Deficiency of neuropeptide Y attenuates neointima formation after vascular injury in mice.

BACKGROUND: Restenosis after percutaneous coronary intervention (PCI) limits therapeutic revascularization. Neuropeptide Y (NPY), co-stored and co-released with the sympathetic nervous system, is involved in this process, but its exact role and underlying mechanisms remain to be fully understood. This study aimed to investigate the role of NPY in neointima formation after vascular injury. METHODS: Using the left carotid arteries of wild-type (WT, NPY-intact) and NPY-deficient (NPY-/-) mice, ferric chloride-mediated carotid artery injury induced neointima formation. Three weeks after injury, the left injured carotid artery and contralateral uninjured carotid artery were collected for histological analysis and immunohistochemical staining. RT-qPCR was used to detect the mRNA expression of several key inflammatory markers and cell adhesion molecules in vascular samples. Raw264.7 cells were treated with NPY, lipopolysaccharide (LPS), and lipopolysaccharide-free, respectively, and RT-qPCR was used to detect the expression of these inflammatory mediators. RESULTS: Compared with WT mice, NPY-/- mice had significantly reduced neointimal formation three weeks after injury. Mechanistically, immunohistochemical analysis showed there were fewer macrophages and more vascular smooth muscle cells in the neointima of NPY-/- mice. Moreover, the mRNA expression of key inflammatory markers such as interleukin-6 (IL-6), transforming growth factor-ß1 (TGF-ß1), and intercellular adhesion molecule-1 (ICAM-1) was significantly lower in the injured carotid arteries of NPY-/- mice, compared to that in the injured carotid arteries of WT mice. In RAW264.7 macrophages, NPY significantly promoted TGF-ß1 mRNA expression under unactivated but not LPS-stimulated condition. CONCLUSIONS: Deletion of NPY attenuated neointima formation after artery injury, at least partly, through reducing the local inflammatory response, suggesting that NPY pathway may provide new insights into the mechanism of restenosis.

Arcuate NPY is involved in salt-induced hypertension via modulation of paraventricular vasopressin and brain-derived neurotrophic factor.

Chronic high salt intake is one of the leading causes of hypertension. Salt activates the release of the key neurotransmitters in the hypothalamus such as vasopressin to increase blood pressure, and neuropepetide Y (NPY) has been implicated in the modulation of vasopressin levels. NPY in the hypothalamic arcuate nucleus (Arc) is best known for its control in appetite and energy homeostasis, but it is unclear whether it is also involved in the development of salt-induced hypertension. Here, we demonstrate that wild-type mice given 2% NaCl salt water for 8 weeks developed hypertension which was associated with marked downregulation of NPY expression in the hypothalamic Arc as demonstrated in NPY-GFP reporter mice as well as by in situ hybridization analysis. Furthermore, salt intake activates neurons in the hypothalamic paraventricular nucleus (PVN) where mRNA expression of brain-derived neurotrophic factor (BDNF) and vasopressin was found to be upregulated, leading to elevated serum vasopressin levels. This finding suggests an inverse correlation between the Arc NPY level and expression of vasopressin and BDNF in the PVN. Specific restoration of NPY by injecting AAV-Cre recombinase into the Arc only of the NPY-targeted mutant mice carrying a loxP-flanked STOP cassette reversed effects of salt intake on vasopressin and BDNF expression, leading to a normalization of salt-dependent blood pressure. In summary, our study uncovers an important Arc NPY-originated neuronal circuitry that could sense and respond to peripheral electrolyte signals and thereby regulate hypertension via vasopressin and BDNF in the PVN.

"One-stop shop": safety and efficacy of combining atrial septal defect occlusion and left atrial appendage closure for patients with atrial septal defect and atrial fibrillation.

