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第44卷第5期
               ·616 ·                            南 京    医 科 大 学 学         报                        2024年5月


              for measuring the levels of liver function markers(alanine aminotransferase,ALT;aspartate aminotransferase,AST)and lipoproteins
             (high⁃density lipoprotein cholesterol,HDL⁃C;low⁃density lipoprotein cholesterol,LDL⁃C). ③Primary hepatocytes overexpressed
              Hspa12a were treated with LPS(500 ng/mL)to emulate endotoxemia induced liver injury. Six hours after LPS treatment,culture
              medium was collected for measuring levels of ALT and AST. ④Patients were divided into the sepsis induced liver injury group and the
              control group according to whether the septic liver injury occurred. ALT,AST,HDL⁃C and LDL⁃C levels were collected and compared
              between the two groups. Results:①Bioinformatic analysis showed that the levels of Hspa12a,Apoa1,Apob and Apom mRNA were
              decreased in livers of septic mice. ②Compared with NS⁃WT mice,LPS⁃WT mice displayed obvious histopathological injury in liver
              tissues(P < 0.001)and the number of inflammatory foci was increased(P < 0.01)along with the elevated serum ALT(P < 0.05)and
              AST(P < 0.01)activiaties. At the same time,the expression of HSPA12A protein in liver was decreased(P < 0.05). However,
              compared with LPS⁃WT mice,LPS⁃Hspa12a -/-  mice showed more severe pathological damage of liver tissues(P < 0.05),along with
              higher ALT(P < 0.01)and AST(P < 0.05)levels and lower HDL⁃C and LDL⁃C levels(P < 0.01). At the same time,the expression
              levels of hepatic apolipoproteins(ApoA1,ApoB,ApoM)were reduced(P < 0.05,P < 0.01). ③In vitro,ALT and AST levels in culture
              medium of hepatocytes were signaficantly increased after LPS treatment(P < 0.001). However,overexpression of Hspa12a alleviated
              the increases of ALT and AST levels(P < 0.01). ④Clinical results suggested that compared with the control group,the sepsis induced
              liver injury group showed signaficantly higher serum ALT and AST levels(P < 0.001). In contrast,HDL⁃C and LDL⁃C levels were
              signaficantly lower(P < 0.001). Conclusion:Endotoxemia leads to downregulation of hepatic HSPA12A expression,which mediates
              the development of endotoxemic liver injury. However,overexpression of Hspa12a can protect liver injury induced by endotoxemia. The
              action of HSPA12A may involve the regulation of hepatic apolipoprotein expression and serum lipoprotein cholesterol levels.
             [Key words] heat shock protein A12A;endotoxemia;hepatic injury;apolipoprotein
                                                                            [J Nanjing Med Univ,2024,44(05):615⁃625]





                  脓毒症是指由宿主对感染反应失调引起的危                           是否与脂质代谢有关,以期进一步揭示内毒素血症
              及生命的器官功能障碍,是世界范围内死亡的主要                            肝损伤的发病机制,为发现新的治疗靶点提供数据
              原因  [1-2] 。肝脏是脓毒症最常累及的器官,约46%的                    支持。
                                                   [3]
              脓毒症患者伴有肝功能不全,病死率更高 。因此,
                                                                1 材料和方法
              探究脓毒症所致肝损伤的分子机制,寻找其潜在靶
              点具有重要的临床意义。                                       1.1  材料
                  脓毒症过程中会出现脂蛋白和脂质代谢异常,                          1.1.1  动物
              反过来脂蛋白和脂质代谢异常也可通过炎症以及                                  Hspa12a基因敲除(Hspa12a knockout,Hspa12a )
                                                                                                            -/-
              氧化应激等途径加重脓毒症造成的脏器损伤                     [4- 5] ,研  鼠由本课题组前期构建完成 。本研究采用6~8周
                                                                                          [9]
              究表明脓毒症期间胆固醇下降常导致多器官功能                             雄性小鼠(SPF级)用于实验,对照组采用同窝所生、
              障碍以及不良预后         [6-8] 。探讨脂质代谢与脓毒症之               同性别、野生型(wild type,WT)鼠。实验动物饲养
              间的关系,有助于更好地了解脓毒症的发病机制,                            于SPF级动物实验房中,温度控制在(22±2)℃,12 h
              制定有效的治疗策略。                                        光照/黑暗循环,自由饮食,饲料由南京大学模式动
                  热 休 克 蛋 白 A12A(heat shock protein A12A,       物研究所提供。本实验已获得南京医科大学实验
              HSPA12A)是 HSP70 家族的不典型成员。本课题                      动 物 福 利 伦 理 委 员 会 批 准(编 号 :SYXK ⁃ 2015 ⁃
              组前期研究显示,HSPA12A 具有多种生物学功能,                        0015)。
              例如保护缺血性脑损伤和缺血/再灌注肝损伤                     [9-10] 。  1.1.2  试剂
              值得关注的是,HSPA12A 可减轻内毒素所致肺损                              脂多糖(lipopolysaccharide,LPS)(Sigma⁃Aldrich
              伤 [11] ,而 Hspa12a 基因敲除对高脂饮食所致血浆脂                  公司,美国),DMEM 培养基、胎牛血清、Ⅳ型胶原酶
              蛋白增高具有抑制作用           [12] 。然而,在内毒素血症期            (Gibco 公司,美国),Hank’s 缓冲盐溶液(安徽白鲨
              间,HSPA12A 能否通过调控脂蛋白、进而影响肝损                        生物科技有限公司),GAPDH 抗体(Bioworld 公司,
              伤尚不明确。本研究旨在明确 HSPA12A 在内毒素                        美国),HSPA12A 抗体(Abcam 公司,美国),ApoA1
              所致肝损伤中的病理生理作用,并初步探讨该作用                            抗体、ApoB 抗体、ApoM 抗体(武汉三鹰生物技术有
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