Epithelial attachment via the basal lamina on the tooth surface provides an important structural defence mechanism against bacterial invasion in combating periodontal disease. However, when considering dental implants, strong epithelial attachment does not exist throughout the titanium-soft tissue interface, making soft tissues more susceptible to peri-implant disease. This study introduced a novel synthetic peptide (A10) to enhance epithelial attachment. A10 was identified from a bacterial peptide display library and synthesized. A10 and protease-activated receptor 4-activating peptide (PAR4-AP, positive control) were immobilized on commercially pure titanium. The peptide-treated titanium showed high epithelial cell migration ability during incubation in platelet-rich plasma. We confirmed the development of dense and expanded BL (stained by Ln5) with pericellular junctions (stained by ZO1) on the peptide-treated titanium surface. In an adhesion assay of epithelial cells on A10-treated titanium, PAR4-AP-treated titanium, bovine root and non-treated titanium, A10-treated titanium and PAR4-AP-treated titanium showed significantly stronger adhesion than non-treated titanium. PAR4-AP-treated titanium showed significantly higher inflammatory cytokine release than non-treated titanium. There was no significant difference in inflammatory cytokine release between A10-treated and non-treated titanium. These results indicated that A10 could induce the adhesion and migration of epithelial cells with low inflammatory cytokine release. This novel peptide has a potentially useful application that could improve clinical outcomes with titanium implants and abutments by reducing or preventing peri-implant disease.
Amino Acid Sequence ; Animals ; Benzeneacetamides ; chemical synthesis ; pharmacology ; Cattle ; Cell Adhesion ; drug effects ; Cell Movement ; drug effects ; Cells, Cultured ; Cytokines ; metabolism ; Dental Implants ; Enzyme-Linked Immunosorbent Assay ; Epithelial Attachment ; drug effects ; Epithelial Cells ; cytology ; metabolism ; Microscopy, Confocal ; Microscopy, Electron, Scanning ; Piperidones ; chemical synthesis ; pharmacology ; Platelet-Rich Plasma ; Receptors, Thrombin ; Surface Properties ; Titanium ; chemistry

Astragalus membranaceus (Radix Astragali, RA) and Atractylodes macrocephala (Rhizoma Atractylodis Macrocephalae, RAM) are often used to treat gastrointestinal diseases. In the present study, we determined the effects of polysaccharides extracts from these two herbs on IEC-6 cell migration and explored the potential underlying mechanisms. A migration model with IEC-6 cells was induced using a single-edged razor blade along the diameter of cell layers in six-well polystyrene plates. The cells were grown in control media or media containing spermidine (5 μmol·L, SPD), alpha-difluoromethylornithine (2.5 mmol·L, DFMO), 4-Aminopyridine (40 μmol·L, 4-AP), the polysaccharide extracts of RA or RAM (50, 100, or 200 mg·L), DFMO plus SPD, or DFMO plus polysaccharide extracts of RA or RAM for 12 or 24 h. Next, cytosolic free Ca ([Ca]) was measured using laser confocal microscopy, and cellular polyamine content was quantified with HPLC. Kv1.1 mRNA expression was assessed using RT-qPCR and Kv1.1 and RhoA protein expressions were measured with Western blotting analysis. A cell migration assay was carried out using Image-Pro Plus software. In addition, GC-MS was introduced to analyze the monosaccharide composition of both polysaccharide extracts. The resutls showed that treatment with polysaccharide extracts of RA or RAM significantly increased cellular polyamine content, elevated [Ca] and accelerated migration of IEC-6 cells, compared with the controls (P < 0.01). Polysaccharide extracts not only reversed the inhibitory effects of DFMO on cellular polyamine content and [Ca], but also restored IEC-6 cell migration to control level (P < 0.01 or < 0.05). Kv1.1 mRNA and protein expressions were increased (P < 0.05) after polysaccharide extract treatment in polyamine-deficient IEC-6 cells and RhoA protein expression was increased. Molar ratios of D-ribose, D-arabinose, L-rhamnose, D-mannose, D-glucose, and D-galactose was 1.0 : 14.1 : 0.3 : 19.9 : 181.3 : 6.3 in RA and 1.0 : 4.3 : 0.1 : 5.7 : 2.8 : 2.2 in RAM. In conclusion, treatment with RA and RAM polysaccharide extracts stimulated migration of intestinal epithelial cells via a polyamine-Kv1.1 channel activated signaling pathway, which facilitated intestinal injury healing.
Animals ; Astragalus propinquus ; chemistry ; Atractylodes ; chemistry ; Cell Line ; Cell Movement ; drug effects ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; pharmacology ; Epithelial Cells ; cytology ; drug effects ; metabolism ; Intestines ; cytology ; drug effects ; Kv1.1 Potassium Channel ; genetics ; metabolism ; Polyamines ; metabolism ; Polysaccharides ; chemistry ; isolation & purification ; pharmacology ; Rats ; Rhizome ; chemistry ; Signal Transduction ; drug effects ; rhoA GTP-Binding Protein ; metabolism

