红景天抑制人脐静脉内皮细胞生长的初步研究

目的:利用体外培养人脐静脉内皮细胞,观察中药红景天对细胞生长的影响,初步探讨急、慢性高原病患者服用中药红景天防治高原病及改善症状等的作用机制。方法:培养人脐静脉内皮细胞EVC-304,设对照组与加药组,加药组分别加入不同浓度的红景天,培养3d后计数。加药组及对照组细胞用瑞氏染料染色并拍照。收集细胞以流式细胞术检测细胞周期。结果:对照组细胞形态正常,成梭形,排列紧密,分散均匀。加药组细胞数量明显减少,细胞皱缩,聚集成团,形态各异。流式细胞术检测显示加药组G1期细胞含量增多,S期细胞减少。结论:红景天具有抑制血管内皮细胞生长的作用,可能是通过抑制细胞的增殖来抑制内皮细胞生长。抑制血管内皮细胞生长对于阻止血管内膜增生,防止形成肺动脉高压,降低慢性高原病发病率具有实际应用意义。     

The influence of physiological matrix conditions on permanent culture of induced pluripotent stem cell-derived cardiomyocytes

Cardiomyocytes (CMs) from induced pluripotent stem (iPS) cells mark an important achievement in the development of in vitro pharmacological, toxicological and developmental assays and in the establishment of protocols for cardiac cell replacement therapy. Using CMs generated from murine embryonic stem cells and iPS cells we found increased cell–matrix interaction and more matured embryoid body (EB) structures in iPS cell-derived EBs. However, neither suspension-culture in form of purified cardiac clusters nor adherence-culture on traditional cell culture plastic allowed for extended culture of CMs. CMs grown for five weeks on polystyrene exhibit signs of massive mechanical stress as indicated by α-smooth muscle actin expression and loss of sarcomere integrity. Hydrogels from polyacrylamide allow adapting of the matrix stiffness to that of cardiac tissue. We were able to eliminate the bottleneck of low cell adhesion using 2,5-Dioxopyrrolidin-1-yl-6-acrylamidohexanoate as a crosslinker to immobilize matrix proteins on the gels surface. Finally we present an easy method to generate polyacrylamide gels with a physiological Young's modulus of 55 kPa and defined surface ligand, facilitating the culture of murine and human iPS-CMs, removing excess mechanical stresses and reducing the risk of tissue culture artifacts exerted by stiff substrates.     

Vascular endothelial growth factor mRNA expression can be a marker for response to antiviral treatment of HCV

Angiogenesis has a significant pathogenic role in liver damage-associated hepatitis C virus infection. We evaluated whether chronic hepatitis C (CHC) is associated with elevated levels of angiogenesis marker (vascular endothelial growth factor) and whether it is modulated by therapy. Vascular endothelial growth factor (VEGF) mRNA was determined in the 36 CHC patients included in this study before therapy and 12 weeks after receiving antiviral combination therapy, pegylated interferon alpha-2b plus ribavirin, compared to 20 healthy controls. CHC patients showed elevated baseline VEGF level before and during treatment, but it was decreased in responder group, indicating a shift toward an “anti-angiogenic” process in CHC patients. In conclusion, this suggests that VEGF mRNA level could be useful as non-invasive, base markers of response to therapy.     

Susceptibility to severe Streptococcal sepsis: use of a large set of isogenic mouse lines to study genetic and environmental factors

Variation in responses to pathogens is influenced by exposure history, environment and the host's genetic status. We recently demonstrated that human leukocyte antigen class II allelic differences are a major determinant of the severity of invasive group A streptococcal (GAS) sepsis in humans. While in-depth controlled molecular studies on populations of genetically well-characterized humans are not feasible, it is now possible to exploit genetically diverse panels of recombinant inbred BXD mice to define genetic and environmental risk factors. Our goal in this study was to standardize the model and identify genetic and nongenetic covariates influencing invasive infection outcomes. Despite having common ancestors, the various BXD strains (n strains=33, n individuals=445) showed marked differences in survival. Mice from all strains developed bacteremia but exhibited considerable differences in disease severity, bacterial dissemination and mortality rates. Bacteremia and survival showed the expected negative correlation. Among nongenetic factors, age -- but not sex or weight -- was a significant predictor of survival (P=0.0005). To minimize nongenetic variability, we limited further analyses to mice aged 40-120 days and calculated a corrected relative survival index that reflects the number of days an animal survived post-infection normalized to all significant covariates. Genetic background (strain) was the most significant factor determining susceptibility (P< or =0.0001), thus underscoring the strong effect of host genetic variation in determining susceptibility to severe GAS sepsis. This model offers powerful unbiased forward genetics to map specific quantitative trait loci and networks of pathways modulating the severity of GAS sepsis.     

Mouse and human CD8+ CD28low regulatory T lymphocytes differentiate in the thymus

Regulatory T (Treg) lymphocytes play a central role in the control of immune responses and so maintain immune tolerance and homeostasis. In mice, expression of the CD8 co‐receptor and low levels of the co‐stimulatory molecule CD28 characterizes a Treg cell population that exerts potent suppressive function in vitro and efficiently controls experimental immunopathology in vivo. It has remained unclear if CD8⁺ CD28^low Treg cells develop in the thymus or represent a population of chronically activated conventional T cells differentiating into Treg cells in the periphery, as suggested by their CD28^low phenotype. We demonstrate that functional CD8⁺ CD28^low Treg cells are present in the thymus and that these cells develop locally and are not recirculating from the periphery. Differentiation of CD8⁺ CD28^low Treg cells requires MHC class I expression on radioresistant but not on haematopoietic thymic stromal cells. In contrast to other Treg cells, CD8⁺ CD28^low Treg cells develop simultaneously with CD8⁺ CD28^high conventional T cells. We also identified a novel homologous naive CD8⁺ CD28^low T‐cell population with immunosuppressive properties in human blood and thymus. Combined, our data demonstrate that CD8⁺ CD28^low cells can develop in the thymus of mice and suggest that the same is true in humans.     

