RNA sequencing reveals the potential mechanism of exercise preconditioning for cerebral ischemia reperfusion injury in rats.

INTRODUCTION: Cerebral ischemia reperfusion injury (CIRI) often leads to deleterious complications after stroke patients receive reperfusion therapy. Exercise preconditioning (EP) has been reported to facilitate brain function recovery. We aim to explore the specific mechanism of EP in CIRI. METHODS: Sprague-Dawley rats were randomized into Sham, middle cerebral artery occlusion (MCAO), and EP groups (n = 11). The rats in the EP group received adaptive training for 3 days (10 m/min, 20 min/day, with a 0° incline) and formal training for 3 weeks (6 days/week, 25 m/min, 30 min/day, with a 0° incline). Then, rats underwent MCAO surgery to establish CIRI models. After 48 h, neurological deficits and cerebral infarction of the rats were measured. Neuronal death and apoptosis in the cerebral cortices were detected. Furthermore, RNA sequencing was conducted to investigate the specific mechanism of EP on CIRI, and qPCR and Western blotting were further applied to confirm RNA sequencing results. RESULTS: EP improved neurological deficit scores and reduced cerebral infarction in MCAO rats. Additionally, pre-ischemic exercise also alleviated neuronal death and apoptosis of the cerebral cortices in MCAO rats. Importantly, 17 differentially expressed genes (DEGs) were identified through RNA sequencing, and these DEGs were mainly enriched in the HIF-1 pathway, cellular senescence, proteoglycans in cancer, and so on. qPCR and Western blotting further confirmed that EP could suppress TIMP1, SOCS3, ANGPTL4, CDO1, and SERPINE1 expressions in MCAO rats. CONCLUSION: EP can improve CIRI in vivo, the mechanism may relate to TIMP1 expression and HIF-1 pathway, which provided novel targets for CIRI treatment.

Hypoxia in uterine fibroids: role in pathobiology and therapeutic opportunities.

Uterine fibroids are the most common tumors in females affecting up to 70% of women world-wide, yet targeted therapeutic options are limited. Oxidative stress has recently surfaced as a key driver of fibroid pathogenesis and provides insights into hypoxia-induced cell transformation, extracellular matrix pathophysiology, hypoxic cell signaling cascades, and uterine biology. Hypoxia drives fibroid tumorigenesis through (1) promoting myometrial stem cell proliferation, (2) causing DNA damage propelling transformation of stem cells to tumor initiating cells, and (3) driving excess extracellular matrix (ECM) production. Common fibroid-associated DNA mutations include MED12 mutations, HMGA2 overexpression, and Fumarate hydratase loss of function. Evidence suggests an interaction between hypoxia signaling and these mutations. Fibroid development and growth are promoted by hypoxia-triggered cell signaling via various pathways including HIF-1, TGFß, and Wnt/ß-catenin. Fibroid-associated hypoxia persists due to antioxidant imbalance, ECM accumulation, and growth beyond adequate vascular supply. Current clinically available fibroid treatments do not take advantage of hypoxia-targeting therapies. Growing pre-clinical and clinical studies identify ROS inhibitors, anti-HIF-1 agents, Wnt/ß-catenin inhibition, and TGFß cascade inhibitors as agents that may reduce fibroid development and growth through targeting hypoxia.

A hypoxia-derived gene signature to suggest cisplatin-based therapeutic responses in patients with cervical cancer.

Cervical cancer remains a significant global public health concern, often exhibits cisplatin resistance in clinical settings. Hypoxia, a characteristic of cervical cancer, substantially contributes to cisplatin resistance. To evaluate the therapeutic efficacy of cisplatin in patients with cervical cancer and to identify potential effective drugs against cisplatin resistance, we established a hypoxia-inducible factor-1 (HIF-1)-related risk score (HRRS) model using clinical data from patients treated with cisplatin. Cox and LASSO regression analyses were used to stratify patient risks and prognosis. Through qRT-PCR, we validated nine potential prognostic HIF-1 genes that successfully predict cisplatin responsiveness in patients and cell lines. Subsequently, we identified fostamatinib, an FDA-approved spleen tyrosine kinase inhibitor, as a promising drug for targeting the HRRS-high group. We observed a positive correlation between the IC50 values of fostamatinib and HRRS in cervical cancer cell lines. Moreover, fostamatinib exhibited potent anticancer effects on high HRRS groups in vitro and in vivo. In summary, we developed a hypoxia-related gene signature that suggests cisplatin response prediction in cervical cancer and identified fostamatinib as a potential novel treatment approach for resistant cases.

