Department of Otorhinolaryngology-Head and Neck Surgery, Inje University, College of Medicine, Busan Paik Hospital, Busan, Korea.
Am J Rhinol Allergy. 2011 Jan-Feb;25(1):12-4. doi: 10.2500/ajra.2011.25.3555.
Chitin is a recognition element for tissue infiltration by innate cells implicated in allergy and immunity. This process can be negatively regulated by vertebrate chitinases. Both acidic mammalian chitinase (AMCase) and chitotriosidase (ChT) have chitinolytic activity. This study aimed to determine the activities of AMCase and ChT in nasal polyps (NPs), as well as their in situ localization in NP tissue.
AMCase and ChT activities in NPs were compared with those in inferior turbinate tissue samples. Tissue samples were measured for AMCase and ChT activities at a range of pHs using the fluorogenic substrate 4-methylumbelliferyl-beta-d-N,N',N''-triacetyl-chitotriose. Double immunofluorescent staining for the localization of both AMCase and ChT was performed using NP cryosections.
Both AMCase and ChT displayed markedly increased chitinolytic activity in all NPs, compared with inferior turbinate tissues. Double immunofluorescent staining revealed that CD68 highlighted monocytes in the submucosa of NP and these cells disclosed coexpression of AMCase and ChT. CD31 detected capillary endothelial cells, but did not express any AMCase and ChT.
The increased chitinolytic activities of AMCase and ChT in NPs may be important in NP pathogenesis, suggesting that inhibition of chitinolytic activity may be a novel therapeutic strategy for the treatment of NPs.
几丁质是参与过敏和免疫的固有细胞组织浸润的识别元素。这一过程可以被脊椎动物几丁质酶负调控。酸性哺乳动物几丁质酶（AMCase）和壳三糖苷酶（ChT）都具有几丁质酶活性。本研究旨在确定鼻息肉（NPs）中的 AMCase 和 ChT 活性及其在 NP 组织中的原位定位。
比较了 NPs 中 AMCase 和 ChT 活性与下鼻甲组织样本中的活性。使用荧光底物 4-甲基伞形酮-β-D-N，N'，N''-三乙酰壳三糖苷，在一系列 pH 值下测量 AMCase 和 ChT 活性。使用 NP 冷冻切片进行 AMCase 和 ChT 定位的双重免疫荧光染色。
与下鼻甲组织相比，所有 NPs 中的 AMCase 和 ChT 均显示出明显增加的几丁质酶活性。双重免疫荧光染色显示，CD68 突出显示 NP 黏膜下层的单核细胞，这些细胞显示 AMCase 和 ChT 的共表达。CD31 检测到毛细血管内皮细胞，但不表达任何 AMCase 和 ChT。
NPs 中 AMCase 和 ChT 的几丁质酶活性增加可能在 NP 发病机制中很重要，表明抑制几丁质酶活性可能是治疗 NPs 的一种新的治疗策略。
