A Novel Monoclonal Antibody to Human Laminin α5 Chain Strongly Inhibits Integrin-Mediated Cell Adhesion and Migration on Laminins 511 and 521

Laminins, a large family of αβγ heterotrimeric proteins mainly found in basement membranes, are strong promoters of adhesion and migration of multiple cell types, such as tumor and immune cells, via several integrin receptors. Among laminin α (LMα) chains, α5 displays the widest tissue distribution in adult life and is synthesized by most cell types. Here, we have generated and characterized five novel monoclonal antibodies (mAbs) to the human LMα5 chain to further study the biological relevance of α5 laminins, such as laminins 511 (α5β1γ1) and 521 (α5β2γ1). As detected by ELISA, immunohistochemistry, immunoprecipitation and Western blotting, each antibody displayed unique properties when compared to mAb 4C7, the prototype LMα5 antibody. Of greatest interest, mAb 8G9, but not any other antibody, strongly inhibited α3β1/α6β1 integrin-mediated adhesion and migration of glioma, melanoma, and carcinoma cells on laminin-511 and, together with mAb 4C7, on laminin-521. Accordingly, mAb 8G9 abolished the interaction of soluble α3β1 integrin with immobilized laminins 511 and 521. Binding of mAb 8G9 to laminin-511 was unaffected by the other mAbs to the LMα5 chain but largely hindered by mAb 4E10 to a LMβ1 chain epitope near the globular domain of laminin-511. Thus, mAb 8G9 defines a novel epitope localized at or near the integrin-binding globular domain of the LMα5 chain, which is essential for cell adhesion and migration, and identifies a potential therapeutic target in malignant and inflammatory diseases.     

Synergistic Effect of Fadrozole and Insulin-Like Growth Factor-I on Female-To-Male Sex Reversal and Body Weight of Broiler Chicks

The aim of this study was to investigate the effects of Fadrozole hydrochloride and recombinant human insulin-like growth factor I (rhIGF-I) on female-to-male sex reversal, hatching traits, and body weight of broiler chickens. On the third day of incubation, fertile eggs were randomly assigned to five experimental groups comprising (i) Fadrozole (0.1 mg/egg), (ii) rhIGF-I (100 ng/egg), (iii) Fadrozole (0.1 mg/egg) + rhIGF-I (100 ng/egg), (iv) vehicle injection (10 mM acetic acid and 0.1% BSA), and (v) non-injected eggs. Eggs in the rhIGF-I-injected groups showed the mode of hatching time at the 480th hour of incubation, 12 hours earlier compared to the other groups, with no statistically significant difference in mortality and hatchability. On Day 1 and 42 of production, 90% of genetically female chicks were masculinized using Fadrozole treatment, while 100% female-to-male phenotypic sex reversal was observed in the Fadrozole+rhIGF-I group. Fadrozole equalized the body weight of both genders, although rhIGF-I was effective on the body weight of male chicks only. Interestingly, combined rhIGF-I and Fadrozole could increase the body weight in both sexes compared to the individual injections (P<0.05). These findings revealed that (i) IGF-I-treated chicken embryos were shown to be an effective option for overcoming the very long chicken deprivation period, (ii) the simultaneous treatment with Fadrozole and IGF-I could maximize the female-to-male sex reversal chance, (iii) the increase in the body weight of masculinized chickens via Fadrozole could be equal to their genetically male counterparts, and (iv) the IGF-I effectiveness, specifically along with the application of aromatase inhibitors in female chicks, indicates that estrogen synthesis could be a stumbling block for the IGF-I action mechanism in female embryos.     

Membrane receptors in the gastrointestinal tract

This review focusses on the roles that membrane receptors and their transducers play in the physiology and pathology of the gastrointestinal tract. The multifactorial: factorial regulation of mucosal growth and function is discussed in relation to the heterogeneity of exocrine and endocrine populations that originate from progenitor cells in stomach and intestine.     

