<thead id="wtvt8"></thead>

      <label id="wtvt8"></label>
        1. <li id="wtvt8"><big id="wtvt8"></big></li><span id="wtvt8"><optgroup id="wtvt8"></optgroup></span>
            国产黑色丝袜在线播放,97视频精品全国免费观看,日韩精品中文字幕有码,在线播放深夜精品三级,免费AV片在线观看网址,福利一区二区在线观看,亚洲深夜精品在线观看,2019亚洲午夜无码天堂

            武漢原生原代生物醫藥科技有限公司

            PriCells: Introduction of Isolation and Culture of Human Alveolar Epithelial Cells

            時間:2021-10-20 閱讀:268
            分享:

            PriCells: Introduction of Isolation and Culture of Human Alveolar Epithelial Cells


            1.1. Background
            The human lung consists of more than 40 different cell types. The morphology and function of constituent cells of the proximal, conducting airway epithelium differ drastically from those of the more distal, alveolar epithelium.

            No cell lines that possess significant functional properties of alveolar epithelial cells (AEC) are reported to date. Primary culture of AEC is, therefore, used for most in vitro studies of alveolar epithelial function (e.g., transport and various metabolic pathways). The primary culture of human alveolar epithelial cells involves isolation, purification, and culture of alveolar epithelial type II (ATII) cells from human tissue obtained after lung resections. These ATII cells, when plated on permeable supports or plasticware, acquire the type 1 cell-like phenotype and morphology under appropriate culture conditions. Owing to the lack of availability of human tissue and some ethical issues pertaining to use of human tissues in certain countries, most studies were based on isolation and culture of cells from the lungs of small laboratory animals including mouse, rat, and rabbit. However, not much information on species differences in this specific area of cellular research has been systematically studied yet.

            1.2. AECs
            ATII cells constitute about 60% of AECs and about 15% of all lung parenchymal cells, although they cover less than 5% of the alveolar air spaces of adult human lungs. It is well known that ATII cells synthesize, secrete, and recycle some components of the surfactant that regulates alveolar surface tension in the distal airspaces of mammalian lungs. ATII cells govern extracellular surfactant transformation by regulating, for example, pH and Ca2+ of the hypophase, and play various roles in alveolar fluid balance, coagulation/fibrinolysis, and contribute to host defense. ATII cells proliferate, differentiate into type I (ATI) cells, and remove apoptotic ATII cells by phagocytosis. thus, contributing to epithelial repair following lung injury. ATII cells are thought to be progenitor cells for type I cells, especially in injury/repair of epithelial tract lining the distal airspaces of the lung. For a summary of the latest state in type II cell research, the reader is encouraged to read Fehrenbach’s excellent review that appeared recently.

            Compared with its neighbor, the ATII cell, the ATI cell has received little attention. The general functions of ATI cells are relatively unexplored, because specific marker molecules that could be used for definitive identification of ATI cells were identified only very recently. Several ATI cell-specific gene products described below were used to address many problems in alveolar cell biology/molecular biology. Nonetheless, the identification of several proteins expressed by this cell and their presumed activities suggest more-sophisticated cell functions than mere gas exchange. The putative functions of type I cells include control of proliferation of peripheral lung cells, metabolism and/or degradation of peptides and peptide growth factors, generation of cyto/chemokines, regulation of alveolar fluid balance, and transcellular ion and water transport.

            1.3. Differentiation Markers for AECs
            The study of differentiation of type II cells into type I cells crucially depends on the possibility to distinguish both cell types. Beside the pure morphological characterization (e.g., presence of lamellar bodies, cuboidal shape), a number of alternative approaches to distinguish ATII from other cell types have been developed, such as modified Papanicolaou staining, cell-type-specific lectins, and immunohistochemical and immunocytochemical markers. The expression of markers, however, may be altered because of the specific culture conditions and the situation is further complicated by the transient appearance of an inter- mediate phenotype during differentiation, in that both ATI and ATII cell-like features may coexist in such cells. It has to be taken into account that so far there is no clear evidence showing that the differentiation of ATII cells definitively yield terminally differentiated ATI cells, necessitating the use of a term, “type I cell-like phenotype" to reflect this fact in the literature.

            It has been reported that specific lectins label apical membranes of either type I or type II cells. The lectins Ricinus communis 1, Bauhinia purpurea, and Lycopersicon esculentum bind to ATI cells, but not ATII cells, while Maclura pomifera binds to ATII, but not ATI cells. These findings strongly suggested that ATI cells express membrane glycoproteins (and/or glycolipids) that are distinctly different from those expressed on the apical cell membranes of ATII cells.

