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5. Ultrastructural evidence that basally located cells in the epididymal epithelium constitute distinct cell types with unique gene regulators

Author

Hermo, L., Oliveira, R., Dufresne, J., Gregory, M., Cyr, Daniel G, McGill University = Université McGill [Montréal, Canada], Institut Armand Frappier (INRS-IAF), and Réseau International des Instituts Pasteur (RIIP)-Institut National de la Recherche Scientifique [Québec] (INRS)

Subjects
[SDV]Life Sciences [q-bio]
Abstract

International audience; The epididymal epithelium contains several distinct basally located cells, including basal cells, CD11c+ dendritic cells and monocytic/F4/80‐positive macrophages. All of these cells appear inconspicuous by LM in contrast to the dominant principal cells spanning the length of the epithelium. However, evidence based on EM observations that would substantiate distinguishing features of diverse populations of basally located cells is lacking. Basal cells, initially highlighted by the glutathione S transferase marker GST‐Yf, were also characterized by expression of Keratin 5 and claudin 1 (Cldn1). Basal cells were small elongated or spherical cells with corresponding nuclear shapes, contacting the basement membrane (BM) and revealing sparse ER cisternae, few small dense lysosomes, but an abundance of polysomes, all features suggestive of undifferentiated cells. Gene profiling classified them as potential stem cells as evidenced by expression of the p63 transcription factor, which was not found in principal cells. p63 regulated several classes of genes, including Cldn1. ChIP studies indicated that p63 bound to two response elements located on the promoter region of the Cldn1 gene, which may serve to regulate high expression levels of this gene in basal cells and account for their unique features. In addition to classic basal cells, by EM, a second population of basally located cells demonstrated a strikingly different morphology. Such cells contacting the BM occupied a larger space of the epithelial base at the expense of adjacent principal cells. Distinguishing features were the nuclei with highly irregular shapes often lobulated with elongated lobes folding upon themselves and demonstrating thin connections. Deep furrows and clefts and large clumps of heterochromatin were prominent but not indicative of degeneration. The defining feature of the cytoplasm was the presence of one or many huge spherical and often irregularly shaped lysosomal elements containing lipidic inclusions. This suggested an active role in endocytosis of substances from the adjacent dilated intercellular spaces, which were at times filled with membranous profiles.They may be correspond to dendritic cells. The fact that each basally located cell type contacted the BM served to distinguish them from blood‐borne monocytic/F4/80‐positive macrophages. The latter were larger than the classic basal cells, but while demonstrating large lysosomal elements, they did not have irregular nuclear profiles nor contact the BM. In conclusion, our study defines several populations of basally located cells, including the classic basal cell, monocytic/F4/80‐positive macrophages and putative dendritic cells, each with their own distinctive features. (Supported by CIHR).

Published
2016
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8. ABCA17 mediates sterol efflux from mouse spermatozoa plasma membranes

Author

Morales, C. R., Ni, X., Smith, C. E., Nobuya Inagaki, and Hermo, L.

Subjects
endocrine system, urogenital system, 5 - Ciencias puras y naturales::57 - Biología [CDU], lipids (amino acids, peptides, and proteins), Cholesterol efflux, reproductive and urinary physiology, Mouse testis
Abstract

Mammalian spermatozoa lose plasma membrane cholesterol during maturation in the epididymis and during capacitation in the female reproductive tract. While cholesterol acceptors such as high-density lipoproteins (HDL) and apolipoproteins A-I (apoA-I) and J (Apo J) have been found in male and female reproductive tracts, transporters that mediate cholesterol efflux from plasma membranes of spermatozoa to acceptors are not well defined. Candidates include members of the ATP-binding cassette (ABC) transporter superfamily including ABCA1, ABCA7, ABCA17, and ABCG1. In this study, we utilize immunocytochemistry on sections of adult mouse testis and epididymis and RT-PCR on isolated germ cells. The data reveal that ABCA17 is expressed by steps 12-16 elongated spermatids in the mouse in testis and by spermatozoa in the lumen of the epididymis where ABCA17 localizes to the sperm head and tail midpiece. It also localizes on these areas of mouse sperm isolated from the epididymis. Moreover, ABCA17 antibody interferes with cholesterol efflux from spermatozoa to lipid acceptors apoA-I. Taken together, these results suggest that ABCA17 plays an important role in the process of sterol efflux which renders spermatozoa capable of fertilizing an oocyte.

Published
2012

12. Antimicrobial host defence peptide, LL-37, as a potential vaginal contraceptive

Author

Srakaew, N., primary, Young, C. D., additional, Sae-wu, A., additional, Xu, H., additional, Quesnel, K. L., additional, di Brisco, R., additional, Kongmanas, K., additional, Fongmoon, D., additional, Hommalai, G., additional, Weerachatyanukul, W., additional, Hall, S. H., additional, Zhang, Y.-L., additional, Panza, L., additional, Franchini, L., additional, Compostella, F., additional, Pearson, T. W., additional, Hancock, R. E., additional, Oko, R. J., additional, Hermo, L. S., additional, and Tanphaichitr, N., additional

Published
2014
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