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Guo F, Yao L, Zhang W, Chen P, Hao R, Huang X, Jiang J, Wu S. The therapeutic mechanism of Yuye decoction on type 2 diabetes mellitus based on network pharmacology and experimental verification. JOURNAL OF ETHNOPHARMACOLOGY 2023; 308:116222. [PMID: 36828194 DOI: 10.1016/j.jep.2023.116222] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/21/2023] [Accepted: 01/28/2023] [Indexed: 06/18/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Yuye decoction (YYD) has been widely used as a folk Chinese herbal formula in clinical treatment of type 2 diabetes mellitus(T2DM) for many years. However, its mechanism is still unclear. AIM OF THE STUDY The aim of this study was to explore the potential mechanism of YYD against T2DM initially by UHPLC-MS/MS combining with network pharmacology, molecular docking techniques and experimental validation. MATERIALS AND METHODS The main ingredients in the water extract of YYD were initially identified using UHPLC-MS/MS analysis. Combined with network pharmacology and molecular docking techniques, the YYD key compounds-core targets-key signaling pathways network was constructed and the binding activity of key components to core targets was validated. The T2DM rat model was induced by Streptozotocin combined with high glucose and high fat diets. The apoptosis cell model of mouse islet β-cell of Min6 was induced by high-glucose and palmitic acid. Histopathological and immunofluorescence satining were used to evaluate pancreatic islet β-cell function and apoptosis in rats. Min6 cell viability and apoptosis ratio were evaluated by CCK-8 and TUNEL staining. The predicted targets and pathways were validated by experiments in vitro and in vivo. RESULTS The 56 compounds from YYD were identified by UHPLC-MS/MS. The potential targets of the above compounds were predicted by online compound target database, among of which 362 targets were associated with T2DM. Protein-protein interaction analysis identified the main targets such as SRC, MAPK1, PIK3R1, AKT1, HRAS and HSP90AA1, which were considered as the therapeutic targets of YYD on against T2DM. Functional enrichment analysis revealed that PI3K/AKT, FoxO and apoptosis signaling pathways were significantly enriched. Molecular docking results showed that compounds of monolinolein, neomangiferin, mangiferin, pelargonidin-3-O-glucoside and acacetin from YYD had high binding activities to PIK3R1, AKT1, Sirt1 and FoxO1. Therefore, PI3K/AKT1, Sirt1/FoxO1 and apoptotic signaling pathways were considered as predicted targets for experimental validation study. Animal experiments showed that YYD reduced blood glucose levels, improved pancreatic dysfunction and pancreatic islet β-cells apoptosis in T2DM rats which contributed to the activation of AKT1 and FoxO1 and their related signaling molecules. These results were confirmed in Min6 cell model induced by high-glucose and palmitic acid. CONCLUSIONS In summary, this study systematically visualized the possible therapeutic effects and mechanisms of YYD on T2DM through the network pharmacology approach and experimental study. The results indicated that YYD could prevent pancreatic islet dysfunction and reverse islet of β-cells apoptosis possibly via PI3K/AKT1, Sirt1/FoxO1 signaling pathways.
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Affiliation(s)
- Feng Guo
- College of Traditional Chinese Medicine, Xinjiang Medical University, Urumqi, 830017, China
| | - Lan Yao
- College of Traditional Chinese Medicine, Xinjiang Medical University, Urumqi, 830017, China.
| | - Wenxiang Zhang
- College of Traditional Chinese Medicine, Xinjiang Medical University, Urumqi, 830017, China
| | - Pengde Chen
- College of Traditional Chinese Medicine, Xinjiang Medical University, Urumqi, 830017, China
| | - Rui Hao
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing, 210046, China
| | - Xuelian Huang
- College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, 518060, China
| | - Jie Jiang
- College of Traditional Chinese Medicine, Xinjiang Medical University, Urumqi, 830017, China
| | - Siyu Wu
- College of Traditional Chinese Medicine, Xinjiang Medical University, Urumqi, 830017, China
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Bauzá-Thorbrügge M, Banke E, Chanclón B, Peris E, Wu Y, Musovic S, Jönsson C, Strålfors P, Rorsman P, Olofsson CS, Asterholm IW. Adipocyte-specific ablation of the Ca 2+ pump SERCA2 impairs whole-body metabolic function and reveals the diverse metabolic flexibility of white and brown adipose tissue. Mol Metab 2022; 63:101535. [PMID: 35760318 PMCID: PMC9287368 DOI: 10.1016/j.molmet.2022.101535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) transports Ca2+ from the cytosol into the ER and is essential for appropriate regulation of intracellular Ca2+ homeostasis. The objective of this study was to test the hypothesis that SERCA pumps are involved in the regulation of white adipocyte hormone secretion and other aspects of adipose tissue function and that this control is disturbed in obesity-induced type-2 diabetes. METHODS SERCA expression was measured in isolated human and mouse adipocytes as well as in whole mouse adipose tissue by Western blot and RT-qPCR. To test the significance of SERCA2 in adipocyte functionality and whole-body metabolism, we generated adipocyte-specific SERCA2 knockout mice. The mice were metabolically phenotyped by glucose tolerance and tracer studies, histological analyses, measurements of glucose-stimulated insulin release in isolated islets, and gene/protein expression analyses. We also tested the effect of pharmacological SERCA inhibition and genetic SERCA2 ablation in cultured adipocytes. Intracellular and mitochondrial Ca2+ levels were recorded with dual-wavelength ratio imaging and mitochondrial function was assessed by Seahorse technology. RESULTS We demonstrate that SERCA2 is downregulated in white adipocytes from patients with obesity and type-2 diabetes as well as in adipocytes from diet-induced obese mice. SERCA2-ablated adipocytes display disturbed Ca2+ homeostasis associated with upregulated ER stress markers and impaired hormone release. These adipocyte alterations are linked to mild lipodystrophy, reduced adiponectin levels, and impaired glucose tolerance. Interestingly, adipocyte-specific SERCA2 ablation leads to increased glucose uptake in white adipose tissue while glucose uptake is reduced in brown adipose tissue. This dichotomous effect on glucose uptake is due to differently regulated mitochondrial function. In white adipocytes, SERCA2 deficiency triggers an adaptive increase in FGF21, increased mitochondrial UCP1 levels, and increased oxygen consumption rate (OCR). In contrast, brown SERCA2 null adipocytes display reduced OCR despite increased mitochondrial content and UCP1 levels compared to wild type controls. CONCLUSIONS Our data suggest causal links between reduced white adipocyte SERCA2 levels, deranged adipocyte Ca2+ homeostasis, adipose tissue dysfunction and type-2 diabetes.
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Affiliation(s)
- Marco Bauzá-Thorbrügge
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30 Göteborg, Sweden.
| | - Elin Banke
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30 Göteborg, Sweden.
| | - Belén Chanclón
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30 Göteborg, Sweden.
| | - Eduard Peris
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30 Göteborg, Sweden.
| | - Yanling Wu
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30 Göteborg, Sweden.
| | - Saliha Musovic
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30 Göteborg, Sweden.
| | - Cecilia Jönsson
- Department of Biomedical and Clinical Sciences, Linköping University, SE-58185 Linköping, Sweden.
| | - Peter Strålfors
- Department of Biomedical and Clinical Sciences, Linköping University, SE-58185 Linköping, Sweden.
| | - Patrik Rorsman
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30 Göteborg, Sweden; Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX4 7LE, UK.
| | - Charlotta S Olofsson
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30 Göteborg, Sweden.
| | - Ingrid Wernstedt Asterholm
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30 Göteborg, Sweden.
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Activating BK channels ameliorates vascular smooth muscle calcification through Akt signaling. Acta Pharmacol Sin 2022; 43:624-633. [PMID: 34163023 PMCID: PMC8888620 DOI: 10.1038/s41401-021-00704-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 05/23/2021] [Indexed: 02/06/2023] Open
Abstract
Vascular calcification (VC) is characterized by pathological depositions of calcium and phosphate in the arteries and veins via an active cell-regulated process, in which vascular smooth muscle cells (VSMCs) transform into osteoblast/chondrocyte-like cells as in bone formation. VC is associated with significant morbidity and mortality in chronic kidney disease (CKD) and cardiovascular disease, but the underlying mechanisms remain unclear. In this study we investigated the role of large-conductance calcium-activated potassium (BK) channels in 3 experimental VC models. VC was induced in vascular smooth muscle cells (VSMCs) by β-glycerophosphate (β-GP), or in rats by subtotal nephrectomy, or in mice by high-dosage vitamin D3. We showed that the expression of BK channels in the artery of CKD rats with VC and in β-GP-treated VSMCs was significantly decreased, which was functionally confirmed by patch-clamp recording. In β-GP-treated VSMCs, BK channel opener NS1619 (20 μM) significantly alleviated VC by decreasing calcium content and alkaline phosphatase activity. Furthermore, NS1619 decreased mRNA expression of ostoegenic genes OCN and OPN, as well as Runx2 (a key transcription factor involved in preosteoblast to osteoblast differentiation), and increased the expression of α-SMA protein, whereas BK channel inhibitor paxilline (10 μM) caused the opposite effects. In primary cultured VSMCs from BK-/- mice, BK deficiency aggravated calcification as did BK channel inhibitor in normal VSMCs. Moreover, calcification was more severe in thoracic aorta rings of BK-/- mice than in those of wild-type littermates. Administration of BK channel activator BMS191011 (10 mg· kg-1 ·d-1) in high-dosage vitamin D3-treated mice significantly ameliorated calcification. Finally, co-treatment with Akt inhibitor MK2206 (1 μM) or FoxO1 inhibitor AS1842856 (3 μM) in calcified VSMCs abrogated the effects of BK channel opener NS1619. Taken together, activation of BK channels ameliorates VC via Akt/FoxO1 signaling pathways. Strategies to activate BK channels and/or enhance BK channel expression may offer therapeutic avenues to control VC.
