Axis In Mice Research Articles

Luteolin Induced Hippocampal Neuronal Pyroptosis Inhibition by Regulation of miR-124-3p/TNF-α/TRAF6 Axis in Mice Affected by Breast-Cancer-Related Depression.

Background Breast-cancer-related depression (BCRD) is associated with an increased mortality rate among breast cancer (BC) survivors. Luteolin has many pharmacological effects, particularly in the treatment of BC. In this study, we aimed to explore the anti-BCRD activity of luteolin and its underlying functional mechanism. Methods A BCRD mouse model was induced by injecting 4T1 cells and corticosterone (COR). Behavioral test, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, Nissl staining, immunofluorescence, reverse-transcription quantitative PCR (RT-qPCR), and western blotting were used to study the effect of luteolin in mice with BCRD in vivo. A COR-induced neuron injury model was established in HT-22 cells in vitro. The role of miR-124-3p in the anti-BCRD effects of luteolin was studied using a miR-124-3p inhibitor. Results Luteolin significantly reduced the size and weight of the tumor, increased the mice entry frequency in the symmetrical sector, and reduced the duration of immobility in the tail suspension and forced swimming tests of mice affected by BCRD. Simultaneously, apoptosis of hippocampal neurons was inhibited, and the number of Nissl bodies increased with luteolin treatment. In addition, luteolin resulted in the upregulation of miR-124-3p expression in the hippocampus and downregulated the expression of tumor necrosis factor-α (TNF-α) and TNF receptor-associated factor 6 (TRAF6), as well as lowered the phosphorylation levels of nuclear factor-kappa B (NF-κB) and IkappaB (IκB). Luteolin also inhibited pyroptosis of hippocampal neurons in mice affected by BCRD, as revealed by the low protein levels of NOD-like receptor protein 3 (NLRP3), caspase-1, gasdermin D-N (GSDMD-N), interleukin (IL)-1β, and IL-18. However, the miR-124-3p inhibitor significantly reversed the therapeutic effect of luteolin on COR-induced HT-22 cells. Conclusion Our study demonstrated that the anti-BCRD function of luteolin was mediated by regulating the miR-124-3p/TNF-α/TRAF6-related pathway and inhibiting neuronal cell pyroptosis and subsequent inflammation. Therefore, luteolin may be a potential drug candidate in the treatments of BCRD.

MO277: Effect of P-Cresyl Sulfate in Cardiorenal Axis in Mice

Abstract BACKGROUND AND AIMS Uremic toxins (UT) are extremely relevant for the understanding of pathologies of the cardiovascular system once kidney and heart have a close relationship and share different functions. UT are divided into three groups according to physicochemical characteristics: small water-soluble compounds, medium compounds, and protein-bound uremic toxins (PBUT). The PBUT are cytotoxic molecules that have shown deleterious effects in various tissues, including the cardiovascular system. P-Cresyl (PCS), a toxin derived from tyrosine, is one of most important UT once it has a strong affinity for serum proteins, which makes their removal by dialysis difficult. Although some deleterious effects of PCS are known, systematic studies that address the cellular and molecular mechanisms of action of PCS, in the kidney and heart, are still scarce [1, 2]. Moreover, many works in the literature diverge as to the experimental model and the dose of PCS to be used. In this sense, the present study aimed define the dose of PCS capable of leading to renal impairment in mice and also evaluate the effect of PCS alone (without renal injury installed) in kidney and heart. METHODS C57BL/6J male mice 6–8 weeks old (22–28 g) were obtained from the Animal Facility of Federal University of ABC (SP, Brazil). All procedures and protocols were approved by the Ethics Committee on Animal Use of the Federal University of ABC (no. 6 548 291 020). A dose response curve was performed, and the mice were divided into four groups and treated for 21 days, i.p.: Vehicle (saline), PCS 60 mg/L, PCS 40 mg/L and 20 mg/L. Doses were based on uremic maximum concentration available on EUTox-European Uremic Toxins Work Group [3]. After treatment, kidneys, heart, blood, tibia were collected to morphometric and biochemical analysis. Gene expression was evaluated using real-time PCR. RESULTS The EUTox suggested that ∼40 mg/L is the maximum uremic dose for humans. However, the dose–response curve showed that only PCS 20 mg/L was able to increase the mRNA levels of renal injury markers such as Cystatin (3x), KIM-1 (6x) and Vimentin (12x) in relation to control animals (P < .05). Besides, it was possible to observe a decrease on mRNA gene expression of IL-1β levels in kidney (40%, P < .05) when compared with control group. No alterations were observed in MCP-1 levels. In relation to cardiac changes, heart weight/tibia length ratio, showed a cardiac atrophy about 13% after PCS treatment. The OAT 1 and 3 expression did not alter after different doses of PCS treatment. CONCLUSION The results indicated that lowest dose of PCS was able to promote renal injury and cardiac remodeling, despite the changes in OAT1 and OAT3 in kidney and heart. In addition, the establishment of critical dose in mice model is very important since the use of knockout mice models could help to understand the role of UT in organ–organ crosstalk. Finally, this study indicates that the PCS has an impact in kidney/heart axis independent of previous renal injury. The molecular mechanisms involved in cardiac atrophy and inflammatory status are being investigated by our group.

