Inhibition Of HIF-1α Expression Research Articles

Hypoxia-Inducible Factor-1α Regulates High Phosphate-Induced Vascular Calcification via Type III Sodium-Dependent Phosphate Cotransporter 1.

Vascular calcification (VC) has a high incidence in patients with chronic kidney disease, which is a worldwide public health problem and presents a heavy burden to society. Hypoxia-inducible factor (HIF)-1α, the active subunit of HIF-1, has been reported to play a vital role in high phosphate-induced VC. However, the underlying mechanism is still undetermined, and effective treatment is unavailable. In the present study, human aortic smooth muscle cells (HASMCs) were cultured under normal or high phosphate media conditions. HIF-1α small interfering RNA and overexpression plasmids were employed to regulate HIF-1α expression. Phosphonoformic acid was employed to restrain the function of type III sodium-dependent phosphate cotransporter 1 (Pit-1). The expression levels of HIF-1α, Pit-1, runt-related transcription factor 2 (Runx2), and smooth muscle 22 alpha (SM22α) were evaluated, and the calcium contents were also examined. Cell growth was assessed using an MTT assay. High phosphate stimulation caused an upregulation in HIF-1α and Pit-1 expression levels and induced calcium depositions in HASMCs. Upregulation of Runx2 expression accompanied by downregulation of SM22α expression was observed in the high phosphate group. Following the suppression of HIF-1α expression, there was a concomitant attenuation in Pit-1 expression, calcium deposition, the alteration of phenotypic transition marker genes, and vice versa. The most serious calcium deposition was noted in HASMCs cultured under high phosphate conditions which were pretreated with a HIF-1α overexpression plasmid. However, when the biological functions of Pit-1 were restrained, the putative serious calcium deposition was not formed even in HASMCs transfected with a HIF-1α overexpression plasmid. The findings confirmed that HIF-1α regulated Pit-1 expression and exerted its pro-calcifying effect through Pit-1, which identified HIF-1α and Pit-1 as therapeutic targets for high phosphate-induced VC.

Metformin suppresses hypoxia-inducible factor-1α expression in cancer-associated fibroblasts to block tumor-stromal cross-talk in breast cancer

To investigate the mechanism of metformin for regulating tumor-stromal cell cross-talk in breast cancer. Tumor associated fibroblasts (CAFs) co-cultured with breast cancer cells were treated with metformin, and the changes in expressions of hypoxia-inducible factor-1α (HIF-1α), p-AMPK, stroma-derived factor-1 (SDF-1) and interleukin-8 (IL-8) in the CAFs were detected using ELISA, RT-qPCR or Western blotting; Transwell assay was used to evaluate the invasiveness of the tumor cells and its changes following treatment with exogenous SDF-1, IL-8 and TGF-β1. The effects of HIF-1α shRNA or overexpression plasmid, AMPK shRNA, and treatment with OG (a proline hydroxylase inhibitor) or 2-OXO (a proline hydroxylase activator) were examined on p-AMPK, HIF-1α, SDF-1 and IL-8 expressions and invasiveness of the CAFs. Metformin treatment significantly increased the expression levels of p-AMPK, SDF-1 and IL-8 (P<0.05) and decreased HIF-1α expression (P<0.05) without affecting AMPK expression level (P>0.05) in the CAFs. The invasion ability of metformintreated breast cancer cells was significantly decreased (P<0.05). Exogenous SDF-1 and IL-8, HIF-1α overexpression, and OGinduced upregulation of HIF-1α all significantly attenuated the inhibitory effects of metformin on breast cancer cell invasion (P<0.05) and HIF-1α, SDF-1 and IL-8 expressions in CAFs (P<0.05). Transfection with HIF-1α shRNA or treatment with 2-OXO significantly decreased the invasiveness of breast cancer cells (P<0.05). P-AMPK knockdown significantly suppressed the inhibitory effect of metformin on HIF-1α expression in CAFs and on invasion of breast cancer cells (P<0.05). Treatment with TGF-β1 partially decreased the inhibitory effect of metformin on HIF-1α expression in CAFs and invasiveness of the breast cancer cells (P<0.05). Metformin suppresses HIF-1α expression in CAFs to block tumor-stromal cross talk in breast cancer.

