scholarly journals IQGAP1 in Podosome /Invadosome is Involved in the Progression of Glioblastoma Multiforme Depending on the Tumor Status

Author(s):  
Deborah Rotoli ◽  
Natalia Pérez-Rodríguez ◽  
Manuel Morales ◽  
María Del Carmen Maeso ◽  
Julio Ávila ◽  
...  

Glioblastoma multiforme (GBM) is the most frequent and aggressive primary brain tumor. GBM is formed by a very heterogeneous astrocyte population, neurons, neovascularization and infiltrating myeloid cells (microglia and monocyte derived macrophages). The IQGAP1 scaffold protein interacts with components of the cytoskeleton, cell adhesion molecules, and several signaling molecules to regulate cell morphology and motility, cell cycle and other cellular functions. IQGAP1 overexpression and delocalization has been observed in several tumors, suggesting a role for this protein in cell proliferation, transformation and invasion. IQGAP1 has been identified as a marker of amplifying cancer cells in GBMs. To determine the involvement of IQGAP1 in the onco-biology of GBM, we performed immunohistochemical confocal microscopical analysis of the IQGAP1 protein in human GBM tissue samples using cell type-specific markers. IQGAP1 immunostaining and subcellular localization was heterogeneous; the protein was located in the plasma membrane and, at variable levels, in nucleus and/or cytosol). Moreover, IQGAP1 positive staining was found in podosome/invadopodia-like structures. IQGAP1+ staining was observed in neurons (Map2+ cells), in cancer stem cells (CSC; nestin+) and in several macrophages (CD31+ or Iba1+). Our results indicate that the IQGAP1 protein is involved in normal cell physiology and also in oncologic processes.

Author(s):  
Deborah Rotoli ◽  
Natalia Dolores Pérez-Rodríguez ◽  
Manuel Morales ◽  
María del Carmen Maeso ◽  
Julio Ávila ◽  
...  

Glioblastoma multiforme (GBM) is the most frequent and aggressive primary brain tumor. GBM is formed by a very heterogeneous astrocyte population, neurons, neovascularization and infiltrating myeloid cells (microglia and monocyte derived macrophages). The IQGAP1 scaffold protein interacts with components of the cytoskeleton, cell adhesion molecules, and several signalling molecules to regulate cell morphology and motility, cell cycle and other cellular functions. IQGAP1 overexpression and delocalization has been observed in several tumours, suggesting a role for this protein in cell proliferation, transformation and invasion. IQGAP1 has been identified as a marker of amplifying cancer cells in GBMs. To determine the involvement of IQGAP1 in the onco-biology of GBM, we performed immunohistochemical confocal microscopical analysis of the IQGAP1 protein in human GBM tissue samples using cell type-specific markers. IQGAP1 immunostaining and subcellular localization was heterogeneous; the protein was located in the plasma membrane and, at variable levels, in nucleus and/or cytosol. Moreover, IQGAP1 positive staining was found in podosome/invadopodia-like structures. IQGAP1+ staining was observed in neurons (Map2+ cells), in cancer stem cells (CSC; nestin+) and in several macrophages (CD31+ or Iba1+). Our results indicate that the IQGAP1 protein is involved in normal cell physiology and also in oncologic processes.


Author(s):  
Deborah Rotoli ◽  
Natalia Pérez-Rodríguez ◽  
Manuel Morales ◽  
María Del Carmen Maeso ◽  
Julio Ávila ◽  
...  

Glioblastoma multiforme (GBM) is the most frequent and aggressive primary brain tumor. GBM is formed by a very heterogeneous astrocyte population, neurons, neovascularization and infiltrating myeloid cells (microglia and monocyte derived macrophages). The IQGAP1 scaffold protein interacts with components of the cytoskeleton, cell adhesion molecules, and several signaling molecules to regulate cell morphology and motility, cell cycle and other cellular functions. IQGAP1 overexpression and delocalization has been observed in several tumors, suggesting a role for this protein in cell proliferation, transformation and invasion. IQGAP1 has been identified as a marker of amplifying cancer cells in GBMs. To determine the involvement of IQGAP1 in the onco-biology of GBM, we performed immunohistochemical confocal microscopic analysis of the IQGAP1 protein in human GBM tissue samples using cell type-specific markers. IQGAP1 immunostaining and subcellular localization was heterogeneous; the protein was located in the plasma membrane and, at variable levels, in nucleus and/or cytosol. Moreover, IQGAP1 positive staining was found in podosome/invadopodia-like structures. IQGAP1+ staining was observed in neurons (Map2+ cells), in cancer stem cells (CSC; nestin+) and in several macrophages (CD31+ or Iba1+). Our results indicate that the IQGAP1 protein is involved in normal cell physiology as well as oncologic processes.


