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Hao M, Lv Y, Liu S, Guo W. The New Challenge of Obesity - Obesity-Associated Nephropathy. Diabetes Metab Syndr Obes 2024; 17:1957-1971. [PMID: 38737387 PMCID: PMC11086398 DOI: 10.2147/dmso.s433649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 02/28/2024] [Indexed: 05/14/2024] Open
Abstract
In recent years, obesity has become one of the major diseases that affect human health and consume human health resources, especially when it causes comorbidities such as hypertension, diabetes, cardiovascular disease and kidney disease. Many studies have demonstrated that obesity is associated with the development of chronic kidney disease and can exacerbate the progression of end-stage renal disease. This review described the mechanisms associated with the development of obesity-associated nephropathy and the current relevant therapeutic modalities, with the aim of finding new therapeutic targets for obesity-associated nephropathy. The mechanisms of obesity-induced renal injury include, in addition to the traditional alterations in renal hemodynamics, the involvement of various mechanisms such as macrophage infiltration in adipose tissue, alterations in adipokines (leptin and adiponectin), and ectopic deposition of lipids. At present, there is no "point-to-point" treatment for obesity-induced kidney injury. The renin-angiotensin-aldosterone system (RAAS) inhibitors, sodium-dependent glucose transporter 2 (SGLT-2) inhibitors and bariatric surgery described in this review can reduce urinary protein to varying degrees and delay the progression of kidney disease. In addition, recent studies on the therapeutic effects of intestinal flora on obesity may reduce the incidence of obesity-related kidney disease from the perspective of primary prevention. Both of these interventions have their own advantages and disadvantages, so the continuous search for the mechanism of obesity-induced related kidney disease will be extremely helpful for the future treatment of obesity-related kidney disease.
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Affiliation(s)
- Mengjin Hao
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, 130021, People’s Republic of China
- Department of Endocrinology, Jining No. 1 People’s Hospital, Jining, Shandong, 272000, People’s Republic of China
| | - You Lv
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, 130021, People’s Republic of China
| | - Siyuan Liu
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, 130021, People’s Republic of China
| | - Weiying Guo
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, Jilin, 130021, People’s Republic of China
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Reese-Petersen AL, Holm Nielsen S, Bülow Sand JM, Schattenberg JM, Bugianesi E, Karsdal MA. The sclerotic component of metabolic syndrome: Fibroblast activities may be the central common denominator driving organ function loss and death. Diabetes Obes Metab 2024. [PMID: 38699780 DOI: 10.1111/dom.15615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/09/2024] [Accepted: 04/09/2024] [Indexed: 05/05/2024]
Abstract
Fibrosis is a common feature of more than 50 different diseases and the cause of more than 35% of deaths worldwide, of which liver, kidney, skin, heart and, recently, lungs are receiving the most attention. Tissue changes, resulting in loss of organ function, are both a cause and consequence of disease and outcome. Fibrosis is caused by an excess deposition of extracellular matrix proteins, which over time results in impaired organ function and organ failure, and the pathways leading to increased fibroblast activation are many. This narrative review investigated the common denominator of fibrosis, fibroblasts, and the activation of fibroblasts, in response to excess energy consumption in liver, kidney, heart, skin and lung fibrosis. Fibroblasts are the main drivers of organ function loss in lung, liver, skin, heart and kidney disease. Fibroblast activation in response to excess energy consumption results in the overproduction of a range of collagens, of which types I, III and VI seem to be the essential drivers of disease progression. Fibroblast activation may be quantified in serum, enabling profiling and selection of patients. Activation of fibroblasts results in the overproduction of collagens, which deteriorates organ function. Patient profiling of fibroblast activities in serum, quantified as collagen production, may identify an organ death trajectory, better enabling identification of the right treatment for use in different metabolic interventions. As metabolically activated patients have highly elevated risk of kidney, liver and heart failure, it is essential to identify which organ to treat first and monitor organ status to correct treatment regimes. In direct alignment with this, it is essential to identify the right patients with the right organ deterioration trajectory for enrolment in clinical studies.
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Affiliation(s)
| | | | | | - Jörn M Schattenberg
- Saarland University Medical Center, Homburg, Germany
- University of the Saarland, Saarbrücken, Germany
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Park HS, Park SH, Seong Y, Kim HJ, Choi HY, Rhee Y, Park HC, Jhee JH. Adiponectin-to-leptin ratio and incident chronic kidney disease: Sex and body composition-dependent association. J Cachexia Sarcopenia Muscle 2024. [PMID: 38632706 DOI: 10.1002/jcsm.13475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 02/14/2024] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
BACKGROUND The association between the adiponectin-to-leptin ratio (A/L ratio) and the risk of incident chronic kidney disease (CKD) is poorly understood. This study aimed to investigate the association between A/L ratio and the risk of incident CKD and to examine whether such a relationship varied according to sex and body composition. METHODS In this prospective community-based cohort, participants with normal kidney function were analysed (N = 5192). The association between the A/L ratio at baseline and the risk of incident CKD, defined as two or more occasions with an estimated glomerular filtration rate of <60 mL/min/m2 or proteinuria of ≥1+ on a dipstick test during the follow-up period, was evaluated using multivariable Cox proportional hazards analyses. Subgroup analyses were conducted based on sex, body mass index (BMI) and the presence of sarcopenia. RESULTS The participants' mean age was 57.2 ± 8.3 years, and 53.2% were women. The A/L ratio was higher in men compared with women (1.5 [0.8-3.2] and 0.5 [0.3-0.9] μg/ng, P < 0.001). During a median follow-up of 9.8 [9.5-10.0] years, 417 incident CKD events occurred (8.7 per 1000 person-years). Men in the highest quartile of A/L ratio had a lower risk of incident CKD (adjusted hazard ratio [aHR], 0.57; 95% confidence interval [CI], 0.33-0.99) than those in the lowest quartile. Additionally, a 1.0 increase in A/L ratio was associated with a 12% decreased risk of incident CKD in men (aHR, 0.88; 95% CI, 0.80-0.97). However, no significant association was observed in women. In subgroup analysis stratified by BMI and the presence of sarcopenia, the association between a high A/L ratio and a reduced risk of incident CKD was consistent in men with a BMI < 23.0 kg/m2 and those with sarcopenia. However, no significant association was observed between men with a BMI ≥ 23.0 kg/m2 and those without sarcopenia. CONCLUSIONS A high A/L ratio is an independent marker of a reduced risk of incident CKD in men, especially in those with a BMI < 23.0 kg/m2 and sarcopenia.
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Affiliation(s)
- Hye-Sun Park
- Division of Endocrinology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Sang Ho Park
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Yeseul Seong
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hyo Jeong Kim
- Division of Nephrology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hoon Young Choi
- Division of Nephrology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Yumie Rhee
- Department of Internal Medicine, Endocrine Research Institute, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hyeong Cheon Park
- Division of Nephrology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jong Hyun Jhee
- Division of Nephrology, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
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Kalusche W, Case C, Taylor E. Leptin antagonism attenuates hypertension and renal injury in an experimental model of autoimmune disease. Clin Sci (Lond) 2023; 137:1771-1785. [PMID: 38031726 PMCID: PMC10721433 DOI: 10.1042/cs20230924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 11/25/2023] [Accepted: 11/29/2023] [Indexed: 12/01/2023]
Abstract
Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder that is characterized by B- and T-lymphocyte dysfunction and altered cytokine production, including elevated levels of the adipocytokine leptin. Leptin has various immunomodulatory properties, including promoting the expansion of proinflammatory T lymphocytes and the proliferation and survival of B cells. In the present study, we hypothesized that leptin antagonism would improve B- and T-cell dysfunction and attenuate hypertension in an experimental model of SLE, the NZBWF1 mouse. To test this hypothesis, 28-week-old female control and SLE mice were administered 5 mg/kg of murine leptin superantagonist (LA) or vehicle via ip injection every other day for four weeks. Analysis of peripheral blood immune cell populations showed no changes in total CD45R+ B and CD3+ T cell percentages after treatment with LA. However, SLE mice treated with LA had an improved CD4/CD8 ratio and decreased CD3+CD4-CD8- double negative (DN) T cells. Blood pressure was higher in SLE than in control, and treatment with LA decreased blood pressure in SLE mice. Treatment with LA also delayed the onset of albuminuria and decreased glomerulosclerosis in SLE mice. Renal immune cell infiltration was significantly higher in SLE mice as compared with control, but LA treatment was associated with decreased levels of renal CD4+ T cells. In conclusion, these data suggest that leptin plays a pathogenic role in the development of hypertension in SLE, in part, by promoting the expansion of inflammatory DN T cells and the infiltration of T cells into the kidneys.
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Affiliation(s)
- William J. Kalusche
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, U.S.A
| | - Clinton T. Case
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, U.S.A
| | - Erin B. Taylor
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS 39216, U.S.A
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Packer M. Fetal Reprogramming of Nutrient Surplus Signaling, O-GlcNAcylation, and the Evolution of CKD. J Am Soc Nephrol 2023; 34:1480-1491. [PMID: 37340541 PMCID: PMC10482065 DOI: 10.1681/asn.0000000000000177] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 06/07/2023] [Indexed: 06/22/2023] Open
Abstract
ABSTRACT Fetal kidney development is characterized by increased uptake of glucose, ATP production by glycolysis, and upregulation of mammalian target of rapamycin (mTOR) and hypoxia-inducible factor-1 alpha (HIF-1 α ), which (acting in concert) promote nephrogenesis in a hypoxic low-tubular-workload environment. By contrast, the healthy adult kidney is characterized by upregulation of sirtuin-1 and adenosine monophosphate-activated protein kinase, which enhances ATP production through fatty acid oxidation to fulfill the needs of a normoxic high-tubular-workload environment. During stress or injury, the kidney reverts to a fetal signaling program, which is adaptive in the short term, but is deleterious if sustained for prolonged periods when both oxygen tension and tubular workload are heightened. Prolonged increases in glucose uptake in glomerular and proximal tubular cells lead to enhanced flux through the hexosamine biosynthesis pathway; its end product-uridine diphosphate N -acetylglucosamine-drives the rapid and reversible O-GlcNAcylation of thousands of intracellular proteins, typically those that are not membrane-bound or secreted. Both O-GlcNAcylation and phosphorylation act at serine/threonine residues, but whereas phosphorylation is regulated by hundreds of specific kinases and phosphatases, O-GlcNAcylation is regulated only by O-GlcNAc transferase and O-GlcNAcase, which adds or removes N-acetylglucosamine, respectively, from target proteins. Diabetic and nondiabetic CKD is characterized by fetal reprogramming (with upregulation of mTOR and HIF-1 α ) and increased O-GlcNAcylation, both experimentally and clinically. Augmentation of O-GlcNAcylation in the adult kidney enhances oxidative stress, cell cycle entry, apoptosis, and activation of proinflammatory and profibrotic pathways, and it inhibits megalin-mediated albumin endocytosis in glomerular mesangial and proximal tubular cells-effects that can be aggravated and attenuated by augmentation and muting of O-GlcNAcylation, respectively. In addition, drugs with known nephroprotective effects-angiotensin receptor blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter 2 inhibitors-are accompanied by diminished O-GlcNAcylation in the kidney, although the role of such suppression in mediating their benefits has not been explored. The available evidence supports further work on the role of uridine diphosphate N -acetylglucosamine as a critical nutrient surplus sensor (acting in concert with upregulated mTOR and HIF-1 α signaling) in the development of diabetic and nondiabetic CKD.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute , Dallas , Texas and Imperial College , London , United Kingdom
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Kadatane SP, Satariano M, Massey M, Mongan K, Raina R. The Role of Inflammation in CKD. Cells 2023; 12:1581. [PMID: 37371050 DOI: 10.3390/cells12121581] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/02/2023] [Accepted: 06/03/2023] [Indexed: 06/29/2023] Open
Abstract
Chronic kidney disease (CKD) affects many adults worldwide. Persistent low-grade inflammation is a substantial factor in its development and progression and has correlated with increased mortality and cardiovascular problems. This low-grade inflammation is a product of dysregulation of the normal balance between pro- and anti-inflammatory markers. Various factors such as increased innate immune system activation, reactive oxygen species production, periodontal disease, dysregulation of anti-inflammatory systems and intestinal dysbiosis result in the dysregulation of this balance. Furthermore, this low-grade inflammation has down-effects such as hypertension, renal fibrosis and acceleration of renal function decline. Moreover, low-grade inflammation over time has been linked to malignancy in CKD. As CKD progresses, many patients require dialysis, which has a negative bidirectional relationship with persistent inflammation. Treatment options for inflammation in CKD are vast, including cytokine inhibitors, statins and diets. However, more research is needed to create a standardized management plan. In this review, we will examine the normal physiology of the kidney and its relationship with the immune system. We will then delve into the pathology behind persistent inflammation, the various causes of inflammation, the downstream effects of inflammation, dialysis and potential treatments for inflammation in CKD.
