Feeding Mice Research Articles

Ang II Promotes ET-1 Production by Regulating NOX2 Activity Through Transcription Factor Oct-1.

Increasing evidence suggests that superoxide ions produced by NOX (nicotinamide adenine dinucleotide phosphate oxidases) mediate vascular effects of Ang II (angiotensin II) evoked by atherogenic diets. Here, we analyzed the mechanism by which NOX2 contributes to Ang II-induced ET-1 (endothelin 1) production in human microvascular endothelial cells. The effects of high-fat diet were compared between WT (wild type) and Nox2 (mouse NOX2 gene)-deficient mice. ET-1 production and NOX2 expression by human microvascular endothelial cells in vitro were analyzed by ELISA, reverse transcription quantitative polymerase chain reaction, electrophoretic mobility shift assay, promoter deletions, RNA interference, and pharmacological inhibition. Production of superoxide anions was visualized by fluorescent cell labeling. Feeding mice high-fat diet for 10 weeks increased cardiac expression and plasma levels of Ang II and ET-1 in WT but not in Nox2-deficient animals. Exposure of human microvascular endothelial cells to Ang II resulted in increased ET-1 production, which could be blocked by silencing NOX2 (human NOX2 gene). Ang II promoted NOX2 expression through induction of the Oct-1 (human/mouse octamer binding transcription factor 1 protein) and activation of the NOX2 promoter region containing Oct-1-binding sites. Stimulation of NOX2 expression by Ang II was associated with increased production of superoxide anions. Inhibition of Oct-1 by small interfering RNA reduced Ang II-induced NOX2 expression and superoxide anion production, and neutralization of superoxide by SOD (superoxide dismutase) abolished Ang II-stimulated ET1 (human ET-1 gene) promoter activity, ET1 mRNA expression, and ET-1 release. Ang II may promote ET-1 production in the endothelium in response to atherogenic diets through a mechanism that involves the transcription factor Oct-1 and the increased formation of superoxide anions by NOX2.

268-LB: Dietary Resistant Starch Supplementation Upregulates Deoxycholic Acid Production in Mice

The gut microbiome plays an important role in the regulation of metabolic health, largely through the metabolites it produces, making it an important target for management and prevention of diabetes. Some of the most abundant metabolites produced by the gut microbiome are bile acids. Primary bile acids produced in the liver are converted into secondary bile acids by bacteria in the gut via 7-ɑ-dehydroxylation. These secondary bile acids are strong ligands for bile acid receptors known to improve glycemic regulation. However, the bacteria and enzymatic pathways involved in 7-ɑ-dehydroxylation have not been fully defined. Therefore, we are developing tools with which to study the dynamic regulation of gut bacterial 7-ɑ-dehydroxylation. In this study, we hypothesized that feeding mice a diet rich in resistant starch (RS) would alter the gut microbiome to favor bacteria capable of executing 7-ɑ-dehydroxylation. To test this, mice were fed a diet supplemented with RS or an isocaloric (IC) control diet. Profiling of gut luminal bile acids shows that RS supplementation proportionally increases the production of the secondary bile acid, deoxycholic acid (DCA) (DCA as a proportion of total bile acids in gut luminal contents: IC = 0.16 ± 0.03 RS = 0.55 ± 0.08, P = 0.001). RS tended to decrease unconjugated cholic acid (CA) concentrations, the substrate for 7-ɑ-dehydroxylation in DCA production, compared to IC-fed controls. Hepatic expression of the enzyme required for production of CA, Cyp8b1, did not differ between groups. Therefore, these data suggest that RS-induced increases in DCA are due to increased gut bacterial conversion of CA to DCA. Determining which bacteria can carry out 7-ɑ-dehydroxylation is critical to targeting gut bacterial bile acid metabolism. This study demonstrates that RS supplementation upregulates DCA production, identifying RS supplementation as a tool with which to define the dynamic regulation of 7-ɑ-dehydroxylation by gut bacteria. Disclosure M. Reuter: None. M. Tucker: None. Z. Marfori: None. R. Shishani: None. J. M. Bustamante: None. R. Moreno: None. B. Cummings: None.

