Notch signaling in response to excitotoxicity induces neurodegeneration via erroneous cell cycle reentry

AbstractGlomerular podocytes are integral members of the glomerular filtration barrier in the kidney and are crucial for glomerular permselectivity. These highly differentiated cells are vulnerable to an array of noxious stimuli that prevail in several glomerular diseases. Elevated circulating growth hormone (GH) levels are associated with podocyte injury and proteinuria in diabetes. However, the precise mechanism(s) by which excess GH elicits podocytopathy remains to be elucidated. Previous studies have shown that podocytes express GH receptor (GHR) and induce Notch signaling when exposed to GH. In the present study, we demonstrated that GH induces TGF-β1 signaling and provokes cell cycle reentry of otherwise quiescent podocytes. Though differentiated podocytes reenter the cell cycle in response to GH and TGF-β1, they cannot accomplish cytokinesis, despite karyokinesis. Owing to this aberrant cell cycle event, GH- or TGF-β1-treated cells remain binucleated and undergo mitotic catastrophe. Importantly, inhibition of JAK2, TGFBR1 (TGF-β receptor 1), or Notch prevented cell cycle reentry of podocytes and protected them from mitotic catastrophe associated with cell death. Inhibition of Notch activation prevents GH-dependent podocyte injury and proteinuria. Similarly, attenuation of GHR expression abated Notch activation in podocytes. Kidney biopsy sections from patients with diabetic nephropathy (DN) show activation of Notch signaling and binucleated podocytes. These data indicate that excess GH induced TGF-β1-dependent Notch1 signaling contributes to the mitotic catastrophe of podocytes. This study highlights the role of aberrant GH signaling in podocytopathy and the potential application of TGF-β1 or Notch inhibitors, as a therapeutic agent for DN.

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Andrographolide Inhibits Proliferation of Colon Cancer SW-480 Cells via Downregulating Notch Signaling Pathway.

Anti-Cancer Agents in Medicinal Chemistry ◽

10.2174/1871520620666200717143109 ◽

2020 ◽

Vol 20 ◽

Author(s):

Imran Khan ◽

Sadaf Mahfooz ◽

Mohd Saeed ◽

Irfan Ahmad ◽

Irfan A. Ansari

Keyword(s):

Cell Cycle ◽

Colon Cancer ◽

Notch Signaling ◽

Signaling Pathway ◽

Mtt Assay ◽

Annexin V ◽

Notch Signaling Pathway ◽

Phase Cell ◽

Ros Generation ◽

Notch 1

Background: Recently Notch signaling pathway has gained attention as a potential therapeutic target for chemotherapeutic intervention. However, the efficacy of previously known Notch inhibitors in colon cancer is still unclear. The purpose of this study was to investigate the effect of andrographolide on aberrantly activated Notch signaling in SW-480 cells in vitro. Methods: The cytostatic potential of andrographolide on SW-480 cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay, morphology assessment and colony formation assay. The apoptotic activity was evaluated by FITC Annexin V assay, 4′,6-diamidino-2-phenylindole (DAPI), Hoechst, Rhodamine 123 and Mito Tracker CMXRos staining. Scratch assay for migratory potential assessment. 7’-Dichlorodihydrofluorescein Diacetate (DCFH-DA) staining was used to evaluate the Reactive Oxygen Species (ROS) generation. Relative mRNA expression of Bax, Bcl2, NOTCH 1 and JAGGED 1 was estimated by Real-Time Quantitative Reverse Transcription PCR (qRT-PCR). Cell cycle phase distribution was evaluated Annexin V-FITC/PI staining. Results: MTT assay demonstrated dose and time dependent cytoxicity of andrographolide on SW-480 cells. It also inhibited the migratory and colony forming potential of SW-480 cells. Furthermore, andrographolide also showed disruption of mitochondrial membrane potential and induced apoptosis through nuclear condensation. Flow cytometric evaluation showed andrographolide enhanced early and late apoptotic cells and induced upregulation of proapoptotic (Bax and Bad) and downregulation of antiapoptotic Bcl2 in treated SW-480 cells. Andrographolide augmented intracellular ROS generation and induced G0/G1 phase cell cycle arrest in colon cancer SW480 cells. Furthermore, andrographolide repressed the Notch signaling by decreasing the expression of NOTCH 1 and JAGGED 1. Conclusion: Our findings suggested that andrographolide constraint the growth of SW-480 cells through the inhibition of Notch signaling pathway.

