Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
299 result(s) for "Prostate - ultrastructure"
Sort by:
Subcellular Localization of p44/WDR77 Determines Proliferation and Differentiation of Prostate Epithelial Cells
The molecular mechanism that controls the proliferation and differentiation of prostate epithelial cells is currently unknown. We previously identified a 44-kDa protein (p44/wdr77) as an androgen receptor-interacting protein that regulates a set of androgen receptor target genes in prostate epithelial cells and prostate cancer. In this study, we found that p44 localizes in the cytoplasm of prostate epithelial cells at the early stage of prostate development when cells are proliferating, and its nuclear translocation is associated with cellular and functional differentiation in adult prostate tissue. We further demonstrated that cytoplasmic p44 protein is essential for proliferation of prostate epithelial cells, whereas nuclear p44 is required for cell differentiation and prostate- specific protein secretion. These studies suggest a novel mechanism by which proliferation and differentiation of prostate epithelial cells are controlled by p44's location in the cell.
Structural and ultrastructural evidence for telocytes in prostate stroma
The prostate comprises a glandular epithelium embedded within a fibromuscular stroma. The stroma is a complex arrangement of cells and extracellular matrix (ECM) components in addition to growth factors, regulatory molecules, remodelling enzymes, blood vessels, nerves and immune cells. The principal sources of ECM components are fibroblasts and smooth muscle cells (SMC), which synthesize the structural and regulatory components of the ECM. Telocytes (TCs) were recently described as a novel stromal cell type that exhibited characteristic features. The aim of this study was to confirm the presence of TCs in prostate stromal tissue of gerbils, as the stromal compartment of this gland is a dynamic microenvironment. We used transmission electron microscopy (TEM), light microscopy and immunohistochemistry methods to provide morphological evidence for the presence of TCs. Cells that resembled TCs were observed in gerbil prostatic stroma. These cells had small cellular bodies with very thin and extremely long cellular processes. They were found primarily in the subepithelial area and also at the periphery of SMC layers. TCs also exhibited moniliform processes, caveolae and nuclei surrounded by small amounts of cytoplasm. Close contacts between TC podomers were evident, particularly in the adjacent epithelial compartment. This morphological evidence supported the presence of TCs in the gerbil prostatic stroma, which we report for the first time.
An analysis of benign human prostate offers insights into the mechanism of apocrine secretion and the origin of prostasomes
The structure and function of normal human prostate is still not fully understood. Herein, we concentrate on the different cell types present in normal prostate, describing some previously unreported types and provide evidence that prostasomes are primarily produced by apocrine secretion. Patients ( n  = 10) undergoing TURP were prospectively consented based on their having a low risk of harbouring CaP. Scanning electron microscopy and transmission electron microscopy was used to characterise cell types and modes of secretion. Zinc levels were determined using Inductively Coupled Plasma Mass Spectrometry. Although merocrine secretory cells were noted, the majority of secretory cells appear to be apocrine; for the first time, we clearly show high-resolution images of the stages of aposome secretion in human prostate. We also report a previously undescribed type of epithelial cell and the first ultrastructural image of wrapping cells in human prostate stroma. The zinc levels in the tissues examined were uniformly high and X-ray microanalysis detected zinc in merocrine cells but not in prostasomes. We conclude that a significant proportion of prostasomes, possibly the majority, are generated via apocrine secretion. This finding provides an explanation as to why so many large proteins, without a signal peptide sequence, are present in the prostatic fluid.
The Janus-faced nature of prostasomes: their pluripotency favours the normal reproductive process and malignant prostate growth
Prostasomes are submicron secretory granules synthesized, stored and secreted by the epithelial cells of the human prostate gland. They are membrane-surrounded also in their extracellular appearance and the membrane architecture is composite. They are believed to be life-giving and act as protectors of the spermatozoa in the lower and upper female genital tract on their way to the ovum. Hence, the prostasomes are immunosuppressive and inhibitory of complement activation. Further, they promote sperm's forward motility and have antioxidant and antibacterial capacities. The prostasomes with their many composite abilities seem to turn against the host cell after the age of 50 y being conducive to the transition of the normal prostate epithelial cell into a neoplastic cell and therewith lay the foundations of the very high prevalence of prostate cancer of men of more than 50 y of age.
