scholarly journals Androgen Receptor (AR) Pathophysiological Roles in Androgen Related Diseases in Skin, Metabolism Syndrome, Bone/Muscle and Neuron/Immune Systems: Lessons Learned from Mice Lacking AR in Specific Cells

2013 ◽  
Vol 11 (1) ◽  
pp. nrs.11001 ◽  
Author(s):  
Chawnshang Chang ◽  
Shuyuan Yeh ◽  
Soo Ok Lee ◽  
Ta-min Chang
Keyword(s):  
Androgen Receptor ◽  
Mouse Models ◽  
Bone Mineralization ◽  
Muscle Growth ◽  
Lessons Learned ◽  
Specific Cell ◽  
Cell Type ◽  
Vast Number ◽  
Tissue Specific

The androgen receptor (AR) is expressed ubiquitously and plays a variety of roles in a vast number of physiological and pathophysiological processes. Recent studies of AR knockout (ARKO) mouse models, particularly the cell type- or tissue-specific ARKO models, have uncovered many AR cell type- or tissue-specific pathophysiological roles in mice, which otherwise would not be delineated from conventional castration and androgen insensitivity syndrome studies. Thus, the AR in various specific cell types plays pivotal roles in production and maturation of immune cells, bone mineralization, and muscle growth. In metabolism, the ARs in brain, particularly in the hypothalamus, and the liver appear to participate in regulation of insulin sensitivity and glucose homeostasis. The AR also plays key roles in cutaneous wound healing and cardiovascular diseases, including atherosclerosis and abdominal aortic aneurysm. This article will discuss the results obtained from the total, cell type-, or tissue-specific ARKO models. The understanding of AR cell type- or tissue-specific physiological and pathophysiological roles using these in vivo mouse models will provide useful information in uncovering AR roles in humans and eventually help us to develop better therapies via targeting the AR or its downstream signaling molecules to combat androgens/AR-related diseases.

scholarly journals Tissue-Specific Transcriptional Targeting of a Replication-Competent Retroviral Vector

2002 ◽  
Vol 76 (24) ◽  
pp. 12783-12791 ◽  
Author(s):  
Christopher R. Logg ◽  
Aki Logg ◽  
Robert J. Matusik ◽  
Bernard H. Bochner ◽  
Noriyuki Kasahara
Keyword(s):  
Tumor Cells ◽  
Viral Vectors ◽  
High Efficiency ◽  
Leukemia Virus ◽  
Transduction Efficiency ◽  
Promoter Strength ◽  
Cell Type ◽  
Cell Type Specificity ◽  
Tissue Specific

ABSTRACT The inability of replication-defective viral vectors to efficiently transduce tumor cells in vivo has prevented the successful application of such vectors in gene therapy of cancer. To address the need for more efficient gene delivery systems, we have developed replication-competent retroviral (RCR) vectors based on murine leukemia virus (MLV). We have previously shown that such vectors are capable of transducing solid tumors in vivo with very high efficiency. While the natural requirement of MLV infection for cell division imparts a certain degree of specificity for tumor cells, additional means for confining RCR vector replication to tumor cells are desirable. Here, we investigated the parameters critical for successful tissue-specific transcriptional control of RCR vector replication by replacing various lengths of the MLV enhancer/promoter with sequences derived either from the highly prostate-specific probasin (PB) promoter or from a more potent synthetic variant of the PB promoter. We assessed the transcriptional specificity of the resulting hybrid long terminal repeats (LTRs) and the cell type specificity and efficiency of replication of vectors containing these LTRs. Incorporation of PB promoter sequences effectively restricted transcription from the LTR to prostate-derived cells and imparted prostate-specific RCR vector replication but required the stronger synthetic promoter and retention of native MLV sequences in the vicinity of the TATA box for optimal replicative efficiency and specificity. Our results have thus identified promoter strength and positioning within the LTR as important determinants for achieving both high transduction efficiency and strict cell type specificity in transcriptionally targeted RCR vectors.

scholarly journals New Approach Methods to Evaluate Health Risks of Air Pollutants: Critical Design Considerations for In Vitro Exposure Testing

2020 ◽  
Vol 17 (6) ◽  
pp. 2124 ◽  
Author(s):  
Jose Zavala ◽  
Anastasia N. Freedman ◽  
John T. Szilagyi ◽  
Ilona Jaspers ◽  
John F. Wambaugh ◽  
...  
Keyword(s):  
Air Pollution ◽  
Lessons Learned ◽  
Air Pollutant ◽  
In Vivo Studies ◽  
Design Parameters ◽  
Vast Number ◽  
New Approach ◽  
In Vitro Exposure

