Roxadustat: Not just for anemia

How oxygenation shapes immune responses: emerging roles for physioxia and pathological hypoxia

Most eukaryotes require oxygen for their survival and, with increasing multicellular complexity, oxygen availability and delivery rates vary across the tissues of complex organisms. In humans, healthy tissues have markedly different oxygen gradients, ranging from the hypoxic environment of the bone marrow (where our haematopoietic stem cells reside) to the lungs and their alveoli, which are among the most oxygenated areas of the body. Immune cells are therefore required to adapt to varying oxygen availability as they move from the bone marrow to peripheral organs to mediate their effector functions. These changing oxygen gradients are exaggerated during inflammation, where oxygenation is often depleted owing to alterations in tissue perfusion and increased cellular activity. As such, it is important to consider the effects of oxygenation on shaping the immune response during tissue homeostasis and disease conditions. In this Review, we address the relevance of both physiological oxygenation (physioxia) and disease-associated hypoxia (where cellular oxygen demand outstrips supply) for immune cell functions, discussing the relevance of hypoxia for immune responses in the settings of tissue homeostasis, inflammation, infection, cancer and disease immunotherapy.

Roxadustat regulates the cell cycle and inhibits proliferation of mesangial cells via the hypoxia-inducible factor-1α/P53/P21 pathway

Background

Over-proliferation of mesangial cells (MCs) is one of the main pathological changes in the early stages of diabetic kidney disease (DKD). Roxadustat, an oral hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitor, is widely studied in different models of kidney disease. Whether roxadustat has beneficial effect on the proliferation of MCs and DKD remains unknown.

Methods

The optimal concentration of roxadustat for inhibiting MC proliferation was determined using CCK-8 and colony formation assays. Changes in the cell cycle were detected using flow cytometry, and changes in cell cycle-related proteins were screened using quantitative reverse transcription polymerase chain reaction. Reverse experiments were applied using Trp53-/- cell line. Co-immunoprecipitation was used to verify the interaction between HIF-1α and p53 and predict sites of interaction. Finally, a corresponding in vivo verification was performed.

Results

Optimal concentrations of high glucose (30 mM) and roxadustat (100 μM) were established. Roxadustat showed anti-proliferation effect on MCs through S-phase arrest. HIF-1α/p53/p21 and downstream cyclins (cyclin A1, cyclin A2, and cyclin E1) showed corresponding changes. A reverse experiment confirmed that HIF-1α affected cell cycle and proliferation through p53, and co-immunoprecipitation results showed a interaction between HIF-1α and p53. Molecular docking predicted the possible interaction between Lys328, Pro332, Arg245, and Lys251 of HIF-1α and Ala222, Tyr226, Glu225, and Asp265 of p53, respectively. Finally, animal experiments demonstrated similar effect of roxadustat in db/db mice.

Conclusion

Roxadustat regulates and inhibits cell proliferation of MCs via the HIF-1α/p53/p21 pathway. This may be a potential therapeutic target in the early stages of diabetic kidney disease.

Efficacy and Safety of Roxadustat in Patients with CKD: Pooled Analysis by Baseline Inflammation Status

Background/Objectives: Inflammation may contribute to hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) and is often present in patients with chronic kidney disease (CKD). Roxadustat is approved in multiple countries for the treatment of anemia of CKD. This pooled analysis evaluated the efficacy and safety of roxadustat in patients with dialysis-dependent (DD) or non-dialysis-dependent (NDD) CKD by inflammation status. Methods: Data from five studies comparing roxadustat versus ESAs were pooled by patient populations in this analysis (NDD: DOLOMITES; DD: ROCKIES, SIERRAS, HIMALAYAS, PYRENEES). The mean change from baseline in hemoglobin levels to Weeks 28-52 and mean weekly dose of roxadustat or ESA at Week 24 were assessed by baseline inflammation levels (determined by high-sensitivity C-reactive protein [hsCRP] levels, divided into quintiles). Safety data were summarized descriptively. Results: In total, 613 patients with NDD CKD (roxadustat n = 320; ESA n = 293) and 4072 patients with DD CKD (roxadustat n = 2022; ESA n = 2050) were evaluated. Roxadustat increased hemoglobin levels in a manner similar to ESAs, independent of baseline inflammation status. In both the NDD and DD populations, roxadustat doses did not increase at Week 24 in patients with higher hsCRP levels at baseline. Patients with high baseline hsCRP levels required greater ESA doses at Week 24 compared with patients who had lower baseline hsCRP levels in both patient populations. The incidence rates of treatment-emergent adverse events were generally comparable with those of roxadustat and ESA across hsCRP quintiles in both the NDD and DD populations. Conclusions: Roxadustat addresses the multiple causes of anemia of CKD, regardless of inflammatory status, without requiring dose increases.

