Abstract 278: Metabolic Reprogramming is Essential for Cell Cycle Progression in Cardiomyocytes

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Riham Abouleisa ◽  
Lindsey McNally ◽  
Qinghui Ou ◽  
Krishna Choudhary ◽  
Reuben Thomas ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Single Cell ◽  
Cell Cycle Progression ◽  
Biosynthetic Pathway ◽  
Cyclin B1 ◽  
Metabolic Reprogramming ◽  
Cycle Progression ◽  
Pathway Activity ◽  
Nad Synthesis

Myocardial infarction causes irreversible loss of cardiomyocytes (CMs) and often leads to heart failure. To replace the lost cells, we identified a combination of cell-cycle regulators that induces stable cytokinesis in adult post-mitotic cells. Specifically, adenoviral overexpression of cyclin-dependent kinase 1 (CDK1), CDK4, cyclin B1, and cyclin D1 (collectively known as ‘four factors’, or simply 4F) induced cell division in ~15% of post-mitotic mouse, rat, and human CMs. Identifying the major roadblocks during the process of CM proliferation is a key for advancing this field. This was not possible before due to the lack of efficient methods to induce CM proliferation. The goal of the current study is to understand why a subpopulation of CMs divide while most CMs, despite expressing 4F, resist cell cycle reentry. To investigate transcriptional changes during cell cycle progression at the single cell level, we conducted temporal single cell RNAseq on 60-day-old matured hiPS-CMs infected with either LacZ (control) or 4F for 24, 48 and 72 h. We found a unique cell population that appears 48 h after infection with the 4F; this population was identified as the proliferating population and expressed high levels of cytokinesis genes (Ki67, Aurora Kinase A and B, E2F1, CDC20, ANLN, TK1, CCNA2, PLK1 and PCNA). Consistent with our published data, this population represents ~15% of the total CMs population expressing 4F. Compared with the quiescent population from the same sample, this unique population of proliferating CMs shows significant upregulation of the cell cycle program and major downregulation of mitochondrial electron transport chain genes. In line with these transcriptomic changes, hiPS-CMs had 50% lower rates of oxidative phosphorylation 48 h after 4F infection. Furthermore, in 4F-overexpressing iPS-CMs, stable isotope tracing demonstrated significantly higher enrichment of glucose-derived 13 C in NAD and UDP-HexNAc, suggesting activation of NAD synthesis and the hexosamine biosynthetic pathway. We conclude that proliferating CMs diminish catabolic pathway activity and augment biosynthetic pathway activity. The capacity of CM subpopulation to reprogram their metabolism is likely to facilitate their ability to complete cell division.

scholarly journals Predicting Individual Cell Division Events from Single-Cell ERK and Akt Dynamics

2021 ◽  
Author(s):  
Alan D Stern ◽  
Gregory R Smith ◽  
Luis C Santos ◽  
Deepraj Sarmah ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Single Cell ◽  
Cell Cycle Progression ◽  
Time Window ◽  
Single Cells ◽  
Machine Learning Algorithms ◽  
Cycle Progression ◽  
Restriction Point ◽  
Activity Dynamics

Predictive determinants of stochastic single-cell fates have been elusive, even for the well-studied mammalian cell cycle. What drives proliferation decisions of single cells at any given time? We monitored single-cell dynamics of the ERK and Akt pathways, critical cell cycle progression hubs and anti-cancer drug targets, and paired them to division events in the same single cells using the non-transformed MCF10A epithelial line. Following growth factor treatment, in cells that divide both ERK and Akt activities are significantly higher within the S-G2 time window (~8.5-40 hours). Such differences were much smaller in the pre-S-phase, restriction point window which is traditionally associated with ERK and Akt activity dependence, suggesting unappreciated roles for ERK and Akt in S through G2. Machine learning algorithms show that simple metrics of central tendency in this time window are most predictive for subsequent cell division; median ERK and Akt activities classify individual division events with an AUC=0.76. Surprisingly, ERK dynamics alone predict division in individual cells with an AUC=0.74, suggesting Akt activity dynamics contribute little to the decision driving cell division in this context. We also find that ERK and Akt activities are less correlated with each other in cells that divide. Network reconstruction experiments demonstrated that this correlation behavior was likely not due to crosstalk, as ERK and Akt do not interact in this context, in contrast to other transformed cell types. Overall, our findings support roles for ERK and Akt activity throughout the cell cycle as opposed to just before the restriction point, and suggest ERK activity dynamics are substantially more important than Akt activity dynamics for driving cell division in this non-transformed context. Single cell imaging along with machine learning algorithms provide a better basis to understand cell cycle progression on the single cell level.

