Research on the correlation of mannose binding lectin (MBL) with diabetes MBLlitus and arteriosclerosis

我们通过凝胶过滤检测了已知MBL基因型的血清，并使用MBL的ELISA评估了它们的洗脱模式，并鉴定了两种MBL形式，高分子量形式和低分子量形式。通过鉴定个体血清中的任一种或两种形式，出现了三种类型的模式：I型由高分子形式组成; 2型由低分子形式组成; 3型由两种形式组成。1型、2型和3型分别对应于野生型（A/A）、密码子54处的纯合突变（BI B）和它们的杂合子（A/B）。与甘露聚糖和MASP-1/3的结合仅发生在高分子形式中。一个明显的MBL缺陷实际上并不代表MBL分子的缺陷，而是存在循环寡聚突变MBL功能受损。MBL与各种免疫球蛋白的结合能力进行了研究。在免疫球蛋白中，相当多的骨髓瘤伊加显示出与MBL的结合能力，其中大多数表现出非常弱或没有能力。IgA与MBL的结合被证实是通过碳水化合物部分。当用唾液酸酶和半乳糖苷酶处理时，与MBL具有弱结合能力或没有结合能力的免疫球蛋白变得与MiIBL反应，表明甘露糖和/或n-乙酰葡糖胺的暴露在与MBL的反应中是必要的。本文观察了四氯化碳对伊加肾病大鼠氧化应激时血清MBL水平的影响。尽管给药后即刻MBL水平严重降低（可能是由于四氯化碳的肝脏容量所致），但在2 - 3天内恢复至先前水平。在使用四氯化碳的情况下，没有观察到氧化应激引起的MBL水平的快速升高。

We examined sera of known MBL genotype by gel-filtration and assesed their elution patterns using an ELISA for MBL and identified two MBL forms, a high molecular weight form and a lower molecular weight form. By the identification of either or both forms in individual sera, three types of patterns emerged: type I consisted of a high molecular form; type 2, of a low molecular form; and type 3, of both forms. Types 1, 2 and 3 corresponded, respectively, to a wild type (A/A), a homozygous mutation at codon 54 (BIB) and their heterozygote (A/B). Binding to mannan and MASP-1/3 occurred exclusively with the high molecular form. An apparent MBL deficiency does not in fact represent a deficiency in MBL molecules but rather the presence of circulating oligomeric mutant MBL with impaired function.Binding ability of MBL with various immunoglobulins was investigated. Among the immunoglobulins, quite a few myeloma IgA showed binding capacity with MBL, and most of them exhibited very weak or no capacity. The binding of the IgAs with MBL was confirmed to be through carbohydrate moieties. The immunoglobulins with weak or no binding capacity with MBL became reactive with MiIBL when they were treated with sialidase and galactosidase, indicating that exposure of mannose and/or n-acetylglucosamine is necessary in the reaction with MBL. It was suggested that some IgAs with some special sugar constitution might play a part in an occur-rence of IgA nephropathy associated with MBL-deposition.The change of the serum MBL level in oxidative stress by oral administration of carbon tetrachioride to rat was inves-tigated. Although the MBL level was severely decreased immediately after the administration possi-bly due to hepatic capacity of carbon tetrachloride, it recovered to the previous level within two to three days. Rapid elevation of MBL level by oxidative stress was not observed in the case using carbon tetrachloride.