Hypoxemia is a common pathological state characterized by low oxygen saturation in the blood. This condition compromises mucosal barrier integrity particularly in the gut and oral cavity. However, the mechanisms underlying this association remain unclear. This study used periodontitis as a model to investigate the role of platelet activation in oral mucosal immunopathology under hypoxic conditions. Hypoxia upregulated methyltransferase-like protein 4 (METTL4) expression in platelets, resulting in N⁶-methyladenine modification of mitochondrial DNA (mtDNA). This modification impaired mitochondrial transcriptional factor A-dependent cytosolic mtDNA degradation, leading to cytosolic mtDNA accumulation. Excess cytosolic mt-DNA aberrantly activated the cGAS-STING pathway in platelets. This resulted in excessive platelet activation and neutrophil extracellular trap formation that ultimately exacerbated periodontitis. Targeting platelet METTL4 and its downstream pathways offers a potential strategy for managing oral mucosa immunopathology. Further research is needed to examine its broader implications for mucosal inflammation under hypoxic conditions.
DNA, Mitochondrial/metabolism* ; Mouth Mucosa/pathology* ; Hypoxia/immunology* ; Methyltransferases/metabolism* ; Blood Platelets/metabolism* ; Animals ; Periodontitis/immunology* ; Humans ; Platelet Activation ; Mice

Adipose tissue hypoxia has been recognized as the initiation of insulin resistance syndromes. The aim of the present study was to investigate the effects of mangiferin on the insulin signaling pathway and explore whether mangiferin could ameliorate insulin resistance caused by hypoxia in adipose tissue. Differentiated 3T3-L1 adipocytes were incubated under normal and hypoxic conditions, respectively. Protein expressions were analyzed by Western blotting. Inflammatory cytokines and HIF-1-dependent genes were tested by ELISA and q-PCR, respectively. The glucose uptake was detected by fluorescence microscopy. HIF-1α was abundantly expressed during 8 h of hypoxic incubation. Inflammatory reaction was activated by up-regulated NF-κB phosphorylation and released cytokines like IL-6 and TNF-α. Glucose uptake was inhibited and insulin signaling pathway was damaged as well. Mangiferin substantially inhibited the expression of HIF-1α. Lactate acid and lipolysis, products released by glycometabolism and lipolysis, were also inhibited. The expression of inflammatory cytokines was significantly reduced and the damaged insulin signaling pathway was restored to proper functional level. The glucose uptake of hypoxic adipocytes was promoted and the dysfunction of adipocytes was relieved. These results showed that mangiferin could not only improve the damaged insulin signaling pathway in hypoxic adipocytes, but also ameliorate inflammatory reaction and insulin resistance caused by hypoxia.
3T3-L1 Cells ; Adipocytes ; drug effects ; immunology ; Adipokines ; genetics ; immunology ; Animals ; Cell Hypoxia ; drug effects ; Glucose ; metabolism ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; immunology ; Insulin ; metabolism ; Insulin Resistance ; Mice ; NF-kappa B ; genetics ; immunology ; Oxygen ; metabolism ; Tumor Necrosis Factor-alpha ; genetics ; immunology ; Xanthones ; pharmacology

BACKGROUNDHypoxia promotes tumor angiogenesis and hypoxia-inducible factor-1 alpha (HIF-1α) plays a pivotal role in this process. Recently identified pro-angiogenic factor, semaphorin4D (Sema4D) also promotes angiogenesis and enhances invasive proliferation in some tumors. Furthermore, tumor-associated macrophages (TAMs) can increase the expression of HIF-1α and Sema4D in cancer cells and thus influence tumor growth and progression. The purpose of this study was to evaluate the effect of TAMs on the expression of Sema4D and HIF-1α and the impact of biologic behavior in colon cancer cells.

METHODSImmunohistochemistry was used to analyze HIF-1α and Sema4D expression in 86 curatively resected colon cancer samples and 52 normal colon tissues samples. The relationship between their expression and clinicopathological factors was analyzed. Furthermore, macrophage-tumor cell interactions, such as metastasis, angiogenesis, were also studied using in vitro co-culture systems. Statistical analysis was performed using SPSS 17.0 software (SPSS Inc., USA). Differences between two groups were analyzed with Student's t test.

