OBJECTIVES: To investigate the targets and mechanisms of 7-hydroxyethyl chrysin (7-HEC) in prevention and treatment of high-altitude cerebral edema (HACE) in rats. METHODS: Fifty-four male Wistar rats were randomly divided into normal control group, HACE model group, and 7-HEC-treated group (18 rats in each group). Except for the normal control group, rats in the two other groups were exposed to a hypobaric hypoxic chamber simulating a 7000 m altitude for 72 h to establish the HACE model. The 7-HEC-treated group was intraperitoneally injected with 7-HEC (150 mg·kg^－¹·d^－¹) for 3 consecutive days before modeling, while the model group received equivalent isotonic sodium chloride solution. Tandem Mass Tag (TMT) proteomics technology was used to detect differentially expressed proteins (DEPs) with screening criteria set at a fold change >1.2 and P<0.05. Western blotting was used to verify the expression levels of target proteins. Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and protein-protein interaction (PPI) network analysis were performed. RESULTS: Compared with the normal control group, 256 DEPs were identified in the HACE model group. Compared with the HACE model group, 87 DEPs were identified in the 7-HEC-treated group. Among them, 19 DEPs that were dysregulated in the HACE model group were restored after 7-HEC intervention, of which seven (HSPA4, Arhgap20, SERT, HACL1, CCDC43, POLR3A, and PCBD1) were confirmed by Western blotting. GO enrichment analysis of the DEPs between the HACE model and 7-HEC-treated groups revealed their involvement in 13 biological processes, five cellular components, and two molecular functions. KEGG pathway analysis indicated associations with the mRNA surveillance pathway, Th17 cell differentiation, serotonergic synapse, RNA polymerase, protein processing in the endoplasmic reticulum, peroxisome, neuroactive ligand-receptor interaction, folate biosynthesis. PPI network analysis demonstrated that HSPA4, POLR3A, and HACL1, which were validated by Western blotting, interacted with multiple signaling pathways and ranked among the top 20 hub proteins by degree value, suggesting their potential role as core regulatory factors. Arhgap20, SERT and PCBD1 also exhibited interactions with several proteins, suggesting their potential as key regulatory proteins, whereas no interactions for CCDC43 were identified. CONCLUSIONS This study applied TMT proteomics to identify seven potential therapeutic targets of 7-HEC for the prevention and treatment of HACE. These targets may be involved in the pathogenesis of HACE through multiple pathways, including maintaining cellular homeostasis, ameliorating oxidative stress, regulating energy metabolism, and reducing vascular permeability.
Animals ; Male ; Proteomics/methods* ; Rats, Wistar ; Flavonoids/therapeutic use* ; Rats ; Brain Edema/etiology* ; Altitude Sickness/metabolism* ; Protein Interaction Maps

OBJECTIVE: High-altitude hypoxia exposure often damages hippocampus-dependent learning and memory. Nogo-A is an important axonal growth inhibitory factor. However, its function in high-altitude hypoxia and its mechanism of action remain unclear. METHODS: In an in vivo study, a low-pressure oxygen chamber was used to simulate high-altitude hypoxia, and genetic or pharmacological intervention was used to block the Nogo-A/NgR1 signaling pathway. Contextual fear conditioning and Morris water maze behavioral tests were used to assess learning and memory in rats, and synaptic damage in the hippocampus and changes in oxidative stress levels were observed. In vitro, SH-SY5Y cells were used to assess oxidative stress and mitochondrial function with or without Nogo-A knockdown in Oxygen Glucose-Deprivation/Reperfusion (OGD/R) models. RESULTS: Exposure to acute high-altitude hypoxia for 3 or 7 days impaired learning and memory in rats, triggered oxidative stress in the hippocampal tissue, and reduced the dendritic spine density of hippocampal neurons. Blocking the Nogo-A/NgR1 pathway ameliorated oxidative stress, synaptic damage, and the learning and memory impairment induced by high-altitude exposure. CONCLUSION: Our results demonstrate the detrimental role of Nogo-A protein in mediating learning and memory impairment under high-altitude hypoxia and suggest the potential of the Nogo-A/NgR1 signaling pathway as a crucial therapeutic target for alleviating learning and memory dysfunction induced by high-altitude exposure. GRAPHICAL ABSTRACT available in www.besjournal.com.
Animals ; Oxidative Stress ; Hippocampus/metabolism* ; Rats ; Nogo Proteins/genetics* ; Male ; Rats, Sprague-Dawley ; Hypoxia/metabolism* ; Altitude ; Synapses ; Humans ; Altitude Sickness/metabolism*

