Effect of glucocorticoid-treated dendritic cells on asthmatic Th2 response

AIM: To investigate the effect of dexamethasone-treated dendritic cells (DCs) on Th2 cytokine production from autologous T cells in asthmatic patients and explore the mechanisms by studying the effect of dexamethasone on differentiation, maturation and function of DCs from patients with asthma. METHODS: Human peripheral blood monocyte-derived DCs generated from asthmatic patients and healthy subjects were cultured in the absence or presence of dexamethasone. The phenotypic characterization of DCs was analyzed by flow cytometry. The mature DCs were harvested, washed, and then cocultured in vitro with autologous T cells purified by a nylon cotton column. The DC-T coculture supernatants were collected after 72 h incubation and analyzed for levels of IL-5 and IFN-γ by ELISA. RESULTS: The concentrations of IL-5 in the culture supernatants of DC-T coculture were significantly up-regulated in patients with asthma compared with that in healthy controls ［(145.13±89.76) ng/L vs (50.28±22.37) ng/L, P<0.01］. The level of IFN-γ in the DC-T coculture supernatants tended to be decreased in asthmatic patients than that in healthy controls, although this difference did not achieve statistical significance ［(197.58±76.32) ng/L vs (220.46±65.34) ng/L, P>0.05)］. There were significantly decreased levels of IL-5 by autologous T cells primed by dexamethasone-treated mature DCs from asthmatic patients ［(45.39±19.61) ng/L vs (145.13±89.76) ng/L, P<0.01］, alterations not observed from healthy controls (P>0.05). IFN-γ production was decreased by autologous T cells primed by dexamethasone-treated mature DCs from both asthmatic patients and healthy controls ［asthma group: (40.21±22.89) ng/L vs (197.58±76.32) ng/L, P<0.01; healthy controls: (56.78±20.37) ng/L vs (220.46±65.34) ng/L, P<0.01］. Dexamethasone-treated DCs exhibited decreased expression of CD83 (P<0.01) and increased expression of CD14 (P<0.01) in both asthmatic patients and healthy controls. CONCLUSION: DCs of asthmatic patients induce a Th2-skewed cytokine production from autologous T cells. Dexamethasone-treated DCs inhibit the Th2 reactions, and this effect is probably mediated through the pathway that dexamethasone inhibits DCs maturation and skews the macrophage/DC balance towards the macrophage side and thus directs the development more towards the macrophage lineage.     

Relationship between Th1/Th2 balance and CD28/CTLA-4 expression on peripheral blood T cells in patients with systemic lupus erythematosus

AIM: To investigate the pattern of Th1/Th2 balance in systemic lupus erythematosus(SLE) patients and the relationship between CD28/CTLA-4(cytotoxic T-lymphocyte antigen-4) molecule expression and Th1/Th2 balance.METHODS: Eighteen SLE patients met the ARA 1997 updated SLE criteria were selected in the study. According to Bombardier's SLEDAI criteria, all patients were classified into two groups: active group(12 cases) and static group(6 cases). Fourteen normal individuals, matched for age and sex of the patients, served as controls. The peripheral blood mononuclear cells(PBMCs) were isolated by density gradient centrifugation and cultured in RPMI-1640 culture medium. After treated with PMA(5 μg/L) and ionomycin(500 μg/L) for 72 h, the PBMCs were collected, the contents of IFN-γ and IL-10 in the supernatant of cultured PBMCs were detected using enzyme linked immunosorbent assay(ELISA). The expression of CD28 and CTLA-4 molecules on T cells were detected by flow cytometric technique with double staining by FITC or PE labeled monoclonal antibodies. RESULTS: The level of IL-10 was higher in the PBMCs of active and static SLE patients(351.29 ng/L±153.31 ng/L and 319.37 ng/L±153.39 ng/L) than that in controls(254.48 ng/L±120.69 ng/L), but the difference did not reach statistical significance(P>0.05). The level of IFN-γ was significantly lower in the PBMCs of active SLE patients(25.76 ng/L±16.09 ng/L) than that in controls(50.71 ng/L±27.92 ng/L, P＜0.05). The ratio of IL-10/IFN-γ was significantly higher in active SLE patients(18.74±13.77) than that in controls(6.66±4.95, P<0.05). Either before or after culture, the expression of CD28 molecule on CD3⁺and CD8⁺ T cells from all SLE patients was not remarkably different from that in the cells of controls. Before culture, the expression of CTLA-4 molecule on CD3⁺T cells of active SLE patients(0.79%+0.37%) was significantly lower than that in the cells of controls(1.31%+0.61%, P<0.05). After culture, the expression of CTLA-4 molecule on CD3⁺ T cells of SLE patients was still lower than that in the cells of normal controls without statistical significance(P＞0.05).The expression level of CD28 molecule on CD3⁺ or CD8⁺ T cells in active SLE patients and controls was not correlated with the levels of IFN-γ and IL-10 in the supernatants(P＞0.05). The level of CTLA-4 molecule expression on CD3⁺ T cells of active SLE patients was positively correlated with IFN-γ level(r=0.681, P<0.05), while was negatively correlated with IL-10 levels(r=-0.624,P＜0.05) and the ratio of IL-10/IFN-γ(r=-0.738, P<0.01). The level of CTLA-4 molecule expression on CD3⁺ or CD8⁺ T cells of controls showed no correlation with IFN-γ levels, while showed negative correlations with IL-10 level(r=-0.587, P<0.05; r=-0.563, P<0.05, respectively).CONCLUSION: There is a bias in the differentiation of Th0 cells towards Th2 in SLE patients. CTLA-4 probably plays an important role in this mechanism through suppressing the signal transmitted by CD28.     