Knockout of circRNA single stranded interacting protein 1 (circRBMS1) played a protective role in myocardial ischemia-reperfusion injury though inhibition of miR-2355-3p/Mammalian Sterile20-like kinase 1 (MST1) axis

ABSTRACT Evidence suggests circRBMS1 regulates mRNA to mediate cell apoptosis, inflammation, and oxidative stress in different diseases. MST1 is reported to be the target and activator of apoptosis-related molecules and signaling pathways. Hence, the present study aims to investigate the role of circ-RBMS1/miR-2355-3p/MST1 in the development of I/R injury. In vitro experiments showed increased circ-RBMS1 and decreased miR-2355-3p in H/R-induced HCMs. CircRBMS1 served as a sponge for miR-2355-3p and miR-2355-3p targeted MST1. Furthermore, knockout of circRBMS1 attenuated cell apoptosis, oxidized stress, and inflammation in H/R-induced HCMs. In vivo experiments indicated circRBMS1 knockdown attenuated cardiac function damage, cell apoptosis, oxidative stress injury and inflammatory response through miR-2355-3p/MST1 axis in mice. In summary, these results demonstrated circRBMS1 played a protective role in myocardial I/R injury though inhibition of miR-2355-3p/MST1 axis. It might provide a new therapeutic target for cardiac I/R injury.

Cross Brain-Gut Analysis Highlighted Hub Genes and LncRNA Networks Differentially Modified During Leucine Consumption and Endurance Exercise in Mice with Depression-Like Behaviors.

Depression is a frequent mood disorder that might impair the brain-gut axis. In this study, we divided 30 mice into five groups: untreated mice, mice with depression-like behaviors, mice with depression-like behaviors treated with consumed leucine, mice with depression-like behaviors treated with exercise training, mice with depression-like behaviors treated with exercise training along with consumed leucine. According to artificial intelligence biological analysis, we found some mediators such as lncRNAs profile and Kdr/Vegfα/Pten/Bdnf interactions network in the hippocampus region and ileum tissue which could be decisive molecules in the brain-gut axis. Moreover, KDR as a principal cutpoint protein in the network was identified as the pharmaceutical approach for major depressive ameliorating based on pharmacophore modeling and molecular docking outcomes. Furthermore, we indicated that the mRNA and protein level of the Pten enhanced and Vegfα/Kdr/Bdnf mRNAs, as well as the protein level of KDR, decreased in mice with depression-like behaviors. Moreover, exercise and leucine ameliorated the brain-gut axis in mice with depression-like behaviors. Exercise and leucine regulated the lncRNAs network in the hippocampus and ileum of mice with depression-like behaviors. We suggest that the lncRNAs profiles could be considered as diagnosis and prognosis biomarkers, and exercise + leucine might be a practical approach to improve depression.

