RESEARCH ON THE MOLECULAR MECHANISM UNDERLYING THE TRANSMISSION PHENOMENON IN AMYLOIDOSES INVOLVING HUMAN NEUROLOGICAL SYSTEMS

淀粉样变性是由蛋白质结构紊乱引起的一组疾病，在这种疾病中，通常可溶的蛋白质以不可溶的淀粉样纤维的形式沉积在组织中，这些纤维由β折叠的片状物质组成。成核依赖聚合或播种被认为是包括豌豆疾病在内的几种淀粉样变性中纤维形成的一种模式。据报道，在几种类型的淀粉样变性中，由于注射淀粉样纤维而加速淀粉样蛋白沉积和疾病的传递性，如Pron病、小鼠ApoAII淀粉样变性和小鼠淀粉样变性AA淀粉样变性。遗传性转甲状腺激素相关家族性淀粉样多发性神经病(FAP)家系表现出遗传预见性，在世代中TTR-淀粉样蛋白沉积的年龄较早。值得注意的是，受影响母亲的后代似乎比受影响父亲的后代更容易怀孕。脂肪中预期的分子基础仍有待确定。我们假设…FAP的更多预期可能是由于受影响的母亲向其后代传递TTR-淀粉样纤维引起的，本研究的目的是验证这一假说。首先，我们调查了三名女性FAP患者的乳腺组织，她们被证实在腹部脂肪组织中有淀粉样沉积。刚果红染色可见数量不等的淀粉样蛋白沉积，乳腺中淀粉样蛋白沉积的70%与患者的临床70%几乎成正比。淀粉样蛋白沉积主要见于乳腺的上皮部，围绕形成肺泡的腺体上皮细胞。此外，在一些肺泡内，肺泡上皮细胞脱落，沉积的淀粉样蛋白直接靠近或突出到肺泡腔内。我们认为乳腺中的淀粉样沉积，特别是那些直接与腺腔中的牛奶接触的沉积，可能是可传递给母乳喂养后代的淀粉样纤维的来源。其次，我们询问了从具有突变TTR(Val30Met)的FAP患者中提取的TTR-淀粉样纤维(ATTR)是否会加速表达导致FAP的人类突变TTR基因的转基因小鼠的ATTR沉积。根据Pras和他的同事的说法，从一名FAP杂合子正常和Va130Met变异TTRs的日本患者的尸检心脏中分离出ATTR纤维作为水悬浮组分。将分离的淀粉样蛋白纤维注射到8-13岁转基因小鼠的尾静脉中。将等量的DW注射给与对照组相同年龄的转基因小鼠。4个月或12个月后，用乙醚麻醉处死转基因小鼠。切除各种组织，进行病理检查。注射TTR12个月后，5只转基因小鼠的食道、胃、肠、肺、肝、肾、心脏等组织均可见嗜多形性淀粉样蛋白沉积，而注射DW的5只对照小鼠均未见淀粉样蛋白沉积。这一结果清楚地表明，从FAP患者心脏提取的Attr纤维在体内具有促进淀粉样变性的活性。在免疫组织化学分析中，所有5只注射Attr的转基因小鼠的淀粉样蛋白沉积只与抗鼠ApoAII抗体反应，而不与抗人TtR抗体反应。这些结果表明，给予人的Attr纤维确实加速了小鼠ApoAII淀粉样蛋白的沉积，而不是同样的人类Attr。较少

Amyloidoses are a group of diseases caused by the structural disorder of proteins in which normally soluble proteins are deposited in tissues as insoluble amyloid fibrils made up of β-pleated sheets. Nucleation dependent polymerization or seeding is postulated as a model of fibril formation in several kinds of amyloidoses including peon diseases. Acceleration of amyloid deposition by administration of amyloid fibrils and transmissibility of the disease have been reported in several types of amyloidoses, such as prion diseases, mouse AApoAII amyloidosis and mouse amyloid AA amyloidosis. Families with transthyretin (TTR)-associated familial amyloidotic polyneuropathy (FAP) exhibit genetic anticipation, with TTR-amyloid depositing at an earlier age in successive generations. Notably, descendents of affected mothers appear to be more prone to anticipation than descendents of affected fathers. The molecular bases of anticipation in FAT have remained to be determined. We hypothesized that th … More e anticipation in FAP may be caused by transmission of TTR-amyloid fibrils from affected mothers to their offspring, and the purpose of this study was to examine this hypothesis.First, we investigated mammary gland tissues of three female patients with FAP who were proven to have amyloid deposition in abdominal fat tissues. There was a variable amount of amyloid deposition positively stained with Congo red, and the seventies of the amyloid deposition in mammary glands were almost proportional to the clinical seventies of the patients. Amyloid deposition was seen mainly in the epithelial portion of the mammary gland, surrounding the glandular epithelial cells that form the alveoli. Furthermore, in some alveoli, alveolar epithelial cells were detached so that deposited amyloid was directly adjacent to or projecting into the lumen of the alveoli. We consider that amyloid deposits in mammary glands, especially those that directly come in contact with milk in the glandular lumens, may be the source of amyloid fibrils that could be transmitted to breast-fed offspringSecondly, we asked if administration of TTR-amyloid fibrils (ATTR) extracted from an patient with FAP having variant TTR (Val30Met) would accelerate ATTR deposition in transgenic mice expressing the human mutant ttr gene responsible for FAP. The ATTR fibrils were isolated according to Pras and colleagues as water suspension fractions from an autopsied heart of a Japanese patient with FAP heterozygous with normal and Va130Met variant TTRs. The isolated amyloid fibrils were injected into the tail veins of 8-13-mounth-old transgenic mice. An equal volume of DW was injected into transgenic mice of the same age as controls. After 4 or 12 months, the transgenic mice were killed following anesthetization with ether. Various tissues were excised and subjected to pathological examinations. Twelve months after injection, congophilic amyloid deposits were observed in the various tissues (esophagus, stomach, intestine, lung, liver, kidney, heart) of all the 5 transgenic mice injected with TTR, whereas no deposits were detected in any of the five control transgenic littermates injected with DW. This results clearly showed that ATTR fibrils extracted from the heart of an FAP patient exerted amyloidosis-accelerating activity in vivo. In immunohistochemical analyses, the amyloid deposits in all the five ATTR-injected transgenic mice reacted only with anti-mouse AApoAII antibody, not with anti-human TTR antibody. These results indicated that administration of human ATTR fibrils did accelerate deposition of mouse AApoAII amyloid, and not the same human ATTR. Less