Interleukin (IL)-1 Receptor Signaling Is Required for Complete Taste Bud Regeneration and the Recovery of Neural Taste Responses following Axotomy.

Experimental or traumatic nerve injury causes the degeneration of associated taste buds. Unlike most sensory systems, the sectioned nerve and associated taste buds can then regenerate, restoring neural responses to tastants. It was previously unknown whether injury-induced immune factors mediate this process. The proinflammatory cytokines, interleukin (IL)-1α and IL-1ß, and their requisite receptor are strongly expressed by anterior taste buds innervated by the chorda tympani nerve. We tested taste bud regeneration and functional recovery in mice lacking the IL-1 receptor. After axotomy, the chorda tympani nerve regenerated but was initially unresponsive to tastants in both WT and Il1r KO mice. In the absence of Il1r signaling, however, neural taste responses remained minimal even >8 weeks after injury in both male and female mice, whereas normal taste function recovered by 3 weeks in WT mice. Failed recovery was because of a 57.8% decrease in regenerated taste buds in Il1r KO compared with WT axotomized mice. Il1a gene expression was chronically dysregulated, and the subset of regenerated taste buds were reinnervated more slowly and never reached full volume as progenitor cell proliferation lagged in KO mice. Il1r signaling is thus required for complete taste bud regeneration and the recovery of normal taste transmission, likely by impairing taste progenitor cell proliferation. This is the first identification of a cytokine response that promotes taste recovery. The remarkable plasticity of the taste system makes it ideal for identifying injury-induced mechanisms mediating successful regeneration and recovery.SIGNIFICANCE STATEMENT Taste plays a critical role in nutrition and quality of life. The adult taste system is highly plastic and able to regenerate following the disappearance of most taste buds after experimental nerve injury. Several growth factors needed for taste bud regeneration have been identified, but we demonstrate the first cytokine pathway required for the recovery of taste function. In the absence of IL-1 cytokine signaling, taste bud regeneration is incomplete, preventing the transmission of taste activity to the brain. These results open a new direction in revealing injury-specific mechanisms that could be harnessed to promote the recovery of taste perception after trauma or disease.

Proteins Secreted by Lung Cancer Cells Induce the Onset of Proteinuria via Focal Adhesion Kinase Signaling in Mice.

Paraneoplastic nephrotic syndrome (PNS) is a complication seen in cancer patients. Ultrastructural examination shows the accumulation of proteins and the presence of foot process (FP) effacement in the glomeruli of PNS patients. Previously, we reported that orthotopic xenografts of Lewis lung carcinoma 1 in C57BL/6 mice caused them to develop lung cancer with albuminuria. This implies that these mice can be used as a model of human disease and suggests that Lewis lung carcinoma 1 cell-secreted proteins (LCSePs) contain nephrotoxic molecules and cause inflammation in renal cells. As podocyte effacement was present in glomeruli in this model, such podocyte injury may be attributable to either soluble LCSeP or LCSeP deposits triggering pathological progression. LCSePs in conditioned media was concentrated for nephrotoxicity testing. Integrin-focal adhesion kinase (FAK) signaling and inflammatory responses were evaluated in podocytes either exposed to soluble LCSePs or seeded onto substrates with immobilized LCSePs. FAK phosphorylation and interleukin-6 expression were higher in podocytes attached to LCSePs substrates than in those exposed to soluble LCSePs. Notably, LCSeP-based haptotaxis gave rise to altered signaling in podocytes. When podocytes were stimulated by immobilized LCSePs, FAK accumulated at focal adhesions, synaptopodin dissociated from F-actin, and disrupting the interactions between synaptopodin and α-actinin was observed. When FAK was inhibited by PF-573228 in immobilized LCSePs, the association between synaptopodin and α-actinin was observed in the podocytes. The association of synaptopodin and α-actinin with F-actin allowed FP stretching, establishing a functional glomerular filtration barrier. Therefore, in this mouse model of lung cancer, FAK signaling prompts podocyte FP effacement and proteinuria, indicative of PNS.

Coordination of LMO7 with FAK Signaling Sustains Epithelial Integrity in Renal Epithelia Exposed to Osmotic Pressure.

