Prolyl Hydroxylase Research Articles

P4HA3 depletion induces ferroptosis and inhibits colorectal cancer growth by stabilizing ACSL4 mRNA.

Colorectal cancer (CRC) is a malignancy with high global incidence and mortality rates, posing a serious threat to human health. Despite favorable outcomes following early detection and surgical intervention, the asymptomatic nature of CRC often results in delayed diagnoses, limiting surgical treatment options. Furthermore, effective therapeutic drugs for CRC remain lacking in clinical practice, highlighting an urgent need to identify novel therapeutic targets. In this study, we identified that prolyl 4-hydroxylase subunit alpha 3 (P4HA3) is significantly upregulated in CRC and is associated with poor prognosis in patients. Both in vitro and in vivo experiments demonstrated that knockdown of P4HA3 induces ferroptosis, thereby inhibiting tumor growth. This ferroptosis induction is closely linked to increased lipid peroxidation, and P4HA3 knockdown promotes ferroptosis by upregulating acyl-CoA synthetase long-chain family member 4 (ACSL4), which regulates polyunsaturated fatty acid-containing phospholipids (PUFA-PLs) biosynthesis. Mechanistically, P4HA3 knockdown stabilizes ACSL4 mRNA by downregulating AUF1, an important RNA-binding protein (RBP) that binds to AU-rich elements (AREs) in the ACSL4 mRNA 3' untranslated region (UTR), thereby preventing its degradation. Additionally, given the lack of research on P4HA3 inhibitors, we employed virtual screening and identified Tubuloside A as a potential therapeutic agent. Tubuloside A promotes the ubiquitin-proteasome degradation of P4HA3, exerting anti-CRC effects. In summary, our findings demonstrate that P4HA3 protects CRC cells from ferroptosis by regulating ACSL4 mRNA stability via AUF1, and Tubuloside A serves as a potential P4HA3 degrader, offering a promising therapeutic strategy for CRC treatment.

Bioanalysis, Analysis, Chemistry, and Pharmacological Aspects of Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitors.

The development of Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitors (HIFPHIs), such as Roxadustat (ROX), Enarodustat (ENA), Desidustat (DES), Vadadustat (VAD), Molidustat (MOL), and Daprodustat (DAP), has significant effects on anemia in chronic kidney disease. This review presents comprehensive information about the synthesis, pharmacology, and analysis of HIF-PHIs across several matrices. The literature has presented several approaches for quantifying HIF-PHIs in diverse sample matrices. Furthermore, HIF-PHIs exhibit similar modes of action, demonstrating distinct pharmacokinetic parameters. The pharmacological insights encompass their half-life, mechanism of action, absorption, distribution, metabolism, excretion, and therapeutic uses. Research indicates that most studies concentrate on hyphenated methodologies for drug estimation in various biological fluids. Consequently, this study assesses the biological efficacy of HIF-PHIs and elucidates the analytical methodologies currently employed for measurement across various matrices.

Inhibition of HIF-prolyl hydroxylase promotes renal tubule regeneration via the reprogramming of renal proximal tubular cells.

The ability of the mammalian kidney to repair or regenerate after acute kidney injury (AKI) is very limited. The maladaptive repair of AKI promotes progression to chronic kidney disease (CKD). Therefore, new strategies to promote the repair/regeneration of injured renal tubules after AKI are urgently needed. Hypoxia has been shown to induce heart regeneration in adult mice. However, it is unknown whether hypoxia can induce kidney regeneration after AKI. In this study, we used a prolyl hydroxylase domain inhibitor (PHDI), MK-8617, to mimic hypoxic conditions and found that MK-8617 significantly ameliorated ischemia reperfusion injury (IRI)-induced AKI. We also showed that MK-8617 dramatically facilitated renal tubule regeneration by promoting the proliferation of renal proximal tubular cells (RPTCs) after IRI-induced AKI. We then performed bulk mRNA sequencing and discovered that multiple nephrogenesis-related genes were significantly upregulated with MK-8617 pretreatment. We also showed that MK-8617 may alleviate proximal tubule injury by stabilizing the HIF-1α protein specifically in renal proximal tubular cells. Furthermore, we demonstrated that MK-8617 promotes the reprogramming of renal proximal tubular cells to Sox9+ renal progenitor cells and the regeneration of renal proximal tubules. In summary, we report that the inhibition of prolyl hydroxylase improves renal proximal tubule regeneration after IRI-induced AKI by promoting the reprogramming of renal proximal tubular cells to Sox9+ renal progenitor cells.