2007 ◽  
Vol 18 (2) ◽  
pp. 646-657 ◽  
Author(s):  
Andrea J. Oestreich ◽  
Brian A. Davies ◽  
Johanna A. Payne ◽  
David J. Katzmann

The multivesicular body (MVB) sorting pathway impacts a variety of cellular functions in eukaryotic cells. Perhaps the best understood role for the MVB pathway is the degradation of transmembrane proteins within the lysosome. Regulation of cargo selection by this pathway is critically important for normal cell physiology, and recent advances in our understanding of this process have highlighted the endosomal sorting complexes required for transport (ESCRTs) as pivotal players in this reaction. To better understand the mechanisms of cargo selection during MVB sorting, we performed a genetic screen to identify novel factors required for cargo-specific selection by this pathway and identified the Mvb12 protein. Loss of Mvb12 function results in differential defects in the selection of MVB cargoes. A variety of analyses indicate that Mvb12 is a stable member of ESCRT-I, a heterologous complex involved in cargo selection by the MVB pathway. Phenotypes displayed upon loss of Mvb12 are distinct from those displayed by the previously described ESCRT-I subunits (vacuolar protein sorting 23, -28, and -37), suggesting a distinct function than these core subunits. These data support a model in which Mvb12 impacts the selection of MVB cargoes by modulating the cargo recognition capabilities of ESCRT-I.


2017 ◽  
Author(s):  
Sebastian Preissl ◽  
Rongxin Fang ◽  
Yuan Zhao ◽  
Ramya Raviram ◽  
Yanxiao Zhang ◽  
...  

ABSTRACTGenome-wide analysis of chromatin accessibility in primary tissues has uncovered millions of candidate regulatory sequences in the human and mouse genomes1–4. However, the heterogeneity of biological samples used in previous studies has prevented a precise understanding of the dynamic chromatin landscape in specific cell types. Here, we show that analysis of the transposase-accessible-chromatin in single nuclei isolated from frozen tissue samples can resolve cellular heterogeneity and delineate transcriptional regulatory sequences in the constituent cell types. Our strategy is based on a combinatorial barcoding assisted single cell assay for transposase-accessible chromatin5 and is optimized for nuclei from flash-frozen primary tissue samples (snATAC-seq). We used this method to examine the mouse forebrain at seven development stages and in adults. From snATAC-seq profiles of more than 15,000 high quality nuclei, we identify 20 distinct cell populations corresponding to major neuronal and non-neuronal cell-types in foetal and adult forebrains. We further define cell-type specific cis regulatory sequences and infer potential master transcriptional regulators of each cell population. Our results demonstrate the feasibility of a general approach for identifying cell-type-specific cis regulatory sequences in heterogeneous tissue samples, and provide a rich resource for understanding forebrain development in mammals.


Development ◽  
2011 ◽  
Vol 138 (8) ◽  
pp. 1583-1593 ◽  
Author(s):  
S. L. Blagg ◽  
S. E. Battom ◽  
S. J. Annesley ◽  
T. Keller ◽  
K. Parkinson ◽  
...  

2021 ◽  
Vol 22 (3) ◽  
pp. 1316
Author(s):  
Tünde Fekete ◽  
Dóra Bencze ◽  
Eduárd Bíró ◽  
Szilvia Benkő ◽  
Kitti Pázmándi

Cells utilize a diverse repertoire of cell surface and intracellular receptors to detect exogenous or endogenous danger signals and even the changes of their microenvironment. However, some cytosolic NOD-like receptors (NLR), including NLRX1, serve more functions than just being general pattern recognition receptors. The dynamic translocation between the cytosol and the mitochondria allows NLRX1 to interact with many molecules and thereby to control multiple cellular functions. As a regulatory NLR, NLRX1 fine-tunes inflammatory signaling cascades, regulates mitochondria-associated functions, and controls metabolism, autophagy and cell death. Nevertheless, literature data are inconsistent and often contradictory regarding its effects on individual cellular functions. One plausible explanation might be that the regulatory effects of NLRX1 are highly cell type specific and the features of NLRX1 mediated regulation might be determined by the unique functional activity or metabolic profile of the given cell type. Here we review the cell type specific actions of NLRX1 with a special focus on cells of the immune system. NLRX1 has already emerged as a potential therapeutic target in numerous immune-related diseases, thus we aim to highlight which regulatory properties of NLRX1 are manifested in disease-associated dominant immune cells that presumably offer promising therapeutic solutions to treat these disorders.


