AMPK activator AICAR ameliorates ischaemia reperfusion injury in the rat kidney

BACKGROUND AND PURPOSE Renal ischaemia/reperfusion (RI/R) injury is a major cause of acute kidney injury (AKI) and an important determinant of long-term kidney dysfunction. AMP-kinase and histone deacetylase sirtuin 1 (SIRT1) regulate cellular metabolism and are activated during hypoxia. We investigated whether AMP-kinase activator AICAR (5-amino-4-imidazolecarboxamide riboside-1-β-D-ribofuranoside) ameliorates RI/R injury and whether SIRT1 is involved in the pathogenesis. EXPERIMENTAL APPROACH Eight-week-old Sprague Dawley rats were divided into five groups: (i) sham-operated group; (ii) I/R group (40 min bilateral ischaemia followed by 24 h of reperfusion; (iii) I/R group + AICAR 50 mg·kg(-1) i.v. given 60 min before operation; (iv). I/R group + AICAR 160 mg·kg(-1) i.v; (v) I/R group + AICAR 500 mg·kg(-1) i.v. Serum creatinine and urea levels were measured. Acute tubular necrosis (ATN), monocyte/macrophage infiltration and nitrotyrosine expression were scored. Kidney AMP-activated protein kinase (AMPK) and SIRT1 expressions were measured. KEY RESULTS Highest dose of AICAR decreased serum creatinine and urea levels, attenuated I/R injury-induced nitrosative stress and monocyte/macrophage infiltration, and ameliorated the development of ATN. Kidney I/R injury was associated with decreased AMPK phosphorylation and a fivefold increase in kidney SIRT1 expression. AICAR increased pAMPK/AMPK ratio and prevented the I/R-induced increase in renal SIRT1 expression. CONCLUSIONS AND IMPLICATIONS AICAR protects against the development of ATN after kidney I/R injury. Activators of kidney AMP kinase may thus represent a novel therapeutic approach to patients susceptible to AKI and to those undergoing kidney transplantation. The present study also suggests a role for SIRT1 in the pathogenesis of RI/R injury.     

Decabromodiphenyl ether-induced PRKACA hypermethylation contributed to glycolipid metabolism disorder via regulating PKA/AMPK pathway in rat and L-02 cells

BDE-209 is the most prevalent congener of polybrominated diphenyl ethers and has high bioaccumulation in humans and animals. BDE-209 has been reported to disrupt glycolipid metabolism, but the mechanisms are still unclear. In this study, we found that BDE-209 induced liver tissue injury and hepatotoxicity, increased the glucose and total cholesterol levels in the serum of rats, and increased glucose and triglyceride levels in L-02 cells. BDE-209 exposure changed the PKA, p-PKA, AMPK, p-AMPK, ACC, and FAS expression in rats’ liver and L-02 cells. Moreover, BDE-209 induced PRKACA-1 hypermethylation in L-02 cells. AMPK activator (AICAR) inhibited the changes of p-AMPK, ACC, and FAS expression and elevation of glucose and triglyceride levels induced by BDE-209. DNA methylation inhibitor (5-Aza-CdR) reversed BDE-209 induced alters of PKA/AMPK/ACC/FAS signaling pathway. These results demonstrated that BDE-209 could disrupt the glycolipid metabolism by causing PRKACA-1 hypermethylation to regulate the PKA/AMPK signaling pathway in hepatocytes.     

PARP-1抑制剂下调SIRT1基因表达诱导非小细胞肺癌A549细胞凋亡的机制

目的 观察PARP-1抑制剂Olaparib对非小细胞肺癌A549细胞凋亡的影响及可能机制.方法 常规培养A549细胞,分别给予不同剂量Olaparib(0、5、10、20、50μmol/L)和(或)SIRT1激动剂SRT1720(1μmol/L)、SIRT1抑制剂EX527(1μmol/L)处理24 h,MTT法检测细胞增殖,流式细胞术检测细胞凋亡,Western-blot检测细胞SIRT1及凋亡相关基因表达.结果 Olaparib处理A549细胞24 h后,细胞存活率、SIRT1及抗凋亡基因Bcl-2蛋白表达逐渐降低,凋亡率及促凋亡基因Bax、Caspase-3蛋白表达逐渐增加,呈剂量依赖性(P<0.05).单独给予EX527处理A549细胞能够模拟Olaparib的上述作用(P<0.05),但SRT1720和Olaparib联合组能够拮抗Olaparib的上述作用(P<0.05).结论 PARP-1抑制剂Olaparib通过下调SIRT1基因表达抑制A549细胞增殖,并诱导其凋亡.     

