Tacrolimus reverses pemphigus vulgaris serum-induced depletion of desmoglein in HaCaT cells via inhibition of heat shock protein 27 phosphorylation.

BACKGROUND: Glucocorticoids are the first-line treatment for Pemphigus vulgaris (PV), but its serious side effects can be life-threatening for PV patients. Tacrolimus (FK506) has been reported to have an adjuvant treatment effect against PV. However, the mechanism underlying the inhibitory effect of FK506 on PV-IgG-induced acantholysis is unclear. OBJECTIVE: The objective of this study was to explore the effect of FK506 on desmoglein (Dsg) expression and cell adhesion in an immortalized human keratinocyte cell line (HaCaT cells) stimulated with PV sera. METHODS: A cell culture model of PV was established by stimulating HaCaT cells with 5% PV sera with or without FK506 and clobetasol propionate (CP) treatment. The effects of PV sera on intercellular junctions and protein levels of p38 mitogen-activated protein kinase (p38MAPK), heat shock protein 27 (HSP27), and Dsg were assayed using western blot analysis, immunofluorescence staining, and a keratinocyte dissociation assay. RESULTS: PV sera-induced downregulation of Dsg3 was observed in HaCaT cells and was blocked by FK506 and/or CP. Immunofluorescence staining revealed that linear deposits of Dsg3 on the surface of HaCaT cells in the PV sera group disappeared and were replaced by granular and agglomerated fluorescent particles on the cell surface; however, this effect was reversed by FK506 and/or CP treatment. Furthermore, cell dissociation assays showed that FK506 alone or in combination with CP increased cell adhesion in HaCaT cells and ameliorated loss of cell adhesion induced by PV sera. Additionally, FK506 noticeably decreased the PV serum-induced phosphorylation of HSP 27, but had no effect on p38MAPK phosphorylation. CONCLUSION: FK506 reverses PV-IgG induced-Dsg depletion and desmosomal dissociation in HaCaT cells, and this effect may be obtained by inhibiting HSP27 phosphorylation.

The effect of l-carnitine supplementation on serum levels of omentin-1, visfatin and SFRP5 and glycemic indices in patients with pemphigus vulgaris: A randomized, double-blind, placebo-controlled clinical trial.

Pemphigus vulgaris (PV) is a chronic autoimmune disorder with potentially fatal outcomes. The aim of this study was to investigate the effect of l-carnitine (LC) on secreted frizzled-related protein-5 (SFRP5), omentin, visfatin, and glycemic indices in PV patients under corticosteroid treatment. In this randomized, double-blind, placebo-controlled clinical trial, 52 patients with PV were divided randomly into two groups to receive 2 g of LC or a placebo for 8 weeks. Serum levels of SFRP5, omentin, visfatin, and also glycemic indices were evaluated at the baseline and end of the study. LC supplementation significantly decreased the serum level of visfatin (95% CI [-14.718, -0.877], p = .05) and increased the serum levels of SFRP5 (95%CI [1.637, 11.380], p < .006) and omentin (95% CI [9.014, 65.286], p < .01). However, LC supplementation had no significant effects on the serum levels of glycemic factors such as insulin (95% CI [-1.125, 3.056], p = .426), fasting blood sugar (95% CI [-4.743, 3.642], p = .894), homeostatic model assessment of insulin resistance (95% CI [-0.305, 0.528], p = .729), and quantitative insulin-sensitivity check index (95% CI [-0.016, -0.010], p = .81). LC supplementation decreased visfatin serum level and increased omentin-1 and SFRP5 serum levels in patients with PV. However, it has no significant effect on the serum levels of insulin and glycemic indices.

The IgG "lupus-band" deposition pattern of pemphigus erythematosus: association with the desmoglein 1 ectodomain as revealed by 3 cases.

BACKGROUND: Pemphigus foliaceus is an autoimmune skin disease characterized by subcorneal blistering and IgG antibodies directed against desmoglein 1. In the skin, these antibodies deposit intraepidermally. On rare occasions,an additional "lupus band" of granular depositions of IgG and complement is seen along the epidermal basement membrane zone. This combined pattern has been connected with a variant of pemphigus foliaceus named pemphigus erythematosus. OBSERVATIONS: We describe 3 pemphigus foliaceus cases in which phototherapy was administered after a misdiagnosis of psoriasis. This treatment resulted in a flare of skin lesions. Direct immunofluorescence of skin biopsy specimens that were obtained several weeks later demonstrated intraepidermal and granular basement membrane zone depositions. The basement membrane zone depositions consisted of IgG, complement, and the ectodomain of desmoglein 1 and were located below the lamina densa. CONCLUSIONS: High doses of UV light are likely to induce the cleaving of the desmoglein 1 ectodomain. In patients with pemphigus foliaceus, the circulating anti­desmoglein 1 antibodies precipitate this cleaved-off ectodomain along the basement membrane zone, resulting in a lupus band­like appearance. In pemphigus erythematosus, a similar mechanism may be active, which might explain the lupus-band phenomenon.

Human VAT-1: a calcium-regulated activation marker of human epithelial cells.

BACKGROUND AND AIMS: Human VAT-1 (hVAT-1) is a homologue of the synaptic vesicle membrane protein of Torpedo californica. Its coding gene is located near the BRCA1 locus and thus hVAT-1 may be linked to an inherited predisposition to breast and ovary cancer. However, the hVAT-1 protein expression pattern in normal epithelial tissues such as skin, mammary gland and ovary, as well as in tumours of the mammary gland and ovary, has not been studied. METHODS: To address this issue, an immunohistological analysis of biopsies of normal epidermis and lesional epidermis of bullous pemphigoid and pemphigus vulgaris patients was undertaken. RESULTS: hVAT-1-expression was observed in basal keratinocytes of lesional epidermis of bullous pemphigoid patients but not in normal epidermis or in lesional epidermis of pemphigus vulgaris patients. Moreover, hVAT-1 expression in HaCaT cells was found to be calcium-dependent. Normal and malignant mammary and ovary epithelium were found to be hVAT-1-negative. CONCLUSIONS: Our results indicate that hVAT-1 exerts a specific function in keratinocyte physiology, in particular in calcium-regulated processes, with no evident deregulation in malignancies of the breast and ovary.