scholarly journals Renal Mesangial Cells Isolated from Sphingosine Kinase 2 Transgenic Mice Show Reduced Proliferation and are More Sensitive to Stress-Induced Apoptosis

2018 ◽  
Vol 47 (6) ◽  
pp. 2522-2533
Author(s):  
Sandra Beyer ◽  
Stephanie Schwalm ◽  
Josef Pfeilschifter ◽  
Andrea Huwiler
Keyword(s):  
Cell Growth ◽  
Transgenic Mice ◽  
Mesangial Cells ◽  
Normal Growth ◽  
Growth Conditions ◽  
Mitochondrial Pathway ◽  
Cell Functions ◽  
Transgenic Cells ◽  
Induced Apoptosis

Background/Aims: Sphingosine 1-phosphate (S1P) is considered as a key molecule regulating various cell functions including cell growth and death. It is produced by two sphingosine kinases (SK) denoted as SK-1 and SK-2. Whereas SK-1 has been extensively studied and has been appointed a role in promoting cell growth, the function of SK-2 is controversial, and both pro-proliferative and pro-apoptotic functions have been suggested. In this study we investigated whether renal mesangial cells isolated from transgenic mice overexpressing the human Sphk2 gene (hSK2-tg) showed an altered cell response towards growth-inducing and apoptotic stimuli. Methods: hSK2-tg mice were generated by using a Quick KnockinR strategy. Renal mesangial cells were isolated by a differential sieving method and further cultivated in vitro. Lipids were quantified by mass spectrometry. Protein expression was determined by Western blot analysis, cell proliferation was determined by 3H-thymidine incorporation, and apoptosis was determined by a DNA fragmentation ELISA. Results: We show here that kidneys and mesangial cells from hSK2-tg mice express the hSK2 as well as the endogenous mouse mSK2. hSK2 and mSK2 predominantly resided in the cytosol of quiescent transgenic cells. However, S1P accumulated strongly in the nucleus and only minimally in the cytosol of transgenic cells. Functionally, hSK2-tg cells proliferated less than control cells under normal growth conditions and were also more sensitive towards stress-induced apoptosis. On the molecular level, this was reflected by reduced ERK and Akt/PKB activation, and upon staurosporine treatment, by a sensitized mitochondrial pathway as manifested by reduced anti-apoptotic Bcl-XL expression and increased cleavage of caspase-9, downstream caspase-3 and PARP-1. Conclusion: Altogether, these data demonstrate that SK-2 exerts an antiproliferative and apoptosis-sensitizing effect in renal mesangial cells which suggests that selective inhibitors of SK-2 may promote proliferation and reduce apoptosis and this may have impact on the outcome of proliferation-associated diseases such as mesangioproliferative glomerulonephritis.

Prevention of cytokine withdrawal-induced apoptosis by Mcl-1 requires interaction between Mcl-1 and Bim

2010 ◽  
Vol 88 (5) ◽  
pp. 809-818 ◽  
Author(s):  
Sarwat Jamil ◽  
Shih Wei Wang ◽  
Lise Bondy ◽  
Shadi Mojtabavi ◽  
Vincent Duronio
Keyword(s):  
Normal Growth ◽  
Growth Conditions ◽  
Mitochondrial Pathway ◽  
Hemopoietic Cells ◽  
Primary Bone ◽  
Induced Apoptosis ◽  
Apoptotic Effects ◽  
Mutant Forms ◽  
Pest Region ◽  
Primary Bone Marrow

Growth factor withdrawal from hemopoietic cells results in activation of the mitochondrial pathway of apoptosis. Members of the Bcl-2 family regulate this pathway, with anti-apoptotic members counteracting the effects of pro-apoptotic members. We investigated the effect on Mcl-1 function of mutation at a conserved threonine 163 residue (T163) in its proline, glutamate, serine, and threonine rich (PEST) region. Under normal growth conditions, Mcl-1 half-life increased with alteration of T163 to glutamic acid, but decreased with mutation to alanine. However, both T163 mutants exhibited greater pro-survival effects compared with the wild type, which can be explained by an increased stability of the T163A mutant in cytokine-starved conditions. Both the mutant forms exhibited prolonged binding to pro-apoptotic Bim in cytokine-deprived cells. The extent to which Mcl-1 mutants were able to exert their anti-apoptotic effects correlated with their ability to associate with Bim. We further observed that primary bone marrow derived macrophages survived following cytokine withdrawal as long as Bim and Mcl-1 remained associated. In our study, we were unable to detect a role for GSK-3-mediated regulation of Mcl-1 expression. Based on these results we propose that upon cytokine withdrawal, survival of hemopoietic cells depends on association between Mcl-1 and Bim. Furthermore, alteration of T163 of Mcl-1 may change the protein such that its association with Bim is affected, resulting in prolonged association and increased survival.

