Background:Drug resistance is the main factor contributing to cancer recurrence and poor prognosis.Exploration of drug resistance-related mechanisms and effective therapeutic targets are the aim of molecular targeted ...Background:Drug resistance is the main factor contributing to cancer recurrence and poor prognosis.Exploration of drug resistance-related mechanisms and effective therapeutic targets are the aim of molecular targeted therapy.In our study,the role of long non-coding RNA(lncRNA)AFAP1-AS1 in gemcitabine resistance and related mechanisms were explored in cervical cancer cells.Methods:Gemcitabine-resistant cervical cancer cell lines HT-3-Gem and SW756-Gem were constructed using the gemcitabine concentration gradient method.The overall survival rates and recurrence-free survival rates were evaluated by Kaplan-Meier analysis.The interaction was verified through a Dual-luciferase reporter gene assay and a Biotinylated RNA pull-down assay.Cell proliferation ability was assessed through methyl-thiazolyl-tetrazolium(MTT),soft agar,and colony formation experiments.Cell cycle and apoptosis were detected byflow cytometry.Results:Up-regulation of AFAP1-AS1 in cervical cancer predicted a poor prognosis.Besides,patients in the gemcitabine-resistance group had higher levels of AFAP1-AS1 than the gemcitabine-sensitive group.AFAP1-AS1 promoted tumor growth and induced gemcitabine tolerance of cervical cancer cells.In addition,AFAP1-AS1 mediated epidermal growth factor receptor(EGFR)expression by serving as a molecular sponge for microRNA-7a-5p(miR-7-5p).This present study also proved that the knockdown of EGFR or overexpression of miR-7a-5p abolished the accelerative role of AFAP1-AS1 overexpression in cancer progression and gemcitabine tolerance.Conclusions:In general,the AFAP1-AS1/miR-7-5p/EGFR axis was tightly related to the progression and gemcitabine tolerance of cervical cancer,providing potential targets for the management of cervical cancer.展开更多
BACKGROUND：Motoneurons from the Onuf’s nucleus of the spinal cord, which innervate the striated muscle of the pelvic floor, play an important role in erection, ejaculation, and urine control. Serotonin （5-hydroxytr...BACKGROUND：Motoneurons from the Onuf’s nucleus of the spinal cord, which innervate the striated muscle of the pelvic floor, play an important role in erection, ejaculation, and urine control. Serotonin （5-hydroxytryptamine, 5-HT） regulates motoneuron activity from the Onuf’s nucleus of the spinal cord. However, few studies exist that describe 5-HT receptor distribution in the Onuf’s nucleus. In addition, the nature of the effects of 5-HT receptor on the innervating striated muscle of the pelvic floor is controversial. OBJECTIVE： To investigate the distribution of serotonin 5-HT2A and 5-HT7 receptors in motoneurons of Onuf’s nucleus in the spinal cord of male rats, and to analyze the relationship of 5-HT2A and 5-HT7 receptor to central modulation of urogenital function. DESIGN, TIME AND SETTING： The neural morphology experiment was performed at the Ultramicro-structure Laboratory of Reproductive Medicine, Basic Medical College, Chongqing Medical University, China from April to December 2007. MATERIALS： Ten adult, Sprague Dawley rats （eight males and two females） were randomly divided into gender control group （n = 4, 50% male and 50% female） and a retrograde tracing group （n = 6, 100% male） Recombinant pseudorabies virus （PRV-152） was provided by Professor LW Enquist from Princeton University, USA. Rabbit anti-5-HT2A and 5-HT7 receptor antibodies were purchased from Diasorin, France. METHODS： In the gender control group, the spinal L5-6 segments were harvested, sliced, and then incubate antibodies specific against 5-HT2A or 5-HT7 receptors for immunohistochemical staining. In the retrograde tracing group, PRV-152 was separately injected into the right ischiocavernosus （ischiocavernosus subgroup, n = 3） and the right external urethral sphincter （external urethral sphincter subgroup, n = 3）. Four days after injection, L5-6 segments were harvested, sliced, and incubated with antibodies specific against 5-HT2A or 5-HT7 receptors for double-labeling immunofluorescence staining. MAIN OUTCOME MEASURES： Distribution analysis of 5-HT2A and 5-HT7 receptors in Onuf’s nucleus utilizing optical or laser confocal microscopy. RESULTS： 5-HT2A receptor immunoreactivity was revealed primarily in the medial region of the dorsolateral nucleus of Onuf’s nucleus. 