Cucurbitacin E induces apoptosis and attenuates activation of hepatic stellate cells via PI_3K/Akt-AMPK-mTOR signaling pathway

OBJECTIVE Hepatic fibrosis is a wound-healing response for injury.Activated hepatic stellate cells(HSCs)are the preferred targets of anti-hepatic fibrotic therapies.cucurbitacin E(CuE)is,one well-known natural compound derived from traditional Chinese medicine,used in Asian countries for the prevention and treatment of hepatic disease.Therefore,the present study elucidated the mechanism of CuE on inducing apoptosis and attenuating hepatic fibrosis towards activated HSCs.METHODS The murine HSC(tHSC/Cl-6)cell line were incubated in 96-well plates and treated with TNF-αand CuE at various concentrations and indicated times.Cell viability was assessed with MTT assay.Another,t-HSC/Cl-6 were incubated in 6-well plates and also treated with TNF-α,CuE,AICAR or metformin for the indicated time and concentration.Cell protein and mRNA were prepared using kit and relevant signaling were detected by Western blotting and RT-PCR.RESULTS CuE inhibited cell proliferation of activated HSC/T-6cells in concentration-and time-dependent manner.CuE triggered the activation of caspase-3,cleaved the PARP,ration of bcl-2/bax,and cytochrom c protein in a time-and concentration-dependent manner.CuE decreased p-Erk/MAPK without effects on p-p38 and p-JNK.CuE inhibited the protein and mRNA expressions ofα-SMA,TIMP-1 and collagenⅠ in activated HSC-T6.CuE broadly blocked p-PI3 K,p-Akt,p-mTOR and p-p70S6 Kexpressions.CuE significantly increased phosphorylated AMPK expression as well as AICAR and metoformin.And metformin showed significantly higher activation of AMPK than AICAR.Ability of CuE on activation of AMPK was between AICAR and metformin.It′s also found that CuE significantly decreased p-mTOR as well as AICAR and metformin.CONCLUSION CuE could modulate HSC survival and activation as a potential anti-fibrotic agent for liver fibrosis treatment.The findings demonstrate that CuE induced HSC apoptosis via ERK/MAPK and PI3K/Akt-AMPK-mTOR signaling.     

Accelerated recovery of renal mitochondrial and tubule homeostasis with SIRT1/PGC-1α activation following ischemia–reperfusion injury

Kidney ischemia–reperfusion (I/R) injury elicits cellular injury in the proximal tubule, and mitochondrial dysfunction is a pathological consequence of I/R. Promoting mitochondrial biogenesis (MB) as a repair mechanism after injury may offer a unique strategy to restore both mitochondrial and organ function. Rats subjected to bilateral renal pedicle ligation for 22 min were treated once daily with the SIRT1 activator SRT1720 (5 mg/kg) starting 24 h after reperfusion until 72 h–144 h. SIRT1 expression was elevated in the renal cortex of rats after I/R + vehicle treatment (IRV), but was associated with less nuclear localization. SIRT1 expression was even further augmented and nuclear localization was restored in the kidneys of rats after I/R + SRT1720 treatment (IRS). PGC-1α was elevated at 72 h–144 h in IRV and IRS kidneys; however, SRT1720 treatment induced deacetylation of PGC-1α, a marker of activation. Mitochondrial proteins ATP synthase β, COX I, and NDUFB8, as well as mitochondrial respiration, were diminished 24 h–144 h in IRV rats, but were partially or fully restored in IRS rats. Urinary kidney injury molecule-1 (KIM-1) was persistently elevated in both IRV and IRS rats; however, KIM-1 tissue expression was attenuated in IRS rats. Additionally, sustained loss of Na⁺,K⁺–ATPase expression and basolateral localization and elevated vimentin in IRV rats was normalized in IRS rats, suggesting restoration of a differentiated, polarized tubule epithelium. The results suggest that SRT1720 treatment expedited recovery of mitochondrial protein expression and function by enhancing MB, which was associated with faster proximal tubule repair. Targeting MB may offer unique therapeutic strategy following ischemic injury.     