BACKGROUND: One-stop occlusion, which is defined as the combination of atrial septal defect [ASD] or patent foramen ovale [PFO] occlusion and left atrial appendage [LAA] closure, in patients with ASD/PFO and atrial fibrillation (AF) has not yet been investigated systematically. This study aimed to evaluate the safety and efficacy of one-stop occlusion in the treatment of adult patients with ASD/PFO and AF. METHODS: Inpatients with AF and ASD/PFO were recruited between August 2014 and April 2019. Preoperatively, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were conducted to identify the ASD/PFO size and margin, presence of thrombus in the LAA, and LAA orifice width and depth at 0°, 45°, 90°, and 135°. After confirmation of the indications of LAA closure (LAAC) and ASD/PFO occlusion, the procedures were performed simultaneously under general anesthesia. Oral anticoagulants were administered for 45-60 days, followed with regular evaluation of TTE and TEE. RESULTS: Forty-nine patients (age, 65.6 ± 9.6 years) were recruited in this study, including 24 patients with ASD and 25 patients with PFO. They were treated with LAAC and ASD/PFO occlusion successfully. The mean ASD size and mean diameter of the ASD occluders were 14.2 ± 7.7 and 25.4 ± 8.5 mm, respectively. The mean PFO size was 3.5 ± 0.4 mm. The mean maximal LAA orifice width and depth were 20.5 ± 3.4 and 28.3 ± 3.6 mm, respectively. All patients were implanted with a Watchman device (diameter, 27.1 ± 2.9 mm). Postoperatively, all patients took anticoagulants orally for 45-60 days, and their mean postoperative follow-up duration was 29.0 ± 12.1 months. Postoperative TEE showed that all had normal positioning of the LAA and ASD/PFO occluders. At 45-60 days after operation, TEE showed that the LAA and ASD/PFO occluder were in the normal position; however, two patients who took warfarin and novel oral anticoagulants, respectively, have developed occluder thrombosis. After adjusted anticoagulant therapy, TEE showed that the thrombus disappeared at 6 months after operation. CONCLUSION: One-stop occlusion is safe and effective for the treatment of adult patients with ASD/PFO and AF. It is also feasible to administer warfarin or novel oral anticoagulants after operation.

Nifedipine inhibits ox-LDL-induced lipid accumulation in human blood-derived macrophages.

Studies have shown that nifedipine, an anti-hypertensive drug, protects against atherosclerotic progression, but the underlying mechanisms remain elusive. Oxidized low-density lipoprotein (ox-LDL) is critically implicated in macrophage lipid deposition seen in atherosclerosis. In this study, we examined the effects of nifedipine on some ox-LDL-associated changes in human blood-derived macrophages. We isolated monocytes from normal human blood and differentiated them into macrophages. We then treated these human macrophages with ox-LDL and/or nifedipine, and examined lipid accumulation and expression levels of two scavenge receptors CD36 and SR-A as well as a protein kinase PKC-θ. Nifedipine treatment substantially reduced lipid accumulation and the expression of CD36, SR-A, and protein kinase C (PKC)-θ in human macrophages treated with ox-LDL. Silencing of PKC-θ using siRNA also reduced the expression of CD36 and SR-A in these cells. Our results thus suggest that nifedipine may inhibit atherosclerosis by reducing ox-LDL-induced lipid deposition through suppression of the CD36/SR-A-mediated uptake of ox-LDL by macrophages via a PKC-θ-dependent mechanism.

Clinical efficacy and safety of transcatheter closure of ruptured sinus of valsalva aneurysm.

OBJECTIVES: To evaluate the clinical efficacy and safety of transcatheter closure (TCC) in patients with ruptured sinus of Valsalva aneurysm (RSVA). BACKGROUND: RSVA is a rare cardiovascular disease with a varied clinical presentation. The clinical efficacy and safety of TCC for RSVA still remain an ongoing concern. METHODS: From January 2009 to March 2013, 22 patients with RSVA were selected for TCC. Intracardiac pressure and size of cardiac chamber were measured before and post TCC. All patients were followed up by transthoracic echocardiography at 1, 3, 6, 12 months after procedure. RESULTS: RSVA was successfully occluded in 20 patients (19 cases with Amplatzer duct occluder and one with muscular ventricular septal defect occluder). Aortic root angiography showed no shunt in 18 cases and a small residual shunt in two cases. The pressures in the right atrium, right ventricle, and pulmonary artery were significantly decreased after the procedure (P < 0.01), and the aortic pressure was elevated (P < 0.001). The internal diameters of the right atrium, left atrium, and left ventricle were also significantly declined after the procedure (P < 0.05). No complications were found after 18.5 ± 6.5 (range 3-35) months follow-up. Two patients underwent acute surgical aortic valve replacement because of procedure-related aortic valve regurgitation. CONCLUSIONS: Our results indicate that TCC is a promising alternative therapy to surgery in appropriate patients with RSVA. However, rare but severe procedure-related complications should be considered in the risk assessment.

