1
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Ntambi JN, Kalyesubula M, Cootway D, Lewis SA, Phang YX, Liu Z, O'Neill LM, Lefers L, Huff H, Miller JR, Pegkou Christofi V, Anderson E, Aljohani A, Mutebi F, Dutta M, Patterson A, Ntambi JM. Hepatic stearoyl-CoA desaturase-1 deficiency induces fibrosis and hepatocellular carcinoma-related gene activation under a high carbohydrate low fat diet. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159538. [PMID: 39067685 DOI: 10.1016/j.bbalip.2024.159538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 07/09/2024] [Accepted: 07/23/2024] [Indexed: 07/30/2024]
Abstract
Stearoyl-CoA desaturase-1 (SCD1) is a pivotal enzyme in lipogenesis, which catalyzes the synthesis of monounsaturated fatty acids (MUFA) from saturated fatty acids, whose ablation downregulates lipid synthesis, preventing steatosis and obesity. Yet deletion of SCD1 promotes hepatic inflammation and endoplasmic reticulum stress, raising the question of whether hepatic SCD1 deficiency promotes further liver damage, including fibrosis. To delineate whether SCD1 deficiency predisposes the liver to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC), we employed in vivo SCD1 deficient global and liver-specific mouse models fed a high carbohydrate low-fat diet and in vitro established AML12 mouse cells. The absence of liver SCD1 remarkably increased the saturation of liver lipid species, as indicated by lipidomic analysis, and led to hepatic fibrosis. Consistently, SCD1 deficiency promoted hepatic gene expression related to fibrosis, cirrhosis, and HCC. Deletion of SCD1 increased the circulating levels of Osteopontin, known to be increased in fibrosis, and alpha-fetoprotein, often used as an early marker and a prognostic marker for patients with HCC. De novo lipogenesis or dietary supplementation of oleate, an SCD1-generated MUFA, restored the gene expression related to fibrosis, cirrhosis, and HCC. Although SCD1 deficient mice are protected against obesity and fatty liver, our results show that MUFA deprivation results in liver injury, including fibrosis, thus providing novel insights between MUFA insufficiency and pathways leading to fibrosis, cirrhosis, and HCC under lean non-steatotic conditions.
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Affiliation(s)
- Jayne-Norah Ntambi
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA; Tufts Medical Center, Radiation Oncology, 800 Washington St., Box 359, Boston, MA 02111, USA
| | - Mugagga Kalyesubula
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Dylan Cootway
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Sarah A Lewis
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Yar Xin Phang
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Zhaojin Liu
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Lucas M O'Neill
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Lucas Lefers
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Hailey Huff
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Jacqueline Rose Miller
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Veronica Pegkou Christofi
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Ethan Anderson
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Ahmed Aljohani
- College of Science and Health Professions, King Saud Bin Abdulaziz University for Health Sciences, Riyadh 11564, Saudi Arabia; King Abdullah International Medical Research Center (KAIMRC), Riyadh 11564, Saudi Arabia
| | - Francis Mutebi
- School of Veterinary Medicine and Animal Resources, College of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda
| | - Mainak Dutta
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary & Biomedical Sciences, University Park, PA 16802, United States; Department of Biotechnology, Birla Institute of Technology and Science (BITS) Pilani Dubai Campus, Academic City, Dubai 345055, United Arab Emirates
| | - Andrew Patterson
- Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary & Biomedical Sciences, University Park, PA 16802, United States; The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, United States
| | - James M Ntambi
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA; Department of Nutritional Sciences, University of Wisconsin-Madison, 1415 Linden Drive, Madison, WI 53706, USA.
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2
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Igal RA. Death and the desaturase: implication of Stearoyl-CoA desaturase-1 in the mechanisms of cell stress, apoptosis, and ferroptosis. Biochimie 2024:S0300-9084(24)00125-1. [PMID: 38823621 DOI: 10.1016/j.biochi.2024.05.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 05/05/2024] [Accepted: 05/29/2024] [Indexed: 06/03/2024]
Abstract
Growth and proliferation of normal and cancerous cells necessitate a finely-tuned regulation of lipid metabolic pathways to ensure the timely supply of structural, energetic, and signaling lipid molecules. The synthesis and remodeling of lipids containing fatty acids with an appropriate carbon length and insaturation level are required for supporting each phase of the mechanisms of cell replication and survival. Mammalian Stearoyl-CoA desaturases (SCD), particularly SCD1, play a crucial role in modulating the fatty acid composition of cellular lipids, converting saturated fatty acids (SFA) into monounsaturated fatty acids (MUFA) in the endoplasmic reticulum (ER). Extensive research has elucidated in great detail the participation of SCD1 in the molecular mechanisms that govern cell replication in normal and cancer cells. More recently, investigations have shed new light on the functional and regulatory role of the Δ9-desaturase in the processes of cell stress and cell death. This review will examine the latest findings on the involvement of SCD1 in the molecular pathways of cell survival, particularly on the mechanisms of ER stress and autophagy, as well in apoptotic and non-apoptotic cell death.
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Affiliation(s)
- R Ariel Igal
- Institute of Human Nutrition and Department of Pediatrics, Columbia University Irving Medical Center, New York City, New York.
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3
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Ntambi JM, Liu X, Burhans MS, ALjohani A, Selen ES, Kalyesubula M, Assadi-Porter F. Hepatic oleate regulates one-carbon metabolism during high carbohydrate feeding. Biochem Biophys Res Commun 2023; 651:62-69. [PMID: 36791500 PMCID: PMC9992055 DOI: 10.1016/j.bbrc.2023.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 01/30/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023]
Abstract
Obesity is a major risk factor for type 2 diabetes, coronary heart disease, and strok. These diseases are associated with profound alterations in gene expression in metabolic tissues. Epigenetic-mediated regulation of gene expression is one mechanism through which environmental factors, such as diet, modify gene expression and disease predisposition. However, epigenetic control of gene expression in obesity and insulin resistance is not fully characterized. We discovered that liver-specific stearoyl-CoA desaturase-1 (Scd1) knockout mice (LKO) fed a high-carbohydrate low-fat diet exhibit dramatic changes in hepatic gene expression and metabolites of the folate cycle and one-carbon metabolism respectively for the synthesis of S-adenosylmethionine (SAM). LKO mice show an increased ratio of S-adenosylmethionine to S-adenosylhomocysteine, a marker for increased cellular methylation capacity. Furthermore, expression of DNA and histone methyltransferase genes is up-regulated while the mRNA and protein levels of the non-DNA methyltransferases including phosphatidylethanolamine methyltransferase (PEMT), Betaine homocysteine methyltransferase (Bhmt), and the SAM-utilizing enzymes such as glycine-N-methyltransferase (Gnmt) and guanidinoacetate methyltransferase (Gamt) are generally down-regulated. Feeding LKO mice a high carbohydrate diet supplemented with triolein, but not tristearin, and increased endogenous hepatic synthesis of oleate but not palmitoleate in Scd1 global knockout mice normalized one carbon gene expression and metabolite levels. Additionally, changes in one carbon gene expression are independent of the PGC-1α-mediated ER stress response previously reported in the LKO mice. Together, these results highlight the important role of oleate in maintaining one-carbon cycle homeostasis and point to observed changes in one-carbon metabolism as a novel mediator of the Scd1 deficiency-induced liver phenotype.
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Affiliation(s)
- James M Ntambi
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA; Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA.
| | - Xueqing Liu
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Maggie S Burhans
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Ahmed ALjohani
- College of Science and Health Professions, King Saudi Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia; King Abdullah International Medical Research Center (KAIMRC), Riyadh, Saudi Arabia
| | - Ebru Selin Selen
- Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Mugagga Kalyesubula
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Fariba Assadi-Porter
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA; Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
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4
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Ntambi JM. The role of Stearoyl-CoA desaturase in hepatic de novo lipogenesis. Biochem Biophys Res Commun 2022; 633:81-83. [DOI: 10.1016/j.bbrc.2022.08.092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Accepted: 08/30/2022] [Indexed: 11/06/2022]
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5
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O’Neill LM, Phang YX, Liu Z, Lewis SA, Aljohani A, McGahee A, Wade G, Kalyesubula M, Simcox J, Ntambi JM. Hepatic Oleate Regulates Insulin-like Growth Factor-Binding Protein 1 Partially through the mTORC1-FGF21 Axis during High-Carbohydrate Feeding. Int J Mol Sci 2022; 23:14671. [PMID: 36498997 PMCID: PMC9737156 DOI: 10.3390/ijms232314671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/13/2022] [Accepted: 11/14/2022] [Indexed: 11/25/2022] Open
Abstract
Stearoyl-CoA desaturase-1 (SCD1) catalyzes the rate-liming step of monounsaturated fatty acid biosynthesis and is a key regulator of systemic glucose metabolism. Mice harboring either a global (GKO) or liver-specific deletion (LKO) of Scd1 display enhanced insulin signaling and whole-body glucose uptake. Additionally, GKO and LKO mice are protected from high-carbohydrate diet-induced obesity. Given that high-carbohydrate diets can lead to chronic metabolic diseases such as obesity, diabetes, and hepatic steatosis, it is critical to understand how Scd1 deficiency confers metabolically beneficial phenotypes. Here we show that insulin-like growth factor-binding protein 1 (IGFBP1), a hepatokine that has been reported to enhance insulin signaling, is significantly elevated in the liver and plasma of GKO and LKO mice fed a low-fat high-carbohydrate diet. We also observed that the expression of hepatic Igfbp1 is regulated by oleic acid (18:1n9), a product of SCD1, through the mTORC1-FGF21 axis both in vivo and in vitro.
