Localization of laminin α2 chain in normal human central nervous system: an immunofluorescence and ultrastructural study

Recently, a rare form of congenital muscular dystrophy has been shown to be associated with a deficiency of laminin α2 chain, a tissue-specific component of the basal lamina. Besides muscular dystrophy, children affected with this disorder also show electrophysiological and magnetic resonance imaging evidence of white matter involvement in the central nervous system (CNS). We have studied the precise localization of laminin α2 chain in normal human brain, using specific electron microscopic techniques including thin-section fracture labeling and cryoultramicrotomy, in parallel with immunohistochemical techniques. We found that this laminin chain was localized to the basal lamina of all cerebral blood vessels, whereas blood vessels of the choroid plexus did not show any reaction. No positive reaction was found in meningeal blood vessels either. We hypothesize that in normal brain, laminin α2 may be important for the selective filtration capability of the blood-brain barrier. The lack of laminin α2 in cerebral vessels of children with laminin α2-deficient congenital muscular dystrophy may cause impaired selective filtration, leading to leakage of plasma components and damage to the CNS. Further studies should be performed on patients affected by congenital muscular dystrophy associated with laminin α2 deficiency to test this hypothesis. Received: 2 December 1996 / Revised: 26 March 1997 / Revised, accepted: 3 June 1997     

LAMININ-LIKE IMMUNOREACTIVITY IN INDUCED NEW VESSELS IN KITTEN AND MOUSE EYES

Laminin is a basement membrane glycoprotein, widely distributed in body tissues. It has been found on capillary basement membranes in both developing and adult retinal vessels. Oxygen-induced retinopathy was produced in kittens and mice by exposing them to a high oxygen environment during the newborn period. When the animals developed a proliferative retinopathy after a period of survival in room air, they were sacrificed and the eyes enucleated and embedded in paraffin wax. Cross-sections were cut and de-waxed. After preliminary digestion with pepsin, we used a fluorescein isothiocyanate (FlTC)- labelled double antibody technique to identify laminin-like immunoreactivity (LLlR). LLIR was found on both intravitreal and intraretinal new vessels in the kitten and mouse, indicating that it is probably secreted by endothelial cells during the formation of pathological new vessels .     

Basic fibroblast growth factor expression and tenascin C immunoreactivity after partial unilateral hemitransection of the rat brain

Basic fibroblast growth factor (bFGF) gene expression as well as its immunoreactivity were studied after partial unilateral hemitransection of the rat brain during a time course of 24 h, 72 h, 7 and 14 days. The mechanical injury resulted in a global increase of bFGF gene expression at the 24-h time interval. This global increase was seen at the ipsilateral site at the level of the lesion as well as rostral to the lesion in the ipsilateral hemisphere. The upregulation in bFGF gene expression was in most of the areas investigated due to an upregulation in glial cells as seen by means of nonradioactive in situ hybridization compared with immunocytochemistry for glial fibrillary acidic protein (GFAP). Basic FGF immunoreactivity (IR) was increased around the lesion in glial cell nuclei 7 days after the injury. This increase was also detected in GFAP positive glial cells surrounding small vessels in the lesioned area. Moreover, in the present paper we demonstrate increased tenascin immunoreactivity in the lesioned area 7 days after injury. The tenascin IR was increased at the edges of the lesion as well as in vessel like structures. The tenascin IR was partially codistributed with GFAP IR in the lesioned area. The lesion was also characterized by an increase in vimentin IR as well as in laminin IR. It is suggested that the observed changes in the expression of bFGF, matrix proteins (laminin, tenascin) and intermediate filaments (vimentin) are involved in (a) tissue repair, (b) protection of neuronal cells from excitotoxic influences and (c) formation of new vessels in the lesioned area.     

Immunohistochemistry of proliferating cell nuclear antigen (PCNA), laminin, and electron microscopy by tannic acid fixation in surface epithelial-stromal ovarian tumors

The distribution of proliferating cell nuclear antigen (PCNA), laminin, and basement membrane in surface epithelial-stromal ovarian tumors was studied using immunohistochemical and cytochemical techniques. PCNA is a useful means of differentiating between borderline and malignant tumors. The distribution of laminin-positive materials in malignant tumors showed that laminin synthesis in these tumors is quite different from that which occurs in benign or borderline tumors. This corresponded with electron microscopic findings by tannic acid fixation showing pleomorphism of cell organelles and discontinuity of the basement membrane in malignant tumors.     

