Alterations of Human Plasma Proteome Profile on Adaptation to High-Altitude Hypobaric Hypoxia

Neoadjuvant immunotherapy plus chemotherapy in high altitude natives with resectable esophageal squamous cell carcinoma in Tibet

BACKGROUD

Neoadjuvant therapy followed by surgery has been proved to improve the survival of patients with ESCC, and neoadjuvant chemoradiotherapy (nCRT) is the standard of care in most areas of the world. However, multimodality therapy including radiation therapy is actually limited in the current treatment of esophageal cancer in Tibet. The role of neoadjuvant immunotherapy in resectable esophageal cancer has been assessed in multiple phase II clinical trials, but there's lack of evidence of applying neoadjuvant immunotherapy plus chemotherapy in Tibetan residents.

METHODS

Patients with previously treatment-naïve, resectable ESCC were included in this study. The preoperative treatment regimen included Tislelizumab, nab-paclitaxel and carboplatin. Surgery was planned for every patient who completed neoadjuvant treatment. Surgical approaches and extent of esophageal resection was chosen depended on tumor location.

RESULTS

23 patients with resectable ESCC were included from January 2022 to May 2024 in this study. Among all patients, 5 (21.7 %) had thyroid nodules or dysfunction. 19 of 23 (82.6 %) patients finished 2-3 cycles of treatment. 19 (82.6 %) patients experienced treatment-related adverse events (TRAEs), with 11 (47.8 %) patients experiencing grade 3-4 TRAEs. Thyroid toxicity of grade 1-2 was observed in 12 (52.2 %) patients. The objective response rate (ORR) was 69.6 %, and the disease control rate (DCR) was 100 %.。14 (60.9 %) of 23 patients underwent surgery. All patients underwent R0 resection. The pCR rate was 21.4 %. The median follow-up was 22.4 months. During the follow-up period, there were no recurrences, but 3 patients died due to non-tumor-related causes.

CONCLUSION

Esophagectomy following neoadjuvant immunotherapy plus chemotherapy appears to be safe and feasible in high altitude natives with resectable esophageal squamous cell carcinoma in Tibet.

A bovine model of hypoxia-induced pulmonary hypertension reveals a gradient of immune and matrisome response with a complement signature found in circulation

Pulmonary hypertension (PH) is a progressive vascular disease characterized by vascular remodeling, stiffening, and luminal obstruction, driven by dysregulated cell proliferation, inflammation, and extracellular matrix (ECM) alterations. Despite the recognized contribution of ECM dysregulation to PH pathogenesis, the precise molecular alterations in the matrisome remain poorly understood. In this study, we employed a matrisome-focused proteomics approach to map the protein composition in a young bovine calf model of acute hypoxia-induced PH. Our findings reveal distinct alterations in the matrisome along the pulmonary vascular axis, with the most prominent changes observed in the main pulmonary artery. Key alterations included a strong immune response and wound repair signature, characterized by increased levels of complement components, coagulation cascade proteins, and provisional matrix markers. In addition, we observed upregulation of ECM-modifying enzymes, growth factors, and core ECM proteins implicated in vascular stiffening, such as collagens, periostin, tenascin-C, and fibrin(ogen). Notably, these alterations correlated with increased mean pulmonary arterial pressure and vascular remodeling. In the plasma, we identified increased levels of complement components, indicating a systemic inflammatory response accompanying the vascular remodeling. Our findings shed light on the dynamic matrisome remodeling in early-stage PH, implicating a wound-healing trajectory with distinct patterns from the main pulmonary artery to the distal vasculature. This study provides novel insights into the immune cell infiltration and matrisome alterations associated with PH pathogenesis and highlights potential biomarkers and therapeutic targets within the matrisome landscape.NEW & NOTEWORTHY Extensive immune cell infiltration and matrisome alterations associated with hypoxia-induced pulmonary hypertension in a large mammal model. Matrisome components correlate with increased resistance to identify candidate alterations that drive biomechanical manifestations of the disease.

