scholarly journals RhANP attenuates endotoxin-derived cognitive dysfunction through subdiaphragmatic vagus nerve-mediated gut microbiota–brain axis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Yuming Wu ◽  
Yujing Zhang ◽  
Bing Xie ◽  
Amro Abdelgawad ◽  
Xiaoyan Chen ◽  
...  

Abstract Background Atrial natriuretic peptide (ANP) secreted from atrial myocytes is shown to possess anti-inflammatory, anti-oxidant and immunomodulatory effects. The aim of this study is to assess the effect of ANP on bacterial lipopolysaccharide (LPS)-induced endotoxemia-derived neuroinflammation and cognitive impairment. Methods LPS (5 mg/kg) was given intraperitoneally to mice. Recombinant human ANP (rhANP) (1.0 mg/kg) was injected intravenously 24 h before and/or 10 min after LPS injection. Subdiaphragmatic vagotomy (SDV) was performed 14 days before LPS injection or 28 days before fecal microbiota transplantation (FMT). ANA-12 (0.5 mg/kg) was administrated intraperitoneally 30 min prior to rhANP treatment. Results LPS (5.0 mg/kg) induced remarkable splenomegaly and an increase in the plasma cytokines at 24 h after LPS injection. There were positive correlations between spleen weight and plasma cytokines levels. LPS also led to increased protein levels of ionized calcium-binding adaptor molecule (iba)-1, cytokines and inducible nitric oxide synthase (iNOS) in the hippocampus. LPS impaired the natural and learned behavior, as demonstrated by an increase in the latency to eat the food in the buried food test and a decrease in the number of entries and duration in the novel arm in the Y maze test. Combined prophylactic and therapeutic treatment with rhANP reversed LPS-induced splenomegaly, hippocampal and peripheral inflammation as well as cognitive impairment. However, rhANP could not further enhance the protective effects of SDV on hippocampal and peripheral inflammation. We further found that PGF mice transplanted with fecal bacteria from rhANP-treated endotoxemia mice alleviated the decreased protein levels of hippocampal polyclonal phosphorylated tyrosine kinase receptor B (p-TrkB), brain-derived neurotrophic factor (BDNF) and cognitive impairment, which was abolished by SDV. Moreover, TrkB/BDNF signaling inhibitor ANA-12 abolished the improving effects of rhANP on LPS-induced cognitive impairment. Conclusions Our results suggest that rhANP could mitigate LPS-induced hippocampal inflammation and cognitive dysfunction through subdiaphragmatic vagus nerve-mediated gut microbiota–brain axis.

2021 ◽  
pp. 1-9
Author(s):  
Guizhen Liu ◽  
Yuchuan Sun ◽  
Fei Liu

<b><i>Objective:</i></b> The purpose of this study was to explore the role of curcumin (Cur) in isoflurane (ISO)-induced learning and memory dysfunction in Sprague-Dawley rats and further elucidate the mechanism of the protective effect produced by Cur. <b><i>Methods:</i></b> Rat models of cognitive impairment were established by inhaling 3% ISO. The Morris water maze test was used to assess the cognitive function of rats. ELISA and qRT-PCR were used to analyze the protein levels of pro-inflammatory cytokines and expression levels of miR-181a-5p, respectively. <b><i>Results:</i></b> Cur significantly improved the ISO-induced cognitive dysfunction in rats and alleviated the ISO-induced neuroinflammation. miR-181a-5p was overexpressed in ISO-induced rats, while Cur treatment significantly reduced the expression of miR-181a-5p. Overexpression of miR-181a-5p promoted the cognitive impairment and the release of inflammatory cytokines and reversed the neuroprotective effect of Cur. <b><i>Conclusion:</i></b> Cur has a protective effect on ISO-induced cognitive dysfunction, which may be achieved by regulating the expression of miR-181a-5p.


2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiao-Yu Sun ◽  
Teng Zheng ◽  
Xiu Yang ◽  
Le Liu ◽  
Shen-Shen Gao ◽  
...  

Abstract Background Inflammation can induce cognitive dysfunction in patients who undergo surgery. Previous studies have demonstrated that both acute peripheral inflammation and anaesthetic insults, especially isoflurane (ISO), are risk factors for memory impairment. Few studies are currently investigating the role of ISO under acute peri-inflammatory conditions, and it is difficult to predict whether ISO can aggravate inflammation-induced cognitive deficits. HDACs, which are essential for learning, participate in the deacetylation of lysine residues and the regulation of gene transcription. However, the cell-specific mechanism of HDACs in inflammation-induced cognitive impairment remains unknown. Methods Three-month-old C57BL/6 mice were treated with single versus combined exposure to LPS injected intraperitoneally (i.p.) to simulate acute abdominal inflammation and isoflurane to investigate the role of anaesthesia and acute peripheral inflammation in cognitive impairment. Behavioural tests, Western blotting, ELISA, immunofluorescence, qRT-PCR, and ChIP assays were performed to detect memory, the expressions of inflammatory cytokines, HDAC2, BDNF, c-Fos, acetyl-H3, microglial activity, Bdnf mRNA, c-fos mRNA, and Bdnf and c-fos transcription in the hippocampus. Results LPS, but not isoflurane, induced neuroinflammation-induced memory impairment and reduced histone acetylation by upregulating histone deacetylase 2 (HDAC2) in dorsal hippocampal CaMKII+ neurons. The hyperexpression of HDAC2 in neurons was mediated by the activation of microglia. The decreased level of histone acetylation suppressed the transcription of Bdnf and c-fos and the expressions of BDNF and c-Fos, which subsequently impaired memory. The adeno-associated virus ShHdac2, which suppresses Hdac2 after injection into the dorsal hippocampus, reversed microglial activation, hippocampal glutamatergic BDNF and c-Fos expressions, and memory deficits. Conclusions Reversing HDAC2 in hippocampal CaMKII+ neurons exert a neuroprotective effect against neuroinflammation-induced memory deficits.