Inhibition of P2X7R modulates ECM deposition in HSCs and crosstalk with macrophages in liver fibrosis

OBJECTIVE Modulation of immune response and reduction of extracellular matrix(ECM)deposition are both essential in the therapy of liver fibrosis.Regulating P2 X7 R might be a potential therapeutic strategy to treat liver fibrosis, we investigated whether the blockade of P2 X7 R could reverse liver fibrosis and how P2 X7 R is involved in fibrogenesis during hepatic stellate cells(HSCs) and macrophages crosstalk. METHODS In vivo,liver fibrosis model was established by thioacetamide(TAA) intraperitoneal administration in male C57 BL/6 mice. In vitro, LX-2 cells were treated with TGF-β and LPS/ATP respectively. Supernatant from LPS/ATP stimulated THP-1 macrophages were supplemented to LX-2 cells to mimic cellular crosstalk between HSCs and macrophages. RESULTS Blockade of P2 X7 R with its selective antagonist A438079, not only decreased liver injury and ECM deposition but also ameliorated inflammation by inhibiting NLRP3 inflammasome, NF-κB activation and IL-1β production in TAA-induced liver fibrosis. And the recruitment of macrophages, monocytes and granulocytes were also inhibited. In TGF-β-stimulated LX-2 cells,ECM deposition was reduced by the inhibiting of P2 X7 RTLR4-NLRP3 axis. Protein synthesis and cleavage of IL-1β and its m RNA level was dramatically increased by LPS 4 h combined with ATP 30 min than those in HSC treated with LPS or ATP alone. Additionally, LX-2 cells primed with LPS/ATP greatly increased m RNA and protein expression of caspase-1, NLRP3 and P2 x7 R, as well as liver fibrosis markers, α-SMA and typeⅠcollagen.These events were remarkably suppressed by A438079 pretreatment. si RNA against P2 x7 R reduced protein expression of NLRP3 and α-SMA, and suppressed deposition and secretion of type Ⅰ collagen induced by LPS/ATP. Ectopic overexpression of P2 X7 R reduced the threshold of ECM deposition in HSCs induced by TGF-β.Inhibiting upstream receptors of NLRP3 inflammasome,P2 X7 receptor-selective antagonist(A438079), TLR4 inhibitor(CLI-095) reduced the fibrotic markers in both models of TGF-β and LPS/ATP-activated HSCs. The cultured medium of the THP-1 macrophages by LPS/ATP aggravated ECM deposition in LX-2 cells. The decreased IL-1β by the pharmacological inhibitors of P2 X7 R,caspase-1 and TLR4 treated to THP-1 macrophages attenuates ECM deposition in LX-2 cells. CONCLUSION Both ECM producing in HSCs and inflammatory cytokines secreting from macrophages were regulated by P2 X7 R, suggesting a therapeutic utility of P2 x7 R blockade in liver fibrosis treatment.     

AMPK活化对INS-1细胞胰岛素释放的影响

目的研究AMPK活化对INS-1细胞胰岛素释放的作用及其可能机制。方法体外培养INS-1细胞株,观察不同浓度(0.2,0.5和1.0mmol·L-1)AICAR(AMPK激动剂)作用不同时相点(8,12和24h)对细胞内胰岛素含量及高糖刺激的胰岛素释放的影响;AICAR(0.5mmol·L-1)与Compound C(10μmol·L-1,AMPK阻断剂)单独或共同作用INS-1细胞8h,采用两种PCR(RT-PCR和实时定量PCR)方法检测PPARα基因转录水平的变化,免疫沉淀检测PPARα蛋白表达。结果与正常对照组比较,AICAR(0.2,0.5和1mmol·L-1)作用8,12和24h,均抑制INS-1细胞高糖刺激的胰岛素释放及细胞内胰岛素含量。同时,AICAR诱发的AMPK活化能增强PPARα mRNA和蛋白水平的表达。结论AICAR诱导的AMPK活化可能通过调节PPARα表达抑制INS-1细胞高糖刺激的胰岛素释放。     

