR pathway. Overall, our data suggest that, unlike in lower organisms, suppression of Akt activity in skeletal muscle of mammals associated with insulin resistance and aging could accelerate osteosarcopenia and consequently reduce lifespan.
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Affiliation(s)
- Takayoshi Sasako
- grid.26999.3d0000 0001 2151 536XDepartment of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan ,grid.45203.300000 0004 0489 0290Department of Molecular Diabetic Medicine, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Toshihiro Umehara
- grid.26999.3d0000 0001 2151 536XDepartment of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kotaro Soeda
- grid.26999.3d0000 0001 2151 536XDepartment of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan ,grid.45203.300000 0004 0489 0290Department of Molecular Diabetic Medicine, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Kazuma Kaneko
- grid.26999.3d0000 0001 2151 536XDepartment of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Miho Suzuki
- grid.26999.3d0000 0001 2151 536XDepartment of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Naoki Kobayashi
- grid.45203.300000 0004 0489 0290Department of Molecular Diabetic Medicine, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Yukiko Okazaki
- grid.26999.3d0000 0001 2151 536XDepartment of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Miwa Tamura-Nakano
- grid.45203.300000 0004 0489 0290Communal Laboratory, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Tomoki Chiba
- grid.265073.50000 0001 1014 9130Department of Systems BioMedicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Domenico Accili
- grid.21729.3f0000000419368729Columbia University College of Physicians & Surgeons, Department of Medicine, New York, NY USA
| | - C. Ronald Kahn
- grid.38142.3c000000041936754XJoslin Diabetes Center, Harvard Medical School, Boston, MA USA
| | - Tetsuo Noda
- grid.410807.a0000 0001 0037 4131Department of Cell Biology, Cancer Institute, Japanese Foundation of Cancer Research, Tokyo, Japan
| | - Hiroshi Asahara
- grid.265073.50000 0001 1014 9130Department of Systems BioMedicine, Tokyo Medical and Dental University, Tokyo, Japan
| | - Toshimasa Yamauchi
- grid.26999.3d0000 0001 2151 536XDepartment of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takashi Kadowaki
- grid.26999.3d0000 0001 2151 536XDepartment of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan ,grid.410813.f0000 0004 1764 6940Toranomon Hospital, Tokyo, Japan
| | - Kohjiro Ueki
- grid.45203.300000 0004 0489 0290Department of Molecular Diabetic Medicine, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan ,grid.26999.3d0000 0001 2151 536XDepartment of Molecular Diabetetology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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15
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Wilson PC, Muto Y, Wu H, Karihaloo A, Waikar SS, Humphreys BD. Multimodal single cell sequencing implicates chromatin accessibility and genetic background in diabetic kidney disease progression. Nat Commun 2022; 13:5253. [PMID: 36068241 PMCID: PMC9448792 DOI: 10.1038/s41467-022-32972-z] [Citation(s) in RCA: 57] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 08/25/2022] [Indexed: 11/09/2022] Open
Abstract
The proximal tubule is a key regulator of kidney function and glucose metabolism. Diabetic kidney disease leads to proximal tubule injury and changes in chromatin accessibility that modify the activity of transcription factors involved in glucose metabolism and inflammation. Here we use single nucleus RNA and ATAC sequencing to show that diabetic kidney disease leads to reduced accessibility of glucocorticoid receptor binding sites and an injury-associated expression signature in the proximal tubule. We hypothesize that chromatin accessibility is regulated by genetic background and closely-intertwined with metabolic memory, which pre-programs the proximal tubule to respond differently to external stimuli. Glucocorticoid excess has long been known to increase risk for type 2 diabetes, which raises the possibility that glucocorticoid receptor inhibition may mitigate the adverse metabolic effects of diabetic kidney disease.
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Affiliation(s)
- Parker C Wilson
- Division of Anatomic and Molecular Pathology, Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO, USA
| | - Yoshiharu Muto
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Haojia Wu
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, MO, USA
| | - Anil Karihaloo
- Novo Nordisk Research Center Seattle Inc, Seattle, WA, USA
| | - Sushrut S Waikar
- Section of Nephrology, Department of Medicine, Boston University School of Medicine, Boston Medical Center, Boston, MA, USA
| | - Benjamin D Humphreys
- Division of Nephrology, Department of Medicine, Washington University in St. Louis, St. Louis, MO, USA.
- Department of Developmental Biology, Washington University in St. Louis, St. Louis, MO, USA.
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16
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Hotait ZS, Lo Cascio JN, Choos END, Shepard BD. The sugar daddy: the role of the renal proximal tubule in glucose homeostasis. Am J Physiol Cell Physiol 2022; 323:C791-C803. [PMID: 35912988 PMCID: PMC9448277 DOI: 10.1152/ajpcell.00225.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/26/2022] [Accepted: 07/26/2022] [Indexed: 11/22/2022]
Abstract
Renal blood flow represents >20% of total cardiac output and with this comes the great responsibility of maintaining homeostasis through the intricate regulation of solute handling. Through the processes of filtration, reabsorption, and secretion, the kidneys ensure that solutes and other small molecules are either returned to circulation, catabolized within renal epithelial cells, or excreted through the process of urination. Although this occurs throughout the renal nephron, one segment is tasked with the bulk of solute reabsorption-the proximal tubule. Among others, the renal proximal tubule is entirely responsible for the reabsorption of glucose, a critical source of energy that fuels the body. In addition, it is the only other site of gluconeogenesis outside of the liver. When these processes go awry, pathophysiological conditions such as diabetes and acidosis result. In this review, we highlight the recent advances made in understanding these processes that occur within the renal proximal tubule. We focus on the physiological mechanisms at play regarding glucose reabsorption and glucose metabolism, emphasize the conditions that occur under diseased states, and explore the emerging class of therapeutics that are responsible for restoring homeostasis.
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Affiliation(s)
- Zahraa S Hotait
- Department of Human Science, Georgetown University, Washington, District of Columbia
| | - Julia N Lo Cascio
- Department of Human Science, Georgetown University, Washington, District of Columbia
| | - Elijah N D Choos
- Department of Human Science, Georgetown University, Washington, District of Columbia
| | - Blythe D Shepard
- Department of Human Science, Georgetown University, Washington, District of Columbia
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17
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Ida-Naitoh M, Tokuyama H, Futatsugi K, Yasuda M, Adachi K, Kanda T, Tanabe Y, Wakino S, Itoh H. Proximal-tubule molecular relay from early Protein diaphanous homolog 1 to late Rho-associated protein kinase 1 regulates kidney function in obesity-induced kidney damage. Kidney Int 2022; 102:798-814. [PMID: 35716954 DOI: 10.1016/j.kint.2022.05.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Revised: 04/28/2022] [Accepted: 05/09/2022] [Indexed: 01/11/2023]
Abstract
The small GTPase protein RhoA has two effectors, ROCK (Rho-associated protein kinase 1) and mDIA1 (Protein diaphanous homolog 1), which cooperate reciprocally. However, temporal regulation of RhoA and its effectors in obesity-induced kidney damage remains unclear. Here, we investigated the role of RhoA activation in the proximal tubules at the early and late stages of obesity-induced kidney damage. In mice, a three week high-fat diet induced proximal tubule hypertrophy and damage without increased albuminuria, and RhoA/mDIA1 activation without ROCK activation. Conversely, a 12- week high-fat diet induced proximal tubule hypertrophy, proximal tubule damage, increased albuminuria, and RhoA/ROCK activation without mDIA1 elevation. Proximal tubule hypertrophy resulting from cell cycle arrest accompanied by downregulation of the multifunctional cyclin-dependent kinase inhibitor p27Kip1 was elicited by RhoA activation. Mice overexpressing proximal tubule-specific and dominant-negative RHOA display amelioration of high-fat diet-induced kidney hypertrophy, cell cycle abnormalities, inflammation, and renal impairment. In human proximal tubules cells, mechanical stretch mimicking hypertrophy activated ROCK, which triggered inflammation. In human kidney samples from normal individuals with a body mass index of about 25, proximal tubule cell size correlated with body mass index, proximal tubule cell damages, and mDIA1 expression. Thus, RhoA activation in proximal tubules is critical for the initiation and progression of obesity-induced kidney damage. Hence, the switch in the downstream RhoA effector in proximal tubule represents a transition from normal to pathogenic kidney adaptation and to body weight gain, leading to obesity-induced kidney damage.
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Affiliation(s)
- Makiko Ida-Naitoh
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Hirobumi Tokuyama
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Koji Futatsugi
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Marie Yasuda
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Keika Adachi
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Takeshi Kanda
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Yoshiyuki Tanabe
- Department of Clinical Pharmacology, Yokohama University of Pharmacy, Kanagawa, Japan
| | - Shu Wakino
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
| | - Hiroshi Itoh
- Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan
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18
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Sharma R, Sahoo B, Srivastava A, Tiwari S. Reduced insulin signaling and high glucagon in early insulin resistance impaired fast-fed regulation of renal gluconeogenesis via insulin receptor substrate. J Cell Biochem 2022; 123:1327-1339. [PMID: 35644013 DOI: 10.1002/jcb.30294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 05/11/2022] [Accepted: 05/18/2022] [Indexed: 11/08/2022]
Abstract
Gluconeogenesis is one of the key processes through which the kidney contributes to glucose homeostasis. Urinary exosomes (uE) have been used to study renal gene regulation noninvasively in humans and rodents. Recently, we demonstrated fast-fed regulation of phosphoenolpyruvate carboxykinase (PEPCK), the rate-limiting enzyme for gluconeogenesis, in human uE. The regulation was impaired in subjects with early insulin resistance. Here, we studied primary human proximal tubule cells (hPT) and human uE to elucidate a potential link between insulin resistance and fast-fed regulation of renal PEPCK. We demonstrate that fasted hPTs had higher PEPCK and insulin receptor substrate-2 (IRS2) mRNA and protein levels, relative to fed cells. The fast-fed regulation was, however, attenuated in insulin receptor knockdown (IRKO) hPTs. The IRKO was confirmed by the blunted insulin-induced response on PEPCK, PGC1α, p-IR, and p-AKT expression in IRKO cells. Exosomes secreted by the wild-type or IRKO hPT showed similar regulation to the respective hPT. Similarly, in human uE, the relative abundance of IRS-2 mRNA (to IRS1) was higher in the fasted state relative to the fed condition. However, the fast-fed difference was absent in subjects with early insulin resistance. These subjects had higher circulating glucagon levels relative to subjects with optimal insulin sensitivity. Furthermore, in hPT cells, glucagon significantly induced PEPCK and IRS2 gene, and gluconeogenesis. IR knockdown in hPT cells further increased the gene expression levels. Together the data suggest that reduced insulin sensitivity and high glucagon in early insulin resistance may impair renal gluconeogenesis via IRS2 regulation.