Prolactin induces interleukin-6 expression in PBMCs of rheumatoid arthritis patients

ATM: To investigate the correlation between serum prolactin (PRL) levels and disease activity in rheumatoid arthritis (RA) patients, and the regulatory role of PRL in interleukin-6 (IL-6) release from peripheral blood mononuclear cells (PBMCs), and to explore the MAPK-related mechanism of IL-6 release in PBMCs. METHODS: The clinicopathologic and hematologic parameters of 40 new-onset RA patients in the Department of Rheumatology of our hospital between March and September 2015 were collected. Chemilumineseent immunoassay (CLIA) was used to detect the serum PRL levels in the 40 RA patients and 20 healthy controls. The levels of IL-6 secretion by the PBMCs were evaluated using ELISA. Quantitative real-time PCR was employed to examine the mRNA expression of prolactin receptor (PRLR). MAPK pathway protein p-p38 levels were evaluated by Western blot. RESULTS: Serum PRL level in the RA patients was significantly higher than that in the healthy controls (P<0.01). Serum PRL level in active RA patients was significantly higher than that in inactive RA patients (P<0.01). Serum PRL level was positively correlated with DAS28, ESR and CRP (P<0.01). The expression of PRLR in the PBMCs was markedly increased in the RA patients than that in the healthy samples (P<0.01). Exposure of the PBMCs to PRL in the culture increased the release of IL-6, which was abolished by PRLR gene silencing or blocking the MAPK pathway.CONCLUSION: Serum PRL level is related to DAS28, ESR and CRP of RA patients and could be used as a predictor of disease activity. PRL/PRLR-p38 MAPK-IL-6 pathway may play a central role in the pathogenesis of RA.     

Expression and significance of thrombospondin-1 in myocardium of type 2 diabetic cardiomyopathy rats

AIM: To investigate the expression and significance of thrombospondin-1 (TSP-1) in left ventricular myocardium of type 2 diabetic cardiomyopathy (DCM).METHODS: The rat model of DCM was established by eating a high-fat diet together with injection of low dose streptozocin (30 mg/kg) intrapertoneally.After 12 weeks,the content of collagen was quantified by Masson staining.The mRNA level of TSP-1 was determined by quantification real-time RT-PCR,while the protein level of TSP-1 was analyzed by Western blotting and immunohistochemistry.RESULTS: Compared with the control group,the content of collagen in the DCM group was increased greatly (11.01±3.05 vs 16.92±3.18,P<0.01).The mRNA and protein expressions of TSP-1 were significantly higher than those in control group (0.0089±0.0034 vs 0.0141±0.0037,P<0.05；96.38±16.80 vs 129.98±16.96,P<0.05).In DCM group,the mRNA and protein expressions of TSP-1 showed significantly positive correlations with the levels of fasting blood glucose and collagen (r=0.762,P<0.01; r=0.717,P<0.05; r=0.735,P<0.01; r=0.750,P<0.01).There was a significantly positive correlation of TSP-1 mRNA level with LVEDP (r=0.658,P<0.05).In contrast,there was a significantly negative correlation of TSP-1 protein with LVSP and -dp/dtmax (r=-0.605,P<0.05; r=-0.694,P<0.05).There was a significantly positive correlation of TSP-1 protein with LVEDP (r=0.716,P<0.05).There was a significantly negative correlation of TSP-1 protein with LVSP and -dp/dtmax (r=-0.633,P<0.05; r=-0.669,P<0.05).CONCLUSION: The increased expression of TSP-1 may play an important role in the development of myocardial interstitial fibrosis in DCM.     

