Serum leptin and soluble leptin receptor in non-alcoholic fatty liver disease

AIM: To determine the role of leptin system in non-al- coholic fatty liver disease (NAFLD) development by deli- neating the changes in serum levels of leptin and soluble leptin receptor (sOB-R). METHODS: Blood samples were collected from 30 consecutive patients with liver-biopsy-proven NAFLD and 30 patients with cholecystolithiasis (stationary phase) as controls. Serum leptin levels were determined by radio- immunoassay and concentration of sOB-R was measured by ELISA. Body mass index (BMI) was calculated for all subjects, and serum insulin, C-peptide, and lipoprotein levels were also detected. RESULTS: Mean serum leptin level and BMI in the NAFLD group were significantly higher than in the con- trols (both P < 0.001), but mean sOB-R level was lower in the NAFLD group when compared to the controls. Both men and women in the NAFLD group had higher mean serum leptin levels and lower sOB-R levels than did the men and women in the control group (all P < 0.001). The- re was a significant negative correlation between serum leptin and sOB-R levels (r = -0.725, P < 0.001). Multiva- riate analysis showed that the percentage of hepatocyte steatosis, sex, BMI, and homeostasis model assessment of insulin resistance (HOMA IR) were independently rela- ted to serum leptin levels. CONCLUSION: Elevated serum leptin seems to be afeature of steatosis, and serum leptin seems to increase as hepatocyte steatosis develops. An enhanced release of leptin is accompanied by an decrease in sOB-R con- centration, which suggests higher resistance of periphe- ral tissues towards the action of leptin.

Neuropeptide Y and leptin receptor expression in the hypothalamus of rats with chronic immobilization stress

In this study, Sprague-Dawley rats were immobilized to a frame for 3 hours a day for 21 days to establish a model of chronic immobilization stress. The body weight and food intake of rats subjected to chronic immobilization stress were significantly decreased compared with the control group. Dual-labeling immunofluorescence revealed that the expression of leptin receptor and the co-localization coeffient in these leptic receptor neurons in the arcuate nucleus of the hypothalamus were both upregulated, while the number of neuropeptide Y neurons was decreased. Chronic immobilization stress induced high expression of leptin receptor in the arcuate nucleus and suppressed the synthesis and secretion of neuropeptide Y, thereby disrupting the pathways in the arcuate nucleus that regulate feeding behavior, resulting in diminished food intake and reduced body weight.

Possible involvement of leptin and leptin receptor in developing gastric adenocarcinoma

AIM： To investigate the expression of leptin and leptin receptor （ob-R） in intestinal-type gastric cancer and precancerous lesions, and to explore the possible mechanism and role of the leptin system in developing intestinal-type gastric adenocarcinoma.METHODS： Immunohistochemistry was performed to examine the expression of leptin and leptin receptor in archival samples of gastric adenocarcinoma and preneoplastic lesions, including intestinal metaplasia and mild to severe gastric epithelial dysplasia. Positive staining was identified and percentage of positive staining was graded.RESULTS： Dual expression of leptin and leptin receptor were detected in 80% （16/20） intestinal metaplasia, 86.3% （25/30） mild gastric epithelial dysplasia, 86.7% （26/30） moderate gastric epithelial dysplasia, 93.3% （28/30） severe gastric epithelial dysplasia, 91.3% （55/60） intestinal-type gastric adenocarcinoma and 30.0% （9/30） diffuse-type gastric carcinoma. The percentage of dual expression of leptin and leptin receptor in intestinal-type gastric adenocarcinoma was significantly higher than that in diffuse-type gastric adenocarcinoma （χ^2 = 37.022, P〈0.01）.CONCLUSION： Our results indicate the presence of an autocrine loop of leptin system in the development of intestinal-type gastric adenocarcinoma.