Targeted therapies for myelodysplastic syndromes/neoplasms (MDS): current landscape and future directions

INTRODUCTION

Myelodysplastic syndromes/neoplasms (MDS) are a heterogeneous group of hematologic malignancies that are stratified into high-risk (HR-MDS) and low-risk (LR-MDS) categories. Until recently, LR-MDS has been typically managed by supportive measures and erythropoiesis-stimulating agents (ESAs); whereas management of HR-MDS typically included hypomethylating agents and allogeneic hematopoietic stem cell transplant. However, the limited rates and durations of response observed with these interventions prompted the search for targeted therapies to improve the outcomes among patients with MDS.

AREAS COVERED

Here, we review the current landscape of targeted therapies in MDS. These include pyruvate kinase and hypoxia-inducible factor (HIF) activators; TGF-beta, telomerase, BCL2 and isocitrate dehydrogenase (IDH) inhibitors; as well as novel approaches targeting inflammation, pyroptosis, immune evasion, and RNA splicing machinery.

EXPERT OPINION

This review highlights the progress and challenges in MDS treatment. Despite some promising results, many therapies remain in early development or have faced setbacks, emphasizing the need for a more comprehensive understanding of the disease's pathobiology. Continued research into targeted therapies, homogenous clinical trial designs, as well as increased incorporation of molecular prognostic tools and artificial intelligence into trial design are essential for developing effective treatments for MDS and improving patient outcomes.

Localized delivery of therapeutics impact laryngeal mechanics, local inflammatory response, and respiratory microbiome following upper airway intubation injury in swine

BACKGROUND

Laryngeal injury associated with traumatic or prolonged intubation may lead to voice, swallow, and airway complications. The interplay between inflammation and microbial population shifts induced by intubation may relate to clinical outcomes. The objective of this study was to investigate laryngeal mechanics, tissue inflammatory response, and local microbiome changes with laryngotracheal injury and localized delivery of therapeutics via drug-eluting endotracheal tube.

METHODS

A simulated traumatic intubation injury was created in Yorkshire crossbreed swine under direct laryngoscopy. Endotracheal tubes electrospun with roxadustat or valacyclovir- loaded polycaprolactone (PCL) fibers were placed in the injured airway for 3, 7, or 14 days (n = 3 per group/time and ETT type). Vocal fold stiffness was then evaluated with normal indentation and laryngeal tissue sections were histologically examined. Immunohistochemistry and inflammatory marker profiling were conducted to evaluate the inflammatory response associated with injury and ETT placement. Additionally, ETT biofilm formation was visualized using scanning electron microscopy and micro-computed tomography, while changes in the airway microbiome were profiled through 16S rRNA sequencing.

RESULTS

Laryngeal tissue with roxadustat ETT placement had increasing localized stiffness outcomes over time and histological assessment indicated minimal epithelial ulceration and fibrosis, while inflammation remained severe across all timepoints. In contrast, vocal fold tissue with valacyclovir ETT placement showed no significant changes in stiffness over time; histological analysis presented a reduction in epithelial ulceration and inflammation scores along with increased fibrosis observed at 14 days. Immunohistochemistry revealed a decline in M1 and M2 macrophage markers over time for both ETT types. Among the cytokines, IL-8 levels differed significantly between the roxadustat and valacyclovir ETT groups, while no other cytokines showed statistically significant differences. Additionally, increased biofilm formation was observed in the coated ETTs with notable alterations in microbiota distinctive to each ETT type and across time.

CONCLUSION

The injured and intubated airway resulted in increased laryngeal stiffness. Local inflammation and the type of therapeutic administered impacted the bacterial composition within the upper respiratory microbiome, which in turn mediated local tissue healing and recovery.

Activation of the hypoxia-inducible factor pathway by roxadustat improves glucose metabolism in human primary myotubes from men

AIMS/HYPOTHESIS

Hypoxia-inducible factor prolyl 4-hydroxylase (HIF-P4H) enzymes regulate adaptive cellular responses to low oxygen concentrations. Inhibition of HIF-P4Hs leads to stabilisation of hypoxia-inducible factors (HIFs) and activation of the HIF pathway affecting multiple biological processes to rescue cells from hypoxia. As evidence from animal models suggests that HIF-P4H inhibitors could be used to treat metabolic disorders associated with insulin resistance, we examined whether roxadustat, an HIF-P4H inhibitor approved for the treatment of renal anaemia, would have an effect on glucose metabolism in primary human myotubes.

METHODS

Primary skeletal muscle cell cultures, established from biopsies of vastus lateralis muscle from men with normal glucose tolerance (NGT) (n=5) or type 2 diabetes (n=8), were treated with roxadustat. Induction of HIF target gene expression was detected with quantitative real-time PCR. Glucose uptake and glycogen synthesis were investigated with radioactive tracers. Glycolysis and mitochondrial respiration rates were measured with a Seahorse analyser.