血清层粘连蛋白对肝纤维化的诊断价值

目的：观察血清层粘连蛋白（ＬＮ）对肝纤维化的诊断价值。方法：对１１５例不同肝病患者采用双抗体夹心固相酶免疫法检测血清ＬＮ。结果：各种肝病的ＬＮ均有不同程度的升高，其中６４．７１％的慢性迁延型肝炎（慢迁肝），６８．１８％的慢性活动型肝炎（慢活肝）及９４．４４％的肝硬化患者ＬＮ含量明显高于正常对照组。肝硬化患者ＬＮ水平均值与其它各组比较均有显著升高，慢活肝、慢迁肝与急性肝炎组及对照组比较均有显著性差异。结论：提示ＬＮ测定可做为判断肝纤维化或肝硬化的较好指标     

恶性纤维组织细胞瘤LN-R与Cath-D的表达及临床意义

目的：研究层粘连蛋白受体（laminin receptor,LN-R）和组织蛋白酶D（Cathepsin D,Cath-D）在恶性纤维组织细胞瘤（malignant fibrous histiocytoma,MFH）组织中的表达情况,探讨它们之间的关系及临床意义。方法：65例MFH组织标本来自1999年4月至2001年12月哈尔滨医科大学附属肿瘤医院骨科手术患者,其中男40例,女25例;年龄23～78岁（平均年龄54岁）。应用免疫组化方法检测65例MFH组织与10例正常纤维组织中LN-R和Cath-D的蛋白表达情况,分析LN-R与Cath-D在MFH中的表达与MFH临床病理学特征之间的关系,以及二者表达的相关性。结果：光学显微镜下LN-R阳性反应物着色部位主要定位于细胞膜和细胞浆,Cath-D阳性反应物主要定位于细胞浆;65例MFH组织中LN-R和Cath-D蛋白表达阳性率分别为66.2%和75.4%;LN-R和Cath-D在Ⅰ～Ⅱ期的阳性表达率低于Ⅲ～Ⅳ期的阳性表达率,二者统计学差异有显著性（P〈0.05）;LN-R和Cath-D的阳性表达率在高分化明显低于中分化和低分化,表明随着肿瘤病理分化程度的降低,LN-R和Cath-D的阳性表达率也有升高的趋势;10例正常纤维组织中两蛋白均不表达;LN-R和Cath-D的表达与MFH患者的性别、年龄和组织学类型无关;所有病例经过半年至7年随访,平均随访时间为5年,LN-R与Cath-D在术后生存期小于5年的患者中的阳性表达率明显高于生存期大于5年的患者,二者统计学差异有显著性（P〈0.005）;LN-R和Cath-D表达呈显著正相关（P﹤0.01）。结论：LN-R和Cath-D在MFH发生、发展中起重要作用,是判断MFH侵袭力和恶性进展、转移和预后的重要指标。     

Review on the genetics of arrhythmogenic right ventricular dysplasia.

Arrhythmogenic right ventricular dysplasia (ARVD) is a clinical and pathologic entity whose diagnosis rests on electrocardiographic and angiographic criteria; pathologic findings, replacement of ventricular myocardium with fatty and fibrous elements, preferentially involve the right ventricular (RV) free wall. There is a familial occurrence in about 50% of cases, with autosomal dominant inheritance with variable penetrance and polymorphic phenotypic expression, and is one of the major genetic causes of juvenile sudden death. When the dysplasia is extensive, it may represent the extensive form of ARVCM (arrhythmogenic right ventricular cardiomyopathy). In this review, we focus on the some candidate genes mutations and information on some genotype-phenotype correlation in the ARVD. Our findings are in agreement with those of European Society of Cardiology who stated that: genetic analysis is usefull in families with RV cardiomyopathy because whenever a pathogenetic mutation is identified, it becomes possible to establish a presymptomatic diagnosis of the disease among family members and to provide them with genetic counseling to monitor the development of the disease and to assess the risk of transmitting the disease offspring. On the basis of current knowledge, genetic analysis does not contribute to risk stratification of arrhythmogenic RV cardiomyopathy.     

