Laminin alpha-1, alpha-3, and alpha-5 chain expression in human prepubertal [correction of prepubetal] benign prostate glands and adult benign and malignant prostate glands

BACKGROUND: Laminins (Lns) are a family of extracellular matrix glycoproteins located in the basement membrane (BM) of epithelial cells. They exist as heterotrimers composed of an alpha, beta, and gamma chain. Presently, five alpha (alpha1-5), three beta (beta1-3), and three gamma (gamma1-3) chains have been identified with different combinations of these chains resulting in 14 laminin heterotrimers thus far identified (1, 3-5). METHODS: In this study, using immunohistochemistry with chain-specific antibodies, we characterized the expression of the alpha1 (Lns-1/3), alpha3 (Lns 5,6,7), and alpha5 (Lns 10/11) chains in fetal, newborn, infant, prepubertal, and adult benign and malignant prostate glands. RESULTS: In general, alpha1 expression was higher in normal fetal prostate glands and declined by full-term birth, whereas the alpha3 and alpha5 chains remained highly expressed in the adult normal glands. In carcinoma alpha1 (Lns 1/3) and alpha5 (Lns 5,6,7) are lost, whereas alpha5 (Lns 10/11) persists. CONCLUSIONS: Alpha 1 (Lns 1/3) is prominent in BM, but is replaced by a laminin matrix rich in alpha3 (Lns 5,6,7) and alpha5 (Lns 10/11) in benign adult prostate glands. In carcinoma, both alpha1 (Lns-1/3) and alpha3 (Lns 5,6,7) are not expressed with persistence of a BM rich in alpha5 (Lns 10/11).     

Dystroglycan: Emerging Roles in Mammary Gland Function

Dystroglycan (DG) is a single receptor that binds to multiple basement membrane proteins and forms a transmembrane link to the actin cytoskeleton. It was first isolated as a component of the dystrophin-glycoprotein complex, which plays a role in the maintenance of muscle cell integrity and is defective in many muscular dystrophies. Although studied most extensively in muscle tissues, DG is present at most cell-basement membrane interfaces, and only recently has investigation of DG functions in nonmuscle cells gained momentum. Information emerging from recent studies in epithelial cells is implicating DG in a wide range of critical cell responses to the basement membrane, ranging from organization of tissue architecture to cell survival. Moreover, DG functions appear to be frequently absent in carcinoma cells, implicating its loss in cancer progression. Although many questions remain as to its precise role in mammary tissue, DG is emerging as a potentially important player in mammary gland function.     

Tendon chitosan tubes covalently coupled with synthesized laminin peptides facilitate nerve regeneration in vivo

We have developed tendon chitosan tubes having the ability to bind peptides covalently, and the effectiveness of laminin peptides coupled to these tubular wall on nerve regeneration was examined in vivo. Bridge graft implantation (15 mm) into the sciatic nerve of SD rats was carried out using chitosan tubes having a triangular cross section containing either covalently bound intact laminin or the laminin peptides CDPGYIGSR or CSRARKQAASIKVAVSAD or being nontreated (N = 20 in each group). As a control, isografting (N = 5) was carried out. Three rats in each experimental group were sacrificed for histology observations after 1, 2, 4, 6, and 8 weeks. The total area of regenerating tissue in the tube and the length of the area where regenerating tissue attached to the inner surface of the tube were measured. In five rats from each experimental and control group, the latency quotient between the implanted and the nontreated site was determined 12 weeks after implantation. Furthermore, the percentage of myelinated axon area was measured at a 10-mm distance from the distal anastomosed site. Histological findings suggest that the immobilized laminin, confirmed by immunostaining as long as 12 weeks postoperatively, as well as laminin oligopeptides may effectively assist nerve tissue extension. According to statistical analysis of the percentage neural tissue found in relation to evoked action potentials, the sequential treatments with YIGSR first followed by IKVAV matched the effectiveness of intact laminin in enhancing nerve regeneration. However, when compared with that after isografting, the enhancement of regenerated axon growth was less sufficient.     

Immunohistochemical localization of calbindin D-28k in the migratory pathway from the rat olfactory placode

The spatiotemporal localization of calbindin D-28k (Calb), a calcium-binding protein, was examined immunohistochemically in the developing rat olfactory system with special reference to cell migration from the olfactory placode. Calb immunoreactivity was first detected at embryonic day 12 (E12) in a few cells just outside the olfactory epithelium, and at E13, Calb-immunoreactive cells were found scattered in the laminin-rich mesenchyme. By E14, Calb-immunoreactive cells had increased in number and were seen along the entire migratory route between the vomeronasal organ, a derivative of the medial olfactory pit, and the ventromedial surface of the telencephalic vesicle. Calb neurones were not seen in the olfactory epithelium, a derivative of the lateral olfactory pit. Although the distribution pattern of Calb-immunoreactive cells was similar to that of luteinizing hormone releasing hormone (LHRH)-producing neurones, which are known to originate in the vomeronasal organ and migrate into the forebrain, Calb and LHRH immunoreactivities were contained in separate neuronal populations. Calb-immunoreactive cells were localized along the vomeronasal nerves, identified by labelling the vomeronasal organ with the lipophilic dye, DiI, and strongly immunoreactive for neural cell adhesion molecule (NCAM). These data strongly suggest that, in addition to LHRH neurones, the rat vomeronasal organ generates Calb-immunoreactive neurones which migrate along the vomeronasal nerves to enter the forebrain. The final fate and functional importance of these cells remains to be determined.     

