Physical impediment to sodium houttuyfonate conversely reinforces ß-glucan exposure stimulated innate immune response to Candida albicans.

Candida albicans is a dimorphic opportunistic pathogen in immunocompromised individuals. We have previously demonstrated that sodium houttuyfonate (SH), a derivative of medicinal herb Houttuynia cordata Thunb, was effective for antifungal purposes. However, the physical impediment of SH by C. albicans ß-glucan may weaken the antifungal activity of SH. In this study, the interactions of SH with cell wall (CW), extracellular matrix (EM), CW ß-glucan, and a commercial ß-glucan zymosan A (ZY) were inspected by XTT assay and total plate count in a standard reference C. albicans SC5314 as well as two clinical fluconazole-resistant strains Z4935 and Z5172. After treatment with SH, the content and exposure of CW ß-glucan, chitin, and mannan were detected, the fungal clearance by phagocytosis of RAW264.7 and THP-1 was examined, and the gene expressions and levels of cytokines TNF-ɑ and IL-10 were also monitored. The results showed that SH could be physically impeded by ß-glucan in CW, EM, and ZY. This impediment subsequently triggered the exposure of CW ß-glucan and chitin with mannan masked in a time-dependent manner. SH-induced ß-glucan exposure could significantly enhance the phagocytosis and inhibit the growth of C. albicans. Meanwhile, the SH-pretreated fungal cells could greatly stimulate the cytokine gene expressions and levels of TNF-ɑ and IL-10 in the macrophages. In sum, the strategy that the instant physical impediment of C. albicans CW to SH, which can induce the exposure of CW ß-glucan may be universal for C. albicans in response to physical deterrent by antifungal drugs.

Effect of traditional Chinese medicine combined group psychotherapy on psychological distress management and gut micro-biome regulation for colorectal cancer survivors: a single-arm phase I clinical trial.

OBJECTIVE: To evaluate the efficacy and feasibility of utilizing Traditional Chinese Medicine (TCM) combined group psychotherapy intervention on psychological distress management and gut micro-biome regulation for colorectal (CRC) survivors. METHODS: A single-arm phase I clinical trial was conducted between December 2020 and December 2021 in Xiyuan Hospital and Beijing Cancer Hospital in China. Inclusion criteria included stage I-III CRC survivors after radical surgery with age between 18 and 75. The intervention was a 6-week online TCM combined group psychotherapy intervention including 90-min communication, TCM lifestyle coaching, self-acupressure guidance, and mindfulness practice led by TCM oncologist and psychiatrist each week. Outcomes were measured by Self-rating Anxiety Scale (SAS), Self-rating Depression Scale (SDS), Fear of Cancer Recurrence Inventor (FCRI), and Quality of Life Questionnaire (QLQ-C30). Fecal samples before and after intervention were collected for 16Sr RNA analysis. RESULTS: We recruited 40 CRC survivors and 38 of them finally completed all interventions with average age of 58±13 years' old. Paired t-test showed that SAS at week 2(35.4±5.8), week 4 (37.9±10.5) and week 6 (31.3±6.4) during the intervention was significantly lower than baseline (42.1±8.3, p<0.05 respectively). SDS score also declined substantially from baseline (38.8±10.7) to week 2 (28.3±8.8, p<0.001) and week 6 (25.4±7.7, p<0.001). FCRI decreased from 19.4±7.2 at baseline to 17.5±7.1 at week 4 (p=0.038) and 16.3±5.8 at week 6 (p=0.008). Although changes of QLQ-C30 were not statistically prominent, symptom burden of insomnia and fatigue significantly alleviated. The abundances of gut microbiota Intestinibacter, Terrisporobacter, Coprobacter, and Gordonibacter were all significantly elevated after intervention. CONCLUSIONS: TCM combined group psychotherapy intervention is feasible and effective to reduce CRC survivors' psychological distress and modulate certain gut bacteria which might be associated with brain-gut axis effect. It is necessary to carry out with phase II randomized controlled clinical trial.