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Affiliation(s)
- Rajni Sharma
- Department of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Biswajit Sahoo
- Department of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Aneesh Srivastava
- Department of Urology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Swasti Tiwari
- Department of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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19
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Vallon V, Nakagawa T. Renal Tubular Handling of Glucose and Fructose in Health and Disease. Compr Physiol 2021; 12:2995-3044. [PMID: 34964123 PMCID: PMC9832976 DOI: 10.1002/cphy.c210030] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
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.
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Affiliation(s)
- Volker Vallon
- Division of Nephrology and Hypertension, Department of Medicine, University of California San Diego, La Jolla, California, USA,Department of Pharmacology, University of California San Diego, La Jolla, California, USA,VA San Diego Healthcare System, San Diego, California, USA,Correspondence to and
| | - Takahiko Nakagawa
- Division of Nephrology, Rakuwakai-Otowa Hospital, Kyoto, Japan,Correspondence to and
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20
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Faivre A, Verissimo T, Auwerx H, Legouis D, de Seigneux S. Tubular Cell Glucose Metabolism Shift During Acute and Chronic Injuries. Front Med (Lausanne) 2021; 8:742072. [PMID: 34778303 PMCID: PMC8585753 DOI: 10.3389/fmed.2021.742072] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 10/11/2021] [Indexed: 12/28/2022] Open
Abstract
Acute and chronic kidney disease are responsible for large healthcare costs worldwide. During injury, kidney metabolism undergoes profound modifications in order to adapt to oxygen and nutrient shortage. Several studies highlighted recently the importance of these metabolic adaptations in acute as well as in chronic phases of renal disease, with a potential deleterious effect on fibrosis progression. Until recently, glucose metabolism in the kidney has been poorly studied, even though the kidney has the capacity to use and produce glucose, depending on the segment of the nephron. During physiology, renal proximal tubular cells use the beta-oxidation of fatty acid to generate large amounts of energy, and can also produce glucose through gluconeogenesis. In acute kidney injury, proximal tubular cells metabolism undergo a metabolic shift, shifting away from beta-oxidation of fatty acids and gluconeogenesis toward glycolysis. In chronic kidney disease, the loss of fatty acid oxidation is also well-described, and data about glucose metabolism are emerging. We here review the modifications of proximal tubular cells glucose metabolism during acute and chronic kidney disease and their potential consequences, as well as the potential therapeutic implications.
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Affiliation(s)
- Anna Faivre
- Laboratory of Nephrology, Geneva University Hospitals, Geneva, Switzerland.,Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Thomas Verissimo
- Laboratory of Nephrology, Geneva University Hospitals, Geneva, Switzerland.,Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - Hannah Auwerx
- Laboratory of Nephrology, Geneva University Hospitals, Geneva, Switzerland.,Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - David Legouis
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland.,Intensive Care Unit, Department of Acute Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Sophie de Seigneux
- Laboratory of Nephrology, Geneva University Hospitals, Geneva, Switzerland.,Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
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21
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Carter RN, Gibbins MTG, Barrios-Llerena ME, Wilkie SE, Freddolino PL, Libiad M, Vitvitsky V, Emerson B, Le Bihan T, Brice M, Su H, Denham SG, Homer NZM, Mc Fadden C, Tailleux A, Faresse N, Sulpice T, Briand F, Gillingwater T, Ahn KH, Singha S, McMaster C, Hartley RC, Staels B, Gray GA, Finch AJ, Selman C, Banerjee R, Morton NM. The hepatic compensatory response to elevated systemic sulfide promotes diabetes. Cell Rep 2021; 37:109958. [PMID: 34758301 PMCID: PMC8595646 DOI: 10.1016/j.celrep.2021.109958] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 07/06/2021] [Accepted: 10/15/2021] [Indexed: 12/12/2022] Open
Abstract
Impaired hepatic glucose and lipid metabolism are hallmarks of type 2 diabetes. Increased sulfide production or sulfide donor compounds may beneficially regulate hepatic metabolism. Disposal of sulfide through the sulfide oxidation pathway (SOP) is critical for maintaining sulfide within a safe physiological range. We show that mice lacking the liver- enriched mitochondrial SOP enzyme thiosulfate sulfurtransferase (Tst-/- mice) exhibit high circulating sulfide, increased gluconeogenesis, hypertriglyceridemia, and fatty liver. Unexpectedly, hepatic sulfide levels are normal in Tst-/- mice because of exaggerated induction of sulfide disposal, with associated suppression of global protein persulfidation and nuclear respiratory factor 2 target protein levels. Hepatic proteomic and persulfidomic profiles converge on gluconeogenesis and lipid metabolism, revealing a selective deficit in medium-chain fatty acid oxidation in Tst-/- mice. We reveal a critical role of TST in hepatic metabolism that has implications for sulfide donor strategies in the context of metabolic disease.
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Affiliation(s)
- Roderick N Carter
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK
| | - Matthew T G Gibbins
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK
| | - Martin E Barrios-Llerena
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK
| | - Stephen E Wilkie
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK; Glasgow Ageing Research Network (GARNER), Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Peter L Freddolino
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Marouane Libiad
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Victor Vitvitsky
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Barry Emerson
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK
| | | | - Madara Brice
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK
| | - Huizhong Su
- Cancer Research UK Edinburgh Centre, MRC Institute of Genetics & Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XR, UK
| | - Scott G Denham
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK
| | - Natalie Z M Homer
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK
| | - Clare Mc Fadden
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK
| | - Anne Tailleux
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U101-EGID, 59000, Lille, France
| | - Nourdine Faresse
- Physiogenex S.A.S, Prologue Biotech, 516 rue Pierre et Marie Curie, 31670 Labège, France
| | - Thierry Sulpice
- Physiogenex S.A.S, Prologue Biotech, 516 rue Pierre et Marie Curie, 31670 Labège, France
| | - Francois Briand
- Physiogenex S.A.S, Prologue Biotech, 516 rue Pierre et Marie Curie, 31670 Labège, France
| | - Tom Gillingwater
- College of Medicine & Veterinary Medicine, University of Edinburgh, Old Medical School (Anatomy), Teviot Place, Edinburgh EH8 9AG, UK
| | - Kyo Han Ahn
- Department of Chemistry, POSTECH, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyungbuk 37673, South Korea
| | - Subhankar Singha
- Department of Chemistry, POSTECH, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyungbuk 37673, South Korea
| | - Claire McMaster
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, UK
| | - Richard C Hartley
- School of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, UK
| | - Bart Staels
- Université de Lille, INSERM, CHU Lille, Institut Pasteur de Lille, U101-EGID, 59000, Lille, France
| | - Gillian A Gray
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK
| | - Andrew J Finch
- Cancer Research UK Edinburgh Centre, MRC Institute of Genetics & Molecular Medicine, University of Edinburgh, Western General Hospital, Edinburgh EH4 2XR, UK
| | - Colin Selman
- Glasgow Ageing Research Network (GARNER), Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow G12 8QQ, UK
| | - Ruma Banerjee
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Nicholas M Morton
- University/British Heart Foundation Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh EH16 4TJ, UK.
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22
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Magen D, Halloun R, Galderisi A, Caprio S, Weiss R. Relation of glomerular filtration to insulin resistance and related risk factors in obese children. Int J Obes (Lond) 2021; 46:374-380. [PMID: 34725443 DOI: 10.1038/s41366-021-01001-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/04/2021] [Accepted: 10/13/2021] [Indexed: 11/09/2022]
Abstract
BACKGROUND AND OBJECTIVE Childhood obesity is associated with later development of significant renal morbidity. We evaluated the impact of the degree of insulin sensitivity on estimated glomerular filtration rate (eGFR) and determined the factors associated with eGFR in obese children. We further tested the relation of eGFR to clinical outcomes such as blood pressure and microalbuminuria. MATERIALS AND METHODS We evaluated the relation of whole body insulin sensitivity and estimated glomerular filtration rate (eGFR) across the spectrum of obesity in children and adolescents. eGFR was calculated using the iCARE formula, which has been validated in obese children with varying glucose tolerance. RESULTS 1080 children and adolescents with overweight and obesity (701 females and 379 males) participated. Insulin sensitivity was a strongly negatively associated with (B = -2.72, p < 0.001) eGFR), even after adjustment for potential confounders. Male sex emerged to be significantly associated with eGFR with boys having greater values than girls (B = 18.82, p < 0.001). Age was a positively associated (B = 2.86, p < 0.001) with eGFR. Whole body and hepatic insulin sensitivity decreased across eGFR quartiles. Adjusted eGFR was tightly positively associated with systolic blood pressure (B = 0.09, p = 0.003) and negatively associated with the presence of microalbuminuria (B = -2.18, p = 0.04). CONCLUSIONS eGFR tends to increase with greater degrees of insulin resistance in children and adolescents representing hyperfiltration and is associated with cardiovascular risk factors. Longitudinal studies are needed to determine the natural history of childhood insulin resistance related hyperfiltration in regards to future kidney disease.
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Affiliation(s)
- Daniella Magen
- Department of Pediatrics, Ruth Children's Hospital, Rambam Medical Center, Haifa, Israel.,The Department of Pediatrics, Yale University, New-Haven, CT, USA
| | - Rana Halloun
- Department of Pediatrics, Ruth Children's Hospital, Rambam Medical Center, Haifa, Israel.,The Department of Pediatrics, Yale University, New-Haven, CT, USA
| | - Alfonso Galderisi
- Department of Woman and Child's Health, University of Padova, Padova, Italy
| | - Sonia Caprio
- The Department of Pediatrics, Yale University, New-Haven, CT, USA
| | - Ram Weiss
- Department of Pediatrics, Ruth Children's Hospital, Rambam Medical Center, Haifa, Israel. .,The Department of Pediatrics, Yale University, New-Haven, CT, USA.
