Estrogen treatment enhances mesenteric lymphatic contractility in rats after hemorrhagic shock

AIM To investigate the effects of 17β-estradiol （E2） treatment on the mesenteric lymphatic microcirculation and isolated lymphatic contractility in rats after hemorrhagic shock, and to explore the relationship between contractility and the difference between intra- and extracellular calcium ion concentrations （［Ca²⁺］） of lymphatic smooth muscle cells （LSMCs）. METHODS Male Wistar rats were divided into sham group, shock group and shock+E2 group. The rats were subjected to hemorrhage ［（40±2） mmHg for 90 min］ and resuscitation with or without subcutaneous injection of E2 （2 mg/kg）. After resuscitation for 3 h, the mesenteric lymphatic microcirculation in vivo was observed. Moreover, the isolated mesenteric microlymphatic rings were prepared for the observations of lymphatic contractility evaluated by the indexes including end-systolic diameter, end-diastolic diameter, contraction frequency （CF） and passive diameter. Meanwhile, the difference between intra- and extracellular ［Ca²⁺］ of LSMCs was recorded during lymphatic contraction. RESULTS Treatment with E2 significantly enhanced the CF, total contractile fraction and lymphatic dynamics index in vivo in the rats after hemorrhagic shock, and increased the CF, the fractional pump flow and the difference between intra- and extracellular ［Ca²⁺］ of LSMCs in isolated lymphatics from the shocked rats （P<0.05）. CONCLUSION Estrogen treatment enhances lymphatic contractility in rats after hemorrhagic shock, which is related to enhancement of difference between intra- and extracellular ［Ca²⁺］ of LSMCs.     

Physiological and pathological roles of mast cells in adipose tissue

Mast cells are important cells for the innate immunity that reside in tissues including adipose tissue and are involved in various physiological and pathological processes by producing a range of biological mediators. Adipose tissue not only acts as an energy depot and regulator of energy homeostasis that can deposit excess energy and dissipate energy through heat, but also is an active endocrine organ capable of producing hormones and adipokines. The dysfunction of adipose tissue is highly correlated with metabolic disorders, such as obesity, type 2 diabetes mellitus and so on. This review focuses on the physiological and pathological roles of mast cells in adipose tissue.     

Construction of mouse ESC line stably expressing Pdx1 by Tet-On system

AIM To construct the mouse embryonic stem cell （ESC） line with stable pancreatic and duodenal homeobox 1 （Pdx1） expression by Tet-On system, which may lay a foundation for further research on the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells. METHODS The Pdx1-overexpressing lentiviral vector with green fluorescent protein marker and puromycin resistance was constructed by Tet-On system and was used to infect the mouse ESC. The cells were divided into 3 groups： blank control group （ESC group）, empty lentivirus control group （PDX1^- ESC group） and Pdx1 lentivirus transfection group （PDX1⁺ ESC group）. Flow cytometry was used to detect the transfected cells after screening by doxycycline （DOX）. The function of Tet-On system and the expression of Pdx1 gene were detected. The transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were sorted by flow cytometry, and constructed ESC line with stable expression of Pdx1 and negative control ESC line were verified. RESULTS （1） The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group were 90.72% and 94.01% after screening by DOX, respectively. The positive rates of transfected cells in PDX1^- ESC group and PDX1⁺ ESC group was 97.84% and 98.13% after sorting by flow cytometry, respectively. （2） With DOX, green fluorescence was observed in PDX1^- ESC group and PDX1⁺ ESC group. The mRNA and protein expression of Pdx1 was significantly increased in PDX1⁺ ESC group （P<0.05）. Without DOX, no green fluorescence was observed in the cells of the 3 groups, and no significant difference in the mRNA and protein expression of Pdx1 was observed （P>0.05）. （3） After 3 months of cryopreservation, the cell lines still survived in resuscitation culture and were regulated by DOX. CONCLUSION Using Tet-On system, the mouse ESC line with inducible Pdx1 expression were successfully established and could be used as an effective cell model to research the differentiation of Pdx1⁺ definitive endoderm cells into pancreatic cells.     

