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91.
During craniofacial development, Meckel's cartilage and the mandible bone derive from the first branchial arch, and their development depends upon the contribution of cranial neural crest (CNC) cells. We previously demonstrated that conditional inactivation of Tgfbr2 in the neural crest of mice (Tgfbr2fl/fl;Wnt1-Cre) results in severe defects in mandibular development, although the specific cellular and molecular mechanisms by which TGF-β signaling regulates the fate of CNC cells during mandibular development remain unknown. We show here that loss of Tgfbr2 does not affect the migration of CNC cells during mandibular development. TGF-β signaling is specifically required for cell proliferation in Meckel's cartilage and the mandibular anlagen and for the formation of the coronoid, condyle and angular processes. TGF-β-mediated connective tissue growth factor (CTGF) signaling is critical for CNC cell proliferation. Exogenous CTGF rescues the cell proliferation defect in Meckel's cartilage of Tgfbr2fl/fl;Wnt1-Cre mutants, demonstrating the biological significance of this signaling cascade in chondrogenesis during mandibular development. Furthermore, TGF-β signaling controls Msx1 expression to regulate mandibular osteogenesis as Msx1 expression is significantly reduced in Tgfbr2fl/fl;Wnt1-Cre mutants. Collectively, our data suggest that there are differential signal cascades in response to TGF-β to control chondrogenesis and osteogenesis during mandibular development. 相似文献
92.
PCR-DGGE detection of the bacterial community structure in the Inner Mongolia steppe with two different DNA extraction methods 总被引:1,自引:0,他引:1
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Compared with conventional methods, molecular biological technique, such as PCR-DGGE (denaturing gradient gel electrophoresis), is informative in examining the structure of the soil bacterial community through the extraction of microbial DNA from soil and generation of bacterial community profiles by PCR amplification of 16S rRNA genes. Extraction efficiency of soil microbial DNA is the most important step in these methods. At present, the frozen-thawing method and bead-beating method are most widely used in genomic extraction. Nevertheless, comparison of these two methods has not been conducted in different soil types, especially in humus-rich soil. In this study, extraction efficiencies of the two methods were compared in humus-rich steppe soil in Inner Mongolia based on the PCR-DGGE analysis of bacterial community structure. The results indicated that the bead-beating method is better than the frozen-thawing method in genomic DNA extraction efficiency. In addition, 21 bands in the DGGE pattern with the bead-beating method were further selected, cloned and sequenced. Based on similarity matching, all the sequences formed five major clusters: Actinobacteria; α-, β-, γ-, Proteobacteria ; Bacteriodetes ; Gemmatimonadetes and Acidobacteria . Of the 21 clones obtained from DGGE patterns, YC4 showed 99.7% similarity to Pseudomonas sp. (DQ339153); YC5, YC18 and YC19 showed 99.9 % similarity to Gram-positive bacterium (AB008510), Virgisporangium ochraceum (AB006162) and Micromonospora chalcea (X92613), respectively. 相似文献
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Glioblastoma (GBM), a malignant and lethal tumor, remains a big threat to human health and life. Increasing explorations have confirmed that long noncoding RNAs are involved in the tumorigenesis and development of multiple cancers. Nevertheless, the regulatory mechanism of (long intergenic nonprotein coding RNA 1579 LINC01579) in GBM remains to be investigated. In this study, the expression of LINC01579 was upregulated in GBM cells and LINC01579 knockdown inhibited cell proliferation as well as promoted cell apoptosis. Additionally, LINC01579 acted as a sponge for miR-139-5p in GBM and eukaryotic translation initiation factor 4 gamma 2 (EIF4G2) was found to be a downstream target of miR-139-5p. Furthermore, the positive correlation of LINC01579 and EIF4G2 as well as the converse correlation between miR-139-5p and LINC01579 (or EIF4G2) were revealed by the experiments. Based on rescue assays, EIF4G2 overexpression or miR-139-5p inhibitor partially recovered the function of LINC01579 knockdown on cell proliferation and apoptosis. In summary, the results of this study verified that LINC01579 modulated cell proliferation and cell apoptosis in GBM by competitively binding with miR-139-5p to regulate EIF4G2, which provided a new clue to figure out potential therapy for patients suffered from GBM. 相似文献
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Han Feng Liu Liping Lu Jiaxi Chai Yingjuan Zhang Jie Wang Shijin Sun Licui Wang Qin Liu Yiqun He Mengjie Mu Weipeng Huang Zhenwu 《Biological trace element research》2019,188(2):363-372
Biological Trace Element Research - The required selenium intake for optimal health in Chinese residents was published in 2014. However, the adequate intake (AI) value for Chinese infants... 相似文献
98.
Pseudomonas amygdali pv. lachrymans is currently of important plant pathogenic bacteria that causes cucumber angular leaf spot worldwide. The pathogen has been studied for its roles in pathogenicity and plant inheritance resistance. To further delineate traits critical to virulence, invasion and survival in the phyllosphere, we reported the first complete genome of P. amygdali pv. lachrymans NM002. Analysis of the whole genome in comparison with three closely-related representative pathovars of P. syringae identified the conservation of virulence genes, including flagella and chemotaxis, quorum-sensing systems, two-component systems, and lipopolysaccharide and antiphagocytosis. It also revealed differences of invasion determinants, such as type III effectors, phytotoxin (coronatine, syringomycin and phaseolotoxin) and cell wall-degrading enzyme, which may contribute to infectivity. The aim of this study was to derive genomic information that would reveal the probable molecular mechanisms underlying the virulence, infectivity and provide a better understanding of the pathogenesis of the P. syringae pathovars. 相似文献
99.
Qingye Zeng Wancheng Lu Zhenhui Deng Bei Zhang Jiena Wu Jinwei Chai Xin Chen Xueqing Xu 《The Journal of biological chemistry》2022,298(1)
The Kv1.3 channel has been widely demonstrated to play crucial roles in the activation and proliferation of T cells, which suggests that selective blockers could serve as potential therapeutics for autoimmune diseases mediated by T cells. We previously described that the toxin mimic FS48 from salivary gland of Xenopsylla cheopis downregulates the secretion of proinflammatory factors by Raw 264.7 cells by blocking the Kv1.3 channel and the subsequent inactivation of the proinflammatory MAPK/NF-κB pathways. However, the effects of FS48 on human T cells and autoimmune diseases are unclear. Here, we described its immunomodulatory effects on human T cells derived from suppression of Kv1.3 channel. Kv1.3 currents in Jurkat T cells were recorded by whole-cell patch-clamp, and Ca2+ influx, cell proliferation, and TNF-α and IL-2 secretion were measured using Fluo-4, CCK-8, and ELISA assays, respectively. The in vivo immunosuppressive activity of FS48 was evaluated with a rat DTH model. We found that FS48 reduced Kv1.3 currents in Jurkat T cells in a concentration-dependent manner with an IC50 value of about 1.42 μM. FS48 also significantly suppressed Kv1.3 protein expression, Ca2+ influx, MAPK/NF-κB/NFATc1 pathway activation, and TNF-α and IL-2 production in activated Jurkat T cells. Finally, we show that FS48 relieved the DTH response in rats. We therefore conclude that FS48 can block the Kv1.3 channel and inhibit human T cell activation, which most likely contributes to its immunomodulatory actions and highlights the great potential of this evolutionary-guided peptide as a drug template in future studies. 相似文献