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

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

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

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

Placental apoptosis increased by hypoxia inducible factor-1 stabilization is counteracted by leptin†.

During pregnancy, apoptosis is a physiological event critical in the remodeling and aging of the placenta. Increasing evidence has pointed toward the relevance of hypoxia as modulator of trophoblast cell death. Previous reports have shown that leptin, a placental cytokine, promotes cell survival in both cell culture and placental explant models. The aim of this work is to establish the role of leptin in apoptosis under hypoxic condition in trophoblast cells. In this study, we evaluated the effect of cobalt chloride, a hypoxia mimicking agent that stabilizes the expression of hypoxia-inducible factor-1 alpha, on Swan-71 and human placental explants. Hypoxia chamber was also used to generate 2% oxygen. Apoptosis was determined by the presence of apoptotic nucleus, fragmentation of DNA and Caspase-3 and PARP-1 cleavage. The pro-apoptotic proteins BAX, BID, BAD, and BAK and the anti-apoptotic effectors BCL-2, B-cell lymphoma-extra-large, and myeloid cell leukemia-1 were also analyzed. We found that hypoxia-inducible factor-1 alpha stabilization increased the appearance of apoptotic nucleus, fragmentation of DNA, and Caspase-3 and PARP-1 cleavage. Hypoxia mimicking conditions enhanced the expression of pro-apoptotic effectors BAX, BID, BAD, and BAK. Hypoxia-inducible factor-1 alpha stabilization also downregulated the level of BCL-2, B-cell lymphoma-extra-large, and myeloid cell leukemia-1. All these apoptotic parameters changes were reversed with leptin treatment. Moreover, we showed that leptin action on apoptosis modulation involves PI3K and MAPK signaling pathways. Obtained data demonstrate that hypoxia-inducible factor-1 alpha stabilization induces apoptosis in human placenta and leptin counteracts this effect, reinforcing its role as a survival cytokine.

Triple negative breast cancer cells exposed to aryl hydrocarbon receptor ligands hexachlorobenzene and chlorpyrifos activate endothelial cells.

Breast cancer is currently one of the most prevalent cancers worldwide. The mechanisms by which pesticides can increase breast cancer risk are multiple and complex. We have previously observed that two aryl hydrocarbon receptor (AhR) agonists ‒pesticides hexachlorobenzene (HCB) and chlorpyrifos (CPF)‒ act on tumor progression, stimulating cell migration and invasion in vitro and tumor growth in animal models. Elevated levels of hypoxia inducible factor-1α (HIF-1α) are found in malignant breast tumors, and HIF-1α is known to induce proangiogenic factors such as vascular endothelial growth factor (VEGF), nitric oxide synthase-2 (NOS-2) and cyclooxygenase-2 (COX-2), which are fundamental in breast cancer progression. In this work, we studied HCB (0.005, 0.05, 0.5 and 5 µM) and CPF (0.05, 0.5, 5 and 50 µM) action on the expression of these proangiogenic factors in triple negative breast cancer cells MDA-MB-231, as well as the effect of their conditioned medium (CM) on endothelial cells. Exposure to pesticides increased HIF-1α and VEGF protein expression in an AhR-dependent manner. In addition, HCB and CPF boosted NOS-2 and COX-2 content and VEGF secretion in MDA-MB-231 cells. The treatment of endothelial cells with CM from tumor cells exposed to pesticides increased cell proliferation, migration, and tubule formation, enhancing both tubule length and branching points. Of note, these effects were VEGF-dependent, as they were blocked in the presence of a VEGF receptor-2 (VEGFR-2) inhibitor. In sum, our results highlight the harmful impact of HCB and CPF in modulating the interaction between breast cancer and endothelial cells and promoting angiogenesis.

Aging changes the expression of adenosine receptors, insulin-like growth factor 1 (IGF1), and hypoxia-inducible factor 1α (HIF1α) in hypothalamic astrocyte cultures.

