Acrylamide aggravates cognitive deficits at night period via the gut-brain axis by reprogramming the brain circadian clock

Neurotoxicity of hexaconazole on rat brain: The aspect of biological rhythm

Hexaconazole is a widely used and frequently detected fungicide which is also reported to be persistent in environment. The toxicity of Hex to non-organisms such as reproductive toxicity, endocrine disrupting toxicity, and carcinogenic toxicity had been reported. However, study on the Hex-induced neurotoxicity is rare and the mechanism is still unclear. Therefore, in this study, environmental related concentrations of Hex were chosen to investigate the effects of Hex on nervous system from the aspect of biological rhythm under 90 d sub-chronic exposure. The results showed that Hex significantly affected the cognitive function of rats resulting in the deterioration of learning and memory ability and induced oxidative stress in rat brain. Moreover, the notable changes of neurotransmitters in rat brain suggested the disorder of nerve signaling conduction induced by Hex. The influence of Hex on biological rhythm was further detected which showed that levels of rhythm regulatory genes and proteins significantly disturbed at four monitored time periods. Based on these results, it was supposed that the underlying mechanism of Hex-induced cognitive dysfunction might through oxidative stress pathway. Our findings could systematically and comprehensively clarify the effects of Hex on nervous system and were helpful for prevention neurological diseases induced by triazole pesticides.

Moniezia benedeni drives the SNAP-25 expression of the enteric nerves in sheep's small intestine

BACKGROUND

The neuroimmune network plays a crucial role in regulating mucosal immune homeostasis within the digestive tract. Synaptosome-associated protein 25 (SNAP-25) is a presynaptic membrane-binding protein that activates ILC2s, initiating the host's anti-parasitic immune response.

METHODS

To investigate the effect of Moniezia benedeni (M. benedeni) infection on the distribution of SNAP-25 in the sheep's small intestine, the recombinant plasmid pET-28a-SNAP-25 was constructed and expressed in BL21, yielding the recombinant protein. Then, the rabbit anti-sheep SNAP-25 polyclonal antibody was prepared and immunofluorescence staining was performed with it. The expression levels of SNAP-25 in the intestines of normal and M. benedeni-infected sheep were detected by ELISA.

RESULTS

The results showed that the SNAP-25 recombinant protein was 29.3 KDa, the titer of the prepared immune serum reached 1:128,000. It was demonstrated that the rabbit anti-sheep SNAP-25 polyclonal antibody could bind to the natural protein of sheep SNAP-25 specifically. The expression levels of SNAP-25 in the sheep's small intestine revealed its primary presence in the muscular layer and lamina propria, particularly around nerve fibers surrounding the intestinal glands. Average expression levels in the duodenum, jejunum, and ileum were 130.32 pg/mg, 185.71 pg/mg, and 172.68 pg/mg, respectively. Under conditions of M. benedeni infection, the spatial distribution of SNAP-25-expressing nerve fibers remained consistent, but its expression level in each intestine segment was increased significantly (P < 0.05), up to 262.02 pg/mg, 276.84 pg/mg, and 326.65 pg/mg in the duodenum, jejunum, and ileum, and it was increased by 101.06%, 49.07%, and 89.16% respectively.

CONCLUSIONS

These findings suggest that M. benedeni could induce the SNAP-25 expression levels in sheep's intestinal nerves significantly. The results lay a foundation for further exploration of the molecular mechanism by which the gastrointestinal nerve-mucosal immune network perceives parasites in sheep.

Dietary acrylamide disrupts the functioning of the biological clock

Acrylamide (ACR) is a known carcinogen and neurotoxin. It is chronically consumed in carbohydrate-rich snacks processed at high temperatures. This calls for systematic research into the effects of ACR intake, best performed in an experimental model capable of detecting symptoms of its neurotoxicity at both high and low doses. Here, we study the influence of 10 µg/g (corresponding to the concentrations found in food products) and, for comparison, 60, 80 and 110 µg/g dietary ACR, on the fruit fly Drosophila melanogaster. We show that chronic administration of ACR affects lifespan, activity level and, most importantly, the daily and circadian pattern of locomotor activity of Drosophila. ACR-treated flies show well-defined and concentration-dependent symptoms of ACR neurotoxicity; a reduced anticipation of upcoming changes in light conditions and increased arrhythmicity in constant darkness. The results suggest that the rhythm-generating neural circuits of their circadian oscillator (biological clock) are sensitive to ACR even at low concentrations if the exposure time is sufficiently long. This makes the behavioural readout of the clock, the rhythm of locomotor activity, a useful tool for studying the adverse effects of ACR and probably other compounds.

