scholarly journals A Cluster of Four Surface Antigen Genes Specifically Expressed in Bradyzoites, SAG2CDXY, Plays an Important Role in Toxoplasma gondii Persistence

2008 ◽  
Vol 76 (6) ◽  
pp. 2402-2410 ◽  
Author(s):  
Jeroen P. J. Saeij ◽  
Gustavo Arrizabalaga ◽  
John C. Boothroyd
Keyword(s):  
Toxoplasma Gondii ◽  
Surface Antigen ◽  
Chronic Infection ◽  
Cell Types ◽  
Firefly Luciferase ◽  
Specific Expression ◽  
Genes Encoding ◽  
Tandem Genes ◽  
Different Cell Types ◽  
The Brain

ABSTRACT Toxoplasma gondii is one of the most successful protozoan parasites of warm-blooded animals. Stage-specific expression of its surface molecules is thought to be key to its ability to establish chronic infection in immunocompetent animals. The rapidly dividing tachyzoite stage displays a different subset of family of surface antigen 1 (SAG1)-related sequences (SRSs) from that displayed by the encysted bradyzoite stage. It is possible that this switch is necessary to protect the bradyzoites against an immune response raised against the tachyzoite stage. Alternatively, it might be that bradyzoite SRSs evolved to facilitate invasion of different cell types, such as those found in the brain, where cysts develop, or the small intestine, where bradyzoites must enter after oral infection. Here we studied the function of a cluster of four tandem genes, encoding bradyzoite SRSs called SAG2C, -D, -X, and -Y. Using bioluminescence imaging of mice infected with parasites expressing firefly luciferase (FLUC) driven by the SAG2D promoter, we show stage conversion for the first time in living animals. A truncated version of the SAG2D promoter (SAG2Dmin) gave efficient expression of FLUC in both tachyzoites and bradyzoites, indicating that the bradyzoite specificity of the complete SAG2D promoter is likely due to an element(s) that normally suppresses expression in tachyzoites. Comparing mice infected with the wild type or a mutant where the SAG2CDXY cluster of genes has been deleted (ΔSAG2CDXY), we demonstrate that whereas ΔSAG2CDXY parasites are less capable of maintaining a chronic infection in the brain, they do not show a defect in oral infectivity.

scholarly journals MiR-7 in Cancer Development

Biomedicines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 325
Author(s):  
Petra Korać ◽  
Mariastefania Antica ◽  
Maja Matulić
Keyword(s):  
Cell Fate ◽  
Dominant Role ◽  
Tumor Development ◽  
Mrna Translation ◽  
Cell Types ◽  
Fine Tuning ◽  
Non Coding Rna ◽  
Tumor Types ◽  
Different Cell Types ◽  
The Brain

MicroRNAs (miRNAs) are short non-coding RNA involved in the regulation of specific mRNA translation. They participate in cellular signaling circuits and can act as oncogenes in tumor development, so-called oncomirs, as well as tumor suppressors. miR-7 is an ancient miRNA involved in the fine-tuning of several signaling pathways, acting mainly as tumor suppressor. Through downregulation of PI3K and MAPK pathways, its dominant role is the suppression of proliferation and survival, stimulation of apoptosis and inhibition of migration. Besides these functions, it has numerous additional roles in the differentiation process of different cell types, protection from stress and chromatin remodulation. One of the most investigated tissues is the brain, where its downregulation is linked with glioblastoma cell proliferation. Its deregulation is found also in other tumor types, such as in liver, lung and pancreas. In some types of lung and oral carcinoma, it can act as oncomir. miR-7 roles in cell fate determination and maintenance of cell homeostasis are still to be discovered, as well as the possibilities of its use as a specific biotherapeutic.

