Thioredoxin reductase 3 suppression promotes colitis and carcinogenesis via activating pyroptosis and necrosis.

BACKGROUND: Txnrd3 as selenoprotein plays key roles in antioxidant process and sperm maturation. Inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease, are becoming significantly increasing disease worldwide in recent years which are proved relative to diet, especially selenium intake. METHODS: In the present study, 8-week-old C57BL/6N male Txnrd3-/-, Txnrd3-/ + , Txnrd3 + / + mice, weight 25-30 g, were randomly chosen and each group with 30 mice. Feed 3.5% DSS drinking water and normal water continuously for 7 days. Mouse colon cancer cells (CT26) were cultured in vitro to establish Txnrd3 overexpressed/knocked-down model by cell transfection technology. Morphology and ultrastructure, calcium levels, ROS level, cell death were observed and detected in vivo and vitro. RESULTS: In Txnrd3-/-mice, ulcerative colitis was more severe, the morphological and ultrastructural lesions were also more prominent compared with wild-type mice, accompanied by the significantly increased expression of NLRP3, Caspase1, RIPK3, and MLKL. Overexpression of Txnrd3 could lead to increased oxidative stress through intracellular calcium outflow-induced oxidative stress increase followed by necrosis and pyroptosis pathway activation and further inhibit the growth and proliferation of colon cancer cells. CONCLUSION: Txnrd3 overexpression leads to intracellular calcium outflow and increased ROS, which eventually leads to necrosis and focal death of colon cancer cells, while causing Txnrd3-/- mice depth of the crypt deeper, weakened intestinal secretion and immune function and aggravate the occurrence of ulcerative colitis. The present study lays a foundation for the prevention and treatment of ulcerative colitis and colon carcinoma in clinic treatment.

Loss of Nnt Increases Expression of Oxidative Phosphorylation Complexes in C57BL/6J Hearts.

Nicotinamide nucleotide transhydrogenase (NNT) is a proton pump in the inner mitochondrial membrane that generates reducing equivalents in the form of NAPDH, which can be used for anabolic pathways or to remove reactive oxygen species (ROS). A number of studies have linked NNT dysfunction to cardiomyopathies and increased risk of atherosclerosis; however, biallelic mutations in humans commonly cause a phenotype of adrenal insufficiency, with rare occurrences of cardiac dysfunction and testicular tumours. Here, we compare the transcriptomes of the hearts, adrenals and testes from three mouse models: the C57BL/6N, which expresses NNT; the C57BL/6J, which lacks NNT; and a third mouse, expressing the wild-type NNT sequence on the C57BL/6J background. We saw enrichment of oxidative phosphorylation genes in the C57BL/B6J in the heart and adrenal, possibly indicative of an evolved response in this substrain to loss of Nnt. However, differential gene expression was mainly driven by mouse background with some changes seen in all three tissues, perhaps reflecting underlying genetic differences between the C57BL/B6J and -6N substrains.

Genetic background influences expression and function of the cation channel TRPM4 in the mouse heart.

Transient receptor potential melastatin 4 (TRPM4) cation channels act in cardiomyocytes as a negative modulator of the L-type Ca2+ current. Ubiquitous Trpm4 deletion in mice leads to an increased ß-adrenergic inotropy in healthy mice as well as after myocardial infarction. In this study, we set out to investigate cardiac inotropy in mice with cardiomyocyte-specific Trpm4 deletion. The results guided us to investigate the relevance of TRPM4 for catecholamine-evoked Ca2+ signaling in cardiomyocytes and inotropy in vivo in TRPM4-deficient mouse models of different genetic background. Cardiac hemodynamics were investigated using pressure-volume analysis. Surprisingly, an increased ß-adrenergic inotropy was observed in global TRPM4-deficient mice on a 129SvJ genetic background, but the inotropic response was unaltered in mice with global and cardiomyocyte-specific TRPM4 deletion on the C57Bl/6N background. We found that the expression of TRPM4 proteins is about 78 ± 10% higher in wild-type mice on the 129SvJ versus C57Bl/6N background. In accordance with contractility measurements, our analysis of the intracellular Ca2+ transients revealed an increase in ISO-evoked Ca2+ rise in Trpm4-deficient cardiomyocytes of the 129SvJ strain, but not of the C57Bl/6N strain. No significant differences were observed between the two mouse strains in the expression of other regulators of cardiomyocyte Ca2+ homeostasis. We conclude that the relevance of TRPM4 for cardiac contractility depends on homeostatic TRPM4 expression levels or the genetic endowment in different mouse strains as well as on the health/disease status. Therefore, the concept of inhibiting TRPM4 channels to improve cardiac contractility needs to be carefully explored in specific strains and species and prospectively in different genetically diverse populations of patients.

