HIF-1α Expression Research Articles

Zhishi Xiebai Guizhi Decoction modulates hypoxia and lipid toxicity to alleviate pulmonary vascular remodeling of pulmonary hypertension in rats

BackgroundPulmonary hypertension (PH) is a severe cardio-pulmonary vascular disease, involves complex molecular mechanism especially during the pathological process of pulmonary vascular remodeling, brings a significant challenge to clinical treatment and thus resulting in high mortality rates. Classic Traditional Chinese medicine formula, Zhishi Xiebai Guizhi Decoction (ZXGD), holds therapeutic potential for PH. In present study, we sought to explore therapeutic potential of ZXGD against PH in rats.MethodsWe employed a combination methods of chemical profiling, echocardiographic, morphologic measurements, molecular biology, rats models and cultured pulmonary artery smooth muscle cells (PASMCs) to achieve this.ResultsEighteen compounds were precisely identified in ZXGD using UHPLC-QTOF-MS/MS. Our data demonstrated ZXGD could alleviate PH by reducing pulmonary artery pressure and alleviating pulmonary vascular remodeling in rats. Specifically, ZXGD was found to intervene in abnormal expansion of PASMCs, thereby attenuating pulmonary vascular remodeling. ZXGD was also observed to modulate expressions of HIF-1α, ROS, and Nrf2 to alleviate hypoxia and oxidative stress. Additionally, ZXGD significantly regulated disorders in pro-inflammatory cytokines, thus mitigating inflammation. Furthermore, ZXGD decreased levels of decadienyl-l-carnitine and LDL-C, while elevating HDL-C and lipid droplet counts, thereby reducing cholesterol and lipid toxicity and preserving mitochondrial function. Importantly, inhibition of HIF-1α reversed expression of key pathological triggers for pulmonary vascular remodeling. Neohesperidin and naringin in ZXGD extract were identified as the primary contributors to its pharmacological effects against PH.ConclusionAltogether, our study empirically explored therapeutic potential and pharmacological mechanisms of ZXGD in treating PH, offering a groundwork for the development of novel anti-PH drugs.Graphical

Morphological and functional observations of a novel model of retinal ischemia injury induced by bilateral carotid artery stenosis in mice.

To investigate the features of retinal ischemic injuries in a novel mouse model with bilateral carotid artery stenosis (BCAS). BCAS was induced with microcoil implantation in 6-8-week-old C57BL6 mice. Cerebral blood flow was monitored at 2, 7, and 28d postoperatively. Retinal morphological changes were evaluated by fundus photography and hematoxylin-eosin staining. Fluorescein fundus angiography (FFA) was performed to detect retinal vascular changes and circulation. The levels of apoptosis, activation of neurogliosis, and expression of hypoxia-inducible factor (HIF)-1α in the retina were assessed by Western blotting and immunofluorescence staining, followed by retinal ganglion cell (RGC) density detection. Additionally, electrophysiological examinations including photopic negative response (PhNR) was also performed. The mice demonstrated an initial rapid decrease in cerebral blood flow, followed by a 4-week recovery period after BCAS. The ratio of retinal artery and vein was decreased under fundus photography and FFA. Compared with the sham mice, BCAS mice showed thinner retinal thickness on day 28. Additionally, apoptosis was increased and RGC density was decreased mainly in peripheral retinal region. Neurogliosis was mainly located in the inner retinal layers, with a stable increase in HIF-1α expression. The dark-adapted electroretinogram showed a notable reduction in the a-, b-, and oscillatory potential (OP) wave amplitudes between days 2 and 7; this gradually recovered over the following 4wk. However, the b- and OP-wave amplitudes were still significantly decreased on PhNR examination on day 28. BCAS can result in relatively mild retinal ischemia injuries in mice, mainly in the inner layer and peripheral region. Our study provides a novel animal model for investigating retinal ischemic diseases.

Serpina3c Deficiency Promotes Obesity-related Hypertriglyceridemia and Inflammation through Activation of the Hif1α-glycolysis Axis in Adipose Tissue.

