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.

Hypoxia-mimetic agents inhibit proliferation and alter the morphology of human umbilical cord-derived mesenchymal stem cells.

BACKGROUND: The therapeutic efficacy of human mesenchymal stem cells (hMSCs) for the treatment of hypoxic-ischemic diseases is closely related to level of hypoxia in the damaged tissues. To elucidate the potential therapeutic applications and limitations of hMSCs derived from human umbilical cords, the effects of hypoxia on the morphology and proliferation of hMSCs were analyzed. RESULTS: After treatment with DFO and CoCl2, hMSCs were elongated, and adjacent cells were no longer in close contact. In addition, vacuole-like structures were observed within the cytoplasm; the rough endoplasmic reticulum expanded, and expanded ridges were observed in mitochondria. In addition, DFO and CoCl2 treatments for 48 h significantly inhibited hMSCs proliferation in a concentration-dependent manner (P < 0.05). This treatment also increased the number of cells in G0/G1 phase and decreased those in G2/S/M phase. CONCLUSIONS: The hypoxia-mimetic agents, DFO and CoCl2, alter umbilical cord-derived hMSCs morphology and inhibit their proliferation through influencing the cell cycle.

[p38 mitogen-activated protein kinase inhibitor suppresses the expression of pro-inflammatory cytokines in liver from brain dead rats].

OBJECTIVE: To observe the suppressive effect on the expression of pro-inflammatory cytokines in liver from brain dead (BD) rats through inhibition of p38 mitogen-activated protein kinase (MAPK) signaling pathway by SB203580. METHODS: A total of 30 male Wistar rats weighing from 180 to 200 g were randomly divided into 3 experimental groups: (1) BD group (n = 10): brain death was induced in rats; (2) BD+SB203580 group (n = 10): brain death was successfully induced and SB203580 (10 mg/kg) was given through dorsal vein of penis. After brain death artificial ventilation was maintained for 6 hours and only those with mean arterial blood pressure more than 80 mm Hg (1 mm Hg = 0.133 kPa) were accepted as BD donors. (3) Control group (n = 10): living healthy rats. The expressions of TNFalpha and IL-1beta mRNA in liver tissues were analyzed by RT-PCR and the protein expressions of TNFalpha, IL-1beta and phosphorylated p38MAPK were detected by Western blot. RESULTS: The phosphorylated p38MAPK detected in the liver in BD group was significantly increased compared with the control group (q = 172.53, P < 0.01), and the expressions of TNFalpha and IL-1beta mRNA and proteins in liver were also significantly increased in BD group compared with the control group (q = 123.99, 135.35, 243.09 and 192.23, respectively, P < 0.01). The phosphorylated p38MAPK was decreased in BD+SB203580 group and significantly decreased compared with the BD group (q = 63.90, P is less than 0.05), but higher than that in control group (q = 108.63, P < 0.01). The expressions of TNFalpha and IL-1beta mRNA and proteins in liver were significantly decreased in BD+SB203580 group compared with the BD group (q = 55.11, 98.13, 61.03 and 50.85, respectively, P < 0.01), but higher than that in control group (q = 68.89, 37.22, 182.06 and 141.38, respectively, P < 0.01). SB203580 can suppress the expression of pro-inflammatory cytokines in the liver of brain dead rats through the inhibition of p38MAPK signaling pathway which may reduce the immunogenicity of donor livers.

[Reactive oxygen species and mitochondrial membrane potential changes in leukemia cells during 6-gingerol induced apoptosis].

OBJECTIVE: To observe the effects of 6-gingerol on reactive oxygen species (ROS) and mitochondrial membrane potential(deltapsim) of chronic myeloid leukemia K562 cells and human acute T lymphoblastic leukemia MOLT4 cells, to investigate the role of mitochondrial pathway in the signal transduction of leukemia cell. METHODS: With different concentrations of 6-gingerol treatment, using 2,7-dichloro fluoresceinciactate (DCFH-DA) as ROS probe, rhodamine-123 as deltapsim probe, the levels of ROS and deltapsim of K562 cells and MOLT4 cells were tested by flow cytomentry. RESULTS: After treated with 6-gingerol, the ROS levels of K562 cells were significantly higher than control group (P < 0.01), while the deltapsim were significantly lower than control group (P < 0.01), and the ROS levels of MOLT4 cells were significantly higher than control group (P < 0.05). CONCLUSIONS: 6-gingerol can significantly increase ROS levels of K562 cells and MOLT4 cells, decrease deltapsim of K562 cells,induce apoptosis of leukemia cells by mitochondrial pathway.