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Affiliation(s)
| | - Matthew Satariano
- Department of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272, USA
| | - Michael Massey
- Department of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272, USA
| | - Kai Mongan
- Department of Medicine, Northeast Ohio Medical University, Rootstown, OH 44272, USA
| | - Rupesh Raina
- Akron Nephrology Associates/Cleveland Clinic Akron General Medical Center, Akron, OH 44302, USA
- Department of Nephrology, Akron Children's Hospital, Akron, OH 44308, USA
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Kim YC, Fattah H, Fu Y, Nespoux J, Vallon V. Expression of leptin receptor in renal tubules is sparse but implicated in leptin-dependent kidney gene expression and function. Am J Physiol Renal Physiol 2023; 324:F544-F557. [PMID: 37102688 PMCID: PMC10228677 DOI: 10.1152/ajprenal.00279.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 03/30/2023] [Accepted: 04/16/2023] [Indexed: 04/28/2023] Open
Abstract
Leptin regulates energy balance via leptin receptors expressed in central and peripheral tissues, but little is known about leptin-sensitive kidney genes and the role of the tubular leptin receptor (Lepr) in response to a high-fat diet (HFD). Quantitative RT-PCR analysis of Lepr splice variants A, B, and C revealed a ratio of ∼100:10:1 in the mouse kidney cortex and medulla, with medullary levels being ∼10 times higher. Leptin replacement in ob/ob mice for 6 days reduced hyperphagia, hyperglycemia, and albuminuria, associated with normalization of kidney mRNA expression of molecular markers of glycolysis, gluconeogenesis, amino acid synthesis, and megalin. Normalization of leptin for 7 h in ob/ob mice did not normalize hyperglycemia or albuminuria. Tubular knockdown of Lepr [Pax8-Lepr knockout (KO)] and in situ hybridization revealed a minor fraction of Lepr mRNA in tubular cells compared with endothelial cells. Nevertheless, Pax8-Lepr KO mice had lower kidney weight. Moreover, while HFD-induced hyperleptinemia, increases in kidney weight and glomerular filtration rate, and a modest blood pressure lowering effect were similar compared with controls, they showed a blunted rise in albuminuria. Use of Pax8-Lepr KO and leptin replacement in ob/ob mice identified acetoacetyl-CoA synthetase and gremlin 1 as tubular Lepr-sensitive genes that are increased and reduced by leptin, respectively. In conclusion, leptin deficiency may increase albuminuria via systemic metabolic effects that impinge on kidney megalin expression, whereas hyperleptinemia may induce albuminuria by direct tubular Lepr effects. Implications of Lepr variants and the novel tubular Lepr/acetoacetyl-CoA synthetase/gremlin 1 axis remain to be determined.NEW & NOTEWORTHY This study provides new insights into kidney gene expression of leptin receptor splice variants, leptin-sensitive kidney gene expression, and the role of the leptin receptor in renal tubular cells for the response to diet-induced hyperleptinemia and obesity including albuminuria.
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Affiliation(s)
- Young Chul Kim
- Division of Nephrology and Hypertension, Department of Medicine, University of California-San Diego, La Jolla, California, United States
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| | - Hadi Fattah
- Division of Nephrology and Hypertension, Department of Medicine, University of California-San Diego, La Jolla, California, United States
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| | - Yiling Fu
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| | - Josselin Nespoux
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
| | - Volker Vallon
- Division of Nephrology and Hypertension, Department of Medicine, University of California-San Diego, La Jolla, California, United States
- Veterans Affairs San Diego Healthcare System, San Diego, California, United States
- Department of Pharmacology, University of California-San Diego, La Jolla, California, United States
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Abstract
The prevalence of obesity has increased dramatically during the past decades, which has been a major health problem. Since 1975, the number of people with obesity worldwide has nearly tripled. An increasing number of studies find obesity as a driver of chronic kidney disease (CKD) progression, and the mechanisms are complex and include hemodynamic changes, inflammation, oxidative stress, and activation of the renin-angiotensin-aldosterone system (RAAS). Obesity-related kidney disease is characterized by glomerulomegaly, which is often accompanied by localized and segmental glomerulosclerosis lesions. In these patients, the early symptoms are atypical, with microproteinuria being the main clinical manifestation and nephrotic syndrome being rare. Weight loss and RAAS blockers have a protective effect on obesity-related CKD, but even so, a significant proportion of patients eventually progress to end-stage renal disease despite treatment. Thus, it is critical to comprehend the mechanisms underlying obesity-related CKD to create new tactics for slowing or stopping disease progression. In this review, we summarize current knowledge on the mechanisms of obesity-related kidney disease, its pathological changes, and future perspectives on its treatment.
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Affiliation(s)
- Zongmiao Jiang
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, China
| | - Yao Wang
- Department of Orthopedics, The Second Hospital Jilin University, Changchun, China
| | - Xue Zhao
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, China
| | - Haiying Cui
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, China
| | - Mingyue Han
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, China
| | - Xinhua Ren
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, China
| | - Xiaokun Gang
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, China
| | - Guixia Wang
- Department of Endocrinology and Metabolism, The First Hospital of Jilin University, Changchun, China
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Shih YL, Shih CC, Chen SYF, Chen JY. Elevated serum leptin levels are associated with lower renal function among middle-aged and elderly adults in Taiwan, a community-based, cross-sectional study. Front Endocrinol (Lausanne) 2022; 13:1047731. [PMID: 36619557 PMCID: PMC9816377 DOI: 10.3389/fendo.2022.1047731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Plasma leptin is considered a risk factor for obesity and cardio-metabolic disease, but the link between serum leptin and renal function is still under evaluation. In our study, we focused on the relationship between serum leptin and renal function, and we investigated the relationship in more detail. METHODS The 396 middle-aged and elderly Taiwanese adults recruited for our health survey were the subject of our research. All participants agreed to participate and signed a consent form before they joined and completed our study. We divided the participants into three groups according to eGFR tertiles and analyzed the parameters between each group. Then, we used Pearson's correlation test to investigate the relationship between eGFR levels and cardio-metabolic risk factors with adjustment for age. The scatter plot indicates the trend between serum leptin levels and eGFR levels. Participants were reclassified into three subgroups according to their leptin levels and the bar chart reveals the prevalence of chronic kidney disease (CKD) in each group. Finally, we used multivariate linear regression to evaluate the relationship between serum leptin and eGFR levels with adjustment for age, sex, smoking status, drinking status, body mass index (BMI), uric acid levels, hypertension (HTN), diabetes mellitus (DM), and dyslipidemia. RESULTS In our study, we analyzed the data from 396 eligible participants. A total of 41.4% of the participants were male, and the average age of all participants was 64.81 years ( ± 8.78). The participants in the high eGFR group were more likely to have lower serum leptin levels. Furthermore, eGFR values were negatively correlated with serum leptin levels even after adjustment for age. The prevalence of CKD in the high serum leptin group was higher than that in the low serum leptin group. Serum leptin levels showed significant negative correlations with eGFR levels (β=-0.14, p<0.01) in the multivariate linear regression after adjusting for age, sex, smoking status, drinking status, BMI, uric acid levels, HTN, DM, and dyslipidemia. CONCLUSION According to our study, serum leptin levels show a negative relationship with eGFR levels in middle-aged and elderly people in Taiwan. In addition, high serum leptin levels could be an novel marker to survey kidney failure in clinical practices.
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Affiliation(s)
- Yu-Lin Shih
- Department of Family Medicine, Chang-Gung Memorial Hospital, Taoyuan, Taiwan
| | - Chin-Chuan Shih
- General Administrative Department, United Safety Medical Group, New Taipei, Taiwan
| | - Sun-Yi-Fan Chen
- Department of Family Medicine, Chang-Gung Memorial Hospital, Taoyuan, Taiwan
| | - Jau-Yuan Chen
- Department of Family Medicine, Chang-Gung Memorial Hospital, Taoyuan, Taiwan
- College of Medicine, Chang Gung University, Taoyuan, Taiwan
- *Correspondence: Jau-Yuan Chen,
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Sabaz MS, Aşar S, Sertçakacılar G, Sabaz N, Çukurova Z, Hergünsel GO. The effect of body mass index on the development of acute kidney injury and mortality in intensive care unit: is obesity paradox valid? Ren Fail 2021; 43:543-555. [PMID: 33745415 PMCID: PMC7993374 DOI: 10.1080/0886022x.2021.1901738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 03/03/2021] [Accepted: 03/03/2021] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND The conflicting results of studies on intensive care unit (ICU) mortality of obese patients and obese patients with acute kidney injury (AKI) reveal a paradox within a paradox. The aim of this study was to determine the effects of body mass index and obesity on AKI development and ICU mortality. METHODS The 4,459 patients treated between January 2015 and December 2019 in the ICU at a Tertiary Care Center in Turkey were analyzed retrospectively. RESULTS AKI developed more in obese patients with 69.8% (620). AKI development rates were similar in normal-weight (65.1%; 1172) and overweight patients (64.9%; 1149). The development of AKI in patients who presented with cerebrovascular diseases was higher in obese patients (81; 76.4%) than in normal-weight (158; 62.7%) and overweight (174; 60.8%) patients (p < 0.05). The risk of developing AKI was approximately 1.4 times (CI 95% = 1.177-1.662) higher in obese patients than in normal-weight patients. Dialysis was used more frequently in obese patients (24.3%, p < 0.001), who stayed longer in the ICU (p < 0.05). It was determined that the development of AKI in normal-weight and overweight patients increased mortality (p < 0.001) and that there was not a difference in mortality rates between obese patients with and without AKI. CONCLUSION The risk of AKI development was higher in obese patients but not in those who were in serious conditions. Another paradox was that the development of AKI was associated with a higher mortality rate in normal-weight and overweight patients, but not in obese patients. Cerebrovascular diseases as a cause of admission pose additional risks for AKI.
