OBJECTIVE: In this study, the combined effect of two stressors, namely, electromagnetic fields (EMFs) from mobile phones and fructose consumption, on hypothalamic and hepatic master metabolic regulators of the AMPK/SIRT1-UCP2/FOXO1 pathway were elucidated to delineate the underlying molecular mechanisms of insulin resistance. METHODS: Weaned Wistar rats (28 days old) were divided into 4 groups: Normal, Exposure Only (ExpO), Fructose Only (FruO), and Exposure and Fructose (EF). Each group was provided standard laboratory chow ad libitum for 8 weeks . Additionally, the control groups, namely, the Normal and FruO groups, had unrestricted access to drinking water and fructose solution (15%), respectively. Furthermore, the respective treatment groups, namely, the ExpO and EF groups, received EMF exposure (1,760 MHz, 2 h/day x 8 weeks). In early adulthood, mitochondrial function, insulin receptor signaling, and oxidative stress signals in hypothalamic and hepatic tissues were assessed using western blotting and biochemical analysis. RESULT: In the hypothalamic tissue of EF, SIRT1, FOXO 1, p-PI3K, p-AKT, Complex III, UCP2, MnSOD, and catalase expressions and OXPHOS and GSH activities were significantly decreased ( P < 0.05) compared to the Normal, ExpO, and FruO groups. In hepatic tissue of EF, the p-AMPKα, SIRT1, FOXO1, IRS1, p-PI3K, Complex I, II, III, IV, V, UCP2, and MnSOD expressions and the activity of OXPHOS, SOD, catalase, and GSH were significantly reduced compared to the Normal group ( P < 0.05). CONCLUSION The findings suggest that the combination of EMF exposure and fructose consumption during childhood and adolescence in Wistar rats disrupts the closely interlinked and multi-regulated crosstalk of insulin receptor signals, mitochondrial OXPHOS, and the antioxidant defense system in the hypothalamus and liver.
Humans ; Rats ; Animals ; Adult ; Rats, Wistar ; Fructose/metabolism* ; Catalase ; Receptor, Insulin/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Electromagnetic Fields/adverse effects* ; Sirtuin 1/metabolism* ; Cell Phone ; Phosphatidylinositol 3-Kinases/metabolism* ; Forkhead Box Protein O1/metabolism* ; Uncoupling Protein 2

Mulberry (Morus alba L.) leaf is a well-established traditional Chinese botanical and culinary resource. It has found widespread application in the management of diabetes. The bioactive constituents of mulberry leaf, specifically mulberry leaf flavonoids (MLFs), exhibit pronounced potential in the amelioration of type 2 diabetes (T2D). This potential is attributed to their ability to safeguard pancreatic β cells, enhance insulin resistance, and inhibit α-glucosidase activity. Our antecedent research findings underscore the substantial therapeutic efficacy of MLFs in treating T2D. However, the precise mechanistic underpinnings of MLF's anti-T2D effects remain the subject of inquiry. Activation of brown/beige adipocytes is a novel and promising strategy for T2D treatment. In the present study, our primary objective was to elucidate the impact of MLFs on adipose tissue browning in db/db mice and 3T3-L1 cells and elucidate its underlying mechanism. The results manifested that MLFs reduced body weight and food intake, alleviated hepatic steatosis, improved insulin sensitivity, and increased lipolysis and thermogenesis in db/db mice. Moreover, MLFs activated brown adipose tissue (BAT) and induced the browning of inguinal white adipose tissue (IWAT) and 3T3-L1 adipocytes by increasing the expressions of brown adipocyte marker genes and proteins such as uncoupling protein 1 (UCP1) and beige adipocyte marker genes such as transmembrane protein 26 (Tmem26), thereby promoting mitochondrial biogenesis. Mechanistically, MLFs facilitated the activation of BAT and the induction of WAT browning to ameliorate T2D primarily through the activation of AMP-activated protein kinase (AMPK)/sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) signaling pathway. These findings highlight the unique capacity of MLF to counteract T2D by enhancing BAT activation and inducing browning of IWAT, thereby ameliorating glucose and lipid metabolism disorders. As such, MLFs emerge as a prospective and innovative browning agent for the treatment of T2D.
Mice ; Animals ; Adipose Tissue, Brown ; Sirtuin 1/pharmacology* ; Diabetes Mellitus, Type 2/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Morus/metabolism* ; Flavonoids/metabolism* ; Prospective Studies ; Signal Transduction ; Adipose Tissue, White ; Plant Leaves ; Uncoupling Protein 1/metabolism* ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism*