Strontium Attenuates Hippocampal Damage via Suppressing Neuroinflammation in High-Fat Diet-Induced NAFLD Mice.

Non-alcoholic fatty liver disease (NAFLD) leads to hippocampal damage and causes a variety of physiopathological responses, including the induction of endoplasmic reticulum stress (ERS), neuroinflammation, and alterations in synaptic plasticity. As an important trace element, strontium (Sr) has been reported to have antioxidant effects, to have anti-inflammatory effects, and to cause the inhibition of adipogenesis. The present study was undertaken to investigate the protective effects of Sr on hippocampal damage in NAFLD mice in order to elucidate the underlying mechanism of Sr in NAFLD. The mouse model of NAFLD was established by feeding mice a high-fat diet (HFD), and the mice were treated with Sr. In the NAFLD mice, we found that treatment with Sr significantly increased the density of c-Fos+ cells in the hippocampus and inhibited the expression of caspase-3 by suppressing ERS. Surprisingly, the induction of neuroinflammation and the increased expression of inflammatory cytokines in the hippocampus following an HFD were attenuated by Sr treatment. Sr significantly attenuated the activation of microglia and astrocytes induced by an HFD. The expression of phospho-p38, ERK, and NF-κB was consistently significantly increased in the HFD group, and treatment with Sr decreased their expression. Moreover, Sr prevented HFD-induced damage to the ultra-structural synaptic architecture. This study implies that Sr has beneficial effects on repairing the damage to the hippocampus induced by an HFD, revealing that Sr could be a potential candidate for protection from neural damage caused by NAFLD.

Multi-omics approach for identification of molecular alterations of QiShenYiQi dripping pills in heart failure with preserved ejection fraction

Ethnopharmacological relevanceTraditional Chinese medicine theory believes that qi deficiency and blood stasis are the key pathogenesis of heart failure with preserved ejection fraction (HFpEF). As a representative prescription for replenishing qi and activating blood, QiShenYiQi dripping pills (QSYQ) has been used for treating heart diseases. However, the pharmacological mechanism of QSYQ in improving HFpEF is not well understood. Aim of the studyThe objective of the study is to investigate the cardioprotective effect and mechanism of QSYQ in HFpEF using the phenotypic dataset of HFpEF. Materials and methodsHFpEF mouse models established by feeding mice combined high-fat diet and Nω-nitro-L-arginine methyl ester drinking water were treated with QSYQ. To reveal causal genes, we performed a multi-omics study, including integrative analysis of transcriptomics, proteomics, and metabolomics data. Moreover, adeno-associated virus (AAV)-based PKG inhibition confirmed that QSYQ mediated myocardial remodeling through PKG. ResultsComputational systems pharmacological analysis based on human transcriptome data for HFpEF showed that QSYQ could potentially treat HFpEF through multiple signaling pathways. Subsequently, integrative analysis of transcriptome and proteome showed alterations in gene expression in HFpEF. QSYQ regulated genes involved in inflammation, energy metabolism, myocardial hypertrophy, myocardial fibrosis, and cGMP-PKG signaling pathway, confirming its function in the pathogenesis of HFpEF. Metabolomics analysis revealed fatty acid metabolism as the main mechanism by which QSYQ regulates HFpEF myocardial energy metabolism. Importantly, we found that the myocardial protective effect of QSYQ on HFpEF mice was attenuated after RNA interference-mediated knock-down of myocardial PKG. ConclusionThis study provides mechanistic insights into the pathogenesis of HFpEF and molecular mechanisms of QSYQ in HFpEF. We also identified the regulatory role of PKG in myocardial stiffness, making it an ideal therapeutic target for myocardial remodeling.

