During a search for keratinocyte differentiation-related genes, we obtained a cDNA fragment from the 5'-untranslated region of a previously identified splicing variant of desmoglein 3 (Dg3). This transcript encodes a protein of 282 amino acids, which corresponds to the N-terminal truncated intracellular domain of Dg3 (Delta NDg3). Northern blot analysis detected a 4.6-kb transcript matching the predicted size of Delta NDg3 mRNA, and Western blot analysis with an antibody raised against the Dg3 C-terminus (H-145) detected a 31-kDa protein. Increased Delta NDg3 expression was observed in differentiating keratinocytes by RT-PCR and Western blot analysis, suggesting that Delta NDg3 is indeed a differentiation-related gene product. In immunohistochemical studies of normal and pathologic tissues, H-145 antibody detected the protein in the cytoplasm of suprabasal layer cells, whereas an antibody directed against the N-terminal region of Dg3 (AF1720) reacted with a membrane protein in the basal layer. In addition, Delta NDg3 transcript and protein were upregulated in psoriatic epidermis, and protein expression appeared to increase in epidermal tumors including Bowen's disease and squamous cell carcinoma. Moreover, overexpression of Delta NDg3 led to increased migration and weakening of cell adhesion. These results suggest that Delta NDg3 have a role in keratinocyte differentiation, and that may be related with tumorigenesis of epithelial origin.
Cell Adhesion ; *Cell Differentiation ; Cell Movement ; Cells, Cultured ; Desmoglein 3/*genetics/*metabolism ; Epidermis/cytology ; Gene Expression ; Humans ; Keratinocytes/*cytology ; Skin Diseases/genetics/metabolism ; gamma Catenin/metabolism

This paper aimed to investigate the effect of total flavonoids of buckwheat flower and leaf on myocardial cell apoptosis and Wnt/β-catenin/peroxisome proliferator-activated receptor γ(PPARγ) pathway in arrhythmic rats. SD rats were randomly divided into a control group, a model group, a low-dose(20 mg·kg~(-1)) group of total flavonoids of buckwheat flower and leaf, a medium-dose(40 mg·kg~(-1)) group of total flavonoids of buckwheat flower and leaf, a high-dose(80 mg·kg~(-1)) group of total flavonoids of buckwheat flower and leaf, a propranolol hydrochloride(2 mg·kg~(-1)) group, with 12 rats in each group. Except the control group, rats in other groups were prepared as models of arrhythmia by sublingual injection of 1 mL·kg~(-1) of 0.002% aconitine. After grouping and intervention with drugs, the arrhythmia, myocardial cells apoptosis, myocardial tissue glutathione peroxidase(GSH-Px), catalase(CAT), malondialdehyde(MDA), serum interleukin-6(IL-6), prostaglandin E2(PGE2) levels, myocardial tissue apoptosis, and Wnt/β-catenin/PPARγ pathway-related protein expression of rats in each group were measured. As compared with the control group, the arrhythmia score, the number of ventricular premature beats, ventricular fibrillation duration, myocardial cell apoptosis rate, MDA levels in myocardial tissues, serum IL-6 and PGE2 levels, Bax in myocardial tissues, and Wnt1 and β-catenin protein expression levels increased significantly in the model group, whereas the GSH-Px and CAT levels, and Bcl-2 and PPARγ protein expression levels in myocardial tissues reduced significantly. As compared with the model group, the arrhythmia score, the number of ventricular premature beats, ventricular fibrillation duration, myocardial cell apoptosis rate, MDA leve in myocardial tissues, serum IL-6 and PGE2 levels, Bax in myocardial tissues, and Wnt1 and β-catenin protein expression levels reduced in the drug intervention groups, whereas the GSH-Px and CAT levels and Bcl-2 and PPARγ protein expression levels in myocardial tissues increased. The groups of total flavonoids of buckwheat flower and leaf were in a dose-dependent manner. There was no significant difference in the levels of each index in rats between the propranolol hydrochloride group and the high-dose group of total flavonoids of buckwheat flower and leaf. The total flavonoids of buckwheat flower and leaf inhibit the activation of Wnt/β-catenin pathway, up-regulate the expression of PPARγ, reduce oxidative stress and inflammatory damage in myocardial tissues of arrhythmic rats, reduce myocardial cell apoptosis, and improve the symptoms of arrhythmia in rats.
Rats ; Animals ; PPAR gamma/metabolism* ; Fagopyrum/genetics* ; Rats, Sprague-Dawley ; bcl-2-Associated X Protein ; beta Catenin/metabolism* ; Interleukin-6 ; Flavonoids/pharmacology* ; Propranolol/pharmacology* ; Ventricular Fibrillation ; Dinoprostone ; Wnt Signaling Pathway ; Plant Leaves/metabolism* ; Flowers/metabolism* ; Apoptosis ; Cardiac Complexes, Premature