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A Comprehensive Bioinformatics Analysis of Notch Pathways in Bladder Cancer

Cancers ◽

10.3390/cancers13123089 ◽

2021 ◽

Vol 13 (12) ◽

pp. 3089

Author(s):

Chuan Zhang ◽

Mandy Berndt-Paetz ◽

Jochen Neuhaus

Keyword(s):

Cell Cycle ◽

Bladder Cancer ◽

Notch Signaling ◽

Epithelial Mesenchymal Transition ◽

Tumor Biology ◽

Disease Free Survival ◽

Mesenchymal Transition ◽

Expression Levels ◽

Notch Receptors ◽

Notch Pathways

Background: A hallmark of Notch signaling is its variable role in tumor biology, ranging from tumor-suppressive to oncogenic effects. Until now, the mechanisms and functions of Notch pathways in bladder cancer (BCa) are still unclear. Methods: We used publicly available data from the GTEx and TCGA-BLCA databases to explore the role of the canonical Notch pathways in BCa on the basis of the RNA expression levels of Notch receptors, ligands, and downstream genes. For statistical analyses of cancer and non-cancerous samples, we used R software packages and public databases/webservers. Results: We found differential expression between control and BCa samples for all Notch receptors (NOTCH1, 2, 3, 4), the delta-like Notch ligands (DLL1, 3, 4), and the typical downstream gene hairy and enhancer of split 1 (HES1). NOTCH2/3 and DLL4 can significantly differentiate non-cancerous samples from cancers and were broadly altered in subgroups. High expression levels of NOTCH2/3 receptors correlated with worse overall survival (OS) and shorter disease-free survival (DFS). However, at long-term (>8 years) follow-up, NOTCH2 expression was associated with a better OS and DFS. Furthermore, the cases with the high levels of DLL4 were associated with worse OS but improved DFS. Pathway network analysis revealed that NOTCH2/3 in particular correlated with cell cycle, epithelial–mesenchymal transition (EMT), numbers of lymphocyte subtypes, and modulation of the immune system. Conclusions: NOTCH2/3 and DLL4 are potential drivers of Notch signaling in BCa, indicating that Notch and associated pathways play an essential role in the progression and prognosis of BCa through directly modulating immune cells or through interaction with cell cycle and EMT.

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Interactions Between Genes From Aging Pathways Significantly Influence Risk of Alzheimer’s Disease

Innovation in Aging ◽

10.1093/geroni/igaa057.467 ◽

2020 ◽

Vol 4 (Supplement_1) ◽

pp. 142-143

Author(s):

Svetlana Ukraintseva ◽

Konstantin Arbeev ◽

Hongzhe Duan ◽

Igor Akushevich ◽

Mary Feitosa ◽

...

