Journal of Cellular Biochemistry 101:1430–1438 (2007) Simvastatin and Atorvastatin Enhance Gene Expression of Collagen Type 1 and Osteocalcin in Primary Human Osteoblasts and MG-63 Cultures Silvia Ruiz-Gaspa, 1 Xavier Nogues, 1,2,4 * Anna Enjuanes, 1 Joan C. Monllau, 1,2 Josep Blanch, 1 Ramon Carreras, 2 Leonardo Mellibovsky, 1,4 Daniel Grinberg, 3 Susana Balcells, 3 Adolfo Dı ´ez-Perez, 1,2,4 and Juan Pedro-Botet 2,4 1 URFOA, IMIM, Hospital del Mar, Barcelona, Spain 2 Universitat Auto ` noma de Barcelona, Barcelona, Spain 3 Department of Genetics, Universitat de Barcelona, Barcelona, Spain 4 Department of Medicine, Hospital del Mar, Barcelona, Spain Abstract To clarify the mechanism of the stimulatory effect of statins on bone formation, we have assessed the effect of simvastatin and atorvastatin on osteoblast activity by analysing cell proliferation, as well as collagen, osteocalcin, and bone morphogenetic protein-2 (BMP2) gene expression in primary human osteoblast (hOB) and MG-63 cell line cultures. Explants of bone from patients without any metabolic disease under orthopedic hip procedures were used to obtain hOB. Cell cultures were established, synchronized, and different concentrations of simvastatin or atorvastatin were added (10 9 M, 10 8 M, 10 7 M, 10 6 M) during the experiment. Cell proliferation was analyzed after 24 h. Collagen polypeptide a1 type 1 (COL1A1) gene expression, osteocalcin, and BMP2 expression levels were quantified by real-time PCR after 24 h incubation with statins. There was a statistically significant decrease in cell proliferation related to simvastatin or atorvastatin addition at all concentrations in primary hOB compared with those not treated. A significant increase in COL1A1, osteocalcin, and BMP2 gene expression was detected when hOB cultures were treated with simvastatin or atorvastatin at different concentrations. Similar but less significant effects were found on MG-63 cells. After statin treatment we observed both an arrest of proliferation in hOB cells and an increase in collagen, osteocalcin, and BMP2 gene expression, consistent with a stimulatory effect towards mature osteoblast differentiation. These findings support the bone-forming effect of statins, probably through the BMP2 pathway. J. Cell. Biochem. 101: 1430 – 1438, 2007. ß 2007 Wiley-Liss, Inc. Key words: cholesterol-lowering drugs; human osteoblast; collagen; calcium Osteoporosis and atherosclerosis are widely prevalent conditions and induce serious effects on health, mainly in postmenopausal women and in the aging population. There is growing evidence that osteoporosis and atherosclerosis are linked by biological associations [Hofbauer and Schoppet, 2004; Hamerman, 2005] Although osteoporosis results from an imbal- ance between the bone-forming action of osteo- blasts and the bone resorptive action of osteoclasts, resulting in an increased risk of fractures [NIH Consensus, 2001], the majority of currently available treatments, such as estrogens, bisphosphonates, and raloxifene, act through a decrease in osteoclastic bone resorption rather than enhancing bone forma- tion [Hodgson et al., 2003]. However, a sub- stantial number of fractures are still observed in patients on these medications, and in instances where advanced bone loss has already occurred. Therefore, these patients could greatly benefit from bone anabolic agents in order to restore ß 2007 Wiley-Liss, Inc. Grant sponsor: The Spanish Ministerio de Sanidad; Grant number: (FIS 01/1333); Grant sponsor: Spanish Athero- sclerosis Society; Grant sponsor: Catalan Departament de Universitats, Recerca i Societat de la Informacio ´; Grant number: (2005SGR 00762). *Correspondence to: Xavier Nogues, MD, PhD, URFOA, IMIM.UAB, Servei de Medicina Interna, Hospital del Mar, Passeig Maritim 5-29, E-08003 Barcelona, Spain. E-mail: xnogues@imas.imim.es Received 20 June 2006; Accepted 7 December 2006 DOI 10.1002/jcb.21259