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Roberts BS, Yang CQ, Neher SB. Characterization of lipoprotein lipase storage vesicles in 3T3-L1 adipocytes. J Cell Sci 2022; 135:jcs258734. [PMID: 34382637 PMCID: PMC8403984 DOI: 10.1242/jcs.258734] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/10/2021] [Indexed: 12/12/2022] Open
Abstract
Lipoprotein lipase (LPL) is a secreted triglyceride lipase involved in the clearance of very-low-density lipoproteins and chylomicrons from circulation. LPL is expressed primarily in adipose and muscle tissues and transported to the capillary lumen. LPL secretion is regulated by insulin in adipose tissue; however, few studies have examined the regulatory and trafficking steps involved in secretion. Here, we describe the intracellular localization and insulin-dependent trafficking of LPL in 3T3-L1 adipocytes. We compared LPL trafficking to the better characterized trafficking pathways taken by leptin and GLUT4 (also known as SLC2A4). We show that the LPL trafficking pathway shares some characteristics of these other pathways, but that LPL subcellular localization and trafficking are distinct from those of GLUT4 and leptin. LPL secretion occurs slowly in response to insulin and rapidly in response to the Ca2+ ionophore ionomycin. This regulated trafficking is dependent on Golgi protein kinase D and the ADP-ribosylation factor GTPase ARF1. Together, these data give support to a new trafficking pathway for soluble cargo that is active in adipocytes.
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Affiliation(s)
| | | | - Saskia B. Neher
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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5
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Nguyen J, Patel A, Gensburg A, Bokhari R, Lamar P, Edwards J. Diabetogenic and Obesogenic Effects of Cadmium in Db/Db Mice and Rats at a Clinically Relevant Level of Exposure. TOXICS 2022; 10:toxics10030107. [PMID: 35324731 PMCID: PMC8949435 DOI: 10.3390/toxics10030107] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/11/2022] [Accepted: 02/21/2022] [Indexed: 12/16/2022]
Abstract
Studies show an association between cadmium (Cd) exposure and prediabetes or type II diabetes mellitus. We have previously reported that Cd causes decreased levels of serum leptin in rats following 12 weeks of daily Cd dosing (0.6 mg/kg/b.w./day). Since leptin plays an important role in metabolism, we examined the effects of Cd on rats and db/db mice, which are deficient in leptin receptor activity. We gave rats and mice daily subcutaneous injections of saline (control) or CdCl2 at a dose of 0.6 mg/kg of Cd for 2 weeks, followed by 2 weeks of no dosing. At the end of the 4-week study, exposure to Cd resulted in a more rapid increase in blood glucose levels following an oral glucose tolerance test in db/db vs. lean mice. During the two weeks of no Cd dosing, individual rat bodyweight gain was greater (p ≤ 0.05) in Cd-treated animals. At this time point, the combined epididymal and retroperitoneal fat pad weight was significantly greater (p ≤ 0.05) in the Cd-treated lean mice compared to saline-treated controls. Although this pilot study had relatively low N values (4 per treatment group for mice and 6 for rats) the results show that clinically relevant levels of Cd exposure resulted in diabetogenic as well as obesogenic effects.
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Affiliation(s)
- Jessica Nguyen
- Chicago College of Pharmacy, Midwestern University, Downers Grove, IL 60515, USA;
| | - Arjun Patel
- Arizona College of Osteopathic Medicine, Midwestern University, Glendale, AZ 85308, USA;
| | - Andrew Gensburg
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (A.G.); (R.B.)
| | - Rehman Bokhari
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (A.G.); (R.B.)
| | - Peter Lamar
- College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA;
| | - Joshua Edwards
- College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA;
- Correspondence: ; Tel.: +1-(630)-515-7417
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Tyagi S, Shekhar N, Thakur AK. Protective Role of Capsaicin in Neurological Disorders: An Overview. Neurochem Res 2022; 47:1513-1531. [PMID: 35150419 DOI: 10.1007/s11064-022-03549-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 02/04/2022] [Accepted: 02/05/2022] [Indexed: 11/24/2022]
Abstract
Different pathological conditions that begin with slow and progressive deformations, cause irreversible affliction by producing loss of neurons and synapses. Commonly it is referred to as 'protein misfolding' diseases or proteinopathies and comprises the latest definition of neurological disorders (ND). Protein misfolding dynamics, proteasomal dysfunction, aggregation, defective degradation, oxidative stress, free radical formation, mitochondrial dysfunctions, impaired bioenergetics, DNA damage, neuronal Golgi apparatus fragmentation, axonal transport disruption, Neurotrophins (NTFs) dysfunction, neuroinflammatory or neuroimmune processes, and neurohumoral changes are the several mechanisms that embark the pathogenesis of ND. Capsaicin (8-Methyl-N-vanillyl-6-nonenamide) one of the major phenolic components in chili peppers (Capsicum) distinctively triggers the unmyelinated C-fiber and acts on Transient Receptor Potential Vanilloid-1, which is a Ca2+ permeable, non-selective cation channel. Several studies have shown the neuroprotective role of capsaicin against oxidative damage, behavioral impairment, with 6-hydroxydopamine (6-OHDA) induced Parkinson's disease, pentylenetetrazol-induced seizures, global cerebral ischemia, and streptozotocin-induced Alzheimer's disease. Based on these lines of evidence, capsaicin can be considered as a potential constituent to develop suitable neuro-pharmacotherapeutics for the management and treatment of ND. Furthermore, exploring newer horizons and carrying out proper clinical trials would help to bring out the promising effects of capsaicin to be recommended as a neuroprotectant.
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Affiliation(s)
- Sakshi Tyagi
- Neuropharmacology Research Laboratory, School of Pharmaceutical Sciences, Delhi Pharmaceutical Sciences and Research University, New Delhi, 110 017, India
| | - Nikhila Shekhar
- Neuropharmacology Research Laboratory, School of Pharmaceutical Sciences, Delhi Pharmaceutical Sciences and Research University, New Delhi, 110 017, India
| | - Ajit Kumar Thakur
- Neuropharmacology Research Laboratory, School of Pharmaceutical Sciences, Delhi Pharmaceutical Sciences and Research University, New Delhi, 110 017, India.
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7
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Ren J, Cheng Y, Wen X, Liu P, Zhao F, Xin F, Wang M, Huang H, Wang W. BK Ca channel participates in insulin-induced lipid deposition in adipocytes by increasing intracellular calcium. J Cell Physiol 2021; 236:5818-5831. [PMID: 33432604 DOI: 10.1002/jcp.30266] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 12/21/2022]
Abstract
Storing energy in the form of triglyceride (TG) is one of the basic functions of adipose tissue. Large-conductance calcium-activated potassium channels (BKCa channels) are expressed in adipose tissue and adipocyte-specific BKCa deficiency resists obesity in mice, but the role of BKCa channels in lipid deposition and the underlying mechanisms have not been elucidated. In the present study, we generated BKCa knockout (KO) rats and performed a transcriptome analysis of adipose tissue. We found that the phosphoinositide 3-kinase (PI3K)-protein kinase B (Akt) signaling pathway, which is important for lipid deposition, exhibited the most notable reduction among various signaling pathways in BKCa KO rats compared to wild-type rats. Insulin-induced TG deposition, glucose uptake, and Akt (Ser473) phosphorylation were significantly reduced in cultured adipocytes differentiated from adipose-derived stem cells of BKCa KO rats. Furthermore, we found that the insulin-induced increase of intracellular calcium resulting from extracellular calcium influx was significantly impaired in BKCa KO adipocytes. Finally, insulin activated BKCa currents through PI3K, which was independent of Akt and intracellular calcium. The results of this study suggested that BKCa channels participate in the insulin signaling pathway and promote TG deposition by increasing extracellular calcium influx in adipocytes.
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Affiliation(s)
- Jie Ren
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Yuan Cheng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Xinxin Wen
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Ping Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Beijing Lab for Cardiovascular Precision Medicine, Beijing, China
| | - Feng Zhao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Fang Xin
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Beijing Lab for Cardiovascular Precision Medicine, Beijing, China
| | - Meili Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Haixia Huang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Beijing Lab for Cardiovascular Precision Medicine, Beijing, China.,Beijing Key Laboratory of Metabolic Disorders Related Cardiovascular Diseases, Capital Medical University, Beijing, China
| | - Wei Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China.,Beijing Lab for Cardiovascular Precision Medicine, Beijing, China
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Musovic S, Shrestha MM, Komai AM, Olofsson CS. Resistin is co-secreted with adiponectin in white mouse adipocytes. Biochem Biophys Res Commun 2020; 534:707-713. [PMID: 33261886 DOI: 10.1016/j.bbrc.2020.11.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 11/04/2020] [Indexed: 12/19/2022]
Abstract
In the current work we have investigated the cellular and molecular regulation of resistin secretion in cultured and primary mouse adipocytes. Resistin is an adipose tissue hormone proposed to contribute to metabolic disease. In rodents, resistin is secreted from white adipocytes whereas it is in humans synthesised and released from other cell types within white adipose tissue. The metabolic importance of resistin has been studied in both mouse and man, but the regulation of its release remains poorly investigated. Here we define that, in mouse adipocytes, resistin secretion is triggered by an intracellular elevation of cAMP and/or Ca2+. Resistin release is stimulated via activation of beta 3 adrenergic receptors (β3ARs) and the downstream signalling protein exchange protein activated by cAMP (Epac). The secretion of resistin is markedly abrogated in adipocytes isolated from obese and diabetic mice. Immunocytochemical staining demonstrates a significant overlap between signals for resistin and the adipocyte hormone adiponectin. Our data propose that resistin and adiponectin are contained within the same vesicles in mouse adipocytes and that the two hormones are co-secreted in response to the same exocytosis-triggering signals.