OBJECTIVE: To explore the protective effect and underlying mechanism of Lycium barbarum polysaccharides (LBP) in a non-alcoholic fatty liver disease (NAFLD) cell model. METHODS: Normal human hepatocyte LO2 cells were treated with 1 mmol/L free fatty acids (FFA) mixture for 24 h to induce NAFLD cell model. Cells were divided into 5 groups, including control, model, low-, medium- and high dose LBP (30,100 and 300 µg/mL) groups. The monosaccharide components of LBP were analyzed with high performance liquid chromatography. Effects of LBP on cell viability and intracellular lipid accumulation were assessed by cell counting Kit-8 assay and oil red O staining, respectively. Triglyceride (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), adenosine triphosphate (ATP) and oxidative stress indicators were evaluated. Energy balance and mitochondrial biogenesis related mRNA and proteins were determined by quantitative real-time polymerase chain reaction and Western blot, respectively. RESULTS: Heteropolysaccharides with mannose and glucose are the main components of LBP. LBP treatment significantly decreased intracellular lipid accumulation as well as TG, ALT, AST and malondialdehyde levels (P<0.05 or P<0.01), increased the levels of superoxide dismutase, phospholipid hydroperoxide glutathione peroxidase, catalase, and ATP in NAFLD cell model (P<0.05). Meanwhile, the expression of uncoupling protein 2 was down-regulated and peroxisome proliferator-activated receptor gamma coactivator-1α/nuclear respiratory factor 1/mitochondrial transcription factor A pathway was up-regulated (P<0.05). CONCLUSION LBP promotes mitochondrial biogenesis and improves energy balance in NAFLD cell model.
Humans ; Non-alcoholic Fatty Liver Disease/drug therapy* ; Lycium/metabolism* ; Catalase/metabolism* ; Organelle Biogenesis ; Alanine Transaminase ; Uncoupling Protein 2 ; Fatty Acids, Nonesterified ; Mannose ; Nuclear Respiratory Factor 1/metabolism* ; PPAR gamma/metabolism* ; Phospholipid Hydroperoxide Glutathione Peroxidase ; Drugs, Chinese Herbal/pharmacology* ; Malondialdehyde/metabolism* ; Superoxide Dismutase/metabolism* ; Polysaccharides/pharmacology* ; Triglycerides ; RNA, Messenger ; Aspartate Aminotransferases ; Glucose ; Adenosine Triphosphate

Fenofibrate, an agonist for peroxisome proliferator-activated receptor alpha (PPAR-α), lowers blood pressure, but whether this action is mediated via baroreflex afferents has not been elucidated. In this study, the distribution of PPAR-α and PPAR-γ was assessed in the nodose ganglion (NG) and the nucleus of the solitary tract (NTS). Hypertension induced by drinking high fructose (HFD) was reduced, along with complete restoration of impaired baroreceptor sensitivity, by chronic treatment with fenofibrate. The molecular data also showed that both PPAR-α and PPAR-γ were dramatically up-regulated in the NG and NTS of the HFD group. Expression of the downstream signaling molecule of PPAR-α, the mitochondrial uncoupling protein 2 (UCP2), was up-regulated in the baroreflex afferent pathway under similar experimental conditions, along with amelioration of reduced superoxide dismutase activity and increased superoxide in HFD rats. These results suggest that chronic treatment with fenofibrate plays a crucial role in the neural control of blood pressure by improving baroreflex afferent function due at least partially to PPAR-mediated up-regulation of UCP2 expression and reduction of oxidative stress.
Afferent Pathways ; drug effects ; Animals ; Antihypertensive Agents ; pharmacology ; Baroreflex ; drug effects ; Blood Pressure ; drug effects ; Fenofibrate ; pharmacology ; Male ; Oxidative Stress ; drug effects ; PPAR gamma ; drug effects ; metabolism ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects ; Transcriptional Activation ; drug effects ; Uncoupling Protein 2 ; drug effects ; metabolism ; Up-Regulation