Gender-specific association between blood cell parameters and hyperuricemia in high-altitude areas

Background

Hyperuricemia is a common metabolic disorder linked to various health conditions. Its prevalence varies among populations and genders, and high-altitude environments may contribute to its development. Understanding the connection between blood cell parameters and hyperuricemia in high-altitude areas can shed light on the underlying mechanisms. This study aimed to investigate the relationship between blood cell parameters and hyperuricemia in high-altitude areas, with a particular focus on gender differences.

Methods

We consecutively enrolled all eligible Tibetan participants aged 18-60 who were undergoing routine medical examinations at the People's Hospital of Chaya County between January and December 2022. During this period, demographic and laboratory data were collected to investigate the risk factors associated with hyperuricemia.

Results

Among the participants, 46.09% were diagnosed with hyperuricemia. In the male cohort, significant correlations were found between serum uric acid (SUA) levels and red blood cell (RBC) count, creatinine (Cr). Urea, alanine transaminase (ALT), and albumin (ALB). Notably, RBC exhibited the strongest association. Conversely, in the female cohort, elevated SUA levels were associated with factors such as white blood cell (WBC) count. Urea, ALT, and ALB, with WBC demonstrating the most significant association. Further analysis within the female group revealed a compelling relationship between SUA levels and specific white blood cell subtypes, particularly neutrophils (Neu).

Conclusion

This study revealed gender-specific associations between SUA levels and blood cell parameters in high-altitude areas. In males, RBC count may play a role in hyperuricemia, while in females, WBC count appears to be a significant factor. These findings contribute to our understanding of metabolic dynamics in high-altitude regions but require further research for comprehensive mechanistic insights.

Proteomic analysis of plasma proteins from patients with cardiac rupture after acute myocardial infarction using TMT-based quantitative proteomics approach

BACKGROUND

Cardiac rupture (CR) is a rare but catastrophic mechanical complication of acute myocardial infarction (AMI) that seriously threatens human health. However, the reliable biomarkers for clinical diagnosis and the underlying signaling pathways insights of CR has yet to be elucidated.

METHODS

In the present study, a quantitative approach with tandem mass tag (TMT) labeling and liquid chromatography-tandem mass spectrometry was used to characterize the differential protein expression profiles of patients with CR. Plasma samples were collected from patients with CR (n = 37), patients with AMI (n = 47), and healthy controls (n = 47). Candidate proteins were selected for validation by multiple reaction monitoring (MRM) and enzyme-linked immunosorbent assay (ELISA).

RESULTS

In total, 1208 proteins were quantified and 958 differentially expressed proteins (DEPs) were identified. The difference in the expression levels of the DEPs was more noticeable between the CR and Con groups than between the AMI and Con groups. Bioinformatics analysis showed most of the DEPs to be involved in numerous crucial biological processes and signaling pathways, such as RNA transport, ribosome, proteasome, and protein processing in the endoplasmic reticulum, as well as necroptosis and leukocyte transendothelial migration, which might play essential roles in the complex pathological processes associated with CR. MRM analysis confirmed the accuracy of the proteomic analysis results. Four proteins i.e., C-reactive protein (CRP), heat shock protein beta-1 (HSPB1), vinculin (VINC) and growth/differentiation factor 15 (GDF15), were further validated via ELISA. By receiver operating characteristic (ROC) analysis, combinations of these four proteins distinguished CR patients from AMI patients with a high area under the curve (AUC) value (0.895, 95% CI, 0.802-0.988, p < 0.001).

CONCLUSIONS

Our study highlights the value of comprehensive proteomic characterization for identifying plasma proteome changes in patients with CR. This pilot study could serve as a valid foundation and initiation point for elucidation of the mechanisms of CR, which might aid in identifying effective diagnostic biomarkers in the future.

Thrombotic Alterations under Perinatal Hypoxic Conditions: HIF and Other Hypoxic Markers

Hypoxia is considered to be a stressful physiological condition, which may occur during labor and the later stages of pregnancy as a result of, among other reasons, an aged placenta. Therefore, when gestation or labor is prolonged, low oxygen supply to the tissues may last for minutes, and newborns may present breathing problems and may require resuscitation maneuvers. As a result, poor oxygen supply to tissues and to circulating cells may last for longer periods of time, leading to life-threatening conditions. In contrast to the well-known platelet activation that occurs after reperfusion of the tissues due to an ischemia/reperfusion episode, platelet alterations in response to reduced oxygen exposition following labor have been less frequently investigated. Newborns overcome temporal hypoxic conditions by changing their organ functions or by adaptation of the intracellular molecular pathways. In the present review, we aim to analyze the main platelet modifications that appear at the protein level during hypoxia in order to highlight new platelet markers linked to complications arising from temporal hypoxic conditions during labor. Thus, we demonstrate that hypoxia modifies the expression and activity of hypoxic-response proteins (HRPs), including hypoxia-induced factor (HIF-1), endoplasmic reticulum oxidase 1 (Ero1), and carbonic anhydrase (CIX). Finally, we provide updates on research related to the regulation of platelet function due to HRP activation, as well as the role of HRPs in intracellular Ca2+ homeostasis.

iHypoxia: An Integrative Database of Protein Expression Dynamics in Response to Hypoxia in Animals

Mammals have evolved mechanisms to sense hypoxia and induce hypoxic responses. Recently, high-throughput techniques have greatly promoted global studies of protein expression changes during hypoxia and the identification of candidate genes associated with hypoxia-adaptive evolution, which have contributed to the understanding of the complex regulatory networks of hypoxia. In this study, we developed an integrated resource for the expression dynamics of proteins in response to hypoxia (iHypoxia), and this database contains 2589 expression events of 1944 proteins identified by low-throughput experiments (LTEs) and 422,553 quantitative expression events of 33,559 proteins identified by high-throughput experiments from five mammals that exhibit a response to hypoxia. Various experimental details, such as the hypoxic experimental conditions, expression patterns, and sample types, were carefully collected and integrated. Furthermore, 8788 candidate genes from diverse species inhabiting low-oxygen environments were also integrated. In addition, we conducted an orthologous search and computationally identified 394,141 proteins that may respond to hypoxia among 48 animals. An enrichment analysis of human proteins identified from LTEs shows that these proteins are enriched in certain drug targets and cancer genes. Annotation of known posttranslational modification (PTM) sites in the proteins identified by LTEs reveals that these proteins undergo extensive PTMs, particularly phosphorylation, ubiquitination, and acetylation. iHypoxia provides a convenient and user-friendly method for users to obtain hypoxia-related information of interest. We anticipate that iHypoxia, which is freely accessible at https://ihypoxia.omicsbio.info, will advance the understanding of hypoxia and serve as a valuable data resource.

Quantify retinal structure in high-altitude residents with and without high altitude polycythemia

BACKGROUND

To assess retinal structural parameters in high-altitude (HA) residents with and without high altitude polycythemia (HAPC) and to elucidate the relationship between retinal structural parameters and hemoglobin (HGB).

METHODS

This cross-sectional study included 55 HAPC patients and 52 healthy HA residents. Retinal structural parameters included retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) parameters and retinal vessel diameter. RNFL thickness were acquired from spectral domain optical coherence tomography (SD-OCT) built-in software. ONH parameters including neuroretina rim height, cup area, disc area and vertical cup/disc ratio were obtained by OCT built-in software and ImageJ software. Retinal vessel measurements including central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE) and AVR (artery/vein ratio) were calculated by revised formulas for summarizing retinal vessel diameters. All parameters were compared between HAPC group versus healthy HA group. The associations between retinal parameters and HGB were assessed by Pearson correlation analyses.

RESULTS

In comparison of HAPC group versus healthy HA group, RNFL thickness was thicker in the nasal quadrant of the optic disc in HAPC group (74.82 ± 14.4 VS. 66.06 ± 13.71 μm, P = 0.002). Bigger disc area and bigger cup area were also observed in HAPC group (all P < 0.05). Meanwhile, the value of CRVE was higher in HAPC group which suggested that retinal veins dilated significantly in HAPC patients (P < 0.001), however, CRAE and AVR were comparable between groups. Pearson analyses revealed that HGB was positive correlated with CRVE in HAPC group (r = 0.469, P = 0.003).

CONCLUSIONS

long-term HA exposure secondary HAPC could result in thickened RNFL, enlarged ONH and dilated retinal veins. Moreover, increased blood viscosity caused by HGB should be responsible for dilated veins, but not for thickened RNFL and enlarged ONH. This study deepens the understanding of the impact of HA environment on retina.

