Construction of Bi2WO6/g-C3N4 Z-Scheme Heterojunction and Its Enhanced Photocatalytic Degradation of Tetracycline with Persulfate under Solar Light.

Z-scheme heterojunction Bi2WO6/g-C3N4 was obtained by a novel hydrothermal process; its photocatalysis-persulfate (PDS) activation for tetracycline (TC) removal was explored under solar light (SL). The structure and photoelectrochemistry behavior of fabricated samples were well characterized by FT-IR, XRD, XPS, SEM-EDS, UV-vis DRS, Mott-Schottky, PL, photocurrent response, EIS and BET. The critical experimental factors in TC decomposition were investigated, including the Bi2WO6 doping ratio, catalyst dosage, TC concentration, PDS dose, pH, co-existing ion and humic acid (HA). The optimum test conditions were as follows: 0.4 g/L Bi2WO6/g-C3N4 (BC-3), 20 mg/L TC, 20 mg/L PDS and pH = 6.49, and the maximum removal efficiency of TC was 98.0% in 60 min. The decomposition rate in BC-3/SL/PDS system (0.0446 min-1) was 3.05 times higher than that of the g-C3N4/SL/PDS system (0.0146 min-1), which might be caused by the high-efficiency electron transfer inside the Z-scheme Bi2WO6/g-C3N4 heterojunction. Furthermore, the photogenerated hole (h+), superoxide (O2•-), sulfate radical (SO4•-) and singlet oxygen (1O2) were confirmed as the key oxidation factors in the BC-3/SL/PDS system for TC degradation by a free radical quenching experiment. Particularly, BC-3 possessed a wide application potential in actual antibiotic wastewater treatment for its superior catalytic performance that emerged in the experiment of co-existing components.

Astrocyte-Neuronal Communication and Its Role in Stroke.

Astrocytes are the most abundant glial cells in the central nervous system. These cells are an important hub for intercellular communication. They participate in various pathophysiological processes, including synaptogenesis, metabolic transformation, scar production, and blood-brain barrier repair. The mechanisms and functional consequences of astrocyte-neuron signaling are more complex than previously thought. Stroke is a disease associated with neurons in which astrocytes also play an important role. Astrocytes respond to the alterations in the brain microenvironment after stroke, providing required substances to neurons. However, they can also have harmful effects. In this review, we have summarized the function of astrocytes, their association with neurons, and two paradigms of the inflammatory response, which suggest that targeting astrocytes may be an effective strategy for treating stroke.

The role of PI3K/AKT-related proteins in di(2-ethyl)hexylphthalate-induced BG-1 and MCF-7 cell proliferation, and inhibition by metformin.

OBJECTIVE: To investigate the molecular mechanism of the proliferation and migration of BG-1 and MCF-7cells induced by DEHP, and the antagonistic effect of metformin. METHODS: The proliferation, cell cycle progression, migration, and invasion abilities of BG-1 and MCF-7 cancer cells were examined via Cell Counting Kit-8, flow cytometry, Transwell, and scratch assays. E2F1, SKP2, cyclin D1, vimentin, E-cadherin, and GSK-3ß, all of which play key roles in cancer development via the PI3K/AKT signaling pathway, were examined by immunofluorescence and immunocytochemistry. RESULTS: Cell proliferation was significantly increased, and the wound closure and number of trans-membrane migrating cells were significantly increased, by DHEP treatment. The numbers of BG-1 and MCF-7 cells in the G0/G1 phase were significantly decreased, while those in the S phase were significantly increased. Increased E2F1, SKP2, cyclin D1, and vimentin levels and decreased E-cadherin and GSK-3ß levels were detected in BG-1 and MCF-7 cells treated with DEHP compared to that in control cells. Furthermore, DEHP-induced effects were markedly inhibited by LY294002 (a PI3K/AKT inhibitor) or metformin. CONCLUSION: We demonstrated that DEHP-induced cell proliferation and migration involves the PI3K/AKT signaling pathway and that metformin can be used to inhibit this proliferation and migration.

Magnetic Biochar Derived from Fenton Sludge/CMC for High-Efficiency Removal of Pb(II): Synthesis, Application, and Mechanism.