Melatonin Ameliorates Hepatic Ferroptosis in NAFLD by Inhibiting ER Stress via the MT2/cAMP/PKA/IRE1 Signaling Pathway.

Ferroptosis, an iron-dependent cell death form, has recently been observed in the development of non-alcoholic fatty liver disease (NAFLD). Melatonin (Mel) shows potential benefits for preventing and treating liver diseases. Whether and how Mel ameliorates hepatic ferroptosis in NAFLD is not fully understood. Here we established a mouse model of NAFLD induced by long-term high-fat diet (HFD) feeding. We found that Mel treatment ameliorated global metabolic abnormalities and inhibited the progression of NAFLD in mice. Most importantly, Mel supplementation significantly improved HFD-induced iron homeostasis disorders in the liver, including iron overload and ferritin transport disorders. For another, Mel ameliorated HFD-induced hepatic lipid peroxidation. The recuperative role of exogenous Mel on hepatocyte ferroptosis was also observed in PA- or Erastin-treated HepG2 cells. Mechanistically, MT2, but not MT1, was involved in the effect of Mel. Furthermore, Mel treatment inhibited HFD or Erastin-activated ER stress and activated the PKA/IRE1 signaling pathway. Co-expression of p-PKA and p-IRE1 was enhanced by the MT2 antagonist. Inhibitions of PKA and IRE1 respectively improved hepatocyte ferroptosis, and activations of cAMP/PKA reversed Mel's effect on ferroptosis. Collectively, these findings suggest that exogenous Mel inhibits hepatic ferroptosis in NAFLD by ameliorating ER stress through the MT2/cAMP/PKA/IRE1 pathway, proving that Mel is a promising candidate drug for the treatment of hepatic ferroptosis in NAFLD.

Chemodivergent Staudinger Reactions of Secondary Phosphine Oxides and Application to the Total Synthesis of LL-D05139ß Potassium Salt.

Unprecedented Staudinger reaction modes of secondary phosphine oxides (SPO) and organic azides are herein disclosed. By the application of various additives, selective nitrogen atom exclusion from the azide group has been achieved. Chlorotrimethylsilane mediates a stereoretentive Staudinger reaction with a 2-N exclusion which provides a valuable method for the synthesis of phosphinic amides and can be considered complementary to the stereoinvertive Atherton-Todd reaction. Alternatively, a 1-N exclusion pathway is promoted by acetic acid to provide the corresponding diazo compound. The effectiveness of this protocol has been further demonstrated by the total synthesis of the diazo-containing natural product LL-D05139ß, which was prepared as a potassium salt for the first time in 6 steps and 26.5 % overall yield.

Cerium-Encapsulated SbIII-SeIV-Templating Polyoxotungstate for Electrochemically Sensing Human Multidrug Resistance Gene Segment.

A tower-like SbIII-SeIV-templating polyoxotungstate [H2N(CH3)2]12Na7H3[Ce0.5/Na0.5(H2O)5]2[SbSe2W21O75]2·50H2O (1) was synthesized, whose skeleton is assembled from two prolonged lacunary Dawson [SbSe2W21O75]13- units and two [Ce0.5/Na0.5(H2O)5]2+ linkers. The uncommon [SbSe2W21O75]13- unit can be viewed as a combination of one [SeW6O21]2- group grafted onto a trivacant Dawson [SbSeW15O54]11- subunit. The conductive composite 1-Au@rGO containing 1, gold nanoparticles, and reduced graphene oxide (rGO) was conveniently prepared, using which the 1-Au@rGO-based electrochemical genosensor was constructed for detecting human multidrug resistance gene segment. This work enriches structural types of dual-heteroatom-inserted polyoxometalates and promotes the application of polyoxometalates in genosensors.

Eucommia ulmoides polysaccharide modified nano-selenium effectively alleviated DSS-induced colitis through enhancing intestinal mucosal barrier function and antioxidant capacity.

