MH_dev_190

P01375 REA alpha mediates GABA ( A ) receptor trafficking to the plasma membrane of spinal cord neurons in vivo . The proinflammatory cytokine TNFα contributes to cell death in central nervous system ( CNS ) disorders by altering synaptic neurotransmission . TNFα contributes to excitotoxicity by increasing P42262 REA - lacking AMPA receptor ( AMPAR ) trafficking to the neuronal plasma membrane . In vitro , increased AMPAR on the neuronal surface after TNFα exposure is associated with a rapid internalization of GABA ( A ) receptors ( GABA ( A ) Rs ) , suggesting complex timing and dose dependency of the CNS ' s response to TNFα . However , the effect of TNFα on GABA ( A ) R trafficking in vivo remains unclear . We assessed the effect of TNFα nanoinjection on rapid GABA ( A ) R changes in rats ( N = 30 ) using subcellular fractionation , quantitative western blotting , and confocal microscopy . GABA ( A ) R protein levels in membrane fractions of TNFα and vehicle-treated subjects were not significantly different by Western Blot , yet high-resolution quantitative confocal imaging revealed that TNFα induces GABA ( A ) R trafficking to synapses in a dose-dependent manner by 60 min . TNFα-mediated GABA ( A ) R trafficking represents a novel target for CNS excitotoxicity .

Presence of a P34969 REA receptor positively coupled to adenylate cyclase activation in human granulosa-lutein cells . Although serotonin ( 5 - HT ) has been shown to stimulate progesterone production by human granulosa-lutein cells ( hGLC ) , the receptor type and associated signaling pathway remain uncharacterized . We report here that 5 - HT receptors in these cells are positively coupled to adenylate cyclase activity . Formation of DB02527 was stimulated by 5 - HT and its agonists in a dose - and time-dependent manner . DB06148 MEN , amoxapine , and loxapine were equipotent in antagonizing 5 - HT-induced DB02527 formation . For both DB02527 formation in cells and adenylate cyclase assay using membrane fractions , the rank order of potency for agonists of 5 - HT were : 5 - carboxy-aminotryptamine > 5 - HT > or = 5 - methoxytryptamine , consistent with a typical pharmacological profile of human 5 - ht7 ( h5 - ht7 ) receptor . Sequence data of amplified complementary DNA fragments reverse transcribed from hGLC RNA revealed complete identity with published sequence of h5 - ht7 receptor complementary DNA . Northern analysis showed the presence of 2.8- kb h5 - ht7 transcripts in hGLC . The three variants h5 - ht7A , h5 - ht7B , and h5 - ht7D were also detected in hGLC . Preincubation of hGLC with 5 - HT ( 10 (-8 ) - 10 ( - 6 ) M ) resulted in a marked reduction in the DB02527 response when the cells were subsequently stimulated with gonadotropin , and this heterologous desensitization could be reversed by 5 - ht7 receptor antagonist clozapine . These data demonstrate that h5 - ht7 receptor is present and stimulate DB02527 formation in hGLC . In addition , the h5 - ht7 receptor seems to be implicated in the heterologous down-regulation hCG-stimulated DB02527 response in hGLC , with a possible ramification for luteal insufficiency .