RESULTSHIF-1α (58%) and Sema4D (60%) were expressed at a significantly higher level in tumors than in normal tissues (P < 0.01, for both). Furthermore, HIF-1α and Sema4D expression was significantly correlated with lymphatic metastasis, specific histological types and TNM stages (P < 0.05), but not with age and tumor size (P > 0.05). Sema4D expression was correlated with that of HIF-1α (r = 0.567, P < 0.01). TAMs markedly induced HIF-1α and Sema4D expression in colon cancer cells and subsequently increased their migration and invasion.

CONCLUSIONSHIF-1α and Sema4D expression are closely related to lymphatic metastasis, specific histological types and TNM stages in colon cancer. Furthermore, TAMs promote migration and invasion of colon cancer cells and endothelial tube formation, possibly through up-regulation of HIF-1α and Sema4D.

Adult ; Aged ; Antigens, CD ; genetics ; metabolism ; Cell Line, Tumor ; Colonic Neoplasms ; genetics ; metabolism ; Female ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Immunohistochemistry ; Macrophages ; immunology ; metabolism ; Male ; Middle Aged ; Neoplasm Metastasis ; genetics ; pathology ; Semaphorins ; genetics ; metabolism

OBJECTIVETo explore the effect of hypoxia on the peripheral blood T lymphocyte subsets and co-stimulatory molecules in rats so as to provide the basis for studying the intervention measure.

METHODSBefore hypoxia and during hypoxia at 8 000 m for 8 h, 3 d, 6 d and 10 d the change of peripheral blood T lymphocyte subsets and co-stimulatory molecules in rats were detected by flowcytometer with three-color immunofluorescence label.

RESULTSRats were exposed to hypoxia at 8 000 m for 8 hours, and CD3+, CD8+, CD8+ CD28- lymphocyte percentages were significantly decreased (P < 0.01) compared with that before hypoxia. After 3 days of hypoxia, besides aforesaid change, CD4+ CD28+ lymphocyte percentage also prominently decreased (P < 0.01) and CD4+ CD28- prominently increased (P < 0.01). After 6 and 10 days of hypoxia, CD3+, CD4+ lymphocyte percentages were further decreased, while CD8+ CD28+ lymphocyte percentage significantly increased (P < 0.01).

CONCLUSIONAfter exposed to hypoxia at 8 000 m for 8 hours and 3 days, activation of CD8+ and CD4+ T lymphocyte was prominently decreased, while with the prolong of exposed time activation of CD8+ T lymphocyte was significantly increased.

Altitude ; Altitude Sickness ; physiopathology ; Animals ; CD4-Positive T-Lymphocytes ; physiology ; CD8-Positive T-Lymphocytes ; physiology ; Hypoxia ; immunology ; physiopathology ; Lymphocyte Activation ; physiology ; Male ; Rats ; Rats, Wistar ; T-Lymphocytes ; physiology

OBJECTIVETo explore the characteristic of hypoxia-induced immune injury, its mechanisms and the intervention measure.

METHODSThe change of immune organ index, T lymphocyte subsets of peripheral blood and immune organ in mice during hypoxia were detected. Lymphocyte apoptosis of immune organ, pathology of lung and kidney in mice were observed. Then by way of prophylaxis we studied the effect of Chinese Traditional Medicine on hypoxia-induced immune injury in mice.

RESULTS(1) Exposure to hypoxia at 8 000 m simulated altitude for 8 h resulted in marked decrease in CD4+ CD8+ thymocytes and marked increase in CD4+ CD8-, CD4- CD8+ thymocytes (P < 0.01). After 3 days of hypoxia, the mice had a much lower percentage of CD4+ T-cell (P < 0.05). The ratio of CD4+/CD8+ decreased significantly and aforesaid changes of thymocyte were further enlarged. Also mice had a pronounced increase in rates of late apoptosis or necrosis of spleen lymphocyte and thymocyte (P < 0.05). After 6 days of hypoxia, index of spleen was significantly increased (P < 0.05), index of thymus was significantly decreased (P < 0.05) and CD3+, CD4+, CD8+ lymphocyte percentage of spleen were significantly decreased (P < 0.01). Also late apoptosis or necrosis lymphocytes of spleen and thymus were further increased (P < 0.01), viable cell rates of spleen lymphocyte and thymocytes were markedly decreased (P < 0.01), early apoptosis rates of spleen lymphocyte were markedly increased (P < 0.01). There was no significant change in the percentage of CD8+ lymphocyte in peripheral blood during the whole hypoxia period. (2) New Compound Codonopsis Pilosula (NCCP), Xiang Qi Polysaccharide (XQP) and NCCP + XQP could significantly increase the number of peripheral blood CD3+, CD4+ and spleen CD4+, but had no significant influence on the number of spleen CD8+. XQP and XQP+ NCCP could significantly decrease the number of CD4+ CD8+ (P < 0.01), increase that of CD4+ CD8- (P < 0.01), and had no significant influence on CD4- CD8+ in thymus. However, NCCP didn't influence the component of thymocytes.

