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Leptin signaling and leptin resistance

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《医学前沿（英文）》 2013年第7卷第2期页码 207-222 doi: 10.1007/s11684-013-0263-5

摘要：

Leptin is secreted into the bloodstream by adipocytes and is required for the maintenance of energy homeostasis and body weight. Leptin deficiency or genetic defects in the components of the leptin signaling pathways cause obesity. Leptin controls energy balance and body weight mainly through leptin receptor b (LEPRb)-expressing neurons in the brain, particularly in the hypothalamus. These LEPRb-expressing neurons function as the first-order neurons that project to the second-order neurons located within and outside the hypothalamus, forming a neural network that controls the energy homeostasis and body weight. Multiple factors, including inflammation and endoplasmic reticulum (ER) stress, contribute to leptin resistance. Leptin resistance is the key risk factor for obesity. This review is focused on recent advance about leptin action, leptin signaling, and leptin resistance.

关键词： leptin signaling leptin receptor energy balance leptin resistance obesity

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Construction and identification of lentiviral RNA interference vector of rat leptin receptor gene

Zhengjuan LIU, Jie BIAN, Yuchuan WANG, Yongli ZHAO, Dong YAN, Xiaoxia WANG

《医学前沿（英文）》 2009年第3卷第1期页码 57-60 doi: 10.1007/s11684-009-0003-z

摘要： Leptin resistance is a main mechanism of acquired childhood obesity, and the suppression of long form of leptin receptor (OBRb) gene expression in diet-induced obese rats indicates that the down-regulation of OBRb gene expression plays a pivotal role in the mechanism of leptin resistance. The aim of the present study was to construct the lentiviral RNA interference (RNAi) vector of rat OBRb gene and evaluate the effects of siRNA on silencing OBRb gene expression. The target sequence of siRNA-OBRb was designed, and the complementary DNA containing both sense and antisense oligonucleotides was synthesized. After phosphorylation and annealing, these double-stranded DNA was cloned to pRNA-lentivector-VGFP to construct pRNA-Lenti-OBRb-VGFP recombinants with U6-containing promoter, target sequence and Poly III terminator. Then, the products were confirmed by electrophoresis and sequencing analysis, and the effects of RNAi on reducing gene expression were further confirmed by real-time polymerase chain reaction in transfected rat glioma cells expressing OBRb. The target sequence of siRNA-OBRb was successfully cloned to pRNA-lentivector-VGFP, and the RNAi protocol specifically reduced the expression of OBRb mRNA by approximately 80% compared with controls in transfected rat glioma cells. The successful construction of rat lentivirus vectors expressing OBRb-specific shRNA may be useful for further investigation .

关键词： receptors leptin RNA interference lentivirus vector

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The change of serum leptin and its relationship with platelet membrane glycoprotein Ib in patients with

XIA Dasheng, SONG Yanqiu, LI Chao, ZHANG Feng, WEI Minxin

《医学前沿（英文）》 2007年第1卷第4期页码 352-355 doi: 10.1007/s11684-007-0067-6

摘要： The aim of this paper was to investigate the change of serum leptin and its relationship with platelet membrane glycoprotein Ib (GP Ib) in patients with coronary heart disease (CHD). The enrolled included 50 patients with CHD (CHD group) and 30 patients without CHD (control group) who were diagnosed by coronary angiography. The positive percentage and the average fluorescence intensity of platelet membrane GP Ib were detected by full-blood flow cytometry. Serum leptin was detected by enzyme linked immunosorbent assay. The positive percentage and the average fluorescence intensity of platelet membrane GP Ib in the CHD group were significantly lower than those in the control group (<0.05). After correcting the differences of systolic blood pressure, body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), fasting glucose, PPBS, fasting insulin and quantitative insulin sensitive index, serum leptin level in the CHD group was significantly higher than that in the control group (<0.05). Single factor correlative analysis revealed that serum leptin in CHD patients was negatively correlated with the average fluorescence intensity of platelet membrane GP Ib (<0.05). Multifactorial stepwise regression analysis showed that serum leptin in CHD patients was independently negatively correlated with the average fluorescence intensity of platelet membrane GP Ib (<0.05). Logistic analysis demonstrated that serum leptin was independently correlated with the risk of CHD (<0.05). Hyperleptinemia was verified in CHD patients. The increase of serum leptin could affect blood platelet activation. Hyperleptinemia may play an important role in the pathogenesis of CHD.

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Effect of intestinal ischemia/reperfusion injury on leptin and orexin-A levels

LIN Ji, YAN Guangtao, HAO Xiuhua, ZHANG Kai, GAO Xiaoning, LIAO Jie

《医学前沿（英文）》 2007年第1卷第1期页码 87-92 doi: 10.1007/s11684-007-0017-3

摘要： The aim of this paper is to explore the effect of intestinal ischemia/reperfusion (I/R) injury on leptin and orexin-A levels in peripheral blood and central secretory tissues, and to examine the roles of leptin and orexin-A in acute inflammatory responses. An intestinal I/R injury model of rats was made; the rats were grouped according to the time of after 60 min ischemia. Radioimmunoassay was employed to detect the levels of leptin in serum and adipose tissue and orexin-A levels in plasma and hypothalamus. Reverse transcriptase-polymerase chain reaction was used to detect mRNA expressions of adipose leptin and hypothalamus orexin-A. Compared with the levels before the injury, serum leptin in 60 min ischemia/30 min reperfusion (I60´R30´) group decreased and that of I60´R360´ group increased. Compared with sham-operation group (sham group) after injury, serum leptin level of I60´R360´ group increased, adipose leptin levels of I60´R30´ and I60´R90´ decreased, and adipose leptin in I60´R360´ group increased. After the injury, adipose leptin mRNA expressions of I60´R30´, I60´R240´ and I60´R360´ increased, whereas that of I60´R150´ group decreased as compared with the sham group. There was no significant difference in the protein levels of orexin-A, either between plasma and hypothalamus or between pre- and post-I/R injury. Compared with sham group, hypothalamus orexin-A mRNA expressions of I60´R30´ and I60´R90´ decreased gradually after the injury, with that of I60´R150´ group reaching the lowest, and those of I60´R240´ and I60´R360´ recovering gradually, although they were still significantly lower than that of sham group. Leptin and orexin-A respond to intestinal I/R injury in a time-dependent manner, with leptin responding more quickly than orexin-A does, and both of them may contribute to the metabolic disorders in acute inflammation.

关键词： significant difference intestinal I/R transcriptase-polymerase metabolic central secretory

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Glyco-functionalised quantum dots and their progress in cancer diagnosis and treatment

Jayshree Ashree, Qi Wang, Yimin Chao

《化学科学与工程前沿（英文）》 2020年第14卷第3期页码 365-377 doi: 10.1007/s11705-019-1863-7

摘要： Despite all major breakthroughs in recent years of research, we are still unsuccessful to effectively diagnose and treat cancer that has express and metastasizes. Thus, the development of a novel approach for cancer detection and treatment is crucial. Recent progress in Glyconanotechnology has allowed the use of glycans and lectins as bio-functional molecules for many biological and biomedical applications. With the known advantages of quantum dots (QDs) and versatility of carbohydrates and lectins, Glyco-functionalised QD is a new prospect in constructing biomedical imaging platform for cancer behaviour study as well as treatment. In this review, we aim to describe the current utilisation of Glyco-functionalised QDs as well as their future prospective to interpret and confront cancer.

关键词： carbohydrate leptin glyco-functionalised QD bioimaging cancer diagnosis and treatment