Magnetic biochar composites (MBC) were developed by a simple one-step pyrolysis method using Fenton sludge waste solid and carboxymethyl cellulose sodium. Detailed morphological, chemical, and magnetic characterizations corroborate the successful fabrication of MBC. Batch adsorption experiments show that the synthesized MBC owns high-efficiency removal of Pb(II), accompanied by ease-of-separation from aqueous solution using magnetic field. The experiment shows that the equilibrium adsorption capacity of MBC for Pb(II) can reach 199.9 mg g-1, corresponding to a removal rate of 99.9%, and the maximum adsorption capacity (qm) reaches 570.7 mg g-1, which is significantly better than that of the recently reported magnetic similar materials. The adsorption of Pb(II) by MBC complies with the pseudo second-order equation and Langmuir isotherm model, and the adsorption is a spontaneous, endothermic chemical process. Investigations on the adsorption mechanism show that the combination of Pb(II) with the oxygen-containing functional groups (carboxyl, hydroxyl, etc.) on biochar with a higher specific surface area are the decisive factors. The merits of reusing solid waste resource, namely excellent selectivity, easy separation, and simple preparation make the MBC a promising candidate of Pb(II) purifier.

A Bifunctional BiOBr/ZIF-8/ZnO Photocatalyst with Rich Oxygen Vacancy for Enhanced Wastewater Treatment and H2O2 Generation.

Photocatalytic technology is considered an ideal approach for clean energy conversion and environmental pollution applications. In this work, a bifunctional BiOBr/ZIF-8/ZnO photocatalyst was proposed for removing phenols in wastewater and generating hydrogen peroxide. Insights from scanning electron microscopy measurements revealed the well-dispersion of ZIF-8/ZnO was on the BiOBr layer, which could effectively prevent agglomeration of ZIF-8 and facilitate the separation of carriers. In addition, the optimal H2O2 yield of the BiOBr/ZIF-8/ZnO sample could reach 116 mmol·L-1·g-1 within 2 h, much higher than that of pure BiOBr (with the value of 82 mmol·L-1·g-1). The optimal BiOBr/ZIF-8/ZnO sample could also remove 90% of the phenol or bisphenol A in 2 h, and its kinetic constants were 3.8 times and 2.3 times that of pure BiOBr, respectively. Based on the analysis of the various experimental characterizations, the photocatalytic mechanism of the S-scheme BiOBr/ZIF-8/ZnO composite for the degradation of phenolic pollutants and generation of H2O2 was proposed. The formation of the heterojunction and the oxygen vacancy work together to significantly improve its photocatalytic efficiency. In addition, the BiOBr/ZIF-8/ZnO catalyst has a certain impact on the degradation of phenol in actual wastewater, providing a way to effectively remove refractory pollutants and generate H2O2 in actual water.

Procyanidins Alleviated Cerebral Ischemia/Reperfusion Injury by Inhibiting Ferroptosis via the Nrf2/HO-1 Signaling Pathway.

Procyanidins (PCs), which are organic antioxidants, suppress oxidative stress, exhibit anti-apoptotic properties, and chelate metal ions. The potential defense mechanism of PCs against cerebral ischemia/reperfusion injury (CIRI) was investigated in this study. Pre-administration for 7 days of a PC enhanced nerve function and decreased cerebellar infarct volume in a mouse middle cerebral artery embolization paradigm. In addition, mitochondrial ferroptosis was enhanced, exhibited by mitochondrial shrinkage and roundness, increased membrane density, and reduced or absent ridges. The level of Fe2+ and lipid peroxidation that cause ferroptosis was significantly reduced by PC administration. According to the Western blot findings, PCs altered the expression of proteins associated with ferroptosis, promoting the expression of GPX4 and SLC7A11 while reducing the expression of TFR1, hence inhibiting ferroptosis. Moreover, the treatment of PCs markedly elevated the expression of HO-1 and Nuclear-Nrf2. The PCs' ability to prevent ferroptosis due to CIRI was decreased by the Nrf2 inhibitor ML385. Our findings showed that the protective effect of PCs may be achieved via activation of the Nrf2/HO-1 pathway and inhibiting ferroptosis. This study provides a new perspective on the treatment of CIRI with PCs.

Role of SPAK-NKCC1 signaling cascade in the choroid plexus blood-CSF barrier damage after stroke.