Adipose tissue dysfunction leads to abnormal lipid metabolism and high inflammation levels. This research aims to explore the role of Serpina3c, which is highly expressed in adipocytes, in obesity-related hypertriglyceridemia and metaflammation. Serpina3c global knockout (KO) mice, adipocyte-specific Serpina3c overexpressing mice, Serpina3c knockdown (KD) mice, and hypoxia-inducible factor 1 alpha(Hif1α) KD mice were fed a high-fat diet (HFD) for 16 weeks to generate obesity-related hypertriglyceridemia mice models. In the present study, Serpina3c KO mice and adipocyte-specific Serpina3c KD mice exhibited more severe obesity-related hypertriglyceridemia and metaflammation under HFD conditions. Serpina3c KO epididymal white adipose tissue (eWAT) primary stromal vascular fraction (SVF)-derived adipocytes exhibited higher lipid (triglyceride and non-esterified fatty acid) levels and higher fatty acid synthase expression after palmitic acid stimulation. Adipocyte-specific Serpina3c overexpression in KO mice prevented the KO group phenotype. The RNA-seq and in vitro validation revealed that Hif1α and the glycolysis pathways were upregulated in Serpina3c KD adipocytes, which were all validated by in vitro and in vivo reverse experiments. Co-immunoprecipitation (co-IP) provided evidence that Serpina3c bound nuclear factor erythroid 2-related factor 2 (Nrf2) to regulate Hif1α. Nrf2 KD reduced Hif1α and Fasn expression, decreased lipid content, and reduced the extracellular acidification rate in Serpina3c KO adipocytes. Metabolomics revealed that lactic acid (LD) levels in eWAT were responsible for adipose-associated macrophage inflammation. In summary,Serpina3c inhibits the Hif1α-glycolysis pathway and reduces de novo lipogenesis and LD secretion in adipocytes by binding to Nrf2, thereby improving HFD-induced lipid metabolism disorders and alleviating adipose tissue macrophage inflammation.

Human platelet lysate enhances small lipid droplet accumulation of human MSCs through MAPK phosphorylation

BackgroundHuman platelet lysate (hPL) has emerged as a promising serum substitute to enhance the self-renewal and multipotency of human mesenchymal stem cells (MSCs). Despite its potential, the specific biological mechanisms by which hPL influences MSC phenotypes remain inadequately understood.MethodsWe investigated the biological signaling activated by hPL in two common types of human MSCs: bone marrow-derived MSCs (BMSCs) and adipose-derived MSCs (ASCs). Cell adhesion and cell-matrix interaction were assessed through immunofluorescence staining and western blotting. The impact of hPL on lipid droplet formation in MSCs was thoroughly examined using oil red O/BODIPY staining, semi-quantitative analysis, and qRT-PCR. RNA sequencing and intracellular inhibition assays were also performed to elucidate the mechanisms by which hPL modulates MSC behavior.ResultsMSCs cultured in hPL medium demonstrated a reduction in cell size, spreading area, and vinculin puncta, while enhancing cell proliferation and lipid droplet accumulation compared to those cultured in control media. Notably, the lipid droplets in hPL-treated MSCs were significantly smaller than those in adipocyte-like cells differentiated from MSCs, highlighting hPL’s distinctive role in lipid production. Gene and protein expression profiles of hPL-treated MSCs differed from those in adipocyte-like cells. An angiogenic factor array revealed that hPL-MSCs had a distinct angiogenic factor profile compared to FBS-MSCs, with VEGF expression closely linked to HIF-1α expression. RNA-seq data identified approximately 1,900 differentially expressed genes (DEGs) between hPL-MSCs and FBS-MSCs, with enrichment in focal adhesion, ECM-receptor interaction, and PI3K-Akt/MAPK signaling pathways. Inhibition of MAPK phosphorylation significantly hampered lipid formation in hPL-MSCs, underscoring the pivotal role of MAPK signaling in hPL-driven adipogenesis.ConclusionThis study reveals the biological mechanisms by which hPL infleunces MSC behavior and differentiation, offering new insights into its potential application in regenerative medicine and tissue engineering.

