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Laouari D, Vergnaud P, Hirose T, Zaidan M, Rabant M, Nguyen C, Burtin M, Legendre C, Codogno P, Friedlander G, Anglicheau D, Terzi F. The sexual dimorphism of kidney growth in mice and humans. Kidney Int 2022; 102:78-95. [PMID: 35337891 DOI: 10.1016/j.kint.2022.02.027] [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: 04/30/2021] [Revised: 02/02/2022] [Accepted: 02/16/2022] [Indexed: 10/18/2022]
Abstract
Kidney mass and function are sexually determined, but the cellular events and the molecular mechanisms involved in this dimorphism are poorly characterized. By combining female and male mice with castration/replacement experiments, we showed that male mice exhibited kidney overgrowth from five weeks of age. This effect was organ specific, since liver and heart weight were comparable between males and females, regardless of age. Consistently, the androgen receptor was found to be expressed in the kidneys of males, but not in the liver. In growing mice, androgens led to kidney overgrowth by first inducing a burst of cell proliferation and then an increase of cell size. Remarkably, androgens were also required to maintain cell size in adults. In fact, orchiectomy resulted in smaller kidneys in a matter of few weeks. These changes paralleled the changes of the expression of ornithine decarboxylase and cyclin D1, two known mediators of kidney growth, whereas, unexpectedly, mTORC1 and Hippo pathways did not seem to be involved. Androgens also enhanced kidney autophagy, very likely by increasing transcription factor EB nuclear translocation. Functionally, the increase of tubular mass resulted in increased sodium/phosphate transport. These findings were relevant to humans. Remarkably, by studying living gender-paired kidney donors-recipients, we showed that tubular cell size increased three months after transplantation in men as compared to women, regardless of the donor gender. Thus, our results identify novel signaling pathways that may be involved in androgen-induced kidney growth and homeostasis, and suggest that androgens determine kidney size after transplantation.
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Affiliation(s)
- Denise Laouari
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France
| | - Paul Vergnaud
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France; Service de Néphrologie Pédiatrique-Hémodialyse-Transplantation, AP-HP, Hôpital Necker, Paris, France
| | - Takuo Hirose
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France
| | - Mohamad Zaidan
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France; Service de Néphrologie-Transplantation, AP-HP, Hôpital Bicêtre, Le Kremlin-Bicêtre, France
| | - Marion Rabant
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France; Service d'Anatomo-Pathologie, AP-HP, Hôpital Necker, Paris, France
| | - Clément Nguyen
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France
| | - Martine Burtin
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France
| | - Christophe Legendre
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France; Service de Néphrologie-Transplantation, AP-HP, Hôpital Necker, Paris, France
| | - Patrice Codogno
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France
| | - Gerard Friedlander
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France
| | - Dany Anglicheau
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France; Service de Néphrologie-Transplantation, AP-HP, Hôpital Necker, Paris, France
| | - Fabiola Terzi
- Université de Paris, INSERM U1151, CNRS UMR 8253, Institut Necker Enfants Malades (INEM), Département « Croissance et Signalisation », F-75006 Paris, France.
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Characterization of Enlarged Kidneys and Their Potential for Inducing Diabetes in DEK Rats. BIOLOGY 2021; 10:biology10070633. [PMID: 34356489 PMCID: PMC8301011 DOI: 10.3390/biology10070633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/02/2021] [Accepted: 07/06/2021] [Indexed: 11/16/2022]
Abstract
The kidneys participate in the regulation of systemic glucose metabolism via gluconeogenesis, insulin degradation, and the tubular reabsorption of glucose. The present study characterized rats from a strain of a novel type 2 diabetes model with enlarged kidneys (DEK). Histological and biochemical analyses of DEK rats were performed to assess the relationships between their kidneys and hyperglycemia. The kidney weight of diabetic DEK (DEK-DM) gradually increased over time from the onset of diabetes, with the glomerular number being higher in DEK-DM than in normal DEK (DEK-cont). A positive correlation between blood glucose level and kidney weight was observed in DEK-DM. The similar glomerular size and single glomerular creatinine clearance in DEK-cont and DEK-DM indicated that glomerular hypertrophy and hyperfiltration were not involved in the renal enlargement. Uninephrectomy (1/2Nx) in DEK-DM resulted in a reduction in blood glucose level at 7-28 post-operation days, with this concentration remaining lower than in Sham group until 84 days post-operation. 1/2Nx also improved systemic conditions, including reduced body weight gain, polyuria, polydipsia, and hyperphagia. Plasma concentrations of Na, total cholesterol, albumin, and total protein were higher, and urinary excretion of glucose, urea nitrogen, and proteins were lower, in the 1/2Nx than in the Sham group. Remnant kidney weight was two-fold higher in the 1/2Nx than in the Sham group 84 days later. In addition, 1/2Nx resulted in renal tubular dilatation but not in the progression of fibrosis or glomerular lesions. Taken together, these findings indicate that enlarged kidneys were associated with the onset of diabetes and with the resistance to diabetic nephropathy in DEK-DM.
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High glucose-stimulated enhancer of zeste homolog-2 (EZH2) forces suppression of deptor to cause glomerular mesangial cell pathology. Cell Signal 2021; 86:110072. [PMID: 34224844 DOI: 10.1016/j.cellsig.2021.110072] [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: 05/21/2021] [Revised: 06/23/2021] [Accepted: 06/29/2021] [Indexed: 11/24/2022]
Abstract
Function of mTORC1 and mTORC2 has emerged as a driver of mesangial cell pathologies in diabetic nephropathy. The mechanism of mTOR activation is poorly understood in this disease. Deptor is a constitutive subunit and a negative regulator of both mTOR complexes. Mechanistic investigation in mesangial cells revealed that high glucose decreased the expression of deptor concomitant with increased mTORC1 and mTORC2 activities, induction of hypertrophy and, expression of fibronectin and PAI-1. shRNAs against deptor mimicked these pathologic outcomes of high glucose. Conversely, overexpression of deptor significantly inhibited all effects of high glucose. To determine the mechanism of deptor suppression, we found that high glucose significantly increased the expression of EZH2, resulting in lysine-27 tri-methylation of histone H3 (H3K27Me3). Employing approaches including pharmacological inhibition, shRNA-mediated downregulation and overexpression of EZH2, we found that EZH2 regulates high glucose-induced deptor suppression along with activation of mTOR, mesangial cell hypertrophy and fibronectin/PAI-1 expression. Moreover, expression of hyperactive mTORC1 reversed shEZH2-mediated inhibition of hypertrophy and expression of fibronectin and PAI-1 by high glucose. Finally, in renal cortex of diabetic mice, we found that enhanced expression of EZH2 is associated with decreased deptor levels and increased mTOR activity and, expression of fibronectin and PAI-1. Together, our findings provide a novel mechanism for mTOR activation via EZH2 to induce mesangial cell hypertrophy and matrix expansion during early progression of diabetic nephropathy. These results suggest a strategy for leveraging the intrinsic effect of deptor to suppress mTOR activity via reducing EZH2 as a novel therapy for diabetic nephropathy.
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Ma Z, Li L, Livingston MJ, Zhang D, Mi Q, Zhang M, Ding HF, Huo Y, Mei C, Dong Z. p53/microRNA-214/ULK1 axis impairs renal tubular autophagy in diabetic kidney disease. J Clin Invest 2021; 130:5011-5026. [PMID: 32804155 DOI: 10.1172/jci135536] [Citation(s) in RCA: 113] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 06/17/2020] [Indexed: 01/12/2023] Open
Abstract
Dysregulation of autophagy in diabetic kidney disease (DKD) has been reported, but the underlying mechanism and its pathogenic role remain elusive. We show that autophagy was inhibited in DKD models and in human diabetic kidneys. Ablation of autophagy-related gene 7 (Atg7) from kidney proximal tubules led to autophagy deficiency and worse renal hypertrophy, tubular damage, inflammation, fibrosis, and albuminuria in diabetic mice, indicating a protective role of autophagy in DKD. Autophagy impairment in DKD was associated with the downregulation of unc-51-like autophagy-activating kinase 1 (ULK1), which was mediated by the upregulation of microRNA-214 (miR-214) in diabetic kidney cells and tissues. Ablation of miR-214 from kidney proximal tubules prevented a decrease in ULK1 expression and autophagy impairment in diabetic kidneys, resulting in less renal hypertrophy and albuminuria. Furthermore, blockade of p53 attenuated miR-214 induction in DKD, leading to higher levels of ULK1 and autophagy, accompanied by an amelioration of DKD. Compared with nondiabetic samples, renal biopsies from patients with diabetes showed induction of p53 and miR-214, associated with downregulation of ULK1 and autophagy. We found a positive correlation between p53/miR-214 and renal fibrosis, but a negative correlation between ULK1/LC3 and renal fibrosis in patients with diabetes. Together, these results identify the p53/miR-214/ULK1 axis in autophagy impairment in diabetic kidneys, pinpointing possible therapeutic targets for DKD.
