Table1_Relationship of PIEZO1 and PIEZO2 vascular expression with diabetic neuropathy.DOCX

Introduction: Diabetic distal symmetric polyneuropathy (DDSP) is the most prevalent form of diabetic peripheral neuropathy, and 25% of patients develop pain in their toes. DDSP is associated with increased cutaneous microvessel density (MVD), reduced skin blood flow, endothelial dysfunction, and impaired fluid filtration with vasodilation. The Piezo family of mechanosensitive channels is known to be involved in the control of vascular caliber by converting mechanical force into intracellular signals. Furthermore, Piezo2 is particularly involved in peripheral pain mechanisms of DDSP patients. To date, very little is known about the number, structure, and PIEZO expression in cutaneous blood vessels (BVs) of individuals with DDSP and their relation with pain and time span of diabetes.Methods and results: We studied microvessels using endothelial markers (CD34 and CD31) and smooth cell marker (α-SMA) by indirect immunohistochemical assay in sections of the glabrous skin of the toes from patients and controls. MVD was assessed through CD34 and CD31 immunoreaction. MVD determined by CD34 is higher in short-term DDSP patients (less than 15 years of evolution), regardless of pain. However, long-term DDSP patients only had increased BV density in the painful group for CD31. BVs of patients with DDSP showed structural disorganization and loss of shape. The BVs affected by painful DDSP underwent the most dramatic structural changes, showing rupture, leakage, and abundance of material that occluded the BV lumen. Moreover, BVs of DDSP patients displayed a Piezo1 slight immunoreaction, whereas painful DDSP patients showed an increase in Piezo2 immunoreaction.Discussion: These results suggest that alterations in the number, structure, and immunohistochemical profile of specific BVs can explain the vascular impairment associated with painful DDSP, as well as the temporal span of diabetes. Finally, this study points out a possible correlation between increased vascular Piezo2 immunostaining and pain and decreased vascular Piezo1 immunostaining and the development of vasodilation deficiency.

引言：糖尿病性远端对称性多发性神经病变（DDSP）是糖尿病周围神经病变中最常见的类型，其中25%的患者足趾会出现疼痛。DDSP与皮肤微血管密度（MVD）增加、皮肤血流减少、内皮功能障碍以及血管扩张时的液体过滤受损有关。Piezo家族的机械敏感性通道被认为在通过将机械力转化为细胞内信号来控制血管口径方面发挥作用。此外，Piezo2在DDSP患者的周围疼痛机制中特别重要。迄今为止，关于DDSP患者皮肤血管（BV）的数量、结构和PIEZO表达，以及它们与疼痛和糖尿病病程的关系，了解甚少。方法与结果：我们通过间接免疫组化检测，使用内皮标记物（CD34和CD31）和平滑肌细胞标记物（α-SMA）研究了患者的足趾无毛皮肤切片中的微血管。MVD通过CD34和CD31的免疫反应进行评估。无论是否有疼痛，短期DDSP患者（病程少于15年）的CD34确定的MVD均较高。然而，长期DDSP患者仅在疼痛组中CD31显示出血管密度增加。DDSP患者的血管表现出结构紊乱和形态丧失。受疼痛影响的DDSP血管经历了最显著的结构变化，表现出破裂、渗漏和堵塞血管腔的物质丰富。此外，DDSP患者的血管显示出Piezo1轻微的免疫反应，而疼痛性DDSP患者显示出Piezo2免疫反应的增加。讨论：这些结果表明，特定血管的数量、结构和免疫组化特征的改变可以解释与疼痛性DDSP相关的血管功能障碍以及糖尿病病程的时间跨度。最后，本研究指出，血管Piezo2免疫染色增加与疼痛以及Piezo1免疫染色减少与血管扩张缺陷发展之间可能存在相关性。