Molecular Markers in Embryo Non-Development: Analysis of Gene Expressions (Ki-67, hTERT, HIF-1α) in Spent Embryo Culture Medium

An embryo culture medium is a specialized set of ambient conditions, technological equipment, and nutrients that embryos require to grow properly. We aimed to investigate the Ki-67, hTERT, and HIF-1α gene expression differences between developing and non-developing embryos in spent embryo culture medium. Ki-67, hTERT, and HIF-1α gene expressions were determined from the spent embryo culture medium containing developing and non-developing embryos of 20 normoresponder patients admitted to the Bahçeci Umut IVF Center. An increase in hTERT gene expression (p < 0.05) and a decrease in HIF-1α gene expression (p < 0.001) were observed in mediums of developing compared to the non-developing embryos. No difference was observed in Ki-67 gene expression (p > 0.05). While there was a correlation between Ki-67 and HIF-1α genes in the non-growing group (r < 0.01); no correlation was observed in the developing group (r > 0.05). Both normoresponder groups will be similar in terms of proliferation rate. The low HIF-1α expression that observed high telomerase activity in embryo development maintains continuity and avoids mechanisms that result in cell death. A molecular study of the embryo development in patients with similar characteristics may help to understand the pathogenesis of the disease and establish a diagnosis and specific treatment.

Pemafibrate Induces a Low Level of PPARα Agonist-Stimulated mRNA Expression of ANGPTL4 in ARPE19 Cell

To elucidate the unidentified roles of a selective peroxisome proliferator-activated receptor α (PPARα) agonist, pemafibrate (Pema), on the pathogenesis of retinal ischemic diseases (RID)s, the pharmacological effects of Pema on the retinal pigment epithelium (RPE), which is involved in the pathogenesis of RID, were compared with the pharmacological effects of the non-fibrate PPARα agonist GW7647 (GW). For this purpose, the human RPE cell line ARPE19 that was untreated (NT) or treated with Pema or GW was subjected to Seahorse cellular metabolic analysis and RNA sequencing analysis. Real-time cellular metabolic function analysis revealed that pharmacological effects of the PPARα agonist actions on essential metabolic functions in RPE cells were substantially different between Pema-treated cells and GW-treated cells. RNA sequencing analysis revealed the following differentially expressed genes (DEGs): (1) NT vs. Pema-treated cells, 37 substantially upregulated and 72 substantially downregulated DEGs; (2) NT vs. GW-treated cells, 32 substantially upregulated and 54 substantially downregulated DEGs; and (3) Pema vs. GW, 67 substantially upregulated and 51 markedly downregulated DEGs. Gene ontology (GO) analysis and ingenuity pathway analysis (IPA) showed several overlaps or differences in biological functions and pathways estimated by the DEGs between NT and Pema-treated cells and between NT and GW-treated cells, presumably due to common PPARα agonist actions or unspecific off-target effects to each. For further estimation, overlaps of DEGs among different pairs of comparisons (NT vs. Pema, NT vs. GW, and Pema vs. GW) were listed up. Angiopoietin-like 4 (ANGPTL4), which has been shown to cause deterioration of RID, was the only DEG identified as a common significantly upregulated DEG in all three pairs of comparisons, suggesting that ANGPTL4 was upregulated by the PPARα agonist action but that its levels were substantially lower in Pema-treated cells than in GW-treated cells. In qPCR analysis, such lower efficacy for upregulation of the mRNA expression of ANGPTL4 by Pema than by GW was confirmed, in addition to substantial upregulation of the mRNA expression of HIF1α by both agonists. However, different Pema and GW-induced effects on mRNA expression of HIF1α (Pema, no change; GW, significantly downregulated) and mRNA expression of ANGPTL4 (Pema, significantly upregulated; GW, significantly downregulated) were observed in HepG2 cells, a human hepatocyte cell line. The results of this study suggest that actions of the PPARα agonists Pema and GW are significantly organ-specific and that lower upregulation of mRNA expression of the DR-worsening factor ANGPTL4 by Pema than by GW in ARPE19 cells may minimize the risk for development of RID.

