HIF-1与肌肉糖酵解酶

HIF-1低氧诱导哺乳动物细胞产生适应的关键因子。HIF-1是一种DNA结合蛋白，可以诱导包括糖酵解代谢酶在内的多种基因表达的增加，产生对低氧环境的适应。糖酵解代谢酶的活性在低氧诱导下增加，细胞无氧代谢能力加强。低氧训练的生物学基础在于低氧诱导的细胞适应，因此我们预测大强度的低氧训练(低住高练)可以提高机体的无氧代谢能力。     

HiLo(高住低训)——耐力训练的新方法

自 1990年美国学者Dr.Leving提出HiLo (高原居住、低处训练 )的新方法 ,越来越受到人们重视 ,实践证明这是比传统高原训练更行之有效的方法之一 ,本文以比较的角度介绍此方法 ,旨在引起我国体育工作者的重视 ,加强这方面的认识。     

基于微阵列技术的缺氧/复氧诱导下血管内皮细胞转录组分析

目的:应用全转录组芯片研究缺氧/复氧诱导下人脐静脉内皮细胞(HUVEC)的转录组轮廓。创新点:血管内皮细胞(VEC)缺氧/复氧损伤被视定为许多生理和病理过程中导致器官功能障碍的重要驱动因素。然而,其详细病理生理机制和基因表达谱信息尚未阐明。本研究首次应用全转录组芯片技术研究VEC缺氧/复氧诱导下的转录组轮廓。方法:采用缺氧孵育3h后复氧1h的HUVEC为缺氧/复氧组,同时常氧孵育的HUVEC为常氧对照组。应用含58 339条探针的全转录组芯片检测每组三个样本。对差异表达基因进行生信分析和功能验证。结论:本研究发现372个有意义的差异表达基因探针。相关基因涵盖多种途径和功能,例如氧自由基的产生、钙超载、炎症、糖脂代谢、内皮细胞增殖、分化、细胞骨架及通透性调节、细胞裂解、凋亡和血管生成。另外,实验进一步表明,差异表达基因pleckstrin同源样域家族A成员1(PHLDA1)的m RNA和蛋白质表达结果与微阵列结果一致。STRING分析发现,PHLDA1可能与差异表达基因SLC38A3、SLC5A5、Lnc-SLC36A4-1和Lnc-PLEKHJ1-1具有物理性和/或功能性相互作用,这有望揭示VEC在缺氧/复氧环境下长链非编码RNA(lnc RNA)的相关机制。     

Effect of a Prolonged Altitude Expedition on Glucose Tolerance and Abdominal Fatness

In the present study, we investigated the effect of a long-term mountain expedition on glucose tolerance and insulin action. Twelve registered mountaineers ages 31 years (SD = 1.1) participated in a 25-day expedition at a 2,200-3,800-m altitude with an average duration of 8 hr per day. Arterial oxygen saturation (SaO2) was substantially reduced during hiking. Glucose tolerance and insulin responses were measured prior to and twice during the expedition period. Maximal oxygen consumption increased from 43.0 ± 2.7 to 49.1 ± 2.2 mL/kg/min. Percentage of body fat decreased from 19.4 ± 6.8% to 16.9 ± 5.9%. The area under the curves for insulin and glucose during the oral glucose tolerance test were also reduced in Days 3 and 25. The present study demonstrated that altitude hiking activity is an effective lifestyle intervention to improve insulin action.     

Protective paracrine effect of mesenchymal stem cells on cardiomyocytes

Objective  The aim of this study was to test the protective effect of mesenchymal stem cells (MSCs) on cardiomyocytes in vitro and to investigate the anti-apoptotic signaling pathway. Methods  MSCs from Sprague-Dawley (SD) rats were separated and cultured. MSC medium was collected from MSCs cultured in serum-free Dulbecco’s modified eagle medium (DMEM) under hypoxia. Cultured cardiomyocytes from neonatal SD rats were exposed to hypoxia/reoxygenation (H/R) and treated with MSC medium. The apoptotic cardiomyocytes were stained with Annexin-V-fluorescein isothiocyanate (FITC), Hoechst 33342 and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL). The mitochondrial transmembrane potential of cardiomyocytes was assessed using a fluorescence microscope. The expression of Bcl-2, Bax, cytochrome C, apoptosis-induced factor (AIF), and caspase-3 was tested by Western blot analysis. Results  Our data demonstrated that MSC medium reduced H/R-induced cardiomyocyte apoptosis, increased the Bcl-2/Bax ratio, and reduced the release of cytochrome C and AIF from mitochondria into the cytosol. Conclusion  MSCs protected the cardiomyocytes from H/R-induced apoptosis through a mitochondrial pathway in a paracrine manner. Project supported by the National Natural Science Foundation of China (No. 30670868) and the Natural Science Foundation of Zhejiang Province, China (No. R206007)     

