Downregulation Of HIF-1α Expression Research Articles

Plasmodium infection downregulates hypoxia‑inducible factor 1α expression to suppress the vascularization and tumorigenesis of liver cancer.

Liver cancer is characterized by hypervascularization. Anti-angiogenic agents may normalize the tumor vasculature and improve the efficacy of other treatments. The present study aims to investigate the anti-angiogenic effect of Plasmodium infection in a mouse model of implanted liver cancer cells. HepG2 cells were injected into the left liver lobe of nude mice as a model of in situ hepatic tumorigenesis. Plasmodium yoelii parasitized erythrocytes were administered in the animal model of liver cancer to introduce Plasmodium infection. The tumor growth and microvascular density were determined in the presence or absence of Plasmodium infection. The expression levels of hypoxia-inducible factor 1α (HIF-1α) and angiogenesis-related factors were evaluated using western blotting and reverse transcription-quantitative PCR analysis. The results demonstrated that Plasmodium infection suppressed tumor growth and vascularization in the mouse model of implanted HepG2 cells. Plasmodium parasites reduced the expression of pro-angiogenic factors (vascular endothelial growth factor A and angiopoietin 2), matrix metalloproteinases [(MMP)2 and MMP9] and inflammatory cytokines [tumor necrosis factor α, interleukin 6 (IL)-6) and IL-1β] in both hepatic and tumor tissues. HIF-1α was downregulated in both hepatic and tumor tissues upon Plasmodium infection, and HIF-1α overexpression rescued angiogenesis and tumor growth under the condition of Plasmodium infection. In conclusion, the results of the present study demonstrated the anti-angiogenic and anti-tumorigenic effects of Plasmodium infection on liver cancer through downregulating HIF-1α expression, indicating that Plasmodium parasites could be developed as an intervention strategy to restrain neo-angiogenesis in liver cancer.

Mulberroside A attenuates cigarette smoke-induced atherosclerosis in ApoE−/− mice via the Sirt1-HIF-1α axis

ObjectiveThis study investigated whether Mulberryside A (MBA) can attenuate cigarette smoke extract (CSE)-induced autophagy through a Sirt1-dependent pathway, thereby attenuating atherosclerosis in ApoE−/− mice. MethodsAfter treating human umbilical vein endothelial cells (HUVECs) with CSE and MBA, an MTT assay was performed to detect cell activity. Immunofluorescence and Western blotting were used to determine the expressions of autophagy-related proteins, Sirt1 and HIF-1α. Lentivirus and siRNA were used to construct overexpression and silencing (Sirt1 and HIF-1α) models. The in vivo inflammatory effects of CS on atherosclerosis in ApoE−/− mice were assessed by exposing mice to CS and MBA treatment. HE staining was used to detect atherosclerosis in mouse aortic tissue, and electron microscopy was used to detect autophagy of endothelial cells. ResultsCSE promoted autophagy in HUVECs, down-regulated Sirt1, and up-regulated HIF-1α expression. MBA treatment, overexpression of Sirt1, or silencing of HIF-1α attenuated CSE-induced autophagy, while MBA reversed CSE-induced downregulation of Sirt1 and upregulation of HIF-1α. However, overexpression of HIF-1α increased autophagy in HUVECs and attenuated the protective effect of Sirt1 overexpression or MBA on CSE-induced autophagy in HUVECs. In vivo experiments also demonstrated that MBA attenuates CS-induced aortic autophagy in ApoE−/− mice and up-regulates Sirt1 and downregulates HIF-1α expression. ConclusionsMBA attenuates CSE-induced autophagy through the Sirt1-HIF-1α axis, thereby attenuating atherosclerosis in ApoE−/− mice.

Self-Produced O2 CNs-Based Nanocarriers of DNA Hydrophobization Strategy Triggers Photodynamic and Mitochondrial-Derived Ferroptosis for Hepatocellular Carcinoma Combined Treatment.

