title: Mice spermatogonial stem cells transplantation induces macrophage migration into the seminiferous epithelium and lipid body formation: high-resolution light microscopy and ultrastructural studies.
abstract: Transplantation of spermatogonial stem cells (SSCs), the male germline stem cells, in experimental animal models has been successfully used to study mechanisms involved in SSC self-renewal and to restore fertility. However, there are still many challenges associated with understanding the recipient immune response for SSCs use in clinical therapies. Here, we have undertaken a detailed structural study of macrophages elicited by SSCs transplantation in mice using both high-resolution light microscopy (HRLM) and transmission electron microscopy (TEM). We demonstrate that SSCs transplantation elicits a rapid and potent recruitment of macrophages into the seminiferous epithelium (SE). Infiltrating macrophages were derived from differentiation of peritubular monocyte-like cells into typical activated macrophages, which actively migrate through the SE, accumulate in the tubule lumen, and direct phagocytosis of differentiating germ cells and spermatozoa. Quantitative TEM analyses revealed increased formation of lipid bodies (LBs), organelles recognized as intracellular platforms for synthesis of inflammatory mediators and key markers of macrophage activation, within both infiltrating macrophages and Sertoli cells. LBs significantly increased in number and size in parallel to the augmented macrophage migration during different times post-transplantation. Our findings suggest that LBs may be involved with immunomodulatory mechanisms regulating the seminiferous tubule niche after SSC transplantation.
authors: Laboratory of Cellular Biology, Department of Biology, Federal University of Juiz de Fora, UFJF, Juiz de Fora, MG, Brazil.
authors: Felipe F
authors: FF
authors: Dias
authors: Hélio
authors: H
authors: Chiarini-Garcia
authors: Gleydes G
authors: GG
authors: Parreira
authors: Rossana C N
authors: RC
authors: Melo
mesh_terms: D000818:Animals; D002452:Cell Count; D002454:Cell Differentiation; D002465:Cell Movement; D049109:Cell Proliferation; D016207:Cytokines / Q000096:biosynthesis; D008264:Macrophages / Q000166:cytology / Q000276:immunology / Q000648:ultrastructure; D008297:Male; D051379:Mice; D046529:Microscopy, Electron, Transmission / Q000379:methods*; D009000:Monocytes / Q000166:cytology / Q000276:immunology / Q000648:ultrastructure; D015388:Organelles / Q000276:immunology / Q000648:ultrastructure; D010587:Phagocytosis / Q000276:immunology; D012670:Seminiferous Epithelium / Q000276:immunology / Q000648:ultrastructure*; D012671:Seminiferous Tubules / Q000276:immunology / Q000648:ultrastructure*; D012708:Sertoli Cells / Q000276:immunology / Q000648:ultrastructure*; D013091:Spermatogenesis; D013093:Spermatogonia / Q000166:cytology / Q000276:immunology / Q000637:transplantation / Q000648:ultrastructure*; D033581:Stem Cell Transplantation / Q000379:methods*; D013234:Stem Cells / Q000166:cytology / Q000276:immunology*; D013997:Time Factors
chemical_list: D016207:Cytokines