scholarly journals Vimentin provides the mechanical resilience required for amoeboid migration and protection of the nucleus

2019 ◽  
Author(s):  
Luiza Da Cunha Stankevicins ◽  
Marta Urbanska ◽  
Daniel AD. Flormann ◽  
Emmanuel Terriac ◽  
Zahra Mostajeran ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dendritic Cells ◽  
Cell Migration ◽  
Molecular Mechanisms ◽  
Cell Cortex ◽  
Dna Double Strand Breaks ◽  
Nuclear Positioning ◽  
Mechanical Stiffness

AbstractDendritic cells use amoeboid migration through constricted passages to reach the lymph nodes, and this homing function is crucial for immune responses. Amoeboid migration requires mechanical resilience, however, the underlying molecular mechanisms for this type of migration remain unknown. Because vimentin intermediate filaments (IFs) and microfilaments regulate adhesion-dependent migration in a bidirectional manner, we analyzed if they exert a similar control on amoeboid migration. Vimentin was required for cellular resilience, via a joint interaction between vimentin IFs and F-actin. Reduced actin mobility in the cell cortex of vimentin-reduced cells indicated that vimentin promotes Factin subunit exchange and dynamics. These mechano-dynamic alterations in vimentin-deficient dendritic cells impaired amoeboid migration in confined environments in vitro and blocked lymph node homing in mouse experiments in vivo. Correct nuclear positioning is important in confined amoeboid migration both to minimize resistance and to avoid DNA damage. Vimentin-deficiency also led to DNA double strand breaks in the compressed dendritic cells, pointing to a role of vimentin in nuclear positioning. Together, these observations show that vimentin IF-microfilament interactions provide both the specific mechano-dynamics required for dendritic cell migration and the protection the genome needs in compressed spaces.Summary statementVimentin — in joint action with actin — mediates the mechanical stiffness of cells required for amoeboid cell migration through confined spaces and protects the nucleus from DNA damage.

scholarly journals Vimentin provides target search efficiency and mechanical resilience for dendritic cell migration

2020 ◽  
Author(s):  
Luiza Da Cunha Stankevicins ◽  
M. Reza Shaebani ◽  
Doriane Vesperini ◽  
Marta Urbanska ◽  
Daniel A. D. Flormann ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Cell Migration ◽  
Dendritic Cell ◽  
Cell Stiffness ◽  
Search Efficiency ◽  
Mechanical Stiffness ◽  
Target Search ◽  
Dendritic Cell Migration

AbstractDendritic cells use amoeboid migration to pass through confined tissues to reach the lymph nodes, and this homing function is crucial for immune responses. The underlying mechanisms for this type of migration remain unknown. As vimentin intermediate filaments regulate adhesion-dependent migration, we analyzed whether they have a similar effect on amoeboid migration. We show that lack of vimentin impairs amoeboid migration in vitro in confined environments, and blocks lymph-node homing in mice in vivo. Importantly, we show that vimentin-deficient dendritic cells have a lower coupling factor between cell speed and persistence and reduced target search efficiency (e.g., finding a pathogen, or another cell). These data show that the characteristics of vimentin in its dynamic regulation of cell stiffness and load-bearing, and also elastic capacity, appear to explain the coupling between their migratory ability and search efficiency. Taken together, these data show that vimentin provides the specific mechano-dynamics required for dendritic cell migration and for efficient target searching.Summary statementVimentin contributes to the mechanical stiffness of cells required for amoeboid cell migration through confined spaces, and improves cell-search efficiency. Vimentin-deficient cells migrate more slowly and their migration speed is less coupled to persistence compared to control cells.

scholarly journals DNA double-strand break repair: a theoretical framework and its application

2016 ◽  
Vol 13 (114) ◽  
pp. 20150679 ◽  
Author(s):  
Philip J. Murray ◽  
Bart Cornelissen ◽  
Katherine A. Vallis ◽  
S. Jon Chapman
Keyword(s):  
Dna Damage ◽  
Auger Electron ◽  
Strand Break ◽  
Dna Double Strand Breaks ◽  
Dsb Repair ◽  
Histone H2ax ◽  
Dna Double Strand Break ◽  
A Cell

