共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
Shen Z Crotti TN Flannery MR Matsuzaki K Goldring SR McHugh KP 《Biochimica et biophysica acta》2007,1769(11-12):659-667
3.
Brewer JA Sleckman BP Swat W Muglia LJ 《Journal of immunology (Baltimore, Md. : 1950)》2002,169(3):1309-1318
To delineate the cellular targets and mechanisms by which glucocorticoids (GCs) exert their actions, we generated mice in which a green fluorescent protein (GFP)-GC receptor (GR) fusion gene is knocked into the GR locus. In these mice, the GFP-GR protein, which is functionally indistinguishable from endogenous GR, allows the tracking and quantitation of GR expression in single living cells. In GFP-GR thymus, GR expression is uniform among embryonic thymocyte subpopulations but gradually matures over a 3-wk period after birth. In the adult, GR is specifically induced to high levels in CD25(+)CD4(-)CD8(-) thymocytes and returns to basal levels in CD4(+)CD8(+) thymocytes of wild-type and positively selecting female HY TCR-transgenic mice, but not negatively selecting male HY TCR-transgenic mice. In GFP-GR/recombinase-activating gene 2(-/-) thymocytes, GR expression is down-regulated by pre-TCR complex stimulation. Additionally, relative GR expression is dissociated from GC-induced apoptosis in vivo. Results from these studies define differential GR expression throughout ontogeny, suggest pre-TCR activation as a specific mechanism of GR down-regulation, define immature CD8(+) thymocytes as novel apoptosis-sensitive GC targets, and separate receptor abundance from susceptibility to apoptosis across thymocyte populations. 相似文献
4.
5.
6.
7.
8.
9.
10.
Transgenic mice have been obtained with genes coding for an alpha beta T-cell receptor that recognizes the male-specific antigen H-Y in association with the Db class I major histocompatibility complex molecule. Most if not all of the T-cells express the beta chain encoded by the transgene and show allelic exclusion of endogenous beta genes. In contrast, the expression of the alpha transgene does not completely block rearrangement and formation of functional endogenous alpha genes. In H-2b transgenic female mice the transgenic T-cell receptor is functionally expressed on at least 30% of CD8+ peripheral T-lymphocytes as indicated by their ability to lyse male target cells. Also in transgenic H-2b male mice a large proportion of peripheral T-cells appear to express the transgenic receptor. However, these cells do not react with male target cells because they show only low level or no expression of CD8 cell interaction molecules. Tolerance is established in the male transgenic thymus through deletion of CD4+CD8+ immature thymocytes. 相似文献
11.
12.
13.
Transgenic mice reveal novel activities of growth hormone in wound repair, angiogenesis, and myofibroblast differentiation 总被引:4,自引:0,他引:4
Thorey IS Hinz B Hoeflich A Kaesler S Bugnon P Elmlinger M Wanke R Wolf E Werner S 《The Journal of biological chemistry》2004,279(25):26674-26684
An increasing number of patients are being treated with growth hormone (GH) for the enhancement of body growth but also as an anti-aging strategy. However, the side effects of GH have been poorly defined. In this study we determined the effect of GH on wound repair and its mechanisms of action at the wound site. For this purpose, we performed wound healing studies in transgenic mice overexpressing GH. Full thickness incisional and excisional wounds of transgenic animals developed extensive, highly vascularized granulation tissue. However, wound bursting strength was not increased. Wound closure was strongly delayed as a result of enhanced granulation tissue formation and impaired wound contraction. The latter effect is most likely due to a significantly reduced number of myofibroblasts at the wound site. By using in vitro studies with stressed collagen lattices, we identified GH as an inhibitor of transforming growth factor beta-induced myofibroblast differentiation, resulting in a reduction in fibroblast contractile activity. These results revealed novel roles of GH in angiogenesis and myofibroblast differentiation, which are most likely not mediated via insulin-like growth factors at the wound site. Furthermore, our data suggested that systemic GH treatment is detrimental for wound healing in healthy individuals. 相似文献
14.
Regulation of nerve growth factor receptor gene expression in sympathetic neurons during development 总被引:4,自引:2,他引:4
下载免费PDF全文

《The Journal of cell biology》1995,130(6):1435-1446
15.
16.
17.
Inukai K Nakashima Y Watanabe M Takata N Sawa T Kurihara S Awata T Katayama S 《American journal of physiology. Endocrinology and metabolism》2005,288(5):E876-E882
Adiponectin is an adipocyte-derived factor that plays pivotal roles in lipid and glucose metabolism in muscle and liver. The following two adiponectin receptor types were recently identified: AdipoR1 is abundantly expressed in muscle, whereas AdipoR2 is predominantly expressed in the liver. To clarify the regulation of adiponectin receptor gene expression in diabetic states, we examined mRNA levels of AdipoR1 in the muscles of diabetic animals by Northern blotting. The level of AdipoR1 mRNA was increased approximately 2.5-fold in muscle of streptozotocin (STZ) diabetic mice, but the normal level was restored by insulin administration, indicating that insulin has an inhibitory effect on AdipoR1 expression. To confirm this inhibitory effect of insulin, we performed in vitro experiments using C2C12 skeletal muscle cells. Insulin treatment for 24 h decreased AdipoR1 expression by approximately 60% in C2C12 cells. In addition, this effect was mediated by the phosphatidylinositol 3-kinase-dependent pathway rather than the mitogen-activated protein kinase pathway. AdipoR1 expression in insulin-resistant diabetic mice was also investigated. AdipoR1 expression was decreased by 36% in type 2 diabetic obese db/db mice compared with lean mice. In contrast, hepatic AdipoR2 expression was not significantly changed in either STZ mice or genetically obese mice. Our results indicate that regulation of AdipoR1, but not that of AdipoR2, may be involved in glucose and lipid metabolism in diabetic states. 相似文献
18.
19.
《The Journal of cell biology》1984,98(2):558-564
We have established schedules of expression during maize leaf development in light and darkness for the messenger RNAs (mRNAs) and polypeptides for ribulose 1,5-bisphosphate carboxylase (RuBPCase) subunits, phosphoenolpyruvate carboxylase (PEPCase), and the light- harvesting chlorophyll a/b-binding protein (LHCP). Levels of mRNAs were measured by hybridization with cloned probes, and proteins were measured by immunodetection on protein gel blots. The initial synthesis in leaves of all four mRNAs follows a light-independent schedule; illumination influences only the level to which each mRNA accumulates. The synthesis of RuBPCase small and large subunits and of PEPCase polypeptides also follows a light-independent schedule which is modified quantitatively by light. However, the accumulation of LHCP polypeptides absolutely requires illumination. The accumulation of each protein closely follows the accumulation of its mRNA during growth in light. Higher ratios of PEPCase and RuBPCase protein to mRNA occur during dark growth. 相似文献
20.
Crystallin gene expression during rat lens development 总被引:6,自引:0,他引:6