Objective To evaluate the value of pre-ascent 6-minute walking test performed at a high altitude in predicting the incidence of acute mountain sickness(AMS)induced by rapid ascent to a very high altitude.Methods After baseline information was collected,participants completed the 6-minute walking test at a high altitude of 2 900 m.Then,they rapidly ascended to a very high altitude of 5 000 m.The Lake Louise score was recorded to assess AMS.Results The AMS group showed a shorter pre-ascent 6-minute walking distance(6MWD)at the high altitude than the non-AMS group[480.00(450.00,521.75)m vs.546.00(516.50,568.50)m,P=0.006].No difference was observed regarding the pre-ascent heart rate or peripheral oxygen saturation(both P>0.05).The pre-ascent 6MWD at the high altitude was negatively correlated with the Lake Louise score assessed after rapid ascent to the very high altitude(r=-0.497,P=0.012).Logistic regression analysis confirmed that the pre-ascent 6MWD at the high altitude was associated with the risk of AMS induced by rapid ascent to the very high altitude(OR=0.971,95% CI=0.947-0.996,P=0.022).The results indicated that the pre-ascent 6MWD demonstrated ideal prediction performance(area under receiver operating characteristic curve=0.846,P=0.006).Conclusion The pre-ascent 6MWD recorded at the high altitude is a convenient and reliable predictor of the AMS induced by rapid ascent to the very high altitude.
Humans ; Altitude Sickness/diagnosis* ; Male ; Adult ; Female ; Young Adult ; Middle Aged ; Acute Disease ; Walk Test ; Walking ; Altitude ; Exercise Test

OBJECTIVE: To explore the pathogenesis of erythrocytosis by detecting the key enzymes of glucose metabolism and glucose transporter in bone marrow erythrocytes of chronic mountain sickness (CMS), and analyzing its correlation with hemoglobin. METHODS: Twenty CMS patients hospitalized in Qinghai Provincial People's Hospital from January 2019 to December 2020 were selected as CMS group. Twenty males with leukocyte count > 3.5×10⁹/L who had accepted bone marrow aspiration and had normal result were taken as control group. The mRNA and protein expression of key enzymes and glucose transporter in glucose metabolism in bone marrow CD71⁺ erythrocytes were detected by real time qPCR and Western blot, respectively. Glucose, lactic acid and 2,3-diphosphoglycerate in the bone marrow supernatant and serum were tested by ELISA. The mRNA and protein expression of key enzymes and glucose transporter, glucose, lactic acid and 2,3-diphosphoglycerate of the two groups were compared. Pearson correlation was used to analyze the correlation between key enzymes, glucose transporter in glucose metabolism in bone marrow CD71⁺ erythrocytes and hemoglobin. RESULTS: The expression of HK2, GLUT1 and GLUT2 mRNA in the CMS group were higher than those in the control group (P<0.001), while the expression of HK1, OGDH and COX5B mRNA were not different. The expression of HK2, GLUT1 and GLUT2 protein in the CMS group were higher than those in the control group (P<0.05). The levels of glucose and lactic acid in the bone marrow supernatant and serum in the CMS group were not different from those in the control group, while the level of 2,3-diphosphoglycerate was higher (P<0.001). Both HK2 and GLUT2 proteins were positively correlated with hemoglobin (r=0.511, 0.717). CONCLUSION CMS patients may increase glycolysis by increasing the expression of HK2, and promote the utilization of glucose through high expression of GLUT1 and GLUT2 to meet the need of energy supply.
Male ; Humans ; Altitude Sickness/metabolism* ; Glucose Transporter Type 1 ; 2,3-Diphosphoglycerate ; Hemoglobins ; Chronic Disease ; RNA, Messenger ; Phenotype ; Glucose

Acute mountain sickness (AMS) is a clinical syndrome of multi-system physiological disorder after acute exposure to low pressure and low oxygen at high altitude. Quantitative proteomics can systematically quantify and describe protein composition and dynamic changes. In recent years, quantitative proteomics has been widely used in the prevention, diagnosis, treatment and pathogenesis of many diseases. This review summarizes the progress of quantitative proteomics techniques and its application in the prevention, diagnosis, treatment of AMS and mechanisms of rapidly acclimatizing to plateau, in order to provide a reference for the pathogenesis, early intervention, clinical treatment and proteomic research of AMS.
Humans ; Altitude Sickness/prevention & control* ; Proteomics ; Acute Disease ; Oxygen/metabolism*