The kidney epithelial barrier has multifaceted functions in body fluids, electrolyte homeostasis, and urine production. The renal epithelial barrier (REB) frequently faces and challenges osmotic dynamics, which gives rise to osmotic pressure (a physical force). Osmotic pressure overloading can crack epithelial integrity and damage the REB. The endurance of REB to osmotic pressure forces remains obscure. LMO7 (LIM domain only 7) is a protein associated with the cell-cell junctional complex and cortical F-actin. Its upregulation was observed in cells cultured under hypertonic conditions. LMO7 is predominantly distributed in renal tubule epithelial cells. Hypertonic stimulation leads to LMO7 and F-actin assembly in the cortical stress fibers of renal epithelial cells. Hypertonic-isotonic alternation, as a pressure force pushing the plasma membrane inward/outward, was set as osmotic disturbance and was applied to test FAK signaling and LMO7 functioning in maintaining junctional integrity. LMO7 depletion in cells resulted in junctional integrity loss in the epithelial sheet-cultured hypertonic medium or hypertonic-isotonic alternation. Conversely, FAK inhibition by PF-573228 led to failure in robust cortical F-actin assembly and LMO7 association with cortical F-actin in epithelial cells responding to hypertonic stress. Epithelial integrity against osmotic stress and LMO7 and FAK signaling are involved in assembling robust cortical F-actin and maintaining junctional integrity. LMO7 elaborately manages FAK activation in renal epithelial cells, which was demonstrated excessive FAK activation present in LMO7 depleted NRK-52E cells and epithelial integrity loss when cells with LMO7 depletion were exposed to a hypertonic environment. Our data suggests that LMO7 regulates FAK activation and is responsible for maintaining REB under osmotic disturbance.

Hyperuricemia, a Non-Independent Component of Metabolic Syndrome, Only Predicts Renal Outcome in Chronic Kidney Disease Patients without Metabolic Syndrome or Diabetes.

Uric acid (UA) is elevated in metabolic syndrome (MS) and diabetes (DM). UA is associated with central obesity and blood glucose and is proposed as a criterion of MS. Previous reports showed that UA could predict renal outcome in CKD. However, recent clinical trials did not demonstrate the benefits of urate-lowering agents (ULA) for renal outcome. Whether the prognostic value of UA for renal outcome is independent of MS or secondary to MS in CKD patients is unknown. Our study included 2500 CKD stage 1−4 Asian patients divided by UA tertiles and MS/DM. In linear regression, UA was associated with obesity, C-reactive protein, and renal function. In Cox regression, high UA was associated with worse renal outcome in non-MS/DM, but not in MS/DM: hazard ratio (95% confidence interval) of UA tertile 3 was 3.86 (1.87−7.97) in non-MS/DM and 1.00 (0.77−1.30) in MS/DM (p for interaction < 0.05). MS was associated with worse renal outcome, but redefined MS (including hyperuricemia as the 6th criteria) was not. In conclusion, hyperuricemia is associated with worse renal outcome in non-MS/DM and is not an independent component of MS in CKD stage 1−4 patients. Hyperuricemia secondary to MS could not predict renal outcome.

Generation of endoplasmic reticulum stress-dependent reactive oxygen species mediates TGF-ß1-induced podocyte migration.

Podocyte migration results in proteinuria and glomerulonephropathy. Transforming growth factor-ß1 (TGF-ß1), endoplasmic reticulum (ER) stress and reactive oxygen species (ROS) can mediate podocyte migration; however, the crosstalk between them is unclear. This study determined the relationships between these factors. ER stress biomarkers (GRP78, p-eIF2α or CHOP), intracellular ROS generation, integrin-ß3 and cell adhesion and migration were studied in a treatment of experiment using TGF-ß1 with and without the ER stress inhibitors: 4-phenylbutyric acid (4-PBA, a chemical chaperone), salubrinal (an eIF2α dephosphorylation inhibitor) and N-acetylcysteine (NAC, an antioxidant). ER stress biomarkers (p-eIF2α/eIF2α and GRP78), ROS generation and intergrin-ß3 expression increased after TGF-ß1 treatment. NAC down-regulated the expression of GRP78 after TGF-ß1 treatment. 4-PBA attenuated TGF-ß1-induced p-eIF2α/eIF2α, CHOP, ROS generation and intergrin-ß3 expression. However, salubrinal did not inhibit TGF-ß1-induced p-eIF2α/eIF2α, CHOP, ROS generation or integrin-ß3 expression. NAC abrogated TGF-ß1-induced integrin-ß3 expression. At 24 h after treatment with TGF-ß1, podocyte adhesion and migration increased. Furthermore, NAC, 4-PBA and an anti-interin-ß3 antibody attenuated TGF-ß1-induced podocyte adhesion and migration. This study demonstrated that TGF-ß1-induced ER stress potentiates the generation of intracellular ROS to a high degree through the PERK/eIF2α/CHOP pathway. This intracellular ROS then mediates integrin-ß3 expression, which regulates podocyte migration.

