Objective:To explore the effects of simulated microgravity on carotid oxidative stress and anti-oxidative stress in rats by using a rat tail-suspension model to simulate the hemodynamic changes caused by microgravity.Methods:Twelve healthy adult male Sprague-Dawley rats were completely randomized into control group and simulated suspension group, with 6 rats in each group. The rats in control group were fed in standard laboratory environment and could move freely. The feeding environment of the simulated suspension group rats was the same as that of the control group, and the tail suspension was maintained for 4 weeks. The differentially expressed genes in carotid tissue were obtained by transcriptome sequencing, and analyzed by volcano plot, Venn diagram and heatmap. The differentially expressed genes were further analyzed by Gene Ontology and the Kyoto encyclopedia of genes and genomes. Dihydroethidium staining was used to detect the content of reactive oxygen species in rat carotid artery. Western blotting was used to detect the expression changes of pro-oxidative stress factor nicotinamide adenine dinucleotide phosphate oxidase 4 and anti-oxidative stress factors Kelch-like ECH-associated protein-1, nuclear factor-E2 related factor 2, heme oxygenase-1, and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase-1 in each group. The contents/activities of malondialdehyde, superoxide dismutase, catalase, reduced glutathione and oxidized glutathione in each group were detected using the thiobarbituric acid method, 4-[2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)tetrazol-2-ium-5-yl]benzene-1,3-disulfonate sodium method and colorimetry.Results:Compared with the rats in control group, the wet weight of soleus muscle and the ratio of the wet weight of soleus muscle to body weight in simulated suspension group rats were decreased ( t=19.98, 17.34, both P<0.001), and the differences were significant. Eighty differentially expressed genes related to oxidative stress were screened by transcriptional sequencing (52 up-regulated and 28 down-regulated), which were closely related to vascular remodeling pathways, including cyclic guanosine monophosphate-protein kinase G signal pathway, mitogen-activated protein kinase signal pathway, phosphoinositide 3-kinase-Akt signal pathway, protein processing in endoplasmic reticulum and lipid metabolism and atherosclerosis-related signal pathways. These genes were mainly involved in response to antioxidant defense, chaperone-mediated autophagy, stress fiber, contractile actin filament bundle, actin filament bundle, growth factor activity, chaperone binding and cytokine activity. Compared with the control group, the levels of reactive oxygen species ( t=3.83, P=0.028) and malondialdehyde ( t=8.75, P<0.001) in the simulated suspension group were significantly increased. The protein expression of nicotinamide adenine dinucleotide phosphate oxidase 4 ( t=11.49 , P<0.001) was significantly increased, with statistical significance. The activities of antioxidant stress related factors superoxide dismutase ( t=6.44, P=0.001), catalase ( t=6.83, P=0.001), and the ratio of reduced glutathione to oxidized glutathione ( t=3.46, P=0.003), and nuclear factor-E2 related factor 2 ( t=28.18, P<0.001), heme oxygenase-1 ( t=8.03, P<0.001), and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase-1 ( t=9.71, P<0.001) were significantly decreased, the protein expression of Kelch-like ECH-associated protein-1 ( t=5.06, P<0.001) was increased, and the differences were statistically significant. Conclusions:Simulated microgravity can enhance the level of carotid oxidative stress in rats, including promoting the expression of pro-oxidative stress-related factors and suppressing the activity of anti-oxidative stress pathways. Their combined action will lead to the oxidative stress injury of carotid arteries. This process may be one of the key mechanisms involved in the remodeling of arterial structure and function induced by simulated microgravity.