Hypoxia can aggravate tumor occurrence, development, invasion, and metastasis, and greatly inhibit the photodynamic therapy (PDT) effect. Herein, carbon nitride (CNs)-based DNA and photosensitizer co-delivery systems (BPSCNs) with oxygen-producing functions are developed to address this problem. Selenide glucose (Seglu) is used as the dopant to prepare red/NIR-active CNs (SegluCNs). The tumor-targeting unit Bio-PEG2000 is utilized to construct BPSCNs nanoparticles through esterification reactions. Furthermore, DNA hydrophobization is realized via mixing P53 gene with a positively charged mitochondrial-targeted near-infrared (NIR) emitting photosensitizer (MTTPY), which is encapsulated in non-cationic BPSCNs for synergistic delivery. Ester bonds in BPSCNs@MTTPY-P53 complexes can be disrupted by lipase in the liver to facilitate P53 release, upregulated P53 expression, and promoted HIF-1α degradation in mitochondria. In addition, the oxygen produced by the complexes improved the hypoxic microenvironment of hepatocellular carcinoma (HCC), synergistically downregulated HIF-1α expression in mitochondria, promoted mitochondrial-derived ferroptosis and enhanced the PDT effect of the MTTPY unit. Both in vivo and in vitro experiments indicated that the transfected P53-DNA, produced O2 and ROS by these complexes synergistically led to mitochondrial-derived ferroptosis in hepatoma cells through the HIF-1α/SLC7A11 pathway, and completely avoiding PDT resistance caused by hypoxia, exerting a significant therapeutic role in HCC treatment.

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

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

G protein pathway suppressor 2 suppresses aerobic glycolysis through RACK1-mediated HIF-1α degradation in breast cancer

Aerobic glycolysis has been recognized as a hallmark of human cancer. G protein pathway suppressor 2 (GPS2) is a negative regulator of the G protein-MAPK pathway and a core subunit of the NCoR/SMRT transcriptional co-repressor complex. However, how its biological properties intersect with cellular metabolism in breast cancer (BC) development remains poorly elucidated. Here, we report that GPS2 is low expressed in BC tissues and negatively correlated with poor prognosis. Both in vitro and in vivo studies demonstrate that GPS2 suppresses malignant progression of BC. Moreover, GPS2 suppresses aerobic glycolysis in BC cells. Mechanistically, GPS2 destabilizes HIF-1α to reduce the transcription of its downstream glycolytic regulators (PGK1, PGAM1, ENO1, PKM2, LDHA, PDK1, PDK2, and PDK4), and then suppresses cellular aerobic glycolysis. Notably, receptor for activated C kinase 1 (RACK1) is identified as a key ubiquitin ligase for GPS2 to promote HIF-1α degradation. GPS2 stabilizes the binding of HIF-1α to RACK1 by directly binding to RACK1, resulting in polyubiquitination and instability of HIF-1α. Amino acid residues 70–92 aa of the GPS2 N-terminus bind RACK1. A 23-amino-acid-long GPS2-derived peptide was developed based on this N-terminal region, which promotes the interaction of RACK1 with HIF-1α, downregulates HIF-1α expression and significantly suppresses BC tumorigenesis in vitro and in vivo. In conclusion, our findings indicate that GPS2 decreases the stability of HIF-1α, which in turn suppresses aerobic glycolysis and tumorigenesis in BC, suggesting that targeting HIF-1α degradation and treating with peptides may be a promising approach to treat BC.

Aggregation-Induced Emission CN-Based Nanoparticles to Alleviate Hypoxic Liver Fibrosis via Triggering HSC Ferroptosis and Enhancing Photodynamic Therapy.

Hypoxia can lead to liver fibrosis and severely limits the efficacy of photodynamic therapy (PDT). Herein, carbon nitride (CN)-based hybrid nanoparticles (NPs) VPSGCNs@TSI for light-driven water splitting were utilized to solve this problem. CNs were doped with selenide glucose (Se-glu) to enhance their red/NIR region absorption. Then, vitamin A-poly(ethylene glycol) (VA-PEG) fragments and aggregation-induced emission (AIE) photosensitizers TSI were introduced into Se-glu-doped CN NPs (VPSGCNs) to construct VPSGCNs@TSI NPs. The introduction of VA-PEG fragments enhanced the targeting of the NPs to activated hepatic stellate cells (HSCs) and reduced their toxicity to ordinary liver cells. VPSGCN units could trigger water splitting to generate O2 under 660 nm laser irradiation, improve the hypoxic environment of the fibrosis site, downregulate HIF-1α expression, and activate HSC ferroptosis via the HIF-1α/SLC7A11 pathway. In addition, generated O2 could also increase the reactive oxygen species (ROS) production of TSI units in a hypoxic environment, thereby completely reversing hypoxia-triggered PDT resistance to enhance the PDT effect. The combination of water-splitting materials and photodynamic materials showed a 1 + 1 > 2 effect in increasing oxygen levels in liver fibrosis, promoting ferroptosis of activated HSCs and reversing PDT resistance caused by hypoxia.

