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31.
Wolfgang Ludwig Christiane Krönke 《Der Zoologische Garten (in deutscher Sprache / in German)》2012,81(2-3):96-112
When establishing a new breeding group of Naked mole-rats three significant hurdles are to overcome: 1. Determination of sex. 2. Get over the group specific smell (between individuals of different groups). 3. Get over the reproductive blockade. This report describes experiences achieving these goals as well as establishes requirements for a successful breeding. The sex determination of nonreproductive Naked mole rats is tainted with great uncertainty, because the anogenital region of both sexes appears quite similar. For a lack of births and a failure of rearing offspring the following reasons seem to be responsible: 1. Incorrect sex determination at the time of group founding. 2. The reproductive blockade could not be overcome because of disadvantageous hierarchical relations within the group. 3. Pregnancy is interrupted due to disturbances from outside the enclosure or social stress within the group. 4. Due to these disturbances the alpha-female is not often enough willing to suckle her youngsters. 相似文献
32.
Christiane Högermann 《当今生物学》2012,42(4):214-214
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We have previously shown that regulatory CD25(+)CD4(+) T cells are resistant to clonal deletion induced by viral superantigen in vivo. In this work we report that isolated CD25(+)CD4(+) T cells activated in vitro by anti-CD3 Ab are resistant to Fas-induced apoptosis, in contrast to their CD25(-)CD4(+) counterparts. Resistance of CD25(+)CD4(+) T cells to Fas-dependent activation-induced cell death is not linked to their inability to produce IL-2 or to their ability to produce IL-10. The sensitivity of both populations to Fas-induced apoptosis can be modulated in vitro by changing the CD25(+)CD4(+):CD25(-)CD4(+) T cell ratio. The sensitivity of CD25(-)CD4(+) T cells to apoptosis can be reduced, while the sensitivity of CD25(+)CD4(+) T cells can be enhanced. Modulation of Fas-dependent apoptosis is associated with changes in cytokine production. However, while CD25(-)CD4(+) T cell apoptosis is highly dependent on IL-2 (production of which is inhibited by CD25(+)CD4(+) T cells in coculture), modulation of CD25(+)CD4(+) T cell apoptosis is IL-2 independent. Taken together, these results suggest that CD25(+)CD4(+) and CD25(-)CD4(+) T cell sensitivity to Fas-dependent apoptosis is dynamically modulated during immune responses; this modulation appears to help maintain a permanent population of regulatory T cells required to control effector T cells. 相似文献
35.
Fournier HN Dupé-Manet S Bouvard D Lacombe ML Marie C Block MR Albiges-Rizo C 《The Journal of biological chemistry》2002,277(23):20895-20902
Cell adhesion-dependent signaling implicates cytoplasmic proteins interacting with the intracellular tails of integrins. Among those, the integrin cytoplasmic domain-associated protein 1alpha (ICAP-1alpha) has been shown to interact specifically with the beta(1) integrin cytoplasmic domain. Although it is likely that this protein plays an important role in controlling cell adhesion and migration, little is known about its actual function. To search for potential ICAP-1alpha-binding proteins, we used a yeast two-hybrid screen and identified the human metastatic suppressor protein nm23-H2 as a new partner of ICAP-1alpha. This direct interaction was confirmed in vitro, using purified recombinant ICAP-1alpha and nm23-H2, and by co-immunoprecipitation from CHO cell lysates over-expressing ICAP-1alpha. The physiological relevance of this interaction is provided by confocal fluorescence microscopy, which shows that ICAP-1alpha and nm23-H2 are co-localized in lamellipodia during the early stages of cell spreading. These adhesion sites are enriched in occupied beta(1) integrins and precede the formation of focal adhesions devoid of ICAP-1alpha and nm23-H2, indicating the dynamic segregation of components of matrix adhesions. This peripheral staining of ICAP-1alpha and nm23-H2 is only observed in cells spreading on fibronectin and collagen and is absent in cells spreading on poly-l-lysine, vitronectin, or laminin. This is consistent with the fact that targeting of both ICAP-1alpha and nm23-H2 to the cell periphery is dependent on beta(1) integrin engagement rather than being a consequence of cell adhesion. This finding represents the first evidence that the tumor suppressor nm23-H2 could act on beta(1) integrin-mediated cell adhesion by interacting with one of the integrin partners, ICAP-1alpha. 相似文献
36.