Clinical significance of the leptin and leptin receptor expressions in prostate tissues

Aim： To evaluate the expression of leptin and leptin receptor in benign prostatic hyperplasia （BPH） and prostate cancer （PCa）, and to investigate whether they are associated with the development and progression of PCa. Methods： hnmunohistochemical staining was performed to examine the expression of leptin and leptin receptor in BPH and PCa. PCa was divided into three groups： localized PCa, locally advanced PCa and metastatic PCa. The positive staining was identified and the percentage of the positive staining was graded. We also assessed the relationship between both the Gleason score and body mass index （BMI） and PCa. Results： The percentage of the leptin expression in PCa was significantly higher than that in BPH （P 〈 0.01）. For the PCa group, the expressed levels of leptin showed a considerable correlation with localized PCa and metastatic PCa （P 〈 0.05）. Leptin receptor, however, did not reveal a definite difference between BPH and PCa. The expression of leptin indicated a significant difference between well-differentiated PCa （Gleason score ≤6） and poorly differentiated PCa （Gleason score 8-10） （P 〈 0.05）. The relation between the leptin expression level in PCa and the BMI was not remarkable （P = 0.447）. Conclusion： Our results suggest that leptin might have a promoting effect on the carcinogenesis and progression of PCa.

Expression of Long Form Leptin Receptor mRNA in Pituitary of Pigs around Puberty

[ Objective] To study the expression of long form leptin receptor （Ob.Rb） mRNA in pituitary of pigs around puberty and explore the rela- tionship between Ob-Rb mRNA and porcine development around pituitary. [Method] Three Sujiang pigs were randomly selected at the age of 120 d, puberty and 180 d, respectively. A pair of primers was designed according to the Ob-Rb sequence published in the GenBank. Total RNAs were extracted from pituitary. The expression of Ob-Rb mRNA was detected by the real-time quantitative RT-PCR. [ Result] The Ob-Rb mRNA was de- tected in pituitaries of pigs at the age of 120 d, puberty and 180 d, respectively. The expression level of Ob-Rb mRNA was lowest at puberty. It was significantly different from that in the 120-day-old pigs and not significantly different from that in the 180-day-old pigs. [ Conclusion] The low expres- sion level of Ob-Rb mRNA is conductive to the arrival of puberty.

Association analyses of single nucleotide polymorphisms in the <i>leptin</i>and <i>leptin receptor</i>genes on milk and morphological traits in Holstein cows

To date, only a few SNP in the leptin receptor gene have been detected and analyzed while the leptin gene has been extensively characterized and several polymorphisms were detected and associated to functional and productive traits in cattle. In this work, for the first time, the bovine leptin receptor gene was fully characterized by sequencing the whole coding region and part of the 5’ flanking region. A group of 95 Holstein cows was genotyped in order to search for SNP at both the LEPR and LEP genes, and to associate them with milk and morphological traits. Nine novel SNP in the leptin receptor gene and one novel SNP in the leptin gene were detected. Four SNP of the leptin receptor gene and one SNP of leptin gene showed a significant effect on one or more analyzed traits, and, in all cases, the greatest effect was observed on fat content. This study provided knowledge of the existence of further polymorphisms in the leptin receptor and leptin genes that have an influence on some important economic traits.

Differential Expression of Leptin and Leptin Receptor mRNA in Obese and Non-Obese Women across the Menstrual Cycle Title