Assessing the Influence of Intermittent Alcohol Access on Acrylamide-Induced Neuronal Toxicity in an Experimental Rat Model

Tobacco and alcohol have been identified as health risk behaviors associated with significant unfavorable health consequences, ranking within the list of the top ten causes of mortality and disability-adjusted life years (DALY). The combustion of tobacco leads to the formation of acrylamide (ACR), which is well known for its neurotoxic effects. Similarly, alcohol consumption has also been widely recognized for its neurotoxic effects. Both substances can affect neurons and neuroglia cells through various pathways. This study sought to examine the impacts of co-administration of ACR and intermittent-access ethanol (IAE) consumption over a period of one month. The experimental group received 20 mg/kg of ACR, administered orally, along with IAE of 20% ethanol sessions lasting 24 h, three times per week. The cognitive outcomes were assessed utilizing the elevated plus maze (EPM), which was employed as a means of assessing the capability to learn and remember, the novel object recognition (NOR) test, which was employed to assess recognition memory, and the Y-maze, which was used to explore a new environment and navigate. Additionally, ELISA assays were performed to examine underlying mechanisms, including markers associated with inflammation (NF-κB, PGE2, and TNF-α), apoptosis (Bcl2, Bax, and Caspase-3), and oxidative stress (MDA, catalase, and GSH). These markers were assessed in the brain homogenate as part of the investigation. Furthermore, a histopathological study was conducted. The findings indicated that NF-κB levels increased significantly in the combination of ACR and IAE groups (ACR + IAE) compared to either the ACR-alone or IAE-alone groups. However, parallel changes were observed in TNF-α, PGE2, Bax, Bcl-2, Caspase-3, GSH, and CAT levels when comparing the ACR + IAE group to the ACR-alone group. Comparable alterations were noted between the ACR + IAE treatment and IAE-alone groups in TNF-α, Bcl-2, MDA, GSH, and CAT levels. Moreover, the histopathological analysis revealed significant changes between the ACR + IAE and the ACR- or IAE-alone groups. Regarding memory parameters assessed using tests including EPM, NOR, and Y-maze, considerable changes were observed across all treatment groups as opposed to the control. Surprisingly, there were no notable differences in the NOR and Y-maze tasks between the alone and combination treatment. Further study is necessary to explore the long-term alteration of co-administering ACR and IAE on behavior, memory, and neurotoxicity-related mechanisms, in order to elucidate their combined effects more clearly.

Long-term intake of thermo-induced oxidized oil results in anxiety-like and depression-like behaviors: involvement of microglia and astrocytes

Frequent consumption of fried foods has been strongly associated with a higher risk of anxiety and depression, particularly among young individuals. The existing evidence has indicated that acrylamide produced from starchy foods at high temperatures can induce anxious behavior. However, there is limited research on the nerve damage caused by thermo-induced oxidized oil (TIOO). In this study, we conducted behavioral tests on mice and found that prolonged consumption of TIOO led to significant anxiety behavior and a tendency toward depression. TIOO primarily induced these two emotional disorders by affecting the differentiation of microglia, the level of inflammatory factors, the activation of astrocytes, and glutamate circulation in brain tissue. By promoting the over-differentiation of microglia into M1 microglia, TIOO disrupted their differentiation balance, resulting in an up-regulation of inflammatory factors (IL-1β, IL-6, TNF-α, NOS2) in M1 microglia and a down-regulation of neuroprotective factors IL-4/IL-10 in M2 microglia, leading to nerve damage. Moreover, TIOO activated astrocytes, accelerating their proliferation and causing GFAP precipitation, which damaged astrocytes. Meanwhile, TIOO stimulates the secretion of the BDNF and reduces the level of the glutamate receptor GLT-1 in astrocytes, leading to a disorder in the glutamate-glutamine cycle, further exacerbating nerve damage. In conclusion, this study suggests that long-term intake of thermo-induced oxidized oil can trigger symptoms of anxiety and depression.

Dietary lipoic acid alleviates autism-like behavior induced by acrylamide in adolescent mice: the potential involvement of the gut-brain axis

Consuming fried foods has been associated with an increased susceptibility to mental health disorders. Nevertheless, the impact of alpha-lipoic acid (α-LA, LA) on fried food-induced autism-like behavior remains unclear. This study aimed to explore how LA affects autism-related behavior and cognitive deficits caused by acrylamide in mice, a representative food hazard found in fried foods. This improvement was accomplished by enhanced synaptic plasticity, increased neurotrophin expression, elevated calcium-binding protein D28k, and restored serotonin. Additionally, LA substantially influenced the abundance of bacteria linked to autism and depression, simultaneously boosted short-chain fatty acid (SCFA) levels in fecal samples, and induced changes in serum amino acid concentrations. In summary, these findings suggested that exposure to acrylamide in adolescent mice could induce the development of social disorders in adulthood. LA showed promise as a nutritional intervention strategy to tackle emotional disorders during adolescence.

