Clinical and genetic characteristics of genetic skeletal disorders

Представлены результаты анализа эффективности использования методов анализа ДНК для диагностики наследственных скелетных дисплазий (НСД) на основе анализа выборки из 270 российских пациентов. Показано, что использование различных молекулярно-генетических методов позволяет уточнить диагноз у 74% больных с клиническими и рентгенологическими признаками системных поражений скелета. Подсчитаны частоты встречаемости восьми групп НСД. Показано, что наиболее часто диагностируются FGFR3-хондродисплазии, коллагенопатии и болезни, обусловленные нарушением сульфатного обмена, на долю которых приходится 67,5% от всех диагностированных НСД. The effectiveness of DNA analysis for diagnostics of genetic skeletal disorders (GSD) based on the investigation of the data of 270 Russian patients was evaluated. The usage of various molecular genetic methods allows to clarify the diagnosis in 74% of patients with clinical and radiological signs of systemic skeletal disorders. The incidence of 8 most common groups of NSD was calculated. It has been shown that the most commonly diagnosed conditions included FGFR3-relared chondrodysplasias, collagenopathies and diseases caused by impaired sulfate metabolism, which account for 67.5% of all diagnosed NSD.

Skeletal Dysplasias Caused by Sulfation Defects

Proteoglycans (PGs) are macromolecules present on the cell surface and in the extracellular matrix that confer specific mechanical, biochemical, and physical properties to tissues. Sulfate groups present on glycosaminoglycans, linear polysaccharide chains attached to PG core proteins, are fundamental for correct PG functions. Indeed, through the negative charge of sulfate groups, PGs interact with extracellular matrix molecules and bind growth factors regulating tissue structure and cell behavior. The maintenance of correct sulfate metabolism is important in tissue development and function, particularly in cartilage where PGs are fundamental and abundant components of the extracellular matrix. In chondrocytes, the main sulfate source is the extracellular space, then sulfate is taken up and activated in the cytosol to the universal sulfate donor to be used in sulfotransferase reactions. Alteration in each step of sulfate metabolism can affect macromolecular sulfation, leading to the onset of diseases that affect mainly cartilage and bone. This review presents a panoramic view of skeletal dysplasias caused by mutations in genes encoding for transporters or enzymes involved in macromolecular sulfation. Future research in this field will contribute to the understanding of the disease pathogenesis, allowing the development of targeted therapies aimed at alleviating, preventing, or modifying the disease progression.

Effects of Thiosulfate as a Sulfur Source on Plant Growth, Metabolites Accumulation and Gene Expression in Arabidopsis and Rice

Plants are considered to absorb sulfur from their roots in the form of sulfate. In bacteria like Escherichia coli, thiosulfate is a preferred sulfur source. It is converted into cysteine (Cys). This transformation consumes less NADPH and ATP than sulfate assimilation into Cys. In Saccharomyces cerevisiae, thiosulfate promoted growth more than sulfate. In the present study, the availability of thiosulfate, the metabolite transformations and gene expressions it induces were investigated in Arabidopsis and rice as model dicots and monocots, respectively. In Arabidopsis, the thiosulfate-amended plants had lower biomass than those receiving sulfate when sulfur concentrations in the hydroponic medium were above 300 μM. In contrast, rice biomass was similar for plants raised on thiosulfate and sulfate at 300 μM sulfur. Therefore, both plants can use thiosulfate but it is a better sulfur source for rice. In both plants, thiosulfate levels significantly increased in roots following thiosulfate application, indicating that the plants absorbed thiosulfate into their root cells. Thiosulfate is metabolized in plants by a different pathway from that used for sulfate metabolism. Thiosulfate increases plant sulfide and cysteine persulfide levels which means that plants are in a more reduced state with thiosulfate than with sulfate. The microarray analysis of Arabidopsis roots revealed that 13 genes encoding Cys-rich proteins were upregulated more with thiosulfate than with sulfate. These results together with those of the widely targeted metabolomics analysis were used to proposes a thiosulfate assimilation pathway in plants.