Effect of chronic administration of L-thyroxine on Ca2+/calmodulin-dependent protein kinaseⅡ in rat myocardium

AIM: To investigate the effect of chronic injection of L-thyroxine on Ca²⁺/calmodulin-dependent protein kinaseⅡ (CaMKII) and to explore whether CaMKII directly mediates hyperthyroidism-induced cardiac hypertrophy. METHODS: Twenty male Sprague-Dawley rats were randomly divided into hyperthyroid group and control group with 10 animals each. The animal model was produced by intraperitoneal injection of L-thyroxine (0.2 mg·kg^-1·d^-1) for 3 months. The control animals only received saline vehicle in the same procedures. Heart weight (HW), heart-to-body weight ratio (HW/BW), left ventricular-to-body weight ratio (LVW/BW) and diameter of cardiac myocytes were measured to evaluate cardiac hypertrophy. The ratio of perivascular collagen area to vascular luminal area (PVCA/VA) was used to represent myocrdial fibrosis. Moreover, the mRNA expression of CaMKII and the protein level of CaMKII were measured by real-time RT-PCR and Western blotting, respectively. RESULTS: Intraperitoneal injection of L-thyroxine for 3 months significantly increased HW/BW, LVW/BW, PVCA/VA and diameter of cardiac myocytes by 1.87, 1.84, 1.94 and 2.15 folds, respectively (P<0.05 or P<0.01) as compared with control group. The results of real-time RT-PCR revealed that L-thyroxine injection caused a 60% reduction in the mRNA level of cardiac CaMKII (P<0.05). Furthermore, the results of Western blotting confirmed that the protein expression level of cardiac CaMKII in L-thyroxine group diminished by 21% (P<0.05), but accompanied by a 1.58-fold enhancement of phosphorylated activity of CaMKII (P<0.05). CONCLUSION: Thyroxine decreases the expression level of cardiac CaMKII and increases the activity of CaMKII in the chronic hyperthyroid-induced hypertrophic heart, suggesting that CaMKII participates in the formation and maintenance of cardiac hypertrophy induced by hyperthyroidism in a balanced way.     

Effect of high temperature exposure time during flower bud formation on the occurrence of double pistils in ‘Satohnishiki’ sweet cherry

Exposure time of trees to high temperatures during flower differentiation influenced the occurrence of double pistils in ‘Satohnishiki’ sweet cherry. Mature trees were grown under both early and late forcing, and under non-forcing conditions until harvest in a commercial orchard located in Kagawa, southwestern Japan. In mid-July, when the maximum temperature began to rise rapidly following the rainy season, petal and stamen primordia had been formed in the buds under early forcing (93%) and late forcing (69%) conditions, but under non-forcing conditions most of the buds were still at the stage of sepal differentiation. Pistil doubling rarely occurred under forcing conditions, whereas 10.3% of the flowers developed double pistils under non-forcing conditions. In another experiment, potted trees were exposed to high temperatures (35°C/25°C, day/night) for 15 days at intervals of 15 days during the period from late-June to early-September. High temperature induced double pistils most severely in the buds that contained sepal and petal primordia at the beginning of the treatment, and the frequency of occurrence of double pistils was slightly lower in the buds treated at the earlier stage of flower differentiation. On the other hand, high temperature had little effect on pistil doubling in buds with differentiated stamen and pistil primordia. These results suggest that (1) the buds are most sensitive to the induction of double pistils at high temperatures at the transition stage from sepal to petal differentiation, and (2) forcing culture can be applied to sweet cherry production in warm areas to reduce double pistil formation by avoiding the exposure of buds to high temperatures while the buds are still in the sensitive period.     

Effect of Ca2+/calmodulin-dependent protein kinaseⅡinhibitor KN-93 on late sodium current in rabbits model of heart failure

