Potential of ginsenoside Rg1 to treat aplastic anemia via mitogen activated protein kinase pathway in cyclophosphamide-induced myelosuppression mouse model

Aplastic anemia(AA)is a rare but serious condition in which the bone marrow fails to produce sufficient new blood cells,leading to fatigue,increased susceptibility to infection,and uncontrolled bleeding.In this editorial,we review and comment on an article by Wang et al published in 2024.This study aimed to evaluate the potential therapeutic benefits of ginsenoside Rg1 in AA,focusing on its protective effects and uncovering the underlying mechanisms.Cyclophosphamide(CTX)administration caused substantial damage to the structural integrity of the bone marrow and decreased the number of hematopoietic stem cells,thereby establishing an AA model.Compared with the AA group,ginsenoside Rg1 alleviated the effects of CTX by reducing apoptosis and inflammatory factors.Mechanistically,treatment with ginsenoside Rg1 significantly mitigated myelosuppression in mice by inhibiting the mitogen activated protein kinase signaling pathway.Thus,this study indicates that ginsenoside Rg1 could be effective in treating AA by reducing myelosuppression,primarily through its influence on the mitogen activated protein kinase signaling pathway.We expect that our review and comments will provide valuable insights for the scientific community related to this research and enhance the overall clarity of this article.

基于p38MAPK信号通路防治骨性关节炎的研究进展

骨性关节炎（osteoarthritis,OA）特征表现为关节软骨进行性退变、萎缩凋亡、脱落消失,关节骨缘及软骨下骨反应性增生、肥厚、纤维化等（[1]）。在中老年人中的发病率高达89%（[2]）。丝裂原活化蛋白激酶（mitogen activated protein kinases,MAPKs）是细胞内重要的信号传递者,参与细胞增殖、凋亡、分化、表型等多种生理过程的调节（[3]）。

西格列汀对糖尿病肾病P38丝裂原活性蛋白激酶信号途径的影响

糖尿病肾病（diabetic nephropathy,DN）是糖尿病的主要微血管并发症之一,目前已成为欧美国家以及我国终末期肾病的首要病因[1],给国民经济和个人造成巨大的经济和精神负担。足细胞裂孔隔膜上有很多蛋白参与其完整性的表达,这些蛋白的表达受损与蛋白尿的发生密切相关。Podocin蛋白即为众多裂孔隔膜蛋白之一[2]。丝裂原活化蛋白激酶（mitogen-activated protein kinase,

西格列汀对糖尿病肾病P38MAPK信号途径的影响

糖尿病肾病（diabetic nephropathy,DN）是糖尿病主要的微血管并发症之一,目前已成为欧美国家以及我国终末期肾病的首要病因,给国民经济和个人造成巨大的经济和精神负担。足细胞裂孔隔膜上有很多蛋白参与其完整性的表达,这些蛋白的表达受损与蛋白尿的发生密切相关。podocin蛋白即为众多裂孔隔膜蛋白之一。

有氧运动与饮食干预对肥胖小鼠睾丸氧化应激的影响

目的:通过对肥胖小鼠施加有氧运动与饮食干预,探索运动与饮食干预对肥胖小鼠睾丸氧化应激和p38MAPK-NF-κB通路中的作用。方法:随机将17只C57BL/6J小鼠分为正常饮食组(ND),37只分为高脂饮食组(HFD),高脂饮食脂肪占比40%,喂养12周后,HFD组剔除3只肥胖抵抗小鼠,其余34只肥胖造模成功;随后将ND组分为正常饮食对照组(NC,n=8),正常饮食运动组(NE,n=9),肥胖高脂饮食对照组(OC,n=8),肥胖高脂饮食运动组(OE,n=9),肥胖正常饮食组(ONC,n=8),肥胖正常饮食运动组(ONE,n=9),各组继续饲养8周,其中NE、OE和ONE组以速度20 m/min,60 min/d,6 d/week,进行8周跑台运动,末次运动后36~40 h取血和睾丸组织,ELISA检测血清睾酮和睾丸氧化应激(MDA、T-SOD、T-AOC)水平,RT-PCR和Western blot检测睾丸p38MAPK-NF-κB水平。结果:与NC组比较,OC组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显升高(P<0.01),睾丸SOD、睾丸系数和血睾酮明显降低(P<0.01);NE组小鼠体脂参数明显降低(P<0.05),血清睾酮明显升高(P<0.01)。与OC组比较,OE组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P<0.05或0.01),睾丸SOD和血睾酮水平明显升高(P<0.01);ONC组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P<0.01),睾丸SOD水平和睾丸系数明显升高(P<0.05);ONE组小鼠体脂参数、睾丸MDA和睾丸p38MAPK-NF-κB mRNA和蛋白水平明显降低(P<0.01),睾丸SOD、睾丸系数和血睾酮水平明显升高(P<0.01)。结论:肥胖引起小鼠睾丸发生氧化应激,上调睾丸p38MAPK-NF-κB水平,并降低血睾酮水平;运动、饮食和运动×饮食干预均能通过降低体脂,改善睾丸氧化应激,下调睾丸p38MAPK-NF-κB水平。

