[ Objective] To clone and analyze the sequence of Adiponectin receptor 1 （ AdipoR1 ） and receptor 2 （AdipoR2） cDNA of Guangxi Bama mini-pig. [Method] The Adiponectin receptors cDNAs were amplified by RT-PCR using ...[ Objective] To clone and analyze the sequence of Adiponectin receptor 1 （ AdipoR1 ） and receptor 2 （AdipoR2） cDNA of Guangxi Bama mini-pig. [Method] The Adiponectin receptors cDNAs were amplified by RT-PCR using skeletal muscle total RNA as template and then ligated into pMD18-T vector after purification. The recombinant pMD18-T vector was transformed into the E. coil DH5α for identification and sequencing. And the results were compared with the cDNA sequence from other species. [Result] The fragments, 1 128 bp and 1 161 bp in size, were amplified by RT-PCR and respectively consistent with the coding sequence of AdipoR1 gene and AdipoR2 gene. The homology analysis showed that the sequences of AdipoR1 gene and AdipoR2 gene were respectively 99.8% and 99.7% homologous to the sequence of domestic pig reported in GenBank with one base and three base missense mutations correspondingly. [ Conclusion] The AdipoR1 gene and AdipoR2. gene were successfully amplified from Guangxi Bama mini-pig, laying the foundation for the further study of the biological function of AdipoR genes and the design of novel drugs with AdipoR as target.展开更多
In eukaryotic cells, receptor endocytosis is a key event regulating signaling transduction. Adiponectin receptors belong to a new receptor family that is distinct from G-protein-coupled receptors and has critical role...In eukaryotic cells, receptor endocytosis is a key event regulating signaling transduction. Adiponectin receptors belong to a new receptor family that is distinct from G-protein-coupled receptors and has critical roles in the pathogenesis of diabetes and metabolic syndrome. Here, we analyzed the endocytosis of adiponectin and adiponectin receptor 1 （AdipoR1） and found that they are both internalized into transferrin-positive compartments that follow similar traffic routes. Blocking clathrin-mediated endocytosis by expressing Eps15 mutants or depleting K^＋ trapped AdipoR1 at the plasma membrane, and K^＋ depletion abolished adiponectin internalization, indicating that the endocytosis of AdipoR1 and adiponectin is clathrin-dependent. Depletion of K^＋ and overexpression of Eps15 mutants enhance adiponectin- stimulated AMP-activated protein kinase phosphorylation, suggesting that the endocytosis of AdipoR1 might down-regulate adiponectin signaling. In addition, AdipoR1 colocalizes with the small GTPase Rab5, and a dominant negative Rab5 abrogates AdipoR1 endocytosis. These data indicate that AdipoR1 is internalized through a clathrin- and Rab5- dependent pathway and that endocytosis may play a role in the regulation of adiponectin signaling.展开更多
In order to confirm whether the mRNA levels of adiponectin in adipose tissue and mRNA levels of AdipoR1 in the skeletal muscles were correlated with the serum parameters of glucose and lipid metabolism and to clarify ...In order to confirm whether the mRNA levels of adiponectin in adipose tissue and mRNA levels of AdipoR1 in the skeletal muscles were correlated with the serum parameters of glucose and lipid metabolism and to clarify the regulation of adiponectin receptor gene expression in diabetic states, serum adiponectin, mRNA levels of adiponectin in adipose tissue and mRNA levels of AdipoR1 in the skeletal muscles were examined in type 2 diabetic rats. The model of type 2 diabetes was prepared by feeding high fat diet and injecting low dosage of streptozotocin (STZ). The diabetic rats were screened out by oral glucose tolerance test. One group of type 2 diabetic rats received rosiglitazone. The serum adiponectin concentration was detected by using ELISA and mRNA levels were examined by RT-PCR. The serum adiponectin levels and mRNA levels of adiponectin in adipose tissue of type 2 diabetic rats were significantly decreased as compared with the normal control rats (P<0.05, P<0.01 respectively). No siglificant changes were observed in the expression of adiponectin receptor 1 in the skeletal muscle of type 2 diabetic rats. The mRNA levels of adiponectin in adipose tissue were reversely correlated with serum insulin (r=-0.66, P<0.05), triglyceride (r=-0.58, P<0.05), cholesterol (r=-0.49, P<0.05), interleukin-6 (r=-0.49, P<0.05) and tumor necrosis factor (r=-0.43, P<0.05). The expression of adiponectin receptors was not altered in the skeletal muscle of Type 2 diabetic rats. The decreased serum adiponectin was caused by the decreased expression of adiponectin mRNA in adipose tissue rather than the adiponectin receptors in the skeletal muscle, which could be improved by rosiglitazone.展开更多
