ORIGINAL ARTICLES MCP-1 and CCR2 Gene Variants and the Risk for Osteoporosis and Osteopenia Hakan Eraltan, 1 Canan Cacina, 2 Ozlem Timirci Kahraman, 2 Ozlem Kurt, 3 Hulya Yilmaz Aydogan, 2 Mehmet Uyar, 4 Ays xe Can, 3 and Bedia Cakmakog ˘lu 2 Aim: In this study, we investigated whether monocyte chemotactic protein 1 ( MCP-1) and CC chemokine receptor 2 (CCR2) gene polymorphisms account for an increased risk of osteoporosis or osteopenia. Methods: Three hundred three postmenopausal women, 80 osteoporotic, 123 osteopenic, and 100 unrelated age-matched healthy controls, were included in the study. Genotyping of MCP-1 A2518G and CCR2 V64I gene polymor- phisms were detected by PCR-RFLP. Results: We, for the first time, demonstrated the positive association of MCP-1 GG, CCR2 Val/Ile, and CCR2 Val + genotype with osteoporosis risk. However, CCR2 Ile/Ile genotype frequencies were high in the control group compared with those of the patients with osteoporosis and osteo- penia. Haplotype analysis confirmed the association of MCP-1/CCR2 gene variants with osteopenia and re- vealed that the frequency of MCP-1 A:CCR2 Val haplotype was significantly higher in patients when compared with controls. Conclusions: In conclusion, our findings have suggested that MCP-1 and CCR2 gene variants were risk factors for osteoporosis and osteopenia. Introduction O steoporosis is a systemic skeletal disease in which loss of bone mass and the microarchitectural deterioration of bone tissue leads to fragility fractures (Zajickova and Zofkova, 2003; Raisz, 2005). Enhanced bone resorption may be related with osteoclastogenesis from precursor cells, enhanced fusion and activation of osteoclasts, and prolonged lifespan due to an inhibition of osteoclast apoptosis (Manolagas, 2000; Tei- telbaum, 2000). There are multiple mechanisms that play roles in the regulation of bone remodeling, and these involve not only the osteoblastic and osteoclastic cell lineages but also other marrow cells, in addition to the interaction of systemic hormones, local cytokines, growth factors, and transcription factors (Raisz, 2005). They are speculated as candidates for involvement in bone loss in different types of inflammatory diseases through the recruitment of osteoclast precursors but their potential effects in osteoclast recruitment, development, or function are not well understood (Choi et al., 2000; Yu et al., 2004). Osteoblasts have also been shown as a source of che- mokines in bones (Yu et al., 2004). Chemokines, particularly of two major (CXC, CC) families, are essential signals for the trafficking and localization of circulating hematopoietic cells. Monocyte chemotactic protein 1 (MCP-1, CCL2 or SCYA2) is the most investigated CCL chemokine family member (Van Coillie et al., 1999). It is expressed by various types of cells which include fibroblasts, endothelial cells (Yu and Graves, 1995), and osteoblasts (Simonet et al., 1997) and exhibits che- moattractant activity toward osteoclasts. It has been reported that an A2518G polymorphism in the regulatory region of the MCP-1 gene affects MCP-1 expression in response to inflam- matory stimuli (Rovin et al., 1999). The cellular influence of MCP-1 is mediated by the CC chemokine receptor 2 (CCR2), a G-coupled receptor (Rollins, 1997). A 190 G/A single- nucleotide polymorphism (SNP) in the CCR2 gene, located on chromosome 3p21-p24, is the most researched CCR2 SNP in exon 1 (Murphy et al., 2000).This mutation results in the sub- stitution of valine by isoleucine (V64I) in the transmembrane region of the protein (Attar et al., 2010). In light of this infor- mation, our aim in this study was to investigate some possible associations between MCP-1 A2518G and CCR2 V64I gene polymorphisms and the risk for osteoporosis. Subjects and Methods Subjects The cohort of this study contained 303 Turkish postmeno- pausal women (80 osteoporotic, 123 osteopenic, and 100 healthy), 40–78 years of age, attending the Uskudar State Hospital in Istanbul between June 2009 and March 2010. 1 Department of Physical Medicine and Rehabilitation, Azerbaijan Medical University, Baku, Azerbaijan. 2 Department of Molecular Medicine, Institute of Experimental Medicine Research, Istanbul University, Istanbul, Turkey. 3 Department of Biochemistry, Faculty of Pharmacy, Istanbul University, Istanbul, Turkey. 4 Department of Physical Medicine and Rehabilitation, Uskudar State Hospital, Istanbul, Turkey. GENETIC TESTING AND MOLECULAR BIOMARKERS Volume 16, Number 4, 2012 ª Mary Ann Liebert, Inc. Pp. 229–233 DOI: 10.1089/gtmb.2011.0216 229