The human platelet transcriptome and proteome is altered and pro-thrombotic functional responses are increased during prolonged hypoxia exposure at high altitude.

Exposure to hypoxia, through ascension to high altitudes (HAs), air travel, or human disease, is associated with an increased incidence of thrombosis in some settings. Mechanisms underpinning this increased thrombosis risk remain incompletely understood, and the effects of more sustained hypoxia on the human platelet molecular signature and associated functional responses have never been examined. We examined the effects of prolonged (≥2 months continuously) hypobaric hypoxia on platelets isolated from subjects residing at HA (3,700 meters) and, for comparison, matched subjects residing under normoxia conditions at sea level (50 meters). Using complementary transcriptomic, proteomic, and functional methods, we identified that the human platelet transcriptome is markedly altered under prolonged exposure to hypobaric hypoxia at HA. Among the significantly, differentially expressed genes (mRNA and protein), were those having canonical roles in platelet activation and thrombosis, including membrane glycoproteins (e.g. GP4, GP6, GP9), integrin subunits (e.g. ITGA2B), and alpha-granule chemokines (e.g. SELP, PF4V1). Platelets from subjects residing at HA were hyperactive, as demonstrated by increased engagement and adhesion to fibrinogen, fewer alpha granules by transmission electron microscopy, increased circulating PF4 and ADP, and significantly enhanced clot retraction. In conclusion, we identify that prolonged hypobaric hypoxia exposure due to HA alters the platelet transcriptome and proteome, triggering increased functional activation responses that may contribute to thrombosis. Our findings may also have relevance across a range of human diseases where chronic hypoxia, platelet activation, and thrombosis are increased.

[Change of Plasma Interleukin-17 Level in Patients with Extranodal NK/T-Cell Lymphoma and Its Clinical Significance].

OBJECTIVE: To investigate the clinical significance of interleukin-17 (IL-17) level in patients with extranodal NK/T-cell lymphoma(ENKTL). METHODS: Eighty patients with nasal ENKTL who received radiotherapy, chemotherapy or radiotherapy combined with chemotherapy from January 2011 to January 2012 were enrolled in the study. Eighty healthy volunteers were selected as the controls (control group). About 5 ml of peripheral blood was collected from all patients and controls. IL-17 level was determined by ELISA. The age, sex, ECOG score, B symptoms, LDH level, lymph node involvment, Ann Arbor stage, IPI, KPI, peripheral blood lymphocyte and lymph node metastasis, number of lymphocytes and monocytes in peripheral blood were recorded. All patients were followed up for 3 year progression-free survival (PFS) and overall survival (OS). RESULTS: The average IL-17 level in patients with ENKTL was 6.48 pg/ml and the average concentration of IL-17 in control group was 0.56 pg/ml (P<0.01). The level of IL-17 in patients with B-symptoms and lymph node involvement was significantly higher than that in the control group. The differences in IL-17 level were not statistically significant among patients with different age, sex, ECOG, LDH, Ann Arbor stage, IPI, KPI, lymphocyte count and monocyte cell count. The sensitivity and specificity of IL-17 were 74.5% and 73.7% respectively, and the optimal threshold was 3.49 pg/ml and AUC was 0.799 (95% CI: 0.688-0.909) (P<0.01). The PFS and OS were longer in the patients with IL-17≤3.49 pg/ml and longer in the patients without lymph node involvement and Ann Arbor I. Multivariate analysis showed that independent predictors of PFS and OS in patients with ENKTL were plasma IL-17 levels and age (P<0.05). CONCLUSION: ENKTL patients with different clinical characteristics have different levels of IL-17, the different level of IL-17 has different effects on prognosis of patients with ENKTL.