Red blood membrane camouflaging Bismuth nanoflowers designed for radio-photothermal therapy in lung cancer

Radio-photothermal therapy is an effective modality for cancer treatment. To overcome the radio-resistance in the hypoxic microenvironment and improve the sensitivity of radiotherapy, metal nanoparticles, and radio-photothermal therapy are widely used in the research of improving the curative effect and reducing the side effects of radiotherapy. Here, we developed red blood membrane camouflaging bismuth nanoflowers (RBCM-BNF) with outstanding physiological stability and biodegradability for lung tumours. In vitro data proved that the RBCM-BNF had the greatest cancer cell-killing ability combined with X-ray irradiation and photo-thermal treatment. Meanwhile, in vivo studies revealed that RBCM-BNF can alleviate the hypoxic microenvironment and promote tumour cell apoptosis by inhibiting HIF-1α expression and increasing caspase-3 expression. Therefore, RBCM-BNF had a good radio-sensitising effect and might be a promising biomimetic nanoplatform as a therapeutic target for cancer.

PDGFRβ-Antagonistic Affibody-Mediated Tumor-Targeted Tumor Necrosis Factor-Alpha for Enhanced Radiotherapy in Lung Cancer.

The morbidity and mortality of lung cancer are still the highest among all malignant tumors. Radiotherapy plays an important role in clinical treatment of lung cancer. However, the effect of radiotherapy is not ideal due to the radiation resistance of tumor tissues. Abnormalities in tumor vascular structure and function affect blood perfusion, and oxygen transport is impeded, making tumor microenvironment hypoxic. Tumor hypoxia is the major cause of radiotherapy resistance. By promoting tumor vessel normalization and enhancing vascular transport function, tumor hypoxia can be relieved to reduce radiotherapy resistance and increase tumor radiotherapy sensitivity. In our previous study, a pericytes-targeted tumor necrosis factor alpha (named Z-TNFα) was first constructed and produced by genetically fusing the platelet-derived growth factor receptor β (PDGFRβ)-antagonistic affibody (ZPDGFRβ) to the TNFα, and the Z-TNFα induced normalization of tumor vessels and improved the delivery of doxorubicin, enhancing tumor chemotherapy. In this study, the tumor vessel normalization effect of Z-TNFα in lung cancer was further clarified. Moreover, the tumor hypoxia improvement and radiosensitizing effect of Z-TNFα were emphatically explored in vivo. Inspiringly, Z-TNFα specifically accumulated in Lewis lung carcinoma (LLC) tumor graft and relieved tumor hypoxia as well as inhibited HIF-1α expression. As expected, Z-TNFα significantly increased the effect of radiotherapy in mice bearing LLC tumor graft. In conclusion, these results demonstrated that Z-TNFα is also a promising radiosensitizer for lung cancer radiotherapy.

MicroRNA-18a regulates the Pyroptosis, Apoptosis, and Necroptosis (PANoptosis) of osteoblasts induced by tumor necrosis factor-α via hypoxia-inducible factor-1α

BackgroundTumor necrosis factor-α (TNF-α) is involved in inflammatory responses and promotes cell death and the inhibition of osteogenic differentiation. MicroRNA (miRNA) plays a crucial role in the infected bone diseases, however, the biological role of miRNAs in inflammation-induced impaired osteogenic differentiation remains unclear. This study aimed to explore the role of miRNA-18a-5p (miR-18a) in regulating PANoptosis and osteogenic differentiation in an inflammatory environment via hypoxia-inducible factor-1α (HIF1-α). MethodsThe expression of miR-18a in MC3T3-E1 cells was analyzed using quantitative reverse transcription-polymerase chain reaction in an inflammatory environment induced by TNF-α. The expression of HIF1-α and NLRP3 in LV-miR-18a or sh-miR-18a cells was analyzed using western blotting. Fluorescence imaging for cell death, flow cytometry, and alkaline phosphatase activity analysis were used to analyze the role of miR-18a in TNF-α-induced PANoptosis and the inhibition of osteogenic differentiation. An animal model of infectious bone defect was established to validate the regulatory role of miR-18a in an inflammatory environment. ResultsThe expression of miRNA-18a in the MC3T3-E1 cell line was significantly lower under TNF-α stimulation than in the normal environment. miR-18a significantly inhibited the expression of HIF1-α and NLRP3, and inhibition of HIF1-α expression further inhibited NLRP3 expression. Furthermore, inhibition of miR-18a expression promoted the TNF-α-induced PANoptosis and inhibition of osteogenic differentiation, whereas miR-18a overexpression and the inhibition of both HIF1-α and NLRP3 reduced the effects of TNF-α. These findings are consistent with those of the animal experiments. ConclusionmiRNA-18a negatively affects HIF1-α/NLRP3 expression, inhibits inflammation-induced PANoptosis, and impairs osteogenic differentiation. Thus, it is a potential therapeutic candidate for developing anti-inflammatory strategies for infected bone diseases.

