Defective proteoglycan sulfation of the growth plate zones causes reduced chondrocyte proliferation via an altered Indian hedgehog signalling.

Mutations in the sulfate transporter gene, SCL26A2, lead to cartilage proteoglycan undersulfation resulting in chondrodysplasia in humans; the phenotype is mirrored in the diastrophic dysplasia (dtd) mouse. It remains unclear whether bone shortening and deformities are caused solely by changes in the cartilage matrix, or whether chondroitin sulfate proteoglycan undersulfation affects also signalling pathways involved in cell proliferation and differentiation. Therefore we studied macromolecular sulfation in the different zones of the dtd mouse growth plate and these data were related to growth plate histomorphometry and proliferation analysis.

In utero transplantation of adult bone marrow decreases perinatal lethality and rescues the bone phenotype in the knockin murine model for classical, dominant osteogenesis imperfecta.

Autosomal dominant osteogenesis imperfecta (OI) caused by glycine substitutions in type I collagen is a paradigmatic disorder for stem cell therapy. Bone marrow transplantation in OI children has produced a low engraftment rate, but surprisingly encouraging symptomatic improvements. In utero transplantation (IUT) may hold even more promise.

A quantitative and qualitative method for direct 2-DE analysis of murine cartilage.

Direct 2-DE analysis of cartilage is difficult due to the high proteoglycan content. Proteoglycan removal before IEF may however cause the partial or total loss of specific proteins making this approach ineffective when quantitative data are required to investigate protein expression differences. Thus, we have developed a 2-DE method including passive rehydration loading that does not require sample pretreatment and allows direct protein expression studies in cartilage samples.

Differential expression of both extracellular and intracellular proteins is involved in the lethal or nonlethal phenotypic variation of BrtlIV, a murine model for osteogenesis imperfecta.

This study used proteomic and transcriptomic techniques to understand the molecular basis of the phenotypic variability in the bone disorder osteogenesis imperfecta (OI). Calvarial bone mRNA expression was evaluated by microarray, real-time, and comparative RT-PCR and the bone proteome profile was analyzed by 2-DE, MS, and immunoblotting in the OI murine model BrtlIV, which has either a moderate or a lethal OI outcome. Differential expression analysis showed significant changes for eight proteins.

Human recombinant prolidase from eukaryotic and prokaryotic sources. Expression, purification, characterization and long-term stability studies.

Prolidase is a Mn(2+)-dependent dipeptidase that cleaves imidodipeptides containing C-terminal proline or hydroxyproline. In humans, a lack of prolidase activity causes prolidase deficiency, a rare autosomal recessive disease, characterized by a wide range of clinical outcomes, including severe skin lesions, mental retardation, and infections of the respiratory tract. In this study, recombinant prolidase was produced as a fusion protein with an N-terminal histidine tag in eukaryotic and prokaryotic hosts and purified in a single step using immobilized metal affinity chromatography.

In vivo contribution of amino acid sulfur to cartilage proteoglycan sulfation.

Cytoplasmic sulfate for sulfation reactions may be derived either from extracellular fluids or from catabolism of sulfur-containing amino acids and other thiols. In vitro studies have pointed out the potential relevance of sulfur-containing amino acids as sources for sulfation when extracellular sulfate concentration is low or when its transport is impaired such as in DTDST [DTD (diastrophic dysplasia) sulfate transporter] chondrodysplasias. In the present study, we have considered the contribution of cysteine and cysteine derivatives to in vivo macromolecular sulfation of cartilage by using the mouse model of DTD we have recently generated [Forlino, Piazza, Tiveron, Della Torre, Tatangelo, Bonafe, Gualeni, Romano, Pecora, Superti-Furga et al.

The role of emerging techniques in the investigation of prolidase deficiency: from diagnosis to the development of a possible therapeutical approach.

The aim of the present article is to review the efforts performed in the past two decades by numerous research groups for the development of methods that allow a correct diagnosis of prolidase deficiency (PD), a rare autosomal recessive disorder and for the rationalization of a possible therapeutic intervention on these patients. In particular, the interest of the reader is focused on the application of capillary electrophoresis (i) for the detection of biological markers that reflect the pathological feature of the disease and (ii) for the determination of the efficiency of a carrier system in delivering prolidase inside cells in a possible therapy based on enzyme replacement.

N-benzyloxycarbonyl-L-proline: an in vitro and in vivo inhibitor of prolidase.

Prolidase deficiency (PD) is a recessive disorder of the connective tissue caused by mutations in the prolidase, a specific peptidase, cleaving the dipeptides with a C-terminal prolyl and hydroxyprolyl residue. PD is a complex syndrome characterized mainly by intractable skin lesions, recurrent respiratory infections and mental retardation. The relation between prolidase biological functions and the disease is still largely unknown.

A diastrophic dysplasia sulfate transporter (SLC26A2) mutant mouse: morphological and biochemical characterization of the resulting chondrodysplasia phenotype.

Mutations in the diastrophic dysplasia sulfate transporter (DTDST or SLC26A2) cause a family of recessively inherited chondrodysplasias including, in order of decreasing severity, achondrogenesis 1B, atelosteogenesis 2, diastrophic dysplasia (DTD) and recessive multiple epiphyseal dysplasia. The gene encodes a widely distributed sulfate/chloride antiporter of the cell membrane whose function is crucial for the uptake of inorganic sulfate, which is needed for proteoglycan sulfation. To provide new insights in the pathogenetic mechanisms leading to skeletal and connective tissue dysplasia and to obtain an in vivo model for therapeutic approaches to DTD, we generated a Dtdst knock-in mouse with a partial loss of function of the sulfate transporter.

