Chronic hypoxia drives the occurrence of ferroptosis in liver of fat greening (Hexagrammos otakii) by activating HIF-1α and promoting iron production.

BACKGROUND: Hypoxia caused by global climate change and human activities has become a growing concern eliciting serious effect and damages to aquatic animals. Hexagrammos otakii is usually a victim of hypoxia which caused by high density aquaculture and high nutrient input. The mechanism underlying ferroptosis regulation after hypoxia-stress in liver of H. otakii, however, remains elusive. METHODS: For a duration of 15 days, expose the H. otakii to low concentrations of dissolved oxygen (3.4 ± 0.2 mg/L). Detecting alterations in the H. otakii liver tissue by chemical staining, immunohistochemistry, and electron microscopy. The expression variations of relevant genes in the liver of the H. otakii were simultaneously detected using Western blot and qPCR. A correlation analysis was performed between HIF-1α and iron ion expression in the liver of H. otakii following hypoxic stress. RESULTS: In this study, we conducted the whole ferroptosis integrated analysis of H. otakii under chronic hypoxic condition. Reactive oxygen species (ROS) are highly accumulated under the hypoxia treatment (Superoxide Dismutase, SOD; Catalase, CAT), and which results in a significantly enhanced of lipid peroxidation (Lipid Peroxidation, LPO; Malondialdehyde, MDA; Aminotransferase, AST; Alanine aminotransferase, ALT) in liver tissue. The HIF-1α signaling is activated to cope with the hypoxia stress through strategies including changing iron ion concentration (Fe3+ and TFR1) to breaking the oxidation balance (GSH and GSH-Px), and enhancing ferroptosis gene expression (GPX4). The expression of genes related to ferroptosis pathway (DMT1, FTH1, STEAP3, ACSL4, γ-GCS, SLC7A11) is significantly upregulated and associated to the expression of iron and HIF-1α. CONCLUSIONS: It is demonstrated that the HIF-1α/Fe3+/ROS/GPX4 axis is involved in promoting ferroptosis in fat greening hepatocytes following hypoxia-stress. Ultimately, our findings unveil a process by which hypoxic stress strongly encourages ferroptosis by triggering HIF-1α and boosting iron synthesis.

The Association of HIF-1α/rs2057482 Polymorphism with Idiopathic Scleritis in a Chinese Han Population.

BACKGROUND: To investigate the association of hypoxia-inducible factor-1α (HIF-1α), Janus tyrosine kinase-signal transducer and activator of transcription (JAK-STAT) gene polymorphisms with idiopathic scleritis in a Chinese Han population. METHODS: Ten single nucleotide polymorphisms (SNP) of HIF-1α, tyrosine kinase 2 (TYK2), signal transducer and activator of transcription 3 (STAT3), signal transducer and activator of transcription 4 (STAT4), and retinoid-related orphan nuclear receptors-γ (ROR-γ) were selected for this study. A total of 496 idiopathic scleritis patients and 1009 controls were genotyped by the MassARRAY platform and iPLEX Gold Genotyping Assay. The allele and genotype frequencies were analyzed by Chi-square test and Fisher's exact test. Stratified analyses were performed based on gender and anatomic locations of idiopathic scleritis. RESULTS: The frequencies of CC genotype (p = 6.18 × 10-4, Pc = 0.04, OR = 0.67,95%CI = 0.53-0.84) and C allele (p = 7.08 × 10-4, Pc = 0.04, OR = 0.71,95%CI = 0.58-0.87) for HIF-1α/rs2057482 were found significantly lower in idiopathic scleritis patients when compared to healthy controls. Stratified analysis depending on gender showed significant decreased frequencies of CC genotype (CC: p = 4.04 × 10-4, Pc = 0.02, OR = 0.54, 95%CI = 0.39-0.76) and C allele (C: p = 1.62 × 10-4, Pc = 0.01, OR = 0.58, 95%CI = 0.44-0.77) in male patients. Stratification analysis of rs2057482 according to location of scleritis did not show any significant difference between three subgroups and healthy controls. CONCLUSION: This study showed association between polymorphism of HIF-1α/rs2057482 and susceptibility to idiopathic scleritis in Han Chinese male patients.

Vitamin B12 ameliorates gut epithelial injury via modulating the HIF-1 pathway and gut microbiota.

