A molecularly imprinted ratiometric fluorescent sensor for visual detection of 1-naphthol based on fluorescence-enhanced CdTeS QDs via APTES modification.

CdTeS quantum dots (CdTeS QDs) were synthesized using the hydrothermal method and subsequently modified with (3-aminopropyl)triethoxysilane (APTES). This modification resulted in a significant enhancement of the fluorescence intensity, which was observed to be five times stronger than that of unmodified CdTeS QDs at 597 nm. Only after the fluorescence enhancement by APTES modification, the material showed a response to 1-naphthol (1-NP). Based on this, the molecularly imprinted polymers (MIPs) with ratiometric fluorescence were developed for the detection of 1-NP, that is, the synthetic raw material and the metabolite of the pesticide carbaryl. Under the excitation of 365 nm UV, the bright orange-red fluorescence (597 nm) of CdTeS QDs encapsulated in MIPs was quenched by 1-NP in the suspension, and 1-NP showed a gradually increasing blue emission (460 nm) with the increase of its concentration. This sensor has a good linear relationship between fluorescence intensity ratio (F460/F597) and 1-NP concentration (C1-NP) in a large concentration range (6.0-140.0 µM, LOD=0.45 µM, RSD<4.41%). It exhibits a visible fluorescence change from orange-red to blue-purple. Excellent recoveries in real samples were obtained by simulating carbaryl metabolism and demonstrated its potential in detection of 1-NP and carbaryl.

Carbonized titanium dioxide with good adsorption properties for cationic dyes via simple heat treatment.

With the development of modern industry, the discharge of dye wastewater is increasing year by year, and the damage caused by this wastewater to the ecosystem is often irreversible. Therefore, the research on the harmless treatment of dyes has attracted much attention in recent years. In this paper, commercial titanium dioxide (anatase nanometer titanium dioxide) was heat treated with anhydrous ethanol to synthesize titanium carbide (C/TiO2). Its maximum adsorption capacity for cationic dyes methylene blue (MB) and Rhodamine B is 27.3 and 124.6 mg g-1, respectively, which is much higher than that of pure TiO2. The adsorption kinetics and isotherm model of C/TiO2 were studied and characterized by Brunauer-Emmett-Teller, x-ray photoelectron spectroscopy, x-ray diffraction, Fourier transform infrared spectroscopy, and other methods. The results show that the carbon layer on the surface of C/TiO2 promotes the increase in surface hydroxyl groups, which is the main reason for the increase in MB adsorption. Compared with other adsorbents, C/TiO2 showed excellent reusability. The experimental results of adsorbent regeneration showed that the adsorption rate R% of MB was almost unchanged after three cycles. During the recovery of C/TiO2, the dyes adsorbed on its surface are removed, which solves the problem that the adsorbent cannot degrade dyes simply by adsorption. Additionally, C/TiO2 has a stable adsorption effect, is insensitive to the pH value, has a simple preparation process, and has relatively low raw material prices, making it suitable for large-scale operation. Therefore, it has good commercial prospects in the organic dye industry wastewater treatment.

[Angiotensin (1-7) inhibits angiotensin II-stimulated expression of connective tissue growth factor mRNA in hepatic stellate cells].

To explore the angiotensin peptide [Ang (1-7)]-mediated inhibition of Ang II in human hepatic stellate cells (HSCs) and determine the involvement of the ACE2-Ang (1-7)-Mas axis. The human HSC line, LX2, was used in all experiments, and divided into control (unstimulated) and Ang II-stimulated (10-6 mol/L) groups. The Ang II-stimulated cells were further divided among several pre-treatment (prior to Ang II) groups: ROCK-inhibited (Y27632 blocking agent, 10-6 mol/L); irbesartan-inhibited (AT-1 receptor antagonist, 10-6 mol/L); and Mas receptor-inhibited (A779 Mas receptor antagonist, 10-6 mol/L). To explore the potential inhibitory effects of various Ang family members, the Ang II-stimulated and pre-treated LX2 cells were exposed to Ang (1-7) (10-6 mol/L) for 24 h. Western blot, reverse transcription-polymerase chain reaction (RT-PCR), and QuantiGene assay were used to assess changes in protein and mRNA expression levels of RhoA, ROCK, and connective tissue growth factor (CTGF). Compared with the control group, Ang II-stimulated cells showed significantly increased levels of RhoA protein (0.337+/-0.074 vs. 0.870+/-0.093), ROCK2 mRNA (0.747+/-0.061 vs. 0.368+/-0.023), and CTGF mRNA (0.262+/-0.007 vs. 0.578+/-0.028) (all, P less than 0.01). Pre-treatment with irbesartan or Y27632 eliminated these responses. Ang (1-7) inhibited the Ang II-stimulated up-regulation of RhoA, ROCK, and CTGF. Ang (1-7) can inhibit the Ang II-stimulated up-regulation of RhoA, ROCK and CTGF in hepatic stellate cells, indicating that the ACE2-Ang (1-7)-Mas axis, an important branch of the renin-Ang-aldosterone system is involved in the occurrence and development of liver fibrosis.