Beta2-microglobulin isoforms display an heterogeneous affinity for type I collagen.

It has been claimed that beta2-microglobulin (beta2-m) interacts with type I and type II collagen, and this property has been linked to the tissue specificity of the beta2-m amyloid deposits that target the osteo-articular system. The binding parameters of the interaction between collagen and beta2-m were determined by band shift electrophoresis and surface plasma resonance by using bovine collagen of type I and type II and various isoforms of beta2-m. Wild-type beta2-m binds collagen type I with a Kd of 4.

Micellar electrokinetic chromatographic and capillary zone electrophoretic methods for screening urinary biomarkers of human disorders: a critical review of the state-of-the-art.

Human urine plays a central role in clinical diagnostic being one of the most-frequently used body fluid for detection of biological markers. Samples from patients with different diseases display patterns of biomarkers that differ significantly from those obtained from healthy subjects. The availability of fast, reproducible, and easy-to-apply analytical techniques that would allow identification of a large number of these analytes is thus highly desiderable since they may provide detailed information about the progression of a pathological process.

Intracellular delivery of liposome-encapsulated prolidase in cultured fibroblasts from prolidase-deficient patients.

Prolidase is a cytosolic exopeptidase whose deficiency causes the development of a rare autosomal recessive disorder known as Prolidase Deficiency (PD). The main manifestations of PD are intractable ulcerations of the skin, recurrent infections and mental retardation. At this time only a hazardous and expensive chronic therapy based on blood transfusions is the suggested treatment for PD.

Characterization of a new PEPD allele causing prolidase deficiency in two unrelated patients: natural-occurrent mutations as a tool to investigate structure-function relationship.

Prolidase deficiency (PD) is a rare autosomal recessive disorder characterized mainly by skin lesions of the legs and feet, mental retardation, and respiratory infections. Mutations at the PEPD locus, located on chromosome 19, are responsible for this disease. We identified a new PEPD allele in two unrelated Portuguese PD patients by analyses of reverse transcribed PCR-amplified cDNA.

High-performance liquid chromatography and capillary electrophoresis: methodological challenges for the determination of biologically relevant low-aliphatic aldehydes in human saliva.

Tobacco smoke is involved in the pathogenesis of cardiovascular and respiratory diseases and also has a local toxic effect in the oral cavity. Low-aliphatic aldehydes, such as formaldehyde, acetaldehyde and acrolein, are among the main components of mainstream cigarette smoke and their local noxious and carcinogenic effects in the oral cavity and upper gastrointestinal tract are well-known. Although various studies have been performed so far to determine their content in cigarette smoke, none has included the direct measurement of these compounds in the saliva of smoking and nonsmoking subjects.

Capillary electrophoresis with laser-induced fluorescence detection as a novel sensitive approach for the analysis of desmosines in real samples.

Among various biomarkers believed to behave as descriptors of the disease process in chronic obstructive pulmonary disease (COPD), urinary desmosines are commonly used for monitoring elastin degradation. Given the low concentrations of urinary desmosines, their quantitative determination in this biological matrix often requires preconcentration steps. To minimize both solute losses and effects of sample matrix, and to decrease data variability related to the above-mentioned manipulation processes, we have developed a capillary electrophoresis approach combined with laser-induced fluorescence (CE-LIF) detection system using urine samples not submitted to any pretreatment procedure other than filtering the sample.

In vitro proteoglycan sulfation derived from sulfhydryl compounds in sulfate transporter chondrodysplasias.

Mutations in a sulfate-chloride antiporter gene, the diastrophic dysplasia sulfate transporter (DTDST), have been associated with a family of skeletal dysplasias including recessive multiple epiphyseal dysplasia, diastrophic dysplasia (DTD), atelosteogenesis type 2, and achondrogenesis type 1B (ACG1B). DTDST function is crucial for uptake of extracellular sulfate required for proteoglycan (PG) sulfation; the tissue-specific expression of the clinical phenotype may be the consequence of the high rate of PG synthesis in chondrocytes and the ensuing high sulfate requirement. We have studied the contribution of cysteine and its derivatives to PG sulfation in fibroblast and chondrocyte cultures from sulfate transporter dysplasia patients.

Optimization of a capillary electrophoretic method to detect and quantify the Gly-Pro dipeptide in complex matrices from long term cultured prolidase deficiency fibroblasts.

A capillary electrophoresis (CE) method has been developed and optimized for the detection of Gly-Pro dipeptide in complex biological samples: medium, cell layer and matrix obtained from long term cultured human fibroblasts of control and prolidase deficiency patients. The influence of different detergents in the sample preparation and electrophoretic conditions were investigated. The method was validated for cellular extracts with respect to limits of detection and quantitation, precision, linearity, accuracy and robustness.

Mutation analysis of five new patients affected by prolidase deficiency: the lack of enzyme activity causes necrosis-like cell death in cultured fibroblasts.

Prolidase, a ubiquitously distributed dipeptidase, is involved in the latter stage of degradation of endogenous and dietary proteins and is particularly important in collagen catabolism. It hydrolyzes dipeptides containing proline or hydroxyproline at the C-terminal position. Mutations in the gene encoding for prolidase cause prolidase deficiency (PD), an autosomal recessive disorder mainly characterized by skin lesions, mental retardation and recurrent infectious.