OBJECTIVE: To investigate the effects of uncoupling protein 2 (UCP2) overexpression on mitochondrial dynamics (mitochondrial division and fusion) of sepsis myocardial injury in rats. METHODS: Forty male Sprague-Dawley (SD) rats were randomly divided into four groups (n = 10): sham operation group (Sham group) using normal saline instead of transfection and simulating cecal ligation and perforation (CLP); CLP group using normal saline instead of transfection, performing CLP to induce sepsis; adeno-associated virus (AAV) group using CLP after myocardial transfection with empty virus; UCP2 overexpression group (UCP2 group) CLP was performed 3 weeks after AAV-UCP2 (1×10¹⁵ vg/L, a total of 60 μL) myocardial transfection. The rats in each group were examined by echocardiography at 24 hours after the CLP, and then the rats were sacrificed immediately to harvest myocardial tissue. Myocardial ultrastructural changes were observed under the electron microscope, the expression of regulatory proteins related to myocardial mitochondrial dynamics [optic atrophy 1 (Opa1), dynamin-related protein 1 (Drp1) and fission 1 (Fis1)] were detected by Western Blot, and the level of mitochondrial adenosine triphosphate (ATP) production was detected by chemiluminescence. RESULTS: (1) The echocardiographic results showed that there was no significant difference in left ventricular mass (LVM) and stroke volume (SV). Compared with Sham group, left ventricular diastolic anterior wall thickness (LVAWd), left ventricular systolic anterior wall thickness (LVAWs), left ventricular diastolic posterior wall thickness (LVPWd), left ventricular systolic posterior wall thickness (LVPWs), left ventricular ejection fraction (LVEF) and left ventricular short axis shortening rate (LVFS) were significantly increased in CLP group and AAV group, while left ventricular systolic diameter (LVEDs), left ventricular diastolic diameter (LVEDd), left ventricular end-systolic volume (LVESV), and left ventricular end-diastolic volume (LVEDV) were significantly decreased. Compared with CLP group and AAV group, LVAWs, LVEF, LVFS were significantly decreased in UCP2 group, and LVEDs, LVEDV and LVESV were significantly increased [LVAWs (mm): 3.82±0.42 vs. 4.34±0.30, 4.44±0.12; LVEF: 0.921±0.038 vs. 0.979±0.019, 0.991±0.010; LVFS: (65.33±6.56)% vs. (80.11±8.23)%, (85.31±6.11)%; LVEDs (mm): 1.81±0.36 vs. 0.89±0.54, 0.60±0.17; LVEDV (μL): 137.09±50.05 vs. 89.72±53.04, 85.42±40.99; LVESV (μL): 10.48±4.59 vs. 2.48±3.52, 2.58±2.50, all P < 0.05]. (2) Electron microscope showed that the structure of myocardial fibers in the Sham group was clear and aligned with complete intervertebral disc and mitochondrial structure, no damage to mitochondrial membranes, and tight arrangement of cristae. In CLP group and AAV group, muscle fiber breakage, sarcoplasmic reticulum expansion, severe mitochondrial swelling and even cristage structure disorder were observed. In the UCP2 group, only myocardial fiber edema was observed, and the muscle fiber structure was more complete than that of Sham group and AAV group. The mitochondria were slightly swollen and the cristae were intact. (3) Western Blot showed that there was no significant difference in the expression of Opa1 and Fis1 in the four groups. The expression of Drp1 in CLP group and AAV group were significantly higher than that in Sham group. The expression of Drp1 in UCP2 group was significantly lower than that in CLP group and AAV group (Drp1/β-actin: 1.01±0.03 vs. 1.39±0.03, 1.49±0.03, both P < 0.05). (4) The results of immunofluorescence showed that the ATP content of CLP group and AAV group were significantly lower than that of Sham group; the ATP content of UCP2 group was significantly higher than that of CLP group and AAV group (μmol/L: 1.99±0.15 vs. 1.10±0.17, 1.13±0.19, both P < 0.05). CONCLUSIONS UCP2 overexpression can significantly improve the systemic systolic function of myocardium in sepsis rats, protect myocardial mitochondrial ultrastructure, inhibit mitochondrial division, and improve mitochondrial ATP synthesis.
Animals ; Male ; Mitochondria, Heart ; Mitochondrial Dynamics ; Myocardium ; Rats ; Rats, Sprague-Dawley ; Sepsis ; Uncoupling Protein 2/metabolism*

