Resistin Gene Expression is Downregulated in CD4(+) T Helper Lymphocytes and CD14(+) Monocytes in Rheumatoid...

Area of Science:

• Immunology
• Molecular Biology
• Rheumatology

Background:

• Rheumatoid arthritis (RA) pathogenesis involves complex immune cell interactions and Th1 cytokines.
• Resistin (RETN), an inflammatory cytokine primarily secreted by human monocytes, has uncertain roles in immune responses, potentially being pro-inflammatory, pro-fibrotic, or tolerogenic.

Purpose of the Study:

• To investigate the impact of tumor necrosis factor-alpha inhibition (TNF-αI) on resistin (RETN) gene expression in key immune cell subsets within the context of RA.
• To analyze changes in Th1, inflammatory, and regulatory cytokine gene expression alongside RETN expression following TNF-αI.

Main Methods:

• Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to measure gene expression levels.
• Immune cell subsets, including CD14(+) monocytes, CD4(+) T helper lymphocytes, CD8(+) T cytotoxic lymphocytes, and CD19(+) B lymphocytes, were isolated using antibody-coated beads.
• Gene expression of RETN, IFN-γ, TNF-β, IL-1β, TNF-α, TGF-β, and IL-10 was assessed in active RA patients before and 3 months after initiating TNF-αI.

Main Results:

• TNF-αI significantly downregulated RETN gene expression in CD14(+) monocytes and CD4(+) T helper lymphocytes.
• RETN gene expression remained unchanged in CD8(+) T cytotoxic lymphocytes and CD19(+) B lymphocytes after TNF-αI.
• Monocytes consistently exhibited higher RETN mRNA levels compared to other cell types, both in active RA and during TNF-αI.
• A significant correlation was observed between the fold changes in RETN and TGF-β gene expression in monocytes following TNF-αI.

Conclusions:

• Resistin (RETN) gene expression in monocytes and T helper cells is sensitive to TNF-α inhibition in rheumatoid arthritis.
• The findings suggest that RETN plays a dual role in active RA, exhibiting both pro-inflammatory and pro-resolving properties.
• Further research into RETN's complex functions in RA pathogenesis is warranted.