β-Carotene accumulation in 3T3-L1 adipocytes inhibits the elevation of reactive oxygen species and the suppression of genes related to insulin sensitivity induced by tumor necrosis factor-α

• Published in: Nutrition (Burbank, Los Angeles County, Calif.) Vol. 26; no. 11; pp. 1151 - 1156
• Main Authors: Kameji, Hiroyuki, M.S, Mochizuki, Kazuki, Ph.D, Miyoshi, Noriyuki, Ph.D, Goda, Toshinao, Ph.D
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.11.2010; [New York]: Elsevier Science Inc; Elsevier; Elsevier Limited
• Subjects: 3T3-L1 adipocytes; 3T3-L1 Cells; Accumulation; Adipocyte; adipocytes; Adipocytes - metabolism; Adipogenesis; Adiponectin - genetics; Adiponectin - metabolism; Adiponectin - secretion; Adipose tissue; Animals; antioxidant activity; beta Carotene - metabolism; beta-carotene; bioaccumulation; Biological and medical sciences; cell culture; cell lines; Diabetes; Fatty Acid-Binding Proteins - genetics; Fatty Acid-Binding Proteins - metabolism; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; Gastroenterology and Hepatology; Gene Expression Regulation; genes; Genes related to insulin sensitivity; Glucose Transporter Type 4 - genetics; Glucose Transporter Type 4 - metabolism; Hyperglycemia; Insulin; Insulin Resistance; Metabolic disorders; Mice; Osmolar Concentration; Oxidative Stress; Oxygen; PPAR gamma - genetics; PPAR gamma - metabolism; Proteins; Reactive oxygen species; Reactive Oxygen Species - metabolism; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Signal Transduction; tumor necrosis factor-alpha; Tumor Necrosis Factor-alpha - metabolism; Up-Regulation; Vertebrates: anatomy and physiology, studies on body, several organs or systems; β-Carotene; Adipocyte; Genes related to insulin sensitivity; Insulin resistance; Reactive oxygen species; β-Carotene; Endocrinopathy; Pancreatic hormone; Carotene; Cytokine; Metabolic diseases; Insulin; Target tissue resistance; Vertebrata; Sensitivity; Mammalia; Gene; Biological accumulation; Tumor necrosis factor α
• ISSN: 0899-9007; 1873-1244
• DOI: 10.1016/j.nut.2009.09.006

Abstract Objective β-Carotene is an abundant carotenoid with potent antioxidative activities and accumulates in adipose tissue. However, its physiologic functions are poorly understood. In this study, we examined whether accumulation of β-carotene for 4 d in insulin-resistant 3T3-L1 adipocytes alters the expression of genes related to insulin sensitivity. Methods The 3T3-L1 adipocytes were treated with/without 10 or 20 μM β-carotene during differentiation for 4 d. The cells treated with 10 μM β-carotene for 4 d were subsequently incubated with/without 5 ng/mL of tumor necrosis factor-α for 48 h in the medium without β-carotene. The mRNA levels of genes in the cells and adiponectin protein levels in the medium were determined by real-time reverse transcription–polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Reactive oxygen species levels in the cells were assessed by oxidation of 2′,7′-dichlorodihydrofluorescein diacetate. Result β-Carotene treatment at a concentration of 20 μM, but not 10 μM, in 3T3-L1 adipocytes during differentiation for 4 d enhanced the expression of genes related to insulin sensitivity, including adiponectin, adipocyte lipid-binding protein, glucose transporter-4, peroxisome proliferator-activated receptor-γ2, and adiponectin protein in the medium. Tumor necrosis factor-α treatment repressed the expression of these genes and adiponectin protein in the medium and induced reactive oxygen species levels. In contrast, cells that accumulated β-carotene at a concentration of 10 μM did not show these alterations. Conclusion The accumulation of the β-carotene in 3T3-L1 adipocytes restores the expression of genes related to insulin sensitivity and reactive oxygen species levels in insulin-resistant adipocytes.