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Affiliation(s)
- Mehmet Süleyman Sabaz
- Department of Anesthesiology and Reanimation, Marmara University Pendik Training and Research Hospital, Istanbul, Turkey
| | - Sinan Aşar
- Department of Anesthesiology and Reanimation, Health Sciences University, Bakırköy Dr Sadi Konuk Training and Research Hospital, Istanbul, Turkey
| | - Gökhan Sertçakacılar
- Department of Anesthesiology and Reanimation, Health Sciences University, Bakırköy Dr Sadi Konuk Training and Research Hospital, Istanbul, Turkey
| | - Nagihan Sabaz
- Division of Nursing, Department of Pediatric Nursing, Faculty of Health Sciences, Marmara University, Istanbul, Turkey
| | - Zafer Çukurova
- Department of Anesthesiology and Reanimation, Health Sciences University, Bakırköy Dr Sadi Konuk Training and Research Hospital, Istanbul, Turkey
| | - Gülsüm Oya Hergünsel
- Department of Anesthesiology and Reanimation, Health Sciences University, Bakırköy Dr Sadi Konuk Training and Research Hospital, Istanbul, Turkey
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Miricescu D, Balan DG, Tulin A, Stiru O, Vacaroiu IA, Mihai DA, Popa CC, Enyedi M, Nedelea AS, Nica AE, Stefani C. Impact of adipose tissue in chronic kidney disease development (Review). Exp Ther Med 2021; 21:539. [PMID: 33815612 PMCID: PMC8014972 DOI: 10.3892/etm.2021.9969] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 01/14/2021] [Indexed: 12/13/2022] Open
Abstract
Obesity is a worldwide pandemic health issue. Obesity is associated with the pathogenesis of type 2 diabetes, hypertension, dyslipidemia, cardiovascular diseases, cancer, and kidney diseases. This systemic disease can affect the kidneys by two mechanisms: Indirectly through diabetes mellitus (DM) and hypertension and directly through adipokines secreted by adipose tissue. Obesity is a risk factor for chronic kidney disease (CKD), which is associated with an increased risk of morbidity and mortality among the adult population. Increased visceral adipose tissue leads to renal glomerular hyperfiltration and hyperperfusion, which may lead to glomerular hypertrophy, proteinuria, and CKD development. Adipokines are hormones produced by fat tissue. They are involved in energy homeostasis, sugar and fat metabolism, reproduction, immunity, and thermogenesis control. Hormones and cytokines secreted by adipose tissue contribute to the development and progression of CKD. Decreased serum or urinary adiponectin levels are specific in diabetic and non-diabetic CKD patients, while leptin presents increased levels, and both are associated with the development of glomerulopathy. Excessive adipose tissue is associated with inflammation, oxidative stress (OS), insulin resistance and activation of the renin angiotensin-aldosterone system (RAAS). Therefore, adipose tissue dysfunction plays an important role in the development of CKD.
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Affiliation(s)
- Daniela Miricescu
- Department of Biochemistry, Faculty of Dental Medicine, ‘Carol Davila’ University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Daniela Gabriela Balan
- Discipline of Physiology, Faculty of Dental Medicine, ‘Carol Davila’ University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Adrian Tulin
- Department of Anatomy, Faculty of Medicine, ‘Carol Davila’ University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Department of General Surgery, ‘Prof. Dr. Agrippa Ionescu’ Clinical Emergency Hospital, 011356 Bucharest, Romania
| | - Ovidiu Stiru
- Department of Cardiovascular Surgery, Faculty of Medicine, ‘Carol Davila’ University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Department of Cardiovascular Surgery, ‘Prof. Dr. C.C. Iliescu’ Emergency Institute for Cardiovascular Diseases, 022322 Bucharest, Romania
| | - Ileana Adela Vacaroiu
- Department of Nephrology and Dialysis, ‘Sf. Ioan’ Emergency Clinical Hospital, 042122 Bucharest, Romania
- Department of Nephrology, Nutrition and Metabolic Diseases, Faculty of Medicine, ‘Carol Davila’ University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Doina Andrada Mihai
- Discipline of Diabetes, Nutrition and Metabolic Diseases, Faculty of Medicine, ‘Carol Davila’ University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Department II of Diabetes, ‘Prof. N. Paulescu’ National Institute of Diabetes, Nutrition and Metabolic Diseases, 020474 Bucharest, Romania
| | - Cristian Constantin Popa
- Department of Surgery, Faculty of Medicine, ‘Carol Davila’ University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Department of Surgery, Bucharest Emergency University Hospital, 050098 Bucharest, Romania
| | - Mihaly Enyedi
- Department of Anatomy, Faculty of Medicine, ‘Carol Davila’ University of Medicine and Pharmacy, 020021 Bucharest, Romania
- Department of Radiology, ‘Victor Babes’ Private Medical Clinic, 030303 Bucharest, Romania
| | - Andrei Sorin Nedelea
- Department of Urology, ‘Prof. Dr. Agrippa Ionescu’ Clinical Emergency Hospital, 011356 Bucharest, Romania
| | - Adriana Elena Nica
- Department of Orthopedics, Anesthesia Intensive Care Unit, Faculty of Medicine, ‘Carol Davila’ University of Medicine and Pharmacy, 020021 Bucharest, Romania
| | - Constantin Stefani
- Department of Family Medicine and Clinical Base, Dr. Carol Davila Central Military Emergency University Hospital, 010825 Bucharest, Romania
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12
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Toffoli B, Tonon F, Tisato V, Michelli A, Zauli G, Secchiero P, Fabris B, Bernardi S. TRAIL treatment prevents renal morphological changes and TGF-β-induced mesenchymal transition associated with diabetic nephropathy. Clin Sci (Lond) 2020; 134:2337-52. [PMID: 32857135 DOI: 10.1042/CS20201004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND TNF-related apoptosis-inducing ligand (TRAIL) has attracted attention not only as an anti-cancer agent, but also as a potential treatment for diabetes. Animal studies have shown that TRAIL delivery ameliorated glucose control in type 1 and type 2 diabetes. It is currently unknown whether TRAIL positive effects are maintained in more severe forms of type 2 diabetes, and whether they include renoprotection. Our study aimed at evaluating TRAIL effects in a severe form of type 2 diabetes with nephropathy. MATERIALS AND METHODS A total of 20 db/db mice were treated with saline or TRAIL twice per week for 12 weeks. In parallel, renal tubular epithelial cells were cultured with TGF-β1 in the presence and absence of TRAIL, with and without silencing TRAIL-specific receptor (DR5) and leptin receptor. RESULTS TRAIL did not improve glucose control, but it significantly reduced circulating interleukin (IL)-6 and resistin. In the kidney, TRAIL treatment significantly ameliorated glomerular and tubular morphology with an improvement in kidney function, but no effect on proteinuria. Our in vitro studies on TGF-β1-treated cells, showed that by binding to DR5, TRAIL rescued normal tubular cell morphology, increasing E-cadherin and reducing α-smooth muscle actin (SMA) expression, with no effects on cell viability. Interestingly, both in vivo and in vitro, TRAIL reduced the accumulation of the autophagy substrate p62. CONCLUSIONS Our data confirm TRAIL protective effects against organ damage and shed light on to promising anti-fibrotic actions, which are independent of glucose control. TRAIL anti-fibrotic actions might be due to the rescue of autophagy in diabetes.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, TX
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14
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Abstract
Chronic kidney diseases (CKD), a common outcome of various kidney diseases, cause a series of refractory complications, which lead to great economic burdens on patients. The clinical outcomes of CKD depend on various factors, including metabolic disorders. Leptin, a peptide hormone, produced in adipose tissues, plays an important role in regulating food consumption and energy expenditure. Leptin also influences the immune system and hematopoiesis. Increased leptin status is observed in CKD, leptin deficiency attenuates the immune response in nephritis. Conversely, leptin inhibits the development of obesity, which is closely associated glomerular disorder. Now, the precise role of leptin in CKD remains elusive. This review will give an integrated understanding of the potential role of leptin and its interactions with other signal molecules in CKD.
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Affiliation(s)
- Song Mao
- a Department of Pediatrics , Shanghai Jiao Tong University Affiliated Sixth People's Hospital , Shanghai , China
| | - Li Fang
- a Department of Pediatrics , Shanghai Jiao Tong University Affiliated Sixth People's Hospital , Shanghai , China
| | - Fen Liu
- a Department of Pediatrics , Shanghai Jiao Tong University Affiliated Sixth People's Hospital , Shanghai , China
| | - Siqiong Jiang
- a Department of Pediatrics , Shanghai Jiao Tong University Affiliated Sixth People's Hospital , Shanghai , China
| | - Liangxia Wu
- a Department of Pediatrics , Shanghai Jiao Tong University Affiliated Sixth People's Hospital , Shanghai , China
| | - Jianhua Zhang
- b Department of Pediatrics, Xinhua Hospital , Shanghai Jiao Tong University School of Medicine , Shanghai , China
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15
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Yue Y, Meng K, Pu Y, Zhang X. Transforming growth factor beta (TGF-β) mediates cardiac fibrosis and induces diabetic cardiomyopathy. Diabetes Res Clin Pract 2017; 133:124-130. [PMID: 28934669 DOI: 10.1016/j.diabres.2017.08.018] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 08/03/2017] [Accepted: 08/22/2017] [Indexed: 02/07/2023]
Abstract
Cardiovascular diseases account for the major cause of morbidity and mortality among individuals with diabetes. The diabetic cardiomyopathy (DCM) is a type of diabetic cardiovascular disease, which further directs to the heart failure. The researchers found that diabetes induced cardiac fibrosis plays a vital role in several of the pathological changes that associated with DCM, causing left ventricular hypertrophy (LVH), diastolic dysfunction and systolic dysfunction. However, the mechanisms involved in the pathogenesis of DCM are still elusive. Many studies have demonstrated that the transforming growth factor beta (TGF-β) is one of the molecular mediators implicated in the progression of fibrogenesis. In diabetes, hyperglycemia causes the expression changes of microRNAs (miRNAs), long non-coding RNAs (lncRNAs), TGF-β genes, TGF-β proteins and their receptors. Activated TGF-β further leads to cardiac fibrosis, which in turn inducing DCM through the SMAD-dependent and independent pathways. Here, we reviewed the the molecular pathways that activate TGF-β then leading to cardiac fibrosis, which induced the pathological changes of DCM. Illustrating the pathways of TGF-ß would propose an efficient way for the management of diabetic cardiomyopathy (see Fig. 1).
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Affiliation(s)
- Yiyang Yue
- College of Agriculture & Biotechnology, Zhejiang University, China
| | - Ke Meng
- School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Yuejie Pu
- School of Medicine, Zhejiang University, Hangzhou 310058, China
| | - Xiaoming Zhang
- School of Medicine, Zhejiang University, Hangzhou 310058, China.
