Network analysis uncovers putative genes affecting resistance to tick infestation in Braford cattle skin

ABSTRACT Commitment to the melanocyte lineage is characterized by the onset of expression of the microphthalmia-associated transcription factor (Mitf). This transcription factor plays a fundamental role in melanocyte development and maintenance and seems to be crucial for the survival of malignant melanocytes. Furthermore, Mitf has been shown to be involved in cell cycle regulation and to play important functions in self-renewal and maintenance of melanocyte stem cells. Although little is known about how Mitf regulates these various processes, one possibility is that Mitf interacts with other regulators. Here we show that Mitf can interact directly with β-catenin, the key mediator of the canonical Wnt signaling pathway. The Wnt signaling pathway plays a critical role in melanocyte development and is intimately involved in triggering melanocyte stem cell proliferation. Significantly, constitutive activation of this pathway is a feature of a number of cancers including malignant melanoma. Here we show that Mitf can redirect β-catenin transcriptional activity away from canonical Wnt signaling-regulated genes toward Mitf-specific target promoters to activate transcription. Thus, by a feedback mechanism, Mitf can diversify the output of canonical Wnt signaling to enhance the repertoire of genes regulated by β-catenin. Our results reveal a novel mechanism by which Wnt signaling and β-catenin activate gene expression, with significant implications for our understanding of both melanocyte development and melanoma.

Activation of the Wnt signaling pathway is important for induction of gene expression and cell morphogenesis throughout embryonic development. We examined the subcellular localization of dishevelled, the immediate downstream component from the Wnt receptor, in the embryonic mouse kidney. Using immunofluorescence staining, confocal microscopy, and coimmunoprecipitation experiments, we show that dishevelled associates with actin fibers and focal adhesion plaques in metanephric mesenchymal cells. Stimulation of Wnt signaling leads to profound changes in metanephric mesenchymal cell morphology, including disruption of the actin cytoskeleton, increased cell spreading, and increased karyokinesis. Upon activation of Wnt signaling, dishevelled also accumulates in and around the nucleus. Casein kinase Iε colocalizes with dishevelled along actin fibers and in the perinuclear region, whereas axin and GSK-3 are only present around the nucleus. These data indicate a branched Wnt signaling pathway comprising a canonical signal that targets the nucleus and gene expression, and another signal that targets the cytoskeleton and regulates cell morphogenesis.

Abstract Background: Taodan granules (TDGs), traditional Chinese herbals, are effective in treating psoriasis. However, mechanisms of TDGs remain indistinct. The current study aims to indicate the molecular mechanisms of TDGs in treating psoriasis.Methods: Primarily, transcriptional profiling was applied to identify differentially expression genes (DEGs). The following was that we used Gene Set Enrichment Analysis (GSEA) and Ingenuity Pathway Analysis (IPA) analysis for functional enrichment analysis. Eventually, RT-PCR was performed to validation. Results: The results revealed that TDGs could regulated the Wnt signaling pathway to ameliorate skin lesions of imiquimod (IMQ)-induced psoriatic mouse models. IPA core network associated with Wnt signaling pathways in TDGs for psoriasis was established. Thereinto zeste homolog (EZH) 2, CTNNB1, TP63, and WD repeat domain (WDR) 5 could be considered as upstream genes in the Wnt signaling pathway.Conclusions: The Wnt signaling pathway with these above upstream genes might be potential therapeutic targets of TDGs for psoriasis.