CONCLUSIONAfter hypoxia at 8 000 m simulated altitude decrease of lymphocyte of periphery in mice may be related with increase of apoptosis and necrosis of lymphocyte, and with increase of distribution of lymphocyte to lung in early period of exposure. NCCP and XQP have hopeful prospect in intervention study of hypoxia-induced immune injury.

Altitude ; Animals ; Apoptosis ; drug effects ; CD4-Positive T-Lymphocytes ; CD8-Positive T-Lymphocytes ; Drugs, Chinese Herbal ; pharmacology ; Flow Cytometry ; Hypoxia ; immunology ; pathology ; prevention & control ; Lung ; cytology ; Lymphocyte Count ; Male ; Medicine, Chinese Traditional ; Mice ; Mice, Inbred BALB C ; Spleen ; cytology ; T-Lymphocyte Subsets ; cytology ; drug effects ; Thymus Gland ; cytology

AIMTo elucidate the effect of CIHH on cellular immunity and humoral immunity in rat by using flow cytometry method, immunohistochemistry method and electron microscopy techniques.

METHODSForty-eight male adult Sprague-Dawley rats were randomly divided into 4 groups: control(CON) group, 14 days CIHH (CIHH14) group, 28 days CIHH (CIHH28) group, 42 days CIHH (CIHH42) group. The animals in CIHH groups were exposed to 14, 28 and 42 days hypobaric hypoxia(simulated 3 000 m altitude, 5 h per day), respectively. Half of the animals in each group was treated with normaxia and the other half animals were treated with acute hypoxia for 1 h. CD3, CD4, CD8 T lymphocytes, natural killer (NK) cells, IgG, cortisol, epirenamine and C-reactive protein were examined. The weight and ultrastructure of thymus and spleen were observed.

RESULTS(1) Compared with CON, both indexes of thymus and spleen in CIHH14 rats were increased significantly. Spleen index, but not thymus index, was increased in CIHH28 and CIHH42 rats. The thymocytes and spleen cytes in rat were injuryed during acute hypoxia, but the damage in CIHH rats was significant slighter than that in CON rats. (2) Compared with CON, CIHH28 and CIHH42, CD8 in CIHH14 rats were decreased, ratios of CD4/CD8 was increased and NK was decreased. (3) The rats of CON during acute hypoxia showed that CD4 was increased, CD8 was decreased, ratio of CD4/CD8 was elevated, and NK was increased. But there were no significant changes of CD3, CD4, CD8 and NK in CIHH28 and CIHH42 animals during acute hypoxia. (4) Compared with CON, CIHH28 and CIHH42, cortisol in CIHH14 rats was increased obviously, Epirenamine, cortisol and C-reactive protein in CON rats were increased, but there were no obvious changes in CIHH rats before and after acute hypoxia.

CONCLUSIONCIHH protects the immune function of rat against acute hypoxia, which is related with the regulation of neuroendocrine.

Altitude Sickness ; physiopathology ; Animals ; Atmospheric Pressure ; Hypoxia ; physiopathology ; Immunity, Cellular ; physiology ; Immunity, Humoral ; physiology ; Male ; Neuroimmunomodulation ; physiology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Spleen ; immunology ; T-Lymphocytes ; immunology ; Thymus Gland ; immunology

Antiviral Agents ; therapeutic use ; Cytokines ; metabolism ; Dendritic Cells ; immunology ; metabolism ; pathology ; Endotoxemia ; complications ; pathology ; Hepatitis B ; complications ; pathology ; Humans ; Hypoxia ; complications ; pathology ; Ischemia ; complications ; pathology ; Liver ; metabolism ; pathology ; Liver Failure ; etiology ; immunology ; pathology ; therapy ; T-Lymphocytes ; immunology ; pathology

Adult ; Aged ; Aged, 80 and over ; Antigens, CD ; immunology ; Endoglin ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Microvessels ; immunology ; Middle Aged ; Nitric Oxide Synthase Type II ; metabolism ; Receptors, Cell Surface ; immunology ; Uterine Cervical Neoplasms ; genetics ; metabolism

OBJECTIVETo investigate the role of adhesion molecules alphavbeta3 and alphavbeta5 and their ligands Del-1 and L1 in the tumor-endothelial cell adhesion in vitro.