RESULTS

Exposure to roxadustat stabilised nuclear HIF1α protein expression in human myotubes. Treatment with roxadustat led to induction of HIF target gene mRNAs for GLUT1 (also known as SLC2A1), HK2, MCT4 (also known as SLC16A4) and HIF-P4H-2 (also known as PHD2 or EGLN1) in myotubes from donors with NGT, with a blunted response in myotubes from donors with type 2 diabetes. mRNAs for LDHA, PDK1 and GBE1 were induced to a similar degree in myotubes from donors with NGT or type 2 diabetes. Exposure of myotubes to roxadustat led to a 1.4-fold increase in glycolytic rate in myotubes from men with NGT (p=0.0370) and a 1.7-fold increase in myotubes from donors with type 2 diabetes (p=0.0044), with no difference between the groups (p=0.1391). Exposure to roxadustat led to a reduction in basal mitochondrial respiration in both groups (p<0.01). Basal glucose uptake rates were similar in myotubes from donors with NGT (20.2 ± 2.7 pmol mg-1 min-1) and type 2 diabetes (25.3 ± 4.4 pmol mg-1 min-1, p=0.4205). Treatment with roxadustat enhanced insulin-stimulated glucose uptake in myotubes from donors with NGT (1.4-fold vs insulin-only condition, p=0.0023). The basal rate of glucose incorporation into glycogen was lower in myotubes from donors with NGT (233 ± 12.4 nmol g-1 h-1) than in myotubes from donors with type 2 diabetes (360 ± 40.3 nmol g-1 h-1, p=0.0344). Insulin increased glycogen synthesis by 1.9-fold (p=0.0025) in myotubes from donors with NGT, whereas roxadustat did not affect their basal or insulin-stimulated glycogen synthesis. Insulin increased glycogen synthesis by 1.7-fold (p=0.0031) in myotubes from donors with type 2 diabetes. While basal glycogen synthesis was unaffected by roxadustat, pretreatment with roxadustat enhanced insulin-stimulated glycogen synthesis in myotubes from donors with type 2 diabetes (p=0.0345).

CONCLUSIONS/INTERPRETATION

Roxadustat increases glycolysis and inhibits mitochondrial respiration in primary human myotubes regardless of diabetes status. Roxadustat may also improve insulin action on glycogen synthesis in myotubes from donors with type 2 diabetes.

The significance of ferroptosis in renal diseases and its therapeutic potential

Kidney diseases are significant global public health concern, with increasing prevalence and substantial economic impact. Developing novel therapeutic approaches are essential for delaying disease progression and improving patient quality of life. Cell death signifying the termination of cellular life, could facilitate appropriate bodily development and internal homeostasis. Recently, regulated cell death (RCD) forms such as ferroptosis, characterized by iron-dependent lipid peroxidation, has garnered attention in diverse renal diseases and other pathological conditions. This review offers a comprehensive examination of ferroptosis, encompassing an analysis of the involvement of iron and lipid metabolism, the System Xc - /glutathione/glutathione peroxidase 4 signaling, and additional associated pathways. Meanwhile, the review delves into the potential of targeting ferroptosis as a therapeutic approach in the management of acute kidney injury (AKI), chronic kidney disease (CKD), diabetic nephropathy, and renal tumors. Furthermore, it emphasizes the significance of ferroptosis in the transition from AKI to CKD and further accentuates the potential for repurposing drug and utilizing traditional medicine in targeting ferroptosis-related pathways for clinical applications. The integrated review provides valuable insights into the role of ferroptosis in kidney diseases and highlights the potential for targeting ferroptosis as a therapeutic strategy.

Outcomes and complications of hemodialysis in patients with renal cancer following bilateral nephrectomy

Objectives

The management of patients undergoing bilateral nephrectomy for renal cancer presents significant challenges, particularly in addressing hypotension, anemia, and tumor recurrence during hemodialysis.

Case presentation

A patient diagnosed with renal clear cell carcinoma in 2009 was followed until his demise in June 2022, with detailed documentation of symptoms, signs, laboratory results, diagnosis, and treatment. In the presented case, post-nephrectomy, the patient experienced frequent hypotension and anemia during dialysis, improving with erythropoietin-stimulating agents and subsequently with rosuvastatin. Later, multiple metastases were detected, correlating with normalized blood pressure and hemoglobin.

Literature review

A literature search up to September 2023 was also conducted, gathering data on hypotension, anemia, and tumor recurrence post-nephrectomy. Literature analysis of six cases revealed a 100% tumor recurrence rate in elderly patients (>50 years).

Conclusion

Treatment of anemia in bilateral nephrectomy patients warrants consideration of medication-induced tumor recurrence, highlighting early kidney transplantation to avoid adverse reactions like hypotension.