Identification of Suitable Reference Genes for Lowlanders Exposed to High Altitude and Ladakhi Highlanders

Sharma, Vandana, Rajeev Varshney, and Niroj Kumar Sethy. Identification of suitable reference genes for lowlanders exposed to high altitude and Ladakhi highlanders. High Alt Med Biol. 23:319-329, 2022. Background: Identifying a stable and reliable reference gene (RG) is a prerequisite for the unbiased and unambiguous analysis of gene expression data. It has become evident that conventionally used housekeeping genes such as beta-actin (ACTB), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and peptidylprolyl Isomerase A (PPIA) exhibit varied expression patterns under hypoxia. Hence, the identification of stable RGs for humans exposed to hypobaric hypoxia can enhance the accuracy of gene expression studies by limiting the negligent use of random housekeeping genes. Methods: Using TaqMan™ array-based quantitative real-time quantitative polymerase chain reaction, we evaluated the expression of 32 commonly used human RGs among lowlanders at Delhi (altitude 216 m, SL), lowlanders at Leh (altitude 3,524 m) after 1 day (HA-D1) and 7 days (HA-D7), as well as indigenous Ladakhi highlanders at the same altitude. The expression stability of the RGs was evaluated using geNorm, NormFinder, BestKeeper, Delta CT method, and RefFinder algorithms. Results: Our studies identify TATA-box binding protein (TBP), proteasome 26S subunit, ATPase 4 (PSMC4), and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ) as the most stable human RGs for normalizing human gene expression under hypobaric hypoxia. In addition, we report the combination of TBP and cyclin-dependent kinase inhibitor 1B (CDKN1B) as the most stable RG for studying lowlander gene expression during high-altitude exposure. In contrast, RPL30 and 18S exhibited maximum variation across study groups and were identified as the least stable RGs.

GDF11 Regulates PC12 Neural Stem Cells via ALK5-Dependent PI3K-Akt Signaling Pathway

Growth differentiation factor 11 (GDF11), belonging to the transforming factor-β superfamily, regulates anterior-posterior patterning and inhibits neurogenesis during embryonic development. However, recent studies recognized GDF11 as a rejuvenating (or anti-ageing) factor to reverse age-related cardiac hypertrophy, repair injured skeletal muscle, promote cognitive function, etc. The effects of GDF11 are contradictory and the mechanism of action is still not well clarified. The objective of the present study was to investigate effects of GDF11 on PC12 neural stem cells in vitro and to reveal the underlying mechanism. We systematically assessed the effects of GDF11 on the life activities of PC12 cells. GDF11 significantly suppressed cell proliferation and migration, promoted differentiation and apoptosis, and arrested cell cycle at G2/M phase. Both TMT-based proteomic analysis and phospho-antibody microarray revealed PI3K-Akt pathway was enriched when treated with GDF11. Inhibition of ALK5 or PI3K obviously attenuated the effects of GDF11 on PC12 neural stem cells, which exerted that GDF11 regulated neural stem cells through ALK5-dependent PI3K-Akt signaling pathway. In summary, these results demonstrated GDF11 could be a negative regulator for neurogenesis via ALK5 activating PI3K-Akt pathway when it directly acted on neural stem cells.

Time Domains of Hypoxia Responses and -Omics Insights

The ability to respond rapidly to changes in oxygen tension is critical for many forms of life. Challenges to oxygen homeostasis, specifically in the contexts of evolutionary biology and biomedicine, provide important insights into mechanisms of hypoxia adaptation and tolerance. Here we synthesize findings across varying time domains of hypoxia in terms of oxygen delivery, ranging from early animal to modern human evolution and examine the potential impacts of environmental and clinical challenges through emerging multi-omics approaches. We discuss how diverse animal species have adapted to hypoxic environments, how humans vary in their responses to hypoxia (i.e., in the context of high-altitude exposure, cardiopulmonary disease, and sleep apnea), and how findings from each of these fields inform the other and lead to promising new directions in basic and clinical hypoxia research.

