Changes of filaggrin and its gene in patients with ichthyosis vulgaris / 中华皮肤科杂志

Objective To detect mutations in the filaggrin (FLG) gene and expressions of FLG and loricrin in patients with ichthyosis vulgaris (Ⅳ),and to investigate their clinical significance.Methods Tissue specimens were resected from the skin lesions of 10 patients with Ⅳ and normal skin of 14 healthy human controls,and immunohistochemical SP method was used to detect the expressions of filaggrin and loricrin.The expression intensity was determined by the Image-Pro Plus (IPP) software,and expressed as positive units (PU).Blood samples were collected from 10 patients of Han nationality with Ⅳ and 100 healthy human controls followed by DNA extraction.PCR and DNA sequencing were performed to detect the presence of 13 mutations (3321delA,441delA,1249insG,E1795X,S3296X,R501X,2282de14,R2447X,S2889X,7945delA,3702delG,Q2417X,R4307X) in the FLG gene.Results FLG was mainly expressed in the cytoplasm of keratinocytes in the stratum corneum,granular layer,prickle layer and basal layer,and loricrin was observed in the cytoplasm and nuclei of keratinocytes in the granular layer,prickle layer and basal layer,in both the lesional and normal skin.Compared with the normal skin,the lesional skin showed significantly weaker expressions of FLG (0.208 2 ± 0.008 0 vs.0.230 0 ± 0.0228,t =3.30,P ＜ 0.01) and loricrin (0.137 0 ± 0.011 2 vs.0.149 3 ± 0.007 3,t =3.07,P ＜ 0.01).Sequencing analysis identified two mutations,including 3321delA in 7 patients and 441delA in 2 patients.No mutations were detected in the healthy controls.Conclusions The 3321delA and 441delA mutations in the FLG gene may represent the most frequent genetic cause of Ⅳ in patients of Han nationality.The low expressions of FLG and loricrin may be associated with the impairment of skin barrier function in patients with Ⅳ.

Effects of sodium arsenite on mRNA transcription of keratinizing related and nuclear factor E2-related factor 2 genes in HaCaT cells / 中国地方病学杂志

Objective To observe the influences of different doses of sodium arsenite on mRNA transcription of keratinizing related and nuclear factor E2-related factor 2(Nrf2) genes in HaCaT cells.Methods Cell proliferation was evaluated by Cell Counting Kit-8(CCK-8) assay after the HaCaT cells were exposed to 0.00,3.13,6.25,12.50,25.00,50.00,75.00,100.00 μ mol/L sodium arsenite for 48 h,respectively.Based on the previous results of cell proliferation,0.00(control),6.25,12.50,and 25.00 μmol/L of sodium arsenite were selected to treat HaCaT cells for 48 h,respectively.The mRNA expression of keratin 1,keratin 10,involucrin,loricrin and Nrf2 were detected by real-time fluorescent quantitative PCR.ResultsCompared with the control group (100.05％),HaCaT cell proliferation rates(83.06％,51.04％,39.52％,24.51％,16.99％ and 9.04％) were significantly lower in 6.25,12.50,25.00,50.00,75.00 and 100.00 μ mol/L of sodium arsenite groups and the 50％ inhibiting concentration was 12.38 μmol/L.Compared with the control group( 1.06 ± 0.28,1.00 ± 0.12,1.00 ± 0.08),the mRNA expression of keratin 1,involucrin and loricrin (0.08 ± 0.04,0.13 ± 0.12,0.05 ± 0.03;0.47 ± 0.11,0.21 ± 0.09,0.10 ± 0.15; 0.50 ± 0.27,0.31 ± 0.10,0.57 ± 0.23) were significantly decreased(all P ＜ 0.05) in HaCaT cells treated with 6.25,12.50,25.00 μmol/L sodium arsenite,respectively.But keratin 10 mRNA expression showed a rise trend and the 6.25 μmoL/L sodium arsenite group (1.83 ± 0.45) was significantly higher than that of the control( 1.07 ± 0.14,P ＜ 0.05 ).The Nrf2 mRNA expressions of HaCaT cells in 12.50,25.00 μmol/L sodium arsenite groups(0.13 ± 0.07,0.69 ± 0.33) were significantly lower than that of the control ( 1.00 ± 0.09,all P ＜ 0.05 ).ConclusionsThe cellular proliferation and keratinization are decreased when HaCaT cells are exposed to sodium arsenite,which may be regulated by lowering Nrf2 mRNA transcription.