Inflammatory bowel diseases (IBDs) are immune chronic diseases characterized by recurrent episodes, resulting in continuous intestinal barrier damage and intestinal microbiota dysbiosis. Safe strategies aimed at stabilizing and reducing IBDs recurrence have been vigorously pursued. Here, we constructed a recurrent intestinal injury Drosophila model and found that vitamin B12 (VB12), an essential co-factor for organism physiological functions, could effectively protect the intestine and reduce dextran sulfate sodium-induced intestinal barrier disruption. VB12 also alleviated microbial dysbiosis in the Drosophila model and inhibited the growth of gram-negative bacteria. We demonstrated that VB12 could mitigate intestinal damage by activating the hypoxia-inducible factor-1 signaling pathway in injured conditions, which was achieved by regulating the intestinal oxidation. In addition, we also validated the protective effect of VB12 in a murine acute colitis model. In summary, we offer new insights and implications for the potential supportive role of VB12 in the management of recurrent IBDs flare-ups.

Therapeutic effects of focused ultrasound on vulvar squamous intraepithelial lesions in rat.

OBJECTIVE: In this study, we established a Sprague-Dawley rat model of vulvar squamous intraepithelial lesions and investigated the impact of focused ultrasound on the expression of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and mutant type p53 (mtp53) in the vulvar skin of rats with low-grade squamous intraepithelial lesions (LSIL). MATERIALS AND METHODS: The vulvar skin of 60 rats was treated with dimethylbenzanthracene (DMBA) and mechanical irritation three times a week for 14 weeks. Rats with LSIL were randomly allocated into the experimental group or the control group. The experimental group was treated with focused ultrasound, while the control group received sham treatment. RESULTS: After 14 weeks treatment of DMBA combined with mechanical irritation, LSIL were observed in 44 (73.33%) rats, and high-grade squamous intraepithelial lesions (HSIL) were observed in 14 (23.33%) rats. 90.91% (20/22) of rats showed normal pathology and 9.09% (2/22) of rats exhibited LSIL in the experimental group at four weeks after focused ultrasound treatment. 22.73% (5/22) of rats exhibited LSIL, 77.27% (17/22) of rats progressed to HSIL in the control group. Compared with the control-group rats, the levels of HIF-1α, VEGF and mtp53 were significantly decreased in experimental-group rats (p < 0.05). CONCLUSIONS: These results indicate that DMBA combined with mechanical irritation can induce vulvar squamous intraepithelial lesion in SD rats. Focused ultrasound can treat LSIL safely and effectively, prevent the progression of vulvar lesions, and improve the microenvironment of vulvar tissues by decreasing the localized expression of HIF-1α, VEGF, and mtp53 in rats.

Role of HIF1A gene polymorphisms with serum uric acid and HIF-1α levels in monosodium urate crystal-induced arthritis.

BACKGROUND: Gouty arthritis is a metabolic disease characterized by the deposition of monosodium urate crystals in the joints, which triggers the release of interleukin-1ß (IL-ß) by activating the NLRP3 inflammasome. Hypoxia-inducible factor-1α (HIF-1α) is a transcription factor involved in IL-ß production and as a regulator of NLRP3. OBJECTIVES: The aims were to analyze the association of HIF1A rs11549465, rs11549467, and rs2057482 variants in patients with gouty arthritis, and to evaluate the correlation between urate and HIF-1α levels according to the associated genotypes. METHODS: Cases and controls were genotyped using TaqMan probes, and urate and HIF-1α levels were quantified. Data were analyzed using SPSS v21 software and P-values < 0.05 were considered statistically significant. RESULTS: Urate and HIF-1α levels were higher in patients than in controls (P < 0.05). Under the three inheritance models (codominant, dominant, and recessive), the AA genotype of the rs11549467 variant was associated with gout risk (OR = 5.74, P = 0.009, OR = 3.33, P = 0.024, and OR = 9.09, P = 0.003, respectively). There were significant differences in the distribution of serum levels of both HIF-1α (P < 0.0001) and urate (P = 0.016) according to the genotypes of the rs11549467 variant. CONCLUSION: These results suggest that the HIF1A rs11549467 variant may play a key role in the pathogenesis of gouty arthritis. Key Points • The pathogenesis of gouty arthritis involves the HIF1A gene. • In patients with gout, the AA genotype of the rs11549467 (HIF1A) variant is associated with increased serum levels of urate and HIF-1α. • HIF-1α is involved in the regulation of IL-1ß and NLRP3.

Thermosensitive Hydrogel with Programmable, Self-Regulated HIF-1α Stabilizer Release for Myocardial Infarction Treatment.