Ulcerative colitis (UC) is currently the most common inflammatory bowel disease (IBD). Due to its diverse and complex causes, there is no cure at present, and researchers are constantly exploring new therapies. In recent years, nano-selenium particle(SeNP) has attracted wide attention due to excellent biological activities. Therefore, in this study, for the first time, we used a natural polysaccharide, Eucommia ulmoides polysaccharide (EUP), modified SeNP to get EUP-SeNP with a size of about 170 nm, and its effect on 3% dextran sulphate sodium (DSS) induced colitis was explored. Our results showed that colon intestinal histology, intestinal mucosal barrier, inflammatory cytokines and intestinal microbiome composition were changed after EUP-SeNP treatment in colitis mice. Specifically, it was also shown that oral treatment of EUP-SeNP could relieve the degree of DSS-induced colitis in mice by restoring weight loss, reducing disease activity index (DAI), enhancing colon antioxidant capacity and regulating intestinal microbiome composition. In addition, we verified the mechanism in intestinal epithelial cell lines, showing that EUP-SeNP inhibited LPS-induced activation of the TRL-4/NF-κB signaling pathway in intestinal epithelial cell lines. To some extend, our study provides therapeutic reference for the treatment of IBD.

Melatonin improves skin barrier damage caused by sleep restriction through gut microbiota.

It is widely known that lack of sleep damages the skin. Therefore, it is necessary to explore the relationship between sleep deprivation and skin damage and to find effective treatments. We established a 28-day sleep restriction (SR) mice model simulating continuous long-term sleep loss. We found that SR would damage the barrier function of mice's skin, cause oxidative stress damage to the skin, weaken the oscillations of the skin's biological clock, and make the circadian rhythm of Bacteroides disappear. The circadian rhythm of short-chain fatty acids (SCFA) receptors in the skin was disordered. After melatonin supplementation, the skin damage caused by SR was improved, the oscillations of the biological clock were enhanced, the circadian rhythm of Bacteroides was restored, and the rhythm of the receptor GPR43 of propionic acid was restored. We speculated that the improving effect of melatonin may be mediated by propionic acid produced by the gut microbiota. We verified in vitro that propionic acid could improve the keratinocytes barrier function of oxidative damage. We then consumed the gut microbiota of mice through antibiotics and found that oral melatonin could not improve skin damage. Moreover, supplementing mice with propionic acid could improve skin damage. Our research showed that lack of sleep impaired skin barrier function. Oral melatonin could improve skin damage by restoring the circadian rhythm of Bacteroides and its propionic acid metabolite.

The Timing Sequence and Mechanism of Aging in Endocrine Organs.

The world is increasingly aging, and there is an urgent need to find a safe and effective way to delay the aging of the body. It is well known that the endocrine glands are one of the most important organs in the context of aging. Failure of the endocrine glands lead to an abnormal hormonal environment, which in turn leads to many age-related diseases. The aging of endocrine glands is closely linked to oxidative stress, cellular autophagy, genetic damage, and hormone secretion. The first endocrine organ to undergo aging is the pineal gland, at around 6 years old. This is followed in order by the hypothalamus, pituitary gland, adrenal glands, gonads, pancreatic islets, and thyroid gland. This paper summarises the endocrine gland aging-related genes and pathways by bioinformatics analysis. In addition, it systematically summarises the changes in the structure and function of aging endocrine glands as well as the mechanisms of aging. This study will advance research in the field of aging and help in the intervention of age-related diseases.

Melatonin improves the homeostasis of mice gut microbiota rhythm caused by sleep restriction.