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Danziger J, Chen KP, Lee J, Feng M, Mark RG, Celi LA, Mukamal KJ. Obesity, Acute Kidney Injury, and Mortality in Critical Illness. Crit Care Med. 2016;44:328-334. [PMID: 26496453 DOI: 10.1097/ccm.0000000000001398] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVES Although obesity is associated with risk for chronic kidney disease and improved survival, less is known about the associations of obesity with risk of acute kidney injury and post acute kidney injury mortality. DESIGN In a single-center inception cohort of almost 15,000 critically ill patients, we evaluated the association of obesity with acute kidney injury and acute kidney injury severity, as well as in-hospital and 1-year survival. Acute kidney injury was defined using the Kidney Disease Outcome Quality Initiative criteria. MEASUREMENTS AND MAIN RESULTS The acute kidney injury prevalence rates for normal, overweight, class I, II, and III obesity were 18.6%, 20.6%, 22.5%, 24.3%, and 24.0%, respectively, and the adjusted odds ratios of acute kidney injury were 1.18 (95% CI, 1.06-1.31), 1.35 (1.19-1.53), 1.47 (1.25-1.73), and 1.59 (1.31-1.87) when compared with normal weight, respectively. Each 5-kg/m² increase in body mass index was associated with a 10% risk (95% CI, 1.06-1.24; p < 0.001) of more severe acute kidney injury. Within-hospital and 1-year survival rates associated with the acute kidney injury episodes were similar across body mass index categories. CONCLUSION Obesity is a risk factor for acute kidney injury, which is associated with increased short- and long-term mortality.
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Abstract
In the last two decades, perceptions about the role of body fat have changed. Adipocytes modulate endocrine and immune homeostasis by synthesizing hundreds of hormones, known as adipocytokines. Many studies have been investigating the influences and effects of these adipocytokines and suggest that they are modulated by the nutritional and immunologic milieu. Kidney transplant recipients (KTRs) are a unique and relevant population in which the function of adipocytokines can be examined, given their altered nutritional and immune status and subsequent dysregulation of adipocytokine metabolism. In this review, we summarize the recent findings about four specific adipocytokines and their respective roles in KTRs. We decided to evaluate the most widely described adipocytokines, including leptin, adiponectin, visfatin and resistin. Increasing evidence suggests that these adipocytokines may lead to cardiovascular events and metabolic changes in the general population and may also increase mortality and graft loss rate in KTRs. In addition, we present findings on the interrelationship between serum adipocytokine levels and nutritional and immunologic status, and mechanisms by which adipocytokines modulate morbidity and outcomes in KTRs.
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Affiliation(s)
- Kristof Nagy
- Department of Transplantation and Surgery , Semmelweis University , Budapest , Hungary
| | | | - Connie M Rhee
- Harold Simmons Center for Chronic Disease Research and Epidemiology, Division of Nephrology and Hypertension , University of California Irvine , Orange, CA , USA
| | - Zoltan Mathe
- Department of Transplantation and Surgery , Semmelweis University , Budapest , Hungary
| | - Miklos Z Molnar
- Division of Nephrology, Department of Medicine , University of Tennessee Health Science Center , Memphis, TN , USA
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19
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Thieme K, Oliveira-Souza M. Renal hemodynamic and morphological changes after 7 and 28 days of leptin treatment: the participation of angiotensin II via the AT1 receptor. PLoS One 2015; 10:e0122265. [PMID: 25793389 PMCID: PMC4368722 DOI: 10.1371/journal.pone.0122265] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 02/17/2015] [Indexed: 01/13/2023] Open
Abstract
The role of hyperleptinemia in cardiovascular diseases is well known; however, in the renal tissue, the exact site of leptin’s action has not been established. This study was conducted to assess the effect of leptin treatment for 7 and 28 days on renal function and morphology and the participation of angiotensin II (Ang II), through its AT1 receptor. Rats were divided into four groups: sham, losartan (10 mg/kg/day, s.c.), leptin (0.5 mg/kg/day for the 7 days group and 0.25 mg/kg/day for the 28 days group) and leptin plus losartan. Plasma leptin, Ang II and endothelin 1 (ET-1) levels were measured using an enzymatic immuno assay. The systolic blood pressure (SBP) was evaluated using the tail-cuff method. The renal plasma flow (RPF) and the glomerular filtration rate (GFR) were determined by p-aminohippuric acid and inulin clearance, respectively. Urinary Na+ and K+ levels were also analyzed. Renal morphological analyses, desmin and ED-1 immunostaining were performed. Proteinuria was analyzed by silver staining. mRNA expression of renin-angiotensin system (RAS) components, TNF-α and collagen type III was analyzed by quantitative PCR. Our results showed that leptin treatment increased Ang II plasma levels and progressively increased the SBP, achieving a pre-hypertension state. Rats treated with leptin 7 days showed a normal RPF and GFR, but increased filtration fraction (FF) and natriuresis. However, rats treated with leptin for 28 showed a decrease in the RPF, an increase in the FF and no changes in the GFR or tubular function. Leptin treatment-induced renal injury was demonstrated by: glomerular hypertrophy, increased desmin staining, macrophage infiltration in the renal tissue, TNF-α and collagen type III mRNA expression and proteinuria. In conclusion, our study demonstrated the progressive renal morphological changes in experimental hyperleptinemia and the interaction between leptin and the RAS on these effects.
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Affiliation(s)
- Karina Thieme
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- * E-mail:
| | - Maria Oliveira-Souza
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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20
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Prasad GVR. Metabolic syndrome and chronic kidney disease: Current status and future directions. World J Nephrol 2014; 3:210-219. [PMID: 25374814 PMCID: PMC4220353 DOI: 10.5527/wjn.v3.i4.210] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/26/2014] [Accepted: 09/24/2014] [Indexed: 02/06/2023] Open
Abstract
Metabolic syndrome (MetS) is a term used to denote a combination of selected, widely prevalent cardiovascular disease (CVD)-related risk factors. Despite the ambiguous definition of MetS, it has been clearly associated with chronic kidney disease markers including reduced glomerular filtration rate, proteinuria and/or microalbuminuria, and histopathological markers such as tubular atrophy and interstitial fibrosis. However, the etiological role of MetS in chronic kidney disease (CKD) is less clear. The relationship between MetS and CKD is complex and bidirectional, and so is best understood when CKD is viewed as a common progressive illness along the course of which MetS, another common disease, may intervene and contribute. Possible mechanisms of renal injury include insulin resistance and oxidative stress, increased proinflammatory cytokine production, increased connective tissue growth and profibrotic factor production, increased microvascular injury, and renal ischemia. MetS also portends a higher CVD risk at all stages of CKD from early renal insufficiency to end-stage renal disease. Clinical interventions for MetS in the presence of CKD should include a combination of weight reduction, appropriate dietary modification and increase physical activity, plus targeting of individual CVD-related risk factors such as dysglycemia, hypertension, and dyslipidemia while conforming to relevant national societal guidelines.
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21
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Ibrahim HS, Froemming GRA, Omar E, Singh HJ. ACE2 activation by xanthenone prevents leptin-induced increases in blood pressure and proteinuria during pregnancy in Sprague-Dawley rats. Reprod Toxicol 2014; 49:155-61. [DOI: 10.1016/j.reprotox.2014.08.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 08/04/2014] [Accepted: 08/25/2014] [Indexed: 12/13/2022]
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22
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Abstract
Increasing incidence of chronic kidney disease (CKD) which leads to end-stage renal disease (ESRD) is one of the major health issues in the modern world and requires novel strategies for treatment. Adipose tissue has been recognized to have endocrine function and secretes a variety of hormones called adipokines. Several adipokines have been implicated in the pathogenesis of CKD and may have a strong impact as a risk factor for renal decline. The aim of this review is to provide an overview of the role of adipokines in the progression of CKD, with focus on recent experimental and clinical advances.
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Affiliation(s)
- Satoshi Miyamoto
- Center for Renal Translational Medicine, University of California San Diego/Veterans Affairs San Diego Healthcare System, La Jolla, CA, USA
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23
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Abstract
Vitamin D₃ receptor (VDR) signaling within the mammary gland regulates various postnatal stages of glandular development, including puberty, pregnancy, involution, and tumorigenesis. Previous studies have shown that vitamin D₃ treatment induces cell-autonomous growth inhibition and differentiation of mammary epithelial cells in culture. Furthermore, mammary adipose tissue serves as a depot for vitamin D₃ storage, and both epithelial cells and adipocytes are capable of bioactivating vitamin D₃. Despite the pervasiveness of VDR in mammary tissue, individual contributions of epithelial cells and adipocytes, as well as the VDR-regulated cross-talk between these two cell types during pubertal mammary development, have yet to be investigated. To assess the cell-type specific effect of VDR signaling during pubertal mammary development, novel mouse models with mammary epithelial- or adipocyte-specific loss of VDR were generated. Interestingly, loss of VDR in either cellular compartment accelerated ductal morphogenesis with increased epithelial cell proliferation and decreased apoptosis within terminal end buds. Conversely, VDR signaling specifically in the mammary epithelium modulated hormone-induced alveolar growth, as ablation of VDR in this cell type resulted in precocious alveolar development. In examining cellular cross-talk ex vivo, we show that ligand-dependent VDR signaling in adipocytes significantly inhibits mammary epithelial cell growth in part through the vitamin D₃-dependent production of the cytokine IL-6. Collectively, these studies delineate independent roles for vitamin D₃-dependent VDR signaling in mammary adipocytes and epithelial cells in controlling pubertal mammary gland development.
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MESH Headings
- Adipocytes, White/cytology
- Adipocytes, White/metabolism
- Adipogenesis
- Animals
- Apoptosis
- Cell Communication
- Cell Proliferation
- Cells, Cultured
- Cholecalciferol/metabolism
- Crosses, Genetic
- Epithelial Cells/cytology
- Epithelial Cells/metabolism
- Female
- Gene Expression Regulation, Developmental
- Interleukin-6/genetics
- Interleukin-6/metabolism
- Mammary Glands, Animal/cytology
- Mammary Glands, Animal/growth & development
- Mammary Glands, Animal/metabolism
- Mice, Inbred C57BL
- Mice, Transgenic
- Receptors, Calcitriol/agonists
- Receptors, Calcitriol/genetics
- Receptors, Calcitriol/metabolism
- Sexual Maturation
- Signal Transduction
- Specific Pathogen-Free Organisms
- Tissue Culture Techniques
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Affiliation(s)
| | - Glendon M Zinser
- Departments of Environmental Health and Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio; and
| | - Susan E Waltz
- Cancer Biology, University of Cincinnati College of Medicine, Cincinnati, Ohio; and Research Service, Cincinnati Veterans Affairs Medical Center, Cincinnati, Ohio
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Cavalera M, Wang J, Frangogiannis NG. Obesity, metabolic dysfunction, and cardiac fibrosis: pathophysiological pathways, molecular mechanisms, and therapeutic opportunities. Transl Res 2014; 164:323-35. [PMID: 24880146 PMCID: PMC4180761 DOI: 10.1016/j.trsl.2014.05.001] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/28/2014] [Accepted: 05/03/2014] [Indexed: 02/09/2023]
Abstract
Cardiac fibrosis is strongly associated with obesity and metabolic dysfunction and may contribute to the increased incidence of heart failure, atrial arrhythmias, and sudden cardiac death in obese subjects. This review discusses the evidence linking obesity and myocardial fibrosis in animal models and human patients, focusing on the fundamental pathophysiological alterations that may trigger fibrogenic signaling, the cellular effectors of fibrosis, and the molecular signals that may regulate the fibrotic response. Obesity is associated with a wide range of pathophysiological alterations (such as pressure and volume overload, metabolic dysregulation, neurohumoral activation, and systemic inflammation); their relative role in mediating cardiac fibrosis is poorly defined. Activation of fibroblasts likely plays a major role in obesity-associated fibrosis; however, inflammatory cells, cardiomyocytes, and vascular cells may also contribute to fibrogenic signaling. Several molecular processes have been implicated in regulation of the fibrotic response in obesity. Activation of the renin-angiotensin-aldosterone system, induction of transforming growth factor β, oxidative stress, advanced glycation end-products, endothelin 1, Rho-kinase signaling, leptin-mediated actions, and upregulation of matricellular proteins (such as thrombospondin 1) may play a role in the development of fibrosis in models of obesity and metabolic dysfunction. Moreover, experimental evidence suggests that obesity and insulin resistance profoundly affect the fibrotic and remodeling response after cardiac injury. Understanding the pathways implicated in obesity-associated fibrosis may lead to the development of novel therapies to prevent heart failure and attenuate postinfarction cardiac remodeling in patients with obesity.
