Identification of Chondrocyte Genes and Signaling Pathways in Response to Acute Joint Inflammation
Abstract
Traumatic joint injuries often result in elevated proinflammatory cytokine (such as IL-1β) levels in the joint cavity, which can increase the catabolic activities of chondrocytes and damage cartilage. This study investigated the early genetic responses of healthy in situ chondrocytes under IL-1β attack with a focus on cell cycle and calcium signaling pathways. RNA sequencing analysis identified 2,232 significantly changed genes by IL-1β, with 1,259 upregulated and 973 downregulated genes. Catabolic genes related to ECM degeneration were promoted by IL-1β, consistent with our observations of matrix protein loss and mechanical property decrease during 24-day in vitro culture of cartilage explants. IL-1β altered the cell cycle (108 genes) and Rho GTPases signaling (72 genes) in chondrocytes, while chondrocyte phenotypic shift was observed with histology, cell volume measurement, and MTT assay. IL-1β inhibited the spontaneous calcium signaling in chondrocytes, a fundamental signaling event in chondrocyte metabolic activities. The expression of 24 genes from 6 calcium-signaling related pathways were changed by IL-1β exposure. This study provided a comprehensive list of differentially expressed genes of healthy in situ chondrocytes in response to IL-1β attack, which represents a useful reference to verify and guide future cartilage studies related to the acute inflammation after joint trauma.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 14, 2019
- Source ID
- 10.1038/s41598-018-36500-2
Entities
People
- Leo Q. Wan
- Lin Han
- Liyun Wang
- Meiqing Wang
- Mengxi Lv
- Shawn W Polson
- X. Lucas Lu
- Yilu Zhou
Organizations
- Foundation for the National Institutes of Health
- Osteo Science Foundation
- United States Department of Defense