What is the most effective local anesthesia for transrectal ultrasonography-guided biopsy of the prostate? A systematic review and network meta-analysis of 47 randomized clinical trials
We aimed to compare the effectiveness of various local anesthetic methods for controlling prostate biopsy (PBx) related pain using network meta-analysis. Literature searches were performed on PubMed/Medline, Embase, and Cochrane Library up to March 2018. Forty-seven randomized controlled trials, in which the effectiveness of PBx-related pain was investigated using a visual analogue scale after various local anesthetic methods, were included. The local anesthetic methods included intraprostatic local anesthesia (IPLA), intrarectal local anesthesia (IRLA), intravenous sedation (IVS), periprostatic nerve block (PNB), pelvic plexus block (PPB), and spinal anesthesia (SPA). Eight pairwise meta-analyses and network meta-analyses with 21 comparisons were performed. All modalities, except single use of IPLA and IRLA, were more effective than placebo. Our results demonstrate that PNB + IVS (rank 1) and SPA (rank 2) were the most effective methods for pain control. The followings are in order of PPB + IRLA, PNB + IPLA, PPB, PNB + IRLA, IVS, and PNB. In conclusion, the most effective way to alleviate PBx-related pain appears to be PNB + IVS and SPA. However, a potential increase in medical cost and additional risk of morbidities should be considered. In the current outpatient setting, PPB + IRLA, PNB + IPLA, PPB, PNB + IRLA, and PNB methods are potentially more acceptable options.
Differences in phenotype and gene expression of prostate stromal cells from patients of varying ages and their influence on tumour formation by prostate epithelial cells
Prostate cancer (PCa) is an age-related disease, and the stromal microenvironment plays an important role in prostatic malignant progression. However, the differences in prostate stromal cells present in young and old tissue are still obscure. We established primary cultured stromal cells from normal prostatic peripheral zone (PZ) of donors of varying ages and found that cultured stromal cells from old donors (PZ-old) were more enlarged and polygonal than those from young donors (PZ-young). Furthermore, based on immunocytochemical and ultrastructural analysis, the components of stromal cells changed from a majority of fibroblasts to a mixture of fibroblasts and myofibroblasts with increasing donor age. Using a three-dimensional in vitro culture system, we found that PZ-old stromal cells could enhance the proliferation, migration and invasion of cocultured benign BPH-1 and PC-3 cells. Using an in vivo tissue recombination system, we also found that PZ-old stromal cells are more effective than PZ-young cells in promoting tumour formation by BPH-1 cells of high passage(〉100) and PC-3 cells. To probe the possible mechanism of these effects, we performed cDNA microarray analysis and profiled 509 upregulated genes and 188 downregulated genes in PZ-old cells. Among the changed genes, we found genes coding for a subset of paracrine factors that are capable of influencing adjacent epithelial cells; these include hepatocyte growth factor (HGF), fibroblast growth factor 5 (FGF5), insulin-like growth factor 2 (IGF2), insulin-like growth factor-binding protein 4 (IGFBP4), IGFBP5 and matrix metallopeptidase 1 (MMP1). Changes in the expression of these genes were further confirmed by quantitative real-time polymerase chain reaction (PCR), Western blotting and enzyme-linked immunosorbent assays. Overall, our findings indicate that stromal cells from prostate PZ of old donors are more active than similar cells from young donors in promoting the malignant process of adjacent epithelial cells. This finding hints at a new potential strategy for the prevention of PCa.
Expression of NDRG1, a differentiation-related gene, in human tissues
NDRG1 is a member of the new N-myc downregulated gene (NDRG) family which belongs to the alpha/beta hydrolase superfamily, but without presenting a hydrolytic catalytic site. Diverse physiological and pathological conditions (hypoxia, cellular differentiation, heavy metal, N-myc, neoplasia) modulate NDRG1 transcription, mRNA stability, and translation. In this report we present the immunohistochemical localization of NDRG1 in a large set of normal human tissues at light and electron microscopic levels. The immunoreactivity of NDRG1 is mostly found in epithelial cells with different aspects. We observed NDRG1 primarily in the cytoplasm, but it is also associated with the cellular membrane and adherens junctions. Given the strong upregulation of NDRG1 under hypoxia and its nuclear localization, we propose a role for NDRG1 in protection from ischemic cell damage. The multiple localizations of this protein also suggest pleiotropic functions amongst which a functional involvement in the E-cadherin/catenin complex.