寡齿新银鱼卵细胞粘丝的亚显微结构

经电镜扫描寡齿新银鱼的第Ⅳ时相，第Ⅴ时相卵母细胞和受卵的卵细胞粘丝，结果表明，卵细胞表面具从受精孔发生的１２根左右粘丝，此粘丝于受精孔处微弱弯曲，经侧部渐向受精孔相对处呈现很强扭曲或互相缠绕。卵细胞粘丝不仅出现在受精卵和第Ⅴ时相卵母细胞表面，而且清晰地出现在第Ⅳ时相卵母细胞的滤泡膜上。     

大银鱼卵细胞粘丝扫描电镜观察

用扫描电镜观察了大银鱼的第Ⅲ时相，第Ⅳ时相，第Ⅴ时相卵母细胞和受精卵的卵细胞粘丝的外部形态特征和它们的粘性，并讨论了卵细胞粘丝的功能。     

In Vitro and In Vivo Dendritic Cell Immune Stimulation Effect of Low Molecular Weight Fucoidan from New Zealand Undaria pinnatifida

Low molecular weight fucoidan (LMWF) has been reported to have immunomodulation effects through the increase of the activation and function of macrophages. In this study, the regulating effect of LMWF from Undaria pinnatifida grown in New Zealand on dendritic cells (DCs) was investigated. We discovered that LMWF could stimulate DCs’ maturation and migration, as well as CD4+ and CD8+ T cells’ proliferation in vitro. We proved that this immune promoting activity is activated through TLR4 and its downstream MAPK and NF–κB signaling pathways. Further in vivo (mouse model) investigation showed that LMWF has a strong immunological boosting effect, such as facilitating the proliferation of immune cells and increasing the index of immune organs. These findings suggest that LMWF has a positive immunomodulatory effect and is a promising candidate to supplement cancer immunotherapy.     

黄芪多糖在LPS诱导的DF-1细胞炎症反应中的抗炎作用及其调节机制

为探讨黄芪多糖(Astragalus polysaccharide,APS)在LPS(lipopolysaccharide,LPS)诱导的鸡胚成纤维细胞系DF-1(chicken embryonic fibroblast cell line,DF-1)炎症模型中对IL-1β和TNF-α表达的影响,以及细胞因子信号转导抑...     

利用单根肌纤维法分离和培养猪骨骼肌卫星细胞及其成肌诱导分化

建立单根肌纤维法体外培养猪骨骼肌卫星细胞的体系,了解其增殖和成肌特性。通过Ⅰ型胶原酶消化,从猪骨骼肌中分离完整的单根肌纤维并培养,用细胞免疫荧光鉴定肌纤维上的卫星细胞,随后对从单根肌纤维上游离出来的卫星细胞进行细胞免疫荧光染色,传代培养,成肌诱导分化和Western blot分析骨骼肌卫星细胞成肌特异性蛋白的表达。结果显示:分离并培养的单根肌纤维上附着有卵圆形的细胞,并随时间的推移,细胞缓慢向外迁移并增殖,卫星细胞特异性标志基因对盒转录因子(Paired protein box,Pax7)和成肌分化抗原(Myogenic Differentiation Antigen,MyoD)免疫荧光染色呈阳性,且阳性率达到90%以上。成肌诱导分化后,细胞开始汇合,并呈方向性生长,最终形成多核肌管,且成肌特异性标志基因Myogenin和myosin heavy chain(MyHC)表达呈阳性。MyoD蛋白高表达于增殖期,而Myogenin和MyHC在进入分化期才表达。该实验成功建立了猪骨骼肌单根肌纤维的体外培养方法并获得了高纯度的卫星细胞,为骨骼肌卫星细胞进行活体移植治疗相关疾病研究提供了实验材料。     

基于微生物燃料电池供能的无线温度传感系统设计

微生物燃料电池(microbial full cell,MFC)是利用微生物作为生物催化剂将碳水化合物转化为电能的装置。针对MFC输出电压低、功率小、内阻大的特点,该文研制了一种具有最大功率点跟踪(maximum power point tracking,MPPT)功能的能量收集电路和两级升压电路;基于MSP430和CC2500芯片设计了环境温度传感系统。测试结果表明,MFC的输出电压维持在316～390 mV范围内,实现了最大输出功率的跟踪,MPPT电路和升压电路分别输出1.1和3.5 V电压;无线温度传感器以每13ms的周期将环境温度无线传输到远程终端,验证了环境温度传感系统在最大功率点处对无线传感器网络节点供电工作的可行性,可为实现MFC主动式能量收集提供参考。