Role of TGFBIp in Wound Healing and Mucin Expression in Corneal Epithelial Cells

PURPOSE: Transforming growth factor-β-induced protein (TGFBIp) is highly expressed in the cornea, and mutant TGFBIp induces corneal diseases. However, the function of TGFBIp in cornea epithelium is not fully investigated. Here, we tested the importance of TGFBIp in regulation of gene expression and corneal epithelial cell (CEC) activity. MATERIALS AND METHODS: The effect of TGFBIp on CEC activity was analyzed by cell migration, adhesion, proliferation and wound healing assay. Analysis of gene expression was examined by western blot and quantitative reverse transcription PCR. RESULTS: The results demonstrated that TGFBIp increased adhesion, migration, proliferation, and wound healing of CECs. Analysis of gene expression presented that TGFBIp-stimulated CECs exhibited increased expression of mucin family genes, such as MUC1, -4, -5AC, and -16. Furthermore, TGFBIp treatment increased the expression of MUC1, -4, -5AC, -7, and -16 in conjunctival epithelial cells. TGFBIp also increased the activity of intracellular signaling molecules ERK and AKT in CECs. Using pharmacologic inhibitors of ERK and AKT, we showed that the expression of mucin genes by TGFBIp is mediated by the activation of ERK and AKT signaling. CONCLUSION: Our findings demonstrate that the locally generated TGFBIp in the cornea may contribute to wound healing of CECs by enhancing the migration, adhesion, and proliferation of CECs. In addition, our results suggest that TGFBIp has a protective effect on ocular surfaces by inducing the expression of mucin genes in corneal and conjunctival epithelial cells. These data suggest that TGFBIp is a useful therapeutic target for patients with corneal wounds.

Langerhans cell protein 1 (LCP1) binds to PNUTS in the nucleus: implications for this complex in transcriptional regulation

Protein phosphatase-1 (PP1) nuclear targeting subunit (PNUTS), also called PP1R10, p99, or CAT 53 was originally isolated as a mammalian nuclear PP1-binding protein. In this study, we performed yeast two-hybrid screens to identify PNUTS-interacting proteins. Here, we report that LCP1 (epidermal Langerhans cell protein 1), a novel member of the HMG-box protein family, binds tightly to PNUTS. Co-immunoprecipitation of deletion constructs revealed that the C-terminus of LCP1 is sufficient for the interaction with an N-terminal region of PNUTS that is distinct from its PP1-binding domain. Furthermore, immunofluorescence studies showed that a subpopulation of LCP1 co-localizes with PNUTS in nuclear speckles. Importantly, we found that the N-terminus of LCP1 has a strong trans-activation activity in a GAL4-based heterologous transcription assay. The transcriptional activity of LCP1 is markedly suppressed by its interaction with PNUTS, in a PP1-independent manner. These findings suggest that the coordinated spatial and temporal regulation of LCP1 and PNUTS may be a novel mechanism to control the expression of genes that are critical for certain physiological and pathological processes.

The effect of ginsenoside Rk1 in junctional protein of severe preeclamptic placenta / 대한산부인과학회지

OBJECTIVE: To investigate the differential expression of junctional proteins in the normal and preeclamptic human placenta and the effect of ginsenoside Rk1 in junctional proteins. METHODS: Placental tissues from 10 women with severe preeclampsia and 5 normal women were collected at the time of their cesarean section. Five of 10 preeclamptic women were complicated with intrauterine growth restriction (IUGR). Immunohistochemistry and Western blotting was employed to localize junctional proteins (zo-1, occludin and plakoglobin) positive cells. The placental explant culture was performed to investigate if Rk1 can attenuate the expression of junctional proteins (zo-1, occluding and plakoglobin) induced by deferoxamine-induced hypoxia. Rk1 was treated at the day 3 and Western blot analysis was performed for protein quantification. RESULTS: There was no different expression of zo-1 and plakoglobin among all the study groups. Occludin showed negative at the endothelial cells of the terminal villi in both normal and preeclampsia groups. At the endothelial cells of the stem villi, occludin was detected in both normal and severe preeclamptic placenta with normal fetal growth. However, severe preeclampsia with IUGR were decreased expression of occludin at the endothelial cells of the stem villi. When we administered Rk1 to the placenta treated with DFO, expression of occludin was not different. CONCLUSION: The placental expression of zo-1 and plakoglobin were not different among the study groups, while that of occludin was significantly decreased at the endothelium of stem villi in severe preeclampsia with IUGR. Rk-1 showed no effect on the placental junctional proteins. These results suggest that occludin may play a role in pathophysiology of fetal growth restriction in utero.