BACKGROUND: The mechanisms underlying dysfunction of choroid plexus (ChP) blood-cerebrospinal fluid (CSF) barrier and lymphocyte invasion in neuroinflammatory responses to stroke are not well understood. In this study, we investigated whether stroke damaged the blood-CSF barrier integrity due to dysregulation of major ChP ion transport system, Na+-K+-Cl- cotransporter 1 (NKCC1), and regulatory Ste20-related proline-alanine-rich kinase (SPAK). METHODS: Sham or ischemic stroke was induced in C57Bl/6J mice. Changes on the SPAK-NKCC1 complex and tight junction proteins (TJs) in the ChP were quantified by immunofluorescence staining and immunoblotting. Immune cell infiltration in the ChP was assessed by flow cytometry and immunostaining. Cultured ChP epithelium cells (CPECs) and cortical neurons were used to evaluate H2O2-mediated oxidative stress in stimulating the SPAK-NKCC1 complex and cellular damage. In vivo or in vitro pharmacological blockade of the ChP SPAK-NKCC1 cascade with SPAK inhibitor ZT-1a or NKCC1 inhibitor bumetanide were examined. RESULTS: Ischemic stroke stimulated activation of the CPECs apical membrane SPAK-NKCC1 complex, NF-κB, and MMP9, which was associated with loss of the blood-CSF barrier integrity and increased immune cell infiltration into the ChP. Oxidative stress directly activated the SPAK-NKCC1 pathway and resulted in apoptosis, neurodegeneration, and NKCC1-mediated ion influx. Pharmacological blockade of the SPAK-NKCC1 pathway protected the ChP barrier integrity, attenuated ChP immune cell infiltration or neuronal death. CONCLUSION: Stroke-induced pathological stimulation of the SPAK-NKCC1 cascade caused CPECs damage and disruption of TJs at the blood-CSF barrier. The ChP SPAK-NKCC1 complex emerged as a therapeutic target for attenuating ChP dysfunction and lymphocyte invasion after stroke.

Arsenic trioxide inhibits angiogenesis of hepatocellular carcinoma after insufficient radiofrequency ablation via blocking paracrine angiopoietin-1 and angiopoietin-2.

OBJECTIVES: Angiogenesis occurs during tumor progression of hepatocellular carcinoma (HCC) after insufficient radiofrequency ablation (RFA). Arsenic trioxide (ATO) shows promising therapeutic potential in advanced HCC. Whether ATO regulates angiogenesis and can be used to prevent tumor progression in HCC after insufficient RFA is still unknown. METHODS: Insufficient RFA was simulated using a water bath. MTT assay and tube formation assay were used to evaluate the effects of ATO on viability and proangiogenic abilities of SMMC7721 and HepG2 cells after insufficient RFA in vitro. The molecular changes with the treatment of ATO were evaluated through Western blot. An ectopic nude mice model was used to evaluate the effect of ATO on the tumor of SMMC7721 cells in vivo after insufficient RFA. RESULTS: In this study, HepG2 and SMMC7721 cells after insufficient RFA (named HepG2-H and SMMC7721-H, respectively) showed higher proliferation than the untreated cells and promoted tube formation of endothelial cells in a paracrine manner. ATO eliminated the difference in proliferation between untreated and RFA-treated cells and suppressed angiogenesis induced by HCC cells after insufficient RFA through the Ang-1 (angiopoietin-1)/Ang-2 (angiopoietin-2)/Tie2 pathway. Hif-1α overexpression abolished the inhibitory effect of ATO on angiogenesis in HCC after insufficient RFA. ATO inhibited tumor growth and angiogenesis in HCC after insufficient RFA. CONCLUSIONS: Our results demonstrate that ATO blocks the paracrine signaling of Ang-1 and Ang-2 by inhibiting p-Akt/Hif-1α and further suppresses the angiogenesis of HCC after insufficient RFA.

Dexmedetomidine exerts its protective effect on cerebral ischemia reperfusion injury in mice by inhibiting ferroptosis. / å³ç¾Žæ‰˜å’ªå®šé€šè¿‡æŠ‘åˆ¶é“æ­»äº¡å‘æŒ¥å¯¹å°é¼ è„‘ç¼ºè¡€å†çŒæ³¨æŸä¼¤çš„ä¿æŠ¤ä½œç”¨.

