BACKGROUND: Asthma is a common chronic inflammatory airway disease and intermittent hypoxia is increasingly recognized as a factor that may impact disease progression. The present study investigated whether intermittent hypoxia (IH) could aggravate asthma by promoting hypoxia-inducible factor-1α (HIF-1α)/nucleotide-binding oligomerization domain (NOD)-like receptor pyrin domain-containing protein 3 (NLRP3)/interleukin (IL)-1β-dependent pyroptosis and the inflammatory response and further elucidated the underlying molecular mechanisms involved. METHODS: A total of 49 patients diagnosed with severe bronchial asthma and diagnosed by polysomnography were enrolled at Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology, between January 2022 and December 2022, and their general data and induced sputum were collected. BEAS-2B cells were treated with IL-13 and subjected to IH. An ovalbumin (OVA)-treated mouse model was also used to assess the effects of chronic intermittent hypoxia (CIH) on asthma. Pyroptosis, the inflammatory response, and related signalling pathways were assessed in vivo and in vitro . RESULTS: In this study, as the apnoea and hypopnea index (AHI) increased, the proportion of patients with uncontrolled asthma increased. The proportions of neutrophils and the levels of IL-6, IL-8, HIF-1α and NLRP3 in induced sputum were related to the AHI. NLRP3-mediated pyroptosis, which could be mediated by the HIF-1α signalling pathway, was activated in IL-13 plus IH-treated BEAS-2B cells and in the lungs of OVA/CIH mice. HIF-1α downregulation significantly reduced lung pyroptosis and ameliorated neutrophil inflammation by modulating the NLRP3/IL-1β pathway both in vitro and in vivo . Similarly, pretreatment with LW6, an inhibitor of HIF-1α, effectively blocked the generation of inflammatory cytokines in neutrophils. In addition, administration of the NLRP3 activator nigericin obviously increased lung neutrophil inflammation. CONCLUSIONS Obstructive sleep apnoea-hypopnea syndrome (OSAHS) is a risk factor for asthma exacerbation. IH aggravates neutrophil inflammation in asthma via NLRP3/IL-1β-dependent pyroptosis mediated by the HIF-1α signalling pathway, which should be considered a potential therapeutic target for the treatment of asthma with OSAHS.
NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Humans ; Asthma/metabolism* ; Animals ; Pyroptosis/physiology* ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Mice ; Signal Transduction/physiology* ; Male ; Hypoxia/metabolism* ; Female ; Interleukin-1beta/metabolism* ; Adult ; Inflammation/metabolism* ; Middle Aged ; Mice, Inbred C57BL

Heat acclimation provides cardiovascular protection in high-temperature environments through multilevel mechanisms; however, the complete molecular basis of its effects remains unclear. In this paper, we systematically review the effects of heat acclimation on blood volume, vascular function, cardiac structure, energy metabolism, and anti-stress regulation, revealing their potential mechanisms in cardiovascular adaptive protection. We also summarizes the multilevel responses induced by heat stress and heat acclimation, including the modulatory effects of heat acclimation on heat shock proteins (HSPs), hypoxia inducible factor 1 (HIF-1), and apoptotic pathways. Additionally, we highlights the comprehensive protective effects of heat acclimation across various stressors (e.g., hypoxia, heat stress). This review provides a significant physiological basis for cardiovascular disease management and sports medicine, emphasizing the potential application of heat acclimation in response to multiple stressors and supporting its role as an effective tool in cardiovascular health management and stress protection interventions.
Humans ; Acclimatization/physiology* ; Hot Temperature ; Heat-Shock Proteins/metabolism* ; Animals ; Heat-Shock Response/physiology* ; Hypoxia-Inducible Factor 1/metabolism* ; Apoptosis/physiology*

