High Glucose Induces Endothelial COX2 and iNOS Expression via Inhibition of Monomethyltransferase SETD8 Expression

Figure 2

SET domain-containing protein 8 (SETD8) overexpression counteracted high glucose-induced cyclooxygenase 2 (COX2) and inducible nitric oxide synthase (iNOS) expression in human umbilical vein endothelial cells (HUVECs). (a, b) Western blot analysis of SETD8 and H4K20me1 in HUVECs cultured under normal or high glucose conditions. Compared with the control group, high glucose treatment decreased SETD8 and H4K20me1 protein expression in HUVECs. (c, d) Western blot analysis of SETD8, E26 transformation-specific sequence transcription factor-1 (ESE-1), iNOS, and COX2 in HUVECs overexpressing SETD8 under high glucose conditions. SETD8 overexpression inhibited ESE-1, iNOS, and COX2 protein expression in hyperglycaemic HUVECs. (e) qPCR analysis of SETD8, ESE-1, iNOS, and COX2 in HUVECs overexpressing SETD8 under high glucose conditions. SETD8 overexpression inhibited ESE-1, iNOS, and COX2 mRNA expression in hyperglycaemic HUVECs. (f) The effects of SETD8 overexpression on high glucose-mediated apoptosis in HUVECs. SETD8 overexpression decreased cell apoptosis in hyperglycaemic HUVECs. (g, h) Western blot analysis of SETD8, ESE-1, iNOS, and COX2 in HUVECs upon SETD8 silencing. Compared with the control group, shSETD8 increased ESE-1, iNOS, and COX2 protein expression in HUVECs. (i) qPCR analysis of SETD8, ESE-1, iNOS, and COX2 in HUVECs upon SETD8 silencing. Compared with the control group, shSETD8 increased ESE-1, iNOS, and COX2 mRNA expression in HUVECs. (j) Cell apoptosis analysis in HUVECs upon SETD8 silencing. Compared with the control group, shSETD8 increased cell apoptosis in HUVECs. SETD8 OE: SETD8 overexpression; shSETD8: short hairpin RNA SETD8. , compared with the control group; ^#, compared with high glucose treatment.

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