Role of retinoic acid X receptor in regulation of autophagy in rat alveolar type Ⅱ epithelial cells induced by hypoxia/reoxygenation

AIM To investigate the regulatory effect of retinoic acid X receptor （RXR） on autophagy induced by hypoxia/reoxygenation （H/R） in rat alveolar type Ⅱ epithelial cells （AEC Ⅱ） and its molecular mechanism. METHODS AEC Ⅱ were cultured in normoxia. The cells growing to logarithmic growth phase were randomly divided into 5 groups： （1） control （Con） group： cells were cultured for 30 h under normal operation; （2） H/R group： cells were cultured in hypoxia condition for 6 h and then in reoxygenation condition for 24 h; （3） DMSO group： cells were pretreated 1.5 h with medium containing less than 0.1% DMSO before modeling, and the rest were treated the same as the H/R group; （4） 9-cis-retinoic acid （9-RA） group： cells were pretreated for 1 h with 9-RA （100 nmol/L） before hypoxia; （5） HX531 group： cells were treated with 9-RA （100 nmol/L） for 0.5 h, then treatment with HX531 （2.5 μmol/L） for 1 h. CCK-8 assay was used to detect the cell viability. Immunofluorescence staining was used to observe the expression of RXRα. Transmission electron microscope was used to observe the changes of intracellular ultrastructure, and the mRNA expression of adenosine AMP-activated protein kinase （AMPK）, beclin 1, LC3, mammalian target of rapamycin （mTOR） and P62 was detected by RT-PCR. Western blot was used to detected the protein levels of p-AMPK, beclin 1, LC3-Ⅱ, p-mTOR and P62. RESULTS Compared with Con group, the cell viability in H/R, DMSO, 9-RA and HX531 groups were significantly decreased. The mRNA expression of AMPK, beclin 1 and LC3 was significantly increased, and the protein levels of p-AMPK, beclin 1 and LC3-Ⅱ were also increased. The mRNA expression of mTOR and P62 was decreased, and the protein levels of p-mTOR and P62 were also decreased （P<0.05）. The cell injury in 9-RA group was alleviated and autophagy level was significantly lower than that in H/R, DMSO and HX531 groups （P<0.05）, and no significant difference among H/R, DMSO and HX531 groups was observed （P>0.05）. CONCLUSION H/R induces autophagy of AEC Ⅱ. Activating RXR reduce the damage of AEC Ⅱ cells induced by H/R, and its mechanism may be related to the inhibition of autophagy.     

Preventive effect of Sini decoction on expression of TGF-β1 in rat myocardiac fibrosis induced by isoproterenol

AIM: To explore the protective effects of Sini decoction (SD) on myocardial fibrosis induced by isoproterenol (Iso) in rats.METHODS: Nineteen Wistar rats were divided into Iso group, SD treatment group and control group. The rats in Iso group were injected with Iso and were then fed with saline. The rats in SD treatment group were injected with Iso and were then fed with SD. The rats in control group were injected with saline and were then fed with saline. The level of hydroxyproline (Hyp), the contents of angiotensin Ⅱ (AngⅡ) and transforming growth factor beta-1 (TGF-β1) in plasma were measured 4 weeks after administration. TGF-β1 at mRNA and protein levels were measured by the techniques of ELISA and RT-PCR. RESULTS: The plasma levels of TGF-β1 and AngⅡ were lower in control group than those in Iso group and SD treatment group (P<0.05). The plasma levels of TGF-β1 and AngⅡ in SD treatment group were lower than those in Iso group (P<0.05). Compared to Iso group, the cardiac diastolic function was significantly improved in SD treatment group (P<0.05). The results of immunohistochemistry and RT-PCR showed that the mRNA and protein expressions of TGF-β1 were lower in SD group than those in Iso group (P<0.05). CONCLUSION: SD alleviates myocardial fibrosis induced by Iso in rats by decreasing TGF-β1 expression at mRNA and protein levels.     

