bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immortalized mouse articular cartilage cell lines retain chondrocyte phenotype and respond to both anabolic factor BMP‐2 and pro‐inflammatory factor IL‐1
Authors: Majumdar Manas K. , Chockalingam Priya S. , Bhat Ramesh A. , Sheldon Richard , Keohan Cristin , Blanchet Tracey , Glasson Sonya , Morris Elisabeth A. 
Published: October 2007

AbstractArticular cartilage chondrocytes help in the maintenance of tissue homeostasis and function of the articular joint. Study of primary chondrocytes in culture provides information closely related to in vivo functions of these cells. Limitations in the primary culture of chondrocytes have lead to the development of cells lines that serve as good surrogate models for the study of chondrocyte biology. In this study, we report the establishment and characterization of chondrocyte cell lines, MM‐Sv/HP and MM‐Sv/HP‐2 from mouse articular cartilage. Cells were isolated from mouse femoral head articular cartilage, immortalized and maintained in culture through numerous passages. The morphology of the cells was from fibroblastic to polygonal in nature. Gene expression studies using quantitative PCR (Q‐PCR) were performed on cells in monolayer culture and cells embedded in a three‐dimensional alginate matrix. Stimulation of cells in monolayer culture with anabolic factor, BMP‐2, resulted in increased gene expression of the extracellular matrix molecules, aggrecan and type II collagen and their regulator transcription factor, Sox9. Treatment by pro‐inflammatory IL‐1 resulted in increased gene expression of catabolic effectors including Aggrecanases (ADAMTS4, ADAMTS5), MMP‐13 and nitric oxide synthase (Nos2). Cells in alginate treated with BMP‐2 resulted in increased synthesis of proteoglycan which was released into the conditioned media on IL‐1 stimulation. Western analysis of conditioned media showed the presence of Aggrecanase‐cleaved aggrecan fragments. In summary, MM‐Sv/HP and MM‐Sv/HP‐2 show preservation of important characteristics of articular chondrocytes as examined under multiple culture conditions and would provide a useful reagent in the study of chondrocyte biology. J. Cell. Physiol. 215: 68–76, 2008. © 2007 Wiley‐Liss, Inc.
Pleiotrophin induces nitric oxide dependent migration of endothelial progenitor cells
Authors: Heiss Christian , Wong Maelene L. , Block Vanessa I. , Lao David , Real Wendy May , Yeghiazarians Yerem , Lee Randall J. , Springer Matthew L. 
Published: October 2007

AbstractPleiotrophin (PTN) is produced under ischemic conditions and has been shown to induce angiogenesis in vivo. We studied whether or not PTN exerts chemotaxis of pro‐angiogenic early endothelial progenitor cells (EPCs), a population of circulating cells that have been reported to participate in and stimulate angiogenesis. Chemotaxis of EPCs, isolated from blood of healthy humans (n = 5), was measured in transwell assays. PTN at 10–500 ng/ml elicited dose‐dependent chemotaxis of both EPCs and human umbilical vein endothelial cells (HUVECs), but not of human coronary artery smooth muscle cells (CASMCs) and T98G glioblastoma cells that lack PTN receptors. The degree of chemotaxis was comparable to that induced by the angiogenic factors VEGF and SDF‐1α. Chemotaxis to PTN was blocked by the NOS inhibitors L‐NNA and L‐NMMA, the NO scavenger PTIO, the phosphoinositide‐3 kinase inhibitor wortmannin, and the guanylyl cyclase inhibitor ODQ, suggesting dependence of EPC chemotaxis on these pathways. PTN induced NOS‐dependent production of NO to a similar degree as did VEGF, as indicated by the NO indicator DAF‐2. PTN increased proliferation in EPCs and HUVECs to a similar extent as VEGF, but did not induce proliferation of CASMCs. While L‐NNA abolished PTN‐induced migration in EPCs and HUVECs, it did not inhibit PTN‐ and VEGF‐enhanced proliferation and also caused proliferation by itself. These data suggest that PTN may mediate its pro‐angiogenic effects by increasing the local number of not only endothelial cells but also early EPCs at angiogenic sites. J. Cell. Physiol. 215: 366–373, 2008. © 2007 Wiley‐Liss, Inc.
RETRACTED: Basic fibroblast growth factor accelerates matrix degradation via a neuro‐endocrine pathway in human adult articular chondrocytes
Authors: Im Hee‐Jeong , Li Xin , Muddasani Prasuna , Kim Gun‐Hee , Davis Francesca , Rangan Jayanthi , Forsyth Christopher B. , Ellman Michael , Thonar Eugene JMA 
Published: October 2007