Acrylamide induces neurotoxicity in zebrafish (Danio rerio) via NLRP3-mediated pyroptosis

Acrylamide (ACR) is widely used in water treatment, cosmetics, dyes, paper manufacturing, and other industries. Evidence suggests that ACR exposure causes selective neurotoxicity in humans. The primary symptoms include extremity numbness, skeletal muscle weakness, and ataxia, skeletal muscle weakness. An experimental zebrafish (Danio rerio) embryo model was used in this study to assess the impact of ACR toxicity on the development of the zebrafish nervous system. The results showed that neurodevelopmental disorders, inflammatory reactions, and oxidative stress were common in zebrafish exposed to ACR. Furthermore, ACR exposure induces pyroptotic phenotypical nerve cells, pyroptosis-related protein activation, and inflammasome NLR family pyrin domain-containing 3 (NLRP3) expression. Caspy and Caspy2 expression was knocked down via CRISPR/Cas9 to further investigate the pyroptotic mechanism, showing that these two targets alleviated the inflammatory reaction and neurodevelopmental disorder caused by ACR. Moreover, the Caspy-mediated classic pathway may be vital for the pyroptosis caused by ACR. In conclusion, this study is the first to show that ACR can activate NLRP3 inflammation to cause neurotoxicity in zebrafish via the Caspy pathways, which differs from the traditional exogenous infection model.

Chronotoxicity of Acrylamide in Mice Fed a High-Fat Diet: The Involvement of Liver CYP2E1 Upregulation and Gut Leakage

Acrylamide (ACR) is produced under high-temperature cooking of carbohydrate-rich foods via the Maillard reaction. It has been reported that ACR has hepatic toxicity and can induce liver circadian disorder. A high fat diet (HFD) could dysregulate liver detoxification. The current study showed that administration of ACR (100 mg/kg) reduced the survival rate in HFD-fed mice, which was more pronounced when treated during the night phase than during the day phase. Furthermore, ACR (25 mg/kg) treatment could cause chronotoxicity in mice fed a high-fat diet, manifested as more severe mitochondrial damage of liver during the night phase than during the day phase. Interestingly, HFD induced a higher CYP2E1 expressions for those treated during the night phase, leading to more severe DNA damage. Meanwhile, the expression of gut tight junction proteins also significantly decreases at night phase, leading to the leakage of LPSs and exacerbating the inflammatory response at night phase. These results indicated that a HFD could induce the chronotoxicity of ACR in mice liver, which may be associated with increases in CYP2E1 expression in the liver and gut leak during the night phase.

Chronic acrylamide exposure resulted in dopaminergic neuron loss, neuroinflammation and motor impairment in rats

Acrylamide (ACR) as a by-product of Maillard reaction is widely present in food. Although ACR is known to exhibit neurotoxicity, most studies about ACR neurotoxicity are currently short-term high-dose providing limited reference value for human exposure. The present study aims to determine the effects of chronic ACR exposure on dopaminergic neurons in rat nigra and the potential mechanism from the perspective of NLRP3 inflammasome-mediated neuroinflammation. The SD rats were maintained on treated drinking water providing dosages of 0, 0.5, or 5 mg/kg/day ACR for 12 months. ACR exposure caused motor dysfunction in rats, which was associated with dopaminergic neuron loss, α-Synuclein (α-Syn) accumulation and decreased brain-derived neurotrophic factor (BDNF) in nigra. ACR activated microglia by increasing Iba-1⁺, Iba-1⁺CD68⁺ positive cells and the percentage of ameboid-shaped ones in rat nigra. ACR markedly upregulated the protein levels of NLRP3 inflammasome constituents NLRP3 and caspase-1 and inflammatory cytokine IL-1β. ACR chronic exposure increased the risk of Parkinson's disease (PD) like dopaminergic neuron depletion in nigra potentially through NLRP3 inflammasome-mediated neuroinflammtion.

Acrylamide inhibits long-term potentiation and learning involving microglia and pro-inflammatory signaling

Acrylamide is a chemical used in various industries and a product following high-temperature cooking of vegetables containing asparagine. Environmental or dietary exposure to acrylamide could impair cognitive function because of its neurotoxicity. Using rat hippocampal slices, we tested whether acrylamide alters induction of long-term potentiation (LTP), a cellular model of learning and memory. We hypothesized that acrylamide impairs cognitive function via activation of pro-inflammatory cytokines because robust upregulation of NLRP3 inflammasome has been reported. Although acrylamide up to 3 mM did not alter basal synaptic transmission, incubation with 10 μM or acute administration of 100 μM acrylamide inhibited induction of LTP. Inhibitors of toll-like receptor 4 (TLR4), and minocycline, an inhibitor of microglial activation, overcame the effects of acrylamide on LTP induction. Furthermore, we observed that acrylamide failed to inhibit LTP after administration of MCC950, an inhibitor of NLRP3, or in the presence of Interleukin-1 receptor antagonist (IL-1Ra). We also found that in vivo acrylamide injection transiently impaired body weight gain and impaired one-trial inhibitory avoidance learning. This learning deficit was overcome by MCC950. These results indicate that cognitive impairment by acrylamide is mediated by mechanisms involving microglia and release of cytokines via NLRP3 activation.