Keyword(s):

Cell Cycle ◽

Older Adults ◽

Risk Factor ◽

Human Aging ◽

Cell Responses ◽

Cell Cycle Reentry ◽

Universal Feature ◽

Igf I ◽

Ad Prevention ◽

Stress Damage

Abstract Age is major risk factor for AD; however, relationships between aging and AD are not well understood. Decline in physiological resilience is universal feature of human aging that may also play role in AD. Aging-related pathways (such as IGF-I/P53/mTOR-mediated) that are involved in tissue resilience work in concert to decide outcomes of cell responses to stress/damage, such as survival, apoptosis, autophagy, etc. We hypothesized that interplay among genes in these pathways may influence AD risk as result of epistasis (GxG). We estimated effects of pairwise epistasis between SNPs in 53 genes from respective pathways on AD risk in the LLFS compared with other data (HRS, CHS, LOADFS). We found significant (fdr<0.05) GxG effects on AD risk in older adults across datasets. The SNP rs11765954 in CDK6 gene was involved in top GxG effects on AD in all datasets, when paired with SNPs in BCL2 and PPARGC1A. The CDK6 role in AD could be pleiotropic, depending on its activity in neurons: CDK6 expression is needed for DNA repair and neuronal survival; however, CDK6 overexpression may lead to the cell cycle reentry in postmitotic neurons resulting in apoptosis, which may contribute to neurodegeneration. CDK6 was earlier found to interfere with BCL2 effects on apoptosis, and with PPARGC1A effects on energy metabolism, which might contribute to observed GxG between these genes. We conclude that interactions among genes from biologically connected aging pathways may significantly influence AD risk. Uncovering such GxG effects has a potential to yield new genetic targets for AD prevention/treatment.

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Abstract 2357: Src Kinase Inhibition Blocks Thrombin-induced Brain Injuries without Cognitive Side Effects

Stroke ◽

10.1161/str.43.suppl_1.a2357 ◽

2012 ◽

Vol 43 (suppl_1) ◽

Author(s):

Da-Zhi Liu ◽

Bradley P Ander ◽

Ali Izadi ◽

Ken Van ◽

Xinhua Zhan ◽

...

Keyword(s):

Cell Cycle ◽

Cognitive Deficits ◽

Neuronal Cell ◽

Thrombin Injection ◽

Cell Cycle Reentry ◽

Cell Cycle Inhibition ◽

Mature Neurons ◽

Cognitive Side Effects

Intracerebral hemorrhage (ICH) activates thrombin, a potent mitogen. Thrombin triggers mitosis by modulating several intracellular mitogenic molecules including Src family kinases. These molecules regulate mitogen-activated protein kinases (MAPKs) and cell cycle proteins such as cyclin-dependent kinases (Cdks); and play critical roles in mitogenic signaling pathways and cell cycle progression. Since aberrant cell cycle reentry results in death of mature neurons, cell cycle inhibition appears to be a candidate strategy for the treatment of neurological diseases including ICH. However, this can also block cell cycle (proliferation) of neural progenitor cells (NPCs) and thus impair brain neurogenesis leading to cognitive deficits. We hypothesized that inhibition of cell cycle by blocking mitogenic signaling molecules (i.e., Src family kinase members) blocks cell cycle reentry of mature neurons without injuring NPCs, which will avoid cognitive side effects during cell cycle inhibition treatment for ICH. Our data shows: (1) Thrombin 30U/ml results in apoptosis of mature neurons via neuronal cell cycle reentry in vitro ; (2) PP2 (Src family kinase inhibitor) 0.3 µM attenuates the thrombin-induced neuronal apoptosis via blocking neuronal cell cycle reentry, but does not affect the viability of NPCs at the same doses in vitro ; (3) Intracerebral ventricular thrombin injection (20U, i.c.v.) results in neuron loss in hippocampus and cognitive deficits 5 weeks after thrombin injection in vivo ; (4) PP2 (1mg/kg, i.p.), given immediately after thrombin injection (i.c.v.), blocks the thrombin-induced neuron loss in hippocampus and cognitive deficits, whereas PP2 on its own at the same doses does not affect normal cognition in vivo . These suggest that Src kinase inhibition prevents hippocampal neuron death via blocking neuronal cell cycle reentry after ICH, but does not affect survival of NPCs.