HIF-1α (hypoxia induced factor-1α), a vital protective signal against hypoxia, has a short lifetime after myocardial infarction (MI). Increasing HIF-1α stability by inhibiting its hydroxylation with prolyl hydroxylases inhibitors such as DPCA (1,4-dihydrophenonthrolin-4-one-3-carboxylic acid) presents positive results. However, the optimal inhibitor administration profile for MI treatment is still unexplored. Here, injectable, thermosensitive hydrogels with programmable DPCA release are designed and synthesized. Hydrogel degradation and slow DPCA release are coupled to form a feedback loop by attaching pendant DPCA to polymer backbone, which serve as additional crosslinking points through π-π and hydrophobic interactions. Pendant carboxyl groups are added to the copolymer to accelerate DPCA release. Burst release in the acute phase for myocardial protection and extended near zero-order release across the inflammatory and fibrotic phases with different rates are achieved. All DPCA-releasing hydrogels upregulate HIF-1α, decrease apoptosis, promote angiogenesis, and stimulate cardiomyocyte proliferation, leading to preserved cardiac function and ventricular geometry. Faster hydrogel degradation induced by faster DPCA release results in a HIF-1α expression eight times of healthy control and better therapeutic effect in MI treatment. This research demonstrates the value of precise regulation of HIF-1α expression in treating MI and other relevant diseases and provides an implantable device-based modulation strategy.

Paeoniae radix alba improved intestinal mucosal microcirculation disturbance by regulating lncRNA MALAT1/HIF-1α pathway in the treatment of ulcerative colitis.

BACKGROUND: Microcirculatory problems in the intestinal mucosa are the primary cause of ulcerative colitis (UC). Although UC is commonly treated with paeoniae radix alba (PRA), its exact mechanism of action is unclear. PURPOSE: To examine how PRA affects UC induced by dextran sulfate sodium (DSS) and the mechanism of its effects. METHODS: The primary active components of PRA were identified using high-performance liquid chromatography (HPLC), and network pharmacology techniques were used to predict the possible targets of action and signaling pathways in treatment for UC. A model of UC was established in vivo using rats, and a PRA intervention was performed. The amounts of cytokines in the colonic tissues and serum were measured using enzyme-linked immunosorbent assay (ELISA). The permeability of the intestinal mucosa was measured using a fluorescein isothiocyanate (FITC)-dextran assay and western blot. A PeriCam PSI system was used to view the microcirculation of the intestinal mucosa, and immunohistochemistry and immunofluorescence stains were used to detect angiogenesis. An electron microscope was used to observe the damage to the endothelium of the colon. Western blot and immunohistochemistry analyses were used to evaluate the protein expression of hypoxia-inducible factor-1 alpha (HIF-1α) in colon tissues, and qRT-PCR was used to assess the lncRNA expression of MALAT1. RESULTS: HPLC identified 10 main active components of PRA, and the network pharmacology results showed that the treatment of UC with PRA was associated with the HIF-1 signaling pathway. The results of animal experiments revealed that PRA significantly improved the pathological damage to the colon and the microcirculatory issues in the intestinal mucosa. PRA also inhibited colonic endothelial cell damage and angiogenesis, which may be related to the inhibition of the increased expression of lncRNA MALAT1 and HIF-1α in colon tissues. CONCLUSIONS: The anti-UC effect of PRA by improving intestinal mucosal microcirculatory disorders was first reported in this study. PRA deactivated the lncRNA MALAT1/HIF-1α pathway, inhibited endothelial angiogenesis, restored intestinal mucosal microvascular homeostasis, improved microcirculatory disorders, and alleviated the symptoms of DSS-induced UC in rats.

Qishen Granules Modulate Metabolism Flexibility Against Myocardial Infarction via HIF-1 α-Dependent Mechanisms in Rats.

OBJECTIVE: To assess the cardioprotective effect and impact of Qishen Granules (QSG) on different ischemic areas of the myocardium in heart failure (HF) rats by evaluating its metabolic pattern, substrate utilization, and mechanistic modulation. METHODS: In vivo, echocardiography and histology were used to assess rat cardiac function; positron emission tomography was performed to assess the abundance of glucose metabolism in the ischemic border and remote areas of the heart; fatty acid metabolism and ATP production levels were assessed by hematologic and biochemical analyses. The above experiments evaluated the cardioprotective effect of QSG on left anterior descending ligation-induced HF in rats and the mode of energy metabolism modulation. In vitro, a hypoxia-induced H9C2 model was established, mitochondrial damage was evaluated by flow cytometry, and nuclear translocation of hypoxia-inducible factor-1 α (HIF-1 α) was observed by immunofluorescence to assess the mechanism of energy metabolism regulation by QSG in hypoxic and normoxia conditions. RESULTS: QSG regulated the pattern of glucose and fatty acid metabolism in the border and remote areas of the heart via the HIF-1 α pathway, and improved cardiac function in HF rats. Specifically, QSG promoted HIF-1 α expression and entry into the nucleus at high levels of hypoxia (P<0.05), thereby promoting increased compensatory glucose metabolism; while reducing nuclear accumulation of HIF-1 α at relatively low levels of hypoxia (P<0.05), promoting the increased lipid metabolism. CONCLUSIONS: QSG regulates the protein stability of HIF-1 α, thereby coordinating energy supply balance between the ischemic border and remote areas of the myocardium. This alleviates the energy metabolism disorder caused by ischemic injury.

