bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hyperthermia engages the intrinsic apoptotic pathway by enhancing upstream caspase activation to overcome apoptotic resistance in MCF‐7 breast adenocarcinoma cells
Authors: Klostergaard J. , Leroux M.E. , Auzenne E. , Khodadadian M. , Spohn W. , Wu J.Y. , Donato N.J. 
Published: January 2006

AbstractFebrile hyperthermia enhanced TNF‐stimulated apoptosis of MCF‐7 cells and overcame resistance in a TNF‐resistant, MCF‐7 variant (3E9), increasing their TNF‐sensitivity by 10‐ and 100‐fold, respectively. In either cell line, the hyperthermic potentiation was attributable to increased apoptosis that was totally quenched by caspase inhibition. In MCF‐7 cells, hyperthermic potentiation of apoptosis was associated with sustained activation of upstream caspases in response to TNF and more prominent engagement of the intrinsic apoptotic pathway. Apoptotic enhancement by hyperthermia was primarily mediated by caspase‐8 activation, as the specific inhibitor, Z‐IETD, blocked cell death, whereas direct engagement of the intrinsic apoptotic pathway (with doxorubicin) was not affected. In 3E9 cells, hyperthermia alone induced activation of caspase‐8, and was further enhanced by TNF. In 3E9 cells, hyperthermia caused TNF‐dependent loss of mitochondrial membrane potential and activation of capspase‐9 that was initiated and dependent on upstream caspases. MCF‐7 and 3E9 cells were equally sensitive to exogenous C6‐ceramide, but mass spectroscopic analysis of ceramide species indicated that total ceramide content was not enhanced by TNF and/or hyperthermia treatment, and that the combination of TNF and hyperthermia caused only modest elevation of one species (dihydro‐palmitoyl ceramide). We conclude that febrile hyperthermia potentiates apoptosis of MCF‐7 cells and overcomes TNF‐resistance by sustained activation of caspase‐8 and engagement of the intrinsic pathway that is independent of ceramide flux. This report provides the first evidence for regulation of caspase‐dependent apoptosis by febrile hyperthermia. J. Cell. Biochem. 98: 356–369, 2006. © 2006 Wiley‐Liss, Inc.
Probing membrane proteins using atomic force microscopy
Authors: Li Guangyong , Xi Ning , Wang Donna H. 
Published: January 2006

AbstractTo gain insights into how biological molecules function, advanced technologies enabling imaging, sensing, and actuating single molecules are required. The atomic force microscope (AFM) would be one of novel potential tools for these tasks. In this study, techniques and efforts using AFM to probe biomolecules are introduced and reviewed. The state‐of‐art techniques for characterizing specific single receptor using the functionalized AFM tip are discussed. An example of studying the angiotensin II type 1 (AT1) receptors expressed in sensory neuronal cells by AFM with a functionalized tip is given. Perspectives for identifying and characterizing specific individual membrane proteins using AFM in living cells are provided. Given that many diseases have their roots at the molecular scale and are best understood as a malfunctioning biological nanomachines, the prospects of these unique techniques in basic biomedical research or in clinical practice are beyond our imagination. J. Cell. Biochem. 97: 1191–1197, 2006. © 2006 Wiley‐Liss, Inc.
Fibroblast extracellular matrix gene expression in response to keratinocyte‐releasable stratifin
Authors: Ghaffari Abdi , Li Yunyaun , Karami Ali , Ghaffari Mazyar , Tredget Edward E. , Ghahary Aziz 
Published: January 2006

AbstractTermination of wound‐healing process requires a fine balance between connective tissue deposition and its hydrolysis. Previously, we have demonstrated that keratinocyte‐releasable stratifin, also known as 14‐3‐3 σ protein, stimulates collagenase (MMP‐1) expression in dermal fibroblasts. However, role of extracellular stratifin in regulation of extracellular matrix (ECM) factors and other matrix metalloproteinases (MMPs) in dermal fibroblast remains unexplored. To address this question, large‐scale ECM gene expression profile were analyzed in human dermal fibroblasts co‐cultured with keratinocytes or treated with recombinant stratifin. Superarray pathway‐specific microarrays were utilized to identify upregulation or downregulation of 96 human ECM and adhesion molecule genes. RT‐PCR and Western blot were used to validate microarray expression profiles of selected genes. Comparison of gene profiles with the appropriate controls showed a significant (more than twofold) increase in expression of collagenase‐1, stromelysin‐1 and ‐2, neutrophil collagenase, and membrane type 5 MMP in dermal fibroblasts treated with stratifin or co‐cultured with keratinocytes. Expression of type I collagen and fibronectin genes decreased in the same fibroblasts. The results of a dose–response experiment showed that stratifin stimulates the expression of stromelysin‐1 (MMP‐3) mRNA by dermal fibroblasts in a concentration‐dependent fashion. Furthermore, Western blot analysis of fibroblast‐conditioned medium showed a peak in MMP‐3 protein levels 48 h following treatment with recombinant stratifin. In a lasting‐effect study, MMP‐3 protein was detected in fibroblast‐condition medium for up to 72 h post removal of stratifin. In conclusion, our results suggest that keratinocyte‐releasable stratifin plays a major role in induction of ECM degradation by dermal fibroblasts through stimulation of key MMPs, such as MMP‐1 and MMP‐3. Therefore, stratifin protein may prove to be a useful target for clinical intervention in controlling excessive wound healing in fibrotic conditions. J. Cell. Biochem. 98: 383–393, 2006. © 2006 Wiley‐Liss, Inc.
Prostanoid pattern and iNOS expression during chondrogenic differentiation of human mesenchymal stem cells
Authors: Mais Anna , Klein Thomas , Ullrich Volker , Schudt Christian , Lauer Gereon 
Published: January 2006

AbstractAvailability of human chondrocytes is a major limiting factor regarding drug discovery projects and tissue replacement therapies. As an alternative human mesenchymal stem cells (hMSCs) from bone marrow are taken into consideration as they can differentiate along the chondrogenic lineage. However, it remains to be shown whether they could form a valid model for primary chondrocytes with regards to inflammatory mediator production, like nitric oxide (NO) and prostanoids. We therefore investigated the production of NO and prostanoids in hMSCs over the course of chondrogenic differentiation and in response to IL‐1β using primary OA chondrocytes as reference. Chondrogenic differentiation was monitored over 28 days using collagen I, collagen II, and collagen X expression levels. Expression levels of inducible nitric oxide synthase (iNOS), levels of NO, and prostanoids were assessed using PCR, Griess assay, and GC/MS/MS, respectively. The hMSCs collagen expression profile during course of differentiation was consistent with a chondrocytic phenotype. Contrary to undifferentiated cells, differentiated hMSCs expressed iNOS and produced NO following stimulation with IL‐1β. Moreover, this induction of iNOS expression was corticosteroid insensitive. The spectrum of prostanoid production in differentiated hMSCs showed similarities to that of OA chondrocytes, with PGE2 as predominant product. We provide the first detailed characterization of NO and prostanoid production in hMSCs in the course of chondrogenic differentiation. Our results suggest that differentiated hMSCs form a valid model for chondrocytes concerning inflammatory mediator production. Furthermore, we propose that IL‐1β stimulation, leading to corticosteroid‐insensitive NO synthesis, can be used as a sensitive marker of chondrogenesis. J. Cell. Biochem. 98: 798–809, 2006. © 2006 Wiley‐Liss, Inc.
1α,25‐dihydroxyvitamin D3‐mediated stimulation of steroid sulphatase activity in myeloid leukaemic cell lines requires VDRnuc‐mediated activation of the RAS/RAF/ERK‐MAP kinase signalling pathway
Authors: Hughes Philip J. , Brown Geoffrey 
Published: January 2006

Abstract1α,25‐dihydroxyvitamin D3 (1α,25(OH)2D3) stimulates the activity of steroid sulphatase (STS) in myeloid cells [Hughes et al., 2001, 2005]. This was attenuated by inhibitors of phospholipase D (PLD) (n‐butanol, 2,3‐diphosphoglyceric acid, C2‐ceramide) and phosphatidate phosphohydrolase (PAP) (propranolol and chlorpromazine), but was unaffected by inhibitors of phospholipase C. The 1α,25(OH)2D3‐induced STS activity was also attenuated by inhibitors of protein kinase Cα and protein kinase Cδ (Go 6976, HBDDE and rottlerin), but not by an inhibitor of protein kinase Cβ (LY379196). Additionally, 1α,25(OH)2D3‐induced STS activity was attenuated by inhibitors of RAS (manumycin A), RAF (GW5074), MEK (PD098059 and U1026) and JNK (SP600125), but not p38 (PD169316). 1α,25(OH)2D3 produced a rapid and long lasting stimulation of the ERK‐MAP kinase signalling cascade in HL60 myeloid leukaemic cells. This ‘non‐genomic’ effect of 1α,25(OH)2D3 blocked by pharmacological antagonists of nuclear vitamin D receptors (VDRnuc) and does not appear to require hetero‐dimerisation with the retinoid‐X receptor (RXR). Inhibitors of the Src tyrosine kinase (PP1), RAS (manumycin A), RAS–RAF interactions (sulindac sulphide and RAS inhibitory peptide), RAF (GW5074 or chloroquine), and protein kinase Cα (HBDDE) abrogated the 1α,25(OH)2D3‐stimulated increase in ERK‐MAP kinase activity. Taken together, these results show that 1α,25(OH)2D3/VDRnuc activation of the RAS/RAF/ERK‐MAP kinase signalling pathway plays an important role in augmenting STS activity in human myeloid leukaemic cell lines. J. Cell. Biochem. 98: 590–617, 2006. � 2006 Wiley‐Liss, Inc.
Lysyl oxidase regulates actin filament formation through the p130Cas/Crk/DOCK180 signaling complex
Authors: Payne Stacey L. , Hendrix Mary J.C. , Kirschmann Dawn A. 
Published: January 2006