2021 ◽  
Vol 13 ◽  
Author(s):  
Xiangfei Huang ◽  
Jun Ying ◽  
Danying Yang ◽  
Pu Fang ◽  
Xifeng Wang ◽  
...  

Sevoflurane is one of the most commonly used inhaled anesthetics due to its low blood gas coefficient, fast onset, low airway irritation, and aromatic smell. However, recent studies have reported that sevoflurane exposure may have deleterious effects on cognitive function. Although neuroinflammation was most widely mentioned among the established mechanisms of sevoflurane-induced cognitive dysfunction, its upstream mechanisms have yet to be illustrated. Thus, we reviewed the relevant literature and discussed the most mentioned mechanisms, including the modulation of the microglial function, blood–brain barrier (BBB) breakdown, changes in gut microbiota, and ease of cholinergic neurotransmission to help us understand the properties of sevoflurane, providing us new perspectives for the prevention of sevoflurane-induced cognitive impairment.


2019 ◽  
Vol 31 (04) ◽  
pp. 551-560 ◽  
Author(s):  
Eleanor King ◽  
John Tiernan O’Brien ◽  
Paul Donaghy ◽  
Christopher Morris ◽  
Nicola Barnett ◽  
...  

ABSTRACTObjectives and design:To Investigate the peripheral inflammatory profile in patients with mild cognitive impairment (MCI) from three subgroups – probable Lewy body disease (probable MCI-LB), possible Lewy body disease, and probable Alzheimer’s disease (probable MCI-AD) – as well as associations with clinical features.Setting:Memory clinics and dementia services.Participants:Patients were classified based on clinical symptoms as probable MCI-LB (n = 38), possible MCI-LB (n = 18), and probable MCI-AD (n = 21). Healthy comparison subjects were recruited (n = 20).Measurements:Ten cytokines were analyzed from plasma samples: interferon (IFN)-gamma, interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, and tumor necrosis factor (TNF)-alpha. C-reactive protein levels were investigated.Results:There was a higher level of IL-10, IL-1beta, IL-2, and IL-4 in MCI groups compared to the healthy comparison group (p &lt; 0.0085). In exploratory analyses to understand these findings, the MC-AD group lower IL-1beta (p = 0.04), IL-2 (p = 0.009), and IL-4 (p = 0.012) were associated with increasing duration of memory symptoms, and in the probable MCI-LB group, lower levels of IL-1beta were associated with worsening motor severity (p = 0.002). In the possible MCI-LB, longer duration of memory symptoms was associated with lower levels of IL-1beta (p = 0.003) and IL-4 (p = 0.026).Conclusion:There is increased peripheral inflammation in patients with MCI compared to healthy comparison subjects regardless of the MCI subtype. These possible associations with clinical features are consistent with other work showing that inflammation is increased in early disease but require replication. Such findings have importance for timing of putative therapeutic strategies aimed at lowering inflammation.


2020 ◽  
Vol 45 (2) ◽  
Author(s):  
Arpita Chakraborty ◽  
Samir Kumar Praharaj ◽  
R. V. Krishnananda Prabhu ◽  
M. Mukhyaprana Prabhu

AbstractBackgroundMore than half portion of the brain is formed by lipids. They play critical roles in maintaining the brain's structural and functional components. Any dysregulation in these brain lipids can lead to cognitive dysfunction which are associated with neurological disorders such as Alzheimer's disease, Parkinson's disease, schizophrenia, vascular dementia etc. Studies have linked lipids with cognitive impairment. But not much has been studied about the complex brain lipids which might play a pivotal role in cognitive impairment. This review aims to highlight the lipidomic profiles in patients with cognitive dysfunction.ResultsForty-five articles were reviewed. These studies show alterations in complex lipids such as sphingolipids, phospholipids, glycolipids and sterols in brain in various neurological disorders such as vascular dementia, Parkinson's and Alzheimer's disease. However, the classes of fatty acids in these lipids involved are different across studies.ConclusionsThere is a need for targeted lipidomics analysis, specifically including sphingolipids in patients with neurodegenerative disorders so as to improve diagnostics as well as management of these disorders.