AbstractPain‐related neuropeptides released from synovial fibroblasts, such as substance P, have been implicated in joint destruction. Substance P‐induced inflammatory processes are mediated via signaling through a G‐protein‐coupled receptor, that is, neurokinin‐1 tachykinin receptor (NK1‐R). We determined the pathophysiological link between substance P and its receptor in human adult articular cartilage homeostasis. We further examined if catabolic growth factors such as basic fibroblast growth factor (bFGF or FGF‐2) or IL‐1β accelerate matrix degradation via a neural pathway upregulation of substance P and NK1‐R. We show here that substance P stimulates the production of cartilage‐degrading enzymes, such as matrix metalloproteinase‐13 (MMP‐13), and suppresses proteoglycan deposition in human adult articular chondrocytes via NK1‐R. Furthermore, we have demonstrated that substance P negates proteoglycan stimulation promoted by bone morphogenetic protein‐7, suggesting the dual role of substance P as both a pro‐catabolic and anti‐anabolic mediator of cartilage homeostasis. We report that bFGF‐mediated stimulation of substance P and its receptor NK1‐R is, in part, through an IL‐1β‐dependent pathway. J. Cell. Physiol. 215: 452–463, 2008. © 2007 Wiley‐Liss, Inc.
Melanocytes expressing MC1R polymorphisms associated with red hair color have altered MSH‐ligand activated pigmentary responses in coculture with keratinocytes
Authors: Roberts Donald W. , Newton Richard A. , Leonard J. Helen , Sturm Richard A. 
Published: October 2007

AbstractThe occurrence of red hair and pale skin in individuals, which is associated with UV‐radiation sensitivity and increased skin cancer risk, is mainly due to polymorphisms in the melanocortin‐1 receptor (MC1R) expressed in melanocytes. We have established a serum free human melanocyte–keratinocyte coculture system to study the behavior and functional abilities of melanocytes expressing MC1R red hair color (RHC) variants in order to identify differences from their wild type (WT) counterparts. This model revealed the importance of elevated calcium levels in promoting strong melanocyte interaction with the surrounding keratinocytes and resulted in a dendritic melanocyte morphology similar to that in skin. However, the dendricity response following agonist activation of the MC1R receptor by NDP‐MSH peptide, was markedly enhanced in WT melanocytes in comparison to RHC strains. Analysis of mRNA expression and protein levels of the major pigmentation markers following NDP‐MSH treatment distinguished the enzyme dopachrome tautomerase as preferentially upregulated in cocultures of WT strains, with negligible or a much reduced response in melanocytes with RHC variant alleles. These results highlight the use of the coculture system in determining fundamental differences in the physiology of melanocytes expressing RHC MC1R receptors and those of WT genotype, which are likely to contribute to the increased skin cancer risk for individuals that carry these variants. J. Cell. Physiol. 215: 344–355, 2008. © 2007 Wiley‐Liss, Inc.
Progression elevated gene‐3 promoter (PEG‐Prom) confers cancer cell selectivity to human polynucleotide phosphorylase (hPNPaseold‐35)‐mediated growth suppression
Authors: Chan Isaac , Lebedeva Irina V. , Su Zao‐Zhong , Sarkar Devanand , Valerie Kristoffer , Fisher Paul B. 
Published: October 2007

AbstractThe poor prognosis of pancreatic cancer patients using currently available therapies mandates novel therapeutics that combine anti‐neoplastic potency with toxicity‐minimizing cancer specificity. Employing an overlapping pathway screen to identify genes exhibiting coordinated expression as a consequence of terminal cell differentiation and replicative senescence, we identified human polynucleotide phosphorylase (hPNPaseold‐35), a 3′,5′‐exoribonuclease that exhibits robust growth‐suppressing effects in a wide spectrum of human cancers. A limitation to the anti‐neoplastic efficacy of hPNPaseold‐35 relates to its lack of cancer specificity. The promoter of Progression Elevated Gene‐3 (PEG‐Prom), discovered in our laboratory via subtraction hybridization in a transformation progression rodent tumor model functions selectively in a diverse array of human cancer cells, with limited activity in normal cells. An adenovirus constructed with the PEG‐Prom driving expression of hPNPaseold‐35 containing a C‐terminal Hemaglutinin (HA)‐tag (Ad.PEG.hPNPaseold‐35) was shown to induce robust transgene expression, growth suppression, apoptosis, and cell‐cycle arrest in a broad panel of pancreatic cancer cells, with minimal effects in normal immortalized pancreatic cells. hPNPaseold‐35 expression correlated with arrest in the G2/M phase of the cell cycle and up‐regulation of the cyclin‐dependent kinase inhibitors (CDKI) p21CIP1/WAF‐1/MDA‐6 and p27KIP1. In a nude mouse xenograft model, Ad.PEG.hPNPaseold‐35 injections effectively inhibited growth of human pancreatic cancer cells in vivo. These findings support the potential efficacy of combining a cancer‐specific promoter, such as the PEG‐Prom, with a novel anti‐neoplastic agent, such as hPNPaseold‐35, to create a potent, targeted cancer therapeutic, especially for a devastating disease like pancreatic cancer. J. Cell. Physiol. 215: 401–409, 2008. © 2007 Wiley‐Liss, Inc.
Osteoblast proliferation or differentiation is regulated by relative strengths of opposing signaling pathways
Authors: Raucci Angela , Bellosta Paola , Grassi Roberta , Basilico Claudio , Mansukhani Alka 
Published: October 2007