C–C motif chemokine CCL11 is a novel regulator and a potential therapeutic target in non-alcoholic fatty liver disease

Background & AimsNon-alcoholic fatty liver disease (NAFLD) is characterised by accelerated lipid deposition, aberrant inflammation, and excessive extracellular matrix production in the liver. Short of effective intervention, NAFLD can progress to cirrhosis and hepatocellular carcinoma. In the present study we investigated the involvement of the C–C motif ligand 11 (CCL11) in NAFLD pathogenesis. MethodsNAFLD was induced by feeding mice with a high-fat high-carbohydrate diet. CCL11 targeting was achieved by genetic deletion or pharmaceutical inhibition. The transcriptome was analysed using RNA-seq. ResultsWe report that CCL11 expression was activated at the transcription level by free fatty acids (palmitate) in hepatocytes. CCL11 knockdown attenuated whereas CCL11 treatment directly promoted production of pro-inflammatory/pro-lipogenic mediators in hepatocytes. Compared with wild-type littermates, CCL11 knockout mice displayed an ameliorated phenotype of NAFLD when fed a high-fat high-carbohydrate diet as evidenced by decelerated body weight gain, improved insulin sensitivity, dampened lipid accumulation, reduced immune cell infiltration, and weakened liver fibrosis. RNA-seq revealed that interferon regulatory factor 1 as a mediator of CCL11 induced changes in hepatocytes. Importantly, CCL11 neutralisation or antagonism mitigated NAFLD pathogenesis in mice. Finally, a positive correlation between CCL11 expression and NAFLD parameters was identified in human patients. ConclusionsOur data suggest that CCL11 is a novel regulator of NAFLD and can be effectively targeted for NAFLD intervention. Impact and implicationsNon-alcoholic fatty liver disease (NAFLD) precedes cirrhosis and hepatocellular carcinoma. In this paper we describe the regulatory role of CCL11, a C–C motif ligand chemokine, in NAFLD pathogenesis. Our data provide novel insights and translational potential for NAFLD intervention.

Electromagnetic fields ameliorate hepatic lipid accumulation and oxidative stress: potential role of CaMKKβ/AMPK/SREBP-1c and Nrf2 pathways

BackgroundNonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide, and is related to disturbed lipid metabolism and redox homeostasis. However, a definitive drug treatment has not been approved for this disease. Studies have found that electromagnetic fields (EMF) can ameliorate hepatic steatosis and oxidative stress. Nevertheless, the mechanism remains unclear.MethodsNAFLD models were established by feeding mice a high-fat diet. Simultaneously, EMF exposure is performed. The effects of the EMF on hepatic lipid deposition and oxidative stress were investigated. Additionally, the AMPK and Nrf2 pathways were analysed to confirm whether they were activated by the EMF.ResultsExposure to EMF decreased the body weight, liver weight and serum triglyceride (TG) levels and restrained the excessive hepatic lipid accumulation caused by feeding the HFD. The EMF boosted CaMKKβ protein expression, activated AMPK phosphorylation and suppressed mature SREBP-1c protein expression. Meanwhile, the activity of GSH-Px was enhanced following an increase in nuclear Nrf2 protein expression by PEMF. However, no change was observed in the activities of SOD and CAT. Consequently, EMF reduced hepatic reactive oxygen species (ROS) and MDA levels, which means that EMF relieved liver damage caused by oxidative stress in HFD-fed mice.ConclusionsEMF may activate the CaMKKβ/AMPK/SREBP-1c and Nrf2 pathways to control hepatic lipid deposition and oxidative stress. This investigation indicates that EMF may be a novel therapeutic method for NAFLD.

TAF15 exacerbates nonalcoholic steatohepatitis progression by regulating lipid metabolism and inflammation via FASN and p65 NF-κB.

