It has long been noted that dermabrasion, plum-blossom needling or micro-needling, and even ablative fractional CO 2 laser can effectively induce repigmentation of vitiligo lesions resistant to conventional ultraviolet B phototherapy. In addition to trauma-induced increase in the transdermal absorption of drugs, these treatments also initiate wound repair and activate melanocytes in hair follicles or epidermis. Basal layer keratinocytes, vascular endothelial cells and fibroblasts in the wound margins can secrete chemokine CXCL12 to recruit melanocytes or melanocyte stem cells expressing chemokine receptors CXCR4/CXCR7 in the hair follicle bulge or around the skin lesions to move towards the vitiliginous area. This review summarizes progress in repigmentation of vitiligo lesions induced by therapeutic skin trauma.

Humans ; Melanocytes ; Melanosis ; Fibroblasts ; Skin

Objective:To investigate the expression and distribution of human dermal papillary fibroblasts (Fp) , reticular fibroblasts (Fr) , and myofibroblasts (MFB) in keloid tissues.Methods:Keloid tissues were collected from 15 outpatients (including 8 males and 7 females) aged 20-50 years, who were diagnosed in the Department of Dermatology, Renmin Hospital of Wuhan University from May to December 2019. Normal skin tissues were taken from 15 age-matched women who underwent mammoplasty, and served as controls. The distribution of fibroblast activation protein (FAP) , CD90 and alpha-smooth muscle actin (α-SMA) was observed in the keloid tissues and normal skin tissues by dual immunofluorescence staining. Furthermore, fibroblasts were isolated from 3 normal skin and 3 keloid tissue samples, and subjected to primary culture. Subsequently, the fibroblasts were treated with 10 ng/ml transforming growth factor-β1 (TGF-β1) for 48 hours in vitro, during which, changes in fibroblast phenotypes were observed in the 2 groups. Fluorescence-based quantitative RT-PCR and Western blot analysis were performed to determine the mRNA and protein expression of FAP, CD90 and α-SMA. Measurement data were compared between 2 groups by using t test. Results:Immunofluorescence staining of the normal skin tissues revealed that FAP +/CD90 - fibroblasts were predominantly distributed in the superficial dermis, FAP -/CD90 + fibroblasts in the deep dermis, and CD90 + cells hardly expressed α-SMA; however, a large number of FAP + fibroblasts and CD90 + fibroblasts were observed in the deep keloid tissues, and many CD90 + fibroblasts also expressed α-SMA. Dual immunofluorescence staining showed that normal tissue-derived fibroblasts hardly expressed α-SMA, and keloid-derived fibroblasts expressed α-SMA. The fluorescence intensity of α-SMA + cells significantly increased in the normal tissue-and keloid-derived fibroblasts after 24-hour treatment with TGF-β1 (21.058 ± 0.709, 27.112 ± 0.097, respectively) compared with that in the corresponding untreated fibroblasts (11.312 ± 0.636, 21.306 ± 0.464, t=22.430, 13.370, respectively, both P < 0.05) . RT-PCR and Western blot analysis showed that the mRNA and protein expression of FAP, CD90 and α-SMA significantly increased in the keloid-derived fibroblasts after 48-hour treatment with TGF-β1 (mRNA: 92.610 ± 3.667, 1.366 ± 0.105, 3.240 ± 0.141; protein: 0.652 ± 0.073, 1.046 ± 0.119, 0.946 ± 0.117, respectively) compared with the untreated keloid-derived fibroblasts (all P < 0.05) . Conclusion:CD90 + Fr aberrantly proliferated in the deep dermis of keloid tissues, suggesting that directional intervention in aberrantly proliferating FAP -/CD90 + Fr in the deep dermis may promote the efficacy for keloids.

To construct a eukaryotic expression plasmid containing the luciferase reporter gene (Fluc) to quickly detect apoptosis. Four amino acids, Asp-Glu-Val-Asp (DEVD), the recognize motif of Caspase-3, were introduced into the middle of the Fluc-C and N fragment. Meanwhile, four amino acids, Asp-Glu-Val-Gly (DEVG), were selected as a negative control. Subsequently, the recombinant gene was cloned into the N and C terminal end of the split intein, and named as pFluc-DEVD and pFluc-DEVG. Then the plasmids were transfected into cells and renilla luciferase was co-transfected in each sample as an internal control for transfection efficiency. Then the apoptosis level was detected by the double luciferase reporter gene and the Western blotting analysis. The results showed that when apoptosis occurred, the content of firefly luciferase expressed in the pFluc-DEVD plasmid transfected group was about 3 times higher than pFluc-DEVG plasmid transfected group. Furthermore, Western blotting detection indicated that the Fluc level was significantly increased in pFluc-DEVD transfected group when pre-treated by apoptosis stimulants. The activation degree of Caspase-3 was closely related to the expression of Fluc, and had a significant statistical difference. These results confirmed that firefly luciferase protein expressed by pFluc-DEVD plasmid can be cleaved by the intracellular Caspase-3 enzyme, and this plasmid can accurately reflect the cell apoptosis level, which provides a useful method for quantitative detection of apoptosis.
Apoptosis ; Genes, Reporter ; Luciferases, Firefly ; Transfection