scholarly journals Enhanced Expression of NR2B Subunits of NMDA Receptors in the Inherited Glaucomatous DBA/2J Mouse Retina

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Ling-Dan Dong ◽  
Jie Chen ◽  
Fang Li ◽  
Feng Gao ◽  
Jihong Wu ◽  
...  

DBA/2J mouse has been used as a model for spontaneous secondary glaucoma. Here, we investigated changes in expression of NMDA receptor (NMDAR) subunits and Cdk5/p35/NMDAR signaling in retinas of DBA/2J mice using Western blot technique. The protein levels of NR1 and NR2A subunits in retinas of DBA/2J mice at all ages (6–12 months) were not different from those in age-matched C57BL/6 mice. In contrast, the protein levels of NR2B subunits, in addition to age-dependent change, significantly increased with elevated intraocular pressure (IOP) in DBA/2J mice at 6 and 9 months as compared with age-matched controls. Moreover, expression of Cdk5, p35 and ratio of p-NR2AS1232/NR2A progressively increased with time in both strains, suggestive of activated Cdk5/p35 signaling pathway. However, the changes in these proteins were in the same levels in both strain mice, except a significant increase of p35 proteins at 6 months in DBA/2J mice. Meanwhile, the protein levels of Brn-3a, a retinal ganglion cell (RGC) maker, remarkably decreased at 9–12 months in DBA/2J mice, which was in parallel with the changes of NR2B expression. Our results suggest that elevated IOP-induced increase in expression of NR2B subunits of NMDARs may be involved in RGC degeneration of DBA/2J mice.

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Yeon Ho Yoo ◽  
Dae Won Kim ◽  
Bai Hui Chen ◽  
Hyejin Sim ◽  
Bora Kim ◽  
...  

Abstract Background Aging is one of major causes triggering neurophysiological changes in many brain substructures, including the hippocampus, which has a major role in learning and memory. Thioredoxin (Trx) is a class of small redox proteins. Among the Trx family, Trx2 plays an important role in the regulation of mitochondrial membrane potential and is controlled by TrxR2. Hitherto, age-dependent alterations in Trx2 and TrxR2 in aged hippocampi have been poorly investigated. Therefore, the aim of this study was to examine changes in Trx2 and TrxR2 in mouse and rat hippocampi by age and to compare their differences between mice and rats. Results Trx2 and TrxR2 levels using Western blots in mice were the highest at young age and gradually reduced with time, showing that no significant differences in the levels were found between the two subfields. In rats, however, their expression levels were the lowest at young age and gradually increased with time. Nevertheless, there were no differences in cellular distribution and morphology in their hippocampi when it was observed by cresyl violet staining. In addition, both Trx2 and TrxR2 immunoreactivities in the CA1-3 fields were mainly shown in pyramidal cells (principal cells), showing that their immunoreactivities were altered like changes in their protein levels. Conclusions Our current findings suggest that Trx2 and TrxR2 expressions in the brain may be different according to brain regions, age and species. Therefore, further studies are needed to examine the reasons of the differences of Trx2 and TrxR2 expressions in the hippocampus between mice and rats.


2008 ◽  
Vol 28 (18) ◽  
pp. 5634-5645 ◽  
Author(s):  
Francesco Oriente ◽  
Luis Cesar Fernandez Diaz ◽  
Claudia Miele ◽  
Salvatore Iovino ◽  
Silvia Mori ◽  
...  