Plateau Adaptation Gene Analyses Reveal Transcriptomic, Proteomic, and Dual Omics Expression in the Lung Tissues of Tibetan and Yorkshire Pigs

Elevated environments such as plateaus are often classified as low oxygen environments. The hypoxic adaptation mechanisms utilized by organisms in these conditions are not well understood. To address this, the differentially expressed genes (DEGs) involved in hypoxia adaptation were assessed using two pig breeds (Tibetan pig [TP] and Yorkshire sow [YY]). Genes related to lung tissue responses to hypoxia were assessed using transcriptomic (using RNA-seq) and proteomic (using iTRAQ) analysis. A total of 1021 DEGs were screened out. In the iTRAQ omics data, a total of 22,100 peptides were obtained and 4518 proteins were found after filtering. A total of 271 differentially expressed proteins [DEPs] were screened using the conditions of p < 0.05; FC ≤ 0.833; and FC ≥ 1.2. A total of 14 DEGs at the mRNA and protein levels were identified and found to be associated with regulation of the inflammatory response; blood particles; and MAPK cascade response regulation. Among the DEGs, six were associated with hypoxia adaptation function (mitochondria and glycolysis) in pigs. The results of this study identify novel candidate genes involved in porcine hypoxia adaptation mechanisms.

Human adaptation to high altitude: a review of convergence between genomic and proteomic signatures

Both genomics- and proteomics-based investigations have identified several essential genes, proteins, and pathways that may facilitate human adaptive genotype/phenotype in a population-specific manner. This comprehensive review provides an up-to-date list of genes and proteins identified for human adaptive responses to high altitudes. Genomics studies for indigenous high-altitude populations like Tibetans, Andeans, Ethiopians, and Sherpas have identified 169 genes under positive natural selection. Similarly, global proteomics studies have identified 258 proteins (± 1.2-fold or more) for Tibetan, Sherpa, and Ladakhi highlanders. The primary biological processes identified for genetic signatures include hypoxia-inducible factor (HIF)-mediated oxygen sensing, angiogenesis, and erythropoiesis. In contrast, major biological processes identified for proteomics signatures include 14–3-3 mediated sirtuin signaling, integrin-linked kinase (ILK), phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT), and integrin signaling. Comparing genetic and protein signatures, we identified 7 common genes/proteins (HBB/hemoglobin subunit beta, TF/serotransferrin, ANGPTL4/angiopoietin-related protein 4, CDC42/cell division control protein 42 homolog, GC/vitamin D-binding protein, IGFBP1/insulin-like growth factor-binding protein 1, and IGFBP2/insulin-like growth factor-binding protein 2) involved in crucial molecular functions like IGF-1 signaling, LXR/RXR activation, ferroptosis signaling, iron homeostasis signaling and regulation of cell cycle. Our combined multi-omics analysis identifies common molecular targets and pathways for human adaptation to high altitude. These observations further corroborate convergent positive selection of hypoxia-responsive molecular pathways in humans and advocate using multi-omics techniques for deciphering human adaptive responses to high altitude.

Proteomic and clinical biomarkers for acute mountain sickness in a longitudinal cohort

Ascending to high-altitude by non-high-altitude natives is a well-suited model for studying acclimatization to extreme environments. Acute mountain sickness (AMS) is frequently experienced by visitors. The diagnosis of AMS mainly depends on a self-questionnaire, revealing the need for reliable biomarkers for AMS. Here, we profiled 22 AMS symptom phenotypes, 65 clinical indexes, and plasma proteomic profiles of AMS via a combination of proximity extension assay and multiple reaction monitoring of a longitudinal cohort of 53 individuals. We quantified 1069 proteins and validated 102 proteins. Via differential analysis, machine learning, and functional association analyses. We found and validated that RET played an important role in the pathogenesis of AMS. With high-accuracies (AUCs > 0.9) of XGBoost-based models, we prioritized ADAM15, PHGDH, and TRAF2 as protective, predictive, and diagnostic biomarkers, respectively. Our findings shed light on the precision medicine for AMS and the understanding of acclimatization to high-altitude environments.

Disclosing targets and pharmacological mechanisms of total bioflavonoids extracted from Selaginella doederleinii against non-small cell lung cancer by combination of network pharmacology and proteomics

ETHNOPHARMACOLOGICAL RELEVANCE

Previously, the total bioflavonoids extract from Selaginella doederleinii (SDTBE) presented favorable in vitro and in vivo activities against non-small cell lung cancer (NSCLC), hinting at its medicinal potential. However, up to nowadays, targets and integrative action mechanisms of SDTBE are still not very clear, which presents an obstacle to the development of herbal medicine.