Insufficient sleep is regarded as a disruptor of circadian rhythm, and it also contributes to the occurrence of intestinal diseases. The physiological functions of the gut depend on the normal circadian rhythm of the intestinal microbiota. However, how lack of sleep affects intestinal circadian homeostasis is unclear. Therefore, we subjected mice to sleep restriction and found that chronic sleep loss disrupts the pattern of colonic microbial communities and reduces the proportion of gut microbiota with a circadian rhythm, with concomitant changes in the peak phase of the KEGG pathway. We then found that exogenous melatonin supplementation restored the proportion of gut microbiota with a circadian rhythm and increased the KEGG pathway with a circadian rhythm. And we screened for possible circadian oscillation families, Muribaculaceae and Lachnospiraceae, that are sensitive to sleep restriction and can be rescued by melatonin. Our results suggest that sleep restriction disrupts the circadian rhythm of the colonic microbiota. In contrast, melatonin ameliorates disturbances in the circadian rhythm homeostasis of the gut microbiota due to sleep restriction.

Gut microbiota-derived metabolites mediate the neuroprotective effect of melatonin in cognitive impairment induced by sleep deprivation.

BACKGROUND: Sleep loss is a serious global health concern. Consequences include memory deficits and gastrointestinal dysfunction. Our previous research showed that melatonin can effectively improve cognitive impairment and intestinal microbiota disturbances caused by sleep deprivation (SD). The present study further explored the mechanism by which exogenous melatonin prevents SD-induced cognitive impairments. Here, we established fecal microbiota transplantation, Aeromonas colonization and LPS or butyrate supplementation tests to evaluate the role of the intestinal microbiota and its metabolites in melatonin in alleviating SD-induced memory impairment.  RESULTS: Transplantation of the SD-gut microbiota into normal mice induced microglia overactivation and neuronal apoptosis in the hippocampus, cognitive decline, and colonic microbiota disorder, manifesting as increased levels of Aeromonas and LPS and decreased levels of Lachnospiraceae_NK4A136 and butyrate. All these events were reversed with the transplantation of SD + melatonin-gut microbiota. Colonization with Aeromonas and the addition of LPS produced an inflammatory response in the hippocampus and spatial memory impairment in mice. These changes were reversed by supplementation with melatonin, accompanied by decreased levels of Aeromonas and LPS. Butyrate administration to sleep-deprived mice restored inflammatory responses and memory impairment. In vitro, LPS supplementation caused an inflammatory response in BV2 cells, which was improved by butyrate supplementation. This ameliorative effect of butyrate was blocked by pretreatment with MCT1 inhibitor and HDAC3 agonist but was mimicked by TLR4 and p-P65 antagonists.  CONCLUSIONS: Gut microbes and their metabolites mediate the ameliorative effects of melatonin on SD-induced cognitive impairment. A feasible mechanism is that melatonin downregulates the levels of Aeromonas and constituent LPS and upregulates the levels of Lachnospiraceae_NK4A136 and butyrate in the colon. These changes lessen the inflammatory response and neuronal apoptosis in the hippocampus through crosstalk between the TLR4/NF-κB and MCT1/ HDAC3 signaling pathways. Video Abstract.

The role of light pollution in mammalian metabolic homeostasis and its potential interventions: A critical review.

Irregular or unnatural artificial light causes severe environmental stress on the survival and health of organisms, which is rapidly becoming a widespread new type of environmental pollution. A series of disruptive behaviors to body homeostasis brought about by light pollution, including metabolic abnormalities, are likely to be the result of circadian rhythm disturbances. Recently, the proposed role of light pollution in metabolic dysregulation has accelerated it into an emerging field. Hence, the regulatory role of light pollution in mammalian metabolic homeostasis is reviewed in this contribution. Light at night is the most widely affected type of light pollution, which disrupts metabolic homeostasis largely due to its disruption of daily food intake patterns, alterations of hormone levels such as melatonin and glucocorticoids, and changes in the rhythm of inflammatory factor production. Besides, light pollution impairs mammalian metabolic processes in an intensity-, photoperiod-, and wavelength-dependent manner, and is also affected by species, gender, and diets. Nevertheless, metabolic disorders triggered by light pollution are not irreversible to some extent. Potential interventions such as melatonin supplementation, recovery to the LD cycle, time-restricted feeding, voluntary exercise, wearing blue light-shied goggles, and bright morning light therapy open a bright avenue to prevent light pollution. This work will help strengthen the relationship between light information and metabolic homeostasis and provide new insights for the better prevention of metabolic disorders and light pollution.