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Affiliation(s)
- Lucas M. O’Neill
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Yar Xin Phang
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Zhaojin Liu
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Sarah A. Lewis
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Ahmed Aljohani
- College of Science and Health Professions, King Saud Bin Abdulaziz University for Health Sciences, Riyadh 11564, Saudi Arabia
- King Abdullah International Medical Research Center (KAIMRC), Riyadh 11564, Saudi Arabia
| | - Ayren McGahee
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Gina Wade
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Mugagga Kalyesubula
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
| | - Judith Simcox
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
- Department of Nutritional Sciences, University of Wisconsin-Madison, 1415 Linden Drive, Madison, WI 53706, USA
| | - James M. Ntambi
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Drive, Madison, WI 53706, USA
- Department of Nutritional Sciences, University of Wisconsin-Madison, 1415 Linden Drive, Madison, WI 53706, USA
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6
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Ethanol Extract of Licorice Alleviates HFD-Induced Liver Fat Accumulation in Association with Modulation of Gut Microbiota and Intestinal Metabolites in Obesity Mice. Nutrients 2022; 14:nu14194180. [PMID: 36235833 PMCID: PMC9572531 DOI: 10.3390/nu14194180] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/29/2022] [Accepted: 10/01/2022] [Indexed: 11/06/2022] Open
Abstract
As a traditional Chinese medicine, licorice is often used in functional foods for its health benefits. However, the role of gut microbiota in the efficacy of licorice has not yet been fully elucidated. We hypothesized that the involvement of intestinal flora may be a key link in licorice ethanol extract (LEE)-induced health benefits. The aim of this study was to investigate whether LEE improves hepatic lipid accumulation in obese mice fed a high-fat diet (HFD) and whether the gut microbiota plays a key role in LEE treatment. Male C57BL/6J mice were fed HFD for liver fat accumulation and then treated with LEE. The same experiments were later performed using pseudo-sterile mice to verify the importance of gut flora. Supplementation with LEE improved the obesity profile, lipid profile and liver fat accumulation in HFD mice. In addition, LEE treatment improved intestinal flora dysbiosis caused by HFD in mice, as evidenced by a decrease in the percentage of Firmicutes/Bacteroidetes and an increase in the abundance of known anti-obesity-related bacteria. However, LEE failed to exhibit a therapeutic effect in pseudo-sterile mice. The results of the cellular assay showed that glycyrrhetic acid (GA), the main conversion product of glycyrrhizin (GL), was more effective in reducing fat accumulation and intracellular TG content in hepatocytes compared to GL. In conclusion, our data suggest that LEE attenuates obesity and hepatic fat accumulation in HFD mice, which may be associated with modulating the composition of gut microbiota and the conversion of LLE by the intestinal flora.
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7
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Deng KQ, Huang X, Lei F, Zhang XJ, Zhang P, She ZG, Cai J, Ji YX, Li H. Role of hepatic lipid species in the progression of nonalcoholic fatty liver disease. Am J Physiol Cell Physiol 2022; 323:C630-C639. [PMID: 35759443 DOI: 10.1152/ajpcell.00123.2022] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) has become the most common liver disease due to the global pandemic of metabolic diseases. Dysregulation of hepatic lipid metabolism plays a central role in the initiation and progression of NAFLD. With the advancement of lipidomics, an increasing number of lipid species and underlying mechanisms associating hepatic lipid components have been revealed. Therefore, the focus of this mini-review is to highlight the links between hepatic lipid species and their mechanisms mediating the pathogenesis of NAFLD. We first summarized the interplay between NAFLD and hepatic lipid disturbances. Next, we focused on reviewing the role of saturated fatty acids, cholesterol, oxidized phospholipids, and their respective intermediates in the pathogenesis of NAFLD. The mechanisms by which monounsaturated fatty acids and other pro-resolving mediators exert protective effects are also addressed. Finally, we further discussed the implication of different analysis approaches in lipidomic. Evolving insights into the pathophysiology of NAFLD will provide the opportunity for drug development.
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Affiliation(s)
- Ke-Qiong Deng
- Department of Cardiology, Center Hospital of Huanggang, Huanggang, China.,Huanggang Institute of Translation Medicine, Huanggang, China.,Department of Cardiology, Zhongnan Hospital of Wuhan University, Wuhan, China
| | - Xuewei Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Institute of Model Animal, Wuhan University, Wuhan, China
| | - Fang Lei
- Institute of Model Animal, Wuhan University, Wuhan, China.,School of Basic Medical Science, Wuhan University, Wuhan, China
| | - Xiao-Jing Zhang
- Institute of Model Animal, Wuhan University, Wuhan, China.,School of Basic Medical Science, Wuhan University, Wuhan, China
| | - Peng Zhang
- Institute of Model Animal, Wuhan University, Wuhan, China.,School of Basic Medical Science, Wuhan University, Wuhan, China
| | - Zhi-Gang She
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Institute of Model Animal, Wuhan University, Wuhan, China
| | - Jingjing Cai
- Department of Cardiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yan-Xiao Ji
- Institute of Model Animal, Wuhan University, Wuhan, China.,School of Basic Medical Science, Wuhan University, Wuhan, China
| | - Hongliang Li
- Huanggang Institute of Translation Medicine, Huanggang, China.,Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, China.,Institute of Model Animal, Wuhan University, Wuhan, China
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8
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Ratziu V, de Guevara L, Safadi R, Poordad F, Fuster F, Flores-Figueroa J, Arrese M, Fracanzani AL, Ben Bashat D, Lackner K, Gorfine T, Kadosh S, Oren R, Halperin M, Hayardeny L, Loomba R, Friedman S, Sanyal AJ. Aramchol in patients with nonalcoholic steatohepatitis: a randomized, double-blind, placebo-controlled phase 2b trial. Nat Med 2021; 27:1825-1835. [PMID: 34621052 DOI: 10.1038/s41591-021-01495-3] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 08/09/2021] [Indexed: 02/08/2023]
Abstract
Nonalcoholic steatohepatitis (NASH), a chronic liver disease without an approved therapy, is associated with lipotoxicity and insulin resistance and is a major cause of cirrhosis and hepatocellular carcinoma. Aramchol, a partial inhibitor of hepatic stearoyl-CoA desaturase (SCD1) improved steatohepatitis and fibrosis in rodents and reduced steatosis in an early clinical trial. ARREST, a 52-week, double-blind, placebo-controlled, phase 2b trial randomized 247 patients with NASH (n = 101, n = 98 and n = 48 in the Aramchol 400 mg, 600 mg and placebo arms, respectively; NCT02279524 ). The primary end point was a decrease in hepatic triglycerides by magnetic resonance spectroscopy at 52 weeks with a dose of 600 mg of Aramchol. Key secondary end points included liver histology and alanine aminotransferase (ALT). Aramchol 600 mg produced a placebo-corrected decrease in liver triglycerides without meeting the prespecified significance (-3.1, 95% confidence interval (CI) -6.4 to 0.2, P = 0.066), precluding further formal statistical analysis. NASH resolution without worsening fibrosis was achieved in 16.7% (13 out of 78) of Aramchol 600 mg versus 5% (2 out of 40) of the placebo arm (odds ratio (OR) = 4.74, 95% CI = 0.99 to 22.7) and fibrosis improvement by ≥1 stage without worsening NASH in 29.5% versus 17.5% (OR = 1.88, 95% CI = 0.7 to 5.0), respectively. The placebo-corrected decrease in ALT for 600 mg was -29.1 IU l-1 (95% CI = -41.6 to -16.5). Early termination due to adverse events (AEs) was <5%, and Aramchol 600 and 400 mg were safe, well tolerated and without imbalance in serious or severe AEs between arms. Although the primary end point of a reduction in liver fat did not meet the prespecified significance level with Aramchol 600 mg, the observed safety and changes in liver histology and enzymes provide a rationale for SCD1 modulation as a promising therapy for NASH and fibrosis and are being evaluated in an ongoing phase 3 program.