Cholesterol efflux is LXRα isoform-dependent in human macrophages.

BACKGROUND: The nuclear receptor liver X receptor (LXR) has two isoforms: LXRα and LXRß. LXR activation promotes cholesterol efflux in macrophages, but the relative importance of each LXR isoform in mediating cholesterol efflux remains elusive. METHODS: We evaluated the ability of different doses of LXRs agonist T0901317 to affect cholesterol efflux in human macrophages and its relationship with mRNA and protein levels of several well-characterized proteins involved in cholesterol efflux, including ABCA1, ABCG1, SR-BI, LXRß and LXRα, using quantitative real-time PCR, Western blotting, and siRNA techniques. RESULTS: Here we show that LXRα rather than LXRß sustains baseline cholesterol efflux in human blood-derived macrophages. Treatment of human macrophages with a non-isoform-specific LXR agonist T0901317 substantially increased HDL- and apoA-I-mediated cholesterol efflux, which was associated with increased mRNA and protein expression levels of ABCA1, ABCG1, SR-BI, LXRα and LXRß. The siRNA- mediated silencing of LXRα, but not LXRß significantly reduced the protein levels of ABCA1,ABCG1, and SR-BI as wellas HDL- and ApoA1-mediated cholesterol in human macrophages. CONCLUSIONS: These findings imply that LXRα- rather than LXRß- specific agonists may promote reverse cholesterol transport in humans.

TNFa alter cholesterol metabolism in human macrophages via PKC-θ-dependent pathway.

BACKGROUND: Studies have shown that inflammation promoted atherosclerotic progression; however, it remains unclear whether inflammation promoted atherosclerotic progression properties by altering cholesterol metabolism in human macrophages. In the present study, we evaluated a potential mechanism of inflammation on atherogenic effects. We evaluated the ability of TNFa to affect Reverse cholesterol transport (RCT) and cholesterol uptake and its mechanism(s) of action in human macrophages. RESULTS: We initially determined the potential effects of TNFa on cholesterol efflux in the human macrophages. We also determined alterations in mRNA and protein levels of ABCA1, ABCG1, LXRa, CD-36, SR-A in human macrophages using quantitative real-time polymerase chain reaction (PCR) and Western immunoblot analyses. The cholesterol efflux rate and protein expression of ABCA1, ABCG1, LXRa, CD-36, SR-A were quantified in human macrophages under PKC-θ inhibition using PKC-θ siRNA. Our results showed that TNFa inhibited the rate of cholesterol efflux and down-regulation the expression levels of ABCA1, ABCG1 and LXRa and up-regulation the expression levels of CD-36, SR-A in human macrophages; PKC-θ inhibition by PKC-θ siRNA attenuated the effect of TNFa on ABCA1, ABCG1, LXRa, SR-A, CD-36 expression. CONCLUSIONS: Our results suggest TNFa alter cholesterol metabolism in human macrophages through the inhibition of Reverse cholesterol transport and enhancing cholesterol uptake via PKC-θ-dependent pathway, implicating a potential mechanism of inflammation on atherogenic effects.

Nifedipine enhances cholesterol efflux in RAW264.7 macrophages.

PURPOSE: Studies have shown that nifedipine protects against atherosclerotic progression, but its underlying mechanisms remain unclear. In this study, we examined if nifedipine increases macrophage cholesterol efflux, a pathway known to inhibit atherogenesis. METHODS: We evaluated the ability of different doses of nifedipine to affect cholesterol efflux in RAW264.7 macrophages and its relationship with mRNA and protein levels of several well-characterized proteins involved in cholesterol efflux, including ABCA1, ABCG1, SR-BI and LXRα, using quantitative real-time PCR, Western blotting, and siRNA techniques. RESULTS: Nifedipne at 1, 10, and 100 nmol/L increased apoA-I-mediated cholesterol efflux from 2.55 % to 5.65 %, 6.20 %, and 6.10 %, as well as HDL-mediated cholesterol efflux from 31.0 % to 42.5 %, 46.0 %, and 43.5 %, respectively, in RAW264.7 macrophages (p < 0.05), which was associated with increased mRNA expression levels of ABCA1, ABCG1, SR-BI, and LXRα (405 %, 381 %, 336 %; 890 %, 960 %, 1002 %; 285 %, 325 %, 336 %; 482 %, 445 %, 405 %, respectively, p < 0.05), and with increased protein levels of ABCA1, ABCG1, SR-BI, and LXRα (428 %, 492 %, 361 %; 288 %, 331 %, 365 %; 283 %, 320 %, 505 %; 581 %, 678 %, 608 %, respectively, p < 0.05). SiRNA-mediated silencing of LXRα revealed that LXRα was involved in these increases and the enhanced cholesterol efflux. CONCLUSION: Nifedipine may protect against atherosclerosis partly by promoting macrophage cholesterol efflux through the stimulation of LXRα-dependent expression of ABCA1, ABCG1, and SR-BI.