Protective effect and functional mechanism of curcumin on TNF-α induced neuronal damage in rat hippocampus

AIM: To observe the protective effect of curcumin on TNF-α induced neuronal damage in rat hippocampus and to explore the functional mechanism of curcumin. METHODS: The excitatory postsynaptic potential (EPSP) was recorded in CA1 pyramidal layer of rat hippocampal slices with in vitro brain slices recording techniques. High frequency stimulation was given on Schaffer branches to induce long-term potentiation (LTP). After treated with drugs, the initial slope of EPSP in each group was measured and calculated. RESULTS: Compared to control group, TNF-α and N-methyl-D-aspartate(NMDA) obviously inhibited the LTP in hippocampal slices of rat brain (P<0.05). Curcumin partly recovered the LTP, which was inhibited by TNF-α or NMDA, to near the control level (P>0.05). No effect of TNF-α, NMDA or curcumin on basal synaptic transmission in hippocampal slices was observed. CONCLUSION: Curcumin has protective effect on hippocampal neurons of rats. Curcumin can partly prevent the over-activation of NMDA receptor on neuronic membrane induced by TNF-α and maintain the long-term potentiation in neurons.     

Effect of S-nitrosylation induced by IL-1β and IFN-γ on DNA binding activity of cAMP response element binding protein in fibroblast-like synoviocytes

AIM: To investigate the effect of S-nitrosylation induced by recombinant interleukin-1β (rIL-1β) and recombinant interferon-γ (rIFN- γ) on DNA binding activity of cAMP response element binding protein (CREB) in fibroblast-like synoviocytes (FLSs). METHODS: (1)FLSs were incubated with rIL-1β and rIFN-γ in the presence or absence of inducible nitric oxide synthase inhibitor aminoguanidine (AG) for 12 h. The supernatant of the cell culture was collected to determine the contents of nitric oxide (NO). The total proteins prepared from each group ［only the total proteins prepared from rIL-1β+rIFN-γ group was reacted with dithiothreitol (DTT) for 15 min in vitro］ were subjected to the biotin switch assay, and the level of S-nitrosylation was determined by Western blotting. (2)FLSs were incubated with rIL-1β, rIL-1β+ rIFN-γ and AG respectively for 12 h. The nuclear extracts from each group were prepared. The nuclear extracts from each group were subjected to electrophoresis mobility shift assay to analyze the DNA binding activity of CREB (only the nuclear extracts from rIL-1β +rIFN-γ group was reacted with DTT for 15 min in vitro before assaying). RESULTS: rIL-1β plus rIFN-γ increased the production of NO and the level of S-nitrosylation, which was inhibited by AG. Administration of DTT in the total proteins reversed the induction of S-nitrosylation by rIL-1β and rIFN-γ. Co-incubation with rIL-1β and rIFN-γ inhibited the CREB activity induced by rIL-1β alone, which was reversed by AG. Administration of DTT in the nuclear extracts reversed the effect of co-incubation of the cytokines. CONCLUSION: Co-incubation with rIL-1β and rIFN-γ may increase the level of S-nitrosylation through inducing the production of endogenous NO, leading to reversible thiols modification of CREB and inhibit the DNA binding activity of CREB in FLSs.     

Effect of ERK1/2/c-Fos signal pathway on angiotensin-(1-7) inhibiting proliferation of rat glomerular mesangial cell strain induced by angiotensin Ⅱ

AIM: To investigate the effect of ERK1/2/c-Fos signal pathway during angiotensin-(1-7) inhibiting proliferation of rat glomerular mesangial cell strain (GMCS) induced by angiotensin Ⅱ. METHODS: Rat glomerular mesangial cells (GMC) were co-cultured with angiotensin Ⅱ and different doses of angiotensin-(1-7). The numbers of GMC were evaluated by crystal violet staining. The amounts of p-ERK1/2 and c-Fos expressions were detected by Western blotting. RESULTS: Angiotensin- (1-7) showed its inhibitory effects on GMC number increasing induced by angiotensin Ⅱ as well as the amounts of p-ERK1/2 and c-Fos expressions in a concentration dependent manner. CONCLUSION: ERK/c-Fos signal pathway is involved in the inhibitory effects of angiotensin-(1-7) on angiotensin Ⅱ -induced GMC proliferation.     

Role of IGF-Ⅱ in proliferation and migration of hepatocellular carcinoma Huh7 cells

AIM: To observe the effects of insulin-like growth factorⅡ (IGF-Ⅱ) at different expression levels on hepatocellular carcinoma Huh7 cell proliferation and migration, and to explore the role of IGF-Ⅱ in the development of HCC. METHODS: The Huh7 cells were transfected with the over-expression plasmid pcDNA3.1(+)- IGF-Ⅱ or RNA interference plasmid pLVX-shRNA-IGF-Ⅱ by Lipofectamine 2000. The quantitative real-time PCR and Western blotting were used to verify the expression of IGF-II. The biological behaviors of the Huh7 cells were analyzed by CCK-8 assay, plate clone formation assay, cell scratch test and Transwell chamber experiment.RESULTS: Over-expression of IGF-II promoted the growth and migration of hepatocellular carcinoma cells (P < 0.05), and the cell proliferation was significantly inhibited in the Huh7 cells with low IGF-II expression (P < 0.05).CONCLUSION: IGF-II is involved in the regulation of biological behavior of hepatocellular carcinoma Huh7 cells in vitro, which may play a promoting role in the development of hepatocellular carcinoma.     