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Affiliation(s)
- V Ratziu
- Sorbonne Université, Institute for Cardiometabolism and Nutrition and Hôpital Pitié- Salpêtrière, INSERM UMRS 1138 CRC, Paris, France.
| | - L de Guevara
- Hospital Ángeles Clínica Londres, Mexico City, Mexico
| | - R Safadi
- Hadassah Medical Organization, Hadassah Hebrew University Medical Center, Jerusalem. The Holy Family Hospital, Nazareth, Israel
| | - F Poordad
- Texas Liver Institute/UT Health San Antonio San Antonio, San Antonio, TX, USA
| | - F Fuster
- Centro de Investigaciones Clinicas Viña del Mar, Viña del Mar, Chile
| | | | - M Arrese
- Departamento de Gastroenterología Facultad de Medicina Pontificia Universidad Católica de Chile Santiago Chile and Centro de Envejecimiento y Regeneración, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Anna L Fracanzani
- Department of Internal Medicine, Ca' Granda IRCCS Foundation, Policlinico Maggiore Hospital, University of Milan, Milan, Italy
| | - D Ben Bashat
- Sagol Brain Institute, Tel Aviv Sourasky Medical Center, Sackler Faculty of Medicine & Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - K Lackner
- Institute of Pathology, Medical University of Graz, Graz, Austria
| | - T Gorfine
- Galmed Pharmaceuticals Ltd, Tel-Aviv, Israel
| | - S Kadosh
- Statexcellence Ltd, Tel-Aviv, Israel
| | - R Oren
- Galmed Pharmaceuticals Ltd, Tel-Aviv, Israel
| | - M Halperin
- Galmed Pharmaceuticals Ltd, Tel-Aviv, Israel
| | - L Hayardeny
- Galmed Pharmaceuticals Ltd, Tel-Aviv, Israel
| | - R Loomba
- NAFLD Research Center, University of California at San Diego, La Jolla, CA, USA
| | - S Friedman
- Division of Liver Diseases, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Arun J Sanyal
- Department of Gastroenterology, Virginia Commonwealth University, Richmond, VA, USA
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9
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Tuthill II BF, Quaglia CJ, O'Hara E, Musselman LP. Loss of Stearoyl-CoA desaturase 1 leads to cardiac dysfunction and lipotoxicity. J Exp Biol 2021; 224:jeb240432. [PMID: 34423827 PMCID: PMC8502255 DOI: 10.1242/jeb.240432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 08/16/2021] [Indexed: 12/28/2022]
Abstract
Diets high in carbohydrates are associated with type 2 diabetes and its co-morbidities, including hyperglycemia, hyperlipidemia, obesity, hepatic steatosis and cardiovascular disease. We used a high-sugar diet to study the pathophysiology of diet-induced metabolic disease in Drosophila melanogaster. High-sugar diets produce hyperglycemia, obesity, insulin resistance and cardiomyopathy in flies, along with ectopic accumulation of toxic lipids, or lipotoxicity. Stearoyl-CoA desaturase 1 is an enzyme that contributes to long-chain fatty acid metabolism by introducing a double bond into the acyl chain. Knockdown of stearoyl-CoA desaturase 1 in the fat body reduced lipogenesis and exacerbated pathophysiology in flies reared on high-sucrose diets. These flies exhibited dyslipidemia and growth deficiency in addition to defects in cardiac and gut function. We assessed the lipidome of these flies using tandem mass spectrometry to provide insight into the relationship between potentially lipotoxic species and type 2 diabetes-like pathophysiology. Oleic acid supplementation is able to rescue a variety of phenotypes produced by stearoyl-CoA desaturase 1 RNAi, including fly mass, triglyceride storage, gut development and cardiac failure. Taken together, these data suggest a protective role for monounsaturated fatty acids in diet-induced metabolic disease phenotypes.
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10
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Dilworth L, Facey A, Omoruyi F. Diabetes Mellitus and Its Metabolic Complications: The Role of Adipose Tissues. Int J Mol Sci 2021; 22:ijms22147644. [PMID: 34299261 PMCID: PMC8305176 DOI: 10.3390/ijms22147644] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/08/2021] [Accepted: 07/12/2021] [Indexed: 12/14/2022] Open
Abstract
Many approaches have been used in the effective management of type 2 diabetes mellitus. A recent paradigm shift has focused on the role of adipose tissues in the development and treatment of the disease. Brown adipose tissues (BAT) and white adipose tissues (WAT) are the two main types of adipose tissues with beige subsets more recently identified. They play key roles in communication and insulin sensitivity. However, WAT has been shown to contribute significantly to endocrine function. WAT produces hormones and cytokines, collectively called adipocytokines, such as leptin and adiponectin. These adipocytokines have been proven to vary in conditions, such as metabolic dysfunction, type 2 diabetes, or inflammation. The regulation of fat storage, energy metabolism, satiety, and insulin release are all features of adipose tissues. As such, they are indicators that may provide insights on the development of metabolic dysfunction or type 2 diabetes and can be considered routes for therapeutic considerations. The essential roles of adipocytokines vis-a-vis satiety, appetite, regulation of fat storage and energy, glucose tolerance, and insulin release, solidifies adipose tissue role in the development and pathogenesis of diabetes mellitus and the complications associated with the disease.
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Affiliation(s)
- Lowell Dilworth
- Department of Pathology, Mona Campus, University of the West Indies, Kingston 7, Jamaica;
| | - Aldeam Facey
- Mona Academy of Sport, Mona Campus, University of the West Indies, Kingston 7, Jamaica;
| | - Felix Omoruyi
- Department of Life Sciences, Texas A&M University, Corpus Christi, TX 78412, USA
- Correspondence:
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11
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Zhao X, Wang M, Liu J, Su X. Stearoyl CoA Desaturase 1 and Inositol-Requiring Protein 1 α Determine the Efficiency of Oleic Acid in Alleviating Silica Nanoparticle-Induced Insulin Resistance. J Biomed Nanotechnol 2021; 17:1349-1363. [PMID: 34446138 DOI: 10.1166/jbn.2021.3109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Despite the widespread use of silica nanoparticles (SiNPs), their metabolic impact and mechanisms of action have not been well studied. Exposure to SiNPs induces insulin resistance (IR) in hepatocytes by endoplasmic reticulum (ER) stress via inositol-requiring protein 1α (IRE1α) activation of c-Jun N-terminal kinases (JNK). It has been well established that stearoyl CoA desaturase (SCD1) and its major product oleic acid elicited beneficial effects in restoring ER homeostasis. However, the potential coordination of SCD1 and IRE1α in determining SiNP regulation of insulin signaling is unclear. Herein, we investigated the effects of SCD1 and oleic acid on IR induced by SiNPs or thapsigargin in hepatocytes. SCD1 overexpression or oleic acid efficiently reversed SiNP-induced ER stress and IR, whereas the effects of thapsigargin treatment could not be restored. Thapsigargin diminished SCD1 protein levels, leading to the accumulation of IRE1α and sustained activation of the IRE1α/JNK pathway. Moreover, knockdown of activating transcription factor 4 (ATF4) upstream of SCD1 suppressed SiNP-induced SCD1 expression, rescued the activated IRE1α, and inhibited insulin signaling but was not able to restore the effects of thapsigargin. Collectively, downregulation of SCD1 and excess accumulation of IRE1α protein prevented the beneficial effects of exogenous oleic acid on IR induced by ER stress. Our results provide valuable mechanistic insights into the synergic regulation of IR by SiNPs and ER stress and suggest a combinational strategy to restore ER homeostasis by targeting SCD1 and IRE1α proteins, as well as supplementation of unsaturated fatty acids.
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Affiliation(s)
- Xiaoyang Zhao
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China
| | - Min Wang
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China
| | - Jingjing Liu
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China
| | - Xiong Su
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, 215123, China
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12
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Abstract
Non-alcoholic fatty liver disease (NAFLD) was defined in 1980 and has the same histological characteristics as alcoholic liver disease except for alcohol consumption. After 40 years, the understanding of this disease is still imperfect. Without specific drugs available for treatment, the number of patients with NAFLD is increasing rapidly, and NAFLD currently affects more than one-quarter of the global population. NAFLD is mostly caused by a sedentary lifestyle and excessive energy intake of fat and sugar. To ameliorate or avoid NAFLD, people commonly replace high-fat foods with high-carbohydrate foods (especially starchy carbohydrates) as a way to reduce caloric intake and reach satiety. However, there are few studies that concentrate on the effect of carbohydrate intake on liver metabolism in patients with NAFLD, much fewer than the studies on fat intake. Besides, most of these studies are not systematic, which has made identification of the mechanism difficult. In this review, we collected and analysed data from studies on human and animal models and, surprisingly, found that carbohydrates and liver steatosis could be linked by inflammation. This review not only describes the effects of carbohydrates on NAFLD and body lipid metabolism but also analyses and predicts possible molecular pathways of carbohydrates in liver lipid synthesis that involve inflammation. Furthermore, the limitations of recent research and possible targets for regulating inflammation and lipogenesis are discussed. This review describes the effects of starchy carbohydrates, a nutrient signal, on NAFLD from the perspective of inflammation.
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13
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Synthesis of a green bigel using cottonseed oil/cannabis oil/alginate/ferula gum for quercetin release: Synergistic effects for treating infertility in rats. Int J Biol Macromol 2021; 177:157-165. [PMID: 33609576 DOI: 10.1016/j.ijbiomac.2021.02.121] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/23/2021] [Accepted: 02/15/2021] [Indexed: 11/24/2022]
Abstract
Although therapeutic effect of quercetin (Quer) was reported on non-alcoholic fatty liver disease (NAFLD), destructive effects have been shown on male fertility due to its pro-oxidative properties. On the other hand, NAFLD impairs germ cells to produce sperm and leads to male infertility. Herein, a biocompatible and green bigel was designed for Quer delivery to prevent infertility induced by NAFLD as the increasing complications. Bigels were prepared using cottonseed oil/cannabis oil/alginate/ferula gum and optimized by the mixture design method. NAFLD was induced by 58% of dietary calorie as lard and 42 g/l fructose for 16 weeks in Sprague-Dawley rats. So on animals received 2 mg/kg Quer loaded on bigels, free bigels, or free Quer for 45 days as daily gavage. Semen was analyzed, followed by the assessment of DNA integrity. Count, motility, and normal morphology reached the healthy control group at the bigel-Quer-treated one. Moreover, all of these parameters were significantly higher in the bigel-Quer group than the Quer and bigel, alone. The percent of sperms with head and tail abnormality decreased considerably in the bigel-Quer group compared with the Quer, free bigel, and NAFLD groups. Serum testosterone levels significantly increased and reached the healthy control group in the bigel-Quer group. DNA fragmentation of sperm significantly decreased in the bigel-Quer group (p < 0.05). The bigel showed synergistic effects with Quer for treating infertility in rats with NAFLD.