Non-canonical Function of Prolyl Hydroxylase Domain 2 in Breast Cancer Cell Growth and Progression: Role of Peptidyl-prolyl Cis-trans Isomerase NIMA-interacting 1.

Prolyl hydroxylase domain 2 (PHD2) is the primary oxygen sensing enzyme involved in hydroxylation of hypoxia-inducible factor (HIF). Under normoxic conditions, PHD2 hydroxylates specific proline residues in HIF-1α and HIF-2α, promoting their ubiquitination and subsequent proteasomal degradation. Although PHD2 activity decreases in hypoxia, notable residual activity persists, but its function in these conditions remains unclear. Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) targets proteins with phosphorylated serine/threonine-proline (pSer/Thr-Pro) motifs. As PHD2 contains several pSer/Thr-Pro motifs, it may be a potential substrate of Pin1. In the present study, we found Pin1 and PHD2 interactions in human breast cancer MDA-MB-231 cells. The breast cancer tissue array revealed higher levels of PHD2 and Pin1 in tumors compared to adjacent normal tissues. Through liquid chromatography-tandem mass spectrometry spectrometry, three phosphorylation sites (S125, T168, and S174) on PHD2 were identified, with serine 125 as the main site for Pin1 binding. As a new Pin1 binding partner, oncogenic PHD2 could be a potential therapeutic target for breast cancer treatment.

Prolyl hydroxylase domain inhibitors prevent kidney crystal formation by suppressing inflammation.

The early stages of kidney crystal formation involve inflammation and hypoxia-induced cell injury; however, the role of the hypoxic response in kidney crystal formation remains unclear. This study investigated the effects of a prolyl hydroxylase domain inhibitor (roxadustat) on renal calcium oxalate (CaOx) crystal formation through in vitro and in vivo approaches. In the in vitro experiment, murine renal tubular cells (RTCs) were exposed to varying roxadustat concentrations and CaOx crystals. CaOx monohydrate (COM) crystal adhesion was evaluated using fluorescent labels, whereas western blotting was used to examine protein expression. Quantitative real-time polymerase chain reaction was used to analyze gene expression changes. Macrophage responses were investigated by co-culturing them with RTCs treated with COM. In the in vivo experiment, C57BL/6J mice were injected with roxadustat or saline for 2days, followed by glyoxylate for 6days to induce renal crystal deposition. Biochemical measurements recorded plasma erythropoietin, urinary data, and pH levels. Roxadustat suppressed the adhesion of COM crystals to RTCs and the expression of proinflammatory genes, such as chemokine (C-C motif) ligand 2 (Ccl2) and secreted phosphoprotein 1 (Spp1). Roxadustat decreased the expression levels of Ccl2, tumor necrosis factor (Tnf), and interleukin6 (Il6) in co-cultured macrophages. In the in vivo experiment, the amount of renal CaOx crystal deposits was significantly lower in the roxadustat-treated group than in the vehicle group. Roxadustat treatment decreased Ccl2, Tnf, and adheision G protein-coupled receptor E1 (Adgre1) expression in the kidneys. Roxadustat reduced kidney inflammation and CaOx crystal deposition, suggesting its potential as a therapeutic option for kidney stone prevention.

The role and clinical implications of HIF-PHI daprodustat in dialysis-dependent and non-dialysis-dependent chronic kidney disease anemic patients: a general review

Chronic kidney disease (CKD) patients often suffer from complications such as anemia as the kidney function declines. More than 25% of CKD hemodialysis patients in China are complicated with renal anemia due to renal and hepatic impairment in the production of erythropoietin (EPO). In recent years, prolyl hydroxylase domain (PHD) inhibitors have been approved in China and Japan for the treatment of CKD patients complicated with anemia. Daprodustat is a novel orally administrated active hypoxia-induced factor-prolyl hydroxylase inhibitor (HIF-PHI) that may improve quality of life and ischemic conditions such as peripheral arterial disease (PAD), stimulate the synthesis of endogenous EPO, and can effectively induce the production of red blood cells. It has been shown to increase EPO levels, which can lead to an increase in hemoglobin (Hgb), hematocrit, and red blood cell counts. Clinical studies have shown its effectiveness in dialysis and non-dialysis CKD anemic patients. In this literature review, we will focus on the mechanism and metabolism of the drug as well as its clinical applications in dialysis and non-dialysis CKD patients and summarize the adverse reactions.

