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Jagdale AD, Angal MM, Patil RS, Tupe RS. Exploring the glycation association with dyslipidaemia: Novel approach for diabetic nephropathy. Biochem Pharmacol 2024; 229:116513. [PMID: 39218042 DOI: 10.1016/j.bcp.2024.116513] [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: 05/21/2024] [Revised: 08/14/2024] [Accepted: 08/29/2024] [Indexed: 09/04/2024]
Abstract
The transcription factor known as sterol regulatory element-binding protein (SREBP) and the glycation pathways, specifically the formation of Advanced Glycation End Products (AGEs), have a significant and deleterious impact on the kidney. They alter renal lipid metabolism and promote glomerulosclerosis, mesangial cell expansion, tubulointerstitial fibrosis, and inflammation, leading to diabetic nephropathy (DN) progression. Although several pieces of scientific evidence are reported for potential causes of glycation and lipotoxicity in DN, the underlying mechanism of renal lipid accumulation still needs to be fully understood. We provide a rationalized view on how AGEs exert multiple effects that cause SREBP activation and inflammation, contributing to DN through Receptor for AGEs (RAGE) signaling, AGE-R1-dependent downregulation of Sirtuin 1 (SIRT-1), and increased SREBP Cleavage Activating Protein (SCAP) glycosylation. This review emphasizes the association between glycation and the SREBP pathway and how it affects the onset of DN associated with obesity. Finally, we discuss the correlation of glycation and the SREBP pathway with insulin resistance (IR), oxidative stress, endoplasmic reticulum stress, inflammation, and existing and emerging therapeutic approaches toward better controlling obesity-related DN.
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Affiliation(s)
- Ashwini D Jagdale
- Symbiosis School of Biological Sciences (SSBS), Symbiosis International (Deemed University) (SIU), Lavale, Pune, Maharashtra, India
| | - Mukul M Angal
- Symbiosis School of Biological Sciences (SSBS), Symbiosis International (Deemed University) (SIU), Lavale, Pune, Maharashtra, India
| | - Rahul S Patil
- Vascular Biology Center, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Rashmi S Tupe
- Symbiosis School of Biological Sciences (SSBS), Symbiosis International (Deemed University) (SIU), Lavale, Pune, Maharashtra, India.
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2
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Assari S, Najand B, Khatami SM. High Systolic Blood Pressure of High-Income African American Children. J Racial Ethn Health Disparities 2024; 11:1994-2008. [PMID: 37418111 PMCID: PMC11236934 DOI: 10.1007/s40615-023-01668-5] [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: 04/11/2023] [Revised: 05/24/2023] [Accepted: 05/29/2023] [Indexed: 07/08/2023]
Abstract
BACKGROUND According to the Minorities' Diminished Returns (MDRs) theory, racism may reduce the health returns of family socioeconomic status (SEP) resources such as family income for racial minorities, particularly African Americans, compared to Whites. However, we are unaware of any previous studies on racial variation in the protective effects of family income on children's blood pressure. AIM We conducted this study to compare the overall effects of family income on pre-adolescents' systolic and diastolic blood pressure, test racial variation in this effect, and investigate whether racial variation in this regard is due to racial differences in body mass index. METHODS In this cross-sectional study, we analyzed data from 4007 racially diverse US children 9-10 years old. The independent variable was family income measured as a three-level categorical variable: less than $50 K USD, 50-100 K USD, and 100 + K USD. The primary outcomes were systolic and diastolic blood pressure measured up to three times at 1-min time intervals. Body mass index was the mediator. Mixed-effects regression models were used for data analysis to adjust for data nested to the centers, families, and individuals. Age, gender, parental education, family structure, and Latino ethnicity were covariates. RESULTS In the pooled sample and in the absence of interaction terms in the model, family income did not show an inverse association with children's systolic (for 100 + K USD family income: β = - 0.71, p = 0.233 and for 50-100 K USD family income: β = 0.01, p = 0.989) or diastolic blood pressure (for 100 + K USD family income: β = - 0.66, p = 0.172 and for 50-100 K USD family income: β = 0.23, p = 0.600). However, race showed a significant interaction with family income on systolic blood pressure (for 50-100 K USD × African American: β = 2.75, p = 0.034), suggesting higher systolic blood pressure of African American adolescents from high-income backgrounds. Racial variation in the protective effect of family income on systolic BP was no more significant (for 50-100 K USD × African American: β = 2.14, p = 0.149) after we controlled for body mass index (BMI), which was higher for African American than White adolescents. CONCLUSION The association between high family income and reduced systolic blood pressure in pre-adolescence might be weaker for African Americans compared to Whites, a difference that African American adolescents' higher body mass index can explain.
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Affiliation(s)
- Shervin Assari
- Department of Family Medicine, Charles R Drew University of Medicine and Science, 1731 E 120Th St, Los Angeles, CA, 90059, USA.
- Department of Urban Public Health, Charles R Drew University of Medicine and Science, Los Angeles, CA, USA.
- School of Nursing, Charles R. Drew University of Medicine and Science, Los Angeles, CA, USA.
- Marginalization-Related Diminished Returns (MDRs), Los Angeles, CA, USA.
| | - Babak Najand
- Marginalization-Related Diminished Returns (MDRs), Los Angeles, CA, USA
| | - Seyedeh Mohaddeseh Khatami
- Marginalization-Related Diminished Returns (MDRs), Los Angeles, CA, USA
- Department of Internal Medicine, University of Toronto, Toronto, Ontario, Canada
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3
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Ye B, Zhang J, Tan Z, Chen J, Pan X, Zhou Y, Wang W, Liu L, Zhu W, Sun Y, Ning K, Xie Q, Liu R. Association of liver function with health-related physical fitness: a cross-sectional study. BMC Public Health 2023; 23:1797. [PMID: 37715140 PMCID: PMC10503162 DOI: 10.1186/s12889-023-16701-9] [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: 02/14/2023] [Accepted: 09/05/2023] [Indexed: 09/17/2023] Open
Abstract
BACKGROUND In this study, by analyzing the correlation between various components of health-related physical fitness (HPF) and liver function indicators, the indicators of physical fitness that were highly correlated with liver function and could be monitored at home were screened to prevent more serious liver disease in the future, and to provide experimental basis for prescribing personalized exercise. METHODS A total of 330 faculties (female = 198) of a university were recruited. The indicators of HPF and liver function were measured. Spearman correlation analysis, multivariate linear regression, and cross-lagged panel model was used to data statistics. RESULTS In males, body fat (BF) was positively correlated with alanine aminotransferase (ALT); vital capacity and the vital capacity index were positively correlated with albumin; and vertical jump was positively correlated with globulin and negatively correlated with the albumin-globulin ratio (P < 0.05). However, there was no significant correlation among all indicators controlled confounding factors. In females, BF was negatively correlated with direct bilirubin; VO2max was positively correlated with indirect bilirubin; and vertical jump was positively correlated with the albumin-globulin ratio and significantly negatively correlated with globulin (P < 0.05). Controlled confounding factors, body fat percentage was positively correlated with globulin (β = 0.174) and negatively correlated with direct bilirubin (β = -0.431), and VO2max was positively correlated with indirect bilirubin (β = 0.238, P < 0.05). Cross-lagged panel analysis showed that BF percentage can negatively predict direct bilirubin levels with great significance (β = -0.055, P < 0.05). CONCLUSIONS HPF may play a crucial role in liver function screening, particularly for female faculty members. For males, BF, vertical jump, vital capacity and vital capacity index could be associated with liver function but are susceptible to complex factors such as age, smoking, diabetes, and hypertension. In females, BF percentage is an important predictor of abnormal liver function in addition to VO2max and vertical jump, which are not affected by complex factors.
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Affiliation(s)
- Bo Ye
- School of Physical Education, Shaanxi Normal University, Xi'an, China
| | - Jing Zhang
- School of Physical Education, Shaanxi Normal University, Xi'an, China.
| | - Zeyu Tan
- Department of Life Sciences, University of California Los Angeles, Los Angeles, USA
| | - Jiangang Chen
- School of Physical Education and Sports, Beijing Normal University, Beijing, China
| | - Xinliang Pan
- School of Kinesiology, Beijing Sport University, Beijing, China
| | - Yuan Zhou
- School of Physical Education, Shaanxi Normal University, Xi'an, China
| | - Wanwan Wang
- School of Physical Education, Shaanxi Normal University, Xi'an, China
| | - Longlong Liu
- School of Physical Education, Shaanxi Normal University, Xi'an, China
| | - Wenfei Zhu
- School of Physical Education, Shaanxi Normal University, Xi'an, China
| | - Yuliang Sun
- School of Physical Education, Shaanxi Normal University, Xi'an, China
| | - Ke Ning
- School of Physical Education, Shaanxi Normal University, Xi'an, China
| | - Qian Xie
- School of Physical Education, Shaanxi Normal University, Xi'an, China
| | - Ronghua Liu
- School of Physical Education, Shaanxi Normal University, Xi'an, China
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4
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Sakr HF, Sirasanagandla SR, Das S, Bima AI, Elsamanoudy AZ. Insulin Resistance and Hypertension: Mechanisms Involved and Modifying Factors for Effective Glucose Control. Biomedicines 2023; 11:2271. [PMID: 37626767 PMCID: PMC10452601 DOI: 10.3390/biomedicines11082271] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 07/18/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
Factors such as aging, an unhealthy lifestyle with decreased physical activity, snacking, a standard Western diet, and smoking contribute to raising blood pressure to a dangerous level, increasing the risk of coronary artery disease and heart failure. Atherosclerosis, or aging of the blood vessels, is a physiological process that has accelerated in the last decades by the overconsumption of carbohydrates as the primary sources of caloric intake, resulting in increased triglycerides and VLDL-cholesterol and insulin spikes. Classically, medications ranging from beta blockers to angiotensin II blockers and even calcium channel blockers were used alone or in combination with lifestyle modifications as management tools in modern medicine to control arterial blood pressure. However, it is not easy to control blood pressure or the associated complications. A low-carbohydrate, high-fat (LCHF) diet can reduce glucose and insulin spikes, improve insulin sensitivity, and lessen atherosclerosis risk factors. We reviewed articles describing the etiology of insulin resistance (IR) and its impact on arterial blood pressure from databases including PubMed, PubMed Central, and Google Scholar. We discuss how the LCHF diet is beneficial to maintaining arterial blood pressure at normal levels, slowing down the progression of atherosclerosis, and reducing the use of antihypertensive medications. The mechanisms involved in IR associated with hypertension are also highlighted.