The Role and Mechanism of Essential Selenoproteins for Homeostasis.

Selenium (Se) is one of the essential trace elements that plays a biological role in the body, mainly in the form of selenoproteins. Selenoproteins can be involved in the regulation of oxidative stress, endoplasmic reticulum (ER) stress, antioxidant defense, immune and inflammatory responses and other biological processes, including antioxidant, anti-inflammation, anti-apoptosis, the regulation of immune response and other functions. Over-loading or lack of Se causes certain damage to the body. Se deficiency can reduce the expression and activity of selenoproteins, disrupt the normal physiological function of cells and affect the body in antioxidant, immunity, toxin antagonism, signaling pathways and other aspects, thus causing different degrees of damage to the body. Se intake is mainly in the form of dietary supplements. Due to the important role of Se, people pay increasingly more attention to Se-enriched foods, which also lays a foundation for better research on the mechanism of selenoproteins in the future. In this paper, the synthesis and mechanism of selenoproteins, as well as the role and mechanism of selenoproteins in the regulation of diseases, are reviewed. Meanwhile, the future development of Se-enriched products is prospected, which is of great significance to further understand the role of Se.

Melatonin Nuclear Receptors Mediate Green-and-Blue-Monochromatic-Light-Combinations-Inhibited B Lymphocyte Apoptosis in the Bursa of Chickens via Reducing Oxidative Stress and Nfκb Expression.

Previous studies found that melatonin modulates a combination of green-and-blue-light-induced B-lymphocyte proliferation via its membrane receptors Mel1a and Mel1c. However, in addition to its membrane-bound receptors, melatonin also functions through binding to nuclear receptors RORα/RORß/RORγ. In this study, we raised 120 chicks under 400-700 nm white (WW), 660 nm red (RR), 560 nm green (GG) and 480 nm blue light (BB) from P0 to P26. From P27 to P42, half of the chickens in green, blue and red were switched to blue (G→B), green (B→G) and red (R→B), respectively. We used immunohistochemistry, Western blotting, qRT-PCR, Elisa and MTT to investigate the influence of various monochromatic light combinations on the bursal B lymphocyte apoptosis and oxidative stress levels as well as estimate whether melatonin and its nuclear receptors were involved in this process. Consistent with the increase in the plasma melatonin concentration and antioxidant enzyme activity, we observed that G→B significantly decreased the RORα, RORγ mRNA level, inhibited Bax, Caspase-3 and p-iκb, p-p65 protein expression, increased the IL-10 level and Nrf2, HO-1 protein expression, down-regulated the MDA and pro-inflammatory IL-6, TNF-α and IFN-γ levels in the bursa compared with WW, RR, GG, BB and R→B, respectively. Our in vitro results showed exogenous melatonin supplementation inhibited B-lymphocyte apoptosis, decreased IL-6, TNF-α, IFN-γ and ROS production, down-regulated RORα, RORγ mRNA level and p-iκb and p-p65 protein expression, whereas it improved the IL-10 level and Nrf2 and the HO-1 protein expression in bursal B lymphocyte. Moreover, these responses were abrogated by RORα agonist SR1078 but were mimicked by RORα antagonist SR3335 or RORγ antagonist GSK2981278. In addition, p65 antagonist BAY reversed RORα/RORγ-mediated G→B-inhibited bursal B lymphocyte apoptosis. Overall, we concluded that melatonin nuclear RORα/RORγ mediates G→B-inhibited bursal B lymphocyte apoptosis via reducing oxidative stress and Nfκb expression.

Melatonin prevents the dysbiosis of intestinal microbiota in sleep-restricted mice by improving oxidative stress and inhibiting inflammation.