Kreotoxin A administration inhibits hyperproliferation and inflammation of human ear keloid tissue and keloid-derived fibroblasts by downregulating HIF-1α expression

Keloids represent a prevalent dermal fibroproliferative disorder. They only affect humans and exhibit several tumor characteristics, such as excessive extracellular matrix (ECM) deposition, which usually occurs after skin injury. Kreotoxin type A (KTA) can inhibit the release of acetylcholine, and thereby inhibit the proliferation of keloid fibroblasts and reducing the formation of scars. Thus, KTA could be used as a therapeutic agent for keloids. However, the mechanisms of action of KTA in keloid treatment remain unclear. In this study, we aimed to explore the underlying mechanisms of action of KTA in human keloid treatment using human tissue and a cell-based model. Integrative microarray analysis revealed that hypoxia-inducible factor 1-alpha (HIF-1α) expression was frequently upregulated in hypertrophic scar and keloid tissues, whereas it was downregulated in the KTA-treated samples. Furthermore, KTA addition to keloid-derived fibroblasts (KDFs) reduced the growth rate and viability, induced apoptosis, and decreased inflammation and oxidative stress in KDFs. However, overexpression of HIF-1α restored cell number and survival, decreased apoptosis, and promoted inflammation and oxidative stress in KTA-treated KDFs. Furthermore, KTA treatment reduced the expression of ECM proteins, including vascular endothelial growth factor (VEGF), collagen I and III, whereas HIF-1α overexpression abolished the effects of KTA on KDFs. In conclusion, our findings provide novel insights into the mechanisms of action of KTA as a potential therapeutic agent for keloids via modulating HIF-1α expression.

LncRNA NEAT1 promotes angiogenesis of retinoblastoma cells through regulation of the miR-106a/HIF-1α axis

ObjectiveTo explore the role and mechanisms of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in angiogenesis of retinoblastoma (RB) cells. MethodsThis study investigated the roles of NEAT1 in RB progression. The RNA expression levels of NEAT1, miR-106a, and hypoxia-inducible factor-1alpha (HIF-1α) examined by quantitative reverse transcription polymerase chain reaction (RT-qPCR) were compared between RB cells and normal retinal pigment epithelial (RPE) cells. The binding sites between NEAT1 and miR-106a, and between miR-106a and HIF-1α were predicted by the TargetScan database and verified using the dual-luciferase reporter assay. By transfection of overexpression plasmid or shRNA of NEAT1, and/or treatment of miR-106a inhibitor or mimics, proliferation, invasion, and angiogenesis of RB cells (measured by the MTT assay, the Transwell assay, and the tube formation assay, respectively) were compared between groups. Group comparisons were analyzed using one-way analysis of variance (ANOVA), and Tukey's post-hoc test was employed for further statistical assessment. P-value less than 0.05 was considered statistically significant. ResultsThe RNA expression levels of NEAT1 and HIF-1α were upregulated in RB cells, whereas the expression level of miR-106a was downregulated compared with RPE cells. NEAT1 overexpression or miR-106a knockdown advanced proliferation, invasion, and tube formation of RB cells. As a target of NEAT1, miR-106a could sponge HIF-1α to downregulate HIF-1α expression level. Functional analyses indicated that miR-106a knockdown reversed the inhibitory effects of NEAT1 silencing on the proliferation, invasion, and tube formation of RB cells. Furthermore, miR-106a overexpression suppressed RB cell angiogenesis by downregulating HIF-1α expression level. ConclusionNEAT1 promoted proliferation, invasion, and angiogenesis of RB cells through upregulation of HIF-1α expression level by sponging miR-106a, demonstrating that NEAT1 may be a novel target for RB treatment.

