[Two mutations of the KRT6A gene in Chinese patients with pachyonychia congenita type I].

OBJECTIVE: To investigate the gene mutation in a Chinese pedigree and one sporadic case with pachyonychia congenita type I(PC-1), as well as to explore the relationship between the genotype and phenotype. METHODS: The whole coding region of the KRT16 and KRT6A genes were amplified by long-range polymerase chain reaction (PCR). Six patients with PC-1 were studied, five of them were from a pedigree and the other one was sporadic. One unaffected member in the pedigree and 100 unrelated healthy individuals were also studied in order to exclude polymorphism. PCR products were directly sequenced to detect the mutation. RESULTS: No mutations in the KRT16 gene were observed. All patients harbored a mutation in the KRT6A gene. All five patients in the pedigree had a mutation at codon 465 (TAC to CAC) which substitutes tyrosine (Y) by histidine (H). In the sporadic patient, codon 171 (AAC) was mutated to GAC, which changes the asparagines (N) to aspartic acid (D). No such mutations were found in the unaffected member of the pedigree and the 100 unrelated controls. The mutation of Y465H is located at the end of 2B and N171D at the beginning of 1A domain of KRT6A, both are hotspots for pathogenic keratin mutations. CONCLUSION: The mutations Y465H and N171D of the KRT16A gene were detected in the pedigree and the sporadic case respectively. The Y465H mutation was a novel mutation, and the N171D mutation was reported recently.

[Effects of all-trans retinioic acid and tazarotene on MMP-1 and TIMP-1 expression in cultured human fibroblasts after heat shock].

OBJECTIVE: To investigate the molecular mechanism of dermal damage in heat shock-induced skin aging by observing the expressions of metalloproteinase-1 (MMP-1) and tissue inhibitor of MMP-1 (TIMP-1) in retinoic acid-treated cultured human fibroblasts with heat shock. METHODS: Cultured human fibroblasts were treated with tazarotene or all-trans-retinioic acid (at-RA) after heat shock for 30 min in 43 degrees celsius; water bath. Twenty-four hours later, MMP-1 and TIMP-1 contents in the supernatant of the cell culture medium were measured using enzyme-linked immunosorbent assay (ELISA). RESULTS: Both tazarotene and at-RA dose-dependently reduced the expression of MMP-1 and increased the expression of TIMP-1 in cultured human fibroblasts exposed to heat shock, and tazarotene produced stronger effect than at-RA. CONCLUSION: Retinoic acid can reduce the expression of MMP-1 and increase the expression of TIMP-1 in cultured human fibroblasts, suggesting its therapeutic potential for heat shock-induced skin aging.

[Alteration of tazarotene induced gene-2 expression in psoriasis vulgaris].

OBJECTIVE: To investigate the role of tazarotene induced gene-2 (TIG2) in psoriasis vulgaris. METHODS: TIG2 protein and mRNA expressions in normal tissues, psoriatic lesions and uninvolved skin tissues were detected by immunohistochemistry and in situ hybridization, respectively. RESULTS: TIG2 protein and mRNA were expressed in all the layers of normal and uninvolved epidermis. TIG2 expression was detected in the upper layers of the stratum spinosum of the marginal region of the psoriatic lesions, but not in the central area of the lesions. TIG2 expression was significantly lower in the basal layers of the central area of the paoriasis than that in the normal skin and uninvolved tissues (P < 0.01), and also lower in the marginal regions of the lesions (P < 0.01).The suprabasal layers of the marginal region in the lesion showed significantly lower TIG2 expression than the central area of the lesion (P < 0.01). CONCLUSION: TIG2 may maintain the normal differentiation of epidermal keratinocytes and implicate in the pathogenesis and development of psoriasis vulgaris.

[Expressions of fibrillin-1, elastin and matrix metalloproteinase-1 and -9 in chronic actinic dermatitis in elderly patients].