Exosome Derived from Coronary Serum of Patients with Myocardial Infarction Promotes Angiogenesis Through the miRNA-143/IGF-IR Pathway.

PURPOSE: Myocardial ischemia-reperfusion injury primarily causes myocardial infarction (MI), which is manifested by cell death. Angiogenesis is essential for repair and regeneration in cardiac tissue after MI. In this study, we aimed to investigate the effect of exosomes derived from the serum of MI patients in angiogenesis and its related mechanism. PATIENTS AND METHODS: Exosomes, isolated from serum, were collected from MI (MI-exosome) and control (Con-exosome) patients. After coculturing with human umbilical vein endothelial cells, MI-exosome promoted cell proliferation, migration, and tube formation. RESULTS: The results revealed that the production and release of MI-exosome were associated with cardiomyocytes. Moreover, microarray assays demonstrated that miRNA-143 was significantly decreased in MI-exosome. Meanwhile, the overexpression and knockdown of miRNA-143 could inhibit and enhance angiogenesis, respectively. Furthermore, the effect of exosomal miRNA-143 on angiogenesis was mediated by its targeting gene, insulin-like growth factor 1 receptor (IGF-IR), and was associated with the production of nitric oxide (NO). CONCLUSION: Taken together, exosomes derived from the serum of patients with MI promoted angiogenesis through the IGF-IR/NO signaling pathway. The results provide novel understanding of the function of exosomes in MI.

Clinical efficiency and safety analysis of transcatheter closure of multiple atrial septal defects in adults.

BACKGROUND: Transcatheter closure of atrial septal defects (ASDs) is currently a reliable alternative to surgery, even though challenging in patients with multiple ASDs. HYPOTHESIS: The aim of this study was to evaluate the clinical efficiency and safety of transcatheter closure in multiple ASDs. METHODS: Multiple ASDs were diagnosed by transthoracic echocardiography (TTE) or transesophageal echocardiography (TEE). The occlusive condition and distance between 2 adjacent ASDs were measured by TTE examination. Then, the number and size of the occluder(s) was determined. TTE examinations were performed after transcatheter closure as follow-up. RESULTS: The transcatheter procedure was successful in 15 patients with multiple ASDs, using a single occluder in 9 patients and 2 occluders in the remaining 6 patients. Overall, 21 ASD occluders were implanted. During a follow-up period of 6 mo to 5 y, a slight residual shunt was found in 1 patient without any symptoms; a moderate residual shunt was identified at the inferior vena cava and the occluder was removed by surgery 1 mo after procedure. Other complications, including endocarditis, arrhythmia, thromboembolism, and atrioventricular valve damage were not recorded in any of the 15 patients during the follow-up period. CONCLUSION: Transcatheter closure of multiple ASDs is safe and efficient. Two occluders are necessary for the distance of 2 ASDs more than 7 mm, and a single occluder is sufficient for those 7 mm or less.

[Prognostic impact of heart block during transcatheter closure of ventricular septal defect].

OBJECTIVE: To investigate the prognostic impact of heart block during the transcatheter closure of ventricular septal defect (VSD). METHODS: Forty three patients developed complete left or right bundle branch block (CLBBB, CRBBB), incomplete left or right bundle branch block (ILBBB, IRBBB), and atrioventricular block (AVB) during and within 1 week post procedure were followuped at 1, 6, 12, 24, 36, 48 and 60 months post procedure. Electrocardiogram, dynamic electrocardiogram and transthoracic echocardiography were made. RESULTS: Bundle branch block and atrioventricular block were detected in 26 patients (CLBBB n = 4, CRBBB n = 5, ILBBB n = 2, IRBBB n = 10 and third-degree AVB n = 5) during the transcatheter closure of VSD, and in 17 patients (CLBBB n = 5, CRBBB n = 2, first-degree AVB n = 3, second-degree I-type AVB n = 1 and third-degree AVB n = 6) within 1 week post procedure. Heart block disappeared in 33 patients (76.7%) before discharge, in 37 patients (86.1%) at 1 month and in 41 patients (95.4%) at 6 months post procedure. CLBBB or CRBBB was seen in two cases at 24 months after closure. There was no heart failure and serious cardiac dilatation during follow up. CONCLUSION: The heart block occurred during the periprocedure period of transcatheter closure of VSD was a benign phenomenon without prognostic importance.

