glycogen granules

  • 文章类型: Journal Article
    自噬最初被认为是一种批量降解过程,它随机隔离和降解溶酶体(酵母中的液泡)中的细胞质物质。近年来,已经发现了各种类型的选择性自噬。糖食,糖原颗粒的选择性自噬,是其中之一。虽然糖原的自噬是导致庞贝氏症的重要因素,其特征是糖原的溶酶体积累,它的选择性仍然是一个争论的问题。这里,我们开发了Komagataellaphafii酵母作为氮饥饿条件下糖原自噬的简单模型,以解决其选择性问题。为此,我们把糖原合成的自糖基化引发剂,与糖原共价结合的Glg1,进入Glg1-GFP自噬报告分子。我们的结果表明,Glg1-GFP的液泡递送及其对游离GFP的加工严格依赖于自噬机制和液泡蛋白水解。值得注意的是,该过程与许多选择性自噬途径常见的支架蛋白Atg11无关。重要的是,未突变的Glg1-GFP(其合成并标记糖原)和突变的Glg1Y212F-GFP(其不合成糖原并且被非选择性自噬降解为胞质Pgk1-GFP)同样良好地递送至液泡,并且具有相似水平的GFP释放.因此,我们得出结论,在氮饥饿条件下,糖原自噬是K.phafii酵母中的非选择性过程。
    Autophagy was initially recognized as a bulk degradation process that randomly sequesters and degrades cytoplasmic material in lysosomes (vacuoles in yeast). In recent years, various types of selective autophagy have been discovered. Glycophagy, the selective autophagy of glycogen granules, is one of them. While autophagy of glycogen is an important contributor to Pompe disease, which is characterized by the lysosomal accumulation of glycogen, its selectivity is still a matter of debate. Here, we developed the Komagataella phaffii yeast as a simple model of glycogen autophagy under nitrogen starvation conditions to address the question of its selectivity. For this, we turned the self-glucosylating initiator of glycogen synthesis, Glg1, which is covalently bound to glycogen, into the Glg1-GFP autophagic reporter. Our results revealed that vacuolar delivery of Glg1-GFP and its processing to free GFP were strictly dependent on autophagic machinery and vacuolar proteolysis. Notably, this process was independent of Atg11, the scaffold protein common for many selective autophagy pathways. Importantly, the non-mutated Glg1-GFP (which synthesizes and marks glycogen) and mutated Glg1Y212F-GFP (which does not synthesize glycogen and is degraded by non-selective autophagy as cytosolic Pgk1-GFP) were equally well delivered to the vacuole and had similar levels of released GFP. Therefore, we concluded that glycogen autophagy is a non-selective process in K. phaffii yeast under nitrogen starvation conditions.
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  • 文章类型: Journal Article
    糖尿病患者对血栓栓塞事件的易感性增加,在大多数情况下,起源于左心耳(LAA)的血栓。LAA的重塑,容易形成血栓,以前曾在糖尿病合并房颤患者中描述过,但糖尿病患者在没有房颤的情况下是否也会发生LAA重塑尚不清楚.为了调查糖尿病的贡献,与心房颤动相反,重建LAA,我们从人类到动物模型。
    我们通过超声心动图研究了科恩糖尿病敏感大鼠(CD/y)在糖尿病演变过程中的多个时间点的心脏结构和功能,该大鼠提供了4个月的糖尿病饮食;CD/y提供了常规饮食和科恩糖尿病抗性(CDr/y),不会发展为糖尿病,作为控制。在整个研究期间,所有动物都处于窦性心律。
    与对照相比,CDs/y在糖尿病的演变过程中产生了更大的心脏质量,左心房直径较大,较宽的左心耳孔口,LAA深度增加,舒张末期和收缩末期直径较大,和较低的E/A比-都表明左心耳和左心房(LA)的重塑,以及左心室舒张功能障碍的发展。为了调查所涉及的病理生理学,我们在研究结束时研究了心脏的组织学。我们在糖尿病CD/Y中发现,但在其他任何群体中都没有,心耳中有丰富的糖原颗粒,心房和心室,这可能具有重要意义,因为糖原颗粒以前与糖尿病心脏的细胞和器官功能障碍有关。
    我们得出结论,我们的啮齿动物糖尿病模型,这是窦性心律,复制了先前在患有房颤的糖尿病患者心脏中观察到的结构和功能改变。在我们的模型中,LAA和LA的重塑与心房颤动无关,并且与糖原颗粒的积累有关。我们认为糖原颗粒的心肌积累与糖尿病的发展有关,可能在LAA和LA的重塑中起病理生理作用。容易导致心房颤动,糖尿病心脏的血栓栓塞事件和左心室舒张功能障碍。
    Diabetic patients have an increased predisposition to thromboembolic events, in most cases originating from thrombi in the left atrial appendage (LAA). Remodeling of the LAA, which predisposes to thrombi formation, has been previously described in diabetic patients with atrial fibrillation, but whether remodeling of the LAA occurs in diabetics also in the absence of atrial fibrillation is unknown. To investigate the contribution of diabetes, as opposed to atrial fibrillation, to remodeling of the LAA, we went from humans to the animal model.