Effect of pachyman polysaccharides on Th17/Treg balance in systemic lupus erythematosus patients

AIM: To investigate the immunomodulatory effect of pachyman polysaccharides (PPS) on T helper 17 cell (Th17)/regulatory T cell (Treg) balance in the peripheral blood of systemic lupus erythematosus (SLE) patients. METHODS: The CD4⁺ T cells were isolated from the peripheral blood samples obtained from 45 SLE patients and 35 healthy controls enrolled in our study using magnetic bead separation method. The proportions of Th17 and Treg cells were measured by flow cytometry. The CD4⁺ T cells from SLE patients and healthy controls were treated with PPS. The cytoto-xicity of PPS was evaluated by detecting cell viability with MTT assay. The contents of interleukin-17 (IL-17), IL-6, IL-10 and transforming growth factor-β (TGF-β) were measured by ELISA. The expression of retinoid-related orphan receptor γt (RORγt) and forkhead box protein P3 (Foxp3) at mRNA and protein levels was determined by RT-qPCR and Western blot, respectively. RESULTS: The Th17 cells were significantly elevated, while Treg cells were obviously decreased in the SLE patients compared with the healthy control group (P<0.05). Compare with control group, the contents of IL-17 and IL-6 were decreased, while the contents of IL-10 and TGF-β were increased (P<0.05). The expression of RORγt at mRNA and protein levels was down-regulated and the expression of Foxp3 was up-regulated (P<0.05). The ratio of Th17/Treg was decreased in 100 μg/L nontoxic PPS-treated CD4⁺ T cells isolated from the SLE patients (P<0.05). CONCLUSION: PPS treatment inhibits Th17 cells and elevates Treg cells in the CD4⁺ T cells isolated from SLE patients, which may have a therapeutic effect on SLE patients.     

Effect of rhSOD on pulmonary nuclear factor-kappa B and MIP-1α expression in meconium-induced acute lung injury

AIM: To evaluate the role and mechanisms of recombinant human superoxide dismutase (rhSOD) in meconium-induced acute lung injury (ALI) by evaluating pulmonary MIP-1α and NF-κB expression. METHODS: 24 health male Sprage-Dawley rats were randomized to 3 groups (8, each group), followed by intratracheal (IT) administration with (1) saline at 1 mL/kg (control group); (2) 20% human newborn meconium suspension at 1 mL/kg, followed by saline at 1 mL/kg (Mec/saline group); (3) 20% human newborn meconium suspension at 1mL/kg, followed by rhSOD at 20 mg/kg (Mec/rhSOD group). The animal was killed 24 h after treatment. The measurements included the bronchoalveolar lavage (BAL) cell count, RT-PCR analysis of pulmonary MIP-1α mRNA expression, Western blotting analysis of pulmonary NF-κB expression. RESULTS: Meconium-induced ALI was characterized by increased BAL cell count, increased expressions of pulmonary MIP-1α mRNA and NF-κB protein ［(4.68±1.40)×109 cells/L vs (0.53±0.19)×109 cells/L, 3.60±0.75 vs 1.56±0.33, 0.72±0.31 vs 0.23±0.12, respectively in control rats, all P<0.01］. IT administration of rhSOD early in the ALI rat significantly decreased meconium-induced BAL cell count ［(3.13±0.77)×109 cells/L vs (4.68±1.40)×109 cells/L in Mec/saline rats, P<0.01］, inhibited the expression of pulmonary MIP-1α mRNA (2.20±0.39 vs 3.60±0.75, in Mec/saline rats, P<0.01) and NF-κB protein (0.44±0.21 vs 0.72±0.31 in Mec/saline rats, P<0.05). CONCLUSION: The early IT administration of rhSOD in ALI rat following meconium aspiration protects lung from inflammatory injury through inhibiting meconium-induced pulmonary MIP-1α mRNA and NF-κB protein expression.     