Modulation of innate immune response to viruses including SARS-CoV-2 by progesterone

Whether and how innate antiviral response is regulated by humoral metabolism remains enigmatic. We show that viral infection induces progesterone via the hypothalamic-pituitary-adrenal axis in mice. Progesterone induces downstream antiviral genes and promotes innate antiviral response in cells and mice, whereas knockout of the progesterone receptor PGR has opposite effects. Mechanistically, stimulation of PGR by progesterone activates the tyrosine kinase SRC, which phosphorylates the transcriptional factor IRF3 at Y107, leading to its activation and induction of antiviral genes. SARS-CoV-2-infected patients have increased progesterone levels, and which are co-related with decreased severity of COVID-19. Our findings reveal how progesterone modulates host innate antiviral response, and point to progesterone as a potential immunomodulatory reagent for infectious and inflammatory diseases.

A Synbiotic Combination of Lactobacillus gasseri 505 and Cudrania tricuspidata Leaf Extract Prevents Stress-Induced Testicular Dysfunction in Mice.

This study investigated the effects of a synbiotic combination (Syn) of Lactobacillus gasseri 505 (505) and Cudrania tricuspidata leaf extract (CT) on the hypothalamic-pituitary-gonadal axis in mice under chronic stress. Unpredictable chronic mild stress (UCMS) significantly increased the serum levels of corticosterone, however, treatment with Syn suppressed UCMS-induced increases. Histopathological analysis of the testes showed that these organs experienced some damage during UCMS, but this was repaired following treatment with Syn. Similarly, the transcription levels of gonadotropin-releasing hormone (GnRH), GnRH receptor, and gonadotropins, moreover, testicular development (i.e., Adam5, Adam29, and Spam1) - and steroidogenesis (i.e., Lhr, Egfr, and StAR) -related genes were significantly downregulated by UCMS. These UCMS-induced changes were inhibited by the administration of Syn, which was confirmed by the results of in situ hybridization analysis. These results suggest that the administration of Syn could attenuate the testicular dysfunctions induced by UCMS.

Biochanin A alleviates unilateral ureteral obstruction-induced renal interstitial fibrosis and inflammation by inhibiting the TGF-β1/Smad2/3 and NF-kB/NLRP3 signaling axis in mice

AimsTubulointerstitial fibrosis, a frequent complication of chronic kidney disease (CKD) is a major public health issue. Biochanin A (BCA), an isoflavone, has numerous pharmacological activities. However, its effect on renal fibrosis and underlying molecular mechanism has not yet been clarified. This study explored the effect of BCA on renal tubulointerstitial fibrosis and inflammation in mice. Main methodsThe mouse model of unilateral ureteral obstruction (UUO) in vivo and transforming growth factor (TGF)-β1 activated renal fibroblast (NRK 49F) cells in vitro model were used to assess the antifibrotic effect of BCA. Biochemical analysis, histopathology, western blotting, and immunofluorescent staining methods were performed to elucidate the mechanism of BCA. Key findingsIn vitro, BCA suppressed the expression of fibrogenic proteins in TGF-β1-activated renal fibroblasts. The treatment with BCA displayed less tubular injury, prevented the aberrant accumulation of extracellular matrix (ECM) components, and inhibited the TGF-β1/Smad2/3 signaling axis in the kidneys. Furthermore, BCA impeded the phosphorylation of NF-kB(p65) and blunted the expression of inflammatory genes in the obstructed kidneys. The UUO induced expressions of nod-like receptor protein 3 (NLRP3), active caspase 1, interleukin(IL)-18, and IL-1β proteins were decreased in the BCA treated groups. We also found the increased expression of redox-sensitive nuclear factor erythroid 2–related factor 2 (Nrf2) and heme oxygenase 1 (HO-1) proteins in BCA treated groups compared to the UUO control. SignificanceThese findings indicate that BCA has a therapeutic benefit against renal fibrosis, and the ameliorative effect is mediated via inhibiting the TGF-β1/Smad2/3 and NF-kB/NLRP3 signaling axis.

