Osteogenic and neurogenic differentiation of human yolk sac mesenchymal stem cells

AIM: To purify human yolk sac mesenchymal stem cells (hYS-MSC) and investigate its osteogenic and neurogenic differentiation potentials. METHODS: hYS-MSC were separated from yolk sac and purified via passage culture. The karyotype of hYS-MSCs was analyzed via G-banded characteristics. Flow cytometric analysis was used to determine the cell cycle and phenotype of hYS-MSC. The AKP expression of hYS-MSC was also tested. Osteogenic differentiation of hYS-MSCs was induced by 10-8mol/L dexamethasone, 10 mmol/L β-glycerophosphate and 50 mg/L vitamin C. Alizarin red S stain was used for identification of mineralization. β-mecaptoethanol or salviae miltiorrhizae were used to induce neurogenic differentiation of hYS-MSCs. The expressions of NSE, NF and GFAP were identified by immunohistochemical method. RESULTS: hYS-MSCs could be purified at passages 2 or 3. The cell cycle analysis suggested that hYS-MSCs showed strong proliferational potentials by which the cells kept normal diploid karyotype during the in vitro culture. Flow cytometry showed the phenotype of purified hYS-MSCs was uniformly positive for CD29, CD44, CD105, and CD166, and negative for reactivity to antigens CD34, CD45, or CD86. hYS-MSCs were weakly but clearly positive in AKP. Osteogenic differentiation was appeared after induction of osteogenic differentiation. hYS-MSCs, which were of spindle shape, uniform in size, were induced to pleomorphism osteoblast-like cells which expressed high level of AKP. Aggregates or nodules were formed at day 7 and calcium accumulation was detected by alizarin red S staining on day 10 or day 14. Neurogenic differentiation of hYS-MSCs was induced by β-mecaptoethanol or salviae miltiorrhizae. NSE, NF or GFAP positive cells were detected by immunohistochemical staining. CONCLUSIONS: hYS-MSCs have strong proliferation potential and the normal diploid karyotype is kept during the in vitro culture. The phenotype of hYS-MSCs is coincident with adult hMSCs. hYS-MSCs could be induced to differentiate into osteogenic or neurogenic cells.     

Effect of inhaled nitric oxide on adhesion molecule CD11b expression in lung neutrophils of meconium aspiration rabbits

AIM:To evaluate effects of inhaled nitric oxide(iNO) on adhesion molecule CD11b expression on lung neutrophils in experimental meconium aspiration syndrome(MAS) rabbits treated with conventional mechanical ventilation under room air or 100%O₂. METHODS:Animals were randomly allocated to 8 groups(n=48) of 6 each: two MAS model groups(under room air or 100%O₂ without iNO treatment), 6 treatment groups were treated with continuous NO inhalation at a dose of 0.2×10^-6mol/L, 0.33×10^-6mol/L or 0.67×10^-6mol/L respectively for 12 hours under room air or 100%O₂. Mean systemic arterial pressure(SAP) and methemoglobin (MeHb) were performed at basement time, 0, 2, 4, 12 hours. Expression of CD11b on neutrophils in the bronchoalveolar lavage fluid(BALF) was detected with flow cytometry. RESULTS:SAP, MeHb at different time among different groups were within the normal scale. CD11b expression on the neutrophils in the BALF significantly decreased in groups of inhalation 0.33×10^-6 mol/L or 0.67×10^-6 mol/L NO, compared with the two MAS model groups. (x±s: under 21%O₂, 0.33×10^-6 mol/L NO, 121±20 υs 392±204; 0.67×10^-6 mol/L NO, 112±30 υs 392±204;under 100%O₂, 0.33×10^-6 mol/L NO, 113±24υs293±65; 0.67×10^-6 mol/L 102±114 υs293±65, P<0.05). 0.2×10^-6mol/L NO inhalation did no effect on CD11b expression. (x±s:21%O₂, 190±101 υs 392±204; 100%O₂, 222±85 υs 293±65; P>0.05). No statistic difference was observed between groups inhaled 0.33×10^-6 mol/L NO and 0.67×10^-6mol/L NO. CONCLUSION:0.33×10^-6 mol/L or 0.67×10^-6 mol/L NO inhalation down-regulated the CD11b expression on the neutrophils in BALF to reduce the sequestration of neutrophils in rabbit lung.     