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Affiliation(s)
- Hussein F. Sakr
- Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat 123, Oman
| | - Srinivasa Rao Sirasanagandla
- Department of Human and Clinical Anatomy, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat 123, Oman; (S.R.S.); (S.D.)
| | - Srijit Das
- Department of Human and Clinical Anatomy, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat 123, Oman; (S.R.S.); (S.D.)
| | - Abdulhadi I. Bima
- Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah 21465, Saudi Arabia; (A.I.B.); (A.Z.E.)
| | - Ayman Z. Elsamanoudy
- Department of Clinical Biochemistry, Faculty of Medicine, King Abdulaziz University, Jeddah 21465, Saudi Arabia; (A.I.B.); (A.Z.E.)
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Chen X, Liu P, Zhang W, Li X, Wang C, Han F, Liu W, Huang Y, Li M, Li Y, Sun X, Fan X, Li W, Xiong Y, Qian L. ETNPPL modulates hyperinsulinemia-induced insulin resistance through the SIK1/ROS-mediated inactivation of the PI3K/AKT signaling pathway in hepatocytes. J Cell Physiol 2023; 238:1046-1062. [PMID: 36924049 DOI: 10.1002/jcp.30993] [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: 11/23/2022] [Revised: 02/16/2023] [Accepted: 02/27/2023] [Indexed: 03/18/2023]
Abstract
Hyperinsulinemia is a critical risk factor for the pathogenesis of insulin resistance (IR) in metabolic tissues, including the liver. Ethanolamine phosphate phospholyase (ETNPPL), a newly discovered metabolic enzyme that converts phosphoethanolamine (PEA) to ammonia, inorganic phosphate, and acetaldehyde, is abundantly expressed in liver tissue. Whether it plays a role in the regulation of hyperinsulinemia-induced IR in hepatocytes remains elusive. Here, we established an in vitro hyperinsulinemia-induced IR model in the HepG2 human liver cancer cell line and primary mouse hepatocyte via a high dose of insulin treatment. Next, we overexpressed ETNPPL by using lentivirus-mediated ectopic to investigate the effects of ETNPPL per se on IR without insulin stimulation. To explore the underlying mechanism of ETNPPL mediating hyperinsulinemia-induced IR in HepG2, we performed genome-wide transcriptional analysis using RNA sequencing (RNA-seq) to identify the downstream target gene of ETNPPL. The results showed that ETNPPL expression levels in both mRNA and protein were significantly upregulated in hyperinsulinemia-induced IR in HepG2 and primary mouse hepatocytes. Upon silencing ETNPPL, hyperinsulinemia-induced IR was ameliorated. Under normal conditions without IR in hepatocytes, overexpressing ETNPPL promotes IR, reactive oxygen species (ROS) generation, and AKT inactivation. Transcriptome analysis revealed that salt-inducible kinase 1 (SIK1) is markedly downregulated in the ETNPPL knockdown HepG2 cells. Moreover, disrupting SIK1 prevents ETNPPL-induced ROS accumulation, damage to the PI3K/AKT pathway and IR. Our study reveals that ETNPPL mediates hyperinsulinemia-induced IR through the SIK1/ROS-mediated inactivation of the PI3K/AKT signaling pathway in hepatocyte cells. Targeting ETNPPL may present a potential strategy for hyperinsulinemia-associated metabolic disorders such as type 2 diabetes.
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Affiliation(s)
- Xueyi Chen
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Faculty of Life Sciences and Medicine, Northwest University, Shaanxi, Xi'an, China
| | - Ping Liu
- Department of Endocrinology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, P.R. China
| | - Wei Zhang
- Department of Endocrinology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, P.R. China
| | - Xiaofang Li
- Department of Gastroenterology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, P.R. China
| | - Caihua Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Faculty of Life Sciences and Medicine, Northwest University, Shaanxi, Xi'an, China
| | - Feifei Han
- Department of Endocrinology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, P.R. China
| | - Wenxuan Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Faculty of Life Sciences and Medicine, Northwest University, Shaanxi, Xi'an, China
| | - Yaoyao Huang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Faculty of Life Sciences and Medicine, Northwest University, Shaanxi, Xi'an, China
| | - Man Li
- Department of Endocrinology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, P.R. China
| | - Yujia Li
- Department of Endocrinology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, P.R. China
| | - Xiaomin Sun
- Department of Endocrinology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, P.R. China
| | - Xiaobin Fan
- Department of Obstetrics and Gynecology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, P.R. China
| | - Wenqing Li
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Faculty of Life Sciences and Medicine, Northwest University, Shaanxi, Xi'an, China
| | - Yuyan Xiong
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Faculty of Life Sciences and Medicine, Northwest University, Shaanxi, Xi'an, China.,Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, China
| | - Lu Qian
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, Faculty of Life Sciences and Medicine, Northwest University, Shaanxi, Xi'an, China.,Department of Endocrinology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, P.R. China.,Xi'an Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Northwest University, Shaanxi, Xi'an, China
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6
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Soleimani M, Barone S, Luo H, Zahedi K. Pathogenesis of Hypertension in Metabolic Syndrome: The Role of Fructose and Salt. Int J Mol Sci 2023; 24:4294. [PMID: 36901725 PMCID: PMC10002086 DOI: 10.3390/ijms24054294] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023] Open
Abstract
Metabolic syndrome is manifested by visceral obesity, hypertension, glucose intolerance, hyperinsulinism, and dyslipidemia. According to the CDC, metabolic syndrome in the US has increased drastically since the 1960s leading to chronic diseases and rising healthcare costs. Hypertension is a key component of metabolic syndrome and is associated with an increase in morbidity and mortality due to stroke, cardiovascular ailments, and kidney disease. The pathogenesis of hypertension in metabolic syndrome, however, remains poorly understood. Metabolic syndrome results primarily from increased caloric intake and decreased physical activity. Epidemiologic studies show that an enhanced consumption of sugars, in the form of fructose and sucrose, correlates with the amplified prevalence of metabolic syndrome. Diets with a high fat content, in conjunction with elevated fructose and salt intake, accelerate the development of metabolic syndrome. This review article discusses the latest literature in the pathogenesis of hypertension in metabolic syndrome, with a specific emphasis on the role of fructose and its stimulatory effect on salt absorption in the small intestine and kidney tubules.
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Affiliation(s)
- Manoocher Soleimani
- Research Services, New Mexico Veterans Health Care Medical Center, Albuquerque, NM 87108, USA
- Department of Medicine, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA
| | - Sharon Barone
- Research Services, New Mexico Veterans Health Care Medical Center, Albuquerque, NM 87108, USA
- Department of Medicine, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA
| | - Henry Luo
- Department of Medicine, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA
| | - Kamyar Zahedi
- Research Services, New Mexico Veterans Health Care Medical Center, Albuquerque, NM 87108, USA
- Department of Medicine, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA
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7
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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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8
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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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9
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Zhou C, Wu Q, Ye Z, Liu M, Zhang Z, Zhang Y, Li H, He P, Li Q, Liu C, Qin X. Inverse Association Between Variety of Proteins With Appropriate Quantity From Different Food Sources and New-Onset Hypertension. Hypertension 2022; 79:1017-1027. [PMID: 35264000 DOI: 10.1161/hypertensionaha.121.18222] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The relationships of the variety and quantity of different sources of dietary proteins with hypertension remain uncertain. We aimed to investigate associations between the variety and quantity of proteins intake from 8 major food sources and new-onset hypertension among 12 177 participants from the China Health and Nutrition Survey. Dietary intake was measured by 3 consecutive 24-hour dietary recalls combined with a household food inventory. The variety score of protein sources was defined as the number of protein sources consumed at the appropriate level, accounting for types and quantity of proteins. New-onset hypertension was defined as systolic blood pressure ≥140 mm Hg and diastolic blood pressure ≥90 mm Hg, or physician-diagnosed hypertension or receiving antihypertensive treatment, during the follow-up. During a median follow-up of 6.1 years, there were U-shaped associations of percentages energy from total, unprocessed or processed red meat-derived, whole grain-derived, and poultry-derived proteins with new-onset hypertension; an reverse J-shaped association of fish-derived protein with new-onset hypertension; L-shaped associations of eggs-derived and legumes-derived proteins with new-onset hypertension; and an reverse L-shaped association of refined grain-derived protein with new-onset hypertension (all P values for nonlinearity <0.001). That is, for each protein, there is a window of consumption (appropriate level) where the risk of hypertension is lower. Moreover, a significantly lower risk of new-onset hypertension was found in those with higher variety score of protein sources (per score increment, hazard ratio, 0.74 [95% CI, 0.72-0.76]). In summary, there was an inverse association between the variety of proteins with appropriate quantity from different food sources and new-onset hypertension.
