The magic of the E. coli

The FGF7 main biological function is to promote the proliferation and migration of epithelial cells, inhibition of apoptosis, play an important role in the epithelial tissue injury and repair. Common elevated FGF7 transcriptional level, in the healing process of the kidneys, bladder, intestinal mucosa, cornea and skin damage associated with the relative increase the severity of the injury, when the phase change and wound healing phase match. Through paracrine pathway in skin wound healing process, fibroblasts and expression of the wound edge wound under FGF7 role in the expression of FGFR-2 Ⅲ b epidermis and hair follicle keratinocytes make migration amplification cause of the wound re-epithelialization , so as to promote and complete wound healing. In addition, FGF7 also has a role in the protection of epithelial tissue, skin and hair follicles from damage to the physical and chemical factors.

Fibroblast growth factor 7 (FGF7) is a secreted by the stromal cells than skin cells as target cells, the heparin binding and cytokines, can be used with the specific receptor is located in the epithelial cell surface binding, then cause a series of intracellularsignal transduction and gene expression play an important role in the process of epithelial cell growth, differentiation, migration.With further research, this factor gene nucleotide sequencing, the expression of the protein in the epithelial tissue development and injury prevention, repair, and tumor resistance play an important role in Biology, with attractive value.

A certain dose of exogenous bFGF direct role in the organization of the vascular endothelial cells, promote the proliferation, division and growth, the formation of new blood vessels to connect to accelerate the reconstruction of damaged eardrum tissue microcirculation, improve their blood flow and promote thehealing of traumatic tympanic membrane perforation.

      Cell adhesion molecules are a class of widely distributed on the cell surface or extracellular matrix, mediates cell-cell or cell and matrix Q mutual contact and a combination of a class of molecules, play a role by a receptor ligand corresponding forms, resultingcell-cell and cell matrix or cell-matrix adhesion of cells involved in cell signaling and activation, stretch and move cells, cell growth and differentiation, tumor metastasis, wound healing, and a series of important physiologicaland pathological processes. Hematopoietic cell antigen (human hematopoietic cell antigen, huHCA) and its congeners new discoveries in recent years, a class of cell adhesion molecules, and is a member of the immunoglobulin superfamily, selectively distributed in early hematopoietic cells, the embryonic development of the central nervous system as well as the development of a variety of organizations, the normal growth and development of the nervous system, the hematopoietic cell proliferation, differentiation play an important role.

    1984 Tanaka et _1 J obtained after the immunization of chicken embryonic spinal cord membrane a monoclonal antibody, using this monoclonal antibody screening spine dry found, which corresponds to the unique antigen expression in motor neurons and backplane cell surface. So named it the SC1 (spinal o. Rd) antigen. It first early stage in motor neuron development, and continued until the embryo 7 days motor axons arrive dominated by muscle and begin to form synapses the .1990 Pourouie of _2-hybridoma technique identified a selective expressed in the chicken nervous system with the epithelial cell surface glycoprotein, called BEN. This substance expression in the axon extension in the nervous system plays an important role. The following year, Bums, etc. Similarly by the monoclonal antibody method, identifying fork a chicken cell surface protein, DM-GRASPo for further study of these three substances, three substances were cloned eDNA sequence and analysis of protein structure The results show: the eDNA sequence substantially the same molecular structure, and similar in the way of expression, and thus proved to be the same substance, i.e. BEN / SCI / the DM-the GRASP. Two study groups in the United States in 1992 and 1994, reported the congeners with a similar BEN/SC1/DM-GRASP the mouse, respectively called F84.1 glycoprotein and KG-CAM protein by mAb F84.1 and l1-59 to identify the N-terminal amino acid sequence is basically the same expression in different tissues with a substance were found in the goldfish in the DM-GRASP congeners called neurolin, expressed in the development of retinal ganglion cells. 1997 Uehida serum from rat neural cell lines XKM monoclonal antibody F84.1 identify human bone marrow cells, found that may cross-react with the corresponding antigen, they name huHCA.

    The yeast two-hybrid system is an important method widely used in group study of protein-protein interactions. Its principle is when the target specific binding of protein and the bait protein, the bait protein binding to the promoter of the reporter gene to start the expression of the reporter gene in a yeast cell, If the detected the expression product of the reporter gene, then the difference between each other the role, otherwise there is no interaction between the two. Trace, this technique can be used to study the interaction between the large-scale protein array after. In practical work, the people according to the needs of the development of a single hybrid system, the three-hybrid system and reverse hybrid system. Angermayr designed a SOS-mediated two-hybrid system. Study of membrane proteins, rich yeast two-hybrid system. In addition, the role of the yeast two-hybrid system has been extended to the identification of proteins.

    Mostly endogenous infection, urinary tract infection, such as urethritis, cystitis,pyelonephritis.

    E. coli can also cause peritonitis,cholecystitis, appendicitis. Infants, the frail elderly, chronic wasting disease, a large area of burn patients, E. coli can invade the bloodstream, causing sepsis. Preterm children, especially newborns within 30 days after birth, susceptible to E. coli meningitis.

      Heat-labile enterotoxin (Heatstableenterotoxin, ST): stable to heat to 100 ° C for 20 minutes still be destroyed, a small molecular weight, the weak immunogenicity. ST can activate intestinal epithelial cells guanylate cyclase, increased intracellular cGMP, change the operation of the liquid in the jejunum part of the intestine effusion caused by diarrhea. ST common antigen with cholera toxin.

      Some enterotoxigenic Escherichia coli strains produce only an enterotoxin, LT or ST; Some two can can produce. Some pathogenic E. coli also produce vero toxin.

    E. coli the serotyping basis (ie its antigen) of Escherichia coli are mainly three antigens: O antigen is the outermost layer of the cell wall lipopolysaccharide specific polysaccharide, composed by repeating polysaccharide units. The antigens stimulate the body to produce IgM class antibodies (appeared earlier and disappeared quickly). K antigen, in O antigen outer layer, polysaccharides, and bacterial invasion force. The K antigen divided into A, B, L-type. H antigen in the flagella, heating, and treatment with alcohol, the degeneration or loss of H antigens can. H antigen to stimulate the body to produce antibodies of the IgG class, almost no cross-reactivity with other intestinal bacteria.

    E. coli serotypes O: K: H Ordering example: O111: K58 (B4): H2

      Enterotoxin: enterotoxigenic Escherichia coli exotoxin released in the process of growth and reproduction, is divided into two kinds of heat-resistant and heat-labile. Heat-labile enterotoxin (Heatlabileenterotoxin, LT): the heat-labile, 65 ° C for 30 minutes inactivated. Of protein, and the large molecular weight and immunogenicity. By A, B subunit composition A is divided into A1 and A2, wherein A1 is the active portion of the toxin. B subunit and small intestinal epithelial cell surface GM1 ganglioside receptor binding, the A subunit across the cell membrane adenylate cyclase role of intracellular ATP into cAMP. When cAMP increased the lead to excessive secretion of small intestine liquid exceeds the absorptive capacity of the intestinal diarrhea. The LT's immunogenicity Vibrio cholerae enterotoxin Similar to the cross of both antisera and role.