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To investigate the expressions of the pannexin (Panx) proteins in I-10 Leydig tumor cells and TM3 Leydig cells and their regulatory effect on the Panx channel function in mice.The expressions of the Panx-1 and Panx-2 proteins in the mouse Leydig tumor cells were determined by Western blot. The I-10 Leydig tumor cells were treated with carbenoxolone (CBX) at 100 μmol/L or probenecid (PBN) at 200 μmol/L, the fluorescence resonance energy transfer (FRET) detected by time-lapse fluorescence imaging, and the extracellular adenosine 5'-triphosphate (eATP) level measured with the commercial detection kit. Molecular biological methods were used to interfere with shRNA and overexpress mPanx-1 the Panx-1 gene and regulate the expression and function of the Panx-1 protein.The expressions of Panx-1 (［289.5 ± 55.8］%) and Panx-2 (［264.5 ± 24.6］%) were significantly increased in the I-10 Leydig tumor cells as compared with those in the normal TM3 Leydig cells (both P0.05). FRET was remarkably reduced after treated with CBX (［87.5 ± 17.7］%) and PBN (［89.3 ± 14.3］%) in comparison with that in the control group (both P0.01). At 8, 16 and 24 hours, the eATP level was decreased by (57.3 ± 7.2)%, (56.4 ± 9.6)% and (63.4 ± 6.4)% in the CBX group (P0.01) and (61.7 ± 2.5)%, (35.8 ± 1.6)% and (13.5 ± 8.3)% in the PBN group (P0.01). Molecular biological treatment down-regulated the expression of Panx-1 by (38.3 ± 5.2)% and (31.8 ± 5.1)% in the shRNA1 and shRNA2 groups, respectively (both P0.01), but up-regulated that of Panx-1 by (128.4 ± 7.5)% in the mPanx-1 group (P0.01) as compared with the negative control. FRET was reduced by (72.4 ± 39.4)% in the shRNA group (P0.01) and the eATP level by (14.7 ± 0.1)%, (13.7 ± 0.3)% and (13.1 ± 0.3)% at 8, 16 and 24 hours, respectively (P0.01) while FRET elevated by (122.5 ± 17.1)% in the mPanx-1 group (P0.01) and the eATP level by (886.1 ± 82.1)%, (885.8 ± 83.3)% and (841.5 ± 21.8)% at 8, 16 and 24 hours, respectively (P0.01).The expressions of Panx-1 and Panx-2 are increased in I-10 mouse Leydig tumor cells, and inhibiting the Panx channel with CBX, PBN and shRNA reduces FRET and the eATP level in the I-10 cells.

Background: Dendritic cells are professional antigen-presenting cells found in an immature state in epithelia and interstitial space, where they capture antigens such as pathogens or damaged tissue. Matrix metallopeptidase 13 (MMP-13), a member of the collagenase subfamily, is involved in many different cellular processes and is expressed in murine bone marrow-derived dendritic cells (DCs). The function of MMP-13 in DCs is not well understood. Here, we investigated the effect of MMP-13 on DC maturation, apoptosis, and phagocytosis. Methods: Bone marrow-derived dendritic cells were obtained from C57BL/6 mice. One short-interfering RNA specific for MMP-13 was used to transfect DCs. MMP-13-silenced DCs and control DCs were prepared, and apoptosis was measured using real-time polymerase chain reaction and Western blotting. MMP-13-silenced DCs and control DCs were analyzed for surface expression of CD80 and CD86 and phagocytosis capability using flow cytometry. Results: Compared to the control DCs, MMP-13-silenced DCs increased expression of anti-apoptosis-related genes, BAG1 (control group vs. MMP-13-silenced group: 4.08 ± 0.60 vs. 6.11 ± 0.87, P = 0.008), BCL-2 (control group vs. MMP-13-silenced group: 7.54 ± 0.76 vs. 9.54 ± 1.29, P = 0.036), and TP73 (control group vs. MMP-13-silenced group: 4.33 ± 0.29 vs. 5.60 ± 0.32, P = 0.001) and decreased apoptosis-related genes, CASP1 (control group vs. MMP-13-silenced group: 3.79 ± 0.67 vs. 2.54 ± 0.39, P = 0.019), LTBR (control group vs. MMP-13-silenced group: 9.23 ± 1.25 vs. 6.24 ± 1.15, P = 0.012), and CASP4 (control group vs. MMP-13-silenced group: 2.07 ± 0.56 vs. 0.35 ± 0.35, P = 0.002). Protein levels confirmed the same expression pattern. MMP-13-silenced groups decreased expression of CD86 on DCs; however, there was no statistical difference in CD80 surface expression. Furthermore, MMP-13-silenced groups exhibited weaker phagocytosis capability. Conclusion: These results indicate that MMP-13 inhibition dampens DC maturation, apoptosis, and phagocytosis. Key words: Apoptosis; Dendritic Cell; Matrix Metallopeptidase 13; Maturation; Phagocytosis