Modulation of T-Cell Functions in KIR2DL3 (CD158b) Transgenic Mice

Blood ◽  
1999 ◽  
Vol 94 (7) ◽  
pp. 2396-2402 ◽  
Author(s):  
Anna Cambiaggi ◽  
Sylvie Darche ◽  
Sophie Guia ◽  
Philippe Kourilsky ◽  
Jean-Pierre Abastado ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Transgenic Mice ◽  
T Cell Activation ◽  
Cell Activation ◽  
Killer Cell ◽  
In Vitro Proliferation ◽  
Cell Functions ◽  
Double Transgenic Mice

In humans, a minor subset of T cells express killer cell Ig-like receptors (KIRs) at their surface. In vitro data obtained with KIR+ β and γδ T-cell clones showed that engagement of KIR molecules can extinguish T-cell activation signals induced via the CD3/T-cell receptor (TCR) complex. We analyzed the T-cell compartment in mice transgenic for KIR2DL3 (Tg-KIR2DL3), an inhibitory receptor for HLA-Cw3. As expected, mixed lymphocyte reaction and anti-CD3 monoclonal antibody (MoAb)-redirected cytotoxicity exerted by freshly isolated splenocytes can be inhibited by engagement of transgenic KIR2DL3 molecules. In contrast, antigen and anti-CD3 MoAb-induced cytotoxicity exerted by alloreactive cytotoxic T lymphocytes cannot be inhibited by KIR2DL3 engagement. In double transgenic mice, Tg-KIR2DL3 × Tg-HLA-Cw3, no alteration of thymic differentiation could be documented. Immunization of double transgenic mice with Hen egg white lysozime (HEL) or Pigeon Cytochrome-C (PCC) was indistinguishable from immunization of control mice, as judged by recall antigen-induced in vitro proliferation and TCR repertoire analysis. These results indicate that KIR effect on T cells varies upon cell activation stage and show unexpected complexity in the biological function of KIRs in vivo.

Stachyose-induced apoptosis of Caco-2 cells via the caspase-dependent mitochondrial pathway

2015 ◽  
Vol 6 (3) ◽  
pp. 765-771 ◽  
Author(s):  
Guidong Huang ◽  
Jian Mao ◽  
Zhongwei Ji ◽  
Aisikaer Ailati
Keyword(s):  
Colon Cancer ◽  
Cell Growth ◽  
Cancer Cell ◽  
Mitochondrial Pathway ◽  
Colon Cancer Cell ◽  
Cancer Cell Growth ◽  
Induced Apoptosis

Some studies have shown that stachyose, as prebiotics, can prevent indirectly colon cancer cell growth by promoting the proliferation of probiotics or producing beneficial materials in the intestine.

scholarly journals Roles of a Fimbrin and an α-Actinin-like Protein in Fission Yeast Cell Polarization and Cytokinesis

2001 ◽  
Vol 12 (4) ◽  
pp. 1061-1077 ◽  
Author(s):  
Jian-Qiu Wu ◽  
Jürg Bähler ◽  
John R. Pringle
Keyword(s):  
Fission Yeast ◽  
Protein Localization ◽  
Normal Growth ◽  
Growth Conditions ◽  
Cell Polarization ◽  
Dependent Manner ◽  
Cortical Actin ◽  
Ring Assembly ◽  
Or Organization

Eukaryotic cells contain many actin-interacting proteins, including the α-actinins and the fimbrins, both of which have actin cross-linking activity in vitro. We report here the identification and characterization of both an α-actinin-like protein (Ain1p) and a fimbrin (Fim1p) in the fission yeast Schizosaccharomyces pombe. Ain1p localizes to the actomyosin-containing medial ring in an F-actin–dependent manner, and the Ain1p ring contracts during cytokinesis. ain1 deletion cells have no obvious defects under normal growth conditions but display severe cytokinesis defects, associated with defects in medial-ring and septum formation, under certain stress conditions. Overexpression of Ain1p also causes cytokinesis defects, and the ain1 deletion shows synthetic effects with other mutations known to affect medial-ring positioning and/or organization. Fim1p localizes both to the cortical actin patches and to the medial ring in an F-actin–dependent manner, and several lines of evidence suggest that Fim1p is involved in polarization of the actin cytoskeleton. Although a fim1deletion strain has no detectable defect in cytokinesis, overexpression of Fim1p causes a lethal cytokinesis defect associated with a failure to form the medial ring and concentrate actin patches at the cell middle. Moreover, an ain1 fim1 double mutant has a synthetical-lethal defect in medial-ring assembly and cell division. Thus, Ain1p and Fim1p appear to have an overlapping and essential function in fission yeast cytokinesis. In addition, protein-localization and mutant-phenotype data suggest that Fim1p, but not Ain1p, plays important roles in mating and in spore formation.

