Language：English   Publishing type：Research paper (scientific journal)   Publisher：Scientific Reports  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Scientific Reports  

The unfolded protein response (UPR) controls protein homeostasis through transcriptional and translational regulation. However, dysregulated UPR signaling has been associated with the pathogenesis of many human diseases. Therefore, the compounds modulating UPR may provide molecular insights for these pathologies in the context of UPR. Here, we screened small-molecule compounds that suppress UPR, using a library of Myanmar wild plant extracts. The screening system to track X-box binding protein 1 (XBP1) splicing activity revealed that the ethanol extract of the Periploca calophylla stem inhibited the inositol-requiring enzyme 1 (IRE1)-XBP1 pathway. We isolated and identified periplocin as a potent inhibitor of the IRE1-XBP1 axis. Periplocin also suppressed other UPR axes, protein kinase R-like endoplasmic reticulum kinase (PERK), and activating transcription factor 6 (ATF6). Examining the structure-activity relationship of periplocin revealed that cardiac glycosides also inhibited UPR. Moreover, periplocin suppressed the constitutive activation of XBP1 and exerted cytotoxic effects in the human multiple myeloma cell lines, AMO1 and RPMI8226. These results reveal a novel suppressive effect of periplocin or the other cardiac glycosides on UPR regulation, suggesting that these compounds will contribute to our understanding of the pathological or physiological importance of UPR.

DOI： 10.1038/s41598-021-89074-x

PubMed

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：J Biol Chem.  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：J Biol Chem.  

Smad proteins are transcriptional regulators activated by TGF-β. They are known to bind to two distinct Smad-responsive motifs, namely the Smad-binding element (SBE) (5'-GTCTAGAC-3') and CAGA motifs (5'-AGCCAGACA-3' or 5'-TGTCTGGCT-3'). However, the mechanisms by which these motifs promote Smad activity are not fully elucidated. In this study, we performed DNA CASTing, binding assays, ChIP sequencing, and quantitative RT-PCR to dissect the details of Smad binding and function of the SBE and CAGA motifs. We observed a preference for Smad3 to bind CAGA motifs and Smad4 to bind SBE, and that either one SBE or a triple-CAGA motif forms a cis-acting functional half-unit for Smad-dependent transcription activation; combining two half-units allows efficient activation. Unexpectedly, the extent of Smad binding did not directly correlate with the abilities of Smad-binding sequences to induce gene expression. We found that Smad proteins are more tolerant of single bp mutations in the context of the CAGA motifs, with any mutation in the SBE disrupting function. CAGA and CAGA-like motifs but not SBE are widely distributed among stimulus-dependent Smad2/3-binding sites in normal murine mammary gland epithelial cells, and the number of CAGA and CAGA-like motifs correlates with fold-induction of target gene expression by TGF-β. These data, demonstrating Smad responsiveness can be tuned by both sequence and number of repeats, provide a compelling explanation for why CAGA motifs are predominantly used for Smad-dependent transcription activation in vivo.

DOI： 10.1074/jbc.RA119.009877

PubMed

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Language：English  

DOI： 10.1002/1873-3468.13314

Scopus

PubMed

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

The p53 tumor suppressor plays critical roles in cell cycle regulation and apoptotic cell death in response to various cellular stresses, thereby preventing cancer development. Therefore, the activation of p53 through small molecules is an attractive therapeutic strategy for the treatment of cancers retaining wild-type p53. We used a library of 700 Myanmar wild plant extracts to identify small molecules that induce p53 transcriptional activity. A cell-based screening method with a p53-responsive luciferase-reporter assay system revealed that an ethanol extract of Oroxylum indicum bark increased p53 transcriptional activity. Chrysin was isolated and identified as the active ingredient in the O. indicum bark extract. A treatment with chrysin increased p53 protein expression and the p53-mediated expression of downstream target genes, and decreased cell viability in MCF7 cells, but not in p53-knockdown MCF7 cells. We also found that chrysin activated the ATM-Chk2 pathway in the absence of DNA damage. Hence, the inactivation of the ATM-Chk2 pathway suppressed p53 activation induced by chrysin. These results suggest the potential of chrysin as an anti-cancer drug through the activation of p53 without DNA damage.

