bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mitochondria‐mediated caspase‐independent apoptosis induced by cadmium in normal human lung cells
Authors: Shih Chwen‐Ming , Wu Jui‐Sheng , Ko Wun‐Chang , Wang Leng‐Fang , Wei Yau‐Huei , Liang Hsiao‐Fang , Chen Yen‐Chou , Chen Chien‐Tsu 
Published: April 2003

AbstractCadmium, a well‐known environmental hazard, has caused serious health problems in humans and animals. Accumulating evidence suggests the cadmium toxicity is mediated by oxidative stress‐induced cell death. However, the molecular signaling underlying cadmium‐induced apoptosis remains unclear. In this study, we demonstrate here that cadmium induced mixed types of cell death including primary apoptosis (early apoptosis), secondary necrosis (late apoptosis), and necrosis in normal human lung cells, MRC‐5, as revealed by chromatin condensation, phosphatidylserine (PS) externalization, and hypodiploid DNA content. The total apoptotic cells reached a plateau of around 40.0% after 24 h exposure of 100 μM cadmium. Pretreatment with Z‐Val–Ala–Asp–fluoromethylketone (Z‐VAD–fmk), a broad spectrum of caspase inhibitor, could not rescue apoptotic cells from cadmium toxicity. Coincidently, we failed to detect the activation of pro‐caspase‐3 and cleavage of PARP by immunoblot, which implies the apoptogenic activity of cadmium in MRC‐5 cells is caspase‐independent. JC‐1 staining also indicated that mitochondrial depolarization is a prelude to cadmium‐induced apoptosis, which was accompanied by a translocation of caspase‐independent pro‐apoptotic factor apoptosis‐inducing factor (AIF) into the nucleus as revealed by the immunofluorescence assay. In summary, this study demonstrated for the first time that cadmium induced a caspase‐independent apoptotic pathway through mitochondria‐mediated AIF translocation into the nucleus. J. Cell. Biochem. 89: 335–347, 2003. © 2003 Wiley‐Liss, Inc.
Leptin induces increased α2(I) collagen gene expression in cultured rat hepatic stellate cells
Authors: Saxena Neeraj K. , Saliba George , Floyd Jeffrey J. , Anania Frank A. 
Published: April 2003

AbstractLeptin is a 16‐kDa hormone with an array of biologic actions. We, and others, have demonstrated that leptin is critical to the development of liver fibrogenesis both in vitro and in the lean littermates of ob/ob mice exposed to carbon tetrachloride (CCl4). Controversy exists as to whether leptin can act as a direct cytokine in the development of increased collagen expression, and whether ob/ob mice are resistant to potential injury from CCl4. Here, we provide evidence that strongly suggests that leptin acts to increase nascent production of mRNA for the α2(I) collagen gene based upon ribonuclease protection analysis (RPA). Actinomycin D, but not cyclohexamide, or the pan‐neutralizing antibody to transforming growth factor beta one (TGFβ1), significantly diminished the effect of leptin on total α2(I) collagen mRNA levels. Further evidence that leptin acts directly on HSCs to alter gene expression in liver wounding is demonstrated by enhanced binding of phosphorylated signal transduction and activator of transcription factor 3 (pStat3) to a cis‐inducible element (SIE) oligonucleotide by electrophoretic mobility shift assay (EMSA). This consensus sequence is responsible for production of a critical collagen transcription factor, AP‐1. Finally, we have demonstrated from the ob/ob mouse model that these animals are at least as sensitive to CCl4 as their respective lean animals as assessed by serum alanine aminotransferase (ALT) measurements. Taken together, the current data provide a continued framework that leptin is a profibrogenic cytokine and plays a key role in liver fibrosis. J. Cell. Biochem. 89: 311–320, 2003. © 2003 Wiley‐Liss, Inc.
ERK, JNK, and p38 MAP kinases differentially regulate proliferation and migration of phenotypically distinct smooth muscle cell subtypes
Authors: Kavurma Mary M. , Khachigian Levon M. 
Published: April 2003

