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Sample records for inhibition differentially modulates

  1. Modulation of cartilage differentiation by melanoma inhibiting activity/cartilage-derived retinoic acid-sensitive protein (MIA/CD-RAP).

    PubMed

    Schubert, Thomas; Schlegel, Jacqueline; Schmid, Rainer; Opolka, Alfred; Grassel, Susanne; Humphries, Martin; Bosserhoff, Anja-Katrin

    2010-03-31

    Melanoma inhibiting activity/cartilage-derived retinoic acid-sensitive protein (MIA/CD-RAP) is a small soluble protein secreted from malignant melanoma cells and from chondrocytes. Recently, we revealed that MIA/CD-RAP can modulate bone morphogenetic protein (BMP)2-induced osteogenic differentiation into a chondrogenic direction. In the current study we aimed to find the molecular details of this MIA/CD-RAP function. Direct influence of MIA on BMP2 by protein-protein-interaction or modulating SMAD signaling was ruled out experimentally. Instead, we revealed inhibition of ERK signaling by MIA/CD-RAP. This inhibition is regulated via binding of MIA/CD-RAP to integrin alpha5 and abolishing its activity. Active ERK signaling is known to block chondrogenic differentiation and we revealed induction of aggrecan expression in chondrocytes by treatment with MIA/CD-RAP or PD098059, an ERK inhibitor. In in vivo models we could support the role of MIA/CD-RAP in influencing osteogenic differentiation negatively. Further, MIA/CD-RAP-deficient mice revealed an enhanced calcified cartilage layer of the articular cartilage of the knee joint and disordered arrangement of chondrocytes. Taken together, our data indicate that MIA/CD-RAP stabilizes cartilage differentiation and inhibits differentiation into bone potentially by regulating signaling processes during differentiation.

  2. Inhibition of damage-regulated autophagy modulator-1 (DRAM-1) impairs neutrophil differentiation of NB4 APL cells.

    PubMed

    Humbert, Magali; Mueller, Chantal; Fey, Martin F; Tschan, Mario P

    2012-12-01

    The damage-regulator autophagy modulator 1 (DRAM-1) is a lysosomal protein that positively regulates autophagy in a p53-dependent manner. We aimed at analyzing the role of DRAM-1 in granulocytic differentiation of APL cells. We observed a significant increase of DRAM-1 expression during all-trans retinoic acid (ATRA)-induced neutrophil differentiation of NB4 APL cells but not in ATRA-resistant NB4-R2 cells. Next, knocking down DRAM-1 in NB4 APL cells was sufficient to impair neutrophil differentiation. Given that DRAM-1 is a transcriptional target of p53, we tested if DRAM-1 is regulated by the p53 relative p73. Indeed, inhibiting p73 prevented neutrophil differentiation and DRAM-1 induction of NB4 cells. In conclusion, we show for the first time that p73-regulated DRAM-1 is functionally involved in neutrophil differentiation of APL cells.

  3. Differential Modulation of Intracortical Inhibition in Human Motor Cortex during Selective Activation of an Intrinsic Hand Muscle

    PubMed Central

    Zoghi, Maryam; Pearce, Sophie L; Nordstrom, Michael A

    2003-01-01

    Paired-pulse transcranial magnetic stimulation (TMS) was used to assess the effectiveness of intracortical inhibition (ICI) acting on corticospinal neurons controlling three intrinsic hand muscles in humans. We hypothesised that the suppression of ICI with selective activation of a muscle would be restricted to corticospinal neurons controlling the muscle targeted for activation. Surface EMG was recorded from abductor pollicis brevis (APB), first dorsal interosseous (FDI) and abductor digiti minimi (ADM) muscles of the left hand. Subjects were tested at rest and during weak selective activation of APB or ADM, while they attempted to keep the other muscles relaxed using visual feedback. Paired-pulse TMS was applied with a circular coil oriented to produce antero-posterior (AP) current flow in the right motor cortex (to preferentially evoke I3 waves in corticospinal neurons) and with postero-anterior (PA) currents (to preferentially evoke I1 waves). Paired-pulse TMS was less effective in suppressing the muscle evoked potential (MEP) when the muscle was targeted for selective activation, with both AP and PA stimulation. The mechanism for this includes effects on late I waves, as it was evident with a weak AP test TMS pulse that elicited negligible I1 waves in corticospinal neurons. ICI circuits activated by TMS, which exert their effects on late I waves but do not affect I1 waves, are strongly implicated in this modulation. With AP stimulation, paired-pulse inhibition was not significantly altered for corticospinal neurons controlling other muscles of the same hand which were required to be inactive during the selective activation task. This differential modulation was not seen with PA stimulation, which preferentially activates I1 waves and evokes a MEP that is less influenced by ICI. The observations with AP stimulation suggest that selective activation of a hand muscle is accompanied by a selective suppression of ICI effects on the corticospinal neurons controlling

  4. HIV-1 Tat Inhibits Autotaxin Lysophospholipase D Activity and Modulates Oligodendrocyte Differentiation

    PubMed Central

    Wheeler, Natalie A.; Fuss, Babette; Knapp, Pamela E.

    2016-01-01

    White matter injury has been frequently reported in HIV+ patients. Previous studies showed that HIV-1 Tat (transactivator of transcription), a viral protein that is produced and secreted by HIV-infected cells, is toxic to young, immature oligodendrocytes (OLGs). Adding Tat to the culture medium reduced the viability of immature OLGs, and the surviving OLGs exhibited reduced process networks. OLGs produce and secrete autotaxin (ATX), an ecto-enzyme containing a lysophospholipase D (lysoPLD) activity that converts lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA), a lipid signaling molecule that stimulates OLG differentiation. We hypothesized that Tat affects OLG development by interfering with the ATX-LPA signaling pathway. Our data show that Tat treatment leads to changes in the expression of OLG differentiation genes and the area of OLG process networks, both of which can be rescued by LPA. Tat-treated OLGs showed no change in LPA receptor expression but significantly decreased extracellular ATX levels and lysoPLD activity. In Tat transgenic mice, expression of Tat in vivo leads to decreased OLG ATX secretion. Furthermore, co-immunoprecipitation experiments revealed a potential physical interaction between Tat and ATX. Together, these data strongly suggest two functional implications of Tat blocking ATX’s lysoPLD activity. On one hand, it attenuates OLG differentiation, and on the other hand it interferes with the protective effects of LPA on OLG process morphology. PMID:27659560

  5. Inhibition of LINE-1 retrotransposon-encoded reverse transcriptase modulates the expression of cell differentiation genes in breast cancer cells.

    PubMed

    Patnala, Radhika; Lee, Sung-Hun; Dahlstrom, Jane E; Ohms, Stephen; Chen, Long; Dheen, S Thameem; Rangasamy, Danny

    2014-01-01

    Long Interspersed Elements (L1 elements) are biologically active retrotransposons that are capable of autonomous replication using their own reverse transcriptase (RT) enzyme. Expression of the normally repressed RT has been implicated in cancer cell growth. However, at present, little is known about the expression of L1-encoded RT activity or the molecular changes that are associated with RT activity in the development of breast cancer. Here, we report that RT activity is widespread in breast cancer cells. The expression of RT protein decreased markedly in breast cancer cells after treatment with the antiretroviral drug, efavirenz. While the majority of cells showed a significant reduction in proliferation, inhibition of RT was also accompanied by cell-specific differences in morphology. MCF7 cells displayed elongated microtubule extensions that adhered tightly to their substrate, while a large fraction of the T47D cells that we studied formed long filopodia projections. These morphological changes were reversible upon cessation of RT inhibition, confirming their dependence on RT activity. We also carried out gene expression profiling with microarrays and determined the genes that were differentially expressed during the process of cellular differentiation. Genes involved in proliferation, cell migration, and invasive activity were repressed in RT-inhibited cells. Concomitantly, genes involved in cell projection, formation of vacuolar membranes, and cell-to-cell junctions were significantly upregulated in RT-inhibited cells. qRT-PCR examination of the mRNA expression of these genes in additional cell lines yielded close correlation between their differential expression and the degree of cellular differentiation. Our study demonstrates that the inhibition of L1-encoded RT can reduce the rate of proliferation and promote differentiation of breast cancer cells. Together, these results provide a direct functional link between the expression of L1 retrotransposons and

  6. Differentiating spatial light modulator

    NASA Astrophysics Data System (ADS)

    Armitage, D.

    1985-04-01

    A differentiating spatial light modulator device in which a photoreceptor and an electro-optic crystal are isolated by a dielectric mirror is discussed. The electro-optic crystal is configured to have low or zero longitudinal response, yet is sensitive to transverse electric fields. The fringe field generated by the photoreceptor (photodiode) modulates the crystal birefringence. Readout via a polarizing beamsplitter gives an output light related to the spatial gradient of the input light. In a liquid crystal embodiment of the invention, reversal of the applied voltage gives a driven off state which speeds the erasure. Storage is possible in the smectic liquid crystal phase.

  7. The human nucleophosmin 1 mutation A inhibits myeloid differentiation of leukemia cells by modulating miR-10b

    PubMed Central

    Zou, Qin; Tan, Shi; Yang, Zailin; Wang, Juan; Xian, Jingrong; Zhang, Shuaishuai; Jin, Hongjun; Yang, Liyuan; Wang, Lu; Zhang, Ling

    2016-01-01

    Mutations in the nucleophosmin 1 (NPM1) gene are the most frequent genetic alteration in acute myeloid leukemia (AML). Here, we showed that enforced expression of NPM1 mutation type A (NPM1-mA) inhibits myeloid differentiation of leukemia cells, whereas knockdown of NPM1-mA has the opposite effect. Our analyses of normal karyotype AML samples from The Cancer Genome Atlas (TCGA) dataset revealed that miR-10b is commonly overexpressed in NPM1-mutated AMLs. We also found high expression of miR-10b in primary NPM1-mutated AML blasts and NPM1-mA positive OCI-AML3 cells. In addition, NPM1-mA knockdown enhanced myeloid differentiation, while induced expression of miR-10b reversed this effect. Finally, we showed that KLF4 is downregulated in NPM1-mutated AMLs. These results demonstrated that miR-10b exerts its effects by repressing the translation of KLF4 and that NPM1-mA inhibits myeloid differentiation through the miR-10b/KLF4 axis. This sheds new light on the effect of NPM1 mutations' on leukemogenesis. PMID:27669739

  8. Nitric oxide inhibits neointimal hyperplasia following vascular injury via differential, cell-specific modulation of SOD-1 in the arterial wall.

    PubMed

    Bahnson, Edward S M; Koo, Nathaniel; Cantu-Medellin, Nadiezhda; Tsui, Aaron Y; Havelka, George E; Vercammen, Janet M; Jiang, Qun; Kelley, Eric E; Kibbe, Melina R

    2015-01-30

    Superoxide (O2(•-)) promotes neointimal hyperplasia following arterial injury. Conversely, nitric oxide ((•)NO) inhibits neointimal hyperplasia through various cell-specific mechanisms, including redox regulation. What remains unclear is whether (•)NO exerts cell-specific regulation of the vascular redox environment following arterial injury to inhibit neointimal hyperplasia. Therefore, the aim of the present study was to assess whether (•)NO exerts cell-specific, differential modulation of O2(•-) levels throughout the arterial wall, establish the mechanism of such modulation, and determine if it regulates (•)NO-dependent inhibition of neointimal hyperplasia. In vivo, (•)NO increased superoxide dismutase-1 (SOD-1) levels following carotid artery balloon injury in a rat model. In vitro, (•)NO increased SOD-1 levels in vascular smooth muscle cells (VSMC), but had no effect on SOD-1 in endothelial cells or adventitial fibroblasts. This SOD-1 increase was associated with an increase in sod1 gene expression, increase in SOD-1 activity, and decrease in O2(•-) levels. Lastly, to determine the role of SOD-1 in (•)NO-mediated inhibition of neointimal hyperplasia, we performed the femoral artery wire injury model in wild type and SOD-1 knockout (KO) mice, with and without (•)NO. Interestingly, (•)NO inhibited neointimal hyperplasia only in wild type mice, with no effect in SOD-1 KO mice. In conclusion, these data show the cell-specific modulation of O2(•-) by (•)NO through regulation of SOD-1 in the vasculature, highlighting its importance on the inhibition of neointimal hyperplasia. These results also shed light into the mechanism of (•)NO-dependent redox balance, and suggest a novel VSMC redox target to prevent neointimal hyperplasia.

  9. GABAA receptor-mediated feedforward and feedback inhibition differentially modulate the gain and the neural code transformation in hippocampal CA1 pyramidal cells.

    PubMed

    Jang, Hyun Jae; Park, Kyerl; Lee, Jaedong; Kim, Hyuncheol; Han, Kyu Hun; Kwag, Jeehyun

    2015-12-01

    Diverse variety of hippocampal interneurons exists in the CA1 area, which provides either feedforward (FF) or feedback (FB) inhibition to CA1 pyramidal cell (PC). However, how the two different inhibitory network architectures modulate the computational mode of CA1 PC is unknown. By investigating the CA3 PC rate-driven input-output function of CA1 PC using in vitro electrophysiology, in vitro-simulation of inhibitory network, and in silico computational modeling, we demonstrated for the first time that GABAA receptor-mediated FF and FB inhibition differentially modulate the gain, the spike precision, the neural code transformation and the information capacity of CA1 PC. Recruitment of FF inhibition buffered the CA1 PC spikes to theta-frequency regardless of the input frequency, abolishing the gain and making CA1 PC insensitive to its inputs. Instead, temporal variability of the CA1 PC spikes was increased, promoting the rate-to-temporal code transformation to enhance the information capacity of CA1 PC. In contrast, the recruitment of FB inhibition sub-linearly transformed the input rate to spike output rate with high gain and low spike temporal variability, promoting the rate-to-rate code transformation. These results suggest that GABAA receptor-mediated FF and FB inhibitory circuits could serve as network mechanisms for differentially modulating the gain of CA1 PC, allowing CA1 PC to switch between different computational modes using rate and temporal codes ad hoc. Such switch will allow CA1 PC to efficiently respond to spatio-temporally dynamic inputs and expand its computational capacity during different behavioral and neuromodulatory states in vivo.

  10. Can Arousal Modulate Response Inhibition?

    ERIC Educational Resources Information Center

    Weinbach, Noam; Kalanthroff, Eyal; Avnit, Amir; Henik, Avishai

    2015-01-01

    The goal of the present study was to examine if and how arousal can modulate response inhibition. Two competing hypotheses can be drawn from previous literature. One holds that alerting cues that elevate arousal should result in an impulsive response and therefore impair response inhibition. The other suggests that alerting enhances processing of…

  11. Fetal rat lung type II cell differentiation in serum-free isolated cell culture: modulation and inhibition.

    PubMed

    Fraslon, C; Lacaze-Masmonteil, T; Zupan, V; Chailley-Heu, B; Bourbon, J R

    1993-05-01

    Undifferentiated fetal rat lung epithelial cells were isolated on gestational days 15 or 17 (term 22 days) and cultured in a defined medium. On plastic, most of the cells developed structurally abnormal lamellar bodies. On a basement membrane matrix (BMM), they sequentially accumulated glycogen and formed typical lamellar bodies. Biochemical analysis of the latter indicated that they had a phospholipid composition typical of surfactant for cells on BMM but not on plastic and that surfactant protein A appeared on BMM only. Progressing maturation from day 1 to day 6 in culture was demonstrated for 17-day cells on BMM by a sevenfold increase of labeled precursor incorporation into surfactant phospholipids. Exposure to medium conditioned by 21-day fetal fibroblasts enhanced incorporation already after a 1-day culture. The antisteroid RU 486 had no effect on differentiation, whereas transforming growth factor-beta, a factor produced by lung mesenchyme at early fetal stages, inhibited it markedly. Alveolar epithelial type II cells appear to be committed early, but their maturational process would be prevented until a definite gestational stage.

  12. MicroRNA-1 transfected embryonic stem cells enhance cardiac myocyte differentiation and inhibit apoptosis by modulating the PTEN/Akt pathway in the infarcted heart.

    PubMed

    Glass, Carley; Singla, Dinender K

    2011-11-01

    microRNAs (miRs) have emerged as critical modulators of various physiological processes including stem cell differentiation. Indeed, miR-1 has been reported to play an integral role in the regulation of cardiac muscle progenitor cell differentiation. However, whether overexpression of miR-1 in embryonic stem (ES) cells (miR-1-ES cells) will enhance cardiac myocyte differentiation following transplantation into the infarcted myocardium is unknown. In the present study, myocardial infarction (MI) was produced in C57BL/6 mice by left anterior descending artery ligation. miR-1-ES cells, ES cells, or culture medium (control) was transplanted into the border zone of the infarcted heart, and 2 wk post-MI, cardiac myocyte differentiation, adverse ventricular remodeling, and cardiac function were assessed. We provide evidence demonstrating enhanced cardiac myocyte commitment of transplanted miR-1-ES cells in the mouse infarcted heart as compared with ES cells. Assessment of apoptosis revealed that overexpression of miR-1 in transplanted ES cells protected host myocardium from MI-induced apoptosis through activation of p-AKT and inhibition of caspase-3, phosphatase and tensin homolog, and superoxide production. A significant reduction in interstitial and vascular fibrosis was quantified in miR-1-ES cell and ES cell transplanted groups compared with control MI. However, no statistical significance between miR-1-ES cell and ES cell groups was observed. Finally, mice receiving miR-1-ES cell transplantation post-MI had significantly improved heart function compared with respective controls (P < 0.05). Our data suggest miR-1 drives cardiac myocyte differentiation from transplanted ES cells and inhibits apoptosis post-MI, ultimately giving rise to enhanced cardiac repair, regeneration, and function.

  13. Differential modulation of repetitive firing and synchronous network activity in neocortical interneurons by inhibition of A-type K+ channels and Ih

    PubMed Central

    Williams, Sidney B.; Hablitz, John J.

    2015-01-01

    GABAergic interneurons provide the main source of inhibition in the neocortex and are important in regulating neocortical network activity. In the presence 4-aminopyridine (4-AP), CNQX, and D-APV, large amplitude GABAA-receptor mediated depolarizing responses were observed in the neocortex. GABAergic networks are comprised of several types of interneurons, each with its own protein expression pattern, firing properties, and inhibitory role in network activity. Voltage-gated ion channels, especially A-type K+ channels, differentially regulate passive membrane properties, action potential (AP) waveform, and repetitive firing properties in interneurons depending on their composition and localization. HCN channels are known modulators of pyramidal cell intrinsic excitability and excitatory network activity. Little information is available regarding how HCN channels functionally modulate excitability of individual interneurons and inhibitory networks. In this study, we examined the effect of 4-AP on intrinsic excitability of fast-spiking basket cells (FS-BCs) and Martinotti cells (MCs). 4-AP increased the duration of APs in both FS-BCs and MCs. The repetitive firing properties of MCs were differentially affected compared to FS-BCs. We also examined the effect of Ih inhibition on synchronous GABAergic depolarizations and synaptic integration of depolarizing IPSPs. ZD 7288 enhanced the amplitude and area of evoked GABAergic responses in both cell types. Similarly, the frequency and area of spontaneous GABAergic depolarizations in both FS-BCs and MCs were increased in presence of ZD 7288. Synaptic integration of IPSPs in MCs was significantly enhanced, but remained unaltered in FS-BCs. These results indicate that 4-AP differentially alters the firing properties of interneurons, suggesting MCs and FS-BCs may have unique roles in GABAergic network synchronization. Enhancement of GABAergic network synchronization by ZD 7288 suggests that HCN channels attenuate inhibitory

  14. D1 and D2 Inhibitions of the Soleus H-Reflex Are Differentially Modulated during Plantarflexion Force and Position Tasks

    PubMed Central

    Magalhães, Fernando Henrique; Elias, Leonardo Abdala; da Silva, Cristiano Rocha; de Lima, Felipe Fava; de Toledo, Diana Rezende; Kohn, André Fabio

    2015-01-01

    Presynaptic inhibition (PSI) has been shown to modulate several neuronal pathways of functional relevance by selectively gating the connections between sensory inputs and spinal motoneurons, thereby regulating the contribution of the stretch reflex circuitry to the ongoing motor activity. In this study, we investigated whether a differential regulation of Ia afferent inflow by PSI may be associated with the performance of two types of plantarflexion sensoriomotor tasks. The subjects (in a seated position) controlled either: 1) the force level exerted by the foot against a rigid restraint (force task, FT); or 2) the angular position of the ankle when sustaining inertial loads (position task, PT) that required the same level of muscle activation observed in FT. Subjects were instructed to maintain their force/position at target levels set at ~10% of maximum isometric voluntary contraction for FT and 90° for PT, while visual feedback of the corresponding force/position signals were provided. Unconditioned H-reflexes (i.e. control reflexes) and H-reflexes conditioned by electrical pulses applied to the common peroneal nerve with conditioning-to-test intervals of 21 ms and 100 ms (corresponding to D1 and D2 inhibitions, respectively) were evoked in a random fashion. A significant main effect for the type of the motor task (FT vs PT) (p = 0.005, η2p = 0.603) indicated that PTs were undertaken with lower levels of Ia PSI converging onto the soleus motoneuron pool. Additionally, a significant interaction between the type of inhibition (D1 vs D2) and the type of motor task (FT vs PT) (p = 0.038, η2p = 0.395) indicated that D1 inhibition was associated with a significant reduction in PSI levels from TF to TP (p = 0.001, η2p = 0.731), whereas no significant difference between the tasks was observed for D2 inhibition (p = 0.078, η2p = 0.305). These results suggest that D1 and D2 inhibitions of the soleus H-reflex are differentially modulated during the performance of

  15. HDAC I inhibition in the dorsal and ventral hippocampus differentially modulates predator-odor fear learning and generalization

    PubMed Central

    Yuan, Robin K.; Hebert, Jenna C.; Thomas, Arthur S.; Wann, Ellen G.; Muzzio, Isabel A.

    2015-01-01

    Although predator odors are ethologically relevant stimuli for rodents, the molecular pathways and contribution of some brain regions involved in predator odor conditioning remain elusive. Inhibition of histone deacetylases (HDACs) in the dorsal hippocampus has been shown to enhance shock-induced contextual fear learning, but it is unknown if HDACs have differential effects along the dorso-ventral hippocampal axis during predator odor fear learning. We injected MS-275, a class I HDAC inhibitor, bilaterally in the dorsal or ventral hippocampus of mice and found that it had no effects on innate anxiety in either region. We then assessed the effects of MS-275 at different stages of fear learning along the longitudinal hippocampal axis. Animals were injected with MS-275 or vehicle after context pre-exposure (pre-conditioning injections), when a representation of the context is first formed, or after exposure to coyote urine (post-conditioning injections), when the context becomes associated with predator odor. When MS-275 was administered after context pre-exposure, dorsally injected animals showed enhanced fear in the training context but were able to discriminate it from a neutral environment. Conversely, ventrally injected animals did not display enhanced learning in the training context but generalized the fear response to a neutral context. However, when MS-275 was administered after conditioning, there were no differences between the MS-275 and vehicle control groups in either the dorsal or ventral hippocampus. Surprisingly, all groups displayed generalization to a neutral context, suggesting that predator odor exposure followed by a mild stressor such as restraint leads to fear generalization. These results may elucidate distinct functions of the dorsal and ventral hippocampus in predator odor-induced fear conditioning as well as some of the molecular mechanisms underlying fear generalization. PMID:26441495

  16. Alpha-amylase and alpha-glucosidase inhibition is differentially modulated by fucoidan obtained from Fucus vesiculosus and Ascophyllum nodosum.

    PubMed

    Kim, Kyung-Tae; Rioux, Laurie-Eve; Turgeon, Sylvie L

    2014-02-01

    Fucoidan is a water-soluble, negatively charged, biologically active polysaccharide found in great abundance in brown marine algae. However, the inhibition of α-amylase and α-glucosidase by fucoidan derived from two algal species (Ascophyllum nodosum and Fucus vesiculosus) harvested at different periods (accounting for seasonal and yearly variations) has never been investigated. It was found that fucoidans inhibited α-glucosidase differently, depending on the algal species from which it was extracted and the algae's season of harvest. Fucoidan extracted from A. nodosum was a more potent inhibitor of α-glucosidase, with an IC50 ranging from 0.013 to 0.047 mg/mL, than the inhibition by fucoidan extracted from F. vesiculosus (IC50=0.049 mg/mL). In contrast, fucoidan extracted from F. vesiculosus did not inhibit α-amylase activity, while fucoidan from A. nodosum decreased α-amylase activity by 7-100% at 5 mg/mL depending upon the algae harvest period. An IC50 of 0.12-4.64 mg/mL for fucoidan from A. nodosum was found for the α-amylase inhibition. The ability of fucoidan to inhibit α-amylase and α-glucosidase thus varies according to the algae species and harvest period. A. nodosum is more suitable than F. vesiculosus as a source of fucoidan to inhibit α-amylase and α-glucosidase activities. Their potential benefits towards Type 2 diabetes management should be further investigated.

  17. 1,10-phenanthroline inhibits the metallopeptidase secreted by Phialophora verrucosa and modulates its growth, morphology and differentiation.

    PubMed

    Granato, Marcela Queiroz; Massapust, Priscila de Araújo; Rozental, Sonia; Alviano, Celuta Sales; dos Santos, André Luis Souza; Kneipp, Lucimar Ferreira

    2015-04-01

    Phialophora verrucosa is one of the etiologic agents of chromoblastomycosis, a fungal infection that affects cutaneous and subcutaneous tissues. This disease is chronic, recurrent and difficult to treat. Several studies have shown that secreted peptidases by fungi are associated with important pathophysiological processes. Herein, we have identified and partially characterized the peptidase activity secreted by P. verrucosa conidial cells. Using human serum albumin as substrate, the best hydrolysis profile was detected at extreme acidic pH (3.0) and at 37 °C. The enzymatic activity was completely blocked by classical metallopeptidase inhibitors/chelating agents as 1,10-phenanthroline and EGTA. Zinc ions stimulated the metallo-type peptidase activity in a dose-dependent manner. Several proteinaceous substrates were cleaved, in different extension, by the P. verrucosa metallopeptidase activity, including immunoglobulin G, fibrinogen, collagen types I and IV, fibronectin, laminin and keratin; however, mucin and hemoglobin were not susceptible to proteolysis. As metallopeptidases participate in different cellular metabolic pathways in fungal cells, we also tested the influence of 1,10-phenanthroline and EGTA on P. verrucosa development. Contrarily to EGTA, 1,10-phenanthroline inhibited the fungal viability (MIC 0.8 µg/ml), showing fungistatic effect, and induced profound morphological alterations as visualized by transmission electron microscopy. In addition, 1,10-phenanthroline arrested the filamentation process in P. verrucosa. Our results corroborate the supposition that metallopeptidase inhibitors/chelating agents have potential to control crucial biological events in fungal agents of chromoblastomycosis.

  18. Saw palmetto ethanol extract inhibits adipocyte differentiation.

    PubMed

    Villaverde, Nicole; Galvis, Adriana; Marcano, Adriana; Priestap, Horacio A; Bennett, Bradley C; Barbieri, M Alejandro

    2013-07-01

    The fruits of saw palmetto have been used for the treatment of a variety of urinary and reproductive system problems. In this study we investigated whether the fruit extracts affect in vitro adipogenesis. Saw palmetto ethanol extract inhibited the lipid droplet accumulation by induction media in a dose-dependent manner, and it also attenuated the protein expressions of C-EBPα and PPARγ. Phosphorylation of Erk1/2 and Akt1 were also decreased by saw palmetto ethanol extract. This report suggests that saw palmetto extracts selectively affect the adipocyte differentiation through the modulation of several key factors that play a critical role during adipogenesis.

  19. Low-voltage differentially-signaled modulators

    SciTech Connect

    Zortman, William A.; Lentine, Anthony L.; Hsia, Alexander H.; Watts, Michael R.

    2015-09-08

    Photonic modulators and methods of modulating an input optical signal are provided. A photonic modulator includes at least one modulator section and differential drive circuitry. The at least one modulator section includes a P-type layer and an N-type layer forming a PN junction in the modulator section. The differential drive circuitry is electrically coupled to the P-type layer and the N-type layer of the at least one modulator section.

  20. Using structural-based protein engineering to modulate the differential inhibition effects of SAUGI on human and HSV uracil DNA glycosylase.

    PubMed

    Wang, Hao-Ching; Ho, Chun-Han; Chou, Chia-Cheng; Ko, Tzu-Ping; Huang, Ming-Fen; Hsu, Kai-Cheng; Wang, Andrew H-J

    2016-05-19

    Uracil-DNA glycosylases (UDGs) are highly conserved proteins that can be found in a wide range of organisms, and are involved in the DNA repair and host defense systems. UDG activity is controlled by various cellular factors, including the uracil-DNA glycosylase inhibitors, which are DNA mimic proteins that prevent the DNA binding sites of UDGs from interacting with their DNA substrate. To date, only three uracil-DNA glycosylase inhibitors, phage UGI, p56, and Staphylococcus aureus SAUGI, have been determined. We show here that SAUGI has differential inhibitory effects on UDGs from human, bacteria, Herpes simplex virus (HSV; human herpesvirus 1) and Epstein-Barr virus (EBV; human herpesvirus 4). Newly determined crystal structures of SAUGI/human UDG and a SAUGI/HSVUDG complex were used to explain the differential binding activities of SAUGI on these two UDGs. Structural-based protein engineering was further used to modulate the inhibitory ability of SAUGI on human UDG and HSVUDG. The results of this work extend our understanding of DNA mimics as well as potentially opening the way for novel therapeutic applications for this kind of protein.

  1. Differential Muscarinic Modulation in the Olfactory Bulb

    PubMed Central

    Smith, Richard S.; Hu, Ruilong; DeSouza, Andre; Eberly, Christian L.; Krahe, Krista; Chan, Wilson

    2015-01-01

    Neuromodulation of olfactory circuits by acetylcholine (ACh) plays an important role in odor discrimination and learning. Early processing of chemosensory signals occurs in two functionally and anatomically distinct regions, the main and accessory olfactory bulbs (MOB and AOB), which receive extensive cholinergic input from the basal forebrain. Here, we explore the regulation of AOB and MOB circuits by ACh, and how cholinergic modulation influences olfactory-mediated behaviors in mice. Surprisingly, despite the presence of a conserved circuit, activation of muscarinic ACh receptors revealed marked differences in cholinergic modulation of output neurons: excitation in the AOB and inhibition in the MOB. Granule cells (GCs), the most abundant intrinsic neuron in the OB, also exhibited a complex muscarinic response. While GCs in the AOB were excited, MOB GCs exhibited a dual muscarinic action in the form of a hyperpolarization and an increase in excitability uncovered by cell depolarization. Furthermore, ACh influenced the input–output relationship of mitral cells in the AOB and MOB differently showing a net effect on gain in mitral cells of the MOB, but not in the AOB. Interestingly, despite the striking differences in neuromodulatory actions on output neurons, chemogenetic inhibition of cholinergic neurons produced similar perturbations in olfactory behaviors mediated by these two regions. Decreasing ACh in the OB disrupted the natural discrimination of molecularly related odors and the natural investigation of odors associated with social behaviors. Thus, the distinct neuromodulation by ACh in these circuits could underlie different solutions to the processing of general odors and semiochemicals, and the diverse olfactory behaviors they trigger. SIGNIFICANCE STATEMENT State-dependent cholinergic modulation of brain circuits is critical for several high-level cognitive functions, including attention and memory. Here, we provide new evidence that cholinergic

  2. Silicate modulates the cross-talk between osteoblasts (SaOS-2) and osteoclasts (RAW 264.7 cells): inhibition of osteoclast growth and differentiation.

    PubMed

    Schröder, H C; Wang, X H; Wiens, M; Diehl-Seifert, B; Kropf, K; Schloßmacher, U; Müller, W E G

    2012-10-01

    It has been shown that inorganic monomeric and polymeric silica/silicate, in the presence of the biomineralization cocktail, increases the expression of osteoprotegerin (OPG) in osteogenic SaOS-2 sarcoma cells in vitro. In contrast, silicate does not affect the steady-state gene expression level of the osteoclastogenic ligand receptor activator of NF-κB ligand (RANKL). In turn it can be expected that the concentration ratio of the mediators OPG/RANKL increases in the presence of silicate. In addition, silicate enhances the growth potential of SaOS-2 cells in vitro, while it causes no effect on RAW 264.7 cells within a concentration range of 10-100 µM. Applying a co-cultivation assay system, using SaOS-2 cells and RAW 264.7 cells, it is shown that in the presence of 10 µM silicate the number of RAW 264.7 cells in general, and the number of TRAP(+) RAW 264.7 cells in particular markedly decreases. The SaOS-2 cells retain their capacity of differential gene expression of OPG and RANKL in favor of OPG after exposure to silicate. It is concluded that after exposure of the cells to silicate a factor(s) is released from SaOS-2 cells that causes a significant inhibition of osteoclastogenesis of RAW 264.7 cells. It is assumed that it is an increased secretion of the cytokine OPG that is primarily involved in the reduction of the osteoclastogenesis of the RAW 264.7 cells. It is proposed that silicate might have the potential to stimulate osteogenesis in vivo and perhaps to ameliorate osteoporotic disorders.

  3. mTOR and MEK1/2 inhibition differentially modulate tumor growth and the immune microenvironment in syngeneic models of oral cavity cancer

    PubMed Central

    Cash, Harrison; Shah, Sujay; Moore, Ellen; Caruso, Andria; Uppaluri, Ravindra; Van Waes, Carter; Allen, Clint

    2015-01-01

    We investigated the effects of mTOR and MEK1/2 inhibition on tumor growth and the tumor microenvironment in immunogenic and poorly immunogenic models of murine oral cancer. In vitro, rapamycin and PD901 inhibited signaling through expected downstream targets, but only PD901 reduced viability and altered function of MOC cells. Following transplantation of MOC cells into immune-competent mice, effects on both cancer and infiltrating immune cells were characterized following rapamycin and/or PD901 treatment for 21 days. In vivo, both rapamycin and PD901 inhibition reduced primary growth of established MOC tumors on treatment. Following withdrawal of PD901, rapid rebound of tumor growth limited survival, whereas durable tumor control was observed following rapamycin treatment in immunogenic MOC1 tumors despite more robust inhibition of oncogenic signaling by PD901. Characterization of the immune microenvironment revealed diminished infiltration and activation of antigen-specific CD8+ T-cells and other immune cells following PD901 but not rapamycin in immunogenic tumors. Subsequent in vitro T-cell assays validated robust inhibition of T-cell expansion and activation following MEK inhibition compared to mTOR inhibition. CD8 cell depletion abrogated rapamycin-induced primary tumor growth inhibition in MOC1 mice. These data have critical implications in the design of combination targeted and immune therapies in oral cancer. PMID:26506415

  4. BROMODICHLOROMETHANE INHIBITS HUMAN PLACENTAL TROPHOBLAST DIFFERENTIATION

    EPA Science Inventory

    BROMODICHLOROMETHANE INHIBITS HUMAN PLACENTAL
    TROPHOBLAST DIFFERENTIATION
    Jiangang Chen, Twanda L. Thirkill, Peter N. Lohstroh, Susan R. Bielmeier, Michael
    G. Narotsky, Deborah S. Best, Randy A. Harrison, Kala Natarajan, Rex A. Pegram,
    Bill L. Lasley, and Gordon C. Do...

  5. Inhibition of osteogenic differentiation of human mesenchymal stem cells

    PubMed Central

    Moioli, Eduardo K.; Hong, Liu; Mao, Jeremy J.

    2010-01-01

    Mesenchymal stem cells (hMSCs) have been shown to differentiate into osteoblasts that, in turn, are capable of forming tissues analogous to bone. The present study was designed to investigate the inhibition of osteogenesis by hMSCs. Bone marrow-derived hMSCs were treated with transforming growth factor β-3 (TGFβ3) at various doses during or after their differentiation into osteogenic cells. TGFβ3 was encapsulated in poly(DL-lactic-co-glycolic acid) (PLGA) microspheres and released via controlled delivery in the osteogenic culture of hMSCs and hMSC-derived osteoblasts for up to 28 days. Controlled release of TGFβ3 inhibited the osteogenic differentiation of hMSCs, as evidenced by significantly reduced alkaline phosphatase activity and staining, as well as decreased mineral deposition. After hMSCs had been differentiated into osteoblasts, controlled release of TGFβ3 further inhibited not only alkaline phosphatase and mineral deposition but also osteocalcin expression. These findings demonstrate the potential for sustained modulation of the behavior of stem cells and/or stem cell-derived lineage-specific cells via controlled release of growth factor(s). The attenuation of osteogenic differentiation of MSCs may facilitate understanding not only the regulation and patterning of osteogenesis in development but also several pathological models such as osteopetrosis, craniosynostosis, and heart valve calcification. PMID:17537129

  6. Modulation of TGFβ1-Dependent Myofibroblast Differentiation by Hyaluronan

    PubMed Central

    Webber, Jason; Jenkins, Robert H.; Meran, Soma; Phillips, Aled; Steadman, Robert

    2009-01-01

    Myofibroblasts are contractile cells that are characterized by the expression of α-smooth muscle actin and mediate the closure of wounds and the formation of collagen-rich scars. Their presence in organs such as lungs, liver, and kidney has long been established as a marker of progressive fibrosis. The transforming growth factor beta1-driven differentiation of fibroblasts is a major source of myofibroblasts, and recent data have shown that hyaluronan is a major modulator of this process. This study examines this differentiation mechanism in more detail. Transforming growth factor beta1-dependent differentiation to the myofibroblastic phenotype was antagonized by the inhibition of hyaluronan synthesis, confirming that hyaluronan was necessary for differentiation. This response, however, was not reproduced by simply adding hyaluronan to fibroblasts, as the results implicated hyaladherins, as well as the macromolecular assembly of de novo hyaluronan, as essential in this process. We previously suggested that there is a relocalization of lipid-raft components during myofibroblastic differentiation. The present study demonstrates that the hyaluronan receptor CD44, the hyaluronidase HYAL 2, and the transforming growth factor beta1-receptor ALK5 all relocalized from raft to non-raft locations, which was reversed by the addition of exogenous hyaluronan. These data highlight a role for endogenous hyaluronan in the mediation of myofibroblastic differentiation. While hyaluronan synthesis was both essential and necessary for differentiation, exogenously provided hyaluronan antagonized differentiation, underscoring a pathological role for hyaluronan in such cell fate processes. PMID:19541937

  7. Dendritic cell MST1 inhibits Th17 differentiation

    PubMed Central

    Li, Chunxiao; Bi, Yujing; Li, Yan; Yang, Hui; Yu, Qing; Wang, Jian; Wang, Yu; Su, Huilin; Jia, Anna; Hu, Ying; Han, Linian; Zhang, Jiangyuan; Li, Simin; Tao, Wufan; Liu, Guangwei

    2017-01-01

    Although the differentiation of CD4+T cells is widely studied, the mechanisms of antigen-presenting cell-dependent T-cell modulation are unclear. Here, we investigate the role of dendritic cell (DC)-dependent T-cell differentiation in autoimmune and antifungal inflammation and find that mammalian sterile 20-like kinase 1 (MST1) signalling from DCs negatively regulates IL-17 producing-CD4+T helper cell (Th17) differentiation. MST1 deficiency in DCs increases IL-17 production by CD4+T cells, whereas ectopic MST1 expression in DCs inhibits it. Notably, MST1-mediated DC-dependent Th17 differentiation regulates experimental autoimmune encephalomyelitis and antifungal immunity. Mechanistically, MST1-deficient DCs promote IL-6 secretion and regulate the activation of IL-6 receptor α/β and STAT3 in CD4+T cells in the course of inducing Th17 differentiation. Activation of the p38 MAPK signal is responsible for IL-6 production in MST1-deficient DCs. Thus, our results define the DC MST1–p38MAPK signalling pathway in directing Th17 differentiation. PMID:28145433

  8. Asiatic acid inhibits adipogenic differentiation of bone marrow stromal cells.

    PubMed

    Li, Zheng-Wei; Piao, Cheng-dong; Sun, Hong-hui; Ren, Xian-Sheng; Bai, Yun-Shen

    2014-03-01

    Bone marrow mesenchymal stromal cells (BMSCs) are the common precursors for both osteoblasts and adipocytes. With aging, BMSC osteoblast differentiation decreases whereas BMSC differentiation into adipocytes increases, resulting in increased adipogenesis and bone loss. In the present study, we investigated the effect of asiatic acid (AA) on adipocytic differentiation of BMSCs. AA inhibited the adipogenic induction of lipid accumulation, activity of glycerol-3-phosphate dehydrogenase, and expression of marker genes in adipogenesis: peroxisome proliferation-activated receptor (PPAR)γ, adipocyte fatty acid-binding protein (ap) 2, and adipsin. Further, we found that AA did not alter clonal expansion rate and expression of C/EBPβ, upstream key regulator of PPARγ, and binding activity of C/EBPβ to PPARγ promoter was not affected by AA as well. These findings suggest that AA may modulate differentiation of BMSCs to cause a lineage shift away from the adipocytes, and inhibition of PPARγ by AA is through C/EBPβ-independent mechanisms. Thus, AA could be a potential candidate for a novel drug against osteoporosis.

  9. Modulation of Oligodendrocyte Differentiation by Mechanotransduction

    PubMed Central

    Lourenço, Tânia; Grãos, Mário

    2016-01-01

    Oligodendrocytes (OLs) are responsible for the myelination of axons in the central nervous system (CNS). The differentiation of OLs encompasses several stages, through which cells undergo dramatic biochemical and morphological changes. OL differentiation is modulated by soluble factors (SFs)—such as growth factors and hormones—, known to be essential for each maturation stage. Besides SFs, insoluble factors such as extracellular matrix (ECM) proteins and other microenvironmental elements also play a pivotal role during OL differentiation. Recently, a growing number of studies were published concerning the effect of biophysical properties of the extracellular milieu on OL differentiation and myelination, showing the importance of ECM stiffness and topography, strain forces and spatial constraints. For instance, it was shown in vitro that OL differentiation and maturation is enhanced by substrates within the reported range of stiffness of the brain and that this effect is potentiated by the presence of merosin, whereas the myelination process is influenced by the diameter of axonal-like fibers. In this mini review article, we will discuss the effect of mechanical cues during OL differentiation and the possible molecular mechanisms involved in such regulation. PMID:27965541

  10. Power Generator with Thermo-Differential Modules

    NASA Technical Reports Server (NTRS)

    Saiz, John R.; Nguyen, James

    2010-01-01

    A thermoelectric power generator consists of an oven box and a solar cooker/solar reflector unit. The solar reflector concentrates sunlight into heat and transfers the heat into the oven box via a heat pipe. The oven box unit is surrounded by five thermoelectric modules and is located at the bottom end of the solar reflector. When the heat is pumped into one side of the thermoelectric module and ejected from the opposite side at ambient temperatures, an electrical current is produced. Typical temperature accumulation in the solar reflector is approximately 200 C (392 F). The heat pipe then transfers heat into the oven box with a loss of about 40 percent. At the ambient temperature of about 20 C (68 F), the temperature differential is about 100 C (180 F) apart. Each thermoelectric module, generates about 6 watts of power. One oven box with five thermoelectric modules produces about 30 watts. The system provides power for unattended instruments in remote areas, such as space colonies and space vehicles, and in polar and other remote regions on Earth.

  11. A Comparator View of Pavlovian and Differential Inhibition

    PubMed Central

    Urcelay, Gonzalo P.; Miller, Ralph R.

    2007-01-01

    In 3 experiments using rats as subjects, the authors varied trial spacing to investigate the conditions under which Pavlovian and differential inhibition are observed. Experiment 1 compared Pavlovian and differential inhibition with spaced training trials. Spaced trials resulted in only the Pavlovian inhibitor passing both summation and retardation tests. Conversely, Experiment 2 compared these 2 types of inhibition with massed training trials. This training resulted in only the differential inhibitor passing both tests for conditioned inhibition. Finally, in Experiment 3 all subjects experienced Pavlovian inhibition training with massed trials. Although this training by itself did not result in behavior indicative of inhibition, subjects that also experienced posttraining extinction of the training context did pass both tests for inhibition. Overall, these results are anticipated by the extended comparator hypothesis (Denniston, Savastano, & Miller, 2001) but are problematic for most contemporary associative learning theories. PMID:16834494

  12. A comparator view of Pavlovian and differential inhibition.

    PubMed

    Urcelay, Gonzalo P; Miller, Ralph R

    2006-07-01

    In 3 experiments using rats as subjects, the authors varied trial spacing to investigate the conditions under which Pavlovian and differential inhibition are observed. Experiment 1 compared Pavlovian and differential inhibition with spaced training trials. Spaced trials resulted in only the Pavlovian inhibitor passing both summation and retardation tests. Conversely, Experiment 2 compared these 2 types of inhibition with massed training trials. This training resulted in only the differential inhibitor passing both tests for conditioned inhibition. Finally, in Experiment 3 all subjects experienced Pavlovian inhibition training with massed trials. Although this training by itself did not result in behavior indicative of inhibition, subjects that also experienced posttraining extinction of the training context did pass both tests for inhibition. Overall, these results are anticipated by the extended comparator hypothesis (Denniston, Savastano, & Miller, 2001) but are problematic for most contemporary associative learning theories.

  13. Pharmacologic inhibition of lactate production prevents myofibroblast differentiation.

    PubMed

    Kottmann, Robert Matthew; Trawick, Emma; Judge, Jennifer L; Wahl, Lindsay A; Epa, Amali P; Owens, Kristina M; Thatcher, Thomas H; Phipps, Richard P; Sime, Patricia J

    2015-12-01

    Myofibroblasts are one of the primary cell types responsible for the accumulation of extracellular matrix in fibrosing diseases, and targeting myofibroblast differentiation is an important therapeutic strategy for the treatment of pulmonary fibrosis. Transforming growth factor-β (TGF-β) has been shown to be an important inducer of myofibroblast differentiation. We previously demonstrated that lactate dehydrogenase and its metabolic product lactic acid are important mediators of myofibroblast differentiation, via acid-induced activation of latent TGF-β. Here we explore whether pharmacologic inhibition of LDH activity can prevent TGF-β-induced myofibroblast differentiation. Primary human lung fibroblasts from healthy patients and those with pulmonary fibrosis were treated with TGF-β and or gossypol, an LDH inhibitor. Protein and RNA were analyzed for markers of myofibroblast differentiation and extracellular matrix generation. Gossypol inhibited TGF-β-induced expression of the myofibroblast marker α-smooth muscle actin (α-SMA) in a dose-dependent manner in both healthy and fibrotic human lung fibroblasts. Gossypol also inhibited expression of collagen 1, collagen 3, and fibronectin. Gossypol inhibited LDH activity, the generation of extracellular lactic acid, and the rate of extracellular acidification in a dose-dependent manner. Furthermore, gossypol inhibited TGF-β bioactivity in a dose-dependent manner. Concurrent treatment with an LDH siRNA increased the ability of gossypol to inhibit TGF-β-induced myofibroblast differentiation. Gossypol inhibits TGF-β-induced myofibroblast differentiation through inhibition of LDH, inhibition of extracellular accumulation of lactic acid, and inhibition of TGF-β bioactivity. These data support the hypothesis that pharmacologic inhibition of LDH may play an important role in the treatment of pulmonary fibrosis.

  14. Pharmacologic inhibition of lactate production prevents myofibroblast differentiation

    PubMed Central

    Kottmann, Robert Matthew; Trawick, Emma; Judge, Jennifer L.; Wahl, Lindsay A.; Epa, Amali P.; Owens, Kristina M.; Phipps, Richard P.

    2015-01-01

    Myofibroblasts are one of the primary cell types responsible for the accumulation of extracellular matrix in fibrosing diseases, and targeting myofibroblast differentiation is an important therapeutic strategy for the treatment of pulmonary fibrosis. Transforming growth factor-β (TGF-β) has been shown to be an important inducer of myofibroblast differentiation. We previously demonstrated that lactate dehydrogenase and its metabolic product lactic acid are important mediators of myofibroblast differentiation, via acid-induced activation of latent TGF-β. Here we explore whether pharmacologic inhibition of LDH activity can prevent TGF-β-induced myofibroblast differentiation. Primary human lung fibroblasts from healthy patients and those with pulmonary fibrosis were treated with TGF-β and or gossypol, an LDH inhibitor. Protein and RNA were analyzed for markers of myofibroblast differentiation and extracellular matrix generation. Gossypol inhibited TGF-β-induced expression of the myofibroblast marker α-smooth muscle actin (α-SMA) in a dose-dependent manner in both healthy and fibrotic human lung fibroblasts. Gossypol also inhibited expression of collagen 1, collagen 3, and fibronectin. Gossypol inhibited LDH activity, the generation of extracellular lactic acid, and the rate of extracellular acidification in a dose-dependent manner. Furthermore, gossypol inhibited TGF-β bioactivity in a dose-dependent manner. Concurrent treatment with an LDH siRNA increased the ability of gossypol to inhibit TGF-β-induced myofibroblast differentiation. Gossypol inhibits TGF-β-induced myofibroblast differentiation through inhibition of LDH, inhibition of extracellular accumulation of lactic acid, and inhibition of TGF-β bioactivity. These data support the hypothesis that pharmacologic inhibition of LDH may play an important role in the treatment of pulmonary fibrosis. PMID:26408551

  15. Inhibition of SLC7A11 by Sulfasalazine Enhances Osteogenic Differentiation of Mesenchymal Stem Cells by Modulating BMP2/4 Expression and Suppresses Bone Loss in Ovariectomized Mice.

    PubMed

    Jin, Chanyuan; Zhang, Ping; Zhang, Min; Zhang, Xiao; Lv, Longwei; Liu, Hao; Liu, Yunsong; Zhou, Yongsheng

    2017-03-01

    An imbalance in osteogenesis and adipogenesis is a crucial pathological factor in the development of osteoporosis. Many attempts have been made to develop drugs to prevent and treat this disease. In the present study, we investigated the phenomenon whereby downregulation of SLC7A11 significantly enhanced the osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro, and promoted the bone formation in vivo. Sulfasalazine (SAS), an inhibitor of SLC7A11, increased the osteogenic potential effectively. Mechanistically, inhibition of SLC7A11 by SAS treatment or knockdown of SLC7A11 increased BMP2/4 expression dramatically. In addition, we detected increased Slc7a11 expression in bone marrow MSCs of ovariectomized (OVX) mice. Remarkably, SAS treatment attenuated bone loss in ovariectomized mice. Together, our data suggested that SAS could be used to treat osteoporosis by enhancing osteogenic differentiation of MSCs. © 2016 American Society for Bone and Mineral Research.

  16. Speech-induced modulation of interhemispheric inhibition.

    PubMed

    Kano, Tadashige; Kobayashi, Masahito; Ohira, Takayuki; Yoshida, Kazunari

    2012-12-07

    This study aimed to determine the effects of speech and mastication on interhemispheric inhibition between the right and left primary motor areas (M1s) by using transcranial magnetic stimulation (TMS). Motor-evoked potentials (MEPs) were recorded from the first dorsal interossei (FDIs) of each hand of 10 healthy right-handed subjects under 3 conditions: at rest (control), during mastication (non-verbal oral movement), and during speech (reading aloud). Test TMS was delivered following conditioning TMS of the contralateral M1 at various interstimulus intervals. Under all conditions, the MEPs in the left FDIs were significantly inhibited after conditioning of the left M1 (i.e. inhibition of the right M1 by TMS of the left hemisphere). In contrast, the left M1 was significantly inhibited by the right hemisphere only during the control and mastication tasks, but not speech task. These results suggest that speech may facilitate the activity of the dominant M1 via functional connectivity between the speech area and the left M1, or may modify the balance of interhemispheric interactions, by suppressing inhibition of the dominant hemisphere by the non-dominant hemisphere. Our findings show a novel aspect of interhemispheric dominance and may improve therapeutic strategies for recovery from stroke.

  17. Contribution of xanthine oxidoreductase to mammary epithelial and breast cancer cell differentiation in part modulates inhibitor of differentiation-1.

    PubMed

    Fini, Mehdi A; Monks, Jenifer; Farabaugh, Susan M; Wright, Richard M

    2011-09-01

    Loss of xanthine oxidoreductase (XOR) has been linked to aggressive breast cancer in vivo and to breast cancer cell aggressiveness in vitro. In the present study, we hypothesized that the contribution of XOR to the development of the normal mammary gland may underlie its capacity to modulate breast cancer. We contrasted in vitro and in vivo developmental systems by differentiation marker and microarray analyses. Human breast cancer microarray was used for clinical outcome studies. The role of XOR in differentiation and proliferation was examined in human breast cancer cells and in a mouse xenograft model. Our data show that XOR was required for functional differentiation of mammary epithelial cells both in vitro and in vivo. Poor XOR expression was observed in a mouse ErbB2 breast cancer model, and pharmacologic inhibition of XOR increased breast cancer tumor burden in mouse xenograft. mRNA microarray analysis of human breast cancer revealed that low XOR expression was significantly associated with time to tumor relapse. The opposing expression of XOR and inhibitor of differentiation-1 (Id1) during HC11 differentiation and mammary gland development suggested a potential functional relationship. While overexpression of Id1 inhibited HC11 differentiation and XOR expression, XOR itself modulated expression of Id1 in differentiating HC11 cells. Overexpression of XOR both inhibited Id1-induced proliferation and -stimulated differentiation of Heregulin-β1-treated human breast cancer cells. These results show that XOR is an important functional component of differentiation whose diminished expression contributes to breast cancer aggressiveness, and they support XOR as both a breast cancer biomarker and a target for pharmacologic activation in therapeutic management of aggressive breast cancer.

  18. Catecholamine differential modulation of PMA and superantigen stimulated lymphocytes

    SciTech Connect

    Downs, M.O.; Johnson, H.M. )

    1991-03-15

    Neurotransmitters have been demonstrated to be important modulators of immune regulation. The authors have previously demonstrated that the catecholamine agonists isoproterenol (Iso), epinephrine (Epi), and norepinephrine (Nor) are potent inhibitors of IFN{gamma} production by phorbol myristate acetate (PMA) stimulated T-cell lymphoma cell line (L12-R4) with the order of potency being Iso > Epi > Nor. Herein, they describe a differential effect of catecholamine influence on staphylococcal enterotoxin A (SEA) stimulated murine splenic cell cultures. Norepinephrine and to a lesser extent Epi can cause a biphasic modulation of IFN{gamma} production. Inhibition of INF{gamma}was seen in the micromolar range while augmentation occurred at the nanomolar range. In light of previous work, these data suggest that {beta}-adrenergic agonist stimulation of antigen presenting cells (APC) may be immunosuppressive while {alpha}-agonist stimulation immunopotentiating. Further, APC may play a central role in determining the net outcome of catecholamine stimulation by being able to mediate signals from both pathways. This response may represent a peripheral neurotransmitter mediated mechanism for fine tuning' immunoreactivity.

  19. Interference with p53 protein inhibits hematopoietic and muscle differentiation

    PubMed Central

    1996-01-01

    The involvement of p53 protein in cell differentiation has been recently suggested by some observations made with tumor cells and the correlation found between differentiation and increased levels of p53. However, the effect of p53 on differentiation is in apparent contrast with the normal development of p53-null mice. To test directly whether p53 has a function in cell differentiation, we interfered with the endogenous wt-p53 protein of nontransformed cells of two different murine histotypes: 32D myeloid progenitors, and C2C12 myoblasts. A drastic inhibition of terminal differentiation into granulocytes or myotubes, respectively, was observed upon expression of dominant- negative p53 proteins. This inhibition did not alter the cell cycle withdrawal typical of terminal differentiation, nor p21(WAF1/CIP1) upregulation, indicating that interference with endogenous p53 directly affects cell differentiation, independently of the p53 activity on the cell cycle. We also found that the endogenous wt-p53 protein of C2C12 cells becomes transcriptionally active during myogenesis, and this activity is inhibited by p53 dominant-negative expression. Moreover, we found that p53 DNA-binding and transcriptional activities are both required to induce differentiation in p53-negative K562 cells. Taken together, these data strongly indicate that p53 is a regulator of cell differentiation and it exerts this role, at least in part, through its transcriptional activity. PMID:8698814

  20. Modulation of motor cortex inhibition during motor imagery.

    PubMed

    Chong, Benjamin W X; Stinear, Cathy M

    2017-04-01

    Motor imagery (MI) is similar to overt movement, engaging common neural substrates and facilitating the corticomotor pathway; however, it does not result in excitatory descending motor output. Transcranial magnetic stimulation (TMS) can be used to assess inhibitory networks in the primary motor cortex via measures of 1-ms short-interval intracortical inhibition (SICI), long-interval intracortical inhibition (LICI), and late cortical disinhibition (LCD). These measures are thought to reflect extrasynaptic GABAA tonic inhibition, postsynaptic GABAB inhibition, and presynaptic GABAB disinhibition, respectively. The behavior of 1-ms SICI, LICI, and LCD during MI has not yet been explored. This study aimed to investigate how 1-ms SICI, LICI, and LCD are modulated during MI and voluntary relaxation (VR) of a target muscle. Twenty-five healthy young adults participated. TMS was used to assess nonconditioned motor evoked potential (MEP) amplitude, 1-ms SICI, 100- (LICI100) and 150-ms LICI, and LCD in the right abductor pollicis brevis (APB) and right abductor digiti minimi during rest, MI, and VR of the hand. Compared with rest, MEP amplitudes were facilitated in APB during MI. SICI was not affected by task or muscle. LICI100 decreased in both muscles during VR but not MI, whereas LCD was recruited in both muscles during both tasks. This indicates that VR modulates postsynaptic GABAB inhibition, whereas both tasks modulate presynaptic GABAB inhibition in a non-muscle-specific way. This study highlights further neurophysiological parallels between actual and imagined movement, which may extend to voluntary relaxation.NEW & NOTEWORTHY This is the first study to investigate how 1-ms short-interval intracortical inhibition, long-interval intracortical inhibition, and late cortical disinhibition are modulated during motor imagery and voluntary muscle relaxation. We present novel findings of decreased 100-ms long-interval intracortical inhibition during voluntary muscle

  1. Modulation of Potassium Channels Inhibits Bunyavirus Infection*

    PubMed Central

    Hover, Samantha; King, Barnabas; Hall, Bradley; Loundras, Eleni-Anna; Taqi, Hussah; Daly, Janet; Dallas, Mark; Peers, Chris; Schnettler, Esther; McKimmie, Clive; Kohl, Alain; Barr, John N.; Mankouri, Jamel

    2016-01-01

    Bunyaviruses are considered to be emerging pathogens facilitated by the segmented nature of their genome that allows reassortment between different species to generate novel viruses with altered pathogenicity. Bunyaviruses are transmitted via a diverse range of arthropod vectors, as well as rodents, and have established a global disease range with massive importance in healthcare, animal welfare, and economics. There are no vaccines or anti-viral therapies available to treat human bunyavirus infections and so development of new anti-viral strategies is urgently required. Bunyamwera virus (BUNV; genus Orthobunyavirus) is the model bunyavirus, sharing aspects of its molecular and cellular biology with all Bunyaviridae family members. Here, we show for the first time that BUNV activates and requires cellular potassium (K+) channels to infect cells. Time of addition assays using K+ channel modulating agents demonstrated that K+ channel function is critical to events shortly after virus entry but prior to viral RNA synthesis/replication. A similar K+ channel dependence was identified for other bunyaviruses namely Schmallenberg virus (Orthobunyavirus) as well as the more distantly related Hazara virus (Nairovirus). Using a rational pharmacological screening regimen, two-pore domain K+ channels (K2P) were identified as the K+ channel family mediating BUNV K+ channel dependence. As several K2P channel modulators are currently in clinical use, our work suggests they may represent a new and safe drug class for the treatment of potentially lethal bunyavirus disease. PMID:26677217

  2. Selective AR Modulators that Distinguish Proliferative from Differentiative Gene Promoters

    DTIC Science & Technology

    2015-08-01

    AWARD NUMBER: W81XWH-14-1-0292 TITLE: Selective AR Modulators that Distinguish Proliferative from Differentiative Gene Promoters PRINCIPAL...30 Jul 2014 - 29 Jul 2015 4. TITLE AND SUBTITLE Selective AR Modulators that Distinguish Proliferative from Differentiative Gene Promoters 5a...differ in androgen response elements (AREs), with genes driving proliferation relying on consensus inverted repeats (cARE) and genes promoting

  3. Wogonin inhibits osteoclast differentiation by inhibiting NFATc1 translocation into the nucleus

    PubMed Central

    GENG, XIAOLIN; YANG, LIBIN; ZHANG, CHAO; QIN, HUA; LIANG, QIUDONG

    2015-01-01

    The aim of the present study was to identify a natural product with the ability to inhibit nuclear factor of activated T cells c1 (NFATc1) translocation from the cytoplasm to the nucleus by high-throughput screening, and to investigate the effect of the natural product upon osteoclast differentiation and its underlying mechanism. An NFATc1 antagonist redistribution assay was performed in U2OS-NFATc1 cells against a natural product library, and Wogonin was found to have the ability to inhibit the NFATc1 translocation from the cytoplasm to the nucleus. The effect of Wogonin on NFATc1 transcription activation was further determined by luciferase assay. An osteoclast differentiation assay was executed to evaluate the effect of Wogonin on osteoclast differentiation. The effect of Wogonin upon the vital genes in osteoclast differentiation was investigated using fluorescent quantitative polymerase chain reaction analysis. The natural product Wogonin significantly inhibited the translocation of NFATc1 from the cytoplasm to the nucleus and its transcriptional activation activity. Wogonin also significantly inhibited osteoclast differentiation and decreased the transcription of osteoclast-associated immunoglobulin-like receptor, tartrate-resistant acid phosphatase and calcitonin receptor. In conclusion, the natural product Wogonin inhibited osteoclast differentiation through the inhibition of NFATc1 translocation from the cytoplasm to the nucleus, and thus the downregulation of genes associated with osteoclast differentiation, which marked Wogonin as a potential treatment for osteoporosis. PMID:26622440

  4. Lipocalin-2 inhibits osteoclast formation by suppressing the proliferation and differentiation of osteoclast lineage cells

    SciTech Connect

    Kim, Hyun-Ju; Yoon, Hye-Jin; Yoon, Kyung-Ae; Gwon, Mi-Ri; Jin Seong, Sook; Suk, Kyoungho; Kim, Shin-Yoon; Yoon, Young-Ran

    2015-06-10

    Lipocalin-2 (LCN2) is a member of the lipocalin superfamily and plays a critical role in the regulation of various physiological processes, such as inflammation and obesity. In this study, we report that LCN2 negatively modulates the proliferation and differentiation of osteoclast precursors, resulting in impaired osteoclast formation. The overexpression of LCN2 in bone marrow-derived macrophages or the addition of recombinant LCN2 protein inhibits the formation of multinuclear osteoclasts. LCN2 suppresses macrophage colony-stimulating factor (M-CSF)-induced proliferation of osteoclast precursor cells without affecting their apoptotic cell death. Interestingly, LCN2 decreases the expression of the M-CSF receptor, c-Fms, and subsequently blocks its downstream signaling cascades. In addition, LCN2 inhibits RANKL-induced osteoclast differentiation and attenuates the expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1), which are important modulators in osteoclastogenesis. Mechanistically, LCN2 inhibits NF-κB signaling pathways, as demonstrated by the suppression of IκBα phosphorylation, nuclear translocation of p65, and NF-κB transcriptional activity. Thus, LCN2 is an anti-osteoclastogenic molecule that exerts its effects by retarding the proliferation and differentiation of osteoclast lineage cells. - Highlights: • LCN2 expression is regulated during osteoclast development. • LCN2 suppresses M-CSF-mediated osteoclast precursor proliferation. • LCN2 inhibits RANKL-induced osteoclast differentiation.

  5. Inhibition of murine erythroleukemia cell differentiation by 3-deazaadenosine.

    PubMed

    Sherman, M L; Shafman, T D; Spriggs, D R; Kufe, D W

    1985-11-01

    Recent studies have demonstrated that 5'-methylthioadenosine, an inhibitor of S-adenosylhomocysteine (AdoHcy) hydrolase, blocks induction of murine erythroleukemia cell (MEL) differentiation. The nucleoside analogue 3-deazaadenosine (c3Ado) is both an efficient substrate and a potent inhibitor of AdoHcy hydrolase. The present study was undertaken to determine whether c3Ado would similarly inhibit MEL differentiation. The results demonstrate that c3Ado inhibits induction of MEL differentiation by dimethyl sulfoxide, hexamethylene bisacetamide, butyric acid, and diazapam. c3Ado blocks the appearance of the differentiated MEL phenotype by inhibiting both MEL heme synthesis and transcription of alpha- and beta-globin RNA. The inhibitory effect of c3Ado on MEL differentiation is concentration dependent, reversible, and potentiated by L-homocysteine thiolactone. Furthermore the AdoHcy/AdoMet ratio increases nearly 3.5-fold after 24 h of treatment with 50 microM c3Ado. In contrast, this c3Ado effect is not associated with polyamine depletion or cytostasis. These findings indicate that c3Ado blocks the induction of MEL differentiation at a transcriptional level and that this effect may be related to inhibition of AdoHcy hydrolase.

  6. DNA methyltransferase inhibitor CDA-II inhibits myogenic differentiation

    SciTech Connect

    Chen, Zirong; Jin, Guorong; Lin, Shuibin; Lin, Xiumei; Gu, Yumei; Zhu, Yujuan; Hu, Chengbin; Zhang, Qingjiong; Wu, Lizi; Shen, Huangxuan

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer CDA-II inhibits myogenic differentiation in a dose-dependent manner. Black-Right-Pointing-Pointer CDA-II repressed expression of muscle transcription factors and structural proteins. Black-Right-Pointing-Pointer CDA-II inhibited proliferation and migration of C2C12 myoblasts. -- Abstract: CDA-II (cell differentiation agent II), isolated from healthy human urine, is a DNA methyltransferase inhibitor. Previous studies indicated that CDA-II played important roles in the regulation of cell growth and certain differentiation processes. However, it has not been determined whether CDA-II affects skeletal myogenesis. In this study, we investigated effects of CDA-II treatment on skeletal muscle progenitor cell differentiation, migration and proliferation. We found that CDA-II blocked differentiation of murine myoblasts C2C12 in a dose-dependent manner. CDA-II repressed expression of muscle transcription factors, such as Myogenin and Mef2c, and structural proteins, such as myosin heavy chain (Myh3), light chain (Mylpf) and MCK. Moreover, CDA-II inhibited C1C12 cell migration and proliferation. Thus, our data provide the first evidence that CDA-II inhibits growth and differentiation of muscle progenitor cells, suggesting that the use of CDA-II might affect skeletal muscle functions.

  7. Personalized Identification of Differentially Expressed Modules in Osteosarcoma

    PubMed Central

    Liu, Xiaozhou; Li, Chengjun; Zhang, Lei; Shi, Xin; Wu, Sujia

    2017-01-01

    Background Osteosarcoma (OS), an aggressive malignant neoplasm, is the most common primary bone cancer mainly in adolescents and young adults. Differentially expressed modules tend to distinguish differences integrally. Identifying modules individually has been crucial for understanding OS mechanisms and applications of custom therapeutic decisions in the future. Material/Methods Samples came from individuals were used from control group (n=15) and OS group (n=84). Based on clique-merging, module-identification algorithm was used to identify modules from OS PPI networks. A novel approach – the individualized module aberrance score (iMAS) was performed to distinguish differences, making special use of accumulated normal samples (ANS). We performed biological process ontology to classify functionally modules. Then Support Vector Machine (SVM) was used to test distribution results of normal and OS group with screened modules. Results We identified 83 modules containing 2084 genes from PPI network in which 61 modules were significantly different. Cluster analysis of OS using the iMAS method identified 5 modules clusters. Specificity=1.00 and Sensitivity=1.00 proved the distribution outcomes of screened modules were mainly consistent with that of total data, which suggested the efficiency of 61 modules. Conclusions We conclude that a novel pipeline that identified the dysregulated modules in individuals of OS. The constructed process is expected to aid in personalized health care, which may present fruitful strategies for medical therapy. PMID:28190021

  8. Differential Modulation of Excitatory and Inhibitory Neurons during Periodic Stimulation

    PubMed Central

    Mahmud, Mufti; Vassanelli, Stefano

    2016-01-01

    Non-invasive transcranial neuronal stimulation, in addition to deep brain stimulation, is seen as a promising therapeutic and diagnostic approach for an increasing number of neurological diseases such as epilepsy, cluster headaches, depression, specific type of blindness, and other central nervous system disfunctions. Improving its effectiveness and widening its range of use may strongly rely on development of proper stimulation protocols that are tailored to specific brain circuits and that are based on a deep knowledge of different neuron types response to stimulation. To this aim, we have performed a simulation study on the behavior of excitatory and inhibitory neurons subject to sinusoidal stimulation. Due to the intrinsic difference in membrane conductance properties of excitatory and inhibitory neurons, we show that their firing is differentially modulated by the wave parameters. We analyzed the behavior of the two neuronal types for a broad range of stimulus frequency and amplitude and demonstrated that, within a small-world network prototype, parameters tuning allow for a selective enhancement or suppression of the excitation/inhibition ratio. PMID:26941602

  9. Differential hemispheric modulation of preparatory attention.

    PubMed

    Fernández, Laura Gabriela; Siéroff, Eric

    2014-06-01

    Preparatory attention (PA) is the ability to allocate attention to a stimulus prior to its occurrence and is a crucial component of attentional control. We investigated the role of brain hemispheres in PA using an experimental test in which normal participants responded to a target that could appear in the right or the left visual fields, thus projecting to the left or the right hemispheres, while ignoring a central distractor that could appear in the preparatory phase preceding the target. This experimental test measures the ability of participants to modulate PA directed to a target location when the probability of a distractor occurrence varies across three blocks of trials (0%, 33%, 67%). The competition between distractors and target for PA should produce slower response times when the probability of distractors is high. Three experiments were conducted varying the temporal predictability of the target occurrence within a trial (high predictability in Experiments 1 and 3, and low predictability in Experiment 2), and the task used (location in Experiments 1 and 2, and detection in Experiment 3). We found that the modulation of PA by the expected probability of events was different in each visual field/hemisphere. Whereas the left hemisphere PA was influenced by the mere probability of events in each block of trials, the right hemisphere PA was mainly influenced by events with high temporal predictability. These results suggest that each hemisphere uses a different strategy to modulate PA when directed to a target location at the perceptual level of visual processing.

  10. Inhibition of JNK promotes differentiation of epidermal keratinocytes.

    PubMed

    Gazel, Alix; Banno, Tomohiro; Walsh, Rebecca; Blumenberg, Miroslav

    2006-07-21

    In inflamed tissue, normal signal transduction pathways are altered by extracellular signals. For example, the JNK pathway is activated in psoriatic skin, which makes it an attractive target for treatment. To define comprehensively the JNK-regulated genes in human epidermal keratinocytes, we compared the transcriptional profiles of control and JNK inhibitor-treated keratinocytes, using DNA microarrays. We identified the differentially expressed genes 1, 4, 24, and 48 h after the treatment with SP600125. Surprisingly, the inhibition of JNK in keratinocyte cultures in vitro induces virtually all aspects of epidermal differentiation in vivo: transcription of cornification markers, inhibition of motility, withdrawal from the cell cycle, stratification, and even production of cornified envelopes. The inhibition of JNK also induces the production of enzymes of lipid and steroid metabolism, proteins of the diacylglycerol and inositol phosphate pathways, mitochondrial proteins, histones, and DNA repair enzymes, which have not been associated with differentiation previously. Simultaneously, basal cell markers, including integrins, hemidesmosome and extracellular matrix components, are suppressed. Promoter analysis of regulated genes finds that the binding sites for the forkhead family of transcription factors are over-represented in the SP600125-induced genes and c-Fos sites in the suppressed genes. The JNK-induced proliferation appears to be secondary to inhibition of differentiation. The results indicate that the inhibition of JNK in epidermal keratinocytes is sufficient to initiate their differentiation program and suggest that augmenting JNK activity could be used to delay cornification and enhance wound healing, whereas attenuating it could be a differentiation therapy-based approach for treating psoriasis.

  11. Cancer cell proliferation is inhibited by specific modulation frequencies

    PubMed Central

    Zimmerman, J W; Pennison, M J; Brezovich, I; Yi, N; Yang, C T; Ramaker, R; Absher, D; Myers, R M; Kuster, N; Costa, F P; Barbault, A; Pasche, B

    2012-01-01

    Background: There is clinical evidence that very low and safe levels of amplitude-modulated electromagnetic fields administered via an intrabuccal spoon-shaped probe may elicit therapeutic responses in patients with cancer. However, there is no known mechanism explaining the anti-proliferative effect of very low intensity electromagnetic fields. Methods: To understand the mechanism of this novel approach, hepatocellular carcinoma (HCC) cells were exposed to 27.12 MHz radiofrequency electromagnetic fields using in vitro exposure systems designed to replicate in vivo conditions. Cancer cells were exposed to tumour-specific modulation frequencies, previously identified by biofeedback methods in patients with a diagnosis of cancer. Control modulation frequencies consisted of randomly chosen modulation frequencies within the same 100 Hz–21 kHz range as cancer-specific frequencies. Results: The growth of HCC and breast cancer cells was significantly decreased by HCC-specific and breast cancer-specific modulation frequencies, respectively. However, the same frequencies did not affect proliferation of nonmalignant hepatocytes or breast epithelial cells. Inhibition of HCC cell proliferation was associated with downregulation of XCL2 and PLP2. Furthermore, HCC-specific modulation frequencies disrupted the mitotic spindle. Conclusion: These findings uncover a novel mechanism controlling the growth of cancer cells at specific modulation frequencies without affecting normal tissues, which may have broad implications in oncology. PMID:22134506

  12. Sox9 potentiates BMP2-induced chondrogenic differentiation and inhibits BMP2-induced osteogenic differentiation.

    PubMed

    Liao, Junyi; Hu, Ning; Zhou, Nian; Lin, Liangbo; Zhao, Chen; Yi, Shixiong; Fan, Tingxu; Bao, Wei; Liang, Xi; Chen, Hong; Xu, Wei; Chen, Cheng; Cheng, Qiang; Zeng, Yongming; Si, Weike; Yang, Zhong; Huang, Wei

    2014-01-01

    Bone morphogenetic protein 2 (BMP2) is one of the key chondrogenic growth factors involved in the cartilage regeneration. However, it also exhibits osteogenic abilities and triggers endochondral ossification. Effective chondrogenesis and inhibition of BMP2-induced osteogenesis and endochondral ossification can be achieved by directing the mesenchymal stem cells (MSCs) towards chondrocyte lineage with chodrogenic factors, such as Sox9. Here we investigated the effects of Sox9 on BMP2-induced chondrogenic and osteogenic differentiation of MSCs. We found exogenous overexpression of Sox9 enhanced the BMP2-induced chondrogenic differentiation of MSCs in vitro. Also, it inhibited early and late osteogenic differentiation of MSCs in vitro. Subcutaneous stem cell implantation demonstrated Sox9 potentiated BMP2-induced cartilage formation and inhibited endochondral ossification. Mouse limb cultures indicated that BMP2 and Sox9 acted synergistically to stimulate chondrocytes proliferation, and Sox9 inhibited BMP2-induced chondrocytes hypertrophy and ossification. This study strongly suggests that Sox9 potentiates BMP2-induced MSCs chondrogenic differentiation and cartilage formation, and inhibits BMP2-induced MSCs osteogenic differentiation and endochondral ossification. Thus, exogenous overexpression of Sox9 in BMP2-induced mesenchymal stem cells differentiation may be a new strategy for cartilage tissue engineering.

  13. Alternative splicing modulates stem cell differentiation.

    PubMed

    Fu, Ru-Huei; Liu, Shih-Ping; Ou, Chen-Wei; Yu, Hsiu-Hui; Li, Kuo-Wei; Tsai, Chang-Hai; Shyu, Woei-Cherng; Lin, Shinn-Zong

    2009-01-01

    Stem cells have the surprising potential to develop into many different cell types. Therefore, major research efforts have focused on transplantation of stem cells and/or derived progenitors for restoring depleted diseased cells in degenerative disorders. Understanding the molecular controls, including alternative splicing, that arise during lineage differentiation of stem cells is crucial for developing stem cell therapeutic approaches in regeneration medicine. Alternative splicing to allow a single gene to encode multiple transcripts with different protein coding sequences and RNA regulatory elements increases genomic complexities. Utilizing differences in alternative splicing as a molecular marker may be more sensitive than simply gene expression in various degrees of stem cell differentiation. Moreover, alternative splicing maybe provide a new concept to acquire induced pluripotent stem cells or promote cell-cell transdifferentiation for restorative therapies and basic medicine researches. In this review, we highlight the recent advances of alternative splicing regulation in stem cells and their progenitors. It will hopefully provide much needed knowledge into realizing stem cell biology and related applications.

  14. Differential modulation of apoptosis and necrosis by antioxidants in immunosuppressed human lymphocytes.

    PubMed

    Rojas, Mauricio; Rugeles, María Teresa; Gil, Diana Patricia; Patiño, Pablo

    2002-04-15

    In the present study, we explored whether mitogenic stimulation of dexamethasone (DXM)- and cyclosporine A (CsA)-immunosuppressed peripheral blood lymphocytes (PBML) induced apoptosis or necrosis and their relation with the production of reactive oxygen intermediates. Our results indicate that both phenomena can occur in these cells and that antioxidants such as N-acetyl cysteine (NAC) and ascorbic acid (AA) can modulate them. However, DXM-induced apoptosis was only partially inhibited by NAC and AA, suggesting that DXM-treated PBMC had an additional apoptotic pathway independent of ROIs. Furthermore, we observed that the inhibition of apoptosis by antioxidants correlated with an increased cell proliferation, suggesting that the immunomodulation of both DXM and CsA may be related to induction of apoptosis. The ability to differentially modulate apoptosis and necrosis by antioxidants opens new possibilities in the management of immunosuppressive therapy, since the inhibition of necrosis may avoid inflammation and the tissue damage associated with immunosuppressors.

  15. Polarization decoherence differential frequency-modulated continuous-wave gyroscope.

    PubMed

    Zheng, Chao; Zheng, Gang; Han, Liwei; Luo, Jianhua; Teng, Fei; Wang, Bing; Song, Ping; Gao, Kun; Hou, Zhiqing

    2014-12-01

    A polarization decoherence differential frequency-modulated continuous-wave (FMCW) gyroscope is presented. The impact of coherent polarization crosstalk noise on the differential FMCW gyro is analyzed. In order to suppress coherent polarization crosstalk noise, a novel method was proposed to produce two incoherent orthogonal polarization narrow band beams from laser diode. In this way, the random drift has been reduced about one order.

  16. Inhibition of astroglia-induced endothelial differentiation by inorganic lead: a role for protein kinase C.

    PubMed Central

    Laterra, J; Bressler, J P; Indurti, R R; Belloni-Olivi, L; Goldstein, G W

    1992-01-01

    Microvascular endothelial function in developing brain is particularly sensitive to lead toxicity, and it has been hypothesized that this results from the modulation of protein kinase C (PKC) by lead. We examined the effects of inorganic lead on an in vitro model of central nervous system endothelial differentiation in which astroglial cells induce central nervous system endothelial cells to form capillary-like structures. Capillary-like structure formation within C6 astroglial-endothelial cocultures was inhibited by lead acetate with 50% maximal inhibition at 0.5 microM total lead. Inhibition was independent of effects on cell viability or growth. Under conditions that inhibited capillary-like structure formation, we found that lead increased membrane-associated PKC in both C6 astroglial and endothelial cells. Prolonged exposure of C6 cells to 5 microM lead for up to 16 h resulted in a time-dependent increase in membranous PKC as determined by immunoblot analysis. Membranous PKC increased after 5-h exposures to as little as 50 nM lead and was maximal at approximately 1 microM. Phorbol esters were used to determine whether PKC modulation was causally related to the inhibition of endothelial differentiation by lead. Phorbol 12-myristate 13-acetate (10 nM) inhibited capillary-like structure formation by 65 +/- 5%, whereas 4 alpha-phorbol 12,13-didecanoate was without effect. These findings suggest that inorganic lead induces cerebral microvessel dysfunction by interfering with PKC modulation in microvascular endothelial or perivascular astroglial cells. Images PMID:1438272

  17. Intracortical modulation, and not spinal inhibition, mediates placebo analgesia.

    PubMed

    Martini, M; Lee, M C H; Valentini, E; Iannetti, G D

    2015-02-01

    Suppression of spinal responses to noxious stimulation has been detected using spinal fMRI during placebo analgesia, which is therefore increasingly considered a phenomenon caused by descending inhibition of spinal activity. However, spinal fMRI is technically challenging and prone to false-positive results. Here we recorded laser-evoked potentials (LEPs) during placebo analgesia in humans. LEPs allow neural activity to be measured directly and with high enough temporal resolution to capture the sequence of cortical areas activated by nociceptive stimuli. If placebo analgesia is mediated by inhibition at spinal level, this would result in a general suppression of LEPs rather than in a selective reduction of their late components. LEPs and subjective pain ratings were obtained in two groups of healthy volunteers - one was conditioned for placebo analgesia while the other served as unconditioned control. Laser stimuli at three suprathreshold energies were delivered to the right hand dorsum. Placebo analgesia was associated with a significant reduction of the amplitude of the late P2 component. In contrast, the early N1 component, reflecting the arrival of the nociceptive input to the primary somatosensory cortex (SI), was only affected by stimulus energy. This selective suppression of late LEPs indicates that placebo analgesia is mediated by direct intracortical modulation rather than inhibition of the nociceptive input at spinal level. The observed cortical modulation occurs after the responses elicited by the nociceptive stimulus in the SI, suggesting that higher order sensory processes are modulated during placebo analgesia.

