TABLE 3.

Major overlapping miRNAs in systemic sclerosis (SSc) and idiopathic pulmonary fibrosis (IPF)

	SSc				IPF
	Fibroblasts		Serum expression	Skin expression	Fibroblasts		Serum expression	Lung expression
	Expression	Effect			Expression	Effect
29a-3p	↓	Mimic induces apoptosis, abrogates collagen expression, increases collagen degradation	↑ in RNP+ compared to ACA+	↓				↓
29b-3p	↓	Mimic abrogates collagen expression	↑	↓				↓
29c-3p	↓	Mimic abrogates ECM expression		↓	↓	Overexpression abrogates collagen expression		↓
21-5p	↔		↑ in RNP+ compared to ACA+		↑	Knockdown abrogates collagen expression and EMT	↑ in rapid progressive disease - associated with worse FVC	↑
92a-3p	↔	Overexpression induces collagen degradation	↔ in SSc and in SSc-ILD	↔				↔
26a-5p			↓	↔		Overexpression abrogates collagen expression and EMT		↓
let-7d-5p	↓		↓	↓		Overexpression reduces EMT	↓ in slowly and rapid progressive disease	↓

The table compares the expression levels and the effects of major overlapping miRNAs in SSc skin and fibroblasts with those observed in IPF lung and fibroblasts. Circulating serum levels for SSc and IPF patients are also reported. RNP+: SSc patients with anti-U1 ribonucleoprotein antibodies; ACA+: SSc patients with anticentromere antibodies; ECM: extracellular matrix; EMT: epithelial–mesenchymal transition; FVC: forced vital capacity; SSc-ILD: systemic sclerosis-associated interstitial lung disease. ↑: high levels; ↓: low levels; ↔: controversial results.