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Affiliation(s)
- Zhengwei Ma
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Lin Li
- Department of Nephrology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Man J Livingston
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Dongshan Zhang
- Department of Emergency Medicine, Second Xiangya Hospital at Central South University, Changsha, China
| | - Qingsheng Mi
- Center for Cutaneous Biology and Immunology Research, Department of Dermatology, Henry Ford Health System, Detroit, Michigan, USA
| | - Ming Zhang
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | | | - Yuqing Huo
- Vascular Biology Center, Medical College of Georgia at Augusta University, Augusta, Georgia, USA
| | - Changlin Mei
- Department of Nephrology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Zheng Dong
- Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, Georgia, USA.,Charlie Norwood VA Medical Center, Augusta, Georgia, USA
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Lake JA, Papah MB, Abasht B. Increased Expression of Lipid Metabolism Genes in Early Stages of Wooden Breast Links Myopathy of Broilers to Metabolic Syndrome in Humans. Genes (Basel) 2019; 10:E746. [PMID: 31557856 PMCID: PMC6826700 DOI: 10.3390/genes10100746] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 09/20/2019] [Indexed: 12/20/2022] Open
Abstract
Wooden breast is a muscle disorder affecting modern commercial broiler chickens that causes a palpably firm pectoralis major muscle and severe reduction in meat quality. Most studies have focused on advanced stages of wooden breast apparent at market age, resulting in limited insights into the etiology and early pathogenesis of the myopathy. Therefore, the objective of this study was to identify early molecular signals in the wooden breast transcriptional cascade by performing gene expression analysis on the pectoralis major muscle of two-week-old birds that may later exhibit the wooden breast phenotype by market age at 7 weeks. Biopsy samples of the left pectoralis major muscle were collected from 101 birds at 14 days of age. Birds were subsequently raised to 7 weeks of age to allow sample selection based on the wooden breast phenotype at market age. RNA-sequencing was performed on 5 unaffected and 8 affected female chicken samples, selected based on wooden breast scores (0 to 4) assigned at necropsy where affected birds had scores of 2 or 3 (mildly or moderately affected) while unaffected birds had scores of 0 (no apparent gross lesions). Differential expression analysis identified 60 genes found to be significant at an FDR-adjusted p-value of 0.05. Of these, 26 were previously demonstrated to exhibit altered expression or genetic polymorphisms related to glucose tolerance or diabetes mellitus in mammals. Additionally, 9 genes have functions directly related to lipid metabolism and 11 genes are associated with adiposity traits such as intramuscular fat and body mass index. This study suggests that wooden breast disease is first and foremost a metabolic disorder characterized primarily by ectopic lipid accumulation in the pectoralis major.
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Affiliation(s)
- Juniper A Lake
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19711, USA.
| | - Michael B Papah
- Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716, USA.
| | - Behnam Abasht
- Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716, USA.
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Maity S, Das F, Ghosh-Choudhury N, Kasinath BS, Ghosh Choudhury G. High glucose increases miR-214 to power a feedback loop involving PTEN and the Akt/mTORC1 signaling axis. FEBS Lett 2019; 593:2261-2272. [PMID: 31240704 DOI: 10.1002/1873-3468.13505] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/12/2019] [Accepted: 06/16/2019] [Indexed: 12/20/2022]
Abstract
The mechanism of PTEN repression by high glucose in diabetic nephropathy is not known. Using proximal tubular cells, we show that inhibition of PI3 kinase/Akt and their inactive enzymes prevents high glucose-induced PTEN downregulation. Similarly, rapamycin (Rapa) and shRaptor block suppression of PTEN by high glucose. In contrast, the constitutive activation of Akt and mechanistic target of rapamycin (mTOR)C1 decrease the expression of PTEN, similarly to high glucose. Remarkably, PI3 kinase/Akt/mTORC1 inhibition significantly attenuates high glucose-stimulated increase in miR-214, which targets PTEN, while constitutively active Akt/mTORC1 increases miR-214. Furthermore, anti-miR-214 and mTORC1 inhibition block high glucose-induced hypertrophy and fibronectin expression. These results reveal the first evidence for the presence of a high glucose-forced positive feedback conduit between the three-layered kinase cascade and miR-214/ PTEN in tubular cell injury.
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Affiliation(s)
- Soumya Maity
- Department of Medicine, UT Health San Antonio, TX, USA
| | - Falguni Das
- Department of Medicine, UT Health San Antonio, TX, USA
| | - Nandini Ghosh-Choudhury
- VA Biomedical Laboratory Research and Development, South Texas Veterans Health Care System, San Antonio, TX, USA.,Department of Pathology, UT Health San Antonio, San Antonio, TX, USA
| | - Balakuntalam S Kasinath
- Department of Medicine, UT Health San Antonio, TX, USA.,VA Biomedical Laboratory Research and Development, South Texas Veterans Health Care System, San Antonio, TX, USA
| | - Goutam Ghosh Choudhury
- Department of Medicine, UT Health San Antonio, TX, USA.,VA Biomedical Laboratory Research and Development, South Texas Veterans Health Care System, San Antonio, TX, USA.,Geriatric Research, Education and Clinical Research, South Texas Veterans Health Care System, San Antonio, TX, USA
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Das F, Maity S, Ghosh-Choudhury N, Kasinath BS, Ghosh Choudhury G. Deacetylation of S6 kinase promotes high glucose-induced glomerular mesangial cell hypertrophy and matrix protein accumulation. J Biol Chem 2019; 294:9440-9460. [PMID: 31028173 DOI: 10.1074/jbc.ra118.007023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 04/09/2019] [Indexed: 12/30/2022] Open
Abstract
S6 kinase acts as a driver for renal hypertrophy and matrix accumulation, two key pathologic signatures of diabetic nephropathy. As a post-translational modification, S6 kinase undergoes acetylation at the C terminus. The role of this acetylation to regulate kidney glomerular cell hypertrophy and matrix expansion is not known. In mesangial cells, high glucose decreased the acetylation and enhanced phosphorylation of S6 kinase and its substrates rps6 and eEF2 kinase that lead to dephosphorylation of eEF2. To determine the mechanism of S6 kinase deacetylation, we found that trichostatin A, a pan-histone deacetylase (HDAC) inhibitor, blocked all high glucose-induced effects. Furthermore, high glucose increased the expression and association of HDAC1 with S6 kinase. HDAC1 decreased the acetylation of S6 kinase and mimicked the effects of high glucose, resulting in mesangial cell hypertrophy and expression of fibronectin and collagen I (α2). In contrast, siRNA against HDAC1 inhibited these effects by high glucose. A C-terminal acetylation-mimetic mutant of S6 kinase suppressed high glucose-stimulated phosphorylation of S6 kinase, rps6 and eEF2 kinase, and inhibited the dephosphorylation of eEF2. Also, the acetylation mimetic attenuated the mesangial cell hypertrophy and fibronectin and collagen I (α2) expression. Conversely, an S6 kinase acetylation-deficient mutant induced all the above effects of high glucose. Finally, in the renal glomeruli of diabetic rats, the acetylation of S6 kinase was significantly reduced concomitant with increased HDAC1 and S6 kinase activity. In aggregate, our data uncovered a previously unrecognized role of S6 kinase deacetylation in high glucose-induced mesangial cell hypertrophy and matrix protein expression.
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Affiliation(s)
| | | | | | | | - Goutam Ghosh Choudhury
- Departments of Medicine and .,Departments of Medicine and.,Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas 78229 and
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Zhang M, Yan Z, Bu L, An C, Wang D, Liu X, Zhang J, Yang W, Deng B, Xie J, Zhang B. Rapeseed protein-derived antioxidant peptide RAP alleviates renal fibrosis through MAPK/NF-κB signaling pathways in diabetic nephropathy. DRUG DESIGN DEVELOPMENT AND THERAPY 2018; 12:1255-1268. [PMID: 29795979 PMCID: PMC5958891 DOI: 10.2147/dddt.s162288] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Introduction Kidney fibrosis is the main pathologic change in diabetic nephropathy (DN), which is the major cause of end-stage renal disease. Current therapeutic strategies slow down but cannot reverse the progression of renal dysfunction in DN. Plant-derived bioactive peptides in foodstuffs are widely used in many fields because of their potential pharmaceutical and nutraceutical benefits. However, this type of peptide has not yet been studied in renal fibrosis of DN. Previous studies have indicated that the peptide YWDHNNPQIR (named RAP), a natural peptide derived from rapeseed protein, has an antioxidative stress effect. The oxidative stress is believed to be associated with DN. The aim of this study was to evaluate the pharmacologic effects of RAP against renal fibrosis of DN and high glucose (HG)-induced mesangial dysfunction. Materials and methods Diabetes was induced by streptozotocin and high-fat diet in C57BL/6 mice and these mice were treated by subcutaneous injection of different doses of RAP (0.1 mg/kg and 0.5 mg/kg, every other day) or PBS for 12 weeks. Later, functional and histopathologic analyses were performed. Parallel experiments verifying the molecular mechanism by which RAP alleviates DN were carried out in HG-induced mesangial cells (MCs). Results RAP improved the renal function indices, including 24-h albuminuria, triglyceride, serum creatinine, and blood urea nitrogen levels, but did not lower blood glucose levels in DN mice. RAP also simultaneously attenuated extracellular matrix accumulation in DN mice and HG-induced MCs. Furthermore, RAP reduced HG-induced cell proliferation, but it showed no toxicity in MCs. Additionally, RAP inhibited the mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) signaling pathways. Conclusion RAP can attenuate fibrosis in vivo and in vitro by antagonizing the MAPK and NF-κB pathways.