The aging process induces neurochemical alterations in different brain regions, including hypothalamus. This pivotal area of the central nervous system (CNS) is crucial for detection and integration of nutritional and hormonal signals from the periphery of the body to maintain metabolic homeostasis. Astrocytes support the CNS homeostasis, energy metabolism, and inflammatory response, as well as increasing evidence has highlighted a critical role of astrocytes in orchestrating hypothalamic functions and in gliocrine system. In this study, we aimed to investigate the age-dependent mRNA expression of adenosine receptors, the insulin-like growth factor 1 receptor (IGF1R), and the hypoxia-inducible factor 1α (HIF1α), in addition to the levels of IGF1 and HIF1α in hypothalamic astrocyte cultures derived from newborn, adult, and aged rats. Our results revealed age-dependent changes in adenosine receptors, as well as a decrease in IGF1R/IGF1 and HIF1α. Of note, adenosine receptors, IGF1, and HIF1α are affected by inflammatory, redox, and metabolic processes, which can remodel hypothalamic properties, as observed in aging brain, reinforcing the role of hypothalamic astrocytes as targets for understanding the onset and/or progression of age-related diseases.

New immunological aspects of peri-implantitis

ABSTRACT Objective: This study aimed to compare the levels of HIF1-α, VEGF, TNF-α, and IL-10 in the peri-implant crevicular fluid of patients with and without peri-implantitis. Methods: Forty patients, comprising 16 with and 24 without peri-implantitis were selected. Results: Patients with peri-implantitis exhibited significantly higher HIF-1α levels than those without peri-implantitis (p=0.0005). TNF-α revealed significant positive correlations with IL-10 (p=0.0008) and VEGF (p=0.0246), whereas HIF-1α and IL-10 levels (p=0.0041) demonstrated a negative and significative correlation in the peri-implantitis group. Conclusion: This study, for the first time demonstrates the balance of HIF-1α, TNFα, IL-10, and VEGF in peri-implantitis. It shows an elevated HIF-1α levels in patients with peri-implantitis, which could have stemmed from persistent inflammation- triggered hypoxia. Furthermore, the positive correlation between TNF-α and VEGF suggests intensified proinflammatory activity in peri-implantitis. Nevertheless, further studies are essential to understand these immune dynamics in peri-implantitis.

[Regulación de la expresión de IL-33 e IL-17 por la modulación farmacológica de HIF-1 en un modelo murino de inflamación alérgica pulmonar].

Objective: To evaluate the effect of pharmacological modulation of HIF-1 on the expression of IL-33 and IL-17 in a murine model of allergic pulmonary inflam- mation (API) with different degrees of severity. Methods: 5 mice/group received ovalbumin (OVA) 1(mild), 2(moderate) or 3(severe) challenges via i.t. prior to allergen sensitization, in addition to the HIF-1 induction or inhibition groups, received EDHB (OVA+EDHB) i.p. or 2ME (OVA+2ME) i.t. respectively. Control groups received saline solution (SS) in the same way. HE (inflammatory infiltrate), PAS (mucus production) and immunohistochemical staining for HIF-1a, IL-33, IL-17 were performed, quantitatively analyzing by digital pathology. Results: We obtained different degrees of severity with a greater number of challenges, increasing the expression of HIF-1, correlating with the expression of IL-33/IL-17. Increasing or decreasing, respectively by pharmacological modulation. Conclusions: The above suggests that the high expression of HIF-1 favors the production of IL-33 and IL-17 contributing to the damage in lung tissue and the severity of the disease and these can be regulated through the modulation of HIF- 1.

Objetivo: Evaluar el efecto de la modulación farmacológica de HIF-1 en la expresión de IL-33 e IL-17 en un modelo murino de inflamación alérgica pulmonar (IAP) con diferentes grados de severidad. Métodos: 5 ratones/grupo recibieron ovoalbúmina (OVA) 1(leve), 2(moderada) o 3(severa) retos vía i.t. previa sensibilización como alergeno, además los grupos de inducción o inhibición de HIF-1a, recibieron EDHB (OVA+EDHB) i.p. o 2ME (OVA+2ME) i.t. respectivamente. Los grupos controles recibieron solución salina (SS) de igual forma. Se realizaron tinciones de HE (infiltrado inflamatorio), PAS (producción de moco) e inmunohistoquímicas de HIF-1a, IL-33, IL-17, analizando cuantitativamente por patología digital. Resultados: Obtuvimos diferentes grados de severidad a mayor número de retos, incrementando la expresión de HIF-1, correlacionando con la expresión de IL- 33/IL-17. Aumentando o disminuyendo, respectivamente por la modulación farmacológica. Conclusiones: Lo anterior sugiere que la alta expresión de HIF-1 favorece la producción de IL-33 e IL-17 contribuyendo al daño en el tejido pulmonar y la severi- dad de la enfermedad y estas pueden ser reguladas a través de la modulación de HIF-1.