DOI： 10.3390/molecules23061394

PubMed

Authorship：Lead author   Language：English   Publishing type：(MISC) Introduction and explanation (scientific journal)   Publisher：Oxford University Press  

Smad3 and STAT3 are intracellular molecules that transmit signals from plasma membrane receptors to the nucleus. Smad3 operates downstream of growth/differentiation factors that utilize activin receptor-like kinase (ALK)-4, 5, or 7, such as transforming growth factor-β (TGF-β), activin, and myostatin. STAT3 principally functions downstream of cytokines that exert their effects via gp130 and Janus family kinases, including interleukin-6 (IL-6), leukemia inhibitory factor (LIF), and oncostatin M. Accumulating evidence indicates that Smad3 and STAT3 engage in crosstalk in a highly context-dependent fashion, cooperating in some conditions while acting antagonistically each other in others. Here, we review the crosstalk between Smad3 and STAT3 in various biological contexts, including early tumorigenesis, epithelial-mesenchymal transition, fibrosis, and T cell differentiation.

DOI： 10.1093/abbs/gmx118

Scopus

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY  

Activating transcription factor 4 (ATF4) is well known for its role in the endoplasmic reticulum (ER) stress response. ATF4 also transcriptionally induces multiple effectors that determine cell fate depending on cellular context. In addition, ATF4 can communicate both pro-apoptotic and pro-survival signals. How ATF4 mediates its prosurvival roles, however, requires further investigation. Here, we report that the CDK inhibitor p21 is a novel target gene of ATF4. We identified two ATF4-responsive elements, one of which directly binds ATF4, within the first intron of the p21 gene. Importantly, overexpression of p21 enhances cell survival following ER stress induction, while p21 knockdown increases cell death. These results suggest that p21 induction plays a vital role in the cellular response to ER stress and indicate that p21 is a prosurvival effector of ATF4.

DOI： 10.1002/1873-3468.12869

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1002/1873-3468.12869.

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Transforming growth factor beta (TGF-beta) signaling facilitates tumor development during the advanced stages of tumorigenesis, but induces cell-cycle arrest for tumor suppression during the early stages. However, the mechanism of functional switching of TGF-beta is still unknown, and it is unclear whether inhibition of TGF-beta signaling results amelioration or exacerbation of cancers. Here we show that the tumor suppressor p53 cooperates with Smad proteins, which are TGF-beta signal transducers, to selectively activate plasminogen activator inhibitor type-1 (PAI-1) transcription. p53 forms a complex with Smad2/3 in the PAI-1 promoter to recruit histone acetyltransferase CREB-binding protein (CBP) and enhance histone H3 acetylation, resulting in transcriptional activation of the PAI-1 gene. Importantly, p53 is required for TGF-beta-induced cytostasis and PAI-1 is involved in the cytostatic activity of TGF-beta in several cell lines. Our results suggest that p53 enhances TGF-beta-induced cytostatic effects by activating PAI-1 transcription, and the functional switching of TGF-beta is partially caused by p53 mutation or p53 inactivation during cancer progression. It is expected that these findings will contribute to optimization of TGF-beta-targeting therapies for cancer.

DOI： 10.1038/srep35483

Web of Science

Language：English   Publishing type：(MISC) Introduction and explanation (scientific journal)  

Language：English   Publishing type：(MISC) Introduction and explanation (scientific journal)  

Language：English   Publishing type：(MISC) Introduction and explanation (scientific journal)   Publisher：BENTHAM SCIENCE PUBL LTD  

Tribbles-related protein (TRB) family members are the mammalian orthologs of Drosophila tribbles. Tribbles was originally identified as a cell cycle regulator during Drosophila development. Tribbles genes are evolutionary conserved, and three TRB genes (TRB1, TRB2 and TRB3) have been identified in mammals. TRBs are considered pseudokinases because they lack an ATP binding site or one of the conserved catalytic motifs essential for kinase activity. Instead, TRBs play important roles in various cellular processes as scaffolds or adaptors to promote the degradation of target proteins and to regulate several key signaling pathways. Recent research has focused on the role of TRBs in tumorigenesis and neoplastic progression. In this review, we focus on the physiological roles of TRB family members in tumorigenesis through the regulation of the ubiquitin-proteasome system and discuss TRBs as biomarkers or potential therapeutic targets in cancer.