A preliminary study of roxadustat in the treatment of aplastic anemia patients with inadequate erythroid responses

Some aplastic anemia(AA) patients only have partial hematological responses after immunosuppressive therapy. Failure to achieve complete normalization of blood counts, particularly hemoglobin, will reduce their quality of life. This open-label pilot study was conducted to evaluate the efficacy and safety of roxadustat in this setting. A total of 14 patients with AA who had inadequate erythroid response after immunosuppressive therapy were included in the study. The primary efficacy endpoint was hemoglobin response at week 8 after roxadustat treatment. The median duration of roxadustat therapy was 14 (4-30) weeks, with 12 patients receiving roxadustat for ≥ 8 weeks. At week 8, nine patients (9/14, 64.3%) had their hemoglobin rising for at least 15 g/L, with two patients (2/14, 14.3%) achieving normal hemoglobin levels. By the last follow-up, hemoglobin responses were observed in 10 patients (10/14, 71.4%), with 4 patients(4/14, 28.6%) having normal hemoglobin levels. Roxadustat was tapered or discontinued in four responded patients; one relapsed after 12 weeks of tapering, and three maintained their response. Four patients (4/14, 28.6%) experienced mild adverse effects during therapy. Roxadustat is safe and well tolerated by patients with AA. Treatment with the hypoxia-inducible factor prolyl hydroxylase inhibitor improves hemoglobin levels in AA patients with inadequate erythroid responses.

Roxadustat Attenuates Adverse Remodeling Following Myocardial Infarction in Mice

Activation of the CXCL12/CXCR4/ACKR3 axis is known to aid myocardial repair through ischemia-triggered hypoxia-inducible factor-1α (HIF-1α). To enhance the upregulation of HIF-1α, we administered roxadustat, a novel prolyl hydroxylase inhibitor (PHI) clinically approved by the European Medicines Agency 2021 for the treatment of renal anemia, with the purpose of improving LV function and attenuating ischemic cardiomyopathy.

METHODS

We evaluated roxadustat's impact on HIF-1 stimulation, cardiac remodeling, and function after MI. Therefore, we analyzed nuclear HIF-1 expression, the mRNA and protein expression of key HIF-1 target genes (RT-PCR, Western blot), inflammatory cell infiltration (immunohistochemistry), and apoptosis (TUNEL staining) 7 days after MI. Additionally, we performed echocardiography in male and female C57BL/6 mice 28 days post-MI.

RESULTS

We found a substantial increase in nuclear HIF-1, associated with an upregulation of HIF-1α target genes like CXCL12/CXCR4/ACKR3 at the mRNA and protein levels. Roxadustat increased the proportion of myocardial reparative M2 CD206+ cells, suggesting beneficial alterations in immune cell migration and a trend towards reduced apoptosis. Echocardiography showed that roxadustat treatment significantly preserved ejection fraction and attenuated subsequent ventricular dilatation, thereby reducing adverse remodeling.

CONCLUSIONS

Our findings suggest that roxadustat is a promising clinically approved treatment option to preserve myocardial function by attenuating adverse remodeling.

[Effect of salvia miltiorrhiza combined with roxadustat on wound healing of full-thickness skin defects in diabetic rats and its mechanism]

