scholarly journals Protease-activated receptor 2 activation induces behavioural changes associated with depression-like behaviour through microglial-independent modulation of inflammatory cytokines

Author(s):  
Serge Moudio ◽  
Ashleigh Willis ◽  
Karolina Pytka ◽  
Roua Abulkassim ◽  
Ros R. Brett ◽  
...  

Abstract Rationale Major depressive disorder (MDD) is a leading cause of disability worldwide but currently prescribed treatments do not adequately ameliorate the disorder in a significant portion of patients. Hence, a better appreciation of its aetiology may lead to the development of novel therapies. Objectives In the present study, we have built on our previous findings indicating a role for protease-activated receptor-2 (PAR2) in sickness behaviour to determine whether the PAR2 activator, AC264613, induces behavioural changes similar to those observed in depression-like behaviour. Methods AC264613-induced behavioural changes were examined using the open field test (OFT), sucrose preference test (SPT), elevated plus maze (EPM), and novel object recognition test (NOR). Whole-cell patch clamping was used to investigate the effects of PAR2 activation in the lateral habenula with peripheral and central cytokine levels determined using ELISA and quantitative PCR. Results Using a blood–brain barrier (BBB) permeable PAR2 activator, we reveal that AC-264613 (AC) injection leads to reduced locomotor activity and sucrose preference in mice but is without effect in anxiety and memory-related tasks. In addition, we show that AC injection leads to elevated blood sera IL-6 levels and altered cytokine mRNA expression within the brain. However, neither microglia nor peripheral lymphocytes are the source of these altered cytokine profiles. Conclusions These data reveal that PAR2 activation results in behavioural changes often associated with depression-like behaviour and an inflammatory profile that resembles that seen in patients with MDD and therefore PAR2 may be a target for novel antidepressant therapies.

Author(s):  
Jessica MacGregor

gene in humans have been shown to predict non-responsiveness to antidepressant drugs; suggesting that FGF2 is required for antidepressants to work. In this study, we hypothesized that antidepressants will not work in rodents that lack the FGF2 gene. Hence, we tested antidepressant treatment in transgenic mice that had the FGF2 gene knocked out. Chronic unpredictable stress (CUS) has been used for several decades to produce a reliable depressive and anxious phenotype in mice. This study followed a CUS paradigm and used fluoxetine (Prozac) as antidepressant treatment. Mice received daily fluoxetine administration beginning on week three of CUS and continued until the end of week five to provide an antidepressant effect and reverse the effects of stress. To test for levels of anxiety and depression, a battery of behavioral tests was conducted which began from the least stressful (i.e. sucrose preference test, open field maze, elevated plus maze) to the most stressful test (forced swim test) to prevent testing carry-over effects. AnyMaze software was used to measure behavior in the open field and elevated plus mazes by recording the amount of time each mouse spent in certain parts of the maze. Future studies will examine brain changes associated with FGF2 gene deletion – particularly in astrocyte cells – which might be necessary for successful antidepressant action. Hopefully, this will elucidate novel therapeutic targets for antidepressant and anti-anxiety medication. 


2011 ◽  
Vol 115 (4) ◽  
pp. 812-821 ◽  
Author(s):  
Jing Wang ◽  
Yossef Goffer ◽  
Duo Xu ◽  
David S. Tukey ◽  
D. B. Shamir ◽  
...  

Background Chronic pain is associated with depression. In rodents, pain is often assessed by sensory hypersensitivity, which does not sufficiently measure affective responses. Low-dose ketamine has been used to treat both pain and depression, but it is not clear whether ketamine can relieve depression associated with chronic pain and whether this antidepressant effect depends on its antinociceptive properties. Methods The authors examined whether the spared nerve injury model of neuropathic pain induces depressive behavior in rats, using sucrose preference test and forced swim test, and tested whether a subanesthetic dose of ketamine treats spared nerve injury-induced depression. Results Spared nerve injury-treated rats, compared with control rats, showed decreased sucrose preference (0.719 ± 0.068 (mean ± SEM) vs. 0.946 ± 0.010) and enhanced immobility in the forced swim test (107.3 ± 14.6s vs. 56.2 ± 12.5s). Further, sham-operated rats demonstrated depressive behaviors in the acute postoperative period (0.790 ± 0.062 on postoperative day 2). A single subanesthetic dose of ketamine (10 mg/kg) did not alter spared nerve injury-induced hypersensitivity; however, it treated spared nerve injury-associated depression-like behaviors (0.896 ± 0.020 for ketamine vs. 0.663 ± 0.080 for control rats 1 day after administration; 0.858 ± 0.017 for ketamine vs. 0.683 ± 0.077 for control rats 5 days after administration). Conclusions Chronic neuropathic pain leads to depression-like behaviors. The postoperative period also confers vulnerability to depression, possibly due to acute pain. Sucrose preference test and forced swim test may be used to compliment sensory tests for assessment of pain in animal studies. Low-dose ketamine can treat depression-like behaviors induced by chronic neuropathic pain.


2018 ◽  
Vol 13 (7) ◽  
pp. 1686-1698 ◽  
Author(s):  
Meng-Ying Liu ◽  
Chun-Yu Yin ◽  
Li-Juan Zhu ◽  
Xian-Hui Zhu ◽  
Chu Xu ◽  
...  