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Affiliation(s)
- Michele Cavalera
- Division of Cardiology, Department of Medicine, The Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York
| | - Junhong Wang
- Division of Cardiology, Department of Medicine, The Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York
| | - Nikolaos G Frangogiannis
- Division of Cardiology, Department of Medicine, The Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York.
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25
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Alix PM, Guebre-Egziabher F, Soulage CO. Leptin as an uremic toxin: Deleterious role of leptin in chronic kidney disease. Biochimie 2014; 105:12-21. [PMID: 25010649 DOI: 10.1016/j.biochi.2014.06.024] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 06/30/2014] [Indexed: 12/27/2022]
Abstract
White adipose tissue secretes a large variety of compounds named adipokines amongst which, leptin exhibits pleiotropic metabolic actions. Leptin is an anorexigenic hormone, secreted in proportion of fat mass, with additional effects on the regulation of inflammation, cardiovascular system, immunity, hematopoiesis and bone metabolism. Chronic kidney disease (CKD) is characterized by an increase of plasma leptin concentration that may be explained by a lack of renal clearance. Hyperleptinemia plays a key role in the pathogenesis of complications associated with CKD such as cachexia, protein energy wasting, chronic inflammation, insulin resistance, cardiovascular damages and bone complications. Leptin is also involved in the progression of renal disease through its pro-fibrotic and pro-hypertensive actions. Most of the adverse effects of leptin have been documented both experimentally and clinically. Leptin may therefore be considered as an uremic toxin in CKD. The aim of this review is to summarize the pathophysiological and clinical role of leptin in in vitro studies, experimental models, as well as in patients suffering from CKD.
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Affiliation(s)
- Pascaline M Alix
- Université de Lyon, INSERM U1060, CarMeN, INSA de Lyon, Univ Lyon-1, F-69621 Villeurbanne, France; Hospices Civils de Lyon, Department of Nephrology, Hôpital E Herriot, Lyon F-69003, France.
| | - Fitsum Guebre-Egziabher
- Université de Lyon, INSERM U1060, CarMeN, INSA de Lyon, Univ Lyon-1, F-69621 Villeurbanne, France; Hospices Civils de Lyon, Department of Nephrology, Hôpital E Herriot, Lyon F-69003, France
| | - Christophe O Soulage
- Université de Lyon, INSERM U1060, CarMeN, INSA de Lyon, Univ Lyon-1, F-69621 Villeurbanne, France
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26
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Lin HY, Yang SH, Tang HY, Cheng GY, Davis PJ, Grasso P. Biologically active leptin-related synthetic peptides activate STAT3 via phosphorylation of ERK1/2 and PI-3K. Peptides 2014; 57:95-100. [PMID: 24819473 DOI: 10.1016/j.peptides.2014.04.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 04/09/2014] [Accepted: 04/09/2014] [Indexed: 11/26/2022]
Abstract
The effects of leptin-related synthetic peptides [d-Leu-4]-OB3 and OB3 on energy balance and glucose homeostasis in ob/ob and db/db mice have been confirmed. The molecular basis of these effects, however, remains unclear. In the present study, we examined the ability of these peptides to activate signal transduction pathways known to be involved in transduction of the leptin signal. In a specific and concentration-dependent manner, [d-Leu-4]-OB3 induced phosphorylation of ERK1/2, PI-3K, Ser-727 STAT3, and Tyr-705 of STAT3. OB3 also induced activation of STAT3 via phosphorylation of ERK1/2, STAT3 Ser-727, STAT3 Tyr-705 and PI-3K p85, but to a lesser degree. Using PD98059 and LY294002, specific inhibitors of MEK and PI-3K, respectively, we were able to identify the signal transduction pathways involved in peptide-induced STAT3 activation. [d-Leu-4]-OB3 induced serine phosphorylation of STAT3 primarily through activation of ERK1/2. Tyrosine phosphorylation of STAT3, however, was induced primarily through activation of PI-3K. Our data suggest that in db/db mice, [d-Leu-4]-OB3 binding to short isoforms of the leptin receptor induces intracellular signaling cascades which do not require OB-Rb activation. These signals may ultimately result in peptide effects on transcriptional and translational events associated with energy balance and glycemic regulation. In summary, we have shown for the first time that, similar to leptin, bioactive leptin-related synthetic peptide analogs activate STAT3 via phosphorylation of serine and tyrosine residues by multiple signal transduction pathways.
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Affiliation(s)
- Hung-Yun Lin
- Taipei Cancer Center, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan; Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Sheng-Huei Yang
- Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Heng-Yuan Tang
- Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Rensselaer, NY 12144, USA
| | - Guei-Yun Cheng
- Taipei Cancer Center, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Paul J Davis
- Department of Medicine, Division of Endocrinology and Metabolism, Albany Medical College, Albany, NY 12208, USA
| | - Patricia Grasso
- Department of Medicine, Division of Endocrinology and Metabolism, Albany Medical College, Albany, NY 12208, USA.
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Martínez-martínez E, Jurado-lópez R, Valero-muñoz M, Bartolomé MV, Ballesteros S, Luaces M, Briones AM, López-andrés N, Miana M, Cachofeiro V. Leptin induces cardiac fibrosis through galectin-3, mTOR and oxidative stress: potential role in obesity. J Hypertens 2014; 32:1104-14. [DOI: 10.1097/hjh.0000000000000149] [Citation(s) in RCA: 94] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Martínez-Martínez E, Miana M, Jurado-López R, Bartolomé MV, Souza Neto FV, Salaices M, López-Andrés N, Cachofeiro V. The potential role of leptin in the vascular remodeling associated with obesity. Int J Obes (Lond) 2014; 38:1565-72. [PMID: 24583853 DOI: 10.1038/ijo.2014.37] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 02/06/2014] [Accepted: 02/24/2014] [Indexed: 12/22/2022]
Abstract
BACKGROUND/OBJECTIVES Extracellular matrix (ECM) participates in the vascular remodeling associated with obesity. We investigated the effects of leptin on the production of ECM components in primary cultured vascular smooth muscle cells (VSMCs) and whether leptin could be a mediator of obesity-induced vascular remodeling. METHODS T he effects of leptin (100 ng ml(-1)) on ECM components and superoxide anion production (O(2)(.-)) were evaluated in presence or absence of the antioxidant melatonin (10(-)(3) mmol l(-1)) or the inhibitor of phosphatidylinositol 3'-kinase (PI3K), LY294002 (2 × 10(-)(4) mmol l(-1)) in VSMCs from adult rats in order to explore the role of both oxidative stress and the participation of PI3K/Akt pathway in the effects of leptin. ECM components and O(2)(.-) were quantified in the aortic media of male Wistar rats fed a high-fat diet (HFD; 33.5% fat), or a standard diet (CT; 3.5% fat) for 6 weeks. RESULTS In VSMCs, leptin enhanced gene and protein levels of collagen I, fibronectin, transforming growth factor (TGF)-β and connective tissue growth factor (CTGF) but did not change those of collagen III and galectin-3. Leptin also increased O(2)(.-) and Akt phosphorylation in VSMCs. These effects were prevented by the presence of either melatonin or LY294002, except O(2)(.-) production in the case of PI3K inhibition. The increase in body weight in HFD rats was accompanied by aorta thickening due to an increase in media area. The aortic fibrosis observed in HFD rats was associated with high levels of leptin, collagen type I, fibronectin, TGF-β, CTGF, phosphorylated Akt and O(2)(.-). Aortic leptin levels were positively correlated with total collagen, collagen I, TGF-β and CTGF levels. No differences were observed in the levels of collagen III, elastin or galectin-3 between both the groups. CONCLUSIONS Leptin could participate in the vascular remodeling and stiffness associated with obesity by ECM production in VSMCs through the activation of oxidative stress-PI3K/Akt pathway and the production of the profibrotic factors TGF-β and CTGF.
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Briffa JF, Grinfeld E, McAinch AJ, Poronnik P, Hryciw DH. Short term exposure to elevated levels of leptin reduces proximal tubule cell metabolic activity. Mol Cell Endocrinol 2014; 382:38-45. [PMID: 24036423 DOI: 10.1016/j.mce.2013.09.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 08/08/2013] [Accepted: 09/03/2013] [Indexed: 11/29/2022]
Abstract
Leptin plays a pathophysiological role in the kidney, however, its acute effects on the proximal tubule cells (PTCs) are unknown. In opossum kidney (OK) cells in vitro, Western blot analysis identified that exposure to leptin increases the phosphorylation of the mitogen-activated protein kinase (MAPK) p44/42 and the mammalian target of rapamycin (mTOR). Importantly leptin (0.05, 0.10, 0.25 and 0.50 μg/ml) significantly reduced the metabolic activity of PTCs, and significantly decreased protein content per cell. Investigation of the role of p44/42 and mTOR on metabolic activity and protein content per cell, demonstrated that in the presence of MAPK inhibitor U0126 and mTOR inhibitor Ku-63794, that the mTOR pathway is responsible for the reduction in PTC metabolic activity in response to leptin. However, p44/42 and mTOR play no role the reduced protein content per cell in OKs exposed to leptin. Therefore, leptin modulates metabolic activity in PTCs via an mTOR regulated pathway.
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Affiliation(s)
- Jessica F Briffa
- Biomedical and Lifestyle Diseases (BioLED) Unit, College of Health and Biomedicine, Victoria University, St Albans, VIC 3021, Australia; Department of Physiology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Esther Grinfeld
- Biomedical and Lifestyle Diseases (BioLED) Unit, College of Health and Biomedicine, Victoria University, St Albans, VIC 3021, Australia
| | - Andrew J McAinch
- Biomedical and Lifestyle Diseases (BioLED) Unit, College of Health and Biomedicine, Victoria University, St Albans, VIC 3021, Australia
| | - Philip Poronnik
- School of Medical Sciences, The Bosch Institute, The University of Sydney, NSW 2006, Australia
| | - Deanne H Hryciw
- Biomedical and Lifestyle Diseases (BioLED) Unit, College of Health and Biomedicine, Victoria University, St Albans, VIC 3021, Australia; Department of Physiology, The University of Melbourne, Parkville, VIC 3010, Australia.