ABSTRACT We have examined glucose homeostasis in mice hypomorphic for the homeotic transcription factor gene Prep1. Prep1-hypomorphic (Prep1 i / i ) mice exhibit an absolute reduction in circulating insulin levels but normal glucose tolerance. In addition, these mice exhibit protection from streptozotocin-induced diabetes and enhanced insulin sensitivity with improved glucose uptake and insulin-dependent glucose disposal by skeletal muscle. This muscle phenotype does not depend on reduced expression of the known Prep1 transcription partner, Pbx1. Instead, in Prep1 i / i muscle, we find normal Pbx1 but reduced levels of the recently identified novel Prep1 interactor p160. Consistent with this reduction, we find a muscle-selective increase in mRNA and protein levels of PGC-1α, accompanied by enhanced expression of the GLUT4 transporter, responsible for insulin-stimulated glucose uptake in muscle. Indeed, using L6 skeletal muscle cells, we induced the opposite effects by overexpressing Prep1 or p160, but not Pbx1. In vivo skeletal muscle delivery of p160 cDNA in Prep1 i / i mice also reverses the molecular phenotype. Finally, we show that Prep1 controls the stability of the p160 protein. We conclude that Prep1 controls insulin sensitivity through the p160-GLUT4 pathway.


Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3319
Author(s):  
Verena Warnsmann ◽  
Jana Meisterknecht ◽  
Ilka Wittig ◽  
Heinz D. Osiewacz

The accumulation of functionally impaired mitochondria is a key event in aging. Previous works with the fungal aging model Podospora anserina demonstrated pronounced age-dependent changes of mitochondrial morphology and ultrastructure, as well as alterations of transcript and protein levels, including individual proteins of the oxidative phosphorylation (OXPHOS). The identified protein changes do not reflect the level of the whole protein complexes as they function in-vivo. In the present study, we investigated in detail the age-dependent changes of assembled mitochondrial protein complexes, using complexome profiling. We observed pronounced age-depen-dent alterations of the OXPHOS complexes, including the loss of mitochondrial respiratory supercomplexes (mtRSCs) and a reduction in the abundance of complex I and complex IV. Additionally, we identified a switch from the standard complex IV-dependent respiration to an alternative respiration during the aging of the P. anserina wild type. Interestingly, we identified proteasome components, as well as endoplasmic reticulum (ER) proteins, for which the recruitment to mitochondria appeared to be increased in the mitochondria of older cultures. Overall, our data demonstrate pronounced age-dependent alterations of the protein complexes involved in energy transduction and suggest the induction of different non-mitochondrial salvage pathways, to counteract the age-dependent mitochondrial impairments which occur during aging.


2002 ◽  
Vol 50 (11) ◽  
pp. 1525-1536 ◽  
Author(s):  
Melissa Verburg ◽  
Ingrid B. Renes ◽  
Danielle J.P.M. Van Nispen ◽  
Sacha Ferdinandusse ◽  
Marieke Jorritsma ◽  
...  

The rapidly dividing small intestinal epithelium is very sensitive to the cytostatic drug methotrexate. We investigated the regulation of epithelial gene expression in rat jejunum during methotrexate-induced damage and regeneration. Ten differentiation markers were localized on tissue sections and quantified at mRNA and protein levels relative to control levels. We analyzed correlations in temporal expression patterns between markers. mRNA expression of enterocyte and goblet cell markers decreased significantly during damage for a specific period. Of these, sucrase-isomaltase (-62%) and CPS (-82%) were correlated. Correlations were also found between lactase (−76%) and SGLT1 (−77%) and between I-FABP (−52%) and L-FABP (-45%). Decreases in GLUT5 (−53%), MUC2 (-43%), and TFF3 (−54%) mRNAs occurred independently of any of the other markers. In contrast, lysozyme mRNA present in Paneth cells increased (+76%). At the protein level, qualitative and quantitative changes were in agreement with mRNA expression, except for Muc2 (+115%) and TFF3 (+81%), which increased significantly during damage, following independent patterns. During regeneration, expression of each marker returned to control levels. The enhanced expression of cytoprotective molecules (Muc2, TFF3, lysozyme) during damage represents maintenance of goblet cell and Paneth cell functions, most likely to protect the epithelium. Decreased expression of enterocyte-specific markers represents decreased enterocyte function, of which fatty acid transporters were least affected.