This work aims to explore the effect of glycolysis on the replication of porcine reproductive and respiratory syndrome virus (PRRSV) in porcine alveolar macrophages (PAMs). The changes of glucose metabolism, PRRSV protein levels, PRRSV titers, and the relative expression levels of genes and proteins in PAMs were analyzed by ELISA, qPCR, virus titration, and Western blotting after PRRSV infection. The effect of hypoxia-inducible factor-1α (HIF-1α) on PRRSV replication was subsequently assessed by specific siRNAs targeting to HIF-1α. The results showed that PRRSV infection enhanced glycolysis, elevated the levels of glucose uptake and lactate in the supernatant (P<0.05 and 0.01, respectively), reduced ATP production (P<0.05), and up-regulated the expression of hexokinase 2 (HK2), 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3), and pyruvate kinase isozyme type M2 (PKM2) in PAMs (P<0.05 and 0.01, respectively). Glycolysis inhibitors down-regulated the expression of PRRSV proteins and reduced virus titers (P<0.01). The knockdown of HIF-1α by siRNAs inhibited glycolysis and lowered PRRSV titers (P<0.05). In addition, the interferon pathways inhibited by PRRSV infection were reversed by the inhibition of glycolysis. These findings may facilitate further investigation of the role of glycolysis in PRRSV replication.
Porcine respiratory and reproductive syndrome virus/physiology* ; Glycolysis ; Swine ; Animals ; Virus Replication ; Hypoxia-Inducible Factor 1, alpha Subunit/genetics* ; Macrophages, Alveolar/metabolism* ; Porcine Reproductive and Respiratory Syndrome/virology* ; Cells, Cultured ; RNA, Small Interfering/genetics*

Objective: To investigate the mechanism that hypoxia promotes the migration of lung adenocarcinoma A549 cells. Methods: A549 cells were cultured and cells that knockdown of acetyl-CoA carboxylase 1 (ACC1) were obtained by transfection with lentivirus, and cells that knockdown of sterol regulatory element-binding proteins-1 (SREBP-1) were obtained by treated with si-RNA. A549 cells were treated with hypoxia combined with hypoxia inducible factor-1α (HIF-1α) inhibitor PX-478 (25 μmol); Hypoxia combined with linoleic acid (LA) (20 μmol) treated A549 cells with ACC1 knockdown, and A549 cells with SREBP-1 knockdown were treated by hypoxia. Transwell migration assay was used to detect cell migration. Western blot was conducted to detect HIF-1α, ACC1 and epithelial mesenchymal transition (EMT) related proteins, Vimentin, E-Cadherin and SREBP-1; Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) was performed to detect the changes of ACC1 and SREBP-1 mRNA in A549 cells after hypoxia and HIF-1α inhibitor PX-478 (25 μmol) treatment. Each experiment was repeated three times. Results: Compared with the normoxic control group, hypoxia promoted the migration of A549 cells (P＜0.01), and up-regulated the expressions of ACC1, HIF-1α (all P＜0.01) and SREBP-1 (P＜0.05). PX-478 (25 μmol) inhibited the migration of A549 cells induced by hypoxia and down-regulated the expression of SREBP-1 (all P＜0.05). ACC1 mRNA and SREBP-1 mRNA levels were increased after hypoxia treatment of A549 cells (all P＜0.05). The levels of ACC1 mRNA and SREBP-1 mRNA were decreased after A549 cells treated with hypoxia combined with PX-478 (25 μmol) for 24 h (P＜0.05, P＜0.01). Knockdown of SREBP-1 in A549 cells was obtained by transfection with si-RNA. Transwell migration assay showed the number of cell migration in si-SREBP-1 group was less than that in normoxia control group (P＜0.01). The si-SREBP-1 group and the si-NC group were treated with hypoxia. Compared with the control group, the number of cell migration in the si-SREBP-1 group was decreased (P＜0.01), however, the difference was not statistically significant compared with the normoxia si-SREBP-1 group (P＞0.05). Western blot showed that the expression of ACC1 in the si-SREBP-1 group was lower than that in the control group (P＜0.01). Compared with the control group, the expression of ACC1 was decreased after si-SREBP-1 group treated with hypoxia (P＜0.01). Knockdown of ACC1 inhibited the migration of A549 cells (P＜0.05). After knockdown of ACC1, the migration number of A549 cells under normoxia and 5% O₂ conditions had no significant difference (P＞0.05). Application of LA under hypoxia condition rescued ACC1-knockdown induced inhibitory effect on hypoxia-promoted A549 cell migration (P＜0.05). Conclusion: Hypoxia promotes migration of lung adenocarcinoma A549 cells by regulating fatty acid metabolism through HIF-1α/SREBP-1/ACC1 pathway.
A549 Cells ; Acetyl-CoA Carboxylase ; Adenocarcinoma of Lung ; Cell Hypoxia/physiology* ; Cell Line, Tumor ; Humans ; Hypoxia ; Hypoxia-Inducible Factor 1, alpha Subunit ; Lung Neoplasms ; RNA/metabolism* ; RNA, Messenger/metabolism* ; Sterol Regulatory Element Binding Protein 1/metabolism*

