Abstract
Objectives:
Recent studies indicate that glucose metabolism is altered in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS). Hexokinases (HK) is catalyze the first step in glucose metabolism and HK2 constitutes the principal HK inducible isoform. We hypothesize that HK2 contributes to the synovial lining hypertrophy and plays a critical role in bone and cartilage damage.
Methods:
HK1 and HK2 expression were determined in RA and osteoarthritis (OA) synovial tissue by immunohistochemistry. RA FLS were transfected with either HK1 or HK2 siRNA, or infected with either adenovirus (ad)-GFP, ad-HK1 or ad-HK2. FLS migration and invasion were assessed. To study the role of HK2 in vivo, 108 particles of ad-HK2 or ad-GFP were injected into the knee of WT mice. K/BxN serum-transfer arthritis was induced in HK2F/F mice harboring Col1a1-Cre (HK2Col1), to delete HK2 in non-hematopoietic cells.
Results:
HK2 is particular of RA histopathology (9/9 RA; 1/8 OA) and co-localizes with FLS markers. Silencing HK2 in RA FLS resulted in a less invasive and migratory phenotype. Consistently, overexpression of HK2 resulted in an increased ability to migrate and invade. It also increased extracellular lactate production. Intra-articular injection of ad-HK2 in normal knees dramatically increased synovial lining thickness, FLS activation and proliferation. HK2 was highly expressed in the synovial lining after K/BxN serum transfer arthritis. HK2Col1 mice significantly showed decreased arthritis severity, bone and cartilage damage.
Conclusion:
HK2 is specifically expressed in RA synovial lining and regulates FLS aggressive functions. HK2 might be an attractive selective metabolic target safer than global glycolysis for RA treatment.
Recent studies indicate that glucose metabolism is altered in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS). Hexokinases (HK) is catalyze the first step in glucose metabolism and HK2 constitutes the principal HK inducible isoform. We hypothesize that HK2 contributes to the synovial lining hypertrophy and plays a critical role in bone and cartilage damage.
Methods:
HK1 and HK2 expression were determined in RA and osteoarthritis (OA) synovial tissue by immunohistochemistry. RA FLS were transfected with either HK1 or HK2 siRNA, or infected with either adenovirus (ad)-GFP, ad-HK1 or ad-HK2. FLS migration and invasion were assessed. To study the role of HK2 in vivo, 108 particles of ad-HK2 or ad-GFP were injected into the knee of WT mice. K/BxN serum-transfer arthritis was induced in HK2F/F mice harboring Col1a1-Cre (HK2Col1), to delete HK2 in non-hematopoietic cells.
Results:
HK2 is particular of RA histopathology (9/9 RA; 1/8 OA) and co-localizes with FLS markers. Silencing HK2 in RA FLS resulted in a less invasive and migratory phenotype. Consistently, overexpression of HK2 resulted in an increased ability to migrate and invade. It also increased extracellular lactate production. Intra-articular injection of ad-HK2 in normal knees dramatically increased synovial lining thickness, FLS activation and proliferation. HK2 was highly expressed in the synovial lining after K/BxN serum transfer arthritis. HK2Col1 mice significantly showed decreased arthritis severity, bone and cartilage damage.
Conclusion:
HK2 is specifically expressed in RA synovial lining and regulates FLS aggressive functions. HK2 might be an attractive selective metabolic target safer than global glycolysis for RA treatment.
| Original language | English |
|---|---|
| Journal | Annals of the Rheumatic Diseases |
| Early online date | 30 Jul 2018 |
| DOIs | |
| Publication status | E-pub ahead of print - 30 Jul 2018 |
Keywords
- rheumatoid arthritis
- fibroblast-like synoviocyte
- glucose metabolism
- hexokinase