Differential expression of glutamate receptor genes (GluR1-5) in the rat retina

1992 ◽  
Vol 8 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Thomas E. Hughes ◽  
Irm Hermans-Borgmeyer ◽  
Steve Heinemann
Keyword(s):  
Glutamate Receptor ◽  
Amacrine Cells ◽  
Cell Types ◽  
Bipolar Cells ◽  
Inner Nuclear Layer ◽  
Dissociated Cells ◽  
Different Cell Types ◽  
The Brain ◽  
Overlapping Sets

AbstractThe recent isolation of at least five different cDNAs encoding functional subunits of glutamate receptors (GluR1 to GluR5) has revealed a diversity whose function is not understood. To learn more about how these different receptor subunits are used in the brain, we undertook an in situ hybridization study of the retina to define how the different glutamate receptor genes are expressed. We chose the retina because the glutamate sensitivities of its different cell types have been characterized, and these different neurons reside in different laminae.Hybridization of [35S]UTP-labeled cRNA probes with transverse sections and freshly dissociated cells reveals that all five receptor subunits are expressed in the retina. Hybridization signal is detected in different, but overlapping, sets of cells in the retina. GluR1, GluR2, and GluR5 are expressed by many somata, and GluR4 by a few, in the outer third of the inner nuclear layer, where the horizontal cells reside. Transcripts for GluR1, GluR2, and GluR5 are found in the somata within the middle third of the inner nuclear layer, which is where the bipolar cell somata are located, and GluR2 probes label freshly dissociated rod bipolar cells. All of the probes produce labeling over the cells at the inner edge of the inner nuclear layer, which are probably amacrine cells, as well as over the cell bodies in the ganglion cell layer.

scholarly journals Complex regulation and functional versatility of mammalian alpha- and beta-tubulin isotypes during the differentiation of testis and muscle cells.

1988 ◽  
Vol 106 (6) ◽  
pp. 2023-2033 ◽  
Author(s):  
S A Lewis ◽  
N J Cowan
Keyword(s):  
Cell Types ◽  
Beta Tubulin ◽  
Specific Expression ◽  
Alpha Tubulin ◽  
Tubulin Isotypes ◽  
Tubulin Isotype ◽  
A Cell ◽  
Complex Regulation ◽  
Carboxy Terminal ◽  
Different Cell Types

In the accompanying paper (Gu, W., S. A. Lewis, and N. J. Cowan. 1988. J. Cell Biol. 106: 2011-2022), we report the generation of three antisera, each of which uniquely recognizes a different mammalian alpha-tubulin isotype, plus a fourth antibody that distinguishes between microtubules containing the tyrosinated and nontyrosinated form of the only known mammalian alpha-tubulin gene product that lacks an encoded carboxy-terminal tyrosine residue. These sera, together with five sera we raised that distinguish among the known mammalian beta-tubulin isotypes, have been used to study patterns of tubulin isotype-specific expression in muscle and testis, two tissues in which characteristic developmental changes are accompanied by dramatic rearrangements in microtubule structures. As in the case of cells in culture, there is no evidence to suggest that there is subcellular sorting of different tubulin isotypes among different kinds of microtubule, even in a cell type (the developing spermatid) that simultaneously contains such functionally distinct structures as the manchette and the flagellum. On the other hand, the patterns of expression of the various tubulin isotypes show marked and distinctive differences in different cell types and, in at least one case, evidence is presented for regulation at the translational or posttranslational level. The significance of these observations is discussed in terms of the existence of the mammalian alpha- and beta-tubulin multigene families.

scholarly journals Molecular and morphological analysis of the developing nemertean brain indicates convergent evolution of complex brains in Spiralia

BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Ludwik Gąsiorowski ◽  
Aina Børve ◽  
Irina A. Cherneva ◽  
Andrea Orús-Alcalde ◽  
Andreas Hejnol
Keyword(s):  
Neural Development ◽  
Evolutionary Process ◽  
Cell Types ◽  
Major Elements ◽  
Brain Cell ◽  
Mushroom Bodies ◽  
Brain Anatomy ◽  
Last Common Ancestor ◽  
Specific Expression ◽  
The Brain