Heyingwuzi formulation alleviates diabetic retinopathy by promoting mitophagy via the HIF-1α/BNIP3/NIX axis.

BACKGROUND: Diabetic retinopathy (DR) is the primary cause of visual problems in patients with diabetes. The Heyingwuzi formulation (HYWZF) is effective against DR. AIM: To determine the HYWZF prevention mechanisms, especially those underlying mitophagy. METHODS: Human retinal capillary endothelial cells (HRCECs) were treated with high glucose (hg), HYWZF serum, PX-478, or Mdivi-1 in vitro. Then, cell counting kit-8, transwell, and tube formation assays were used to evaluate HRCEC proliferation, invasion, and tube formation, respectively. Transmission electron microscopy was used to assess mitochondrial morphology, and Western blotting was used to determine the protein levels. Flow cytometry was used to assess cell apoptosis, reactive oxygen species (ROS) production, and mitochondrial membrane potential. Moreover, C57BL/6 mice were established in vivo using streptozotocin and treated with HYWZF for four weeks. Blood glucose levels and body weight were monitored continuously. Changes in retinal characteristics were evaluated using hematoxylin and eosin, tar violet, and periodic acid-Schiff staining. Protein levels in retinal tissues were determined via Western blotting, immunohistochemistry, and immunostaining. RESULTS: HYWZF inhibited excessive ROS production, apoptosis, tube formation, and invasion in hg-induced HRCECs via mitochondrial autophagy in vitro. It increased the mRNA expression levels of BCL2-interacting protein 3 (BNIP3), FUN14 domain-containing 1, BNIP3-like (BNIP3L, also known as NIX), PARKIN, PTEN-induced kinase 1, and hypoxia-inducible factor (HIF)-1α. Moreover, it downregulated the protein levels of vascular endothelial cell growth factor and increased the light chain 3-II/I ratio. However, PX-478 and Mdivi-1 reversed these effects. Additionally, PX-478 and Mdivi-1 rescued the effects of HYWZF by decreasing oxidative stress and apoptosis and increasing mitophagy. HYWZF intervention improved the symptoms of diabetes, tissue damage, number of acellular capillaries, and oxidative stress in vivo. Furthermore, in vivo experiments confirmed the results of in vitro experiments. CONCLUSION: HYWZF alleviated DR and associated damage by promoting mitophagy via the HIF-1α/BNIP3/NIX axis.

Cannabidiol ameliorates lipopolysaccharide-induced cardiovascular toxicity by its antioxidant and anti-inflammatory activity via regulating IL-6, Hif1α, STAT3, eNOS pathway.

BACKGROUND: Systemic inflammation causes several organ damage by activating the intracellular signaling mechanisms. Heart and aorta tissues are the structures mostly affected by this situation. By examining underlying processes, this study sought to determine whether cannabidiol (CBD) may have protective effects against the cardiovascular damage brought on by lipopolysaccharide (LPS). MATERIALS AND METHODS: A total of 32 female rats were randomly allocated to one of four groups: control, lipopolysaccharide (LPS) (5 mg/kg, i.p., single dose), LPS + CBD (5 mg/kg, i.p., single dose), and CBD groups. The rats were killed six hours after receiving LPS, and tissues from the heart and aorta were taken. Histopathological and immunohistochemical analyzes were performed. Oxidative stress was evaluated biochemically by spectrophotometric method. Expression levels of genes were studied by RT-qPCR method. RESULTS: Histopathological analysis of the LPS group showed moderate hyperemia, hemorrhages, edema, inflammation, and myocardial cell damage. There was a slight to moderate increase in Cox-1, G-CSF, and IL-3 immunoexpressions, along with enhanced expressions of IL-6, Hif1α, and STAT3 genes, and decreased expressions of eNOS genes. Additionally, there were increased levels of TOS and decreased TAS levels observed biochemically. CBD treatment effectively reversed and improved all of these observed changes. CONCLUSIONS: CBD protects the heart and aorta against systemic inflammation through its antioxidant and anti-inflammatory activity via regulating IL-6, Hif1α, STAT3, and eNOS intracellular pathways.