Macrophage migration inhibitory factor regulates integrin-ß1 and cyclin D1 expression via ERK pathway in podocytes.

AIMS: Macrophage migration inhibitory factor (MIF) is found to increase in proliferative glomerulonephritis. MIF binds to the MIF receptor (CD74) that activates MAP kinase (ERK and p38). Integrins and cyclinD1 regulate cell proliferation, differentiation and adhesion. This study evaluates whether MIF can regulate integrin-ß1/cyclin D1 expression and cell adhesion of podocytes. MAIN METHODS: Expression of integrin-ß1 mRNA/protein and cyclin D1 mRNA under stimulation of MIF was evaluated by real-time PCR and Western blotting. MIF receptor (CD74) and MAP kinase under MIF treatment were examined to determine which pathway regulated integrin-ß1 and cyclin D1 expression. Cell adhesion was evaluated under MIF treatment and/or anti-integrin-ß1 antibody by cell adhesion assay. KEY FINDINGS: Protein levels of integrin-ß1 were up-regulated under MIF treatment in a dosage-dependent manner. CD74 protein levels were not changed after MIF treatment. Integrin-ß1 and cyclin D1 mRNA levels were up-regulated after MIF 100 ng/ml treatment. ERK inhibitor U0126 reduced MIF-induced the increase in integrin-ß1 mRNA and protein expression following MIF stimulation. However, p38 inhibitor SB 203580 did not inhibit MIF-induced increase in integrin-ß1 mRNA and protein expression following MIF stimulation. MIF-induced increase in cyclin D1 mRNA level also was inhibited only by U0126 following MIF stimulation. Podocyte adhesion was increased after MIF treatment, but, anti-integrin-ß1 antibody decreased MIF-enhanced podocyte adhesion. SIGNIFICANCE: MIF increases integrin-ß1 and cyclin D1 expression through the ERK pathway in podocytes, and the up-regulated expression of integrin-ß1 increases podocyte adhesion. These results provide further understanding for the role of MIF in developing proliferative glomerulonephritis.

Effect of differences in serum creatinine estimation methodologies on estimated glomerular filtration rate.

INTRODUCTION: Serum creatinine is crucial in glomerular filtration rate (GFR) estimation. Various methods of measuring GFR have been developed, which vary in their ability to estimate the prevalence of chronic kidney disease (CKD) and predict consequences associated with CKD. The use of different laboratory devices also results in uncertainty in estimated GFR (eGFR). The purpose of our study was to discuss the effect of differences in laboratory devices on eGFR when performing serum creatinine measurements. METHODS: 163 participants aged 51.22 ± 18.66 years were enrolled during a community health screening programme conducted on 18 June 2011. Samples were sent to four different hospitals using four different devices to check serum creatinine by the Jaffe and enzymatic creatinine methods. RESULTS: Using Roche Cobas Integra 400, Beckman LX20, Hitachi 7180 and Toshiba TBA - c8000, the proportion of the population with eGFR < 60 mL/min/1.73 m2 was 11.04%, 6.75%, 20.25% and 20.86%, respectively. Moreover, 3.68% of the participants had eGFR < 60 mL/min/1.73 m2 in the laboratory when Roche Cobas Integra 400 was used with the enzymatic creatinine method and compensated Jaffe method. CONCLUSION: Although standardisation of serum creatinine measurement has been achieved by using isotope dilution mass spectrometry, differences in measurement devices still cause substantial bias in the overall results. This affects the application of GFR in the estimation of CKD progression and outcomes associated with CKD.

Crosstalk between transforming growth factor-ß1 and endoplasmic reticulum stress regulates alpha-smooth muscle cell actin expression in podocytes.

