Sweet taste receptors play roles in artificial sweetener-induced enhanced urine output in mice.

Sweet taste receptors found in oral and extra oral tissues play important roles in the regulation of many physiological functions. Studies have shown that urine volume increases during the lifetime exposure to artificial sweeteners. However, the detailed molecular mechanism and the general effects of different artificial sweeteners exposure on urine volume remain unclear. In this study, we investigated the relationship between urinary excretion and the sweet taste receptor expression in mice after three artificial sweeteners exposure in a higher or lower concentration via animal behavioral studies, western blotting, and real-time quantitative PCR experiment in rodent model. Our results showed that high dose of acesulfame potassium and saccharin can significantly enhance the urine output and there was a positive correlation between K+ and urination volume. The acesulfame potassium administration assay of T1R3 knockout mice showed that artificial sweeteners may affect the urine output directly through the sweet taste signaling pathway. The expression of T1R3 encoding gene can be up-regulated specifically in bladder but not in kidney or other organs we tested. Through our study, the sweet taste receptors, distributing in many tissues as bladder, were indicated to function in the enhanced urine output. Different effects of long-term exposure to the three artificial sweeteners were shown and acesulfame potassium increased urine output even at a very low concentration.

Current status of ex-vivo liver resection and autologous liver transplantation for end-stage hepatic alveolar echinococcosis.

Hepatic alveolar echinococcosis (HAE) is a cosmopolitan zoonosis distribute widely in the northern hemisphere with high estimated 10-year mortality. Radical resection combined with oral albendazole administration are the major methods for HAE treatment, whereas most patients delayed diagnosis and treatment because which was considered as benign disease. For the cases with end-stage HAE could not be treated through conventional hepatectomy, allograft liver transplantation (LT) was regarded as a life-saving technique previously. However, graft shortage, high recurrence rate and long-term immunosuppressive therapy limited its utilization. Since the ex-vivo liver resection and autotransplantation (ERAT) procedure was first used in treating for end-stage HAE in 2011, there are more than 120 HAE cases patients were reported treating in this method up to now. Comparing with LT, ERAT needs neither an organ donor nor long term immunosuppressive therapy, and provide preferable overall survival rates. Based on the conventional ERAT procedure, some modification such as auxiliary partial autologous LT were introduced in the high selected end-stage HAE patients presently. However, the standard procedures for ERAT including surgical details and perioperative management have not been established because of limited reported cases. Also, the present ERAT experience for end-stage HAE treatment are all summarizes by the Chinese surgeon groups. For summarizing the knowledge and experience details, we reviewed present opinions about ERAT for end-stage HAE patients, and presented the future perspectives about this topic in this manuscript. We aimed at discussing the feasibility, indications, preparation, technical details, and postoperative outcomes of ERAT for HAE patients.

Downregulation of lncRNA CCAT1 enhances 5-fluorouracil sensitivity in human colon cancer cells.

BACKGROUND: The purpose of this study was to determine the aberrant expression of the long noncoding RNA (lncRNA) colon cancer-associated transcript 1 (CCAT1) in 5-fluorouracil-resistant colonic neoplasm cells and to elucidate its effects on the 5-fluorouracil sensitivity of human colonic neoplasm cells. The aberrant expression of lncRNAs in normal tissues and colonic neoplasm tissues was detected by microarray assay. qRT-PCR analysis was performed to assess CCAT1 expression levels in colonic neoplasm cell lines and corresponding normal tissues. After constructing the 5-FU-resistant cell lines and validating the resistance by measuring the IC50 value, the CCAT1 expression levels in parental and artificially resistant cell lines were determined by qRT-PCR. Transfection was used to modulate the expression of CCAT1. Cell proliferation and apoptosis were then detected by CCK-8 and flow cytometry, respectively. RESULTS: CCAT1 in colon cancer tissues was higher than that in noncancer tissues, and the levels of CCAT1 in HCT 116, SW1417, HT-29, and KM12 cell lines were higher than those in the human normal colon epithelial NCM460 cell line. Moreover, the expression levels of CCAT1 were high in HCT 116/5-FU and HT-29/5-FU cell lines, whose apoptosis rates induced by 5-FU were lower than those in corresponding parental cells. The results of qRT-PCR and CCK-8 assay showed that enhancement of lncRNA CCAT1 expression levels in HCT 116 and HT-29 cell lines increased their IC50 of 5-FU and decreased their apoptosis rates. Meanwhile, siRNA-CCAT1 effectively inhibited the expression of CCAT1 and enhanced the 5-FU-sensitivity of HCT 116/5-FU and HT-29/5-FU, in which apoptosis rates were increased at the same time. CONCLUSIONS: Downregulation of CCAT1 effectively reversed the resistance of HCT 116/5-FU and HT-29/5-FU cells to 5-FU chemotherapeutic, opening a new avenue in colon cancer therapy.