            A number of molecular markers, specific for type I cells, have been described in the recent past. The first one was T1α, a 36-kDa glycoprotein found in rodent lungs. Antibodies have been developed against lung proteins that specifically label type I cells in human lung with patterns that match those of rodent T1α. However, the human data are unclear, because antibodies to rodent T1α do not recognize ATI cell antigens in normal adult human lung. This likely indicates that O-glycosylation of the human protein(s), differs significantly from that of the rodent proteins.

            Aquaporin-5 (AQP-5), a second ATI cell marker, is a member of the large family of aquaporin proteins, most of which are water channels. AQP-5 is a transmembrane protein of approx 27–34-kDa that resides in the ATI cell apical plasma membrane. Immunohistochemical and immunocytochemical studies by several investigators with various antibodies, as well as Northern and Western analyses of isolated cells, have shown that AQP-5 is uniquely expressed by ATI cells in the peripheral regions of the lung.

            It was shown many years ago that ATI cells contain numerous, small, flask-shaped membrane invaginations, or caveolae, that open to the alveolar lumen or interstitial space. The presence of such caveolar structure in ATII cells is not clear yet. In addition to these caveolae at the cell membranes, numerous small vesicles are also noted in both ATI (but not ATII) cells and pulmonary vascular endothelial cells. Caveolin-1, a 21–24 kDa protein, is the major scaffolding protein that forms the vesicular skeleton of the caveolae. In the alveolar epithelium, caveolin-1 expression appears limited to ATI cells, as ATII cells normally express none or very little. Thus for many in vitro studies, caveolin-1 expression was used to discriminate between ATI and ATII cell phenotypes.

            Several monoclonal antibodies, that discriminate between unidentified ATI and ATII cell surface epitopes, have been produced. Some of these antibodies may recognize the markers described above. The epitope of some antibodies is not yet identified, an example being the rat type I cell-specific antibody, VIIIB2.

            Type I cells are also reported to express carbopeptidase membrane-bound enzyme (CP-M), intercellular adhesion molecule-1 (ICAM-1), β2-adrenergic receptor, insulin-like growth factor receptor-2 (IGFR-2), γ-glutamyl transferase (γ-GT), AQP-4, and VAMP-2, a membrane protein associated with caveolae. Whether or not these molecules are expressed in ATI cells exclusively or may also be present in other cell types needs still to be elucidated.


            會員登錄

            ×

            請輸入賬號

            請輸入密碼

            =

            請輸驗證碼

            收藏該商鋪

            X
            該信息已收藏!
            標簽:
            保存成功

            (空格分隔,最多3個,單個標簽最多10個字符)

            常用:

            提示

            X
            您的留言已提交成功!我們將在第一時間回復您~
            撥打電話 產品分類
            在線留言
            主站蜘蛛池模板: 国产一区二区一卡二卡| 国产精品中文字幕久久| 无码人妻丝袜在线视频| 国产精品多p对白交换绿帽| 亚洲av日韩在线资源| 性欧美VIDEOFREE高清大喷水| 国产精品无码av不卡| 中文字幕亚洲国产精品| 熟女系列丰满熟妇AV| 成人av午夜在线观看| 国产99视频精品免费专区| 久热综合在线亚洲精品| jizz视频在线观看| 日韩有码精品中文字幕| 国产av午夜精品福利| 欧美白妞大战非洲大炮| 亚洲欧美日韩成人综合一区 | 深田えいみ禁欲后被隔壁人妻 | 日韩中文字幕有码av| 国产av午夜精品福利| 国产高清在线男人的天堂| 亚洲 制服 丝袜 无码| 亚洲人成电影网站 久久影视| 亚洲尤码不卡av麻豆| 欧美白妞大战非洲大炮| 中文字幕国产精品综合| 内射一区二区三区四区| 亚洲人成网站18禁止无码| 色爱综合另类图片av| 国产成人无码免费视频在线| 狠狠综合久久综合88亚洲| 精品人妻av区乱码| 国产对白老熟女正在播放| 亚洲高潮喷水无码AV电影| 欧美性猛交xxxx乱大交丰满| 国产福利深夜在线观看| 蜜芽久久人人超碰爱香蕉| 视频二区中文字幕在线| 久久精品国产99国产精品严洲| 中文字幕制服国产精品| 久久久久香蕉国产线看观看伊|