Traditional Chinese Medicine-based Treatment in Cardiovascular Disease: Potential Mechanisms of Action.

Cardiovascular Disease (CVD) is the leading cause of morbidity and death worldwide and has become a global public health problem. Traditional Chinese medicine (TCM) has been used in China to treat CVD and achieved promising results. Therefore, TCM has aroused significant interest among pharmacologists and medical practitioners. Previous research showed that TCM can regulate the occurrence and development of atherosclerosis (AS), ischemic heart disease, heart failure, myocardial injury, and myocardial fibrosis by inhibiting vascular endothelial injury, inflammation, oxidant stress, ischemia-reperfusion injury, and myocardial remodeling. It is well-known that TCM has the characteristics of multi-component, multi-pathway, and multitarget. Here, we systematically review the bioactive components, pharmacological effects, and clinical application of TCM in preventing and treating CVD.

High-sulfated derivative of polysaccharide from Ulva pertusa improves Adriamycin-induced nephrotic syndrome by suppressing oxidative stress.

Nephrotic syndrome (NS) is characterized by proteinuria, hyperlipidemia, and hypoalbuminemia. Ulva pertusa, a green seaweed, is a nutritional supplement. In this study, the high-sulfated derivative of Ulva pertusa polysaccharide (HU) was prepared by combining U pertusa polysaccharide with chlorosulfonic acid. The NS rat model was established by tail vein single injection of Adriamycin (6.0 mg kg-1). Normal rats were used as the control group. NS rat models were treated with HU or U (173 mg kg-1 day-1). After treatment for 6 weeks, we assessed urine protein, renal function, and blood lipids, and observed morphology and histologic injury of the kidney and glomerular microstructure. Furthermore, we detected antioxidant enzyme activity and expression level of the Keap1/Nrf2 signaling pathway to explore the potential mechanism of HU. Results showed that HU not only alleviated hyperlipidemia and hypoalbuminemia, but also reduced urine protein by inhibiting podocyte detachment, thickening of the glomerular basement membrane, and expression of kidney fibrosis markers (collagens I and IV). In addition, HU enhanced antioxidant enzyme activity (GSH-Px, CAT, SOD) in both serum and the kidney, which may be due to upregulating the expression of Nrf2 and downregulating the expression of Keap1. In conclusion, HU appears to be effective in attenuating NS in rats through suppressing oxidative stress by regulating the Keap1/Nrf2 signaling pathway.

The gut signals to AGRP-expressing cells of the pituitary to control glucose homeostasis.

Glucose homeostasis can be improved after bariatric surgery, which alters bile flow and stimulates gut hormone secretion, particularly FGF15/19. FGFR1 expression in AGRP-expressing cells is required for bile acids' ability to improve glucose control. We show that the mouse Agrp gene has 3 promoter/enhancer regions that direct transcription of each of their own AGRP transcripts. One of these Agrp promoters/enhancers, Agrp-B, is regulated by bile acids. We generated an Agrp-B knockin FLP/knockout allele. AGRP-B-expressing cells are found in endocrine cells of the pars tuberalis and coexpress diacylglycerol lipase B - an endocannabinoid biosynthetic enzyme - distinct from pars tuberalis thyrotropes. AGRP-B expression is also found in the folliculostellate cells of the pituitary's anterior lobe. Mice without AGRP-B were protected from glucose intolerance induced by high-fat feeding but not from excess weight gain. Chemogenetic inhibition of AGRP-B cells improved glucose tolerance by enhancing glucose-stimulated insulin secretion. Inhibition of the AGRP-B cells also caused weight loss. The improved glucose tolerance and reduced body weight persisted up to 6 weeks after cessation of the DREADD-mediated inhibition, suggesting the presence of a biological switch for glucose homeostasis that is regulated by long-term stability of food availability.

Optogenetic stimulation of the liver-projecting melanocortinergic pathway promotes hepatic glucose production.