Harnessing adrenergic blockade in stress-promoted TNBC in vitro and solid tumor in vivo: disrupting HIF-1α and GSK-3ß/ß-catenin driven resistance to doxorubicin.

Sympathetic activation triggered by chronic stress afflicting cancer survivors is an emerging modulator of tumorigenesis. Adrenergic blockade was previously associated with improving response to doxorubicin (DOX) in triple-negative breast cancer (TNBC), yet the precise underlying mechanisms remain obscure. The resilience of cancer stem cells (CSCs) during chemotherapy fosters resistance and relapse. Hypoxia-inducible factor-1α (HIF-1α) and ß-catenin are intertwined transcriptional factors that enrich CSCs and evidence suggests that their expression could be modulated by systemic adrenergic signals. Herein, we aimed to explore the impact of adrenoreceptor blockade using carvedilol (CAR) on DOX and its potential to modulate CSCs overcoming chemoresistance. To achieve this aim, in vitro studies were conducted using adrenaline-preincubated MDA-MB-231 cells and in vivo studies using a chronic restraint stress-promoted solid tumor mouse model. Results revealed that adrenaline increased TNBC proliferation and induced a phenotypic switch reminiscent of CSCs, as evidenced by enhanced mammosphere formation. These results paralleled an increase in aldehyde dehydrogenase-1 (ALDH-1) and Nanog expression levels as well as HIF-1α and ß-catenin upsurge. In vivo, larger tumor volumes were observed in mice under chronic stress compared to their unstressed counterparts. Adrenergic blockade using CAR, however, enhanced the impact DOX had on halting TNBC cell proliferation and tumor growth via enhanced apoptosis. CAR also curbed HIF-1α and ß-catenin tumor levels subsequently suppressing ALDH-1 and SOX2. Our study unveils a central role for HIF-1α linking stress-induced sympathetic activation fueling CSC enrichment via the ß-catenin pathway. It also highlights novel insights into CAR's capacity in reversing DOX chemoresistance in TNBC.

Relaxin combined with transarterial chemoembolization achieved synergistic effects and inhibited liver cancer metastasis in a rabbit VX2 model.

OBJECTIVE: To explore the effect and mechanism of relaxin (RLX) in the growth and metastasis of livercancer after combination treatment with transarterial chemoembolization (TACE). MATERIALS AND METHODS: HCCLM3 and Huh-7 cells were adopted to evaluate the effect of tumor proliferation, migration, and invasion after RLX administration in vitro. The rabbit VX2 model was used to evaluate the biosafety, doxorubicin penetration, local tumor response, tumor metastasis, and survival benefit of RLX combined with TACE treatment. RESULTS: RLX did not affect the proliferation, migration, or invasion of HCCLM3 and Huh-7 cells, and the expression of E-cadherin and HIF-1α also remained unchanged while the MMP-9 protein was upregulated in vitro. In the rabbit VX2 model, compared to the normal saline group (NS), RLX group (RLX) and TACE mono-therapy group (TACE), the group that received TACE combined with RLX (TACE + RLX) showed an improved local tumor response and survival benefit. Furthermore, TACE combined with RLX was found to reduce tumor metastasis. This combination therapy reduced the fibrotic extracellular matrix in the tumor microenvironment, allowing for better penetration of doxorubicin, improved infiltration of CD8+ T cells and affected the secretion of cytokines. Additionally, RLX combined with TACE was able to decrease the expression of HIF-1α and PD-L1. The biosafety of TACE combined with RLX was also confirmed. CONCLUSION: RLX synergized with TACE by mitigating the fibrotic extracellular matrix and tumor hypoxic microenvironment, improving the therapeutic effect and inhibiting metastasis during the treatment of liver cancer.

H2O2 promotes photodynamic efficacy of TMPyP4 against ovarian cancer in vitro by downregulating HIF-1α expression.