scholarly journals Elevated pressure enhanced TRAIL-induced apoptosis in hepatocellular carcinoma cells via ERK1/2-inactivation

2015 ◽  
Vol 20 (4) ◽  
Author(s):  
Eunyoung Hong ◽  
Eunil Lee ◽  
Joonhee Kim ◽  
Daeho Kwon ◽  
Yongchul Lim
Keyword(s):  
Specific Inhibitor ◽  
Underlying Mechanism ◽  
Elevated Pressure ◽  
Mitochondrial Pathway ◽  
Carcinoma Cells ◽  
Intrinsic Resistance ◽  
Hep3b Cells ◽  
Induced Apoptosis

AbstractThe high frequency of intrinsic resistance to TNF-related apoptosisinducing ligand (TRAIL) in tumor cell lines has necessitated the development of strategies to sensitize tumors to TRAIL-induced apoptosis. We previously showed that elevated pressure applied as a mechanical stressor enhanced TRAIL-mediated apoptosis in human lung carcinoma cells in vitro and in vivo. This study focused on the effect of elevated pressure on the sensitization of TRAIL-resistant cells and the underlying mechanism. We observed elevated pressure-induced sensitization to TRAIL-mediated apoptosis in Hep3B cells, accompanied by the activation of several caspases and the mitochondrial signaling pathway. Interestingly, the enhanced apoptosis induced by elevated pressure was correlated with suppression of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) phosphorylation and CREB without any change to other MAPKs. Phosphorylation of Bcl-2-associated death promoter (BAD) also decreased, leading to inhibition of the mitochondrial pathway. To confirm whether the activation of pERK1/2 plays a key role in the TRAIL-sensitizing effect of elevated pressure, Hep3B cells were pre-treated with the ERK1/2-specific inhibitor PD98059 instead of elevated pressure. Co-treatment with PD98059 and TRAIL augmented TRAIL-induced apoptosis and decreased BAD phosphorylation. The inhibition of ERK1/2 activation by elevated pressure and PD98059 also reduced BH3 interacting-domain death agonist (BID), thereby amplifying apoptotic stress at the mitochondrial level. Our results suggest that elevated pressure enhances TRAIL-induced apoptosis of Hep3B cells via specific suppression of ERK1/2 activation among MAPKs.

Oxymatrine Extracted from Sophora flavescens Inhibited Cell Growth and Induced Apoptosis in Human Osteosarcoma MG-63 Cells In Vitro

2014 ◽  
Vol 70 (2) ◽  
pp. 1439-1444 ◽  
Author(s):  
Jianghua Wei ◽  
Yin Zhu ◽  
Gang Xu ◽  
Fan Yang ◽  
Zhe Guan ◽  
...  
Keyword(s):  
Cell Growth ◽  
Sophora Flavescens ◽  
Human Osteosarcoma ◽  
Induced Apoptosis

scholarly journals Triptolide induces caspase-dependent cell death mediated via the mitochondrial pathway in leukemic cells

Blood ◽  
2006 ◽  
Vol 108 (2) ◽  
pp. 630-637 ◽  
Author(s):  
Bing Z. Carter ◽  
Duncan H. Mak ◽  
Wendy D. Schober ◽  
Teresa McQueen ◽  
David Harris ◽  
...  
Keyword(s):  
Cell Death ◽  
Anticancer Agents ◽  
Chinese Herb ◽  
Mitochondrial Pathway ◽  
Leukemic Cells ◽  
Cytochrome C Release ◽  
Knock Out ◽  
Dependent Cell ◽  
Induced Apoptosis