AbstractProliferation and migration of vascular smooth muscle cells (SMCs) are important processes involved in the pathogenesis of vascular disorders such as atherosclerosis and post‐angioplasty restenosis. Here we demonstrate that proliferation and migration of specific SMC subtypes is mitogen‐activated protein (MAP) kinase‐dependent. WKY12‐22 SMCs derived from the aortae of 12 day‐old pup rats proliferate and migrate faster than WKY3M‐22 SMCs derived from the aortae of adult rats. WKY12‐22 and WKY3M‐22 cells equally expressed the active forms of phospho (Thr183/Tyr185)‐c‐Jun N‐terminal kinase (JNK) and phospho (Tyr182)‐p38, whereas the activity of extracellular signal‐regulated kinase (ERK) was greater in WKY12‐22 cells compared with WKY3M‐22 cells. Proliferation of both SMC subtypes was attenuated by PD98059, SP600125 and SB202190, inhibitors of ERK, JNK, and p38, respectively. However, inhibition of PD98059 had a more profound effect on WKY12‐22 SMCs. Furthermore, migration of WKY12‐22 and WKY3M‐22 cells was inhibited by SP600125 and SB202190, however, PD98059 failed to influence migration of either SMC subtype. Hence, migration of both SMC subtypes is JNK‐ and p38‐dependent, but not ERK‐dependent. These findings demonstrate that SMC heterogeneity is mediated, at least in part, by the activity of specific MAP kinase subtypes. J. Cell. Biochem. 89: 289–300, 2003. © 2003 Wiley‐Liss, Inc.
Identification of calreticulin as a nuclear matrix protein associated with human colon cancer
Authors: Brünagel Gisela , Shah Uzma , Schoen Robert E. , Getzenberg Robert H. 
Published: April 2003

AbstractColon cancer is one of the most common malignancies among populations in the United States and Western Europe, and one of the leading causes of worldwide morbidity and mortality due to cancer. The early detection of colon cancer is central to the effective treatment of this disease and early detection markers are needed. We have demonstrated that high‐resolution two‐dimensional gel analysis of nuclear matrix proteins (NMPs) demonstrated a specific oncological fingerprint of colon cancer. Utilizing this approach, four proteins specific for colon cancer was identified. Additionally, one protein was expressed much more strongly in colon cancer compared to adjacent and normal donor tissue. The amino acid composition of this protein revealed sequence similarity with calreticulin. The multi‐functional protein, calreticulin, is normally found in the lumen of the endoplasmic reticulum although some reports have described a nuclear localization of the protein. The aim of this study was to confirm the identity of the protein as calreticulin as well as to evaluate the localization of calreticulin in the nuclear matrix of colon cancer tissue. J. Cell. Biochem. 89: 238–243, 2003. © 2003 Wiley‐Liss, Inc.
Primary cilium—is it an osteocyte's strain‐sensing flowmeter?
Authors: Whitfield James F. 
Published: April 2003

AbstractWith few exceptions, the non‐cycling cells in a vast range of animals including humans have a non‐motile primary cilium that extends from the mother centriole of the pair of centrioles in their centrosomes located between their Golgi apparatuses and nuclei. It has very recently been shown that the primary cilium of a dog or a mouse embryonic kidney cell is a fluid flowmeter studded with heterodimeric complexes of mechanoreceptors linked to Ca2+‐permeable cation channels that when the cilium is bent can send Ca2+ signals into the cell and beyond to neighboring cells through gap junctions. More than 30 years ago, osteocytes were reported also to have primary cilia, but this was promptly ignored or forgotten. Osteocytes are the bones' strain sensors, which measure skeletal activity from the effects of currents of extracellular fluid caused by their bones being bent and squeezed during various activities such as walking and running. Since bending a kidney cell's primary cilium can send a Ca2+ wave surging through itself and its neighbors, the bending of an osteocyte's primary cilium by sloshing extracellular fluid is likely to do the same thing and thus be involved in measuring and responding to bone strain. J. Cell. Biochem. 89: 233–237, 2003. © 2003 Wiley‐Liss, Inc.
Enhancement of albumin expression in bone tissues with healing rat fractures
Authors: Yamaguchi Masayoshi , Igarashi Aki , Misawa Hiroyuki , Tsurusaki Yoshinori 
Published: April 2003

