Faculty Opinions recommendation of Extended exposure to a palatable cafeteria diet alters gene expression in brain regions implicated in reward, and withdrawal from this diet alters gene expression in brain regions associated with stress.

Author(s):  
Harriet de Wit
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiao Li ◽  
Jakob Seidlitz ◽  
John Suckling ◽  
Feiyang Fan ◽  
Gong-Jun Ji ◽  
...  

AbstractMajor depressive disorder (MDD) has been shown to be associated with structural abnormalities in a variety of spatially diverse brain regions. However, the correlation between brain structural changes in MDD and gene expression is unclear. Here, we examine the link between brain-wide gene expression and morphometric changes in individuals with MDD, using neuroimaging data from two independent cohorts and a publicly available transcriptomic dataset. Morphometric similarity network (MSN) analysis shows replicable cortical structural differences in individuals with MDD compared to control subjects. Using human brain gene expression data, we observe that the expression of MDD-associated genes spatially correlates with MSN differences. Analysis of cell type-specific signature genes suggests that microglia and neuronal specific transcriptional changes account for most of the observed correlation with MDD-specific MSN differences. Collectively, our findings link molecular and structural changes relevant for MDD.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Melanie Lindner ◽  
Irene Verhagen ◽  
Heidi M. Viitaniemi ◽  
Veronika N. Laine ◽  
Marcel E. Visser ◽  
...  

Abstract Background DNA methylation is likely a key mechanism regulating changes in gene transcription in traits that show temporal fluctuations in response to environmental conditions. To understand the transcriptional role of DNA methylation we need simultaneous within-individual assessment of methylation changes and gene expression changes over time. Within-individual repeated sampling of tissues, which are essential for trait expression is, however, unfeasible (e.g. specific brain regions, liver and ovary for reproductive timing). Here, we explore to what extend between-individual changes in DNA methylation in a tissue accessible for repeated sampling (red blood cells (RBCs)) reflect such patterns in a tissue unavailable for repeated sampling (liver) and how these DNA methylation patterns are associated with gene expression in such inaccessible tissues (hypothalamus, ovary and liver). For this, 18 great tit (Parus major) females were sacrificed at three time points (n = 6 per time point) throughout the pre-laying and egg-laying period and their blood, hypothalamus, ovary and liver were sampled. Results We simultaneously assessed DNA methylation changes (via reduced representation bisulfite sequencing) and changes in gene expression (via RNA-seq and qPCR) over time. In general, we found a positive correlation between changes in CpG site methylation in RBCs and liver across timepoints. For CpG sites in close proximity to the transcription start site, an increase in RBC methylation over time was associated with a decrease in the expression of the associated gene in the ovary. In contrast, no such association with gene expression was found for CpG site methylation within the gene body or the 10 kb up- and downstream regions adjacent to the gene body. Conclusion Temporal changes in DNA methylation are largely tissue-general, indicating that changes in RBC methylation can reflect changes in DNA methylation in other, often less accessible, tissues such as the liver in our case. However, associations between temporal changes in DNA methylation with changes in gene expression are mostly tissue- and genomic location-dependent. The observation that temporal changes in DNA methylation within RBCs can relate to changes in gene expression in less accessible tissues is important for a better understanding of how environmental conditions shape traits that temporally change in expression in wild populations.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Angela M. Crist ◽  
Kelly M. Hinkle ◽  
Xue Wang ◽  
Christina M. Moloney ◽  
Billie J. Matchett ◽  
...  

AbstractSelective vulnerability of different brain regions is seen in many neurodegenerative disorders. The hippocampus and cortex are selectively vulnerable in Alzheimer’s disease (AD), however the degree of involvement of the different brain regions differs among patients. We classified corticolimbic patterns of neurofibrillary tangles in postmortem tissue to capture extreme and representative phenotypes. We combined bulk RNA sequencing with digital pathology to examine hippocampal vulnerability in AD. We identified hippocampal gene expression changes associated with hippocampal vulnerability and used machine learning to identify genes that were associated with AD neuropathology, including SERPINA5, RYBP, SLC38A2, FEM1B, and PYDC1. Further histologic and biochemical analyses suggested SERPINA5 expression is associated with tau expression in the brain. Our study highlights the importance of embracing heterogeneity of the human brain in disease to identify disease-relevant gene expression.


2011 ◽  
Vol 2 (4) ◽  
Author(s):  
Sarah Wilson ◽  
Tianli Zhu ◽  
Rajesh Khanna ◽  
Michael Pritz

AbstractGene expression was investigated in the major brain subdivisions (telencephalon, diencephalon, midbrain and hindbrain) in a representative reptile, Alligator mississipiensis, during the later stages of embryonic development. The following genes were examined: voltage-gated sodium channel isoforms: NaV1.1 and NaV1.2; synaptic vesicle 2a (SV2a); synaptophysin; and calbindin 2. With the exception of synaptophysin, which was only expressed in the telencephalon, all genes were expressed in all brain regions sampled at the time periods examined. For NaV1.1, gene expression varied according to brain area sampled. When compared with NaV1.1, the pattern of NaV1.2 gene expression differed appreciably. The gene expression of SV2a was the most robust of any of the genes examined. Of the other genes examined, although differences were noted, no statistically significant changes were found either between brain part or time interval. Although limited, the present analysis is the first quantitative mRNA gene expression study in any reptile during development. Together with future experiments of a similar nature, the present gene expression results should determine which genes are expressed in major brain areas at which times during development in Alligator. When compared with other amniotes, these results will prove useful for determining how gene expression during development influences adult brain structure.


Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 3012
Author(s):  
Dhanush Haspula ◽  
Michelle A. Clark

Angiotensin (Ang) II is well-known to have potent pro-oxidant and pro-inflammatory effects in the brain. Extensive crosstalk between the primary Ang II receptor, Ang type 1 receptor (AT1R), and the cannabinoid type 1 receptor (CB1R) has been demonstrated by various groups in the last decade. Since activation of glial CB1R has been demonstrated to play a key role in the resolution of inflammatory states, we investigated the role of Ang II (100 nM) and/or ACEA (10 nM), a potent CB1R-specific agonist in the regulation of inflammatory markers in astrocytes from spontaneously hypertensive rats (SHR) and Wistar rats. Astrocytes were cultured from brainstems and cerebellums of SHR and Wistar rats and assayed for IL1β and IL10 gene expression and secreted fraction, in treated and non-treated cells, by employing qPCR and ELISA, respectively. mRNA expression of both IL10 and IL1β were significantly elevated in untreated brainstem and cerebellar astrocytes isolated from SHR when compared to Wistar astrocytes. No changes were observed in the secreted fraction. While ACEA-treatment resulted in a significant increase in IL10 gene expression in Wistar brainstem astrocytes (Log2FC ≥ 1, p < 0.05), its effect in SHR brainstem astrocytes was diminished. Ang II treatment resulted in a strong inhibitory effect on IL10 gene expression in astrocytes from both brain regions of SHR and Wistar rats (Log2FC ≤ −1, p < 0.05), and an increase in IL1β gene expression in brainstem astrocytes from both strains (Log2FC ≥ 1, p < 0.05). Co-treatment of Ang II and ACEA resulted in neutralization of Ang II-mediated effect in Wistar brainstem and cerebellar astrocytes, but not SHR astrocytes. Neither Ang II nor ACEA resulted in any significant changes in IL10 or IL1β secreted proteins. These data suggest that Ang II and ACEA have opposing roles in the regulation of inflammatory gene signature in astrocytes isolated from SHR and Wistar rats. This however does not translate into changes in their secreted fractions.


2018 ◽  
Vol 4 (11) ◽  
pp. eaau9859 ◽  
Author(s):  
Michael J. Castle ◽  
Yuhsiang Cheng ◽  
Aravind Asokan ◽  
Mark H. Tuszynski

Several neurological disorders may benefit from gene therapy. However, even when using the lead vector candidate for intrathecal administration, adeno-associated virus serotype 9 (AAV9), the strength and distribution of gene transfer to the brain are inconsistent. On the basis of preliminary observations that standard intrathecal AAV9 infusions predominantly drive reporter gene expression in brain regions where gravity might cause cerebrospinal fluid to settle, we tested the hypothesis that counteracting vector “settling” through animal positioning would enhance vector delivery to the brain. When rats are either inverted in the Trendelenburg position or continuously rotated after intrathecal AAV9 infusion, we find (i) a significant 15-fold increase in the number of transduced neurons, (ii) a marked increase in gene delivery to cortical regions, and (iii) superior animal-to-animal consistency of gene expression. Entorhinal, prefrontal, frontal, parietal, hippocampal, limbic, and basal forebrain neurons are extensively transduced: 95% of transduced cells are neurons, and greater than 70% are excitatory. These findings provide a novel and simple method for broad gene delivery to the cortex and are of substantial relevance to translational programs for neurological disorders, including Alzheimer’s disease and related dementias, stroke, and traumatic brain injury.


2007 ◽  
Vol 97 (2) ◽  
pp. 389-398 ◽  
Author(s):  
Patricia Pérez-Matute ◽  
Nerea Pérez-Echarri ◽  
J. Alfredo Martínez ◽  
Amelia Marti ◽  
María J. Moreno-Aliaga

n-3 PUFA have shown potential anti-obesity and insulin-sensitising properties. However, the mechanisms involved are not clearly established. The aim of the present study was to assess the effects of EPA administration, one of the n-3 PUFA, on body-weight gain and adiposity in rats fed on a standard or a high-fat (cafeteria) diet. The actions on white adipose tissue lipolysis, apoptosis and on several genes related to obesity and insulin resistance were also studied. Control and cafeteria-induced overweight male Wistar rats were assigned into two subgroups, one of them daily received EPA ethyl ester (1 g/kg) for 5 weeks by oral administration. The high-fat diet induced a very significant increase in both body weight and fat mass. Rats fed with the cafeteria diet and orally treated with EPA showed a marginally lower body-weight gain (P = 0·09), a decrease in food intake (P < 0·01) and an increase in leptin production (P < 0·05). EPA administration reduced retroperitoneal adipose tissue weight (P < 0·05) which could be secondary to the inhibition of the adipogenic transcription factor PPARγ gene expression (P < 0·001), and also to the increase in apoptosis (P < 0·05) found in rats fed with a control diet. TNFα gene expression was significantly increased (P < 0·05) by the cafeteria diet, while EPA treatment was able to prevent (P < 0·01) the rise in this inflammatory cytokine. Adiposity-corrected adiponectin plasma levels were increased by EPA. These actions on both TNFα and adiponectin could explain the beneficial effects of EPA on insulin resistance induced by the cafeteria diet.


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