AIM: To investigate the change of late sodium current (I_NaL) and the effect of Ca²⁺/calmodulin-dependent protein kinaseⅡ (CaMKⅡ) inhibitor KN-93 on I_NaL in the cardiomyocytes after isoproterenol-induced heart fai-lure (HF) in rabbits. METHODS: The rabbit model of HF was induced by injecting isoproterenol (300 μg·kg^-1·d^-1) for 15 d. One month later, all rabbits received by echocardiography and HE staining to observe the morphological changes of myocardium for evaluating the HF model. The protein expression of Na_V1.5, CaMKⅡδ and phosphorylated CaMKⅡδ was determined by Western blot. The ventricular myocytes were isolated from the rabbits of normal saline (NS) group and HF group by Langendorff perfusion, and the whole-cell patch-clamp technique was used to record I_NaL. RESULTS: Compared with NS group, the heart rate in HF group was increased (P<0.01), the ventricular cavity was enlarged (P<0.05), and the cardiac function was decreased (P<0.01). Compared with NS group, the cardiomyocytes in HF group arranged in disorder, vacuolar degeneration and myocardial interstitial edema were observed, and fibrous tissue increased. The protein levels of Na_V1.5, CaMKⅡδ and phosphorylated CaMKⅡδ in HF group were higher than those in NS group (P<0.01). I_NaL in HF group significantly increased compared with NS group (P<0.01). After adding sea anemone toxin Ⅱ (ATXⅡ), the density of I_NaL in HF group and NS group was significantly increased, but that in HF group increased more obviously than that in NS group (P<0.01). After ATXⅡ had induced stable current, we added KN-93 into NS group and HF group, and we found that the ATXⅡ-increased I_NaL in NS group and HF group was significantly decreased (P<0.05).CONCLUSION: CaMKⅡ inhibitor KN-93 inhibits the increase in I_NaL in HF rabbits, which may be related to the activity of CaMKⅡδ and the regulation of CaMKⅡ δ on I_NaL.     

Effect of tanshinone ⅡA on liver lipid deposition and ferroptosis-related protein expression in ApoE-/- mice

AIM To observe the effect of tanshinone ⅡA on liver lipid deposition and ferroptosis-related protein expression in ApoE^-/- mice. METHODS Thirty-two ApoE^-/- mice were randomly divided into model group, high-dose (60 mg/kg) tanshinone ⅡA group, low-dose (30 mg/kg) tanshinone ⅡA group and simvastatin group, and C57BL/6J mice (n=8) were used as normal control group. The mice in normal control group were given the basic feeding, while the others were given high-fat diet. The mice in tanshinone ⅡA groups and simvastatin group were given corresponding drugs. The mice in normal control group and model group were intraperitoneally injected with equal volume of saline. Eight weeks later, the serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were tested by automatic biochemistry analyzer. The liver tissues were stained with HE and oil red O. The contents of reactive oxygen species (ROS) and glutathione (GSH) in liver tissues of the mice were measured by commercially available kits. The liver glutathione peroxidase 4 (GPX4) and p53 were detected by immunohistochemical method. The protein and mRNA expression levels of ferroptosis-related factors GPX4, xCT/SLC7A11, p53 and ferritin heavy chain 1 (FTH1) were determined by Wes automatic Western blot quantitative analysis system and RT-qPCR. RESULTS Compared with normal control group, the serum levels of TC, TG and LDL-C in model group were increased significantly (P<0.05 or P<0.01), and HDL-C did not change significantly. The fat vacuoles were clearly visible in liver tissue. The content of ROS in liver tissue was increased significantly,and GSH was decreased significantly (P<0.01). The mRNA and protein expression levels of p53 were increased significantly, and GPX4, xCT/SLC7A11 and FTH1 were decreased significantly (P<0.05 or P<0.01). Compared with model group, tanshinone ⅡA significantly decreased the serum levels of TC, TG and LDL-C (P<0.05 or P<0.01), and HDL-C did not change significantly. High-dose and low-dose tanshinoneⅡA also significantly decreased the degree of steatosis, and the size of lipid droplets. The content of ROS in liver tissues was decreased significantly, and GSH was increased significantly (P<0.01). The mRNA and protein expression levels of GPX4, xCT/SLC7A11 and FTH1 were increased significantly, and p53 were decreased significantly (P<0.05 or P<0.01). CONCLUSION Tanshinone ⅡA reduces liver lipid deposition and lipid peroxidation damage in ApoE^-/- mice, which may be related to the intervention of ferroptosis-related proteins in the liver cells.     

