Abnormal PTPN11 enhancer methylation promotes rheumatoid arthritis fibroblast-like synoviocyte aggressiveness and joint inflammation
Keisuke Maeshima, … , Nunzio Bottini, Gary S. Firestein
Keisuke Maeshima, … , Nunzio Bottini, Gary S. Firestein
Published May 19, 2016
Citation Information: JCI Insight. 2016;1(7):e86580. https://doi.org/10.1172/jci.insight.86580.
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Research Article Inflammation

Abnormal PTPN11 enhancer methylation promotes rheumatoid arthritis fibroblast-like synoviocyte aggressiveness and joint inflammation

Abstract

The PTPN11 gene, encoding the tyrosine phosphatase SHP-2, is overexpressed in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) compared with osteoarthritis (OA) FLS and promotes RA FLS invasiveness. Here, we explored the molecular basis for PTPN11 overexpression in RA FLS and the role of SHP-2 in RA pathogenesis. Using computational methods, we identified a putative enhancer in PTPN11 intron 1, which contained a glucocorticoid receptor–binding (GR-binding) motif. This region displayed enhancer function in RA FLS and contained 2 hypermethylation sites in RA compared with OA FLS. RA FLS stimulation with the glucocorticoid dexamethasone induced GR binding to the enhancer and PTPN11 expression. Glucocorticoid responsiveness of PTPN11 was significantly higher in RA FLS than OA FLS and required the differentially methylated CpGs for full enhancer function. SHP-2 expression was enriched in the RA synovial lining, and heterozygous Ptpn11 deletion in radioresistant or innate immune cells attenuated K/BxN serum transfer arthritis in mice. Treatment with SHP-2 inhibitor 11a-1 reduced RA FLS migration and responsiveness to TNF and IL-1β stimulation and reduced arthritis severity in mice. Our findings demonstrate how abnormal epigenetic regulation of a pathogenic gene determines FLS behavior and demonstrate that targeting SHP-2 or the SHP-2 pathway could be a therapeutic strategy for RA.

Authors

Keisuke Maeshima, Stephanie M. Stanford, Deepa Hammaker, Cristiano Sacchetti, Li-fan Zeng, Rizi Ai, Vida Zhang, David L. Boyle, German R. Aleman Muench, Gen-Sheng Feng, John W. Whitaker, Zhong-Yin Zhang, Wei Wang, Nunzio Bottini, Gary S. Firestein

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Figure 6

In vivo inhibition of SHP-2 attenuates arthritis in mice.

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In vivo inhibition of SHP-2 attenuates arthritis in mice. (A) At 6 to 10...
(A) At 6 to 10 weeks of age, female Ptpn11fl/+-Mx1 cre– (n = 3) and cre+ (n = 4) mice were injected i.p. with 3 doses of 300 μg polyinosinic-polycytidylic acid [poly(I:C)] every other day. Ten days after the last poly(I:C) treatment, mice were injected i.p. with 200 μl K/BxN sera to induce arthritis. Ankle thickness was measured every other day after serum transfer. Mean ± SEM ankle swelling is shown. *P < 0.05, 1-tailed unpaired t test. (B–D) Female C57BL/6 mice were administered 200 μl K/BxN sera at 8 weeks of age and administered 7.5 mg/kg 11a-1 (n = 5) or vehicle (n = 4) i.p. daily for 14 days. (B) Mean ± SEM ankle swelling is shown. Data were analyzed using 2-way ANOVA. (C and D) Histological analyses of ankles stained with H&E or Safranin-O at the end of the disease course. (C) Scatter plots show the mean ± SEM histological score of each ankle. Data were analyzed using the 2-tailed Mann-Whitney test. (D) Representative images of H&E-stained (yellow arrows indicate regions of inflammatory infiltrate) or Safranin-O–stained (red arrows indicate regions of cartilage erosion) joints are shown. Scale bars: 200 μm.