Objective: To explore the effect of salvia miltiorrhiza combined with roxadustat on wound healing of full-thickness skin defects in diabetic rats and its mechanism. Methods: This study was an experimental study. Twenty male 8-week-old Sprague-Dawley rats were used to successfully establish diabetic model, then full-thickness skin defect wounds on their backs were made. The rats were divided into normal saline group, roxadustat alone group, salvia miltiorrhiza alone group, and roxadustat+salvia miltiorrhiza group according to the random number table, with 5 rats in each group. Immediately after injury, the rats in normal saline group were given 5 mL normal saline by gavage, the rats in roxadustat alone group were given 1.5 mg/mL roxadustat suspension by gavage at 25 mg/kg, the rats in salvia miltiorrhiza alone group were given 18 mg/mL salvia miltiorrhiza suspension by gavage at 300 mg/kg, and the rats in roxadustat+salvia miltiorrhiza group were given 19.5 mg/mL roxadustat and salvia miltiorrhiza suspension at roxadustat 25 mg/kg and salvia miltiorrhiza 300 mg/kg. All were administered once a day for 2 weeks. The wounds at 0 (immediately), 4, 8, and 12 d after injury were observed, and the wound healing rates at 4, 8, and 12 d after injury were calculated (n=5). At 14 d after injury, abdominal aortic blood was collected, and hemoglobin, red cell count, and white blood cell count were detected (n=5). The wound tissue was collected for hematoxylin-eosin staining to observe inflammatory infiltration, skin tissue structure, and neovascularization, for Masson staining to observe the proportion of collagen fiber (n=3), for Western blotting to detect the protein expression levels of vascular endothelial growth factor (VEGF), CD31, interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), and IL-1β (n=3), and for immunohistochemical staining to determine the protein expression levels of epidermal growth factor receptor (EGFR), hypoxia-inducible factor 1α (HIF-1α), and proliferating cell nuclear antigen (PCNA), with sample number of 3. Results: From 0 to 12 d after injury, the wound areas of rats in 4 groups were gradually decreased. At 4 d after injury, the wound healing rates of rats in salvia miltiorrhiza alone group and roxadustat+salvia miltiorrhiza group were significantly higher than those in normal saline group and roxadustat alone group (P<0.05). At 8 d after injury, the wound healing rates of rats in roxadustat alone group and salvia miltiorrhiza alone group were significantly higher than the rate in normal saline group (P<0.05), and the wound healing rate of rats in roxadustat+salvia miltiorrhiza group was significantly higher than the rates in the other 3 groups (with P values all <0.05). At 12 d after injury, the wound healing rates of rats in roxadustat alone group, salvia miltiorrhiza alone group, and roxadustat+salvia miltiorrhiza group were significantly higher than the rate in normal saline group (P<0.05). At 14 d after injury, there were no statistically significant differences in the hemoglobin or red blood cell count of rats in 4 groups (P<0.05). The white blood cell count of rats in roxadustat alone group, salvia miltiorrhiza alone group, and roxadustat+salvia miltiorrhiza group were respectively (24.3±1.2)×109/L, (26.3±2.4)×109/L, and (15.0±0.7)×109/L, which were significantly lower than (33.8±2.7)×109/L in normal saline group (P<0.05); the white blood cell count of rats in roxadustat+salvia miltiorrhiza group was significantly lower than that in roxadustat alone group and salvia miltiorrhiza alone group (with P values both <0.05). At 14 d after injury, a large number of inflammatory cell infiltration, disordered skin tissue structure, and few new blood vessels were observed in the wounds of rats in normal saline group; while a small amount of inflammatory cell infiltration, tight skin tissue structure, and rich neovascularization were observed in the wounds of rats in the other 3 groups. There were no statistically significant differences in the proportion of collagen fiber of wounds in rats among the 4 groups (P>0.05). At 14 d after injury, the protein expression levels of VEGF and CD31 in the wound tissue of rats in roxadustat alone group, salvia miltiorrhiza alone group, and roxadustat+salvia miltiorrhiza group were significantly higher than those in normal saline group (P<0.05), the protein expression level of CD31 in the wound tissue of rats in roxadustat+salvia miltiorrhiza group was significantly higher than the levels in roxadustat alone group and salvia miltiorrhiza alone group (with P values both <0.05). At 14 d after injury, the protein expression levels of IL-6, TNF-α, and IL-1β in the wound tissue of rats in roxadustat alone group, salvia miltiorrhiza alone group, and roxadustat+salvia miltiorrhiza group were significantly lower than those in normal saline group (P<0.05); the protein expression levels of IL-6 and IL-1β in the wound tissue of rats in roxadustat+salvia miltiorrhiza group were significantly lower than those in roxadustat alone group and salvia miltiorrhiza alone group (P<0.05); the protein expression level of TNF-α in the wound tissue of rats in roxadustat+salvia miltiorrhiza group was significantly lower than that in salvia miltiorrhiza alone group (P<0.05). At 14 d after injury, the protein expression level of EGFR in the wound tissue of rats in roxadustat+salvia miltiorrhiza group was significantly higher than the levels in the other 3 groups (with P values all <0.05); the protein expression levels of HIF-1α in the wound tissue of rats in roxadustat alone group and roxadustat+salvia miltiorrhiza group were significantly higher than the level in normal saline group (P<0.05), and the protein expression level of HIF-1α in the wound tissue of rats in roxadustat+salvia miltiorrhiza group was significantly higher than that in salvia miltiorrhiza alone group (P<0.05); there were no statistically significant differences in the protein expression level of PCNA in the wound tissue of rats in 4 groups (P>0.05). Conclusions: Roxadustat combined with salvia miltiorrhiza can promote the wound healing of full-thickness skin defects in diabetic rats by promoting blood vessel regeneration and reducing inflammatory response.

Isoquinoline-based intrinsic fluorescence assessment of erythropoiesis-stimulating agent, Roxadustat (FG-4592), in tablets: applications to content uniformity and human plasma evaluation

In the present study, a first validated and green spectrofluorimetric approach for its assessment and evaluation in different matrices was investigated. After using an excitation wavelength of 345 nm, Roxadustat (ROX) demonstrates a highly native fluorescence at an emission of 410 nm. The influences of experimental factors such as pH, diluting solvents, and different organized media were tested, and the most appropriate solvent choice was ethanol. It was confirmed that there was a linear relationship between the concentration of ROX and the relative fluorescence intensity in the range 60.0-1000.0 ng ml-1, with the limit of detection and limit of quantitation, respectively, being 17.0 and 53.0 ng ml-1. The mean recoveries % [±standard deviation (SD), n = 5] for pharmaceutical preparations were 100.11% ± 2.24%, whereas for plasma samples, they were 100.08 ± 1.08% (±SD, n = 5). The results obtained after the application of four greenness criteria, Analytical Eco-Scale metric, NEMI, GAPI, and AGREE metric, confirmed its eco-friendliness. In addition, the whiteness meter (RGB12) confirmed its level of sustainability. The International Council for Harmonisation (ICH) criteria were used to verify the developed method through the study in both spiked plasma samples and content uniformity evaluation. An appropriate standard for various applications in industry and quality control laboratories was developed.

A clinical study on roxadustat for anemia in diabetic nephropathy: a 8-week study

PURPOSE

The development of roxadustat is a standard treatment for renal anemia, and multiple clinical trials have proved its safety and efficacy. However, less information is available from trials of the population with diabetic nephropathy (DN). This study aimed to determine whether roxadustat is effective for treating DN.