Premature response to luteinizing hormone of granulosa cells from women with polycystic ovary syndrome

AIM:To demonstrate the relationship between hormones in follicular fluid and the expression of LH receptor in granulosa cells (GC) in anovulatory women with polycystic ovary syndrome (PCOS). METHODS:Follicles were obtained from 12 women with PCOS and 15 women with normal menstrual period through surgery at time between day 7 and day 10 of menstrual cycle. The accumulations of estrogen (E2), progesterone (P), luteinizing hormone (LH), follicle stimulating hormone (FSH) and insulin in follicular fluid were determined by a automatism chemiluminescent microparticle immunoassay (CMIA) for the quantitative determination. The accumulation of androstenediol (A) was determined by ELISA. The amounts of the mRNA expressions of LH receptors from GC and theca cells (TC) respectively were measured by RT-PCR using β-actin as intra-control simultaneously. RESULTS:The levels of LH ［(3.8±2.1 vs 1.7±0.8)IU/L, P<0.01］, A ［(600.0±373.4 vs 212.4±205.4)μg/L, P<0.05］ and expressions of LH receptor mRNA of GC (0.29±0.16 vs 0.12±0.13, P<0.01) and TC (0.46±0.14 vs 0.34±0.09，P<0.05) in the women of PCOS group were statically higher than those in control group. The expression of LH receptor mRNA was not detected by RT-PCR in control group when the diameter of an follicle was less than 7 mm, while it was detected in women with PCOS when it remained as small as 4 mm. Expression of LH receptor mRNA in granulose cells was positive related to the concentration of LH (r=0.67, P<0.01) and insulin (r=0.51, P<0.05) in follicular fluid, and that in theca cells (r=0.60, P<0.01). CONCLUSION:The high level of LH in follicular fluid occurs and GC responds to LH prematurely and more intensively in anovulatory women with PCOS. Larger amount of A and P was produced as a result. All of above may contribute to the mechanism of anovulatory.     

Clinical significance of elevated serum interleukin 15 in patients with active lupus nephritis

AIM: To detect interleukin 15 (IL-15) levels in peripheral blood from patients with active lupus nephritis and investigate its clinical significance. METHODS: IL-15 level was determined by enzyme linked immunosorbent assay (ELISA). The peripheral blood mononuclear cells (PBMCs) were isolated with grads density abaxiality. The inhibitory effects of dexamethasone on production of IL-15, IgG and anti-dsDNA antibody in cultured PBMCs from LN patients were also investigated. RESULTS: (1) Serum IL-15 level in LN patients was significantly higher than that in normal controls (P<0.01). Serum IL-15 level in active LN patients was significantly higher than that in remised patients (P<0.05). (2) Serum IL-15 level was positively correlated with SLEDAI, anti-dsDNA antibody and 24 h urine protein excretion in active LN patients. (3) Serum IL-15 level was significantly reduced in LN patients treated with combination of cyclophosphamide (CTX) and steroid for 12 weeks. (4) Secretion of IL-15, IgG and dsDNA antibody in cultured PBMCs from active LN patients was significantly higher than that in normal control group, and IL-15 level in supernatant of cultured PBMCs from active LN patients was positively correlated with IgG and dsDNA antibody. Dexamethasone inhibited the secretion of IL-15, IgG and dsDNA antibody in cultured PBMCs from LN patients. CONCLUSION: Serum IL-15 level in patients with active lupus nephritis is significantly elevated, suggesting that IL-15 may be involved in the pathophysiological process of LN. IL-15 may be used as an index to assess the activity of LN.     

