Role of F-actin organization in p38 MAP kinase-mediated apoptosis and necrosis in neonatal rat cardiomyocytes subjected to simulated ischemia and reoxygenation

Okada, Takayuki; Otani, Hajime; Wu, Yue; Kyoi, Shiori; Enoki, Chiharu; Fujiwara, Hiroyoshi; Sumida, Tomohiko; Hattori, Reiji; Imamura, Hiroji

doi:10.1152/ajpheart.00462.2005

Cited by 49 publications

(45 citation statements)

References 55 publications

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“…Cytochalasin D is a fungal alkaloid that depolymerizes actin filaments by binding to the + end of F-actin thus blocking the addition of more units. It was used previously in the range of 1-40μM [45] to disrupt actin cytoskeleton in cardiomyocytes [46,47]. Our use of 2μM is consistent with those studies.…”

Section: Selection Of Topographical Cues Electrical Field Stimulatiosupporting

confidence: 88%

Interactive effects of surface topography and pulsatile electrical field stimulation on orientation and elongation of fibroblasts and cardiomyocytes

Au¹,

Cheng²,

Chowdhury³

et al. 2007

Biomaterials

177

166

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In contractile tissues such as myocardium, functional properties are directly related to the cellular orientation and elongation. Thus, tissue engineering of functional cardiac patches critically depends on our understanding of the interaction between multiple guidance cues such as topographical, adhesive or electrical. The main objective of this study was to determine the interactive effects of contact guidance and electrical field stimulation on elongation and orientation of fibroblasts and cardiomyocytes, major cell populations of the myocardium. Polyvinyl surfaces were abraded using lapping paper with grain size 1 to 80μm, resulting in V-shaped abrasions with the average abrasion peak-to-peak width in the range from 3 to 13μm, and the average depth in the range from 140nm to 700nm (AFM). The surfaces with abrasions 13μm wide and 700nm deep, exhibited the strongest effect on neonatal rat cardiomyocyte elongation and orientation as well as statistically significant effect on orientation of fibroblasts, thus they were utilized for electrical field stimulation. Electrical field stimulation was performed using a regime of relevance for heart tissue in vivo as well as for cardiac tissue engineering. Stimulation (square pulses, 1ms duration, 1Hz, 2.3V/cm or 4.6V/cm) was initiated 24hr after cell seeding and maintained for additional 72hr. The cover slips were positioned between the carbon rod electrodes so that the abrasions were either parallel or perpendicular to the field lines. Non-abraded surfaces were utilized as controls. Field stimulation did not affect cell viability (live/dead staining). The presence of a well developed contractile apparatus in neonatal rat cardiomyocytes (staining for cardiac Troponin I and actin filaments) was identified in the groups cultivated on abraded surfaces in the presence of field stimulation. Overall we observed that i) fibroblast and cardiomyocyte elongation on non-abraded surfaces was significantly enhanced by electrical field stimulation ii) electrical field stimulation promoted orientation of fibroblasts in the direction perpendicular to the field lines when the abrasions were also placed perpendicular to the field lines and iii) topographical cues were a significantly stronger determinant of cardiomyocyte orientation than the electrical field stimulation. The orientation and elongation response of cardiomyocytes was completely abolished by inhibition of actin polymerization (Cytochalasin D) and only partially by inhibition of phosphatidyl-inositol 3 kinase (PI3K) pathway (LY294002).

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Section: Selection Of Topographical Cues Electrical Field Stimulatiosupporting

confidence: 88%

Interactive effects of surface topography and pulsatile electrical field stimulation on orientation and elongation of fibroblasts and cardiomyocytes

Au¹,

Cheng²,

Chowdhury³

et al. 2007

Biomaterials

177

166

View full text Add to dashboard Cite

show abstract

“…Despite the increased p38 MAPK activity, cell viability was higher than control, suggesting that p38 MAPK activity is not completely related to transcription of apoptotic cell signaling. Recently, Okada et al (38) reported that p38 MAPK plays a differential role in cardiomyocytes, protecting or killing, depending on its role in signal transduction (38). A recent report (33) suggests that the p38 MAPK ␤-isoform is prosurvival.…”

Section: Discussionmentioning

confidence: 99%

Heat shock protects cardiac cells from doxorubicin-induced toxicity by activating p38 MAPK and phosphorylation of small heat shock protein 27