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Chen J, Mo H, Guo R, You Q, Huang R, Wu K. Inhibition of the leptin-induced activation of the p38 MAPK pathway contributes to the protective effects of naringin against high glucose-induced injury in H9c2 cardiac cells. Int J Mol Med 2014; 33:605-12. [PMID: 24399619 DOI: 10.3892/ijmm.2014.1614] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 12/24/2013] [Indexed: 11/05/2022] Open
Abstract
Leptin, a product of the obese gene, has been reported to contribute to the development of cardiomyocyte hypertrophy in patients with diabetes and to activate the p38 mitogen-activated protein kinase (MAPK) pathway in cardiomyocytes. In this study, we demonstrate that naringin, a citrus flavonone, protects cardiomyoblasts (H9c2 cells) against high glucose (HG)-induced apoptosis by modulating the activation of the p38 MAPK pathway. We investigated the hypothesis that naringin prevents HG-induced injury by inhibiting the leptin-induced activation of the p38 MAPK pathway in H9c2 cells. Our results demonstrated that the exposure of H9c2 cells to HG (35 mmol/l) for a 24 h markedly upregulated the expression levels of both leptin and leptin receptors. However, the increase in the expression levels of leptin and leptin receptors was greatly attenuated by treatment of the H9c2 cells with 80 µmol/l naringin 2 h prior to exposure to HG. In addition, treatment of the cells with 50 ng/ml leptin antagonist (LA) for 24 h prior to exposure to HG markedly ameliorated the increased expression of phosphorylated (p)-p38 MAPK induced by HG. Of note, pre-treatment of the cells with either 80 µmol/l naringin or 50 ng/ml LA markedly inhibited the HG-induced injury, leading to an increase in cell viability and a decrease in the total number of apoptotic cells, preventing reactive oxygen species (ROS) generation, as well as the dissipation of mitochondrial membrane potential (MMP). In conclusion, the findings of the present study provide the first evidence that the leptin-induced activation of the p38 MAPK pathway is involved in HG-induced injury, including cytotoxicity, apoptosis, ROS generation and the dissipation of MMP in H9c2 cardiac cells. Our data demonstrate that naringin protects cardiac cells against HG-induced injury by inhibiting the leptin-induced activation of the p38 MAPK pathway.
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Affiliation(s)
- Jingfu Chen
- Department of Cardiovasology, The Affiliated Hospital, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Hailiang Mo
- Department of Cardiovasology, The Affiliated Hospital, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Runmin Guo
- Department of Cardiovasology, The Affiliated Hospital, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Qiong You
- Department of Cardiovasology, The Affiliated Hospital, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Ruina Huang
- Department of Cardiovasology, The Affiliated Hospital, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
| | - Keng Wu
- Department of Cardiovasology, The Affiliated Hospital, Guangdong Medical College, Zhanjiang, Guangdong 524001, P.R. China
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Abstract
Chronic kidney disease (CKD) is defined by the National Kidney Foundation Kidney Disease Outcomes Quality Initiative as the presence of reduced kidney function or kidney damage for a period of 3 months or greater. Obesity is considered a risk factor for CKD development, but its precise role in contributing to CKD and end stage kidney disease is not fully elucidated. In this narrative review, the objectives are to describe the pathogenesis of CKD in obesity, including the impact of altered adipokine secretion in obesity and CKD, and to provide an overview of the clinical studies assessing the risk of obesity and CKD development.
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Affiliation(s)
- Jocelyn S Garland
- Department of Medicine, Queen’s University, Kingston, ON, Canada
- Correspondence: Jocelyn S Garland, Room 2043, Etherington Hall, Queen’s University, Kingston, ON K7L 3N6, Canada, Tel +1 613 533 3207, Fax +1 613 533 2306, Email
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Abstract
Diabetes mellitus contributes greatly to morbidity, mortality, and overall health care costs. In major part, these outcomes derive from the high incidence of progressive kidney dysfunction in patients with diabetes making diabetic nephropathy a leading cause of end-stage renal disease. A better understanding of the molecular mechanism involved and of the early dysfunctions observed in the diabetic kidney may permit the development of new strategies to prevent diabetic nephropathy. Here we review the pathophysiological changes that occur in the kidney in response to hyperglycemia, including the cellular responses to high glucose and the responses in vascular, glomerular, podocyte, and tubular function. The molecular basis, characteristics, and consequences of the unique growth phenotypes observed in the diabetic kidney, including glomerular structures and tubular segments, are outlined. We delineate mechanisms of early diabetic glomerular hyperfiltration including primary vascular events as well as the primary role of tubular growth, hyperreabsorption, and tubuloglomerular communication as part of a "tubulocentric" concept of early diabetic kidney function. The latter also explains the "salt paradox" of the early diabetic kidney, that is, a unique and inverse relationship between glomerular filtration rate and dietary salt intake. The mechanisms and consequences of the intrarenal activation of the renin-angiotensin system and of diabetes-induced tubular glycogen accumulation are discussed. Moreover, we aim to link the changes that occur early in the diabetic kidney including the growth phenotype, oxidative stress, hypoxia, and formation of advanced glycation end products to mechanisms involved in progressive kidney disease.
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Affiliation(s)
- Volker Vallon
- Department of Medicine, University of California San Diego & VA San Diego Healthcare System, San Diego, California, USA.
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Affiliation(s)
- Belinda Spoto
- CNR-IBIM & Nephrology, Dialysis and Transplantation Unit of Reggio Calabria, Reggio Calabria, Italy
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Abstract
Obesity is a recognized risk factor for breast cancer development and poorer response to therapy. Two major fat tissue-derived adipokines, leptin and adiponectin have been implicated in mammary carcinogenesis. Leptin appears to promote breast cancer progression through activation of mitogenic, antiapoptotic, and metastatic pathways, while adiponectin may restrict tumorigenic processes primarily by inhibiting cell metabolism. Furthermore, adiponectin is known to counteract detrimental leptin effects in breast cancer models. Thus, therapeutic inhibition of pro-neoplastic leptin pathways and reactivation of anti-neoplastic adiponectin signaling may benefit breast cancer patients, especially the obese subpopulation. This review focuses on current experimental strategies aiming at leptin and adiponectin pathways in breast cancer models. Novel leptin receptor antagonists and adiponectin receptor agonists as well as other compounds for therapeutic modulation of adipokine pathways are discussed in detail, including potential pharmacological advantages and limitations of these approaches.
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Affiliation(s)
- Eva Surmacz
- Sbarro Institute for Cancer Research and Molecular Medicine, Temple University, 1900 N12th Street, BioLife Bldg. Rm 425, Philadelphia, PA, 19122, USA,
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Kim D, Lee JE, Jung YJ, Lee AS, Lee S, Park SK, Kim SH, Park BH, Kim W, Kang KP. Metformin decreases high-fat diet-induced renal injury by regulating the expression of adipokines and the renal AMP-activated protein kinase/acetyl-CoA carboxylase pathway in mice. Int J Mol Med 2013; 32:1293-302. [PMID: 24068196 DOI: 10.3892/ijmm.2013.1508] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 09/18/2013] [Indexed: 11/06/2022] Open
Abstract
Metabolic syndrome is characterized by insulin resistance, dyslipidemia and hypertension. These metabolic changes contribute to the development of obesity-induced kidney injury. AMP-activated protein kinase (AMPK) is a ubiquitous enzyme that is involved in the cellular metabolic response to metabolic stress. Metformin, an AMPK activator, has been reported to exert a protective effect against non-alcoholic steatohepatitis. However, little is known about its role in the pathogenesis of obesity-induced renal injury. The aim of this study was to investigate the effects of metformin on high-fat diet (HFD)-induced kidney injury. Obesity was induced by HFD (60% of total calories from fat, 20% protein and 20% carbohydrates) in 6-week-old C57BL/6 mice. Mice were fed HFD plus 0.5% metformin. The effects of metformin on HFD-induced renal injury were evaluated by determining metabolic parameters, serum adipokine levels and renal AMPK/acetyl-CoA carboxylase (ACC) activities, as well as a histological examination. HFD induced metabolic derangement, systemic insulin resistance and glomerular mesangial matrix expansion. The administration of metformin reduced HFD-induced metabolic derangement and renal injury. The administration of metformin reduced the HFD-induced increase in adipokine expression and macrophage infiltration. Moreover, renal AMPK activity, which was decreased by HFD, was recovered following the administration of metformin; in addition, fatty acid oxidation was increased by the inhibition of ACC. These results indicate that metformin exerts beneficial effects on obesity-induced renal injury by regulating systemic inflammation, insulin resistance and the renal AMPK/ACC pathway. The clinical application of metformin to obese or early diabetic patients may be helpful in preventing obesity- or diabetes-related kidney disease.
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Affiliation(s)
- Dal Kim
- Department of Internal Medicine, Research Institute of Clinical Medicine and Diabetes Research Center, Chonbuk National University Medical School, Deokjin-gu, Jeonju 561-712, Republic of Korea
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Ibrahim HS, Omar E, Froemming GR, Singh HJ. Leptin increases blood pressure and markers of endothelial activation during pregnancy in rats. Biomed Res Int 2013; 2013:298401. [PMID: 24167814 DOI: 10.1155/2013/298401] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 08/13/2013] [Accepted: 08/23/2013] [Indexed: 12/31/2022]
Abstract
Raised leptin levels have been reported in the placentae and serum of women with elevated blood pressure and proteinuria during pregnancy. The role of leptin in this however remains unknown. This study investigates the effect of leptin administration on systolic blood pressure (SBP) and proteinuria and serum markers of endothelial activation during pregnancy in Sprague Dawley rats. From day 1 of pregnancy, 24 rats were randomised into those given either saline (group 1) or leptin at 60 or 120 μ g/kg/body weight/day (groups 2 and 3 resp.). SBP was measured every 5 days and 24-h urinary protein was measured at days 0 and 20 of pregnancy. Animals were euthanised on day 20 of pregnancy, and serum was collected for estimation of E-selectin and ICAM-1. Compared to group 1, SBP during the latter part of the pregnancy was significantly higher in the leptin-treated group (P < 0.01). Urinary protein excretion, serum E-selectin, and ICAM-1 were significantly higher in leptin-treated rats (P < 0.05). It seems that leptin administration to normotensive Sprague Dawley rats during pregnancy significantly increases SBP, urinary protein excretion, and markers of endothelial activation. However, further studies are required to examine the underlying mechanism responsible for this and its relevance to preeclampsia in humans.