Antagonistic effect of captopril on activation and injury of vascular endothelial cells induced by lipopolysaccharide

AIM: To investigate the antagonistic action of Captopril (Cap) on the activation and injury of human umbilical vascular endothelial cells (HUVECs) induced by lipopolysaccharide(LPS) and the possible mechanisms. METHODS: After 18 h exposure of the cultured HUVECs to LPS (1 mg/L), or LPS (1 mg/L) plus Cap at the concentration of 10^-7mol/L, 10^-5mol/L and 10^-3mol/L, the expression of vWF protein in the conditioned media was tested by enzyme-linked immunosorbent assay (ELISA), the expression of ICAM-1 protein in HUVECs was determined by indirect immunofluorescence technique with flow cytometry as well. In addition, the expression of TNFα mRNA was determined by in situ hybridization. RESULTS: The results of ELISA and indirect immunofluorescence technique showed that exposure to LPS at a concentration of 1 mg/L led to a significant increase in the vWF and ICAM-1 expression in HUVECs as compared to the control (P＜0. 05), whereas they were somewhat decreased when exposed to Cap at three increasing concentrations mentioned above, especially in the Cap (10^-3mol/L) plus LPS group (P＜0.05). Cap inhibited vWF secretion and ICAM-1 expression of HUVECs caused by LPS in a concentration-dependent manner. In situ hybridization revealed that the expression of TNFα mRNA was inhibited by Cap both in a concentration of 10^-3mol/L, and in a lower concentration of 10^-5mol/L. CONCLUSION: Cap antagonizes the activation and injury of HUVECs induced by LPS, which may be related to the decrease in TNFα mRNA expression.     

Meglumine cyclic adenylate induces differentiation of bone marrow mesenchymal stem cells into cardiomyocytes in vitro

AIM: To study the effect of meglumine cyclic adenylate (MCA) on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into cardiomyocytes in vitro. METHODS: The whole bone marrow adherent culture method was used to isolate, culture and amplify the BMSCs. The surface markers of BMSCs were determined by flow cytometry analysis. MCA at concentrations of 10^-2 mol/L, 10^-3 mol/L, 10^-4 mol/L, 10^-5 mol/L, 10^-6 mol/L and 10^-7 mol/L was added to the culture medium containing the second generation of BMSCs.5-Azacytidine(5-Aza) was used as a positive control. The cell viability was measured by MTT method.The cAMP content in BMSCs was detected by ELISA. The mRNA expression of GATA-4, Cx43 and β-MHC in MCA group and MCA+H89 (a PKA inhibitor) group was measured by SYBR-RT-PCR. The differentiation effects of MCA and 5-Aza were compared by flow cytometry. RESULTS: Most of the BMSCs expressed CD44 and CD71, and did not express CD45. MCA inhibited the viability of BMSCs in a time-and dose-dependent manner, and MCA atthe concentration of 10^-2 mol/L showed particularly remarkable effect. MCA significantly increased intracellular cAMP level in BMSCs in a concentration-dependent manner. The mRNA expression of GATA-4, β-MHC and Cx43 in MCA group were significantly higher than that in blank group (P<0.05), and the highest effect was under the condition of MCA induction at the concentration of 10^-3 mol/L for 3 days. The mRNA expression of GATA-4, β-MHC and Cx43 in MCA group was higher than that in 5-Aza group and H89+MCA group (both P<0.05). Differentiation rate in MCA group was slightly higher than that in 5-Aza group (20.24%±1.02% vs 18.39%±0.58%, P<0.05). CONCLUSION: MCA stimulates BMSCs to increase intracellular cAMP production and inhibits the viability of BMSCs, thus promoting the mRNA expression of GATA-4, β-MHC and Cx43 through the cAMP/PKA signaling pathway.     