The involvement of oxidative stress, neuronal lesions, neurotransmission impairment, and neuroinflammation in acrylamide-induced neurotoxicity in C57/BL6 mice

Acrylamide (ACR) is a typical environmental contaminant, presenting potential health hazards that have been attracting increasing attention. Its neurotoxicity is known to cause significant damage to health. However, the mechanisms of ACR-induced neurotoxicity require further clarification. This study uses a mouse model to explore how ACR-induced oxidative stress, neuronal lesions, neurotransmission impairment, and neuroinflammation mutually contribute to neurotoxicity. A distinct increase in the cellular reactive oxygen species (ROS) levels, malondialdehyde (MDA), and 8-hydroxy-2-deoxyguanosine (8-OHdG) content and a significant decrease in the glutathione (GSH) content after ACR exposure were indicative of oxidative stress. Moreover, ACR caused neurological defects associated with gait abnormality and neuronal loss while suppressing the acetylcholine (ACh) and dopamine (DA) levels and increasing the protein expression of α-synuclein (α-syn), further inhibiting cholinergic and dopaminergic neuronal function. Additionally, ACR treatment caused an inflammatory response via nuclear factor-kappa B (NF-κB) activation and increased the protein expression of NOD-like receptor protein-3 (NLRP3), consequently activating the NLRP3 inflammasome constituents, including cysteinyl aspartate specific proteinase 1 (Caspase-1), apoptosis-associated speck-like protein containing CARD (ASC), N domain gasdermin D (N-GSDMD), interleukin-1β (IL-1β), and IL-18. The results revealed the underlying molecular mechanism of ACR-induced neurotoxicity via oxidative stress, neurotransmission impairment, and neuroinflammation-related signal cascade. This information will further improve the development of an alternative pathway strategy for investigating the risk posed by ACR. The hypothetical mechanism of ACR-induced neurotoxicity in vivo.

The Mechanism of Acrylamide-Induced Neurotoxicity: Current Status and Future Perspectives

Acrylamide (ACR), a potential neurotoxin, is produced by the Maillard reaction between reducing sugars and free amino acids during food processing. Over the past decade, the neurotoxicity of ACR has caused increasing concern, prompting many related studies. This review summarized the relevant literature published in recent years and discussed the exposure to occupational, environmental, and daily ACR contamination in food. Moreover, ACR metabolism and the potential mechanism of ACR-induced neurotoxicity were discussed, with particular focus on the axonal degeneration of the nervous system, nerve cell apoptosis, oxidative stress, inflammatory response, and gut-brain axis homeostasis. Additionally, the limitations of existing knowledge, as well as new perspectives, were examined, specifically regarding the connection between the neurotoxicity caused by ACR and neurodegenerative diseases, NOD-like receptor protein 3 (NLRP3) inflammasome-related neuroinflammation, and microbiota-gut-brain axis signaling. This review might provide systematic information for developing an alternative pathway approach to assess ACR risk.

Tea combats circadian rhythm disorder syndrome via the gut-liver-brain axis: potential mechanisms speculated

Circadian rhythm is an intrinsic mechanism developed by organisms to adapt to external environmental signals. Nowadays, owing to the job and after-work entertainment, staying up late - Circadian rhythm disorders (CRD) are common. CRD is linked to the development of fatty liver, type 2 diabetes, and chronic gastroenteritis, which affecting the body's metabolic and inflammatory responses via multi-organ crosstalk (gut-liver-brain axis, etc.). However, studies on the mechanisms of multi-organ interactions by CRD are still weak. Current studies on therapeutic agents for CRD remain inadequate, and phytochemicals have been shown to alleviate CRD-induced syndromes that may be used for CRD-therapy in the future. Tea, a popular phytochemical-rich beverage, reduces glucolipid metabolism and inflammation. But it is immature and unclear in the mechanisms of alleviation of CRD-mediated syndrome. Here, we have analyzed the threat of CRD to hosts and their offspring' health from the perspective of the "gut-liver-brain" axis. The potential mechanisms of tea in alleviating CRD were further explored. It might be by interfering with bile acid metabolism, tryptophan metabolism, and G protein-coupled receptors, with FXR, AHR, and GPCR as potential targets. We hope to provide new perspectives on the role of tea in the prevention and mitigation of CRD.HighlightsThe review highlights the health challenges of CRD via the gut-liver-brain axis.CRD research should focus on the health effects on healthy models and its offspring.Tea may prevent CRD by regulating bile acid, tryptophan, and GPCR.Potential targets for tea prevention and mitigation of CRD include FXR, AHR and GPCR.A comprehensive assessment mechanism for tea in improving CRD should be established.

