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Context: Declining fertility is an issue in multiple mammalian species. As the site of fertilisation and early embryo development, the oviduct plays a critical role in embryo survival, yet there is a paucity of information on how the oviduct regulates this process. Aims: We hypothesised that differences in steroid hormone signalling and/or immune function would be observed in a model of poor embryo survival, the peripubertal ewe. Methods: We examined expression of steroid hormones in systemic circulation, oviductal expression of oestrogen receptor α and genes important in steroid hormone signalling, and immune function in pregnant and cyclic peripubertal and adult ewes on day 3 after oestrus. Key results: Concentrations of progesterone, but not oestradiol, were decreased in the peripubertal ewe compared to the adult ewe. Oestrogen receptor α protein expression was increased in the peripubertal ewe, but pathway analysis of gene expression revealed downregulation of the oestrogen signalling pathway compared to the adult ewe. Differential expression of several genes involved in immune function between the peripubertal and adult ewe was consistent with an unfavourable oviductal environment in the peripubertal ewe lamb. Oestradiol concentration was positively correlated with the expression of multiple genes involved in the regulation of immune function. Conclusions: Differences in the immune environment of the oviduct, potentially linked to differential modulation by steroid hormones, may partially underly the poor fertilisation and early embryo survival observed in the peripubertal ewe. Implications: A unfavourable oviductal environment may play an important role in limiting reproductive success. Declining fertility is an issue in multiple mammalian species, with around 15% of couples experiencing infertility. Differential expression of genes involved in inflammation, linked with altered steroid signalling in the oviduct, was observed in peripubertal ewes, a model of poor fertility. Ensuring that the oviductal environment does not become hostile to fertilisation and early embryo development may provide a novel approach to improve fertility, particularly in conditions associated with chronic low-grade inflammation. Photograph by Jenny Juengel. [ABSTRACT FROM AUTHOR]

Simple Summary: Prostate cancer is one of the leading causes of death in men. Current methods for grading and determining treatment options are not as accurate as they need to be with some men either undergoing unnecessary, life-changing treatment or not being treated and developing late-stage disease. We assessed the effect of proteins called activins on the growth of prostate cell lines and examined their expression in prostate cancer biopsy samples from patients with different grades of tumor. Activin B and activin C were shown to have increased and decreased expression, respectively, in higher grade prostate cancer and to have opposing effects on prostate cell growth and migration. Therefore, these proteins are potential markers for distinguishing aggressive from indolent prostate cancer and may also provide novel targets for prostate cancer treatment. Current prognostic and diagnostic tests for prostate cancer are not able to accurately distinguish between aggressive and latent cancer. Members of the transforming growth factor-β (TGFB) family are known to be important in regulating prostate cell growth and some have been shown to be dysregulated in prostate cancer. Therefore, the aims of this study were to examine expression of TGFB family members in primary prostate tumour tissue and the phenotypic effect of activins on prostate cell growth. Tissue cores of prostate adenocarcinoma and normal prostate were immuno-stained and protein expression was compared between samples with different Gleason grades. The effect of exogenous treatment with, or overexpression of, activins on prostate cell line growth and migration was examined. Activin B expression was increased in cores containing higher Gleason patterns and overexpression of activin B inhibited growth of PNT1A cells but increased growth and migration of the metastatic PC3 cells compared to empty vector controls. In contrast, activin C expression decreased in higher Gleason grades and overexpression increased growth of PNT1A cells and decreased growth of PC3 cells. In conclusion, increased activin B and decreased activin C expression is associated with increasing prostate tumor grade and therefore have potential as prognostic markers of aggressive prostate cancer. [ABSTRACT FROM AUTHOR]

Intraocular pressure (IOP) is regulated by the resistance to outflow of the eye's aqueous humor. Elevated resistance raises IOP and can cause glaucoma. Despite the importance of outflow resistance, its site and regulation are unclear. The small size, complex geometry, and relative inaccessibility of the outflow pathway have limited study to whole animal, whole eye, or anterior-segment preparations, or isolated cells. We now report measuring elemental contents of the heterogeneous cell types within the intact human trabecular outflow pathway using electron-probe X-ray microanalysis. Baseline contents of [Na.sup.+], [K.sup.+], [Cl.sup.-], and P and volume (monitored as Na+K contents) were comparable to those of epithelial cells previously studied. Elemental contents and volume were altered by ouabain to block [Na.sup.+]-[K.sup.+]-activated ATPase and by hypotonicity to trigger a regulatory volume decrease (RVD). Previous results with isolated trabecular meshwork (TM) cells had disagreed whether TM cells express an RVD. In the intact tissue, we found that all cells, including TM cells, displayed a regulatory solute release consistent with an RVD. Selective agonists of AI and A2 adenosine receptors (ARs), which exert opposite effects on lOP, produced similar effects on juxtacanalicular (JCT) cells, previously inaccessible to functional study, but not on Schlemm's canal cells that adjoin the JCT. The results obtained with hypotonicity and AR agonists indicate the potential of this approach to dissect physiological mechanisms in an area that is extremely difficult to study functionally and demonstrate the utility of electron microprobe analysis in studying the cellular physiology of the human trabecular outflow pathway in situ. regulatory volume decrease; adenosine receptor agonists; Schlemm's canal cells; juxtacanalicular cells; trabecular meshwork cells