Investigating the Expression and Function of HIF-1α in Neocaridina davidi During Embryo Cleavage Stage

Neocaridina davidi, a member of Decapoda within Crustacea, stands out due to its petite stature, robust reproductive capabilities and short molting cycle. Consequently, it has emerged as a valuable experimental model for investigations spanning ecology, development, physiology, and toxicology. Despite the pivotal role of Hypoxia Inducible Factor-1α (HIF-1α) in diverse physiological processes like biological hypoxia stress, cellular growth, and stress resistance, its functionality in crustaceans remains underexplored. Moreover, the role and function of HIF-1α in crustaceans, especially in embryonic stages, have been insufficiently addressed. This study delves into the function of HIF-1α during embryonic development. Initially, the complete sequence of the HIF-1α gene was acquired. Notably, the expression of HIF-1α during the cleavage stage surpassed that of subsequent phases. Subsequently, dsRNAHIF-1α was introduced into sexually mature shrimp, revealing that the inhibitory impact of dsRNA on gene expression in the parental generation could be inherited by the offspring, exerting a specific gene silencing effect in the embryo. The consequences of silencing HIF-1α in embryos manifested as varying degrees of premature division termination, besides, the glycolysis in the embryos was also affected by HIF-1α suppression. These results provide data support for understanding the early embryonic development of crustaceans and HIF-1α functions within it.

Chitosan nanoparticles loaded with metformin and digoxin synergistically inhibit MCF-7 breast cancer cells through suppression of NOTCH-1 and HIF-1α gene expression

This study investigated the potential anticancer efficacy of co-treating the MCF-7 breast cancer cell line with chitosan nanoparticles (Cs NPs) loaded with metformin (Met) and digoxin (Dig). The Cs NPs had a size range of 90.6–148.7 nm and a zeta potential of +11.7 to +11.9 mV, indicating a positive surface charge. Notably, the Cs NPs demonstrated high encapsulation efficiencies, with values of 90.97 ± 5.14 % for Met and 92.12 ± 3.81 % for Dig, indicating effective loading of both drugs. The results revealed that the co-delivery of Met and Dig via Cs NPs significantly enhanced the anticancer efficacy, outperforming the treatment with individual free drugs or their combination, thereby demonstrating the potential benefits of nanoparticle-mediated co-administration. The drugs-loaded Cs NPs induced a marked increase in apoptosis in MCF-7 cells, with a cell death rate of 67.56 %, and significantly reduced mammosphere size by 48.08 %, thereby demonstrating a superior therapeutic efficacy compared to treatment with individual free drugs or their combination. Notably, the drug-loaded Cs NPs exhibited potent anti-migratory and anti-angiogenic effects, significantly inhibiting cell migration and new blood vessel formation, which may contribute to overcoming the inherent resistance of tumors to conventional therapies. Mechanistically, the co-treatment with drugs-loaded Cs NPs was found to downregulate the expression of NOTCH-1 and HIF-1α, two key transcription factors involved in tumor cell survival and adaptation, suggesting that their inhibition is a crucial component of the therapeutic efficacy of this treatment strategy. Collectively, the findings of this study suggest that the co-delivery of Met and Dig via chitosan Cs NPs represents a promising therapeutic strategy for breast cancer, as it effectively targets key pathways involved in tumor growth and progression, and underscores the potential of Cs NPs as a versatile platform for cancer therapy.

Neuronal HIF-1α expression in mediobasal hypothalamus affects glycolipid metabolism and body weight in mice fed with high-fat diet.