Photodynamic therapy (PDT), employing photosensitizers to induce formation of reactive oxygen species (ROS) for tumor elimination, is emerging as a promising treatment modality in oncology due to its unique benefits. However, the PDT application in ovarian cancer, the most prevalent and lethal type of gynecological malignancy with a severe hypoxic microenvironment, remains unknown. This study revealed that photosensitizer TMPyP4 exhibited enhanced efficacy under H2O2 stimulation, with minimal change in cytotoxicity compared to TMPyP4 alone. The results showed that H2O2 increased ROS production induced by TMPyP4, leading to exacerbated mitochondrial dysfunction and DNA damage, ultimately inhibiting proliferation and inducing apoptosis in ovarian cancer cells. Mechanistically, H2O2 primarily enhanced the therapeutic efficacy of PDT with TMPyP4 against ovarian cancer cells by degrading HIF-1α, which subsequently modulated the HIF-1 signaling pathway, thereby alleviating the hypoxic environment in ovarian cancer cells. Our findings underscore the therapeutic potential of targeting HIF-1α within the hypoxic microenvironment for PDT in ovarian cancer and propose a novel integrated strategy for PDT treatment of this malignancy in vitro.

B7-H3 enhances colorectal cancer progression by regulating HB-EGF via HIF-1α.

Background: B7-H3 (or CD276) represents an important costimulatory molecule expressed in many malignant solid tumors, including colorectal cancer (CRC). The receptor of B7-H3 is not known, and the intracellular function of B7-H3 remains obscure. Herein, we report that B7-H3 upregulated the epidermal growth factor heparin-binding epidermal growth factor (HB-EGF), likely by regulating hypoxia-inducible factor 1α (HIF-1α) and thereby promoting the progression of CRC. Methods: Lentiviral transfection was performed on CRC cells to establish stable low-B7-H3 expression cells. A mechanistic analysis with an Agilent human gene expression profiling chip was conducted on them. Clinical data and specimens were collected to detect the connection between B7-H3 and HB-EGF in CRC. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to detect the messenger RNA (mRNA) level of B7-H3, HB-EGF, and HIF-1α. Chromatin immunoprecipitation (ChIP) quantitative real-time PCR was conducted. The protein level of HIF-1α and the phosphatidylinositide 3-kinases (PI3K)-protein kinase B (AKT) pathway were detected by western blot. HIF-1α was recovered by lentiviral transfection, and the HB-EGF mRNA levels, proliferation, invasion, and angiogenesis ability were detected. Results: B7-H3 promoted tumor progression through HB-EGF and the PI3K-AKT pathway. As B7-H3 was downregulated, HB-EGF levels were significantly reduced simultaneously, a growth trend that was shown by both CRC cell lines and cancer tissues. In addition, B7-H3 and HB-EGF had significant associations with tumor-node-metastasis (TNM) stage and lymph node metastasis in 50 CRC patients. The binding ability of HIF-1α to the HB-EGF promoter region was significantly decreased in the shB7-H3 RKO group. Western blot revealed that PI3K, AKT, and mammalian target of rapamycin (mTOR) protein amounts and p-AKT and p-mTOR phosphorylation were also downregulated in shB7-H3 RKO cells, suggesting that B7-H3 may regulate HIF-1α via PI3K-AKT signaling. After recovery of the HIF-1α level by lentiviral transfection, the HB-EGF mRNA levels, proliferation, invasion, and angiogenesis in CRC cells recovered as well. Conclusions: B7-H3 may transmit intracellular signals through PI3K-AKT-mTOR-HIF-1α signaling, upregulating HB-EGF. As the final transcription factor of the pathway, HIF-1α regulates the transcription of the HB-EGF gene, thereby promoting HB-EGF expression, which eventually mediates cell proliferation, invasion, and angiogenesis and promotes the progression of CRC.

The pulmonary effects of nickel-containing nanoparticles: Cytotoxicity, genotoxicity, carcinogenicity, and their underlying mechanisms.