AbstractWe have previously demonstrated that lysyl oxidase (LOX) is expressed in invasive breast cancer cells compared to poorly invasive cells. Additionally, we have recently shown that LOX regulates cell migration, a key step in the invasion process, through a hydrogen peroxide‐dependent mechanism involving the focal adhesion kinase (FAK)/Src signaling complex. Here we further elucidate the role of LOX in cell motility/migration by examining the role of LOX in actin filament polymerization. We demonstrate that inhibition of LOX leads to an increase in phalloidin staining, directly associated with an increase in actin stress fiber formation. This increase in staining was confirmed by activity assays showing an increase in Rho activity with decreased LOX activity. Additionally, Rac and Cdc42 activity decreased with the reduction in LOX activity. Taken together, these data demonstrate a loss of a motogenic phenotype with decreased LOX activity. Finally, in order to elucidate the mechanism by which LOX regulates actin polymerization, we have demonstrated that LOX facilitates p130Cas phosphorylation, which allows for the binding to CAS related kinase (Crk) and formation of the p130Cas/Crk/DOCK180 signaling complex. Formation of this complex leads to an increase in Rac‐GTP, which decreases actin stress fiber formation and increases formation of lamellipodium. These data demonstrate that LOX regulates cell motility/migration through changes in actin filament polymerization, which involve the regulation of the p130Cas/Crk/DOCK180 signaling pathway. Elucidating the role of LOX in the regulation of cell motility will allow the development of more effective therapeutic strategies to treat invasive/metastatic breast cancer. J. Cell. Biochem. 98: 827–837, 2006. © 2006 Wiley‐Liss, Inc.
Salvianolic acid B attenuates cyclooxygenase‐2 expression in vitro in LPS‐treated human aortic smooth muscle cells and in vivo in the apolipoprotein‐E‐deficient mouse aorta
Authors: Chen Yuh‐Lien , Hu Cing‐Siang , Lin Feng‐Yen , Chen Yung‐Hsiang , Sheu Li‐Min , Ku Hung‐Hai , Shiao Ming‐Shi , Chen Jaw‐Wen , Lin Shing‐Jong 
Published: January 2006

AbstractInflammation plays an essential role in atherosclerosis and post‐angioplasty restenosis and the synthesis and release of inflammatory cytokines from vascular smooth muscle cells is an important contributor to these pathologies. It is assumed that drugs that prevent the overproduction of inflammatory cytokines may inhibit cardiovascular disorders. In the present study, the effects of a water‐soluble antioxidant, salvianolic acid B (Sal B), derived from a Chinese herb, on the expression of cyclooxygenase (COX) in lipopolysaccharide (LPS)‐treated human aortic smooth muscle cells (HASMCs) and in the aortas of cholesterol‐fed apoE deficient mice were investigated. In unstimulated HASMCs, COX‐2 mRNA and protein were almost undetectable, but were strongly upregulated in response to LPS. In contrast, HASMCs with or without LPS treatment showed constitutive expression of COX‐1 mRNA and protein. The activation of COX‐2 protein synthesis in LPS‐stimulated HASMCs was shown to involve the activation of the extracellular‐signal‐regulated kinase 1/2 (ERK1/2), c‐Jun NH2‐terminal kinase (JNK), and p38 mitogen‐activated protein kinase pathway. Incubation of HASMCs with Sal B before LPS stimulation resulted in pronounced downregulation of COX‐2 expression. Sal B treatment suppressed ERK1/2 and JNK phosphorylation and attenuated the increase in prostaglandin E2 production and NADPH oxidase activity in LPS‐treated HASMCs. When apoE‐deficient mice were fed a 0.15% cholesterol diet with or without supplementation with 0.3% Sal B for 12 weeks, the intima/media area ratio in the thoracic aortas was significantly reduced in the Sal B group (0.010 ± 0.009%) compared to the apoE‐deficient group (0.114 ± 0.043%) and there was a significant reduction in COX‐2 protein expression in the thickened intima. These results demonstrate that Sal B has anti‐inflammatory properties and may explain its anti‐atherosclerotic properties. This new mechanism of action of Sal B, in addition to its previously reported inhibition of LDL oxidation, may help explain its efficacy in the treatment of atherosclerosis. J. Cell. Biochem. 98: 618–631, 2006. © 2006 Wiley‐Liss, Inc.
Engineered nanoparticles as precise drug delivery systems
Authors: Yih T.C. , Al‐Fandi M. 
Published: January 2006