Background The genes encoding adiponectin receptor 1 （ADIPOR1） and small ubiquitin-like modifier 4 （SUM04） have been linked to anti-atherogenic effects, but little is known about whether polymorphisms in the two g...Background The genes encoding adiponectin receptor 1 （ADIPOR1） and small ubiquitin-like modifier 4 （SUM04） have been linked to anti-atherogenic effects, but little is known about whether polymorphisms in the two genes, acting separately or interacting, affect risk of coronary artery disease （CAD） without diabetes. Methods We genotyped 200 CAD patients without diabetes and 200 controls without CAD or diabetes at three single-nucleotide polymorphisms （SNPs） in ADIPOR1 and one SNP in SUM04, which were chosen based on previous studies. Potential associations were also explored between these SNPs and clinical characteristics of CAD without diabetes. Results Risk alleles at three SNPs inADIPOR1 （rs7539542-G, rs7514221-C and rs3737884-G） and the G allele at SNP rs237025 in SUM04 significantly increased risk of CAD without diabetes, with ORs ranging from 1.79 to 4.44. Carriers of any of these four risk alleles showed similar adverse clinical characteristics. Compared with individuals with a CC or GC genotype, those with a GG genotype at rs3737884 were at significantly higher risk of CAD that affected the left anterior descending coronary artery （OR： 6.77, P = 0.009）, the right coronary artery （OR： 4.81, P = 0.028） or a relatively large number of vessels （P = 0.04）. Individuals carrying a risk allele at one or more of the three SNPs in ADIPOR1 as well as a risk allele at the SNP in SUM04 were at significantly higher risk of CAD without diabetes than individuals not carrying any risk alleles （OR： 5.82, 95% CI： 1.23-27.7, P= 0.013）. Conelusions SNPs in ADIPORl and SUMO4 are associated with elevated risk of CAD without diabetes, and SNPs in the two genes may interact to jointly affect disease risk.展开更多
Alzheimer's disease is the primary cause of dementia and imposes a significant socioeconomic burden globally.Physical exercise,as an effective strategy for improving general health,has been largely reported for it...Alzheimer's disease is the primary cause of dementia and imposes a significant socioeconomic burden globally.Physical exercise,as an effective strategy for improving general health,has been largely reported for its effectiveness in slowing neurodegeneration and increasing brain functional plasticity,particularly in aging brains.However,the underlying mechanisms of exercise in cognitive aging remain largely unclear.Adiponectin,a cell-secreted protein hormone,has recently been found to regulate synaptic plasticity and mediate the antidepressant effects of physical exercise.Studies on the neuroprotective effects of adiponectin have revealed potential innovative treatments for Alzheimer's disease.Here,we reviewed the functions of adiponectin and its receptor in the brains of human and animal models of cognitive impairment.We summarized the role of adiponectin in Alzheimer's disease,focusing on its impact on energy metabolism,insulin resistance,and inflammation.We also discuss how exercise increases adiponectin secretion and its potential benefits for learning and memory.Finally,we highlight the latest research on chemical compounds that mimic exerciseenhanced secretion of adiponectin and its receptor in Alzheimer's disease.展开更多
AIM： To determine circulating and hepatic adiponectin in rodents with fatty liver disease or liver cirrhosis and investigate expression of the adiponectin receptors AdipoR1 on the mRNA and protein level and AdipoR2 o...AIM： To determine circulating and hepatic adiponectin in rodents with fatty liver disease or liver cirrhosis and investigate expression of the adiponectin receptors AdipoR1 on the mRNA and protein level and AdipoR2 on the mRNA level. METHODS： Fat fed rats were used as a model for fatty liver disease and bile duct ligation in mice to investigate cirrhotic liver. Expression of AdipoR1 and AdipoR2 mRNA was determined by real time RT-PCR. AdipoR1 protein was analysed by immunoblot. Adiponectin was measured by ELISA. RESULTS： Systemic adiponectin is reduced in fatfed rats but is elevated in mice after bile duct ligation （BDL）. Hepatic adiponectin protein is lower in steatotic liver but not in the liver of BE）L-mice when compared to controls. Adiponectin mRNA was not detected in human liver samples or primary human hepatocytes nor in rat liver but recombinant adiponectin is taken up by isolated hepatocytes in-vitro. AdipoR1 mRNA and AdipoR1 protein levels are similar in the liver tissue of control and fat fed animals whereas AdipoR2 mRNA is induced. AdipoR2 mRNA and AdipoR1 mRNA and protein is suppressed in the liver of BDL-mice. CONCLUSION： Our studies show reduced circulating adiponectin in a rat model of fatty liver disease whereas circulating adiponectin is elevated in a mouse model of cirrhosis and similar findings have been described in humans. Diminished hepatic expression of adiponectin receptors was only found in liver cirrhosis.展开更多