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Affiliation(s)
- Chun Zhou
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.)
| | - Qimeng Wu
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.)
| | - Ziliang Ye
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.)
| | - Mengyi Liu
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.)
| | - Zhuxian Zhang
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.)
| | - Yuanyuan Zhang
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.)
| | - Huan Li
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.)
| | - Panpan He
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.)
| | - Qinqin Li
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.).,Department of Epidemiology and Biostatistics, School of Public Health (Q.L., C.L., X.Q.), Anhui Medical University, Hefei, China.,Institute of Biomedicine (Q.L., C.L., X.Q.), Anhui Medical University, Hefei, China
| | - Chengzhang Liu
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.).,Department of Epidemiology and Biostatistics, School of Public Health (Q.L., C.L., X.Q.), Anhui Medical University, Hefei, China.,Institute of Biomedicine (Q.L., C.L., X.Q.), Anhui Medical University, Hefei, China
| | - Xianhui Qin
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, China (C.Z., Q.W., Z.Y., M.L., Z.Z., Y.Z., H.L., P.H., Q.L., C.L., X.Q.).,Department of Epidemiology and Biostatistics, School of Public Health (Q.L., C.L., X.Q.), Anhui Medical University, Hefei, China.,Institute of Biomedicine (Q.L., C.L., X.Q.), Anhui Medical University, Hefei, China
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10
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Ramesh R, Pandurangan V, Madhavan S, Srinivasan D, Bhaskar E, Marappa L, Nair AM, Rajendran V, Varadaraj P. Comparison of Fasting Insulin Level, Homeostatic Model of Insulin Resistance, and Lipid Levels between Patients with Primary Hypertension and Normotensive Subjects. Rambam Maimonides Med J 2022; 13:RMMJ.10468. [PMID: 35482462 PMCID: PMC9049152 DOI: 10.5041/rmmj.10468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Hyperinsulinemia and insulin resistance occurs in obese patients with primary hypertension independent of diabetes and obesity. This study was aimed at assessing serum fasting insulin levels, the homeostatic model assessment for insulin resistance (HOMA-IR), and serum lipid levels in non-obese patients with primary hypertension when compared to normotensive subjects. METHODS This observational study comprised 100 patients over 18 years of age, divided into two groups. The hypertensive group comprised non-obese patients with primary hypertension (n=50); the normotensive group comprised normotensive age- and sex-matched individuals (n=50). Patients with diabetes, impaired fasting glucose, obesity, and other causative factors of insulin resistance were excluded from the study. Serum fasting insulin levels and fasting lipid profiles were measured, and insulin resistance was calculated using HOMA-IR. These data were compared between the two groups. Pearson's correlation coefficient was used to assess the extent of a linear relationship between HOMA-IR and to evaluate the association between HOMA-IR and systolic and diastolic blood pressures. RESULTS Mean serum fasting insulin levels (mIU/L), mean HOMA-IR values, and fasting triglyceride levels (mg/dL) were significantly higher in the hypertensive versus normotensive patients (10.32 versus 6.46, P<0.001; 1.35 versus 0.84, P<0.001; 113.70 versus 97.04, P=0.005, respectively). The HOMA-IR levels were associated with systolic blood pressure (r value 0.764, P=0.0005). CONCLUSION We observed significantly higher fasting insulin levels, serum triglyceride levels, and HOMA-IR reflecting hyperinsulinemia and possibly an insulin-resistant state among primary hypertension patients with no other causally linked factors for insulin resistance. We observed a significant correlation between systolic blood pressure and HOMA-IR.
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Affiliation(s)
| | - Viswanathan Pandurangan
- Corresponding Author: Please address correspondence to Viswanathan Pandurangan, Assistant Professor, Department of General Medicine, SRMC&RI, Porur, Chennai, India. E-mail:
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11
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Mizuno T, Satoh N, Horita S, Tsukada H, Takagi M, Sato Y, Kume H, Nangaku M, Nakamura M. Oxidized alkyl phospholipids stimulate sodium transport in proximal tubules via a non-genomic PPARγ-dependent pathway. J Biol Chem 2022; 298:101681. [PMID: 35124009 PMCID: PMC8892145 DOI: 10.1016/j.jbc.2022.101681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 01/29/2022] [Accepted: 02/01/2022] [Indexed: 11/22/2022] Open
Abstract
Oxidized phospholipids have been shown to exhibit pleiotropic effects in numerous biological contexts. For example, 1-O-hexadecyl-2-azelaoyl-sn-glycero-3-phosphocholine (azPC), an oxidized phospholipid formed from alkyl phosphatidylcholines, is a peroxisome proliferator–activated receptor gamma (PPARγ) nuclear receptor agonist. Although it has been reported that PPARγ agonists including thiazolidinediones can induce plasma volume expansion by enhancing renal sodium and water retention, the role of azPC in renal transport functions is unknown. In the present study, we investigated the effect of azPC on renal proximal tubule (PT) transport using isolated PTs and kidney cortex tissues and also investigated the effect of azPC on renal sodium handling in vivo. We showed using a microperfusion technique that azPC rapidly stimulated Na+/HCO3− cotransporter 1 (NBCe1) and luminal Na+/H+ exchanger (NHE) activities in a dose-dependent manner at submicromolar concentrations in isolated PTs from rats and humans. The rapid effects (within a few minutes) suggest that azPC activates NBCe1 and NHE via nongenomic signaling. The stimulatory effects were completely blocked by specific PPARγ antagonist GW9662, ERK kinase inhibitor PD98059, and CD36 inhibitor sulfosuccinimidyl oleate. Treatment with an siRNA against PPAR gamma completely blocked the stimulation of both NBCe1 and NHE by azPC. Moreover, azPC induced ERK phosphorylation in rat and human kidney cortex tissues, which were completely suppressed by GW9662 and PD98059 treatments. These results suggest that azPC stimulates renal PT sodium-coupled bicarbonate transport via a CD36/PPARγ/mitogen-activated protein/ERK kinase/ERK pathway. We conclude that the stimulatory effects of azPC on PT transport may be partially involved in volume expansion.
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12
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Ertuglu LA, Elijovich F, Laffer CL, Kirabo A. Salt-Sensitivity of Blood Pressure and Insulin Resistance. Front Physiol 2021; 12:793924. [PMID: 34966295 PMCID: PMC8711096 DOI: 10.3389/fphys.2021.793924] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 11/18/2021] [Indexed: 12/20/2022] Open
Abstract
Salt sensitivity of blood pressure (SSBP) is an independent risk factor for cardiovascular morbidity and mortality that is seen in both hypertensive and normotensive populations. Insulin resistance (IR) strongly correlates with SSBP and affects nearly 50% of salt sensitive people. While the precise mechanism by which IR and SSBP relate remains elusive, several common pathways are involved in the genesis of both processes, including vascular dysfunction and immune activation. Vascular dysfunction associated with insulin resistance is characterized by loss of nitric oxide (NO)-mediated vasodilation and heightened endothelin-1 induced vasoconstriction, as well as capillary rarefaction. It manifests with increased blood pressure (BP) in salt sensitive murine models. Another common denominator in the pathogenesis of insulin resistance, hypertension, and salt sensitivity (SS) is immune activation involving pro-inflammatory cytokines like tumor necrosis factor (TNF)-α, IL-1β, and IL-6. In the last decade, a new understanding of interstitial sodium storage in tissues such as skin and muscle has revolutionized traditional concepts of body sodium handling and pathogenesis of SS. We have shown that interstitial Na+ can trigger a T cell mediated inflammatory response through formation of isolevuglandin protein adducts in antigen presenting cells (APCs), and that this response is implicated in salt sensitive hypertension. The peroxisome proliferator-activated receptor γ (PPARγ) is a transcription factor that modulates both insulin sensitivity and BP. PPARγ agonists increase insulin sensitivity and ameliorate salt sensitivity, whereas deficiency of PPARγ results in severe insulin resistance and hypertension. These findings suggest that PPARγ plays a role in the common pathogenesis of insulin sensitivity and salt sensitivity, perhaps via effects on the immune system and vascular function. The goal of this review is to discuss those mechanisms that may play a role in both SSBP and in insulin resistance.
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Affiliation(s)
- Lale A Ertuglu
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Fernando Elijovich
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Cheryl L Laffer
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
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13
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Ekun OA, Oyekunle AO, Igbadumhe CO. Evaluation of peroxisome proliferator-activated receptor-gamma (Ppar-γ) and metabolic dysfunction among hypertensive nigerians. ENDOCRINE AND METABOLIC SCIENCE 2021. [DOI: 10.1016/j.endmts.2021.100108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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14
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Lambie M, Bonomini M, Davies SJ, Accili D, Arduini A, Zammit V. Insulin resistance in cardiovascular disease, uremia, and peritoneal dialysis. Trends Endocrinol Metab 2021; 32:721-730. [PMID: 34266706 PMCID: PMC8893168 DOI: 10.1016/j.tem.2021.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 06/03/2021] [Accepted: 06/15/2021] [Indexed: 02/09/2023]
Abstract
Diabetic nephropathy is highly correlated with the occurrence of other complications of type 1 diabetes (T1D) and type 2 diabetes (T2D) mellitus; for example, hypertension with cardiovascular disease (CVD) being the most frequent cause of death in patients with end-stage renal disease and undergoing renal dialysis. Hyperglycemia and insulin resistance (IR) are responsible for the micro- and macrovascular complications of diabetes through different mechanisms. In particular, IR plays a key role in the etiology of atherosclerosis in both diabetic and non-diabetic patients. IR - exacerbated by organ-level selectivity - is more important than glycemic control per se in determining cardiovascular outcomes. This may be exacerbated by the fact that IR is organ and pathway specific due to the only selective loss of sensitivity to insulin action of specific pathways/processes. Therefore, it is counterintuitive that the use of peritoneal dialysis (PD) in (frequently) diabetic renal disease patients should involve their exposure to high daily doses of glucose peritoneally. In view of the controversy about the causal association between glucose load and CVD in PD patients, we discuss the role that selective IR may play in the progression of CVD in diabetic renal end-stage patients. In discussing these associations, we propose that reducing glucose exposure in PD solutions may be beneficial especially if coupled with strategies that address IR directly, and the avoidance of excessive use of insulin treatment in T2D.
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Affiliation(s)
- Mark Lambie
- Faculty of Medicine and Health Sciences, Keele University, Keele ST5 5BG, UK
| | - Mario Bonomini
- Department of Medicine, G. d'Annunzio University, Chieti 66100, Italy
| | - Simon J Davies
- Faculty of Medicine and Health Sciences, Keele University, Keele ST5 5BG, UK
| | - Domenico Accili
- Columbia University College of Physicians and Surgeons, Department of Medicine, New York, NY 10032, USA
| | | | - Victor Zammit
- Translational & Experimental Medicine, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK.
