The Effect Of Stable Hypoxia - Inducible Factor On The Treatment Of Chronic Kidney Anemia And Its Mechanism Of Regulation Of Related Target Genes

Part I Efficacy and Safety of Prolyl-hydroxylase Inhibitor in Non-dialysis Chronic Kidney Disease Patients with AnemiaObjective:Anemia is a common complication of chronic kidney disease. The use of intravenous erythropoietin has certain restrictions and adverse reactions. The purposes of this part was to evaluate the efficacy and safety of oral prolyl-hydroxylase inhibitor in non-dialysis chronic kidney disease in a randomized, controlled and double-blinded clinical study, and observed the variation of other laboratory parameters in the process of treatment.Method:15non-dialysis chronic kidney disease patients were recruited in the randomized, placebo-controlled and double-blinded clinical study. Subjects were randomly assigned in a2:1ratio to PHD inhibitor (FG-4592) or placebo. The treatment period maintained8weeks, and3weeks follow-up after that. Dosages were adjusted according to the hemoglobin levels after a certain treatment. The data such as every subject’s general condition, adverse reaction, Hb and hematocrit (Hct) were recorded once a week, and other laboratory indexes including reticulocyte (Rtc), iron metabolism parameters and blood lipid were followed regularly. The trial’s primary endpoint was the Hb level compared with that of the baseline at the8th week while the secondary endpoint was the changes of Hct, iron metabolism parameters and blood lipid, etc. Safety assessment included adverse events, serious adverse events, cardiovascular adverse events, and participants who had significant changed laboratory values.Results:The baseline data matched well between the two groups. After the process of treatment, the average Hb of study group was11.1±1.1g/dL, and that of placebo group was9.1±0.8g/dL, P=0.004; the average Hct of study group was37.7±3.9%, and that of placebo group was29.2±2.6%, P=0.001; the average Rtc of study group was1.7±0.7%, and that of placebo group was1.4±0.6%, P=0.409, and the increased values were0.7±0.7%and-0.1±0.6%respectively, P=0.042(the4th week); the average cholesterol of study group was3.8+1.2mmol/L, and that of placebo group was5.4±1.0mmol/L, P=0.024; the average LDL-C of study group was2.4±0.9mmol/L, and that of placebo group was3.5±1.0mmol/L, P=0.040; the average transferring saturation of study group was16.8±6.7%, and that of placebo group was26.9±5.9%, P=0.013; the average TIBC of study group was62.2±15.2μ mol/L, and that of placebo group was41.5±4.6mmol/L, P=0.012; the average transferrin of study group was40.5±10.5μ mol/L, and that of placebo group was27.3±3.2μ mmol/L, P=0.018; the average ferritin of study group was85.0±118.1μ g/L, and that of placebo group was272.2±91.1μ g/L, P=0.009; the average sTfR of study group was6.1±2.1mg/L, and that of placebo group was3.4±1.4mg/L, P=0.024. The above parameters revealed statistical differences between the two groups. No adverse events and cardiovascular adverse events happened, and there were no notable laboratory values changes.Conclusion:PHD inhibitor could remarkably improve the parameters about erythropoiesis, iron metabolism and blood lipid of non-dialysis chronic kidney disease subjects. No obvious adverse event occurred during the two months.Part II The Mechanism of Hypoxia-inducible Factor Regulating its Downstream Related Target Genes via MiRNAsObjective:To explore the mechanism of how HIF regulates its downstream factors by means of screening and identifying the differentially expressed miRNAs as well as their related target genes.Method:Plasma samples were collected after8weeks of treatment. After quality identification and fluorescent labeling, the RNA samples were hybridized with Agilent human miRNA microarrays. Raw data were normalized using Quantile algotithm and GeneSpring Software. Sanger database was used to predict target genes for differentially expressed miRNAs. Gene Ontology database, BIOCARTA and KEGG database were used for GO annotations and Pathway annotations of target genes, respectively.Results:A total of1347miRNAs were identified and among34were differentially expressed(fold change=≥2or≤0.5), including29up-regulated and5down-regulated.1527target gene were predicted for34differentially expressed miRNAs, and these genes were mainly involved in events, such as signal transduction, binding, proliferation, apoptosis, immune system and metabolic process. Pathways included Insulin/IGF-1signaling pathway, MAPK signaling pathway, VEGF signaling pathway, apoptosis, erythropoiesis and lipid metabolism. Among these, ABCA1(miR1202&miR1825), ACACA(miR1825), FASN (miR1280), ACOX1(miR92a) and ACSL3(miR223) were correlated with lipid metabolism in vivo. In the analysis, we considered the continuously stable HIF up-regulated the above miRNAs, which suppressed the downstream target genes, and eventually resulted in intracellular lipid deposition and impaired lipid efflux.Conclusion:HIF could indirectly regulate the target genes through adjustding the expressions of miRNAs. In lipid metabolism, HIF might regulate the process by means of miRNAs and the related target genes.