title: [Effects of metformin on the polarization and Notch 1 expression of RAW264.7 macrophages].
abstract: OBJECTIVE
  To explore the possible effects of metformin on regulating the Notch1 expression and the polarization of RAW264.7 macrophages.
  
  
  METHODS
  RAW264.7 macrophages were divided into two groups according to different metformin concentrations (0, 1, 5, 10 mmol/L) and treatment length (0, 12, 24, 48 h). The expressions of interleukin-1β (IL-1β) and interleukin-10 (IL-10) mRNA were detected by real time quantity-polymerase chain reaction (RTQ-PCR). RAW264.7 macrophages were divided into control, metformin-treated, lipopolysaccharide (LPS)-treated and LPS-metformin-treated groups. Then the expressions of IL-1β, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), arginase 1 (Arg1), IL-10, interleukin-4 (IL-4), macrophage galactose-type lectin-1 (Mgl1) and Notch1 mRNA were detected with RTQ-PCR. The expression of Notch1 protein was examined by Western blot.
  
  
  RESULTS
  At the concentrations of 0-10 mmol/L for 0-48 h, metformin in concentration and time-dependent ways promoted the expression of IL-10 mRNA and inhibited the mRNA expression of IL-1β in RAW264.7 macrophages (both P < 0.05). In metformin-treated cells, the expressions of Arg1 (P = 0.009), IL-10 (P = 0.015) and IL-4 (P = 0.001) mRNA increased while the expressions of IL-1β (P = 0.001) and IL-6 (P = 0.032) mRNA decreased. And it was the same as the levels of Notch1 mRNA (P = 0.004) and protein. The LPS-treated group could up-regulate the expressions of IL-1β (P < 0.001), IL-6 (P = 0.002), TNF-α (P = 0.005) mRNA and Notch1 (P = 0.002) mRNA (protein). And there was a declining trend for the expressions of Arg1, IL-10, IL-4 and Mgl1 mRNA in macrophages (both P>0.05). On the contrary, in LPS-metformin-treated cells, the gene expressions of IL-1β (P < 0.001), IL-6 (P = 0.005), TNF-α (P = 0.029) and Notch1 (P = 0.006) mRNA (along with protein) were down-regulated while Arg1 (P = 0.005), IL-10 (P < 0.001), IL-4 (P < 0.001) and Mgl1 (P = 0.001) mRNA expressions up-regulated.
  
  
  CONCLUSIONS
  Metformin regulates RAW264.7 macrophages with/without LPS toward a M2 phenotype. And Notch1 signaling may play a critical role.
authors.affiliation: Institute of Metabolism & Endocrinology, Second Xiangya Hospital, Central South University, Diabetes Center of Central South University, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha 410011, China.
authors.forename: Miaojiao
authors.initials: M
authors.lastname: Chen
authors.affiliation: Institute of Metabolism & Endocrinology, Second Xiangya Hospital, Central South University, Diabetes Center of Central South University, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha 410011, China.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Metabolism & Endocrinology, Second Xiangya Hospital, Central South University, Diabetes Center of Central South University, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha 410011, China; Email: shipingliu119@126.com.
authors.forename: Shiping
authors.initials: S
authors.lastname: Liu
authors.affiliation: Institute of Metabolism & Endocrinology, Second Xiangya Hospital, Central South University, Diabetes Center of Central South University, Key Laboratory of Diabetes Immunology, Ministry of Education, National Clinical Research Center for Metabolic Diseases, Changsha 410011, China.
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D000818:Animals; D016764:Cell Polarity; D015870:Gene Expression; D053583:Interleukin-1beta; D008264:Macrophages; D008687:Metformin; D051379:Mice; D000067996:RAW 264.7 Cells; D012333:RNA, Messenger; D051881:Receptor, Notch1; D015398:Signal Transduction; D015854:Up-Regulation
chemical_list: D053583:Interleukin-1beta; C497762:Notch1 protein, mouse; D012333:RNA, Messenger; D051881:Receptor, Notch1; D008687:Metformin