Abnormal T-cell receptor signal pathway in murine autoimmue cardiom yophy induced with adenine nucleotide translocase

AIM: To explore the molecular mechanism in the pathogenesis of dilated cardiomyopathy (DCM) by analyzing the expression of T cell signaling molecules in mice with autoimmune DCM. METHODS: Mouse DCM model was induced by immunizing the animals with adenine nucleotide translocase (ANT) synthetic peptides. P56lck in T cells was detected with real-time fluorescent quantitative PCR in both DCM-group and the sham-immunized controls. At the same time, flow cytometry was used for quantity of Th cell intracellular cytokine IFN-γ and IL-4, ELISA for examining the level of serum anti-ANT antibody, immune histochemistry for investigating the expression of CD45 in Th cells. RESULTS: The mRNA expression of P56lck (1 369.51±874.05 vs 47.93±10.21, P<0.01), the percentage of IFN-γ and IL-4 (especially IL-4) (8.27±1.29 vs 5.58±0.59, P<0.01; 9.93±1.53 vs 2.05±0.21, P<0.01), the level of anti-ANT autoantibody (0.105±0.015 vs 0.006±0.002, P<0.01) and expression of CD45 (0.154±0.021 vs 0.026±0.008, P<0.01) were all elevated significantly in DCM-group compared with the controls. CONCLUSION: Impairment of T cell receptor (TCR) signal transduction pathway plays an important role in the development of DCM induced with ANT synthetic peptides in mice.     

Effect of mycophenolic acid on T lymphocyte proliferation and cytokine expression in vitro

AIM: To investigate the effect of mycophenolic acid (MPA) alone or in combination with anti B7-1 mAb on proliferation of T lymphocytes and the possible mechanisms. METHODS: The proliferation of T lymphocytes was detected by BrdU incorporation method. The expressions of IL-2, IFN-γ and IL-10 in mRNA and protein levels were detected by RT-PCR and ELISA, respectively. RESULTS: (1) MPA markedly inhibited the T lymphocyte proliferation as compared with control (P<0.01). (2) MPA significantly inhibited the levels of IL-2 and IFN-γ (42.73 ng/L±14.64 ng/L vs 99.70 ng/L±9.15 ng/L, P<0.01; 7.87 ng/L±4.22 ng/L vs 82.42 ng/L±25.55 ng/L, P<0.05), and significantly increased content of IL-10 compared with control (770.95 ng/L±126.85 ng/L vs 545.71 ng/L±22.45 ng/L, P<0.05). MPA in combination with anti B7-1 mAb obviously enhanced the content of IL-10 compared with MPA alone (941.90 ng/L±56.61 ng/L vs 770.95 ng/L±126.85 ng/L, P<0.05). (3) The expression levels of IL-2 and IFN-γ mRNA in the MPA group were obviously lower than those in control (0.74±0.10 vs 1.17±0.15, 0.52±0.05 vs 0.75±0.12, P<0.01). MPA in combination with anti-B7-1 mAb showed a statistically significant increase in IL-10 mRNA expression (1.28±0.06 vs 0.84±0.09, P<0.01) as compared with MPA alone. CONCLUSION: MPA induces the changes of cytokine expressive spectrum and the Th1 and Th2 shift might be involved in the immunosuppressive effect. The combination of MPA with anti B7-1 mAb might have a synergic effect.     

Expression of A20 in patients with systemic lupus erythematosus

AIM: To investigate the expression and regulation of A20 in healthy individuals and the patients with systemic lupus erythematosus (SLE). METHODS: The expression levels of A20, NF-κB, MALT1, and MALT1V1 in peripheral blood mononuclear cells (PBMC) of the patients with SLE (including 2 cases with scleroderma, 1 case with rheumatoid arthritis, and 1 case with lymphoma) were analyzed by real-time PCR. RESULTS: A significantly lower A20 expression level was found in the PBMC from SLE group compared with the healthy controls, while the expression levels of MALT1 and NF-κB were also decreased. In addition, no significant correlation between A20 and NF-κB expression levels in healthy group was observed, but a positive correlation was found in SLE group (P<0.05). A significant positive correlation between MALT1 and NF-κB expression levels in healthy group (P<0.05) was observed, and no significant correlation was found in SLE group. The expression level of MALT1V1 in SLE group was significantly lower than that in healthy control group, and there was a positive correlation between A20 and MALT1V1 in healthy volunteers (P<0.01), but that did not exist in SLE group. CONCLUSION: The characteristics of the expression pattern of MALT1-A20-NF-κB in the SLE patients were presented. Lower level of A20 expression was found in the SLE patients, in particular with other autoimmune disease or lymphomas, indicating the lower immune tolerance in SLE. The positive correlation of A20 and NF-κB may relate to positive regulation of MALT1.     

