bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in Osteoblast, Chondrocyte, and Adipocyte Lineages Mediate the Bone Anabolic Actions of PTH and Small Molecule GSK‐3 Inhibitor
Authors: Kulkarni Nalini H. , Wei Tao , Kumar Amar , Dow Ernst R. , Stewart Trent R. , Shou Jianyong , N'cho Mathias , Sterchi Diane L. , Gitter Bruce D. , Higgs Richard E. , Halladay David L. , Engler Thomas A. , Martin T. John , Bryant Henry U. , Ma Yanfei L. , Onyia Jude E. 
Published: May 2007

AbstractParathyroid hormone (PTH) and glycogen synthase kinase‐3 (GSK‐3) inhibitor 603281‐31‐8, administered once daily increased bone formation in vivo. We investigated the molecular mechanisms of the anabolic responses of PTH and 603281‐31‐8 in rat osteopenia model. Female 6‐month‐old rats were ovariectomized (Ovx) and permitted to lose bone for 1 month, followed by treatment with PTH (1–38) at 10 µg/kg/day s.c. or 603281‐31‐8 at 3 mg/kg/day p.o. for 60 days. Twenty‐four hours after the last treatment, RNA from distal femur metaphysis was subjected to gene expression analysis. Differentially expressed genes (P < 0.05) were subjected to pathway analysis to delineate relevant bio‐processes involved in skeletal biology. Genes involved in morphogenesis, cell growth/differentiation, and apoptosis were significantly altered by Ovx and the treatments. Analysis of morphogenesis genes showed an overrepresentation of genes involved in osteogenesis, chondrogenesis, and adipogenesis. A striking finding was that Ovx decreased several markers of osteogenesis/chondrogenesis and increased markers of adipogenesis/lipid metabolism. Treatment with either PTH or the GSK‐3 inhibitor reversed these effects, albeit at different levels. Histological analysis confirmed that osteopenia in Ovx animals was associated with three‐fold increase in marrow adiposity. PTH and GSK‐3 inhibitor restored bone volume, and reversed or normalized marrow adiposity. Ex vivo studies showed that PTH and GSK‐3 inhibitor increased the ratio of colony forming marrow stromal progenitors (CFU‐fs) that were alkaline phosphatase positive (putative osteoblasts). Our results suggest that the bone anabolic actions of PTH and GSK‐3 inhibitor in vivo involve concerted effects on mesenchymal lineages; osteoblasts, chondrocytes, and adipocytes. J. Cell. Biochem. 102: 1504–1518, 2007. © 2007 Wiley‐Liss, Inc.
Effect of hyperthermia and chemotherapeutic agents on TRAIL‐induced cell death in human colon cancer cells
Authors: Yoo Jinsang , Lee Yong J. 
Published: May 2007

AbstractTumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) is a promising cancer therapeutic agent because of its tumor selectivity. TRAIL is known to induce apoptosis in cancer cells but spare most normal cells. In the previous study [Yoo and Lee, 2007], we have reported that hyperthermia could enhance the cytotoxicity of TRAIL‐induced apoptosis. We observed in human colorectal cancer cell line CX‐1 that TRAIL‐induced apoptotic death and also that mild hyperthermia promoted TRAIL‐induced apoptotic death through caspase activation and cytochrome‐c release. Although its effects in vivo are not clear, hyperthermia has been used as an adjunctive therapy for cancer. Hyperthermia is often accompanied by chemotherapy to enhance its effect. In this study, CX‐1 colorectal adenocarcinoma cells were treated with TRAIL concurrently with hyperthermia and oxaliplatin or melphalan. To evaluate the cell death effects on tumor cells via hyperthermia and TRAIL and chemotherapeutic agents, FACS analysis, DNA fragmentation, and immunoblottings for PARP‐1 and several caspases and antiapoptotic proteins were performed. Activities of casapse‐8, caspase‐9, and caspase‐3 were also measured in hyperthermic condition. Interestingly, when analyzed with Western blot, we detected little change in the intracellular levels of proteins related to apoptosis. Clonogenic assay shows, however, that chemotherapeutic agents will trigger cancer cell death, either apoptotic or non‐apoptotic, more efficiently. We demonstrate here that CX‐1 cells exposed to 42°C and chemotherapeutic agents were sensitized and died by apoptotic and non‐apoptotic cell death even in low concentration (10 ng/ml) of TRAIL. J. Cell. Biochem. 103: 98–109, 2008. © 2007 Wiley‐Liss, Inc.
Characterization of voltage‐and Ca2+‐activated K+ channels in rat dorsal root ganglion neurons
Authors: Li Wei , Gao Shang‐Bang , Lv Cai‐Xia , Wu Ying , Guo Zhao‐Hua , Ding Jiu‐Ping , Xu Tao 
Published: May 2007