Nonalcoholic fatty liver disease (NAFLD) consists of a broad spectrum of conditions, and nonalcoholic steatohepatitis (NASH) is the advanced form of NAFLD. TAF15 is a DNA and RNA binding protein and is involved in crucial inflammatory signalling pathways. We aimed to investigate the role of TAF15 in the progression of NASH and the underlying molecular mechanism. We generated mice with hepatocyte-specific knockdown and overexpression of TAF15 using a specific adeno-associated virus (AAV). NASH models were established by feeding mice high-fat and high-cholesterol diets and methionine- and choline-deficient diets. Cleavage under targets and tagmentation and dual-luciferase reporter assays were performed to investigate the effect of TAF15 on FASN transcription. Coimmunoprecipitation and immunofluorescence assays were conducted to explore the interaction of TAF15 and p65. In vitro coculture systems were established to study the interactions of hepatocytes, macrophages and HSCs. TAF15 was significantly increased in the livers of mouse NASH models and primary hepatocyte NASH model. Knockdown of TAF15 inhibited steatosis, inflammation and fibrosis, while overexpression of TAF15 promoted NASH phenotypes. Mechanistically, TAF15 bound directly to the promoter region of FASN to facilitate its expression, thereby promoting steatosis. Moreover, TAF15 interacted with p65 and activated the NF-κB signalling pathway, increasing the secretion of proinflammatory cytokines and triggering M1 macrophage polarization. Treatment with the FASN inhibitor orlistat partially reversed the phenotypes. These results suggested that TAF15 exacerbated NASH progression by regulating lipid metabolism and inflammation via transcriptional activation of FASN and interacting with p65 to activate the NF-κB signalling pathway.

Diet-mediated constitutive induction of novel IL-4+ ILC2 cells maintains intestinal homeostasis in mice.

Group 2 innate lymphoid cells (ILC2s) expressing IL-5 and IL-13 are localized at various mucosal tissues and play critical roles in the induction of type 2 inflammation, response to helminth infection, and tissue repair. Here, we reveal a unique ILC2 subset in the mouse intestine that constitutively expresses IL-4 together with GATA3, ST2, KLRG1, IL-17RB, and IL-5. In this subset, IL-4 expression is regulated by mechanisms similar to but distinct from those observed in T cells and is partly affected by IL-25 signaling. Although the absence of the microbiota had marginal effects, feeding mice with a vitamin B1-deficient diet compromised the number of intestinal IL-4+ ILC2s. The decrease in the number of IL-4+ ILC2s caused by the vitamin B1 deficiency was accompanied by a reduction in IL-25-producing tuft cells. Our findings reveal that dietary vitamin B1 plays a critical role in maintaining interaction between tuft cells and IL-4+ ILC2s, a previously uncharacterized immune cell population that may contribute to maintaining intestinal homeostasis.

Isolation and identification of a novel toxin in scallop mantle tissue

Scallops are one of the main marine products of Hokkaido, Japan. In addition to adductor muscle, scallop mantle tissue is often consumed in Japan. Previously, we showed that feeding mice a diet containing 1% mantle tissue resulted in lower food consumption and, ultimately, death. In this study, we isolated and identified toxic substances from scallop mantle tissue. The isolated toxic substances were protein complexes with molecular weights of 18 kDa and 29 kDa. Feeding mice a diet containing 0.05% toxic substances led to their death at five weeks. Based on LC-MS/MS analysis, the 29-kDa and 18-kDa proteins were identified as an actin fragment and the N-terminal fragment of the gelsolin-like protein, respectively. The 18-kDa protein was expressed in the mantle, gill, and ovary but not in the adductor muscle, testis, or midgland. Toxicity was observed only in mouse tissues expressing the 18-kDa protein. Feeding mice a diet containing only the 18-kDa protein did not induce decreased food consumption or death, implying that both the 29-kDa and 18-kDa complexes are essential for toxicity. This is the first study to identify a novel toxin in scallop tissues.