DNA double-strand breaks (DSBs) are formed as a result of genotoxic insults, such as exogenous ionizing radiation, and are among the most serious types of DNA damage. One of the earliest molecular responses following DSB formation is the phosphorylation of the histone H2AX, giving rise to γ H2AX. Many copies of γ H2AX are generated at DSBs and can be detected in vitro as foci using well-established immuno-histochemical methods. It has previously been shown that anti- γ H2AX antibodies, modified by the addition of the cell-penetrating peptide TAT and a fluorescent or radionuclide label, can be used to visualize and quantify DSBs in vivo . Moreover, when labelled with a high amount of the short-range, Auger electron-emitting radioisotope, 111 In, the amount of DNA damage within a cell can be increased, leading to cell death. In this report, we develop a mathematical model that describes how molecular processes at individual sites of DNA damage give rise to quantifiable foci. Equations that describe stochastic mean behaviours at individual DSB sites are derived and parametrized using population-scale, time-series measurements from two different cancer cell lines. The model is used to examine two case studies in which the introduction of an antibody (anti- γ H2AX-TAT) that targets a key component in the DSB repair pathway influences system behaviour. We investigate: (i) how the interaction between anti- γ H2AX-TAT and γ H2AX effects the kinetics of H2AX phosphorylation and DSB repair and (ii) model behaviour when the anti- γ H2AX antibody is labelled with Auger electron-emitting 111 In and can thus instigate additional DNA damage. This work supports the conclusion that DSB kinetics are largely unaffected by the introduction of the anti- γ H2AX antibody, a result that has been validated experimentally, and hence the hypothesis that the use of anti- γ H2AX antibody to quantify DSBs does not violate the image tracer principle. Moreover, it provides a novel model of DNA damage accumulation in the presence of Auger electron-emitting 111 In that is supported qualitatively by the available experimental data.

scholarly journals Acquired temozolomide resistance in MGMT-deficient glioblastoma cells is associated with regulation of DNA repair by DHC2

Brain ◽  
2019 ◽  
Vol 142 (8) ◽  
pp. 2352-2366 ◽  
Author(s):  
Guo-zhong Yi ◽  
Guanglong Huang ◽  
Manlan Guo ◽  
Xi’an Zhang ◽  
Hai Wang ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dna Methyltransferase ◽  
Molecular Mechanisms ◽  
Progression Free Survival ◽  
Recurrent Glioblastoma ◽  
Dna Lesions ◽  
Dna Repair Proteins

Abstract The acquisition of temozolomide resistance is a major clinical challenge for glioblastoma treatment. Chemoresistance in glioblastoma is largely attributed to repair of temozolomide-induced DNA lesions by O6-methylguanine-DNA methyltransferase (MGMT). However, some MGMT-deficient glioblastomas are still resistant to temozolomide, and the underlying molecular mechanisms remain unclear. We found that DYNC2H1 (DHC2) was expressed more in MGMT-deficient recurrent glioblastoma specimens and its expression strongly correlated to poor progression-free survival in MGMT promotor methylated glioblastoma patients. Furthermore, silencing DHC2, both in vitro and in vivo, enhanced temozolomide-induced DNA damage and significantly improved the efficiency of temozolomide treatment in MGMT-deficient glioblastoma. Using a combination of subcellular proteomics and in vitro analyses, we showed that DHC2 was involved in nuclear localization of the DNA repair proteins, namely XPC and CBX5, and knockdown of either XPC or CBX5 resulted in increased temozolomide-induced DNA damage. In summary, we identified the nuclear transportation of DNA repair proteins by DHC2 as a critical regulator of acquired temozolomide resistance in MGMT-deficient glioblastoma. Our study offers novel insights for improving therapeutic management of MGMT-deficient glioblastoma.