OBJECTIVETo explore the association between rs659366 polymorphisms and the outcomes of patients after surgery for colorectal cancer.

METHODSThe study was conducted among a cohort of 501 patients with primary colorectal cancer who had surgery in Sichuan Cancer Hospital during March 2010 and July 2013. The outcomes of the patients were followed up. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was applied to detect rs659366 genotypes. The log-rank test was performed to analyze the effects of clinical features on patients' outcomes. The correlation between rs659366 polymorphisms and the outcomes of patients was analyzed using the Cox proportional hazard model.

RESULTSIn this study, the median of follow-up time was 44.23(0.13-78.53)months, and 101 out of 501 (20.2%) patients failed to follow-up. The log-rank test showed the tumor site, TNM stage, vascular invasion, perineural invasion and the preoperative carcino-embryonic antigen(CEA) level were significantly associated with the outcome of colorectal cancer (<0.05 or <0.01). The overall survival rate of patients with AA, GA and GG genotypes were 62.7%, 69.9% and 75.5%, respectively. Multivariate analysis according to Cox proportional hazard model taking the GG genotype as the reference indicated that the AA genotype increased risks for survival of patients (=1.823); under the dominant genetic model taking GG genotype as reference, GA+AA genotypes increased risks for the poorer outcomes of patients (=1.498); the addictive genetic model showed that allele A increased the hazard for the poorer outcomes (=1.787).

CONCLUSIONSThe rs659366 polymorphisms are significantly associated with the outcome of patients with colorectal cancer.

Colorectal Neoplasms ; Genotype ; Humans ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Proportional Hazards Models ; Survival Rate ; Uncoupling Protein 2

OBJECTIVETo study the effect of total flavonoids of Astmgali Radix (TFA) on liver cirrhosis induced with dimethylnitrosamine (DMN) in rats, and the effect on peroxisome proliferator-activated receptor γ (PPARγ), uncoupling protein 2 (UCP2) and farnesoid X receptor (FXR).

METHODSFifty-three Sprague-Dawley rats were randomly divided into a control group (10 rats) and a DMN group (43 rats). Rats in the DMN group were given DMN for 4 weeks and divided randomly into a model group (14 rats), a low-dosage TFA group (14 rats) and a high-dosage TFA group (15 rats) in the 3rd week. Rats were given TFA for 4 weeks at the dosage of 15 and 30 mg/kg in the low- and high-TFA groups, respectively. At the end of the experiment blood and liver samples were collected. Serum liver function and liver tissue hydroxyproline content were determined. hematoxylin-eosin (HE), Sirus red and immunohistochemical stainings of collagen I, smooth muscle actin (α-SMA) was conducted in paraffinembedded liver tissue slices. Real time polymerase chain reaction (PCR) was adopted to determine PPARγ, UCP2 and FXR mRNA levels. Western blot was adopted to determine protein levels of collagen I, α-SMA, PPARγ, UCP2 and FXR.