[Mechanism of hsa-miR-302a-3p-targeted VEGFA in the Inhibition of Proliferation of Gastric Cancer Cell].

OBJECTIVE: To explore the role mechanism of hsa-miR-302a-3p overexpression in the inhibition of proliferation of gastric cancer cell SGC-7901 by targeted-regulating vascular endothelial growth factor A (VEGFA). METHODS: The cell transfection was used to transfect hsa-miR-302a-3p mimic into miR mimic group and transfect pc-VEGFA into VEGFA group, and the two genes were co-transfected into miR+VEGFA group. The transfection efficiency was detected by RT-PCR and Western blot. The bioinformatics targeting prediction and fluorescein assay were used to verify the targeting relationship between the two genes. Cell proliferation was detected by CCK-8 test, and Transwell assay was used to detect the invasion ability of each group, and scratch assay was used to detect the migration ability of each group. The morphology changes of epithelial-mesenchymal transition (EMT) in cells were observed under microscope. Western blot was used to detect the protein expression levels of survival-related proteins Ki67 and Caspase-3, EMT-related proteins E-cadherin, Vimentin, N-cadherin and Snail and VEGFA downstream target genes p-P38, p-MAPKAPK and p-Hsp27. RESULTS: VEGFA was the predicted target site of miR-302a-3p. Compared with control group, the number of cells, the invasion and migration rates were also reduced ( P<0.05) in miR mimic group, and the number of cells was increased ( P<0.05) as well as the invasion and migration rates in VEGFA group. Compared with VEGFA group, the number of cells, the invasion and migration rates were also decreased ( P<0.05) in miR+VEGFA group. The protein expression level of E-cadherin was up-regulated ( P<0.05) while the protein expression levels of Vimentin, N-cadherin and Snail were down-regulated ( P<0.05), and the protein expression levels of p-P38, p-MAPKAPK and p-Hsp27 were also down-regulated ( P<0.05). CONCLUSION: hsa-miR-302a-3p overexpression can inhibit the proliferation and promote apoptosis of gastric cancer cell SGC-7901 by targeting negative regulation of VEGFA expression.

Vesicle formation by ultrashort alkyl-phosphonic acids and serine in aqueous solutions.

Vesicles possess unique biofilm structures and offer biomimetic advantages for drug and gene delivery. Herein, we report the spontaneous vesicle formation from ultrashort alkyl-phosphonic acids in the presence of amino acids. The aggregation characteristics and self-assembly structures of vesicles in aqueous solution were investigated by using dynamic light scattering, zeta potential, and cryo-transmission electron microscopy. We combined low-field nuclear magnetic resonance and Fourier transform infrared spectroscopy to study the H-proton-induced multilamellar vesicle formation. When we increased the molar fraction of serine, stable and closed spherical vesicles were formed at relatively low critical micelle concentrations. This transition of the self-assembled structure indicates that vesicle formation occurs when the chain length and the magnitude of the surface charge cause a fluctuation in the volume of the vesicle. Density functional theory reveals the critical role of the mixed alkyl-phosphonic acid/amino acid-enhanced electrostatic attraction between the head groups and hydrogen bonds associated with the aggregated states.

