Inulin has been used as a prebiotic to alleviate glucose and lipid metabolism disorders in mice and humans by modulating the gut microbiota. However, the mechanism underlying the alleviation of metabolic disorders by inulin through interactions between the gut microbiota and host cells is unclear. We use ob/ob mice as a model to study the effect of inulin on the cecal microbiota by 16S rRNA gene amplicon sequencing and its interaction with host cells by transcriptomics. The inulin-supplemented diet improved glucose and lipid metabolism disorder parameters in ob/ob mice, alleviating fat accumulation and glucose intolerance. The α diversity of gut microbial community of ob/ob mice was reduced after inulin treatment, while the β diversity tended to return to the level of wild type mice. Interestingly, Prevotellaceae UCG 001 (family Prevotellaceae) was obviously enriched after inulin treatment. A comparative analysis of the gene expression profile showed that the cecal transcriptome was changed in leptin gene deficiency mice, whereas the inulin-supplemented diet partially reversed the changes in leptin gene-related signaling pathways, especially AMPK signaling pathway, where the levels of gene expression became comparable to those in wild type mice. Further analysis indicated that Prevotellaceae UCG 001 was positively correlated with the AMPK signaling pathway, which was negatively correlated with markers of glycolipid metabolism disorders. Our results suggest that the inulin-supplemented diet alleviates glucose and lipid metabolism disorders by partially restoring leptin related pathways mediated by gut microbiota.
AMP-Activated Protein Kinases ; metabolism ; Animals ; Cecum ; enzymology ; metabolism ; microbiology ; Gastrointestinal Microbiome ; drug effects ; Inulin ; therapeutic use ; Leptin ; genetics ; Male ; Metabolic Diseases ; drug therapy ; enzymology ; metabolism ; microbiology ; Mice ; Mice, Obese ; Prebiotics ; Signal Transduction ; drug effects ; Transcriptome

Because of their physiological similarity to humans, pigs provide an excellent model for the study of obesity. This study evaluated diet-induced adiposity in genetically lean pigs and found that body weight and energy intake did not differ between controls and pigs fed the high-fat (HF) diet for three months. However, fat mass percentage, adipocyte size, concentrations of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), insulin, and leptin in plasma were significantly higher in HF pigs than in controls. The HF diet increased the expression in backfat tissue of genes responsible for cholesterol synthesis such as Insig-1 and Insig-2. Lipid metabolism-related genes including sterol regulatory element binding protein 1c (SREBP-1c), fatty acid synthase 1 (FASN1), diacylglycerol O-acyltransferase 2 (DGAT2), and fatty acid binding protein 4 (FABP4) were significantly up-regulated in backfat tissue, while the expression of proliferator-activated receptor-α (PPAR-α) and carnitine palmitoyl transferase 2 (CPT2), both involved in fatty acid oxidation, was reduced. In liver tissue, HF feeding significantly elevated the expression of SREBP-1c, FASN1, DGAT2, and hepatocyte nuclear factor-4α (HNF-4α) mRNAs. Microarray analysis further showed that the HF diet had a significant effect on the expression of 576 genes. Among these, 108 genes were related to 21 pathways, with 20 genes involved in adiposity deposition and 26 related to immune response. Our results suggest that an HF diet can induce genetically lean pigs into obesity with body fat mass expansion and adipose-related inflammation.
Adipocytes/cytology* ; Adipogenesis/genetics* ; Adipose Tissue/metabolism* ; Adiposity ; Animals ; Body Weight ; Cholesterol/blood* ; Cholesterol, HDL/blood* ; Cholesterol, LDL/blood* ; Diet, High-Fat ; Inflammation/genetics* ; Insulin/blood* ; Leptin/blood* ; Lipid Metabolism ; Male ; Obesity/genetics* ; Random Allocation ; Swine ; Triglycerides/blood*

Obesity has become a severe public health problem across the world, and seriously affects the health and life quality of human beings. Here we generated lepr and mc4r mutant zebrafish via the CRISPR/Cas9 technique, and performed morphological and functional characterizations of those mutants. We observed that there was no significant phenotypic difference between homozygous mutants and wild-type controls before 2.5 months post-fertilization (mpf). However, the adult leprand mc4rindividuals displayed increased food intake, heavier weight, and higher body fat percentage, the characteristics of obesity phenotypes. Blood glucose test showed that overfeeding induced significantly impaired glucose tolerance in adult leprand mc4rzebrafish. Furthermore, we analyzed 76 energy metabolism-related transcripts in leprand mc4rzebrafish livers by using real-time RT-PCR, and compared the results with the published microarray data of Lepmouse livers, and found that the changes in the expression of insulin/IGF signaling (IIS) pathway genes in leprzebrafish and Lepmouse were positively correlated, suggesting that the IIS pathway maintains functional conservation between zebrafish and mammals during the evolution of the obesity-regulating molecule network.
Animals ; CRISPR-Cas Systems ; Gene Knockout Techniques ; Insulin ; metabolism ; Leptin ; Mutation ; Obesity ; genetics ; Receptor, Melanocortin, Type 4 ; genetics ; Receptors, Leptin ; genetics ; Signal Transduction ; Zebrafish ; Zebrafish Proteins ; genetics