The Effects of Testosterone on Skin Barrier / 대한피부과학회지

BACKGROUND: Although there are no known gender-related differences in permeability barrier function in adults, estrogen accelerates whereas testosterone retards barrier development in fetal skin. However, there have been few studies concerning the effects of testosterone on the skin barrier. OBJECT: We evaluated the effects and mechanisms of testosterone on the skin barrier. METHODS: In this experiment, hairless mice were divided into three groups; sham-operated, castrated and testosterone-replacement castrated group. Testosterone was administered subcutaneously once a day for 7 days. We performed a skin biopsy at 7 days and performed hematoxyline-eosin staining, calcium-ion capture cytometry and the immunohistochemical examination of involucrin, loricrin, filaggrin and proliferating cell nuclear antigen (PCNA). The specimens were prepared for electron microscopy using RuO4 and OsO4 postfixation. RESULTS: The results were summarized as follows 1. Light microscopic findings of the testosterone-replacement castrated group showed apparent hyperkeratosis and acanthosis, not present in the sham-operated and castrated group. 2. Whereas the expression of involucrin, loricrin and filaggrin of immunohistochemical staining and in situ hybridization of the sham-operated and castrated group were normal, it was abnormal in the testosterone-replacement castrated group. 3. Labelling indices for PCNA in the sham-operated and castrated group were not statistically different, but the testosterone-replacement castrated group showed a marked increase of PCNA labeling index. 4. Wherease the calcium gradient was normal in the sham-operated and castrated group, it was distorted in the testosterone-replacement castrated group. Calcium deposition was increased through all layers of the epidermis and the calcium gradient disappeared in the testosterone-replacement castrated group. 5. Normal looking membrane structure was observed in the sham-operated and castrated group, but a membrane structure which appeared fragmented, incomplete lipid bilayer structures and prominent dilatation of lacunar domains were observed only in the testosterone-replacement castrated group. CONCLUSION: From the above results, it is concluded that there is a functional alteration of the epidermal barrier induced by testosterone, including the formation of an abnormal cornified envelope and also incomplete lipid synthesis.

Immunohistochemical Study of Expression of Involucrin, Loricrin, Filaggrin and Bcl-2 in Psoriasis / 대한피부과학회지

BACKGROUND: The pathogenesis of psoriasis remains uncertain. It is known that a variety of factors take a role in its pathogenesis. One of them is the alteration of keratinocytes differentiation. The terminal differentiation of keratinocytes includes the process of the synthesis of proteins such as involucrin, filaggrin, loricrin and cornifin, and produce keratohyaline granules and a structure termed cornified cell envelope finally. And the terminal differentiation of keratinocytes is known as a process of apoptosis, programmed cell death. OBJECTIVE: In this study, we tried to clarify the pathogenetic mechanisms of psoriasis by comparing the expression patterns of several proteins(involucrin, loricrin, filaggrin) associated with keratinocyte differentiation and of bcl-2 protein, known as inhibitor of apoptosis, between lesional and non-lesional psoriatic skin. RESULTS: The results were summarized as follows, firstly early expression of involucrin in lower epidermis, secondly no or reduced expression of filaggrin and loricrin in upper epidermis and lastly no expression of bcl-2 in basal layer of psoriatic skin. CONCLUSION: This study clarified that the accelerated terminal differentiation, the shortening of cell-cycle of keratinocytes, and the increased turnover of keratinocytes may be involved in the pathogenetic role of psoriasis.