Tea polyphenols nanoparticles integrated with microneedles multifunctionally boost 5-aminolevulinic acid photodynamic therapy for skin cancer.

5-aminolevulinic acid photodynamic therapy (ALA-PDT) is an emerging therapeutic strategy for skin cancer due to its noninvasiveness and high spatiotemporal selectivity. However, poor skin penetration, poor intratumoral delivery, the instability of aqueous ALA, and the tumor's inherent hypoxia microenvironment are major hurdles hindering the efficacy of ALA-PDT. Herein, we aim to address these challenges by using microneedles (MNs) to assist in delivering nanoparticles based on natural polymeric tea polyphenols (TP NPs) to self-assemble and load ALA (ALA@TP NPs). The TP NPs specifically increase cellular uptake of ALA by A375 and A431 cells and reduce mitochondrial membrane potential. Subsequently, the photosensitizer protoporphyrin IX derived from ALA accumulates in the tumor cells in a dose-dependent manner with TP NPs, generating reactive oxygen species to promote apoptosis and necrosis of A375 and A431 cells. Interestingly, TP NPs can ameliorate the tumor's inherent hypoxia microenvironment and rapid oxygen consumption during PDT by inhibiting hypoxia inducible factor-1α, thereby boosting reactive oxygen species (ROS) generation and enhancing ALA-PDT efficacy through a positive feedback loop. After ALA@TP NPs are loaded into MNs to fabricate ALA@TP NPs@MNs, the MNs enhance skin penetration and storage stability of ALA. Importantly, they exhibit remarkable antitumor efficacy in A375-induced melanoma and A431-induced squamous cell carcinoma with a reduced dose of ALA and reverse hypoxia in vivo. This study provides a facile and novel strategy that integrates MNs and green NPs of TP for addressing the bottlenecks of ALA-PDT and enhancing the ALA-PDT efficacy against skin cancers for future clinical translation.

Deferoxamine Accelerates Mandibular Condylar Neck Fracture Early Bone Healing by Promoting Type H Vessel Proliferation.

BACKGROUND: Condylar fractures (CFs) are a common type of maxillofacial trauma, especially in adolescents. Conservative treatment of CF avoids the possible complications of surgical intervention, but prolongs the patient's suffering because of the requirement for extended intermaxillary fixation. Therefore, the development of a new strategy to accelerate the rate of fracture healing to shorten the period of conservative treatment is of great clinical importance. OBJECTIVE: To investigate the potential of deferoxamine (DFO) in promoting the healing process of CF in adolescent mice. METHODS: Thirty-two 4-week-old male C57BL/6J mice were randomly assigned to four groups: vehicle + sham group, vehicle + CF group, DFO + sham group and DFO + CF group. After constructing the mandibular CF model, mandibular tissue samples were collected respectively at 1, 2 and 4 weeks postoperatively. Radiographic and histomorphometric analyses were employed to assess bone tissue healing and vascular formation. RESULTS: Deferoxamine was observed to promote the early bone healing of fracture, both radiologically and histomorphometrically. Furthermore, this enhancement of condylar neck fracture healing was attributed to the upregulation of the hypoxia-inducible factor-1α (HIF-1α) signalling pathway while facilitating the formation of type H vessels. In addition, DFO did not produce significant effects on the condylar neck between vehicle + sham and DFO + sham group. CONCLUSION: The application of the HIF-1α inducer DFO can enhance type H vessels expansion thereby accelerating condylar neck fracture healing.

Salidroside rescues hypoxic cardiomyocytes by regulating the EGLN1/HIF­1α pathway.

Myocardial infarction is characterized by oxygen deficiency caused by arterial flow restriction. Salidroside (SAL) protects against myocardial damage via antioxidant production and inhibition of apoptosis. The present study aimed to investigate potential rescue mechanism of SAL on hypoxic cardiomyocytes. H9C2 cardiomyocytes were divided into normoxia, hypoxia and hypoxia + SAL groups. The inhibitory rate of hypoxia and the optimal concentration and rescue effect of SAL were determined using Cell Counting Kit-8 assay and flow cytometry. Ca2+ concentration following hypoxia treatment and SAL intervention were detected by Fluo-4/acetoxymethyl. Tandem mass tag (TMT) proteomics was used to analyze the differential expression of hypoxia-associated proteins among the three groups. SAL exerted a protective effect on hypoxia-injured cardiomyocytes by enhancing aerobic metabolism during hypoxia and rescuing cardiomyocytes from hypoxic damage. SAL promoted cell proliferation, decreased apoptosis and increased Ca2+ levels in cell membranes of hypoxic cardiomyocytes. TMT proteomics results showed that the expression levels of intracellular hypoxia inducible factor-1 (HIF)-1α and Egl-9 family HIF 1 (EGLN1) in H9C2 cells were elevated under hypoxic conditions. However, SAL significantly decreased expression levels of HIF-1α and EGLN1. SAL inhibited mitochondrial calcium overload in hypoxic cardiomyocytes and attenuated expression of hypoxia-associated factors. SAL exerted its rescue effect on hypoxic cardiomyocytes through the EGLN1/HIF-1α pathway, thereby suppressing cardiomyocyte apoptosis, improving mitochondrial energy metabolism efficiency and rescuing cardiomyocytes from hypoxic injury.