Background Endothelial dysfunction is a key event in the onset and progression of atherosclerosis in diabetic patients. Apoptosis may lead to endothelial dysfunction and contribute to vascular complications. However, ...Background Endothelial dysfunction is a key event in the onset and progression of atherosclerosis in diabetic patients. Apoptosis may lead to endothelial dysfunction and contribute to vascular complications. However, no study has addressed apoptosis in human umbilical vein endothelial cells （HUVECs） induced by an intermittent high-glucose media and its association with adiponectin receptor 1 （adipoR1）, adipoR2, or adenosine monophosphate （AMP）-activated protein kinase （AMPK）. Methods HUVECs were cultured in continuous normal glucose （5.5 mmol/L）, continuous high glucose （25 mmol/L）, alternating normal and high glucose and mannitol. In the alternating normal and high-glucose media, HUVECs were treated under different conditions. First, cells were transfected with the adipoRl-specific small-interfering RNA （siRNA） and then stimulated with globular adiponectin （gAD）. Second, cells were cultured in both gAD and the AMPK activator 5-aminoimidazole-4-carboxamide-l-13-D-ribofuranoside （AICAR）. Third, cells were cultured in the AMPK inhibitor adenine-9-13-D-arabino-furanoside （araA）, gAD, and in AICAR. Results HUVEC apoptosis increased more significantly in an intermittent high-glucose medium than in a constant high-glucose medium. HUVEC apoptosis induced by an intermittent high-glucose medium was inhibited when the cells were pretreated with 3 pg/ml gAD, which rapidly activated AMPK and adipoR1 in HUVECs. However, adipoR2 was not activated. Conclusions We found that adipoR1, not adipoR2, is involved in mediating intermittent high-concentration glucose- evoked apoptosis in endothelial cells, gAD activated AMPK through adipoR1, leads to the partial inhibition of HUVEC apoptosis. A fluctuating glucose medium is more harmful than a constant high-glucose medium to endothelial cells.展开更多
Psychological depression is drawing accumulating attention nowadays, due to the skyrocketing incidence worldwide and the enormous burdens it incurs. Physical exercise has been long recog- nized for its therapeutic eff...Psychological depression is drawing accumulating attention nowadays, due to the skyrocketing incidence worldwide and the enormous burdens it incurs. Physical exercise has been long recog- nized for its therapeutic effects on depressive disorders, although knowledge of the underlying mechanisms remains limited. Suppressed hippocampal neurogenesis in adult brains has been regarded, at least partly, contributive to depression, whereas physical exercise that restores neuro- genesis accordingly exerts the anti-depressive action. Several recent publications have suggested the potential role of adiponectin, a protein hormone secreted by peripheral mature adipocytes, in mediating physical exercise-triggered enhancement of hippocampal neurogenesis and alleviation of depression. Here, we briefly review these novel findings and discuss the possibility of counter- acting depression by modulating adiponectin signaling in the hippocampus with interventions including physical exercise and administration of pharmacological agents.展开更多
AIM To investigate whether the adipocytes derived hormone adiponectin(ADPN) affects the mechanical responses in strips from the mouse gastric fundus. METHODS For functional experiments, gastric strips from the fundal ...AIM To investigate whether the adipocytes derived hormone adiponectin(ADPN) affects the mechanical responses in strips from the mouse gastric fundus. METHODS For functional experiments, gastric strips from the fundal region were cut in the direction of the longitudinal muscle layer and placed in organ baths containing KrebsHenseleit solution. Mechanical responses were recorded via force-displacement transducers, which were coupled to a polygraph for continuous recording of isometric tension. Electrical field stimulation(EFS) was applied via two platinum wire rings through which the preparation was threaded. The effects of ADPN were investigated on the neurally-induced contractile and relaxant responses elicited by EFS. The expression of ADPN receptors, Adipo-R1 and Adipo-R2, was also evaluated by touchdown-PCR analysis. RESULTS In the functional experiments, EFS(4-16 Hz) elicited tetrodotoxin(TTX)-sensitive contractile responses. Addition of ADPN to the bath medium caused a reduction in amplitude of the neurally-induced contractile responses(P < 0.05). The effects of ADPN were no longer observed in the presence of the nitric oxide(NO) synthesis inhibitor L-NG-nitro arginine(L-NNA)(P > 0.05). The direct smooth muscle response to methacholine was not influenced by ADPN(P > 0.05). In carbachol precontracted strips and in the presence of guanethidine, EFS induced relaxant responses. Addition of ADPN to the bath medium, other than causing a slight and progressive decay of the basal tension, increased the amplitude of the neurally-induced relaxant responses(P < 0.05). Touchdown-PCR analysis revealed the expression of both Adipo-R1 and Adipo-R2 in the gastric fundus.CONCLUSION The results indicate for the first time that ADPN is able to influence the mechanical responses in strips from the mouse gastric fundus.展开更多
