Strontium renelate promotes osteogenesis via regulation of Sonic hedgehog signaling molecules in rat bone marrow mesenchymal stem cells

AIM：To study the role of Sonic Hedgehog (Shh) in strontium ranelate (Sr)-induced osteogenic differentiation of rat bone marrow mesenchymal stem cells (BMSCs). METHODS：BMSCs was isolated from 4-week-old rats by adherent culture. The cells in the 3rd～5th generations were induced to differentiate into obteoblasts, and then were treated with different concentrations of Sr and cyclopamine (Cy). The activity of alkaline phosphatase (ALP) was mea-sured by colorimetry. Mineralized nodules were observed by alizarin red staining. The cellular Shh and Runx2 expression was detected by Western blotting. RESULTS：Sr at concentration of 3 mmol/L increased the activity of ALP and induced the formation of mineralized nodules. Sr at concentrations ranging from 0.1 to 5 mmol/L increased the expression of Shh and Runx2 in the BMSCs at 7 d. Furthermore, the peak expression of Shh occurred following the exposure of Sr (1 mmol/L) or Runx2 (3 mmol/L). On the other hand, Sr at concentration of 1 mmol/L showed a time-dependent increase in the expression of Shh and Runx2 from 1 d to 7 d. Cy at concentration of 10 μmmol/L not only obviously inhibited Sr-induced expression of Shh and Runx2, but also antagonized the increase in the ALP activity and mineralization induced by Sr in the BMSCs. CONCLUSION：Sr promotes osteogenic differentiation of BMSCs by increasing the expression of Shh and Runx2.     

Wnt signaling pathway is involved in catalpol-induced proliferation of rat bone marrow mesenchymal stem cells

AIM：To investigate the changes of Wnt signaling pathway in catalpol-induced proliferation of rat bone marrow mesenchymal stem cells (BMSCs). METHODS：The BMSCs were isolated from SD rats, purified by differential time adherent method and divided into control group and catalpol (1.0 mg/L) group. Flow cytometry was used to detect the proliferation index of BMSCs. The mRNA levels of Wnt3a, Wnt5a, Wnt11 and β-catenin was evaluated by real-time PCR. In addition, the protein expression level of β-catenin was determined by Western blotting. RESULTS：Prolife-ration index was increased from 8.90%±0.46% to 17.93%±1.68% after treatment with catalpol (P<0.01). Compared with control group, the mRNA expression of Wnt5a, Wnt11 and β-catenin was all increased with catalpol treatment. No difference of Wnt3a mRNA expression between control group and catalpol group was observed. Meanwhile, the protein expression of β-catenin was increased in catalpol group compared with control group. CONCLUSION：Catalpol promotes BMSCs going into the cell cycle. Classical and non-classical Wnt signaling pathways are activated in this process.     

Effect of hypoxia on generation of neurospheres from adipose tissue-derived canine mesenchymal stromal cells

Adipose tissue-derived mesenchymal stromal cells (AT-MSCs) are good candidates for cell therapy due to the accessibility of fat tissue and the abundance of AT-MSCs therein. Neurospheres are free-floating spherical condensations of cells with neural stem/progenitor cell (NSPC) characteristics that can be derived from AT-MSCs. The aims of this study were to examine the influence of oxygen (O₂) tension on generation of neurospheres from canine AT-MSCs (AT-cMSCs) and to develop a hypoxic cell culture system to enhance the survival and therapeutic benefit of generated neurospheres.AT-cMSCs were cultured under varying oxygen tensions (1%, 5% and 21%) in a neurosphere culture system. Neurosphere number and area were evaluated and NSPC markers were quantified using real-time quantitative PCR (qPCR). Effects of oxygen on neurosphere expression of hypoxia inducible factor 1, α subunit (HIF1A) and its target genes, erythropoietin receptor (EPOR), chemokine (C-X-C motif) receptor 4 (CXCR4) and vascular endothelial growth factor (VEGF), were quantified by qPCR. Neural differentiation potential was evaluated in 21% O₂ by cell morphology and qPCR.Neurospheres were successfully generated from AT-cMSCs at all O₂ tensions. Expression of nestin mRNA (NES) was significantly increased after neurosphere culture and was significantly higher in 1% O₂ compared to 5% and 21% O₂. Neurospheres cultured in 1% O₂ had significantly increased levels of VEGF and EPOR. There was a significant increase in CXCR4 expression in neurospheres generated at all O₂ tensions. Neurosphere culture under hypoxia had no negative effect on subsequent neural differentiation. This study suggests that generation of neurospheres under hypoxia could be beneficial when considering these cells for neurological cell therapies.     