Carbon monoxide as a negative feedback mechanism on HIF-1α in the progression of metabolic-associated fatty liver disease.

Metabolic-associated fatty liver disease (MAFLD) encompasses various chronic liver conditions, yet lacks approved drugs. Hypoxia-inducible factor-1α (HIF-1α) is pivotal in MAFLD development. Our prior research highlighted the efficacy of the nano-designed carbon monoxide (CO) donor, targeting HIF-1α in a mouse hepatic steatosis model. Given heme oxygenase-1 (HO-1, a major downstream molecule of HIF-1α) as the primary source of intrinsic CO, we hypothesized that upregulation of HO-1/CO, responsive to HIF-1α, forms a negative feedback loop regulating MAFLD progression. In this study, we explored the potential negative feedback mechanism of CO on HIF-1α and its downstream effects on MAFLD advancement. HIF-1α emerges early in hepatic steatosis induced by a high-fat (HF) diet, triggering increased HO-1 and inflammation. SMA/CORM2 effectively suppresses HIF-1α and steatosis progression when administered within the initial week of HF diet initiation but loses impact later. In adipose tissues, concurrent metabolic dysfunction and inflammation with HIF-1α activation suggest adipose tissue expansion initiates HF-induced steatosis, triggering hypoxia and liver inflammation. Notably, in an in vitro study using mouse hepatocytes treated with fatty acids, downregulating HO-1 intensified HIF-1α induction at moderate fatty acid concentrations. However, this effect diminished at high concentrations. These results suggest the HIF-1α-HO-1-CO axis as a feedback loop under physiological and mild pathological conditions. Excessive HIF-1α upregulation in pathological conditions overwhelms the CO feedback loop. Additional CO application effectively suppresses HIF-1α and disease progression, indicating potential application for MAFLD control.

Anticancer potential of isoalantolactone in testicular cancer: an analysis of cytotoxicity, apoptosis, and signaling pathways.

Testicular cancer, a highly prevalent malignancy among young adults, has witnessed an alarming rise in recent decades. This study delves into the therapeutic potential of isoalantolactone (IATL), a natural product extracted from Inula helenium and Inula racemosa, against testicular cancer. Employing MTT assays and flow cytometry, we observed a dose-dependent reduction in cell viability and induction of cell cycle arrest at sub-G1 phase with increasing IATL concentrations. Furthermore, Annexin V/PI dual staining revealed IATL-induced apoptosis. Human Apoptosis Array analysis demonstrated IATL's influence on HIF-1α and TNF R1 expression, implicating its role in cancer cell growth and death regulation. Next-generation sequencing (NGS) and pathway analysis highlighted the involvement of ferroptosis and HIF-1 signaling in IATL-mediated effects. Western blotting validated the downregulation of key proteins associated with apoptosis inhibition and activation, confirming IATL's potential as an anticancer agent. Moreover, IATL induced ferroptosis by modulating expression levels of GPX4, xCT, NRF2, and HO-1. Our findings shed light on IATL's multifaceted anticancer mechanisms, emphasizing its potential as a therapeutic candidate for testicular cancer.

[Corrigendum] Zoledronic acid sensitizes breast cancer cells to fulvestrant via ERK/HIF­1 pathway inhibition in vivo.

Following the publication of the above article, the authors drew to the Editor's attention that they had inadvertently used the same immunohistochemical image to show the experiments depicting the zoledronic acid­treated MCF­7/HIF­1α xenograft (the 'ZOL/MCF­7/hif' panel) and the fulvestrant­treated MCF­7/vector xenograft (the 'FUL/MCF­7/cdh' panel) in Fig. 3A on p. 5474. Subsequently, upon performing an independent review of the data in this paper, the Editorial Office pointed out to the authors that the same colony­formation assay image had been included in Fig. 1C to show the 'MCF­7/cdh­ZOL' and 'MCF­7/cdh­FUL' experiments. The authors re­examined their original data, and realized that inadvertent errors were made during the compilation of this pair of figures. The corrected versions of Figs. 1 and 3 are shown on the next two pages, now featuring the correct data for the 'MCF­7/cdh­ZOL' experiment in Fig. 1C and the 'ZOL/MCF­7/hif' experiment in Fig. 3A. All the authors agree with the publication of this corrigendum, and are grateful to the Editor of Molecular Medicine Reports for granting them the opportunity to publish this. Furthermore, they regret that these errors were introduced into the paper, even though they did not substantially alter any of the major conclusions reported in the paper, and apologize to the readership for any inconvenience caused. [Molecular Medicine Reports 17: 5470­5476, 2018; DOI: 10.3892/mmr.2018.8514].