AbstractAuxiliary β‐subunits associated with pore‐forming Slo1 α‐subunits play an essential role in regulating functional properties of large‐conductance, voltage‐ and Ca2+‐activated K+ channels commonly termed BK channels. Even though both noninactivating and inactivating BK channels are thought to be regulated by β‐subunits (β1, β2, β3, or β4), the molecular determinants underlying inactivating BK channels in native cells have not been extensively demonstrated. In this study, rβ2 (but not rβ3‐subunit) was identified as a molecular component in rat lumbar L4‐6 dorsal root ganglia (DRG) by RT‐PCR responsible for inactivating large‐conductance Ca2+‐dependent K+ currents (BKi currents) in small sensory neurons. The properties of native BKi currents obtained from both whole‐cell and inside‐out patches are very similar to inactivating BK channels produced by co‐expressing mSlo1 α‐ and hβ2‐subunits in Xenopus oocytes. Intracellular application of 0.5 mg/ml trypsin removes inactivation of BKi channels, and the specific blockers of BK channels, charybdotoxin (ChTX) and iberiotoxin (IbTX), inhibit these BKi currents. Single BKi channel currents derived from inside‐out patches revealed that one BKi channel contained three rβ2‐subunits (on average), with a single‐channel conductance about 217 pS under 160 K+ symmetrical recording conditions. Blockade of BKi channels by 100 nM IbTX augmented firing frequency, broadened action potential waveform and reduced after‐hyperpolarization. We propose that the BKi channels in small diameter DRG sensory neurons might play an important role in regulating nociceptive input to the central nervous system (CNS). J. Cell. Physiol. 212: 348–357, 2007. © 2007 Wiley‐Liss, Inc.
Morphogenetic signals from chondrocytes promote chondrogenic and osteogenic differentiation of mesenchymal stem cells
Authors: Hwang Nathaniel S. , Varghese Shyni , Puleo Christopher , Zhang Zijun , Elisseeff Jennifer 
Published: May 2007

AbstractMesenchymal stem cells (MSCs) are potentially useful cells for musculoskeletal tissue engineering. However, controlling MSC differentiation and tissue formation in vivo remains a challenge. There is a significant need for well‐defined and efficient protocols for directing MSC behaviors in vivo. We hypothesize that morphogenetic signals from chondrocytes may regulate MSC differentiation. In micromass culture of MSCs, incubation with chondrocyte‐conditioned medium (CCM) significantly enhanced the production of cartilage specific matrix including type II collagen. In addition, incubation of MSCs with conditioned medium supplemented with osteogenic factors induced more osteogenesis and accumulation of calcium and increased ALP activity. These findings reveal that chondrocyte‐secreted factors promote chondrogenesis as well as osteogenesis of MSCs during in vitro micromass culture. Moreover, when MSCs expanded with chondrocyte‐conditioned medium were encapsulated in hydrogels and subsequently implanted into athymic mice, basophilic extracellular matrix deposition characteristic of neocartilage was evident. These results indicate that articular chondrocytes produce suitable morphogenetic factors that induce the differentiation program of MSCs in vitro and in vivo. J. Cell. Physiol. 212: 281–284, 2007. © 2007 Wiley‐Liss, Inc.
IGF‐1 activates hEAG K+ channels through an Akt‐dependent signaling pathway in breast cancer cells: Role in cell proliferation
Authors: Borowiec Anne‐Sophie , Hague Frédéric , Harir Noria , Guénin Stéphanie , Guerineau François , Gouilleux Fabrice , Roudbaraki Morad , Lassoued Kaiss , Ouadid‐Ahidouch Halima 
Published: May 2007