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15
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Ali MY, Zaib S, Jannat S, Khan I. Inhibition of Angiotensin-I Converting Enzyme by Ginsenosides: Structure-Activity Relationships and Inhibitory Mechanism. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:6073-6086. [PMID: 34014666 DOI: 10.1021/acs.jafc.1c01231] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Ginseng (Panax ginseng C. A. Meyer) extract has been reported to inhibit the angiotensin converting enzyme (ACE); however, the possible inhibitory action of most of its constituents (ginsenosides) against ACE remains unknown. Thus, in this study, we investigated ginsenoside derivatives' inhibitory effect on ACE. We assessed the activities of 22 ginsenosides, most of which inhibited ACE significantly. Notably, protopanaxatriol, protopanaxadiol, and ginsenoside Rh2 exhibited the most potent ACE inhibitory potential, with IC50 values of 1.57, 2.22, and 5.60 μM, respectively. Further, a kinetic study revealed different modes of inhibition against ACE. Molecular docking studies have confirmed that ginsenosides inhibit ACE via many hydrogen bonds and hydrophobic interactions with catalytic residues and zinc ion of C- and N-domain ACE that block the catalytic activity of ACE. In addition, we found that the active ginsenosides stimulated glucose uptake in insulin-resistant C2C12 skeletal muscle cells in a dose-dependent manner. Moreover, the most active ginsenosides' reactive oxygen species (ROS) and peroxynitrite (ONOO-) scavenging properties were evaluated, in which IC50 values ranged from 1.44-43.83 to 2.36-39.56 μM in ONOO- and ROS, respectively. The results derived from these computational and in vitro experiments provide additional scientific support for the anecdotal use of ginseng in traditional medicine to treat cardiovascular diseases such as hypertension.
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Affiliation(s)
- Md Yousof Ali
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada
| | - Sumera Zaib
- Department of Biochemistry, Faculty of Life Sciences, University of Central Punjab, Lahore 54590, Pakistan
| | - Susoma Jannat
- Department of Biochemistry and Molecular Biology, University of Calgary, T2N 1N4 Alberta, Canada
| | - Imtiaz Khan
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
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16
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Lee HJ, Mariappan MM, Norton L, Bakewell T, Feliers D, Oh SB, Donati A, Rubannelsonkumar CS, Venkatachalam MA, Harris SE, Rubera I, Tauc M, Ghosh Choudhury G, Kahn CR, Sharma K, DeFronzo RA, Kasinath BS. Proximal tubular epithelial insulin receptor mediates high-fat diet-induced kidney injury. JCI Insight 2021; 6:143619. [PMID: 33400689 PMCID: PMC7934847 DOI: 10.1172/jci.insight.143619] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 12/29/2020] [Indexed: 01/04/2023] Open
Abstract
The role of insulin receptor (IR) activated by hyperinsulinemia in obesity-induced kidney injury is not well understood. We hypothesized that activation of kidney proximal tubule epithelial IR contributes to obesity-induced kidney injury. We administered normal-fat diet (NFD) or high-fat diet (HFD) to control and kidney proximal tubule IR–knockout (KPTIRKO) mice for 4 months. Renal cortical IR expression was decreased by 60% in male and female KPTIRKO mice. Baseline serum glucose, serum creatinine, and the ratio of urinary albumin to creatinine (ACR) were similar in KPTIRKO mice compared to those of controls. On HFD, weight gain and increase in serum cholesterol were similar in control and KPTIRKO mice; blood glucose did not change. HFD increased the following parameters in the male control mice: renal cortical contents of phosphorylated IR and Akt, matrix proteins, urinary ACR, urinary kidney injury molecule-1–to-creatinine ratio, and systolic blood pressure. Renal cortical generation of hydrogen sulfide was reduced in HFD-fed male control mice. All of these parameters were ameliorated in male KPTIRKO mice. Interestingly, female mice were resistant to HFD-induced kidney injury in both genotypes. We conclude that HFD-induced kidney injury requires renal proximal tubule IR activation in male mice.
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Affiliation(s)
- Hak Joo Lee
- Center for Renal Medicine, Division of Nephrology
| | | | - Luke Norton
- Division of Diabetes, Department of Medicine
| | | | | | - Sae Byeol Oh
- Center for Renal Medicine, Division of Nephrology
| | | | | | | | - Stephen E Harris
- Department of Periodontics, University of Texas Health, San Antonio, Texas, USA
| | - Isabelle Rubera
- Universite Cote d'Azur, CNRS - UMR-7370, Laboratoire de Physiomédecine Moléculaire, Nice, France
| | - Michel Tauc
- Universite Cote d'Azur, CNRS - UMR-7370, Laboratoire de Physiomédecine Moléculaire, Nice, France
| | - Goutam Ghosh Choudhury
- Center for Renal Medicine, Division of Nephrology.,VA Research and.,Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas, USA
| | - C Ronald Kahn
- Joslin Diabetes Center and Harvard Medical School, Boston, Massachusetts, USA
| | - Kumar Sharma
- Center for Renal Medicine, Division of Nephrology.,VA Research and
| | | | - Balakuntalam S Kasinath
- Center for Renal Medicine, Division of Nephrology.,VA Research and.,Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, Texas, USA
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17
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Nakamura M, Satoh N, Tsukada H, Mizuno T, Fujii W, Suzuki A, Horita S, Nangaku M, Suzuki M. Stimulatory effect of insulin on H+-ATPase in the proximal tubule via the Akt/mTORC2 pathway. Physiol Int 2020; 107:376-389. [PMID: 32990653 DOI: 10.1556/2060.2020.00030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 06/12/2020] [Indexed: 11/19/2022]
Abstract
Purpose Acid-base transport in renal proximal tubules (PTs) is mainly sodium-dependent and conducted in coordination by the apical Na+/H+ exchanger (NHE3), vacuolar H+-adenosine triphosphatase (V-ATPase), and the basolateral Na+/HCO3- cotransporter. V-ATPase on PTs is well-known to play an important role in proton excretion. Recently we reported a stimulatory effect of insulin on these transporters. However, it is unclear whether insulin is involved in acid-base balance in PTs. Thus, we assessed the role of insulin in acid-base balance in PTs. Methods V-ATPase activity was evaluated using freshly isolated PTs obtained from mice, and specific inhibitors were then used to assess the signaling pathways involved in the observed effects. Results V-ATPase activity in PTs was markedly enhanced by insulin, and its activation was completely inhibited by bafilomycin (a V-ATPase-specific inhibitor), Akt inhibitor VIII, and PP242 (an mTORC1/2 inhibitor), but not by rapamycin (an mTORC1 inhibitor). V-ATPase activity was stimulated by 1 nm insulin by approximately 20% above baseline, which was completely suppressed by Akt1/2 inhibitor VIII. PP242 completely suppressed the insulin-mediated V-ATPase stimulation in mouse PTs, whereas rapamycin failed to influence the effect of insulin. Insulin-induced Akt phosphorylation in the mouse renal cortex was completely suppressed by Akt1/2 inhibitor VIII and PP242, but not by rapamycin. Conclusion Our results indicate that stimulation of V-ATPase activity by insulin in PTs is mediated via the Akt2/mTORC2 pathway. These results reveal the mechanism underlying the complex signaling in PT acid-base balance, providing treatment targets for renal disease.
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Affiliation(s)
- M Nakamura
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - N Satoh
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - H Tsukada
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - T Mizuno
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - W Fujii
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - A Suzuki
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan.,2Department of Nephrology, Japan Community Health care Organization (JCHO), Tokyo Yamate Medical Center, Tokyo, Japan
| | - S Horita
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - M Nangaku
- 1Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - M Suzuki
- 3Health Service Center, Tokyo Gakugei University, Tokyo, Japan
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18
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Martins FL, Bailey MA, Girardi ACC. Endogenous Activation of Glucagon-Like Peptide-1 Receptor Contributes to Blood Pressure Control: Role of Proximal Tubule Na +/H + Exchanger Isoform 3, Renal Angiotensin II, and Insulin Sensitivity. Hypertension 2020; 76:839-848. [PMID: 32755467 DOI: 10.1161/hypertensionaha.120.14868] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The pharmacological administration of GLP-1R (glucagon-like peptide-1 receptor) agonists reduces blood pressure (BP) in type 2 diabetes mellitus and nondiabetic patients. This study tested the hypothesis that endogenous GLP-1R signaling influences the regulation of BP. To this end, SHRs (spontaneously hypertensive rats) and Wistar rats were treated with the GLP-1R antagonist Ex9 (exendin-9) or vehicle for 4 weeks. Rats receiving the GLP-1R agonist Ex4 (exenatide) were used as an additional control. We found that blockade of baseline GLP-1R signaling by Ex9 increased systolic BP in both SHR and Wistar rats, compared with vehicle-treated animals, while Ex4 only reduced systolic BP in SHR. Higher systolic BP induced by Ex9 was accompanied by reduced lithium clearance and lower levels of NHE3 (Na+/H+ exchanger isoform 3) phosphorylation at the serine 552, indicative of increased proximal tubule sodium reabsorption. Additionally, urinary AGT (angiotensinogen) and renal cortical concentration of Ang II (angiotensin II) were enhanced by Ex9. Conversely, Ex4 decreased both urinary AGT and cortical Ang II but exclusively in SHRs. Moreover, both SHR and Wistar rats treated with Ex9 displayed hyperinsulinemia as compared with vehicle-treated rats, whereas Ex4 reduced fasting insulin concentration in SHR. Collectively, these results suggest that endogenous GLP-1R signaling exerts a physiologically relevant effect on BP control, which may be attributable, in part, to its tonic actions on the proximal tubule NHE3-mediated sodium reabsorption, intrarenal renin-angiotensin system, and insulin sensitivity. The possible role of impaired GLP-1R signaling in the pathogenesis of hypertension warrants further investigation.
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Affiliation(s)
- Flavia L Martins
- From the Heart Institute (InCor), Medical School, University of São Paulo, Brazil (F.L.M., A.C.C.G.)
| | - Matthew A Bailey
- Centre for Cardiovascular Science, Queen's Medical Research Institute, The University of Edinburgh, United Kingdom (M.A.B.)
| | - Adriana C C Girardi
- From the Heart Institute (InCor), Medical School, University of São Paulo, Brazil (F.L.M., A.C.C.G.)