Objective:To explore the effects of simulated microgravity on carotid oxidative stress and anti-oxidative stress in rats by using a rat tail-suspension model to simulate the hemodynamic changes caused by microgravity.Methods:Twelve healthy adult male Sprague-Dawley rats were completely randomized into control group and simulated suspension group, with 6 rats in each group. The rats in control group were fed in standard laboratory environment and could move freely. The feeding environment of the simulated suspension group rats was the same as that of the control group, and the tail suspension was maintained for 4 weeks. The differentially expressed genes in carotid tissue were obtained by transcriptome sequencing, and analyzed by volcano plot, Venn diagram and heatmap. The differentially expressed genes were further analyzed by Gene Ontology and the Kyoto encyclopedia of genes and genomes. Dihydroethidium staining was used to detect the content of reactive oxygen species in rat carotid artery. Western blotting was used to detect the expression changes of pro-oxidative stress factor nicotinamide adenine dinucleotide phosphate oxidase 4 and anti-oxidative stress factors Kelch-like ECH-associated protein-1, nuclear factor-E2 related factor 2, heme oxygenase-1, and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase-1 in each group. The contents/activities of malondialdehyde, superoxide dismutase, catalase, reduced glutathione and oxidized glutathione in each group were detected using the thiobarbituric acid method, 4-[2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)tetrazol-2-ium-5-yl]benzene-1,3-disulfonate sodium method and colorimetry.Results:Compared with the rats in control group, the wet weight of soleus muscle and the ratio of the wet weight of soleus muscle to body weight in simulated suspension group rats were decreased ( t=19.98, 17.34, both P<0.001), and the differences were significant. Eighty differentially expressed genes related to oxidative stress were screened by transcriptional sequencing (52 up-regulated and 28 down-regulated), which were closely related to vascular remodeling pathways, including cyclic guanosine monophosphate-protein kinase G signal pathway, mitogen-activated protein kinase signal pathway, phosphoinositide 3-kinase-Akt signal pathway, protein processing in endoplasmic reticulum and lipid metabolism and atherosclerosis-related signal pathways. These genes were mainly involved in response to antioxidant defense, chaperone-mediated autophagy, stress fiber, contractile actin filament bundle, actin filament bundle, growth factor activity, chaperone binding and cytokine activity. Compared with the control group, the levels of reactive oxygen species ( t=3.83, P=0.028) and malondialdehyde ( t=8.75, P<0.001) in the simulated suspension group were significantly increased. The protein expression of nicotinamide adenine dinucleotide phosphate oxidase 4 ( t=11.49 , P<0.001) was significantly increased, with statistical significance. The activities of antioxidant stress related factors superoxide dismutase ( t=6.44, P=0.001), catalase ( t=6.83, P=0.001), and the ratio of reduced glutathione to oxidized glutathione ( t=3.46, P=0.003), and nuclear factor-E2 related factor 2 ( t=28.18, P<0.001), heme oxygenase-1 ( t=8.03, P<0.001), and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase-1 ( t=9.71, P<0.001) were significantly decreased, the protein expression of Kelch-like ECH-associated protein-1 ( t=5.06, P<0.001) was increased, and the differences were statistically significant. Conclusions:Simulated microgravity can enhance the level of carotid oxidative stress in rats, including promoting the expression of pro-oxidative stress-related factors and suppressing the activity of anti-oxidative stress pathways. Their combined action will lead to the oxidative stress injury of carotid arteries. This process may be one of the key mechanisms involved in the remodeling of arterial structure and function induced by simulated microgravity.

Esophageal cancer is the most common malignant tumors in the digestive system. The treatments include surgery, radiotherapy, chemotherapy, targeted therapy and immunotherapy. In order to prolong the survival time and reduce the recurrence rate, most of the patients with locally advanced esophageal cancer were treated with combined radiotherapy and chemotherapy. There are many ways of concurrent chemoradiotherapy, together with the application of molecular targeting and immune drugs in esophageal cancer, there are different modes of combined therapy, which are of great significance to improve clinical efficacy and treatment compliance. This article reviews the progress of concurrent chemoradiotherapy for esophageal cancer in recent years.