Air pollution consists of highly variable and complex mixtures recognized as major contributors to morbidity and mortality worldwide. The vast number of chemicals, coupled with limitations surrounding epidemiological and animal studies, has necessitated the development of new approach methods (NAMs) to evaluate air pollution toxicity. These alternative approaches include in vitro (cell-based) models, wherein toxicity of test atmospheres can be evaluated with increased efficiency compared to in vivo studies. In vitro exposure systems have recently been developed with the goal of evaluating air pollutant-induced toxicity; though the specific design parameters implemented in these NAMs-based studies remain in flux. This review aims to outline important design parameters to consider when using in vitro methods to evaluate air pollutant toxicity, with the goal of providing increased accuracy, reproducibility, and effectiveness when incorporating in vitro data into human health evaluations. This review is unique in that experimental considerations and lessons learned are provided, as gathered from first-hand experience developing and testing in vitro models coupled to exposure systems. Reviewed design aspects include cell models, cell exposure conditions, exposure chambers, and toxicity endpoints. Strategies are also discussed to incorporate in vitro findings into the context of in vivo toxicity and overall risk assessment.

scholarly journals Chorionic enhancer is dispensable for regulated expression of the human renin gene

2008 ◽  
Vol 294 (2) ◽  
pp. R279-R287 ◽  
Author(s):  
Xiyou Zhou ◽  
Curt D. Sigmund
Keyword(s):  
Cellular Localization ◽  
Artificial Chromosome ◽  
Convincing Evidence ◽  
Specific Cell ◽  
Specific Expression ◽  
Tissue Specific ◽  
Human Renin ◽  
Regulated Expression ◽  
Renin Gene

We tested the hypothesis that a transcriptional chorionic enhancer (CE), previously identified to increase human renin expression in choriodecidual cells is required to mediate tissue-specific, cell-specific, and regulated expression of human renin in transgenic mice. Recombineering was used to delete the CE upstream of the renin gene alone or in combination with the kidney enhancer (KE) in a large artificial chromosome construct containing the entire human renin gene and extensive flanking sequences. Deletion of the CE had no qualitative or quantitative effect on the tissue-specific expression of human renin, nor on the cellular localization of human renin in the kidney or placenta. Combined deletion of both the CE and KE caused a decrease in the level of renal renin expression consistent with the established role of the KE. We also considered the possibility that the CE is a downstream enhancer of the KiSS1 gene, which lies directly upstream of renin and is also expressed in the placenta. Deletion of the CE alone, or the CE and KE together, had no effect on the level of KiSS1 expression in the placenta. These data provide convincing evidence that the CE is silent in vivo, at least in the mouse. The absence of a phenotype caused by deletion of the CE is consistent with the observation that the sequence is not evolutionarily conserved.

scholarly journals Transit-amplifying cells coordinate changes in intestinal epithelial cell-type composition

2019 ◽  
Author(s):  
Laura E. Sanman ◽  
Ina W. Chen ◽  
Jake M. Bieber ◽  
Veronica Steri ◽  
Byron Hann ◽  
...  
Keyword(s):  
Quantitative Imaging ◽  
Cell Types ◽  
Culture Conditions ◽  
Tissue Cell ◽  
Specific Cell ◽  
Cell Type ◽  
Cell Type Composition ◽  
Type Composition ◽  
Coordinate Changes

AbstractRenewing tissues have the remarkable ability to continually produce both proliferative progenitor and specialized differentiated cell-types. How are complex milieus of microenvironmental signals interpreted to coordinate tissue cell-type composition? Here, we develop a high-throughput approach that combines organoid technology and quantitative imaging to address this question in the context of the intestinal epithelium. Using this approach, we comprehensively survey enteroid responses to individual and paired perturbations to eight epithelial signaling pathways. We uncover culture conditions that enrich for specific cell-types, including Lgr5+ stem and enteroendocrine cells. We analyze interactions between perturbations and dissect mechanisms underlying an unexpected mutual antagonism between EGFR and IL-4 signals. Finally, we show that, across diverse perturbations, modulating proliferation of transit-amplifying cells also consistently changes the composition of differentiated secretory and absorptive cell-types. This property is conserved in vivo and can arise from differential amplification of secretory and absorptive progenitor cells. Taken together, the observations highlight an underappreciated role for transit-amplifying cells in which proliferation of these short-lived progenitors provides a lineage-based mechanism for tuning differentiated cell-type composition.