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Affiliation(s)
- Mingyan Zhang
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Zhibin Yan
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Lili Bu
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Chunmei An
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Dan Wang
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Xin Liu
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Jianfeng Zhang
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Wenle Yang
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Bochuan Deng
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Junqiu Xie
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
| | - Bangzhi Zhang
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, Lanzhou, China.,Key Laboratory of Preclinical Study for New Drugs of Gansu Province, School of Basic Medical Sciences, Lanzhou University, Lanzhou, China
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Bera A, Das F, Ghosh-Choudhury N, Mariappan MM, Kasinath BS, Ghosh Choudhury G. Reciprocal regulation of miR-214 and PTEN by high glucose regulates renal glomerular mesangial and proximal tubular epithelial cell hypertrophy and matrix expansion. Am J Physiol Cell Physiol 2017; 313:C430-C447. [PMID: 28701356 PMCID: PMC5668576 DOI: 10.1152/ajpcell.00081.2017] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/06/2017] [Accepted: 07/09/2017] [Indexed: 02/06/2023]
Abstract
Aberrant expression of microRNAs (miRs) contributes to diabetic renal complications, including renal hypertrophy and matrix protein accumulation. Reduced expression of phosphatase and tensin homolog (PTEN) by hyperglycemia contributes to these processes. We considered involvement of miR in the downregulation of PTEN. In the renal cortex of type 1 diabetic mice, we detected increased expression of miR-214 in association with decreased levels of PTEN and enhanced Akt phosphorylation and fibronectin expression. Mesangial and proximal tubular epithelial cells exposed to high glucose showed augmented expression of miR-214. Mutagenesis studies using 3'-UTR of PTEN in a reporter construct revealed PTEN as a direct target of miR-214, which controls its expression in both of these cells. Overexpression of miR-214 decreased the levels of PTEN and increased Akt activity similar to high glucose and lead to phosphorylation of its substrates glycogen synthase kinase-3β, PRAS40, and tuberin. In contrast, quenching of miR-214 inhibited high-glucose-induced Akt activation and its substrate phosphorylation; these changes were reversed by small interfering RNAs against PTEN. Importantly, respective expression of miR-214 or anti-miR-214 increased or decreased the mammalian target of rapamycin complex 1 (mTORC1) activity induced by high glucose. Furthermore, mTORC1 activity was controlled by miR-214-targeted PTEN via Akt activation. In addition, neutralization of high-glucose-stimulated miR-214 expression significantly inhibited cell hypertrophy and expression of the matrix protein fibronectin. Finally, the anti-miR-214-induced inhibition of these processes was reversed by the expression of constitutively active Akt kinase and hyperactive mTORC1. These results uncover a significant role of miR-214 in the activation of mTORC1 that contributes to high-glucose-induced mesangial and proximal tubular cell hypertrophy and fibronectin expression.
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Affiliation(s)
- Amit Bera
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
| | - Falguni Das
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
| | - Nandini Ghosh-Choudhury
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
- Department of Pathology, UT Health San Antonio, San Antonio, Texas; and
| | | | - Balakuntalam S Kasinath
- Department of Medicine, UT Health San Antonio, San Antonio, Texas
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
| | - Goutam Ghosh Choudhury
- Department of Medicine, UT Health San Antonio, San Antonio, Texas;
- Veterans Affairs Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, Texas
- Geriatric Research, Education and Clinical Research, South Texas Veterans Health Care System, San Antonio, Texas
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10
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Das F, Ghosh-Choudhury N, Kasinath BS, Choudhury GG. Tyrosines-740/751 of PDGFRβ contribute to the activation of Akt/Hif1α/TGFβ nexus to drive high glucose-induced glomerular mesangial cell hypertrophy. Cell Signal 2017; 42:44-53. [PMID: 28951244 DOI: 10.1016/j.cellsig.2017.09.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 09/22/2017] [Indexed: 01/24/2023]
Abstract
Glomerular mesangial cell hypertrophy contributes to the complications of diabetic nephropathy. The mechanism by which high glucose induces mesangial cell hypertrophy is poorly understood. Here we explored the role of the platelet-derived growth factor receptor-β (PDGFRβ) tyrosine kinase in driving the high glucose-induced mesangial cell hypertrophy. We show that high glucose stimulates the association of the PDGFRβ with PI 3 kinase leading to tyrosine phosphorylation of the latter. High glucose-induced Akt kinase activation was also dependent upon PDGFRβ and its tyrosine phosphorylation at 740/751 residues. Inhibition of PDGFRβ activity, its downregulation and expression of its phospho-deficient (Y740/751F) mutant inhibited mesangial cell hypertrophy by high glucose. Interestingly, expression of constitutively active Akt reversed this inhibition, indicating a role of Akt kinase downstream of PDGFRβ phosphorylation in this process. The transcription factor Hif1α is a target of Akt kinase. siRNAs against Hif1α inhibited the high glucose-induced mesangial cell hypertrophy. In contrast, increased expression of Hif1α induced hypertrophy similar to high glucose. We found that inhibition of PDGFRβ and expression of PDGFRβ Y740/751F mutant significantly inhibited the high glucose-induced expression of Hif1α. Importantly, expression of Hif1α countered the inhibition of mesangial cell hypertrophy induced by siPDGFRβ or PDGFRβ Y740/751F mutant. Finally, we show that high glucose-stimulated PDGFRβ tyrosine phosphorylation at 740/751 residues and the tyrosine kinase activity of the receptor regulate the transforming growth factor-β (TGFβ) expression by Hif1α. Thus we define the cell surface PDGFRβ as a major link between high glucose and its effectors Hif1α and TGFβ for induction of diabetic mesangial cell hypertrophy.
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Affiliation(s)
- Falguni Das
- Department of Medicine, UT Health at San Antonio, TX, United States
| | - Nandini Ghosh-Choudhury
- VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Department of Pathology, UT Health at San Antonio, TX, United States
| | - Balakuntalam S Kasinath
- Department of Medicine, UT Health at San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States
| | - Goutam Ghosh Choudhury
- Department of Medicine, UT Health at San Antonio, TX, United States; VA Biomedical Laboratory Research, South Texas Veterans Health Care System, San Antonio, TX, United States; Geriatric Research, Education and Clinical Research, South Texas Veterans Health Care System, San Antonio, TX, United States.
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12
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Cross talk between miR-214 and PTEN attenuates glomerular hypertrophy under diabetic conditions. Sci Rep 2016; 6:31506. [PMID: 27549568 PMCID: PMC4994004 DOI: 10.1038/srep31506] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 07/21/2016] [Indexed: 01/25/2023] Open
Abstract
Glomerular mesangial cells (MCs) hypertrophy is one of the earliest pathological abnormalities in diabetic nephropathy (DN), which correlates with eventual glomerulosclerosis. This study aimed to investigate the therapeutic role of miRNA in diabetic glomerular MCs hypertrophy and synthesis of extracellular matrix (ECM). Microarray analysis revealed a significant up-regulation of miR-214 in the renal cortex of diabetic db/db mice, which was confirmed by real-time PCR of isolated glomeruli and primary cultured human MCs. In vitro studies showed that inhibition of miR-214 significantly reduced expression of α-SMA, SM22 and collagen IV, and partially restored phosphatase and tensin homolog (PTEN) protein level in high glucose-stimulated human MCs. Furthermore, we identified PTEN as the target of miR-214 by a luciferase assay in HEK293 cells. Moreover, overexpression of PTEN ameliorated miR-214-mediated diabetic MC hypertrophy while knockdown of PTEN mimicked the MC hypertrophy. In vivo study further confirmed that inhibition of miR-214 significantly decreased the expression of SM22, α-SMA and collagen IV, partially restored PTEN level, and attenuated albuminuria and mesangial expansion in db/db mice. In conclusion, cross talk between miR-214 and PTEN attenuated glomerular hypertrophy under diabetic conditions in vivo and in vitro. Therefore, miR-214 may represent a novel therapeutic target for DN.
