1
|
Luo Z, Li D, Luo X, Li L, Gu S, Yu L, Ma Y. Curcumin may serve an anticancer role in human osteosarcoma cell line U-2 OS by targeting ITPR1. Oncol Lett 2018; 15:5593-5601. [PMID: 29552196 PMCID: PMC5840671 DOI: 10.3892/ol.2018.8032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/21/2017] [Indexed: 02/03/2023] Open
Abstract
The present study aimed to determine the mechanisms of action of curcumin in osteosarcoma. Human osteosarcoma U-2 OS cells was purchased from the Cell Bank of the Chinese Academy of Sciences. RNA sequencing analysis was performed for 2 curcumin-treated samples and 2 control samples using Illumina deep sequencing technology. The differentially expressed genes were identified using Cufflink software. Enrichment and protein-protein interaction network analyses were performed separately using cluster Profiler package and Cytoscape software to identify key genes. Then, the mRNA levels of key genes were detected by quantitative reverse transcription polymerase chain reaction (RT-qPCR) in U-2 OS cells. Finally, cell apoptosis, proliferation, migration and invasion arrays were performed. In total, 201 DEGs were identified in the curcumin-treated group. EEF1A1 (degree=88), ATF7IP, HIF1A, SMAD7, CLTC, MCM10, ITPR1, ADAM15, WWP2 and ATP5C1, which were enriched in 'biological process', exhibited higher degrees than other genes in the PPI network. RT-qPCR demonstrated that treatment with curcumin was able to significantly increase the levels of CLTC and ITPR1 mRNA in curcumin-treated cells compared with control. In addition, targeting ITPR1 with curcumin significantly promoted apoptosis and suppressed proliferation, migration and invasion. Targeting ITPR1 via curcumin may serve an anticancer role by mediating apoptosis, proliferation, migration and invasion in U-2 OS cells.
Collapse
Affiliation(s)
- Zhanpeng Luo
- Graduate School, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.,Department of Orthopedics, The 309th Hospital of Chinese PLA, Beijing 100091, P.R. China
| | - Dawei Li
- Graduate School, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.,Department of Orthopedics, The 309th Hospital of Chinese PLA, Beijing 100091, P.R. China
| | - Xiaobo Luo
- Department of Orthopedics, The 309th Hospital of Chinese PLA, Beijing 100091, P.R. China
| | - Litao Li
- Department of Orthopedics, The 309th Hospital of Chinese PLA, Beijing 100091, P.R. China
| | - Suxi Gu
- Department of Orthopedics, The 309th Hospital of Chinese PLA, Beijing 100091, P.R. China
| | - Long Yu
- Department of Orthopedics, The 309th Hospital of Chinese PLA, Beijing 100091, P.R. China
| | - Yuanzheng Ma
- Graduate School, Southern Medical University, Guangzhou, Guangdong 510515, P.R. China.,Department of Orthopedics, The 309th Hospital of Chinese PLA, Beijing 100091, P.R. China
| |
Collapse
|
2
|
Abstract
Intracellular free Ca(2+) ([Ca(2+)]i) is a highly versatile second messenger that regulates a wide range of functions in every type of cell and tissue. To achieve this versatility, the Ca(2+) signaling system operates in a variety of ways to regulate cellular processes that function over a wide dynamic range. This is particularly well exemplified for Ca(2+) signals in the liver, which modulate diverse and specialized functions such as bile secretion, glucose metabolism, cell proliferation, and apoptosis. These Ca(2+) signals are organized to control distinct cellular processes through tight spatial and temporal coordination of [Ca(2+)]i signals, both within and between cells. This article will review the machinery responsible for the formation of Ca(2+) signals in the liver, the types of subcellular, cellular, and intercellular signals that occur, the physiological role of Ca(2+) signaling in the liver, and the role of Ca(2+) signaling in liver disease.
Collapse
Affiliation(s)
- Maria Jimena Amaya
- Section of Digestive Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | | |
Collapse
|
3
|
Wogonoside induces cell cycle arrest and differentiation by affecting expression and subcellular localization of PLSCR1 in AML cells. Blood 2013; 121:3682-91. [DOI: 10.1182/blood-2012-11-466219] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Key Points
Wogonoside induces cell cycle arrest and differentiation. Wogonoside acts by changing PLSCR1 expression and subcellular localization in the nucleus and by PLSCR1-related molecular events.