Alginate Oligosaccharide Alleviated Cisplatin-Induced Kidney Oxidative Stress via Lactobacillus Genus-FAHFAs-Nrf2 Axis in Mice.

Alginate oligosaccharide is the depolymerized product of alginate, a natural extract of brown algae, which is associated with beneficial health effects. Here, we aimed to investigate the mechanism via which alginate oligosaccharides improve kidney oxidative damage and liver inflammation induced by cisplatin chemotherapy via the gut microbiota. C57BL/6J mice were treated with cisplatin were administered alginate oligosaccharide via gavage for 3 weeks. Compared to that observed in the cisplatin chemotherapy group without intragastric administration of alginate oligosaccharide, liver inflammation improved in the alginate oligosaccharide group, indicated by reduction in lipopolysaccharide and interleukin-1β (IL-1β) levels. This was accompanied by improvement in the oxidative stress of mice kidneys, indicated by the increase in the levels of superoxide dismutase (SOD), catalase (CAT) and nuclear NF-E2-related factor 2 (Nrf2) in renal tissue, and reduction in the levels of malondialdehyde (MDA) in renal tissue and serum creatinine (Cr) to the levels of the normal control group. Alginate oligosaccharide intervention increased the concentration of fatty acid esters of hydroxy fatty acids (FAHFAs). Alginate oligosaccharide regulated the composition of the intestinal microbial community and promoted Lactobacillus stains, such as Lactobacillus johnsonii and Lactobacillus reuteri. Spearman analysis showed that 5 members of FAHFAs concentrations were positively correlated with Lactobacillus johnsonii and Lactobacillus reuteri abundance. We observed that alginate oligosaccharide increased FAHFAs producing-related bacterial abundance and FAHFAs levels, enhanced the levels of SOD and CAT in kidney tissue, and reduced the levels of MDA via activating Nrf2, thereby ameliorating the renal redox injury caused by cisplatin chemotherapy.

Histamine Causes Pyroptosis of Liver by Regulating Gut-Liver Axis in Mice.

Huangjiu usually caused rapid-drunkenness and components such as β-benzyl ethanol (β-be), isopentanol (Iso), histamine (His), and phenethylamine (PEA) have been reported linked with intoxication. However, the destructive effect of these components on gut microbiota and liver is unclear. In this study, we found oral treatment of these components, especially His, stimulated the level of oxidative stress and inflammatory cytokines in liver and serum of mice. The gut microbiota community was changed and the level of lipopolysaccharide (LPS) increased significantly. Additionally, cellular pyroptosis pathway has been assessed and correlation analysis revealed a possible relationship between gut microbiota and liver pyroptosis. We speculated oral His treatment caused the reprogramming of gut microbiota metabolism, and increased LPS modulated the gut-liver interaction, resulting in liver pyroptosis, which might cause health risks. This study provided a theoretical basis for the effect of Huangjiu, facilitating the development of therapeutic and preventive strategies for related inflammatory disorders.

TL1A/DR3 Axis, A Key Target of TNF-a, Augments the Epithelial-Mesenchymal Transformation of Epithelial Cells in OVA-Induced Asthma.

Tumor necrosis factor (TNF)-like cytokine 1A (TL1A), a member of the TNF family, exists in the form of membrane-bound (mTL1A) and soluble protein (sTL1A). TL1A binding its only known functional receptor death domain receptor 3 (DR3) affects the transmission of various signals. This study first proposed that the TL1A/DR3 axis was significantly upregulated in patients and mice with both asthma and high TNF-a expression and in TNF-a-stimulated epithelial Beas-2B cells. Two independent approaches were used to demonstrate that the TL1A/DR3 axis of mice was strongly correlated with TNF-a in terms of exacerbating asthmatic epithelial–mesenchymal transformation (EMT). First, high expression levels of EMT proteins (e.g., collagen I, fibronectin, N-cadherin, and vimentin) and TL1A/DR3 axis were observed when mice airways were stimulated by recombinant mouse TNF-a protein. Moreover, EMT protein and TL1A/DR3 axis expression synchronously decreased after mice with OVA-induced asthma were treated with infliximab by neutralizing TNF-a activity. Furthermore, the OVA-induced EMT of asthmatic mice was remarkably improved upon the deletion of the TL1A/DR3 axis by knocking out the TL1A gene. TL1A siRNA remarkably intervened EMT formation induced by TNF-a in the Beas-2B cells. In addition, EMT was induced by the addition of high concentrations of recombinant human sTL1A with the cell medium. The TL1A overexpression via pc-mTL1A in vitro remarkably increased the EMT formation induced by TNF-a. Overall, these findings indicate that the TL1A/DR3 axis may have a therapeutic role for asthmatic with high TNF-a level.