AIMS: Transforming growth factor-ß1 (TGF-ß1) plays a significant role in epithelial-mesenchymal transition (EMT). Furthermore, endoplasmic reticulum (ER) stress also can induce EMT. However, the relationship among TGF-ß1, ER stress and EMT in podocytes is still unclear. Consequently, this study examines the crosstalk effect between TGF-ß1 and ER stress on the regulation of EMT. MAIN METHODS: The mRNA of EMT marker (α-smooth muscle actin: α-SMA) was evaluated by quantitative real-time PCR. In addition, the protein expressions of α-SMA and three ER stress biomarkers (glucose-regulated protein 78: GRP78; eukaryotic translation initiation factor 2α: eIF2α; CCAAT/enhancer-binding protein-homologous protein: CHOP) were evaluated by Western blot. KEY FINDINGS: TGF-ß1 increased the ER stress response biomarkers (GRP78, p-eIF2α/eIF2α and CHOP) and mRNA and protein levels of α-SMA in podocytes. Furthermore, ER stress inducer (thapsigargin) increased α-SMA protein expression. ER stress inhibitor (4-phenylbutyrate) attenuated the ER stress response and α-SMA protein expression under treatment with TGF-ß1. Among the various TGF-ß1 down-stream pathway inhibitors considered in the present study (SIS3: inhibitor of Smad2/3; U0126: inhibitor of MEK/ERK; SB203580: inhibitor of p38), SIS3 greatly attenuated the ER stress response biomarker (GRP78) under treatment with TGF-ß1. SIS3, U0126 and SB203580 all partly attenuated α-SMA mRNA expression under TGF-ß1 treatment. However, only SIS3 attenuated α-SMA protein expression. SIGNIFICANCE: The present results confirm that ER stress induces α-SMA protein expression in podocytes. Furthermore, TGF-ß1 mainly regulates ER stress and α-SMA protein expression through the Smad2/3 pathway. Therefore, ER stress and TGF-ß1 may synergistically induce podocytes to undergo EMT.

TGF-ß1 modulates podocyte migration by regulating the expression of integrin-ß1 and -ß3 through different signaling pathways.

AIMS: Podocyte migration may lead foot process effacement and proteinuria. Transforming growth factor-ß1 (TGF-ß1) and integrins are involved in the adhesion and migration of cells. However, the crosstalk of TGF-ß1 and integrins is unclear. Here, we examined how TGF-ß1 regulates the expression of integrin-ß1 and -ß3 to modulate podocyte adhesion and migration. MAIN METHODS: Podocytes were exposed to TGF-ß1 and/or the inhibitors of Smad2/3, ERK and p38, then the expression of integrin-ß1 and -ß3 was assessed by Real-time PCR and western blot analyses. Podocyte adhesion and migration were measured under TGF-ß1 treatment and/or anti-integrin-ß3 antibody by cell adhesion assay and wound healing assay. KEY FINDINGS: TGF-ß1 had no effect on integrin-ß1 mRNA expression. In the analysis of protein expression, TGF-ß1 decreased the mature form of integrin-ß1, but increased both the precursor form and core peptide of integrin-ß1. The inhibitors of ERK and p38, but not Smad2/3, abrogated TGF-ß1-induced changes in integrin-ß1 protein expression. TGF-ß1 increased integrin-ß3 mRNA and protein levels. The inhibitors of Smad2/3, ERK and p38 attenuated the TGF-ß1-induced increase in integrin-ß3 mRNA and protein levels. Podocyte adhesion and migration were enhanced under the stimulation of TGF-ß1. The blockade of interactions between integrin-αvß3 and the extracellular matrix by the anti-integrin-ß3 antibody abrogated the TGF-ß1-induced enhancement in podocyte adhesion and migration. SIGNIFICANCE: Our results demonstrate that TGF-ß1up-regulates integrin-ß3 expression and down-regulates integrin-ß1 expression through different pathways. The up-regulation of integrin-ß3 expression enhances podocyte migration. This study provides a novel mechanism for TGF-ß1 signaling in regulating podocyte migration.

The inhibition effect of 2,3,7,8-tetrachlorinated dibenzo-p-dioxin-induced aryl hydrocarbon receptor activation in human hepatoma cells with the treatment of cadmium chloride.