Zinc oxide nanoparticles (ZnO NPs) are widely used in a variety of products used in daily life. However, their impact on human health has not been completely elucidated. This study was designed to investigate the cytotoxicity associated with ZnO NPs, the role of dissolution in the toxicity of ZnO NPs, the molecular mechanisms and mode of cell death induced by ZnO NPs in human aortic endothelial cells (HAECs), and the protective effects of the antioxidant alpha-lipoic acid (LA). ZnO NPs significantly reduced cell viability in a dose- and time-dependent manner, resulted in intracellular oxidative stress and cell membrane leakage when treated with doses of 8–50 μg/mL for 12 and 24 h in HAECs. The toxicity was produced by undissolved ZnO NPs but not dissolved Zn2+ and metal impurities. Exposure to ZnO NPs was found to induce apoptosis at 12 h and necrosis after 24 h. Apoptosis was confirmed using reactive oxygen species that triggered a decrease in mitochondria membrane potential, increase in Cyt-C release, activation of caspases 3 and caspases9 and increase in the ratio of Bax/Bcl-2. Futhermore, ZnO NPs could activate the Fas death receptor pathway. In addition, the antioxidant LA was able to protect HAECs from apoptosis induced by ZnO NPs.

To investigate the role of pannexin 1 channels in cisplatin-induced apoptosis in I-10 cells and the mechanisms.MTT assay was used to assess the cytotoxicity of cisplatin (DDP) in I-10 cells. Annexin V/PI double staining and Hoechst 33258 fluorescence staining were employed to detect early- and late-stage apoptosis of the cells, respectively. Extracellular ATP level and intracellular IP3 level in the cells were detected using commercial detection kits.I-10 cells exposed to both CBX (a pannexin 1 channel inhibitor) and DDP showed a higher cell viability compared with the cells exposed to DDP alone (P0.01). CBX significantly decreased cisplatin-induced early-stage apoptosis (P0.001) and late-stage apoptosis (P0.01), and cause obvious reductions in extracellular ATP and intracellular IP3 levels during cisplatin-induced apoptosis (P0.05).Pannexin 1 channels participate in cisplatin-induced apoptosis in I-10 cells possibly through the ATP/IP3 pathway.

To investigate the effect of baicalein on the gap junction intercellular communication (GJIC) in the TM4 Sertoli cells of the mouse testis and its related mechanism.We measured the cytotoxicity of different concentrations of baicalein on the TM4 Sertoli cells in the mouse testis by MTT, detected the fluorescence transfer of the TM4 Sertoli cells by parachute assay, and determined the expression of the protein connexin 43 ( Cx43) in the baicalein-treated cells by Western blot and immunofluorescence assay.Baicalein produced no obvious cytotoxicity on the TM4 Sertoli cells at the concentration below 60 µmol/L but significantly increased their GJIC at 0-20 µmol/L (P0.01). Western blot and immunofluorescence assay showed that 0-20 µmol/L baicalein remarkably elevated the expression of Cx43 in the TM4 cells (P0.01) and on the membrane of the TM4 cells.Baicalein at the concentration of 0-20 µmol/L can significantly enhance GJIC in mouse TM4 Sertoli cells by increasing the expression of the Cx43 protein.