OBJECTIVES: The plateau environment is characterized by low oxygen partial pressure, leading to the reduction of oxygen carrying capacity in alveoli and the reduction of available oxygen in tissues, and thus causing tissue damage. Cilostazol is a phosphodiesterase III inhibitor that has been reported to increase the oxygen release of hemoglobin (Hb) in tissues. This study aims to explore the anti-hypoxic activity of cilostazol and its anti-hypoxic effect. METHODS: A total of 40 male BALB/C mice were randomly divided into a low-dose cilostazol (6.5 mg/kg) group, a medium-dose (13 mg/kg) group, a high-dose (26 mg/kg) group, and a control group. The atmospheric airtight hypoxia experiment was used to investigate the anti-hypoxic activity of cilostazol and to screen the optimal dosage. Twenty-four male Wistar rats were randomly divided into a normoxia control group, a hypoxia model group, an acetazolamide (22.33 mg/kg) group, and a cilostazol (9 mg/kg) group. After 3 days of hypoxia in the 4 010 m high altitude, blood from the abdominal aorta was collected to determine blood gas indicators, the levels of IL-6 and TNF-α in plasma were determined by enzyme-linked immunosorbent assay, and the levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutataione (GSH) were measured. The degree of pathological damage for rat tissues was observed with HE staining. RESULTS: Compared with the control group, the survival time of mice in the low, medium, and high dose group of cilostazol was significantly prolonged, and the survival time of mice in the medium dose group was the longest, with an extension rate at 29.34%, so the medium dose was the best dose. Compared with the hypoxia model group, the P50 (oxygen partial pressure at Hb oxygen saturation of 50%) value of rats in the cilostazol group was significantly increased by 1.03%; Hb and Hct were significantly reduced by 8.46% and 8.43%, and the levels of IL-6 and TNF-α in plasma were reduced by 50.65% and 30.77%. The MDA contents in heart, brain, lung, liver, and kidney tissues were reduced by 37.12%, 29.55%, 25.00%, 39.34%, and 21.47%, respectively. The SOD activities were increased by 94.93%, 9.14%, 9.42%, 13.29%, and 20.80%, respectively. The GSH contents were increased by 95.24%, 28.62%, 28.57%, 20.80%, and 44.00%, respectively. The results of HE staining showed that compared with the hypoxia model group, cilostazol significantly improved the damage of heart, lung, and kidney tissues in rats after hypoxia. CONCLUSIONS Cilostazol can significantly improve the oxidative stress and inflammatory reaction caused by rapid altitude hypoxia, and it has a significant protective effect on tissue damage caused by hypoxia, suggesting that it has obvious anti-hypoxic activity.
Altitude Sickness ; Animals ; Cilostazol/therapeutic use* ; Hypoxia/drug therapy* ; Interleukin-6/pharmacology* ; Male ; Mice ; Mice, Inbred BALB C ; Oxidative Stress ; Oxygen ; Rats ; Rats, Wistar ; Superoxide Dismutase/metabolism* ; Tumor Necrosis Factor-alpha/pharmacology*

Objective: To investigate the gene expression characteristics of peripheral blood mononuclear cells from patients with high altitude pulmonary hypertension (HAPH) in Naxi residents living in Lijiang, Yunnan, and to explore the underlying pathogenesis and value for potential drug selection. Methods: This is a case-control study. Six patients with HPAH (HPAH group) and 4 normal subjects (control group) were selected from the Naxi residents who originally lived in Lijiang, Yunnan Province. The general clinical data of the two groups were collected, and the related indexes of pulmonary artery pressure were collected. Peripheral blood mononuclear cells of the subjects were collected for RNA sequencing. The differences on gene expression, regulatory network of transcription factors and drug similarity between the two groups were compared. The results were compared with the public data of idiopathic pulmonary arterial hypertension (IPAH). Biological processes and signal pathways were analyzed and compared between HPAH and IPAH patients. Results: The age of 6 patients with HAPH was (68.1±8.3) years old, and there were 2 males (2/6). The age of 4 subjects in the control group was (62.3±10.9) years old, and there were 2 males (2/4). Tricuspid regurgitation velocity, tricuspid pressure gradient and pulmonary systolic pressure in HAPH group were significantly higher than those in control group (all P<0.05). The results of RNA sequencing showed that compared with the control group, 174 genes were significantly upregulated and 169 genes were downregulated in peripheral blood mononuclear cells of HAPH group. These differentially expressed genes were associated with 220 biological processes, 52 molecular functions and 23 cell components. A total of 21 biological processes and 2 signal pathways differed between HPAH and IPAH groups, most of which were related to inflammation and immune response. ZNF384, SP1 and STAT3 were selected as highly correlated transcription factors by transcription factor prediction analysis. Trichostatin A and vorinostat were screened out as potential drugs for the treatment of HAPH by drug similarity analysis. Conclusions: There are significant differences in gene expression in peripheral blood monocytes between HAPH patients and normal population, and inflammation and immune dysfunction are the main pathogenic factors. Trichostatin A and Vorinostat are potential drugs for the treatment of HAPH.
Aged ; Altitude ; Altitude Sickness/genetics* ; Case-Control Studies ; China ; Familial Primary Pulmonary Hypertension/genetics* ; Humans ; Hydroxamic Acids/therapeutic use* ; Hypertension, Pulmonary/genetics* ; Inflammation ; Leukocytes, Mononuclear/pathology* ; Male ; Middle Aged ; Transcription Factors ; Transcriptome/genetics* ; Vorinostat/therapeutic use*