Obesity Reshapes the Microbial Population Structure along the Gut-Liver-Lung Axis in Mice

The microbiome is emerging as a major player in tissue homeostasis in health and disease. Gut microbiome dysbiosis correlates with several autoimmune and metabolic diseases, while high-fat diets and ensuing obesity are known to affect the complexity and diversity of the microbiome, thus modulating pathophysiology. Moreover, the existence of a gut-liver microbial axis has been proposed, which may extend to the lung. In this context, we systematically compared the microbiomes of the gut, liver, and lung of mice fed a high-fat diet to those of littermates fed a matched control diet. We carried out deep sequencing of seven hypervariable regions of the 16S rRNA microbial gene to examine microbial diversity in the tissues of interest. Comparison of the local microbiomes indicated that lung tissue has the least diverse microbiome under healthy conditions, while microbial diversity in the healthy liver clustered closer to the gut. Obesity increased microbial complexity in all three tissues, with lung microbial diversity being the most modified. Obesity promoted the expansion of Firmicutes along the gut-liver-lung axis, highlighting staphylococcus as a possible pathologic link between obesity and systemic pathophysiology, especially in the lungs.

Adenosine A2A Receptor Suppressed Astrocyte-Mediated Inflammation Through the Inhibition of STAT3/YKL-40 Axis in Mice With Chronic Cerebral Hypoperfusion-induced White Matter Lesions.

White matter lesions are an important pathological manifestation of cerebral small vessel disease, with inflammation playing a pivotal role in their development. The adenosine A2a receptor (ADORA2A) is known to inhibit the inflammation mediated by microglia, but its effect on astrocytes is unknown. Additionally, although the level of YKL-40 (expressed mainly in astrocytes) has been shown to be elevated in the model of white matter lesions induced by chronic cerebral hypoperfusion, the specific regulatory mechanism involved is not clear. In this study, we established in vivo and in vitro chronic cerebral hypoperfusion models to explore whether the ADORA2A regulated astrocyte-mediated inflammation through STAT3/YKL-40 axis and using immunohistochemical, western blotting, ELISA, PCR, and other techniques to verify the effect of astrocytes ADORA2A on the white matter injury. The in vivo experiments showed that activation of the ADORA2A decreased the expression of both STAT3 and YKL-40 in the astrocytes and alleviated the white matter injury, whereas its inhibition had the opposite effects. Similarly, ADORA2A inhibition significantly increased the expression of STAT3 and YKL-40 in astrocytes in vitro, with more proinflammatory cytokines being released by astrocytes. STAT3 inhibition enhanced the inhibitory effect of ADORA2A on YKL-40 synthesis, whereas its activation reversed the phenomenon. These results suggest that the activation of ADORA2A in astrocytes can inhibit the inflammation mediated by the STAT3/YKL-40 axis and thereby reduce white matter injury in cerebral small vessel disease.