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Das F, Ghosh-Choudhury N, Mariappan MM, Kasinath BS, Choudhury GG. Hydrophobic motif site-phosphorylated protein kinase CβII between mTORC2 and Akt regulates high glucose-induced mesangial cell hypertrophy. Am J Physiol Cell Physiol 2016; 310:C583-96. [PMID: 26739493 DOI: 10.1152/ajpcell.00266.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 01/06/2016] [Indexed: 01/23/2023]
Abstract
PKCβII controls the pathologic features of diabetic nephropathy, including glomerular mesangial cell hypertrophy. PKCβII contains the COOH-terminal hydrophobic motif site Ser-660. Whether this hydrophobic motif phosphorylation contributes to high glucose-induced mesangial cell hypertrophy has not been determined. Here we show that, in mesangial cells, high glucose increased phosphorylation of PKCβII at Ser-660 in a phosphatidylinositol 3-kinase (PI3-kinase)-dependent manner. Using siRNAs to downregulate PKCβII, dominant negative PKCβII, and PKCβII hydrophobic motif phosphorylation-deficient mutant, we found that PKCβII regulates activation of mechanistic target of rapamycin complex 1 (mTORC1) and mesangial cell hypertrophy by high glucose. PKCβII via its phosphorylation at Ser-660 regulated phosphorylation of Akt at both catalytic loop and hydrophobic motif sites, resulting in phosphorylation and inactivation of its substrate PRAS40. Specific inhibition of mTORC2 increased mTORC1 activity and induced mesangial cell hypertrophy. In contrast, inhibition of mTORC2 decreased the phosphorylation of PKCβII and Akt, leading to inhibition of PRAS40 phosphorylation and mTORC1 activity and prevented mesangial cell hypertrophy in response to high glucose; expression of constitutively active Akt or mTORC1 restored mesangial cell hypertrophy. Moreover, constitutively active PKCβII reversed the inhibition of high glucose-stimulated Akt phosphorylation and mesangial cell hypertrophy induced by suppression of mTORC2. Finally, using renal cortexes from type 1 diabetic mice, we found that increased phosphorylation of PKCβII at Ser-660 was associated with enhanced Akt phosphorylation and mTORC1 activation. Collectively, our findings identify a signaling route connecting PI3-kinase to mTORC2 to phosphorylate PKCβII at the hydrophobic motif site necessary for Akt phosphorylation and mTORC1 activation, leading to mesangial cell hypertrophy.
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Affiliation(s)
- Falguni Das
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Nandini Ghosh-Choudhury
- Veterans Affairs Research, South Texas Veterans Health Care System, San Antonio, Texas; Departments of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Meenalakshmi M Mariappan
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Balakuntalam S Kasinath
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas; Veterans Affairs Research, South Texas Veterans Health Care System, San Antonio, Texas
| | - Goutam Ghosh Choudhury
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas; Veterans Affairs Research, South Texas Veterans Health Care System, San Antonio, Texas; Geriatric Research, Education and Clinical Research, South Texas Veterans Health Care System, San Antonio, Texas; and
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Branched-chain amino acids attenuate early kidney injury in diabetic rats. Biochem Biophys Res Commun 2015; 466:240-6. [PMID: 26362188 DOI: 10.1016/j.bbrc.2015.09.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 09/04/2015] [Indexed: 12/13/2022]
Abstract
Diabetic nephropathy (DN) is the most severe diabetic microvascular complication. The pathogenesis of diabetic nephropathy is complex, and oxidative stress plays an important role in the development of diabetic nephropathy. Elevated reactive oxygen species (ROS) levels activate various signaling pathways and influence the activities of transforming growth factor-β (TGF-β) and matrix metalloproteinase-9 (MMP-9), which contributes to glomerular hypertrophy. Branched-chain amino acids (BCAAs) are widely used in clinical treatment, and BCAAs can reduce the oxidative stress associated with the diabetic pancreas and some liver diseases. Thus, the aim of the present study was to determine whether BCAAs could attenuate oxidative stress in the kidneys of streptozotocin (STZ)-induced diabetic rats to prevent early diabetic kidney injury. Male Wistar rats were fed for two weeks with a normal chow diet or a high-fat diet in which 40% of calories were derived from fat. After this two-week period, the mice fed normal chow were injected with vehicle, while the high-fat diet group was injected intraperitoneally (i.p.) with 40 mg/kg STZ. The STZ-treated group was randomly divided into four subgroups that were treated with different doses of BCAAs or vehicle for two months by oral gavage. Plasma glucose, plasma creatinine, urinary protein and JNK, TGF-β, and MMP-9 mRNA and protein expression levels were measured in the rats. The ROS levels and proteinuria in the STZ-induced diabetic rats were significantly higher than those in the control groups. Moreover, early kidney injury occurred in the STZ-induced diabetic rats. However, BCAAs treatment decreased ROS levels, proteinuria and kidney injury. Moreover, JNK, TGF-β and MMP-9 mRNA and protein levels were significantly increased in the diabetic rats when compared with the control rats, and BCAAs treatment reversed these changes. Our results suggest that BCAAs counter oxidative stress in the kidneys of diabetic rats and alleviate diabetic kidney injury via the JNK/TGF-β/MMP-9 pathway.
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Romero-Nava R, Rodriguez JE, Reséndiz-Albor AA, Sánchez-Muñoz F, Ruiz-Hernandéz A, Huang F, Hong E, Villafaña S. Changes in protein and gene expression of angiotensin II receptors (AT1 and AT2) in aorta of diabetic and hypertensive rats. Clin Exp Hypertens 2015; 38:56-62. [PMID: 26268856 DOI: 10.3109/10641963.2015.1060984] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Diabetes and hypertension have been associated with cardiovascular diseases and stroke. Some reports have related the coexistence of hypertension and diabetes with increase in the risk of developing vascular complications. Recently some studies have shown results suggesting that in the early stages of diabetes and hypertension exist a reduced functional response to vasopressor agents like angiotensin II (Ang II), which plays an important role in blood pressure regulation mechanism through the activation of its AT1 and AT2 receptors. For that reason, the aim of this work was to study the gene and protein expression of AT1 and AT2 receptors in aorta of diabetic SHR and WKY rats. Diabetes was induced by the administration of streptozotocin (60 mg/kg i.p.). After 4 weeks of the onset of diabetes, the protein expression was obtained by western blot and the mRNA expression by RT-PCR. Our results showed that the hypertensive rats have a higher mRNA and protein expression of AT1 receptors than normotensive rats while the AT2 expression remained unchanged. On the other hand, the combination of diabetes and hypertension increased the mRNA and protein expression of AT1 and AT2 receptors significantly. In conclusion, our results suggest that diabetes with hypertension modifies the mRNA and protein expression of AT1 and AT2 receptors. However, the overexpression of AT2 could be associated with the reduction in the response to Ang II in the early stage of diabetes.
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Affiliation(s)
- R Romero-Nava
- a Laboratorio de Señalización Intracelular , Sección de Posgrado, Escuela Superior de Medicina del Instituto Politécnico Nacional, México D.F. , México
| | - J E Rodriguez
- a Laboratorio de Señalización Intracelular , Sección de Posgrado, Escuela Superior de Medicina del Instituto Politécnico Nacional, México D.F. , México
| | - A A Reséndiz-Albor
- a Laboratorio de Señalización Intracelular , Sección de Posgrado, Escuela Superior de Medicina del Instituto Politécnico Nacional, México D.F. , México
| | - F Sánchez-Muñoz
- b Departamento de Inmunología , Instituto Nacional de Cardiología Ignacio Chávez, México D.F. , México
| | - A Ruiz-Hernandéz
- a Laboratorio de Señalización Intracelular , Sección de Posgrado, Escuela Superior de Medicina del Instituto Politécnico Nacional, México D.F. , México
| | - F Huang
- c Departamento de Farmacología y Toxicología , Hospital Infantil de México Federico Gómez (HIMFG), México D.F. , México , and
| | - E Hong
- d Departamento de Neurofarmacobiología , Centro de Investigación y de Estudios Avanzados, México D.F. , México
| | - S Villafaña
- a Laboratorio de Señalización Intracelular , Sección de Posgrado, Escuela Superior de Medicina del Instituto Politécnico Nacional, México D.F. , México
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Wang X, Shen E, Wang Y, Jiang Z, Gui D, Cheng D, Chen T, Wang N. MiR-196a Regulates High Glucose-Induced Mesangial Cell Hypertrophy by Targeting p27kip1. ACTA ACUST UNITED AC 2015; 20:491-9. [PMID: 25657172 DOI: 10.1177/2211068215569055] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Indexed: 11/17/2022]
Abstract
Glomerular mesangial cell (MC) hypertrophy is regarded as one of the earliest pathological characteristics of diabetic nephropathy (DN), which plays a critical role in the pathogenesis of glomerulosclerosis. This study investigated the role of microRNAs (miRNAs) in MC hypertrophy due to exposure to high glucose. With a microarray, we screened the differential profiles of miRNAs in the renal cortex of DN mice, as verified by reverse transcription PCR with subsequent analysis of bioinformatics. We found miR-196a was downregulated remarkably in DN mice and increased the hypertrophy-related gene of p27(kip1) in high-enrichment gene ontologies. Furthermore, transfection of the miR-196a mimic greatly inhibited the expression of p27(kip1) with recovery of MC hypertrophic morphology. With flow cytometry, we also found that overexpression of miR-196a significantly reduced the percentage of G1 phase arrest in the cell cycle. Cotransfection of the miR-196a mimic with a wild type of 3' UTR of the p27(kip1) vector reduced the activity of the luciferase reporter significantly in contrast to the miR-196a mimic with a mutant of the counterpart in HEK293 cell lines, suggesting that miR-196a directly targets p27(kip1). Finally, knockdown of p27(kip1) with specific small interfering RNA in MCs substantially reversed MC hypertrophy induced by transfection of the miR-196a inhibitor. This study revealed that miR-196a acts as an important molecular regulator in high glucose-induced MC hypertrophy by targeting p27(kip1).