UNLABELLED: To investigate the expressions of fibrillin-1, elastin and matrix metalloproteinase-1 and -9 (MMP-1, 9) in chronic actinic dermatitis in elderly patients and explore the pathogenesis of the disease. METHODS: Twenty-three patients with chronic actinic dermatitis were examined for the expressions of fibrillin-1, elastin, MMP-1, and MMP-9 with immunohistochemistry in the skin lesions. Image analysis was carried out to measure MMP-1 and MMP-9 expressions semi-quantitatively. RESULTS: In the skin lesions of patients with chronic actinic dermatitis, elastin expression was obviously reduced or absent in the papillary dermis. The elastic fibers were disorderly arranged in the reticular dermis with local aggregation in some regions. Obvious fibrillin-1 deposition was found in the reticular dermis. Increased expressions of MMP-1, but not that of MMP-9, was found in the skin lesions of the patients. CONCLUSION: Elastin and fibrillin-1 deposition can be found in the skin lesions in patients with chronic actinic dermatitis, suggesting the association of increased MMP-1 expression with the elastic tissue degeneration in the lesions. MMP-9 does not exhibit an obvious association with the pathogenesis of chronic actinic dermatitis in elderly patients.

Silencing livin gene by siRNA leads to apoptosis induction, cell cycle arrest, and proliferation inhibition in malignant melanoma LiBr cells.

AIM: The aim of the present study was to investigate the effects of silencing the livin gene by small interfering RNA (siRNA) on the expression of livin and the effects on apoptosis, cell cycle, and proliferation in human malignant melanoma LiBr cells. METHODS: Three chemically-synthetic siRNA duplexes targeting livin were transiently transfected into the LiBr cells, and the effects on livin expression were detected both at the mRNA level by real-time RT-PCR and at the protein level by Western blotting. Apoptosis was evaluated by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling assay, flow cytometric analysis, and the expression of procaspase-3 and activated caspase-3 analysis by Western blotting. Cell cycle was analyzed by flow cytometry. Cell proliferation was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide. RESULTS: One of the 3 designed siRNA could effectively knock down the livin expression both at the mRNA and protein levels in dose- and time-dependent manners; 100 nmol/L with maximum downregulation on mRNA at 48 h, and on the protein at 72 h after transfection. Silencing livin could significantly induce apoptosis, arrest cell cycle at the G0/G1 phase, and inhibit proliferation in LiBr cells. Meanwhile, caspase-3 was activated. CONCLUSION: The livin gene could serve as a potential molecular target for gene therapy by siRNA for malignant melanoma.

[Effects of siRNA on expression of livin and dose- and time-response in human malignant melanoma LiBr cells].

AIM: To investigate the effects of siRNA on expression of livin and dose- and time-response in human malignant melanoma LiBr cells. METHODS: Three chemically synthesized specific siRNAs targeting to livin were transfected to LiBr cells, then the expression of livin was detected both at mRNA level by real-time RT-PCR and at protein level by Western blot, and the effective one was selected for use on observation of dose- and time-response to livin silencing. RESULTS: One of three designed siRNAs could effectively knock down the livin expression both at mRNA and protein levels in dose- and time- dependent manners, 100 nmol/L of which achieved the highest knockdown effect on mRNA at 48 h and on protein at 72 h after transfection. CONCLUSION: Expression of livin in LiBr cells could be efficiently knocked down by siRNA with target site 790-808 of livin mRNA.

[Analysis of the difference in proteome expression between yeast form and mould form of Penicillium marneffei using SELDI technique].

OBJECTIVE: To compare the difference in protome expression between yeast form and mould form of Penicillium marneffei. METHODS: Surface enhanced laser desorption/ionization (SELDI) time-of-flight mass spectra were performed to compare the expressed proteins between yeast form and mould form of Penicillium marneffei. Protein profiling was read by PBSIIC ProteinChip Reader and the proteome database was analyzed by Proteinchip Software 3.2.0. RESULTS: Seventy-five distinct proteins were found in the yeast form and mould form of Penicillium marneffei, in which 10 proteins were up-regulated in yeast form and 3 in mould form. The proteins 2900 and 3151 were only expressed in the yeast form and the proteins 13,151 and 13,285 only in mould form. CONCLUSION: SELDI technique can identify the difference of the expressed low-molecular-mass proteins between the mould form and yeast form of Penicillium marneffei.

[Localization and differentiation of hair follicle stem cells].

OBJECTIVE: To identify the localization of hair follicles stem cell (HFSC) in different stages of hair and explore the differentiating capacity of HFSC into epidermis in vitro. METHODS: HFSC were detected by K19 immunostaining in normal human skin. Then, the isolated HFSC through enzyme digestion were seeded on dermal equivalent (DE) and cultured between the air-liquid interfaces for 14 days. Skin-equivalents was harvested and used for evaluation. RESULTS: HFSC mainly located in outer root sheet in hair follicle and human anagen hair follicles containing two distinct reservoirs for K19-positive cells located in the bulge and bulb of the follicle. These two reservoirs fused in line of outer root sheets during the catagen-telogen transition phase and individualized again in the newly forming anagen hair follicle. Based on DE, growing HFSC built a multilayered and confined epidermis. CONCLUSION: HFSC located in outer root sheets can promote hair cycle and differentiate into epidermis in vitro.

