Pharmacological inhibition of prolyl hydroxylase protects against inflammation-induced anemia via efficient erythropoiesis and hepcidin downregulation
EUROPEAN JOURNAL OF PHARMACOLOGY
Authors: Jain, Mukul; Joharapurkar, Amit; Patel, Vishal; Kshirsagar, Samadhan; Sutariya, Brijesh; Patel, Maulik; Patel, Hiren; Patel, Pankaj R.
Abstract
Chronic inflammatory diseases are often associated with anemia. In such conditions, anemia is generally treated with erythropoiesis stimulating agents (ESAs) which are associated with potentially hazardous side effects and poor outcomes. Suboptimal erythropoiesis in chronic inflammation is believed to be caused by elevated hepcidin levels, which causes blockade of iron in tissue stores. In the current work using rodent models of inflammation, an orally available small molecule prolyl hydroxylase inhibitor desidustat was assessed as an effective treatment of anemia of inflammation. In BALB/c mice, a single dose treatment of desidustat attenuated the effect of lipopolysaccharide (LPS) - or turpentine oil-induced inflammation and increased serum erythropoietin (EPO), iron, and reticulocyte count, and decreased serum hepcidin levels. In turpentine oil-induced anemia in BALB/c mice, repeated dose desidustat treatment increased hemoglobin, RBC and hematocrit in a dose related manner. In female Lewis rats, treatment with desidustat markedly reduced PGPS-induced anemia and increased hemoglobin, red blood cell (RBC) and white blood cell (WBC) count, hematocrit, serum iron and spleen iron. These effects of desidustat were associated with reduction in hepcidin (HAMP) expression as well as reduction in serum hepcidin, and increased EPO expression in liver and kidneys. Desidustat treatment caused a significant increase in expression of Duodenal cytochrome B (DcytB), ferroportin (FPN1) and divalent metal transporter 1 (DMT1) in duodenum, and FPN1 and monocyte chemoattractant protein-1 (MCP-1) in liver suggesting an overall influence on iron metabolism. Thus, pharmacological inhibition of prolyl hydroxylase enzymes can be useful in treatment of anemia of inflammation.
DNA methylation suppresses liver Hamp expression in response to iron deficiency after bariatric surgery
SURGERY FOR OBESITY AND RELATED DISEASES
Authors: Huang, Yeping; Zhang, Hong; Wang, Chen; Zhou, Jian; Li, Yao; Hu, Cheng
Abstract
Background: Iron deficiency is extremely common after bariatric surgery. HEPCIDIN, encoded by Hamp, is a hormone that negatively regulates iron homeostasis. Objectives: We aimed to investigate the alteration of Hamp expression and related regulatory factors to explore the probable role of DNA methylation in modulating Hamp expression in the context of iron deficiency after bariatric surgery. Setting: Laboratories of Diabetes Institute. Methods: RNA-seq was performed using rat liver tissue after either Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy surgery to identify differentially expressed genes between the bariatric surgery and sham group. Hamp expression were measured by quantitative polymerase chain reaction and enzymelinked immunosorbent assay, respectively. The DNA methylation level was determined using MassAR-RAY EpiTYPER. Iron status, erythrocyte parameters, and inflammation factors were assessed. Results: RNA-seq data showed that liver Hamp expression changed most dramatically in RYGB-operated rats. Both the mRNA expression of Hamp and the abundance of its protein product HEPCIDIN-25 decreased markedly after bariatric surgery compared with sham, while sleeve gastrectomy-operated rats showed marginally higher Hamp expression than RYGB-operated rats. The DNA methylation level of the Hamp promoter region was significant higher in RYGB-operated rats than sham, while sleeve gastrectomy rats increased slightly in DNA methylation. Consistent with the change of HEPCIDIN-25, serum iron was significantly lower for both bariatric groups than sham and particularly low in RYGB. Conclusions: Our data demonstrate that elevated DNA methylation of the Hamp promoter region suppresses its expression, this epigenetic modification likely occurs in reaction to iron deficiency after bariatric surgery, helping to maintain system iron homeostasis. (C) 2019 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.