Hypoxia-induced translation of collagen-modifying enzymes PLOD2 and P4HA1 is dependent on RBM4 and eIF4E2 in human colon cancer HCT116 cells.

Hypoxia is a critical microenvironmental factor that induces tumorigenesis and cancer progression, including metastasis. The highly dynamic nature of the extracellular matrix (ECM) plays a crucial role in metastasis. Collagens are the predominant component of structural proteins embedded within the ECM. The biosynthesis of collagen typically undergoes a series of posttranslational modifications, such as hydroxylation of lysine and proline residues by procollagen-lysine, 2-oxoglutarate 5-dioxygenases (PLODs) and prolyl 4-hydroxylases (P4Hs), respectively. Collagen hydroxylation is critical for ECM remodeling and maintenance. We recently investigated hypoxia-induced translation in human colon cancer HCT116 cells and identified several collagen-modifying enzymes, including procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2 (PLOD2) and prolyl 4-hydroxylase subunit alpha 1 (P4HA1). Although the translation of bulk mRNAs is repressed in hypoxia, specific mRNAs remain efficiently translated under such conditions. We have found that PLOD2 and P4HA1 are significantly upregulated in hypoxic HCT116 cells compared to normoxic cells. HIF-1 is known to induce the transcription of PLOD2 and P4HA1 during hypoxia. However, the molecular mechanisms of hypoxia-induced translation of PLOD2 and P4HA1 remain largely unclear. We provide evidence that RBM4 and eIF4E2 are required for hypoxia-induced translation of PLOD2 and P4HA1 mRNAs. The 3' UTRs of PLOD2 and P4HA1 mRNAs are involved in translational control during hypoxia in HCT116 cells.

Proteomics for Biomarker Discovery in Gynecological Cancers: A Systematic Review.

The present study aims to summarize the current biomarker landscape in gynecological cancers (GCs) and incorporate bioinformatics analysis to highlight specific biological processes. The literature was retrieved from PubMed, Web of Science, Embase, Scopus, Ovid Medline, and Cochrane Library. The final search was conducted on December 7, 2022. Prospective registration was completed with the PROSPERO with registration number CRD42023477145. This systematic review covered proteomic research on biomarkers for cervical, endometrial, and ovarian cancers. The PANTHER classification system was used to classify the shortlisted candidate biomarkers (CBs), and the STRING database was utilized to visualize protein-protein interaction networks. A total of 23 articles were included in this systematic review. Consistently regulated CBs in the GCs include collagen alpha-2(I) chain, collagen alpha-1(III) chain, collagen alpha-2(V) chain, calreticulin, protein disulfide-isomerase A3, heat shock protein family A (Hsp70) member 5, prolyl 4-hydroxylase, beta polypeptide, fibrinogen alpha chain, fibrinogen gamma chain, apolipoprotein B-100, apolipoprotein C-IV, and apolipoprotein M. In conclusion, collagens, fibrinogens, chaperones, and apolipoproteins were revealed to be replicated in GCs and to be regulated consistently. These CBs contribute to GC etiology and physiology by participating in collagen fibril organization, blood coagulation, protein folding in endoplasmic reticulum, and lipid transporter activity.

Crosslinking-mediated Interactome Analysis Identified PHD2-HIF1α Interaction Hotspots and the Role of PHD2 in Regulating Protein Neddylation.