Inbred Substrain Differences Influence Neuroimmune Response and Drinking Behavior.

BACKGROUND: The inbred mouse strain C57BL/6 is widely used in both models of addiction and immunological disease. However, there are pronounced phenotypic differences in ethanol (EtOH) consumption and innate immune response between C57BL/6 substrains. The focus of this study was to examine the effects of substrain on innate immune response and neuroimmune-induced escalation of voluntary EtOH consumption. The main goal was to identify whether substrain differences in immune response can account for differences in EtOH behavior. METHODS: We compared acute innate immune response with a viral dsRNA mimic, polyinosinic:polycytidylic acid (poly(I:C)), in brain using qRT-PCR in both C57BL/6N and C57BL/6J mice. Next, we used a neuroimmune model of escalation using poly(I:C) to compare drinking behavior between substrains. Finally, we compared brain neuroimmune response with both EtOH and repeated poly(I:C) in both substrains as a way to account for differences in EtOH behavior. RESULTS: We found that C57BL/6 substrains have differing immune response and drinking behaviors. C57BL/6N mice have a shorter but more robust inflammatory response to acute poly(I:C). In contrast, C57BL/6J mice have a smaller but longer-lasting acute immune response to poly(I:C). In our neuroimmune-induced escalation model, C57BL/6J mice but not C57BL/6N mice escalate EtOH intake after poly(I:C). Finally, only C57BL/6J mice show enhanced proinflammatory transcript abundance after poly(I:C) and EtOH, suggesting that longer-lasting immune responses are critical to neuroimmune drinking phenotypes. CONCLUSIONS: Altogether, this work has elucidated additional influences that substrain has on both innate immune response and drinking phenotypes. Our observations highlight the importance of considering and reporting the source and background used for production of transgenic and knockout mice. These data provide further evidence that genetic background must be carefully considered when investigating the role of neuroimmune signaling in EtOH abuse.

Hepatic transcriptomics analysis reveals that fructose intervention down-regulated xenobiotics-metabolising enzymes through aryl hydrocarbon receptor signalling suppression in C57BL/6N mice.

For decades, fructose intake has been recognised as an environmental risk for metabolic syndromes and diseases. Here we comprehensively examined the effects of fructose intake on mice liver transcriptomes. Fructose-supplemented water (34 %; w/v) was fed to both male and female C57BL/6N mice at their free will for 6 weeks, followed by hepatic transcriptomics analysis. Based on our criteria, differentially expressed genes (DEG) were selected and subjected to further computational analyses to predict key pathways and upstream regulator(s). Subsequently, predicted genes and pathways from the transcriptomics dataset were validated via quantitative RT-PCR analyses. As a result, we identified eighty-nine down-regulated and eighty-eight up-regulated mRNA in fructose-fed mice livers. These DEG were subjected to bioinformatics analysis tools in which DEG were mainly enriched in xenobiotic metabolic processes; further, in the Ingenuity Pathway Analysis software, it was suggested that the aryl hydrocarbon receptor (AhR) is an upstream regulator governing overall changes, while fructose suppresses the AhR signalling pathway. In our quantitative RT-PCR validation, we confirmed that fructose suppressed AhR signalling through modulating expressions of transcription factor (AhR nuclear translocator; Arnt) and upstream regulators (Ncor2, and Rb1). Altogether, we demonstrated that ad libitum fructose intake suppresses the canonical AhR signalling pathway in C57BL/6N mice liver. Based on our current observations, further studies are warranted, especially with regard to the effects of co-exposure to fructose on (1) other types of carcinogens and (2) inflammation-inducing agents (or even diets such as a high-fat diet), to find implications of fructose-induced AhR suppression.

