Ashby M T
Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA.
J Dent Res. 2008 Oct;87(10):900-14. doi: 10.1177/154405910808701003.
The innate host response system is comprised of various mechanisms for orchestrating host response to microbial infection of the oral cavity. The heterogeneity of the oral cavity and the associated microenvironments that are produced give rise to different chemistries that affect the innate defense system. One focus of this review is on how these spatial differences influence the two major defensive peroxidases of the oral cavity, salivary peroxidase (SPO) and myeloperoxidase (MPO). With hydrogen peroxide (H(2)O(2)) as an oxidant, the defensive peroxidases use inorganic ions to produce antimicrobials that are generally more effective than H(2)O(2) itself. The concentrations of the inorganic substrates are different in saliva vs. gingival crevicular fluid (GCF). Thus, in the supragingival regime, SPO and MPO work in unison for the exclusive production of hypothiocyanite (OSCN(-), a reactive inorganic species), which constantly bathes nascent plaques. In contrast, MPO is introduced to the GCF during inflammatory response, and in that environment it is capable of producing hypochlorite (OCl(-)), a chemically more powerful oxidant that is implicated in host tissue damage. A second focus of this review is on inter-person variation that may contribute to different peroxidase function. Many of these differences are attributed to dietary or smoking practices that alter the concentrations of relevant inorganic species in the oral cavity (e.g.: fluoride, F(-); cyanide, CN(-); cyanate, OCN(-); thiocyanate, SCN(-); and nitrate, NO(3)(-)). Because of the complexity of the host and microflora biology and the associated chemistry, it is difficult to establish the significance of the human peroxidase systems during the pathogenesis of oral diseases. The problem is particularly complex with respect to the gingival sulcus and periodontal pockets (where the very different defensive stratagems of GCF and saliva co-mingle). Despite this complexity, intriguing in vitro and in vivo studies are reviewed here that reveal the interplay between peroxidase function and associated inorganic chemistry.
固有宿主反应系统由多种机制组成，用于协调宿主对口腔微生物感染的反应。口腔的异质性以及由此产生的相关微环境会产生不同的化学性质，从而影响固有防御系统。本综述的一个重点是这些空间差异如何影响口腔的两种主要防御过氧化物酶，即唾液过氧化物酶（SPO）和髓过氧化物酶（MPO）。以过氧化氢（H₂O₂）作为氧化剂，防御过氧化物酶利用无机离子产生抗菌物质，这些抗菌物质通常比H₂O₂本身更有效。唾液与龈沟液（GCF）中无机底物的浓度不同。因此，在龈上区域，SPO和MPO协同作用，专门产生次硫氰酸盐（OSCN⁻，一种活性无机物质），它不断地浸润新生菌斑。相反，在炎症反应期间，MPO会进入GCF，在这种环境中它能够产生次氯酸盐（OCl⁻），这是一种化学性质更强的氧化剂，与宿主组织损伤有关。本综述的第二个重点是可能导致过氧化物酶功能不同的个体间差异。其中许多差异归因于饮食或吸烟习惯，这些习惯会改变口腔中相关无机物质的浓度（例如：氟化物，F⁻；氰化物，CN⁻；氰酸盐，OCN⁻；硫氰酸盐，SCN⁻；以及硝酸盐，NO₃⁻）。由于宿主和微生物生物学以及相关化学性质的复杂性，很难确定人类过氧化物酶系统在口腔疾病发病机制中的意义。对于龈沟和牙周袋（GCF和唾液非常不同的防御策略在此混合）来说，这个问题尤其复杂。尽管存在这种复杂性，但本文还是综述了一些有趣的体外和体内研究，这些研究揭示了过氧化物酶功能与相关无机化学之间的相互作用。