Col-Ⅳ、LN、FN和MMP-9在不同时期婴幼儿型血管瘤中的表达和意义

目的 观察不同时期婴幼儿型血管瘤(infantile hemangioma,IH)中细胞外基质结构蛋白和基质金属蛋白酶-9 (matrix metalloproteinase-9,MMP-9)的表达和分布,探讨基质结构蛋白和MMP-9在IH中潜在的作用和意义.方法 收集手术切除的血管瘤标本,经HE染色和Glut-1免疫组织化学染色后确诊为IH;应用免疫组织化学染色MaxVision法检测各标本中Ⅳ型胶原(Col-Ⅳ)、层黏连蛋白(LN)、纤维连接蛋白(FN)和MMP-9的表达情况,通过ImagePro Plus 6.0图像分析软件测量各组织中阳性染色区域的平均光密度(IOD).按患儿年龄将标本分为年龄＜3个月龄组,≥3～6个月组,≥6～9个月组,≥9～12个月组和≥12个月龄组5组.比较不同年龄组IH中基质结构蛋白和MMP-9表达的差异.结果 按标准纳入的IH共34例,其中月龄＜3个月8例,≥3～6个月7例,≥6～9个月6例,≥9～12个月8例,≥12个月5例.观察免疫组织化学染色结果显示Col-Ⅳ、LN、FN和MMP-9在各年龄组中表达强度不同,比较IOD值显示IH组织中Col-Ⅳ在≥12个月龄组(84.90±12.48)的表达较其他各年龄组高,且与＜3个月龄组(55.10±16.06)、≥3～6个月组(56.96±22.66)、≥6～9个月组(51.60±20.38)比较差异有统计学意义(P＜0.05).LN在≥9～12个月组(80.04±29.36)IH中表达最高,分别与＜3个月龄组(38.02±9.88)、≥3～6个月组(68.62±16.19)、≥6～9个月组(60.67±10.72)、月龄≥12个月组(45.96±5.02)比较差异均有统计学意义(P＜0.05).FN在≥6～9个月组(62.86±15.41) IH中表达最高,分别与＜3个月龄组(32.36±19.79)、≥3～6个月组(43.04±19.78)、≥9～12个月组(36.25±11.19)、月龄≥12个月组(27.57±13.90)比较差异有统计学意义(P＜0.05).MMP-9在＜3个月龄组(73.23±18.19)IH组织中表达最高,并随年龄增长≥3～～6个月组(59.31±12.85)、≥6～9个月组(35.80±7.50)、≥9～12个月组(26.89±10.21)、月龄≥12个月组(24.04±10.00)逐渐下降,其中＜3个月龄组、≥3～6个月组IH与其他各组比较差异有统计学意义(P＜0.05).结论 不同时期IH组织中Col-Ⅳ、LN、FN和MMP-9的表达有差异,这种差异可能是影响IH增生和消退的重要因素.     

IMMUNOHISTOCHEMICAL STUDIES OF DMBA-INDUCED RAT MAMMARY TUMORS

In order to clarify the biological characteristics of rat mammary tumors induced by 7, 12-dimethylbenz- [a] -anthracene (DMBA), histochemical and immunohistochemical studies were performed. Two types of luminal spaces were observed within the tumor. In one type, the lumen was surrounded by eosinophilic columnar cells which were strongly reactive for soybean agglutinin (SBA) but weakly stained with keratin antibodies. In the luminal spaces, substances positive for PAS, dialyzed iron ferrocyanide or alcian blue and resistant to mucopolysaccharidase were occasionally observed. Ultrastructurally, the luminal surface was characterized by the presence of microvilli and tight junctions. In the other type, the lumen was often found in highly cellular foci and surrounded by pale, polygonal or elongated cells which were weakly stained with keratin antibodies but not SBA. The luminal spaces presented a peculiar structure filled mainly with mucoid substances sensitive to hyal-uronidase, chondroitinase ABC and heparitinase, and the inner surface of the spaces was surrounded by basement membrane components: laminin, fibronectin and type IV collagen. The results of the present study therefore showed that DMBA-induced mammary tumor consists, partly, of a structure resembling human adenoid cystic carcinoma. ACTA PATHOL JPN 38 : 129 -139, 1988.   Key words:     

Altered expression of natively glycosylated alpha dystroglycan in pediatric solid tumors

Altered glycosylation and/or expression of dystroglycan have been reported in forms of congenital muscular dystrophy as well as in cancers of the breast, colon, and oral epithelium. To date, however, there has been no study of the expression of dystroglycan in pediatric solid tumors. Using a combination of immunostaining on tissue microarrays and immunoblotting of snap-frozen unfixed tissues, we demonstrate a significant reduction in native alpha dystroglycan expression in pediatric alveolar rhabdomyosarcoma (RMS), embryonal RMS, neuroblastoma (NBL), and medulloblastoma, whereas expression of beta dystroglycan, which is cotranslated with alpha dystroglycan, is largely unchanged. Loss of native alpha dystroglycan expression was significantly more pronounced in stage 4 NBL than in pooled samples of stage 1 and stage 2 NBL, suggesting that loss of native alpha dystroglycan expression increases with advancing tumor stage. Neuroblastoma and RMS samples with reduced expression of native alpha dystroglycan also showed reduced laminin binding in laminin overlay experiments. Expression of natively glycosylated alpha dystroglycan was not altered in several other pediatric tumor types when compared with appropriate normal tissue controls. These data provide the first evidence that alpha dystroglycan glycosylation and laminin binding to alpha dystroglycan are altered in certain pediatric solid tumors and suggest that aberrant dystroglycan glycosylation may contribute to tumor cell biology in patients with RMS, medulloblastoma, and NBL.