scholarly journals Regulation of Cell Division in Bacteria by Monitoring Genome Integrity and DNA Replication Status

2019 ◽  
Vol 202 (2) ◽  
Author(s):  
Peter E. Burby ◽  
Lyle A. Simmons
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Division ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Genome Instability ◽  
Sos Response ◽  
Bacterial Cells ◽  
Cycle Progression ◽  
Content Type

ABSTRACT All organisms regulate cell cycle progression by coordinating cell division with DNA replication status. In eukaryotes, DNA damage or problems with replication fork progression induce the DNA damage response (DDR), causing cyclin-dependent kinases to remain active, preventing further cell cycle progression until replication and repair are complete. In bacteria, cell division is coordinated with chromosome segregation, preventing cell division ring formation over the nucleoid in a process termed nucleoid occlusion. In addition to nucleoid occlusion, bacteria induce the SOS response after replication forks encounter DNA damage or impediments that slow or block their progression. During SOS induction, Escherichia coli expresses a cytoplasmic protein, SulA, that inhibits cell division by directly binding FtsZ. After the SOS response is turned off, SulA is degraded by Lon protease, allowing for cell division to resume. Recently, it has become clear that SulA is restricted to bacteria closely related to E. coli and that most bacteria enforce the DNA damage checkpoint by expressing a small integral membrane protein. Resumption of cell division is then mediated by membrane-bound proteases that cleave the cell division inhibitor. Further, many bacterial cells have mechanisms to inhibit cell division that are regulated independently from the canonical LexA-mediated SOS response. In this review, we discuss several pathways used by bacteria to prevent cell division from occurring when genome instability is detected or before the chromosome has been fully replicated and segregated.

scholarly journals Analysis of Cell Cycle and Replication of Mouse Macrophages afterIn VivoandIn VitroCryptococcus neoformans Infection Using Laser Scanning Cytometry

2012 ◽  
Vol 80 (4) ◽  
pp. 1467-1478 ◽  
Author(s):  
Carolina Coelho ◽  
Lydia Tesfa ◽  
Jinghang Zhang ◽  
Johanna Rivera ◽  
Teresa Gonçalves ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Cytotoxic Effect ◽  
Laser Scanning ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Content Type ◽  
Cycle Arrest ◽  
Laser Scanning Cytometry

ABSTRACTWe investigated the outcome of the interaction ofCryptococcus neoformanswith murine macrophages using laser scanning cytometry (LSC). Previous results in our lab had shown that phagocytosis ofC. neoformanspromoted cell cycle progression. LSC allowed us to simultaneously measure the phagocytic index, macrophage DNA content, and 5-ethynyl-2′-deoxyuridine (EdU) incorporation such that it was possible to study host cell division as a function of phagocytosis. LSC proved to be a robust, reliable, and high-throughput method for quantifying phagocytosis. Phagocytosis ofC. neoformanspromoted cell cycle progression, but infected macrophages were significantly less likely to complete mitosis. Hence, we report a new cytotoxic effect associated with intracellularC. neoformansresidence that manifested itself in impaired cell cycle completion as a consequence of a block in the G2/M stage of the mitotic cell cycle. Cell cycle arrest was not due to increased cell membrane permeability or DNA damage. We investigated alveolar macrophage replicationin vivoand demonstrated that these cells are capable of low levels of cell division in the presence or absence ofC. neoformansinfection. In summary, we simultaneously studied phagocytosis, the cell cycle state of the host cell and pathogen-mediated cytotoxicity, and our results demonstrate a new cytotoxic effect ofC. neoformansinfection on murine macrophages: fungus-induced cell cycle arrest. Finally, we provide evidence for alveolar macrophage proliferationin vivo.