Effects of ClC-3 knockdown-induced TNF-α/IL-10 imbalance in rat DRG on voltage-gated sodium channel expression and mechanical allodynia

AIM To investigate the effect of ClC-3 chloride channel/antiporter knockdown in rat dorsal root ganglion (DRG) on voltage-gated sodium channel expression in neurons and mechanical allodynia in rats. METHODS Adeno-associated virus carrying ClC-3 shRNA (AAV-ClC-3 shRNA) was injected intrathecally to knock down ClC-3 expression in DRG tissues of adult SD rats. The mRNA and protein expression levels of ClC-3, cytokines and voltage-gated sodium channels were detected by RT-qPCR, immunofluorescence and Western blot. The mechanical sensitivity was assessed using von Frey hairs and up-down method. RESULTS Intrathecal injection of AAV-ClC-3 shRNA decreased ClC-3 expression in the DRG tissues and induced mechanical allodynia in the rats. Knockdown of ClC-3 up-regulated the expression levels of Nav1.3, Nav1.7, Nav1.8 and Nav1.9 in the DRG tissues. Knockdown of ClC-3 increased tumor necrosis factor-α (TNF-α) and decreased interleukin-10 (IL-10) levels in the DRG tissues. CONCLUSION Knockdown of ClC-3 in rat DRG tissues induces TNF-α/IL-10 imbalance and increases expression of voltage-gated sodium channels, thus contributing to mechanical allodynia.     

Effect of salvianolic acid B on expression of TGF-β1 receptors and Smad2 in activated mesangial cells

AIM: To study the mechanisms of salvianolic acid B (Sal B)antagonizing mesangial cell activation and kidney fibrosis through investigating the effect of Sal B on expression of transforming growth factor-β₁ (TGF-β₁) receptors and Smad2 in TGF-β₁-stimulated renal mesangial cell activation. METHODS: Mesangial cells was isolated and purified from rat kidney. TGF-β₁ was used to establish rat primary mesangial cell activation model and Smad2,Smad7 protein expression was detected. Sal B (10^-6 mol/L and 10^-5 mol/L) was employed to treat the cells; α-smooth muscle actin(α-SMA) expression was analyzed by immunofluorescence staining and Western blotting. Mesangial cells were treated with Sal B alone or additional with TGF-β₁,and TGF-β₁ receptor Ⅰ (TβRⅠ),TGF-β₁ receptorⅡ (TβRⅡ),Smad2 phosphorylation and Smad2 protein expression was determined by Western blotting. RESULTS: Cell ular model was established by incubating with 5 μg/L TGF-β₁ for 24 h,and in early stage Smad2 was significantly phosphorylated. Sal B (10^-6 mol/L and 10^-5 mol/L) could inhibit α-SMA expression,which was the biomarker of activated mesangial cells. In addition,in Sal B group,the protein expression of TβRⅠand TβRⅡ was significantly down-regulated while Smad2 phosphorylation in mesangial cells was inhibited. CONCLUSION: Sal B inhibits the TGF-β₁-Smad pathway,the protein expression of TβRⅠ,TβRⅡ and Smad2 phosphorylation in mesangial cells,which is probably one of the mechanisms of Sal B alleviating kidney fibrosis.     

Effect of Kang Xianling decoction on TGF-β1-Smad pathway in a unilateral ureteral obstruction rat model

AIM: To study the effect of Kang Xianling decoction,comprised of dahuang,danshen,taoren,niuxi and danggui,on TGF-β₁-Smad pathway in unilateral ureteral obstruction rat model.METHODS: Eighteen male SD rats were divided into 3 groups,sham group,model group and model group treated with Kang Xianling decoction randomly.Renal interstitial fibrosis model was established in rats by unilateral ureteral obstruction (UUO).After treatment for additional 14 d,parameters of hydroxyproline in obstructed kidney from 3 groups were analyzed.Rats were sacrificed and the pathological statuses of their kidneys were checked by HE staining and electron microscopy.Transforming growth factor-β₁ (TGF-β₁) mRNA in kidney tissue was determined by RT-PCR.TGF-β₁ receptor Ⅰ (TβRⅠ),TGF-β₁ receptorⅡ (TβRⅡ),phosphorylated Smad2 and Smad2 protein were determined by Western blotting.RESULTS: Parameters of hydroxyproline in animals of model group were significantly increased than those in sham operation group (P<0.05).The mRNA expression of TGF-β₁ and the protein expression of TβRⅠ,TβRⅡ,phosphorylated Smad2 and Smad2 in kidney tissue of animals in model group were significantly up-regulated.After intervention with Kang Xianling decoction,the above-mentioned up-regulated parameters,except TGF-β₁,were all significantly inhibited.Compared to model group,the pathological changes in renal tissues in treatment group were remarkable improved.CONCLUSION: Kang Xianling decoction inhibits the TGF-β₁-Smad pathway and the protein expression of TβRⅠ,TβRⅡ,phosphorylated Smad2 and Smad2,so as to decrease the level of collagen in obstructed kidney and to alleviate the renal interstitial fibrosis in UUO rats.     