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14
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Igal RA, Sinner DI. Stearoyl-CoA desaturase 5 (SCD5), a Δ-9 fatty acyl desaturase in search of a function. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1866:158840. [PMID: 33049404 DOI: 10.1016/j.bbalip.2020.158840] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/26/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022]
Abstract
A large body of research has demonstrated that human stearoyl-CoA desaturase 1 (SCD1), a universally expressed fatty acid Δ9-desaturase that converts saturated fatty acids (SFA) into monounsaturated fatty acids (MUFA), is a central regulator of metabolic and signaling pathways involved in cell proliferation, differentiation, and survival. Unlike SCD1, stearoyl-CoA desaturase 5 (SCD5), a second SCD isoform found in a variety of vertebrates, including humans, has received considerably less attention but new information on the catalytic properties, regulation and biological functions of this enzyme has begun to emerge. This review will examine the new evidence that supports key metabolic and biological roles for SCD5, as well as the potential implication of this desaturase in the mechanisms of human diseases.
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Affiliation(s)
- R Ariel Igal
- Institute of Human Nutrition and Department of Pediatrics, Columbia University Irving Medical Center, 630 West 168th Street, PH 1501 East, New York City, NY 10032, United States of America.
| | - Débora I Sinner
- Neonatology and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Lab: R4447, Office: R4445, MLC 7009, 3333 Burnet Ave, Cincinnati, OH 45229, United States of America.
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15
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Wu L, Mo W, Feng J, Li J, Yu Q, Li S, Zhang J, Chen K, Ji J, Dai W, Wu J, Xu X, Mao Y, Guo C. Astaxanthin attenuates hepatic damage and mitochondrial dysfunction in non-alcoholic fatty liver disease by up-regulating the FGF21/PGC-1α pathway. Br J Pharmacol 2020; 177:3760-3777. [PMID: 32446270 PMCID: PMC7393201 DOI: 10.1111/bph.15099] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 04/26/2020] [Accepted: 04/29/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE Non-alcoholic fatty liver disease (NAFLD) is considered to be one of the most common chronic liver diseases across worldwide. Astaxanthin (Ax) is a carotenoid, and beneficial effects of astaxanthin, including anti-oxidative, anti-inflammatory, and anti-tumour activity, have been identified. The present study aimed to elucidate the protective effect of astaxanthin against NAFLD and its underlying mechanism. EXPERIMENTAL APPROACH Mice were fed either a high fat or chow diet, with or without astaxanthin, for up to 12 weeks. L02 cells were treated with free fatty acids combined with different doses of astaxanthin for 48 h. Histopathology, expression of lipid metabolism, inflammation, apoptosis, and fibrosis-related gene expression were assessed. And the function of mitochondria was also evaluated. KEY RESULTS The results indicated that astaxanthin attenuated HFD- and FFA-induced lipid accumulation and its associated oxidative stress, cell apoptosis, inflammation, and fibrosis both in vivo and in vitro. Astaxanthin up-regulated FGF21 and PGC-1α expression in damaged hepatocytes, which suggested an unrecognized mechanism of astaxanthin on ameliorating NAFLD. CONCLUSION AND IMPLICATIONS Astaxanthin attenuated hepatocyte damage and mitochondrial dysfunction in NAFLD by up-regulating FGF21/PGC-1α pathway. Our results suggest that astaxanthin may become a promising drug to treat or relieve NAFLD.
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Affiliation(s)
- Liwei Wu
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
| | - Wenhui Mo
- Department of GastroenterologyShidong Hospital of ShanghaiShanghaiChina
| | - Jiao Feng
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
| | - Jingjing Li
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
- Department of Gastroenterology, Putuo People's HospitalTongji University School of MedicineShanghaiChina
| | - Qiang Yu
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
| | - Sainan Li
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
| | - Jie Zhang
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
- Shanghai Tenth HospitalSchool of Clinical Medicine of Nanjing Medical UniversityShanghaiChina
| | - Kan Chen
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
| | - Jie Ji
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
| | - Weiqi Dai
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
- Department of Gastroenterology, Putuo People's HospitalTongji University School of MedicineShanghaiChina
- Department of GastroenterologyZhongshan Hospital of Fudan UniversityShanghaiChina
- Shanghai Institute of Liver DiseasesZhongshan Hospital of Fudan UniversityShanghaiChina
- Shanghai Tongren HospitalShanghai Jiaotong University School of MedicineShanghaiChina
| | - Jianye Wu
- Department of Gastroenterology, Putuo People's HospitalTongji University School of MedicineShanghaiChina
| | - Xuanfu Xu
- Department of GastroenterologyShidong Hospital of ShanghaiShanghaiChina
| | - Yuqing Mao
- Department of Gastroenterology, Shanghai First People's HospitalShanghai Jiaotong University School of MedicineShanghaiChina
| | - Chuanyong Guo
- Department of Gastroenterology, Shanghai Tenth People's HospitalTongji University School of MedicineShanghaiChina
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16
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Sarabhai T, Kahl S, Szendroedi J, Markgraf DF, Zaharia OP, Barosa C, Herder C, Wickrath F, Bobrov P, Hwang JH, Jones JG, Roden M. Monounsaturated fat rapidly induces hepatic gluconeogenesis and whole-body insulin resistance. JCI Insight 2020; 5:134520. [PMID: 32434996 DOI: 10.1172/jci.insight.134520] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 04/09/2020] [Indexed: 01/21/2023] Open
Abstract
BACKGROUNDWhile saturated fat intake leads to insulin resistance and nonalcoholic fatty liver, Mediterranean-like diets enriched in monounsaturated fatty acids (MUFA) may have beneficial effects. This study examined effects of MUFA on tissue-specific insulin sensitivity and energy metabolism.METHODSA randomized placebo-controlled cross-over study enrolled 16 glucose-tolerant volunteers to receive either oil (OIL, ~1.18 g/kg), rich in MUFA, or vehicle (VCL, water) on 2 occasions. Insulin sensitivity was assessed during preclamp and hyperinsulinemic-euglycemic clamp conditions. Ingestion of 2H2O/acetaminophen was combined with [6,6-2H2]glucose infusion and in vivo 13C/31P/1H/ex vivo 2H-magnet resonance spectroscopy to quantify hepatic glucose and energy fluxes.RESULTSOIL increased plasma triglycerides and oleic acid concentrations by 44% and 66% compared with VCL. Upon OIL intervention, preclamp hepatic and whole-body insulin sensitivity markedly decreased by 28% and 27%, respectively, along with 61% higher rates of hepatic gluconeogenesis and 32% lower rates of net glycogenolysis, while hepatic triglyceride and ATP concentrations did not differ from VCL. During insulin stimulation hepatic and whole-body insulin sensitivity were reduced by 21% and 25%, respectively, after OIL ingestion compared with that in controls.CONCLUSIONA single MUFA-load suffices to induce insulin resistance but affects neither hepatic triglycerides nor energy-rich phosphates. These data indicate that amount of ingested fat, rather than its composition, primarily determines the development of acute insulin resistance.TRIAL REGISTRATIONClinicalTrials.gov NCT01736202.FUNDINGGerman Diabetes Center, German Federal Ministry of Health, Ministry of Culture and Science of the state of North Rhine-Westphalia, German Federal Ministry of Education and Research, German Diabetes Association, German Center for Diabetes Research, Portugal Foundation for Science and Technology, European Regional Development Fund, and Rede Nacional de Ressonancia Magnética Nuclear.
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Affiliation(s)
- Theresia Sarabhai
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Sabine Kahl
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Julia Szendroedi
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Daniel F Markgraf
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Oana-Patricia Zaharia
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Cristina Barosa
- Centre for Neurosciences and Cell Biology, UC Biotech, Cantanhede, Portugal.,Portuguese Diabetes Association, Lisbon, Portugal
| | - Christian Herder
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Frithjof Wickrath
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - Pavel Bobrov
- German Center for Diabetes Research, München-Neuherberg, Germany.,Institute for Biometrics and Epidemiology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Jong-Hee Hwang
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany
| | - John Griffith Jones
- Centre for Neurosciences and Cell Biology, UC Biotech, Cantanhede, Portugal.,Portuguese Diabetes Association, Lisbon, Portugal
| | - Michael Roden
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University Düsseldorf, Düsseldorf, Germany.,German Center for Diabetes Research, München-Neuherberg, Germany.,Division of Endocrinology and Diabetology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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17
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Nonalcoholic Fatty Liver Disease: A Challenge from Mechanisms to Therapy. J Clin Med 2019; 9:jcm9010015. [PMID: 31861591 PMCID: PMC7019297 DOI: 10.3390/jcm9010015] [Citation(s) in RCA: 101] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/05/2019] [Accepted: 12/16/2019] [Indexed: 12/11/2022] Open
Abstract
Focusing on previously published mechanisms of non-alcoholic fatty liver disease (NAFLD), their uncertainty does not always permit a clear elucidation of the grassroot alterations that are at the basis of the wide-spread illness, and thus curing it is still a challenge. There is somehow exceptional progress, but many controversies persist in NAFLD research and clinical investigation. It is likely that hidden mechanisms will be brought to light in the near future. Hereby, the authors present, with some criticism, classical mechanisms that stand at the basis of NAFLD, and consider contextually different emerging processes. Without ascertaining these complex interactions, investigators have a long way left ahead before finding an effective therapy for NAFLD beyond diet and exercise.