Antidepressant effects of Enterococcus faecalis 2001 through the regulation of prefrontal cortical myelination via the enhancement of CREB/BDNF and NF-κB p65/LIF/STAT3 pathways in olfactory bulbectomized mice

A therapeutic strategy through the gut–brain axis has been proven to be effective in treatment for depression. In our previous study, we demonstrated that Enterococcus faecalis 2001 (EF-2001) prevents colitis-induced depressive-like behavior through the gut–brain axis in mice. More recently, we found that demyelination in the prefrontal cortex (PFC) was associated with depressive-like behavior in an animal model of major depressive disorder, olfactory bulbectomized (OBX) mice. The present study investigated the effects of EF-2001 on depressive-like behaviors in OBX mice and the underlying molecular mechanisms from the perspective of myelination in the PFC. OBX mice exhibited depressive-like behaviors in the tail-suspension, splash, and sucrose preference tests, and decreased myelin and paranodal proteins along with mature oligodendrocytes in the PFC. These behavioral and biochemical changes were all prevented by treatment with EF-2001. Further, EF-2001 treatment increased brain-derived neurotrophic factor (BDNF) and leukemia inhibitory factor (LIF) in the PFC. Interestingly, an immunohistochemical analysis revealed enhanced phospho (p) -cAMP-responsive element binding protein (CREB) expression in neurons, p-nuclear factor-kappa B (NFκB) p65 (Ser536) expression in astrocytes, and p-signal transducer and activator of transcription 3 (STAT3) (Ty705) expression in mature oligodendrocytes in the PFC of OBX mice. From these results, we suggest that EF-2001 administration prevents depressive-like behaviors by regulating prefrontal cortical myelination via the enhancement of CREB/BDNF and NFκB p65/LIF/STAT3 pathways. Our findings strongly support the idea that a therapeutic strategy involving the gut microbiota may be a promising alternative treatment for alleviating symptoms of depression.

CREB1 transcription-activated lncRNA PVT1 promotes cardiac fibrosis via miR-145/HCN1 axis

BackgroundCardiac fibrosis is a common pathological process of most cardiac diseases, which may result in cardiac function impairment. Long noncoding RNAs (lncRNAs) have been verified as crucial regulators of cardiac fibrosis. This study explored the function and molecular mechanism of PVT1 in cardiac fibrosis. MethodsTGF-β1-exposed human cardiac fibroblasts (HCF-a) and isoproterenol (ISO)-treated mice were used as the in vitro and in vivo cardiac fibrosis models. PVT1, miR-145, and HCN1 expression was determined by quantitative RT-PCR. Cell proliferation was evaluated by CCK-8 and EdU fluorescence staining. α-SMA and collagen I expression was assessed by immunohistochemical staining and immunofluorescence staining. Protein levels of fibrosis-related factors were assessed by Western blotting. The interaction between miR-145 and PVT1/HCN1 was evaluated by dual luciferase assay. ChIP assay was used to validate the binding of CREB1 to the promoter of PVT1. Cardiac fibrosis in mice was observed by H&E and Masson's trichrome staining. ResultsPVT1 and HCN1 were up-regulated, while miR-145 was down-regulated in the cardiac fibrosis models. PVT1 knockdown restrained TGF-β1-induced proliferation and activation of HCF-a cells. CREB1 bound to the promoter of PVT1 and activated its transcription. Mechanistically, PVT1 enhanced HCN1 expression via sponging miR-145. Finally, silencing of PVT1 attenuated cardiac fibrosis via regulating miR-145/HCN1 axis in mice in vivo. ConclusionPVT1 contributed to cardiac fibrosis by increasing HCN1 expression via sponging miR-145, which suggested that targeting PVT1 may be a therapeutic option for cardiac fibrosis and cardiac diseases.