Pancreatic ductal adenocarcinoma (PDAC) is the fourth cause of cancer death with an overall survival of 5% at five years. The development of PDAC is characteristically associated to the accumulation of distinctive gen...Pancreatic ductal adenocarcinoma (PDAC) is the fourth cause of cancer death with an overall survival of 5% at five years. The development of PDAC is characteristically associated to the accumulation of distinctive genetic mutations and is preceded by the exposure to several risk factors. Epidemiology has demonstrated that PDAC risk factors may be non-modifiable risks (sex, age, presence of genetic mutations, ethnicity) and modifiable and co-morbidity factors related to the specific habits and lifestyle. Recently it has become evident that obesity and diabetes are two important modifiable risk factors for PDAC. Obesity and diabetes are complex systemic and intertwined diseases and, over the years, experimental evidence indicate that insulin-resistance, alteration of adipokines, especially leptin and adiponectin, oxidative stress and inflammation may play a role in PDAC. Peroxisome proliferator activated receptor-γ (PPARγ) is a nuclear receptor transcription factor that is implicated in the regulation of metabolism, differentiation and inflammation. PPARγ is a key regulator of adipocytes differentiation, regulates insulin and adipokines production and secretion, may modulate inflammation, and it is implicated in PDAC. PPARγ agonists are used in the treatment of diabetes and oxidative stress-associated diseases and have been evaluated for the treatment of PDAC. PPARγ is at the cross-road of diabetes, obesity, and PDAC and it is an interesting target to pharmacologically prevent PDAC in obese and diabetic patients.展开更多
AIM: To explore the therapeutic role of globular adiponectin (gAd) in high-fat diet/streptozotocin (STZ)-induced type 2 diabetic rats with nonalcoholic fatty liver disease (NAFLD).
Background: While the various antitumororal activities of adiponectin as an adipocyte-derived hormone well studied, it is speculated that there is a crosstalk between adiponectin and esterogen receptor (ER) signaling....Background: While the various antitumororal activities of adiponectin as an adipocyte-derived hormone well studied, it is speculated that there is a crosstalk between adiponectin and esterogen receptor (ER) signaling. To test this hypothesis we evaluate the possible correlation between serum level of adiponectin with two estrogen receptors (ERα and ERβ) gene expression in breast cancer patients. Methods: In this case-control study, 70 women with breast cancer participated with different grades of obesity (36 none obese, BMI 2 and 34 obese, BMI ≥ 25 kg/m2).The mean age of Participants was 44.53 yr ± 1.79 yr (21 yr - 70 yr) .Serum level of adiponectin determined by ELISA. Following quantitative expression of estrogen receptors mRNA in tumor tissues was evaluated by Real-time PCR. Results: We find a significant reverse correlation between serum level of Adiponectin and ERα mRNA (r = –0.229, n = 64, p = 0.035) but no correlation was between adiponectin and ERβ in samples (p = 0.228). The lower adiponectin multiplied the odds of having higher ERα mRNA level by a factor of OR = 4.33, 1.28 - 14.6, 95% confidence interval (CI) as compared with those that displayed a moderate or higher serum level of adiponectin (>7.02 ng/ml). The same odds for next estrogen receptor, ERβ, was not greater than unity (OR = 0.31, 0.06 - 1.56, 95% CI). Conclusion: According to the obtained results, it is speculated that as adiponectin can affect ERs gene expression, so affecting the steroid receptor signaling can be proposed as a new underling mechanism of action for this adipokine in breast cancer pathogenesis especially in obese ones.展开更多
基金Supported by Guangxi Science Foundation (0542025)~~
文摘[ Objective] To clone and analyze the sequence of Adiponectin receptor 1 （ AdipoR1 ） and receptor 2 （AdipoR2） cDNA of Guangxi Bama mini-pig. [Method] The Adiponectin receptors cDNAs were amplified by RT-PCR using skeletal muscle total RNA as template and then ligated into pMD18-T vector after purification. The recombinant pMD18-T vector was transformed into the E. coil DH5α for identification and sequencing. And the results were compared with the cDNA sequence from other species. [Result] The fragments, 1 128 bp and 1 161 bp in size, were amplified by RT-PCR and respectively consistent with the coding sequence of AdipoR1 gene and AdipoR2 gene. The homology analysis showed that the sequences of AdipoR1 gene and AdipoR2 gene were respectively 99.8% and 99.7% homologous to the sequence of domestic pig reported in GenBank with one base and three base missense mutations correspondingly. [ Conclusion] The AdipoR1 gene and AdipoR2. gene were successfully amplified from Guangxi Bama mini-pig, laying the foundation for the further study of the biological function of AdipoR genes and the design of novel drugs with AdipoR as target.
