Construction of the full length and N-terminal fragment of serum response factor over-expressing lentiviral plasmid and its impacts on cardiac stem cell differentiation / 临床与实验病理学杂志

Purpose To analyze the effects of full length and N-terminal fragment of serum response factor (SRF-Full and SRF-N) on TGF-β1-induced differentiation in c-Kit + cardiac stem cells (CSC).Methods Rat SRF-Full and SRF-N (1-254 aa) coding sequences were obtained from cDNA library and cloned into the linearized lentviral vector GV358 (Ubi-MCS3FLAG-SV40-EGFP-IRES-puromycin) to generate the recombinant vectors,and then positive clones were selected and sequenced after transducing the competent cells with recombinant vectors.The recombinant lentvirus were packaged through transfecting the HEK293T cells with SRF-Full,SRF-N overexpressing plasmids and viral packaging plasmids.Neonatal SD rat cKit + CSCs were isolated via magnetic activated cell sorting,and TGF-β1-induced differentiation in SRF-Full and SRF-N overexpression virus-infected CSCs was assessed by quantitative PCR.Results SRF-Full and SRF-N coding sequences were successfully obtained and properly cloned into the linearized GV358.The positive clones were selected and further confirmed by sequencing.With the help of packaging plasmids,the SRFFull and SRF-N overexpressing plasmids-transfected HEK293T cells successfully produced the lentiviral particles with the titer of 2 × 108 TU/mL,and the SRF-Full-Flag and SRF-N-Flag fusion protein were detected by Western blot in virus-infected HEK293T cells.Addition of TGF-β1 significantly induced upregulated mRNAs in cardiomyocyte markers (Nkx2.5,Gata4,cTnI) and smooth muscle cell marker (SM22α) but not the epithelia cell marker (vWF) in CSCs.Overexpression of SRF-Full facilitated TGF-β1-triggered cardiomyocyte differentiation.However,SRF-N exerted anti-differentiation effects in TGF-β1-treated cells.Conclusion The SRF-Full and SRF-N overexpressing recombinant lentiviral vectors are successfully constructed.SRF-Full facilitates while SRF-N suppresses TGF-β1-induced cardiomyocyte differentiation in c-Kit + CSCs.

Effects of high glucose on expression of OPG and RANKL in rat aortic vascular smooth muscle cells

OBJECTIVE@#To explore effect of high glucose on expression of osteoprotegerin (OPG) and receptor activator of NF- κ B ligand (RANKE) in rat aortic vascular smooth muscle cells.@*METHODS@#SD rats were intraperitoneally injected with streptozotocin, OPG and RANKL expression in rat thoracic aortas were detected by immunohistochemical staining. In cultured vascular smooth muscle cells (VSMCs) (A7r5), qRT-PCR and Western blot analysis were used to examine the mRNA and protein levels of OPG and RANKL.@*RESULTS@#Our results demonstrated that OPG expression was increased in hyperglycemic rat aortic VSMCs, while RANKL expression was decreased. Besides, in vitro experiments high glucose induced OPG expression, but depressed RANKL expression by dose- and time-dependent manner in cultured A7r5.@*CONCLUSIONS@#Our findings suggested that high glucose could promote the expression of OPG, and inhibit the expression of RANKL in VSMCs, which may be partly be the molecular mechanism of diabetic vascular calcification.

Effects of high glucose on expression of OPG and RANKL in rat aortic vascular smooth muscle cells

Objective: To explore effect of high glucose on expression of osteoprotegerin (OPG) and receptor activator of NF- κ B ligand (RANKE) in rat aortic vascular smooth muscle cells. Methods: SD rats were intraperitoneally injected with streptozotocin, OPG and RANKL expression in rat thoracic aortas were detected by immunohistochemical staining. In cultured vascular smooth muscle cells (VSMCs) (A7r5), qRT-PCR and Western blot analysis were used to examine the mRNA and protein levels of OPG and RANKL. Results: Our results demonstrated that OPG expression was increased in hyperglycemic rat aortic VSMCs, while RANKL expression was decreased. Besides, in vitro experiments high glucose induced OPG expression, but depressed RANKL expression by dose- and time-dependent manner in cultured A7r5. Conclusions: Our findings suggested that high glucose could promote the expression of OPG, and inhibit the expression of RANKL in VSMCs, which may be partly be the molecular mechanism of diabetic vascular calcification.