Triptolide, a diterpenoid isolated from the Chinese herb Tripterygium wilfordii Hook.f, has shown antitumor activities in a broad range of solid tumors. Here, we examined its effects on leukemic cells and found that, at 100 nM or less, it potently induced apoptosis in various leukemic cell lines and primary acute myeloid leukemia (AML) blasts. We then attempted to identify its mechanisms of action. Triptolide induced caspase-dependent cell death accompanied by a significant decrease in XIAP levels. Forced XIAP overexpression attenuated triptolide-induced cell death. Triptolide also decreased Mcl-1 but not Bcl-2 and Bcl-XL levels. Bcl-2 overexpression suppressed triptolide-induced apoptosis. Further, triptolide induced loss of the mitochondrial membrane potential and cytochrome C release. Caspase-9 knock-out cells were resistant, while caspase-8–deficient cells were sensitive to triptolide, suggesting criticality of the mitochondrial but not the death receptor pathway for triptolide-induced apoptosis. Triptolide also enhanced cell death induced by other anticancer agents. Collectively, our results demonstrate that triptolide decreases XIAP and potently induces caspase-dependent apoptosis in leukemic cells mediated through the mitochondrial pathway at low nanomolar concentrations. The potent antileukemic activity of triptolide in vitro warrants further investigation of this compound for the treatment of leukemias and other malignancies.

scholarly journals Actinomycin V Induces Apoptosis Associated with Mitochondrial and PI3K/AKT Pathways in Human CRC Cells

Marine Drugs ◽  
2021 ◽  
Vol 19 (11) ◽  
pp. 599
Author(s):  
Shiqing Jiang ◽  
E Zhang ◽  
Hang Ruan ◽  
Jiahui Ma ◽  
Xingming Zhao ◽  
...  
Keyword(s):  
Mitochondrial Pathway ◽  
Potential Candidate ◽  
Cytochrome C Release ◽  
Pi3k Inhibitor Ly294002 ◽  
Mitochondria Membrane Potential ◽  
Pi3k Inhibition ◽  
Hct 116 ◽  
Hct 116 Cells ◽  
Induced Apoptosis

Actinomycin (Act) V, an analogue of Act D, presented stronger antitumor activity and less hepatorenal toxicity than Act D in our previous studies, which is worthy of further investigation. We hereby report that Act V induces apoptosis via mitochondrial and PI3K/AKT pathways in colorectal cancer (CRC) cells. Act V-induced apoptosis was characterized by mitochondrial dysfunction, with loss of mitochondria membrane potential (MMP) and cytochrome c release, which then activated cleaved caspase-9, cleaved caspase-3, and cleaved PARP, revealing that it was related to the mitochondrial pathway, and the apoptotic trendency can be reversed by caspase inhibitor Z-VAD-FMK. Furthermore, we proved that Act V significantly inhibited PI3K/AKT signalling in HCT-116 cells using cell experiments in vitro, and it also presented a potential targeted PI3Kα inhibition using computer docking models. Further elucidation revealed that it exhibited a 28-fold greater potency than the PI3K inhibitor LY294002 on PI3K inhibition efficacy. Taken together, Act V, as a superior potential replacement of Act D, is a potential candidate for inhibiting the PI3K/AKT pathway and is worthy of more pre-clinical studies in the therapy of CRC.

scholarly journals Oxidative stress-induced parkin misfolding, aggregation, and toxicity

2020 ◽  
Author(s):  
Martin Duennwald ◽  
Gary S. Shaw ◽  
Mohammad A. Esmaeili ◽  
Jane R. Rylett ◽  
Susanne Schmid ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Disulfide Bonds ◽  
Protein Misfolding ◽  
Protein Quality ◽  
Normal Growth ◽  
Growth Conditions ◽  
Cellular Protein ◽  
Loss Of Function ◽  
Underlying Mechanisms

Abstract Background: Excess oxidative stress and protein misfolding are major hallmarks of neurodegenerative disease, including Parkinson’s disease (PD). Mutations in the genes encoding the ubiquitin ligase parkin cause autosomal recessive juvenile forms of Parkinsonism by the loss of parkin function in mitochondrial homeostasis and cellular protein quality control, generally. Dysfunction of parkin might also contribute to sporadic forms of PD, yet the underlying mechanisms remain mostly unexplored. Methods: We obtained key results from studies in human PD brains, a mouse model, yeast, cultured neuronal cells, and in vitro biochemistry. Human postmortem Medial Temporal Gyrus tissue was fixed for immunohistochemistry. We performed biochemical analyses of protein lysates from human brain, mouse brain, yeast and cells to assess parkin modification by oxidative stress under normal growth conditions and more so under oxidative stress. Results: Our results reveal that oxidative stress damages parkin by inducing the formation of aberrant intra- and inter-molecular disulfide bonds, leading to parkin misfolding and inclusion formation, which is toxic to cells. We furthermore find that parkin is most severely oxidized in its active conformation. Conclusion: Collectively, our study identifies a mechanism by which protein oxidation can contribute to neurodegeneration in PD by combining loss of function with toxic gain of function mechanisms.

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