Inhibitory effects of dexamethasone on the expression of integrin CD18 induced by PMA

AIM:To study the effect of dexamethasone(Dex) on the expression of CD18. METHODS:Quantitative RT-PCR analysis, Northern blotting technique were used to measure the expression of CD18 in U937 cells treated by PMA.RESULTS:Dex could significantly attenuated the effects of PMA in a dose-dependent manner (10^-6 mol/L-10^-10 mol/L). These effects of Dex (10^-7 mol/L) were completely aborted by RU-486 (10^-6 mol/L).CONCLUSION:Dex, via GR, could inhibit CD18 mRNA expression in U937 cells treated by PMA. The effects of Dex might be possibly depended on the counteracting action on the NF-κB.     

AngiotensinⅡ activates autophagy pathway through elevating ROS level in vascular endothelial cells

AIM: To evaluate the effects of angiotensinⅡ (AngⅡ) on autophagy induction in vascular endothelial cells. METHODS: Human vascular endothelial EA.hy926 cells were used in the study. Intracellular reactive oxygen species (ROS) levels were detected by a microplate reader after the cells were treated with AngⅡ (10^-7 mol/L) or AngⅡ combined with antioxidant N-acetyl-L-cysteine (NAC,50 μmol/L) for 24 h. The protein levels of LC3-Ⅱ was detected by Western blotting after the cells were stimulated by different concentrations (10^-8, 10^-7, 10^-6 mol/L) of AngⅡ for 24 h or by AngⅡ (10^-7mol/L) for different time (0 h, 6 h, 12 h, 24 h, 36 h). The number of autophagosomes was evaluated by fluorescence microscopy after stained with acridine orange. Similarly, the protein level of LC3-Ⅱ and the number of autophagosomes were detected after treated with AngⅡ(10^-7mol/L), AngⅡ combined with autophagy inhibitor 3-methyladenine (3-MA) at concentration of 2 mmol/L or AngⅡ combined with NAC at concentration of 50 μmol/L. RESULTS: Intracellular ROS level and LC3-Ⅱprotein level were significantly increased (P<0.05) after the cells were treated with AngⅡ, accompanied by the significant increase in the number of autophagosomes. AngⅡ-induced autophagy (as showed both in LC3-Ⅱprotein level and autophagosomes) was dramatically down-regulated by the treatment with 3-MA or NAC in EA.hy926 cells (P<0.05). CONCLUSION: AngⅡ induces autophagy through elevating ROS levels in EA.hy926 cells.     

Effects of adrenomedullin on proliferation of vascular smooth muscle cells induced by urotensin Ⅱ

AIM:To observe the effect of adrenomedullin(ADM)on proliferation of vascular smooth muscle cells(VSMC) induced by urotensin Ⅱ(UⅡ). METHODS:DNA synthesis of cultured rat aortic VSMC was measured by [³H]-TdR incorporation. The activities of mitogen activated protein kinase(MAPK) were determined by isotope tagged with [γ-³²P]-ATP. RESULTS:UⅡ(10^-8mol/L) significantly increased [³H]-TdR incorporation of VSMC and MAPK activities by 38%(P＜0.05) and 260%(P＜0.01) respectively compared with control group. Compared with UⅡ group, 10^-10,10^-9,10^-8mol/L ADM decreased [³H]-TdR incorporation of VSMC by 7%(P＞0.05), 32%(P＜0.05)and 41%(P＜0.01),respectively, and diminished MAPK activities by 24%(P＞0.05), 32%(P＜0.05)and 36%(P＜0.05),respectively. CONCLUSION:ADM inhibits proliferation of VSMC induced by urotensin Ⅱ through inhibiting MAPK activation.     