Adenosine A2B receptor activation regulates the balance between T helper 17 cells and regulatory T cells, and inhibits regulatory T cells exhaustion in experimental autoimmune myositis.

BACKGROUND: Idiopathic inflammatory myopathy (IIM) is a systemic autoimmune disease characterized by skeletal muscle involvement. This study aimed to investigate the role of adenosine receptor signalling pathways in the development of experimental autoimmune myositis (EAM). METHODS: An ecto-5'-nucleotidase (CD73) inhibitor, adenosine receptor agonists, a hypoxia-inducible factor-1α (HIF-1α) inhibitor or a vehicle were administered to control and EAM mice. Murine splenic CD4+ or regulatory T cells (Tregs) were isolated using magnetic beads and subsequently stimulated with an adenosine A2B receptor agonist, a HIF-1α inhibitor, or vehicle in vitro. In cross-sectional studies, we collected 64 serum samples (69% female, 49 ± 9 years), 63 peripheral blood samples (70% female, 50 ± 11 years), and 34 skeletal muscle samples (71% female, 63 ± 6 years) from patients with IIM. Additionally, 35 serum samples and 30 peripheral blood samples were obtained from age- and sex-matched healthy controls, and six quadriceps muscle samples were collected from patients with osteoarthritis to serve as the normal group. RESULTS: Patients with IIM exhibited increased CD73 [dermatomyositis (DM), polymyositis (PM): P < 0.01; immune-mediated necrotizing myopathy (IMNM): P < 0.0001] and adenosine deaminase (ADA) expression (DM: P < 0.001; PM, IMNM: P < 0.0001) in the skeletal muscles, and serum ADA levels [56.7 (95% CI: 53.7, 58.7) vs. 198.8 (95% CI: 186.2, 237.3) ng/µL, P < 0.0001]. Intervention with a CD73 inhibitor exacerbated (P = 0.0461), whereas adenosine receptor agonists (A1: P = 0.0009; A2B: P < 0.0001; A3: P = 0.0001) and the HIF-1α inhibitor (P = 0.0044) alleviated skeletal muscle injury in EAM mice. Elevated expression of programmed cell death protein-1 (PD1: P = 0.0023) and T-cell immunoglobulin and mucin-domain containing-3 (TIM3: P < 0.0001) in skeletal muscles of patients with IIM were correlated with creatine kinase levels (PD1, r = 0.7072, P < 0.0001; TIM3, r = 0.4808, P = 0.0046). PD1+CD4+ (r = 0.3243, P = 0.0115) and PD1+CD8+ (r = 0.3959, P = 0.0017) T cells were correlated with Myositis Disease Activity Assessment Visual Analogue Scale scores (muscle) in IIM. The exhausted Tregs were identified in the skeletal muscles of patients with IIM. Activation of the A2B adenosine receptor downregulated HIF-1α (protein or mRNA level, P < 0.01), resulting in decreased T helper cell 17 (Th17) (13.58% vs. 5.43%, P = 0.0201) and phosphorylated-signal transducer and activator of transcription 3 (p-STAT3)+ Th17 (16.32% vs. 6.73%, P = 0.0029), decreased exhausted Tregs (PD1+ Tregs: 53.55% vs. 40.28%, P = 0.0005; TIM3+ Tregs: 3.93% vs. 3.11%, P = 0.0029), and increased Tregs (0.45% vs. 2.89%, P = 0.0006) in EAM mice. CONCLUSIONS: The exhausted T cells may be pathogenic in IIM, and the activation of adenosine A2B receptor signalling pathway can regulate Th17/Treg balance and inhibit Tregs exhaustion, thereby slowing EAM disease progression.

HMGB1 derived from lung epithelial cells after cobalt nanoparticle exposure promotes the activation of lung fibroblasts.