Rapamycin inhibits activation of AMPK-mTOR signaling pathway-induced Alzheimer's disease lesion in hippocampus of rats with type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is strongly correlated with Alzheimer's disease (AD). Rapamycin has important uses in oncology, cardiology and transplantation medicine. This study aims to investigate effects of rapamycin on AD in hippocampus of T2DM rat by AMPK/mTOR signaling pathway. METHODS: Morris water maze test was applied to evaluate the learning and memory abilities. The fasting plasma glucose (FBG), glycosylated haemoglobin, total cholesterol, triglyceride and serum insulin level were measured. RT-qPCR and Western blot analysis were performed to test expression of AMPK and mTOR. Immunohistochemistry was used to detect the Aß deposition and immunoblotting to test the total tau, p-tau and Aß precursor APP expressions. RESULTS: After treated with rapamycin, T2DM rats and rats with T2DM and AD showed increased learning-memory ability, and decreased levels of FBG, glycosylated hemoglobin, total cholesterol, triglyceride and serum insulin, decreased expression of APP and p-tau, increased AMPK mRNA expression and p-AMPK and decreased Aß deposition, mTOR mRNA expression and p-mTOR. CONCLUSION: The study demonstrated that rapamycin reduces the risk of AD in T2DM rats and inhibits activation of AMPK-mTOR signaling pathway, thereby improving AD lesion in hippocampus of T2DM rats.

Vesicles from the self-assembly of the ultra-small fatty acids with amino acids under aqueous conditions.

The properties of vesicles formed from the self-assembly of amphiphilic molecules can mimic the functionality of the natural lipid membranes. In this study, the self-assembly process of the amphiphilic structures formed by the interaction between ultra-small fatty acids [FAs, Cn (n = 4-8)] and amino acids (AAs) to generate vesicles under aqueous conditions were investigated in detail, along with the corresponding dynamic vesiculation mechanisms. Our results showed that the molar ratio of FAs/AAs and the chain length of FAs largely affected the structural characteristics and dispersion of vesicles. The detailed information about the entire size distributions and morphology of obtained vesicles were explored by the cryogenic transmission electron microscopy (Cryo-EM). Fourier transform infrared (FT-IR) spectra and quantum calculations suggested that the intermolecular hydrogen bond and electrostatic interactions between ultra-small molecules (FAs and AAs) during the aggregation processes were responsible for the formation of vesicles, where the hydrogen-bonding effect was dominant. Our findings shed new light on the effective and simple preparation of biological vesicles via ultra-small molecules self-assembly in aqueous solutions, which may have potential applications in vesicle physiology and drug delivery systems, and also get a mature understanding of the fundamental intermolecular interactions in life process.

Diagnostic Significance of Serum Levels of Nerve Growth Factor and Brain Derived Neurotrophic Factor in Diabetic Peripheral Neuropathy.

BACKGROUND Our study aimed to explore the levels of nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) in healthy participants, type 2 diabetes mellitus (T2DM) patients, and diabetic peripheral neuropathy (DPN) patients in order to find their effects on DPN. MATERIAL AND METHODS The clinical data of 110 healthy participants (age: 57.3±8.2 year, height: 165.4±5.5 cm, weight: 64.1±7.5 kg), 83 T2DM patients (age: 56.5±7.9 year, height: 164.8±6.2 cm, and weight: 63.6±6.6 kg), and 65 DPN patients (age: 58.2±7.3 year, height: 166.7±6.7 cm, weight: 63.1±5.8 kg) were observed. ELISA was applied to detect serum NGF and BDNF levels. Receiver operating characteristic (ROC) curve analysis was performed to evaluate diagnostic value of serum NGF and BDNF levels in DPN. Logistic regression analysis was performed to analyze risk factors for DPN. RESULTS Serum NGF and BDNF levels decreased most in DPN patients. Subsequently, we determined that serum NGF and BDNF levels were correlated with: the course of disease for patients, fasting C-peptide (FCP), 2-hour postprandial C-peptide level (2-h PCP), glycosylated hemoglobin level (HbAlc), and 24-hour urinary microalbumin excretion (24-h UME). ROC curve analysis identified high sensitivity, specificity, and accuracy of NGF and BDNF levels on DPN. Serum levels of NGF and BDNF, course of disease, 2-h PCP level, and postprandial blood glucose level were determined to be risk factors for DPN. CONCLUSIONS Our study highlights that serum levels of NGF and BDNF might be associated with the occurrence and development of DPN.

