scholarly journals Chronic Stress Alters Astrocyte Morphology in Mouse Prefrontal Cortex

2021 ◽  
Author(s):  
Sierra A Codeluppi ◽  
Dipashree Chatterjee ◽  
Thomas D Prevot ◽  
Yashika Bansal ◽  
Keith A Misquitta ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Chronic Stress ◽  
Fluorescent Protein ◽  
Behavioral Changes ◽  
Glial Fibrillary Acid Protein ◽  
Behavioral Deficits ◽  
Acid Protein ◽  
Potential Link ◽  
Green Fluorescent ◽  
Stress Models

Abstract Background Neuromorphological changes are consistently reported in the prefrontal cortex (PFC) of patients with stress-related disorders and in rodent stress models, but the effects of stress on astrocyte morphology and potential link to behavioral deficits are relatively unknown. Methods To answer these questions, transgenic mice expressing green fluorescent protein (GFP) under the glial fibrillary acid protein (GFAP) promotor were subjected to 7, 21 or 35 days of chronic restraint stress (CRS). CRS induced behavioral effects on anhedonia- and anxiety-like behaviors were measured using the sucrose intake and the PhenoTyper tests, respectively. PFC GFP+ or GFAP+ cells morphology was assessed using Sholl analysis and associations with behavior were determined using correlation analysis. Results CRS-exposed male and female mice displayed anxiety-like behavior at 7, 21 and 35 days and anhedonia-like behavior at 35 days. Analysis of GFAP+ cell morphology revealed significant atrophy of distal processes following 21 and 35 days of CRS. CRS induced similar decreases in intersections at distal radii for GFP+ cells, accompanied by increased proximal processes. In males, the number of intersections at the most distal radius step significantly correlated with anhedonia-like behavior (r=0.622, p<0.05) for GFP+ cells and with behavioral emotionality calculated by z-scoring all behavioral measured deficits (r=-0.667, p<0.05). Similar but not significant correlations were observed in females. No correlation between GFP+ cell atrophy with anxiety-like behavior was found. Conclusion Chronic stress exposure induces a progressive atrophy of cortical astroglial cells, potentially contributing to maladaptive neuroplastic and behavioral changes associated with stress-related disorders.

scholarly journals Chronic Stress Alters Astrocyte Morphology in Mouse Prefrontal Cortex

2021 ◽  
Author(s):  
Sierra A. Codeluppi ◽  
Dipashree Chatterjee ◽  
Thomas D. Prevot ◽  
Keith A. Misquitta ◽  
Etienne Sibille ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Chronic Stress ◽  
Fluorescent Protein ◽  
Glial Fibrillary Acid Protein ◽  
Behavioral Deficits ◽  
Sholl Analysis ◽  
Acid Protein ◽  
Potential Link ◽  
Green Fluorescent ◽  
Stress Models

AbstractBackgroundNeuromorphological changes are consistently reported in the prefrontal cortex (PFC) of patients with stress-related disorders and in rodent stress models, but the effects of stress on astrocyte morphology and potential link to behavioral deficits are relatively unknown.MethodsTo answer these questions, transgenic mice expressing green fluorescent protein (GFP) under the glial fibrillary acid protein (GFAP) promotor were subjected to 7, 21 or 35 days of chronic restraint stress (CRS). CRS behavioral effects on anhedonia- and anxiety-like behaviours were measured using the sucrose intake and the PhenoTyper tests, respectively. PFC GFP+ or GFAP+ cells morphology was assessed using Sholl analysis and associations with behavior were determined using correlation analysis.ResultsCRS-exposed mice displayed anxiety-like behavior at 7, 21 and 35 days and anhedonia-like behavior at 35 days. Analysis of GFAP+ cell morphology revealed significant atrophy of distal processes following 21 and 35 days of CRS. CRS induced similar decreases in intersections at distal radii for GFP+ cells, accompanied by increased proximal processes. Additionally, the number of intersections at the most distal radius step significantly correlated with time spent in the shelter zone in the PhenoTyper test (r=-0.581, p<0.01) for GFP+ cells and with behavioural emotionality calculated by z-scoring all behavioral measured deficits, for both GFAP+ and GFP+ cells (r=-0.400, p<0.05; r=-0.399, p<0.05).ConclusionChronic stress exposure induces a progressive atrophy of cortical astroglial cells, potentially contributing to maladaptive neuroplastic changes associated with stress-related disorders.