ERG Alteration Due to the rd8 Mutation of the Crb1 Gene in Cln3 +/+ rd8-/rd8- Mice.

Mattapallil et al. described that vendor lines for C57BL/6 N mice may carry the rd8 mutation that leads to an ocular phenotype, which could be mistaken for an induced retinal degeneration. This mouse strain is widely used in ophthalmic research as a background for modeling retinal degeneration. In the process of studying Cln3Δex7/8 knock-in mice on a C57BL/6 N background, we became aware of this issue. The aim of this study thus was to use electroretinography to investigate the age-dependent functional loss in Cln3+/+ rd8-/rd8- mice and compare it to C57BL/6 J mice.The scotopic and photopic amplitudes of the a-wave and b-wave decrease significantly in mutant mice with increasing age, and the implicit time is prolonged. Especially the oscillatory potentials arising from inner retinal interaction seem to be notably affected by the rd8 mutation. Surprisingly, the amplitudes in young C57BL/6 J mice were lower than those measured in C57BL/6 N at any time point.Our results indicate that the rd8 mutation present in C57BL/6 N mice affects the function of the inner and outer retina. This is surprising given that the major retinal morphological alterations due to the rd8 mutation are found in the outer retina.We conclude that the rd8 mutation does affect the retinal function in Cln3+/+ rd8-/rd8- mice in a variable manner. Epigenetic factors and modifying genes lead to a phenotype shift in these mice. Interpreting the results of previous studies in mutant mice on C57BL/6 N background is challenging as comparing results obtained in independent studies or on other mouse backgrounds may be misleading. Using littermates as controls remains the only valid option.

Hair Growth Promoting Effect of 4HGF Encapsulated with PGA Nanoparticles (PGA-4HGF) by ß-Catenin Activation and Its Related Cell Cycle Molecules.

Poly-γ-glutamic acid (γ-PGA)-based nanoparticles draw remarkable attention as drug delivery agents due to their controlled release characteristics, low toxicity, and biocompatibility. 4HGF is an herbal mixture of Phellinus linteus grown on germinated brown rice, Cordyceps militaris grown on germinated soybeans, Polygonum multiflorum, Ficus carica, and Cocos nucifera oil. Here, we encapsulated 4HGF within PGA-based hydrogel nanoparticles, prepared by simple ionic gelation with chitosan, to facilitate its penetration into hair follicles (HFs). In this study, we report the hair promoting activity of 4HGF encapsulated with PGA nanoparticles (PGA-4HGF) and their mechanism, compared to 4HGF alone. The average size of spherical nanoparticles was ~400 nm in diameter. Continuous release of PGA-4HGF was observed in a simulated physiological condition. As expected, PGA-4HGF treatment increased hair length, induced earlier anagen initiation, and elongated the duration of the anagen phase in C57BL/6N mice, compared with free 4HGF treatment. PGA-4HGF significantly increased dermal papilla cell proliferation and induced cell cycle progression. PGA-4HGF also significantly increased the total amount of ß-catenin protein expression, a stimulator of the anagen phase, through induction of cyclinD1 and CDK4 protein levels, compared to free 4HGF treatment. Our findings underscore the potential of PGA nanocapsules to efficiently deliver 4HGF into HFs, hence promoting hair-growth. Therefore, PGA-4HGF nanoparticles may be promising therapeutic agents for hair growth disorders.

Changes in Monoamine Levels in BALB/c and 57Bl/6N Mice in Response to Acute Stress with Different Controllability.