Effect of oscillating temperature on the expression of two aquaporin genes (Pp- × TIP1, Pp-PIP2) involved in regulating intercellular water status in flower buds of peach

Summary

We studied the effects of temperature changes on the water status of floral buds in peach during ecodormancy by an analysis of aquaporin (AQP) gene expression and magnetic resonance imaging of the upper part of the bud, the bud base, the bud trace, and the bud cushion. Expression levels of mRNAs of the water channel genes, Pp- TIP1 and Pp-PIP2, in the tonoplast and plasma membrane reflected the temperature oscillations: high temperatures increased mRNA levels and low temperatures decreased them, irrespective of the duration of either treatment.The T₂ relaxation time of the buds, especially in the floral primordia, was significantly longer under oscillating temperature conditions than under a consistently high temperature. The period of high-temperature during the oscillating temperature regime accelerated water flow in the bud, but delayed bud growth. Disruption of the water balance by excessive water in the primordia under oscillating temperatures may be one reason for the delay in bud growth.     

Effect of rosiglitazone on SREBP-1 and TGF-β1 expressions and accumulation of ECM in renal tubular cells of Wistar rats treated with high fat diet

AIM: To study the effect of high fat diet on the expression of sterol regulatory element biding protein-1 (SREBP-1) and transforming growth factor β1 (TGF-β1) in renal tubular cells and rosiglitazone intervention. METHODS: Wistar rats were treated with high fat diet and rosiglitazone for 3 months. The serum glucose, serum insulin and serum triglyceride were detected. Oil Red O staining was used to observe the renal lipid deposit and Masson staining was for the detection of ECM accumulation. SREBP-1, TGF-β1 and FN protein were determined by the methods of immunohistochemistry and Western blotting. SREBP-1 mRNA was detected by in situ hybridization. RESULTS: Rosiglitazone prevented effectively the increase in serum glucose, serum insulin and serum triglyceride resulted from high fat diet. High fat diet led to lipid droplet formation in renal tubular cells and interstitial ECM accumulation, which was decreased by rosiglitazone treatment. Compared to normal rats, SREBP-1 protein and SREBP-1 mRNA showed high expressions in high fat diet rats that were lowered by rosiglitazone. The precursor segment and mature segment of SREBP-1 protein were decreased by 27.39% and 27.32%. Similarly, the high expressions of TGF-β1 and FN protein in kidney of high fat diet rats were also prevented by rosiglitazone intervention. Compared to high fat diet rats, the expression of TGF-β1 in rosiglitazone treatment rats was lowered by 19.14%. CONCLUSION: Rosiglitazone prevents effectively the over-expression of SREBP-1 and TGF-β1 in renal tubular cells, and decreases lipid accumulation and ECM production in rats fed with high fat diet.     

Effects of Astragalus injection combined with puerarin injection on expression of BMP-7 and TGF-β1 in type 2 diabetic KKAy mouse kidney

AIM: To observe the effects of Astragalus injection combined with puerarin injection on the expression of transforming growth factor beta 1 (TGF-β₁) and bone morphogenetic protein 7 (BMP-7) in the kidney of type 2 diabetic KKA^y mouse. METHODS: The male KKA^y mice of 14 weeks old were randomly divided into model group and Astragalus injection combined with puerarin injection treatment (Astragalus+puerarin) group. The age-matched male C57BL/6J mice were selected as normal group. The general conditions and body weight of the mice were observed. Blood glucose (BG), triglyceride (TG), cholesterol (TC) and serum creatinine (SCr) were examined at the 20th, 24th and 28th week. The protein expression of renal TGF-β₁ was determined by immunohistochemical method. The mRNA expression of BMP-7 and TGF-β₁ was detected by RT-PCR. RESULTS: Compared with normal group, the body weight, BG, TG, TC and SCr increased significantly in model group. TGF-β₁ expression at protein and mRNA levels was increased, while mRNA expression of BMP-7 was decreased in KKA^y mice. Compared with model group, the body weight, BG, TG, TC and SCr reduced in Astragalus+puerarin group. The mRNA expression of BMP-7 in the renal tissues was higher, and TGF-β₁ expression at mRNA and protein levels was significantly lower in Astragalus+puerarin group than those in model group. CONCLUSION: Astragalus injection combined with puerarin injection has renal protective effects on type 2 diabetic KKA^y mice. The mechanism may be related to restoring BMP-7 expression and reducing the overexpression of TGF-β₁ in renal tissues.     