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Affiliation(s)
- Saliha Musovic
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Man Mohan Shrestha
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Ali M Komai
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Charlotta S Olofsson
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden.
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Hu J, Li X, Judd RL, Easley CJ. Rapid lipolytic oscillations in ex vivo adipose tissue explants revealed through microfluidic droplet sampling at high temporal resolution. LAB ON A CHIP 2020; 20:1503-1512. [PMID: 32239045 PMCID: PMC7380261 DOI: 10.1039/d0lc00103a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Our understanding of adipose tissue biology has steadily evolved. While structural and energy storage functionalities have been in the forefront, a key endocrine role for adipocytes was revealed only over the last few decades. In contrast to the wealth of information on dynamic function of other endocrine tissues, few studies have focused on dynamic adipose tissue function or on tool development toward that end. Here, we apply our unique droplet-based microfluidic devices to culture, perfuse, and sample secretions from primary murine epididymal white adipose tissue (eWAT), and from predifferentiated clusters of 3T3-L1 adipocytes. Through automated control, oil-segmented aqueous droplets (∼2.6 nL) were sampled from tissue or cells at 3.5 second temporal resolution (including sample and reference droplets), with integrated enzyme assays enabling real-time quantification of glycerol (down to 1.9 fmol per droplet). This high resolution revealed previously unreported oscillations in secreted glycerol at frequencies of 0.2 to 2.0 min-1 (∼30-300 s periods) present in the primary tissue but not in clustered cells. Low-level bursts (∼50 fmol) released in basal conditions were contrasted with larger bursts (∼300 fmol) during stimulation. Further, both fold changes and burst magnitudes were decreased in eWAT of aged and obese mice. These results, combined with immunostaining and photobleaching analyses, suggest that gap-junctional coupling or nerve cell innervation within the intact ex vivo tissue explants play important roles in this apparent tissue-level, lipolytic synchronization. High-resolution, quantitative sampling by droplet microfluidics thus permitted unique biological information to be observed, giving an analytical framework poised for future studies of dynamic oscillatory function of adipose and other tissues.
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Affiliation(s)
- Juan Hu
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, USA.
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10
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Ho Y, Wang SH, Chen YR, Li ZL, Chin YT, Yang YCSH, Wu YH, Su KW, Chu HR, Chiu HC, Crawford DR, Shih YJ, Grasso P, Tang HY, Lin HY, Davis PJ, Whang-Peng J, Wang K. Leptin-derived peptides block leptin-induced proliferation by reducing expression of pro-inflammatory genes in hepatocellular carcinoma cells. Food Chem Toxicol 2019; 133:110808. [PMID: 31499123 DOI: 10.1016/j.fct.2019.110808] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 09/02/2019] [Accepted: 09/05/2019] [Indexed: 02/05/2023]
Abstract
The obesity-regulated gene, leptin, is essential for diet. Leptin resistance causes obesity and related diseases. Certain types of diet are able to decrease leptin resistance. However, leptin has been shown to be correlated with inflammation and stimulate proliferation of various cancers. Two synthetic leptin derivatives (mimetics), OB3 and [D-Leu-4]-OB3, show more effective than leptin in reducing obesity and diabetes in mouse models. OB3 inhibits leptin-induced proliferation in ovarian cancer cells. However, effects of these mimetics in hepatocellular carcinoma (HCC) have not been investigated. In the present study, we examined the effects of OB3 and [D-Leu-4]-OB3 on cell proliferation and gene expressions in human HCC cell cultures. In contrast to what was reported for leptin, OB3 and [D-Leu-4]-OB3 reduced cell proliferation in hepatomas. Both OB3 and [D-Leu-4]-OB3 stimulated expression of pro-apoptotic genes. Both compounds also inhibited expressions of pro-inflammatory, proliferative and metastatic genes and PD-L1 expression. In combination with leptin, OB3 inhibited leptin-induced cell proliferation and expressions of pro-inflammation-, and proliferation-related genes. Furthermore, the OB3 peptide inhibited phosphoinositide 3-kinase (PI3K) activation which is essential for leptin-induced proliferation in HCC. These results indicate that OB3 and [D-Leu-4]-OB3 may have the potential to reduce leptin-related inflammation and proliferation in HCC cells.
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Affiliation(s)
- Yih Ho
- School of Pharmacy, Taipei Medical University, Taipei, 11031, Taiwan
| | - Shwu-Huey Wang
- Taipei Cancer Center, Taipei Medical University, Taipei, 11031, Taiwan; Core Facility Center, Department of Research Development, Taipei Medical University, Taipei, 11031, Taiwan
| | - Yi-Ru Chen
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Graduate Institute of Nanomedicine and Medical Engineering, College of Medical Engineering, Taipei Medical University, Taipei, 11031, Taiwan
| | - Zi-Lin Li
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Graduate Institute of Nanomedicine and Medical Engineering, College of Medical Engineering, Taipei Medical University, Taipei, 11031, Taiwan
| | - Yu-Tang Chin
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Cancer Center, Wan Fang Hospital, Taipei Medical University, Taipei, 11031, Taiwan
| | - Yu-Chen S H Yang
- Joint Biobank, Office of Human Research, Taipei Medical University, Taipei, 11031, Taiwan
| | - Yun-Hsuan Wu
- Institute of Sociology, Academia Sinica, Taipei, Taiwan
| | - Kuan-Wei Su
- Department of Dentistry, Hsinchu MacKay Memorial Hospital, Hsinchu City, Taiwan
| | - Hung-Ru Chu
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Graduate Institute of Nanomedicine and Medical Engineering, College of Medical Engineering, Taipei Medical University, Taipei, 11031, Taiwan
| | - Hsien-Chung Chiu
- Department of Periodontology, School of Dentistry, National Defense Medical, Center and Tri-Service General Hospital, Taipei, Taiwan
| | - Dana R Crawford
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY, USA
| | - Ya-Jung Shih
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Graduate Institute of Nanomedicine and Medical Engineering, College of Medical Engineering, Taipei Medical University, Taipei, 11031, Taiwan
| | - Patricia Grasso
- Department of Medicine, Division of Endocrinology and Metabolism, Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, USA
| | - Heng-Yuan Tang
- Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Albany, NY, USA
| | - Hung-Yun Lin
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Cancer Center, Wan Fang Hospital, Taipei Medical University, Taipei, 11031, Taiwan; Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Albany, NY, USA; Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, 11031, Taiwan; TMU Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Traditional Herbal Medicine Research Center of Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan.
| | - Paul J Davis
- Pharmaceutical Research Institute, Albany College of Pharmacy and Health Sciences, Albany, NY, USA; Department of Medicine, Albany Medical College, Albany, NY, USA
| | - Jacqueline Whang-Peng
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Cancer Center, Wan Fang Hospital, Taipei Medical University, Taipei, 11031, Taiwan; Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, 11031, Taiwan
| | - Kuan Wang
- Department of Biochemistry and Molecular Cell Biology, School of Medicine, Taipei Medical University, Taipei, 11031, Taiwan; Graduate Institute of Nanomedicine and Medical Engineering, College of Medical Engineering, Taipei Medical University, Taipei, 11031, Taiwan
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11
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Keuper M. On the role of macrophages in the control of adipocyte energy metabolism. Endocr Connect 2019; 8:R105-R121. [PMID: 31085768 PMCID: PMC6590200 DOI: 10.1530/ec-19-0016] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 05/14/2019] [Indexed: 12/11/2022]
Abstract
The crosstalk between macrophages (MΦ) and adipocytes within white adipose tissue (WAT) influences obesity-associated insulin resistance and other associated metabolic disorders, such as atherosclerosis, hypertension and type 2 diabetes. MΦ infiltration is increased in WAT during obesity, which is linked to decreased mitochondrial content and activity. The mechanistic interplay between MΦ and mitochondrial function of adipocytes is under intense investigation, as MΦ and inflammatory pathways exhibit a pivotal role in the reprogramming of WAT metabolism in physiological responses during cold, fasting and exercise. Thus, the underlying immunometabolic pathways may offer therapeutic targets to correct obesity and metabolic disease. Here, I review the current knowledge on the quantity and the quality of human adipose tissue macrophages (ATMΦ) and their impact on the bioenergetics of human adipocytes. The effects of ATMΦ and their secreted factors on mitochondrial function of white adipocytes are discussed, including recent research on MΦ as part of an immune signaling cascade involved in the 'browning' of WAT, which is defined as the conversion from white, energy-storing adipocytes into brown, energy-dissipating adipocytes.
