Cocaine-induced changes in behaviour and DNA methylation in rats are influenced by inter-individual differences in spontaneous exploratory activity

2020 ◽  
Vol 34 (6) ◽  
pp. 680-692 ◽  
Author(s):  
Kadi Vaher ◽  
Kaili Anier ◽  
Monika Jürgenson ◽  
Jaanus Harro ◽  
Anti Kalda

Background: Individual differences in behavioural traits influence susceptibility to addictive disorders. Drug addiction involves changes in gene expression, proposed to occur via DNA methylation (DNAm). Aims: To investigate DNAm changes in reward-related brain structures (nucleus accumbens (NAc), lateral habenula (LHb)) in response to cocaine exposure in rats differing in spontaneous exploratory activity. Methods: Rats were observed in the exploration box and categorised as high- (HE) or low explorers (LE). Rats were administered vehicle or cocaine (12 mg/kg, i.p.) for 7 days, followed by a 14-day withdrawal period and cocaine challenge (7 mg/kg); horizontal locomotor activity was recorded. Brain tissue was dissected after 24 h; we analysed messenger RNA (mRNA) and activity levels of epigenetic DNA modifiers (DNMTs and TETs) as well as mRNA and promoter methylation levels at selected genes previously linked to addictive behaviours. Results: The cocaine challenge dose stimulated locomotor activity in both LE- and HE rats only when administered after a repeated cocaine schedule, suggesting development of behavioural sensitisation. Quantitative polymerase chain reaction analyses demonstrated higher basal expression of Dnmt3a, Tet2 and Tet3 in the LHb of HE- vs. LE rats, and we observed differential effects of cocaine exposure on the expression and activity of epigenetic DNA modifiers in the NAc and LHb of HE- and LE rats. Furthermore, cocaine exposure differentially altered promoter methylation levels of A2AR, Ppp1cc, and Taar7b in the NAc and LHb of HE- and LE rats. Conclusions: DNAm might play a role in the HE- and LE phenotypes as well as mediate behavioural effects of LE- and HE rats in response to drugs of abuse.

2020 ◽  
pp. 1-10
Author(s):  
Louise Stögbauer ◽  
Christian Thomas ◽  
Andrea Wagner ◽  
Nils Warneke ◽  
Eva Christine Bunk ◽  
...  

OBJECTIVEChemotherapeutic options for meningiomas refractory to surgery or irradiation are largely unknown. Human telomerase reverse transcriptase (hTERT) promoter methylation with subsequent TERT expression and telomerase activity, key features in oncogenesis, are found in most high-grade meningiomas. Therefore, the authors investigated the impact of the demethylating agent decitabine (5-aza-2ʹ-deoxycytidine) on survival and DNA methylation in meningioma cells.METHODShTERT promoter methylation, telomerase activity, TERT expression, and cell viability and proliferation were investigated prior to and after incubation with decitabine in two benign (HBL-52 and Ben-Men 1) and one malignant (IOMM-Lee) meningioma cell line. The global effects of decitabine on DNA methylation were additionally explored with DNA methylation profiling.RESULTSHigh levels of TERT expression, telomerase activity, and hTERT promoter methylation were found in IOMM-Lee and Ben-Men 1 but not in HBL-52 cells. Decitabine induced a dose-dependent significant decrease of proliferation and viability after incubation with doses from 1 to 10 μM in IOMM-Lee but not in HBL-52 or Ben-Men 1 cells. However, effects in IOMM-Lee cells were not related to TERT expression, telomerase activity, or hTERT promoter methylation. Genome-wide methylation analyses revealed distinct demethylation of 14 DNA regions after drug administration in the decitabine-sensitive IOMM-Lee but not in the decitabine-resistant HBL-52 cells. Differentially methylated regions covered promoter regions of 11 genes, including several oncogenes and tumor suppressor genes that to the authors’ knowledge have not yet been described in meningiomas.CONCLUSIONSDecitabine decreases proliferation and viability in high-grade but not in benign meningioma cell lines. The effects of decitabine are TERT independent but related to DNA methylation changes of promoters of distinct tumor suppressor genes and oncogenes.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Zijian Chen ◽  
Zenghong Huang ◽  
Yanxin Luo ◽  
Qi Zou ◽  
Liangliang Bai ◽  
...  