Increased expression of CD40 ligand by peripheral blood mononuclear cells in patients with systemic lupus erythematosus

AIM:To investigate expression and function of CD40 ligand by peripheral blood mononuclear cells (PBMCs) in patients with systemic lupus erythematosus (SLE).METHODS:Expression of CD40 ligand by PBMCs in patients with SLE and control were examined by flow cytometric analysis before and after stimulated by phytohemagglutinin(PHA)and depressed by Dexamethasone(Dex). The correlation between expression of CD40 ligand and SLE activity index(SLEDAI) was analysed in patients with SLE.RESULTS:The expression of CD40 ligand by PBMCs in patients with active SLE was higher than that in patients with inactive SLE and control. Though the expression of CD40 ligang by PBMCs could be stimulated by PHA in three groups, it was the highest in patients with active SLE. Dex depressed the expression of CD40 ligand by PBMCs significantly in patients with SLE, but not in control. There was high positive correlation between expression of CD40 ligand and SLEDAI in patients with active and inactive SLE.CONCLUSION:Increased expression of CD40L by PBMCs in patients with SLE may play an important role in pathogenesis of SLE.     

Effect of FAK-related non-kinase on apoptosis in hepatic stellate cells

AIM: To evaluate the inhibitory effect of FRNK on the phosphorylation of FAK and apoptosis in hepatic stellate cells (HSCs). METHODS: After stimulated with fibronectin, HSCs was transfected with FRNK plasmid by cationic liposome method. The apoptosis of FRNK-induced HSCs was examined by Annexin-V/propidium iodide double-labeled flow cytometry (FCM), gel electrophoresis and transmission electron microscope. The protein levels of FRNK, FAK and p-FAK (Tyr397) in HSCs were assayed by Western blotting, and RT-PCR was used to detect the expression of mRNA. RESULTS: The expression of FRNK was enhanced and the phosphorylation of FAK was inhibited after FRNK was transiently transfected into HSCs in vitro. The apoptotic rate in HSCs exposed to FRNK plasmid for 48 h was higher than that in the non-FRNK plasmid group ［(25.37±1.92) % vs (9.28±1.05) %, P<0.01］, and accompanied by a significant increase in caspase-3 activity both in the protein and in the mRNA level ［(264.17±12.60 vs 185.82±9.69), P<0.01; (4.19±0.48 vs 1.07±0.27), P<0.01］. CONCLUSION: In HSCs, the expression of FRNK is enhanced and the phosphorylation of FAK is inhibited after FRNK transfection. FRNK induces the HSCs apoptosis.     

Effect of atorvastatin on blood pressure in spontaneously hypertensive rats

AIM: To explore the mechanisms underlying the effect of atorvastatin on blood pressure in spontaneously hypertensive rats (SHR). METHODS: The effects of atorvastatin on plasma endothelin-1, aortic nitric oxide synthase, aortic smooth muscle cell (ASMC) apoptosis and p27 expression in SHR were evaluated. 12 eight-week-old SHR were randomized into atorvastatin group (ATV, n=6) and SHR group (n=6). 6 age-matched normotensive Wistar-Kyoto rats (WKY) were served as controls. 50 mg·kg-1·d-1 of atorvastatin was administered to ATV by gavage for 10 weeks. Serum cholesterol and triglycerides were measured, and systolic blood pressure of caudal artery was examined. Plasma endothelin-1 and nitric oxide synthase activity of aortic tissue were measured. ASMC apoptosis rate was detected by TUNEL technique, and positive expression rate of P27 in ASMC was analyzed. RESULTS: After 10 weeks, systolic blood pressure in ATV was significantly lower than that in SHR ［(134.17±3.60）mmHg vs （173.33±3.78）mmHg, P<0.01］. Compared with SHR, serum cholesterol and triglycerides were significantly lower (P<0.01, P<0.01) in ATV. Additionally，atorvastatin significantly decreased plasma endothelin-1 ［(130.04±40.07）ng/L vs （196.74±59.69）ng/L, P<0.05］ and increased nitric oxide synthase activity in aortic tissue ［(0.189±0.040）kU/g protein vs (0.124±0.057)kU/g protein, P<0.01］, compared with SHR. ASMC apoptosis rate was higher in ATV than that in SHR (16.94%±3.08% vs 9.01%±2.36%, P<0.01). Compared with WKY, positive expression rate of p27 in ASMC from ATV was higher (33.02%±5.01% vs 24.25%±4.41%, P<0.05), whereas that was lower in SHR (16.08%±7.09% vs 24.25%±4.41%, P<0.01). CONCLUSION: Atorvastatin may reduce the plasma endothelin-1， up-regulate nitric oxide synthase activity and ASMC P27 expression and facilitate ASMC apoptosis，which may effectively reduce blood pressure in SHR.     