Astragaloside IV-induced BMSC exosomes promote neovascularization and protect cardiac function in myocardial infarction mice via the miR-411/HIF-1α axis

This study focused on investigating the mechanism of the astragaloside IV-induced bone marrow mesenchymal stem cell exosome (AS-IV-MSC-exo)/microRNA(miR)-411/HIF-1α axis in affecting vascular neovascularization and protecting cardiac function in myocardial infarction (MI) mice. Exosomes (MSC-exo and AS-IV-MSC-exo) were separated by differential centrifugation and then characterized. MI mouse models were established by left anterior descending coronary artery ligation. Echocardiography was used to evaluate cardiac function. HE staining and Masson staining were performed to observe myocardial histopathology. Capillary density in the myocardium via immunohistochemistry and quantified the expression of vascular endothelial growth factor (VEGF) via RT-qPCR. The expression of miR-411 and HIF-1α was tested by RT-qPCR and western blot and the targeting relationship of miR-411 and HIF-1α was verified by bioinformatics website and dual luciferase reporter gene assay. Exosomes with lipid bi-layer membrane structure, expressing exosomal surface marker proteins, and being taken up by cardiomyocytes could be successfully isolated utilizing ultracentrifugation. Intramyocardial injection of MSC-exo could restore cardiac function, decrease myocardial pathological changes and collagen deposition, and promote neovascularization in MI mice; the effect of AS-IV-MSC-exo was more significant. The ability of AS-IV-MSC-exo to restore cardiac function, lower myocardial pathological changes and collagen deposition, and promote neovascularization in MI mice was diminished when miR-411 expression in AS-IV-MSC-exo was reduced. Mechanistically, miR-411 was found to target and inhibit HIF-1α expression. Overexpression of HIF-1α impaired the impact of AS-IV-MSC-exo on improving cardiac function and promoting neovascularization in MI mice. AS-IV-MSC-exo improves cardiac function and promoted neovascularization via the miR-411/HIF-1α axis, thereby ameliorating MI.

Harmine ameliorates steroid-induced osteonecrosis of the femoral head by modulating metabolism and ferroptosis via HIF1-α

Steroid-induced osteonecrosis of the femoral head (SONFH) often leads to disability in the terminal stage, and there are still no effective drugs for prevention. Harmine (Hm), which is extracted from Peganum harmala L., is a β-carboline alkaloid with a number of biological and pharmacological properties. In this study, we discovered the protective effect of Hm on SONFH in rats. In vitro studies showed that Hm could ameliorate oxidative stress and facilitate osteogenic differentiation in bone mesenchymal stem cells (BMSCs), which play an important role in bone development and repair. Bioinformatics analysis revealed that ferroptosis and the HIF1-α pathway played an important role in SONFH pathogenesis. Mechanistically, Hm treatment alleviated ferroptosis by promoting HIF1-α expression in BMSCs. When shHif1a was used to inhibit HIF1-α expression, the protective effects of Hm disappeared. Meanwhile, we further found that Hm intervention promoted HIF1-α expression to increase GSH production and the GSH/GSSG ratio, which further promoted the scavenging of free radicals. In summary, Hm may be a promising candidate for the treatment of SONFH.

METFORMIN MITIGATES SEPSIS-ASSOCIATED PULMONARY FIBROSIS BY PROMOTING AMPK ACTIVATION AND INHIBITING HIF-1α-INDUCED AEROBIC GLYCOLYSIS.