This study aimed to explore the interaction between the expression of neuronal HIF-1α in the mediobasal hypothalamus and food intake, glycolipid metabolism and body weight (BW) in mice consuming high-fat diet (HFD). In HIF-1αflox/flox mice, AAV-hSyn-GFP (NC group) or AAV-hSyn-cre-GFP (KD group) virus was injected into medial base of the hypothalamus. Frozen brain tissue sections confirmed the presence of the virus within the hypothalamus of mice after 28 days of AAV injection, including reporter signals within the arcuate nucleus, DMH and VMH. Consistently, the levels of HIF-1α mRNA in the ventral hypothalamus were significantly lower in the KD group compared to the NC group. These KD mice also demonstrated significantly increased food intake, body weight (BW), total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL) and serum insulin, combined with higher blood glucose, compared to NC animals. However, the levels of triglycerides and FFA were similar in both groups. Significant differences in p-Akt levels were not observed in the skeletal muscle, liver or epididymal fat in KD mice after insulin injection. In conclusion, the knockdown of HIF-1α within the neurons of mediobasal hypothalamus results in an increase in the appetite of mice fed with HFD, which in turn leads to a significant dysregulation of lipid and glucose metabolism and a corresponding increase in weight. Therefore, the neuronal HIF-1α expression in the mediobasal hypothalamus may be a critical regulator of glycolipid metabolism and body weight control when a high-fat diet is consumed.

Survival impact of hypoxia-inducible factor-1 alpha (HIF-1α) in Nucleophosmin1 mutated acute myeloid leukemia.

Nucleophosmin1 (NPM1) mutated acute myeloid leukemia (AML) without FLT3-ITD mutation is classified as a favorable risk AML which responds well to cytarabine therapy. Hypoxia-inducible factor-1 alpha (HIF-1α) promotes leukemic cell survival and maintains leukemic stem cell quiescence possibly contributing to cytarabine resistance. This study evaluated HIF-1α expression using immunohistochemistry in bone marrow of 29 newly diagnosed NPM1+FLT3-ITD- normal karyotype AML patients and analyzed its correlation with survival. All patients achieved complete remission after standard induction chemotherapy and proceeded to cytarabine consolidations. Positive HIF-1α staining with golgi body pattern and strong cytoplasmic HIF-1α expression was identified in 34.5% and 58.6% of patients, respectively. The expression of golgi body or strong cytoplasmic HIF-1α expression was related to increased relapse (p = 0.048) with significantly inferior relapse-free survival (RFS, p = 0.042). Using multivariate analysis, extramedullary disease at diagnosis was revealed as an independent prognostic factor for adverse RFS (hazard ratio [HR] 3.82; 95% confidence interval [CI] 1.26-11.55, p = 0.018), while golgi body or strong cytoplasmic HIF-1α expression showed a trend toward poor RFS (HR 3.56; 95% CI 1.00-12.69, p = 0.050). In summary, high HIF-1α expression is potentially a baseline prognostic biomarker for poor RFS and cytarabine resistance in NPM1+FLT3-ITD- AML. Further studies with the large number of patients are warranted.

LncRNA H19 Promotes Angiogenesis in Mouse Pulmonary Artery Endothelial Cells by Regulating the HIF-1α/VEGF Signaling Pathway.

Persistent pulmonary hypertension of the newborn (PPHN) is a syndrome of acute respiratory failure characterized by systemic hypoxemia and elevated pulmonary arterial pressure, which leads to pathological changes in pulmonary vascular remodeling and endothelial cell function. Long non-coding RNA (lncRNA) H19 has been shown to be involved in the regulation of arterial endothelial cell function, but its regulatory role in PPHN is not fully understood. In the present study, mouse pulmonary artery endothelial cells (MPAECs) were cultured in a hypoxic conditions. Subsequently, the regulatory function of lncRNA H19 on MPAECs was explored by constructing adenoviruses knocking down and overexpressing lncRNA H19. The results revealed that the hypoxic conditions could induce the proliferation and migration of MPAECs, as well as the high expression of lncRNA H19 in MPAECs. Knockdown of lncRNA H19 expression in MPAECs reversed hypoxic environment-induced functional changes in endothelial cells, whereas overexpression of lncRNA H19 further enhanced the proliferation and migration of MPAECs. In addition, lncRNA H19 upregulated the hypoxia-inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) pathway through sponge of miNA-20a-5p, which in turn promoted changes in endothelial cell function. LncRNA H19 may interfere with vascular remodeling in hypoxia-induced pulmonary hypertension by upregulating the expression of HIF-1α and VEGF in vascular endothelial cells.