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Affiliation(s)
- Xiaoxia Wang
- Department of Nephrology, Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P. R. China
| | - E Shen
- Department of Ultrasound in Medicine, Tong Ren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P. R. China
| | - Yanzhe Wang
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, P. R. China
| | - Zhenzhen Jiang
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, P. R. China
| | - Dingkun Gui
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, P. R. China
| | - Dongsheng Cheng
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, P. R. China
| | - Tingfang Chen
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, P. R. China
| | - Niansong Wang
- Department of Nephrology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, P. R. China
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Das F, Ghosh-Choudhury N, Dey N, Bera A, Mariappan MM, Kasinath BS, Ghosh Choudhury G. High glucose forces a positive feedback loop connecting Akt kinase and FoxO1 transcription factor to activate mTORC1 kinase for mesangial cell hypertrophy and matrix protein expression. J Biol Chem 2014; 289:32703-16. [PMID: 25288788 DOI: 10.1074/jbc.m114.605196] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
High glucose-induced Akt acts as a signaling hub for mesangial cell hypertrophy and matrix expansion, which are recognized as cardinal signatures for the development of diabetic nephropathy. How mesangial cells sustain the activated state of Akt is not clearly understood. Here we show Akt-dependent phosphorylation of the transcription factor FoxO1 by high glucose. Phosphorylation-deficient, constitutively active FoxO1 inhibited the high glucose-induced phosphorylation of Akt to suppress the phosphorylation/inactivation of PRAS40 and mTORC1 activity. In contrast, dominant negative FoxO1 increased the phosphorylation of Akt, resulting in increased mTORC1 activity similar to high glucose treatment. Notably, FoxO1 regulates high glucose-induced protein synthesis, hypertrophy, and expression of fibronectin and PAI-1. High glucose paves the way for complications of diabetic nephropathy through the production of reactive oxygen species (ROS). We considered whether the FoxO1 target antioxidant enzyme catalase contributes to sustained activation of Akt. High glucose-inactivated FoxO1 decreases the expression of catalase to increase the production of ROS. Moreover, we show that catalase blocks high glucose-stimulated Akt phosphorylation to attenuate the inactivation of FoxO1 and PRAS40, resulting in the inhibition of mTORC1 and mesangial cell hypertrophy and fibronectin and PAI-1 expression. Finally, using kidney cortices from type 1 diabetic OVE26 mice, we show that increased FoxO1 phosphorylation is associated with decreased catalase expression and increased fibronectin and PAI-1 expression. Together, our results provide the first evidence for the presence of a positive feedback loop for the sustained activation of Akt involving inactivated FoxO1 and a decrease in catalase expression, leading to increased ROS and mesangial cell hypertrophy and matrix protein expression.
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Affiliation(s)
| | - Nandini Ghosh-Choudhury
- Pathology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229 From the Veterans Affairs Research and Geriatric Research and
| | | | | | | | - Balakuntalam S Kasinath
- the Departments of Medicine and From the Veterans Affairs Research and Geriatric Research and
| | - Goutam Ghosh Choudhury
- the Departments of Medicine and From the Veterans Affairs Research and Geriatric Research and Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas 78229 and
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Arrellano-Valdez F, Urrutia-Osorio M, Arroyo C, Soto-Vega E. A comprehensive review of urologic complications in patients with diabetes. SPRINGERPLUS 2014; 3:549. [PMID: 25332855 PMCID: PMC4183758 DOI: 10.1186/2193-1801-3-549] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Accepted: 09/10/2014] [Indexed: 12/15/2022]
Abstract
Diabetes Mellitus (DM) is a chronic disease characterized by hyperglycemia, as a result of abnormal insulin production, insulin function, or both. DM is associated with systemic complications, such as infections, neuropathy and angiopathy, which involve the genitourinary tract. The three most significant urologic complications include: bladder cystopathy, sexual dysfunction and urinary tract infections. Almost half of the patients with DM have bladder dysfunction or cystopathy, which can be manifested in women as hypersensitivity (in 39-61% of the diabetic women) or neurogenic bladder. In males it can be experienced as lower urinary tract symptoms (in 25% of diabetic males with a nearly twofold increased risk when seen by age groups). Additionally, an increased prostate volume affects their micturition as well as their urinary tract. Involving sexual dysfunction in women, it includes reduced libido, decreased arousal, clitoral erectile dysfunction and painful or non-sensitive intercourse; and in diabetic males it varies from low libido, ejaculatory abnormalities and erectile dysfunction. Globally, sexual disorders have a prevalence of 18-42%. Erectile dysfunction is ranked as the third most important complication of DM. Urinary tract infections are observed frequently in diabetic patients, and vary from emphysematous infections, Fournier gangrene, staghorn infected lithiasis to repetitive bacterial cystitis. The most frequent finding in diabetic women has been lower urinary tract infections. Because of the high incidence of obesity worldwide and its association with diabetes, it is very important to keep in mind the urologic complication associated with DM in patients, in order to better diagnose and treat this population.
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Affiliation(s)
- Fernando Arrellano-Valdez
- />Facultad de Medicina, Universidad Popular Autónoma del Estado de Puebla, 21 sur 1103, Barrio de Santiago, Puebla, Puebla C.P 72410 México
| | - Marta Urrutia-Osorio
- />Facultad de Medicina, Universidad Popular Autónoma del Estado de Puebla, 21 sur 1103, Barrio de Santiago, Puebla, Puebla C.P 72410 México
| | - Carlos Arroyo
- />Hospital Ángeles de Puebla, Puebla, México
- />Hospital Universitario de Puebla, Benemérita Universidad Autónoma de Puebla, Avenida 25 Poniente 1301, Los Volcanes, 72410 Heroica Puebla De Zaragoza, PUE Mexico
| | - Elena Soto-Vega
- />Facultad de Medicina, Universidad Popular Autónoma del Estado de Puebla, 21 sur 1103, Barrio de Santiago, Puebla, Puebla C.P 72410 México
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Gorin Y, Block K. Nox4 and diabetic nephropathy: with a friend like this, who needs enemies? Free Radic Biol Med 2013; 61:130-42. [PMID: 23528476 PMCID: PMC3716866 DOI: 10.1016/j.freeradbiomed.2013.03.014] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 03/12/2013] [Accepted: 03/16/2013] [Indexed: 12/19/2022]
Abstract
Oxidative stress has been linked to the pathogenesis of diabetic nephropathy, a complication of diabetes in the kidney. NADPH oxidases of the Nox family are a major source of reactive oxygen species in the diabetic kidney and are critical mediators of redox signaling in glomerular and tubulointerstitial cells exposed to the diabetic milieu. Here, we present an overview of the current understanding of the roles of Nox catalytic and regulatory subunits in the processes that control mesangial cell, podocyte, and tubulointerstitial cell injury induced by hyperglycemia and other predominant factors enhanced in the diabetic milieu, including the renin-angiotensin system and transforming growth factor-β. The role of the Nox isoform Nox4 in the redox processes that alter renal biology in diabetes is highlighted.
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Affiliation(s)
- Yves Gorin
- Department of Medicine, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
| | - Karen Block
- Department of Medicine, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA; Audie L. Murphy Memorial Hospital Division, South Texas Veterans Health Care System, San Antonio, TX 78229, USA.
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Abstract
Oxidative stress has been linked to the pathogenesis of the major complications of diabetes in the kidney, the heart, the eye or the vasculature. NADPH oxidases of the Nox family are a major source of ROS (reactive oxygen species) and are critical mediators of redox signalling in cells from different organs afflicted by the diabetic milieu. In the present review, we provide an overview of the current knowledge related to the understanding of the role of Nox in the processes that control cell injury induced by hyperglycaemia and other predominant factors enhanced in diabetes, including the renin–angiotensin system, TGF-β (transforming growth factor-β) and AGEs (advanced glycation end-products). These observations support a critical role for Nox homologues in diabetic complications and indicate that NADPH oxidases are an important therapeutic target. Therefore the design and development of small-molecule inhibitors that selectively block Nox oxidases appears to be a reasonable approach to prevent or retard the complications of diabetes in target organs. The bioefficacy of these agents in experimental animal models is also discussed in the present review.