Luteolin increases slow muscle fibers via FLCN-AMPK-PGC-1α signaling pathway

• Luteolin may improve endurance exercise capacity of mice. • Luteolin may increase slow muscle fibers proportion both in mice and C2C12 myotubes. • Luteolin may activate FLCN-AMPK-PGC-1α axis in mice’s muscle and C2C12 myotubes. • FLCN-AMPK-PGC-1α axis may play key role in luteolin induced slow myofibers increasing. While the regulating mechanisms of slow myofibers have been gradually explored, there are currently a lack of effective means to increase slow myofibers proportion. Here, we have showed that luteolin could markedly improve endurance exercise performance and increase body oxygen consumption of mice, and activate aerobic enzyme activity and slow myofibers related genes and proteins expression in mice’s skeletal muscle. Meanwhile, folliculin (FLCN)-AMP-activated protein kinase (AMPK) -peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) pathway was activated by treatment luteolin in the tissues. Furthermore, by in vitro investigation and FLCN lentivirus infection, we have found that the over-expression of FLCN significantly reduces the effects of luteolin on slow myofibers expression and AMPK-PGC-1α axis activation. Together, our results indicate that luteolin can increase the proportion of slow myofibers probably by FLCN-AMPK-PGC-1α pathway. These findings provide a novel approach to increase slow muscle fibers proportion and improve skeletal muscle fitness.

Leonurine hydrochloride-a new drug for the treatment of menopausal syndrome: Synthesis, estrogen-like effects and pharmacokinetics

This research aimed to investigate the estrogen-like effects of Leonurine hydrochloride (Leo). First, we developed a total synthesis of Leo from 3,4,5-trimethoxy-benzoic acid and the structure was confirmed through 1H NMR and mass spectrometry (MS). Then the estrogenic activity of Leo in vitro and in vivo was studied. The proliferation and proliferation inhibitory effects of Leo on MCF-7 cells and MDA-MB-231 cells indicate that Leo exerts estrogen-like effects through estrogen receptor α (ERα) and estrogen receptor β((ERβ) in vitro. Uterotrophic assay in juvenile mice showed that Leo has an estrogen-like effect in vivo, as it can promote the development of the uterus of juvenile mice, increase its uterine coefficient and the size of the uterine cavity, as well as the increased number of uterine glands and the thickened uterine wall. For further research, cyclophosphamide (CTX) was used to establish a mouse model of ovarian function decline. Through this model, we found that Leo can restore the estrous cycle of mice, increase the number of primordial and primary follicles in the ovaries of mice, and regulate the disordered hypothalamic-pituitary-ovarian (HPOA) axis of mice. Finally, the pharmacokinetics of Leo was studied and oral bioavailability of Leo was calculated to be 2.21%. Leo was synthesized and the estrogen-like effect in vitro and in vivo was confirmed as well as its pharmacokinetics.

Tilapia Head Protein Hydrolysate Attenuates Scopolamine-Induced Cognitive Impairment through the Gut-Brain Axis in Mice.

The destruction of the homeostasis in the gut-brain axis can lead to cognitive impairment and memory decline. Dietary intervention with bioactive peptides from aquatic products is an innovative strategy to prevent cognitive deficits. The present study aimed to determine the neuroprotective effect of tilapia head protein hydrolysate (THPH) on scopolamine-induced cognitive impairment in mice, and to further explore its mechanism through the microbiota–gut-brain axis. The results showed that THPH administration significantly improved the cognitive behavior of mice, and normalized the cholinergic system and oxidative stress system of the mice brain. The histopathological observation showed that THPH administration significantly reduced the pathological damage of hippocampal neurons, increased the number of mature neurons marked by NeuN and delayed the activation of astrocytes in the hippocampus of mice. In addition, THPH administration maintained the stability of cholinergic system, alleviated oxidative stress and further improved the cognitive impairment by reshaping the gut microbiota structure of scopolamine-induced mice and alleviating the disorder of lipid metabolism and amino acid metabolism in serum. In conclusion, our research shows that THPH supplementation is a nutritional strategy to alleviate cognitive impairment through the gut-brain axis.

Black Tea Alleviates Particulate Matter-Induced Lung Injury via the Gut-Lung Axis in Mice.