OBJECTIVES: Stroke is one of the major diseases that can threaten human life and health. The incidence of ischemic stroke accounts for more than 70% of stroke. The mechanism of ischemia reperfusion (IR) injury caused by ischemic stroke is extremely complex. In recent years, dexmedetomidine has been increasingly studied in anti-cerebral IR injury as a common clinical anesthetic adjunct, but its specific mechanism is not fully understood. Therefore, this study aims to explore the effects and mechanisms of dexmedetomidine on cerebral IR injury in mice. METHODS: The mouse middle cerebral artery occlusion (MCAO) model was prepared by modified suture method. Male ICR mice were randomly divided into a sham group, an IR group, an IR+D1 group (IR+administered 25 µg/kg dexmedetomidine), an IR+D2 group(IR+administered 50 µg/kg dexmedetomidine), an IR+D3 group (IR+administered 100 µg/kg dexmedetomidine), and an IR+D2+ML385 group (IR+administered 50 µg/kg dexmedetomidine and 30 mg/kg ML385). The neurologic behavior of mice was evaluated by Longa's five-point method. 2,3,5-triphenyltetrazolium chloride (TTC) staining was used to detect the percentage of cerebral infarct volume in mice. The protein expressions of nuclear factor erythroid 2-related factor 2 (Nrf2), transferrin receptor 1 (TFR1), glutathione peroxidase 4 (GPX4), and solute carrier family 7 member 11 (SLC7A11) in the cerebral tissues of mice were detected by Western blotting.Mitochondrial morphology was observed under the transmission electron microscope. The contents of MDA, Fe2+, and GSH in the cerebral tissues of mice were detected. RESULTS: Compared with the sham group, neurobehavioral scores, cerebral infarct volume, the contents of MDA and Fe2+, as well as the protein expression of TFR1 were significantly increased; the contents of GSH and the protein expression of SLC7A11 and GPX4 were significantly reduced (all P<0.05); mitochondria in cerebral tissue were wrinkled, cristae were reduced, and membrane density was increased in the IR group. Compared with the IR group, neurobehavioral scores, cerebral infarction volume, MDA and Fe2+ contents, as well as the protein expression of TFR1 were significantly reduced; the contents of GSH and the protein expression of SLC7A11 and GPX4 were significantly increased (all P<0.05); mitochondrial damage in cerebral tissue was significantly relieved with the pre-treatment of dexmedetomidine. Compared with the IR+D2 group, neurobehavioral scores, cerebral infarction volume, MDA and Fe2+ contents, as well as the protein expression of TFR1 were significantly increased; the contents of GSH and the protein expression of SLC7A11 and GPX4 were significantly reduced (all P<0.05);mitochondria reappeared significantly damaged with the ML385 on the basis of dexmedetomidine pre-treatment. CONCLUSIONS: The protective effect of dexmedetomidine on cerebral IR injury mice is related to its inhibition of ferroptosis, and the mechanism might be related to its regulation of Nrf2 expression.

In situ preparation of g-C3N4/polyaniline hybrid composites with enhanced visible-light photocatalytic performance.

The graphic carbon nitride/polyaniline (g-C3N4/PANI) hybrid composites were successfully synthesized by a facile in situ polymerization process under ice water bath. The photocatalytic activities of the g-C3N4/PANI composites were evaluated by using oxytetracycline (OTC) as model pollutants. The optimal g-C3N4/PANI composite (5%PANI: the g-C3N4/PANI hybrid with 5 wt.% of PANI) showed an enhancement degradation rate of 5-fold compared to that of conventional g-C3N4 under simulated-sunlight irradiation. In addition, the 5%PANI demonstrate significantly photocatalytic evolution H2 rate (163.2 µmol/(g⋅hr)) under the visible light irradiation. Furthermore, based on the results of optical performance and electrochemical testing, a possible mechanism was proposed, indicating that the incorporation of PANI into the traditional g-C3N4 can effectively tune the electronic structures, improve the photo-generated electrons-holes separation and enhance extensive absorption of visible light. Such a g-C3N4/PANI hybrid nanocomposites could be envisaged to possess great potentials in practical wastewater treatment and water splitting.

Activation of Src mediates acquired cisplatin resistance in human lung carcinoma cells.

Cisplatin (CDDP) is the most effective chemotherapeutic drug against lung carcinoma. However, the emergence of resistant clones has severely limited its clinical application. We found that the cisplatin-resistant lung carcinoma cell line A549/CDDP had increased levels of the phosphorylated gap junction protein Cx43 and SRC tyrosine kinase, and low levels of total Cx43 protein and reduced gap junction formation. The SRC kinase inhibitor PP2 increased the expression of total Cx43 protein and enhanced cisplatin sensitivity, indicating that activated SRC kinase induces chemoresistance by decrease total Cx43 level. Furthermore, Cx43 gene silencing in the drug-resistant cell lines abrogated the sensitizing effect of PP2. Taken together, targeting SRC kinase by PP2 reverses cisplatin resistance by upregulating Cx43 protein levels, indicating a novel pathway of cisplatin resistance that may be amenable to therapeutic intervention.