AbstractWith the remarkable development of nanotechnology in recent years, new drug delivery approaches based on the state‐of‐the‐art nanotechnology have been receiving significant attention. Nanoparticles, an evolvement of nanotechnology, are increasingly considered as a potential candidate to carry therapeutic agents safely into a targeted compartment in an organ, particular tissue or cell. These particles are colloidal structures with a diameter smaller than 1,000 nm, and therefore can penetrate through diminutive capillaries into the cell's internal machinery. This innovative delivery technique might be a promising technology to meet the current challenges in drug delivery. When loaded with a gene or drug agent, nanoparticles can become nanopills, which can effectively treat problematical diseases such as cancer. This article summarizes different types of nanoparticles drug delivery systems under investigation and their prospective therapeutic applications. Also, this article presents a closer look at the advances, current challenges, and future direction of nanoparticles drug delivery systems. J. Cell. Biochem. 97: 1184–1190, 2006. © 2006 Wiley‐Liss, Inc.
Functional characterization of hNUDC as a novel accumulator that specifically acts on in vitro megakaryocytopoiesis and in vivo platelet production
Authors: Wei Ming‐Xu , Yang Yan , Ge Yi‐Chen , Xu Peilin 
Published: January 2006

AbstractHuman NUDC (hNUDC) has been previously described as a human homolog of a fungal nuclear migration protein. It is a multifunctional interactive protein that forms an association with the microtubule motor complex in a variety of cells. Our recent studies demonstrated that hNUDC could bind specifically to the thrombopoietin receptor (Mpl) and suggest a potential role for hNUDC in megakaryocytopoiesis and thrombopoiesis. The present study is designed to define its biological activity. We demonstrate that the recombinant hNUDC significantly increases megakaryocyte maturation in serum‐free liquid‐cultured human CD34+ cells and stimulates colony formation in serum‐free semi‐solid cultures. Flow cytometry analyses also confirm the stimulatory effect of hNUDC on megakaryocyte polyploidization and in vitro platelet production. In vivo experiments further demonstrate that the administration of hNUDC substantially enhance the number of circulating platelets in normal mice. J. Cell. Biochem. 98: 429–439, 2006. © 2006 Wiley‐Liss, Inc.
LDL induces Saos2 osteoblasts death via Akt pathways responsive to a neutral sphingomyelinase inhibitor
Authors: Klein Benjamin Y. , Kerem Zohar , Rojansky Nathan 
Published: January 2006

AbstractAtherosclerosis is epidemiologically associated with postmenopausal osteoporosis (OP) presumably by common etiologic factors, reflecting a state of co‐morbidity in aging. Osteoblasts make a significant facet of this co‐morbidity state. Since oxidized low‐density lipoprotein (oxLDL) is a major factor in generation of vascular wall pathology, we examined the ability of native LDL (nLDL) and oxLDL to induce Saos2 osteoblasts growth arrest. OxLDL induced Saos2 cell death with morphological features of apoptosis that was inhibited mainly by caspase‐9 and partially by caspase‐3 but not by caspase‐8 inhibitors. nLDL, like oxLDL, has induced cell death, where 60% (P = 0.00033) and 30% (P = 0.075, ns) of the cell death, respectively, could be inhibited by scyphostatin (a neutral sphingomyelinase [nSMase] inhibitor). Upon similar condition, nLDL inhibited the phosphorylation of Akt and two of its downstream targets, fork head receptor (FKHR) and glycogen synthase kinase‐3 (GSK3). This is a pathway that stimulates cell survival and proliferation. nLDL has also induced an increase in the proapoptotic Bcl‐Xs and it has diminished the potential antiapoptotic Src kinase activity. At the 4 h time‐point, upon a substantial decrease in nLDL‐induced Akt phosphorylation, scyphostatin has inhibited the reduction in FKHR and GSK3 phosphorylation but inexplicably not that of Akt. Scyphostatin has also corrected the reduction in Src kinase activity. Taken together, the results indicate that nLDL has induced apoptosis in Saos2 osteoblasts by inactivation of the pathway downstream to Akt using nSMase, and by involvement of Src kinase. Inferring that caspase‐9 was the main executioner (rather than caspase‐8 and‐3) in Saos2 cell death, indicates that the nSMase‐induced release of ceramide, directly activated the intrinsic mitochondrial apoptotic pathway. With regard to the Akt inactivation by nLDL, Saos2 osteoblasts responded in an opposite fashion to the response reported by others, in macrophages. J. Cell. Biochem. 98: 661–671, 2006. © 2006 Wiley‐Liss, Inc.
CCN2, connective tissue growth factor, stimulates collagen deposition by gingival fibroblasts via module 3 and α6‐ and β1 integrins
Authors: Heng Edwin C.K. , Huang Yuanyi , Black Samuel A. , Trackman Philip C. 
Published: January 2006