Inhibitory effect of hydrogen sulfide (H2S) on cultured rat aortic smooth muscle cells

AIM:To explore the effects of hydrogen sulfide (H₂S) on proliferation of vascular smooth muscle cells (VSMC) stimulated by endothelin (ET-1, 10^-7mol/L) and mitrogen-activated protein kinase (MAPK) activity in VSMCs.METHODS:Cultured VSMCs were divided into six groups: (1) control group, (2) serum group, (3) endothelin group, (4) NaHS groups, (5) serum+NaHS group, and (6) endothelin+NaHS group. VSMC proliferation was measured by[³H]-TdR incorporation and MAPK activity in VSMC was determined by radioactivity assay.RESULTS:ET-1 increased VSMC[³H]-TdR incorporation by 2.39 times (P＜0.01) and MAPK activity by 1.62 times(P＜0.01), as compared with control. H₂S (5×10^-5-5×10^-4mol/L) decreased VSMC[³H]-TdR incorporation and MAPK activity by 16.8%-37.4% and 7.4%-33.6%, respectively (P<0.05 or P＜0.01).CONCLUSION:This study demonstrates that H₂S inhibits ET-1-induced proliferation of VSMC, which might be mediated by the inhibition of MAPK.     

Inhibition of endothelin on taurine-transportation in rat cardiac myocytes

AIM:To investigate the effect of endothelin(ET) on taurine transportation in rat cardiac myocytes in vitro.METHODS: In cultured cardiac myocytes of neonatal rats, taurine transportation velocity was measured by radio-ligand method. RESULTS: ET(10^-10-10^-8 mol/L) could inhibit taurine transportation in a dose-dependent manner.10^-10,10^-9 and 10^-8mol/L of ET significantly decreased taurine transpotation by 13%, 38% and 71%, respectively (P＜0.01), compared with control group. H₇,BQ123 and Pre-PMA can reverse the inhibition of ET on taurine transportation dramatically(P＜0.01).CONCLUSION:The binding of ET and ET-A receptor might activate protein kinase C,which inhibits taurine transportation in cultured myocytes of rats.     

Effect of gonadotropin-releasing hormone analogue on human breast cancer cell line in vitro

AIM: To investigate the effects of gonadotropin-releasing hormone (GnRH) analogue on the growth of breast cancer cell lines MCF-7 and MDA-MB-231 in vitro and to explore the related mechanisms with PI3K/Akt or ERK/MAPK pathways. METHODS: The proliferation of human breast cancer cell lines MCF-7 and MDA-MB-231 treatment with triptorelin was detected by MTT assay and the distribution of the cell cycle was determined by flow cytometry. The phosphorylation of the ERK1/2 and Akt was evaluated by Western blotting. RESULTS: Triptorelin inhibited the proliferation of MCF-7 cells at concentration of 10^-5 mol/L after treated for 192 h or at concentration of 10^-4 mol/L after treated for 168 h and 192 h. Triptorelin inhibited the proliferation of MDA-MB-231 cells at concentration of 10^-4 mol/L after treated for 192 h (P<0.05).Treatment with triptorelin for 192 h at concentration of 10^-4 mol/L had no statistical significance effect on phosphorylation of ERK1/2 and Akt(P>0.05).CONCLUSION: Inhibitory effect of GnRH analogue triptorelin on human breast cancer cells is not just the connection with the down-regulation of pituitary hormone, but also a direct inhibitory effect. The role may not be involved in the activation of ERK/MAPK and PI3K/Akt signaling pathways.     