Identification and verification of feature biomarkers associated with choline metabolism in sepsis-induced cardiomyopathy.

Background: Sepsis-induced cardiomyopathy (SIC), one of the most common complications of sepsis, seriously affects the prognosis of critically ill patients. Choline metabolism is an important biological process in the organism, and the mechanism of its interaction with SIC is unclear. The aim of this study was to reveal the choline metabolism genes (CMGs) associated with SIC and to provide effective targets for the treatment of SIC.Methods: Through a comprehensive analysis of the microarray dataset GSE79962 (comprising 20 SIC patients and 11 healthy controls) from the GEO database, suspected co-expression modules and differentially expressed genes (DEGs) in SIC were identified. Hub CMGs were obtained by intersecting choline metabolism database with DEGs and key model genes. Afterward, hub CMGs most significantly involved in prognosis were further analyzed for the verification of major pathways of enrichment analysis. Finally, the expression of hub CMGs in in vivo and in vitro SIC model was verified by immunohistochemistry staining and quantitative real-time polymerase chain reaction analysis (qPCR).Results: WGCNA identified 1 hub gene panel and 3867 hub genes, which were intersected with DEGs and CMGs to obtain the same 3 hub CMGs:HIF-1α, DGKD and PIK3R1. Only HIF-1α shows significant association with mortality (P = 0.009). Subsequent differential analysis based on the high and low HIF-1α expression yielded 63 DEGs and then they were uploaded into Cytoscape software to construct a protein-protein interaction (PPI) network and 6 hub genes with the highest priority were obtained (CISH, THBS1, IMP1, MYC, SOCS3 and VCAN). Finally, a multifactorial COX analysis revealed a significant correlation between HIF-1α and survival in SIC patients, which was further validated by in vitro and in vivo experiments.Conclusion: Our findings will provide new insights into the pathogenesis of SIC, and HIF-1α may have important applications as a potential biomarker for early detection and therapeutic intervention in SIC.

RO4929097 inhibits NICD3 to alleviate pulmonary hypertension via blocking Notch3/HIF-2α/FoxM1 signaling pathway.

Pulmonary hypertension (PH) is a condition in which the smooth muscle cells (SMCs) in the pulmonary arteries multiply excessively, causing the arteries to narrow. This can ultimately result in right heart failure and premature death. Notch3 is an important factor involved in pulmonary vascular remodeling in PH. RO4929097, as a γ-secretase inhibitor that inhibits Notch3 signaling pathway, may be a potential drug for the treatment of PH, but its feasibility and related mechanism of action need to be further investigated. In vitro modeling by hypoxic incubation of human pulmonary artery SMCs (HPASMCs). RO4929097 and plasmids including overexpression-NICD3 (oe-NICD3) and NICD3 small interfering RNA (siRNA) were used to alter the expression of NICD3, and HIF-2α inhibitor PT-2385 was used to alter the expression of HIF-2α. Western blot, EdU incorporation assay was used to investigate the alteration of NICD3, HIF-2α, FoxM1 protein expression, and cell proliferation. The severity of PH in rats was assessed by measuring the weight ratio of right ventricle (RV) to left ventricle (LV) and septum (S) (RV/[LV + S]) and hematoxylin-eosin (H&E) staining of lung tissues in a hypoxia-induced PH rat model. We first determined that hypoxia induction for 48h had the strongest induction of NICD3 and Notch3 in HPASMCs, and the strongest inhibition by 10μM RO4929097. Treatment of HPASMCs under hypoxic conditions with RO4929097 inhibited hypoxia-induced expression of NICD3, HIF-2α, FoxM1, and proliferation of HPASMCs. The inhibitory effect of RO4929097 was reversed after overexpression of NICD3 in HPASMCs. Further, we found that PT-2385 reversed the promotional effect of overexpression of NICD3 on the proliferation of HPASMCs. In vivo experiments, hypoxia-induced PH rats treated with RO4929097 showed a reduction in right ventricular hypertrophy index (RVHI) and a return to normal pulmonary artery morphology, indicating a reduction in the severity of PH. Our data suggest that RO4929097 regulates the Notch3/HIF-2α/FoxM1 signaling pathway by inhibiting the expression of NICD3, thereby inhibiting hypoxia-induced proliferation of HPASMCs. In vivo experiments also confirmed that RO4929097 could alleviate PH as a potential therapeutic strategy.