[Comparative protein analysis of K562 cell apoptosis induced by 6-gingerol].

OBJECTIVE: To establish two-dimensional electrophoresis (2-DE) pattern for proteome analysis on K562 cells before and after treatment with 6-gingerol, and mass-spectrometry was applied to identify and analyze the differentially expressed proteins. METHODS: K562 cells were treated with 6-gingerol. Cell proliferation was analyzed by CCK-8 assay. Total protein of K562 cells was extracted by 2D-DIGE and then imaged by SDS gel scanning. The differentially expressed proteins were identified using Imagine Master 2D Platinum 6.0 software and functionally classified by MALDI and MALDI-TOF MS. RESULTS: 6-gingerol could significantly inhibit K562 cells proliferation and the efficacy was concentration and dose-dependent. After being treated for 24, 48, 72 h, IC50 was 22.86, 15.75, 11.18 microg/mL, respectively. 42 differentially expressed proteins were identified, including 19 up-regulated expressed proteins and 10 down-regulated expressed proteins. CONCLUSION: Proteomic technique can be used to screen multiple proteins associate with the anti-leukemia effect of 6-gingerol, involving some important proteins related to oxidative stress, cell cycle regulation, apoptosis signal transduction, biosynthesis and glycometabolism.

[Inhibitory effects of pretreatment with Buyanghuanwu decoction on inflammatory cytokine expressions in the kidneys of rats after induction of brain death].

OBJECTIVE: To observe the inhibitiory effects of pretreatment with Buyanghuanwu decoction (BYHWT) on inflammatory cytokine expressions in the kidneys and the level of reactive oxygen species (ROS) by peripheral blood neutrophils of rats after induction of brain death (BD), and to investigate the effect of BYHWT on the improvement of kidney quality from BD donor. METHODS: 30 male Wistar rats were randomly divided into 3 groups: control group, BD model group and BYHWT group. 6 hours after successful onset of brain death,only the BD rats whose mean arterial blood pressure were higher than 80 mmHg were accepted as donors. Kidneys were harvested and peripheral blood was taken from BD rats. RT-PCR was used to detect the expressions of TNF-a and IL-lpfl mRNA. Western blot was adopted to analyze the expressions of both TNF-alpha and IL-lp protein,and the expression of phosphorylated p38 mitogen-activated protein kinase (p-p38MAPK). Reactive oxygen species( ROS) in the peripheral blood neutrophils were labeled with CM-H2DCFDA and then detected with Flow Cytometry. RESULTS: The expressions of both TNF-alpha and IL-1beta mRNA and protein, and the p-p38MAPK proteins all significantly increased in BD group compared with control group (P < 0.01). However, those in BYHWT group statistically decreased compared with BD group (P < 0.05), but they significantly increased in comparison with control group (P < 0.01). There was a close relation between the expression of p-p38MAPK protein and the expressions of both TNF-a and IL-1beta mRNA and protein. ROS level significantly increased in BD group (P < 0.05 ), whereas it significantly decreased in BYHWT group (P < 0.05). There was no statistically significant difference between BYHWT group and control group (P > 0.05). CONCLUSION: Pretreatment of the rats with BYHWT prior to the induction of rat brain death, can significantly suppress the expressions of inflammatory cytokines and ROS level in the kidneys of rats from BD. It might be related to the blockage of key target points in p38MAPK signaling pathway. Therefore pretreatment with BYHWT could hopefully be an ideal way to improve the quality of kidneys from brain dead donors prior to transplantation.

Identification of altered microRNAs in retinas of mice with oxygen-induced retinopathy.