The relations among PAMP,ADM and AngⅡ on vascular tissue

AIM: To elucidate the relations among proadrenomedullin N terminal 20 peptide(PAMP), adrenomedullin(ADM)and angiotensin(Ang).METHODS: Tissue slices of rat aorta were incubated as follows:(I) increasing concentrations of AngⅡ(10^-9, 10^-8, 10^-7 mol/L); increasing concentrations of PAMP(10^-9,10^-8,10^-7mol/L).The tissue and incubation concentrations of PAMP,ADM and AngⅡ were measured by the radioimmunoassay (RIA).RESULTS: The tissue and incubation concentrations of PAMP and ADM were concentration-dependently increased by AngⅡ,but the tissue and incubation concentrations of AngⅡ can not effected by PAMP.CONCLUSION: AngⅡ markedly stimulate the release of ADM and PAMP.It may be one of the factors which regulate the synthesis and release of ADM and PAMP.The regulation may play an important role in homeostasis regulation of cardiovascular system.     

Inhibitory effect of cholecystokinin octapeptide on expression of CD14 on rat pulmonary interstitial macrophages induced by lipopolysaccharide in vitro

AIM:To study the effect of cholecystokinin octapeptide(CCK-8) on lipopolysaccharide (LPS)-stimulated pulmonary interstitial macrophage(IM)in vitro.METHODS:Pulmonary IM were isolated and cultured in the presence of LPS, CCK-8, proglumide(the antagonist of CCK receptors) and vehicle alone or together. The expression of mCD14 protein was assayed by flow cytometry, and sCD14 in the supernatant was analyzed semi-quantitatively by Western blot, and TNF-α in the supernatant was detected with ELISA.RESULTS:CCK-8, at concentrations from 10^-7mol/L to 10^-6mol/L inhibited significantly the expression of mCD14, the release of sCD14 and TNF-α to the supernatant up-regulated by LPS(1mg/L). The effect of CCK-8 was inhibited by proglumide. CONCLUSION:CCK-8 modulated negatively several functions of LPS-stimulated pulmonary IM through CCK receptors, which may be one of the mechanisms for CCK-8 to alleviate the inflammation in lung tissues during endotoxemia.     

Effects of nicotine on activation of PMNs and the ICAM-1 mRNA expression of HUVEC

AIM: To investigate the effects of nicotine on activation of PMNs, adhesion of PMNs-HUVEC and expression of ICAM-1 mRNA in HUVEC. METHODS: Activation of PMNs was measured by detecting the activity of β-glucuronidase and lysozym of PMNs. Adhesion of PMNs and HUVEC was observed. Northern blot was conducted for quantitating ICAM-1 mRNA. RESULTS: Nicotine could increase the activity of β-g [(8.76± 1.01)μg/10⁷·h vs(14.87±2.00)μg/10⁷·h,P<0.05]and Lysozym [(20.0±1.5)μg/10⁷·h vs(36.5±4.4)μg/10⁷·h,P<0.05], and also could promote adhesion of PMNs-HUVEC(38.5±9.8 vs 61.0±4.4,P＜0.05). The expression of ICAM-1 mRNA was induced by nicotine in dose-dependent fashion (10^-5-10^-3mol/L).After a 2 h treatment of HUVEC with nicontine(10^-4mol/L), the level of ICAM-1 mRNA is above the control(1.23 vs 1.63) and the highest level (2.03) is at a 12 h treatment. 764-3 can obviously counteract the above effect of nicotine. CONCLUSIONS: Nicotine could activate PMNs, enhance adhesion of PMNs-HUVEC and increase the expression of ICAM-1 mRNA in HUVEC.     

Effect of dexamethasone or theophylline on platelet-activating factor-induced eosinophils