Inhibitory effects of a luteinizing hormone-releasing hormone agonist on basal and epidermal growth factor-induced cell proliferation and metastasis-associated properties in human epidermoid carcinoma A431 cells . The purpose of this study was to investigate the effects of a potent P01148 REA agonist , [ D - DB00150 ( 6 ) ] P01148 REA on the basal and P01133 REA - induced cell proliferation and the metastasis-associated properties in A431 human epidermoid carcinoma . [ D - DB00150 ( 6 ) ] P01148 REA time-dependently inhibited the basal and P01133 REA - stimulated growth of A431 cancer cells . It is assumed that phosphorylation / dephosphorylation of cellular proteins is highly related to cell growth . This study demonstrates that [ D - DB00150 ( 6 ) ] P01148 REA decreased the basal and P01133 REA - induced total cellular kinase activity , particularly the tyrosine phosphorylation of several cellular proteins including the P00533 REA . In contrast , [ D - DB00150 ( 6 ) ] P01148 REA did not cause detectable changes in basal and P01133 REA - stimulated serine / threonine phosphorylation of A431 cellular proteins . The inhibitory effect of [ D - DB00150 ( 6 ) ] P01148 REA on A431 cell proliferation was associated with apoptosis as evidenced by the cell morphology and DNA integrity ( ladder pattern ) , the expression of interleukin 1beta - converting enzyme ( ICE ) and activation of caspase . Furthermore , P01133 REA could rescue the remaining attached A431 cells following [ D - DB00150 ( 6 ) ] P01148 REA treatment for 48 hr , which suggests that limited exposure to [ D - DB00150 ( 6 ) ] P01148 REA did not channel all cells to irreversible apoptotic process . We also determined the effects of [ D - DB00150 ( 6 ) ] P01148 REA on metastasis-associated properties in A431 cells . [ D - DB00150 ( 6 ) ] P01148 REA reduced both basal and P01133 REA - stimulated secretion of P14780 REA and P08253 REA . In addition , [ D - DB00150 ( 6 ) ] P01148 REA suppressed the basal and P01133 REA - induced invasive activity of A431 cells based on an in vitro invasion assay . In conclusion , this study indicates that [ D - DB00150 ( 6 ) ] P01148 REA may act partly through activating tyrosine phosphatase activity to inhibit cell proliferation and the metastasis-associated properties of A431 cancer cells . Our work suggests that [ D - DB00150 ( 6 ) ] P01148 REA may be therapeutically useful in limiting the tumor growth and metastasis of some neoplasms .

Histone deacetylase inhibitor treatment dramatically reduces cholesterol accumulation in Niemann-Pick type C1 mutant human fibroblasts . Niemann-Pick type C ( NPC ) disease is predominantly caused by mutations in the O15118 REA protein that affect intracellular cholesterol trafficking and cause accumulation of unesterified cholesterol and other lipids in lysosomal storage organelles . We report the use of a series of small molecule histone deacetylase ( HDAC ) inhibitors in tissue culture models of NPC human fibroblasts . Some HDAC inhibitors lead to a dramatic correction in the NPC phenotype in cells with either one or two copies of the O15118 REA ( I1061T ) mutation , and for several of the inhibitors , correction is associated with increased expression of O15118 REA protein . Increased O15118 REA ( I1061T ) protein levels may partially account for the correction of the phenotype , because this mutant can promote cholesterol efflux if it is delivered to late endosomes and lysosomes . The HDAC inhibitor treatment is ineffective in an P61916 REA mutant human fibroblast line . Analysis of the isoform selectivity of the compounds used implicates Q13547 REA and / or Q92769 REA as likely targets for the observed correction , although other HDACs may also play a role . LBH 589 ( DB06603 MENMAX DB06603 MEN ) is an orally available HDAC inhibitor that crosses the blood-brain barrier and is currently in phase III clinical trials for several types of cancer . It restores cholesterol homeostasis in cultured O15118 REA mutant fibroblasts to almost normal levels within 72 h when used at 40 nM . The findings that HDAC inhibitors can correct cholesterol storage defects in human O15118 REA mutant cells provide the potential basis for treatment options for NPC disease .