The role of translationally controlled tumor protein in tumor growth and metastasis of colon adenocarcinoma cells.

Translationally controlled tumor protein (TCTP) plays a major role in a broad array of biological processes. However, the TCTP-related biological process and interactive proteins still remain poorly characterized. In the present study, we found that knockdown of TCTP inhibited proliferation, migration, and invasion activities of LoVo cells in vitro and in vivo. The whole-cell proteomes were compared by 2D gel electrophoresis before and after knockdown of TCTP. Alterations in 27 proteins were detected and their identities were revealed by mass spectrometry analysis. Components of Ubiquitin-Proteasome System, proteins involved in the cytoskeleton biosynthesis and tumor metastasis were found to be changed upon TCTP removal. These results imply that TCTP might play at least a partial role in colon adenocarcinoma progression.

Upregulation of angiotensin-converting enzyme (ACE) 2 in hepatic fibrosis by ACE inhibitors.

1. The role of angiotensin-converting enzyme (ACE) 2 is likely to balance the status of the renin-angiotensin system (RAS) by degrading angiotensin (Ang) II and generating Ang-(1-7). Earlier demonstrations that ACE2 is insensitive to ACE inhibitors prompted us to evaluate the effect of ACE inhibitors on ACE2 expression. 2. Liver fibrosis was induced in rats with 40% CCl(4) (2.5 mL/kg, s.c., twice per week). Half the rats were further treated with perindopril (2 mg/kg, p.o., daily). After 2 and 4 weeks treatment, ACE2 immunoreactivity was assessed by immunohistochemical staining, ACE2 protein expression was determined by western blot and mRNA expression of ACE2 and the Ang-(1-7) receptor Mas was determined by reverse transcription-polymerase chain reaction (RT-PCR). 3. As an in vitro study, hepatic stellate cells (HSC) were treated with AngII (0.1-10 micromol/L) alone or in combination with the synthesized peptide ACEI (Sigma-Aldrich). Western blot and RT-PCR were used to evaluate ACE2 expression and Mas mRNA levels. Furthermore, after treatment of HSC with the Mas antagonist A779 (1 micromol/L), the protein expression of connective tissue growth factor (CTGF) was detected to evaluate the interaction between AngII, ACEI and the ACE2-Mas axis. 4. Expression of both ACE2 mRNA and protein and Mas mRNA was markedly upregulated in both CCl(4)-injured rat liver and AngII-treated HSC. Further significant upregulation was observed following additional administration of ACEI. In addition, ACEI treatment of HSC inhibited AngII-induced overexpression of connective tissue growth factor and this effect was ameliorated by blockade of the Mas receptor with A779. 5. The findings of the present study suggest that ACE inhibitors are able to upregulate ACE2 under conditions of liver injury both in vivo and in vitro, which may indicate potential benefits of ACE inhibitors in the therapeutic treatment of liver fibrosis.

NLRP3 inflammasomes in macrophages drive colorectal cancer metastasis to the liver.

Inflammation and immunity are important determinants of cancer initiation, promotion, and progression to cancer equilibrium or suppression. The NOD-like receptor family pyrin domain containing 3 (NLRP3) is an oligomeric intracellular immune receptor, and the main component of inflammasome. As a widely distributed effector of innate immunity, NLRP3 inflammasome affects development of many cancer types, but its exact role in colorectal cancer (CRC) is controversial. We found that cells with the macrophage (MΦ) marker CD68 and strong NLRP3 expression densely surrounded CRC tissue. The NLRP3 inflammasome was activated in MΦs by MΦ-CRC cell crosstalk; it resulted in faster migration of CRC cells, whereas blocking NLRP3 signaling suppressed CRC cell migration in vitro, and metastatic ability in vivo. NLRP3 signaling activation in MΦs can contribute to CRC cell migration and invasion.