METHODS

This was a single-center, retrospective, institutional review board-approved cohort study. The patients with DN were chosen and given roxadustat or erythropoietin (EPO) for 8 weeks. The mean hemoglobin (Hb) level after 8 weeks of treatment served as the primary outcome. Alterations in the iron index and lipid levels were considered secondary objectives. Sub-group analysis was performed to observe the impact of inflammation and glycemic status on Hb.

RESULTS

A total of 80 patients were enrolled, 40 in each group. After 8 weeks of treatment, the Hb levels in the roxadustat group were higher than those in the control group. The number of patients who achieved Hb response was higher in the roxadustat group than in the control group (77.5% versus 27.5%; P < 0.001). In addition to lowering total cholesterol and low-density lipoprotein cholesterol, roxadustat decreased ferritin and elevated total iron-binding capacity. Compared to the control group, roxadustat was more beneficial for patients with an inflammatory condition and poor glycemic control.

CONCLUSIONS

Roxadustat treatment remarkably corrected anemia in patients with DN, and its effectiveness was unaffected by inflammation or glycemic control levels. In addition, roxadustat can also reduce a patient's blood lipid level and enhance the body's use of iron.

CLINICAL TRIAL REGISTRATION

ChiCTR2200057232.

Zinc Supplementation Enhances the Hematopoietic Activity of Erythropoiesis-Stimulating Agents but Not Hypoxia-Inducible Factor-Prolyl Hydroxylase Inhibitors

Since zinc is involved in many aspects of the hematopoietic process, zinc supplementation can reduce erythropoiesis-stimulating agents (ESAs) in patients undergoing hemodialysis. However, it remains unclear whether hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHIs) have similar reduction effects. HIF-PHI stabilizes HIF, which promotes hematopoiesis, although HIF-1α levels are downregulated by zinc. This study aimed to investigate the effect of zinc supplementation on the hematopoietic effect of HIF-PHI in patients undergoing hemodialysis. Thirty patients undergoing maintenance hemodialysis who underwent periods of treatment with roxadustat or darbepoetin alfa during the past 3 years were retrospectively observed. Participants who underwent periods with and without zinc supplementation were selected, with nine treated with darbepoetin alfa and nine treated with roxadustat. Similarly to the ESA responsiveness index (ERI), the hematopoietic effect of zinc supplementation was determined by the HIF-PHI responsiveness index (HRI), which was calculated by dividing the HIF-PHI dose (mg/week) by the patient's dry weight (kg) and hemoglobin level (g/L). Zinc supplementation significantly increased ERI (p < 0.05), but no significant change was observed (p = 0.931) in HRI. Although zinc supplementation did not significantly affect HRI, adequate zinc supplementation is required to alleviate concerns such as vascular calcification and increased serum copper during the use of HIF-PHI.

Pharmacological HIF-1 activation upregulates extracellular vesicle production synergistically with adiponectin through transcriptional induction and protein stabilization of T-cadherin

Pharmacological activation of hypoxia-inducible factor 1 (HIF-1), a hypoxia-responsive transcription factor, has attracted increasing attention due to its efficacy not only in renal anemia but also in various disease models. Our study demonstrated that a HIF-1 activator enhanced extracellular vesicle (EV) production from cultured endothelial cells synergistically with adiponectin, an adipocyte-derived factor, through both transcriptional induction and posttranscriptional stabilization of an adiponectin binding partner, T-cadherin. Increased EV levels were observed in wild-type mice but not in T-cadherin null mice after consecutive administration of roxadustat. Adiponectin- and T-cadherin-dependent increased EV production may be involved in the pleiotropic effects of HIF-1 activators.

Effect of Roxadustat on Thyroid Function in Patients With Renal Anemia

CONTEXT

Roxadustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor, a recently developed class of drugs for treatment of anemia in chronic kidney disease (CKD), is reported to have a structure unlike that of other HIF-PH inhibitors but similar to that of triiodothyronine and bind to the thyroid hormone receptor in vitro. However, reports on the effects of roxadustat on thyroid function are limited and not detailed, and it remains unknown whether other HIF-PH inhibitors also affect thyroid function.

OBJECTIVE

To compare the effect of roxadustat with daprodustat, another HIF-PH inhibitor, on thyroid function in patients with renal anemia in CKD.

METHODS

This retrospective observational study included a total of 26 patients with anemia in CKD who were treated with roxadustat or daprodustat; thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were measured before and after treatment with the drugs.

RESULTS

After initiation of roxadustat, TSH showed a significant decrease (2.4732 [1.7858-4.9016] μIU/mL before treatment and 0.659 [0.112-2.005] μIU/mL after treatment, P < .05); FT4 showed a significant decrease (0.93 [0.84-1.05] ng/dL before treatment and 0.70 [0.53-0.85] ng/dL after treatment, P < .01). After daprodustat initiation, neither TSH nor FT4 showed a significant change (TSH: 3.044 [1.853-4.171] μIU/mL before treatment and 2.893 [1.866-4.894] μIU/mL after treatment, P = .635; FT4 was 0.93 [0.81-1.00] ng/dL before treatment and 0.97 [0.87-1.05] ng/dL after treatment, P = .328).