Comparisons of Effects on Intestinal Short-Chain Fatty Acid Concentration after Exposure of Two Glycosidase Inhibitors in Mice.

Acarbose and voglibose are the most widely used diabetes drugs as glycosidase inhibitors. In this study, the use of these two inhibitors significantly increased the content of starch in large intestine, and altered the concentration of short-chain fatty acids (SCFAs) by affecting the intestinal microbiota. However, there are some differences in the intestinal microbiome of the two groups of mice, mainly in bacteria such as Bacteroidaceae bacteroides and Desulfovibrionaceae desulfovibrio. The productions of acetate and propionate in caecum in voglibose group were significantly higher than those in acarbose group and two kinds of glycosidase inhibitors were close in the production of butyrate in caecum. The Tax4Fun analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) data indicated that different productions of acetate and propionate between acarbose group and voglibose group may be related to 2-oxoisovalerate dehydrogenase and pyruvate oxidase. In addition, in-vitro experiments suggested that voglibose had less effect on epithelial cells than acarbose after direct stimulation. According to the recent researches of SCFAs produced by intestinal microbiota, our comparative study shown higher concentration of these beneficial fatty acids in the lumen of voglibose-treated mice, which implied a lower level of inflammation.

Vesicle formation by proton transfer driven short-tailed fatty acids of C4-C8 chain length in water.

Ultrashort single-chain fatty acids self-assemble to form vesicles under certain proton-driven conditions. The protonation provides a larger charge area around the hydrophilic carbonyl headgroups, and proton shift as the key driving parameter was studied. The ultrashort fatty acids (C4-C8) formed stable unilamellar vesicles predominantly through out the whole range of tested pH levels (6.5-9.5). A proton-driven self-assembly process and effects on the phase transition were characterized by dynamic light scattering, transmission electron microscopy and cryo-transmission electron microscopy. In particular, we studied in greater detail the molecular packing characteristics of FA vesicles for geometric reasons and the protonation effect changes the molecular surface charge and further carboxylic acid headgroup motion. This study enhances the understanding of the physicochemical specificity of these membrane vesicles, and may facilitate the alteration of membrane function caused by FAs.

Anti-CD45RB and donor-specific spleen cells transfusion inhibition allograft skin rejection mediated by memory T cells.

Donor-reactive memory T (Tm)cells mediate accelerated rejection, which is known as a barrier to the survival of transplanted organs. Selective interference with the anti-CD45RB monoclonal antibody (α-CD45RB) reliably induces donor-specific tolerance. In this study, pre-sensitization to female C57BL/6 mice with the skin of female BLAB/c mice generated a large number of Tm cells and resulted in rapid rejection of the secondly transplanted allografts. α-CD45RB did induce the tolerance to skin allograft primarily transplanted but failed to induce tolerance in the pre-sensitized mice. Donor-specific spleen cell transfusion (DST) alone also failed to induce the tolerance in the pre-sensitized recipients. Interestingly, combination of α-CD45RB with DST inhibited the rejection induced by memory T cells in the pre-sensitized mice. CD25+ T-cell depletion in α-CD45RB combined with DST therapy recipients could prevent skin allograft tolerance from establishing. In addition, adoptive transfer of donor-primed memory T cells into the tolerant recipients markedly broke the established tolerance. Our findings indicate that α-CD45RB and DST can synergistically inhibit the accelerated rejection mediated by memory T cells and induce long-term skin allograft acceptance in mice.

Sweetness-induced activation of membrane dipole potential in STC-1 taste cells.