Dendritic cell-derived IL-2 production is regulated by IL-15 in humans and in mice

Blood ◽  
2005 ◽  
Vol 105 (2) ◽  
pp. 697-702 ◽  
Author(s):  
Sonia Feau ◽  
Valeria Facchinetti ◽  
Francesca Granucci ◽  
Stefania Citterio ◽  
David Jarrossay ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Molecular Mechanisms ◽  
Interleukin 2 ◽  
Adaptive Immune ◽  
Deficient Mice ◽  
Mouse System

Abstract Dendritic cells (DCs) are involved in the initiation and regulation of innate and adaptive immune responses. Several molecular mechanisms regulate these diverse DC functions, and we have previously reported that mouse dendritic cells (mDCs) can produce interleukin-2 (IL-2) in vitro and in vivo, in response to microbial activation and T-cell-mediated stimuli. This property is shared by different DC subtypes, including Langerhans cells. Here we show that, on appropriate stimulation, human DCs, both plasmacytoid and myeloid subtypes, also express IL-2. Interestingly, the production of IL-2 by myeloid DCs is induced by T-cell-mediated stimuli and depends on the presence of IL-15. The key role of this cytokine in regulating IL-2 production was also confirmed in the mouse system. In particular, we could show that DCs from IL-15-deficient mice were strongly impaired in the ability to produce IL-2 after interactions with different microbial stimuli. Our results indicate that DC-produced IL-2 is tightly coregulated with the expression of IL-15.

Role of GADD153 (growth arrest- and DNA damage-inducible gene 153) in vascular smooth muscle cell apoptosis

2001 ◽  
Vol 100 (3) ◽  
pp. 275-281 ◽  
Author(s):  
Michiya IGASE ◽  
Takafumi OKURA ◽  
Michitsugu NAKAMURA ◽  
Yasunori TAKATA ◽  
Yutaka KITAMI ◽  
...  
Keyword(s):  
Dna Damage ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Molecular Mechanisms ◽  
Growth Arrest ◽  
Cell Contact ◽  
Inducible Gene

GADD153 (growth arrest- and DNA damage-inducible gene 153) is expressed at very low levels in growing cells, but is markedly induced in response to a variety of cellular stresses, including glucose deprivation, exposure to genotoxic agents and other growth-arresting situations. Forced expression of GADD153 induces cell cycle arrest in many types of cells. It is also reported that GADD153 is directly associated with apoptosis. Recently we have reported that platelet-derived growth factor (PDGF)-BB induces apoptosis in cultured vascular smooth muscle cells (VSMC), but only when 100% confluency is reached. These results suggested that cell–cell contact inhibition (cell growth arrest) may be a critical factor for induction of VSMC apoptosis by PDGF-BB. In the present study, we explored the role of GADD153, one of a number of growth-arrest-related gene products, in the molecular mechanisms of VSMC apoptosis in vitro and in vivo. GADD153 was markedly induced at both the mRNA and protein levels, in parallel with the induction of VSMC apoptosis, after treatment with PDGF-BB. Moreover, overexpression of GADD153 in VSMC significantly reduced cell viability and induced apoptosis. In the carotid artery balloon injury model in rats, GADD153 protein was expressed in apoptotic VSMC which were positively stained by in situ DNA labelling. These results demonstrate an important role for GADD153 in the molecular mechanisms of VSMC apoptosis.

scholarly journals Histone methyltransferase SET8 is regulated by miR-192/215 and induces oncogene-induced senescence via p53-dependent DNA damage in human gastric carcinoma cells

2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Xiaojing Zhang ◽  
Yin Peng ◽  
Yuan Yuan ◽  
Yuli Gao ◽  
Fan Hu ◽  
...  
Keyword(s):  
Dna Damage ◽  
Molecular Mechanisms ◽  
Biological Activities ◽  
Expression Profiles ◽  
Carcinoma Cells ◽  
Negative Regulator ◽  
Expression Change ◽  
Human Gastric Carcinoma Cells