Collagen biomaterial for the treatment of myocardial infarction: an update on cardiac tissue engineering and myocardial regeneration.

Myocardial infarction (MI) remains one of the leading cause of mortality over the world. However, current treatments are more palliative than curative, which only stall the progression of the disease, but not reverse the disease. While stem cells or bioactive molecules therapy is promising, the limited survival and engraftment of bioactive agent due to a hostile environment is a bottleneck for MI treatment. In order to maximize the utility of stem cells and bioactive molecules for myocardial repair and regeneration, various types of biomaterials have been developed. Among them, collagen-based biomaterial is widely utilized for cardiac tissue engineering and regeneration due to its optimal physical and chemical properties. In this review, we summarize the properties of collagen-based biomaterial. Then, we discuss collagen-based biomaterial currently being applied to treat MI alone, or together with stem cells and/or bioactive molecules. Finally, the delivery system of collagen-based biomaterial will also be discussed.

Physical exercise inhibits atherosclerosis development by regulating the expression of neuropeptide Y in apolipoprotein E-deficient mice.

AIMS: Population-based studies have shown that exercise has anti-atherosclerotic effects, but the mechanisms underlying this cardiac protection are poorly understood. The aim of this study was to investigate if the anti-atherosclerotic effects of exercise are associated with changes in neuropeptide Y (NPY) expression in apolipoprotein E-deficient (ApoE-/-) mice. MAIN METHODS: Thirty-one male ApoE-/- mice were randomly divided into regular exercise (5 days/week), occasional exercise (1-2 days/week), and sedentary groups. After 8 weeks, atherosclerotic burden and plaque stability were measured by histological and morphological analysis. Quantitative real-time PCR and immunohistochemistry were used to measure the expression of NPY and its receptors in the aorta. KEY FINDINGS: Eight weeks of occasional exercise was equally effective as regular exercise at preventing atherosclerotic plaque formation and enhancing atherosclerotic plaque stability. This was shown by increased plaque collagen and smooth muscle cell content and decreased plaque lipid and macrophage content. The expression of NPY and its receptors in the vasculature was decreased in the regular exercise and occasional exercise groups, and this expression was significantly correlated with the progress of atherosclerosis. Moreover, exercise may reduce the activity of macrophages by down-regulating the expression of NPY Y1 receptors, thereby reducing the release of inflammatory cytokines. SIGNIFICANCE: These results suggest that exercise training can attenuate plaque burden and enhance atherosclerotic plaque stability. The anti-atherosclerotic effect of exercise appears to be, at least in part, dependent on down-regulation of the expression of NPY and its receptors (especially Y1 receptors) in the aorta.

Relationship among soluble CD105, hypersensitive C-reactive protein and coronary plaque morphology: an intravascular ultrasound study.