CONCLUSION

Roxadustat decreases TSH and FT4 levels while daprodustat does not.

Targeting hypoxia-inducible factor-1 alpha suppresses Helicobacter pylori-induced gastric injury via attenuation of both cag-mediated microbial virulence and proinflammatory host responses

Helicobacter pylori-induced inflammation is the strongest known risk factor for gastric adenocarcinoma. Hypoxia-inducible factor-1 (HIF-1α) is a key transcriptional regulator of immunity and carcinogenesis. To examine the role of this mediator within the context of H. pylori-induced injury, we first demonstrated that HIF-1α levels were significantly increased in parallel with the severity of gastric lesions in humans. In interventional studies targeting HIF-1α, H. pylori-infected mice were treated ± dimethyloxalylglycine (DMOG), a prolyl hydroxylase inhibitor that stabilizes HIF-1α. H. pylori significantly increased proinflammatory chemokines/cytokines and inflammation in vehicle-treated mice; however, this was significantly attenuated in DMOG-treated mice. DMOG treatment also significantly decreased function of the H. pylori type IV secretion system (T4SS) in vivo and significantly reduced T4SS-mediated NF-κB activation and IL-8 induction in vitro. These results suggest that prolyl hydroxylase inhibition protects against H. pylori-mediated pathologic responses, and is mediated, in part, via attenuation of H. pylori cag-mediated virulence and suppression of host proinflammatory responses.

Hypoxia-induced signaling in the cardiovascular system: pathogenesis and therapeutic targets

Hypoxia, characterized by reduced oxygen concentration, is a significant stressor that affects the survival of aerobic species and plays a prominent role in cardiovascular diseases. From the research history and milestone events related to hypoxia in cardiovascular development and diseases, The "hypoxia-inducible factors (HIFs) switch" can be observed from both temporal and spatial perspectives, encompassing the occurrence and progression of hypoxia (gradual decline in oxygen concentration), the acute and chronic manifestations of hypoxia, and the geographical characteristics of hypoxia (natural selection at high altitudes). Furthermore, hypoxia signaling pathways are associated with natural rhythms, such as diurnal and hibernation processes. In addition to innate factors and natural selection, it has been found that epigenetics, as a postnatal factor, profoundly influences the hypoxic response and progression within the cardiovascular system. Within this intricate process, interactions between different tissues and organs within the cardiovascular system and other systems in the context of hypoxia signaling pathways have been established. Thus, it is the time to summarize and to construct a multi-level regulatory framework of hypoxia signaling and mechanisms in cardiovascular diseases for developing more therapeutic targets and make reasonable advancements in clinical research, including FDA-approved drugs and ongoing clinical trials, to guide future clinical practice in the field of hypoxia signaling in cardiovascular diseases.

The Intriguing Role of Hypoxia-Inducible Factor in Myocardial Ischemia and Reperfusion: A Comprehensive Review

Hypoxia-inducible factors (HIFs) play a crucial role in cellular responses to low oxygen levels during myocardial ischemia and reperfusion injury. HIF stabilizers, originally developed for treating renal anemia, may offer cardiac protection in this context. This narrative review examines the molecular mechanisms governing HIF activation and function, as well as the pathways involved in cell protection. Furthermore, we analyze the distinct cellular roles of HIFs in myocardial ischemia and reperfusion. We also explore potential therapies targeting HIFs, emphasizing their possible benefits and limitations. Finally, we discuss the challenges and opportunities in this research area, underscoring the need for continued investigation to fully realize the therapeutic potential of HIF modulation in managing this complex condition.

Relationship Between the Effect of Roxadustat and Comorbid Diabetes in Non-dialyzed Chronic Kidney Disease Patients: A Retrospective Observational Study

Introduction The dose of roxadustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor, required to treat anemia, the hemoglobin level and the rate of hemoglobin target achievement were retrospectively investigated in non-dialyzed chronic kidney disease (CKD) patients with and without type 2 diabetes. Methods As the full analysis set, 25 subjects (10 with diabetes and 15 without diabetes) were observed over six months among 44 non-dialyzed CKD patients who received roxadustat. The target hemoglobin level was set at 110-130 g/L. Results The comorbidities of diabetes and body weight at baseline were significantly associated with each dose of roxadustat at six months and the change in each dose of roxadustat from the initiation of roxadustat treatment. There was no significant difference in the amount of increase in the hemoglobin level (14±11 g/L vs. 15±8 g/L) and the rate of hemoglobin target achievement (70% vs. 67%) between patients with and without diabetes. Each dose of roxadustat gradually decreased in patients without diabetes, whereas it increased in those with diabetes. Each dose of roxadustat was significantly higher in patients with diabetes than in those without diabetes at 3 (60±21 mg vs. 42±14 mg) and 6 (61±22 mg vs. 41±14 mg) months after the initiation of roxadustat treatment. Conclusion Roxadustat is useful for the treatment of anemia in both CKD patients with and without diabetes. However, the dose required to achieve the target hemoglobin level may be higher in patients with diabetes than in those without diabetes.