Recent research has revealed that aerobic glycolysis has a strong correlation with sepsis-associated pulmonary fibrosis (PF). However, at present, the mechanism and pathogenesis remain unclear. We aimed to test the hypothesis that the adenosine monophosphate-activated protein kinase (AMPK) activation and suppression of hypoxia-inducible factor 1α (HIF-1α)-induced aerobic glycolysis play a central role in septic pulmonary fibrogenesis. Cellular experiments demonstrated that lipopolysaccharide increased fibroblast activation through AMPK inactivation, HIF-1α induction, alongside an augmentation of aerobic glycolysis. By contrast, the effects were reversed by AMPK activation or HIF-1α inhibition. In addition, pretreatment with metformin, which is an AMPK activator, suppresses HIF-1α expression and alleviates PF associated with sepsis, which is caused by aerobic glycolysis, in mice. Hypoxia-inducible factor 1α knockdown demonstrated similar protective effects in vivo . Our research implies that targeting AMPK activation and HIF-1α-induced aerobic glycolysis with metformin might be a practical and useful therapeutic alternative for sepsis-associated PF.

PI3K/AKT signaling activates HIF1α to modulate the biological effects of invasive breast cancer with microcalcification.

Microcalcification (MC) is a valuable diagnostic indicator of breast cancer, and it is reported to be associated with increased tumor aggressiveness and poor prognosis. Nevertheless, the exact potential molecular mechanism is not completely understood. Here, we find that the mineralized invasive breast cancer (IBC) cells not only increased their proliferation and migration, but also showed the characteristic of doxorubicin resistance. The PI3K/AKT signaling pathway is associated with the generation of calcification in IBC, and it activates the transcription and translation of its downstream hypoxia-inducible factor 1α (HIF1α). Knockdown of HIF1α protein significantly downregulated cell proliferation and migration while calcification persists. Meanwhile, calcified breast cancer cells restored sensitivity to doxorubicin because of suppressed HIF1α expression. In addition, we provide initial data on the underlying value of HIF1α as a biomarker of doxorubicin resistance. These findings provide a new direction for exploring microcalcifications in IBC.

B-364 Inhibition of Hypoxia-Inducible Factor-1a (HIF-1 a) Provides a Therapeutic Approach for Hepatocellular Carcinoma (HCC)

Abstract Background The most frequent type of primary liver cancer in adults is hepatocellular carcinoma (HCC) which is the third-highest cause of cancer-related death worldwide. Globally, people die from liver cancer each year, with HCC accounting for around 90% of those deaths, making it a serious public health concern. Cirrhosis, hepatitis B, hepatitis C, and non-alcoholic fatty liver disease are all high-risk factors for HCC development. In addition, HCC is one of the most frequent solid tumors found in humans. Due to insufficient blood supply, these solid tumors usually are devoid of oxygen and nutrients. A reduction in oxygen concentration results in the formation of a hypoxic environment that downregulates the metabolic process and is fatal to cancer cells. To circumvent this barrier to growth, cancer cells produce hypoxia-inducible factor-1 (HIF-1), which alters their metabolic pathways and allows them to survive. HIF-1alpha (HIF-1α), a cytoplasmic subunit of HIF-1 can be overexpressed in hypoxic conditions. HCC cells cannot proliferate under hypoxia without a high level of HIF-1α expression, making it as a potential cancer treatment target. Using the LOPAC (Library of Pharmacologically Active Compounds) drug library, we have identified multiple drug molecules that inhibit the expression of HIF-1α. Methods We constructed specific SK-HEP-1 cells, a human liver cancer cell line, expressing the luciferase reporter gene under the promoter of HIF-1α. By using the cells, we screened the (LOPAC) library. Other bioanalytical methods were used to confirm and analyze identified candidates. Results We successfully identified several compounds that are able to inhibit HIF-1α expression by using luciferase activity assays and Western blot analysis (WB). Further investigation was conducted to determine the molecular mechanism and function for one of the drug candidates, termed as UZ-1, in inhibiting HIF-1α in HCC by using the MTT assay and WB. UZ-1, an antirheumatic agent, showed a strong inhibitory effect on the expression of HIF-1α in SK-HEP-1 cells. In addition, it suppressed the signaling pathways associated with HIF-1α, leading to the apoptosis of HCC cells. Conclusion The UZ-1 molecule inhibits HIF-1α expression, as a result, and displays anticancer function in HCC cells through inducing apoptosis. Our result suggests that UZ-1 may be a potential drug candidate for the treatment of HCC.

Novel 4-aminoquinoline analogstargeting the HIF-1α signaling pathway.

