scholarly journals Epidermal expression of a sterol biosynthesis gene regulates root growth by a non-cell autonomous mechanism in Arabidopsis

2017 ◽  
Author(s):  
Eleri Short ◽  
Margaret Pullen ◽  
Gul Imriz ◽  
Dongbin Liu ◽  
Naomi Cope-Selby ◽  
...  
Keyword(s):  
Root Meristem ◽  
Sterol Biosynthesis ◽  
Cellular Functions ◽  
Radial Patterning ◽  
Cell Type Specific ◽  
Epidermis Cell ◽  
A Site ◽  
Auxin Efflux Carriers ◽  
Epidermal Expression ◽  
Phenotypic Rescue

AbstractThe epidermis has been hypothesized to play a signalling role during plant development. One class of mutants showing defects in signal transduction and radial patterning are those in sterol biosynthesis. The expectation is that sterol biosynthesis is a constitutive cell-autonomous process for the maintenance of basic cellular functions. The HYDRA1 (HYD1) gene of Arabidopsis encodes an essential sterol Δ8-Δ7 isomerase, and although hyd1 mutant seedlings are defective in radial patterning of several tissues, we show that the HYD1 gene is expressed primarily in the root epidermis. Cell type-specific transgenic activation of HYD1 transcription reveals that HYD1 expression in the epidermis of hyd1 null mutants is sufficient to rescue root patterning and growth. Unexpectedly, expression of HYD1 in the vascular tissues and root meristem, though not endodermis or pericycle, also leads to phenotypic rescue. Phenotypic rescue is associated with rescued patterning of the PIN1 and PIN2 auxin efflux carriers. The importance of the epidermis is in part due to its role as a site for tissue-specific sterol biosynthesis, and auxin is a candidate for a non-cell autonomous signal.

scholarly journals Internalization of Foldamer-Based DNA Mimics through a Site-Specific Antibody Conjugate to Target HER2-Positive Cancer Cells

2021 ◽  
Vol 14 (7) ◽  
pp. 624
Author(s):  
Valentina Corvaglia ◽  
Imène Ait Mohamed Amar ◽  
Véronique Garambois ◽  
Stéphanie Letast ◽  
Aurélie Garcin ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Topoisomerase I ◽  
Ovarian Cancer Cells ◽  
Cellular Functions ◽  
Antibody Drug Conjugate ◽  
Her2 Positive ◽  
Dna Topoisomerase ◽  
Antibody Conjugate ◽  
A Site

Inhibition of protein–DNA interactions represents an attractive strategy to modulate essential cellular functions. We reported the synthesis of unique oligoamide-based foldamers that adopt single helical conformations and mimic the negatively charged phosphate moieties of B-DNA. These mimics alter the activity of DNA interacting enzymes used as targets for cancer treatment, such as DNA topoisomerase I, and they are cytotoxic only in the presence of a transfection agent. The aim of our study was to improve internalization and selective delivery of these highly charged molecules to cancer cells. For this purpose, we synthesized an antibody-drug conjugate (ADC) using a DNA mimic as a payload to specifically target cancer cells overexpressing HER2. We report the bioconjugation of a 16-mer DNA mimic with trastuzumab and its functional validation in breast and ovarian cancer cells expressing various levels of HER2. Binding of the ADC to HER2 increased with the expression of the receptor. The ADC was internalized into cells and was more efficient than trastuzumab at inhibiting their growth in vitro. These results provide proof of concept that it is possible to site-specifically graft high molecular weight payloads such as DNA mimics onto monoclonal antibodies to improve their selective internalization and delivery in cancer cells.

scholarly journals Epidermal expression of a sterol biosynthesis gene regulates root growth by a non-cell-autonomous mechanism inArabidopsis

Development ◽  
2018 ◽  
Vol 145 (10) ◽  
pp. dev160572 ◽  
Author(s):  
Eleri Short ◽  
Margaret Leighton ◽  
Gul Imriz ◽  
Dongbin Liu ◽  
Naomi Cope-Selby ◽  
...  
Keyword(s):  
Root Growth ◽  
Sterol Biosynthesis ◽  
Biosynthesis Gene ◽  
Epidermal Expression

scholarly journals A genomic view of estrogen actions in human breast cancer cells by expression profiling of the hormone-responsive transcriptome