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Nagaoka T, Yoshida A. Relationship between retinal blood flow and renal function in patients with type 2 diabetes and chronic kidney disease. Diabetes Care 2013; 36. [PMID: 23204249 PMCID: PMC3609484 DOI: 10.2337/dc12-0864] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To study the relationship between retinal microcirculation and renal function in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS Using a laser Doppler velocimetry system, we obtained the retinal blood flow (RBF) values by simultaneously measuring the retinal vessel diameter and blood velocity. To determine if the RBF is affected in the presence of renal dysfunction, we also evaluated the renal function using the estimated glomerular filtration rate calculated by age and serum creatinine level. RESULTS We recruited 169 eyes of 169 consecutive Japanese patients with type 2 diabetes, no or minimal diabetic retinopathy, and normo/microalbuminuria (mean age ± SD, 59.0 ± 11.1 years). We divided the patients into four groups based on the stage of chronic kidney disease (CKD) (non-CKD, n = 99; CKD stage 1, n = 22; stage 2, n = 27; stage 3, n = 21). We found significant (P = 0.035) decreases in RBF with decreased vessel diameter (P = 0.017) but no difference in blood velocity (P = 0.54) in stage 3 CKD compared with the non-CKD group. Multiple regression analysis showed that the CKD stage was significantly (P = 0.02) and independently associated with decreased RBF. CONCLUSIONS Our results indicated that the vessel diameter and RBF in the retinal arterioles decrease in patients with type 2 diabetes with stage 3 CKD, suggesting that impaired renal function might be associated with decreased RBF, probably via constriction of the retinal arterioles, in early-phase diabetic retinopathy.
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Affiliation(s)
- Taiji Nagaoka
- Department of Ophthalmology, Asahikawa Medical University, Asahikawa, Japan.
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22
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Palatini P. Glomerular hyperfiltration: a marker of early renal damage in pre-diabetes and pre-hypertension. Nephrol Dial Transplant 2012; 27:1708-14. [DOI: 10.1093/ndt/gfs037] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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23
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Hsieh PF, Liu SF, Lee TC, Huang JS, Yin LT, Chang WT, Chuang LY, Guh JY, Hung MY, Yang YL. The role of IL-7 in renal proximal tubule epithelial cells fibrosis. Mol Immunol 2012; 50:74-82. [PMID: 22261356 DOI: 10.1016/j.molimm.2011.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 12/08/2011] [Accepted: 12/12/2011] [Indexed: 02/02/2023]
Abstract
BACKGROUND Hyperglycemia is the most important risk factor in the progression of renal fibrosis in diabetic kidney. Based on previous studies, interleukin-7 (IL-7) may exert antifibrotic activities in pulmonary fibrosis model. However, the role of IL-7 in the pathogenesis of renal tubulointerstitial fibrosis remains unclear. Thus, we hereby elucidate the effects of IL-7 in cultured renal proximal tubular epithelial cells (designated as HK-2) treated under hyperglycemic condition. METHODS Cells were cultured in high glucose (27.5mM) for 2 days. Different concentration of IL-7 (10, 50, 100 or 200ng/ml) was added in the last 24h of culture. ELISA was used to evaluate the secreted protein such as fibronectin and TGF-β(1). Western blot was used to examine the EMT marker (including α-smooth muscle actin (α-SMA) and E-cadherin), signal transducer (including Smad Smad2/3 and Smad7) and EMT initiator (e.g. Snail). Immunofluorescence staining was used to assay the in situ expression of proteins (e.g. fibronectin and Snail). RESULTS We found that IL-7 significantly attenuated high glucose-inhibited cellular growth and high glucose-induced fibrosis. More importantly, high glucose-induced up-regulation of fibronectin, TGF-β, TGF-β RII and pSmad2/3 was markedly inhibited by IL-7. On the contrary, high glucose-induced down-regulation of Smad7 was significantly reversed by IL-7 instead. IL-7 markedly inhibited high glucose-induced increase in α-SMA and Snail and decrease in E-cadherin. CONCLUSION We demonstrate that IL-7 has the potential to inhibit high glucose-induced renal proximal tubular fibrosis partly by modulating Smads and EMT pathway.
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Affiliation(s)
- Pei-Fang Hsieh
- Graduate Institute of Biomedical Science, Chung Hwa University of Medical Technology, Tainan, Taiwan
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Romaker D, Zhang B, Wessely O. An immunofluorescence method to analyze the proliferation status of individual nephron segments in the Xenopus pronephric kidney. Methods Mol Biol 2012; 886:121-132. [PMID: 22639256 PMCID: PMC3425951 DOI: 10.1007/978-1-61779-851-1_11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Organ development requires the coordination of proliferation and differentiation of various cell types. This is particularly challenging in the kidney, where up to 26 different cell types with highly specialized functions are present. Moreover, even though the nephron initially develops from a common progenitor pool, the individual nephron segments are ultimately quite different in respect to cell numbers. This suggests that some cells in the nephron have a higher proliferative index (i.e., cell cycle length) than others. Here, we describe two different immunofluorescence-based approaches to accurately quantify such growth rates in the pronephric kidney of Xenopus laevis. Rapidly dividing cells were identified with the mitosis marker phospho-Histone H3, while slowly cycling cells were labeled using the thymidine analogue EdU. In addition, individual nephron segments were marked using cell type-specific antibodies. To accurately assess the number of positively stained cells, embryos were then serially sectioned and analyzed by immunofluorescence microscopy. Growth rates were established by counting the mitosis or S-phase events in relation to the overall cells present in the nephron segment of interest. This experimental design is very reproducible and can easily be modified to fit other animal models and organ systems.
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Affiliation(s)
- Daniel Romaker
- Lerner Research Institute/Cleveland Clinic, Department of Cell Biology, 9500 Euclid Avenue/NC10, Cleveland, OH 44195, USA
| | - Bo Zhang
- Lerner Research Institute/Cleveland Clinic, Department of Cell Biology, 9500 Euclid Avenue/NC10, Cleveland, OH 44195, USA
- LSU Health Sciences Center, Department of Cell Biology & Anatomy, MEB 6A12, 1901 Perdido Street, New Orleans, LA 70112, USA
| | - Oliver Wessely
- Lerner Research Institute/Cleveland Clinic, Department of Cell Biology, 9500 Euclid Avenue/NC10, Cleveland, OH 44195, USA
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Usefulness of Enhanced Power Doppler Imaging in Monitoring Acral Microcirculation in Type 2 Diabetes Mellitus and its Complications. Cell Biochem Biophys 2011; 61:435-41. [DOI: 10.1007/s12013-011-9208-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Golbidi S, Laher I. Bladder dysfunction in diabetes mellitus. Front Pharmacol 2010; 1:136. [PMID: 21833175 PMCID: PMC3153010 DOI: 10.3389/fphar.2010.00136] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 10/29/2010] [Indexed: 12/15/2022] Open
Abstract
Diabetic cystopathy is a well-recognized complication of diabetes mellitus, which usually develops in middle-aged or elderly patients with long-standing and poorly controlled disease. It may have broad spectrum clinical presentations. Patients may be asymptomatic, or have a wide variety of voiding complaints from overactive bladder and urge incontinence to decreased bladder sensation and overflow incontinence. This review focuses on pathophysiological mechanisms responsible for urologic complications of diabetes and emphasizing on recent developments in our understanding of this condition. We also tried to shed some light on therapeutic modalities like behavioral, pharmacological, and surgical approaches.
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Affiliation(s)
- Saeid Golbidi
- Department of Pharmacology and Therapeutics, Faculty of Medicine, University of British Columbia Vancouver, BC, Canada
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Dey N, Ghosh-Choudhury N, Das F, Li X, Venkatesan B, Barnes JL, Kasinath BS, Ghosh Choudhury G. PRAS40 acts as a nodal regulator of high glucose-induced TORC1 activation in glomerular mesangial cell hypertrophy. J Cell Physiol 2010; 225:27-41. [PMID: 20629086 DOI: 10.1002/jcp.22186] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Diabetic nephropathy manifests aberrant activation of TORC1, which senses key signals to modulate protein synthesis and renal hypertrophy. PRAS40 has recently been identified as a raptor-interacting protein and is a component and a constitutive inhibitor of TORC1. The mechanism by which high glucose stimulates TORC1 activity is not known. PRAS40 was identified in the mesangial cells in renal glomeruli and in tubulointerstitium of rat kidney. Streptozotocin-induced diabetic renal hypertrophy was associated with phosphorylation of PRAS40 in the cortex and glomeruli. In vitro, high glucose concentration increased PRAS40 phosphorylation in a PI 3 kinase- and Akt-dependent manner, resulting in dissociation of raptor-PRAS40 complex in mesangial cells. High glucose augmented the inactivating and activating phosphorylation of 4EBP-1 and S6 kinase, respectively, with concomitant induction of protein synthesis and hypertrophy. Expression of TORC1-nonphosphorylatable mutant of 4EBP-1 and dominant-negative S6 kinase significantly inhibited high glucose-induced protein synthesis and hypertrophy. PRAS40 knockdown mimicked the effect of high glucose on phosphorylation of 4EBP-1 and S6 kinase, protein synthesis, and hypertrophy. To elucidate the role of PRAS40 phosphorylation, we used phosphorylation-deficient mutant of PRAS40, which in contrast to PRAS40 knockdown inhibited phosphorylation of 4EBP-1 and S6 kinase, leading to reduced mesangial cell hypertrophy. Thus, our data identify high glucose-induced phosphorylation and inactivation of PRAS40 as a central node for mesangial cell hypertrophy in diabetic nephropathy.