Effects of thrombospondin 1 on rat cardiac fibroblasts induced by transforming growth factor β1

AIM:To investigate the effects of thrombospondin 1 on transforming growth factor β₁ induced rat cardiac fibroblasts (CFs). METHODS: CFs of neonatal Sprague -Dawley (SD) rats were isolated with the method of digestion and differential anchoring velocity. The proliferation and collagen synthesis of rat CFs were observed with MTT and hydroxyproline. The expression of TSP-1mRNA was analyzed by RT-PCR.RESULTS: The dose and time-dependent effects of TGF-β₁ were observed. Expression of TSP-1 was increased significantly (P<0.01). Stimulation of CFs with TGF-β₁ (20 μg/L, 24 h) significantly increased CFs proliferation and collagen synthesis (P<0.01). TSP-1 antisense oligonucleotide effectively inhibited TGF-β₁ induced CFs proliferation and collagen synthesis (P<0.01).CONCLUSION:The proliferation and collagen synthesis of CFs induced by TGF-β₁ are inhibited by TSP-1 antisense oligonucleotide, which may exert helpful effect on anti-fibrosis.     

Role of TGF-β1/Smads and ERK expression in vascular remodeling induced by high-salt diet in Wistar rats

AIM: To investigate the role of transforming growth factor β₁ (TGF-β₁)/Smads and extracellular signal-regulated kinase(ERK) expression in vascular remodeling induced by high-salt diet in Wistar rats. METHODS: Wistar rats were randomly divided into 3 groups: normal control group (n=13), high salt (8%) model group and high salt+telmisartan group (n=13). Tail-cuff arterial pressure was determined every 2 weeks. After 24 weeks, the rats in high salt model group were divided into model animals with hypertension group (MH, n=12) and model animals without hypertension group (MN, n=12). The remodeling of aorta and mesenteric artery was observed by HE and Masson staining. In addition, the techniques of immunohistochemistry and real-time PCR were applied to detect the expression of proliferating cell nuclear antigen (PCNA), TGF-β₁, p-Smad2/3, p-ERK1/2 and Smad7 at both protein and mRNA levels. RESULTS: Compared with normal control group, blood pressure in MH group was much higher, and media thickness (MT) and collagen volume fraction (CVF) of arteries in MH and MN groups were higher.The mRNA expression of TGF-β₁, Smad2 and Smad7 in the aorta was significantly increased, and the protein levels of PCNA, p-ERK1/2, TGF-β₁ and p-Smad2/3 in the aorta and mesenteric artery media were elevated, but Smad7 decreased. After telmisartan treatment, MT and CVF were much lower,and the protein levels of PCNA, TGF-β₁, p-Smad2/3 and p-ERK1/2 were significantly reduced, whereas Smad7 was increased. CONCLUSION: The abnormal expression of TGF-β₁/Smads and ERK may be involved in the mechanism of remodeling of aorta and mesenteric artery induced by high-salt diet. Telmisartan prevents the vascular remodeling via regulating TGF-β₁/Smads and ERK signal pathways mediated by angiotensinⅡ type 1 (AT₁) receptor, at least in part.     

Heme oxygenase decreases the generation of ROS in AngⅡ induced proliferation and hypertrophy of cultured vascular smooth muscle cells

AIM:To investigate the role of heme oxygenase (HO) in AngⅡ induced proliferation and hypertrophy of cultured vascular smooth muscle cells.METHODS:(1) Western blotting analysis was carried out to detect protein level of HO-1 in the tissues.(2) ［3H］-TdR, ［3H］-leucine incorporation was measured in cultured vascular smooth muscle cells.(3) 2,7-dichlorofluorescin diacetate (DCFH-DA) as an index was used to determine the cellular reactive oxygen species (ROS) level.RESULTS:(1) No significant difference in HO-1 protein expression level between AngⅡ-stimulated and control groups was observed, but HO-1 protein level in Hemin-induced group was higher than that in other two groups (P<0.01).No significant increase in HO-1 protein expression was found in zinc-protoporphyrin IX (ZnPPIX) group.(2) After AngⅡ stimulation, ［3H］-TdR and ［3H］-leucine incorporations of vascular smooth muscle cells (VSMCs) were increased.Hemin inhibited this increase.The higher concentration of Hemin, the more significant was the inhibitory effect.On the contrary, ZnPPIX promoted the increase in the effect of AngⅡ by inhibiting HO.(3) Fluorescence intensity in AngⅡ group was obviously higher than that in control groups (P<0.01).Compared with AngⅡ group, Hemin group decreased 62.7%, but ZnPPIX group increased 39.5%.CONCLUSION:Hemin induces HO-1 expression and inhibits the effect of AngⅡ to stimulate proliferation and hypertrophy of VSMCs.The mechanism may be related to its inhibition of ROS production.     

