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Miles TK, Odle AK, Byrum SD, Lagasse A, Haney A, Ortega VG, Bolen CR, Banik J, Reddick MM, Herdman A, MacNicol MC, MacNicol AM, Childs GV. Anterior Pituitary Transcriptomics Following a High-Fat Diet: Impact of Oxidative Stress on Cell Metabolism. Endocrinology 2023; 165:bqad191. [PMID: 38103263 PMCID: PMC10771268 DOI: 10.1210/endocr/bqad191] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 12/07/2023] [Accepted: 12/14/2023] [Indexed: 12/18/2023]
Abstract
Anterior pituitary cell function requires a high level of protein synthesis and secretion which depend heavily on mitochondrial adenosine triphosphate production and functional endoplasmic reticula. Obesity adds stress to tissues, requiring them to adapt to inflammation and oxidative stress, and adding to their allostatic load. We hypothesized that pituitary function is vulnerable to the stress of obesity. Here, we utilized a 10- to 15-week high-fat diet (HFD, 60%) in a thermoneutral environment to promote obesity, testing both male and female FVB.129P mice. We quantified serum hormones and cytokines, characterized the metabolic phenotype, and defined changes in the pituitary transcriptome using single-cell RNA-sequencing analysis. Weight gain was significant by 3 weeks in HFD mice, and by 10 weeks all HFD groups had gained 20 g. HFD females (15 weeks) had increased energy expenditure and decreased activity. All HFD groups showed increases in serum leptin and decreases in adiponectin. HFD caused increased inflammatory markers: interleukin-6, resistin, monocyte chemoattractant protein-1, and tumor necrosis factorα. HFD males and females also had increased insulin and increased TSH, and HFD females had decreased serum prolactin and growth hormone pulse amplitude. Pituitary single-cell transcriptomics revealed modest or no changes in pituitary cell gene expression from HFD males after 10 or 15 weeks or from HFD females after 10 weeks. However, HFD females (15 weeks) showed significant numbers of differentially expressed genes in lactotropes and pituitary stem cells. Collectively, these studies reveal that pituitary cells from males appear to be more resilient to the oxidative stress of obesity than females and identify the most vulnerable pituitary cell populations in females.
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Affiliation(s)
- Tiffany K Miles
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Angela K Odle
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Stephanie D Byrum
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- Department of Biomedical informatics, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- Arkansas Children's Research Institute, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Alex Lagasse
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Anessa Haney
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Victoria G Ortega
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Cole R Bolen
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Jewel Banik
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Milla M Reddick
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Ashley Herdman
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Melanie C MacNicol
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Angus M MacNicol
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Gwen V Childs
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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Mattar P, Toledo-Valenzuela L, Hernández-Cáceres MP, Peña-Oyarzún D, Morselli E, Perez-Leighton C. Integrating the effects of sucrose intake on the brain and white adipose tissue: Could autophagy be a possible link? Obesity (Silver Spring) 2022; 30:1143-1155. [PMID: 35578809 DOI: 10.1002/oby.23411] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 01/07/2022] [Accepted: 01/07/2022] [Indexed: 01/18/2023]
Abstract
Excess dietary sucrose is associated with obesity and metabolic diseases. This relationship is driven by the malfunction of several cell types and tissues critical for the regulation of energy balance, including hypothalamic neurons and white adipose tissue (WAT). However, the mechanisms behind these effects of dietary sucrose are still unclear and might be independent of increased adiposity. Accumulating evidence has indicated that dysregulation of autophagy, a fundamental process for maintenance of cellular homeostasis, alters energy metabolism in hypothalamic neurons and WAT, but whether autophagy could mediate the detrimental effects of dietary sucrose on hypothalamic neurons and WAT that contribute to weight gain is a matter of debate. In this review, we examine the hypothesis that dysregulated autophagy in hypothalamic neurons and WAT is an adiposity-independent effect of sucrose that contributes to increased body weight gain. We propose that excess dietary sucrose leads to autophagy unbalance in hypothalamic neurons and WAT, which increases caloric intake and body weight, favoring the emergence of obesity and metabolic diseases.