Protease Digestion Shortens Procedure for the Demonstration of Laminin

Abstract

Protease type XIV was found to be a suitable substitute for pepsin digestion in the immunohistochemical demonstration of laminin. The method enables pathologists to distinguish vascular spaces from artifactual tissue spaces, which has prognostic value in the evaluation of tumors. The authors speculate that protease type XIV has multiple action sites that uncover antigenic binding sites more quickly than pepsin does. (The J Histotechnol 10: 185, 1987).     

Ⅳ型胶原等几种细胞外基质在腮腺血管瘤中表达的研究

通过检测 型胶原、层粘连蛋白及纤维粘连蛋白等细胞外基质在腮腺血管瘤中的表达 ,探讨它们与血管瘤发生、发展的关系。方法 :采用高敏感 SP免疫组化定位及计算机图像定量分析方法 ,观察它们在腮腺血管瘤的表达变化。结果 :三者主要位于小血管及增生的腺管周围 ,连续线状分布 ;且三者在血管瘤组织中均呈高表达。结论 :细胞外基质与腮腺血管瘤的发生、发展密切相关     

大鼠实验性脑室出血后LN及LNR-1在脑内的表达及意义

目的观察大鼠脑室出血后层粘蛋白（LN）及其受体LNR-1在大鼠脑内的表达变化，探讨其与出血后慢性脑积水之间的关系。方法将大鼠随机分为3组：正常对照组、假手术对照组、实验组，将枸橼酸化的0．1ml自体静脉血注入实验组大鼠侧脑室内建立出血后慢性脑积水模型（假手术组注入0．1ml生理盐水），采用免疫组化方法观察出血后不同时间LN及LNR-1在脑内的表达变化。结果实验组30d出现脑积水为80％（4／5）、其余组别未出现慢性脑积水；实验组出血后LN在纵裂池、软脑膜、蛛网膜、硬膜、脑内毛细血管壁、蛛网膜下腔血管壁的表达在3d时增加，7d表达继续增加，14d表达最强，较对照组、假手术组显著增强（P〈0．01），30d仍强烈表达；实验组出血后LNR-1在脉络丛的立方上皮细胞胞浆及顶质膜、室管膜细胞、软脑膜细胞、蛛网膜细胞、硬膜、纵裂池、胶质细胞的表达增加。LNR-1在蛛网膜下腔的表达变化与LN基本一致。结论大鼠脑室出血后LN及LNR-1的表达上调可能参与蛛网膜纤维化的过程，从而在出血后慢性脑积水的形成中发挥重要作用。     

S型凝集素影响肿瘤细胞在细胞外基质上的粘着

目的：探讨肿瘤细胞表面Ｓ型凝集素在肿瘤细胞粘着于基膜中的作用。方法：测定乳糖等对小鼠黑色素瘤Ｂ１６细胞粘着于细胞外基质的影响。结果：小鼠黑色素瘤凝集素（ＭＭＡ）促进细胞粘着；抗ＭＭＡ抗体及乳糖明显抑制Ｂ１６细胞粘着于细胞外基质及层粘连蛋白；然而，ＭＭＡ等不影响Ｂ１６细胞粘着于纤粘连蛋白及ＩＶ型胶原蛋白。结论：肿瘤细胞表面Ｓ型凝集素参与肿瘤细胞粘着于基膜。     

Basement membrane and the SIKVAV laminin-derived peptide promote tumor growth and metastases

Summary Laminin, the major glycoprotein component of basement membrane, promotes the malignant phenotype. Cells which are adherent to laminin are more malignant than the non-adherent cells and in certain tumor cells, the number of laminin receptors is positively correlated with malignancy. Laminin also increases collagenase IV activity, an enzyme demonstrated to be critical for tumor spread. A site on laminin, containing the amino acid sequence SIKVAV, has been identified which when injected intravenously with B16F10 melanoma cells, causes an increase in the number of colonies on the surface of the lungs. This peptide does not affect tumor cell arrest in the vasculature or the immune system. It does promote angiogenesis in various in vitro and in vivo models, thereby facilitating tumor cell survival.When a complex mixture of laminin-enriched basement membrane components (Matrigel) is coinjected with tumor cells subcutaneously, tumor incidence and growth increases. Various tumor cell lines and primary isolates, which previously could not form tumors in mice, can be induced to grow rapidly in the presence of Matrigel. Slowly growing tumors or arrested tumors can also be induced to grow more quickly with additional injections of Matrigel. When an SIKVAV-containing synthetic peptide is coinjected with B16F10 tumor cells and Matrigel subcutaneously in mice, larger tumors are formed than that observed with either Matrigel or cells alone. Such studies define the role of laminin in tumor growth and spread and generate new models for studying therapeutic agents. Of particular interest is the ability to grow primary isolates which generally do not grow in mice.