DOI： 10.2174/1568009616666151112122645

Web of Science

Language：English   Publishing type：(MISC) Introduction and explanation (scientific journal)   Publisher：BENTHAM SCIENCE PUBL LTD  

Epithelial-mesenchymal transition (EMT) plays an important role in the development of tumor metastases by facilitating cell migration and invasion. One of the hallmarks of EMT is the diminished expression of E-cadherin and gain of mesenchymal traits, which are regulated by core EMT-inducing transcriptional factors (EMT-TFs), such as Snail/Slug, ZEB1/ZEB2, and Twist1. EMT-TFs are known to be extremely labile proteins, and their protein levels are tightly controlled by the ubiquitin-proteasome system (UPS). Several E3 ubiquitin ligases have been shown to play crucial roles in the regulation of EMT, and genetic aberrations and alterations in these ligases have been detected in human cancer. In this review, we focused on EMT-TFs, describing the UPS controlling their activities and functions in cancer. A deeper understanding of the role of UPS in the regulation of EMT will provide valuable information for the development of effective anti-metastatic drugs to modulate the malignant processes mediated by EMT.

DOI： 10.2174/1568009616666151112122126

Web of Science

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PHARMACEUTICAL SOC JAPAN  

Tribbles 1 (TRB1), a member of the Tribbles family, is a pseudokinase that is conserved among species and implicated in various human diseases including leukemia, cardiovascular diseases, and metabolic disorders. However, the role of TRB1 in the immune response is not understood. To evaluate this role, we examined regulation of TRB1 expression and the function of TRB1 in interleukin-2 (IL-2) induction in Jurkat cells, a human acute T cell leukemia cell line. We found that TRB1 was strongly induced by phorbol 12-myristate 13-acetate (PMA) and ionomycin in these cells. IL-2 expression was induced in Jurkat cells activated by PMA and ionomycin; however, knockdown of TRB1 resulted in decreased induction of IL-2. TRB1 null Jurkat cells established using the CRISPR/Cas9 system also showed reduction of IL-2 expression on PMA/ionomycin stimulation. TRB1 knockdown also markedly inhibited IL-2 promoter activation. To determine the mechanism of the stimulatory effect on IL-2 induction, we focused on histone deacetylases (HDACs), and found that HDAC1 preferentially interacts with TRB1. TRB1 suppressed the interaction of HDAC1 with nuclear factor of activated T cells 2 (NFAT2), which is a crucial transcription factor for IL-2 induction. These results indicate that TRB1 is a positive regulator of IL-2 induction in activated T cells.

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER PHYSIOLOGICAL SOC  

Transient receptor potential ankyrin 1 (TRPA1) is a Ca2+-permeable nonselective cation channel expressed in neuronal and nonneuronal cells and plays an important role in acute and inflammatory pain. Here, we show that an NADPH oxidase (NOX) inhibitor, diphenyleneiodonium (DPI), functions as a TRPA1 activator in human embryonic kidney cells expressing human TRPA1 (HEK-TRPA1) and in human fibroblast-like synoviocytes. Application of DPI at 0.03-10 mu M induced a Ca2+ response in HEK-TRPA1 cells in a concentration-dependent manner. The Ca2+ response was effectively blocked by a selective TRPA1 antagonist, HC-030031 (HC). In contrast, DPI had no effect on HEK cells expressing TRPV1-V4 or TRPM8. Four other NOX inhibitors, apocynin (APO), VAS2870 (VAS), plumbagin, and 2-acetylphenothiazine, also induced a Ca2+ response in HEK-TRPA1 cells, which was inhibited by pretreatment with HC. In the presence of 5 mM glutathione, the Ca2+ response to DPI was effectively reduced. Moreover, mutation of cysteine 621 in TRPA1 substantially inhibited the DPI-induced Ca2+ response, while it did not inhibit the APO- and VAS-induced responses. The channel activity was induced by DPI in excised membrane patches with both outside-out and inside-out configurations. Internal application of neomycin significantly inhibited the DPI-induced inward currents. In inflammatory synoviocytes with TRPA1, DPI evoked a Ca2+ response that was sensitive to HC. In mice, intraplantar injection of DPI caused a pain-related response which was inhibited by preadministration with HC. Taken together, our findings demonstrate that DPI and other NOX inhibitors activate human TRPA1 without mediating NOX.