[Expressions of pannexin proteins in I-10 Leydig tumor cells and TM3 Leydig cells and their regulatory effect on the channel function in mice].

OBJECTIVE: 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. METHODS: 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. RESULTS: The expressions of Panx-1 (ï¼»289.5 ± 55.8ï¼½%) and Panx-2 (ï¼»264.5 ± 24.6ï¼½%) were significantly increased in the I-10 Leydig tumor cells as compared with those in the normal TM3 Leydig cells (both P < 0.05). FRET was remarkably reduced after treated with CBX (ï¼»87.5 ± 17.7ï¼½%) and PBN (ï¼»89.3 ± 14.3ï¼½%) in comparison with that in the control group (both P < 0.01). 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 (P < 0.01) and (61.7 ± 2.5)%, (35.8 ± 1.6)% and (13.5 ± 8.3)% in the PBN group (P < 0.01). 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 P < 0.01), but up-regulated that of Panx-1 by (128.4 ± 7.5)% in the mPanx-1 group (P < 0.01) as compared with the negative control. FRET was reduced by (72.4 ± 39.4)% in the shRNA group (P < 0.01) 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 (P < 0.01) while FRET elevated by (122.5 ± 17.1)% in the mPanx-1 group (P < 0.01) 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 (P < 0.01). CONCLUSIONS: 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.

[Protective effects of P2X7 receptor inhibition in cerebral ischemia/reperfusion injury in rats].

OBJECTIVE: To investigate the protective effects of P2X7 receptor (P2X7R) inhibitor against cerebral ischemia/reperfusion (I/R) injury in rats and the possible mechanisms.
 Methods: The neurological deficit of rats was evaluated by Longa score. The infarct volume was examined by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. The expression levels of extracellular signal-regulated kinase (ERK), phosphorylation extracellular signal-regulated kinas p-ERK), connexin 43 (Cx43), Bax, Bcl-2 and cleaved caspase-3 were detected by Western blot.
 Results: Compared with sham group, the neurobehavioral score (P<0.05) and cerebral infarct volume (P<0.01) of rats in I/R group was increased. Compared with I/R group, brilliant blue G (BBG, the antagonist of P2X7R) or PD98059 (the inhibitor of EKR kinase) could reduce the neurobehavioral score (P<0.01) and cerebral infarct volume significantly (P<0.05). The neurobehavioral score and cerebral infarct volume was further decreased (P<0.05) when rats were treated with both BBG and PD98059. Compared with I/R group, the expression levels of p-ERK, Cx43, cleaved caspase-3 and the ratio of Bax/Bcl-2 were decreased by BBG or PD98059 pretreatment, and the protective effects were further enhanced when rats were treated with both BBG and PD98059 (P<0.05).
 Conclusion: Inhibition of P2X7R reduces the cerebral I/R injury of rats. ERK inhibition is probably involved in the protective effects of P2X7R inhibitor against cerebral I/R injury, which may be related to the reduction of Cx43 and cleaved caspase-3, and the ratio of Bax/Bcl-2.

Oxidized low-density lipoprotein-induced microparticles promote endothelial monocyte adhesion via intercellular adhesion molecule 1.

Oxidized low-density lipoprotein (oxLDL) accumulates early in atherosclerotic lesions and plays an important role in the progressive formation of atherosclerotic plaques. Endothelial derived microparticles (EMPs) form a heterogeneous population of <1-µm particles that shed from endothelial membranes upon activation. While EMPs are shown to be involved in atherosclerotic pathophysiology and progression, there is no report regarding the relationship between oxLDL and EMPs. In this study, we aim to determine the influence of oxLDL on endothelial microparticle release and the subsequent regulation of the endothelial activation. EMPs were collected from the medium of human umbilical vein endothelial cells (HUVECs) treated with oxLDL or PBS as control. We find that oxLDL increases the release of EMPs containing intercellular adhesion molecule 1 (ICAM-1) but not vascular cell adhesion molecule 1 (VCAM-1). Confocal microscopy analysis further demonstrates that these EMPs interact with endothelial cells and increase the expression of ICAM-1 in HUVECs. The fact that injecting oxLDL-induced EMPs via the tail vein of ICR mice augments ICAM-1 expression on aortic endothelial cells confirms our results in vivo. Finally, oxLDL-induced EMPs from HUVECs increase the adhesion of monocytes to endothelial cells as determined by the adhesion assay. Our study suggests that oxLDL may augment the release of EMPs harboring increased levels of ICAM-1 that can be transferred to endothelial cells elsewhere. This leads to increased monocyte recruitment in other regions where oxLDL accumulation was initially more limited. EMPs may therefore serve as the mediator that propagates oxLDL-induced endothelial inflammation.