PURPOSE: Diabetic nephropathy (DN) is a prevalent chronic microvascular complication of diabetes mellitus involving disturbances in electrolytes and the acid-base balance caused by a disorder of glucose metabolism. NHE1 is a Na+/H+ exchanger responsible for keeping intracellular pH (pHi) balance and cell growth. Our study aimed to investigate roles of NHE1 in high glucose (HG)-induced apoptosis in renal tubular epithelial cells. MATERIALS AND METHODS: Renal epithelial tubular cell line HK-2 was cultured in medium containing 5 mM or 30 mM glucose. Then, cell apoptosis, oxidative stress, NHE1 expression, and pHi were evaluated. NHE1 siRNA and inhibitor were used to evaluate its role in cell apoptosis. RESULTS: HG significantly increased cell apoptosis and the production of reactive oxygen species (ROS) and 8-OHdG (p<0.05). Meanwhile, we found that HG induced the expression of NHE1 and increased the pHi from 7.0 to 7.6 after 48 h of incubation. However, inhibiting NHE1 using its specific siRNA or antagonist DMA markedly reduced cell apoptosis stimulated by HG. In addition, suppressing cellular oxidative stress using antioxidants, such as glutathione and N-acetyl cysteine, significantly reduced the production of ROS, accompanied by a decrease in NHE1. We also found that activated cyclic GMP-Dependent Protein Kinase Type I (PKG) signaling promoted the production of ROS, which contributed to the regulation of NHE1 functions. CONCLUSION: Our study indicated that HG activates PKG signaling and elevates the production of ROS, which was responsible for the induction of NHE1 expression and dysfunction, as well as subsequent cell apoptosis, in renal tubular epithelial cells.
Antioxidants/metabolism ; Apoptosis/*drug effects ; Cation Transport Proteins/*metabolism ; Cell Cycle/drug effects ; Cell Line ; Dose-Response Relationship, Drug ; Epithelial Cells/*cytology/drug effects/*metabolism ; Glucose/*pharmacology ; Glutathione/metabolism ; Humans ; Kidney Tubules/*cytology ; Oxidative Stress/*drug effects ; Reactive Oxygen Species/metabolism ; Signal Transduction/drug effects ; Sodium-Hydrogen Antiporter/*metabolism

OBJECTIVETo investigate the effect of arctiin on advanced oxidation protein product (AOPP)-induced epithelial-to-mesenchymal transition (EMT) in tubular cells and explore the mechanisms underlying this effect.

METHODSHuman proximal tubular cells (HK-2 cells) were treated with bovine serum albumin (BSA) or AOPPs in the presence or absence of arctiin. The expressions of E-cadherin, vimentin, and GRP78 at the protein and mRNA levels in the cells were examined using Western blotting and quantitative real-time PCR. The level of reactive oxygen species (ROS) was measured by flow cytometry with DCFH-DA as the fluorescent probe.

RESULTSCompared with BSA-treated cells, the cells treated with AOPPs showed decreased expression of epithelial cell marker E-cadherin and overexpression of mesenchymal marker vimentin and endoplasmic reticulum stress marker GRP78 with an increased ROS level. These changes induced by AOPPs were partly inhibited by arctiin.

CONCLUSIONArctiin can ameliorate AOPP-induced EMT in tubular cells by inhibiting endoplasmic reticulum stress, and oxidative stress response may participate in this process.

