Proc Natl Acad Sci U S A
February 2021
Seminal fluid plays an essential role in promoting male reproductive success and modulating female physiology and behavior. In the fruit fly, , Sex Peptide (SP) is the best-characterized protein mediator of these effects. It is secreted from the paired male accessory glands (AGs), which, like the mammalian prostate and seminal vesicles, generate most of the seminal fluid contents.
View Article and Find Full Text PDFOxytocinergic neurons in the paraventricular nucleus of the hypothalamus that project to extrahypothalamic brain areas and the lumbar spinal cord play an important role in the control of erectile function and male sexual behavior in mammals. The gastrin-releasing peptide (GRP) system in the lumbosacral spinal cord is an important component of the neural circuits that control penile reflexes in rats, circuits that are commonly referred to as the "spinal ejaculation generator (SEG)." We have examined the functional interaction between the SEG neurons and the hypothalamo-spinal oxytocin system in rats.
View Article and Find Full Text PDFArginine vasopressin (AVP) is synthesized in parvocellular- and magnocellular neuroendocrine neurons in the paraventricular nucleus (PVN) of the hypothalamus. Whereas magnocellular AVP neurons project primarily to the posterior pituitary, parvocellular AVP neurons project to the median eminence (ME) and to extrahypothalamic areas. The AVP gene encodes pre-pro-AVP that comprises the signal peptide, AVP, neurophysin (NPII), and a copeptin glycopeptide.
View Article and Find Full Text PDFExosomes are secreted extracellular vesicles carrying diverse molecular cargos, which can modulate recipient cell behaviour. They are thought to derive from intraluminal vesicles formed in late endosomal multivesicular bodies (MVBs). An alternate exosome formation mechanism, which is conserved from fly to human, is described here, with exosomes carrying unique cargos, including the GTPase Rab11, generated in Rab11-positive recycling endosomal MVBs.
View Article and Find Full Text PDFThe superior vena cava is formed during the fetal period by the development of anastomoses between the right and left anterior cardinal veins, and the regression of the central part of the left anterior cardinal vein. The persistence of this part of the left anterior cardinal vein causes the formation of a left superior vena cava, which is a rare anomaly in cadaver dissection. We report the case of a persistent left superior vena cava with a normal right superior vena cava in a 95-year-old male cadaver, which was discovered during anatomical dissection for medical students at Kawasaki Medical School in 2016.
View Article and Find Full Text PDFInsulin/insulin-like growth factor signalling (IIS), acting primarily through the PI3-kinase (PI3K)/AKT kinase signalling cassette, plays key evolutionarily conserved regulatory roles in nutrient homeostasis, growth, ageing and longevity. The dysfunction of this pathway has been linked to several age-related human diseases including cancer, Type 2 diabetes and neurodegenerative disorders. However, it remains unclear whether minor defects in IIS can independently induce the age-dependent functional decline in cells that accompany some of these diseases or whether IIS alters the sensitivity to other aberrant signalling.
View Article and Find Full Text PDFArginine vasopressin (AVP) is a neurohypophysial hormone synthesized as a part of a prepropeptide precursor containing the signal peptide, AVP hormone, AVP-associated neurophysin II and copeptin in the hypothalamic neurosecretory neurons. A transgenic (Tg) rat line expressing the AVP-eGFP fusion gene has been generated. To establish the AVP-eGFP Tg rat as a unique model for an analysis of AVP dynamics in vivo, we first examined the in vivo molecular dynamics of the AVP-eGFP fusion gene, and then the release of GFP in response to physiological stimuli.
View Article and Find Full Text PDFMale reproductive glands secrete signals into seminal fluid to facilitate reproductive success. In Drosophila melanogaster, these signals are generated by a variety of seminal peptides, many produced by the accessory glands (AGs). One epithelial cell type in the adult male AGs, the secondary cell (SC), grows selectively in response to bone morphogenetic protein (BMP) signaling.
View Article and Find Full Text PDFUptake of ingested microparticles into small intestinal tissues and on to secondary organs has moved from being an anecdotal phenomenon to a recognised and quantifiable process, which is relevant to risk assessment of accidental exposure, treatment of multi-organ dysfunction syndrome and therapeutic uses of encapsulated drug or vaccine delivery. This review puts in context with the literature the findings of a morphological study of microparticle uptake, using two approaches. The first is a rat in vivo in situ model, appropriate to a study rooted in the exposure of human populations to microparticles.
View Article and Find Full Text PDFCaco-2 cells form an enterocyte-like monolayer that has been used to explore small intestinal microparticle uptake. They are a useful functional model for the investigation of in vivo drug delivery systems and the uptake of particulate environmental pollutants. The aim of this paper was to determine if the previously reported decrease in Caco-2 transepithelial resistance following exposure to macrophages was matched by increased microparticle uptake, especially as macrophage phagocytosis simulates removal of particles from the subepithelial compartment.
View Article and Find Full Text PDFPurpose: To determine the interaction between X-irradiation and in vitro intestinal microparticle uptake through Caco-2 epithelial cells.
Methods: Caco-2 cells were cultured on 3 microm porous membranes for 21 days, X-irradiated with 2 Gy or sham-irradiated, then incubated for 5 or 30 min and exposed apically for 30 min to 2 microm latex microparticles. Measurements included cell dimensions, from confocal microscope 'optical slices'; transepithelial resistance (TER) for tight junction (TJ) permeability; particle aggregation; and particle numbers on (adsorbed), in (intraepithelial) and through (submembranous) the epithelium.