Hepatitis B virus,HBx mutants and their role in hepatocellular carcinoma

Hepatocellular carcinoma(HCC)is one of the leading causes of death induced by cancer in the modern world and majority of the cases are related to chronic hepatitis B virus(HBV)infection.HBV-encoded X protein(HBx)is known to play a pivotal role in the pathogenesis of viral induced HCC.HBx is a multifunctional protein of17 kDa which modulates several cellular processes by direct or indirect interaction with a repertoire of host factors resulting in HCC.HBX might interfere with several cellular processes such as oxidative stress,DNA repair,signal transduction,transcription,protein degradation,cell cycle progression and apoptosis.A number of reports have indicated that HBx is one of the most common viral ORFs that is often integrated into the host genome and its sequence variants play a crucial role in HCC.By mutational or deletion analysis it was shown that carboxy terminal of HBx has a likely role in protein-protein interactions,transcriptional transactivation,DNA repair,cell,signaling and pathogenesis of HCC.The accumulated evidence thus far suggests that it is difficult to understand the mechanistic nature of HBx associated HCC,and HBx mediated transcriptional transactivation and signaling pathways may be a major determinant.This article addresses the role of HBx in the development of HCC with particular emphasis on HBx mutants and their putative targets.

Rapid mitogen-activated protein kinase activation by transforming growth factor α in wounded rat intestinal epithelial cells

AIM To define signaling events initiating healing after intestinal epithelial injury, activation of mitogen activated protein kinase (MAPK) pathways was assessed after wounding using an in vitro model. METHODS Proteins isolated from wounded monolayers of nontransformed intestinal epithelial cells (IEC 6) were analyzed for tyrosine phosphorylation and MAPK expression by Western blot. Extracellular signal regulated kinase (ERK) 1, ERK2, and Raf 1 activities were assessed by immune complex kinase assays. RESULTS Tyrosine phosphorylation of several proteins including ERK1 was substantially increased 5 minutes after injury. Another MAPK, c Jun N terminal protein kinase (JNK), was also activated after wounding. Conditioned medium from wounded but not intact IEC 6 monolayers resulted in increased activity of ERK1, ERK2, and Raf 1 kinase. Wound conditioned medium stimulated proliferation of subconfluent IEC 6 cells compared with conditioned medium from intact IEC 6 cultures and contained higher amounts of transforming growth factor (TGF) α than supernatants of confluent IEC 6 cultures. Activation of ERK1 and ERK2 was partially inhibited by neutralizing anti TGF α. CONCLUSION Wounding of intestinal epithelial cells results in activation of Raf 1, ERK1, ERK2, and JNK1 MAPKs and subsequent cell proliferation in vitro. Activation of ERK1 and ERK2 is mediated in part by TGF α.

Caffeic acid phenethyl ester up-regulates antioxidant levels in hepatic stellate cell line T6 via an Nrf2-mediated mitogen activated protein kinases pathway

AIM To investigate the antioxidant effect of caffeic acid phenethyl ester (CAPE) in hepatic stellate cell-T6 (HSC-T6) cells cultured in vitro and the potential mechanisms. METHODS HSC-T6 cells were cultured in vitro and treated with various concentrations of CAPE for 24, 48 and 72 h, respectively. Cell proliferation was investigated using the MTT assay, and cell ultrastructural alterations were observed by transmission electron microscopy. Flow cytometry was employed to investigate the effects of CAPE on apoptosis and the levels of reactive oxygen species in HSC-T6 cells cultured in vitro. An enzyme immunoassay instrument was used to evaluate antioxidant enzyme expression. The effect on alpha-smooth muscle actin was shown using immunofluorescence. Gene and protein levels of Nrf2, related factors, and mitogen activated protein kinases (MAPKs), in HSC-T6 cells were detected using RT-PCR and Western blot, respectively. RESULTS CAPE inhibited the proliferation and activation of HSC-T6 cells cultured in vitro. CAPE increased the antioxidant levels and the translocation of Nrf2 from the cytoplasm to the nucleus in HSC-T6 cells. Moreover, the phosphorylation of MAPKs in cells decreased in response to CAPE. Interestingly, CAPE-induced oxidative stress in the cells was significantly attenuated by pretreatment with MAPKs inhibitors. CONCLUSION CAPE inhibits cell proliferation and up-regulates the antioxidant levels in HSC-T6 cells partly through the Nrf2-MAPKs signaling pathway.