Approximately 20% of the healthy human population is persistently colonized in the nasal cavity with Staphylococcus aureus, which constitutes a major risk for infection. S. aureus seems to predominantly colonize the anterior part of the nasal cavity by adhering to nasal surface structures and escaping the host innate and adaptive immune responses. Several bacterial and host factors that play a role in these processes have been identified in the past few years and were in part functionally evaluated in appropriate colonization models. However, the dynamics of host-pathogen crosstalk is only partially understood. 相似文献
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38.
Christiane Elisabeth S?rensen Katerina Tritsaris Jesper Reibel Martin Lauritzen Erik Lykke Mortensen Merete Osler Anne Marie Lynge Pedersen 《PloS one》2016,11(3)
Background
The cell-cycle inhibitor and tumor suppressor cyclin dependent kinase inhibitor, p16ink4a, is one of the two gene products of the ink4a/ARF (cdkn2a) locus on chromosome 9q21. Up-regulation of p16ink4a has been linked to cellular senescence, and findings from studies on different mammalian tissues suggest that p16ink4a may be a biomarker of organismal versus chronological age.Objective
The aim of this study was to examine the immunolocalization pattern of p16ink4a in human labial salivary gland (LSG) tissue, and to analyze whether its expression level in LSGs is a peripheral correlate of cognitive decline in late midlife.Methods
The present study was a part of a study of causes and predictors of cognitive decline in middle-aged men in a Danish birth cohort. It is based on data from 181 male participants from the Danish Metropolit birth cohort, born in 1953, who were examined for age-associated alterations in cognition, dental health, and morphological and autonomic innervation characteristics of the LSGs. The participants were allocated to two groups based on the relative change in cognitive performance from young adulthood to late midlife. LSG biopsies were analyzed by qRT-PCR for the expression level of p16ink4a. Immunohistochemistry was performed on formalin-fixed, paraffin-embedded sections of LSGs.Results
p16ink4a immunoreactivity was observed in LSG ductal, myoepithelial, and stromal cells, but not in acinar cells. The mean relative expression of p16ink4a in LSGs was higher in the group of participants with decline in cognitive performance. A logistic regression analysis revealed that the relative p16 expression was predictive of the participant’s group assignment. A negative correlation was found between relative p16ink4a expression and the participant’s standardized regression residuals from early adulthood to late midlife cognitive performance scores.Conclusions
p16ink4a expression in human LSGs may constitute a potential peripheral correlate of cognitive decline. Human labial salivary glands seem suitable for studies on organismal as opposed to chronological age. 相似文献39.
Glycodelin protein and mRNA is downregulated in human first trimester abortion and partially upregulated in mole pregnancy. 总被引:1,自引:0,他引:1
Bettina Toth Karin Roth Christiane Kunert-Keil Christoph Scholz Sandra Schulze Ioannis Mylonas Klaus Friese Udo Jeschke 《The journal of histochemistry and cytochemistry》2008,56(5):477-485
Glycodelin (Gd) is a major reproductive glycoprotein and a mediator for immunomodulatory effects directed to cellular, humoral, and innate immunity. Human pregnancy depends on a diversity of physiological processes including modulation of the maternal immunosystem. We evaluated the expression of Gd protein and mRNA in first trimester decidual tissue of normal pregnancies and spontaneous abortion and hydatidiform moles. Furthermore, in vitro experiments on endometrial cancer cells to analyze the effect of human chorionic gonadotropin (hCG) on Gd regulation were performed. In decidual tissue of abortion patients, Gd expression was significantly decreased compared with normal gestation, which was confirmed by in situ hybridization. In mole pregnancy, an upregulation of Gd in the first 8 weeks of pregnancy was present. Gd is a main product of decidual tissue in the first trimester of human pregnancy. Reduced Gd expression in abortive pregnancy could lead to an increased activation of the maternal immunosystem, thus causing rejection of the developing fetus. Moreover, Gd expression in endometrial cancer cells in vitro could be stimulated by addition of hCG. Therefore, we speculate that hCG could be one of the factors regulating Gd expression because hCG is downregulated in women with abortion and upregulated in mole pregnancy. In addition, we found a positive feedback loop in Gd and hCG expression in human pregnancy. 相似文献
40.
Carolina Elejalde-Palmett Ignacio Martinez San Segundo Imène Garroum Laurence Charrier Damien De Bellis Antonio Mucciolo Aurore Guerault Jie Liu Viktoria Zeisler-Diehl Asaph Aharoni Lukas Schreiber Bénédicte Bakan Mads H. Clausen Markus Geisler Christiane Nawrath 《Current biology : CB》2021,31(10):2111-2123.e9