Transcriptomics Provides Novel Insights into the Regulatory Mechanism of IncRNA HIF1 A-AS1 on Vascular Smooth Muscle Cells.

INTRODUCTION: Thoracic aortic aneurysm is a potentially fatal disease with a strong genetic contribution. The dysfunction of vascular smooth muscle cells (VSMCs) contributes to the formation of this aneurysm. Although previous studies suggested that long non-coding ribonucleic acid (RNA) hypoxia inducible factor 1 α-antisense RNA 1 (HIF1A-AS1) exerted a vital role in the progression and pathogenesis of thoracic aortic aneurysm, we managed to find a new regulatory mechanism of HIF1A-AS1 in VSMCs via transcriptomics. METHODS: Cell viability was detected by the cell counting kit-8 assay. Cell apoptosis was assessed by Annexin V-fluorescein isothiocyanate/propidium iodide double staining. Transwell migration assay and wound healing assay were performed to check the migration ability of HIF1A-AS1 on VSMCs. The NextSeq XTen system (Illumina) was used to collect RNA sequencing data. Lastly, reverse transcription-quantitative polymerase chain reaction confirmed the veracity and reliability of RNA-sequencing results. RESULTS: We observed that overexpressing HIF1A-AS1 successfully promoted apoptosis, significantly altered cell cycle distribution, and greatly attenuated migration in VSMCs, further highlighting the robust promoting effects of HIF1A-AS1 to thoracic aortic aneurysm. Moreover, transcriptomics was implemented to uncover its underlying mechanism. A total of 175 differently expressed genes were identified, with some of them enriched in apoptosis, migration, and cell cycle-related pathways. Intriguingly, some differently expressed genes were noted in vascular development or coagulation function pathways. CONCLUSION: We suggest that HIF1A-AS1 mediated the progression of thoracic aortic aneurysm by not only regulating the function of VSMCs, but also altering vascular development or coagulation function.

Factor inducible por hipoxia en cáncer

El oxígeno y dióxido de carbono son vitales en la respiración, sus variaciones fuera del rango fisiológico son una amenaza para la supervivencia de las células. La hipoxia es una condición común en la mayoría de los tumores malignos, la cual promueve angiogénesis y vascularización disfuncional, mayor proliferación celular y la adquisición de un fenotipo de transición epitelial a mesenquimatoso, que contribuye con la metástasis; asimismo, altera el metabolismo de las células cancerosas y genera resistencia a la terapia, ya que induce a la inactividad celular. Por tanto, la hipoxia es un factor negativo, asociado a resultados adversos en la mayoría de los tratamientos de los distintos tipos de cáncer. El factor inducible por hipoxia (HIF) es el factor de transcripción relacionado con la hipoxia en cáncer, que produce la activación de más de una centena de genes reguladores de la actividad celular, que generan funciones cruciales para el desarrollo del cáncer. El objetivo principal de la presente revisión es puntualizar la importancia de la hipoxia en la génesis del cáncer, conocer las principales moléculas que interactúan en la expresión del HIF, explicar los mecanismos moleculares de las vías involucradas en la inducción del HIF, las consecuencias celulares por su alteración y las potenciales terapias dirigidas contra este factor. Se consultaron PubMed, Scopus y SciELO, del año 1990 hasta el año 2022, y se buscaron las referencias bibliográficas en relación con las palabras clave asociadas al factor inducible por hipoxia y cáncer. En conclusión, la sobreexpresión de HIF-1α en biopsias tumorales se asocia con una mayor mortalidad de pacientes en cánceres humanos. Los posibles genes diana regulados por HIF-1α que pueden desempeñar un papel en la progresión tumoral están empezando a descubrirse. A pesar de que se han estudiado cientos de compuestos en relación con el HIF en cáncer, en la actualidad existen pocos inhibidores del HIF aprobados en el mercado mundial; asimismo, muchos estudios clínicos, en sus distintas fases en desarrollo, no muestran resultados alentadores. Probablemente, en el futuro, cuando se tenga una mejor comprensión de la estructura, funcionamiento molecular y biológico de este factor, se desarrollarán fármacos más específicos para la inhibición del HIF.

Oxygen and carbon dioxide are essential for breathing; variations in these gases outside of the normal range are a threat to cell survival. Hypoxia is a common condition that occurs in most malignant tumors, increases angiogenesis and defective vascularization, promotes cell proliferation and acquires an epithelial-mesenchymal transition phenotype, which causes metastasis. It also affects cancer cell metabolism and makes patients resistant to treatment by causing cell quiescence. As a result, hypoxia is a detrimental component that is linked to unfavorable outcomes in most cancer treatments. Through the activation of more than a hundred genes that control cell activity, which produce key functions for cancer development, the transcription factor known as hypoxia-inducible factor (HIF) is linked to hypoxia in cancer. This review's main goals are to highlight the role of hypoxia in the development of cancer, identify the key molecules that interact to promote HIF expression, explain the molecular mechanisms of the pathways that lead to HIF induction, describe the cellular effects of HIF alteration, and discuss potential HIF-targeted therapies. Articles from 1990 to 2022 were reviewed in PubMed, Scopus and SciELO databases. Keywords related to cancer and HIF were searched in bibliographical references. In conclusion, HIF-1α overexpression in tumor biopsies is associated with increased patient mortality in human cancers. Potential HIF-1α-regulated target genes that may play a role in tumor progression are starting to be identified. Although hundreds of chemicals have been studied in relation to HIF in cancer, there are currently few approved HIF inhibitors available on the global market; moreover, many clinical trials, in their various stages of development, do not show encouraging results. It is likely that in the future, when there is a better understanding of the structure, molecular and biological functioning of this factor, more specific drugs for HIF inhibition will be developed.

Association of Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitors with Cardiovascular Events and Death in Dialysis Patients: A Systematic Review and Meta-Analysis.

BACKGROUND: Anemia is a common finding among patients with advanced chronic kidney disease, especially those on dialysis. The recent introduction of hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) has raised some concerns about the cardiovascular and thrombotic complications of this class of drugs. OBJECTIVES: This meta-analysis aimed to assess the safety of HIF-PHIs in patients with end-stage kidney disease (ESKD) versus standard therapy with erythropoiesis-stimulating agents (ESAs). METHODS: Databases were searched on April 2022. Studies that reported incidence of all-cause mortality; major cardiovascular adverse events (MACEs); myocardial infarction (MI); stroke and thrombotic events in the use of HIF-PHIs or ESA on ESKD patients in hemodialysis or peritoneal dialysis were evaluated. Data were extracted from published reports, and quality assessment was performed per Cochrane recommendations. RESULTS: 12,821 patients from ten randomized controlled trials were included in this study. Most patients (83%) were on hemodialysis. 6,461 (50.3%) were using HIF-PHIs, and 6,360 (49.6%) were in the ESA group. The pooled estimated incidence of all-cause mortality was 769 in the HIF-PHIs group (relative-risk ratios (RR): 1.04; confidence interval (CI): 0.95-1.14; p = 0.52; I2 = 0%). There was no difference in the groups regarding the outcomes of MACE in the analysis of the three studies that reported this outcome (RR: 0.95; CI: 0.87-1.04; p = 0.69; I2 = 0%). In addition, there was no statistical difference among the outcomes of MI, stroke, or thrombotic events. CONCLUSIONS: Among patients with ESKD on dialysis, the use of HIF-PHIs was non-inferior regarding the safety outcomes when compared to standard of care therapy.

Computational and atomistic studies applied to the understanding of the structural and behavioral features of the immune checkpoint HLA-G molecule and gene.

We took advantage of the increasingly evolving approaches for in silico studies concerning protein structures, protein molecular dynamics (MD), protein-protein and protein-DNA docking to evaluate: (i) the structure and MD characteristics of the HLA-G well-recognized isoforms, (ii) the impact of missense mutations at HLA-G receptor genes (LILRB1/2), and (iii) the differential binding of the hypoxia-inducible factor 1 (HIF1) to hypoxia-responsive elements (HRE) at the HLA-G gene. Besides reviewing these topics, they were revisited including the following novel results: (i) the HLA-G6 isoforms were unstable docked or not with ß2-microglobulin or peptide, (ii) missense mutations at LILRB1/2 genes, exchanging amino acids at the intracellular domain, particularly those located within and around the ITIM motifs, may impact the HLA-G binding strength, and (iii) HREs motifs at the HLA-G promoter or exon 2 regions exhibiting a guanine at their third position present a higher affinity for HIF1 when compared to an adenine at the same position. These data shed some light into the functional aspects of HLA-G, particularly how polymorphisms may influence the role of the molecule. Computational and atomistic studies have provided alternative tools for experimental physical methodologies, which are time-consuming, expensive, demanding large quantities of purified proteins, and exhibit low output.