Ornithine decarboxylase, mitogen-activated protein kinase and matrix metalloproteinase-2 expressions in human colon tumors

AIM: To investigate the expressions of omithine decarboxylase (ODC), MMP-2, and Erk, and their relationship in human colon tumors.METHODS: ODC activity, MMP-2 expression, and mitogenactivated protein (MAP) kinase activity (Erk phosphorylation) were determined in 58 surgically removed human colon tumors and their adjacent normal tissues, using [1-14C]-ornithine as a substrate, ELISA assay, and Western blotting, respectively.RESULTS: ODC activity, MMP-2 expression, and Erk phosphorylation were significantly elevated in colon tumors, compared to those in adjacent normal tissues. A significant correlation was observed between ODC activities and MMP-2 levels.CONCLUSION: This is the first report showing a significant correlation between ODC activities and MMP-2 levels in human colon tumors. As MMP-2 is involved in cancer invasion and metastasis, and colon cancer overexpresses ODC, suppression of ODC expression may be a rational approach to treat colon cancer which overexpresses ODC.

U0126 PREVENTS ERK PATHWAY PHOSPHORYLATION AND INTERLEUKIN-1β mRNA PRODUCTION AFTER CEREBRAL ISCHEMIA

Objective To study the role of extracellular signal-regulated kinase (ERK) in cerebral ischemia and the mechanism of protective effects of U0126 (1,4-diamino-2,3-dicyano-1,4-bis[2-aminophenylthio] butadiene) on ischemic brain. Methods Mice underwent left middle cerebral artery occlusion (MCAO) by introducing a suture in the lumen. U0126 was injected intravenously through the internal jugular vein. The immuno-activity of phosphorylated ERK1/2 (pERK1/2), phos-phorylated mitogen activated protein kinase kinase (pMEK), and phosphorylated Elk-1 (pElk-1) was assessed by Western blot analysis and immunohistochemistry. Interleukin (IL)-1βmRNA level was measured by ribonuclease protection assay. Results Phosphorylated ERK1/2 in 2 hours MCAO mice was down-regulated after intravenous injection of U0126. The inhibition was dose dependent and treatment time related. pMEK and pElk-1 were also reduced in a similar fashion after U0126 treatment. IL-1βmRNA increased after 1 and 2 hours of MCAO. After injection of U0126, it was down-regulated during 1 to 4 hours after MCAO. Conclusion Intravenous administration of the MEK inhibitor U0126 inhibits pMEK, pERK1/2, and pElk-1 up-regulation induced by cerebral ischemia. The protective effect of U0126 against ischemic injury is probably resulted from the reduction of IL-1βmRNA via the inhibition of ERK pathway.

Neuroprotective mechanisms of rutin for spinal cord injury through anti-oxidation and anti-inflammation and inhibition of p38 mitogen activated protein kinase pathway

Rutin has anti-inflammatory, antioxidant, anti-viral, anti-tumor and immune regulatory effects. However, the neuroprotective effects of rutin in spinal cord injury are unknown. The p38 mitogen activated protein kinase （p38 MAPK） pathway is the most important member of the MAPK family that controls inflammation. We assumed that the mechanism of rutin in the repair of spinal cord injury is associated with the inhibition of p38 MAPK pathway. Allen’s method was used to establish a rat model of spinal cord injury. The rat model was intraperitoneally injected with rutin （30 mg/kg） for 3 days. After treatment with rutin, Basso, Beattie and Bresnahan locomotor function scores increased. Water content, tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 levels, p38 MAPK protein expression and caspase-3 and -9 activities in T8–9 spinal cord decreased. Oxidative stress related markers superoxide dismutase and glutathione peroxidase levels increased in peripheral blood. Rutin exerts neuroprotective effect through anti-oxidation, anti-inflammation, anti-apoptosis and inhibition of p38 MAPK pathway.