5-HT7 receptor expression was observed in the lateral part of the dorso-lateral nucleus. 5-HT2A and 5-HT7 receptor expressions in the Onuf’s nucleus were significantly greater in male rats, compared to female rats. Double-labeling immunofluorescence demonstrated that 5-HT2A recepto were distributed primarily in the surrounding motoneurons innervating the ischiocavernosus, and 5-HT7 receptors were primarily expressed in motoneurons innervating the external urethral sphincter. CONCLUSION： Motoneurons innervating the ischiocavernosus and external urethral sphincter are located primarily in the medial and lateral region of the dorsolateral nucleus of L5-6 segments. The 5-HT2A receptor-innervating ischiocavernosus may be preferentially involved in the regulation of sexual reflex, and the 5-HT7 receptor-innervating external urethral sphincter may mainly join in regulating micturition reflex.展开更多
This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique...This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique. The results showed that: (1) The majority of examined neurons (78.70%) were sensitive to 5-HT (3–300 μmol/L). 5-HT induced inward currents in a concentration-dependent manner and the currents were blocked by ICS 205-930 (1 μmol/L), a selective antagonist of the 5-HT3 receptor; (2) Pre-application of WIN55,212-2 (0.01–1 μmol/L) significantly inhibited I5-HT3 reversibly in concentration-dependent and voltage-independent manners. The concentra-tion-response curve of 5-HT3 receptor was shifted downward by WIN55,212-2 without any change of the threshold value. The EC50 values of two curves were very close (17.5±4.5) mmol/L vs. (15.2±4.5) mmol/L and WIN55,212-2 decreased the maximal amplitude of I5-HT3 by (48.65±4.15)%; (3) Neither AM281, a selective CB1 receptor antagonist, nor AM630, a selective CB2 receptor antagonist reversed the inhibition of I5-HT3 by WIN55,212-2; (4) When WIN55,212-2 was given from 15 to 120 s before 5-HT application, inhibitory effect was gradually increased and the maximal inhibition took place at 90 s, and the inhibition remained at the same level after 90 s. We are led to concluded that-WIN55,212-2 inhibited I5-HT3 significantly and neither CB1 receptor antagonist nor CB2 receptor antagonist could reverse the inhibition of I5-HT3 by WIN55,212-2. Moreover, WIN55,212-2 is not an open channel blocker (OCB) of 5-HT3 receptor. WIN55,212-2 significantly inhibited 5-HT-activated currents in a non-competitive manner. The inhibition of I5-HT3 by WIN55,212-2 is probably new one of peripheral analgesic mechanisms of WIN55,212-2, but the mechanism by which WIN55,212-2 inhibits I5-HT3 warrants further investigation.展开更多
AIM:To study the effects of 5-hydroxytryptamine(5-HT)receptor antagonists on normal colonic motor activity in conscious dogs.METHODS:Colonic motor activity was recorded using a strain gauge force transducer in 5 dogs ...AIM:To study the effects of 5-hydroxytryptamine(5-HT)receptor antagonists on normal colonic motor activity in conscious dogs.METHODS:Colonic motor activity was recorded using a strain gauge force transducer in 5 dogs before and after 5-HT2B,5-HT3 and 5-HT4 receptor antagonist administration.The force transducers were implanted on the serosal surfaces of the gastric antrum,terminal ileum,ileocecal sphincter and colon.Test materials or vehicle alone was administered as an intravenous bolus injection during a quiescent period of the whole colon in the interdigestive state.The effects of these receptor antagonists on normal gastrointestinal motor activity were analyzed.RESULTS:5-HT2B,5-HT3 and 5-HT4 receptor antagonists had no contractile effect on the fasting canine terminal ileum.The 5-HT3 and 5-HT4 receptor antagonists inhibited phaseⅢof the interdigestive motor complex of the antrum and significantly inhibited colonic motor activity.In the proximal colon,the inhibitory effect was dose dependent.Dose dependency,however,was not observed in the distal colon.The 5-HT2B receptor antagonist had no contractile effect on normal colonic motor activity.CONCLUSION:The 5-HT3 and 5-HT4 receptor antagonists inhibited normal colonic motor activity.The5-HT2B receptor antagonist had no contractile effect on normal colonic motor activity.展开更多