Dysregulated Gln-Glu-α-ketoglutarate axis impairs maternal decidualization and increases the risk of recurrent spontaneous miscarriage

Recurrent spontaneous miscarriage (RSM) affects 1%-2% of fertile women worldwide and poses a risk of future pregnancy complications. Increasing evidence has indicated that defective endometrial stromal decidualization is a potential cause of RSM. Here, we perform liquid chromatography with mass spectrometry (LC-MS)-based metabolite profiling in human endometrial stromal cells (ESCs) and differentiated ESCs (DESCs) and find that accumulated α-ketoglutarate (αKG) derived from activated glutaminolysis contributes to maternal decidualization. Contrarily, ESCs obtained from patients with RSM show glutaminolysis blockade and aberrant decidualization. We further find that enhanced Gln-Glu-αKG flux decreases histone methylation and supports ATP production during decidualization. Invivo, feeding mice a Glu-free diet leads to a reduction of αKG, impaired decidualization, and an increase of fetal loss rate. Isotopic tracing approaches demonstrate Gln-dependent oxidative metabolism as a prevalent direction during decidualization. Our results demonstrate an essential prerequisite of Gln-Glu-αKG flux to regulate maternal decidualization, suggesting αKG supplementation as a putative strategy to rectify deficient decidualization in patients with RSM.

The dietary regulation of LEAP2 depends on meal composition in mice.

Ghrelin represents a key hormone regulating energy balance. Upon activation of the growth hormone secretagogue receptor (GHSR), ghrelin increases blood glucose levels, food intake, and promotes weight gain. The liver-expressed antimicrobial peptide 2 (LEAP2) acts as an endogenous antagonist of the GHSR. While the regulation of LEAP2 and its effect on the GHSR likely occur in an opposite pattern to that of ghrelin, the dietary regulation of LEAP2 remains to be described. We, therefore, examined the regulation of LEAP2 by different acute meal challenges (glucose, mixed meal, olive, lard, and fish oil) and diets (chow vs. high-fat) in C57BL/6 male mice. In addition, the effect of specific fatty acids (oleic, docosahexaenoic, and linoleic acid) on LEAP2 was assessed in murine intestinal organoids. While only mixed meal increased liver Leap2 expression, all meal challenges except fish oil increased jejunal Leap2 expression compared to water. Leap2 expression correlated with levels of hepatic glycogen and jejunal lipids. Lipid versus water dosing increased LEAP2 levels in the systemic circulation and portal vein where fish oil was associated with the smallest increase. In line with this, oleic acid, but not docosahexaenoic acid increased Leap2 expression in intestinal organoids. Feeding mice with high-fat versus chow diet not only increased plasma LEAP2 levels, but also the increment in plasma LEAP2 upon dosing with olive oil versus water. Taken together, these results show that LEAP2 is regulated by meal ingestion in both the small intestine and the liver according to the meal/diet of interest and local energy stores.

Feeding with resistant maltodextrin suppresses excessive calorie intake in a high-fat diet, mediated by changes in mouse gut microbiota composition, appetite-related gut hormone secretion, and neuropeptide transcriptional levels

Consuming resistant maltodextrin (RMD) decreases food intake and increase appetite-related gut hormones, but the underlying mechanisms have remained unknown. Therefore, we aimed to elucidate the mechanisms underlying the effects of RMD feeding on food intake (appetite) using Institute of Cancer Research male mice fed with a high-fat diet (HFD-cellulose group) or HFD in which cellulose was replaced with RMD (HFD-RMD group). Feeding mice with an HFD-RMD for approximately 8 weeks inhibited excessive calorie intake and altered the gut microbiota composition. Excessive calorie intake was inhibited for several days in mice fed only with an HFD-cellulose and transplanted with fecal microbiota from the HFD-RMD group (FMT-HFD-RMD group). Moreover, in the HFD-RMD and FMT-HFD-RMD groups, serum active glucagon-like peptide (GLP)-1 and peptide tyrosine tyrosine (PYY) levels were significantly higher, and appetite-related neuropeptide gene transcription in the hypothalamus were significantly altered, compared with the HFD-cellulose and FMT-HFD-cellulose groups. These results suggested that the long-term RMD intake changed the gut microbiota composition, increased the GLP-1 and PYY secretion, and altered the appetite-related neuropeptide gene transcription in the hypothalamus, leading to suppressed excessive calorie intake in an HFD.