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23
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Shepard BD, Ecelbarger CM. Sodium Glucose Transporter, Type 2 (SGLT2) Inhibitors (SGLT2i) and Glucagon-Like Peptide 1-Receptor Agonists: Newer Therapies in Whole-Body Glucose Stabilization. Semin Nephrol 2021; 41:331-348. [PMID: 34715963 DOI: 10.1016/j.semnephrol.2021.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Diabetes is a worldwide epidemic that is increasing rapidly to become the seventh leading cause of death in the world. The increased incidence of this disease mirrors a similar uptick in obesity and metabolic syndrome, and, collectively, these conditions can cause deleterious effects on a number of organ systems including the renal and cardiovascular systems. Historically, treatment of type 2 diabetes has focused on decreasing hyperglycemia and glycated hemoglobin levels. However, it now is appreciated that there is more to the puzzle. Emerging evidence has indicated that newer classes of diabetes drugs, sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide 1-receptor agonists, improve cardiovascular and renal function, while appropriately managing hyperglycemia. In this review, we highlight the recent clinical and preclinical studies that have shed light on sodium-glucose co-transporter 2 inhibitors and glucagon-like peptide 1-receptor agonists and their ability to stabilize blood glucose levels while offering whole-body protection in diabetic and nondiabetic patient populations.
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Affiliation(s)
- Blythe D Shepard
- Department of Human Science, Georgetown University Medical Center, Washington, DC
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24
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Packer M. Differential Pathophysiological Mechanisms in Heart Failure With a Reduced or Preserved Ejection Fraction in Diabetes. JACC-HEART FAILURE 2021; 9:535-549. [PMID: 34325884 DOI: 10.1016/j.jchf.2021.05.019] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 05/17/2021] [Accepted: 05/27/2021] [Indexed: 12/11/2022]
Abstract
Diabetes promotes the development of both heart failure with a reduced ejection fraction and heart failure with a preserved ejection fraction through diverse mechanisms, which are likely mediated through hyperinsulinemia rather than hyperglycemia. Diabetes promotes nutrient surplus signaling (through Akt and mammalian target of rapamycin complex 1) and inhibits nutrient deprivation signaling (through sirtuin-1 and its downstream effectors); this suppresses autophagy and promotes endoplasmic reticulum and oxidative stress and mitochondrial dysfunction, thereby undermining the health of diabetic cardiomyocytes. The hyperinsulinemia of diabetes may also activate sodium-hydrogen exchangers in cardiomyocytes (leading to injury and loss) and in the proximal renal tubules (leading to sodium retention). Diabetes may cause epicardial adipose tissue expansion, and the resulting secretion of proinflammatory adipocytokines onto the adjoining myocardium can lead to coronary microcirculatory dysfunction and myocardial inflammation and fibrosis. Interestingly, sodium-glucose cotransporter 2 (SGLT2) inhibitors-the only class of antidiabetic medication that reduces serious heart failure events-may act to mitigate each of these mechanisms. SGLT2 inhibitors up-regulate sirtuin-1 and its downstream effectors and autophagic flux, thus explaining the actions of these drugs to reduce oxidative stress, normalize mitochondrial structure and function, and mute proinflammatory pathways in the stressed myocardium. Inhibition of SGLT2 may also lead to a reduction in the activity of sodium-hydrogen exchangers in the kidney (leading to diuresis) and in the heart (attenuating the development of cardiac hypertrophy and systolic dysfunction). Finally, SGLT2 inhibitors reduce the mass and mute the adverse biology of epicardial adipose tissue (and reduce the secretion of leptin), thus explaining the capacity of these drugs to mitigate myocardial inflammation, microcirculatory dysfunction, and fibrosis, and improve ventricular filling dynamics. The pathophysiological mechanisms by which SGLT2 inhibitors may benefit heart failure likely differ depending on ejection fraction, but each represents interference with distinct pathways by which hyperinsulinemia may adversely affect cardiac structure and function.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, Texas, USA; Imperial College, London, United Kingdom.
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25
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Sasako T, Tanaka T, Yamauchi T. Adaptive Response as a Potential Key Link Between SGLT2 Inhibition and Renoprotection. Kidney Int Rep 2021; 6:2022-2024. [PMID: 34386649 PMCID: PMC8343789 DOI: 10.1016/j.ekir.2021.05.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Affiliation(s)
- Takayoshi Sasako
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tetsuhiro Tanaka
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Toshimasa Yamauchi
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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26
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Guo C, Xue Y, Sun D, Yin Y, Hu F, Mao S. Transcriptome profiling of hepatic and renal mRNAs and lncRNAs under a nutritional restriction during pregnancy in a sheep model. Genomics 2021; 113:2769-2779. [PMID: 34147634 DOI: 10.1016/j.ygeno.2021.06.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 06/12/2021] [Accepted: 06/15/2021] [Indexed: 11/25/2022]
Abstract
This study aimed to investigate the transcriptome profiles of liver and kidney in pregnant sheep under a nutritional restriction. Twenty Hu sheep were segregated into control group (CON) and severe feed restriction (FR) group. Results showed that the concentration of insulin decreased, whereas glucagon, epinephrine, and norepinephrine increased in the FR group. Histological morphology showed no apparent difference in terms of fat deposition in the kidney. In addition, FR significantly decreased the hepatic gene expression of gluconeogenic genes. However, in the kidney, the relative mRNA expression levels of gluconeogenic genes and glucose transporter 1 were observed to increase while the mRNA expression of sodium-glucose co-transporter 1 were decreased by FR. The differentially expressed genes in the liver were associated with fatty acid metabolism and inflammation. In the kidney, FR mainly activated the gluconeogenesis improving negative energy balance. These results provide a better understanding of the consequences of starvation during pregnancy.
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Affiliation(s)
- Changzheng Guo
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Nanjing Agricultural University, Nanjing 210095, China; National Experimental Teaching Demonstration Center of Animal Science, Nanjing Agricultural University, Nanjing 210095, China; National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, China
| | - Yanfeng Xue
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Nanjing Agricultural University, Nanjing 210095, China; National Experimental Teaching Demonstration Center of Animal Science, Nanjing Agricultural University, Nanjing 210095, China; National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, China
| | - Daming Sun
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Nanjing Agricultural University, Nanjing 210095, China; National Experimental Teaching Demonstration Center of Animal Science, Nanjing Agricultural University, Nanjing 210095, China; National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, China
| | - Yuyang Yin
- Huzhou Academy of Agricultural Sciences, Huzhou 313000, China
| | - Fan Hu
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Nanjing Agricultural University, Nanjing 210095, China; National Experimental Teaching Demonstration Center of Animal Science, Nanjing Agricultural University, Nanjing 210095, China; National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, China
| | - Shengyong Mao
- Laboratory of Gastrointestinal Microbiology, College of Animal Science and Technology, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Key Laboratory of Gastrointestinal Nutrition and Animal Health, Nanjing Agricultural University, Nanjing 210095, China; National Experimental Teaching Demonstration Center of Animal Science, Nanjing Agricultural University, Nanjing 210095, China; National Center for International Research on Animal Gut Nutrition, Nanjing Agricultural University, Nanjing 210095, China; Joint International Research Laboratory of Animal Health and Food Safety, Nanjing Agricultural University, Nanjing 210095, China.
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27
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Sun X, Cao Z, Ma Y, Shao Y, Zhang J, Yuan G, Guo X. Resveratrol attenuates dapagliflozin-induced renal gluconeogenesis via activating the PI3K/Akt pathway and suppressing the FoxO1 pathway in type 2 diabetes. Food Funct 2021; 12:1207-1218. [PMID: 33432947 DOI: 10.1039/d0fo02387f] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Dapagliflozin alleviates hyperglycemia by increasing glycosuria, but it induces renal gluconeogenesis, thus neutralizing its efficacy. Resveratrol (Rsv), a natural polyphenolic chemical, improves insulin sensitivity in type 2 diabetes (T2D). Here, we investigated the regulatory effects and underlying mechanisms of Rsv on dapagliflozin-induced renal gluconeogenesis. Male ob/ob mice were given the vehicle (HF), dapagliflozin (1 mg kg-1), Rsv (10 mg kg-1), or dapagliflozin and Rsv combination for 10 weeks. Glucose metabolism was evaluated by glucose and pyruvate tolerance tests. HK-2 cells (human renal proximal tubule cells) were treated with dapagliflozin (1 μmol L-1) for 2 h and further incubated with Rsv (10 μmol L-1) for 12 h. The effects of Rsv on gluconeogenesis and insulin signaling were assessed. Dapagliflozin treatment increased glucose production in HK-2 cells and lowered blood glucose and induced gluconeogenesis in ob/ob mice. After Rsv treatment, the enhanced glucose production and gluconeogenesis were alleviated. The upregulated mRNA and protein expression of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) and the activation of the forkhead transcription factor O1 (FoxO1) protein in the dapagliflozin group were attenuated by Rsv administration. Rsv also improved renal insulin signaling by increasing PI3K and Akt phosphorylation. The PI3K inhibitor LY294002 dramatically decreased the p-Akt expression and activated FoxO1 by dephosphorylation, thus diminishing the inhibitory effects of Rsv on dapagliflozin-induced PEPCK and G6Pase expression. The data showed the mechanisms of Rsv in attenuating dapagliflozin-induced renal gluconeogenesis via activating the PI3K/Akt pathway and further suppressing FoxO1 activation, suggesting a potential intervention to achieve better glucose-lowering effects for SGLT2 inhibitors in T2D therapy.
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Affiliation(s)
- Xiaoya Sun
- Endocrinology, Peking University First Hospital, Beijing 100034, China.
| | - Ziqiang Cao
- Endocrinology, Peking University First Hospital, Beijing 100034, China.
| | - Yuanyuan Ma
- Animal Center, Peking University First Hospital, Beijing 100034, China
| | - Yimin Shao
- Endocrinology, Peking University First Hospital, Beijing 100034, China.
| | - Junqing Zhang
- Endocrinology, Peking University First Hospital, Beijing 100034, China.
| | - Geheng Yuan
- Endocrinology, Peking University First Hospital, Beijing 100034, China.
| | - Xiaohui Guo
- Endocrinology, Peking University First Hospital, Beijing 100034, China.