With the exponential growth of the nanotechnology field, the global nanotechnology market is on an upward track with fast-growing jobs. Nickel (Ni)-containing nanoparticles (NPs), an important class of transition metal nanoparticles, have been extensively used in industrial and biomedical fields due to their unique nanostructural, physical, and chemical properties. Millions of people have been/are going to be exposed to Ni-containing NPs in occupational and non-occupational settings. Therefore, there are increasing concerns over the hazardous effects of Ni-containing NPs on health and the environment. The respiratory tract is a major portal of entry for Ni-containing NPs; thus, the adverse effects of Ni-containing NPs on the respiratory system, especially the lungs, have been a focus of scientific study. This review summarized previous studies, published before December 1, 2023, on cytotoxic, genotoxic, and carcinogenic effects of Ni-containing NPs on humans, lung cells in vitro, and rodent lungs in vivo, and the potential underlying mechanisms were also included. In addition, whether these adverse effects were induced by NPs themselves or Ni ions released from the NPs was also discussed. The extra-pulmonary effects of Ni-containing NPs were briefly mentioned. This review will provide us with a comprehensive view of the pulmonary effects of Ni-containing NPs and their underlying mechanisms, which will shed light on our future studies, including the urgency and necessity to produce engineering Ni-containing NPs with controlled and reduced toxicity, and also provide the scientific basis for developing nanoparticle exposure limits and policies.

Dihydromyricetin ameliorates experimental ulcerative colitis by inhibiting neutrophil extracellular traps formation via the HIF-1α/VEGFA signaling pathway.

Dihydromyricetin (DHM), which has various biological functions, possesses therapeutic potential for ulcerative colitis (UC). Neutrophil extracellular traps (NETs) and their components play a crucial role in several pathological processes in UC. However, whether DHM alleviates UC by regulating NETs remains unclear. Mice with dextran sulfate sodium (DSS)-induced acute colitis were treated with DHM at different concentrations, and the severity of colitis was evaluated by assessing body weight, colon length, histological scores, cytokine production, and epithelial barrier integrity. To quantify and visualize NETs, the expression of cell free-DNA (cf-DNA) in serum and Cit-H3 in colonic tissue was analyzed via western blotting and immunofluorescence analysis. HL-60 cells and mouse bone marrow-derived neutrophils (BMDNs) were used to evaluate the effects of DHM on NETs in vitro. NETs were treated with DHM at varying concentrations or DNase I and used to repair the intestinal epithelial barrier in a Caco-2/HIEC-6 cell monolayer model. Furthermore, the genes targeted by DHM through neutrophils for alleviating UC were identified by screening online databases, and the results of network pharmacological analysis were verified via western blotting and quantitative real-time polymerase chain reaction. DHM alleviated DSS-induced colitis in mice by reversing weight loss, increased DAI score, colon length shortening, enhanced spleen index, colonic pathological damage, cytokine production, and epithelial barrier loss in a dose-dependent manner. In addition, it inhibited the formation of NETs both in vivo and in vitro. Based on the results of network pharmacological analysis, DHM may target HIF-1α and VEGFA through neutrophils to alleviate UC. Treatment with PMA increased the expression of HIF-1α and VEGFA in D-HL-60 cells and BMDNs, whereas treatment with DHM or DNase I reversed this effect. Treatment with DMOG, an inhibitor of HIF prolyl hydroxylase (HIF-PH), counteracted the suppressive effects of DHM on NETs formation in D-HL-60 cells and BMDNs. Accordingly, it partially counteracted the protective effects of DHM on the intestinal epithelial barrier in Caco-2 and HIEC-6 cells. These results indicated that DHM alleviated DSS-induced UC by regulating NETs formation via the HIF-1α/VEGFA signaling pathway, suggesting that DHM is a promising therapeutic candidate for UC.

The long non-coding RNA mir155hg promotes NLRP3-inflammasome activation and oxidative stress response in acute lung injury by targeting miR-450b-5p to regulate HIF-1α.