The severity and specificity of CNS disturbances resulting from negative psychoemotional experience are determined by not only genetically determined stress sensitivity, but also epigenetic factors; among the latter, the context of stress exposure, e.g. stress controllability is considered. We examined the effect of controllability factor on behavioral and neurochemical parameters of acute stress in the elevated plus maze test. The situations of controllable and uncontrollable stress were modeled by allowing or restricting mice in their choice for closed arms during testing in the maze. The anxiety level of inbred BALB/c and C57Bl/6N mice was assessed and the levels and monoamine turnover in the medial prefrontal cortex, hippocampus, amygdala, and hypothalamus were measured. It was found that the decrease in stress controllability suppresses explorative activity in mice; the behavioral and neurochemical differences between the two strains are not constant feature and depend on stress controllability; serotoninergic and dopaminerigic neurotransmission in the hypothalamus can be a signal to discriminate stress controllability in the brain.

[Extracellular matrix collagen fiber structures of the gastrointestinal connective tissues in mice after a 30 day orbital flight].

The organs of the digestive system experience high sensitivity to the orbital flight factors and may limit the implementation of the professional activities of crews on International space station. The connective tissue as a system-forming matrix of the integrative and buffering metabolic environment has a particular importance in the space biomedicine because it provides the inner organ functionality in the conditions of changing level of the gravitational incentive. Aim - to study the adaptive mechanisms of the fibrous component of the extracellular matrix of the connective tissue of stomach and intestines on the effect of prolonged microgravity. MATERIAL AND METHODS: Using histochemical methods the condition of collagen fibers of a specific tissue microenvironment of the membranes of stomach and intestines of C57BL/6N mice (58 males with an initial body weight of 27.1±0.7 g) after a 30-day space flight and the following 7-day land readaptation was studied as well as in the animals representing corresponding control groups. RESULTS AND DISCUSSION: Laboratory animal presence on the biosatellite «BION-M¼ No. 1 has led to the fibrous reduction of extracellular matrix of connective tissue in the studied organs of digestive system structure except for the proper lamina of the gastric mucous membrane. Fibrillogenesis increase in the gastrointestinal tract in comparison with the indicators of space flight animal group has been found after 7 days of the biosatellite landing. The collagen fibers were not characterized by the significance change from the vivarium control group during the experiment with the land modelling of orbital flight conditions. CONCLUSION: The obtained results represent the evidence of fibrous structure gravity sensitivity of extracellular matrix of the connective tissue and show the relevance in the sphere of preventive measure improvement of the digestive system organs in the profession of astronauts in the orbital flight conditions.

Impact of serum as a dispersion agent for in vitro and in vivo toxicological assessments of TiO2 nanoparticles.

Nanoparticles (NP) have a tendency to agglomerate after dispersion in physiological media, which can be prevented by the addition of serum. This may however result in modification of the toxic potential of particles due to the formation of protein corona. Our study aimed to analyze the role of serum that is added to improve the dispersion of 10 nm TiO2 NPs on in vitro and in vivo effects following the exposure via the respiratory route. We characterized NP size, surface charge, sedimentation rate, the presence of protein corona and the oxidant-generating capacity after NP dispersion in the presence/absence of serum. The effect of serum on NP internalization, cytotoxicity and pro-inflammatory responses was assessed in a human pulmonary cell line, NCI-H292. Serum in the dispersion medium led to a slower sedimentation, but an enhanced cellular uptake of TiO2 NPs. Despite this greater uptake, the pro-inflammatory response in NCI-H292 cells was lower after serum supplementation (used either as a dispersant or as a cell culture additive), which may be due to a reduced intrinsic oxidative potential of TiO2 NPs. Interestingly, serum could be added 2 h after the NP treatment without affecting the pro-inflammatory response. We also determined the acute pulmonary and hepatic toxicity in vivo 24 h after intratracheal instillation of TiO2 NPs in C57BL/6N mice. The use of serum resulted in an underestimation of the local acute inflammatory response in the lung, while a systemic response on glutathione reduction remained unaffected. In conclusion, serum as a dispersion agent for TiO2 NPs can lead to an underestimation of the acute pro-inflammatory response in vitro and in vivo. To avoid potential unwanted effects of dispersants and medium components, we recommend that the protocol of NM preparation should be thoroughly tested, and reflect as close as possible realistic exposure conditions.

Comparative Studies on Behavioral, Cognitive and Biomolecular Profiling of ICR, C57BL/6 and Its Sub-Strains Suitable for Scopolamine-Induced Amnesic Models.