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28
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Mathur A, Pandey VK, Khan MF, Kakkar P. PHLPP1/Nrf2-Mdm2 axis induces renal apoptosis via influencing nucleo-cytoplasmic shuttling of FoxO1 during diabetic nephropathy. Mol Cell Biochem 2021; 476:3681-3699. [PMID: 34057658 DOI: 10.1007/s11010-021-04177-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 05/12/2021] [Indexed: 11/30/2022]
Abstract
Impaired PI3K/Akt signaling (insulin resistance) and poor glycemic control (hyperglycemia) are the major risk factors involved in the progression of diabetic nephropathy (DN). This study was designed to identify factors influencing cell survival during DN. We found that high glucose exposure in renal proximal tubular cells (NRK52E) upregulated PHLPP1, an Akt phosphatase (Ser473), causing suppression in Akt and IGF1β phosphorylation leading to inhibition in insulin signaling pathway. Results demonstrate that sustained activation of PHLPP1 promoted nuclear retention of FoxO1 by preventing its ubiquitination via Mdm2, an Akt/ Nrf2-dependent E3 ligase. Thus, enhanced FoxO1 nuclear stability caused aberration in renal gluconeogenesis and activated apoptotic cascade. Conversely, gene silencing of PHLPP1-enhanced Nrf2 expression and attenuated FoxO1 regulated apoptosis compared to hyperglycemic cells. Mechanistic aspects of PHLPP1-Nrf2/FoxO1 signaling were further validated in STZ-nicotinamide-induced type 2 diabetic Wistar rats. Importantly, we observed via immunoblotting and dual immunocytochemical studies that treatment of Morin (2',3,4',5,7-Pentahydroxyflavone) during diabetes significantly augmented FoxO1 nuclear exclusion, resulting in its ubiquitination via Akt-Nrf2/Mdm2 pathway. Furthermore, lowering of PHLPP1 expression by Morin also prevented FoxO1/Mst1-mediated apoptotic signaling in vitro and in vivo. Morin treatment under the experimental conditions, effectively decreased blood glucose levels, ameliorated insulin resistance, alleviated oxidative stress and attenuated renal apoptosis in diabetic rats comparable to metformin thereby exhibiting tremendous potential against renal complications of diabetes. These novel results further acclaim that inhibition of PHLPP1/FoxO1-Mdm2 axis is critical in the pathogenesis of diabetic nephropathy.
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Affiliation(s)
- Alpana Mathur
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India
| | - Vivek Kumar Pandey
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India.,Academy of Scientific and Innovative Research, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Lucknow, 226001, Uttar Pradesh, India
| | - Mohammad Fareed Khan
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India.,Academy of Scientific and Innovative Research, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Lucknow, 226001, Uttar Pradesh, India
| | - Poonam Kakkar
- Herbal Research Laboratory, Food, Drug & Chemical Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan 31, Mahatma Gandhi Marg, Lucknow, 226001, Uttar Pradesh, India. .,Academy of Scientific and Innovative Research, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Lucknow, 226001, Uttar Pradesh, India.
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29
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Akhtar S, Culver SA, Siragy HM. Novel regulation of renal gluconeogenesis by Atp6ap2 in response to high fat diet via PGC1-α/AKT-1 pathway. Sci Rep 2021; 11:11367. [PMID: 34059756 PMCID: PMC8167177 DOI: 10.1038/s41598-021-90952-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 05/18/2021] [Indexed: 12/19/2022] Open
Abstract
Recent studies suggested that renal gluconeogenesis is substantially stimulated in the kidney in presence of obesity. However, the mechanisms responsible for such stimulation are not well understood. Recently, our laboratory demonstrated that mice fed high fat diet (HFD) exhibited increase in renal Atp6ap2 [also known as (Pro)renin receptor] expression. We hypothesized that HFD upregulates renal gluconeogenesis via Atp6ap2-PGC-1α and AKT pathway. Using real-time polymerase chain reaction, western blot analysis and immunostaining, we evaluated renal expression of the Atp6ap2 and renal gluconeogenic enzymes, PEPCK and G6Pase, in wild type and inducible nephron specific Atp6ap2 knockout mice fed normal diet (ND, 12 kcal% fat) or a high-fat diet (HFD, 45 kcal% fat) for 8 weeks. Compared with ND, HFD mice had significantly higher body weight (23%) (P < 0.05), renal mRNA and protein expression of Atp6ap2 (39 and 35%), PEPCK (44 and 125%) and G6Pase (39 and 44%) respectively. In addition, compared to ND, HFD mice had increased renal protein expression of PGC-1α by 32% (P < 0.05) and downregulated AKT by 33% (P < 0.05) respectively in renal cortex. Atp6ap2-KO abrogated these changes in the mice fed HFD. In conclusion, we identified novel regulation of renal gluconeogenesis by Atp6ap2 in response to high fat diet via PGC1-α/AKT-1 pathway.
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Affiliation(s)
- Safia Akhtar
- Department of Medicine, University of Virginia Health System, P.O. Box 801409, Charlottesville, VA, 22903, USA
| | - Silas A Culver
- Department of Medicine, University of Virginia Health System, P.O. Box 801409, Charlottesville, VA, 22903, USA
| | - Helmy M Siragy
- Department of Medicine, University of Virginia Health System, P.O. Box 801409, Charlottesville, VA, 22903, USA.
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30
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Sharma R, Tiwari S. Renal gluconeogenesis in insulin resistance: A culprit for hyperglycemia in diabetes. World J Diabetes 2021; 12:556-568. [PMID: 33995844 PMCID: PMC8107972 DOI: 10.4239/wjd.v12.i5.556] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/27/2021] [Accepted: 04/23/2021] [Indexed: 02/06/2023] Open
Abstract
Renal gluconeogenesis is one of the major pathways for endogenous glucose production. Impairment in this process may contribute to hyperglycemia in cases with insulin resistance and diabetes. We reviewed pertinent studies to elucidate the role of renal gluconeogenesis regulation in insulin resistance and diabetes. A consensus on the suppressive effect of insulin on kidney gluconeogenesis has started to build up. Insulin-resistant models exhibit reduced insulin receptor (IR) expression and/or post-receptor signaling in their kidney tissue. Reduced IR expression or post-receptor signaling can cause impairment in insulin’s action on kidneys, which may increase renal gluconeogenesis in the state of insulin resistance. It is now established that the kidney contributes up to 20% of all glucose production via gluconeogenesis in the post-absorptive phase. However, the rate of renal glucose release excessively increases in diabetes. The rise in renal glucose release in diabetes may contribute to fasting hyperglycemia and increased postprandial glucose levels. Enhanced glucose release by the kidneys and renal expression of the gluconeogenic-enzyme in diabetic rodents and humans further point towards the significance of renal gluconeogenesis. Overall, the available literature suggests that impairment in renal gluconeogenesis in an insulin-resistant state may contribute to hyperglycemia in type 2 diabetes.
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Affiliation(s)
- Rajni Sharma
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
| | - Swasti Tiwari
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow 226014, India
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31
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Al-Yousif N, Rawal S, Jurczak M, Mahmud H, Shah FA. Endogenous Glucose Production in Critical Illness. Nutr Clin Pract 2021; 36:344-359. [PMID: 33682953 DOI: 10.1002/ncp.10646] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Regulation of endogenous glucose production (EGP) by hormonal, neuronal, and metabolic signaling pathways contributes to the maintenance of euglycemia under normal physiologic conditions. EGP is defined by the generation of glucose from substrates through glycogenolysis and gluconeogenesis, usually in fasted states, for local and systemic use. Abnormal increases in EGP are noted in patients with diabetes mellitus type 2, and elevated EGP may also impact the pathogenesis of nonalcoholic fatty liver disease and congestive heart failure. In this narrative review, we performed a literature search in PubMed to identify recently published English language articles characterizing EGP in critical illness. Evidence from preclinical and clinical studies demonstrates that critical illness can disrupt EGP through multiple mechanisms including increased systemic inflammation, counterregulatory hormone and catecholamine release, alterations in the hypothalamic-pituitary axis, insulin resistance, lactic acidosis, and iatrogenic insults such as vasopressors and glucocorticoids administered as part of clinical care. EGP contributes to hyperglycemia in critical illness when abnormally elevated and to hypoglycemia when abnormally depressed, each of which has been independently associated with increased mortality. Increased EGP may also promote protein catabolism that could worsen critical illness myopathy and impede recovery. Better understanding of the mechanisms and factors contributing to dysregulated EGP in critical illness may help in the development of therapeutic strategies that promote euglycemia, reduce intensive care unit-associated catabolism, and improve patient outcomes.
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Affiliation(s)
- Nameer Al-Yousif
- Department of Internal Medicine, UPMC Mercy Hospital, Pittsburgh, Pennsylvania, USA
| | - Sagar Rawal
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Michael Jurczak
- Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Hussain Mahmud
- Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Faraaz Ali Shah
- Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, USA
- Acute Lung Injury Center of Excellence, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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32
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Valdés A, Lucio-Cazaña FJ, Castro-Puyana M, García-Pastor C, Fiehn O, Marina ML. Comprehensive metabolomic study of the response of HK-2 cells to hyperglycemic hypoxic diabetic-like milieu. Sci Rep 2021; 11:5058. [PMID: 33658594 PMCID: PMC7930035 DOI: 10.1038/s41598-021-84590-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 02/16/2021] [Indexed: 01/31/2023] Open
Abstract
Diabetic nephropathy (DN) is the leading cause of chronic kidney disease. Although hyperglycaemia has been determined as the most important risk factor, hypoxia also plays a relevant role in the development of this disease. In this work, a comprehensive metabolomic study of the response of HK-2 cells, a human cell line derived from normal proximal tubular epithelial cells, to hyperglycemic, hypoxic diabetic-like milieu has been performed. Cells simultaneously exposed to high glucose (25 mM) and hypoxia (1% O2) were compared to cells in control conditions (5.5 mM glucose/18.6% O2) at 48 h. The combination of advanced metabolomic platforms (GC-TOF MS, HILIC- and CSH-QExactive MS/MS), freely available metabolite annotation tools, novel databases and libraries, and stringent cut-off filters allowed the annotation of 733 metabolites intracellularly and 290 compounds in the extracellular medium. Advanced bioinformatics and statistical tools demonstrated that several pathways were significantly altered, including carbohydrate and pentose phosphate pathways, as well as arginine and proline metabolism. Other affected metabolites were found in purine and lipid metabolism, the protection against the osmotic stress and the prevention of the activation of the β-oxidation pathway. Overall, the effects of the combined exposure of HK-cells to high glucose and hypoxia are reasonably compatible with previous in vivo works.
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Affiliation(s)
- Alberto Valdés
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España.