Prolyl Hydroxylase Domain protein 2 (PHD2) targets Hypoxia Inducible Factor alpha subunits (HIFα) for oxygen-dependent proline hydroxylation that leads to subsequent ubiquitination and degradation of HIFα. In addition to HIF proteins, growing evidence suggested that PHD2 may exert its multifaceted function through hydroxylase-dependent or independent activities. Given the critical role of PHD2 in diverse biological processes, it is important to comprehensively identify potential PHD2 interacting proteins. In this study, we engineered HeLa cells that stably express HTBH-tagged PHD2 to facilitate the identification of PHD2 interactome. Using DSSO-based cross-linking mass spectrometry (XL-MS) technology and LC-MS n analysis, we mapped PHD2-HIF1α interaction hotspots and identified over 300 PHD2 interacting proteins. Furthermore, we validated the COP9 Signalosome (CSN) complex, a major deneddylase complex, as a novel PHD2 interactor. DMOG treatment promoted interaction between PHD2 and CSN complex and enhanced the deneddylase activity of the CSN complex, resulting in increased level of free Cullin and reduced target protein ubiquitination. This mechanism may serve as a negative feedback regulation of the HIF transcription pathway.

Intestinal mucosal barrier repair and immune regulation with an AI-developed gut-restricted PHD inhibitor.

Hypoxia-inducible factor prolyl hydroxylase (PHD) inhibitors have been approved for treating renal anemia yet have failed clinical testing for inflammatory bowel disease because of a lack of efficacy. Here we used a multimodel multimodal generative artificial intelligence platform to design an orally gut-restricted selective PHD1 and PHD2 inhibitor that exhibits favorable safety and pharmacokinetic profiles in preclinical studies. ISM012-042 restores intestinal barrier function and alleviates gut inflammation in multiple experimental colitis models.

Hypoxia-inducible factor prolyl hydroxylase inhibitor-induced thrombosis leading to transcatheter aortic valve dysfunction: a case report

Abstract Background Transcatheter aortic valve replacement (TAVR) is a well-established treatment option for patients with severe aortic valve stenosis; however, clinical valve thrombosis is a major challenge. Case summary A 92-year-old woman underwent TAVR for severe aortic stenosis. One month later, the patient developed acute heart failure. As the progression of anaemia due to renal anaemia seemed to cause acute heart failure exacerbation, we started an oral hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor. After 2 weeks, the patient redeveloped shortness of breath. Transthoracic echocardiography revealed that the mean aortic valve pressure gradient (ΔP) increased from 9 to 54 mmHg, and the aortic valve area decreased from 1.93 to 0.86 cm2. Blood work revealed a markedly elevated haemoglobin level from 8.0 to 13.2 g/dL, and transoesophageal echocardiography revealed markedly decreased left coronary and non-coronary cusp mobility. We diagnosed that the rapid increase in the haemoglobin level caused by the HIF-PH inhibitor was related to valve thrombosis and bioprosthetic dysfunction of the transcatheter aortic valve. The HIF-PH inhibitor was discontinued, and anticoagulation therapy was started. Transthoracic echocardiography at 16 days later revealed that the mean aortic valve ΔP improved by 15 mmHg, and the subjective symptoms resolved. Discussion This is the first report on a successful treatment of TAVR thrombosis formation associated with HIF-PH inhibitor use. When treating renal anaemia in patients undergoing TAVR, care should be taken to avoid rapid anaemia resolution and valve thrombosis development.

Effects of Roxadustat on Thyroid Profiles in Patients and Animals with Chronic Kidney Disease

Introduction: Roxadustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor used in renal anemia treatment, has been associated with thyroid hormone suppression. This study investigated the patterns of thyroid profile changes following roxadustat administration and their clinical implications. Methods: In this retrospective study (2019–2023) at Shenzhen Second People’s Hospital, patients were categorized based on thyroid-stimulating hormone (TSH) reduction during follow-up (≥50% decrease vs. <50% decrease). Thyroid profiles, clinical symptoms, and laboratory indicators were analyzed. Quality of life was assessed using EQ-5D-3L and ThyPRO questionnaires. Complementary animal experiments were conducted to verify the effects of roxadustat on thyroid function. Results: A total of 118 patients were finally enrolled in our study. Among patients with initially normal thyroid function, 31 developed euthyroid sick syndrome post-roxadustat treatment. Treatment significantly decreased TT3, FT3, FT4, and TSH levels, with TSH showing marked reduction within the first 10 weeks. Contrastingly, animal models exhibited decreased T3 but increased TSH levels, regardless of renal status. Blood lipid levels decreased in all patients, particularly in those with substantial TSH reduction. Despite thyroid alterations, quality-of-life scores remained unchanged between roxadustat-treated and untreated patients, with no overt clinical symptoms in either humans or animals. Conclusion: While roxadustat induces significant thyroid hormone suppression in patients, these alterations rarely manifest as clinical symptoms. Euthyroid sick syndrome is the predominant thyroid dysfunction pattern observed. Regular thyroid function monitoring is recommended during roxadustat therapy, particularly during the initial treatment phase when TSH changes are most pronounced.