We have previously demonstrated that exposure to cobalt nanoparticles (Nano-Co) caused extensive interstitial fibrosis and inflammatory cell infiltration in mouse lungs. However, the underlying mechanisms of Nano-Co-induced pulmonary fibrosis remain unclear. In this study, we investigated the role of high-mobility group box 1 (HMGB1) in the epithelial cell-fibroblast crosstalk in Nano-Co-induced pulmonary fibrosis. Our results showed that Nano-Co exposure caused remarkable production and release of HMGB1, as well as nuclear accumulation of HIF-1α in human bronchial epithelial cells (BEAS-2B) in a dose- and a time-dependent manner. Pretreatment with CAY10585, an inhibitor against HIF-1α, significantly blocked the overexpression of HMGB1 in cell lysate and the release of HMGB1 in the supernatant of BEAS-2B cells induced by Nano-Co exposure, indicating that Nano-Co exposure induces HIF-1α-dependent HMGB1 overexpression and release. In addition, treatment of lung fibroblasts (MRC-5) with conditioned media from Nano-Co-exposed BEAS-2B cells caused increased RAGE expression, MAPK signaling activation, and enhanced expression of fibrosis-associated proteins, such as fibronectin, collagen 1, and α-SMA. However, conditioned media from Nano-Co-exposed BEAS-2B cells with HMGB1 knockdown had no effects on the activation of MRC-5 fibroblasts. Finally, inhibition of ERK1/2, p38, and JNK all abolished MRC-5 activation induced by conditioned media from Nano-Co-exposed BEAS-2B cells, suggesting that MAPK signaling might be a key downstream signal of HMGB1/RAGE to promote MRC-5 fibroblast activation. These findings have important implications for understanding the pro-fibrotic potential of Nano-Co.

Transcriptomic analysis and validation study of key genes and the HIF­1α/HO­1 pathway associated with ferroptosis in neutrophilic asthma.

Ferroptosis, as a unique form of cell death caused by iron overload and lipid peroxidation, is involved in the pathogenesis of various inflammatory diseases of the airways. Inhibition of ferroptosis has become a novel strategy for reducing airway epithelial cell death and improving airway inflammation. The aim of the present study was to analyze and validate the key genes and signaling pathways associated with ferroptosis by bioinformatic methods combined with experimental analyzes in vitro and in vivo to aid the diagnosis and treatment of neutrophilic asthma. A total of 1,639 differentially expressed genes (DEGs) were identified in the transcriptome dataset. After overlapping with ferroptosis-related genes, 11 differentially expressed ferroptosis-related genes (DE-FRGs) were obtained. A new diagnostic model was constructed by these DE-FRGs from the transcriptome dataset with those from the GSE108417 dataset. The receiver operating characteristic curve analysis indicated that the area under the curve had good diagnostic performance (>0.8). As a result, four key DE-FRGs (CXCL2, HMOX1, IL-6 and SLC7A5) and biological pathway [hypoxia-inducible factor 1 (HIF-1) signaling pathway] associated with ferroptosis in neutrophilic asthma were identified by the bioinformatics analysis combined with experimental validation. The upstream regulatory network of key DE-FRGs and target drugs were predicted and the molecular docking results from screened 37 potential therapeutic drugs revealed that the 13 small-molecule drugs exhibited a higher stable binding to the primary proteins of key DE-FRGs. The results suggested that four key DE-FRGs and the HIF-1α/heme oxygenase 1 pathway associated with ferroptosis have potential as novel markers or targets for the diagnosis or treatment of neutrophilic asthma.

Identification of potential characteristic genes in chronic skin infections through RNA sequencing and immunohistochemical analysis.

The objective of the present study was to perform RNA sequencing and immunohistochemical analysis on skin specimens obtained from healthy individuals and individuals afflicted with prolonged skin infections. Bioinformatics methodologies were used to scrutinize the RNA sequencing data with the intention of pinpointing distinctive gene signatures associated with chronic skin infections. Skin tissue samples were collected from 11 individuals (4 subjects healthy and 7 patients with chronic skin infections) at the Affiliated Hospital of Southwest Medical University (Luzhou, China). The iDEP tool identified differentially expressed genes (DEGs) with log2 (fold change) ≥2 and q-value ≤0.01. Functional enrichment analysis using Gene Ontology and KEGG databases via the oebiotech online tool was then performed to determine the biological functions and pathways related to these DEGs. A protein-protein interaction network of DEGs identified HIF1A as a potential key gene. Subsequent immunohistochemistry analyses were performed on the samples to assess any variations in HIF1A expression. A total of 900 DEGs, 365 upregulated and 535 downregulated, were observed between the normal and chronic infection groups. The identified DEGs were found to serve a role in various biological processes, including 'hypoxia adaptation', 'angiogenesis', 'cell adhesion' and 'regulation of positive cell migration'. Additionally, these genes were revealed to be involved in the 'TGF-ß', 'PI3K-Akt' and 'IL-17' signaling pathways. HIF1A and nine other genes were identified as central nodes in the PPI network. HIF1A expression was higher in chronically infected skin samples than in healthy samples, indicating its potential as a novel research target.

Hypoxia-inducible Factor 1α Contributes to Matrix Metalloproteinases 2/9 and Inflammatory Responses in Periodontitis.