- West Coast Metabolomics Center, UC Davis, Davis, CA, USA.
| | - Francisco J Lucio-Cazaña
- Departamento de Biología de Sistemas, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España
| | - María Castro-Puyana
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España
- Instituto de Investigación Química Andrés M del Rio, IQAR, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España
| | - Coral García-Pastor
- Departamento de Biología de Sistemas, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España
| | - Oliver Fiehn
- West Coast Metabolomics Center, UC Davis, Davis, CA, USA
| | - María Luisa Marina
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España.
- Instituto de Investigación Química Andrés M del Rio, IQAR, Universidad de Alcalá, Ctra. Madrid-Barcelona, Km. 33.600, 28871, Alcalá de Henares, Madrid, España.
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Aljaylani A, Fluitt M, Piselli A, Shepard BD, Tiwari S, Ecelbarger CM. Acid Loading Unmasks Glucose Homeostatic Instability in Proximal-Tubule-Targeted Insulin/Insulin-Like-Growth-Factor-1 Receptor Dual Knockout Mice. Cell Physiol Biochem 2021; 54:682-695. [PMID: 32678535 DOI: 10.33594/000000248] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/11/2020] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND/AIMS Metabolic syndrome and type 2 diabetes are associated with some degree of acidosis. Acidosis has also been shown to upregulate renal gluconeogenesis. Whether impaired insulin or insulin-like-growth factor 1 receptor (IGF1) signaling alter this relationship is not known. Our aim was to determine the effects of deletion of insulin and IGF1 receptors (Insr and Igf1r) from renal proximal tubule (PT) on the gluconeogenic response to acidosis. METHODS We developed a mouse model with PT-targeted dual knockout (KO) of the Insr/Igf1r by driving Cre-recombinase with the gamma-glutamyl transferase (gGT) promoter. Male and female mice were maintained as control or acidotic by treatment with NH4Cl in the drinking water for 1-week. RESULTS Acidosis in both genotypes increased renal expression of phosphoenolpyruvate carboxykinase (PEPCK) and fructose-1-bisphosphatase (FBP1), but not glucose-6-phosphatase catalytic subunit (G6PC), which showed significantly lower expression in the KO regardless of treatment. Several differences between KO and WT suggested a protective role for insulin/IGF1 receptor signaling in maintaining relative euglycemia in the face of acidosis. First, the increase in FBP1 with acid was greater in the KO (significant interactive term). Secondly, proximal-tubule-associated FOXO1 and AKT overall protein levels were suppressed by acid loading in the KO, but not in the WT. Robust intact insulin signaling would be needed to reduce gluconeogenesis in PT. Third, phosphorylated FOXO1 (pS256) levels were markedly reduced by acid loading in the KO PT, but not in the WT. This reduction would support greater gluconeogenesis. Fourth, the sodium-glucose cotransporter (SGLT1) was increased by acid loading in the KO kidney, but not the WT. While this would not necessarily affect gluconeogenesis, it could result in increased circulatory glucose via renal reabsorption. Reduced susceptibility to glucose-homeostatic dysregulation in the WT could potentially relate to the sharp (over 50%) reduction in renal levels of sirtuin-1 (SIRT1), which deacetylates and regulates transcription of a number of genes. This reduction was absent in the KO. CONCLUSION Insulin resistance of the kidney may increase whole-body glucose instability a major risk factor for morbidity in diabetes. High dietary acid loads provide a dilemma for the kidney, as ammoniagenesis liberates α-ketoglutarate, which is a substrate for gluconeogenesis. We demonstrate an important role for insulin and/or IGF1 receptor signaling in the PT to facilitate this process and reduce excursions in blood glucose. Thus, medications and lifestyle changes that improve renal insulin sensitivity may also provide added benefit in type 2 diabetes especially when coupled with metabolic acidosis.
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Affiliation(s)
- Abdullah Aljaylani
- Division of Endocrinology and Metabolism, Department of Medicine, Georgetown University, Washington, D.C., USA
| | - Maurice Fluitt
- Division of Endocrinology and Metabolism, Department of Medicine, Georgetown University, Washington, D.C., USA
| | - Alexandra Piselli
- Division of Endocrinology and Metabolism, Department of Medicine, Georgetown University, Washington, D.C., USA
| | - Blythe D Shepard
- School of Nursing and Health Studies, Department of Human Science, Georgetown University, Washington, D.C., USA
| | - Swasti Tiwari
- Department of Molecular Medicine & Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Utter Pradesh, India
| | - Carolyn M Ecelbarger
- Division of Endocrinology and Metabolism, Department of Medicine, Georgetown University, Washington, D.C., USA,
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Fernandes R. The controversial role of glucose in the diabetic kidney. Porto Biomed J 2021; 6:e113. [PMID: 33532655 PMCID: PMC7846417 DOI: 10.1097/j.pbj.0000000000000113] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Accepted: 10/14/2020] [Indexed: 12/31/2022] Open
Abstract
The kidneys play an important role in maintaining glucose homeostasis being the main mechanisms, the gluconeogenesis, renal glucose consumption and glucose reabsorption in the proximal tubules. In this review, we present the main research into the role of glycogen-the stored form of glucose, and how it accumulates in the cells, providing new information on the link between diabetes and diabetic kidney disease. In the last 10 years, research under the scope of renal insulin handling, glucose transport in the proximal tubules, renal gluconeogenesis and renal insulin resistance, made possible to relate the roles of glucose and glycogen in the kidney with other several organs, like the liver. On the one hand, insulin positively regulates kidney uptake and degradation, and there is probably a specific action and resistance to insulin at the renal site. Moreover, insulin regulates the bioavailability of the sodium-glucose co-transporters-SGLT2 inhibitor, and inhibits renal gluconeogenesis. Only the liver and kidneys can supply glucose to the circulation through the process of gluconeogenesis, which involves the synthesis of glucose again from non-glycemic substrates; and the decomposition of stored glycogen. In the mind of nephrologists, diabetologists and scientists, glucose metabolism in the kidney is the focus, with the relevant success of inhibitors in reducing kidney and cardiovascular diseases in individuals with diabetes. However, these new data led to the intriguing paradigm that many of the beneficial effects on the renal and cardiovascular system appear to be independent of the systemic glucose-lowering actions of these agents. The goal of this work puts in context a highly relevant research area for renal glucose metabolism, of glycogen accumulation and metabolism in the diabetic kidney.
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Affiliation(s)
- Rui Fernandes
- Instituto de Inovação e Investigação na Saúde - i3S, Universidade do Porto, Porto, Portugal
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35
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Abstract
Lactic acidosis and hyperlactatemia are common metabolic disturbances in patients with severe malaria. Lactic acidosis causes physiological adverse effects, which can aggravate the outcome of malaria. Despite its clear association with mortality in malaria patients, the etiology of lactic acidosis is not completely understood. In this review, the possible contributors to lactic acidosis and hyperlactatemia in patients with malaria are discussed. Both increased lactate production and impaired lactate clearance may play a role in the pathogenesis of lactic acidosis. The increased lactate production is caused by several factors, including the metabolism of intraerythrocytic Plasmodium parasites, aerobic glycolysis by activated immune cells, and an increase in anaerobic glycolysis in hypoxic cells and tissues as a consequence of parasite sequestration and anemia. Impaired hepatic and renal lactate clearance, caused by underlying liver and kidney disease, might further aggravate hyperlactatemia. Multiple factors thus participate in the etiology of lactic acidosis in malaria, and further investigations are required to fully understand their relative contributions and the consequences of this major metabolic disturbance.
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Affiliation(s)
- Hendrik Possemiers
- Laboratory of Immunoparasitology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven, University of Leuven, Belgium
| | - Leen Vandermosten
- Laboratory of Immunoparasitology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven, University of Leuven, Belgium
| | - Philippe E. Van den Steen
- Laboratory of Immunoparasitology, Department of Microbiology and Immunology, Rega Institute for Medical Research, KU Leuven, University of Leuven, Belgium
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36
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Clark AJ, Parikh SM. Targeting energy pathways in kidney disease: the roles of sirtuins, AMPK, and PGC1α. Kidney Int 2020; 99:828-840. [PMID: 33307105 DOI: 10.1016/j.kint.2020.09.037] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 09/03/2020] [Accepted: 09/09/2020] [Indexed: 12/16/2022]
Abstract
The kidney has extraordinary metabolic demands to sustain the active transport of solutes that is critical to renal filtration and clearance. Mitochondrial health is vital to meet those demands and maintain renal fitness. Decades of studies have linked poor mitochondrial health to kidney disease. Key regulators of mitochondrial health-adenosine monophosphate kinase, sirtuins, and peroxisome proliferator-activated receptor γ coactivator-1α-have all been shown to play significant roles in renal resilience against disease. This review will summarize the latest research into the activities of those regulators and evaluate the roles and therapeutic potential of targeting those regulators in acute kidney injury, glomerular kidney disease, and renal fibrosis.
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Affiliation(s)
- Amanda J Clark
- Division of Nephrology, Boston Children's Hospital, Boston, Massachusetts, USA; Harvard Medical School, Boston, Massachusetts, USA
| | - Samir M Parikh
- Harvard Medical School, Boston, Massachusetts, USA; Division of Nephrology and Center for Vascular Biology Research, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA.
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37
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Legouis D, Faivre A, Cippà PE, de Seigneux S. Renal gluconeogenesis: an underestimated role of the kidney in systemic glucose metabolism. Nephrol Dial Transplant 2020; 37:1417-1425. [PMID: 33247734 DOI: 10.1093/ndt/gfaa302] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Indexed: 12/21/2022] Open
Abstract
Glucose levels are tightly regulated at all times. Gluconeogenesis is the metabolic pathway dedicated to glucose synthesis from non-hexose precursors. Gluconeogenesis is critical for glucose homoeostasis, particularly during fasting or stress conditions. The renal contribution to systemic gluconeogenesis is increasingly recognized. During the post-absorptive phase, the kidney accounts for ∼40% of endogenous gluconeogenesis, occurring mainly in the kidney proximal tubule. The main substrate for renal gluconeogenesis is lactate and the process is regulated by insulin and cellular glucose levels, but also by acidosis and stress hormones. The kidney thus plays an important role in the maintenance of glucose and lactate homoeostasis during stress conditions. The impact of acute and chronic kidney disease and proximal tubular injury on gluconeogenesis is not well studied. Recent evidence shows that in both experimental and clinical acute kidney injury, impaired renal gluconeogenesis could significantly participate in systemic metabolic disturbance and thus alter the prognosis. This review summarizes the biochemistry of gluconeogenesis, the current knowledge of kidney gluconeogenesis, its modifications in kidney disease and the clinical relevance of this fundamental biological process in human biology.