Abstract Background The brain anatomy in the clade Spiralia can vary from simple, commissural brains (e.g., gastrotrichs, rotifers) to rather complex, partitioned structures (e.g., in cephalopods and annelids). How often and in which lineages complex brains evolved still remains unclear. Nemerteans are a clade of worm-like spiralians, which possess a complex central nervous system (CNS) with a prominent brain, and elaborated chemosensory and neuroglandular cerebral organs, which have been previously suggested as homologs to the annelid mushroom bodies. To understand the developmental and evolutionary origins of the complex brain in nemerteans and spiralians in general, we investigated details of the neuroanatomy and gene expression in the brain and cerebral organs of the juveniles of nemertean Lineus ruber. Results In the juveniles, the CNS is already composed of all major elements present in the adults, including the brain, paired longitudinal lateral nerve cords, and an unpaired dorsal nerve cord, which suggests that further neural development is mostly related with increase in the size but not in complexity. The ultrastructure of the juvenile cerebral organ revealed that it is composed of several distinct cell types present also in the adults. The 12 transcription factors commonly used as brain cell type markers in bilaterians show region-specific expression in the nemertean brain and divide the entire organ into several molecularly distinct areas, partially overlapping with the morphological compartments. Additionally, several of the mushroom body-specific genes are expressed in the developing cerebral organs. Conclusions The dissimilar expression of molecular brain markers between L. ruber and the annelid Platynereis dumerilii indicates that the complex brains present in those two species evolved convergently by independent expansions of non-homologous regions of a simpler brain present in their last common ancestor. Although the same genes are expressed in mushroom bodies and cerebral organs, their spatial expression within organs shows apparent differences between annelids and nemerteans, indicating convergent recruitment of the same genes into patterning of non-homologous organs or hint toward a more complicated evolutionary process, in which conserved and novel cell types contribute to the non-homologous structures.

scholarly journals A Rare Case of Third Ventricular Glioblastoma

2021 ◽  
Author(s):  
Asmira Gacic ◽  
Hakija Beculic ◽  
Rasim Skomorac ◽  
Alma Efendic
Keyword(s):  
Spinal Cord ◽  
Glioblastoma Multiforme ◽  
Blood Vessels ◽  
Rare Case ◽  
Third Ventricle ◽  
Cell Types ◽  
The Third ◽  
Different Cell Types ◽  
Brain And Spinal Cord ◽  
The Brain

Glioblastoma, also known as glioblastoma multiforme, is an aggressive type of cancer that is made up of abnormal astrocytic cells, but also contain a mixture of different cell types (including blood vessels) and areas of necrosis. It is often seen in the brain and spinal cord, but glioblastomas are rarely found in the third ventricle. In this case, it was diagnosed in a 22-year-old male patient and we intended to draw

scholarly journals Cell type-specific biotin labeling in vivo resolves regional neuronal proteomic differences in mouse brain

2021 ◽  
Author(s):  
Sruti Rayaprolu ◽  
Sara Bitarafan ◽  
Ranjita Betarbet ◽  
Sydney N Sunna ◽  
Lihong Cheng ◽  
...  
Keyword(s):  
Mouse Brain ◽  
Neurological Diseases ◽  
Neuronal Cell ◽  
Cell Types ◽  
Proteomic Profiling ◽  
Cell Type ◽  
Specific Expression ◽  
Cell Type Specific ◽  
The Brain

Isolation and proteomic profiling of brain cell types, particularly neurons, pose several technical challenges which limit our ability to resolve distinct cellular phenotypes in neurological diseases. Therefore, we generated a novel mouse line that enables cell type-specific expression of a biotin ligase, TurboID, via Cre-lox strategy for in vivo proximity-dependent biotinylation of proteins. Using adenoviral-based and transgenic approaches, we show striking protein biotinylation in neuronal cell bodies and axons throughout the mouse brain. We quantified more than 2,000 neuron-derived proteins following enrichment that mapped to numerous subcellular compartments. Synaptic, transmembrane transporters, ion channel subunits, and disease-relevant druggable targets were among the most significantly enriched proteins. Remarkably, we resolved brain region-specific proteomic profiles of Camk2a neurons with distinct functional molecular signatures and disease associations that may underlie regional neuronal vulnerability. Leveraging the neuronal specificity of this in vivo biotinylation strategy, we used an antibody-based approach to uncover regionally unique patterns of neuron-derived signaling phospho-proteins and cytokines, particularly in the cortex and cerebellum. Our work provides a proteomic framework to investigate cell type-specific mechanisms driving physiological and pathological states of the brain as well as complex tissues beyond the brain.