Anemia, iron metabolism, and anemia medication habits in patients undergoing maintenance hemodialysis and peritoneal dialysis are different: a multicenter investigation.

This study aimed to investigate anemia, iron metabolism status, and treatment in patients undergoing maintenance hemodialysis (HD) and peritoneal dialysis (PD). Patients aged ≥ 18years undergoing HD and PD were surveyed using a case report form to collect information. Data were collected from 1071 patients undergoing HD and 630 undergoing PD at eight centers. Anemia was observed in 96.2% of the patients (96.7% for HD vs. 95.2% for PD, P = 0.121). Of these, 38.3% had hemoglobin (Hb) levels between 110 and 130g/L (41.2% for HD vs. 33.3% for PD, P < 0.001), 22.8% had absolute iron deficiency (ID) (31.2% for HD vs. 8.4% for PD, P < 0.001), and 5.8% had functional ID (4.7% for HD vs. 7.6% for PD, P = 0.012). Among patients with Hb < 110g/L, 13.0% received no treatment with erythropoiesis-stimulating agents (ESAs, all recombinant human erythropoietin) or hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHI, all roxadustat) (12.6% for HD vs. 13.6% for PD, P = 0.667), while 64.6% had no iron treatment (69.4% for HD vs. 57.4% for PD, P < 0.001). Logistic regression was used to explore the relationship between dialysis mode and hemoglobin target achievement, suggesting that the attainment of hemoglobin targets may be associated with the use of ESAs or HIF-PHI. Anemia, iron metabolism, and medication habits have distinct characteristics in patients undergoing HD and PD. Iron deficiency is prevalent, and achieving hemoglobin targets is suboptimal, possibly influenced by the administration of ESAs or HIF-PHI. Therefore, timely adjustments of medication habits are necessary to prevent anemia exacerbation.

Hypoxia-inducible factor activators: a novel class of oral drugs for the treatment of anemia of chronic kidney disease.

Anemia is a hallmark of chronic kidney disease (CKD), worsens with disease progression, and profoundly affects a patient's well-being. Major pathogenic factors are inadequate kidney erythropoietin (EPO) production and absolute and functional iron deficiency. The 2 mainstays of current anemia treatment are a) replacement therapy with recombinant EPO or 1 of its glycosylated derivatives, administered subcutaneously or intravenously, and b) intravenous (IV) iron injections. Over the past 5 years, hypoxia-inducible factor (HIF)-prolyl hydroxylase inhibitors (HIF-PHIs) have been approved in many countries for the management of anemia in both nondialysis and dialysis-dependent patients with CKD. Due to cardiovascular safety concerns, only 2 HIF-PHIs, daprodustat and vadadustat, have been approved for marketing in the United States, and only for patients on maintenance dialysis. HIF-PHIs are oral agents that are effective at improving and maintaining hemoglobin levels by activating HIF signaling in anemic patients with CKD. They stimulate the production of endogenous EPO, increase total iron-binding capacity through their direct effects on transferrin gene transcription, lower plasma hepcidin indirectly, and have beneficial effects on red blood cell parameters. Here, we discuss the mechanisms of action and pharmacologic properties of different HIF-PHIs. We discuss unwanted on-target and off-target effects, review cardiovascular and other safety concerns, and provide a benefit/risk-based perspective on how this new class of oral drugs might impact current anemia management in CKD. A clinical case is presented that highlights the clinical complexities and therapeutic challenges in managing anemia in CKD.

Targeting P4HA1 promotes CD8+ Tcell progenitor expansion toward immune memory and systemic anti-tumor immunity.