Advanced Oxidation Protein Products ; adverse effects ; Cadherins ; metabolism ; Cell Line ; Endoplasmic Reticulum Stress ; Epithelial Cells ; cytology ; drug effects ; Epithelial-Mesenchymal Transition ; Furans ; pharmacology ; Glucosides ; pharmacology ; Heat-Shock Proteins ; metabolism ; Humans ; Kidney Tubules ; cytology ; drug effects ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; Vimentin ; metabolism

Biliverdin (BV) has long been thought to be a cytotoxic metabolic waste product. It has also been demonstrated to have important cytoprotective functions during oxidative stress. The present study aimed to examine the cytoprotective effect of BV on NRK-52E cells, a proximal tubular cell line derived from rat kidney. Cells were treated with 50 µmol/L cisplatin for 24 h (cisplatin group) or pre-treated with BV for 30 min, then with 50 µmol/L cisplatin for 24 h (cisplatin+BV group). Those given no treatment served as a control. Cell apoptosis was evaluated by flow cytometry and cell viability by Cell Counting Kit-8 (CCK-8). The protein expressions of cleaved caspase3, Bax and Bcl-2 were assessed by Western blotting. Reactive oxygen species (ROS) levels were measured using carboxydichlorodihydrofluorescein diacetate (H2DCF). The results showed that cisplatin induced the apoptosis of NRK-52E cells, decreased cell viability, and increased the formation of ROS by upregulating the expression of cleaved caspase3 and Bax and decreasing Bcl-2 protein expression. These effects could be significantly reversed by pretreatment with BV. It was concluded that BV can protect against cisplatin-induced cell apoptosis through the anti-oxidative effects.
Animals ; Antioxidants ; pharmacology ; Apoptosis ; Biliverdine ; pharmacology ; Cell Line ; Cisplatin ; toxicity ; Epithelial Cells ; drug effects ; metabolism ; Kidney Tubules ; cytology ; Rats ; Reactive Oxygen Species ; metabolism

Carbon monoxide (CO), as a vital small molecule in signaling pathways, is found to be involved in ischemia-reperfusion injury (IRI) in renal transplantation. CO-releasing molecule-2 (CORM-2), a CO-releasing molecule, is a type of metal carbonyl complexes which can quickly release CO in vivo. In this study, an in vitro oxidative stress injury model was established to examine the effect of CORM-2 pretreatment on the nuclear-cytoplasmic translocation of high mobility group box 1 protein (HMGB1) in mouse primary renal proximal tubular epithelial cells (RPTECs). Immunofluorescence staining showed that HMGB1 in the medium- and CORM-2-treated groups was predominantly localized in the nucleus of the cells, whereas higher amounts of HMGB1 translocated to the cytoplasm in the HO- and inactive CORM-2 (iCORM-2)-treated groups. Western blotting of HMGB1 showed that the total amounts of cytoplasmic HMGB1 in the HO-treated (0.59±0.27) and iCORM-2-treated (0.57±0.22) groups were markedly higher than those in the medium-treated (0.19±0.05) and CORM-2-treated (0.21±0.10) groups (P<0.05). Co-immunoprecipitation showed that the levels of acetylated HMGB1 in the HO-treated (642.98±57.25) and iCORM-2-treated (342.11±131.25) groups were markedly increased as compared with the medium-treated (78.72±74.17) and CORM-2-treated (71.42±53.35) groups (P<0.05), and no significant difference was observed between the medium-treated and CORM-2-treated groups (P>0.05). In conclusion, our study demonstrated that in the in vitro oxidative stress injury model of primary RPTECs, CORM-2 can significantly inhibit the nuclear-cytoplasmic translocation of HMGB1, which is probably associated with the prevention of HMGB1 acetylation.
Active Transport, Cell Nucleus ; drug effects ; Animals ; Carbon Monoxide ; pharmacology ; Cell Nucleus ; metabolism ; Cells, Cultured ; Epithelial Cells ; drug effects ; metabolism ; HMGB1 Protein ; metabolism ; Kidney Tubules ; cytology ; Mice ; Organometallic Compounds ; pharmacology ; Oxidative Stress

BACKGROUNDVascular endothelial growth factor (VEGF) in the thymus was mainly produced by the thymic epithelial cells (TECs), the predominant component of the thymic microenvironment. The progression of TECs and the roles of VEGF in the neonatal thymus during sepsis have not been reported. This study aimed to explore the alterations of TECs and VEGF level in the neonatal thymus involution and to explore the possible mechanisms at the cellular level.