Proteomic Profiling of Exosomes Leads to the Identification of Novel Biomarkers for Prostate Cancer
Current markers for prostate cancer, such as PSA lack specificity. Therefore, novel biomarkers are needed. Unfortunately, the complexity of body fluids often hampers biomarker discovery. An attractive alternative approach is the isolation of small vesicles, i.e. exosomes, ∼100 nm, which contain proteins that are specific to the tissue from which they are derived and therefore can be considered as treasure chests for disease-specific biomarker discovery. Exosomes were isolated from 2 immortalized primary prostate epithelial cells (PNT2C2 and RWPE-1) and 2 PCa cell lines (PC346C and VCaP) by ultracentrifugation. After tryptic digestion, proteomic analyses utilized a nanoLC coupled with an LTQ-Orbitrap operated in tandem MS (MS/MS) mode. Accurate Mass and Time (AMT) tag approach was employed for peptide identification and quantitation. Candidate biomarkers were validated by Western blotting and Immunohistochemistry. Proteomic characterization resulted in the identification of 248, 233, 169, and 216 proteins by at least 2 peptides in exosomes from PNT2C2, RWPE-1, PC346C, and VCaP, respectively. Statistical analyses revealed 52 proteins differently abundant between PCa and control cells, 9 of which were more abundant in PCa. Validation by Western blotting confirmed a higher abundance of FASN, XPO1 and PDCD6IP (ALIX) in PCa exosomes. Identification of exosomal proteins using high performance LC-FTMS resulted in the discovery of PDCD6IP, FASN, XPO1 and ENO1 as new candidate biomarkers for prostate cancer.
The Roles of Tight Junctions and Claudin-1 in the Microbubble-Mediated Ultrasound-Induced Enhancement of Drug Concentrations in Rat Prostate
Although microbubble-mediated ultrasound irradiation can enhance the prostate permeability, little is known about the mechanism. In our study, the healthy, adult male SD rats were divided into four groups: the BC, US, MB, and MMUS groups. A therapeutic ultrasound apparatus was used to treat the rats prostates in the presence of circulating MBs. Cefuroxime was injected to assess prostate permeability by HPLC. The structures of prostate tissues and TJs were observed by light and transmission electron microscopy. Western blot was used to assess claudin-1 expression. After treatment of microbubble-mediated ultrasound irradiation, the cefuroxime concentrations in the prostate were significantly increased. HE staining demonstrated that the gland epithelial cell layer became dropsical, thick, and disordered. In transmission electron microscopy, the TJs between adjacent capillary endothelial cells or gland epithelial cells were disjointed and partly interrupted. Furthermore, western blot showed the expression of claudin-1 was significantly decreased. However, these findings were not observed in the prostates exposed to microbubble or ultrasound alone, as well as the healthy control rats. In conclusion, microbubble-mediated ultrasound irradiation significantly enhanced the prostate permeability and improve the cefuroxime concentrations in prostate. The changes in TJs structure and the decreased claudin-1 expression may play important roles in this process.
A paclitaxel-loaded recombinant polypeptide nanoparticle outperforms Abraxane in multiple murine cancer models
Packaging clinically relevant hydrophobic drugs into a self-assembled nanoparticle can improve their aqueous solubility, plasma half-life, tumour-specific uptake and therapeutic potential. To this end, here we conjugated paclitaxel (PTX) to recombinant chimeric polypeptides (CPs) that spontaneously self-assemble into ∼60 nm near-monodisperse nanoparticles that increased the systemic exposure of PTX by sevenfold compared with free drug and twofold compared with the Food and Drug Administration-approved taxane nanoformulation (Abraxane). The tumour uptake of the CP–PTX nanoparticle was fivefold greater than free drug and twofold greater than Abraxane. In a murine cancer model of human triple-negative breast cancer and prostate cancer, CP–PTX induced near-complete tumour regression after a single dose in both tumour models, whereas at the same dose, no mice treated with Abraxane survived for >80 days (breast) and 60 days (prostate), respectively. These results show that a molecularly engineered nanoparticle with precisely engineered design features outperforms Abraxane, the current gold standard for PTX delivery. The encapsulation of a drug into nanoparticles can be a useful way control and improve its efficacy. Here, the authors conjugate paclitaxel to recombinant chimeric polypeptides that self-assemble into therapeutic nanoparticles that outperform Abraxane in murine tumour models.