AbstractCCN2, (connective tissue growth factor, CTGF) is a matricellular factor associated with fibrosis that plays an important role in the production and maintenance of fibrotic lesions. Increased collagen deposition and accumulation is a common feature of fibrotic tissues. The mechanisms by which CCN2/CTGF contributes to fibrosis are not well understood. Previous studies suggest that CTGF exerts some of its biological effects at least in part by integrin binding, though this mechanism has not been previously shown to contribute to fibrosis. Utilizing full length CCN2/CTGF, CCN2/CTGF fragments, and integrin neutralizing antibodies, we provide evidence that the effects of CCN2/CTGF to stimulate extracellular matrix deposition by gingival fibroblasts are mediated by the C‐terminal half of CCN2/CTGF, and by α6 and β1 integrins. In addition, a synthetic peptide corresponding to a region of CCN2/CTGF domain 3 that binds α6β1 inhibits the collagen‐deposition assay. These studies employed a new and relatively rapid assay for CCN2/CTGF‐stimulated collagen deposition based on Sirius Red staining of cell layers. Data obtained support a pathway in which CCN2/CTGF could bind to α6β1 integrin and stimulate collagen deposition. These findings provide new experimental methodologies applicable to uncovering the mechanism and signal transduction pathways of CCN2/CTGF‐mediated collagen deposition, and may provide insights into potential therapeutic strategies to treat gingival fibrosis and other fibrotic conditions. J. Cell. Biochem. 98: 409–420, 2006. © 2006 Wiley‐Liss, Inc.
Collagen type I selectively activates ectodomain shedding of the discoidin domain receptor 1: Involvement of Src tyrosine kinase
Authors: Slack Barbara E. , Siniaia Marina S. , Blusztajn Jan K. 
Published: January 2006

AbstractThe discoidin domain receptor 1 (DDR1) is a receptor tyrosine kinase that is highly expressed in breast carcinoma cells. Upon binding to collagen, DDR1 undergoes autophosphorylation followed by limited proteolysis to generate a tyrosine phosphorylated C‐terminal fragment (CTF). Although it was postulated that this fragment is formed as a result of shedding of the N‐terminal ectodomain, collagen‐dependent release of the DDR1 extracellular domain has not been demonstrated. We now report that, in conjunction with CTF formation, collagen type I stimulates concentration‐dependent, saturable shedding of the DDR1 ectodomain from two carcinoma cell lines, and from transfected cells. In contrast, collagen did not promote cleavage of other transmembrane proteins including the amyloid precursor protein (APP), ErbB2, and E‐cadherin. Collagen‐dependent tyrosine phosphorylation and proteolysis of DDR1 in carcinoma cells were reduced by a pharmacologic Src inhibitor. Moreover, expression of a dominant negative Src mutant protein in human embryonic kidney cells inhibited collagen‐dependent phosphorylation and shedding of co‐transfected DDR1. The hydroxamate‐based metalloproteinase inhibitor TAPI‐1 (tumor necrosis factor‐α protease inhibitor‐1), and tissue inhibitor of metalloproteinase (TIMP)‐3, also blocked collagen‐evoked DDR1 shedding, but did not reduce levels of the phosphorylated CTF. Neither shedding nor CTF formation were affected by the γ‐secretase inhibitor, L‐685,458. The results demonstrate that collagen‐evoked ectodomain cleavage of DDR1 is mediated in part by Src‐dependent activation or recruitment of a matrix‐ or disintegrin metalloproteinase, and that CTF formation can occur independently of ectodomain shedding. Delayed shedding of the DDR1 ectodomain may represent a mechanism that limits DDR1‐dependent cell adhesion and migration on collagen matrices. J. Cell. Biochem. 98: 672–684, 2006. © 2006 Wiley‐Liss, Inc.