2019 ◽  
Author(s):  
Ekaterina Khrameeva ◽  
Ilia Kurochkin ◽  
Dingding Han ◽  
Patricia Guijarro ◽  
Sabina Kanton ◽  
...  

ABSTRACTIdentification of gene expression traits unique to the human brain sheds light on the mechanisms of human cognition. Here we searched for gene expression traits separating humans from other primates by analyzing 88,047 cell nuclei and 422 tissue samples representing 33 brain regions of humans, chimpanzees, bonobos, and macaques. We show that gene expression evolves rapidly within cell types, with more than two-thirds of cell type-specific differences not detected using conventional RNA sequencing of tissue samples. Neurons tend to evolve faster in all hominids, but non-neuronal cell types, such as astrocytes and oligodendrocyte progenitors, show more differences on the human lineage, including alterations of spatial distribution across neocortical layers.


2018 ◽  
Author(s):  
Sirui Liu ◽  
Ling Zhang ◽  
Hui Quan ◽  
Hao Tian ◽  
Luming Meng ◽  
...  

AbstractThe high-order chromatin structure plays a non-negligible role in gene regulation. However, the mechanism for the formation of different chromatin structures in different cells and the sequence dependence of this process remain to be elucidated. As the nucleotide distributions in human and mouse genomes are highly uneven, we identified CGI forest and prairie genomic domains based on CGI density, which better segregates genomic elements along the genome than GC content. The genome is then divided into two sequentially, epigenetically, and transcriptionally distinct regions. These two types of megabase-sized domains spatially segregate, but to a different extent in different cell types. Overall, the forests and prairies gradually segregate from each other in development, differentiation, and senescence. The multi-scale forest-prairie spatial intermingling is cell-type specific and increases in differentiation, thus helps define the cell identity. We propose that the phase separation of the 1D mosaic sequence in space, serving as a potential driving force, together with cell type specific epigenetic marks and transcription factors, shapes the chromatin structure in different cell types and renders them distinct genomic properties. The mosaicity of the genome manifested in terms of alternative forests and prairies of a species could be related to its biological processes such as differentiation, aging and body temperature control.


2020 ◽  
Author(s):  
Shunian Xiang ◽  
Travis Johnson ◽  
Tianhan Dong ◽  
Zhi Huang ◽  
Michael Cheng ◽  
...  

Abstract Background Alzheimer’s disease (AD) brains are characterized by progressive neuron loss and gliosis which involves mostly microglia and astrocytes. Comparative transcriptomic analysis on AD vs. normal brain tissues helps to identify key genes/pathways involved in AD initiation and progression. However, many such studies using bulk brain tissue samples have not considered cell composition changes in AD brains, which may lead to expression changes that are not due to transcriptional regulation. Methods Using five large transcriptomic datasets including 1,681 brain tissue samples (882 AD, 799 normal) in total, we first mined frequent co-expression network modules across them, then combined differential expression and differential co-expression analysis on the mined modules in AD versus normal brains. Integrated with cell type deconvolution analysis, we addressed the question of whether the module expression changes are due to altered cellular composition or transcriptional regulation. We then used four additional large AD/normal transcriptomic datasets to validate our findings. Results The integrative analysis revealed highly elevated expression level of microglia modules in AD without co-expression change. Decreased expression and elevated co-expression are observed for neuron modules in AD, while significant over-expression and co-expression perturbation are observed in astrocyte modules, all of which has not been previously reported. The expression levels of astrocyte modules also show the strongest correlation with the clinicopathological biomarkers among all cell type specific modules. Conclusion Further analysis indicated that the overall increased expression of the core microglia modules can be well explained by the increased microglia cell population in AD brains instead of bona fide microglia genes’ upregulation. In contrast, the decreased expression and perturbed co-expression in AD neuron modules are due to both neuron cell loss and expression regulation of neuronal pathways including differentially expressed transcription factors such as BCL6 and STAT3, which previous study was not able to identify from the shadow of the cellular composition change. Similarly, the strong changes in expression and co-expression in the astrocyte modules may be also due to a combinatory effect from astrogliosis and astrocyte gene activation in AD brains. In this work, we demonstrated that the combinatorial analyses not only provide a powerful approach to delineate the origin of transcriptomic changes in bulk tissue data, but also lead to a deeper understanding of genes in AD.


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