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18
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Kikuchi K, Tsukamoto H. Stearoyl-CoA desaturase and tumorigenesis. Chem Biol Interact 2019; 316:108917. [PMID: 31838050 DOI: 10.1016/j.cbi.2019.108917] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 12/09/2019] [Indexed: 01/07/2023]
Abstract
Stearoyl-CoA desaturase (SCD) generates monounsaturated fatty acids (MUFAs) which contribute to cell growth, survival, differentiation, metabolic regulation and signal transduction. Overexpression of SCD is evident and implicated in metabolic diseases such as diabetes and non-alcoholic fatty liver disease. SCD also stimulates canonical Wnt pathway and YAP activation in support of stemness and tumorigenesis. SCD facilitates metabolic reprogramming in cancer which is mediated, at least in part, by regulation of AKT, AMPK, and NF-kB via MUFAs. Our research has revealed the novel positive loop to amplify Wnt signaling through stabilization of LRP5/6 in both hepatic stellate cells and liver tumor-initiating stem cell-like cells. As such, this loop is pivotal in promoting liver fibrosis and liver tumor development. This review summarizes the mechanisms of SCD-mediated tumor promotion described by recent studies and discusses the future prospect for SCD-mediated signaling crosstalk as a potential therapeutic target for cancer.
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Affiliation(s)
- Kohtaro Kikuchi
- Southern California Research Center for ALPD and Cirrhosis and Department of Pathology, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
| | - Hidekazu Tsukamoto
- Southern California Research Center for ALPD and Cirrhosis and Department of Pathology, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA.
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19
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Aljohani A, Khan MI, Bonneville A, Guo C, Jeffery J, O'Neill L, Syed DN, Lewis SA, Burhans M, Mukhtar H, Ntambi JM. Hepatic stearoyl CoA desaturase 1 deficiency increases glucose uptake in adipose tissue partially through the PGC-1α-FGF21 axis in mice. J Biol Chem 2019; 294:19475-19485. [PMID: 31690632 DOI: 10.1074/jbc.ra119.009868] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/22/2019] [Indexed: 12/15/2022] Open
Abstract
Increased carbohydrate consumption increases hepatic de novo lipogenesis, which has been linked to the development of chronic metabolic diseases, including obesity, hepatic steatosis, and insulin resistance. Stearoyl CoA desaturase 1 (SCD1) is a critical lipogenic enzyme that catalyzes the synthesis of two monounsaturated fatty acids, oleate and palmitoleate, from the saturated fatty acids stearate and palmitate, respectively. SCD1-deficient mouse models are protected against diet-induced adiposity, hepatic steatosis, and hyperglycemia. However, the mechanism of this protection by SCD1 deficiency is unclear. Using liver-specific SCD1 knockout (LKO) mice fed a high-carbohydrate, low-fat diet, we show that hepatic SCD1 deficiency increases systemic glucose uptake. Hepatic SCD1 deficiency enhanced glucose transporter type 1 (GLUT1) expression in the liver and also up-regulated GLUT4 and adiponectin expression in adipose tissue. The enhanced glucose uptake correlated with increased liver expression and elevated plasma levels of fibroblast growth factor 21 (FGF21), a hepatokine known to increase systemic insulin sensitivity and regulate whole-body lipid metabolism. Feeding LKO mice a triolein-supplemented but not tristearin-supplemented high-carbohydrate, low-fat diet reduced FGF21 expression and plasma levels. Consistently, SCD1 inhibition in primary hepatocytes induced FGF21 expression, which was repressed by treatment with oleate but not palmitoleate. Moreover, deletion of the transcriptional coactivator PPARγ coactivator 1α (PGC-1α) reduced hepatic and plasma FGF21 and white adipocyte tissue-specific GLUT4 expression and raised plasma glucose levels in LKO mice. These results suggest that hepatic oleate regulates glucose uptake in adipose tissue either directly or partially by modulating the hepatic PGC-1α-FGF21 axis.
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Affiliation(s)
- Ahmed Aljohani
- Endocrinology and Reproductive Physiology Graduate Training Program, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin 53706.,College of Science and Health Professions, King Saud bin Abdulaziz University for Health Sciences, Riyadh 11481, Saudi Arabia
| | - Mohammad Imran Khan
- School of Medicine and Public Health, Department of Dermatology, University of Wisconsin, Madison, Wisconsin 53706.,Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Abram Bonneville
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Changan Guo
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Justin Jeffery
- Carbone Cancer Center, University of Wisconsin, Madison, Wisconsin 53706
| | - Lucas O'Neill
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Deeba Nadeem Syed
- School of Medicine and Public Health, Department of Dermatology, University of Wisconsin, Madison, Wisconsin 53706
| | - Sarah A Lewis
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Maggie Burhans
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin 53706
| | - Hasan Mukhtar
- School of Medicine and Public Health, Department of Dermatology, University of Wisconsin, Madison, Wisconsin 53706
| | - James M Ntambi
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706 .,Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin 53706
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20
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Hepatic Stearoyl-CoA desaturase-1 deficiency-mediated activation of mTORC1- PGC-1α axis regulates ER stress during high-carbohydrate feeding. Sci Rep 2019; 9:15761. [PMID: 31673045 PMCID: PMC6823547 DOI: 10.1038/s41598-019-52339-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 10/15/2019] [Indexed: 12/15/2022] Open
Abstract
Stearoyl CoA desaturase 1 (SCD1) is a key enzyme in lipogenesis as it catalyzes the synthesis of monounsaturated fatty acids (MUFAs), mainly oleate (18:1n9) and palmitoleate (16:1n7) from saturated fatty acids (SFA), stearate (18:0) and palmitate (16:0), respectively. Studies on SCD1 deficiency in mouse models demonstrated beneficial metabolic phenotypes such as reduced adiposity and improved glucose tolerance. Even though, SCD1 represents a potential target to resolve obesity related metabolic diseases; SCD1 deficiency causes endoplasmic reticulum (ER) stress and activates unfolded protein response (UPR). The induction of ER stress in response to SCD1 deficiency is governed by the cofactor, PGC-1α. However, the mechanism by which SCD1 deficiency increases PGC-1α and subsequently induces ER stress still remains elusive. The present study demonstrates that despite reduced lipogenesis, liver specific SCD1 deficiency activates the mechanistic target of rapamycin complex 1 (mTORC1) along with induction of PGC-1α and ER stress. Further, mTORC1 inhibition attenuates SCD1 deficiency-mediated induction of both PGC-1α and ER stress. Similar observations were seen by restoring endogenously synthesized oleate, but not palmitoleate, suggesting a clear mTORC1-mediated regulation of ER stress during SCD1 deficiency. Overall, our results suggest a model whereby maintaining adequate levels of hepatic oleate is required to suppress mTORC1-mediated ER stress. In addition, the activation of mTORC1 by SCD1 deficiency reveals an important function of fatty acids in regulating different cellular processes through mTORC1 signaling.
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21
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Hernández-Saavedra D, Stanford KI. The Regulation of Lipokines by Environmental Factors. Nutrients 2019; 11:E2422. [PMID: 31614481 PMCID: PMC6835582 DOI: 10.3390/nu11102422] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 10/06/2019] [Accepted: 10/09/2019] [Indexed: 01/08/2023] Open
Abstract
Adipose tissue is a highly metabolically-active tissue that senses and secretes hormonal and lipid mediators that facilitate adaptations to metabolic tissues. In recent years, the role of lipokines, which are lipid species predominantly secreted from adipose tissue that act as hormonal regulators in many metabolic tissues, has been an important area of research for obesity and diabetes. Previous studies have identified that these secreted lipids, including palmitoleate, 12,13-diHOME, and fatty acid-hydroxy-fatty acids (FAHFA) species, are important regulators of metabolism. Moreover, environmental factors that directly affect the secretion of lipokines such as diet, exercise, and exposure to cold temperatures constitute attractive therapeutic strategies, but the mechanisms that regulate lipokine stimulation have not been thoroughly reviewed. In this study, we will discuss the chemical characteristics of lipokines that position them as attractive targets for chronic disease treatment and prevention and the emerging roles of lipokines as regulators of inter-tissue communication. We will define the target tissues of lipokines, and explore the ability of lipokines to prevent or delay the onset and development of chronic diseases. Comprehensive understanding of the lipokine synthesis and lipokine-driven regulation of metabolic outcomes is instrumental for developing novel preventative and therapeutic strategies that harness adipose tissue-derived lipokines.