OBJECTIVE: The aim of this study was to investigate the messenger ribonucleic acid expression of leptin (L-mRNA) and the leptin receptor (OB-RmRNA) in subcutaneous fat tissue and to determine their relationship with leptin and testosterone and steroid serum levels over the course of the menstrual cycle (MC), in obese (OBW) and non-obese women (NOW). DESIGN: Observational study investigating mRNA transcript expression of leptin and the leptin receptor from human subcutaneous fat specimens, as well as leptin serum levels, both in relation to the testosterone and sex hormones during the MC in obese and non-obese women. METHODS: Nineteen women, thirteen with a body mass index (BMI) > 25 Kg/m2 and 6 with BMI 2 were included. RT-PCR was used to detect L-mRNA transcripts of leptin and its receptor in samples from 28 fat biopsies taken from seven volunteers (20 from OW and 8 from NOW). The serum concentrations of leptin and steroid hormones were measured throughout the MC using radioinmuno analysis. RESULTS: The percentages of women expressing leptin L-mRNA during the phases of the MC were: early follicular (EF), 14.3%;late follicular (LF), 28.6%;early luteal (EL), 14.3%;and late luteal (LL), 42.9%. The percentages of OB-RmRNA were: EF, 71.4%;LF, 14.3%;EL, 28.6%;and LL, 71.4%. Leptin serum levels were directly related to BMI (p < 0.001), and testosterone (p < 0.001) and indirectly to SHBG (p < 0.001). CONCLUSION: The L-mRNA expression and its receptor in subcutaneous human tissue are regulated throughout the MC in a periodic manner. The physiological role of testosterone in regulation of expression L-mRNA and OB-RmRNA during the secretory phase of the MC in obese women requires further investigation.

Breeding of Leptin Receptor Gene Knockout Mice and Genotype Identification of the Offspring

The leptin（ LP） receptor gene heterozygous mice were mated in four ways. Genomic DNA was extracted from offspring tails and analyzed by PCR. The result showed that the ratios of the offspring genotypes fit the Mendel＇s laws. The male and female LP^（-/-）mice（ DB / DB mice） were infertile. LP^（-/-）mice could be effectively bred by mating of male and female LP^（＋/-）mice. PCR methods could identify LP^（-/-）mice precisely.

血清FGFR2、Leptin对特发性矮小症患儿的诊断价值及其水平与骨代谢指标的相关性

目的探讨血清成纤维生长因子受体2(FGFR2)、瘦素(Leptin)水平与特发性矮小症患儿骨代谢指标的相关性及其对疾病的诊断价值。方法选取2021年9月至2023年9月于该院就诊的138例特发性矮小症患儿为观察组,另选取同期于该院进行健康体检的141例健康儿童为对照组。采用酶联免疫吸附试验检测血清FGFR2、Leptin水平;采用全自动生化分析仪检测25-羟基维生素D[25-(OH)D]、Ⅰ型前胶原氨基酸前肽(PⅠNP)、骨钙素(OC)、骨特异性碱性磷酸酶(BAP)等骨代谢指标水平;采用Pearson相关分析特发性矮小症患儿血清FGFR2、Leptin水平与骨代谢指标水平的相关性;采用多因素Logistic回归分析影响特发性矮小症发病的因素;绘制受试者工作特征(ROC)曲线分析血清FGFR2、Leptin单独及联合检测对特发性矮小症的诊断价值。结果观察组体质量、身高及25-(OH)D、PⅠNP、OC、BAP、FGFR2、Leptin水平显著低于对照组,性发育状态Ⅱ~Ⅴ期患儿比例显著高于对照组,差异均有统计学意义(P<0.05)。Pearson相关性分析结果显示,特发性矮小症患儿血清FGFR2、Leptin水平与25-(OH)D、PⅠNP、OC、BAP水平均呈正相关(P<0.05)。多因素Logistic回归分析结果显示,FGFR2、Leptin水平升高是特发性矮小症发病的保护因素(P<0.05)。ROC曲线结果显示,血清FGFR2、Leptin单独及联合诊断特发性矮小症的曲线下面积分别为0.834、0.851、0.914。结论特发性矮小症患儿血清FGFR2、Leptin水平均较低,且二者均与骨代谢指标显著相关,推测其在诊断特发性矮小症中具有一定价值。

Expression of Leptin Long-form Receptor mRNA in Luteinized Granulosa Cells of Obese Women with Polycystic Ovary Syndrome

