During spermatogenesis, developing germ cells that lack the cellular ultrastructures of filopodia and lamellipodia generally found in migrating cells, such as macrophages and fibroblasts, rely on Sertoli cells to support their transport across the seminiferous epithelium. These include the transport of preleptotene spermatocytes across the blood-testis barrier (BTB), but also the transport of germ cells, in particular developing haploid spermatids, across the seminiferous epithelium, that is to and away from the tubule lumen, depending on the stages of the epithelial cycle. On the other hand, cell junctions at the Sertoli cell-cell and Sertoli-germ cell interface also undergo rapid remodeling, involving disassembly and reassembly of cell junctions, which, in turn, are supported by actin- and microtubule-based cytoskeletal remodeling. Interestingly, the underlying mechanism(s) and the involving biomolecule(s) that regulate or support cytoskeletal remodeling remain largely unknown. Herein, we used an in vitro model of primary Sertoli cell cultures that mimicked the Sertoli BTB in vivo overexpressed with the ribosomal protein S6 (rpS6, the downstream signaling protein of mammalian target of rapamycin complex 1 [mTORC1]) cloned into the mammalian expression vector pCI-neo, namely, quadruple phosphomimetic and constitutively active mutant of rpS6 (pCI-neo/p-rpS6-MT) versus pCI-neo/rpS6-WT (wild-type) and empty vector (pCI-neo/Ctrl) for studies. These findings provide compelling evidence that the mTORC1/rpS6 signal pathway exerted its effects to promote Sertoli cell BTB remodeling. This was mediated through changes in the organization of actin- and microtubule-based cytoskeletons, involving changes in the distribution and/or spatial expression of actin- and microtubule-regulatory proteins.
Actins/metabolism* ; Animals ; Blood-Testis Barrier/metabolism* ; Cells, Cultured ; Male ; Mechanistic Target of Rapamycin Complex 1/metabolism* ; Permeability ; Rats ; Ribosomal Protein S6/metabolism* ; Seminiferous Epithelium/metabolism* ; Sertoli Cells/metabolism* ; Signal Transduction/physiology*

The present study was designed to analyze the metabolites of all-trans-retinal (atRal) and compare the cytotoxicity of atRal versus its derivative all-trans-retinoic acid (atRA) in human retinal pigment epithelial (RPE) cells. We confirmed that atRA was produced in normal pig neural retina and RPE. The amount of all-trans-retinol (atROL) converted from atRal was about 2.7 times that of atRal-derived atRA after incubating RPE cells with 10 μmol/L atRal for 24 h, whereas atRA in medium supernatant is more plentiful (91 vs. 29 pmol/mL), suggesting that atRA conversion facilitates elimination of excess atRal in the retina. Moreover, we found that mRNA expression of retinoic acid-specific hydroxylase CYP26b1 was dose-dependently up-regulated by atRal exposure in RPE cells, indicating that atRA inactivation may be also initiated in atRal-accumulated RPE cells. Our data show that atRA-caused viability inhibition was evidently reduced compared with the equal concentration of its precursor atRal. Excess accumulation of atRal provoked intracellular reactive oxygen species (ROS) overproduction, heme oxygenase-1 (HO-1) expression, and increased cleaved poly(ADP-ribose) polymerase 1 (PARP1) expression in RPE cells. In contrast, comparable dosage of atRA-induced oxidative stress was much weaker, and it could not activate apoptosis in RPE cells. These results suggest that atRA generation is an antidotal metabolism pathway for atRal in the retina. Moreover, we found that in the eyes of ABCA4^-/-RDH8^-/- mice, a mouse model with atRal accumulation in the retina, the atRA content was almost the same as that in the wild type. It is possible that atRal accumulation simultaneously and equally promotes atRA synthesis and clearance in eyes of ABCA4^-/-RDH8^-/- mice, thus inhibiting the further increase of atRA in the retina. Our present study provides further insights into atRal clearance in the retina.
ATP-Binding Cassette Transporters/physiology* ; Alcohol Oxidoreductases/physiology* ; Animals ; Cell Survival/drug effects* ; Cells, Cultured ; Humans ; Inactivation, Metabolic ; Mice ; Retina/metabolism* ; Retinal Pigment Epithelium/metabolism* ; Swine ; Tretinoin/pharmacology*

Mesothelial cells (MCs) cover the surface of visceral organs and the parietal walls of cavities, and they synthesize lubricating fluids to create a slippery surface that facilitates movement between organs without friction. Recent studies have indicated that MCs play active roles in liver development, fibrosis, and regeneration. During liver development, the mesoderm produces MCs that form a single epithelial layer of the mesothelium. MCs exhibit an intermediate phenotype between epithelial cells and mesenchymal cells. Lineage tracing studies have indicated that during liver development, MCs act as mesenchymal progenitor cells that produce hepatic stellate cells, fibroblasts around blood vessels, and smooth muscle cells. Upon liver injury, MCs migrate inward from the liver surface and produce hepatic stellate cells or myofibroblast depending on the etiology, suggesting that MCs are the source of myofibroblasts in capsular fibrosis. Similar to the activation of hepatic stellate cells, transforming growth factor β induces the conversion of MCs into myofibroblasts. Further elucidation of the biological and molecular changes involved in MC activation and fibrogenesis will contribute to the development of novel approaches for the prevention and therapy of liver fibrosis.
Epithelial Cells/*physiology ; Epithelium/metabolism ; Hepatic Stellate Cells/*physiology ; Humans ; Liver/*cytology/injuries/*physiology ; Liver Cirrhosis/etiology/prevention & control ; Liver Regeneration/*physiology ; Mesenchymal Stromal Cells/physiology ; Myofibroblasts/physiology

OBJECTIVETo focus on the asthmatic pathogenesis and clinical manifestations related to epithelial sodium channel (ENaC)/chlorine ion channel.

DATA SOURCESThe data analyzed in this review were the English articles from 1980 to 2015 from journal databases, primarily PubMed and Google Scholar. The terms used in the literature search were: (1) ENaCs; cystic fibrosis (CF) transmembrane conductance regulator (CFTR); asthma/asthmatic, (2) ENaC/sodium salt; CF; asthma/asthmatic, (3) CFTR/chlorine ion channels; asthma/asthmatic, (4) ENaC/sodium channel/scnn1a/scnn1b/scnn1g/scnn1d/amiloride-sensitive/amiloride-inhibtable sodium channels/sodium salt; asthma/asthmatic, lung/pulmonary/respiratory/tracheal/alveolar, and (5) CFTR; CF; asthma/asthmatic (ti).

STUDY SELECTIONThese studies included randomized controlled trials or studies covering asthma pathogenesis and clinical manifestations related to ENaC/chlorine ion channels within the last 25 years (from 1990 to 2015). The data involving chronic obstructive pulmonary disease and CF obtained from individual studies were also reviewed by the authors.

RESULTSAirway surface liquid dehydration can cause airway inflammation and obstruction. ENaC and CFTR are closely related to the airway mucociliary clearance. Ion transporters may play a critical role in pathogenesis of asthmatic exacerbations.

CONCLUSIONSIon channels have been the center of many studies aiming to understand asthmatic pathophysiological mechanisms or to identify therapeutic targets for better control of the disease.

Asthma ; physiopathology ; Chloride Channels ; physiology ; Cystic Fibrosis ; genetics ; Cystic Fibrosis Transmembrane Conductance Regulator ; genetics ; Epithelium ; physiopathology ; Humans ; Respiratory System ; physiopathology ; Sodium Channels ; physiology

OBJECTIVEThe objective of this paper was to study the expression of related protein and Twist transcription factor of epithelial-mesenchymal transition in oral squamous cell carcinoma (OSCC) tissue and the correlations of OSCC and oral squamous cell carcino-metastasis. The paper also investigated the clinical significance of expression on OSCC.