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Affiliation(s)
- Diego Hernández-Saavedra
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.
| | - Kristin I Stanford
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.
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22
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Benhammou JN, Ko A, Alvarez M, Kaikkonen MU, Rankin C, Garske KM, Padua D, Bhagat Y, Kaminska D, Kärjä V, Pihlajamäki J, Pisegna JR, Pajukanta P. Novel Lipid Long Intervening Noncoding RNA, Oligodendrocyte Maturation-Associated Long Intergenic Noncoding RNA, Regulates the Liver Steatosis Gene Stearoyl-Coenzyme A Desaturase As an Enhancer RNA. Hepatol Commun 2019; 3:1356-1372. [PMID: 31592021 PMCID: PMC6771395 DOI: 10.1002/hep4.1413] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 07/10/2019] [Indexed: 12/15/2022] Open
Abstract
The global obesity epidemic is driving the concomitant rise in nonalcoholic fatty liver disease (NAFLD). To identify new genes involved in central liver functions, we examined liver RNA‐sequence data from 259 patients who underwent morbidly obese bariatric surgery. Of these patients, 84 had normal liver histology, 40 simple steatosis, 43 nonalcoholic steatohepatitis, and the remaining 92 patients had varying degrees of NAFLD based on liver histology. We discovered oligodendrocyte maturation‐associated long intergenic noncoding RNA (OLMALINC), a long intervening noncoding RNA (lincRNA) in a human liver co‐expression network (n = 75 genes) that was strongly associated with statin use and serum triglycerides (TGs). OLMALINC liver expression was highly correlated with the expression of known cholesterol biosynthesis genes and stearoyl‐coenzyme A desaturase (SCD). SCD is the rate‐limiting enzyme in monounsaturated fatty acids and a key TG gene that is known to be up‐regulated in liver steatosis and NAFLD and resides adjacent to OLMALINC on the human chromosome 10q24.31. Next, we functionally demonstrated that OLMALINC regulates SCD as an enhancer‐RNA (eRNA), thus describing the first lincRNA that functions as an eRNA to regulate lipid metabolism. Specifically, we show that OLMALINC promotes liver expression of SCD in cis through regional chromosomal DNA–DNA looping interactions. Conclusion: The primate‐specific lincRNA OLMALINC is a novel epigenetic regulator of the key TG and NAFLD gene SCD.
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Affiliation(s)
- Jihane N Benhammou
- Vatche and Tamar Manoukian Division of Digestive Diseases University of California Los Angeles Los Angeles CA.,Department of Human Genetics David Geffen School of Medicine at University of California Los Angeles Los Angeles CA.,Division of Gastroenterology, Hepatology, and Parenteral Nutrition, Department of Medicine Veterans Administration Greater Los Angeles Healthcare System Los Angeles CA
| | - Arthur Ko
- Department of Medicine David Geffen School of Medicine at University of California Los Angeles Los Angeles CA
| | - Marcus Alvarez
- Department of Human Genetics David Geffen School of Medicine at University of California Los Angeles Los Angeles CA
| | - Minna U Kaikkonen
- Institute of Public Health and Clinical Nutrition University of Eastern Finland Kuopio Finland
| | - Carl Rankin
- Vatche and Tamar Manoukian Division of Digestive Diseases University of California Los Angeles Los Angeles CA
| | - Kristina M Garske
- Department of Human Genetics David Geffen School of Medicine at University of California Los Angeles Los Angeles CA
| | - David Padua
- Vatche and Tamar Manoukian Division of Digestive Diseases University of California Los Angeles Los Angeles CA.,Division of Gastroenterology, Hepatology, and Parenteral Nutrition, Department of Medicine Veterans Administration Greater Los Angeles Healthcare System Los Angeles CA
| | - Yash Bhagat
- Department of Human Genetics David Geffen School of Medicine at University of California Los Angeles Los Angeles CA
| | - Dorota Kaminska
- Department of Human Genetics David Geffen School of Medicine at University of California Los Angeles Los Angeles CA.,Institute of Public Health and Clinical Nutrition University of Eastern Finland Kuopio Finland
| | - Vesa Kärjä
- Department of Clinical Pathology Kuopio University Hospital Kuopio Finland
| | - Jussi Pihlajamäki
- Institute of Public Health and Clinical Nutrition University of Eastern Finland Kuopio Finland.,Clinical Nutrition and Obesity Center Kuopio University Hospital Kuopio Finland
| | - Joseph R Pisegna
- Department of Human Genetics David Geffen School of Medicine at University of California Los Angeles Los Angeles CA.,Division of Gastroenterology, Hepatology, and Parenteral Nutrition, Department of Medicine Veterans Administration Greater Los Angeles Healthcare System Los Angeles CA
| | - Päivi Pajukanta
- Department of Human Genetics David Geffen School of Medicine at University of California Los Angeles Los Angeles CA.,Bioinformatics Interdepartmental Program University of California Los Angeles Los Angeles CA.,Institute for Precision Health of University of California Los Angeles Los Angeles CA
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23
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Finck BN. Targeting Metabolism, Insulin Resistance, and Diabetes to Treat Nonalcoholic Steatohepatitis. Diabetes 2018; 67:2485-2493. [PMID: 30459251 PMCID: PMC6245219 DOI: 10.2337/dbi18-0024] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Accepted: 09/20/2018] [Indexed: 12/25/2022]
Abstract
Obesity, insulin resistance, and diabetes are strongly linked to the accumulation of excessive lipids in the liver parenchyma, a condition known as nonalcoholic fatty liver disease (NAFLD). Given its association with obesity and related metabolic diseases, it is not surprising that the prevalence of NAFLD has dramatically increased in the past few decades. NAFLD has become the most common liver disease in many areas of the world. The term, NAFLD, encompasses a spectrum of disorders that ranges from simple steatosis to steatosis with inflammatory lesions (nonalcoholic steatohepatitis [NASH]). Although simple steatosis might be relatively benign, epidemiologic studies have linked NASH to greatly increased risk of developing cirrhosis and hepatocellular carcinoma. Yet despite this, there are no approved treatments for the disease, and it remains a significant unmet medical need. This Perspective will review some of the relevant literature on the topic and examine approved and experimental NASH therapeutic concepts that target intermediary metabolism, insulin resistance, and diabetes to treat this emerging public health problem.
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Affiliation(s)
- Brian N Finck
- Center for Human Nutrition, Division of Geriatrics and Nutritional Sciences, John T. Milliken Department of Medicine, Washington University School of Medicine in St. Louis, St. Louis, MO
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24
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Carnuta MG, Deleanu M, Barbalata T, Toma L, Raileanu M, Sima AV, Stancu CS. Zingiber officinale extract administration diminishes steroyl-CoA desaturase gene expression and activity in hyperlipidemic hamster liver by reducing the oxidative and endoplasmic reticulum stress. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2018; 48:62-69. [PMID: 30195881 DOI: 10.1016/j.phymed.2018.04.059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 03/15/2018] [Accepted: 04/26/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Stearoyl CoA desaturases (SCD) are enzymes that convert saturated to monounsaturated fatty acids and have increased activity in hepatic steatosis. PURPOSE We aimed to investigate the potential of ginger extract (GIN) to modulate the liver SCD1 expression and activity in hyperlipidemic (HL) conditions, in order to lower lipid accumulation in the steatotic liver. STUDY DESIGN/METHODS Male Golden Syrian hamsters were divided in three groups: (i) fed with standard chow (N), (ii) fed with standard chow plus 3% cholesterol and 15% butter for 21 weeks (HL), (iii) HL treated with GIN (800 µg/kg body weight/day) in the last 5 weeks of fat diet (HL-GIN). Cholesterol (C), triglycerides (TG), non-esterified fatty acids (NEFA), SCD1 estimated activity (C16:1n7/C16:0; C18:1n9/C18:0) and gene expression, acetyl-CoA carboxylase (ACC), thiobarbituric acid reactive substances (TBARS), paraoxonase1 (PON1) and myeloperoxidase (MPO) were determined in the plasma and liver of all hamsters. We measured protein expression of endoplasmic reticulum stress (ERS) markers, gene and protein expression of liver X receptor α/β (LXRα/β), peroxisome proliferator-activated receptor γ (PPARγ), ATP-binding cassette sub-family G member 5/8 (ABCG5/G8) and 7α-hydroxylase1 (CYP7A1) in all hamsters' livers. RESULTS In plasma, in HL-GIN versus HL hamsters, SCD1 estimated activity was lower (27%; 15%, p < 0.05), NEFA levels decreased by 91%, p < 0.001, while C and TG levels did not vary; the oxidative stress expressed as MPO and TBARS levels decreased (15%; 11%, p < 0.01), while PON1 protein increased (75%, p < 0.05). In the liver of HL-GIN versus HL, C, TG, NEFA, MPO and TBARS levels decreased (8-40%, p < 0.05) and PON1 protein levels increased (30%, p < 0.05), SCD1 estimated activity decreased (8%; 9%, p < 0.05), in parallel with the reduced gene expression of SCD1 and ACC (70-80%, p < 0.05). The protein expression of the ERS sensors decreased (30-65%, p < 0.05), while that of ABCG5/G8, CYP7A1, LXRα/β and PPARγ increased in HL-GIN (20-30%, p < 0.05) versus HL liver. CONCLUSION GIN reduces SCD1 estimated activity and expression, as well as the lipids accumulated in the livers of HL hamsters. This is achieved through a mechanism involving the decrease of the oxidative and ERS, and the enhancement of cholesterol efflux.