[Role of Rho-Rock pathways induced by angiotensin II in hepatic stellate cell contraction].

OBJECTIVE: To investigate the mechanism of Ca(2+)-independent pathways mediated by Rho-kinase in contraction of hepatic stellate cells (HSCs) induced by angiotonin II (Ang II). METHODS: Human HSCs of the line HSC-T6 were cultured and randomly divided into 6 groups: negative control group, Ang II group treated by Ang II10 micromol/L for 15 min, Ang II + irbesartan (Ang II receptor inhibitor) group, exposed to irbesartan for 60 min prior to Ang II treatment, Ang II + Y27632 (Rho kinase specific inhibitor) exposed to Y27632 for 60 min prior to Ang II treatment, Ang II + ML-7 (myosin light chain kinase specific inhibitor) + saturo (protein kinase C specific inhibitor) group exposed to stauro for 60 min prior to Ang II treatment, and Ang II + Y27632 + ML-7 + stauro group, exposed to Y27632 and stauro for 60 min prior to Ang II treatment. The cell contraction was detected by silicone-rubber-membrane cultivation directly. The protein levels of MLC and phosphorylated MLC were detected by Western blotting 5, 15, 30, 60, and 120 min after Ang II treatment. RT-PCR was used to detect the expression of Rock2, RhoAGTP, and RhoGEF in Ca(2+)-independent pathways mediated by Rho-kinase. RESULTS: The silicone-rubber-membrane covered by Ang II treated HSCs showed obvious wrinkles indicating the contraction of HSCs. The ratios of phosphorylated MLC protein at the time pints 5, 15, 30, 60, and 120 min of the Ang II group to the control group (0 min) were 11.7 +/- 0.1, 26.9 +/- 0.1, 11.2 +/- 0.1, 4.1 +/- 0.1, and 1.0 +/- 0.1, showing that Ang II increased the phosphorylated MLC protein level time-dependently with the peak level at the time point of 15 minutes. The levels of phosphorylated MLC protein of the Ang II + irbesartan and Ang II + Y27632 groups were (1.12 +/- 0.09)and (1.22 +/- 0.10) respectively, both significantly lower than that of the Ang II group (1.33 +/- 0.06, both P < 0.01). The level of phosphorylated MLC protein of the Ang I + ML-7 + stauro group was (1.43 +/- 0.09), significantly higher than that of the Ang II + Y27632 group (0.64 +/- 0.04, P < 0. 01). The level of phosphorylated MLC protein of the Ang II + Y27632 + ML-7 + stauro group was (0.64 +/- 0.04), significantly lower than that of the Ang II group (P = 0. 003). The mRNA expression levels of Rock2, RhoAGTP, and RhoGEF of the Ang II group were (0.36 +/- 0.01), (0.80 +/- 0.01), and(0.65 +/- 0.11)respectively, all significantly higher than those of the control group [(0.12 +/- 0.01), (0.40 +/- 0.02), and (0.33 +/- 0.09) respectively, all P = 0. 000], and the mRNA expression levels of Rock2, RhoAGTP, and RhoGEF of the Ang II + irbesartan + group were (0.21 +/- 0.02), (0.62 +/- 0.02), and (0.41 +/- 0.10) respectively, all significantly lower than those of the control group. The mRNA expression levels of Rock2 (0.15 +/- 0.01) and RhoGEF (0.28 +/- 0.08) were lower, but The mRNA expression level of RhoAGTP (1.14 +/- 0.02) was higher in the Ang II + Y27632 group. The mRNA expression levels of Rock2, RhoAGTP, and RhoGEF of the Ang II + ML-7 + stauro group were (0.22 +/- 0.01), (0.55 +/- 0.03), and (0.44 +/- 0.10) respectively, all significantly higher than those of the control group. The mRNA expression levels of Rock2, RhoAGTP, and RhoGEF of the Ang II + Y27632 + ML-7 + stauro group were (0.23 +/- 0.01), (0.83 +/- 0.02), and (0.69 +/- 0.08) respectively, all significantly higher than those of the Ang II + ML-7 + stauro group. CONCLUSION: Ang II induces HSCs contraction in Ca(2+)-independent pathways mediated by Rho-kinase.