To investigate the expression of mRNA of leptin long-form receptor （OB-Rb） in luteinized granulosa ceils of obese women with polycystic ovary syndrome （PCOS）, and to determine the role of leptin in the physiopathology of PCOS, luteinized granulosa cells were collected from the follicle fluid of 10 obese women who met the diagnostic criteria for PCOS and their BMI was equal to or greater than 25 kg/m^2, and at the same time, granulosa cells were collected from 10 normal women undergoing IVF-ET who served as the control group. Some luteinized granulosa cells were taken from normal women for in-vitro culture, into which human leptin of different concentrations was added （0, 10, 100 and 1000 ng/mL）. After stimulation with leptin for 48 h, RT-PCR was employed for the detection of the expression of OB-RLInRNA in the luteinized granulosa cells. Our results showed that the level of OB-RLmRNA in luteinized granulosa cells of obese PCOS women was higher than those in the control （P〈0.05）. In luteinized granulosa cells cultured in vitro and stimulated by human leptin for 48 h, the level of OB-RLmRNA was higher than those without leptin stimulation （P〈0.01）, and when leptin concentration was at 100 ng/mL, and the level of OB-RLmRNA reached a peak, It is concluded that in obese PCOS women, the level of serum leptin is increased, which promotes the expression of OB-RL in luteinized granulosa cells and increases the sensitivity of the granulosa cells to leptin. Leptin may contribute to anovulation in obese women with PCOS.

Overexpression of leptin and leptin receptors in breast cancer positively correlates with clinicopathological features

Obesity has been reported to increase postmenopausal breast cancer risk by 30% to 50%, and obese breast cancer patients have been shown to present more aggressive breast cancer pathological features As most breast cancers are sex hormone-dependent, adipocytokines derived from adipose tissue, such as leptin, may account for the positive association between obesity and breast cancer. Leptin, a 16-kDa protein product of the obese gene, was initially regarded as a neuroendocrine factor in the hypothalamus to maintain homeostasis of body weight by regulating food intake and energy expenditure.

Assessment of ghrelin and leptin receptor levels in postmenopausal women who received oral or transdermal menopausal hormonal therapy

Objective： In postmenopausal women, an increased leptin concentration and reduced levels of ghrelin and adiponectin were observed. The aim of this study was to evaluate the concentrations of the active form of ghrelin, total ghrelin, leptin receptor, lipoprotein（a） （Lp（a））, and plasminogen activator inhibitor type 1 （PAl-l） in postmenopausal women who received oral or transdermal menopausal hormonal therapy （MHT）. Methods： The study involved 76 healthy women： 46 women aged from 44 to 58 years who received oral （26） or transdermal （20） MHT; the control group consisted of 30 women aged from 44 to 54 years who did not receive MHT. The plasma concentrations of total ghrelin, the active form of ghrelin, Lp（a）, and PAI-I：Ag were measured by enzyme-linked immunosorbent assay （ELISA）. The concentration of the leptin receptor was measured by enzyme immunometric assay （EIA）. Results： We observed a significantly higher concentration o~ total ghrelin and the active form of ghrelin in women who received transdermal MHT in comparison with those who took oral MHT. We also found a significantly lower concentration of total ghrelin in women who received oral MHT compared with the control group. A higher concentration of PAl-1 ：Ag was found in the group of women who took transdermal MHT in comparison with those who took oral MHT and with the control group. The differences were statistically significant. Additionally, we found a significant negative correlation between the concentrations of total ghrelin and PAl-1 ：Ag and a positive correlation between the concentrations of total ghrelin and leptin receptor in women who received transdermal MHT. Conclusions： The study showed that women who used transdermal MHT had higher levels of total ghrelin than women who took oral MHT. This indicates a beneficial effect of the transdermal route of MHT. However, transdermal therapy was associated with adverse effects with regard to the observed higher levels of PAl-1 ：Ag, which in turn, can lead to a reduction in fibrinolytic activity.