scholarly journals Nestin-Expressing Cells Divide and Adopt a Complex Electrophysiologic Phenotype after Transient Brain Ischemia

2005 ◽  
Vol 25 (12) ◽  
pp. 1613-1624 ◽  
Author(s):  
Golo Kronenberg ◽  
Li-Ping Wang ◽  
Michael Synowitz ◽  
Karen Gertz ◽  
Juri Katchanov ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Brain Slices ◽  
Membrane Properties ◽  
Glial Fibrillary Acid Protein ◽  
Nestin Expression ◽  
Ischemic Lesion ◽  
Whole Cell Patch Clamp ◽  
Large Numbers ◽  
Acid Protein ◽  
Green Fluorescent

The intermediate filament nestin is upregulated in response to cerebral ischemia; the significance of this, however, is incompletely understood. Here, we used transgenic mice that express green fluorescent protein (GFP) under control of the nestin promotor to characterize the fate of nestin-expressing cells up to 8 weeks after 30 mins occlusion of the middle cerebral artery (MCAo) and reperfusion. The population of nestin-GFP + cells increased in the ischemic lesion rim and core within 4 days, did not become TUNEL-positive, and was detectable up to 8 weeks in the lesion scar. Nestin-GFP + cells proliferated in situ and underwent approximately one round of cell division. They were not recruited in large numbers from the subventricular zone (SVZ) as indicated by absence of colabeling with intracerebroventricularly injected dye DiI in the majority of nestin-GFP + cells. Nestin-GFP + cells expressed the chondroitin sulfate proteoglycan NG2 and nestin protein, but typically lacked mature astrocytic markers, that is, glial fibrillary acid protein (GFAP) or S100 β. Vice versa, the majority of GFAP + cells lacked nestin-expression and surrounded the ischemic lesion by 4 days. Whole-cell patch-clamp recordings in acute brain slices from controls showed that only about half of nestin-GFP + cells displayed complex membrane properties. In contrast, 4 days after the insult all nestin-GFP + cells expressed these properties. We hypothesize that the change in physiologic properties induced by the ischemic insult is directed toward a specific function of nestin-expressing cells.

scholarly journals Saccharomyces cerevisiae Nip7p is required for efficient 60S ribosome subunit biogenesis.

1997 ◽  
Vol 17 (9) ◽  
pp. 5001-5015 ◽  
Author(s):  
N I Zanchin ◽  
P Roberts ◽  
A DeSilva ◽  
F Sherman ◽  
D S Goldfarb
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fluorescent Protein ◽  
Open Reading Frames ◽  
Growth Defect ◽  
Temperature Sensitive ◽  
Protein Fusion ◽  
Acid Protein ◽  
Conserved Gene ◽  
Green Fluorescent

The Saccharomyces cerevisiae temperature-sensitive (ts) allele nip7-1 exhibits phenotypes associated with defects in the translation apparatus, including hypersensitivity to paromomycin and accumulation of halfmer polysomes. The cloned NIP7+ gene complemented the nip7-1 ts growth defect, the paromomycin hypersensitivity, and the halfmer defect. NIP7 encodes a 181-amino-acid protein (21 kDa) with homology to predicted products of open reading frames from humans, Caenorhabditis elegans, and Arabidopsis thaliana, indicating that Nip7p function is evolutionarily conserved. Gene disruption analysis demonstrated that NIP7 is essential for growth. A fraction of Nip7p cosedimented through sucrose gradients with free 60S ribosomal subunits but not with 80S monosomes or polysomal ribosomes, indicating that it is not a ribosomal protein. Nip7p was found evenly distributed throughout the cytoplasm and nucleus by indirect immunofluorescence; however, in vivo localization of a Nip7p-green fluorescent protein fusion protein revealed that a significant amount of Nip7p is present inside the nucleus, most probably in the nucleolus. Depletion of Nip7-1p resulted in a decrease in protein synthesis rates, accumulation of halfmers, reduced levels of 60S subunits, and, ultimately, cessation of growth. Nip7-1p-depleted cells showed defective pre-rRNA processing, including accumulation of the 35S rRNA precursor, presence of a 23S aberrant precursor, decreased 20S pre-rRNA levels, and accumulation of 27S pre-rRNA. Delayed processing of 27S pre-rRNA appeared to be the cause of reduced synthesis of 25S rRNA relative to 18S rRNA, which may be responsible for the deficit of 60S subunits in these cells.