The central melanocortin system plays a fundamental role in the control of feeding and body weight. Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC) also regulate overall glucose homeostasis via insulin-dependent and -independent pathways. Here, we report that a subset of ARC POMC neurons innervate the liver via preganglionic parasympathetic acetylcholine (ACh) neurons in the dorsal motor nucleus of the vagus (DMV). Optogenetic stimulation of this liver-projecting melanocortinergic pathway elevates blood glucose levels that is associated with increased expression of hepatic gluconeogenic enzymes in female and male mice. Pharmacological blockade and knockdown of the melanocortin-4 receptor gene in the DMV abolish this stimulation-induced effect. Activation of melanocortin-4 receptors inhibits DMV cholinergic neurons and optogenetic inhibition of liver-projecting parasympathetic cholinergic fibers increases blood glucose levels. This elevated blood glucose is not due to altered pancreatic hormone release. Interestingly, insulin-induced hypoglycemia increases ARC POMC neuron activity. Hence, this liver-projecting melanocortinergic circuit that we identified may play a critical role in the counterregulatory response to hypoglycemia.

Inhibition of Kir2.1 channel-induced depolarization promotes cell biological activity and differentiation by modulating autophagy in late endothelial progenitor cells.

AIMS: Endothelial progenitor cells (EPCs) play a crucial role in postnatal angiogenesis and neovascularization. Inward rectifier potassium channel 2.1 (Kir2.1) have been identified in EPCs. However, the effect of Kir2.1 on EPC function is not known. Here, we try to establish the role of Kir2.1 channels in EPC function and to provide first insights into the mechanisms. METHODS AND RESULTS: We first observed that the expression of Kir2.1 gradually decreased with the differentiation of EPCs into ECs in gene and protein levels. Treatment with the Kir2.1-selective inhibitor ML133 or knockdown of Kir2.1 by shRNA triggered EPC depolarization and promoted EPC biological functions, such as migration, adhesion, angiogenesis and differentiation into ECs in vitro. Transplantation of ML133-treated or Kir2.1 knockdown EPCs facilitated re-endothelialization in the rat injured arterial segment and inhibited neointima formation in vivo. In parallel, ML133 significantly enhanced autophagy and autophagic flux. After suppression of autophagy by 3-methyladenine (3-MA), the effects of ML133 on in vitro function and in vivo endothelialization capacity of EPCs were significantly inhibited. Mechanistically, ML133-induced autophagy was mediated at least partly by increased the activity of reactive oxygen species (ROS) that likely through intracellular calcium. CONCLUSION: Our study indicates that blocking or knockdown Kir2.1 results in a moderate depolarization of EPCs, which directly participated in enhancing EPC functions both in vitro and in vivo. In the mean time, autophagy signaling pathway is, at least in part, involved in this process. It may provide a potential target for the treatment or prevention of vascular injury and disease.

Fucoxanthin Exerts Cytoprotective Effects against Hydrogen Peroxide-induced Oxidative Damage in L02 Cells.

Several previous studies have demonstrated the excellent antioxidant activity of fucoxanthin against oxidative stress which is closely related to the pathogenesis of liver diseases. The present work was to investigate whether fucoxanthin could protect human hepatic L02 cells against hydrogen peroxide- (H2O2-) induced oxidative damage. Its effects on H2O2-induced cell viability, lactate dehydrogenase (LDH) leakage, intracellular reduced glutathione, and reactive oxygen species (ROS) contents, along with mRNA and protein relative levels of the cytoprotective genes including Nrf2, HO-1, and NQO1, were investigated. The results showed that fucoxanthin could upregulate the mRNA and protein levels of the cytoprotective genes and promote the nuclear translocation of Nrf2, which could be inhibited by the PI3K inhibitor of LY294002. Pretreatment of fucoxanthin resulted in decreased LDH leakage and intracellular ROS content but enhanced intracellular reduced glutathione. Interestingly, pretreatment using fucoxanthin protected against the oxidative damage in a nonconcentration-dependent manner, with fucoxanthin of 5 µM demonstrating the optimal effects. The results suggest that fucoxanthin exerts cytoprotective effects against H2O2-induced oxidative damage in L02 cells, which may be through the PI3K-dependent activation of Nrf2 signaling.

Activation of temperature-sensitive TRPV1-like receptors in ARC POMC neurons reduces food intake.