scholarly journals Developmental HCN channelopathy results in decreased neural progenitor proliferation and microcephaly in mice

2021 ◽  
Author(s):  
Anna Katharina Schlusche ◽  
Sabine Ulrike Vay ◽  
Niklas Kleinenkuhnen ◽  
Steffi Sandke ◽  
Rafael Campos-Martin ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Membrane Potential ◽  
Cell Cycle Progression ◽  
Cortical Development ◽  
General Mechanism ◽  
Hcn Channel ◽  
Cycle Progression ◽  
Channel Function ◽  
Stem And Progenitor Cells

ABSTRACTThe development of the cerebral cortex relies on the controlled division of neural stem and progenitor cells. The requirement for precise spatiotemporal control of proliferation and cell fate places a high demand on the cell division machinery, and defective cell division can cause microcephaly and other brain malformations. Cell-extrinsic and intrinsic factors govern the capacity of cortical progenitors to produce large numbers of neurons and glia within a short developmental time window. In particular, ion channels shape the intrinsic biophysical properties of precursor cells and neurons and control their membrane potential throughout the cell cycle. We found that hyperpolarization-activated cyclic nucleotide-gated cation (HCN)-channel subunits are expressed in mouse, rat, and human neural progenitors. Loss of HCN-channel function in rat neural stem cells impaired their proliferation by affecting the cell-cycle progression, causing G1 accumulation and dysregulation of genes associated with human microcephaly. Transgene-mediated, dominant-negative loss of HCN-channel function in the embryonic mouse telencephalon resulted in pronounced microcephaly. Together, our findings suggest a novel role for HCN-channel subunits as a part of a general mechanism influencing cortical development in mammals.Significance StatementImpaired cell cycle regulation of neural stem and progenitor cells can affect cortical development and cause microcephaly. During cell cycle progression, the cellular membrane potential changes through the activity of ion channels and tends to be more depolarized in proliferating cells. HCN channels, which mediate a depolarizing current in neurons and cardiac cells, are linked to neurodevelopmental diseases, also contribute to the control of cell-cycle progression and proliferation of neuronal precursor cells. In this study, HCN-channel deficiency during embryonic and fetal brain development resulted in marked microcephaly of mice designed to be deficient in HCN-channel function in dorsal forebrain progenitors. The findings suggest that HCN-channel subunits are part of a general mechanism influencing cortical development in mammals.

scholarly journals Regulation of cell cycle drivers by Cullin-RING ubiquitin ligases

2020 ◽  
Vol 52 (10) ◽  
pp. 1637-1651 ◽  
Author(s):  
Sang-Min Jang ◽  
Christophe E. Redon ◽  
Bhushan L. Thakur ◽  
Meriam K. Bahta ◽  
Mirit I. Aladjem
Keyword(s):  
Cell Cycle ◽  
Cell Division ◽  
Cell Cycle Progression ◽  
Ubiquitin Ligases ◽  
Anaphase Promoting Complex ◽  
Cycle Progression ◽  
Cellular Processes ◽  
Cellular Pathways ◽  
Regulation Of Cell Cycle ◽  
F Box Protein

Abstract The last decade has revealed new roles for Cullin-RING ubiquitin ligases (CRLs) in a myriad of cellular processes, including cell cycle progression. In addition to CRL1, also named SCF (SKP1-Cullin 1-F box protein), which has been known for decades as an important factor in the regulation of the cell cycle, it is now evident that all eight CRL family members are involved in the intricate cellular pathways driving cell cycle progression. In this review, we summarize the structure of CRLs and their functions in driving the cell cycle. We focus on how CRLs target key proteins for degradation or otherwise alter their functions to control the progression over the various cell cycle phases leading to cell division. We also summarize how CRLs and the anaphase-promoting complex/cyclosome (APC/C) ligase complex closely cooperate to govern efficient cell cycle progression.

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