  18. Dimethylfumarate suppresses adipogenic differentiation in 3T3-L1 preadipocytes through inhibition of STAT3 activity.

    PubMed

    Kang, Hyeon-Ji; Seo, Hyun-Ae; Go, Younghoon; Oh, Chang Joo; Jeoung, Nam Ho; Park, Keun-Gyu; Lee, In-Kyu

    2013-01-01

    The excessive accumulation of adipocytes contributes to the development of obesity and obesity-related diseases. The interactions of several transcription factors, such as C/EBPβ, PPARγ, C/EBPα, Nrf2, and STAT3, are required for adipogenic differentiation. Dimethylfumarate (DMF), an immune modulator and antioxidant, may function as an inhibitor of STAT3 and an activator of Nrf2. This study examined whether DMF inhibits adipogenic differentiation of 3T3-L1 preadipocytes by inhibiting STAT3 or activating Nrf2. DMF suppressed 3T3-L1 preadipocyte differentiation to mature adipocytes in a dose-dependent manner as determined by Oil Red O staining. The mRNA and protein levels of adipogenic genes, including C/EBPβ, C/EBPα, PPARγ, SREBP-1c, FAS, and aP2, were significantly lower in DMF-treated 3T3-L1 preadipocytes. Suppression of adipogenic differentiation by DMF treatment resulted primarily from inhibition of the early stages of differentiation. DMF inhibits clonal expansion during adipogenic differentiation through induction of a G1 cell cycle arrest. Additionally, DMF regulates cell cycle-related proteins, such as p21, pRb, and cyclin D. DMF treatment markedly inhibited differentiation medium-induced STAT3 phosphorylation and inhibited STAT3 transcriptional activation of a reporter construct composed of four synthetic STAT3-response elements. Moreover, inhibition of endogenous Nrf2 activity using a dominant negative Nrf2 did not abolish the DMF-induced inhibition of adipogenic differentiation of 3T3-L1 preadipocytes. In summary, DMF is a negative regulator of adipogenic differentiation based on its regulation of adipogenic transcription factors and cell cycle proteins. This negative regulation by DMF is mediated by STAT3 inhibition, but is unlikely to involve Nrf2 activation.

  19. Module Based Differential Coexpression Analysis Method for Type 2 Diabetes

    PubMed Central

    Yuan, Lin; Zheng, Chun-Hou; Xia, Jun-Feng; Huang, De-Shuang

    2015-01-01

    More and more studies have shown that many complex diseases are contributed jointly by alterations of numerous genes. Genes often coordinate together as a functional biological pathway or network and are highly correlated. Differential coexpression analysis, as a more comprehensive technique to the differential expression analysis, was raised to research gene regulatory networks and biological pathways of phenotypic changes through measuring gene correlation changes between disease and normal conditions. In this paper, we propose a gene differential coexpression analysis algorithm in the level of gene sets and apply the algorithm to a publicly available type 2 diabetes (T2D) expression dataset. Firstly, we calculate coexpression biweight midcorrelation coefficients between all gene pairs. Then, we select informative correlation pairs using the “differential coexpression threshold” strategy. Finally, we identify the differential coexpression gene modules using maximum clique concept and k-clique algorithm. We apply the proposed differential coexpression analysis method on simulated data and T2D data. Two differential coexpression gene modules about T2D were detected, which should be useful for exploring the biological function of the related genes. PMID:26339648

  20. Effects of endocrine modulators on sex differentiation in birds.

    PubMed

    Brunström, Björn; Axelsson, Jeanette; Halldin, Krister

    2003-01-01

    This mini-review focuses on sexual differentiation of the reproductive organs and the brain in birds and the effects of endocrine modulators on these processes. Sex determination in birds is genetically controlled, but the genetic events implicated are largely unknown. Female birds have one Z and one W sex chromosome, while males have two Z sex chromosomes. It is not clear whether it is the presence of the W chromosome in females, the double dose of the Z chromosome in males vis-à-vis females, or both of these characteristics that are crucial for the determination of sex in birds. Oestradiol directs sexual differentiation in birds during critical periods of development. Consequently, exogenous compounds that interfere with the endogenous oestrogen balance can disrupt sexual differentiation of the reproductive organs and the brain. Therefore, sexual differentiation in birds provides a good model for studying the effects of endocrine modulators at various biological levels from gene expression to behaviour. Some compounds known to be present in the environment can alter endocrine function and have adverse effects when administered during development, resulting in alterations in gonads, accessory sexual organs, and behaviour. Data reviewed in this paper are mostly from laboratory studies on endocrine modulators with oestrogenic activity, whereas evidence for adverse effects of pollutants on sexual differentiation in avian wildlife is scarce.

  1. ATF3 represses PPARγ expression and inhibits adipocyte differentiation

    SciTech Connect

    Jang, Min-Kyung; Jung, Myeong Ho

    2014-11-07

    Highlights: • ATF3 decrease the expression of PPARγ and its target gene in 3T3-L1 adipocytes. • ATF3 represses the promoter activity of PPARγ2 gene. • ATF/CRE (−1537/−1530) is critical for ATF3-mediated downregulation of PPARγ. • ATF3 binds to the promoter region containing the ATF/CRE. • ER stress inhibits adipocyte differentiation through downregulation of PPARγ by ATF3. - Abstract: Activating transcription factor 3 (ATF3) is a stress-adaptive transcription factor that mediates cellular stress response signaling. We previously reported that ATF3 represses CCAAT/enhancer binding protein α (C/EBPα) expression and inhibits 3T3-L1 adipocyte differentiation. In this study, we explored potential role of ATF3 in negatively regulating peroxisome proliferator activated receptor-γ (PPARγ). ATF3 decreased the expression of PPARγ and its target gene in 3T3-L1 adipocytes. ATF3 also repressed the activity of −2.6 Kb promoter of mouse PPARγ2. Overexpression of PPARγ significantly prevented the ATF3-mediated inhibition of 3T3-L1 differentiation. Transfection studies with 5′ deleted-reporters showed that ATF3 repressed the activity of −2037 bp promoter, whereas it did not affect the activity of −1458 bp promoter, suggesting that ATF3 responsive element is located between the −2037 and −1458. An electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrated that ATF3 binds to ATF/CRE site (5′-TGACGTTT-3′) between −1537 and −1530. Mutation of the ATF/CRE site abrogated ATF3-mediated transrepression of the PPARγ2 promoter. Treatment with thapsigargin, endoplasmic reticulum (ER) stress inducer, increased ATF3 expression, whereas it decreased PPARγ expression. ATF3 knockdown significantly blocked the thapsigargin-mediated downregulation of PPARγ expression. Furthermore, overexpression of PPARγ prevented inhibition of 3T3-L1 differentiation by thapsigargin. Collectively, these results suggest that ATF3-mediated

  2. Green tea polyphenols modulate insulin secretion by inhibiting glutamate dehydrogenase.

    PubMed

    Li, Changhong; Allen, Aron; Kwagh, Jae; Doliba, Nicolai M; Qin, Wei; Najafi, Habiba; Collins, Heather W; Matschinsky, Franz M; Stanley, Charles A; Smith, Thomas J

    2006-04-14

    Insulin secretion by pancreatic beta-cells is stimulated by glucose, amino acids, and other metabolic fuels. Glutamate dehydrogenase (GDH) has been shown to play a regulatory role in this process. The importance of GDH was underscored by features of hyperinsulinemia/hyperammonemia syndrome, where a dominant mutation causes the loss of inhibition by GTP and ATP. Here we report the effects of green tea polyphenols on GDH and insulin secretion. Of the four compounds tested, epigallocatechin gallate (EGCG) and epicatechin gallate were found to inhibit GDH with nanomolar ED(50) values and were therefore found to be as potent as the physiologically important inhibitor GTP. Furthermore, we have demonstrated that EGCG inhibits BCH-stimulated insulin secretion, a process that is mediated by GDH, under conditions where GDH is no longer inhibited by high energy metabolites. EGCG does not affect glucose-stimulated insulin secretion under high energy conditions where GDH is probably fully inhibited. We have further shown that these compounds act in an allosteric manner independent of their antioxidant activity and that the beta-cell stimulatory effects are directly correlated with glutamine oxidation. These results demonstrate that EGCG, much like the activator of GDH (BCH), can facilitate dissecting the complex regulation of insulin secretion by pharmacologically modulating the effects of GDH.

  3. MicroRNA 146 (Mir146) modulates spermatogonial differentiation by retinoic acid in mice.

    PubMed

    Huszar, Jessica M; Payne, Christopher J

    2013-01-01

    Impaired biogenesis of microRNAs disrupts spermatogenesis and leads to infertility in male mice. Spermatogonial differentiation is a key step in spermatogenesis, yet the mechanisms that control this event remain poorly defined. In this study, we discovered microRNA 146 (Mir146) to be highly regulated during spermatogonial differentiation, a process dependent on retinoic acid (RA) signaling. Mir146 transcript levels were diminished nearly 180-fold in differentiating spermatogonia when compared with undifferentiated spermatogonia. Luciferase assays revealed the direct binding of Mir146 to the 3' untranslated region of the mediator complex subunit 1 (Med1), a coregulator of retinoid receptors (RARs and RXRs). Overexpression of Mir146 in cultured undifferentiated spermatogonia reduced Med1 transcript levels, as well as those of differentiation marker kit oncogene (Kit). MED1 protein was also diminished. Conversely, inhibition of Mir146 increased the levels of Kit. When undifferentiated spermatogonia were exposed to RA, Mir146 was downregulated along with a marker for undifferentiated germ cells, zinc finger and BTB domain containing 16 (Zbtb16; Plzf); Kit was upregulated. Overexpression of Mir146 in RA-treated spermatogonia inhibited the upregulation of Kit, stimulated by retinoic acid gene 8 (Stra8), and spermatogenesis- and oogenesis-specific basic helix-loop-helix 2 (Sohlh2). Inhibition of Mir146 in RA-treated spermatogonia greatly enhanced the upregulation of these genes. We conclude that Mir146 modulates the effects of RA on spermatogonial differentiation.

  4. Sorafenib inhibition of Mcl-1 accelerates ATRA induced apoptosis in differentiation responsive AML cells

    PubMed Central

    Wang, Rui; Xia, Lijuan; Gabrilove, Janice; Waxman, Samuel; Jing, Yongkui

    2015-01-01

    Purpose All trans retinoic acid (ATRA) is successful in treating acute promyelocytic leukemia (APL) by inducing terminal differentiation-mediated cell death, but it has limited activity in non-APL acute myeloid leukemia (AML). We aim to improve ATRA therapy of AML by enhancing apoptosis through repression of the anti-apoptotic proteins Bcl-2 and Mcl-1. Experimental Design APL and AML cell lines, as well as primary AML samples, were used to explore the mechanisms regulating differentiation and apoptosis during ATRA treatment. Stable transfection and gene silencing with siRNA were used to identify the key factors that inhibit apoptosis during induction of differentiation and drugs that accelerate apoptosis. Results In differentiation responsive AML cells, ATRA treatment induces long-lasting repression of Bcl-2 while first up-modulating and then reducing the Mcl-1 level. The Mcl-1 level appears to serve as a gatekeeper between differentiation and apoptosis. During differentiation induction, activation of MEK/ERK and PI3K/Akt pathways by ATRA leads to activation of p90RSK and inactivation of glycogen synthase kinase 3β (GSK3β), which increase Mcl-1 levels by increasing its translation and stability. Sorafenib blocks ATRA-induced Mcl-1 increase by reversing p90RSK activation and GSK3β inactivation, maintains the repressed Bcl-2 level, and enhances ATRA induced apoptosis in non-APL AML cell lines and in primary AML cells. Conclusion Inhibition of Mcl-1 is required for apoptosis induction in ATRA differentiation responsive AML cells. ATRA and Sorafenib can be developed as a novel drug combination therapy for AML patients because this drug combination augments apoptosis by inhibiting Bcl-2 and Mcl-1. PMID:26459180

  5. Cell asymmetry correction for temperature modulated differential scanning calorimetry

    SciTech Connect

    Ishikiriyama, K.; Wunderlich, B. |

    1996-12-31

    The quality of measurement of heat capacity by differential scanning calorimetry (DSC) is based on strict symmetry of the twin calorimeter, which is important for temperature-modulated DSC. Heat capacities for sapphire-filled and empty aluminium calorimeters (pans) under designed cell imbalance caused by different pan-masses were measured. In addition, positive and negative signs of asymmetry were explored by analyzing the phase-shift between temperature and heat flow for sapphire and empty runs. The phase shifts change by more than 18{degree} depending on asymmetry sign. Once the asymmetry sign is determined, the asymmetry correction for modulated DSC can be made.

  6. Inducing endoderm differentiation by modulating mechanical properties of soft substrates.

    PubMed

    Jaramillo, Maria; Singh, Satish S; Velankar, Sachin; Kumta, Prashant N; Banerjee, Ipsita

    2015-01-01

    Early embryonic stem cell (ESC) differentiation is marked by the formation of three germ layers from which all tissues types arise. Conventionally, ESCs are differentiated by altering their chemical microenvironment. Recently however, it was established that a mechanical microenvironment can also contribute towards cellular phenotype commitment. In this study, we report how the cellular mechanical microenvironment of soft substrates affects the differentiation and phenotypic commitment of ESCs. Mouse ESCs were cultured in a fibrin hydrogel matrix in 2D and 3D cultures. The gelation characteristics of the substrates were modulated by systematically altering the fibrinogen concentration and the fibrinogen-thrombin crosslinking ratio. Analysis of the ESCs cultured on different substrate conditions clearly illustrated the strong influence that substrate physical characteristics assert on cellular behaviours. Specifically, it was found that ESCs had a higher proliferation rate in gels of lower stiffness. Early differentiation events were studied by analyzing the gene and protein expression levels of early germ layer markers. Our results revealed that lower substrate stiffness elicited stronger upregulation of endoderm related genes Sox17, Afp and Hnf4 compared to stiffer substrates. While both 2D and 3D cultures showed a similar response, the effects were much stronger in 3D culture. These results suggest that physical cues can be used to modulate ESC differentiation into clinically relevant tissues such as liver and pancreas.

  7. Glycinergic transmission modulates GABAergic inhibition in the avian auditory pathway

    PubMed Central

    Fischl, Matthew J.; Burger, R. Michael

    2014-01-01

    For all neurons, a proper balance of synaptic excitation and inhibition is crucial to effect computational precision. Achievement of this balance is remarkable when one considers factors that modulate synaptic strength operate on multiple overlapping time scales and affect both pre- and postsynaptic elements. Recent studies have shown that inhibitory transmitters, glycine and GABA, are co-released in auditory nuclei involved in the computation of interaural time disparities (ITDs), a cue used to process sound source location. The co-release expressed at these synapses is heavily activity dependent, and generally occurs when input rates are high. This circuitry, in both birds and mammals, relies on inhibitory input to maintain the temporal precision necessary for ITD encoding. Studies of co-release in other brain regions suggest that GABA and glycine receptors (GlyRs) interact via cross-suppressive modulation of receptor conductance. We performed in vitro whole-cell recordings in several nuclei of the chicken brainstem auditory circuit to assess whether this cross-suppressive phenomenon was evident in the avian brainstem. We evaluated the effect of pressure-puff applied glycine on synaptically evoked inhibitory currents in nucleus magnocellularis (NM) and the superior olivary nucleus (SON). Glycine pre-application reduced the amplitude of inhibitory postsynaptic currents (IPSCs) evoked during a 100 Hz train stimulus in both nuclei. This apparent glycinergic modulation was blocked in the presence of strychnine. Further experiments showed that this modulation did not depend on postsynaptic biochemical interactions such as phosphatase activity, or direct interactions between GABA and GlyR proteins. Rather, voltage clamp experiments in which we manipulated Cl− flux during agonist application suggest that activation of one receptor will modulate the conductance of the other via local changes in Cl− ion concentration within microdomains of the postsynaptic membrane

  8. Strontium promotes cementoblasts differentiation through inhibiting sclerostin expression in vitro.

    PubMed

    Bao, Xingfu; Liu, Xianjun; Zhang, Yi; Cui, Yue; Yao, Jindan; Hu, Min

    2014-01-01

    Cementogenesis, performed by cementoblasts, is important for the repair of root resorption caused by orthodontic treatment. Based on recent studies, strontium has been applied for osteoporosis treatment due to its positive effect on osteoblasts. Although promising, the effect of strontium on cementoblasts is still unclear. So the aim of this research was to clarify and investigate the effect of strontium on cementogenesis via employing cementoblasts as model. A series of experiments including MTT, alkaline phosphatase activity, gene analysis, alizarin red staining, and western blot were carried out to evaluate the proliferation and differentiation of cementoblasts. In addition, expression of sclerostin was checked to analyze the possible mechanism. Our results show that strontium inhibits the proliferation of cementoblasts with a dose dependent manner; however, it can promote the differentiation of cementoblasts via downregulating sclerostin expression. Taking together, strontium may facilitate cementogenesis and benefit the treatment of root resorption at a low dose.

  9. NGF regulates the expression of axonal LINGO-1 to inhibit oligodendrocyte differentiation and myelination.

    PubMed

    Lee, Xinhua; Yang, Zhongshu; Shao, Zhaohui; Rosenberg, Sheila S; Levesque, Melissa; Pepinsky, R Blake; Qiu, Mengsheng; Miller, Robert H; Chan, Jonah R; Mi, Sha

    2007-01-03

    Neurons and glia share a mutual dependence in establishing a functional relationship, and none is more evident than the process by which axons control myelination. Here, we identify LRR and Ig domain-containing, Nogo receptor-interacting protein (LINGO-1) as a potent axonal inhibitor of oligodendrocyte differentiation and myelination that is regulated by nerve growth factor and its cognate receptor TrkA in a dose-dependent manner. Whereas LINGO-1 expressed by oligodendrocyte progenitor cells was previously identified as an inhibitor of differentiation, we demonstrate that axonal expression of LINGO-1 inhibits differentiation with equal potency. Disruption of LINGO-1 on either cell type is sufficient to overcome the inhibitory action and promote differentiation and myelination, independent of axon diameter. Furthermore, these results were recapitulated in transgenic mice overexpressing the full length LINGO-1 under the neuronal promoter synapsin. Myelination was greatly inhibited in the presence of enforced axonal LINGO-1. The implications of these results relate specifically to the development of potential therapeutics targeting extrinsic growth factors that may regulate the axonal expression of modulators of oligodendrocyte development.

  10. Modulation of the Isoprenoid/Cholesterol Biosynthetic Pathway During Neuronal Differentiation In Vitro.

    PubMed

    Cartocci, Veronica; Segatto, Marco; Di Tunno, Ilenia; Leone, Stefano; Pfrieger, Frank W; Pallottini, Valentina

    2016-09-01

    During differentiation, neurons acquire their typical shape and functional properties. At present, it is unclear, whether this important developmental step involves metabolic changes. Here, we studied the contribution of the mevalonate (MVA) pathway to neuronal differentiation using the mouse neuroblastoma cell line N1E-115 as experimental model. Our results show that during differentiation, the activity of 3-hydroxy 3-methylglutaryl Coenzyme A reductase (HMGR), a key enzyme of MVA pathway, and the level of Low Density Lipoprotein receptor (LDLr) decrease, whereas the level of LDLr-related protein-1 (LRP1) and the dimerization of Scavanger Receptor B1 (SRB-1) rise. Pharmacologic inhibition of HMGR by simvastatin accelerated neuronal differentiation by modulating geranylated proteins. Collectively, our data suggest that during neuronal differentiation, the activity of the MVA pathway decreases and we postulate that any interference with this process impacts neuronal morphology and function. Therefore, the MVA pathway appears as an attractive pharmacological target to modulate neurological and metabolic symptoms of developmental neuropathologies. J. Cell. Biochem. 117: 2036-2044, 2016. © 2016 Wiley Periodicals, Inc.

  11. NLRP3 inflammasome activation in mesenchymal stem cells inhibits osteogenic differentiation and enhances adipogenic differentiation.

    PubMed

    Wang, Linghao; Chen, Ke; Wan, Xinxing; Wang, Fang; Guo, Zi; Mo, Zhaohui

    2017-03-18

    Osteoporosis is one of the most common skeletal disease featured by osteopenia and adipose accumulation in bone tissue. NLRP3 inflammasome activation is an essential player in aging-related chronic diseases like osteoporosis, particularly due to the causal caspase-1 activation and its correlation to adipose accumulation in bone tissue. Moreover, the expression of anti-aging/senescence SIRT1 was reported to decline along with aging. As the major cellular contributor of bone formation, mesenchymal stem cells (MSCs) are multipotent stem cells processing mutually exclusive differentiatability toward osteocytes or adipocytes. Therefore, we hypothesized that NLRP3 inflammasome activation promotes adipogenesis and repress osteogenesis in MSCs via inhibiting SIRT1 expression. We activated NLRP3 inflammasome in human MSCs via lipopolysaccharide and palmitic acid (LPS/PA) treatment for self-renewal maintenance, adipogenic differentiation or osteogenic differentiation. LPS/PA treatment significantly increased NLRP3 expression, decreased SIRT1 expression and promoted caspase-1 activity in MSCs. LPS/PA treatment also boosted adipogenesis of MSCs and suppressed osteogenesis. Moreover, inhibition of caspase-1 activity repressed adipogenic differentiation and partially improved osteogenic differentiation of MSCs with LPS/PA treatment. Our study demonstrated the pivotal roles of NLRP3 inflammasome and downstream mediator caspase-1 for the progress of osteo-differentiation MSCs, and offered novel therapeutic target of treatment for osteoporosis.

  12. Modulation of neuronal differentiation by CD40 isoforms

    SciTech Connect

    Hou Huayu; Obregon, Demian; Lou, Deyan; Ehrhart, Jared; Fernandez, Frank; Silver, Archie; Tan Jun

    2008-05-02

    Neuron differentiation is a complex process involving various cell-cell interactions, and multiple signaling pathways. We showed previously that CD40 is expressed and functional on mouse and human neurons. In neurons, ligation of CD40 protects against serum withdrawal-induced injury and plays a role in survival and differentiation. CD40 deficient mice display neuron dysfunction, aberrant neuron morphologic changes, and associated gross brain abnormalities. Previous studies by Tone and colleagues suggested that five isoforms of CD40 exist with two predominant isoforms expressed in humans: signal-transducible CD40 type I and a C-terminal truncated, non-signal-transducible CD40 type II. We hypothesized that differential expression of CD40 isoform type I and type II in neurons may modulate neuron differentiation. Results show that adult wild-type, and CD40{sup -/-} deficient mice predominantly express CD40 type I and II isoforms. Whereas adult wild-type mice express mostly CD40 type I in cerebral tissues at relatively high levels, in age and gender-matched CD40{sup -/-} mice CD40 type I expression was almost completely absent; suggesting a predominance of the non-signal-transducible CD40 type II isoform. Younger, 1 day old wild-type mice displayed less CD40 type I, and more CD40 type II, as well as, greater expression of soluble CD40 (CD40L/CD40 signal inhibitor), compared with 1 month old mice. Neuron-like N2a cells express CD40 type I and type II isoforms while in an undifferentiated state, however once induced to differentiate, CD40 type I predominates. Further, differentiated N2a cells treated with CD40 ligand express high levels of neuron specific nuclear protein (NeuN); an effect reduced by anti-CD40 type I siRNA, but not by control (non-targeting) siRNA. Altogether these data suggest that CD40 isoforms may act in a temporal fashion to modulate neuron differentiation during brain development. Thus, modulation of neuronal CD40 isoforms and CD40 signaling may

  13. Polymeric membranes modulate human keratinocyte differentiation in specific epidermal layers.

    PubMed

    Salerno, Simona; Morelli, Sabrina; Giordano, Francesca; Gordano, Amalia; Bartolo, Loredana De

    2016-10-01

    In vitro models of human bioengineered skin substitutes are an alternative to animal experimentation for testing the effects and toxicity of drugs, cosmetics and pollutants. For the first time specific and distinct human epidermal strata were engineered by using membranes and keratinocytes. To this purpose, biodegradable membranes of chitosan (CHT), polycaprolactone (PCL) and a polymeric blend of CHT-PCL were prepared by phase-inversion technique and characterized in order to evaluate their morphological, physico-chemical and mechanical properties. The capability of membranes to modulate keratinocyte differentiation inducing specific interactions in epidermal membrane systems was investigated. The overall results demonstrated that the membrane properties strongly influence the cell morpho-functional behaviour of human keratinocytes, modulating their terminal differentiation, with the creation of specific epidermal strata or a fully proliferative epidermal multilayer system. In particular, human keratinocytes adhered on CHT and CHT-PCL membranes, forming the structure of the epidermal top layers, such as the corneum and granulosum strata, characterized by withdrawal or reduction from the cell cycle and cell proliferation. On the PCL membrane, keratinocytes developed an epidermal basal lamina, with high proliferating cells that stratified and migrated over time to form a complete differentiating epidermal multilayer system.

  14. Temporal expectancy modulates inhibition of return in a discrimination task.

    PubMed

    Gabay, Shai; Henik, Avishai

    2010-02-01

    This research examined the influence of cue temporal predictability on inhibition of return (IOR) in a discrimination task. In exogenous attention experiments, the cue that summons attention is noninformative as to where the target will appear. However, it is predictive as to when it will appear. In previous work, it was demonstrated that temporal predictability does not influence IOR in detection tasks. In this work, it is shown that IOR is influenced by temporal predictability in discrimination tasks. Predictability was manipulated by using three stimulus onset asynchrony distributions: nonaging, aging, and accelerated aging. IOR was found when the cue predicted target appearance and was modulated by temporal information. In the nonaging distribution (in which the cue did not predict target appearance), there was no IOR.

  15. Intragenic epigenetic changes modulate NCAM alternative splicing in neuronal differentiation

    PubMed Central

    Schor, Ignacio E; Fiszbein, Ana; Petrillo, Ezequiel; Kornblihtt, Alberto R

    2013-01-01

    Alternative splicing contributes to cell type-specific transcriptomes. Here, we show that changes in intragenic chromatin marks affect NCAM (neural cell adhesion molecule) exon 18 (E18) alternative splicing during neuronal differentiation. An increase in the repressive marks H3K9me2 and H3K27me3 along the gene body correlated with inhibition of polymerase II elongation in the E18 region, but without significantly affecting total mRNA levels. Treatment with the general DNA methylation inhibitor 5-azacytidine and BIX 01294, a specific inhibitor of H3K9 dimethylation, inhibited the differentiation-induced E18 inclusion, pointing to a role for repressive marks in sustaining NCAM splicing patterns typical of mature neurons. We demonstrate that intragenic deployment of repressive chromatin marks, induced by intronic small interfering RNAs targeting NCAM intron 18, promotes E18 inclusion in undifferentiated N2a cells, confirming the chromatin changes observed upon differentiation to be sufficient to induce alternative splicing. Combined with previous evidence that neuronal depolarization causes H3K9 acetylation and subsequent E18 skipping, our results show how two alternative epigenetic marks regulate NCAM alternative splicing and E18 levels in different cellular contexts. PMID:23892457

  16. Intragenic epigenetic changes modulate NCAM alternative splicing in neuronal differentiation.

    PubMed

    Schor, Ignacio E; Fiszbein, Ana; Petrillo, Ezequiel; Kornblihtt, Alberto R

    2013-08-14

    Alternative splicing contributes to cell type-specific transcriptomes. Here, we show that changes in intragenic chromatin marks affect NCAM (neural cell adhesion molecule) exon 18 (E18) alternative splicing during neuronal differentiation. An increase in the repressive marks H3K9me2 and H3K27me3 along the gene body correlated with inhibition of polymerase II elongation in the E18 region, but without significantly affecting total mRNA levels. Treatment with the general DNA methylation inhibitor 5-azacytidine and BIX 01294, a specific inhibitor of H3K9 dimethylation, inhibited the differentiation-induced E18 inclusion, pointing to a role for repressive marks in sustaining NCAM splicing patterns typical of mature neurons. We demonstrate that intragenic deployment of repressive chromatin marks, induced by intronic small interfering RNAs targeting NCAM intron 18, promotes E18 inclusion in undifferentiated N2a cells, confirming the chromatin changes observed upon differentiation to be sufficient to induce alternative splicing. Combined with previous evidence that neuronal depolarization causes H3K9 acetylation and subsequent E18 skipping, our results show how two alternative epigenetic marks regulate NCAM alternative splicing and E18 levels in different cellular contexts.

  17. Uric Acid Promotes Osteogenic Differentiation and Inhibits Adipogenic Differentiation of Human Bone Mesenchymal Stem Cells.

    PubMed

    Li, Hui-Zhang; Chen, Zhi; Hou, Cang-Long; Tang, Yi-Xing; Wang, Fei; Fu, Qing-Ge

    2015-08-01

    To investigate the effect of uric acid on the osteogenic and adipogenic differentiation of human bone mesenchymal stem cells (hBMSCs). The hBMSCs were isolated from bone marrow of six healthy donors. Cell morphology was observed by microscopy and cell surface markers (CD44 and CD34) of hBMSCs were analyzed by immunofluorescence. Cell morphology and immunofluorescence analysis showed that hBMSCs were successfully isolated from bone marrow. The number of hBMSCs in uric acid groups was higher than that in the control group on day 3, 4, and 5. Alizarin red staining showed that number of calcium nodules in uric acid groups was more than that of the control group. Oil red-O staining showed that the number of red fat vacuoles decreased with the increased concentration of uric acid. In summary, uric acid could promote the proliferation and osteogenic differentiation of hBMSCs while inhibit adipogenic differentiation of hBMSCs.

  18. Prepulse inhibition modulation by contextual conditioning of dopaminergic activity.

    PubMed

    Mena, Auxiliadora; De la Casa, Luis G

    2013-09-01

    When a neutral stimulus is repeatedly paired with a drug, an association is established between them that can induce two different responses: either an opponent response that counteracts the effect of the drug, or a response that is similar to that induced by the drug. In this paper, we focus on the analysis of the associations that can be established between the contextual cues and the administration of dopamine agonists or antagonists. Our hypothesis suggests that repeated administration of drugs that modulate dopaminergic activity in the presence of a specific context leads to the establishment of an association that subsequently results in a conditioned response to the context that is similar to that induced by the drug. To test this hypothesis, we conducted two experiments that revealed that contextual cues acquired the property to modulate pre-pulse inhibition by prior pairings of such context with the dopamine antagonist haloperidol (Experiment 1), and with the dopamine agonist d-amphetamine (Experiment 2). The implications of these results are discussed both at a theoretical level, and attending to the possibilities that could involve the use of context cues for the therapeutic administration of dopaminergic drugs.

  19. Acute aerobic exercise modulates primary motor cortex inhibition.

    PubMed

    Mooney, Ronan A; Coxon, James P; Cirillo, John; Glenny, Helen; Gant, Nicholas; Byblow, Winston D

    2016-12-01

    Aerobic exercise can enhance neuroplasticity although presently the neural mechanisms underpinning these benefits remain unclear. One possible mechanism is through effects on primary motor cortex (M1) function via down-regulation of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). The aim of the present study was to examine how corticomotor excitability (CME) and M1 intracortical inhibition are modulated in response to a single bout of moderate intensity aerobic exercise. Ten healthy right-handed adults were participants. Single- and paired-pulse transcranial magnetic stimulation was applied over left M1 to obtain motor-evoked potentials in the right flexor pollicis brevis. We examined CME, cortical silent period (SP) duration, short- and long-interval intracortical inhibition (SICI, LICI), and late cortical disinhibition (LCD), before and after acute aerobic exercise (exercise session) or an equivalent duration without exercise (control session). Aerobic exercise was performed on a cycle ergometer for 30 min at a workload equivalent to 60 % of maximal cardiorespiratory fitness (VO2 peak; heart rate reserve = 75 ± 3 %, perceived exertion = 13.5 ± 0.7). LICI was reduced at 10 (52 ± 17 %, P = 0.03) and 20 min (27 ± 8 %, P = 0.03) post-exercise compared to baseline (13 ± 4 %). No significant changes in CME, SP duration, SICI or LCD were observed. The present study shows that GABAB-mediated intracortical inhibition may be down-regulated after acute aerobic exercise. The potential effects this may have on M1 plasticity remain to be determined.

  20. Differential Occurrence of Reluctant Openings in G-Protein–Inhibited N- and P/Q-Type Calcium Channels

    PubMed Central

    Colecraft, Henry M.; Patil, Parag G.; Yue, David T.

    2000-01-01

    Voltage-dependent inhibition of N- and P/Q-type calcium channels by G proteins is crucial for presynaptic inhibition of neurotransmitter release, and may contribute importantly to short-term synaptic plasticity. Such calcium-channel modulation could thereby impact significantly the neuro-computational repertoire of neural networks. The differential modulation of N and P/Q channels could even further enrich their impact upon synaptic tuning. Here, we performed in-depth comparison of the G-protein inhibition of recombinant N and P/Q channels, expressed in HEK 293 cells with the m2 muscarinic receptor. While both channel types display classic features of G-protein modulation (kinetic slowing of activation, prepulse facilitation, and voltage dependence of inhibition), we confirmed previously reported quantitative differences, with N channels displaying stronger inhibition and greater relief of inhibition by prepulses. A more fundamental, qualitative difference in the modulation of these two channels was revealed by a modified tail-activation paradigm, as well as by a novel “slope” analysis method comparing time courses of slow activation and prepulse facilitation. The stark contrast in modulatory behavior can be understood within the context of the “willing–reluctant” model, in which binding of G-protein βγ subunits to channels induces a reluctant mode of gating, where stronger depolarization is required for opening. Our experiments suggest that only N channels could be opened in the reluctant mode, at voltages normally spanned by neuronal action potentials. By contrast, P/Q channels appear to remain closed, especially over these physiological voltages. Further, the differential occurrence of reluctant openings is not explained by differences in the rate of G-protein unbinding from the two channels. These two scenarios predict very different effects of G-protein inhibition on the waveform of Ca2+ entry during action potentials, with potentially important

  1. MicroRNA-146b promotes myogenic differentiation and modulates multiple gene targets in muscle cells.

    PubMed

    Khanna, Nidhi; Ge, Yejing; Chen, Jie

    2014-01-01

    MicroRNAs are established as crucial modulators of skeletal myogenesis, but our knowledge about their identity and targets remains limited. In this study, we have identified microRNA-146b (miR-146b) as a novel regulator of skeletal myoblast differentiation. Following up on a previous microRNA profiling study, we establish that the expression of miR-146b is up-regulated during myoblast differentiation in vitro and muscle regeneration in vivo. Inhibition of miR-146b led to reduced myoblast differentiation, whereas overexpression of miR-146b enhanced differentiation. Computational prediction combined with gene expression information has revealed candidates for miR-146b targets in muscles. Among them, the expression of Smad4, Notch1, and Hmga2 are significantly suppressed by miR-146b overexpression in myocytes. In addition, expression levels of Smad4, Notch1 and Hmga2 are decreased during myoblast differentiation and muscle regeneration, inversely correlating to the levels of miR-146b. Importantly, inhibition of endogenous miR-146b prevents the down-regulation of Smad4, Notch1 and Hmga2 during differentiation. Furthermore, miR-146b directly targets the microRNA response elements (MREs) in the 3'UTR of those genes as assessed by reporter assays. Reporters with the seed regions of MREs mutated are insensitive to miR-146b, further confirming the specificity of targeting. In conclusion, miR-146b is a positive regulator of myogenic differentiation, possibly acting through multiple targets.

  2. Heparan sulfate proteoglycans including syndecan-3 modulate BMP activity during limb cartilage differentiation.

    PubMed

    Fisher, Melanie C; Li, Yingcui; Seghatoleslami, M Reza; Dealy, Caroline N; Kosher, Robert A

    2006-01-01

    Bone morphogenetic proteins (BMPs) are involved in multiple aspects of limb development including regulation of cartilage differentiation. Several BMPs bind strongly to heparin, and heparan sulfate proteoglycans (HSPGs) at the cell surface or in the extracellular matrix have recently been implicated as modulators of BMP signaling in some developing systems. Here we have explored the role of HSPGs in regulating BMP activity during limb chondrogenesis by evaluating the effects of exogenous heparan sulfate (HS), heparitinase treatment, and overexpression of the HSPG syndecan-3 on the ability of BMP2 to modulate the chondrogenic differentiation of limb mesenchymal cells in micromass culture. Exogenous HS dramatically enhances the ability of BMP2 to stimulate chondrogenesis and cartilage specific gene expression, and reduces the concentration of BMP2 needed to stimulate chondrogenesis. Furthermore, HS stimulates BMP2-mediated phosphorylation of Smad1, Smad5, and Smad8, transcriptional mediators of BMP2 signaling, indicating that HS enhances the interaction of BMP2 with its receptors. Pretreatment of micromass cultures with heparitinase to degrade endogenous HSPGs also enhances the chondrogenic activity of BMP2, and reduces the concentration of BMP2 needed to promote chondrogenesis. Taken together these results indicate that exogenous HS or heparitinase enhance the chondrogenic activity of BMP2 by interfering with its interaction with endogenous HSPGs that would normally restrict its interaction with its receptors. Consistent with the possibility that HSPGs are negative modulators of BMP signaling during chondrogenesis, we have found that overexpression of syndecan-3, which is one of the major HSPGs normally expressed during chondrogenesis, greatly impairs the ability of BMP2 to promote cartilage differentiation. Furthermore, retroviral overexpression of syndecan-3 inhibits BMP2-mediated Smad phosphorylation in the regions of the cultures in which chondrogenesis is

  3. Inhibition of CaMKK2 Stimulates Osteoblast Formation and Inhibits Osteoclast Differentiation

    PubMed Central

    Cary, Rachel L.; Waddell, Seid; Racioppi, Luigi; Long, Fanxin; Novack, Deborah V.; Voor, Michael J.; Sankar, Uma

    2013-01-01

    Bone remodeling, a physiological process characterized by bone formation by osteoblasts (OB) and resorption of pre-existing bone matrix by osteoclasts (OC), is vital for the maintenance of healthy bone tissue in adult humans. Imbalances in this vital process result in pathological conditions including osteoporosis. Owing to its initial asymptomatic nature, osteoporosis is often detected only after the patient has sustained significant bone loss or a fracture. Hence, anabolic therapeutics that stimulates bone accrual is in high clinical demand. Here we identify Ca2+/calmodulin (CaM)-dependent protein kinase kinase 2 (CaMKK2) as a potential target for such therapeutics, as its inhibition enhances OB differentiation and bone growth and suppresses OC differentiation. Mice null for CaMKK2 possess higher trabecular bone mass in their long bones, along with significantly more OBs and fewer multinuclear OCs. Whereas Camkk2−/− MSCs yield significantly higher numbers of OBs, bone marrow cells from Camkk2−/− mice produce fewer multinuclear OCs, in vitro. Acute inhibition of CaMKK2 by its selective, cell-permeable pharmacological inhibitor STO-609 also results in increased OB and diminished OC formation. Further, we find phospho-protein kinase A (PKA) and Ser133 phosphorylated form of cyclic adenosine monophosphate (cAMP) response element binding protein (pCREB) to be markedly elevated in OB progenitors deficient in CaMKK2. On the other hand, genetic ablation of CaMKK2 or its pharmacological inhibition in OC progenitors results in reduced pCREB as well as significantly reduced levels of its transcriptional target, nuclear factor of activated T cells c1 (NFATc1). Moreover, in vivo administration of STO-609 results in increased OBs and diminished OCs, conferring significant protection from ovariectomy (OVX)-induced osteoporosis in adult mice. Overall, our findings reveal a novel function for CaMKK2 in bone remodeling and highlight the potential for its therapeutic

  4. Histamine inhibits differentiation of skin fibroblasts into myofibroblasts.

    PubMed

    Lin, Lin; Yamagata, Kaoru; Nakayamada, Shingo; Sawamukai, Norifumi; Yamaoka, Kunihiro; Sakata, Kei; Nakano, Kazuhisa; Tanaka, Yoshiya

    2015-07-31

    Histamine and TGF-β, major mediators secreted by mast cells, are involved in skin inflammation and play critical roles in the pathogenesis of systemic sclerosis. However, the roles of signaling mechanisms in the development of skin fibrosis remain largely unclear. Here we show that histamine suppressed the expression of α smooth muscle actin (αSMA), a marker of myofibroblasts, induced by TGF-β1 in skin fibroblasts. Histamine H1-receptor (H1R), but not H2-receptor (H2R) or H4-receptor (H4R), was expressed on skin fibroblasts at both mRNA and protein levels. Interestingly, an H1R antagonist, but not H2R or H4R antagonists, antagonized the histamine-mediated suppression of αSMA expression by TGF-β1. Correspondingly, phosphorylated Smad2 was detected after treatment with TGF-β1, whereas the addition of histamine inhibited this phosphorylation. Taken together, histamine-H1R decreased TGF-β1-mediated Smad2 phosphorylation and inhibited differentiation of skin fibroblasts into myofibroblasts.

  5. Inhibition of dipeptidyl peptidase 8/9 impairs preadipocyte differentiation

    PubMed Central

    Han, Ruijun; Wang, Xinying; Bachovchin, William; Zukowska, Zofia; Osborn, John W.

    2015-01-01

    Adipocytes are the primary cells in adipose tissue, and adipocyte dysfunction causes lipodystrophy, obesity and diabetes. The dipeptidyl peptidase (DPP) 4 family includes four enzymes, DPP4, DPP8, DPP9 and fibroblast activation protein (FAP). DPP4 family inhibitors have been used for the treatment of type 2 diabetes patients, but their role in adipocyte formation are poorly understood. Here we demonstrate that the DPP8/9 selective inhibitor 1G244 blocks adipogenesis in preadipocyte 3T3-L1 and 3T3-F422A, while DPP4 and FAP inhibitors have no effect. In addition, knockdown of DPP8 or DPP9 significantly impairs adipocyte differentiation in preadipocytes. We further uncovered that blocking the expression or activities of DPP8 and DPP9 attenuates PPARγ2 induction during preadipocyte differentiation. Addition of PPARγ agonist thiazolidinediones (TZDs), or ectopic expression of PPARγ2, is able to rescue the adipogenic defect caused by DPP8/9 inhibition in preadipocytes. These results indicate the importance of DPP8 and DPP9 on adipogenesis. PMID:26242871

  6. α-Syntrophin Modulates Myogenin Expression in Differentiating Myoblasts

    PubMed Central

    Kim, Min Jeong; Hwang, Sung Ho; Lim, Jeong A.; Froehner, Stanley C.; Adams, Marvin E.; Kim, Hye Sun

    2010-01-01

    Background α-Syntrophin is a scaffolding protein linking signaling proteins to the sarcolemmal dystrophin complex in mature muscle. However, α-syntrophin is also expressed in differentiating myoblasts during the early stages of muscle differentiation. In this study, we examined the relationship between the expression of α-syntrophin and myogenin, a key muscle regulatory factor. Methods and Findings The absence of α-syntrophin leads to reduced and delayed myogenin expression. This conclusion is based on experiments using muscle cells isolated from α-syntrophin null mice, muscle regeneration studies in α-syntrophin null mice, experiments in Sol8 cells (a cell line that expresses only low levels of α-syntrophin) and siRNA studies in differentiating C2 cells. In primary cultured myocytes isolated from α-syntrophin null mice, the level of myogenin was less than 50% that from wild type myocytes (p<0.005) 40 h after differentiation induction. In regenerating muscle, the expression of myogenin in the α-syntrophin null muscle was reduced to approximately 25% that of wild type muscle (p<0.005). Conversely, myogenin expression is enhanced in primary cultures of myoblasts isolated from a transgenic mouse over-expressing α-syntrophin and in Sol8 cells transfected with a vector to over-express α-syntrophin. Moreover, we find that myogenin mRNA is reduced in the absence of α-syntrophin and increased by α-syntrophin over-expression. Immunofluorescence microscopy shows that α-syntrophin is localized to the nuclei of differentiating myoblasts. Finally, immunoprecipitation experiments demonstrate that α-syntrophin associates with Mixed-Lineage Leukemia 5, a regulator of myogenin expression. Conclusions We conclude that α-syntrophin plays an important role in regulating myogenesis by modulating myogenin expression. PMID:21179410

  7. Learning to integrate versus inhibiting information is modulated by age.

    PubMed

    Cappelletti, Marinella; Pikkat, Helen; Upstill, Emily; Speekenbrink, Maarten; Walsh, Vincent

    2015-02-04

    Cognitive training aiming at improving learning is often successful, but what exactly underlies the observed improvements and how these differ across the age spectrum are currently unknown. Here we asked whether learning in young and older people may reflect enhanced ability to integrate information required to perform a cognitive task or whether it may instead reflect the ability to inhibit task-irrelevant information for successful task performance. We trained 30 young and 30 aging human participants on a numerosity discrimination task known to engage the parietal cortex and in which cue-integration and inhibitory abilities can be distinguished. We coupled training with parietal, motor, or sham transcranial random noise stimulation, known for modulating neural activity. Numerosity discrimination improved after training and was maintained long term, especially in the training + parietal stimulation group, regardless of age. Despite the quantitatively similar improvement in the two age groups, the content of learning differed remarkably: aging participants improved more in inhibitory abilities, whereas younger subjects improved in cue-integration abilities. Moreover, differences in the content of learning were reflected in different transfer effects to untrained but related abilities: in the younger group, improvements in cue integration paralleled improvements in continuous quantity (time and space), whereas in the elderly group, improvements in numerosity-based inhibitory abilities generalized to other measures of inhibition and corresponded to a decline in space discrimination, possibly because conflicting learning resources are used in numerosity and continuous quantity processing. These results indicate that training can enhance different, age-dependent cognitive processes and highlight the importance of identifying the exact processes underlying learning for effective training programs.

  8. Polyamine depletion inhibits the autophagic response modulating Trypanosoma cruzi infectivity

    PubMed Central

    Vanrell, María C.; Cueto, Juan A.; Barclay, Jeremías J.; Carrillo, Carolina; Colombo, María I.; Gottlieb, Roberta A.; Romano, Patricia S.

    2013-01-01

    Autophagy is a cell process that in normal conditions serves to recycle cytoplasmic components and aged or damaged organelles. The autophagic pathway has been implicated in many physiological and pathological situations, even during the course of infection by intracellular pathogens. Many compounds are currently used to positively or negatively modulate the autophagic response. Recently it was demonstrated that the polyamine spermidine is a physiological inducer of autophagy in eukaryotic cells. We have previously shown that the etiological agent of Chagas disease, the protozoan parasite Trypanosoma cruzi, interacts with autophagic compartments during host cell invasion and that preactivation of autophagy significantly increases host cell colonization by this parasite. In the present report we have analyzed the effect of polyamine depletion on the autophagic response of the host cell and on T. cruzi infectivity. Our data showed that depleting intracellular polyamines by inhibiting the biosynthetic enzyme ornithine decarboxylase with difluoromethylornithine (DFMO) suppressed the induction of autophagy in response to starvation or rapamycin treatment in two cell lines. This effect was associated with a decrease in the levels of LC3 and ATG5, two proteins required for autophagosome formation. As a consequence of inhibiting host cell autophagy, DFMO impaired T. cruzi colonization, indicating that polyamines and autophagy facilitate parasite infection. Thus, our results point to DFMO as a novel autophagy inhibitor. While other autophagy inhibitors such as wortmannin and 3-methyladenine are nonspecific and potentially toxic, DFMO is an FDA-approved drug that may have value in limiting autophagy and the spread of the infection in Chagas disease and possibly other pathological settings. PMID:23697944

  9. Shh Signaling through the Primary Cilium Modulates Rat Oligodendrocyte Differentiation

    PubMed Central

    Falcón-Urrutia, Paulina; Carrasco, Carlos M.; Lois, Pablo

    2015-01-01

    Primary Cilia (PC) are a very likely place for signal integration where multiple signaling pathways converge. Two major signaling pathways clearly shown to signal through the PC, Sonic Hedgehog (Shh) and PDGF-Rα, are particularly important for the proliferation and differentiation of oligodendrocytes, suggesting that their interaction occurs in or around this organelle. We identified PC in rat oligodendrocyte precursor cells (OPCs) and found that, while easily detectable in early OPCs, PC are lost as these cells progress to terminal differentiation. We confirmed the interaction between these pathways, as cyclopamine inhibition of Hedgehog function impairs both PDGF-mediated OPC proliferation and Shh-dependent cell branching. However, we failed to detect PDGF-Rα localization into the PC. Remarkably, ciliobrevin-mediated disruption of PC and reduction of OPC process extension was counteracted by recombinant Shh treatment, while PDGF had no effect. Therefore, while PDGF-Rα-dependent OPC proliferation and survival most probably does not initiate at the PC, still the integrity of this organelle and cilium-centered pathway is necessary for OPC survival and differentiation. PMID:26218245

  10. Spectral broadening and inhibition of amplitude and frequency modulation in Nd: glass regenerative amplifier

    NASA Astrophysics Data System (ADS)

    Zhang, Yuqi; Pan, Xue; Wang, Jiangfeng; Li, Xuechun

    2014-11-01

    In order to broaden the spectrum of laser pulse and reduce the gain narrowing effect in Nd:glass regenerative amplifier to realize the ambition of inhibiting amplitude and frequency modulation, proper quartz birefringence crystal plate is inserted into the cavity. The influence factors of central wavelength, depth of modulation and range of modulation are obtained theoretically. The width of the spectrum is broadened by controlling all the factors. Two kinds of thickness, 5mm and 6mm, are inserted into the regenerative amplifier cavity. The results of theoretical calculation and experiment both show that the effect of spectrum widening is evident, which reduces the gain narrowing effect to some extent. The amplitude and frequency modulation resulted from gain narrowing effect is inhibited when the central wavelength deflects. The simulated results show that inhibited effect of amplitude and frequency modulation is remarkable. And the method is a potential effective technique for amplitude and frequency modulation inhibition.

  11. RhoA Modulates Smad Signaling during Transforming Growth Factor-β-induced Smooth Muscle Differentiation*

    PubMed Central

    Chen, Shiyou; Crawford, Michelle; Day, Regina M.; Briones, Victorino R.; Leader, Jennifer E.; Jose, Pedro A.; Lechleider, Robert J.

    2007-01-01

    We recently reported that transforming growth factor (TGF)-β induced the neural crest stem cell line Monc-1 to differentiate into a spindle-like contractile smooth muscle cell (SMC) phenotype and that Smad signaling played an important role in this phenomenon. In addition to Smad signaling, other pathways such as mitogen-activated protein kinase (MAPK), phosphoinositol-3 kinase, and RhoA have also been shown to mediate TGF-β actions. The objectives of this study were to examine whether these signaling pathways contribute to TGF-β-induced SMC development and to test whether Smad signaling cross-talks with other pathway(s) during SMC differentiation induced by TGF-β. We demonstrate here that RhoA signaling is critical to TGF-β-induced SMC differentiation. RhoA kinase (ROCK) inhibitor Y27632 significantly blocks the expression of multiple SMC markers such as smooth muscle α-actin, SM22α, and calponin in TGF-β-treated Monc-1 cells. In addition, Y27632 reversed the cell morphology and abolished the contractility of TGF-β-treated cells. RhoA signaling was activated as early as 5 min following TGF-β addition. Dominant negative RhoA blocked nuclear translocation of Smad2 and Smad3 because of the inhibition of phosphorylation of both Smads and inhibited Smad-dependent SBE promoter activity, whereas constitutively active RhoA significantly enhanced SBE promoter activity. Consistent with these results, C3 exotoxin, an inhibitor of RhoA activation, significantly attenuated SBE promoter activity and inhibited Smad nuclear translocation. Taken together, these data point to a new role for RhoA as a modulator of Smad activation while regulating TGF-β-induced SMC differentiation. PMID:16317010

  12. Differential heating in the Indian Ocean differentially modulates precipitation in the Ganges and Brahmaputra Basins

    USGS Publications Warehouse

    Pervez, Shahriar; Henebry, Geoffrey M.

    2016-01-01

    This dataset provides an assessment of the differential heating in the Indian Ocean (IO) and the subsequent modulation of the Ganges and Brahmaputra precipitation. Indo-Pacific sea surface temperature dynamics play a prominent role in Asian summer monsoon variability. Using 28 years of remote sensing observations, we demonstrate that (i) the tropical west-east differential heating in the IO influences the Ganges precipitation and (ii) the north-south differential heating in the IO influences the Brahmaputra precipitation. The El Niño phase induces warming in the warm pool of the IO and exerts more influence on Ganges precipitation than Brahmaputra precipitation. The analyses indicate that both the magnitude and position of the sea surface temperature (SST) anomalies in the IO are important drivers for precipitation dynamics that can be effectively summarized using two new indices, one tuned for each basin. The dataset consists of the spatial structure of the SST anomalies in the IO, the Ganges and the Brahmaputra precipitation dynamics, and the variability in wind, outgoing longwave radiation, and geopotential height anomalies, as well as the new geographic zones to compute west-east and north-south zonal differences in SST anomalies. The purpose of the analyses was to understand the forcing of the precipitation in these river basins associated with changes in acquired energy during different climate modes in the Indo-Pacific.This dataset corresponds to the article referred below. The data were uploaded by the figure numbers from this article. Pervez, M.S., and Henebry, G.M., 2016. Differential heating in the Indian Ocean differentially modulates precipitation in the Ganges and Brahmaputra basins. Remote Sens. 2016, 8(11), 901; doi: 10.3390/rs8110901

  13. The measurement of differential EXAFS modulated by high pressure.

    PubMed

    Chu, Shengqi; Zheng, Lirong; Zhou, Yingli; Zhou, Aiyu; Zhang, Jing; Che, Rongzheng; Liu, Jing; Hu, Tiandou

    2011-09-01

    Differential EXAFS (DiffEXAFS) is able to detect subtle atomic perturbations in the local area of the absorbing atom. Here a new method of performing DiffEXAFS experiments under the modulation of high pressure has been developed. Periodic pressure was achieved in the gasket with the help of a dynamic diamond anvil cell, and the measurements were conducted in common energy-scanning mode. This technique has been utilized on ZnSe at 4.8 GPa. The present results have demonstrated a good agreement with the equation of state of ZnSe, and revealed sensitivity to atomic displacements of one order higher in magnitude than that of conventional EXAFS.

  14. Hedgehog associated to microparticles inhibits adipocyte differentiation via a non-canonical pathway

    PubMed Central

    Fleury, Audrey; Hoch, Lucile; Martinez, M. Carmen; Faure, Hélène; Taddei, Maurizio; Petricci, Elena; Manetti, Fabrizio; Girard, Nicolas; Mann, André; Jacques, Caroline; Larghero, Jérôme; Ruat, Martial; Andriantsitohaina, Ramaroson; Le Lay, Soazig

    2016-01-01

    Hedgehog (Hh) is a critical regulator of adipogenesis. Extracellular vesicles are natural Hh carriers, as illustrated by activated/apoptotic lymphocytes specifically shedding microparticles (MP) bearing the morphogen (MPHh+). We show that MPHh+ inhibit adipocyte differentiation and orientate mesenchymal stem cells towards a pro-osteogenic program. Despite a Smoothened (Smo)-dependency, MPHh+ anti-adipogenic effects do not activate a canonical Hh signalling pathway in contrast to those elicited either by the Smo agonist SAG or recombinant Sonic Hedgehog. The Smo agonist GSA-10 recapitulates many of the hallmarks of MPHh+ anti-adipogenic effects. The adipogenesis blockade induced by MPHh+ and GSA-10 was abolished by the Smo antagonist LDE225. We further elucidate a Smo/Lkb1/Ampk axis as the non-canonical Hh pathway used by MPHh+ and GSA-10 to inhibit adipocyte differentiation. Our results highlight for the first time the ability of Hh-enriched MP to signal via a non-canonical pathway opening new perspectives to modulate fat development. PMID:27010359

  15. Dietary acetylenic oxylipin falcarinol differentially modulates GABAA receptors.

    PubMed

    Czyzewska, Marta Magdalena; Chrobok, Lukasz; Kania, Alan; Jatczak, Magdalena; Pollastro, Federica; Appendino, Giovanni; Mozrzymas, Jerzy Wladyslaw

    2014-12-26

    The dietary oxylipins falcarinol (1a) and falcarindiol (1b) trap thiols by direct nucleophilic addition to their diyne system, but despite this, only falcarinol (1a) is a reversible agonist of cannabinoid receptors, providing a rationale for comparing their activity also on other neuronal targets. Because GABAA receptors (GABAARs) are exquisitely sensitive to polyacetylenic oxylipins in terms of either potentiation (falcarindiol, 1b) or inhibition (oenanthotoxin, 2a), the activity of 1a was investigated on synaptic (α1β2γ2L) and extrasynaptic (α1β2δ and α1β2) subtypes of GABAARs. Falcarinol (1a) significantly enhanced the amplitude of currents mediated by α1β2γ2L receptors, but this effect was associated with a use-dependent block. Conversely, α1β2 receptors were inhibited without any sign of use-dependent block for the entire range of concentrations tested (1-10 μM). Interestingly, responses mediated by α1β2δ receptors, showing no or very little macroscopic desensitization, were strongly potentiated by 1a, exhibiting a fading reminiscent of macroscopic desensitization. When compared to the activity of falcarindiol (1b), falcarinol (1a) showed a higher affinity for GABAARs and, overall, a substantially different profile of pharmacological action. Taken together, the present data support the view that modulation of GABAARs might underlie the insecticidal and sedative activity of falcarinol (1a).

  16. Cigarette Smoke inhibits ROCK2 activation in T cells and modulates IL-22 production

    PubMed Central

    Weng, Chien-Huan; Gupta, Sanjay; Geraghty, Patrick; Foronjy, Robert

    2016-01-01

    Gene-environment interactions are known to play a key role in the development of rheumatoid arthritis (RA). Exposure to cigarette smoke (CS) is one of the strongest environmental risk factors associated with RA and has been shown to mediate a range of complex immunomodulatory effects from decreased T and B cell activation to depressed phagocytic function. The effects of CS on the function of TH17 cells, one of the key TH effector subsets implicated in RA pathogenesis, are not fully understood. IRF4 is one of the crucial transcription factors involved in TH-17 differentiation and is absolutely required for the production of IL-17 and IL-21 but, interestingly, inhibits the synthesis of IL-22. The production of IL-17 and IL-21 by IRF4 can be augmented by its phosphorylation by the serine-threonine kinase ROCK2. Given that CS has been reported to increase ROCK activity in endothelial cells, here we investigated the effects of CS on the ROCK2-IRF4 axis in T cells. Surprisingly, we found that CS leads to decreased ROCK2 activation and IRF4 phosphorylation in T cells. This effect was associated with increased IL-22 production. Using a GEF pull-down assay we furthermore identify ARHGEF1 as a key upstream regulator of ROCK2 whose activity in T cells is inhibited by CS. Thus CS can inhibit the ROCK2-IRF4 axis and modulate T cell production of IL-22. PMID:26882474

  17. Progress Report on Frequency - Modulated Differential Absorption Lidar

    SciTech Connect

    Cannon, Bret D.; Harper, Warren W.; Myers, Tanya L.; Taubman, Matthew S.; Williams, Richard M.; Schultz, John F.

    2001-12-15

    Modeling done at Pacific Northwest National Laboratory (PNNL) in FY2000 predicted improved sensitivity for remote chemical detection by differential absorption lidar (DIAL) if frequency-modulated (FM) lasers were used. This improved sensitivity results from faster averaging away of speckle noise and the recently developed quantum cascade (QC) lasers offer the first practical method for implementing this approach in the molecular fingerprint region of the infrared. To validate this model prediction, a simple laboratory bench FM-DIAL system was designed, assembled, tested, and laboratory-scale experiments were carried out during FY2001. Preliminary results of the FM DIAL experiments confirm the speckle averaging advantages predicted by the models. In addition, experiments were performed to explore the use of hybrid QC - CO2 lasers for achieving sufficient frequency-modulated laser power to enable field experiments at longer ranges (up to one kilometer or so). This approach will allow model validation at realistic ranges much sooner than would be possible if one had to first develop master oscillator - power amplifier systems utilizing only QC devices. Amplification of a QC laser with a CO2 laser was observed in the first hybrid laser experiments, but the low gain and narrow linewidth of the CO2 laser available for these experiments prevented production of a high-power FM laser beam.

  18. Differential Network Analysis Reveals Genetic Effects on Catalepsy Modules

    PubMed Central

    Iancu, Ovidiu D.; Oberbeck, Denesa; Darakjian, Priscila; Kawane, Sunita; Erk, Jason; McWeeney, Shannon; Hitzemann, Robert

    2013-01-01

    We performed short-term bi-directional selective breeding for haloperidol-induced catalepsy, starting from three mouse populations of increasingly complex genetic structure: an F2 intercross, a heterogeneous stock (HS) formed by crossing four inbred strains (HS4) and a heterogeneous stock (HS-CC) formed from the inbred strain founders of the Collaborative Cross (CC). All three selections were successful, with large differences in haloperidol response emerging within three generations. Using a custom differential network analysis procedure, we found that gene coexpression patterns changed significantly; importantly, a number of these changes were concordant across genetic backgrounds. In contrast, absolute gene-expression changes were modest and not concordant across genetic backgrounds, in spite of the large and similar phenotypic differences. By inferring strain contributions from the parental lines, we are able to identify significant differences in allelic content between the selected lines concurrent with large changes in transcript connectivity. Importantly, this observation implies that genetic polymorphisms can affect transcript and module connectivity without large changes in absolute expression levels. We conclude that, in this case, selective breeding acts at the subnetwork level, with the same modules but not the same transcripts affected across the three selections. PMID:23555609

  19. Sox9 modulates cell survival and adipogenic differentiation of multipotent adult rat mesenchymal stem cells.

    PubMed

    Stöckl, Sabine; Bauer, Richard J; Bosserhoff, Anja K; Göttl, Claudia; Grifka, Joachim; Grässel, Susanne

    2013-07-01

    Sox9 is a key transcription factor in early chondrogenesis with distinct roles in differentiation processes and during embryonic development. Here, we report that Sox9 modulates cell survival and contributes to the commitment of mesenchymal stem cells (MSC) to adipogenic or osteogenic differentiation lineages. We found that the Sox9 activity level affects the expression of the key transcription factor in adipogenic differentiation, C/EBPβ, and that cyclin D1 mediates the expression of the osteogenic marker osteocalcin in undifferentiated adult bone-marrow-derived rat MSC. Introducing a stable Sox9 knockdown into undifferentiated rat MSC resulted in a marked decrease in proliferation rate and an increase in apoptotic activity. This was linked to a profound upregulation of p21 and cyclin D1 gene and protein expression accompanied by an induction of caspase 3/7 activity and an inhibition of Bcl-2. We observed that Sox9 silencing provoked a delayed S-phase progression and an increased nuclear localization of p21. The protein stability of cyclin D1 was induced in the absence of Sox9 presumably as a function of altered p38 signalling. In addition, the major transcription factor for adipogenic differentiation, C/EBPβ, was repressed after silencing Sox9. The nearly complete absence of C/EBPβ protein as a result of increased destabilization of the C/EBPβ mRNA and the impact on osteocalcin gene expression and protein synthesis, suggests that a delicate balance of Sox9 level is not only imperative for proper chondrogenic differentiation of progenitor cells, but also affects the adipogenic and probably osteogenic differentiation pathways of MSC. Our results identified Sox9 as an important link between differentiation, proliferation and apoptosis in undifferentiated adult rat mesenchymal stem cells, emphasizing the importance of the delicate balance of a precisely regulated Sox9 activity in MSC not only for proper skeletal development during embryogenesis but probably also

  20. BZ-26, a novel GW9662 derivate, attenuated inflammation by inhibiting the differentiation and activation of inflammatory macrophages.

    PubMed

    Bei, Yuncheng; Chen, Jiajia; Zhou, Feifei; Huang, Yahong; Jiang, Nan; Tan, Renxiang; Shen, Pingping

    2016-12-01

    Peroxisome proliferator-activated receptor-gamma (PPARγ) is considered to be an important transcriptional factor in regulation of macrophages differentiation and activation. We have synthesized a series of novel structural molecules based on GW9662's structure (named BZ-24, BZ-25 and BZ-26), and interaction activity was calculated by computational docking. BZ-26 had shown stronger interaction with PPARγ and had higher transcriptional inhibitory activity of PPARγ with lower dosage compared with GW9662. BZ-26 was proved to inhibit inflammatory macrophage differentiation. LPS-induced acute inflammation mouse model was applied to demonstrate its anti-inflammatory activity. And the results showed that BZ-26 administration attenuated plasma tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) secretion, which are vital cytokines in acute inflammation. The anti-inflammatory activity was examined in THP-1 cell line, and TNF-α, IL-6 and MCP-1, were significantly inhibited. The results of Western blot and luciferase reporter assay indicated that BZ-26 not only inhibited NF-κB transcriptional activity, but also abolished LPS-induce nuclear translocation of P65. We also test BZ-26 action in tumor-bearing chronic inflammation mouse model, and BZ-26 was able to alter macrophages phenotype, resulting in antitumor effect. All our data revealed that BZ-26 modulated LPS-induced acute inflammation via inhibiting inflammatory macrophages differentiation and activation, potentially via inhibition of NF-κB signal pathway.

  1. Monocyte cell surface glycosaminoglycans positively modulate IL-4-induced differentiation toward dendritic cells.

    PubMed

    den Dekker, Els; Grefte, Sander; Huijs, Tonnie; ten Dam, Gerdy B; Versteeg, Elly M M; van den Berk, Lieke C J; Bladergroen, Bellinda A; van Kuppevelt, Toin H; Figdor, Carl G; Torensma, Ruurd

    2008-03-15

    IL-4 induces the differentiation of monocytes toward dendritic cells (DCs). The activity of many cytokines is modulated by glycosaminoglycans (GAGs). In this study, we explored the effect of GAGs on the IL-4-induced differentiation of monocytes toward DCs. IL-4 dose-dependently up-regulated the expression of DC-specific ICAM-3-grabbing nonintegrin (DC-SIGN), CD80, CD206, and CD1a. Monocytes stained positive with Abs against heparan sulfate (HS) and chondroitin sulfate (CS) B (CSB; dermatan sulfate), but not with Abs that recognize CSA, CSC, and CSE. Inhibition of sulfation of monocyte/DC cell surface GAGs by sodium chlorate reduced the reactivity of sulfate-recognizing single-chain Abs. This correlated with hampered IL-4-induced DC differentiation as evidenced by lower expression of DC-SIGN and CD1a and a decreased DC-induced PBL proliferation, suggesting that sulfated monocyte cell surface GAGs support IL-4 activity. Furthermore, removal of cell surface chondroitin sulfates by chondroitinase ABC strongly impaired IL-4-induced STAT6 phosphorylation, whereas removal of HS by heparinase III had only a weak inhibitory effect. IL-4 bound to heparin and CSB, but not to HS, CSA, CSC, CSD, and CSE. Binding of IL-4 required iduronic acid, an N-sulfate group (heparin) and specific O sulfates (CSB and heparin). Together, these data demonstrate that monocyte cell surface chondroitin sulfates play an important role in the IL-4-driven differentiation of monocytes into DCs.

  2. Placental Kisspeptins Differentially Modulate Vital Parameters of Estrogen Receptor-Positive and -Negative Breast Cancer Cells.

    PubMed

    Rasoulzadeh, Zahra; Ghods, Roya; Kazemi, Tohid; Mirzadegan, Ebrahim; Ghaffari-Tabrizi-Wizsy, Nassim; Rezania, Simin; Kazemnejad, Somaieh; Arefi, Soheila; Ghasemi, Jamileh; Vafaei, Sedigheh; Mahmoudi, Ahmad-Reza; Zarnani, Amir-Hassan

    2016-01-01

    Kisspeptins (KPs) are major regulators of trophoblast and cancer invasion. Thus far, limited and conflicting data are available on KP-mediated modulation of breast cancer (BC) metastasis; mostly based on synthetic KP-10, the most active fragment of KP. Here, we report for the first time comprehensive functional effects of term placental KPs on proliferation, adhesion, Matrigel invasion, motility, MMP activity and pro-inflammatory cytokine production in MDA-MB-231 (estrogen receptor-negative) and MCF-7 (estrogen receptor-positive). KPs were expressed at high level by term placental syncytiotrophoblasts and released in soluble form. Placental explant conditioned medium containing KPs (CM) significantly reduced proliferation of both cell types compared to CM without (w/o) KP (CM-w/o KP) in a dose- and time-dependent manner. In MDA-MB-231 cells, placental KPs significantly reduced adhesive properties, while increased MMP9 and MMP2 activity and stimulated invasion. Increased invasiveness of MDA-MB-231 cells after CM treatment was inhibited by KP receptor antagonist, P-234. CM significantly reduced motility of MCF-7 cells at all time points (2-30 hr), while it stimulated motility of MDA-MB-231 cells. These effects were reversed by P-234. Co-treatment with selective ER modulators, Tamoxifen and Raloxifene, inhibited the effect of CM on motility of MCF-7 cells. The level of IL-6 in supernatant of MCF-7 cells treated with CM was higher compared to those treated with CM-w/o KP. Both cell types produced more IL-8 after treatment with CM compared to those treated with CM-w/o KP. Taken together, our observations suggest that placental KPs differentially modulate vital parameters of estrogen receptor-positive and -negative BC cells possibly through modulation of pro-inflammatory cytokine production.

  3. Placental Kisspeptins Differentially Modulate Vital Parameters of Estrogen Receptor-Positive and -Negative Breast Cancer Cells

    PubMed Central

    Rasoulzadeh, Zahra; Ghods, Roya; Kazemi, Tohid; Mirzadegan, Ebrahim; Ghaffari-Tabrizi-Wizsy, Nassim; Rezania, Simin; Kazemnejad, Somaieh; Arefi, Soheila; Ghasemi, Jamileh; Vafaei, Sedigheh; Mahmoudi, Ahmad-Reza; Zarnani, Amir-Hassan

    2016-01-01

    Kisspeptins (KPs) are major regulators of trophoblast and cancer invasion. Thus far, limited and conflicting data are available on KP-mediated modulation of breast cancer (BC) metastasis; mostly based on synthetic KP-10, the most active fragment of KP. Here, we report for the first time comprehensive functional effects of term placental KPs on proliferation, adhesion, Matrigel invasion, motility, MMP activity and pro-inflammatory cytokine production in MDA-MB-231 (estrogen receptor-negative) and MCF-7 (estrogen receptor-positive). KPs were expressed at high level by term placental syncytiotrophoblasts and released in soluble form. Placental explant conditioned medium containing KPs (CM) significantly reduced proliferation of both cell types compared to CM without (w/o) KP (CM-w/o KP) in a dose- and time-dependent manner. In MDA-MB-231 cells, placental KPs significantly reduced adhesive properties, while increased MMP9 and MMP2 activity and stimulated invasion. Increased invasiveness of MDA-MB-231 cells after CM treatment was inhibited by KP receptor antagonist, P-234. CM significantly reduced motility of MCF-7 cells at all time points (2–30 hr), while it stimulated motility of MDA-MB-231 cells. These effects were reversed by P-234. Co-treatment with selective ER modulators, Tamoxifen and Raloxifene, inhibited the effect of CM on motility of MCF-7 cells. The level of IL-6 in supernatant of MCF-7 cells treated with CM was higher compared to those treated with CM-w/o KP. Both cell types produced more IL-8 after treatment with CM compared to those treated with CM-w/o KP. Taken together, our observations suggest that placental KPs differentially modulate vital parameters of estrogen receptor-positive and -negative BC cells possibly through modulation of pro-inflammatory cytokine production. PMID:27101408

  4. Inhibition of Rho-kinase differentially affects axon regeneration of peripheral motor and sensory nerves.

    PubMed

    Joshi, Abhijeet R; Bobylev, Ilja; Zhang, Gang; Sheikh, Kazim A; Lehmann, Helmar C

    2015-01-01

    The small GTPase RhoA and its down-stream effector Rho-kinase (ROCK) are important effector molecules of the neuronal cytoskeleton. Modulation of the RhoA/ROCK pathway has been shown to promote axonal regeneration, however in vitro and animal studies are inconsistent regarding the extent of axonal outgrowth induced by pharmacological inhibition of ROCK. We hypothesized that injury to sensory and motor nerves result in diverse activation levels of RhoA, which may impact the response of those nerve fiber modalities to ROCK inhibition. We therefore examined the effects of Y-27632, a chemical ROCK inhibitor, on the axonal outgrowth of peripheral sensory and motor neurons grown in the presence of growth-inhibiting chondroitin sulfate proteoglycans (CSPGs). In addition we examined the effects of three different doses of Y-27632 on nerve regeneration of motor and sensory nerves in animal models of peripheral nerve crush. In vitro, sensory neurons were less responsive to Y-27632 compared to motor neurons in a non-growth permissive environment. These differences were associated with altered expression and activation of RhoA in sensory and motor axons. In vivo, systemic treatment with high doses of Y-27632 significantly enhanced the regeneration of motor axons over short distances, while the regeneration of sensory fibers remained largely unchanged. Our results support the concept that in a growth non-permissive environment, the regenerative capacity of sensory and motor axons is differentially affected by the RhoA/ROCK pathway, with motor neurons being more responsive compared to sensory. Future treatments, that are aimed to modulate RhoA activity, should consider this functional diversity.

  5. Tonic and phasic differential GABAergic inhibition of synaptic actions of joint afferents in the cat.

    PubMed

    Rudomin, P; Hernández, E; Lomelí, J

    2007-01-01

    The aim of this study was to examine the functional organization of the spinal neuronal networks activated by myelinated afferent fibers in the posterior articular nerve (PAN) of the anesthetized cat. Particular attention was given to the tonic and phasic GABAa inhibitory modulation of these networks. Changes in the synaptic effectiveness of the joint afferents were inferred from changes in the intraspinal focal potentials produced by electrical stimulation of the PAN. We found that conditioning stimulation of cutaneous nerves (sural, superficial peroneus and saphenous) and of the nucleus raphe magnus often inhibited, in a differential manner, the early and late components of the intraspinal focal potentials produced by stimulation of low and high threshold myelinated PAN afferents, respectively. The degree of the inhibition depended on the strength of both the conditioning and test stimuli and on the segmental level of recording. Conditioning stimulation of group I muscle afferents was less effective, but marked depression of the early and late focal potentials was produced by stimuli exceeding 5 xT. The i.v. injection of 1-2.5 mg/kg of picrotoxin, a GABAa blocker, had relatively minor effects on the early components of the PAN focal potentials, but was able to induce a significant increase of the late components. It also reduced the inhibitory effects of cutaneous and joint nerve conditioning on PAN focal responses. Conditioning autogenetic stimulation with high-frequency trains depressed the PAN focal potentials. The late components of the PAN responses remained depressed several minutes after discontinuing the conditioning train, even after picrotoxin administration. The present observations indicate that the neuronal networks activated by the low threshold PAN afferents show a relatively small post-activation depression and appear to be subjected to a minor tonic inhibitory GABAa control. In contrast, the pathways activated by stimulation of high threshold

  6. Encephalitozoon intestinalis Inhibits Dendritic Cell Differentiation through an IL-6-Dependent Mechanism

    PubMed Central

    Bernal, Carmen E.; Zorro, Maria M.; Sierra, Jelver; Gilchrist, Katherine; Botero, Jorge H.; Baena, Andres; Ramirez-Pineda, Jose R.

    2016-01-01

    Microsporidia are a group of intracellular pathogens causing self-limited and severe diseases in immunocompetent and immunocompromised individuals, respectively. A cellular type 1 adaptive response, mediated by IL-12, IFNγ, CD4+, and CD8+ T cells has been shown to be essential for host resistance, and dendritic cells (DC) play a key role at eliciting anti-microsporidial immunity. We investigated the in vitro response of DC and DC precursors/progenitors to infection with Encephalitozoon intestinalis (Ei), a common agent of human microsporidosis. Ei-exposed DC cultures up-regulated the surface expression of MHC class II and the costimulatory molecules CD86 and CD40, only when high loads of spores were used. A vigorous secretion of IL-6 but not of IL-1β or IL-12p70 was also observed in these cultures. Ei-exposed DC cultures consisted of immature infected and mature bystander DC, as assessed by MHC class II and costimulatory molecules expression, suggesting that intracellular Ei spores deliver inhibitory signals in DC. Moreover, Ei selectively inhibited the secretion of IL-12p70 in LPS-stimulated DC. Whereas Ei-exposed DC promoted allogeneic naïve T cell proliferation and IL-2 and IFNγ secretion in DC-CD4+ T cell co-cultures, separated co-cultures with bystander or infected DCs showed stimulation or inhibition of IFNγ secretion, respectively. When DC precursors/progenitors were exposed to Ei spores, a significant inhibition of DC differentiation was observed without shifting the development toward cells phenotypically or functionally compatible with myeloid-derived suppressor cells. Neutralization experiments demonstrated that this inhibitory effect is IL-6-dependent. Altogether this investigation reveals a novel potential mechanism of immune escape of microsporidian parasites through the modulation of DC differentiation and maturation. PMID:26870700

  7. Encephalitozoon intestinalis Inhibits Dendritic Cell Differentiation through an IL-6-Dependent Mechanism.

    PubMed

    Bernal, Carmen E; Zorro, Maria M; Sierra, Jelver; Gilchrist, Katherine; Botero, Jorge H; Baena, Andres; Ramirez-Pineda, Jose R

    2016-01-01

    Microsporidia are a group of intracellular pathogens causing self-limited and severe diseases in immunocompetent and immunocompromised individuals, respectively. A cellular type 1 adaptive response, mediated by IL-12, IFNγ, CD4+, and CD8+ T cells has been shown to be essential for host resistance, and dendritic cells (DC) play a key role at eliciting anti-microsporidial immunity. We investigated the in vitro response of DC and DC precursors/progenitors to infection with Encephalitozoon intestinalis (Ei), a common agent of human microsporidosis. Ei-exposed DC cultures up-regulated the surface expression of MHC class II and the costimulatory molecules CD86 and CD40, only when high loads of spores were used. A vigorous secretion of IL-6 but not of IL-1β or IL-12p70 was also observed in these cultures. Ei-exposed DC cultures consisted of immature infected and mature bystander DC, as assessed by MHC class II and costimulatory molecules expression, suggesting that intracellular Ei spores deliver inhibitory signals in DC. Moreover, Ei selectively inhibited the secretion of IL-12p70 in LPS-stimulated DC. Whereas Ei-exposed DC promoted allogeneic naïve T cell proliferation and IL-2 and IFNγ secretion in DC-CD4+ T cell co-cultures, separated co-cultures with bystander or infected DCs showed stimulation or inhibition of IFNγ secretion, respectively. When DC precursors/progenitors were exposed to Ei spores, a significant inhibition of DC differentiation was observed without shifting the development toward cells phenotypically or functionally compatible with myeloid-derived suppressor cells. Neutralization experiments demonstrated that this inhibitory effect is IL-6-dependent. Altogether this investigation reveals a novel potential mechanism of immune escape of microsporidian parasites through the modulation of DC differentiation and maturation.

  8. Metabotropic glutamate receptors differentially regulate GABAergic inhibition in thalamus.

    PubMed

    Govindaiah, G; Cox, Charles L

    2006-12-27

    Thalamic interneurons and thalamic reticular nucleus (TRN) neurons provide inhibitory innervation of thalamocortical cells that significantly influence thalamic gating. The local interneurons in the dorsal lateral geniculate nucleus (dLGN) give rise to two distinct synaptic outputs: classical axonal and dendrodendritic. Activation of metabotropic glutamate receptors (mGluRs) by agonists or optic tract stimulation increases the output of these presynaptic dendrites leading to increased inhibition of thalamocortical neurons. The present study was aimed to evaluate the actions of specific mGluRs on inhibitory GABA-mediated signaling. We found that the group I mGluR (mGluR(1,5)) agonist (RS)-3,5-dihydroxyphenylglycine (DHPG) or optic tract stimulation produced a robust increase in spontaneous IPSCs (sIPSCs) in thalamocortical neurons that was attenuated by the selective mGluR(5) antagonist 2-methyl-6-(phenylethynyl)pyridine hydrochloride (MPEP). In contrast, the group II mGluR (mGluR(2,3)) agonists (2R, 4R)-4-aminopyrrolidine-2,4-dicarboxylate (APDC) or (2S,2'R,3'R)-2-(2'3'-dicarboxycyclopropyl)glycine (DCG-IV) suppressed the frequency of sIPSCs. In addition, mGluR(1,5) agonist DHPG produced depolarizations and mGluR(2/3) agonists APDC or L-CCG-I [(2S,1'S,2'S)-2-(carboxycyclopropyl)glycine] produced hyperpolarizations in dLGN interneurons. Furthermore, the enhanced sIPSC activity by optic tract stimulation was reduced when paired with corticothalamic fiber stimulation. The present data indicate that activation of specific mGluR subtypes differentially regulates inhibitory activity via different synaptic pathways. Our results suggest that activation of specific mGluR subtypes can upregulate or downregulate inhibitory activity in thalamic relay neurons, and these actions likely shape excitatory synaptic integration and thus regulate information transfer through thalamocortical circuits.

  9. Inhibition of light tunneling for multichannel excitations in longitudinally modulated waveguide arrays

    SciTech Connect

    Lobanov, Valery E.; Vysloukh, Victor A.; Kartashov, Yaroslav V.

    2010-02-15

    We consider the evolution of multichannel excitations in longitudinally modulated waveguide arrays where the refractive index either oscillates out-of-phase in all neighboring waveguides or when it is modulated in phase in several central waveguides surrounded by out-of-phase oscillating neighbors. Both types of modulations allow resonant inhibition of light tunneling, but only the modulation of the latter type conserves the internal structure of multichannel excitations. We show that parameter regions where light tunneling inhibition is possible depend on the symmetry and structure of multichannel excitations. Antisymmetric multichannel excitations are more robust than their symmetric counterparts and experience nonlinearity-induced delocalization at higher amplitudes.

  10. The proteasome controls presynaptic differentiation through modulation of an on-site pool of polyubiquitinated conjugates

    PubMed Central

    Pinto, Maria J.; Alves, Pedro L.; Martins, Luís; Pedro, Joana R.; Ryu, Hyun R.; Jeon, Noo Li; Taylor, Anne M.