Prosaposin ablation inactivates the MAPK and Akt signaling pathways and interferes with the development of the prostate gland

<abstract>The recent development of a prosaposin -/- mouse model has allowed the investigation of the role of prosaposin in the development of the male reproductive organs. A morphometric analysis of the male reproductive system of 37 days old mice revealed that prosaposin ablation produced a 30 % reduction in size and weight of the testes, 37 % of the epididymis, 75 % of the seminal vesicles and 60 % of the prostate glands. Light microscopy (LM) showed that smaller testis size from homozygous mutant mice was associated with reduced spermiogenesis. Both, dorsal and ventral lobules of the prostate glands were underdeveloped in the homozygous mutant. LM analysis also showed that prostatic alveoli were considerably smaller and lined by shorter epithelial cells in the homozygous mutant. Smaller tubular diameter and shorter undifferentiated epithelial cells were also observed in seminal vesicles and epididymis. In the efferent ducts of the homozygous mutant mice, the epithelium was composed exclusively of ciliated cells in contrast to the heterozygotes, which showed the presence of nonciliated cells. Radioimmunoassays demonstrated that testosterone levels were normal or higher in mice with the inactivated prosaposin gene. Immunostaining of prostate sections with an anti-androgen receptor antibody showed that the epithelial cells lining the alveoli express androgen receptor in both the heterozygous and homozygous tissue. Similarly, sections immunostained with antibodies to the phosphorylated MAPKs and Akts strongly reacted with tall prostatic secretory cells in prostate from heterozygous mouse. On the other hand, the epithelial cells in the homozygous prostate remained unstained or weakly stained. These findings demonstrate that inactivation of the prosaposin gene affected the development of the prostate gland and some components of the MAPK pathway. 63 )

Metabolic derivatives of alcohol and the molecular culpritsof fibro-hepatocarcinogenesis:Allies or enemies?

Chronic intake of alcohol undoubtedly overwhelms the structural and functional capacity of the liver by initiating complex pathological events characterized by steatosis,steatohepatitis,hepatic fibrosis and cirrhosis.Subsequently,these initial pathological events are sustained and ushered into a more complex and progressive liver disease,increasing the risk of fibrohepatocarcinogenesis.These coordinated pathological events mainly result from buildup of toxic metabolic derivatives of alcohol including but not limited to acetaldehyde(AA),malondialdehyde(MDA),CYP2E1-generated reactive oxygen species,alcohol-induced gut-derived lipopolysaccharide,AA/MDA protein and DNA adducts.The metabolic derivatives of alcohol together with other comorbidity factors,including hepatitis B and C viral infections,dysregulated iron metabolism,abuse of antibiotics,schistosomiasis,toxic drug metabolites,autoimmune disease and other non-specific factors,have been shown to underlie liver diseases.In view of the multiple etiology of liver diseases,attempts to delineate the mechanism by which each etiological factor causes liver disease has always proved cumbersome if not impossible.In the case of alcoholic liver disease(ALD),it is even more cumbersome and complicated as a result of the many toxic metabolic derivatives of alcohol with their varying liver-specific toxicities.In spite of all these hurdles,researchers and experts in hepatology have strived to expand knowledge and scientific discourse,particularly on ALD and its associated complications through the medium of scientific research,reviews and commentaries.Nonetheless,the molecularmechanisms underpinning ALD,particularly those underlying toxic effects of metabolic derivatives of alcohol on parenchymal and non-parenchymal hepatic cells leading to increased risk of alcohol-induced fibrohepatocarcinogenesis,are still incompletely elucidated.In this review,we examined published scientific findings on how alcohol and its metabolic derivatives mount cellular attack on each hepatic cell and the underlying molecular mechanisms leading to disruption of core hepatic homeostatic functions which probably set the stage for the initiation and progression of ALD to fibro-hepatocarcinogenesis.We also brought to sharp focus,the complex and integrative role of transforming growth factor beta/small mothers against decapentaplegic/plasminogen activator inhibitor-1 and the mitogen activated protein kinase signaling nexus as well as their cross-signaling with toll-like receptormediated gut-dependent signaling pathways implicated in ALD and fibro-hepatocarcinogenesis.Looking into the future,it is hoped that these deliberations may stimulate new research directions on this topic and shape not only therapeutic approaches but also models for studying ALD and fibro-hepatocarcinogenesis.