Multiple intra-familial transmission patterns of hepatitis B virus genotype D in north-eastern Egypt

The transmission rate of intra‐familial hepatitis B virus (HBV) and mode of transmission were investigated in north eastern Egypt. HBV infection was investigated serologically and confirmed by molecular evolutionary analysis in family members (N = 230) of 55 chronic hepatitis B carriers (index cases). Hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti‐HBc) prevalence was 12.2% and 23% among family members, respectively. HBsAg carriers were prevalent in the age groups; <10 (16.2%) and 21–30 years (23.3%). The prevalence of HBsAg was significantly higher in the family members of females (19.2%) than males (8.6%) index cases (P = 0.031). HBsAg and anti‐HBc seropositive rates were higher significantly in the offspring of females (23%, 29.8%) than those of the males index cases (4.3%, 9.8%) (P = 0.001, 0.003), as well as higher in the offspring of an infected mother (26.5, 31.8%) than those of an infected father (4.7%, 10.5%) (P = 0.0006, 0.009). No significant difference was found in HBsAg seropositive rates between vaccinated (10.6%) and unvaccinated family members (14.8%). Phylogenetic analysis of the preS2 and S regions of HBV genome showed that the HBV isolates were of subgenotype D1 in nine index cases and 14 family members. HBV familial transmission was confirmed in five of six families with three transmission patterns; maternal, paternal, and sexual. It is concluded that multiple intra‐familial transmission routes of HBV genotype D were determined; including maternal, paternal and horizontal. Universal HBV vaccination should be modified by including the first dose at birth with (HBIG) administration to the newborn of mothers infected with HBV. J. Med. Virol. 84:587–595, 2012. © 2011 Wiley Periodicals, Inc.     

PCT、CRP动力学评估脓毒血症预后及诊断意义的研究

目的 观察血清降钙素原(PCT)、C反应蛋白(CRP)及其动力学变化,评估其在严重脓毒症/感染性休克患者的诊断及预后价值.方法 本研究采用回顾性分析方法,2014年9月1日至2016年4月30日选择184例ICU中被诊断为严重脓毒症/感染性休克疾病患者,检测入院时血清PCT、CRP水平和治疗后第2,第3和第5天的PCT、CRP水平.结果 通过△PCT、△CRP评估PCT、CRP的动力学在存活者与死亡组中有显著性统计学意(△PCT2/0,P=0.0001;△PCT3/0,P=0.0001;△PCT5/0,P=0.0001;△CRP2/0,P=0.0069;△CRP3/0,P=0.0001;△CRP5/0,P=0.0001),在严重脓毒症和感染性休克组中也存在显著差异(PCT5,P=0.007;△PCT5/0,P=0.007).受试者工作特征曲线(ROC)模型显示,△PCT3/0(AUC=0.721)、△PCT5/0(AUC=0.77)、△CRP5/0(AUC=0.766)水平判断严重脓毒症/感染性休克患者预后有较好的临床意义.△PCT5/0 (0.619)对严重脓毒症或感染性休克有一定的辅助诊断效果,其在ROC曲线上灵敏度、特异性均较高的临界点为0.624,所以,以第5天的血清△PCT5/0水平＞0.624可作为预测感染性休克的临界点.结论 血清中PCT、CRP对严重脓毒症/感染性休克早期有较好的临床诊断及预后价值,其动力学研究可以提高对严重脓毒症/感染性休克诊断及预后评估的敏感性及准确性.     

Myeloid-derived suppressor cells and regulatory T cells share common immunoregulatory pathways-related microRNAs that are dysregulated by acute lymphoblastic leukemia and chemotherapy

BackgroundRelapse remains a critical challenge in children with acute lymphoblastic leukemia (ALL). The emergence of immunoregulatory cells, including myeloid-derived suppressor cells (MDSCs), and T regulatory (T_reg) cells, has been considered one potential mechanism of relapse in children with ALL.AimThis study aimed to address the microRNAs (miRNAs) related to MDSCs and T_reg cells and to explore their targeted immunoregulatory pathways.MethodsAffymetrix microarray was used for global miRNA profiling in B-ALL pediatric patients before, during, and after induction of chemotherapy. Bioinformatics analysis was performed on MDSCs and T_reg cells-related dysregulated miRNAs, and miR-Pathway analysis was performed to explore their targeted immunoregulatory pathways.Results516 miRNAs were dysregulated in ALL patients as compared to the healthy donor. Among them, 13 miRNAs and 8 miRNAs related to MDSCs and T_reg cells, respectively, were common in all patients. Besides, 12 miRNAs were shared between MDSCs and T_reg cells; 4 of them were common in all patients. Four immune-related pathways; TNF, TGF-β, FoxO, and Hippo were found implicated.ConclusionOur pilot study concluded certain miRNAs related to MDSCs and T_reg cells, these miRNAs were linked to immunoregulatory pathways. Our results open avenues for testing those miRNA as molecular biomarkers for the immunosuppressive tumor microenvironment.