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19
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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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20
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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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Mitrofanova A, Sosa MA, Fornoni A. Lipid mediators of insulin signaling in diabetic kidney disease. Am J Physiol Renal Physiol 2019; 317:F1241-F1252. [PMID: 31545927 PMCID: PMC6879940 DOI: 10.1152/ajprenal.00379.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/19/2019] [Accepted: 09/19/2019] [Indexed: 12/30/2022] Open
Abstract
Diabetic kidney disease (DKD) affects ∼40% of patients with diabetes and is associated with high mortality rates. Among different cellular targets in DKD, podocytes, highly specialized epithelial cells of the glomerular filtration barrier, are injured in the early stages of DKD. Both clinical and experimental data support the role of preserved insulin signaling as a major contributor to podocyte function and survival. However, little is known about the key modulators of podocyte insulin signaling. This review summarizes the novel knowledge that intracellular lipids such as cholesterol and sphingolipids are major determinants of podocyte insulin signaling. In particular, the implications of these lipids on DKD development, progression, and treatment will be addressed.
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Affiliation(s)
- Alla Mitrofanova
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, Miller School of Medicine, University of Miami, Miami, Florida
- Department of Surgery, Miller School of Medicine, University of Miami, Miami, Florida
| | - Marie Anne Sosa
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
| | - Alessia Fornoni
- Katz Family Division of Nephrology and Hypertension, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida
- Peggy and Harold Katz Family Drug Discovery Center, Miller School of Medicine, University of Miami, Miami, Florida
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Nakamura M, Tsukada H, Seki G, Satoh N, Mizuno T, Fujii W, Horita S, Moriya K, Sato Y, Kume H, Nangaku M, Suzuki M. Insulin promotes sodium transport but suppresses gluconeogenesis via distinct cellular pathways in human and rat renal proximal tubules. Kidney Int 2019; 97:316-326. [PMID: 31735358 DOI: 10.1016/j.kint.2019.08.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 08/02/2019] [Accepted: 08/08/2019] [Indexed: 01/11/2023]
Abstract
Insulin is known to promote sodium transport and regulate gluconeogenesis in renal proximal tubules. Although protein kinase B (also known as Akt) and mammalian target of rapamycin complexes (mTORC) have been established as key regulators in the insulin signaling pathway, their roles in proximal tubules are poorly understood. To help define this, we examined the components of insulin signaling in sodium transport and gluconeogenesis in isolated human and rat proximal tubules, and also investigated the role of insulin in sodium handling and mTORC1 in insulin signaling in vivo. In isolated human and rat proximal tubules, Akt and mTORC1/2 inhibition suppressed insulin-stimulated sodium-bicarbonate co-transporter 1 (NBCe1) activity, whereas mTORC1 inhibition had no effect. Akt2 and mTORC2 gene silencing largely inhibited insulin-stimulated NBCe1 activity, whereas silencing of Akt1 and mTORC1 had no effect. Furthermore, insulin decreased sodium excretion, and this effect depended on phosphoinositide 3 kinase in vivo. Moreover, insulin reduced glucose production in rat proximal tubules and the expression of gluconeogenic genes in human and rat proximal tubules. Akt and mTORC1 inhibition largely abolished the observed insulin-mediated inhibitory effects. Gene silencing of insulin receptor substrate 1 (IRS1), Akt2, mTORC1, and mTORC2 also abolished insulin-mediated inhibition of gluconeogenesis. Additionally, in vivo, mTORC1 inhibition abolished insulin-mediated inhibitory effects in rat proximal tubules, although not in liver. These results indicate that insulin-stimulated proximal tubule sodium transport is mediated via the Akt2/mTORC2 pathway, whereas insulin-suppressed proximal tubule gluconeogenesis is mediated via the IRS1/Akt2/mTORC1/2 pathway. Thus, distinct pathways may play important roles in hypertension and hyperglycemia in metabolic syndrome and diabetes.
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Affiliation(s)
- Motonobu Nakamura
- Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - Hiroyuki Tsukada
- Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - George Seki
- Department of Nephrology, Yaizu City Hospital, Shizuoka, Japan
| | - Nobuhiko Satoh
- Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan; Department of Infection Control and Prevention, The University of Tokyo, Tokyo, Japan
| | - Tomohito Mizuno
- Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - Wataru Fujii
- Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - Shoko Horita
- Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - Kyoji Moriya
- Department of Infection Control and Prevention, The University of Tokyo, Tokyo, Japan
| | - Yusuke Sato
- Department of Urology, The University of Tokyo, Tokyo, Japan
| | - Haruki Kume
- Department of Urology, The University of Tokyo, Tokyo, Japan
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan
| | - Masashi Suzuki
- Health Service Center, Tokyo Gakugei University, Tokyo, Japan.
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ACC/AHA 2017 definition of high blood pressure: implications for women with polycystic ovary syndrome. Fertil Steril 2019; 111:579-587.e1. [DOI: 10.1016/j.fertnstert.2018.11.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 11/21/2018] [Accepted: 11/21/2018] [Indexed: 01/22/2023]
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24
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Gildea JJ, Xu P, Kemp BA, Carlson JM, Tran HT, Bigler Wang D, Langouët-Astrié CJ, McGrath HE, Carey RM, Jose PA, Felder RA. Sodium bicarbonate cotransporter NBCe2 gene variants increase sodium and bicarbonate transport in human renal proximal tubule cells. PLoS One 2018; 13:e0189464. [PMID: 29642240 PMCID: PMC5895442 DOI: 10.1371/journal.pone.0189464] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 11/28/2017] [Indexed: 01/11/2023] Open
Abstract
RATIONALE Salt sensitivity of blood pressure affects >30% of the hypertensive and >15% of the normotensive population. Variants of the electrogenic sodium bicarbonate cotransporter NBCe2 gene, SLC4A5, are associated with increased blood pressure in several ethnic groups. SLC4A5 variants are also highly associated with salt sensitivity, independent of hypertension. However, little is known about how NBCe2 contributes to salt sensitivity, although NBCe2 regulates renal tubular sodium bicarbonate transport. We hypothesized that SLC4A5 rs10177833 and rs7571842 increase NBCe2 expression and human renal proximal tubule cell (hRPTC) sodium transport and may be a cause of salt sensitivity of blood pressure. OBJECTIVE To characterize the hRPTC ion transport of wild-type (WT) and homozygous variants (HV) of SLC4A5. METHODS AND RESULTS The expressions of NBCe2 mRNA and protein were not different between hRPTCs carrying WT or HV SLC4A5 before or after dopaminergic or angiotensin (II and III) stimulation. However, luminal to basolateral sodium transport, NHE3 protein, and Cl-/HCO3- exchanger activity in hRPTCs were higher in HV than WT SLC4A5. Increasing intracellular sodium enhanced the apical location of NBCe2 in HV hRPTCs (4.24±0.35% to 11.06±1.72% (P<0.05, N = 3, 2-way ANOVA, Holm-Sidak test)) as determined by Total Internal Reflection Fluorescence Microscopy (TIRFM). In hRPTCs isolated from kidney tissue, increasing intracellular sodium enhanced bicarbonate-dependent pH recovery rate and increased NBCe2 mRNA and protein expressions to a greater extent in HV than WT SLC4A5 (+38.00±6.23% vs HV normal salt (P<0.01, N = 4, 2-way ANOVA, Holm-Sidak test)). In hRPTCs isolated from freshly voided urine, bicarbonate-dependent pH recovery was also faster in those from salt-sensitive and carriers of HV SLC4A5 than from salt-resistant and carriers of WT SLC4A5. The faster NBCe2-specific bicarbonate-dependent pH recovery rate in HV SCL4A5 was normalized by SLC4A5- but not SLC4A4-shRNA. The binding of purified hepatocyte nuclear factor type 4A (HNF4A) to DNA was increased in hRPTCs carrying HV SLC4A5 rs7571842 but not rs10177833. The faster NBCe2-specific bicarbonate-dependent pH recovery rate in HV SCL4A5 was abolished by HNF4A antagonists. CONCLUSION NBCe2 activity is stimulated by an increase in intracellular sodium and is hyper-responsive in hRPTCs carrying HV SLC4A5 rs7571842 through an aberrant HNF4A-mediated mechanism.
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Affiliation(s)
- John J. Gildea
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | - Peng Xu
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | - Brandon A. Kemp
- The University of Virginia Department of Medicine, Charlottesville, VA, United States of America
| | - Julia M. Carlson
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | - Hanh T. Tran
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | - Dora Bigler Wang
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | | | - Helen E. McGrath
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
| | - Robert M. Carey
- The University of Virginia Department of Medicine, Charlottesville, VA, United States of America
| | - Pedro A. Jose
- The George Washington University School of Medicine & Health Sciences, Department of Medicine, Division of Renal Disease and Hypertension and Department of Pharmacology and Physiology, Washington, DC, United States of America
| | - Robin A. Felder
- The University of Virginia Department of Pathology, Charlottesville, VA, United States of America
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25
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Ferguson TS, Younger-Coleman NOM, Tulloch-Reid MK, Bennett NR, Rousseau AE, Knight-Madden JM, Samms-Vaughan ME, Ashley DE, Wilks RJ. Factors associated with elevated blood pressure or hypertension in Afro-Caribbean youth: a cross-sectional study. PeerJ 2018; 6:e4385. [PMID: 29456896 PMCID: PMC5815333 DOI: 10.7717/peerj.4385] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/29/2018] [Indexed: 12/20/2022] Open
Abstract
Background Although several studies have identified risk factors for high blood pressure (BP), data from Afro-Caribbean populations are limited. Additionally, less is known about how putative risk factors operate in young adults and how social factors influence the risk of high BP. In this study, we estimated the relative risk for elevated BP or hypertension (EBP/HTN), defined as BP ≥ 120/80 mmHg, among young adults with putative cardiovascular disease (CVD) risk factors in Jamaica and evaluated whether relative risks differed by sex. Methods Data from 898 young adults, 18–20 years old, were analysed. BP was measured with a mercury sphygmomanometer after participants had been seated for 5 min. Anthropometric measurements were obtained, and glucose, lipids and insulin measured from a fasting venous blood sample. Data on socioeconomic status (SES) were obtained via questionnaire. CVD risk factor status was defined using standard cut-points or the upper quintile of the distribution where the numbers meeting standard cut-points were small. Relative risks were estimated using odds ratios (OR) from logistic regression models. Results Prevalence of EBP/HTN was 30% among males and 13% among females (p < 0.001 for sex difference). There was evidence for sex interaction in the relationship between EBP/HTN and some of risk factors (obesity and household possessions), therefore we report sex-specific analyses. In multivariable logistic regression models, factors independently associated with EBP/HTN among men were obesity (OR 8.48, 95% CI [2.64–27.2], p < 0.001), and high glucose (OR 2.01, CI [1.20–3.37], p = 0.008), while high HOMA-IR did not achieve statistical significance (OR 2.08, CI [0.94–4.58], p = 0.069). In similar models for women, high triglycerides (OR 1.98, CI [1.03–3.81], p = 0.040) and high HOMA-IR (OR 2.07, CI [1.03–4.12], p = 0.039) were positively associated with EBP/HTN. Lower SES was also associated with higher odds for EBP/HTN (OR 4.63, CI [1.31–16.4], p = 0.017, for moderate vs. high household possessions; OR 2.61, CI [0.70–9.77], p = 0.154 for low vs. high household possessions). Alcohol consumption was associated with lower odds of EBP/HTN among females only; OR 0.41 (CI [0.18–0.90], p = 0.026) for drinking <1 time per week vs. never drinkers, and OR 0.28 (CI [0.11–0.76], p = 0.012) for drinking ≥3 times per week vs. never drinkers. Physical activity was inversely associated with EBP/HTN in both males and females. Conclusion Factors associated with EBP/HTN among Jamaican young adults include obesity, high glucose, high triglycerides and high HOMA-IR, with some significant differences by sex. Among women lower SES was positively associated with EBP/HTN, while moderate alcohol consumption was associated lower odds of EBP/HTN.