Successful immunotherapy relies on both intratumoral and systemic immunity, which is yet to be achieved for most patients with cancer. Here, we identify P4HA1, encoding prolyl 4-hydroxylase 1, as a crucial regulator of CD8+ Tcell differentiation strongly upregulated in tumor-draining lymph nodes (TDLNs) and hypoxic tumor microenvironment. P4HA1 accumulates in mitochondria, disrupting the tricarboxylic acid (TCA) cycle through aberrant α-ketoglutarate and succinate metabolism, promoting mitochondria unfitness and exhaustion while suppressing progenitor expansion. Targeting P4HA1 enhances both adoptive and endogenous TCF1+ CD8+ T progenitor expansion while mitigating the development of exhaustion in the tumor, TDLN, and blood, enabling a notable and durable systemic anti-cancer immunity. We propose that P4HA1 induction in CD8+ Tcells in cancer orchestrates an immune-escape program, offering a Tcell-directed target for system immunotherapy in solid tumors.

Post-ischemic inactivation of HIF Prolyl Hydroxylases in endothelium promotes maladaptive kidney repair by inducing glycolysis.

Ischemic acute kidney injury (AKI) is common in hospitalized patients and increases the risk for chronic kidney disease (CKD). Impaired endothelial cell (EC) functions are thought to contribute in AKI to CKD transition, but the underlying mechanisms remain unclear. Here, we identify a critical role for endothelial oxygen sensing prolyl hydroxylase domain (PHD) enzymes 1-3 in regulating post-ischemic kidney repair. In renal endothelium, we observed compartment-specific differences in the expression of the three PHD isoforms in both mice and humans. Post-ischemic concurrent inactivation of endothelial PHD1, PHD2, and PHD3 but not PHD2 alone promoted maladaptive kidney repair characterized by exacerbated tissue injury, fibrosis, and inflammation. Single-cell RNA-seq analysis of the post-ischemic endothelial PHD1, PHD2 and PHD3 deficient (PHDTiEC) kidney revealed an endothelial hypoxia and glycolysis related gene signature, also observed in human kidneys with severe AKI. This metabolic program was coupled to upregulation of the SLC16A3 gene encoding the lactate exporter monocarboxylate transporter 4 (MCT4). Strikingly, treatment with the MCT4 inhibitor syrosingopine restored adaptive kidney repair in PHDTiEC mice. Mechanistically, MCT4 inhibition suppressed pro-inflammatory EC activation reducing monocyte-endothelial cell interaction. Our findings suggest avenues for halting AKI to CKD transition based on selectively targeting the endothelial hypoxia-driven glycolysis/MCT4 axis.

Successful treatment of low-risk myelodysplastic syndrome-related anemia in patients with chronic kidney disease with daprodustat: A report of two cases.

Anemia is a major clinical manifestation seen in myelodysplastic syndromes (MDS). Treatment options for anemia in low-risk MDS are limited. Especially, oral medication which is uniformly effective for anemia in low-risk MDS is required. Hypoxia-inducible factor (HIF) prolyl hydroxylase (HIF-PH) inhibitors, such as daprodustat, are oral tablets effective for renal anemia. Pharmacological restoration of HIF activity by HIF-PH inhibitors may be beneficial for MDS-related anemia as well. Yet, their efficacy and safety against low-risk MDS are unclear. Here, we report two cases of low-risk MDS complicated with chronic kidney disease whose anemia responded to daprodustat treatment.

Erythrocyte indices and response to hypoxia-inducible factor prolyl hydroxylase inhibitors in chronic kidney disease patients with renal anemia: a retrospective study

BackgroundAlthough erythropoiesis-stimulating agents (ESAs) have been the standard treatment for renal anemia, ESA hyporesponsiveness remains a concern. Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) are a new class of agents indicated for renal anemia. Several lines of evidence indicate that HIF-PHIs affect erythrocyte indices; nonetheless, their clinical significance remains unclear.MethodsWe retrospectively analyzed data from 233 non-dialysis-dependent chronic kidney disease patients who initiated either ESA (darbepoetin) or HIF-PHI for the treatment of anemia. We analyzed the changes in hemoglobin levels three months after the initiation of anti-anemic treatments, examining their association with changes in erythrocyte indices.ResultsBoth ESA and HIF-PHIs significantly increased hemoglobin levels after three months of treatment. In the HIF-PHI group, the increase in hemoglobin levels was positively correlated with the increase in mean corpuscular volume (MCV) levels, a finding that was not observed in the ESA group. In a subgroup analysis based on the mean reference range value for MCV (90.9 fL), a significant difference in the proportion of patients with improved anemia was observed between ESA and HIF-PHIs in patients with lower MCV values. Logistic regression and interaction analyses confirmed that there was a significant interaction between baseline MCV values and the effectiveness of anti-anemic drugs, independently of other covariates.ConclusionsAn increase in hemoglobin levels is associated with an increase in MCV in patients treated with HIF-PHIs. The anti-anemic effects of ESA and HIF-PHIs may be influenced by baseline MCV values. However, long-term consequences need further evaluation.