Translationally controlled tumor protein affects colorectal cancer metastasis through the high mobility group box 1-dependent pathway.

Recently, accumulating evidence from clinical and experimental researches have suggested that translationally controlled tumor protein (TCTP) and high mobility group box 1 (HMGB1) are implicated in colorectal cancer (CRC) metastasis. However, whether there is an interconnection between these two tumor-promoting proteins and how they affect CRC metastasis remain to be fully elucidated. In the present study, the expression level of TCTP in CRC tissues was assessed by immunohistochemical staining and immunoblotting, and the serum concentration of HMGB1 in patients with CRC was detected by enzyme-linked immunosorbent assay. In vitro, following the modulation of TCTP expression in colon cancer LoVo cells, the translocation behavior of HMGB1 was observed by immunofluorescence assay. Furthermore, the activity of nuclear factor-κB (NF-κB) in LoVo cells was evaluated by immunoblotting and luciferase assay, and the invasion ability of LoVo cells after different treatments was determined using cell invasion assay. In vivo, xenograft tumor model was established and the correlation of TCTP and HMGB1 expression in xenografted tumors was studied by immunohistochemical examination. The results revealed that the expression level of TCTP in CRC tissue and the serum concentration of HMGB1 in patients with CRC were significantly increased, and there was a strong positive correlation between them. In vitro experiments showed that the overexpression of TCTP on LoVo cells resulted in the release of HMGB1 from the nucleus to the cytoplasm and into the extracellular space. In addition, the overexpression of TCTP led to the activation of NF-κB in LoVo cells, and this effect was reversed by treatment with antibodies targeting HMGB1 or to its receptors Toll-like receptor 4 (TLR4) and receptor for advanced glycation end products advanced glycation end products (RAGE). Furthermore, inhibition of the HMGB1-TLR4/RAGE-NF-κB pathway significantly inhibited the TCTP-stimulated invasion of LoVo cells. In vivo experiments demonstrated that the overexpression of TCTP in nude mice promoted the development and spread of xenografted tumors, and concurrently enhanced the expression of HMGB1 in tumor tissues. Collectively, these findings suggested that TCTP promotes CRC metastasis through regulating the behaviors of HMGB1 and the downstream activation of the NF-κB signaling pathway.

[A preliminary investigation of nuclear factor kappa B in peripheral blood lymphocytes of patients with hepatitis B].

OBJECTIVE: To explore the activity of nuclear factor kappa B (NF-kappaB) in peripheral blood lymphocytes (PBL) of patients with hepatitis B. METHODS: The PBL of patients with different types of hepatitis B and healthy individuals were isolated and then the nuclear extract was prepared. Assessment of NF-kappaB DNA binding activity was performed by electrophoretic mobility shift assay (EMSA) using digoxin labeled double-stranded oligonucleotide containing kappa B consensus sequence. RESULTS: Densitometric scanning of the EMSA bands showed that the mean optical densities (A) from the groups of normal control, acute hepatitis B, chronic hepatitis B and chronic severe hepatitis B were 20.18+/-2.16, 27.75+/-4.11, 13.90+/-3.20 and 8.02+/-2.65 respectively. Analysis of variance showed the F value was 26.112 and the difference among the groups was significant. The difference between two groups with Dunnett T3 analysis showed there are statistically difference between the groups of the normal group and the chronic severe hepatitis B group, the acute hepatitis B group and the chronic hepatitis B group, and the acute hepatitis B group and the chronic severe hepatitis B. CONCLUSION: The activity of NF-kappaB in PBL of patients with hepatitis B is related with the different outcomes of hepatitis B virus (HBV) infection. Decreased activity of NF-kappaB may be an important cause for the dysfunction of PBL in chronic HBV-infected patients.

[Effect of angiotensin1-7 on alpha-smooth muscle actin protein expression in rat hepatic stellate cells].