scholarly journals Homeoproteins CDP and SATB1 Interact: Potential for Tissue-Specific Regulation

1999 ◽  
Vol 19 (7) ◽  
pp. 4918-4926 ◽  
Author(s):  
Jinqi Liu ◽  
Anna Barnett ◽  
Ellis J. Neufeld ◽  
Jaquelin P. Dudley
Keyword(s):  
T Cells ◽  
Dna Binding ◽  
Promoter Region ◽  
Cell Type ◽  
Tissue Specific ◽  
Specific Antisera ◽  
Mmtv Promoter ◽  
Specific Regulation

ABSTRACT Homeoproteins are known to participate in development and cell type specification. The homeoproteins CCAAT displacement protein (CDP) and special AT-rich sequence binding protein 1 (SATB1) have been shown to bind to nuclear matrix-associated regions and to act as repressors of many cellular genes. Moreover, binding of SATB1 to the mouse mammary tumor virus (MMTV) promoter region dramatically affects the tissue-specific transcription of this retrovirus. Because protein-protein interactions are a common means of regulating homeoprotein function, we tested whether SATB1 and CDP interact in vivo and in vitro. SATB1 interacted with CDP through its DNA-binding domain, as demonstrated by glutathione S-transferase (GST) pull-down assays. GST pull-down assays also showed that CDP associated with SATB1 through three of its four DNA-binding domains (CR1, CR2, and the homeodomain). SATB1-specific antisera, but not preimmune sera, precipitated CDP from nuclear extracts, and CDP-specific antisera precipitated SATB1 from the same extracts. Far-Western blotting detected interaction of SATB1 and CDP in several different tissue extracts. Association of purified SATB1 and CDP in vitro resulted in the inability of each protein to bind to DNA in gel retardation assays. CDP overexpression in cultured T cells led to a loss of detectable SATB1 binding to the MMTV promoter region, as measured by gel shift experiments. CDP overexpression also elevated MMTV long terminal repeat reporter gene activity in transient-transfection assays, a result consistent with neutralization of the SATB1 repressor function in T cells. SATB1 is very abundant in certain tissues, particularly thymus, whereas CDP is relatively ubiquitous, except in certain terminally differentiated cell types. Because of the tissue and cell type distribution of SATB1 and CDP, we propose that the SATB1-to-CDP ratio in different tissues is a novel mechanism for homeoproteins to control gene expression and differentiation in mammals.

scholarly journals Tissue-Specific and Inducer-Specific Differential Induction of ISG56 and ISG54 in Mice

2007 ◽  
Vol 81 (16) ◽  
pp. 8656-8665 ◽  
Author(s):  
Fulvia Terenzi ◽  
Christine White ◽  
Srabani Pal ◽  
Bryan R. G. Williams ◽  
Ganes C. Sen
Keyword(s):  
Cultured Cells ◽  
Cell Types ◽  
Type I Interferons ◽  
Specific Cell ◽  
Type I ◽  
Mrna Levels ◽  
Tissue Specific ◽  
Interferon Stimulated Genes ◽  
Differential Pattern

ABSTRACT The interferon-stimulated genes (ISGs) ISG56 and ISG54 are strongly induced in cultured cells by type I interferons (IFNs), viruses, and double-stranded RNA (dsRNA), which activate their transcription by various signaling pathways. Here we studied the stimulus-dependent induction of both genes in vivo. dsRNA, which is generated during virus infection, induced the expression of both genes in all organs examined. Induction was not seen in STAT1-deficient mice, indicating that dsRNA-induced gene expression requires endogenous IFN. We further examined the regulation of these ISGs in several organs from mice injected with dsRNA or IFN-β. Both ISG56 and ISG54 were widely expressed and at comparable levels. However, in organs isolated from mice injected with IFN-α the expression of ISG54 was reduced and more restricted in distribution compared with the expression level and distribution of ISG56. When we began to study specific cell types, splenic B cells showed ISG54 but not ISG56 expression in response to all agonists. Finally, in livers isolated from mice infected with vesicular stomatitis virus, the expression of ISG56, but not ISG54, was induced; this difference was observed at both protein and mRNA levels. These studies have revealed unexpected complexity in IFN-stimulated gene induction in vivo. For the first time we showed that the two closely related genes are expressed in a tissue-specific and inducer-specific manner. Furthermore, our findings provide the first evidence of a differential pattern of expression of ISG54 and ISG56 genes by IFN-α and IFN-β.

scholarly journals In vivo tissue-specific chromatin profiling in Drosophila melanogaster using GFP-tagged nuclei

Genetics ◽  
2021 ◽  
Author(s):  
Juan Jauregui-Lozano ◽  
Kimaya Bakhle ◽  
Vikki M Weake
Keyword(s):  
Drosophila Melanogaster ◽  
Cell Types ◽  
Chromatin Accessibility ◽  
Chromatin State ◽  
Specific Cell ◽  
Tissue Specific ◽  
Histone Marks ◽  
Chromatin Profiling ◽  
Photoreceptor Neurons

Abstract The chromatin landscape defines cellular identity in multicellular organisms with unique patterns of DNA accessibility and histone marks decorating the genome of each cell type. Thus, profiling the chromatin state of different cell types in an intact organism under disease or physiological conditions can provide insight into how chromatin regulates cell homeostasis in vivo. To overcome the many challenges associated with characterizing chromatin state in specific cell types, we developed an improved approach to isolate Drosophila melanogaster nuclei tagged with a GFPKASH protein. The perinuclear space-localized KASH domain anchors GFP to the outer nuclear membrane, and expression of UAS-GFPKASH can be controlled by tissue-specific Gal4 drivers. Using this protocol, we profiled chromatin accessibility using an improved version of Assay for Transposable Accessible Chromatin followed by sequencing (ATAC-seq), called Omni-ATAC. In addition, we examined the distribution of histone marks using Chromatin immunoprecipitation followed by sequencing (ChIP-seq) and Cleavage Under Targets and Tagmentation (CUT&Tag) in adult photoreceptor neurons. We show that the chromatin landscape of photoreceptors reflects the transcriptional state of these cells, demonstrating the quality and reproducibility of our approach for profiling the transcriptome and epigenome of specific cell types in Drosophila.

scholarly journals Tissue specific targeting of DNA nanodevices in a multicellular living organism

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Kasturi Chakraborty ◽  
Palapuravan Anees ◽  
Sunaina Surana ◽  
Simona Martin ◽  
Jihad Aburas ◽  
...  
Keyword(s):  
Living Organism ◽  
Cell Types ◽  
Specific Cell ◽  
Full Potential ◽  
Tissue Specific ◽  
C Elegans ◽  
Specific Targeting ◽  
Synthetic Receptor ◽  
Ligand Interactions

Nucleic acid nanodevices present great potential as agents for logic-based therapeutic intervention as well as in basic biology. Often, however, the disease targets that need corrective action are localized in specific organs and thus realizing the full potential of DNA nanodevices also requires ways to target them to specific cell-types in vivo. Here we show that by exploiting either endogenous or synthetic receptor-ligand interactions and by leveraging the biological barriers presented by the organism, we can target extraneously introduced DNA nanodevices to specific cell types in C. elegans, with sub-cellular precision. The amenability of DNA nanostructures to tissue-specific targeting in vivo significantly expands their utility in biomedical applications and discovery biology.

scholarly journals Cell Type-Specific Survey of Epigenetic Modifications by Tandem Chromatin Immunoprecipitation Sequencing

2017 ◽  
Author(s):  
Mari Mito ◽  
Mitsutaka Kadota ◽  
Kaori Tanaka ◽  
Yasuhide Furuta ◽  
Kuniya Abe ◽  
...  
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Cortical Neurons ◽  
Expression Profiles ◽  
Cell Types ◽  
Epigenetic Modifications ◽  
Specific Cell ◽  
Cell Type ◽  
Chromatin Immunoprecipitation Sequencing ◽  
Cell Type Specific

AbstractBackgroundThe nervous system of higher eukaryotes is composed of numerous types of neurons and glia that together orchestrate complex neuronal responses. However, this complex pool of cells typically poses analytical challenges in investigating gene expression profiles and their epigenetic basis for specific cell types. Here, we developed a novel method that enables cell type-specific analyses of epigenetic modifications using tandem chromatin immunoprecipitation sequencing (tChIP-Seq).ResultsFLAG-tagged histone H2B, a constitutive chromatin component, was first expressed in Camk2a-positive pyramidal cortical neurons and used to purify chromatin in a cell type-specific manner. Subsequent chromatin immunoprecipitation using antibodies against H3K4me3—an active promoter mark—allowed us to survey neuron-specific coding and non-coding transcripts. Indeed, tChIP-Seq identified hundreds of genes associated with neuronal functions and genes with unknown functions expressed in cortical neurons.ConclusionstChIP-Seq thus provides a versatile approach to investigating the epigenetic modifications of particular cell types in vivo.

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