Expression detection and partial cloning of porcine leptin receptor (OBR) gene

The product of the obesity gene, called leptin, is an important regulator of adiposity, which mainly functions via its regulation of feed intake and energy metabolism. Both obesity gene (ob gene) and leptin receptor gene (OBR gene) are thought to play a major role in controlling of body fat mass as well as body weight. The result of RT-PCR shows that levels of pig OBR mRNA are higher in hypothalamus, lung and liver, and lower expression can be detected in other tissues. Total RNA purified from 11 different organs and tissues have been hybridized with pig OBR cDNA probes. The hybridization signals are shown in 7 organs and tissues. 4.1 and 3.8 kb bands were observed from hypothalamus, whereas 3.8 and 3.5 kb bands were observed in other tissues instead. The nearly complete sequence of the extracellular domain of pig OBR gene was obtained. The homology of sequence is 89.2% between pig and human, 80.3% between pig and mouse. Alignment of the predicted ammo acid sequence of OBR in pig, human and mouse shows

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

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 com-plementary 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 analy-sis,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 in vivo.

miR-155/瘦素受体/AMPK轴在结核菌素诱导破骨细胞形成中的作用及机制

背景:破骨细胞异常活化在脊柱结核骨质破坏中起重要作用。在骨质疏松发病过程中,敲低miR-155通过增加瘦素受体的表达来激活磷酸腺苷依赖的蛋白激酶(AMP-dependent protein kinase,AMPK),进而抑制破骨细胞分化及骨吸收。但miR-155/瘦素受体/AMPK轴在脊柱结核骨质破坏中的作用尚不清楚。目的:研究miR-155/瘦素受体/AMPK轴在结核菌素诱导破骨细胞形成中的作用及机制。方法:培养单核巨噬细胞RAW264.7细胞,用不同浓度(1.0,2.5,5.0,10.0 IU/mL)结核菌素处理,转染阴性对照序列或miR-155抑制物、阴性对照siRNA序列或瘦素受体siRNA序列。采用抗酒石酸酸性磷酸酶染色检测破骨细胞数量,荧光定量PCR检测miR-155 mRNA表达,Western blot检测瘦素受体、p-AMPK蛋白表达,双荧光素酶报告基因验证miR-155靶向瘦素受体。结果与结论:①与对照组比较,2.5,5.0,10.0 IU/mL结核菌素组破骨细胞数量、miR-155 mRNA表达水平明显增加,瘦素受体、p-AMPK蛋白表达水平明显降低(P<0.05);②与阴性对照+5.0 IU/mL结核菌素组比较,miR-155抑制物+5.0 IU/mL结核菌素组破骨细胞数量、miR-155 mRNA表达水平明显降低,瘦素受体、p-AMPK蛋白表达水平明显增加(P<0.05);③与阴性对照组比较,miR-155抑制物组瘦素受体野生型双荧光素酶报告基因的荧光活力增加,miR-155模拟物组瘦素受体野生型双荧光素酶报告基因的荧光活力降低(P<0.05);④与阴性对照siRNA+miR-155抑制物+5.0 IU/mL结核菌素组比较,瘦素受体siRNA+miR-155抑制物+5.0 IU/mL结核菌素组miR-155 mRNA表达水平无明显变化(P>0.05),破骨细胞数量明显增加,瘦素受体、p-AMPK蛋白表达水平明显降低(P<0.05);⑤结果表明,结核菌素通过增加miR-155表达抑制下游瘦素受体表达及AMPK激活,进而诱导破骨细胞形成。

瘦素受体基因rs1137101位点多态性与老年人群代谢相关脂肪性肝病发生风险的关系研究

目的探讨瘦素受体(LEPR)基因rs1137101位点多态性与老年人代谢相关脂肪性肝病(MAFLD)发病风险的关系。方法2020年1月—2021年9月于北京市门头沟社区招募健康体检的1019例老年志愿者,其中MAFLD组569例、非MAFLD组450例。记录受试者的临床资料,基因芯片法检测LEPR-rs1137101多态性基因分型。Logistic回归分析评估基因多态性与MAFLD发生的关系。结果老年人群MAFLD患者携带rs1137101 G>A多态性较非MAFLD患者多(36.91%vs 24.00%,P<0.05)。携带LEPR-rs1137101 A等位基因与MAFLD的发生风险增加有关(OR=1.695,95%CI:1.1402.520,P<0.05)。结论老年人群LEPR-rs1137101 A基因可能与MAFLD的发生有关。

