Decorin and biglycan expression: its relation with endothelial heterogeneity
Graciela C. Calabrese1, Silvina Gazzaniga2, Roxana Oberkersch1 and Rosa Wainstok2
1Biological Science Department, Faculty of Pharmacy and Biochemistry, Buenos Aires University, Ciudad Autónoma de Buenos Aires, Argentina and 2Biological Chemistry Department, Faculty of Science, Buenos Aires University, Ciudad Universitaria, Pabellón II, Ciudad Autónoma de Buenos Aires, Argentina.
Offprint requests to: Graciela C. Calabrese, Cátedra de Biología Celular y Molecular, Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954 (C1113AAD), Ciudad Autónoma de Buenos Aires, Argentina. e-mail: email@example.com
Summary. Decorin and biglycan proteoglycans play important roles in the organization of the extracellular matrix, and in the regulation of cell adhesion and migration. Given morphological and functional endothelial heterogeneity, information is needed regarding whether endothelial cells (ECs) from different vascular beds possess different profiles of proteoglycan constituents of the basement membranes.
Here, we report that endothelia from different murine organs and EC lines derived thereof produce and secrete different patterns of proteoglycans. A faint colocalization between decorin and PECAM/CD31 was found on tissue sections from mouse heart, lung and kidney by immunofluorescence. Three EC lines derived from these organs produced decorin (100-kDa) and its core protein (45-kDa). Extracellular decorin recognition in culture supernatant was only possible after chondroitin lyase digestion suggesting that the core protein of secreted proteoglycan is more encrypted by glycosaminoglycans than the intracellular one. Heart and lung ECs were able to produce and release decorin. Kidney ECs synthesized the proteoglycan and its core protein but no secretion was detected in culture supernatants. Although biglycan production was recorded in all EC lines, secretion was almost undetectable, consistent with immunofluorescence results. In addition, no biglycan secretion was detected after EC growth supplement treatment, indicating that biglycan is synthesized, secreted and quickly degraded extracellularly by metalloproteinase-2. Low molecular-mass dermatan sulfate was the predominant glycosaminoglycan identified bound to the core protein. ECs from different vascular beds, with differences in morphology, physiology and cell biology show differences in the proteoglycan profile, extending their heterogeneity to potential differences in cell migration capacities. Histol Histopathol 26, 481-490 (2011)
Key words: Endothelial cells, Decorin, Biglycan, Glycosaminoglycans, Extracellular matrix