Gene Expression Profile in Osteoblastic Cells Stimulated with Hyaluronan

Objectives: Hyaluronan (HA), which is a ubiquitous component of various tissues, is thought to facilitate cell migration, proliferation, and tissue repair. We hypothesized that the application of HA to the site of injury can provide a potential therapy for bone repair. We previously demonstrated that osteoblasts in the presence of HA (1 mg/ml) proliferated significantly in vitro. But gene expression patterns of the osteoblast treated with HA are unclear. In this study we analyzed the molecular events that occur in osteoblastic cells cultured with HA using a microarray. Methods: Osteoblastic MC3T3-E1 cells were grown in culture medium with or without 1 mg/ml of HA (molecular weight: 6-12x10⁵) for 7 days. Total RNA was extracted, reverse transcribed and double stranded cDNA synthesized. cDNAs were labeled with either fluorescent Cy3-UTP or Cy5-UTP, and hybridized on the DNA array. The hybridized arrays were visualized using an array scanner. Results: Of the 15,432 reliable genes detected, 889 were differentially expressed by MC3T3-E1 cells in the presence of HA. Among the 889, 192 were found to be up-regulated, whereas 697 genes demonstrated down-regulation. Conclusion: Our data provides a comprehensive picture of gene activity related to HA and will facilitate future investigation of the roles of HA in osteoblasts. Supported by a Grant-in-Aid for Young Scientists (B) from the Ministry of Education, Culture, Sports, Science and Technology (No.16791221) and Osaka Dental University Joint Research Funds (B03-01).