Two mutations of the KRT6A gene in Chinese patients with pachyonychia congenita type I / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Effects of all-trans retinioic acid and tazarotene on MMP-1 and TIMP-1 expression in cultured human fibroblasts after heat shock / 南方医科大学学报

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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).</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Expressions of fibrillin-1, elastin and matrix metalloproteinase-1 and -9 in chronic actinic dermatitis in elderly patients / 南方医科大学学报

<p><b>UNLABELLED</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Alteration of tazarotene induced gene-2 expression in psoriasis vulgaris / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of tazarotene induced gene-2 (TIG2) in psoriasis vulgaris.</p><p><b>METHODS</b>TIG2 protein and mRNA expressions in normal tissues, psoriatic lesions and uninvolved skin tissues were detected by immunohistochemistry and in situ hybridization, respectively.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>TIG2 may maintain the normal differentiation of epidermal keratinocytes and implicate in the pathogenesis and development of psoriasis vulgaris.</p>

Analysis of the difference in proteome expression between yeast form and mould form of Penicillium marneffei using SELDI technique / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the difference in protome expression between yeast form and mould form of Penicillium marneffei.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>SELDI technique can identify the difference of the expressed low-molecular-mass proteins between the mould form and yeast form of Penicillium marneffei.</p>

Inhibition of promyelocytic leukemia gene by tazarotene in hyperproliferative epidermis of psoriasis / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the mechanism of tazarotene against active psoriasis vulgaris.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>Tazarotene may inhibit abnormal proliferation of keratinocytes through down-regulating PML gene expression in active psoriatic epidermis.</p>

Localization and differentiation of hair follicle stem cells / 中国医学科学院学报

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>HFSC located in outer root sheets can promote hair cycle and differentiate into epidermis in vitro.</p>

Effects of bradykinin on the proliferation, apoptosis and differentiation of human keratinocytes / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of bradykinin (BK) on the proliferation, apoptosis and differentiation of human keratinocyte (HKC) and the underlying mechanisms.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>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.</p>