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), considered as endocrine disruptors, tend to accumulate in fatty tissues. Dioxin-responsive element chemical activated luciferase gene expression assay (DRE-luciferase assay) has been recognized as a semi-quantitative method for screening dioxins for its fast and low-cost as compared with HRGC/HRMS. However, some problems with the bioassay, including specificity, detection variation resulted from different cleanup strategies, and uncertainty of false-negative or false-positive results, remain to be overcome. Cadmium is a prevalent environmental contaminant around the world. This study was aimed to examine the effects of cadmium on the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced activation of aryl hydrocarbon receptor (AhR)-mediated gene expression in human hepatoma cells (Huh7-DRE-Luc cells and Huh7 cells). Ethoxyresorufin-O-deethylase (EROD) and DRE-luciferase assay were employed to determine the enzyme activity of cytochrome P450 1A1 (CYP1A1) and activation of AhR, respectively. The results showed that Cd(2+) levels significantly inhibited the induction of TCDD-induced CYP1A1 and DRE luciferase activation in hepatoma cells. The 50% inhibited concentrations (IC(50)) of CdCl(2) were 0.414 microM (95% confidence interval (C.I.): 0.230-0.602 microM) in Huh7-DRE-Luc cells and 23.2 microM (95% C.I.: 21.7-25.4 microM) in Huh7 cells. Accordingly, prevention of interference with non-dioxin-like compounds in a DRE-luciferase assay is of great importance in an extensive cleanup procedure.

Increased aquaglyceroporin 9 expression disrupts arsenic resistance in human lung cancer cells.

Resistance to chemotherapy is one of the major problems in treatment responses of lung cancer. This study explored the mechanism underlying the arsenic resistance of lung cancer. Four lung cancer cells with different proliferation activity were characterized for cytotoxicity, arsenic influx/efflux, and arsenic effects on intracellular glutathione and 8-hydroxy-2'-deoxyguanosine (8-OHdG) production. Our data revealed that relative proliferation potency of these cells was H1299>A549>CL3>H1355. Moreover, A549, H1299, and H1355 were markedly resistant to As(2)O(3) with IC50 approximately 100 microM, whereas CL3 was sensitive to As(2)O(3) with IC50 approximately 11.8 microM. After treatment with the respective As(2)O(3) at IC50, arsenic influx/efflux activity in CL3 was comparable to those in the other three arsenic-resistant cells. However, differences in glutathione levels and 8-OHdG production were also detected either before or after arsenic treatment, indicating that a certain degree of variation in anti-oxidative systems and/or 8-OHdG repair activity existed in these cell lines. By transfection of an aquaglyceroporin 9 (AQP9) gene, we showed that increased AQP9 expression significantly enhanced arsenic uptake and disrupted arsenic resistance of A549. The present study strongly suggests that membrane transporters responsible for arsenic uptake, such as AQP9, may play a critical role in development of arsenic resistance in human lung cancer cells.

The effect of nonylphenol on the growth of Lactobacillus acidophilus and Bifidobacterium bifidum.

BACKGROUND AND PURPOSE: Nonylphenol (NP) is a well-known environmental hormone recognized as detrimental to the reproductive systems of aquatic animals and humans. The effect of NP on probiotics in the human gastrointestinal tract remains unclear. This study investigated the effect of NP on the growth of Lactobacillus acidophilus and Bifidobacterium bifidum. METHODS: L. acidophilus and B. bifidum were grown in anaerobic cultures. Both strains were incubated with and without NP. The dose effects of NP on the growth of both probiotics were compared, and the effects of NP on the growth of L. acidophilus and B. bifidum in different concentrations were evaluated. RESULTS: NP 5 to 10 microg/mL inhibited the growth of L. acidophilus (p < 0.05), but was ineffective at 2.5 microg/mL (p > 0.05). NP significantly inhibited the growth of B. bifidum in a dose-dependent manner (p < 0.05). NP inhibited the growth of different concentrations of L. acidophilus (6.25 x 10(4); to 2.5 x 10(5); colony-forming units [CFU]/mL) and B. bifidum (1.25 x 10(9); to 5.0 x 10(9); CFU/mL) [p < 0.05]. CONCLUSIONS: Growth of L. acidophilus and B. bifidum was inhibited by NP. This finding suggests that NP may interfere with normal gastrointestinal microbiota. This may alter immunomodulation in the intestinal mucosa and may be correlated with an increase in the incidence of allergic diseases or other gastrointestinal disorders.