In vitro neuronal and osteogenic differentiation of mesenchymal stem cells from human umbilical cord blood

Mesenchymal stem cells (MSCs) have the capabilities for self-renewal and differentiation into cells with the phenotypes of bone, cartilage, neurons and fat cells. These features of MSCs have attracted the attention of investigators for using MSCs for cell-based therapies to treat several human diseases. Because bone marrow-derived cells, which are a main source of MSCs, are not always acceptable due to a significant drop in their cell number and proliferative/differentiation capacity with age, human umbilical cord blood (UCB) cells are good substitutes for BMCs due to the immaturity of newborn cells. Although the isolation of hematopoietic stem cells from UCB has been well established, the isolation and characterization of MSCs from UCB still need to be established and evaluated. In this study, we isolated and characterized MSCs. UCB-derived mononuclear cells, which gave rise to adherent cells, exhibited either an osteoclast or a mesenchymal-like phenotype. The attached cells with mesenchymal phenotypes displayed fibroblast-like morphologies, and they expressed mesenchym-related antigens (SH2 and vimentin) and periodic acid Schiff activity. Also, UCB-derived MSCs were able to transdifferentiate into bone and 2 types of neuronal cells, in vitro. Therefore, it is suggested that the MSCs from UCB might be a good alternative to bone marrow cells for transplantation or cell therapy.     

Analysis of the natural infection of European horse chestnut (Aesculus hippocastanum) by Pseudomonas syringae pv. aesculi

Pseudomonas syringae pv. aesculi (Psa) is an emerging bacterial pathogen responsible for a recent epidemic of bleeding canker of European horse chestnut (Aesculus hippocastanum) in northwest Europe. Very little is known about the infection biology of this pathogen, which can cause lethal cankers in the branches and stem of its host. In this study, branches and whole trees of European horse chestnut naturally infected with Psa were subjected to detailed morphological and histological examination to identify the primary infection sites, the time of infection, and the patterns of subsequent lesion expansion within the host. Lesions developed during the host dormant season on the 2003–2009 extension growth increments and were centred mainly on lenticels, leaf scars and nodes. The oldest lesion developed in the 2004/2005 dormant season and the number of new lesions increased in each subsequent year. The lesions developed in the cortex and phloem and extended into the cambium to cause cankers, but there was no evidence of necrosis in the xylem. All lesions on the branches were discrete and apparently contained by a necrophylactic periderm, although there was evidence that Psa could survive within such periderms and subsequently breach them. Examination of two whole 30‐year‐old trees revealed extensive, continuous cankers in the phloem and cambium which had formed within a single growing season. Thus, the success of Psa as a tree pathogen and the causal agent of a large‐scale epidemic may in part reflect an ability to infect the aerial woody parts of its host directly.     

Rat mesenchymal stem cells differentiate into neuron-like cells induced by berberine in vitro

AIM: To investigate whether berberine can induce rat mesenchymal stem cells (MSCs) to differentiate into neuron -like cells in vitro. METHODS: MSCs were separated from young rat femurs marrow and expanded in culture medium. MSCs were induced to differentiate by berberine. The morphological changes of MSCs were evaluated by light microscope.Neuron-spcific enolase (NSE), neurofilament (NF), glial fibrillary acidic protein (GFAP) were detected by immunohistochemistry. RESULTS: Induced by berberine for 8 hours,MSCs exhibited neurotype . The expression of NSE and NF in the neuron-like cells was positive, but the glial astrocyte marker GFAP didn't express. CONCLUSION: Berberine may induce adult rat MSCs to differentiate into neuron-like cells in vitro.     

兔胚胎的一些与分离胚胎干细胞有关的生物学特征

为获得具有发育全能性的胚胎干细胞（ＥＳ细胞）,对３日龄、３．５日龄和４日龄家兔胚胎的形态结构和免疫组化特征进行了观察。家兔胚胎的外围,不仅有透明带,还包有一层很厚的胶膜。３日龄兔胚为桑椹胚;３．５日龄胚胎已出现囊胚腔,囊胚腔较小,扩增内细胞团（ＩＣＭ）占据囊腔的１／２～２／３;４日龄为囊胚,囊腔扩大,ＩＣＭ与囊胚腔的体积比值缩小。桑椹胚的卵裂球和３．５日龄、４日龄胚胎的ＩＣＭ,以碱性磷酸酶染色和胚胎阶段特异性细胞表面抗原－１（ＳＳＥＡ－１）免疫荧光标记均呈强阳性,说明它们是由未分化的细胞构成。因此,从保证全能性的角度考虑,３日龄、３．５日龄和４日龄的家兔胚胎,均可用于ＥＳ细胞的分离。     

