Background

The cutaneous end organ complexes or cutaneous sensory corpuscles are specialized sensory organs associated to low-threshold mechanoreceptors. Mechano-gated proteins forming a part of ion channels have been detected in both the axon and terminal glial cells of Meissner corpuscles, a specific cutaneous end organ complex in the human glabrous skin. The main candidates to mechanotransduction in Meissner corpuscles are members of the Piezo family of cationic ion channels. PIEZO2 has been detected in the axon of these sensory structures whereas no data exists about the occurrence and cell localization of PIEZO1.

Methods

Skin samples (n = 18) from the palmar aspect of the distal phalanx of the first and second fingers were analysed (8 female and 10 males; age range 26 to 61 26–61 years). Double immunofluorescence for PIEZO1 and PIEZO2 together with axonal or terminal glial cell markers was captured by laser confocal microscopy, and the percentage of PIEZOs positive Meissner corpuscles was evaluated.

Results

MCs from human fingers showed variable morphology and degree of lobulation. Regarding the basic immunohistochemical profile, in all cases the axons were immunoreactive for neurofilament proteins, neuron specific enolase and synaptophysin, while the lamellar cells displayed strong S100P immunoreactivity. PIEZO1 was detected co-localizing with axonal markers, but never with terminal glial cell markers, in the 56% of Meissner corpuscles; weak but specific immunofluorescence was additionally detected in the epidermis, especially in basal keratinocytes. Similarly, PIEZO2 immunoreactivity was found restricted to the axon in the 85% of Meissner corpuscles. PIEZO2 positive Merkel cells were also regularly found.

Conclusions

PIEZO1 and PIEZO2 are expressed exclusively in the axon of a subpopulation of human digital Meissner corpuscles, thus suggesting that not only PIEZO2, but also PIEZO1 may be involved in the mechanotransduction from low-threshold mechanoreceptors.

中文翻译：

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人数字迈斯纳小体中 PIEZO1 和 PIEZO2 的免疫组织化学检测

背景

皮肤终末器官复合体或皮肤感觉小体是与低阈值机械感受器相关的特殊感觉器官。在迈斯纳小体的轴突和末端神经胶质细胞中检测到形成离子通道一部分的机械门控蛋白，迈斯纳小体是人类无毛皮肤中的一种特定的皮肤末端器官复合体。迈斯纳小体中机械传导的主要候选者是阳离子离子通道压电家族的成员。已在这些感觉结构的轴突中检测到 PIEZO2，而没有关于 PIEZO1 的出现和细胞定位的数据。

方法

对第一和​​第二手指末节指骨掌侧的皮肤样本 (n = 18) 进行了分析（8 名女性和 10 名男性；年龄范围 26 至 61 26-61 岁）。通过激光共聚焦显微镜捕获 PIEZO1 和 PIEZO2 的双重免疫荧光以及轴突或末端胶质细胞标记物，并评估 PIEZOs 阳性迈斯纳小体的百分比。

结果

来自人类手指的 MC 显示出不同的形态和分叶程度。关于基本免疫组织化学特征，在所有情况下，轴突对神经丝蛋白、神经元特异性烯醇化酶和突触素均具有免疫反应性，而层状细胞则表现出强烈的 S100P 免疫反应性。在 56% 的迈斯纳小体中，检测到 PIEZO1 与轴突标记共定位，但从未与末端胶质细胞标记共定位；在表皮中还检测到微弱但特异性的免疫荧光，特别是在基底角质形成细胞中。同样，PIEZO2 免疫反应性被发现仅限于 85% 迈斯纳小体的轴突。PIEZO2 阳性默克尔细胞也经常被发现。

结论

PIEZO1 和 PIEZO2 仅在人类数字迈斯纳小体亚群的轴突中表达，因此表明不仅 PIEZO2，而且 PIEZO1 可能参与低阈值机械感受器的机械转导。