AIM: To identify disease-related miRNAs in retinas of mice with oxygen-induced retinopathy (OIR), and to explore their potential roles in retinal pathological neovascularization. METHODS: The retinal miRNA expression profile in mice with OIR and room air controls at postnatal day 17 (P17) were determined through miRNA microarray analysis. Several miRNAs were significantly up- and down-regulated in retinas of mice with OIR compared to controls by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Two databases including Targetscan7.1 and MirdbV5 were used to predict target genes that associated with those significantly altered miRNAs in retinas of mice with OIR. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were also conducted to identify possible biological functions of the target genes. RESULTS: In comparison with room air controls, 3 and 8 miRNAs were significantly up- and down-regulated, respectively, in retinas of mice with OIR. The qRT-PCR data confirmed that mmu-miR-350-3p and mmu-miR-202-3p were significantly up-regulated, while mmu-miR-711 and mmu-miR-30c-1-3p were significantly down-regulated in mice with OIR compared to controls. GO analysis demonstrated that the identified target genes were related to functions such as cellular macromolecule metabolic process. KEGG pathway analysis showed a group of pathways, such as Wnt signaling pathway, transcriptional misregulation in cancer, Mucin type O-glycan biosynthesis, and mitogen-activated protein kinase (MAPK) signaling pathway might be involved in pathological process of retinal neovascularization. CONCLUSION: Our findings suggest that the differentially expressed miRNAs in retinas of mice with OIR might provide potential therapeutic targets for treating retinal neovascularization.

Attenuation of periostin in retinal Müller glia by TNF-α and IFN-γ.

AIM: To investigate the regulation and mechanisms of periostin expression in retinal Müller glia, and to explore the relevance to retinal neovascularization. METHODS: The oxygen-induced retinopathy (OIR) mouse model and the human Moorfield/Institute of Ophthalmology-Müller 1 (MIO-M1) cell line were used in the study. Immunofluorescence staining was used to determine the distribution and expression of periostin and a Müller glial cell marker glutamine synthetase (GS). Cytokines TNF-α and IFN-γ were added to stimulate the MIO-M1 cells. ShRNA was used to knockdown periostin expression in MIO-M1 cells. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was conducted to assess the mRNA expression of periostin. RESULTS: Immunofluorescence staining showed that periostin was expressed by MIO-M1 Müller glia. GS-positive Müller glia and periostin increased in OIR retinas, and were partially overlaid. The stimulation of TNF-α and IFN-γ reduced the mRNA expression of periostin significantly and dose-dependently in MIO-M1 cells. Knockdown of periostin reduced mRNA expression of vascular endothelial growth factor A (VEGFA) in MIO-M1 cells, while VEGFA expression was not changed in periostin knock-out OIR retinas. CONCLUSION: Müller glia could be one of the main sources of periostin in the retina, and might contribute to the pathogenesis of retinal neovascularization. Proinflammatory cytokines TNF-α and IFN-γ attenuate the periostin expression in retinal Müller glia, which provides a potential and novel method in treating retinal neovascular diseases.

The role of microglia in the progression of glaucomatous neurodegeneration- a review.

Glaucoma is a serious leading cause of irreversible blindness worldwide. Reducing intraocular pressure (IOP) does not always stop glaucomatous neurodegeneration and the optic nerve may continue to be damaged in the normal IOP. Microglial activity has been recognized to play essential roles in pathogenesis of the central nervous system (CNS) as well as retinal ganglion cell (RGC) survival. The relationship between the neurodegeneration and the microglia cells in glaucoma is very complicated and still remains unclear. In the present review, we summarize the recent studies of mechanisms of microglia in glaucoma neurodegeneration, which might provide new ways to treat glaucoma.

[Low dose heparin for the prevention of hepatic veno-occlusive disease after allogeneic hematopoietic stem cell transplantation].

OBJECTIVE: To explore the safety and efficacy of low dose heparin for the prevention of hepatic veno-occlusive disease (VOD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) conditioned with busulfan and cyclophosphamide (BU-CY2) and the ideal time frame of the heparin administration. METHODS: From April 1997 to December 2005, 134 patients (75 male, 59 female; median age 25 years old) were transplanted in our bone marrow transplantation unit. All patients were conditioned with BU-CY2 or busulfan-based regimen and scheduled to receive a continuous injection of heparin at a dose of 100 IUxkg-1xd-1. The patients were divided into different groups: 87 patients received related donor transplantation and 47 patients unrelated donor transplantation; 40 patients had abnormal liver function prior to transplantation and the remaining 94 patients normal liver function; 68 patients received heparin from day -7 to day +21 post HSCT and the other 66 patients from day -7 to day +14. RESULTS: All 134 patients had sustained engraftment. The median time for neutrophils to reach 0.5 x 10(9)/L and for platelets to reach 20x10(9)/L were 12 days (range 9-28) and 20 days (range 6-65), respectively. The disease-free survival at day +100 for leukemia patients was 82.2% (97/118). None of 134 patients developed VOD (0%), including 10 patients with class 3 thalassemia major. The incidence and severity of clinical bleeding events in 15 patients monitored with prothrombin time and activated partial thromboplastin time is comparable with those not monitored. CONCLUSIONS: It is suggested that low dose heparin alone is effective and safe for the prophylaxis of VOD following allo-HSCT conditioned with BU-CY regimen. Shortening the duration of administering heparin from -7 d to +21 d to -7 d to +14 d does not affect the effectiveness of low dose heparin to prevent VOD.

