NMR-based metabolomic analysis for the effects of creatine supplementation on mouse myoblast cell line C2C12 Wenqi Xu, Donghai Lin, and Caihua Huang The Key Laboratory for Chemical Biology of Fujian Province, MOE Key Laboratory of Spectrochemical Analysis Instrumentation, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China Acta Biochim Biophys Sin 2017, 49: 617–627; doi: 10.1093/abbs/gmx043 Creatine (Cr) supplementation has drawn much attention from researchers owing to its widespread efficacy in sports, and more recently, in therapeutic fields. However, the underlying molecular mechanisms remain elusive. Here, we performed nuclear magnetic resonance-based metabolomic analysis to address the metabolic profile of aqueous extracts from the mouse myoblast cell line C2C12 exposed to 2 mM Cr for 24 h (the Cr-treated group). Results showed that Cr supplementation facilitated the proliferation of C2C12 myoblasts. Both pattern recognition and hierarchical cluster analyses demonstrated that the metabolic profiles of the Cr-treated and control groups were distinctly different. We identified 13 characteristic metabolites significantly responsible for the discrimination of metabolic profiles between the two groups, through orthogonal projection to latent structures discriminant analysis and independent samples t-test. We further verified the discrimination performances of these metabolites by conducting univariate receiver operating characteristic curve analysis. Compared with the control group, the Cr-treated group exhibited increased levels of Cr, phosphocreatine (PCr), glutathione (GSH), and glucose, but decreased levels of leucine, valine, isoleucine, phenylalanine, methionine, choline, O-phosphocholine, sn-glycero-3-phosphocholine, and glycerol. Our results demonstrated that Cr supplementation upregulated PCr and glucose, promoted trichloroacetic acid cycle anaplerotic flux and GSH-mediated antioxidant capacity, and stabilized lipid membranes through suppressing glycerophospholipid metabolism. Our work provides new clues to the molecular mechanisms underlying the pleiotropic effects of Cr in muscle cells. Metabolic profiles between the control and Cr-treated groups 阅读原文: http://www.abbs.org.cn/arts.asp?id=4177 获取全文: abbs@sibs.ac.cn 相关论文: 1 The potential therapeutic effects of creatine supplementation on body composition and muscle function in cancer 2 Creatine and creatinine metabolism 3 Long-term creatine intake is beneficial to muscle performance during resistance training 4 Impaired muscle uptake of creatine in spinal and bulbar muscular atrophy 5 Beyond muscles: The untapped potential of creatine 6 Muscle creatine loading in men 7 Isolated heart muscle of creatine kinase deficient mice is unable to maintain high-performance states and present altered myocardial calcium homeostasis 8 Myocyte-specific expression of the sarcomeric mitochondrial creatine kinase gene in heart and skeletal muscle
葡萄糖和氨基酸对纯镁腐蚀的影响 曾荣昌 山东科技大学 在人体生理环境中，可降解镁的腐蚀不仅涉及无机物（如Cl − 、 HPO 4 2− 、 HCO 3 − 和 Ca 2+ )，也与有机物（如葡萄糖、蛋白质或氨基酸）有关。 目前，尽管有许多研究涉及合金元素、第二相、及其它成分和Tris-HCl，我们还缺乏对生物医用镁腐蚀的全面理解。 大多数情况下，医用镁合金体外腐蚀试验是在0.9%NaCl、磷酸缓冲溶液（PBS）、Hank's 溶液，在这些溶液中仅有无机离子存在，诸如： Cl − 、 HPO 4 2− 、 HCO 3 − 和 H 2 PO 4 − 。镁及其合金与溶液的交互作用导致镁的离子化，镁离子与上述阴离子反应形成沉积物。 我们注意到，在人体体液中除了无机离子，还有大量有机物，它们对镁的腐蚀也有重要影响。然而，相关研究很少报道。我们前期研究发现，在0.9%NaCl溶液中，随 葡萄糖 浓度(25 g/L)的增加，纯镁的腐蚀速率增加。这是因为葡萄糖转变为葡萄糖酸，导致溶液酸化。相反地，在hank's溶液中，随葡萄糖浓度的增加，腐蚀速率降低。这是因为葡萄糖促进了镁表面Ca-P产物的形成。 蛋白质作为生物大分子，在镁的腐蚀过程中起着重要作用。蛋白质分子与金属表面通过静电吸附、共价键和离子键发生交互作用。这一过程受到许多因素的影响，例如，溶液成分、蛋白质浓度以及材料的物理性质。