Nanostructured lipid carriers as multifunctional nanomedicine platform for pulmonary co-delivery of anticancer drugs and siRNA . We developed , synthesized , and tested a multifunctional nanostructured lipid nanocarrier-based system ( NLCS ) for efficient delivery of an anticancer drug and siRNA directly into the lungs by inhalation . The system contains : ( 1 ) nanostructured lipid carriers ( NLC ) ; ( 2 ) anticancer drug ( doxorubicin or paclitaxel ) ; ( 3 ) siRNA targeted to MRP 1 mRNA as a suppressor of pump drug resistance ; ( 4 ) siRNA targeted to P10415 REA mRNA as a suppressor of nonpump cellular resistance and ( 5 ) a modified synthetic analog of luteinizing hormone-releasing hormone ( P01148 REA ) as a targeting moiety specific to the receptors that are overexpressed in the plasma membrane of lung cancer cells . The NLCS was tested in vitro using human lung cancer cells and in vivo utilizing mouse orthotopic model of human lung cancer . After inhalation , the proposed NLCS effectively delivered its payload into lung cancer cells leaving healthy lung tissues intact and also significantly decreasing the exposure of healthy organs when compared with intravenous injection . The NLCS showed enhanced antitumor activity when compared with intravenous treatment . The data obtained demonstrated high efficiency of proposed NLCS for tumor-targeted local delivery by inhalation of anticancer drugs and mixture of siRNAs specifically to lung cancer cells and , as a result , efficient suppression of tumor growth and prevention of adverse side effects on healthy organs .

Agents with selective estrogen receptor ( ER ) modulator activity induce apoptosis in vitro and in vivo in ER-negative glioma cells . Tamoxifen , a member of the selective estrogen receptor modulator ( SERM ) family , is widely used in the treatment of estrogen receptor ( ER ) - expressing breast cancer . It has previously been shown that high-dose tamoxifen has cytotoxic activity against glioma cells , but whether this effect is drug specific or represents a general property of SERMs is unknown . In this study , we demonstrate that tamoxifen and DB05487 MEN , a novel benzopyranone with SERM activity , induce glioma cell apoptosis in a dose - and time-dependent manner . Moreover , administration of tamoxifen and DB05487 MEN suppresses tumor growth in vivo and extends animal survival in glioma xenograft models . None of the eight glioma cell lines examined express either P03372 REA or - beta , suggesting the mechanism for tamoxifen - and DB05487 MEN - induced glioma cell apoptosis is independent of the ER signaling pathway . Complementary DNA microarray expression profiling allowed us to identify a subset of genes specifically regulated by tamoxifen and DB05487 MEN , and not by other apoptotic stimuli , including nuclear factor ( NF ) - kappaB with its target genes IEX - 3 , P04179 REA , P05231 REA , and P10145 REA . We demonstrate that suppression of NF-kappaB activation markedly enhances SERM-induced apoptosis , suggesting a role for NF-kappaB in protecting glioma cells from SERM-induced cytotoxicity . These findings demonstrate for the first time that a SERM other than tamoxifen can induce glioma cell apoptosis in vitro and in vivo and that the clinical efficacy of SERMs for the treatment of malignant gliomas could potentially be enhanced by simultaneous inhibition of the NF-kappaB pathway .

A conserved mechanism for gating in an ionotropic glutamate receptor . Ionotropic glutamate receptor ( iGluR ) channels control synaptic activity . The crystallographic structure of P42262 REA , the prototypical iGluR , reveals a clamshell-like ligand-binding domain ( LBD ) that closes in the presence of glutamate to open a gate on the pore lining α-helix . How LBD closure leads to gate opening remains unclear . Here , we show that bending the pore helix at a highly conserved alanine residue ( Ala - 621 ) below the gate is responsible for channel opening . Substituting Ala - 621 with the smaller more flexible glycine resulted in a basally active , nondesensitizing channel with ∼ 39 - fold increase in glutamate potency without affecting surface expression or binding . On P42262 REA ( A621G ) , the partial agonist kainate showed efficacy similar to a full agonist , and competitive antagonists CNQX and DB03759 MEN acted as a partial agonists . DB00134 - 629 in P42262 REA sits above the gate and is critical in transmitting LBD closure to the gate . Substituting DB00134 - 629 with the flexible glycine resulted in reduced channel activity and glutamate potency . The pore regions in potassium channels are structurally similar to iGluRs . Whereas potassium channels typically use glycines as a hinge for gating , iGluRs use the less flexible alanine as a hinge at a similar position to maintain low basal activity allowing for ligand-mediated gating .

