Protective Effect And Mechanism Of Monascus Pigment On Glomerular Endothelial Cells

Monascus pigment is a kind of natural microbial pigment with good antioxidant activity,which has various beneficial effects such as anti-inflammatory,antioxidant,antidiabetic,immune regulation,alleviation of Alzheimer’s disease risk factors and antitumor.Diabetic nephropathy(DN)is a common chronic complication of diabetes,and its occurrence and development mechanism are still inconclusive.Human glomerular endothelial cells(HRGECs)are the first barrier to the glomerular filtration membrane.Sustained high glucose conditions can damage glomerular endothelial cells.In this paper,we aimed to explore the protective effect of monascus pigment on glomerular endothelial cells and its mechanism by establishing two HRGEC injury models of H2O2 injury and high glucose injury.In this paper,we compared the in vitro antioxidant activities of various Monascus pigments by DPPH,ABTS free radical scavenging experiments and total antioxidant capacity assays.By establishing H2O2-induced HRGEC oxidative damage model,we screened out Monascin(MS)and Ankaflavin(AK)with better anti-oxidative damage effects.Then we used H&E staining and Hoechst staining to observe the morphology of H2O2-damaged HRGEC before and after MS and AK protection.We then used ROS staining and determination of SOD,GSH,MDA,T-AOC and other antioxidant indicators to understand the effect of MS and AK on the oxidative stress level of HRGEC in oxidative damage.After that,we established a high-glucose injury model to observe the protective effects of MS and AK on HRGECs damaged by high-glucose,and to detect the expression of antioxidant proteins and apoptotic proteins.Finally,we screened the differentially expressed genes in the glomerular cells of diabetic mice by bioinformatics analysis,and determined the expression of related pathway proteins and key factors,thereby revealing the potential mechanism of MS and AK in protecting HRGEC from high glucose-induced injury.The results showed that MS and AK could maintain the normal morphology of glomerular endothelial cells and alleviate the oxidative damage of glomerular endothelial cells caused by H2O2 and high glucose.MS and AK can increase the membrane potential of HRGEC and reduce the apoptotic ratio from 25%to 10%.And they can increase the activity of antioxidant enzymes and antioxidant levels in cells,reduce the level of oxidative products,and improve the total antioxidant capacity.MS and AK can also alleviate the dysfunction of glomerular endothelial cells induced by high glucose.Through bioinformatics analysis,we found that the key factors of glomerular endothelial cell injury in DN mice are cell adhesion factors and inflammatory factors,and found that MS and AK can protect glomerular endothelial cells by reducing the expression of these key factors.Conclusion:(1)Monascus pigment has good antioxidant ability in vitro.(2)MS and AK can protect glomerular endothelial cells from oxidative stress damage caused by H2O2 and improve the ability of cells to resist oxidative stress.(3)MS and AK can decrease the apoptosis of glomerular endothelial cells induced by high glucose by increasing mitochondrial membrane potential.(4)MS and AK can down-regulate the expression of related factors such as ICAM-1,Cxcl16 and Caspase-3,and increase the expression of antioxidant protein.In conclusion,under the protection of MS and AK,the activity and antioxidant capacity of oxidized glomerular endothelial cells were improved,mitochondrial function was protected,and apoptosis and inflammation were inhibited.This topic provides a new theoretical basis for the research on the anti-oxidation and anti-diabetic nephropathy of monascus pigment,and provides a theoretical reference for the development of monascus pigment as an antioxidant functional factor.