AIM OF THE STUDY

The present study aimed to disclose the potential targets and integrative action mechanism of SDTBE against NSCLC.

MATERIALS AND METHODS

A system pharmacology-based strategy including target fishing, network pharmacology analysis and molecular docking were applied to predict the potential targets and pathways for the seven main active ingredients in SDTBE. A proteomics study was subsequently performed for validating the affected pathways and possible targets. Western blot assay, mouse xenograft tumor model and immunofluorescence assays were used to further confirm the key targets and integrative action mechanisms of SDTBE against NSCLC.

RESULTS

By system pharmacology, it was inferred that SDTBE could mainly act on mitogen-activated protein kinase (MAPK) and PI3K-AKT signaling pathways by targeting epidermal growth factor receptor (EGFR), protein kinase B (AKT) and mitogen-activated or extracellular signal-regulated protein kinase (MEK), which was validated by proteomics results, and further confirmed in vitro and in vivo by Western blot and immunofluorescence assays.

CONCLUSION

SDTBE targeting multi-targets including EGFR, AKT and MEK could exert its anti-NSCLC effect mainly via MAPK and PI3K-AKT signaling pathways.

Mechanobiological Implications of Cancer Progression in Space

The human body is normally adapted to maintain homeostasis in a terrestrial environment. The novel conditions of a space environment introduce challenges that changes the cellular response to its surroundings. Such an alteration causes physical changes in the extracellular microenvironment, inducing the secretion of cytokines such as interleukin-6 (IL-6) and tumor growth factor-β (TGF-β) from cancer cells to enhance cancer malignancy. Cancer is one of the most prominent cell types to be affected by mechanical cues via active interaction with the tumor microenvironment. However, the mechanism by which cancer cells mechanotransduce in the space environment, as well as the influence of this process on human health, have not been fully elucidated. Due to the growing interest in space biology, this article reviews cancer cell responses to the representative conditions altered in space: microgravity, decompression, and irradiation. Interestingly, cytokine and gene expression that assist in tumor survival, invasive phenotypic transformation, and cancer cell proliferation are upregulated when exposed to both simulated and actual space conditions. The necessity of further research on space mechanobiology such as simulating more complex in vivo experiments or finding other mechanical cues that may be encountered during spaceflight are emphasized.

Comparative N-glycoproteomic analysis of Tibetan and lowland chicken fertilized eggs: Implications on proteins biofunction and species evolution

The characterization and functionality of protein glycosylation among different related species are of common interest. Herein, non-standard quantification and N-glycosylation enrichment technology combined with ultra-high liquid chromatography-tandem mass spectrometry were used to establish detailed N-glycoproteomics of fertilized eggs, and quantitatively compared between Tibetan and lowland chicken. A total of 396N-glycosites from 143 glycoproteins were found. Specifically, compared with lowland chicken egg white, 32N-glycosites of 22 glycoproteins were up-regulated and 57N-glycosites of 25 glycoproteins were down-regulated in Tibetan chicken egg white. Also, 137N-glycosites in 72 glycoproteins showed much higher-degree glycosylation and 36N-glycosites in 15 glycoproteins displayed lower-degree glycosylation in Tibetan chicken egg yolk than those in lowland chicken egg yolk. Through bioinformatic analysis, these varied glycoproteins were highly associated with antifreeze activity, hypoxia adaptation, coagulation cascade, and binding/immunity activities, which may be related to plateau hypoxia and cold stress. PRACTICAL APPLICATIONS: These findings provide a new insight on the role of biological egg N-glycoproteins related to environmental adaptation and evolution, which may be further applied in improving egg processing and human health, by developing biomolecules for food and medical industry.

Effects of long-term high-altitude exposure on fibrinolytic system

OBJECTIVE

High altitude (HA), with the main feature of hypobaric hypoxia, is an independent risk factor for thrombosis. However, little is known on the alterations of fibrinolytic system in adaptation to HA. In this study, we investigated changes of fibrinolytic system parameters between individuals permanently living at HA and low altitude (LA) regions, and provided data for further studies on HA-induced thrombotic disease.