Tanreqing suppresses the proliferation and migration of non-small cell lung cancer cells by mediating the inactivation of the HIF1α signaling pathway via exosomal circ-WDR78

Circular RNAs (circRNAs) have emerged as regulators of cancer progression, including non-small cell lung cancer (NSCLC). Tanreqing (TRQ), a traditional Chinese medicine, is used clinically for respiratory diseases. RT-qPCR quantified circ-WDR78 expression in NSCLC cells. Cell growth, apoptosis, invasion, and migration were assessed by functional assays. RNA-binding protein immunoprecipitation (RIP), luciferase reporter, and RNA pull-down assays determined the competing endogenous RNA (ceRNA) network of circ-WDR78. The interaction between HIF1α and CD274 (PD-L1) promoter was analyzed by chromatin immunoprecipitation (ChIP). Circ-WDR78 expression was up-regulated in TRQ-treated NSCLC cells. Functionally, circ-WDR78 exhibited anti-tumor effects in these cells. Additionally, circ-WDR78 could also induce reactive oxygen species (ROS) accumulation by down-regulating HIF1α expression, promoting autophagy. Mechanistically, circ-WDR78 destabilizes HIF1α via the miR-1265/FBXW8 axis. TRQ-induced exosome secretion from NSCLC cells inhibits PD-L1 expression, preventing immune escape. We found that TRQ-treated NSCLC cells secrete exosomes to transmit circ-WDR78 to untreated NSCLC cells, inhibiting the malignancy of recipient tumor cells. In conclusion, TRQ inhibits NSCLC cell proliferation, invasion, and migration through exosomal circ-WDR78-mediated inactivation of the HIF1α signaling pathway, providing potential insight into TRQ injection for NSCLC treatment. Communicated by Ramaswamy H. Sarma

Prepared MW-Immunosensitizers Precisely Release NO to Downregulate HIF-1α Expression and Enhance Immunogenic Cell Death.

Microwave thermotherapy (MWTT) has limited its application in the clinic due to its high rate of metastasis and recurrence after treatment. Nitric oxide (NO) is a gaseous molecule that can address the high metastasis and recurrence rates after MWTT by increasing thermal sensitivity, down-regulating the expression of hypoxia-inducible factor-1 (HIF-1), and inducing the immunogenic cell death (ICD). Therefore, GaMOF-Arg is designed, a gallium-based organic skeleton material derivative loaded with L-arginine (L-Arg), and coupled the mitochondria-targeting drug of triphenylphosphine (TPP) on its surface to obtain GaMOF-Arg-TPP (GAT) MW-immunosensitizers. When GAT MW-immunosensitizers are introduced into mice through the tail vein, reactive oxygen species (ROS) are generated and L-Arg is released under MW action. Then, L-Arg reacts with ROS to generate NO, which not only downregulates HIF-1 expression to improve tumor hypoxia exacerbated by MW, but also enhances immune responses by augment calreticulin (CRT) exposure, high mobility group box 1 (HMGB1) release, and T-cell proliferation to achieve prevention of tumor metastasis and recurrence. In addition, NO can induce mitochondria damage to increase their sensitivity to MWTT. This study provides a unique insight into the use of metal-organic framework MW-immunosensitizers to enhance tumor therapy and offers a new way to treat cancer efficiently.

Effect of gold nanocomposite bearing HIF-1α siRNA on radiotherapy in nasopharyngeal carcinoma cell