Background: Intestinal inflammation caused by sleep restriction (SR) threatens human health. However, radical cure of intestinal inflammatory conditions is considerably difficult. This study focuses on the effect of melatonin on SR-induced intestinal inflammation and microbiota imbalance in mice. Methods: We successfully established a water platform to induce long-term SR in mice for 28 days with or without melatonin supplementation. The SR-induced oxidative stress and inflammatory changes were evaluated in plasma and jejunum tissue samples using in vitro assays. Additionally, changes in the intestinal microbiota were explored using high-throughput sequencing of the 16S rRNA gene. Results: After 20 h of chronic sleep restriction for 28 consecutive days, plasma melatonin was significantly reduced by 48.91% (P < 0.05), while GLU, NE, and CORT were significantly increased (34.32%-90.28%, P < 0.05). The activities of antioxidant enzymes (SOD, GSH-Px, and CAT) and T-AOC in intestinal tissues of SR mice were decreased (17.02%-40.92%, P < 0.05), while the content of MDA was increased (15.12%, P = 0.0089). The levels of pro-inflammatory cytokines (IL-6 and TNF-α) ware increased (65.27%-123.26%, P < 0.05), while the levels of anti-inflammatory cytokines (IL-10 and IFN-γ) were decreased (26.53%-60.41%, P < 0.05). High-throughput pyrosequencing of 16S rRNA from jejunum samples demonstrated an overall increase in the number of OTUs (30.68%, P = 0.015). The α-diversity (Shannon, ACE and Chao1) of jejunum was increased (28.18%-48.95%, P < 0.05), and the ß-diversity (PCoA and NMDS) was significantly different from that of the control group (P = 0.001). Furthermore, the prevalences of Helicobacter and Clostridium were higher, whereas that of Bacteroidetes and Lactobacillus were lower in SR mice than in controls (P < 0.05). However, melatonin supplementation reversed the SR-induced changes and improved oxidative stress, inflammatory response, and microbiota dysbiosis in the jejunum, and there was not significant difference compared with the control group (P > 0.05). Conclusions: Melatonin prevents the dysbiosis of intestinal microbiota in SR mice by improving oxidative stress and inhibiting inflammation. Our results may provide a theoretical basis for conducting clinical research on insufficient sleep leading to intestinal health in humans and hence facilitate a better understanding of the role of melatonin.

Marine Products As a Promising Resource of Bioactive Peptides: Update of Extraction Strategies and Their Physiological Regulatory Effects.

Marine products are a rich source of nutritional components and play important roles in promoting human health. Fish, mollusks, shellfish, as well as seaweeds are the major components of marine products with high-quality proteins. During the last several decades, bioactive peptides from marine products have gained much attention due to their diverse biological properties including antioxidant, antihypertensive, antimicrobial, antidiabetic, immunoregulation, and antifatigue. The structural characteristics of marine bioactive peptides largely determine the differences in signaling pathways that can be involved, which is also an internal mechanism to exert various physiological regulatory activities. In addition, the marine bioactive peptides may be used as ingredients in food or nutritional supplements with the function of treating or alleviating chronic diseases. This review presents an update of marine bioactive peptides with the highlights on the novel producing technologies, the physiological effects, as well as their regulation mechanisms. Challenges and problems are also discussed in this review to provide some potential directions for future research.

Trace Element Selenium Effectively Alleviates Intestinal Diseases.

Selenium (Se) is an essential trace element in the body. It is mainly used in the body in the form of selenoproteins and has a variety of biological functions. Intestinal diseases caused by chronic inflammation are among the most important threats to human health, and there is no complete cure at present. Due to its excellent antioxidant function, Se has been proven to be effective in alleviating intestinal diseases such as inflammatory bowel diseases (IBDs). Therefore, this paper introduces the role of Se and selenoproteins in the intestinal tract and the mechanism of their involvement in the mediation of intestinal diseases. In addition, it introduces the advantages and disadvantages of nano-Se as a new Se preparation and traditional Se supplement in the prevention and treatment of intestinal diseases, so as to provide a reference for the further exploration of the interaction between selenium and intestinal health.