BACKGROUND: Acute lung injury (ALI) can cause multiple organ dysfunction and a high mortality rate. Inflammatory responses, oxidative stress, and immune damage contribute to their pathogenic mechanisms. We studied the role of the newly discovered lncRNA, Lncmir155hg, in ALI. METHODS: The levels of Lncmir155hg and miR-450b-5p from mice with ALI were detected via polymerase chain reaction analysis (qRT-PCR) and Fluorescence in situ hybridization (FISH). Pathological changes of lung were detected by HE (hematoxylin and eosin) staining, and HIF-1α, NOD-like receptor 3 (NLRP3) and caspase-1 protein changes were detected by immunohistochemistry. MLE-12 cells proliferation was detected by Cell-Counting Kit 8 analysis, and reactive oxygen species (ROS) was detected via flow cytometry. NLRP3, apoptosis-associated speck-like protein (ASC), and caspase-1 were measured via western blotting, and enzyme-linked immunosorbent assays detected the expression of Inflammatory factors. Lncmir155hg, miR-450b-5p, miR-450b-5p, and HIF-1α targets were predicted using LncTar and miRWalk and confirmed in dual-luciferase reporter assays. RESULTS: In mice with ALI and MLE-12 cells induced by lipopolysaccharide (LPS), Lncmir155hg was high-expressed and miR-450b-5p was low-expressed. sh-Lncmir155hg reduced the damage of lung tissue, the production of inflammatory cytokines and oxidative stress reaction induced by LPS，miR-450b-5p reverses the effect of Lncmir155hg in mice. sh-Lncmir155hg decreased the protein levels of HIF-1α, NLRP3 and caspase-1 in LPS-induced lung tissues. sh-Lncmir155hg+miR-450b-5p inhibitor transfection reversed the effect of sh-Lncmir155hg on the expression of HIF-1α, NLRP3 and caspase-1. Lncmir155hg knockdown induced proliferation and inhibited NLRP3-inflammasome activation and oxidative stress in MLE-12 cells of ALI. miR-450b-5p was identified to have binding with Lncmir155hg, and inhibition of miR-450b-5p eliminated the effect of si-Lncmir155hg in MLE-12 cells of ALI. More importantly, miR-450b-5p was directly combined with HIF-1α, miR-450b-5p mimic promoted proliferation and inhibited activation of inflammasome associated proteins and reaction of oxidative stress, and HIF-1α overexpression abolished these effects. CONCLUSION: Lncmir155hg aggravated ALI via the miR-450b-5p/HIF-1α axis.

Discovery of DS-1093a: An oral hypoxia-inducible factor prolyl hydroxylase inhibitor for the treatment of renal anemia.

Inhibition of the hypoxia-inducible factor prolyl hydroxylase (HIF-PHD) represents a promising strategy for discovering next-generation treatments for renal anemia. We discovered DS44470011 in our previous study, which showed potent in vitro activity and in vivo efficacy based on HIF-PHD inhibition. However, DS44470011 was also found to exert genotoxic effects. By converting the biphenyl structure, which is suspected to be the cause of this genotoxicity, to a 1-phenylpiperidine structure, we were able to avoid genotoxicity and further improve the in vitro activity and in vivo efficacy. Furthermore, through the optimization of pyrimidine derivatives, we discovered DS-1093a, which has a wide safety margin with potent in vitro activity and an optimal pharmacokinetic profile. DS-1093a achieved an increase in hemoglobin levels in an adenine-induced rat model of chronic kidney disease after its continuous administration for 4 days.

A gene for all seasons: The evolutionary consequences of HIF-1 in carcinogenesis, tumor growth and metastasis.

Oxygen played a pivotal role in the evolution of multicellularity during the Cambrian Explosion. Not surprisingly, responses to fluctuating oxygen concentrations are integral to the evolution of cancer-a disease characterized by the breakdown of multicellularity. Poorly organized tumor vasculature results in chaotic patterns of blood flow characterized by large spatial and temporal variations in intra-tumoral oxygen concentrations. Hypoxia-inducible growth factor (HIF-1) plays a pivotal role in enabling cells to adapt, metabolize, and proliferate in low oxygen conditions. HIF-1 is often constitutively activated in cancers, underscoring its importance in cancer progression. Here, we argue that the phenotypic changes mediated by HIF-1, in addition to adapting the cancer cells to their local environment, also "pre-adapt" them for proliferation at distant, metastatic sites. HIF-1-mediated adaptations include a metabolic shift towards anaerobic respiration or glycolysis, activation of cell survival mechanisms like phenotypic plasticity and epigenetic reprogramming, and formation of tumor vasculature through angiogenesis. Hypoxia induced epigenetic reprogramming can trigger epithelial to mesenchymal transition in cancer cells-the first step in the metastatic cascade. Highly glycolytic cells facilitate local invasion by acidifying the tumor microenvironment. New blood vessels, formed due to angiogenesis, provide cancer cells a conduit to the circulatory system. Moreover, survival mechanisms acquired by cancer cells in the primary site allow them to remodel tissue at the metastatic site generating tumor promoting microenvironment. Thus, hypoxia in the primary tumor promoted adaptations conducive to all stages of the metastatic cascade from the initial escape entry into a blood vessel, intravascular survival, extravasation into distant tissues, and establishment of secondary tumors.