Hypoxia-inducible factor 1 (HIF-1), as a main transcriptional regulator of metabolic adaptation to changes in the oxygen environment, participates in many physiological and pathological processes in the body, and is closely related to the pathogenesis of many diseases. This review outlines the mechanisms of HIF-1 activation, its signaling pathways, natural inhibitors, and its roles in diseases. This article can provide new insights in the diagnosis and treatment of human diseases, and recent progress on the development of HIF-1 inhibitors.
Disease ; Humans ; Hypoxia-Inducible Factor 1/physiology* ; Oxygen ; Signal Transduction

Drug metabolism is significantly affected under hypoxia environment with changes of pharmacokinetics, expression and function of drug-metabolizing enzymes and transporters. Studies have shown that hypoxia increases the release of a series of inflammatory cytokines which can modulate drug metabolism. Besides, both hypoxia inducible factor 1α (HIF-1α) and microRNA-mediated pathways play a role in regulating drug metabolism. This article reviewed the impact and single-factor modulating mechanisms of drug metabolism under hypoxia, and put forward the speculation and prospects of multi-factor modulating mechanisms.
Cell Hypoxia ; Humans ; Hypoxia ; Hypoxia-Inducible Factor 1, alpha Subunit ; physiology ; Membrane Transport Proteins ; physiology ; MicroRNAs ; physiology ; Pharmaceutical Preparations ; metabolism

OBJECTIVETo explore the role of HIF1α gene in prostate cancer cell line DU145 by knocking it out with a novel gene-editing tool CRISPR/cas9 system.

METHODSA CRISPR/cas9 system with two sgRNAs targeting exon 1 of the HIF1α gene was constructed for the knock out experiment. CCK8 assay and transwell experiment were carried out to assess the effect of the knock out on the proliferation, migration and invasiveness of DU145 cells.

RESULTSThe efficiency of gene-targeting was measured through a T7E1 assaying and sequence analysis, which confirmed that the partial knock out was successful and has led to a significant decrease in the expression of HIF1α and inhibition of cell proliferation, migration and invasiveness.

CONCLUSIONA CRISPR/cas9 system for the knock out of HIF1α has been successfully constructed, which could inhibit the proliferation and migration of DU145 cells. The system can facilitate further studies of the HIF1α gene and its roles in tumorigenesis.

CRISPR-Cas Systems ; genetics ; Cell Line, Tumor ; Cell Movement ; Cell Proliferation ; Gene Editing ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; physiology ; Male ; Neoplasm Invasiveness ; Prostatic Neoplasms ; pathology

LncRNA H19 encoded by the H19 imprinting gene plays an important regulatory role in the cell. Recently study has found that in hypoxic cells, the expression of H19 gene changes, and the transcription factors and protein involved in the expression change accordingly. Through the involvement of specific protein 1 (SP1), hypoxia-inducible factor-1α (HIF-1α) binds directly to the H19 promoter and induces the up-regulation of H19 expression under hypoxic conditions. The tumor suppressor protein p53 may also mediate the expression of the H19 gene, in part by interfering with HIF-la activity under hypoxia stress. The miR675-5p encoded by exon 1 of H19 promotes hypoxia response by driving the nuclear accumulation of HIF-1α and reducing the expression of VHL gene, which is a physiological HIF-1α inhibitor. In addition, under the condition of hypoxia, the expression of transporter on cell membrane changes, and the transition of the intracellular glucose metabolism pathway from aerobic oxidation to anaerobic glycolysis is also involved in the involvement of H19. Therefore, H19 may be a key gene that maintains intracellular balance under hypoxic conditions and drives adaptive cell survival under conditions of hypoxia stress.
Cell Hypoxia ; genetics ; Genes, Tumor Suppressor ; physiology ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; RNA, Long Noncoding ; Up-Regulation ; physiology ; Von Hippel-Lindau Tumor Suppressor Protein ; genetics