BACKGROUND:Recently, the effects of human umbilical cord mesenchymal stem cel s (hUCMSCs) and placenta-derived mesenchymal stem cel s (PDMSCs) on treatment of acute graft versus host disease (aGVHD) have been confirmed in some in vitro studies or animal models. But there are stil no reports comparing the therapeutic effects of these two cel types. OBJECTIVE:To compare the immunosuppressive function of hUCMSCs and PDMSCs in vitro or in a mouse aGVHD model. METHODS:(1) In vitro experiment. Human peripheral blood mononuclear cel s (PBMCs) were isolated and divided into four groups:PBMCs cultured alone, PBMCs stimulated with phytohaemagglutinin (PHA), PHA stimulated-PBMCs cocultured with hUCMSCs, PHA stimulated-PBMCs cocultured with PDMSCs. After 5 days, PBMCs proliferation and interferon-γlevel in cel supernatant were measured. (2) In vivo experiment. Fifty-seven BABL/C(H-2d) mice exposed to 8.5 Gy irradiation were randomly divided into five groups:only saline injection group, syngeneic bone marrow transplantation group, al ogeneic bone marrow transplantation group, aGVHD group, hUCMSCs treatment group, PDMSCs treatment group. The clinical aGVHD score, histopathology of skin, liver, and smal intestine, and survival time were analyzed at days 11, 14, 21 after transplantation. RESULTS AND CONCLUSION:(1) In vitro test:compared with the hUCMSCs, PDMSCs had stronger anti-inflammatory function. (2) In vivo test:The clinical scores on acute graft versus host disease were significantly lower in the hUCMSCs and PDMSCs treatment groups than that in the aGVHD group (P<0.05). The survival rates of mice were significantly increased in the hUCMSCs and PDMSCs treatment groups compared to the aGVHD group (P<0.05). Evident skin lesions were not found in al groups. Although smal intestine mucosal lesions were found in al groups, the damage level seemed similar. Notably, significant difference was found in the liver that multifocal necrosis and a large number of inflammatory cel s were seen in the aGVHD group, but less necrosis and inflammatory cel s in the hUCMSC and PDMSC treatment groups. In conclusion, hUCMSC and PDMSC are comparably effective in the treatment of aGVHD in mice.

BACKGROUND: Imatinib has a significant pro-apoptosis effect on chronic myelogenous leukemia (CML), but there are still some patients being resistant to it. Human umbilical cord mesenchymal stem cells (hUC-MSCs) affect the apoptosis of a variety of hematologic malignancies. However, the impacts of hUC-MSCs on the apoptosis of CML cells induced by imatinib remain unclear.OBJECTIVE: To investigate whether hUC-MSCs have an influence on the apoptosis of K562 cells induced by imatinib and to reveal the possible underlying mechanism.METHODS: K562 cells were cultured with hUC-MSCs or/and imatinib. Cellular apoptosis was measured with Annexin-V and PI staining by flow cytometry analysis. The protein expressions of Bax, Bcl-2, caspase-3, caspase-9 and cleaved-PARP in K562 cells were detected by western blot assay. Pan-caspase inhibitor Z-VAD-FMK was used to block apoptosis in each group, and during this process the effect of caspase apoptosis signaling pathway was detected.RESULTS AND CONCLUSION: The apoptosis of K562 cells was enhanced, when imatinib was combined with hUC-MSCs. Western blot analysis showed that the expression of pro-apoptotic protein Bax was enhenced and the expression of anti-apoptotic protein Bcl-2 was suppressed. Furthermore, the cleaved forms of caspase-9, caspase-3 and PARP in K562 cell were higher in the hUC-MSCs+imatinib group than in the imatinib group. The apoptosis of K562 cells induced by the hUC-MSCs combined with imatinib was significantly inhibited by Z-VAD-FMK. In conclusion, these findings indicate that hUC-MSCs can enhance imatinib-induced apoptosis of K562 cells by activating caspase apoptosis signaling pathway.

BACKGROUND: Mesenchymal stem cells (MSCs) are an important component of the in vivo microenvironment and act on multiple biological behaviors of tumor cells. The potential clinical value of MSCs has become an issue of concern in recent years.OBJECTIVE: To investigate the gene expression profiles of acute promyelocytic leukemia (APL) cell line NB4 treated with umbilical cord-derived MSCs (UC-MSCs) using cDNA microarray.METHODS: In vitro co-culture system was constructed, and then cellular proliferation, apoptosis and differentiation status of NB4 cells treated with UC-MSCs were evaluated. Two cDNA probes were prepared through reverse transcription from mRNA of NB4 cells treated with or without UC-MSCs. The probes were labeled with fluorescence dyes individually, hybridized with cDNA microarray, and their fluorescent intensities were scanned. The genes were screened through the analysis of the difference in two gene expression profiles.RESULTS AND CONCLUSION: UC-MSCs promoted the proliferation and differentiation, while reduced the apoptosis of NB4 cells. The analysis of gene expression profiles indicated that after co-culture with UC-MSCs, 530 genes were up-regulated and 53 genes were down-regulated. Accordingly, specific gene function and pathway signaling related were also regulated to some extent. Overall, UC-MSCs influence can major biological behaviors of NB4 cells by changing expression of a large amount of genes, gene-related function and multiple intracellular signaling pathways.