DB00163 prevents ethanol-induced inflammatory , hormonal , and cytotoxic changes in reproductive tissues . DB00898 causes decreased function of the hypothalamic-pituitary-gonadal ( HPG ) axis . DB00898 resulted in inflammatory changes in HPG manifested by increased concentrations of pro-inflammatory cytokines . Since , such cytokines have deleterious effects on functions of HPG , it seemed possible that ethanol ' s suppressive action could be due , at least in part , to this inflammation . Since oxidative stress can cause inflammation , we have used the antioxidant vitamin E to test , whether reducing inflammation might protect reproductive functions from ethanol . Rats were fed an ethanol diet or pair fed identically without ethanol for a 3 - week period . For the last 10 days , animals were given 30 IU / kg or 90 IU / kg or vehicle . DB00898 significantly increased hypothalamic , pituitary and testicular P01375 REA and P05231 REA , all changes prevented by the higher dose of vitamin E . Also , ethanol induced changes in P01148 REA , LH , testosterone , and testicular germ cell apoptosis were similarly prevented by vitamin E . These data strikingly show that vitamin E protects the HPG from deleterious effects of ethanol and suggests that the mechanism of this protection might be both anti-inflammatory and antioxidant .

Serotonin directly stimulates luteinizing hormone-releasing hormone release from GT1 cells via P34969 REA receptors . DB00044 - releasing hormone ( P01148 REA release , which serves as the primary drive to the hypothalamic-pituitary gonadal axis , is controlled by many neuromediators . Serotonin has been implicated in this regulation . However , it is unclear whether the central effect of serotonin on P01148 REA secretion is exerted directly on P01148 REA neurosecretory neurons or indirectly via multisynaptic pathways . The present studies were undertaken in order to examine whether P01148 REA secretion from immortalized P01148 REA cell lines is directly regulated by serotonin and , if so , to identify the receptor subtype involved . 8 - hydroxy - 2 - ( di-n-propylamino ) tetralin ( 8 - OH-DPAT ) , a P08908 REA / 7 receptor agonist , stimulated P01148 REA release from GT1 - 1 cells . This effect was blocked by ritanserin , a 5 - HT2 / 7 receptor antagonist , but not by SDZ -216-525 , a P08908 REA antagonist . Basal P01148 REA release was not affected by the 5 - HT2 agonist DOI . Reverse transcription and polymerase chain reaction technique ( RT-PCR ) was used in order to identify P08908 REA and P34969 REA receptor mRNA in immortalized P01148 REA cell lines . GT1 - 1 cells express mRNA for the P34969 REA , but not the P08908 REA receptor subtypes . These results demonstrate a direct stimulatory effect of serotonin on P01148 REA release via P34969 REA receptor .

Immunomodulatory drugs inhibit expression of cyclooxygenase - 2 from P01375 REA , IL - 1beta , and LPS-stimulated human PBMC in a partially P22301 REA - dependent manner . Immunomodulatory drugs ( IMiDs ) are potent inhibitors of P01375 REA and IL - 1beta and elevators of P22301 REA production in LPS-stimulated human PBMC . They are currently in clinical trials for various diseases , including multiple myeloma , myelodysplastic syndrome , and melanoma . In the present study , we have investigated the effects of thalidomide , DB00480 MEN and CC - 4047 on the expression of P35354 REA by stimulated PBMC . Our results show that thalidomide and IMiDs inhibited the expression of P35354 REA but not the P23219 REA protein in LPS - P01375 REA and IL - 1beta stimulated PBMC and shortened the half-life of P35354 REA mRNA in a dose-dependent manner . They also inhibited the synthesis of prostaglandin E2 from LPS-stimulated PBMC . While anti - P01375 REA or IL - 1beta neutralizing antibodies had no effect on P35354 REA expression , anti - P22301 REA neutralizing antibody elevated the expression of P35354 REA mRNA , and protein from treated PBMC . These data suggest that the anti-inflammatory and anti-tumor effects of IMiDs may be due in part to elevation of P22301 REA production and its subsequent inhibition of P35354 REA expression .