Effects of Atropine on Choroidal Hemodynamics and VEGFA and HIF-1α Expression in Form-Deprivation Myopia Guinea Pigs

Effects of Atropine on Choroidal Hemodynamics and VEGFA and HIF-1α Expression in Form-Deprivation Myopia Guinea Pigs

Licochalcone A loaded multifunctional chitosan hyaluronic acid hydrogel with antibacterial and inflammatory regulating effects to promote wound healing

The wound healing process is characterized by persistent infection and long-term inflammation. The licochalcone A (LicA) has the potential for skin wound healing and needs a good drug-loading platform to apply its antibacterial and anti-inflammatory effects. In this study, the LicA@chitosan (CS) -hyaluronic acid (HA) hydrogel with antibacterial and anti-inflammatory was developed for wound healing in mice. The SEM displayed that the hydrogel had an obvious porous structure and was very suitable to be used as a delivery carrier for LicA. The FTIR results suggested that the LicA can be effectively loaded in the CS-HA hydrogel. Variable strain scanning, frequency scanning and temperature scanning indicated that the LicA@CS-HA hydrogel can maintain the gel state. The LicA@CS-HA hydrogel had good biological safety, can inhibit the activity of Escherichia coli and Staphylococcus aureus, and can release LicA stably. The LicA@CS-HA hydrogel also has good adhesion and hemostatic properties. Finally, the LicA@CS-HA hydrogel significantly accelerated wound healing in mice skin injury model, and reduced inflammation and orderly collagen deposition were observed by HE and Masson staining. The immunohistochemistry indicated that the LicA@CS-HA hydrogel induced the positive expression of CD31, VEGF, and HIF-1α promoted neovascularization. The LicA@CS-HA hydrogel also down-regulated the expression of M1 macrophage markers CD86, IL-6, and TNF-α, and increased the expression of M2 macrophage markers CD206, IL-4, and IL-10 proteins. The molecular docking demonstrated that the target proteins had better binding activity to LicA. Collectively, the LicA@CS-HA hydrogel has broad application prospects in promoting wound healing.

Molecular response of canine testis to GnRH agonist: Insights into AR, HIF-1α, and HSPs expression during arrest and recovery of spermatogenesis.

Slow release gonadotropin releasing hormone (GnRH) agonist implants are frequently used for contraception in male dogs. Although the effects are fully reversible, there is still concern about the safety of the implant's mode of action. Addressing this, we investigated cellular stress and androgen receptor signaling during downregulation and recovery. Testicular tissues were sampled from dogs castrated at different time points after GnRH implant removal and compared with untreated controls. Androgen receptor (AR), hypoxia-inducible factor 1 (HIF1A) and heat shock proteins HSP72, HSP73, HSPA2, HSP90AA1 and HSP90AB1 were investigated by qPCR, and AR, HSP72, HSP73 and HSP90 immunohistochemically. While AR, HIF1A and HSP70 were upregulated at mRNA level, HSPA8, HSPA2 and HSP90AA1 expression were downregulated during spermatogenic arrest; HSP90AB1 expression did not change. Immunohistochemistry verified AR-expression in Sertoli, peritubular and Leydig cells, occasionally also in spermatogonia. Stress-inducible HSP72 was occasionally detected, while constitutive HSP73 and HSP90 were abundantly expressed by germ cells. Our results were similar with studies on seasonal breeders such as pine voles, geese, fish and soft-shelled turtles. Accordingly, GnRH implants did not impose additional cellular stress on testicular cells when compared with natural recrudescence. Since comparative data on HIF1α is scarce, we cannot draw conclusions about hypoxic conditions.