文摘In eukaryotic cells, receptor endocytosis is a key event regulating signaling transduction. Adiponectin receptors belong to a new receptor family that is distinct from G-protein-coupled receptors and has critical roles in the pathogenesis of diabetes and metabolic syndrome. Here, we analyzed the endocytosis of adiponectin and adiponectin receptor 1 （AdipoR1） and found that they are both internalized into transferrin-positive compartments that follow similar traffic routes. Blocking clathrin-mediated endocytosis by expressing Eps15 mutants or depleting K^＋ trapped AdipoR1 at the plasma membrane, and K^＋ depletion abolished adiponectin internalization, indicating that the endocytosis of AdipoR1 and adiponectin is clathrin-dependent. Depletion of K^＋ and overexpression of Eps15 mutants enhance adiponectin- stimulated AMP-activated protein kinase phosphorylation, suggesting that the endocytosis of AdipoR1 might down-regulate adiponectin signaling. In addition, AdipoR1 colocalizes with the small GTPase Rab5, and a dominant negative Rab5 abrogates AdipoR1 endocytosis. These data indicate that AdipoR1 is internalized through a clathrin- and Rab5- dependent pathway and that endocytosis may play a role in the regulation of adiponectin signaling.
文摘In order to confirm whether the mRNA levels of adiponectin in adipose tissue and mRNA levels of AdipoR1 in the skeletal muscles were correlated with the serum parameters of glucose and lipid metabolism and to clarify the regulation of adiponectin receptor gene expression in diabetic states, serum adiponectin, mRNA levels of adiponectin in adipose tissue and mRNA levels of AdipoR1 in the skeletal muscles were examined in type 2 diabetic rats. The model of type 2 diabetes was prepared by feeding high fat diet and injecting low dosage of streptozotocin (STZ). The diabetic rats were screened out by oral glucose tolerance test. One group of type 2 diabetic rats received rosiglitazone. The serum adiponectin concentration was detected by using ELISA and mRNA levels were examined by RT-PCR. The serum adiponectin levels and mRNA levels of adiponectin in adipose tissue of type 2 diabetic rats were significantly decreased as compared with the normal control rats (P<0.05, P<0.01 respectively). No siglificant changes were observed in the expression of adiponectin receptor 1 in the skeletal muscle of type 2 diabetic rats. The mRNA levels of adiponectin in adipose tissue were reversely correlated with serum insulin (r=-0.66, P<0.05), triglyceride (r=-0.58, P<0.05), cholesterol (r=-0.49, P<0.05), interleukin-6 (r=-0.49, P<0.05) and tumor necrosis factor (r=-0.43, P<0.05). The expression of adiponectin receptors was not altered in the skeletal muscle of Type 2 diabetic rats. The decreased serum adiponectin was caused by the decreased expression of adiponectin mRNA in adipose tissue rather than the adiponectin receptors in the skeletal muscle, which could be improved by rosiglitazone.
基金Acknowledgments This study was funded by the National Natural Science Foundation of China （81570323, 30972709, 81061120527, 81241082） and the 12th Five-Year National Program of the Ministry of Scientific Technology （2012BAI10B01）. We thank Liu M and Zhou L from Beijing Hospital for providing experimental data, the nurses from Beijing Anzhen Hospital for collecting specimens, and the study volunteers.