AbstractSkeletal development requires the correct balance of osteoblast proliferation, survival, and differentiation which is modulated by a network of signaling pathways and transcription factors. We have examined the role of the AKT (PKB), and ERK1/2 signaling pathways in the osteoblast response to FGFs, which inhibit differentiation, and to IGF‐1 and Wnt signaling, which promote it. Using osteoblastic cell lines as well as primary calvarial osteoblasts, we show that ERK1/2 and AKT have distinct effects in FGF‐induced osteoblast proliferation and differentiation. ERK1/2 is a primary mediator of FGF‐induced proliferation, but also contributes to osteoblast differentiation, while AKT is important for osteoblast survival. Signaling by IGF‐1, that promotes osteoblast differentiation, strongly activates AKT and weakly ERK1/2, while the opposite results are obtained with FGF, which inhibits differentiation. By introducing a constitutively active form of AKT, we found that increased AKT activity drives osteoblasts to differentiation. Increasing the AKT signal in osteoblasts that harbor FGFR2 activating mutations, found in Crouzon (342Y) and Apert (S22W) syndromes, is also able to drive differentiation in these cells, that normally fail to differentiate. Wnt signals, that promotes differentiation, also induce AKT phosphorylation, and cells expressing active AKT have increased levels of stabilized beta‐catenin, a central molecule in Wnt signaling. Our results indicate that the relative strengths of ERK and AKT signaling pathways determine whether osteoblasts are driven into proliferation or differentiation, and that the effects of AKT may be due, in part, to synergy with the Wnt pathway as well as with the Runx2 transcription factor. J. Cell. Physiol. 215: 442–451, 2008. © 2007 Wiley‐Liss, Inc.
Identification of the gene transcription and apoptosis mediated by TGF‐β‐Smad2/3‐Smad4 signaling
Authors: Yu Jian , Zhang Liang , Chen Ailiang , Xiang Guangxin , Wang Yahui , Wu Jianping , Mitchelson Keith , Cheng Jing , Zhou Yuxiang 
Published: October 2007

AbstractTransforming growth factor‐β (TGF‐β) signaling is known to depend on the formation of Smad2/3‐Smad4 transcription regulatory complexes. However, the signaling functions of Smad2/3‐Smad4 during TGF‐β‐induced responses are obscure as TGF‐β also initiates a number of other signaling pathways. In this study, we systematically assessed the contribution of TGF‐β‐Smad2/3‐Smad4 signaling to both target gene transcription and apoptosis. Individual Smads were selectively knocked down in Hep3B cells by stable RNA interference (RNAi). We identified TGF‐β‐responsive genes using genome‐wide oligonucleotide microarrays and confirmed their dependency on Smad2, Smad3, or Smad4 by the combination of RNAi and microarray assay. The major finding from our microarray analysis was that of the 2,039 target genes seen to be regulated via TGF‐β induction, 190 were differentially transcriptionally controlled by Smad2‐Smad4 and Smad3‐Smad4 signaling and the latter control mechanism appeared to be functionally more important. We also found indirect evidence of competition between Smad2 and Smad3 for their activation when controlling the transcription of target genes. Functional analysis revealed that Smad3 and Smad4 were the predominant mediators of TGF‐β‐induced apoptosis in Hep3B cells. We provide evidence that up‐regulation of Bcl‐2‐interacting mediator of cell death (Bim), under the transcriptional control of Smad3‐Smad4 signaling, is crucial to TGF‐β‐induced apoptosis in Hep3B cells. J. Cell. Physiol. 215: 422–433, 2008. © 2007 Wiley‐Liss, Inc.
Proteomic analysis of metacyclic trypomastigotes undergoing Trypanosoma cruzi metacyclogenesis
Authors: Parodi‐Talice A. , Monteiro‐Goes V. , Arrambide N. , Avila A. R. , Duran R. , Correa A. , Dallagiovanna B. , Cayota A. , Krieger M. , Goldenberg S. , Robello C. 
Published: October 2007