2004 ◽  
Vol 32 (3) ◽  
pp. 719-775 ◽  
Author(s):  
L Cicatiello ◽  
C Scafoglio ◽  
L Altucci ◽  
M Cancemi ◽  
G Natoli ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Human Breast Cancer ◽  
Gene Activation ◽  
Chromosome 17 ◽  
Human Breast ◽  
Cellular Functions ◽  
Extracellular Milieu ◽  
Similar Expression Profile ◽  
A Site ◽  
Turn Over

Estrogen controls key cellular functions of responsive cells including the ability to survive, replicate, communicate and adapt to the extracellular milieu. Changes in the expression of 8400 genes were monitored here by cDNA microarray analysis during the first 32 h of human breast cancer (BC) ZR-75.1 cell stimulation with a mitogenic dose of 17beta-estradiol, a timing which corresponds to completion of a full mitotic cycle in hormone-stimulated cells. Hierarchical clustering of 344 genes whose expression either increases or decreases significantly in response to estrogen reveals that the gene expression program activated by the hormone in these cells shows 8 main patterns of gene activation/inhibition. This newly identified estrogen-responsive transcriptome represents more than a simple cell cycle response, as only a few affected genes belong to the transcriptional program of the cell division cycle of eukaryotes, or showed a similar expression profile in other mitogen-stimulated human cells. Indeed, based on the functions assigned to the products of the genes they control, estrogen appears to affect several key features of BC cells, including their metabolic status, proliferation, survival, differentiation and resistance to stress and chemotherapy, as well as RNA and protein synthesis, maturation and turn-over rates. Interestingly, the estrogen-responsive transcriptome does not appear randomly interspersed in the genome. In chromosome 17, for example, a site particularly rich in genes activated by the hormone, physical association of co-regulated genes in clusters is evident in several instances, suggesting the likely existence of estrogen-responsive domains in the human genome.

scholarly journals Arabidopsis 14-3-3 epsilon members contribute to polarity of PIN auxin carrier and auxin transport-related development

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Jutta Keicher ◽  
Nina Jaspert ◽  
Katrin Weckermann ◽  
Claudia Möller ◽  
Christian Throm ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Membrane Trafficking ◽  
Auxin Transport ◽  
Distribution Patterns ◽  
Protein Protein Interactions ◽  
Cellular Functions ◽  
Dependent Protein ◽  
Group Members ◽  
Auxin Efflux Carriers

Eukaryotic 14-3-3 proteins have been implicated in the regulation of diverse biological processes by phosphorylation-dependent protein-protein interactions. The Arabidopsis genome encodes two groups of 14-3-3s, one of which – epsilon – is thought to fulfill conserved cellular functions. Here, we assessed the in vivo role of the ancestral 14-3-3 epsilon group members. Their simultaneous and conditional repression by RNA interference and artificial microRNA in seedlings led to altered distribution patterns of the phytohormone auxin and associated auxin transport-related phenotypes, such as agravitropic growth. Moreover, 14-3-3 epsilon members were required for pronounced polar distribution of PIN-FORMED auxin efflux carriers within the plasma membrane. Defects in defined post-Golgi trafficking processes proved causal for this phenotype and might be due to lack of direct 14-3-3 interactions with factors crucial for membrane trafficking. Taken together, our data demonstrate a fundamental role for the ancient 14-3-3 epsilon group members in regulating PIN polarity and plant development.

scholarly journals A transcriptome atlas of the mouse iris at single cell resolution defines cell types and the genomic response to pupil dilation

2021 ◽  
Author(s):  
Jie Wang ◽  
Amir Rattner ◽  
Jeremy Nathans
Keyword(s):  
Stromal Cells ◽  
Pupil Diameter ◽  
Cell Types ◽  
Potential Source ◽  
Hybridization Probes ◽  
Single Nucleus ◽  
Cell Type Specific ◽  
A Site ◽  
Genomic Response