Collapse
|
4
|
Verma G, Bhatia H, Datta M. JNK1/2 regulates ER-mitochondrial Ca2+ cross-talk during IL-1β-mediated cell death in RINm5F and human primary β-cells. Mol Biol Cell 2013; 24:2058-71. [PMID: 23615449 PMCID: PMC3681707 DOI: 10.1091/mbc.e12-12-0885] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Elevated interleukin-1β (IL-1β) induces apoptosis in pancreatic β-cells through endoplasmic reticulum (ER) stress induction and subsequent c-jun-N-terminal kinase 1/2 (JNK1/2) activation. In earlier work we showed that JNK1/2 activation is initiated before ER stress and apoptotic induction in response to IL-1β. However, the detailed regulatory mechanisms are not completely understood. Because the ER is the organelle responsible for Ca(2+) handling and storage, here we examine the effects of IL-1β on cellular Ca(2+) movement and mitochondrial dysfunction and evaluate the role of JNK1/2. Our results show that in RINm5F cells and human primary β-cells, IL-1β alters mitochondrial membrane potential, mitochondrial permeability transition pore opening, ATP content, and reactive oxygen species production and these alterations are preceded by ER Ca(2+) release via IP3R channels and mitochondrial Ca(2+) uptake. All these events are prevented by JNK1/2 small interfering RNA (siRNA), indicating the mediating role of JNK1/2 in IL-1β-induced cellular alteration. This is accompanied by IL-1β-induced apoptosis, which is prevented by JNK1/2 siRNA and the IP3R inhibitor xestospongin C. This suggests a regulatory role of JNK1/2 in modulating the ER-mitochondrial-Ca(2+) axis by IL-1β in apoptotic cell death.
Collapse
Affiliation(s)
- Gaurav Verma
- CSIR-Institute of Genomics and Integrative Biology, Mall Road, Delhi 110 007, India
| | | | | |
Collapse
|
5
|
Blair HC, Robinson LJ, Huang CLH, Sun L, Friedman PA, Schlesinger PH, Zaidi M. Calcium and bone disease. Biofactors 2011; 37:159-67. [PMID: 21674636 PMCID: PMC3608212 DOI: 10.1002/biof.143] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 12/18/2010] [Indexed: 11/12/2022]
Abstract
Calcium transport and calcium signaling are of basic importance in bone cells. Bone is the major store of calcium and a key regulatory organ for calcium homeostasis. Bone, in major part, responds to calcium-dependent signals from the parathyroids and via vitamin D metabolites, although bone retains direct response to extracellular calcium if parathyroid regulation is lost. Improved understanding of calcium transporters and calcium-regulated cellular processes has resulted from analysis of genetic defects, including several defects with low or high bone mass. Osteoblasts deposit calcium by mechanisms including phosphate and calcium transport with alkalinization to absorb acid created by mineral deposition; cartilage calcium mineralization occurs by passive diffusion and phosphate production. Calcium mobilization by osteoclasts is mediated by acid secretion. Both bone forming and bone resorbing cells use calcium signals as regulators of differentiation and activity. This has been studied in more detail in osteoclasts, where both osteoclast differentiation and motility are regulated by calcium.
Collapse
Affiliation(s)
- Harry C Blair
- Department of Pathology, University of Pittsburgh, Veterans Affairs Health System, PA, USA.