METHODSBy establishing a model of clinical sepsis, the changes of TECs were measured by hematoxylin-eosin staining, confocal microscopy, and flow cytometry. Moreover, the levels of VEGF in serum and thymus were assessed based on enzyme-linked immunosorbent assay and Western blotting.

RESULTSThe number of thymocytes and TECs was significantly decreased 24 h after lipopolysaccharide (LPS) challenge, (2.40 ± 0.46)×10 7 vs. (3.93 ± 0.66)×10 7 and (1.16 ± 0.14)×10 5 vs. (2.20 ± 0.19)×10 5 , P < 0.05, respectively. Cortical TECs and medullary TECs in the LPS-treated mice were decreased 1.5-fold and 3.9-fold, P < 0.05, respectively, lower than those in the controls. The number of thymic epithelial progenitors was also decreased. VEGF expression in TECs was down-regulated in a time-dependent manner.

CONCLUSIONVEGF in thymic cells subsets might contribute to the development of TECs in neonatal sepsis.

Animals ; Animals, Newborn ; Cells, Cultured ; Epithelial Cells ; cytology ; drug effects ; metabolism ; Lipopolysaccharides ; toxicity ; Mice ; Thymus Gland ; cytology ; drug effects ; metabolism ; Vascular Endothelial Growth Factor A ; metabolism

OBJECTIVETo analyze the opioid binding protein/cell adhesion molecule-like (OPCML) methylation status at different stages of malignant transformation of human bronchial epithelial (16HBE) cells induced by Glycidyl Methacrylate (GMA) and to explore the effect of OPCML methylation in the process of malignant transformation.

METHODSCells were harvested at different stages (the 10th generation, the 20th generation and the 30th generation). To verify the Methylation chip result of OPCML methylation status in the process of malignant transformation, we detected it by methylation-specific-PCR (MSP); Real-time fluorescence Quantitative PCR (qPCR) were applied to measure the gene expression levels of OPCML at different transformed stage, and compared with the control groups (treated with DMSO).

RESULTSBased on the result of methylation chip, the gene of OPCML methylation occurred in all stages, which was consistent to the result of MSP; qPCR showed that the levels of gene expression decreased in the 20th generation and 30th generation.

CONCLUSIONMethylation status of OPCML gene promoter could be considered as a stable and specific biomarker in the transformation process.

Cell Adhesion Molecules ; metabolism ; Cell Transformation, Neoplastic ; chemically induced ; Cells, Cultured ; DNA Methylation ; Epithelial Cells ; cytology ; drug effects ; Epoxy Compounds ; adverse effects ; GPI-Linked Proteins ; metabolism ; Genes, Tumor Suppressor ; Humans ; Methacrylates ; adverse effects ; Promoter Regions, Genetic

OBJECTIVETo investigate oxidative stress and mitochondria-related cell apoptosis induced by silica dust in human normal bronchial epithelial 16HBE cells.

METHODSCell viability, lactate dehydrogenase (LDH), superoxide dismutase (SOD), cell apoptotic rate, the expression level of Bax and Bcl-2 mRNA were measured after 16HBE cells were exposed to 37.5, 75, 150, 300 µg/mL respirable silica dust (diameter<2 µm, d50=1 µm)for 24 h in vitro. Reactive oxygen species (ROS)were tested after 16HBE cells were exposed to silica dust at above concentrations for 1.5, 3, 6, 12 h, respectively.