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Affiliation(s)
- Nirmalya Dey
- Department of Medicine, University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA
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28
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Lu YC, Yin LT, Chang WT, Huang JS. Effect of Lactobacillus reuteri GMNL-263 treatment on renal fibrosis in diabetic rats. J Biosci Bioeng 2010; 110:709-15. [PMID: 20691633 DOI: 10.1016/j.jbiosc.2010.07.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Revised: 07/14/2010] [Accepted: 07/14/2010] [Indexed: 02/08/2023]
Abstract
Hyperglycemia is the most important factor in the progression of renal fibrosis in diabetic kidney. Prevention and treatment of renal fibrosis may improve diabetic nephropathy. To explore whether probiotic Lactobacillus reuteri GMNL-263 treatment was linked to altered hyperglycemia-mediated renal fibrosis in diabetic kidney, the mechanisms of L. reuteri GMNL-263 treatment responsible for the inhibition of renal fibrosis in streptozotocin (STZ)-induced diabetic rats were examined. Diabetic rats were induced by intraperitoneal injection of STZ (50 mg/kg). Induction of diabetes was confirmed by measurement of the blood glucose using the glucose oxidase method, and hyperglycemic rats with levels >16 mmol/L were used. We found that L. reuteri GMNL-263 treatment caused reduction of glycated hemoglobin and blood glucose levels in STZ-induced diabetic rats for 28 days (all p<0.05). Treatment with L. reuteri GMNL-263 increased body weight but decreased kidney weight in diabetic rats as compared to diabetic control (p<0.05). In diabetic renal cortex, the Janus kinase 2/signal transducers and activators of transcription 1 (but not extracellular signal-regulated kinase/c-Jun N-terminal kinase/p38 mitogen-activated protein kinase) activation was markedly blocked by L. reuteri GMNL-263 treatment. The ability of L. reuteri GMNL-263 treatment to inhibit renal fibrosis was verified by the observation that it significantly decreased protein levels of plasminogen activator inhibitor-1, p21(Waf1/Cip1), α-smooth muscle actin, and fibronectin in diabetic renal cortex. The results obtained in this study indicate that L. reuteri GMNL-263 treatment may protect STZ-induced diabetic rats from hyperglycemia-enhanced renal fibrosis.
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Affiliation(s)
- Ying-Chen Lu
- Department of Biological Science and Technology, Chung Hwa University of Medical Technology, Tainan 717, Taiwan, ROC
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29
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Satriano J, Mansoury H, Deng A, Sharma K, Vallon V, Blantz RC, Thomson SC. Transition of kidney tubule cells to a senescent phenotype in early experimental diabetes. Am J Physiol Cell Physiol 2010; 299:C374-80. [PMID: 20505038 PMCID: PMC2928628 DOI: 10.1152/ajpcell.00096.2010] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 05/25/2010] [Indexed: 12/31/2022]
Abstract
Diabetic nephropathy is the commonest cause of end-stage renal disease. Inordinate kidney growth and glomerular hyperfiltration at the very early stages of diabetes are putative antecedents to this disease. The kidney is the only organ that grows larger with the onset of diabetes mellitus, yet there remains confusion about the mechanism and significance of this growth. Here we show that kidney proximal tubule cells in culture transition to senescence in response to oxidative stress. We further determine the temporal expression of G(1) phase cell cycle components in rat kidney cortex at days 4 and 10 of streptozotocin diabetes to evaluate changes in this growth response. In diabetic rats we observe increases in kidney weight-to-body weight ratios correlating with increases in expression of the growth-related proteins in the kidney at day 4 after induction of diabetes. However, at day 10 we find a decrease in this profile in diabetic animals coincident with increased cyclin-dependent kinase inhibitor expressions. We observe no change in caspase-3 expression in the diabetic kidneys at these early time points; however, diabetic animals demonstrate reduced kidney connexin 43 and increased plasminogen activator inhibitor-1 expressions and increased senescence-associated beta-galactosidase activity in cortical tubules. In summary, diabetic kidneys exhibit an early temporal induction of growth phase components followed by their suppression concurrent with the induction of cyclin-dependent kinase inhibitors and markers of senescence. These data delineate a phenotypic change in cortical tubules early in the pathogenesis of diabetes that may contribute to further downstream complications of the disease.
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Affiliation(s)
- Joseph Satriano
- Division of Nephrology-Hypertension, University of California San Diego, La Jolla, California, USA.
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High glucose up-regulates angiotensin II subtype 2 receptors via interferon regulatory factor-1 in proximal tubule epithelial cells. Mol Cell Biochem 2010; 344:65-71. [PMID: 20596758 DOI: 10.1007/s11010-010-0529-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2010] [Accepted: 06/22/2010] [Indexed: 10/19/2022]
Abstract
Earlier studies have reported an increase in the proximal tubule AT(2) receptor (AT(2)R) expression in diabetes, with a beneficial role in kidney function and blood pressure regulation. Here, we demonstrate that the increase in AT(2)R protein expression is associated with an increased expression of transcription factor IRF-1 in hyperglycemic rat and in high glucose-treated HK2 cells. Knock-down of IRF-1 by siRNA in HK2 cells prevented high glucose-induced AT(2)R up-regulation. The data suggest that IRF-1 is a transcriptional regulator of AT(2)R expression in hyperglycemia, and warrant further studies to understand the physiological role of IRF-1 along with AT(2)R in diabetic kidney.
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31
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Daneshgari F, Liu G, Birder L, Hanna-Mitchell AT, Chacko S. Diabetic bladder dysfunction: current translational knowledge. J Urol 2010; 182:S18-26. [PMID: 19846137 DOI: 10.1016/j.juro.2009.08.070] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2009] [Indexed: 02/06/2023]
Abstract
PURPOSE Diabetes mellitus, a metabolic disorder caused by an absolute or relative deficiency of insulin, is a debilitating and costly disease with multiple serious complications. Lower urinary tract complications are among the most common complications of diabetes mellitus. The most common, bothersome lower urinary tract complication of diabetes mellitus is diabetic cystopathy or diabetic bladder dysfunction. We reviewed the current translational knowledge of diabetic bladder dysfunction. MATERIALS AND METHODS We performed a search of the English literature through PubMed. The key words used were diabetes and bladder dysfunction or cystopathy. Our data and perspective are provided for consideration of the future direction of research. RESULTS Despite traditional recognition of diabetic bladder dysfunction as a voiding problem characterized by poor emptying and overflow incontinence, recent clinical and experimental evidence indicate storage problems such as urgency and urge incontinence in diabetes mellitus cases. Recent experimental evidence from studies of diabetic bladder dysfunction in small animal models of diabetes mellitus show a temporal effect on diabetic bladder dysfunction. Early phase diabetes mellitus causes compensated bladder function and the late phase causes decompensated bladder function. The temporal theory could plausibly provide the scientific road map to correlate clinical and experimental findings, and identify the role of mechanisms such as polyuria, hyperglycemia, oxidative stress, autonomic neuropathy and decompensation of the bladder contractile apparatus in the creation of clinical and experimental manifestations of diabetic bladder dysfunction. CONCLUSIONS Diabetic bladder dysfunction includes time dependent manifestations of storage and emptying problems. Identifying mechanistic pathways would lead to the identification of therapeutic intervention.
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Affiliation(s)
- Firouz Daneshgari
- Department of Urology, Case Western Reserve University, Cleveland, Ohio, USA.
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32
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Huang JS, Chuang LY, Guh JY, Yang YL, Hsu MS. Effect of taurine on advanced glycation end products-induced hypertrophy in renal tubular epithelial cells. Toxicol Appl Pharmacol 2008; 233:220-6. [DOI: 10.1016/j.taap.2008.09.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 08/29/2008] [Accepted: 09/03/2008] [Indexed: 02/07/2023]
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Kasinath BS, Mariappan MM, Sataranatarajan K, Lee MJ, Ghosh Choudhury G, Feliers D. Novel mechanisms of protein synthesis in diabetic nephropathy--role of mRNA translation. Rev Endocr Metab Disord 2008; 9:255-66. [PMID: 18654857 PMCID: PMC5886780 DOI: 10.1007/s11154-008-9091-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Ambient protein levels are affected by both synthesis and degradation. Synthesis of a protein is regulated by transcription and messenger RNA (mRNA) translation. Translation has emerged as an important site of regulation of protein expression during development and disease. It is under the control of distinct factors that regulate initiation, elongation and termination phases. Regulation of translation occurs via signaling reactions, guanosine diphosphate-guanosine triphosphate binding and by participation of non-coding RNA species such as microRNA. Recent work has revealed an important role for translation in hypertrophy, matrix protein synthesis, elaboration of growth factors in in vivo and in vitro models of diabetic nephropathy. Studies of translation dysregulation in diabetic nephropathy have enabled identification of novel therapeutic targets. Translation of mRNA is a fertile field for exploration in investigation of kidney disease.