scholarly journals S100A6 and Its Brain Ligands in Neurodegenerative Disorders

2020 ◽  
Vol 21 (11) ◽  
pp. 3979
Author(s):  
Anna Filipek ◽  
Wiesława Leśniak
Keyword(s):  
Mammalian Cells ◽  
Brain Structures ◽  
Cell Types ◽  
Cytoskeletal Organization ◽  
High Level ◽  
S100a6 Protein ◽  
Different Cell Types ◽  
The Brain ◽  
Lateral Sclerosis

The S100A6 protein is present in different mammalian cells and tissues including the brain. It binds Ca2+ and Zn2+ and interacts with many target proteins/ligands. The best characterized ligands of S100A6, expressed at high level in the brain, include CacyBP/SIP and Sgt1. Research concerning the functional role of S100A6 and these two ligands indicates that they are involved in various signaling pathways that regulate cell proliferation, differentiation, cytoskeletal organization, and others. In this review, we focused on the expression/localization of these proteins in the brain and on their possible role in neurodegenerative diseases. Published results demonstrate that S100A6, CacyBP/SIP, and Sgt1 are expressed in various brain structures and in the spinal cord and can be found in different cell types including neurons and astrocytes. When it comes to their possible involvement in nervous system pathology, it is evident that their expression/level and/or subcellular localization is changed when compared to normal conditions. Among diseases in which such changes have been observed are Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), epileptogenesis, Parkinson’s disease (PD), Huntington’s disease (HD), and others.

scholarly journals Proteomic and transcriptomic analyses of early and late-chronic Toxoplasma gondii infection shows novel and stage specific transcripts

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Andrew L. Garfoot ◽  
Gary M. Wilson ◽  
Joshua J. Coon ◽  
Laura J. Knoll
Keyword(s):  
Toxoplasma Gondii ◽  
Chronic Infection ◽  
Time Course ◽  
Protozoan Pathogen ◽  
Toxoplasma Gondii Infection ◽  
High Level ◽  
Protein Rich ◽  
The Brain ◽  
Unique Ability

Abstract Background The protozoan pathogen Toxoplasma gondii has the unique ability to develop a chronic infection in the brain of its host by transitioning from the fast growing tachyzoite morphology to latent bradyzoite morphology. A hallmark of the bradyzoite is the development of neuronal cysts that are resilient against host immune response and current therapeutics. The bradyzoite parasites within the cyst have a carbohydrate and protein-rich wall and a slow-replication cycle, allowing them to remain hidden from the host. The intracellular, encysted lifestyle of T. gondii has made them recalcitrant to molecular analysis in vivo. Results Here, we detail the results from transcriptional and proteomic analyses of bradyzoite-enriched fractions isolated from mouse brains infected with T. gondii over a time course of 21 to 150 days. The enrichment procedure afforded consistent identification of over 2000 parasitic peptides from the mixed-organism sample, representing 366 T. gondii proteins at 28, 90, and 120 day timepoints. Deep sequencing of transcripts expressed during these three timepoints revealed that a subpopulation of genes that are transcriptionally expressed at a high level. Approximately one-third of these transcripts are more enriched during bradyzoite conditions compared to tachyzoites and approximately half are expressed at similar levels during each phase. The T. gondii transcript which increased the most over the course of chronic infection, sporoAMA1, shows stage specific isoform expression of the gene. Conclusions We have expanded the transcriptional profile of in vivo bradyzoites to 120 days post-infection and provided the first in vivo proteomic profile of T. gondii bradyzoites. The RNA sequencing depth of in vivo bradyzoite T. gondii was over 250-fold greater than previous reports and allowed us to identify low level transcripts and a novel bradyzoite-specific isoform of sporoAMA1.

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