Roxadustat (FG-4592) abated lipopolysaccharides-induced depressive-like symptoms via PI3K signaling

Background

Despite its role in inflammation and the redox system under hypoxia, the effects and molecular mechanisms of hypoxia-inducible factor (HIF) in neuroinflammation-associated depression are poorly explored. Furthermore, Prolyl hydroxylase domain-containing proteins (PHDs) regulate HIF-1; however, whether and how PHDs regulate depressive-like behaviors under Lipopolysaccharides (LPS)-induced stress conditions remain covered.

Methods

To highlight the roles and underlying mechanisms of PHDs-HIF-1 in depression, we employed behavioral, pharmacological, and biochemical analyses using the LPS-induced depression model.

Results

Lipopolysaccharides treatment induced depressive-like behaviors, as we found, increased immobility and decreased sucrose preference in the mice. Concurrently, we examined increased cytokine levels, HIF-1 expression, mRNA levels of PHD1/PHD2, and neuroinflammation upon LPS administration, which Roxadustat reduced. Furthermore, the PI3K inhibitor wortmannin reversed Roxadustat-induced changes. Additionally, Roxadustat treatment attenuated LPS-induced synaptic impairment and improved spine numbers, ameliorated by wortmannin.

Conclusion

Lipopolysaccharides-dysregulates HIF-PHDs signaling may contribute to neuroinflammation-coincides depression via PI3K signaling.

Roxadustat, a HIF-PHD inhibitor with exploitable potential on diabetes-related complications

Diabetes mellitus (DM) is a group of metabolic diseases caused by absolute or relative deficiency of insulin secretion and characterized by chronic hyperglycemia. Its complications affect almost every tissue of the body, usually leading to blindness, renal failure, amputation, etc. and in the final stage, it mostly develops into cardiac failure, which is the main reason why diabetes mellitus manifests itself as a high clinical lethality. The pathogenesis of diabetes mellitus and its complications involves various pathological processes including excessive production of mitochondrial reactive oxygen species (ROS) and metabolic imbalance. Hypoxia-inducible Factor (HIF) signaling pathway plays an important role in both of the above processes. Roxadustat is an activator of Hypoxia-inducible Factor-1α, which increases the transcriptional activity of Hypoxia-inducible Factor-1α by inhibiting hypoxia-inducible factor prolyl hydroxylase (HIF-PHD). Roxadustat showed regulatory effects on maintaining metabolic stability in the hypoxic state of the body by activating many downstream signaling pathways such as vascular endothelial growth factor (VEGF), glucose transporter protein-1 (GLUT1), lactate dehydrogenase (LDHA), etc. This review summarizes the current research findings of roxadustat on the diseases of cardiomyopathy, nephropathy, retinal damage and impaired wound healing, which also occur at different stages of diabetes and greatly contribute to the damage caused by diabetes to the organism. We attempts to uncover a more comprehensive picture of the therapeutic effects of roxadustat, and inform its expanding research about diabetic complications treatment.

Open-label, Phase 2 study of roxadustat for the treatment of anemia in patients receiving chemotherapy for non-myeloid malignancies

Anemia is a common side effect of myelosuppressive chemotherapy; however, chemotherapy-induced anemia (CIA) management options are suboptimal. We evaluated the efficacy and safety of roxadustat in this setting. This open-label Phase 2 study included patients with non-myeloid malignancies and CIA (hemoglobin [Hb] ≤10 g/dL) who had planned concurrent myelosuppressive chemotherapy for ≥8 additional weeks. Oral roxadustat was administered for ≤16 weeks (starting dose 2.0 or 2.5 mg/kg, then titrated every 4 weeks). The primary efficacy endpoint was mean maximum change in Hb within 16 weeks of baseline without red blood cell (RBC) transfusion. Patients were assigned to roxadustat 2.0 (n = 31) or 2.5 mg/kg (n = 61) starting doses, and 89 were assessed for efficacy. The mean (standard deviation) maximum Hb change from baseline without RBC transfusion was 2.4 (1.5) and 2.5 (1.5) g/dL in the roxadustat 2.0 and 2.5 mg/kg groups, respectively. Median (range) time to Hb increase of ≥2 g/dL was 71 (57-92) days. Twelve patients (14.5%) had RBC transfusions (Week 5 to the end of treatment). Roxadustat was efficacious regardless of tumor type and chemotherapy regimen. Deep vein thrombosis (DVT) and pulmonary embolism (PE) occurred in 14 (15.2%) and nine (9.8%) patients, respectively, and three had serious adverse events attributed to roxadustat in the opinion of the investigators (PE: n = 2 [2.2%]; DVT: n = 1 [1.1%]). Roxadustat increased Hb in patients with CIA regardless of tumor type and chemotherapy regimen. Adverse events were consistent with observations in patients with advanced-stage malignancies.