To investigate the effects of inhibiting gap junctional intercellular communication on hypoxia/reoxygenation injury in astrocytes.Primary cultured cerebral cortical astrocytes of neonate rats were divided into normal control group, hypoxia reoxygenation injury group and 18-α-glycyrrhetinic acid and oleamide (gap junctional intercellular channel inhibitors) group. The gap junction intercellular communication was determined by Parachute assay. The viability of astrocyes was detected by MTT assay. The apoptosis of astrocytes were detected with annexin V/PI and Hoechst 33258 staining.Compared with the normal control group, the gap junctional function of astrocytes was increased significantly in ischemia/reperfusion group (P0.01), the surviving fraction of astrocytes decreased significantly (P0.01) and its cell apoptosis ratio increased significantly (P0.01). Compared with the ischemia/reperfusion group, the gap junctional function of astrocytes in18-α-glycyrrhetinic acid and oleamide group decreased significantly (P0.01), the viability of astrocytes increased significantly (P0.01), while cell apoptosis decreased significantly (P0.01).Inhibition of intercellular gap junction has protective effect against hypoxia/reoxygenation injury in astrocytes.

To investigate the effect of sodium valproate, a histone deacetylase inhibitor, on the cytotoxicity of doxorubicin in breast cancer cells.Western blotting was used to assess Cx43 protein expression in breast cancer Hs578T cells exposed to doxorubicin and sodium valproate. MTT assay was used to determine the cytotoxicity of doxorubicin; annexin V/PI double staining and Hochest 33258 fluorescence staining were employed to detect doxorubicin-induced early and late apoptosis, respectively.Western blotting showed that sodium valproate significantly increased Cx43 protein expression in Hs578T cells (P/0.01). The cells exposed to both sodium valproate and doxorubicin showed significantly lowered cell viability compared with the cells exposed to doxorubicin alone (P/0.01). Exposure to both sodium valproate and doxorubicin resulted in significantly increased early and late cell apoptosis rate compared with doxorubicin treatment alone (P/0.01).sodium valproate can significantly enhance the cytotoxicity of doxorubicin and increase doxorubicin-induced apoptosis in breast cancer cells in vitro possibly by enhancing the gap junction function.

To investigate the effects of total flavonoids of Litsea Coreana (TFLC) on the gap junction (GJ) intercellular communication in TM3 testicular Leydig cells and whether TFLC can reduce the cytotoxicity of oxaliplatin (OHP) in vitro.We detected the effect of TFLC on the dye spread of the in vitro cultured TM3 cells by parachute assay, observed changes in the expression of connexin 43 (Cx43) total protein in the TFLC-treated TM3 cells by Western blot, and determined the effects of TFLC on the expression of Cx43 on the membrane of the TM3 cells by immunofluorescence assay and on the cytotoxicity of OHP by MTT assay.TFLC obviously enhanced the GJ function with the increasing of the TFLC concentration in the TM3 cells. Western blot and immunofluorescence assay confirmed that TFLC significantly enhanced the expression of Cx43 total protein and Cx43 expression on the membrane of the TM3 cells. MTT assay showed that at a high cell density (confluent with GJ formation), 20 microg/ml TFLC enhanced the GJ function of the TM3 cells and reduced the cytotoxicity of OHP (P0.05), while at a low density (preconfluent with no GJ formation), TFLC exhibited no effect on the cytotoxicity of OHP (P0.05).TFLC increases the Cx43 expression and GJ function in normal TM3 Leydig cells, and the enhancement of GJ function reduces the cytotoxicity of OHP.