Background: The aminoquinoline core exhibits versatile pharmacological properties, particularly in the area of anticancer activity. This study was designed to investigate the potential of the 4-aminoquinoline scaffold in the development of anticancer agents by targeting the HIF-1α signaling pathway. Methodology: The authors synthesized multiple derivatives of 4-aminoquinoline containing heterocyclic rings by a microwave reactorand assessed the cytotoxicity and inhibitory effects of these derivatives on the HIF-1α signaling pathway. Conclusion: Compound 3s was identified as the most promising HIF-1α inhibitor due to its exceptional antiproliferative effects, with IC50 values of 0.6and 53.3nM observed in MiaPaCa-2 and MDA-MB-231 cells, respectively. Furthermore, compound 3s was found to inhibit HIF-1α expression by decreasing the level of HIF-1α mRNA.

Induction of heme oxygenase-1 antagonizes PM2.5-induced pulmonary VEGFA expression through regulating HIF-1α.

Particulate matter (PM) 2.5 has long been regarded as a major risk factor of the respiratory system, which constitutes a threat to human health. Although the positive relationship between PM2.5 exposure and the development of respiratory diseases has been well established, limited studies investigate the intrinsic self-protection mechanisms against PM2.5-induced respiratory injuries. Excessive pulmonary inflammation served as a key pathogenic mechanism in PM2.5-induced airway dysfunction, and we have previously shown that PM2.5 induced the production of vascular endothelial growth factor A (VEGFA) in the bronchial epithelial cells, which subsequently led to pulmonary inflammatory responses. In the current study, we found that PM2.5 also concurrently induced the expression of the stress-responsive protein heme oxygenase-1 (HO-1) along with VEGFA in the bronchial epithelial cells both in vivo and in vitro. Importantly, knocking down of HO-1 expression significantly increased the synthesis and secretion of VEGFA; while overexpression of HO-1 showed the opposite effects, indicating that HO-1 induction can antagonize VEGFA production in the bronchial epithelial cells upon PM2.5 exposure. Mechanistically, HO-1 inhibited PM2.5-evoked VEGFA induction through modulating hypoxia-inducible factor 1 alpha (HIF-1α), which was the upstream transcriptional factor of VEGFA. More specifically, HO-1 could not only inhibit HIF-1α expression, but also suppress its transactivity. Taken together, our results suggested that HO-1 was an intrinsic protective factor against PM2.5-induced pulmonary VEGFA production with a mechanism relating to HIF-1α, thus providing a potential treatment strategy against PM2.5 triggered airway injuries.

STING regulates the transformation of the proinflammatory macrophage phenotype by HIF1A into autoimmune myocarditis.

Macrophages play an essential role in the pathogenesis of autoimmune myocarditis, but the molecular mechanism remains largely unknown. Here, the role of Stimulator of interferon gene (Sting) in autoimmune myocarditis was investigated. Six-week-old male BALB/c mice received two subcutaneous injections of 250μg α-MyHC peptide to establish experimental autoimmune myocarditis (EAM). With single-cell RNA sequencing analysis of cardiac immune (Cd45+) cells, Sting was found to initiate proinflammatory macrophage differentiation related to the acute EAM phase. Furthermore, proinflammatory macrophages contribute to the pathogenesis of EAM via hypoxia-inducible factor-1α (Hif1α). A higher expression level of Sting was detected in macrophages from myocarditis, which was positively correlated with Hif1α expression. Single-stranded DNA (ssDNA) accumulation in macrophages in myocarditis was observed in the hearts of EAM mice. Pharmacological blockade of STING by C-176 (a specific inhibitor) ameliorated the inflammatory response of EAM and reduced proinflammatory molecule (Ifn-β, Tnf-α, Ccl2, and F4/80) expression and Hif1α expression. In vitro studies revealed that ssDNA activated the expression of Sting; in turn, Sting accelerated proinflammatory molecule expression in mouse macrophages. Inhibition of Hif1α expression could reduce Sting-associated cardiac inflammation and proinflammatory molecule expression. In addition, the expression of STING and ssDNA accumulation in macrophages were observed in human autoimmune myocarditis heart samples. STING activated proinflammatory macrophage via HIF1A, promoting the development of autoimmune myocarditis. The STING signaling pathway might provide a novel mechanism of autoimmune myocarditis and serve as a potential therapeutic target for autoimmune myocarditis patients.