The regulatory actions of estrogens on magnocellular oxytocin (OT) neurons of the paraventricular and supraoptic nuclei are well documented. Although the expression and distribution of nuclear estrogen receptor-beta, but not estrogen receptor-alpha, in the OT neuron has been described, the nuclear receptors may not explain all aspects of estrogen function in the hypothalamic OT neuron. Recently a G protein-coupled receptor (GPR) for estrogens, GPR30, has been identified as a membrane-localized estrogen receptor in several cancer cell lines.
View Article and Find Full Text PDFAnnexin 1 (ANXA1) is a Ca2+- and phospholipid-binding protein that plays an important role as a mediator of glucocorticoid action in the host-defence and neuroendocrine systems. Sex differences in hypothalamo-pituitary-adrenal (HPA) axis activity are well documented and a number of studies have demonstrated that gonadal steroids act as regulators of HPA activity. The aim of this study was to investigate the effect of ovariectomy and 17beta-estradiol replacement, and estrous cycle stage, on anterior pituitary ANXA1 content.
View Article and Find Full Text PDFAnnexin 1 (ANXA1) is a member of the annexin family of phospholipid- and calcium-binding proteins with a well demonstrated role in early delayed (30 min to 3 h) inhibitory feedback of glucocorticoids in the hypothalamus and pituitary gland. This study used adrenal gland tissue from ANXA1-null transgenic mice, in which a beta-galactosidase (beta-Gal) reporter gene was controlled by the ANXA1 promoter, and wild-type control mice to explore the potential role of ANXA1 in adrenal function. RT-PCR and Western blotting revealed strong expression of ANXA1 mRNA and protein in the adrenal gland.
View Article and Find Full Text PDFIn this study, epididymal adipose tissue from male annexin 1 (ANXA1)-null and wild-type control mice were used to explore the potential role of ANXA1 in adipocyte biology. ANXA1 was detected by Western blot analysis in wild-type tissue and localized predominantly to the stromal-vascular compartment. Epididymal fat pad mass was reduced by ANXA1 gene deletion, but adipocyte size was unchanged, suggesting that ANXA1 is required for the maintenance of adipocyte and/or preadipocyte cell number.
View Article and Find Full Text PDFAnnexin 1 (ANXA1), a 37-kDa protein, is a member of the superfamily of Ca(2+)- and phospholipid-binding annexin proteins. In the anterior pituitary, ANXA1 is expressed mainly by folliculostellate (FS) cells and mediates the early delayed feedback inhibition exerted by glucocorticoids on the release of ACTH and other pituitary hormones. It has been previously demonstrated that TtT/GF cells (a FS cell line) express and externalize ANXA1 in response to glucocorticoid treatment.
View Article and Find Full Text PDFFemale infertility is a worldwide problem affecting 10-15% of the population. The cause of the infertility in many cases is not known. In the present report, we demonstrate that alterations in two transmembrane structural proteins, IA-2 and IA-2beta, located in dense core secretory vesicles (DCV) of many endocrine and neuroendocrine cells, can result in female infertility.
View Article and Find Full Text PDFAnnexin 1 (ANXA1) was first identified as a mediator of the anti-inflammatory actions of glucocorticoids in the host defence system. Subsequent work revealed that this protein fulfils a wider brief and it is now recognized as an important signalling intermediate in a variety of other systems. Here, we consider the role of ANXA1 in the endocrine system, placing particular emphasis on new insights into the mechanisms and functional significance of the secondary processing of ANXA1, the processes that control the intracellular and transmembrane trafficking of the molecule and the molecular mechanisms of ANXA1 action that have identified a novel role for the protein as a paracrine/juxtacrine mediator of the non-genomic actions of glucocorticoids in the neuroendocrine system.
View Article and Find Full Text PDFObjective: Annexin 1 (ANXA1), a 37-kDa protein, plays an important role as a mediator of glucocorticoid action in the anterior pituitary gland and has been implicated in the processes of tumorigenesis in a number of other tissues. As a prelude to examining the potential role of ANXA1 in the pathophysiology of pituitary tumours, this study examined the expression, phosphorylation status and distribution of ANXA1 and the closely related protein, annexin 5 (ANXA5), in a series of pituitary adenomas and in two carcinomas.
Patients And Design: Forty-two human pituitary adenomas were examined.
Our recent studies on rat pituitary tissue suggest that the annexin 1 (ANXA1)-dependent inhibitory actions of glucocorticoids on ACTH secretion are effected via a paracrine mechanism that involves protein kinase C (PKC)-dependent translocation of a serine-phosphorylated species of ANXA1 (Ser-P-ANXA1) to the plasma membrane of the nonsecretory folliculostellate cells. In the present study, we have used a human folliculostellate cell line (PDFS) to explore the signaling mechanisms that cause the translocation of Ser-P-ANXA1 to the membrane together with Western blot analysis and flow cytometry to detect the phosphorylated protein. Exposure of PDFS cells to dexamethasone caused time-dependent increases in the expression of ANXA1 mRNA and protein, which were first detected within 2 h of steroid contact.
View Article and Find Full Text PDFAnnexin 1 (ANXA1) has a well-demonstrated role in early delayed inhibitory feedback of glucocorticoids in the pituitary. ANXA1 is located in folliculo-stellate (FS) cells, and glucocorticoids act on these cells to externalize and stimulate the synthesis of ANXA1. However, ANXA1 lacks a signal sequence so the mechanism by which ANXA1 is externalized from FS cells was unknown and has been investigated.
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