Rituximab Downregulates Gene Expression Associated with Cell Proliferation, Survival, and Proteolysis in the Peripheral Blood from Rheumatoid Arthritis Patients: A Link between High Baseline Autophagy-Related ULK1 Expression and Improved Pain Control.

Sergey A Makarov,Aleksandr N Kuzin,Anastasya N Pivanova,Elena V Tchetina,Andrey P Aleksankin,Galina A Markova,Galina V Lukina,Elena N Aleksandrova

doi:10.1155/2016/4963950

Sergey A Makarov, Aleksandr N Kuzin + Show 6 more

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https://doi.org/10.1155/2016/4963950

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Abstract

Objective. To clarify molecular mechanisms for the response to rituximab in a longitudinal study. Methods. Peripheral blood from 16 RA patients treated with rituximab for a single treatment course and 26 healthy controls, blood and knee articular cartilages from 18 patients with long-standing RA, and cartilages from 14 healthy subjects were examined. Clinical response was assessed using ESR, ACPA, CRP, RF, DAS28 levels, CD19+ B-cell counts, bone erosion, and joint space narrowing scores. Protein expression in PBMCs was quantified using ELISA. Gene expression was performed with quantitative real-time PCR. Results. A decrease (p < 0.05) in DAS28, ESR, and CRP values after rituximab treatment was associated with the downregulation of MTOR, p21, caspase 3, ULK1, TNFα, IL-1β, and cathepsin K gene expression in the peripheral blood to levels found in healthy subjects. MMP-9 expression remained significantly higher compared to controls although decreased (p < 0.05) versus baseline. A negative correlation between baseline ULK1 gene expression and the number of tender joints at the end of follow-up was observed. Conclusions. The response to rituximab was associated with decreased MTOR, p21, caspase 3, ULK1, TNFα, IL-1β, and cathepsin K gene expression compared to healthy subjects. Residual increased expression in MMP-9, IFNα, and COX2 might account for remaining inflammation and pain. High baseline ULK1 gene expression indicates a good response in respect to pain.

Highlights

Rheumatoid arthritis (RA) is one of the most common autoimmune rheumatic diseases and represents a complex systemic multifactorial inflammatory process involving joint destruction [1, 2]
We found that a significant decrease in DAS28, ESR, and CRP values after RTX therapy was associated with downregulation of MTOR, caspase 3, Unc-51-like kinase 1 (ULK1), TNFα, IL-1β, and cathepsin K gene expression to levels found in healthy subjects
The majority of the examined genes, including the regulator of cell growth and proliferation MTOR; the autophagy marker ULK1; the apoptosis indicator caspase-3; the proinflammatory cytokines TNFα, IL-1β, IFNα, and COX2; and the proteases MMP-9 and cathepsin K, were significantly upregulated in a sample of RA patients (n = 16) at baseline compared to healthy subjects (Figure 1)

Summary

Objective

To clarify molecular mechanisms for the response to rituximab in a longitudinal study. A decrease (p < 0.05) in DAS28, ESR, and CRP values after rituximab treatment was associated with the downregulation of MTOR, p21, caspase 3, ULK1, TNFα, IL-1β, and cathepsin K gene expression in the peripheral blood to levels found in healthy subjects. MMP-9 expression remained significantly higher compared to controls decreased (p < 0.05) versus baseline. A negative correlation between baseline ULK1 gene expression and the number of tender joints at the end of follow-up was observed. The response to rituximab was associated with decreased MTOR, p21, caspase 3, ULK1, TNFα, IL-1β, and cathepsin K gene expression compared to healthy subjects. Residual increased expression in MMP-9, IFNα, and COX2 might account for remaining inflammation and pain. High baseline ULK1 gene expression indicates a good response in respect to pain

Introduction

Patients and Methods

Results

Discussion