scholarly journals Purification, Characterization, and Gene Analysis of a Chitosanase (ChoA) from Matsuebacter chitosanotabidus3001

1999 ◽  
Vol 181 (21) ◽  
pp. 6642-6649 ◽  
Author(s):  
Jae Kweon Park ◽  
Kumiko Shimono ◽  
Nobuhisa Ochiai ◽  
Kazutaka Shigeru ◽  
Masako Kurita ◽  
...  
Keyword(s):  
Amino Acid ◽  
Fluorescent Protein ◽  
Genomic Library ◽  
Amino Acid Sequences ◽  
Glycol Chitosan ◽  
Gene Encoding ◽  
Reading Frame ◽  
Acid Protein ◽  
Green Fluorescent ◽  
Potential Inhibitors

ABSTRACT The extracellular chitosanase (34,000 M r) produced by a novel gram-negative bacterium Matsuebacter chitosanotabidus 3001 was purified. The optimal pH of this chitosanase was 4.0, and the optimal temperature was between 30 and 40°C. The purified chitosanase was most active on 90% deacetylated colloidal chitosan and glycol chitosan, both of which were hydrolyzed in an endosplitting manner, but this did not hydrolyze chitin, cellulose, or their derivatives. Among potential inhibitors, the purified chitosanase was only inhibited by Ag+. Internal amino acid sequences of the purified chitosanase were obtained. A PCR fragment corresponding to one of these amino acid sequences was then used to screen a genomic library for the entire choA gene encoding chitosanase. Sequencing of the choA gene revealed an open reading frame encoding a 391-amino-acid protein. The N-terminal amino acid sequence had an excretion signal, but the sequence did not show any significant homology to other proteins, including known chitosanases. The 80-amino-acid excretion signal of ChoA fused to green fluorescent protein was functional in Escherichia coli. Taken together, these results suggest that we have identified a novel, previously unreported chitosanase.

scholarly journals Dendritic Spines in Depression: What We Learned from Animal Models

2016 ◽  
Vol 2016 ◽  
pp. 1-26 ◽  
Author(s):  
Hui Qiao ◽  
Ming-Xing Li ◽  
Chang Xu ◽  
Hui-Bin Chen ◽  
Shu-Cheng An ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Nucleus Accumbens ◽  
Chronic Stress ◽  
Dendritic Spines ◽  
Mild Stress ◽  
Spine Density ◽  
Chronic Social Defeat Stress ◽  
Underlying Mechanisms ◽  
Dendritic Atrophy ◽  
Stress Models

Depression, a severe psychiatric disorder, has been studied for decades, but the underlying mechanisms still remain largely unknown. Depression is closely associated with alterations in dendritic spine morphology and spine density. Therefore, understanding dendritic spines is vital for uncovering the mechanisms underlying depression. Several chronic stress models, including chronic restraint stress (CRS), chronic unpredictable mild stress (CUMS), and chronic social defeat stress (CSDS), have been used to recapitulate depression-like behaviors in rodents and study the underlying mechanisms. In comparison with CRS, CUMS overcomes the stress habituation and has been widely used to model depression-like behaviors. CSDS is one of the most frequently used models for depression, but it is limited to the study of male mice. Generally, chronic stress causes dendritic atrophy and spine loss in the neurons of the hippocampus and prefrontal cortex. Meanwhile, neurons of the amygdala and nucleus accumbens exhibit an increase in spine density. These alterations induced by chronic stress are often accompanied by depression-like behaviors. However, the underlying mechanisms are poorly understood. This review summarizes our current understanding of the chronic stress-induced remodeling of dendritic spines in the hippocampus, prefrontal cortex, orbitofrontal cortex, amygdala, and nucleus accumbens and also discusses the putative underlying mechanisms.