A novel anti-inflammatory mechanism of high density lipoprotein through up-regulating annexin A1 in vascular endothelial cells.

High density lipoprotein (HDL) as well as annexin A1 have been reported to be associated with cardiovascular protection. However, the correlation between HDL and annexin A1 was still unknown. In this study, HDL increased endothelial annexin A1 and prevented the decrease of annexin A1 in TNF-α-activated endothelial cells in vitro and in vivo, and above effects were attenuated after knockdown of annexin A1. Annexin A1 modulation affected HDL-mediated inhibition of monocyte adhesion to TNF-α-activated endothelium (45.2±13.7% decrease for annexin A1 RNA interference; 78.7±16.3% decrease for anti-Annexin A1 antibody blocking; 11.2±6.9% increase for Ad-ANXA1 transfection). Additionally, HDL up-regulated annexin A1 through scavenger receptor class B type I, involving ERK, p38MAPK, Akt and PKC signaling pathways, and respective inhibitors of these pathways attenuated HDL-induced annexin A1 expression as well as impaired HDL-mediated inhibition of monocyte-endothelial cell adhesion. Apolipoprotein AI also increased annexin A1 and activated similar signaling pathways. Endothelial annexin A1 from apolipoprotein AI knockout mice was decreased in comparison to that from wild type mice. Finally, HDL-induced annexin A1 inhibited cell surface VCAM-1, ICAM-1 and E-selectin, and secretion of MCP-1, IL-8, VCAM-1 and E-selectin, thereby inhibiting monocyte adhesion.

Metformin exhibits the anti-proliferation and anti-invasion effects in hepatocellular carcinoma cells after insufficient radiofrequency ablation.

BACKGROUND: The mechanisms and prevention of progression of hepatocellular carcinoma (HCC) after insufficient radiofrequency ablation (RFA) has been preliminarily investigated, therefore, new strategy needs to be investigated to prevent the process. Whether metformin could be used to inhibit the growth of HCC after insufficient RFA and further prevent the progression of residual HCC remains unclearly. METHODS: MTT assay, colony formation assay and transwell assay were used to observe the cell viability, migration and invasion. Western blot and immunohistochemistry methods were used to observe the expression of proteins. Xenograft model was used to evaluate the growth of HCC cells in vivo. RESULTS: Metformin inhibited the enhanced proliferation, migration and invasion of HepG2 and SMMC7721 cells after insufficient RFA (named as HepG2-H and SMMC7721-H). Metformin deregulated the expression of p-Akt in HepG2 and SMMC7721 cells after insufficient RFA through AMPK/PTEN pathway. HepG2-H cells also exhibited larger tumor size in vivo. Higher expression of Ki-67 and CD31 and lower expression of E-cadherin were observed in HepG2-H tumors. Metformin blocked the enhanced growth of HepG2 cells in vivo after insufficient RFA. Metformin had no apparent toxicity on nude mice. CONCLUSIONS: Metfromin inhibited the growth of HCC cells after insufficient RFA, and may be used to prevent the progression of HCC after RFA.

Sorafenib suppresses the epithelial-mesenchymal transition of hepatocellular carcinoma cells after insufficient radiofrequency ablation.