METHODSThe labels of epithelium materialization (E-cadherin and cytokeratin), stromal labels (N-cadherin), transcription factor Twist protein, and mRNA expression in 30 OSCC tissues were investigated via immunohistochemistry and in situ hybridization. The paper also conducted contrast analysis with clinicopathology.

RESULTSImmunization result showed that the expressions of Twist and N-cadherin in the OSCC group were more significant than those of the normal group (P<0.05). The expressions of E-cadherin and keratin in OSCC were significantly lower than those of the normal group (P<0.05). In the moderate- and low-differentiated group of OSCC, the expressions of Twist and N-cadherin were higher than those of the high-differentiated group (P<0.05). The expressions of E-cadherin and keratin were lower than those in the high-differentiated group (P<0.05). In the lymphatic metastasis group, the expressions of Twist and N-cadherin were higher than those of no-lymphatic metastasis group (P<0.05). The expressions of E-cadherin and keratin were lower than those of the no-lymphatic metastasis group (P< 0.05). Results of in situ hybridization showed that the expression of Twist mRNA in the moderate- and low-differentiated groups of OSCC, T3, and T4 groups as well as that of the lymphatic metastasis group were higher than those of the high-differentiated, T1 and T2 groups, and no-separate lymphatic metastasis group, and the differences were statistically significant (P<0.05).

CONCLUSIONEpithelium materialization exists in OSCC tissue. Twist can enhance the invasiveness of tumor cell and promote the infiltration and metastasis of OSCC. The combined detection of Twist, E-cadherin, and N-cadherin expressions can effectively predict and estimate OSCC metastasis.

Cadherins ; Carcinoma, Squamous Cell ; metabolism ; Epithelial Cells ; Epithelial-Mesenchymal Transition ; physiology ; Epithelium ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Mouth Neoplasms ; metabolism ; RNA, Messenger ; Twist-Related Protein 1 ; metabolism

PURPOSE: To investigate the effects of resveratrol on the expression of hypoxia-inducible factor 1alpha (HIF-1alpha) and vascular endothelial growth factor (VEGF) in human adult retinal pigment epithelial (ARPE-19) cells, and on experimental choroidal neovascularization (CNV) in mice. MATERIALS AND METHODS: ARPE-19 cells were treated with different concentrations of resveratrol and then incubated under hypoxic conditions with subsequent evaluation of cell viability, expression of HIF-1alpha, and expression of VEGF. The effects of resveratrol on the synthesis and degradation of hypoxia-induced HIF-1alpha were evaluated using inhibitors of the PI3K/Akt/mTOR and the ubiquitin proteasome pathways. In animal studies, CNV lesions were induced in C57BL/6 mice by laser photocoagulation. After 7 days of oral administration of resveratrol or vehicle, which began one day after CNV induction, image analysis was used to measure CNV areas on choroidal flat mounts stained with isolectin IB4. RESULTS: In ARPE-19 cells, resveratrol significantly inhibited HIF-1alpha and VEGF in a dose-dependent manner, by blocking the PI3K/Akt/mTOR signaling pathway and by promoting proteasomal HIF-1alpha degradation. In mice experiments, orally administered resveratrol significantly inhibited CNV growth in a dose-dependent manner. CONCLUSION: Resveratrol may have therapeutic value in the management of diseases involving pathological neovascularization.
Adult ; Animals ; Anoxia/metabolism/physiopathology ; Cell Survival/drug effects ; Choroidal Neovascularization/*metabolism/pathology ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit/*drug effects/metabolism ; Mice ; Mice, Inbred C57BL ; Phosphatidylinositol 3-Kinases/antagonists & inhibitors/*physiology ; Proteasome Endopeptidase Complex ; Proto-Oncogene Proteins c-akt/antagonists & inhibitors/*physiology ; Retinal Pigment Epithelium/*drug effects/metabolism ; Signal Transduction ; Stilbenes/administration & dosage/*pharmacology ; TOR Serine-Threonine Kinases/antagonists & inhibitors/*physiology ; Ubiquitin ; Vascular Endothelial Growth Factor A/*drug effects/metabolism