AbstractTrypanosoma cruzi, the causative agent of the Chagas disease, has a complex life cycle alternating between replicative and noninfective forms with nonreplicative and infective forms of the parasite. Metacyclogenesis is a process that takes place in the invertebrate host, comprising morphogenetic transformation from a noninfective form to an infective form, such that parasites acquire the ability to invade human cells. We analyze here the metacyclogenesis process by 2D electrophoresis coupled to MALDI‐TOF MS. A large proportion of unique proteins expressed during metacyclogenesis were observed. Interestingly, 50% of the spots were found to differ between epimastigotes and trypomastigotes. We provide a 2D map of the infective metacyclic trypomastigotes. Sixty six protein spots were successfully identified corresponding to 43 different proteins. We analyzed the expression profiles for the identified proteins along metacyclogenesis and classified them into three groups according to their maximal level of expression. We detected several isoforms for a number of proteins, some displaying differential expression during metacyclogenesis. These results suggest that posttranslational modifications may be a fundamental part of the parasite's strategy for regulating gene expression during differentiation. This study contributes to the identification of relevant proteins involved in the metacyclogenesis process. The identification and molecular characterization of these proteins will render vital information about the steps of the parasite differentiation into the infective form. Copyright © 2007 John Wiley & Sons, Ltd.
Proteomic analysis reveals metabolic changes during yeast to hypha transition in Yarrowia lipolytica
Authors: Morín Matías , Monteoliva Lucía , Insenser María , Gil Concha , Domínguez Ángel 
Published: October 2007

AbstractFungal dimorphism is important for survival in different environments and has been related to virulence. The ascomycete Yarrowia lipolytica can grow as yeast, pseudomycelial or mycelial forms. We have used a Y. lipolytica parental strain and a Δhoy1 mutant, which is unable to form hypha, to set up a model for dimorphism and to characterize in more depth the yeast to hypha transition by proteomic techniques. A two‐dimensional gel electrophoresis (2‐DE) based differential expression analysis of Y. lipolytica yeast and hyphal cells was performed, and 45 differentially expressed proteins were detected; nine with decreased expression in hyphal cells were identified. They corresponded to the S. cerevisiae homologues of Imd4p, Pdx3p, Cdc19, Sse1p, Sol3p, Sod2p, Xpt1p, Mdh1p and to the unknown protein YALIOB00924g. Remarkably, most of these proteins are involved in metabolic pathways, with four showing oxidoreductase activity. Furthermore, taking into account that this is the first report of 2‐DE analysis of Y. lipolytica protein extracts, 35 more proteins from the 2D map of soluble yeast proteins, which were involved in metabolism, cell rescue, energy and protein synthesis, were identified. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of osteoporosis on bone mineral density and fracture repair in a rat femoral fracture model
Authors: McCann Roseleen M. , Colleary Gary , Geddis Carolyn , Clarke Susan A. , Jordan Grant R. , Dickson Glenn R. , Marsh David 
Published: October 2007

AbstractOsteoporosis (OP) is one of the most prevalent bone diseases worldwide with bone fracture the major clinical consequence. The effect of OP on fracture repair is disputed and although it might be expected for fracture repair to be delayed in osteoporotic individuals, a definitive answer to this question still eludes us. The aim of this study was to clarify the effect of osteoporosis in a rodent fracture model. OP was induced in 3‐month‐old rats (n = 53) by ovariectomy (OVX) followed by an externally fixated, mid‐diaphyseal femoral osteotomy at 6 months (OVX group). A further 40 animals underwent a fracture at 6 months (control group). Animals were sacrificed at 1, 2, 4, 6, and 8 weeks postfracture with outcome measures of histology, biomechanical strength testing, pQCT, relative BMD, and motion detection. OVX animals had significantly lower BMD, slower fracture repair (histologically), reduced stiffness in the fractured femora (8 weeks) and strength in the contralateral femora (6 and 8 weeks), increased body weight, and decreased motion. This study has demonstrated that OVX is associated with decrease in BMD (particularly in trabecular bone) and a reduction in the mechanical properties of intact bone and healing fractures. The histological, biomechanical, and radiological measures of union suggest that OVX delayed fracture healing. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:384–393, 2008
Matrix metalloproteinase‐2 expression and promoter/enhancer activity in skeletal muscle atrophy
Authors: Skittone Laura K. , Liu Xuhui , Tseng Alice , Kim Hubert T. 
Published: October 2007

