Construction The Animal Model Of K14-VEGF Transgenic Mice

Psoriasis is a chronic inflammatory diease that lead to widespread development oferythematous plaques with adherent silvery scales. The diease is believed to be primarilymediated by T-cell, which release cytokines that stimulate kerationcyte(KC)hyperproliferation and altered differentation. The current understanding of molecularpathogenesis of psoriasis is unknown, most clinical features arise spontaneously only inhuman and closely related primate species. The laboratory mouse offers the most flexibleexperiment system for development of new psoriasisiform phenotypes and previous studieshave described transgenic or deletion mutants with skin conditions that resemblehumanclinical psoriasis. Given the many disparities between human and mouse skin, itcannot be expected that psoriasiform phenotypes in mice wil mirror the human diease inevery respect.An ideal model would realistically recapitulate a marked epidermalhyperproliferation, thickening and altered differention of epidemis, an inflammatoryinfiltrate that include altered vascularity, and responsiveness to current antipsoriatic therapies.The question for study according to records and conditions, seting up the K14-VEGFtransgenic mice in order to be in the service for psoriasis research.Vascular endothelial growth factor (VEGF) is a potent mediator of angiogenesis,prompting recent efforts to therapeutically exploit this factor in conditions involvingpathologically decreased blood flow. Some recent studies,however, have raised concernsabout whether the delivery of VEGF could also have deleterious consequences. Here wemake the surprising observation that chronic transgenic delivery of VEGF to the skin canresult in a profound inflammatory condition with many of the cellular and molecularhallmarks of human psoriasis, such as hyperplastic and inflamed dermal blood vessels,epidermal thickening (termed acanthosis) with aberrant keratinocyte differentiation, andcharacteristic inflammatory infiltrates.Though gateway cloning technology constructs pRP. EX3d-K14> mVEGF164> hGHexpression recombinant vector. The DNA fragment of transgene digested from therecombinant vector by MluⅠ/SalⅠ was transfected to mouse genome to verify theexpression of vascular endothelial growth factor (VEGF) in vitro. Then the transgenefragment was microinjected into fertilized eggs of FVB×FVB mice and transgenic foundermice were generated. The F1mice of K14-VEGF transgenic founder mice were used toidentify the expression of the transgene in geneome.While DNA pronucleus microinjection product the transgenosis mice, the aim gene isonly integrated on one of chromosome in the diploid animal,so it is a long process to choose, purify and gain the homozygote transgenosis mouse. Generally, we can adopt the method ofusing classical breeding combined with PCR for screening of transgenic mice homozygous.Before the homozygous were chose, we should selected group that expressed the higherVEGF than other groups.And then according to the signal integration rate and PCR-Southernof each nest of rats, choose the putative homozygous mice.Analysis of the in flammatory cell infiltrate in3-month-old K14-VEGF mice revealed asignificant increase in both mast cells(as determined by staining for toluidine blue, whichstains mast cell granules) and when compared with wild-type littermate controls. Furtherincreases in mast cells was evident as the animals aged to6months.At around6months ofage, T-cell infiltration with the characteristic CD4distribution in the dermis and CD8in theepidermis. In addition, a histologically very similar condition can be induced in young miceby application of oxazolone on the skin, which causes a hapten-driven inflammation.Therefore the K14-VEGF transgenic mice was constructed with skin conditions thatresemble humanclinical psoriasis, and provided an appropriatable animal model for thepsoriasis pathogenesis and new drugs research.