AbstractThe iris controls the level of retinal illumination by controlling pupil diameter. It is a site of diverse ophthalmological diseases and it is a potential source of cells for ocular auto-transplantation. The present study provides foundational data on the mouse iris based on single nucleus RNA sequencing. More specifically, this work has (1) defined all of the major cell types in the mouse iris and ciliary body, (2) led to the discovery of two types of iris stromal cells and two types of iris sphincter cells, (3) revealed the differences in cell type-specific transcriptomes in the resting, constricted, and dilated states, and (4) identified and validated antibody and in situ hybridization probes that can be used to visualize the major iris cell types. By immunostaining for specific iris cell-types, we have observed and quantified distortions in nuclear morphology associated with iris dilation and clarified the neural crest contribution to the iris by showing that Wnt1-Cre-expressing progenitors contribute to nearly all iris cell types, whereas Sox10-Cre-expressing progenitors contribute only to stromal cells. This work should be useful as a point of reference for investigations of iris development, disease, and pharmacology, for the isolation and propagation of defined iris cell types, and for iris cell engineering and transplantation.

scholarly journals A transcriptome atlas of the mouse iris at single-cell resolution defines cell types and the genomic response to pupil dilation

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jie Wang ◽  
Amir Rattner ◽  
Jeremy Nathans
Keyword(s):  
Stromal Cells ◽  
Pupil Diameter ◽  
Cell Types ◽  
Potential Source ◽  
Hybridization Probes ◽  
Single Nucleus ◽  
Cell Type Specific ◽  
A Site ◽  
Genomic Response

The iris controls the level of retinal illumination by controlling pupil diameter. It is a site of diverse ophthalmologic diseases and it is a potential source of cells for ocular auto-transplantation. The present study provides foundational data on the mouse iris based on single nucleus RNA sequencing. More specifically, this work has (1) defined all of the major cell types in the mouse iris and ciliary body, (2) led to the discovery of two types of iris stromal cells and two types of iris sphincter cells, (3) revealed the differences in cell type-specific transcriptomes in the resting vs. dilated states, and (4) identified and validated antibody and in situ hybridization probes that can be used to visualize the major iris cell types. By immunostaining for specific iris cell types, we have observed and quantified distortions in nuclear morphology associated with iris dilation and clarified the neural crest contribution to the iris by showing that Wnt1-Cre-expressing progenitors contribute to nearly all iris cell types, whereas Sox10-Cre-expressing progenitors contribute only to stromal cells. This work should be useful as a point of reference for investigations of iris development, disease, and pharmacology, for the isolation and propagation of defined iris cell types, and for iris cell engineering and transplantation.

Nutritional Aspects of Spermidine

2020 ◽  
Vol 40 (1) ◽  
pp. 135-159 ◽  
Author(s):  
Frank Madeo ◽  
Sebastian J. Hofer ◽  
Tobias Pendl ◽  
Maria A. Bauer ◽  
Tobias Eisenberg ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Epidemiological Studies ◽  
Preclinical Models ◽  
Cellular Functions ◽  
Age Related ◽  
Specific Manner ◽  
Age Dependent ◽  
Cell Type Specific ◽  
Positively Charged ◽  
Overall Mortality

Natural polyamines (spermidine and spermine) are small, positively charged molecules that are ubiquitously found within organisms and cells. They exert numerous (intra)cellular functions and have been implicated to protect against several age-related diseases. Although polyamine levels decline in a complex age-dependent, tissue-, and cell type–specific manner, they are maintained in healthy nonagenarians and centenarians. Increased polyamine levels, including through enhanced dietary intake, have been consistently linked to improved health and reduced overall mortality. In preclinical models, dietary supplementation with spermidine prolongs life span and health span. In this review, we highlight salient aspects of nutritional polyamine intake and summarize the current knowledge of organismal and cellular uptake and distribution of dietary (and gastrointestinal) polyamines and their impact on human health. We further summarize clinical and epidemiological studies of dietary polyamines.

scholarly journals Biological Functions of HMGN Chromosomal Proteins

2020 ◽  
Vol 21 (2) ◽  
pp. 449
Author(s):  
Ravikanth Nanduri ◽  
Takashi Furusawa ◽  
Michael Bustin
Keyword(s):  
Biological Function ◽  
High Mobility ◽  
Cell Types ◽  
Vertebrate Development ◽  
Cellular Functions ◽  
Cell Identity ◽  
Multiple Cell ◽  
Cell Type Specific ◽  
Nucleosome Binding ◽  
Regulatory Sites

