Role of endothelin-1 in the skin fibrosis of systemic sclerosis.

Endothelin-1 (ET-1) acts as a key regulator of vasoconstriction and fibrosis. Many previous studies have focused on the role of ET-1 in scleroderma (systemic sclerosis, SSc). We investigated the effects of ET-1 on the production of extracellular matrix in SSc and normal skin fibroblasts. Primary cultured dermal fibroblasts from SSc patients and healthy controls were treated with ET-1 (25 ng/mL) for 0 min, 15 min, 1 h, 24 h, 48 h and 72 h, respectively. Our results showed that, in SSc fibroblasts, ET-1 upregulated collagen type I, connective tissue growth factor (CTGF), type I plasminogen activator inhibitor (PAI-1) and pAkt in a time-dependent manner within 72 h; in normal fibroblasts, 25 ng/mL ET-1 stimulation correlated with high levels of CTGF, PAI-1 and pAkt. The secretion of fibronectin (FN), collagen type I, and PAI-1 is markedly increased in the supernatant of both SSc fibroblasts and normal fibroblasts. Furthermore, ET-1 phosphorylates Smad2 and Smad3 in normal fibroblasts, but not in SSc fibroblasts. In conclusion, our results demonstrated that ET-1 may induce fibrosis in dermal fibroblasts through Akt signals.

Expression of pigment epithelium-derived factor in human cutaneous appendages.

BACKGROUND: Pigment epithelium-derived factor (PEDF), a 50-kDa glycoprotein and a member of the serine protease inhibitor gene family, is well known as a potent endogenous inhibitor of angiogenesis. However, the expression of PEDF in human cutaneous appendages has not yet been determined. AIM: To investigate the expression of PEDF in human cutaneous appendages. METHODS: Immunohistochemical staining was used to detect the expression of PEDF in human cutaneous appendages. Reverse transcriptase PCR, western blotting and indirect immunofluorescence were used to determine the mRNA and protein expression of PEDF on cells of the outer root sheath (ORS). A wound-healing assay was used to determine the effect of different concentrations of PEDF on the migration of ORS cells. RESULTS: PEDF was expressed in the hair follicle (including epidermal matrix, inner root sheath, ORS and fibrous root sheath), sebaceous glands and eccrine sweat glands. Both protein and RNA expression of PEDF was detected, and expression was localized to both cytoplasm and nucleus of ORS cells. Both interleukin (IL)-4 and IL-17 at 25 ng/mL upregulated the expression of PEDF of ORS cells, with IL-4 having the greater effect. PEDF 50 ng/mL decreased migration of ORS cells. CONCLUSIONS: PEDF is expressed in human cutaneous appendages and may play a modulatory role in the physiology of ORS cells.

Expression and localization of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 in human epidermal appendages: a comparison study by immunofluorescence.

BACKGROUND: Vascular endothelial growth factor (VEGF) promotes angiogenesis and plays important roles in neovascularization and development of tissues. VEGF receptors (VEGFRs) are high-affinity receptors for VEGF and are originally considered specific to endothelial cells. We have previously shown that keratinocytes from human normal skin express VEGFRs. This poses the question of whether these receptors are also expressed by epidermal appendages, as epidermal appendages are lined with epithelial cells. OBJECTIVE: To investigate the expression of VEGFR-2 compare with VEGF in epidermal appendages, including hair follicles, eccrine sweat glands and sebaceous glands. METHODS: Monoclonal antibodies to VEGF and VEGFR-2 were used for immunohistochemical examination of cryostat-cut sections of normal human skin specimens from 11 donors undergoing cosmetic surgery. RESULTS: Immunoreactivities for VEGF and VEGFR-2 principally showed parallel intense expression in anagen hair follicle (including outer root sheat, inner root sheath, dermal papillae epidermal matrix), sebaceous glands (ductal and secretory portions) and eccrine sweat glands (ductal and secretory portions), respectively. In particular, abundant expression of VEGF was found in the follicular basement membrane zone surrounding the bulb matrix and in the ductal and secretory portions of eccrine sweat glands. CONCLUSION: A potential VEGF/VEGFR-2 autocrine pathway may be defined by the coexpression of VEGF and VEGFR-2 in human skin epidermal appendages.

Polymerase chain reaction based C4AQ0 and C4BQ0 genotyping: association with systemic lupus erythematosus in southwest Han Chinese.

OBJECTIVE: To investigate the association of complement C4 null genes (C4Q0, including C4AQ0 and C4BQ0) and C2 gene with systemic lupus erythematosus (SLE) in southwest Han Chinese; 136 patients with SLE and 174 matched controls were genotyped. METHODS: C4 null genes were determined by a polymerase chain reaction (PCR) procedure with sequence specific primers (PCR-SSP). The 2 bp insertion in exon 29, which was previously identified in non-Chinese populations and caused defective C4A genes, was directly typed by sequencing the whole exon 29 using exon specific primers. The exon 6 of complement C2 was also sequenced in both the patients and controls. RESULTS: The frequency of homozygous C4AQ0 allele was 12.5% (17/136) in patients with SLE compared with 1.1% (2/174) in controls (p<0.001, odds ratio (OR)=12.286, 95% confidence interval (95% CI) 2.786 to 54.170). There was no significant difference for homozygous C4BQ0 allele between patients with SLE and controls (p=0.699). Patients with the C4AQ0 gene had an increased risk of acquiring renal disorder, serositis, and anti-dsDNA antibodies compared with those without C4AQ0 (for renal disorder, p=0.018, OR=8.951, 95% CI 1.132 to 70.804; for serositis, p=0.011, OR 4.891, 95% CI 1.574 to 15.198; for anti-dsDNA, p=0.004, OR 7.630, 95%CI 1.636 to 35.584). None of the patients or controls had the 2 bp insertion in exon 29 of the C4 gene. The type I C2 deficiency was not detected in the 310 samples. CONCLUSION: It is suggested that deficiency of C4A (not due to a 2 bp insertion in exon 29), but not C4B or C2, may be a risk factor for acquiring SLE in south west Han Chinese; this results in increased risk of renal disorder, serositis, and anti-dsDNA antibodies in patients with SLE. Racial differences seem to be relevant in susceptibility to SLE