文摘Background The genes encoding adiponectin receptor 1 （ADIPOR1） and small ubiquitin-like modifier 4 （SUM04） have been linked to anti-atherogenic effects, but little is known about whether polymorphisms in the two genes, acting separately or interacting, affect risk of coronary artery disease （CAD） without diabetes. Methods We genotyped 200 CAD patients without diabetes and 200 controls without CAD or diabetes at three single-nucleotide polymorphisms （SNPs） in ADIPOR1 and one SNP in SUM04, which were chosen based on previous studies. Potential associations were also explored between these SNPs and clinical characteristics of CAD without diabetes. Results Risk alleles at three SNPs inADIPOR1 （rs7539542-G, rs7514221-C and rs3737884-G） and the G allele at SNP rs237025 in SUM04 significantly increased risk of CAD without diabetes, with ORs ranging from 1.79 to 4.44. Carriers of any of these four risk alleles showed similar adverse clinical characteristics. Compared with individuals with a CC or GC genotype, those with a GG genotype at rs3737884 were at significantly higher risk of CAD that affected the left anterior descending coronary artery （OR： 6.77, P = 0.009）, the right coronary artery （OR： 4.81, P = 0.028） or a relatively large number of vessels （P = 0.04）. Individuals carrying a risk allele at one or more of the three SNPs in ADIPOR1 as well as a risk allele at the SNP in SUM04 were at significantly higher risk of CAD without diabetes than individuals not carrying any risk alleles （OR： 5.82, 95% CI： 1.23-27.7, P= 0.013）. Conelusions SNPs in ADIPORl and SUMO4 are associated with elevated risk of CAD without diabetes, and SNPs in the two genes may interact to jointly affect disease risk.
基金supported by the National Natural Science Foundation of China,No.82072529(to HWHT)Key Laboratory of Guangdong Higher Education Institutes,No.2021KSYS009(to HWHT)the China Postdoctoral Science Foundation,No.2022M720907(to HHG)。
文摘Alzheimer's disease is the primary cause of dementia and imposes a significant socioeconomic burden globally.Physical exercise,as an effective strategy for improving general health,has been largely reported for its effectiveness in slowing neurodegeneration and increasing brain functional plasticity,particularly in aging brains.However,the underlying mechanisms of exercise in cognitive aging remain largely unclear.Adiponectin,a cell-secreted protein hormone,has recently been found to regulate synaptic plasticity and mediate the antidepressant effects of physical exercise.Studies on the neuroprotective effects of adiponectin have revealed potential innovative treatments for Alzheimer's disease.Here,we reviewed the functions of adiponectin and its receptor in the brains of human and animal models of cognitive impairment.We summarized the role of adiponectin in Alzheimer's disease,focusing on its impact on energy metabolism,insulin resistance,and inflammation.We also discuss how exercise increases adiponectin secretion and its potential benefits for learning and memory.Finally,we highlight the latest research on chemical compounds that mimic exerciseenhanced secretion of adiponectin and its receptor in Alzheimer's disease.
基金Supported by a grant from the Deutsche Forschungsgemeinschaft (BU 1141/3-2)
文摘AIM： To determine circulating and hepatic adiponectin in rodents with fatty liver disease or liver cirrhosis and investigate expression of the adiponectin receptors AdipoR1 on the mRNA and protein level and AdipoR2 on the mRNA level. METHODS： Fat fed rats were used as a model for fatty liver disease and bile duct ligation in mice to investigate cirrhotic liver. Expression of AdipoR1 and AdipoR2 mRNA was determined by real time RT-PCR. AdipoR1 protein was analysed by immunoblot. Adiponectin was measured by ELISA. RESULTS： Systemic adiponectin is reduced in fatfed rats but is elevated in mice after bile duct ligation （BDL）. Hepatic adiponectin protein is lower in steatotic liver but not in the liver of BE）L-mice when compared to controls. Adiponectin mRNA was not detected in human liver samples or primary human hepatocytes nor in rat liver but recombinant adiponectin is taken up by isolated hepatocytes in-vitro. AdipoR1 mRNA and AdipoR1 protein levels are similar in the liver tissue of control and fat fed animals whereas AdipoR2 mRNA is induced. AdipoR2 mRNA and AdipoR1 mRNA and protein is suppressed in the liver of BDL-mice. CONCLUSION： Our studies show reduced circulating adiponectin in a rat model of fatty liver disease whereas circulating adiponectin is elevated in a mouse model of cirrhosis and similar findings have been described in humans. Diminished hepatic expression of adiponectin receptors was only found in liver cirrhosis.