BACKGROUNDArrhythmogenic right ventricular cardiomyopathy (ARVC) is a heritable cardiac disease predominantly caused by mutations in desmosomal protein genes. Previous genetic analyses of the Chinese ARVC population are limited to small size and restriction to a single gene. This study was aimed to investigate the genotype in a large series of Chinese patients with ARVC through comprehensively screening nine ARVC-causing genes.

METHODSA total of 100 unrelated ARVC patients and 300 age, gender and ethnicity matched healthy controls were genetically tested with multiplexing targeted resequencing for nine previously reported ARVC-causing genes, including plakophilin-2, desmoplakin, desmoglein-2, desmocollin-2, plakoglobin, transforming growth factor beta-3, transmembrane protein 43, desmin and Lamin A/C.

RESULTSFifty-nine mutations were identified in 64% of the patients, among which, 93% were located in desmosomal protein genes. Plakophilin-2 mutations accounted for 54% of the total and 58% of the desmosomal mutations, with a truncating mutation type making up about 2/3 of the plakophilin-2 mutations. Only four mutations were found in non-desmosomal genes; two in transmembrane protein 43 and two in transforming growth factor beta-3. Two of them (one of each gene) appeared as single missense mutations. No mutation was identified in desmin or Lamin A/C. Multiple mutations were found in 23% of the patients, with plakophilin-2 being found in 57% of the multi-mutation carriers.

CONCLUSIONSPlakophilin-2 was the most common gene mutation that was identified in Chinese ARVC patients. Non-desmosomal genes should be added to desmosomal protein genes when performing molecular genetic screening in patients with suspected ARVC.

Adult ; Arrhythmogenic Right Ventricular Dysplasia ; genetics ; metabolism ; Asian Continental Ancestry Group ; Desmin ; genetics ; Desmoglein 2 ; genetics ; Female ; Humans ; Male ; Middle Aged ; Mutation ; Plakophilins ; genetics ; Young Adult ; gamma Catenin ; genetics

OBJECTIVETo investigate the effect of irradiated human lung fibroblasts (HLFs) on the canonical Wnt/β-catenin signaling pathway in human umbilical cord mesenchymal stem cells (HUMSCs).

METHODSHUMSCs were cultured alone (single group) or co-cultured with HLFs exposed to 5Gy X-rays (co-culture group). The protein levels of GSK-3β, p-GSK-3β, FRAT1 and β-catenin in HUMSCs were examined by Western blotting 3 days after culture or co-culture. WISP-1 protein levels in conditioned medium were examined by ELISA.

RESULTSThe levels of p-GSK3β/GSK3β (0.15 ± 0.05), FRAT1 (0.48 ± 0.07) and β-catenin (0.50 ± 0.07) in co-cultured HUMSCs significantly decreased compared to those in single group (0.55 ± 0.05, 1.16 ± 0.13 and 2.39 ± 0.15, all P<0.05). The supernatant level of WISP-1 in co-culture group was significantly decreased [(602.23 ± 161.47) ng/mL], compared to the single group [(977.77 ± 110.56) ng/mL, P<0.05].

CONCLUSIONIrradiated HLFs attenuate the activation of canonical Wnt/β-catenin signaling pathway in HUMSCs in vitro.

CCN Intercellular Signaling Proteins ; metabolism ; Cells, Cultured ; Coculture Techniques ; Fibroblasts ; cytology ; radiation effects ; Gamma Rays ; Glycogen Synthase Kinase 3 ; metabolism ; Glycogen Synthase Kinase 3 beta ; Humans ; Intracellular Signaling Peptides and Proteins ; metabolism ; Mesenchymal Stromal Cells ; metabolism ; Proto-Oncogene Proteins ; metabolism ; Umbilical Cord ; cytology ; Wnt Signaling Pathway ; X-Rays ; beta Catenin ; metabolism