[Inhibition of promyelocytic leukemia gene by tazarotene in hyperproliferative epidermis of psoriasis].

OBJECTIVE: To investigate the mechanism of tazarotene against active psoriasis vulgaris. METHODS: A randomized, controlled trial was conducted in 43 patients with active psoriasis vulgaris, who were divided into tazarotene and control groups. Promyelocytic leukemia (PML) mRNA in active psoriatic lesions before and 14 days after tazarotene treatment was detected by in situ hybridization. RESULTS: PML mRNA expression was detected not only in the basal layer (86.96%), but also in the suprabasal layers of the epidermis in the manner of focal expression (78.26%). After tazarotene treatment, virtually no PML mRNA expression could be detected in the psoriatic lesions (8.69% in the basal layer and 4.35% in the suprabasal layers). PML mRNA expression in the control group underwent no obvious changes during the observation. CONCLUSIONS: Tazarotene may inhibit abnormal proliferation of keratinocytes through down-regulating PML gene expression in active psoriatic epidermis.

[Effects of bcl-2 antisense oligodeoxynucleotide on proliferation and apoptosis of human melanoma A375 cell line].

AIM: To investigate effects of bcl-2 fully phosporothioated antisense oligodeoxynucleotide(bcl-2 ASODN) on proliferation and apoptosis of human melanoma A375 cell, and its possible mechanism. METHODS: Proliferation and apoptosis of A375 cell with bcl-2 ASODN treatment were evaluated by MTT colorimetric assay, laser scanning confocal microscope (LSCM), TUNEL and Annexin V/propidium iodide(PI), and the level of bcl-2 mRNA expression in A375 cell was detected by RT-PCR before and after being treated by bcl-2 ASODN. RESULTS: MTT assay demonstrated that bcl-2 ASODN could inhibit the proliferation of the cells in both time and concentration dependent manner. Characteristic morphologic apoptosis changes were observed by LSCM after incubated with bcl-2 ASODN for 48 h. Most nucleus were labeled in brown by TUNEL in ASODN group, but not markedly labeled both in SODN and control group. The apoptosis rate of A375 cells in 30 micromol/L bcl-2 ASODN group was significantly higher than that in bcl-2 SODN and in control group. The bcl-2 ASODN-induced apoptosis of A375 cells, which was accompanied by declined expression of bcl-2 mRNA was distinctly lower than that in SODN and control groups. CONCLUSION: These results suggest that bcl-1 ASODN can not only inhibit proliferation but also induce apoptosis of human melanoma A375 cells in vitro, and the apoptosis-induced mechanism is down-regulating expression of bcl-2 mRNA.

[Apoptosis induced by curcumin and its effect on c-myc and caspase-3 expressions in human melanoma A375 cell line].

OBJECTIVE: To investigate the effect of curcumin on cell apoptosis and c-myc and caspase-3 expressions in human melanoma A375 cell line. METHODS: A375 cells were exposed to curcumin treatment and growth inhibition of the cells was examined by MTT assay. Annexin V/propidium iodide double staining and DNA fragmentation analysis were employed for assay of the cell apoptosis and morphological changes of the cells were observed with inverted microscopy and transmission electron microscopy, respectively. In situ hybridization and SABC immunohistochemistry were performed for detection of the expressions of c-Myc and caspase-3 in the A375 cells. RESULTS: Curcumin inhibited the growth of A375 cells in both time- and concentration-dependent manners. After treatment with 30 micromol/L curcumin for 48 h, apoptotic morphological changes were observed in the cells and an oligonucleosomal DNA ladder was clearly visualized in DNA fragmentation analysis. The apoptotic rates of the cells treated with curcumin at the concentration above 20 micromol/L were significantly higher than that of the control cells. c-myc expression level was decreased whereas caspase-3 expression increased with the increase in curcumin concentrations. CONCLUSION: Curcumin can inhibit the proliferation and induce apoptosis of A375 cells in vitro, and the genes encoding c-myc and caspase-3 may play a role in the process.