Abstract Gastric cancer (GC) is the most common cancer throughout the world. Despite advances of the treatments, detailed oncogenic mechanisms are largely unknown. In our previous study, we investigated microRNA (miR) expression profiles in human GC using miR microarrays. We found miR-192/215 were upregulated in GC tissues. Then gene microarray was implemented to discover the targets of miR-192/215. We compared the expression profile of BGC823 cells transfected with miR-192/215 inhibitors, and HFE145 cells transfected with miR-192/-215 mimics, respectively. SET8 was identified as a proposed target based on the expression change of more than twofold. SET8 belongs to the SET domain-containing methyltransferase family and specifically catalyzes monomethylation of H4K20me. It is involved in diverse functions in tumorigenesis and metastasis. Therefore, we focused on the contributions of miR-192/215/SET8 axis to the development of GC. In this study, we observe that functionally, SET8 regulated by miR-192/215 is involved in GC-related biological activities. SET8 is also found to trigger oncogene-induced senescence (OIS) in GC in vivo and in vitro, which is dependent on the DDR (DNA damage response) and p53. Our findings reveal that SET8 functions as a negative regulator of metastasis via the OIS-signaling pathway. Taken together, we investigated the functional significance, molecular mechanisms, and clinical impact of miR-192/215/SET8/p53 in GC.

scholarly journals POGZ modulates the DNA damage response in a HP1-dependent manner

2021 ◽  
Author(s):  
John Heath ◽  
Estelle Simo Cheyou ◽  
Steven Findlay ◽  
Vincent Luo ◽  
Edgar Pinedo Carpio ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Dna Damage Response ◽  
Genome Stability ◽  
Dependent Manner ◽  
Dna Double Strand Breaks ◽  
Humoral Immune ◽  
Damage Response

The heterochromatin protein HP1 plays a central role in the maintenance of genome stability, in particular by promoting homologous recombination (HR)-mediated DNA repair. However, little is still known about how HP1 is controlled during this process. Here, we describe a novel function of the POGO transposable element derived with ZNF domain protein (POGZ) in the regulation of HP1 during the DNA damage response in vitro. POGZ depletion delays the resolution of DNA double-strand breaks (DSBs) and correlates with an increased sensitivity to different DNA damaging agents, including the clinically-relevant Cisplatin and Talazoparib. Mechanistically, POGZ promotes homology-directed DNA repair pathways by retaining the BRCA1/BARD1 complex at DSBs, in a HP1-dependent manner. In vivo CRISPR inactivation of Pogz is embryonic lethal and Pogz haplo-insufficiency (Pogz+/Δ) results in a developmental delay, a deficit in intellectual abilities, a hyperactive behaviour as well as a compromised humoral immune response in mice, recapitulating the main clinical features of the White Sutton syndrome (WHSUS). Importantly, Pogz+/Δ mice are radiosensitive and accumulate DSBs in diverse tissues, including the spleen and the brain. Altogether, our findings identify POGZ as an important player in homology-directed DNA repair both in vitro and in vivo, with clinical implications for the WHSUS.

Oligodendrocyte precursor (O-2A progenitor cell) migration; a model system for the study of cell migration in the developing central nervous system

Development ◽  
1993 ◽  
Vol 119 (Supplement) ◽  
pp. 219-225 ◽  
Author(s):  
B. W. Kiernan ◽  
Charles ffrench-Constant
Keyword(s):  
Nervous System ◽  
Cell Migration ◽  
Progenitor Cell ◽  
Molecular Mechanisms ◽  
Cultured Cells ◽  
Large Numbers ◽  
Multicellular Organisms ◽  
Developing Nervous System

Cell migration plays an important role in the development of complex multicellular organisms. The molecular mechanisms that regulate this migration arc therefore of great interest. Unfortunately, however, analysis of cell migration in vertebrates is hampered by the inaccessability of the cells and the difficulty of manipulating their environment within the embryo. This review focusses on one particular migratory cell population, the oligodendrocyte p1ecursor cell or O-2A progenitor cell, that gives rise to the myelin-forming oligodendrocytes within the CNS. These cells mi grate extensively during normal development. They can be purified and grown in large numbers in cell culture, so allowing the use of reductionist approaches using cell and molecular biology techniques. Moreover, cultured cells will migrate within the CNS following transplantation. As a result, the migration of these cells in vivo can be analysed following manipulation in vitro. Taken together, we believe that the different properties of these cells makes them excellent candidates for studies addressing the control of cell migration in the developing nervous system.

scholarly journals Atorvastatin Induction of VEGF and BDNF Promotes Brain Plasticity after Stroke in Mice