Transcriptomics Provides Novel Insights into the Regulatory Mechanism of IncRNA HIF1 A-AS1 on Vascular Smooth Muscle Cells

ABSTRACT Introduction: Thoracic aortic aneurysm is a potentially fatal disease with a strong genetic contribution. The dysfunction of vascular smooth muscle cells (VSMCs) contributes to the formation of this aneurysm. Although previous studies suggested that long non-coding ribonucleic acid (RNA) hypoxia inducible factor 1 α-antisense RNA 1 (HIF1A-AS1) exerted a vital role in the progression and pathogenesis of thoracic aortic aneurysm, we managed to find a new regulatory mechanism of HIF1A-AS1 in VSMCs via transcriptomics. Methods: Cell viability was detected by the cell counting kit-8 assay. Cell apoptosis was assessed by Annexin V-fluorescein isothiocyanate/propidium iodide double staining. Transwell migration assay and wound healing assay were performed to check the migration ability of HIF1A-AS1 on VSMCs. The NextSeq XTen system (Illumina) was used to collect RNA sequencing data. Lastly, reverse transcription-quantitative polymerase chain reaction confirmed the veracity and reliability of RNA-sequencing results. Results: We observed that overexpressing HIF1A-AS1 successfully promoted apoptosis, significantly altered cell cycle distribution, and greatly attenuated migration in VSMCs, further highlighting the robust promoting effects of HIF1A-AS1 to thoracic aortic aneurysm. Moreover, transcriptomics was implemented to uncover its underlying mechanism. A total of 175 differently expressed genes were identified, with some of them enriched in apoptosis, migration, and cell cycle-related pathways. Intriguingly, some differently expressed genes were noted in vascular development or coagulation function pathways. Conclusion: We suggest that HIF1A-AS1 mediated the progression of thoracic aortic aneurysm by not only regulating the function of VSMCs, but also altering vascular development or coagulation function.

Activation hypoxia inducible factor-1α gene affected the tumor microenvironment and induced recurrence and invasion of bladder cancer in vitro.

OBJECTIVE: This work aimed to investigate the molecular mechanism of the activation of hypoxia-inducible factors under different low oxygen partial pressures. METHODS: Strictly follow in vitro aseptic culture of bladder cancer cell line UMUC3 and when the cells grow in the logarithmic phase, culture the cells under different low oxygen partial pressures. Among these groups, two groups of cells were transfected with small interfering-hypoxia inducible factor 1α (si-HIF-1α) liposome plasmids to silencing the HIF-1α expression. RESULTS: Cell cloning experiment showed that HIF-1α will increase cell adhesion and proliferation under hypoxia. Matrigel angiogenesis experiment showed that hypoxia has a negative impact on the angiogenesis of tumor cells. Cell scratch test indicated that hypoxia has a greater impact on the migration ability of cancer cells, and HIF-1α has a significant impact on the migration process. Cell invasion test proved that hypoxia has a greater impact on the invasion ability of cancer cells, and HIF-1α has a great impact on the invasion process. CONCLUSION: HIF-1α can target the regulatory gene vascular endothelial growth factor to promote tumor cell proliferation, migration, invasion, neovascularization and lymph node metastasis.