Investigation of gonadotropin-thyrotropin overlapping and hormonal imprinting in the rat testis

In the neonatal period both gonadotropin and thyrotropin increase the weight of the testis, influence considerably the diameter of the contorted tubules increase the occurrence of Sertoli cells and decrease the number of spermatogonia. These phenomena can still be observed at the age of seven days but they disappear by the age of six weeks; at that time the hormones decrease the weight of the testis. One single TSH treatment administered in the neonatal period considerably increased the weight of the testis and the diameter of the channels when investigated at the age of six weeks. Gonadotropin had none of these effects. The phenomenon of imprinting could be proved as in the animals pretreated with TSH, gonadotropin given at the age of six weeks decreased the weight of the testis and both hormones decreased the diameter of the seminiferous cords.     

Phylogeny and character evolution in Medicago (Leguminosae): Evidence from analyses of plastid trnK/matK and nuclear GA3ox1 sequences

? Premise of the study: The genus Medicago, with about 87 species, includes the model legume species M. truncatula, and a number of important forage species such as M. sativa (alfalfa), M. scutellata (snail medic), and M. lupulina (black medic). Relationships within the genus are not yet sufficiently resolved, contributing to difficulty in understanding the evolution of a number of distinguishing characteristics such as aneuploidy and polyploidy, life history, structure of cotyledons, and number of seeds per fruit. ? Methods: Phylogenetic relationships of 70-73 species of Medicago and its sister genus Trigonella (including Melilotus) were reconstructed from nucleotide sequences of the plastid trnK/matK region and the nuclear-encoded GA3ox1 gene (gibberellin 3-β-hydroxylase) using maximum parsimony and Bayesian inference methods. ? Key results: Our results support certain currently recognized taxonomic groups, e.g., sect. Medicago (with M. sativa) and sect. Buceras. However, other strongly supported clades-the "reduced subsection Leptospireae clade" that includes M. lupulina, the "polymorpha clade" that includes M. murex and M. polymorpha and the "subsection Pachyspireae clade" that includes M. truncatula-each of which includes species presently in different subsections of sect. Spirocarpos, contradict the current classification. ? Conclusions: These results support the hypothesis that some characters considered important in existing taxonomies, for example, single-seeded fruits that have arisen more than once in both Medicago and Trigonella, are indeed homoplastic. Others, such as the 2n = 14 chromosome number, have also arisen independently within the genus. In addition, we demonstrate support for the utility of GA3ox1 sequences for phylogenetic analysis among and within closely related genera of legumes.     

Pollen morphology of the genus Gagea (Liliaceae) in Iran

Pollen grains of 26 species of the genus Gagea distributed in Iran were examined by light and scanning electron microscopy. Detailed pollen morphological characteristics are given for these species. Among the studied species, the newly described G. iranica together with G. olgae and G. graminifolia possess the smallest pollen grains, and the widely distributed G. lutea the largest ones. Our studies show that the sculpturing of exine provides valuable characters for separating the species, sometimes even for closely related ones, and delimitation of natural groups within the genus. The exine of the genus Gagea is in most cases perforated upon tectum or rarely tectate-columellate. The muri are solid or structured, compound, simpli-, dupli- or pluricolumellate. It seems that the structure of muri is very important in recognizing natural groups within the genus. Tectal perforations vary from <0.2 to 2.0 μm in diameter among the studied species. Regarding sculpturing of the exine in proximal face, four basic types of pollen grains can be distinguished: reticulate, microreticulate, foveolate and perforate. Within the reticulate type there is sufficient variation in exine structure at distal face to describe three subtypes: reticulate, microreticulate and perforate. A diagnostic key is given for all studied taxa based on palynomorphological characters. For a limited number of populations of selected Iranian species of Gagea, further aspects of pollen biology were studied. It seems that populations with ploidy levels other than diploidy, show a low percentage of pollen fertility. Moreover, the rate of pollen fertility is correlated with the manner of the reproduction in certain species.