Proopiomelanocortin (POMC) neurons in the arcuate nucleus of the hypothalamus (ARC) respond to numerous hormonal and neural signals, resulting in changes in food intake. Here, we demonstrate that ARC POMC neurons express capsaicin-sensitive transient receptor potential vanilloid 1 receptor (TRPV1)-like receptors. To show expression of TRPV1-like receptors in ARC POMC neurons, we use single-cell reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry, electrophysiology, TRPV1 knock-out (KO), and TRPV1-Cre knock-in mice. A small elevation of temperature in the physiological range is enough to depolarize ARC POMC neurons. This depolarization is blocked by the TRPV1 receptor antagonist and by Trpv1 gene knockdown. Capsaicin-induced activation reduces food intake that is abolished by a melanocortin receptor antagonist. To selectively stimulate TRPV1-like receptor-expressing ARC POMC neurons in the ARC, we generate an adeno-associated virus serotype 5 (AAV5) carrying a Cre-dependent channelrhodopsin-2 (ChR2)-enhanced yellow fluorescent protein (eYFP) expression cassette under the control of the two neuronal POMC enhancers (nPEs). Optogenetic stimulation of TRPV1-like receptor-expressing POMC neurons decreases food intake. Hypothalamic temperature is rapidly elevated and reaches to approximately 39 °C during treadmill running. This elevation is associated with a reduction in food intake. Knockdown of the Trpv1 gene exclusively in ARC POMC neurons blocks the feeding inhibition produced by increased hypothalamic temperature. Taken together, our findings identify a melanocortinergic circuit that links acute elevations in hypothalamic temperature with acute reductions in food intake.

Antioxidant activity of purified ulvan in hyperlipidemic mice.

Several studies have reported that ulvan from the alga Ulva pertusa (Chlorophyta) exhibits substantial antioxidant and antihyperlipidemic activities; however, which group of heteropolysaccharides play roles in these activities remains unknown. In this study, three purified ulvan (PU1, PU2 and PU3) have been obtained by DEAE-Sepharose fast-flow column. The antioxidant activity was detected via the model of hyperlipidemic Kunming mice, including malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in liver. PU3, which possessed the highest uronic acid content (24.09%) and sulfate content (23.99%) as well as the lowest average molecular weight (83,094 Da), exhibited the stronger antioxidant activity than other examples. It significantly decreased MDA (29.2%; P < 0.05), increased SOD (36.4%; P < 0.05) and CAT (43.6%; P < 0.05) compared with hyperlipidemia group. In conclusion, PU3 may be potential sources of natural antioxidant to protecting against the liver damage of oxidative stress induced by cholesterol-rich diet.

A gut-brain axis regulating glucose metabolism mediated by bile acids and competitive fibroblast growth factor actions at the hypothalamus.

OBJECTIVE: Bile acids have been implicated as important regulators of glucose metabolism via activation of FXR and GPBAR1. We have previously shown that FGF19 can modulate glucose handling by suppressing the activity of hypothalamic AGRP/NPY neurons. As bile acids stimulate the release of FGF19/FGF15 into the circulation, we pursued the potential of bile acids to improve glucose tolerance via a gut-brain axis involving FXR and FGF15/FGF19 within enterocytes and FGF receptors on hypothalamic AGRP/NPY neurons. METHODS: A 5-day gavage of taurocholic acid, mirroring our previous protocol of a 5-day FGF19 treatment, was performed. Oral glucose tolerance tests in mice with genetic manipulations of FGF signaling and melanocortin signaling were used to define a gut-brain axis responsive to bile acids. RESULTS: The taurocholic acid gavage led to increased serum concentrations of taurocholic acid as well as increases of FGF15 mRNA in the ileum and improved oral glucose tolerance in obese (ob/ob) mice. In contrast, lithocholic acid, an FXR antagonist but a potent agonist for GPBAR1, did not improve glucose tolerance. The positive response to taurocholic acid is dependent upon an intact melanocortinergic system as obese MC4R-null mice or ob/ob mice without AGRP did not show improvements in glucose tolerance after taurocholate gavage. We also tested the FGF receptor isoform necessary for the bile acid response, using AGRP:Fgfr1-/- and AGRP:Fgfr2-/- mice. While the absence of FGFR1 in AGRP/NPY neurons did not alter glucose tolerance after taurocholate gavage, manipulations of Fgfr2 caused bidirectional changes depending upon the experimental model. We hypothesized the existence of an endogenous hypothalamic FGF, most likely FGF17, that acted as a chronic activator of AGRP/NPY neurons. We developed two short peptides based on FGF8 and FGF17 that should antagonize FGF17 action. Both of these peptides improved glucose homeostasis after a 4-day course of central and peripheral injections. Significantly, daily average blood glucose from continuous glucose monitoring was reduced in all tested animals but glucose concentrations remained in the euglycemia range. CONCLUSIONS: We have defined a gut-brain axis that regulates glucose metabolism mediated by antagonistic fibroblast growth factors. From the intestine, bile acids stimulate FGF15 secretion, leading to activation of the FGF receptors in hypothalamic AGRP/NPY neurons. FGF receptor intracellular signaling subsequently silences AGRP/NPY neurons, leading to improvements of glucose tolerance that are likely mediated by the autonomic nervous system. Finally, short peptides that antagonize homodimeric FGF receptor signaling within the hypothalamus have beneficial effects on glucose homeostasis without inducing hypoglycemia. These peptides could provide a new mode of regulating glucose metabolism.