Purpose: To investigate the effect of gold nanocomposite carrying hypoxia-inducible factor-1α (HIF-1α) siRNA on radiosensitivity of nasopharynx cancer (NPC) cells.
 Methods: Gold nanocomposite (AuNRs-(PEI-PEG)/RGD) or (AuPPR) was first synthesized and its cytotoxicity was evaluated. Then, the expression of HIF-1α in hypoxic NPC cells was assessed. In addition, the radiation sensitivity of AuPPR bearing HIF-1α siRNA on the cells was examined under xray exposure.
 Result: Gold nanocomposite (AuPPR) carrying HIF-1α siRNA (AuPPR-HIF-1α siRNA) significantly down-regulated HIF-1α expression. Under irradiation treatment, AuPPR-HIF-1α siRNA significantly enhanced apoptosis of NPC cells by 33.76 ± 3.65 %, when compared to the control and simple AuPPR group (22.5 ± 4.16 %, p < 0.01). Furthermore, cell cycle was significantly blocked in the sub-G1 phase in AuPPR-HIF-1α siRNA radiotherapy groups, indicating severe cell damage.
 Conclusion: This study has demonstrated that AuPPR-HIF-1α siRNA is effective in improving the radiosensitivity of nasopharyngeal carcinoma cells under hypoxia, and therefore can potentially be used to improve the radiotherapy of this carcinoma

Chicoric acid ameliorates sepsis-induced cardiomyopathy via regulating macrophage metabolism reprogramming

BackgroundSepsis-related cardiac dysfunction is believed to be a primary cause of high morbidity and mortality. Metabolic reprogramming is closely linked to NLRP3 inflammasome activation and dysregulated glycolysis in activated macrophages, leading to inflammatory responses in septic cardiomyopathy. Succinate dehydrogenase (SDH) and succinate play critical roles in the progression of metabolic reprogramming in macrophages. Inhibition of SDH may be postulated as an effective strategy to attenuate macrophage activation and sepsis-induced cardiac injury. PurposeThis investigation was designed to examine the role of potential compounds that target SDH in septic cardiomyopathy and the underlying mechanisms involved. Methods/ResultsFrom a small molecule pool containing about 179 phenolic compounds, we found that chicoric acid (CA) had the strongest ability to inhibit SDH activity in macrophages. Lipopolysaccharide (LPS) exposure stimulated SDH activity, succinate accumulation and superoxide anion production, promoted mitochondrial dysfunction, and induced the expression of hypoxia-inducible factor-1α (HIF-1α) in macrophages, while CA ameliorated these changes. CA pretreatment reduced glycolysis by elevating the NAD+/NADH ratio in activated macrophages. In addition, CA promoted the dissociation of K(lysine) acetyltransferase 2A (KAT2A) from α-tubulin, and thus reducing α-tubulin acetylation, a critical event in the assembly and activation of NLRP3 inflammasome. Overexpression of KAT2A neutralized the effects of CA, indicating that CA inactivated NLRP3 inflammasome in a specific manner that depended on KAT2A inhibition. Importantly, CA protected the heart against endotoxin insult and improved sepsis-induced cardiac mitochondrial structure and function disruption. Collectively, CA downregulated HIF-1α expression via SDH inactivation and glycolysis downregulation in macrophages, leading to NLRP3 inflammasome inactivation and the improvement of sepsis-induced myocardial injury. ConclusionThese results highlight the therapeutic role of CA in the resolution of sepsis-induced cardiac inflammation.

Exploration of the molecular mechanism of tea polyphenols against pulmonary hypertension by integrative approach of network pharmacology, molecular docking, and experimental verification.

Pulmonary hypertension, a common complication of chronic obstructive pulmonary disease, is a major global health concern. Green tea is a popular beverage that is consumed all over the world. Green tea's active ingredients are epicatechin derivatives, also known as "polyphenols," which have anti-carcinogenic, anti-inflammatory, and antioxidant properties. This study aimed to explore the possible mechanism of green tea polyphenols in the treatment of pulmonary hypertension using network pharmacology, molecular docking, and experimental verification. A total of 316 potential green tea polyphenols-related targets were obtained from the PharmMapper, SwissTargetPrediction, and TargetNet databases. A total of 410 pulmonary hypertension-related targets were predicted by the CTD, DisGeNET, pharmkb, and GeneCards databases. Green tea polyphenols-related targets were hit by the 49 targets associated with pulmonary hypertension. AKT1 and HIF1-α were identified through the FDA drugs-target network and PPI network combined with GO functional annotation and KEGG pathway enrichment. Molecular docking results showed that green tea polyphenols had strong binding abilities to AKT1 and HIF1-α. In vitro experiments showed that green tea polyphenols inhibited the proliferation and migration of hypoxia stimulated pulmonary artery smooth muscle cells by decreasing AKT1 phosphorylation and downregulating HIF1α expression. Collectively, green tea polyphenols are promising phytochemicals against pulmonary hypertension.