    2016-01-01

    Differentiation of the presynaptic terminal is a complex and rapid event that normally occurs in spatially specific axonal regions distant from the soma; thus, it is believed to be dependent on intra-axonal mechanisms. However, the full nature of the local events governing presynaptic assembly remains unknown. Herein, we investigated the involvement of the ubiquitin–proteasome system (UPS), the major degradative pathway, in the local modulation of presynaptic differentiation. We found that proteasome inhibition has a synaptogenic effect on isolated axons. In addition, formation of a stable cluster of synaptic vesicles onto a postsynaptic partner occurs in parallel to an on-site decrease in proteasome degradation. Accumulation of ubiquitinated proteins at nascent sites is a local trigger for presynaptic clustering. Finally, proteasome-related ubiquitin chains (K11 and K48) function as signals for the assembly of presynaptic terminals. Collectively, we propose a new axon-intrinsic mechanism for presynaptic assembly through local UPS inhibition. Subsequent on-site accumulation of proteins in their polyubiquitinated state triggers formation of presynapses. PMID:27022091

  11. Modulation of Dendritic Cell Immunobiology via Inhibition of 3-Hydroxy-3-Methylglutaryl-CoA (HMG-CoA) Reductase

    PubMed Central

    Luessi, Felix; Bendix, Ivo; Paterka, Magdalena; Prozorovski, Timour; Treue, Denise; Luenstedt, Sarah; Herz, Josephine; Siffrin, Volker; Infante-Duarte, Carmen; Zipp, Frauke; Waiczies, Sonia

    2014-01-01

    The maturation status of dendritic cells determines whether interacting T cells are activated or if they become tolerant. Previously we could induce T cell tolerance by applying a 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor (HMGCRI) atorvastatin, which also modulates MHC class II expression and has therapeutic potential in autoimmune disease. Here, we aimed at elucidating the impact of this therapeutic strategy on T cell differentiation as a consequence of alterations in dendritic cell function. We investigated the effect of HMGCRI during differentiation of peripheral human monocytes and murine bone marrow precursors to immature DC in vitro and assessed their phenotype. To examine the stimulatory and tolerogenic capacity of these modulated immature dendritic cells, we measured proliferation and suppressive function of CD4+ T cells after stimulation with the modulated immature dendritic cells. We found that an HMGCRI, atorvastatin, prevents dendrite formation during the generation of immature dendritic cells. The modulated immature dendritic cells had a diminished capacity to take up and present antigen as well as to induce an immune response. Of note, the consequence was an increased capacity to differentiate naïve T cells towards a suppressor phenotype that is less sensitive to proinflammatory stimuli and can effectively inhibit the proliferation of T effector cells in vitro. Thus, manipulation of antigen-presenting cells by HMGCRI contributes to an attenuated immune response as shown by promotion of T cells with suppressive capacities. PMID:25013913

  12. Bestatin inhibits cell growth, cell division, and spore cell differentiation in Dictyostelium discoideum.

    PubMed

    Poloz, Yekaterina; Catalano, Andrew; O'Day, Danton H

    2012-04-01

    Bestatin methyl ester (BME) is an inhibitor of Zn(2+)-binding aminopeptidases that inhibits cell proliferation and induces apoptosis in normal and cancer cells. We have used Dictyostelium as a model organism to study the effects of BME. Only two Zn(2+)-binding aminopeptidases have been identified in Dictyostelium to date, puromycin-sensitive aminopeptidase A and B (PsaA and PsaB). PSA from other organisms is known to regulate cell division and differentiation. Here we show that PsaA is differentially expressed throughout growth and development of Dictyostelium, and its expression is regulated by developmental morphogens. We present evidence that BME specifically interacts with PsaA and inhibits its aminopeptidase activity. Treatment of cells with BME inhibited the rate of cell growth and the frequency of cell division in growing cells and inhibited spore cell differentiation during late development. Overexpression of PsaA-GFP (where GFP is green fluorescent protein) also inhibited spore cell differentiation but did not affect growth. Using chimeras, we have identified that nuclear versus cytoplasmic localization of PsaA affects the choice between stalk or spore cell differentiation pathway. Cells that overexpressed PsaA-GFP (primarily nuclear) differentiated into stalk cells, while cells that overexpressed PsaAΔNLS2-GFP (cytoplasmic) differentiated into spores. In conclusion, we have identified that BME inhibits cell growth, division, and differentiation in Dictyostelium likely through inhibition of PsaA.

  13. QSAR Differential Model for Prediction of SIRT1 Modulation using Monte Carlo Method.

    PubMed

    Kumar, Ashwani; Chauhan, Shilpi

    2017-03-01

    Silent information regulator 2 homologue one (SIRT1) modulators have therapeutic potential for a number of diseases like cardiovascular, metabolic, inflammatory and age related disorders. Here, we have studied both activators and inhibitors of SIRT1 and constructed differential quantitative structure activity relationship (QSAR) models using CORAL software by Monte Carlo optimization method and SMILES notation. 3 splits divided into 3 subsets: sub-training, calibration and test sets, were examined and validated with a prediction set. All the described models were statistically significant models. The values of sensitivity, specificity, accuracy and Matthews' correlation coefficient for the validation set of best model were 1.0000, 0.8889, 0.9524 and 0.9058, respectively. In mechanistic interpretation, structural features important for SIRT1 activation and inhibition have been defined.

  14. Unsupervised learning approach to adaptive differential pulse code modulation.

    PubMed

    Griswold, N C; Sayood, K

    1982-04-01

    This research is concerned with investigating the problem of data compression utilizing an unsupervised estimation algorithm. This extends previous work utilizing a hybrid source coder which combines an orthogonal transformation with differential pulse code modulation (DPCM). The data compression is achieved in the DPCM loop, and it is the quantizer of this scheme which is approached from an unsupervised learning procedure. The distribution defining the quantizer is represented as a set of separable Laplacian mixture densities for two-dimensional images. The condition of identifiability is shown for the Laplacian case and a decision directed estimate of both the active distribution parameters and the mixing parameters are discussed in view of a Bayesian structure. The decision directed estimators, although not optimum, provide a realizable structure for estimating the parameters which define a distribution which has become active. These parameters are then used to scale the optimum (in the mean square error sense) Laplacian quantizer. The decision criteria is modified to prevent convergence to a single distribution which in effect is the default condition for a variance estimator. This investigation was applied to a test image and the resulting data demonstrate improvement over other techniques using fixed bit assignments and ideal channel conditions.

  15. Eltrombopag inhibits the proliferation of leukemia cells via reduction of intracellular iron and induction of differentiation.

    PubMed

    Roth, Michael; Will, Britta; Simkin, Guillermo; Narayanagari, Swathi; Barreyro, Laura; Bartholdy, Boris; Tamari, Roni; Mitsiades, Constantine S; Verma, Amit; Steidl, Ulrich

    2012-07-12

    Eltrombopag (EP) is a small-molecule, nonpeptide thrombopoietin receptor (TPO-R) agonist that has been approved recently for the treatment of thrombocytopenia in patients with chronic immune thrombocytopenic purpura. Prior studies have shown that EP stimulates megakaryopoiesis in BM cells from patients with acute myeloid leukemia and myelodysplastic syndrome, and the results also suggested that it may inhibit leukemia cell growth. In the present study, we studied the effects of EP on leukemia cell proliferation and the mechanism of its antiproliferative effects. We found that EP leads to a decreased cell division rate, a block in G(1) phase of cell cycle, and increased differentiation in human and murine leukemia cells. Because EP is species specific in that it can only bind TPO-R in human and primate cells, these findings further suggested that the antileukemic effect is independent of TPO-R. We found that treatment with EP leads to a reduction in free intracellular iron in leukemic cells in a dose-dependent manner. Experimental increase of intracellular iron abrogated the antiproliferative and differentiation-inducing effects of EP, demonstrating that its antileukemic effects are mediated through modulation of intracellular iron content. Finally, determination of EP's antileukemic activity in vivo demonstrated its ability to prolong survival in 2 mouse models of leukemia.

  16. Adiponectin modulates excitability of rat paraventricular nucleus neurons by differential modulation of potassium currents.

    PubMed

    Hoyda, Ted D; Ferguson, Alastair V

    2010-07-01

    The adipocyte-derived hormone adiponectin acts at two seven-transmembrane domain receptors, adiponectin receptor 1 and adiponectin receptor 2, present in the paraventricular nucleus of the hypothalamus to regulate neuronal excitability and endocrine function. Adiponectin depolarizes rat parvocellular preautonomic neurons that secrete either thyrotropin releasing hormone or oxytocin and parvocellular neuroendocrine corticotropin releasing hormone neurons, leading to an increase in plasma adrenocorticotropin hormone concentrations while also hyperpolarizing a subgroup of neurons. In the present study, we investigate the ionic mechanisms responsible for these changes in excitability in parvocellular paraventricular nucleus neurons. Patch clamp recordings of currents elicited from slow voltage ramps and voltage steps indicate that adiponectin inhibits noninactivating delayed rectifier potassium current (I(K)) in a majority of neurons. This inhibition produced a broadening of the action potential in cells that depolarized in the presence of adiponectin. The depolarizing effects of adiponectin were abolished in cells pretreated with tetraethyl ammonium (0/15 cells depolarize). Slow voltage ramps performed during adiponectin-induced hyperpolarization indicate the activation of voltage-independent potassium current. These hyperpolarizing responses were abolished in the presence of glibenclamide [an ATP-sensitive potassium (K(ATP)) channel blocker] (0/12 cells hyperpolarize). The results presented in this study suggest that adiponectin controls neuronal excitability through the modulation of different potassium conductances, effects which contribute to changes in excitability and action potential profiles responsible for peptidergic release into the circulation.

  17. Differential heating in the Indian Ocean differentially modulates precipitation in the Ganges and Brahmaputra basins

    USGS Publications Warehouse

    Pervez, Md Shahriar; Henebry, Geoffrey M.

    2016-01-01

    Indo-Pacific sea surface temperature dynamics play a prominent role in Asian summer monsoon variability. Two interactive climate modes of the Indo-Pacific—the El Niño/Southern Oscillation (ENSO) and the Indian Ocean dipole mode—modulate the amount of precipitation over India, in addition to precipitation over Africa, Indonesia, and Australia. However, this modulation is not spatially uniform. The precipitation in southern India is strongly forced by the Indian Ocean dipole mode and ENSO. In contrast, across northern India, encompassing the Ganges and Brahmaputra basins, the climate mode influence on precipitation is much less. Understanding the forcing of precipitation in these river basins is vital for food security and ecosystem services for over half a billion people. Using 28 years of remote sensing observations, we demonstrate that (i) the tropical west-east differential heating in the Indian Ocean influences the Ganges precipitation and (ii) the north-south differential heating in the Indian Ocean influences the Brahmaputra precipitation. The El Niño phase induces warming in the warm pool of the Indian Ocean and exerts more influence on Ganges precipitation than Brahmaputra precipitation. The analyses indicate that both the magnitude and position of the sea surface temperature anomalies in the Indian Ocean are important drivers for precipitation dynamics that can be effectively summarized using two new indices, one tuned for each basin. These new indices have the potential to aid forecasting of drought and flooding, to contextualize land cover and land use change, and to assess the regional impacts of climate change.

  18. Parabens inhibit fatty acid amide hydrolase: A potential role in paraben-enhanced 3T3-L1 adipocyte differentiation.

    PubMed

    Kodani, Sean D; Overby, Haley B; Morisseau, Christophe; Chen, Jiangang; Zhao, Ling; Hammock, Bruce D

    2016-11-16

    Parabens are a class of small molecules that are regularly used as preservatives in a variety of personal care products. Several parabens, including butylparaben and benzylparaben, have been found to interfere with endocrine signaling and to stimulate adipocyte differentiation. We hypothesized these biological effects could be due to interference with the endocannabinoid system and identified fatty acid amide hydrolase (FAAH) as the direct molecular target of parabens. FAAH inhibition by parabens yields mixed-type and time-independent kinetics. Additionally, structure activity relationships indicate FAAH inhibition is selective for the paraben class of compounds and the more hydrophobic parabens have higher potency. Parabens enhanced 3T3-L1 adipocyte differentiation in a dose dependent fashion, different from two other FAAH inhibitors URB597 and PF622. Moreover, parabens, URB597 and PF622 all failed to enhance AEA-induced differentiation. Furthermore, rimonabant, a cannabinoid receptor 1 (CB1)-selective antagonist, did not attenuate paraben-induced adipocyte differentiation. Thus, adipogenesis mediated by parabens likely occurs through modulation of endocannabinoids, but cell differentiation is independent of direct activation of CB1 by endocannabinoids.

  19. N2 and P3 modulation during partial inhibition in a modified go/nogo task.

    PubMed

    Nguyen, An T; Moyle, Jonson J; Fox, Allison M

    2016-09-01

    The neural response following the partial inhibition of responses can provide insight into the processes underlying response inhibition. We examined the N2 and P3 on trials where participants correctly responded to go stimuli, successfully inhibited their response to nogo stimuli, and nogo trials where they initiated but did not complete their response (partial inhibitions) in an adult sample (N=24, M(age)=21.17, SD(age)=3.52). An enhanced and delayed N2 was observed on partially inhibited compared to successfully inhibited nogo trials. Further analysis showed that this modulation was error-related. An enhanced central P3 was observed following successful inhibitions compared to correct go trials, but not following partial inhibitions. The results suggest that the central P3 enhancement is specific to the complete and successful inhibition of responses. Therefore, the absence of a central P3 on partial inhibitions could reflect insufficient inhibition or a monitored failure in inhibiting the response. Although, our findings provide support for the role of P3 in response inhibition, it raises questions about the processes involved in the subsequent inhibition or correction of the erroneous response. Further research examining the neural response following both partial and unsuccessful inhibitions could provide insight regarding these processes.

  20. Differential Inhibition of Type I Interferon Induction by Arenavirus Nucleoproteins▿

    PubMed Central

    Martínez-Sobrido, Luis; Giannakas, Panagiotis; Cubitt, Beatrice; García-Sastre, Adolfo; de la Torre, Juan Carlos

    2007-01-01

    We have documented that the nucleoprotein (NP) of the prototypic arenavirus lymphocytic choriomeningitis virus is an antagonist of the type I interferon response. In this study we tested the ability of NPs encoded by representative arenavirus species from both Old World and New World antigenic groups to inhibit production of interferon. We found that, with the exception of Tacaribe virus (TCRV), all NPs tested inhibited activation of beta interferon and interferon regulatory factor 3 (IRF-3)-dependent promoters, as well as the nuclear translocation of IRF-3. Consistent with this observation, TCRV-infected cells also failed to inhibit interferon production. PMID:17804508

  1. GPU-based parallel clustered differential pulse code modulation

    NASA Astrophysics Data System (ADS)

    Wu, Jiaji; Li, Wenze; Kong, Wanqiu

    2015-10-01

    Hyperspectral remote sensing technology is widely used in marine remote sensing, geological exploration, atmospheric and environmental remote sensing. Owing to the rapid development of hyperspectral remote sensing technology, resolution of hyperspectral image has got a huge boost. Thus data size of hyperspectral image is becoming larger. In order to reduce their saving and transmission cost, lossless compression for hyperspectral image has become an important research topic. In recent years, large numbers of algorithms have been proposed to reduce the redundancy between different spectra. Among of them, the most classical and expansible algorithm is the Clustered Differential Pulse Code Modulation (CDPCM) algorithm. This algorithm contains three parts: first clusters all spectral lines, then trains linear predictors for each band. Secondly, use these predictors to predict pixels, and get the residual image by subtraction between original image and predicted image. Finally, encode the residual image. However, the process of calculating predictors is timecosting. In order to improve the processing speed, we propose a parallel C-DPCM based on CUDA (Compute Unified Device Architecture) with GPU. Recently, general-purpose computing based on GPUs has been greatly developed. The capacity of GPU improves rapidly by increasing the number of processing units and storage control units. CUDA is a parallel computing platform and programming model created by NVIDIA. It gives developers direct access to the virtual instruction set and memory of the parallel computational elements in GPUs. Our core idea is to achieve the calculation of predictors in parallel. By respectively adopting global memory, shared memory and register memory, we finally get a decent speedup.

  2. Contact sensitizers modulate the arachidonic acid metabolism of PMA-differentiated U-937 monocytic cells activated by LPS

    SciTech Connect

    Del Bufalo, Aurelia; Bernad, Jose; Dardenne, Christophe; Verda, Denis; Meunier, Jean Roch; Rousset, Francoise; Martinozzi-Teissier, Silvia; Pipy, Bernard

    2011-10-01

    For the effective induction of a hapten-specific T cell immune response toward contact sensitizers, in addition to covalent-modification of skin proteins, the redox and inflammatory statuses of activated dendritic cells are crucial. The aim of this study was to better understand how sensitizers modulate an inflammatory response through cytokines production and COX metabolism cascade. To address this purpose, we used the human monocytic-like U-937 cell line differentiated by phorbol myristate acetate (PMA) and investigated the effect of 6 contact sensitizers (DNCB, PPD, hydroquinone, propyl gallate, cinnamaldehyde and eugenol) and 3 non sensitizers (lactic acid, glycerol and tween 20) on the production of pro-inflammatory cytokines (IL-1{beta} and TNF-{alpha}) and on the arachidonic acid metabolic profile after bacterial lipopolysaccharide (LPS) stimulation. Our results showed that among the tested molecules, all sensitizers specifically prevent the production of PMA/LPS-induced COX-2 metabolites (PGE{sub 2,} TxB{sub 2} and PGD{sub 2}), eugenol and cinnamaldehyde inhibiting also the production of IL-1{beta} and TNF-{alpha}. We further demonstrated that there is no unique PGE{sub 2} inhibition mechanism: while the release of arachidonic acid (AA) from membrane phospholipids does not appear do be a target of modulation, COX-2 expression and/or COX-2 enzymatic activity are the major steps of prostaglandin synthesis that are inhibited by sensitizers. Altogether these results add a new insight into the multiple biochemical effects described for sensitizers. - Highlights: > We investigated how contact sensitizers modulate an inflammatory response. > We used macrophage-differentiated cell line, U-937 treated with PMA/LPS. > Sensitizers specifically inhibit the production of COX metabolites (PGE2, TxB2). > Several mechanisms of inhibition: COX-2 expression/enzymatic activity, isomerases. > New insight in the biochemical properties of sensitizers.

  3. Tumor necrosis factor-alpha inhibits pre-osteoblast differentiation through its type-1 receptor.

    PubMed

    Abbas, Sabiha; Zhang, Yan-Hong; Clohisy, John C; Abu-Amer, Yousef

    2003-04-01

    Tumor necrosis factor-alpha (TNF) is a pro-inflammatory cytokine with a profound role in many skeletal diseases. The cytokine has been described as a mediator of bone loss in osteolysis and other inflammatory bone diseases. In addition to its known bone resorptive action, TNF reduces bone formation by inhibiting osteoblast differentiation. Using primary and transformed osteoblastic cells, we first document that TNF inhibits expression of alkaline phosphatase and matrix deposition, both considered markers of osteoblast differentiation. The effects are dose- and time-dependent. Core-binding factor A1 (cbfa1) is a transcription factor critical for osteoblast differentiation, and we show here that it is activated by the osteoblast differentiation agent, beta-glycerophosphate. Therefore, we investigated whether the inhibitory effects of TNF were associated with altered activity of this transcription factor. Using retardation assays, we show that TNF significantly inhibits cbfal activation by beta-glycerophosphate, manifested by reduced DNA-binding activity. Next, we turned to determine the signaling pathway by which TNF inhibits osteoblast differentiation. Utilizing animals lacking individual TNF receptors, we document that TNFr1 is required for transmitting the cytokine's inhibitory effect. In the absence of this receptor, TNF failed to impact all osteoblast differentiation markers tested. In summary, TNF blocks expression of osteoblast differentiation markers and inhibits beta-glycerophosphate-induced activation of the osteoblast differentiation factor cbfa1. Importantly, these effects are mediated via a mechanism requiring the TNF type-1 receptor.

  4. Simulating Cortical Feedback Modulation as Changes in Excitation and Inhibition in a Cortical Circuit Model

    PubMed Central

    Murray, John D.; McCormick, David A.

    2016-01-01

    Abstract Cortical feedback pathways are hypothesized to distribute context-dependent signals during flexible behavior. Recent experimental work has attempted to understand the mechanisms by which cortical feedback inputs modulate their target regions. Within the mouse whisker sensorimotor system, cortical feedback stimulation modulates spontaneous activity and sensory responsiveness, leading to enhanced sensory representations. However, the cellular mechanisms underlying these effects are currently unknown. In this study we use a simplified neural circuit model, which includes two recurrent excitatory populations and global inhibition, to simulate cortical modulation. First, we demonstrate how changes in the strengths of excitation and inhibition alter the input–output processing responses of our model. Second, we compare these responses with experimental findings from cortical feedback stimulation. Our analyses predict that enhanced inhibition underlies the changes in spontaneous and sensory evoked activity observed experimentally. More generally, these analyses provide a framework for relating cellular and synaptic properties to emergent circuit function and dynamic modulation. PMID:27595137

  5. Arsenic inhibits stem cell differentiation by altering the interplay between the Wnt3a and Notch signaling pathways

    PubMed Central

    Bain, Lisa J.; Liu, Jui-Tung; League, Ryan E.

    2016-01-01

    Millions of people are exposed to arsenic through their drinking water and food, but the mechanisms by which it impacts embryonic development are not well understood. Arsenic exposure during embryogenesis is associated with neurodevelopmental effects, reduced weight gain, and altered locomotor activity, and in vitro data indicates that arsenic exposure inhibits stem cell differentiation. This study investigated whether arsenic disrupted the Wnt3a signaling pathway, critical in the formation of myotubes and neurons, during the differentiation in P19 mouse embryonic stem cells. Cells were exposed to 0, 0.1, or 0.5 μM arsenite, with or without exogenous Wnt3a, for up to 9 days of differentiation. Arsenic exposure alone inhibits the differentiation of stem cells into neurons and skeletal myotubes, and reduces the expression of both β-catenin and GSK3β mRNA to ~55% of control levels. Co-culture of the arsenic-exposed cells with exogenous Wnt3a rescues the morphological phenotype, but does not alter transcript, protein, or phosphorylation status of GSK3β or β-catenin. However, arsenic exposure maintains high levels of Hes5 and decreases the expression of MASH1 by 2.2-fold, which are anti- and pro-myogenic and neurogenic genes, respectively, in the Notch signaling pathway. While rescue with exogenous Wnt3a reduced Hes5 levels, MASH1 levels stay repressed. Thus, while Wnt3a can partially rescue the inhibition of differentiation from arsenic, it does so by also modulating Notch target genes rather than only working through the canonical Wnt signaling pathway. These results indicate that arsenic alters the interplay between multiple signaling pathways, leading to reduced stem cell differentiation. PMID:27158593

  6. Glyphosate Inhibits PPAR Gamma Induction and Differentiation of Preadipocytes and is able to Induce Oxidative Stress.

    PubMed

    Martini, Claudia N; Gabrielli, Matías; Brandani, Javier N; Vila, María Del C

    2016-08-01

    Glyphosate-based herbicides (GF) are extensively used for weed control. Thus, it is important to investigate their putative toxic effects. We have reported that GF at subagriculture concentrations inhibits proliferation and differentiation to adipocytes of 3T3-L1 fibroblasts. In this investigation, we evaluated the effect of GF on genes upregulated during adipogenesis. GF was able to inhibit the induction of PPAR gamma, the master gene in adipogenesis but not C/EBP beta, which precedes PPAR gamma activation. GF also inhibited differentiation and proliferation of another model of preadipocyte: mouse embryonic fibroblasts. In exponentially growing 3T3-L1 cells, GF increased lipid peroxidation and the activity of the antioxidant enzyme, superoxide dismutase. We also found that proliferation was inhibited with lower concentrations of GF when time of exposure was extended. Thus, GF was able to inhibit proliferation and differentiation of preadipocytes and to induce oxidative stress, which is indicative of its ability to alter cellular physiology.

  7. Inhibition of Th17 Cell Differentiation as a Treatment for Multiple Sclerosis

    DTIC Science & Technology

    2013-10-01

    0736 TITLE: Inhibition of Th17 Cell Differentiation as a Treatment for Multiple Sclerosis PRINCIPAL INVESTIGATOR: Annalisa D’Andrea, PhD...29September2013 4. TITLE AND SUBTITLE Inhibition of Th17 Cell Differentiation as a Treatment for Multiple Sclerosis 5a. CONTRACT NUMBER 5b...were not able to screen compounds. Additionally, experiments aimed to reproduce data showing an association of miR-326 with Th17 cells failed to

  8. Bisphenol A modulates expression of sex differentiation genes in the self-fertilizing fish, Kryptolebias marmoratus.

    PubMed

    Rhee, Jae-Sung; Kim, Bo-Mi; Lee, Chang Joo; Yoon, Yong-Dal; Lee, Young-Mi; Lee, Jae-Seong

    2011-08-01

    Endocrine disrupting chemicals (EDCs) have been a major concern in the normal reproduction and development of aquatic organisms. In the teleost, steroid hormones are synthesized via the steroidogenesis pathway, and play a key physiological role in the regulation of gonadal sex differentiation. The protogynous hermaphroditic fish, Kryptolebias marmoratus is the only vertebrate capable of reproducing through internal self-fertilization. To uncover the effect of bisphenol A (BPA) on sex differentiation genes on transcription, we investigated the expression patterns of several sex differentiation-related genes such as dax1, dmrt1, mis, sf1, figlα, StAR and wt1 after BPA exposure with controls (E2 and TMX). In response to 17β-estradiol (E2) exposure, a testis-specific gene, dmrt1 mRNA was down-regulated in the gonad of the secondary male but the expression of the female-specific gene, dax1 mRNA was significantly elevated in the brain and gonad. A high level of StAR mRNA was detected in the brain and gonad of both hermaphrodite and secondary males, suggesting that the elevated expression of dax1 and StAR genes would be involved in E2 exposure. As expected, upon BPA exposure, the dmrt1 and MIS mRNA level decreased in both hermaphrodite and secondary males, while the female-specific gene, figlα mRNA level increased in the gonad of both genders. BPA showed an opposite mode of action on the expression of dax1 (induction, P>0.05) and sf1 mRNA (inhibition, P>0.05) in the brain and gonad against both genders. The sensitivity of dax1 to BPA on expression was relatively high in the secondary male. The wt1 mRNA was up-regulated in most tissues except in the liver of BPA-exposed secondary males. Regarding the time course study, the figlα mRNA level increased at 6 h after BPA exposure. In addition, BPA elevated the expression of StAR, dax1, and wt1 mRNA but repressed sf1 mRNA. In this paper, we demonstrated that BPA may modulate the expression of sex differentiation and

  9. BET N-terminal bromodomain inhibition selectively blocks Th17 cell differentiation and ameliorates colitis in mice.

    PubMed

    Cheung, Kalung; Lu, Geming; Sharma, Rajal; Vincek, Adam; Zhang, Ruihua; Plotnikov, Alexander N; Zhang, Fan; Zhang, Qiang; Ju, Ying; Hu, Yuan; Zhao, Li; Han, Xinye; Meslamani, Jamel; Xu, Feihong; Jaganathan, Anbalagan; Shen, Tong; Zhu, Hongfa; Rusinova, Elena; Zeng, Lei; Zhou, Jiachi; Yang, Jianjun; Peng, Liang; Ohlmeyer, Michael; Walsh, Martin J; Zhang, David Y; Xiong, Huabao; Zhou, Ming-Ming

    2017-03-14

    T-helper 17 (Th17) cells have important functions in adaptor immunity and have also been implicated in inflammatory disorders. The bromodomain and extraterminal domain (BET) family proteins regulate gene transcription during lineage-specific differentiation of naïve CD4(+) T cells to produce mature T-helper cells. Inhibition of acetyl-lysine binding of the BET proteins by pan-BET bromodomain (BrD) inhibitors, such as JQ1, broadly affects differentiation of Th17, Th1, and Th2 cells that have distinct immune functions, thus limiting their therapeutic potential. Whether these BET proteins represent viable new epigenetic drug targets for inflammatory disorders has remained an unanswered question. In this study, we report that selective inhibition of the first bromodomain of BET proteins with our newly designed small molecule MS402 inhibits primarily Th17 cell differentiation with a little or almost no effect on Th1 or Th2 and Treg cells. MS402 preferentially renders Brd4 binding to Th17 signature gene loci over those of housekeeping genes and reduces Brd4 recruitment of p-TEFb to phosphorylate and activate RNA polymerase II for transcription elongation. We further show that MS402 prevents and ameliorates T-cell transfer-induced colitis in mice by blocking Th17 cell overdevelopment. Thus, selective pharmacological modulation of individual bromodomains likely represents a strategy for treatment of inflammatory bowel diseases.

  10. Arsenic inhibits hedgehog signaling during P19 cell differentiation

    SciTech Connect

    Liu, Jui Tung; Bain, Lisa J.

    2014-12-15

    Arsenic is a toxicant found in ground water around the world, and human exposure mainly comes from drinking water or from crops grown in areas containing arsenic in soils or water. Epidemiological studies have shown that arsenic exposure during development decreased intellectual function, reduced birth weight, and altered locomotor activity, while in vitro studies have shown that arsenite decreased muscle and neuronal cell differentiation. The sonic hedgehog (Shh) signaling pathway plays an important role during the differentiation of both neurons and skeletal muscle. The purpose of this study was to investigate whether arsenic can disrupt Shh signaling in P19 mouse embryonic stem cells, leading to changes muscle and neuronal cell differentiation. P19 embryonic stem cells were exposed to 0, 0.25, or 0.5 μM of sodium arsenite for up to 9 days during cell differentiation. We found that arsenite exposure significantly reduced transcript levels of genes in the Shh pathway in both a time and dose-dependent manner. This included the Shh ligand, which was decreased 2- to 3-fold, the Gli2 transcription factor, which was decreased 2- to 3-fold, and its downstream target gene Ascl1, which was decreased 5-fold. GLI2 protein levels and transcriptional activity were also reduced. However, arsenic did not alter GLI2 primary cilium accumulation or nuclear translocation. Moreover, additional extracellular SHH rescued the inhibitory effects of arsenic on cellular differentiation due to an increase in GLI binding activity. Taken together, we conclude that arsenic exposure affected Shh signaling, ultimately decreasing the expression of the Gli2 transcription factor. These results suggest a mechanism by which arsenic disrupts cell differentiation. - Highlights: • Arsenic exposure decreases sonic hedgehog pathway-related gene expression. • Arsenic decreases GLI2 protein levels and transcriptional activity in P19 cells. • Arsenic exposure does not alter the levels of SHH

  11. One-Pot Evolution of Ageladine A through a Bio-Inspired Cascade towards Selective Modulators of Neuronal Differentiation.

    PubMed

    Iwata, Takayuki; Otsuka, Satoshi; Tsubokura, Kazuki; Kurbangalieva, Almira; Arai, Daisuke; Fukase, Koichi; Nakao, Yoichi; Tanaka, Katsunori

    2016-10-04

    A bio-inspired cascade reaction has been developed for the construction of the marine natural product ageladine A and a de novo array of its N1-substituted derivatives. This cascade features a 2-aminoimidazole formation that is modeled after an arginine post-translational modification and an aza-electrocyclization. It can be effectively carried out in a one-pot procedure from simple anilines or guanidines, leading to structural analogues of ageladine A that had been otherwise synthetically inaccessible. We found that some compounds out of this structurally novel library show a significant activity in modulating the neural differentiation. Namely, these compounds selectively activate or inhibit the differentiation of neural stem cells to neurons, while being negligible in the differentiation to astrocytes. This study represents a successful case in which the native biofunction of a natural product could be altered by structural modifications.

  12. Central Inhibition Ability Modulates Attention-Induced Motion Blindness

    ERIC Educational Resources Information Center

    Milders, Maarten; Hay, Julia; Sahraie, Arash; Niedeggen, Michael

    2004-01-01

    Impaired motion perception can be induced in normal observers in a rapid serial visual presentation task. Essential for this effect is the presence of motion distractors prior to the motion target, and we proposed that this attention-induced motion blindness results from high-level inhibition produced by the distractors. To investigate this, we…

  13. Serotonin differentially modulates responses to tones and frequency-modulated sweeps in the inferior colliculus.

    PubMed

    Hurley, L M; Pollak, G D

    1999-09-15

    Although almost all auditory brainstem nuclei receive serotonergic innervation, little is known about its effects on auditory neurons. We address this question by evaluating the effects of serotonin on sound-evoked activity of neurons in the inferior colliculus (IC) of Mexican free-tailed bats. Two types of auditory stimuli were used: tone bursts at the neuron's best frequency and frequency-modulated (FM) sweeps with a variety of spectral and temporal structures. There were two main findings. First, serotonin changed tone-evoked responses in 66% of the IC neurons sampled. Second, the influence of serotonin often depended on the type of signal presented. Although serotonin depressed tone-evoked responses in most neurons, its effects on responses to FM sweeps were evenly mixed between depression and facilitation. Thus in most cells serotonin had a different effect on tone-evoked responses than it did on FM-evoked responses. In some neurons serotonin depressed responses evoked by tone bursts but left the responses to FM sweeps unchanged, whereas in others serotonin had little or no effect on responses to tone bursts but substantially facilitated responses to FM sweeps. In addition, serotonin could differentially affect responses to various FM sweeps that differed in temporal or spectral structure. Previous studies have revealed that the efficacy of the serotonergic innervation is partially modulated by sensory stimuli and by behavioral states. Thus our results suggest that the population activity evoked by a particular sound is not simply a consequence of the hard wiring that connects the IC to lower and higher regions but rather is highly dynamic because of the functional reconfigurations induced by serotonin and almost certainly other neuromodulators as well.

  14. Effect of differential nerve block on inhibition of the monosynaptic reflex by vibration in man

    PubMed Central

    Moddel, G.; Best, B.; Ashby, P.

    1977-01-01

    The differential nerve block produced by ischaemia has been used in an attempt to identify the afferent nerve fibres responsible for vibratory inhibition of the monosynaptic reflex in man. It is concluded that the inhibition arises mainly from receptors in the lower leg and is carried by myelinated afferent fibres larger than A-delta. PMID:599354

  15. Photons and evolution: quantum mechanical processes modulate sexual differentiation.

    PubMed

    Davis, George E; Lowell, Walter E

    2009-09-01

    This paper will show that the fractional difference in the human gender ratio (GR) between the GR(at death) for those born in solar cycle peak years (maxima) and the GR(at death) in those born in solar cycle non-peak years (minima), e.g., 0.023, divided by Pi, yields a reasonable approximation of the quantum mechanical constant, alpha, or the fine structure constant (FSC) approximately 0.007297... or approximately 1/137. This finding is based on a sample of approximately 50 million cases using common, readily available demographic data, e.g., state of birth, birth date, death date, and gender. Physicists Nair, Geim et al. had found precisely the same fractional difference, 0.023, in the absorption of white light (sunlight) by a single-atom thick layer of graphene, a carbon skeleton resembling chicken wire fencing. This absorption fraction, when divided by Pi, yielded the FSC and was the first time this constant could "so directly be assessed practically by the naked eye". As the GR is a reflection of sexual differentiation, this paper reveals that a quantum mechanical process, as manifested by the FSC, is playing a role in the primordial process of replication, a necessary requirement of life. Successful replication is the primary engine driving evolution, which at a biochemical level, is a quantum mechanical process dependent upon photonic energy from the Sun. We propose that a quantum-mechanical, photon-driven chemical evolution preceded natural selection in biology and the mechanisms of mitosis and meiosis are manifestations of this chemical evolution in ancient seas over 3 billion years ago. Evolutionary processes became extant first in self-replicating molecules forced to adapt to high energy photons, mostly likely in the ultraviolet spectrum. These events led to evolution by natural selection as complex mixing of genetic material within species creating the variety needed to match changing environments reflecting the same process initiated at the dawn of life

  16. Extracting the differential phase in dual atom interferometers by modulating magnetic fields

    NASA Astrophysics Data System (ADS)

    Wang, Yu-Ping; Zhong, Jia-Qi; Chen, Xi; Li, Run-Bing; Li, Da-Wei; Zhu, Lei; Song, Hong-Wei; Wang, Jin; Zhan, Ming-Sheng

    2016-09-01

    We present a new scheme for measuring the differential phase in dual atom interferometers. The magnetic field is modulated in one interferometer, and the differential phase can be extracted without measuring the amplitude of the magnetic field by combining the ellipse and linear fitting methods. The gravity gradient measurements are discussed based on dual atom interferometers. Numerical simulation shows that the systematic error of the differential phase measurement is largely decreased when the duration of the magnetic field is symmetrically modulated. This combined fitting scheme has a high accuracy for measuring an arbitrary differential phase in dual atom interferometers.

  17. Anaesthetics differentially modulate the trigeminocardiac reflex excitatory synaptic pathway in the brainstem

    PubMed Central

    Wang, Xin; Gorini, Christopher; Sharp, Douglas; Bateman, Ryan; Mendelowitz, David

    2011-01-01

    Abstract The trigeminocardiac reflex (TCR) occurs upon excitation of the trigeminal nerve with a resulting bradycardia and hypotension. While several anaesthetics and analgesics have been reported to alter the incidence and strength of the TCR the mechanisms for this modulation are unclear. This study examines the mechanisms of action of ketamine, isoflurane and fentanyl on the synaptic TCR responses in both neurones in the spinal trigeminal interpolaris (Sp5I) nucleus and cardiac vagal neurones (CVNs) in the Nucleus Ambiguus (NA). Stimulation of trigeminal afferent fibres evoked an excitatory postsynaptic current (EPSC) in trigeminal neurones with a latency of 1.8 ± 0.1 ms, jitter of 625 μs, and peak amplitude of 239 ± 45 pA. Synaptic responses further downstream in the reflex pathway in the CVNs occurred with a latency of 12.1 ± 1.1 ms, jitter of 0.8–2 ms and amplitude of 57.8 ± 7.5 pA. The average conduction velocity to the Sp5I neurones was 0.94 ± 0.18 mm ms−1 indicating a mixture of A-δ and C fibres. Stimulation-evoked EPSCs in both Sp5I and CVNs were completely blocked by AMPA/kainate and NMDA glutamatergic receptor antagonists. Ketamine (10 μm) inhibited the peak amplitude and duration in Sp5I as well as more distal synapses in the CVNs. Isoflurane (300 μm) significantly inhibited, while fentanyl (1 μm) significantly enhanced, EPSC amplitude and area in CVNs but had no effect on the responses in Sp5l neurones. These findings indicate glutamatergic excitatory synaptic pathways are critical in the TCR, and ketamine, isoflurane and fentanyl differentially alter the synaptic pathways via modulation of both AMPA/kainate and NMDA receptors at different synapses in the TCR. PMID:21930602

  18. Proteomics indicates modulation of tubulin polymerization by L-menthol inhibiting human epithelial colorectal adenocarcinoma cell proliferation.

    PubMed

    Faridi, Uzma; Sisodia, Brijesh S; Shukla, Ashutosh K; Shukla, Rakesh K; Darokar, Mahendra P; Dwivedi, Upendra N; Shasany, Ajit K

    2011-05-01

    Menthol is a naturally occurring cyclic monoterpene used in oral hygiene products, confectionary, pharmaceuticals, cosmetics, pesticides, and as a flavoring agent. In the present study, we analyzed the differentially expressing proteome in L-menthol-treated Caco-2 cell line as it was found to inhibit cell proliferation. Interestingly, free tubulin proteins were observed to be limited after menthol treatment. Semiquantitative RT-PCR with α-tubulin primers showed no change in the level of RNA expression in menthol-treated cell line. However, tubulin polymerization assay with menthol indicated a trend similar to taxol in promoting microtubule assembly. Further, physical counting of apoptotic nuclei and active caspase-3 assays confirmed onset of apoptosis though the rate was slower as compared with that of taxol treatment. This study is the first report of a monoterpene L-menthol modulating tubulin polymerization and apoptosis to inhibit cancer cell proliferation.

  19. Sodium hydrogen sulfide inhibits nicotine and lipopolysaccharide-induced osteoclastic differentiation and reversed osteoblastic differentiation in human periodontal ligament cells.

    PubMed

    Lee, Sun-Kyung; Chung, Jong-Hyuk; Choi, Sung-Chul; Auh, Q-Schick; Lee, Young-Man; Lee, Sang-Im; Kim, Eun-Cheol

    2013-05-01

    Although previous studies have demonstrated that hydrogen sulfide (H(2)S) stimulated or inhibited osteoclastic differentiation, little is known about the effects of H(2)S on the differentiation of osteoblasts and osteoclasts. To determine the possible bioactivities of H(2)S on bone metabolism, we investigated the in vitro effects of H(2)S on cytotoxicity, osteoblastic, and osteoclastic differentiation as well as the underlying mechanism in lipopolysaccharide (LPS) and nicotine-stimulated human periodontal ligament cells (hPDLCs). The H(2)S donor, NaHS, protected hPDLCs from nicotine and LPS-induced cytotoxicity and recovered nicotine- and LPS-downregulated osteoblastic differentiation, such as alkaline phosphatase (ALP) activity, mRNA expression of osteoblasts, including ALP, osteopontin (OPN), and osteocalcin (OCN), and mineralized nodule formation. Concomitantly, NaHS inhibited the differentiation of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts in mouse bone marrow cells and blocked nicotine- and LPS-induced osteoclastogenesis regulatory molecules, such as RANKL, OPG, M-CSF, MMP-9, TRAP, and cathepsin K mRNA. NaHS blocked nicotine and LPS-induced activation of p38, ERK, MKP-1, PI3K, PKC, and PKC isoenzymes, and NF-κB. The effects of H(2)S on nicotine- and LPS-induced osteoblastic and osteoclastic differentiation were remarkably reversed by MKP-1 enzyme inhibitor (vanadate) and expression inhibitor (triptolide). Taken together, we report for the first time that H(2)S inhibited cytotoxicity and osteoclastic differentiation and recovered osteoblastic differentiation in a nicotine- and periodontopathogen-stimulated hPDLCs model, which has potential therapeutic value for treatment of periodontal and inflammatory bone diseases.

  20. Differential Modulation of Synaptic Strength and Timing Regulate Synaptic Efficacy in a Motor Network

    PubMed Central

    Brown, Jessica M.; Kvarta, Mark D.; Lu, Jay Y. J.; Schneider, Lauren R.; Nadim, Farzan; Harris-Warrick, Ronald M.

    2011-01-01

    Neuromodulators modify network output by altering neuronal firing properties and synaptic strength at multiple sites; however, the functional importance of each site is often unclear. We determined the importance of monoamine modulation of a single synapse for regulation of network cycle frequency in the oscillatory pyloric network of the lobster. The pacemaker kernel of the pyloric network receives only one chemical synaptic feedback, an inhibitory synapse from the lateral pyloric (LP) neuron to the pyloric dilator (PD) neurons, which can limit cycle frequency. We measured the effects of dopamine (DA), octopamine (Oct), and serotonin (5HT) on the strength of the LP→PD synapse and the ability of the modified synapse to regulate pyloric cycle frequency. DA and Oct strengthened, whereas 5HT weakened, LP→PD inhibition. Surprisingly, the DA-strengthened LP→PD synapse lost its ability to slow the pyloric oscillations, whereas the 5HT-weakened LP→PD synapse gained a greater influence on the oscillations. These results are explained by monoamine modulation of factors that determine the firing phase of the LP neuron in each cycle. DA acts via multiple mechanisms to phase-advance the LP neuron into the pacemaker's refractory period, where the strengthened synapse has little effect. In contrast, 5HT phase-delays LP activity into a region of greater pacemaker sensitivity to LP synaptic input. Only Oct enhanced LP regulation of cycle period simply by enhancing LP→PD synaptic strength. These results show that modulation of the strength and timing of a synaptic input can differentially affect the synapse's efficacy in the network. PMID:21047938

  1. Differential effects of gram-positive and gram-negative bacterial products on morphine induced inhibition of phagocytosis

    PubMed Central

    Jana, Ninkovic; Vidhu, Anand; Raini, Dutta; Zhang, Li; Saluja, Anuj; Meng, Jingjing; Lisa, Koodie; Santanu, Banerjee; Sabita, Roy

    2016-01-01

    Opioid drug abusers have a greater susceptibility to gram positive (Gram (+)) bacterial infections. However, the mechanism underlying opioid modulation of Gram (+) versus Gram (−) bacterial clearance has not been investigated. In this study, we show that opioid treatment resulted in reduced phagocytosis of Gram (+), when compared to Gram (−) bacteria. We further established that LPS priming of chronic morphine treated macrophages leads to potentiated phagocytosis and killing of both Gram (+) and Gram (−) bacteria in a P-38 MAP kinase dependent signaling pathway. In contrast, LTA priming lead to inhibition of both phagocytosis and bacterial killing. This study demonstrates for the first time the differential effects of TLR4 and TLR2 agonists on morphine induced inhibition of phagocytosis. Our results suggest that the incidence and severity of secondary infections with Gram (+) bacteria would be higher in opioid abusers. PMID:26891899

  2. Differential effects of gram-positive and gram-negative bacterial products on morphine induced inhibition of phagocytosis.

    PubMed

    Ninkovic, Jana; Jana, Ninkovic; Anand, Vidhu; Vidhu, Anand; Dutta, Raini; Raini, Dutta; Zhang, Li; Saluja, Anuj; Meng, Jingjing; Koodie, Lisa; Lisa, Koodie; Banerjee, Santanu; Santanu, Banerjee; Roy, Sabita; Sabita, Roy

    2016-02-19

    Opioid drug abusers have a greater susceptibility to gram positive (Gram (+)) bacterial infections. However, the mechanism underlying opioid modulation of Gram (+) versus Gram (-) bacterial clearance has not been investigated. In this study, we show that opioid treatment resulted in reduced phagocytosis of Gram (+), when compared to Gram (-) bacteria. We further established that LPS priming of chronic morphine treated macrophages leads to potentiated phagocytosis and killing of both Gram (+) and Gram (-) bacteria in a P-38 MAP kinase dependent signaling pathway. In contrast, LTA priming lead to inhibition of both phagocytosis and bacterial killing. This study demonstrates for the first time the differential effects of TLR4 and TLR2 agonists on morphine induced inhibition of phagocytosis. Our results suggest that the incidence and severity of secondary infections with Gram (+) bacteria would be higher in opioid abusers.

  3. Inhibition of proliferation and induction of differentiation of glioma cells with Datura stramonium agglutinin.

    PubMed

    Sasaki, T; Yamazaki, K; Yamori, T; Endo, T

    2002-10-07

    We found that a lectin, Datura stramonium agglutinin, induced irreversible differentiation in C6 glioma cells. The differentiated cells had long processes, a low rate of proliferation and a high content of glial fibrillary acidic protein. When the medium was replaced with Datura stramonium agglutinin-free medium after 1 h, cell proliferation continued to be inhibited. Experiments with several other lectins indicated that both recognition of linear N-acetyllactosamine repeats and recognition of multiantennary units of cell-surface glycans were required for the inhibition of C6 proliferation. Proliferation of four human glial tumour cells was also inhibited by Datura stramonium agglutinin. Further, these differentiated human glial tumour cells had long processes and a high content of glial fibrillary acidic protein similar to differentiated C6 glioma cells. Taken together, these observations suggest that Datura stramonium agglutinin may be useful as a new therapy for treating glioma without side effects.

  4. Myostatin inhibits myoblast differentiation by down-regulating MyoD expression.

    PubMed

    Langley, Brett; Thomas, Mark; Bishop, Amy; Sharma, Mridula; Gilmour, Stewart; Kambadur, Ravi

    2002-12-20

    Myostatin, a negative regulator of myogenesis, is shown to function by controlling the proliferation of myoblasts. In this study we show that myostatin is an inhibitor of myoblast differentiation and that this inhibition is mediated through Smad 3. In vitro, increasing concentrations of recombinant mature myostatin reversibly blocked the myogenic differentiation of myoblasts, cultured in low serum media. Western and Northern blot analysis indicated that addition of myostatin to the low serum culture media repressed the levels of MyoD, Myf5, myogenin, and p21 leading to the inhibition of myogenic differentiation. The transient transfection of C(2)C(12) myoblasts with MyoD expressing constructs did not rescue myostatin-inhibited myogenic differentiation. Myostatin signaling specifically induced Smad 3 phosphorylation and increased Smad 3.MyoD association, suggesting that Smad 3 may mediate the myostatin signal by interfering with MyoD activity and expression. Consistent with this, the expression of dominant-negative Smad3 rescued the activity of a MyoD promoter-reporter in C(2)C(12) myoblasts treated with myostatin. Taken together, these results suggest that myostatin inhibits MyoD activity and expression via Smad 3 resulting in the failure of the myoblasts to differentiate into myotubes. Thus we propose that myostatin plays a critical role in myogenic differentiation and that the muscular hyperplasia and hypertrophy seen in animals that lack functional myostatin is because of deregulated proliferation and differentiation of myoblasts.

  5. Apolipoprotein E inhibits osteoclast differentiation via regulation of c-Fos, NFATc1 and NF-κB

    SciTech Connect

    Kim, Woo-Shin; Kim, Hyung Joon; Lee, Zang Hee; Lee, Youngkyun; Kim, Hong-Hee

    2013-02-15

    Apolipoprotein E (ApoE) plays a major role in the transport and metabolism of lipid. Other functions of ApoE include modulation of innate and adaptive immune responses. The expression of ApoE in osteoblasts and its relevance with bone formation have also been reported. However, the effect of ApoE on osteoclasts has not yet been examined. Here, we investigated the role of ApoE in osteoclast differentiation using bone marrow-derived macrophages (BMMs) and RAW264.7 cells. We found a down-regulation of ApoE gene expression during osteoclastic differentiation of those cells. Overexpression of ApoE in BMMs and RAW264.7 cells significantly blocked the induction of c-Fos and nuclear factor of activated T cell c1 (NFATc1), transcription factors critical for expression of osteoclast marker genes, by receptor activator of nuclear factor κB ligand (RANKL), the osteoclast differentiation factor. ApoE inhibited osteoclast differentiation, as measured by decreased number of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells (MNCs). In addition, ApoE reduced the expression of dendritic cell-specific transmembrane protein (DC-STAMP) and ATPase, H{sup +} transporting, lysosomal 38 kDa, V0 subunit d2 (ATP6v0d2), genes involved in cell–cell fusion during osteoclastogenesis. Knock-down of ApoE using a specific siRNA promoted the RANKL-mediated induction of osteoclast differentiation. While ApoE did not affect the activation of ERK, JNK, and p38 MAPK signaling pathways by RANKL, the phosphorylation of p65 trans-activation domain on serine 536 and transcription activity of NF-κB were reduced by ApoE overexpression. These findings suggest that ApoE plays an inhibitory role in osteoclast differentiation via the suppression of RANKL-dependent activation of NF-κB and induction of c-Fos and NFATc1. - Highlights: ► Apolipoprotein E (ApoE) significantly inhibited osteoclast differentiation and activation of NF-κB. ► ApoE decreased the induction of osteoclast marker

  6. Inhibition of miR-29c promotes proliferation, and inhibits apoptosis and differentiation in P19 embryonic carcinoma cells.

    PubMed

    Chen, Bin; Song, Guixian; Liu, Ming; Qian, Lingmei; Wang, Lihua; Gu, Haitao; Shen, Yahui

    2016-03-01

    In our previous study, the upregulation of microRNA (miR)-29c was identified in the mother of a fetus with a congenital heart defect. However, the functional and regulatory mechanisms of miR‑29c in the development of the heart remain to be elucidated. In the present study, the role and mechanism of miR‑29c inhibition in heart development were investigated in an embryonic carcinoma cell model. Inhibition of miR‑29c promoted proliferation, and suppressed the apoptosis and differentiation of P19 cells. It was also demonstrated that Wingless‑related MMTV integration site 4 (Wnt4) was a target of miR‑29c, determined using bioinformatic analysis combined with luciferase assays. The inhibition of miR‑29c stimulated the WNT4/β‑catenin pathway, promoting proliferation of the P19 cells, but suppressing their differentiation into cardiomyocytes. Furthermore, the inhibition of miR‑29c promoted the expression of B cell lymphoma‑2 and inhibited cell apoptosis. These results demonstrate the significance of miR‑29c in the process of cardiac development and suggest that miR-29c dysregulation may be associated with the occurrence of CHD. Thus, miR-29c may have therapeutic potential in the future.

  7. Atmospheric-pressure plasma-irradiation inhibits mouse embryonic stem cell differentiation to mesoderm and endoderm but promotes ectoderm differentiation

    NASA Astrophysics Data System (ADS)

    Miura, Taichi; Hamaguchi, Satoshi; Nishihara, Shoko

    2016-04-01

    Recently, various effects of low-temperature atmospheric-pressure plasma irradiation on living cells have been demonstrated, such as tissue sterilization, blood coagulation, angiogenesis, wound healing, and tumor elimination. However, the effect of plasma-irradiation on the differentiation of mouse embryonic stem cells (mESCs) has not yet been clarified. A large number of reactive species are generated by plasma-irradiation in medium, of which hydrogen peroxide (H2O2) is one of the main species generated. Here, we investigated the effect of plasma-irradiation on the differentiation of mESCs using an embryoid body (EB) formation assay with plasma-irradiated medium or H2O2-supplemented non-irradiated medium. Our findings demonstrated that plasma-irradiated medium potently inhibits the differentiation from mESCs to mesoderm and endoderm by inhibiting Wnt signaling as determined by quantitative polymerase chain reaction and immunoblotting analyses. In contrast, both the plasma-irradiated medium and H2O2-supplemented non-irradiated medium enhanced the differentiation to epiblastoid, ectodermal, and neuronal lineages by activation of fibroblast growth factor 4 (FGF4) signaling, suggesting that these effects are caused by the H2O2 generated by plasma-irradiation in medium. However, in each case, the differentiation to glial cells remained unaffected. This study is the first demonstration that plasma-irradiation affects the differentiation of mESCs by the regulation of Wnt and FGF4 signaling pathways.

  8. Selective estrogen receptor modulators differentially alter the immune response of gilthead seabream juveniles.

    PubMed

    Rodenas, M C; Cabas, I; García-Alcázar, A; Meseguer, J; Mulero, V; García-Ayala, A

    2016-05-01

    17α-ethynylestradiol (EE2), a synthetic estrogen used in oral contraceptives and hormone replacement therapy, tamoxifen (Tmx), a selective estrogen-receptor modulator used in hormone replacement therapy, and G1, a G protein-coupled estrogen receptor (GPER) selective agonist, differentially increased the hepatic vitellogenin (vtg) gene expression and altered the immune response in adult gilthead seabream (Sparus aurata L.) males. However, no information exists on the effects of these compounds on the immune response of juveniles. This study aims, for the first time, to investigate the effects of the dietary intake of EE2, Tmx or G1 on the immune response of gilthead seabream juveniles and the capacity of the immune system of the specimens to recover its functionality after ceasing exposures (recovery period). The specimens were immunized with hemocyanin in the presence of aluminium adjuvant 1 (group A) or 120 (group B) days after the treatments ceased (dpt). The results indicate that EE2 and Tmx, but not G1, differentially promoted a transient alteration in hepatic vtg gene expression. Although all three compounds did not affect the production of reactive oxygen intermediates, they inhibited the induction of interleukin-1β (il1b) gene expression after priming. Interestingly, although Tmx increased the percentage of IgM-positive cells in both head kidney and spleen during the recovery period, the antibody response of vaccinated fish varied depending on the compound used and when the immunization was administered. Taken together, our results suggest that these compounds differentially alter the capacity of fish to respond to infection during ontogeny and, more interestingly, that the adaptive immune response remained altered to an extent that depends on the compound.

  9. Protein-arginine Methyltransferase 1 Suppresses Megakaryocytic Differentiation via Modulation of the p38 MAPK Pathway in K562 Cells*

    PubMed Central

    Chang, Yuan-I; Hua, Wei-Kai; Yao, Chao-Ling; Hwang, Shiaw-Min; Hung, Yi-Chi; Kuan, Chih-Jen; Leou, Jiun-Shyang; Lin, Wey-Jinq

    2010-01-01

    Protein-arginine methyltransferase 1 (PRMT1) plays pivotal roles in various cellular processes. However, its role in megakaryocytic differentiation has yet to be investigated. Human leukemia K562 cells have been used as a model to study hematopoietic differentiation. In this study, we report that ectopic expression of HA-PRMT1 in K562 cells suppressed phorbol 12-myristate 13-acetate (PMA)-induced megakaryocytic differentiation as demonstrated by changes in cytological characteristics, adhesive properties, and CD41 expression, whereas knockdown of PRMT1 by small interference RNA promoted differentiation. Impairment of the methyltransferase activity of PRMT1 diminished the suppressive effect. These results provide evidence for a novel role of PRMT1 in negative regulation of megakaryocytic differentiation. Activation of ERK MAPK has been shown to be essential for megakaryocytic differentiation, although the role of p38 MAPK is still poorly understood. We show that knockdown of p38α MAPK or treatment with the p38 inhibitor SB203580 significantly enhanced PMA-induced megakaryocytic differentiation. Further investigation revealed that PRMT1 promotes activation of p38 MAPK without inhibiting activation of ERK MAPK. In p38α knockdown cells, PRMT1 could no longer suppress differentiation. In contrast, enforced expression of p38α MAPK suppressed PMA-induced megakaryocytic differentiation of parental K562 as well as PRMT1-knockdown cells. We propose modulation of the p38 MAPK pathway by PRMT1 as a novel mechanism regulating megakaryocytic differentiation. This study thus provides a new perspective on the promotion of megakaryopoiesis. PMID:20442406

  10. The effects and inhibition of frequency offset on differential phase-shift keying detection

    NASA Astrophysics Data System (ADS)

    Guo, Hao; Zhou, Jing; Su, Shaojing; Pan, Zhongming

    2015-10-01

    Differential phase-shift keying (DPSK) has been widely implemented and developed in high-speed optical communication systems. The low error rate detection at high access rate is one of the considerable issues in practical engineering application. Balanced detection based on fiber Mach-Zehnder delay interferometer (MZDI) is the typical optical DPSK signal detecting method. It requires that the free spectrum range (FSR) of the MZDI equals the reciprocal of symbol period of the DPSK signal. For the reasons of ambient temperature variation and nonlinear phase noise, a dynamic frequency offset always exists between the FSR and the reciprocal of symbol period. That may introduce some optical signal-to-noise ratio (OSNR) costs and fault detections. Therefore, it is significant to inhibit the frequency offset on DPSK detection. In this paper, firstly, we discuss the effects of frequency offset on DPSK detection, and realize the conclusion that frequency offset is virtually equivalent to an additional phase difference between adjacent symbols. Secondly, through simulation, we analyze the feasibility of DPSK detection in the presence of a definite range of frequency offset, and present the quantitative computation of effective coverage, duty cycle, and optimal sampling time of symbol interference. Some issues which should be considered in practical implementation are also discussed. Finally, according to the relationship among phase difference, temperature and voltage, we propose a phase difference compensation scheme which can automatically adjust the voltage for optimal detections, and dynamically track the changing of ambient temperature and nonlinear phase noise. Furthermore, we ascertain the performance of the voltage requested for implementing the scheme. The scheme can be also developed to quadrature phase-shift keying (QPSK) and differential QPSK (DQPSK) modulation situations.

  11. Inhibition of chaotic escape from a potential well using small parametric modulations

    SciTech Connect

    Chacon, R.; Balibrea, F.; Lopez, M.A.

    1996-11-01

    It is shown theoretically for the first time that, depending on its period, amplitude, and initial phase, a periodic parametric modulation can suppress a chaotic escape from a potential well. The instance of the Helmholtz oscillator is used to demonstrate, by means of Melnikov{close_quote}s method, that parametric modulations of the linear or quadratic potential terms inhibit chaotic escape when certain resonance conditions are met. {copyright} {ital 1996 American Institute of Physics.}

  12. Synthesis and SAR study of modulators inhibiting tRXRα-dependent AKT activation

    PubMed Central

    Wang, Zhi-Gang; Chen, Liqun; Chen, Jiebo; Zheng, Jian-Feng; Gao, Weiwei; Zeng, Zhiping; Zhou, Hu; Zhang, Xiao-kun; Huang, Pei-Qiang; Su, Ying

    2013-01-01

    RXRα represents an intriguing and unique target for pharmacologic interventions. We recently showed that Sulindac and a designed analog could bind to RXRα and modulate its biological activity, including inhibition of the interaction of an N-terminally truncated RXRα (tRXRα) with the p85α regulatory subunit of phosphatidylinositol-3-OH kinase (PI3K). Here we report the synthesis, testing and SAR of a series of novel analogs of Sulindac as potential modulators for inhibiting tRXRα-dependent AKT activation. A new compound 30 was identified to have improved biological activity. PMID:23434637

  13. Modulation of motor inhibition by subthalamic stimulation in obsessive-compulsive disorder

    PubMed Central

    Kibleur, A; Gras-Combe, G; Benis, D; Bastin, J; Bougerol, T; Chabardès, S; Polosan, M; David, O

    2016-01-01

    High-frequency deep brain stimulation of the subthalamic nucleus can be used to treat severe obsessive-compulsive disorders that are refractory to conventional treatments. The mechanisms of action of this approach possibly rely on the modulation of associative-limbic subcortical–cortical loops, but remain to be fully elucidated. Here in 12 patients, we report the effects of high-frequency stimulation of the subthalamic nucleus on behavior, and on electroencephalographic responses and inferred effective connectivity during motor inhibition processes involved in the stop signal task. First, we found that patients were faster to respond and had slower motor inhibition processes when stimulated. Second, the subthalamic stimulation modulated the amplitude and delayed inhibition-related electroencephalographic responses. The power of reconstructed cortical current densities decreased in the stimulation condition in a parietal–frontal network including cortical regions of the inhibition network such as the superior parts of the inferior frontal gyri and the dorsolateral prefrontal cortex. Finally, dynamic causal modeling revealed that the subthalamic stimulation was more likely to modulate efferent connections from the basal ganglia, modeled as a hidden source, to the cortex. The connection from the basal ganglia to the right inferior frontal gyrus was significantly decreased by subthalamic stimulation. Beyond motor inhibition, our study thus strongly suggests that the mechanisms of action of high-frequency subthalamic stimulation are not restricted to the subthalamic nucleus, but also involve the modulation of distributed subcortical–cortical networks. PMID:27754484

  14. Ginsenoside Re Inhibits Osteoclast Differentiation in Mouse Bone Marrow-Derived Macrophages and Zebrafish Scale Model

    PubMed Central

    Park, Chan-Mi; Kim, Hye-Min; Kim, Dong Hyun; Han, Ho-Jin; Noh, Haneul; Jang, Jae-Hyuk; Park, Soo-Hyun; Chae, Han-Jung; Chae, Soo-Wan; Ryu, Eun Kyoung; Lee, Sangku; Liu, Kangdong; Liu, Haidan; Ahn, Jong-Seog; Kim, Young Ock; Kim, Bo-Yeon; Soung, Nak-Kyun

    2016-01-01

    Ginsenosides, which are the active materials of ginseng, have biological functions that include anti-osteoporotic effects. Aqueous ginseng extract inhibits osteoclast differentiation induced by receptor activator of NF-κB ligand (RANKL). Aqueous ginseng extract produces chromatography peaks characteristic of ginsenosides. Among these peaks, ginsenoside Re is a major component. However, the preventive effects of ginsenoside Re against osteoclast differentiation are not known. We studied the effect of ginsenoside Re on osteoclast differentiation, RANKL-induced tartrate-resistant acid phosphatase (TRAP) activity, and formation of multinucleated osteoclasts in vitro. Ginsenoside Re hampered osteoclast differentiation in a dose-dependent manner. In an in vivo zebrafish model, aqueous ginseng extract and ginsenoside Re had anti-osteoclastogenesis effects. These findings suggest that both aqueous ginseng extract and ginsenoside Re prevent bone resorption by inhibiting osteoclast differentiation. Ginsenoside Re could be important for promoting bone health. PMID:27927007

  15. miR-1827 inhibits osteogenic differentiation by targeting IGF1 in MSMSCs

    PubMed Central

    Zhu, ShuangXi; Peng, Wei; Li, Xiang; Weng, JunQuan; Zhang, Xing; Guo, JunBing; Huang, DaiYing; Rong, Qiong; Chen, SongLing

    2017-01-01

    We recently reported that maxillary sinus membrane stem cells (MSMSCs) have osteogenic potential. However, the biological mechanisms of bone formation remain unclear. In this study, we investigated the role and mechanisms of microRNAs (miRNAs) in the osteogenic differentiation of MSMSCs. The expression of miRNAs was determined in differentiated MSMSCs by comprehensive miRNA microarray analysis and quantitative RT-PCR (qRT-PCR). We selected miR-1827 for functional follow-up studies to explore its significance in MSMSCs. Here, miR-1827 was found to be up-regulated during osteogenic differentiation of MSMSCs. Over expression of miR-1827 inhibited osteogenic differentiation of MSMSCs in vitro, whereas the repression of miR-1827 greatly promoted cell differentiation. Further experiments confirmed that insulin-like growth factor 1 (IGF1) is a direct target of miR-1827. miR-1827 inhibited osteogenic differentiation partially via IGF1, which in turn is a positive regulator of osteogenic differentiation. Moreover, miR-1827 suppressed ectopic bone formation and silencing of miR-1827 led to increased bone formation in vivo. In summary, this study is the first to demonstrate that miR-1827 can regulate osteogenic differentiation. The increase in miR-1827 expression observed during osteogenesis is likely a negative feedback mechanism, thus offering a potential therapeutic target to address inadequate bone volume for dental implantation through inhibiting miR-1827. PMID:28387248

  16. Tonic Inhibition of Accumbal Spiny Neurons by Extrasynaptic α4βδ GABAA Receptors Modulates the Actions of Psychostimulants

    PubMed Central

    Maguire, Edward P.; Macpherson, Tom; Swinny, Jerome D.; Dixon, Claire I.; Herd, Murray B.; Belelli, Delia; Stephens, David N.

    2014-01-01

    Within the nucleus accumbens (NAc), synaptic GABAA receptors (GABAARs) mediate phasic inhibition of medium spiny neurons (MSNs) and influence behavioral responses to cocaine. We demonstrate that both dopamine D1- and D2-receptor-expressing MSNs (D-MSNs) additionally harbor extrasynaptic GABAARs incorporating α4, β, and δ subunits that mediate tonic inhibition, thereby influencing neuronal excitability. Both the selective δ-GABAAR agonist THIP and DS2, a selective positive allosteric modulator, greatly increased the tonic current of all MSNs from wild-type (WT), but not from δ−/− or α4−/− mice. Coupling dopamine and tonic inhibition, the acute activation of D1 receptors (by a selective agonist or indirectly by amphetamine) greatly enhanced tonic inhibition in D1-MSNs but not D2-MSNs. In contrast, prolonged D2 receptor activation modestly reduced the tonic conductance of D2-MSNs. Behaviorally, WT and constitutive α4−/− mice did not differ in their expression of cocaine-conditioned place preference (CPP). Importantly, however, mice with the α4 deletion specific to D1-expressing neurons (α4D1−/−) showed increased CPP. Furthermore, THIP administered systemically or directly into the NAc of WT, but not α4−/− or α4D1−/− mice, blocked cocaine enhancement of CPP. In comparison, α4D2−/− mice exhibited normal CPP, but no cocaine enhancement. In conclusion, dopamine modulation of GABAergic tonic inhibition of D1- and D2-MSNs provides an intrinsic mechanism to differentially affect their excitability in response to psychostimulants and thereby influence their ability to potentiate conditioned reward. Therefore, α4βδ GABAARs may represent a viable target for the development of novel therapeutics to better understand and influence addictive behaviors. PMID:24431441

  17. Lung cancer-derived Dickkopf1 is associated with bone metastasis and the mechanism involves the inhibition of osteoblast differentiation

    SciTech Connect

    Chu, Tianqing; Teng, Jiajun; Jiang, Liyan; Zhong, Hua; Han, Baohui

    2014-01-17

    Highlights: •DKK1 level was associated with NSCLC bone metastases. •Lung tumor cells derived DKK1 inhibited osteoblast differentiation. •Lung tumor cells derived DKK1 modulates β-catenin and RUNX2. -- Abstract: Wnt/β-catenin signaling and Dickkopf1 (DKK1) play important roles in the progression of lung cancer, which preferably metastasizes to skeleton. But the role of them in bone dissemination is poorly understood. This study aims to define the role of DKK1 in lung cancer bone metastases and investigate the underlying mechanism. Our results demonstrated that DKK1 over-expression was a frequent event in non-small-cell lung cancer (NSCLC) blood samples, and serous DKK1 level was much higher in bone metastatic NSCLC compared to non-bone metastatic NSCLC. We also found that conditioned medium from DKK1 over-expressing lung cancer cells inhibited the differentiation of osteoblast, determined by alkaline phosphatase activity and osteocalcin secretion, whereas the conditioned medium from DKK1 silencing lung cancer cells exhibited the opposite effects. Mechanistically, DKK1 reduced the level of β-catenin and RUNX2, as well as inhibiting the nuclear translocation of β-catenin. Taken together, these results suggested that lung cancer-produced DKK1 may be an important mechanistic link between NSCLC and bone metastases, and targeting DKK1 may be an effective method to treat bone metastase of NSCLC.

  18. Doxycycline Inhibits IL-17-Stimulated MMP-9 Expression by Downregulating ERK1/2 Activation: Implications in Myogenic Differentiation

    PubMed Central

    Obradović, Hristina; Krstić, Jelena; Kukolj, Tamara; Đorđević, Ivana Okić; Jauković, Aleksandra; Jovčić, Gordana

    2016-01-01

    Interleukin 17 (IL-17) is a cytokine with pleiotropic effects associated with several inflammatory diseases. Although elevated levels of IL-17 have been described in inflammatory myopathies, its role in muscle remodeling and regeneration is still unknown. Excessive extracellular matrix degradation in skeletal muscle is an important pathological consequence of many diseases involving muscle wasting. In this study, the role of IL-17 on the expression of matrix metalloproteinase- (MMP-) 9 in myoblast cells was investigated. The expression of MMP-9 after IL-17 treatment was analyzed in mouse myoblasts C2C12 cell line. The increase in MMP-9 production by IL-17 was concomitant with its capacity to inhibit myogenic differentiation of C2C12 cells. Doxycycline (Doxy) treatment protected the myogenic capacity of myoblasts from IL-17 inhibition and, moreover, increased myotubes hypertrophy. Doxy blocked the capacity of IL-17 to stimulate MMP-9 production by regulating IL-17-induced ERK1/2 MAPK activation. Our results imply that MMP-9 mediates IL-17's capacity to inhibit myoblast differentiation during inflammatory diseases and indicate that Doxy can modulate myoblast response to inflammatory induction by IL-17. PMID:28042204

  19. Manganese inhibits the ability of astrocytes to promote neuronal differentiation

    SciTech Connect

    Giordano, Gennaro; Pizzurro, Daniella; VanDeMark, Kathryn; Guizzetti, Marina; Costa, Lucio G.

    2009-10-15

    Manganese (Mn) is a known neurotoxicant and developmental neurotoxicant. As Mn has been shown to accumulate in astrocytes, we sought to investigate whether Mn would alter astrocyte-neuronal interactions, specifically the ability of astrocytes to promote differentiation of neurons. We found that exposure of rat cortical astrocytes to Mn (50-500 {mu}M) impaired their ability to promote axonal and neurite outgrowth in hippocampal neurons. This effect of Mn appeared to be mediated by oxidative stress, as it was reversed by antioxidants (melatonin and PBN) and by increasing glutathione levels, while it was potentiated by glutathione depletion in astrocytes. As the extracellular matrix protein fibronectin plays an important role in astrocyte-mediated neuronal neurite outgrowth, we also investigated the effect of Mn on fibronectin. Mn caused a concentration-dependent decrease of fibronectin protein and mRNA in astrocytes lysate and of fibronectin protein in astrocyte medium; these effects were also antagonized by antioxidants. Exposure of astrocytes to two oxidants, H{sub 2}O{sub 2} and DMNQ, similarly impaired their neuritogenic action, and led to a decreased expression of fibronectin. Mn had no inhibitory effect on neurite outgrowth when applied directly onto hippocampal neurons, where it actually caused a small increase in neuritogenesis. These results indicate that Mn, by targeting astrocytes, affects their ability to promote neuronal differentiation by a mechanism which is likely to involve oxidative stress.

  20. Nitric oxide scavengers differentially inhibit ammonia oxidation in ammonia-oxidizing archaea and bacteria.

    PubMed

    Sauder, Laura A; Ross, Ashley A; Neufeld, Josh D

    2016-04-01

    Differential inhibitors are important for measuring the relative contributions of microbial groups, such as ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), to biogeochemical processes in environmental samples. In particular, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) represents a nitric oxide scavenger used for the specific inhibition of AOA, implicating nitric oxide as an intermediate of thaumarchaeotal ammonia oxidation. This study investigated four alternative nitric oxide scavengers for their ability to differentially inhibit AOA and AOB in comparison to PTIO. Caffeic acid, curcumin, methylene blue hydrate and trolox were tested onNitrosopumilus maritimus, two unpublished AOA representatives (AOA-6f and AOA-G6) as well as the AOB representative Nitrosomonas europaea All four scavengers inhibited ammonia oxidation by AOA at lower concentrations than for AOB. In particular, differential inhibition of AOA and AOB by caffeic acid (100 μM) and methylene blue hydrate (3 μM) was comparable to carboxy-PTIO (100 μM) in pure and enrichment culture incubations. However, when added to aquarium sponge biofilm microcosms, both scavengers were unable to inhibit ammonia oxidation consistently, likely due to degradation of the inhibitors themselves. This study provides evidence that a variety of nitric oxide scavengers result in differential inhibition of ammonia oxidation in AOA and AOB, and provides support to the proposed role of nitric oxide as a key intermediate in the thaumarchaeotal ammonia oxidation pathway.

  1. In vitro developmental toxicity test detects inhibition of stem cell differentiation by silica nanoparticles

    SciTech Connect

    Park, Margriet V.D.Z. Annema, Wijtske; Salvati, Anna; Lesniak, Anna; Elsaesser, Andreas; Barnes, Clifford; McKerr, George; Howard, C. Vyvyan; Lynch, Iseult; Dawson, Kenneth A.; Piersma, Aldert H.; Jong, Wim H. de

    2009-10-01

    While research into the potential toxic properties of nanomaterials is now increasing, the area of developmental toxicity has remained relatively uninvestigated. The embryonic stem cell test is an in vitro screening assay used to investigate the embryotoxic potential of chemicals by determining their ability to inhibit differentiation of embryonic stem cells into spontaneously contracting cardiomyocytes. Four well characterized silica nanoparticles of various sizes were used to investigate whether nanomaterials are capable of inhibition of differentiation in the embryonic stem cell test. Nanoparticle size distributions and dispersion characteristics were determined before and during incubation in the stem cell culture medium by means of transmission electron microscopy (TEM) and dynamic light scattering. Mouse embryonic stem cells were exposed to silica nanoparticles at concentrations ranging from 1 to 100 {mu}g/ml. The embryonic stem cell test detected a concentration dependent inhibition of differentiation of stem cells into contracting cardiomyocytes by two silica nanoparticles of primary size 10 (TEM 11) and 30 (TEM 34) nm while two other particles of primary size 80 (TEM 34) and 400 (TEM 248) nm had no effect up to the highest concentration tested. Inhibition of differentiation of stem cells occurred below cytotoxic concentrations, indicating a specific effect of the particles on the differentiation of the embryonic stem cells. The impaired differentiation of stem cells by such widely used particles warrants further investigation into the potential of these nanoparticles to migrate into the uterus, placenta and embryo and their possible effects on embryogenesis.

  2. Foxp3+ T cells inhibit antitumor immune memory modulated by mTOR inhibition.

    PubMed

    Wang, Yanping; Sparwasser, Tim; Figlin, Robert; Kim, Hyung L

    2014-04-15

    Inhibition of mTOR signaling enhances antitumor memory lymphocytes. However, pharmacologic mTOR inhibition also enhances regulatory T-cell (Treg) activity. To counter this effect, Treg control was added to mTOR inhibition in preclinical models. Tregs were controlled with CD4-depleting antibodies because CD4 depletion has high translational potential and already has a well-established safety profile in patients. The antitumor activity of the combination therapy was CD8 dependent and controlled growth of syngeneic tumors even when an adoptive immunotherapy was not used. Lymphocytes resulting from the combination therapy could be transferred into naïve mice to inhibit aggressive growth of lung metastases. The combination therapy enhanced CD8 memory formation as determined by memory markers and functional studies of immune recall. Removal of FoxP3-expressing T lymphocytes was the mechanism underlying immunologic memory formation following CD4 depletion. This was confirmed using transgenic DEREG (depletion of regulatory T cells) mice to specifically remove Foxp3(+) T cells. It was further confirmed with reciprocal studies where stimulation of immunologic memory because of CD4 depletion was completely neutralized by adoptively transferring tumor-specific Foxp3(+) T cells. Also contributing to tumor control, Tregs that eventually recovered following CD4 depletion were less immunosuppressive. These results provide a rationale for further study of mTOR inhibition and CD4 depletion in patients.

  3. Modulation of early human preadipocyte differentiation by glucocorticoids.

    PubMed

    Tomlinson, Julianna J; Boudreau, Adèle; Wu, Dongmei; Atlas, Ella; Haché, Robert J G

    2006-11-01

    Glucocorticoids provide an adipogenic stimulus that is most obvious in the truncal obesity of patients with Cushing's syndrome. Glucocorticoid treatment also strongly potentiates the differentiation of human preadipocytes in culture. However, the molecular basis of these stimulatory effects remains to be defined. In this study, we provide a detailed analysis of the specific contribution of glucocorticoid treatment to the differentiation of primary human preadipocytes cultured in chemically defined medium. Contrary to previous descriptions of glucocorticoids being required throughout the course of differentiation, our results show that glucocorticoid treatment is stimulatory only during the first 48 h of differentiation. Furthermore, stimulation by glucocorticoids and the peroxisome proliferator activator receptor-gamma agonist troglitazone is mediated sequentially. Several details of the early events in the differentiation of human preadipocytes and the contribution of steroid to these events differ from the responses observed previously in murine preadipocyte models. First, glucocorticoid treatment stimulated the early accumulation of CCAAT enhancer binding protein-beta (C/EBPbeta) in primary human preadipocytes. Second, induction of C/EBPalpha in primary human preadipocytes was noted within 4 h of adipogenic stimulus, whereas C/EBPalpha induction is not detected until 24-48 h in the murine 3T3 L1 preadipocyte model. Remarkably, by contrast to human primary preadipocytes, which do not undergo postconfluent mitosis, 3T3 L1 murine preadipocytes stimulated to differentiate under chemically defined conditions required glucocorticoids to survive the clonal expansion that precedes terminal differentiation, revealing a novel signal imparted by glucocorticoids in this immortalized murine cell system.

  4. Differential effects of acidosis, high potassium concentrations, and metabolic inhibition on noradrenaline release and its presynaptic muscarinic regulation.

    PubMed

    Haunstetter, Armin; Schulze Icking, Babette; Backs, Johannes; Krüger, Carsten; Haass, Markus

    2002-03-01

    It was the aim of the present study to characterize the effect of single components of ischaemia, such as inhibition of aerobic and anaerobic energy production by combined anoxic and glucose-free perfusion (metabolic inhibition), high extracellular potassium concentrations (hyperkalaemia), and acidosis, on (1). the stimulated release of noradrenaline from the in situ perfused guinea-pig heart and (2). its presynaptic modulation by the muscarinic agonist carbachol. The release of endogenous noradrenaline from efferent cardiac sympathetic nerve endings was induced by electrical stimulation of the left stellate ganglion (1 min, 5 V, 12 Hz) and quantified in the coronary venous effluent by high-performance liquid chromatography. Under control conditions, two consecutive electrical stimulations (S1, S2) elicited a similar noradrenaline overflow (S2/S1: 0.98 plus minus 0.05). After 10 min of global myocardial ischaemia overflow of endogenous noradrenaline was significantly reduced (S2/S1: 0.18 plus minus 0.03; P< 0.05). When studied separately, metabolic inhibition, hyperkalaemia (16 mM), and acidosis (pH 6.0) each markedly attenuated stimulated noradrenaline overflow (S2/S1: 0.65 plus minus 0.05, 0.43 plus minus 0.14, and 0.37 plus minus 0.09, respectively; P< 0.05). The muscarinic agonist carbachol (10 microM) inhibited stimulated noradrenaline release under normoxic conditions (S2/S1: 0.41 plus minus 0.07; P< 0.05). However, after 10 min of global myocardial ischaemia the inhibitory effect of carbachol on noradrenaline overflow was completely lost. Single components of ischaemia had a differential effect on presynaptic muscarinic modulation. Whereas hyperkalaemia (8-16 mM) did not affect muscarinic inhibition of noradrenaline release, carbachol lost its inhibitory effect during acidosis and metabolic inhibition. In conclusion, hyperkalaemia, metabolic inhibition, and severe acidosis each contribute to reduced overflow of noradrenaline after 10 min of myocardial

  5. Differential Space-Time Modulation for Wideband Wireless Networks

    DTIC Science & Technology

    2006-09-30

    modulation for wireless relay networks in Nakagami -m channels,” in Proceedings of the 2006 IEEE International Conference on Acoustic, Speech, and Signal... Nakagami -m fading channels," in Proceedings of the 6th IEEE International Workshop on Signal Processing Advances for Wireless Communications (SPAWC

  6. Thermally tuneable optical modulator adapted for differential signaling

    DOEpatents

    Zortman, William A.