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Affiliation(s)
- David Legouis
- Department of Acute Medicine, Division of Intensive Care, University Hospitals of Geneva, Geneva, Switzerland.,Department of Medicine, Laboratory of Nephrology, University Hospitals of Geneva, Geneva, Switzerland.,Department of Cell Physiology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Anna Faivre
- Department of Medicine, Laboratory of Nephrology, University Hospitals of Geneva, Geneva, Switzerland.,Department of Cell Physiology, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Pietro E Cippà
- Division of Nephrology, Ente Ospedaliero Cantonale, Lugano, Switzerland
| | - Sophie de Seigneux
- Department of Medicine, Laboratory of Nephrology, University Hospitals of Geneva, Geneva, Switzerland.,Department of Cell Physiology, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Department of Medicine, Division of Nephrology, University Hospitals of Geneva, Geneva, Switzerland
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38
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Vallon V. Glucose transporters in the kidney in health and disease. Pflugers Arch 2020; 472:1345-1370. [PMID: 32144488 PMCID: PMC7483786 DOI: 10.1007/s00424-020-02361-w] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Revised: 02/18/2020] [Accepted: 02/20/2020] [Indexed: 02/06/2023]
Abstract
The kidneys filter large amounts of glucose. To prevent the loss of this valuable fuel, the tubular system of the kidney, particularly the proximal tubule, has been programmed to reabsorb all filtered glucose. The machinery involves the sodium-glucose cotransporters SGLT2 and SGLT1 on the apical membrane and the facilitative glucose transporter GLUT2 on the basolateral membrane. The proximal tubule also generates new glucose, particularly in the post-absorptive phase but also to enhance bicarbonate formation and maintain acid-base balance. The glucose reabsorbed or formed by the proximal tubule is primarily taken up into peritubular capillaries and returned to the systemic circulation or provided as an energy source to further distal tubular segments that take up glucose by basolateral GLUT1. Recent studies provided insights on the coordination of renal glucose reabsorption, formation, and usage. Moreover, a better understanding of renal glucose transport in disease states is emerging. This includes the kidney in diabetes mellitus, when renal glucose retention becomes maladaptive and contributes to hyperglycemia. Furthermore, enhanced glucose reabsorption is coupled to sodium retention through the sodium-glucose cotransporter SGLT2, which induces secondary deleterious effects. As a consequence, SGLT2 inhibitors are new anti-hyperglycemic drugs that can protect the kidneys and heart from failing. Recent studies discovered unique roles for SGLT1 with implications in acute kidney injury and glucose sensing at the macula densa. This review discusses established and emerging concepts of renal glucose transport, and outlines the need for a better understanding of renal glucose handling in health and disease.
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Affiliation(s)
- Volker Vallon
- Division of Nephrology and Hypertension, Department of Medicine, University of California San Diego, La Jolla, CA, USA.
- Department of Pharmacology, University of California San Diego, La Jolla, CA, USA.
- VA San Diego Healthcare System, San Diego, CA, USA.
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39
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Pina AF, Borges DO, Meneses MJ, Branco P, Birne R, Vilasi A, Macedo MP. Insulin: Trigger and Target of Renal Functions. Front Cell Dev Biol 2020; 8:519. [PMID: 32850773 PMCID: PMC7403206 DOI: 10.3389/fcell.2020.00519] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 06/02/2020] [Indexed: 12/16/2022] Open
Abstract
Kidney function in metabolism is often underestimated. Although the word “clearance” is associated to “degradation”, at nephron level, proper balance between what is truly degraded and what is redirected to de novo utilization is crucial for the maintenance of electrolytic and acid–basic balance and energy conservation. Insulin is probably one of the best examples of how diverse and heterogeneous kidney response can be. Kidney has a primary role in the degradation of insulin released in the bloodstream, but it is also incredibly susceptible to insulin action throughout the nephron. Fluctuations in insulin levels during fast and fed state add another layer of complexity in the understanding of kidney fine-tuning. This review aims at revisiting renal insulin actions and clearance and to address the association of kidney dysmetabolism with hyperinsulinemia and insulin resistance, both highly prevalent phenomena in modern society.
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Affiliation(s)
- Ana F Pina
- Centro de Estudos de Doenças Crónicas, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.,ProRegeM Ph.D. Programme, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.,Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Diego O Borges
- Centro de Estudos de Doenças Crónicas, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.,Molecular Biosciences Ph.D. Programme, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Maria João Meneses
- Centro de Estudos de Doenças Crónicas, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.,ProRegeM Ph.D. Programme, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Patrícia Branco
- Department of Nephrology, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal.,Portuguese Diabetes Association - Education and Research Center (APDP-ERC), Lisbon, Portugal
| | - Rita Birne
- Department of Nephrology, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal.,Portuguese Diabetes Association - Education and Research Center (APDP-ERC), Lisbon, Portugal
| | - Antonio Vilasi
- Institute of Clinical Physiology - National Research Council, Reggio Calabria Unit1, Reggio Calabria, Italy
| | - Maria Paula Macedo
- Centro de Estudos de Doenças Crónicas, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.,Department of Medical Sciences, University of Aveiro, Aveiro, Portugal.,Portuguese Diabetes Association - Education and Research Center (APDP-ERC), Lisbon, Portugal
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40
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Valdés A, Castro-Puyana M, García-Pastor C, Lucio-Cazaña FJ, Marina ML. Time-series proteomic study of the response of HK-2 cells to hyperglycemic, hypoxic diabetic-like milieu. PLoS One 2020; 15:e0235118. [PMID: 32579601 PMCID: PMC7313754 DOI: 10.1371/journal.pone.0235118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 06/09/2020] [Indexed: 12/13/2022] Open
Abstract
During diabetes, renal proximal tubular cells (PTC) are exposed to a combination of high glucose and hypoxic conditions, which plays a relevant role in the development of diabetic kidney disease (DKD). In this work, a time-series proteomic study was performed to analyse the effect of a diabetic-like microenvironment induced changes on HK-2 cells, a human cell line derived from normal proximal tubular epithelial cells. Cells simultaneously exposed to high glucose (25 mM) and hypoxia (1% O2) were compared to cells in control conditions for up to 48 h. Diabetic conditions increased the percentage of death cells after 24 and 48 h, but no differences in the protein/cell ratio were found. The relative protein quantification using dimethyl-labeling and UHPLC-MS/MS analysis allowed the identification of 317, 296 and 259 proteins at 5, 24 and 48 h, respectively. The combination of statistical and time expression profile analyses indicated an increased expression of proteins involved in glycolysis, and a decrease of cytoskeletal-related proteins. The exposure of HK-2 cells to high glucose and hypoxia reproduces some of the effects of diabetes on PTC and, with the limitations inherent to in vitro studies, propose new mechanisms and targets to be considered in the management of DKD.
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Affiliation(s)
- Alberto Valdés
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Alcalá de Henares, Madrid, España
| | - María Castro-Puyana
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Alcalá de Henares, Madrid, España
- Instituto de Investigación Química Andrés M del Rio, IQAR, Universidad de Alcalá, Alcalá de Henares, Madrid, España
| | - Coral García-Pastor
- Departamento de Biología de Sistemas, Universidad de Alcalá, Alcalá de Henares, Madrid, España
| | | | - María Luisa Marina
- Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Alcalá de Henares, Madrid, España
- Instituto de Investigación Química Andrés M del Rio, IQAR, Universidad de Alcalá, Alcalá de Henares, Madrid, España
- * E-mail:
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41
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Packer M. Role of Deranged Energy Deprivation Signaling in the Pathogenesis of Cardiac and Renal Disease in States of Perceived Nutrient Overabundance. Circulation 2020; 141:2095-2105. [DOI: 10.1161/circulationaha.119.045561] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sodium-glucose cotransporter 2 inhibitors reduce the risk of serious heart failure and adverse renal events, but the mechanisms that underlie this benefit are not understood. Treatment with SGLT2 inhibitors is distinguished by 2 intriguing features: ketogenesis and erythrocytosis. Both reflect the induction of a fasting-like and hypoxia-like transcriptional paradigm that is capable of restoring and maintaining cellular homeostasis and survival. In the face of perceived nutrient and oxygen deprivation, cells activate low-energy sensors, which include sirtuin-1 (SIRT1), AMP-activated protein kinase (AMPK), and hypoxia inducible factors (HIFs; especially HIF-2α); these enzymes and transcription factors are master regulators of hundreds of genes and proteins that maintain cellular homeostasis. The activation of SIRT1 (through its effects to promote gluconeogenesis and fatty acid oxidation) drives ketogenesis, and working in concert with AMPK, it can directly inhibit inflammasome activation and maintain mitochondrial capacity and stability. HIFs act to promote oxygen delivery (by stimulating erythropoietin and erythrocytosis) and decrease oxygen consumption. The activation of SIRT1, AMPK, and HIF-2α enhances autophagy, a lysosome-dependent degradative pathway that removes dangerous constituents, particularly damaged mitochondria and peroxisomes, which are major sources of oxidative stress and triggers of cellular dysfunction and death. SIRT1 and AMPK also act on sodium transport mechanisms to reduce intracellular sodium concentrations. It is interesting that type 2 diabetes mellitus, obesity, chronic heart failure, and chronic kidney failure are characterized by the accumulation of intracellular glucose and lipid intermediates that are perceived by cells as indicators of energy overabundance. The cells respond by downregulating SIRT1, AMPK, and HIF-2α, thus leading to an impairment of autophagic flux and acceleration of cardiomyopathy and nephropathy. SGLT2 inhibitors reverse this maladaptive signaling by triggering a state of fasting and hypoxia mimicry, which includes activation of SIRT1, AMPK, and HIF-2α, enhanced autophagic flux, reduced cellular stress, decreased sodium influx into cells, and restoration of mitochondrial homeostasis. This mechanistic framework clarifies the findings of large-scale randomized trials and the close association of ketogenesis and erythrocytosis with the cardioprotective and renoprotective benefits of these drugs.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, TX. Imperial College, London, United Kingdom
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42