[Effects of decitabine on proliferation and apoptosis of NB4 and K562 cells].

This study was aimed to investigate the effects of decitabine (DAC) on proliferation and apoptosis of leukemia NB4 and K562 cells. The proliferation inhibition of DAC on NB4 and K562 cells was detected by Trypan blue staining. After treatment of DAC at different concentrations, the changes of cell cycle and CD11b expression was determined by flow cytometry. The cell morphological changes were observed by Wright's staining. The DNA ladder was used to detect cell apoptosis. The results indicated that DAC significantly inhibited the proliferation of NB4 and K562 cells in dose-and time-dependent manner. The median inhibitory concentration (IC50) of DAC-treated NB4 and K562 cells for 72 h was 0.113 µmol/L and 0.138 µmol/L, respectively. After treating these two cell lines with DAC at different concentration for 72 h, the cell ratio in G0/G1 phase significantly increased, while the cell ratio in S phase obviously decreased in 0.15 µmol/L DAC group (P < 0.05). The expression levels of myeloid differentiation antigen CD11b of both cell lines significantly increased in contrast to the control group (P < 0.05). The cell morphology detected by Wright's staining displayed partial differentiation and apoptosis after treating NB4 and K562 cells with DAC for 48 h. Typical apoptotic DNA ladder was observed in 0.15 µmol/L DAC group at 48 h. It is concluded that DAC can inhibit NB4 and K562 cell proliferation, induce cell differentiation and apoptosis, but more obviously for NB4 cells.

[Differential proteomic analysis in human umbilical cord mesenchymal stem cells induced by cobalt chloride].

OBJECTIVE: To analyze the differential proteomics in human umbilical cord mesenchymal stem cells (MSC) induced by chemical hypoxia-mimetic agent cobalt chloride (CoCl(2)) by two-dimensional gel electrophoresis (2-DE) and mass-spectrometry. METHODS: 2-DE was performed to separate proteins from treated and untreated human umbilical cord MSC with CoCl(2). 2-DE images were analyzed by ImageMaster 2D Platinum software 6.0. The differential expressed proteins was identified by MALDI-TOF-MS. The differential proteins were classified based on their functions. RESULTS: 2-DE reference patterns of CoCl(2) treated human umbilical cord MSC were established. A total of twenty-six differential proteins were identified, of them eleven proteins were up-regulated and fifteen down-regulated. Their biological functions involved in carbohydrate metabolism, protein metabolism and modification, lipid metabolism, coenzyme and prosthetic group metabolism, cell cycle, immunity and defense, cell structure and motility, signal transduction, protein targeting and localization, neuronal activities, muscle contraction, etc. Peroxiredoxin1 (Prdx) was down-regulated, whereas alpha-enolase (ENO1) and vesicle amine transport protein 1 homolog (VAT1) up-regulated. CONCLUSION: The effects of hypoxia on human umbilical cord MSC were participated by multiple proteins and involved in multiple functional pathways.

Phosphoproteomic analysis of primary human multiple myeloma cells.

Multiple myeloma (MM) is a malignant disorder of differentiated B cells. Clonal expansion of the tumor results in the excessive production of monoclonal immunoglobulin (Ig) which is a diagnostic feature of this disease. Previous investigations have demonstrated the alteration of the ERK, jun kinase, STAT, and AKT kinase signaling cascades in MM cells, suggesting that deregulated phosphorylation may contribute to MM pathogenesis. However, systematic analysis of the phosphoproteome in MM cells has not been reported. Here, we described a large-scale phosphorylation analysis of primary MM cells. Using a separation strategy involving immunomagnetic bead-positive selection of MM cells, preparative SDS-PAGE for prefractionation, in-gel digestion with trypsin, and titanium dioxide enrichment of phosphopeptides, followed by LC-MS/MS analysis employing a hybrid LTQ-Orbitrap mass spectrometer, we were able to catalog a substantial portion of the phosphoproteins present in primary MM cells. This analysis led to the identification of 530 phosphorylation sites from 325 unique phosphopeptides corresponding to 260 proteins at false positive rate (FPR) of 1.3%. This dataset provides an important resource for future studies on phosphorylation and carcinogenesis analysis of multiple myeloma.