Von Hippel-Lindau deficiency protects the liver against ischemia/reperfusion injury through the regulation of hypoxia-inducible factor 1α and 2α.

Ischemia and reperfusion (I/R)-induced liver injury contributes to morbidity and mortality during hepatic surgery or liver transplantation. As a pivotal regulator of cancer and inflammation, the role of Von Hippel-Lindau (VHL) in hepatic I/R injury remains undetermined. We investigated the role of VHL in hepatic I/R injury by generating VHL conditional knockout (VHL-KO) mice. The downstream mechanisms of VHL were confirmed, and the role of HIF-2α in hepatic I/R injury was further investigated. In this study, we discovered that VHL upregulation was associated with hepatic I/R injury in a mouse model. VHL gene knockout (VHL-KO) and overexpression (Ad-VHL) mice demonstrated that VHL aggravated liver injury, increased inflammation, and accelerated cell death in hepatic I/R injury. The VHL protein (pVHL) regulates a crucial control mechanism by targeting HIFα subunits for ubiquitin-mediated degradation. In vitro and in vivo studies demonstrated that VHL interacted with and repressed hypoxia-inducible factor 1α (HIF-1α) and hypoxia-inducible factor 2α (HIF-2α) expression during hepatic I/R injury. Notably, the inhibition of HIF-1α or 2α, as well as the concurrent inhibition of HIF-1α and 2α, abrogated the protective effect of VHL-KO. The severe stabilization of HIF-1α or 2α, as well as the simultaneous overexpression of HIF-1α and 2α, compensated for the detrimental effect of VHL. Thus, we identified the VHL-HIF-1α/HIF-2α axis as an indispensable pathway that may be a novel target for mediating hepatic I/R injury.

METTL3-VISTA axis-based combination immunotherapy for APC truncation colorectal cancer

ObjectiveAlthough immune checkpoint blockade (ICB) therapy represents a bright spot in antitumor immunotherapy, its clinical benefits in colorectal cancer (CRC) are limited. Therefore, a new target for mediating CRC immunosuppression...

Oxygen-controllable injectable hydrogel alleviates intervertebral disc degeneration by balancing extracellular matrix metabolism

Nucleus pulposus (NP) cells, situated at the core of intervertebral discs, have acclimated to a hypoxic environment, orchestrating the equilibrium of extracellular matrix metabolism (ECM) under the regulatory influence of hypoxia inducible factor-1α (HIF-1α). Neovascularization and increased oxygen content pose a threat, triggering ECM degradation and intervertebral disc degeneration (IVDD). To address this, our study devised an oxygen-controllable strategy, introducing laccase into an injectable and ultrasound-responsive gelatin/agarose hydrogel. Laccase-mediated reactions were employed to deplete oxygen, establishing a hypoxic microenvironment that upregulated HIF-1α expression. The activation of hypoxia-inducible factors significantly enhanced the expression of aggrecan and collagen II, concurrently suppressing Matrix metalloproteinases (MMP13) and A Disintegrin and Metalloproteinase with Thrombospondin motifs (ADAMTS5) levels, thereby restoring the equilibrium of ECM metabolism. Simultaneously, the hydrogel facilitated the recruitment of stem cells into the NP through the controlled release of ATI2341, activating C-X-C chemokine receptor type 4 (CXCR4). Moreover, ultrasound amplification enhanced ATI2341 release, promoting the migration of NP stem cells. The hydrogel's efficacy in mitigating metabolic imbalances and inhibiting IVDD progression was substantiated in a rat puncture IVDD model through hydrogel injection into the discs. In conclusion, this hypoxia-inducible hydrogel, responsive to thermal stimuli from ultrasound, presents a promising avenue for IVDD treatment.

173 Constitutive HIF-1α expression in the epidermis fuels proliferation and is essential for effective barrier formation

173 Constitutive HIF-1α expression in the epidermis fuels proliferation and is essential for effective barrier formation