Photochemical colour change for traditional watercolour pigments in low oxygen levels

Abstract

An investigation for light exposure on pigments in low-oxygen environments (in the range 0–5% oxygen) was conducted using a purpose-built automated microfadometer for a large sample set including multiple samples of traditional watercolour pigments from nineteenth-century and twentieth-century sources, selected for concerns over their stability in anoxia. The pigments were prepared for usage in watercolour painting: ground and mixed in gum Arabic and applied to historically accurate gelatine glue-sized cotton and linen-based papers. Anoxia benefited many colorants and no colorant fared worse in anoxia than in air, with the exception of Prussian blue and Prussian green (which contains Prussian blue). A Prussian blue sampled from the studio materials of J.M.W. Turner (1775 ? 1851) was microfaded in different environments (normal air (20.9% oxygen) 0, 1, 2, 3.5, or 5% oxygen in nitrogen) and the subsequent dark behaviour was measured. The behaviour of the sample (in normal air, anoxia, and 5% oxygen in nitrogen) proved to be consistent with the 55 separately sourced Prussian blue samples. When exposed to light in 5% oxygen in nitrogen, Prussian blue demonstrated the same light stability as in air (at approximately 21°C and 1 atmosphere). Storage in 5% oxygen is proposed for ‘anoxic’ display of paper-based artworks that might contain Prussian blue, to protect this material while reducing light-induced damage to other components of a watercolour, including organic colorants and the paper support.     

Hepcidin：低氧训练对机体铁代谢影响的关键调节因子

机体稳定的铁状态是维持生命活动的基本要素.诸多因素影响机体铁代谢,包括：饮食、低氧、运动等,其中低氧对机体铁代谢的影响备受关注.在机体铁代谢这个严密的调节系统中,关键调节因子Hepcidin在低氧影响机体铁稳态中起到了桥梁作用.低氧状态下Hepcidin调节铁代谢的分子机制成为近年来研究的热点.研究发现,低氧诱导因子（hypoxia inducible factor,HIF）/低氧反应元件（hypoxia response element,HRE）系统发挥着重要的作用,同时发现肥胖引起的局部低氧会导致铁代谢的紊乱,与低氧引发的炎症导致Hepcidin水平异常有关.另外发现低氧训练引起机体内氧浓度的变化会通过Hepcidin引起机体铁代谢适应性交化.     

Ventilatory acclimatisation is beneficial for high-intensity exercise at altitude in elite cyclists

Aim: The aim of this study was to examine the relationship between ventilatory adaptation and performance during altitude training at 2700?m. Methods: Seven elite cyclists (age: 21.2?±?1.1?yr, body mass: 69.9?±?5.6?kg, height 176.3?±?4.9?cm) participated in this study. A hypoxic ventilatory response (HVR) test and a submaximal exercise test were performed at sea level prior to the training camp and again after 15 d at altitude (ALT15). Ventilation (V_E), end-tidal carbon-dioxide partial pressure (P_ETCO₂) and oxyhaemoglobin saturation via pulse oximetry (SpO₂) were measured at rest and during submaximal cycling at 250?W. A hill climb (HC) performance test was conducted at sea level and after 14 d at altitude (ALT14) using a road of similar length (5.5–6?km) and gradient (4.8–5.3%). Power output was measured using SRM cranks. Average HC power at ALT14 was normalised to sea level power (HC%). Multiple regression was used to identify significant predictors of performance at altitude. Results: At ALT15, there was a significant increase in resting V_E (10.3?±?1.9 vs. 12.2?±?2.4?L·min^?1) and HVR (0.34?±?0.24 vs. 0.71?±?0.49?L·min^?1·%^?1), while P_ETCO₂ (38.4?±?2.3 vs. 32.1?±?3.3?mmHg) and SpO₂ (97.9?±?0.7 vs. 94.0?±?1.7%) were reduced (P?V_E at altitude as significant predictors of HC% (adjusted r²?=?0.913; P?=?0.003). Conclusions: Ventilatory acclimatisation occurred during a 2 wk altitude training camp in elite cyclists and a higher HVR was associated with better performance at altitude, relative to sea level. These results suggest that ventilatory acclimatisation is beneficial for cycling performance at altitude.