Effects of histamine and hypoxia on eNOS gene expression in cultured porcine pulmonary and aorta endothelial cells

AIM: To investigate the effect of histamine and hypoxia on the expression of eNOS mRNA and protein in cultured porcine pulmonary artery and aorta endothelial cells. METHODS: Semi-quantitative RT-PCR and immuno-cytochemistry were used. RESULTS: (1) Histamine increased eNOS mRNA expression in a dose-and time dependent manner. For pulmonary endothelial cells, the effect reached peak when exposed to 10-5 mol/L histamine in 24 h. eNOS mRNA level was increased to 178.2%±7.7% (P<0.01) compared with control. eNOS protein was also enhanced to 173%±47% (P<0.01) compared with control. For aorta endothelial cells, the effect reach peak when exposed to 10-6 mol/L histamine in 24 h. The eNOS mRNA level was increased to 177.4%±14.3% (P<0.01) compared with control. The eNOS protein was also enhanced to 165%±54% (P<0.01). (2) The eNOS mRNA was enhanced in pulmonary endothelial cells after exposed to hypoxia for 12 h and reached peak in 24 h, increasing to 151.0%±9.1% (P<0.01). The protein expression was also enhanced to 216%±44% (P<0.01) compared with control. But there was no significant change in eNOS mRNA and protein expression in aorta endothelial cells during hypoxia. CONCLUSION: The experiments show that histamine increases the endothelial eNOS expression in both pulmonary and aorta endothelial cells, whereas hypoxia only increases eNOS expression in pulmonary endothelial cells. This may account partly for the different responses of pulmonary circulation and systemic circulation to hypoxia.     

Correlation between intracellular magnesium and expression of beta 2-adrenergic receptor mRNA in the lung of C57BL/6 asthmatic mice