AbstractPrevious work from our laboratory has shown that human ether à go‐go (hEAG) K+ channels are crucial for breast cancer cell proliferation and cell cycle progression. In this study, we investigated the regulation of hEAG channels by an insulin‐like growth factor‐1 (IGF‐1), which is known to stimulate cell proliferation. Acute applications of IGF‐1 increased K+ current‐density and hyperpolarized MCF‐7 cells. The effects of IGF‐1 were inhibited by hEAG inhibitors. Moreover, IGF‐1 increased mRNA expression of hEAG in a time‐dependent manner in parallel with an enhancement of cell proliferation. The MCF‐7 cell proliferation induced by IGF‐1 is inhibited pharmacologically by Astemizole or Quinidine or more specifically using siRNA against hEAG channel. Either mitogen‐activated protein kinase (MAPK) or phosphatidylinositol 3‐kinase (PI3K) are known to mediate IGF‐1 cell proliferative signals through the activation of extracellular signal‐regulated kinase 1/2 (Erk 1/2) and Akt, respectively. In MCF‐7 cells, IGF‐1 rapidly stimulated Akt phosphorylation, whereas IGF‐1 had little stimulating effect on Erk 1/2 which seems to be constitutively activated. The application of wortmannin was found to block the effects of IGF‐1 on K+ current. Moreover, the inhibition of Akt phosphorylation by the application of wortmannin or by a specific reduction of Akt kinase activity reduced the hEAG mRNA levels. Taken together, our results show, for the first time, that IGF‐1 increases both the activity and the expression of hEAG channels through an Akt‐dependent pathway. Since a hEAG channel is necessary for cell proliferation, its regulation by IGF‐1 may thus play an important role in IGF‐1 signaling to promote a mitogenic effect in breast cancer cells. J. Cell. Physiol. 212:690–701, 2007. © 2007 Wiley‐Liss, Inc.
Increased Smad1 expression and transcriptional activity enhances trans‐differentiation of hepatic stellate cells
Authors: Shen Hong , Fan Jianghong , Burczynski Frank , Minuk Gerald Y. , Cattini Peter , Gong Yuewen 
Published: May 2007

AbstractSmad1 is a receptor‐activated intracellular signaling protein, which mediates signal transduction of bone morphogenetic proteins. Current study investigated the expression and transcriptional activity of Smad1 during hepatic stellate cell (HSC) activation. Rat HSCs were isolated from rats at 1, 2, 3 and 4 days after gavaged with carbon tetrachloride (CCl4) or corn oil. RT‐PCR, Western blot, gel‐shift assay and luciferase assay were employed to examine Smad1 expression and transcriptional activity, respectively. CCl4‐cirrhotic liver fat‐storing cells‐8B (CFSC‐8B) cells were infected with recombinant adenoviruses of Smad1 and/or Smad1 shRNA. Both mRNA and protein levels of Smad1 were significantly increased at 48 h after gavage of CCl4. Gel shift assays demonstrated a significant increase in nuclear Smad1 in day 9 HSCs. Transfection of HSCs with Smad1 responsible luciferase indicated an increase in Smad1 transcriptional activity in day 6 HSCs (1.563 ± 0.229 in day 6 versus 0.785 ± 0.192 in day 3). When CFSC‐8B cells were infected with adenoviruses with Smad1 or Smad1 short hairpin RNA (shRNA), there was an increase or decrease in Smad1 mRNA and protein, respectively. Smooth muscle α‐actin expression was increased or decreased according to induction or reduction of Smad1. In conclusion, there were significantly increases in Smad1 expression and transcriptional activity during in vivo activation of hepatic stellate cells. J. Cell. Physiol. 212:764–770, 2007. © 2007 Wiley‐Liss, Inc.
Importance of several cysteine residues for the chloride conductance of trout anion exchanger 1 (tAE1)
Authors: Martial Sonia , Guizouarn Hélène , Gabillat Nicole , Pellissier Bernard , Borgese Franck 
Published: May 2007

AbstractIn this study, we devised a cysteine‐focused point mutation analysis of the chloride channel function of trout anion exchanger 1 (tAE1) expressed in X. lævis oocytes. Seven cysteines, belonging to the transmembrane domain of tAE1, were mutated into serines (either individually or in groups) and the effects of these mutations on the chloride conductance of injected oocytes were measured. We showed that three cysteines were essential for the functional expression of tAE1. Namely, mutations C462S, C583S and C588S reduced Cl− conductance by 68%, 52% and 83%, respectively, when compared to wild type tAE1. These residual conductances were still inhibited by 0.5 mM niflumic acid. Western blot experiments demonstrated that C462 was involved in protein expression onto the plasma membrane. A mutant devoid of this residue was unable to express onto the plasma membrane, especially if several other cysteines were missing: consequently, the cysteine‐less mutant of tAE1 was not functional. C583 and C588 were involved in the channel function of tAE1 as shown by anion substitution experiments proving that selectivity of the mutated pore differs from the wild type one. On the contrary, they were not involved in the Cl−/HCO exchange function of tAE1, as demonstrated by intracellular pH measurements. These and several complementary mutations allow us to conclude that a mutant of tAE1 containing the sole C462 can drive a marginal Cl− current; however, the minimal configuration necessary to get optimal functional expression of the tAE1 chloride channel is that of a mutant containing unaffected residues C462, C583 and C588. J. Cell. Physiol. 213: 70–78, 2007. © 2007 Wiley‐Liss, Inc.
Stimulation by ghrelin of p42/p44 mitogen‐activated protein kinase through the GHS‐R1a receptor: Role of G‐proteins and β‐arrestins
Authors: Camiña Jesus P. , Lodeiro Maria , Ischenko Olga , Martini Ana C. , Casanueva Felipe F. 
Published: May 2007