Prolonged effects of tumor necrosis factor-alpha on anterior pituitary hormone release . We examined the chronic ( 72 h ) effects of 30 ng / ml recombinant murine tumor necrosis factor ( P01375 REA ) - alpha on release of immunoreactive growth hormone ( GH ) , prolactin ( PRL ) , thyrotropin ( DB00024 ) , and DB00024 glycosylation , as assessed by lectin binding , in cultured rat anterior pituitary cells . In cultured cells from adult female rats , P01375 REA significantly suppressed basal and GH-releasing hormone ( P01148 REA ) - stimulated GH release . P01375 REA also suppressed basal PRL release and completely abolished the PRL response to TRH ( 0.1- 10 nM ) . Whereas P01375 REA reduced basal DB00024 release , it significantly enhanced the maximal DB00024 response to TRH . P01375 REA did not affect the concanavalin A and lentil lectin binding of DB00024 accumulated in the medium during the 4 - day culture , but significantly decreased the lentil lectin binding of DB00024 released in response to acute TRH stimulation . P01375 REA significantly enhanced the inhibitory effect of somatostatin on stimulated PRL release , but not on GH or DB00024 release . Compared to cell cultures from adult female rats , in anterior pituitary cell cultures from 12 - day-old rats the effects of prolonged exposure to P01375 REA on hormone release were diminished or absent . Pituitary hormone release was unaffected by acute ( 3 h ) exposure to P01375 REA . These results demonstrate a direct effect of P01375 REA on anterior pituitary hormone release , which is cell-type specific and age dependent .

Solution structure and backbone dynamics of the catalytic domain of matrix metalloproteinase - 2 complexed with a hydroxamic acid inhibitor . P08253 REA is a member of the matrix metalloproteinase family that has been implicated in tumor cell metastasis and angiogenesis . Here , we describe the solution structure of a catalytic domain of P08253 REA complexed with a hydroxamic acid inhibitor ( DB01630 MEN ) , determined by three-dimensional heteronuclear NMR spectroscopy . The catalytic domain , designated MMP - 2C , has a short peptide linker replacing the internal fibronectin-domain insertion and is enzymatically active . Distance geometry-simulated annealing calculations yielded 14 converged structures with atomic root-mean-square deviations ( r . m . s . d . ) of 1.02 and 1.62 A from the mean coordinate positions for the backbone and for all heavy atoms , respectively , when 11 residues at the N-terminus are excluded . The structure has the same global fold as observed for other MMP catalytic domains and is similar to previously solved crystal structures of P08253 REA . Differences observed between the solution and the crystal structures , near the bottom of the S1 ' specificity loop , appear to be induced by the large inhibitor present in the solution structure . The MMP - 2C solution structure is compared with P22894 REA crystal structure bound to the same inhibitor to highlight the differences especially in the S1 ' specificity loop . The finding provides a structural explanation for the selectivity between P08253 REA and P22894 REA that is achieved by large inhibitors .

Enhanced immune system regeneration in humans following allogeneic or autologous hemopoietic stem cell transplantation by temporary sex steroid blockade . PURPOSE : To determine if temporarily blocking sex steroids prior to stem cell transplantation can increase thymus function and thus enhance the rate of T cell regeneration . EXPERIMENTAL DESIGN : This was a pilot study of luteinizing hormone-releasing hormone agonist ( P01148 REA - A ) goserelin given 3 weeks prior to allogeneic or autologous hemopoietic stem cell transplantation and administered up to 3 months posttransplantation . Patients ( with or without P01148 REA - A administration ) were assessed from 1 week to 12 months posttransplantation for multiple immunologic variables by flow cytometry ( particularly naïve T cells ) , quantitative PCR to assess T-cell receptor excision circle levels ( as a correlate of thymus function ) , CDR 3 length analysis to determine the variability of the TCR repertoire , and in vitro assays to determine functional T cell responses . RESULTS : P01148 REA - A administration prior to stem cell transplantation significantly increased neutrophil and lymphocyte numbers within the first month of posttransplantation . Most importantly , total and naïve P01730 REA ( + ) T cell regeneration together with T-cell receptor excision circle production , T cell repertoire regeneration , and peripheral T cell function were also significantly enhanced at multiple time points posttransplant . In addition , an increase in disease-free survival ( P = 0.04 ) was seen in the autologous setting . Although P01148 REA - A administration increased T cell responses in vitro , it did not exacerbate graft-versus-host disease in the allogeneic setting . CONCLUSIONS : This study provides an important new approach to the improvement of immune reconstitution in patients undergoing hemopoietic stem cell transplantation and may have generic applications in many T cell-based disorders .