    2016-01-12

    An apparatus for optical modulation is provided. The apparatus includes a modulator structure and a heater structure. The modulator structure comprises a ring or disk optical resonator having a closed curvilinear periphery and a pair of oppositely doped semiconductor regions within and/or adjacent to the optical resonator and conformed to modify the optical length of the optical resonator upon application of a bias voltage. The heater structure comprises a relatively resistive annulus of semiconductor material enclosed between an inner disk and an outer annulus of relatively conductive semiconductor material. The inner disk and the outer annulus are adapted as contact regions for a heater activation current. The heater structure is situated within the periphery of the optical resonator such that in operation, at least a portion of the resonator is heated by radial conductive heat flow from the heater structure. The apparatus further includes a substantially annular isolation region of dielectric or relatively resistive semiconductor material interposed between the heater structure and the modulator structure. The isolation region is effective to electrically isolate the bias voltage from the heater activation current.

  7. Phorbaketal A inhibits adipogenic differentiation through the suppression of PPARγ-mediated gene transcription by TAZ.

    PubMed

    Byun, Mi Ran; Lee, Cham Han; Hwang, Jun-Ha; Kim, A Rum; Moon, Sung Ah; Sung, Mi Kyung; Roh, Jung-Rae; Hwang, Eun Sook; Hong, Jeong-Ho

    2013-10-15

    Obesity causes several metabolic diseases, including diabetes. Adipogenic differentiation is an important event for fat formation in obesity. Natural compounds that inhibit adipogenic differentiation are frequently screened to develop therapeutic drugs for treating obesity. Here we investigated the effects of phorbaketal A, a natural marine compound, on adipogenic differentiation of mesenchymal stem cells. Phorbaketal A significantly inhibited adipogenic differentiation as indicated by less fat droplets and decreased expression of adipogenic marker genes. The expression of TAZ (transcriptional coactivator with PDZ-binding motif), an inhibitor of adipogenic differentiation, significantly increased during adipogenic differentiation in the presence of phorbaketal A. Phorbaketal A increased the interaction of TAZ and PPARγ to suppress PPARγ (peroxisome proliferator-activated receptor γ) target gene expression. TAZ-depleted cells showed higher adipogenic potential than that of control cells even in the presence of phorbaketal A. During cellular signaling induced by phorbaketal A, ERK (extracellular signal-regulated kinase) played an important role in adipogenic suppression; an inhibitor of ERK blocked phorbaketal A-induced adipogenic suppression. Thus, the results show that phorbaketal A inhibits adipocyte differentiation through TAZ.

  8. TNF receptor signaling inhibits cardiomyogenic differentiation of cardiac stem cells and promotes a neuroadrenergic-like fate.

    PubMed

    Hamid, Tariq; Xu, Yuanyuan; Ismahil, Mohamed Ameen; Li, Qianhong; Jones, Steven P; Bhatnagar, Aruni; Bolli, Roberto; Prabhu, Sumanth D

    2016-11-01

    Despite expansion of resident cardiac stem cells (CSCs; c-kit(+)Lin(-)) after myocardial infarction, endogenous repair processes are insufficient to prevent adverse cardiac remodeling and heart failure (HF). This suggests that the microenvironment in post-ischemic and failing hearts compromises CSC regenerative potential. Inflammatory cytokines, such as tumor necrosis factor-α (TNF), are increased after infarction and in HF; whether they modulate CSC function is unknown. As the effects of TNF are specific to its two receptors (TNFRs), we tested the hypothesis that TNF differentially modulates CSC function in a TNFR-specific manner. CSCs were isolated from wild-type (WT), TNFR1-/-, and TNFR2-/- adult mouse hearts, expanded and evaluated for cell competence and differentiation in vitro in the absence and presence of TNF. Our results indicate that TNF signaling in murine CSCs is constitutively related primarily to TNFR1, with TNFR2 inducible after stress. TNFR1 signaling modestly diminished CSC proliferation, but, along with TNFR2, augmented CSC resistance to oxidant stress. Deficiency of either TNFR1 or TNFR2 did not impact CSC telomerase activity. Importantly, TNF, primarily via TNFR1, inhibited cardiomyogenic commitment during CSC differentiation, and instead promoted smooth muscle and endothelial fates. Moreover, TNF, via both TNFR1 and TNFR2, channeled an alternate CSC neuroadrenergic-like fate (capable of catecholamine synthesis) during differentiation. Our results suggest that elevated TNF in the heart restrains cardiomyocyte differentiation of resident CSCs and may enhance adrenergic activation, both effects that would reduce the effectiveness of endogenous cardiac repair and the response to exogenous stem cell therapy, while promoting adverse cardiac remodeling.

  9. A novel EID family member, EID-3, inhibits differentiation and forms a homodimer or heterodimer with EID-2

    SciTech Connect

    Sasajima, Yuka; Tanaka, Hiroyuki; Miyake, Satoshi; Yuasa, Yasuhito . E-mail: yuasa.monc@tmd.ac.jp

    2005-08-05

    The EID family members, i.e., E1A-like inhibitor of differentiation-1 (EID-1) and EID-1-like inhibitor of differentiation-2 (EID-2), were identified as negative regulators of cellular differentiation. EID-1 seems to inhibit differentiation by blocking histone acetyltransferase activity and EID-2 possibly inhibits differentiation through binding to class I histone deacetylases (HDACs). Here, we report a novel inhibitor of differentiation exhibiting homology with EID-2 termed EID-3 (EID-2-like inhibitor of differentiation-3). Like EID-2, EID-3 inhibited MyoD- and GR{alpha}-dependent transcription and blocked muscle differentiation in cultured cells by binding to class I HDACs. Unlike that of EID-2, the C-terminus, but not the N-terminus, of EID-3 was required for nuclear localization. EID-3 formed a homodimer or heterodimer with EID-2. These results suggest that EID-3 inhibits differentiation by blocking transcription as a complex in cells.

  10. Quantitative Identification of Compound‐Dependent On‐Modules and Differential Allosteric Modules From Homologous Ischemic Networks

    PubMed Central

    Li, B; Liu, J; Zhang, YY; Wang, PQ; Yu, YN; Kang, RX; Wu, HL; Zhang, XX; Wang, YY

    2016-01-01

    Module‐based methods have made much progress in deconstructing biological networks. However, it is a great challenge to quantitatively compare the topological structural variations of modules (allosteric modules [AMs]) under different situations. A total of 23, 42, and 15 coexpression modules were identified in baicalin (BA), jasminoidin (JA), and ursodeoxycholic acid (UA) in a global anti‐ischemic mice network, respectively. Then, we integrated the methods of module‐based consensus ratio (MCR) and modified Zsummary module statistic to validate 12 BA, 22 JA, and 8 UA on‐modules based on comparing with vehicle. The MCRs for pairwise comparisons were 1.55% (BA vs. JA), 1.45% (BA vs. UA), and 1.27% (JA vs. UA), respectively. Five conserved allosteric modules (CAMs) and 17 unique allosteric modules (UAMs) were identified among these groups. In conclusion, module‐centric analysis may provide us a unique approach to understand multiple pharmacological mechanisms associated with differential phenotypes in the era of modular pharmacology. PMID:27758049

  11. Attentional modulation of medial olivocochlear inhibition: evidence for immaturity in children.

    PubMed

    Mishra, Srikanta K

    2014-12-01

    Efferent feedback shapes afferent auditory processing. Auditory attention has been shown to modulate medial olivocochlear (MOC) efferent activity in human adults. Since auditory attention continues to develop throughout childhood, the present study explored whether attentional control of medial-efferent inhibition in 5-10 year-old children is adult-like. MOC inhibition was measured in adults (n = 14) and children (n = 12) during no-task (contralateral broadband noise), passive (contralateral noise with tone-pips) and active listening conditions (attended tone-pips embedded in contralateral broadband noise). A stronger MOC inhibition was observed when measured during the active listening condition for adults which is consistent with past work. However, the effect of auditory attention on MOC inhibition in children was not robust and was significantly lower compared to that observed for adults. These findings suggest the potential immaturity of the attentional mediation of MOC inhibition in tested children.

  12. Cue and Target Processing Modulate the Onset of Inhibition of Return

    ERIC Educational Resources Information Center

    Gabay, Shai; Chica, Ana B.; Charras, Pom; Funes, Maria J.; Henik, Avishai

    2012-01-01

    Inhibition of return (IOR) is modulated by task set and appears later in discrimination tasks than in detection tasks. Several hypotheses have been suggested to account for this difference. We tested three of these hypotheses in two experiments by examining the influence of cue and target level of processing on the onset of IOR. In the first…

  13. Effect of low frequency magnetic fields on melanoma: tumor inhibition and immune modulation

    PubMed Central

    2013-01-01

    Background We previously found that the low frequency magnetic fields (LF-MF) inhibited gastric and lung cancer cell growth. We suppose that exposure to LF-MF may modulate immune function so as to inhibit tumor. We here investigated whether LF-MF can inhibit the proliferation and metastasis of melanoma and influence immune function. Methods The effect of MF on the proliferation, cell cycle and ultrastracture of B16-F10 in vitro was detected by cell counting Kit-8 assay, flow cytometry, and transmission electron microscopy. Lung metastasis mice were prepared by injection of 2 × 105 B16-F10 melanoma cells into the tail vein in C57BL/6 mice. The mice were then exposed to an LF-MF (0.4 T, 7.5 Hz) for 43 days. Survival rate, tumor markers and the innate and adaptive immune parameters were measured. Results The growth of B16-F10 cells was inhibited after exposure to the LF-MF. The inhibition was related to induction of cell cycle arrest and decomposition of chromatins. Moreover, the LF-MF prolonged the mouse survival rate and inhibited the proliferation of B16-F10 in melanoma metastasis mice model. Furthermore, the LF-MF modulated the immune response via regulation of immune cells and cytokine production. In addition, the number of Treg cells was decreased in mice with the LF-MF exposure, while the numbers of T cells as well as dendritic cells were significantly increased. Conclusion LF-MF inhibited the growth and metastasis of melanoma cancer cells and improved immune function of tumor-bearing mice. This suggests that the inhibition may be attributed to modulation of LF-MF on immune function and LF-MF may be a potential therapy for treatment of melanoma. PMID:24314291

  14. Reciprocal interactions of Fgf10/Fgfr2b modulate the mouse tongue epithelial differentiation.

    PubMed

    Sohn, Wern-Joo; Jung, Hye-In; Choi, Min-A; Han, Jin-Hyun; Gwon, Gi-Jeong; Yamamoto, Hitoshi; Lee, Sanggyu; Ryoo, Zae Young; Park, Eui-Kyun; Shin, Hong-In; Jung, Han-Sung; Kim, Jae-Young

    2011-08-01

    The molecular mechanisms for epithelial differentiation have been studied by observing skin development in embryogenesis, but the early signaling modulations involved in tongue epithelial differentiation are not completely understood. Based on the gene expression patterns of the Fgf signaling molecules and previous results from Fgf10 and Fgfr2b knockout mice, it was hypothesized that there would be fundamental signaling interactions through the epithelial Fgfr2b and its mesenchymal ligand Fgf10 to regulate tongue epithelium differentiation. To elucidate these reciprocal interactions in tongue epithelial differentiation, this study employed an in vitro tongue organ culture system with antisense-oligodeoxynucleotides (AS-ODNs) and recombinant protein-soaked bead implantation for the loss-of-function and gain-of-function studies. Functional analysis of Fgf signaling revealed precise reciprocal interactions, which showed that mesenchymal Fgf10 rather than Fgf7 modulates tongue epithelial differentiation via Fgfr2b in a temporal- and spatial-specific manner.

  15. TGFβ2 Differentially Modulates Smooth Muscle Cell Proliferation and Migration in Electrospun Gelatin-Fibrinogen constructs

    PubMed Central

    Ardila, D. C.; Tamimi, E.; Danford, F.L.; Haskett, D. G.; Kellar, R. S.; Doetschman, T.; Vande Geest, J.P.

    2014-01-01

    A main goal of tissue engineering is the development of scaffolds that replace, restore and improve injured tissue. These scaffolds have to mimic natural tissue, constituted by an extracellular matrix (ECM) support, cells attached to the ECM, and signaling molecules such as growth factors that regulate cell function. In this study we created electrospun flat sheet scaffolds using different compositions of gelatin and fibrinogen. Smooth muscle cells (SMCs) were seeded on the scaffolds, and proliferation and infiltration were evaluated. Additionally, different concentrations of Transforming Growth Factor-beta2 (TGFβ2) were added to the medium with the aim of elucidating its effect on cell proliferation, migration and collagen production. Our results demostrated that a scafold with a composition of 80% gelatin-20% fibrinogen is suitable for tissue engineering applications since it promotes cell growth and migration. The addition of TGFβ2 at low concentrations (≤1ng/ml) to the culture medium resulted in an increase in SMC proliferation and scaffold infiltration, and in the reduction of collagen production. In contrast, TGFβ2 at concentrations >1ng/ml inhibited cell proliferation and migration while stimulating collagen production. According to our results TGFβ2 concentration has a differential effect on SMC function and thus can be used as a biochemical modulator that can be beneficial for tissue engineering applications. PMID:25453947

  16. PAX3 inhibits β-Tubulin-III expression and neuronal differentiation of neural stem cell.

    PubMed

    Cao, Sixian; Du, Jinfeng; Lv, Yan; Lin, Hengrong; Mao, Zuming; Xu, Man; Liu, Mei; Liu, Yan

    2017-02-20

    PAX3 functions at the nodal point in neural stem cell maintenance and differentiation. Using bioinformatics methods, we identified PAX3 as a potential regulator of β-Tubulin-III (TUBB3) gene transcription, and the results indicated that PAX3 might be involved in neural stem cell (NSC) differentiation by orchestrating the expression of cytoskeletal proteins. In the present study, we reported that PAX3 could inhibit the differentiation of NSCs and the expression of TUBB3. Further, using luciferase and electrophoretic mobility shift assays, we demonstrated that PAX3 could bind to the promoter region of TUBB3 and inhibit TUBB3 transcription. Finally, we confirmed that PAX3 could bind to the promoter region of endogenous TUBB3 in the native chromatin of NSCs. These findings indicated that PAX3 is a pivotal factor targeting various molecules during differentiation of NSCs in vitro.

  17. WNK1 is involved in Nogo66 inhibition of OPC differentiation.

    PubMed

    Zhang, Zhao-Huan; Li, Jiao-Jiao; Wang, Qing-Jin; Zhao, Wei-Qian; Hong, Jiang; Lou, Shu-jie; Xu, Xiao-Hui

    2015-03-01

    LINGO-1 is a transmembrane receptor expressed primarily in the central nervous system (CNS) and plays an important role in myelination. Recent studies have indicated that it is also involved in oligodendrocyte precursor cell (OPC) survival and differentiation; however, the downstream signaling pathway underlying OPC development is unknown. In our previous study, we found that LINGO-1 is associated with WNK1 in mediating Nogo-induced neurite extension inhibition by RhoA activation. In an effort to identify the role of LINGO-1-WNK1 in OPCs, we first confirmed that WNK1 is also expressed in OPCs and co-localized with LINGO-1, which suppresses WNK1 expression by RNA interference-attenuated Nogo66-induced inhibition of OPC differentiation. Furthermore, we mapped the WNK1 kinase domain using several fragmented peptides to identify the key region of interaction with LINGO-1. We found that a sequence corresponding to the D6 peptide is necessary for the interaction. Finally, we found that using the TAT-D6 peptide to introduce D6 peptide into primary cultured OPC inhibits the association between LINGO-1 and WNK1 and significantly attenuates Nogo66-induced inhibition of OPC differentiation. Taken together, our results show that WNK1, via a specific region on WNK1 kinase domain, interacts with LINGO-1, thus mediating Nogo66-inhibited OPC differentiation.

  18. Monocytic Differentiation Inhibits Infection and Granulocytic Differentiation Potentiates Infection by the Agent of Human Granulocytic Ehrlichiosis

    PubMed Central

    Klein, Marina B.; Hayes, Stanley F.; Goodman, Jesse L.

    1998-01-01

    Human granulocytic ehrlichiosis (HGE) is an emerging tick-borne infection with a specific tropism for granulocytes. We previously isolated and cultivated the HGE agent in the promyelocytic leukemia cell line HL-60 and have also demonstrated the susceptibility of both granulocytic and monocytic human marrow progenitors. Circulating monocytes have not been observed to be infected, suggesting that cell susceptibility may be differentiation specific. To evaluate this hypothesis, HL-60 cells were differentiated towards granulocytes (with dimethyl sulfoxide or all-trans retinoic acid) or toward monocytes-macrophages (with 12-O-tetradecanoylphorbol-13-acetate [TPA], gamma interferon, or 1,25-dihydroxyvitamin D3) and then challenged with HGE. HGE binding, internalization, and proliferation were compared in differentiated and untreated control HL-60 cells by immunofluorescence, electron microscopy, and Giemsa staining. Granulocytic differentiation resulted in a doubling of HGE binding and enhanced infection consistent with the agent’s clinical tropism for neutrophils. Granulocytic cells were unable to kill internalized ehrlichiae even after activation induced by N-formyl-Met-Leu-Phe alone or together with tumor necrosis factor alpha. In contrast, monocyte-macrophage differentiation with TPA resulted in complete resistance to infection through at least two distinct mechanisms: (i) reduction in binding and uptake and (ii) killing of any internalized organisms. Diminished binding in TPA-treated cells correlated with their reduced expression of sialyl Lewis x (CD15s), a putative cellular receptor component for HGE. The degree of monocytic differentiation and activation induced (i.e., TPA > gamma interferon > vitamin D3) correlated with resistance to HGE. Thus, HL-60 cells exhibit a striking differentiation-specific susceptibility to HGE. Differentiation-induced changes in bacterial adhesion and killing capacity underlie the tropism of HGE for granulocytic HL-60 cells and

  19. Hormonal induction and antihormonal inhibition of tracheary element differentiation in Zinnia cell cultures

    NASA Technical Reports Server (NTRS)

    Church, D. L.; Galston, A. W.

    1988-01-01

    Mechanically isolated mesophyll cells of Zinnia elegans L. cv Envy differentiate to tracheary elements when cultured in inductive medium containing sufficient auxin and cytokinin. Tracheary element differentiation was induced by the three auxins (alpha-naphthaleneacetic acid, indole-3-acetic acid, and 2,4-dichlorophenoxyacetic acid) and four cytokinins (6-benzyladenine, kinetin, 2-isopentenyladenine and zeatin) tested. Tracheary element formation is inhibited or delayed if the inductive medium is supplemented with an anticytokinin, antiauxin, or inhibitor of auxin transport.

  20. Pitavastatin Differentially Modulates MicroRNA-Associated Cholesterol Transport Proteins in Macrophages

    PubMed Central

    Moran, George; Sun, Tao; Gotto, Antonio M.; Hajjar, David P.

    2016-01-01

    There is emerging evidence identifying microRNAs (miRNAs) as mediators of statin-induced cholesterol efflux, notably through the ATP-binding cassette transporter A1 (ABCA1) in macrophages. The objective of this study was to assess the impact of an HMG-CoA reductase inhibitor, pitavastatin, on macrophage miRNAs in the presence and absence of oxidized-LDL, a hallmark of a pro-atherogenic milieu. Treatment of human THP-1 cells with pitavastatin prevented the oxLDL-mediated suppression of miR-33a, -33b and -758 mRNA in these cells, an effect which was not uniquely attributable to induction of SREBP2. Induction of ABCA1 mRNA and protein by oxLDL was inhibited (30%) by pitavastatin, while oxLDL or pitavastatin alone significantly induced and repressed ABCA1 expression, respectively. These findings are consistent with previous reports in macrophages. miRNA profiling was also performed using a miRNA array. We identified specific miRNAs which were up-regulated (122) and down-regulated (107) in THP-1 cells treated with oxLDL plus pitavastatin versus oxLDL alone, indicating distinct regulatory networks in these cells. Moreover, several of the differentially expressed miRNAs identified are functionally associated with cholesterol trafficking (six miRNAs in cells treated with oxLDL versus oxLDL plus pitavastatin). Our findings indicate that pitavastatin can differentially modulate miRNA in the presence of oxLDL; and, our results provide evidence that the net effect on cholesterol homeostasis is mediated by a network of miRNAs. PMID:27415822

  1. RANK ligand signaling modulates the matrix metalloproteinase-9 gene expression during osteoclast differentiation

    SciTech Connect

    Sundaram, Kumaran; Nishimura, Riko; Senn, Joseph; Youssef, Rimon F.; London, Steven D.; Reddy, Sakamuri V. . E-mail: reddysv@musc.edu

    2007-01-01

    Osteoclast differentiation is tightly regulated by receptor activator of NF-{kappa}B ligand (RANKL) signaling. Matrix metalloproteinase-9 (MMP-9), a type IV collagenase is highly expressed in osteoclast cells and plays an important role in degradation of extracellular matrix; however, the molecular mechanisms that regulate MMP-9 gene expression are unknown. In this study, we demonstrate that RANKL signaling induces MMP-9 gene expression in osteoclast precursor cells. We further show that RANKL regulates MMP-9 gene expression through TRAF6 but not TRAF2. Interestingly, blockade of p38 MAPK activity by pharmacological inhibitor, SB203580 increases MMP-9 activity whereas ERK1/2 inhibitor, PD98059 decreases RANKL induced MMP-9 activity in RAW264.7 cells. These data suggest that RANKL differentially regulates MMP-9 expression through p38 and ERK signaling pathways during osteoclast differentiation. Transient expression of MMP-9 gene (+ 1 to - 1174 bp relative to ATG start codon) promoter-luciferase reporter plasmids in RAW264.7 cells and RANKL stimulation showed significant increase (20-fold) of MMP-9 gene promoter activity; however, there is no significant change with respect to + 1 bp to - 446 bp promoter region and empty vector transfected cells. These results indicated that MMP-9 promoter sequence from - 446 bp to - 1174 bp relative to start codon is responsive to RANKL stimulation. Sequence analysis of the mouse MMP-9 gene promoter region further identified the presence of binding motif (- 1123 bp to - 1153 bp) for the nuclear factor of activated T cells 1 (NFATc1) transcription factor. Inhibition of NFATc1 using siRNA and VIVIT peptide inhibitor significantly decreased RANKL stimulation of MMP-9 activity. We further confirm by oligonucleotide pull-down assay that RANKL stimuli enhanced NFATc1 binding to MMP-9 gene promoter element. In addition, over-expression of constitutively active NFAT in RAW264.7 cells markedly increased (5-fold) MMP-9 gene promoter activity

  2. Nutlin-3 down-regulates retinoblastoma protein expression and inhibits muscle cell differentiation

    SciTech Connect

    Walsh, Erica M.; Niu, MengMeng; Bergholz, Johann; Jim Xiao, Zhi-Xiong

    2015-05-29

    The p53 tumor suppressor gene plays a critical role in regulation of proliferation, cell death and differentiation. The MDM2 oncoprotein is a major negative regulator for p53 by binding to and targeting p53 for proteasome-mediated degradation. The small molecule inhibitor, nutlin-3, disrupts MDM2-p53 interaction resulting in stabilization and activation of p53 protein. We have previously shown that nutlin-3 activates p53, leading to MDM2 accumulation as concomitant of reduced retinoblastoma (Rb) protein stability. It is well known that Rb is important in muscle development and myoblast differentiation and that rhabdomyosarcoma (RMS), or cancer of the skeletal muscle, typically harbors MDM2 amplification. In this study, we show that nutlin-3 inhibited myoblast proliferation and effectively prevented myoblast differentiation, as evidenced by lack of expression of muscle differentiation markers including myogenin and myosin heavy chain (MyHC), as well as a failure to form multinucleated myotubes, which were associated with dramatic increases in MDM2 expression and decrease in Rb protein levels. These results indicate that nutlin-3 can effectively inhibit muscle cell differentiation. - Highlights: • Nutlin-3 inhibits myoblast proliferation and prevents differentiation into myotubes. • Nutlin-3 increases MDM2 expression and down-regulates Rb protein levels. • This study has implication in nutlin-3 treatment of rhabdomyosarcomas.

  3. Advanced oxidation protein products inhibit differentiation and activate inflammation in 3T3-L1 preadipocytes.

    PubMed

    Zhou, Qiu Gen; Peng, Xin; Hu, Li Li; Xie, Di; Zhou, Min; Hou, Fan Fan

    2010-10-01

    Accumulation of advanced oxidation protein products (AOPPs) is prevalent in metabolic syndromes, a condition with impaired preadipocytes differentiation. In the present study, we tested the hypothesis that AOPPs disturb preadipocyte differentiation. Exposure of 3T3-L1 preadipocytes to increased levels of AOPPs inhibited accumulation of intracellular triglyceride and decreased the expression of the essential markers of matured adipocytes, such as adipocyte fatty-acid-binding protein (aP2), CAAT/enhancer-binding protein (C/EBP)-alpha, and peroxisome proliferator-activated receptor (PPAR)-gamma, in response to standard adipogenic induction. Inhibitory effects of AOPPs on preadipocytes differentiation was time sensitive, which occurred at the early stage of differentiation. In the presence of AOPPs, induction of preadipocytes differentiation resulted in upregulated expression of C/EBP homologous protein (CHOP) and CUG-Triplet repeat-binding protein (CUGBP), two important inhibitors of preadipocytes differentiation. In addition, treatment with AOPPs increased abundance of C/EBP-beta-liver enriched inhibitory protein (C/EBP-beta-LIP), a truncated C/EBP-beta isoform without adipogenic activity. Moreover, AOPPs-treated preadipocytes expressed a macrophage marker F4/80 and overexpressed tumor necrosis factor-alpha and interleukin-6 via nuclear factor-kappaB (NF-kappaB)-dependent pathway. However, blocking inflammation with NF-kappaB inhibitor failed to improve AOPPs-induced inhibition of preadipocytes differentiation. These data suggest that accumulation of AOPPs may inhibit differentiation of preadipocytes and activate inflammation in these cells. This information might have implication for understanding the impairment of preadipocytes differentiation and fat inflammation seen in metabolic syndrome.

  4. Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings 1

    PubMed Central

    Creelman, Robert A.; Mason, Hugh S.; Bensen, Robert J.; Boyer, John S.; Mullet, John E.

    1990-01-01

    Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite. Images Figure 6 Figure 7 PMID:16667248

  5. Inhibition of actin polymerization decreases osteogeneic differentiation of mesenchymal stem cells through p38 MAPK pathway

    PubMed Central

    2013-01-01

    Background Mesenchymal Stem Cells (MSC) are important candidates for therapeutic applications due to their ex vivo proliferation and differentiation capacity. MSC differentiation is controlled by both intrinsic and extrinsic factors and actin cytoskeleton plays a major role in the event. In the current study, we tried to understand the initial molecular mechanisms and pathways that regulate the differentiation of MSC into osteocytes or adipocytes. Results We observed that actin modification was important during differentiation and differentially regulated during adipogenesis and osteogenesis. Initial disruption of actin polymerization reduced further differentiation of MSC into osteocytes and osteogenic differentiation was accompanied by increase in ERK1/2 and p38 MAPK phosphorylation. However, only p38 MAPK phosphorylation was down regulated upon inhibition of actin polymerization which as accompanied by decreased CD49E expression. Conclusion Taken together, our results show that actin modification is a pre-requisite for MSC differentiation into osteocytes and adipocytes and osteogenic differentiation is regulated through p38 MAPK phosphorylation. Thus by modifying their cytoskeleton the differentiation potential of MSC could be controlled which might have important implications for tissue repair and regeneration. PMID:24070328

  6. Metformin inhibits angiotensin II-induced differentiation of cardiac fibroblasts into myofibroblasts.

    PubMed

    Bai, Jian; Zhang, Na; Hua, Ying; Wang, Bingjian; Ling, Lin; Ferro, Albert; Xu, Biao

    2013-01-01

    Differentiation of cardiac fibroblasts into myofibroblasts is a critical event in the progression of cardiac fibrosis that leads to pathological cardiac remodeling. Metformin, an antidiabetic agent, exhibits a number of cardioprotective properties. However, much less is known regarding the effect of metformin on cardiac fibroblast differentiation. Thus, in the present study, we examined the effect of metformin on angiotensin (Ang) II-induced differentiation of cardiac fibroblasts into myofibroblasts and its underlying mechanism. Adult rat cardiac fibroblasts were stimulated with Ang II (100 nM) in the presence or absence of metformin (10-200 µM). Ang II stimulation induced the differentiation of cardiac fibroblasts into myofibroblasts, as indicated by increased expression of α-smooth muscle actin (α-SMA) and collagen types I and III, and this effect of Ang II was inhibited by pretreatment of cardiac fibroblasts with metformin. Metformin also decreased Ang II-induced reactive oxygen species (ROS) generation in cardiac fibroblasts via inhibiting the activation of the PKC-NADPH oxidase pathway. Further experiments using PKC inhibitor calphostin C and NADPH oxidase inhibitor apocynin confirmed that inhibition of the PKC-NADPH oxidase pathway markedly attenuated Ang II-induced ROS generation and myofibroblast differentiation. These data indicate that metformin inhibits Ang II-induced myofibroblast differentiation by suppressing ROS generation via the inhibition of the PKC-NADPH oxidase pathway in adult rat cardiac fibroblasts. Our results provide new mechanistic insights regarding the cardioprotective effects of metformin and provide an efficient therapeutic strategy to attenuate cardiac fibrosis.

  7. Gut vagal afferents differentially modulate innate anxiety and learned fear.

    PubMed

    Klarer, Melanie; Arnold, Myrtha; Günther, Lydia; Winter, Christine; Langhans, Wolfgang; Meyer, Urs

    2014-05-21

    Vagal afferents are an important neuronal component of the gut-brain axis allowing bottom-up information flow from the viscera to the CNS. In addition to its role in ingestive behavior, vagal afferent signaling has been implicated modulating mood and affect, including distinct forms of anxiety and fear. Here, we used a rat model of subdiaphragmatic vagal deafferentation (SDA), the most complete and selective vagal deafferentation method existing to date, to study the consequences of complete disconnection of abdominal vagal afferents on innate anxiety, conditioned fear, and neurochemical parameters in the limbic system. We found that compared with Sham controls, SDA rats consistently displayed reduced innate anxiety-like behavior in three procedures commonly used in preclinical rodent models of anxiety, namely the elevated plus maze test, open field test, and food neophobia test. On the other hand, SDA rats exhibited increased expression of auditory-cued fear conditioning, which specifically emerged as attenuated extinction of conditioned fear during the tone re-exposure test. The behavioral manifestations in SDA rats were associated with region-dependent changes in noradrenaline and GABA levels in key areas of the limbic system, but not with functional alterations in the hypothalamus-pituitary-adrenal grand stress. Our study demonstrates that innate anxiety and learned fear are both subjected to visceral modulation through abdominal vagal afferents, possibly via changing limbic neurotransmitter systems. These data add further weight to theories emphasizing an important role of afferent visceral signals in the regulation of emotional behavior.

  8. Vinculin promotes nuclear localization of TAZ to inhibit ECM stiffness-dependent differentiation into adipocytes.

    PubMed

    Kuroda, Mito; Wada, Hiroki; Kimura, Yasuhisa; Ueda, Kazumitsu; Kioka, Noriyuki

    2017-03-01

    Extracellular matrix (ECM) stiffness regulates the lineage commitment of mesenchymal stem cells (MSCs). Although cells sense ECM stiffness through focal adhesions, how cells sense ECM stiffness and regulate ECM stiffness-dependent differentiation remains largely unclear. In this study, we show that the cytoskeletal focal adhesion protein vinculin plays a critical role in the ECM stiffness-dependent adipocyte differentiation of MSCs. ST2 mouse MSCs differentiate into adipocytes and osteoblasts in an ECM stiffness-dependent manner. We find that a rigid ECM increases the amount of cytoskeleton-associated vinculin and promotes the nuclear localization and activity of the transcriptional coactivator paralogs Yes-associated protein (YAP, also known as YAP1) and transcriptional coactivator with a PDZ-binding motif (TAZ, also known as WWTR1) (hereafter YAP/TAZ). Vinculin is necessary for enhanced nuclear localization and activity of YAP/TAZ on the rigid ECM but it does not affect the phosphorylation of the YAP/TAZ kinase LATS1. Furthermore, vinculin depletion promotes differentiation into adipocytes on rigid ECM, while it inhibits differentiation into osteoblasts. Finally, TAZ knockdown was less effective at promoting adipocyte differentiation in vinculin-depleted cells than in control cells. These results suggest that vinculin promotes the nuclear localization of transcription factor TAZ to inhibit the adipocyte differentiation on rigid ECM.

  9. Aloe-emodin inhibits adipocyte differentiation and maturation during in vitro human mesenchymal stem cell adipogenesis.

    PubMed

    Subash-Babu, Pandurangan; Alshatwi, Ali A

    2012-08-01

    In this study, we examined the effects of Aloe-emodin (AE) on the inhibition of adipocyte differentiation during 3-isobutyl-1-methylxanthine (IBMX)-induced adipocyte differentiation in human mesenchymal stem cells (hMSCs). AE treatment (5, 10, and 20 µM) of preadipocyte cells resulted in a significant (p < 0.05) decrease in glycerol phosphate dehydrogenase and triglyceride levels as well as an increase in lactate dehydrogenase activity and attenuated lipid accumulation compared with untreated differentiated adipocytes. Using quantitative reverse transcription polymerase chain reaction, we studied the mRNA expression levels of resistin, adiponectin, aP(2), lipoprotein lipase, PPARγ, and tumor necrosis factor-α in hMSCs undergoing adipocyte differentiation; treatment with AE decreased the expression of these adipogenic genes and decreased adipocyte differentiation. In addition, AE suppresses the differentiation of hMSCs into adipocytes by downregulating PPARγ and C/EBPα expressions. AE significantly inhibited hMSCs proliferation and preadipocyte differentiation within the first 2 days of treatment, indicating that the antiadipogenic effect.

  10. The Selective Estrogen Receptor Modulator Raloxifene Inhibits Neutrophil Extracellular Trap Formation

    PubMed Central

    Flores, Roxana; Döhrmann, Simon; Schaal, Christina; Hakkim, Abdul; Nizet, Victor; Corriden, Ross

    2016-01-01

    Raloxifene is a selective estrogen receptor modulator typically prescribed for the prevention/treatment of osteoporosis in postmenopausal women. Although raloxifene is known to have anti-inflammatory properties, its effects on human neutrophils, the primary phagocytic leukocytes of the immune system, remain poorly understood. Here, through a screen of pharmacologically active small molecules, we find that raloxifene prevents neutrophil cell death in response to the classical activator phorbol 12-myristate 13-acetate (PMA), a compound known to induce formation of DNA-based neutrophil extracellular traps (NETs). Inhibition of PMA-induced NET production by raloxifene was confirmed using quantitative and imaging-based assays. Human neutrophils from both male and female donors express the nuclear estrogen receptors ERα and ERβ, known targets of raloxifene. Similar to raloxifene, selective antagonists of these receptors inhibit PMA-induced NET production. Furthermore, raloxifene inhibited PMA-induced ERK phosphorylation, but not reactive oxygen species production, pathways known to be key modulators of NET production. Finally, we found that raloxifene inhibited PMA-induced, NET-based killing of the leading human bacterial pathogen, methicillin-resistant Staphylococcus aureus. Our results reveal that raloxifene is a potent modulator of neutrophil function and NET production. PMID:28003814

  11. Vitisin A inhibits adipocyte differentiation through cell cycle arrest in 3T3-L1 cells

    SciTech Connect

    Kim, Soon-hee; Park, Hee-Sook; Lee, Myoung-su; Cho, Yong-Jin; Kim, Young-Sup; Hwang, Jin-Taek; Sung, Mi Jeong; Kim, Myung Sunny; Kwon, Dae Young

    2008-07-18

    Inhibition of adipocyte differentiation is one approach among the anti-obesity strategies. This study demonstrates that vitisin A, a resveratrol tetramer, inhibits adipocyte differentiation most effectively of 18 stilbenes tested. Fat accumulation and PPAR{gamma} expression were decreased by vitisin A in a dose-dependent manner. Vitisin A significantly inhibited preadipocyte proliferation and consequent differentiation within the first 2 days of treatment, indicating that the anti-adipogenic effect of vitisin A was derived from anti-proliferation. Based on cell cycle analysis, vitisin A blocked the cell cycle at the G1-S phase transition, causing cells to remain in the preadipocyte state. Vitisin A increased p21 expression, while the Rb phosphorylation level was reduced. Therefore, vitisin A seems to induce G1 arrest through p21- and consequent Rb-dependent suppression of transcription. On the other hand, ERK and Akt signaling pathways were not involved in the anti-mitotic regulation by vitisin A. Taken together, these results suggest that vitisin A inhibits adipocyte differentiation through preadipocyte cell cycle arrest.

  12. Differential Effects of Social and Non-Social Reward on Response Inhibition in Children and Adolescents

    ERIC Educational Resources Information Center

    Kohls, Gregor; Peltzer, Judith; Herpertz-Dahlmann, Beate; Konrad, Kerstin

    2009-01-01

    An important issue in the field of clinical and developmental psychopathology is whether cognitive control processes, such as response inhibition, can be specifically enhanced by motivation. To determine whether non-social (i.e. monetary) and social (i.e. positive facial expressions) rewards are able to differentially improve response inhibition…

  13. Inhibition of Th17 Cell Differentiation as a Treatment for Multiple Sclerosis

    DTIC Science & Technology

    2012-10-01

    2012 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Inhibition of Th17 Cell Differentiation as a Treatment for Multiple Sclerosis 5b. GRANT NUMBER...in a variety of disease models; they act as tumor suppressors cancer and influence inflammation. One microRNA, miR-326, affects development of Th17

  14. The Impact of Mitochondrial Complex Inhibition on mESC Differentiation

    EPA Science Inventory

    The Impact of Mitochondrial Complex Inhibition on mESC Differentiation JE Royland, SH Warren, S Jeffay, MR Hoopes, HP Nichols, ES Hunter U.S. Environmental Protection Agency, Integrated Systems Toxicology Division, Research Triangle Park, NC The importance of mitochondrial funct...

  15. VANADYL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF ENOS

    EPA Science Inventory

    VANADYL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF eNOS.

    Zhuowei Li, Jacqueline D. Carter, Lisa A. Dailey, Joleen Soukup, Yuh-Chin T. Huang. CEMALB, University of North Carolina and NHEERL, US EPA, Chapel Hill, North Ca...

  16. VANADL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF ENOS

    EPA Science Inventory

    VANADYL SULFATE INHIBITS NO PRODUCTION BY DIFFERENTIALLY REGULATING SERINE/THREONINE PHOSPHORYLATION OF eNOS. Zhuowei Li, Jacqueline D. Carter, Lisa A. Dailey, Joleen Soukup, Yuh-Chin T. Huang. CEMALB, University of North Carolina and ORD, US EPA, Chapel Hill, North Carolina
    V...

  17. Inhibition of TROY Promotes OPC Differentiation and Increases Therapeutic Efficacy of OPC Graft for Spinal Cord Injury

    PubMed Central

    Sun, Liang; Liu, Shengliang; Sun, Qi; Li, Zhuying; Xu, Fengyan; Hou, Chunmei; Harada, Toshihide; Chu, Ming; Xu, Kun; Feng, Xiaoling

    2014-01-01

    Endogenous or graft-derived oligodendrocytes promote myelination and aid in the recovery from central nervous system (CNS) injury. Regulatory mechanisms underlying neural myelination and remyelination in response to injury, including spinal cord injury (SCI), are unclear. In the present study, we demonstrated that TROY serves as an important negative regulator of oligodendrocyte development and that TROY inhibition augments the repair potential of oligodendrocyte precursor cell (OPC) graft for SCI. TROY expression was detected by reverse transcriptase–polymerase chain reaction in OPCs as well as in differentiated premature and mature oligodendrocytes of postnatal mice. Pharmacological inhibition or RNAi-induced knockdown of TROY promotes OPC differentiation, whereas overexpression of TROY dampens oligodendrocyte maturation. Further, treatment of cocultures of DRG neurons and OPCs with TROY inhibitors promotes myelination and myelin-sheath-like structures. Mechanically, protein kinase C (PKC) signaling is involved in the regulation of the inhibitory effects of TROY. Moreover, in situ transplantation of OPCs with TROY knockdown leads to notable remyelination and neurological recovery in rats with SCI. Our results indicate that TROY negatively modulates remyelination in the CNS, and thus may be a suitable target for improving the therapeutic efficacy of cell transplantation for CNS injury. PMID:24749558

  18. miR-148a is Associated with Obesity and Modulates Adipocyte Differentiation of Mesenchymal Stem Cells through Wnt Signaling

    PubMed Central

    Shi, Chunmei; Zhang, Min; Tong, Meiling; Yang, Lei; Pang, Lingxia; Chen, Ling; Xu, Guangfeng; Chi, Xia; Hong, Qin; Ni, Yuhui; Ji, Chenbo; Guo, Xirong

    2015-01-01

    Obesity results from numerous, interacting genetic, behavioral, and physiological factors. Adipogenesis is partially regulated by several adipocyte-selective microRNAs (miRNAs) and transcription factors that regulate proliferation and differentiation of human adipose-derived mesenchymal stem cells (hMSCs-Ad). In this study, we examined the roles of adipocyte-selective miRNAs in the differentiation of hMSCs-Ad to adipocytes. Results showed that the levels of miR-148a, miR-26b, miR-30, and miR-199a increased in differentiating hMSCs-Ad. Among these miRNAs, miR-148a exhibited significant effects on increasing PPRE luciferase activity (it represents PPAR-dependent transcription, a major factor in adipogenesis) than others. Furthermore, miR-148a expression levels increased in adipose tissues from obese people and mice fed high-fat diet. miR-148a acted by suppressing its target gene, Wnt1, an endogenous inhibitor of adipogenesis. Ectopic expression of miR-148a accelerated differentiation and partially rescued Wnt1-mediated inhibition of adipogenesis. Knockdown of miR-148a also inhibited adipogenesis. Analysis of the upstream region of miR-148a locus identified a 3 kb region containing a functional cAMP-response element-binding protein (CREB) required for miR-148a expression in hMSCs-Ad. The results suggest that miR-148a is a biomarker of obesity in human subjects and mouse model, which represents a CREB-modulated miRNA that acts to repress Wnt1, thereby promoting adipocyte differentiation. PMID:26001136

  19. Tribbles 3 Inhibits Brown Adipocyte Differentiation and Function by Suppressing Insulin Signaling

    PubMed Central

    Jeong, Ha-Won; Choi, Ran Hee; McClellan, Jamie L.; Piroli, Gerardo G.; Frizzell, Norma; Tseng, Yu-Hua; Goodyear, Laurie J.; Koh, Ho-Jin

    2016-01-01

    Recent studies have demonstrated that adult humans have substantial amounts of functioning brown adipose tissue (BAT). Since BAT has been implicated as an anti-obese and anti-diabetic tissue, it is important to understand the signaling molecules that regulate BAT function. There has been a link between insulin signaling and BAT metabolism as deletion or pharmaceutical inhibition of insulin signaling impairs BAT differentiation and function. Tribbles 3 (TRB3) is a pseudo kinase that has been shown to regulate metabolism and insulin signaling in multiple tissues but the role of TRB3 in BAT has not been studied. In this study, we found that TRB3 expression was present in BAT and overexpression of TRB3 in brown preadipocytes impaired differentiation and decreased expression of BAT markers. Furthermore, TRB3 overexpression resulted in significantly lower oxygen consumption rates for basal and proton leakage, indicating decreased BAT activity. Based on previous studies showing that deletion or pharmaceutical inhibition of insulin signaling impairs BAT differentiation and function, we assessed insulin signaling in brown preadipocytes and BAT in vivo. Overexpression of TRB3 in cells impaired insulin-stimulated IRS1 and Akt phosphorylation, whereas TRB3KO mice displayed improved IRS1 and Akt phosphorylation. Finally, deletion of IRS1 abolished the function of TRB3 to regulate BAT differentiation and metabolism. These data demonstrate that TRB3 inhibits insulin signaling in BAT, resulting in impaired differentiation and function. PMID:26801556

  20. Sitagliptin inhibit human lymphocytes proliferation and Th1/Th17 differentiation in vitro.

    PubMed

    Pinheiro, Marcelo Maia; Stoppa, Caroline Lais; Valduga, Claudete Justina; Okuyama, Cristina Eunice; Gorjão, Renata; Pereira, Regina Mara Silva; Diniz, Susana Nogueira

    2017-03-30

    Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of anti-diabetic agents that are widely used in clinical practice to improve glycemic control in patients with type 2 diabetes. DPP-4 is also known as lymphocyte cell surface protein, CD26, and plays an important role in T-cell immunity. Recent studies suggest that DPP-4 inhibitors improve beta-cell function and attenuate autoimmunity in type 1 diabetic mouse models. To investigate the direct effect of DPP4 in immune response, human peripheral blood mononuclear cells (PBMC) from healthy volunteers were obtained by Ficoll gradient and cultivated in the absence (control) or presence of phytohemagglutinin (PHA), or stimulated with PHA and treated with sitagliptin. The immune modulation mechanisms analyzed were: cell proliferation, by MTT assay; cytokine quantification by ELISA or cytometric bead array (CBA), Th1/Th2/Th17 phenotyping by flow cytometric analysis and CD26 gene expression by real time PCR. The results showed that sitagliptin treatment inhibited the proliferation of PBMC-PHA stimulated cells in a dose dependent manner and decreased CD26 expression by these cells, suggesting that sitagliptin may interfere in CD26 expression, dimerization and cell signaling. Sitagliptin treatment not only inhibited IL-10 (p<0.05) and IFN-gamma (p=0.07) cytokines, but also completely abolish IL-6 expression by PBMCs (p<0.001). On the other hand, IL-4 were secreted in culture supernatants from sitagliptin treated cells. A statistically significant increase (p<0.05) in the ratio of TGF-beta/proliferation index after sitagliptin treatment (2627.97±1351.65), when comparing to untreated cells (646.28±376.94), was also demonstrated, indicating higher TGF-beta1 production by viable cells in cultures. Sitagliptin treatment induced a significantly (p<0.05) decrease in IL-17 and IFN-gamma intracellular expression compared with PHA alone. Also, the percentage of T CD4(+)IL-17(+), T CD4(+)IFNgamma(+) and T CD4(+)IL-4(+) cells

  1. Differential effects of GABA in modulating nociceptive vs. non-nociceptive synapses.

    PubMed

    Wang, Y; Summers, T; Peterson, W; Miiller, E; Burrell, B D

    2015-07-09

    to nociceptive stimulation. These findings demonstrate that distinct synaptic inputs within a shared neural circuit can be differentially modulated by GABA in a functionally relevant manner.

  2. The induction of cellular senescence in dental follicle cells inhibits the osteogenic differentiation.

    PubMed

    Morsczeck, Christian; Gresser, Jan; Ettl, Tobias

    2016-06-01

    Dental stem cells such as human dental follicle cells (DFCs) have opened new promising treatment alternatives for today's dental health issues such as periodontal tissue regeneration. However, cellular senescence represents a restricting factor to cultured stem cells, resulting in limited lifespan and reduced cell differentiation potential. Therefore, this study evaluated if and how DFCs exhibit features of cellular senescence after being expanded in cell culture. The cell proliferation of DFCs decreased, while the cell size increased during prolonged cell culture. Moreover, DFCs expressed the senescence-associated β-galactosidase after a prolonged cell culture. The onset of senescence inhibited both the induction of osteoblast markers RUNX2 and osteopontin and the biomineralization of DFCs after stimulation of the osteogenic differentiation. In conclusion, we showed that a prolonged cell culture induces cellular senescence and inhibits the osteogenic differentiation in DFCs.

  3. Inhibition of Ca²⁺/calmodulin-dependent protein kinase kinase 2 stimulates osteoblast formation and inhibits osteoclast differentiation.

    PubMed

    Cary, Rachel L; Waddell, Seid; Racioppi, Luigi; Long, Fanxin; Novack, Deborah V; Voor, Michael J; Sankar, Uma

    2013-07-01

    Bone remodeling, a physiological process characterized by bone formation by osteoblasts (OBs) and resorption of preexisting bone matrix by osteoclasts (OCs), is vital for the maintenance of healthy bone tissue in adult humans. Imbalances in this vital process result in pathological conditions including osteoporosis. Owing to its initial asymptomatic nature, osteoporosis is often detected only after the patient has sustained significant bone loss or a fracture. Hence, anabolic therapeutics that stimulate bone accrual is in high clinical demand. Here we identify Ca²⁺/calmodulin (CaM)-dependent protein kinase kinase 2 (CaMKK2) as a potential target for such therapeutics because its inhibition enhances OB differentiation and bone growth and suppresses OC differentiation. Mice null for CaMKK2 possess higher trabecular bone mass in their long bones, along with significantly more OBs and fewer multinuclear OCs. In vitro, although Camkk2⁻/⁻ mesenchymal stem cells (MSCs) yield significantly higher numbers of OBs, bone marrow cells from Camkk2⁻/⁻ mice produce fewer multinuclear OCs. Acute inhibition of CaMKK2 by its selective, cell-permeable pharmacological inhibitor STO-609 also results in increased OB and diminished OC formation. Further, we find phospho-protein kinase A (PKA) and Ser¹³³ phosphorylated form of cyclic adenosine monophosphate (cAMP) response element binding protein (pCREB) to be markedly elevated in OB progenitors deficient in CaMKK2. On the other hand, genetic ablation of CaMKK2 or its pharmacological inhibition in OC progenitors results in reduced pCREB as well as significantly reduced levels of its transcriptional target, nuclear factor of activated T cells, cytoplasmic (NFATc1). Moreover, in vivo administration of STO-609 results in increased OBs and diminished OCs, conferring significant protection from ovariectomy (OVX)-induced osteoporosis in adult mice. Overall, our findings reveal a novel function for CaMKK2 in bone remodeling and

  4. Inhibition of adipocyte differentiation and adipogenesis by the traditional Chinese herb Sibiraea angustata.

    PubMed

    Xiao, Lei; Zhang, Jun; Li, Hongxing; Liu, Jin; He, Lan; Zhang, Junjie; Zhai, Yonggong

    2010-12-01

    Obesity has become a major health concern due to its strong association with the metabolic syndrome. Inhibition of adipocyte differentiation represents a key strategy to inhibit obesity. Sibiraea angustata (SA), a traditional Chinese herb, has a wide range of pharmacological effects, such as improving digestive functions. Here, we report a novel antiadipogenic effect of SA. By using the SA water extract (SAW), SA acetic ether extract (SAA) and the 3T3-L1 model of adipocyte differentiation and adipogenesis, we showed that both SAW and SAA impaired the proliferation and adipo-differentiation of 3T3-L1 in a dose- and time-dependent manner. At the molecular level, treatment of 3T3-L1 cells with SAW or SAA inhibited the expression of the key adipocyte differentiation regulator CCAAT enhancer binding protein β (C/EBPβ), as well as peroxisome proliferator activated receptor γ, adipocyte protein-2, lipoprotein lipase and glucose transporter 4. Cell cycle analysis showed that both SAW and SAA blocked cell cycle at the G1-S transition phase, causing cells to remain in the preadipocyte state. The expression of CyclinA and cyclin-dependent kinase 2 was also inhibited by SAW and SAA. Treatment with SAW also prevented the localization of C/EBPβ to the centromeres. Taken together, our results show that SA has a potent antiadipogenic effect in 3T3-L1 cells due to the inhibition of adipocyte differentiation and adipogenesis. We propose that SA may be used as a safe and effective neutraceutical to manage obesity.

  5. Allosteric modulation of sigma-1 receptors by SKF83959 inhibits microglia-mediated inflammation.

    PubMed

    Wu, Zhuang; Li, Linlang; Zheng, Long-Tai; Xu, Zhihong; Guo, Lin; Zhen, Xuechu

    2015-09-01

    Recent studies have shown that sigma-1 receptor orthodox agonists can inhibit neuroinflammation. SKF83959 (3-methyl-6-chloro-7,8-hydroxy-1-[3-methylphenyl]-2,3,4,5-tetrahydro-1H-3-benzazepine), an atypical dopamine receptor-1 agonist, has been recently identified as a potent allosteric modulator of sigma-1 receptor. Here, we investigated the anti-inflammatory effects of SKF83959 in lipopolysaccharide (LPS)-stimulated BV2 microglia. Our results indicated that SKF83959 significantly suppressed the expression/release of the pro-inflammatory mediators, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS), and inhibited the generation of reactive oxygen species. All of these responses were blocked by selective sigma-1 receptor antagonists (BD1047 or BD1063) and by ketoconazole (an inhibitor of enzyme cytochrome c17 to inhibit the synthesis of endogenous dehydroepiandrosterone, DHEA). Additionally, we found that SKF83959 promoted the binding activity of DHEA with sigma-1 receptors, and enhanced the inhibitory effects of DHEA on LPS-induced microglia activation in a synergic manner. Furthermore, in a microglia-conditioned media system, SKF83959 inhibited the cytotoxicity of conditioned medium generated by LPS-activated microglia toward HT-22 neuroblastoma cells. Taken together, our study provides the first evidence that allosteric modulation of sigma-1 receptors by SKF83959 inhibits microglia-mediated inflammation. SKF83959 is a potent allosteric modulator of sigma-1 receptor. Our results indicated that SKF83959 enhanced the activity of endogenous dehydroepiandrosterone (DHEA) in a synergic manner, and inhibited the activation of BV2 microglia and the expression/release of the pro-inflammatory mediators, such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase (iNOS).

  6. Differential paralog divergence modulates genome evolution across yeast species

    PubMed Central

    Lynch, Bryony; Huang, Mei; Alcantara, Erica; DeSevo, Christopher G.; Pai, Dave A.; Hoang, Margaret L.

    2017-01-01

    Evolutionary outcomes depend not only on the selective forces acting upon a species, but also on the genetic background. However, large timescales and uncertain historical selection pressures can make it difficult to discern such important background differences between species. Experimental evolution is one tool to compare evolutionary potential of known genotypes in a controlled environment. Here we utilized a highly reproducible evolutionary adaptation in Saccharomyces cerevisiae to investigate whether experimental evolution of other yeast species would select for similar adaptive mutations. We evolved populations of S. cerevisiae, S. paradoxus, S. mikatae, S. uvarum, and interspecific hybrids between S. uvarum and S. cerevisiae for ~200–500 generations in sulfate-limited continuous culture. Wild-type S. cerevisiae cultures invariably amplify the high affinity sulfate transporter gene, SUL1. However, while amplification of the SUL1 locus was detected in S. paradoxus and S. mikatae populations, S. uvarum cultures instead selected for amplification of the paralog, SUL2. We measured the relative fitness of strains bearing deletions and amplifications of both SUL genes from different species, confirming that, converse to S. cerevisiae, S. uvarum SUL2 contributes more to fitness in sulfate limitation than S. uvarum SUL1. By measuring the fitness and gene expression of chimeric promoter-ORF constructs, we were able to delineate the cause of this differential fitness effect primarily to the promoter of S. uvarum SUL1. Our data show evidence of differential sub-functionalization among the sulfate transporters across Saccharomyces species through recent changes in noncoding sequence. Furthermore, these results show a clear example of how such background differences due to paralog divergence can drive changes in genome evolution. PMID:28196070

  7. Smurf1 plays a role in EGF inhibition of BMP2-induced osteogenic differentiation

    SciTech Connect

    Lee, Hye-Lim; Park, Hyun-Jung; Kwon, Arang; Baek, Kyunghwa; Woo, Kyung Mi; Ryoo, Hyun-Mo; Kim, Gwan-Shik; Baek, Jeong-Hwa

    2014-05-01

    It has been demonstrated that epidermal growth factor (EGF) plays a role in supporting the proliferation of bone marrow stromal cells in bone but inhibits their osteogenic differentiation. However, the mechanism underlying EGF inhibition of osteoblast differentiation remains unclear. Smurf1 is an E3 ubiquitin ligase that targets Smad1/5 and Runx2, which are critical transcription factors for bone morphogenetic protein 2 (BMP2)-induced osteoblast differentiation. In this study, we investigated the effect of EGF on the expression of Smurf1, and the role of Smurf1 in EGF inhibition of osteogenic differentiation using C2C12 cells, a murine myoblast cell line. EGF increased Smurf1 expression, which was blocked by inhibiting the activity of either JNK or ERK. Chromatin immunoprecipitation and Smurf1 promoter assays demonstrated that c-Jun and Runx2 play roles in the EGF induction of Smurf1 transcription. EGF suppressed BMP2-induced expression of osteogenic marker genes, which were rescued by Smurf1 knockdown. EGF downregulated the protein levels of Runx2 and Smad1 in a proteasome-dependent manner. EGF decreased the transcriptional activity of Runx2 and Smurf1, which was partially rescued by Smurf1 silencing. Taken together, these results suggest that EGF increases Smurf1 expression via the activation of JNK and ERK and the subsequent binding of c-Jun and Runx2 to the Smurf1 promoter and that Smurf1 mediates the inhibitory effect of EGF on BMP2-induced osteoblast differentiation. - Highlights: • EGF increases the expression level of Smurf1 in mesenchymal precursor cells. • EGF reduces the protein levels and transcriptional activity of Runx2 and Smad1. • EGF suppresses BMP2-induced osteogenic differentiation, which is rescued by Smurf1 knockdown.

  8. Collagen scaffold microenvironments modulate cell lineage commitment for differentiation of bone marrow cells into regulatory dendritic cells

    PubMed Central

    Fang, Yongxiang; Wang, Bin; Zhao, Yannan; Xiao, Zhifeng; Li, Jing; Cui, Yi; Han, Sufang; Wei, Jianshu; Chen, Bing; Han, Jin; Meng, Qingyuan; Hou, Xianglin; Luo, Jianxun; Dai, Jianwu; Jing, Zhizhong

    2017-01-01

    The microenvironment plays a pivotal role for cell survival and functional regulation, and directs the cell fate determination. The biological functions of DCs have been extensively investigated to date. However, the influences of the microenvironment on the differentiation of bone marrow cells (BMCs) into dendritic cells (DCs) are not well defined. Here, we established a 3D collagen scaffold microenvironment to investigate whether such 3D collagen scaffolds could provide a favourable niche for BMCs to differentiate into specialised DCs. We found that BMCs embedded in the 3D collagen scaffold differentiated into a distinct subset of DC, exhibiting high expression of CD11b and low expression of CD11c, co-stimulator (CD40, CD80, CD83, and CD86) and MHC-II molecules compared to those grown in 2D culture. DCs cultured in the 3D collagen scaffold possessed weak antigen uptake ability and inhibited T-cell proliferation in vitro; in addition, they exhibited potent immunoregulatory function to alleviate allo-delay type hypersensitivity when transferred in vivo. Thus, DCs differentiated in the 3D collagen scaffold were defined as regulatory DCs, indicating that collagen scaffold microenvironments probably play an important role in modulating the lineage commitment of DCs and therefore might be applied as a promising tool for generation of specialised DCs. PMID:28169322

  9. Metabolic Inflammation-Differential Modulation by Dietary Constituents.

    PubMed

    Lyons, Claire L; Kennedy, Elaine B; Roche, Helen M

    2016-04-27

    Obesity arises from a sustained positive energy balance which triggers a pro-inflammatory response, a key contributor to metabolic diseases such as T2D. Recent studies, focused on the emerging area of metabolic-inflammation, highlight that specific metabolites can modulate the functional nature and inflammatory phenotype of immune cells. In obesity, expanding adipose tissue attracts immune cells, creating an inflammatory environment within this fatty acid storage organ. Resident immune cells undergo both a pro-inflammatory and metabolic switch in their function. Inflammatory mediators, such as TNF-α and IL-1β, are induced by saturated fatty acids and disrupt insulin signaling. Conversely, monounsaturated and polyunsaturated fatty acids do not interrupt metabolism and inflammation to the same extent. AMPK links inflammation, metabolism and T2D, with roles to play in all and is influenced negatively by obesity. Lipid spillover results in hepatic lipotoxicity and steatosis. Also in skeletal muscle, excessive FFA can impede insulin's action and promote inflammation. Ectopic fat can also affect pancreatic β-cell function, thereby contributing to insulin resistance. Therapeutics, lifestyle changes, supplements and dietary manipulation are all possible avenues to combat metabolic inflammation and the subsequent insulin resistant state which will be explored in the current review.

  10. Metabolic Inflammation-Differential Modulation by Dietary Constituents

    PubMed Central

    Lyons, Claire L.; Kennedy, Elaine B.; Roche, Helen M.

    2016-01-01

    Obesity arises from a sustained positive energy balance which triggers a pro-inflammatory response, a key contributor to metabolic diseases such as T2D. Recent studies, focused on the emerging area of metabolic-inflammation, highlight that specific metabolites can modulate the functional nature and inflammatory phenotype of immune cells. In obesity, expanding adipose tissue attracts immune cells, creating an inflammatory environment within this fatty acid storage organ. Resident immune cells undergo both a pro-inflammatory and metabolic switch in their function. Inflammatory mediators, such as TNF-α and IL-1β, are induced by saturated fatty acids and disrupt insulin signaling. Conversely, monounsaturated and polyunsaturated fatty acids do not interrupt metabolism and inflammation to the same extent. AMPK links inflammation, metabolism and T2D, with roles to play in all and is influenced negatively by obesity. Lipid spillover results in hepatic lipotoxicity and steatosis. Also in skeletal muscle, excessive FFA can impede insulin’s action and promote inflammation. Ectopic fat can also affect pancreatic β-cell function, thereby contributing to insulin resistance. Therapeutics, lifestyle changes, supplements and dietary manipulation are all possible avenues to combat metabolic inflammation and the subsequent insulin resistant state which will be explored in the current review. PMID:27128935

  11. [Inhibition of NHE1 promotes hypoxia-induced differentiation of K562 leukemic cells].

    PubMed

    Jin, Wei-Na; Wang, Jian; Chang, Guo-Qiang; Lin, Ya-Ni; Wang, Li-Hong; Li, Hua-Wen; Gao, Wei; Li, Qing-Hua; Pang, Tian-Xiang

    2011-06-01

    This study was purposed to investigate the effect of hypoxia microenvironment on K562 leukemic cell differentiation, and characteristics of NHE1 involvement in this process. The K562 cells were treated with hypoxia-mimical agent CoCl₂ or under actual hypoxia culture, and the specific NHE1 inhibitor Cariporide was used to inhibit NHE1 activity. The fluorescent probe BCECF was used for pH(i) measurements. Gene expression was analyzed by RT-PCR. The morphological characteristics was determined by Wright's staining. Signaling pathways were detected by Western blot using phosphospecific antibodies. The results indicated that the hypoxia or mimetic hypoxia favored K562 cells differentiation with up-regulation of C/EBPα. Moreover, treatment with Cariporide under hypoxia synergistically enhanced leukemia cell differentiation. Treatment with Cariporide increased levels of phosphorylated ERK5 and P38 mitogen-activated protein kinase (MAPK). It is concluded that the hypoxia or mimetic hypoxia can induce the differentiation of K562 cells, the inhibition of NHE1 activity can promote the hypoxia-induced K562 cell differentiation. The enhancement of hypoxia-induced K562 differentiation by Cariporide via MAPK signal pathway suggests a possible therapeutic target of NHE1 under hypoxia microenvironment in the treatment of leukemias.

  12. miR-125b inhibits osteoblastic differentiation by down-regulation of cell proliferation

    SciTech Connect

    Mizuno, Yosuke; Yagi, Ken; Tokuzawa, Yoshimi; Kanesaki-Yatsuka, Yukiko; Suda, Tatsuo; Katagiri, Takenobu; Fukuda, Toru; Maruyama, Masayoshi; Okuda, Akihiko; Amemiya, Tomoyuki; Kondoh, Yasumitsu; Tashiro, Hideo; Okazaki, Yasushi

    2008-04-04

    Although various microRNAs regulate cell differentiation and proliferation, no miRNA has been reported so far to play an important role in the regulation of osteoblast differentiation. Here we describe the role of miR-125b in osteoblastic differentiation in mouse mesenchymal stem cells, ST2, by regulating cell proliferation. The expression of miR-125b was time-dependently increased in ST2 cells, and the increase in miR-125b expression was attenuated in osteoblastic-differentiated ST2 cells induced by BMP-4. The transfection of exogenous miR-125b inhibited proliferation of ST2 cells and caused inhibition of osteoblastic differentiation. In contrast, when the endogenous miR-125b was blocked by transfection of its antisense RNA molecule, alkaline phosphatase activity after BMP-4 treatment was elevated. These results strongly suggest that miR-125b is involved in osteoblastic differentiation through the regulation of cell proliferation.

  13. Reconstructing differentially co-expressed gene modules and regulatory networks of soybean cells

    PubMed Central

    2012-01-01

    Background Current experimental evidence indicates that functionally related genes show coordinated expression in order to perform their cellular functions. In this way, the cell transcriptional machinery can respond optimally to internal or external stimuli. This provides a research opportunity to identify and study co-expressed gene modules whose transcription is controlled by shared gene regulatory networks. Results We developed and integrated a set of computational methods of differential gene expression analysis, gene clustering, gene network inference, gene function prediction, and DNA motif identification to automatically identify differentially co-expressed gene modules, reconstruct their regulatory networks, and validate their correctness. We tested the methods using microarray data derived from soybean cells grown under various stress conditions. Our methods were able to identify 42 coherent gene modules within which average gene expression correlation coefficients are greater than 0.8 and reconstruct their putative regulatory networks. A total of 32 modules and their regulatory networks were further validated by the coherence of predicted gene functions and the consistency of putative transcription factor binding motifs. Approximately half of the 32 modules were partially supported by the literature, which demonstrates that the bioinformatic methods used can help elucidate the molecular responses of soybean cells upon various environmental stresses. Conclusions The bioinformatics methods and genome-wide data sources for gene expression, clustering, regulation, and function analysis were integrated seamlessly into one modular protocol to systematically analyze and infer modules and networks from only differential expression genes in soybean cells grown under stress conditions. Our approach appears to effectively reduce the complexity of the problem, and is sufficiently robust and accurate to generate a rather complete and detailed view of putative soybean

  14. Differential modulation by extracellular ATP of carotid chemosensory responses.

    PubMed

    Spergel, D; Lahiri, S

    1993-06-01

    The possibility that the carotid body has ATP surface receptors that mediate O2 chemoreception was tested. To distinguish between the event(s) initiating chemoreception and those at the neurotransmitter level, we also tested the chemosensory response to nicotine before and after ATP administration. Carotid bodies from cats anesthetized with pentobarbital sodium were perfused and superfused in vitro with modified Tyrode solution (PCO2 < 1 Torr, pH 7.4, 36 degrees C) equilibrated at PO2 > 400 or approximately 150 Torr while chemosensory discharge was recorded extracellularly. ATP and adenosine 5'-[gamma-thio]triphosphate stimulated discharge with similar dose dependence, whereas adenosine had little effect. ATP infusion for > or = 2 min evoked an initial stimulation of discharge followed by a decline to baseline (desensitization). Desensitization did not affect the response to hypoxia (perfusate flow interruption) but inhibited the response to nicotine (4-nmol pulse). Therefore, 1) the carotid body has surface ATP receptors that may mediate the chemosensory response to nicotine but not to hypoxia and 2) nicotinic receptors are not required for carotid body O2 chemoreception.

  15. The use of small interfering RNAs to inhibit adipocyte differentiation in human preadipocytes and fetal-femur-derived mesenchymal cells

    SciTech Connect

    Xu, Y.; Mirmalek-Sani, S.-H.; Yang, X.; Zhang, J.; Oreffo, R.O.C. . E-mail: roco@soton.ac.uk

    2006-06-10

    RNA interference (RNAi) has been used in functional genomics and offers innovative approaches in the development of novel therapeutics. Human mesenchymal stem cells offer a unique cell source for tissue engineering/regeneration strategies. The current study examined the potential of small interfering RNAs (siRNA) against human peroxisome proliferator activated receptor gamma (PPAR{gamma}) to suppress adipocyte differentiation (adipogenesis) in human preadipocytes and fetal-femur-derived mesenchymal cells. Adipogenesis was investigated using cellular and biochemical analysis. Transient transfection with PPAR{gamma}-siRNA using a liposomal-based strategy resulted in a significant inhibition of adipogenesis in human preadipocytes and fetal-femur-derived mesenchymal cells, compared to controls (cell, liposomal and negative siRNA). The inhibitory effect of PPAR{gamma}-siRNA was supported by testing human PPAR{gamma} mRNA and adipogenic associated genes using reverse transcription polymerase chain reaction (RT-PCR) to adiponectin receptor 1 and 2 as well as examination of fatty acid binding protein 3 (FABP{sub 3}) expression, an adipocyte-specific marker. The current studies indicate that PPAR{gamma}-siRNA is a useful tool to study adipogenesis in human cells, with potential applications both therapeutic and in the elucidation of mesenchymal cell differentiation in the modulation of cell differentiation in human mesenchymal cells.

  16. HO-1 inhibits preadipocyte proliferation and differentiation at the onset of obesity via ROS dependent activation of Akt2

    PubMed Central

    Wagner, Gabriel; Lindroos-Christensen, Josefine; Einwallner, Elisa; Husa, Julia; Zapf, Thea-Christin; Lipp, Katharina; Rauscher, Sabine; Gröger, Marion; Spittler, Andreas; Loewe, Robert; Gruber, Florian; Duvigneau, J. Catharina; Mohr, Thomas; Sutterlüty-Fall, Hedwig; Klinglmüller, Florian; Prager, Gerhard; Huppertz, Berthold; Yun, Jeanho; Wagner, Oswald; Esterbauer, Harald; Bilban, Martin

    2017-01-01

    Excessive accumulation of white adipose tissue (WAT) is a hallmark of obesity. The expansion of WAT in obesity involves proliferation and differentiation of adipose precursors, however, the underlying molecular mechanisms remain unclear. Here, we used an unbiased transcriptomics approach to identify the earliest molecular underpinnings occuring in adipose precursors following a brief HFD in mice. Our analysis identifies Heme Oxygenase-1 (HO-1) as strongly and selectively being upregulated in the adipose precursor fraction of WAT, upon high-fat diet (HFD) feeding. Specific deletion of HO-1 in adipose precursors of Hmox1fl/flPdgfraCre mice enhanced HFD-dependent visceral adipose precursor proliferation and differentiation. Mechanistically, HO-1 reduces HFD-induced AKT2 phosphorylation via ROS thresholding in mitochondria to reduce visceral adipose precursor proliferation. HO-1 influences adipogenesis in a cell-autonomous way by regulating events early in adipogenesis, during the process of mitotic clonal expansion, upstream of Cebpα and PPARγ. Similar effects on human preadipocyte proliferation and differentiation in vitro were observed upon modulation of HO-1 expression. This collectively renders HO-1 as an essential factor linking extrinsic factors (HFD) with inhibition of specific downstream molecular mediators (ROS & AKT2), resulting in diminished adipogenesis that may contribute to hyperplastic adipose tissue expansion. PMID:28102348

  17. A screen for Fli-1 transcriptional modulators identifies PKC agonists that induce erythroid to megakaryocytic differentiation and suppress leukemogenesis.

    PubMed

    Liu, Tangjingjun; Yao, Yao; Zhang, Gang; Wang, Ye; Deng, Bin; Song, Jialei; Li, Xiaogang; Han, Fei; Xiao, Xiao; Yang, Jue; Xia, Lei; Li, You-Jun; Plachynta, Maksym; Zhang, Mu; Yan, Chen; Mu, Shuzhen; Luo, Heng; Zacksenhaus, Eldad; Hao, Xiaojiang; Ben-David, Yaacov

    2016-12-30

    The ETS-related transcription factor Fli-1 affects many developmental programs including erythroid and megakaryocytic differentiation, and is frequently de-regulated in cancer. Fli-1 was initially isolated following retrovirus insertional mutagenesis screens for leukemic initiator genes, and accordingly, inhibition of this transcription factor can suppress leukemia through induction of erythroid differentiation. To search for modulators of Fli-1, we hereby performed repurposing drug screens with compounds isolated from Chinese medicinal plants. We identified agents that can transcriptionally activate or inhibit a Fli-1 reporter. Remarkably, agents that increased Fli-1 transcriptional activity conferred a strong anti-cancer activity upon Fli-1-expressing leukemic cells in culture. As opposed to drugs that suppress Fli1 activity and lead to erythroid differentiation, growth suppression by these new Fli-1 transactivating compounds involved erythroid to megakaryocytic conversion (EMC). The identified compounds are structurally related to diterpene family of small molecules, which are known agonists of protein kinase C (PKC). In accordance, these PKC agonists (PKCAs) induced PKC phosphorylation leading to activation of the mitogen-activated protein kinase (MAPK) pathway, increased cell attachment and EMC, whereas pharmacological inhibition of PKC or MAPK diminished the effect of our PKCAs. Moreover, in a mouse model of leukemia initiated by Fli-1 activation, the PKCA compounds exhibited strong anti-cancer activity, which was accompanied by increased presence of CD41/CD61 positive megakaryocytic cells in leukemic spleens. Thus, PKC agonists offer a novel approach to combat Fli-1-induced leukemia, and possibly other cancers,by inducing EMC in part through over-activation of the PKC-MAPK-Fli-1 pathway.

  18. Idesolide inhibits the adipogenic differentiation of mesenchymal cells through the suppression of nitric oxide production.

    PubMed

    Hwang, Jun-Ha; Moon, Sung Ah; Lee, Cham Han; Byun, Mi Ran; Kim, A Rum; Sung, Mi Kyung; Park, Hyun-Jin; Hwang, Eun Sook; Sung, Sang Hyun; Hong, Jeong-Ho

    2012-06-15

    Obesity is a major health problem worldwide and can increase the risk for several chronic diseases, including diabetes and cardiovascular disease. In this study, we screened small compounds isolated from natural products for the development of an anti-obesity drug. Among them, idesolide, a spiro compound isolated from the fruits of Idesia polycarpa Maxim, showed a significant suppression of the adipogenic differentiation in mesenchymal cells, as indicated by the decrease in fat droplets and expression of adipogenic marker genes such as aP2 and adiponectin. Idesolide inhibits the PPARγ-mediated gene transcription in a dose-dependent manner, revealed by luciferase reporter gene assay. During adipogenic differentiation, idesolide inhibits nitric oxide production through the suppression of iNOS expression, and the increased adipogenic differentiation by arginine, the substrate for NOS, is significantly inhibited by idesolide, suggesting that the inhibition of nitric oxide production plays a major role in idesolide-induced adipogenic suppression. Taken together, the results reveal that idesolide has anti-adipogenic activity and highlight its potential in the prevention and treatment of obesity.

  19. [The evoked activity of the lateral hypothalamus during extinction and differential inhibition].

    PubMed

    Vanetsian, G L

    1995-01-01

    Character of interaction between symmetric points of the cat's auditory cortex (A1) and the lateral hypothalamus (HL) was determined by calculating Spearman correlation coefficients between averaged summed sound-evoked activity (AEP) of the structures before, during elaboration, extinction and restoration, as well as differentiation of food-procuring conditioned reflex and in the eating full. Close mutual co-tuning between the cortex and hypothalamus characteristic for stable conditioned reflex was found to disrupted during its extinction, elaboration of differentiation and fullness eat inhibition due to entire reduction of hypothalamic AEP and disappearance of correlated with negativity of HL AEP "doubling" of the first positive wave of A1 AEP. Hyperactivity stage, expressed at the beginning of extinction and at the end of differentiation, preceded inactivation of hypothalamic afferents during elaboration of conditioned inhibition. The stage of hyperactivity, initiated by the elevated emotional state of the animal, testifies to an important role of emotional brain structures in the process of internal inhibition. The stage of HL and A1 hyperactivity initiated by emotional stress of the animal and following HL inactivation during inhibition of the conditioned response point to an important role of emotional subcortical brain structures in the mechanisms of inhibitory conditioning.

  20. DIFFERENTIAL MODULATION OF CATECHOLAMINES BY CHLOROTRIAZINE HERBICIDES IN PHEOCHROMOCYTOMA (PC12) CELLS IN VITRO

    EPA Science Inventory

    Differential modulation of catecholamines by chlorotriazine herbicides in pheochromocytoma (PC12) cells in vitro.

    Das PC, McElroy WK, Cooper RL.

    Curriculum in Toxicology, University of North Carolina, Chapel Hill 27599, USA.

    Epidemiological, wildlife, and lab...

  1. Differential Space-Time Coding Scheme Using Star Quadrature Amplitude Modulation Method

    NASA Astrophysics Data System (ADS)

    Yu, Xiangbin; Xu, DaZhuan; Bi, Guangguo

    2006-12-01

    Differential space-time coding (DSTC) has received much interest as it obviates the requirement of the channel state information at the receiver while maintaining the desired properties of space-time coding techniques. In this paper, by introducing star quadrature amplitude modulation (star QAM) method, two kinds of multiple amplitudes DSTC schemes are proposed. One is based on differential unitary space-time coding (DUSTC) scheme, and the other is based on differential orthogonal space-time coding (DOSTC) scheme. Corresponding bit-error-rate (BER) performance and coding-gain analysis are given, respectively. The proposed schemes can avoid the performance loss of conventional DSTC schemes based on phase-shift keying (PSK) modulation in high spectrum efficiency via multiple amplitudes modulation. Compared with conventional PSK-based DSTC schemes, the developed schemes have higher spectrum efficiency via carrying information not only on phases but also on amplitudes, and have higher coding gain. Moreover, the first scheme can implement low-complexity differential modulation and different code rates and be applied to any number of transmit antennas; while the second scheme has simple decoder and high code rate in the case of 3 and 4 antennas. The simulation results show that our schemes have lower BER when compared with conventional DUSTC and DOSTC schemes.

  2. Epigallocatechin Gallate Inhibits Mouse Mesenchymal Stem Cell Differentiation to Adipogenic Lineage.

    PubMed

    Chani, Baldeep; Puri, Veena; Chander Sobti, Ranbir; Puri, Sanjeev

    2016-01-01

    Epigallocatechin gallate (EGCG) is a major component of green tea polyphenols having a potent anti-oxidant potential. Besides inhibiting the growth of many cancer cell types and inducing proliferation and differentiation in keratinocytes, it has been shown to promote reduction of body fat. The fact that mesenchymal stem cells (MSCs) have ability to self-renew and differentiate into the cells of mesodermal lineages, such as fat and bone, it is, thus, possible that EGCG may directly be involved in affecting fat metabolism through its effect on mesenchymal stem cells. Hence, with this aim, the present study was designed to determine the effect of EGCG on mouse mesenchymal stem cells, C3H10T1/2 cells differentiation into adipocytes. To understand this process, the cells were incubated with varying concentrations of EGCG (1 μM, 5 μM, 10 μM, 50 μM) in the presence and /or absence of adipogenic medium for 9 days. The results demonstrated that, EGCG inhibited the cells proliferation, migration and also prevented their differentiation to adipogenic lineage. These effects were analyzed through the inhibition of wound healing activity, reduction in Oil red O stained cells, together with decrease in the expression of Adipisin gene following EGCG treatment. These observations thus demonstrated anti-adipogenic effect of EGCG with a possibility of its role in the therapeutic intervention of obesity.

  3. Dexamethasone inhibits the differentiation of rat tendon stem cells into tenocytes by targeting the scleraxis gene.

    PubMed

    Chen, Wan; Tang, Hong; Zhou, Mei; Hu, Chao; Zhang, Jiqiang; Tang, Kanglai

    2015-08-01

    Glucocorticoid-induced tendon rupture is very common in clinical practice, and the overall outcome of surgical suture repair is rather poor. The mechanism remains unclear, and effective treatments are still lacking. In the present study, we investigated the effect of dexamethasone on the differentiation of rat tendon stem cells (TSCs) to tenocytes and the underlying molecular mechanisms and found that dexamethasone inhibits the differentiation of TSCs to tenocytes by analyzing the development of long, spindle-shaped cells and detecting the expression of tenocyte markers type I collagen and tenomodulin (TNMD) at both the mRNA and protein levels. We also discovered that after treatment with dexamethasone, the scleraxis expression level is downregulated in vitro and in human specimen. Chromatin immunoprecipitation (ChIP)-PCR showed that dexamethasone promotes glucocorticoid receptor interacted with the TGGAAGCC sequence located between -734 and -726 base pairs (bp) upstream of the start codon of the scleraxis gene. Furthermore, TSCs were transfected with scleraxis knockdown or overexpression plasmids, and the results indicated that scleraxis plays a pivotal role in the differentiation of TSCs to tenocytes. In conclusion, dexamethasone inhibits the differentiation of TSCs to tenocytes by inhibiting the scleraxis gene.

  4. Curcumin Inhibits Transforming Growth Factor β Induced Differentiation of Mouse Lung Fibroblasts to Myofibroblasts

    PubMed Central

    Liu, Daishun; Gong, Ling; Zhu, Honglan; Pu, Shenglan; Wu, Yang; Zhang, Wei; Huang, Guichuan

    2016-01-01

    Transforming growth factor β (TGF-β) induced differentiation of lung fibroblasts to myofibroblasts is a key event in the pathogenesis of pulmonary fibrosis. This study aimed to evaluate the effect of curcumin on TGF-β induced differentiation of lung fibroblasts to myofibroblasts and explore the underlying mechanism. Mouse lung fibroblasts were cultured and treated with TGF-β2 and curcumin or rosiglitazone. Cell vitality was examined by MTT assay. The secretion of collagen-1 was assessed by ELISA. α smooth muscle actin (α-SMA) was visualized by immunofluorescence technique. The expression of peroxisome proliferator activated receptor γ (PPAR-γ) and platelet derived growth factor R β (PDGFR-β) was detected by PCR and Western blot analysis. We found that curcumin and rosiglitazone inhibited the proliferation and TGF-β induced differentiation of mouse lung fibroblasts. In addition, curcumin and rosiglitazone inhibited collagen-1 secretion and α-SMA expression in mouse lung fibroblasts. Furthermore, curcumin and rosiglitazone upregulated PPAR-γ and downregulated PDGFR-β expression in mouse lung fibroblasts. In conclusion, our study reveals novel mechanism by which curcumin inhibits TGF-β2 driven differentiation of lung fibroblasts to myofibroblasts. Curcumin could potentially be used for effective treatment of pulmonary fibrosis. PMID:27877129

  5. Neuropeptide Y1 Receptor Regulates Glucocorticoid-Induced Inhibition of Osteoblast Differentiation in Murine MC3T3-E1 Cells via ERK Signaling.