METHODSThe expression of alphavbeta3, alphavbeta5 and ICAM-1 in liver sinusoidal endothelial cells (LSEC) and liver cancer endothelial cells (T3A) cultured under normoxia or hypoxia were analyzed by RT-PCR and fluorescent activated cell sorter (FACS). The expression of Del-1 and L1 in six tumor cell lines under normoxia or hypoxia were analyzed by RT-PCR and Western blot, respectively. The adhesion of dye-labeled tumor cells and endothelial LSEC and T3A cells was measured by a fluorescence plate reader after their culture.

RESULTSThe expression of alphavbeta3 and alphavbeta5 were higher in T3A cells than that in LSEC cells, and were upregulated under hypoxia, while the expression of ICAM-1 was lower in T3A cells than that in LSEC cells, and was upregulated under hypoxia only in LSEC. The expression of Del-1 and L1 molecules were obviously different in various tumor cell lines and were differentially regulated under hypoxia. The adhesion of tumor cells with Del-1 or L1 expression was higher in T3A cells than that in LSEC cells, and was significantly increased under hypoxia condition. Furthermore, the adhesion of tumor cells to T3A could be inhibited by antibodies against alphavbeta3 and alphavbeta5, or SiRNAs for beta3 and beta5.

CONCLUSIONalphavbeta3 and alphavbeta5 and their ligands Del-1 and L1 may play an important role in tumor cell migration.

Antibodies ; immunology ; Cell Adhesion ; Cell Hypoxia ; Cell Line, Tumor ; Endothelial Cells ; cytology ; metabolism ; Humans ; Integrin alphaVbeta3 ; genetics ; immunology ; metabolism ; Intercellular Adhesion Molecule-1 ; immunology ; metabolism ; Ligands ; Neoplasms ; metabolism ; pathology ; RNA Interference ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; pharmacology ; Receptors, Vitronectin ; genetics ; immunology ; metabolism

Reactive oxygen species (ROS) play an important role in the pathogenesis of airway inflammation and hyperresponsiveness. Recent studies have demonstrated that antioxidants are able to reduce airway inflammation and hyperreactivity in animal models of allergic airway disease. A newly developed antioxidant, small molecular weight thiol compound, N-acetylcysteine amide (AD4) has been shown to increase cellular levels of glutathione and to attenuate oxidative stress related disorders such as Alzheimer's disease, Parkinson's disease, and multiple sclerosis. However, the effects of AD4 on allergic airway disease such as asthma are unknown. We used ovalbumin (OVA)-inhaled mice to evaluate the role of AD4 in allergic airway disease. In this study with OVA-inhaled mice, the increased ROS generation, the increased levels of Th2 cytokines and VEGF, the increased vascular permeability, the increased mucus production, and the increased airway resistance in the lungs were significantly reduced by the administration of AD4. We also found that the administration of AD4 decreased the increases of the NF-kappaB and hypoxia-inducible factor-1alpha (HIF-1alpha) levels in nuclear protein extracts of lung tissues after OVA inhalation. These results suggest that AD4 attenuates airway inflammation and hyperresponsiveness by regulating activation of NF-kappaB and HIF-1alpha as well as reducing ROS generation in allergic airway disease.
Acetylcysteine/*analogs & derivatives/therapeutic use ; Animals ; Asthma/drug therapy/*immunology/pathology ; Bronchial Hyperreactivity/*drug therapy/metabolism ; Hypoxia-Inducible Factor 1, alpha Subunit/*metabolism ; Mice ; NF-kappa B/*metabolism ; Ovalbumin/immunology ; Reactive Oxygen Species/*metabolism ; Vascular Endothelial Growth Factor A/metabolism