AbstractResults presented in this study indicate that in human embryonic kidney 293 cells (HEK 293), the ghrelin receptor growth hormone secretagogue receptor type 1a (GHS‐R1a) activates the extracellular signal‐related kinases 1 and 2 (ERK 1/2) via three pathways. One pathway is mediated by the β‐arrestins 1 and 2, and requires entry of the receptor into a multiprotein complex with the β‐arrestins, Src, Raf‐1, and ERK 1/2. A second pathway is Gq/11‐dependent and involves a Ca2+‐dependent PKC (PKCα/β) and Src. A third pathway is Gi‐dependent and involves phosphoinositide 3‐kinase (PI3K), PKCε, and Src. Our current study reveals that Gi/o‐ and Gq/11‐proteins are crucially involved in the β‐arrestin‐mediated ERK 1/2 activation. These results thus support the view that the β‐arrestins act as both scaffolding proteins and signal transducers in ERK 1/2 activation, as reported for other receptors. The different pathways of ERK 1/2 activation suggest that binding to GHS‐R1a activates ERK 1/2 pools at different locations within the cell, and thus probably with different physiological consequences. J. Cell. Physiol. 213: 187–200, 2007. © 2007 Wiley‐Liss, Inc.
Cell cycle dependent phosphorylation and subnuclear organization of the histone gene regulator p220NPAT in human embryonic stem cells
Authors: Ghule Prachi N. , Becker Klaus A. , Harper J. Wade , Lian Jane B. , Stein Janet L. , van Wijnen Andre J. , Stein Gary S. 
Published: May 2007

AbstractHuman embryonic stem (ES) cells have an expedited cell cycle (∼15 h) due to an abbreviated G1 phase (∼2.5 h) relative to somatic cells. One principal regulatory event during cell cycle progression is the G1/S phase induction of histone biosynthesis to package newly replicated DNA. In somatic cells, histone H4 gene expression is controlled by CDK2 phosphorylation of p220NPAT and localization of HiNF‐P/p220NPAT complexes with histone genes at Cajal body related subnuclear foci. Here we show that this ‘S point’ pathway is operative in situ in human ES cells (H9 cells; NIH‐designated WA09). Immunofluorescence microscopy shows an increase in p220NPAT foci in G1 reflecting the assembly of histone gene regulatory complexes in situ. In contrast to somatic cells where duplication of p220NPAT foci is evident in S phase, the increase in the number of p220NPAT foci in ES cells appears to precede the onset of DNA synthesis as measured by BrdU incorporation. Phosphorylation of p220NPAT at CDK dependent epitopes is most pronounced in S phase when cells exhibit elevated levels of cyclins E and A. Our data indicate that subnuclear organization of the HiNF‐P/p220NPAT pathway is rapidly established as ES cells emerge from mitosis and that p220NPAT is subsequently phosphorylated in situ. Our findings establish that the HiNF‐P/p220NPAT gene regulatory pathway operates in a cell cycle dependent microenvironment that supports expression of DNA replication‐linked histone genes and chromatin assembly to accommodate human stem cell self‐renewal. J. Cell. Physiol. 213: 9–17, 2007. © 2007 Wiley‐Liss, Inc.
Complement 3 is involved in changing the phenotype of human glomerular mesangial cells
Authors: Wan Jian‐Xin , Fukuda Noboru , Endo Morito , Tahira Yoshiko , Yao En‐Hui , Matsuda Hiroyuki , Ueno Takahiro , Matsumoto Koichi 
Published: May 2007