| | | | | | | | | | | | | |
Collapse
|
6
|
Bradford PG, Gerace KV, Roland RL, Chrzan BG. Estrogen regulation of apoptosis in osteoblasts. Physiol Behav 2009; 99:181-5. [PMID: 19426747 DOI: 10.1016/j.physbeh.2009.04.025] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2008] [Revised: 02/05/2009] [Accepted: 04/30/2009] [Indexed: 10/20/2022]
Abstract
Dysregulated apoptosis is a critical failure associated with prominent degenerative diseases including osteoporosis. In bone, estrogen deficiency has been associated with accelerated osteoblast apoptosis and susceptibility to osteoporotic fractures. Hormone therapy continues to be an effective option for preventing osteoporosis and bone fractures. Induction of apoptosis in G-292 human osteoblastic cells by exposure to etoposide or the inflammatory cytokine TNF-alpha promoted acute caspase-3/7 activity and this increased activity was inhibited by pretreatment with estradiol. Etoposide also increased the expression of a battery of apoptosis-promoting genes and this expression was also inhibited by estradiol. Among the apoptotic genes whose expression was inhibited by estradiol was ITPR1, which encodes the type 1 InsP3R. InsP3Rs are intracellular calcium channels and key proapoptotic mediators. Estradiol via estrogen receptor beta1 suppresses ITPR1 gene transcription in G-292 cells. These analyses suggest that an underlying basis of the beneficial activity of estrogens in combating osteoporosis may involve the prevention of apoptosis in osteoblasts and that a key event in this process is the repression of apoptotic gene expression and inhibition of caspase-3/7.
Collapse
Affiliation(s)
- Peter G Bradford
- Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, NY 14214-3000, USA.
| | | | | | | |
Collapse
|
7
|
Bone biology and physiology: implications for novel osteoblastic osteosarcoma treatments? Med Hypotheses 2007; 70:281-6. [PMID: 17683874 DOI: 10.1016/j.mehy.2007.06.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Accepted: 06/19/2007] [Indexed: 10/23/2022]
Abstract
Healthy bone undergoes a continuous cycle of bone resorption by osteoclasts and formation by osteoblasts. These processes are in turn regulated by developmental sequences involved in differentiation of bone marrow puripotent mesenchymal cells into osteoblasts and mononuclear hemaotpoitic stem cells into osteoclasts. A variety of growth factors and receptors are involved in these maturation sequences. Osteoblast proliferation and inhibition, for example, are highly dependent not only on such factors as bone morphogenic protein and core binding factor a1 (CBFa1), but on intracellular levels of calcium and cAMP. Therefore, agents that affect concentrations of these two compounds may hypothetically play a role in osteoblastic osteosarcoma treatment. Osteoblast proliferation is also under neural control; in particular, the activity of the N-methyl-d-aspartate (NMDA) and alpha adrenergic 1 receptors. Antagonists to these receptors may also hypothetically play a role in osteoblastic osteosarcoma therapy. This article reviews the basic science supporting the putative roles of common, relatively safe but disparate agents-ranging from caffeine and theophylline to dextromethorphan and econazole-in the potential treatment of osteoblastic osteosarcoma.
Collapse
|
8
|
Chrzan BG, Bradford PG. Phytoestrogens activate estrogen receptor β1 and estrogenic responses in human breast and bone cancer cell lines. Mol Nutr Food Res 2007; 51:171-7. [PMID: 17266178 DOI: 10.1002/mnfr.200600091] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Plant-derived phytoestrogens and estrogens in hormone replacement therapies have overlapping yet sometimes divergent effects on the incidence of breast cancer and osteoporosis. Using human MCF-7 breast carcinoma and G-292 osteosarcoma cell lines, it was investigated whether the phytoestrogens genistein and daidzein affect reporter gene transcription via the estrogen receptors (ERs) ERalpha and ERbeta1 as well as whether they affect the expression of estrogen-responsive genes in MCF-7 cells and the secretion of the cytokine IL-6 from G-292 cells. The results showed that genistein and daidzein potently trigger transactivation with ERbeta1 from estrogen response element-reporter genes (EC50s of 1.7-16 nM) although they were 400- to 600-fold less potent than 17beta-estradiol (E2) (EC50 of 0.02-0.04 nM). E2 was the only potent activator of ERalpha (EC50 of 0.1-0.4 nM). The rank order potency (E2 > genistein > daidzein) is maintained in MCF-7 cells as well as G-292 cells with both receptor subtypes, with a strong receptor selectivity of the phytoestrogens for ERbeta1 over ERalpha. Genistein and daidzein increased the expression of estrogen-responsive genes in MCF-7 cells. Daidzein, like E2, inhibited IL-1beta- and hormone-mediated IL-6 secretion from G-292 cells. The results provide a basis for understanding how dietary phytoestrogens protect bone without increasing the risks for breast cancer.