PURPOSE: To evaluate the effects of bevacizumab on expression of B-cell leukemia/lymphoma (Bcl)-2 and apoptosis in retinal pigment epithelial (RPE) cells under oxidative stress conditions. METHODS: RPE cells were treated with H2O2 (0, 100, 200, 300, and 400 microM) and bevacizumab at or above the doses normally used in clinical practice (0, 0.33, 0.67, 1.33, and 2.67 mg/mL). Cell apoptosis was measured using flow cytometry with annexin V-fluorescein isothiocyanate. The expression of Bcl-2 mRNA was determined using reverse transcription polymerase chain reaction. RESULTS: Under low oxidative stress conditions (H2O2 100 microM), cell apoptosis was not significantly different at any concentration of bevacizumab, but Bcl-2 mRNA expression decreased with increasing concentration of bevacizumab (0.33, 0.67, 1.33, and 2.67 mg/mL). Under moderate oxidative stress conditions (H2O2 200 microM), Bcl-2 mRNA expression decreased with increasing concentration of bevacizumab (0.33, 0.67, 1.33, and 2.67 mg/mL), but cell apoptosis increased only at 2.67 mg/mL of bevacizumab. Under high oxidative stress (300 microM) conditions, cell apoptosis increased at high concentrations of bevacizumab (1.33 and 2.67 mg/mL), but it did not correlate with Bcl-2 expression. CONCLUSIONS: Withdrawal of vascular endothelial growth factor can lead to RPE cell apoptosis and influences the expression of anti-apoptotic genes such as Bcl-2 under oxidative stress conditions. Since oxidative stress levels of each patient are unknown, repeated injections of intravitreal bevacizumab, as in eyes with age-related macular degeneration, might influence RPE cell survival.
Angiogenesis Inhibitors/*pharmacology ; Apoptosis/*drug effects ; Bevacizumab/*pharmacology ; Cell Line ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Gene Expression Regulation/physiology ; Humans ; Hydrogen Peroxide/toxicity ; Oxidative Stress/drug effects ; Proto-Oncogene Proteins c-bcl-2/*genetics ; RNA, Messenger/genetics ; Real-Time Polymerase Chain Reaction ; Retinal Pigment Epithelium/*drug effects/metabolism/pathology ; Vascular Endothelial Growth Factor A/antagonists & inhibitors

The aim of this work was to investigate developmental changes in cell proliferation and apoptosis in normal duck bursa of Fabricius using flow cytometry and immunohistochemistry. Studies were carried out on Tianfu ducks on days 24 and 27 of embryogenesis (E24 and E27) along with days 20, 70, and 200 of postnatal development (P20, P70, and P200). Results showed that the percentage of G0/G1 bursa cells significantly increased between E24 and P200 while the percentage of cells in the S phase or G2 + M phase as well as the proliferating index obviously decreased during the same period. Proliferation cell nuclear antigen was detected in lymphocyte and interfollicular epithelium. The proliferative lymphocyte density tended to decrease from E24 to P200. Apoptotic bodies in macrophages, free apoptotic bodies, or nuclei with condensed chromatin in lymphocytes in follicles were identified by transferase-mediated dUTP nick-end labeling. Both flow cytometry and microscopic analysis reveal that the proportion of apoptotic cells and apoptotic lymphocyte density increased from E24 to P20, fell on P70, then rose again on P200. Our foundings demonstrate that cell proliferation decreases and apoptosis increases with age. These changes may account for duck bursa development and involution.
Animals ; *Apoptosis ; Bursa of Fabricius/*cytology/embryology/growth & development/*physiology ; Cell Proliferation ; Ducks/embryology/*physiology ; Embryo, Nonmammalian/cytology/embryology ; Embryonic Development ; Epithelium/physiology ; Female ; Flow Cytometry/veterinary ; Immunohistochemistry/veterinary ; Lymphocytes/physiology ; Male

OBJECTIVETo investigate the role of nicotinamide-adenine dinucleotide phosphate (NADPH) oxidasedependent formation of reactive oxygen species (ROS) in the transforming growth factor β1 (TGF-β1)-induced epithelial-mesenchymal transition (EMT) in rat peritoneal mesothelial cells (RPMCs), and the effect of Astragalus injection (AGI) intervention.