p42/p44 mitogen-activated protein kinases inhibit atrial natriuretic peptide mRNA transcription in gp130-mediated hypertrophic ventricular myocytes

OBJECTIVE@#To understand the role of ANP mRNA transcription regulation in gp130-mediated cardiomyocyte hypertrophy, and the involved mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK, also called p42/p44 MAPK) signaling pathway.@*METHODS@#Isolated neonatal ventricular myocytes were treated with different concentrations of CT-1 (10(-9), 10(-8)and 10(-7)mol/L). MTT was used to analyze the viability and RT-PCR was used to detect ANP mRNA levels in cardiomyocyte. To inhibit p42/p44 MAPK activity in hypertrophic cardiomyocytes, the cells were pretreated with a specific MEK1 inhibitor.@*RESULTS@#CT-1 significantly induced ANP mRNA expression and the viability of cardiomyocytes in a dose- and time-dependent manner. Furthermore, blocking p42/p44 MAPK activity by the special MEK1 inhibitor upregulated the ANP mRNA.@*CONCLUSIONS@#p42/p44 MAPK have an important role in suppressing ANP mRNA transcription and cell activity in gp130-mediated hypertrophic ventricular myocytes.

The anti-apoptotic effect of cytoplasmic alpha-fetoprotein in hepatoma cells induced by all-trans retinoic acid involves activation of the PI3K/AKT signaling pathway / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the effect of alpha-fetoprotein (AFP) on transduction of the PI3K/ AKT signal in hepatocellular carcinoma cells and the role played by AFP in resistance to cytotoxicity of all-trans retinoic acid (ATRA).</p><p><b>METHODS</b>The effects of ATRA of human liver cancer cells was assessed using the BEL-7402 cell line with the MTT assay (to evaluate proliferation), microscopy (to evaluate morphology), flow cytometry (to evaluate apoptosis), laser confocal microscopy and coimmunoprecipitation (co-IP; to evaluate co-localization and interaction of AFP with PTEN), Western blotting (to evaluate expression of phosphorylated-protein kinase B (pAKT) and Src, and RNA interference (RNAi)-mediated knockdown of AFP. Finally, application of the PI3K-specific inhibitor Ly294002 was used to monitor the influence of AFP in transduction of the PI3K signal pathway.</p><p><b>RESULTS</b>The human hepatoma cell line BEL-7402 were resistant to ATRA cytotoxicity. PTEN and AFP co-localized in the cytoplasm, and co-IP indicated that AFP interacts with PTEN in BEL-7402 cells.RNAi knockdown of AFP expression led to reduced growth of BEL-7402 cells.BEL-7402 cells transfected with AFP-short interfering (si)RNA vectors showed enhanced sensitivity to ATRA and reduced expression of pAKT(Ser473) and Src; Ly294002 reduced the role of AFP in stimulating expression of pAKT(Ser473) and Src.</p><p><b>CONCLUSION</b>AFP can activate transduction of the PI3K/AKT signal, and expression of AFP in hepatoma cells is a pivotal event for resisting ATRA-induced apoptosis.</p>

Construction and characterization of a full-lengh cDNA library from non-fresh Giardia lamblia

OBJECTIVE@#To construct rapidly a full-length cDNA library from nanogram amounts total RNA of Giardia lamblia (G. lamblia) trophozoites stocked in RNA stabilization reagent.@*METHODS@#Total RNA of Giardia was extracted using Trizol reagent. A full-length cDNA library of G. lamblia trophozoites was constructed by a long-distance PCR (LD-PCR) method. The recombinant rate and the coverage rate of full-length clones of the library were evaluated. The inserted fragments were identified and sequenced by PCR amplification.@*RESULTS@#The titer of cDNA library was 3.85 × 10(7) pfu/mL. The length of inserted fragments ranged from 0.4 to 2.5 kb, and the recombination efficiency accounted for 100% (20/20). The coverage rate of full-length clones is high (17/20).@*CONCLUSIONS@#The RNA stabilization reagent may be used to fix the cells and prevent the RNA in cells even though delivered under normal atmospheric temperature. The long-distance PCR can be used to construct a full-length cDNA library rapidly and it needs less RNA than the traditional method from mRNA.

