Introduction. The vascular calcification, recruiting osteo-progenitors under inflammatory stimulation, recapitulates the normal bone-biogenesis process. We recently identified a population of Mesenchymal Stem Cells (MSCs) within abdominal aortic aneurysm (AAA) tissues, hypothesizing their contribution to the atherosclerotic plaque calcification. Aim. The present study aimed at exploring the impact of inflammation, a feature of atherosclerosis, on osteogenic differentiation of vascular MSCs. Methods. The extent of calcification within AAA tissues was detected by Alizarin Red stain. MSCs were enzymatically isolated from human healthy cryopreserved thoracic aortas (hMSCs) and from AAA (AAA-MSCs) biopsies. hMSCs and AAA-MSCs were characterized by flow cytometry and compared in terms of osteogenic potential. In order to investigate the effect of the inflammatory milieu on plaque calcification, hMSCs were primed with a cytokine cocktail (TNF-a/IL-1b) for 24 h before osteogenic induction. The osteogenic differentiation was induced by a specific growth media for 21 days, followed by Alizarin Red stain of calcium deposits and osteogenic factors analysis. Results. Alizarin Red confirmed the presence of large calcified areas within the AAA wall. Healthy- and AAA-MSCs both expressed the typical MSC markers CD90, CD73, CD105 and CD44. AAA-MSCs had an higher degree of mineralization activity in comparison to the healthy MSC population, confirmed by the up-regulation of the osteogenic factors BMP-2 and OPN transcriptional levels (1.5 and 15 folds increase when compared to hMSCs, respectively). The inflammatory priming induced the expression of osteogenic factors BMP-2 and OPN genes and proteins in hMSCs. Accordingly, hMSCs pre-cultured under inflammatory conditions also had increased mineralization activity. Conclusion. Vascular MSCs actively regulates the atherosclerosis progression, becoming a crucial source of osteoprogenitors. This process is sharpened by the local inflammatory milieu, supporting a tight association among inflammation, osteogenic differentiation and plaque calcification.
Vascular MSCs govern the atherosclerotic plaque calcification under inflammatory conditions
Ciavarella C;Sonetto A;Gallitto E;Faggioli GL;Gargiulo M;Pasquinelli G
2019
Abstract
Introduction. The vascular calcification, recruiting osteo-progenitors under inflammatory stimulation, recapitulates the normal bone-biogenesis process. We recently identified a population of Mesenchymal Stem Cells (MSCs) within abdominal aortic aneurysm (AAA) tissues, hypothesizing their contribution to the atherosclerotic plaque calcification. Aim. The present study aimed at exploring the impact of inflammation, a feature of atherosclerosis, on osteogenic differentiation of vascular MSCs. Methods. The extent of calcification within AAA tissues was detected by Alizarin Red stain. MSCs were enzymatically isolated from human healthy cryopreserved thoracic aortas (hMSCs) and from AAA (AAA-MSCs) biopsies. hMSCs and AAA-MSCs were characterized by flow cytometry and compared in terms of osteogenic potential. In order to investigate the effect of the inflammatory milieu on plaque calcification, hMSCs were primed with a cytokine cocktail (TNF-a/IL-1b) for 24 h before osteogenic induction. The osteogenic differentiation was induced by a specific growth media for 21 days, followed by Alizarin Red stain of calcium deposits and osteogenic factors analysis. Results. Alizarin Red confirmed the presence of large calcified areas within the AAA wall. Healthy- and AAA-MSCs both expressed the typical MSC markers CD90, CD73, CD105 and CD44. AAA-MSCs had an higher degree of mineralization activity in comparison to the healthy MSC population, confirmed by the up-regulation of the osteogenic factors BMP-2 and OPN transcriptional levels (1.5 and 15 folds increase when compared to hMSCs, respectively). The inflammatory priming induced the expression of osteogenic factors BMP-2 and OPN genes and proteins in hMSCs. Accordingly, hMSCs pre-cultured under inflammatory conditions also had increased mineralization activity. Conclusion. Vascular MSCs actively regulates the atherosclerosis progression, becoming a crucial source of osteoprogenitors. This process is sharpened by the local inflammatory milieu, supporting a tight association among inflammation, osteogenic differentiation and plaque calcification.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