BACKGROUND: Rupture of unstable plaque with subsequent thrombus formation is the common pathophysiological substrate of acute coronary syndrome (ACS). It is of potential significance to explore the blood indexes predicting plaque characteristics. We investigated the relationship among soluble CD105, hypersensitive C-reactive protein (hs-CRP), and coronary plaque morphology. METHODS: A clinical study from April 2004 to December 2006 was conducted in 130 patients who were divided into 3 groups: 56 patients (43.1%) in stable angina (SA) group, 52 patients (40.0%) in unstable angina (UA) group and 22 patients (16.9%) in acute myocardial infarction group. The concentrations of soluble CD105 and hs-CRP were measured in all of the patients by cardioangiography (CAG). Plasma samples of arterial blood were collected prior to the procedure. The levels of soluble CD105 and hs-CRP were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Unstable and ruptured plaque was found more frequently in patients with acute myocardial infarction and UA. External elastic membrane cross-sectional area (EEM CSA), plaque area, lipid pool area and plaque burden were significantly larger in the ruptured and unstable plaque group. Positive remodeling, thinner fabric-cap, smaller minimal lumen cross-sectional area (MLA), dissection and thrombus were significantly more frequent in the ruptured and unstable plaque group. Remodeling index (RI) was positively correlated with the levels of soluble CD105 in the UA group (r = 0.628, P < 0.01) and the acute myocardial infarction group (r = 0.639, P < 0.01). The levels of soluble CD105 and hs-CRP were higher in the ruptured plaque group. Soluble CD105 > 4.3 ng/ml was used to predict ruptured plaque with a receiver operating characteristic (ROC) curve area of 0.77 (95% confidence interval (CI), 66.8% - 87.2%), a sensitivity of 72.8%, a specificity of 78.0% and an accuracy of 70.2% (P < 0.01), similarly for hs-CRP > 5.0 mg/ml with a ROC curve area of 0.70 (95% CI, 59.2% - 80.2%), a sensitivity of 70.2%, a specificity of 76.2% and an accuracy of 67.2% (P < 0.01). CONCLUSIONS: The plaque characteristics correlate with the clinical presentation. The elevation of soluble CD105 and hs-CRP is related to the plaque instability and rupture.

Transcription factor Tbx18 induces the differentiation of c-kit+ canine mesenchymal stem cells (cMSCs) into SAN-like pacemaker cells in a co-culture model in vitro.

Bone mesenchymal stem cells (MSCs), as well as cardiomyocytes, are derived from early mesoderm, becoming committed to their fate under the influence of different differentiation factors. We examined whether the overexpression of Tbx18 can induce the differentiation of c-kit+ cMSCs into a phenotype similar to that of native pacemaker cells and whether these transfected cells can couple to adjacent atrial cells with functional consequences. The c-kit+ cMSCs were first sorted, then transfected with different lentiviral vectors. Tbx18-c-kit+ cMSCs represented the experimental group, while EYFP-c-kit+ cMSCs and canine sinoatrial node (SAN) cells were used as controls. Within days of transfection, the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel HCN4 protein and gap junction protein Connexin 45 (Cx45) expression in Tbx18-c-kit+ cMSCs were 12-fold and 5.6-fold higher, respectively, than that in EYFP-c-kit+ cMSCs. After co-culture with canine atrial cells in vitro for three days, the funny currents (If) were recorded in the Tbx18-c-kit+ cMSCs, but not in EYFP-c-kit+ cMSCs. The trend of these If currents was highly similar to that of SAN cells, although the current density was smaller. The Tbx18-EYFP-c-kit+ cMSCs showed responsiveness to ß-adrenergic stimulation, and the intracellular cyclic adenosine monophosphate (cAMP) level was higher than that in EYFP-c-kit+ cMSCs. The Tbx18-EYFP-c-kit+ cMSCs delivered fluorescent dye to neighboring atrial cells via gap junctions, thus these cell pairs could communicate as a pacemaker unit. We propose that the overexpression of Tbx18 in c-kit+ cMSCs induces their differentiation to SAN-like pacemaker cells.

Update on glycerol-3-phosphate acyltransferases: the roles in the development of insulin resistance.

Glycerol-3-phosphate acyltransferase (GPAT) is the rate-limiting enzyme in the de novo pathway of glycerolipid synthesis. It catalyzes the conversion of glycerol-3-phosphate and long-chain acyl-CoA to lysophosphatidic acid. In mammals, four isoforms of GPATs have been identified based on subcellular localization, substrate preferences, and NEM sensitivity, and they have been classified into two groups, one including GPAT1 and GPAT2, which are localized in the mitochondrial outer membrane, and the other including GPAT3 and GPAT4, which are localized in the endoplasmic reticulum membrane. GPATs play a pivotal role in the regulation of triglyceride and phospholipid synthesis. Through gain-of-function and loss-of-function experiments, it has been confirmed that GPATs play a critical role in the development of obesity, hepatic steatosis, and insulin resistance. In line with this, the role of GPATs in metabolism was supported by studies using a GPAT inhibitor, FSG67. Additionally, the functional characteristics of GPATs and the relation between three isoforms (GPAT1, 3, and 4) and insulin resistance has been described in this review.