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Affiliation(s)
- Mihaela Georgiana Carnuta
- Lipidomics Department, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 8, B.P. Hasdeu Street 050568, Bucharest, Romania
| | - Mariana Deleanu
- Lipidomics Department, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 8, B.P. Hasdeu Street 050568, Bucharest, Romania; University of Agronomical Sciences and Veterinary Medicine, Faculty of Biotechnology, 59, Marasti Blvd 011464, Bucharest, Romania
| | - Teodora Barbalata
- Lipidomics Department, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 8, B.P. Hasdeu Street 050568, Bucharest, Romania
| | - Laura Toma
- Lipidomics Department, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 8, B.P. Hasdeu Street 050568, Bucharest, Romania
| | - Mina Raileanu
- Lipidomics Department, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 8, B.P. Hasdeu Street 050568, Bucharest, Romania
| | - Anca Volumnia Sima
- Lipidomics Department, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 8, B.P. Hasdeu Street 050568, Bucharest, Romania
| | - Camelia Sorina Stancu
- Lipidomics Department, Institute of Cellular Biology and Pathology "Nicolae Simionescu" of the Romanian Academy, 8, B.P. Hasdeu Street 050568, Bucharest, Romania.
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25
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ALJohani AM, Syed DN, Ntambi JM. Insights into Stearoyl-CoA Desaturase-1 Regulation of Systemic Metabolism. Trends Endocrinol Metab 2017; 28:831-842. [PMID: 29089222 PMCID: PMC5701860 DOI: 10.1016/j.tem.2017.10.003] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/09/2017] [Accepted: 10/10/2017] [Indexed: 12/15/2022]
Abstract
Stearoyl-coenzyme A desaturase 1 (SCD1) is a central regulator of fuel metabolism and may represent a therapeutic target to control obesity and the progression of related metabolic diseases including type 2 diabetes and hepatic steatosis. SCD1 catalyzes the synthesis of monounsaturated fatty acids (MUFAs), mainly oleate and palmitoleate, which are important in controlling weight gain in response to feeding high carbohydrate diets. In this review, we evaluate the role of SCD1 isoform in the regulation of lipid and glucose metabolism in metabolic tissues. These highlights of recent findings are aimed toward advancing our understanding of the role of SCD1 in the development of metabolic diseases, which may help evaluate the possible health outcomes of modulating MUFA levels through targeting SCD1 activity.
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Affiliation(s)
- Ahmed M ALJohani
- School of Medicine and Public Health, Endocrinology and Reproductive Physiology Graduate Training Program, University of Wisconsin-Madison, Madison, WI 53706, USA; King Saud bin Abdulaziz University for Health Sciences, National Guard Health Affairs, Riyadh, 11426, Saudi Arabia
| | - Deeba N Syed
- School of Medicine and Public Health, Department of Dermatology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - James M Ntambi
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA; Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA.
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26
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Lounis MA, Bergeron KF, Burhans MS, Ntambi JM, Mounier C. Oleate activates SREBP-1 signaling activity in SCD1-deficient hepatocytes. Am J Physiol Endocrinol Metab 2017; 313:E710-E720. [PMID: 28851735 PMCID: PMC5814596 DOI: 10.1152/ajpendo.00151.2017] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 08/01/2017] [Accepted: 08/15/2017] [Indexed: 01/06/2023]
Abstract
Stearoyl-CoA desaturase-1 (SCD1) is a key player in lipid metabolism. SCD1 catalyzes the synthesis of monounsaturated fatty acids (MUFA). MUFA are then incorporated into triacylglycerols and phospholipids. Previous studies have shown that Scd1 deficiency in mice induces metabolic changes in the liver characterized by a decrease in de novo lipogenesis and an increase in β-oxidation. Interestingly, Scd1-deficient mice show a decrease in the expression and maturation of the principal lipogenic transcription factor sterol receptor element binding protein-1 (SREBP-1). The mechanisms mediating this effect on de novo lipogenesis and β-oxidation have not been fully elucidated. We evaluated the role of SCD1 on de novo lipogenesis and β-oxidation in HepG2 cells. We also used Scd1-deficient mice and two strains of transgenic mice that produce either oleate (GLS5) or palmitoleate (GLS3) in a liver-specific manner. We demonstrate that the expression of β-oxidation markers increases in SCD1-deficient hepatocytes and suggest that this is due to an increase in cellular polyunsaturated fatty acid content. We also show that the changes in the level of SREBP-1 expression, for both the precursor and the mature forms, are mainly due to the lack of oleate in SCD1-deficient hepatocytes. Indeed, oleate treatment of cultured HepG2 cells or hepatic oleate production in chow-fed GLS5 mice can restore SREBP-1 expression and increase hepatic de novo lipogenesis. Finally, we show that oleate specifically increases SREBP-1 nuclear accumulation, suggesting a central role for oleate in SREBP-1 signaling activity.
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Affiliation(s)
- Mohamed A Lounis
- BioMed Research Center, Biological Sciences Department, University of Quebec in Montreal, Montreal, Quebec, Canada
| | - Karl-F Bergeron
- BioMed Research Center, Biological Sciences Department, University of Quebec in Montreal, Montreal, Quebec, Canada
| | - Maggie S Burhans
- Nutritional Sciences Department, University of Wisconsin-Madison, Madison, Wisconsin; and
| | - James M Ntambi
- Nutritional Sciences Department, University of Wisconsin-Madison, Madison, Wisconsin; and
- Biochemistry Department, University of Wisconsin-Madison, Madison, Wisconsin
| | - Catherine Mounier
- BioMed Research Center, Biological Sciences Department, University of Quebec in Montreal, Montreal, Quebec, Canada;
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27
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Paton CM, Vaughan RA, Selen Alpergin ES, Assadi-Porter F, Dowd MK. Dihydrosterculic acid from cottonseed oil suppresses desaturase activity and improves liver metabolomic profiles of high-fat-fed mice. Nutr Res 2017; 45:52-62. [PMID: 29037332 DOI: 10.1016/j.nutres.2017.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 05/30/2017] [Accepted: 06/27/2017] [Indexed: 01/15/2023]
Abstract
Polyunsaturated fatty acid (PUFA)-rich diets are thought to provide beneficial effects toward metabolic health in part through their bioactive properties. We hypothesized that increasing PUFA intake in mice would increase peroxisome proliferator activated receptor delta (PPARδ) expression and activity, and we sought to examine the effect of different PUFA-enriched oils on muscle PPARδ expression. One of the oils we tested was cottonseed oil (CSO) which is primarily linoleic acid (53%) and palmitic acid (24%). Mice fed a CSO-enriched diet (50% energy from fat) displayed no change in muscle PPARδ expression; however, in the liver, it was consistently elevated along with its transcriptional coactivator Pgc-1. Male mice were fed chow or CSO-, saturated fat (SFA)-, or linoleic acid (18:2)-enriched diets that were matched for macronutrient content for 4 weeks. There were no differences in food intake, body weight, fasting glucose, glucose tolerance, or energy expenditure between chow- and CSO-fed mice, whereas SFA-fed mice had increased fat mass and 18:2-fed mice were less glucose tolerant. Metabolomic analyses revealed that the livers of CSO-fed mice closely matched those of chow-fed but significantly differed from SFA- and 18:2-enriched groups. Fatty acid composition of the diets and livers revealed an impairment in desaturase activity and the presence of dihydrosterculic acid (DHSA) in the CSO-fed mice. The effect of DHSA on PPARδ and stearoyl-CoA desaturase-1 expression mimicked that of the CSO-fed mice. Taken together, these data suggest that DHSA from CSO may be an effective means to increase PPARδ expression with concomitant suppression of liver stearoyl-CoA desaturase-1 activity.
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Affiliation(s)
- Chad M Paton
- Department of Food Science & Technology, University of Georgia, Athens, GA; Foods & Nutrition, University of Georgia, Athens, GA; Texas Tech University.
| | | | | | | | - Michael K Dowd
- Southern Regional Research Center, ARS, USDA, New Orleans, LA
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28
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Ducheix S, Montagner A, Polizzi A, Lasserre F, Régnier M, Marmugi A, Benhamed F, Bertrand-Michel J, Mselli-Lakhal L, Loiseau N, Martin PG, Lobaccaro JM, Ferrier L, Postic C, Guillou H. Dietary oleic acid regulates hepatic lipogenesis through a liver X receptor-dependent signaling. PLoS One 2017; 12:e0181393. [PMID: 28732092 PMCID: PMC5521785 DOI: 10.1371/journal.pone.0181393] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 06/22/2017] [Indexed: 12/13/2022] Open
Abstract
Olive oil consumption is beneficial for health as it is associated with a decreased prevalence of cancer and cardiovascular diseases. Oleic acid is, by far, the most abundant component of olive oil. Since it can be made through de novo synthesis in animals, it is not an essential fatty acid. While it has become clear that dietary oleic acid regulates many biological processes, the signaling pathway involved in these regulations remains poorly defined. In this work we tested the impact of an oleic acid-rich diet on hepatic gene expression. We were particularly interested in addressing the contribution of Liver X Receptors (LXR) in the control of genes involved in hepatic lipogenesis, an essential process in whole body energy homeostasis. We used wild-type mice and transgenic mice deficient for both α and β Liver X Receptor isoforms (LXR-/-) fed a control or an oleate enriched diet. We observed that hepatic-lipid accumulation was enhanced as well as the expression of lipogenic genes in the liver of wild-type mice fed the oleate enriched diet. In contrast, none of these changes occurred in the liver of LXR-/- mice. Strikingly, oleate-rich diet reduced cholesterolemia in wild-type mice and induced signs of liver inflammation and damage in LXR-/- mice but not in wild-type mice. This work suggests that dietary oleic acid reduces cholesterolemia while promoting LXR-dependent hepatic lipogenesis without detrimental effects to the liver.