AIM: To elucidate the effects of platelet-activating factor (PAF) on eosinophil activation and the action of dexamethasone or theophylline during this process. METHODS: Eosinophils (EOS) from the peripheral blood of normal subjects were isolated. The hypodense eosinopil (HE) and normodense eosinophil (NE) were studied with electron microscopy. The effects of PAF on eosinophil activation and the action of dexamethasone or theophylline during the above process were measured. RESULTS: Hypodense eosinophil had significantly smaller individual granules than normodense eosinophil had. PAF induced eosinophil peroxidase release, and generated. Eosinophils incubated with 10^-8 mmol/L PAF and 10^-5 mmol/L dexamethasone released (101.17±10.32) mg/L eosinophil peroxidase (P<0.05). Eosinophils incubated with 10^-9 mol/L PAF and 10^-5 mmol/L dexamethasone caused a decrease in eosinophil peroxidase (110.85±4.16) mg/L and induced the generation of hypodense eosinophil (17.87%±2.16%). Eosinophils incubated with 10^-8 mmol/L PAF and 10 mg/L theophylline released (100.53±9.65) mg/L eosinophil peroxidase (P<0.05). Eosinophils incubated with 10^-9 mol/L PAF and 10 mg/L theophylline caused a similar decrease in eosinophil peroxidase (106.94±10.11) mg/L and induced the generation of hypodense eosinophil (14.08%±2.42%). CONCLUSIONS: Eosinophil degranulation is one of the reasons by which hypodense eosinopils develop. PAF induced eosinophil degranulation, so generated hypodense eosinopils. Dexamethasone and theophylline inhibited above effects.     

Sca-1+ cells from mouse fetal liver can differentiate into neurons in vitro

AIM: To study whether Sca-1⁺ cells from fetal liver can be induced to differentiate into neuronal cells in vitro. METHODS:Sca-1⁺cells from 14 5-days-old murine fetal liver were isolated with a magnetic cell sorting kit, and were cultured in Dulbecco s modif ied Eagle s medium(DMEM)/F12 supplemented with 10%fetal bovine serum(FBS), and passaged at a rat io of 1 3 when cells reached more than 80%confluence.The 5 passage cells were induced by 10^-3mol/Lβ-mercaptoethanol(β-ME)and 5×10^-7 mol/L all-trans-retinoic acid(RA)for 24 hours, and then incubated in serum-free medium for 5 hours to 5 days.The characteristics of treated cel s were assayed by immunocytochemistry staining analysis at 5 hours, or 5 days.RESULTS: Cells treated with β-ME and RA exhibited neuronal phenotype and expressed neuron-specific protein such as neuron-specific nuclear protein (NeuN), neuronfilament-M, and neuron-specific tubulin-1 (TuJ-1) but not tau, MAP-2, or the astrocyte-specific marker glial fibrillary acidic protein (GFAP).CONCLUSION: Sca-1⁺ cells from fetal liver, of which most are regarded as hematopoietic stem cells, could differentiate into early immature neuronal cells in vitro. These findings suggest that Sca-1⁺ cells from fetal liver may be an alternative source in cell therapy and gene therapy of neural dysfunction.     

Expression of bFGF mRNA in pulmonary artery of rat with chronic hypoxia and its effect on tension of rat pulmonary artery in vitro

AIM: To explore the role of basic-fibroblast growth factor (bFGF) in the development of pulmonary hypertension induced by hypoxia. METHODS: 1) The pulmonary arteries of SD rats with hypoxia for one and two weeks were isolated, from which the total RNA were extracted by acid guanidinium thiocyanate-phenol-chlorform .Then the levels of mRNA were measured by RT-PCR. 2) About 3mm-long arterial rings cut from SD rat pulmonary arterial stem were suspended between stainless steelhooks in chamber with warmed (37℃) Kreb's solution. Different concentrations of bFGF were added in a cumulative fashion into the chamber where the rings were suspended. The cumulative concentration response curve was obtained. RESULTS: 1)The levels of bFGF mRNA in pulmonary artery of rats with hypoxia were increased significantly compared with those that without hypoxia (2578±384 counts·min^-1 (control) vs 5303±756 (hypoxia) for 1 week and 4054±547 (hypoxia) for 2 weeks, P all ＜0.05). 2) bFGF at concentrations ranged from 5.56×10^-10~2.78×10^-7mol/L caused dose-dependent contraction of vessel rings of rat pulmonary artery (r=0.695,P＜0.05), with EC₅₀ being 2.62×10^-7mol/L. CONCLUSION: bFGF may play an important role in the hypoxic pulmonary hypertension.     