Music-based interventions in the feeding environment on the gut microbiota of mice

Gut microbiota is established to be associated with the diversity of gastrointestinal conditions, but information on the variation associated with music and gut microbes is limited. Current study revealed the impacts of music intervention during feeding on the growth performance and gut microbes of mice by using clinical symptoms and 16S rRNA sequencing techniques. The results showed that feeding mice with music had a significant increase in body weight after the 25th day. The Firmicutes and Proteobacteria were the most dominant phylum in the gut microbiota. Also, the relative abundance of the dominant bacteria was variable after musical intervention. In contrast to the control group, a significant decrease in alpha diversity analysis of gut bacterial microorganisms and Metastats analysis showed a significant increase in the relative abundance of 5 genera and one phylum after the music intervention. Moreover, the musical intervention during feeding caused modifications in the gut microbial composition of mice, as evidenced by an increase in the level of Firmicutes and Lactobacillus, while decreases the richness of pathogenic bacteria, e.g. Proteobacteria, Cyanobacteria and Muribaculaceae, etc. In summary, music intervention increased body weight and enhanced the abundance of beneficial bacteria by reducing the prevalence of pathogenic bacteria in gut microbiota of mice.

Active Hexose Correlated Compound as a Countermeasure against Cold-induced Stress during Chlamydia muridarum Genital Infection in Mice.

Chronic stress is known to suppress the immune system, but the influence of stress on the pathogenesis of Chlamydia trachomatis genital infection and host immune response remains unexplored A stress mouse model has been developed in our lab and we have demonstrated that cold-induced stress (CIS) suppresses the immune system and subsequently leads to increased intensity of Chlamydia muridaum in mice. We have started feeding mice with Active hexose correlated compound (AHCC) that may restore the function of the immune system and result in reduced C. muridarum shedding from the genital tract. During the feeding of stressed mice with AHCC, dendritic cells (DCs) and macrophages bring the AHCC to T cells in the lymph node; however, the specific functions of DCs subsets in our stress model are not defined. We determined the production of cytokines by macrophages, CDs, and CD4+T in the AHCC-fed stress mice during C. muridarum genital infection. CD4+ T cells isolated from the spleen or lymph node of stressed-AHCC-fed, PBS-stressed, or non-stressed mice proliferated, and cytokine secretion was measured by ELISA. AHCC-feeding led to lower production of IL-5, IL-13, IL-10 and higher IL-12 (P<0.01) and IFN-

Analysis of the role of irisin receptor signaling in regulating osteogenic/adipogenic differentiation of bone marrow mesenchymal stem cells

ABSTRACT The study aimed to explore the role of the irisin receptor (integrin αVβ5) signaling pathway in obesity-induced osteoporosis and its potential mechanism. The integrin αVβ5 gene of bone marrow mesenchymal stem cells (BMSCs) was silenced and overexpressed, and the cells were exposed to irisin treatment and mechanical stretch. Mouse models of obesity were established by feeding mice a high-fat diet, and 8-week caloric restriction/aerobic exercise regimens were implemented. The results showed that after silencing the integrin αVβ5, the osteogenic differentiation of BMSCs was significantly reduced. While overexpression of the integrin αVβ5 increased the osteogenic differentiation of BMSCs. Besides, mechanical stretch promoted the osteogenic differentiation of BMSCs. Obesity did not affect integrin αVβ5 expression in the bone, but it downregulated the expression of irisin and osteogenic factors, upregulated the expression of adipogenic factors, increased bone marrow fat, reduced bone formation, and destroyed the bone microstructure. Caloric restriction, exercise, and a combined regimen reversed these effects and improved obesity-induced osteoporosis, with the combined treatment exhibiting the most potent effect. This study confirms that the irisin receptor signaling pathway has a significant part in transmitting ‘mechanical stress’ and regulating ‘osteogenic/adipogenic differentiation’ of BMSCs via recombinant irisin, mechanical stretch, and overexpression/silencing of the integrin αVβ5 gene.