AbstractThe characterization of 66 kDa protein molecule, a major protein component which is produced from femoral‐diaphyseal tissues with fracture healing (Igarashi and Yamaguchi [2002] Int. J. Mol. Med. 9:503–508), was investigated. Weaning rats were killed at 7 and 14 days after femoral fracture. When the femoral‐diaphyseal tissues with fracture healing were cultured for 48 h in a serum‐free medium, many proteins in the bone tissues were released into the medium. Analysis with sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) showed that a protein molecule of approximately 66 kDa was markedly increased in culture medium from bone tissues with fracture healing. N‐terminal sequencing of 66 kDa protein indicated that its N‐terminus was identical to that of rat albumin. Western blot analysis of medium 66 kDa protein showed expression of albumin. This expression was significantly enhanced by fracture healing. The expression of albumin was seen in the diaphyseal (cortical bone) and metaphyseal (trabecular bone) tissues of rat femur. When the femoral‐diaphyseal tissues obtained at 7 days after femoral fracture were cultured in a serum‐free medium containing either vehicle, parathyroid hormone (1–34) (10−7 M), insulin‐like growth factor‐I (10−8 M) or zinc acexamate (10−4 M), medium albumin was significantly increased in the presence of those bone‐stimulating factors. The addition of albumin (0.5 or 1.0 mg/ml of medium) caused a significant increase in calcium and deoxyribonucleic acid contents in the femoral‐diaphyseal and ‐metaphyseal tissues obtained from normal rats in vitro. The present study demonstrates that fracture healing induces a remarkable production of albumin which is a major protein component produced from femoral‐diaphyseal tissues of rats, and that albumin has an anabolic effect on bone components. J. Cell. Biochem. 89: 356–363, 2003. © 2003 Wiley‐Liss, Inc.
Transcriptional profiling of human osteoblast differentiation
Authors: Billiard J. , Moran R.A. , Whitley M.Z. , Chatterjee‐Kishore M. , Gillis K. , Brown E.L. , Komm B.S. , Bodine P.V.N. 
Published: April 2003

AbstractOsteoblast differentiation is a key aspect of bone formation and remodeling. To further our understanding of the differentiation process, we have developed a collection of conditionally immortalized adult human osteoblast cell lines representing discrete stages of differentiation. To evaluate changes in gene expression associated with differentiation, polyA(+) RNA from pre‐osteoblasts, early and late osteoblasts, and pre‐osteocytes was subjected to gene chip analysis using the Affymetrix Hu6800 chip in conjunction with an Affymetrix custom chip enriched in bone and cartilage cDNAs. Overall, the expression of 47 genes was found to change threefold or more on both chips between the pre‐osteoblastic and pre‐osteocytic stages of differentiation. Many of the observed differences, including down‐regulation of collagen type I and collagen‐processing enzymes, reflect expected patterns and support the relevance of our results. Other changes have not been reported and offer new insight into the osteoblast differentiation process. Thus, we observed regulation of factors controlling cell cycle and proliferation, reflecting decreased proliferation, and increased apoptosis in pre‐osteocytic cells. Elements maintaining the cytoskeleton, extracellular matrix, and cell–cell adhesion also changed with differentiation reflecting profound alterations in cell architecture associated with the differentiation process. We also saw dramatic down‐regulation of several components of complement and other immune response factors that may be involved in recruitment and differentiation of osteoclasts. The decrease in this group of genes may provide a mechanism for controlling bone remodeling of newly formed bone. Our screen also identified several signaling proteins that may control osteoblast differentiation. These include an orphan nuclear receptor DAX1 and a small ras‐related GTPase associated with diabetes, both of which increased with increasing differentiation, as well as a high mobility group‐box transcription factor, SOX4, that was down‐regulated during differentiation. In summary, our study provides a comprehensive transcriptional profile of human osteoblast differentiation and identifies several genes of potential importance in controlling differentiation of osteoblasts. J. Cell. Biochem. 89: 389–400, 2003. © 2003 Wiley‐Liss, Inc.
Interference of bovine herpesvirus 1 (BHV‐1) in sorbitol‐Induced apoptosis
Authors: De Martino L. , Marfé G. , Di Stefano C. , Pagnini U. , Florio S. , Crispino L. , Iovane G. , Macaluso M. , Giordano A. 
Published: April 2003

AbstractIn order to determine the ability of bovine herpesvirus type 1 (BHV‐1) to suppress apoptosis, we examined the effects of BHV‐1 infection on sorbitol‐induced apoptosis on Madin–Darby bovine kidney (MDBK) cells. BHV‐1 suppresses sorbitol‐induced apoptosis in a manner similar to that of herpes simplex virus type 1 (HSV‐1), indicating that BHV‐1 has one or more anti‐apoptotic genes. To elucidate the molecular mechanisms of apoptosis, expression of some genes encoding apoptosis‐inhibiting and ‐promoting factors were analyzed on BHV‐1 infected cells during the process of sorbitol‐induced apoptosis. Our results revealed that the expression of bcl‐2 and bcl‐xL decreased after 5 and 3 h p.i., respectively; while bax and procaspase‐3 expression increased with respect to control as a function of p.i. times and at 7 h p.i. they were not observed. We further show that the expression of p53 gene was also enhanced, suggesting that this apoptotic mechanism is p53 dependent. From these results, we propose that BHV‐1 has one or more genes encoding apoptosis‐inhibiting factors which interfere with the involvement of bcl‐2 gene family members and apoptotic pathway, depending upon caspase‐3, triggered by sorbitol. J. Cell. Biochem. 89: 373–380, 2003. © 2003 Wiley‐Liss, Inc.
Central and carboxy‐terminal regions of human p53 protein are essential for interaction and complex formation with PARP‐1
Authors: Węsierska‐Gądek Józefa , Wojciechowski Jacek , Schmid Gerald 
Published: April 2003