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Abstract 4830: The Effects of Stem Cells on C-Kit Up-Regulation and Cell-Cycle Reentry of Neonatal Cardiomyocytes are Mediated by IGF-1 Receptor Activation

Circulation ◽

10.1161/circ.118.suppl_18.s_945-d ◽

2008 ◽

Vol 118 (suppl_18) ◽

Author(s):

Xi-Yong Yu ◽

Yong-Jian Geng ◽

Xiao-Hong Li ◽

Chun-Yu Deng ◽

Shu-Guang Lin ◽

...

Keyword(s):

Cell Cycle ◽

Kinase Inhibitor ◽

Fold Increase ◽

Pi3 Kinase ◽

Myocardial Regeneration ◽

Akt Kinase ◽

Paracrine Effects ◽

Neonatal Cardiomyocytes ◽

Cell Cycle Reentry ◽

Secreted Factors

Mesenchymal stem cells (MSCs) contribute myocardial regeneration, and the beneficial effects may be mediated by paracrine factors produced by MSCs. C-kit positive neonatal cardiomyocytes (NCMs) contribute to myocardial regeneration, but they do not give a robust regenerative response since low expression of c-kit. Cell-cycle reentry of NCMs and insulin-like growth factor (IGF-1) improve myocardial function in infarcted hearts. MSCs and NCMs were prepared from Lewis rats, and cocultured in two chambers which allowed the diffusion of secreted factors from upper chamber to lower chamber, but prevented cell contacts. MSCs secreted significant amount of IGF-1 (159.6 ± 34.4 pg/ug DNA at 24 h, 285.3 ± 28.5 pg/ug DNA at 48 h, and 358.3 ± 39.9 pg/ug DNA at 72 h), whereas the amount of IGF-1 in conditioned medium from NCMs was undetectable assessed by IGF-1 ELISA. Using flow cytometry, we found that the secreted factors by MSCs increased c-kit protein expression, which was attenuated by IGF-1 receptor neutralizing antibody (IGF-1R Ab) and phosphatidylinositol 3 (PI3) kinase inhibitor LY 294002 (NCM vs MSC/NCM vs MSC/NCM+IGF-1R Ab vs MSC/NCM+ LY294002= 1.5 ± 0.6 % vs 5.5 ± 0.3 % vs 1.9 ± 0.6% vs 2.1 ± 0.5%) assessed by flow cytometry. The cytokinesis of NCMs was increased when cocultured with MSC analyzed by calcein fluorescence intensity (3.1 ± 0.5 fold increase, p<0.02). As determined by BrdU assay, the DNA synthesis of NCMs was significantly increased when cocultured with MSC compared to NCM alone (1.8 ± 0.3 fold increase at 48 h, 2.6 ± 0.2 fold increae at 72 h), which was attenuated by IGF-1R Ab and by PI3 kinase inhibitor. To confirm the paracrine effects of MSCs are mediated by IGF-1 signaling and PI3/Akt pathway, we performed in vitro Akt kinase assay using GSK-3 fusion protein as substrate, and found that co-culture system increased the activity of Akt kinase in NCMs, and the IGF-1R Ab and PI3 kinase inhibitor dose-dependent blocked the ability of co-culture system to increase Akt kinase activity. Our results demonstrate that the paracrine effects of MSC on c-kit up-regulation and cell-cycle reentry of NCM are mediated by IGF-1R activation through PI3 kinase/Akt - mediated pathway. These findings provide a new paradigm for the biological effects of IGF-1 on myocardial regeneration. This research has received full or partial funding support from the American Heart Association, AHA South Central Affiliate (Arkansas, New Mexico, Oklahoma & Texas).