METHODSPrimary RPMCs were cultured to the second generation in vitro. After synchronization for 24 h, the cells were randomly assigned to the following groups: control (Group A), AGI (2 g/mL; Group B), TGF-β1 (10 ng/mL; Group C), TGF-β1 (10 ng/mL) + AGI (2 g/mL; Group D; pretreated for 1 h with AGI before TGF-β1 stimulation). Reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis were employed to evaluate the mRNA and protein expression of the NADPH oxidase subunit p67phox, α-smooth muscle actin (α-SMA) and E-cadherin. The dichlorofluorescein-sensitive cellular ROS levels were measured by a fluorometric assay and confocal microscopy.

RESULTSTGF-β1 significantly induced NADPH oxidase subunit p67phox mRNA and protein expression in RPMCs, as well as inducing the production of intracellular ROS. AGI inhibited this TGF-β1-induced up-regulation by 39.3% and 47.8%, respectively (P<0.05), as well as inhibiting the TGF-β1-induced ROS generation by 56.3% (P<0.05). TGF-β1 also induced α-SMA mRNA and protein expression, and down-regulated E-cadherin mRNA and protein expression (P<0.05). This effect was suppressed by AGI (P<0.05).

CONCLUSIONSNADPH oxidase-dependent formation of ROS may mediate the TGF-β1-dependent EMT in RPMCs. AGI could inhibit this process, providing a theoretical basis for AGI in the prevention of peritoneal fibrosis.

Animals ; Base Sequence ; DNA Primers ; Epithelial-Mesenchymal Transition ; physiology ; Epithelium ; NADPH Oxidases ; metabolism ; Peritoneal Cavity ; cytology ; Polymerase Chain Reaction ; Rats ; Reactive Oxygen Species ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Transforming Growth Factor beta1 ; physiology

The regulated transport of salt and water is essential to the integrated function of many organ systems, including the respiratory, reproductive, and digestive tracts. Airway epithelial fluid secretion is a passive process that is driven by osmotic forces, which are generated by ion transport. The main determinant of a luminally-directed osmotic gradient is the mucosal transport of chloride ions (Cl(-)) into the lumen. As with many epithelial cells, a number of classic signal transduction cascades are involved in the regulation of ion transport. There are two well-known intracellular signaling systems: an increase in intracellular Ca(2+) concentration ([Ca(2+)]i) and an increase in the rate of synthesis of cyclic nucleotides, such as cyclic adenosine monophosphate (cAMP). Therefore, Cl(-) secretion is primarily activated via the opening of apical Ca(2+)- or cAMP-dependent Cl(-) channels at the apical membrane. The opening of basolateral Ca(2+)- or cAMP-activated K(+) channels, which hyperpolarizes the cell to maintain the driving force for Cl(-) exit through apical Cl(-) channels that are constitutively open, is also important in regulating transepithelial ion transport. P2Y receptors are expressed in the apical and/or basolateral membranes of virtually all polarized epithelia to control the transport of fluid and electrolytes. Human airway epithelial cells express multiple nucleotide receptors. Extracellular nucleotides, such as UTP and ATP, are calcium-mobilizing secretagogues. They are released into the extracellular space from airway epithelial cells and act on the same cell in an autocrine fashion to stimulate transepithelial ion transport. In addition, recent data support the role of P2Y receptors in releasing inflammatory cytokines in the bronchial epithelium and other immune cells.
Biological Transport ; Cell Membrane ; physiology ; Chloride Channels ; physiology ; Cyclic AMP ; physiology ; Cytokines ; immunology ; Epithelial Cells ; physiology ; Epithelium ; immunology ; physiology ; Humans ; Ion Transport ; Receptors, Purinergic P2Y ; immunology ; physiology ; Signal Transduction