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Affiliation(s)
- Pamela Mattar
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Lilian Toledo-Valenzuela
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - María Paz Hernández-Cáceres
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
- Advanced Center for Chronic Diseases (ACCDiS), Universidad de Chile, Santiago, Chile
| | - Daniel Peña-Oyarzún
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Institute for Research in Dental Sciences, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
- Advanced Center for Chronic Diseases (ACCDiS), Universidad de Chile, Santiago, Chile
- Interdisciplinary Center for Research in Territorial Health of the Aconcagua Valley (CIISTe Aconcagua, School of Medicine, Faculty of Medicine, San Felipe Campus, University of Valparaiso, Valparaíso, Chile
| | - Eugenia Morselli
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Claudio Perez-Leighton
- Department of Physiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
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Tulipano G, Giustina A. Autophagy in normal pituitary and pituitary tumor cells and its potential role in the actions of somatostatin receptor ligands in acromegaly. Rev Endocr Metab Disord 2021; 22:147-160. [PMID: 33821422 DOI: 10.1007/s11154-021-09649-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/22/2021] [Indexed: 12/14/2022]
Abstract
Autophagy is an evolutionary conserved process for the self-degradation and recycling of cellular components in the cytoplasm. It is involved in both physiological and pathological conditions. In detail, the term "autophagy" refers to intracellular degradative pathways that lead to packaging and deliver of cellular components to lysosomes or to plant and yeast vacuoles. Autophagy is triggered by a variety of stimuli like nutrient deprivation, hypoxia, mitochondrial dysfunction, endoplasmic reticulum stress, and is regulated by immune- and hormonal factors. The role of autophagy in tumor cells is complex. Indeed, autophagy may act as a tumor suppressor as well as a tumor survival factor, in a context-dependent manner. The research into autophagy in normal pituitary and pituitary tumors has not gained great consideration, yet. Nevertheless, some recent articles joint to previous case studies, suggest that this process plays a role in the modulation and fluctuation of normal pituitary cell functions and in the response of pituitary tumor cells to drug therapy, including the response to somatostatin receptor ligand (SRLs), the first-line medical therapy of acromegaly. Although it is not possible to draw any conclusion, the aim of this review was to highlight some considerations and perspectives in this research field. Reports on the effects of octreotide on autophagy induction and autophagic flux in extra-pituitary target tissues, have also been discussed.
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Affiliation(s)
- Giovanni Tulipano
- Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.
| | - Andrea Giustina
- Institute of Endocrine and Metabolic Sciences, Division of Endocrinology IRCCS, Vita Salute San Raffaele University, San Raffaele Hospital, Milan, Italy
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Tulipano G, Giustina A. Effects of octreotide on autophagy markers and cell viability markers related to metabolic activity in rat pituitary tumor cells. Pituitary 2020; 23:223-231. [PMID: 31997055 DOI: 10.1007/s11102-020-01028-0] [Citation(s) in RCA: 4] [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] [Indexed: 02/07/2023]
Abstract
PURPOSE The aim of this work was to investigate possible direct effects of the somatostatin analog octreotide on autophagy markers and markers of cellular metabolic activity using in vitro cultured rat pituitary tumor cells (GH3 cell line). METHODS We measured two markers of the autophagic flux in cell lysates by Western blot and MTT reductive activity, total cellular ATP levels, pyruvate dehydrogenase (PDH) complex activity in cells lysates as markers of cell viability related to metabolic activity. RESULTS Octreotide (100 nM) treatment induced autophagy activation (increased LC3-I protein lipidation) and enhanced the autophagic flux (SQSTM1/p62 protein downregulation) in GH3 cells in different incubation media, in detail in Hank's balanced salt solution (HBSS) as well as in maintenance medium with serum. We did not observe any decrease of redox activity and energy production related to the induction of autophagy by octreotide. On the other hand, short-term treatments with octreotide in HBSS tended to enhance MTT reduction activity and to increase PDH complex enzymatic activity and ATP levels measured in GH3 cell lysates. CONCLUSIONS We provided evidence that octreotide can affect autophagy in pituitary tumor cells. The observed effects of octreotide were not related to a decrease of cellular metabolic activity. Finally, the induction of autophagy was either short-lived or overshadowed by other factors in the long term and this limit does not help clarifying their real impact on the pharmacological activity of somatostatin analogs.