PRESENT STATUS OF RESEARCH ABROAD CONCERNING THE EFFECT OF ACUPUNCTURE AND MOXIBUSTION ON IMMUNOLOGIC FUNCTIONS

Much research has been conductedabroad in recent years concerningacupuncture and moxibustion on theimmunologic functions of the organism.Anoutline of this is presented as follows.EFFECTS OF ACUPUNCTUREAND MOXIBUSTION ON NORMALIMMUNOLOGIC FUNCTIONS

Insulin-like growth factor binding protein-5 influences pancreatic cancer cell growth

AIM： To investigate the functional significance of insulin-like growth factor binding protein-5 （IGFBP-5） overexpression in pancreatic cancer （PaC）.METHODS： The effects of IGFBP-5 on cell growth were assessed by stable transfection of BxPC-3 and PANC-1 cell lines and measuring cell number and DNA synthesis. Alterations in the cell cycle were assessed by flow cytometry and immunoblot analyses. Changes in cell survival and signal transduction were evaluated after mitogen and phosphatidylinositol activated protein kinase 3-kinase （PI3K） inhibitor treatment.RESULTS： After serum deprivation, IGFBP-5 expression increased both cell number and DNA synthesis in BxPC-3 cells, but reduced cell number in PANC-1 cells. Consistent with this observation, cell cycle analysis of IGFBP-5-expressing cells revealed accelerated cell cycle progression in BxPC-3 and G2/M arrest of PANC-1 cells. Signal transduction analysis revealed that Akt activation was increased in BxPC-3, but reduced in PANC-1 cells that express IGFBP-5. Inhibition of PI3K with LY294002 suppressed extracellular signal-regulated kinase-1 and -2 （ERK1/2） activation in BxPC-3, but enhanced ERK1/2 activation in PANC-1 cells that express IGFBP-5. When MEK1/2 was blocked, Akt activation remained elevated in IGFBP-5 expressing PaC cells; however, inhibition of PI3K or MEK1/2 abrogated IGFBP-5-mediated cell survival.CONCLUSION： These results indicate that IGFBP-5 expression affects the cell cycle and survival signal pathways and thus it may be an important mediator of PaC cell growth.

Sequencing and expression analysis of CD3γ/δ and CD3ε chains in mandarin fish, Siniperca chuatsi

The genomic and cDNA sequences of the CD3γ/δ and CD3ε homologues in the mandarin fish, Siniperca chuatsi, were determined. As in other vertebrate CD3 molecules, the deduced amino acid sequences of mandarin fish CD3γ/δ and CD3ε contained conserved residues and motifs, such as cysteine residues and CXXC and immunoreceptor tyrosine-based activation motifs. However, mandarin fish CD3γ/δ and CD3ε showed some differences to their mammalian counterparts, specifically the absence of a negatively charged residue in the transmembrane region of CD3γ/δ. Additionally, while an N-glycosylation site was present in CD3c, the site was not observed in CD3γ/δ. The CD3γ/δ and CD3ε subunit sequences contain six and five exons, respectively, consistent with homologues from Atlantic salmon, Salmo salar. Phylogenetic analysis also revealed that CD3γ/δ and CD3ε in mandarin fish are closely related to their counterparts in Acanthopterygian fish. Real-time PCR showed CD3γ/δ and CD3ε were expressed mainly in the thymus and spleen in normal healthy fish and, to a lesser extent, in mucosal-associated lymphoid tissues, such as the intestine and gills. When lymphocytes isolated from head kidney were treated with the mitogens phytohemagglutinin, concanavalin, and polyriboinosinic polyribocytidylic acid, mRNA expression levels of CD3γ/δ and CD3ε were significantly elevated within 12 h of treatment. This indicated the presence of T lymphocytes in the head kidney of teleost fish, and also the recognition of mitogens by the lymphocytes. Mandarin fish infected with the bacterial pathogen Flavobacterium columnare also showed an increase in the expression of CD3γ/δ and CD3ε mR_NA, indicating that CD3γ/δ and CD3ε lymphocytes are involved in the immune response of this species.