The role of IL-8/CXCR2 signaling in microcystin-LR triggered endothelial cell activation and increased vascular permeability.

Microcystins are a family of cyclic heptapeptide toxins naturally produced by freshwater cyanobacteria. Microcystin-LR (MCLR) is believed to be the most toxic and common one with various pathological effects on human and mammals. However, the effects of MCLR on endothelial cells and vascular homeostasis have been largely unknown. We explored the mRNA and protein expression changes of several pro-inflammatory mediators in human umbilical vein endothelial cells (HUVECs) and C57BC/6 mice exposed to MCLR. Tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), interleukin-6 (IL-6), especially interleukin-8 (IL-8) were remarkably upregulated both in endothelial cells and in serum. Increased endothelial permeability in vitro and chronic microvascular permeability in animals were also observed. Silencing the IL-8 gene with siRNA or blocking its cognate receptor, CXC-chemokine receptor type 2 (CXCR2), by a specific inhibitor efficiently prevented the MCLR induced leakage. These observations indicate a novel insight of inflammation triggered property of MCLR via IL-8/CXCR2 signaling, suggesting CXCR2 as a target molecule in protective strategy against the wide range pollution of microcystin.

mTORC1 in AGRP neurons integrates exteroceptive and interoceptive food-related cues in the modulation of adaptive energy expenditure in mice.

Energy dissipation through interscapular brown adipose tissue (iBAT) thermogenesis is an important contributor to adaptive energy expenditure. However, it remains unresolved how acute and chronic changes in energy availability are detected by the brain to adjust iBAT activity and maintain energy homeostasis. Here, we provide evidence that AGRP inhibitory tone to iBAT represents an energy-sparing circuit that integrates environmental food cues and internal signals of energy availability. We establish a role for the nutrient-sensing mTORC1 signaling pathway within AGRP neurons in the detection of environmental food cues and internal signals of energy availability, and in the bi-directional control of iBAT thermogenesis during nutrient deficiency and excess. Collectively, our findings provide insights into how mTORC1 signaling within AGRP neurons surveys energy availability to engage iBAT thermogenesis, and identify AGRP neurons as a neuronal substrate for the coordination of energy intake and adaptive expenditure under varying physiological and environmental contexts.

Preliminary detection of the anti­tumour activity of indoline­2,3­dione derivative DH­12a targeting aminopeptidase N.

Aminopeptidase N (APN) is important in tumour processes. The present study detected the anti­tumour activity of the novel APN inhibitor DH­12a, which is an indoline­2,3­dione derivative. In the present study, Bestatin, a clinical APN inhibitor was used as a positive control. The expression of APN in the ES-2 and 3AO cell lines were assessed using flow cytometry and the drug inhibition constants of DH­12a (Ki=13.15 µM) and Bestatin (Ki=16.57 µM) were assessed using a double reciprocal method of competitive inhibition. The in vitro effects of DH­12a on cell proliferation were assessed using a 3­(4,5­dimethyl­thiazol­2­yl)­2,5­diphenyl tetrazolium bromide assay on human cell lines of ES­2 (IC50=43.8 µM), A549 (inhibition rate=41.5% at 160 µM DH­12a), HL60 (inhibition rate=47.83% at 160 µM DH­12a) and 3AO (IC50=70.2 µM). The inhibition rates were consistently higher than those of Bestatin. The effects of DH­12a on cell migration (inhibition rates in ES­2 cells and 3AO cells were 56.4 and 76.5%, respectively at 15 µM) and invasion (inhibition rates in ES­2 cells and 3AO cells were 75.6 and 66.5%, respectively at 15 µM) were assessed using transwell plates. The in vivo effects of DH­12a on tumour proliferation and lung tumour metastasis were determined using an H22 xenograft mice model, where DH­12a was administered in combination with genotoxic 5­fluorouracil. The anti­tumour activities of DH­12a in vivo were also greater than those of Bestatin. In conclusion, the in vitro effects of DH­12a on tumour proliferation, migration and invasion were consistent with the in vivo effects. In addition, DH­12a exhibited greater anti­tumour properties compared with Bestatin.