MATERIAL AND METHODS

A total of 226 eligible participants, including 103 LA participants, 100 healthy HA subjects and 23 high altitude polycythemia (HAPC) patients, were recruited in this study. Six fibrinolytic parameters, i.e. fibrinogen (Fbg), D-dimer (DDi), antithrombin III (AT-III), plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA) and plasminogen (PLG) were analyzed respectively. PAI-1 and tPA were performed by using bio-immuno-assays and an automated coagulation analyzer was used to conduct Fbg, DDi, AT-III and PLG tests.

RESULTS

Plasma levels of Fbg, DDi, PAI-1 and PLG were significantly higher in healthy HA group than in LA group (all p < 0.05), whereas tPA was significantly lower in healthy HA group. No significant difference in AT-III was observed between healthy HA and LA groups (p > 0.05). All these fibrinolytic parameters showed no significant distinctions between healthy HA subjects and HAPC patients (all p > 0.05). HGB showed no relationship with fibrinolytic parameters in HA cohort.

CONCLUSION

This study demonstrates that HA environment has a significant effect on fibrinolytic system and provides a foundation for further studies on HA hypobaric hypoxia-induced thrombotic disease.

Comparative Analysis of Skeleton Muscle Proteome Profile between Yak and Cattle Provides Insight into High-Altitude Adaptation

Background::

Mechanisms underlying yak adaptation to high-altitude environments have been investigated at the levels of morphology, anatomy, physiology, genome and transcriptome, but have not been explored at the proteome level.

Objective:

The protein profiles were compared between yak and cattle to explore molecular mechanisms underlying yak adaptation to high altitude conditions.

Methods:

In the present study, an antibody microarray chip was developed, which included 6,500 mouse monoclonal antibodies. Immunoprecipitation and mass spectrometry were performed on 12 selected antibodies which showed that the chip was highly specific. Using this chip, muscle tissue proteome was compared between yak and cattle, and 12 significantly Differentially Expressed Proteins (DEPs) between yak and cattle were identified. Their expression levels were validated using Western blot.

Results:

ompared with cattle, higher levels of Rieske Iron-Sulfur Protein (RISP), Cytochrome C oxidase subunit 4 isoform 1, mitochondrial (COX4I1), ATP synthase F1 subunit beta (ATP5F1B), Sarcoplasmic/ Endoplasmic Reticulum Calcium ATPase1 (SERCA1) and Adenosine Monophosphate Deaminase1 (AMPD1) in yak might improve oxygen utilization and energy metabolism. Pyruvate Dehydrogenase protein X component (PDHX) and Acetyltransferase component of pyruvate dehydrogenase complex (DLAT) showed higher expression levels and L-lactate dehydrogenase A chain (LDHA) showed lower expression level in yak, which might help yak reduce the accumulation of lactic acid. In addition, higher expression levels of Filamin C (FLNC) and low levels of AHNAK and Four and a half LIM domains 1 (FHL1) in yak might reduce the risks of pulmonary arteries vasoconstriction, remodeling and hypertension.

Conclusion:

Overall, the present study reported the differences in protein profile between yak and cattle, which might be helpful to further understand molecular mechanisms underlying yak adaptation to high altitude environments.

The multiple organs insult and compensation mechanism in mice exposed to hypobaric hypoxia

This study was first and systematically conducted to evaluate the hypoxia response of the brain, heart, lung, liver, and kidney of mice exposed to an animal hypobaric chamber. First, we examined the pathological damage of the above tissues by Hematoxylin & eosin (H&E) staining. Secondly, biochemical assays were used to detect oxidative stress indicators such as superoxide dismutase (SOD), malondialdehyde (MDA), reduced glutathione (GSH), and oxidized glutathione (GSSG). Finally, the hypoxia compensation mechanism of tissues was evaluated by expression levels of hypoxia-inducible factor 1 alpha (HIF-1α), erythropoietin (EPO), and vascular endothelial growth factor (VEGF). During the experiment, the mice lost weight gradually on the first 3 days, and then, the weight loss tended to remain stable, and feed consumption showed the inverse trend. H&E staining results showed that there were sparse and atrophic neurons and dissolved chromatin in the hypoxia group. And hyperemia occurred in the myocardium, lung, liver, and kidney. Meanwhile, hypoxia stimulated the enlargement of myocardial space, the infiltration of inflammatory cells in lung tissue, the swelling of epithelial cells in hepatic lobules and renal tubules, and the separation of basal cells. Moreover, hypoxia markedly inhibited the activity of SOD and GSH and exacerbated the levels of MDA and GSSG in the serum and five organs. In addition, hypoxia induced the expression of HIF-1α, EPO, and VEGF in five organs. These results suggest hypoxia leads to oxidative damage and compensation mechanism of the brain, heart, lung, liver, and kidney in varying degrees of mice.

