广西医学

及其作用机制。方法将小鼠AML12细胞分为对照组、1 nM 1，25（OH）2D3组、5 nM 1，25（OH）2D3组、10 nM 1，25（OH）2D3组、50 nM 1，25（OH）2D3组、100 nM 1，25（OH）2D3组、200 nM 1，25（OH）2D3组、300 nM 1，25（OH）2D3组，对照组仅加入DMEM⁃F12完全培养基，其余组分别加入相应浓度的1，25（OH）2D3的DMEM⁃F12完全培养基干预24 h。另外取部分小鼠AML12细胞，给予200 μM PA干预24 h，构建非酒精性脂肪性肝病（NAFLD）细胞模型，将构建成功的NAFLD细胞分为PA模型组、PA+1 nM 1，25（OH）2D3组、PA+5 nM 1，25（OH）2D3组、PA+10 nM 1，25（OH）2D3组、PA+50 nM 1，25（OH）2D3组、PA+100 nM 1，25（OH）2D3组、PA+200 nM 1，25（OH）2D3组及PA+300 nM 1，25（OH）2D3组，PA模型组仅加入DMEM⁃F12完全培养基，其余组分别加入相应浓度的1，25（OH）2D3的DMEM⁃F12完全培养基干预24 h，然后检测各组小鼠AML12细胞的增殖活力，筛选出1，25（OH）2D3的最佳干预浓度（100 nM）。选取对照组、PA模型组、PA+100 nM 1，25（OH）2D3组、100 nM 1，25（OH）2D3组，检测各组小鼠AML12细胞增殖活力、细胞内活性氧和丙二醛及甘油三酯（TG）含量，以及沉默信息调节因子2相关酶1（Sirt1）、腺苷单磷酸活化蛋白激酶（AMPKα）和磷酸化AMPKα（p⁃AMPKα）的表达水平。结果 PA+1 nM 1，25（OH）2D3组、PA+5 nM 1，25（OH）2D3组、PA+10 nM 1，25（OH）2D3组、PA+50 nM 1，25（OH）2D3组、PA+100 nM 1，25（OH）2D3组、PA+200 nM 1，25（OH）2D3组及PA+300 nM 1，25（OH）2D3组的小鼠AML12细胞增殖活力较PA模型组升高，且PA+100 nM 1，25（OH）2D3组的小鼠AML12细胞增殖活力较PA+其余浓度1，25（OH）2D3组升高（P<0.05）。与对照组相比，PA模型组的小鼠AML12细胞增殖活力降低，TG、活性氧和丙二醛含量增加，Sirt1、p⁃AMPKα和AMPKα表达水平减少（P<0.05）。与PA模型组相比，PA+100 nM 1，25（OH）2D3组及100 nM 1，25（OH）2D3组小鼠AML12细胞中TG、活性氧和丙二醛含量减少，Sirt1、p⁃AMPKα和AMPKα表达水平增加（P<0.05）。结论 1，25（OH）2D3可增加PA诱导的小鼠AML12细胞的增殖活力，减轻其脂肪堆积、氧化应激和脂质过氧化，其机制可能是通过激活Sirt1/AMPK信号通路，增加Sirt1和AMPK磷酸化，从而改善NAFLD的肝损伤。

Objective To explore the effect of 1, 25⁃dihydroxyvitamin D3, namely 1,25(OH)2D3, on palmitic acid (PA)⁃induced lipid accumulation and oxidative stress in AML12 cells of mice and its mechanism. Methods Mouse AML12 cells were assigned to control group, or 1 nM, 5 nM, 10 nM, 50 nM, 100 nM, 200 nM, and 300 nM 1,25(OH)₂D₃ groups. The control group was added with DMEM⁃F12 complete medium only, while the remaining groups were added with DMEM⁃F12 complete medium containing corresponding concentrations of 1,25(OH)₂D₃ for 24⁃hour intervention. In addition, some mouse AML12 cells were obtained and treated with 200 μM PA for 24⁃hour intervention to construct a non⁃alcoholic fatty liver disease (NAFLD) cell model. The successfully constructed NAFLD cells were divided into PA model group, or PA+1 nM, PA+5 nM, PA+10 nM, PA+50 nM, PA+100 nM, PA+200 nM, and PA+300 nM 1,25(OH)₂D₃ groups. The PA model group was treated with DMEM⁃F12 complete medium only, while the remaining groups were treated with DMEM⁃F12 complete medium containing corresponding concentrations of 1,25(OH)₂D₃ for 24⁃hour intervention. The proliferative activity of mouse AML12 cells in each group was then measured to determine the optimal intervention concentration of 1,25(OH)₂D₃ (100 nM). The control group, PA model group, PA+100 nM 1,25(OH)₂D₃ group, and 100 nM 1,25(OH)₂D₃ group were selected to measure mouse AML12 cell proliferative activity, intracellular contents of reactive oxygen species, malondialdehyde, and triglyceride (TG), as well as the expressions of silencing information regulator 2 related enzyme 1 (Sirt1), adenosine 5'⁃monophosphate activated protein kinase (AMPKα), and phosphorylated AMPKα (p⁃AMPKα). Results The proliferative activity of mouse AML12 cells in the PA+1 nM, PA+5 nM, PA+10 nM, PA+50 nM, PA+100 nM, PA+200 nM, and PA+300 nM 1,25(OH)₂D₃ groups was higher than that in the PA model group. Moreover, the proliferative activity of mouse AML12 cells in the PA+100 nM 1,25(OH)₂D₃ group was higher than that in the PA+the remaining concentrations of 1,25(OH)₂D₃ groups (P<0.05). Compared with the control group, the PA model group exhibited decreased proliferative activity of mouse AML12 cell proliferation, increased contents of TG, reactive oxygen species, and malondialdehyde, and decreased expressions of Sirt1, p⁃AMPKα, and AMPKα (P<0.05). Compared with the PA model group, the PA+100 nM 1,25(OH)₂D₃ group and the 100 nM 1,25(OH)₂D₃ group showed decreased contents of TG, reactive oxygen species, and malondialdehyde, and increased expressions of Sirt1, p⁃AMPKα, and AMPKα in mouse AML12 cells (P<0.05). Conclusion 1,25 (OH) 2D3 can increase the proliferation activity of PA⁃induced mouse AML12 cells, reduce their lipid accumulation, oxidative stress and lipid peroxidation, and its mechanism may be to activate Sirt1/AMPK signaling pathway and increase the phosphorylation of Sirt1 and AMPK, thereby improving the liver injury of NAFLD.