Luteolin attenuates lupus nephritis by regulating macrophage oxidative stress via HIF-1α pathway

Lupus nephritis (LN) is a serious complication of systemic lupus erythematosus (SLE) and a leading cause of mortality. Luteolin (LUT), a compound found in many vegetables, fruits, and Chinese herbal medicine, has been shown to possess anti-inflammatory, antioxidant, and immunosuppressive properties. However, the mechanisms underlying LUT's potential therapeutic effects on LN remain unclear. In this study, we investigated LUT's antagonistic effects on inflammation and oxidative stress using MRL/lpr mice and H2O2-treated macrophages (Raw264.7). Our results indicate that LUT can ameliorate pathological abnormalities and improve renal function in MRL/lpr mice by reducing renal oxidative stress and urinary protein levels. Furthermore, we found that the Hypoxia-inducible factor 1α (HIF-1α) pathway is involved in the process of LUT improving renal injury in lupus mice. Analysis of GEO data confirmed that HIF-1α expression is significantly elevated in the kidneys of LN patients, and our experiments conducted in vitro and in vivo indicate that infiltrating macrophages contribute to the elevated levels of HIF-1α expression in the kidney. By inhibiting HIF-1α expression and oxidative stress in macrophages, LUT can mitigate renal damage caused by infiltrating macrophages. In conclusion, our findings suggest that LUT may serve as a potential therapeutic option for the prevention and treatment of LN by suppressing HIF-1α expression in macrophages.

MiR-210 regulates lung adenocarcinoma by targeting HIF-1α

ObjectThis study sought to elucidate the role of microRNA-210 (miR-210) in the occurrence and development of lung adenocarcinoma (LUAD). MethodsThe levels of lncRNA miR-210HG and miR-210 in LUAD tissues and corresponding normal tissues were analyzed by real-time quantitative PCR. The expression of the anti-hypoxia factor hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were measured by qRT-PCR and Western blot. The target of miR-210 on HIF-1α was confirmed using TCGA, Western blot and luciferase reporter assay. The regulatory role of miR-210 on HIF-1α and VEGF in LUAD was investigated. The correlation of genes with clinical prognosis was analyzed using bioinformatics methods. The effect of miR-210 on LUAD cells was verified through apoptosis assays. ResultsThe expression of miR-210 and miR-210HG was significantly higher in LUAD tissues than in normal tissues. The expression of hypoxia-related indicators HIF-1α and VEGF was also significantly higher in LUAD tissues. MiR-210 suppressed HIF-1α expression by targeting site 113 of HIF-1α, thereby affecting VEGF expression. Overexpression of miR-210 inhibited HIF-1 expression by targeting the 113 site of HIF-1, thereby affecting VEGF expression. Conversely, inhibition of miR-210 resulted in a significant increase in HIF-1α and VEGF expression in LUAD cells. In TCGA-LUAD cohorts, the expression of VEGF-c and VEGF-d genes in LUAD tissues was significantly lower than in normal tissues, while overall survival was worse in LUAD patients with high expression of HIF-1α, VEGF-c and VEGF-d. Apoptosis was significantly lower in H1650 cells after miR-210 inhibition. ConclusionThis study reveals that miR-210 exerts an inhibitory effect on VEGF expression by down-regulating HIF-1α expression in LUAD. Conversely, inhibition of miR-210 significantly reduced H1650 apoptosis and led to worse patient survival by upregulating HIF-1α and VEGF. These results suggest that miR-210 could serve as a potential therapeutic target for the treatment of LUAD.

EGFR-antagonistic affibody-functionalized Pt-based nanozyme for enhanced tumor radiotherapy