    PubMed

    Yu, Wei; Zhu, Chao; Xu, Wenning; Jiang, Leisheng; Jiang, Shengdan

    2016-12-21

    High dose glucocorticoid (GC) administration impairs the viability and function of osteoblasts, thus causing osteoporosis and osteonecrosis. Neuropeptide Y1 receptor (Y1 receptor) is expressed in bone tissues and cells, and regulates bone remodeling. However, the role of Y1 receptor in glucocorticoid-induced inhibition of osteoblast differentiation remains unknown. In the present study, osteoblastic cell line MC3T3-E1 cultured in osteogenic differentiation medium was treated with or without of 10(-7) M dexamethasone (Dex), Y1 receptor shRNA interference, Y1 receptor agonist [Leu(31), Pro(34)]-NPY, and antagonist BIBP3226. Cell proliferation and apoptosis were assessed by cell counting kit-8 (CCK-8) assay and cleaved caspase expression, respectively. Osteoblast differentiation was evaluated by Alizarin Red S staining and osteogenic marker gene expressions. Protein expression was detected by Western blot analysis. Dex upregulated the expression of Y1 receptor in MC3T3-E1 cells associated with reduced osteogenic gene expressions and mineralization. Blockade of Y1 receptor by shRNA transfection and BIBP3226 significantly attenuated the inhibitory effects of Dex on osteoblastic activity. Y1 receptor signaling modulated the activation of extracellular signal-regulated kinases (ERK) as well as the expressions of osteogenic genes. Y1 receptor agonist inhibited ERK phosphorylation and osteoblast differentiation, while Y1 receptor blockade exhibited the opposite effects. Activation of ERK signaling by constitutive active mutant of MEK1 (caMEK) abolished Y1 receptor-mediated Dex inhibition of osteoblast differentiation in MC3T3-E1 cells. Taken together, Y1 receptor regulates Dex-induced inhibition of osteoblast differentiation in murine MC3T3-E1 cells via ERK signaling. This study provides a novel role of Y1 receptor in the process of GC-induced suppression in osteoblast survival and differentiation.

  6. LINGO-1, a transmembrane signaling protein, inhibits oligodendrocyte differentiation and myelination through intercellular self-interactions.

    PubMed

    Jepson, Scott; Vought, Bryan; Gross, Christian H; Gan, Lu; Austen, Douglas; Frantz, J Daniel; Zwahlen, Jacque; Lowe, Derek; Markland, William; Krauss, Raul

    2012-06-22

    Overcoming remyelination failure is a major goal of new therapies for demyelinating diseases like multiple sclerosis. LINGO-1, a key negative regulator of myelination, is a transmembrane signaling protein expressed in both neurons and oligodendrocytes. In neurons, LINGO-1 is an integral component of the Nogo receptor complex, which inhibits axonal growth via RhoA. Because the only ligand-binding subunit of this complex, the Nogo receptor, is absent in oligodendrocytes, the extracellular signals that inhibit myelination through a LINGO-1-mediated mechanism are unknown. Here we show that LINGO-1 inhibits oligodendrocyte terminal differentiation through intercellular interactions and is capable of a self-association in trans. Consistent with previous reports, overexpression of full-length LINGO-1 inhibited differentiation of oligodendrocyte precursor cells (OPCs). Unexpectedly, treatment with a soluble recombinant LINGO-1 ectodomain also had an inhibitory effect on OPCs and decreased myelinated axonal segments in cocultures with neurons from dorsal root ganglia. We demonstrated LINGO-1-mediated inhibition of OPCs through intercellular signaling by using a surface-bound LINGO-1 construct expressed ectopically in astrocytes. Further investigation showed that the soluble LINGO-1 ectodomain can interact with itself in trans by binding to CHO cells expressing full-length LINGO-1. Finally, we observed that soluble LINGO-1 could activate RhoA in OPCs. We propose that LINGO-1 acts as both a ligand and a receptor and that the mechanism by which it negatively regulates OPC differentiation and myelination is mediated by a homophilic intercellular interaction. Disruption of this protein-protein interaction could lead to a decrease of LINGO-1 inhibition and an increase in myelination.

  7. ATF3 inhibits adipocyte differentiation of 3T3-L1 cells

    SciTech Connect

    Jang, Min Kyung; Kim, Cho Hee; Seong, Je Kyung; Jung, Myeong Ho

    2012-04-27

    Highlights: Black-Right-Pointing-Pointer Overexpression of ATF3 inhibits adipocyte differentiation in 3T3-L1 cells. Black-Right-Pointing-Pointer Overexpression of ATF3 represses C/EBP{alpha} expression. Black-Right-Pointing-Pointer ATF3 directly binds to mouse C/EBP{alpha} promoter spanning from -1928 to -1907. Black-Right-Pointing-Pointer ATF3 may play a role in hypoxia-mediated inhibition of adipocyte differentiation. -- Abstract: ATF3 is a stress-adaptive gene that regulates proliferation or apoptosis under stress conditions. However, the role of ATF3 is unknown in adipocyte cells. Therefore, in this study, we investigated the functional role of ATF3 in adipocytes. Both lentivirus-mediated overexpression of ATF3 and stably-overexpressed ATF3 inhibited adipocyte differentiation in 3T3-L1 cells, as revealed by decreased lipid staining with oil red staining and reduction in adipogenic genes. Thapsigargin treatment and overexpression of ATF3 decreased C/EBP{alpha} transcript and repressed the activity of the 3.6-kb mouse C/EBP{alpha} promoter, demonstrating that ATF3 downregulates C/EBP{alpha} expression. Transfection studies using mutant constructs containing 5 Prime -deletions in the C/EBP{alpha} promoter revealed that a putative ATF/CRE element, GGATGTCA, is located between -1921 and -1914. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrated that ATF3 directly binds to mouse C/EBP{alpha} promoter spanning from -1928 to -1907. Both chemical hypoxia-mimetics or physical hypoxia led to reduce the C/EBP{alpha} mRNA and repress the promoter activity of the C/EBP{alpha} gene, whereas increase ATF3 mRNA, suggesting that ATF3 may contribute to the inhibition of adipocyte differentiation in hypoxia through downregulation of C/EBP{alpha} expression. Collectively, these results demonstrate that ATF3 represses the C/EBP{alpha} gene, resulting in inhibition of adipocyte differentiation, and thus plays a role in hypoxia-mediated inhibition

  8. Rescue of Glaucomatous Neurodegeneration by Differentially Modulating Neuronal Endoplasmic Reticulum Stress Molecules

    PubMed Central

    Yang, Liu; Li, Shaohua; Miao, Linqing; Huang, Haoliang; Liang, Feisi; Teng, Xiuyin; Xu, Lin; Wang, Qizhao; Xiao, Weidong; Ridder, William H.; Ferguson, Toby A.; Chen, Dong Feng; Kaufman, Randal J.

    2016-01-01

    Axon injury is an early event in neurodegenerative diseases that often leads to retrograde neuronal cell death and progressive permanent loss of vital neuronal functions. The connection of these two obviously sequential degenerative events, however, is elusive. Deciphering the upstream signals that trigger the neurodegeneration cascades in both neuronal soma and axon would be a key step toward developing the effective neuroprotectants that are greatly needed in the clinic. We showed previously that optic nerve injury-induced neuronal endoplasmic reticulum (ER) stress plays an important role in retinal ganglion cell (RGC) death. Using two in vivo mouse models of optic neuropathies (traumatic optic nerve injury and glaucoma) and adeno-associated virus–mediated RGC-specific gene targeting, we now show that differential manipulation of unfolded protein response pathways in opposite directions—inhibition of eukaryotic translation initiation factor 2α-C/EBP homologous protein and activation of X-box binding protein 1—promotes both RGC axons and somata survival and preserves visual function. Our results indicate that axon injury-induced neuronal ER stress plays an important role in both axon degeneration and neuron soma death. Neuronal ER stress is therefore a promising therapeutic target for glaucoma and potentially other types of neurodegeneration. SIGNIFICANCE STATEMENT Neuron soma and axon degeneration have distinct molecular mechanisms although they are clearly connected after axon injury. We previously demonstrated that axon injury induces neuronal endoplasmic reticulum (ER) stress and that manipulation of ER stress molecules synergistically promotes neuron cell body survival. Here we investigated the possibility that ER stress also plays a role in axon degeneration and whether ER stress modulation preserves neuronal function in neurodegenerative diseases. Our results suggest that neuronal ER stress is a general mechanism of degeneration for both neuronal

  9. LINGO-1 regulates oligodendrocyte differentiation by inhibiting ErbB2 translocation and activation in lipid rafts.

    PubMed

    Lee, Xinhua; Shao, Zhaohui; Sheng, Guoqing; Pepinsky, Blake; Mi, Sha

    2014-05-01

    Oligodendrocyte differentiation is negatively regulated by LINGO-1 and positively regulated by the ErbB2 receptor tyrosine kinase. In wild-type oligodendrocytes, inhibition of ErbB2 blocks differentiation, whereas activation of ErbB2 promotes differentiation. In LINGO-1(-/-) oligodendrocytes, inhibition of ErbB2 blocks oligodendrocyte differentiation; whereas activation of ErbB2 does not enhance differentiation. Biological and biochemical evidence showing that LINGO-1 can directly bind to ErbB2, block ErbB2 translocation into lipid rafts, and inhibit its phosphorylation for activation. The study demonstrates a novel regulatory mechanism of ErbB2 function whereby LINGO-1 suppresses oligodendrocyte differentiation by inhibiting ErbB2 translocation and activation in lipid rafts.

  10. GABAergic and glycinergic inhibition modulate monaural auditory response properties in the avian superior olivary nucleus

    PubMed Central

    Coleman, W. L.; Fischl, M. J.; Weimann, S. R.

    2011-01-01

    The superior olivary nucleus (SON) is the primary source of inhibition in the avian auditory brainstem. While much is known about the role of inhibition at the SON's target nuclei, little is known about how the SON itself processes auditory information or how inhibition modulates these properties. Additionally, the synaptic physiology of inhibitory inputs within the SON has not been described. We investigated these questions using in vivo and in vitro electrophysiological techniques in combination with immunohistochemistry in the chicken, an organism for which the auditory brainstem has otherwise been well characterized. We provide a thorough characterization of monaural response properties in the SON and the influence of inhibitory input in shaping these features. We found that the SON contains a heterogeneous mixture of response patterns to acoustic stimulation and that in most neurons these responses are modulated by both GABAergic and glycinergic inhibitory inputs. Interestingly, many SON neurons tuned to low frequencies have robust phase-locking capability and the precision of this phase locking is enhanced by inhibitory inputs. On the synaptic level, we found that evoked and spontaneous inhibitory postsynaptic currents (IPSCs) within the SON are also mediated by both GABAergic and glycinergic inhibition in all neurons tested. Analysis of spontaneous IPSCs suggests that most SON cells receive a mixture of both purely GABAergic terminals, as well as terminals from which GABA and glycine are coreleased. Evidence for glycinergic signaling within the SON is a novel result that has important implications for understanding inhibitory function in the auditory brainstem. PMID:21368002

  11. GABAergic and glycinergic inhibition modulate monaural auditory response properties in the avian superior olivary nucleus.

    PubMed

    Coleman, W L; Fischl, M J; Weimann, S R; Burger, R M

    2011-05-01

    The superior olivary nucleus (SON) is the primary source of inhibition in the avian auditory brainstem. While much is known about the role of inhibition at the SON's target nuclei, little is known about how the SON itself processes auditory information or how inhibition modulates these properties. Additionally, the synaptic physiology of inhibitory inputs within the SON has not been described. We investigated these questions using in vivo and in vitro electrophysiological techniques in combination with immunohistochemistry in the chicken, an organism for which the auditory brainstem has otherwise been well characterized. We provide a thorough characterization of monaural response properties in the SON and the influence of inhibitory input in shaping these features. We found that the SON contains a heterogeneous mixture of response patterns to acoustic stimulation and that in most neurons these responses are modulated by both GABAergic and glycinergic inhibitory inputs. Interestingly, many SON neurons tuned to low frequencies have robust phase-locking capability and the precision of this phase locking is enhanced by inhibitory inputs. On the synaptic level, we found that evoked and spontaneous inhibitory postsynaptic currents (IPSCs) within the SON are also mediated by both GABAergic and glycinergic inhibition in all neurons tested. Analysis of spontaneous IPSCs suggests that most SON cells receive a mixture of both purely GABAergic terminals, as well as terminals from which GABA and glycine are coreleased. Evidence for glycinergic signaling within the SON is a novel result that has important implications for understanding inhibitory function in the auditory brainstem.

  12. MiR-9 promotes osteoblast differentiation of mesenchymal stem cells by inhibiting DKK1 gene expression.

    PubMed

    Liu, Xiangyun; Xu, Hao; Kou, Jianqiang; Wang, Qianqian; Zheng, Xiujun; Yu, Tengbo

    2016-09-01

    The aim of this study is to investigate the role of miR-9 and its mechanism on the osteoblast differentiation of mesenchymal stem cells. Real-time PCR and western blotting were used to study gene expression. Assay of Alkaline phosphatase activity and alizarin red staining were used to examine osteoblast differentiation. Transfection of miR-9 mimics or lent-shmiR-9 was used to modulate the level of miR-9 in C2C12. Overexpression of miR-9 in C2C12 cells stimulated alkaline phosphatase activity and osteoblast mineralization, as well as the expression of osteoblast marker genes Col I, Ocn and Bsp. Gene silencing of miR-9 in C2C12 resulted in the suppression of alkaline phosphatase activity and osteoblast mineralization, as well as the expression of Col I, Ocn and Bsp. DKK1 mRNA was not affected by miR-9 overexpression, however, DKK1 protein was significantly decreased. Moreover, DKK1 3'-UTR mediated transcriptional luciferase activity was also significantly suppressed by miR-9 overexpression. DKK1 mRNA was not affected by miR-9 gene silencing, however, DKK1 protein was significantly stimulated. Moreover, DKK1 3'-UTR mediated transcriptional luciferase activity was significantly stimulated by miR-9 gene silencing, and suppressed by miR-9 overexpression, however, DKK1 3'-UTR mutant mediated luciferase activity was unaffected. The siRNA derived gene silencing of DKK1 blocked the inhibiting effect of shmiR-9 on the expression of alkaline phosphatase; and blocked the inhibiting effect of shmiR-9 on the expression of ColI, Ocn and Bsp. MiR-9 promotes osteoblast differentiation of mesenchymal cell C2C12 by suppressing the gene expression of DKK1.

  13. Kindlin-2 Modulates the Survival, Differentiation, and Migration of Induced Pluripotent Cell-Derived Mesenchymal Stromal Cells

    PubMed Central

    Eggenschwiler, Reto; Wichmann, Christian; Buhmann, Raymund; Cantz, Tobias

    2017-01-01

    Kindlin-2 is a multidomain intracellular protein that can be recruited to β-integrin domains to activate signaling, initiate transcriptional programs, and bind to E-cadherin. To explore its involvement in cell fate decisions in mesenchymal cells, we studied the effects of Kindlin-2 modification (overexpression/knockdown) in induced pluripotent cell-derived mesenchymal stromal cells (iPSC-MSCs). Kindlin-2 overexpression resulted in increased proliferation and reduced apoptosis of iPSC-MSCs, as well as inhibition of their differentiation towards osteocytes, adipocytes, and chondrocytes. In contrast, siRNA-mediated Kindlin-2 knockdown induced increased apoptosis and increased differentiation response in iPSC-MSCs. The ability of iPSC-MSCs to adhere to VCAM-1/SDF-1α under shear stress and to migrate in a wound scratch assay was significantly increased after Kindlin-2 overexpression. In contrast, inhibition of mixed lymphocyte reaction (MLR) was generally independent of Kindlin-2 modulation in iPSC-MSCs, except for decreased production of interleukin-2 (IL-2) after Kindlin-2 overexpression in iPS-MSCs. Thus, Kindlin-2 upregulates survival, proliferation, stemness, and migration potential in iPSC-MSCs and may therefore be beneficial in optimizing performance of iPSC-MSC in therapies. PMID:28163724

  14. Propolis Inhibits Neurite Outgrowth in Differentiating SH-SY5Y Human Neuroblastoma Cells

    PubMed Central

    Kim, Han Bit; Yoo, Byung Sun

    2016-01-01

    Propolis is a multicomponent, active, complex resinous substance collected by honeybees from a variety of plant sources. We have studied the effect of propolis on neurite outgrowth of SH-SY5Y human neuroblastoma cells induced to differentiate by all-trans-retinoic acid (RA). Propolis, at a concentration of 3 μg/mL, had no significant effect on the viability of differentiating SH-SY5Y cells. However, the neurite outgrowth of the differentiating SH-SY5Y cells treated with propolis (0.3~3 μg/mL) for 48 hr was significantly inhibited in a dose-dependent manner. Treatment of RA-stimulated differentiating SH-SY5Y cells with 0.3 to 3 μg/mL propolis resulted in decreased level of transglutaminase and 43-kDa growth-associated protein (GAP-43) in a dose-dependent manner. The results indicate that propolis is able to inhibit neurite outgrowth of differentiating SH-SY5Y cells. PMID:27437091

  15. Modulation of cortical excitability and interhemispheric inhibition prior to rhythmic unimanual contractions.

    PubMed

    Sharples, Simon A; Kalmar, Jayne M

    2012-09-30

    The objective of this study was to investigate premotor modulation of motor cortical excitability between rhythmic unimanual finger contractions. Applying TMS at rest prior to an anticipated contraction provides a measure of cortical excitability that reflects premotor modulatory drive and is uncontaminated by the alterations in spinal and cortical excitability that occur during muscle activation. We hypothesized that premotor structures contribute to unimanual movement through the modulation of intracortical and interhemispheric inhibitory circuits within the primary motor cortex and that this premotor modulation would be evident at rest between contractions. Thus, we used transcranial magnetic stimulation (TMS) to assess short interval intracortical inhibition (SICI) and interhemispheric inhibition (IHI) in a 500-ms epoch prior to a planned contraction of the right FDI in 10 participants (21.4±1.9 years). These measures of inhibition were made in three different states: (1) at complete rest (with no plan to contract), (2) at rest between rhythmic contractions, and (3) during low level contractions. Cortical excitability was enhanced prior to a contraction and during a contraction compared to at rest (F₂,₁₈=758.3, p<0.001). IHI was also increased prior to a contraction compared to at rest and during a contraction while SICI was only reduced during a contraction (F₂,₃₈=30.3, p<0.001).We used this pre-contraction protocol to investigate the cortical mechanisms of unimanual control. However, this protocol would be a useful tool to investigate any neuromuscular adaptation that may occur as a result of altered premotor modulation of cortical excitability, such as neuromuscular fatigue, training and movement disorders.

  16. Aryl hydrocarbon receptor activation inhibits in vitro differentiation of human monocytes and Langerhans dendritic cells.

    PubMed

    Platzer, Barbara; Richter, Susanne; Kneidinger, Doris; Waltenberger, Darina; Woisetschläger, Maximilian; Strobl, Herbert

    2009-07-01

    The transcription factor aryl hydrocarbon receptor (AhR) represents a promising therapeutic target in allergy and autoimmunity. AhR signaling induced by the newly described ligand VAF347 inhibits allergic lung inflammation as well as suppresses pancreatic islet allograft rejection. These effects are likely mediated via alterations in dendritic cell (DC) function. Moreover, VAF347 induces tolerogenic DCs. Langerhans cells (LCs) are immediate targets of exogenous AhR ligands at epithelial surfaces; how they respond to AhR ligands remained undefined. We studied AhR expression and function in human LCs and myelopoietic cell subsets using a lineage differentiation and gene transduction model of human CD34(+) hematopoietic progenitors. We found that AhR is highly regulated during myeloid subset differentiation. LCs expressed highest AhR levels followed by monocytes. Conversely, neutrophil granulocytes lacked AhR expression. AhR ligands including VAF347 arrested the differentiation of monocytes and LCs at an early precursor cell stage, whereas progenitor cell expansion or granulopoiesis remained unimpaired. AhR expression was coregulated with the transcription factor PU.1 during myeloid subset differentiation. VAF347 inhibited PU.1 induction during initial monocytic differentiation, and ectopic PU.1 restored monocyte and LC generation in the presence of this compound. AhR ligands failed to interfere with cytokine receptor signaling during LC differentiation and failed to impair LC activation/maturation. VAF347-mediated antiproliferative effect on precursors undergoing LC lineage differentiation occurred in a clinically applicable serum-free culture model and was not accompanied by apoptosis induction. In conclusion, AhR agonist signaling interferes with transcriptional processes leading to monocyte/DC lineage commitment of human myeloid progenitor cells.

  17. Serine dipeptide lipids of Porphyromonas gingivalis inhibit osteoblast differentiation: Relationship to Toll-like receptor 2.

    PubMed

    Wang, Yu-Hsiung; Nemati, Reza; Anstadt, Emily; Liu, Yaling; Son, Young; Zhu, Qiang; Yao, Xudong; Clark, Robert B; Rowe, David W; Nichols, Frank C

    2015-12-01

    Porphyromonas gingivalis is a periodontal pathogen strongly associated with loss of attachment and supporting bone for teeth. We have previously shown that the total lipid extract of P. gingivalis inhibits osteoblast differentiation through engagement of Toll-like receptor 2 (TLR2) and that serine dipeptide lipids of P. gingivalis engage both mouse and human TLR2. The purpose of the present investigation was to determine whether these serine lipids inhibit osteoblast differentiation in vitro and in vivo and whether TLR2 engagement is involved. Osteoblasts were obtained from calvaria of wild type or TLR2 knockout mouse pups that also express the Col2.3GFP transgene. Two classes of serine dipeptide lipids, termed Lipid 654 and Lipid 430, were tested. Osteoblast differentiation was monitored by cell GFP fluorescence and osteoblast gene expression and osteoblast function was monitored as von Kossa stained mineral deposits. Osteoblast differentiation and function were evaluated in calvarial cell cultures maintained for 21 days. Lipid 654 significantly inhibited GFP expression, osteoblast gene expression and mineral nodule formation and this inhibition was dependent on TLR2 engagement. Lipid 430 also significantly inhibited GFP expression, osteoblast gene expression and mineral nodule formation but these effects were only partially attributed to engagement of TLR2. More importantly, Lipid 430 stimulated TNF-α and RANKL gene expression in wild type cells but not in TLR2 knockout cells. Finally, osteoblast cultures were observed to hydrolyze Lipid 654 to Lipid 430 and this likely occurs through elevated PLA2 activity in the cultured cells. In conclusion, our results show that serine dipeptide lipids of P. gingivalis inhibit osteoblast differentiation and function at least in part through engagement of TLR2. The Lipid 430 serine class also increased the expression of genes that could increase osteoclast activity. We conclude that Lipid 654 and Lipid 430 have the potential

  18. Spectrally-efficient differential turbo-coded modulation for multi-gigabit satellite links

    NASA Astrophysics Data System (ADS)

    Tabor, B. H.; Sacchi, C.; Schlegel, C.

    Efficient exploitation of the wide bandwidth available in the EHF (extremely high frequency) domain will be a main pillar for the development of future-generation terabit satellite networks. State-of-the-art systems use spectrally-efficient coded modulations, which are based on coherent demodulation that requires the use of complex and expensive analog PLL circuitry, which are vulnerable to high Doppler shifts and phase noise, the latter, being a significant impairment in the W-band. The latest trends in digital communications are to use fully digital receivers. Therefore, we consider a novel modulation method based on differential turbo-coded modulation and A-Posteriori-Probability (APP) channel estimation for application in multi-gigabit W-band satellite links. The proposed scheme utilizes the combination of an outer 2/3 binary parity channel code and differential 8-PSK modulation, similar to a binary repeat-accumulate serial turbo coding. The turbo-demodulator uses a double-spread interleaver and Log-MAP decoding performed on the 8-PSK trellis. Counteracting channel impairments and frequency drifts is primarily accomplished by APP channel estimation which is integrated into the differential demodulator, and consists of a simple smoothing filter. Preliminary results have shown a robust behavior of the system, achieving high link availability.

  19. Identification of small-molecule modulators of mouse SVZ progenitor cell proliferation and differentiation through high-throughput screening.

    PubMed

    Liu, Yaping; Lacson, Raul; Cassaday, Jason; Ross, David A; Kreamer, Anthony; Hudak, Edward; Peltier, Richard; McLaren, Donna; Muñoz-Sanjuan, Ignacio; Santini, Francesca; Strulovici, Berta; Ferrer, Marc

    2009-04-01

    Adult mouse subventricular zone (SVZ) neural stem/progenitor cells are multipotent self-renewing cells that retain the capacity to generate the major cell types of the central nervous system in vitro and in vivo. The relative ease of expanding SVZ cells in culture as neurospheres makes them an ideal model for carrying out large-scale screening to identify compounds that regulate neural progenitor cell proliferation and differentiation. The authors have developed an adenosine triphosphate-based cell proliferation assay using adult SVZ cells to identify small molecules that activate or inhibit progenitor cell proliferation. This assay was miniaturized to a 1536-well format for high-throughput screening (HTS) of >1 million small-molecule compounds, and 325 and 581 compounds were confirmed as potential inducers of SVZ cell proliferation and differentiation, respectively. A number of these compounds were identified as having a selective proliferative and differentiation effect on SVZ cells versus mouse Neuro2a neuroblastoma cells. These compounds can potentially be useful pharmacological tools to modulate resident stem cells and neurogenesis in the adult brain. This study represents a novel application of primary somatic stem cells in the HTS of a large-scale compound library.

  20. The Novel Small Leucine-rich Protein Chondroadherin-like (CHADL) Is Expressed in Cartilage and Modulates Chondrocyte Differentiation*

    PubMed Central

    Tillgren, Viveka; Ho, James C. S.; Önnerfjord, Patrik; Kalamajski, Sebastian

    2015-01-01

    The constitution and biophysical properties of extracellular matrices can dramatically influence cellular phenotype during development, homeostasis, or pathogenesis. These effects can be signaled through a differentially regulated assembly of collagen fibrils, orchestrated by a family of collagen-associated small leucine-rich proteins (SLRPs). In this report, we describe the tissue-specific expression and function of a previously uncharacterized SLRP, chondroadherin-like (CHADL). We developed antibodies against CHADL and, by immunohistochemistry, detected CHADL expression mainly in skeletal tissues, particularly in fetal cartilage and in the pericellular space of adult chondrocytes. In situ hybridizations and immunoblots on tissue lysates confirmed this tissue-specific expression pattern. Recombinant CHADL bound collagen in cell culture and inhibited in vitro collagen fibrillogenesis. After Chadl shRNA knockdown, chondrogenic ATDC5 cells increased their differentiation, indicated by increased transcript levels of Sox9, Ihh, Col2a1, and Col10a1. The knockdown increased collagen II and aggrecan deposition in the cell layers. Microarray analysis of the knockdown samples suggested collagen receptor-related changes, although other upstream effects could not be excluded. Together, our data indicate that the novel SLRP CHADL is expressed in cartilaginous tissues, influences collagen fibrillogenesis, and modulates chondrocyte differentiation. CHADL appears to have a negative regulatory role, possibly ensuring the formation of a stable extracellular matrix. PMID:25451920

  1. SHARP1/DEC2 inhibits adipogenic differentiation by regulating the activity of C/EBP.

    PubMed

    Gulbagci, Neriman Tuba; Li, Li; Ling, Belinda; Gopinadhan, Suma; Walsh, Martin; Rossner, Moritz; Nave, Klaus-Armin; Taneja, Reshma

    2009-01-01

    SHARP1, a basic helix-loop-helix transcription factor, is expressed in many cell types; however, the mechanisms by which it regulates cellular differentiation remain largely unknown. Here, we show that SHARP1 negatively regulates adipogenesis. Although expression of the early marker CCAAT/enhancer binding protein beta (C/EBPbeta) is not altered, its crucial downstream targets C/EBPalpha and peroxisome proliferator-activated receptor gamma (PPARgamma) are downregulated by SHARP1. Protein interaction studies confirm that SHARP1 interacts with and inhibits the transcriptional activity of both C/EBPbeta and C/EBPalpha, and enhances the association of C/EBPbeta with histone deacetylase 1 (HDAC1). Consistently, in SHARP1-expressing cells, HDAC1 and the histone methyltransferase G9a are retained at the C/EBP regulatory sites on the C/EBPalpha and PPARgamma2 promoters during differentiation, resulting in inhibition of their expression. Interestingly, treatment with troglitazone results in displacement of HDAC1 and G9a, and rescues the differentiation defect of SHARP1-overexpressing cells. Our data indicate that SHARP1 inhibits adipogenesis through the regulation of C/EBP activity, which is essential for PPARgamma-ligand-dependent displacement of co-repressors from adipogenic promoters.

  2. Up-regulated miR-145 Expression Inhibits Porcine Preadipocytes Differentiation by Targeting IRS1

    PubMed Central

    Guo, Yunxue; Chen, Yaosheng; Zhang, Yun; Zhang, Yue; Chen, Luxi; Mo, Delin

    2012-01-01

    Generally, most miRNAs that were up-regulated during differentiation promoted adipogenesis, but our research indicated that up-regulation of miR-145 in porcine preadipocytes did not promote but inhibit adipogenesis. In this study, miR-145 was significantly up-regulated during porcine dedifferentiated fat (DFAT) cells differentiation. In miR-145 overexpressed DFAT cells, adipogenesis was inhibited and triglycerides accumulation was decreased after hormone stimulation (P<0.05). Furthermore, up-regulation of miR-145 expression repressed induction of mRNA levels of adipogenic markers, such as CCAAT/enhancer-binding protein α (C/EBPα), and peroxisome proliferator-activated receptor γ2 (PPARγ2). These effects caused by miR-145 overexpression were mediated by Insulin receptor substrate 1 (IRS1) as a mechanism. These data suggested that induced miR-145 expression during differentiation could inhibit adipogenesis by targeting IRS1, and miR-145 may be novel agent for adipose tissue engineering. PMID:23197937

  3. Up-regulated miR-145 expression inhibits porcine preadipocytes differentiation by targeting IRS1.

    PubMed

    Guo, Yunxue; Chen, Yaosheng; Zhang, Yun; Zhang, Yue; Chen, Luxi; Mo, Delin

    2012-01-01

    Generally, most miRNAs that were up-regulated during differentiation promoted adipogenesis, but our research indicated that up-regulation of miR-145 in porcine preadipocytes did not promote but inhibit adipogenesis. In this study, miR-145 was significantly up-regulated during porcine dedifferentiated fat (DFAT) cells differentiation. In miR-145 overexpressed DFAT cells, adipogenesis was inhibited and triglycerides accumulation was decreased after hormone stimulation (P<0.05). Furthermore, up-regulation of miR-145 expression repressed induction of mRNA levels of adipogenic markers, such as CCAAT/enhancer-binding protein α (C/EBPα), and peroxisome proliferator-activated receptor γ2 (PPARγ2). These effects caused by miR-145 overexpression were mediated by Insulin receptor substrate 1 (IRS1) as a mechanism. These data suggested that induced miR-145 expression during differentiation could inhibit adipogenesis by targeting IRS1, and miR-145 may be novel agent for adipose tissue engineering.

  4. Inhibiting MDSC differentiation from bone marrow with phytochemical polyacetylenes drastically impairs tumor metastasis.

    PubMed

    Wei, Wen-Chi; Lin, Sheng-Yen; Lan, Chun-Wen; Huang, Yu-Chen; Lin, Chih-Yu; Hsiao, Pei-Wen; Chen, Yet-Ran; Yang, Wen-Chin; Yang, Ning-Sun

    2016-11-18

    Myeloid-derived suppressor cells (MDSCs) are implicated in the promotion of tumor metastasis by protecting metastatic cancerous cells from immune surveillance and have thus been suggested as novel targets for cancer therapy. We demonstrate here that oral feeding with polyacetylenic glycosides (BP-E-F1) from the medicinal plant Bidens pilosa effectively suppresses tumor metastasis and inhibits tumor-induced accumulation of granulocytic (g) MDSCs, but does not result in body weight loss in a mouse mammary tumor-resection model. BP-E-F1 is further demonstrated to exert its anti-metastasis activity through inhibiting the differentiation and function of gMDSCs. Pharmacokinetic and mechanistic studies reveal that BP-E-F1 suppresses the differentiation of gMDSCs via the inhibition of a tumor-derived, G-CSF-induced signaling pathway in bone marrow cells of test mice. Taken together, our findings suggest that specific plant polyacetylenic glycosides that target gMDSC differentiation by communicating with bone marrow cells may hence be seriously considered for potential application as botanical drugs against metastatic cancers.

  5. Inhibiting MDSC differentiation from bone marrow with phytochemical polyacetylenes drastically impairs tumor metastasis

    PubMed Central

    Wei, Wen-Chi; Lin, Sheng-Yen; Lan, Chun-Wen; Huang, Yu-Chen; Lin, Chih-Yu; Hsiao, Pei-Wen; Chen, Yet-Ran; Yang, Wen-Chin; Yang, Ning-Sun

    2016-01-01

    Myeloid-derived suppressor cells (MDSCs) are implicated in the promotion of tumor metastasis by protecting metastatic cancerous cells from immune surveillance and have thus been suggested as novel targets for cancer therapy. We demonstrate here that oral feeding with polyacetylenic glycosides (BP-E-F1) from the medicinal plant Bidens pilosa effectively suppresses tumor metastasis and inhibits tumor-induced accumulation of granulocytic (g) MDSCs, but does not result in body weight loss in a mouse mammary tumor-resection model. BP-E-F1 is further demonstrated to exert its anti-metastasis activity through inhibiting the differentiation and function of gMDSCs. Pharmacokinetic and mechanistic studies reveal that BP-E-F1 suppresses the differentiation of gMDSCs via the inhibition of a tumor-derived, G-CSF-induced signaling pathway in bone marrow cells of test mice. Taken together, our findings suggest that specific plant polyacetylenic glycosides that target gMDSC differentiation by communicating with bone marrow cells may hence be seriously considered for potential application as botanical drugs against metastatic cancers. PMID:27857157

  6. CaMKK2 Suppresses Muscle Regeneration through the Inhibition of Myoblast Proliferation and Differentiation

    PubMed Central

    Ye, Cheng; Zhang, Duo; Zhao, Lei; Li, Yan; Yao, Xiaohan; Wang, Hui; Zhang, Shengjie; Liu, Wei; Cao, Hongchao; Yu, Shuxian; Wang, Yucheng; Jiang, Jingjing; Wang, Hui; Li, Xihua; Ying, Hao

    2016-01-01

    Skeletal muscle has a major role in locomotion and muscle disorders are associated with poor regenerative efficiency. Therefore, a deeper understanding of muscle regeneration is needed to provide a new insight for new therapies. CaMKK2 plays a role in the calcium/calmodulin-dependent kinase cascade; however, its role in skeletal muscle remains unknown. Here, we found that CaMKK2 expression levels were altered under physiological and pathological conditions including postnatal myogensis, freeze or cardiotoxin-induced muscle regeneration, and Duchenne muscular dystrophy. Overexpression of CaMKK2 suppressed C2C12 myoblast proliferation and differentiation, while inhibition of CaMKK2 had opposite effect. We also found that CaMKK2 is able to activate AMPK in C2C12 myocytes. Inhibition of AMPK could attenuate the effect of CaMKK2 overexpression, while AMPK agonist could abrogate the effect of CaMKK2 knockdown on C2C12 cell differentiation and proliferation. These results suggest that CaMKK2 functions as an AMPK kinase in muscle cells and AMPK mediates the effect of CaMKK2 on myoblast proliferation and differentiation. Our data also indicate that CaMKK2 might inhibit myoblast proliferation through AMPK-mediated cell cycle arrest by inducing cdc2-Tyr15 phosphorylation and repress differentiation through affecting PGC1α transcription. Lastly, we show that overexpressing CaMKK2 in the muscle of mice via electroporation impaired the muscle regeneration during freeze-induced injury, indicating that CaMKK2 could serve as a potential target to treat patients with muscle injury or myopathies. Together, our study reveals a new role for CaMKK2 as a negative regulator of myoblast differentiation and proliferation and sheds new light on the molecular regulation of muscle regeneration. PMID:27783047

  7. Paracrine Secreted Frizzled-Related Protein 4 Inhibits Melanocytes Differentiation in Hair Follicle

    PubMed Central

    Guo, Haiying; Lei, Mingxing; Li, Yuhong; Liu, Yingxin; Tang, Yinhong; Xing, Yizhan; Deng, Fang

    2017-01-01

    Wnt signaling plays crucial role in regulating melanocyte stem cells/melanocyte differentiation in the hair follicle. However, how the Wnt signaling is balanced to be overactivated to control follicular melanocytes behavior remains unknown. Here, by using immunofluorescence staining, we showed that secreted frizzled-related protein 4 (sFRP4) is preferentially expressed in the skin epidermal cells rather than in melanocytes. By overexpression of sFRP4 in skin cells in vivo and in vitro, we found that sFRP4 attenuates activation of Wnt signaling, resulting in decrease of melanocytes differentiation in the regenerating hair follicle. Our findings unveiled a new regulator that involves modulating melanocytes differentiation through a paracrine mechanism in hair follicle, supplying a hope for potential therapeutic application to treat skin pigmentation disorders. PMID:28337220

  8. Expression of osterix inhibits bone morphogenetic protein-induced chondrogenic differentiation of mesenchymal progenitor cells.

    PubMed

    Tominaga, Hiroyuki; Maeda, Shingo; Miyoshi, Hiroyuki; Miyazono, Kohei; Komiya, Setsuro; Imamura, Takeshi

    2009-01-01

    Osteoblasts and chondrocytes arise from common bipotential mesenchymal progenitor cells. Although the differentiation of these two cell lineages can be induced by treatment with bone morphogenetic proteins (BMPs), the responses of mesenchymal progenitors to BMP differ from cell line to cell line. Here we demonstrate that C3H/10T1/2 cells preferred chondrogenic differentiation, primary bone marrow stroma cells (MSCs) tended to convert to osteoblasts, and ST-2 cells differentiated into both the osteoblastic and chondrocytic lineages simultaneously, suggesting that a molecular switch functions to select cell fate. Osterix, the secondary master regulator of osteoblastogenesis, was induced by BMP at high and low levels in MSCs and ST-2 cells, respectively; in contrast, C3H/10T1/2 cells demonstrated only faint expression. As osterix has been suggested as a negative regulator of chondrogenesis, we hypothesized that the intense chondrocyte differentiation of C3H/10T1/2 cells may have resulted from an absence of osterix. We therefore restored osterix gene expression in C3H/10T1/2 cells using an adenovirus vector. Following BMP treatment, infection with an osterix-encoding virus dramatically inhibited the chondrocytic differentiation of C3H/10T1/2 cells, resulting instead in prominent osteoblast differentiation. These results indicate the chondrogenic potential of C3H/10T1/2 cells was abrogated by osterix expression. Chondrocyte differentiation of MSCs, however, was not enhanced by silencing the osterix gene using lentivirus-mediated shRNA, despite successful suppression of osteoblast differentiation. These results suggest that the low levels of osterix expression remaining after knockdown are sufficient to block chondrogenesis, whereas higher expression may be required to promote osteoblastic differentiation.

  9. Berberine increases expression of GATA-2 and GATA-3 during inhibition of adipocyte differentiation.

    PubMed

    Hu, Y; Davies, G E

    2009-09-01

    It is known that a number of transcription factors are key regulators in the complex process of adipocyte differentiation including peroxisome proliferator activated receptor gamma (PPARgamma) and the CCAAT enhancer binding protein alpha (C/EBPalpha). Studies have demonstrated that in pre-adipocyte 3T3-L1 cells constitutive expression of the DNA binding proteins GATA-2 and GATA-3 results in protein/protein interactions with C/EBPalpha resulting in down regulation of PPARgamma and subsequent suppressed adipocyte differentiation with cells trapped at the pre-adipocyte stage. Thus it appears that GATA-2 and GATA-3 are of critical importance in regulating adipocyte differentiation through molecular interactions with PPARgamma and C/EBPalpha. Recent reports suggest that berberine, an isoquinoline derivative alkaloid isolated from many medicinal herbs prevents differentiation of 3T3-L1 cells via a down regulation of PPARgamma and C/EBPalpha expression. The aim of this study was to determine the effect of berberine on GATA-2 and 3 gene and protein expression levels during differentiation of 3T3-L1 cells. MTT (Methylthiazolyldiphenyl-tetrazolium bromide) was used to detect the cytotoxic effects of berberine on the viability of 3T3-L1 cells during proliferation and differentiation. Differentiation of 3T3-L1 cells was monitored by Oil Red O staining and RT-PCR of PPARgamma and C/EBPalpha and the expression of GATA-2 and 3 was determined by RT-PCR and Western Blot. Results show that following treatment with 8microM berberine the mRNA and protein expression levels of GATA-2 and 3 were elevated and accompanied by inhibited adipocyte differentiation. These results may lead to the use of berberine to target the induction of specific genes such as GATA-2 and GATA-3 which affect adipocyte differentiation.

  10. Atg5 and Ambra1 differentially modulate neurogenesis in neural stem cells.

    PubMed

    Vázquez, Patricia; Arroba, Ana I; Cecconi, Francesco; de la Rosa, Enrique J; Boya, Patricia; de Pablo, Flora

    2012-02-01

    Neuroepithelial cells undergoing differentiation efficiently remodel their cytoskeleton and shape in an energy-consuming process. The capacity of autophagy to recycle cellular components and provide energy could fulfill these requirements, thus supporting differentiation. However, little is known regarding the role of basal autophagy in neural differentiation. Here we report an increase in the expression of the autophagy genes Atg7, Becn1, Ambra1 and LC3 in vivo in the mouse embryonic olfactory bulb (OB) during the initial period of neuronal differentiation at E15.5, along with a parallel increase in neuronal markers. In addition, we observed an increase in LC3 lipidation and autophagic flux during neuronal differentiation in cultured OB-derived stem/progenitor cells. Pharmacological inhibition of autophagy with 3-MA or wortmannin markedly decreased neurogenesis. These observations were supported by similar findings in two autophagy-deficient genetic models. In Ambra1 loss-of-function homozygous mice (gt/gt) the expression of several neural markers was decreased in the OB at E13.5 in vivo. In vitro, Ambra1 haploinsufficient cells developed as small neurospheres with an impaired capacity for neuronal generation. The addition of methylpyruvate during stem/progenitor cell differentiation in culture largely reversed the inhibition of neurogenesis induced by either 3-MA or Ambra1 haploinsufficiency, suggesting that neural stem/progenitor cells activate autophagy to fulfill their high energy demands. Further supporting the role of autophagy for neuronal differentiation Atg5-null OB cells differentiating in culture displayed decreased TuJ1 levels and lower number of cells with neurites. These results reveal new roles for autophagy-related molecules Atg5 and Ambra1 during early neuronal differentiation of stem/progenitor cells.

  11. Antrodia cinnamomea Extract Inhibits Th17 Cell Differentiation and Ameliorates Imiquimod-Induced Psoriasiform Skin Inflammation.

    PubMed

    Li, Ming-Han; Wu, Hsin-Chieh; Yao, Hsin-Jan; Lin, Chi-Chen; Wen, Shu-Fang; Pan, I-Horng

    2015-01-01

    Antrodia cinnamomea (A. cinnamomea) is a Chinese medicinal herb that possesses a broad range of bioactivities, including anti-inflammation. Given that the proinflammatory cytokine IL-17 plays a critical role in the pathogenesis of autoimmune diseases, we investigated whether A. cinnamomea could inhibit the development of Th17 cells, the main producer of IL-17, and exhibit therapeutic effects on an animal model of psoriasis. We found that A. cinnamomea extract (AC) inhibited the differentiation of Th17 cells as well as the production of IL-17A, IL-21, and IL-22 from these cells. This effect was associated with the inhibition of STAT3 phosphorylation and RORγt expression. Notably, the oral administration of AC reduced psoriasis-like inflammation in imiquimod-mediated dermal damage, repressed the expression of IL-17A, IL-22, and TNF-α in skin lesions, and decreased the infiltration of CD4⁺ T cells, CD8⁺ T cells, and neutrophils into the dermis. Finally, serum levels of IL-17A were decreased in AC-treated mice with psoriasis-like skin inflammation. Taken together, these findings indicate that AC inhibits Th17 cell differentiation, suggesting a role for A. cinnamomea in the treatment of psoriasis and other Th17 cell-mediated inflammatory diseases.

  12. Interleukin-4 Inhibits Regulatory T Cell Differentiation through Regulating CD103+ Dendritic Cells

    PubMed Central

    Tu, Lei; Chen, Jie; Zhang, Hongwei; Duan, Lihua

    2017-01-01

    CD103+ dendritic cells (DCs) have been shown to play a crucial role in the pathogenesis of inflammatory bowel diseases (IBDs) through educating regulatory T (Treg) cells differentiation. However, the mechanism of CD103+ DCs subsets differentiation remains elusive. Interleukin (IL)-4 is a pleiotropic cytokine that is upregulated in certain types of inflammation, including IBDs and especially ulcerative colitis. However, the precise role of IL-4 in the differentiation of CD103+ DCs subpopulation remains unknown. In this study, we observed a repressive role of IL-4 on the CD103+ DCs differentiation in both mouse and human. High-dose IL-4 inhibited the CD103+ DC differentiation. In comparison to CD103− DCs, CD103+ DCs expressed high levels of the co-stimulatory molecules and indoleamine 2,3-dioxygenase (IDO). Interestingly, IL-4 diminished IDO expression on DCs in a dose-dependent manner. Besides, high-dose IL-4-induced bone marrow-derived DCs, and monocyte-derived DCs revealed mature DCs profiles, characterized by increased co-stimulatory molecules and decreased pinocytotic function. Furthermore, DCs generated under low concentrations of IL-4 favored Treg cells differentiation, which depend on IDO produced by CD103+ DCs. Consistently, IL-4 also reduced the frequency of CD103+ DC in vivo. Thus, we here demonstrated that the cytokine IL-4 involved in certain types of inflammatory diseases by orchestrating the functional phenotype of CD103+ DCs subsets. PMID:28316599

  13. Skeletal unloading inhibits the in vitro proliferation and differentiation of rat osteoprogenitor cells

    NASA Technical Reports Server (NTRS)

    Kostenuik, P. J.; Halloran, B. P.; Morey-Holton, E. R.; Bikle, D. D.

    1997-01-01

    Loss of weight bearing in the growing rat decreases bone formation, osteoblast numbers, and bone maturation in unloaded bones. These responses suggest an impairment of osteoblast proliferation and differentiation. To test this assumption, we assessed the effects of skeletal unloading using an in vitro model of osteoprogenitor cell differentiation. Rats were hindlimb elevated for 0 (control), 2, or 5 days, after which their tibial bone marrow stromal cells (BMSCs) were harvested and cultured. Five days of hindlimb elevation led to significant decreases in proliferation, alkaline phosphatase (AP) enzyme activity, and mineralization of BMSC cultures. Differentiation of BMSCs was analyzed by quantitative competitive polymerase chain reaction of cDNA after 10, 15, 20, and 28 days of culture. cDNA pools were analyzed for the expression of c-fos (an index of proliferation), AP (an index of early osteoblast differentiation), and osteocalcin (a marker of late differentiation). BMSCs from 5-day unloaded rats expressed 50% less c-fos, 61% more AP, and 35% less osteocalcin mRNA compared with controls. These data demonstrate that cultured osteoprogenitor cells retain a memory of their in vivo loading history and indicate that skeletal unloading inhibits proliferation and differentiation of osteoprogenitor cells in vitro.

  14. Schisandrae fructus enhances myogenic differentiation and inhibits atrophy through protein synthesis in human myotubes

    PubMed Central

    Kim, Cy Hyun; Shin, Jin-Hong; Hwang, Sung Jun; Choi, Yung Hyun; Kim, Dae-Seong; Kim, Cheol Min

    2016-01-01

    Schisandrae fructus (SF) has recently been reported to increase skeletal muscle mass and inhibit atrophy in mice. We investigated the effect of SF extract on human myotube differentiation and its acting pathway. Various concentrations (0.1–10 μg/mL) of SF extract were applied on human skeletal muscle cells in vitro. Myotube area and fusion index were measured to quantify myotube differentiation. The maximum effect was observed at 0.5 μg/mL of SF extract, enhancing differentiation up to 1.4-fold in fusion index and 1.6-fold in myotube area at 8 days after induction of differentiation compared to control. Phosphorylation of eukaryotic translation initiation factor 4E-binding protein 1 and 70 kDa ribosomal protein S6 kinase, which initiate translation as downstream of mammalian target of rapamycin pathway, was upregulated in early phases of differentiation after SF treatment. SF also attenuated dexamethasone-induced atrophy. In conclusion, we show that SF augments myogenic differentiation and attenuates atrophy by increasing protein synthesis through mammalian target of rapamycin/70 kDa ribosomal protein S6 kinase and eukaryotic translation initiation factor 4E-binding protein 1 signaling pathway in human myotubes. SF can be a useful natural dietary supplement in increasing skeletal muscle mass, especially in the aged with sarcopenia and the patients with disuse atrophy. PMID:27330287

  15. Aberrant Neuronal Differentiation and Inhibition of Dendrite Outgrowth Resulting from Endoplasmic Reticulum Stress

    PubMed Central

    Kawada, Koichi; Iekumo, Takaaki; Saito, Ryo; Kaneko, Masayuki; Mimori, Seisuke; Nomura, Yasuyuki; Okuma, Yasunobu

    2014-01-01

    Neural stem cells (NSCs) play an essential role in development of the central nervous system. Endoplasmic reticulum (ER) stress induces neuronal death. After neuronal death, neurogenesis is generally enhanced to repair the damaged regions. However, it is unclear whether ER stress directly affects neurogenesis-related processes such as neuronal differentiation and dendrite outgrowth. We evaluated whether neuronal differentiation and dendrite outgrowth were regulated by HRD1, a ubiquitin ligase that was induced under mild conditions of tunicamycin-induced ER stress. Neurons were differentiated from mouse embryonic carcinoma P19 cells by using retinoic acid. The differentiated cells were cultured for 8 days with or without tunicamycin and HRD1 knockdown. The ER stressor led to markedly increased levels of ER stress. ER stress increased the expression levels of neuronal marker βIII-tubulin in 8-day-differentiated cells. However, the neurites of dendrite marker microtubule-associated protein-2 (MAP-2)-positive cells appeared to retract in response to ER stress. Moreover, ER stress markedly reduced the dendrite length and MAP-2 expression levels, whereas it did not affect the number of surviving mature neurons. In contrast, HRD1 knockdown abolished the changes in expression of proteins such as βIII-tubulin and MAP-2. These results suggested that ER stress caused aberrant neuronal differentiation from NSCs followed by the inhibition of neurite outgrowth. These events may be mediated by increased HRD1 expression. PMID:24723324

  16. Polar/apolar compounds induce leukemia cell differentiation by modulating cell-surface potential.

    PubMed Central

    Arcangeli, A; Carlà, M; Del Bene, M R; Becchetti, A; Wanke, E; Olivotto, M

    1993-01-01

    The mechanism of action of polar/apolar inducers of cell differentiation, such as dimethyl sulfoxide and hexamethylene-bisacetamide, is still obscure. In this paper evidence is provided that their effects on murine erythroleukemia cells are modulated by various extracellular cations as a precise function of the cation effects on membrane surface potential. The interfacial effects of the inducers were directly measured on the charged electrode, showing that both dimethyl sulfoxide and hexamethylene-bisacetamide, at the effective concentrations for cell differentiation and within the physiological range of charge density, adsorb at the charged surface and produce a potential shift. A linear correlation was found between this shift and the inducer effects on cell differentiation. Besides offering a different interpretation of the mechanism of action of the inducers, these findings indicate that surface potential has a signaling function. They may also be relevant to cancer treatments based on tumor-cell commitment to terminal differentiation. Images Fig. 1 PMID:8516337

  17. Individual strains of Lactobacillus paracasei differentially inhibit human basophil and mouse mast cell activation

    PubMed Central

    Cassard, Lydie; Lalanne, Ana Inés; Garault, Peggy; Cotillard, Aurélie; Chervaux, Christian; Wels, Michiel; Smokvina, Tamara

    2016-01-01

    Abstract Introduction The microbiota controls a variety of biological functions, including immunity, and alterations of the microbiota in early life are associated with a higher risk of developing allergies later in life. Several probiotic bacteria, and particularly lactic acid bacteria, were described to reduce both the induction of allergic responses and allergic manifestations. Although specific probiotic strains were used in these studies, their protective effects on allergic responses also might be common for all lactobacilli. Methods To determine whether allergic effector cells inhibition is a common feature of lactobacilli or whether it varies among lactobacilli strains, we compared the ability of 40 strains of the same Lactobacillus paracasei species to inhibit IgE‐dependent mouse mast cell and human basophil activation. Results We uncovered a marked heterogeneity in the inhibitory properties of the 40 Lactobacillus strains tested. These segregated into three to four clusters depending on the intensity of inhibition. Some strains inhibited both mouse mast cell and human basophil activation, others strains inhibited only one cell type and another group induced no inhibition of activation for either cell type. Conclusions Individual Lactobacillus strains of the same species differentially inhibit IgE‐dependent activation of mouse mast cells and human basophils, two cell types that are critical in the onset of allergic manifestations. Although we failed to identify specific bacterial genes associated with inhibition by gene‐trait matching analysis, our findings demonstrate the complexity of the interactions between the microbiota and the host. These results suggest that some L. paracasei strains might be more beneficial in allergies than others strains and provide the bases for a rational screening of lactic acid bacteria strains as next‐generation probiotics in the field of allergy. PMID:27621812

  18. Regulatory T cells inhibit CD34+ cell differentiation into NK cells by blocking their proliferation

    PubMed Central

    Pedroza-Pacheco, Isabela; Shah, Divya; Domogala, Anna; Luevano, Martha; Blundell, Michael; Jackson, Nicola; Thrasher, Adrian; Madrigal, Alejandro; Saudemont, Aurore

    2016-01-01

    Graft versus Host Disease (GvHD) remains one of the main complications after hematopoietic stem cell transplantation (HSCT). Due to their ability to suppress effector cells, regulatory T cells (Tregs) have been proposed as a cellular therapy to prevent GvHD, however they also inhibit the functions of natural killer (NK) cells, key effectors of the Graft versus Leukemia effect. In this study, we have explored whether a Tregs therapy will also impact on NK cell differentiation. Using an in vitro model of hematopoietic stem cell (HSC) differentiation into NK cells, we found that activated Tregs led to a 90% reduction in NK cell numbers when added at the time of commitment to the NK cell lineage. This effect was contact dependent and was reversible upon Tregs depletion. The few NK cells that developed in these cultures were mature and exhibited normal functions. Furthermore, adoptive transfer of activated Tregs in rag-/- γc-/- mice abrogated HSC differentiation into NK cells thus confirming our in vitro findings. Collectively, these results demonstrate for the first time that activated Tregs can inhibit NK cell differentiation from HSC under specific conditions. PMID:26915707

  19. Regulatory T cells inhibit CD34+ cell differentiation into NK cells by blocking their proliferation.

    PubMed

    Pedroza-Pacheco, Isabela; Shah, Divya; Domogala, Anna; Luevano, Martha; Blundell, Michael; Jackson, Nicola; Thrasher, Adrian; Madrigal, Alejandro; Saudemont, Aurore

    2016-02-26

    Graft versus Host Disease (GvHD) remains one of the main complications after hematopoietic stem cell transplantation (HSCT). Due to their ability to suppress effector cells, regulatory T cells (Tregs) have been proposed as a cellular therapy to prevent GvHD, however they also inhibit the functions of natural killer (NK) cells, key effectors of the Graft versus Leukemia effect. In this study, we have explored whether a Tregs therapy will also impact on NK cell differentiation. Using an in vitro model of hematopoietic stem cell (HSC) differentiation into NK cells, we found that activated Tregs led to a 90% reduction in NK cell numbers when added at the time of commitment to the NK cell lineage. This effect was contact dependent and was reversible upon Tregs depletion. The few NK cells that developed in these cultures were mature and exhibited normal functions. Furthermore, adoptive transfer of activated Tregs in rag(-/-) γc(-/-) mice abrogated HSC differentiation into NK cells thus confirming our in vitro findings. Collectively, these results demonstrate for the first time that activated Tregs can inhibit NK cell differentiation from HSC under specific conditions.

  20. Inhibition of β-catenin–TCF1 interaction delays differentiation of mouse embryonic stem cells

    PubMed Central

    Chatterjee, Sujash S.; Saj, Abil; Gocha, Tenzin; Murphy, Matthew; Gonsalves, Foster C.; Zhang, Xiaoqian; Hayward, Penelope; Akgöl Oksuz, Betül; Shen, Steven S.; Madar, Aviv; Martinez Arias, Alfonso

    2015-01-01

    The ability of mouse embryonic stem cells (mESCs) to self-renew or differentiate into various cell lineages is regulated by signaling pathways and a core pluripotency transcriptional network (PTN) comprising Nanog, Oct4, and Sox2. The Wnt/β-catenin pathway promotes pluripotency by alleviating T cell factor TCF3-mediated repression of the PTN. However, it has remained unclear how β-catenin’s function as a transcriptional activator with TCF1 influences mESC fate. Here, we show that TCF1-mediated transcription is up-regulated in differentiating mESCs and that chemical inhibition of β-catenin/TCF1 interaction improves long-term self-renewal and enhances functional pluripotency. Genetic loss of TCF1 inhibited differentiation by delaying exit from pluripotency and conferred a transcriptional profile strikingly reminiscent of self-renewing mESCs with high Nanog expression. Together, our data suggest that β-catenin’s function in regulating mESCs is highly context specific and that its interaction with TCF1 promotes differentiation, further highlighting the need for understanding how its individual protein–protein interactions drive stem cell fate. PMID:26459597

  1. Inhibition of FGF signaling accelerates neural crest cell differentiation of human pluripotent stem cells.

    PubMed

    Jaroonwitchawan, Thiranut; Muangchan, Pattamon; Noisa, Parinya

    2016-12-02

    Neural crest (NC) is a transient population, arising during embryonic development and capable of differentiating into various somatic cells. The defects of neural crest development leads to neurocristopathy. Several signaling pathways were revealed their significance in NC cell specification. Fibroblast growth factor (FGF) is recognized as an important signaling during NC development, for instance Xenopus and avian; however, its contributions in human species are remained elusive. Here we used human pluripotent stem cells (hPSCs) to investigate the consequences of FGF inhibition during NC cell differentiation. The specific-FGF receptor inhibitor, SU5402, was used in this investigation. The inhibition of FGF did not found to affect the proliferation or death of hPSC-derived NC cells, but promoted hPSCs to commit NC cell fate. NC-specific genes, including PAX3, SLUG, and TWIST1, were highly upregulated, while hPSC genes, such as OCT4, and E-CAD, rapidly reduced upon FGF signaling blockage. Noteworthy, TFAP-2α, a marker of migratory NC cells, abundantly presented in SU5402-induced cells. This accelerated NC cell differentiation could be due to the activation of Notch signaling upon the blockage of ERK1/2 phosphorylation, since NICD was increased by SU5402. Altogether, this study proposed the contributions of FGF signaling in controlling human NC cell differentiation from hPSCs, the crosstalk between FGF and Notch, and might imply to the influences of FGF signaling in neurocristophatic diseases.

  2. Orai1 internalization and STIM1 clustering inhibition modulate SOCE inactivation during meiosis.

    PubMed

    Yu, Fang; Sun, Lu; Machaca, Khaled

    2009-10-13

    Store-operated Ca(2+) entry (SOCE) is a ubiquitous Ca(2+) influx pathway activated in response to depletion of intracellular Ca(2+) stores. SOCE is a primary modulator of intracellular Ca(2+) dynamics, which specify cellular responses. Interestingly, SOCE inactivates during M phase but the mechanisms involved remain unclear. SOCE is mediated by clustering of the ER Ca(2+) sensor STIM1 in response to Ca(2+) store depletion, leading to gating of the plasma membrane SOCE channel Orai1. Here we show that SOCE inactivation in meiosis is the result of internalization of Orai1 into an intracellular vesicular compartment and to the inability of STIM1 to cluster in response to store depletion. At rest, Orai1 continuously recycles between the cell membrane and an endosomal compartment. We further show that STIM1-STIM1 interactions are inhibited during meiosis, which appears to mediate the inability of STIM1 to form puncta following store depletion. In contrast, STIM1-Orai1 interactions remain functional during meiosis. Combined, the removal of Orai1 from the cell membrane and STIM1 clustering inhibition effectively uncouple store depletion from SOCE activation in meiosis. Although STIM1 is phosphorylated during meiosis, phosphomimetic and alanine substitution mutations do not modulate STIM1 clustering, arguing that phosphorylation does not mediate STIM1 clustering inhibition during meiosis.

  3. Small‑molecule COH-SR4 inhibits adipocyte differentiation via AMPK activation.

    PubMed

    Figarola, James L; Rahbar, Samuel

    2013-05-01

    Obesity is a chronic metabolic disorder caused by an imbalance between energy intake and expenditure. It is one of the principal causative factors involved in the development of metabolic syndrome and cancer. Inhibition of adipocyte differentiation has often been a target of anti-obesity strategies since obesity is caused not only by hypertrophy but also by adipocyte hyperplasia. In this study, we investigated the effects of COH-SR4, a novel compound with anticancer properties, on the adipogenesis in 3T3-L1 cells. Treatment with COH-SR4 significantly inhibited adipocyte differentiation in a dose-dependent manner. This inhibitory effect mainly occurred at the early phase of differentiation through inhibition of mitotic clonal expansion and cell cycle arrest at the G1/S phase transition. In differentiating adipocytes, COH-SR4 significantly reduced intracellular lipid accumulation and downregulated the expression of key adipogenesis-related transcription factors and lipogenic proteins. COH-SR4 exhibited no cytotoxic effects in 3T3-L1 cells, but indirectly activated AMP-activated protein kinase (AMPK). AMPK activation by COH-SR4 also resulted in the phosphorylation of raptor and tuberous sclerosis protein 2 (TSC2), two proteins involved in the mammalian target of rapamycin (mTOR) signaling pathways. Additionally, COH-SR4 decreased the phosphorylation of p70 kDa ribosomal protein S6 kinase (S6K) and initiation factor 4E (eIF4E) binding protein 1 (4EB‑P1), two downstream effectors of mTOR that regulate protein synthesis. Interestingly, knockdown of AMPKα1/α2 prevented the ability of COH-SR4 to inhibit cell cycle arrest and overall adipogenesis and lipid accumulation in the differentiating 3T3-L1 cells. Taken together, these results suggest that COH-SR4 inhibits 3T3-L1 adipogenesis via AMPK activation. COH-SR4 may be a promising compound for the treatment of obesity and related metabolic disorders.

  4. Differential modulation of ROS signals and other mitochondrial parameters by the antioxidants MitoQ, resveratrol and curcumin in human adipocytes.

    PubMed

    Hirzel, Estelle; Lindinger, Peter W; Maseneni, Swarna; Giese, Maria; Rhein, Véronique Virginie; Eckert, Anne; Hoch, Matthias; Krähenbühl, Stephan; Eberle, Alex N

    2013-10-01

    Mitochondrial reactive oxygen species (ROS) have been demonstrated to play an important role as signaling and regulating molecules in human adipocytes. In order to evaluate the differential modulating roles of antioxidants, we treated human adipocytes differentiated from human bone marrow-derived mesenchymal stem cells with MitoQ, resveratrol and curcumin. The effects on ROS, viability, mitochondrial respiration and intracellular ATP levels were examined. MitoQ lowered both oxidizing and reducing ROS. Resveratrol decreased reducing and curcumin oxidizing radicals only. All three substances slightly decreased state III respiration immediately after addition. After 24 h of treatment, MitoQ inhibited both basal and uncoupled oxygen consumption, whereas curcumin and resveratrol had no effect. Intracellular ATP levels were not altered. This demonstrates that MitoQ, resveratrol and curcumin exert potent modulating effects on ROS signaling in human adipocyte with marginal effects on metabolic parameters.

  5. The role and possible mechanism of lncRNA U90926 in modulating 3T3-L1 preadipocyte differentiation

    PubMed Central

    Chen, J; Liu, Y; Lu, S; Yin, L; Zong, C; Cui, S; Qin, D; Yang, Y; Guan, Q; Li, X; Wang, X

    2017-01-01

    Background: Obesity is a risk factor for metabolic diseases, while preadipocyte differentiation or adipogenesis is closely related to obesity occurrence. Long noncoding RNAs (lncRNAs) are a unique class of transcripts in regulation of a variety of biological processes. Using cDNA microarray, we found lncRNA U90926 is negatively correlated with 3T3-L1 preadipocyte differentiation. Objective: The aim of this study was to explore the role of lncRNA U90926 (lnc-U90926) in adipogenesis and the underlying mechanisms. Methods: Quantitative real-time PCR (qPCR) was performed to determine lnc-U90926 expression in 3T3-L1 preadipocytes, differentiated adipocytes, and in adipose tissues form mice. RNA fluorescent in situ hybridization (FISH) was performed to determine the localization of lnc-U90926 in 3T3-L1 preadipocytes. The effects of lnc-U90926 on 3T3-L1 adipogenesis were analyzed with lentivirus-mediated gain- and loss-of-function experiments. Lipid accumulation was evaluated by oil red O staining; several adipogenesis makers were analyzed by qPCR and western blotting. Dual luciferase assay was applied to explore the transactivation of target genes modulated by lnc-U90926. All measurements were performed at least for three times. Results: Lnc-U90926 expression decreased along the differentiation of 3T3-L1 preadipocytes. In mice, lnc-U90926 is predominantly expressed in adipose tissue. Obese mice have lower lnc-U90926 expression in subcutaneous and visceral adipose tissue than non-obese mice. FISH results showed that lnc-U90926 was mainly located in the cytoplasm. Overexpression lnc-U90926 attenuated 3T3-L1 adipocyte differentiation as evidenced by its ability to inhibit lipid accumulation, to decrease the mRNA levels of peroxisome proliferator-activated receptor gamma 2 (PPARγ2), fatty acid binding protein 4 (FABP4) and adiponectin (AdipoQ) as well as to reduce the protein levels of PPARγ and FABP4 (P<0.05). Knockdown of lnc-U90926 showed opposite effects, which

  6. Cannabidiol Modulates the Immunophenotype and Inhibits the Activation of the Inflammasome in Human Gingival Mesenchymal Stem Cells

    PubMed Central

    Libro, Rosaliana; Scionti, Domenico; Diomede, Francesca; Marchisio, Marco; Grassi, Gianpaolo; Pollastro, Federica; Piattelli, Adriano; Bramanti, Placido; Mazzon, Emanuela; Trubiani, Oriana

    2016-01-01

    Human Gingival Mesenchymal Stem Cells (hGMSCs) are multipotential cells that can expand and differentiate in culture under specific and standardized conditions. In the present study, we have investigated whether in vitro pre-treatment of hGMSCs with Cannabidiol (CBD) can influence their expression profile, improving the therapeutic potential of this cell culture. Following CBD treatment (5 μM) for 24 h, gene expression analysis through Next Generation Sequencing (NGS) has revealed several genes differentially expressed between CBD-treated hGMSCs (CBD-hGMSCs) and control cells (CTR-hGMSCs) that were linked to inflammation and apoptosis. In particular, we have demonstrated that CBD treatment in hGMSCs prevented the activation of the NALP3-inflammasome pathway by suppressing the levels of NALP3, CASP1, and IL18, and in parallel, inhibited apoptosis, as demonstrated by the suppression of Bax. CBD treatment was also able to modulate the expression of the well-known mesenchymal stem cell markers (CD13, CD29, CD73, CD44, CD90, and CD166), and other surface antigens. Specifically, CBD led to the downregulation of genes codifying for antigens involved in the activation of the immune system (CD109, CD151, CD40, CD46, CD59, CD68, CD81, CD82, CD99), while it led to the upregulation of those implicated in the inhibition of the immune responses (CD47, CD55, CD276). In conclusion, the present study will provide a new simple and reproducible method for preconditioning hGMSCs with CBD, before transplantation, as an interesting strategy for improving the hGMSCs molecular phenotype, reducing the risk of immune or inflammatory reactions in the host, and in parallel, for increasing their survival and thus, their long-term therapeutic efficacy. PMID:27932991

  7. Cannabidiol Modulates the Immunophenotype and Inhibits the Activation of the Inflammasome in Human Gingival Mesenchymal Stem Cells.

    PubMed

    Libro, Rosaliana; Scionti, Domenico; Diomede, Francesca; Marchisio, Marco; Grassi, Gianpaolo; Pollastro, Federica; Piattelli, Adriano; Bramanti, Placido; Mazzon, Emanuela; Trubiani, Oriana

    2016-01-01

    Human Gingival Mesenchymal Stem Cells (hGMSCs) are multipotential cells that can expand and differentiate in culture under specific and standardized conditions. In the present study, we have investigated whether in vitro pre-treatment of hGMSCs with Cannabidiol (CBD) can influence their expression profile, improving the therapeutic potential of this cell culture. Following CBD treatment (5 μM) for 24 h, gene expression analysis through Next Generation Sequencing (NGS) has revealed several genes differentially expressed between CBD-treated hGMSCs (CBD-hGMSCs) and control cells (CTR-hGMSCs) that were linked to inflammation and apoptosis. In particular, we have demonstrated that CBD treatment in hGMSCs prevented the activation of the NALP3-inflammasome pathway by suppressing the levels of NALP3, CASP1, and IL18, and in parallel, inhibited apoptosis, as demonstrated by the suppression of Bax. CBD treatment was also able to modulate the expression of the well-known mesenchymal stem cell markers (CD13, CD29, CD73, CD44, CD90, and CD166), and other surface antigens. Specifically, CBD led to the downregulation of genes codifying for antigens involved in the activation of the immune system (CD109, CD151, CD40, CD46, CD59, CD68, CD81, CD82, CD99), while it led to the upregulation of those implicated in the inhibition of the immune responses (CD47, CD55, CD276). In conclusion, the present study will provide a new simple and reproducible method for preconditioning hGMSCs with CBD, before transplantation, as an interesting strategy for improving the hGMSCs molecular phenotype, reducing the risk of immune or inflammatory reactions in the host, and in parallel, for increasing their survival and thus, their long-term therapeutic efficacy.

  8. Hes1 Desynchronizes Differentiation of Pluripotent Cells by Modulating STAT3 Activity

    PubMed Central

    Zhou, Xinzhi; Smith, Andrew JH; Waterhouse, Anna; Blin, Guillaume; Malaguti, Mattias; Lin, Chia-Yi; Osorno, Rodrigo; Chambers, Ian; Lowell, Sally

    2013-01-01

    Robust development of the early embryo may benefit from mechanisms that ensure that not all pluripotent cells differentiate at exactly the same time: such mechanisms would build flexibility into the process of lineage allocation. This idea is supported by the observation that pluripotent stem cells differentiate at different rates in vitro. We use a clonal commitment assay to confirm that pluripotent cells commit to differentiate asynchronously even under uniform differentiation conditions. Stochastic variability in expression of the Notch target gene Hes1 has previously been reported to influence neural versus mesodermal differentiation through modulation of Notch activity. Here we report that Hes1 also has an earlier role to delay exit from the pluripotent state into all lineages. The early function of Hes1 to delay differentiation can be explained by an ability of Hes1 to amplify STAT3 responsiveness in a cell-autonomous manner. Variability in Hes1 expression therefore helps to explain why STAT3 responsiveness varies between individual ES cells, and this in turn helps to explain why pluripotent cells commit to differentiate asynchronously. Stem Cells 2013;31:1511–1522 PMID:23649667

  9. Hes1 desynchronizes differentiation of pluripotent cells by modulating STAT3 activity.

    PubMed

    Zhou, Xinzhi; Smith, Andrew J H; Waterhouse, Anna; Blin, Guillaume; Malaguti, Mattias; Lin, Chia-Yi; Osorno, Rodrigo; Chambers, Ian; Lowell, Sally

    2013-08-01

    Robust development of the early embryo may benefit from mechanisms that ensure that not all pluripotent cells differentiate at exactly the same time: such mechanisms would build flexibility into the process of lineage allocation. This idea is supported by the observation that pluripotent stem cells differentiate at different rates in vitro. We use a clonal commitment assay to confirm that pluripotent cells commit to differentiate asynchronously even under uniform differentiation conditions. Stochastic variability in expression of the Notch target gene Hes1 has previously been reported to influence neural versus mesodermal differentiation through modulation of Notch activity. Here we report that Hes1 also has an earlier role to delay exit from the pluripotent state into all lineages. The early function of Hes1 to delay differentiation can be explained by an ability of Hes1 to amplify STAT3 responsiveness in a cell-autonomous manner. Variability in Hes1 expression therefore helps to explain why STAT3 responsiveness varies between individual ES cells, and this in turn helps to explain why pluripotent cells commit to differentiate asynchronously.

  10. Inhibition of inducible nitric oxide synthase and osteoclastic differentiation by Atractylodis Rhizoma Alba extract

    PubMed Central

    Choi, Sung-Ho; Kim, Sung-Jin

    2014-01-01

    Background: Atractylodis Rhizoma Alba (ARA) has been used in Korean folk medicine for constipation, dizziness, and anticancer agent. In the present study, we performed to test whether the methanolic extract of ARA has antioxidant and antiosteoclastogenesis activity in RAW 264.7 macrophage cells. Materials and Methods: Antioxidant capacities were tested by measuring free radical scavenging activity, nitric oxide (NO) levels, reducing power, and inducible nitric oxide synthase (iNOS) expression in response to lipopolysaccharides (LPS). Antiosteoclastogenesis activity was evaluated by performing tartrate-resistant acid phosphatase assay in RAW 264.7 macrophage cells. Results: The extract exerted significant 1,1-diphenyl-2-picrylhydrazyl and NO radical scavenging activity, and it exerted dramatic reducing power. Induction of iNOS and NO by LPS in RAW 264.7 cells was significantly inhibited by the extract, suggesting that the ARA extract inhibits NO production by suppressing iNOS expression. Strikingly, the ARA extracts substantially inhibited the receptor activator of NF-κB ligand-induced osteclastic differentiation of LPS-activated RAW 264.7 cells. The ARA extract contains a significant amount of antioxidant components, including phenolics, flavonoids and anthocyanins. Conclusion: These results suggest that the methanolic extract of ARA exerts significant antioxidant activities potentially via inhibiting free radicals and iNOS induction, thereby leading to the inhibition of osteoclastogenesis. PMID:25298665

  11. Inhibition of differentiation and function of osteoclasts by dimethyl sulfoxide (DMSO).

    PubMed

    Yang, Chunxi; Madhu, Vedavathi; Thomas, Candace; Yang, Xinlin; Du, Xeujun; Dighe, Abhijit S; Cui, Quanjun

    2015-12-01

    Dimethyl sulfoxide (DMSO) is an FDA-approved organosulfur solvent that is reported to have therapeutic value in osteoarthritis and osteopenia. DMSO is used as a cryoprotectant for the cryopreservation of bone grafts and mesenchymal stem cells which are later used for bone repair. It is also used as a solvent in the preparation of various scaffolds used for bone tissue engineering purposes. DMSO has been reported to inhibit osteoclast formation in vitro but the mechanism involved has remained elusive. We investigated the effect of DMSO on osteoclast differentiation and function using a conventional model system of RAW 264.7 cells. The differentiation of RAW 264.7 cells was induced by adding 50 ng/ml RANKL and the effect of DMSO (0.01 and 1% v/v) on RANKL-induced osteoclastogenesis was investigated. Addition of 1% DMSO significantly inhibited RANKL-induced formation of TRAP+, multinucleated, mature osteoclasts and osteoclast late-stage precursors (c-Kit(-) c-Fms(+) Mac-1(+) RANK(+)). While DMSO did not inhibit proliferation per se, it did inhibit the effect of RANKL on proliferation of RAW 264.7 cells. Key genes related to osteoclast function (TRAP, Integrin αVβ3, Cathepsin K and MMP9) were significantly down-regulated by DMSO. RANKL-induced expression of RANK gene was significantly reduced in the presence of DMSO. Our data, and reports from other investigators, that DMSO enhances osteoblastic differentiation of mesenchymal stem cells and also prevents bone loss in ovarietcomized rats, suggest that DMSO has tremendous potential in the treatment of osteoporosis and bone diseases arising from uncontrolled activities of the osteoclasts.

  12. ATXN1L, CIC, and ETS Transcription Factors Modulate Sensitivity to MAPK Pathway Inhibition

    PubMed Central

    Wang, Belinda; Krall, Elsa Beyer; Aguirre, Andrew James; Kim, Miju; Widlund, Hans Ragnar; Doshi, Mihir Bhavik; Sicinska, Ewa; Sulahian, Rita; Goodale, Amy; Cowley, Glenn Spencer; Piccioni, Federica; Doench, John Gerard; Root, David Edward; Hahn, William Chun

    2017-01-01

    SUMMARY Intrinsic resistance and RTK-RAS-MAPK pathway reactivation has limited the effectiveness of MEK and RAF inhibitors (MAPKi) in RAS- and RAF-mutant cancers. To identify genes that modulate sensitivity to MAPKi, we performed genome scale CRISPR-Cas9 loss-of-function screens in two KRAS-mutant pancreatic cancer cell lines treated with the MEK1/2 inhibitor trametinib. Loss of CIC, a transcriptional repressor of ETV1, 4, and 5, promoted survival in the setting of MAPKi in cancer cells derived from several lineages. ATXN1L deletion, which reduces CIC protein, or ectopic expression of ETV1, 4, or 5 also modulated sensitivity to trametinib. ATXN1L expression inversely correlates with response to MAPKi inhibition in clinical studies. These observations identify the ATXN1L-CIC-ETS transcription factor axis as a mediator of resistance to MAPKi. PMID:28178529

  13. Aerobic exercise modulates intracortical inhibition and facilitation in a nonexercised upper limb muscle

    PubMed Central

    2014-01-01

    Background Despite growing interest in the relationship between exercise and short-term neural plasticity, the effects of exercise on motor cortical (M1) excitability are not well studied. Acute, lower-limb aerobic exercise may potentially modulate M1 excitability in working muscles, but the effects on muscles not involved in the exercise are unknown. Here we examined the excitability changes in an upper limb muscle representation following a single session of lower body aerobic exercise. Investigating the response to exercise in a non-exercised muscle may help to determine the clinical usefulness of lower-body exercise interventions for upper limb neurorehabilitation. Methods In this study, transcranial magnetic stimulation was used to assess input–output curves, short-interval intracortical inhibition (SICI), long-interval intracortical inhibition (LICI) and intracortical facilitation (ICF) in the extensor carpi radialis muscle in twelve healthy individuals following a single session of moderate stationary biking. Additionally, we examined whether the presence of a common polymorphism of the brain-derived neurotrophic factor (BDNF) gene would affect the response of these measures to exercise. Results We observed significant increases in ICF and decreases in SICI following exercise. No changes in LICI were detected, and no differences were observed in input–output curves following exercise, or between BDNF groups. Conclusions The current results demonstrate that the modulation of intracortical excitability following aerobic exercise is not limited to those muscles involved in the exercise, and that while exercise does not directly modulate the excitability of motor neurons, it may facilitate the induction of experience-dependent plasticity via a decrease in intracortical inhibition and increase in intracortical facilitation. These findings indicate that exercise may create favourable conditions for adaptive plasticity in M1 and may be an effective adjunct to

  14. Inhibition of Osteoblastic Cell Differentiation by Lipopolysaccharide Extract from Porphyromonas gingivalis

    PubMed Central

    Kadono, Hiroyuki; Kido, Jun-Ichi; Kataoka, Masatoshi; Yamauchi, Noriyuki; Nagata, Toshihiko

    1999-01-01

    Lipopolysaccharide from Porphyromonas gingivalis (P-LPS), an important pathogenic bacterium, is closely associated with inflammatory destruction of periodontal tissues. P-LPS induces the release of cytokines and local factors from inflammatory cells, stimulates osteoclastic-cell differentiation, and causes alveolar bone resorption. However, the effect of P-LPS on osteoblastic-cell differentiation remains unclear. In this study, we investigated the effect of P-LPS extract prepared by the hot-phenol–water method, on the differentiation of primary fetal rat calvaria (RC) cells, which contain a subpopulation of osteoprogenitor cells, into osteoblastic cells. P-LPS extract significantly inhibited bone nodule (BN) formation and the activity of alkaline phosphatase (ALPase), an osteoblastic marker, in a dose-dependent manner (0 to 100 ng of P-LPS extract per ml). P-LPS extract (100 ng/ml) significantly decreased BN formation to 27% of the control value and inhibited ALPase activity to approximately 60% of the control level on days 10 to 21 but did not affect RC cell proliferation and viability. P-LPS extract time-dependently suppressed the expression of ALPase mRNA, with an inhibitory pattern similar to that of enzyme activity. The expression of mRNAs for osteocalcin and osteopontin, matrix proteins related to bone metabolism, was markedly suppressed by P-LPS extract. Furthermore, P-LPS extract increased the expression of mRNAs for CD14, LPS receptor, and interleukin-1β in RC cells. These results indicate that P-LPS inhibits osteoblastic-cell differentiation and suggest that LPS-induced bone resorption in periodontal disease may be mediated by effects on osteoblastic as well as osteoclastic cells. PMID:10338489

  15. Wavelength-modulated differential photothermal radiometry: Theory and experimental applications to glucose detection in water

    NASA Astrophysics Data System (ADS)

    Mandelis, Andreas; Guo, Xinxin

    2011-10-01

    A differential photothermal radiometry method, wavelength-modulated differential photothermal radiometry (WM-DPTR), has been developed theoretically and experimentally for noninvasive, noncontact biological analyte detection, such as blood glucose monitoring. WM-DPTR features analyte specificity and sensitivity by combining laser excitation by two out-of-phase modulated beams at wavelengths near the peak and the base line of a prominent and isolated mid-IR analyte absorption band (here the carbon-oxygen-carbon bond in the pyran ring of the glucose molecule). A theoretical photothermal model of WM-DPTR signal generation and detection has been developed. Simulation results on water-glucose phantoms with the human blood range (0-300 mg/dl) glucose concentration demonstrated high sensitivity and resolution to meet wide clinical detection requirements. The model has also been validated by experimental data of the glucose-water system obtained using WM-DPTR.