DOI： 10.1152/ajpcell.00182.2013

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Aims: The vanilloid type 4 transient receptor potential channel (TRPV4) is a potential environmental sensor to multiple stimuli in many types of cells. In this study, we show that TRPV4 activated by 4 alpha-phorbol 12,13-didecanoate (4 alpha PDD) and hypo-osmotic stimulation (HOS) is a regulator of intracellular calcium ([Ca2+](i))) in human brain capillary endothelial cells (HBCEs), and its activation can partially regulate cell proliferation of HBCEs.
Main methods: The expression of TRPV4 in HBCEs was analyzed at the mRNA and protein levels. The function of TRPV4 in HBCEs was evaluated using a TRPV4 agonist, 4 alpha PDD, and HOS while measuring[Ca2+](i) and membrane currents.
Key findings: Analysis of the mRNA transcripts of the TRPV subfamily revealed that TRPV2 and TRPV4 were expressed in HBCEs. Immunoreactivity to the TRPV4 protein was also detected in HBCEs, which were positively stained by von Willebrand factor and CD31. When 4 alpha PDD was applied, [Ca2+](i) in HBCEs was elevated in a concentration-dependent manner. In addition, exposure of HBCEs to HOS at 228 mOsm induced an elevation of [Ca2+](i). Application of 4 alpha PDD also activated non-selective cation currents (NSCCs). Pretreatment of HBCEs with short interference RNA targeting TRPV4 (siRNA) significantly reduced the 4 alpha PDD-induced elevation of [Ca2+](i). When HBCEs were treated for 24 h with concentrations of 4 alpha PDD between 0.3 and 3 mu M, the cell proliferation was potentiated in a concentration-dependent manner. The potentiation was partially inhibited in HBCEs treated with siRNA.
Significance: These data suggest that endogenous TRPV4, which functions as a regulator of [Ca2+](i) in HBCEs, partially controls cell proliferation. (C) 2013 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.lfs.2013.01.002

Web of Science

Language：English   Publishing type：(MISC) Summary of the papers read (international conference)   Publisher：JAPANESE PHARMACOLOGICAL SOC  

Web of Science

Language：English   Publishing type：(MISC) Summary of the papers read (international conference)   Publisher：JAPANESE PHARMACOLOGICAL SOC  

Web of Science

Language：English   Publishing type：(MISC) Summary of the papers read (international conference)   Publisher：JAPANESE PHARMACOLOGICAL SOC  

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC  

Transient receptor potential ankyrin repeat 1 (TRPA1) forms calcium (Ca2+)- and zinc (Zn2+)-permeable ion channels that sense noxious substances. Despite the biological and clinical importance of TRPA1, there is little knowledge of the mechanisms that lead to transcriptional regulation of TRPA1 and of the functional role of transcriptionally induced TRPA1. Here we show induction of TRPA1 by inflammatory mediators and delineate the underlying molecular mechanisms and functional relevance. In human fibroblast-like synoviocytes, key inflammatory mediators (tumor necrosis factor-alpha and interleukin-1 alpha) induced TRPA1 gene expression via nuclear factor-kappa B signaling and downstream activation of the transcription factor hypoxia-inducible factor-1 alpha (HIF1 alpha). HIF1 alpha unexpectedly acted by binding to a specific hypoxia response element-like motif and its flanking regions in the TRPA1 gene. The induced TRPA1 channels, which were intrinsically activated by endogenous hydrogen peroxide and Zn2+, suppressed secretion of interleukin-6 and interleukin-8. The data suggest a previously unrecognized HIF1 alpha mechanism that links inflammatory mediators to ion channel expression.