尼曼-匹克C1型类似蛋白1介导依泽替米贝对RAW264.7细胞脂质蓄积的抑制作用

目的观察肠道胆固醇吸收抑制剂依泽替米贝(ezetimibe)对RAW264.7细胞源性荷脂细胞脂质蓄积的影响并对其机制进行初步探讨。方法采用油红O染色、高效液相色谱法检测细胞内脂滴数量和细胞内脂质含量,Western blot对NPC1L1(Niemann-Pick type C1Like-1)进行定性和半定量检测。结果RAW264.7细胞中有NPC1L1蛋白表达。不同浓度(0、0.003、0.01和0.03mol.L-1)依泽替米贝预先孵育RAW264.7细胞24h或最佳浓度(0.03mol.L-1)预先孵育不同时间(0、6、12和24h)后,换50mg.L-1oxLDL继续孵育24h,结果显示不同浓度ezetimibe预先孵育后,细胞内脂滴数量与面积随着浓度的增加而逐渐减少;Ezetimibe预先孵育可减少细胞内脂质蓄积,并呈浓度和时间依赖性。其中0.03mol.L-1ezetimibe预先孵育24h组作用最明显,CE百分比较oxLDL单独孵育组减少了约47%±0.1%。结论小鼠源性巨噬细胞RAW264.7中存在NPC1L1蛋白表达;依泽替米贝能够减少RAW264.7细胞中NPC1L1蛋白表达;依泽替米贝抑制RAW264.7细胞中脂质蓄积。     

Metformin-induced stimulation of AMP-activated protein kinase in beta-cells impairs their glucose responsiveness and can lead to apoptosis

Metformin is an anti-diabetic drug that increases glucose utilization in insulin-sensitive tissues. The effect is in part attributable to a stimulation of AMP-activated protein kinase (AMPK). The present study demonstrates that metformin (0.5-2mM) also dose-dependently activates AMPK in insulin-producing MIN6 cells and in primary rat beta-cells, leading to increased phosphorylation of acetyl coA carboxylase (ACC). The maximal effect was reached within 12h and sustained up to 48h. After 24h exposure to metformin (0.5-1mM), rat beta-cells exhibited a reduced secretory and synthetic responsiveness to 10mM glucose, which was also the case following 24h culture with the AMPK-activator 5-amino-imidazole-4-carboxamide riboside (AICAR; 1mM). Longer metformin exposure (>24h) resulted in a progressive increase in apoptotic beta-cells as was also reported for AICAR; metformin-induced apoptosis was reduced by compound C, an AMPK-inhibitor. As with AICAR, metformin activated c-Jun-N-terminal kinase (JNK) and caspase-3 prior to the appearance of apoptosis. It is concluded that metformin-induced AMPK-activation in beta-cells reduces their glucose responsiveness and may, following sustained exposure, result in apoptosis.     

Survivin在PC12细胞对抗化学性缺氧损伤中的作用

目的探讨存活素(survivin)在PC12细胞对抗氯化钴(CoCl2)诱导损伤中的作用。方法应用不同浓度的CoCl2处理PC12细胞不同时间,建立化学性缺氧诱导PC12细胞损伤的实验模型。应用CCK-8比色法检测细胞存活率;Western-blot法检测CoCl2诱导缺氧与survivin表达间的量效(200～1000μmol·L-1)和时效(0～48h)关系。结果CoCl2可明显抑制PC12细胞的存活率,且呈浓度和时间依赖性。应用不同浓度CoCl2处理PC12细胞24h,在200～600μmol·L-1浓度范围内,呈浓度依赖性地促进survivin表达,600μmol·L-1CoCl2诱导survivin表达达高峰,超过此浓度,则随着CoCl2浓度的增加,survivin表达逐渐下降,CoCl2浓度达1000μmol·L-1时,survivin基本不表达;应用600μmol·L-1CoCl2处理PC12细胞,在0～36h时间范围内,呈时间依赖性地促进PC12细胞survivin的表达,但随着处理时间的延长,survivin的表达逐渐下降;加入2μmol·L-1Hsp90抑制剂17-丙烯胺基-17-去甲氧基格尔德霉素(17-AAG),不仅可以降低600μmol·L-1 CoCl2诱导的survivin高表达,而且加重了600μmol·L-1 CoCl2对PC12细胞的损伤作用,使细胞存活率降低。结论survivin表达上调可能是PC12细胞对抗化学性缺氧损伤的内在防御机制之一。     