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Affiliation(s)
- Michaela Keuper
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Correspondence should be addressed to M Keuper:
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12
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Cai R, Tang G, Zhang Q, Yong W, Zhang W, Xiao J, Wei C, He C, Yang G, Pang W. A Novel lnc-RNA, Named lnc-ORA, Is Identified by RNA-Seq Analysis, and Its Knockdown Inhibits Adipogenesis by Regulating the PI3K/AKT/mTOR Signaling Pathway. Cells 2019; 8:cells8050477. [PMID: 31109074 PMCID: PMC6562744 DOI: 10.3390/cells8050477] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/16/2019] [Accepted: 05/16/2019] [Indexed: 12/17/2022] Open
Abstract
Obesity is closely associated with numerous adipogenic regulatory factors, including coding and non-coding genes. Long noncoding RNAs (lncRNAs) play a major role in adipogenesis. However, differential expression profiles of lncRNAs in inguinal white adipose tissue (iWAT) between wild-type (WT) and ob/ob mice, as well as their roles in adipogenesis, are not well understood. Here, a total of 2809 lncRNAs were detected in the iWAT of WT and ob/ob mice by RNA-Sequencing (RNA-Seq), including 248 novel lncRNAs. Of them, 46 lncRNAs were expressed differentially in WT and ob/ob mice and were enriched in adipogenesis signaling pathways as determined by KEGG enrichment analysis, including the PI3K/AKT/mTOR and cytokine-cytokine receptor interaction signaling pathways. Furthermore, we focused on one novel lncRNA, which we named lnc-ORA (obesity-related lncRNA), which had a seven-fold higher expression in ob/ob mice than in WT mice. Knockdown of lnc-ORA inhibited preadipocyte proliferation by decreasing the mRNA and protein expression levels of cell cycle markers. Interestingly, lnc-ORA knockdown inhibited adipocyte differentiation by regulating the PI3K/AKT/mTOR signaling pathway. In summary, these findings contribute to a better understanding of adipogenesis in relation to lncRNAs and provide novel potential therapeutic targets for obesity-related metabolic diseases.
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Affiliation(s)
- Rui Cai
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Guorong Tang
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Que Zhang
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Wenlong Yong
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Wanrong Zhang
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Junying Xiao
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Changsheng Wei
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Chun He
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Gongshe Yang
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - Weijun Pang
- Laboratory of Animal Fat Deposition and Muscle Development, Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling 712100, Shaanxi, China.
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13
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Takaya J, Yamanouchi S, Kino J, Tanabe Y, Kaneko K. A Calcium-Deficient Diet in Dams during Gestation Increases Insulin Resistance in Male Offspring. Nutrients 2018; 10:nu10111745. [PMID: 30428526 PMCID: PMC6266795 DOI: 10.3390/nu10111745] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 11/07/2018] [Accepted: 11/08/2018] [Indexed: 01/09/2023] Open
Abstract
Calcium (Ca) plays an important role in the pathogenesis of insulin resistance syndrome. Osteocalcin (OC), a bone formation biomarker, acts directly on β-cells and increases insulin secretion. We determined the effects of Ca deficiency during pregnancy and/or lactation on insulin resistance in offspring. Female Wistar rats consumed either a Ca-deficient or control diet ad libitum from three weeks preconception to 21 days postparturition. Pups were allowed to nurse their original mothers until weaning. The offspring were fed a control diet beginning at weaning and were killed on day 180. Serum carboxylated OC (Gla-OC) and undercarboxylated OC (Glu-OC), insulin and adipokines in offspring were measured. In males, mean levels of insulin, glucose, and HOMA-IR were higher in the Ca-deficient group than in the control group. In addition, ionized Ca (iCa) was inversely associated with serum Glu-OC and adiponectin in males. In females, mean levels of Glu-OC and Gla-OC in the Ca-deficient group were higher than in the control group. In all offspring, serum leptin levels were correlated with serum insulin levels, and inversely correlated with iCa. In conclusion, maternal Ca restriction during pregnancy and/or lactation influences postnatal offspring Ca metabolism and insulin resistance in a sex-specific manner.
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Affiliation(s)
- Junji Takaya
- Department of Pediatrics, Kansai Medical University, Hirakata 573-1010, Japan.
| | - Sohsaku Yamanouchi
- Department of Pediatrics, Kansai Medical University, Hirakata 573-1010, Japan.
| | - Jiro Kino
- Department of Pediatrics, Kansai Medical University, Hirakata 573-1010, Japan.
| | - Yuko Tanabe
- Department of Pediatrics, Kansai Medical University, Hirakata 573-1010, Japan.
| | - Kazunari Kaneko
- Department of Pediatrics, Kansai Medical University, Hirakata 573-1010, Japan.
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14
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Abstract
High secretion of interleukin (IL)-6 from white adipose tissue may contribute to metabolic complications in obesity. We have recently shown that IL-6-type cytokine signaling in adipocytes is involved in the development of obesity-associated hepatic insulin resistance and steatosis. In addition, we revealed that adipocyte-specific IL-6 signaling ameliorates glucose metabolism in obesity via enhancing insulin secretion. Mechanistically, IL-6 induces the release of free fatty acid (FFA) and leptin from adipocytes thereby affecting liver metabolism and pancreatic β-cell function, respectively. This commentary further discusses the role of adipocyte-specific IL-6-type cytokine signaling in the regulation of FFA and leptin release. In particular, we outline depot-specific differences in IL-6-induced basal release of the two aforementioned factors. Moreover, we provide evidence that insulin's effect on the release of FFA and leptin is adipose depot-dependent. We conclude that adipose depot-specific targeting of the IL-6 signaling pathway may be a novel approach to blunt obesity-associated metabolic complications.
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Affiliation(s)
- Stephan Wueest
- Division of Pediatric Endocrinology and Diabetology, University Children’s Hospital, Zurich, Switzerland
- Children’s Research Center, University Children’s Hospital, Zurich, Switzerland
| | - Daniel Konrad
- Division of Pediatric Endocrinology and Diabetology, University Children’s Hospital, Zurich, Switzerland
- Children’s Research Center, University Children’s Hospital, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
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15
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Marques-Oliveira GH, Silva TM, Lima WG, Valadares HMS, Chaves VE. Insulin as a hormone regulator of the synthesis and release of leptin by white adipose tissue. Peptides 2018; 106:49-58. [PMID: 29953915 DOI: 10.1016/j.peptides.2018.06.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/20/2018] [Accepted: 06/24/2018] [Indexed: 02/09/2023]
Abstract
Leptin and its receptor are widely distributed in several tissues, mainly in white adipose tissue. The serum leptin is highly correlated with body mass index in rodents and humans, being documented that leptin levels reduces in the fasting state and increase during refeeding, similarly to insulin release by pancreatic islets. Insulin appears to increase leptin mRNA and protein expression and its release by adipocytes. Some studies have suggested that insulin acts through the activation of the transcription factors: sterol regulatory element binding protein 1 (SREBP1), CCAAT enhancer binding protein-α (C/EBP-α) and specificity protein 1 (Sp1). Insulin stimulates the release of preformed and newly synthesized leptin by adipocytes through its signaling cascade. Its effects are blocked by inhibitors of the insulin signaling pathway, as well as by inhibitors of protein synthesis and agents that increase the intracellular cAMP. The literature data suggest that chronic hyperinsulinemia increases serum leptin levels in humans and rodents. In this review, we summarized the most updated knowledge on the effects of insulin on serum leptin levels, presenting the cell mechanisms that control leptin synthesis and release by the white adipose tissue.
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Affiliation(s)
| | - Thaís Marques Silva
- Laboratory of Physiology, Federal University of São João del-Rei, Divinópolis, Minas Gerais, Brazil
| | - William Gustavo Lima
- Laboratory of Physiology, Federal University of São João del-Rei, Divinópolis, Minas Gerais, Brazil
| | | | - Valéria Ernestânia Chaves
- Laboratory of Physiology, Federal University of São João del-Rei, Divinópolis, Minas Gerais, Brazil.
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16
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Forester SM, Widaman AM, Krishnan S, Witbracht MG, Horn WF, Laugero KD, Keim NL. A Clear Difference Emerges in Hormone Patterns Following a Standard Midday Meal in Young Women Who Regularly Eat or Skip Breakfast. J Nutr 2018; 148:685-692. [PMID: 29897486 DOI: 10.1093/jn/nxy020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 10/25/2017] [Accepted: 01/23/2018] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Multiple hormones are involved in the regulation of food intake and glucose metabolism. Past intervention studies showed a benefit of eating breakfast on satiety, but this was possibly confounded by the disruption of habitual meal patterns. OBJECTIVE The objective of this study was to compare hormonal responses, including insulin, leptin, glucagon-like peptide-1, ghrelin, peptide YY (PYY3-36), and cholecystokinin (CCK), between habitual breakfast eaters (Br-Es) and habitual skippers (Br-Ss) to a standard midday meal. METHODS Thirty-two women [mean ± SD age: 22.6 ± 3.3 y; body mass index (in kg/m2): 21.8 ± 2.0] participated in a cross-sectional study that consisted of a 3-h test protocol that included a standard test meal served at 1230 with pre- and postmeal blood sampling. The protocol required that Br-Es eat a typical breakfast between 0700 and 1000, whereas Br-Ss had no breakfast meal and had fasted for 12 h. Blood was drawn 35 and 5 min prelunch and 5, 20, 35, 50, and 110 min postlunch. RESULTS Repeated-measures ANOVA revealed a group difference for PYY3-36 (P = 0.001), with the Br-E group exhibiting 50-90% higher concentrations throughout the test period. Leptin tended to be different (P = 0.08) between groups, with higher mean ± SD values for the Br-S group (27.6 ± 29.6 ng/mL) compared with the Br-E group (11.5 ± 9.8 ng/mL). Partial least squares regression analysis confirmed that these 2 hormones were important contributors to the patterns of the hormones, anthropometric, clinical, and behavioral variables that differed between groups; insulin and CCK were important as well. CONCLUSION We found differences between the Br-E and Br-S groups in circulating gut and adipose-derived hormones measured midday, indicating that the breakfast habit is associated with the hormonal milieu before and after a midday meal. The different patterns may be short-lived or may impact metabolism later in the day. This report is a secondary analysis of a trial registered at clinicaltrials.gov as NCT01427556.