Periodontitis is a prevalent condition characterized by inflammation and tissue destruction within the periodontium, with hypoxia emerging as a contributing factor to its pathogenesis. Hypoxia-inducible factor 1α (HIF-1α) has a crucial role in orchestrating adaptive responses to hypoxic microenvironments and has been implicated in various inflammatory-related diseases. Understanding the interplay between HIF-1α, matrix metalloproteinases (MMPs), and inflammatory responses in periodontitis could provide insights into its molecular mechanisms. We investigated the relationship between HIF-1α, MMP2, and MMP9 in gingival crevicular fluid (GCF) and periodontal ligament stem cells (PDLSCs) from periodontitis patients. The expression levels of HIF-1α, MMP2, MMP9, and inflammatory factors (IL-6, IL-1ß, TNF-α) were assessed using enzyme-linked immunosorbent assay (ELISA) and real-time PCR (RT-PCR). Additionally, osteogenic differentiation of PDLSCs was identified by alkaline phosphatase activity. Significantly elevated levels of HIF-1α, MMP2, and MMP9 were observed in GCF of periodontitis patients compared to controls. Positive correlations were found between HIF-1α and MMP2/MMP9, as well as with IL-6, IL-1ß, and TNF-α. Modulation of HIF-1α expression in PDLSCs revealed its involvement in MMP2/9 secretion and inflammatory responses, with inhibition of HIF-1α mitigating these effects. Furthermore, HIF-1α inhibition alleviated the reduction in osteogenic differentiation induced by inflammatory stimuli. Our findings elucidate the regulatory role of HIF-1α in MMP expression, inflammatory responses, and osteogenic differentiation in periodontitis. In conclusion, targeting HIF-1α signaling pathways may offer therapeutic opportunities for managing periodontitis and promoting periodontal tissue regeneration.

Predictive value of serum HIF-1α/HIF-2α and YKL-40 levels for vascular invasion and prognosis of follicular thyroid cancer.

OBJECTIVE: This study investigated the significance of serum hypoxia-inducible factor (HIF)-1α/HIF-2 α and Chitinase 3-Like protein 1 (YKL-40) levels in the assessment of vascular invasion and prognostic outcomes in patients with Follicular Thyroid Cancer (FTC). METHODS: This prospective study comprised 83 patients diagnosed with FTC, who were subsequently categorized into a recurrence group (17 cases) and a non-recurrence group (66 cases). The pathological features of tumor vascular invasion were classified. Serum HIF-1α/HIF-2α and YKL-40 were quantified using a dual antibody sandwich enzyme-linked immunosorbent assay, while serum Thyroglobulin (Tg) levels were measured using an electrochemiluminescence immunoassay method. The Spearman test was employed to assess the correlation between serum factors, and the predictive value of diagnostic factors was determined using receiver operating characteristic curve analysis. A Cox proportional hazards regression model was utilized to analyze independent factors influencing prognosis. RESULTS: Serum HIF-1α, HIF-2α, YKL-40, and Tg were elevated in patients exhibiting higher vascular invasion. A significant positive correlation was observed between Tg and HIF-1α, as well as between HIF-1α and YKL-40. The cut-off values for HIF-1α and YKL-40 in predicting recurrence were 48.25 pg/mL and 60.15 ng/mL, respectively. Patients exceeding these cut-off values experienced a lower recurrence-free survival rate. Furthermore, serum levels surpassing the cut-off value, in conjunction with vascular invasion (v2+), were identified as independent risk factors for recurrence in patients with FTC. CONCLUSION: Serum HIF-1α/HIF-2α and YKL-40 levels correlate with vascular invasion in FTC, and the combination of HIF-1α and YKL-40 predicts recurrence in patients with FTC.

Role of HIF-1α-Activated IL-22/IL-22R1/Bmi1 Signaling Modulates the Self-Renewal of Cardiac Stem Cells in Acute Myocardial Ischemia.

Impaired tissue regeneration negatively impacts on left ventricular (LV) function and remodeling after acute myocardial infarction (AMI). Little is known about the intrinsic regulatory machinery of ischemia-induced endogenous cardiac stem cells (eCSCs) self-renewing divisions after AMI. The interleukin 22 (IL-22)/IL-22 receptor 1 (IL-22R1) pathway has emerged as an important regulator of several cellular processes, including the self-renewal and proliferation of stem cells. However, whether the hypoxic environment could trigger the self-renewal of eCSCs via IL-22/IL-22R1 activation remains unknown. In this study, the upregulation of IL-22R1 occurred due to activation of hypoxia-inducible factor-1α (HIF-1α) under hypoxic and ischemic conditions. Systemic IL-22 administration not only attenuated cardiac remodeling, inflammatory responses, but also promoted eCSC-mediated cardiac repair after AMI. Unbiased RNA microarray analysis showed that the downstream mediator Bmi1 regulated the activation of CSCs. Therefore, the HIF-1α-induced IL-22/IL-22R1/Bmi1 cascade can modulate the proliferation and activation of eCSCs in vitro and in vivo. Collectively, investigating the HIF-1α-activated IL-22/IL-22R1/Bmi1 signaling pathway might offer a new therapeutic strategy for AMI via eCSC-induced cardiac repair.