Roxadustat-Induced Central Hypothyroidism in Renal Anemia Patients: Insights From Antineutrophil Cytoplasmic Antibody-Related Vasculitis Cases.

The introduction of hypoxia-inducible factor-prolyl hydroxylase (HIF-PH) inhibitors in Japan in 2019 for treating renal anemia in hemodialysis patients has resulted in an adverse event: central hypothyroidism. Although this adverse event was not widely recognized by the public, it was first documented in Japan in 2021. Despite limited case reports on roxadustat, an oral HIF-PH inhibitor that induces central hypothyroidism, this condition typically improves rapidly upon discontinuation of the drug. In this report, we present rare cases of roxadustat-induced central hypothyroidism in two patients: a woman in her 80s and a man in his 60s, neither of whom had prior thyroid disease. Both patients developed central hypothyroidism shortly after starting roxadustat treatment for renal anemia associated with antineutrophil cytoplasmic antibody-related vasculitis. Notably, neither patient had pituitary tumors or other pituitary hormone disorders. Thyroid function improved with levothyroxine treatment, even when oral roxadustat was continued. Roxadustat may induce central hypothyroidism, highlighting the importance of regularly measuring and evaluating thyroid function when administering this drug to monitor possible changes in thyroid hormone levels.

Simultaneous detection of three hypoxia-inducible factor stabilizers-molidustat, roxadustat, and vadadustat-in multiple keratinized matrices and its application in a doping context.

In a doping case, a top athlete challenged an anti-doping rule violation, involving molidustat. Molidustat is a stabilizing agent of the hypoxia-inducible factor (HIF) recently developed. It is currently undergoing clinical trials for anemia associated with chronic kidney disease. HIF stabilizers are banned at all times by the World Anti-Doping Agency (class S2). Because of their pharmacological proprieties, these new drugs can enhance athletic performance. The athlete's defense wanted to analyze multiple keratinized matrices as they allow long-term investigations. Requests concerning HIF stabilizers are constantly growing. We have therefore developed a liquid chromatography coupled with tandem mass spectrometry method to identify and quantify three molecules of this class: molidustat, vadadustat, and roxadustat. Thirty milligrams of keratinized matrices were incubated in 1 mL of pH 8.4 diammonium hydrogen phosphate buffer for 16 h at 40°C with 1 ng of testosterone-D3, used as internal standard. After extraction with ethyl acetate/diethyl ether (80/20), the organic phase was evaporated, and the dry residue was reconstituted in 30 µL of initial phase. The method was linear from 5 to 1000 pg/mg for the three analytes. Limits of quantification were 2, 0.5, and 5 pg/mg for molidustat, roxadustat, and vadadustat, respectively. The analysis of the athlete's head hair (collected 1 month after the urine test) showed a concentration of molidustat of 135 pg/mg, and his beard hair and his fingernails clippings contained 55 and 40 pg/mg, respectively.

Arsenic activated GLUT1-mTORC1/HIF-1α-PKM2 positive feedback networks promote proliferation and migration of bladder epithelial cells.

Arsenic (As) is recognized as a potent environmental contaminant associated with bladder carcinogenesis. However, its molecular mechanism remains unclear. Metabolic reprogramming is one of the hallmarks of cancer and is as a central feature of malignancy. Here, we performed the study of cross-talk between the mammalian target of rapamycin complex 1 (mTORC1)/ Hypoxia-inducible factor 1 alpha (HIF-1α) pathway and aerobic glycolysis in promoting the proliferation and migration of bladder epithelial cells treated by arsenic in vivo and in vitro. We demonstrated that arsenite promoted N-methyl-N-nitrosourea (MNU)-induced tumor formation in the bladder of rats and the malignant behavior of human ureteral epithelial (SV-HUC-1) cell. We found that arsenite positively regulated the mTORC1/HIF-1α pathway through glucose transporter protein 1 (GLUT1), which involved in the malignant progression of bladder epithelial cells relying on glycolysis. In addition, pyruvate kinase M2 (PKM2) increased by arsenite reduced the protein expressions of succinate dehydrogenase (SDH) and fumarate hydratase (FH), leading to the accumulation of tumor metabolites of succinate and fumarate. Moreover, heat shock protein (HSP)90, functioning as a chaperone protein, stabilized PKM2 and thereby regulated the proliferation and aerobic glycolysis in arsenite treated SV-HUC-1 cells. Taken together, these results provide new insights into mTORC1/HIF-1α and PKM2 networks as critical molecular targets that contribute to the arsenic-induced malignant progression of bladder epithelial cells.