Impact of dietary n-3 polyunsaturated fatty acid intake during the perinatal and post-weaning periods on the phospholipid and ganglioside composition of olfactory tissues.

The olfactory mucosa (OM) and olfactory bulb (OB) are neuronal tissues that contribute to the early processing of olfactory information. They contain significant amounts of n-3 and n-6 polyunsaturated fatty acids (PUFAs), which are crucial for neuronal tissue development. In this study, we evaluated the impact of feeding mice diets that are either deficient in α-linolenic acid (ALA) or supplemented with n-3 long-chain PUFAs from gestation to adolescence on the phospholipid and ganglioside composition of these tissues. Both diets modified the levels of some phospholipid classes, notably the phosphatidylserine and phosphatidylethanolamine levels. In addition, the low-ALA diet enriched n-6 PUFAs in the main phospholipid classes of both tissues, while the diet supplemented with n-3 PUFAs enhanced the n-3 PUFA-containing phospholipid species level, mainly in OM. The diets also modulated the levels and profiles of several ganglioside classes in OM and OB. These modifications may have repercussions on the olfactory sensitivity.

Screening, Identification, and Probiotic Properties of Bacillus Pumilus From Yak.

The yak has a unique physiological structure suited to life in anoxic and cold environments at high altitudes. The aim of this study was to isolate Bacillus species with good probiotic properties from yak feces. A series of tests were performed on the isolated Bacillus: 16S rRNA identification, antibacterial activity, tolerance to gastroenteric fluid, hydrophobicity, auto-aggregation, antibiotic sensitivity, growth performance, antioxidants, and immune indexes. A safe and harmless Bacillus pumilus DX24 strain with good survival rate, hydrophobicity, auto-aggregation, and antibacterial activity was identified in the yak feces. Feeding mice with Bacillus pumilus DX24 increased their daily weight gain, jejunal villus length, villi/Crypt ratio, blood IgG levels, and jejunum sIgA levels. This study confirmed the probiotic effects of Bacillus pumilus isolated from yak feces and provides the theoretical basis for the clinical application and development of new feed additives.

Uptake of the Plant Agriculture-Used Antibiotics Oxytetracycline and Streptomycin by Cherry Radish─Effect on Plant Microbiome and the Potential Health Risk.

Antibiotics are used to control certain bacterial diseases in plant agriculture. Understanding antibiotic uptake by edible vegetables after application and associated risks on plant microbiome and human health is critical. In this study, oxytetracycline and streptomycin, the two most commonly used antibiotics in plant agriculture, were applied to cherry radish via continuous soil drenching to study their translocations into plant tissues, influence on radish microbiome, and the potential health risk to mice. The results demonstrated that oxytetracycline induced hormesis in radish plants and both antibiotics were translocated into the leaves, fruits, and roots of radishes from the soil, with significantly higher plant uptake of streptomycin than oxytetracycline. Interestingly, the proportion of culturable oxytetracycline or streptomycin-resistant bacteria in the antibiotic-accumulated radish tissues was significantly higher than that in the antibiotic-free radish tissues, although both bacterial and fungal communities in different radish tissues were not affected by the accumulated antibiotics, demonstrating that antibiotic application could enrich antibiotic resistance in the plant microbiome. Feeding mice with antibiotics-accumulated radish tissues did not show significant effects on the weight and blood glucose levels of mice. Overall, this study provides important insights into the risk of using antibiotics in plant agriculture.