Clinical radiotherapy (RT) is severely limited by hypoxic tumor microenvironment and a lack of targeting precision. Therefore, it is crucial to develop highly efficient radiosensitizers to enhance RT efficacy. Herein, a novel kind of epidermal growth factor receptor (EGFR)-antagonistic affibody-functionalized Pt-based nanozyme for RT sensitization to EGFR-positive tumors was developed. In this study, porous platinum nanoparticles (pPt NPs) featuring catalase (CAT)-like activity and strong radiation energy absorption ability were first synthesized. Then, a thin biomimetic polydopamine (PDA) layer was coated on pPt NPs to optimize its biocompatibility as well as provide a reactive surface. Finally, a dimeric EGFR-antagonistic affibody called ZEGFR expressed by the Escherichia coli (E. coli), was conjugated to pPt@PDA NPs (termed pPt@PDA-ZEGFR NPs) to precisely recognize EGFR-positive A431 tumors. Under the navigation of ZEGFR, superior tumor homing was achieved with these Pt-based nanozymes, which was ascribed to EGFR receptor-mediated endocytosis. As high-Z metal NPs exhibit an inherently strong ability to absorb radiation energy and catalyze endogenous H2O2 in tumors, the pPt@PDA-ZEGFR NPs demonstrated superb therapeutic efficacy; specifically, the NPs significantly inhibited HIF-1α expression and increased RT-induced DNA damage. Furthermore, the biosafety of these Pt-based nanozymes was good during short-term treatment. In summary, EGFR-antagonistic affibody-functionalized Pt-based nanozymes are promising radiosensitizers for the precise therapy of EGFR-positive tumors.

Mitochondrial fusion induced by transforming growth factor-β1 serves as a switch that governs the metabolic reprogramming during differentiation of regulatory T cells

Although metabolic reprogramming during the differentiation of regulatory T cells (Treg cells) has been extensively studied, the molecular switch to alter energy metabolism remains undefined. The present study explores the critical role of mitochondrial dynamics in the reprogramming and consequent generation of Treg cells. The results showed that during Treg cell differentiation, mitochondrial fusion but not fission led to elevation of oxygen consumption rate values, facilitation of metabolic reprogramming, and increase of number of Treg cells and expression of Foxp3 in vitro and in vivo. Mechanistically, mitochondrial fusion favored fatty acid oxidation but restricted glycolysis in Treg cells through down-regulating the expression of HIF-1α. Transforming growth factor-β1 (TGF-β1) played a crucial role in the induction of mitochondrial fusion, which activated Smad2/3, promoted the expression of PGC-1α and therefore facilitated the expression of mitochondrial fusion proteins. In conclusion, during Treg cell differentiation, TGF-β1 promotes PGC-1α-mediated mitochondrial fusion, which drives metabolic reprogramming from glycolysis to fatty acid oxidation via suppressing HIF-1α expression, and therefore favors the generation of Treg cells. The signals and proteins involved in mitochondrial fusion are potential therapeutic targets for Treg cell-related diseases.

Preventing ischemia-reperfusion injury by acousto-mechanical local oxygen delivery.

Ischemia-reperfusion (I/R) injury is a pathological process that causes vascular damage and dysfunction which increases recurrence and/or mortality in myocardial infarction, ischemic stroke, and organ transplantation. We hypothesized that ultrasound-stimulated oxygen-loaded microbubble (O2-MB) cavitation would enhance mechanical force on endothelium and simultaneously release oxygen locally at the targeted vessels. This cooperation between biomechanical and biochemical stimuli might modulate endothelial metabolism, providing a potential clinical approach to the prevention of I/R injury. Murine hindlimb and cardiac I/R models were used to demonstrate the feasibility of injury prevention by O2-MB cavitation. Increased mechanical force on endothelium induced eNOS-activated vasodilation and angiogenesis to prevent re-occlusion at the I/R vessels. Local oxygen therapy increased endothelial oxygenation that inhibited HIF-1α expression, increased ATP generation, and activated cyclin D1 for cell repair. Moreover, a decrease in interstitial H2O2 level reduced the expression of caspase3, NFκB, TNFα, and IL6, thus ameliorating inflammatory responses. O2-MB cavitation showed efficacy in maintaining cardiac function and preventing myocardial fibrosis after I/R. Finally, we present a potential pathway for the modulation of endothelial metabolism by O2-MB cavitation in relation to I/R injury, wound healing, and vascular bioeffects.

Coenzyme Q0 defeats NLRP3-mediated inflammation, EMT/metastasis, and Warburg effects by inhibiting HIF-1α expression in human triple-negative breast cancer cells.