Melatonin-Mediated Colonic Microbiota Metabolite Butyrate Prevents Acute Sleep Deprivation-Induced Colitis in Mice.

Radical cure colitis is a severe public health threat worldwide. Our previous studies have confirmed that melatonin can effectively improve gut microbiota disorder and mucosal injury caused by sleep deprivation (SD). The present study further explored the mechanism whereby exogenous melatonin prevented SD-induced colitis. 16S rRNA high-throughput sequencing and metabolomics analysis were used to explore the correlation between SD-induced colitis and intestinal microbiota and metabolite composition in mice. Fecal microbiota transplantation (FMT) and melatonin or butyrate supplementation tests verified the core role of gut microbiota in melatonin-alleviating SD-induced colitis. Further, in vitro tests studied the modulatory mechanism of metabolite butyrate. The results demonstrated that SD leads to reductions in plasma melatonin levels and colonic Card9 expression and consequent occurrence of colitis and gut microbiota disorder, especially the downregulation of Faecalibacterium and butyrate levels. The FMT from SD-mice to normal mice could restore SD-like colitis, while butyrate supplementation to SD-mice inhibited the occurrence of colitis, but with no change in the plasma melatonin level in both treatments. However, melatonin supplementation reversed all inductions in SD-mice. In intestinal epithelial cells, the inflammatory ameliorative effect of butyrate was blocked with pretreatments of HDAC3 agonist and HIF-1α antagonist but was mimicked by GSK-3ß and p-P65 antagonists. Therefore, the administration of MLT may be a better therapy for SD-induced colitis relative to butyrate. A feasible mechanism would involve that melatonin up-regulated the Faecalibacterium population and production of its metabolite butyrate and MCT1 expression and inhibited HDAC3 in the colon, which would allow p-GSK-3ß/ß-catenin/HIF-1α activation and NF-κB/NLRP3 suppression to up-regulate Card9 expression and suppress inflammation response.

Melatonin Alleviates Acute Sleep Deprivation-Induced Memory Loss in Mice by Suppressing Hippocampal Ferroptosis.

Objectives: Memory decline caused by insufficient sleep is a critical public health issues and currently lacks effective treatments. This study objective was to explore alleviative effect of melatonin on sleep deprivation (SD)-induced deficiencies in learning and memory. Materials and Methods: A continuous 72 h SD mouse model, with or without melatonin or Fer-1 supplementation were established. The changes of cognitive function, iron homeostasis, lipid peroxidation and intracellular signal pathways in mice were detected by Morris water maze, antioxidant assay, immunohistochemistry, western blot, RT-PCR and Prussian blue staining. In vitro, we treated HT-22 cells with ferroptosis inducer (Erastin) to further explore the specific mechanism of melatonin in ferroptosis. Results: Mice subjected to SD had significantly elevated latency and path length to reach hidden platform, as well as a decrease in number of entries and time spent in the target zone when the hidden platform was removed (p < 0.05). Nevertheless, supplementation with ferroptosis inhibitor (Fer-1) mitigated the memory impairment associated with SD. Further evaluation revealed an up-regulation of intracellular iron accumulation, transferrin receptor 1 and divalent metal transporter 1 expression and ROS and MDA production, and a down-regulation of ferroportin and antioxidant enzyme (GPX4 and SOD) expression in SD mice. SD decreased expression of MT2 receptor rather than of MT1, and inhibited ERK/Nrf2 signaling activation in the hippocampus (p < 0.05). In contrast, the aforementioned SD-inductions were reversed by supplementation using 20 and 40 mg/kg melatonin in SD mice. In vitro, melatonin pretreatment reversed Erastin-induced ferroptosis, abnormalities in iron transporter protein and antioxidant enzyme expression and suppression of ERK/Nrf2 signaling in HT-22 cells, however this protective effect of melatonin was blocked by MT2-, ERK- and Nrf2-specific antagonists (p < 0.05). Conclusion: Our finding suggested SD may induce ferroptosis, in turn leading to cognitive deficits. Melatonin alleviated memory loss and hippocampal ferroptosis caused by acute SD through binding to the MT2 receptor to activate ERK/Nrf2 signaling.

