Psoriasis, non-alcoholic fatty liver disease, and cardiovascular disease: Three different diseases on a unique background

Table 1 Role of inflammatory biomarkers in psoriasis, non-alcoholic fatty liver disease and cardiovascular diseases

	Psoriasis	CVD	NAFLD
TNF-alpha	↑Keratinocyte proliferation ↑Pro-inflammatory cytokine production ↑Expression of vascular endothelial cell adhesion molecules ↑Angiogenesis	↑LDL transcytosis	↓IRS-1 phosphorylation ↑Insulin-resistance ↑Hepatic fibrogenesis
IL-1	↑Keratinocyte proliferation ↑Pro-inflammatory cytokine production ↑Expression of vascular endothelial cell adhesion molecules	↑Synthesis of IL-6, fibrinogen, RCP ↑Expression of adhesion molecules (ICAM, VCAM)	↑Activation of MAP and ERK pathways
IL-6	↑Pro-inflammatory cytokines (TNF-alpha, IL-1, IL-17) ↑Dermal and epidermal cell growth and differentiation ↑T cell migration into the epidermis	↑Pro-inflammatory cytokine production	↑Insulin-resistance ↓Hepatic cytokine signaling-3
Leptin	↑Keratinocyte proliferation ↑Promotes Th1 responses ↑Angiogenesis	↑Vascular smooth muscle cell migration and proliferation ↑Synthesis of TNF-alpha	↑Activation of JAK-2/IRS-2/PI3-K/Akt pathways ↑Leptin resistance ↑Hepatic fibrogenesis
Adiponectin	↑Anti-inflammatory cytokine production (Reduced levels in PsO)	↑Endothelial NO production ↑Endothelial dysfunction (Reduced levels in CVD)	↑Insulin sensitivity (Reduced levels in NAFLD)
Resistin	↑Pro-inflammatory cytokine production	↑Arterial inflammation ↑Vascular smooth muscle cell proliferation ↑Endothelial dysfunction	↑Insulin resistance (controversial data on NAFLD)
Visfatin	↑	↑	↑Protection against liver injury (not altered in the early stage)
IL-17	↑Pro-inflammatory cytokine production ↑Expression of vascular endothelial cell adhesion molecules	↑Atherosclerotic plaque vulnerability	↑Hepatic steatosis ↑Synthesis of pro-inflammatory cytokines
VEGF	↑Keratinocyte proliferation ↑Angiogenesis	↑	↑Microvascular changes implicated in the hepatic disease (fibrosis to cirrhosis)

CVD: Cardiovascular disease; NAFLD: Non-alcoholic fatty liver disease; LDL: Low-density lipoprotein; IRS-1: Insulin receptor substrate 1; MAPK: Mitogen-activated protein; ERK: Extracellular signal-regulated kinase; JAK: Janus kinase-signal transducers; VEGF: Vascular endothelial growth factor; IL: Interleukin; TNF: Tumor necrosis factor.