Cognitive impairment and behavioral disparities are the distinctive baseline features to investigate in most animal models of neurodegenerative disease. However, neuronal complications are multifactorial and demand a suitable animal model to investigate their underlying basal mechanisms. By contrast, the numerous existing neurodegenerative studies have utilized various animal strains, leading to factual disparity. Choosing an optimal mouse strain for preliminary assessment of neuronal complications is therefore imperative. In this study, we systematically compared the behavioral, cognitive, cholinergic, and inflammatory impairments of outbred ICR and inbred C57BL/6 mice strains subject to scopolamine-induced amnesia. We then extended this study to the sub-strains C57BL/6N and C57BL/6J, where in addition to the above-mentioned parameters, their endogenous antioxidant levels and cAMP response-element binding protein (CREB)/brain-derived neurotrophic factor (BDNF) protein expression were also evaluated. Compared with the ICR strain, the scopolamine-inflicted C57BL/6 strains exhibited a substantial reduction of spontaneous alternation and an approximately two-fold increase in inflammatory protein expression, compared to the control group. Among the sub-strains, scopolamine-treated C57BL/6N strains exhibited declined step-through latency, elevated acetylcholinesterase (AChE) activity and inflammatory protein expression, associated with reduced endogenous antioxidant levels and p-CREB/BDNF expression, compared to the control and tacrine-treated groups. This indicates that the C57BL/6N strains exhibit significantly enhanced scopolamine-induced neuronal impairment compared to the other evaluated strains.

Comparison of BALB/c and B6-albino mouse strain blastocysts as hosts for the injection of C57BL6/N-derived C2 embryonic stem cells.

Embryonic stem (ES) cells from a C57BL/6N (B6N) background injected into B6(Cg)-Tyrc-2J/J (B6-albino) recipient blastocysts are commonly used for generating genetically modified mouse models. To understand the influence of the recipient blastocyst strain on germline transmission, BALB/cAnNTac and B6-albino germline transmission rates were compared using the C57BL6/N-derived C2 ES cell line. A total of 92 ES cell clones from 27 constructs were injected. We compared blastocyst yield, birth rate, chimera formation rate, and high-percentage (>50 %) male chimera formation rate. For germline transmission, we analyzed 24 clones from 19 constructs, which generated high-percentage male chimeras from both donor strains. B6-albino hosts resulted in higher mean blastocyst yields per donor than did BALB/c ones (3.6 vs. 2.5). However, BALB/c hosts resulted in a higher birth rate than B6-albino ones (36 vs. 27 %), a higher chimera formation rate (50 vs. 42 %), a higher high-percentage male chimera rate (10 vs. 8 %), and a higher germline transmission rate (65 vs. 49 %), respectively. Our data suggest that BALB/c is a suitable blastocyst host strain for C2 ES cells and has an advantage over the B6-albino strain for receiving the injection of C2 ES cells.

Polr3b heterozygosity in mice induces both beneficial and deleterious effects on health during ageing with no effect on lifespan.

The genetic pathways that modulate ageing in multicellular organisms are typically highly conserved across wide evolutionary distances. Recently RNA polymerase III (Pol III) was shown to promote ageing in yeast, C. elegans and D. melanogaster. In this study we investigated the role of Pol III in mammalian ageing using C57BL/6N mice heterozygous for Pol III (Polr3b+/-). We identified sexually dimorphic, organ-specific beneficial as well as detrimental effects of the Polr3b+/- mutation on health. Female Polr3b+/- mice displayed improved bone health during ageing, but their ability to maintain an effective gut barrier function was compromised and they were susceptible to idiopathic dermatitis (ID). In contrast, male Polr3b+/- mice were lighter than wild-type (WT) males and had a significantly improved gut barrier function in old age. Several metabolic parameters were affected by both age and sex, but no genotype differences were detected. Neither male nor female Polr3b+/- mice were long-lived compared to WT controls. Overall, we find no evidence that a reduced Pol III activity extends mouse lifespan but we do find some potential organ- and sex-specific benefits for old-age health.