RESULTSCompared with the model group, TFA increased the ratio of liver/body weight (low-TFA group P<0.05, high-TFA group P<0.01), improved liver biochemical indices (P<0.01 for ALT, AST, GGT in both groups, P<0.05 for albumin and TBil in the high-TFA group) and reduced liver tissue hydroxproline content (P<0.01 in both groups) in treatment groups significantly. HE staining showed that TFA alleviated liver pathological changes markedly and Sirus red staining showed that TFA reduced collagen deposition, alleviated formation and extent of liver pseudolobule. Collagen I and α-SMA immunohistochemical staining showed that staining area and extent markedly decreased in TFA groups compared with the model group. TFA could increase PPARγ, it regulated target UCP2, and FXR levels significantly compared with the model group (in the low-TFA group all P<0.05, in the high group all P<0.01).

CONCLUSIONTFA could improve liver function, alleviate liver pathological changes, and reduce collagen deposition and formation of liver pseudolobule in rats with liver cirrhosis. The antifibrotic effect of TFA was through regulating PPARγ signal pathway and the interaction with FXR.

Actins ; metabolism ; Animals ; Blotting, Western ; Body Weight ; drug effects ; Collagen Type I ; metabolism ; Dimethylnitrosamine ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Flavonoids ; pharmacology ; therapeutic use ; Hydroxyproline ; metabolism ; Liver ; drug effects ; pathology ; Liver Cirrhosis ; blood ; drug therapy ; genetics ; pathology ; Male ; Organ Size ; drug effects ; PPAR gamma ; genetics ; metabolism ; Plant Extracts ; pharmacology ; therapeutic use ; RNA, Messenger ; genetics ; metabolism ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction ; Receptors, Cytoplasmic and Nuclear ; genetics ; metabolism ; Uncoupling Protein 2 ; genetics ; metabolism

OBJECTIVETo investigate the expressions of inflammation- and fibrosis-related genes in perinephric and subcutaneous adipose tissues in patients with adrenocorticotropic hormone (ACTH)-independent Cushing's syndrome.

METHODSThe perinephric and subcutaneous adipose tissues adipose tissues were obtained from 8 patients with ACTH-independent Cushing's syndrome undergoing laparoscopic retroperitoneal adrenalectomy. Real-time PCR was used to detect the mRNA expression levels of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), matrix metallopeptidase 2 (MMP-2), TIMP metallopeptidase inhibitor 1 (TIMP-1), early growth response 1 (EGR1), CCAAT/enhancer binding protein β(CEBPβ), uncoupling protein 1(UCP-1), PPARγ coactivator 1 alpha (PGC1α) and cell death-inducing DFFA-like effector a (CIDEA).

RESULTSThe mRNA level of CIDEA was significantly higher in the perinephric adipose tissue (peri-N) than in the subcutaneous adipose tissue (subQ) (P<0.05). The expressions of CEBPβ, UCP-1, and PGC1α mRNA in the peri-N were similar with those in the subQ. The expressions of IL-6, TIMP1 and EGR1 mRNA in the subQ were significantly higher than those in the peri-N (P<0.05). No significant difference in TNF-α and MMP-2 mRNA levels was found between peri-N and subQ.

CONCLUSIONThe expression levels of the inflammation- and fibrosis-related genes are higher in the subQ than in the peri-N of patients with ACTH-independent Cushing's syndrome, suggesting that chronic exposure to endogenous hypercortisolism may cause adipose tissue dysfunction.

Adrenalectomy ; Adrenocorticotropic Hormone ; CCAAT-Enhancer-Binding Protein-beta ; metabolism ; Cushing Syndrome ; metabolism ; surgery ; Early Growth Response Protein 1 ; metabolism ; Humans ; Matrix Metalloproteinase 2 ; metabolism ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; metabolism ; Real-Time Polymerase Chain Reaction ; Subcutaneous Fat ; metabolism ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism ; Uncoupling Protein 1 ; metabolism

OBJECTIVETo investigate the correlation between uncoupling protein 2 (UCP2) expression and myocardial mitochondria injury in rats with sepsis induced by lipopolysaccharide (LPS).