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Affiliation(s)
- Trevor S Ferguson
- Caribbean Institute for Health Research, University of the West Indies, Mona, Kingston, Jamaica
| | | | - Marshall K Tulloch-Reid
- Caribbean Institute for Health Research, University of the West Indies, Mona, Kingston, Jamaica
| | - Nadia R Bennett
- Caribbean Institute for Health Research, University of the West Indies, Mona, Kingston, Jamaica
| | - Amanda E Rousseau
- Caribbean Institute for Health Research, University of the West Indies, Mona, Kingston, Jamaica
| | | | | | - Deanna E Ashley
- School of Graduate Studies and Research, University of the West Indies, Mona, Kingston, Jamaica
| | - Rainford J Wilks
- Caribbean Institute for Health Research, University of the West Indies, Mona, Kingston, Jamaica
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Sasaki M, Sasako T, Kubota N, Sakurai Y, Takamoto I, Kubota T, Inagi R, Seki G, Goto M, Ueki K, Nangaku M, Jomori T, Kadowaki T. Dual Regulation of Gluconeogenesis by Insulin and Glucose in the Proximal Tubules of the Kidney. Diabetes 2017. [PMID: 28630133 DOI: 10.2337/db16-1602] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Growing attention has been focused on the roles of the proximal tubules (PTs) of the kidney in glucose metabolism, including the mechanism of regulation of gluconeogenesis. In this study, we found that PT-specific insulin receptor substrate 1/2 double-knockout mice, established by using the newly generated sodium-glucose cotransporter 2 (SGLT2)-Cre transgenic mice, exhibited impaired insulin signaling and upregulated gluconeogenic gene expression and renal gluconeogenesis, resulting in systemic insulin resistance. In contrast, in streptozotocin-treated mice, although insulin action was impaired in the PTs, the gluconeogenic gene expression was unexpectedly downregulated in the renal cortex, which was restored by administration of an SGLT1/2 inhibitor. In the HK-2 cells, the gluconeogenic gene expression was suppressed by insulin, accompanied by phosphorylation and inactivation of forkhead box transcription factor 1 (FoxO1). In contrast, glucose deacetylated peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1α), a coactivator of FoxO1, via sirtuin 1, suppressing the gluconeogenic gene expression, which was reversed by inhibition of glucose reabsorption. These data suggest that both insulin signaling and glucose reabsorption suppress the gluconeogenic gene expression by inactivation of FoxO1 and PGC1α, respectively, providing insight into novel mechanisms underlying the regulation of gluconeogenesis in the PTs.
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Affiliation(s)
- Motohiro Sasaki
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Mie Research Laboratories, Sanwa Kagaku Kenkyusho Co., Ltd., Mie, Japan
| | - Takayoshi Sasako
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Translational Systems Biology and Medicine Initiative, The University of Tokyo, Tokyo, Japan
- Department of Molecular Diabetic Medicine, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Naoto Kubota
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Translational Systems Biology and Medicine Initiative, The University of Tokyo, Tokyo, Japan
- Department of Clinical Nutrition Therapy, The University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan
- Clinical Nutrition Program, National Institute of Health and Nutrition, Tokyo, Japan
- Laboratory for Metabolic Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
| | - Yoshitaka Sakurai
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Iseki Takamoto
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Tetsuya Kubota
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Clinical Nutrition Program, National Institute of Health and Nutrition, Tokyo, Japan
- Laboratory for Metabolic Homeostasis, RIKEN Center for Integrative Medical Sciences, Kanagawa, Japan
- Division of Cardiovascular Medicine, Toho University Ohashi Medical Center, Tokyo, Japan
| | - Reiko Inagi
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | | | - Moritaka Goto
- Mie Research Laboratories, Sanwa Kagaku Kenkyusho Co., Ltd., Mie, Japan
| | - Kohjiro Ueki
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Translational Systems Biology and Medicine Initiative, The University of Tokyo, Tokyo, Japan
- Department of Molecular Diabetic Medicine, Diabetes Research Center, National Center for Global Health and Medicine, Tokyo, Japan
| | - Masaomi Nangaku
- Department of Nephrology and Endocrinology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takahito Jomori
- Mie Research Laboratories, Sanwa Kagaku Kenkyusho Co., Ltd., Mie, Japan
| | - Takashi Kadowaki
- Department of Diabetes and Metabolic Diseases, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
- Translational Systems Biology and Medicine Initiative, The University of Tokyo, Tokyo, Japan
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Sodium restriction modulates innate immunity and prevents cardiac remodeling in a rat model of metabolic syndrome. Biochim Biophys Acta Mol Basis Dis 2017; 1863:1568-1574. [DOI: 10.1016/j.bbadis.2017.02.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/16/2017] [Accepted: 02/24/2017] [Indexed: 12/19/2022]
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Matsumoto T, Kobayashi S, Ando M, Watanabe S, Iguchi M, Taguchi K, Kobayashi T. Impaired endothelium-derived hyperpolarization-type relaxation in superior mesenteric arteries isolated from female Otsuka Long-Evans Tokushima Fatty rats. Eur J Pharmacol 2017; 807:151-158. [PMID: 28433656 DOI: 10.1016/j.ejphar.2017.03.062] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 02/27/2017] [Accepted: 03/31/2017] [Indexed: 01/27/2023]
Abstract
Endothelium-derived hyperpolarization (EDH) is an important signaling mechanism of endothelium-dependent vasorelaxation, and little attention has been paid to the EDH-type responses in female metabolic syndrome such as that observed with type-2 diabetes. We previously reported that EDH-type relaxation was impaired in superior mesenteric arteries from male Otsuka Long-Evans Tokushima Fatty (OLETF) rat, a model of type-2 diabetes, however, the response was unclear in female OLETF rat. Thus, the aim of this study was to examine if EDH-type relaxation was altered in superior mesenteric arteries isolated from female OLETF rats compared to age-matched, control female Long-Evans Tokushima Otsuka (LETO) rats at age 50-59 weeks. We investigated concentration-relaxation curves for acetylcholine (at age 50-53 weeks), NS309 (an activator of small- and intermediate-conductance calcium-activated potassium channels) (at age 50-53 weeks), and GSK1016790A (an agonist of transient receptor potential vanilloid type 4, TRPV4) (at age 58 or 59 weeks) in the presence of the nitric oxide synthase inhibitor NG-nitro-L-arginine and the cyclooxygenase inhibitor indomethacin to investigate EDH-type responses in the superior mesenteric artery. Obesity, mild hyperglycemia, hyperinsulinemia, and hyperlipidemia (i.e., increased total cholesterol, triglyceride, and non-esterified fatty acids) were more frequent in OLETF rats than in age-matched LETO rats at age 50-53 weeks. Acetylcholine-, NS309-, and GSK1016790A-induced relaxations in arteries from OLETF rats were all significantly reduced compared to those in LETO rats. These results indicated that EDH-type relaxations were impaired in female OLETF rats. This novel experimental model may provide new insights into vascular dysfunction in metabolic syndrome in females.
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Affiliation(s)
- Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Shota Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Makoto Ando
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Shun Watanabe
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Maika Iguchi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Kumiko Taguchi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Tsuneo Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo 142-8501, Japan.
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Horita S, Nakamura M, Suzuki M, Satoh N, Suzuki A, Homma Y, Nangaku M. The role of renal proximal tubule transport in the regulation of blood pressure. Kidney Res Clin Pract 2017; 36:12-21. [PMID: 28428931 PMCID: PMC5331971 DOI: 10.23876/j.krcp.2017.36.1.12] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Revised: 10/18/2016] [Accepted: 12/05/2016] [Indexed: 12/15/2022] Open
Abstract
The electrogenic sodium/bicarbonate cotransporter 1 (NBCe1) on the basolateral side of the renal proximal tubule plays a pivotal role in systemic acid-base homeostasis. Mutations in the gene encoding NBCe1 cause severe proximal renal tubular acidosis accompanied by other extrarenal symptoms. The proximal tubule reabsorbs most of the sodium filtered in the glomerulus, contributing to the regulation of plasma volume and blood pressure. NBCe1 and other sodium transporters in the proximal tubule are regulated by hormones, such as angiotensin II and insulin. Angiotensin II is probably the most important stimulator of sodium reabsorption. Proximal tubule AT1A receptor is crucial for the systemic pressor effect of angiotensin II. In rodents and rabbits, the effect on proximal tubule NBCe1 is biphasic; at low concentration, angiotensin II stimulates NBCe1 via PKC/cAMP/ERK, whereas at high concentration, it inhibits NBCe1 via NO/cGMP/cGKII. In contrast, in human proximal tubule, angiotensin II has a dose-dependent monophasic stimulatory effect via NO/cGMP/ERK. Insulin stimulates the proximal tubule sodium transport, which is IRS2-dependent. We found that in insulin resistance and overt diabetic nephropathy, stimulatory effect of insulin on proximal tubule transport was preserved. Our results suggest that the preserved stimulation of the proximal tubule enhances sodium reabsorption, contributing to the pathogenesis of hypertension with metabolic syndrome. We describe recent findings regarding the role of proximal tubule transport in the regulation of blood pressure, focusing on the effects of angiotensin II and insulin.