Central AMPK contributes to sleep homeostasis in mice

AMP-activated protein kinase (AMPK) is an energy-sensing molecular signal involved in glucose and lipid metabolism. The known interaction of sleep with energy metabolism led us to investigate the role of central AMPK in sleep homeostasis. Sleep deprivation (SD) for 6 h increased p-AMPK protein in the hypothalamus and also increased the mRNA level of Ca²⁺/calmodulin (CaM)-dependent protein kinase kinase β (CaMKK2), an activator of AMPK, and carnitine palmitoyltransferase 1 (CPT1), a downstream signaling factor of AMPK. Central injection of compound C (CC), an inhibitor of AMPK, suppressed EEG delta power during NREM sleep, while 5-aminoimidazole-4-carboxamide riboside (AICAR), an activator of AMPK, enhanced EEG delta power. The treatment of both CC and AICAR attenuated rebound responses of delta power in NREM sleep after SD. These results indicate that central AMPK is involved in the regulation of sleep depth and sleep homeostasis.     

6种黄酮类化合物拮抗肝细胞毒性作用的比较

目的观察芹菜素、木犀草素、白杨素、高良姜素、山奈酚、黄芩素6种结构相近的黄酮类化合物对肝毒性物质诱导的人正常肝细胞株L-02细胞及小鼠原代肝细胞损伤的保护作用,并对其保护肝细胞损伤活性的强弱进行比较及结构分析。方法培养的L-02细胞及小鼠原代肝细胞分别给予10mmol·L~(-1)四氯化碳(CCl_4)、500μmol·L~(-1)牛磺酸脱氧胆酸(TDCA)、2μmol·L~(-1)川楝素(toosendanin,TSN)和25μmol·L~(-1)千里光碱(senecionine,SENE)诱导细胞凋亡。6种黄酮类化合物(100μmol·L~(-1))分别与细胞预孵15min后,加入肝毒性物质,48h后MTT法检测细胞存活率。结果与空白对照组相比,4种肝毒性药物都能明显降低肝细胞的存活率(P<0.01)。黄酮类化合物处理后,黄芩素和山奈酚能不同程度地提高肝细胞损伤模型组的细胞存活率(P<0.01)。其他4种黄酮类化合物对肝细胞存活率无显著作用。结论黄芩素和山奈酚具有抑制肝毒性物质诱导的L-02细胞和小鼠原代肝细胞毒性的作用,有潜在的抗氧化保肝活性,而芹菜素、木犀草素、白杨素、高良姜素无明显的拮抗肝毒性作用。     

TRPV1/SIRT1介导吴茱萸次碱抗AngⅡ诱导的血管平滑肌细胞衰老

目的探讨吴茱萸次碱(rutaecarpine,Rut)对长寿蛋白SIRT1表达及AngⅡ诱导的血管平滑肌细胞(vascular smooth muscle cells,VSMCs)衰老的影响。方法采用AngⅡ(1μmol·L^-1)孵育大鼠胸主动脉平滑肌细胞72 h,预先加入不同浓度的Rut(0.3、1、3μmol·L^-1),采用TRPV1拮抗剂CAPZ(10μmol·L^-1)和AMPK抑制剂Compound C(1μmol·L^-1)探讨TRPV1/AMPK是否介导Rut的保护效应。SA-β-Gal测定衰老细胞数目,DCFH-DA法测定细胞ROS水平。划痕愈合结合Transwell检测VSMCs迁移。Western blot检测VSMCs中长寿蛋白SIRT1和衰老相关蛋白p53、p21的表达以及p-AMPK水平。结果Rut明显地抑制AngⅡ诱导的VSMCs衰老和ROS生成,并抑制VSMCs迁移。预先给予TRPV1拮抗剂可取消Rut这一保护作用。AngⅡ可降低SIRT1的表达,给予Rut可剂量依赖性地恢复SIRT1的表达,且下调其下游衰老相关蛋白p53和p21的表达。AngⅡ可抑制p-AMPK,加入Rut能恢复p-AMPK水平。CAPZ和Compound C可消除Rut升高SIRT1表达的效应。结论Rut可上调SIRT1表达,抑制AngⅡ诱导的VSMCs衰老和迁移,其机制可能激活TRPV1/AMPK信号途径。     

鹅不食草心菊内酯对肝星状细胞活化的抑制作用机制研究

目的 研究鹅不食草心菊内酯(helenalin)对LX-2人肝星状细胞(HSCs)活化的抑制作用及其机制.方法 用白细胞介素-1β(IL-1β)20 ng·mL-1刺激LX-2细胞建立体外细胞模型,另取未刺激细胞作为正常组.将损伤细胞分为5组:模型组、阳性对照组[LY294002(磷脂酰肌醇3激酶/丝苏氨酸蛋白激酶通路...     

