Table 1.

Epigenetic alterations and potential epigenetic biomarkers identified in SLE.

Mechanism	Target	Cell Type	Alteration	Consequence
DNA methylation	ITGAL (CD11a)	CD4 T cells	Hypomethylation	Increased CD11a expression
	CD70 (TNFSF7)	CD4 T cells	Hypomethylation	Increased CD70 expression and B-cell costimulation
	CD154 (CD40L)	CD4 T cells	Hypomethylation	Increased B-cell costimulation
	Perforin	CD4 T cells	Hypomethylation	Increased perforin expression
	KIR family	CD4 T cells	Hypomethylation	Increased KIR expression
	RUNX3	CD4 T cells	Hypermethylation	Dysregulation of ITGAL (CD11a) expression
	MMP9	CD4 T cells	Hypomethylation	Cellular basement membrane breakdown
	CD9	CD4 T cells	Hypomethylation	T-cell activation
Histone modification	Histone H4	Monocytes	Increased acetylation	Increased expression of proinflammatory cytokines
MicroRNA	miR-146a	PBMCs	Underexpression	Type I IFN overproduction
	miR-21	CD4 T cells	Overexpression	Downregulation of DNMT1 (indirect) and thus decreased DNA methylation
	miR-148a	CD4 T cells	Overexpression	Downregulation of DNMT1 (direct) and decreased DNA methylation
	miR-125a	PBMCs	Underexpresssion	Increased KLF expression and thus RANTES overproduction
	miR-126	CD4 T cells	overexpression	Downregulation of DNMT1 and decreased DNA methylation

IFN, interferon; KIR, killer immunoglobulin-like receptor; KLF, Kruppel-like factor; MMP, matrix metalloproteinase PBMC, peripheral blood mononuclear cell; RANTES, regulated on activation normal T cell expression and secreted; RUNX, runt-related transcription factor; SLE, systemic lupus erythematosus