OBJECTIVETo determine the changes in the expression of leptin and its receptor in the lungs of mice with varying degrees of asthma before and after budesonide treatment.

METHODSForty Balb/c mice were randomly assigned into 4 groups with 10 animals in each. One group received no treatment (control group) and the other groups were challenged with either nebulized ovalbumin (OVA) for three days (3-day group) or seven days (7-day group), or with nebulized ovalbumin followed by budesonide administration (treatment group). Changes in airway inflammation were observed using hematoxylin-eosin staining. The protein and mRNA levels of leptin and its receptor in lung tissues were determined using immunohistochemistry/Western blot and real-time PCR, respectively.

RESULTSThe two asthmatic groups showed more significant pathological changes in the airway than the control and the treatment groups. Mice that were challenged by OVA for seven days showed more marked pathological changes in the airway compared with mice challenged by OVA for three days. The protein and mRNA levels of leptin in the lung tissues of the 3-day group were significantly higher than those of the control group (P<0.01), but significantly lower than those of the 7-day group (P<0.01). The protein levels of leptin receptor in the lung tissues of the 3-day group were significantly lower than those of the control group (P<0.01). The treatment group showed increased protein levels of leptin receptor compared with the 7-day group (P<0.01). No significant difference was noted between the four groups with respect to the mRNA levels of leptin receptor in the lung tissues.

CONCLUSIONSLeptin is highly expressed whereas its receptor is lowly expressed in the lung tissues of asthmatic mice. Budesonide can increase the expression of leptin receptor, but has no significant impact on the expression of leptin.

Animals ; Asthma ; drug therapy ; metabolism ; pathology ; Blotting, Western ; Budesonide ; pharmacology ; Immunohistochemistry ; Leptin ; analysis ; genetics ; Lung ; chemistry ; pathology ; Male ; Mice ; Mice, Inbred BALB C ; RNA, Messenger ; analysis ; Receptors, Leptin ; analysis ; genetics

To study the expression and distribution of neuropeptide Y (NPY) and long leptin receptor (OB-Rb) in the gastrointestinal tract of giant panda, samples of three animals were collected from the key laboratory for reproduction and conservation genetics of endangered wildlife of Sichuan province, China conservation and research center for the giant panda. Paraffin sections of giant panda gastrointestinal tissue samples were observed using hematoxylin-eosin staining (HE) and strept actividin-biotin complex immunohistochemical staining (IHC). The results show that the intestinal histology of three pandas was normal and no pathological changes, and there were rich single-cell and multi-cell mucous glands, long intestinal villi and thick muscularis mucosa and muscle layer. Positive cells expressing NPY and OB-Rb were widely detected in the gastrointestinal tract by IHC methods. NPY positive nerve fibers and neuronal cell were widely distributed in submucosal plexus and myenteric plexus, especially in the former. They were arranged beaded or point-like shape. NPY positive cells were observed in the shape of ellipse and polygon and mainly located in the mucous layer and intestinal glands. OB-Rb positive cells were mainly distributed in the mucous layer and the laminae propria, especially the latter. These results confirmed that NPY and OB-Rb are widely distributed in the gut of the giant panda, which provide strong reference for the research between growth and development, digestion and absorption, and immune function.
Animals ; China ; Intestines ; metabolism ; Neuropeptide Y ; genetics ; metabolism ; Receptors, Leptin ; genetics ; metabolism ; Ursidae ; genetics ; metabolism

OBJECTIVETo investigate the effect of high-fat or high-glucose diet on obesity and visceral adipose tissue in C57BL/6 mice.

METHODSFour-week-old C57BL/6 mice were allocated into normal diet group,high-fat diet group,and high-glucose diet group according to the random number table until 20 weeks old. Body weight,epididymal adipose tissue weight,blood leptin,fat infiltration in liver,M1/M2 macrophage subtypes,and monocyte chemoattractant protein-1 mRNA in epididymal adipose tissues were measured.