A nitric oxide-dependent cross-talk between class I and III histone deacetylases accelerates skin repair . In a mouse model of skin repair we found that the class I-IIa histone deacetylase inhibitor trichostatin A accelerated tissue regeneration . Unexpectedly , this effect was suppressed by Sirtinol , a class III histone deacetylase ( HDAC ) ( sirtuin ) - selective inhibitor . The role of sirtuins ( SIRTs ) was then investigated by using resveratrol and a novel Q96EB6 -2-3 activator , the MC2562 compound we synthesized recently . Both resveratrol and MC2562 were effective in accelerating wound repair . The local administration of natural or synthetic SIRT activators , in fact , significantly accelerated skin regeneration by increasing keratinocyte proliferation . In vitro experiments revealed that the activation of SIRTs stimulated keratinocyte proliferation via endothelial NO synthase phosphorylation and NO production . In this condition , the class I member Q92769 REA was found S-nitrosylated on cysteine , a post-transduction modification associated with loss of activity and DNA binding capacity . After deacetylase inhibitor or SIRT activator treatment , ChIP showed , in fact , a significant Q92769 REA detachment from the promoter region of insulin growth factor I ( P05019 REA ) , fibroblast growth factor 10 ( O15520 REA ) , and Epithelial Growth Factor ( P01133 REA ) , which may be the final recipients and effectors of the SIRT-NO-HDAC signaling cascade . Consistently , the effect of SIRT activators was reduced in the presence of NG-nitro-L-arginine methyl ester ( L-NAME ) , a general inhibitor of NO synthesis . In conclusion , the NO-dependent cross-talk among class III and I histone deacetylases suggests an unprecedented signaling pathway important for skin repair .

Effect of growth factors on nuclear and mitochondrial ADP-ribosylation processes during astroglial cell development and aging in culture . Epidermal growth factor ( P01133 REA ) , basic fibroblast growth factor ( P09038 REA ) , insulin-like growth factor-I ( P05019 REA ) and insulin ( P01308 REA ) are powerful mitogens and may regulate gene expression in cultured astrocytes by ADP-ribosylation process . Nuclear poly-ADP ribose polymerase ( PARP ) and mitochondrial monoADP-ribosyltransferase ( P09874 REA ) are the key enzymes involved in poly-ADP-ribosylation and mono ADP-ribosylation , respectively . In this investigation the effect of P01133 REA , P09038 REA , P05019 REA or P01308 REA on nuclear PARP and mitochondrial P09874 REA activities were assessed in nuclei and mitochondria purified from developing ( 30 DIV ) or aging ( 90 and 190 DIV ) primary rat astrocyte cultures . A marked increase of PARP activity in P09038 REA or P05019 REA treated astroglial cell cultures at 30 DIV was found . Nuclear PARP and mitochondrial P09874 REA activities were greatly stimulated by treatment with P01133 REA or P01308 REA alone or together in astrocyte cultures at 30 DIV . Nuclear PARP and mitochondrial P09874 REA activities showed a more remarkable increase in control untreated astrocyte cultures at 190 DIV than at 90 DIV . These findings suggest that ADP-ribosylation process is involved in DNA damage and repair during cell differentiation and aging in culture . Twelve hours treatment with P01133 REA , P01308 REA or P09038 REA significantly stimulated nuclear PARP and mitochondrial P09874 REA activities in 190 DIV aging astrocyte cultures . The above results indicate that P01133 REA , P01308 REA and P09038 REA may play a crucial role in the post-translational modification of chromosomal proteins including ADP-ribosylation process in in vitro models . This suggests that growth factors regulate genomic stability in glial cells during development and maturation , stimulating nuclear and mitochondrial ADP-ribosylation processes in developing or aging astrocyte cultures .

