Hailey-Hailey disease and tight junctions: Claudins 1 and 4 are regulated by ATP2C1 gene encoding Ca(2+) /Mn(2+) ATPase SPCA1 in cultured keratinocytes

Mutations in the ATP2C1 gene encoding Ca(2+) /Mn(2+) ATPase SPCA1 cause Hailey-Hailey disease (HHD, OMIM 16960). HHD is characterized by epidermal acantholysis. We attempted to model HHD using normal keratinocytes, in which the SPCA1 mRNA was down-regulated with the small inhibitory RNA (siRNA) method. SiRNA inhibition significantly down-regulated the SPCA1 mRNA, as demonstrated by qPCR, and decreased the SPCA1 protein beyond detectable level, as shown by Western analysis. The expression of selected desmosomal, adherens and tight junction (TJ) proteins was then studied in the SPCA1-deficient and control keratinocytes cultured in low (0.06 mm) or high (1.2 mm) calcium concentration. The mRNA and protein levels of most TJ components were up-regulated in non-treated control keratinocyte cultures upon switch from low to high calcium concentration. In contrast, SPCA1-deficient keratinocytes displayed high levels of TJ proteins claudins 1 and 4 even in low calcium. ZO-1 did not, however, follow similar expression patterns. Protein levels of occludin, beta-catenin, E-cadherin, desmoplakin, desmogleins 1-3, desmocollin 2/desmocollin 3 and plakoglobin did not show marked changes in SPCA1-deficient keratinocytes. Indirect immunofluorescence labelling revealed delayed translocation of desmoplakin and desmoglein 3 in desmosomes and increased intracellular pools of TJ and desmosomal components in SPCA1-inhibited keratinocytes. The results show that SPCA1 regulates the levels of claudins 1 and 4, but does not affect desmosomal protein levels, indicating that TJ proteins are differently regulated. The results also suggest a potential role for claudins in HHD.

Topical tacrolimus in Hailey-Hailey disease

Hailey-Hailey disease, or familial benign chronic pemphigus, is a rare relapsing-remitting autosomal-dominant epidermal blistering disease. It preferentially affects females and is characterized by recurrent vesicles and erosions in the intertriginous areas. There are several topical corticosteroid therapeutic options, which are often limited in their use by their secondary effects and localization of the lesions. We report a case of a 60-year-old woman with Hailey-Hailey disease involving axillary, groin, cervical, antecubital, inframammary and abdominal folds. She was treated with 0.1% tacrolimus ointment, applied twice daily, with clinical improvement in 2 weeks and total remission in 4 weeks. She remains asymptomatic after a 10-month follow-up period.

Functional expression of heterologous proteins in yeast: insights into Ca2+signaling and Ca2+-transporting ATPases

The baker's yeast Saccharomyces cerevisiae is a well-developed, versatile, and widely used model organism. It offers a compact and fully sequenced genome, tractable genetics, simple and inexpensive culturing conditions, and, importantly, a conservation of basic cellular machinery and signal transducing pathways with higher eukaryotes. In this review, we describe recent technical advances in the heterologous expression of proteins in yeast and illustrate their application to the study of the Ca2+homeostasis machinery, with particular emphasis on Ca2+-transporting ATPases. Putative Ca2+-ATPases in the newly sequenced genomes of organisms such as parasites, plants, and vertebrates have been investigated by functional complementation of an engineered yeast strain lacking endogenous Ca2+pumps. High-throughput screens of mutant phenotypes to identify side chains critical for ion transport and selectivity have facilitated structure-function analysis, and genomewide approaches may be used to dissect cellular pathways involved in Ca2+transport and trafficking. The utility of the yeast system is demonstrated by rapid advances in the study of the emerging family of Golgi/secretory pathway Ca2+,Mn2+-ATPases (SPCA). Functional expression of human SPCA1 in yeast has provided insight into the physiology, novel biochemical characteristics, and subcellular localization of this pump. Haploinsufficiency of SPCA1 leads to Hailey-Hailey disease (HDD), a debilitating blistering disorder of the skin. Missense mutations, identified in patients with HHD, may be conveniently assessed in yeast for loss-of-function phenotypes associated with the disease.