Abstract Background Neurotrophic tropomyosin receptor kinases (NTRKs) are a gene family function as oncogene or tumor suppressor gene in distinct cancers. We aimed to investigate the methylation and expression profiles and prognostic value of NTRKs gene in colorectal cancer (CRC). Methods An analysis of DNA methylation and expression profiles in CRC patients was performed to explore the critical methylations within NTRKs genes. The methylation marker was validated in a retrospectively collected cohort of 229 CRC patients and tested in other tumor types from TCGA. DNA methylation status was determined by quantitative methylation-specific PCR (QMSP). Results The profiles in six CRC cohorts showed that NTRKs gene promoter was more frequently methylated in CRC compared to normal mucosa, which was associated with suppressed gene expression. We identified a specific methylated region within NTRK3 promoter targeted by cg27034819 and cg11525479 that best predicted survival outcome in CRC. NTRK3 promoter methylation showed independently predictive value for survival outcome in the validation cohort (P = 0.004, HR 2.688, 95% CI [1.355, 5.333]). Based on this, a nomogram predicting survival outcome was developed with a C-index of 0.705. Furthermore, the addition of NTRK3 promoter methylation improved the performance of currently-used prognostic model (AIC: 516.49 vs 513.91; LR: 39.06 vs 43.64, P = 0.032). Finally, NTRK3 promoter methylation also predicted survival in other tumors, including pancreatic cancer, glioblastoma and stomach adenocarcinoma. Conclusions This study highlights the essential value of NTRK3 methylation in prognostic evaluation and the potential to improve current prognostic models in CRC and other tumors.


2019 ◽  
Vol 26 (12) ◽  
pp. 1618-1625 ◽  
Author(s):  
Xue Shen ◽  
Hua Duan ◽  
Sha Wang ◽  
Wei Hong ◽  
Yu-Yan Wang ◽  
...  

The myometrium, especially the junctional zone (JZ), is now well documented to have a role in the pathogenesis of adenomyosis. Cannabinoid receptors have been shown to participate in the establishment of endometriosis and its pain perception. However, its relation to adenomyosis has not been identified yet. The aim of this study was to investigate the expression of cannabinoid receptor type I (CB1) and type II (CB2) in myometrium of uteri with and without adenomyosis and determine the correlation between their levels and clinical parameters of adenomyosis. We collected tissue samples of JZ and the outer myometrium from 45 premenopausal women with adenomyosis and 34 women without adenomyosis. CB1 and CB2 messenger RNA (mRNA) and protein expression levels were evaluated by the use of Western blotting and real-time quantitative polymerase chain reaction from all samples. Clinical information on the severity of dysmenorrhea and other data were collected. We found both CB1 and CB2 mRNA and protein levels in women with adenomyosis were significantly higher than those of controls, and CB1 expression levels in JZ were positively correlated with the severity of dysmenorrhea. These data suggest that cannabinoid receptor CB1 may be involved in the pathogenesis of dysmenorrhea in adenomyosis and may be a potential therapeutic target.


2017 ◽  
Vol 102 (12) ◽  
pp. 4588-4595 ◽  
Author(s):  
Natalia Hetemäki ◽  
Hanna Savolainen-Peltonen ◽  
Matti J Tikkanen ◽  
Feng Wang ◽  
Hanna Paatela ◽  
...  

Abstract Context In postmenopausal women, adipose tissue (AT) levels of estrogens exceed circulating concentrations. Although increased visceral AT after menopause is related to metabolic diseases, little is known about differences in estrogen metabolism between different AT depots. Objective We compared concentrations of and metabolic pathways producing estrone and estradiol in abdominal subcutaneous and visceral AT in postmenopausal women. Design, Setting, Patients, and Interventions AT and serum samples were obtained from 37 postmenopausal women undergoing surgery for nonmalignant gynecological reasons. Serum and AT estrone, estradiol, and serum estrone sulfate (E1S) concentrations were quantitated using liquid chromatography-tandem mass spectrometry. Activity of steroid sulfatase and reductive 17β-hydroxysteroid dehydrogenase enzymes was measured using radiolabeled precursors. Messenger RNA (mRNA) expression of estrogen-converting enzymes was analyzed by real-time reverse transcription quantitative polymerase chain reaction. Results Estrone concentration was higher in visceral than subcutaneous AT (median, 928 vs 706 pmol/kg; P = 0.002) and correlated positively with body mass index (r = 0.46; P = 0.011). Both AT depots hydrolyzed E1S to estrone, and visceral AT estrone and estradiol concentrations correlated positively with serum E1S. Compared with visceral AT, subcutaneous AT produced more estradiol from estrone (median rate of estradiol production, 1.02 vs 0.57 nmol/kg AT/h; P = 0.004). In visceral AT, the conversion of estrone to estradiol increased with waist circumference (r = 0.65; P = 0.022), and estradiol concentration correlated positively with mRNA expression of HSD17B7 (r = 0.76; P = 0.005). Conclusions Both estrone and estradiol production in visceral AT increased with adiposity, but estradiol was produced more effectively in subcutaneous fat. Both AT depots produced estrone from E1S. Increasing visceral adiposity could increase overall estrogen exposure in postmenopausal women.