RESULTSCompared with normal diet group,body weight,epididymal adipose tissue weight,and leptin concentration in high fat diet group at 20 weeks were significantly increased (P < 0.05),and oil red O staining showed more prominent adipocyte infiltration in liver in high-fat diet group than those in normal diet and high-glucose diet group. However,no apparent differences were seen in high-glucose diet group at 20 weeks in terms of body weight,epididymal adipose tissue weight and leptin concentration. In high-fat diet group,the macrophages infiltration in epididymal adipose tissue increased with time and the percentage of M2 macrophage decreased in high-fat diet group than that in high-glucose diet group(P<0.05). Compared with normal diet group,monocyte chemoattractant protein-1 mRNA expression increased significantly in high-fat diet group(P<0.05). In high-glucose group,however,no significant differences were discerned (P > 0.05).

CONCLUSIONHigh-fat diet,rather than 60% high glucose diet,will lead to obesity and macrophage infiltration in adipose tissues.

Adipocytes ; Adipose Tissue ; Animals ; Body Weight ; Chemokine CCL2 ; genetics ; metabolism ; Diet, High-Fat ; methods ; Glucose ; administration & dosage ; Intra-Abdominal Fat ; Leptin ; Macrophages ; Mice ; Mice, Inbred C57BL ; Obesity ; RNA, Messenger

Nonalcoholic steatohepatitis (NASH) is characterized by hepatocyte injury and inflammatory cell infiltration, which has been linked to peripheral insulin resistance and increased levels of triglycerides in the liver. The purposes of this study were to establish a mouse model of NASH by feeding mice a 60% high-fat diet (HFD) and to demonstrate the anti-fibrotic effects of oleuropein, which has been shown to have anti-oxidant and anti-inflammatory properties, in this HFD-induced mouse model of NASH. C57BL/6 mice were divided into three groups: a regular diet group (Chow), a HFD group and an oleuropein-supplemented HFD group (OSD), which was fed a 0.05% OSD for 6 months. The effects of oleuropein in this model were evaluated using biochemical, histological and molecular markers. The expression levels of alpha-smooth muscle actin (alpha-SMA)and collagen type I in the HFD and OSD groups were evaluated using real-time PCR and western blotting. The body weight, biochemical marker levels, nonalcoholic fatty liver disease activity score, homeostasis model of assessment-insulin resistance (HOMA-IR) and leptin levels observed in the HFD group at 9 and 12 months were higher than those observed in the Chow group. The HOMA-IR and leptin levels in the OSD group were decreased compared with the HFD group. In addition, alpha-SMA and collagen type I expression were decreased by oleuropein treatment. We established a NASH model induced by HFD and demonstrated that this model exhibits the histopathological features of NASH progressing to fibrosis. Our results suggest that oleuropein may be pharmacologically useful in preventing the progression of steatohepatitis and fibrosis and may be a promising agent for the treatment of NASH in humans.
Actins/genetics/metabolism ; Animals ; Antihypertensive Agents/*therapeutic use ; Collagen Type I/genetics/metabolism ; Diet, High-Fat/*adverse effects ; Fatty Liver/*drug therapy/etiology/metabolism ; Fibrosis/etiology/metabolism/prevention & control ; Iridoids/*therapeutic use ; Leptin/genetics/metabolism ; Liver/metabolism/pathology ; Mice ; Mice, Inbred C57BL

PURPOSE: To investigate the anti-apoptotic mechanism of leptin in non-small cell lung cancer. MATERIALS AND METHODS: The influences of leptin on apoptosis were investigated, analyzing the mechanism that triggers growth of A549 cells. The effects of leptin on cell proliferation were examined by XTT analysis. Leptin, C/EBP homologous protein (CHOP), phosphorylated-PKR-like ER kinase (p-Perk), inositol requiring proteins-1, spliced X-box transcription factor-1 (XBP1), cleaved activating transcription factor-6 (ATF6), eukaryotic translation initiation factor-2alpha, caspase-12 and CHOP protein were detected in four groups by western blot, and endoplasmic reticulum (ER) stress related mRNA were detected by reverse transcription PCR. RESULTS: The expression of leptin in A549 and leptin transfected cells inhibited cisplatin activated ER stress-associated mRNA transcription and protein activation. Two ER stress unfolded protein response pathways, PERK and ATF6, were involved, and XBP1 and tumor necrosis factor receptor-associated factor 2 (TRAF2) were increased significantly when treated with cisplatin in A549-siRNA against leptin cells. Furthermore, CHOP expression was inhibited upon leptin expression in A549, LPT-PeP and LPT-EX cells. CONCLUSION: Leptin serves as an important factor that promotes the growth of A549 cells through blocking ER stress-mediated pathways. This blocking is triggered by p-Perk and ATF6 via inhibition of CHOP expression.
Activating Transcription Factor 6/genetics/*metabolism ; Apoptosis/*drug effects/genetics ; Blotting, Western ; Cell Line, Tumor ; Cell Proliferation/*drug effects ; Humans ; Leptin/*pharmacology ; Reverse Transcriptase Polymerase Chain Reaction ; eIF-2 Kinase/*metabolism