Message Transmission Between Adipocyte and Macrophage in Obesity.

Obesity is characterized by the chronic low-grade activation of the innate immune system. In this respect, macrophage-elicited metabolic inflammation and adipocyte-macrophage interaction have primary importance in obesity. Large quantity of macrophages is accumulated by different mechanisms in obese adipose tissue. Hypertrophic adipocyte-derived chemotactic monocyte chemoattractant protein-1 (MCP-1)/C-C chemokine receptor 2 (CCR2) pathway promotes more macrophage accumulation into the obese adipose tissue. However, obesity-induced changes in adipose tissue macrophage density are mainly dependent on increases in the triple-positive cluster of differentiation (CD)11b+ F4/80+ CD11c+ adipose tissue macrophage subpopulation. As epigenetic regulators, microRNAs (miRNAs) are one of the most important mediators of obesity. miRNAs are expressed by adipocytes as well as macrophages and regulate inflammation with the expression of target genes. A paracrine loop involving free fatty acids and tumor necrosis factor-alpha (TNF-α) between adipocytes and macrophages establishes a vicious cycle that aggravates inflammatory changes in the adipose tissue. Adipocyte-specific caspase-1 and production of interleukin-1beta (IL-1ß) by macrophages; both adipocyte and macrophage induction by toll-like receptor-4 (TLR4) through nuclear factor-kappaB (NF-κB) activation; free fatty acid-induced and TLR-mediated activation of c-Jun N-terminal kinase (JNK)-related pro-inflammatory pathways in CD11c+ immune cells; are effective in mutual message transmission between adipocyte and macrophage and in the development of adipose tissue inflammation. Thus, the metabolic status of adipocytes and their released exosomes are important determinants of macrophage inflammatory output. However, old adipocytes are removed by macrophages through trogocytosis or sending an "eat me" signal. As a single miRNA can be able to regulate a variety of target genes and signaling pathways, reciprocal transfer of miRNAs between adipocytes and macrophages via miRNA-loaded exosomes reorganizes the different stages of obesity. Changes in the expression of circulating miRNAs because of obesity progression or anti-obesity treatment indicate that miRNAs could be used as potential biomarkers. Therefore, it is believed that targeting macrophage-associated miRNAs with anti-obesity miRNA-loaded nano-carriers may be successful in the attenuation of both obesity and adipose tissue inflammation in clinical practice. Moreover, miRNA-containing exosomes and transferable mitochondria between the adipocyte and macrophage are investigated as new therapeutic targets for obesity-related metabolic disorders.

Activating UCHL1 through the CRISPR activation system promotes cartilage differentiation mediated by HIF-1α/SOX9.

Developing strategies to enhance cartilage differentiation in mesenchymal stem cells and preserve the extracellular matrix is crucial for successful cartilage tissue reconstruction. Hypoxia-inducible factor-1α (HIF-1α) plays a pivotal role in maintaining the extracellular matrix and chondrocyte phenotype, thus serving as a key regulator in chondral tissue engineering strategies. Recent studies have shown that Ubiquitin C-terminal hydrolase L1 (UCHL1) is involved in the deubiquitylation of HIF-1α. However, the regulatory role of UCHL1 in chondrogenic differentiation has not been investigated. In the present study, we initially validated the promotive effect of UCHL1 expression on chondrogenesis in adipose-derived stem cells (ADSCs). Subsequently, a hybrid baculovirus system was designed and employed to utilize three CRISPR activation (CRISPRa) systems, employing dead Cas9 (dCas9) from three distinct bacterial sources to target UCHL1. Then UCHL1 and HIF-1α inhibitor and siRNA targeting SRY-box transcription factor 9 (SOX9) were used to block UCHL1, HIF-1α and SOX9, respectively. Cartilage differentiation and chondrogenesis were measured by qRT-PCR, immunofluorescence and histological staining. We observed that the CRISPRa system derived from Staphylococcus aureus exhibited superior efficiency in activating UCHL1 compared to the commonly used the CRISPRa system derived from Streptococcus pyogenes. Furthermore, the duration of activation was extended by utilizing the Cre/loxP-based hybrid baculovirus. Moreover, our findings show that UCHL1 enhances SOX9 expression by regulating the stability and localization of HIF-1α, which promotes cartilage production in ADSCs. These findings suggest that activating UCHL1 using the CRISPRa system holds significant potential for applications in cartilage regeneration.

