Pyroptosis mediates high glucose-induced inflammation and injury in MC3T3-E1 osteoblasts

AIM To investigate whether pyroptosis contributes to the inflammation and injury in mouse embryonic osteoblastic cell line MC3T3-E1 induced by high glucose (HG; 45 mmol/L glucose). METHODS The cell viability was measured by CCK-8 assay. The protein expression levels of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and caspase-1 (CASP1) were determined by Western blot. The secretion levels of interleukin-18 (IL-18) and IL-1β were measured by ELISA. The intracellular level of reactive oxygen species (ROS) was detected by 2',7'-dichlorodihydrofluorescein diacetate staining followed by photofluorography. Mitochondrial membrane potential (MMP) was examined by rhodamine 123 staining followed by photofluorography. The alkaline phosphatase (ALP) activity was determined using the ALP kit, and the number of mineralized nodules was detected by alizarin red S staining. RESULTS After the MC3T3-E1 osteoblasts were treated with HG for 24 h, the protein expression levels of NLRP3 and CASP1, and the secretion levels of IL-18 and IL-1β were significantly increased. The decrease in cell viability, and the increases in ROS generation and MMP loss were also observed. Moreover, the differentiation and mineralization of MC3T3-E1 osteoblasts were inhibited, evidenced by decreases in both ALP activity and mineralized nodule number. Knockdown of CASP1 by siRNA attenuated the HG-induced osteoblast inflammation and injury mentioned above. CONCLUSION Pyroptosis mediates HG-induced inflammation and injury in MC3T3-E1 osteoblasts.     

基于“流水线”的茄果类种苗半自动嫁接机研究

阐述了国内外茄果类种苗半自动嫁接机存在的作业生产率过低的问题,针对国内种苗嫁接环境,以茄果类种苗为作业对象,提出了基于"流水线"的半自动嫁接作业模式,选取适合机械化操作的贴接嫁接法,分析了生产节拍、作业工序与作业生产率的关系,最终将夹持、切削、拢苗、对接、上夹和下苗6个工序合理分配至4个工位。进行了整机嫁接作业试验,结果表明基于"流水线"的嫁接生产模式可实现1000株/h的嫁接生产率,有效提高了作业效率。     

湖南特有植物及园林应用和保护

通过对湖南137种特有植物研究表明:湖南特有植物主要从较进化的科和亲缘种较多的属中分化出来,为第四纪后期形成的新特有植物。地理分布广泛,从低海拔到高海拔,全省范围内都有分布。但以海拔500~1 200 m较集中,类型也多样。南岭山地、雪峰山和武陵山种类最多。这是水热条件的协调配合直接影响其分布格局。根据特有植物的特点,应加强针对性的保护和应用。     

濒危植物穗花杉生物学、生物普特性研究

穗花杉是第三纪残遗、濒危物种,曾广布于欧亚大陆,现仅间断分布于我国南方中山地带,地跨北热带、亚热带和温带.以湖南绥宁县神坡山和江华县大锡乡穗花杉林为重点,对国内主要分布区进行了调查,对穗花杉的分类,生物学与生态学特性,地理分布,群落特征与演替规律,繁殖与保护利用等进行了深入的研究,认为将其置于红豆杉科,并单独将穗花杉属成立一个族较为恰当.该树生长缓慢,结种量少,雌树少、雄树多,对生境要求严格,所以种群数量少,一般呈零星分布状态.采用在半自然生境育苗和种植的方式进行适地保护,简单、经济、效果好.     

石门国家森林公园风景资源质量等级评定

文章是在对广东省石门国家森林公园风景资源进行全面系统普查的基础上,依据《中国森林公园风景资源质量等级评定》（GB/T 18005-1999）标准,从风景资源质量评价,区域生态状况评价和旅游开发利用条件评价等三个方面对石门国家森林公园进行等级评定,结果表明石门国家森林公园风景质量达到一级,风景资源的资源价值和旅游价值高,评定结果可为公园的保护性开发提供科学依据和理论指导。     

岳阳市观赏植物造景应用评价

在对岳阳市城市观赏植物区系、植被与群落调查基础上,对观赏植物进行了园林应用分类,并对秋色叶植物和观果植物进行应用评价,提出了观赏植物造景应用方式.     