DOI： 10.1074/jbc.M112.361139

Web of Science

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PHARMACEUTICAL SOC JAPAN  

Rheumatoid arthritis (RA) is a disease with significant gender differences in its prevalence and clinical features. Interleukin (IL)-1 and tumor necrosis factor (TNF) alpha produced by synoviocytes are principle inflammatory and destructive mediators of RA. We found that a potent androgen, 5 alpha-dihydrotestosterone (DHT) inhibits IL-1 alpha-induced production and mRNA expression of IL-8, IL-6 and IL-1 beta from RA patient-derived fibroblast-like synovial cell line MH7A. Promoter analysis of the IL-8 gene revealed that nuclear factor (NF)-kappa B activation is critical for its transcriptional activation by IL-1 alpha, and DHT inhibited the IL-1 alpha-induced NF-kappa B activation in a manner dependent on the androgen receptor (AR). DHT also inhibited the effects of TNF alpha on the cells overexpressed with AR, indicating that sufficient expression level of functional AR was necessary for the inhibitory effect of DHT on TNF alpha. These results suggest that androgen contributes to the prevention against RA and its gender difference by inhibiting IL-1 alpha or TNF alpha-induced proinflammatory cytokine production from synovial fibroblast-like cells by inhibiting NF-kappa B activation in a manner depending on AR.

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：(MISC) Summary of the papers read (international conference)   Publisher：JAPANESE PHARMACOLOGICAL SOC  

Web of Science

Language：English   Publishing type：(MISC) Summary of the papers read (international conference)   Publisher：JAPANESE PHARMACOLOGICAL SOC  

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Aims: Vanilloid type transient receptor potential channel (TRPV) could be a potential environmental sensor to multiple stimuli in many types of cells. In this Study, we provide the first evidence of functional vanilloid type 4 transient receptor potential channel (TRPV4) in rat cardiac fibroblasts (CFs).
Main methods: Expression of TRPV4 in Us was analyzed at mRNA and protein level. Function of TRPV4 in Us was evaluated using a selective TRPV4 agonist, 4 alpha-phorbol 12,13-didecanoate (4 alpha PDD) while measuring intracellular Ca(2+) concentration ([Ca(2+)](i)) and membrane currents.
Key findings: Analysis of expression of mRNA transcripts of TRPV subfamily revealed that TRPV2 and TRPV4 were expressed in Us. Significant immunoreactivity to TRPV4 protein was also detected in CFs. When 4 alpha PDD was applied to CFs, [Ca(2+)](i) was elevated in a concentration-dependent manner. The elevation of [Ca(2+)](i) was abolished by the removal of external Ca(2+) and by ruthenium red (RuR). 4 alpha PDD also activated non-selective cation currents (NSCCs), which were suppressed by RuR. Moreover, pretreatment of Us with short interference RNA (siRNA) targeting TRPV4 significantly reduced both 4 alpha PDD-induced elevation of [Ca(2+)](i) and NSCC.
Significance: These results provide strong evidence that endogenous TRPV4 functions as an important regulator of [Ca(2+)](i) in CFs. (C) 2009 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.lfs.2009.10.013

Web of Science

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER PHYSIOLOGICAL SOC  

Itoh Y, Hatano N, Hayashi H, Onozaki K, Miyazawa K, Muraki K. An environmental sensor, TRPV4 is a novel regulator of intracellular Ca2+ in human synoviocytes. Am J Physiol Cell Physiol 297: C1082-C1090, 2009. First published September 16, 2009; doi:10.1152/ajpcell.00204.2009.-The activation of a vanilloid type 4 transient receptor potential channel (TRPV4) has an obligatory role in regulation of intracellular Ca2+ (Ca-i(2+)) in several types of cells including vascular and sensory organs. In this study, we provide evidence that TRPV4 is a functional regulator of Ca-i(2+) in human synoviocytes. Although significant expression of TRPV4 in synoviocytes from patients with (RA) and without (CTR) rheumatoid arthritis was detected at mRNA and protein level, those in the human fibroblast-like synoviocyte line MH7A were rather lower. Consistently, the selective TRPV4 agonist 4 alpha-phorbol 12,13-didecanoate (4 alpha PDD) effectively elevated Ca-i(2+) in the RA and CTR cells, which was abolished by the removal of external Ca2+. Moreover, the elevation was inhibited by ruthenium red, a blocker of TRPVs. In MH7A cells transfected with human TRPV4 (MH7A-V4), 4 alpha PDD elevated the Ca-i(2+) in a similar manner to those in the RA and CTR cells. Electrophysiological analysis also revealed that 4 alpha PDD activated nonselective cationic currents in RA cells. Application of 227 mosM solution to the RA and MH7A-V4 cells elevated their Ca-i(2+), but this does not occur when it was applied to MH7A cells. Treatment of RA but not MH7A cells with 4 alpha PDD for 24 h reduced their production of IL-8. These results suggest that an environmental sensor, TRPV4, is a novel regulator of intracellular Ca2+ in human synoviocytes.