  16. Differential modulation of TWIK-related K(+) channel (TREK) and TWIK-related acid-sensitive K(+) channel 2 (TASK2) activity by pyrazole compounds.

    PubMed

    Kim, Hyun Jong; Woo, Joohan; Nam, Yuran; Nam, Joo Hyun; Kim, Woo Kyung

    2016-11-15

    Pyrazole derivatives were originally suggested as selective blockers of the transient receptor potential cation 3 (TRPC3) and channel. In particular, pyr3 and 10 selectively inhibit TRPC3, whereas pyr2 (BTP2) and 6 inhibit ORAI1. However, their effects on background K(+) channel activity have not been elucidated. In this study, the effects of BTP2, pyr3, pyr6, and pyr10 were studied on cloned human TWIK-related K(+) channels (TREKs) and TWIK-related acid-sensitive K(+) channel 2 (TASK-2) channels, which modulate Ca(2+) signaling by controlling membrane potential, in HEK293T-overexpressing cells by using a whole-cell patch clamp technique. Pyr3 potently inhibited TREK-1 (ITREK1), TREK-2 (ITREK2), and TASK2 current (ITASK-2) with half-maximal inhibitory concentrations (IC50) of 0.89±0.27, 1.95±1.44, and 2.42±0.39µM, respectively. BTP2 slightly inhibited ITASK-2 (80.3±2.5% at 100μM). In contrast, pyr6 at 100µM potentiated ITREK1 and ITREK2 by approximately 2.6- and 3.6-fold compared to the control and inhibited ITASK2 (38.7±9.2%). Pyr10 showed a subtype-specific inhibition of ITREK1 but not ITREK2. It also inhibited ITASK2 (70.9±3.1% at 100μM). To the best of our knowledge, this study is the first to describe the differential modulation of TREKs and TASK2 channels by pyrazole derivatives, previously used as inhibitors of TRPC3 and ORAI1. Therefore, studies using these drugs should consider their modulation of other channels such as TREK and TASK-2.

  17. A small molecule modulates Jumonji histone demethylase activity and selectively inhibits cancer growth

    PubMed Central

    Wang, Lei; Chang, Jianjun; Varghese, Diana; Dellinger, Michael; Kumar, Subodh; Best, Anne M.; Ruiz, Julio; Bruick, Richard; Peña-Llopis, Samuel; Xu, Junjie; Babinski, David J.; Frantz, Doug E.; Brekken, Rolf A.; Quinn, Amy M.; Simeonov, Anton; Easmon, Johnny; Martinez, Elisabeth D.

    2013-01-01

    The pharmacological inhibition of general transcriptional regulators has the potential to block growth through targeting multiple tumorigenic signaling pathways simultaneously. Here, using an innovative cell-based screen, we identify a structurally unique small molecule (named JIB-04) which specifically inhibits the activity of the Jumonji family of histone demethylases in vitro, in cancer cells, and in tumors in vivo. Unlike known inhibitors, JIB-04 is not a competitive inhibitor of α-ketoglutarate. In cancer but not in patient-matched normal cells, JIB-04 alters a subset of transcriptional pathways and blocks viability. In mice, JIB-04 reduces tumor burden and prolongs survival. Importantly, we find that patients with breast tumors that overexpress Jumonji demethylases have significantly lower survival. Thus JIB-04, a novel inhibitor of Jumonji demethylases in vitro and in vivo, constitutes a unique potential therapeutic and research tool against cancer, and validates the use of unbiased cellular screens to discover chemical modulators with disease relevance. PMID:23792809

  18. Reward-Modulated Response Inhibition, Cognitive Shifting, and the Orbital Frontal Cortex in Early Adolescence

    PubMed Central

    Zhai, Zu Wei; Pajtek, Stefan; Luna, Beatriz; Geier, Charles F.; Ridenour, Ty A.; Clark, Duncan B.

    2014-01-01

    Immaturities in cognitive shifting are associated with adolescent risk behaviors. The orbital frontal cortex (OFC) regulates reward processing and response inhibition. This study tested the relationship between cognitive shifting, OFC activity, and reward-modulated response inhibition in young adolescents. An fMRI antisaccade (AS) paradigm examined the effects of reward conditions on inhibitory response and OFC processing. A validated self-report inventory assessed cognitive shifting. Compared to neutral, reward trials showed better AS performance and increased OFC activation. Cognitive shifting positively associated with AS performance in reward and neutral trials. Poorer cognitive shifting predicted greater OFC activation. Results indicate lower OFC efficiency, as greater activation to achieve correct performance, underlies cognitive shifting problems. These neurocognitive impairments are relevant for understanding adolescent risk behaviors. PMID:26755891

  19. Osthole inhibits histamine-dependent itch via modulating TRPV1 activity

    PubMed Central

    Yang, Niu-Niu; Shi, Hao; Yu, Guang; Wang, Chang-Ming; Zhu, Chan; Yang, Yan; Yuan, Xiao-Lin; Tang, Min; Wang, Zhong-li; Gegen, Tana; He, Qian; Tang, Kehua; Lan, Lei; Wu, Guan-Yi; Tang, Zong-Xiang

    2016-01-01

    Osthole, an active coumarin isolated from Cnidium monnieri (L.) Cusson, has long been used in China as an antipruritic herbal medicine; however, the antipruitic mechanism of osthole is unknown. We studied the molecular mechanism of osthole in histamine-dependent itch by behavioral test, Ca2+ imaging, and electrophysiological experiments. First, osthole clearly remitted the scratching behaviors of mice induced with histamine, HTMT, and VUF8430. Second, in cultured dorsal root ganglion (DRG) neurons, osthole showed a dose-dependent inhibitory effect to histamine. On the same neurons, osthole also decreased the response to capsaicin and histamine. In further tests, the capsaicin-induced inward currents were inhibited by osthole. These results revealed that osthole inhibited histamine-dependent itch by modulating TRPV1 activity. This study will be helpful in understanding how osthole exerts anti-pruritus effects and suggests that osthole may be a useful treatment medicine for histamine-dependent itch. PMID:27160770

  20. An Iridium(III) Complex Inhibits JMJD2 Activities and Acts as a Potential Epigenetic Modulator.

    PubMed

    Liu, Li-Juan; Lu, Lihua; Zhong, Hai-Jing; He, Bingyong; Kwong, Daniel W J; Ma, Dik-Lung; Leung, Chung-Hang

    2015-08-27

    A novel iridium(III) complex was synthesized and evaluated for its ability to target JMJD2 enzymatic activity. The iridium(III) complex 1 can inhibit JMJD2 activity and was selective for JMJD2 activity over JARID, JMJD3, and HDAC activities. Moreover, 1 suppressed the trimethylation of the p21 promoter on H3K9me3 and interrupted the JMJD2D-H3K9me3 interactions in human cells, suggesting that it could act as an epigenetic modulator. To our knowledge, 1 represents the first metal-based JMJD2 inhibitor reported in the literature.

  1. wALADin Benzimidazoles Differentially Modulate the Function of Porphobilinogen Synthase Orthologs

    PubMed Central

    2015-01-01

    The heme biosynthesis enzyme porphobilinogen synthase (PBGS) is a potential drug target in several human pathogens. wALADin1 benzimidazoles have emerged as species-selective PBGS inhibitors against Wolbachia endobacteria of filarial worms. In the present study, we have systematically tested wALADins against PBGS orthologs from bacteria, protozoa, metazoa, and plants to elucidate the inhibitory spectrum. However, the effect of wALADin1 on different PBGS orthologs was not limited to inhibition: several orthologs were stimulated by wALADin1; others remained unaffected. We demonstrate that wALADins allosterically modulate the PBGS homooligomeric equilibrium with inhibition mediated by favoring low-activity oligomers, while 5-aminolevulinic acid, Mg2+, or K+ stabilized high-activity oligomers. Pseudomonas aeruginosa PBGS could be inhibited or stimulated by wALADin1 depending on these factors and pH. We have defined the wALADin chemotypes responsible for either inhibition or stimulation, facilitating the design of tailored PBGS modulators for potential application as antimicrobial agents, herbicides, or drugs for porphyric disorders. PMID:24568185

  2. Plumbagin inhibits breast tumor bone metastasis and osteolysis by modulating the tumor-bone microenvironment.

    PubMed

    Li, Z; Xiao, J; Wu, X; Li, W; Yang, Z; Xie, J; Xu, L; Cai, X; Lin, Z; Guo, W; Luo, J; Liu, M

    2012-09-01

    Bone metastasis is a common and serious consequence of breast cancer. Bidirectional interaction between tumor cells and the bone marrow microenvironment drives a so-called 'vicious cycle' that promotes tumor cell malignancy and stimulates osteolysis. Targeting these interactions and pathways in the tumor-bone microenvironment has been an encouraging strategy for bone metastasis therapy. In the present study, we examined the effects of plumbagin on breast cancer bone metastasis. Our data indicated that plumbagin inhibited cancer cell migration and invasion, suppressed the expression of osteoclast-activating factors, altered the cancer cell induced RANKL/OPG ratio in osteoblasts, and blocked both cancer cell- and RANKL-stimulated osteoclastogenesis. In mouse model of bone metastasis, we further demonstrated that plumbagin significantly repressed breast cancer cell metastasis and osteolysis, inhibited cancer cell induced-osteoclastogenesis and the secretion of osteoclast-activating factors in vivo. At the molecular level, we found that plumbagin abrogated RANKL-induced NF-κB and MAPK pathways by blocking RANK association with TRAF6 in osteoclastogenesis, and by inhibiting the expression of osteoclast-activating factors through the suppression of NF-κB activity in breast cancer cells. Taken together, our data demonstrate that plumbagin inhibits breast tumor bone metastasis and osteolysis by modulating the tumor-bone microenvironment and that plumbagin may serve as a novel agent in the treatment of tumor bone metastasis.

  3. Slow and sustained nitric oxide releasing compounds inhibit multipotent vascular stem cell proliferation and differentiation without causing cell death

    SciTech Connect

    Curtis, Brandon M.; Leix, Kyle Alexander; Ji, Yajing; Glaves, Richard Samuel Elliot; Ash, David E.; Mohanty, Dillip K.

    2014-07-18

    Highlights: • Multipotent vascular stem cells (MVSCs) proliferate and differentiate. • Nitric oxide inhibits proliferation of MVSCs. • Nitric oxide inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs). • Smooth muscle cells (SMCs) neither de-differentiate nor proliferate. - Abstract: Atherosclerosis is the leading cause of cerebral and myocardial infarction. It is believed that neointimal growth common in the later stages of atherosclerosis is a result of vascular smooth muscle cell (SMC) de-differentiation in response to endothelial injury. However, the claims of the SMC de-differentiation theory have not been substantiated by monitoring the fate of mature SMCs in response to such injuries. A recent study suggests that atherosclerosis is a consequence of multipotent vascular stem cell (MVSC) differentiation. Nitric oxide (NO) is a well-known mediator against atherosclerosis, in part because of its inhibitory effect on SMC proliferation. Using three different NO-donors, we have investigated the effects of NO on MVSC proliferation. Results indicate that NO inhibits MVSC proliferation in a concentration dependent manner. A slow and sustained delivery of NO proved to inhibit proliferation without causing cell death. On the other hand, larger, single-burst NO concentrations, inhibits proliferation, with concurrent significant cell death. Furthermore, our results indicate that endogenously produced NO inhibits MVSC differentiation to mesenchymal-like stem cells (MSCs) and subsequently to SMC as well.

  4. Inhibition of peroxisome proliferator-activated receptor (PPAR)-mediated keratinocyte differentiation by lipoxygenase inhibitors.

    PubMed Central

    Thuillier, Philippe; Brash, Alan R; Kehrer, James P; Stimmel, Julie B; Leesnitzer, Lisa M; Yang, Peiying; Newman, Robert A; Fischer, Susan M

    2002-01-01

    Lipoxygenase (LOX) metabolites from arachidonic acid and linoleic acid have been implicated in atherosclerosis, inflammation, keratinocyte differentiation and tumour progression. We previously showed that peroxisome proliferator-activated receptors (PPARs) play a role in keratinocyte differentiation and that the PPARalpha ligand 8S-hydroxyeicosatetraenoic acid is important in this process. We hypothesized that blocking LOX activity would block PPAR-mediated keratinocyte differentiation. Three LOX inhibitors, nordihydroguaiaretic acid, quercetin and morin, were studied for their effects on primary keratinocyte differentiation and PPAR activity. All three LOX inhibitors blocked calcium-induced expression of the differentiation marker keratin 1. In addition, activity of a PPAR-responsive element was inhibited in the presence of all three inhibitors, and this effect was mediated primarily through PPARalpha and PPARgamma. LOX inhibitors decreased the activity of a chimaeric PPAR-Gal4-ligand-binding domain reporter system and this effect was reversed by addition of PPAR ligands. Ligand-binding studies revealed that the LOX inhibitors bind directly to PPARs and demonstrate a novel mechanism for these inhibitors in altering PPAR-mediated gene expression. PMID:12069687

  5. cGMP modulates stem cells differentiation to neurons in brain in vivo.

    PubMed

    Gómez-Pinedo, U; Rodrigo, R; Cauli, O; Herraiz, S; Garcia-Verdugo, J-M; Pellicer, B; Pellicer, A; Felipo, V

    2010-02-17

    During brain development neural stem cells may differentiate to neurons or to other cell types. The aim of this work was to assess the role of cGMP (cyclic GMP) in the modulation of differentiation of neural stem cells to neurons or non-neuronal cells. cGMP in brain of fetuses was reduced to 46% of controls by treating pregnant rats with nitroarginine-methylester (L-NAME) and was restored by co-treatment with sildenafil.Reducing cGMP during brain development leads to reduced differentiation of stem cells to neurons and increased differentiation to non-neuronal cells. The number of neurons in the prefrontal cortex originated from stem cells proliferating on gestational day 14 was 715+/-14/mm(2) in control rats and was reduced to 440+/-29/mm(2) (61% of control) in rats treated with L-NAME. In rats exposed to L-NAME plus sildenafil, differentiation to neurons was completely normalized, reaching 683+/-11 neurons/mm(2). In rats exposed to sildenafil alone the number of cells labelled with bromodeoxyuridine (BrdU) and NeuN was 841+/-16/mm(2). In prefrontal cortex of control rats 48% of the neural stem cells proliferating in gestational day 14 differentiate to neurons, but only 24% in rats exposed to L-NAME. This was corrected by sildenafil, 40% of cells differentiate to neurons. Similar results were obtained for neurons proliferating during all developmental period. Treatment with L-NAME did not reduce the total number of cells labelled with BrdU, further supporting that L-NAME reduces selectively the differentiation of stem cells to neurons. Similar results were obtained in hippocampus. Treatment with L-NAME reduced the differentiation of neural stem cells to neurons, although the effect was milder than in prefrontal cortex. These results support that cGMP modulates the fate of neural stem cells in brain in vivo and suggest that high cGMP levels promote its differentiation to neurons while reduced cGMP levels promote differentiation to non-neuronal cells.

  6. Inhibition of osteoclast differentiation by polycyclic aryl hydrocarbons is dependent on cell density and RANKL concentration.

    PubMed

    Voronov, I; Heersche, J N M; Casper, R F; Tenenbaum, H C; Manolson, M F

    2005-07-15

    We investigated the effect of representative polycyclic aryl hydrocarbons (PAHs), benzo[a]pyrene (BaP), and 7,12-dimethylbenz[a]anthracene (DMBA) on osteoclast differentiation and function by using dispersed cancellous bone derived rabbit osteoclasts and the RAW264.7 cells. These cells differentiate into osteoclasts when exposed to receptor activator of NF-kappaB ligand (RANKL). The rabbit osteoclasts were exposed to 10(-6) to 10(-9)M BaP or DMBA and the tartrate-resistant acid phosphatase (TRAP)-positive cells were counted. The effect of PAHs on osteoclast differentiation in dispersed rabbit osteoclast-containing stromal cell populations was cell density dependent, suggesting that the cell density of stromal cells, osteoclast precursors, and/or mature osteoclasts are factors regulating the effect of PAHs. To investigate the direct effect of BaP on osteoclast differentiation, RAW264.7 cells were exposed to 10(-5) to 10(-6) M BaP. Treatment of RAW264.7 cells cultured with 25 ng/ml soluble RANKL and 10(-5)M BaP for 5 days decreased osteoclast differentiation, TRAP activity levels, and resorption of bone-like substrata. The inhibition was prevented by 10(-6) to 10(-7) M resveratrol, an aryl hydrocarbon receptor (AhR) antagonist, and by higher concentrations of RANKL. To investigate the ability of RANKL to reverse BaP-mediated inhibition, gene expression was determined by RT-PCR. Cytochrome P450 1B1 (CYP1B1) mRNA, one of the genes activated by BaP, was present only in the groups exposed to BaP; the levels of CYP1B1 mRNA decreased in the presence of increasing concentrations of RANKL. These results suggest that the inhibitory effects of PAHs on osteoclastogenesis are direct and likely involve interaction of the RANKL and PAH signaling pathways.

  7. Tributyltin and triphenyltin inhibit osteoclast differentiation through a retinoic acid receptor-dependent signaling pathway

    SciTech Connect

    Yonezawa, Takayuki; Hasegawa, Shin-ichi; Ahn, Jae-Yong; Cha, Byung-Yoon; Teruya, Toshiaki; Hagiwara, Hiromi; Nagai, Kazuo; Woo, Je-Tae; E-mail: jwoo@isc.chubu.ac.jp

    2007-03-30

    Organotin compounds, such as tributyltin (TBT) and triphenyltin (TPT), have been widely used in agriculture and industry. Although these compounds are known to have many toxic effects, including endocrine-disrupting effects, their effects on bone resorption are unknown. In this study, we investigated the effects of organotin compounds, such as monobutyltin (MBT), dibutyltin (DBT), TBT, and TPT, on osteoclast differentiation using mouse monocytic RAW264.7 cells. MBT and DBT had no effects, whereas TBT and TPT dose-dependently inhibited osteoclast differentiation at concentrations of 3-30 nM. Treatment with a retinoic acid receptor (RAR)-specific antagonist, Ro41-5253, restored the inhibition of osteoclastogenesis by TBT and TPT. TBT and TPT reduced receptor activator of nuclear factor-{kappa}B ligand (RANKL) induced nuclear factor of activated T cells (NFAT) c1 expression, and the reduction in NFATc1 expression was recovered by Ro41-5253. Our results suggest that TBT and TPT suppress osteoclastogenesis by inhibiting RANKL-induced NFATc1 expression via an RAR-dependent signaling pathway.

  8. WEHI-3 cells inhibit adipocyte differentiation in 3T3-L1 cells

    SciTech Connect

    Lai, Jing; Liu, Gexiu; Yan, Guoyao; He, Dongmei; Zhou, Ying; Chen, Shengting

    2015-06-26

    By investigating the anti-adipogenic effects of WEHI-3 cells – a murine acute myelomonocytic leukemia cell line – we sought to improve the efficiency of hematopoietic stem cell transplantation (HSCT). Analysis of Oil Red O staining and the expression of adipogenic genes, including PPARγ, C/EBPα, FAS and LPL, indicated that WEHI-3 cells significantly inhibited 3T3-L1 mouse preadipocyte cells from differentiating into adipocytes. In vivo, fat vacuoles in mice injected with WEHI-3 cells were also remarkably reduced in the murine bone marrow pimelosis model. Moreover, the key gene in the Rho signaling pathway, ROCKII, and the key gene in the Wnt signaling pathway, β-catenin, were both upregulated compared with the control group. siRNA-mediated knockdown of ROCKII and β-catenin reversed these WEHI-3-mediated anti-adipogenic effects. Taken together, these data suggest that WEHI-3 cells exert anti-adipogenic effects and that both ROCKII and β-catenin are involved in this process. - Highlights: • WEHI-3, an acute myelomonocytic leukemia cell line, inhibited 3T3-L1 preadipocyte from differentiating into adipocyte. • WEHI-3 cells can arrest 3T3-L1 cells in G0/G1 phase by secreting soluble factors and thus inhibit their proliferation. • WEHI-3 cells reduced bone marrow pimelosis in the murine model. • Both ROCKII and β-catenin were involved in the WEHI-3-mediated anti-adipogenic effects.

  9. Berberine inhibits 3T3-L1 adipocyte differentiation through the PPARgamma pathway.

    PubMed

    Huang, Cheng; Zhang, Yuebo; Gong, Zhenwei; Sheng, Xiaoyan; Li, Zongmeng; Zhang, Wei; Qin, Ying

    2006-09-22

    Berberine (BBR), a compound purified from Cortidis rhizoma, reduces serum cholesterol, triglycerides, and LDL-cholesterol of hypercholesterolemic patients and high fat diet fed animals, and increases hepatic LDLR mRNA and protein levels through a post-transcriptional mechanism. BBR also enhances the hypoglycemic action of insulin in diabetic animal models. Here, we show that BBR inhibits the differentiation of 3T3-L1 preadipocytes induced by DM and suppresses the mitotic clonal expansion of 3T3-L1 preadipocytes in a time- and dose-dependent manner. Gene expression analysis and Western blot analysis reveal that the BBR inhibits the mRNA and protein levels of adipogenesis related transcription factors PPARgamma and C/EBPalpha and their upstream regulator, C/EBPbeta. Reporter gene assays demonstrate that the full-length PPARgamma and alpha transcription activities are inhibited by BBR. Using real-time PCR, we have also found that the PPAR target genes that are involved in adipocyte differentiation, such as aP2, CD36, ACO, LPL, and other adipocyte markers, are suppressed by BBR. These studies suggest that BBR works on multiple molecular targets as an inhibitor of PPARgamma and alpha, and is a potential weight reducing, hypolipidemic, and hypoglycemic drug.

  10. Inhibition of mouse B16 melanoma by sodium butyrate correlated to tumor associated macrophages differentiation suppression

    PubMed Central

    Xiong, Fen; Mou, Yun-Zhu; Xiang, Xiao-Yan

    2015-01-01

    Objective: As one member of the histone deacetylase inhibitor (HDACi) family, Sodium butyrate (NaB) was found out that could be used as a differentiation inducer of much cancer cell. But its effects on tumor microenvironment cells are not well recognized. The goal of this research is to investigate the effect of NaB on B16 melanoma and analysis its relevant mechanism. Methods: We observed the effect of sodium butyrate on B16 melanoma in vivo and in vitro. MTT method was performed to detect cell apoptosis rate after treatment. Tumor associated macrophage infiltration condition was detected by flow cytometry. Western-blotting and immunohistochemical method were used to detect the expression of tumor associated macrophage cytokines. Results: A certain concentration of sodium butyrate could effectively inhibit B16 melanoma growth in vivo and in vitro, and this inhibition effects related to the suppression of tumor associated macrophage differentiation. At the same time we observed the relevant macrophage factors were down-regulated compared to the control. Conclusion: Sodium butyrate could effectively inhibit B16 melanoma growth through suppressing tumor associated macrophage proliferation and reduce relevant pro-tumor macrophage factors expression, which may help to promote the clinical study of melanoma epigenetic therapy. PMID:26064327

  11. The effect of electromagnetic fields on the proliferation and the osteogenic or adipogenic differentiation of mesenchymal stem cells modulated by dexamethasone.

    PubMed

    Song, Mingyu; Zhao, Dongming; Wei, Sheng; Liu, Chaoxu; Liu, Yang; Wang, Bo; Zhao, Wenchun; Yang, Kaixiang; Yang, Yong; Wu, Hua

    2014-10-01

    Although glucocorticoids provide benefits for inflammation or autoimmune disorders, high-dose and long-term use could cause osteonecrosis or osteoporosis as adverse effect for patients. Electromagnetic field (EMF) treatments have been clinically used for many years to promote fracture healing, but whether EMF can attenuate the deleterious effects of glucocorticoids is not clear. In this study, the effects of different concentrations of dexamethasone (DEX) on proliferation and adipogenic or osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) were detected and compared, and the effects of EMF treatment (15 Hz, 1 mT, 4 h/day) on 0.1 µM DEX-modulated BMSCs' proliferation and adipogenic or osteogenic differentiation were investigated. Higher concentrations of DEX (0.1 and 1 µM) inhibited proliferation of BMSCs but promoted expression of adipogenic-related genes, increasing the number of lipid droplets. In the early stage of differentiation, DEX restrained expression of RUNX2 and alkaline phosphatase (ALP), but amplified expression of ALP and osteopontin (OPN) in the late stage. EMF treatment of BMSCs influenced by 0.1 µM DEX inhibited the high expression of adipogenic-related genes, stimulated the expression of RUNX2, ALP, OPN, and osteocalcin, and increased the activity of ALP. EMF exposure augmented the expression of p-ERK, which DEX reduced. After using mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK signaling pathway inhibitor, U0126, the effect of EMF was reduced. In conclusion, EMF exposure accelerates BMSCs proliferation, inhibits adipogenic differentiation, and promotes osteogenic differentiation of BMSCs modulated by DEX, and these effects are mediated at least in part by MEK/ERK signaling pathway.

  12. Biochanin a promotes osteogenic but inhibits adipogenic differentiation: evidence with primary adipose-derived stem cells.

    PubMed

    Su, Shu-Jem; Yeh, Yao-Tsung; Su, Shu-Hui; Chang, Kee-Lung; Shyu, Huey-Wen; Chen, Kuan-Ming; Yeh, Hua

    2013-01-01

    Biochanin A has promising effects on bone formation in vivo, although the underlying mechanism remains unclear yet. This study therefore aimed to investigate whether biochanin A regulates osteogenic and adipogenic differentiation using primary adipose-derived stem cells. The effects of biochanin A (at a physiologically relevant concentration of 0.1-1 μM) were assessed in vitro using various approaches, including Oil red O staining, Nile red staining, alizarin red S staining, alkaline phosphatase (ALP) activity, flow cytometry, RT-PCR, and western blotting. The results showed that biochanin A significantly suppressed adipocyte differentiation, as demonstrated by the inhibition of cytoplasmic lipid droplet accumulation, along with the inhibition of peroxisome proliferator-activated receptor gamma (PPAR γ ), lipoprotein lipase (LPL), and leptin and osteopontin (OPN) mRNA expression, in a dose-dependent manner. On the other hand, treatment of cells with 0.3 μM biochanin A increased the mineralization and ALP activity, and stimulated the expression of the osteogenic marker genes ALP and osteocalcin (OCN). Furthermore, biochanin A induced the expression of runt-related transcription factor 2 (Runx2), osteoprotegerin (OPG), and Ras homolog gene family, member A (RhoA) proteins. These observations suggest that biochanin A prevents adipogenesis, enhances osteoblast differentiation in mesenchymal stem cells, and has beneficial regulatory effects in bone formation.

  13. Modulation of Prepulse Inhibition and Startle Reflex by Emotions: A Comparison between Young and Older Adults

    PubMed Central

    Le Duc, Jolyanne; Fournier, Philippe; Hébert, Sylvie

    2016-01-01

    This study examined whether or not the acoustic startle response and sensorimotor gating may be modulated by emotions differentially between young and older adults. Two groups of participants (mean age Young: 24 years old; Elderly: 63.6 years old) were presented with three types of auditory stimuli (Startle alone, High or Low frequency Prepulse) while viewing pleasant, neutral, or unpleasant images. Electromyographic activity of the eyeblink response was measured. Results show that older adults displayed diminished eyeblink responses whereas younger adults displayed enhanced eyeblink responses when viewing negative images. Sensorimotor gating also differed between young and older adults, with enhanced sensorimotor gating abilities while viewing positive pictures in older adults and diminished abilities while viewing negative pictures among younger adults. These results argue in favor of a differential emotional influence on the sensorimotor abilities of young and older adults, with a positivity bias among the latter. PMID:26941643

  14. Estrogen-related receptor alpha modulates the expression of adipogenesis-related genes during adipocyte differentiation.

    PubMed

    Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Yagi, Ken; Okazaki, Yasushi; Inoue, Satoshi

    2007-07-06

    Estrogen-related receptor alpha (ERRalpha) is an orphan nuclear receptor that regulates cellular energy metabolism by modulating gene expression involved in fatty acid oxidation and mitochondrial biogenesis in brown adipose tissue. However, the physiological role of ERRalpha in adipogenesis and white adipose tissue development has not been well studied. Here, we show that ERRalpha and ERRalpha-related transcriptional coactivators, peroxisome proliferator-activated receptor gamma (PPARgamma) coactivator-1alpha (PGC-1alpha) and PGC-1beta, can be up-regulated in 3T3-L1 preadipocytes at mRNA levels under the adipogenic differentiation condition including the inducer of cAMP, glucocorticoid, and insulin. Gene knockdown by ERRalpha-specific siRNA results in mRNA down-regulation of fatty acid binding protein 4, PPARgamma, and PGC-1alpha in 3T3-L1 cells in the adipogenesis medium. ERRalpha and PGC-1beta mRNA expression can be also up-regulated in another preadipocyte lineage DFAT-D1 cells and a pluripotent mesenchymal cell line C3H10T1/2 under the differentiation condition. Furthermore, stable expression of ERRalpha in 3T3-L1 cells up-regulates adipogenic marker genes and promotes triglyceride accumulation during 3T3-L1 differentiation. These results suggest that ERRalpha may play a critical role in adipocyte differentiation by modulating the expression of various adipogenesis-related genes.

  15. Cellular differentiation and I-FABP protein expression modulate fatty acid uptake and diffusion.

    PubMed

    Atshaves, B P; Foxworth, W B; Frolov, A; Roths, J B; Kier, A B; Oetama, B K; Piedrahita, J A; Schroeder, F

    1998-03-01

    The effect of cellular differentiation on fatty acid uptake and intracellular diffusion was examined in transfected pluripotent mouse embryonic stem (ES) cells stably expressing intestinal fatty acid binding protein (I-FABP). Control ES cells, whether differentiated or undifferentiated, did not express I-FABP. The initial rate and maximal uptake of the fluorescent fatty acid, 12-(N-methyl)-N-[(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-octadec anoic acid (NBD-stearic acid), was measured in single cells by kinetic digital fluorescence imaging. I-FABP expression in undifferentiated ES cells increased the initial rate and maximal uptake of NBD-stearic acid 1.7- and 1.6-fold, respectively, as well as increased its effective intracellular diffusion constant (Deff) 1.8-fold as measured by the fluorescence recovery after photobleaching technique. In contrast, ES cell differentiation decreased I-FABP expression up to 3-fold and decreased the NBD-stearic acid initial rate of uptake, maximal uptake, and Deff by 10-, 4.7-, and 2-fold, respectively. There were no significant differences in these parameters between the differentiated control and differentiated I-FABP-expressing ES cell lines. In summary, differentiation and expression of I-FABP oppositely modulated NBD-stearic acid uptake parameters and intracellular diffusion in ES cells.

  16. Neuronal differentiation modulates the dystrophin Dp71d binding to the nuclear matrix

    SciTech Connect

    Rodriguez-Munoz, Rafael; Villarreal-Silva, Marcela; Gonzalez-Ramirez, Ricardo; Garcia-Sierra, Francisco; Mondragon, Monica; Mondragon, Ricardo; Cerna, Joel; Cisneros, Bulmaro

    2008-10-24

    The function of dystrophin Dp71 in neuronal cells remains unknown. To approach this issue, we have selected the PC12 neuronal cell line. These cells express both a Dp71f cytoplasmic variant and a Dp71d nuclear isoform. In this study, we demonstrated by electron and confocal microscopy analyses of in situ nuclear matrices and Western blotting evaluation of cell extracts that Dp71d associates with the nuclear matrix. Interestingly, this binding is modulated during NGF-induced neuronal differentiation of PC12 cells with a twofold increment in the differentiated cells, compared to control cells. Also, distribution of Dp71d along the periphery of the nuclear matrix observed in the undifferentiated cells is replaced by intense fluorescent foci localized in Center of the nucleoskeletal structure. In summary, we revealed that Dp71d is a dynamic component of nuclear matrix that might participate in the nuclear modeling occurring during neuronal differentiation.

  17. Smad7 mediates inhibition of Saos2 osteosarcoma cell differentiation by NF{kappa}B

    SciTech Connect

    Eliseev, Roman A. . E-mail: Roman_Eliseev@urmc.rochester.edu; Schwarz, Edward M.; Zuscik, Michael J.; O'Keefe, Regis J.; Drissi, Hicham; Rosier, Randy N.

    2006-01-01

    The transcription factor NF{kappa}B is constitutively activated in various tumor cells where it promotes proliferation and represses apoptosis. The bone morphogenetic proteins (BMPs) delay cell proliferation and promote differentiation and apoptosis of bone cells through activation of Smad downstream effectors and via Smad-independent mechanisms. Thus, NF{kappa}B and BMP pathways play opposing roles in regulating osteoblastic cell fate. Here, we show that in osteosarcoma Saos2 osteoblasts, NF{kappa}B regulates the activity of the BMP/Smad signaling. Inhibition of NF{kappa}B by overexpression of mI{kappa}B leads to the induction of osteoblast differentiation. Saos2 cells overexpressing mI{kappa}B (Saos2-mI{kappa}B) exhibit higher expression of osteoblast phenotypic genes such as alkaline phosphatase, Runx2 and osteocalcin and are more responsive to BMP2 in comparison to wild-type cells (Saos2-wt) or empty vector infected controls (Saos2-EV). Furthermore, BMP-2 signaling and Smad phosphorylation are significantly increased in Saos2-mI{kappa}B cells in comparison to Saos2-EV cells. Inhibition of NF{kappa}B signaling in Saos2-mI{kappa}B cells is associated with decreased expression of the BMP signaling inhibitor Smad7. While gain of Smad7 function in Saos2-mI{kappa}B cells results in inhibition of BMP signaling, anti-sense knockdown of Smad7 in Saos2-EV cells leads to upregulation of BMP signaling. We therefore conclude that in osteosarcoma Saos2 cells, NF{kappa}B represses BMP/Smad signaling and BMP2-induced differentiation through Smad7.

  18. Inhibition of GSK-3 induces differentiation and impaired glucose metabolism in renal cancer

    PubMed Central

    Pal, Krishnendu; Cao, Ying; Gaisina, Irina N.; Bhattacharya, Santanu; Dutta, Shamit K.; Wang, Enfeng; Gunosewoyo, Hendra; Kozikowski, Alan P.; Billadeau, Daniel D.; Mukhopadhyay, Debabrata

    2014-01-01

    Glycogen synthase kinase-3 (GSK-3), a constitutively active serine/threonine kinase, is a key regulator of numerous cellular processes ranging from glycogen metabolism to cell cycle regulation and proliferation. Consistent with its involvement in many pathways, it has also been implicated in the pathogenesis of various human diseases including Type II diabetes, Alzheimer's disease, bipolar disorder, inflammation and cancer. Consequently it is recognized as an attractive target for the development of new drugs. In the present study, we investigated the effect of both pharmacological and genetic inhibition of GSK-3 in two different renal cancer cell lines. We have shown potent anti-proliferative activity of 9-ING-41, a maleimide-based GSK-3 inhibitor. The anti-proliferative activity is most likely caused by G0–G1 and G2-M phase arrest as evident from cell cycle analysis. We have established that inhibition of GSK-3 imparted a differentiated phenotype in renal cancer cells. We have also shown that GSK-3 inhibition induced autophagy, likely as a result of imbalanced energy homeostasis caused by impaired glucose metabolism. Additionally, we have demonstrated the antitumor activity of 9-ING-41 in two different subcutaneous xenograft RCC tumor models. To our knowledge, this is the first report describing autophagy induction due to GSK-3 inhibition in renal cancer cells. PMID:24327518

  19. Induction of erythroid differentiation and modulation of gene expression by tiazofurin in K-562 leukemia cells.

    PubMed Central

    Olah, E; Natsumeda, Y; Ikegami, T; Kote, Z; Horanyi, M; Szelenyi, J; Paulik, E; Kremmer, T; Hollan, S R; Sugar, J

    1988-01-01

    Tiazofurin (2-beta-D-ribofuranosyl-4-thiazole-carboxamide; NSC 286193), an antitumor carbon-linked nucleoside that inhibits IMP dehydrogenase (IMP:NAD+ oxidoreductase; EC 1.1.1.205) and depletes guanylate levels, can activate the erythroid differentiation program of K-562 human leukemia cells. Tiazofurin-mediated cell differentiation is a multistep process. The inducer initiates early (less than 6 hr) metabolic changes that precede commitment to differentiation; among these early changes are decreases in IMP dehydrogenase activity and in GTP concentration, as well as alterations in the expression of certain protooncogenes (c-Ki-ras). K-562 cells do express commitment-i.e., cells exhibit differentiation without tiazofurin. Guanosine was effective in preventing the action of tiazofurin, thus providing evidence that the guanine nucleotides are critically involved in tiazofurin-initiated differentiation. Activation of transcription of the erythroid-specific gene that encodes A gamma-globin is a late (48 hr) but striking effect of tiazofurin. Down-regulation of the c-ras gene appears to be part of the complex process associated with tiazofurin-induced erythroid differentiation and relates to the perturbations of GTP metabolism. Images PMID:2901100

  20. Extracellular Signal-regulated Kinases (ERKs) Phosphorylate Lin28a Protein to Modulate P19 Cell Proliferation and Differentiation.

    PubMed

    Liu, Xiangyuan; Chen, Min; Li, Long; Gong, Liyan; Zhou, Hu; Gao, Daming

    2017-03-10

    Lin28a, originally discovered in the nematode Caenorhabditis elegans and highly conserved across species, is a well characterized regulator of let-7 microRNA (miRNA) and is implicated in cell proliferation and pluripotency control. However, little is known about how Lin28a function is modulated at the post-translational level and thereby responds to major signaling pathways. Here we show that Lin28a is directly phosphorylated by ERK1/2 kinases at Ser-200. By editing lin28a gene with the CRISPR/Cas9-based method, we generated P19 mouse embryonic carcinoma stem cells expressing Lin28a-S200A (phospho-deficient) and Lin28a-S200D (phospho-mimetic) mutants, respectively, to study the functional impact of Ser-200 phosphorylation. Lin28a-S200D-expressing cells, but not Lin28a-S200A-expressing or control P19 embryonic carcinoma cells, displayed impaired inhibition of let-7 miRNA and resulted in decreased cyclin D1, whereas Lin28a-S200A knock-in cells expressed less let-7 miRNA, proliferated faster, and exhibited differentiation defect upon retinoic acid induction. Therefore our results support that ERK kinase-mediated Lin28a phosphorylation may be an important mechanism for pluripotent cells to facilitate the escape from the self-renewal cycle and start the differentiation process.

  1. Human dendritic cells differentiated in hypoxia down-modulate antigen uptake and change their chemokine expression profile.

    PubMed

    Elia, Angela Rita; Cappello, Paola; Puppo, Maura; Fraone, Tiziana; Vanni, Cristina; Eva, Alessandra; Musso, Tiziana; Novelli, Francesco; Varesio, Luigi; Giovarelli, Mirella

    2008-12-01

    Dendritic cells (DCs) are the most potent antigen-presenting cells and fine-tune the immune response. We have investigated hypoxia's effects on the differentiation and maturation of DCs from human monocytes in vitro, and have shown that it affects DC functions. Hypoxic immature DCs (H-iDCs) significantly fail to capture antigens through down-modulation of the RhoA/Ezrin-Radixin-Moesin pathway and the expression of CD206. Moreover, H-iDCs released higher levels of CXCL1, VEGF, CCL20, CXCL8, and CXCL10 but decreased levels of CCL2 and CCL18, which predict a different ability to recruit neutrophils rather than monocytes and create a proinflammatory and proangiogenic environment. By contrast, hypoxia has no effect on DC maturation. Hypoxic mature DCs display a mature phenotype and activate both allogeneic and specific T cells like normoxic mDCs. This study provides the first demonstration that hypoxia inhibits antigen uptake by DCs and profoundly changes the DC chemokine expression profile and may have a critical role in DC differentiation, adaptation, and activation in inflamed tissues.

  2. Ski inhibits TGF-β/phospho-Smad3 signaling and accelerates hypertrophic differentiation in chondrocytes.

    PubMed

    Kim, Kyung-Ok; Sampson, Erik R; Maynard, Robert D; O'Keefe, Regis J; Chen, Di; Drissi, Hicham; Rosier, Randy N; Hilton, Matthew J; Zuscik, Michael J

    2012-06-01

    Since transforming growing factor-β (TGF-β)/Smad signaling inhibits chondrocyte maturation, endogenous negative regulators of TGF-β signaling are likely also important regulators of the chondrocyte differentiation process. One such negative regulator, Ski, is an oncoprotein that is known to inhibit TGF-β/Smad3 signaling via its interaction with phospho-Smad3 and recruitment of histone deacetylases (HDACs) to the DNA binding complex. Based on this, we hypothesized that Ski inhibits TGF-β signaling and accelerates maturation in chondrocytes via recruitment of HDACs to transcriptional complexes containing Smads. We tested this hypothesis in chick upper sternal chondrocytes (USCs), where gain and loss of Ski expression experiments were performed. Over-expression of Ski not only reversed the inhibitory effect of TGF-β on the expression of hypertrophic marker genes such as type X collagen (colX) and osteocalcin, it induced these genes basally as well. Conversely, knockdown of Ski by RNA interference led to a reduction of colX and osteocalcin expression under basal conditions. Furthermore, Ski blocked TGF-β induction of cyclinD1 and caused a basal up-regulation of Runx2, consistent with the observed acceleration of hypertrophy. Regarding mechanism, not only does Ski associate with phospho-Smad2 and 3, but its association with phospho-Smad3 is required for recruitment of HDAC4 and 5. Implicating this recruitment of HDACs in the phenotypic effects of Ski in chondrocytes, the HDAC inhibitor SAHA reversed the up-regulation of colX and osteocalcin in Ski over-expressing cells. These results suggest that inhibition of TGF-β signaling by Ski, which involves its association with phospho-Smad3 and recruitment of HDAC4 and 5, leads to accelerated chondrocyte differentiation.

  3. GDF11 decreases bone mass by stimulating osteoclastogenesis and inhibiting osteoblast differentiation

    PubMed Central

    Liu, Weiqing; Zhou, Liyan; Zhou, Chenchen; Zhang, Shiwen; Jing, Junjun; Xie, Liang; Sun, Ningyuan; Duan, Xiaobo; Jing, Wei; Liang, Xing; Zhao, Hu; Ye, Ling; Chen, Qianming; Yuan, Quan

    2016-01-01

    Osteoporosis is an age-related disease that affects millions of people. Growth differentiation factor 11 (GDF11) is a secreted member of the transforming growth factor beta (TGF-β) superfamily. Deletion of Gdf11 has been shown to result in a skeletal anterior–posterior patterning disorder. Here we show a role for GDF11 in bone remodelling. GDF11 treatment leads to bone loss in both young and aged mice. GDF11 inhibits osteoblast differentiation and also stimulates RANKL-induced osteoclastogenesis through Smad2/3 and c-Fos-dependent induction of Nfatc1. Injection of GDF11 impairs bone regeneration in mice and blocking GDF11 function prevents oestrogen-deficiency-induced bone loss and ameliorates age-related osteoporosis. Our data demonstrate that GDF11 is a previously unrecognized regulator of bone remodelling and suggest that GDF11 is a potential target for treatment of osteoporosis. PMID:27653144

  4. Radiometric selective inhibition tests for differentiation of Mycobacterium tuberculosis, Mycobacterium bovis, and other mycobacteria.

    PubMed Central

    Gross, W M; Hawkins, J E

    1985-01-01

    In the context of a busy reference laboratory, radiometric selective inhibition tests were evaluated for rapid differentiation of Mycobacterium tuberculosis and Mycobacterium bovis and of the M. tuberculosis complex from other mycobacteria. p-Nitro-alpha-acetylamino-beta-hydroxypropiophenone at 5 micrograms and hydroxylamine hydrochloride at 62.5 and 125 micrograms per ml of 7H12 medium were used to separate the M. tuberculosis complex from other mycobacteria (MOTT bacilli). Since it is important epidemiologically to distinguish M. tuberculosis from M. bovis, susceptibility to 1 microgram of thiophene-2-carboxylic acid per ml was also determined radiometrically. By using these three agents as selective inhibitors, M. tuberculosis, M. bovis, and MOTT bacilli were differentiated with a high degree of specificity by a BACTEC radiometric procedure. Results of tests performed on clinical isolates submitted on solid medium to our reference laboratory were available within 5 days. PMID:3921561

  5. Fibroblast growth factor 2 inhibits up-regulation of bone morphogenic proteins and their receptors during osteoblastic differentiation of human mesenchymal stem cells

    SciTech Connect

    Biver, Emmanuel; Soubrier, Anne-Sophie; Thouverey, Cyril; Cortet, Bernard; Broux, Odile; Caverzasio, Joseph; Hardouin, Pierre

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer FGF modulates BMPs pathway in HMSCs by down-regulating BMP/BMPR expression. Black-Right-Pointing-Pointer This effect is mediated by ERK and JNK MAPKs pathways. Black-Right-Pointing-Pointer Crosstalk between FGF and BMPs must be taken into account in skeletal bioengineering. Black-Right-Pointing-Pointer It must also be considered in the use of recombinant BMPs in orthopedic and spine surgeries. -- Abstract: Understanding the interactions between growth factors and bone morphogenic proteins (BMPs) signaling remains a crucial issue to optimize the use of human mesenchymal stem cells (HMSCs) and BMPs in therapeutic perspectives and bone tissue engineering. BMPs are potent inducers of osteoblastic differentiation. They exert their actions via BMP receptors (BMPR), including BMPR1A, BMPR1B and BMPR2. Fibroblast growth factor 2 (FGF2) is expressed by cells of the osteoblastic lineage, increases their proliferation and is secreted during the healing process of fractures or in surgery bone sites. We hypothesized that FGF2 might influence HMSC osteoblastic differentiation by modulating expressions of BMPs and their receptors. BMP2, BMP4, BMPR1A and mainly BMPR1B expressions were up-regulated during this differentiation. FGF2 inhibited HMSCs osteoblastic differentiation and the up-regulation of BMPs and BMPR. This effect was prevented by inhibiting the ERK or JNK mitogen-activated protein kinases which are known to be activated by FGF2. These data provide a mechanism explaining the inhibitory effect of FGF2 on osteoblastic differentiation of HMSCs. These crosstalks between growth and osteogenic factors should be considered in the use of recombinant BMPs in therapeutic purpose of fracture repair or skeletal bioengineering.

  6. Differential pulse amplitude modulation for multiple-input single-output OWVLC

    NASA Astrophysics Data System (ADS)

    Yang, S. H.; Kwon, D. H.; Kim, S. J.; Son, Y. H.; Han, S. K.

    2015-01-01

    White light-emitting diodes (LEDs) are widely used for lighting due to their energy efficiency, eco-friendly, and small size than previously light sources such as incandescent, fluorescent bulbs and so on. Optical wireless visible light communication (OWVLC) based on LED merges lighting and communications in applications such as indoor lighting, traffic signals, vehicles, and underwater communications because LED can be easily modulated. However, physical bandwidth of LED is limited about several MHz by slow time constant of the phosphor and characteristics of device. Therefore, using the simplest modulation format which is non-return-zero on-off-keying (NRZ-OOK), the data rate reaches only to dozens Mbit/s. Thus, to improve the transmission capacity, optical filtering and pre-, post-equalizer are adapted. Also, high-speed wireless connectivity is implemented using spectrally efficient modulation methods: orthogonal frequency division multiplexing (OFDM) or discrete multi-tone (DMT). However, these modulation methods need additional digital signal processing such as FFT and IFFT, thus complexity of transmitter and receiver is increasing. To reduce the complexity of transmitter and receiver, we proposed a novel modulation scheme which is named differential pulse amplitude modulation. The proposed modulation scheme transmits different NRZ-OOK signals with same amplitude and unit time delay using each LED chip, respectively. The `N' parallel signals from LEDs are overlapped and directly detected at optical receiver. Received signal is demodulated by power difference between unit time slots. The proposed scheme can overcome the bandwidth limitation of LEDs and data rate can be improved according to number of LEDs without complex digital signal processing.

  7. Inhibition of hyaluronan synthesis alters sulfated glycosaminoglycans deposition during chondrogenic differentiation in ATDC5 cells.

    PubMed

    Yoshioka, Yutaka; Kozawa, Eiji; Urakawa, Hiroshi; Arai, Eisuke; Futamura, Naohisa; Zhuo, Lisheng; Kimata, Koji; Ishiguro, Naoki; Nishida, Yoshihiro

    2015-08-01

    In chondrogenic differentiation, expression and collaboration of specific molecules, such as aggrecan and type II collagen, in extracellular matrix (ECM) are crucial. However, few studies have clarified the roles of hyaluronan (HA) in proteoglycan aggregation during chondrogenic differentiation. We assessed the roles of HA in sulfated glycosaminoglycans deposition during chondrogenic differentiation by means of 4-methylumbelliferone (4-MU), an HA synthase inhibitor, using ATDC5 cells. ATDC5 cells were treated with 0.5 mM 4-MU for 7 or 21 days after induction of chondrogenic differentiation with insulin. Depositions of sulfated glycosaminoglycans were evaluated with Alcian blue staining. mRNA expression of ECM molecules was determined using real-time RT-PCR. The deposition of aggrecan and versican was investigated with immunohistochemical staining using specific antibodies. Effects of 4-MU on HA concentrations were analyzed by HA binding assay. 4-MU suppressed the positivity of Alcian blue staining, although this delay was reversible. Interestingly, stronger positivity of Alcian blue staining was observed at day 21 in cultures with 4-MU discontinuation than in the control. 4-MU significantly increased the mRNA expression of aggrecan, versican, and type II collagen, which was consistent with increased deposition of aggrecan and versican. The HA concentration in ECM and cell-associated region was significantly suppressed with 4-MU treatment. We conclude that the inhibition of HA synthesis slows sulfated glycosaminoglycans deposition during chondrogenic differentiation despite the increased deposition of other ECM molecules. Transient starvation of HA with 4-MU accelerates chondrogenic ECM formation, suggesting its potential to stimulate chondrogenic differentiation with adequate use.

  8. Neuronal correlates and serotonergic modulation of behavioural inhibition and reward in healthy and antisocial individuals.

    PubMed

    Völlm, Birgit; Richardson, Paul; McKie, Shane; Reniers, Renate; Elliott, Rebecca; Anderson, Ian M; Williams, Steve; Dolan, Mairead; Deakin, Bill

    2010-02-01

    Individuals with antisocial personality disorder (ASPD) are impulsive and show impairment in reinforcement processing. There is increasing evidence for a neurobiological basis of psychopathy, which shares some of the characteristics of ASPD, but research on the neuronal correlates of neuropsychological processes in ASPD remains limited. Furthermore, no research has examined the effects of serotonergic manipulation on brain activations in antisocial groups. In this study, 25 male participants with ASPD (mean age 42.1) and 32 male control participants (mean age 30.5; 25 participants providing usable scans) were randomly allocated to receive the 5-HT(2C)-agonist mCPP or placebo. Participants were scanned using functional magnetic resonance imaging (fMRI) during a behavioural inhibition (Go/NoGo) and a reward task. In comparison to healthy controls the ASPD group showed reduced task related activations in the dorsolateral prefrontal cortex (DLPFC) but increased signal in the pre/subgenual anterior cingulate cortex (ACC) in the Go/No-Go task and increased activation in OFC in the reward task. mCPP modulated brain responses in both tasks in the whole group. Interactions between group and drug occured in bilateral OFC, caudate and ventral pallidum during the reward task but no significant interactions were found in the Go/No-Go task. This suggests that ASPD involves altered serotonin modulation of reward, but not motor inhibition pathways. These findings suggest that ASPD involves altered DLPFC, ACC and OFC function. Altered serotonergic modulation of reward pathways seen in the ASPD group raises the possibility that targeting serotonin systems may be therapeutic.

  9. Rab8 Interacts with Distinct Motifs in α2B- and β2-Adrenergic Receptors and Differentially Modulates Their Transport*

    PubMed Central

    Dong, Chunmin; Yang, Lingling; Zhang, Xiaoping; Gu, Hua; Lam, May L.; Claycomb, William C.; Xia, Houhui; Wu, Guangyu

    2010-01-01

    The molecular mechanism underlying the post-Golgi transport of G protein-coupled receptors (GPCRs) remains poorly understood. Here we determine the role of Rab8 GTPase, which modulates vesicular protein transport between the trans-Golgi network (TGN) and the plasma membrane, in the cell surface targeting of α2B- and β2-adrenergic receptors (AR). Transient expression of GDP- and GTP-bound Rab8 mutants and short hairpin RNA-mediated knockdown of Rab8 more potently inhibited the cell surface expression of α2B-AR than β2-AR. The GDP-bound Rab8(T22N) mutant attenuated ERK1/2 activation by α2B-AR, but not β2-AR, and arrested α2B-AR in the TGN compartment. Co-immunoprecipitation revealed that both α2B-AR and β2-AR physically interacted with Rab8 and glutathione S-transferase fusion protein pulldown assays demonstrated that Rab8 interacted with the C termini of both receptors. Interestingly, mutation of the highly conserved membrane-proximal C terminus dileucine motif selectively blocked β2-AR interaction with Rab8, whereas mutation of residues Val431-Phe432-Asn433-Gln434, Pro447-Trp448, Gln450-Thr451, and Trp453 in the C terminus impaired α2B-AR interaction with Rab8. Furthermore, transport inhibition by Rab8(T22N) of a chimeric β2-AR carrying the α2B-AR C terminus was similar to α2B-AR. These data provide strong evidence indicating that Rab8 GTPase interacts with distinct motifs in the C termini of α2B-AR and β2-AR and differentially modulates their traffic from the TGN to the cell surface. PMID:20424170

  10. Inhibition of Sirt1 promotes neural progenitors toward motoneuron differentiation from human embryonic stem cells

    SciTech Connect

    Zhang, Yun; Wang, Jing; Chen, Guian; Fan, Dongsheng; Deng, Min

    2011-01-14

    Research highlights: {yields} Nicotinamide inhibit Sirt1. {yields} MASH1 and Ngn2 activation. {yields} Increase the expression of HB9. {yields} Motoneurons formation increases significantly. -- Abstract: Several protocols direct human embryonic stem cells (hESCs) toward differentiation into functional motoneurons, but the efficiency of motoneuron generation varies based on the human ESC line used. We aimed to develop a novel protocol to increase the formation of motoneurons from human ESCs. In this study, we tested a nuclear histone deacetylase protein, Sirt1, to promote neural precursor cell (NPC) development during differentiation of human ESCs into motoneurons. A specific inhibitor of Sirt1, nicotinamide, dramatically increased motoneuron formation. We found that about 60% of the cells from the total NPCs expressed HB9 and {beta}III-tubulin, commonly used motoneuronal markers found in neurons derived from ESCs following nicotinamide treatment. Motoneurons derived from ESC expressed choline acetyltransferase (ChAT), a positive marker of mature motoneuron. Moreover, we also examined the transcript levels of Mash1, Ngn2, and HB9 mRNA in the differentiated NPCs treated with the Sirt1 activator resveratrol (50 {mu}M) or inhibitor nicotinamide (100 {mu}M). The levels of Mash1, Ngn2, and HB9 mRNA were significantly increased after nicotinamide treatment compared with control groups, which used the traditional protocol. These results suggested that increasing Mash1 and Ngn2 levels by inhibiting Sirt1 could elevate HB9 expression, which promotes motoneuron differentiation. This study provides an alternative method for the production of transplantable motoneurons, a key requirement in the development of hESC-based cell therapy in motoneuron disease.

  11. Interleukin-6 inhibits early differentiation of ATDC5 chondrogenic progenitor cells.

    PubMed

    Nakajima, Shoko; Naruto, Takuya; Miyamae, Takako; Imagawa, Tomoyuki; Mori, Masaaki; Nishimaki, Shigeru; Yokota, Shumpei

    2009-08-01

    Interleukin (IL)-6 is a causative agent of systemic juvenile idiopathic arthritis (sJIA), a chronic inflammatory disease complicated with severe growth impairment. Recent trials of anti-IL-6 receptor monoclonal antibody, tocilizumab, indicated that tocilizumab blocks IL-6/IL-6 receptor-mediated inflammation, and induces catch-up growth in children with sJIA. This study evaluates the effects of IL-6 on chondrogenesis by ATDC5 cells, a clonal murine chondrogenic cell line that provides an excellent model for studying endochondral ossification at growth plate. ATDC5 cells were examined for the expression of IL-6 receptor and gp130 by fluorescence-activated cell sorting analysis. Recombinant murine IL-6 was added to ATDC5 cultures to observe cell differentiation, using a quantitative RT-PCR for the chondrogenic differentiation markers type II collagen, aggrecan, and type X collagen. To block IL-6, the anti-mouse IL-6 receptor monoclonal antibody MR16-1 was added. As a result, the cells expressed IL-6 receptor and gp130. The expression of chondrogenic differentiation marker gene was reduced by IL-6, but this was abrogated by MR16-1. We conclude that IL-6 inhibits early chondrogenesis of ATDC5 cells suggesting that IL-6 may affect committed stem cells at a cellular level during chondrogenic differentiation of growth plate chondrocytes, and that IL-6 may be a cellular-level factor in growth impairment in sJIA.

  12. Inhibition of Ape1 Redox Activity Promotes Odonto/osteogenic Differentiation of Dental Papilla Cells

    PubMed Central

    Chen, Tian; Liu, Zhi; Sun, Wenhua; Li, Jingyu; Liang, Yan; Yang, Xianrui; Xu, Yang; Yu, Mei; Tian, Weidong; Chen, Guoqing; Bai, Ding

    2015-01-01

    Dentinogenesis is the formation of dentin, a substance that forms the majority of teeth, and this process is performed by odontoblasts. Dental papilla cells (DPCs), as the progenitor cells of odontoblasts, undergo the odontogenic differentiation regulated by multiple cytokines and paracrine signal molecules. Ape1 is a perfect paradigm of the function complexity of a biological macromolecule with two major functional regions for DNA repair and redox regulation, respectively. To date, it remains unclear whether Ape1 can regulate the dentinogenesis in DPCs. In the present study, we firstly examed the spatio-temporal expression of Ape1 during tooth germ developmental process, and found the Ape1 expression was initially high and then gradually reduced along with the tooth development. Secondly, the osteo/odontogenic differentiation capacity of DPCs was up-regulated when treated with either Ape1-shRNA or E3330 (a specific inhibitor of the Ape1 redox function), respectively. Moreover, we found that the canonical Wnt signaling pathway was activated in this process, and E3330 reinforced-osteo/odontogenic differentiation capacity was suppressed by Dickkopf1 (DKK1), a potent antagonist of canonical Wnt signaling pathway. Taken together, we for the first time showed that inhibition of Ape1 redox regulation could promote the osteo/odontogenic differentiation capacity of DPCs via canonical Wnt signaling pathway. PMID:26639148

  13. Aorta-derived mesoangioblasts differentiate into the oligodendrocytes by inhibition of the Rho kinase signaling pathway.

    PubMed

    Wang, Lei; Kamath, Anant; Frye, Janie; Iwamoto, Gary A; Chun, Ju Lan; Berry, Suzanne E

    2012-05-01

    Mesoangioblasts are vessel-derived stem cells that differentiate into mesodermal derivatives. We have isolated postnatal aorta-derived mesoangioblasts (ADMs) that differentiate into smooth, skeletal, and cardiac muscle, and adipocytes, and regenerate damaged skeletal muscle in a murine model for Duchenne muscular dystrophy. We report that the marker profile of ADM is similar to that of mesoangioblasts isolated from embryonic dorsal aorta, postnatal bone marrow, and heart, but distinct from mesoangioblasts derived from skeletal muscle. We also demonstrate that ADM differentiate into myelinating glial cells. ADM localize to peripheral nerve bundles in regenerating muscles and exhibit morphology and marker expression of mature Schwann cells, and myelinate axons. In vitro, ADM spontaneously express markers of oligodendrocyte progenitors, including the chondroitin sulphate proteoglycan NG2, nestin, platelet-derived growth factor (PDGF) receptor α, the A2B5 antigen, thyroid hormone nuclear receptor α, and O4. Pharmacological inhibition of Rho kinase (ROCK) initiated process extension by ADM, and when combined with insulin-like growth factor 1, PDGF, and thyroid hormone, enhanced ADM expression of oligodendrocyte precursor markers and maturation into the oligodendrocyte lineage. ADM injected into the right lateral ventricle of the brain migrate to the corpus callosum, and cerebellar white matter, where they express components of myelin. Because ADM differentiate or mature into cell types of both mesodermal and ectodermal origin, they may be useful for treatment of a variety of degenerative diseases, or repair and regeneration of multiple cell types in severely damaged tissue.

  14. Perceived state of self during motion can differentially modulate numerical magnitude allocation.

    PubMed

    Arshad, Q; Nigmatullina, Y; Roberts, R E; Goga, U; Pikovsky, M; Khan, S; Lobo, R; Flury, A-S; Pettorossi, V E; Cohen-Kadosh, R; Malhotra, P A; Bronstein, A M

    2016-09-01

    Although a direct relationship between numerical allocation and spatial attention has been proposed, recent research suggests that these processes are not directly coupled. In keeping with this, spatial attention shifts induced either via visual or vestibular motion can modulate numerical allocation in some circumstances but not in others. In addition to shifting spatial attention, visual or vestibular motion paradigms also (i) elicit compensatory eye movements which themselves can influence numerical processing and (ii) alter the perceptual state of 'self', inducing changes in bodily self-consciousness impacting upon cognitive mechanisms. Thus, the precise mechanism by which motion modulates numerical allocation remains unknown. We sought to investigate the influence that different perceptual experiences of motion have upon numerical magnitude allocation while controlling for both eye movements and task-related effects. We first used optokinetic visual motion stimulation (OKS) to elicit the perceptual experience of either 'visual world' or 'self'-motion during which eye movements were identical. In a second experiment, we used a vestibular protocol examining the effects of perceived and subliminal angular rotations in darkness, which also provoked identical eye movements. We observed that during the perceptual experience of 'visual world' motion, rightward OKS-biased judgments towards smaller numbers, whereas leftward OKS-biased judgments towards larger numbers. During the perceptual experience of 'self-motion', judgments were biased towards larger numbers irrespective of the OKS direction. Contrastingly, vestibular motion perception was found not to modulate numerical magnitude allocation, nor was there any differential modulation when comparing 'perceived' vs. 'subliminal' rotations. We provide a novel demonstration that numerical magnitude allocation can be differentially modulated by the perceptual state of self during visual but not vestibular mediated motion.

  15. BAP1 inhibits the ER stress gene regulatory network and modulates metabolic stress response.

    PubMed

    Dai, Fangyan; Lee, Hyemin; Zhang, Yilei; Zhuang, Li; Yao, Hui; Xi, Yuanxin; Xiao, Zhen-Dong; You, M James; Li, Wei; Su, Xiaoping; Gan, Boyi

    2017-03-21

    The endoplasmic reticulum (ER) is classically linked to metabolic homeostasis via the activation of unfolded protein response (UPR), which is instructed by multiple transcriptional regulatory cascades. BRCA1 associated protein 1 (BAP1) is a tumor suppressor with de-ubiquitinating enzyme activity and has been implicated in chromatin regulation of gene expression. Here we show that BAP1 inhibits cell death induced by unresolved metabolic stress. This prosurvival role of BAP1 depends on its de-ubiquitinating activity and correlates with its ability to dampen the metabolic stress-induced UPR transcriptional network. BAP1 inhibits glucose deprivation-induced reactive oxygen species and ATP depletion, two cellular events contributing to the ER stress-induced cell death. In line with this, Bap1 KO mice are more sensitive to tunicamycin-induced renal damage. Mechanically, we show that BAP1 represses metabolic stress-induced UPR and cell death through activating transcription factor 3 (ATF3) and C/EBP homologous protein (CHOP), and reveal that BAP1 binds to ATF3 and CHOP promoters and inhibits their transcription. Taken together, our results establish a previously unappreciated role of BAP1 in modulating the cellular adaptability to metabolic stress and uncover a pivotal function of BAP1 in the regulation of the ER stress gene-regulatory network. Our study may also provide new conceptual framework for further understanding BAP1 function in cancer.

  16. BAP1 inhibits the ER stress gene regulatory network and modulates metabolic stress response

    PubMed Central

    Dai, Fangyan; Lee, Hyemin; Zhang, Yilei; Zhuang, Li; Yao, Hui; Xi, Yuanxin; Xiao, Zhen-Dong; You, M. James; Li, Wei; Su, Xiaoping; Gan, Boyi

    2017-01-01

    The endoplasmic reticulum (ER) is classically linked to metabolic homeostasis via the activation of unfolded protein response (UPR), which is instructed by multiple transcriptional regulatory cascades. BRCA1 associated protein 1 (BAP1) is a tumor suppressor with de-ubiquitinating enzyme activity and has been implicated in chromatin regulation of gene expression. Here we show that BAP1 inhibits cell death induced by unresolved metabolic stress. This prosurvival role of BAP1 depends on its de-ubiquitinating activity and correlates with its ability to dampen the metabolic stress-induced UPR transcriptional network. BAP1 inhibits glucose deprivation-induced reactive oxygen species and ATP depletion, two cellular events contributing to the ER stress-induced cell death. In line with this, Bap1 KO mice are more sensitive to tunicamycin-induced renal damage. Mechanically, we show that BAP1 represses metabolic stress-induced UPR and cell death through activating transcription factor 3 (ATF3) and C/EBP homologous protein (CHOP), and reveal that BAP1 binds to ATF3 and CHOP promoters and inhibits their transcription. Taken together, our results establish a previously unappreciated role of BAP1 in modulating the cellular adaptability to metabolic stress and uncover a pivotal function of BAP1 in the regulation of the ER stress gene-regulatory network. Our study may also provide new conceptual framework for further understanding BAP1 function in cancer. PMID:28275095

  17. Metabotropic glutamate subtype 5 receptors modulate fear-conditioning induced enhancement of prepulse inhibition in rats.

    PubMed

    Zou, Dan; Huang, Juan; Wu, Xihong; Li, Liang

    2007-02-01

    Non-startling acoustic events presented shortly before an intense startling sound can inhibit the acoustic startle reflex. This phenomenon is called prepulse inhibition (PPI), and is widely used as a model of sensorimotor gating. The present study investigated whether PPI can be modulated by fear conditioning, whose acquisition can be blocked by the specific antagonist of metabotropic glutamate receptors subtype 5 (mGluR5), 2-methyl-6-(phenylethynyl)-pyridine (MPEP). The results show that a gap embedded in otherwise continuous noise sounds, which were delivered by two spatially separated loudspeakers, could inhibit the startle reflex induced by an intense sound that was presented 50 ms after the gap. The inhibitory effect depended on the duration of the gap, and was enhanced by fear conditioning that was introduced by temporally pairing the gap with footshock. Intraperitoneal injection of MPEP (0.5 or 5mg/kg) 30 min before fear conditioning blocked the enhancing effect of fear conditioning on PPI, but did not affect either the baseline startle magnitude or PPI if no fear conditioning was introduced. These results indicate that PPI is enhanced when the prepulse signifies an aversive event after fear conditioning. Also, mGlu5Rs play a role in preserving the fear-conditioning-induced enhancement of PPI.

  18. Alzheimer's Associated β-Amyloid Protein Inhibits Influenza A Virus and Modulates Viral Interactions with Phagocytes

    PubMed Central

    White, Mitchell R.; Kandel, Ruth; Tripathi, Shweta; Condon, David; Qi, Li; Taubenberger, Jeffrey; Hartshorn, Kevan L.

    2014-01-01

    Accumulation of β-Amyloid (βA) is a key pathogenetic factor in Alzheimer's disease; however, the normal function of βA is unknown. Recent studies have shown that βA can inhibit growth of bacteria and fungi. In this paper we show that βA also inhibits replication of seasonal and pandemic strains of H3N2 and H1N1 influenza A virus (IAV) in vitro. The 42 amino acid fragment of βA (βA42) had greater activity than the 40 amino acid fragment. Direct incubation of the virus with βA42 was needed to achieve optimal inhibition. Using quantitative PCR assays βA42 was shown to reduce viral uptake by epithelial cells after 45 minutes and to reduce supernatant virus at 24 hours post infection. βA42 caused aggregation of IAV particles as detected by light transmission assays and electron and confocal microscopy. βA42 did not stimulate neutrophil H2O2 production or extracellular trap formation on its own, but it increased both responses stimulated by IAV. In addition, βA42 increased uptake of IAV by neutrophils. βA42 reduced viral protein synthesis in monocytes and reduced IAV-induced interleukin-6 production by these cells. Hence, we demonstrate for the first time that βA has antiviral activity and modulates viral interactions with phagocytes. PMID:24988208

  19. Gαq Regulates the Development of Rheumatoid Arthritis by Modulating Th1 Differentiation

    PubMed Central

    Wang, Dashan; Liu, Yuan; Li, Yan; Zhang, Jiyun

    2017-01-01

    The Gαq-containing G protein, an important member of Gq/11 class, is ubiquitously expressed in mammalian cells. Gαq has been found to play an important role in immune regulation and development of autoimmune disease such as rheumatoid arthritis (RA). However, how Gαq participates in the pathogenesis of RA is still not fully understood. In the present study, we aimed to find out whether Gαq controls RA via regulation of Th1 differentiation. We observed that the expression of Gαq was negatively correlated with the expression of signature Th1 cytokine (IFN-γ) in RA patients, which suggests a negative role of Gαq in differentiation of Th1 cells. By using Gαq knockout (Gnaq−/−) mice, we demonstrated that loss of Gαq led to enhanced Th1 cell differentiation. Gαq negative regulated the differentiation of Th1 cell by modulating the expression of T-bet and the activity of STAT4. Furthermore, we detected the increased ratio of Th1 cells in Gnaq−/− bone marrow (BM) chimeras spontaneously developing inflammatory arthritis. In conclusion, results presented in the study demonstrate that loss of Gαq promotes the differentiation of Th1 cells and contributes to the pathogenesis of RA. PMID:28197018

  20. IL-21 Receptor Antagonist Inhibits Differentiation of B Cells toward Plasmablasts upon Alloantigen Stimulation

    PubMed Central

    de Leur, Kitty; Dor, Frank J. M. F.; Dieterich, Marjolein; van der Laan, Luc J. W.; Hendriks, Rudi W.; Baan, Carla C.

    2017-01-01

    Interaction between T follicular helper (Tfh) cells and B cells is complex and involves various pathways, including the production of IL-21 by the Tfh cells. Secretion of IL-21 results in B cell differentiation toward immunoglobulin-producing plasmablasts. In patients after kidney transplantation, the formation of alloantibodies produced by donor antigen-activated B cells are a major cause of organ failure. In this allogeneic response, the role of IL-21-producing Tfh cells that regulate B cell differentiation is unknown. Here, we tested, in an alloantigen-driven setting, whether Tfh cell help signals control B cell differentiation with its dependency on IL-21. Pre-transplantation patient PBMCs were sorted into pure CD4posCXCR5pos Tfh cells and CD19posCD27pos memory B cells and stimulated with donor antigen in the presence or absence of an IL-21 receptor (IL-21R) antagonist (αIL-21R). Donor antigen stimulation initiated expression of the activation markers inducible co-stimulator (ICOS) and programmed death 1 (PD-1) on Tfh cells and a shift toward a mixed Tfh2 and Tfh17 phenotype. The memory B cells underwent class switch recombination and differentiated toward IgM- and IgG-producing plasmablasts. In the presence of αIL-21R, a dose-dependent inhibition of STAT3 phosphorylation was measured in both T and B cells. Blockade of the IL-21R did not have an effect on PD-1 and ICOS expression on Tfh cells but significantly inhibited B cell differentiation. The proportion of plasmablasts decreased by 78% in the presence of αIL-21R. Moreover, secreted IgM and IgG2 levels were significantly lower in the presence of αIL-21R. In conclusion, our results demonstrate that IL-21 produced by alloantigen-activated Tfh cells controls B cell differentiation toward antibody producing plasmablasts. The IL-21R might, therefore, be a useful target in organ transplantation to prevent antigen-driven immune responses leading to graft failure. PMID:28373876

  1. Tenascin-W inhibits proliferation and differentiation of preosteoblasts during endochondral bone formation

    SciTech Connect

    Kimura, Hiroaki; Akiyama, Haruhiko . E-mail: hakiyama@kuhp.kyoto-u.ac.jp; Nakamura, Takashi; Crombrugghe, Benoit de

    2007-05-18

    We identified a cDNA encoding mouse Tenascin-W (TN-W) upregulated by bone morphogenetic protein (Bmp)2 in ATDC5 osteo-chondroprogenitors. In adult mice, TN-W was markedly expressed in bone. In mouse embryos, during endochondral bone formation TN-W was localized in perichondrium/periosteum, but not in trabecular and cortical bones. During bone fracture repair, cells in the newly formed perichondrium/periosteum surrounding the cartilaginous callus expressed TN-W. Furthermore, TN-W was detectable in perichondrium/periosteum of Runx2-null and Osterix-null embryos, indicating that TN-W is expressed in preosteoblasts. In CFU-F and -O cells, TN-W had no effect on initiation of osteogenesis of bone marrow cells, and in MC3T3-E1 osteoblastic cells TN-W inhibited cell proliferation and Col1a1 expression. In addition, TN-W suppressed canonical Wnt signaling which stimulates osteoblastic differentiation. Our results indicate that TN-W is a novel marker of preosteoblasts in early stage of osteogenesis, and that TN-W inhibits cell proliferation and differentiation of preosteoblasts mediated by canonical Wnt signaling.

  2. Hydrogen sulfide inhibits the calcification and osteoblastic differentiation of vascular smooth muscle cells

    PubMed Central

    Zavaczki, Erzsébet; Jeney, Viktória; Agarwal, Anupam; Zarjou, Abolfazl; Oros, Melinda; Katkó, Mónika; Varga, Zsuzsa; Balla, György; Balla, József

    2011-01-01

    Osteoblastic differentiation of vascular smooth muscle cells (VSMCs) is involved in the pathogenesis of vascular calcification. Hydrogen sulfide (H2S) is a gas endogenously produced by cystathionine γ-lyase in VSMC. Here we determined whether H2S plays a role in phosphate-induced osteoblastic transformation and mineralization of VSMC. Hydrogen sulfide was found to inhibit calcium deposition in the extracellular matrix and to suppress the induction of the genes involved in osteoblastic transformation of VSMC: alkaline phosphatase, osteocalcin, and Cbfa1. Moreover, phosphate uptake and phosphate-triggered upregulation of the sodium-dependent phosphate cotransporter (Pit-1) were also prevented by H2S. Reduction of endogenous production of H2S by inhibition of cystathionine γ-lyase activity resulted in increased osteoblastic transformation and mineralization. Low plasma levels of H2S, associated with decreased cystathionine γ-lyase enzyme activity, were found in patients with chronic kidney disease receiving hemodialysis. Thus, H2S is a potent inhibitor of phosphate-induced calcification and osteoblastic differentiation of VSMC. This mechanism might contribute to accelerated vascular calcification in chronic kidney disease. PMID:21716261

  3. Meteorin-Like Shows Unique Expression Pattern in Bone and Its Overexpression Inhibits Osteoblast Differentiation

    PubMed Central

    Gong, Weiyan; Liu, Yong; Wu, Zhihong; Wang, Shaohai; Qiu, Guixing; Lin, Shouqing

    2016-01-01

    The present study was performed to identify and characterize genes involved in osteoblasts function. Firstly, we constructed and sequenced a human osteoblast full-length cDNA library to screen for genes whose functions have not been reported and further identify these candidate genes through detecting the relationship with the activator protein-1 (AP-1) transcription factor complex using a dual luciferase reporter system. Only one gene, namely METRNL (Meteorin, glial cell differentiation regulator-like) has been screened out. We performed immunohistochemistry to analyze expression patterns in bone and established a stable transfection MG63 cell line of METRNL-EGFP fusion protein overexpression to analyze the function of METRNL in mineralized nodule formation. Immunohistochemistry showed METRNL expression in hypertrophic chondrocytes and osteoblasts lining trabecular bone surfaces. Overexpression of METRNL inhibited mineralized nodule formation by the MG63 osteosarcoma cell line. Thus, the identified gene, METRNL, which is associated with AP-1 transcription factor complex activity, has a unique expression pattern in bone. In addition, the anomalous expression of METRNL may inhibit bone cell differentiation. PMID:27716826

  4. (-)-Epigallocatechin gallate inhibition of osteoclastic differentiation via NF-{kappa}B

    SciTech Connect

    Lin, R.-W.; Chen, C.-H.; Wang, Y.-H.; Ho, M.-L.; Hung, S.-H.; Chen, I.-S. Wang, G.-J.

    2009-02-20

    People who regularly drink tea have been found to have a higher bone mineral density (BMD) and to be at less risk of hip fractures than those who do not drink it. Green tea catechins such as (-)-epigallocatechin gallate (EGCG) have been reported to increase osteogenic functioning in mesenchymal stem cells. However, its effect on osteoclastogenesis remains unclear. In this study, we investigated the effect of EGCG on RANKL-activation osteoclastogenesis and NF-{kappa}B in RAW 264.7, a murine preosteoclast cell line. EGCG (10-100 {mu}M) significantly suppressed the RANKL-induced differentiation of osteoclasts and the formation of pits in murine RAW 264.7 cells and bone marrow macrophages (BMMs). EGCG appeared to target osteoclastic differentiation at an early stage but had no cytotoxic effect on osteoclast precursors. In addition, it significantly inhibited RANKL-induced NF-{kappa}B transcriptional activity and nuclear translocation. We conclude that EGCG inhibits osteoclastogenesis through its activation of NF-{kappa}B.

  5. Suppressor of Cytokine Signaling 2 Negatively Regulates NK Cell Differentiation by Inhibiting JAK2 Activity

    PubMed Central

    Kim, Won Sam; Kim, Mi Jeong; Kim, Dong Oh; Byun, Jae-Eun; Huy, Hangsak; Song, Hae Young; Park, Young-Jun; Kim, Tae-Don; Yoon, Suk Ran; Choi, Eun-Ji; Jung, Haiyoung; Choi, Inpyo

    2017-01-01

    Suppressor of cytokine signaling (SOCS) proteins are negative regulators of cytokine responses. Although recent reports have shown regulatory roles for SOCS proteins in innate and adaptive immunity, their roles in natural killer (NK) cell development are largely unknown. Here, we show that SOCS2 is involved in NK cell development. SOCS2−/− mice showed a high frequency of NK cells in the bone marrow and spleen. Knockdown of SOCS2 was associated with enhanced differentiation of NK cells in vitro, and the transplantation of hematopoietic stem cells (HSCs) into congenic mice resulted in enhanced differentiation in SOCS2−/− HSCs. We found that SOCS2 could inhibit Janus kinase 2 (JAK2) activity and JAK2-STAT5 signaling pathways via direct interaction with JAK2. Furthermore, SOCS2−/− mice showed a reduction in lung metastases and an increase in survival following melanoma challenge. Overall, our findings suggest that SOCS2 negatively regulates the development of NK cells by inhibiting JAK2 activity via direct interaction. PMID:28383049

  6. Differential pain modulation properties in central neuropathic pain after spinal cord injury.

    PubMed

    Gruener, Hila; Zeilig, Gabi; Laufer, Yocheved; Blumen, Nava; Defrin, Ruth

    2016-07-01

    It seems that central neuropathic pain (CNP) is associated with altered abilities to modulate pain; whereas dysfunction in descending pain inhibition is associated with the extent of chronic pain distribution, enhanced pain excitation is associated with the intensity of chronic pain. We investigated the hypothesis that CNP is associated with decreased descending pain inhibition along with increased neuronal excitability and that both traits are associated with spinothalamic tract (STT) damage. Chronic spinal cord injury subjects with CNP (n = 27) and without CNP (n = 23) and healthy controls (n = 20) underwent the measurement of pain adaptation, conditioned pain modulation (CPM), tonic suprathreshold pain (TSP), and spatial summation of pain above injury level. Central neuropathic pain subjects also underwent at and below-lesion STT evaluation and completed the questionnaires. Central neuropathic pain subjects showed decreased CPM and increased enhancement of TSP compared with controls. Among CNP subjects, the dysfunction of CPM and pain adaptation correlated positively with the number of painful body regions. The magnitude of TSP and spatial summation of pain correlated positively with CNP intensity. STT scores correlated with CNP intensity and with TSP, so that the more affected the STT below injury level, the greater the CNP and TSP magnitude. It seems that CNP is associated with altered abilities to modulate pain, whereas dysfunction in descending pain inhibition is associated with the extent of chronic pain distribution and enhanced pain excitation is associated with the intensity of chronic pain. Thus, top-down processes may determine the spread of CNP, whereas bottom-up processes may determine CNP intensity. It also seems that the mechanisms of CNP may involve STT-induced hyperexcitability. Future, longitudinal studies may investigate the timeline of this scenario.

  7. Different Current Intensities of Anodal Transcranial Direct Current Stimulation Do Not Differentially Modulate Motor Cortex Plasticity

    PubMed Central

    Kidgell, Dawson J.; Daly, Robin M.; Young, Kayleigh; Lum, Jarrod; Tooley, Gregory; Jaberzadeh, Shapour; Zoghi, Maryam; Pearce, Alan J.