Melatonin mediates monochromatic light-induced expression of somatostatin in the hypothalamus and pituitary of chicks.

Melatonin (MEL) plays an important role in regulating growth and development of organisms and the cellular metabolism. This study was conducted to explore the role of MEL in mediating monochromatic light-induced secretion of somatostatin (SST) in the hypothalamus and pituitary in chicks. Pinealectomy models of newly hatched broilers were exposed to white (WL), red (RL), green (GL), and blue (BL) lights. The results showed that SST immunoreactive neurons and fibers were distributed in the hypothalamus. SST and SST receptor 2 (SSTR2) mRNA and protein levels in the hypothalamus and pituitary were higher in chicks exposed to RL than in chicks exposed to GL and BL. However, after pinealectomy, the mRNA and protein levels of SST and SSTR2 in the hypothalamus and pituitary in the different light groups were increased, and the differences between the groups disapeared. The expression trend of SSTR5 mRNA in the pituitary was the idential to that of SSTR2 mRNA in the pituitary. In vitro, exogenous SST inhibited growth hormone (GH) secretion, and selective antogonists of SSTR2 and SSTR5 promoted GH secretion. Selective antogonists of the melatonin receptor 1b (Mel1b) and Mel1c increased the relative concentrations of SST in the adenohypophysis cells. These results indicated that monochromatic light affects the expression of SST in chick hypothalamus and pituitary. MEL, via Mel1b and Mel1c, decreased SST secretion under GL, which was associated with the inhibition of SST, SSTR2, and SSTR5 in adenohypophysis cells.

Melatonin Ameliorates Corticosterone-Mediated Oxidative Stress-Induced Colitis in Sleep-Deprived Mice Involving Gut Microbiota.

BACKGROUND: Inflammatory bowel disease (IBD) is a result of a complex interplay, making development of a specific treatment a challenging task. Corticosterone was considered a risk factor of stress relative enteritis. Our previous studies found that melatonin exerts an improvement effect in sleep deprivation (SD)- induced corticosterone overproduction and colitis. A present study further explored the mechanism whereby melatonin prevented corticosterone-mediated SD-induced colitis. METHODS: A 72-hour SD mouse model with or without melatonin supplementation and fecal microbiota transplantation (FMT) to investigate the core role of corticosterone in melatonin-mediated gut microbiota improving SD-induced colitis. Further, corticosterone-treated mice were assessed to the effect of melatonin on corticosterone-mediated gut microbiota dysbiosis-induced colitis. Meanwhile, an in vitro test studied modulatory mechanism of metabolite melatonin. RESULTS: SD caused an excessive corticosterone, gut microbiota disorder and colitis phenotype. Similarly, corticosterone-supplemented mice also exhibited gut microbiota dysbiosis and colitis, and the FMT from SD-mice to normal mice could restore the SD-like colitis, but no change in the corticosterone level, which suggested that corticosterone-mediated intestinal microbiota imbalance plays a central role in SD-induced colitis. Further, we demonstrated melatonin-mediated MT2 weakened GR feedback, suppressed oxidative stress, restored the intestinal microbiota and its metabolites homeostasis, and inactivated the STAT3/AP-1/NF-κB pathway-induced inflammatory response in vivo and in vitro. CONCLUSIONS: We revealed that excessive corticosterone is a core risk factor for SD-induced colitis and provided a better understanding of the effects of melatonin, expected to be a personalized targeted therapy drug, on corticosterone-mediated gut microbiota inducing colitis.