Activation of gonadotropin-releasing hormone receptors induces a long-term enhancement of excitatory postsynaptic currents mediated by ionotropic glutamate receptors in the rat hippocampus . Whole-cell patch-clamp recordings were made from P00915 REA pyramidal neurons of the rat hippocampus to study the modulation of gonadotropin-releasing hormone ( DB00644 ) on synaptic transmission mediated by ionotropic glutamate receptors . DB00007 SUB ( 10 ( - 9 ) - 10 ( - 7 ) M ) , a specific DB00644 analog , concentration-dependently elicited a long-lasting potentiation of excitatory postsynaptic currents ( EPSCs ) mediated by ionotropic glutamate receptors . P30968 REA - induced synaptic potentiation was blocked by 1 microM [ Acetyl -3,4- dehydro-Pro 1 , D-p-F-Phe 2 , D-Trp 3,6 ] - P01148 REA , a specific P30968 REA antagonist . Furthermore , P30968 REA - induced synaptic potentiation was associated with the stimulation of protein kinase C ( PKC ) , being considerably attenuated by a potent PKC inhibitor ( 30 microM H - 7 ) . The results suggest a long-term enhanced modulation of DB00644 on synaptic transmission mediated by ionotropic glutamate receptors , possibly via the actions of PKC in the hippocampus that is an important integrative system in the regulation of reproductive processes .

DB00644 agonists reduce the migratory and the invasive behavior of androgen-independent prostate cancer cells by interfering with the activity of P05019 REA . Androgen-independent prostate carcinoma is characterized by a high proliferation rate and by a strong metastatic behavior . We have previously shown that DB00644 agonists exert a direct and specific inhibitory action on the proliferation of androgen-independent prostate cancer cells ( DU 145 ) . These compounds mainly act by interfering with the mitogenic activity of growth factors , such as the insulin-like growth factor-I ( P05019 REA ) . The present experiments were performed to clarify whether DB00644 agonists might also affect the migratory and the invasive behavior of androgen-independent prostate cancer cells and to define their mechanism of action . First we showed that the DB00644 agonist DB00007 SUB reduces the migration of DU 145 cells towards a chemoattractant and their ability to invade a reconstituted basement membrane . Experiments were then performed to clarify whether the DB00644 agonist might act by interfering with the pro-metastatic activity of P05019 REA . We found that , in androgen-independent prostate cancer cells , DB00007 SUB : a ) interferes with the P05019 REA system ( receptor protein expression and tyrosine-phosphorylation ) ; b ) abrogates the P05019 REA - induced phosphorylation of Akt ( a kinase previously shown by us to mediate the pro-metastatic activity of P05019 REA in prostate cancer cells ) ; c ) counteracts the migration and the invasive activity of the cells stimulated by P05019 REA ; d ) abolishes the effects of P05019 REA on cell morphology , on actin cytoskeleton organization and on alphavbeta 3 integrin expression / cellular localization . These data indicate that DB00644 agonists , in addition to their well known antiproliferative effect , can also exert a significant inhibitory activity on the migratory and invasive behavior of androgen-independent prostate cancer cells , expressing the P30968 REA . DB00644 agonists act by interfering with the pro-metastatic activity of the growth factor P05019 REA .

Administration of adenosine diphosphate-ribosyl transferase antagonist allows in vivo control of anti-dinitrophenyl response . DB03073 MEN ( 3MB ) is one of a series of chemical inhibitors of the nuclear enzyme adenosine diphosphate ( ADP ) - ribosyl transferase ( P09874 REA ) , which has been shown to inhibit cell differentiation in vitro , but has no effect on differentiation independent proliferation . Treatment of mice with an optimal concentration of 3MB ( 20 mg / kg body weight ) at or 1 day after dinitrophenyl-keyhole limpet haemocyanin ( DNP-KLH ) immunisation reduced anti-DNP plaque-forming cell ( P27918 REA ) numbers to less than 10 % of those of control animals . The period for maximum P27918 REA suppression showed a narrow time window relative to immunisation , suggesting that in vivo , as in vitro , 3 MB was acting only on those lymphocytes differentiating in response to antigen . Experimental findings showed that it was possible to select for P27918 REA derived from different populations of DNP-responsive lymphocytes by adjusting the time of 3MB treatment relative to immunisation . When 3MB was used with antigen priming , the residual P27918 REA showed a lower average affinity than P27918 REA in mice treated with 3MB 3 days after priming , suggesting a differential selection of those lymphocytes responding either ' early ' or ' late ' in the primary immune response .