Quantitative analysis of the global proteome in lung from mice with blast injury

AIM OF THE STUDY

The mechanism by which primary shock wave causes lung injury is unclear. The aim of this study is to find the changes of protein that can be helpful in understanding blast-induced lung injury.

MATERIAL AND METHODS

A quantitative analysis of their global proteome was conducted in lung from mice with blast injury using LC-MS/MS. Protein annotation, unsupervised hierarchical clustering, functional classification, functional enrichment and cluster, and protein-protein interaction analyses were performed. Furthermore, western blotting was used to validate the changed protein levels.

RESULTS

A total of 6498 proteins were identified, of which 5520 proteins were quantified. The fold-change cutoff was set at 1.2; 132 proteins were upregulated, and 104 proteins were downregulated. The bioinformatics analysis indicated that the differentially expressed proteins were involved in the cholesterol metabolism, asthma, nonalcoholic fatty liver disease. Remarkably, the processes related to the change of oxidative phosphorylation including the NADH dehydrogenase, Cytochrome C reductase, Cytochrome C oxidase and F-type ATPase were significantly upregulated, which were further verified by western blotting.

CONCLUSION

These results confirmed that the oxidative phosphorylation is critical to blast-induced lung injury. LC/MS-based profiling presented candidate target/pathways that could be explored for future therapeutic development.

Quantitative Proteomics Reveals the Effects of Resveratrol on High-Altitude Polycythemia Treatment

High-altitude polycythemia (HAPC) is a common plateau chronic disease in which red blood cells are compensatory hyperproliferative due to high altitude hypoxic environment. HAPC severely affects the physical and mental health of populations on the plateau. However, the pathogenesis and treatment of HAPC has been rarely investigated. Here, the hypoxia-induced HAPC model of rat is established, in which hemoglobin concentration significantly increases and platelets clearly decrease. The effect of resveratrol upon hypoxia enables HAPC remission and makes hemoglobin and platelet tend to a normal level. Furthermore, quantitative proteomics is applied to investigate the plasma proteome variation and the underlying molecular regulation during HAPC occurrence and treatment with resveratrol. Hypoxia promotes erythrocyte developing and differentiating and disrupts cytoskeleton organization. Notably, the resveratrol administration reverses the proteome change pattern due to hypoxia and contributes to plateau adaption. Quantitative verification of differentially expressed proteins confirms the roles of resveratrol in HAPC. Resveratrol is expected to be useful for HAPC treatment.

Mass Spectrometry-Based Plasma Proteomics: Considerations from Sample Collection to Achieving Translational Data

The proteomic analysis of human blood and blood-derived products (e.g., plasma) offers an attractive avenue to translate research progress from the laboratory into the clinic. However, due to its unique protein composition, performing proteomics assays with plasma is challenging. Plasma proteomics has regained interest due to recent technological advances, but challenges imposed by both complications inherent to studying human biology (e.g., interindividual variability) and analysis of biospecimens (e.g., sample variability), as well as technological limitations remain. As part of the Human Proteome Project (HPP), the Human Plasma Proteome Project (HPPP) brings together key aspects of the plasma proteomics pipeline. Here, we provide considerations and recommendations concerning study design, plasma collection, quality metrics, plasma processing workflows, mass spectrometry (MS) data acquisition, data processing, and bioinformatic analysis. With exciting opportunities in studying human health and disease though this plasma proteomics pipeline, a more informed analysis of human plasma will accelerate interest while enhancing possibilities for the incorporation of proteomics-scaled assays into clinical practice.