AbstractMatrix metalloproteinase‐2 (MMP‐2) appears to be the dominant MMP activated during skeletal muscle atrophy. However, little is known about cell‐specific regulatory mechanisms of MMP‐2 transcription in vivo. In this study, we used a mouse model of muscle atrophy induced by complete Achilles tendon transection. Time‐dependent muscle weight loss, nuclei density reduction, and extracellular matrix degeneration were observed consistently after Achilles tendon transection. Increased MMP‐2 expression was confirmed at the mRNA and protein level. Experiments using transgenic mice with a MMP‐2 promoter/enhancer reporter construct demonstrated markedly increased MMP‐2 promoter/enhancer activity in atrophic skeletal muscle. Tissue‐specific upregulation of MMP‐2 promoter activity was observed not only in myocytes, but also in blood vessels, nerve, and fascia. The transcription factors c‐Jun and FosB were expressed at high levels in atrophic muscle, suggesting a role in MMP‐2 upregulation. These findings show that increased MMP‐2 activity in disused atrophic muscle and supporting tissues is regulated, at least in part, by increased MMP‐2 promoter/enhancer activity. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:357–363, 2008
Antimicrobial activity of platelet‐leukocyte gel against Staphylococcus aureus
Authors: Moojen Dirk Jan F. , Everts Peter A.M. , Schure Rose‐Minke , Overdevest Ed P. , van Zundert André , Knape Johannes T.A. , Castelein René M. , Creemers Laura B. , Dhert Wouter J.A. 
Published: October 2007

AbstractPlatelet‐leukocyte gel (PLG) contains high concentrations of platelets and leukocytes. As leukocytes play an important role in the innate host‐defense, we hypothesized that PLG might have antimicrobial properties. This study investigated the antimicrobial activity of PLG against Staphylococcus aureus and the contribution of myeloperoxidase (MPO), present in leukocytes, in this process. Platelet‐rich plasma (PRP) and platelet‐poor plasma (PPP) were obtained from whole blood of six donors. PLG was prepared by mixing PRP with autologous (PLG‐AT) or bovine thrombin (PLG‐BT). Antimicrobial activity of PLG‐AT, PLG‐BT, PRP, and PPP was determined in a bacterial kill assay. MPO release was measured by ELISA and activity was measured using a MPO activity assay. Cultures showed a rapid decrease in the number of bacteria for both PLG‐AT and PLG‐BT, which was maximal between 4 and 8 h, to approximately 1% of the bacteria in controls. The effect of PLG‐AT was largest and significantly different compared to PRP (p = 0.004) and PPP (p < 0.001), however not compared to PLG‐BT (p = 0.093). PLG‐AT, PLG‐BT, and PRP showed a comparable, gradually increasing MPO release. MPO activity was comparable for all groups and remained stable. No correlation between MPO release, activity, and bacterial kill could be found. PLG appears to have potent antimicrobial capacity, but the role of MPO in this activity is questionable. PLG might represent a useful strategy against postoperative infections. However, additional research should elucidate its exact antimicrobial activity. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:404–410, 2008
Optimization of extraction of phenolic content from hazelnut shell using response surface methodology
Authors: Stévigny Caroline , Rolle Luca , Valentini Nadia , Zeppa Giuseppe 
Published: October 2007

AbstractResponse surface methodology was applied to predict the optimum conditions for extraction of phenolic compounds in hazelnut shell. The phenolic content in the shell extract was determined spectrophotometrically according to the Folin‐Ciocalteu method and expressed as gallic acid equivalent (mg GAE g−1). Two central composite designs were used to investigate the effects of two independent variables, namely solvent composition (%) and extraction time (min), on phenolic extraction. In a first series of repeated batch extractions, the solvent consisted of different methanol percentages in distilled water at pH 4, while in a second series methanol was substituted by ethanol. The highest phenolic content (6.67 mg GAE g−1 of shell) was predicted at the extraction conditions of 55.7% ethanol and 108.7 min. These best conditions, obtained and applied to 13 different cultivars, showed values varying from 9.18 mg GAE g−1 of shell for Barcelona to 3.00 mg GAE g−1 of shell for Tonda di Giffoni. Copyright © 2007 Society of Chemical Industry