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 l...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.展开更多
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&...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.展开更多
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...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.展开更多
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 int...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)difffuse-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 (x2 = 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.展开更多
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 pro...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.展开更多
To investigate the expression of mRNA of leptin long-form receptor(OB-Rb) in lu-teinized granulosa cells of obese women with polycystic ovary syndrome(PCOS),and to determine the role of leptin in the physiopathology o...To investigate the expression of mRNA of leptin long-form receptor(OB-Rb) in lu-teinized granulosa cells 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/m2,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 em-ployed for the detection of the expression of OB-RLmRNA in the luteinized granulosa cells.Our re-sults 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 pro-motes 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展开更多
Leptin is an adipokine that has been linked with the cardiovascular complications resulting from obesity such as hypertension and heart disease. Obese patients have high levels of circulating leptin due to increased f...Leptin is an adipokine that has been linked with the cardiovascular complications resulting from obesity such as hypertension and heart disease. Obese patients have high levels of circulating leptin due to increased fat mass. Clinical and population studies have correlated high levels of circulating leptin with the development of cardiac hypertrophy in obesity. Leptin has also been demonstrated to increase the growth of cultured cardiomyocytes. However, several animal studies of obese leptin deficient mice have not supported a role for leptin in promoting cardiac hypertrophy so the role of leptin in this pathological process remains unclear. Leptin is also an important hormone in the regulation of cardiac metabolism where it supports oxidation of glucose and fatty acids. In addition, leptin plays a critical role in protecting the heart from excess lipid accumulation and the formation of toxic lipids in obesity a condition known as cardiac lipotoxicity. This paper focuses on the data supporting and refuting leptin's role in promoting cardiac hypertrophy as well as its important role in the regulation of cardiac metabolism and protection against cardiac lipotoxicity.展开更多
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 randoml...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.展开更多
文摘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.
文摘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.
文摘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.
文摘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)difffuse-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 (x2 = 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.
文摘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.
文摘To investigate the expression of mRNA of leptin long-form receptor(OB-Rb) in lu-teinized granulosa cells 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/m2,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 em-ployed for the detection of the expression of OB-RLmRNA in the luteinized granulosa cells.Our re-sults 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 pro-motes 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
基金the National Heart,Lung and Blood Institute,Nos.PO1HL-051971 and R00HL112952the National Institute of General Medical Sciences,No.P20GM-104357the American Heart Association,No.14SDG20490339
文摘Leptin is an adipokine that has been linked with the cardiovascular complications resulting from obesity such as hypertension and heart disease. Obese patients have high levels of circulating leptin due to increased fat mass. Clinical and population studies have correlated high levels of circulating leptin with the development of cardiac hypertrophy in obesity. Leptin has also been demonstrated to increase the growth of cultured cardiomyocytes. However, several animal studies of obese leptin deficient mice have not supported a role for leptin in promoting cardiac hypertrophy so the role of leptin in this pathological process remains unclear. Leptin is also an important hormone in the regulation of cardiac metabolism where it supports oxidation of glucose and fatty acids. In addition, leptin plays a critical role in protecting the heart from excess lipid accumulation and the formation of toxic lipids in obesity a condition known as cardiac lipotoxicity. This paper focuses on the data supporting and refuting leptin's role in promoting cardiac hypertrophy as well as its important role in the regulation of cardiac metabolism and protection against cardiac lipotoxicity.
文摘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.