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Affiliation(s)
- Simon Ducheix
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Alexandra Montagner
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Arnaud Polizzi
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Frédéric Lasserre
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Marion Régnier
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Alice Marmugi
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Fadila Benhamed
- INSERM, U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France
| | | | - Laila Mselli-Lakhal
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Nicolas Loiseau
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Pascal G Martin
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Jean-Marc Lobaccaro
- Clermont Université, Université Blaise Pascal, Génétique Reproduction et Développement, Clermont-Ferrand, France.,CNRS, UMR 6293, GReD, Aubière, France.,INSERM, U1103, GReD, Aubière, France.,Centre de Recherche en Nutrition Humaine d'Auvergne, Clermont-Ferrand, France
| | - Laurent Ferrier
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
| | - Catherine Postic
- INSERM, U1016, Institut Cochin, Paris, France.,CNRS, UMR8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Hervé Guillou
- INRA, ToxAlim, Toulouse, France.,Université de Toulouse, INP, UPS, ToxAlim, Toulouse, France
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29
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NAFLD as a Sexual Dimorphic Disease: Role of Gender and Reproductive Status in the Development and Progression of Nonalcoholic Fatty Liver Disease and Inherent Cardiovascular Risk. Adv Ther 2017; 34:1291-1326. [PMID: 28526997 PMCID: PMC5487879 DOI: 10.1007/s12325-017-0556-1] [Citation(s) in RCA: 356] [Impact Index Per Article: 50.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Indexed: 02/06/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) spans steatosis through nonalcoholic steatohepatis, cirrhosis, and hepatocellular carcinoma (HCC) associated with striking systemic features and excess cardiovascular and liver-related mortality. The pathogenesis of NAFLD is complex and multifactorial. Endocrine derangements are closely linked with dysmetabolic traits. For example, in animal and human studies, female sex is protected from dysmetabolism thanks to young individuals’ ability to partition fatty acids towards ketone body production rather than very low density lipoprotein (VLDL)-triacylglycerol, and to sex-specific browning of white adipose tissue. Ovarian senescence facilitates both the development of massive hepatic steatosis and the fibrotic progression of liver disease in an experimental overfed zebrafish model. Consistently, estrogen deficiency, by potentiating hepatic inflammatory changes, hastens the progression of disease in a dietary model of nonalcoholic steatohepatitis (NASH) developing in ovariectomized mice fed a high-fat diet. In humans, NAFLD more often affects men; and premenopausal women are equally protected from developing NAFLD as they are from cardiovascular disease. It would be expected that early menarche, definitely associated with estrogen activation, would produce protection against the risk of NAFLD. Nevertheless, it has been suggested that early menarche may confer an increased risk of NAFLD in adulthood, excess adiposity being the primary culprit of this association. Fertile age may be associated with more severe hepatocyte injury and inflammation, but also with a decreased risk of liver fibrosis compared to men and postmenopausal status. Later in life, ovarian senescence is strongly associated with severe steatosis and fibrosing NASH, which may occur in postmenopausal women. Estrogen deficiency is deemed to be responsible for these findings via the development of postmenopausal metabolic syndrome. Estrogen supplementation may at least theoretically protect from NAFLD development and progression, as suggested by some studies exploring the effect of hormonal replacement therapy on postmenopausal women, but the variable impact of different sex hormones in NAFLD (i.e., the pro-inflammatory effect of progesterone) should be carefully considered.
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30
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Oliveira LG, Moreno LG, Melo DS, Costa-Pereira LV, Carvalho MMDF, Silva PHE, Alves AM, Magalhães FDC, Dias-Peixoto MF, Esteves EA. Caryocar brasiliense oil improves cardiac function by increasing Serca2a/PLB ratio despite no significant changes in cardiovascular risk factors in rats. Lipids Health Dis 2017; 16:37. [PMID: 28179001 PMCID: PMC5299795 DOI: 10.1186/s12944-017-0422-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 01/21/2017] [Indexed: 12/15/2022] Open
Abstract
Background Caryocar brasiliense (pequi) oil is high in monounsaturated fat acids (MUFA), especially oleic, and in carotenoids, which have been associated with protection against cardiovascular disease. However, this food is poorly studied in this context, especially in the cardiac function. Therefore, we investigated the effects of a long-term intake of pequi oil in systemic cardiovascular risk factors and in the ex vivo cardiac function of rats. Methods Previously, we determined fatty acids and carotenoids in pequi oil. Next, male rats were divided in C – control group feed a standard diet, and PO – pequi oil group fed the same diet added pequi oil (+2.25 g.100 g−1). After 15 weeks, plasma lipids, glucose, insulin, blood pressure, heart rate, hepatic lipids were accessed and visceral fat pads were harvested. Hearts were used for the ex vivo cardiac function, histologic assays, SERCA2a and phospholanban (PLB) determinations. Results In agreement with scientific data, pequi oil had expressive amounts MUFA, especially oleic acid, and carotenoids. Hepatic triglycerides (TG) were reduced by pequi oil intake (p < 0.05). All others cardiovascular risk factors were not changed. The intrinsic heart rate was lower in PO group (p < 0.05). SERCA2a content was higher in this group (p < 0.05), without affecting PLB. Also, SERCA2a/PLB ratio increased in PO group (p < 0.05). Conclusion Pequi oil intake improved cardiac function ex vivo, despite no significant changes in systemic cardiovascular risk factors. The higher lipid offer in pequi oil diet, its composition in oleic acid and carotenoids could be related to those effects.
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Affiliation(s)
- Lidiane Guedes Oliveira
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis) - Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Rodovia MGT 367 - Km 583, n° 5000, Alto da Jacuba, Diamantina, MG, Brazil, CEP: 39100-000
| | - Lauane Gomes Moreno
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis) - Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Rodovia MGT 367 - Km 583, n° 5000, Alto da Jacuba, Diamantina, MG, Brazil, CEP: 39100-000
| | - Dirceu Sousa Melo
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis) - Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Rodovia MGT 367 - Km 583, n° 5000, Alto da Jacuba, Diamantina, MG, Brazil, CEP: 39100-000
| | - Liliane Vanessa Costa-Pereira
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis) - Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Rodovia MGT 367 - Km 583, n° 5000, Alto da Jacuba, Diamantina, MG, Brazil, CEP: 39100-000
| | - Mayara Medeiros de Freitas Carvalho
- Programa de Pós-Graduação em Ciências Biológicas, Universidade Federal de Ouro Preto - Campus Universitário, Morro do Cruzeiro, Ouro Preto, MG, Brazil, CEP: 35400-000
| | - Paulo Henrique Evangelista Silva
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis) - Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Rodovia MGT 367 - Km 583, n° 5000, Alto da Jacuba, Diamantina, MG, Brazil, CEP: 39100-000
| | - Ana Maria Alves
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis) - Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Rodovia MGT 367 - Km 583, n° 5000, Alto da Jacuba, Diamantina, MG, Brazil, CEP: 39100-000
| | - Flávio de Castro Magalhães
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis) - Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Rodovia MGT 367 - Km 583, n° 5000, Alto da Jacuba, Diamantina, MG, Brazil, CEP: 39100-000
| | - Marco Fabrício Dias-Peixoto
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis) - Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Rodovia MGT 367 - Km 583, n° 5000, Alto da Jacuba, Diamantina, MG, Brazil, CEP: 39100-000
| | - Elizabethe Adriana Esteves
- Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia (SBFis) - Universidade Federal dos Vales do Jequitinhonha e Mucuri - UFVJM, Rodovia MGT 367 - Km 583, n° 5000, Alto da Jacuba, Diamantina, MG, Brazil, CEP: 39100-000.
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31
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Abstract
Nonalcoholic steatohepatitis (NASH) has become a major cause of cirrhosis and liver-related deaths worldwide. NASH is strongly associated with obesity and the metabolic syndrome, conditions that cause lipid accumulation in hepatocytes (hepatic steatosis). It is not well understood why some, but not other, individuals with hepatic steatosis develop NASH. The factors that determine whether or not NASH progresses to cirrhosis are also unclear. This review summarizes key components of NASH pathogenesis and discusses how inherent and acquired variations in regulation of these processes impact the risk for NASH and NASH cirrhosis.
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Affiliation(s)
- Ayako Suzuki
- Department of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Anna Mae Diehl
- Division of Gastroenterology, School of Medicine, Duke University, Durham, North Carolina 27710;
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