AbstractIt has been previously described by different groups that poly(ADP‐ribose) polymerase‐1 (PARP‐1) and the product of the tumor suppressor gene p53 form tight complexes. We investigated which domains of human PARP‐1 and of human wild‐type p53 were involved in this protein–protein interaction. We generated baculoviral constructs encoding full length protein or distinct functional domains of both proteins. Baculovirally expressed wild‐type p53 was posttranslationally modified. Full length PARP‐1 was simultaneously coexpressed in insect cells with full length wt p53 protein or its distinct truncated fragments and vice versa. Reciprocal immunoprecipitation of Sf9 cell lysates revealed that the central and carboxy‐terminal fragments of p53 were sufficient to confer binding to PARP‐1. The amino‐terminal part harboring the transactivation functional domain of p53 was dispensable. On the other hand, the amino‐terminal and central fragments of PARP‐1 were necessary for complex formation with p53 protein. Finally, we explored the functional significance of the interaction between both proteins. Inactivation of PARP‐1 resulted in the reduction of p53 steady‐state levels. Inhibition of nuclear export by leptomycin B prevented accelerated degradation of p53 in PARP‐1 KO cells and led to accumulation of p53 protein. Considering the fact that the accelerated p53 nuclear export in the absence of PARP‐1 contributes to enhanced p53 degradation, we conclude that PARP‐1 may mask the NES of p53 through complex formation with its carboxy‐terminal part, thereby preventing the export. J. Cell. Biochem. 89: 220–232, 2003. © 2003 Wiley‐Liss, Inc.
IL‐13 regulates vascular cell adhesion molecule‐1 expression in human osteoblasts
Authors: Rifas Leonard , Cheng Su‐Li 
Published: April 2003

AbstractActivated T cells (Act T) produce multiple cytokines that affect osteoblast function as well as osteoclastogenesis. One of these cytokines, IL‐13, is a multifunctional cytokine elaborated by Act T that regulates vascular cellular adhesion molecule (VCAM)‐1 expression in endothelial cells. VCAM‐1 has also been implicated in osteoclast formation by myeloma cells. We therefore studied whether IL‐13 regulates VCAM‐1 in human osteoblastic cells since these cells express RANKL, the major osteoclastogenic factor and osteoclast precursors are found adjacent to osteoblasts. Human T cells were activated in the absence or presence of Cyclosporin A (CsA), an inhibitor of the production of most activated T cell cytokines. Conditioned media were assayed for IL‐13 by ELISA. Act T produced IL‐13 and, unlike other T cell cytokines, this was elevated 3‐fold by CsA. Exposure of human osteoblasts (hOB) to doses of recombinant human IL‐13 (rhIL‐13, 0–10 ng/ml) resulted in an increase of VCAM‐1 mRNA (up to 5‐fold) within 4 h with a maximum stimulation at 1 ng/ml. CsA had no effect on basal hOB VCAM‐1 mRNA expression. Examination of VCAM‐1 on the cell surface of hOB, by immunocytochemistry, revealed increasing levels of surface expression of the protein within 16 h after stimulation with doses of rhIL‐13 (0.1–10 ng/ml) which were reflective of the mRNAs. IL‐6 production was also stimulated in a dose dependent manner with a maximum of 2.5‐fold with 1 ng/ml rhIL‐13 within 16 h. Since both VCAM‐1 and IL‐6 showed similar responses to IL‐13, IL‐6 was examined for its ability to induce VCAM‐1. Immunocytochemistry demonstrated no effect of IL‐6 on VCAM‐1 expression. These data demonstrate that during pathological processes associated with T cell activation, such as rheumatoid arthritis or possibly post‐menopausal osteoporosis, T cells may play a pivotal role in osteoclast precursor adhesion to osteoblasts as a first step prior to RANKL signaling. © 2003 Wiley‐Liss, Inc.
pp60c‐src mediates ERK activation/nuclear localization and PAI‐1 gene expression in response to cellular deformation
Authors: Samarakoon Rohan , Higgins Paul J. 
Published: April 2003

