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101.
Adipocyte–Epithelial Interactions Regulate thein VitroDevelopment of Normal Mammary Epithelial Cells
Danilo Zangani Kathleen M. Darcy Suzanne Shoemaker Margot M. Ip 《Experimental cell research》1999,247(2):399
Mammary epithelial organoids (MEO), isolated from pubescent rats, were cultured within a reconstituted basement membrane in transwell inserts, in the presence or absence of mature mammary adipocytes in the lower well. This system allowed for free medium exchange between the two compartments, without direct cell-to-cell contact. When cultured in serum-free medium supplemented with insulin, prolactin, hydrocortisone, progesterone, and various epidermal growth factor (EGF) concentrations, mammary adipocytes did not affect epithelial cell growth, but enhanced epithelial differentiation. Casein and lipid accumulations were monitored as indicators of functional differentiation of MEO. Mammary adipocytes significantly enhanced casein and lipid accumulation within the MEO, independently of EGF concentration. Furthermore, adipocytes induced MEO to preferentially undergo alveolar morphogenesis, inhibited squamous outgrowth, and increased lumen size. These findings demonstrate that morphological and functional differentiation of mammary epithelial cells is profoundly enhanced by the adipose stroma and that these effects are mediated by diffusible paracrine factors. This new model can be exploited in future studies to define the mechanisms whereby hormones and growth factors regulate mammary gland development and carcinogenesis. Moreover, it could complementin vivoreconstitution/transplantation studies, which are currently employed to evaluate the role of specific gene deletions in the regulation of mammary development. 相似文献
102.
Several different in vivo and in vitro bioassays are used to evaluate melanosome transfer efficacy from melanocytes to keratinocytes. However, these methods are complicated and time consuming. Here, we report on a simple, rapid, direct, and reliable in vitro method for observing the process of melanosome transfer from melanocytes to keratinocytes. First, we selected and tested a melanoma cell line RPMI-7951 that can normally synthesize melanin and transfer from mature melanosomes to keratinocytes in vitro. We cocultured these cells with a human ovarian teratoma transformed epidermal carcinoma cell line, which is also capable of accepting melanosomes transferred from melanocytes, as in normal keratinocytes. The cells were cocultured for 24-72 h and double labeled with FITC-conjugated antibody against the melanosome-associated protein TRP-1, and with Cy5-conjugated antibody against the keratinocyte-specific marker keratin 14. The cells were examined by fluorescence microscope and flow cytometry. Melanosome transfer from melanocytes to keratinocytes increased in a time-dependent manner. To verify the accessibility of this method, the melanosome transfer inhibitor, a serine protease inhibitor, 4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride, and a melanosome transfer stimulator, alpha-melanocyte-stimulating hormone, were added. The serine protease inhibitor decreased melanosome transfer, and alpha-melanocyte-stimulating hormone increased melanosome transfer, in a dose-dependent manner. In conclusion, this is a simple, rapid, and effective model system to quantify the melanosome transfer efficacy from melanocytes to keratinocytes in vitro. 相似文献
103.
Hideo Satsu Tatsuya Yokoyama Nobumasa Ogawa Yoko Fujiwara-Hatano Makoto Shimizu 《Cytotechnology》2001,35(1):73-79
The interaction between intestinal epithelial cells andperipheral neuronal cells were examined using an invitro coculture system. Two cell lines, Caco-2 and PC12, were usedfor this experiment as an intestinal epithelial and entericneuronal cell model, respectively. By coculturing with fullydifferentiated Caco-2 cells, the neurite outgrowth was inducedin PC12 cells. This neurite outgrowth in PC12 was blocked byanti-nerve growth factor (NGF) polyclonal antibodies,suggesting that the neurite outgrowth in PC12 during thecoculture with Caco-2 cells was due to NGF secreted fromCaco-2 cells. On the other hand, coculturing with fullydifferentiated PC12 cells induced the decrease oftransepithelial electrical resistance in Caco-2 cellmonolayers. The permeability of lucifer yellow alsosignificantly increased, suggesting that the barrier functionand paracellular permeability of Caco-2 monolayers werealtered by coculturing with PC12 cells. The present studysuggests that this in vitro coculture system is a good modelfor the functional analysis of interaction among intestinalepithelial cells with different cell types. 相似文献
104.
互营氧化产甲烷微生物种间电子传递研究进展 总被引:4,自引:1,他引:3
甲烷是重要的温室气体,也是典型的可再生性生物质能源。目前约70%的大气甲烷排放来源于产甲烷微生物过程。在产甲烷环境中,产甲烷菌与互营细菌形成互营关系,从而克服有机质厌氧分解反应的热力学能垒,实现短链脂肪酸和醇类物质的互营氧化产甲烷过程。该过程中,种间电子传递是关键步骤。本文首先概述了甲烷的研究意义及微生物互营降解有机质产甲烷的过程,然后分别综述了种间H2转移、种间甲酸转移和种间直接电子传递这3种种间电子传递机制的起源、发展、研究现状和未来所需要解决的研究问题。 相似文献
105.