Collapse
Affiliation(s)
- Brian G Chrzan
- Department of Oral Biology, State University of New York at Buffalo, Buffalo, NY 14214-3000, USA
| | | |
Collapse
|
9
|
Abstract
Calcium transport and calcium signalling mechanisms in bone cells have, in many cases, been discovered by study of diseases with disordered bone metabolism. Calcium matrix deposition is driven primarily by phosphate production, and disorders in bone deposition include abnormalities in membrane phosphate transport such as in chondrocalcinosis, and defects in phosphate-producing enzymes such as in hypophosphatasia. Matrix removal is driven by acidification, which dissolves the mineral. Disorders in calcium removal from bone matrix by osteoclasts cause osteopetrosis. On the other hand, although bone is central to management of extracellular calcium, bone is not a major calcium sensing organ, although calcium sensing proteins are expressed in both osteoblasts and osteoclasts. Intracellular calcium signals are involved in secondary control including cellular motility and survival, but the relationship of these findings to specific diseases is not clear. Intracellular calcium signals may regulate the balance of cell survival versus proliferation or anabolic functional response as part of signalling cascades that integrate the response to primary signals via cell stretch, estrogen, tyrosine kinase, and tumor necrosis factor receptors.
Collapse
Affiliation(s)
- H C Blair
- Department of Pathology, University of Pittsburgh, PA 15261, USA
| | | | | | | |
Collapse
|
10
|
Zhu G, Okada M, Yoshida S, Mori F, Ueno S, Wakabayashi K, Kaneko S. Effects of interleukin-1beta on hippocampal glutamate and GABA releases associated with Ca2+-induced Ca2+ releasing systems. Epilepsy Res 2006; 71:107-16. [PMID: 16806825 DOI: 10.1016/j.eplepsyres.2006.05.017] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2006] [Revised: 05/21/2006] [Accepted: 05/22/2006] [Indexed: 01/16/2023]
Abstract
Recent clinical and basic studies have demonstrated that hyperactivation of interleukin-1beta (IL-1beta) plays important roles in generation of febrile and epileptic seizures. To clarify this mechanism, the present study determined the effects of IL-1beta on Ca2+-associated releases of glutamate and GABA in mouse hippocampus. Both basal and K+-evoked GABA releases were regulated by Ca2+ influx and Ca2+-induced Ca2+ releasing system (CICR). The K+-evoked glutamate release was also regulated by Ca2+ influx and CICR, whereas basal glutamate release was not affected by them. IL-1beta increased basal releases of glutamate and GABA depending on the activation of Ca2+ influx and ryanodine receptor (RyR)-sensitive CICR, but reduced K+-evoked releases depending on Ca2+ influx, RyR-sensitive and inositol 1,4,5-trisphosphate receptor (IP3R)-sensitive CICRs. During neuronal hyperexcitability, the effect of IL-1beta on GABA release was more predominantly modulated by Ca2+ influx and RyR-sensitive CICR than that on glutamate. These results indicate that hyperactivation of IL-1beta leads to imbalance between glutamatergic and GABAergic transmission via toxic overload response of Ca2+ influx and CICR.
Collapse
Affiliation(s)
- Gang Zhu
- Department of Neuropsychiatry, Hirosaki University School of Medicine, Hirosaki 036-8562, Japan
| | | | | | | | | | | | | |
Collapse
|
11
|
Zhu G, Okada M, Yoshida S, Mori F, Hirose S, Wakabayashi K, Kaneko S. Involvement of Ca(2+)-induced Ca2+ releasing system in interleukin-1beta-associated adenosine release. Eur J Pharmacol 2006; 532:246-52. [PMID: 16487508 DOI: 10.1016/j.ejphar.2005.12.085] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 11/24/2005] [Accepted: 12/19/2005] [Indexed: 11/16/2022]
Abstract
Interleukin-1beta (IL-1beta) plays an important role in neuroprotective and neurodegenerative events in the central nervous system. To clarify the mechanism of controversial actions of IL-1beta, we determined the effect of IL-1beta, as well as the interaction between IL-1beta and Ca(2+)-induced Ca2+ releasing system (CICR), on adenosine releases in mice hippocampus using mini-slices method. Basal and K(+)-stimulated adenosine releases were regulated by two types of CICRs, including inositol-1,4,5-trisphosphate (IP3) receptor and ryanodine receptor. Lower concentration of IL-1beta increased both adenosine releases, whereas higher concentration did not affect their releases. The stimulatory effect of IL-1beta on basal adenosine release was reduced by removal of extracellular Ca2+ and IP3 receptor inhibitor, while the stimulatory effect of IL-1beta on K(+)-stimulated adenosine release was reduced by ryanodine receptor inhibitor. These results suggest that the potent effect of IL-1beta upon adenosine release might contribute to the neuroprotective action of IL-1beta, whereas IL-1beta-induced neurodegeneration might be due to the overload response of Ca2+ mobilization and the inactivation of adenosine exocytosis.