AIM: To explore the effect of intracellular magnesium on expression of beta 2-adrenergic receptor mRNA in the lung of C57BL/6 asthmatic mice. METHODS: Ninety-six healthy, 4-6 weeks old and female C57BL/6 mice, weighting (12±2) g, were randomly divided into the following A, B, C, D groups with 24 mice in each group. The mice were sensitized and challenged by ovalbumin to establish the asthmatic model. A and B groups were fed with magnesium deficient diet. C and D groups were fed with normal magnesium level diet. B and D groups were injected intraperitoneally with 0.2 mL sulphate salbutamol solution after OVA provocation. A and C groups were injected intraperitoneally with 0.2 mL saline as control. Eight mice in each group were randomly taken out at 1 d, 21 d, 34 d to detect plasma Mg2+, intracellular Mg2+, the beta 2-AR mRNA and protein in lung tissue. RESULTS: No significant difference in plasma Mg2+, intracellular Mg2+, the beta 2-AR mRNA and protein in lung tissue among all groups at 1st d was observed (P>0.05, respectively). Plasma Mg2+, intracellular Mg2+, the beta 2-AR mRNA and protein in lung tissue in group C at 21st d and 34th d were significantly higher than those in group A at 21st d and 34th d ［21st d:(0.84±0.09)mmol/L vs 0.57±0.10)mmol/L, (2.39±0.14)mmol/L vs (2.11±0.08) mmol/L,(0.75±0.09)pmol/g vs (0.59±0.06)pmol/g, (88.50±8.50)pmol/g vs (60.10±7.70)pmol/g, P<0.05, respectively; 34th d:(0.67±0.10)mmol/L vs (0.51±0.09)mmol/L, (2.17±0.08)mmol/L vs (2.05±0.09)mmol/L,(0.61±0.05)pmol/g vs (0.53±0.06)pmol/g, (76.60±7.10)pmol/g vs (58.00±7.60)pmol/g, P<0.05, respectively］. Also, plasma Mg2+, intracellular Mg2+, the beta 2-AR, mRNA and protein of lung tissue in group D at 21st d and 34th d were significantly higher than those in group B at 21st d and 34th d ［21st d:(0.95±0.33)mmol/L vs (0.46±0.09)mmol/L,(2.32±0.18)mmol/L vs (1.87±0.14)mmol/L,(0.73±0.10)pmol/g vs (0.43±0.07)pmol/g, (96.90±8.00)pmol/g vs (47.90±4.90)pmol/g, P<0.05, respectively; 34th d:(0.71±0.10)mmol/L vs (0.31±0.08)mmol/L, (1.66±0.13)mmol/L vs (1.45±0.16)mmol/L,(0.40±0.07)pmol/g vs (0.33±0.05)pmol/g, (61.50±3.20)pmol/g vs (35.30±7.10)pmol/g, P<0.05, respectively］.CONCLUSION: The expression of β2-adrenergic receptor mRNA in the lung of C57BL/6 asthmatic mice with deficient intracellular magnesium is suppressed and C57BL/6 asthmatic mice with deficient intracellular magnesium are even easier to induce downregulation of β2-adrenergic receptor when β2-AR agonist is administered.     

Effect of dexamethasone on the adrenomedullin and its gene expression in lung tissue of asthmatic rats

AIM: To study the effect of dexamethasone (DEX) on the adrenomedullin (ADM) and its gene expression in lung tissue of asthmatic rats. METHODS: 30 healthy male SD rats were randomly divided into three groups (10 for each). The asthmatic model was established by ovalbumin inhalation and injection. The mRNA expression of ADM was examined by RT-PCR and the protein expression was detected by immunohistochemical method. The airway wall thickness, the airway smooth muscle (ASM) thickness and pulmonary tissue changes were observed under light microscope. RESULTS: The expression of ADM mRNA and protein in the asthma group A were higher than those in the control group(group C) (P<0.05), indicating that the moderate expression of ADM in asthmatic rat lung tissue is compensatory. The expression was significantly higher in DEX group (group B) than that in group A (P<0.01), indicating that DEX stimulated the expression of ADM mRNA and protein in lung tissue of asthmatic rats. CONCLUSION: The remarkable expression of ADM after the therapy of dexamethasone is one of its therapeutic mechanisms.     

Effect of NAC on oxidant stress and apoptosis in the hippocampal CA1 region of rats exposured to chronic intermittent hypoxia

AIM: To investigate the effect of N-acetylcystein (NAC) on oxidant stress, neuron apoptosis in the hippocampal CA1 region of rats exposured to chronic intermittent hypoxia (CIH). METHODS: 30 healthy male Wistar rats were randomly divided into three groups of 10 each, a CIH group, a NAC therapeutic group and a control group. The levels of MDA and SOD were detected by colorimetric method. Immunohistochemistry was used to examine the expression of p-JNK and TUNEL was used to detect the neuron apoptosis in the hippocampal CA1 region. RESULTS: The level of MDA in NAC group were lower than that in CIH group［(1.71±0.43) μmol/g protein vs （1.37±0.26) μmol/g protein, P<0.05)］. The activity of SOD in NAC group was higher than that in CIH group［(44.94±14.01) 103 NU/g protein vs(57.66±14.07) 103 NU/g protein, P<0.05)］. The expression of p-JNK protein and the apoptotic indices ［(0.39±0.16), (0.20±0.11)］ in NAC group were significantly lower than those in CIH group ［(0.53±0.10), (0.32±0.18), all P<0.05］. CONCLUSION: NAC protects hippocampal neuron from apoptosis by suppressing the oxidant stress in the hippocampal CA1 region and inhibiting the activation of JNK signaling pathway.