Venkatakrishnan¹,

Tewari²,

Moldovan³

et al. 2006

American Journal of Physiology-Heart and Circulatory Physiology

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. Heat shock protects cardiac cells from doxorubicin-induced toxicity by activating p38 MAPK and phosphorylation of small heat shock protein 27. Am J Physiol Heart Circ Physiol 291: H2680 -H2691, 2006. First published June 16, 2006 doi:10.1152/ajpheart.00395.2006 and its derivatives are used as chemotherapeutic drugs to treat cancer patients. However, production of DOX-mediated reactive oxygen species (ROS) by prolonged use of these drugs has been found to cause dilative cardiomyopathy and congestive heart failure. Thus various preventive modalities have been developed to avoid this side effect. We have found that the DOX-mediated oxidant-induced toxicity in cardiac cells could be minimized by hyperthermia-induced small heat shock protein 27 (HSP27); that is, this protein acts as an endogenous antioxidant against DOX-derived oxidants such as H 2O2. Heat shockinduced HSP27 was found to act as an antiapoptotic protein (reducing ROS and Bax-to-Bcl2 ratio) against DOX, and its phosphorylated isoforms stabilized F-actin remodeling in DOX-treated cardiac cells and, hence, attenuated the toxicity. Protein kinase assays and proteomic analyses suggested that higher expression of HSP27 and its phosphorylation are responsible for the protection in heat-shocked cells. Two-dimensional gel electrophoresis showed six isoforms (nonphosphorylated and phosphorylated) of HSP27. Matrix-assisted laser desorption/ionization time of flight analyses showed ␣-and ␤-isoforms of HSP27, which are phosphorylated by various protein kinases. Ser 15 and Ser 85 phosphorylation of HSP27 by MAPK-assisted protein kinase 2 was found to be the key mechanism in reduction of apoptosis and facilitation of F-actin remodeling. The present study illustrates that hyperthermia protects cells from DOX-induced death through induction and phosphorylation of HSP27 and its antiapoptotic and actin-remodeling activities. apoptosis; cardiomyopathy; hyperthermia ADRIAMYCIN DERIVATIVES, such as doxorubicin (DOX), are widely used as anticancer drugs. Unfortunately, prolonged use of these drugs to treat cancer patients has resulted in the development of dilative cardiomyopathy (DCM) and congestive heart failure (CHF) within a few years after cessation of treatment, irrespective of age and race (36). To avoid this side effect, new anthracyclin derivatives with less toxicity to the heart, new formulations in the form of encapsulation into delivery vehicles such as microemulsions, and new targeted delivery modalities to selectively deliver the drug to the desired site (preventing accumulation in the heart) have emerged (39).However, there has been no significant improvement in our ability to avoid this problem, and this effect has not been completely eliminated. At the same time, attempts to understand the actual mechanism of DOX-induced DCM and CHF have been appearing with increasing frequency in recent literature. Fortunately, the mechanisms whereby DOX and its analogs kill tumor cells (intended effect) and cause DCM and CHF (unwanted effects) are different, indicating...

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“…We assessed the effects of inhibiting PVT1 expression on programmed cell death in cells with and without PVT1 amplification/overexpression by measuring membrane permeability (22), cell morphology, and F-actin reorganization (23, 24) using high-content image analyses. YO-PRO-1 dye uptake increases when cells lose membrane integrity during cell death, whereas F-actin reorganization results in increased Alexa Fluor 488-phalloidin binding that has been associated with earlier stages of apoptosis (24). Beginning at 8 h after transfection, siPVT1a significantly increased YO-PRO-1 dye uptake and F-actin staining relative to LipofectAMINE controls in HEY and CAOV4 cell lines in which PVT1 is amplified and overexpressed ( Fig.…”

Section: Resultsmentioning

confidence: 90%

Amplification of PVT1 Contributes to the Pathophysiology of Ovarian and Breast Cancer

Guan

Kuo

Stilwell

et al. 2007

Clinical Cancer Research

325

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Purpose: This study was designed to elucidate the role of amplification at 8q24 in the pathophysiology of ovarian and breast cancer because increased copy number at this locus is one of the most frequent genomic abnormalities in these cancers. Experimental Design:To accomplish this, we assessed the association of amplification at 8q24 with outcome in ovarian cancers using fluorescence in situ hybridization to tissue microarrays and measured responses of ovarian and breast cancer cell lines to specific small interfering RNAs against the oncogene MYC and a putative noncoding RNA, PVT1, both of which map to 8q24. Results: Amplification of 8q24 was associated with significantly reduced survival duration. In addition, small interfering RNA^mediated reduction in either PVT1 or MYC expression inhibited proliferation in breast and ovarian cancer cell lines in which they were both amplified and overexpressed but not in lines in which they were not amplified/overexpressed. Inhibition of PVT1 expression also induced a strong apoptotic response in cell lines in which it was overexpressed but not in lines in which it was not amplified/overexpressed. Inhibition of MYC, on the other hand, did not induce an apoptotic response in cell lines in which MYC was amplified and overexpressed. Conclusions: These results suggest that MYC and PVT1 contribute independently to ovarian and breast pathogenesis when overexpressed because of genomic abnormalities. They also suggest that PVT1-mediated inhibition of apoptosis may explain why amplification of 8q24 is associated with reduced survival duration in patients treated with agents that act through apoptotic mechanisms.Amplification of a region on chromosome 8q24 is one of the most frequent events in carcinomas, including serous ovarian and breast cancers, and has been associated with reduced survival duration in some studies (1, 2). The well-established oncogene MYC maps to this locus and likely contributes to the pathophysiology of cancers in which it is amplified. However, the PVT1 transcript also maps to this region and has been implicated in cancer pathophysiology as well (3). In mouse, for example, the pvt-1 locus is a site of recurrent translocation in plasmacytomas (4, 5) and is a common site of tumorigenic retroviral insertion in lymphomas (6). In humans, the region homologous to pvt-1 is a site of recurrent translocation between chromosomes 2 and 8 (7, 8) and its first exon is coamplified with MYC in colon carcinoma cell lines (9). PVT1 has been suggested as a MYC activator (10); however, little evidence exists to support that role. Moreover, evidence is now emerging that PVT1 may act as a noncoding RNA 12 that is strongly conserved between mouse and human.We now present evidence that both PVT1 and MYC contribute to ovarian and breast cancer pathophysiology when 12 Huppi et al., personal communication.

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Role of F-actin organization in p38 MAP kinase-mediated apoptosis and necrosis in neonatal rat cardiomyocytes subjected to simulated ischemia and reoxygenation

Cited by 49 publications

References 55 publications

Interactive effects of surface topography and pulsatile electrical field stimulation on orientation and elongation of fibroblasts and cardiomyocytes

Interactive effects of surface topography and pulsatile electrical field stimulation on orientation and elongation of fibroblasts and cardiomyocytes

Heat shock protects cardiac cells from doxorubicin-induced toxicity by activating p38 MAPK and phosphorylation of small heat shock protein 27

Amplification of PVT1 Contributes to the Pathophysiology of Ovarian and Breast Cancer

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