Genetic Upregulation of Activated Protein C Mitigates Delayed Effects of Acute Radiation Exposure in the Mouse Plasma.

Exposure to ionizing radiation, accidental or intentional, may lead to delayed effects of acute radiation exposure (DEARE) that manifest as injury to organ systems, including the kidney, heart, and brain. This study examines the role of activated protein C (APC), a known mitigator of radiation-induced early toxicity, in long-term plasma metabolite and lipid panels that may be associated with DEARE in APCHi mice. The APCHi mouse model used in the study was developed in a C57BL/6N background, expressing the D168F/N173K mouse analog of the hyper-activatable human D167F/D172K protein C variant. This modification enables increased circulating APC levels throughout the mouse's lifetime. Male and female cohorts of C57BL/6N wild-type and APCHi transgenic mice were exposed to 9.5 Gy γ-rays with their hind legs shielded to allow long-term survival that is necessary to monitor DEARE, and plasma was collected at 6 months for LC-MS-based metabolomics and lipidomics. We observed significant dyslipidemia, indicative of inflammatory phenotype, upon radiation exposure. Additionally, observance of several other metabolic dysregulations was suggestive of gut damage, perturbations in TriCarboxylic Acid (TCA) and urea cycles, and arginine metabolism. We also observed gender- and genotype-modulated metabolic perturbations post radiation exposure. The APCHi mice showed near-normal abundance for several lipids. Moreover, restoration of plasma levels of some metabolites, including amino acids, citric acid, and hypoxanthine, in APCHi mice is indicative of APC-mediated protection from radiation injuries. With the help of these findings, the role of APC in plasma molecular events after acute γ-radiation exposure in a gender-specific manner can be established for the first time.

CpG adjuvant enhances humoral and cellular immunity against OVA in different degrees in BALB/c, C57BL/6J, and C57BL/6N mice.

In lab settings, inbred mouse strains like BALB/c, C57BL/6J, and C57BL/6N are commonly used. Research in immunology and infectious diseases indicates that their Th1 and Th2 immune responses differ. However, the specific differences in the immune response to the vaccination still require investigation. In this study, ovalbumin (OVA) was used as an antigen and CpG-enriched recombinant plasmid (pUC18-CpG) as an adjuvant for immunisation. The level of serum-specific antibody IgG was detected by indirect ELISA. At 35dpi, serum cytokine levels were measured using MILLIPLEX®. T lymphocyte clusters from mouse spleen were examined using flow cytometry to investigate the immunological effects of the CPG-OVA vaccine on three different types of mice. The results showed that pUC18-CpG as an adjuvant could successfully enhance the immune response. BALB/c had the highest level of IgG antibody. In the OVA-only group, the CD4+/CD8+ ratio of the three types of mice was generally increased, and the BALB/c group had the highest ratio. After inoculation with CpG-OVA, the CD4+/CD8+ ratio of the three types of mice was lower than that of the OVA-only group, and C57BL/6J was the lowest. Compared with the CpG-OVA group of the three kinds of mice, the levels of Th2 cytokines IL-6 and IL-10 in BALB/c were increased compared with C57BL/6J and C57BL/6N. After OVA, the six cytokines secreted in C57BL/6J were higher than those in the C57BL/6N OVA group. Therefore, C57 is a better model for examining the function of the vaccine in cellular immunity, whereas BALB/c mice are more prone to humoral immunity. In addition to highlighting the CpG plasmid's ability to successfully activate the immune response of Th1 and Th2, as well as the expression of IgG in vivo and promote T cell immune typing, this study provides valuable insights into immunology and the selection of mouse models for infectious diseases, providing a valuable resource for designing more effective vaccines in the future.

Genetically engineered mouse model of HPV16 E6-E7 with vaginal-cervical intraepithelial neoplasia and decreased immunity.