3T3-L1 adipocytes express the B-cell-activating factor (BAFF) and three different BAFF receptors (BAFF-Rs). Furthermore, BAFF expression is regulated by inflammatory modulators, such as tumor necrosis factor-alpha and rosiglitazone. Here we investigated the function of BAFF in 3T3-L1 adipocytes and RAW 264.7 macrophages. We examined adipokine expression in 3T3-L1 adipocytes treated with 10 ng ml-1 BAFF. We also examined inflammatory molecule expression in RAW 264.7 macrophages treated with 10 or 100 ng ml-1 BAFF. We examined BAFF expression in the coculture of 3T3-L1 adipocytes and RAW 264.7 macrophages, as well as in white adipose tissue (WAT) of diet-induced obese (DIO) mice. We found that BAFF decreases leptin and adiponectin expression, but increases the expression of proinflammatory adipokines monocyte chemotactic protein-1, interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and haptoglobin. Coculturing the two cell types resulted in increased BAFF mRNA and protein expression, as well as modulation of BAFF-R mRNA expression in both cell types. These data indicate that BAFF might mediate adipocyte and macrophage interaction. When RAW 264.7 macrophages were treated with BAFF, BAFF-R expression was modulated as in coculture, and nitric oxide synthase and IL-6 expression increased. BAFF expression also increased in WAT of DIO mice. We propose that BAFF can regulate adipokine expression and possibly mediate adipocyte and macrophage interaction.
3T3-L1 Cells ; Adipocytes/drug effects/*metabolism ; Adipokines/genetics/*metabolism ; Adiponectin/genetics/metabolism ; Animals ; B-Cell Activating Factor/*metabolism/pharmacology ; Chemokine CCL2/genetics/metabolism ; Coculture Techniques ; Gene Expression Regulation/drug effects ; Haptoglobins/genetics/metabolism ; Inflammation Mediators/metabolism ; Interleukin-6/genetics/metabolism ; Leptin/genetics/metabolism ; Macrophages/drug effects/*metabolism ; Mice ; Mice, Inbred C57BL ; Mice, Obese ; RNA, Messenger/genetics/metabolism

BACKGROUNDThere is a significant association between obesity and breast cancer, which is possibly due to the expression of leptin. Therefore, it is important to clarify the role of leptin/ObR (leptin receptor) signaling during the progression of human breast cancer.

METHODSNude mice with xenografts of MCF-7 human breast cancer cells were administered recombinant human leptin subcutaneous via injection around the tumor site. Mice in the experimental group were intratumorally injected with ObR-RNAi-lentivirus, while negative control group mice were injected with the same dose of negative-lentivirus. Tumor size was blindly measured every other day, and mRNA and protein expression levels of ObR, estrogen receptor a (ERa), and vascular endothelial growth factor (VEGF) for each group were determined.

RESULTSKnockdown of ObR-treated xenografted nude mice with a high leptin microenvironment was successfully established. Local injection of ObR-RNAi-lentivirus significantly suppressed the established tumor growth in nude mice. ObR level was significantly lower in the experimental group than in the negative control group, while the amounts of ERa and VEGF expression were significantly lower in the leptin group than in the control group (P < 0.01 for all).

CONCLUSIONSInhibition of leptin/ObR signaling is essential to breast cancer proliferation and possible crosstalk between ObR and ERa, and VEGF, and may lead to novel therapeutic treatments aiming at targeting ObR in breast cancers.

Animals ; Breast Neoplasms ; genetics ; metabolism ; therapy ; Estrogen Receptor alpha ; genetics ; metabolism ; Female ; Humans ; Lentivirus ; genetics ; MCF-7 Cells ; Mice ; Mice, Nude ; RNA Interference ; physiology ; Receptors, Leptin ; genetics ; metabolism ; Vascular Endothelial Growth Factor A ; genetics ; metabolism ; Xenograft Model Antitumor Assays