Collapse
Affiliation(s)
- Gang Zhu
- Department of Neuropsychiatry, Hirosaki University School of Medicine, Hirosaki 036-8562, Japan
| | | | | | | | | | | | | |
Collapse
|
12
|
Zhou Q, Ben-Efraim I, Bigcas JL, Junqueira D, Wiedmer T, Sims PJ. Phospholipid Scramblase 1 Binds to the Promoter Region of the Inositol 1,4,5-Triphosphate Receptor Type 1 Gene to Enhance Its Expression. J Biol Chem 2005; 280:35062-8. [PMID: 16091359 DOI: 10.1074/jbc.m504821200] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phospholipid scramblase 1 (PLSCR1) is a multiply palmitoylated, endofacial membrane protein originally identified based on its capacity to promote accelerated transbilayer phospholipid movement in response to Ca(2+). Recent evidence suggests that this protein also participates in cell response to various growth factors and cytokines, influencing myeloid differentiation, tumor growth, and the antiviral activity of interferon. Whereas plasma membrane PLSCR1 was shown to be required for normal recruitment and activation of Src kinase by stimulated cell surface growth factor receptors, PLSCR1 was also found to traffic into the nucleus and to tightly bind to genomic DNA, suggesting a possible additional nuclear function. We now report evidence that PLSCR1 directly binds to the 5'-promoter region of the inositol 1,4,5-triphosphate receptor type 1 gene (IP3R1) to enhance expression of the receptor. Probing a CpG island genomic library with PLSCR1 as bait identified four clones with avidity for PLSCR1, including a 191-bp fragment of the IP3R1 promoter. Using electrophoretic mobility shift and transcription reporter assays, the PLSCR1-binding site in IP3R1 was mapped to residues (-101)GTAACCATGTGGA(-89), and the segment spanning Met(86)-Glu(118) in PLSCR1 was identified to mediate its transcriptional activity. The significance of this interaction between PLSCR1 and IP3R1 in situ was confirmed by comparing levels of IP3R1 mRNA and protein in matched cells that either expressed or were deficient in PLSCR1. These data suggest that in addition to its role at the plasma membrane, effects of PLSCR1 on cell proliferative and maturational responses may also relate to alterations in expression of cellular IP3 receptors.
Collapse
MESH Headings
- Animals
- Antiviral Agents/pharmacology
- Base Sequence
- Binding Sites
- Blotting, Northern
- Blotting, Western
- Calcium/metabolism
- Calcium Channels/genetics
- Calcium Channels/metabolism
- Cell Membrane/metabolism
- Cell Nucleus/metabolism
- Cell Proliferation
- Cells, Cultured
- Cloning, Molecular
- CpG Islands
- DNA, Complementary/metabolism
- Fibroblasts/metabolism
- Gene Deletion
- Gene Expression Regulation, Enzymologic
- Glutathione Transferase/metabolism
- Humans
- Inositol 1,4,5-Trisphosphate Receptors
- Membrane Glycoproteins/genetics
- Mice
- Molecular Sequence Data
- Phospholipid Transfer Proteins/metabolism
- Phospholipids/metabolism
- Promoter Regions, Genetic
- Protein Binding
- Protein Structure, Tertiary
- RNA, Messenger/metabolism
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Transcription, Genetic
- Transcriptional Activation
- Transfection
- src-Family Kinases/metabolism
Collapse
Affiliation(s)
- Quansheng Zhou
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | | | | | | | | | | |
Collapse
|
13
|