Effects of quercetin on tenderness, apoptotic and autophagy signalling in chickens during post-mortem ageing

The effect of quercetin on chicken breast muscle tenderness and the associated mechanism were investigated. The results indicated that quercetin significantly decreased the shear force and increased the myofibril fragmentation index (MFI). Haematoxylin-eosin-stained images showed that the internal structure of myofibril bundles in the quercetin-treated group was obviously degraded. Transmission electron microscopy showed that the myofibril structure, especially the M-line and A-band, was seriously degraded after quercetin treatment. Furthermore, quercetin treatment increased caspase-3 activity and the Bax/Bcl-2 ratio. The intensity of BiP, XBP1 and p-IRE1/IRE1 ratio increased significantly, and caspase-12 was activated. In addition, quercetin induced the transition from LC3I to LC3II and increased the expression of ATG7 and Beclin-1. The PI3K/Akt/mTOR signalling pathway was involved in the induction of autophagy and apoptosis by quercetin. These results indicated quercetin can promote meat tenderization, and activate apoptosis and autophagy pathways during post-mortem ageing.

Procyanidin A1 and its digestive products prevent acrylamide-induced intestinal barrier dysfunction via the MAPK-mediated MLCK pathway

Procyanidins can alleviate small-intestine damage induced by acrylamide (ACR). However, little is known about whether procyanidins, after gastrointestinal digestion, can prevent ACR-induced intestinal barrier damage and the possible mechanism. Here, Caco-2 cells were differentiated into an intestinal epithelial cell monolayer membrane, which was stimulated with or without ACR in the presence or absence of procyanidin A₁ (A₁) and its digestive products (D-A₁). Our findings show that both A₁ and D-A₁ significantly increased the transepithelial electrical resistance (TEER) value; decreased FITC-dextran 4 kDa (FITC-4 kDa) permeability, apoptosis and lactic dehydrogenase (LDH) release; and enhanced the expression of claudin-1, occludin and zonula occludens-1 (ZO-1) in ACR-induced Caco-2 cell monolayer membrane. In addition, A₁ and D-A₁ suppressed ACR-induced phosphorylation of mitogen-activated protein kinase (MAPK). Finally, A₁ and D-A₁ inhibited the myosin light chain kinase (MLCK) signaling pathway, thereby maintaining normal intestinal barrier functions, similar to the MLCK inhibitor in ACR-induced Caco-2 cell monolayer membrane. These findings indicate that A₁ can alleviate ACR-induced intestinal barrier dysfunction via inhibiting the MAPK/MLCK signaling pathway, and it still has excellent inhibitory effects after digestion.

Blumea laciniata protected Hep G2 cells and Caenorhabditis elegans against acrylamide-induced toxicity via insulin/IGF-1 signaling pathway

Acrylamide (AC), a proved toxin is mainly used in industrial fields and proved to possess various toxicities. In recent years, AC has been found in starch-containing foods due to Maillard reaction in a high-temperature process. Therefore, how to mitigate the toxic effect of AC is a research spot. Blumea laciniata is a widely used folk medicine in Asia and the extract from B. laciniata (EBL) exhibited a strong protection on cells against oxidative stress. In this work, we used EBL to protect Hep G2 cells and Caenorhabditis elegans against AC toxicity. As the results turned out, EBL increased cell viability under AC stress and notably reduced the cell apoptosis through decreasing the high level of ROS. Moreover, EBL extended the survival time of C. elegans, while EBL failed to prolong the survival time of mutants that were in Insulin signaling pathway. Besides, the expressions of antioxidant enzymes were activated after the worms were treated with EBL and daf-16 gene was activated. Our results indicated that EBL exhibited a protective effect against AC induced toxicity in Hep G2 cells and C. elegans via Insulin/IGF-1 signaling pathway. These outcomes may provide a promising natural drug to alleviate the toxic effect of AC.

Acrylamide induces intrinsic apoptosis and inhibits protective autophagy via the ROS mediated mitochondrial dysfunction pathway in U87-MG cells

Acrylamide (ACR) is a potential neurotoxin commonly found in the environment, as well as in food repeatedly exposed heat processing, but the mechanism underpinning ACR-induced neurotoxicity remains unclear. This study investigated the potential association and underlying signal transduction of oxidative stress, apoptosis, and autophagy associated with ACR-triggered neurotoxicity. Therefore, U87-MG cells were treated with varying ACR concentrations, while the cell activity reduction depended on the specific dosage and time parameters. Biochemical analyses showed that ACR significantly increased the reactive oxygen species (ROS), malondialdehyde (MDA), and Ca²⁺ levels while decreasing the glutathione (GSH) levels and mitochondrial membrane potential (ΔΨm), finally leading to a higher cell apoptotic rate. Moreover, ACR induced U87-MG cell apoptosis and autophagy via ROS-triggered expression in the mitochondrial apoptosis pathway, NF-κB activation, and autophagosome accumulation. In addition, the autophagosome accumulation induced by ACR could probably be ascribed to blocked autophagic flux, inhibiting the autophagosomes from combining with lysosomes, while the inhibition of autophagy caused by ACR further promoted the initiation of apoptosis. In conclusion, the results indicated that the apoptotic and autophagic pathways responded to ACR-induced neurotoxicity. However, inhibited protective autophagy further promoted apoptotic progression. New insights may be derived from these cellular responses that can help develop diverse pathway strategies for assessing the risk posed by ACR.HIGHLIGHTSACR induced mitochondrial- and caspase-dependent apoptosis in U87-MG cells.ACR regulated the autophagic markers and blocked autophagic flux in U87-MG cells.ACR inhibited protective autophagy and promoted apoptotic initiation in U87-MG cells.

Effect of long-term exposure to acrylamide on endoplasmic reticulum stress and autophagy in rat cerebellum

Acrylamide (ACR) is a widely used chemical compound that has neurotoxicity in human, but whether ACR could impair the cerebellum and the related mechanism were still unknown. This study aimed to observe the changes in behavioral performance and cerebellar morphology caused by chronic ACR exposure, and to evaluate its influence on apoptosis, endoplasmic reticulum stress (ERS) and autophagy. Rats were treated with 0, 0.5 and 5 mg/kg ACR by drinking water for 12 months. Results showed that 5 mg/kg ACR treatment damaged the gait, balance ability, hindlimb muscle strength and motor coordination ability of rats. The results of hematoxylin and eosin and Nissl staining indicated that ACR impaired the structures of all three layers of the cerebellum, especially the Purkinje cell layer, showing abnormal morphology with nucleus condensation and pyknosis. Accumulation of autophagosomes, dilated endoplasmic reticulum and swollen mitochondria were observed in neurons under transmission electron microscopy. The enhanced apoptotic rates and the increased Bax expression indicated the elevated level of apoptosis. The results of Western blot showed that ACR treatment elevated protein levels of Beclin1, LC3-II/LC3-I, p-PERK/t-PERK, ATF4 and CHOP, indicating the initiation of autophagy, the activation of PERK pathway in ERS. This work helps to demonstrate the ACR neurotoxicity on cerebellum under chronic treatment and its underlying mechanism.

Development of astaxanthin-loaded layer-by-layer emulsions: physicochemical properties and improvement of LPS-induced neuroinflammation in mice

Astaxanthin (AST) has been shown to have neuroprotective effects; however, its bioavailability in vivo is low due to its hydrophobic properties. In this study, lactoferrin (LF) was prepared by heat-treatment at different temperatures, and on this basis, a layer-by-layer self-assembly method was used to construct double-layer emulsions with LF as the inner layer and polysaccharide (beet pectin, BP or carboxymethyl chitosan, CMCS) as the outer layer. Then AST was encapsulated in the emulsions and their physiochemical properties and function were investigated. The results indicated that high temperature heated LF (95 °C) showed a more stable structure than the lower temperature one, and the exposed internal nonpolar groups of LF could give the emulsion an enhanced stability. The rheology results showed that compared with CMCS, the double-layer emulsion formed by BP had a higher viscosity. In addition, the 95 °C LF-AST-BP emulsion showed the best stability among all the bilayer emulsions. The best emulsion was then used as a model drug to investigate its effects on lipopolysaccharide (LPS)-induced neuroinflammation and learning-memory loss in C57BL/6J mice. Through animal behavioral experiments, it was found that dietary supplementation with the AST emulsion could effectively improve the brain cognitive and learning memory impairment caused by inflammation. Transmission electron microscopy, mRNA and western blotting results also illustrated that the AST emulsion could alleviate neuroinflammation caused by LPS. This study provides a feasible scheme for exploring an AST loaded system and may be suitable for food and drug applications.

A fluorescence biosensor based on single-stranded DNA and carbon quantum dots for acrylamide detection

As a potential carcinogen produced in food thermal processing, acrylamide (AM) can cause irreversible harm to human health. For the detection of AM in food products, a simple fluorescent biosensor based on single-stranded DNA (ssDNA) and carbon quantum dots (CQDs) was developed. Reduced fluorescence intensity of CQDs at 445 nm (excitation at 350 nm) was induced by the attachment of ssDNA. In the presence of AM, ssDNA was preferentially bound to AM by hydrogen bonding and the degree of fluorescence reduction was smaller than that without AM. Under optimized conditions, results showed that the sensing approach for detecting AM had a low detection limit of 2.41 × 10^-8 M in the standard solution, and a linear relationship ranging from 5 × 10^-3 to 1 × 10^-7 M with the determination coefficient (R²) of 0.9895 was obtained. Furthermore, a good recovery percentage (91.36-98.11%) in bread crust showed the potential for practical applications of this proposed biosensor.

Rheostatic Balance of Circadian Rhythm and Autophagy in Metabolism and Disease

Circadian rhythms are physical, behavioral and environmental cycles that respond primarily to light and dark, with a period of time of approximately 24 h. The most essential physiological functions of mammals are manifested in circadian rhythm patterns, including the sleep-wake cycle and nutrient and energy metabolism. Autophagy is a conserved biological process contributing to nutrient and cellular homeostasis. The factors affecting autophagy are numerous, such as diet, drugs, and aging. Recent studies have indicated that autophagy is activated rhythmically in a clock-dependent manner whether the organism is healthy or has certain diseases. In addition, autophagy can affect circadian rhythm by degrading circadian proteins. This review discusses the interaction and mechanisms between autophagy and circadian rhythm. Moreover, we introduce the molecules influencing both autophagy and circadian rhythm. We then discuss the drugs affecting the circadian rhythm of autophagy. Finally, we present the role of rhythmic autophagy in nutrient and energy metabolism and its significance in physiology and metabolic disease.

Notoginsenoside R1 Protects Against the Acrylamide-Induced Neurotoxicity via Upregulating Trx-1-Mediated ITGAV Expression: Involvement of Autophagy

Acrylamide (ACR) is a common chemical used in various industries and it said to have chronic neurotoxic effects. It is produced during tobacco smoking and is also generated in high-starch foods during heat processing. Notoginsenoside R1 (NR1) is a traditional Chinese medicine, which is used to improve the blood circulation and clotting. The objective of this study was to investigate the mechanism of ACR-triggered neurotoxicity and to identify the protective role of NR1 by upregulating thioredoxin-1 (Trx-1). Our results have shown that NR1 could block the spatial and cognitive impairment caused by ACR administration. Bioinformatics analysis revealed that Trx-1 regulated autophagy via Integrin alpha V (ITGAV). NR1 could resist the ACR-induced neurotoxicity by upregulating thioredoxin-1 in PC12 cells and mice. The autophagy-related proteins like autophagy-related gene (ATG) 4B, Cathepsin D, LC3 II, lysosomal-associated membrane protein 2a (LAMP2a), and ITGAV were restored to normal levels by NR1 treatment in both PC12 cells and mice. Besides, we also found that overexpression of Trx-1 resisted ACR-induced autophagy in PC12 cells and downregulation of Trx-1 triggered autophagy induced by ACR in PC12 cells. Therefore, it could be concluded that Trx-1 was involved in the autophagy pathway. Besides, we also found that ITGAV was an intermediate node linking Trx-1 and the autophagy pathway.

Acrylamide impairs ovarian function by promoting apoptosis and affecting reproductive hormone release, steroidogenesis and autophagy-related genes: An in vivo study

Acrylamide (ACR) toxicity is quite common due to its widespread use in industry and due to the Maillard browning reaction that occurs in foods containing high concentrations of hydrocarbons subjected to high temperatures. This study aimed to elucidate the female reproductive toxicity of ACR in vivo. Fifty-day-old Wistar-Albino female rats were treated with different dosages of ACR (2.5, 10, and 50 mg/kg/day). After treatment, the animals were sacrificed, and serum and ovary samples were collected for histological examination, hormone analysis, TUNEL analysis, and RT-PCR studies. We found that ACR acts by significantly reducing ovarian weight and serum progesterone and estradiol concentrations. In addition, ACR treatment led to pyknotic, heterochromatic characteristics and nuclear fragmentation, as evidenced by hematoxylin staining. The TUNEL assay revealed that granulosa cells were affected after the oral administration of ACR, leading to the apoptosis of follicles at different stages of growth. Compared with the control condition, high doses of ACR (50 mg/kg/day) significantly induced the overexpression of INSL3, CYP17a, IGF1, ESR1, ESR2, ATG5, ATG12 and LC3 in the ovary. Moreover, LC3 mRNA levels significantly increased with increasing doses of ACR (2.5, 10 and 50 mg/kg/day), suggesting that ACR treatment induced autophagy. In conclusion, ACR induced ovarian dysfunction by affecting steroid hormone release, increasing apoptosis and mRNA levels of autophagy-related genes. The eventual correlation between apoptotic granulosa cell death and autophagy needs to be further explored.

Gut microbiota mediates intermittent-fasting alleviation of diabetes-induced cognitive impairment

Cognitive decline is one of the complications of type 2 diabetes (T2D). Intermittent fasting (IF) is a promising dietary intervention for alleviating T2D symptoms, but its protective effect on diabetes-driven cognitive dysfunction remains elusive. Here, we find that a 28-day IF regimen for diabetic mice improves behavioral impairment via a microbiota-metabolites-brain axis: IF enhances mitochondrial biogenesis and energy metabolism gene expression in hippocampus, re-structures the gut microbiota, and improves microbial metabolites that are related to cognitive function. Moreover, strong connections are observed between IF affected genes, microbiota and metabolites, as assessed by integrative modelling. Removing gut microbiota with antibiotics partly abolishes the neuroprotective effects of IF. Administration of 3-indolepropionic acid, serotonin, short chain fatty acids or tauroursodeoxycholic acid shows a similar effect to IF in terms of improving cognitive function. Together, our study purports the microbiota-metabolites-brain axis as a mechanism that can enable therapeutic strategies against metabolism-implicated cognitive pathophysiologies.

Intermittent fasting (IF) has been shown beneficial in reducing metabolic diseases. Here, using a multi-omics approach in a T2D mouse model, the authors report that IF alters the composition of the gut microbiota and improves metabolic phenotypes that correlate with cognitive behavior.

The circadian rhythm in intervertebral disc degeneration: an autophagy connection

There is one circadian clock in the central nervous system and another in the peripheral organs, and the latter is driven by an autoregulatory molecular clock composed of several core clock genes. The height, water content, osmotic pressure and mechanical characteristics of intervertebral discs (IVDs) have been demonstrated to exhibit a circadian rhythm (CR). Recently, a molecular clock has been shown to exist in IVDs, abolition of which can lead to stress in nucleus pulposus cells (NPCs), contributing to intervertebral disc degeneration (IDD). Autophagy is a fundamental cellular process in eukaryotes and is essential for individual cells or organs to respond and adapt to changing environments; it has also been demonstrated to occur in human NPCs. Increasing evidence supports the hypothesis that autophagy is associated with CR. Thus, we review the connection between CR and autophagy and the roles of these mechanisms in IDD.

Resveratrol Maintains Lipid Metabolism Homeostasis via One of the Mechanisms Associated with the Key Circadian Regulator Bmal1

Resveratrol (RES) possesses anti-inflammatory and anti-oxidant activities, and it can prevent liver lipid metabolism disorders in obese and diabetic individuals. This study elucidated the mechanisms of brain and muscle Arnt-like protein-1 (Bmal1) in the protective effects of RES against liver lipid metabolism disorders. The results indicated that RES ameliorated free fatty acid (FFA)-induced (oleic acid (OA): palmitic acid (PA) = 2:1) glycolipid metabolic disorders in hepatocytes. Simultaneously, RES partially reverted the relatively shallow daily oscillations of FFA-induced circadian clock gene transcription and protein expression in HepG2 cells. RES also attenuated FFA-triggered reactive oxygen species (ROS) secretion and restored mitochondrial membrane potential consumption, as well as the restoration of mitochondrial respiratory complex expression. This study provides compelling evidence that RES controls intracellular lipid metabolic imbalance in a Bmal1-dependent manner. Overall, RES may serve as a promising natural nutraceutical for the regulation of lipid metabolic disorders relevant to the circadian clock.

Resveratrol Prevents Acrylamide-Induced Mitochondrial Dysfunction and Inflammatory Responses via Targeting Circadian Regulator Bmal1 and Cry1 in Hepatocytes

Acrylamide, mainly formed in Maillard browning reaction during food processing, causes defects in liver circadian clock and mitochondrial function by inducing oxidative stress. Resveratrol is a polyphenol that has powerful antioxidant and anti-inflammatory activity. However, the preventive effects of resveratrol on acrylamide-triggered oxidative damage and circadian rhythm disorders are unclear at the current stage. The present research revealed that resveratrol pretreatment prevented acrylamide-induced cell death, mitochondrial dysfunction, and inflammatory responses in HepG2 liver cells. Acrylamide significantly triggered disorders of circadian genes transcription and protein expressions including Bmal1 and Cry 1 in primary hepatocytes, which were prevented by resveratrol pretreatment. Moreover, we found that the beneficial effects of resveratrol on stimulating Nrf2/NQO-1 pathway and mitochondrial respiration complex expressions in acrylamide-treated cells were Bmal1-dependent. Similarly, the inhibitory effects of resveratrol on inflammation signaling NF-κB were Cry1-dependent. In conclusion, these results demonstrated resveratrol could be a promising compound in suppressing acrylamide-induced hepatotoxicity and balancing the circadian clock.