The effect ofthe leptin and its receptorexpression in CRF rat by the Reinforcing Kidney and Exhausting ToxinMixture

Objective:To investigate the adjusting malnutrition mechanism by the Reinforcing Kidney and Exhausting Toxic Mixture(REM)on the chronic renal failure (CRF) rat.Methods:60 wistar rats weved ivided into 3 groups randomly :the normal controc group(group Ⅰ),CRF group(group Ⅱ),and CRF rat perfusingwithREM group(group Ⅲ). Taking theirfat,kidneytissuefor detecting the protein expression of the leptin,leptin receptor(Ob-R) by the means ofimmunohistochemistry.Result:Comparing with control group, the leptinprotein express intensely in CRF rat ; In kidney tissue,the ob-R express weakly. After perfusing the REM ,comparing with CRF groupthe renal ob-R express strongly than CRF group. Conclusion: Maybe the REM could do a little better with the malnutritionof CRFratsby adjusttingthe activity of ob-R in kidney.

瘦素受体基因Gln223Arg单核苷酸多态性与精液质量参数的相关性研究

目的探讨瘦素受体(LEPR)基因Gln223Arg单核苷酸多态性与精液质量参数的相关性。方法选取2021年1月至12月在甘肃省妇幼保健院进行育前检查的肥胖男性156人作为观察组,另选取非肥胖男性150人作为对照组。检测LEPR基因Gln223Arg基因型,分析LEPR基因Gln223Arg多态性在两组间的分布及差异,分析基因型与精液质量各参数变化的相互关系。结果G/G型基因携带人群较A/A、A/G型携带人群发生精子密度、活力、畸形率、DFI异常的风险分别提高了1.21、2.36、1.68、1.85倍。结论LEPR基因Gln223Arg多态性可能造成男性发生肥胖的风险增加,G型等位基因较A型等位基因可能更容易造成精子质量异常的发生。

长型Leptin(瘦素)受体mRNA在大鼠消化道中的表达

本试验以 5只 SD雌性大鼠为研究对象 ,采用原位杂交技术研究了大鼠消化道长型 Leptin (瘦素 )受体 m RNA的表达及其分布。结果表明 ,长型 Leptin受体 m RNA在大鼠胃和十二指肠的粘膜及粘膜下层组织中广泛表达 ,从而证明了在大鼠消化道存在长型

蓝塘猪和长白猪leptin和leptin受体基因表达的变化

用实时荧光定量PCR方法研究了蓝塘猪和长白猪1、27、90、150和180日龄阶段脂肪组织中leptin基因mRNA和下丘脑中leptin受体基因mRNA的变化,并对2个品种不同生长阶段血液中leptin含量的变化规律进行了探讨。结果表明:(1)蓝塘猪180日龄时皮下脂肪中leptin基因表达量显著高于其它各阶段,而与长白猪相比,蓝塘猪除1日龄低于长白猪外,其它各个阶段均高于长白猪,180日龄两者差异极显著;长白猪各阶段间差异不显著;(2)蓝塘猪180日龄时下丘脑中leptin受体基因的表达量显著高于其它各阶段,长白猪180日龄时最高,且显著高于1日龄和27日龄,蓝塘猪与长白猪1日龄时差异显著;(3)蓝塘猪血清中leptin浓度各阶段均高于长白猪,两品种均是150日龄时最高,蓝塘猪150日龄显著高于27日龄和180日龄,长白猪各阶段差异不显著。