F­actin cytoskeleton reorganization is associated with hepatic stellate cell activation.

The activation of hepatic stellate cells (HSCs) is involved in the development of hepatic fibrosis. Previous studies have indicated that the acquisition of certain properties by activated HSCs is highly dependent on the reorganization of the actin cytoskeleton. However, direct evidence showing that the reorganization of the actin cytoskeleton is responsible for HSC activation is lacking. The aim of the present study was to investigate the role of cytoskeletal reorganization during HSC activation and to clarify the underlying mechanism. HSC-T6 cells were treated either with the F-actin stabilizer jasplakinolide (Jas) or the depolymerizer cytochalasin D (Cyto D). The actin cytoskeleton was evaluated via assessment of stress fiber formation. Furthermore, the activation properties of HSCs, including proliferation, adhesion, migration and the expression of α-smooth muscle actin (α-SMA) and collagen 1, were investigated in vitro. The results showed that Jas and Cyto D affected the actin distribution in HSC-T6 cells. Treatment with Jas resulted in thick actin bundles and a patchy appearance in the cytoplasm in HSC-T6 cells. In parallel, polymerization of actin microfilaments induced by Jas upregulated the expression of α-SMA and collagen 1, and also enhanced the migration and adhesion properties of HSC-T6 cells. Furthermore, the activation of HSC-T6 cells induced by the reorganization of the actin cytoskeleton was associated with the p38 mitogen-activated protein kinase (p38 MAPK) pathway. In conclusion, the present study suggests that the reorganization of the F-actin cytoskeleton is associated with HSC activation and that the p38 MAPK pathway is involved in this process. The inhibition of F-actin reorganization may thus be a potential key factor or molecular target for the control of liver fibrosis or cirrhosis.

Subchronic toxicity study of ulvan from Ulva pertusa (Chlorophyta) in Wistar rats.

Ulvan extracted from Ulva pertusa (Chlorophyta) is a group of sulfated heteropolysaccharide, for simplicity, the sulfated polysaccharide is referred to as ulvan in this paper. To our knowledge, there is no detailed report investigating the toxicity of ulvan. In this study, the subchronic (6 months) toxicity of varying levels of ulvan extracted from U. pertusa was investigated in Wistar rats after oral administration. ALT, ALB, ALP, WBC, PLT, and liver relative organ weigh of female rats showed significantly difference at 3000 mg/kg body weight per day, compared with control group. On the other hand, TG, T-CHO concentrations of female rats (6 months) were significantly decreased at 600, 1200 and 3000 mg/kg body weight per day. This result proved that ulvan had antihyperlipidemic activity. Beside, ulvan showed anticoagulant activity in this study. Overall, our findings indicated that ulvan had affected specific hematology, serum biochemistry parameters and liver, and had great differences between males and females rats.

Agouti-related peptide plays a critical role in leptin's effects on female puberty and reproduction.