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Hypoxia-induced myocardial regeneration

Journal of Applied Physiology ◽

10.1152/japplphysiol.00328.2017 ◽

2017 ◽

Vol 123 (6) ◽

pp. 1676-1681 ◽

Cited By ~ 15

Author(s):

Wataru Kimura ◽

Yuji Nakada ◽

Hesham A. Sadek

Keyword(s):

Oxidative Stress ◽

Cell Cycle ◽

Systolic Heart Failure ◽

Cardiac Regeneration ◽

Oxygen Metabolism ◽

Functional Improvement ◽

Cardiomyocyte Proliferation ◽

Mammalian Heart ◽

Cell Cycle Reentry ◽

And Oxidative Stress

The underlying cause of systolic heart failure is the inability of the adult mammalian heart to regenerate damaged myocardium. In contrast, some vertebrate species and immature mammals are capable of full cardiac regeneration following multiple types of injury through cardiomyocyte proliferation. Little is known about what distinguishes proliferative cardiomyocytes from terminally differentiated, nonproliferative cardiomyocytes. Recently, several reports have suggested that oxygen metabolism and oxidative stress play a pivotal role in regulating the proliferative capacity of mammalian cardiomyocytes. Moreover, reducing oxygen metabolism in the adult mammalian heart can induce cardiomyocyte cell cycle reentry through blunting oxidative damage, which is sufficient for functional improvement following myocardial infarction. Here we concisely summarize recent findings that highlight the role of oxygen metabolism and oxidative stress in cardiomyocyte cell cycle regulation, and discuss future therapeutic approaches targeting oxidative metabolism to induce cardiac regeneration.

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Linking Cell Cycle Reentry and DNA Damage in Neurodegeneration

Annals of the New York Academy of Sciences ◽

10.1111/j.1749-6632.2009.04105.x ◽

2009 ◽

Vol 1170 (1) ◽

pp. 674-679 ◽

Cited By ~ 13

Author(s):

Dohoon Kim ◽

Li-Huei Tsai

Keyword(s):

Cell Cycle ◽

Dna Damage ◽

Cell Cycle Reentry

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MAD2B-mediated cell cycle reentry of podocytes is involved in the pathogenesis of FSGS

International Journal of Biological Sciences ◽

10.7150/ijbs.62238 ◽

2021 ◽

Vol 17 (15) ◽

pp. 4396-4408

Author(s):

Dian Bao ◽

Hua Su ◽

Chun-Tao Lei ◽

Hui Tang ◽

Chen Ye ◽

...

Keyword(s):

Cell Cycle ◽

Cell Cycle Reentry

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Establishment of signaling interactions with cellular resolution for every cell cycle of embryogenesis

10.1101/285007 ◽

2018 ◽

Author(s):

Long Chen ◽

Vincy Wing Sze Ho ◽

Ming-Kin Wong ◽

Xiaotai Huang ◽

Lu-yan Chan ◽

...

Keyword(s):

Cell Cycle ◽

Notch Signaling ◽

Cell Lineage ◽

Cellular Interaction ◽

Cell Contact ◽

Contact Map ◽

C Elegans ◽

Cellular Resolution ◽

Signaling Interactions ◽

Lineage Analysis

AbstractIntercellular signaling interaction plays a key role in breaking fate symmetry during animal development. Identification of the signaling interaction at cellular resolution is technically challenging, especially in a developing embryo. Here we develop a platform that allows automated inference and validation of signaling interaction for every cell cycle of C. elegans embryogenesis. This is achieved by generation of a systems-level cell contact map that consists of 1,114 highly confident intercellular contacts by modeling analysis and is validated through cell membrane labeling coupled with cell lineage analysis. We apply the map to identify cell pairs between which a Notch signaling interaction takes place. By generating expression patterns for two ligands and two receptors of Notch signaling pathway with cellular resolution using automated expression profiling technique, we are able to refine existing and identify novel Notch interactions during C. elegans embryogenesis. Targeted cell ablation followed by cell lineage analysis demonstrates the roles of signaling interactions over cell division in breaking fate symmetry. We finally develop a website that allows online access to the cell-cell contact map for mapping of other signaling interaction in the community. The platform can be adapted to establish cellular interaction from any other signaling pathways.

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