The biological functions of cell membranes strongly influence the binding and transport of molecular species. We developed STC-1 cell line stably expressing the sweet taste receptor (T1R2/T1R3), and explored the possible correlation between sweeteners and membrane dipole potential of STC-1 cells. In this study, sweetener-induced dipole potential activation was elucidated using a fluorescence-based measurement technique, by monitoring the voltage sensitive probe Di-8-ANEPPS using a dual wavelength ratiometric approach. It indicated that the presence of sweeteners resulted in cell membrane dipole potential change, and interaction of artificial sweeteners with taste cells resulted in a greater reduction in potential compared with natural sweeteners. Our work presents a newly developed approach using a fluorescence-based measurement technique to study sweetener-induced dipole potential activation of STC-1 cells. This new approach could be used as a complementary tool to study the function of sweet taste receptors or other GPCRs and helps to understand the basis sweetness mechanism.

The roles of IL-2 and IL-10 enhance anti-CD45RBmAb immune inhibition in allograft skin.

As a new type of immune tolerance inducer, anti-CD45RB monoclonal antibodies (anti-CD45RBmAb) can prolong the graft survival time of animal organs or cell transplantation as well as induce stable immune tolerance. Both interleukin (IL)-2 and IL-10 have important roles in the induction and maintenance of immunological tolerance. However, whether these cytokines combined with anti-CD45RBmAb can promote immune tolerance is poorly understood. Therefore, we investigated the effect of IL-2 and IL-10 in vitro and in vivo on the tolerance induction by anti-CD45RBmAb. The changes of Treg and Th17 cells and Th1/Th2 cytokines in anti-CD45RBmAb induced prolongation of skin allograft survival in mice. The finding of a role for IL-2 is novel, of interest, IL-2 promoted anti-CD45RBmAb-induced CD4(+) T cell differentiation into Treg and Th2 cells and suppressed Th17 and Th1 cells. IL-2 enhanced the induction of immune tolerance by anti-CD45RBmAb and significantly prolonged skin graft survival time in vivo. In contrast, this effect should be demonstrated experimentally by neutralizing IL-2 and inhibition of the effect of anti-CD45RBmAb, and neutralizing IL-10 showed no effect for anti-CD45RBmAb-induced tolerance. These data reveal that IL-2 significantly enhances anti-CD45RBmAb-induced immune tolerance via up-regulated T regulatory (Treg) cells and the balance of Th1/Th2 shifts. Conversely, IL-10 showed no effect on anti-CD45RBmAb-induced tolerance.

Clinical outcome of autologous hematopoietic stem cell infusion via hepatic artery or portal vein in patients with end-stage liver diseases.

OBJECTIVE: To investigate the efficacy of hematopoietic stem cell (HSC) transplantation via the hepatic artery vs. the portal vein for end-stage liver disease (ESLD). METHODS: Patients with hepatic decompensation were prospectively recruited from September 2010 to September 2012 to receive HSC transplantation via the hepatic artery or the portal vein. Liver function was examined at 3, 6, and 12 months after transplantation. Liver biopsy Results were analyzed using the Knodell score. RESULTS: Eighty patients (58 males and 22 females) were enrolled in the study. The Child-Pugh score was grade B in 69 cases, and grade C in the remaining 11 cases. HSC transplantation was performed via the portal vein in 36 patients and via the hepatic artery in 44 patients. ALT levels decreased while serum albumin levels increased significantly in both groups at 6 and 12 months after HSC transplantation (P<0.05 compared with pre-transplantation levels). Total bilirubin levels decreased significantly in both groups at 3, 6, and 12 months after HSC transplantation (P<0.05 compared with pre-transplantation levels). Additionally, prothrombin time decreased in both groups at 12 months after HSC transplantation (P<0.05 compared with pre-transplantation level). There were no significant differences in ALT, total bilirubin and prothrombin time between the two groups either before or after transplantation. Moreover, Knodell score decreased significantly at 6 and 12 months. Histological examination showed that liver cell edema, degeneration, necrosis, and inflammation were significantly relieved at 3, 6, and 12 months after transplantation. The incidence of portal vein thrombosis, upper gastrointestinal bleeding, and hepatic encephalopathy were 1.25%, 3.75%, and 2.5% respectively. The one-year survival rate was 100%. CONCLUSIONS: Autologous HSC transplantation improves liver function and histology in ESLD patients. The administration route of HSC has no significant impact on the efficacy of transplantation.