Salvianolic acid A diminishes LDHA-driven aerobic glycolysis to restrain myofibroblasts activation and cardiac fibrosis via blocking Akt/GSK-3β/HIF-1α axis.

Myofibroblasts activation intensively contributes to cardiac fibrosis with undefined mechanism. Salvianolic acid A (SAA) is a phenolic component derived from Salvia miltiorrhiza with antifibrotic potency. This study aimed to interrogate the inhibitory effects and underlying mechanism of SAA on myofibroblasts activation and cardiac fibrosis. Antifibrotic effects of SAA were evaluated in mouse myocardial infarction (MI) model and in vitro myofibroblasts activation model. Metabolic regulatory effects and mechanism of SAA were determined using bioenergetic analysis and cross-validated by multiple metabolic inhibitors and siRNA or plasmid targeting Ldha. Finally, Akt/GSK-3β-related upstream regulatory mechanisms were investigated by immunoblot, q-PCR, and cross-validated by specific inhibitors. SAA inhibited cardiac fibroblasts-to-myofibroblasts transition, suppressed collage matrix proteins expression, and effectively attenuated MI-induced collagen deposition and cardiac fibrosis. SAA attenuated myofibroblasts activation and cardiac fibrosis by inhibiting LDHA-driven abnormal aerobic glycolysis. Mechanistically, SAA inhibited Akt/GSK-3β axis and downregulated HIF-1α expression by promoting its degradation via a noncanonical route, and therefore restrained HIF-1α-triggered Ldha gene expression. SAA is an effective component for treating cardiac fibrosis by diminishing LDHA-driven glycolysis during myofibroblasts activation. Targeting metabolism of myofibroblasts might occupy a potential therapeutic strategy for cardiac fibrosis.

Liangxue Jiedu formula improves imiquimod-induced psoriasiform dermatitis with circadian desynchrony by regulating Th17 cell differentiation based on network pharmacological analysis

Ethnopharmacological relevanceLiangxue Jiedu formula (LXJDF) is an effective traditional Chinese medicine (TCM) formula for treating psoriasis of blood-heat syndrome and has been used in clinics for decades. Aim of the studyThis study aimed to discover the mechanism of LXJDF in psoriasis and the circadian clock by network pharmacology and experimental studies. Materials and methodsThe compounds of LXJDF were obtained from the TCMSP and BATMAN-TCM databases. The genes related to psoriasis and circadian rhythm/clock were identified by the OMIM and GeneCards databases. Then, target genes were integrated by Venn and analyzed by the String, CytoNCA, DAVID (GO and KEGG) databases, and the network was constructed using Cytoscape. Mice were raised under light disturbance for fourteen days. On the eighth day, mouse dorsal skin was shaved and smeared with 62.5 mg 5% imiquimod at 8:00 (ZT0) for six successive days. Mice were randomly divided into the model, LXJDF-H (49.2 g/kg·bw), LXJDF-L (24.6 g/kg·bw), and positive drug (dexamethasone) groups. Other mice were smeared with Vaseline under the normal light cycle as the control. The drug of each group was administered at 10:00 (ZT2) and 22:00 (ZT14). The skin lesions were observed, and PASI was scored daily. HE and immunofluorescence were used to measure pathological morphology. Th17 cytokines in serum and skin were measured by flow cytometry and qPCR. Circadian clock gene and protein expression levels were determined by qPCR and Western blotting. ResultsWe found 34 potential targets of LXJDF in the treatment of psoriasis and circadian rhythm and confirmed their importance by topology analysis. KEGG pathway analysis revealed that the two major pathways were Th17 cell differentiation and the HIF-1 signaling pathway. At ZT2 and ZT14, LXJDF improved IMQ-induced light disturbance mouse skin lesions, including alleviating scales, erythema, and infiltration, reducing PASI, and inhibiting keratinocyte hyperproliferation and parakeratosis. LXJDF reduced IL-17A, IL-17F, TNF-α, and IL-6 in serum at ZT2 and increased IL-10 at ZT2 and ZT14. LXJDF downregulated the expression of IL-17A and IL-17F in skin. At ZT2, LXJDF significantly upregulated CLOCK and REV-ERBα expression and downregulated HIF-1α expression. At ZT14, LXJDF decreased HIF-1α and RORγt expression and significantly increased REV-ERBα expression. ConclusionLXJDF improves psoriasis dermatitis with circadian rhythm disorders by regulating Th17 cell differentiation.

