Genetic and epigenetic insights into systemic lupus erythematosus: linking long non-coding RNA growth arrest-specific transcript 5 and interferon signature.

OBJECTIVE

Interferon (IFN) signaling, and excessive apoptosis have a well-established role in systemic lupus erythematosus (SLE) pathogenesis. Long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) has been linked to excessive apoptosis and upregulation of IFN genes. We aimed to investigate the expression of IFN-stimulated genes in SLE patients compared to healthy controls, and to assess their association with lncRNA GAS5 and clinical characteristics of SLE.

METHODS

The study included 30 SLE patients and 20 controls. IFN-stimulatory genes (interferon-induced protein 44-like [IFI44L] gene, MX dynamin like GTPase 1 [MX1], IFN-induced protein with tetratricopeptide repeats 1 [IFIT1]) and GAS5 expression levels in plasma were estimated by quantitative real-time polymerase chain reaction. IFN signature score was calculated.

RESULTS

IFIT1 gene expression and IFN signature score were significantly higher in SLE patients compared to controls (p<0.001, p<0.001, respectively). LncRNA GAS5 positively correlated with IFIT1 expression (p<0.001) and IFN signature score (p=0.005). No significant associations were found between IFN gene expression or IFN signature score and disease activity (Systemic Lupus Erythematosus Disease Activity Index 2000, SLEDAI-2K) or organ damage (Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index, SDI). IFI44L expression was significantly higher in SLE patients with secondary antiphospholipid syndrome (p=0.040).

CONCLUSION

IFN signature is a potential biomarker for SLE diagnosis, but it can't be relied on for the assessment of activity or damage. The correlation between lncRNA GAS5 and IFN-related gene expression suggests a possible role for GAS5 in the IFN pathway in SLE.