To investigate the effects of retinoic acid (RA) on the expression of Cx43 and its gap junction intercellular communication function in testicular cancer cells.Cultured testicular cancer cells I-10 were treated with different concentration of RA (2.5, 5.0,10.0 micromol/L). The expression of Cx43 in 1-10 cells was detected by Western blot, and the distribution and location of Cx43 on cellular membrane was studied with immunofluorescence assay. Parachute assay was used to detect the function of gap junction intercellular communication composed of Cx43 in 1-10 cells.RA (2.5, 5.0, 10.0 micromol/L) markedly increased the expression of Cx43 in I-10 cells, the enhancement ratios were 43.14% +/- 2.1%, 58.09% +/- 1.8%, 143.13% +/- 1.6%, respectively. The result of immunofluorescence assay showed that RA (2.5, 5.0, 10.0 micromol/L) obviously increased the level of Cx43 located on the cellular membrane of I-10 cells. The result of parachute assay demonstrated that RA (2.5,5.0,10.0 gmol/L) could enhance the intercellular dye coupling through gap junction, the enhancement ratios were 26.1% +/- 2.3%, 63.3% +/- 1.6%, 140.5% +/- 3.4%, respectively.RA could enhance the gap junction intercellular communication by increasing the expression of Cx43 in I-10 cells.

The toxicity and carcinogenicity of aniline in humans and animals have been well documented. However, the molecular mechanism involved in aniline-induced liver toxicity and carcinogenesis remains unclear. In our research, primary cultured hepatocytes were exposed to aniline (0, 1.25, 2.50, 5.0 and 10.0 μg/mL) for 24 h in the presence or absence of N-acetyl-l-cysteine (NAC). Levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH), activities of superoxide dismutase (SOD) and catalase (CAT), mitochondrial membrane potential, DNA damage, cell viability, and apoptosis were detected. Levels of ROS and MDA were significantly increased and levels of GSH and CAT, activity of SOD, and mitochondrial membrane potential in hepatocytes were significantly decreased by aniline compared with the negative control group. The tail moment and DNA content of the tail in exposed groups were significantly higher than those in the negative control group. Cell viability was reduced and apoptotic death was induced by aniline in a concentration-dependent manner. The phenomena of ROS generation, oxidative damage, loss of mitochondrial membrane potential, DNA damage and apoptosis could be prevented if ROS inhibitor NAC was added. ROS generation is involved in the loss of mitochondrial membrane potential and DNA injury, which may play a role in aniline-induced apoptosis in hepatocytes. Our study provides insight into the mechanism of aniline-induced toxicity and apoptosis of hepatocytes.

To observe the influence of Cx26/Cx32 gap junction channel on the antineoplastic effect of etoposide in Hela cervical cancer cells.Fluorescence trace was used to assay the gap junction intercellular communication mediated by Cx26/Cx32 in Hela cells and its functional modulation by the pharmacological agents (oleamide, retinoid acid). A standard colony-forming assay was applied to determine the cell growth-inhibiting effect of etoposide in Hela cells with functional modulation of the gap junction. Hoechst 33258 staining was used to assess the changes in etoposide-induced apoptosis of Hela cells with altered gap junction functions.Oleamide markedly decreased while retinoid acid obviously increased the gap junction function in Hela cells. Standard colony-forming assay showed that etoposide produced a lowered antiproliferative effect in Hela cells with reduced gap junction and an increased antiproliferative effect in cells with enhanced gap junction function. In cells with a reduced gap junction function, etoposide induced a lowered apoptosis rate, which increased obviously in cells with an enhanced gap junction function.The antineoplastic effect of etoposide is reduced in Hela cells with a decreased gap junction intercellular communication mediated by Cx26/Cx32 and is enhanced in cells with an increased gap junction intercellular communication.

We report a case of an intramuscular lipoma with the following karyotype: 46,XY,t(12;14) (q14–15;q24). To our knowledge, this is the third report of a t(12;14) as a sole abnormality in a lipoma.