Coenzyme Q0 (CoQ0) is a derivative quinone from Antrodia camphorata (AC) that exerts anticancer activities. This study examined the anticancer attributes of CoQ0 (0-4µM) on inhibited anti-EMT/metastasis and NLRP3 inflammasome, and altered Warburg effects via HIF-1α inhibition in triple-negative breast cancer (MDA-MB-231 and 468) cells. MTT assay, cell migration/invasion assays, Western blotting, immunofluorescence, metabolic reprogramming, and LC-ESI-MS were carried out to assess the therapy potential of CoQ0. CoQ0 inhibited HIF-1α expression and suppressed the NLRP3 inflammasome and ASC/caspase-1 expression, followed by downregulation of IL-1β and IL-18 expression in MDA-MB-231 and 468 cells. CoQ0 ameliorated cancer stem-like markers by decreasing CD44 and increasing CD24 expression. Notably, CoQ0 modulated EMT by upregulating the epithelial marker E-cadherin and downregulating the mesenchymal marker N-cadherin. CoQ0 inhibited glucose uptake and lactate accumulation. CoQ0 also inhibited HIF-1α downstream genes involved in glycolysis, such as HK-2, LDH-A, PDK-1, and PKM-2 enzymes. CoQ0 decreased extracellular acidification rate (ECAR), glycolysis, glycolytic capacity, and glycolytic reserve in MDA-MB-231 and 468 cells under normoxic and hypoxic (CoCl2) conditions. CoQ0 inhibited the glycolytic intermediates lactate, FBP, and 2/3-PG, and PEP levels. CoQ0 increased oxygen consumption rate (OCR), basal respiration, ATP production, maximal respiration, and spare capacity under normoxic and hypoxic (CoCl2) conditions. CoQ0 increased TCA cycle metabolites, such as citrate, isocitrate, and succinate. CoQ0 inhibited aerobic glycolysis and enhanced mitochondrial oxidative phosphorylation in TNBC cells. Under hypoxic conditions, CoQ0 also mitigated HIF-1α, GLUT1, glycolytic-related (HK-2, LDH-A, and PFK-1), and metastasis-related (E-cadherin, N-cadherin, and MMP-9) protein or mRNA expression in MDA-MB-231 and/or 468 cells. Under LPS/ATP stimulation, CoQ0 inhibited NLRP3 inflammasome/procaspase-1/IL-18 activation and NFκB/iNOS expression. CoQ0 also hindered LPS/ATP-stimulated tumor migration and downregulated LPS/ATP-stimulated N-cadherin and MMP-2/-9 expression. The present study revealed that suppression of HIF-1α expression caused by CoQ0 may contribute to inhibition of NLRP3-mediated inflammation, EMT/metastasis, and Warburg effects of triple-negative breast cancers.

Tetrastigma hemsleyanum Ethanolic Extract Inhibited the Growth of Nonsmall Cell Lung Cancer Cells by Suppressing Hypoxia-Inducible Factor-1α-Dependent Glycolysis and Angiogenesis

Background:The ethanolic extract of Tetrastigma hemsleyanum Diels et Gilg ( T hemsleyanum ethanolic extract [Te-EtOH]) showed positive effects against various tumors. However, there are few studies on the effects of Te-EtOH on nonsmall cell lung cancer (NSCLC). We attempted to examine the inhibiting effect of Te-EtOH on NSCLC cells and to elucidate the relevant mechanisms. Methods: A549 and H1299 cells were pretreated with Te-EtOH at different concentrations. Cell viability was analyzed by Cell Counting Kit-8, flow cytometry, and the 3-dimensional spheroid model; RNA-sequencing was also performed. Moreover, enzyme-linked immunosorbent assay and Western blot tests were performed to determine the metabolic capability, the expressions of energy metabolism-related proteins, and the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/hypoxia-inducible factor-1α (HIF-1α) pathway. Additionally, under hypoxic conditions, the ability of Te-EtOH to inhibit HIF-1α expression and the metabolic capability of NSCLC cells was tested. Results: Te-EtOH considerably repressed cell viability in a dose-dependent manner. RNA-sequencing revealed that Te-EtOH's inhibition of NSCLC cells activity was related to metabolism. In addition, Te-EtOH significantly inhibited glycolysis, and adenosine triphosphate and lactate accumulation in NSCLC cells. Furthermore, we found that Te-EtOH could block PI3K/AKT/HIF-1α pathway activation. Moreover, Te-EtOH significantly inhibited hypoxia-induced expression of HIF-1α, vascular endothelial growth factor, and metabolic capability. Conclusions: Our results suggested that Te-EtOH inhibited the growth of NSCLC cells by suppressing HIF-1α-dependent glycolysis and angiogenesis.