Articular cartilage vesicles contain RNA
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Authors: Mitton, Elizabeth; Gohr, Claudia M.; McNally, Mark T.; Rosenthal, Ann K.
Abstract
Small membrane-bound extracellular organelles known as articular cartilage matrix vesicles (ACVs) participate in pathologic mineralization in osteoarthritic articular cartilage. ACVs are also present in normal cartilage, although they have no known functions other than mineralization. Recently, RNA was identified in extracellular vesicles derived from mast cells, suggesting that such vesicles might carry coding information from cell to cell. We found that ACVs from normal porcine and human articular cartilage and primary chondrocyte conditioned media contained 1 mu g RNA/80 mu g ACV protein. No DNA could be detected. RT-PCR of ACV RNA demonstrated the presence of full length mRNAs for factor XIIIA, type II transglutaminase, collagen II, aggrecan, ANKH and GAPDH. RNA in intact ACVs was resistant to RNase, despite the fact that ACV preparations contained measurable levels of active RNases. Significantly, radiolabeled RNA in ACVs could be transferred to unlabeled chondrocytes by co-incubation and produced changes in levels of chondrocyte enzymes and proteins. The demonstration that ACVs contain mRNAs suggests that they may function to shuttle genetic information between articular cells and indicate novel functions for these structures in articular cartilage. (C) 2009 Elsevier Inc. All rights reserved.
Familial calcium pyrophosphate dihydrate deposition disease. A Tunisian kindred
JOINT BONE SPINE
Authors: Bejia, I; Rtibi, I; Touzi, M; Zrour, S; Younes, M; Naceur, B
Abstract
Introduction. - Familial calcium pyrophosphate dihydrate deposition disease (CPDD) is uncommon, with about 50 affected families identified to date in the world. Genetic studies in familial CPDD are focusing on the ANKH gene. We report a new Tunisian kindred with CPDD. Patients and methods. - The development of CPDD in a patient who was only 35 years of age prompted a family study. A medical history, physical examination, and radiographs were performed in 103 family members older than 18 years. Results. - Fifteen family members had CPDD. There were 10 men and five women, with a mean age of 59.4 years. Onset was usually in the third or fourth decade. Four clinical patterns were found: Five patients had pseudogout, five had pseudoosteoarthritis, three had asymptomatic disease, and two had pseudorheumatoid arthritis. Inheritance was autosomal dominant with low penetrance. No associations with specific HLA antigens were found. The disease was mild. These characteristics fit the description of Gaucher type 1 familial CPDD. Conclusion. - Inherited autosomal dominant CPDD with low penetrance was found in 15 members of a Tunisian kindred. The disease was mild. We are planning a genetic study including tests for ANKH gene mutations in this kindred. (C) 2003 Elsevier SAS. All rights reserved.