Black tea, as the most consumed kind of tea, is shown to have beneficial effects on human health. However, its impact on particulate matter (PM) induced lung injury and the mechanisms involved have been sparsely addressed. Here, we show that PM-exposed mice exhibited oxidative stress and inflammation in the lungs, which was significantly alleviated by a daily intake of black tea infusion (TI) in a concentration-dependent manner. Interestingly, both the ethanol-soluble fraction (ES) and the ethanol precipitate fraction (EP) exhibited better effects than those of TI; moreover, EP tended to have stronger protection than ES in some indicators, implying that EP played a dominant role in the prevention effects. Furthermore, fecal microbiota transplantation (FMT) revealed that the gut microbiota was differentially reshaped by TI and its fractions were able to directly alleviate the injury induced by PMs. These results indicate that daily intake of black tea and its fractions, especially EP, may alleviate particulate matter-induced lung injury via the gut-lung axis in mice. In addition, the Lachnospiraceae_NK4A136_group could be the core gut microbe contributing to the protection of EP and thus should be further studied in the future.

Abstract 11561: Pharmacological Inhibition of Rage/diaph1 Axis Enhances Weight Loss in Diet Induced Obese Mice and Improves Glucose Homeostasis

Introduction: The incidence of obesity and its comorbidities has soared at an alarming rate in US and around the world. Our previous studies have shown that the receptor for advanced glycation end products (RAGE) and its ligands contribute to the pathogenesis of obesity and insulin resistance. Both global and adipocyte-specific Ager (gene encoding RAGE) deleted mice fed a high fat diet (HFD) showed protection from weight gain and insulin resistance. However, if RAGE deletion/inhibition affects weight loss in mice with established obesity is under investigation. We have discovered novel small molecule antagonists of the interaction between the cytoplasmic domain of RAGE with its intracellular effector Diaphanous 1(DIAPH1). We tested the hypothesis that these chow containing small molecule antagonists vs. vehicle might enhance weight loss and improve metabolic function in obese mice undergoing weight loss. Methods: Male mice (C57BL/6, N=78) were fed HFD (60% kcal/fat) for 20 weeks starting at 8 weeks of age to establish obesity; mice were then switched to either low fat RAGE/DIAPH1 inhibitor diet (N=40) or vehicle diet (N=38). Body mass was serially monitored and after six weeks of medicated chow vs. vehicle, glucose and insulin tolerance, body composition, plasma insulin and lipids were measured. Adipocyte size was monitored by histology. Results: Six weeks administration of RAGE/DIAPH1 antagonist in mice with established obesity resulted in significantly greater weight loss and fat mass vs. vehicle treatment. Further, metabolic recovery was enhanced, as evidenced by greater improvement in glucose tolerance and reduced plasma insulin and cholesterol levels. Histology revealed that epididymal and subcutaneous adipose tissues displayed smaller mean adipocyte size in mice receiving the RAGE/DIAPH1 antagonists vs. vehicle. Conclusion: Pharmacological inhibition of RAGE/DIAPH1 axis in mice with established obesity enhances weight loss, and improves metabolic recovery.

Proteomics analysis of the gut\u2013brain axis in a gut microbiota-dysbiosis model of depression

Major depressive disorder (MDD) is a serious mental illness. Increasing evidence from both animal and human studies suggested that the gut microbiota might be involved in the onset of depression via the gut–brain axis. However, the mechanism in depression remains unclear. To explore the protein changes of the gut–brain axis modulated by gut microbiota, germ-free mice were transplanted with gut microbiota from MDD patients to induce depression-like behaviors. Behavioral tests were performed following fecal microbiota transplantation. A quantitative proteomics approach was used to examine changes in protein expression in the prefrontal cortex (PFC), liver, cecum, and serum. Then differential protein analysis and weighted gene coexpression network analysis were used to identify microbiota-related protein modules. Our results suggested that gut microbiota induced the alteration of protein expression levels in multiple tissues of the gut–brain axis in mice with depression-like phenotype, and these changes of the PFC and liver were model specific compared to chronic stress models. Gene ontology enrichment analysis revealed that the protein changes of the gut–brain axis were involved in a variety of biological functions, including metabolic process and inflammatory response, in which energy metabolism is the core change of the protein network. Our data provide clues for future studies in the gut–brain axis on protein level and deepen the understanding of how gut microbiota cause depression-like behaviors.