Additional file 1 of Differential methylation in EGLN1 associates with blood oxygen saturation and plasma protein levels in high-altitude pulmonary edema

Additional file 1. Fig. S1 Levels of SpO2 % in HAPE-p, HAPE-f and HLs. Fig. S2 Dot plot of CpG methylation in EGLN1 in the three study groups, i.e., HAPE-p, HLs and HAPE-f. It revealed 97 CpG sites in EGLN1 CpG island 179. Fig. S3 Dot plot of CpG methylation in HIF1AN in the three study groups, i.e., HAPE-f, HAPE-p and HLs. It revealed 46 CpG sites in HIF1AN CpG island 47. Table S1 Methylation distribution of CpG sites of EGLN1 and HIF1AN in each subject of the three study groups i.e., HAPE-f, HAPE-p and HLs. Table S2 Real-time PCR conditions for EGLN1 and HIF1AN. Table S3 Sodium bisulfite-conversion-based methylation PCR Primers and conditions for EGLN1 and HIF1AN

Clinical correlations in the three groups i.e. HAPE-p, HAPE-f and HLs.

<p>An inverse correlation was obtained between the clinical parameters viz MAP and SaO₂ in the three groups; MAP, mmHg; SaO₂, %.</p

Interactions among Vascular-Tone Modulators Contribute to High Altitude Pulmonary Edema and Augmented Vasoreactivity in Highlanders

<div><h3>Background</h3><p>The interactions among various biomarkers remained unexplored under the stressful environment of high-altitude. Present study evaluated interactions among biomarkers to study susceptibility for high altitude pulmonary edema (HAPE) in HAPE-patients (HAPE-p) and adaptation in highland natives (HLs); both in comparison to HAPE-free sojourners (HAPE-f).</p> <h3>Methodology/Principal Findings</h3><p>All the subjects were recruited at 3500 m. We measured clinical parameters, biochemical levels in plasma and gene expression using RNA from blood; analyzed various correlations between and among the clinical parameters, especially arterial oxygen saturation (SaO₂) and mean arterial pressure (MAP) and biochemical parameters like, asymmetric dimethylarginine (ADMA), serotonin (5-HT), 8-iso-prostaglandin F2α (8-isoPGF2α), endothelin-1 (ET-1), plasma renin activity (PRA), plasma aldosterone concentration (PAC), superoxide dismutase (SOD) and nitric oxide (NO) in HAPE-p, HAPE-f and HLs. ADMA, 5-HT, 8-isoPGF2α, ET-1 levels, and PAC were significantly higher (p<0.0001, each), whereas SOD activity and NO level were significantly lower in HAPE-p than HAPE-f (p≤0.001). Furthermore, ADMA, 5-HT, 8-isoPGF2α, NO levels and PAC were significantly higher (p<0.0001), whereas ET-1 level significantly (p<0.0001) and SOD activity non-significantly (p>0.05) lower in HLs than HAPE-f. The expression of respective genes differed in the three groups. In the correlations, SaO₂ inversely correlated with ADMA, 5-HT and 8-isoPGF2α and positively with SOD in HAPE-p (p≤0.009). MAP correlated positively with 5-HT and 8-isoPGF2α in HAPE-p and HLs (p≤0.004). A strong positive correlation was observed between ADMA and 5-HT, 5-HT and 8-isoPGF2α (p≤0.001), whereas inverse correlation of SOD with ET-1 in HAPE-p and HLs (p≤0.004), with 5-HT and 8-isoPGF2α in HAPE-p (p = 0.01) and with 5-HT in HLs (p = 0.05).</p> <h3>Conclusions/Significance</h3><p>The interactions among these markers confer enhanced vascular activity in HLs and HAPE in sojourners.</p> </div

Clinical characteristics of the HAPE-p, HAPE-f and HLs.

<p>Data are presented as mean ± standard deviation and are compared by Student's <i>t</i>-test. n, number of subjects; SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure; RR, respiratory rate; PR, pulse rate; SaO₂, arterial oxygen saturation; PASP, pulmonary artery systolic pressure.</p

Schematic presentation of the studied biomarkers in a physiological function under hypobaric hypoxia.

<p>Interactions of several of these biomarkers that translate into the incidence of HAPE are also interpretable through the renin–angiotensin–aldosterone system, Kinin–kallikrein system, and the pathways of ET-1, 5-HT, NO signaling and oxidative-stress. ADMA, asymmetric dimethylarginine; ATII, angiotensin II; AT-1R, angiotensin-II type I receptor; AT-2R, angiotensin-II type II receptor; AngI, angiotensin I; AngII, angiotensin II; ACE, angiotensin-I converting enzyme; AGT, angiotensinogen; 8-isoPGF2α, 8-iso-prostaglandinF2α; ROS, reactive oxygen species; SOD, superoxide dismutase; O2˙-, superoxide anion; ONOO⁻, peroxynitrite; 5-HT, serotonin; ET-1, endothelin-1; ET-_A and ET-_B, endothelin receptors A and B; NO, nitric oxide; NOS3, endothelial nitric oxide synthase; VSMC, vascular smooth muscle cell; H₂O₂, hydrogen peroxide; H₂O, water; EFA, essential fatty acids.</p

Baseline characteristics of the HAPE-p, HAPE-f and HLs.

<p>Data are presented as mean ± standard deviation and are compared by Student's <i>t</i>-test. n, number of subjects; BMI, body mass index.</p

Supplemental Tables S1-S4.docx

Hypobaric hypoxia modulated structural characteristics of circulating cell free DNA in high altitude pulmonary edema</p

Supplemental Figures S1-S3

Hypobaric hypoxia modulated structural characteristics of circulating cell free DNA in high altitude pulmonary edema</p