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.

Photobiomodulation at 660nm promotes collagen synthesis via downregulation of HIF-1α expression without photodamage in human scleral fibroblasts in vitro in a hypoxic environment.

The increasing prevalence of myopia is a global public health issue. Because of the complexity of myopia pathogenesis, current control methods for myopia have great limitations. The aim of this study was to explore the effect of photobiomodulation (PBM) on human sclera fibroblasts (HSFs) under hypoxia, in the hope of providing new ideas for myopia prevention and control. Hypoxic cell model was established at 0, 6, 12, and 24h time points to simulate myopia microenvironment and explore the optimal time point. Control, hypoxia, hypoxia plus light, and normal plus light cell models were set up for the experiments, and cells were incubated for 24 or 48h after PBM (660nm, 5J/cm2), followed by evaluation of hypoxia-inducible factor 1α (HIF-1α) and collagen I a1 (COL1A1) proteins using Western blotting and immunofluorescence, and photo damage was detected by CCK-8, scratch test, and flow cytometry assays. We also used transfection technology to further elucidate the regulatory mechanism. The change of target proteins is most obvious when hypoxia lasts for 24h (p < 0.01). PBM at 660nm increased extracellular collagen content (p < 0.001) and downregulated expression of HIF-1α (p < 0.05). This treatment did not affect the migration and proliferation of cells (p > 0.05), and effectively inhibited apoptosis under hypoxia (p < 0.0001). After overexpression of HIF-1α, the effect of PBM was attenuated (p > 0.05). Photobiomodulation at 660nm promotes collagen synthesis via downregulation of HIF-1α expression without photodamage.

Autophagy inhibition and ferroptosis activation during atherosclerosis: Hypoxia-inducible factor 1α inhibitor PX-478 alleviates atherosclerosis by inducing autophagy and suppressing ferroptosis in macrophages

ObjectiveTo elucidate the key regulator responsible for autophagy and ferroptosis, and if specific pharmacological inhibitor of upregulated gene exerted the pro-autophagic and anti-ferroptotic effect on macrophage to alleviate the atherosclerosis. MethodsAutophagy and ferroptosis were evaluated in atherosclerotic lesions and THP-1 macrophages exposed to ox-LDL. Autophagy/ferroptosis-related differentially expressed genes (DEGs) in atherosclerosis were identified by bioinformatic analysis of GSE97210 dataset, and were validated in atherosclerotic cells and tissues. The efficacy and mechanism of pharmacological inhibition of the validated DEGs on alleviating atherosclerosis were explored in vivo and in vitro. ResultsAtherosclerotic lesions were characterized by autophagy inhibition and ferroptosis activation in macrophages. The crosslink between autophagy and ferroptosis were demonstrated. Ox-LDL induced THP-1 macrophage foam cell formation, autophagy dysfunction, and ferroptosis occurrence. Rapamycin ameliorated and, conversely, erastin deteriorated the effect of ox-LDL on THP-1 macrophages. Eleven autophagy/ferroptosis-related DEGs were identified in atherosclerosis vs. normal. The up-regulated expression of HIF-1α was verified in atherosclerotic lesions and THP-1 macrophages induced by ox-LDL. HIF-1α inhibitor PX-478 restored autophagy function, depressed ferroptosis, and reduced lipid accumulation in ox-LDL induced THP-1 macrophage. Autophagy inhibitor 3-MA obviously abrogated the pro-autophagic, anti-ferroptotic, and anti-atherosclerotic effects of PX-478. PX-478 treatment down-regulated HIF-1α expression and reduced atherosclerotic plaques in the mice model. ConclusionsAutophagy is inhibited, ferroptosis is activated, and crosslink occurs between autophagy and ferroptosis during atherosclerosis. HIF-1α, an upregulated DEG between atherosclerosis and normal, co-regulates autophagy and ferroptosis. HIF-1α inhibitor PX-478 attenuates foam cell formation and lessens atherosclerosis by enhancing autophagy and depressing ferroptosis in macrophages.