2005 ◽  
Vol 25 (2) ◽  
pp. 281-290 ◽  
Author(s):  
Jieli Chen ◽  
Chunling Zhang ◽  
Hao Jiang ◽  
Yi Li ◽  
Lijie Zhang ◽  
...  
Keyword(s):  
Cell Migration ◽  
Functional Recovery ◽  
Molecular Mechanisms ◽  
Brain Plasticity ◽  
Bdnf Expression ◽  
Atorvastatin Treatment ◽  
Adult Mice ◽  
Endothelial Growth Factor

Molecular mechanisms underlying the role of statins in the induction of brain plasticity and subsequent improvement of neurologic outcome after treatment of stroke have not been adequately investigated. Here, we use both in vivo and in vitro studies to investigate the potential roles of two prominent factors, vascular endothelial growth factor (VEGF) and brain-derived neurotrophic factor (BDNF), in mediating brain plasticity after treatment of stroke with atorvastatin. Treatment of stroke in adult mice with atorvastatin daily for 14 days, starting at 24 hours after MCAO, shows significant improvement in functional recovery compared with control animals. Atorvastatin increases VEGF, VEGFR2 and BDNF expression in the ischemic border. Numbers of migrating neurons, developmental neurons and synaptophysin-positive cells as well as indices of angiogenesis were significantly increased in the atorvastatin treatment group, compared with controls. In addition, atorvastatin significantly increased brain subventricular zone (SVZ) explant cell migration in vitro. Anti-BDNF antibody significantly inhibited atorvastatin-induced SVZ explant cell migration, indicating a prominent role for BDNF in progenitor cell migration. Mouse brain endothelial cell culture expression of BDNF and VEGFR2 was significantly increased in atorvastatin-treated cells compared with control cells. Inhibition of VEGFR2 significantly decreased expression of BDNF in brain endothelial cells. These data indicate that atorvastatin promotes angiogenesis, brain plasticity and enhances functional recovery after stroke. In addition, VEGF, VEGFR2 and BDNF likely contribute to these restorative processes.

PARP-1 inhibition prevents CNS migration of dendritic cells during EAE, suppressing the encephalitogenic response and relapse severity

2011 ◽  
Vol 17 (7) ◽  
pp. 794-807 ◽  
Author(s):  
Leonardo Cavone ◽  
Alessandra Aldinucci ◽  
Clara Ballerini ◽  
Tiziana Biagioli ◽  
Flavio Moroni ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Dendritic Cells ◽  
Molecular Mechanisms ◽  
Neurological Impairment ◽  
Mouse Bone Marrow ◽  
In Vivo Models ◽  
In Vitro Techniques ◽  
Parp 1

Background: Pharmacological inhibitors of poly(ADP-ribose) polymerase-1 (PARP-1) are currently evaluated in clinical trials for various malignancies but, interestingly, also proved of remarkable efficacy in preclinical models of autoimmune disorders including experimental autoimmune encephalomyelitis (EAE). Objectives: The objectives of the study were to determine molecular mechanisms underlying suppression of the encephalitogenic response by these drugs; likewise, whether clinically-relevant post-treatment paradigms with PARP-1 inhibitors could prevent EAE relapses. Methods: Adopted both in vitro techniques (bone marrow-derived cultured DC) as well as in vivo models of chronic or relapsing–remitting (RR) EAE. Results: We report that two structurally unrelated PARP-1 inhibitors negatively regulated NFκB activation, as well as maturation, cytokine production and APC function of cultured mouse bone marrow-derived dendritic cells (DCs). PARP-1 inhibitors also reduced the number and APC function of DCs migrating in the draining lymph nodes of ovalbumin-immunized mice. In C57Bl mice with chronic EAE or SJL mice with RR EAE, pharmacological inhibition of PARP-1 reduced CNS DC migration and demyelination as well as neurological impairment to an extent similar to that achieved with the potent immunosuppressant cyclosporine A. Remarkably, PARP-1 inhibitors injected after the first phase of disease reduced relapse incidence and severity, as well as the spinal cord number of autoreactive Th17 cells. Under this clinically-relevant treatment paradigm, PARP inhibitors also suppressed epitope spreading of the encephalitogenic response. Conclusions: Overall, data underscore the potential relevance of PARP-1 inhibitors to MS therapy and suppression of autoimmunity.

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