DOI： 10.1152/ajpcell.00204.2009

Web of Science

Language：English   Publishing type：(MISC) Summary of the papers read (international conference)   Publisher：ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD  

DOI： 10.1016/j.cyto.2009.07.395

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPANESE PHARMACOLOGICAL SOC  

In this study, we provide evidence of critical changes in the expression of nonselective cation currents (NSCC) during culture in rat aortic myocytes. A selective TRPV4 agonist, 4a-phorbol 12,13-didecanoate (4 alpha PDD), had little effect on membrane currents and intracellular Ca(2+) (Ca(2+)) in freshly isolated cells from the aorta. In contrast, in cultured aortic myocytes with and without serum, 4aPDD at a concentration range between 0.3 and 3 mu M effectively elevated Ca(2+), which was abolished in the absence of external Ca(2+). Application of 4aPDD to cultured aortic myocytes also activated NSCC, which had a reversal potential of +3 mV. Both of these signals were blocked by ruthenium red (RuR), an effective blocker of TRPVs. Although the expression of TRPV4 mRNA transcript was found in cultured as well as non-cultured aortic rnyocytes, significant immunoreactivity to TRPV4 protein was only detected in cultured rat aortic myocytes. Moreover, cultured human pulmonary arterial smooth muscle cells (hPASM) had a substantial response to 4aPDD, which was susceptible to the removal of external Ca(2+) and application of RuR. These results provide a strong basis for our proposal that endogenous TRPV4 functions as an important regulator of Ca(2+)i in vascular tnyocytes under some physiological and pathophysiological conditions.

DOI： 10.1254/jphs.08133FP

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：MARY ANN LIEBERT INC  

Rheumatoid arthritis (RA) is characterized by proliferation of synoviocytes that produce proinflammatory cytokines, which are implicated in the pathogenesis of RA. When human fibroblast-like synoviocytes line MH7A was treated with cigarette smoke condensate (CSC), either mainstream or sidestream, expression levels of interleukin (IL)-1 alpha, IL-1 beta, IL-6, IL-8, and CYP1A1 mRNA were upregulated in both time- and dose-dependent manners. The upregulatory effects of CSC on these cytokines were not significantly inhibited by alpha-naphthoflavone, an aryl hydrocarbon receptor (AhR) antagonist, suggesting that the effects of CSC were independent of AhR. Cycloheximide treatment indicated that the augmenting effect of CSC on IL-1 alpha, IL-1 beta and IL-8, but not IL-6 and CYP1A1, mRNA expression requires de novo protein synthesis. CSC also induced cytokines at protein levels and further augmented the effects of tumor necrosis factor a on induction of these cytokines at both mRNA and protein levels. These results support the epidemiological studies indicating a strong association between heavy cigarette smoking and pathogenesis of RA.

DOI： 10.1089/jir.2007.0081

Web of Science

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPANESE PHARMACOLOGICAL SOC  

We characterized the effects of sphingosine-1-phosphate (S1P) on rat aortic myocytes with or without Culture. Application of SIP induced a small Ca2+ response in 40% freshly dispersed aortic myocytes, whereas S I P caused a larger Ca2+ response in 90% myocytes Cultured for 72 h. Concentration-response relationships of S I P in cultured myocytes were significantly different from that in non-cultured myocytes. Analysis of the expression of S I P-receptor mRNA transcripts revealed that S I P-receptor type 3 (S1P(3)) was significantly increased when myocytes were cultured for 24 h. Neither the removal of serum from culture medium nor pretreatment with pharmacological agents, Such as ERK, Rho, and PI3 kinase inhibitors, affected the progression of the S1P-induced Ca2+ response during culture. The sustained component of the Ca2+ response to S I P was sensitive to the removal of external Ca2+ and was effectively inhibited by inorganic Ca2+-channel blockers such as Gd3+, Cd2+, and Ni2+. However, application of S I P did not induce any contraction in organ-cultured as well as the intact aorta Muscle strip. Aortic inyocytes freshly dispersed from the organ-cultured muscle were also ineffective against SIP. Taken together, cell-culture changes the S1P(3)-mediated Ca2+ response to S1P in rat aortic myocytes.