Altitude ; Altitude Sickness ; Animals ; Hypoxia ; Iron ; Mice ; Spleen

Adult ; Altitude Sickness ; Arousal ; Electroencephalography ; Emotions ; Humans ; Hypoxia ; Male ; Young Adult

Objective To examine if the variations at sea level would be able to predict subsequent susceptibility to acute altitude sickness in subjects upon a rapid ascent to high altitude. Methods One hundred and six Han nationality male individuals were recruited to this research. Dynamic electrocardiogram, treadmill exercise test, echocardiography, routine blood examination and biochemical analysis were performed when subjects at sea level and entering the plateau respectively. Then multiple regression analysis was performed to construct a multiple linear regression equation using the Lake Louise Score as dependent variable to predict the risk factors at sea level related to acute mountain sickness (AMS). Results Approximately 49.05% of the individuals developed AMS. The tricuspid annular plane systolic excursion (22.0±2.66 vs. 23.2±3.19 mm, t=1.998, P=0.048) was significantly lower in the AMS group at sea level, while count of eosinophil [(0.264±0.393)×10⁹/L vs. (0.126±0.084)×10⁹/L, t=-2.040, P=0.045], percentage of differences exceeding 50 ms between adjacent normal number of intervals (PNN50, 9.66%±5.40% vs. 6.98%±5.66%, t=-2.229, P=0.028) and heart rate variability triangle index (57.1±16.1 vs. 50.6±12.7, t=-2.271, P=0.025) were significantly higher. After acute exposure to high altitude, C-reactive protein (0.098±0.103 vs. 0.062±0.045 g/L, t=-2.132, P=0.037), aspartate aminotransferase (19.7±6.72 vs. 17.3±3.95 U/L, t=-2.231, P=0.028) and creatinine (85.1±12.9 vs. 77.7±11.2 mmol/L, t=-3.162, P=0.002) were significantly higher in the AMS group, while alkaline phosphatase (71.7±18.2 vs. 80.6±20.2 U/L, t=2.389, P=0.019), standard deviation of normal-to-normal RR intervals (126.5±35.9 vs. 143.3±36.4 ms, t=2.320, P=0.022), ejection time (276.9±50.8 vs. 313.8±48.9 ms, t=3.641, P=0.001) and heart rate variability triangle index (37.1±12.9 vs. 41.9±11.1, t=2.020, P=0.047) were significantly lower. Using the Lake Louise Score as the dependent variable, prediction equation were established to estimate AMS: Lake Louise Score=3.783+0.281×eosinophil-0.219×alkaline phosphatase+0.032×PNN50. Conclusions We elucidated the differences of physiological variables as well as noninvasive cardiovascular indicators for subjects after high altitude exposure compared with those at sea level. We also created an acute high altitude reaction early warning equation based on the physiological variables and noninvasive cardiovascular indicators at sea level.
Acute Disease ; Adolescent ; Adult ; Alkaline Phosphatase/blood* ; Altitude ; Altitude Sickness/physiopathology* ; Aspartate Aminotransferases/blood* ; Blood Pressure/physiology* ; C-Reactive Protein/analysis* ; Creatinine/blood* ; Electrocardiography/methods* ; Exercise Test/methods* ; Heart Rate/physiology* ; Humans ; Leukocyte Count ; Male ; Risk Factors ; Young Adult