The rate of aqueous humor formation sequentially across the pigmented (PE) and nonpigmented (NPE) ciliary epithelial cell layers may not be uniform over the epithelial surface. Because of the tissue's small size and complex geometry, this possibility cannot be readily tested by conventional techniques. Rabbit iris-ciliary bodies were divided, incubated, quick-frozen, cryosectioned, and freeze-dried for electron probe X-ray microanalysis of the elemental contents of the PE and NPE cells. We confirmed that preincubation with ouabain to block [Na.sup.+], [K.sup.+]-ATPase increases [Na.sup.+] and decreases [K.sup.+] contents far more anteriorly than posteriorly. The anterior and posterior regions were the iridial portion of the primary ciliary processes and the pars plicata, respectively. Following interruption of gap junctions with heptanol, ouabain produced smaller changes in anterior PE cells, possibly reflecting higher [Na.sup.+] or [K.sup.+] permeability of anterior NPE cells. Inhibiting [Na.sup.+] entry selectively with amiloride, benzamil, or dimethylamiloride reduced anterior effects of ouabain by ~50%. Regional dependence of net secretion was also assessed with hypotonic stress, which stimulates ciliary epithelial cell regulatory volume decrease (RVD) and net [Cl.sup.-] secretion. In contrast to ouabain's actions, the RVD was far more marked posteriorly than anteriorly. These results suggest that 1) enhanced [Na.sup.+] reabsorption anteriorly, likely through [Na.sup.+] channels and [Na.sup.+]/[H.sup.+] exchange, mediates the regional dependence of ouabain's actions; and 2) secretion may proceed primarily posteriorly, with secondary processing and reabsorption anteriorly. Stimulation of anterior reabsorption might provide a novel strategy for reducing net secretion. aqueous humor; rabbit iris-ciliary body; net secretion; sodium channels; sodium/hydrogen ion exchange

Electron microprobe analysis of ouabain-exposed ciliary epithelium: PE-NPE cell couplets form the functional units. Am J Physiol Cell Physiol 286: C1376--C1389, 2004. First published February 4, 2004; 10.1152/ajpcell. 00248.2003.--Aqueous humor is secreted by the bilayered ciliary epithelium. Solutes and water enter the pigmented ciliary epithelial (PE) cell layer, cross gap junctions into the nonpigmented ciliary epithelial (NPE) cell layer, and are released into the aqueous humor. Electrical measurements suggest that beptanol reduces transepithelial ion movement by interrupting PE-NPE communication and that gap junctions may be a regulatory site of aqueous humor formation. Several lines of evidence also suggest that net ciliary epithelial transport is strongly region dependent. Divided rabbit iris-ciliary bodies were incubated in chambers under control and experimental conditions, quick-frozen, cryosectioned, and freeze-dried. Elemental intracellular contents of NPE and PE cells were determined by electron probe X-ray microanalysis. With or without heptanol, ouabain produced concentration--and time-dependent changes more markedly in anterior than in posterior epithelium. Without heptanol, there were considerable cell-to-cell variations in Na gain and K loss. However, contiguous NPE and PE cells displayed similar changes, even when nearby cell pairs were little changed by ouabain in aqueous, stromal, or both reservoirs. In contrast, with heptanol present, ouabain added to aqueous or both reservoirs produced much larger changes in NPE than in PE cells. The results indicate that 1) heptanol indeed interrupts PE-NPE junctions, providing an opportunity for electron microprobe analysis of the sidedness of modification of ciliary epithelial secretion; 2) Na and K undergo faster turnover in anterior than in posterior epithelium; and 3) PE-NPE gap junctions differ from PE-PE and NPE-NPE junctions in permitting ionic equilibration between adjoining ouabain-stressed cells. pigmented ciliary epithelial cells; nonpigmented ciliary epithelial cells; gap junctions; aqueous humor; [Na.sup.+]/[K.sup.+] exchange pump; rabbit iris-ciliary body

Activins and inhibins, members of the TGF-β superfamily, are growth and differentiation factors involved in the regulation of several biological processes, including reproduction, development, and fertility. Previous studies have shown that the activin-β A subunit plays a pivotal role in prostate development. Activin-A inhibits branching morphogenesis in the developing prostate, and its expression is associated with increased apoptosis in the adult prostate. Follistatin, a structurally unrelated protein to activins, is an antagonist of activin-A. A balance between endogenous activin-A and follistatin is required to maintain prostatic branching morphogenesis. Deregulation of this balance leads to branching inhibition or excessive branching and increased maturation of the stroma surrounding the differentiating epithelial ducts. Recent work identified another member of the TGF-β superfamily, the activin-β C subunit, as a novel antagonist of activin-A. Over-expression of activin-C (β C -β C ) alters prostate homeostasis, by interfering with the activin-A signaling. The current study characterized the spatiotemporal localization of activin-A, activin-C and follistatin in the adult and developing mouse prostate using immunohistochemical analysis. Results showed activin-C and follistatin are differentially expressed during prostate development and suggested that the antagonistic property of follistatin is secondary to the action of activin-C. In conclusion, the present study provides evidence to support a role of activin-C in prostate development and provides new insights in the spatiotemporal localization of activins and their antagonists during mouse prostate development. [ABSTRACT FROM AUTHOR]