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Affiliation(s)
| | - Adrianne M Widaman
- Nutrition, Food Science & Packaging Department, San Jose State University, San Jose, CA
| | - Sridevi Krishnan
- Department of Nutrition, University of California, Davis, CA.,US Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center, Obesity and Metabolism Research Unit, Davis, CA
| | - Megan G Witbracht
- University of California Irvine Institute for Memory Impairments and Neurological Disorders, Irvine, CA
| | - William F Horn
- US Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center, Obesity and Metabolism Research Unit, Davis, CA
| | - Kevin D Laugero
- Department of Nutrition, University of California, Davis, CA.,US Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center, Obesity and Metabolism Research Unit, Davis, CA
| | - Nancy L Keim
- Department of Nutrition, University of California, Davis, CA.,US Department of Agriculture, Agricultural Research Service, Western Human Nutrition Research Center, Obesity and Metabolism Research Unit, Davis, CA
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17
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El Hachmane MF, Olofsson CS. A mechanically activated TRPC1-like current in white adipocytes. Biochem Biophys Res Commun 2018. [PMID: 29524421 DOI: 10.1016/j.bbrc.2018.03.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ca2+ impacts a large array of cellular processes in every known cell type. In the white adipocyte, Ca2+ is involved in regulation of metabolic processes such as lipolysis, glucose uptake and hormone secretion. Although the importance of Ca2+ in control of white adipocyte function is clear, knowledge is still lacking regarding the control of dynamic Ca2+ alterations within adipocytes and mechanisms inducing intracellular Ca2+ changes remain elusive. Own work has recently demonstrated the existence of store-operated Ca2+ entry (SOCE) in lipid filled adipocytes. We defined stromal interaction molecule 1 (STIM1) and the calcium release-activated calcium channel protein 1 (ORAI1) as the key players involved in this process and we showed that the transient receptor potential (TRP) channel TRPC1 contributed to SOCE. Here we have aimed to further characterised SOCE in the white adipocyte by use of single cell whole-cell patch clamp recordings. The electrophysiological measurements show the existence of a seemingly constitutively active current that is inhibited by known store-operated Ca2+ channel (SOCC) blockers. We demonstrate that the mechanical force applied to the plasma membrane upon patching leads to an elevation of the cytoplasmic Ca2+ concentration and that this elevation can be reversed by SOCC antagonists. We conclude that a mechanically activated current with properties similar to TRPC1 is present in white adipocytes. Activation of TRPC1 by membrane tension/stretch may be specifically important for the function of this cell type, since adipocytes can rapidly increase or decrease in size.
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Affiliation(s)
- Mickaël F El Hachmane
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Charlotta S Olofsson
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden.
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18
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Extracellular ATP activates store-operated Ca 2+ entry in white adipocytes: functional evidence for STIM1 and ORAI1. Biochem J 2018; 475:691-704. [PMID: 29335300 PMCID: PMC5813502 DOI: 10.1042/bcj20170484] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 01/05/2018] [Accepted: 01/13/2018] [Indexed: 12/26/2022]
Abstract
In the present study, we have applied ratiometric measurements of intracellular Ca2+ concentrations ([Ca2+]i) to show that extracellularly applied ATP (adenosine triphosphate) (100 µM) stimulates store-operated Ca2+ entry (SOCE) in 3T3-L1 adipocytes. ATP produced a rapid increase in [Ca2+]i consisting of an initial transient elevation followed by a sustained elevated phase that could be observed only in the presence of extracellular Ca2+. Gene expression data and [Ca2+]i recordings with uridine-5′-triphosphate or with the phospholipase C (PLC) inhibitor U73122 demonstrated the involvement of purinergic P2Y2 receptors and the PLC/inositol trisphosphate pathway. The [Ca2+]i elevation produced by reintroduction of a Ca2+-containing intracellular solution to adipocytes exposed to ATP in the absence of Ca2+ was diminished by known SOCE antagonists. The chief molecular components of SOCE, the stromal interaction molecule 1 (STIM1) and the calcium release-activated calcium channel protein 1 (ORAI1), were detected at the mRNA and protein level. Moreover, SOCE was largely diminished in cells where STIM1 and/or ORAI1 had been silenced by small interfering (si)RNA. We conclude that extracellular ATP activates SOCE in white adipocytes, an effect predominantly mediated by STIM1 and ORAI1.
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19
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Novel leptin OB3 peptide-induced signaling and progression in thyroid cancers: Comparison with leptin. Oncotarget 2018; 7:27641-54. [PMID: 27050378 PMCID: PMC5053677 DOI: 10.18632/oncotarget.8505] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 03/18/2016] [Indexed: 12/25/2022] Open
Abstract
Obesity results in increased secretion of cytokines from adipose tissue and is a risk factor for various cancers. Leptin is largely produced by adipose tissue and cancer cells. It induces cell proliferation and may serve to induce various cancers. OB3-leptin peptide (OB3) is a new class of functional leptin peptide. However, its mitogenic effect has not been determined. In the present study, because of a close link between leptin and the hypothalamic-pituitary-thyroid axis, OB3 was compared with leptin in different thyroid cancer cells for gene expression, proliferation and invasion. Neither agent stimulated cell proliferation. Leptin stimulated cell invasion, but reduced adhesion in anaplastic thyroid cancer cells. Activated ERK1/2 and STAT3 contributed to leptin-induced invasion. In contrast, OB3 did not affect expression of genes involved in proliferation and invasion. In vivo studies in the mouse showed that leptin, but not OB3, significantly increased circulating levels of thyrotropin (TSH), a growth factor for thyroid cancer. In summary, OB3 is a derivative of leptin that importantly lacks the mitogenic effects of leptin on thyroid cancer cells.
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20
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Haxho F, Neufeld RJ, Szewczuk MR. Neuraminidase-1: a novel therapeutic target in multistage tumorigenesis. Oncotarget 2018; 7:40860-40881. [PMID: 27029067 PMCID: PMC5130050 DOI: 10.18632/oncotarget.8396] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 03/18/2016] [Indexed: 12/15/2022] Open
Abstract
Several of the growth factors and their receptor tyrosine kinases (RTK) such as epidermal growth factor (EGF), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), vascular endothelial growth factor (VEGF), nerve growth factor (NGF) and insulin are promising candidate targets for cancer therapy. Indeed, tyrosine kinase inhibitors (TKI) have been developed to target these growth factors and their receptors, and have demonstrated dramatic initial responses in cancer therapy. Yet, most patients ultimately develop TKI drug resistance and relapse. It is essential in the clinical setting that the targeted therapies are to circumvent multistage tumorigenesis, including genetic mutations at the different growth factor receptors, tumor neovascularization, chemoresistance of tumors, immune-mediated tumorigenesis and the development of tissue invasion and metastasis. Here, we identify a novel receptor signaling platform linked to EGF, NGF, insulin and TOLL-like receptor (TLR) activations, all of which are known to play major roles in tumorigenesis. The importance of these findings signify an innovative and promising entirely new targeted therapy for cancer. The role of mammalian neuraminidase-1 (Neu1) in complex with matrix metalloproteinase-9 and G protein-coupled receptor tethered to RTKs and TLRs is identified as a major target in multistage tumorigenesis. Evidence exposing the link connecting growth factor-binding and immune-mediated tumorigenesis to this novel receptor-signaling paradigm will be reviewed in its current relationship to cancer.
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Affiliation(s)
- Fiona Haxho
- Departments of Biomedical and Molecular Sciences, Kingston, Ontario, Canada
| | - Ronald J Neufeld
- Department of Chemical Engineering, Queen's University, Kingston, Ontario, Canada
| | - Myron R Szewczuk
- Departments of Biomedical and Molecular Sciences, Kingston, Ontario, Canada
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21
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Long Y, Xia JY, Chen SW, Gao CL, Liang GN, He XM, Wu J, Jiang CX, Liu X, Huang W, Wan Q, Xu Y. ATP2B1 gene Silencing Increases Insulin Sensitivity through Facilitating Akt Activation via the Ca 2+/calmodulin Signaling Pathway and Ca 2+-associated eNOS Activation in Endothelial Cells. Int J Biol Sci 2017; 13:1203-1212. [PMID: 29104511 PMCID: PMC5666335 DOI: 10.7150/ijbs.19666] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 06/28/2017] [Indexed: 01/11/2023] Open
Abstract
Endothelial cell insulin resistance may be partially responsible for the higher risk of atherosclerosis and cardiovascular disease in populations with insulin resistance and type 2 diabetes mellitus (T2DM). A genome-wide association study revealed a significant association between the ATPase plasma membrane Ca2+ transporting 1 (ATP2B1) gene and T2DM in two community-based cohorts from the Korea Association Resource Project. However, little is known about the implication of the ATP2B1 gene on T2DM. In the present study, we investigated the role of the ATP2B1 gene in endothelial cell insulin sensitivity. ATP2B1 gene silencing resulted in enhanced intracellular calcium concentrations and increased insulin-induced Akt activation compared to that in the negative siRNA-transfected HUVECs (Human Umbilical Vein Endothelial Cells). The elevated insulin sensitivity mediated by ATP2B1 gene silencing was Ca2+/calmodulin-dependent, as verified by administration of the calcium chelator BAPTA-AM or the calmodulin-specific antagonist W7. Moreover, higher levels of phosphorylation of eNOS (Ser1177) were observed in ATP2B1-silenced HUVECs. In addition to BAPTA-AM and W7, L-NAME, an eNOS antagonist, abolished insulin-induced Akt phosphorylation at Ser473 in both si-Neg and si-ATP2B1-transfected endothelial cells. These results indicate that the enhanced insulin sensitivity in ATP2B1-silenced endothelial cells is alternatively dependent on an increase in intracellular Ca2+ and the subsequent activation of the Ca2+/calmodulin/eNOS/Akt signaling pathway. In summary, ATP2B1 gene silencing increased insulin sensitivity in endothelial cells by directly modulating the Ca2+/calmodulin signaling pathway and via the Ca2+/calmodulin/eNOS/Akt signaling pathway alternatively.
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Affiliation(s)
- Yang Long
- Department of Endocrinology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China.,Laboratory of Endocrinology, Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Ji-Yi Xia
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Shao-Wei Chen
- Medical Reproduction Center, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Chen-Lin Gao
- Department of Endocrinology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Guan-Nan Liang
- Laboratory of Endocrinology, Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Xue-Mei He
- Laboratory of Endocrinology, Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Jian Wu
- Laboratory of Endocrinology, Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Chun-Xia Jiang
- Department of Endocrinology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Xin Liu
- Laboratory of Endocrinology, Experimental Medicine Center, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Wei Huang
- Department of Endocrinology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Qin Wan
- Department of Endocrinology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China
| | - Yong Xu
- Department of Endocrinology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, Sichuan, P R China.,Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Disease, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, 646000, Sichuan, P R China
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Capsaicin reduces Alzheimer-associated tau changes in the hippocampus of type 2 diabetes rats. PLoS One 2017; 12:e0172477. [PMID: 28225806 PMCID: PMC5321461 DOI: 10.1371/journal.pone.0172477] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 02/05/2017] [Indexed: 01/12/2023] Open
Abstract
Type 2 diabetes (T2D) is a high-risk factor for Alzheimer’s disease (AD) due to impaired insulin signaling pathway in brain. Capsaicin is a specific transient receptor potential vanilloid 1 (TRPV1) agonist which was proved to ameliorate insulin resistance. In this study, we investigated whether dietary capsaicin could reduce the risk of AD in T2D. T2D rats were fed with capsaicin-containing high fat (HF) diet for 10 consecutive days (T2D+CAP). Pair-fed T2D rats (T2D+PF) fed with the HF-diet of average dose of T2D+CAP group were included to control for the effects of reduced food intake and body weight. Capsaicin-containing standard chow was also introduced to non-diabetic rats (NC+CAP). Blood glucose and insulin were monitored. The phosphorylation level of tau at individual sites, the activities of phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT) and glycogen synthase kinase-3β (GSK-3β) were analyzed by Western blots. The results revealed that the levels of phosphorylated tau protein at sites Ser199, Ser202 and Ser396 in hippocampus of T2D+CAP group were decreased significantly, but these phospho-sites in T2D+PF group didn’t show such improvements compared with T2D group. There were almost no changes in non-diabetic rats on capsaicin diet (NC+CAP) compared with the non-diabetic rats with normal chow (NC). Increased activity of PI3K/AKT and decreased activity of GSK-3β were detected in hippocampus of T2D+CAP group compared with T2D group, and these changes did not show in T2D+PF group either. These results demonstrated that dietary capsaicin appears to prevent the hyperphosphorylation of AD-associated tau protein by increasing the activity of PI3K/AKT and inhibiting GSK-3β in hippocampus of T2D rats, which supported that dietary capsaicin might have a potential use for the prevention of AD in T2D.
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Wang LH, Liu YC, Wang JH, Lee CJ, Hsu BG. Serum leptin level positively correlates with metabolic syndrome among elderly Taiwanese. Tzu Chi Med J 2017; 29:159-164. [PMID: 28974910 PMCID: PMC5615996 DOI: 10.4103/tcmj.tcmj_60_17] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Objective: Leptin is an adipocyte-derived hormone and has shown positive correlation with obesity and metabolic syndrome (MetS) in many studies. However, there are few studies investigating this relation in elderly people. Therefore, we aimed to investigate the correlation between the fasting serum leptin level and MetS among older Taiwanese. Materials and Methods: The fasting serum leptin level was obtained from 62 Taiwanese participants over 65 years old and was measured using a commercially available enzyme immunoassay kit. MetS and its components were defined using diagnostic criteria from the International Diabetes Federation. Results: Thirty elderly participants (48.4%) had MetS. The serum leptin level was positively correlated with MetS (P < 0.001). Multivariate logistic regression analysis of the factors significantly associated with MetS showed that logarithmically transformed leptin (log-leptin, each increase 0.1 ng/mL log-leptin, odds ratio: 1.276, 95% confidence interval: 1.015–1.603, P = 0.037) was still an independent predictor of MetS in elderly persons. Univariable linear analysis showed that body weight (r = 0280, P = 0.028), body mass index (r = 0.417, P = 0.001), waist circumference (r = 0.419, P = 0.001), blood urea nitrogen (r = 0255, P = 0.046), log-insulin (r = 0436, P < 0.001), and logarithmically transformed homeostasis model assessment of insulin resistance (r = 0359, P = 0.004) positively correlated with fasting serum log-leptin levels. Multivariate forward stepwise linear regression analysis of the factors significantly associated with fasting serum log-leptin levels revealed that waist circumference (adjusted R2 = 0.083, P = 0.002), statin use (adjusted R2 = 0.058, P = 0.016), and female gender (adjusted R2 = 0.041, P = 0.034) were independent predictors of fasting serum log-leptin levels among elderly participants. Conclusion: In elderly Taiwanese, the serum leptin level was positively correlated with MetS. Waist circumference, statin use, and female gender were independent predictors of the fasting serum leptin level in elderly participants.
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Affiliation(s)
- Li-Hsuan Wang
- School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Yao-Chang Liu
- School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Ji-Hung Wang
- School of Medicine, Tzu Chi University, Hualien, Taiwan.,Division of Cardiology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
| | - Chung-Jen Lee
- Department of Nursing, Tzu Chi University of Science and Technology, Hualien, Taiwan
| | - Bang-Gee Hsu
- School of Medicine, Tzu Chi University, Hualien, Taiwan.,Division of Nephrology, Buddhist Tzu Chi General Hospital, Hualien, Taiwan
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Zhai X, Jia M, Chen L, Zheng CJ, Rahman K, Han T, Qin LP. The regulatory mechanism of fungal elicitor-induced secondary metabolite biosynthesis in medical plants. Crit Rev Microbiol 2016; 43:238-261. [PMID: 27936989 DOI: 10.1080/1040841x.2016.1201041] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
A wide range of external stress stimuli trigger plant cells to undergo complex network of reactions that ultimately lead to the synthesis and accumulation of secondary metabolites. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Throughout evolution, endophytic fungi, an important constituent in the environment of medicinal plants, have known to form long-term stable and mutually beneficial symbiosis with medicinal plants. The endophytic fungal elicitor can rapidly and specifically induce the expression of specific genes in medicinal plants which can result in the activation of a series of specific secondary metabolic pathways resulting in the significant accumulation of active ingredients. Here we summarize the progress made on the mechanisms of fungal elicitor including elicitor signal recognition, signal transduction, gene expression and activation of the key enzymes and its application. This review provides guidance on studies which may be conducted to promote the efficient synthesis and accumulation of active ingredients by the endogenous fungal elicitor in medicinal plant cells, and provides new ideas and methods of studying the regulation of secondary metabolism in medicinal plants.
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Affiliation(s)
- Xin Zhai
- a Department of Pharmacognosy, School of Pharmacy , Second Military Medical University , Shanghai , China
| | - Min Jia
- a Department of Pharmacognosy, School of Pharmacy , Second Military Medical University , Shanghai , China
| | - Ling Chen
- a Department of Pharmacognosy, School of Pharmacy , Second Military Medical University , Shanghai , China
| | - Cheng-Jian Zheng
- a Department of Pharmacognosy, School of Pharmacy , Second Military Medical University , Shanghai , China
| | - Khalid Rahman
- b Department of Physiological Biochemistry, Faculty of Science, School of Pharmacy and Biomolecular Sciences , Liverpool John Moores University , Liverpool , UK
| | - Ting Han
- a Department of Pharmacognosy, School of Pharmacy , Second Military Medical University , Shanghai , China
| | - Lu-Ping Qin
- a Department of Pharmacognosy, School of Pharmacy , Second Military Medical University , Shanghai , China
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25
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Yan AF, Chen T, Chen S, Tang DS, Liu F, Jiang X, Huang W, Ren CH, Hu CQ. Signal transduction mechanism for glucagon-induced leptin gene expression in goldfish liver. Int J Biol Sci 2016; 12:1544-1554. [PMID: 27994518 PMCID: PMC5166495 DOI: 10.7150/ijbs.16612] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 10/12/2016] [Indexed: 12/24/2022] Open
Abstract
Leptin is a peripheral satiety hormone that also plays important roles in energy homeostasis in vertebrates ranging from fish to mammals. In teleost fish, however, the regulatory mechanism for leptin gene expression still remains unclear. In this study, we found that glucagon, a key hormone in glucose homeostasis, was effective at elevating the leptin-AI and leptin-AII transcript levels in goldfish liver via both in vivo intraperitoneal injection and in vitro cells incubation approaches. The responses of leptin-AI and leptin-AII mRNA to glucagon treatment were highly comparable. In contrast, blockade of local glucagon action could reduce the basal and induced leptin-AI and leptin-AII mRNA expression. The stimulation of leptin levels by glucagon was caused by the activation of adenylate cyclase (AC)/cyclic-AMP (cAMP)/ protein kinase A (PKA), and probably cAMP response element-binding protein (CREB) cascades. Our study described the effect and signal transduction mechanism of glucagon on leptin gene expression in goldfish liver, and may also provide new insight into leptin as a mediator in the regulatory network of energy metabolism in the fish model.
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Affiliation(s)
- Ai-Fen Yan
- School of stomatology and medicine, Foshan University, Foshan 528000, China
| | - Ting Chen
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China
| | - Shuang Chen
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China
| | - Dong-Sheng Tang
- School of stomatology and medicine, Foshan University, Foshan 528000, China
| | - Fang Liu
- School of stomatology and medicine, Foshan University, Foshan 528000, China
| | - Xiao Jiang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB)
| | - Wen Huang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB)
| | - Chun-Hua Ren
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China
| | - Chao-Qun Hu
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); South China Sea Bio-Resource Exploitation and Utilization Collaborative Innovation Center, Guangzhou 510275, China
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26
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Tsubai T, Noda Y, Ito K, Nakao M, Seino Y, Oiso Y, Hamada Y. Insulin elevates leptin secretion and mRNA levels via cyclic AMP in 3T3-L1 adipocytes deprived of glucose. Heliyon 2016; 2:e00194. [PMID: 27896318 PMCID: PMC5121139 DOI: 10.1016/j.heliyon.2016.e00194] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2016] [Revised: 10/17/2016] [Accepted: 11/08/2016] [Indexed: 02/04/2023] Open
Abstract
Aims Leptin plays an important role in the pathogenesis of obesity and diabetes, yet the regulatory mechanisms of this hormone have not been fully elucidated. In this study, we aimed to clarify the roles of insulin and glucose in leptin secretion and mRNA production using inhibitors of insulin signal transduction in adipocytes cultured under glucose-free or normal conditions. Methods Differentiated 3T3-L1 adipocytes were stimulated with insulin in combination with inhibitors for phosphoinositide 3-kinase (PI3K), Akt, and phosphodiesterase 3B (PDE3B), as well as epinephrine and a cyclic AMP (cAMP) analog under glucose-free or normal conditions. After 8 h of stimulation, leptin protein levels in the media and leptin mRNA expression levels in the adipocytes were measured. Results Insulin significantly increased the secretion and mRNA levels of leptin under the depletion of glucose. Glucose augmented basal leptin secretion without insulin, while glucose nullified insulin-induced leptin mRNA upregulation. The PI3K inhibitor BEZ-235, the Akt inhibitor MK-2206, and the PDE3B inhibitor cilostazol attenuated the insulin stimulation of leptin secretion, but did not suppress the insulin-induced leptin mRNA upregulation with glucose depletion. In contrast to the glucose-free condition, insulin failed to upregulate leptin mRNA in the presence of glucose. The cAMP analog dibutyryl cAMP and epinephrine decreased both leptin secretion and mRNA regardless of glucose supplementation. Conclusion Insulin alone stimulates leptin secretion and elevates leptin mRNA levels via cAMP under the lack of glucose metabolism, while glucose is a significant and ambivalent effector on the insulin effects of leptin.
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Affiliation(s)
- Tomomi Tsubai
- College of Pharmacy, Kinjo Gakuin University; Omori 2-1723, Moriyama-ku, Nagoya 463-8521, Japan
- Division of Clinical Science and Neuropsychopharmacology, Graduate School and Faculty of Pharmacy, Meijo University; 150, Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yukihiro Noda
- Division of Clinical Science and Neuropsychopharmacology, Graduate School and Faculty of Pharmacy, Meijo University; 150, Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Kazuma Ito
- Division of Clinical Science and Neuropsychopharmacology, Graduate School and Faculty of Pharmacy, Meijo University; 150, Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Makoto Nakao
- College of Pharmacy, Kinjo Gakuin University; Omori 2-1723, Moriyama-ku, Nagoya 463-8521, Japan
| | - Yusuke Seino
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine; 65, Tsuruma-cho, Showa-ku, Nagoya 466-8560, Japan
| | - Yutaka Oiso
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine; 65, Tsuruma-cho, Showa-ku, Nagoya 466-8560, Japan
| | - Yoji Hamada
- Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine; 65, Tsuruma-cho, Showa-ku, Nagoya 466-8560, Japan
- Corresponding author at: Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466–8550, Japan.
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27
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Role of Exchange Protein Directly Activated by Cyclic AMP Isoform 1 in Energy Homeostasis: Regulation of Leptin Expression and Secretion in White Adipose Tissue. Mol Cell Biol 2016; 36:2440-50. [PMID: 27381457 DOI: 10.1128/mcb.01034-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 06/17/2016] [Indexed: 12/18/2022] Open
Abstract
Epacs (exchange proteins directly activated by cyclic AMP [cAMP]) act as downstream effectors of cAMP and play important roles in energy balance and glucose homeostasis. While global deletion of Epac1 in mice leads to heightened leptin sensitivity in the hypothalamus and partial protection against high-fat diet (HFD)-induced obesity, the physiological functions of Epac1 in white adipose tissue (WAT) has not been explored. Here, we report that adipose tissue-specific Epac1 knockout (AEKO) mice are more prone to HFD-induced obesity, with increased food intake, reduced energy expenditure, and impaired glucose tolerance. Despite the fact that AEKO mice on HFD display increased body weight, these mice have decreased circulating leptin levels compared to their wild-type littermates. In vivo and in vitro analyses further reveal that suppression of Epac1 in WAT decreases leptin mRNA expression and secretion by inhibiting cAMP response element binding (CREB) protein and AKT phosphorylation, respectively. Taken together, our results demonstrate that Epac1 plays an important role in regulating energy balance and glucose homeostasis by promoting leptin expression and secretion in WAT.
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28
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Angotzi AR, Stefansson SO, Nilsen TO, Øvrebø JI, Andersson E, Taranger GL, Rønnestad I. Identification of a novel leptin receptor duplicate in Atlantic salmon: Expression analyses in different life stages and in response to feeding status. Gen Comp Endocrinol 2016; 235:108-119. [PMID: 27288639 DOI: 10.1016/j.ygcen.2016.06.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 06/07/2016] [Indexed: 12/26/2022]
Abstract
In recent years rapidly growing research has led to identification of several fish leptin orthologs and numerous duplicated paralogs possibly arisen from the third and fourth round whole genome duplication (3R and 4R WGD) events. In this study we identify in Atlantic salmon a duplicated LepRA gene, named LepRA2, that further extend possible evolutionary scenarios of the leptin and leptin receptor system. The 1121 amino acid sequence of the novel LepRA2 shares 80% sequence identity with the LepRA1 paralog, and contains the protein motifs typical of the functional (long form) leptin receptor in vertebrates. In silico predictions showed similar electrostatic properties of LepRA1 and LepRA2 and high sequence conservation at the leptin interaction surfaces within the CHR/leptin-binding and FNIII domains, suggesting conserved functional specificity between the two duplicates. Analysis of temporal expression profiles during pre-hatching stages indicate that both transcripts are involved in modulating leptin developmental functions, although the LepRA1 paralog may play a major role as the embryo complexity increases. There is ubiquitous distribution of LepRs underlying pleiotropism of leptin in all tissues investigated. LepRA1 and LepRA2 are differentially expressed with LepRA1 more abundant than LepRA2 in most of the tissues investigated, with the only exception of liver. Analysis of constitutive LepRA1 and LepRA2 expression in brain and liver at parr, post-smolt and adult stages reveal striking spatial divergence between the duplicates at all stages investigated. This suggests that, beside increased metabolic requirements, leptin sensitivity in the salmon brain might be linked to important variables such as habitat, ecology and life cycle. Furthermore, leptins and LepRs mRNAs in the brain showed gene-specific variability in response to long term fasting, suggesting that leptin's roles as modulator of nutritional status in Atlantic salmon might be governed by distinct genetic evolutionary processes and distinct functions between the paralogs.
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Affiliation(s)
- Anna R Angotzi
- Department of Biology, University of Bergen, Thormølensgate 55, Bergen 5020, Norway
| | - Sigurd O Stefansson
- Department of Biology, University of Bergen, Thormølensgate 55, Bergen 5020, Norway
| | - Tom O Nilsen
- Uni Research Environment, Thormøhlensgate 49 B, N-5006 Bergen, Norway
| | - Jan I Øvrebø
- Department of Biology, University of Bergen, Thormølensgate 55, Bergen 5020, Norway; Huntsman Cancer Institute, University of Utah, 2000 Circle of Hope Drive, Salt Lake City, UT 84112, USA
| | - Eva Andersson
- Institute of Marine Research, P.O. Box 187, Nordnes, N-5817 Bergen, Norway
| | - Geir L Taranger
- Institute of Marine Research, P.O. Box 187, Nordnes, N-5817 Bergen, Norway
| | - Ivar Rønnestad
- Department of Biology, University of Bergen, Thormølensgate 55, Bergen 5020, Norway.
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Association of Increased Serum Leptin with Ameliorated Anemia and Malnutrition in Stage 5 Chronic Kidney Disease Patients after Parathyroidectomy. Sci Rep 2016; 6:27918. [PMID: 27307101 PMCID: PMC4910047 DOI: 10.1038/srep27918] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 05/26/2016] [Indexed: 01/11/2023] Open
Abstract
Leptin is an adipokine that regulates various metabolism, but its association with secondary hyperparathyroidism (SHPT), a clinical manifestation of chronic kidney disease-mineral and bone disorder (CKD-MBD), remains obscure. Parathyroidectomy (PTX) is recommended for severe SHPT patients. Here, the associations between circulating leptin and clinical characteristics in CKD patients were investigated. Effects of PTX on leptin production were analyzed in vivo and in vitro. Controls and CKD patients had approximate serum leptin levels in that a larger proportion of CKD patients with body mass index (BMI) <23 kg/m2. Serum leptin was related to anemia, albumin, and bone metabolism disorders in CKD patients. Lower intact parathyroid hormone (PTH) was related with higher leptin in PTX patients group. Severe SHPT inhibited uremia-enhanced leptin production in 3T3-L1 adipocytes, which was attenuated after PTX. High levels of PTH were found to reduce Akt phosphorylation and leptin production in vitro but high levels of calcium and phosphorus were not. Successful PTX was found to improve anemia and malnutrition in severe SHPT patients, and this was correlated with increased circulating leptin levels via up-regulated Akt signaling in adipocytes. These findings indicated the therapeutic potential of leptin and related target pathway for improving survival and quality of life in CKD.
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30
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Adiponectin is released via a unique regulated exocytosis pathway from a pre-formed vesicle pool on insulin stimulation. Biochem J 2015; 471:381-9. [PMID: 26330614 DOI: 10.1042/bj20150301] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 09/01/2015] [Indexed: 12/15/2022]
Abstract
Adiponectin, a hormone secreted from adipocytes and released at a high rate into the circulation, plays a pivotal role in maintaining insulin sensitivity at the whole-body level. Despite the importance of this adipokine in metabolic homoeostasis, the mechanism of its secretion from adipocytes remains largely unclear. In the present study, we investigated the subcellular localization of adiponectin, and its secretion regulation in 3T3-L1-differentiated adipocytes, using biochemical methods and fluorescence microscopic imaging. We show that adiponectin is localized in vesicular compartments with no apparent overlap with the Golgi apparatus or endosomes. Moreover, adiponectin-containing vesicles are enriched in two distinct pools: one at the plasma membrane (PM) and the other co-fractionating with endoplasmic reticulum membranes. When viewed under a total internal refection fluorescence microscope, a subset of adiponectin-Venus vesicles is readily observed in proximity to PMs, and could be released in response to insulin. Insulin-stimulated adiponectin release appears to be from a pre-existing pool of vesicles, and is not dependent on new protein synthesis, because adiponectin mRNA levels remain unchanged over a 6-h period of insulin treatment, and inhibition of protein synthesis has no effect on adiponectin release. Disruption of insulin signalling by inhibitors of phosphoinositide 3-kinase and protein kinase B (Akt)-1/2 abrogates the stimulated release of adiponectin. Taken together, our results show that adiponectin is stored in a unique vesicular compartment, and released through a regulated exocytosis pathway that is dependent on insulin signalling.
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Zhao J, Fan B, Wu Z, Xu M, Luo Y. Serum zinc is associated with plasma leptin and Cu-Zn SOD in elite male basketball athletes. J Trace Elem Med Biol 2015; 30:49-53. [PMID: 25434301 DOI: 10.1016/j.jtemb.2014.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 10/10/2014] [Accepted: 10/15/2014] [Indexed: 01/10/2023]
Abstract
This paper investigates the relationship between plasma trace element and plasma leptin, as well as percent fat mass, in 16 male basketball athletes. Blood samples were obtained before intensive training and 24h after intensive training to measure plasma zinc (Zn), copper (Cu), calcium (Ca), magnesium (Mg), iron (Fe), and leptin levels. High-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), triglyceride (TG), total and cholesterol (TC) levels were determined using commercially available kits for humans. Subjects presented similar values in terms of age (21.1±2.2 years old), body mass index (23.9±2.00kg/m(2)), percent body fat (14.40±1.52%), plasma hemoglobin (150.1±9.4g/L), plasma Zn (17.47±1.28μmol/l), plasma Cu (13.42±1.40μmol/L), plasma Ca (2.41±0.14mmol/L), and plasma Mg (0.96±0.02mmol/L). The correlation analysis between degree of plasma leptin and plasma element contents was performed using the SPSS 16.0 software. Plasma Zn correlated positively with plasma leptin (r=0.746, P<0.01), Cu-Zn SOD (r=0.827, P<0.01), and negatively with percent fat mass (r=-0.598, P<0.05) under no-training conditions. Meanwhile, plasma Cu, Ca, Mg, and Fe did not correlate with plasma leptin or percent fat mass (P>0.05). In conclusion, plasma Zn may be involved in the regulation of plasma leptin and may serve as a lipid-mobilizing factor in Chinese men's basketball athletes.
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Affiliation(s)
- Jiexiu Zhao
- Sport Biological Center, China Institute of Sport Science, General Administration of Sport, Beijing, China.
| | - Bin Fan
- Chinese Men's Basketball Team, Beijing, China
| | - Zhaozhao Wu
- Sport Biological Center, China Institute of Sport Science, General Administration of Sport, Beijing, China
| | - Minxiao Xu
- Physical Education Department, Qufu Normal University, Qufu, China; Sport Biological Center, China Institute of Sport Science, General Administration of Sport, Beijing, China
| | - Yufeng Luo
- Sport Biological Center, China Institute of Sport Science, General Administration of Sport, Beijing, China
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Salmerón C, Johansson M, Angotzi AR, Rønnestad I, Jönsson E, Björnsson BT, Gutiérrez J, Navarro I, Capilla E. Effects of nutritional status on plasma leptin levels and in vitro regulation of adipocyte leptin expression and secretion in rainbow trout. Gen Comp Endocrinol 2015; 210:114-23. [PMID: 25448259 DOI: 10.1016/j.ygcen.2014.10.016] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 10/01/2014] [Accepted: 10/31/2014] [Indexed: 11/17/2022]
Abstract
As leptin has a key role on appetite, knowledge about leptin regulation is important in order to understand the control of energy balance. We aimed to explore the modulatory effects of adiposity on plasma leptin levels in vivo and the role of potential regulators on leptin expression and secretion in rainbow trout adipocytes in vitro. Fish were fed a regular diet twice daily ad libitum or a high-energy diet once daily at two ration levels; satiation (SA group) or restricted (RE group) to 25% of satiation, for 8weeks. RE fish had significantly reduced growth (p<0.001) and adipose tissue weight (p<0.001), and higher plasma leptin levels (p=0.022) compared with SA fish. Moreover, plasma leptin levels negatively correlated with mesenteric fat index (p=0.009). Adipocytes isolated from the different fish were treated with insulin, ghrelin, leucine, eicosapentaenoic acid or left untreated (control). In adipocytes from fish fed regular diet, insulin and ghrelin increased leptin secretion dose-dependently (p=0.002; p=0.033, respectively). Leptin secretion in control adipocytes was significantly higher in RE than in SA fish (p=0.022) in agreement with the in vivo findings, indicating that adipose tissue may contribute to the circulating leptin levels. No treatment effects were observed in adipocytes from the high-energy diet groups, neither in leptin expression nor secretion, except that leptin secretion was significantly reduced by leucine in RE fish adipocytes (p=0.025). Overall, these data show that the regulation of leptin in rainbow trout adipocytes by hormones and nutrients seems to be on secretion, rather than at the transcriptional level.
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Affiliation(s)
- Cristina Salmerón
- Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain
| | - Marcus Johansson
- Fish Endocrinology Laboratory, Department of Biological and Environmental Sciences, University of Gothenburg, 40590 Gothenburg, Sweden
| | - Anna R Angotzi
- Department of Biology, University of Bergen, Bergen 5020, Norway
| | - Ivar Rønnestad
- Department of Biology, University of Bergen, Bergen 5020, Norway
| | - Elisabeth Jönsson
- Fish Endocrinology Laboratory, Department of Biological and Environmental Sciences, University of Gothenburg, 40590 Gothenburg, Sweden
| | - Björn Thrandur Björnsson
- Fish Endocrinology Laboratory, Department of Biological and Environmental Sciences, University of Gothenburg, 40590 Gothenburg, Sweden
| | - Joaquim Gutiérrez
- Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain
| | - Isabel Navarro
- Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain
| | - Encarnación Capilla
- Department of Physiology and Immunology, Faculty of Biology, University of Barcelona, Barcelona 08028, Spain.
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White adipose tissue resilience to insulin deprivation and replacement. PLoS One 2014; 9:e106214. [PMID: 25170835 PMCID: PMC4149534 DOI: 10.1371/journal.pone.0106214] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 08/04/2014] [Indexed: 11/19/2022] Open
Abstract
Introduction Adipocyte size and body fat distribution are strongly linked to the metabolic complications of obesity. The aim of the present study was to test the plasticity of white adipose tissue in response to insulin deprivation and replacement. We have characterized the changes of adipose cell size repartition and gene expressions in type 1 diabetes Sprague-Dawley rats and type 1 diabetic supplemented with insulin. Methods Using streptozotocin (STZ)-induced diabetes, we induced rapid changes in rat adipose tissue weights to study the changes in the distribution of adipose cell sizes in retroperitoneal (rWAT), epididymal (eWAT) and subcutaneous adipose tissues (scWAT). Adipose tissue weights of type 1 diabetic rats were then rapidly restored by insulin supplementation. Cell size distributions were analyzed using multisizer IV (Beckman Coulter). Cell size changes were correlated to transcriptional regulation of genes coding for proteins involved in lipid and glucose metabolisms and adipocytokines. Results The initial body weight of the rats was 465±5.2 g. Insulin privation was stopped when rats lost 100 g which induced reductions in fat mass of 68% for rWAT, 42% for eWAT and 59% for scWAT corresponding to decreased mode cell diameters by 31.1%, 20%, 25.3%, respectively. The most affected size distribution by insulin deprivation was observed in rWAT. The bimodal distribution of adipose cell sizes disappeared in response to insulin deprivation in rWAT and scWAT. The most important observation is that cell size distribution returned close to control values in response to insulin treatment. mRNAs coding for adiponectin, leptin and apelin were more stimulated in scWAT compared to other depots in diabetic plus insulin group. Conclusion Fat depots have specific responses to insulin deprivation and supplementation. The results show that insulin is a major determinant of bimodal cell repartition in adipose tissues.
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