Tight junction (TJ) is recognized as a second barrier of the skin. Altered expression of TJ proteins in various skin diseases characterized by the abnormal permeability barrier such as psoriasis suggests that TJ could be affected by stratum corneum (SC) barrier status. However, the physiological relationship between SC and TJ barrier remains to be investigated. Therefore, we examined the effect of SC barrier disruption on the expression of TJ proteins, claudin (Cldn)-1 and Cldn-4, and TJ barrier function in hairless mouse skin. We also investigated whether the alterations in epidermal Ca2+ affected TJ proteins expression in vivo. Repeated tape-stripping induced a sequential change of the expression and function of TJ. As early as 15-30 minutes after tape-stripping, downregulation of Cldn-1 and Cldn-4 immunoreactivity and protein level without change in mRNA level was found. This was accompanied by the abnormal leakage of lanthanum. However, by 1 hour Cldn-1 and Cldn-4 immunolocalization recovered along with normalized lanthanum permeation pattern. Moreover, the mRNA and protein levels of Cldn-1 and Cldn-4 were increased by 1 to 6 hours after tape-stripping. Inhibition of calcium loss by immersion of barrier-disrupted skin into a high Ca2+ solution prevented the dislocation of Cldn-1 and Cldn-4. Occlusion of barrier-disrupted skin delayed the restoration of Cldn-1 and Cldn-4. Our results suggest that the alteration of epidermal Ca2+ gradient caused by SC barrier perturbation affects the TJ structure and function and the faster recovery of TJ as compared to the SC barrier may imply the protective homeostatic mechanism of skin barrier.
Animals ; Calcium/*metabolism ; Claudin-1/genetics/*metabolism ; Claudin-4/genetics/*metabolism ; Epidermis/metabolism/*physiology ; Female ; Gene Expression Regulation ; Mice ; Mice, Hairless ; Permeability ; RNA, Messenger/metabolism ; Tight Junctions/metabolism/*physiology

OBJECTIVE: To determine the screening of the expression of membrane proteins in androgen-dependent prostate cancer (ADPC) and androgen-independent prostate cancer (AIPC) and to explore the mechanism of membrane proteins in these two cancers. METHODS: Serum samples were collected from 3 patients with ADPC and another 3 patients with AIPC. The serum was incubated with ADPC cell line LNCaP and/or AIPC cell line PC-3 and detected by immunoprecipitation and Western blot. Differentially expressed proteins between ADPC and AIPC identified by mass spectrometry were compared and their expression level and location were analyzed by immunofluorescence. RESULTS: Altogether 11 membrane proteins were identifited, such as the Neural-Cadherin precursor, ER60 precursor, Claudin-4, and so on. Immunofluorescence revealed that the expression level of Claudin-4 in PC-3 cells was higher than in LNCaP cells. CONCLUSION We can use the screening method to study membrane proteins in prostate cancer. Claudin-4 may play an important role in the pathogenesis and the development of AIPC.
Aged ; Androgens ; genetics ; metabolism ; Cell Line, Tumor ; Claudin-4 ; genetics ; metabolism ; Gene Expression Profiling ; Humans ; Male ; Membrane Glycoproteins ; genetics ; metabolism ; Prostatic Neoplasms ; genetics ; metabolism ; pathology ; Protein Disulfide-Isomerases ; genetics ; metabolism

OBJECTIVEThe aim of this study was to explore the possibility of creating a toxin, C-CPE-ETA', by fusing C-terminal high affinity binding domain of CPE (C-CPE) with a truncated form of Pseudomonas aeruginosa exotoxin A (ETA') and to examine whether C-CPE-ETA' could specifically target CLDN-3, 4 molecule and the targeted toxin was cytotoxic against CLDN-3,4-overexpressing ovarian cancer.

METHODSCLDN-3 and CLDN-4 expressions were analyzed at the mRNA level in three ovarian cancer cell lines and epithelial ovarian cancer tissues from 20 patients. After transforming an expression plasmid of C-CPE-ETA' into E. coli BL21 (DE3) plysS strain, the recombinant protein was purified using His-Bind resin chromatography column and analyzed by Western blot and Coomassie blue staining. The specific binding, proapoptotic and cytolytic activities were evaluated by flow cytometry, fluorescence microscopy with the JC-1 probe and MTT assay in CLDN-3,4-overexpressing ovarian cancer cells.

RESULTSQuantitive RT-PCR results showed there existed high levels of CLDN-3 and CLDN-4 in ovarian cancer cells, CAOV3, OVCAR3 and SKOV3. Moreover, high expressions of CLDN-3 and CLDN-4 were observed in 90.0% (18/20) and 60.0% (12/20) of ovarian cancer tissues, with an expression level 10-fold higher than that in the normal ovarian tissue. A 58 000 recombinant protein C-CPE-ETA' was demonstrated by Western blot and Coomassie blue staining. Purified and recombinant C-CPE-ETA' was bound with high affinity to CLDN-3,4-overexpressing ovarian cancer cells, CAOV3, OVCAR3 and SKOV3 cells. C-CPE-ETA' was strongly proapoptotic and cytotoxic towards the CLDN-3,4-overexpressing ovarian cancer cells. The concentration of IC(50) was 7.364 ng/ml for CAOV3 cells, 8.110 ng/ml for OVCAR3 cells and 22.340 ng/ml for SKOV3 cells, respectively. However, control CLDN-3,4-deficient cell line HUVEC was not susceptible to the recombinant C-CPE-ETA' at a concentration up to 10 µg/ml.