METHODSThe rat model of sepsis was established through an intraperitoneal injection of LPS. Forty male Sprague-Dawley rats were randomly and equally divided into control group (an intraperitoneal injection of normal saline), sepsis 6 h group (LPS-6 h group), sepsis 12 h group (LPS-12 h group), sepsis 24 h group (LPS-24 h group), and sepsis 48 h group (LPS-48 h group). The serum and heart tissues were harvested at corresponding time points and myocardial mitochondria was extracted. The microplate reader was applied to measure creatine kinase (CK), creatine kinase-MB (CK-MB), and reactive oxygen species (ROS). Flow cytometry was applied to measure the degree of mitochondrial swelling and mitochondrial membrane potential (MMP). Western blot was used to measure the expression level of UCP2. Electron microscopy was applied to observe the morphological changes in heart tissues and myocardial mitochondria.

RESULTSCompared with the control group, the LPS groups had significantly increased serum levels of CK, CK-MB, and myocardial ROS, as well as a significantly increased degree of mitochondrial swelling (P<0.05), and these values reached their peaks at 24 hours after LPS injection. The LPS groups had a significant decrease in MMP (P<0.05), which reached the lowest level at 24 hours after LPS injection. Western blot showed that the LPS groups had a significant increase in the expression level of myocardial UCP2 compared with the control group (P<0.05), which reached its peak at 24 hours after LPS injection. The results of electron microscopy showed mitochondrial swelling, partial rupture of the mitochondrial membrane, and cavity formation in rats in the LPS groups. The most severe lesions occurred in the LPS-24 h group. In rats with LPS, the ROS level in the myocardial mitochondria and the degree of mitochondrial swelling were positively correlated with the expression level of UCP2 (r=0.796 and 0.893, respectively; P<0.05), while MMP was negatively correlated with the expression level of UCP2 (r=-0.903, P<0.05).

CONCLUSIONSIn the rat model of sepsis, the myocardium and myocardial mitochondria have obvious injuries, and the expression level of UCP2 is closely correlated with mitochondrial injury. Therefore, UCP2 might play an important role in myocardial mitochondrial injury in sepsis.

Animals ; Cardiomyopathies ; genetics ; metabolism ; Disease Models, Animal ; Humans ; Ion Channels ; genetics ; metabolism ; Lipopolysaccharides ; adverse effects ; Male ; Mitochondria, Heart ; metabolism ; Mitochondrial Proteins ; genetics ; metabolism ; Myocardium ; metabolism ; Rats ; Rats, Sprague-Dawley ; Sepsis ; genetics ; metabolism ; Uncoupling Protein 2

OBJECTIVETo explore whether the inhibitory effect of Genipin on uncoupling protein-2 (UCP-2) in mitochondria is involved in energy metabolism of androgen-independent PC3 prostate cancer cells.

METHODSPC3 prostate cancer cells were cultured and treated with Genipin at the concentrations of 40, 80, and 160 μmol/L for 48 hours. Then the proliferation of the cells was detected by MTT assay, the expression of UCP-2 mRNA determined by RT-PCR, and the content of intracellular pyruvic acid (PA) and the activity of succinate dehydrogenase (SDH) in the mitochondria measured by visible spectrophotometry.

RESULTSWith the increased concentration of Genipin, the proliferative activity of the PC-3 cells, the expression level of UCP-2 mRNA, the content of intracellular PA and the activity of SDH in the cells were all decreased, namely, with the enhanced inhibitory effect of Genipin on UCP-2, a trend of reduction was observed in the proliferation of the cells, intracellular PA content, and SDH activity in the mitochondria.

CONCLUSIONGenipin is involved in the energy metabolism of androgen-independent PC3 prostate cancer cells by reducing the content of intracellular PA and the activity of SDH in the mitochondria, which may be associated with its inhibitory effect on UCP-2.

Cell Line, Tumor ; drug effects ; Energy Metabolism ; Humans ; Ion Channels ; metabolism ; Iridoids ; pharmacology ; Male ; Mitochondria ; metabolism ; Mitochondrial Proteins ; metabolism ; Prostatic Neoplasms ; metabolism ; Pyruvic Acid ; metabolism ; RNA, Messenger ; Succinate Dehydrogenase ; metabolism ; Uncoupling Protein 2