S-adenosylmethionine inhibits the activated phenotype of human hepatic stellate cells via Rac1 and Matrix metalloproteinases

ObjectiveTo investigate the effects of S-adenosylmethionine (SAM) on the proliferation, adhesion, migration, invasion and apoptosis of activated human hepatic stellate cells (HSCs) and to explore the relevant potential mechanisms.MethodsHuman HSCs LX-2 were cultured with SAM. The proliferation and adhesion were detected by CCK-8. Cell apoptosis rate were analyzed by flow cytometry, and cell migration and invasion were tested by the transwell assay. The expression of Rac1 and MMP-2 was identified by real-time PCR or Western blotting, and activated Rac1 was detected by GST pull-down assay. The activity of MMP-2 and MMP-9 was analyzed by substrate zymography.ResultsThe proliferation of LX-2 cells was inhibited by SAM, exhibiting a dose-dependent manner. Cell apoptosis rate induced by SAM was remarkably increased. SAM decreased the adhesion, migration and invasion of LX-2 cells. The expression and activation of Rac1 in LX-2 cells were significantly suppressed by SAM. In contrast, the activity of MMP-2 and MMP-9 was enhanced by SAM. SAM attenuated the up-regulated expression of Smad3/4 and Rac1 induced by TGF-β1.ConclusionSAM inhibits the proliferation, adhesion, migration and invasion of LX-2 cells in vitro probably via attenuating the expression and activation of Rac1 and up-regulating MMP-2 and MMP-9 expression, which possibly provide a molecular basis for potential application of SAM in the therapy of liver fibrosis.     

Formaldehyde alters triglyceride synthesis and very low-density lipoprotein secretion in a time-dependent manner

Formaldehyde is a common indoor air pollutant that is toxic to the liver. This study aimed to investigate the effects of formaldehyde on triglyceride metabolism in human hepatocellular carcinoma cells (HepG2). Cell viability was detected using a MTT (3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide) assay. Following treatment with different concentrations of formaldehyde for 24 and 48 h, the intra and extra-hepatocellular triglyceride (TG) content was determined using a chemical-enzymatic method; Western blotting was used to detect the levels of fatty acid synthesis and VLDL-related proteins. Our results showed that cell viability significantly decreased after formaldehyde treatment (0.5–12.5 mM, 24/48 h). Extracellular TG levels in the hepatocytes increased after formaldehyde treatment at 0.004 mM–0.1 mM for 24 h. SREBP-1c, ACC, FASN, and MTP, CES3 and DGAT1 proteins increased significantly after 24 h of formaldehyde treatment. Intracellular TG levels decreased for 48 h treatment of formaldehyde. AMPKα increased significantly in all tested groups and p-AMPK increased significantly after 0.1 mM formaldehyde treatment for 48 h. Our results indicated that short–term formaldehyde exposure balances triglyceride metabolism by promoting hepatocellular TG synthesis and VLDL secretion; Long-term formaldehyde disturbs the TG metabolism balance in the hepatocytes.     

cAMP-PKA-CREB信号通路在大鼠酒精性肝纤维化星状细胞模型中的作用

目的探讨cAMP-PKA-CREB信号通路在大鼠酒精性肝纤维化星状细胞模型中的作用。方法采用不同浓度乙醛不同时间间隔干预肝星状细胞(HSC),建立体外酒精性肝纤维化星状细胞模型;采用MTT法检测HSC增殖,确定造模浓度及时间;RT-PCR法检测HSC活化指标α-SMA mRNA表达情况;125I-cAMP放射免疫分析方法测定正常组与模型组HSC内cAMP含量;RT-PCR法测定PKA,CREB mRNA表达情况。结果采用浓度为200μmol.L-1乙醛刺激HSC 48 h可建立酒精性肝纤维化星状细胞模型;模型组α-SMA mRNA表达较正常组明显增强,模型组cAMP含量较正常组显著增加;PKA,CREB mRNA表达也较正常组明显增强。结论乙醛可刺激HSC增殖活化,其机制可能与其激活HSC cAMP-PKA-CREB信号通路有关。