OBJETIVO: Por lo tanto, este trabajo investiga el mecanismo molecular de la activación de factores inducibles por hipoxia bajo diferentes presiones parciales de oxígeno bajas. MÉTODOS: Siga estrictamente el cultivo aséptico in vitro de la línea celular de cáncer de vejiga UMUC3 y cuando las células crezcan en la fase logarítmica, cultive las células bajo diferentes presiones parciales de oxígeno bajas. Entre estos grupos, se transfectaron dos grupos de células con plásmidos de liposomas si-HIF-1α para silenciar la expresión de HIF-1α. RESULTADOS: El experimento de clonación celular mostró que HIF-1α aumentará la adhesión y proliferación celular bajo hipoxia. El experimento de angiogénesis de Matrigel mostró que la hipoxia tiene un impacto negativo en la angiogénesis de las células tumorales. La prueba de raspado celular indicó que la hipoxia tiene un mayor impacto en la capacidad de migración de las células cancerosas, y HIF-1α tiene un impacto significativo en el proceso de migración. La prueba de invasión celular demostró que la hipoxia tiene un mayor impacto en la capacidad de invasión de las células cancerosas y HIF-1α tiene un gran impacto en el proceso de invasión. CONCLUSIÓN: HIF-1α puede dirigirse al gen regulador vascular endothelial growth factor para promover la proliferación, migración, invasión, neovascularización y metástasis en los ganglios linfáticos de las células tumorales.

Dexmedetomidine Leads to the Mitigation of Myocardial Ischemia/Reperfusion-Induced Acute Lung Injury in Diabetic Rats Via Modulation of Hypoxia-Inducible Factor-1α

ABSTRACT Introduction: The objective of this study is to investigate the protective mechanism of dexmedetomidine (Dex) in myocardial ischemia/reperfusion (MIR)-induced acute lung injury (ALI) of diabetic rats by inhibiting hypoxia-inducible factor-1α (HIF-1α). Methods: Initially, healthy male Sprague Dawley rats were treated with streptozocin to induce diabetes. Then, three weeks after the induction, Dex or lentiviral vector (LV)-HIF-1α was injected into the rats 30 minutes prior to the MIR modeling. After four weeks, lung tissues were harvested for pathological changes observation and the wet/dry weight (W/D) ratio determination. Afterwards, oxidative stress indicators and pro-inflammatory factors were measured. In addition, HIF-1α expression was assessed by immunohistochemistry and western blot analysis. Results: Dex could suppress inflammatory cell infiltration, improve lung tissue structure, reduce pathological score and the W/D ratio, and block oxidative stress and inflammatory response in MIR-induced ALI of diabetic rats. Besides, Dex could also inhibit HIF-1α expression. Moreover, Dex + LV-HIF-1α reversed the protective role of Dex on diabetic MIR-induced ALI. Conclusion: Our study has made it clear that Dex inhibited the upregulation of HIF-1α in diabetic MIR-induced ALI, and thus protect lung functions by quenching the accumulation of oxygen radical and reducing lung inflammatory response.

Dexmedetomidine Leads to the Mitigation of Myocardial Ischemia/Reperfusion-Induced Acute Lung Injury in Diabetic Rats Via Modulation of Hypoxia-Inducible Factor-1α.

INTRODUCTION: The objective of this study is to investigate the protective mechanism of dexmedetomidine (Dex) in myocardial ischemia/reperfusion (MIR)-induced acute lung injury (ALI) of diabetic rats by inhibiting hypoxia-inducible factor-1α (HIF-1α). METHODS: Initially, healthy male Sprague Dawley rats were treated with streptozocin to induce diabetes. Then, three weeks after the induction, Dex or lentiviral vector (LV)-HIF-1α was injected into the rats 30 minutes prior to the MIR modeling. After four weeks, lung tissues were harvested for pathological changes observation and the wet/dry weight (W/D) ratio determination. Afterwards, oxidative stress indicators and pro-inflammatory factors were measured. In addition, HIF-1α expression was assessed by immunohistochemistry and western blot analysis. RESULTS: Dex could suppress inflammatory cell infiltration, improve lung tissue structure, reduce pathological score and the W/D ratio, and block oxidative stress and inflammatory response in MIR-induced ALI of diabetic rats. Besides, Dex could also inhibit HIF-1α expression. Moreover, Dex + LV-HIF-1α reversed the protective role of Dex on diabetic MIR-induced ALI. CONCLUSION: Our study has made it clear that Dex inhibited the upregulation of HIF-1α in diabetic MIR-induced ALI, and thus protect lung functions by quenching the accumulation of oxygen radical and reducing lung inflammatory response.

The Protective Role of pVHL in Imiquimod-Induced Psoriasis-like Skin Inflammation.