Author(s):  
DINESH DHINGRA ◽  
SUDHA

Objectives: The present study was undertaken to investigate the antidepressant potential of trans-anethole in unstressed and stressed male mice. Methods: Swiss albino male mice were exposed to chronic unpredictable mild stress for 21 successive days. Simultaneously, trans-anethole (12.5 mg/kg, 25 mg/kg, and 50 mg/kg) and fluoxetine (20 mg/kg) per se were administered for 21 successive days to separate groups of unstressed and stressed mice. The effect of drugs on depressive-like behavior of mice was tested by tail suspension test (TST) and sucrose preference test. Results: Trans-anethole (25 mg/kg) and fluoxetine significantly decreased the immobility period of unstressed and stressed mice in TST as compared to their respective control. These drugs significantly restored the reduced sucrose preference (%) in stressed mice. Trans-anethole did not show any significant effect on locomotor activity of mice. Antidepressant-like activity of trans-anethole (25 mg/kg) was found to be comparable to fluoxetine. Trans-anethole and fluoxetine significantly inhibited brain monoamine oxidase-A (MAO-A) activity, decreased plasma nitrite, brain malondialdehyde, and increased brain reduced glutathione levels and catalase activity in unstressed and stressed mice. The drugs significantly reversed stress-induced increase in plasma corticosterone levels. Conclusion: Trans-anethole produced significant antidepressant-like activity in unstressed and stressed mice, possibly through inhibition of brain MAO-A activity and alleviation of oxidative stress. Reversal of stress-induced increase in plasma corticosterone levels might also be responsible for antidepressant-like activity of trans-anethole in stressed mice.


2020 ◽  
Vol 3 (Supplement_1) ◽  
pp. 59-60
Author(s):  
J Hanuschak ◽  
M P Louis-Auguste ◽  
G De Palma ◽  
E Verdu ◽  
R Anglin ◽  
...  

Abstract Background Major depressive disorder (MDD) affects approximately 4.4% of the global population. Despite its high prevalence, little is known about the mechanisms underlying this disorder. Recent studies in both humans and rodents have suggested that the intestinal microbiota may play a role in depression. Altered microbiota composition has been found in a subset of MDD patients. Preclinical studies have suggested that fecal microbiota transplant using pooled MDD patient samples can induce depressive-like behaviour in rodents. We have previously shown that the use of different microbiota donors with irritable bowel syndrome results in the induction of different phenotypes in recipient mice. Thus, we have hypothesized that pooling microbiota samples abrogates features that are unique to individual donors. Aims (1) Investigate whether the transfer of individual MDD patient microbiota can induce depressive-like behaviour in germ-free (GF) mice (2) Identify features of individual MDD patient microbiota that are associated with the depressive-like phenotype Methods GF NIH Swiss mice of both sexes (min. n=10 per group, total n=110) were colonized with either fecal microbiota from a single donor, MDD patient (MDD1-4) or matched healthy control (HC1-4), or pooled fecal microbiota from MDD1-4 or HC1-4. Mouse behaviour was assessed, using the open field test, three chamber sociability assay, tail suspension test, and sucrose preference test. Stool samples were collected throughout the experiment for 16S rRNA gene sequencing. Results Mice colonized with microbiota from patient MDD1 exhibited depressive-like behaviour, as assessed by the sucrose preference test and sociability assay, when compared to mice colonized with HC1 microbiota. This was not true for mice colonized with individual microbiota from the other three patients (MDD2-4) or with pooled MDD microbiota. Comparative analysis of the 16S data revealed a significant difference in Faith’s Phylogenetic Diversity between MDD1 microbiota and pooled MDD microbiota. Four bacterial species were found to be significantly associated with the depressive-like phenotype in mice: Bacteroides acidifaciens, Bacteroides ovatus, unclassified species of Phascolarctobacterium (Veillonellacae family), and Eggerthella lenta. The relative abundances of these species did not differ significantly between the two pooled groups. Conclusions Microbiota from some, but not all, MDD patients can induce a depressive-like phenotype in GF mice. The ability to induce depressive-like behaviour in GF mice is lost when microbiota from multiple patients is pooled. Specific bacterial species may be responsible for the successful transfer of the depressive-like phenotype to mice. Funding Agencies NIH


2021 ◽  
Vol 22 (14) ◽  
pp. 7483
Author(s):  
Vlad Dionisie ◽  
Adela Magdalena Ciobanu ◽  
Vlad Alexandru Toma ◽  
Mihnea Costin Manea ◽  
Ioana Baldea ◽  
...  

In recent years, escitalopram (ESC) has been suggested to have different mechanisms of action beyond its well known selective serotonin reuptake inhibition. The aim of this study is to investigate the effects of escitalopram on oxidative stress, apoptosis, brain-derived neurotrophic factor (BDNF), Methyl-CpG-binding protein 2 (MeCP2), and oligodendrocytes number in the brain of chronic unpredictable mild stress-induced depressed rats. The animals were randomised in four groups (8 in each group): control, stress, stress + ESC 5 and stress + ESC 5/10. ESC was administered for 42 days in a fixed dose (5 mg/kg b.w.) or in an up-titration regimen (21 days ESC 5 mg/kg b.w. then 21 days ESC 10 mg/kg b.w.). Sucrose preference test (SPT) and elevated plus maze (EPM) were also performed. ESC improved the percentage of sucrose preference, locomotion and anxiety. ESC5/10 reduced the oxidative damage in the hippocampus and improved the antioxidant defence in the hippocampus and frontal lobe. ESC5/10 lowered caspase 3 activity in the hippocampus. Escitalopram had a modulatory effect on BDNF and the number of oligodendrocytes in the hippocampus and frontal lobe and also improved the MeCP2 expressions. The results confirm the multiple pathways implicated in the pathogenesis of depression and suggest that escitalopram exerts an antidepressant effect via different intricate mechanisms.


BIO-PROTOCOL ◽  
2016 ◽  
Vol 6 (19) ◽  
Author(s):  
Tsvetan Serchov ◽  
Dietrich van Calker ◽  
Knut Biber

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