Farrerol inhibits nicotine-induced proliferation of pulmonary vascular smooth muscle cells by enhancing Kv1.5 and Kv2.1 expression

AIM:To study the effect of farrerol (Far) on nicotine-induced proliferation of rat pulmonary smooth muscle cells (PASMCs), and further to explore its relationship with voltage-dependent potassium channels (Kv) 1.5 and Kv2.1. METHODS:Firstly, the effect of nicotine on the proliferation of PASMCs was detected by cell counting method, and the optimal concentration of nicotine was selected. Primary cultured PASMCs were randomly divided into 5 groups:normal control group, nicotine (1 μmol/L)group, nicotine (1 μmol/L) + Far (10^-6 mol/L, 10^-5 mol/L and 10^-4 mol/L) Far group. The activity of caspase-3 was measured by apoptosis kit, the cell viability was measured by CCK-8 assay, the apoptotic rate was analyzed by flow cytometry. The expression of Kv1.5 and Kv2.1, and apoptosis-related factors Bcl-2 and Bax at mRNA and protein levels was determined by RT-qPCR and Western blot respectively. RESULTS:Nicotine at 1 μmol/L increased the number of PASMCs to the maximum extent (P<0.01). Nicotine at 1 μmol/L significantly reduced the caspase-3 activity and enhanced the cell viability of the PASMCs (P<0.01). Farrerol at 10^-6~10^-4 mol/L eliminated the effect of PASMCs induced by nicotine in a concentration dependent manner. Compared with control group, nicotine at 1 μmol/L significantly increased the proliferation and inhibited the apoptotic rate of rat PASMCs (P<0.01). The apoptotic rate of PASMCs in farrerol intervention group was significantly higher than that in nicotine group (P<0.01). Nicotine at 1 μmol/L significantly inhibited the expression of Kv1.5, Kv2.1 and Bax but increased the expression of Bcl-2 in PASMCs (P<0.01). Farrerol at 10^-5 mol/L obviously inhibited the effect of PASMCs induced by nicotine. CONCLUSION:Farrerol eliminates nicotine-induced inhibition of caspase-3 and Bax, and enhancement of Bcl-2 in PASMCs by enhancing Kv1.5 and Kv2.1 expression.     

Effect of pioglitazone on pre-adipocytes differentiation and GILZ expression

AIM: To investigate the roles of pioglitazone on differentiation and expression of GILZ in 3T3-L1 pre-adipocytes. METHODS: The morphological changes during 3T3-L1 cell differentiation were observed. The cells were treated with pioglitazone at concentrations of 1×10^-4～1×10^-2 mmol/L for 48 h, then the relative content of triglyceride were analyzed by oil red O staining at 2nd, 4th and 6th day during adipogenesis. The mRNA expression of peroxisome proliferator-activated receptor γ2 (PPARγ2) and lipoprotein lipase (LPL) was measured by real-time PCR. GILZ protein expression was determined by Western blot after the cells were treated with pioglitazone at concentrations of 1×10^-4 ～1×10^-2 mmol/L for 48 h.RESULTS: Oil-red O staining showed that the relative contents of triglyceride in adipocytes were increased with the increase in the pioglitazone concentration. Compared with the control, the relative contents of triglyceride in group 1×10^-3 mmol/L and group 1×10^-2 mmol/L were significantly increased (P < 0.05). The mRNA expression of PPARγ2 and LPL was also increased with the increase in the pioglitazone concentration. When pioglitazone concentration was more than 1×10^-3 mmol/L, compared with the control, the mRNA expression of PPARγ2 and LPL significantly increased (P < 0.01). The protein expression of GILZ was decreased with the increase in the pioglitazone concentration.CONCLUSION: Pioglitazone down-regulates GILZ expression, and up-regulate PPARγ2 expression and the downstream functional factor such as LPL.