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.     

Role of PI3K/Akt signaling pathway in P12 cells apoptosis induced by β-amyloid peptide

AIM:To investigate the role of PI3K/Akt signaling pathway on cell apoptosis induced by β-amyloid peptide in PC12 cells. METHODS: The viability of PC12 cells and the levels of p-AktSer473 and p-GSK-3βSer9 were detected by MTT and Western blotting, respectively. Cell apoptosis was determined by Annexin V-PI staining. RESULTS: Aβ25-35 treatment decreased the viability of PC12 cells in a time-depended manner (P<0.05). Annexin V-PI staining demonstrated that Aβ25-35 induced PC12 cells apoptosis in a time-depended manner (P<0.05). Western blotting showed that Aβ25-35 induced an immediately decreased expression of p-AktSer473 and p-GSK-3βSer9 at 30 min (P<0.05), but increased at 3 h and decreased again at 6 h. However, after 12 h of peptide treatment, the p-GSK-3βSer9 increased while the p-AktSer473 remained decrease. CONCLUSION:PI3K/Akt signaling pathway is involved in cell apoptosis induced by β-amyloid peptide, which provides a new clue for the study of pathogenesis and management of AD.     

Stanozolol regulates the proliferation and differentiation of growth plate chondrocytes in the estrogen- inhibited adolescent rats through activation of ERα

AIM: (1) To observe the effect of stanozolol (ST) on the proliferation, maturity and differentiation of the growth plate chondrocytes cultured in vitro of adolescent rats treated with gonadotropin releasing hormone analogue (GnRHa). (2) To study if ST mediates the proliferation/differentiation of chondrocytes via the estrogen receptor α (ERα), and to investigate the mechanism of the biological effects in ST promoting bone growth/maturity in molecular level. (3) To predict the interaction mode of ST with ERα through molecular dynamics simulation, and to investigate the similarities and differences of the interaction mode between ERα with ST and estradiol. METHODS: Immunohistochemical staining of PCNA and MTT were conducted. Prediction of the interaction mode of ST with ERα was through molecular dynamics simulation. RESULTS: (1) Duplex effects of ST in time- effect and dose-effect modes were observed, respectively. With the appropriate dose and period of treatment, the proliferation of the growth plate chondrocytes presented the best effect. (2) After ST action, the expression of p-ERα was up-regulated with the increase in time, and up to the peak value at 10 min, then gradual down-regulation. With increase in ST concentration, the expression of p-ERα became gradually strong, and up to the peak value at 10-9 mol/L-10-8mol/L, then gradually weakened. After ERα and MAPKK were blocked, the expression of p-ERα induced by ST was weakened. (3)Like 17 β-estradiol, ST induced a stronger reaction of the hydrogen bonding with the two amino acids residues (Glu353, His524) of ERα. The bonding capacity of ST to ERα was almost the same as 17 β-estradiol. CONCLUSION: ST is a derivative of androgen, but the results of this study show that its action is ERα-mediated, including the classic ERα receptor pathway and MAPK pathway, resulting in the promoting growth and maturation of the long bone growth plate chondrocytes. Molecular dynamics study confirms that the ST can specifically and stably bind to ERα.     

Lysophosphatidic acid (LPA) induces the proliferation of astrocytes in rat via pathway of protein kinase C-α and calcium ion in vitro

AIM: To determine if lysophosphatidic acid (LPA) regulates the proliferation of astrocytes (AS) and to approach the mechanism of the process.METHODS: The cerebral AS of the neonatal SD rats were cultured in vitro and divided randomly into control group, PKC excitomotor (PMA) group, LPA group, PKC-α inhibitor (Ro31-8220) group, Ro31-8220+PMA group and Ro31-8220+LPA group. The proliferation of the cells was detected by MTT assay and flow cytometry (FCM). The concentration of intra-cellular calcium ion of the cells (［Ca2＋］i) which were labeled with Fura-2/AM was determined by ultraviolet spectrophotometer. The change of PKC-α inside the cells was observed by Western blotting.RESULTS: LPA and PMA stimulated the proliferation of AS, they also enhanced the expression of PKC-α and increased the concentration of ［Ca2＋］i. After pretreated with Ro31-8220, the abilities of LPA that mentioned above were decreased. The change of ［Ca2＋］i was associated with the diversity of PKC-α.CONCLUSION: LPA promotes the proliferation of AS via the way of PKC-α and Ca2＋.     

Protective role and mechanism of peroxysome proliferator activated receptor-γ in injury of cultured rat cortical neurons induced by hypoxia/ reoxygenation

AIM: To observe the role of peroxysome proliferator activated receptor-γ (PPAR-γ) and the relationship of cyclooxygenase-2 (COX-2) and PPAR-γ in injury of cultured rat cortical neurons induced by hypoxia/reoxygenation. METHODS: Primary rat cortical neurons were cultured. Experiments include control group, hypoxia/ reoxygenation group and hypoxia/ reoxygenation with PPAR-γ agonist group. Cell viability was surveyed by MTT assay. COX-2 protein expression was measured by Western blotting.RESULTS: Neuron viability raised dramatically in hypoxia/reoxygenation with PPAR-γ agonist group, compared with hypoxia/reoxygenation group (P<0.05). The COX-2 protein expression in hypoxia/ reoxygenation with PPAR-γ agonist group decreased significantly compared with hypoxia/ reoxygenation group (P<0.05). CONCLUSION: PPAR-γ agonist inhibits the expression of COX-2 and reduces obviously cortical neuron injury induced by hypoxia/ reoxygenation. It may protect cortical neurons by down-regulating the expression of COX-2.     

Adiponectin inhibits decrease in autophagy of rat H9c2 cardiomyocytes induced by β1-adrenergic receptor autoantibodies

AIMTo investigate whether adiponectin inhibits the decrease in autophagy of rat H9c2 cardiomy?ocytes induced by β₁-adrenergic receptor (β₁-AR) autoantibodies (β₁-AA), and to explore its mechanism. METH?ODS: SD rats were actively immunized with β₁-AR extracellular second loop (β₁-AR-ECII) antigen peptide. Affinity chromatography was used to purify β₁-AA in serum of the SD rats. The viability of H9c2 cells was measured by CCK-8 assay. The mRNA levels of LC3B and beclin-1 in the H9c2 cells were detected by real-time PCR. The protein levels of LC3-II, P62, AMP-activated protein kinase (AMPK) and phosphorylated AMPK (p-AMPK) were determined by Western blot. RESULTSPretreatment with adiponectin at 10 μg/L for 1 h reversed the decreased viability of H9c2 cells induced by β₁-AA. Compared with control group, β₁-AA decreased the mRNA expression of LC3B and beclin-1, decreased the protein level of LC3-II, and increased the expression of P62 protein in the H9c2 cells, suggesting that β₁-AA decreased the autophagic flux in cardiomyocytes. Adiponectin obviously reversed β₁-AA-induced decline in autophagic flux, and up-regulated the phosphorylation level of AMPK decreased by β₁-AA. Treatment with AMPK inhibitor Compound C for 30 min, we observed that the mRNA expression of LC3B and beclin-1 and the protein level of LC3-II in the H9c2 cells decreased by β₁-AA were not effectively reversed by adiponectin, but the increase in P62 protein expression was still effectively reversed, indicating that adiponectin increased autophagosome production dependent on the AMPK pathway, but increased autophagosome clearance independent on the AMPK pathway. CONCLUSION Adiponectin inhibits the decreased autophagy of H9c2 cardiomyocytes induced by β₁-AA.     

Effects of curcumin on actinomycin D/TNF-α-induced injury in PC12 cells and rat hippocampal neurons

AIM: To study the possible mechanism of curcumin on actinomycin D (ActD)/tumor necrosis factor α (TNF-α)-induced injury in PC12 cells and rat hippocampal neurons. METHODS: PC12 cells were divided into control group, TNF-α group, ActD group, curcumin group, ActD/TNF-α group and curcumin+ActD/TNF-α group. The cells were cultured for 24 h. Inverted fluorescence microscopy was used to observe the morphological changes of the cells in each group. Annexin V/PI double staining was applied to analyze the apoptosis of PC12 cells. The level of intracellular Ca²⁺ was detected by Fluo-3 AM staining. Rat hippocampal slices were prepared and divided into the same groups as the PC12 cells. Extracellular microelectrode recording technique was used to observe and calculate the changes of long-term potentiation (LTP) in different groups. RESULTS: Apoptosis of PC12 cells was induced by ActD/TNF-α. Curcumin protected the PC12 cells from ActD/TNF-α-induced apoptosis (P<0.05). ActD/TNF-α increased the intracellular Ca²⁺ concentration. Curcumin significantly reduced ActD/TNF-α-induced apoptosis by decreasing the intracellular Ca²⁺ concentration (P<0.05), inversed the effect of ActD/TNF-α on LTP in hippocampal slices, and improved the synaptic plasticity (P<0.05). CONCLUSION: Curcumin protects ActD/TNF-α-induced neuronal damage by depressing the intracellular Ca²⁺ concentration and maintaining the homostasis of intracellular calcium.     

Role of vascular remodeling for urotensin Ⅱ in rat thoracic aorta after balloon injury

AIM: To explore the possible effect of UII in the process of remodeling after vascular injury. METHODS: The rat model of balloon injury in thoracic aorta was established. Male rats were randomized to 4 groups (n=5), including sham injury group, injury group, UII group (UII pumped into the rats after thoracic aorta balloon injury at 1.0 nmol·kg-1·h-1) and urantide group (urantide pumped into the rats after thoracic aorta balloon injury at 10 nmol·kg-1·h-1). At 21 days, the thoracic aortas were taken out to measure the changes of pathology, the expression of UII, the proliferation of VSMC and the expression of collagen. RESULTS: (1) At the 21 days after operations, the systolic blood pressure was higher in UII group than that in injury group ［(140.0±10.0) mmHg vs (132.0±3.4) mmHg, P>0.05］. The systolic blood pressure was also obviously higher than that in urantide group ［(140±10.0) mmHg vs (128.0±2.4) mmHg, P<0.05］. (2) Urotensin Ⅱ was expressed strongly in the injured area after thoracic aorta injury. (3) In contrast to injury group, the intimal thicken in urotensin Ⅱ group enhanced, the decrease in lumen area was marked (0.13±0.05 vs 0.07±0.02, P<0.05), the cell proliferation index was markedly increased (0.74±0.16 vs 0.40±0.11, P<0.01), and the expression of collagen was also markedly increased (counted as IOD, 318±127 vs 78±26, P<0.01). (4) In contrast to injury group, the decrease in lumen area was not abolished (0.09±0.03 vs 0.07±0.02, P>0.05) after chronic infusion of urotensin Ⅱ receptor antagonist urantide, the cell proliferation index was markedly increased (0.73±0.15 vs 0.40±0.11, P<0.01) and the expression of collagen was not statistically increased (counted as IOD, 200±79 vs 78±26, P>0.05). CONCLUSION: Urotensin Ⅱ expresses strongly in the myointimal cells after thoracic aorta injury in rat. The extra UII enhances the proliferation of VSMC and expression of collagen in the myointimal, increases the stenosis of injured vasculature, indicating that UII might take part in the process of repairing after vessel injury.     

Effects of TNF-α-induced changes of expression and activity of 11-β HSD-1 on the insulin sensitivity in 3T3-L1 adipocytes

AIM: To observe the effects of tumor necrosis factor-α（TNF-α）-induced changes of expression and activity of 11-beta-hydroxysteroid dehydrogenase type1(11-β HSD-1) on the insulin sensitivity in 3T3-L1 adipocytes.METHODS: 3T3-L1 adipocytes were treated with TNF-α and TNF-α combined with aspirin, 2’-hydroxyflavanone or RU486, then mRNA expression and activity of 11-β HSD-1 and insulin-stimulated glucose uptake were examined.RESULTS: TNF-α increased expression and activity of 11-β HSD-1 in 3T3-L1 adipocytes, and decreased insulin-stimulated glucose uptake. Aspirin decreased expression and activity of 11-β HSD-1 induced by TNF-α, and alleviated the inhibiting effect of TNF-α on insulin-stimulated glucose uptake. 11-β HSD-1 specific inhibitor 2’-hydroxyflavanone and cortisol-receptor antagonist RU486 also alleviated the inhibiting effect of TNF-α on insulin-stimulated glucose uptake. CONCLUSION: TNF-α may decrease the insulin sensitivity in 3T3-L1 adipocytes through increasing expression and activity of 11-β HSD-1.