Development ◽  
1993 ◽  
Vol 118 (2) ◽  
pp. 539-552 ◽  
Author(s):  
H.S. Mudhar ◽  
R.A. Pollock ◽  
C. Wang ◽  
C.D. Stiles ◽  
W.D. Richardson

We have used in situ hybridization to visualize cells in the developing rat retina and optic nerve that express mRNAs encoding the A and B chains of platelet-derived growth factor (PDGF-A and PDGF-B), and the alpha and beta subunits of the PDGF receptor (PDGF-alpha R and PDGF-beta R). We have also visualized PDGF-A protein in these tissues by immunohistochemistry. In the retina, PDGF-A mRNA is present in pigment epithelial cells, ganglion neurons and a subset of amacrine neurons. PDGF-A transcripts accumulate in ganglion neurons during target innervation and in amacrine neurons around the time of eye opening, suggesting that PDGF-A expression in these cells may be regulated by target-derived signals or by electrical activity. In the mouse retina, PDGF-A immunoreactivity is present in the cell bodies, dendrites and proximal axons of ganglion neurons, and throughout the inner nuclear layer. PDGF-alpha R mRNA is expressed in the retina by astrocytes in the optic fibre layer and by a subset of cells in the inner nuclear layer that might be Muller glia or bipolar neurons. Taken together, our data suggest short-range paracrine interactions between PDGF-A and PDGF-alpha R, the ligand and its receptor being expressed in neighbouring layers of cells in the retina. In the optic nerve, PDGF-A immunoreactivity is present in astrocytes but apparently not in the retinal ganglion cell axons. PDGF-alpha R+ cells in the optic nerve first appear near the optic chiasm and subsequently spread to the retinal end of the nerve; these PDGF-alpha R+ cells are probably oligodendrocyte precursors (Pringle et al., 1992). RNA transcripts encoding PDGF-B and PDGF-beta R are expressed by cells of the hyaloid and mature vascular systems in the eye and optic nerve.


2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Tatjana Williams ◽  
Daniel Oppelt ◽  
Peter Nordbeck ◽  
Sabine Voll ◽  
Jost Schoenberger ◽  
...  

Rationale: We previously identified a mutation in the human transcriptional cofactor Eya4 as cause of familial dilated cardiomyopathy (DCM). We now provide evidence that the Eya4/Six1 signalling cascade also is crucial in acquired heart disease. Hypothesis: We hypothesize that the transcriptional complex Eya4/Six1 regulates targets relevant in normal cardiac function. We speculate it, amongst others, regulates expression of p27kip1, a known inhibitor of hypertrophy in adult cardiomyocytes, upon hypertrophic stimuli. Methods and results: We first examined the correlation of Eya4 and p27 in regards to phosphorylation and cellular distribution in failing and normal human hearts. Immunhistology revealed Eya4 is mainly distributed in the cytoplasm while p27 predominantly resides in the nucleus of healthy myocardial tissue. In sections of failing human hearts, Eya4 accumulated in the perinuclear and nuclear region; nuclear p27 levels were significantly diminished, phosphorylated p27 was evenly distributed in the cytoplasm. In a murine model of MI, IH showed Eya4 translocates in a time-dependent manner. WB analyses for p27 showed an age dependent decrease in p27 protein levels upon MI compared to control littermates. We generated transgenic mice with constitutive myocardial overexpression of Eya4 and E193. As judged by MRI, hemodynamic and morphometric analysis both transgenic mouse models developed cardiac phenotypes compared to age-matched wildtype littermates already under basal conditions in an age dependent manner. p27 expression and downstream factors were also altered in both transgenic lines as a result of Eya4, and accordingly, E193 overexpression. In summary, we provide evidence that the Eya4/Six1 signalling cascade is not only relevant in a rare version of heritable DCM but also in more common forms of acquired heart disease. Eya4/Six1 seems to regulate p27, which was shown to be an important regulator of cardiac physiology in postmitotic cardiomyocytes.