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Affiliation(s)
- Shoko Horita
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Motonobu Nakamura
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Masashi Suzuki
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Nobuhiko Satoh
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Atsushi Suzuki
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Yukio Homma
- Department of Urology, The University of Tokyo Hospital, Tokyo, Japan
| | - Masaomi Nangaku
- Department of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
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30
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Affiliation(s)
- Jian Yang
- Department of Nutrition, Daping Hospital, The Third Military Medical University, Chongqing, China.,Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
| | - Pedro A Jose
- Division of Renal Disease & Hypertension, The George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Chunyu Zeng
- Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing, China
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31
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Fizelova M, Jauhiainen R, Stančáková A, Kuusisto J, Laakso M. Finnish Diabetes Risk Score Is Associated with Impaired Insulin Secretion and Insulin Sensitivity, Drug-Treated Hypertension and Cardiovascular Disease: A Follow-Up Study of the METSIM Cohort. PLoS One 2016; 11:e0166584. [PMID: 27851812 PMCID: PMC5112858 DOI: 10.1371/journal.pone.0166584] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/31/2016] [Indexed: 12/25/2022] Open
Abstract
We investigated the association of the Finnish Diabetes Risk Score (FINDRISC) with insulin secretion, insulin sensitivity, and risk of type 2 diabetes, drug-treated hypertension, cardiovascular (CVD) events and total mortality in a follow-up study of the Metabolic Syndrome in Men (METSIM) cohort. The METSIM study includes 10,197 Finnish men, aged 45-73 years, and examined in 2005-2010. Of 8,749 non-diabetic participants of the METSIM study 693 developed incident type 2 diabetes, 225 started antihypertensive medication, 351 had a CVD event, and 392 died during a 8.2-year follow-up. The FINDRISC was significantly associated with decreases in insulin secretion and insulin sensitivity (P<0.0001), and with a 4.14-fold increased risk of incident type 2 diabetes, 2.43-fold increased risk of drug-treated hypertension, 1.61-fold increased risk of CVD, and 1.55-increased risk of total mortality (the FINDRISC ≥12 vs. < 12 points). In conclusion, the FINDRISC predicts impairment in insulin secretion and insulin sensitivity, the conversion to type 2 diabetes, drug-treated hypertension, CVD events and total mortality.
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Affiliation(s)
- Maria Fizelova
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland
| | - Raimo Jauhiainen
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Alena Stančáková
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland, Kuopio, Finland
| | - Johanna Kuusisto
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Markku Laakso
- Institute of Clinical Medicine, Internal Medicine, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
- * E-mail:
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Abstract
Insulin resistance is a systemic disorder that affects many organs and insulin-regulated pathways. The disorder is characterized by a reduced action of insulin despite increased insulin concentrations (hyperinsulinaemia). The effects of insulin on the kidney and vasculature differ in part from the effects on classical insulin target organs. Insulin causes vasodilation by enhancing endothelial nitric oxide production through activation of the phosphatidylinositol 3-kinase pathway. In insulin-resistant states, this pathway is impaired and the mitogen-activated protein kinase pathway stimulates vasoconstriction. The action of insulin on perivascular fat tissue and the subsequent effects on the vascular wall are not fully understood, but the hepatokine fetuin-A, which is released by fatty liver, might promote the proinflammatory effects of perivascular fat. The strong association of salt-sensitive arterial hypertension with insulin resistance indicates an involvement of the kidney in the insulin resistance syndrome. The insulin receptor is expressed on renal tubular cells and podocytes and insulin signalling has important roles in podocyte viability and tubular function. Renal sodium transport is preserved in insulin resistance and contributes to the salt-sensitivity of blood pressure in hyperinsulinaemia. Therapeutically, renal and vascular insulin resistance can be improved by an integrated holistic approach aimed at restoring overall insulin sensitivity and improving insulin signalling.
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Selective Insulin Resistance in the Kidney. BIOMED RESEARCH INTERNATIONAL 2016; 2016:5825170. [PMID: 27247938 PMCID: PMC4876201 DOI: 10.1155/2016/5825170] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/04/2016] [Accepted: 04/07/2016] [Indexed: 12/12/2022]
Abstract
Insulin resistance has been characterized as attenuation of insulin sensitivity at target organs and tissues, such as muscle and fat tissues and the liver. The insulin signaling cascade is divided into major pathways such as the PI3K/Akt pathway and the MAPK/MEK pathway. In insulin resistance, however, these pathways are not equally impaired. For example, in the liver, inhibition of gluconeogenesis by the insulin receptor substrate (IRS) 2 pathway is impaired, while lipogenesis by the IRS1 pathway is preserved, thus causing hyperglycemia and hyperlipidemia. It has been recently suggested that selective impairment of insulin signaling cascades in insulin resistance also occurs in the kidney. In the renal proximal tubule, insulin signaling via IRS1 is inhibited, while insulin signaling via IRS2 is preserved. Insulin signaling via IRS2 continues to stimulate sodium reabsorption in the proximal tubule and causes sodium retention, edema, and hypertension. IRS1 signaling deficiency in the proximal tubule may impair IRS1-mediated inhibition of gluconeogenesis, which could induce hyperglycemia by preserving glucose production. In the glomerulus, the impairment of IRS1 signaling deteriorates the structure and function of podocyte and endothelial cells, possibly causing diabetic nephropathy. This paper mainly describes selective insulin resistance in the kidney, focusing on the proximal tubule.
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Satoh N, Yamada H, Yamazaki O, Suzuki M, Nakamura M, Suzuki A, Ashida A, Yamamoto D, Kaku Y, Sekine T, Seki G, Horita S. A pure chloride channel mutant of CLC-5 causes Dent's disease via insufficient V-ATPase activation. Pflugers Arch 2016; 468:1183-1196. [PMID: 27044412 DOI: 10.1007/s00424-016-1808-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 02/02/2016] [Accepted: 03/08/2016] [Indexed: 01/22/2023]
Abstract
Dent's disease is characterized by defective endocytosis in renal proximal tubules (PTs) and caused by mutations in the 2Cl(-)/H(+) exchanger, CLC-5. However, the pathological role of endosomal acidification in endocytosis has recently come into question. To clarify the mechanism of pathogenesis for Dent's disease, we examined the effects of a novel gating glutamate mutation, E211Q, on CLC-5 functions and endosomal acidification. In Xenopus oocytes, wild-type (WT) CLC-5 showed outward-rectifying currents that were inhibited by extracellular acidosis, but E211Q and an artificial pure Cl(-) channel mutant, E211A, showed linear currents that were insensitive to extracellular acidosis. Moreover, depolarizing pulse trains induced a robust reduction in the surface pH of oocytes expressing WT CLC-5 but not E211Q or E211A, indicating that the E211Q mutant functions as a pure Cl(-) channel similar to E211A. In HEK293 cells, E211A and E211Q stimulated endosomal acidification and hypotonicity-inducible vacuolar-type H(+)-ATPase (V-ATPase) activation at the plasma membrane. However, the stimulatory effects of these mutants were reduced compared with WT CLC-5. Furthermore, gene silencing experiments confirmed the functional coupling between V-ATPase and CLC-5 at the plasma membrane of isolated mouse PTs. These results reveal for the first time that the conversion of CLC-5 from a 2Cl(-)/H(+) exchanger into a Cl(-) channel induces Dent's disease in humans. In addition, defective endosomal acidification as a result of insufficient V-ATPase activation may still be important in the pathogenesis of Dent's disease.
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Affiliation(s)
- Nobuhiko Satoh
- Department of Internal Medicine, Faculty of Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Hideomi Yamada
- Department of Internal Medicine, Faculty of Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Osamu Yamazaki
- Apheresis and Dialysis Center, General Medicine, School of Medicine, Keio University, Tokyo, Japan
| | - Masashi Suzuki
- Department of Internal Medicine, Faculty of Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Motonobu Nakamura
- Department of Internal Medicine, Faculty of Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Atsushi Suzuki
- Department of Internal Medicine, Faculty of Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Akira Ashida
- Department of Pediatrics, Osaka Medical College, Takatsuki, Osaka, Japan
| | - Daisuke Yamamoto
- Biomedical Computation Center, Osaka Medical College, Takatsuki, Osaka, Japan
| | - Yoshitsugu Kaku
- Department of Nephrology, Fukuoka Children's Hospital, Fukuoka, Japan
| | - Takashi Sekine
- Department of Pediatrics, Ohashi Medical Center, Toho University, Meguro-ku, Tokyo, Japan
| | | | - Shoko Horita
- Department of Internal Medicine, Faculty of Medicine, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
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Abstract
Insulin resistance is associated with hypertension. Nakamura et al. demonstrate in rodents and humans with insulin resistance that while the stimulatory effect of insulin on glucose uptake in adipocytes, mediated via insulin receptor substrate 1 (IRS1), was severely diminished, its effect on salt reabsorption in the kidney proximal tubule, mediated via IRS2, was preserved. Compensatory hyperinsulinemia in individuals with insulin resistance may enhance salt absorption in the proximal tubule, resulting in a state of salt overload and hypertension.
