Acta Academiae Medicinae Sinica

Abstract:

Objective To investigate the role of family with sequence similarity 3A(Fam3A) in high glucose-induced damage of human umbilical vein endothelial cells (HUVECs). Methods HUVECs were divided into control group and high glucose group, which were cultured in endothelial cell medium (ECM) containing 5.5 mmol/L of glucose and ECM containing 33.3 mmol/L of glucose, respectively. Real-time quantitative polymerase chain reaction was used to detect the mRNA expression of Fam3A, whereas the protein expression of Fam3A was detected by enzyme-linked immunosorbent assay. HUVECs in control group and high glucose group were transfected with siNT and siFam3A, respectively, and the levels of reactive oxygen species(ROS), ATP, mitochondrial oxygen consumption rate(OCR), and P-p38 protein were detected.Results After HUVECs had been cultured for 24h, the relative mRNA expression of Fam3A between high glucose group and control group was 2.52±0.19 (t=13.296,P=0.000). The Fam3A protein level was (173.82±33.28)pg/ml in the high glucose group, which was significantly higher than that [(39.45±33.78)pg/ml] in the control group (t=4.907,P=0.006). The intracellular ROS content in siNT-high glucose group was (8217±794)RFU, which was significantly higher than that [(3982±398)RFU] in siNT control group (t=15.109,P=0.002). The intracellular ROS content of siFam3A high glucose group was (11 910±1 001)RFU, significantly higher than that [(4171±402)RFU] of siFam3A control group (t=9.705,P=0.010) and than that of siNT high glucose group (t=4.026,P=0.048). The relative amounts of ATP synthesis in siNT high glucose group, siFam3A control group and siFam3A high glucose group were (61.2±5.6)%, (94.6±8.4)%, and (29.7±2.7)% of the siNT control group respectively; thus, it was significantly lower in siNT high glucose group than in siNT control group (t=12.001,P=0.007) and was also significantly lower in siFam3A high glucose group than in siFam3A control group (t=20.742,P=0.002) and in siNT high glucose group(t=18.814,P=0.003). The mitochondrial OCR was (0.57±0.05)pMO₂/(μg protein·min) in siNT high glucose group, significantly lower than that [(1.12±0.09)pMO₂/(μg protein·min)] of siNT control group (t=6.804,P=0.021). The mitochondrial OCR of siFam3A high glucose group was (0.31±0.03)pMO₂/(μg protein·min), significantly lower than that [(1.01±0.09)pMO₂/(μg protein·min)] of siFam3A control group (t=19.876,P=0.003), which was significantly lower than that of siNT high glucose group (t=21.444,P=0.002). The relative expression of P-p38 in siNT high glucose group, siFam3A control group, and siFam3A high glucose group was 2.239±0.353, 0.816±0.120, and 1.160±0.185, respectively; thus, it was significantly higher in the siNT high glucose group than in siNT control group (t=6.075,P=0.026); in addition, it was significantly higher in the siFam3A high glucose group than in siFam3A control group (t=6.242,P=0.024) and significantly lower than in siNT high glucose group (t=9.686,P=0.010). Conclusions High glucose can induce high expression of Fam3A in HUVECs. Knockdown of Fam3A gene expression can exacerbate the decrease of ATP synthesis and mitochondrial OCR caused by high glucose and promote the generation of ROS in high glucose. Fam3A may regulate high glucose-induced ROS production in HUVECs via the p38 MAPK signaling pathway.

Key words: high glucose, human umbilical vein endothelial cells, family with sequence similarity 3A, reactive oxygen species, mitochondrial dysfunction