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Affiliation(s)
- Giovanni Tulipano
- Unit of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Andrea Giustina
- Division of Endocrinology, IRCCS San Raffaele Hospital, San Raffaele Vita- Salute University - Head, Milan, Italy
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Meng LB, Zou YF, Shan MJ, Zhang M, Qi RM, Yu ZM, Guo P, Zheng QW, Gong T. Computer-assisted prediction of atherosclerotic intimal thickness based on weight of adrenal gland, interleukin-6 concentration, and neural networks. J Int Med Res 2019; 48:300060519839625. [PMID: 31039661 PMCID: PMC7140207 DOI: 10.1177/0300060519839625] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Objective Methods Results Conclusions
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Affiliation(s)
- Ling-Bing Meng
- Neurology Department, Beijing Hospital, National Center of Gerontology, Beijing, P.R. China.,*These authors contributed equally to this work
| | - Yang-Fan Zou
- Department of Neurosurgery, Chinese PLA General Hospital-Sixth Medical Center, Beijing, P.R. China.,*These authors contributed equally to this work
| | - Meng-Jie Shan
- MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
| | - Meng Zhang
- School of Energy Power and Mechanical Engineering, North China Electric Power University, Baoding, Hebei, P.R. China
| | - Ruo-Mei Qi
- MOH Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing, P.R. China
| | - Ze-Mou Yu
- Department of Neurology, Peking University First Hospital, Beijing, P. R. China
| | - Peng Guo
- Department of Orthopedics, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, P.R. China
| | - Qian-Wei Zheng
- Neurology Department, Beijing Hospital, National Center of Gerontology, Beijing, P.R. China
| | - Tao Gong
- Neurology Department, Beijing Hospital, National Center of Gerontology, Beijing, P.R. China
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Mercau ME, Calanni JS, Aranda ML, Caldareri LJ, Rosenstein RE, Repetto EM, Cymeryng CB. Melatonin prevents early pituitary dysfunction induced by sucrose-rich diets. J Pineal Res 2019; 66:e12545. [PMID: 30586198 DOI: 10.1111/jpi.12545] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 12/11/2018] [Accepted: 12/18/2018] [Indexed: 12/14/2022]
Abstract
While physiological levels of glucocorticoids are required to ensure proper functions of the body, consistently high levels may engender several deleterious consequences. We have previously shown an increase in the activity of the hypothalamic-pituitary-adrenal (HPA) axis in rats fed sucrose-rich diets (SRD). The main goal of this study was to analyze the processes involved in the modulation of the pituitary production of ACTH by SRD, and to test melatonin as a possible therapeutic agent for the prevention of the HPA axis dysfunction. Male Wistar rats were fed standard chow and either SRD (30% sucrose in the drinking water) or plain water for three weeks. Melatonin was administered as subcutaneous pellets. Results showed that SRD treatment induced an increase in systemic ACTH and corticosterone levels and a decrease in melatonin levels. In the pituitary gland, we also detected an increase in the expression levels of proopiomelanocortin (POMC) that was accompanied by increased levels of: lipoperoxides, nitro-tyrosine modified proteins, catalase, heme oxygenase-1, interleukin-1β mRNA, and by an increase in the tissue number of inflammatory cells (F4/80 and Iba-1 positive cells). Melatonin treatment prevented all these systemic and pituitary changes as well as the increase in POMC expression induced by incubation of AtT-20 corticotrophs with conditioned media obtained from stimulated macrophages. In conclusion, stimulation of POMC/ACTH production in rats fed a SRD could involve the generation of oxidative stress and inflammation in the pituitary gland. Melatonin treatment prevented these effects and normalized the activity of the HPA axis.