Differential effect of arecoline on the endogenous dioxin-responsive cytochrome P450 1A1 and on a stably transfected dioxin-responsive element-driven reporter in human hepatoma cells.

Dioxin-responsive element-mediated chemical activated luciferase expression (DRE-CALUX) is one of alternative bioassays for the determination of dioxin levels. We have previously established a DRE-CALUX cell line, Huh7-DRE-Luc, by using stable transfection of Huh-7 cells with a reporter plasmid (4xDRE-TATA-Luc) carrying a DRE-driven firefly luciferase gene. It was also shown that arecoline, a major areca nut alkaloid, inhibited the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced cytochrome P450 1A1 (CYP1A1) activation in Huh-7 cells. The TCDD-activated aryl hydrocarbon receptor (AhR) induces the DRE-CALUX activation and CYP1A1 gene expression via binding to DRE in promoter regions of these dioxin-responsive genes. In the present study, the effect of arecoline on the TCDD-induced activation of DRE-CALUX and CYP1A1 enzyme in Huh7-DRE-Luc and Huh-7 cells, respectively, was examined. It was found that arecoline inhibited TCDD-induced CYP1A1 activation and however enhanced TCDD-induced DRE-CALUX activation. This finding indicates the differential effect of arecoline on the endogenous dioxin-responsive CYP1A1 and on a stably transfected DRE-driven reporter in human hepatoma cells. The present study suggests that induction of DRE-CALUX alone does not necessarily parallel with endogenous CYP1A1 gene expression, and that the reporter assay may detect interactions that are not functional in endogenous gene.

Arecoline inhibits the 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced cytochrome P450 1A1 activation in human hepatoma cells.

In the present study, we investigated the effect of arecoline, a major areca nut alkaloid, on the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced activation of cytochrome P4501A1 (CYP1A1) in a human hepatoma cell line Huh-7. We treated Huh-7 cells with 10nM TCDD in the presence of different concentrations of arecoline (50-300 microM). Our results indicated that arecoline attenuated the TCDD-induced CYP1A1 enzyme activation with an inhibitory effect on cell proliferation. By using real-time RT-PCR, we demonstrated that arecoline inhibited the TCDD-induced activations of CYP1A1 and AhR repressor (AhRR) mRNA expression in a similar pattern. Our results revealed that arecoline inhibited AhR mRNA expression with no direct effect on CYP1A1 enzyme activity. Therefore, in our present study, the observed inhibitory effect of arecoline on CYP1A1 activation was not due to the up-regulation of AhRR or direct inhibitory effect on CYP1A1. Taken together, here we have demonstrated that arecoline attenuates the TCDD-induced CYP1A1 activation mainly via down-regulation of AhR expression in human hepatoma cells, suggesting the possible involvement of arecoline in the AhR-mediated metabolism of environmental toxicants in liver.

Arsenic inhibits induction of cytochrome P450 1A1 by 2,3,7,8-tetrachlorodibenzo-p-dioxin in human hepatoma cells.

The aim of this study was to examine the arsenic effect on activation of aryl hydrocarbon receptor (AhR)-mediated gene expression by 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) in human hepatoma cells. The human hepatoma Huh7 cells were treated with sodium arsenite (NaAsO2) from 0.5 to 20 microM for 24 h. Our data revealed that NaAsO2 < or = 10 microM caused no significant cytotoxic effect on Huh7 cells (p>0.05). We also established a dioxin-responsive element (DRE)-mediated Chemical Activated LUciferase eXpression (CALUX) cell line, Huh7-DRE-Luc, by stable transfection of Huh7 with a DRE-driven firefly luciferase reporter plasmid (4xDRE-TATA-Luc). Treatments of Huh7-DRE-Luc and Huh7 with NaAsO2 attenuated the 2,3,7,8-TCDD-induced DRE-CALUX and cytochrome P450 1A1 (CYP1A1) activations, respectively, in a dose-dependent manner. We found that the calculated CALUX-toxic equivalent (TEQ) levels induced by cotreatment of NaAsO2 > or = 3.0 microM and 10 nM 2,3,7,8-TCDD were significantly lower than that induced by 2,3,7,8-TCDD alone (p<0.05). In the present study, we demonstrated that arsenic not only inhibited the TCDD-induced CYP1A1 activation but also interfered with DRE-CALUX bioassay in human hepatoma cells. Our finding also suggests that extensive cleanup of sample for removal of any possible interfering factor is critical to guarantee the accuracy of dioxin-TEQ levels using DRE-CALUX bioassay.