Deficient leptin signaling causes infertility via reduced activity of GnRH neurons, causing a hypogonadal state in both rodents and humans. Because GnRH neurons do not express leptin receptors, leptin's effect on GnRH neurons must be indirect. Neurons within the hypothalamic arcuate nucleus that coexpress AGRP and NPY are considered to be important intermediate neurons involved in leptin regulation of GnRH neurons. Previously, we reported that the absence of AGRP and haploinsufficiency of MC4R in leptin receptor mutant (Lepr(db/db)) females result in restoration of fertility and lactation despite the persistence of obesity and insulin resistance. The overarching hypothesis in the present study is that the absence or reduction of leptin's inhibition of AGRP/NPY neurons leads to suppression of GnRH release in cases of leptin signaling deficiency. Since TAC2 (NKB)-TAC3R signaling plays a role in puberty maturation and is modulated by metabolic status, the other aim of this study is to test whether TAC2/NKB neurons in ARC regulated by melanocortinergic signals herein affect leptin's action on puberty and reproduction. Our data showed that AGRP deficiency in Lepr(db/db) females restores normal timing of vaginal opening and estrous cycling, although uterine weight gain and mammary gland development are morphologically delayed. Nonetheless, Agrp(-/-) Lepr(db/db) females are fertile and sustain adequate nutrition of pups with lactation to weaning age. AGRP deficiency results in advanced vaginal opening in wild-type female mice. The postpubertal increase in hypothalamic TAC2 mRNA was not observed in Lepr(db/db) females, whereas AGRP deficiency restored it in Lepr(db/db) females. Additionally, MC4R activation with MTII induced FOS expression in TAC2 neurons, supporting the concept of melanocortinergic regulation of TAC2 neurons. These studies suggest that AGRP imposes an inhibitory effect on puberty and that TAC2 neurons may transmit melanocortinergic inhibition of GnRH neurons.

Identification of a loss-of-function mutation in Ube2l6 associated with obesity resistance.

We previously mapped a locus on BALB/c chromosome 2 associated with protection from leptin-deficiency-induced obesity. Here, we generated the corresponding congenic mouse strain by introgression of a segment of C57BL/6J chromosome 2 to the BALB/c background to confirm the genotype-phenotype associations. We found that the BALB/c alleles decreased fat mass expansion by limiting adipocyte hyperplasia and adipocyte hypertrophy. This was concomitant to an increase in adipocyte triglyceride lipase (ATGL)-mediated triglyceride breakdown and prolongation of ATGL half-life in adipose tissue. In addition, BALB/c alleles on chromosome 2 exerted a cell-autonomous role in restraining the adipogenic potential of preadipocytes. Within a 9.8-Mb critical interval, we identified a nonsynonymous coding single nucleotide polymorphism in the gene coding for the ubiquitin-conjugating enzyme E2L6 (Ube2l6, also known as Ubch8) and showed that the BALB/c allele of Ube2l6 is a hypomorph leading to the lack of UBE2L6 protein expression. Ube2l6 knockdown in 3T3-L1 adipocytes repressed adipogenesis. Thus, altered adipogenic potential caused by Ube2l6 knockdown is likely critically involved in BALB/c obesity resistance by inhibiting adipogenesis and reducing adipocyte numbers. Overall, we have identified a loss-of-function mutation in Ube2l6 that contributes to the chromosome 2 obesity quantitative trait locus.

TXNIP in Agrp neurons regulates adiposity, energy expenditure, and central leptin sensitivity.

Thioredoxin interacting protein (TXNIP) has recently been described as a key regulator of energy metabolism through pleiotropic actions that include nutrient sensing in the mediobasal hypothalamus (MBH). However, the role of TXNIP in neurochemically specific hypothalamic subpopulations and the circuits downstream from MBH TXNIP engaged to regulate energy homeostasis remain unexplored. To evaluate the metabolic role of TXNIP activity specifically within arcuate Agrp neurons, we generated Agrp-specific TXNIP gain-of-function and loss-of-function mouse models using Agrp-Ires-cre mice, TXNIP (flox/flox) mice, and a lentivector expressing the human TXNIP isoform conditionally in the presence of Cre recombinase. Overexpression of TXNIP in Agrp neurons predisposed to diet-induced obesity and adipose tissue storage by decreasing energy expenditure and spontaneous locomotion, without affecting food intake. Conversely, Agrp neuronal TXNIP deletion protected against diet-induced obesity and adipose tissue storage by increasing energy expenditure and spontaneous locomotion, also without affecting food intake. TXNIP overexpression in Agrp neurons did not primarily affect glycemic control, whereas deletion of TXNIP in Agrp neurons improved fasting glucose levels and glucose tolerance independently of its effects on body weight and adiposity. Bidirectional manipulation of TXNIP expression induced reciprocal changes in central leptin sensitivity and the neural regulation of lipolysis. Together, these results identify a critical role for TXNIP in Agrp neurons in mediating diet-induced obesity through the regulation of energy expenditure and adipose tissue metabolism, independently of food intake. They also reveal a previously unidentified role for Agrp neurons in the brain-adipose axis.