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Affiliation(s)
- María Elisa Mercau
- Facultad de Medicina, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Estudios Farmacológicos y Botánicos (CEFYBO), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Juan Salvador Calanni
- Facultad de Medicina, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Estudios Farmacológicos y Botánicos (CEFYBO), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Marcos Luis Aranda
- Facultad de Medicina, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Estudios Farmacológicos y Botánicos (CEFYBO), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Lilian Julia Caldareri
- Facultad de Medicina, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Estudios Farmacológicos y Botánicos (CEFYBO), Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ruth Estela Rosenstein
- Facultad de Medicina, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Estudios Farmacológicos y Botánicos (CEFYBO), Universidad de Buenos Aires, Buenos Aires, Argentina
- Facultad de Medicina, Departamento de Bioquímica Humana, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Esteban Martin Repetto
- Facultad de Medicina, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Estudios Farmacológicos y Botánicos (CEFYBO), Universidad de Buenos Aires, Buenos Aires, Argentina
- Facultad de Farmacia y Bioquímica, Departamento de Bioquímica Clínica, Cátedra Bioquímica Clínica I, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Cora Beatriz Cymeryng
- Facultad de Medicina, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Centro de Estudios Farmacológicos y Botánicos (CEFYBO), Universidad de Buenos Aires, Buenos Aires, Argentina
- Facultad de Medicina, Departamento de Bioquímica Humana, Universidad de Buenos Aires, Buenos Aires, Argentina
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Current Evidence for a Role of Neuropeptides in the Regulation of Autophagy. BIOMED RESEARCH INTERNATIONAL 2017; 2017:5856071. [PMID: 28593174 PMCID: PMC5448050 DOI: 10.1155/2017/5856071] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 04/30/2017] [Indexed: 12/14/2022]
Abstract
Neuropeptides drive a wide diversity of biological actions and mediate multiple regulatory functions involving all organ systems. They modulate intercellular signalling in the central and peripheral nervous systems as well as the cross talk among nervous and endocrine systems. Indeed, neuropeptides can function as peptide hormones regulating physiological homeostasis (e.g., cognition, blood pressure, feeding behaviour, water balance, glucose metabolism, pain, and response to stress), neuroprotection, and immunomodulation. We aim here to describe the recent advances on the role exerted by neuropeptides in the control of autophagy and its molecular mechanisms since increasing evidence indicates that dysregulation of autophagic process is related to different pathological conditions, including neurodegeneration, metabolic disorders, and cancer.
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Parvin R, Saito-Hakoda A, Shimada H, Shimizu K, Noro E, Iwasaki Y, Fujiwara K, Yokoyama A, Sugawara A. Role of NeuroD1 on the negative regulation of Pomc expression by glucocorticoid. PLoS One 2017; 12:e0175435. [PMID: 28406939 PMCID: PMC5391015 DOI: 10.1371/journal.pone.0175435] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 03/24/2017] [Indexed: 01/20/2023] Open
Abstract
The mechanism of the negative regulation of proopiomelanocortin gene (Pomc) by glucocorticoids (Gcs) is still unclear in many points. Here, we demonstrated the involvement of neurogenic differentiation factor 1 (NeuroD1) in the Gc-mediated negative regulation of Pomc. Murine pituitary adrenocorticotropic hormone (ACTH) producing corticotroph tumor-derived AtT20 cells were treated with dexamethasone (DEX) (1-100 nM) and cultured for 24 hrs. Thereafter, Pomc mRNA expression was studied by quantitative real-time PCR and rat Pomc promoter (-703/+58) activity was examined by luciferase assay. Both Pomc mRNA expression and Pomc promoter activity were inhibited by DEX in a dose-dependent manner. Deletion and point mutant analyses of Pomc promoter suggested that the DEX-mediated transcriptional repression was mediated via E-box that exists at -376/-371 in the promoter. Since NeuroD1 is known to bind to and activate E-box of the Pomc promoter, we next examined the effect of DEX on NeuroD1 expression. Interestingly, DEX dose-dependently inhibited NeuroD1 mRNA expression, mouse NeuroD1 promoter (-2.2-kb) activity, and NeuroD1 protein expression in AtT20 cells. In addition, we confirmed the inhibitory effect of DEX on the interaction of NeuroD1 and E-box on Pomc promoter by chromatin immunoprecipitation (ChIP) assay. Finally, overexpression of mouse NeuroD1 could rescue the DEX-mediated inhibition of Pomc mRNA expression and Pomc promoter activity. Taken together, it is suggested that the suppression of NeuroD1 expression and the inhibition of NeuroD1/E-box interaction may play an important role in the Gc-mediated negative regulation of Pomc.