Influence of interferon-α on the expression of the cancer stem cell markers in pancreatic carcinoma cells.

The cytokine interferon-α (IFNα) belongs to the group of type I interferons already used in cancer therapy. This drug possesses radio- and chemo-sensitizing, and shows anti-angiogenic properties. Cancer stem cells (CSC) are a unique population of tumor cells that initiate secondary tumors, and are responsible for metastasis formation. Patients with pancreatic ductal adenocarcinoma (PDAC) have an especially poor prognosis, with 5-year survival rates of only ~1% and median survival of 4-6 months. PDAC is characterized by the presence of CSC. In this work we demonstrate for the first time that IFNα up-regulates the expression of the CSC markers CD24, CD44 and CD133 in in vitro and in vivo models of PDAC. We showed the IFNα effects on the migration and invasion of PDAC cells, which is associated with the level of the CSC marker expression. In vivo, this drug inhibits tumor growth but promotes metastasis formation in the early stage of tumor growth. We propose that IFNα may enhance the enrichment of CSC in PDAC tumors. Additionally we also suggest that in combination therapy of solid tumors with IFNα, this drug should be given to patients prior to chemotherapy to achieve the CSC activation.

Chain-length-dependent autocatalytic hydrolysis of fatty acid anhydrides in polyethylene glycol.

Autocatalytic hydrolysis of fatty acid anhydrides induced by the spontaneously formed vesicles has been studied for years. However, whether the reaction autocatalyzed by vesicles formed in diluted solutions applies also to macromolecular crowded conditions remains unknown. The aim of this study is to characterize hydrolysis behavior of fatty acid anhydrides and formation of vesicles in crowded media. Inert macromolecular crowding agents such as polyethylene glycol (PEG) and Dextran were used to probe the impact of external crowding on the autocatalytic hydrolysis of fatty acid anhydrides with varied hydrophobic chain length. Under stringent conditions of crowding, hydrolysis rates of octanoic anhydride, nonanoic anhydride, and decanoic anhydride were found to decrease, but the rates of lauric anhydride and oleic anhydride increased. These results suggest that the effect of the crowding agent on the hydrolysis of fatty acid anhydrides was chain-length-dependent. Characterization of the size and polydispersity of vesicles formed from hydrolyzed fatty acid anhydrides in crowding revealed that long-chain fatty acids formed monodisperse vesicles easier at lower concentrations of PEG. Measurement of the critical aggregation concentration of ionized fatty acid in the presence of PEG showed that crowding media promoted vesicle formation from long-chain fatty acids but inhibited those from fatty acids with fewer carbon atoms. Further investigation of the diffusion property of ionized fatty acids in crowding agents suggested that PEG might create more hydrophobic areas for long-chain fatty acids anhydrides, which subsequently promoted the unreacted anhydride in the aqueous phase to be solubilized in the formed vesicles. This research provides information for understanding the autocatalytic reaction accompanied by self-producing aggregates and the behavior of fatty acids in crowding media.

Thermodynamics of the enantiomers of amino acid and monosaccharide binding to fullerenol used as an artificial sweet taste receptor model.

Fullerenol was used as sweet taste receptor model to investigate the binding affinities of structurally related pairs of enantiomers by isothermal titration calorimetry (ITC). It reveals that amino acid binding with fullerenol are enthalpy-cost and entropically-driven processes, whereas enthalpy contributes to monosaccharide binding to fullerenol. Spontaneous binding of amino acids was found through two sequential steps in which the sweeter enantiomer displays larger binding constants. Association of the d-form of fructose and l-form galactose with fullerenol suggested that, the higher the perceived sweetness intensity of the enantiomer, the larger was the binding constant with respect to their antipodes. Further investigation by molecular dynamic simulation showed that the binding energy and the perceived sweetness intensity were well correlated. The preliminary results of this biomimetic research cover the lack of information about the thermodynamic basis of sweet sensation and the underlying principles of sweetness differences between the enantiomers of amino acids and monosaccharides.