Psoriasis is a chronic inflammatory disease distinguished by an excessive proliferation and abnormal differentiation of keratinocytes. Immune cells, such as T lymphocytes and neutrophils, and inflammatory cytokines, such as Tumor Necrosis Factor-α (TNF-α) and interleukin 17 (IL-17), are essential for maintaining psoriatic lesions. Additionally, a hypoxic milieu present in the skin promotes the expression of transcriptional factor hypoxia-inducible factor-1 alpha (HIF-1α). This protein regulates the expression of angiogenic and glycolytic factors, such as vascular endothelial grown factor and lactate dehydrogenase (LDH), both relevant in chronic inflammation. The von Hippel-Lindau protein (pVHL) is a negative regulator of HIF-1α. Previously, we found that pVHL was almost absent in the lesions of psoriasis patients; therefore, we investigated the impact of rescue pVHL expression in lesional skin. We used the imiquimod-induced psoriasis-like mouse model as an adenoviral vector that allowed us to express pVHL in the skin. Our data show that, in lesional skin, pVHL expression was reduced, whereas HIF-1α was increased. Remarkably, the retrieval of pVHL prevented psoriatic lesions, diminishing erythema, scale, and epidermal and vascular thickness. Furthermore, pVHL expression was capable of reducing HIF-1α, LDH, TNF-α and immune cell infiltration (mainly IL-17+ neutrophils). In conclusion, our results demonstrate that pVHL has a protective role to play in the pathophysiology of psoriasis.

Restricted Activation of the NF-κB Pathway in Individuals with Latent Tuberculosis Infection after HIF-1α Blockade.

Tuberculous granuloma formation is mediated by hypoxia-inducible factor 1 alpha (HIF-1α), and is essential for establishing latent tuberculosis infection (LTBI) and its progression to active tuberculosis (TB). Here, we investigated whether HIF-1α expression and adjacent mechanisms were associated with latent or active TB infection. Patients with active TB, individuals with LTBI, and healthy controls were recruited, and the expression of cytokine genes IL15, IL18, TNFA, IL6, HIF1A, and A20 in peripheral blood mononuclear cells (PBMCs) and serum vitamin D (25(OH)D3) levels were evaluated. Additionally, nuclear factor kappa B (NF-κB) and tumor necrosis factor-alpha (TNF-α) levels were analyzed in PBMC lysates and culture supernatants, respectively, after HIF-1α blockade with 2-methoxyestradiol. We observed that IL-15 expression was higher in individuals with LTBI than in patients with active TB, while IL-18 and TNF-α expression was similar between LTBI and TB groups. Additionally, serum 25(OH)D3 levels and expression of IL-6, HIF1A, and A20 were higher in patients with active TB than in individuals with LTBI. Moreover, PBMCs from individuals with LTBI showed decreased NF-κB phosphorylation and increased TNF-α production after HIF-1α blockade. Together, these results suggest that under hypoxic conditions, TNF-α production and NF-κB pathway downregulation are associated with the LTBI phenotype.

Effect of acute swimming exercise at different intensities but equal total load over metabolic and molecular responses in swimming rats.

Acute metabolic and molecular response to exercise may vary according to exercise's intensity and duration. However, there is a lack regarding specific tissue alterations after acute exercise with aerobic or anaerobic predominance. The present study investigated the effects of acute exercise performed at different intensities, but with equal total load on molecular and physiological responses in swimming rats. Sixty male rats were divided into a control group and five groups performing an acute bout of swimming exercise at different intensities (80, 90, 100, 110 and 120% of anaerobic threshold [AnT]). The exercise duration of each group was balanced so all groups performed at the same total load. Gene expression (HIF-1α, PGC-1α, MCT1 and MCT4 mRNA), blood biomarkers and tissue glycogen depletion were analyzed after the exercise session. ANOVA One-Way was used to indicate statistical mean differences considering 5% significance level. Blood lactate concentration was the only biomarker sensitive to acute exercise, with a significant increase in rats exercised above AnT intensities (p < 0.000). Glycogen stores of gluteus muscle were significantly reduced in all exercised animals in comparison to control group (p = 0.02). Hepatic tissue presented significant reduction in glycogen in animals exercised above AnT (p = 0.000, as well as reduced HIF-1α mRNA and increased MCT1 mRNA, especially at the highest intensity (p = 0.002). Physiological parameters did not alter amongst groups for most tissues. Our results indicate the hepatic tissue alterations (glycogen stores and gene expressions) in response to different exercise intensities of exercise, even with the total load matched.