CONCLUSIONSThe C-CPE-ETA' protein exhibits remarkably specific cytotoxicity for CLDN-3,4-overexpressing ovarian cancer cells. Its therapeutic potential warrants further development for ovarian cancer molecular targeted therapy.

ADP Ribose Transferases ; metabolism ; physiology ; Apoptosis ; Bacterial Toxins ; metabolism ; Cell Line, Tumor ; Claudin-3 ; Claudin-4 ; Claudins ; genetics ; metabolism ; Enterotoxins ; metabolism ; physiology ; Exotoxins ; metabolism ; physiology ; Female ; Humans ; Immunotoxins ; metabolism ; Ovarian Neoplasms ; metabolism ; pathology ; RNA, Messenger ; metabolism ; Recombinant Fusion Proteins ; metabolism ; physiology ; Virulence Factors ; metabolism ; physiology

OBJECTIVE: To investigate the expression of claudin 4 (CLDN4) in cervical tissues from patients with different cervical lesions, and to explore the value of combined detection of CLDN4 and high risk human papilloma virus (HR-HPV). METHODS: The cervical tissue specimens of low-grade squamous intraepithelial lesion (LSIL, =30), high-grade squamous intraepithelial lesion (HSIL, =30), squamous cell carcinoma (SCC, =30) as well as chronic cervicitis (control, =30) were collected from the Sir Run Run Shaw Hospital of Zhejiang University during June 2015 and December 2016. The expression of CLDN4 protein in tissue specimens was detected by immunohistochemistry, HR-HPV was detected by real-time quantitative PCR, and the cervical exfoliated cells were examined by thinprep cytologic test (TCT). The ROC curve was applied to analyze the diagnostic value of TCT combined with HR-HPV and CLDN4 combined with HR-HPV tests for HSIL and SCC of the cervix. RESULTS: With the increase of the severity of cervical lesions, the positive rate of CLDN4 expression rose (=0.832, <0.05). Positivity of both HR-HPV infection and CLDN4 expression was found mainly in the HSIL and SCC groups. The areas under curve (AUC) of TCT combined with HR-HPV and CLDN4 combined with HR-HPV tests for diagnosis of HSIL and SCC were 0.683 and 0.633, respectively; the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of TCT combined with HR-HPV test for diagnosis of HSIL and SCC were 100.0%, 36.7%, 61.2%, 100.0% and 46.7% respectively; those of CLDN4 combined with HR-HPV test were 96.7%, 30.0%, 58.0%, 90.0% and 55.0%, respectively. CONCLUSIONS CLDN4 expression may be related to the occurrence and development of cervical carcinoma and precancerous lesions. CLDN4 combined with HR-HPV test may be used for diagnosis of HSIL and SCC of the cervix clinically.
Carcinoma, Squamous Cell ; diagnosis ; virology ; Cervical Intraepithelial Neoplasia ; diagnosis ; virology ; Claudin-4 ; genetics ; metabolism ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Immunochemistry ; Papillomaviridae ; isolation & purification ; Real-Time Polymerase Chain Reaction ; Squamous Intraepithelial Lesions of the Cervix ; virology ; Uterine Cervical Neoplasms ; diagnosis

OBJECTIVETo investigate the expressions of prostate stem cell antigen (PSCA) and Claudin-4 in human pancreatic carcinoma and to discuss its role in the ontogenesis of pancreatic cancer.

METHODSPancreatic carcinoma tissue microarray was constructed, containing 100 cores of 10 normal adult pancreas tissues, 12 chronic pancreatitis tissues, and 78 pancreatic carcinomas. The expressions of PSCA and Claudin-4 were detected using immunohistochemical method and the relationship between PSCA and Claudin-4 and the pancreatic carcinoma was analyzed.

RESULTSThe positive expression rates of PSCA and Claudin-4 protein in pancreatic carcinoma were 79. % and 88. % respectively. PSCA and Claudin-4 staining were more intense in malignant cells than in chronic pancreatic tissues and normal adult pancreas tissues. No evidence was found for an association between expressions of PSCA and Claudin-4 and other variables, including gender, age at surgery, and tumor grade.

CONCLUSIONSThe expressions of PSCA and Claudin-4 are related to the pancreatic carcinomas. PSCA and Claudin-4 play a role in the development of pancreatic cancer, but PSCA and Claudin-4 are not correlated with the clinical pathology of tumor.

Adult ; Aged ; Antigens, Neoplasm ; Carcinoma ; genetics ; metabolism ; pathology ; Claudin-4 ; Female ; GPI-Linked Proteins ; Gene Expression Regulation, Neoplastic ; Humans ; Male ; Membrane Glycoproteins ; genetics ; metabolism ; Membrane Proteins ; genetics ; metabolism ; Middle Aged ; Neoplasm Proteins ; genetics ; metabolism ; Pancreatic Neoplasms ; genetics ; metabolism ; pathology ; Up-Regulation