High-intensity interval training improves hypothalamic inflammation by suppressing HIF-1α signaling in microglia of male C57BL/6J mice.

Repeated bouts of high-intensity interval training (HIIT) induce an improvement in metabolism via plasticity of melanocortin circuits and attenuated hypothalamic inflammation. HIF-1α, which plays a vital role in hypothalamus-mediated regulation of peripheral metabolism, is enhanced in the hypothalamus by HIIT. This study aimed to investigate the effects of HIIT on hypothalamic HIF-1α expression and peripheral metabolism in obese mice and the underlying molecular mechanisms. By using a high-fat diet (HFD)-induced obesity mouse model, we determined the effect of HIIT on energy balance and the expression of the hypothalamic appetite-regulating neuropeptides, POMC and NPY. Moreover, hypothalamic HIF-1α signaling and its downstream glycolytic enzymes were explored after HIIT intervention. The state of microglia and microglial NF-κB signaling in the hypothalamus were also examined in vivo. In vitro by using an adenovirus carrying shRNA-HIF1ß, we explored the impact of HIF-1 signaling on glycolysis and NF-κB inflammatory signaling in BV2 cells. Food intake was suppressed and whole-body metabolism was improved in exercised DIO mice, accompanied by changes in the expression of POMC and NPY. Moreover, total and microglial HIF-1α signaling were obviously attenuated in the hypothalamus, consistent with the decreased levels of glycolytic enzymes. Both HFD-induced microglial activation and hypothalamic NF-κB signaling were significantly suppressed following HIIT in vivo. In BV2 cells, after HIF-1 complex knockdown, glycolysis and NF-κB inflammatory signaling were significantly attenuated. The data indicate that HIIT improves peripheral metabolism probably via attenuated HFD-induced microglial activation and microglial NF-κB signaling in the hypothalamus, which could be mediated by suppressed microglial HIF-1α signaling.

Recent progress in the development of hypoxia-inducible factor 2α (HIF-2α) modulators: Inhibitors, agonists, and degraders (2009-2024).

Hypoxia-inducible factor 2α (HIF-2α) is a critical transcription factor that regulates cellular responses under hypoxic conditions. In situations of insufficient oxygen supply or patients with Von Hippel-Lindau (VHL) mutations, HIF-2α accumulates and forms a heterodimeric complex with aryl hydrocarbon receptor nuclear translocator (ARNT, or HIF-ß). This complex further binds to coactivator p300 and interacts with hypoxia response elements (HREs) on the DNA of downstream target genes, regulating the transcription of a variety of genes (e.g. VEGFA, CCND1, CXCR4, SLC2A1, etc) involved in various processes like angiogenesis, mitochondrial metabolism, cell proliferation, and metastasis. Targeting HIF-2α holds great promise for effectively addressing solid tumors associated with aberrant oxygen-sensing pathways and hypoxia mechanisms, offering broad application prospects. In this review, we provide an overview of recent advancements (2009-2024) in HIF-2α modulators such as inhibitors, agonists, and degraders for cancer therapy. Additionally, we discuss in detail the challenges and future directions regarding HIF-2α modulators.

HIF-1 mediated metabolic reprogramming in cancer: Mechanisms and therapeutic implications.

Cancer cells undergo metabolic reprogramming to survive in hypoxic conditions and meet the elevated energy demands of the cancer microenvironment. This metabolic alteration is orchestrated by hypoxia-inducible factor 1 (HIF-1), regulating various processes within cancer cells. The intricate metabolic modifications induced by hypoxia underscore the significance of HIF-1-induced metabolic reprogramming in promoting each aspect of cancer progression. The complex interactions between HIF-1 signalling and cellular metabolic processes in response to hypoxia are examined in this study, focusing on the metabolism of carbohydrates, nucleotides, lipids, and amino acids. Comprehending the various regulatory mechanisms controlled by HIF-1 in cellular metabolism sheds light on the intricate biology of cancer growth and offers useful insights for developing targeted treatments.