Effect of Mailuoning local perfusion on Wnt/β-catenin and Notch signaling pathways in crush injury syndrome model pigs

AIM To investigate the effects of local perfusion of Mailuoning on Wnt/β-catenin and Notch signaling pathway in crush injury syndrome model pigs. METHODS A total of 24 Bama mini pigs were randomly divided into normal control group, model group, normal perfusion group and Mailuoning perfusion group, with 6 in each group. Except for normal control group, the other groups were established crush injury model. After modeling, the blood supply of the pigs in model group was immediately restored. The normal perfusion group and Mailuoning perfusion group were pre-processed for modeling, and were given normal perfusion and Mailuoning perfusion for 1 h to restore their blood supply. After the recovery of blood supply for 4 h, the skeletal muscle morphology was detected by hematoxylin-eosin （HE） staining. The ultrastructure of the skeletal muscle was observed under transmission electron microscope. The serum levels of interleukin-1β （IL-1β） and tumor necrosis factor-α （TNF-α） were measured by ELISA. The mRNA levels of vascular endothelial growth factor （VEGF） and matrix metalloproteinase-2 （MMP-2） were detected by RT-qPCR, and the protein levels of β-catenin, Delta-like ligand 4 （Dll4） and Notch in skeletal muscular tissue were observed by Western blot. RESULTS The HE results of model group showed disordered arrangement of skeletal muscle fibers, swollen or obviously constricted nucleus, shrunken sarcolemma, ruptured and swollen blood vessels, edematous interstitium, obvious infiltrating inflammatory cells. The results of electron microscopy in model group showed disorderly arranged and dissolved myofilaments, partial loss of I-band, A-line and Z-line muscle fibers, obviously swollen endoplasmic reticulum, mitochondria and nuclei, and a large number of aggregated and internally shifted nuclei. The above indexes in normal perfusion group were slightly lighter than those in model group. In Mailuoning perfusion group, the results of HE staining observation showed almost normal skeletal muscle, neatly arranged muscle fibers, almost invisible shrinkage or swelling muscle membrane, and basically returned to normal blood vessels; the results of electron microscopy showed clearly visible and regular muscle fiber I-band, A-line, Z-line and neatly arranged nuclei. Compared with normal control group, the proportion of tissue swelling and vascular damage, the percentage of abnormal Z-line, the serum levels of IL-1β and TNF-α, the mRNA expression of VEGF and MMP-2, the protein levels of nucleoprotein/total β-catenin, Dll4 and Notch in skeletal muscular tissue in model group were increased （P<0.05）. Compared with model group, the proportion of tissue swelling and vascular damage, the percentage of abnormal Z-line, the serum levels of IL-1β and TNF-α, the mRNA expression of MMP-2, the protein levels of nuclear/total β-catenin, Dll4 and Notch in skeletal muscular tissue in normal perfusion group, and the serum levels of IL-1β and TNF-α, the mRNA expression of VEGF and MMP-2, the protein levels of nuclear/total β-catenin, Dll4 and Notch in skeletal muscular tissue in Mailuoning perfusion group were decreased （P<0.05）. Compared with normal perfusion group, the proportion of tissue swelling and vascular damage, the percentage of abnormal Z-line, the serum levels of TNF-α, the mRNA expression of MMP-2, the protein levels of nuclear/total β-catenin, Dll4 and Notch in skeletal muscular tissue in Mailuoning perfusion group were decreased （P<0.05）. CONCLUSION Mailuoning local perfusion suppresses Wnt/β-catenin and Notch signaling pathways, attenuates inflammation and vascular damage, thus realizing the protection of crush injury syndrome.     

Effects of rhTGF-β1 and TGF-β1 gene transfection on the proliferation of cultured rabbit corneal endothelial cells in vitro