Proteomic and functional analyses reveal a dual molecular mechanism underlying arsenic-induced apoptosis in human multiple myeloma cells.

Multiple myeloma (MM) is an incurable plasma cell malignancy with a terminal phase marked by increased proliferation and resistance to therapy. Arsenic trioxide (ATO), an antitumor agent with a multifaceted mechanism of action, displayed clinical activity in patients with late-stage multiple myeloma. However, the precise mechanism(s) of action of ATO has not been completely elucidated. In the present study, we used proteomics to analyze the ATO-induced protein alterations in MM cell line U266 and then investigated the molecular pathways responsible for the anticancer actions of ATO. Several clusters of proteins altered in expression in U266 cells upon ATO treatment were identified, including down-regulated signal transduction proteins and ubiquitin/proteasome members, and up-regulated immunity and defense proteins. Significantly regulated 14-3-3zeta and heat shock proteins (HSPs) were selected for further functional studies. Overexpression of 14-3-3zeta in MM cells attenuated ATO-induced cell death, whereas RNAi-based 14-3-3zeta knock-down or the inhibition of HSP90 enhanced tumor cell sensitivity to the ATO induction. These observations implicate 14-3-3zeta and HSP90 as potential molecular targets for drug intervention of multiple myeloma and thus improve our understanding on the mechanisms of antitumor activity of ATO.

Comparative proteomic analysis to discover potential therapeutic targets in human multiple myeloma.

To clarify the molecular mechanisms that participate in the formation of multiple myeloma (MM) and to detect any tumor-related biomarkers, we performed proteomic analysis of cellular protein extracts from MM cells and normal plasma cells. Plasma cells from nine patients with newly diagnosed MM and nine healthy donors were purified by using anti-CD138 based immunomagnetic bead-positive selection. The protein profiles of purified MM and normal plasma cells were compared using 2-DE. We identified a total of 43 differentially expressed proteins, and confirmed with Western blotting six proteins. The altered proteins were analyzed using the software program Pathway Studio and the biological network can be accessed via (http://life-health.jnu.edu.cn/pathway/pathway.html). Further functional studies showed that annexin A1 knock down modestly induces lethality alone and potentiates the effects of dexamethasone on both dexamethasone-sensitive and dexamethasone-resistant MM cells. By correlating the proteomic data with these functional studies, the current results provide not only new insights into the pathogenesis of MM but also direct implications for the development of novel anti-MM therapeutic strategies and could lead to the discovery of potential therapeutic targets. Future molecular and functional studies would provide novel insights into the roles of these dysregulated proteins in the molecular etiology of MM.

[Study on clonal proliferation of TCR Vbeta subfamily T cells induced by AML-M(2a) cells in vivo and in vitro].

To observe the expression and clonal expansion of TCR Vbeta subfamily T cells induced by AML-M(2a) cells in vivo and in vitro, complementary determining region 3 (CDR3) of TCR beta with variable region genes was amplified by using RT-PCR in both peripheral blood mononuclear cells (PBMNC) and T cells from mixed lymphocyte and tumor culture (MLTC) from four AML-M(2a) patients. The positive products were further analyzed to identify the clonality of T cells by genescan. The results showed that the similarity distribution of TCR Vbeta subfamily T cells was found Vbeta in PBMNC and MLTC. One or two clonality expansions of T cells could be found in predominant TCR Vbeta subfamily T cells induced by A ML-M2a cells from 3 cases in vivo and in vitro. It was concluded that clonal expansion of TCR Vbeta subfamily T cells stimulated selectively by AML-M(2a) cells may be a specific immune response of patient's T cells to AML-M(2a) cells associated antigen. The clonal proliferation of TCR Vbeta subfamily T cells were affected somewhat by environmental difference in vivo and in vitro.