Hydrogen metabolism was studied in anoxic sediments of the stratified Lake Mendota; using a method which allowed the measurement of in situ H2 concentrations and the headspace-free analysis of turnover of dissolved H2. Addition of sulfate resulted in partial but immediate inhibition of H2-dependent methanogenesis. Sulfate addition did not result in an immediate decrease in the steady state concentration of dissolved H2, nor did it significantly stimulate the rate constant of H2 turnover. Sulfate-induced decrease in dissolved H2 was only observed after prolonged incubation or when endogenous H2 production was stimulated by added glucose. The turnover of the in situ H2 accounted for only 14% of the H2-dependent methanogenesis from bicarbonate. While rates of methanogenesis increased during the season, rates of H2 turnover decreased, accounting for only 2% of the H2-dependent methanogenesis at the end of summer stratification. These observations indicate that increasing proportions of CH4 were formed from H2 being directly transferred in syntrophic methanogenic associations. The rapid inhibition of H2-dependent methanogenesis by exogenous sulfate may be explained at least partially by assuming methanogenic associations in which syntrophic sulfate reducers change their metabolism from fermentative H2 production to sulfate reduction. 相似文献
106.
脑啡肽增强胶质细胞的神经营养作用与NO生成减少有关 总被引:2,自引:0,他引:2
本文在SD大鼠大脑皮层胶质细胞神经元共培养模式上,以神经元存活、突起生长、生长相关蛋白43(growthasociatedprotein43,GAP43)mRNA的表达为指标,观察了脑啡肽对胶质细胞神经营养作用的影响,并对其机理作了初步探讨。结果表明,经脑啡肽处理的胶质细胞能使神经元的存活计数增加28%(P<005),单个神经元突起总长度增加11%(P<005),最长突起长度增加16%(P<005),GAP43mRNA的表达增加26%(P<005)。然后又观察了脑啡肽(10-6~10-12mol/L)对培养胶质细胞生成一氧化氮(NO)的影响。结果表明,浓度为10-8,10-10mol/L的脑啡肽能明显抑制其生成(P<005)。结果提示,脑啡肽可能增强胶质细胞的神经营养作用,其机制之一可能是通过抑制胶质细胞NO的生成。 相似文献
107.
Ethanol, propanol, ethylene glycol, 1,2-propanediol, 1,2-butanediol, acetoin, diacetyl, and 2,3-pentanedione were used as substrates for enrichment and isolation of alcohol-oxidizing fermentative bacteria. Diacetyl and 2,3-pentanedione proved to be highly toxic. With the other substrates, various kinds of bacteria could be isolated which were assigned to three different metabolic groups: (i) homoacetogenic bacteria, and (ii) bacteria forming propionate as reduced end product were isolated from freshwater sources; (iii) bacteria disproportionating acetoin and 1,2-diols to acids and primary alcohols were isolated from marine sediments. The latter oxidized primary alcohols to fatty acids in the presence of hydrogen-oxidizing partners. Syntrophically ethanol-oxidizing cocultures enriched with primary alcohols could be separated with 1,2-diols as substrates into an alcohol-oxidizing organism and a hydrogen-oxidizing homoacetogen. The pathways of alcohol conversion in the disproportionating isolates were studied in detail. Growth experiments as well as enzymological studies demonstrated that acetoin and 1,2-diols were degraded via acetaldehyde which was also an intermediate in syntrophic oxidation of primary alcohols. The environmental importance of the various metabolic types isolated was assessed by most-probable-number enumerations. 相似文献
108.
109.
《Systematic and applied microbiology》2020,43(2):126057
We report on the characterization of a novel genomic assembly (ARYD3) recovered from formation water (17.6% salinity) and crude oil enrichment amended by isolated soy proteins (0.2%), and incubated for 100 days under anaerobic conditions at 50 °C. Phylogenetic and phylogenomic analysis demonstrated that the ARYD3 is unaffiliated with all currently described bacterial phyla and candidate phyla, as evident by the low AAI (34.7%), shared gene content (19.4%), and 78.9% 16S rRNA gene sequence similarity to Halothiobacillus neapolitanus, its closest cultured relative. Genomic characterization predicts a slow-growing, non-spore forming, and non-motile Gram-negative rod. Adaptation to high salinity is potentially mediated by the production of the compatible solutes cyclic 2,3-diphosphoglycerate (cDPG), α-glucosylglycerate, as well as the uptake of glycine betaine. Metabolically, the genome encodes primarily aminolytic capabilities for a wide range of amino acids and peptides. Interestingly, evidence of propionate degradation to succinate via methyl-malonyl CoA was identified, suggesting possible capability for syntrophic propionate degradation. Analysis of ARYD3 global distribution patterns identified its occurrence in a very small fraction of Earth Microbiome Project datasets examined (318/27,068), where it consistently represented an extremely rare fraction (maximum 0.28%, average 0.004%) of the overall community. We propose the Candidatus name Mcinerneyibacterium aminivorans gen. nov, sp. nov. for ARYD3T, with the genome serving as the type material for the novel family Mcinerneyibacteriaceae fam. nov., order Mcinerneyibacteriales ord. nov., class Mcinerneyibacteria class nov., and phylum Mcinerneyibacteriota phyl. nov. The type material genome assembly is deposited in GenBank under accession number VSIX00000000. 相似文献
110.