Hypoxia (low oxygen level) is an important feature during infections and affects the host defence mechanisms. The host has evolved specific responses to address hypoxia, which are strongly dependent on the activation of hypoxia-inducible factor 1 (HIF-1). Hypoxia interferes degradation of HIF-1 alpha subunit (HIF-1α), leading to stabilisation of HIF-1α, heterodimerization with HIF-1 beta subunit (HIF-1β) and subsequent activation of HIF-1 pathway. Apical periodontitis (periapical lesion) is a consequence of endodontic infection and ultimately results in destruction of tooth-supporting tissue, including alveolar bone. Thus far, the role of HIF-1 in periapical lesions has not been systematically examined. In the present study, we determined the role of HIF-1 in a well-characterised mouse periapical lesion model using two HIF-1α-activating strategies, dimethyloxalylglycine (DMOG) and adenovirus-induced constitutively active HIF-1α (CA-HIF1A). Both DMOG and CA-HIF1A attenuated periapical inflammation and tissue destruction. The attenuation in vivo was associated with downregulation of nuclear factor-κappa B (NF-κB) and osteoclastic gene expressions. These two agents also suppressed NF-κB activation and subsequent production of proinflammatory cytokines by macrophages. Furthermore, activation of HIF-1α by DMOG specifically suppressed lipopolysaccharide-stimulated macrophage differentiation into M1 cells, increasing the ratio of M2 macrophages against M1 cells. Taken together, our data indicated that activation of HIF-1 plays a protective role in the development of apical periodontitis via downregulation of NF-κB, proinflammatory cytokines, M1 macrophages and osteoclastogenesis.
Alveolar Bone Loss ; metabolism ; prevention & control ; Amino Acids, Dicarboxylic ; pharmacology ; Animals ; Cytokines ; metabolism ; Down-Regulation ; Gene Expression ; drug effects ; Hypoxia-Inducible Factor 1, alpha Subunit ; physiology ; Macrophages ; physiology ; Mice ; NF-kappa B ; metabolism ; Osteogenesis ; physiology ; Periapical Periodontitis ; metabolism ; prevention & control ; Real-Time Polymerase Chain Reaction ; X-Ray Microtomography

OBJECTIVETo study the expression and significance of the mammalian target of rapamycin (mTOR)/eukaryote initiating factor 4E binding protein 1(4EBP1)/hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) signaling pathway in asthmatic mice.

METHODSForty SPF level 6-8 week-old female Balb/C mice were randomly divided into control, asthma, budesonide and mTOR inhibitor (rapamycin) intervention groups (n=10 each). The asthmatic mouse model was prepared via OVA induction and challenge test. The intervention groups were administered with rapamycin at the dosage of 3 mg/kg by an intraperitoneal injection or budesonide suspension at the dosage of l mg by aerosol inhalation respectively 30 minutes before the OVA challenge. The control and asthma groups were treated with normal saline instead. The concentrations of HIF-1α and VEGF in bronchoalveolar lavage fluid (BALF) were examined using ELISA 24 hours after the last challenge. The pathological changes of lung tissue were observed by hematoxylin-eosin (HE) staining. The p-mTOR and p-4EBP1 from the lung tissues were detected by immunohistochemistry and Western blot. Pearson analysis was used to study the correlation between p-mTOR, p-4EBP1, HIF-1α, and VEGF expression.

RESULTSCompared with the control group, inflammatory cell infiltration and secretions in the trachea increased in the asthma group. The levels of HIF-1α and VEGF in BALF and p-mTOR and p-4EBP1 expression in lung tissues also increased (P<0.01). Compared with the asthma group, inflammatory cell infiltration and secretions in the trachea were reduced in the two intervention groups, and the levels of HIF-1α and VEGF in BALF and p-mTOR and p-4EBP1 expression in lung tissues were also reduced (P<0.01). There were no significant differences in the above changes between the two intervention groups and control group (P>0.05). In the asthma group, there was a pairwise positive correlation between lung p-mTOR and p-4EBP1 expression and HIF-1α and VEGF levels in BALF (P<0.05). However, there were no correlations in the above indexes in the intervention groups and control group.

CONCLUSIONSp-mTOR, p-4EBP1, HIF-1α and VEGF together are involved in the pathogenesis of asthma. Rapamycin treatment can block this signaling pathway, suggesting that this pathway can be used as a novel target for asthma treatment.

Animals ; Asthma ; drug therapy ; metabolism ; Carrier Proteins ; analysis ; physiology ; Female ; Hypoxia-Inducible Factor 1, alpha Subunit ; analysis ; physiology ; Lung ; chemistry ; pathology ; Mice ; Mice, Inbred BALB C ; Phosphoproteins ; analysis ; physiology ; Signal Transduction ; physiology ; TOR Serine-Threonine Kinases ; analysis ; physiology ; Vascular Endothelial Growth Factor A ; analysis ; physiology