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Cui W, Maimaitiyiming H, Qi X, Norman H, Wang S. Thrombospondin 1 mediates renal dysfunction in a mouse model of high-fat diet-induced obesity. Am J Physiol Renal Physiol 2013; 305:F871-80. [PMID: 23863467 PMCID: PMC3761287 DOI: 10.1152/ajprenal.00209.2013] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 07/04/2013] [Indexed: 11/22/2022] Open
Abstract
Obesity is prevalent worldwide and is a major risk factor for many diseases including renal complications. Thrombospondin 1 (TSP1), a multifunctional extracellular matrix protein, plays an important role in diabetic kidney diseases. However, whether TSP1 plays a role in obesity-related kidney disease is unknown. In the present studies, the role of TSP1 in obesity-induced renal dysfunction was determined by using a diet-induced obese mouse model. The results demonstrated that TSP1 was significantly upregulated in the kidney from obese mice. The increased TSP1 was localized in the glomerular mesangium as well as in the tubular system from obese wild-type mice. Obese wild-type mice developed renal hypertrophy and albuminuria, which was associated with increased kidney macrophage infiltration, augmented kidney inflammation, and activated transforming growth factor (TGF)-β signaling and renal fibrosis. In contrast, obese TSP1-deficient mice did not develop these kidney damages. Furthermore, in vitro studies demonstrated that leptin treatment stimulated the expression of TSP1, TGF-β1, fibronectin, and collagen type IV in mesangial cells isolated from wild-type mice. These leptin-stimulated effects were abolished in TSP1-deficient mesangial cells. Taken together, these data suggest that TSP1 is an important mediator for obesity- or hyperleptinemia-induced kidney dysfunction.
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Affiliation(s)
- Wenpeng Cui
- Graduate Center for Nutritional Sciences, Univ. of Kentucky, Wethington Bldg. Rm. 583, 900 S. Limestone St., Lexington, KY 40536.
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Abu-tair L, Doron S, Mahamid M, Amer J, Safadi R. Leptin modulates lymphocytes' adherence to hepatic stellate cells is associated with oxidative status alterations. Mitochondrion 2013; 13:473-80. [DOI: 10.1016/j.mito.2012.10.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Revised: 10/15/2012] [Accepted: 10/16/2012] [Indexed: 12/15/2022]
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Abstract
PURPOSE OF REVIEW The association of the metabolic syndrome (MetS) with cardiovascular risk, mortality, type 2 diabetes mellitus, stroke, nonfatty liver disease and gout is well known. However, the association of the MetS with chronic kidney disease (CKD) is now emerging. This review discusses the epidemiology, pathology and potential mechanisms for the relationship of MetS with CKD. RECENT FINDINGS Studies show that patients with MetS have a 2.5-fold higher risk of developing CKD. The risk of microalbuminuria is also increased two-fold in the MetS. Renal dysfunction becomes apparent long before the appearance of hypertension or diabetes in MetS. Compared with healthy controls, patients with MetS have increased microvascular disease-tubular atrophy, interstitial fibrosis, arterial sclerosis and global and segmental sclerosis. Studies suggest that the renal fibrosis seen in MetS might be caused by a constellation of insulin resistance, hypertension, dyslipidemias and inflammation, and result in a heightened expression of adipocytokines, angiotensin and inflammatory cytokines such as interleukin-6 and tumour necrosis factor-alpha. SUMMARY Despite the strong association of MetS with CKD, a causal relationship has not been proven. More studies are needed to precisely elucidate the mechanisms that might lead upstream factors such as insulin resistance, hypertension, dyslipidemia and inflammation to cause renal fibrosis.
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Abstract
The adipocyte product leptin is a pleiotropic adipokine and hormone, with a role extending beyond appetite suppression and increased energy expenditure. This review summarizes the biology of the leptin system and the roles of its different receptors in a multitude of cellular functions in different organs, with special emphasis on the kidney. Leptin's physiological functions as well as deleterious effects in states of leptin deficiency or hyperleptinemia are emphasized. Chronic hyperleptinemia can increase blood pressure through the sympathetic nervous system and renal salt retention. The concept of selective leptin resistance in obesity is emerging, whereby leptin's effect on appetite and energy expenditure is blunted, with a concomitant increase in leptin's other effects as a result of the accompanying hyperleptinemia. The divergence in response likely is explained by different receptors and post-receptor activating mechanisms. Chronic kidney disease is a known cause of hyperleptinemia. There is an emerging view that the effect of hyperleptinemia on the kidney can contribute to the development and/or progression of chronic kidney disease in selective resistance states such as in obesity or type 2 diabetes mellitus. The mechanisms of renal injury are likely the result of exaggerated and undesirable hemodynamic influences as well as profibrotic effects.
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Affiliation(s)
- Mona P Nasrallah
- Department of Internal Medicine, American University of Beirut, Beirut, Lebanon.
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Novakovic ZM, Leinung MC, Grasso P. [D-Leu-4]-OB3, an orally bioavailable leptin-related synthetic peptide insulin sensitizer: a study comparing the efficacies of [D-Leu-4]-OB3 and metformin on energy balance and glycemic regulation in insulin-deficient male Swiss Webster mice. Peptides 2013; 43:167-73. [PMID: 23500518 DOI: 10.1016/j.peptides.2013.02.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 02/28/2013] [Accepted: 02/28/2013] [Indexed: 10/27/2022]
Abstract
The effects of oral delivery of exenatide or pramlintide acetate in dodecyl maltoside (DDM) on energy balance and glycemic control in insulin-resistant obese db/db mice are enhanced when given in combination with [D-Leu-4]-OB3. To examine the anti-hyperglycemic influence of [D-Leu-4]-OB3 in a non-obese insulin-deficient animal model, we compared the effects of metformin (200mg/kg) and [D-Leu-4]-OB3 (40 mg/kg) on energy balance and glycemic control in streptozotocin (STZ)-induced diabetic male Swiss Webster (SW) mice. Diabetic mice were given insulin (Levemir(®), sc) alone, or in combination with metformin or [D-Leu-4]-OB3 orally in DDM, for 14 days. Body weight and food and water intake were measured daily. Fasting blood glucose levels were determined every other day. Serum C-peptide was measured by ELISA. Diabetic mice receiving insulin alone for 14 days gained significantly more weight than DDM-treated control mice, or mice given insulin in combination with metformin or [D-Leu-4]-OB3. The weight gain seen in mice given insulin alone was accompanied by significant increases in both food and water intake. Mice treated with insulin in combination with metformin or [D-Leu-4]-OB3, consumed significantly less food and water. Blood glucose levels in STZ-treated mice receiving insulin alone were reduced to 65.3% of initial levels, while mice receiving insulin with metformin or [D-Leu-4]-OB3 were reduced to 44.5% and 38.9%, respectively. Our results indicate that [D-Leu-4]-OB3 is as effective as metformin in preventing the body weight gain associated with insulin therapy, and on a molar basis, that the efficacy of [D-Leu-4]-OB3 as an insulin sensitizer may equal or surpass that of metformin.
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Affiliation(s)
- Zachary M Novakovic
- Department of Medicine, Division of Endocrinology and Metabolism, Albany Medical College, Albany, NY 12208, USA
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Fang F, Liu GC, Kim C, Yassa R, Zhou J, Scholey JW. Adiponectin attenuates angiotensin II-induced oxidative stress in renal tubular cells through AMPK and cAMP-Epac signal transduction pathways. Am J Physiol Renal Physiol 2013; 304:F1366-74. [PMID: 23535586 DOI: 10.1152/ajprenal.00137.2012] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Obesity is a risk factor for chronic kidney disease (CKD) progression. Circulating levels of adiponectin, an adipokine, decrease with obesity and play a protective role in the cardiovascular system. We hypothesized that adiponectin might also protect the kidney. Because activation of the renin-angiotensin system (RAS) is a contributor to CKD progression, we tested our hypothesis by studying the interactions between adiponectin and angiotensin II (ANG II) in renal tubular cells. Primary human renal proximal tubule cells expressed both adiponectin receptor 1 and 2 (adipoR1 and R2). ANG II-induced NADPH oxidase activation and oxidative stress were attenuated by adiponectin and dependent on adipoR1. Activation of AMPK with 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) mimicked, while inhibition of AMPK with compound C abrogated, the effect of adiponectin on ANG II-induced activation of NADPH oxidase. Similarly, the effect of adiponectin was recapitulated by the stable cAMP analogs 4-chlorophenylthio (pCPT)-cAMP and dibutyryl (db)-cAMP and blocked by the adenylate cyclase inhibitor SQ22536. Adiponectin did not activate PKA in renal tubular cells, and the specific PKA inhibitor myristoylated PKI (14-22) amide failed to block the inhibitory effect of adiponectin on ANG II-induced NADPH oxidase activation. In contrast, the specific Epac activator 8-(4-chlorophenylthio)-2'-O-methyl (8-CPT-2-O-Me)-cAMP blocked ANG II-induced activation of NADPH oxidase, an effect that was reversed by coincubation with the AMPK inhibitor compound C. Finally, adiponectin attenuated ANG II-induced NF-κB activation and fibronectin protein expression. These in vitro findings support the hypothesis that adiponectin may attenuate the deleterious effects of ANG II in the kidney and play a protective role in CKD.
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Affiliation(s)
- Fei Fang
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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Kim MY, Lim JH, Youn HH, Hong YA, Yang KS, Park HS, Chung S, Ko SH, Shin SJ, Choi BS, Kim HW, Kim YS, Lee JH, Chang YS, Park CW. Resveratrol prevents renal lipotoxicity and inhibits mesangial cell glucotoxicity in a manner dependent on the AMPK-SIRT1-PGC1α axis in db/db mice. Diabetologia 2013; 56:204-17. [PMID: 23090186 DOI: 10.1007/s00125-012-2747-2] [Citation(s) in RCA: 232] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 09/03/2012] [Indexed: 12/14/2022]
Abstract
AIMS/HYPOTHESIS Many of the effects of resveratrol are consistent with the activation of AMP-activated protein kinase (AMPK), silent information regulator T1 (SIRT1) and peroxisome proliferator-activated receptor (PPAR)γ co-activator 1α (PGC-1α), which play key roles in the regulation of lipid and glucose homeostasis, and in the control of oxidative stress. We investigated whether resveratrol has protective effects on the kidney in type 2 diabetes. METHODS Four groups of male C57BLKS/J db/m and db/db mice were used in this study. Resveratrol was administered via gavage to diabetic and non-diabetic mice, starting at 8 weeks of age, for 12 weeks. RESULTS The db/db mice treated with resveratrol had decreased albuminuria. Resveratrol ameliorated glomerular matrix expansion and inflammation. Resveratrol also lowered the NEFA and triacylglycerol content of the kidney, and this action was related to increases in the phosphorylation of AMPK and the activation of SIRT1-PGC-1α signalling and of the key downstream effectors, the PPARα-oestrogen-related receptor (ERR)-1α-sterol regulatory element-binding protein 1 (SREBP1). Furthermore, resveratrol decreased the activity of phosphatidylinositol-3 kinase (PI3K)-Akt phosphorylation and class O forkhead box (FOXO)3a phosphorylation, which resulted in a decrease in B cell leukaemia/lymphoma 2 (BCL-2)-associated X protein (BAX) and increases in BCL-2, superoxide dismutase (SOD)1 and SOD2 production. Consequently, resveratrol reversed the increase in renal apoptotic cells and oxidative stress, as reflected by renal 8-hydroxy-deoxyguanosine (8-OH-dG), urinary 8-OH-dG and isoprostane concentrations. Resveratrol prevented high-glucose-induced oxidative stress and apoptosis in cultured mesangial cells through the phosphorylation of AMPK and activation of SIRT1-PGC-1α signalling and the downstream effectors, PPARα-ERR-1α-SREBP1. CONCLUSIONS/INTERPRETATION The results suggest that resveratrol prevents diabetic nephropathy in db/db mice by the phosphorylation of AMPK and activation of SIRT1-PGC-1α signalling, which appear to prevent lipotoxicity-related apoptosis and oxidative stress in the kidney.