2009 ◽  
Vol 117 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Letizia Tarantini ◽  
Matteo Bonzini ◽  
Pietro Apostoli ◽  
Valeria Pegoraro ◽  
Valentina Bollati ◽  
...  

2015 ◽  
Vol 6 (6) ◽  
pp. 558-572 ◽  
Author(s):  
D. J. Carr ◽  
J. S. Milne ◽  
R. P. Aitken ◽  
C. L. Adam ◽  
J. M. Wallace

Intrauterine growth restriction (IUGR) and postnatal catch-up growth confer an increased risk of adult-onset disease. Overnourishment of adolescent ewes generates IUGR in ∼50% of lambs, which subsequently exhibit increased fractional growth rates. We investigated putative epigenetic changes underlying this early postnatal phenotype by quantifying gene-specific methylation at cytosine:guanine (CpG) dinucleotides. Hepatic DNA/RNA was extracted from IUGR [eight male (M)/nine female (F)] and normal birth weight (12 M/9 F) lambs. Polymerase chain reaction was performed using primers targeting CpG islands in 10 genes: insulin, growth hormone, insulin-like growth factor (IGF)1, IGF2, H19, insulin receptor, growth hormone receptor, IGF receptors 1 and 2, and the glucocorticoid receptor. Using pyrosequencing, methylation status was determined by quantifying cytosine:thymine ratios at 57 CpG sites. Messenger RNA (mRNA) expression of IGF system genes and plasma IGF1/insulin were determined. DNA methylation was independent of IUGR status but sexual dimorphism in IGF1 methylation was evident (M<F, P=0.008). IGF1 mRNA:18S and plasma IGF1 were M>F (both P<0.001). IGF1 mRNA expression correlated negatively with IGF1 methylation (r=−0.507, P=0.002) and positively with plasma IGF1 (r=0.884, P<0.001). Carcass and empty body weights were greater in males (P=0.002–0.014) and this gender difference in early body conformation was mirrored by sexual dimorphism in hepatic IGF1 DNA methylation, mRNA expression and plasma IGF1 concentrations.


Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831770163 ◽  
Author(s):  
Snigdha Saikia ◽  
Asad Ur Rehman ◽  
Prajjalendra Barooah ◽  
Preeti Sarmah ◽  
Mallika Bhattacharyya ◽  
...  

Promoter methylation reflects in the inactivation of different genes like O6-methylguanine-DNA methyltransferase DNA repair gene and runt-related transcription factor 3, a known tumor suppressor gene in various cancers such as esophageal cancer. The promoter methylation was evaluated for O6-methylguanine-DNA methyltransferase and runt-related transcription factor 3 in CpG, CHH, and CHG context (where H is A, T, or C) by next-generation sequencing. The methylation status was correlated with quantitative messenger RNA expression. In addition, messenger RNA expression was correlated with different risk factors like tobacco, alcohol, betel nut consumption, and smoking habit. CpG methylation of O6-methylguanine-DNA methyltransferase promoter had a positive association in the development of esophageal cancer (p < 0.05), whereas runt-related transcription factor 3 promoter methylation showed no significant association (p = 1.0) to develop esophageal cancer. However, the non-CpG methylation, CHH, and CHG were significantly correlated with O6-methylguanine-DNA methyltransferase (p < 0.05) and runt-related transcription factor 3 (p < 0.05) promoters in the development of esophageal cancer. The number of cytosine converted to thymine (C→T) in O6-methylguanine-DNA methyltransferase promoter showed a significant correlation between cases and controls (p < 0.05), but in runt-related transcription factor 3 no such significant correlation was observed. Besides, messenger RNA expression was found to be significantly correlated with promoter hypermethylation of O6-methylguanine-DNA methyltransferase and runt-related transcription factor 3 in the context of CHG and CHH (p < 0.05). The CpG hypermethylation in O6-methylguanine-DNA methyltransferase showed positive (p < 0.05) association, whereas in runt-related transcription factor 3, it showed contrasting negative association (p = 0.23) with their messenger RNA expression. Tobacco, betel nut consumption, and smoking habits were associated with altered messenger RNA expression of O6-methylguanine-DNA methyltransferase (p < 0.05) and betel nut consumption and smoking habits were associated with runt-related transcription factor 3 (p < 0.05). There was no significant association between messenger RNA expression of O6-methylguanine-DNA methyltransferase and runt-related transcription factor 3 with alcohol consumption (p = 0.32 and p = 0.15). In conclusion, our results suggest that an aberrant messenger RNA expression may be the outcome of CpG, CHG, and CHH methylation in O6-methylguanine-DNA methyltransferase, whereas outcome of CHG and CHH methylation in runt-related transcription factor 3 promoters along with risk factors such as consumption of tobacco, betel nut, and smoking habits in esophageal cancer from Northeast India.