Inhibition of alternative complement system and prolyl hydroxylase ameliorates anaemia of inflammation.

Chronic diseases associated with inflammation cause early destruction of RBCs. Complement system, part of innate immunity, is involved in such RBC destruction. Persistent inflammation causes kidney injury, leading to reduced erythropoietin release and functional iron deficiency, causing anaemia. We have investigated effect of iptacopan, a factor B inhibitor, and desidustat, a prolyl hydroxylase inhibitor in anaemia induced by peptidoglycan polysaccharide (PGPS) treatment in rats. Inflammation, haemolysis and its diagnostic markers (LDH, total bilirubin, and RBC lifespan) were evaluated after three days of PGPS challenge. Haemoglobin, RBC, iron homeostasis, and RBC destruction were evaluated fourteen days after PGPS challenge. Desidustat (15mg/kg) and iptacopan (20mg/kg) were given along with PGPS and continued for two weeks. Iptacopan and its combination with desidustat prevented LDH, total bilirubin, complement protein-C3a and haemolysis. Combination treatment caused an early normalization of haemoglobin and RBC. Combination also reduced WBC, alkaline phosphatase, aspartate aminotransferase, and rat paw volume. Serum iron was increased by desidustat and its combination treatment. Spleen weight, tissue iron, and serum hepcidin were reduced by combination treatment. Effect of desidustat alone was prominent on iron (serum and tissue) and hepcidin. Thus, combination of iptacopan and desidustat can be a potentially useful therapeutic option for treatment of anaemia of inflammation.

Efficacy and safety of daprodustat in patients on peritoneal dialysis in the ASCEND-D trial.

Daprodustat, an oral hypoxia-inducible factor prolyl hydroxylase inhibitor, is approved for treatment of anemia in dialysis patients with CKD in some parts of the world. This subgroup analysis examined the efficacy and safety of daprodustat versus darbepoetin alfa in patients with anemia of CKD undergoing peritoneal dialysis (PD). ASCEND-D (NCT02879305) was an open-label, Phase 3 trial; patients with CKD were randomized to daprodustat daily and epoetin alfa (HD patients) or darbepoetin alfa (PD patients). In PD patients, prespecified analyses of the co-primary endpoints of mean change in hemoglobin from baseline to Weeks 28-52 using an ANOVA model and first occurrence of a major cardiovascular event (MACE) using a Cox proportional hazards model were conducted. The secondary endpoints were average monthly intravenous iron dose to Week 52 and treatment-emergent adverse events. Additional post hoc analyses were conducted. Overall, 340 PD patients (daprodustat n=171, darbepoetin alfa n=169) were randomized. Mean age was 53.6 years (±14 SD), 55% male, 56% White. For daprodustat and darbepoetin alfa groups respectively, mean change in hemoglobin was 0.38 and 0.23g/dL [adjusted mean difference 0.15, 95% confidence interval (CI), -0.04, 0.34], and first occurrence of adjudicated MACE occurred in 40 (23.4%) and 46 (27.2%) patients (HR 0.84; 95% CI, 0.55-1.28). No heterogeneity was observed between PD and HD patients for these endpoints in ASCEND-D. Serum hepcidin was lower with daprodustat; there was no difference in other iron parameters, intravenous iron usage, transfusion requirement, blood pressure, or quality of life. There were no differences in adverse events or incidence of peritonitis between the groups. This subgroup analysis of the ASCEND-D trial demonstrated comparable efficacy and safety of daprodustat versus darbepoetin alfa in PD patients, supporting its use in the treatment of anemia in these patients.