Enhancing the chondrogenic potential of chondrogenic progenitor cells by deleting RAB5C.

Osteoarthritis (OA) is the most prevalent chronic joint disease that affects a large proportion of the elderly population. Chondrogenic progenitor cells (CPCs) reside in late-stage OA cartilage tissue, producing a fibrocartilaginous extracellular matrix; these cells can be manipulated in vitro to deposit proteins of healthy articular cartilage. CPCs are under the control of SOX9 and RUNX2. In our earlier studies, we showed that a knockdown of RUNX2 enhanced the chondrogenic potential of CPCs. Here we demonstrate that CPCs carrying a knockout of RAB5C, a protein involved in endosomal trafficking, exhibited elevated expression of multiple chondrogenic markers, including the SOX trio, and increased COL2 deposition, whereas no changes in COL1 deposition were observed. We report RAB5C as an attractive target for future therapeutic approaches designed to increase the COL2 content in the diseased joint.

Mapping the secretome of human chondrogenic progenitor cells with mass spectrometry.

Tissue engineering offers promising perspectives in the therapy of osteoarthritis. In the context of cell-based therapy, chondrogenic progenitor cells (CPCs) may be used to regenerate defects in cartilage tissue. An in-depth characterization of the secretome of CPCs is a prerequisite to this approach. In this study, a method was developed for the qualitative and quantitative analysis of the secretome of undifferentiated and differentiated CPCs. Secreted proteins from cells grown in two-dimensional as well as three-dimensional alginate cultures were extracted and analyzed by liquid chromatography/tandem mass spectrometry (LC-MS/MS). Quantitation was achieved by internal standardization using stable isotope-labeled amino acids in cell culture (SILAC). Qualitative analysis of CPC secretomes revealed ECM-components, signal proteins and growth factors most of which were also found in healthy cartilage. A quantitative comparison revealed significantly upregulated proteins with regenerative potential during differentiation, while proteins involved in catabolic metabolism were significantly downregulated. The development of methods for qualitative and quantitative analysis of the secretome of CPCs by mass spectrometry provides a foundation for the investigation of progenitor or stem cells from other sources.

A Streptomyces-specific member of the metallophosphatase superfamily contributes to spore dormancy and interaction with Aspergillus proliferans.

We have identified, cloned and characterized a formerly unknown protein from Streptomyces lividans spores. The deduced protein belongs to a novel member of the metallophosphatase superfamily and contains a phosphatase domain and predicted binding sites for divalent ions. Very close relatives are encoded in the genomic DNA of many different Streptomyces species. As the deduced related homologues diverge from other known phosphatase types, we named the protein MptS (metallophosphatase type from Streptomyces). Comparative physiological and biochemical investigations and analyses by fluorescence microscopy of the progenitor strain, designed mutants carrying either a disruption of the mptS gene or the reintroduced gene as fusion with histidine codons or the egfp gene led to the following results: (i) the mptS gene is transcribed in the course of aerial mycelia formation. (ii) The MptS protein is produced during the late stages of growth, (iii) accumulates within spores, (iv) functions as an active enzyme that releases inorganic phosphate from an artificial model substrate, (v) is required for spore dormancy and (vi) MptS supports the interaction amongst Streptomyces lividans spores with conidia of the fungus Aspergillus proliferans. We discuss the possible role(s) of MptS-dependent enzymatic activity and the implications for spore biology.

[Evaluation of traumatic findings in decomposed bodies in Aydin]. / Aydin'da bozulmus cesetlerdeki travmatik bulgularin degerlendirilmesi.

BACKGROUND: In this study, we discuss traumatic lesions as assessed in decomposed bodies. METHODS: From 1390 autopsies, which were performed by Adnan Menderes University, Faculty of Medicine, Department of Forensic Medicine staff during the period 2004-2008, reports of 62 decomposed bodies were searched, and traumatic lesions were found in 19 of them. Features like gender, living conditions, crime scene, identity witness, season, postmortem interval, cause and origin of deaths, and existence of traumatic lesions were investigated. RESULTS: From the 1390 forensic autopsies, 4.5% were decomposed bodies. Male cases accounted for 91.9%, and the male/female ratio was 11.4/1. From reports, 38.7% lived alone, and the crime scene was the home in 57.9%. Traumatic lesions were found in 30.6%. The leading causes of death were cardiac diseases in natural deaths, hanging in suicide cases, stab wounds in homicide cases, and carbon monoxide poisoning in accidents. It was statistically significant that traumatic lesions were common in outdoor cases and indoor bodies were common among single cases. CONCLUSION: As it is necessary to distinguish traumatic lesions carefully in decomposed bodies, a full examination and autopsy should be performed.