Phospholipase C epsilon mediates cytokine cascade induced by acute disruption of epidermal permeability barrier in mice

Disruption of epidermal barrier is an important trigger in abnormal cutaneous inflammation. Phospholipase C epsilon (PLCε), a Ras/Rap1 effector, is essential for regulating cytokines production in different types of skin inflammation. Our previous studies have demonstrated that elevated expression of PLCε participates in the psoriasis-like inflammation in PLCε overexpressing transgenic mice model, while the reduction in PLCε expression attenuates inflammatory responses in either TPA- or DNFB-induced cutaneous inflammation. Here, we determined the role of PLCε in cutaneous inflammation induced by acute abrogation of epidermal permeability barrier. In comparison to wild type controls, PLCε KO mice exhibited reduced ear swelling and infiltration of granulocytes after tape-stripping. Moreover, expression levels of pro-inflammatory cytokines (IL-1α, IL-1β), chemokines (CXCL-1, CXCL-2, CCL20), and antimicrobial peptides (S100 proteins, MBD3) were lower in PLCε-deficient versus wild type mice. Likewise, expression levels of cytokines and chemokines were also lower in PLCε deficient keratinocytes and fibroblasts following IL-22 stimulation in vitro. Furthermore, knockdown of PLCε with its siRNA decreased expression of IL-1α, CCL20, and S100 proteins, and MBD3 in HEK cultures. Collectively, these results suggested that PLCε mediated cytokine cascade induced by acute barrier disruption. IL-22 is likely the upstream of PLCε-mediated cytokine cascade following acute barrier disruption.     

The PBC domain contains a MEINOX domain: Coevolution of Hox and TALE homeobox genes?

 A recent survey of TALE superclass homeobox genes revealed a new domain upstream of the homeodomain that is conserved between the plant KNOX genes and the animal MEIS genes. At the same time, another paper identified the Drosophila gene homothorax (hth) as a homologue of the vertebrate MEIS genes, which prompted a reexamination of the sequences of the MEIS, KNOX (collectively named MEINOX) and PBC domains. Similarity of the complete MEINOX domain was found within the PBC domain. This suggests that the PBC class genes were also derived from the ancient MEINOX genes. Recently, it has been shown that the MEIS genes can interact with the Abd-B genes, whilst previous results have shown that the PBC genes interact with anterior Hox genes. This leads to the hypothesis that the duplication of an ancestral MEINOX gene into the PBC and MEIS genes happened at a point in time when the first two Hox cluster genes, an anterior one and a posterior one, emerged, and that subsequently these gene classes coevolved. Received: 19 January 1998 / Accepted: 11 February 1998     

Interspersed expression of CUP-SHAPED COTYLEDON2 and REDUCED COMPLEXITY shapes Cardamine hirsuta complex leaf form

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Characterization and developmental expression of AmphiNk2-2, an NK2 class homeobox gene from amphioxus (Phylum Chordata; Subphylum Cephalochordata)

 The genome of amphioxus includes AmphiNk2-2, the first gene of the NK2 homeobox class to be demonstrated in any invertebrate deuterostome. AmphiNk2-2 encodes a protein with a TN domain, homeodomain, and NK2-specific domain; on the basis of amino acid identities in these conserved regions, AmphiNk2-2 is a homolog of Drosophila vnd and vertebrate Nkx2–2. During amphioxus development, expression of Amph- iNk2-2 is first detected ventrally in the endoderm of late gastrulae. In neurulae, endodermal expression divides into three domains (the pharynx, midgut, and hindgut), and neural expression commences in two longitudinal bands of cells in the anterior neural tube. These neural tube cells occupy a ventrolateral position on either side of the cerebral vesicle (the probable homolog of the vertebrate diencephalic forebrain). The dynamic expression patterns of AmphiNkx2-2 suggest successive roles, first in regionalizing the endoderm and nervous system and later during differentiation of specific cell types in the gut (possibly peptide endocrine cells) and brain (possibly including axon outgrowth and guidance). Received: 24 November 1997 / Accepted: 2 February 1998     

Stem cell-based modeling and single-cell multiomics reveal gene-regulatory mechanisms underlying human skeletal development

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Identification of genes influencing formation of the Type III Brush Hair in Yangtze River Delta white goats by differential display of mRNA

Yangtze River Delta white goat is an exclusive indigenous Chinese goat breeds that can produce Brush Hair specialized in making valuable writing brush. The high-grade (Type III) Brush Hair is conical coarse hair but with a tip, which only grows in the cervical carina and back regions of Yangtze River Delta white goats. Screening of genes influencing the formation of Type III Brush Hair was conducted using differential display of mRNA technique in skin including the hair follicles of different goat groups and the differential bands were identified using reverse Northern dot blot, and the positive bands were subsequently cloned and sequenced. The results showed that 20 differentially displayed bands were obtained, seven of which were identified positive as expressed in skin. Three of these seven cDNAs were homologous to certain sequences from GenBank and the other four were respectively homologous to CKLF-like MARVEL transmembrane domain containing 3 (CMTM3), S100 calcium binding protein A4 (S100A4), protein kinase inhibitor gamma (PKIG) and fibulin 1-D. The study would provide a new view to elucidate their roles in hair growth and hair follicle cycle and increase our understanding of the formation of Type III Brush Hair.