Electrochemical impedance spectrum frequency optimization of bitter taste cell-based sensors.

Electrochemical impedance spectrum frequency optimization to bitter taste receptor cell-based sensors is discussed in this paper. The bitter taste receptor cells (the enteroendocrine STC-1 cells and the ICR mouse isolated taste bud cells) are cultured on carbon screen printed electrodes and used as sensing elements. The HEK-293 cells and dead isolated ICR mouse taste bud cells, without bitter taste receptor expression, are used in negative control experiments. The electrochemical impedance spectrum data is recorded and processed by bistable stochastic resonance for signal-to-noise ratio analysis. The bitter taste receptor cell-based sensor selectively responds to bitter tastants. The tastants species and concentrations can be decided by signal-to-noise ratio parameters. The signal-to-noise ratio eigen peak changes with the shift of electrochemical impedance spectrum frequencies. ICR mouse isolated taste bud cell-based sensor presents bitter tastants perception abilities. 9kHz is the optimal frequency for STC-1 cell-based sensor measurement. For isolated ICR mouse taste bud cells, 1.2kHz is the optimal frequency. Negative control experiments results indicate that cells with no taste receptor expression have no discriminating ability for tastant even if they are modulated by different frequencies. The taste cell-based sensor is of great practical value.

Effects of early intraoral acesulfame-K stimulation to mice on the adult's sweet preference and the expression of α-gustducin in fungiform papilla.

Exposure to artificial sweetener acesulfame-K (AK) at early development stages may influence the adult sweet preference and the periphery gustatory system. We observed that the intraoral AK stimulation to mice from postnatal day 4 (P4) to weaning decreased the preference thresholds for AK and sucrose solutions in adulthood, with the preference pattern unchanged. The preference scores were increased in the exposure group significantly when compared with the control group at a range of concentrations for AK or sucrose solution. Meanwhile, more α-Gustducin-labeled fungiform taste buds and cells in a single taste bud were induced from week 7 by the early intraoral AK stimulation. However, the growth in the number of α-Gustducin-positive taste bud or positive cell number per taste bud occurred only in the anterior region, the rostral 1-mm part, but not in the intermediate region, the caudal 4-mm part, of the anterior two-third of the tongue containing fungiform papillae. This work extends our previous observations and provides new information about the developmental and regional expression pattern of α-Gustducin in mouse fungiform taste bud under early AK-stimulated conditions.

A role for anti-CD45RB monoclonal antibody treatment upon dendritic cells.

Selective interference with CD45RB isoform by monoclonal antibody (anti-CD45RBmAb) reliably induces donor-specific tolerance. Dendritic cells (DCs) are the most potent antigen-presenting cells that are capable of activating naïve T cells. The purposes of the present study were to investigate the roles of anti-CD45RBmAb on the phenotypes and functioning of DCs and to further illustrate the mechanism of anti-CD45RBmAb-inducing immunologic tolerance. DCs from C57BL/6 mice were cultured and treated with various doses of anti-CD45RB monoclonal antibody. Cell phenotype, cycle and phagocytic ability were detected by flow cytometry. The production of IL-10 and IL-12 in the supernatants of mature DCs was measured with ELISA. Exosomes (Dex) were recovered from the supernatant of DCs cultured for 6 days in depleted medium, and effects of DCs and Dex on the ability of T-cell proliferation were detected by mixed lymphocyte culture. Anti-CD45RBmAb could inhibit DCs maturation in a dose-dependent manner, and the effects of exosomes (Dex) on DCs enhance or inhibition proliferation of T cells were also in a dose-dependent manner. Anti-CD45RBmAb could profoundly inhibit the maturation and functioning of DCs and generate tolerogenic dendritic cells (tDCs) as well as Dex, suggesting mechanistic contributions to tolerance development from the DCs through interactions with T cells.