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Affiliation(s)
- M Y Kim
- Department of Internal Medicine, Seoul St Mary's Hospital, The Catholic University of Korea, #505, Banpo-Dong, Seocho-Ku, Seoul 137-040, Republic of Korea
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Hsu Y, Cheng C, Chen Y, Chen T, Sue Y, Tsai W, Chen C. Long-term leptin treatment exerts a pro-apoptotic effect on renal tubular cells via prostaglandin E2 augmentation. Eur J Pharmacol 2012; 689:65-71. [DOI: 10.1016/j.ejphar.2012.06.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 06/01/2012] [Accepted: 06/08/2012] [Indexed: 01/01/2023]
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Tang J, Yan H, Zhuang S. Inflammation and oxidative stress in obesity-related glomerulopathy. Int J Nephrol 2012; 2012:608397. [PMID: 22567283 DOI: 10.1155/2012/608397] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 02/06/2012] [Indexed: 01/17/2023] Open
Abstract
Obesity-related glomerulopathy is an increasing cause of end-stage renal disease. Obesity has been considered a state of chronic low-grade systemic inflammation and chronic oxidative stress. Augmented inflammation in adipose and kidney tissues promotes the progression of kidney damage in obesity. Adipose tissue, which is accumulated in obesity, is a key endocrine organ that produces multiple biologically active molecules, including leptin, adiponectin, resistin, that affect inflammation, and subsequent deregulation of cell function in renal glomeruli that leads to pathological changes. Oxidative stress is also associated with obesity-related renal diseases and may trigger the initiation or progression of renal damage in obesity. In this paper, we focus on inflammation and oxidative stress in the progression of obesity-related glomerulopathy and possible interventions to prevent kidney injury in obesity.
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Alcazar MAA, Boehler E, Rother E, Amann K, Vohlen C, von Hörsten S, Plank C, Dötsch J. Early postnatal hyperalimentation impairs renal function via SOCS-3 mediated renal postreceptor leptin resistance. Endocrinology 2012; 153:1397-410. [PMID: 22253420 DOI: 10.1210/en.2011-1670] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Early postnatal hyperalimentation has long-term implications for obesity and developing renal disease. Suppressor of cytokine signaling (SOCS) 3 inhibits phosphorylation of signal transducer and activator of transcription (STAT) 3 and ERK1/2 and thereby plays a pivotal role in mediating leptin resistance. In addition, SOCS-3 is induced by both leptin and inflammatory cytokines. However, little is known about the intrinsic-renal leptin synthesis and function. Therefore, this study aimed to elucidate the implications of early postnatal hyperalimentation on renal function and on the intrinsic-renal leptin signaling. Early postnatal hyperalimentation in Wistar rats during lactation was induced by litter size reduction at birth (LSR) either to LSR10 or LSR6, compared with home cage control male rats. Assessment of renal function at postnatal day 70 revealed decreased glomerular filtration rate and proteinuria after LSR6. In line with this impairment of renal function, renal inflammation and expression as well as deposition of extracellular matrix molecules, such as collagen I, were increased. Furthermore, renal expression of leptin and IL-6 was up-regulated subsequent to LSR6. Interestingly, the phosphorylation of Stat3 and ERK1/2 in the kidney, however, was decreased after LSR6, indicating postreceptor leptin resistance. In accordance, neuropeptide Y (NPY) gene expression was down-regulated; moreover, SOCS-3 protein expression, a mediator of postreceptor leptin resistance, was strongly elevated and colocalized with NPY. Thus, our findings not only demonstrate impaired renal function and profibrotic processes but also provide compelling evidence of a SOCS-3-mediated intrinsic renal leptin resistance and concomitant up-regulated NPY expression as an underlying mechanism.
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Zhang Y, Wang Z, Zhao Y, Zhao M, Wang S, Hua Z, Zhang J. The plasma 5'-AMP acts as a potential upstream regulator of hyperglycemia in type 2 diabetic mice. Am J Physiol Endocrinol Metab 2012; 302:E325-33. [PMID: 22068600 DOI: 10.1152/ajpendo.00424.2011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Increased plasma free fatty acid (FFA) level is a hallmark of type 2 diabetes. However, the underlying molecular basis for FFA-caused hyperglycemia remains unclear. Here we identified plasma 5'-adenosine monophosphate (pAMP) markedly elevated in the plasma of type 2 diabetic mice. High levels of FFAs induced damage in vein endothelial cells and contributed to an increase in pAMP. Administration of synthetic 5'-AMP caused hyperglycemia and impaired insulin action in lean wild-type mice. 5'-AMP elevated blood glucose in mice deficient in adenosine receptors with equal efficiency as wild-type mice. The function of pAMP was initiated by the elevation of cellular adenosine levels, directly stimulating G-6-Pase enzyme activity, attenuating insulin-dependent GLUT4 translocation in skeletal muscle, and displaying a rapid and steep increase in blood glucose and a decrease in hepatic glycogen level. It was followed by an increase in the gene expression of hepatic Foxo1 and its targeting gene Pepck and G6Pase, which was similar to diabetic phenotype in db/db mice. Our results suggest that pAMP is a potential upstream regulator of hyperglycemia in type 2 diabetes.
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MESH Headings
- Adenosine/metabolism
- Adenosine Monophosphate/blood
- Adenosine Monophosphate/chemistry
- Adenosine Monophosphate/metabolism
- Animals
- Cells, Cultured
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Fatty Acids, Nonesterified/adverse effects
- Fatty Acids, Nonesterified/blood
- Female
- Glycogenolysis
- Human Umbilical Vein Endothelial Cells/enzymology
- Human Umbilical Vein Endothelial Cells/metabolism
- Human Umbilical Vein Endothelial Cells/pathology
- Humans
- Hyperglycemia/etiology
- Insulin Resistance
- Liver/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Mutant Strains
- Muscle, Skeletal/metabolism
- Necrosis
- Protein Isoforms/genetics
- Receptors, Purinergic P1/genetics
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Affiliation(s)
- Ying Zhang
- Center for Molecular Metabolism, Nanjing University of Science and Technology, Nanjing, China
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Leung JCK, Chan LYY, Lam MF, Tang SCW, Chow CW, Lim AI, Lai KN. The role of leptin and its short-form receptor in inflammation in db/db mice infused with peritoneal dialysis fluid. Nephrol Dial Transplant 2012; 27:3119-29. [PMID: 22287654 DOI: 10.1093/ndt/gfr774] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND In peritoneal dialysis (PD), the peritoneal membrane exhibits structural and functional changes following continuous exposure to the non-physiological peritoneal dialysis fluid (PDF). In this study, we examined the effect of PDF on peritoneal adipose tissue in a diabetic milieu. METHODS Six-week-old db/db mice and their non-diabetic littermates (db/m) were subjected to uninephrectomy. All animals then received intra-abdominal infusion of lactated Ringer's solution (Ringer) or 1.5% glucose-containing PDF (Dianeal) twice daily. Mice were sacrificed 4 weeks later. Parietal and visceral adipose tissues were harvested for examining gene and protein expression of adiponectin, leptin, monocyte chemotactic protein-1, vascular endothelial growth factor, tumor necrosis factor alpha (TNF-α), transforming growth factor beta and interleukin 6 (IL-6). Expression of TNF-α and F4/80+ macrophage accumulation in adipose tissues was assessed by immunohistochemical staining. Modulation of leptin synthesis and leptin receptors expression and the relevant signaling pathways were also determined by quantitative reverse transcription-polymerase chain reaction, immunoblotting or enzyme-linked immunosorbent assay. RESULTS Compared to Ringer infusion, Dianeal infusion significantly increased serum leptin but decreased adiponectin in db/db mice. Increased expression of leptin, TNF-α and IL-6 was observed in visceral but not in parietal adipose tissue. Dianeal infusion also increased F4/80+ macrophage accumulation and enhanced the expression of pro-inflammatory cytokines including IL-6 and TNF-α in the visceral adipose tissue. Compared to db/m mice, infusion with Dianeal exhibited a more deleterious effect on db/db mice, characterized by an upregulation of short-form leptin receptor ObRa and activation of the mitogen-activated protein kinase signaling pathway. CONCLUSION In conclusion, PD-induced hyperleptinemia amplifies the inflammatory response of adipose tissue through short-form leptin receptor when the long-form isotype is defective.
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Affiliation(s)
- Joseph C K Leung
- Department of Medicine, Queen Mary Hospital, University of Hong Kong, Pokfulam, Hong Kong.
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Yim HE, Ha KS, Bae IS, Yoo KH, Hong YS, Lee JW. Postnatal early overnutrition dysregulates the intrarenal renin-angiotensin system and extracellular matrix-linked molecules in juvenile male rats. J Nutr Biochem 2011; 23:937-45. [PMID: 21752621 DOI: 10.1016/j.jnutbio.2011.04.020] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Revised: 01/17/2011] [Accepted: 04/20/2011] [Indexed: 12/22/2022]
Abstract
Overnutrition during the perinatal period has been associated with susceptibility to obesity and related comorbidities. We examined the effects of postnatal early overnutrition on the development of juvenile obesity and the associated renal pathophysiological changes. Three or 10 pups per mother from rat pup litters were assigned to either the overnutrition or control groups during the first 21 days of life. The effects of overfeeding were measured at 28 days. The smaller male litter pups were heavier than the controls between 4 and 28 days after birth (P<.05). By 28 days of age, the kidney weight per body weight ratio decreased in the small litter group (P<.05). Circulating leptin levels increased in the small litter rats (P<.05). Overnutrition had no effect on renal cell proliferation, apoptosis, macrophages and glomerulosclerosis. In the immunoblots and immunohistochemistry, renin and angiotensin II type (AT) 2 receptor expression increased in the overfed rats (P<.05). By contrast, the plasminogen activator inhibitor (PAI)-1 and matrix metalloproteinase (MMP)-9 expression decreased in the overnutrition group (P<.05). The AT 1 receptor, tissue inhibitor of MMP-1, monocyte chemoattractant protein-1, tumor necrosis factor-α, osteopontin and adiponectin expression was not changed. Our data showed that postnatal early overfeeding led to hyperleptinemia, juvenile obesity and the acquired reset of renal maturation. Up-regulation of renin and AT2 and down-regulation of PAI-1 and MMP-9 might contribute to abnormal programming of renal growth in rats exposed to postnatal early overnutrition.
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Affiliation(s)
- Hyung Eun Yim
- Department of Pediatrics, College of Medicine, Korea University, Seoul, Korea
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Chen YC, Chen CH, Hsu YH, Chen TH, Sue YM, Cheng CY, Chen TW. Leptin reduces gentamicin-induced apoptosis in rat renal tubular cells via the PI3K-Akt signaling pathway. Eur J Pharmacol 2011; 658:213-8. [DOI: 10.1016/j.ejphar.2011.02.025] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Revised: 01/29/2011] [Accepted: 02/17/2011] [Indexed: 01/08/2023]
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