Inhibition of 5-alpha-reductase activity induces stromal remodeling and smooth muscle de-differentiation in adult gerbil ventral prostate

Prostatic differentiation during embryogenesis and its further homeostatic state maintenance during adult life depend on androgens. Dihydrotestosterone, which is synthesized from testosterone by 5 alpha-reductase (5 alpha-r), is the active molecule triggering androgen action within the prostate. In the present work, we examined the effects of 5 alpha-reductase inhibition by finasteride in the ventral prostate (VP) of the adult gerbil, employing histochemical and electron microscopy techniques to demonstrate the morphological and organizational changes of the organ. After 10 days of finasteride treatment at a dose of 100 mg/kg/day, the prostatic complex (VP and dorsolateral prostate) absolute weight was reduced to about 18%. The epithelial cells became short and cuboidal, with less secretory blebs and reduced acid phosphatase activity. The luminal sectional area diminished, suggestive of decreased secretory activity. The stromal/epithelial ratio increased, the stroma becoming thicker but less cellular. There was a striking accumulation of collagen fibrils, which was accompanied by an increase in deposits of amorphous granular material adjacent to the basal lamina and in the clefts between smooth muscle cells (SMC). Additionally, the periacinar smooth muscle became loosely packed. Some SMC were atrophic and showed a denser array of the cytoskeleton, whereas other SMC had a highly irregular outline with numerous spine-like projections. The present data indicate that 5 alpha-r inhibition causes epithelial and stromal changes by affecting intra-prostatic hormone levels. These alterations are probably the result of an imbalance of the homeostatic interaction between the epithelium and the underlying stroma.     

Castration-induced prostate epithelial cell apoptosis results from targeted oxidative stress attack of M1142-macrophages

Prostate development and function are regulated by androgens. Epithelial cell apoptosis in response to androgen deprivation is caspase-9-dependent and peaks at Day 3 after castration. However, isolated epithelial cells survive in the absence of androgens. Znf142 showed an on-off expression pattern in intraepithelial CD68-positive macrophages, with the on-phase at Day 3 after castration. Rats treated with gadolinium chloride to deplete macrophages showed a significant drop in apoptosis, suggesting a causal relationship between macrophages and epithelial cell apoptosis. Intraepithelial M1-polarization was also limited to Day 3, and the inducible nitric oxide synthase (iNOS) knockout mice showed significantly less apoptosis than wild-type controls. The epithelial cells showed focal DNA double-strand breaks (DSB), 8-oxoguanine, and protein tyrosine-nitrosylation, fingerprints of exposure to peroxinitrite. Cultured epithelial cells induced M1-polarization and showed focal DSB and underwent apoptosis. The same phenomena were reproduced in LNCaP cells cocultured with Raw 264.7 macrophages. In conclusion, the M1 ₁₄₂-macrophage (named after Znf142) attack causes activation of the intrinsic apoptosis pathway in epithelial cells after castration.     

Growth cartilage calcification and formation of bone trabeculae are late and dissociated events in the endochondral ossification of <Emphasis Type="Italic">Rana catesbeiana</Emphasis>

Endochondral ossification in the growth cartilage of long bones from the bullfrog Rana catesbeiana was examined. In stage-46 tadpoles and 1-year-old animals, the hypertrophic cartilage had a smooth contact with the bone marrow and the matrix showed no calcification or endochondral bone formation. In spite of showing no aspects of calcification, the chondrocytes exhibited alkaline phosphatase activity and some of them died by apoptosis. However, matrix calcification and endochondral ossification were observed in 2-year-old bullfrogs. Calcium deposits appeared as isolated or coalesced spherical structures in the extracellular matrix of hypertrophic cartilage. Bone trabeculae were restricted to the central area at the sites where the hypertrophic cartilage surface was exposed to the bone marrow. Cartilage matrix calcification and the formation of bone trabeculae were not dependent on each other. Osteoclasts were involved in calcified matrix resorption. These results demonstrate that the calcification of hypertrophic cartilage and the deposition of bone trabeculae are late events in R. catesbeiana and do not contribute to the development and growth of long bones in adults. These processes may play a role in reinforcing bony structures as the bullfrog gains weight in adulthood. In addition, the deposition of bone trabeculae is not dependent on cartilage matrix calcification.     

The conquest of fresh water by the palaemonid shrimps: an evolutionary history scripted in the osmoregulatory epithelia of the gills and antennal glands

Extant Palaemonidae occupy aquatic environments that have generated physiological diversity during their evolutionary history. We analyze ultrastructural traits in gills and antennal glands of palaemonid species from distinct osmotic niches, and employ phylogenetic comparative methods to ascertain whether transformations in their osmoregulatory epithelia have evolved in tandem, driven by salinity. Gill pillar cells exhibit apical evaginations whose surface density (S_v, μm² plasma membrane area/μm³ cytoplasmic volume) ranges from 6.3–7.1 in Palaemon, and 0.7–38.4 in Macrobrachium. In the septal cells, S_v varies from 8.9–10.0 in Palaemon, and 3.3–21.6 in Macrobrachium; mitochondrial volumes (V_mit) range from 43.3–46.8% in Palaemon and 34.9–53.4% in Macrobrachium. In the renal proximal tubule cells, apical microvilli S_v varies from 27.0–34.3 in Palaemon, and 38.3–47.8 in Macrobrachium; basal invagination S_v ranges from 18.7–20.0 in Palaemon and 30.8–40.8 in Macrobrachium. Septal cell S_v shows phylogenetic signal; evagination height/density, apical S_v, and V_mit vary independently of species relatedness. Salt transport capability by the gill and renal epithelia has increased during palaemonid evolution, reflecting amplified membrane availability for ion transporter insertion. These traits underpin the increased osmotic gradients maintained against the external media. Gill ultrastructure and osmotic gradient have evolved in tandem, driven by salinity at the genus level. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 673–688.     

The genus Nanopterodectes Mironov, 2009 (Acari, Proctophyllodidae), with descriptions of three new species from antbirds (Passeriformes: Thamnophilidae) in Brazil

Three new species of the recently discovered, and hitherto monotypic, feather mite genus Nanopterodectes Mironov, 2009 are described: N. acutirostris n. sp. from Stymphalornis acutirostris Bornschein, Reinert & Teixeira, N. mentalis n. sp. from Dysithamnus mentalis (Temminck), and N. leucopterus n. sp. from Pyriglena leucoptera (Vieillot). This feather mite genus is currently restricted to passerine birds of the Neotropical family Thamnophilidae in Brazil. A key to the known species of Nanopterodectes is presented for both sexes.