Long-term administration of Western diet induced metabolic syndrome in mice and causes cardiac microvascular dysfunction, cardiomyocyte mitochondrial damage, and cardiac remodeling involving caveolae and caveolin-1 expression

BackgroundLong-term consumption of an excessive fat and sucrose diet (Western diet, WD) has been considered a risk factor for metabolic syndrome (MS) and cardiovascular disease. Caveolae and caveolin-1 (CAV-1) proteins are involved in lipid transport and metabolism. However, studies investigating CAV-1 expression, cardiac remodeling, and dysfunction caused by MS, are limited. This study aimed to investigate the correlation between the expression of CAV-1 and abnormal lipid accumulation in the endothelium and myocardium in WD-induced MS, and the occurrence of myocardial microvascular endothelial cell dysfunction, myocardial mitochondrial remodeling, and damage effects on cardiac remodeling and cardiac function.MethodsWe employed a long-term (7 months) WD feeding mouse model to measure the effect of MS on caveolae/vesiculo-vacuolar organelle (VVO) formation, lipid deposition, and endothelial cell dysfunction in cardiac microvascular using a transmission electron microscopy (TEM) assay. CAV-1 and endothelial nitric oxide synthase (eNOS) expression and interaction were evaluated using real-time polymerase chain reaction, Western blot, and immunostaining. Cardiac mitochondrial shape transition and damage, mitochondria-associated endoplasmic reticulum membrane (MAM) disruption, cardiac function change, caspase-mediated apoptosis pathway activation, and cardiac remodeling were examined using TEM, echocardiography, immunohistochemistry, and Western blot assay.ResultsOur study demonstrated that long-term WD feeding caused obesity and MS in mice. In mice, MS increased caveolae and VVO formation in the microvascular system and enhanced CAV-1 and lipid droplet binding affinity. In addition, MS caused a significant decrease in eNOS expression, vascular endothelial cadherin, and β-catenin interactions in cardiac microvascular endothelial cells, accompanied by impaired vascular integrity. MS-induced endothelial dysfunction caused massive lipid accumulation in the cardiomyocytes, leading to MAM disruption, mitochondrial shape transition, and damage. MS promoted brain natriuretic peptide expression and activated the caspase-dependent apoptosis pathway, leading to cardiac dysfunction in mice.ConclusionMS resulted in cardiac dysfunction, remodeling by regulating caveolae and CAV-1 expression, and endothelial dysfunction. Lipid accumulation and lipotoxicity caused MAM disruption and mitochondrial remodeling in cardiomyocytes, leading to cardiomyocyte apoptosis and cardiac dysfunction and remodeling.

Short-term high fat feeding induces inflammatory responses of tuft cells and mucosal barrier cells in the murine stomach.

Feeding mice with a high fat diet (HFD) induces inflammation and results in changes of gene expression and cellular composition in various tissues throughout the body, including the gastrointestinal tract. In the stomach, tuft cells expressing the receptor GPR120 are capable of sensing saturated long chain fatty acids (LCFAs) and thus may be involved in initiating mechanisms of mucosal inflammation. In this study, we assessed which cell types may additionally be affected by high fat feeding and which candidate molecular mediators might contribute to mucosa-protective immune responses. A high fat dietary intervention for 3 weeks caused an expansion of tuft cells that was accompanied by a higher frequency of mucosal mast cells and surface mucous cells which are a known source of the insult-associated cytokine interleukin 33 (IL-33). Our data demonstrate that both brush and mucosal mast cells comprise the enzyme ALOX5 and its activating protein FLAP and thus have the capacity for synthesizing leukotriene (LT). In HFD mice, several tuft cells showed a perinuclear colocalization of ALOX5 with FLAP which is indicative of an active LT synthesis. Monitoring changes in the expression of genes encoding elements of LT synthesis and signaling revealed that transcript levels of the leukotriene C4 synthase, LTC4S, catalyzing the first step in the biosynthesis of cysteinyl (cys) LTs, and the cysLT receptors, cysLTR2 and cysLTR3, were upregulated in mice on HFD. These mice also showed an increased expression level of IL-33 receptors, the membrane-bound ST2L and soluble isoform sST2, as well as the mast cell-specific protease MCPT1. Based on these findings it is conceivable that upon sensing saturated LCFAs tuft cells may elicit inflammatory responses which result in the production of cysLTs and activation of surface mucous cells as well as mucosal mast cells regulating gastric mucosal function and integrity.