OBJECTIVE: To investigate the effect of angiotensin II and angiotensin1-7 on alpha-smooth muscle actin (alpha-SMA)-induced Ca(2+)-independent pathways mediated by Rho kinase2 in hepatic stellate cells (HSCs). METHODS: HSC-T6 cells were treated with 10 micromol/L of AngII, Ang1-7, AngII +Ang1-7, and Ang1-7+A779. RT-PCR was used to detect the expression of Rho kinase2 (Rock2) in Ca(2+)-independent pathways, and alpha-SMA protein expression was detected by Western blotting. RESULTS: The mRNA expression of Rock2 increased significantly in the cells after AngII treatment (P<0.01), but decreased following Ang1-7 treatment. Ang1-7 treatment significantly reduced alpha-SMA level in AngII-induced cells (P<0.01). CONCLUSION: Ang1-7 can inhibit AngII-induced activation of Rock2 and reduce alpha-SMA expression in HSCs.

[Angiotensin II stimulates platelet-derived growth factor-B expression in hepatic stellate cells by activating EGR-1].

OBJECTIVE: To investigate the signal transduction mechanism underlying the effects of angiotensin II (AngII) on extracellular signal-regulated kinase 1/2 (ERK1/2), early growth response-1 (EGR-1) and platelet-derived growth factor-B (PDGF-B) in hepatic stellate cells (HSCs). METHODS: HSC-T6 cells treated with AngII for 10 or 30 min were examined for phospho-P42/44 protein expression using Western blotting. In another experiment, the cells were preincubated for 1 h in the presence of U0126 (an inhibitor of the MAPK/ERK kinase), irbesartan (an AT-1 receptor blocker), or antioxidant-N-acetylcysteine (NAC) prior to AngII exposure, and the protein expression of phospho-P42/44 and PDGF-B were measured with Western blotting. The DNA binding activity of EGR-1 was analyzed using electrophoretic gel mobility shift assay (EMSA), and the expression of PDGF-B was detected immunohistochemically. RESULTS: AngII induced phospho-P42/44 expression in HSC-T6, which was abrogated by U0126 or irbesartan. NAC did not inhibit phospho-P42/44 expression. EMSA showed that AngII exposure of the HSC cells markedly increased EGR-1 DNA binding activity, reaching the maximum after 60 min of exposure followed by progressive declination; irbesartan and U0126 significantly suppressed AngII-induced EGR-1 activity enhancement. ACEI at 1 micromol/L and 10 nmol/L inhibited EGR-1 activity, but ACEI at the concentration of 0.1 nmol/L resulted in enhanced EGR-1 activity. NAC showed no obvious effect in suppressing EGR-1 activity. AngII increased PDGF-B protein level in the HSCs, the effect of which was inhibited by irbesartan. U0126, NAC and ACEI did not attenuate PDGF-BB protein level in the HSCs. CONCLUSION: Stimulation of the HSCs with AngII results in EGR-1 activation via the ERK1/2 pathway, leading to up-regulation of PDGF-B expression.

[Effect of angiotensin II on Rho-Rock pathway in rat hepatic stellate cell contraction].

OBJECTIVE: To investigate the mechanisms of angiotonin II (AngII)-induced Ca(2+)-independent pathways mediated by Rho kinase in hepatic stellate cells (HSCs). METHODS: HSC-T6 cells were treated with 1 micromol/L of AngII, and the subsequent cell contraction was directly observed with silicone rubber membrane culture method. The cells with 10 micromol/L AngII treatment were examined for myosin light chain (MLC) phosphorylation level using Western blotting, and the effects of irbesartan (a specific inhibitor of AngII 1- receptor) and Y27632 (a Rho kinase inhibitor) on AngII-induced MLC phosphorylation were evaluated. RT-PCR was used to detect the expression of Rock2 in Ca(2+)- independent pathways mediated by Rho kinase. RESULTS: AngII induced HSC contraction and time-dependent MLC phosphorylation changes, which peaked 15 min after the treatment followed by gradual reduction. Irbesartan or Y27632 treatment significantly lowered MLC phosphorylation level in AngII-induced cells (P<0.01). The mRNA expression of Rock2 increased significantly after AngII treatment (P<0.01), but decreased following subsequent irbesartan or Y27632 treatment. CONCLUSION: AngII induces HSC contraction through Ca(2+)-independent pathways mediated by Rho kinase.