Cardiovascular abnormalities of long-COVID syndrome: Pathogenic basis and potential strategy for treatment and rehabilitation.

Cardiac injury and sustained cardiovascular abnormalities in long-COVID syndrome, i.e. post-acute sequelae of coronavirus disease 2019 (COVID-19) have emerged as a debilitating health burden that has posed challenges for management of pre-existing cardiovascular conditions and other associated chronic comorbidities in the most vulnerable group of patients recovered from acute COVID-19. A clear and evidence-based guideline for treating cardiac issues of long-COVID syndrome is still lacking. In this review, we have summarized the common cardiac symptoms reported in the months after acute COVID-19 illness and further evaluated the possible pathogenic factors underlying the pathophysiology process of long-COVID. The mechanistic understanding of how Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) damages the heart and vasculatures is critical in developing targeted therapy and preventive measures for limiting the viral attacks. Despite the currently available therapeutic interventions, a considerable portion of patients recovered from severe COVID-19 have reported a reduced functional reserve due to deconditioning. Therefore, a rigorous and comprehensive cardiac rehabilitation program with individualized exercise protocols would be instrumental for the patients with long-COVID to regain the physical fitness levels comparable to their pre-illness baseline.

Hypoxia activates the hypoxia-inducible factor-1α/vascular endothelial growth factor pathway in a prostatic stromal cell line: A mechanism for the pathogenesis of benign prostatic hyperplasia.

Background: The development of benign prostatic hyperplasia (BPH) is closely related to hypoxia in the prostatic stroma, and the hypoxia-inducible factor-1α/vascular endothelial growth factor (HIF-1α/VEGF) pathway has been shown to significantly activate in response to hypoxia. The underlying mechanism for activation of this pathway in the pathogenesis of BPH remains unclear. Materials and methods: We constructed HIF-1α overexpression and knockdown BPH stromal (WPMY-1) and epithelial (BPH-1) cell lines, which were cultured under different oxygen conditions (hypoxia, normoxia, and hypoxia + HIF-1α inhibitor). Quantitative real-time polymerase chain reaction (qPCR) and Western blotting were applied to detect the expression of the HIF-1α/VEGF pathway. Cell proliferation and apoptosis were analyzed by Cell Counting Kit-8 and flow cytometry. We used the miRWalk 2.0 database and Western blotting to predict the potential miRNA that selectively targets the HIF-1α/VEGF pathway, and verified the prediction by qPCR and dual-luciferase assays. Results: In a BPH stromal cell line (WPMY-1), the expression of VEGF was in accordance with HIF-1α levels, elevated in the overexpression cells and decreased in the knockdown cells. Hypoxia-induced HIF-1α overexpression, which could be reversed by a HIF-1α inhibitor. Moreover, the HIF-1α inhibitor significantly depressed cellular proliferation and promoted apoptosis in hypoxic conditions, assessed by Cell Counting Kit-8 and flow cytometry. However, in the BPH epithelial cell line (BPH-1), the expression level of HIF-1α did not influence the expression of VEGF. Finally, a potential miRNA, miR-17-5p, regulating the HIF-1α/VEGF pathway was predicted from the miRWalk 2.0 database and Western blotting, and verified by qPCR and dual-luciferase assay. Conclusions: In hypoxia, activation of the HIF-1α/VEGF pathway plays a crucial role in regulating cell proliferation in a BPH stromal cell line. Regulation by miR-17-5p may be the potential mechanism for the activation of this pathway. Regulation of this pathway may be involved in the pathogenesis of BPH.

Calcitriol/vitamin D receptor system alleviates PM2.5-induced human bronchial epithelial damage through upregulating mitochondrial bioenergetics in association with regulation of HIF-1α/PGC-1α signaling.

PM2.5 exposure causes lung injury by triggering oxidative stress, mitochondrial dysfunction, and modulating HIF-1α signaling. Calcitriol activates VDR, which regulates cellular homeostasis. This study evaluated the protective role of the calcitriol/VDR system in PM2.5-induced damage to BEAS-2B bronchial epithelial cells by reducing oxidative stress, upregulating mitochondrial bioenergetics, and downregulating HIF-1α. We found that the calcitriol/VDR system decreased ROS formation and restored mitochondrial bioenergetics in PM2.5-treated cells. This improvement correlated with reduced HIF-1α nuclear translocation and increased PGC-1α protein and mitochondrial gene expressions. This study is the first to suggest that targeting the calcitriol/VDR system could be a promising pharmacological strategy for mitigating PM2.5-induced lung epithelial damage by promoting mitochondrial bioenergetics and regulating PGC-1α and HIF-1α signaling.