AbstractComplement activation contributes to tissue injury in various forms of glomerulopathy and is characterized by deposition of complement components, which accelerates the progression of chronic renal damage. We recently reported that complement 3 (C3), a critical component of the complement system, is associated with the synthetic phenotype of vascular smooth muscle cells. It is possible that C3 stimulates mesangial cells to assume the synthetic phenotype to, in turn, induce glomerular injury and sclerosis. We investigated the role of C3 in the growth and phenotype of mesangial cells. Cultured human mesangial cells (HMCs) expressed C3 mRNA and protein, and levels were increased in response to IFN‐γ and TNF‐α. HMCs also expressed C3a receptor mRNA and protein. Exogenous C3a stimulated DNA synthesis in HMCs in a dose‐dependent manner. C3a decreased expression h‐caldesmon mRNA, a marker of the contractile phenotype, and increased the expression of osteopontin, matrix Gla, and collagen type1 α1 (collagen IV) mRNAs, which are markers of the synthetic phenotype. C3a decreased expression of α‐smooth muscle actin in HMCs. Small interfering RNA (siRNA) targeting C3 reduced the DNA synthesis and proliferation of HMCs, increased expression of h‐caldesmon mRNA, and decreased expression of osteopontin, matrix Gla, and collagen IV mRNAs in HMCs. These results indicate that C3 causes HMCs to convert to the synthetic phenotype and stimulates growth of mesangial cells, suggesting that C3 may play an important role in phenotypic regulation of mesangial cells in renal diseases. J. Cell. Physiol. 213: 495–501, 2007. © 2007 Wiley‐Liss, Inc.
AFAP‐110 is required for actin stress fiber formation and cell adhesion in MDA‐MB‐231 breast cancer cells
Authors: Dorfleutner Andrea , Stehlik Christian , Zhang Jing , Gallick Gary E. , Flynn Daniel C. 
Published: May 2007

AbstractRegulation of actin organization and dynamics is a highly complex process that involves a number of actin‐binding proteins, including capping, branching, severing, sequestering, and cross‐linking proteins. The actin‐binding and cross‐linking protein AFAP‐110 is expressed in normal myoepithelial cells. Screening of different breast epithelial cell lines revealed high expression levels of AFAP‐110 in the human breast cancer cell lines MDA‐MB‐231 and MDA‐MB‐435. Knockdown of AFAP‐110 expression in MDA‐MB‐231 cells does not result in any changes in cell proliferation but did result in a loss of actin stress fiber cross‐linking and decreased adhesion to fibronectin. An inducible knockdown approach confirms that MDA‐MB‐231 breast cancer cells require AFAP‐110 expression for stress fiber formation and adhesion. Thus, AFAP‐110 may provide cytoskeletal tension through stress fiber formation, which is required for focal adhesion formation. Indeed, we could not detect any focal contacts or focal adhesions in AFAP‐110 knockdown cells after adhesion to fibronectin. Although expression levels of crucial focal adhesion components were not influenced by AFAP‐110 expression levels, treatment of AFAP‐110 knockdown cells with LPA did not result in induction of actin stress fibers and focal adhesions. In summary, AFAP‐110 plays an important role in MDA‐MB‐231 breast cancer cell adhesion possibly by regulating stress filament cross‐linking which would promote focal adhesion formation. J. Cell. Physiol. 213:740–749. © 2007 Wiley‐Liss, Inc.
Suppression by glutamate of proliferative activity through glutathione depletion mediated by the cystine/glutamate antiporter in mesenchymal C3H10T1/2 stem cells
Authors: Iemata Mika , Takarada Takeshi , Hinoi Eiichi , Taniura Hideo , Yoneda Yukio 
Published: May 2007

AbstractAlthough previous studies including ours have demonstrated the functional expression of different glutamate (Glu) signaling machineries such as Glu receptors (GluRs) and transporters in osteoblasts and chondrocytes, little attention has been paid to the role of Glu in their ancestral mesenchymal stem cells to date. In the present study, we have evaluated the possible functionality of Glu in cultured mouse mesenchymal stem cell line C3H10T1/2 cells endowed to proliferate for the self‐renewal and to differentiate toward osteoblast, chondrocyte, adipocyte, and myocyte lineages. Expression of mRNA was for the first time shown with the cystine/Glu antiporter composed of xCT and 4F2hc subunits, in addition to particular excitatory amino acid transporter (EAAT) isoforms and ionotropic GluRs, in undifferentiated C3H10T1/2 cells. Glu significantly suppressed the proliferation activity at a concentration over 500 µM without inducing cell death or differentiation, while the suppression occurred in a manner sensitive to the prevention by cystine and reduced glutathione (GSH), but not by EAAT inhibitors. A significant decrease was seen in intracellular GSH levels in C3H10T1/2 cells cultured with Glu, whereas the cellular proliferation activity was drastically decreased by the addition of the GSH depleter cyclohexene‐1‐one and the GSH biosynthesis inhibitor L‐buthionine‐[S,R]‐sulfoximine, respectively. Transient overexpression of both xCT and 4F2hc subunits led to an increased basal proliferative activity in C3H10T1/2 cells. These results suggest that Glu could suppress the cellular proliferation toward self‐renewal through a mechanism associated with the depletion of intracellular GSH after promoting the retrograde operation of the cystine/Glu antiporter in C3H10T1/2 cells. J. Cell. Physiol. 213:721–729. © 2007 Wiley‐Liss, Inc.