Oxygen-generating microparticles downregulate HIF-1α expression, increase cardiac contractility, and mitigate ischemic injury.

Myocardial hypoxia is the low oxygen tension in the heart tissue implicated in many diseases, including ischemia, cardiac dysfunction, or after heart procurement for transplantation. Oxygen-generating microparticles have recently emerged as a potential strategy for supplying oxygen to sustain cell survival, growth, and tissue functionality in hypoxia. Here, we prepared oxygen-generating microparticles with poly D,L-lactic-co-glycolic acid, and calcium peroxide (CPO), which yielded a continuous morphology capable of sustained oxygen release for up to 24h. We demonstrated that CPO microparticles increased primary rat cardiomyocyte metabolic activity while not affecting cell viability during hypoxia. Moreover, hypoxia-inducible factor (HIF)-1α, which is upregulated during hypoxia, can be downregulated by delivering oxygen using CPO microparticles. Single-cell traction force microscopy data demonstrated that the reduced energy generated by hypoxic cells could be restored using CPO microparticles. We engineered cardiac tissues that showed higher contractility in the presence of CPO microparticles compared to hypoxic cells. Finally, we observed reduced myocardial injuries in ex vivo rabbit hearts treated with CPO microparticles. In contrast, an acute early myocardial injury was observed for the hearts treated with control saline solution in hypoxia. In conclusion, CPO microparticles improved cell and tissue contractility and gene expression while reducing hypoxia-induced myocardial injuries in the heart. STATEMENT OF SIGNIFICANCE: Oxygen-releasing microparticles can reduce myocardial ischemia, allograft rejection, or irregular heartbeats after heart transplantation. Here we present biodegradable oxygen-releasing microparticles that are capable of sustained oxygen release for more than 24 hrs. We then studied the impact of sustained oxygen release from microparticles on gene expresseion and cardiac cell and tissue function. Previous studies have not measured cardiac tissue or cell mechanics during hypoxia, which is important for understanding proper cardiac function and beating. Using traction force microscopy and an engineered tissue-on-a-chip, we demonstrated that our oxygen-releasing microparticles improve cell and tissue contractility during hypoxia while downregulating the HIF-1α expression level. Finally, using the microparticles, we showed reduced myocardial injuries in rabbit heart tissue, confirming the potential of the particles to be used for organ transplantation or tissue engineering.

Hypoxia-ameliorated photothermal manganese dioxide nanoplatform for reversing doxorubicin resistance.

Drug resistance is a huge hurdle in tumor therapy. Tumor hypoxia contributes to chemotherapy resistance by inducing the hypoxia-inducible factor-1α (HIF-1α) pathway. To reduce tumor hypoxia, novel approaches have been devised, providing significant importance to reverse therapeutic resistance and improve the effectiveness of antitumor therapies. Herein, the nanosystem of bovine serum albumin (BSA)-templated manganese dioxide (MnO2) nanoparticles (BSA/MnO2 NPs) loaded with doxorubicin (DOX) (DOX-BSA/MnO2 NPs) developed in our previous report was further explored for their physicochemical properties and capacity to reverse DOX resistance because of their excellent photothermal and tumor microenvironment (TME) response effects. The DOX-BSA/MnO2 NPs showed good biocompatibility and hemocompatibility. Meanwhile, DOX-BSA/MnO2 NPs could greatly affect DOX pharmacokinetic properties, with prolonged circulation time and reduced cardiotoxicity, besides enhancing accumulation at tumor sites. DOX-BSA/MnO2 NPs can interact with H2O2 and H+ in TME to form oxygen and exhibit excellent photothermal effect to further alleviate hypoxia due to MnO2, reversing DOX resistance by down-regulating HIF-1α expression and significantly improving the antitumor efficiency in DOX-resistant human breast carcinoma cell line (MCF-7/ADR) tumor model. The hypoxia-ameliorated photothermal MnO2 platform is a promising strategy for revering DOX resistance.