Bone morphogenetic protein 2-induced human dental pulp cell differentiation involves p38 mitogen-activated protein kinase-activated canonical WNT pathway

Both bone morphogenetic protein 2（BMP2） and the wingless-type MMTV integration site（WNT）/p-catenin signalling pathway play important roles in odontoblast differentiation and dentinogenesis.Cross-talk between BMP2 and WNT/p-catenin in osteoblast differentiation and bone formation has been identified.However,the roles and mechanisms of the canonical WNT pathway in the regulation of BMP2 in dental pulp injury and repair remain largely unknown.Here,we demonstrate that BMP2 promotes the differentiation of human dental pulp cells（HDPCs） by activating WNT/p-catenin signalling,which is further mediated by p38mitogen-activated protein kinase（MAPK） in vitro.BMP2 stimulation upregulated the expression of p-catenin in HDPCs,which was abolished by SB203580 but not by Noggin or LDN193189.Furthermore,BMP2 enhanced cell differentiation,which was not fully inhibited by Noggin or LDN193189.Instead,SB203580 partially blocked BMP2-induced p-catenin expression and cell differentiation.Taken together,these data suggest a possible mechanism by which the elevation of p-catenin resulting from BMP2 stimulation is mediated by the p38 MAPK pathway,which sheds light on the molecular mechanisms of BMP2-mediated pulp reparative dentin formation.

Xuebijing alters tumor necrosis factor-alpha, interleukin-1beta and p38 mitogen activated protein kinase content in a rat model of cardiac arrest following cardiopulmonary resuscitation

We established a rat model of cardiac arrest by clamping the endotracheal tube of adult rats at expiration. Twenty-four hours after cardiopulmonary resuscitation, nerve cell injury and expression of tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase content were increased. Rats injected with Xuebijing, a Chinese herb compound preparation, exhibited normal cellular structure and morphology, dense neuronal cytoplasm, and decreased tumor necrosis factor-α, interleukin-1β, and p38 mitogen activated protein kinase expression at 24 hours following cardiopulmonary resuscitation. These data suggest that Xuebijing can attenuate neuronal injury induced by hypoxia and reperfusion during cardiopulmonary resuscitation.

Vasopressin decreases neuronal apoptosis during cardiopulmonary resuscitation

The American Heart Association and the European Resuscitation Council recently recommend- ed that vasopressin can be used for cardiopulmonary resuscitation, instead of epinephrine. However, the guidelines do not discuss the effects of vasopressin during cerebral resuscitation. In this study, we intraperitoneally injected epinephrine and/or vasopressin during cardiopul- monary resuscitation in a rat model of asphyxial cardiac arrest. The results demonstrated that, compared with epinephrine alone, the pathological damage to nerve cells was lessened, and the levels of c-Iun N-terminal kinase and p38 expression were significantly decreased in the hippo- campus after treatment with vasopressin alone or the vasopressin and epinephrine combination. No significant difference in resuscitation effects was detected between vasopressin alone and the vasopressin and epinephrine combination. These results suggest that vasopressin alone or the vasopressin and epinephrine combination suppress the activation of mitogen-activated protein kinase and c-Iun N-terminal kinase signaling pathways and reduce neuronal apoptosis during cardiopulmonary resuscitation.

Regulation of Hepatitis C Virus Replication and Gene Expression by the MAPK-ERK Pathway

The mitogen activated protein kinases-extracellular signal regulated kinases （MAPK-ERK） pathway is involved in regulation of multiple cellular processes including the cell cycle. In the present study using a Huh7 cell line Conl with an HCV replicon, we have shown that the MAPK-ERK pathway plays a significant role in the modulation of HCV replication and protein expression and might influence IFN-a signalling. Epithelial growth factor （EGF） was able to stimulate ERK activation and decreased HCV RNA load while a MAPK-ERK pathway inhibitor U0126 led to an elevated HCV RNA load and higher NS5A protein amounts in Conl cells. It could be further demonstrated that the inhibition of the MAPK-ERK pathway facilitated the translation directed by the HCV internal ribosome entry site. Consistently, a U0126 treatment enhanced activity of the HCV reporter replicon in transient transfeetion assays. Thus, the MAPK-ERK pathway plays an important role in the regulation of HCV gene expression and replication. In addition, cyclin-dependent kinases （CDKs） downstream of ERK may also be involved in the modulation of HCV replication since roscovitine, an inhibitor of CDKs had a similar effect to that of U0126. Modulation of the cell cycle progression by cell cycle inhibitor or RNAi resulted consistently in changes of HCV RNA levels. Further, the replication of HCV replicon in Conl cells was inhibited by IFN-~z. The inhibitory effect of IFN-CZ could be partly reversed by pre-incubation of Con-1 cells with inhibitors of the MAPK-ERK pathway and CDKs. It could be shown that the MAPK-ERK inhibitors are able to partially modulate the expression of interferon-stimulated genes.