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.

In Vitro Investigation of HIF-1α as a Therapeutic Target for Thyroid-Associated Ophthalmopathy.

Background: Thyroid-associated ophthalmopathy (TAO) involves tissue expansion and inflammation, potentially causing a hypoxic microenvironment. Hypoxia-inducible factor (HIF)-1α is crucial in fibrosis and adipogenesis, which are observed in TAO progression. We investigated the effects of hypoxia on orbital fibroblasts (OFs) in TAO, focusing on the role of HIF-1α in TAO progression. Methods: OFs were isolated from TAO and non-TAO patients (as controls). In addition to HIF-1α, adipogenic differentiation markers including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein (CEBP) were measured by Western blot, and phenotype changes were evaluated by Oil Red O staining under both normoxia and hypoxia. To elucidate the effect of HIF-1α inhibition, protein expression changes after HIF-1α inhibitor treatment were evaluated under normoxia and hypoxia. Results: TAO OFs exhibited significantly higher HIF-1α expression than non-TAO OFs, and the difference was more distinct under hypoxia than under normoxia. Oil Red O staining showed that adipogenic differentiation of TAO OFs was prominent under hypoxia. Hypoxic conditions increased the expression of adipogenic markers, namely PPARγ and CEBP, as well as HIF-1α in TAO OFs. Interleukin 6 levels also increased in response to hypoxia. The effect of hypoxia on adipogenesis was reduced at the protein level after HIF-1α inhibitor treatment, and this inhibitory effect was sustained even with IGF-1 stimulation in addition to hypoxia. Conclusion: Hypoxia induces tissue remodeling in TAO by stimulating adipogenesis through HIF-1α activation. These data could provide insights into new treatment strategies and the mechanisms of adipose tissue remodeling in TAO.

A Smart CA IX-Targeting and pH-Responsive Nano-Mixed Micelles for Delivery of FB15 with Superior Anti-Breast Cancer Efficacy.

Background: Breast cancer treatment has been a global puzzle, and targeted strategies based on the hypoxic tumor microenvironment (TME) have attracted extensive attention. As a signature transcription factor overexpressed in hypoxia tumor, hypoxia-inducible factor-1 (HIF-1) contribute to cancer progression. Compound 7-(3-(2-chloro-1H-benzo[d]1midazole-1-yl) propoxy)-2-(3,4,5-trime-thoxyphenyl)-4H-chromen-4-one, synthesized and named FB15 in our earlier research, a potential inhibitor of HIF-1α signaling pathway, has been proved a promising drug candidate for many kinds of cancer chemotherapy. However, the poor solubility and undesirable pharmacokinetics of FB15 leads to limited treatment efficacy of tumor, which ultimately restricts its potential clinical applications. Carbonic anhydrase IX (CAIX), a tumor cell transmembrane protein, was overexpressed in hypoxia tumor site. Acetazolamide (AZA), a highly selective ligand targeting CAIX, can be utilized to delivery FB15 to hypoxia tumor site. Methods: In this study, we prepared and characterized FB15 loaded nano-mixed micelles with the AZA conjugated poloxamer 188 (AZA-P188) and D-a-Tocopherol Polyethylene 1000 Glycol Succinate (TPGS), denoted as, AZA-P188/TPGS@FB15. Its delivery efficiency in vitro and in vivo was assessed by in vitro drug release, cytotoxicity assay, cellular uptake, and in vivo pharmacokinetics and fluorescence imaging. Finally, therapeutic effect of AZA-P188/TPGS@FB15 was investigated using a preclinical breast cancer subcutaneous graft model in vivo. Results: In vitro studies revealed that AZA-P188/TPGS@FB15 could efficiently target breast cancer cells mediated by CAIX receptor, trigger FB15 release in response to acidic condition, and enhance cellular uptake and cytotoxicity against breast cancer cells. The pharmacokinetic studies showed that FB15-loaded AZA-functionalized micelles exhibited significantly increased AUC0-t over free FB15. In vivo imaging demonstrated that AZA-functionalized micelles significantly increased the drug distribution in the tumor site. In vivo experiments confirmed that AZA-P188/TPGS@FB15 exhibited superior inhibition of tumor growth in nude mice with good biosafety. Conclusion: AZA-P188/TPGS@FB15 hold promise as a potentially effective therapeutic way for breast cancer. Its targeted delivery system utilizing AZA as a carrier shows potential for improving the efficacy of FB15 in cancer therapy.

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.

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.

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.

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.

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.

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.

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.