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Objective To investigate the effect of baicalin(BA)regulating cyclic adenosine phosphate(cAMP)/protein kinase A(PKA)/cAMP response elemen-binding protein(CREB)pathway on skin barrier function in eczema rats.Methods SD rats were randomly divided into the control group(NC group),the model group,the low-dose BA group(BA-L group,25 mg/kg),the medium-dose BA group(BA-M group,50 mg/kg),the high-dose BA group(BA-H group,100 mg/kg),the prednisone group(PNS group,25 mg/kg),the BA-H+cAMP inhibitor(SQ22536)group(100 mg/kg+2.13 mg/kg)and the BA-H+PKA inhibitor(H-89)group(100 mg/kg+5 mg/kg),12 animals in each group.Except for the NC group,eczema rat model was constructed in the other groups.Two days after successful modeling,drug administration was performed in groups.Changes of eczema area and severity index(EASI)score,transcutaneous water loss(TEWL)and cuticle water content(WCSC)were detected.Enzyme-linked immunosorbent assay(ELISA)was used to detect levels of immunoglobulin E(IgE),interferon-γ(IFN-γ)and interleukin-4(IL-4)in rat serum and the expression of cAMP protein in rat back lesions.HE staining was used to detect pathological changes of skin lesions on the back of rats.Western blot assay was used to detect aquaporin 3(AQP3),cathelicidin related antimicrobial peptide(CRAMP),p-PKA,p-CREB protein expression in rat back lesions.Results Compared with the NC group,rats had serious pathological lesions on the back of the tested area,increased EASI score,TEWL,IgE and IL-4 levels,and decreased WCSC,IFN-γ,AQP3,CRAMP,cAMP,p-PKA and p-CREB protein levels in the model group(P<0.05).Compared with the model group,pathological lesion of the tested area in the back of rats was relieved,and EASI score,TEWL,IgE and IL-4 levels were decreased,WCSC,IFN-γ levels,AQP3,CRAMP,cAMP,p-PKA and p-CREB protein were increased in the BA-L group,the BA-M group,the BA-H group and the PNS group(P＜0.05).Changes of above indexes in the BA-L group,the BA-M group,the BA-H group were dose-dependent.SQ22536 or H-89 attenuated the improvement effect of high dose BA on skin barrier function in eczema rats.Conclusion BA may improve skin barrier function in eczema rats by activating cAMP/PKA/CREB signaling pathway.
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Objective:To evaluate the effect of esketamine on learning and memory function after chronic stress and the signaling pathway of N-methyl-D-aspartate receptor (NMDAR)-calmodulin-dependent protein kinase type 2 (CaMKⅡ)-cAMP-responsive element-binding protein (CREB) in the hippocampus of developing rats.Methods:Sixty clean-grade healthy Sprague-Dawley rats of either sex, aged 7 days, weighing 10-15 g, were divided into 3 groups ( n=20 each) using a random number table method: control+ normal saline group (CN group), chronic stress+ normal saline group (NS group), and chronic stress+ esketamine group (ES group). A chronic stress model was established using a chronic unpredictable stress method. After the end of stress stimulation, esketamine 10 mg/kg was intraperitoneally injected once a day for 7 consecutive days in ES group, and the equal volume of normal saline was given instead in NS group. Y maze test and Morris water maze test were used to assess the learning and memory function after intraperitoneal administration. Venous blood samples were obtained to measure the serum cortisol and reactive oxygen species (ROS) concentrations by enzyme-linked immunosorbent assay. The animals were then sacrificed under anesthesia, the brain was removed and the hippocampal tissue was isolated for examination of the pathological changes in the hippocampal CA1 region and for determination of the ratios of phosphorylated NMDAR (p-NMDAR)/NMDAR, phosphorylated CaMKII (p-CaMKⅡ)/CaMKⅡ, and phosphorylated CREB (p-CREB)/CREB (by Western blot). Results:Compared with CN group, the time spent in the novel arm was significantly shortened, the number of entries into the novel arm was reduced, the escape latency was prolonged, the number of crossing the original platform was reduced, the serum cortisol and ROS concentrations were increased, the p-NMDAR/NMDAR ratio, p-CaMKⅡ/CaMKⅡ ratio and p-CREB/CREB ratio were decreased ( P<0.05), and the pathological changes of neurons were marked in NS group. Compared with NS group, the time spent in the novel arm was significantly prolonged, the number of entries into the novel arm was increased, the escape latency was shortened, the number of crossing the original platform was increased, the serum cortisol and ROS concentrations were decreased, the p-NMDAR/NMDAR ratio, p-CaMKⅡ/CaMKⅡ ratio and p-CREB/CREB ratio were increased ( P<0.05), and the pathological changes of neurons were significantly attenuated in ES group. Conclusions:Esketamine can improve the learning and memory function after chronic stress in developing rats, and the mechanism may be related to reduction of oxidative stress and enhancement of the activity of hippocampal NMDAR-CaMKII-CREB signaling pathway.
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Objective:To evaluate the effect of surgery under propofol anesthesia during mid-pregnancy on the cognitive function and hippocampal histone deacetylase 2 (HDAC2)-cAMP response element-binding protein (CREB)-N-methyl-D-aspartate (NMDA) receptor 2B subunit (NR2B)-containing NMDA receptor (NR2B) signaling pathway in the offspring rats.Methods:Thirty healthy Sprague-Dawley rats at 14 days of gestation were divided into 3 groups ( n=10 each) using a random number table method: propofol anesthesia group (P group), surgery under propofol anesthesia group (S group) and control group (C group). In S group, propofol 20 mg/kg was injected via the caudal vein, and then propofol was continuously infused at a rate of 20 mg·kg -1·h -1 to maintain anesthesia for 4 h, and exploratory laparotomy was performed. Group P received no exploratory laparotomy and the other treatments were similar to those previously described in group S. The equal volume of normal saline was given instead in group C. The learning and memory of the offspring rats was assessed using Morris water maze test on postnatal day 30. The expression of HDAC2, phosphorylated CREB (p-CREB), NR2B, brain-derived neurotriphic factor (BDNF) and phosphorylated tyrosine kinase B (p-TrkB) in offspring′s hippocampi was evaluated by Western blot. Apoptosis in hippocampal neurons was detected by TUNEL staining. Results:Compared with group C, the escape latency was significantly prolonged, the frequency of crossing the original platform was decreased, the time spent in the second quadrant was shortened, the expression of HDAC2 was up-regulated, the expression of p-CREB, NR2B, BDNF and p-TrkB was down-regulated, and the apoptosis rate of the hippocampal neurons was increased in P and S groups ( P<0.05). Compared with P group, the escape latency was significantly prolonged, the frequency of crossing the original platform was decreased, the time spent in the second quadrant was shortened, the expression of HDAC2 was up-regulated, the expression of p-CREB, NR2B, BDNF and p-TrkB was down-regulated, and the apoptosis rate of the hippocampal neurons was increased in S group ( P<0.05). Conclusions:Surgery under propofol anesthesia during mid-pregnancy can decrease the cognitive function of offspring rats, and the mechanism is related to the regulation of HDAC2-CREB-NR2B signaling pathway and the promotion of apoptosis in hippocampal neurons.
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Objective:To evaluate the effect of edaravone on the extracellular signal-regulated kinase (ERK)-cAMP responsive element binding protein (CREB) signaling pathway in the hippocampus of aged rats with postoperative cognitive dysfunction (POCD).Methods:Sixty SPF healthy male Sprague-Dawley rats, aged 20 months, weighing 650-700 g, were divided into 4 groups ( n=15 each) using a random number table method: control group (group C), POCD group (group P), edaravone group (group E) and ERK inhibitor group (group I). The rats received laparotomy under 3% sevoflurane anesthesia to prepare POCD model in P, E and I groups. Edaravone 3 mg/kg was intraperitoneally injected at 30 min before operation in E and I groups, ERK inhibitor PD98059 0.3 mg/kg was injected via the tail vein in group I. The open field test was performed at 3 days after operation to evaluate the spontaneous activity of rats, then Morris water maze test was performed to evaluate the cognitive function of rats on 3-7 days after operation. The rats were sacrificed after the end of Morris water maze test, and hippocampal tissues were obtained for determination of the expression of phosphorylated ERK (p-ERK), phosphorylated CREB (p-CREB), synaptophysin and postsynaptic density protein 95 (PSD-95) (by Western blot) and dendrite length and density of dendrites in hippocampal CA1 area (using Golgi staining). Results:Compared with group C, the escape latency was significantly prolonged after operation, the number of crossing the original platform was reduced, the expression of p-ERK, p-CREB, synaptophysin and PSD-95 was down-regulated, and the dendritic length and density of hippocampal neurons were reduced in group P ( P<0.05). Compared with group P, the escape latency was significantly shortened, the number of crossing the original platform was increased, the expression of p-ERK, p-CREB, synaptophysin and PSD-95 was up-regulated, and the dendritic length and density of hippocampal neurons were increased in group E ( P<0.05). Compared with group E, the escape latency was significantly prolonged, the number of crossing the original platform was reduced, the expression of p-ERK, p-CREB, synaptophysin and PSD-95 was down-regulated, the dendritic length of hippocampal neurons was shortened, and the density of hippocampal neurons was decreased in group I( P<0.05). Conclusions:The mechanism by which edaravone improves POCD may be related to activating ERK/CREB signaling pathway and changing synaptic plasticity in hippocampal CA1 region in aged rats.
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Objective To stud)' the nerve repair effect of olanzapine on schizophrenia model rats through its effect on cyclic AMP response element binding protein (CREB)/brain-derived neurotrophic factor (BDNF)/receptor tyrosine kinase receptors B (TrkB) pathway. Methods Total 60 rats were divided into control group, model group, olanzapine low, middle and high dose group. The rats in the model group, olanzapine low, middle and high dose groups were injected intraperitoneally with MK-801[0. 2 mg/(kg-d) ], while the control injected with the same amount of normal saline. The low, middle and high dose olanzapine groups were perfused with olanzapine solution of 0. 5 mg/(kg-d),1. 0 mg/(kg-d) and 1. 5 mg/(kg-d) respectively. The behavior of rats was scored according to ataxia and stereotyped behavior standards, cognitive function and learning ability were evaluated by Moms water maze test, serum tumor necrosis factor-a (TNF-a) and interleukin-6 (IL-6) levels were detected by ELISA method, hippocampal histopathology was observed under microscope, and apoptosis and expression of CREB/BDNF/TrkB pathway related proteins in hippocampus were detected. Results Compared with the control group, the ataxia, the score of stereotyped behavior, the expression of TNF-a, IL-6 and the rate of apoptosis in the model group increased significantly (P < 0 . 01). Compared with the control group, the number of crossing the platform, the time of staying in the target quadrant and the relative expression of CREB, p-CREB, p-TrkB, TrkB and BDNF protein in the model group decreased significantly (P<0. 01), and those in the low and middle dose olanzapine groups decreased significantly (P < 0 . 05). Compared with the model group, the times of crossing the platform and the stay time in the target quadrant increased significantly in the low and middle dose olanzapine groups (P< 0. 05). In the model group and the low dose olanzapine group, the hippocampal cells were swollen obviously, the nucleus was broken and divided, pyknosis, and the tissue aiTangement was disorderly, while the phenomenon of fragmentation and nuclear pyknosis was rarely seen in the middle and high dose olanzapine groups. Conclusion The nerve repair mechanism of olanzapine on schizophrenic model rats is related to improving cognitive impainnent, protecting hippocampal neurons and activating the expression of CREB/BDNF/TrkB signal pathway in rats.
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Objective:To evaluate the role of protein kinase A (PKA)-cyclic adenosine monophosphate response element binding protein (CREB) signaling pathway in sevoflurane-induced reduction of cardiopulmonary bypass (CPB)-induced cognitive impairment in rats.Methods:Forty healthy male Sprague-Dawley rats, aged 4 months, weighing 300-350 g, were divided into 4 groups ( n=10 each) using a random number table method: control group (group C), group CPB, CPB+ sevoflurane group (group CS) and CPB+ sevoflurane+ PKA inhibitor H89 group (group CSH). After H89 5 μl was injected into the lateral ventricle in group CSH, the rats in group CS and group CSH were exposed to 2.4% sevoflurane for 1 h, and then the CPB model of beating heart without blood priming for 60 min was developed in CPB, CS and CSH groups.The autonomic movement ability was evaluated using the open field test at 2nd day after CPB.Morris water maze test was used to assess the cognitive function at 3rd day after CPB.The rats were sacrificed after the Morris water maze test, the brain was removed and the hippocampal tissues were isolated for determination of the apoptosis rate of hippocampal neurons (by flow cytometry) and expression of PKA, phosphorylated CREB (p-CREB) and brain-derived neurotrophic factor (BDNF) (by Western blot). Results:There was no significant difference in movement speed, distance and time of staying at the central region among the four groups ( P>0.05). Compared with group C, the escape latency was significantly prolonged, the number of crossing the original platform was reduced, the time of staying at the original platform quadrant was shortened, the apoptosis rate of hippocampal neurons was increased, and the expression of PKA, p-CREB and BDNF was down-regulated in the other three groups ( P<0.05). Compared with group CPB, the escape latency was significantly shortened, the number of crossing the original platform was increased, the time of staying at the original platform quadrant was prolonged, the apoptosis rate of hippocampal neurons was decreased, and the expression of PKA, p-CREB and BDNF was up-regulated in group CS ( P<0.05), and no significant change was found in the indexes mentioned above in group CSH ( P>0.05). Compared with group CS, the escape latency was significantly prolonged, the number of crossing the original platform was reduced, and the time of staying at the original platform quadrant was shortened, the apoptosis rate of hippocampal neurons was increased, and the expression of PKA, p-CREB and BDNF was down-regulated in group CSH ( P<0.05). Conclusions:Sevoflurane can reduce the apoptosis in hippocampal neurons by activating PKA-CREB signaling pathway, and thus reducing the cognitive impairment induced by CPB in rats.
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Abstract Alzheimer's disease is a neurodegenerative condition that causes changes in memory and cognition, in addition to behavioral disorders, and most commonly affects the elderly. Several studies in the literature have presented therapeutic measures in an attempt to interfere with the pathogenic mechanisms of the disease and to mitigate its clinical manifestations. Some factors, such as excitotoxicity, cholinergic dysfunctions, oxidative stress, tau protein hyperphosphorylation, changes in amyloid-beta peptide metabolism, herpes viruses, apolipoprotein E, glycogen synthase kinase 3, insulin resistance, and the endocannabinoid system seem to be related to pathophysiology of Alzheimer's disease. Given this, a literature review was carried out to address the molecular mechanisms associated with the pathophysiological hypotheses previously mentioned, aiming to better understanding their underlying causes and contributing to possible pharmacological strategies about treatment of the disease.
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Objective:To investigate the effects of upregulation of cAMP response element binding protein (CREB) on proliferation, invasion and natural killer (NK) cell killing activity of esophageal adenocarcinoma.Methods:23 patients with esophageal cancer treated in Shaanxi Provincial People′s Hospital from March 2017 to December 2019 were selected. The protein expression of CREB in esophageal adenocarcinoma and adjacent normal tissues was detected by immunohistochemistry; Esophageal adenocarcinoma cell line TE-10 was cultured in vitro. TE-10 cells transfected with si-NC were set as the control group and TE-10 cells transfected with si-CREB were set as the si-CREB group. Western blot was used to detect the protein level of CREB, MHC class Ⅰ chain-related A (MICA) and MHC class Ⅰ chain-related B (MICB); