Elevated GTP Cyclohydrolase I Pathway in Endothelial Progenitor Cells of Overweight Premenopausal Women.

Background/Aims. Sexual differences exist in endothelial progenitor cells (EPCs), and various cardiovascular risk factors are associated with the preservation of endothelial function in premenopausal women. However, it is unclear whether differences in endothelial function and circulating EPCs exist between overweight premenopausal women and age-matched men. Methods. We compared EPC counting and functions in normal-weight and overweight premenopausal women and men, evaluated endothelial function in each group, and detected the expression of the guanosine triphosphate cyclohydrolase I (GTPCH I) pathway. Results. The number of EPCs was lower in the male group than in the female group, regardless of normal-weight or overweight status, and there was no significant difference between the different weight groups among females or males. Endothelial function and EPC migration and proliferation were preserved in overweight premenopausal women compared with overweight men as were nitric oxide (NO) levels in plasma and secreted by EPCs. Endothelial function, the circulating EPC population, and NO levels were not different between normal-weight and overweight premenopausal women. Flow-mediated dilatation was significantly correlated with EPC function, plasma NO levels, and EPC-secreted NO. Conclusions. This investigation provides the first evidence for sex-based differences in EPC activity and endothelial function in overweight middle-aged individuals; these differences are associated with alterations in NO production and may partly occur through downregulation of the GTPCH I pathway. The present results provide new insights into the mechanism underlying the preserved endothelial function in overweight premenopausal women and may uncover a potential therapeutic target for endothelial repair in overweight population.

Inhibition of Adipogenesis Is Involved in the Protective Effects of 1,25-Dihydroxy Vitamin D3 on the Radiation-Injured Bone Marrow Microenvironment in Mice.

To explore the protective effects of 1,25-dihydroxy vitamin D3 (1,25-(OH)2D3) on the bone marrow microenvironment in mice after irradiation and the underlying molecular mechanisms, a total of 150 7-wk-old male BALB/c mice were randomly divided into a normal group, an irradiation (IR) group and an irradiation+1,25-(OH)2D3 (IR+VD3) group. The mice in the IR+VD3 group were treated with 6.0 Gy 60Coγ rays, and 1,25-(OH)2D3 (dissolved in DMSO, 2.5 µg/kg) was administered once per day from 2 d before to 8 d after irradiation. Mice in the IR group were treated with the same dose of γ rays and an equal volume of DMSO. Subsequently, the body weights and the numbers of peripheral white blood cells (WBCs) were measured. Histological analysis of femur bone marrow was conducted to determine the proportion of adipose area as well. Finally, the expression of peroxisome proliferator-activated receptor-gamma (PPARγ) in bone marrow was detected by immunohistochemistry. After irradiation, the percentage of adipose area in the bone marrow was significantly increased, and the WBC number and body weight were markedly reduced. Compared with irradiation alone, the co-administration of 1,25-(OH)2D3 with irradiation markedly attenuated radiation-induced adipogenesis in bone marrow, resulted in fewer bone marrow stromal cells expressing PPARγ and enhanced the recovery of body weight and WBCs. These results indicate that 1,25-(OH)2D3 could accelerate the recovery of body weight and WBCs in irradiated mice and protect the bone marrow by inhibiting radiation-induced adipogenesis via the down-regulation of PPARγ expression.

[Effects of dihydroartemisinin on radiosensitivity of Raji cells].

OBJECTIVE: To study the effects of dihydroartemisinin (DHA) on radiation sensitivity of Raji cells, and explore its mechanisms. METHODS: CCK8 was used to determine the effect of DHA on cell viability of Raji cells; apoptosis, intracellular reactive oxygen speies(ROS) and mitochondrial membrane potential of Raji cells were detected by flow cytometry; and the protein expressions of protein kinase B(AKT), phospho-rylated-protein kinase B(p-AKT), Bcl-2 and Bax were determined by Western blot. RESULTS: The cells were randomly divided into four groups:control group, DHA(5µmol/L DHA), irradiation(IR, 4 Gy), IR+DHA group (4 Gy IR+5 µmol/L DHA). Compared with the other three groups, cells in DHA+IR group exhibited lower mitochondrial membrane potential (P<0.01). While the intracellular ROS content and apoptosis rate of Raji cells in DHA+IR group were increased significantly(P<0.01). In addition, compared with the other three groups, there was no significant difference in the expression of AKT, but the phosphorylation of AKT protein were significantly inhibited and the expression of Bcl-2 protein was markedly decreased. However, the expressions of Bax and Cleaved-Caspase-3 protein were markedly increased. CONCLUSIONS: DHA might activate the mitochondrial apoptotic signal via inhibiting phosphoinositide 3-kinase (PI3K/AKT) pathway and increase oxidative stress to enhance the radiosensitivity of Raji cells.

[Salinomycin Enhances the Apoptosis of T-cell Acute Lymphoblastic Leukemia Cell Line Jurkat Cells Induced by Vincristine].

OBJECTIVE: This study was aimed to investigate the effect of salinomycin combined with vincristine on the proliferation and apoptosis of Jurkat cells and its possible mechanisms. METHODS: The proliferation of Jurkat cells was examined by CKK-8 assay. Flow cytometry was used to assess cellular apoptosis. Levels of BCL-2, caspase-3, and caspase- 8 were measured by Western blot. RESULTS: The salinomycin or vincristine, either alone or in combination, inhibited the proliferation of Jurkat cells in a dose-dependent manner. Salinomycin combined with vincristine produced more obveous inhibition of cell proliferation than either compound used alone (P<0.05). Western blot analysis showed that the combined use of Sal and VCR reduced the expression of BCL-2 protein, and increased expression of caspase 3 and caspase 8 protein, more significantly. Furthermore, combination of Sal and VCR synergistally promoted apoptosis of the Jurkat cells (P<0.05). CONCLUSION: The combination of salinomycin and vincristine synergistically inhibits proliferation and promotes apoptosis of T-cell acute lymphoblastic leukemia Jurkat cells.

Effects of nicotine on proliferation and survival in human umbilical cord mesenchymal stem cells.

Cigarette smoking is known to have negative effects on tissue repair and healing. The aim of this study is to investigate the effects of nicotine in human umbilical cord mesenchymal stem cells (MSCs). After nicotine treatment, MSCs became pyknotic, vacuoles appeared in the cytoplasm and nucleus, and the nuclear boundary became fuzzy as observed using atomic force microscopy. Cell proliferation was inhibited in a dose-dependent manner (P < 0.05 for all concentrations). The proportion of apoptotic MSCs was significantly increased in a dose-dependent manner. The mitochondrial membrane potential was significantly decreased (P < 0.05). Nicotine-treated MSCs had a significantly higher G0/G1 ratio (P < 0.05). Peptide mass fingerprinting identified 27 proteins that were differentially expressed between MSCs with and without nicotine treatment. These nicotine exerted toxic effects on MSCs are likely related, at least in part, to the altered expression of multiple proteins that are essential to the health and proliferation of these cells.

Combined transfection of Bcl-2 siRNA and miR-15a oligonucleotides enhanced methotrexate-induced apoptosis in Raji cells.

OBJECTIVE: B-cell lymphoma 2 (Bcl-2) is an important member of the Bcl-2 family of proteins that regulate the induction of apoptosis. This study aims to investigate whether Bcl-2 small interfering RNA (siRNA) combined with miR-15a oligonucleotides (ODN) could enhance methotrexate (MTX)-induced apoptosis in Raji cells. METHODS: Chemically synthesized miR-15a ODN and Bcl-2 siRNA were transfected in Raji cells by using a HiPerFect Transfection Reagent and then combined with MTX. Expression levels of Bcl-2 protein were detected by Western blot. Cell proliferation was determined by CCK8 assay. The rate of cell apoptosis was determined by Annexin V/PI double staining. The morphology of apoptotic cells was observed by Hoechst-33 258 staining. RESULTS: After the cells were transfected with miR-15a ODN combined with Bcl-2 siRNA, Bcl-2 protein levels were evidently decreased. CCK8 assay showed that cell proliferation was significantly decreased and was significantly lower in miR-15a ODN combined with Bcl-2 siRNA plus MTX group than in miR-15a ODN with methotrexate group, Bcl-2 siRNA with MTX group, and single MTX group (P<0.05). Hoechst 33258 staining revealed numerous apoptotic cells. AnnexinV/PI double staining showed that the apoptotic rates were (13.13±1.60)%, (34.47±2.96)%, (32.87±3.48)%, and (45.47±2.16)% in MTX, Bcl-2 siRNA plus MTX, miR-15a ODN plus MTX, and miR-15a ODN combined with Bcl-2 siRNA plus MTX groups, respectively. Among these groups, the apoptotic rate of miR-15a ODN combined with Bcl-2 siRNA plus MTX group was the highest; this apoptotic rate was also significantly different from that of miR-15a ODN or Bcl-2 siRNA plus MTX (P<0.05). CONCLUSIONS: Bcl-2 siRNA combined with miR-15a ODN could enhance MTX-induced apoptosis in Raji cells. Bcl-2 siRNA and miR-15a combined with MTX may be a useful approach to improve the treatment effects on lymphoma.

[Apoptosis and expression of Fas/FasL in tumor infiltrating dendritic cells in human endometrioid adenocarcinoma].

OBJECTIVE: To investigate apoptosis of tumor infiltrating dendritic cells (TIDC) and their expression of Fas/FasL (CD95/CD95L) in human endometrioid adenocarcinoma. METHODS: The apoptotic rate of TIDC was measured in 45 cases of endometrioid adenocarcinoma and 20 cases of normal endometrium tissues (control) by double-label immunohistochemistry using the monoclonal antibody S-100 protein and TUNEL technique. The expressions of Fas and FasL in TIDCs were detected using double-label immunohistochemistry and imaging analysis. RESULTS: The apoptotic rate of TIDCs in endometrioid adenocarcinoma were significantly higher than that in normal endormetrium [(13.02∓0.64)% vs (6.82∓0.53)%, P<0.05]. The expression levels of Fas in the TIDCs were significantly lower, whereas FasL expression significantly higher in endometrioid adenocarcinoma than in normal endormetrium (7.88∓1.05 vs 19.25∓3.03, P<0.05; 12.95∓2.25 vs 7.51∓1.14, P<0.05). CONCLUSION: Increased apoptosis of the TIDCs and abnormal expression of Fas/FasL in TIDCs in endometrioid adenocarcinoma may lead to tumor immune escape.

[Anti-aging effect of transplantation of mouse fetus-derived mesenchymal stem cells].

To determine the role of allogeneil graft of mesenchymal stem cells in mammalian longevity, mesenchymal stem cells were isolated from BALB/c mouse uterine-incision delivery fetus by two successive density gradient centrifugations, and then were purified and amplified by adherent culture. Identified P1 mesenchymal stem cells were injected (i.v.) through vena caudalis into the 15-month-old female BALB/c mice three times. The mice were evaluated with ultrasoundcardiogram, autopsy, score of cardiac, skin, lung, kidney, colon histopathology and serum total superoxide dismutase activity, maleic dialdehyde content, glutathione peroxidase activity. The results showed that after transplantation, the long-term surviving stem cells were found to be located in many organ tissues with in situ Y chromosomal hybridization dyeing. Median life span was increased in these animals after transplantation. Skin, cardiac, lung, kidney and colon pathology development were delayed. The retrogradation of heart function was attenuated, the increase of heart mass index (the mass of heart/the mass of the body), and serum maleic dialdehyde content, the decrease of spleen mass index (the mass of spleen/the mass of the body), serum total superoxide dismutase activity and glutathione peroxidase activity were reduced three months after transplantation (all P<0.05). These results support the idea that longevity can be enhanced by transplantation of mesenchymal stem cells and reinforce the hypothesis of mesenchymal stem cell as antiager.

Bcl-2 small hairpin RNAs enhance radiation-induced apoptosis in A549 cells.

Bcl-2, a prominent member of the family of proteins, is responsible for dys-regulation of apoptosis and resistance to chemotherapy and radiotherapy. This study investigated whether small hairpin RNA (shRNA) targeting Bcl-2 could render A549 cells more susceptible to gamma radiation-induced apoptosis. Recombinant Bcl-2 shRNAs expression vector were transfected into A549 cells with Lipofectamine 2000. Transfected cells were screened in 800 mg/ml G418 screening medium, and after stable transfection, silencing was examined. Expression of the Bcl-2 protein was assayed using Western blot in A549 cells. Inhibition of cell growth was assessed by a MTT assay. Apoptosis was determined by morphological observation and flow cytometry. Expression levels of Bcl-2 protein from A549 cells decreased after stable transfection with Bcl-2 shRNAs. No differences in Bcl-2 protein levels between control shRNA group and untreated cells were noted. After stable transfection with Bcl-2 shRNAs the viability of cells was less than after stable transfection with those with control shRNAs and untransfected A549, respectively (P<0.05). Control shRNA had no significant effect on growth of cells. Radiation significantly inhibited the growth of cells stably transfected with Bcl-2 shRNA (P<0.05). No difference in survival between the cells with control shRNA and untransfected cells was noted. Using Giemsa staining, cells stably transfected with Bcl-2 shRNA combined with radiation at 48 h displayed changes of apoptosis. After treatment with radiation apoptotic rates of the A549 cells stably transfected with Bcl-2 shRNA significantly increased (P<0.05), compared with the cells with control shRNA and untransfected cells. shRNAs against the Bcl-2 mRNA increases radiation-induced apoptosis in A549 cells.

[PI3K activity is associated with expression of neural specific genes in mouse fetal liver cells enhanced by butylated hydroxyanisole].

AIM: To study the mechanism of butylated hydroxyanisole-induced neural differentiation of fetal liver cells in vitro. METHODS: 14.5-day-old mouse fetal liver-derived cells were cultured, and were induced by 200 micromol/L butylated hydroxyanisole (BHA) combined with PI3K inhibitor LY294002 (20 micromol/L), and then were incubated in serum-free medium. Expression of genes in treated or untreated cells were assayed by Western blotting or RT-PCR. RESULTS: There was low level of neurofilament-L (NF-L) and brain factor-1 (BF-1) but no neurofilament-H (NF-H) and tyrosine hydroxylase (TH) in fetal liver cells. BHA promoted significantly expression of neuron-specific NF-L, NF-H, BF-1, and TH in fetal liver cells. NF-L mRNA increased 5.8 fold, NF-H mRNA 8.0 fold, BF-1 mRNA 2.68 fold, and TH mRNA 30 fold, respectively (all P < 0.01 vs untreated cells). NF-L protein increased 11.29 fold, NF-H 5.5 fold, BF-1 2.53 fold, TH 4.76 fold. Moreover, expression of these BHA-induced genes were inhibited by PI3K inhibitor LY294002. CONCLUSION: BHA induced neural differentiation of fetal liver cells through PI3K.

[Differentiation of human fetal liver CD34+ cells into neuronal cells induced by beta-ME and BHA in vitro].

AIM: To establish model of differentiation of fetal liver stem cells induced by beta-ME + BHA into neural cells in vitro; METHODS: CD34+ cells from naturally aborted human fetal liver were isolated with MACS Kit, and cultured in Dulbecco's modified Eagle's medium (DMEM) supplemented with 10% fetal bovine serum (FBS). After confluent more than 80%, the 5 passage cells were induced by 10(-3) mol/L beta-mercaptoethanol (beta-ME) and 2 x 10(-4) mol/L BHA for 24 hours, and washed with PBS, and then incubated in serum-free medium for 5 hours to 5 days. The characteristics of treated cells were assayed by immunocytochemistry staining analysis. RESULTS: Cells treated by beta-ME+ BHA exhibited neuronal phenotype, and expressed neuronal specific proteins such as nestin, NeuN, TrnJ-1, and NF-M, which were not found in control cells. Statistic analysis showed that 81% cells were NeuN-positive, 75% cells TuJ-1-positive, 47% cells NF-M-positive, 90% cells NSE-positive. CONCLUSION: beta-ME + BHA can induce human fetal liver CD34+ cells to produce neuronal specific antigens and proteins in vitro and become neuronal cells. CD34+ cells from human fetal liver possess potentials of differentiation into neural cells.

[CALM-AF10 fusion transcripts in primary leukemia with t(10;11) and in vitro chemotherapy sensitivity of leukemic cells with t(10;11)].

In order to determine the involvement of CALM-AF10 fusion transcripted in primary leukaemias with t(10;11) and its chemotherapy sensitivity in vitro, the AF10-CALM fusion transcripts were detected by reverse transcription-polymerase chain reaction (RT-PCR), and the chemotherapy sensitivity testing in vitro was undergone by MTT assay in five t(10;11) leukemia samples from patients with ALL, AML and lymphoblastic lymphoma. The results showed that five different-sized AF10-CALM product and four different-sized CALM-AF10 products were detected. The chemotherapy sensitivity of leukemic cells with t(10;11) in vitro to drugs is lower than that of leukemic cells without t(10;11). 3 out of 5 cases of t(10;11) leukemia were sensitive to chemotherapeutic drugs, while 31 out of 36 cases of leukemia without t(10;11) were sensitive at same condition. There were significant differences (P < 0.01), consistent with clinical features of patients. Apoptosis rate of leukemic cells with t(10;11) induced by chemotherapeutic drugs was lower than that of leukemic cells without t(10;11), (16.37 +/- 2.56)%, and (33.75 +/- 5.59)%, respectively (P < 0.01). It is concluded that the CALM-AF10 fusion transcripts are a common features and are involved in the pathogenesis of haematological malignancies with t(10;11), and are associated with a poor prognosis.

Probucol inhibits oxidized-low density lipoprotein-induced adhesion of monocytes to endothelial cells in vitro.

AIM: To investigate the mechanism by which probucol (PBC) affected adhesion of monocytes to human umbilical vein endothelial cells (HUVEC). METHODS: Effects of PBC on expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), P-selectin, a nd E-selectin in human umbilical vein endothelial cells were examined. Moreover, the inhibitory effect of PBC were compared with that of monoclonal antibodies (mAbs) to ICAM-1, VCAM-1, P-selectin, and E-select in on adhesion induced by oxidized-low density lipoprotein(Ox-LDL). RESULTS: PBC at 10 to 80 micromol/L inhibited Ox-LD L-induced adhesion index from 16.7 % to 7.0 % (P < 0.01) and Ox-LDL-induced expression of ICAM-1 (75 %) and P-selectin (72 %). mAbs to ICAM -1 or P-selectin, when used alone, could only slightly reduce the adhesion of monocyte to HUVEC. When both monoclonal antibodies were used in combination, the adhesion was markedly inhibited from 16.7 % to 11.3 % (P < 0.01), but the effect was still weaker than that of PBC (average 9.3 %). CONCLUSION: PBC exerts its inhibitory effect on the adhesion of monocyte to HUVEC by inhibiting the expression of ICAM-1 and P-selectin.