Nanoscale Organisation of Ryanodine Receptors and Junctophilin-2 in the Failing Human Heart.
Nanoscale Organisation of Ryanodine Receptors and Junctophilin-2 in the Failing Human Heart.
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DOI：
10.3389/fphys.2021.724372
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发表时间：
2021
影响因子：
4
通讯作者：
Crossman DJ
中科院分区：
文献类型：
--
作者：
Hou Y;Bai J;Shen X;de Langen O;Li A;Lal S;Dos Remedios CG;Baddeley D;Ruygrok PN;Soeller C;Crossman DJ
Ryanodine受体（RyR）和junctophilin（JPH）的破坏组织被认为是衰竭心脏中横小管（t-小管）重塑的基础。在这里，我们评估了这两种关键蛋白质在人类心脏衰竭中的纳米级组织。最近，一个先进的特徴的t-小管重塑确定大型扁平的t-小管称为t-片，这是几个微米宽。以前，我们报道在衰竭的心脏中，扩张的t-小管宽达1 μm，胶原蛋白增加，我们假设t-片层也与胶原蛋白沉积有关。直接随机光学重建显微镜（dSTORM），共聚焦显微镜，和蛋白质印迹法被用来评估兴奋收缩结构的细胞分布在心肌细胞中的特发性扩张型心肌病（IDCM）患者相比，从非衰竭（NF）的人心脏的心肌细胞。RyR和JPH的dSTORM成像发现IDCM和NF肌细胞之间的共定位没有差异，但与口部区域相比，t-小管和肌膜的共定位更高。蛋白质印迹显示JPH表达没有变化，但确定了RyR的约50%下调（p = 0.02）。dSTORM成像显示了较小t-管状RyR簇（~24%）的趋势，并降低了t-管状RyR簇密度（~35%），导致IDCM肌细胞中t-管状RyR四聚体减少50%（p < 0.01）。共聚焦显微镜鉴定了所有IDCM心脏中的t-片层，并发现它们与管腔内的网状胶原纤维相关。然而，RyR簇的大小和密度在与t-片层和t-小管相关的肌细胞区域中相似。T-小管重塑与RyR表达减少有关，RyR表达减少可能导致衰竭的人类心脏中兴奋-收缩偶联减少。
The disrupted organisation of the ryanodine receptors (RyR) and junctophilin (JPH) is thought to underpin the transverse tubule (t-tubule) remodelling in a failing heart. Here, we assessed the nanoscale organisation of these two key proteins in the failing human heart. Recently, an advanced feature of the t-tubule remodelling identified large flattened t-tubules called t-sheets, that were several microns wide. Previously, we reported that in the failing heart, the dilated t-tubules up to ~1 μm wide had increased collagen, and we hypothesised that the t-sheets would also be associated with collagen deposits. Direct stochastic optical reconstruction microscopy (dSTORM), confocal microscopy, and western blotting were used to evaluate the cellular distribution of excitation-contraction structures in the cardiac myocytes from patients with idiopathic dilated cardiomyopathy (IDCM) compared to myocytes from the non-failing (NF) human heart. The dSTORM imaging of RyR and JPH found no difference in the colocalisation between IDCM and NF myocytes, but there was a higher colocalisation at the t-tubule and sarcolemma compared to the corbular regions. Western blots revealed no change in the JPH expression but did identify a ~50% downregulation of RyR (p = 0.02). The dSTORM imaging revealed a trend for the smaller t-tubular RyR clusters (~24%) and reduced the t-tubular RyR cluster density (~35%) that resulted in a 50% reduction of t-tubular RyR tetramers in the IDCM myocytes (p < 0.01). Confocal microscopy identified the t-sheets in all the IDCM hearts examined and found that they are associated with the reticular collagen fibres within the lumen. However, the size and density of the RyR clusters were similar in the myocyte regions associated with t-sheets and t-tubules. T-tubule remodelling is associated with a reduced RyR expression that may contribute to the reduced excitation-contraction coupling in the failing human heart.
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影响因子：
3.7
作者：
Crossman DJ;Ruygrok PN;Soeller C;Cannell MB
通讯作者：
Cannell MB
影响因子：
3.4
作者：
Franzini-Armstrong, C;Protasi, F;Ramesh, V
通讯作者：
Ramesh, V
影响因子：
4.8
作者：
Crossman, David J.;Hou, Yufeng;Soeller, Christian
通讯作者：
Soeller, Christian
影响因子：
5.4
作者：
Galice, Samuel;Xie, Yuanfang;Bers, Donald M.
通讯作者：
Bers, Donald M.
影响因子：
5
作者：
Landstrom, Andrew P.;Weisleder, Noah;Ackerman, Michael J.
通讯作者：
Ackerman, Michael J.