RESULTSDose-dependent decreases of cell viability and the activity of SOD were observed when silica concentrations increased. The activity of LDH increased when silica concentrations elevated. Compared with the control group, cell viability significantly reduced in 75, 150, 300 µg/mL silica-treated groups (P<0.05). The activity of LDH significantly increased in 150, 300 µg/mL silica-treated groups when compared with the control group (P<0.05). The activity of SOD in all silica-treated groups were significantly lower in comparison with controls (P<0.05). Intracellular ROS levels reached peak values at 1.5 h of silica exposure and gradually dropped to the base level at 12 h. The relationship between ROS levels and silica exposure were dose-response at 1.5 h, 3 h and 6 h of exposure (P<0.05). Similar dose-dependent increase were observed for apoptotic rate and silica exposure (P<0.05). The expression levels of Bcl-2 mRNA decreased, and the expression levels of Bax mRNA increased when silica concentrations increased. The results showed that significantly positive correlations between ROS level and apoptotic rate (r=0.892,P<0.05)or the expression level of Bax mRNA (r=0.850,P<0.05). There was a negative correlation between ROS level and the expression level of Bcl-2 mRNA (r=-0.703,P<0.05).

CONCLUSIONSilica dust could induce cytotoxicity, oxidative stress and mitochondria-related cell apoptosis in 16HBE cells. Oxidative stress may play role in the processes of mitochondria-related apoptosis.

Apoptosis ; Cell Survival ; Cells, Cultured ; Dust ; Epithelial Cells ; cytology ; drug effects ; Humans ; L-Lactate Dehydrogenase ; metabolism ; Mitochondria ; Oxidative Stress ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Reactive Oxygen Species ; metabolism ; Silicon Dioxide ; toxicity ; Superoxide Dismutase ; metabolism ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo investigate the effect of silicon dioxide (SiO₂) on the expression of E-cadherin, α-smooth muscle actin (α-SMA), and transforming growth factor β₁(TGF-β₁) in human pulmonary epithelial cells (A549) with epithelial-mesenchymal transition (EMT), and to study the roles of epidermal growth factor receptor (EGFR) signaling pathway in SiO₂-induced EMT in A549 cells in vitro.

METHODSAlveolar macrophages (AMs) were stimulated with 50 µg/ml SiO₂for 3, 6, 12, 18, 24, or 36 h, and the supernatants were collected to measure the expression of TGF-β₁protein by ELISA. The AM supernatant in which TGF-β₁reached the highest expression (T=18 h) was used as AM-conditioned supernatant. A549 cells were cultured in AM-conditioned supernatant and stimulated with indicated doses of SiO₂(0, 50, 100, and 200 µg/ml) for 48 h. The cell morphological changes were observed using an inverted microscope. The cells were collected at different times, and the mRNA and protein expression levels of E-cadherin, α-SMA, and EGFR were measured by RT-PCR and immunocytofluorescence, respectively.

RESULTSAfter stimulation by SiO₂, the expression level of TGF-β₁protein at each time point was significantly higher in the presence of AM supernatants than in the absence of AM supernatants (P<0.05). With the action time, the expression level of TGF-β₁protein increased at first and then decreased, and the highest level was reached at 18 h. After exposure to SiO₂, A549 cells exhibited mesenchymal characteristics, such as a spindle shape, pseudopodia change, and fibroblast-like morphology, as observed by inverted microscope, especially in the 200 µg/ml group. With increased concentration of SiO₂, the mRNA and protein expression of E-cadherin was down-regulated gradually, especially in the 200 µg/ml group, whereas the mRNA and protein expression of α-SMA and EGFR was up-regulated gradually, especially in the 200 µg/m1 group. There were significant differences between the SiO₂-treated groups (50, 100, and 200 µg/ml SiO₂) and the control group (P<0.05).

CONCLUSIONAfter being stimulated by SiO₂in vitro, AMs have significantly increased expression level of TGF-β₁protein. The AM supernatant together with SiO₂can induce the transition of pulmonary epithelial cells to mesenchymal cells, and its mechanism may be related to the EGFR signaling pathway.

Actins ; metabolism ; Cadherins ; metabolism ; Cell Line, Tumor ; Epithelial Cells ; cytology ; metabolism ; Epithelial-Mesenchymal Transition ; drug effects ; Humans ; Lung ; cytology ; Macrophages, Alveolar ; metabolism ; Receptor, Epidermal Growth Factor ; metabolism ; Signal Transduction ; Silicon Dioxide ; pharmacology ; Transforming Growth Factor beta1 ; metabolism