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Coffey S, Costacou T, Orchard T, Erkan E. Akt Links Insulin Signaling to Albumin Endocytosis in Proximal Tubule Epithelial Cells. PLoS One 2015; 10:e0140417. [PMID: 26465605 PMCID: PMC4605734 DOI: 10.1371/journal.pone.0140417] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 09/26/2015] [Indexed: 12/20/2022] Open
Abstract
Diabetes mellitus (DM) has become an epidemic, causing a significant decline in quality of life of individuals due to its multisystem involvement. Kidney is an important target organ in DM accounting for the majority of patients requiring renal replacement therapy at dialysis units. Microalbuminuria (MA) has been a valuable tool to predict end-organ damage in DM but its low sensitivity has driven research efforts to seek other alternatives. Albumin is taken up by albumin receptors, megalin and cubilin in the proximal tubule epithelial cells. We demonstrated that insulin at physiological concentrations induce albumin endocytosis through activation of protein kinase B (Akt) in proximal tubule epithelial cells. Inhibition of Akt by a phosphorylation deficient construct abrogated insulin induced albumin endocytosis suggesting a role for Akt in insulin-induced albumin endocytosis. Furthermore we demonstrated a novel interaction between Akt substrate 160kDa (AS160) and cytoplasmic tail of megalin. Mice with type 1 DM (T1D) displayed decreased Akt, megalin, cubilin and AS160 expression in their kidneys in association with urinary cubilin shedding preceding significant MA. Patients with T1D who have developed MA in the EDC (The Pittsburgh Epidemiology of Diabetes Complications) study demonstrated urinary cubilin shedding prior to development of MA. We hypothesize that perturbed insulin-Akt cascade in DM leads to alterations in trafficking of megalin and cubilin, which results in urinary cubilin shedding as a prelude to MA in early diabetic nephropathy. We propose that utilization of urinary cubilin shedding, as a urinary biomarker, will allow us to detect and intervene in diabetic nephropathy (DN) at an earlier stage.
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Affiliation(s)
- Sam Coffey
- Cincinnati Children’s Hospital Medical Center, Division of Nephrology, Cincinnati, OH, United States of America
| | - Tina Costacou
- University of Pittsburgh, Department of Epidemiology, Pittsburgh, United States of America
| | - Trevor Orchard
- University of Pittsburgh, Department of Epidemiology, Pittsburgh, United States of America
| | - Elif Erkan
- Cincinnati Children’s Hospital Medical Center, Division of Nephrology, Cincinnati, OH, United States of America
- * E-mail:
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Roles of Akt and SGK1 in the Regulation of Renal Tubular Transport. BIOMED RESEARCH INTERNATIONAL 2015; 2015:971697. [PMID: 26491696 PMCID: PMC4600925 DOI: 10.1155/2015/971697] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 09/06/2015] [Indexed: 01/31/2023]
Abstract
A serine/threonine kinase Akt is a key mediator in various signaling pathways including regulation of renal tubular transport. In proximal tubules, Akt mediates insulin signaling via insulin receptor substrate 2 (IRS2) and stimulates sodium-bicarbonate cotransporter (NBCe1), resulting in increased sodium reabsorption. In insulin resistance, the IRS2 in kidney cortex is exceptionally preserved and may mediate the stimulatory effect of insulin on NBCe1 to cause hypertension in diabetes via sodium retention. Likewise, in distal convoluted tubules and cortical collecting ducts, insulin-induced Akt phosphorylation mediates several hormonal signals to enhance sodium-chloride cotransporter (NCC) and epithelial sodium channel (ENaC) activities, resulting in increased sodium reabsorption. Serum- and glucocorticoid-inducible kinase 1 (SGK1) mediates aldosterone signaling. Insulin can stimulate SGK1 to exert various effects on renal transporters. In renal cortical collecting ducts, SGK1 regulates the expression level of ENaC through inhibition of its degradation. In addition, SGK1 and Akt cooperatively regulate potassium secretion by renal outer medullary potassium channel (ROMK). Moreover, sodium-proton exchanger 3 (NHE3) in proximal tubules is possibly activated by SGK1. This review focuses on recent advances in understanding of the roles of Akt and SGK1 in the regulation of renal tubular transport.
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Zhang X, Li ZL, Eirin A, Ebrahimi B, Pawar AS, Zhu XY, Lerman A, Lerman LO. Cardiac metabolic alterations in hypertensive obese pigs. Hypertension 2015; 66:430-6. [PMID: 26077566 DOI: 10.1161/hypertensionaha.115.05478] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 05/21/2015] [Indexed: 01/15/2023]
Abstract
Obesity and hypertension are major risk factors for cardiovascular diseases, and their growing coexistence accounts for an increase in adverse cardiac events, but the mechanisms are yet to be determined. We hypothesized that obesity exacerbates mitochondrial dysregulation imposed by hypertension and augments left ventricular dysfunction. Obesity-prone Ossabaw pigs were randomized to lean (standard diet) and obese (high-fat diet), without (Lean-sham and Obese-sham) or with renovascular hypertension (Lean-hypertension and Obese-hypertension), induced after 12 weeks of diet (n=7 each). Cardiac function, myocardial perfusion and oxygenation, and microvascular remodeling were assessed 4 weeks later. Mitochondrial biogenesis signals and structural proteins, respiratory chain complex activities, and mitochondrial self-degradation were examined, as was fibrosis. Obesity alone exerted no apparent effect on mitochondrial dynamics, but aggravated in hypertensive hearts the reduction of mitochondrial proteins, deoxyribonucleic acid content, and respiratory chain complex IV subunits activity, and amplified mitochondrial self-degradation. Synergistic interaction of obesity with hypertension also exacerbated myocardial fibrosis and left ventricular diastolic dysfunction. Mitochondrial content, respiratory chain complex IV subunits activity, and mitophagy were correlated with myocardial fibrosis. These findings suggest that obesity aggravates in renovascular hypertension cardiac mitochondrial aberrations. Mitochondrial function may regulate the progression of cardiac injury and functional deterioration in hypertension concomitant with obesity.
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Affiliation(s)
- Xin Zhang
- From the Divisions of Nephrology and Hypertension (X.Z., Z.-L.L., A.E., B.E., A.S.P., X.-Y.Z., L.O.L.) and Cardiovascular Diseases (A.L., L.O.L.), Mayo Clinic, Rochester, MN; and Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (Z.-L.L.)
| | - Zi-Lun Li
- From the Divisions of Nephrology and Hypertension (X.Z., Z.-L.L., A.E., B.E., A.S.P., X.-Y.Z., L.O.L.) and Cardiovascular Diseases (A.L., L.O.L.), Mayo Clinic, Rochester, MN; and Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (Z.-L.L.)
| | - Alfonso Eirin
- From the Divisions of Nephrology and Hypertension (X.Z., Z.-L.L., A.E., B.E., A.S.P., X.-Y.Z., L.O.L.) and Cardiovascular Diseases (A.L., L.O.L.), Mayo Clinic, Rochester, MN; and Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (Z.-L.L.)
| | - Behzad Ebrahimi
- From the Divisions of Nephrology and Hypertension (X.Z., Z.-L.L., A.E., B.E., A.S.P., X.-Y.Z., L.O.L.) and Cardiovascular Diseases (A.L., L.O.L.), Mayo Clinic, Rochester, MN; and Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (Z.-L.L.)
| | - Aditya S Pawar
- From the Divisions of Nephrology and Hypertension (X.Z., Z.-L.L., A.E., B.E., A.S.P., X.-Y.Z., L.O.L.) and Cardiovascular Diseases (A.L., L.O.L.), Mayo Clinic, Rochester, MN; and Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (Z.-L.L.)
| | - Xiang-Yang Zhu
- From the Divisions of Nephrology and Hypertension (X.Z., Z.-L.L., A.E., B.E., A.S.P., X.-Y.Z., L.O.L.) and Cardiovascular Diseases (A.L., L.O.L.), Mayo Clinic, Rochester, MN; and Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (Z.-L.L.)
| | - Amir Lerman
- From the Divisions of Nephrology and Hypertension (X.Z., Z.-L.L., A.E., B.E., A.S.P., X.-Y.Z., L.O.L.) and Cardiovascular Diseases (A.L., L.O.L.), Mayo Clinic, Rochester, MN; and Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (Z.-L.L.)
| | - Lilach O Lerman
- From the Divisions of Nephrology and Hypertension (X.Z., Z.-L.L., A.E., B.E., A.S.P., X.-Y.Z., L.O.L.) and Cardiovascular Diseases (A.L., L.O.L.), Mayo Clinic, Rochester, MN; and Division of Vascular Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China (Z.-L.L.).
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Seki G, Nakamura M, Suzuki M, Satoh N, Horita S. Species differences in regulation of renal proximal tubule transport by certain molecules. World J Nephrol 2015; 4:307-312. [PMID: 25949945 PMCID: PMC4419141 DOI: 10.5527/wjn.v4.i2.307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 12/24/2014] [Accepted: 01/20/2015] [Indexed: 02/06/2023] Open
Abstract
Renal proximal tubules (PTs) play important roles in the regulation of acid/base, plasma volume and blood pressure. Recent studies suggest that there are substantial species differences in the regulation of PT transport. For example, thiazolidinediones (TZDs) are widely used for the treatment of type 2 diabetes mellitus, but the use of TZDs is associated with fluid overload. In addition to the transcriptional enhancement of sodium transport in distal nephrons, TZDs rapidly stimulate PT sodium transport via a non-genomic mechanism depending on peroxisome proliferator activated receptor γ/Src/epidermal growth factor receptor (EGFR)/MEK/ERK. In mouse PTs, however, TZDs fail to stimulate PT transport probably due to constitutive activation of Src/EGFR/ERK pathway. This unique activation of Src/ERK may also affect the effect of high concentrations of insulin on mouse PT transport. On the other hand, the effect of angiotensin II (Ang II) on PT transport is known to be biphasic in rabbits, rats, and mice. However, Ang II induces a concentration-dependent, monophasic transport stimulation in human PTs. The contrasting responses to nitric oxide/guanosine 3’,5’-cyclic monophosphate pathway may largely explain these different effects of Ang II on PT transport. In this review, we focus on the recent findings on the species differences in the regulation of PT transport, which may help understand the species-specific mechanisms underlying edema formation and/or hypertension occurrence.
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Yee J. Hypertension in CKD: Sodium still at the nexus. Adv Chronic Kidney Dis 2015; 22:173-6. [PMID: 25908464 DOI: 10.1053/j.ackd.2015.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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41
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Nakamura M, Satoh N, Suzuki M, Kume H, Homma Y, Seki G, Horita S. Stimulatory effect of insulin on renal proximal tubule sodium transport is preserved in type 2 diabetes with nephropathy. Biochem Biophys Res Commun 2015; 461:154-8. [DOI: 10.1016/j.bbrc.2015.04.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 04/01/2015] [Indexed: 11/16/2022]
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