DOI： 10.1254/jphs.08029FP

Web of Science

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PHARMACEUTICAL SOC JAPAN  

Rheumatoid arthritis (RA) is a chronic inflammatory disease that affects multiple synovial joints. Proinflammatory cytokines, such as interleukin-1 (IL-1) and tumor necrosis factor (TNF)alpha play important roles as principle inflammatory and destructive components of the disease. RA is known to be associated with significant gender differences in its prevalence and clinical features. We found that a potent androgen, 5 alpha-dihydrotestosterone (DHT) inhibits IL-1 alpha mRNA expression induced by TNF alpha and the DHT effect was inhibited by an androgen receptor antagonist, hydroxyflutamide (OHF). DHT inhibited the NF-kappa B activation induced by TNF alpha in a manner dependent on the androgen receptor (AR). These results suggest that DHT inhibits the TNF alpha-induced IL-1 alpha mRNA expression by inhibiting NF-kappa B activation, and contributes to the gender differences of the disease.

Web of Science

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER ASSOC IMMUNOLOGISTS  

Rheumatoid arthritis (RA) occurs four times more frequently in women than in men, although the mechanistic basis of the gender difference is unknown. RA is characterized by the overproliferation of synoviocytes producing prointlammatory cytokines such as IL-1. implicated in the pathogenesis of the disease. In this study we examined whether 17 beta-estradiol (E2) induced IL-1 alpha mRNA expression in the rheumatoid fibroblast-like cell line MH7A, as well as in primary synovial cells from RA patients, and investigated the underlying molecular mechanisms. E2 induced IL-1 alpha mRNA expression in both cell types in an estrogen receptor-dependent manner. In MH7A cells ER alpha but not ER beta mediated the effects of E2. Deletion and mutation analysis revealed that a GC-rich region within the IL-1 alpha gene promoter was responsible for the response to E2. EMSAs showed that Sp1 and Sp3 bound to the GC-rich region and that the transcriptional activity of Sp1 was up-regulated by the treatment with E2. Sp1 and ER alpha interacted physically regardless of the presence of E2. Physical interaction was also observed between ER alpha and histone deacetylase 2 (HDAC2), and E2 induced the dissociation of HDAC2 from ER alpha. These results suggest that E2 induces the dissociation of corepressor HDAC2 from ER alpha, which leads to the augmentation of Spl transcriptional activity through the GC-rich region within the IL-1 alpha gene promoter.

Web of Science

Language：English   Publishing type：Research paper (scientific journal)  

Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Smad proteins are crucial for the intracellular signaling of transforming growth factor-P (TGF-beta). Upon their receptor-induced activation, Smad proteins are phosphorylated and translocated to the nucleus to activate the transcription of a select set of target genes. Here, we show that the co-activator p300/CBP bound and acetylated Smad3 as well as Smad2 in vivo, and that the acetylation was stimulated by TGF-beta. A major acetylation site of Smad3 by p300/CBP is Lys-378 in the MH2 domain (Smad3C) known to be critical for the regulation of transcriptional activity. Replacement of Lys-378 with Arg decreased the transcriptional activity of GAL4-Smad3C in a luciferase assay. Moreover, p300/CBP potentiated the transcriptional activity of GAL4-Smad3C, but not the acetylation-resistant GAL4-Smad3C(K378R) mutant. These results suggest that acetylation of Smad3 by p300/CBP regulates positively its transcriptional activity.

DOI： 10.1038/sj.onc.1209826

Web of Science

Event date： 2019.9

Language：Japanese   Presentation type：Poster presentation  

Venue：横浜  

Event date： 2019.9

Language：Japanese   Presentation type：Oral presentation(general)  

Venue：横浜  

Event date： 2019.7

Language：English   Presentation type：Poster presentation  

Venue：West Palm Beach, Florida  

Event date： 2018.10

Language：English   Presentation type：Poster presentation  

Venue：Tokyo  

Event date： 2018.9

Language：Japanese   Presentation type：Oral presentation(invited, special)  

Venue：京都  

Event date： 2017.12

Language：Japanese   Presentation type：Oral presentation(general)  

Event date： 2017.12

Language：Japanese   Presentation type：Poster presentation