    2013-01-01

    Transcranial direct current stimulation (tDCS) is a noninvasive technique that modulates the excitability of neurons within the motor cortex (M1). Although the aftereffects of anodal tDCS on modulating cortical excitability have been described, there is limited data describing the outcomes of different tDCS intensities on intracortical circuits. To further elucidate the mechanisms underlying the aftereffects of M1 excitability following anodal tDCS, we used transcranial magnetic stimulation (TMS) to examine the effect of different intensities on cortical excitability and short-interval intracortical inhibition (SICI). Using a randomized, counterbalanced, crossover design, with a one-week wash-out period, 14 participants (6 females and 8 males, 22–45 years) were exposed to 10 minutes of anodal tDCS at 0.8, 1.0, and 1.2 mA. TMS was used to measure M1 excitability and SICI of the contralateral wrist extensor muscle at baseline, immediately after and 15 and 30 minutes following cessation of anodal tDCS. Cortical excitability increased, whilst SICI was reduced at all time points following anodal tDCS. Interestingly, there were no differences between the three intensities of anodal tDCS on modulating cortical excitability or SICI. These results suggest that the aftereffect of anodal tDCS on facilitating cortical excitability is due to the modulation of synaptic mechanisms associated with long-term potentiation and is not influenced by different tDCS intensities. PMID:23577272

  8. Different current intensities of anodal transcranial direct current stimulation do not differentially modulate motor cortex plasticity.

    PubMed

    Kidgell, Dawson J; Daly, Robin M; Young, Kayleigh; Lum, Jarrod; Tooley, Gregory; Jaberzadeh, Shapour; Zoghi, Maryam; Pearce, Alan J

    2013-01-01

    Transcranial direct current stimulation (tDCS) is a noninvasive technique that modulates the excitability of neurons within the motor cortex (M1). Although the aftereffects of anodal tDCS on modulating cortical excitability have been described, there is limited data describing the outcomes of different tDCS intensities on intracortical circuits. To further elucidate the mechanisms underlying the aftereffects of M1 excitability following anodal tDCS, we used transcranial magnetic stimulation (TMS) to examine the effect of different intensities on cortical excitability and short-interval intracortical inhibition (SICI). Using a randomized, counterbalanced, crossover design, with a one-week wash-out period, 14 participants (6 females and 8 males, 22-45 years) were exposed to 10 minutes of anodal tDCS at 0.8, 1.0, and 1.2 mA. TMS was used to measure M1 excitability and SICI of the contralateral wrist extensor muscle at baseline, immediately after and 15 and 30 minutes following cessation of anodal tDCS. Cortical excitability increased, whilst SICI was reduced at all time points following anodal tDCS. Interestingly, there were no differences between the three intensities of anodal tDCS on modulating cortical excitability or SICI. These results suggest that the aftereffect of anodal tDCS on facilitating cortical excitability is due to the modulation of synaptic mechanisms associated with long-term potentiation and is not influenced by different tDCS intensities.

  9. Signals from the surface modulate differentiation of human pluripotent stem cells through glycosaminoglycans and integrins.

    PubMed

    Wrighton, Paul J; Klim, Joseph R; Hernandez, Brandon A; Koonce, Chad H; Kamp, Timothy J; Kiessling, Laura L

    2014-12-23

    The fate decisions of human pluripotent stem (hPS) cells are governed by soluble and insoluble signals from the microenvironment. Many hPS cell differentiation protocols use Matrigel, a complex and undefined substrate that engages multiple adhesion and signaling receptors. Using defined surfaces programmed to engage specific cell-surface ligands (i.e., glycosaminoglycans and integrins), the contribution of specific matrix signals can be dissected. For ectoderm and motor neuron differentiation, peptide-modified surfaces that can engage both glycosaminoglycans and integrins are effective. In contrast, surfaces that interact selectively with glycosaminoglycans are superior to Matrigel in promoting hPS cell differentiation to definitive endoderm and mesoderm. The modular surfaces were used to elucidate the signaling pathways underlying these differences. Matrigel promotes integrin signaling, which in turn inhibits mesendoderm differentiation. The data indicate that integrin-activating surfaces stimulate Akt signaling via integrin-linked kinase (ILK), which is antagonistic to endoderm differentiation. The ability to attribute cellular responses to specific interactions between the cell and the substrate offers new opportunities for revealing and controlling the pathways governing cell fate.

  10. Siderophore Biosynthesis Governs the Virulence of Uropathogenic Escherichia coli by Coordinately Modulating the Differential Metabolism.

    PubMed

    Su, Qiao; Guan, Tianbing; He, Yan; Lv, Haitao

    2016-04-01

    Urinary tract infections impose substantial health burdens on women worldwide. Urinary tract infections often incur a high risk of recurrence and antibiotic resistance, and uropathogenic E. coli accounts for approximately 80% of clinically acquired cases. The diagnosis of, treatment of, and drug development for urinary tract infections remain substantial challenges due to the complex pathogenesis of this condition. The clinically isolated UPEC 83972 strain was found to produce four siderophores: yersiniabactin, aerobactin, salmochelin, and enterobactin. The biosyntheses of some of these siderophores implies that the virulence of UPEC is mediated via the targeting of primary metabolism. However, the differential modulatory roles of siderophore biosyntheses on the differential metabolomes of UPEC and non-UPEC strains remain incompletely understood. In the present study, we sought to investigate how the differential metabolomes can be used to distinguish UPEC from non-UPEC strains and to determine the associated regulatory roles of siderophore biosynthesis. Our results are the first to demonstrate that the identified differential metabolomes strongly differentiated UPEC from non-UPEC strains. Furthermore, we performed metabolome assays of mutants with different patterns of siderophore deletions; the data revealed that the mutations of all four siderophores exerted a stronger modulatory role on the differential metabolomes of the UPEC and non-UPEC strains relative to the mutation of any single siderophore and that this modulatory role primarily involved amino acid metabolism, oxidative phosphorylation in the carbon fixation pathway, and purine and pyrimidine metabolism. Surprisingly, the modulatory roles were strongly dependent on the type and number of mutated siderophores. Taken together, these results demonstrated that siderophore biosynthesis coordinately modulated the differential metabolomes and thus may indicate novel targets for virulence-based diagnosis

  11. Cytotype differences modulate eco-geographical differentiation in the widespread plant Centaurea stoebe.

    PubMed

    Hahn, Min A; Müller-Schärer, Heinz

    2013-05-01

    The evolution of optimal life history strategies is central for the fitness of organisms in a given environment. Besides divergent selection, other factors may determine regional patterns of differentiation and contribute to life history evolution. In a common-garden environment over three years, we examined life history differentiation across different eco-geographical regions and effects of a specialist root-insect herbivore in the widespread European plant Centaurea stoebe, spotted knapweed. This plant occurs as two cytotypes with contrasting life cycles: monocarpic diploids and polycarpic tetraploids. In addition, the tetraploid cytotype has more recently become invasive in North America. We found significant regional differentiation in traits related to the timing of reproduction and reproductive allocation, but contrasting patterns in diploids and tetraploids. In diploids the degree of regional differentiation was higher compared to native tetraploids, and in the latter compared to invasive tetraploids. Furthermore, a pronounced shift in environmental conditions between the native and introduced range could have contributed to the differentiation between native and invasive tetraploids. The study also revealed the potential of the root-mining insect herbivore Agapeta zoegana, used as a biological control organism, to increase plant performance (presumably through overcompensatory growth), especially in the polycarpic tetraploids, and more so in the introduced populations. These findings suggest that patterns of regional differentiation in C. stoebe may be partly determined by divergent selection, but also strongly modulated by life cycle differences among geo-cytotypes. Furthermore, our study highlights the importance in applying a comprehensive and long-term approach when studying regional differentiation in plants.

  12. Modulation of human neural stem cell differentiation in Alzheimer (APP23) transgenic mice by phenserine.

    PubMed

    Marutle, Amelia; Ohmitsu, Masao; Nilbratt, Mats; Greig, Nigel H; Nordberg, Agneta; Sugaya, Kiminobu

    2007-07-24

    In a previous study, we found that human neural stem cells (HNSCs) exposed to high concentrations of secreted amyloid-precursor protein (sAPP) in vitro differentiated into mainly astrocytes, suggesting that pathological alterations in APP processing during neurodegenerative conditions such as Alzheimer's disease (AD) may prevent neuronal differentiation of HNSCs. Thus, successful neuroplacement therapy for AD may require regulating APP expression to favorable levels to enhance neuronal differentiation of HNSCs. Phenserine, a recently developed cholinesterase inhibitor (ChEI), has been reported to reduce APP levels in vitro and in vivo. In this study, we found reductions of APP and glial fibrillary acidic protein (GFAP) levels in the hippocampus of APP23 mice after 14 days treatment with (+)-phenserine (25 mg/kg) lacking ChEI activity. No significant change in APP gene expression was detected, suggesting that (+)-phenserine decreases APP levels and reactive astrocytes by posttranscription regulation. HNSCs transplanted into (+)-phenserine-treated APP23 mice followed by an additional 7 days of treatment with (+)-phenserine migrated and differentiated into neurons in the hippocampus and cortex after 6 weeks. Moreover, (+)-phenserine significantly increased neuronal differentiation of implanted HNSCs in hippocampal and cortical regions of APP23 mice and in the CA1 region of control mice. These results indicate that (+)-phenserine reduces APP protein in vivo and increases neuronal differentiation of HNSCs. Combination use of HNSC transplantation and treatment with drugs such as (+)-phenserine that modulate APP levels in the brain may be a useful tool for understanding mechanisms regulating stem cell migration and differentiation during neurodegenerative conditions in AD.

  13. Gonadal steroids differentially modulate the actions of orphanin FQ/nociceptin at a physiologically relevant circuit controlling female sexual receptivity

    PubMed Central

    Borgquist, Amanda; Rivas, Virginia Mela; Kachani, Malika; Sinchak, Kevin; Wagner, Edward J.

    2014-01-01

    Orphanin FQ/nociceptin (OFQ/N) inhibits the activity of proopiomelanocortin (POMC) neurones located in the hypothalamic arcuate nucleus (ARH) that regulate female sexual behaviour and energy balance. We tested the hypothesis that gonadal steroids differentially modulate the ability of OFQ/N to inhibit these cells via presynaptic inhibition of transmitter release and postsynaptic activation of G protein-gated, inwardly-rectifying K+ (GIRK)-1 channels. Whole-cell patch clamp recordings were performed in hypothalamic slices prepared from ovariectomised rats. OFQ/N (1 μM) decreased the frequency of miniature excitatory postsynaptic currents (mEPSCs) and inhibitory postsynaptic currents (mIPSCs), and also caused a robust outward current in the presence of tetrodotoxin, in ARH neurones from vehicle- treated animals. A priming dose of oestradiol benzoate (EB; 2 μg) increased basal mEPSC frequency, markedly diminished both the OFQ/N-induced decrease in mEPSC frequency and the activation of GIRK-1 currents, and potentiated the OFQ/N-induced decrease in mIPSC frequency. Steroid treatment regimens that facilitate sexual receptivity reinstate the basal mEPSC frequency, the OFQ/N-induced decrease in mEPSC frequency and the activation of GIRK-1 currents to levels observed in vehicle-treated controls, and largely abolish the ability of OFQ/N to decrease mIPSC frequency. These effects were observed in an appreciable population of identified POMC neurones, nearly one-half of which projected to the medial preoptic nucleus. Taken together, these data reveal that gonadal steroids influence the pleiotropic actions of OFQ/N on ARH neurones, including POMC neurones, in a disparate manner. These temporal changes in OFQ/N responsiveness further implicate this neuropeptide system as a critical mediator of the gonadal steroid regulation of reproductive behaviour. PMID:24617903

  14. Crebinostat: a novel cognitive enhancer that inhibits histone deacetylase activity and modulates chromatin-mediated neuroplasticity.

    PubMed

    Fass, Daniel M; Reis, Surya A; Ghosh, Balaram; Hennig, Krista M; Joseph, Nadine F; Zhao, Wen-Ning; Nieland, Thomas J F; Guan, Ji-Song; Kuhnle, Chelsea E Groves; Tang, Weiping; Barker, Douglas D; Mazitschek, Ralph; Schreiber, Stuart L; Tsai, Li-Huei; Haggarty, Stephen J

    2013-01-01

    Long-term memory formation is known to be critically dependent upon de novo gene expression in the brain. As a consequence, pharmacological enhancement of the transcriptional processes mediating long-term memory formation provides a potential therapeutic strategy for cognitive disorders involving aberrant neuroplasticity. Here we focus on the identification and characterization of small molecule inhibitors of histone deacetylases (HDACs) as enhancers of CREB (cAMP response element-binding protein)-regulated transcription and modulators of chromatin-mediated neuroplasticity. Using a CREB reporter gene cell line, we screened a library of small molecules structurally related to known HDAC inhibitors leading to the identification of a probe we termed crebinostat that produced robust activation of CREB-mediated transcription. Further characterization of crebinostat revealed its potent inhibition of the deacetylase activity of recombinant class I HDACs 1, 2, 3, and class IIb HDAC6, with weaker inhibition of the class I HDAC8 and no significant inhibition of the class IIa HDACs 4, 5, 7, and 9. In cultured mouse primary neurons, crebinostat potently induced acetylation of both histone H3 and histone H4 as well as enhanced the expression of the CREB target gene Egr1 (early growth response 1). Using a hippocampus-dependent, contextual fear conditioning paradigm, mice systemically administered crebinostat for a ten day time period exhibited enhanced memory. To gain insight into the molecular mechanisms of memory enhancement by HDAC inhibitors, whole genome transcriptome profiling of cultured mouse primary neurons treated with crebinostat, combined with bioinformatic analyses of CREB-target genes, was performed revealing a highly connected protein-protein interaction network reflecting modules of genes important to synaptic structure and plasticity. Consistent with these findings, crebinostat treatment increased the density of synapsin-1 punctae along dendrites in cultured

  15. ReishiMax, mushroom based dietary supplement, inhibits adipocyte differentiation, stimulates glucose uptake and activates AMPK

    PubMed Central

    2011-01-01

    Background Obesity is a health hazard which is closely associated with various complications including insulin resistance, hypertension, dyslipidemia, atherosclerosis, type 2 diabetes and cancer. In spite of numerous preclinical and clinical interventions, the prevalence of obesity and its related disorders are on the rise demanding an urgent need for exploring novel therapeutic agents that can regulate adipogenesis. In the present study, we evaluated whether a dietary supplement ReishiMax (RM), containing triterpenes and polysaccharides extracted from medicinal mushroom Ganoderma lucidum, affects adipocyte differentiation and glucose uptake in 3T3-L1 cells. Methods 3T3-L1 pre-adipocytes were differentiated into adipocytes and treated with RM (0-300 μg/ml). Adipocyte differentiation/lipid uptake was evaluated by oil red O staining and triglyceride and glycerol concentrations were determined. Gene expression was evaluated by semi-quantitative RT-PCR and Western blot analysis. Glucose uptake was determined with [3H]-glucose. Results RM inhibited adipocyte differentiation through the suppresion of expression of adipogenic transcription factors peroxisome proliferator-activated receptor-γ (PPAR-γ), sterol regulatory element binding element protein-1c (SREBP-1c) and CCAAT/enhancer binding protein-α (C/EBP-α). RM also suppressed expression of enzymes and proteins responsible for lipid synthesis, transport and storage: fatty acid synthase (FAS), acyl-CoA synthetase-1 (ACS1), fatty acid binding protein-4 (FABP4), fatty acid transport protein-1 (FATP1) and perilipin. RM induced AMP-activated protein kinase (AMPK) and increased glucose uptake by adipocytes. Conclusion Our study suggests that RM can control adipocyte differentiation and glucose uptake. The health benefits of ReishiMax warrant further clinical studies. PMID:21929808

  16. Amiloride inhibits murine erythroleukemia cell differentiation: evidence for a Ca2+ requirement for commitment.

    PubMed Central

    Levenson, R; Housman, D; Cantley, L

    1980-01-01

    The effect of amiloride (an inhibitor of passive Na+ transport in many tissues) on the differentiation of murine erythroleukemia cells was investigated. Amiloride completely blocked the dimethyl sulfoxide (Me2SO)-induced erythroid differentiation of cells at a concentration (10 microgram/ml) that did not affect cell proliferation. Amiloride also prevented the decrease in cell volume normally observed afte a 20-hr exposure to Me2SO. The ratio of total cell Na+ to total cell water was essentially the same for control cells, Me2SO-treated cells, and cells treated with Me2SO plus amiloride. However, cells treated for 24 hr with Me2SO had a rate of Ca2+ uptake that was twice that of untreated cells and a similarly higher Ca2+ content. Addition of amiloride plus Me2SO prevented both the increase in Ca2+ uptake rate and the increase in Ca2+ content. Cells grown in the presence of Me2SO plus amiloride initiated differentiation immediately after removal of amiloride or addition of the Ca2+ ionophore A23187 (1 microgram/ml). Addition of sufficient ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid to reduce free extracellular Ca2+ to submicromolar levels prevented Me2SO-induced differentiation while only slightly affecting cell proliferation. These results suggest that an increase in in the Ca2+ level is an essential step in Me2SO induction, that amiloride either directly or indirectly inhibits this process, and that Me2SO has an early effect on cells that is necessary for differentiation and is not mimicked by A23187. PMID:6934526

  17. Advanced Sine Wave Modulation of Continuous Wave Laser System for Atmospheric CO2 Differential Absorption Measurements

    NASA Technical Reports Server (NTRS)

    Campbell, Joel F.; Lin, Bing; Nehrir, Amin R.

    2014-01-01

    NASA Langley Research Center in collaboration with ITT Exelis have been experimenting with Continuous Wave (CW) laser absorption spectrometer (LAS) as a means of performing atmospheric CO2 column measurements from space to support the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission.Because range resolving Intensity Modulated (IM) CW lidar techniques presented here rely on matched filter correlations, autocorrelation properties without side lobes or other artifacts are highly desirable since the autocorrelation function is critical for the measurements of lidar return powers, laser path lengths, and CO2 column amounts. In this paper modulation techniques are investigated that improve autocorrelation properties. The modulation techniques investigated in this paper include sine waves modulated by maximum length (ML) sequences in various hardware configurations. A CW lidar system using sine waves modulated by ML pseudo random noise codes is described, which uses a time shifting approach to separate channels and make multiple, simultaneous online/offline differential absorption measurements. Unlike the pure ML sequence, this technique is useful in hardware that is band pass filtered as the IM sine wave carrier shifts the main power band. Both amplitude and Phase Shift Keying (PSK) modulated IM carriers are investigated that exibit perfect autocorrelation properties down to one cycle per code bit. In addition, a method is presented to bandwidth limit the ML sequence based on a Gaussian filter implemented in terms of Jacobi theta functions that does not seriously degrade the resolution or introduce side lobes as a means of reducing aliasing and IM carrier bandwidth.

  18. Effect of RGD-functionalization and stiffness modulation of polyelectrolyte multilayer films on muscle cell differentiation

    PubMed Central

    Gribova, Varvara; Gauthier-Rouvière, Cécile; Albigès-Rizo, Corinne; Auzely-Velty, Rachel; Picart, Catherine

    2014-01-01

    Skeletal muscle tissue engineering holds promise for the replacement of muscle due to an injury and for the treatment of muscle diseases. Although RGD substrates have been widely explored in tissue engineering, there is no study aimed at investigating the combined effects of RGD nanoscale presentation and matrix stiffness on myogenesis. In the present work, we use polyelectrolyte multilayer films made of poly(L-lysine) (PLL) and poly(L-glutamic) acid (PGA) as substrates of tunable stiffness that can be functionalized by a RGD adhesive peptide to investigate important events in myogenesis, including adhesion, migration, proliferation and differentiation. C2C12 myoblasts were used as cellular models. RGD presentation on soft films and increased film stiffness could both induce cell adhesion, but integrins involved in adhesion were different in case of soft and stiff films. Moreover, soft films with RGD peptide appeared to be the most appropriate substrate for myogenic differentiation while the stiff PLL/PGA films significantly induced cell migration, proliferation and inhibited myogenic differentiation. The ROCK kinase was found to be involved in myoblast response to the different films. Indeed, its inhibition was sufficient to rescue the differentiation on stiff films, but no significant changes were observed on stiff films with the RGD peptide. These results suggest that different signaling pathways may be activated depending on mechanical and biochemical properties of the multilayer films. This study emphasizes the superior advantage of the soft PLL/PGA films presenting the RGD peptide in terms of myogenic differentiation. This soft RGD-presenting film may be further used as coating of various polymeric scaffolds for muscle tissue engineering. PMID:23261924

  19. Myofibroblast differentiation and its functional properties are inhibited by nicotine and e-cigarette via mitochondrial OXPHOS complex III

    PubMed Central

    Lei, Wei; Lerner, Chad; Sundar, Isaac K.; Rahman, Irfan

    2017-01-01

    Nicotine is the major stimulant in tobacco products including e-cigarettes. Fibroblast to myofibroblast differentiation is a key process during wound healing and is dysregulated in lung diseases. The role of nicotine and e-cigarette derived nicotine on cellular functions including profibrotic response and other functional aspects is not known. We hypothesized that nicotine and e-cigarettes affect myofibroblast differentiation, gel contraction, and wound healing via mitochondria stress through nicotinic receptor-dependent mechanisms. To test the hypothesis, we exposed human lung fibroblasts with various doses of nicotine and e-cigarette condensate and determined myofibroblast differentiation, mitochondrial oxidative phosphorylation (OXPHOS), wound healing, and gel contraction at different time points. We found that both nicotine and e-cigarette inhibit myofibroblast differentiation as shown by smooth muscle actin and collagen type I, alpha 1 abundance. Nicotine and e-cigarette inhibited OXPHOS complex III accompanied by increased MitoROS, and this effect was augmented by complex III inhibitor antimycin A. These mitochondrial associated effects by nicotine resulted in inhibition of myofibroblast differentiation. These effects were associated with inhibition of wound healing and gel contraction suggesting that nicotine is responsible for dysregulated repair during injurious responses. Thus, our data suggest that nicotine causes dysregulated repair by inhibition of myofibroblast differentiation via OXPHOS pathway. PMID:28256533

  20. Differential neurophysiological correlates of bottom-up and top-down modulations of pain.

    PubMed

    Tiemann, Laura; May, Elisabeth S; Postorino, Martina; Schulz, Enrico; Nickel, Moritz M; Bingel, Ulrike; Ploner, Markus

    2015-02-01

    The perception of pain is highly variable. It depends on bottom-up-mediated factors like stimulus intensity and top-down-mediated factors like expectations. In the brain, pain is associated with a complex pattern of neuronal responses including evoked potentials and induced responses at alpha and gamma frequencies. Although they all covary with stimulus intensity and pain perception, responses at gamma frequencies can be particularly closely related to the perception of pain. It is, however, unclear whether this association holds true across all types of pain modulation. Here, we used electroencephalography to directly compare bottom-up- and top-down-mediated modulations of pain, which were implemented by changes in stimulus intensity and placebo analgesia, respectively. The results show that stimulus intensity modulated pain-evoked potentials and pain-induced alpha and gamma responses. In contrast, placebo analgesia was associated with changes of evoked potentials, but not of alpha and gamma responses. These findings reveal that pain-related neuronal responses are differentially sensitive to bottom-up and top-down modulations of pain, indicating that they provide complementary information about pain perception. The results further show that pain-induced gamma oscillations do not invariably encode pain perception but may rather represent a marker of sensory processing whose influence on pain perception varies with behavioral context.

  1. Cannabinoid receptor activation differentially modulates ion channels in photoreceptors of the tiger salamander.

    PubMed

    Straiker, Alex; Sullivan, Jane M

    2003-05-01

    Cannabinoid CB1 receptors have been detected in retinas of numerous species, with prominent labeling in photoreceptor terminals of the chick and monkey. CB1 labeling is well-conserved across species, suggesting that CB1 receptors might also be present in photoreceptors of the tiger salamander. Synaptic transmission in vertebrate photoreceptors is mediated by L-type calcium currents-currents that are modulated by CB1 receptors in bipolar cells of the tiger salamander. Presence of CB1 receptors in photoreceptor terminals would therefore be consistent with presynaptic modulation of synaptic transmission, a role seen for cannabinoids in other parts of the brain. Here we report immunohistochemical and electrophysiological evidence for the presence of functional CB1 receptors in rod and cone photoreceptors of the tiger salamander. The cannabinoid receptor agonist WIN 55212-2 enhances calcium currents of rod photoreceptors by 39% but decreases calcium currents of large single cones by 50%. In addition, WIN 55212-2 suppresses potassium currents of rods and large single cones by 44 and 48%, respectively. Thus functional CB1 receptors, present in the terminals of rod and cone photoreceptors, differentially modulate calcium and potassium currents in rods and large single cones. CB1 receptors are therefore well positioned to modulate neurotransmitter release at the first synapse of the visual system.

  2. Differential Purkinje cell simple spike activity and pausing behavior related to cerebellar modules

    PubMed Central

    Zhou, Haibo; Voges, Kai; Lin, Zhanmin; Ju, Chiheng

    2015-01-01

    The massive computational capacity of the cerebellar cortex is conveyed by Purkinje cells onto cerebellar and vestibular nuclei neurons through their GABAergic, inhibitory output. This implies that pauses in Purkinje cell simple spike activity are potentially instrumental in cerebellar information processing, but their occurrence and extent are still heavily debated. The cerebellar cortex, although often treated as such, is not homogeneous. Cerebellar modules with distinct anatomical connectivity and gene expression have been described, and Purkinje cells in these modules also differ in firing rate of simple and complex spikes. In this study we systematically correlate, in awake mice, the pausing in simple spike activity of Purkinje cells recorded throughout the entire cerebellum, with their location in terms of lobule, transverse zone, and zebrin-identified cerebellar module. A subset of Purkinje cells displayed long (>500-ms) pauses, but we found that their occurrence correlated with tissue damage and lower temperature. In contrast to long pauses, short pauses (<500 ms) and the shape of the interspike interval (ISI) distributions can differ between Purkinje cells of different lobules and cerebellar modules. In fact, the ISI distributions can differ both between and within populations of Purkinje cells with the same zebrin identity, and these differences are at least in part caused by differential synaptic inputs. Our results suggest that long pauses are rare but that there are differences related to shorter intersimple spike intervals between and within specific subsets of Purkinje cells, indicating a potential further segregation in the activity of cerebellar Purkinje cells. PMID:25717166

  3. A staggered differential phase-shift keying modulation format for 100Gbit/s applications.

    PubMed

    Shao, Yufeng; Wen, Shuangchun; Chen, Lin; Li, Ying; Xu, Huiwen

    2008-08-18

    We propose and demonstrate by numerical simulation a new phase modulation format, the staggered differential phase-shift keying (SDPSK), for 100 Gbit/s applications. Non-return-to-zero (NRZ) SDPSK signals was generated by using two phase modulators, and return-to-zero (RZ) SDPSK signals with 50% duty cycle was generated by cascading a dual-arm Mach-Zehnder modulator. The demodulation of 2 bit/symbol can be simply achieved on 1 bit rate through only one Mach-Zehnder delay interferometer and a balanced receiver. By comparing the transmission characteristics of the two staggered phase modulation formats with those of NRZ-DPSK, RZ-DPSK, NRZ-DQPSK, and RZ-DQPSK, respectively, we show that, the SDPSK signal has similar chromatic dispersion and polarization-mode-dispersion tolerance to the DPSK signal with same NRZ or RZ shape, while the SDPSK signal has stronger nonlinear tolerance than the DPSK or DQPSK signal. In addition, the SDPSK signal has the best transmission performance when each signal was transmitted over 106km optical SMF+DCF, and then launched into a third-order Gaussian optical bandpass filter placed with beyond 125GHz bandwidth.

  4. Adrenal-Derived Hormones Differentially Modulate Intestinal Immunity in Experimental Colitis

    PubMed Central

    de Souza, Patrícia Reis; Basso, Paulo José; Nardini, Viviani; Silva, Angelica; Banquieri, Fernanda

    2016-01-01

    The adrenal glands are able to modulate immune responses through neuroimmunoendocrine interactions and cortisol secretion that could suppress exacerbated inflammation such as in inflammatory bowel disease (IBD). Therefore, here we evaluated the role of these glands in experimental colitis induced by 3% dextran sulfate sodium (DSS) in C57BL/6 mice subjected to adrenalectomy, with or without glucocorticoid (GC) replacement. Mice succumbed to colitis without adrenals with a higher clinical score and augmented systemic levels of IL-6 and lower LPS. Furthermore, adrenalectomy negatively modulated systemic regulatory markers. The absence of adrenals resulted in augmented tolerogenic lamina propria dendritic cells but no compensatory local production of corticosterone and decreased mucosal inflammation associated with increased IFN-γ and FasL in the intestine. To clarify the importance of GC in this scenario, GC replacement in adrenalectomized mice restored different markers to the same degree of that observed in DSS group. Finally, this is the first time that adrenal-derived hormones, especially GC, were associated with the differential local modulation of the gut infiltrate, also pointing to a relationship between adrenalectomy and the modulation of systemic regulatory markers. These findings may elucidate some neuroimmunoendocrine mechanisms that dictate colitis outcome. PMID:27403034

  5. Differential Inhibition of Signal Peptide Peptidase Family Members by Established γ-Secretase Inhibitors

    PubMed Central

    Ran, Yong; Ladd, Gabriela Z.; Ceballos-Diaz, Carolina; Jung, Joo In; Greenbaum, Doron; Felsenstein, Kevin M.; Golde, Todd E.

    2015-01-01

    The signal peptide peptidases (SPPs) are biomedically important proteases implicated as therapeutic targets for hepatitis C (human SPP, (hSPP)), plasmodium (Plasmodium SPP (pSPP)), and B-cell immunomodulation and neoplasia (signal peptide peptidase like 2a, (SPPL2a)). To date, no drug-like, selective inhibitors have been reported. We use a recombinant substrate based on the amino-terminus of BRI2 fused to amyloid β 1-25 (Aβ1-25) (FBA) to develop facile, cost-effective SPP/SPPL protease assays. Co-transfection of expression plasmids expressing the FBA substrate with SPP/SPPLs were conducted to evaluate cleavage, which was monitored by ELISA, Western Blot and immunoprecipitation/MALDI-TOF Mass spectrometry (IP/MS). No cleavage is detected in the absence of SPP/SPPL overexpression. Multiple γ-secretase inhibitors (GSIs) and (Z-LL)2 ketone differentially inhibited SPP/SPPL activity; for example, IC50 of LY-411,575 varied from 51±79 nM (on SPPL2a) to 5499±122 nM (on SPPL2b), while Compound E showed inhibition only on hSPP with IC50 of 1465±93 nM. Data generated were predictive of effects observed for endogenous SPPL2a cleavage of CD74 in a murine B-Cell line. Thus, it is possible to differentially inhibit SPP family members. These SPP/SPPL cleavage assays will expedite the search for selective inhibitors. The data also reinforce similarities between SPP family member cleavage and cleavage catalyzed by γ-secretase. PMID:26046535

  6. Trehalose differentially inhibits aggregation and neurotoxicity of beta-amyloid 40 and 42.

    PubMed

    Liu, Ruitian; Barkhordarian, Hedieh; Emadi, Sharareh; Park, Chan Beum; Sierks, Michael R

    2005-10-01

    A key event in Alzheimer's disease (AD) pathogenesis is the conversion of the peptide beta-amyloid (Abeta) from its soluble monomeric form into various aggregated morphologies in the brain. Preventing aggregation of Abeta is being actively pursued as a primary therapeutic strategy for treating AD. Trehalose, a simple disaccharide, has been shown to be effective in preventing the deactivation of numerous proteins and in protecting cells against stress. Here, we show that trehalose is also effective in inhibiting aggregation of Abeta and reducing its cytotoxicity, although it shows differential effects toward Abeta40 and Abeta42. When co-incubated with Abeta40, trehalose inhibits formation of both fibrillar and oligomeric morphologies as determined by fluorescence staining and atomic force microscopy (AFM). However, when co-incubated with Abeta42, trehalose inhibits formation only of the fibrillar morphology, with significant oligomeric formation still present. When aggregated mixtures were incubated with SH-SY5Y cells, trehalose was shown to reduce the toxicity of Abeta40 mixtures, but not Abeta42. These results provide additional evidence that aggregation of Abeta into soluble oligomeric forms is a pathological step in AD and that Abeta42 in particular is more susceptible to forming these toxic oligomers than Abeta40. These results also suggest that the use of trehalose, a highly soluble, low-priced sugar, as part of a potential therapeutic cocktail to control Abeta peptide aggregation and toxicity warrants further study.

  7. Differential effects of rapamycin treatment on tonic and phasic GABAergic inhibition in dentate granule cells after focal brain injury in mice.

    PubMed

    Butler, Corwin R; Boychuk, Jeffery A; Smith, Bret N

    2016-06-01

    The cascade of events leading to post-traumatic epilepsy (PTE) after traumatic brain injury (TBI) remains unclear. Altered inhibition in the hippocampal formation and dentate gyrus is a hallmark of several neurological disorders, including TBI and PTE. Inhibitory synaptic signaling in the hippocampus is predominately driven by γ-aminobutyric acid (GABA) neurotransmission, and is prominently mediated by postsynaptic type A GABA receptors (GABAAR's). Subsets of these receptors involved in tonic inhibition of neuronal membranes serve a fundamental role in maintenance of inhibitory state, and GABAAR-mediated tonic inhibition is altered functionally in animal models of both TBI and epilepsy. In this study, we assessed the effect of mTOR inhibition on hippocampal hilar inhibitory interneuron loss and synaptic and tonic GABAergic inhibition of dentate gyrus granule cells (DGCs) after controlled cortical impact (CCI) to determine if mTOR activation after TBI modulates GABAAR function. Hilar inhibitory interneuron density was significantly reduced 72h after CCI injury in the dorsal two-thirds of the hemisphere ipsilateral to injury compared with the contralateral hemisphere and sham controls. Rapamycin treatment did not alter this reduction in cell density. Synaptic and tonic current measurements made in DGCs at both 1-2 and 8-13weeks post-injury indicated reduced synaptic inhibition and THIP-induced tonic current density in DGCs ipsilateral to CCI injury at both time points post-injury, with no change in resting tonic GABAAR-mediated currents. Rapamycin treatment did not alter the reduced synaptic inhibition observed in ipsilateral DGCs 1-2weeks post-CCI injury, but further reduced synaptic inhibition of ipsilateral DGCs at 8-13weeks post-injury. The reduction in THIP-induced tonic current after injury, however, was prevented by rapamycin treatment at both time points. Rapamycin treatment thus differentially modifies CCI-induced changes in synaptic and tonic GABAAR

  8. Induction of Dlk1 by PTTG1 inhibits adipocyte differentiation and correlates with malignant transformation.

    PubMed

    Espina, Agueda G; Méndez-Vidal, Cristina; Moreno-Mateos, Miguel A; Sáez, Carmen; Romero-Franco, Ana; Japón, Miguel A; Pintor-Toro, José A

    2009-07-01

    Pituitary tumor-transforming gene-1 (PTTG1) is an oncogene highly expressed in a variety of endocrine, as well as nonendocrine-related cancers. Several tumorigenic mechanisms for PTTG1 have been proposed, one of the best characterized being its capacity to act as a transcriptional activator. To identify novel downstream target genes, we have established cell lines with inducible expression of PTTG1 and a differential display approach to analyze gene expression changes after PTTG1 induction. We identified dlk1 (also known as pref-1) as one of the most abundantly expressed PTTG1 targets. Dlk1 is known to participate in several differentiation processes, including adipogenesis, adrenal gland development, and wound healing. Dlk1 is also highly expressed in neuroendocrine tumors. Here, we show that PTTG1 overexpression inhibits adipogenesis in 3T3-L1 cells and that this effect is accomplished by promoting the stability and accumulation of Dlk1 mRNA, supporting a role for PTTG1 in posttranscriptional regulation. Moreover, both pttg1 and dlk1 genes show concomitant expression in fetal liver and placenta, as well as in pituitary adenomas, breast adenocarcinomas, and neuroblastomas, suggesting that PTTG1 and DLK1 are involved in cell differentiation and transformation.

  9. Mutant IDH inhibits HNF-4α to block hepatocyte differentiation and promote biliary cancer.

    PubMed

    Saha, Supriya K; Parachoniak, Christine A; Ghanta, Krishna S; Fitamant, Julien; Ross, Kenneth N; Najem, Mortada S; Gurumurthy, Sushma; Akbay, Esra A; Sia, Daniela; Cornella, Helena; Miltiadous, Oriana; Walesky, Chad; Deshpande, Vikram; Zhu, Andrew X; Hezel, Aram F; Yen, Katharine E; Straley, Kimberly S; Travins, Jeremy; Popovici-Muller, Janeta; Gliser, Camelia; Ferrone, Cristina R; Apte, Udayan; Llovet, Josep M; Wong, Kwok-Kin; Ramaswamy, Sridhar; Bardeesy, Nabeel

    2014-09-04

    Mutations in isocitrate dehydrogenase 1 (IDH1) and IDH2 are among the most common genetic alterations in intrahepatic cholangiocarcinoma (IHCC), a deadly liver cancer. Mutant IDH proteins in IHCC and other malignancies acquire an abnormal enzymatic activity allowing them to convert α-ketoglutarate (αKG) to 2-hydroxyglutarate (2HG), which inhibits the activity of multiple αKG-dependent dioxygenases, and results in alterations in cell differentiation, survival, and extracellular matrix maturation. However, the molecular pathways by which IDH mutations lead to tumour formation remain unclear. Here we show that mutant IDH blocks liver progenitor cells from undergoing hepatocyte differentiation through the production of 2HG and suppression of HNF-4α, a master regulator of hepatocyte identity and quiescence. Correspondingly, genetically engineered mouse models expressing mutant IDH in the adult liver show an aberrant response to hepatic injury, characterized by HNF-4α silencing, impaired hepatocyte differentiation, and markedly elevated levels of cell proliferation. Moreover, IDH and Kras mutations, genetic alterations that co-exist in a subset of human IHCCs, cooperate to drive the expansion of liver progenitor cells, development of premalignant biliary lesions, and progression to metastatic IHCC. These studies provide a functional link between IDH mutations, hepatic cell fate, and IHCC pathogenesis, and present a novel genetically engineered mouse model of IDH-driven malignancy.

  10. Inhibition of GSK-3β enhances neural differentiation in unrestricted somatic stem cells.

    PubMed

    Dastjerdi, Fatemeh Vahid; Zeynali, Bahman; Tafreshi, Azita Parvaneh; Shahraz, Anahita; Chavoshi, Mahin Sadat; Najafabadi, Irandokht Khaki; Vardanjani, Marzieh Mowlavi; Atashi, Amir; Soleimani, Masoud

    2012-11-01

    GSK-3β is a key molecule in several signalling pathways, including the Wnt/β-catenin signalling pathway. There is increasing evidence suggesting Wnt/β-catenin signalling is involved in the neural differentiation of embryonic, somatic and neural stem cells. However, a large body of evidence indicates that this pathway maintains stem cells in a proliferative state. To address this controversy, we have investigated whether the Wnt/β-catenin pathway is present and involved in the neural differentiation of newly introduced USSCs (unrestricted somatic stem cells). Our results indicate that the components of Wnt/β-catenin signalling are present in undifferentiated USSCs. We also show that the treatment of neurally induced USSCs with BIO (6-bromoindirubin-3'-oxime), a specific GSK-3β inhibitor and Wnt activator, for 5 and 10 days results in increased expression of a general neuronal marker (β-tubulin III). Moreover, the expression of pGSK-3β and stabilized β-catenin increased by BIO in neurally induced USSCs, indicates that the Wnt pathway is activated and functional in these cells. Thus, inhibition of GSK-3β in USSCs enhances their neural differentiation, which suggests a positive role of the Wnt/β-catenin signalling pathway towards neural fate.

  11. Selective inhibition of Ebola entry with selective estrogen receptor modulators by disrupting the endolysosomal calcium

    PubMed Central

    Fan, Hanlu; Du, Xiaohong; Zhang, Jingyuan; Zheng, Han; Lu, Xiaohui; Wu, Qihui; Li, Haifeng; Wang, Han; Shi, Yi; Gao, George; Zhou, Zhuan; Tan, Dun-Xian; Li, Xiangdong

    2017-01-01

    The Ebola crisis occurred in West-Africa highlights the urgency for its clinical treatments. Currently, no Food and Drug Administration (FDA)-approved therapeutics are available. Several FDA-approved drugs, including selective estrogen receptor modulators (SERMs), possess selective anti-Ebola activities. However, the inhibitory mechanisms of these drugs remain elusive. By analyzing the structures of SERMs and their incidental biological activity (cholesterol accumulation), we hypothesized that this incidental biological activity induced by SERMs could be a plausible mechanism as to their inhibitory effects on Ebola infection. Herein, we demonstrated that the same dosages of SERMs which induced cholesterol accumulation also inhibited Ebola infection. SERMs reduced the cellular sphingosine and subsequently caused endolysosomal calcium accumulation, which in turn led to blocking the Ebola entry. Our study clarified the specific anti-Ebola mechanism of SERMs, even the cationic amphiphilic drugs (CADs), this mechanism led to the endolysosomal calcium as a critical target for development of anti-Ebola drugs. PMID:28117364

  12. To fold or not to fold: modulation and consequences of Hsp90 inhibition

    PubMed Central

    Peterson, Laura B; Blagg, Brian SJ

    2009-01-01

    Background The 90-kDa heat-shock proteins (Hsp90) have rapidly evolved into promising therapeutic targets for the treatment of several diseases, including cancer and neurodegenerative diseases. Hsp90 is a molecular chaperone that aids in the conformational maturation of nascent polypeptides, as well as the rematuration of denatured proteins. Discussion Many of the Hsp90-dependent client proteins are associated with cellular growth and survival and, consequently, inhibition of Hsp90 represents a promising approach for the treatment of cancer. Conversely, stimulation of heat-shock protein levels has potential therapeutic applications for the treatment of neurodegenerative diseases that result from misfolded and aggregated proteins. Conclusion Hsp90 modulation exhibits the potential to treat unrelated disease states, from cancer to neurodegenerative diseases, and, thus, to fold or not to fold, becomes a question of great value. PMID:20161407

  13. Human myeloblastic leukemia cells (HL-60) express a membrane receptor for estrogen that signals and modulates retinoic acid-induced cell differentiation

    SciTech Connect

    Kauss, M. Ariel; Reiterer, Gudrun; Bunaciu, Rodica P.; Yen, Andrew

    2008-10-01

    Estrogen receptors are historically perceived as nuclear ligand activated transcription factors. An estrogen receptor has now been found localized to the plasma membrane of human myeloblastic leukemia cells (HL-60). Its expression occurs throughout the cell cycle, progressively increasing as cells mature from G{sub 1} to S to G{sub 2}/M. To ascertain that the receptor functioned, the effect of ligands, including a non-internalizable estradiol-BSA conjugate and tamoxifen, an antagonist of nuclear estrogen receptor function, were tested. The ligands caused activation of the ERK MAPK pathway. They also modulated the effect of retinoic acid, an inducer of MAPK dependent terminal differentiation along the myeloid lineage in these cells. In particular the ligands inhibited retinoic acid-induced inducible oxidative metabolism, a functional marker of terminal myeloid cell differentiation. To a lesser degree they also diminished retinoic acid-induced earlier markers of cell differentiation, namely CD38 and CD11b. However, they did not regulate retinoic acid-induced G{sub 0} cell cycle arrest. There is thus a membrane localized estrogen receptor in HL-60 myeloblastic leukemia cells that can cause ERK activation and modulates the response of these cells to retinoic acid, indicating crosstalk between the membrane estrogen and retinoic acid evoked pathways relevant to propulsion of cell differentiation.

  14. Human myeloblastic leukemia cells (HL-60) express a membrane receptor for estrogen that signals and modulates retinoic acid-induced cell differentiation.

    PubMed

    Kauss, M Ariel; Reiterer, Gudrun; Bunaciu, Rodica P; Yen, Andrew

    2008-10-01

    Estrogen receptors are historically perceived as nuclear ligand activated transcription factors. An estrogen receptor has now been found localized to the plasma membrane of human myeloblastic leukemia cells (HL-60). Its expression occurs throughout the cell cycle, progressively increasing as cells mature from G(1) to S to G(2)/M. To ascertain that the receptor functioned, the effect of ligands, including a non-internalizable estradiol-BSA conjugate and tamoxifen, an antagonist of nuclear estrogen receptor function, were tested. The ligands caused activation of the ERK MAPK pathway. They also modulated the effect of retinoic acid, an inducer of MAPK dependent terminal differentiation along the myeloid lineage in these cells. In particular the ligands inhibited retinoic acid-induced inducible oxidative metabolism, a functional marker of terminal myeloid cell differentiation. To a lesser degree they also diminished retinoic acid-induced earlier markers of cell differentiation, namely CD38 and CD11b. However, they did not regulate retinoic acid-induced G(0) cell cycle arrest. There is thus a membrane localized estrogen receptor in HL-60 myeloblastic leukemia cells that can cause ERK activation and modulates the response of these cells to retinoic acid, indicating crosstalk between the membrane estrogen and retinoic acid evoked pathways relevant to propulsion of cell differentiation.

  15. Differential modulation of gene expression in the NMDA postsynaptic density of schizophrenic and control smokers.

    PubMed

    Mexal, S; Frank, M; Berger, R; Adams, C E; Ross, R G; Freedman, R; Leonard, S

    2005-10-03

    Nicotine is known to induce the release of multiple neurotransmitters, including glutamate and dopamine, through activation of nicotinic receptors. Gene expression in the N-methyl-d-aspartate postsynaptic density (NMDA-PSD), as well as other functional groups, was compared in postmortem hippocampus of schizophrenic and nonmentally ill smokers and nonsmokers utilizing a microarray and quantitative RT-PCR approach. The expression of 277 genes was significantly changed between all smokers and nonsmokers. Specific gene groups, most notably genes expressed in the NMDA-PSD, were prevalent among these transcripts. Analysis of the interaction between smoking and schizophrenia identified several genes in the NMDA-PSD that were differentially affected by smoking in patients. The present findings suggest that smoking may differentially modulate glutamatergic function in schizophrenic patients and control subjects. The biological mechanisms underlying chronic tobacco use are likely to differ substantially between these two groups.

  16. Compound A, a Dissociated Glucocorticoid Receptor Modulator, Inhibits T-bet (Th1) and Induces GATA-3 (Th2) Activity in Immune Cells

    PubMed Central

    Ferraz-de-Paula, Viviane; Palermo-Neto, Joao; Castro, Carla N.; Druker, Jimena; Holsboer, Florian; Perone, Marcelo J.; Gerlo, Sarah; De Bosscher, Karolien; Haegeman, Guy; Arzt, Eduardo

    2012-01-01

    Background Compound A (CpdA) is a dissociating non-steroidal glucocorticoid receptor (GR) ligand which has anti-inflammatory properties exerted by down-modulating proinflammatory gene expression. By favouring GR monomer formation, CpdA does not enhance glucocorticoid (GC) response element-driven gene expression, resulting in a reduced side effect profile as compared to GCs. Considering the importance of Th1/Th2 balance in the final outcome of immune and inflammatory responses, we analyzed how selective GR modulation differentially regulates the activity of T-bet and GATA-3, master drivers of Th1 and Th2 differentiation, respectively. Results Using Western analysis and reporter gene assays, we show in murine T cells that, similar to GCs, CpdA inhibits T-bet activity via a transrepressive mechanism. Different from GCs, CpdA induces GATA-3 activity by p38 MAPK-induction of GATA-3 phosphorylation and nuclear translocation. CpdA effects are reversed by the GR antagonist RU38486, proving the involvement of GR in these actions. ELISA assays demonstrate that modulation of T-bet and GATA-3 impacts on cytokine production shown by a decrease in IFN-γ and an increase in IL-5 production, respectively. Conclusions Taken together, through their effect favoring Th2 over Th1 responses, particular dissociated GR ligands, for which CpdA represents a paradigm, hold potential for the application in Th1-mediated immune disorders. PMID:22496903

  17. TRPV1 attenuates intracranial arteriole remodeling through inhibiting VSMC phenotypic modulation in hypertension.

    PubMed

    Zhang, Ming-Jie; Liu, Yun; Hu, Zi-Cheng; Zhou, Yi; Pi, Yan; Guo, Lu; Wang, Xu; Chen, Xue; Li, Jing-Cheng; Zhang, Li-Li

    2017-04-01

    The phenotypic modulation of contractile vascular smooth muscle cell (VSMC) is widely accepted as the pivotal process in the arterial remodeling induced by hypertension. This study aimed to investigate the potential role of transient receptor potential vanilloid type 1 (TRPV1) on regulating VSMC plasticity and intracranial arteriole remodeling in hypertension. Spontaneously hypertensive rats (SHR), Wistar-Kyoto (WKY) rats and TRPV1(-/-) mice on a C57BL/6J background were used. By microscopic observation of the histopathological sections of vessels from hypertensive SHR and age-matched normotensive WKY control rats, we found that hypertension induced arterial remodeling. Decreased α-smooth muscle actin (α-SMA) and SM22α while increased osteopontin (OPN) were observed in aorta and VSMCs derived from SHR compared with those in WKY, and VSMCs derived from SHR upregulated inflammatory factors. TRPV1 activation by capsaicin significantly increased expression of α-SMA and SM22α, reduced expression of OPN, retarded proliferative and migratory capacities and inhibited inflammatory status in VSMCs from SHR, which was counteracted by TRPV1 antagonist 5'-iodoresiniferatoxin (iRTX) combined with capsaicin. TRPV1 activation by capsaicin ameliorated intracranial arteriole remodeling in SHR and deoxycorticosterone acetate (DOCA)-salt hypertensive mice. However, the attenuation of arteriole remodeling by capsaicin was not observed in TRPV1(-/-) mice. Furthermore, TRPV1 activation significantly decreased the activity of PI3K and phosphorylation level of Akt in SHR-derived VSMCs. Taken together, we provide evidence that TRPV1 activation by capsaicin attenuates intracranial arteriole remodeling through inhibiting VSMC phenotypic modulation during hypertension, which may be at least partly attributed to the suppression PI3K/Akt signaling pathway. These findings highlight the prospect of TRPV1 in prevention and treatment of hypertension.

  18. Pb2+ via protein kinase C inhibits nicotinic cholinergic modulation of synaptic transmission in the hippocampus.

    PubMed

    Braga, Maria F M; Pereira, Edna F R; Mike, Arpad; Albuquerque, Edson X

    2004-11-01

    The present study was designed to investigate the effects of Pb(2+) on modulation of synaptic transmission by nicotinic receptors (nAChRs) in the rat hippocampus. To this end, inhibitory and excitatory postsynaptic currents (IPSCs and EPSCs, respectively) were recorded by means of the whole-cell mode of the patch-clamp technique from rat hippocampal neurons in culture. Acetylcholine (ACh, 1 mM; 1-s pulses) triggered GABA release via activation of alpha4beta2* and alpha7* nAChRs. It also triggered glutamate release via activation of alpha7* nAChRs. Pb(2+) (0.1 and 1 microM) blocked ACh-triggered transmitter release. Blockade by Pb(2+) of ACh-triggered IPSCs was partially reversible upon washing of the neurons. In contrast, even after 30- to 60-min washing, there was no reversibility of Pb(2+)-induced blockade of ACh-triggered EPSCs. The effects of Pb(2+) on GABA release triggered by activation of alpha7* and alpha4beta2* nACRs were mimicked by the protein kinase C (PKC) activator phorbol-12-myristate-13-acetate (1 microM) and blocked by the indolocarbazole Go 7874 (50 nM) and the bisindolylmaleimide Ro-31-8425 (150 nM), which are selective PKC inhibitors. After washing of fully functional neuronal networks that had been exposed for 5 min to Pb(2+), the irreversible inhibition by Pb(2+) of ACh-triggered glutamate release was partially overridden by a disinhibitory mechanism that is likely to involve alpha4beta2* nAChR activation in interneurons that synapse onto other interneurons synapsing onto pyramidal neurons. Long-lasting inhibition of alpha7* nAChR modulation of synaptic transmission may contribute to the persistent cognitive impairment that results from childhood Pb(2+) intoxication.

  19. Estrogen-related receptor {alpha} modulates the expression of adipogenesis-related genes during adipocyte differentiation

    SciTech Connect

    Ijichi, Nobuhiro; Ikeda, Kazuhiro; Horie-Inoue, Kuniko; Yagi, Ken; Okazaki, Yasushi; Inoue, Satoshi . E-mail: INOUE-GER@h.u-tokyo.ac.jp

    2007-07-06

    Estrogen-related receptor {alpha} (ERR{alpha}) is an orphan nuclear receptor that regulates cellular energy metabolism by modulating gene expression involved in fatty acid oxidation and mitochondrial biogenesis in brown adipose tissue. However, the physiological role of ERR{alpha} in adipogenesis and white adipose tissue development has not been well studied. Here, we show that ERR{alpha} and ERR{alpha}-related transcriptional coactivators, peroxisome proliferator-activated receptor {gamma} (PPAR{gamma}) coactivator-1{alpha} (PGC-1{alpha}) and PGC-1{beta}, can be up-regulated in 3T3-L1 preadipocytes at mRNA levels under the adipogenic differentiation condition including the inducer of cAMP, glucocorticoid, and insulin. Gene knockdown by ERR{alpha}-specific siRNA results in mRNA down-regulation of fatty acid binding protein 4, PPAR{gamma}, and PGC-1{alpha} in 3T3-L1 cells in the adipogenesis medium. ERR{alpha} and PGC-1{beta} mRNA expression can be also up-regulated in another preadipocyte lineage DFAT-D1 cells and a pluripotent mesenchymal cell line C3H10T1/2 under the differentiation condition. Furthermore, stable expression of ERR{alpha} in 3T3-L1 cells up-regulates adipogenic marker genes and promotes triglyceride accumulation during 3T3-L1 differentiation. These results suggest that ERR{alpha} may play a critical role in adipocyte differentiation by modulating the expression of various adipogenesis-related genes.

  20. Kaempferol inhibits vascular smooth muscle cell migration by modulating BMP-mediated miR-21 expression.

    PubMed

    Kim, Kwangho; Kim, Sunghwan; Moh, Sang Hyun; Kang, Hara

    2015-09-01

    Bioflavonoids are known to induce cardioprotective effects by inhibiting vascular smooth muscle cell (VSMC) proliferation and migration. Kaempferol has been shown to inhibit VSMC proliferation. However, little is known about the effect of kaempferol on VSMC migration and the underlying molecular mechanisms. Our studies provide the first evidence that kaempferol inhibits VSMC migration by modulating the BMP4 signaling pathway and microRNA expression levels. Kaempferol activates the BMP signaling pathway, induces miR-21 expression and downregulates DOCK4, 5, and 7, leading to inhibition of cell migration. Moreover, kaempferol antagonizes the PDGF-mediated pro-migratory effect. Therefore, our study uncovers a novel regulatory mechanism of VSMC migration by kaempferol and suggests that miRNA modulation by kaempferol is a potential therapy for cardiovascular diseases.

  1. Differential effects of social and non-social reward on response inhibition in children and adolescents.

    PubMed

    Kohls, Gregor; Peltzer, Judith; Herpertz-Dahlmann, Beate; Konrad, Kerstin

    2009-07-01

    An important issue in the field of clinical and developmental psychopathology is whether cognitive control processes, such as response inhibition, can be specifically enhanced by motivation. To determine whether non-social (i.e. monetary) and social (i.e. positive facial expressions) rewards are able to differentially improve response inhibition accuracy in typically developing children and adolescents, an 'incentive' go/no-go task was applied with reward contingencies for successful inhibition. In addition, the impact of children's personality traits (such as reward seeking and empathy) on monetary and social reward responsiveness was assessed in 65 boys, ages 8 to 12 years. All subjects were tested twice: At baseline, inhibitory control was assessed without reward, and then subjects were pseudorandomly assigned to one of four experimental conditions, including (1) social reward only, (2) monetary reward only, (3) mixed social and monetary reward, or (4) a retest condition without reward. Both social and non-social reward significantly improved task performance, although larger effects were observed for monetary reward. The higher the children scored on reward seeking scales, the larger was their improvement in response inhibition, but only if monetary reward was used. In addition, there was a tendency for an association between empathic skills and benefits from social reward. These data suggest that social incentives do not have an equally strong reinforcing value as compared to financial incentives. However, different personality traits seem to determine to what extent a child profits from different types of reward. Clinical implications regarding probable hyposensitivity to social reward in subjects with autism and dysregulated reward-seeking behaviour in children with attention-deficit/hyperactivity disorder (ADHD) are discussed.

  2. Polychlorinated biphenyl 153 in lipid medium modulates differentiation of human adipocytes.

    PubMed

    Mullerova, D; Pesta, M; Dvorakova, J; Cedikova, M; Kulda, V; Dvorak, P; Bouchalová, V; Kralickova, M; Babuska, V; Kuncova, J; Langmajerova, J; Muller, L

    2017-04-12

    Emerging evidence indicates that polychlorinated biphenyls (PCBs) are involved in the development of diabetes mellitus in the obese. The purpose of this study was to determine mechanisms by which PCB 153 (2,2´,4,4´,5,5´-hexachlorobiphenyl) could influence diet-induced obesity and insulin resistance during adipogenesis. Lineage of h-ADMSCs was differentiated either as control (differentiation medium only), or with lipid vehicle modelling high fat nutrition (NuTRIflex) or lipid free vehicle (dimethylsulfoxide) for 28 days with or without PCB 153 daily co-exposure (in three concentrations 0.1, 1, and 10 microM). Gene expression analyses were performed using RT-qPCR at days 4, 10, 21, 24, 28; protein levels Akt and phosphorylated Akt (Phospho-Akt) by Western blot at days 4, and 21. PCB 153 treatment of h-ADMSCs only in lipid vehicle was associated with down regulation of key master genes of adipogenesis: PPARgamma, SREBP-1, PPARGC1B, and PLIN2 during the whole process of differentiation; and with increased Akt and decreased Phospho-Akt protein level at day 21. We have shown that PCB 153, in concentration 0.1 microM, has a potential in lipid rich environment to modulate differentiation of adipocytes. Because European and U.S. adults have been exposed to PCB 153, this particular nutrient-toxicant interaction potentially impacts human obesity and insulin sensitivity.

  3. Modulation of the differentiation of dental pulp stem cells by different concentrations of β-glycerophosphate.

    PubMed

    Liu, Mingyue; Sun, Yao; Liu, Yang; Yuan, Mengtong; Zhang, Zhihui; Hu, Weiping

    2012-01-31

    Dentinogenesis is a necessary prerequisite for dental tissue engineering. One of the steps for dentinogenesis is to obtain large quantities of highly purified odontoblasts. Therefore, we have undertaken an experiment applying different concentrations of β-glycerophosphate (β-GP) to induce the differentiation of dental pulp stem cells (DPSCs) in a long-term 28-day culture. In the meanwhile, we have studied the time- and maturation-dependent expression of matrix extracellular phosphoglycoprotein (MEPE) and that of the odontoblast-like marker-dentin sialoprotein (DSP), in order to investigate an optimized mineralized condition. Western blot results revealed that the expression of DSP became lower when accompanied by the increase of the β-GP concentration, and there was also an influence on MEPE expression when different concentrations of β-GP were applied. Meanwhile, the mineralized groups had an inhibitory function on the expression of MEPE as compared with the control group. Above all, all experimental groups successfully generated mineralized nodules by Alizarin Red S and the 5 mM β-GP group formed more mineralized nodules quantitated using the CPC extraction method. In conclusion, there is a significant modulation of the β-GP during the differentiation of the DPSCs. The degree of odontoblast differentiation is β-glycerophosphate concentration dependent. A low concentration of β-GP (5 mM) has been shown to be the optimal concentration for stimulating the maturation of the DPSCs. Moreover, MEPE accompanied with DSP clearly demonstrates the degree of the differentiation.

  4. miR-25 modulates NSCLC cell radio-sensitivity through directly inhibiting BTG2 expression

    SciTech Connect

    He, Zhiwei Liu, Yi Xiao, Bing Qian, Xiaosen

    2015-02-13

    A large proportion of the NSCLC patients were insensitive to radiotherapy, but the exact mechanism is still unclear. This study explored the role of miR-25 in regulating sensitivity of NSCLC cells to ionizing radiation (IR) and its downstream targets. Based on measurement in tumor samples from NSCLC patients, this study found that miR-25 expression is upregulated in both NSCLC and radio-resistant NSCLC patients compared the healthy and radio-sensitive controls. In addition, BTG expression was found negatively correlated with miR-25a expression in the both tissues and cells. By applying luciferase reporter assay, we verified two putative binding sites between miR-25 and BTG2. Therefore, BTG2 is a directly target of miR-25 in NSCLC cancer. By applying loss-and-gain function analysis in NSCLC cell lines, we demonstrated that miR-25-BTG2 axis could directly regulated BTG2 expression and affect radiotherapy sensitivity of NSCLC cells. - Highlights: • miR-25 is upregulated, while BTG2 is downregulated in radioresistant NSCLC patients. • miR-25 modulates sensitivity to radiation induced apoptosis. • miR-25 directly targets BTG2 and suppresses its expression. • miR-25 modulates sensitivity to radiotherapy through inhibiting BTG2 expression.

  5. Modulation of mesangial cell migration by extracellular matrix components. Inhibition by heparinlike glycosaminoglycans

    SciTech Connect

    Person, J.M.; Lovett, D.H.; Raugi, G.J.

    1988-12-01

    Extension of mesangial cells (MC) into the pericapillary space is a pathologic response seen in several forms of glomerulonephritis. This process may involve both cytoplasmic extension by MC and actual cellular migration. For investigation of whether extracellular matrix factors could modulate this process, the migratory responses of rat MC were quantitatively examined using a cell culture model. Denuding (wounding) a portion of a confluent culture of MC was followed by migration of mesangial cells into the denuded area. The expected proliferative response to this treatment was blocked by irradiation. The migratory response began within 8 hours of wounding and continued for at least 80 hours. The MC migratory response was specifically inhibited in a dose-dependent and reversible manner by heparin and heparinlike glycosaminoglycans (GAGs). Chondroitin sulfates and hyaluronic acid did not significantly inhibit MC migration. Glomerular basement membrane heparinlike GAGs may normally prevent MC extension into the pericapillary space. Changes in the density or composition of these substances during glomerular inflammatory processes could permit the development of MC pericapillary extensions and thereby lead to further alterations in basement membrane integrity.

  6. Ginseng Protects Against Respiratory Syncytial Virus by Modulating Multiple Immune Cells and Inhibiting Viral Replication

    PubMed Central

    Lee, Jong Seok; Lee, Yu-Na; Lee, Young-Tae; Hwang, Hye Suk; Kim, Ki-Hye; Ko, Eun-Ju; Kim, Min-Chul; Kang, Sang-Moo

    2015-01-01

    Ginseng has been used in humans for thousands of years but its effects on viral infection have not been well understood. We investigated the effects of red ginseng extract (RGE) on respiratory syncytial virus (RSV) infection using in vitro cell culture and in vivo mouse models. RGE partially protected human epithelial (HEp2) cells from RSV-induced cell death and viral replication. In addition, RGE significantly inhibited the production of RSV-induced pro-inflammatory cytokine (TNF-α) in murine dendritic and macrophage-like cells. More importantly, RGE intranasal pre-treatment prevented loss of mouse body weight after RSV infection. RGE treatment improved lung viral clearance and enhanced the production of interferon (IFN-γ) in bronchoalveolar lavage cells upon RSV infection of mice. Analysis of cellular phenotypes in bronchoalveolar lavage fluids showed that RGE treatment increased the populations of CD8+ T cells and CD11c+ dendritic cells upon RSV infection of mice. Taken together, these results provide evidence that ginseng has protective effects against RSV infection through multiple mechanisms, which include improving cell survival, partial inhibition of viral replication and modulation of cytokine production and types of immune cells migrating into the lung. PMID:25658239

  7. Caffeine inhibits adipogenesis through modulation of mitotic clonal expansion and the AKT/GSK3 pathway in 3T3-L1 adipocytes.

    PubMed

    Kim, Ah-Reum; Yoon, Bo Kyung; Park, Hyounkyoung; Seok, Jo Woon; Choi, Hyeonjin; Yu, Jung Hwan; Choi, Yoonjeong; Song, Su Jin; Kim, Ara; Kim, Jae-Woo

    2016-02-01

    Caffeine has been proposed to have several beneficial effects on obesity and its related metabolic diseases; however, how caffeine affects adipocyte differentiation has not been elucidated. In this study, we demonstrated that caffeine suppressed 3T3-L1 adipocyte differentiation and inhibited the expression of CCAAT/enhancer binding protein (C/EBP)α and peroxisome proliferator-activated receptor (PPAR)γ, two main adipogenic transcription factors. Anti-adipogenic markers, such as preadipocyte secreted factor (Pref)-1 and Krüppel-like factor 2, remained to be expressed in the presence of caffeine. Furthermore, 3T3-L1 cells failed to undergo typical mitotic clonal expansion in the presence of caffeine. Investigation of hormonal signaling revealed that caffeine inhibited the activation of AKT and glycogen synthase kinase (GSK) 3 in a dose-dependent manner, but not extracellular signal-regulated kinase (ERK). Our data show that caffeine is an anti-adipogenic bioactive compound involved in the modulation of mitotic clonal expansion during adipocyte differentiation through the AKT/GSK3 pathway. [BMB Reports 2016; 49(2): 111-115].

  8. Lithium Reversibly Inhibits Schwann Cell Proliferation and Differentiation Without Inducing Myelin Loss.

    PubMed

    Piñero, Gonzalo; Berg, Randall; Andersen, Natalia Denise; Setton-Avruj, Patricia; Monje, Paula Virginia

    2016-12-05

    This study was undertaken to examine the bioactivity, specificity, and reversibility of lithium's action on the growth, survival, proliferation, and differentiation of cultured Schwann cells (SCs). In isolated SCs, lithium promoted a state of cell cycle arrest that featured extensive cell enlargement and c-Jun downregulation in the absence of increased expression of myelin-associated markers. In addition, lithium effectively prevented mitogen-induced S-phase entry without impairing cell viability. When lithium was administered together with differentiating concentrations of cyclic adenosine monophosphate (cAMP) analogs, a dramatic inhibition of the expression of the master regulator of myelination Krox-20 was observed. Likewise, lithium antagonized the cAMP-dependent expression of various myelin markers such as protein zero, periaxin, and galactocerebroside and allowed SCs to maintain high levels of expression of immature SC markers even in the presence of high levels of cAMP and low levels of c-Jun. Most importantly, the inhibitory action of lithium on SC proliferation and differentiation was shown to be dose dependent, specific, and reversible upon removal of lithium compounds. In SC-neuron cultures, lithium suppressed myelin sheath formation while preserving axonal integrity, SC-axon contact, and basal lamina formation. Lithium was unique in its ability to prevent the onset of myelination without promoting myelin degradation or SC dedifferentiation. To conclude, our results underscored an unexpected antagonistic action of lithium on SC mitogenesis and myelin gene expression. We suggest that lithium represents an attractive pharmacological agent to safely and reversibly suppress the onset of SC proliferation, differentiation, and myelination while maintaining the integrity of pre-existing myelinated fibers.

  9. Inhibition of in vitro limb cartilage differentiation by syndecan-3 antibodies.

    PubMed

    Seghatoleslami, M R; Kosher, R A

    1996-09-01

    The transmembrane heparan sulfate proteoglycan syndecan-3 is transiently expressed in high amounts during the cellular condensation process that characterizes the onset of limb cartilage differentiation. During condensation, limb mesenchymal cells become closely juxtaposed and undergo cell-cell and cell-matrix interactions that are necessary to trigger cartilage differentiation and cartilage-specific gene expression. To test directly the possible involvement of syndecan-3 in regulating the onset of limb chondrogenesis, we examined the effect of polyclonal antibodies against a syndecan-3 fusion protein on the chondrogenic differentiation of chick limb mesenchymal cells in micromass culture. Syndecan-3 antiserum elicits a dose-dependent inhibition of the accumulation of Alcian blue-stainable cartilage matrix by high density limb mesenchymal cell micromass cultures (2 x 10(5) cells/10 microliters) and a corresponding reduction in steady-state levels of mRNAs for cartilage-characteristic type II collagen and the core protein of the cartilage proteoglycan aggrecan. In preimmune serum-treated control cultures proliferating cells are limited to the periphery of areas of cartilage matrix deposition, whereas large numbers of proliferating cells are uniformly distributed throughout the undifferentiated cultures supplemented with syndecan-3 antiserum. Limb mesenchymal cells cultured at lower densities (1 x 10(5) cells/10 microliters) in the presence of preimmune serum form extensive precartilage condensations characterized by the close juxtaposition of rounded cells by day 2 of culture. In contrast, in the presence of syndecan-3 antiserum, the cells fail to aggregate but rather remain flattened and spatially separated from one another, suggeting that syndecan-3 antibodies impair the formation of precartilage condensations. These results indicate that syndecan-3 plays an important role in regulating the onset of limb chondrogenesis, perhaps by mediating the cell-cell and cell

  10. Oxidative stress modulates the cytokine response of differentiated Th17 and Th1 cells.

    PubMed

    Abimannan, Thiruvaimozhi; Peroumal, Doureradjou; Parida, Jyoti R; Barik, Prakash K; Padhan, Prasanta; Devadas, Satish

    2016-10-01

    Reactive oxygen species (ROS) signaling is critical in T helper (Th) cell differentiation; however its role in differentiated Th cell functions is unclear. In this study, we investigated the role of oxidative stress on the effector functions of in vitro differentiated mouse Th17 and Th1 cells or CD4(+) T cells from patients with Rheumatoid Arthritis using pro-oxidants plumbagin (PB) and hydrogen peroxide. We found that in mouse Th cells, non-toxic concentration of pro-oxidants inhibited reactivation induced expression of IL-17A in Th17 and IFN-γ in Th1 cells by reducing the expression of their respective TFs, RORγt and T-bet. Interestingly, in both the subsets, PB increased the expression of IL-4 by enhancing reactivation induced ERK1/2 phosphorylation. We further investigated the cytokine modulatory effect of PB on CD4(+) T cells isolated from PBMCs of patients with Rheumatoid Arthritis, a well-known Th17 and or Th1 mediated disease. In human CD4(+) T cells from Rheumatoid Arthritis patients, PB reduced the frequencies of IL-17A(+) (Th17), IFN(-)γ(+) (Th1) and IL-17A(+)/IFN(-)γ(+) (Th17/1) cells and also inhibited the production of pro-inflammatory cytokines TNF-α and IL-6. N-Acetyl Cysteine (NAC) an antioxidant completely reversed PB mediated cytokine modulatory effects in both mouse and human cells indicating a direct role for ROS. Together our data suggest that oxidative microenvironment can alter cytokine response of terminally differentiated cells and thus altering intracellular ROS could be a potential way to target Th17 and Th1 cells in autoimmune disorders.

  11. Differential modulation of Bordetella pertussis virulence genes as evidenced by DNA microarray analysis.

    PubMed

    Hot, D; Antoine, R; Renauld-Mongénie, G; Caro, V; Hennuy, B; Levillain, E; Huot, L; Wittmann, G; Poncet, D; Jacob-Dubuisson, F; Guyard, C; Rimlinger, F; Aujame, L; Godfroid, E; Guiso, N; Quentin-Millet, M-J; Lemoine, Y; Locht, C

    2003-07-01

    The production of most factors involved in Bordetella pertussis virulence is controlled by a two-component regulatory system termed BvgA/S. In the Bvg+ phase virulence-activated genes (vags) are expressed, and virulence-repressed genes (vrgs) are down-regulated. The expression of these genes can also be modulated by MgSO(4) or nicotinic acid. In this study we used microarrays to analyse the influence of BvgA/S or modulation on the expression of nearly 200 selected genes. With the exception of one vrg, all previously known vags and vrgs were correctly assigned as such, and the microarray analyses identified several new vags and vrgs, including genes coding for putative autotransporters, two-component systems, extracellular sigma factors, the adenylate cyclase accessory genes cyaBDE, and two genes coding for components of a type III secretion system. For most of the new vrgs and vags the results of the microarray analyses were confirmed by RT-PCR analysis and/or lacZfusions. The degree of regulation and modulation varied between genes, and showed a continuum from strongly BvgA/S-activated genes to strongly BvgA/S-repressed genes. The microarray analyses also led to the identification of a subset of vags and vrgs that are differentially regulated and modulated by MgSO(4) or nicotinic acid, indicating that these genes may be targets for multiple regulatory circuits. For example, the expression of bilA, a gene predicted to encode an intimin-like protein, was found to be activated by BvgA/S and up-modulated by nicotinic acid. Furthermore, surprisingly, in the strain analysed here, which produces only type 2 fimbriae, the fim3 gene was identified as a vrg, while fim2 was confirmed to be a vag.

  12. Galectin-8 promotes regulatory T cell differentiation by modulating IL-2 and TGFβ signaling

    PubMed Central

    Sampson, James F.; Suryawanshi, Amol; Chen, Wei-Sheng; Rabinovich, Gabriel A.; Panjwani, Noorjahan

    2015-01-01

    Galectins have emerged as potent immunoregulatory molecules that control chronic inflammation through distinct mechanisms. Galectin-8 (Gal-8), a tandem-repeat type galectin with unique preference for α2,3-sialylated glycans, is ubiquitously expressed, but little is known about its role in T cell differentiation. Here, we report that Gal-8 promotes the polyclonal differentiation of primary mouse Treg cells in vitro. We further show that Gal-8 also facilitates antigen-specific differentiation of regulatory T (Treg) cells, and that Treg cells polarized in the presence of Gal-8 express cytotoxic T lymphocyte antigen-4 (CTLA-4) and IL-10 at a higher frequency than control Treg cells, and efficiently inhibit proliferation of activated T cells in vitro. Investigation of the mechanism by which Gal-8 promotes Treg conversion revealed that Gal-8 activates TGFβ signaling and promotes sustained IL-2R signaling. Taken together, these data suggest that Gal-8 promotes the differentiation of highly suppressive Treg cells, which has implications for the treatment of inflammatory and autoimmune diseases. PMID:26282995

  13. IL-27 inhibits HIV-1 infection in human macrophages by down-regulating host factor SPTBN1 during monocyte to macrophage differentiation.

    PubMed

    Dai, Lue; Lidie, Kristy B; Chen, Qian; Adelsberger, Joseph W; Zheng, Xin; Huang, DaWei; Yang, Jun; Lempicki, Richard A; Rehman, Tauseef; Dewar, Robin L; Wang, Yanmei; Hornung, Ronald L; Canizales, Kelsey A; Lockett, Stephen J; Lane, H Clifford; Imamichi, Tomozumi

    2013-03-11

    The susceptibility of macrophages to HIV-1 infection is modulated during monocyte differentiation. IL-27 is an anti-HIV cytokine that also modulates monocyte activation. In this study, we present new evidence that IL-27 promotes monocyte differentiation into macrophages that are nonpermissive for HIV-1 infection. Although IL-27 treatment does not affect expression of macrophage differentiation markers or macrophage biological functions, it confers HIV resistance by down-regulating spectrin β nonerythrocyte 1 (SPTBN1), a required host factor for HIV-1 infection. IL-27 down-regulates SPTBN1 through a TAK-1-mediated MAPK signaling pathway. Knockdown of SPTBN1 strongly inhibits HIV-1 infection of macrophages; conversely, overexpression of SPTBN1 markedly increases HIV susceptibility of IL-27-treated macrophages. Moreover, we demonstrate that SPTBN1 associates with HIV-1 gag proteins. Collectively, our results underscore the ability of IL-27 to protect macrophages from HIV-1 infection by down-regulating SPTBN1, thus indicating that SPTBN1 is an important host target to reduce HIV-1 replication in one major element of the viral reservoir.

  14. Apigenin inhibits enterovirus 71 replication through suppressing viral IRES activity and modulating cellular JNK pathway.

    PubMed

    Lv, Xiaowen; Qiu, Min; Chen, Deyan; Zheng, Nan; Jin, Yu; Wu, Zhiwei

    2014-09-01

    Enterovirus 71 (EV71) is a member of genus Enterovirus in Picornaviridae family, which is one of the major causative agents for hand, foot and mouth disease (HFMD), and sometimes associated with severe central nervous system diseases in children. Currently there are no effective therapeutic medicines or vaccines for the disease. In this report, we found that apigenin and luteolin, two flavones that differ only in the number of hydroxyl groups could inhibit EV71-mediated cytopathogenic effect (CPE) and EV71 replication with low cytotoxicity. Both molecules also showed inhibitory effect on the viral polyprotein expression. They prevented EV71-induced cell apoptosis, intracellular reactive oxygen species (ROS) generation and cytokines up-regulation. Time-of-drug addition study demonstrated that apigenin and luteolin acted after viral entry. We examined the effect of apigenin and luteolin on 2A(pro) and 3C(pro) activity, two viral proteases responsible for viral polyprotein processing, and found that they showed less inhibitory activity on 2A(pro) or 3C(pro). Further studies demonstrated that apigenin, but not luteolin could interfere with viral IRES activity. Also, apigenin inhibited EV71-induced c-Jun N-terminal kinase (JNK) activation which is critical for viral replication, in contrast to luteolin that did not. This study demonstrated that apigenin may inhibit EV71 replication through suppressing viral IRES activity and modulating cellular JNK pathway. It also provided evidence that one hydroxyl group difference in the B ring between apigenin and luteolin resulted in the distinct antiviral mechanisms. This study will provide the basis for better drug development and further identification of potential drug targets.

  15. The structure of the Lingo-1 ectodomain, a module implicated in central nervous system repair inhibition.

    PubMed

    Mosyak, Lidia; Wood, Andrew; Dwyer, Brian; Buddha, Madhavan; Johnson, Mark; Aulabaugh, Ann; Zhong, Xiaotian; Presman, Eleonora; Benard, Susan; Kelleher, Kerry; Wilhelm, James; Stahl, Mark L; Kriz, Ron; Gao, Ying; Cao, Zixuan; Ling, Huai-Ping; Pangalos, Menelas N; Walsh, Frank S; Somers, William S

    2006-11-24

    Nogo receptor (NgR)-mediated control of axon growth relies on the central nervous system-specific type I transmembrane protein Lingo-1. Interactions between Lingo-1 and NgR, along with a complementary co-receptor, result in neurite and axonal collapse. In addition, the inhibitory role of Lingo-1 is particularly important in regulation of oligodendrocyte differentiation and myelination, suggesting that pharmacological modulation of Lingo-1 function could be a novel approach for nerve repair and remyelination therapies. Here we report on the crystal structure of the ligand-binding ectodomain of human Lingo-1 and show it has a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. The structure, together with biophysical analysis of its solution properties, reveals that in the crystals and in solution Lingo-1 persistently associates with itself to form a stable tetramer and that it is its LRR-Ig-composite fold that drives such assembly. Specifically, in the crystal structure protomers of Lingo-1 associate in a ring-shaped tetramer, with each LRR domain filling an open cleft in an adjacent protomer. The tetramer buries a large surface area (9,200 A2) and may serve as an efficient scaffold to simultaneously bind and assemble the NgR complex components during activation on a membrane. Potential functional binding sites that can be identified on the ectodomain surface, including the site of self-recognition, suggest a model for protein assembly on the membrane.

  16. Designed modulation of sex steroid signaling inhibits telomerase activity and proliferation of human prostate cancer cells

    SciTech Connect

    Verma, Vikas; Sharma, Vikas; Singh, Vishal; Sharma, Siddharth; Bishnoi, Ajay Kumar; Chandra, Vishal; Maikhuri, J.P.; Dwivedi, Anila; Kumar, Atul; Gupta, Gopal

    2014-10-15

    The predominant estrogen-receptor (ER)-β signaling in normal prostate is countered by increased ER-α signaling in prostate cancer (CaP), which in association with androgen-receptor (AR) signaling results in pathogenesis of the disease. However CaP treatments mostly target AR signaling which is initially effective but eventually leads to androgen resistance, hence simultaneous targeting of ERs has been proposed. A novel series of molecules were designed with multiple sex-steroid receptor modulating capabilities by coalescing the pharmacophores of known anti-CaP molecules that act via modulation of ER(α/β) and/or AR, viz. 3,3′diindolylmethane (DIM), mifepristone, toremifene, tamoxifen and raloxifene. N,N-diethyl-4-((2-(4-methoxyphenyl)-1H-indol-3-yl)methyl) aniline (DIMA) was identified as the most promising structure of this new series. DIMA increased annexin-V labelling, cell-cycle arrest and caspase-3 activity, and decreased expression of AR and prostate specific antigen in LNCaP cells, in vitro. Concurrently, DIMA increased ER-β, p21 and p27 protein levels in LNCaP cells and exhibited ∼ 5 times more selective binding for ER-β than ER-α, in comparison to raloxifene. DIMA exhibited a dose-dependent ER-β agonism and ER-α antagonism in classical gene reporter assay and decreased hTERT (catalytic subunit of telomerase) transcript levels in LNCaP at 3.0 μM (P < 0.05). DIMA also dose-dependently decreased telomerase enzyme activity in prostate cancer cells. It is thus concluded that DIMA acts as a multi-steroid receptor modulator and effectively inhibits proliferation of prostate cancer cells through ER-β mediated telomerase inhibition, by countering actions of ER-α and AR. Its unique molecular design can serve as a lead structure for generation of potent agents against endocrine malignancies like the CaP.