scholarly journals Identification and functional characterization of a novel human and rat riboflavin transporter, RFT1

2008 ◽  
Vol 295 (3) ◽  
pp. C632-C641 ◽  
Author(s):  
Atsushi Yonezawa ◽  
Satohiro Masuda ◽  
Toshiya Katsura ◽  
Ken-ichi Inui
Keyword(s):  
Amino Acid ◽  
Fluorescent Protein ◽  
Rat Kidney ◽  
Functional Characterization ◽  
Hek 293 ◽  
Reading Frame ◽  
Transporter Family ◽  
Acid Protein ◽  
Green Fluorescent ◽  
Interfering Rna

Absorption of riboflavin is mediated by transporter(s). However, a mammalian riboflavin transporter has yet to be identified. In the present study, the novel human and rat riboflavin transporters hRFT1 and rRFT1 were identified on the basis of our rat kidney mRNA expression database (Horiba N, Masuda S, Takeuchi A, Saito H, Okuda M, Inui K. Kidney Int 66: 29–45, 2004). hRFT1 and rRFT1 cDNAs have an open reading frame encoding 448- and 450-amino acid proteins, respectively, that exhibit 81.1% identity and 96.4% similarity to one another. In addition, an inactive splice variant of hRFT1, hRFT1sv, was also cloned. The hRFT1sv cDNA, which encodes a 167-amino acid protein, retains an intron between exons 2 and 3 of hRFT1. Real-time PCR revealed that the sum of hRFT1 and hRFT1sv mRNAs was expressed strongly in the placenta and small intestine and was detected in all tissues examined. In addition, hRFT1 and hRFT1sv were expressed in human embryonic kidney (HEK)-293 and Caco-2 cells. HEK-293 cells transfected with green fluorescent protein-tagged hRFT1 and rRFT1 exhibited a fluorescent signal in the plasma membrane. Overexpression of hRFT1 and rRFT1, but not hRFT1sv, increased the cellular accumulation of [3H]riboflavin. The transfection of small interfering RNA targeting both hRFT1 and hRFT1sv significantly decreased the uptake of [3H]riboflavin by HEK-293 and Caco-2 cells. Riboflavin transport is Na+, potential, and pH independent. Kinetic analyses demonstrated that the Michaelis-Menten constants for the uptake by HEK-293 and Caco-2 cells were 28.1 and 63.7 nM, respectively. We propose that hRFT1 and rRFT1 are novel mammalian riboflavin transporters, which belong to a new mammalian riboflavin transporter family.

scholarly journals Function of a STIM1 Homologue in C. elegans: Evidence that Store-operated Ca2+ Entry Is Not Essential for Oscillatory Ca2+ Signaling and ER Ca2+ Homeostasis

2006 ◽  
Vol 128 (4) ◽  
pp. 443-459 ◽  
Author(s):  
Xiaohui Yan ◽  
Juan Xing ◽  
Catherine Lorin-Nebel ◽  
Ana Y. Estevez ◽  
Keith Nehrke ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Fluorescent Protein ◽  
Contractile Activity ◽  
C Elegans ◽  
Unfolded Protein ◽  
Acid Protein ◽  
Ef Hand ◽  
Green Fluorescent ◽  
Oscillations And Waves ◽  
Soc Channels