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Affiliation(s)
- B S Kasinath
- O'Brien Kidney Research Center, Department of Medicine, University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
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Wu G, Bazer FW, Davis TA, Kim SW, Li P, Marc Rhoads J, Carey Satterfield M, Smith SB, Spencer TE, Yin Y. Arginine metabolism and nutrition in growth, health and disease. Amino Acids 2008; 37:153-68. [PMID: 19030957 DOI: 10.1007/s00726-008-0210-y] [Citation(s) in RCA: 809] [Impact Index Per Article: 50.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2008] [Accepted: 11/05/2008] [Indexed: 12/11/2022]
Abstract
L-Arginine (Arg) is synthesised from glutamine, glutamate, and proline via the intestinal-renal axis in humans and most other mammals (including pigs, sheep and rats). Arg degradation occurs via multiple pathways that are initiated by arginase, nitric-oxide synthase, Arg:glycine amidinotransferase, and Arg decarboxylase. These pathways produce nitric oxide, polyamines, proline, glutamate, creatine, and agmatine with each having enormous biological importance. Arg is also required for the detoxification of ammonia, which is an extremely toxic substance for the central nervous system. There is compelling evidence that Arg regulates interorgan metabolism of energy substrates and the function of multiple organs. The results of both experimental and clinical studies indicate that Arg is a nutritionally essential amino acid (AA) for spermatogenesis, embryonic survival, fetal and neonatal growth, as well as maintenance of vascular tone and hemodynamics. Moreover, a growing body of evidence clearly indicates that dietary supplementation or intravenous administration of Arg is beneficial in improving reproductive, cardiovascular, pulmonary, renal, gastrointestinal, liver and immune functions, as well as facilitating wound healing, enhancing insulin sensitivity, and maintaining tissue integrity. Additionally, Arg or L-citrulline may provide novel and effective therapies for obesity, diabetes, and the metabolic syndrome. The effect of Arg in treating many developmental and health problems is unique among AAs, and offers great promise for improved health and wellbeing of humans and animals.
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Affiliation(s)
- Guoyao Wu
- Department of Animal Science, Texas A&M University, College Station, TX 77843, USA.
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35
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He Q, Kong X, Wu G, Ren P, Tang H, Hao F, Huang R, Li T, Tan B, Li P, Tang Z, Yin Y, Wu Y. Metabolomic analysis of the response of growing pigs to dietary L-arginine supplementation. Amino Acids 2008; 37:199-208. [PMID: 18989615 DOI: 10.1007/s00726-008-0192-9] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Accepted: 10/05/2008] [Indexed: 12/14/2022]
Abstract
Arginine plays an important role regulating nutrient metabolism, but the underlying mechanisms are largely unknown. This study was conducted to determine the effect of dietary arginine supplementation on the metabolome in serum of growing pigs using (1)H nuclear magnetic resonance spectroscopy. Sixteen 120-day-old pigs (48 +/- 1 kg) were randomly assigned to one of two groups, representing supplementation with 0 or 1.0% L: -arginine to corn- and soybean meal-based diets. Serum was collected after a 46-day period of treatment. Dietary arginine supplementation decreased fat deposition and increased protein accretion in the body. Principal component analysis showed that serum concentrations of low density lipoprotein, very low density lipoprotein, and urea were lower, but concentrations of creatinine, tricarboxylic acid cycle metabolites, ornithine, lysine and tyrosine were greater in arginine-supplemented than in control pigs. Additionally, the arginine treatment affected serum concentrations of nitrogenous and lipid signaling molecules (glycerophosphorylcholine and myo-inositol) and intestinal bacterial metabolites (formate, ethanol, methylamine, dimethylamine, acetate, and propionate). These novel findings suggest that dietary arginine supplementation alters the catabolism of fat and amino acids in the whole body, enhances protein synthesis in skeletal muscle, and modulates intestinal microbial metabolism in growing pigs.
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Affiliation(s)
- Qinghua He
- State Key Laboratory of Food Science and Technology, Nanchang University, 330047, Nanchang, Jiangxi, China
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Sen U, Rodriguez WE, Tyagi N, Kumar M, Kundu S, Tyagi SC. Ciglitazone, a PPARgamma agonist, ameliorates diabetic nephropathy in part through homocysteine clearance. Am J Physiol Endocrinol Metab 2008; 295:E1205-12. [PMID: 18780770 PMCID: PMC2584817 DOI: 10.1152/ajpendo.90534.2008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2008] [Accepted: 09/02/2008] [Indexed: 01/11/2023]
Abstract
Diabetes and hyperhomocysteinemia (HHcy) are two independent risk factors for glomeruloslerosis and renal insufficiency. Although PPARgamma agonists such as ciglitazone (CZ) are known to modulate diabetic nephropathy, the role of CZ in diabetes-associated HHcy and renopathy is incompletely defined. We tested the hypothesis that induction of PPARgamma by CZ decreases tissue Hcy level; this provides a protective role against diabetic nephropathy. C57BL/6J mice were administered alloxan to create diabetes. Mice were grouped to 0, 1, 10, 12, and 16 wk of treatment; only 12- and 16-wk animals received CZ in drinking water after a 10-wk alloxan treatment. In diabetes, PPARgamma cDNA, mRNA, and protein expression were repressed, whereas an increase in plasma and glomerular Hcy levels was observed. CZ normalized PPARgamma mRNA and protein expression and glomerular level of Hcy, whereas plasma level of Hcy remained unchanged. GFR was dramatically increased at 1-wk diabetic induction, followed by hypofiltration at 10 wk, and was normalized by CZ treatment. This result corroborated with glomerular and preglomerular arteriole histology. A steady-state increase of RVR in diabetic mice became normal with CZ treatment. CZ ameliorated decrease bioavailability of NO in the diabetic animal. Glomerular MMP-2 and MMP-9 activities as well as TIMP-1 expression were increased robustly in diabetic mice and normalized with CZ treatment. Interestingly, TIMP-4 expression was opposite to that of TIMP-1 in diabetic and CZ-treated groups. These results suggested that diabetic nephropathy exacerbated glomerular tissue level of Hcy, and this caused further deterioration of glomerulus. CZ, however, protected diabetic nephropathy in part by activating PPARgamma and clearing glomerular tissue Hcy.
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Affiliation(s)
- Utpal Sen
- Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky 40202, USA.
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Davenport JR, Watts AJ, Roper VC, Croyle MJ, van Groen T, Wyss JM, Nagy TR, Kesterson RA, Yoder BK. Disruption of intraflagellar transport in adult mice leads to obesity and slow-onset cystic kidney disease. Curr Biol 2007; 17:1586-94. [PMID: 17825558 PMCID: PMC2084209 DOI: 10.1016/j.cub.2007.08.034] [Citation(s) in RCA: 368] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Revised: 08/03/2007] [Accepted: 08/06/2007] [Indexed: 10/22/2022]
Abstract
The assembly of primary cilia is dependent on intraflagellar transport (IFT), which mediates the bidirectional movement of proteins between the base and tip of the cilium. In mice, congenic mutations disrupting genes required for IFT (e.g., Tg737 or the IFT kinesin Kif3a) are embryonic lethal, whereas kidney-specific disruption of IFT results in severe, rapidly progressing cystic pathology. Although the function of primary cilia in most tissues is unknown, in the kidney they are mechanosenstive organelles that detect fluid flow through the tubule lumen. The loss of this flow-induced signaling pathway is thought to be a major contributing factor to cyst formation. Recent data also suggest that there is a connection between ciliary dysfunction and obesity as evidenced by the discovery that proteins associated with human obesity syndromes such as Alström and Bardet-Biedl localize to this organelle. To more directly assess the importance of cilia in postnatal life, we utilized conditional alleles of two ciliogenic genes (Tg737 and Kif3a) to systemically induce cilia loss in adults. Surprisingly, the cystic kidney pathology in these mutants is dependent on the time at which cilia loss was induced, suggesting that cyst formation is not simply caused by impaired mechanosensation. In addition to the cystic pathology, the conditional cilia mutant mice become obese, are hyperphagic, and have elevated levels of serum insulin, glucose, and leptin. We further defined where in the body cilia are required for normal energy homeostasis by disrupting cilia on neurons throughout the central nervous system and on pro-opiomelanocortin-expressing cells in the hypothalamus, both of which resulted in obesity. These data establish that neuronal cilia function in a pathway regulating satiety responses.
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Affiliation(s)
| | - Amanda J. Watts
- Department of Nutrition Sciences, University of Alabama at Birmingham
| | - Venus C. Roper
- Department of Cell Biology, University of Alabama at Birmingham
| | - Mandy J. Croyle
- Department of Cell Biology, University of Alabama at Birmingham
| | | | - J. Michael Wyss
- Department of Cell Biology, University of Alabama at Birmingham
| | - Tim R. Nagy
- Department of Nutrition Sciences, University of Alabama at Birmingham
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