Melanocytes--a novel tool to study mitochondrial dysfunction in Duchenne muscular dystrophy.

Dystrophin is a subsarcolemmal protein that, by linking the actin cytoskeleton to the extracellular matrix via dystroglycans, is critical for the integrity of muscle fibers. Here, we report that epidermal melanocytes, obtained from conventional skin biopsy, express dystrophin with a restricted localization to the plasma membrane facing the dermal-epidermal junction. In addition the full-length muscle isoform mDp427 was clearly detectable in melanocyte cultures as assessed by immunohistochemistry, RNA, and Western blot analysis.

Antisense-induced messenger depletion corrects a COL6A2 dominant mutation in Ullrich myopathy.

Collagen VI gene mutations cause Ullrich and Bethlem muscular dystrophies. Pathogenic mutations frequently have a dominant negative effect, with defects in collagen VI chain secretion and assembly. It is agreed that, conversely, collagen VI haploinsufficiency has no pathological consequences.

Effects of a hydroxyapatite-based biomaterial on gene expression in osteoblast-like cells.

Biostite is a hydroxyapatite-derived biomaterial that is used in periodontal and bone reconstructive procedures due to its osteoconductive properties. Since the molecular effects of this biomaterial on osteoblasts are still unknown, we decided to assess whether it may specifically modulate osteoblast functions in vitro. We found that a brief exposure to Biostite significantly reduced the proliferation of MG-63 and SaOS-2 osteoblast-like cells to approximately 50% of the plateau value.

Nonspecific cation current associated with native polycystin-2 in HEK-293 cells.

Mutations in either PKD1 or PKD2 gene are associated with autosomal dominant polycystic kidney disease, the most common inherited kidney disorder. Polycystin-2 (PC2), the PKD2 gene product, and the related protein polycystin-L, function as Ca(2+)-permeable, nonselective cation channels in different expression systems. This work describes a nonspecific cation current (I(CC)) that is present in native HEK-293 cells and highly associated with a PC2-channel activity.

The cytoplasmic C-terminus of polycystin-1 increases cell proliferation in kidney epithelial cells through serum-activated and Ca(2+)-dependent pathway(s).

Polycystin-1 (PC1) is a large transmembrane protein important in renal differentiation and defective in most cases of autosomal dominant polycystic kidney disease (ADPKD), a common cause of renal failure in adults. Although the genetic basis of ADPKD has been elucidated, molecular and cellular mechanisms responsible for the dysregulation of epithelial cell growth in ADPKD cysts are still not well defined. We approached this issue by investigating the role of the carboxyl cytoplasmic domain of PC1 involved in signal transduction on the control of kidney cell proliferation.

Deficiency of polycystin-2 reduces Ca2+ channel activity and cell proliferation in ADPKD lymphoblastoid cells.

Polycystin-2 (PC2), encoded by the PKD2 gene, mutated in 10-15% of autosomal-dominant polycystic kidney disease (ADPKD) patients, is a Ca2+-permeable cation channel present in kidney epithelia and other tissues. As PC2 was found expressed in B-lymphoblastoid cells (LCLs) and Ca2+ signaling pathways are important regulators of B cell function activities, we investigated whether PC2 plays some role in B-LCLs. In LCLs, PC2 was found mainly in ER membranes but ~8 times less than in kidney HEK293 cells.

Expression of polycystin-1 C-terminal fragment enhances the ATP-induced Ca2+ release in human kidney cells.

Polycystin-1 (PC1) is a membrane protein expressed in tubular epithelia of developing kidneys and in other ductal structures. Recent studies indicate this protein to be putatively important in regulating intracellular Ca(2+) levels in various cell types, but little evidence exists for kidney epithelial cells. Here we examined the role of the PC1 cytoplasmic tail on the activity of store operated Ca(2+) channels in human kidney epithelial HEK-293 cell line.

Preferential expression of the transcription coactivator HTIF1alpha gene in acute myeloid leukemia and MDS-related AML.

HTIF1alpha, a transcription coactivator which is able to mediate RARalpha activity and functionally interact with PML, is encoded by a gene on chromosome 7q32-34, which is a critical region in acute myeloid leukemias (AML). With the assumption that this gene may be related to AML, we investigated the HTIF1alpha DNA structure and RNA expression in leukemic cells from 36 M1-M5 AML patients (28 "de novo" and eight "secondary" to myelodysplastic syndrome (MDS)). Abnormal HTIF1alpha DNA fragments were never found, whereas loss of HTIF1alpha DNA was observed in the patients with chromosome 7q32 deletion and translocation, and in one case without detectable chromosome 7 abnormality.

MECP2 gene mutation analysis in the British and Italian Rett Syndrome patients: hot spot map of the most recurrent mutations and bioinformatic analysis of a new MECP2 conserved region.

Rett syndrome (RTT) is an X-linked dominant neurological disorder, which appears to be the most common genetic cause of profound combined intellectual and physical disability in Caucasian females. This syndrome has been associated with mutations of the MECP2 gene, a transcriptional repressor of unknown target genes. We report a detailed mutational analysis of a large cohort of RTT patients from the UK and Italy.

Mutation analysis of the MECP2 gene in British and Italian Rett syndrome females.

Rett syndrome is an X-linked dominant neurological disorder, which appears to be the commonest genetic cause of profound combined intellectual and physical disability in Caucasian females. Recently, this syndrome has been associated with mutations of the MECP2 gene, a transcriptional repressor of still unknown target genes. Here we report a detailed mutational analysis of 62 patients from UK and Italian archives, representing the first comparative study among different populations and one of the largest number of cases so far analyzed.

Mutation and transcription analysis of transthyretin gene in Italian families with hereditary amyloidosis: a putative novel hot spot' in codon 47.

Transthyretin gene mutations are associated with autosomal dominant familial amyloidosis. The commonest phenotype in the patients is peripheral neuropathy, but restrictive cardiomyopathy is also a frequent sign. More than 70 different mutations in the gene have been described.

Mutations in autosomal dominant polycystic kidney disease 2 gene: Reduced expression of PKD2 protein in lymphoblastoid cells.

The polycystic kidney disease 2 (PKD2) gene, encoding a 968-amino acid integral membrane protein with six predicted membrane-spanning domains and intracellular NH2 and COOH termini, is mutated in approximately 15% of the cases of autosomal dominant polycystic kidney disease (ADPKD), a common genetic disease frequently resulting in renal failure. For a better understanding of the cause of this disorder, we searched for mutations in the PKD2 gene in two PKD2-linked families characterized by different clinical phenotypes. A common polymorphism, a nonsense mutation, and a frameshift mutation were found.

K562 erythroid and HL60 macrophage differentiation downregulates polycystin, a large membrane-associated protein.

Polycystin, the PKD1 gene product mutated in autosomal dominant polycystic kidney disease, is a large membrane protein which is important in the differentiation of epithelial tubular structure. Furthermore, PKD1 mRNA is expressed in various tissues and in neoplastic cell lines particularly, suggesting that polycystin might be involved in differentiation and/or proliferation of other cell types. Therefore, in order to investigate such a possible role, polyclonal antibodies against a recombinant polycystin peptide were raised and used to study polycystin expression in human leukemia cell lines committed to differentiation.