Inhibition of Pim-1 attenuates the proliferation and migration in nasopharyngeal carcinoma cells

OBJECTIVE@#To explore the role of proto-oncogene Pim-1 in the proliferation and migration of nasopharyngeal carcinoma (NPC) cells.@*METHODS@#Pim-1 expressions in NPC cell lines CNE1, CNE1-GL, CNE-2Z and C666-1 were examined by RT-PCR, western blotting and immunoflucesence, respectively. After CNE1, CNE1-GL and C666-1 cells were treated with different concentrations of Pim-1 special inhibitor, quercetagetin, the cell viability, colony formation rate and migration ability were analyzed.@*RESULTS@#Pim-1 expression was negative in well-differentiated CNE1 cells, whereas expressed weakly positive in poor-differentiated CNE-2Z cells and strongly positive in undifferentiated C666-1 cells. Interestingly, CNE1-GL cells that derived from CNE1 transfected with an Epstein Barr virus latent membrane protein-1 over-expression plasmid displayed stronger expression of Pim-1. Treatment of CNE1-GL and C666-1 cells with quercetagetin significantly decreased the cell viability, colony formation rate and migration ability but not the CNE1 cells.@*CONCLUSIONS@#These findings suggest that Pim-1 overexpression contributes to NPC proliferation and migration, and targeting Pim-1 may be a potential treatment for anti-Pim-1-expressed NPCs.

Toxicarioside A, isolated from tropical Antiaris toxicaria, blocks endoglin/TGF-β signaling in a bone marrow stromal cell line

OBJECTIVE@#To investigate possible mechanism of toxicarioside A in HS-5 bone stromal cells.@*METHODS@#HS-5 bone stromal cells were cultured in media supplemented with various concentrations of toxicarioside A or control DMSO (not treatment). Endoglin and TGF-β were detected by Northern and Western blot analysis and quantified in a standard method. Downstream molecules of endoglin and TGF-β (Smad1, Smad2 and their active phosphorylated counterparts, pSmad1 and pSmad2) were also detected and quantified by Western blot analysis. In addition, cell proliferation assay and small interfering RNA (siRNA) against endoglin were used to certificate the function of endolgin in the HS-5 cells.@*RESULTS@#Compared with the not treated (0 μg/mL) or DMSO treated control HS-5 cells, HS-5 cells treated with toxicarioside A were found significant attenuation of endolgin and TGF-β expression. Significant inhibition of cell proliferation was also found in the HS-5 cells treated with toxicarioside A. ALK1-related Smad1 and ALK5-related Smad2 were decreased in HS-5 cells treated with toxicarioside A. In addition, phosphorylated Smad1 (pSmad1) and Smad2 (pSmad2) were also found attenuation in toxicarioside A-treated HS-5 cells. RNA interference showed that blockage of endoglin by siRNA also decreased Smad1 and Smad2 expression in HS-5 cells.@*CONCLUSIONS@#Our results indicate that toxicarioside A can influence bone marrow stromal HS-5's function and inhibit HS-5 cell proliferation by alteration of endoglin-related ALK1 (Smad1) and ALK5 (Smad2) signaling.

Matrine inhibits the proliferation of prostate cancer cells and the activity of androgen receptor / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the inhibitory effect of matrine on the proliferation of the prostate cancer cell line LNCaP and the expression of the androgen receptor (AR).</p><p><b>METHODS</b>LNCaP cells were treated with matrine at the concentration of 0.5, 1.0, 1.5, 2.0 and 3.0 g/L for 12, 24 and 36 hours, the cell growth activity determined by MTT colorimetry and trypan blue staining at 36 hours, the cell cycle changes detected by flow cytometry and the expression of AR by Western blot at 24 hours.</p><p><b>RESULTS</b>Matrine suppressed the in vitro growth of the androgen-sensitive prostate cancer cell line LNCaP in a time- and dose-dependent manner, blocked the cell cycles in the G2/M phase and decreased the expression of AR in the cell line in a dose-dependent manner (P < 0.01).</p><p><b>CONCLUSION</b>Matrine can significantly inhibit the in vitro growth of NCaP cells by down-regulating the expression of AR and blocking cell cycles.</p>