[Effects of histamine on proliferation, apoptosis and differentiation of human keratinocytes].

OBJECTIVE: To investigate the effects of histamine on the proliferation, apoptosis and differentiation of human keratinocytes (HKC) and the mechanisms. METHODS: The effect of histamine on the growth of HKC in vitro was examined by MTT assay and trypan blue exclusion assay. Cell cycle analysis and early apoptosis analysis by double staining with Annexin V-FITC and PI were carried out by flow cytometry. DNA ladder assay was performed for the detection of cell apoptosis. HKC free calcium concentration ([Ca(2+)](i)) was measured by laser scanning confocal microscopy in combination with calcium fluorescence probe Fluo-3/AM. HKC differentiation markers keratin 10 (K10) and involucrin was detected by streptavidinbiotin complex immunocytochemical assay. RESULTS: Histamine at high concentration inhibited the proliferation of HKC with cell viability ratio of 65.6% at 1 x 10(-4) mol/L, while histamine at low concentrations promoted proliferation of HKC with the cell viability ratio of 130.7% at 1 x 10(-8) mol/L. Histamine at 1 x 10(-4) mol/L altered cell cycle distribution of HKC with an increase in G0/G1-phase cell population to 30.97%, a decrease in S-phase population to 73.81% and inhibition of G1/S switching. Histamine at 1 x 10(-4) mol/L induced obvious apoptosis of HKC with early apoptosis ratio of 18.64% as compared with the control (5.60%, P<0.05). Histamine 1 x 10(-4) mol/L induced an increase of HKC [Ca(2+)](i) up to 58.9% and cimetidine (an H(2) receptor antagonist) decreased HKC [Ca(2+)](i) down to 25.4%. Histamine at this concentration down-regulated the expressions of K10 and involucrin of HKC but these changes were not significantly different from those of the control (P>0.05). CONCLUSIONS: Histamine at high concentrations inhibits cell cycle progress of HKC, mediates cell apoptosis and induces the increase of [Ca(2+)](i), which might be a partial explanation for growth arrest of HKC elicited by histamine. Histamine may regulate epidermal tissue turnover under physiological conditions, whereas under pathological circumstances of the skin as in trauma and inflammation, histamine at high concentrations may inhibit the regeneration of epidermis and the differentiation of HKC.

[Effects of bradykinin on the proliferation, apoptosis and differentiation of human keratinocytes].

OBJECTIVE: To investigate the effects of bradykinin (BK) on the proliferation, apoptosis and differentiation of human keratinocyte (HKC) and the underlying mechanisms. METHODS: HKCs were cultured together with 1 x 10(-4) - 1 x 10(-9) mol/L of BK. With methyl thiotetrazole (MTT) and trypan blue staining it was shown that the BK in dose of 1 x 10(-4) mol/L possessed most powerful inhibitory effect, and the survival rate of HKC was 69.3%. Therefore, BK was employed in the dose of 1 x 10(-4) mol/L in the following studies. When the growth of HKCs reached the logarithmic phase, BK in the concentration of 1 x 10(-4) mol/L was added, and it was categorized as the test group (E). HKCs without BK served as the control group (C). The cell cycle and apoptosis were detected by flow cytometry after being cultured for 24 and 48 hours. The change in intracellular calcium [Ca(2+)](i) was determined by means of laser scanning confocal microscopy with calcium fluorescence probe Fluo-3/AM technique. The expression of HKC differentiation labeling protein keratin10 (K10) and involucrin were detected with Strept Avidin-Biotin Complex (SABC) immunocytochemical assay. RESULTS: The cell ratio in G0/G1 phase in E group increased by 34.57% while in S phase decreased by 58.91% in reference to that in C group. The G1/S phase switching of HKCs was obviously inhibited by BK, and apoptosis was stimulated (apoptotic rate of 15.34% in E group vs 5.60% in C group, P < 0.05). The [Ca(2+)](i) increased transiently in HKCs by 163.0% in E group after 3 minutes of BK activation and decreased thereafter in reference to that in C group. The K10 expression in HKC was down-regulated in E group with positive cell rate of 2.20%, which was lower than that of C group (6.89%, P < 0.05). CONCLUSION: The cell cycle process of HKC could be inhibited by high concentration of BK with increased apoptosis and an increase in [Ca(2+)](i), which might be the mechanism of inhibition of growth of HKC in vitro. Furthermore, the epithelial regeneration and HKC differentiation can also be inhibited by BK.

[Effects of all-trans-retinoic acid, acitretin and tazarotene on apoptosis and Bax/Bcl-2 expressions of human melanoma cells A375 and the significance].

OBJECTIVE: To investigate the effects of all-trans retinoic acid (ATRA), acitretin and tazarotene on apoptosis and Bax/Bcl-2 protein expressions of human melanoma A375 cells. METHODS: The effects of retinoids on apoptosis and Bax/Bcl-2 protein expressions of A375 cells in vitro were examined. Apoptosis analysis with double staining with annexin V-FITC and PI was performed using flow cytometer. SABC immunocytochemistry was employed for detection of Bax/Bcl-2 protein expressions. RESULTS: At the concentration of 1 x 10(-5) mol/L, ATRA, acitretin and tazarotene all induced apoptosis of A375 cells with apoptosis ratio of 5.03% (P<0.05), 13.42% (P<0.05) and 2.88% (P>0.05), respectively, and acitretin induced more significant apoptosis than the other two agents (P<0.05). In addition, all the three agents significantly increased the number of cells positive for Bax expression and decreased the number of cells expressing Bcl-2 (P<0.05), among which acitretin had the strongest effects. CONCLUSIONS: ATRA, acitretin and tazarotene mediate apoptosis of A375 cells possibly through, at least partially, the mitochondrial pathway. Acitretin may be utilized as a valuable alternative for treating melanoma.

[Investigation of steroid sulfatase gene in two pedigrees with X-linked ichthyosis].

OBJECTIVE: To investigate the gene mutation in two pedigrees with X-linked ichthyosis (XLI) and explore the relationship between the mutation and clinical manifestations. METHODS: Genomic DNA of the affected and normal members of the pedigrees and 50 unrelated normal subjects from different regions was extracted with a whole blood genomic DNA extraction kit for use of the template for PCR amplification of exon 1, exon 2 and exon 10 of the steroid sulfatase (STS) gene. RESULTS: The STS gene was partially deleted in the affected members in the pedigrees with XLI, leaving only exon 1 but not the other exons. The normal member of the pedigree and 50 unrelated normal subjects had no such deletion. CONCLUSION: Partial deletion of the STS gene exists in the two pedigrees with XLI, which is responsible for pathological skin changes characteristic of XLI.

A novel mutation in the second half of the keratin 17 1A domain in a large pedigree with delayed-onset pachyonychia congenita type 2.

Pachyonychia congenita type 2 (PC-2), also known as Jackson-Lawler type PC, is an autosomal dominant disorder characterized by hypertrophic nail dystrophy associated with focal keratoderma and multiple pilosebaceous cysts. We report a large Chinese pedigree of typical delayed-onset PC-2 that includes 19 affected members. Direct sequencing of PCR products revealed a novel heterozygous 325A-->G mutation in the affected members. This mutation predicts the substitution of asparagine by aspartic acid in codon 109 (N109D) located in the second half of the keratin 17 1A domain, where similar mutation in keratin 5 is associated with the mild Weber-Cockayne form of epidermolysis bullosa simplex.

[A novel keratin 17 gene mutation in a Chinese pedigree of delayed-onset pachyonychia congenita type II].

OBJECTIVE: To detect the keratin 17 gene mutation in a Chinese pedigree of typical delayed-onset pachyonychia congenita type II (PC-II) and to explore the relationship between the genetic mutation and the phenotype of PC-II. METHODS: The DNA was extracted from the blood samples of 19 patients with PC-II in four generations in the pedigree, 1 unaffected member of the pedigree, and 50 un-related normal persons. Nested PCR was used to amplify the mutation hot spot in the exon 1 of keratin 17 gene. The PCR products were directly sequenced to detect the mutation. RESULTS: Sequencing of the PCR products revealed that the codon 109 (AAC) was mutated as GAC in the nine affected members of the pedigree, causing the substitution of asparagine by aspartic acid in codon 109 (N109D) located in the 1A domain of keratin 17 gene. No such mutation was found in the unaffected member of the pedigree and the 50 unrelated controls. CONCLUSION: The novel missense mutation (N109D) located in the second half of 1A domain of keratin 17 gene underlies the affected members' phenotype, delayed-onset pachyonychia congenita type II.