  17. 18{beta}-Glycyrrhetinic acid inhibits adipogenic differentiation and stimulates lipolysis

    SciTech Connect

    Moon, Myung-Hee; Jeong, Jae-Kyo; Lee, You-Jin; Seol, Jae-Won; Ahn, Dong-Choon; Kim, In-Shik; Park, Sang-Youel

    2012-04-20

    Highlights: Black-Right-Pointing-Pointer 18{beta}-GA inhibits adipogenic differentiation in 3T3-L1 preadipocytes and stimulates lipolysis in differentiated adipocytes. Black-Right-Pointing-Pointer Anti-adipogenic effect of 18{beta}-GA is caused by down-regulation of PPAR{gamma} and inactivation of Akt signalling. Black-Right-Pointing-Pointer Lipolytic effect of 18{beta}-GA is mediated by up-regulation of HSL, ATGL and perilipin and activation of HSL. -- Abstract: 18{beta}-Glycyrrhetinic acid (18{beta}-GA) obtained from the herb liquorice has various pharmacological properties including anti-inflammatory and anti-bacterial activities. However, potential biological anti-obesity activities are unclear. In this study, novel biological activities of 18{beta}-GA in the adipogenesis of 3T3-L1 preadipocytes and in lipolysis of differentiated adipocytes were identified. Mouse 3T3-L1 cells were used as an in vitro model of adipogenesis and lipolysis, using a mixture of insulin/dexamethasone/3-isobutyl-1-methylxanthine (IBMX) to induce differentiation. The amount of lipid droplet accumulation was determined by an AdipoRed assay. The expression of several adipogenic transcription factors and enzymes was investigated using real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting. 18{beta}-GA dose-dependently (1-40 {mu}M) significantly decreased lipid accumulation in maturing preadipocytes. In 3T3-L1 preadipocytes, 10 {mu}M of 18{beta}-GA down-regulated the transcriptional levels of the peroxisome proliferator-activated receptor {gamma}, CCAAT/enhancer-binding protein {alpha} and adiponectin, which are markers of adipogenic differentiation via Akt phosphorylation. Also, in differentiated adipocytes, 18{beta}-GA increased the level of glycerol release and up-regulated the mRNA of hormone-sensitive lipase, adipose TG lipase and perilipin, as well as the phosphorylation of hormone-sensitive lipase at Serine 563. The results indicate that 18{beta

  18. Coprinus comatus Cap Inhibits Adipocyte Differentiation via Regulation of PPARγ and Akt Signaling Pathway

    PubMed Central

    Jang, Sun-Hee; Kang, Suk Nam; Jeon, Beong-Sam; Ko, Yeoung-Gyu; Kim, Hong-Duck; Won, Chung-Kil; Kim, Gon-Sup; Cho, Jae-Hyeon

    2014-01-01

    This study assessed the effects of Coprinus comatus cap (CCC) on adipogenesis in 3T3-L1 adipocytes and the effects of CCC on the development of diet-induced obesity in rats. Here, we showed that the CCC has an inhibitory effect on the adipocyte differentiation of 3T3-L1 cells, resulting in a significant decrease in lipid accumulation through the downregulation of several adipocyte specific-transcription factors, including CCAAT/enhancer binding protein β, C/EBPδ, and peroxisome proliferator-activated receptor gamma (PPARγ). Moreover, treatment with CCC during adipocyte differentiation induced a significant down-regulation of PPARγ and adipogenic target genes, including adipocyte protein 2, lipoprotein lipase, and adiponectin. Interestingly, the CCC treatment of the 3T3-L1 adipocytes suppressed the insulin-stimulated Akt and GSK3β phosphorylation, and these effects were stronger in the presence of an inhibitor of Akt phosphorylation, LY294002, suggesting that CCC inhibited adipocyte differentiation through the down-regulation of Akt signaling. In the animal study, CCC administration significantly reduced the body weight and adipose tissue weight of rats fed a high fat diet (HFD) and attenuated lipid accumulation in the adipose tissues of the HFD-induced obese rats. The size of the adipocyte in the epididymal fat of the CCC fed rats was significantly smaller than in the HFD rats. CCC treatment significantly reduced the total cholesterol and triglyceride levels in the serum of HFD rats. These results strongly indicated that the CCC-mediated decrease in body weight was due to a reduction in adipose tissue mass. The expression level of PPARγ and phospho-Akt was significantly lower in the CCC-treated HFD rats than that in the HFD obesity rats. These results suggested that CCC inhibited adipocyte differentiation by the down-regulation of major transcription factor involved in the adipogenesis pathway including PPARγ through the regulation of the Akt pathway in 3T3

  19. Discovery of a JAK3-Selective Inhibitor: Functional Differentiation of JAK3-Selective Inhibition over pan-JAK or JAK1-Selective Inhibition.

    PubMed

    Telliez, Jean-Baptiste; Dowty, Martin E; Wang, Lu; Jussif, Jason; Lin, Tsung; Li, Li; Moy, Erick; Balbo, Paul; Li, Wei; Zhao, Yajuan; Crouse, Kimberly; Dickinson, Caitlyn; Symanowicz, Peter; Hegen, Martin; Banker, Mary Ellen; Vincent, Fabien; Unwalla, Ray; Liang, Sidney; Gilbert, Adam M; Brown, Matthew F; Hayward, Matthew; Montgomery, Justin; Yang, Xin; Bauman, Jonathan; Trujillo, John I; Casimiro-Garcia, Agustin; Vajdos, Felix F; Leung, Louis; Geoghegan, Kieran F; Quazi, Amira; Xuan, Dejun; Jones, Lyn; Hett, Erik; Wright, Katherine; Clark, James D; Thorarensen, Atli

    2016-12-16

    PF-06651600, a newly discovered potent JAK3-selective inhibitor, is highly efficacious at inhibiting γc cytokine signaling, which is dependent on both JAK1 and JAK3. PF-06651600 allowed the comparison of JAK3-selective inhibition to pan-JAK or JAK1-selective inhibition, in relevant immune cells to a level that could not be achieved previously without such potency and selectivity. In vitro, PF-06651600 inhibits Th1 and Th17 cell differentiation and function, and in vivo it reduces disease pathology in rat adjuvant-induced arthritis as well as in mouse experimental autoimmune encephalomyelitis models. Importantly, by sparing JAK1 function, PF-06651600 selectively targets γc cytokine pathways while preserving JAK1-dependent anti-inflammatory signaling such as the IL-10 suppressive functions following LPS treatment in macrophages and the suppression of TNFα and IL-1β production in IL-27-primed macrophages. Thus, JAK3-selective inhibition differentiates from pan-JAK or JAK1 inhibition in various immune cellular responses, which could potentially translate to advantageous clinical outcomes in inflammatory and autoimmune diseases.

  20. Nitric Oxide Donor Molsidomine Positively Modulates Myogenic Differentiation of Embryonic Endothelial Progenitors

    PubMed Central

    Tirone, Mario; Conti, Valentina; Manenti, Fabio; Nicolosi, Pier Andrea; D’Orlando, Cristina; Azzoni, Emanuele

    2016-01-01

    Embryonic VE-Cadherin-expressing progenitors (eVE-Cad+), including hemogenic endothelium, have been shown to generate hematopoietic stem cells and a variety of other progenitors, including mesoangioblasts, or MABs. MABs are vessel-associated progenitors with multilineage mesodermal differentiation potential that can physiologically contribute to skeletal muscle development and regeneration, and have been used in an ex vivo cell therapy setting for the treatment of muscular dystrophy. There is currently a therapeutic need for molecules that could improve the efficacy of cell therapy protocols; one such good candidate is nitric oxide. Several studies in animal models of muscle dystrophy have demonstrated that nitric oxide donors provide several beneficial effects, including modulation of the activity of endogenous cell populations involved in muscle repair and the delay of muscle degeneration. Here we used a genetic lineage tracing approach to investigate whether the therapeutic effect of nitric oxide in muscle repair could derive from an improvement in the myogenic differentiation of eVE-Cad+ progenitors during embryogenesis. We show that early in vivo treatment with the nitric oxide donor molsidomine enhances eVE-Cad+ contribution to embryonic and fetal myogenesis, and that this effect could originate from a modulation of the properties of yolk sac hemogenic endothelium. PMID:27760216

  1. Caspase-3, myogenic transcription factors and cell cycle inhibitors are regulated by leukemia inhibitory factor to mediate inhibition of myogenic differentiation

    PubMed Central

    2011-01-01

    Background Leukemia inhibitory factor (LIF) is known to inhibit myogenic differentiation as well as to inhibit apoptosis and caspase-3 activation in non-differentiating myoblasts. In addition caspase-3 activity is required for myogenic differentiation. Therefore the aim of this study was to further investigate mechanisms of the differentiation suppressing effect of LIF in particular the possibility of a caspase-3 mediated inhibition of differentiation. Results LIF dependent inhibition of differentiation appeared to involve several mechanisms. Differentiating myoblasts that were exposed to LIF displayed increased transcripts for c-fos. Transcripts for the cell cycle inhibitor p21 as well as muscle regulatory factors myoD and myogenin were decreased with LIF exposure. However, LIF did not directly induce a proliferative effect under differentiation conditions, but did prevent the proportion of myoblasts that were proliferating from decreasing as differentiation proceeded. LIF stimulation decreased the percentage of cells positive for active caspase-3 occurring during differentiation. Both the effect of LIF inhibiting caspase-3 activation and differentiation appeared dependent on mitogen activated protein kinase and extracellular signal regulated kinase kinase (MEK) signalling. The role of LIF in myogenic differentiation was further refined to demonstrate that myoblasts are unlikely to secrete LIF endogenously. Conclusions Altogether this study provides a more comprehensive view of the role of LIF in myogenic differentiation including LIF and receptor regulation in myoblasts and myotubes, mechanisms of inhibition of differentiation and the link between caspase-3 activation, apoptosis and myogenic differentiation. PMID:21798094

  2. Anodal transcranial direct current stimulation of the motor cortex induces opposite modulation of reciprocal inhibition in wrist extensor and flexor.

    PubMed

    Lackmy-Vallée, Alexandra; Klomjai, Wanalee; Bussel, Bernard; Katz, Rose; Roche, Nicolas

    2014-09-15

    Transcranial direct current stimulation (tDCS) is used as a noninvasive tool to modulate brain excitability in humans. Recently, several studies have demonstrated that tDCS applied over the motor cortex also modulates spinal neural network excitability and therefore can be used to explore the corticospinal control acting on spinal neurons. Previously, we showed that reciprocal inhibition directed to wrist flexor motoneurons is enhanced during contralateral anodal tDCS, but it is likely that the corticospinal control acting on spinal networks controlling wrist flexors and extensors is not similar. The primary aim of the study was to explore the effects of anodal tDCS on reciprocal inhibition directed to wrist extensor motoneurons. To further examine the supraspinal control acting on the reciprocal inhibition between wrist flexors and extensors, we also explored the effects of the tDCS applied to the ipsilateral hand motor area. In healthy volunteers, we tested the effects induced by sham and anodal tDCS on reciprocal inhibition pathways innervating wrist muscles. Reciprocal inhibition directed from flexor to extensor muscles and the reverse situation, i.e., reciprocal inhibition, directed from extensors to flexors were studied in parallel with the H reflex technique. Our main finding was that contralateral anodal tDCS induces opposing effects on reciprocal inhibition: it decreases reciprocal inhibition directed from flexors to extensors, but it increases reciprocal inhibition directed from extensors to flexors. The functional result of these opposite effects on reciprocal inhibition seems to favor wrist extension excitability, suggesting an asymmetric descending control onto the interneurons that mediate reciprocal inhibition.

  3. K+ Channel Inhibition Differentially Regulates Migration of Intestinal Epithelial Cells in Inflamed vs. Non-Inflamed Conditions in a PI3K/Akt-Mediated Manner

    PubMed Central

    Zundler, Sebastian; Caioni, Massimiliano; Müller, Martina; Strauch, Ulrike; Kunst, Claudia; Woelfel, Gisela

    2016-01-01

    Background Potassium channels have been shown to determine wound healing in different tissues, but their role in intestinal epithelial restitution–the rapid closure of superficial wounds by intestinal epithelial cells (IEC)–remains unclear. Methods In this study, the regulation of IEC migration by potassium channel modulation was explored with and without additional epidermal growth factor (EGF) under baseline and interferon-γ (IFN-γ)-pretreated conditions in scratch assays and Boyden chamber assays using the intestinal epithelial cell lines IEC-18 and HT-29. To identify possibly involved subcellular pathways, Western Blot (WB)-analysis of ERK and Akt phosphorylation was conducted and PI3K and ERK inhibitors were used in scratch assays. Furthermore, mRNA-levels of the potassium channel KCNN4 were determined in IEC from patients suffering from inflammatory bowel diseases (IBD). Results Inhibition of Ca2+-dependent potassium channels significantly increased intestinal epithelial restitution, which could not be further promoted by additional EGF. In contrast, inhibition of KCNN4 after pretreatment with IFN-γ led to decreased or unaffected migration. This effect was abolished by EGF. Changes in Akt, but not in ERK phosphorylation strongly correlated with these findings and PI3K but not ERK inhibition abrogated the effect of KCNN4 inhibition. Levels of KCNN4 mRNA were higher in samples from IBD patients compared with controls. Conclusions Taken together, we demonstrate that inhibition of KCNN4 differentially regulates IEC migration in IFN-γ-pretreated vs. non pretreated conditions. Moreover, our data propose that the PI3K signaling cascade is responsible for this differential regulation. Therefore, we present a cellular model that contributes new aspects to epithelial barrier dysfunction in chronic intestinal inflammation, resulting in propagation of inflammation and symptoms like ulcers or diarrhea. PMID:26824610

  4. Inhibition of adipogenic differentiation of bone marrow mesenchymal stem cells by erythropoietin via activating ERK and P38 MAPK.

    PubMed

    Liu, G X; Zhu, J C; Chen, X Y; Zhu, A Z; Liu, C C; Lai, Q; Chen, S T

    2015-06-26

    We examined whether erythropoietin (EPO) can inhibit adipogenic differentiation of mesenchymal stem cells (MSCs) in the mouse bone marrow and its underlying mechanism. We separated and extracted mouse bone marrow MSCs and induced adipogenic differen-tiation using 3-isobutyl-1-methylxanthine, insulin, and dexamethasone. Different concentrations of EPO were added to the cells and observed by Oil Red O staining on the 20th day to quantitatively analyze the degree of cell differentiation. mRNA expression levels of peroxysome proliferator-activated receptor γ (PPARγ), CCAAT enhancer binding protein α, and adiponectin were analyzed by real-time quantitative polymerase chain reaction, and the activity of PPARγ, extracellular sig-nal-regulated kinase (ERK), and p38 mitogen-activated protein kinase (p38 MAPK) were determined by western blotting. EPO significantly inhibited adipogenic differentiation of MSCs after 20 days and reduced absorbance values by Oil Red O staining without affecting proliferation activity. EPO downregulated the mRNA expression of PPARγ, CCAAT enhancer binding protein α, fatty acid binding protein 4, and adiponec-tin during adipogenesis and increased protein phosphorylation of ERK, p38 MAPK, and PPARγ during differentiation. EPO downregulated the mRNA expression of PPARγ, CCAAT enhancer binding protein α, fatty acid binding protein 4, and adiponectin by increasing protein phosphor-ylation of ERK, p38 MAPK, and PPARγ during differentiation, which inhibited adipogenic differentiation of MSCs.

  5. Inhibition of mitotic clonal expansion mediates fisetin-exerted prevention of adipocyte differentiation in 3T3-L1 cells.

    PubMed

    Lee, Youngyi; Bae, Eun Ju

    2013-11-01

    Adipocytes are the key player in adipose tissue inflammation and subsequent systemic insulin resistance and its development involves complex process of proliferation and differentiation of preadipocytes. Fistein, a polyphenol flavonoid, is known to exert anti-inflammatory, anti-carcinogenic and anti-diabetic effects. In this study, we aimed to investigate the effect of fisetin on adipocyte proliferation and differentiation in 3T3-L1 preadipocyte cell line and its mechanism of action. We found that fisetin inhibits adipocyte differentiation in a concentration dependent manner, which were evidenced by Oil Red O staining and the protein expression of mature adipocyte marker genes fatty acid synthase and peroxisome proliferator-activated receptor γ. Moreover, the proliferation of preadipocytes was also markedly suppressed by treatment of fisetin for 24 and 48 h in the differentiation medium. We also found that fisetin inhibition of adipocyte differentiation was largely due to the effect on mitotic clonal expansion. Fisetin suppression of preadipocyte proliferation at early stage of differentiation was accompanied by the changes of expression of a series of cell cycle regulatory proteins. Altogether, our results suggest that the inhibition of adipocyte differentiation by fisetin may be at least in part mediated by cell cycle arrest during adipogenesis.

  6. Ethacrynic acid and 1 alpha,25-dihydroxyvitamin D3 cooperatively inhibit proliferation and induce differentiation of human myeloid leukemia cells.

    PubMed

    Makishima, M; Honma, Y

    1996-09-01

    The active form of vitamin D, 1 alpha,25-dihydroxyvitamin D3 (VD3), inhibits proliferation and induces differentiation of leukemia cells, but its clinical use is limited by the adverse effect of hypercalcemia. In this study we found that the loop diuretic ethacrynic acid, which is used to treat hypercalcemia, enhanced the differentiation of human leukemia cells induced by VD3. Ethacrynic acid alone inhibited the proliferation of human promyelocytic HL-60 cells while only slightly increasing differentiation markers such as nitroblue tetrazolium (NBT)-reducing and lysozyme activities. Ethacrynic acid effectively enhanced the growth-inhibiting action of VD3. In the presence of ethacrynic acid, VD3 increased the NBT-reducing and lysozyme activities and the CD11b expression of HL-60 cells more effectively than VD3 alone. Other loop diuretics, furosemide and bumetanide, also enhanced the differentiation of HL-60 cells induced by VD3, but to a lesser extent than ethacrynic acid. The differentiation of HL-60 cells induced by all-trans retinoic acid, dimethyl sulfoxide or phorbol-12-myristate 13-acetate was also enhanced by ethacrynic acid with increasing NBT-reducing and lysozyme activities and the expression of CD11b or CD14 surface antigen. Morphologically, ethacrynic acid enhanced the monocytic differentiation of HL-60 cells induced by VD3 and phorbol ester and the granulocytic differentiation by retinoic acid and dimethyl sulfoxide. Other human myelomonocytic leukemia ML-1, U937, P39/TSU and P31/FUJ cells were induced to differentiate by VD3 and this was also enhanced by ethacrynic acid. The long-term culture of HL-60 cells showed that ethacrynic acid plus VD3 induced the complete growth arrest of HL-60 cells. Therefore ethacrynic acid, which is used to treat hypercalcemia, enhanced the proliferation-inhibiting and differentiation-inducing activities of VD3 and the combination of ethacrynic acid and VD3 may be useful in therapy for myeloid leukemia.

  7. Dioscin inhibits osteoclast differentiation and bone resorption though down-regulating the Akt signaling cascades

    SciTech Connect

    Qu, Xinhua; Zhai, Zanjing; Liu, Xuqiang; Li, Haowei; Ouyang, Zhengxiao; Wu, Chuanlong; Liu, Guangwang; Fan, Qiming; Tang, Tingting; Qin, An; Dai, Kerong

    2014-01-10

    Highlights: •A natural-derived compound, dioscin, suppresses osteoclast formation and bone resorption. •Dioscin inhibits osteolytic bone loss in vivo. •Dioscin impairs the Akt signaling cascades pathways during osteoclastogenesis. •Dioscin have therapeutic value in treating osteoclast-related diseases. -- Abstract: Bone resorption is the unique function of osteoclasts (OCs) and is critical for both bone homeostasis and pathologic bone diseases including osteoporosis, rheumatoid arthritis and tumor bone metastasis. Thus, searching for natural compounds that may suppress osteoclast formation and/or function is promising for the treatment of osteoclast-related diseases. In this study, we for the first time demonstrated that dioscin suppressed RANKL-mediated osteoclast differentiation and bone resorption in vitro in a dose-dependent manner. The suppressive effect of dioscin is supported by the reduced expression of osteoclast-specific markers. Further molecular analysis revealed that dioscin abrogated AKT phosphorylation, which subsequently impaired RANKL-induced nuclear factor-kappaB (NF-κB) signaling pathway and inhibited NFATc1 transcriptional activity. Moreover, in vivo studies further verified the bone protection activity of dioscin in osteolytic animal model. Together our data demonstrate that dioscin suppressed RANKL-induced osteoclast formation and function through Akt signaling cascades. Therefore, dioscin is a potential natural agent for the treatment of osteoclast-related diseases.

  8. Clostridium perfringens α-Toxin Impairs Innate Immunity via Inhibition of Neutrophil Differentiation

    PubMed Central

    Takehara, Masaya; Takagishi, Teruhisa; Seike, Soshi; Ohtani, Kaori; Kobayashi, Keiko; Miyamoto, Kazuaki; Shimizu, Tohru; Nagahama, Masahiro

    2016-01-01

    Although granulopoiesis is accelerated to suppress bacteria during infection, some bacteria can still cause life-threatening infections, but the mechanism behind this remains unclear. In this study, we found that mature neutrophils in bone marrow cells (BMCs) were decreased in C. perfringens-infected mice and also after injection of virulence factor α-toxin. C. perfringens infection interfered with the replenishment of mature neutrophils in the peripheral circulation and the accumulation of neutrophils at C. perfringens-infected sites in an α-toxin-dependent manner. Measurements of bacterial colony-forming units in C. perfringens-infected muscle revealed that α-toxin inhibited a reduction in the load of C. perfringens. In vitro treatment of isolated BMCs with α-toxin (phospholipase C) revealed that α-toxin directly decreased mature neutrophils. α-Toxin did not influence the viability of isolated mature neutrophils, while simultaneous treatment of BMCs with granulocyte colony-stimulating factor attenuated the reduction of mature neutrophils by α-toxin. Together, our results illustrate that impairment of the innate immune system by the inhibition of neutrophil differentiation is crucial for the pathogenesis of C. perfringens to promote disease to a life-threatening infection, which provides new insight to understand how pathogenic bacteria evade the host immune system. PMID:27306065

  9. Paeoniflorin Ameliorates Experimental Autoimmune Encephalomyelitis via Inhibition of Dendritic Cell Function and Th17 Cell Differentiation

    PubMed Central

    Zhang, Han; Qi, Yuanyuan; Yuan, Yuanyang; Cai, Li; Xu, Haiyan; Zhang, Lili; Su, Bing; Nie, Hong

    2017-01-01

    Paeoniflorin (PF) is a monoterpene glycoside and exhibits multiple effects, including anti-inflammation and immunoregulation. To date, the effect of PF on multiple sclerosis (MS) has not been investigated. In this study, we investigated the effect of PF in experimental autoimmune encephalomyelitis (EAE), an animal model for MS. After administered with PF, the onset and clinical symptoms of EAE mice were significantly ameliorated, and the number of Th17 cells infiltrated in central nervous system (CNS) and spleen was also dramatically decreased. Instead of inhibiting the differentiation of Th17 cells directly, PF influenced Th17 cells via suppressing the expression of costimulatory molecules and the production of interlukin-6 (IL-6) of dendritic cells (DCs) in vivo and in vitro, which may be attributable to the inhibition of IKK/NF-κB and JNK signaling pathway. When naïve CD4+ T cells were co-cultured with PF-treated dendritic cells under Th17-polarizing condition, the percentage of Th17 cells and the phosphorylation of STAT3 were decreased, as well as the mRNA levels of IL-17, RORα, and RORγt. Our study provided insights into the role of PF as a unique therapeutic agent for the treatment of multiple sclerosis and illustrated the underlying mechanism of PF from a new perspective. PMID:28165507

  10. NOTCH SIGNALLING MODULATES HYPOXIA-INDUCED NEUROENDOCRINE DIFFERENTIATION OF HUMAN PROSTATE CANCER CELLS

    PubMed Central

    Danza, Giovanna; Di Serio, Claudia; Rosati, Fabiana; Lonetto, Giuseppe; Sturli, Niccolò; Kacer, Doreen; Pennella, Antonio; Ventimiglia, Giuseppina; Barucci, Riccardo; Piscazzi, Annamaria; Prudovsky, Igor; Landriscina, Matteo; Marchionni, Niccolò; Tarantini, Francesca

    2012-01-01

    Prostate carcinoma is among the most common causes of cancer-related death in men, representing 15% of all male malignancies in developed countries. Neuroendocrine differentiation has been associated with tumor progression, poor prognosis and with the androgen-independent status. Currently, no successful therapy exists for advanced, castration-resistant disease. Because hypoxia has been linked to prostate cancer progression and unfavourable outcome, we sought to determine whether hypoxia would impact the degree of neuroendocrine differentiation of prostate cancer cells, in vitro. Results exposure of LNCaP cells to low oxygen tension induced a neuroendocrine phenotype, associated with an increased expression of the transcription factor neurogenin3 and neuroendocrine markers, such as neuron-specific enolase, chromogranin A and β3-tubulin. Moreover, hypoxia triggered a significant decrease of Notch 1 and Notch 2 mRNA and protein expression, with subsequent down regulation of Notch-mediated signalling, as demonstrated by reduced levels of the Notch target genes, Hes1 and Hey1. Neuroendocrine differentiation was promoted by attenuation of Hes1 transcription, as cells expressing a dominant negative form of Hes1 displayed increased levels of neuroendocrine markers under normoxic conditions. Although hypoxia down regulated Notch 1 and Notch 2 mRNA transcription and receptor activation also in the androgen independent cell lines, PC3 and Du145, it did not change the extent of NE differentiation in these cultures, suggesting that androgen sensitivity may be required for transdifferentiation to occur. Conclusions hypoxia induces neuroendocrine differentiation of LNCaP cells in vitro, which appears to be driven by the inhibition of Notch signalling with subsequent down-regulation of Hes1 transcription. PMID:22172337

  11. Interferon-γ differentially modulates the impact of tumor necrosis factor-α on human endometrial stromal cells.

    PubMed

    Spratte, Julia; Oemus, Anne; Zygmunt, Marek; Fluhr, Herbert

    2015-09-01

    The pro-inflammatory T helper (Th)-1 cytokines, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), are immunological factors relevant at the feto-maternal interface and involved in the pathophysiology of implantation disorders. The synergistic action of the two cytokines has been described with regard to apoptotic cell death and inflammatory responses in different cell types, but little is known regarding the human endometrium. Therefore, we examined the interaction of TNF-α and IFN-γ in human endometrial stromal cells (ESCs). ESCs were isolated from specimens obtained during hysterectomy and decidualized in vitro. Cells were incubated with TNF-α, IFN-γ or signaling-inhibitor. Insulin-like growth factor binding protein (IGFBP)-1, prolactin (PRL), leukemia inhibitory factor (LIF), interleukin (IL)-6, IL-8, regulated on activation normal T-cell expressed and secreted protein (RANTES) and monocyte chemotactic protein (MCP)-1 were measured using ELISA and real-time RT-PCR. Nuclear factor of transcription (NF)-κB and its inhibitor (IκBα) were analyzed by in-cell western assay and transcription factor assay. TNF-α inhibited and IFN-γ did not affect the decidualization of ESCs. In contrast, IFN-gamma differentially modulated the stimulating effect of TNF-alpha on cytokines by enhancing IL-6, RANTES and MCP-1 and attenuating LIF mRNA expression. These effects were time- and dose-dependent. IFN-γ had no impact on the initial activation of NF-κB signaling. Histone-deacetylase activity was involved in the modulating effect of IFN-γ on RANTES secretion. These observations showed a distinct pattern of interaction of the Th-1 cytokines, TNF-α and IFN-γ in the human endometrium, which could play an important role in the pathophysiology of implantation disorders.

  12. Roflumilast Inhibits Respiratory Syncytial Virus Infection in Human Differentiated Bronchial Epithelial Cells

    PubMed Central

    Mata, Manuel; Martinez, Isidoro; Melero, Jose A.; Tenor, Herman; Cortijo, Julio

    2013-01-01

    Respiratory syncytial virus (RSV) causes acute exacerbations in COPD and asthma. RSV infects bronchial epithelial cells (HBE) that trigger RSV associated lung pathology. This study explores whether the phosphodiesterase 4 (PDE4) inhibitor Roflumilast N-oxide (RNO), alters RSV infection of well-differentiated HBE (WD-HBE) in vitro. WD-HBE were RSV infected in the presence or absence of RNO (0.1-100 nM). Viral infection (staining of F and G proteins, nucleoprotein RNA level), mRNA of ICAM-1, ciliated cell markers (digital high speed videomicroscopy, β-tubulin immunofluorescence, Foxj1 and Dnai2 mRNA), Goblet cells (PAS), mRNA of MUC5AC and CLCA1, mRNA and protein level of IL-13, IL-6, IL-8, TNFα, formation of H2O2 and the anti-oxidative armamentarium (mRNA of Nrf2, HO-1, GPx; total antioxidant capacity (TAC) were measured at day 10 or 15 post infection. RNO inhibited RSV infection of WD-HBE, prevented the loss of ciliated cells and markers, reduced the increase of MUC5AC and CLCA1 and inhibited the increase of IL-13, IL-6, IL-8, TNFα and ICAM-1. Additionally RNO reversed the reduction of Nrf2, HO-1 and GPx mRNA levels and consequently restored the TAC and reduced the H2O2 formation. RNO inhibits RSV infection of WD-HBE cultures and mitigates the cytopathological changes associated to this virus. PMID:23936072

  13. mir-300 promotes self-renewal and inhibits the differentiation of glioma stem-like cells.

    PubMed

    Zhang, Daming; Yang, Guang; Chen, Xin; Li, Chunmei; Wang, Lu; Liu, Yaohua; Han, Dayong; Liu, Huailei; Hou, Xu; Zhang, Weiguang; Li, Chenguang; Han, Zhanqiang; Gao, Xin; Zhao, Shiguang

    2014-08-01

    MicroRNAs (miRNAs) are small noncoding RNAs that have been critically implicated in several human cancers. miRNAs are thought to participate in various biological processes, including proliferation, cell cycle, apoptosis, and even the regulation of the stemness properties of cancer stem cells. In this study, we explore the potential role of miR-300 in glioma stem-like cells (GSLCs). We isolated GSLCs from glioma biopsy specimens and identified the stemness properties of the cells through neurosphere formation assays, multilineage differentiation ability analysis, and immunofluorescence analysis of glioma stem cell markers. We found that miR-300 is commonly upregulated in glioma tissues, and the expression of miR-300 was higher in GSLCs. The results of functional experiments demonstrated that miR-300 can enhance the self-renewal of GSLCs and reduce differentiation toward both astrocyte and neural fates. In addition, LZTS2 is a direct target of miR-300. In conclusion, our results demonstrate the critical role of miR-300 in GSLCs and its functions in LZTS2 inhibition and describe a new approach for the molecular regulation of tumor stem cells.

  14. Gallium nitrate inhibits alkaline phosphatase activity in a differentiating mesenchymal cell culture.

    PubMed

    Boskey, A L; Ziecheck, W; Guidon, P; Doty, S B

    1993-02-01

    The effect of gallium nitrate on alkaline phosphatase activity in a differentiating chick limb-bud mesenchymal cell culture was monitored in order to gain insight into the observation that rachitic rats treated with gallium nitrate failed to show the expected increase in serum alkaline phosphatase activity. Cultures maintained in media containing 15 microM gallium nitrate showed drastically decreased alkaline phosphatase activities in the absence of significant alterations in total protein synthesis and DNA content. However, addition of 15 microM gallium nitrate to cultures 18 h before assay for alkaline phosphatase activity had little effect. At the light microscopic and electron microscopic level, gallium-treated cultures differed morphologically from gallium-free cultures: with gallium present, there were fewer hypertrophic chondrocytes and cartilage nodules were flatter and further apart. Because of altered morphology, staining with an antibody against chick cartilage alkaline phosphatase appeared less extensive; however, all nodules stained equivalently relative to gallium-free controls. Histochemical staining for alkaline phosphatase activity was negative in gallium-treated cultures, demonstrating that the alkaline phosphatase protein present was not active. The defective alkaline phosphatase activity in cultures maintained in the presence of gallium was also evidenced when cultures were supplemented with the alkaline phosphatase substrate, beta-glycerophosphate (beta GP). The data presented suggest that gallium inhibits alkaline phosphatase activity in this culture system and that gallium causes alterations in the differentiation of mesenchymal cells into hypertrophic chondrocytes.

  15. Targeting Notch pathway induces growth inhibition and differentiation of neuroblastoma cells.

    PubMed

    Ferrari-Toninelli, Giulia; Bonini, Sara Anna; Uberti, Daniela; Buizza, Laura; Bettinsoli, Paola; Poliani, Pietro Luigi; Facchetti, Fabio; Memo, Maurizio

    2010-12-01

    High-risk neuroblastoma is a severe pediatric tumor characterized by poor prognosis. Understanding the molecular mechanisms involved in tumor development and progression is strategic for the improvement of pharmacological therapies. Notch was recently proposed as a pharmacological target for the therapy of several cancers and is emerging as a new neuroblastoma-related molecular pathway. However, the precise role played by Notch in this cancer remains to be studied extensively. Here, we show that Notch activation by the Jagged1 ligand enhances the proliferation of neuroblastoma cells, and we propose the possible use of Notch-blocking γ-secretase inhibitors (GSIs) in neuroblastoma therapy. Two different GSIs, Compound E and DAPT, were tested alone or in combination with 13-cis retinoic acid (RA) on neuroblastoma cell lines. SH-SY5Y and IMR-32 cells were chosen as paradigms of lower and higher malignancy, respectively. Used alone, GSIs induced complete cell growth arrest, promoted neuronal differentiation, and significantly reduced cell motility. The combination of GSIs and 13-cis RA resulted in the enhanced growth inhibition, differentiation, and migration of neuroblastoma cells. In summary, our data suggest that a combination of GSIs with 13-cis RA offers a therapeutic advantage over a single agent, indicating a potential novel therapy for neuroblastoma.

  16. The Ubiquitin Ligase Praja1 Reduces NRAGE Expression and Inhibits Neuronal Differentiation of PC12 Cells

    PubMed Central

    Teuber, Jan; Mueller, Bettina; Fukabori, Ryoji; Lang, Daniel; Albrecht, Anne; Stork, Oliver

    2013-01-01

    Evidence suggests that regulated ubiquitination of proteins plays a critical role in the development and plasticity of the central nervous system. We have previously identified the ubiquitin ligase Praja1 as a gene product induced during fear memory consolidation. However, the neuronal function of this enzyme still needs to be clarified. Here, we investigate its involvement in the nerve growth factor (NGF)-induced differentiation of rat pheochromocytoma (PC12) cells. Praja1 co-localizes with cytoskeleton components and the neurotrophin receptor interacting MAGE homologue (NRAGE). We observed an enhanced expression of Praja1 after 3 days of NGF treatment and a suppression of neurite formation upon Praja1 overexpression in stably transfected PC12 cell lines, which was associated with a proteasome-dependent reduction of NRAGE levels. Our data suggest that Praja1, through ubiquitination and degradation of NRAGE, inhibits neuronal differentiation. The two murine isoforms, Praja1.1 and Praja1.2, appear to be functionally homologous in this respect. PMID:23717400

  17. Differential modulation and demodulation of multi-frequency digital communications signals

    NASA Astrophysics Data System (ADS)

    Moose, Paul H.

    Multiple-frequency modulation (MFM) is a bandwidth-efficient digital communication signaling technique that may be used effectively in mobile satellite communications links. Algorithms for generating and demodulating differentially encoded multifrequency quadrature phase shift keyed (MFQPSK) signals using discrete Fourier transform (DFT) techniques are discussed. The theory and a prototype system for differentially encoding and decoding MFQPSK in the frequency domain are developed. By using long baud intervals and corresponding small spacing of the carrier tones, problems associated with channel fading are greatly relieved with respect to the previous method of differentially encoding the multiple carrier tones from baud to baud. An MFM system has been configured to transmit MFQPSK over a 4-kHz bandpass channel. Tone spacings, or baud rates, of 15, 30, 60, 120, and 240 Hz were tested. Output signal-to-noise ratios were estimated by computing sample means and variances of the real and imaginary parts of Xa. Experimental results are presented showing good agreement with the theory.

  18. α-1,6-Fucosyltransferase (FUT8) inhibits hemoglobin production during differentiation of murine and K562 human erythroleukemia cells.

    PubMed

    Sasaki, Hitoshi; Toda, Takanori; Furukawa, Toru; Mawatari, Yuki; Takaesu, Rika; Shimizu, Masashi; Wada, Ryohei; Kato, Dai; Utsugi, Takahiko; Ohtsu, Masaya; Murakami, Yasufumi

    2013-06-07

    Erythropoiesis results from a complex combination of the expression of several transcription factor genes and cytokine signaling. However, the overall view of erythroid differentiation remains unclear. First, we screened for erythroid differentiation-related genes by comparing the expression profiles of high differentiation-inducible and low differentiation-inducible murine erythroleukemia cells. We identified that overexpression of α-1,6-fucosyltransferase (Fut8) inhibits hemoglobin production. FUT8 catalyzes the transfer of a fucose residue to N-linked oligosaccharides on glycoproteins via an α-1,6 linkage, leading to core fucosylation in mammals. Expression of Fut8 was down-regulated during chemically induced differentiation of murine erythroleukemia cells. Additionally, expression of Fut8 was positively regulated by c-Myc and c-Myb, which are known as suppressors of erythroid differentiation. Second, we found that FUT8 is the only fucosyltransferase family member that inhibits hemoglobin production. Functional analysis of FUT8 revealed that the donor substrate-binding domain and a flexible loop play essential roles in inhibition of hemoglobin production. This result clearly demonstrates that core fucosylation inhibits hemoglobin production. Third, FUT8 also inhibited hemoglobin production of human erythroleukemia K562 cells. Finally, a short hairpin RNA study showed that FUT8 down-regulation induced hemoglobin production and increase of transferrin receptor/glycophorin A-positive cells in human erythroleukemia K562 cells. Our findings define FUT8 as a novel factor for hemoglobin production and demonstrate that core fucosylation plays an important role in erythroid differentiation.

  19. Cell-Specific Fine-Tuning of Neuronal Excitability by Differential Expression of Modulator Protein Isoforms

    PubMed Central

    Jepson, James; Sheldon, Amanda; Shahidullah, Mohammad; Fei, Hong; Koh, Kyunghee

    2013-01-01

    SLOB (SLOWPOKE-binding protein) modulates the Drosophila SLOWPOKE calcium-activated potassium channel. We have shown previously that SLOB deletion or RNAi knockdown decreases excitability of neurosecretory pars intercerebralis (PI) neurons in the adult Drosophila brain. In contrast, we found that SLOB deletion/knockdown enhances neurotransmitter release from motor neurons at the fly larval neuromuscular junction, suggesting an increase in excitability. Because two prominent SLOB isoforms, SLOB57 and SLOB71, modulate SLOWPOKE channels in opposite directions in vitro, we investigated whether divergent expression patterns of these two isoforms might underlie the differential modulation of excitability in PI and motor neurons. By performing detailed in vitro and in vivo analysis, we found strikingly different modes of regulatory control by the slob57 and slob71 promoters. The slob71, but not slob57, promoter contains binding sites for the Hunchback and Mirror transcriptional repressors. Furthermore, several core promoter elements that are absent in the slob57 promoter coordinately drive robust expression of a luciferase vector by the slob71 promoter in vitro. In addition, we visualized the expression patterns of the slob57 and slob71 promoters in vivo and found clear spatiotemporal differences in promoter activity. SLOB57 is expressed prominently in adult PI neurons, whereas larval motor neurons exclusively express SLOB71. In contrast, at the larval neuromuscular junction, SLOB57 expression appears to be restricted mainly to a subset of glial cells. Our results illustrate how the use of alternative transcriptional start sites within an ion channel modulator locus coupled with functionally relevant alternative splicing can be used to fine-tune neuronal excitability in a cell-specific manner. PMID:24133277

  20. 14-3-3σ regulates keratinocyte proliferation and differentiation by modulating Yap1 cellular localization

    PubMed Central

    Sambandam, Sumitha A.T.; Kasetti, Ramesh Babu; Xue, Lei; Dean, Douglas C.; Lu, Qingxian; Li, Qiutang

    2015-01-01

    The homozygous repeated epilation (Er/Er) mouse mutant of the gene encoding 14-3-3σ displays an epidermal phenotype characterized by hyperproliferative keratinocytes and undifferentiated epidermis. Heterozygous Er/+ mice develop spontaneous skin tumors and are highly sensitive to tumor-promoting DMBA/TPA induction. The molecular mechanisms underlying 14-3-3σ regulation of epidermal proliferation, differentiation, and tumor formation have not been well elucidated. In the present study, we found that Er/Er keratinocytes failed to sequester Yap1 in the cytoplasm, leading to its nuclear localization during epidermal development in vivo and under differentiation-inducing culture conditions in vitro. In addition, enhanced Yap1 nuclear localization was also evident in DMBA/TPA-induced tumors from Er/+ skin. Furthermore, shRNA knockdown of Yap1 expression in Er/Er keratinocytes inhibited their proliferation, suggesting that YAP1 functions as a downstream effector of 14-3-3σ controlling epidermal proliferation. We then demonstrated that keratinocytes express all seven 14-3-3 protein isoforms, some of which form heterodimers with 14-3-3σ, either full-length WT or the mutant form found in Er/Er mice. However Er 14-3-3σ does not interact with Yap1, as demonstrated by co-immunoprecipitation. We conclude that Er 14-3-3σ disrupts the interaction between 14-3-3 and Yap1, thus fails to block Yap1 nuclear transcriptional function, causing continued progenitor expansion and inhibition of differentiation in Er/Er epidermis. PMID:25668240

  1. Poly(C)-binding protein 1 (Pcbp1) regulates skeletal muscle differentiation by modulating microRNA processing in myoblasts.

    PubMed

    Espinoza-Lewis, Ramon A; Yang, Qiumei; Liu, Jianming; Huang, Zhan-Peng; Hu, Xiaoyun; Chen, Daiwen; Wang, Da-Zhi

    2017-04-05

    Control of muscle cell proliferation and differentiation is essential to proper muscle development, function, and regeneration, and numerous transcriptional and post-transcriptional regulators are key to these processes. For example, recent studies have linked microRNAs (miRNAs) to muscle gene expression, development, and disease. The poly(C)-binding protein1 (Pcbp1, hnRNP-E1, or αCP-1) has been reported to bind the 3'UTRs of target genes to regulate mRNA stability and protein translation. However, Pcbp1's biological function in skeletal muscle and general mechanism of action remain largely undetermined. Here, we report that Pcbp1 is a component of the miRNA-processing pathway that regulates miRNA biogenesis. SiRNA-based inhibition of Pcbp1 transcript levels in mouse skeletal muscle myoblasts led to dysregulated cellular proliferation and differentiation. We also found that Pcbp1 null mutant mice exhibit early embryonic lethality, indicating that Pcbp1 is indispensable for embryonic development. Interestingly, hypomorphic Pcbp1 mutant mice displayed defects in muscle growth, a slow- to fast- myofibril switch and in the proliferation of myoblasts and muscle satellite cells. Moreover, Pcbp1 modulated the processing of muscle-enriched miR-1, miR-133, and miR-206 by physically interacting with Argonaute 2 (AGO2) and other miRNA pathway components. Our results therefore link the function of Pcbp1 to the miRNA pathway in skeletal muscle in mice. Future studies could help determine whether human Pbcp1 is involved in disorders such as muscular dystrophy or muscle degeneration.

  2. The Active Form of Vitamin D Transcriptionally Represses Smad7 Signaling and Activates Extracellular Signal-regulated Kinase (ERK) to Inhibit the Differentiation of a Inflammatory T Helper Cell Subset and Suppress Experimental Autoimmune Encephalomyelitis.

    PubMed

    Nanduri, Ravikanth; Mahajan, Sahil; Bhagyaraj, Ella; Sethi, Kanupriya; Kalra, Rashi; Chandra, Vemika; Gupta, Pawan

    2015-05-08

    The ability of the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), to transcriptionally modulate Smads to inhibit Th17 differentiation and experimental autoimmune encephalomyelitis (EAE) has not been adequately studied. This study reports modulation of Smad signaling by the specific binding of the VDR along with its heterodimeric partner RXR to the negative vitamin D response element on the promoter of Smad7, which leads to Smad7 gene repression. The vitamin D receptor-mediated increase in Smad3 expression partially explains the IL10 augmentation seen in Th17 cells. Furthermore, the VDR axis also modulates non-Smad signaling by activating ERK during differentiation of Th17 cells, which inhibits the Th17-specific genes il17a, il17f, il22, and il23r. In vivo EAE experiments revealed that, 1,25(OH)2D3 suppression of EAE correlates with the Smad7 expression in the spleen and lymph nodes. Furthermore, Smad7 expression also correlates well with IL17 and IFNγ expression in CNS infiltered inflammatory T cells. We also observed similar gene repression of Smad7 in in vitro differentiated Th1 cells when cultured in presence of 1,25(OH)2D3. The above canonical and non-canonical pathways in part address the ability of 1,25(OH)2D3-VDR to inhibit EAE.

  3. Capsaicin inhibits the adipogenic differentiation of bone marrow mesenchymal stem cells by regulating cell proliferation, apoptosis, oxidative and nitrosative stress.

    PubMed

    Ibrahim, Muhammed; Jang, Mi; Park, Mina; Gobianand, Kuppannan; You, Seungkwon; Yeon, Sung-Heom; Park, Sungkwon; Kim, Min Ji; Lee, Hyun-Jeong

    2015-07-01

    Obesity is a global health problem that requires the utmost attention. Apart from other factors the trans-differentiation of mesenchymal stem cells (MSCs) into adipocytes is an added detrimental factor causing the intensification of obesity. The main objective of this present study is to analyse whether capsaicin is capable of inhibiting the differentiation of BMSCs to adipocytes. Bone marrow mesenchymal stem cells (BMSCs) were obtained and exposed to different concentrations of capsaicin for a period of 6 days following 2 days of adipogenic induction. The capsaicin exposed cells were collected at three different time points (2, 4 and 6 days) and subjected to various analyses. BMSCs after exposure to capsaicin showed dose and time dependent reduction in cell viability and proliferation. Interestingly, capsaicin induced cell cycle arrest at G0-G1 and increased apoptosis by increasing reactive oxygen species (ROS) and reactive nitrogen species (RNS) production. Capsaicin significantly inhibited the early adipogenic differentiation, lipogenesis and maturation of adipocytes with concomitant repression of PPARγ, C/EBPα, FABP4 and SCD-1. Taken together, the results of the present study have clearly emphasized that capsaicin potentially inhibits the adipogenic differentiation of mesenchymal stem cells via many different pathways (anti-proliferative, apoptotic and cell cycle arrest) through the stimulation of ROS and RNS production. Thus, capsaicin not only suppresses the maturation of pre-adipocytes into adipocytes but also inhibits the differentiation of mesenchymal stem cells into adipocytes.

  4. Inhibition of preadipocyte differentiation and lipid accumulation by Orengedokuto treatment of 3T3-L1 cultures.

    PubMed

    Ikarashi, Nobutomo; Tajima, Masataka; Suzuki, Kunihiro; Toda, Takahiro; Ito, Kiyomi; Ochiai, Wataru; Sugiyama, Kiyoshi

    2012-01-01

    Obesity is a major cause of metabolic syndrome and is due to an increase in the number and hypertrophy of adipocytes. Accordingly, inhibition of the differentiation and proliferation of adipocytes may be used in the treatment and prevention of metabolic syndrome. This study investigated the effects of 50 commonly used Kampo medicines on the differentiation of 3T3-L1 preadipocytes to search for a drug with an antiobesity effect. Kampo medicines were screened, and the strongest differentiation-inhibitory effect was noted with Orengedokuto. To explore the active ingredients in Orengedokuto, the effects of four crude drug components of Orengedokuto were investigated. It was found that the differentiation-inhibitory effect of Orengedokuto was accounted for by Coptidis rhizome and Phellodendri cortex. Furthermore, berberine, a principal ingredient common to Coptidis rhizome and Phellodendri cortex, showed a differentiation-inhibitory effect. The effect of berberine involves an inhibition of the mRNA and protein expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α (C/EBPα). Moreover, berberine inhibited lipid accumulation in adipocytes. These findings suggest that an antiobesity effect could be a new indication for Orengedokuto and that its active ingredient is berberine, with a mechanism involving the inhibition of PPARγ and C/EBPα expression.

  5. Differentiation characteristics of human neuroblastoma cells in the presence of growth modulators and antimitotic drugs.

    PubMed

    Gupta, M; Notter, M F; Felten, S; Gash, D M

    1985-03-01

    Morphological characteristics of undifferentiated and differentiated human neuroblastoma cells were studied. Monolayer cultures of a human neuroblastoma, IMR-32 clone, were grown in Eagle's minimum essential medium with fetal calf serum in tissue culture dishes with polystyrene film liners. After 48 h, cultures were treated with either mitomycin C and 5-bromodeoxyuridine or prostaglandin E1 (PGE1) and dibutyryl adenosine 3',5'-cyclophosphate (cAMP). A third dish was untreated to study as an undifferentiated control. Three days later, all cultures were processed for acetylcholinesterase staining, scanning and transmission electron microscopy and high performance liquid chromatography. Treatment with mitomycin/5-bromodeoxyuridine and PGE1/cAMP inhibited growth as seen by the growth curves and caused morphological differentiation as seen by the extension of long neurites. The treated cells showed increased acetylcholinesterase staining compared to the controls. With the scanning electron microscope, the differentiated cells showed long neurites, processes with beaded varicosities and growth cones. By transmission electron microscopy, these cells contained a large number of neurosecretory granules in their cytoplasm and neurites. Specialized cell contacts were also observed between the treated cells. This is the first study demonstrating that both the treated and control cells of IMR-32 clone contain large quantities of serotonin and comparatively small amounts of norepinephrine and dopamine.

  6. miRNA-132-3p inhibits osteoblast differentiation by targeting Ep300 in simulated microgravity

    PubMed Central

    Hu, Zebing; Wang, Yixuan; Sun, Zhongyang; Wang, Han; Zhou, Hua; Zhang, Lianchang; Zhang, Shu; Cao, Xinsheng

    2015-01-01

    Recent studies have demonstrated that miRNAs can play important roles in osteoblast differentiation and bone formation. However, the function of miRNAs in bone loss induced by microgravity remains unclear. In this study, we investigated the differentially expressed miRNAs in both the femur tissues of hindlimb unloading rats and primary rat osteoblasts (prOB) exposed to simulated microgravity. Specifically, miR-132-3p was found up-regulated and negatively correlated with osteoblast differentiation. Overexpression of miR-132-3p significantly inhibited prOB differentiation, whereas inhibition of miR-132-3p function yielded an opposite effect. Furthermore, silencing of miR-132-3p expression effectively attenuated the negative effects of simulated microgravity on prOB differentiation. Further experiments confirmed that E1A binding protein p300 (Ep300), a type of histone acetyltransferase important for Runx2 activity and stability, was a direct target of miR-132-3p. Up-regulation of miR-132-3p by simulated microgravity could inhibit osteoblast differentiation in part by decreasing Ep300 protein expression, which, in turn, resulted in suppression of the activity and acetylation of Runx2, a key regulatory factor of osteoblast differentiation. Taken together, our findings are the first to demonstrate that miR-132-3p can inhibit osteoblast differentiation and participate in the regulation of bone loss induced by simulated microgravity, suggesting a potential target for counteracting decreases in bone formation. PMID:26686902

  7. Radicicol, a heat shock protein 90 inhibitor, inhibits differentiation and adipogenesis in 3T3-L1 preadipocytes

    SciTech Connect

    He, Yonghan; Li, Ying; Zhang, Shuocheng; Perry, Ben; Zhao, Tiantian; Wang, Yanwen; Sun, Changhao

    2013-06-28

    Highlights: •Radicicol suppressed intracellular fat accumulation in 3T3-L1 adipocytes. •Radicicol inhibited the expression of FAS and FABP4. •Radicicol blocked cell cycle at the G1-S phase during cell differentiation. •Radicicol inhibited the PDK1/Akt pathway in adipocyte differentiation. -- Abstract: Heat shock protein 90 (Hsp90) is involved in various cellular processes, such as cell proliferation, differentiation and apoptosis. As adipocyte differentiation plays a critical role in obesity development, the present study investigated the effect of an Hsp90 inhibitor radicicol on the differentiation of 3T3-L1 preadipocytes and potential mechanisms. The cells were treated with different concentrations of radicicol during the first 8 days of cell differentiation. Adipogenesis, the expression of adipogenic transcriptional factors, differentiation makers and cell cycle were determined. It was found that radicicol dose-dependently decreased intracellular fat accumulation through down-regulating the expression of peroxisome proliferator-activated receptor γ (PPAR{sub γ}) and CCAAT element binding protein α (C/EBP{sub α}), fatty acid synthase (FAS) and fatty acid-binding protein 4 (FABP4). Flow cytometry analysis revealed that radicicol blocked cell cycle at G1-S phase. Radicicol redcued the phosphorylation of Akt while showing no effect on β-catenin expression. Radicicol decreased the phosphorylation of phosphoinositide-dependent kinase 1 (PDK1). The results suggest that radicicol inhibited 3T3-L1 preadipocyte differentiation through affecting the PDK1/Akt pathway and subsequent inhibition of mitotic clonal expansion and the expression/activity of adipogenic transcriptional factors and their downstream adipogenic proteins.

  8. Copper Inhibits NMDA Receptor-Independent LTP and Modulates the Paired-Pulse Ratio after LTP in Mouse Hippocampal Slices

    PubMed Central

    Salazar-Weber, Nina L.; Smith, Jeffrey P.

    2011-01-01

    Copper misregulation has been implicated in the pathological processes underlying deterioration of learning and memory in Alzheimer's disease and other neurodegenerative disorders. Supporting this, inhibition of long-term potentiation (LTP) by copper (II) has been well established, but the exact mechanism is poorly characterized. It is thought that an interaction between copper and postsynaptic NMDA receptors is a major part of the mechanism; however, in this study, we found that copper (II) inhibited NMDA receptor-independent LTP in the CA3 region of hippocampal slices. In addition, in the CA3 and CA1 regions, copper modulated the paired-pulse ratio (PPR) in an LTP-dependent manner. Combined, this suggests the involvement of a presynaptic mechanism in the modulation of synaptic plasticity by copper. Inhibition of the copper-dependent changes in the PPR with cyclothiazide suggested that this may involve an interaction with the presynaptic AMPA receptors that regulate neurotransmitter release. PMID:22028985

  9. Striatal-enriched protein tyrosine phosphatase modulates nociception: evidence from genetic deletion and pharmacological inhibition

    PubMed Central

    Azkona, Garikoitz; Saavedra, Ana; Aira, Zigor; Aluja, David; Xifró, Xavier; Baguley, Tyler; Alberch, Jordi; Ellman, Jonathan A.; Lombroso, Paul J.; Azkue, Jon J.; Pérez-Navarro, Esther

    2016-01-01

    The information from nociceptors is processed in the dorsal horn of the spinal cord by complex circuits involving excitatory and inhibitory interneurons. It is well documented that GluN2B and ERK1/2 phosphorylation contributes to central sensitization. Striatal-enriched protein tyrosine phosphatase (STEP) dephosphorylates GluN2B and ERK1/2, promoting internalization of GluN2B and inactivation of ERK1/2. The activity of STEP was modulated by genetic (STEP knockout mice) and pharmacological (recently synthesized STEP inhibitor, TC-2153) approaches. STEP61 protein levels in the lumbar spinal cord were determined in male and female mice of different ages. Inflammatory pain was induced by complete Freund’s adjuvant injection. Behavioral tests, immunoblotting, and electrophysiology were used to analyze the effect of STEP on nociception. Our results show that both genetic deletion and pharmacological inhibition of STEP induced thermal hyperalgesia and mechanical allodynia, which were accompanied by increased pGluN2BTyr1472 and pERK1/2Thr202/Tyr204 levels in the lumbar spinal cord. Striatal-enriched protein tyrosine phosphatase heterozygous and knockout mice presented a similar phenotype. Furthermore, electrophysiological experiments showed that TC-2153 increased C fiber-evoked spinal field potentials. Interestingly, we found that STEP61 protein levels in the lumbar spinal cord inversely correlated with thermal hyperalgesia associated with age and female gender in mice. Consistently, STEP knockout mice failed to show age-related thermal hyperalgesia, although gender-related differences were preserved. Moreover, in a model of inflammatory pain, hyperalgesia was associated with increased phosphorylation-mediated STEP61 inactivation and increased pGluN2BTyr1472 and pERK1/2Thr202/Tyr204 levels in the lumbar spinal cord. Collectively, the present results underscore an important role of spinal STEP activity in the modulation of nociception. PMID:26270590

  10. Met/HGF receptor modulates bcl-w expression and inhibits apoptosis in human colorectal cancers

    PubMed Central

    Kitamura, S; Kondo, S; Shinomura, Y; Kanayama, S; Miyazaki, Y; Kiyohara, T; Hiraoka, S; Matsuzawa, Y

    2000-01-01

    The met proto-oncogene is the tyrosine kinase growth factor receptor for hepatocyte growth factor. In the present study, we investigated the role of met expression on the modulation of apoptosis in colorectal tumours. The gene expressions of c- met and the anti-apoptotic bcl -2 family, including bcl -2, bcl -x L and bcl-w, were analysed in human colorectal adenomas and adenocarcinomas by using a quantitative polymerase chain-reaction combined with reverse transcription. In seven of 12 adenomas and seven of 11 carcinomas, the c- met gene was overexpressed. The bcl -w, bcl -2 and bcl -x L genes were over-expressed in nine, five and six of 12 adenomas and in five, two and seven of 11 carcinomas, respectively. The c- met mRNA level in human colorectal adenomas and carcinomas was correlated with bcl -w but not with bcl -2 or with bcl -x L mRNA level. The administration of c- met -antisense oligonucleotides decreased Met protein levels in the LoVo human colon cancer cell line. In the case of c- met -antisense-treated cells, apoptotic cell death induced by serum deprivation was more prominent, compared to control or c- met -nonsense-treated cells. Treatment with c- met -antisense oligonucleotides inhibits the gene expression of bcl -w in LoVo cells. On the other hand, the gene expression of bcl -2 or bcl -x L was not affected by treatment with c- met -antisense oligonucleotides. These findings suggest that Met expression modulates apoptosis through bcl -w expression in colorectal tumours. © 2000 Cancer Research Campaign PMID:10944610

  11. Striatal-enriched protein tyrosine phosphatase modulates nociception: evidence from genetic deletion and pharmacological inhibition.

    PubMed

    Azkona, Garikoitz; Saavedra, Ana; Aira, Zigor; Aluja, David; Xifró, Xavier; Baguley, Tyler; Alberch, Jordi; Ellman, Jonathan A; Lombroso, Paul J; Azkue, Jon J; Pérez-Navarro, Esther

    2016-02-01

    The information from nociceptors is processed in the dorsal horn of the spinal cord by complex circuits involving excitatory and inhibitory interneurons. It is well documented that GluN2B and ERK1/2 phosphorylation contributes to central sensitization. Striatal-enriched protein tyrosine phosphatase (STEP) dephosphorylates GluN2B and ERK1/2, promoting internalization of GluN2B and inactivation of ERK1/2. The activity of STEP was modulated by genetic (STEP knockout mice) and pharmacological (recently synthesized STEP inhibitor, TC-2153) approaches. STEP(61) protein levels in the lumbar spinal cord were determined in male and female mice of different ages. Inflammatory pain was induced by complete Freund's adjuvant injection. Behavioral tests, immunoblotting, and electrophysiology were used to analyze the effect of STEP on nociception. Our results show that both genetic deletion and pharmacological inhibition of STEP induced thermal hyperalgesia and mechanical allodynia, which were accompanied by increased pGluN2B(Tyr1472) and pERK1/2(Thr202/Tyr204)levels in the lumbar spinal cord. Striatal-enriched protein tyrosine phosphatase heterozygous and knockout mice presented a similar phenotype. Furthermore, electrophysiological experiments showed that TC-2153 increased C fiber-evoked spinal field potentials. Interestingly, we found that STEP(61) protein levels in the lumbar spinal cord inversely correlated with thermal hyperalgesia associated with age and female gender in mice. Consistently, STEP knockout mice failed to show age-related thermal hyperalgesia, although gender-related differences were preserved. Moreover, in a model of inflammatory pain, hyperalgesia was associated with increased phosphorylation-mediated STEP(61) inactivation and increased pGluN2B(Tyr1472) and pERK1/2(Thr202/Tyr204)levels in the lumbar spinal cord. Collectively, the present results underscore an important role of spinal STEP activity in the modulation of nociception.

  12. Orexin A induces bidirectional modulation of synaptic plasticity: Inhibiting long-term potentiation and preventing depotentiation.

    PubMed

    Lu, Guan-Ling; Lee, Chia-Hsu; Chiou, Lih-Chu

    2016-08-01

    The orexin system consists of two peptides, orexin A and B and two receptors, OX1R and OX2R. It is implicated in learning and memory regulation while controversy remains on its role in modulating hippocampal synaptic plasticity in vivo and in vitro. Here, we investigated effects of orexin A on two forms of synaptic plasticity, long-term potentiation (LTP) and depotentiation of field excitatory postsynaptic potentials (fEPSPs), at the Schaffer Collateral-CA1 synapse of mouse hippocampal slices. Orexin A (≧30 nM) attenuated LTP induced by theta burst stimulation (TBS) in a manner antagonized by an OX1R (SB-334867), but not OX2R (EMPA), antagonist. Conversely, at 1 pM, co-application of orexin A prevented the induction of depotentiation induced by low frequency stimulation (LFS), i.e. restoring LTP. This re-potentiation effect of sub-nanomolar orexin A occurred at LFS of 1 Hz, but not 2 Hz, and with LTP induced by either TBS or tetanic stimulation. It was significantly antagonized by SB-334867, EMPA and TCS-1102, selective OX1R, OX2R and dual OXR antagonists, respectively, and prevented by D609, SQ22536 and H89, inhibitors of phospholipase C (PLC), adenylyl cyclase (AC) and protein kinase A (PKA), respectively. LFS-induced depotentiation was antagonized by blockers of NMDA, A1-adenosine and type 1/5 metabotropic glutamate (mGlu1/5) receptors, respectively. However, orexin A (1 pM) did not affect chemical-induced depotentiation by agonists of these receptors. These results suggest that orexin A bidirectionally modulates hippocampal CA1 synaptic plasticity, inhibiting LTP via OX1Rs at moderate concentrations while inducing re-potentiation via OX1Rs and OX2Rs, possibly through PLC and AC-PKA signaling at sub-nanomolar concentrations.

  13. Modulators of estrogen receptor inhibit proliferation and migration of prostate cancer cells.

    PubMed

    Piccolella, Margherita; Crippa, Valeria; Messi, Elio; Tetel, Marc J; Poletti, Angelo

    2014-01-01

    In the initial stages, human prostate cancer (PC) is an androgen-sensitive disease, which can be pharmacologically controlled by androgen blockade. This therapy often induces selection of androgen-independent PC cells with increased invasiveness. We recently demonstrated, both in cells and mice, that a testosterone metabolite locally synthetized in prostate, the 5α-androstane-3β, 17β-diol (3β-Adiol), inhibits PC cell proliferation, migration and invasion, acting as an anti-proliferative/anti-metastatic agent. 3β-Adiol is unable to bind androgen receptor (AR), but exerts its protection against PC by specifically interacting with estrogen receptor beta (ERβ). Because of its potential retro-conversion to androgenic steroids, 3β-Adiol cannot be used "in vivo", thus, the aims of this study were to investigate the capability of four ligands of ERβ (raloxifen, tamoxifen, genistein and curcumin) to counteract PC progression by mimicking the 3β-Adiol activity. Our results demonstrated that raloxifen, tamoxifen, genistein and curcumin decreased DU145 and PC3 cell proliferation in a dose-dependent manner; in addition, all four compounds significantly decreased the detachment of cells seeded on laminin or fibronectin. Moreover, raloxifen, tamoxifen, genistein and curcumin-treated DU145 and PC3 cells showed a significant decrease in cell migration. Notably, all these effects were reversed by the anti-estrogen, ICI 182,780, suggesting that their actions are mediated by the estrogenic pathway, via the ERβ, the only isoform present in these PCs. In conclusion, these data demonstrate that by selectively activating the ERβ, raloxifen, tamoxifen, genistein and curcumin inhibit human PC cells proliferation and migration favoring cell adesion. These synthetic and natural modulators of ER action may exert a potent protective activity against the progression of PC even in its androgen-independent status.

  14. Pain facilitation and pain inhibition during conditioned pain modulation in fibromyalgia and in healthy controls.

    PubMed

    Potvin, Stéphane; Marchand, Serge

    2016-08-01

    Although fibromyalgia (FM) is associated with a deficit in inhibitory conditioned pain modulation (CPM), the discriminative power of CPM procedures is unknown. Moreover, the high intersubject heterogeneity in CPM responses in FM raises the possibility that a sizeable subgroup of these patients may experience pain facilitation during CPM, but the phenomenon has not been explicitly studied. To address these issues, 96 patients with FM and 71 healthy controls were recruited. Thermal stimuli were used to measure pain thresholds. Pain inhibition was elicited using a tonic thermal test (Peltier thermode) administered before and after activation of CPM mechanisms using a cold pressor test. Thermal pain thresholds were lower in patients with FM than in healthy controls. Pain ratings during the cold pressor test were higher in patients with FM, relative to controls. The CPM inhibitory efficacy was lower in patients with FM than in controls. The CPM procedure had good specificity (78.9%) but low sensitivity (45.7%), whereas a composite pain index had good sensitivity (75.0%) and specificity (78.9%). Finally, the rate of patients with FM who reported pain facilitation during the CPM procedure was found to be significantly increased compared with that of controls (41.7% vs 21.2%). The good discriminative power of the composite pain index highlights the need for further validation studies using mechanistically relevant psychophysical procedures in FM. The low sensitivity of the CPM procedure, combined with the large proportion of patients with FM experiencing pain facilitation during CPM, strongly suggests that endogenous pain inhibition mechanisms are deeply impaired in patients with FM, but only in a subgroup of them.

  15. Arogenate dehydratase isoenzymes profoundly and differentially modulate carbon flux into lignins.

    PubMed

    Corea, Oliver R A; Ki, Chanyoung; Cardenas, Claudia L; Kim, Sung-Jin; Brewer, Sarah E; Patten, Ann M; Davin, Laurence B; Lewis, Norman G

    2012-03-30

    How carbon flux differentially occurs in vascular plants following photosynthesis for protein formation, phenylpropanoid metabolism (i.e. lignins), and other metabolic processes is not well understood. Our previous discovery/deduction that a six-membered arogenate dehydratase (ADT1-6) gene family encodes the final step in Phe biosynthesis in Arabidopsis thaliana raised the fascinating question whether individual ADT isoenzymes (or combinations thereof) differentially modulated carbon flux to lignins, proteins, etc. If so, unlike all other lignin pathway manipulations that target cell wall/cytosolic processes, this would be the first example of a plastid (chloroplast)-associated metabolic process influencing cell wall formation. Homozygous T-DNA insertion lines were thus obtained for five of the six ADTs and used to generate double, triple, and quadruple knockouts (KOs) in different combinations. The various mutants so obtained gave phenotypes with profound but distinct reductions in lignin amounts, encompassing a range spanning from near wild type levels to reductions of up to ∼68%. In the various KOs, there were also marked changes in guaiacyl:syringyl ratios ranging from ∼3:1 to 1:1, respectively; these changes were attributed to differential carbon flux into vascular bundles versus that into fiber cells. Laser microscope dissection/pyrolysis GC/MS, histochemical staining/lignin analyses, and pADT::GUS localization indicated that ADT5 preferentially affects carbon flux into the vascular bundles, whereas the adt3456 knock-out additionally greatly reduced carbon flux into fiber cells. This plastid-localized metabolic step can thus profoundly differentially affect carbon flux into lignins in distinct anatomical regions and provides incisive new insight into different factors affecting guaiacyl:syringyl ratios and lignin primary structure.

  16. NLS-RARα promotes proliferation and inhibits differentiation in HL-60 cells.

    PubMed

    Hu, Xiu-Xiu; Zhong, Liang; Zhang, Xi; Gao, Yuan-Mei; Liu, Bei-Zhong

    2014-01-01

    A unique mRNA produced in leukemic cells from a t(15;17) acute promyelocytic leukemia (APL) patient encodes a fusion protein between the retinoic acid receptor α (RARα) and a myeloid gene product called PML. Studies have reported that neutrophil elastase (NE) cleaves bcr-1-derived PML-RARα in early myeloid cells, leaving only the nuclear localization signal (NLS) of PML attached to RARα. The resultant NLS-RARα fusion protein mainly localizes to, and functions within, the cell nucleus. It is speculated that NLS-RARα may act in different ways from the wild-type RARα, but its biological characteristics have not been reported. This study takes two approaches. Firstly, the NLS-RARα was silenced with pNLS-RARα-shRNA. The mRNA and protein expression of NLS-RARα were detected by RT-PCR and Western blot respectively. Cell proliferation in vitro was assessed by MTT assay. Flow cytometry (FCM) was used to detect the differentiation of cells. Secondly, the NLS-RARα was over-expressed by preparation of recombinant adenovirus HL-60/pAd-NLS-RARα. The assays of mRNA and protein expression of NLS-RARα, and cell proliferation, were as above. By contrast, cell differentiation was stimulated by all trans retinoic acid (ATRA) (2.5µmol/L) at 24h after virus infection of pAd-NLS-RARα, and then detected by CD11b labeling two days later. The transcription and translation of C-MYC was detected in HL-60/pAd-NLS-RARα cells which treated by ATRA. Our results showed that compared to the control groups, the expression of NLS-RARα was significantly reduced in the HL-60/pNLS-RARα-shRNA cells, and increased dramatically in the HL-60/pAd-NLS-RARα cells. The proliferation was remarkably inhibited in the HL-60/pNLS-RARα-shRNA cells in a time-dependent manner, but markedly promoted in the HL-60/pAd-NLS-RARα cells. FCM outcome revealed the differentiation increased in HL-60/pNLS-RARα-shRNA cells, and decreased in the HL-60/pAd-NLS-RARα cells treated with 2.5µmol/L ATRA. The

  17. Diet-derived polyphenols inhibit angiogenesis by modulating the interleukin-6/STAT3 pathway

    SciTech Connect

    Lamy, Sylvie; Akla, Naoufal; Ouanouki, Amira; Lord-Dufour, Simon; Beliveau, Richard

    2012-08-01

    Several epidemiological studies have indicated that abundant consumption of foods from plant origin is associated with a reduced risk of developing several types of cancers. This chemopreventive effect is related to the high content of these foods in phytochemicals, such as polyphenols, that interfere with several processes involved in cancer progression including tumor cell growth, survival and angiogenesis. In addition to the low intake of plant-based foods, increased body mass and physical inactivity have recently emerged as other important lifestyle factors influencing cancer risk, leading to the generation of low-grade chronic inflammatory conditions which are a key process involved in tumor progression. The objectives of the current study are to investigate the inhibitory effects of these polyphenols on angiogenesis triggered by an inflammatory cytokine (IL-6) and to determine the mechanisms underlying this action. We found that, among the tested polyphenols, apigenin and luteolin were the most potent angiogenesis inhibitors through their inhibitory effect on the inflammatory cytokine IL-6/STAT3 pathway. These effects resulted in modulation of the activation of extracellular signal-regulated kinase-1/2 signaling triggered by IL-6, as well as in a marked reduction in the proliferation, migration and morphogenic differentiation of endothelial cells. Interestingly, these polyphenols also modulated the expression of IL-6 signal transducing receptor (IL-6R{alpha}) and the secretion of the extracellular matrix degrading enzyme MMP-2 as well as the expression of suppressor of cytokine signaling (SOCS3) protein. Overall, these results may provide important new information on the role of diet in cancer prevention.

  18. Surfactant Protein A integrates activation signal strength to differentially modulate T cell proliferation

    PubMed Central

    Mukherjee, Sambuddho; Giamberardino, Charles; Thomas, Joseph; Evans, Kathy; Goto, Hisatsugu; Ledford, Julie G; Hsia, Bethany; Pastva, Amy M; Wright, Jo Rae

    2011-01-01

    Pulmonary surfactant lipoproteins lower the surface tension at the alveolar:airway interface of the lung and participate in host defense. Previous studies reported that surfactant protein A (SP-A) inhibits lymphocyte proliferation. We hypothesized that SP-A mediated modulation of T cell activation depends upon the strength, duration and type of lymphocyte activating signals. Modulation of T cell signal strength imparted by different activating agents ex and in vivo in different mouse models, and in vitro with human T cells show a strong correlation between strength of signal (SoS) and functional effects of SP-A interactions. T cell proliferation is enhanced in the presence of SP-A at low SoS imparted by exogenous mitogens, specific antibodies, APCs or in homeostatic proliferation. Proliferation is inhibited at higher SoS imparted by different doses of the same T cell mitogens, or indirect stimuli such as LPS. Importantly, reconstitution with exogenous SP-A into the lungs of SP-A-/- mice stimulated with a strong signal also resulted in suppression of T cell proliferation, while elevating baseline proliferation in unstimulated T cells. These signal strength and SP-A dependent effects are mediated by changes in intracellular Ca2+ levels over time, involving extrinsic Ca2+ activated channels late during activation. These effects are intrinsic to the global T cell population, and are manifested in vivo in naïve as well as memory phenotype T cells. Thus, SP-A appears to integrate signal thresholds to control T cell proliferation. PMID:22219327

  19. CD147 modulates the differentiation of T-helper 17 cells in patients with rheumatoid arthritis.

    PubMed

    Yang, Hui; Wang, Jian; Li, Yu; Yin, Zhen-Jie; Lv, Ting-Ting; Zhu, Ping; Zhang, Yan

    2017-01-01

    The role of CD147 in regulation of rheumatoid arthritis (RA) is not fully elucidated. The aim of this study was to investigate the effect of cell-to-cell contact of activated CD14(+) monocytes with CD4(+) T cells, and the modulatory role of CD147 on T-helper 17 (Th17) cells differentiation in patients with RA. Twenty confirmed active RA patients and twenty normal controls were enrolled. CD4(+) T cells and CD14(+) monocytes were purified by magnetic beads cell sorting. Cells were cultured under different conditions in CD4(+) T cells alone, direct cell-to-cell contact co-culture of CD4(+) and CD14(+) cells, or indirect transwell co-culture of CD4(+) /CD14(+) cells in response to LPS and anti-CD3 stimulation with or without anti-CD147 antibody pretreatments. The proportion of IL-17-producing CD4(+) T cells (defined as Th17 cells) was determined by flow cytometry. The levels of interleukin (IL)-17, IL-6, and IL-1β in the supernatants of cultured cells were measured by ELISA. The optimal condition for in vitro induction of Th17 cells differentiation was co-stimulation with 0.1 μg/mL of LPS and 100 ng/mL of anti-CD3 for 3 days under direct cell-to-cell contact co-culture of CD4(+) and CD14(+) cells. Anti-CD147 antibody reduced the proportion of Th17 cells, and also inhibited the productions of IL-17, IL-6, and IL-1β in PBMC culture from RA patients. The current results revealed that Th17 differentiation required cell-to-cell contact with activated monocytes. CD147 promoted the differentiation of Th17 cells by regulation of cytokine production, which provided the evidence for pathogenesis and potential therapeutic targets for RA.

  20. Corneal surface glycosylation is modulated by IL-1R and Pseudomonas aeruginosa challenge but is insufficient for inhibiting bacterial binding.

    PubMed

    Jolly, Amber L; Agarwal, Paresh; Metruccio, Matteo M E; Spiciarich, David R; Evans, David J; Bertozzi, Carolyn R; Fleiszig, Suzanne M J

    2017-02-21

    Cell surface glycosylation is thought to be involved in barrier function against microbes at mucosal surfaces. Previously we showed that the epithelium of healthy mouse corneas becomes vulnerable to P. aeruginosa adhesion if it lacks the innate defense protein MyD88 (myeloid differentiation primary response gene 88), or after superficial injury by blotting with tissue paper. Here we explored their effect on corneal surface glycosylation using a metabolic label, tetra-acetylated N-azidoacetylgalactosamine (Ac4GalNAz). Ac4GalNAz treatment labeled the surface of healthy mouse corneas, leaving most cells viable, and bacteria preferentially associated with GalNAz-labeled regions. Surprisingly, corneas from MyD88(-/-) mice displayed similar GalNAz labeling to wild-type corneas, but labeling was reduced and patchy on IL-1 receptor (IL-1R)-knockout mouse corneas (P < 0.05, ANOVA). Tissue paper blotting removed GalNAz-labeled surface cells, causing DAPI labeling (permeabilization) of underlying cells. MS of material collected on the tissue paper blots revealed 67 GalNAz-labeled proteins, including intracellular proteins. These data show that the normal distribution of surface glycosylation requires IL-1R, but not MyD88, and is not sufficient to prevent bacterial binding. They also suggest increased P. aeruginosa adhesion to MyD88(-/-) and blotted corneas is not due to reduction in total surface glycosylation, and for tissue paper blotting is likely due to cell permeabilization.-Jolly, A. L., Agarwal, P., Metruccio, M. M. E., Spiciarich, D. R., Evans, D. J., Bertozzi, C. R., Fleiszig, S. M. J. Corneal surface glycosylation is modulated by IL-1R and Pseudomonas aeruginosa challenge but is insufficient for inhibiting bacterial binding.

  1. Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings : Analysis of Growth, Sugar Accumulation, and Gene Expression.

    PubMed

    Creelman, R A; Mason, H S; Bensen, R J; Boyer, J S; Mullet, J E

    1990-01-01

    Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite.

  2. Study of Polymer Glasses by Modulated Differential Scanning Calorimetry in the Undergraduate Physical Chemistry Laboratory

    NASA Astrophysics Data System (ADS)

    Folmer, J. C. W.; Franzen, Stefan

    2003-07-01

    Recent technological advances in thermal analysis present educational opportunities. In particular, modulated differential scanning calorimetry (MDSC) can be used to contrast reversing and nonreversing processes in practical laboratory experiments. The introduction of these concepts elucidates the relationship between experimental timescales and reversibility. The latter is a key concept of undergraduate thermodynamics theory that deserves reinforcement. In this paper, the theory and application of MDSC to problems of current interest is outlined with special emphasis on the contrast between crystallization and vitrification. Glass formation deserves greater emphasis in the undergraduate curriculum. Glass transitions are increasingly recognized as an important aspect of materials properties and dynamics in fields ranging from polymer science to protein folding. The example chosen for study is a comparison of polyethylene glycol and atactic polypropylene glycol. The experiment is easily performed in a typical three-hour lab session.

  3. Differential Preparation Intervals Modulate Repetition Processes in Task Switching: An ERP Study

    PubMed Central

    Wang, Min; Yang, Ping; Zhao, Qian-Jing; Wang, Meng; Jin, Zhenlan; Li, Ling

    2016-01-01

    In task-switching paradigms, reaction times (RTs) switch cost (SC) and the neural correlates underlying the SC are affected by different preparation intervals. However, little is known about the effect of the preparation interval on the repetition processes in task-switching. To examine this effect we utilized a cued task-switching paradigm with long sequences of repeated trials. Response-stimulus intervals (RSI) and cue-stimulus intervals (CSI) were manipulated in short and long conditions. Electroencephalography (EEG) and behavioral data were recorded. We found that with increasing repetitions, RTs were faster in the short CSI conditions, while P3 amplitudes decreased in the LS (long RSI and short CSI) conditions. Positive correlations between RT benefit and P3 activation decrease (repeat 1 − repeat 5), and between the slope of the RT and P3 regression lines were observed only in the LS condition. Our findings suggest that differential preparation intervals modulate repetition processes in task switching. PMID:26924974

  4. The grapevine polygalacturonase-inhibiting protein (VvPGIP1) reduces Botrytis cinerea susceptibility in transgenic tobacco and differentially inhibits fungal polygalacturonases.

    PubMed

    Joubert, Dirk A; Slaughter, Ana R; Kemp, Gabré; Becker, John V W; Krooshof, Geja H; Bergmann, Carl; Benen, Jacques; Pretorius, Isak S; Vivier, Melané A

    2006-12-01

    Polygalacturonase-inhibiting proteins (PGIPs) selectively inhibit polygalacturonases (PGs) secreted by invading plant pathogenic fungi. PGIPs display differential inhibition towards PGs from different fungi, also towards different isoforms of PGs originating from a specific pathogen. Recently, a PGIP-encoding gene from Vitis vinifera (Vvpgip1) was isolated and characterised. PGIP purified from grapevine was shown to inhibit crude polygalacturonase extracts from Botrytis cinerea, but this inhibitory activity has not yet been linked conclusively to the activity of the Vvpgip1 gene product. Here we use a transgenic over-expression approach to show that the PGIP encoded by the Vvpgip1 gene is active against PGs of B. cinerea and that over-expression of this gene in transgenic tobacco confers a reduced susceptibility to infection by this pathogen. A calculated reduction in disease susceptibility of 47-69% was observed for a homogeneous group of transgenic lines that was statistically clearly separated from untransformed control plants following infection with Botrytis over a 15-day-period. VvPGIP1 was subsequently purified from transgenic tobacco and used to study the specific inhibition profile of individual PGs from Botrytis and Aspergillus. The heterologously expressed and purified VvPGIP1 selectively inhibited PGs from both A. niger and B. cinerea, including BcPG1, a PG from B. cinerea that has previously been shown to be essential for virulence and symptom development. Altogether our data confirm the antifungal nature of the VvPGIP1, and the in vitro inhibition data suggest at least in part, that the VvPGIP1 contributed to the observed reduction in disease symptoms by inhibiting the macerating action of certain Botrytis PGs in planta. The ability to correlate inhibition profiles to individual PGs provides a more comprehensive analysis of PGIPs as antifungal genes with biotechnological potential, and adds to our understanding of the importance of PGIP

  5. Type I and II positive allosteric modulators differentially modulate agonist-induced up-regulation of α7 nicotinic acetylcholine receptors.

    PubMed

    Thomsen, Morten