[Localized Castleman disease with paraneoplastic pemphigus and pulmonary involvement: clinical features and histopathology]

OBJECTIVE

To investigate the clinical, histopathologic and CT features of localized Castleman disease complicated with paraneoplastic pemphigus (PNP) and pulmonary involvement.

METHODS

The clinical, laboratory, histopathologic records and data of computed tomographic (CT) images of 4 patients of Castleman disease with PNP were reviewed.

RESULTS

All of the four patients presented with PNP which was confirmed by pathological and immunological studies and also developed lung abnormalities, including bronchiolitis obliterans (n = 3), lung abscess (n = 1) and multiple lung infarction (n = 1), 2 to 5 months after the onset of PNP. Castleman's tumor, which was found incidentally during routine examination, manifested as a solitary and huge mass (5 to 14 cm in size) which markedly enhanced homogeneously on CT in the retroperitoneum (n = 3) and mediastinum (n = 1). Histologically, three cases were of hyaline-vascular type and the other one was of mixed type. Complete remission of PNP occurred 2 weeks to 8 months after surgical resection of the tumor. The condition of two patients with bronchiolitis obliterans failed to be improved. They had been presenting dyspnea and irritable cough 3 to 15 months after surgery.

CONCLUSION

PNP and lung abnormalities are rare and severe complications of localized Castleman's disease. Early diagnosis and surgery are very important for prognosis.

Hailey-Hailey disease: molecular and clinical characterization of novel mutations in the ATP2C1 gene

Hailey-Hailey disease is an autosomal dominant skin disorder characterized by suprabasal cell separation (acantholysis) of the epidermis. Mutations in ATP2C1, the gene encoding a novel, P-type Ca2+-transport ATPase, were recently found to cause Hailey-Hailey disease. In this study, we used conformation-sensitive gel electrophoresis to screen all 28 translated exons of ATP2C1 in 24 Hailey-Hailey disease families and three sporadic cases with the disorder. We identified 22 different mutations, 18 of which have not previously been reported, in 25 probands. The novel mutations comprise three nonsense, six insertion/deletion, three splice-site, and six missense mutations and are distributed throughout the ATP2C1 gene. Six mutations were found in multiple families investigated here or in our previous study. Haplotype analysis revealed that two of these are recurrent mutations that have not been inherited from a common ancestor. Comparison between genotype and phenotype in 23 families failed to yield any clear correlation between the nature of the mutation and clinical features of Hailey-Hailey disease. The extensive interfamilial and intrafamilial phenotypic variability observed suggests that modifying genes and/or environmental factors may greatly influence the clinical features of this disease.

Immunolocalization of human gelatinase (type IV collagenase, MMP-9) and tissue inhibitor of metalloproteinase 1 in Hailey-Hailey and Darier's diseases

BACKGROUND

The formation of lacunae and acantholysis as well as dyskeratosis are characteristic features of Hailey-Hailey disease (HHD) and Darier's disease (DD). Matrix metalloproteinases (MMPs) and their inhibitors like tissue inhibitors of metalloproteinases (TIMPs) have been thought to play major roles in the tissue metabolism.

OBJECTIVE

The aim of this study was to investigate the role of MMP-9 and TIMP-1 in HHD and DD.

METHODS

We examined localizations of these two molecules by immunostaining using specific monoclonal antibodies.

RESULTS

MMP-9 was positively stained in dyskeratotic or detaching cells around lacunae in HHD and DD. TIMP-1 showed a positive staining pattern throughout the epidermis.

CONCLUSION

MMP-9 might be involved in the pathophysiological process of HHD and DD in the presence of TIMP-1.