Genetic control of ATGL-mediated lipolysis modulates adipose triglyceride stores in leptin-deficient mice.

Dissecting the genetics of complex traits such as obesity allows the identification of causal genes for disease. Here, we show that the BALB/c mouse strain carries genetic variants that confer resistance to obesity induced by leptin-deficiency or a high-fat diet (HFD). We set out to identify the physiological and genetic bases underlying this phenotype. When compared with C57BL6/J ob/ob mice (B6), BALB/c ob/ob mice exhibited decreased food intake, increased thermogenic capacity, and improved fat catabolism, each of which can potentially modify obesity. Interestingly, analysis of F1 ob/ob (progeny of B6 ob/+ × BALB/c ob+) mice revealed that obesity resistance in BALB/c ob/ob mice principally relied upon improved fat mobilization. This was mechanistically explained by increased adipose triglyceride lipase (ATGL) content in adipocytes, along with increased lipolysis and fatty acid oxidation. We conducted a genome-wide scan and defined a quantitative trait locus (QTL) on chromosome 2. BALB/c alleles on chromosome 2 not only associated with the obesity resistance phenotype but also supported increased ATGL content in adipose tissue. In summary, our study provides evidence that leptin-independent control of adipocyte lipolysis rates directly modifies the balance of macronutrient handling and is sufficient to regulate fat mass in the absence of alterations in food intake and energy expenditure.-Marcelin, G., S-M. Liu, X. Li, G. J. Schwartz, and S. Chua.

[Detection and clinical significance of fetal specific mRNA from peripheral maternal blood].

OBJECTIVE: To investigate the methods and clinical significance of detecting PLAC4 and COL6A1 gene on fetal chromosome 21 from maternal peripheral blood. METHODS: From Oct. 2008 to Nov. 2009 30 normal pregnancies in Weifang People's Hospital were selected as pregnant group, and 9 non-pregnant women were selected as control group. Quantitative real-time PCR was used to determine transcript levels of the target genes (PLAC4 and COL6A1) in blood samples. Correlation between the expression level and gestational age was analyzed. RESULTS: (1) PLAC4 mRNA was detected in peripheral blood of all pregnant women. Its maximum level was 12.760×10(3) copies/ml, whereas the minimum was 2.105×10(3) copies/ml, and the average value is 6.612×10(3) copies/ml. In control group the PLAC4 mRNA could not be detected. There was statistically significant difference (P < 0.01) between the two groups. (2) COL6A1 mRNA is detected in pregnant group and control group, and the concentration was 6.847×10(3) copies/ml and 7.322×10(3) copies/ml respectively, with no statistically significant difference (P > 0.05). (3) Correlation analysis: there was no relationship between the level of PLAC4, COL6A1 mRNA and the gestational age, the correlation coefficients (r) were 0.29 and 0.31, and the P values were 0.121 and 0.168 respectively. CONCLUSIONS: COL6A1 mRNA can be detected in both pregnant group and control group, so it is not specific for pregnancy. PLAC4 mRNA can be detected only in pregnant women, so it has specificity in pregnancy and can be a discriminative marker gene for prenatal diagnosis of trisomy 21 fetuses.

Genotoxic evaluation of the GH transgenic Synechocystis using mice and turbot (Scophthalmus maximus L.).

In the present paper, the genotoxicity of transgenic Synechocystis sp. PCC 6803 containing flounder (Paralichthys olivaceus) growth hormone gene has been assessed using micronucleus tests in mice and fish. No micronucleus inductions in bone marrow erythrocyte of mice were observed at three doses of transgenic Synechocystis (2.0, 5.0, and 10.0g/kg). The frequencies of micronucleus and other nuclear abnormalities in turbot (Scophthalmus maximus L.) fed with 0.2%, 0.5% and 1.0% transgenic Synechocystis were also not significantly different (P>0.05) from controls. In contrast, cyclophosphamide, used in detecting the sensitivity of the biological assays, significantly increased the frequencies of micronucleus and other nuclear abnormalities in mice and turbot. Results indicate that the flounder GH transgenic Synechocystis sp. PCC 6803 seems to have no genotoxic effects on fish.