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Affiliation(s)
- Rehana Parvin
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Akiko Saito-Hakoda
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Hiroki Shimada
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Kyoko Shimizu
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Erika Noro
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | | | - Ken Fujiwara
- Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University School of Medicine, Tochigi, Japan
| | - Atsushi Yokoyama
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Akira Sugawara
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
- * E-mail:
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Wang L, Zhang B, Huang F, Liu B, Xie Y. Curcumin inhibits lipolysis via suppression of ER stress in adipose tissue and prevents hepatic insulin resistance. J Lipid Res 2016; 57:1243-55. [PMID: 27220352 PMCID: PMC4918853 DOI: 10.1194/jlr.m067397] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Indexed: 11/20/2022] Open
Abstract
Curcumin is natural polyphenol with beneficial effects on lipid and glucose metabolism and this study aimed to investigate the effects of curcumin on lipolysis and hepatic insulin resistance. Endoplasmic reticulum (ER) stress and lipolysis signaling in adipose and FFA influx, lipid deposits, and glucose production in liver were examined. Palmitate challenge and high-fat diet feeding evoked ER stress-associated lipolysis with cAMP accumulation in adipose tissue. Curcumin treatment inhibited adipose tissue ER stress by dephosphorylation of inositol-requiring enzyme 1α and eukaryotic initiation factor 2α and reduced cAMP accumulation by preserving phosphodiesterase 3B induction. Knockdown of mitogen-activated protein kinase α1/2α with siRNAs diminished such effects of curcumin. As a result from downregulation of cAMP, curcumin blocked protein kinase (PK)A/hormone-sensitive lipase lipolysis signaling, and thereby reduced glycerol and FFA release from adipose tissue. Curcumin reduced FFA influx into the liver by blocking FFA trafficking, and then prevented diacylglycerol deposits and PKCε translocation in the liver, resultantly improving insulin action in the suppression of hepatic gluconeogenesis. Curcumin decreased adipose lipolysis by attenuating ER stress through the cAMP/PKA pathway, reduced FFA influx into the liver by blocking FFA trafficking, and thereby improved insulin sensitivity to inhibit hepatic glucose production. These findings suggested a novel pathway of curcumin to prevent lipid deposits and insulin resistance in liver by beneficial regulation of adipose function.
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Affiliation(s)
- Lulu Wang
- Jiangsu Key Laboratory of Traditional Chinese Medicine Evaluation and Translational Research, Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, China State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Bangling Zhang
- Jiangsu Key Laboratory of Traditional Chinese Medicine Evaluation and Translational Research, Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, China
| | - Fang Huang
- Jiangsu Key Laboratory of Traditional Chinese Medicine Evaluation and Translational Research, Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, China
| | - Baolin Liu
- Jiangsu Key Laboratory of Traditional Chinese Medicine Evaluation and Translational Research, Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, China
| | - Yuan Xie
- Jiangsu Key Laboratory of Traditional Chinese Medicine Evaluation and Translational Research, Department of Pharmacology of Chinese Materia Medica, China Pharmaceutical University, Nanjing, China Key Laboratory of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing, China
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