Effects of microglia-derived IL-1β on differentiation of OPCs in corpus callosum of septic neonatal rats

AIM: To explore whether IL-1β inhibits the oligodendrocyte precursor cell (OPCs) differentiation and affects axonal myelination. METHODS: One-day-old SD rats were randomly divided into control group and LPS group (48 rats in each group). The rats in LPS group were intraperitoneally injected with 1 mg/kg LPS. The rats in control group were injected with an equal volume of PBS. The rats in each group were further divided into 3 h, 24 h, 3 d, 7 d, 14 d and 28 d subgroups after injection. The expression of IL-1β and IL-1R₁ in the rat corpus callosum at 3 h, 24 h, 3 d, 7 d was determined by double immunofluorescence and Western blotting. The myelin basic protein(MBP) expression in the rat corpus callosum at 14 d, 28 d after injection was also measured. In vitro, primary OPCs culture was performed and divided into control group, 30 μg/L IL-1β group, 30 μg/L IL-1β+IL-1Ra group and 30 μg/L IL-1Ra group. The expression of MBP in the OPCs induced differentiation for 3 d was observed by double immunofluorescence and Western blotting. RESULTS: The expression of IL-1β and IL-1R₁ in the rat corpus callosum at 3 h, 24 h, 3 d, 7 d after LPS injection was obviously increased and the expression of MBP in the rat corpus callosum at 14 d, 28 d in LPS group was obviously decreased compared with control group in vivo. The level of MBP was significantly decreased after IL-1β treatment for 3 d in vitro. However, IL-1Ra (IL-1R inhibitor) reversed the down-regulation of MBP expression. IL-1β inhibited the expression of p-ERK, ERK over-expression reversed the down-regulation of MBP expression compared with IL-1β group. CONCLUSION: IL-1β inhibits the differentiation of OPCs, which may be involved in ERK pathways, thus leading to axonal hypomyelination in the corpus callosum of septic neonatal rats.     

Effects of myosin light chain kinase on regulation of endothelial barrier function

Myosin light chain kinase (MLCK) activates the regulatory light chain of myosin II, and the phosphorylated myosin light chain leads to actomyosin contractile activity, as well as the cell contraction and increasing intercellular gap, which finally results in endothelial barrier dysfunction. MLCK-dependent hyperpermeability occurs in response to multiple cell signaling molecules and signaling pathways, including Ca²⁺, Src, PKC, NO, cGMP and mitogen activated protein kinases (MAPK). In this review, different mechanisms of endothelial hyperpermeability mediated by MLCK are discussed.     

Mesenchymal stem cell-induced CD8α+ Jagged2high CD11bhigh regulatory dendritic cells prevent and treat mouse aGVHD

AIM: To investigate the role of mesenchymal stem cell-induced regulatory dendritic cells (MSC-DCregs) in mouse acute graft-versus-host disease(aGVHD) model. METHODS: Bone marrow cells from BALB/c (H-2^d) mice were isolated and were induced to differentiate into DCs. The DCs were selected by flow cytometry, and after 10 d co-culture with MSCs, they were induced to be MSC-DCregs. Male 8-week-old C57BL/6 (H-2^b) mice were used as donor mice. The female 8-week-old BALB/c (H-2^d) mice, who had received 100 cm source-skin distance, 30 cm×30 cm radiation field, 700 cGy total body irradiation (TBI) pretreatment were used as recipient mice. The recipients were divided into 5 groups: control group, TBI group (injected with medium only), bone marrow transplantation group (injected with 1×10⁷ bone marrow cells), aGVHD group (injected with 1×10⁷ bone marrow cells and 1×10⁷ spleen cells), and MSC-DCregs group (injected with 1×10⁷ bone marrow cells, 1×10⁷ spleen cells and 1×10⁶ MSC-DCregs). The white blood cell count, recipients' chimerism, clinical evaluation of aGVHD, survival analysis and pathological changes were determined. RESULTS: Hematopoieic recovery was seen at 10 d after transplantation. The recipients' chimerism was parallel to the donors' at 30 d. The median survival time of the mice in aGVHD group and MSC-DCregs group was 27 d and 33 d, and the survival rates at 30 d were 20% and 100% (P<0.01), respectively. The clinical scores of the mice in MSC-DCregs group were lower than those in aGVHD group (P<0.01). Moreover, the pathological changes in the skin and liver of the mice in MSC-DCregs group were less serious than those in aGVHD group. CONCLUSION: The MSC-DCregs induce an aGVHD tolerance in vivo, and further research of its mechanism is still in great necessary.