2013 ◽  
Vol 50 (4) ◽  
pp. 321-325 ◽  
Author(s):  
Eriko Nakasai ◽  
Hiroshi Tanizawa ◽  
Minani Takawaki ◽  
Kouichi Yanagita ◽  
Shin-ichi Kawakami ◽  
...  

2020 ◽  
Vol 46 (Supplement_1) ◽  
pp. S136-S136
Author(s):  
Camila Loureiro ◽  
Fachim Helene Aparecida ◽  
Corsi-Zuelli Fabiana ◽  
Shuhama Rosana ◽  
Joca Sâmia Regiane Lourenço ◽  
...  

Abstract Background Early-life stress is a key risk for psychiatric disorders that may produce changes in the neurodevelopment. N-methyl-d-aspartate receptor (NMDAR) have been associated with the pathophysiology of schizophrenia and evidence supports that epigenetic changes in NMDAR imply deficiencies in excitatory neurotransmission suggest its role in the neurobiology of psychoses (Uno and Coyle, 2019; Fachim et al., 2019; Gulchina et al., 2017). Aims: Although previous studies have shown abnormalities in the glutamatergic system in animal model of schizophrenia, it is not known if there are equivalent mRNA/protein alterations and DNA methylation changes in the brains of rats reared in isolation. Thus, in order to improve the knowledge of glutamatergic system role in psychosis, we investigated the NR1 and NR2 mRNA/protein and the DNA methylation levels of Grin1, Grin2a and Grin2b promoter region in the prefrontal cortex (PFC) and hippocampus (HIPPO) of male Wistar rats after isolation rearing. Furthermore, because the Parvalbumin (PV) deficit is the most consistent finding across animal models and schizophrenia itself, we also evaluated the expression of PV and other related GABAergic genes (REL and GAD1) in the brain of rats undergoing social isolation rearing as a validation of this animal model. We hypothesized that isolation rearing reduces mRNA and protein expressions of NMDAR subunits and cause DNA methylation changes. Methods Wistar rats were kept isolated or grouped (n=10/group) from weaning (21 days after birth) to 10 weeks and then exposed to the Open Field Test to assess locomotion. Afterwards the behavioural tests, the tissues were dissected for RNA/DNA extraction and NMDAR subunits were analysed using qRT-PCR, ELISA and pyrosequencing. Data were analysed by parametric tests. Results Isolated-reared animals presented: (i) decreased mRNA levels of Grin1 (p=0.011), Grin2a (p=0.039) and Grin2b (p=0.037) in the PFC followed by reduction in the GABAergic markers; (ii) increased NR1 protein levels in the HIPPO (p=0.001); (iii) hypermethylation of Grin1 at CpG5 in the PFC (p=0.047) and Grin2b CpG4 in the HIPPO when compared to grouped (p=0.024). Moreover, isolated and grouped animals presented a negative correlation between Grin1 mRNA and Grin1 methylation levels at CpG5 in the PFC (r: -0.577; p=0.010) and isolated rats presented a negative correlation between Grin2b methylation at CpG4 and NR2 protein levels in the HIPPO (r: -0.753; p=0.012). Discussion This study supports the hypothesis that the NMDAR methylation changes found in the brain tissues may underlie the NMDAR mRNA/protein expression alterations caused by the isolation period. These results highlighted the importance of the environmental influence during the development that may lead to cognitive impairments in adulthood. Moreover, we demonstrated that the social isolation rearing during 10 weeks causes long-lasting behavioral changes that may be more associated with late stages of schizophrenia. Our study contributes to the identification of the epigenetic mechanisms involved in the neuropathophysiology of schizophrenia, which can bring new pharmacotherapeutic strategies and to identify biomarkers that can improve the early interventions in schizophrenia patients. Finally, our data thus reinforce the validity of rats reared in social isolation after weaning in modelling aspects of schizophrenia, highlighting the glutamatergic and GABAergic features involved principally in the cognitive impairments related to prefrontal cortex.


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