Kirkwood K, Martin T, Andreadis ST, Kim YJ. Chemically modified tetracyclines selectively inhibit IL-6 expression in osteoblasts by decreasing mRNA stability. Biochem Pharmacol 2003; 66:1809-19. [PMID: 14563491 DOI: 10.1016/s0006-2952(03)00450-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In bone biology, interleukin (IL)-6 is an autocrine/paracrine cytokine which can induce osteoclasts formation and activation to help mediate inflammatory bone destruction. Previous studies have shown that tetracycline and its derivatives have potentially beneficial therapeutic effects in the prevention and treatment of metabolic bone diseases by modulating osteoblast and osteoclast activities. Our previous studies indicated that non-antimicrobial chemically modified tetracyclines (CMTs) can dose-dependently inhibit IL-1 beta-induced IL-6 secretion in osteoblastic cells. In the present study, we explored the molecular mechanisms underlying the ability of doxycycline analogs CMT-8 and its non-chelating pyrazole derivative, CMT-5 to affect IL-6 gene expression in murine osteoblasts. Steady-state IL-6 mRNA was decreased with CMT-8 (ca. 50%) but not by CMT-5 when stimulated by IL-1 beta. CMT-8 regulation of IL-1 beta-induced IL-6 gene expression was further explored. CMT-8 did not affect IL-6 promoter activity in reporter gene assays. However, the IL-6 mRNA stability was decreased in the presence of CMT-8. These effects require de novo protein synthesis as they were inhibited by cycloheximide. Western blot analysis indicated that CMT-8 did not affect p38 mitogen-activated protein kinase, c-jun NH(2)-terminal kinases, or extracellular signal-regulated kinases (1 and 2) phosphorylation in response to IL-1 beta. These data suggest that CMT-8 can modulate inhibit IL-1 beta-induced IL-6 expression in MC3T3-E1 cells at the post-transcriptional level affecting IL-6 mRNA stability. These observations may offer a novel molecular basis for this treatment of metabolic bone diseases that are mediated by IL-6.
Collapse
Affiliation(s)
- Keith Kirkwood
- Department of Periodontics and Endodontics, State University of New York at Buffalo, 250 Squire Hall, 3435 Main Street, Buffalo, NY 14214-3008, USA.
| | | | | | | |
Collapse
|
14
|
Shibao K, Hirata K, Robert ME, Nathanson MH. Loss of inositol 1,4,5-trisphosphate receptors from bile duct epithelia is a common event in cholestasis. Gastroenterology 2003; 125:1175-87. [PMID: 14517800 PMCID: PMC2831084 DOI: 10.1016/s0016-5085(03)01201-0] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Cholestasis is one of the principal manifestations of liver disease and often results from disorders involving bile duct epithelia rather than hepatocytes. A range of disorders affects biliary epithelia, and no unifying pathophysiologic event in these cells has been identified as the cause of cholestasis. Here we examined the role of the inositol 1,4,5-trisphosphate receptor (InsP3R)/Ca(2+) release channel in Ca(2+) signaling and ductular secretion in animal models of cholestasis and in patients with cholestatic disorders. METHODS The expression and distribution of the InsP3R and related proteins were examined in rat cholangiocytes before and after bile duct ligation or treatment with endotoxin. Ca(2+) signaling was examined in isolated bile ducts from these animals, whereas ductular bicarbonate secretion was examined in isolated perfused livers. Confocal immunofluorescence was used to examine cholangiocyte InsP3R expression in human liver biopsy specimens. RESULTS Expression of the InsP3R was selectively lost from biliary epithelia after bile duct ligation or endotoxin treatment. As a result, Ca(2+) signaling and Ca(2+)-mediated bicarbonate secretion were lost as well, although other components of the Ca(2+) signaling pathway and adenosine 3',5'-cyclic monophosphate (cAMP)-mediated bicarbonate secretion both were preserved. Examination of human liver biopsy specimens showed that InsP3Rs also were lost from bile duct epithelia in a range of human cholestatic disorders, although InsP3R expression was intact in noncholestatic liver disease. CONCLUSIONS InsP3-mediated Ca(2+) signaling in bile duct epithelia appears to be important for normal bile secretion in the liver, and loss of InsP3Rs may be a final common pathway for cholestasis.
Collapse
Affiliation(s)
- Kazunori Shibao
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8019, USA
| | | | | | | |
Collapse
|