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Packer M. Interplay of adenosine monophosphate-activated protein kinase/sirtuin-1 activation and sodium influx inhibition mediates the renal benefits of sodium-glucose co-transporter-2 inhibitors in type 2 diabetes: A novel conceptual framework. Diabetes Obes Metab 2020; 22:734-742. [PMID: 31916329 DOI: 10.1111/dom.13961] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 12/29/2019] [Accepted: 01/04/2020] [Indexed: 12/11/2022]
Abstract
Long-term treatment with sodium-glucose co-transporter-2 (SGLT2) inhibitors slows the deterioration of renal function in patients with diabetes. This benefit cannot be ascribed to an action on blood glucose, ketone utilization, uric acid or systolic blood pressure. SGLT2 inhibitors produce a striking amelioration of glomerular hyperfiltration. Although initially ascribed to an action of these drugs to inhibit proximal tubular glucose reabsorption, SGLT2 inhibitors exert renoprotective effects, even in patients with meaningfully impaired levels of glomerular function that are sufficient to abolish their glycosuric actions. Instead, the reduction in intraglomerular pressures may be related to an action of SGLT2 inhibitors to interfere with the activity of sodium-hydrogen exchanger isoform 3, thereby inhibiting proximal tubular sodium reabsorption and promoting tubuloglomerular feedback. Yet, experimentally, such an effect may not be sufficient to prevent renal injury. It is therefore noteworthy that the diabetic kidney exhibits an important defect in adenosine monophosphate-activated protein kinase (AMPK) and sirtuin-1 (SIRT1) signalling, which may contribute to the development of nephropathy. These transcription factors exert direct effects to mute oxidative stress and inflammation, and they also stimulate autophagy, a lysosomally mediated degradative pathway that maintains cellular homeostasis in the kidney. SGLT2 inhibitors induce both AMPK and SIRT1, and they have been shown to stimulate autophagy, thereby ameliorating cellular stress and glomerular and tubular injury. Enhanced AMPK/SIRT1 signalling may also contribute to the action of SGLT2 inhibitors to interfere with sodium transport mechanisms. The dual effects of SGLT2 inhibitors on AMPK/SIRT1 activation and renal tubular sodium transport may explain the protective effects of these drugs on the kidney in type 2 diabetes.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, Texas
- Imperial College, London, UK
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43
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Packer M. Role of Impaired Nutrient and Oxygen Deprivation Signaling and Deficient Autophagic Flux in Diabetic CKD Development: Implications for Understanding the Effects of Sodium-Glucose Cotransporter 2-Inhibitors. J Am Soc Nephrol 2020; 31:907-919. [PMID: 32276962 DOI: 10.1681/asn.2020010010] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Growing evidence indicates that oxidative and endoplasmic reticular stress, which trigger changes in ion channels and inflammatory pathways that may undermine cellular homeostasis and survival, are critical determinants of injury in the diabetic kidney. Cells are normally able to mitigate these cellular stresses by maintaining high levels of autophagy, an intracellular lysosome-dependent degradative pathway that clears the cytoplasm of dysfunctional organelles. However, the capacity for autophagy in both podocytes and renal tubular cells is markedly impaired in type 2 diabetes, and this deficiency contributes importantly to the intensity of renal injury. The primary drivers of autophagy in states of nutrient and oxygen deprivation-sirtuin-1 (SIRT1), AMP-activated protein kinase (AMPK), and hypoxia-inducible factors (HIF-1α and HIF-2α)-can exert renoprotective effects by promoting autophagic flux and by exerting direct effects on sodium transport and inflammasome activation. Type 2 diabetes is characterized by marked suppression of SIRT1 and AMPK, leading to a diminution in autophagic flux in glomerular podocytes and renal tubules and markedly increasing their susceptibility to renal injury. Importantly, because insulin acts to depress autophagic flux, these derangements in nutrient deprivation signaling are not ameliorated by antihyperglycemic drugs that enhance insulin secretion or signaling. Metformin is an established AMPK agonist that can promote autophagy, but its effects on the course of CKD have been demonstrated only in the experimental setting. In contrast, the effects of sodium-glucose cotransporter-2 (SGLT2) inhibitors may be related primarily to enhanced SIRT1 and HIF-2α signaling; this can explain the effects of SGLT2 inhibitors to promote ketonemia and erythrocytosis and potentially underlies their actions to increase autophagy and mute inflammation in the diabetic kidney. These distinctions may contribute importantly to the consistent benefit of SGLT2 inhibitors to slow the deterioration in glomerular function and reduce the risk of ESKD in large-scale randomized clinical trials of patients with type 2 diabetes.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, Texas .,Imperial College, London, United Kingdom
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Packer M. Critical examination of mechanisms underlying the reduction in heart failure events with SGLT2 inhibitors: identification of a molecular link between their actions to stimulate erythrocytosis and to alleviate cellular stress. Cardiovasc Res 2020; 117:74-84. [PMID: 32243505 DOI: 10.1093/cvr/cvaa064] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/10/2020] [Accepted: 03/30/2020] [Indexed: 12/13/2022] Open
Abstract
Sodium-glucose co-transporter 2 (SGLT2) inhibitors reduce the risk of serious heart failure events, even though SGLT2 is not expressed in the myocardium. This cardioprotective benefit is not related to an effect of these drugs to lower blood glucose, promote ketone body utilization or enhance natriuresis, but it is linked statistically with their action to increase haematocrit. SGLT2 inhibitors increase both erythropoietin and erythropoiesis, but the increase in red blood cell mass does not directly prevent heart failure events. Instead, erythrocytosis is a biomarker of a state of hypoxia mimicry, which is induced by SGLT2 inhibitors in manner akin to cobalt chloride. The primary mediators of the cellular response to states of energy depletion are sirtuin-1 and hypoxia-inducible factors (HIF-1α/HIF-2α). These master regulators promote the cellular adaptation to states of nutrient and oxygen deprivation, promoting mitochondrial capacity and minimizing the generation of oxidative stress. Activation of sirtuin-1 and HIF-1α/HIF-2α also stimulates autophagy, a lysosome-mediated degradative pathway that maintains cellular homoeostasis by removing dangerous constituents (particularly unhealthy mitochondria and peroxisomes), which are a major source of oxidative stress and cardiomyocyte dysfunction and demise. SGLT2 inhibitors can activate SIRT-1 and stimulate autophagy in the heart, and thereby, favourably influence the course of cardiomyopathy. Therefore, the linkage between erythrocytosis and the reduction in heart failure events with SGLT2 inhibitors may be related to a shared underlying molecular mechanism that is triggered by the action of these drugs to induce a perceived state of oxygen and nutrient deprivation.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, 621 N. Hall Street, Dallas, TX 75226, USA.,Imperial College, London, UK
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Packer M. Autophagy stimulation and intracellular sodium reduction as mediators of the cardioprotective effect of sodium-glucose cotransporter 2 inhibitors. Eur J Heart Fail 2020; 22:618-628. [PMID: 32037659 DOI: 10.1002/ejhf.1732] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 11/26/2019] [Accepted: 11/28/2019] [Indexed: 12/17/2022] Open
Abstract
In five large-scale trials involving >40 000 patients, sodium-glucose cotransporter 2 (SGLT2) inhibitors decreased the risk of serious heart failure events by 25-40%. This effect cannot be explained by control of hyperglycaemia, since it is not observed with antidiabetic drugs with greater glucose-lowering effects. It cannot be attributed to ketogenesis, since it is not causally linked to ketone body production, and the benefit is not enhanced in patients with diabetes. The effect cannot be ascribed to a natriuretic action, since SGLT2 inhibitors decrease natriuretic peptides only modestly, and they reduce cardiovascular death, a benefit that diuretics do not possess. Although SGLT2 inhibitors increase red blood cell mass, enhanced erythropoiesis does not favourably influence the course of heart failure. By contrast, experimental studies suggest that SGLT2 inhibitors may reduce intracellular sodium, thereby preventing oxidative stress and cardiomyocyte death. Additionally, SGLT2 inhibitors induce a transcriptional paradigm that mimics nutrient and oxygen deprivation, which includes activation of adenosine monophosphate-activated protein kinase, sirtuin-1, and/or hypoxia-inducible factors-1α/2α. The interplay of these mediators stimulates autophagy, a lysosomally-mediated degradative pathway that maintains cellular homeostasis. Autophagy-mediated clearance of damaged organelles reduces inflammasome activation, thus mitigating cardiomyocyte dysfunction and coronary microvascular injury. Interestingly, the action of hypoxia-inducible factors-1α/2α to both stimulate erythropoietin and induce autophagy may explain why erythrocytosis is strongly correlated with the reduction in heart failure events. Therefore, the benefits of SGLT2 inhibitors on heart failure may be mediated by a direct cardioprotective action related to modulation of pathways responsible for cardiomyocyte homeostasis.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, TX, USA.,Imperial College, London, UK
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Sharma R, Kumari M, Prakash P, Gupta S, Tiwari S. Phosphoenolpyruvate carboxykinase in urine exosomes reflect impairment in renal gluconeogenesis in early insulin resistance and diabetes. Am J Physiol Renal Physiol 2020; 318:F720-F731. [PMID: 32036699 DOI: 10.1152/ajprenal.00507.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Impaired insulin-induced suppression of renal gluconeogenesis could be a risk for hyperglycemia. Diabetes is associated with elevated renal gluconeogenesis; however, its regulation in early insulin resistance is unclear in humans. A noninvasive marker of renal gluconeogenesis would be helpful. Here, we show that human urine exosomes (uE) contain three gluconeogenic enzymes: phosphoenolpyruvate carboxykinase (PEPCK), fructose 1,6-bisphosphatase, and glucose 6-phosphatase. Their protein levels were positively associated with whole body insulin sensitivity. PEPCK protein in uE exhibited a meal-induced suppression. However, subjects with lower insulin sensitivity had blunted meal-induced suppression. Also, uE from subjects with prediabetes and diabetic rats had higher PEPCK relative to nondiabetic controls. Moreover, uE-PEPCK was higher in drug-naïve subjects with diabetes relative to drug-treated subjects with diabetes. To determine whether increased renal gluconeogenesis is associated with hyperglycemia or PEPCK expression in uE, acidosis was induced in rats by 0.28 M NH4Cl with 0.5% sucrose in drinking water. Control rats were maintained on 0.5% sucrose. At the seventh day posttreatment, gluconeogenic enzyme activity in the kidneys, but not in the liver, was higher in acidotic rats. These rats had elevated PEPCK in their uE and a significant rise in blood glucose relative to controls. The induction of gluconeogenesis in human proximal tubule cells increased PEPCK expression in both human proximal tubules and human proximal tubule-secreted exosomes in the media. Overall, gluconeogenic enzymes are detectable in human uE. Elevated PEPCK and its blunted meal-induced suppression in human urine exosomes are associated with diabetes and early insulin resistance.
