Background The gut-brain axis and the intestinal microbiota are emerging as key players in health and disease. Shifts in intestinal microbiota composition affect a variety of systems; however, evidence of their direct impact on cognitive functions is still lacking. We tested whether faecal microbiota transplant (FMT) from aged donor mice into young adult recipients altered the hippocampus, an area of the central nervous system (CNS) known to be affected by the ageing process and related functions. Results Young adult mice were transplanted with the microbiota from either aged or age-matched donor mice. Following transplantation, characterization of the microbiotas and metabolomics profiles along with a battery of cognitive and behavioural tests were performed. Label-free quantitative proteomics was employed to monitor protein expression in the hippocampus of the recipients. We report that FMT from aged donors led to impaired spatial learning and memory in young adult recipients, whereas anxiety, explorative behaviour and locomotor activity remained unaffected. This was paralleled by altered expression of proteins involved in synaptic plasticity and neurotransmission in the hippocampus. Also, a strong reduction of bacteria associated with short-chain fatty acids (SCFAs) production (Lachnospiraceae, Faecalibaculum, and Ruminococcaceae) and disorders of the CNS (Prevotellaceae and Ruminococcaceae) was observed. Finally, the detrimental effect of FMT from aged donors on the CNS was confirmed by the observation that microglia cells of the hippocampus fimbria, acquired an ageing-like phenotype; on the contrary, gut permeability and levels of systemic and local (hippocampus) cytokines were not affected. Conclusion These results demonstrate that age-associated shifts of the microbiota have an impact on protein expression and key functions of the CNS. Furthermore, these results highlight the paramount importance of the gut-brain axis in ageing and provide a strong rationale to devise therapies aiming to restore a young-like microbiota to improve cognitive functions and the declining quality of life in the elderly.

Carbon monoxide (CO) is a gas endogenously produced in humans, reported to exhibit anti-inflammatory and cytoprotective effects at low concentration. In this context, CO releasing molecules (CORMs) are attracting enormous interest. Herein, we report a series of small-molecule hybrids consisting of a carbonic anhydrase (CA; EC 4.2.1.1) inhibitor linked to a CORM tail section (CAI−CORMs). All compounds were screened in vitro for their inhibition activity against the human (h) CA I, II, IV, IX, and XII isoforms. On selected CAI−CORM hybrids, the CO releasing properties were evaluated, along with their pain-relieving effect, in a model of rheumatoid arthritis. One CAI− CORM hybrid (5b) induced a higher pain-relieving effect compared to the one exerted by the single administration of CAI (5a) and CORM (15b) fragments, shedding light on the possibility to enhance the pain relief effect of CA inhibitors inserting a CO releasing moiety on the same molecular scaffold.

Recently, studies have focused on the antihyperalgesic activity of the A 3 adenosine receptor (A 3 AR) in several chronic pain models, but the cellular and molecular basis of this effect is still unknown. Here, we investigated the expression and functional effects of A 3 AR on the excitability of small-to medium-sized, capsaicin-sensitive, dorsal root ganglion (DRG) neurons isolated from 3-to 4-week-old rats. Real-time quantitative polymerase chain reaction experiments and immunofluorescence analysis revealed A 3 AR expression in DRG neurons. Patch-clamp experiments demonstrated that 2 distinct A 3 AR agonists, Cl-IB-MECA and the highly selective MRS5980, inhibited Ca 2+ -activated K + (K Ca ) currents evoked by a voltage-ramp protocol. This effect was dependent on a reduction in Ca 2+ influx via N-type voltage-dependent Ca 2+ channels, as Cl-IB-MECA-induced inhibition was sensitive to the N-type blocker PD173212 but not to the L-type blocker, lacidipine. The endogenous agonist adenosine also reduced N-type Ca 2+ currents, and its effect was inhibited by 56% in the presence of A 3 AR antagonist MRS1523, demonstrating that the majority of adenosine's effect is mediated by this receptor subtype. Current-clamp recordings demonstrated that neuronal firing of rat DRG neurons was also significantly reduced by *

We studied the effects of intestinal inflammation on pentylenetetrazole (PTZ)-induced seizures in mice and the effects thereon of some antiepileptic and anti-inflammatory treatments to establish if a link may exist. The agents tested were: alpha-lactoalbumin (ALAC), a whey protein rich in tryptophan, effective in some animal models of epilepsy and on colon/intestine inflammation, valproic acid (VPA), an effective antiepileptic drug in this seizure model, mesalazine (MSZ) an effective aminosalicylate anti-inflammatory treatment against ulcerative colitis and sodium butyrate (NaB), a short chain fatty acid (SCFA) normally produced in the intestine by gut microbiota, important in maintaining gut health and reducing gut inflammation and oxidative stress. Intestinal inflammation was induced by dextran sulfate sodium (DSS) administration for 6 days. Drug treatment was started on day 3 and lasted 11 days, when seizure susceptibility to PTZ was measured along with intestinal inflammatory markers (i.e. NF-κB, Iκ-Bα, COX-2, iNOS), histological damage, disease activity index (DAI) and SCFA concentration in stools. DSS-induced colitis increased seizure susceptibility and while all treatments were able to reduce intestinal inflammation, only ALAC and NaB exhibited significant antiepileptic properties in mice with induced colitis, while they were ineffective as antiepileptics at the same doses in control mice without colitis. Interestingly, in DSS-treated mice, VPA lost part of its antiepileptic efficacy in comparison to preventing seizures in non-DSS-treated mice while MSZ remained ineffective in both groups. Our study demonstrates that reducing intestinal inflammation through ALAC or NaB administration has specific anticonvulsant effects in PTZ-treated mice. Furthermore, it appears that intestinal inflammation may reduce the antiepileptic effects of VPA, although we confirm that it decreases seizure threshold in this group. Therefore, we suggest that intestinal inflammation may represent a valid antiepileptic target which should also be considered as a participating factor to seizure incidence in susceptible patients and also could be relevant in reducing standard antiepileptic drug efficacy.

Background and Purpose Hydrogen sulfide (H2S)‐releasing agents are viewed as potential antihypertensive drugs. Recently, natural isothiocyanates emerged as original H2S‐donor agents. Among them, erucin, present in some edible cruciferous plants, shows suitable H2S‐releasing properties and features of “druggability.” The aim of this work was to investigate the erucin‐mediated release of H2S inside vascular cells, its vasorelaxing effects, and activity on BP of normo and hypertensive animals. Experimental Approach Intracellular H2S‐release and the hyperpolarizing effect of erucin were tested using fluorescent dye, in human aortic smooth muscle cells (HASMCs). Its direct vasorelaxing effect and ability to inhibit noradrenaline‐induced vasoconstriction were evaluated on endothelium‐intact or ‐denuded rat aortic rings. Its vasodilator properties were tested in coronary arteries using Langendorff‐perfused rat hearts. Finally, erucin's antihypertensive activity was evaluated in vivo in normotensive and spontaneously hypertensive rats (SHRs) by recording systolic BP using the tail‐cuff method. Key Results Erucin induced the release of H2S inside HASMCs. Moreover, erucin hyperpolarized the membrane of HASMCs membrane in a concentration‐dependent manner. It induced vasodilatation of rat aortic rings, in endothelium‐denuded vessels. This effect was further improved by the presence of endothelial NO. When pre‐incubated with rat aortic rings, erucin induced concentration‐dependent inhibition of noradrenaline‐induced vasoconstriction. Erucin did not affect basal coronary flow but restored the flow to normal in pre‐contracted coronary vessels. Finally, in vivo, erucin decreased systolic BP in SHRs by about 25%, and restored the BP to values observed in normotensive rats. Conclusions and Implications Erucin is an H2S donor endowed with vasorelaxing and antihypertensive effects. Linked Articles This article is part of a themed section on Hydrogen Sulfide in Biology & Medicine. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.4/issuetoc