Eosinophil chemoattracted by eotaxin from cerebrospinal fluid of mice infected with Angiostrongylus cantonensis assayed in a microchamber.

When non-permissive hosts are infected with Angiostrongylus cantonensis, the migration of the worms to the brain and their subsequent development manifests as marked eosinophilic pleocytosis. We used microchambers to demonstrate direct eosinophil chemotactic activity by adding a variety of antibodies into cerebrospinal fluid (CSF) of BALB/c mice 21 days post-infection with A. cantonensis. The antibodies were directed to neutralize eotaxin, RANTES (regulated on activation, normal T-cells expressed and secreted), macrophage inflammatory protein (MIP)-1alpha, and platelet-activating factor (PAF), respectively. Eosinophil migration into the polycarbonate membrane covering CSF with anti-eotaxin or anti-MIP-1alpha antibodies was significantly lower than that for antibody-free CSF (Student's t test: p < 0.01, p < 0.05). We also collected CSF from mice 21 days after infection with 10, 20, 30, 40, and 50 third-stage larvae (L3) respectively for dose-dependent testing, and 40 L3 at days 7, 14, and 21 after infection for time-dependent testing. Chemokine production in CSF was affected by A. cantonensis infection intensity and post-infection time. In conclusion, eotaxin and MIP-1alpha released in the CSF of A. cantonensis-infected mice have eosinophil chemotactic activity in this in vitro assay.

Kinetics of change in the eotaxin concentration in serum and cerebrospinal fluid of mice infected with Angiostrongylus cantonensis.

The kinetics of changes in the eotaxin concentration in the serum and cerebrospinal fluid (CSF) of BALB/c mice after infection with Angiostrongylus cantonensis and the correlation between the concentration of eotaxin and worm recovery were investigated. The mean concentration of eotaxin in serum of infected mice gradually increased from 46.3+/-6.5 pg/ml at week 0 to 104.9+/-44.8 pg/ml at week 3 after infection, while the mean eotaxin level in the CSF of infected mice rapidly increased from 18.7+/-2.1 pg/ml to 193.2+/-23.6 pg/ml 1 week after infection and then increased further to 507.8+/-167.9 pg/ml at week 3. The concentrations of eotaxin in the CSF of infected mice each week after infection were all significantly higher than those in serum ( P<0.0001). In parallel with the increase in eotaxin in the CSF, infected mice showed gradual increases in CSF eosinophilia and a reduction in intracranial worm recovery. The concentration of eotaxin in CSF was higher in infected mice with more worms in the brain, except when the number of worms in the brain was >30. In addition, when the worm counts in the brains of infected mice were <30, eotaxin concentrations in the CSF were positively correlated with worm counts in the brain ( P<0.001). Thus, the release of eotaxin in the CSF of mice infected with A. cantonensis observed in this study was time dependent and worm-load dependent, and in parallel with the increase in eotaxin in the CSF, and gradual decreases in worm counts in the brains of infected mice.

Haplorchis infections in intermediate hosts from a clonorchiasis endemic area in Meinung, Taiwan, Republic of China.

Snails and freshwater fish were examined from four ponds in the Meinung township in which Clonorchis sinensis was known to be endemic 18 years ago. No metacercariae were found in 478 Tilapia nilotica, whereas of 451 Ctenopharyngodon idellus examined, 16.2%, 3.3% and 0.9% were found to be infected with Haplorchis pumilio, H. taichui and Clonorchis sinensis, respectively. In addition, there were some unidentified metacercariae in 12.0% of Ctenopharyngodon idellus examined. Overall, no positive correlation between infection rates and sizes of infected fish was shown. Six species of snails were collected in this survey and two frequently-occurring snails, Melanoides tuberculata and Thiara granifera were commonly infected with H. pumilio. Reasons for the prevalence of Haplorchis species and the absence of Clonorchis sinensis in fish and snail hosts in a previously reported endemic area for human clonorchiasis are discussed.