BACKGROUND:There are various methodstoinduceadipogenic differentiation ofbone marrow mesenchymal stem cels, and the main componentfor adipogenic induction isindomethacin or rosiglitazone. However, there is a lack of comparative studyonthe induction efficiency and mechanism among these methods.
OBJECTIVE:Tocompare the adipogenic responses ofhuman bone marrow mesenchymal stem celsto different induction methods, and to analyze the mechanismunderlyingdifferent induction efficiency.
METHODS:After isolation and purification,the adipogenic abilitiesof human bone marrow mesenchymal stem cels in threedifferentculture systemswere comparedby oil red O staining and lipogenic geneassay. At 0, 1, 3 and 7 days of adipogenensis, mRNA expressionsof PPARγ, C/EBPα, Adiponectin and Leptin were detected.At7 daysofadipogenensis, protein expressionsof PPARγ and C/EBPβ were detectedby western blot assay,andeffects ofDIMIversusDIMRonphosphorylationofPPARγatSer273were compared.
RESULTS AND CONCLUSION:Findings from oil red O staining andreal-time PCRshowedthat DIMR significantlyinducedadipogenicdifferentiation of bonemarrow mesenchymal stem cels compared with DIM and DIMI at 7 daysofinduction. Western blot showed thattheprotein expressionsof PPARγ and C/EBPβ in the DIMIgroupwere significantly higher than those in the DIMRand DIM at 7days ofinduction. In addition, the ratio ofPPARγphosphorylation atSer273was lowerin the DIMR group thantheDIMI group.To conclude,DIMR has the most potential to induce early adipogenesis ofhumanbone marrow mesenchymal stem cels by weakening the phosphorylationof PPARγ-Ser273.

BACKGROUND:There are abundant cel populations in the placenta that attracts more and more attentions because of high content of CD34+cel s. It is expected to become a new source of hematopoietic stem cel s for the treatment of hematologic diseases and other malignant diseases.
OBJECTIVE:To investigate the amount of cel s derived from placenta, their colony forming ability, and their chimerism analysis.
METHODS:Five placentas obtained from five healthy ful-term cesarean women were treated with perfusion method and tissue digestion for the cel col ection. Flow cytometry was used to detect the proportion of CD34+cel s in the placenta and cord blood, fol owed by the culture of cel colonies as wel as regular observation of cel morphology and counting. PCR amplification with sequence-specific primers and sequence-specific oligonucleotide probes were used to examine HLA type of placenta, umbilical cord blood, and maternal peripheral blood;Short tandem repeat PCR was used for chimerism analysis.
RESULTS AND CONCLUSION:There were more CD34+cel s in the placenta than in the umbilical cord blood. The placenta had good ability to form multiple colonies in vitro, and there were maternal source components in the placenta. It is concluded that the amount of cel s in the placenta and their biological functions exhibit the potential use of placenta as a new source of hematopoietic stem cel s.

Objective To investigate the influences of imatinib on Survivin gene expression in bcr-abl-transformed leukemia cells.Methods Firstly,PCR and Western blot were carried out to detected Survivin expression with imatinib treatment in 32Dcl3 and 32D-bcr-abl cell lines.Then the luciferase reporter plasmids containing human Survivin promoter as well as its deletion and site-directed mutation were constructed to identify the essential responsive elements for suppressing Survivin promoter activity by imatinib.Chromatin immunoprecipitation was performed to confirm the binding of c-myc to Survivin promoter.10058-F4,a small molecule c-myc inhibitor,was used to disrupt c-myc activity and evaluate its anti-leukemic effect combined with imatinib.Results Both of mRNA and protein level of Survivin in bcr-abl-transformed cells were downregulated upon imatinib treatment.The decrease of Survivin expression was controlled at the transcriptional level through a mechanism in which imatinib repressed survivin promoter activity by disturbing the interaction between c-myc and E-box elements.Interruption of c-myc activity by 10058-F4 exerted an anti-leukemia effect with enhancing the sensibility of K562/G01 cells to imatinib.Conclusion Imatinib down-regulates Survivin expression through c-myc-mediated transcription and interference with c-myc might be a potential utility for treatment of imatinib resistant leukemia.