Effects of moderate-intensity intermittent hypoxic training on health outcomes of patients recovered from COVID-19: the AEROBICOVID study protocol for a randomized controlled trial.

BACKGROUND: Recent studies point to a lower number and reduced severity of cases in higher altitude cities with decreased oxygen concentration. Specific literature has shown several benefits of physical training, so, in this sense, physical training with hypoxic stimulus appears as an alternative that supports the conventional treatments of the COVID-19 patient's recovery. Thus, this study's primary aim is to analyze the effects of moderate-intensity intermittent hypoxic training on health outcomes in COVID-19 recovered patients. METHODS: A clinical trial controlled double-blind study was designed. Participants (30-69 years old) will be recruited among those with moderate to severe COVID-19 symptoms, approximately 30 days after recovery. They will be included in groups according to the training (T) and recovery (R) association with hypoxia (H) or normoxia (N): (a) TH:RH, (b) TN:RH, (c) TN:RN, and last (d) the control group. The 8-week exercise bike intervention will be carried out with a gradual load increase according to the established periods, three times a week in sets of 5 min, 90 to 100% of the anaerobic threshold (AT), and a 2.5-min break. Blood will be collected for genotyping. First, after 4 weeks (partial), after 8 weeks, and later, 4 weeks after the end of the physical training intervention, participants will perform assessments. The primary outcome is the maximum oxygen consumption (VO2peak). The secondary outcomes include lung function, inflammatory mediators, hematological, autonomic parameters, AT, body composition analysis, quality of life, mental health, anthropometric measurements, and physical fitness. The statistical analysis will be executed using the linear regression model with mixed effects at a 5% significance level. DISCUSSION: This study is designed to provide evidence to support the clinical benefits of moderate-intensity intermittent hypoxic training as a part of the treatment of patients recovered from COVID-19. It may also provide evidence on the efficacy and safety of intermittent hypoxic training in different health conditions. Lastly, this study presents an innovative strategy enabling up to 16 participants in the same training session. TRIAL REGISTRATION: ClinicalTrials.gov RBR-5d7hkv. Registered after the start of inclusion on 3 November 2020 with the Brazilian Clinical Trials Registry.

Metabolic Reprogramming and Inflammatory Response Induced by D-Lactate in Bovine Fibroblast-Like Synoviocytes Depends on HIF-1 Activity.

Acute ruminal acidosis (ARA) occurs after an excessive intake of rapidly fermentable carbohydrates and is characterized by the overproduction of D-lactate in the rumen that reaches the bloodstream. Lameness presentation, one of the primary consequences of ARA in cattle, is associated with the occurrence of laminitis and aseptic polysynovitis. Fibroblast-like synoviocytes (FLS) are predominant cells of synovia and play a key role in the pathophysiology of joint diseases, thus increasing the chances of the release of pro-inflammatory cytokines. Increased D-lactate levels and disturbances in the metabolism of carbohydrates, pyruvates, and amino acids are observed in the synovial fluid of heifers with ARA-related polysynovitis prior to neutrophil infiltration, suggesting an early involvement of metabolic disturbances in joint inflammation. We hypothesized that D-lactate induces metabolic reprogramming, along with an inflammatory response, in bovine exposed FLS. Gas chromatography-mass spectrometry (GC-MS)-based metabolomics revealed that D-lactate disrupts the metabolism of bovine FLS, mainly enhancing glycolysis and gluconeogenesis, pyruvate metabolism, and galactose metabolism. The reverse-transcription quantitative PCR (RT-qPCR) analysis revealed an increased expression of metabolic-related genes, including hypoxia-inducible factor 1 (HIF-1)α, glucose transporter 1 (Glut-1), L-lactate dehydrogenase subunit A (L-LDHA), and pyruvate dehydrogenase kinase 1 (PDK-1). Along with metabolic disturbances, D-lactate also induced an overexpression and the secretion of IL-6. Furthermore, the inhibition of HIF-1, PI3K/Akt, and NF-κB reduced the expression of IL-6 and metabolic-related genes. The results of this study reveal a potential role for D-lactate in bFLS metabolic reprogramming and support a close relationship between inflammation and metabolism in cattle.