2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Mohamed W. Zakaria ◽  
Reem I. El-Korashy ◽  
Mostafa O. Shaheen ◽  
Samah Selim ◽  
Kwashi J. Amum

Abstract Background Cognitive dysfunction in idiopathic interstitial pneumonia (IIP) is an important clinical co-morbidity that is associated with impaired lung function. The aim of the work is to assess cognitive function in major IIP and to find out the relation between cognitive dysfunction and the oxygenation parameters. Results Fifty individuals were involved in the study; 30 patients with major IIP and 20 healthy individuals. Patients with IIP had significantly lower mini mental state examination (MMSE) score compared to the control group (P < 0.001). Wechsler Deterioration Index (WDI) revealed that 33.3% (n = 10) of the patients with IIP had sure cognitive impairment and 26.6% (n = 8) had ongoing cognitive deterioration. Patients with idiopathic pulmonary fibrosis (IPF) had lower cognitive function than other IIP. Conclusion There is an impairment of cognitive function in patients with major IIP, particularly in IPF, as measured by WDI and MMSE. Further large studies are needed to assess the possible predictors of cognitive impairment and their effects on the patients’ outcome.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Hong Zheng ◽  
Pengtao Xu ◽  
Qiaoying Jiang ◽  
Qingqing Xu ◽  
Yafei Zheng ◽  
...  

Abstract Background Modification of the gut microbiota has been reported to reduce the incidence of type 1 diabetes mellitus (T1D). We hypothesized that the gut microbiota shifts might also have an effect on cognitive functions in T1D. Herein we used a non-absorbable antibiotic vancomycin to modify the gut microbiota in streptozotocin (STZ)-induced T1D mice and studied the impact of microbial changes on cognitive performances in T1D mice and its potential gut-brain neural mechanism. Results We found that vancomycin exposure disrupted the gut microbiome, altered host metabolic phenotypes, and facilitated cognitive impairment in T1D mice. Long-term acetate deficiency due to depletion of acetate-producing bacteria resulted in the reduction of synaptophysin (SYP) in the hippocampus as well as learning and memory impairments. Exogenous acetate supplement or fecal microbiota transplant recovered hippocampal SYP level in vancomycin-treated T1D mice, and this effect was attenuated by vagal inhibition or vagotomy. Conclusions Our results demonstrate the protective role of microbiota metabolite acetate in cognitive functions and suggest long-term acetate deficiency as a risk factor of cognitive decline.


2015 ◽  
Vol 22 (4) ◽  
pp. 177-180 ◽  
Author(s):  
Huseyin Bayazit ◽  
Erdinc Cicek ◽  
Salih Selek ◽  
Nurten Aksoy ◽  
I. Fatih Karababa ◽  
...  

Background: It has been determined that cannabis has adverse effects on brain tissue, and that increased S100 calcium binding protein B (S100B) blood levels are markers of neuronal damage. Therefore, the aim of this study was to evaluate the S100B levels in cannabis use disorder. Method: Thirty-two patients with cannabis use disorder and 31 matched healthy controls were enrolled in this study. Appropriate blood samples were taken from the enrolled subjects, and the serum S100B protein levels were measured with an electrochemiluminescence immunoassay for the quantification of the protein. Findings: We found significantly increased S100B protein levels in patients with cannabis use disorder. The mean serum concentration of S100B was 0.081 ± 0.018 μg/l in patients with cannabis use disorder, and 0.069 ± 0.018 μg/l in the control group (p = 0.008). Interpretation: Our data suggest that elevated S100B protein levels might indicate neuronal damage in the brains of people with cannabis use disorder.


2021 ◽  
pp. 1-16
Author(s):  
Esteban Leyton ◽  
Diego Matus ◽  
Sandra Espinoza ◽  
José Matías Benitez ◽  
Bastián I. Cortes ◽  
...  

Background: Disturbances in the autophagy/endolysosomal systems are proposed as early signatures of Alzheimer’s disease (AD). However, few studies are available concerning autophagy gene expression in AD patients. Objective: To explore the differential expression of classical genes involved in the autophagy pathway, among them a less characterized one, DEF8 (Differentially expressed in FDCP 8), initially considered a Rubicon family member, in peripheral blood mononuclear cells (PBMCs) from individuals with mild cognitive impairment (MCI) and probable AD (pAD) and correlate the results with the expression of DEF8 in the brain of 5xFAD mice. Method: By real-time PCR and flow cytometry, we evaluated autophagy genes levels in PBMCs from MCI and pAD patients. We evaluated DEF8 levels and its localization in brain samples of the 5xFAD mice by real-time PCR, western blot, and immunofluorescence. Results: Transcriptional levels of DEF8 were significantly reduced in PBMCs of MCI and pAD patients compared with healthy donors, correlating with the MoCA and MoCA-MIS cognitive tests scores. DEF8 protein levels were increased in lymphocytes from MCI but not pAD, compared to controls. In the case of brain samples from 5xFAD mice, we observed a reduced mRNA expression and augmented protein levels in 5xFAD compared to age-matched wild-type mice. DEF8 presented a neuronal localization. Conclusion: DEF8, a protein proposed to act at the final step of the autophagy/endolysosomal pathway, is differentially expressed in PBMCs of MCI and pAD and neurons of 5xFAD mice. These results suggest a potential role for DEF8 in the pathophysiology of AD.


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