Original Research ARTICLE
Galectins-1 and -3 Increase in Equine Post-traumatic Osteoarthritis
- 1Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, United States
- 2Department of Bioengineering, College of Engineering, University of Washington, United States
- 3Sidney Kimmel Medical College (SKMC), United States
- 4Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, United States
- 5Department of Large Animal Clinical Sciences, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University College Station, United States
Galectins are potent regulators of cell adhesion, growth and apoptosis in diverse cell types, including chondrocytes and synovial fibroblasts. Elevations in synovial fluid galectin-3 have been observed in rheumatoid arthritis, juvenile idiopathic arthritis and experimental inflammatory arthritis in animal models, whereas galectin-1 is thought to be protective. Less is known about galectins-1 and -3 in osteoarthritis (OA). Therefore, the purpose of this study was: (1) to determine whether galectin -1 and -3 synovial fluid concentrations and synovial membrane and cartilage histochemical staining were altered following osteochondral injury in an experimental equine osteoarthritis (OA) model and (2) to measure galectin-1 and -3 mRNA expression and synovial fluid concentrations in naturally occurring equine carpal OA. Synovial fluid galectin-1 and -3 concentrations were quantified using custom ELISAs in two research horse cohorts undergoing experimental OA induction (n = 5 and 4) and in a cohort of horses with naturally occurring carpal OA (n = 57). Galectin mRNA expression in synovial membrane and cartilage tissue obtained from carpal joints of horses with naturally occurring OA was measured using RT-qPCR, and galectin immunostaining was assessed in synovial membrane and osteochondral tissues in the experimental model (n = 5). Synovial fluid galectin-1 and -3 concentrations increased following experimental carpal osteochondral fragmentation. Cartilage galectin-1 mRNA expression increased with OA severity in naturally occurring disease. The superficial zone of healthy articular cartilage stained intensely for galectin-3 in sham-operated joints, whereas galectin-1 staining was nearly absent. Chondrocyte galectin-1 and -3 immunoreactivity increased following cartilage injury, particularly in galectin-1 positive chondrones. Galectins-1 and -3 are present in healthy equine synovial fluid and increase following post-traumatic OA. Healthy superficial zone chondrocytes express galectin-3, whereas galectin-1 chondrocyte staining is limited predominantly to chondrones and injured cartilage. Further work is needed to clarify the functions of galectins-1 and -3 in healthy and OA joints.
Keywords: Inflammatory arthritis, Cartilage, Synovium & Osteoarthritis, chondrocyte, synoviocyte, Horse (Equus caballus), Rheumatod arthritis
Received: 14 Aug 2018;
Accepted: 30 Oct 2018.
Edited by:Troy N. Trumble, University of Minnesota Twin Cities, United States
Reviewed by:Dilip K. Garikipati, Cleveland Clinic, United States
Emma N. Adam, University of Kentucky, United States
Copyright: © 2018 Reesink, Nixon, Su, Liu, Sutton, Mann, Watts and Peterson. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Heidi L. Reesink, Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, 14853, New York, United States, email@example.com