遮穗和去颖下燕麦穗部特征变化和穗部光合贡献率估算

随着探索提高植物整体光合能力相关研究的不断开展,麦类作物穗部器官等植物非叶绿色器官光合潜力挖掘逐渐得到关注。本研究在成都平原秋播美达、贝勒、莫尼卡、摄政王、泰克和甜燕60等6个品种燕麦,设置遮穗、去颖2个试验处理,比较分析了各品种间穗部特征、穗部光合贡献率、颖片光合贡献率和茎光合物质转移率等差异。结果表明,燕麦穗部器官光合贡献率为28.56%～49.05%,其中甜燕60最高;6个品种燕麦的颖片光合贡献率为11.03%～36.88%,茎光合物质转移率为6.65%～35.81%。燕麦穗部器官对籽实增重表现了较高的光合贡献,当燕麦穗部器官光合受到限制时,燕麦单粒种子重和单穗种子数显著降低,尤其是影响双粒小穗数。     

日粮中添加不同比例木薯茎叶对海南黑山羊生长性能、血清生化指标和养分表观消化率的影响

试验旨在研究将晒干的木薯茎叶以不同比例与精料混合制成的全混合日粮对海南黑山羊生长性能、血清生化指标和养分表观消化率的影响。选择20只海南黑山羊,分成4组（Ⅰ、Ⅱ、Ⅲ、Ⅳ组）,每组5只羊（3公2母）,Ⅰ、Ⅱ、Ⅲ、Ⅳ组的精料与木薯茎叶比例分别为3：7、4：6、5：5、6：4,试验期60 d。结果显示,Ⅲ组海南黑山羊的平均日增重（ADG）、平均日采食量（ADFI）均高于其他3组,且Ⅲ组ADG显著高于Ⅰ组（P<0.05）;除了Ⅰ组谷丙转氨酶（ALT）显著高于Ⅳ组（P<0.05）外,其他血清生化指标在各组间差异均不显著（P>0.05）;Ⅲ组的饲料养分表观消化率均最高,且均呈Ⅰ组到Ⅲ组逐渐升高,Ⅳ组降低的趋势。综合以上结果,海南黑山羊育肥羊日粮中木薯茎叶与精料的适宜比例为5：5,在此基础上,也可适当降低精料含量,增加木薯茎叶含量,以达到降低饲养成本的目的,但建议木薯茎叶添加比例不宜超过60%。     

Effect of dietary Moringa stem meal level on growth performance,slaughter performance and serum biochemical parameters in geese

Moringa stem meal (MSM) with a high level of crude fibre (CF) might be developed and utilized in herbivorous geese as an unconventional feedstuff. The aim of this study was to investigate the effect of the MSM level in the diet on the growth performance, slaughter performance, breast meat quality and serum biochemical parameters in geese from 22 to 70 days of age. A one-factor completely randomized design was adopted in our study. A total of one thousand eight 21-day-old geese were randomly divided into six groups, with six replicates per group and 28 birds per replicate. The geese were fed diets containing MSM levels of 0, 20, 40, 60, 80 or 100 g/kg during day 22–70. The dietary MSM level had no effect (p > .05) on the final body weight (BW), average daily gain (ADG) or average daily feed intake (ADFI). The feed/gain ratio (F/G) increased linearly (p < .001) as the dietary MSM level increased. No differences (p > .05) were observed in the slaughter performance, meat quality and the relative organ weight (except for thymus) of the geese (p > .05). The relative weight of the thymus in the geese fed diets with supplementation of MSM was higher than that in the non-supplemented MSM control group (p < .05). In addition, 100 g MSM/kg of diet decreased the serum glucose (GLU) level (p < .05) and increased the alanine transaminase (ALT) enzyme activity (p = .03). Dietary MSM levels of no more than 60 g/kg had no effects on the growth performance and slaughter performance, whereas diets with 100 g MSM/kg increased the F/G and serum ALT enzyme activity, as well as decreasing the serum GLU level. Therefore, MSM provided at a reasonable level could be developed as an unconventional feedstuff for geese at the finisher period.