    We studied by echocardiography the structure and function of the heart over multiple time points during the evolution of diabetes in the Cohen diabetic sensitive rat (CDs/y) provided diabetogenic diet over a period of 4 months; CDs/y provided regular diet and the Cohen diabetic resistant (CDr/y), which do not develop diabetes, served as controls. All animals were in sinus rhythm throughout the study period.
    Compared to controls, CDs/y developed during the evolution of diabetes a greater heart mass, larger left atrial diameter, wider LAA orifice, increased LAA depth, greater end-diastolic and end-systolic diameter, and lower E/A ratio-all indicative of remodeling of the LAA and left atrium (LA), as well as the development of left ventricular diastolic dysfunction. To investigate the pathophysiology involved, we studied the histology of the hearts at the end of the study. We found in diabetic CDs/y, but not in any of the other groups, abundance of glycogen granules in the atrial appendages , atria  and ventricles, which may be of significance as glycogen granules have previously been associated with cell and organ dysfunction in the diabetic heart.
    We conclude that our rodent model of diabetes, which was in sinus rhythm, reproduced structural and functional alterations previously observed in hearts of human diabetics with atrial fibrillation. Remodeling of the LAA and of the LA in our model was unrelated to atrial fibrillation and associated with accumulation of glycogen granules. We suggest that myocardial accumulation of glycogen granules is related to the development of diabetes and may play a pathophysiological role in remodeling of the LAA and LA, which predisposes to atrial fibrillation, thromboembolic events and left ventricular diastolic dysfunction in the diabetic heart.
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  • 文章类型: Journal Article
    背景:脓毒症,对感染的全身性炎症反应,是世界上主要的死亡原因.早期发现和识别总体代谢和功能的促炎变化可以帮助适当干预和控制炎症状态。会改善预后.
    目的:在资源有限的环境中,生物标志物不易获得,需要这种简单的技术,可以帮助早期识别感染和炎症。
    方法:本研究通过制备外周涂片和高碘酸希夫(PAS)染色来发现炎症过程中糖原积累和形态变化的变化。
    结果:这项研究表明,中性粒细胞在整个细胞质中积聚糖原颗粒,细胞质中存在空泡,从而增加中性粒细胞的大小和染色质的分散。
    结论:PAS染色可作为脓毒症的诊断方法。
    BACKGROUND: Sepsis, a systemic inflammatory reaction to infection, is the leading cause of death in the world. The early detection and identification of pro-inflammatory changes in overall metabolism and functioning can help in the proper intervention and control of the inflammatory state, and it will improve the prognosis.
    OBJECTIVE: In a resource-limited setting where the biomarkers are not easily accessible, this simple technique is required that can help in the early identification of infection and inflammation.
    METHODS: The present study was conducted to find the change in glycogen accumulation and morphological changes during inflammation by preparing a peripheral smear and periodic acid-Schiff (PAS) staining.
    RESULTS: This study shows that the neutrophil accumulates glycogen granules throughout the cytoplasm with the presence of vacuoles in the cytoplasm, thus increasing the neutrophil size and chromatin dispersion.
    CONCLUSIONS: PAS staining can be used as a diagnostic method to detect sepsis.
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