Objective: To construct models of high-risk human papillomavirus (HPV) infection with precancerous lesions or cervical cancer and explore the immune function. Methods: Using CRISPR/Cas9, the expression vector HPV16-E6-E7-Rosa26 was microinjected into fertilized eggs of C57BL/6 N mice using homologous recombination, and the F0 generation was obtained for reproduction. Then, the formation of precancerous lesions was promoted via intramuscular injection of estradiol. Presence of precancerous cervical-vaginal intraepithelial lesions, Ki67 and p16 expression levels, and CD8+ T cell proportions in the spleen were evaluated. Results: Two F0 generation mice exhibited correct the homologous recombination. Seven positive mice were identified in the F1 generation. After breeding and mating, 25 homozygous and 11 heterozygous HPV16-E6-E7-engineered mice were obtained from the F2 generation. After estradiol benzoate treatment, the cervical-vaginal epithelium appeared as precancerous lesions with positive Ki67 and p16 expression. The percentage of CD8+ T cells decreased. Conclusion: HPV16-E6-E7-Rosa26 induced low immune function in mice, and provides a good model for the basic research of the mechanisms of action of HPV infection-associated precancerous lesions or cervical cancer.

Metabolic dysfunctions following chronic oral corticosterone are modified by adolescence and sex in mice.

Adolescence is a period of development in which shifts in responses to glucocorticoids is well-documented. Obesity and metabolic syndrome are substantial health issues whose rates continue to rise in both adult and adolescent populations. Though many interacting factors contribute to these dysfunctions, how these shifts in glucocorticoid responses may be related remain unknown. Using a model of oral corticosterone (CORT) exposure in male and female mice, we demonstrate differential responses during adolescence (30-58 days of age) or adulthood (70-98 day of age) in endpoints relevant to metabolic function. Our data indicate that CORT resulted in significant weight gain in adult- and adolescent-exposed females and adult-exposed males, but not adolescent-exposed males. Despite this difference, all animals treated with high levels of CORT showed significant increases in white adipose tissue, indicating a dissociation between weight gain and adiposity in adolescent-treated males. Similarly, all experimental groups showed significant increases in plasma insulin, leptin, and triglyceride levels, further suggesting potential disconnects between overt weight gain, and underlying metabolic dysregulation. Finally, we found age- and dose-dependent changes in the expression of hepatic genes important in glucocorticoid receptor and lipid regulation, which showed different patterns in males and females. Thus, altered transcriptional pathways in the liver might be contributing differentially to the similar metabolic phenotype observed among these experimental groups. We also show that despite little CORT-induced changes in the hypothalamic levels of orexin-A and NPY, we found that food and fluid intake were elevated in adolescent-treated males and females. These data indicate chronic exposure to elevated glucocorticoid levels results in metabolic dysfunction in both males and females, which can be further modulated by developmental stage.

Kaempferia parviflora rhizome extract exerts anti-obesity effect in high-fat diet-induced obese C57BL/6N mice.

Kaempferia parviflora (KP) rhizome, also called black ginger, has been used as a herbal medicine for many centuries. This current study was aimed at exploring whether KP rhizome extract (KPE) had anti-obesity effects and the mechanism involved. Five-week-old C57BL/6N male mice were allocated into five groups for 8-week feeding with control diet (CD), high-fat diet (HFD), HFD + 150 mg/kg body weight (BW)/day KPE (HFD+K150), HFD + 300 mg/kg BW/day KPE (HFD+K300), and HFD + 600 mg/kg BW/day KPE (HFD+K600). KPE decreased BW, body fat mass, adipose tissue weight, adipocyte size, and serum levels of glucose, triglycerides, cholesterol, insulin, and leptin in HFD-induced obese C57BL/6N mice. KPE inhibited adipogenesis by decreasing CCAAT/enhancer binding protein α, peroxisome proliferator-activated receptor γ, sterol regulatory element-binding protein-1c, acetyl-CoA carboxylase 1, ATP-citrate lyase, and fatty acid synthase mRNA expression. KPE improved lipolysis by increasing carnitine palmitoyl transferase 1 and hormone-sensitive lipase mRNA expression. These results suggest that KPE may have inhibited HFD-induced obesity by regulating several pathways involved in decreasing adipogenesis and enhancing lipolysis. Thus, the results suggest that KPE (or KP) may be applicable as an anti-obesity agent.

Effects of fruits and vegetables on gut microbiota in a mouse model of metabolic syndrome induced by high-fat diet.