Q14703 REA lyase in thymic perivascular spaces promotes egress of mature thymocytes via up-regulation of P21453 REA . DB03203 MEN 1 - phosphate ( Q14703 REA ) and P21453 REA ( P21453 REA ) play an important role in the egress of mature P01730 REA or CD8 single-positive ( SP ) thymocytes from the thymus . DB08868 hydrochloride ( FTY 720 ) , an P21453 REA functional antagonist , induced significant accumulation of CD62L ( high ) Q07108 ( low ) mature SP thymocytes in the thymic medulla . Immunohistochemical staining using anti - P21453 REA antibody revealed that P21453 REA is predominantly expressed on thymocytes in the thymic medulla and is strongly down-regulated even at 3h after FTY 720 administration . 2 - Acetyl - 4 - tetrahydroxybutylimidazole ( THI ) , an Q14703 REA lyase inhibitor , also induced accumulation of mature SP thymocytes in the thymic medulla with an enlargement of the perivascular spaces ( P15151 REA ) . At 6h after THI administration , P21453 REA - expressing thymocytes reduced partially as if to form clusters and hardly existed in the proximity of CD31 - expressing blood vessels in the thymic medulla , suggesting Q14703 REA lyase expression in the cells constructing thymic medullary P15151 REA . To determine the cells expressing Q14703 REA lyase in the thymus , we newly established a mAb ( YK19 - 2 ) specific for mouse Q14703 REA lyase . Immunohistochemical staining with YK19 - 2 revealed that Q14703 REA lyase is predominantly expressed in non-lymphoid thymic stromal cells in the thymic medulla . In the thymic medullary P15151 REA , Q14703 REA lyase was expressed in ER-TR 7 - positive cells ( reticular fibroblasts and pericytes ) and CD31 - positive vascular endothelial cells . Our findings suggest that Q14703 REA lyase expressed in the thymic medullary P15151 REA keeps the tissue Q14703 REA concentration low around the vessels and promotes thymic egress via up-regulation of P21453 REA .

P10415 REA / BCL-X ( L ) inhibition induces apoptosis , disrupts cellular calcium homeostasis , and prevents platelet activation . Apoptosis in megakaryocytes results in the formation of platelets . The role of apoptotic pathways in platelet turnover and in the apoptotic-like changes seen after platelet activation is poorly understood . DB05764 MEN ( Navitoclax ) , a specific inhibitor of antiapoptotic P10415 REA proteins , which is currently being evaluated in clinical trials for the treatment of leukemia and other malignancies , induces a dose-limiting thrombocytopenia . In this study , the relationship between P10415 REA / BCL-X ( L ) inhibition , apoptosis , and platelet activation was investigated . Exposure to DB05764 MEN induced apoptosis but repressed platelet activation by physiologic agonists . Notably , DB05764 MEN induced an immediate calcium response in platelets and the depletion of intracellular calcium stores , indicating that on P10415 REA / BCL-X ( L ) inhibition platelet activation is abrogated because of a diminished calcium signaling . By comparing the effects of DB05764 MEN and its analog ABT - 737 on platelets and leukemia cells from the same donor , we show , for the first time , that these P10415 REA / BCL-X ( L ) inhibitors do not offer any selective toxicity but induce apoptosis at similar concentrations in leukemia cells and platelets . However , reticulated platelets are less sensitive to apoptosis , supporting the hypothesis that treatment with DB05764 MEN induces a selective loss of older platelets and providing an explanation for the transient thrombocytopenia observed on DB05764 MEN treatment .