AIM: To investigate cellular 5-HT4(-h/+h) receptor distribution, particularly in the epithelial layer, by laser mi-crodissection and polymerase chain reaction (PCR) in porcine gastrointestinal (GI) tissues. METHODS: A...AIM: To investigate cellular 5-HT4(-h/+h) receptor distribution, particularly in the epithelial layer, by laser mi-crodissection and polymerase chain reaction (PCR) in porcine gastrointestinal (GI) tissues. METHODS: A stepwise approach was used to evaluate RNA quality and to study cell-specific 5-HT4 receptor mRNA expression in the porcine gastric fundus and colon descendens. After freezing, staining and laser microdissection and pressure catapulting (LMPC), RNA quality was evaluated by the Experion automated electrophoresis system. 5-HT4 receptor and glyceral-dehyde-3-phosphate dehydrogenase (GAPDH) expressions were examined by endpoint reverse transcription (RT)-PCR in mucosal and muscle-myenteric plexus (MMP) tissue fractions, in mucosal and MMP parts of hematoxylin and eosin (HE) stained tissue sections andin microdissected patches of the epithelial and circular smooth muscle cell layer in these sections. Pig gastric fundus tissue sections were also stained immunohisto-chemically (IHC) for enterochromaffin cells (EC cells; MAB352); these cells were isolated by LMPC and examined by endpoint RT-PCR. RESULTS: After HE staining, the epithelial and circular smooth muscle cell layer of pig colon descendens and the epithelial cell layer of gastric fundus were identified morphologically and isolated by LMPC. EC cells of pig gastric fundus were successfully stained by IHC and isolated by LMPC. Freezing, HE and IHC staining, and LMPC had no influence on RNA quality. 5-HT4 recep-tor and GAPDH mRNA expressions were detected in mucosa and MMP tissue fractions, and in mucosal and MMP parts of HE stained tissue sections of pig colon descendens and gastric fundus. In the mucosa tissue fractions of both GI regions, the expression of h-exon containing receptor [5-HT4(+h) receptor] mRNA was significantly higher (P<0.01) compared to 5-HT4(-h) re-ceptor expression, and a similar trend was obtained in the mucosal part of HE stained tissue sections. Large microdissected patches of the epithelial and circular smooth muscle cell layer of pig colon descendens and of the epithelial cell layer of pig gastric fundus, also showed 5-HT4 receptor and GAPDH mRNA expression. No 5-HT4 receptor mRNA expression was detected in gastric LMPC-isolated EC cells from IHC stained tissues, which cells were positive for GAPDH. CONCLUSION: Porcine GI mucosa predominantly expresses 5-HT4(+h) receptor splice variants, suggesting their contribution to the 5-HT4 receptor-mediated mu-cosal effects of 5-HT.展开更多
Objective：To investigate the role of 5-HT7 receptor in the pathogenesis of irritable bowel syndrome（IBS）. Methods：Rat model of D-IBS was established by intracolonic instillation of acetic acid and restraint stress...Objective：To investigate the role of 5-HT7 receptor in the pathogenesis of irritable bowel syndrome（IBS）. Methods：Rat model of D-IBS was established by intracolonic instillation of acetic acid and restraint stress; Rat model of C-IBS was established by stomach irrigated with 0-4℃ cool water daily for 14 d. The content and distribution of 5-HT7 receptor at the brain and bowel was examined by immunohistochemistry and the expression of 5-HT7 receptor mRNA was detected by fluorescence quantitative RT-PCR（Real-time PCR）. Results：Immunocytochemistry result showed the 5-HT7 rceptor positive staining at hippocampus and hypothalamus of both C-IBS and D-IBS group was stronger than that of control group（P 〈 0.01）. The 5-HT7R expression at ileum, proximate colon, distal colon of C-IBS group was significantly stronger than that of control group（P 〈 0.05）. Realtime-PCR analysis results showed the expression level of 5-HT7 receptor at hippocampus and hypothalamus of both C-IBS and D-IBS group was increased than that of control group（P〈 0.05）. At proximal and distal colon of C-IBS group, the 5-HT7 receptor mRNA expression was increased compared with control group（P〈 0.05）. Conclusion：The up-regulated expression of 5-HT7 receptor at brain and colon may play an important role in the pathogenesis of C-IBS.展开更多
Hepatocytes were isolated from livers of adult male SpragueDawley rats and cultured in Williams'E Medium with 3 H thymidine. The effect of 5hydroxytryptamine (5HT) was investigated through adding various concentra...Hepatocytes were isolated from livers of adult male SpragueDawley rats and cultured in Williams'E Medium with 3 H thymidine. The effect of 5hydroxytryptamine (5HT) was investigated through adding various concentrations (10-810-3 mol/L) of 5HT to the hepatocyte cultures in the presence or absence of epidermal growth factor (EGF) and insulin. The involvement of 5HT2 receptor was examined by adding a 5HT2 receptor antagonist, ketanserin (10-6 mol/L), to some of the cultures containing 5HT. The increment of DNA synthesis was measured by 3 H thymidine incorporation. The results showed that 5HT2 (10-6 mol/L) significantly (P<005) increased the amount of DNA synthesis induced by EGF and insulin in the cultured adult rat hepaptocytes. The effect of 5HT in enhancing DNA synthesis began to appear at a concentration between 10-7 and 10-6 mol/L and reached maximum at concentrations of 10-4 mol/L. The enhancement of DNA synthesis by 5HT was significantly (P<005) antagonized by ketanserin, suggesting that this effect of 5HT was mediated by 5HT2 receptor subtype.展开更多
Alzheimer’s disease (AD) is a progressive neurological disorder primarily affecting new memory formation as well as retrieval of previously acquired memories. According to World Health Organization, current global po...Alzheimer’s disease (AD) is a progressive neurological disorder primarily affecting new memory formation as well as retrieval of previously acquired memories. According to World Health Organization, current global population suffering from cognitive impairment is estimated to 37 million. The number is projected to double in next one and half decade. Half of the population afflicted with dementia is represented by AD patients. Current therapies, which provide marginal symptomatic relief to AD patients, are effective only in half of the patient population. In depth understanding of the molecular mechanism of the disease is urgently required to develop more effective therapies. Therapies in clinical development may either offer symptomatic relief to patients or provide pure disease modifications, thus limiting benefit to patients. 5-HT4 receptor agonists offer an attractive option for the treatment of AD patients. Activation of 5- HT4 receptor under preclinical conditions is demonstrated to improve neurotransmission and enhance the release of acetylcholine resulting in the memory formation. In various cell based and animal models, partial 5-HT4 receptor agonists are demonstrated to promote the release of soluble amyloid precursor protein alpha and block the release of amyloid beta peptide offering suitable candidates as disease modification agents. Remarkably, 5-HT4 receptor agonists are also reported to induce neurogenesis in hippocampus as well as enteric system through the activation of cyclic AMP response element binding protein in rodents. Taken together, 5-HT4 agonists address all major facets of Alzheimer’s disease and may provide therapeutic potential for other neurological disorders.展开更多
文摘Background:Drug resistance is the main factor contributing to cancer recurrence and poor prognosis.Exploration of drug resistance-related mechanisms and effective therapeutic targets are the aim of molecular targeted therapy.In our study,the role of long non-coding RNA(lncRNA)AFAP1-AS1 in gemcitabine resistance and related mechanisms were explored in cervical cancer cells.Methods:Gemcitabine-resistant cervical cancer cell lines HT-3-Gem and SW756-Gem were constructed using the gemcitabine concentration gradient method.The overall survival rates and recurrence-free survival rates were evaluated by Kaplan-Meier analysis.The interaction was verified through a Dual-luciferase reporter gene assay and a Biotinylated RNA pull-down assay.Cell proliferation ability was assessed through methyl-thiazolyl-tetrazolium(MTT),soft agar,and colony formation experiments.Cell cycle and apoptosis were detected byflow cytometry.Results:Up-regulation of AFAP1-AS1 in cervical cancer predicted a poor prognosis.Besides,patients in the gemcitabine-resistance group had higher levels of AFAP1-AS1 than the gemcitabine-sensitive group.AFAP1-AS1 promoted tumor growth and induced gemcitabine tolerance of cervical cancer cells.In addition,AFAP1-AS1 mediated epidermal growth factor receptor(EGFR)expression by serving as a molecular sponge for microRNA-7a-5p(miR-7-5p).This present study also proved that the knockdown of EGFR or overexpression of miR-7a-5p abolished the accelerative role of AFAP1-AS1 overexpression in cancer progression and gemcitabine tolerance.Conclusions:In general,the AFAP1-AS1/miR-7-5p/EGFR axis was tightly related to the progression and gemcitabine tolerance of cervical cancer,providing potential targets for the management of cervical cancer.
基金the Natural Science Foundation of Chongqing City, No. CSTC2006BB5037
文摘BACKGROUND：Motoneurons from the Onuf’s nucleus of the spinal cord, which innervate the striated muscle of the pelvic floor, play an important role in erection, ejaculation, and urine control. Serotonin （5-hydroxytryptamine, 5-HT） regulates motoneuron activity from the Onuf’s nucleus of the spinal cord. However, few studies exist that describe 5-HT receptor distribution in the Onuf’s nucleus. In addition, the nature of the effects of 5-HT receptor on the innervating striated muscle of the pelvic floor is controversial. OBJECTIVE： To investigate the distribution of serotonin 5-HT2A and 5-HT7 receptors in motoneurons of Onuf’s nucleus in the spinal cord of male rats, and to analyze the relationship of 5-HT2A and 5-HT7 receptor to central modulation of urogenital function. DESIGN, TIME AND SETTING： The neural morphology experiment was performed at the Ultramicro-structure Laboratory of Reproductive Medicine, Basic Medical College, Chongqing Medical University, China from April to December 2007. MATERIALS： Ten adult, Sprague Dawley rats （eight males and two females） were randomly divided into gender control group （n = 4, 50% male and 50% female） and a retrograde tracing group （n = 6, 100% male） Recombinant pseudorabies virus （PRV-152） was provided by Professor LW Enquist from Princeton University, USA. Rabbit anti-5-HT2A and 5-HT7 receptor antibodies were purchased from Diasorin, France. METHODS： In the gender control group, the spinal L5-6 segments were harvested, sliced, and then incubate antibodies specific against 5-HT2A or 5-HT7 receptors for immunohistochemical staining. In the retrograde tracing group, PRV-152 was separately injected into the right ischiocavernosus （ischiocavernosus subgroup, n = 3） and the right external urethral sphincter （external urethral sphincter subgroup, n = 3）. Four days after injection, L5-6 segments were harvested, sliced, and incubated with antibodies specific against 5-HT2A or 5-HT7 receptors for double-labeling immunofluorescence staining. MAIN OUTCOME MEASURES： Distribution analysis of 5-HT2A and 5-HT7 receptors in Onuf’s nucleus utilizing optical or laser confocal microscopy. RESULTS： 5-HT2A receptor immunoreactivity was revealed primarily in the medial region of the dorsolateral nucleus of Onuf’s nucleus. 5-HT7 receptor expression was observed in the lateral part of the dorso-lateral nucleus. 5-HT2A and 5-HT7 receptor expressions in the Onuf’s nucleus were significantly greater in male rats, compared to female rats. Double-labeling immunofluorescence demonstrated that 5-HT2A recepto were distributed primarily in the surrounding motoneurons innervating the ischiocavernosus, and 5-HT7 receptors were primarily expressed in motoneurons innervating the external urethral sphincter. CONCLUSION： Motoneurons innervating the ischiocavernosus and external urethral sphincter are located primarily in the medial and lateral region of the dorsolateral nucleus of L5-6 segments. The 5-HT2A receptor-innervating ischiocavernosus may be preferentially involved in the regulation of sexual reflex, and the 5-HT7 receptor-innervating external urethral sphincter may mainly join in regulating micturition reflex.
基金supported by National Natural Science Foundation of China(No.30271500)Science and Tech-nology Research Project Fund from the Department of Edu-cation of Hubei Province of China(No.B20115101)
文摘This study investigated the modulatory effect of synthetic cannabinoids WIN55,212-2 on 5-HT3 receptor-activated currents (I5-HT3) in cultured rat trigeminal ganglion (TG) neurons using whole-cell patch clamp technique. The results showed that: (1) The majority of examined neurons (78.70%) were sensitive to 5-HT (3–300 μmol/L). 5-HT induced inward currents in a concentration-dependent manner and the currents were blocked by ICS 205-930 (1 μmol/L), a selective antagonist of the 5-HT3 receptor; (2) Pre-application of WIN55,212-2 (0.01–1 μmol/L) significantly inhibited I5-HT3 reversibly in concentration-dependent and voltage-independent manners. The concentra-tion-response curve of 5-HT3 receptor was shifted downward by WIN55,212-2 without any change of the threshold value. The EC50 values of two curves were very close (17.5±4.5) mmol/L vs. (15.2±4.5) mmol/L and WIN55,212-2 decreased the maximal amplitude of I5-HT3 by (48.65±4.15)%; (3) Neither AM281, a selective CB1 receptor antagonist, nor AM630, a selective CB2 receptor antagonist reversed the inhibition of I5-HT3 by WIN55,212-2; (4) When WIN55,212-2 was given from 15 to 120 s before 5-HT application, inhibitory effect was gradually increased and the maximal inhibition took place at 90 s, and the inhibition remained at the same level after 90 s. We are led to concluded that-WIN55,212-2 inhibited I5-HT3 significantly and neither CB1 receptor antagonist nor CB2 receptor antagonist could reverse the inhibition of I5-HT3 by WIN55,212-2. Moreover, WIN55,212-2 is not an open channel blocker (OCB) of 5-HT3 receptor. WIN55,212-2 significantly inhibited 5-HT-activated currents in a non-competitive manner. The inhibition of I5-HT3 by WIN55,212-2 is probably new one of peripheral analgesic mechanisms of WIN55,212-2, but the mechanism by which WIN55,212-2 inhibits I5-HT3 warrants further investigation.
文摘AIM:To study the effects of 5-hydroxytryptamine(5-HT)receptor antagonists on normal colonic motor activity in conscious dogs.METHODS:Colonic motor activity was recorded using a strain gauge force transducer in 5 dogs before and after 5-HT2B,5-HT3 and 5-HT4 receptor antagonist administration.The force transducers were implanted on the serosal surfaces of the gastric antrum,terminal ileum,ileocecal sphincter and colon.Test materials or vehicle alone was administered as an intravenous bolus injection during a quiescent period of the whole colon in the interdigestive state.The effects of these receptor antagonists on normal gastrointestinal motor activity were analyzed.RESULTS:5-HT2B,5-HT3 and 5-HT4 receptor antagonists had no contractile effect on the fasting canine terminal ileum.The 5-HT3 and 5-HT4 receptor antagonists inhibited phaseⅢof the interdigestive motor complex of the antrum and significantly inhibited colonic motor activity.In the proximal colon,the inhibitory effect was dose dependent.Dose dependency,however,was not observed in the distal colon.The 5-HT2B receptor antagonist had no contractile effect on normal colonic motor activity.CONCLUSION:The 5-HT3 and 5-HT4 receptor antagonists inhibited normal colonic motor activity.The5-HT2B receptor antagonist had no contractile effect on normal colonic motor activity.
基金Supported by Grant G.0061.08 from the Fund for Scientific Research Flanders
文摘AIM: To investigate cellular 5-HT4(-h/+h) receptor distribution, particularly in the epithelial layer, by laser mi-crodissection and polymerase chain reaction (PCR) in porcine gastrointestinal (GI) tissues. METHODS: A stepwise approach was used to evaluate RNA quality and to study cell-specific 5-HT4 receptor mRNA expression in the porcine gastric fundus and colon descendens. After freezing, staining and laser microdissection and pressure catapulting (LMPC), RNA quality was evaluated by the Experion automated electrophoresis system. 5-HT4 receptor and glyceral-dehyde-3-phosphate dehydrogenase (GAPDH) expressions were examined by endpoint reverse transcription (RT)-PCR in mucosal and muscle-myenteric plexus (MMP) tissue fractions, in mucosal and MMP parts of hematoxylin and eosin (HE) stained tissue sections andin microdissected patches of the epithelial and circular smooth muscle cell layer in these sections. Pig gastric fundus tissue sections were also stained immunohisto-chemically (IHC) for enterochromaffin cells (EC cells; MAB352); these cells were isolated by LMPC and examined by endpoint RT-PCR. RESULTS: After HE staining, the epithelial and circular smooth muscle cell layer of pig colon descendens and the epithelial cell layer of gastric fundus were identified morphologically and isolated by LMPC. EC cells of pig gastric fundus were successfully stained by IHC and isolated by LMPC. Freezing, HE and IHC staining, and LMPC had no influence on RNA quality. 5-HT4 recep-tor and GAPDH mRNA expressions were detected in mucosa and MMP tissue fractions, and in mucosal and MMP parts of HE stained tissue sections of pig colon descendens and gastric fundus. In the mucosa tissue fractions of both GI regions, the expression of h-exon containing receptor [5-HT4(+h) receptor] mRNA was significantly higher (P<0.01) compared to 5-HT4(-h) re-ceptor expression, and a similar trend was obtained in the mucosal part of HE stained tissue sections. Large microdissected patches of the epithelial and circular smooth muscle cell layer of pig colon descendens and of the epithelial cell layer of pig gastric fundus, also showed 5-HT4 receptor and GAPDH mRNA expression. No 5-HT4 receptor mRNA expression was detected in gastric LMPC-isolated EC cells from IHC stained tissues, which cells were positive for GAPDH. CONCLUSION: Porcine GI mucosa predominantly expresses 5-HT4(+h) receptor splice variants, suggesting their contribution to the 5-HT4 receptor-mediated mu-cosal effects of 5-HT.
基金This study was supported by grants from the the National Natural Science Foundation of China(No.30170414)
文摘Objective：To investigate the role of 5-HT7 receptor in the pathogenesis of irritable bowel syndrome（IBS）. Methods：Rat model of D-IBS was established by intracolonic instillation of acetic acid and restraint stress; Rat model of C-IBS was established by stomach irrigated with 0-4℃ cool water daily for 14 d. The content and distribution of 5-HT7 receptor at the brain and bowel was examined by immunohistochemistry and the expression of 5-HT7 receptor mRNA was detected by fluorescence quantitative RT-PCR（Real-time PCR）. Results：Immunocytochemistry result showed the 5-HT7 rceptor positive staining at hippocampus and hypothalamus of both C-IBS and D-IBS group was stronger than that of control group（P 〈 0.01）. The 5-HT7R expression at ileum, proximate colon, distal colon of C-IBS group was significantly stronger than that of control group（P 〈 0.05）. Realtime-PCR analysis results showed the expression level of 5-HT7 receptor at hippocampus and hypothalamus of both C-IBS and D-IBS group was increased than that of control group（P〈 0.05）. At proximal and distal colon of C-IBS group, the 5-HT7 receptor mRNA expression was increased compared with control group（P〈 0.05）. Conclusion：The up-regulated expression of 5-HT7 receptor at brain and colon may play an important role in the pathogenesis of C-IBS.
文摘Hepatocytes were isolated from livers of adult male SpragueDawley rats and cultured in Williams'E Medium with 3 H thymidine. The effect of 5hydroxytryptamine (5HT) was investigated through adding various concentrations (10-810-3 mol/L) of 5HT to the hepatocyte cultures in the presence or absence of epidermal growth factor (EGF) and insulin. The involvement of 5HT2 receptor was examined by adding a 5HT2 receptor antagonist, ketanserin (10-6 mol/L), to some of the cultures containing 5HT. The increment of DNA synthesis was measured by 3 H thymidine incorporation. The results showed that 5HT2 (10-6 mol/L) significantly (P<005) increased the amount of DNA synthesis induced by EGF and insulin in the cultured adult rat hepaptocytes. The effect of 5HT in enhancing DNA synthesis began to appear at a concentration between 10-7 and 10-6 mol/L and reached maximum at concentrations of 10-4 mol/L. The enhancement of DNA synthesis by 5HT was significantly (P<005) antagonized by ketanserin, suggesting that this effect of 5HT was mediated by 5HT2 receptor subtype.
文摘Alzheimer’s disease (AD) is a progressive neurological disorder primarily affecting new memory formation as well as retrieval of previously acquired memories. According to World Health Organization, current global population suffering from cognitive impairment is estimated to 37 million. The number is projected to double in next one and half decade. Half of the population afflicted with dementia is represented by AD patients. Current therapies, which provide marginal symptomatic relief to AD patients, are effective only in half of the patient population. In depth understanding of the molecular mechanism of the disease is urgently required to develop more effective therapies. Therapies in clinical development may either offer symptomatic relief to patients or provide pure disease modifications, thus limiting benefit to patients. 5-HT4 receptor agonists offer an attractive option for the treatment of AD patients. Activation of 5- HT4 receptor under preclinical conditions is demonstrated to improve neurotransmission and enhance the release of acetylcholine resulting in the memory formation. In various cell based and animal models, partial 5-HT4 receptor agonists are demonstrated to promote the release of soluble amyloid precursor protein alpha and block the release of amyloid beta peptide offering suitable candidates as disease modification agents. Remarkably, 5-HT4 receptor agonists are also reported to induce neurogenesis in hippocampus as well as enteric system through the activation of cyclic AMP response element binding protein in rodents. Taken together, 5-HT4 agonists address all major facets of Alzheimer’s disease and may provide therapeutic potential for other neurological disorders.