1,4,5-trisphosphate (IP3)-dependent Ca2+ signaling regulates gonad function, fertility, and rhythmic posterior body wall muscle contraction (pBoc) required for defecation in Caenorhabditis elegans. Store-operated Ca2+ entry (SOCE) is activated during endoplasmic reticulum (ER) Ca2+ store depletion and is believed to be an essential and ubiquitous component of Ca2+ signaling pathways. SOCE is thought to function to refill Ca2+ stores and modulate Ca2+ signals. Recently, stromal interaction molecule 1 (STIM1) was identified as a putative ER Ca2+ sensor that regulates SOCE. We cloned a full-length C. elegans stim-1 cDNA that encodes a 530–amino acid protein with ∼21% sequence identity to human STIM1. Green fluorescent protein (GFP)–tagged STIM-1 is expressed in the intestine, gonad sheath cells, and spermatheca. Knockdown of stim-1 expression by RNA interference (RNAi) causes sterility due to loss of sheath cell and spermatheca contractile activity required for ovulation. Transgenic worms expressing a STIM-1 EF-hand mutant that constitutively activates SOCE in Drosophila and mammalian cells are sterile and exhibit severe pBoc arrhythmia. stim-1 RNAi dramatically reduces STIM-1∷GFP expression, suppresses the EF-hand mutation–induced pBoc arrhythmia, and inhibits intestinal store-operated Ca2+ (SOC) channels. However, stim-1 RNAi surprisingly has no effect on pBoc rhythm, which is controlled by intestinal oscillatory Ca2+ signaling, in wild type and IP3 signaling mutant worms, and has no effect on intestinal Ca2+ oscillations and waves. Depletion of intestinal Ca2+ stores by RNAi knockdown of the ER Ca2+ pump triggers the ER unfolded protein response (UPR). In contrast, stim-1 RNAi fails to induce the UPR. Our studies provide the first detailed characterization of STIM-1 function in an intact animal and suggest that SOCE is not essential for certain oscillatory Ca2+ signaling processes and for maintenance of store Ca2+ levels in C. elegans. These findings raise interesting and important questions regarding the function of SOCE and SOC channels under normal and pathophysiological conditions.

scholarly journals Cloning and Characterization of an Ovine Intracellular Seven Transmembrane Receptor for Progesterone that Mediates Calcium Mobilization

Endocrinology ◽  
2006 ◽  
Vol 147 (9) ◽  
pp. 4151-4159 ◽  
Author(s):  
R. L. Ashley ◽  
C. M. Clay ◽  
T. A. Farmerie ◽  
G. D. Niswender ◽  
T. M. Nett
Keyword(s):  
Endoplasmic Reticulum ◽  
Cho Cells ◽  
Cellular Localization ◽  
Fluorescent Protein ◽  
Specific Binding ◽  
Protein Fusion ◽  
Acid Protein ◽  
Modulation Of Gene Expression ◽  
Hydroxy Progesterone ◽  
Green Fluorescent

Classically, progesterone has been thought to act only through the well-known genomic pathway involving hormone binding to nuclear receptors (nPR) and subsequent modulation of gene expression. However, there is increasing evidence for rapid, nongenomic effects of progesterone in a variety of tissues in mammals, and it seems likely that a membrane PR (mPR) is causing these events. The objective of this study was to isolate and characterize an ovine mPR distinct from the nPR. A cDNA clone was isolated from ovine genomic DNA by PCR. The ovine mPR is a 350-amino acid protein that, based on computer hydrophobicity analysis, possesses seven transmembrane domains and is distinct from the nPR. Message for the ovine mPR was detected in hypothalamus, pituitary, uterus, ovary, and corpus luteum by RT-PCR. In CHO cells that overexpressed a mPR-green fluorescent protein fusion protein, the ovine mPR was localized to the endoplasmic reticulum and not the plasma membrane. Specific binding of 3H-progesterone to membrane fractions was demonstrated in CHO cells that expressed the ovine mPR but not in nontransfected cells. Furthermore, progesterone and 17α-hydroxy-progesterone stimulated intracellular Ca2+ mobilization in CHO cells that expressed ovine mPR in Ca2+-free medium (P &lt; 0.05) but not in CHO cells transfected with empty vector. This rise in intracellular Ca2+ is believed to be from the endoplasmic reticulum as intracellular Ca2+ mobilization is absent when mPR transfected cells are first treated with thapsigargin to deplete Ca2+ stores from the endoplasmic reticulum. Isolation, identification, tissue distribution, cellular localization, steroid binding, and a functional response for a unique intracellular mPR in the sheep are presented.

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