CXCR4 Regulates Temporal Differentiation via PRC1 Complex in Organogenesis of Epithelial Glands.

CXC-chemokine receptor type 4 (CXCR4), a 7-transmembrane receptor family member, displays multifaceted roles, participating in immune cell migration, angiogenesis, and even adipocyte metabolism. However, the activity of such a ubiquitously expressed receptor in epithelial gland organogenesis has not yet been fully explored. To investigate the relationship between CXCL12/CXCR4 signaling and embryonic glandular organogenesis, we used an ex vivo culture system with live imaging and RNA sequencing to elucidate the transcriptome and protein-level signatures of AMD3100, a potent abrogating reagent of the CXCR4-CXCL12 axis, imprinted on the developing organs. Immunostaining results showed that CXCR4 was highly expressed in embryonic submandibular gland, lung, and pancreas, especially at the periphery of end buds containing numerous embryonic stem/progenitor cells. Despite no significant increase in apoptosis, AMD3100-treated epithelial organs showed a retarded growth with significantly slower branching and expansion. Further analyses with submandibular glands revealed that such responses resulted from the AMD3100-induced precocious differentiation of embryonic epithelial cells, losing mitotic activity. RNA sequencing analysis revealed that inhibition of CXCR4 significantly down-regulated polycomb repressive complex (PRC) components, known as regulators of DNA methylation. Treatment with PRC inhibitor recapitulated the AMD3100-induced precocious differentiation. Our results indicate that the epigenetic modulation by the PRC-CXCR12/CXCR4 signaling axis is crucial for the spatiotemporal regulation of proliferation and differentiation of embryonic epithelial cells during embryonic glandular organogenesis.

Studying centrosome function using three-dimensional cell cultures.

Three-dimensional (3D) cell cultures have long been recognized as a tool for the study of tissue architecture, polarity, and invasion. However, only recently these systems have been used to study centrosome and cilia functions. Studying these organelles in 3D cultures has elucidated new functions that otherwise would have been overlooked, demonstrating the value of these experimental systems to the field. Here we describe a culture method to study mammary epithelial cells in a 3D environment.

Ocorrência e morfologia de glândulas tegumentares no abdome de algumas abelhas (Hymenoptera: Apidae): um estudo comparado / Ocurrence and morphology of tegumentar glands in the abdomen of some bee species (Hymenoptera: Apidae): a comparative study

No presente trabalho foi estudada a ocorrência, distribuição e morfologia de glândulas tegumentares do abdome em Exomalopsis auropilosa Spinola, Centris fuscata Lepeletier, Epicharis flava Friese e Xylocopa (Neoxylocopa) suspecta Moure & Camargo. Os resultados mostraram a ocorrência de glândulas epiteliais (classe I) e unicelulares (classe III) com distribuição dorsal (tergais) e ventral (esternais) sem que se pudesse caracterizar um padrão relacionável com a posição filogenética ou grau de sociabilidade. No entanto, verificou-se uma tendência para maior número de glândulas em espécies com algum grau de sociabilidade como E. auropilosa e X. suspecta.

The present paper describes the presence, distribution and morphology of the abdominal tegumentar glands of Exomalopsis auropilosa Spinola, Centris fuscata Lepeletier, Epicharis flava Friese and Xylocopa (Neoxylocopa) suspecta Moure & Camargo. The studied bees have epithelial glands (class I) and unicellular glands (class III) distributed dorsally (tergal) and ventrally (esternal) without any pattern that could be correlated to the phylogenetic position. However, there is a tendency toward increased number of glands or more developed glands in the species with some degree of sociality as E. auropilosa and X. suspecta.