Cold exposure promotes obesity and impairs glucose homeostasis in mice subjected to a high­fat diet.

Cold exposure is considered to be a form of stress and has various adverse effects on the body. The present study aimed to investigate the effects of chronic daily cold exposure on food intake, body weight, serum glucose levels and the central energy balance regulatory pathway in mice fed with a high­fat diet (HFD). C57BL/6 mice were divided into two groups, which were fed with a standard chow or with a HFD. Half of the mice in each group were exposed to ice­cold water for 1 h/day for 7 weeks, while the controls were exposed to room temperature. Chronic daily cold exposure significantly increased energy intake, body weight and serum glucose levels in HFD­fed mice compared with the control group. In addition, 1 h after the final cold exposure, c­fos immunoreactivity was significantly increased in the central amygdala of HFD­fed mice compared with HFD­fed mice without cold exposure, indicating neuronal activation in this brain region. Notably, 61% of these c­fos neurons co­expressed the neuropeptide Y (NPY), and the orexigenic peptide levels were significantly increased in the central amygdala of cold­exposed mice compared with control mice. Notably, cold exposure significantly decreased the anorexigenic brain­derived neurotropic factor (BDNF) messenger RNA (mRNA) levels in the ventromedial hypothalamic nucleus and increased growth hormone releasing hormone (GHRH) mRNA in the paraventricular nucleus. NPY­ergic neurons in the central amygdala were activated by chronic cold exposure in mice on HFD via neuronal pathways to decrease BDNF and increase GHRH mRNA expression, possibly contributing to the development of obesity and impairment of glucose homeostasis.

Clinical efficiency and safety analysis of transcatheter interventional therapy for compound congenital cardiovascular abnormalities.

OBJECTIVE: To investigate the efficiency and safety of transcatheter interventional therapy for compound congenital cardiovascular abnormalities. METHODS: From Nov 2001 to Jun 2006, a total of 36 patients (17 male, 19 female), aged 17.20 +/- 10.52, with compound congenital cardiovascular abnormalities underwent transcatheter interventional procedure. These patients included 11 with perimembranous ventricular septal defect (PVSD) and patent ductus arteriosus (PDA), 8 patients with PVSD and atrial septal defect (ASD), 8 patients with ASD and PDA, 7 patients with ASD and pulmonary stenosis (PS), 1 patient with ASD and mitral stenosis(MS), 1 patient with coarctation of aorta (COA) and PDA. According to the principle of "easy first, hard second," balloon valvuloplasties of PS or MS were performed before the closure of PVSD, and of PDA and ASD. Electrocardiogram and transthoracic echocardiogram were examined at 4 days, 1, 2, 6 and 12 months, respectively, after each procedure. RESULTS: Transcatheter interventional therapy for compound congenital cardiovascular abnormalities was successful in all patients. Among these, 2 occluders were planted in each of 27 patients, 7 patients with ASD combined with PS and 1 patient with ASD combined with MS underwent successfully performed balloon valvuloplasty and ASD closure, 1 patient with COA combined with PDA underwent successfully performed balloon valvuloplasty and subsequent covered stent implantation. No patient encountered serious adverse events during the (30.5 +/- 14.6) months of follow-up. CONCLUSIONS: Transcatheter interventional therapy for compound congenital cardiovascular abnormalities could obtain satisfactory results with technical feasibility.

Effects of Neuropeptide Y on Stem Cells and Their Potential Applications in Disease Therapy.

Neuropeptide Y (NPY), a 36-amino acid peptide, is widely distributed in the central and peripheral nervous systems and other peripheral tissues. It takes part in regulating various biological processes including food intake, circadian rhythm, energy metabolism, and neuroendocrine secretion. Increasing evidence indicates that NPY exerts multiple regulatory effects on stem cells. As a kind of primitive and undifferentiated cells, stem cells have the therapeutic potential to replace damaged cells, secret paracrine molecules, promote angiogenesis, and modulate immunity. Stem cell-based therapy has been demonstrated effective and considered as one of the most promising treatments for specific diseases. However, several limitations still hamper its application, such as poor survival and low differentiation and integration rates of transplanted stem cells. The regulatory effects of NPY on stem cell survival, proliferation, and differentiation may be helpful to overcome these limitations and facilitate the application of stem cell-based therapy. In this review, we summarized the regulatory effects of NPY on stem cells and discussed their potential applications in disease therapy.