文摘Background Endothelial dysfunction is a key event in the onset and progression of atherosclerosis in diabetic patients. Apoptosis may lead to endothelial dysfunction and contribute to vascular complications. However, no study has addressed apoptosis in human umbilical vein endothelial cells （HUVECs） induced by an intermittent high-glucose media and its association with adiponectin receptor 1 （adipoR1）, adipoR2, or adenosine monophosphate （AMP）-activated protein kinase （AMPK）. Methods HUVECs were cultured in continuous normal glucose （5.5 mmol/L）, continuous high glucose （25 mmol/L）, alternating normal and high glucose and mannitol. In the alternating normal and high-glucose media, HUVECs were treated under different conditions. First, cells were transfected with the adipoRl-specific small-interfering RNA （siRNA） and then stimulated with globular adiponectin （gAD）. Second, cells were cultured in both gAD and the AMPK activator 5-aminoimidazole-4-carboxamide-l-13-D-ribofuranoside （AICAR）. Third, cells were cultured in the AMPK inhibitor adenine-9-13-D-arabino-furanoside （araA）, gAD, and in AICAR. Results HUVEC apoptosis increased more significantly in an intermittent high-glucose medium than in a constant high-glucose medium. HUVEC apoptosis induced by an intermittent high-glucose medium was inhibited when the cells were pretreated with 3 pg/ml gAD, which rapidly activated AMPK and adipoR1 in HUVECs. However, adipoR2 was not activated. Conclusions We found that adipoR1, not adipoR2, is involved in mediating intermittent high-concentration glucose- evoked apoptosis in endothelial cells, gAD activated AMPK through adipoR1, leads to the partial inhibition of HUVEC apoptosis. A fluctuating glucose medium is more harmful than a constant high-glucose medium to endothelial cells.
基金Acknowledgment This research was supported by grants from the American Diabetes Association （1-11-JF56） and the Natural Science Foundation of China （30900592, 81170199） （to YJW） , and NIH （ HL-63828, HL-096686 ） and American Diabetes Association （7-11-BS-93） （to XLM）.
基金supported by Hong Kong Health and Medical Research FundLeading Talents of Guangdong(2013)+3 种基金Programme of Introducing Talents of Discipline to Universities(B14036)Project of International,as well as Hong Kong,Macao&Taiwan Science and Technology Cooperation Innovation Platform in Universities in Guangdong Province,China(2013gjhz0002)grants to Jinan University Guangdong-Hong Kong-Macao Cooperation and Innovation Center for Tissue Regeneration and RepairState Key Laboratory of Pharmaceutical Biotechnology,Hong Kong SAR,China
文摘Psychological depression is drawing accumulating attention nowadays, due to the skyrocketing incidence worldwide and the enormous burdens it incurs. Physical exercise has been long recog- nized for its therapeutic effects on depressive disorders, although knowledge of the underlying mechanisms remains limited. Suppressed hippocampal neurogenesis in adult brains has been regarded, at least partly, contributive to depression, whereas physical exercise that restores neuro- genesis accordingly exerts the anti-depressive action. Several recent publications have suggested the potential role of adiponectin, a protein hormone secreted by peripheral mature adipocytes, in mediating physical exercise-triggered enhancement of hippocampal neurogenesis and alleviation of depression. Here, we briefly review these novel findings and discuss the possibility of counter- acting depression by modulating adiponectin signaling in the hippocampus with interventions including physical exercise and administration of pharmacological agents.
基金the Florence University(No.RTD CO 090101010107 RICATEN14)Fondazione CRF(No.2017.0777)
文摘AIM To investigate whether the adipocytes derived hormone adiponectin(ADPN) affects the mechanical responses in strips from the mouse gastric fundus. METHODS For functional experiments, gastric strips from the fundal region were cut in the direction of the longitudinal muscle layer and placed in organ baths containing KrebsHenseleit solution. Mechanical responses were recorded via force-displacement transducers, which were coupled to a polygraph for continuous recording of isometric tension. Electrical field stimulation(EFS) was applied via two platinum wire rings through which the preparation was threaded. The effects of ADPN were investigated on the neurally-induced contractile and relaxant responses elicited by EFS. The expression of ADPN receptors, Adipo-R1 and Adipo-R2, was also evaluated by touchdown-PCR analysis. RESULTS In the functional experiments, EFS(4-16 Hz) elicited tetrodotoxin(TTX)-sensitive contractile responses. Addition of ADPN to the bath medium caused a reduction in amplitude of the neurally-induced contractile responses(P < 0.05). The effects of ADPN were no longer observed in the presence of the nitric oxide(NO) synthesis inhibitor L-NG-nitro arginine(L-NNA)(P > 0.05). The direct smooth muscle response to methacholine was not influenced by ADPN(P > 0.05). In carbachol precontracted strips and in the presence of guanethidine, EFS induced relaxant responses. Addition of ADPN to the bath medium, other than causing a slight and progressive decay of the basal tension, increased the amplitude of the neurally-induced relaxant responses(P < 0.05). Touchdown-PCR analysis revealed the expression of both Adipo-R1 and Adipo-R2 in the gastric fundus.CONCLUSION The results indicate for the first time that ADPN is able to influence the mechanical responses in strips from the mouse gastric fundus.
基金Supported by Fondo per gli Investimenti della Ricerca di BaseNo.RBAP10MY35_002+1 种基金Ente Cassa di Risparmio di Firenzeand Fior Gen ONLUS to Galli A
文摘Pancreatic ductal adenocarcinoma (PDAC) is the fourth cause of cancer death with an overall survival of 5% at five years. The development of PDAC is characteristically associated to the accumulation of distinctive genetic mutations and is preceded by the exposure to several risk factors. Epidemiology has demonstrated that PDAC risk factors may be non-modifiable risks (sex, age, presence of genetic mutations, ethnicity) and modifiable and co-morbidity factors related to the specific habits and lifestyle. Recently it has become evident that obesity and diabetes are two important modifiable risk factors for PDAC. Obesity and diabetes are complex systemic and intertwined diseases and, over the years, experimental evidence indicate that insulin-resistance, alteration of adipokines, especially leptin and adiponectin, oxidative stress and inflammation may play a role in PDAC. Peroxisome proliferator activated receptor-γ (PPARγ) is a nuclear receptor transcription factor that is implicated in the regulation of metabolism, differentiation and inflammation. PPARγ is a key regulator of adipocytes differentiation, regulates insulin and adipokines production and secretion, may modulate inflammation, and it is implicated in PDAC. PPARγ agonists are used in the treatment of diabetes and oxidative stress-associated diseases and have been evaluated for the treatment of PDAC. PPARγ is at the cross-road of diabetes, obesity, and PDAC and it is an interesting target to pharmacologically prevent PDAC in obese and diabetic patients.
基金Supported by Science and Technology Project of Xiamen,China,No.3502Z20114016
文摘AIM: To explore the therapeutic role of globular adiponectin (gAd) in high-fat diet/streptozotocin (STZ)-induced type 2 diabetic rats with nonalcoholic fatty liver disease (NAFLD).
文摘Background: While the various antitumororal activities of adiponectin as an adipocyte-derived hormone well studied, it is speculated that there is a crosstalk between adiponectin and esterogen receptor (ER) signaling. To test this hypothesis we evaluate the possible correlation between serum level of adiponectin with two estrogen receptors (ERα and ERβ) gene expression in breast cancer patients. Methods: In this case-control study, 70 women with breast cancer participated with different grades of obesity (36 none obese, BMI 2 and 34 obese, BMI ≥ 25 kg/m2).The mean age of Participants was 44.53 yr ± 1.79 yr (21 yr - 70 yr) .Serum level of adiponectin determined by ELISA. Following quantitative expression of estrogen receptors mRNA in tumor tissues was evaluated by Real-time PCR. Results: We find a significant reverse correlation between serum level of Adiponectin and ERα mRNA (r = –0.229, n = 64, p = 0.035) but no correlation was between adiponectin and ERβ in samples (p = 0.228). The lower adiponectin multiplied the odds of having higher ERα mRNA level by a factor of OR = 4.33, 1.28 - 14.6, 95% confidence interval (CI) as compared with those that displayed a moderate or higher serum level of adiponectin (>7.02 ng/ml). The same odds for next estrogen receptor, ERβ, was not greater than unity (OR = 0.31, 0.06 - 1.56, 95% CI). Conclusion: According to the obtained results, it is speculated that as adiponectin can affect ERs gene expression, so affecting the steroid receptor signaling can be proposed as a new underling mechanism of action for this adipokine in breast cancer pathogenesis especially in obese ones.
