Project description:RNA sequencing data of mouse epidermis isolated from wild type and LAMA3-deficient mice Genetic, clinical and biochemical studies concurred to establish that integrity of the dermal-epidermal junction requires laminin 332, a particular subset of epithelial laminins. Laminin 332 is composed of three subunits, α3, β3 and γ2, encoded by the Lama3, Lamb3 and Lamc2 genes, respectively. In vivo functional analysis of laminin 332 in skin has been prevented because constitutive mutations of any one of the coding genes, either inherited in human or engineered in mice, cause junctional epidermolysis bullosa and early death. Consequently, it is still unknown whether and how laminin 332 contributes to skin homeostasis. To circumvent the problem, we have generated a mouse model in which disruption of the Lama3 gene is conditional and specifically induced in epidermal keratinocytes after birth. It causes a progressive depletion of laminin 332 in the skin of the mouse, which is compatible with life. To assess how laminin 332 supervises epidermal homeostasis, RNA was prepared from keratinocytes isolated from laminin 332-depleted skin and control animals (three each) to compare their gene expression profiles using RNA sequencing.
Project description:While antibodies in bullous pemphigoid (BP) are known to activate innate immune response, their direct effect on keratinocytes and the overall contribution of keratinocytes to disease pathogenesis is largely unknown. We sought to understand the mechanism of keratinocyte response to autoantibodies in BP. We affinity purified IgG from patients with a known diagnosis of bullous pemphigoid or healthy controls, and performed bulk RNA-seq. We identified numerous differentially expressed genes including upregulation of CXCL16, IL-24, and TGFB1 in BP-IgG treated keratinocytes
Project description:While antibodies in bullous pemphigoid (BP) are known to activate innate immune response, their direct effect on keratinocytes and the overall contribution of keratinocytes to disease pathogenesis is largely unknown. We sought to understand the mechanism of keratinocyte response to autoantibodies in BP. We affinity purified IgG from patients with a known diagnosis of bullous pemphigoid or healthy controls, and performed bulk RNA-seq. We identified numerous differentially expressed genes including upregulation of CXCL16, IL-24, and TGFB1 in BP-IgG treated keratinocytes
Project description:Intravenous immunoglobulin (IVIg) is used to treat mucous membrane pemphigoid (MMP), although its therapeutic effectivity is not sufficiently supported by randomized controlled clinical trials and its mode of action is only insufficiently understood. We have examined the effect of IVIg in a mouse model of anti-laminin 332 MMP and found that IVIg ameliorates both cutaneous and mucosal inflammatory lesions. Our investigation into the modes of action of IVIg in MMP indicated effective antiinflammatory mechanisms beyond the enhanced degradation of IgG mediated through inhibition of the neonatal Fc receptor. Our results suggest that IVIg curbs the activation of neutrophils at several levels. This includes a direct, immediate inhibitory effect on neutrophil activation by immune complexes but not C5a which blunts the release of reactive oxygen species and leukotriene B4 from neutrophils. IVIg also suppresses the formation of neutrophil extracellular traps in response to Ca2+ ionophore. In vivo treatment with IVIg altered the transcriptome of blood leukocytes and bone marrow neutrophils towards less proinflammatory phenotypes. Collectively, our results support the effectivity of IVIg in the treatment of MMP and indicate that effects on neutrophils at multiple levels may significantly contribute to its therapeutic effects.
Project description:Gene-level analysis of gene expression in immortalized mouse keratinocyte lines that express or lack integrin alpha3beta1 The laminin-332-binding integrin alpha3beta1 is expressed highly in the epidermis, but its roles in regulating gene expression programs that promote normal or pathological skin remodeling have not been underexplored previously. In order to identify genes that are regulated by alpha3beta1 in keratinocytes, we used microarray approaches to identify alpha3beta1-dependent genes in mouse keratinocytes that were immortalized with SV40 large T antigen (i.e., MK cells).
Project description:Developing an effective xeno-free and defined system for human keratinocyte culture has been one of the fundamental measures in current cellular therapy. For keratinocytes, in particular, such system will not only fulfill clinical safety and quality criteria, it will allow for the management of less severe burns and other skin injuries such as chronic wounds. To date, the expansion of autologous keratinocytes in the clinical settings still relies on 3T3 feeder co-culture system. Here we report a completely xeno-free and defined culture system by using human recombinant laminins as feeder replacement. We have thoroughly characterized the cells cultured in this new system both in vitro and in vivo. We found that laminin-511/-521, and the unanticipated laminin-411/-421, but not -332, -111, -121, -211, or LN-221 support adult human skin keratinocytes and could maintain their self-renewal properties comparable to the 3T3 system. We believe our new culture method should facilitate broader use of cultured epithelial cell products for today’s regenerative medicine.