BACKGROUND: Epithelial-mesenchymal transition (EMT) played an important role in the progression of hepatocellular carcinoma (HCC) after insufficient radiofrequency ablation (RFA). However, whether sorafenib could be used to suppress the EMT of HCC after insufficient RFA and further prevent the progression of residual HCC remains poorly unknown. METHODS: Insufficient RFA was simulated using a water bath (47 °C 5, 10, 15, 20 and 25 min gradually). MTT assay and transwell assay were used to evaluate the effects of sorafenib on viability, migration and invasion of HepG2 and SMMC7721 cells after insufficient RFA in vitro. After insufficient RFA, the molecular changes in HCC cells with the treatment of sorafeinb were evaluated using western blot and ELISAs. An ectopic nude mice model was used to evaluate the effect of sorafenib on the growth of HepG2 cells in vivo after insufficient RFA. RESULTS: HepG2 and SMMC7721 cells after insufficient RFA (named as HepG2-H and SMMC7721-H) exhibited enhanced viability, migration and invasion in vitro. Sorafenib inhibited the enhanced viability, migration and invasion of HepG2 and SMMC7721 cells after insufficient RFA. Molecular changes of EMT were observed in HepG2-H and SMMC7721-H cells. Sorafenib inhibited the EMT of HepG2-H and SMMC7721-H cells. HepG2-H cells also exhibited larger tumor size in vivo. Higher expression of PCNA, Ki67, N-cadherin, MMP-2 and MMP-9, was also observed in HepG2-H tumors. Sorafenib blocked the enhanced growth of HepG2 cells in vivo after insufficient RFA. CONCLUSIONS: Sorafenib inhibited the EMT of HCC cells after insufficient RFA, and may be used to prevent the progression of HCC after RFA.

[Inhibition of gap junctional intercellular communication protects astrocytes from hypoxia/reoxygenation injury].

OBJECTIVE: To investigate the effects of inhibiting gap junctional intercellular communication on hypoxia/reoxygenation injury in astrocytes. METHODS: 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. RESULTS: Compared with the normal control group, the gap junctional function of astrocytes was increased significantly in ischemia/reperfusion group (P<0.01), the surviving fraction of astrocytes decreased significantly (P<0.01) and its cell apoptosis ratio increased significantly (P<0.01). Compared with the ischemia/reperfusion group, the gap junctional function of astrocytes in18-α-glycyrrhetinic acid and oleamide group decreased significantly (P<0.01), the viability of astrocytes increased significantly (P<0.01), while cell apoptosis decreased significantly (P<0.01). CONCLUSION: Inhibition of intercellular gap junction has protective effect against hypoxia/reoxygenation injury in astrocytes.

[Baicalein enhances the gap junction in the TM4 Sertoli cells of mice].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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 (P < 0.01). Western blot and immunofluorescence assay showed that 0-20 µmol/L baicalein remarkably elevated the expression of Cx43 in the TM4 cells (P < 0.01) and on the membrane of the TM4 cells. CONCLUSION: 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.

YC-1 enhances the anti-tumor activity of sorafenib through inhibition of signal transducer and activator of transcription 3 (STAT3) in hepatocellular carcinoma.

BACKGROUND: Traditional systemic chemotherapy does not provide survival benefits in patients with hepatocellular carcinoma (HCC). Molecular targeted therapy shows promise for HCC treatment, however, the duration of effectiveness for targeted therapies is finite and combination therapies offer the potential for improved effectiveness. METHODS: Sorafenib, a multikinase inhibitor, and YC-1, a soluble guanylyl cyclase (sGC) activator, were tested in HCC by proliferation assay, cell cycle analysis and western blot in vitro and orthotopic and ectopic HCC models in vivo. RESULTS: In vitro, combination of sorafenib and YC-1 synergistically inhibited proliferation and colony formation of HepG2, BEL-7402 and HCCLM3 cells. The combination also induced S cell cycle arrest and apoptosis, as observed by activated PARP and caspase 8. Sorafenib and YC-1 respectively suppressed the expression of phosphorylated STAT3 (p-STAT3) (Y705) in a dose- and time-dependent manner. Combination of sorafenib and YC-1 significantly inhibited the expression of p-STAT3 (Y705) (S727), p-ERK1/2, cyclin D1 and survivin and SHP-1 activity compared with sorafenib or YC-1 used alone in all tested HCC cell lines. In vivo, sorafenib-YC-1 combination significantly suppressed the growth of HepG2 tumor xenografts with decreased cell proliferation and increased apoptosis observed by PCNA and PARP. Similar results were also confirmed in a HCCLM3 orthotopic model. There was a reduction in CD31-positive blood vessels and reduced VEGF expression, which suggested a combinational effect of sorafenib and YC-1 on angiogenesis. The reduced expression of p-STAT3, cyclin D1 and survivin was also observed with the combination of sorafenib and YC-1. CONCLUSIONS: Our data show that sorafenib-YC-1 combination is a novel potent therapeutic agent that can target the STAT3 signaling pathway to inhibit HCC tumor growth.