1975 ◽  
Vol 36 (3) ◽  
pp. 935-940
Author(s):  
Kenneth J. Wilz

In two separate experiments the locomotor activity of gerbils ( Ns = 16) was studied in an open field. The subjects were allowed to explore the field and were then returned to the same or an identical one. These were either contaminated or not with the organism's recent odor trail, though visually identical. Considerably less exploratory activity occurred when the field still contained the odor trail set out during the previous exploration. It is argued that the olfactory “marking” operates as a negative feedback device by limiting activity in a previously explored environment.


2018 ◽  
Vol 40 (01) ◽  
pp. 62-70 ◽  
Author(s):  
Alexander Schenk ◽  
Walter Pulverer ◽  
Christine Koliamitra ◽  
Claus Bauer ◽  
Suzana Ilic ◽  
...  

AbstractPositive effects of exercise on cancer prevention and progression have been proposed to be mediated by stimulating natural killer (NK) cells. Because NK cell receptors are regulated by epigenetic modifications, we investigated whether acute aerobic exercise and training change promoter DNA methylation and gene expression of the activating KIR2DS4 and the inhibiting KIR3DL1 gene. Sixteen healthy women (50–60 years) performed a graded exercise test (GXT) and were randomized into either a passive control group or an intervention group performing a four-week endurance exercise intervention. Blood samples (pre-, post-GXT and post-training) were used for isolation of DNA/RNA of NK cells to assess DNA promoter methylation by targeted deep-amplicon sequencing and gene expression by qRT-PCR. Potential changes in NK cell subsets were determined by flow cytometry. Acute and chronic exercise did not provoke significant alterations of NK cell proportions. Promoter methylation decreased and gene expression increased for KIR2DS4 after acute exercise. A high gene expression correlated with a low methylation of CpGs that were altered by acute exercise. Chronic exercise resulted in a minor decrease of DNA methylation and did not alter gene expression. Acute exercise provokes epigenetic modifications, affecting the balance between the activating KIR2DS4 and the inhibiting KIR3DL1, with potential benefits on NK cell function.


Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 410 ◽  
Author(s):  
Daniel Castellano-Castillo ◽  
Isabel Moreno-Indias ◽  
Jose Carlos Fernandez-Garcia ◽  
Mercedes Clemente-Postigo ◽  
Manuel Castro-Cabezas ◽  
...  

Epigenetic marks, and especially DNA methylation, are becoming an important factor in obesity, which could help to explain its etiology and associated comorbidities. Adipose tissue, now considered as an important endocrine organ, produces complement system factors. Complement component 3 (C3) turns out to be an important protein in metabolic disorders, via either inflammation or the C3 subproduct acylation stimulating protein (ASP) which directly stimulates lipid storage. In this study, we analyze C3 DNA methylation in adipose tissue from subjects with a different grade of obesity. Adipose tissue samples were collected from subjects with a different degree of obesity determined by their body mass index (BMI) as: Overweight subjects (BMI ≥ 25 and <30), obese class 1/2 subjects (BMI ≥ 30 and <40) and obese class 3 subjects (BMI ≥ 40). C3 DNA methylation was measured for 7 CpGs by pyrosequencition using the Pyromark technology (Qiagen, Madrid Spain). C3 messenger RNA (mRNA) levels were analyzed by pre-designed Taqman assays (Applied biosystems, Foster City, CA, USA) and ASP/C3a was measured using a ELISA kit. The data were analyzed using the statistic package SPSS. C3 DNA methylation levels were lower in the morbid obese group. Accordingly, C3 methylation correlated negatively with BMI and leptin. However, C3 mRNA levels were more associated with insulin resistance, and positive correlations with insulin, glucose and homeostasis model assessment-estimated insulin resistance (HOMA-IR) existed. ASP correlated negatively with high density lipoprotein (HDL) cholesterol. C3 methylation levels were associated to adiposity variables, such as BMI and leptin, while the C3 mRNA levels were associated to glucose metabolism.


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