The aim of this study was to evaluate the effect of fruit and vegetable intake on gut microbiota using a mouse model of metabolic syndrome (MS) induced by a high-fat diet. Forty-eight male mice were randomly divided into four groups, control group (C), high-fat diet-fed model group (H), high fat plus low intake of fruits and vegetables diet-fed group (H.LFV), high fat plus high intake of fruits and vegetables diet-fed group (H.HFV), and each group were fed for 60 days. During the experiment, mouse body weights were recorded and fecal samples were collected. Cetyltrimethyl ammonium bromide (CTAB) method was used to extract fecal bacterial DNA, and the purity and concentration of the DNA were detected by electrophoresis. DNA samples underwent PCR amplification (primers in 16 S V4 (515F and 806R)). Raw sequencing data were processed, and sample complexity and multiple-sample comparisons were investigated. Mouse organ coefficient, serum lipid levels, fecal TC (total cholesterol) and TBA (total bile acid) levels, and hepatic glutathione and malondialdehyde levels were determined. Compared to the H group, the fecal TC and TBA levels decreased significantly in the H.HFV group (p < .05), and hepatic glutathione and malondialdehyde levels decreased significantly in both H.LFV and H.HFV groups (p < .05). Decreased abundance of Firmicutes, Burkholderiales, Syntrophomonas, and Pseudomonadales in gut microbiota was observed in H.LFV and H.HFV groups compared to the H group. The Anosim results showed significant differences in pairwise comparison between groups. The linear discriminant analysis effect size (LEfSe) results showed that k_bacteria not only exhibited statistically differences between H and C groups but also among H.LFV, H.LFV, and H groups, and hence, could be used as a biomarker between groups. To sum up, fruit and vegetable powder could increase the fecal excretion of TC and TBA, and the antioxidant capacity in C57BL/6N mice. Meanwhile, the mechanism that fruit and vegetable powder could prevent MS in C57BL/6N mice was related to the decreased abundance of gut microbiota, including Firmicutes, Syntrophomonadales, and Pseudomonadales. Hence, fruit and vegetable powder could be used as a recommended food to regulate gut microbiota and prevent the occurrence of MS-related diseases.

C57BL/6J and C57BL/6N mice exhibit different neuro-behaviors and sensitivity to midazolam- and propofol-induced anesthesia.

Phenotypes of inbred mice are strain-dependent, indicating the important influence of genetic background in biomedical research. C57BL/6 is one of the most commonly used inbred mouse strains, and its two closely related substrains, C57BL/6J and C57BL/6N, have been separated for only about 70 years. These two substrains have accumulated genetic variations and exhibit different phenotypes, but it remains unclear whether they respond to anesthetics differently. In this study, commercially acquired wildtype C57BL/6J or C57BL/6N mice from two different sources were analyzed and compared for their response to a spectrum of anesthetics (midazolam, propofol, esketamine or isoflurane anesthesia) and their performance in a series of behavioral tests associated with neurological functions including open field test (OFT), elevated plus maze (EPM), Y maze, prepulse inhibition (PPI), tail strain test (TST) and forced swimming test (FST). Loss of the righting reflex (LORR) is used to measure the anesthetic effects. Our results suggested that the anesthesia induction time induced by either of the four anesthetics were comparable for the C57BL/6J and C57BL/6N mice. However, C57BL/6J or C57BL/6N mice do exhibit different sensitivity to midazolam and propofol. The anesthesia duration of midazolam of C57BL/6J mice was about 60% shorter than that of the C57BL/6N mice, while the LORR duration induced by propofol in C57BL/6J mice was 51% longer than that of the C57BL/6N. In comparison, the two substrains were anesthetized by esketamine or isoflurane similarly. In the behavioral analysis, the C57BL/6J mice exhibited a lower level of anxiety- and depression-like behaviors in OFT, EPM, FST and TST than the C57BL/6N mice. Locomotor activity and sensorimotor gating of these two substrains remained comparable. Our results stress the point that when selecting inbred mice for allele mutation or behavioral testing, the influence of even subtle differences in genetic background should be fully considered.