AIM: To investigate the effects of rhTGF-β₁ and TGF-β₁ gene transfection on the proliferation of cultured rabbit corneal endothelial cells in vitro. METHODS: Cell growth induced by various concentrations of rhTGF-β₁ was determined by MTT proliferation assay. Under the induction of liposomes, recombinant pSecTag2-TGF-β₁MP vectors were transferred into the corneal endothelial cells. Morphological changes of transfected cells were observed by HE staining. The expression levels of TGF-β₁ were assessed by ELISA. Cell cycle analysis was assessed by flow cytometry. DNA fragment analysis was used to confirm the presence of apoptosis. RESULTS: rhTGF-β₁ in concentrations of 5-20 μg/L showed a significant suppressive effect on the proliferation of corneal endothelial cells, 0.5-1 μg/L had no effect, 0.05-0.1 μg/L facilitated cell growth, as compared with negative controls. The morphous of transfected corneal cells had no significant abnormality compared with normal cells. According to the result of ELISA, the concentration of TGF-β₁ in the supernatant was calculated to be (98±3) ng/L. Flow cytometry assay showed that S and G₂/M phase of transfected cells decreased significantly compared with that of control group, but the cell cycle recovered normally after adding 10 μg/L EGF into the culture medium. Agarose electrophoresis didn′t show marked ladders in transfected group. CONCLUSION: Effects of rhTGF-β₁ on the proliferation of corneal endothelial cells are different with various concentrations. TGF-β₁ gene transfection shows suppressive effect on the proliferation of cultured corneal endothelial cells, but does not induce cell apoptosis. EGF is the antagonist of this suppressive effect.     

Effects of rosiglitazone on expressions of peroxisome proliferator-activated receptor gamma and TGF-β1 in rats with adriamycin nephrosis

AIM: To investigate the expression of renal peroxisome proliferator-activated receptor gamma (PPARγ) in rats with adrimycine nephrosis (ADR), and the effect of rosiglitazone on the activation of NF-κB p65 in renal tissue rats with ADR. METHODS: The rats were randomly assigned to following groups: control (CTR) group, adrimycine nephrosis (ADR) group, and ADR treated with rosiglitazone (5 mg·kg^-1·d^-1) group（RGL）. The levels of urinary protein, albumin, total cholesterol, triglyceride and renal function change in rats were measured after 12 weeks. The nuclear-translocation of cortical NF-κB p65 was detected by immunohistochemistry. The activity of cortical NF-κB p65 was measured by sandwich ELISA. The mRNA levels of cortical PPARγ and TGF-β₁ were detected by RT-PCR. The protein expressions of PPARγ and TGF-β₁ in the rat kidney tissues were detected by Western blotting. RESULTS: As compared to ADR group, the urinary protein excretion in RGL treatment group was decreased and the serum albumin levels were increased, but the serum total cholesterol and triglyceride were decreased and the renal pathological lesion was ameliorated. The activity of NF-κB p65 and the expressions of TGF-β₁ mRNA and protein were significantly decreased in rosiglitazone group, while the expression of PPARγ mRNA and protein was increased in RGL group (P<0.01). The correlation analysis was manifested: in ADR and RGL group, a negative correlation between the activity of NF-κB p65 and the expression of PPARγ in renal tissue (r=-0.8305, P<0.01) was observed. There was a negative correlation between the expression of TGF-β₁ and PPARγ in renal tissues (r=－0.7938, P<0.01). CONCLUSION: The expression of renal cortical PPARγ is up-regulated in rats with adrimycine nephrosis by rosiglitazone. Rosiglitazone inhibits the activation of renal cortical NF-κB p65 in part, so it inhibits the gene expression of renal TGF-β₁ and relieves the renal pathological lesion.     

Effects of IOX1 on proliferation,apoptosis and extracellular matrix-related protein expression in LX2 cells induced by TGF-β

AIM To investigate the effects of histone demethylase inhibitor IOX1 (5-carboxy-8-hydroxyquinoline) on the proliferation, apoptosis and extracellular matrix (ECM)-related protein expression in transforming growth factor-β (TGF-β)-induced human hepatic stellate LX2 cells. METHODS The proliferation and apoptosis of the LX2 cells were determined by real-time cell analysis and flow cytometry, respectively. The level of histone H3 lysine 9 dimethylation (H3K9me2) and the protein expression of ECM-related molecules [α-smooth muscle actin (α-SMA), collagen type I (Col I), matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1)] in the LX2 cells were detected by Western blot. RESULTS Treatment with IOX1 at 50~300 μmol/L significantly inhibited LX2 cell proliferation, and 300 μmol/L IOX1 significantly promoted the apoptosis of the LX2 cells. In addition, different concentrations of IOX1 increased the levels of H3K9me2 and MMP-1, and down-regulated the expression of α-SMA, Col I and TIMP-1 in TGF-β-induced LX2 cells (P<0.05). CONCLUSION Treatment with IOX1 inhibits the proliferation of LX2 cells induced by TGF-β, promotes the cell apoptosis, and regulates the synthesis and metabolism of ECM by elevating H3K9me2 level, thus attenuating hepatic fibrosis.