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Affiliation(s)
- Rajni Sharma
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Manju Kumari
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Prem Prakash
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Sushil Gupta
- Department of Endocrinology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | - Swasti Tiwari
- Department of Molecular Medicine and Biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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Pereira-Moreira R, Muscelli E. Effect of Insulin on Proximal Tubules Handling of Glucose: A Systematic Review. J Diabetes Res 2020; 2020:8492467. [PMID: 32377524 PMCID: PMC7180501 DOI: 10.1155/2020/8492467] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 12/18/2019] [Accepted: 12/27/2019] [Indexed: 02/06/2023] Open
Abstract
Renal proximal tubules reabsorb glucose from the glomerular filtrate and release it back into the circulation. Modulation of glomerular filtration and renal glucose disposal are some of the insulin actions, but little is known about a possible insulin effect on tubular glucose reabsorption. This review is aimed at synthesizing the current knowledge about insulin action on glucose handling by proximal tubules. Method. A systematic article selection from Medline (PubMed) and Embase between 2008 and 2019. 180 selected articles were clustered into topics (renal insulin handling, proximal tubule glucose transport, renal gluconeogenesis, and renal insulin resistance). Summary of Results. Insulin upregulates its renal uptake and degradation, and there is probably a renal site-specific insulin action and resistance; studies in diabetic animal models suggest that insulin increases renal SGLT2 protein content; in vivo human studies on glucose transport are few, and results of glucose transporter protein and mRNA contents are conflicting in human kidney biopsies; maximum renal glucose reabsorptive capacity is higher in diabetic patients than in healthy subjects; glucose stimulates SGLT1, SGLT2, and GLUT2 in renal cell cultures while insulin raises SGLT2 protein availability and activity and seems to directly inhibit the SGLT1 activity despite it activating this transporter indirectly. Besides, insulin regulates SGLT2 inhibitor bioavailability, inhibits renal gluconeogenesis, and interferes with Na+K+ATPase activity impacting on glucose transport. Conclusion. Available data points to an important insulin participation in renal glucose handling, including tubular glucose transport, but human studies with reproducible and comparable method are still needed.
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Affiliation(s)
- Ricardo Pereira-Moreira
- Department of Internal Medicine, School of Medical Sciences, University of Campinas, Zip Code: 13083-887, Brazil
| | - Elza Muscelli
- Department of Internal Medicine, School of Medical Sciences, University of Campinas, Zip Code: 13083-887, Brazil
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Li X, Zheng S, Wu G. Amino Acid Metabolism in the Kidneys: Nutritional and Physiological Significance. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1265:71-95. [DOI: 10.1007/978-3-030-45328-2_5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Li L, Zhao H, Chen B, Fan Z, Li N, Yue J, Ye Q. FXR activation alleviates tacrolimus-induced post-transplant diabetes mellitus by regulating renal gluconeogenesis and glucose uptake. J Transl Med 2019; 17:418. [PMID: 31836014 PMCID: PMC6909577 DOI: 10.1186/s12967-019-02170-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Accepted: 12/05/2019] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Tacrolimus (FK506)-induced diabetes mellitus is one of the most important factors of post-transplant diabetes mellitus (PTDM). However, the detailed mechanisms underlying PTDM are still unclear. Farnesoid X receptor (FXR) regulates glycolipid metabolism. The objective of this study was to explore whether FXR is involved in the development of tacrolimus-induced diabetes mellitus. METHODS After C57BL/6J mice were treated with tacrolimus (FK506) for 3 months, the fasting blood glucose levels, body weights, renal morphological alterations, and mRNA expression levels of phosphoenolpyruvate carboxykinase (PEPCK) and glucose transporter 2 (GLUT2) among the control group, the FK506 group and the FK506 + GW4064 (a FXR agonist) group (n = 7) were measured. The intracellular location of peroxisome proliferator activated receptor γ coactivator-1α (PGC1α) and forkhead box O1 (FOXO1) was detected by immunofluorescence. Human renal cortex proximal tubule epithelial cells (HK-2) were treated with 15 μM FK506 or 4 μM FXR agonist (GW4064) for 24, 48 and 72 h, and the expression levels of FXR, gluconeogenesis and glucose uptake, representing the enzymes PEPCK and GLUT2, were detected with real-time PCR and western blot analyses. Finally, the mRNA levels of PEPCK and GLUT2 in HK-2 cells were measured after FXR was upregulated. RESULTS FK506 significantly inhibited the mRNA and protein levels of FXR at 48 h and 72 h in HK-2 cells (P < 0.05). Meanwhile, FK506 promoted gluconeogenesis and inhibited glucose uptake in HK-2 cells (P < 0.05). However, overexpression of FXR in transfected HK-2 cell lines significantly inhibited gluconeogenesis and promoted glucose uptake (P < 0.05). The FXR agonist GW4064 significantly decreased the fasting blood glucose in mice challenged with FK506 for 3 months (P < 0.05), inhibited gluconeogenesis (P < 0.05) and significantly promoted glucose uptake (P < 0.05). Immunofluorescence staining and western blot analyses further revealed that FXR activation may affect the translocation of PGC1α and FOXO1 from the nucleus to the cytoplasm. CONCLUSIONS FXR activation may mitigate tacrolimus-induced diabetes mellitus by regulating gluconeogenesis as well as glucose uptake of renal cortex proximal tubule epithelial cells in a PGC1α/FOXO1-dependent manner, which may be a potential therapeutic strategy for the prevention and treatment of PTDM.
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Affiliation(s)
- Ling Li
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Hubei Key Laboratory of Medical Technology on Transplantation, Wuhan, 430071, Hubei, People's Republic of China
| | - Huijia Zhao
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Hubei Key Laboratory of Medical Technology on Transplantation, Wuhan, 430071, Hubei, People's Republic of China
| | - Binyao Chen
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Hubei Key Laboratory of Medical Technology on Transplantation, Wuhan, 430071, Hubei, People's Republic of China
| | - Zhipeng Fan
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Hubei Key Laboratory of Medical Technology on Transplantation, Wuhan, 430071, Hubei, People's Republic of China
| | - Ning Li
- Department of Cardiology, Renmin Hospital of Wuhan University, Cardiovascular Research Institute, Hubei Key Laboratory of Cardiology, Wuhan University, Jiefang Road 238, Wuhan, 430060, People's Republic of China.
| | - Jiang Yue
- Department of Pharmacology, Basic Medical School of Wuhan University, Wuhan, 430071, People's Republic of China.
| | - Qifa Ye
- Zhongnan Hospital of Wuhan University, Institute of Hepatobiliary Diseases of Wuhan University, Transplant Center of Wuhan University, Hubei Key Laboratory of Medical Technology on Transplantation, Wuhan, 430071, Hubei, People's Republic of China. .,The 3rd Xiangya Hospital of Central South University, Research Center of National Health Ministry on Transplantation Medicine Engineering and Technology, Changsha, 410013, People's Republic of China.
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Inaba Y, Hashiuchi E, Watanabe H, Kimura K, Sato M, Kobayashi M, Matsumoto M, Kitamura T, Kasuga M, Inoue H. Hepatic Gluconeogenic Response to Single and Long-Term SGLT2 Inhibition in Lean/Obese Male Hepatic G6pc-Reporter Mice. Endocrinology 2019; 160:2811-2824. [PMID: 31517956 DOI: 10.1210/en.2019-00422] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 09/05/2019] [Indexed: 02/04/2023]
Abstract
Sodium-glucose cotransporter 2 inhibitor (SGLT2i) consistently reduces blood glucose levels in type 2 diabetes mellitus but increases hepatic gluconeogenic gene expression and glucose production, offsetting its glucose-lowering effect. This study aimed to elucidate the effect of SGLT2i on hepatic gluconeogenic response and its mechanism in both insulin-sensitive and insulin-resistant states. A hepatic mouse model was generated to show liver-specific expression of Gaussia luciferase (GLuc) driven by the gluconeogenic enzyme gene G6pc promoter. Hepatic gluconeogenic response was evaluated by measuring plasma GLuc activity. SGLT2i was given to lean and obese mice in single gavage administration or 4-week dietary administration with controlled feeding every 3 hours. In lean mice, single-dose SGLT2i increased plasma GLuc activity from 2 hours after administration, decreasing blood glucose and plasma insulin from 1 to 2 hours after administration. In obese mice, which had higher plasma GLuc activity than lean ones, SGLT2i did not further increase GLuc activity despite decreased blood glucose and plasma insulin. Hepatic Akt and GSK3β phosphorylation was attenuated by single-dose SGLT2i in lean mice in accordance with the plasma insulin decrease, but not in obese mice. Long-term SGLT2i administration, which increased plasma GLuc activity in lean mice, decreased it in obese mice from 3 weeks after initiation, with increased hepatic Akt and GSK3β phosphorylation. In conclusion, single SGLT2i administration increases hepatic gluconeogenic response in lean insulin-sensitive mice, but not in obese insulin-resistant mice. Long-term SGLT2i administration relieves obesity-induced upregulation of the hepatic gluconeogenic response by restoring impeded hepatic insulin signaling in obese insulin-resistant mice.
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Affiliation(s)
- Yuka Inaba
- Metabolism and Nutrition Research Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Emi Hashiuchi
- Department of Physiology and Metabolism, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hitoshi Watanabe
- Metabolism and Nutrition Research Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Kumi Kimura
- Metabolism and Nutrition Research Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Makoto Sato
- Mathematical Neuroscience Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan
- Laboratory of Developmental Neurobiology, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Masaki Kobayashi
- Laboratory for Metabolic Signaling, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma, Japan
| | - Michihiro Matsumoto
- Department of Molecular Metabolic Regulation, Diabetes Research Center, Research Institute, National Center for Global Health and Medicine, Tokyo, Japan
| | - Tadahiro Kitamura
- Laboratory for Metabolic Signaling, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma, Japan
| | - Masato Kasuga
- The Institute for Adult Diseases, Asahi Life Foundation, Tokyo, Japan
| | - Hiroshi Inoue
- Metabolism and Nutrition Research Unit, Institute for Frontier Science Initiative, Kanazawa University, Kanazawa, Ishikawa, Japan
- Department of Physiology and Metabolism, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, Japan
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