Chromatin plays a key role in regulating gene expression programs necessary for the orderly progress of development and for preventing changes in cell identity that can lead to disease. The high mobility group N (HMGN) is a family of nucleosome binding proteins that preferentially binds to chromatin regulatory sites including enhancers and promoters. HMGN proteins are ubiquitously expressed in all vertebrate cells potentially affecting chromatin function and epigenetic regulation in multiple cell types. Here, we review studies aimed at elucidating the biological function of HMGN proteins, focusing on their possible role in vertebrate development and the etiology of disease. The data indicate that changes in HMGN levels lead to cell type-specific phenotypes, suggesting that HMGN optimize epigenetic processes necessary for maintaining cell identity and for proper execution of specific cellular functions. This manuscript contains tables that can be used as a comprehensive resource for all the English written manuscripts describing research aimed at elucidating the biological function of the HMGN protein family.

scholarly journals CRISPR-Mediated Knockout of Long 3′ UTR mRNA Isoforms in mESC-Derived Neurons

2021 ◽  
Vol 12 ◽  
Author(s):  
Bongmin Bae ◽  
Pedro Miura
Keyword(s):  
Genetic Manipulation ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cell ◽  
Cellular Functions ◽  
Mrna Isoforms ◽  
Mouse Cortex ◽  
Long Read ◽  
Sequencing Strategy ◽  
Cost Efficient ◽  
A Site

Alternative cleavage and polyadenylation (APA) is pervasive, occurring for more than 70% of human and mouse genes. Distal poly(A) site selection to generate longer 3′ UTR mRNA isoforms is prevalent in the nervous system, affecting thousands of genes. Here, we establish mouse embryonic stem cell (mESC)-derived neurons (mES-neurons) as a suitable system to study long 3′ UTR isoforms. RNA-seq analysis revealed that mES-neurons show widespread 3′ UTR lengthening that closely resembles APA patterns found in mouse cortex. mESCs are highly amenable to genetic manipulation. We present a method to eliminate long 3′ UTR isoform expression using CRISPR/Cas9 editing. This approach can lead to clones with the desired deletion within several weeks. We demonstrate this strategy on the Mprip gene as a proof-of-principle. To confirm loss of long 3′ UTR expression and the absence of cryptic poly(A) site usage stemming from the CRISPR deletion, we present a simple and cost-efficient targeted long-read RNA-sequencing strategy using the Oxford Nanopore Technologies platform. Using this method, we confirmed specific loss of the Mprip long 3′ UTR isoform. CRISPR gene editing of mESCs thus serves as a highly relevant platform for studying the molecular and cellular functions of long 3′ UTR mRNA isoforms.

scholarly journals Actin isovariant ACT7 regulates root meristem development in Arabidopsis through modulating auxin and ethylene responses

2021 ◽  
Author(s):  
Takahiro Numata ◽  
Kenji Sugita ◽  
Arifa Ahamed Rahman ◽  
Abidur Rahman
Keyword(s):  
Cell Division ◽  
Cell Elongation ◽  
Root Meristem ◽  
Primary Role ◽  
Arabidopsis Root ◽  
Meristem Development ◽  
Constant Cell ◽  
Division Cell ◽  
Auxin Efflux Carriers

Meristem, which sustains a reservoir of niche cells at its apex, is the most functionally dynamic part in a plant body. The shaping of the meristem requires constant cell division and cell elongation, that are regulated by hormones and cell cytoskeletal components, actin. Although the roles of hormones in regulating meristem development have been extensively studied, the role of actin in this process is still elusive. Using the single and double mutants of the vegetative class actin, we demonstrate that ACT7 plays a primary role in regulating the root meristem development. In absence of ACT7, but not ACT8 and ACT2, cellular depolymerization of actin is observed. Consistently, act7 mutant shows reduced cell division, cell elongation and meristem length. Intracellular distribution and trafficking of auxin transport proteins in the actin mutants revealed that ACT7 specifically functions in root meristem to facilitate the trafficking of auxin efflux carriers PIN1 and PIN2, and consequently the transport of auxin. Compared with act7, act7act8 double mutant shows slightly enhanced phenotypic response and altered intracellular trafficking. The altered distribution of auxin in act7 and act7act8 affects the roots response to ethylene but not to cytokinin. Collectively, our results suggest that Arabidopsis root meristem development is primarily controlled through actin isovariant ACT7 mediated modulation of auxin-ethylene response.

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