吸附和络合是蛋白质影响镁降解的主要机制。 涉及蛋白质对镁的腐蚀机制存在不同的争论。一种观点认为，由于蛋白质的吸附以及在镁表面形成蛋白质的吸附层，从而降低镁的腐蚀速率。而且，蛋白质浓度越高，对腐蚀的阻滞效果也更为明显。另一种观点认为，蛋白质加速镁的腐蚀速率。这是由于蛋白质的羧基失去氢离子，而导致溶液pH值的变化。 蛋白质是由氨基酸组成的。常见的 氨基酸 有20种。因此，有必要了解氨基酸对镁腐蚀的影响。虽然有报道，氨基酸加速纯镁的溶解。但仍然有必要进一步了解氨基酸对镁腐蚀的影响。特别是，葡萄糖和氨基酸的耦合对镁腐蚀的影响还有待阐释。 本研究表明，葡萄糖（2.0 g/L）和氨基酸均阻滞纯镁在0.9%NaCl中的腐蚀。但葡萄糖和氨基酸的耦合加速了纯镁的腐蚀速率。这是因为在氨基酸和葡萄糖之间形成了-C=N- 键(Schiff bases) , 它限制了形成Mg(OH) 2 沉淀。 此项工作“In Vitro Degradation of Pure Magnesium―The Effects of Glucose and/or Amino Acid”发表在期刊《Materials》（2017, 10, 725）,并 得到了国家自然科学基金项目(51571134)和山东科技大学科研创新团队经费(2014TDJH104)的支持 。 Fig. 1. X-ray photoelectron spectroscopy (XPS) analysis of a pure Mg surface after immersion in solution #2 through #4 for various periods showing the (a) entire range of the binding energy survey and (b) C 1s spectra for sample surfaces after immersion in solution #2 to #4 for 1 h and 12 h; C 1s spectra of samples immersed in (c) solution #2, (d) solution #3 and (e) solution #4 for 12 h; Mg 1s spectra for samples after immersion (f–h) in solution #2 to #4 for 12 h. Fig. 2 Schematic illustration of the corrosion process of pure Mg during immersion in solution #4: (a) I stage; (b) II stage; and (c) III stage 相关链接： materials-10-00725.pdf 博文：镁合金腐蚀研究进展（八）—葡萄糖对镁体外腐蚀/降解行为的影响
葡萄糖对镁体外腐蚀/降解行为的影响 曾荣昌 山东科技大学 【按】Nature 出版集团旗下的《 Scientific Reports 》（科学报告）刊发了我课题组在医用镁腐蚀机理方面的科学发现。论文题目为 “ Invitro degradation of pure Mg in response to glucose ” （ 5:13026, DOI: 10.1038/srep13026 ）。 随着人口老龄化日趋严重，人们越来越关注血糖水平、糖尿病的患病率以及血糖调节障碍等问题。在全球范围内，预估糖尿病患者的数量将从 2000 年的 1.71 亿增至 2030 的 3.66 亿。全球老龄化对生物材料的需求日益增加，这使得高血糖和糖尿病患者在植入生物材料问题上面临着巨大的挑战。 镁及镁合金具有独特的生物相容性、生物降解性和力学相容性，作为新一代生物医用材料具有广泛的应用前景。然而，镁非常活泼，耐蚀性能较差。镁的腐蚀问题则是制约其广泛应用的瓶颈因素。虽然有关镁合金在模拟生理溶液中的腐蚀行为已有大量的研究，并取得了明显的进展。因人体内环境因素的复杂性，医用镁及合金腐蚀机理仍然没有得到很好的阐释。 影响医用镁及合金腐蚀的因素包括 阳离子（ Mg 2+ 、 Ca 2+ 等）、 阴离子（ Cl - 、 HCO 3 - 、 HPO 4 2 和 - H 2 PO 4 - 等） 以及有机化合物（氨基酸，蛋白质和葡萄糖等）。然而，有关葡萄糖对镁合金腐蚀影响的研究很少报道。众所周知，高血糖可能导致糖尿病的发生，高血糖或糖尿病人植入镁合金后可能面临较大风险。另外，镁还是一种重要的细胞间离子，在血糖和胰岛素的调解中扮演重要角色。所以，研究葡萄糖对镁合金腐蚀行为影响具有重要意义。 论文基于材料与化学交互作用，以己六醇作为对照物，通过电子探针、光电子能谱等现代表面分析和电化学测试技术，全面地分析了葡萄糖对纯镁腐蚀行为的影响，加深了人们对镁腐蚀过程的认识。此项研究阐明了镁在不同浓度葡萄糖模拟体液中的腐蚀机理，为医用镁合金研究开启了一扇新窗户。 上述研究工作得到了国家自然科学基金项目和山东科技大学科研创新团队经费的支持。 Abstract : Magnesium and its alloys are promising biodegradable biomaterials but are still challenging to be used in person with high levels of blood glucose or diabetes. To date, the influence of glucose on magnesium degradation has not yet been elucidated, this issue requires more attention. Herein, we present pure Mg exhibiting different corrosion responses to saline and Hank’s solutions with different glucose contents, and the degradation mechanism of pure Mg in the saline solution with glucose in comparison with mannitol as a control. On one hand, the corrosion rate of pure Mg increases with the glucose concentration in saline solutions. Glucose rapidly transforms into gluconic acid, which attacks the oxides of the metal and decreases the pH of the solution; it also promotes the absorption of chloride ions on the Mg surface and consequently accelerates corrosion. On the other hand, better corrosion resistance is obtained with increasing glucose content in Hank’s solution due to the fact that glucose coordinates Ca2+ ions in Hank’s solution and thus improves the formation of Ca-P compounds on the pure Mg surface. This finding will open up new avenues for research on the biodegradation of bio-Mg materials in general, which could yield many new and interesting results. In vitro degradation of pure Mg in response to glucose.pdf
标签: glucose