AbstractRelease of transcellular tension upon disruption of actin stress fibers with cytochalasin D (CD) and associated changes in cell morphology are reflected in the rapid transcription of “deformation‐responsive” genes. For certain genes (e.g., urokinase plasminogen activator and its type‐1 inhibitor PAI‐1), de novo mRNA synthesis appears to require cell shape‐dependent activation of the MAP kinases ERK1/2. ERK activation in response to microfilament disruption was inhibited completely by the broad‐spectrum tyrosine kinase inhibitor genistein and the relatively src‐kinase selective compound PP1. Such inhibitor sensitivity profiles suggested that src‐family members, likely pp60c‐src, were important upstream elements in deformation‐related ERK activation. pp60c‐src kinase activity was elevated fourfold within 15 min after CD addition to quiescent R22 smooth muscle cells and declined quickly thereafter. CD‐induced increases in the phosphorylation levels of both pp60c‐src and IgG heavy chain (a substrate target in the coupled immunoprecipitation/in vitro pp60c‐src kinase assay) were ablated completely by pretreatment with the src‐type kinase inhibitor PP1. Prior PP1 exposure similarly repressed CD‐stimulated PAI‐1 transcript accumulation. Consistent with the pharmacologic findings, transfection of a dominant‐negative pp60c‐src expression construct (DN‐Src) effectively suppressed (in a concentration‐dependent manner) CD‐induced PAI‐1 synthesis in R22 cells. To more specifically address the potential involvement of src kinases in CD‐initiated ERK mobilization, R22 cells were transiently co‐transfected with DN‐Src and Myc‐tagged ERK2 expression constructs, serum‐deprived then stimulated with CD. The effect of DN‐Src expression on endogenous ERK1/2 activation and nuclear translocation was assessed in separate experiments. The phosphorylation levels of both exogenous (Myc‐ERK2) and endogenous ERK1/2 targets was significantly reduced by DN‐Src; nuclear accumulation of pERK1/2 was completely inhibited. These data indicate that pp60c‐src is a critical upstream activator of the ERK cascade leading to PAI‐1 transcription in response to cellular deformation stimuli. © 2003 Wiley‐Liss, Inc.
Activation of PKC‐ε and ERK1/2 participates in shear‐induced endothelial MCP‐1 expression that is repressed by nitric oxide
Authors: Ni Chih‐Wen , Wang Danny L. , Lien Sheng‐Chieh , Cheng Jing‐Jy , Chao Yuen‐Jen , Hsieh Hsyue‐Jen 
Published: April 2003

AbstractVascular endothelial cells (ECs) continuously experience hemodynamic shear stress generated from blood flow. Previous studies have demonstrated that shear stress modulates monocyte chemotactic protein‐1 (MCP‐1) expression in ECs. This study explored the roles of protein kinase C (PKC), extracellular signal‐regulated protein kinase (ERK1/2), and nitric oxide (NO) in sheared‐induced MCP‐1 expression in ECs. The activation of PKC‐α and PKC‐ε isoforms was observed in ECs exposed to shear stress. The use of an inhibitor (calphostin C) to PKC‐α and PKC‐ε decreased ERK1/2 activation and MCP‐1 induction by shear, whereas an inhibitor (Go6976) to PKC‐α did not affect ERK1/2 activation or MCP‐1 induction. Inhibition of ERK1/2 activation by PD98059 blocked MCP‐1 induction. Transfection of ECs with an antisense to PKC‐ε abolished the shear inducibility of MCP‐1 promoter. These results demonstrate that PKC‐ε and ERK1/2 participate in shear‐induced MCP‐1 expression. We also examined the regulatory role of NO in MCP‐1 expression. An NO donor (NOC18) suppressed shear‐induced activation of PKC‐ε and ERK1/2, and also repressed MCP‐1 induction. Consistently, overexpression of endothelial nitric oxide synthase (eNOS) to enhance the endogenous generation of NO in ECs decreased the activation of PKC‐ε and ERK1/2, and also inhibited MCP‐1 expression. Taken together, these findings suggest that PKC‐ε and ERK1/2 are critical in the signaling pathway(s) leading to the MCP‐1 expression induced by shear stress. Additionally, this study indicates that NO, by repressing PKC‐ε activity and ERK pathway activation, attenuates shear‐induced MCP‐1 expression. © 2003 Wiley‐Liss, Inc.