Background

Organisms can be primed by metabolic exposures to continue expressing response genes even once the metabolite is no longer available, and can affect the speed and magnitude of responsive gene expression during subsequent exposures. This “metabolic transcriptional memory” can have a profound impact on the survivability of organisms in fluctuating environments.

Scope of review

Here I present several examples of metabolic transcriptional memory in the microbial world and discuss what is known so far regarding the underlying mechanisms, which mainly focus on chromatin modifications, protein inheritance, and broad changes in metabolic network. From these lessons learned in microbes, some insights into the yet understudied human metabolic memory can be gained. I thus discuss the implications of metabolic memory in disease progression in humans – i.e., the memory of high blood sugar exposure and the resulting effects on diabetic complications.

Major conclusions

Carbon source shifts from glucose to other less preferred sugars such as lactose, galactose, and maltose for energy metabolism as well as starvation of a signal transduction precursor sugar inositol are well-studied examples of metabolic transcriptional memory in Escherichia coli and Saccharomyces cerevisiae. Although the specific factors guiding metabolic transcriptional memory are not necessarily conserved from microbes to humans, the same basic mechanisms are in play, as is observed in hyperglycemic memory. Exploration of new metabolic transcriptional memory systems as well as further detailed mechanistic analyses of known memory contexts in microbes is therefore central to understanding metabolic memory in humans, and may be of relevance for the successful treatment of the ever-growing epidemic of diabetes.

中文翻译：

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代谢转录记忆。

背景

即使代谢产物不再可用，也可以通过代谢暴露来引发生物体继续表达反应基因，并且可以影响后续暴露过程中反应基因表达的速度和大小。这种“代谢转录记忆”可能会对生物在变化的环境中的生存能力产生深远的影响。

审查范围

在这里，我将介绍微生物界中新陈代谢转录记忆的几个例子，并讨论迄今为止已知的有关潜在机制的知识，这些机制主要集中于染色质修饰，蛋白质遗传和代谢网络的广泛变化。从微生物学到的这些教训中，可以获得对尚未被研究的人类代谢记忆的一些见解。因此，我讨论了代谢记忆在人类疾病进展中的意义，即高血糖暴露的记忆及其对糖尿病并发症的影响。

主要结论

碳源从葡萄糖转移到其他次优的糖类（例如乳糖，半乳糖和麦芽糖）中进行能量代谢以及信号转导前体糖肌醇的饥饿化是大肠杆菌和酿酒酵母中代谢转录记忆研究的充分实例。尽管指导代谢转录记忆的特定因素不一定从微生物向人类保守，但正如在高血糖记忆中观察到的那样，相同的基本机制也在起作用。因此，对新的代谢转录记忆系统的探索以及对微生物中已知记忆环境的进一步详细的机械分析，对于理解人类的代谢记忆至关重要，并且可能与成功治疗不断增长的糖尿病流行有关。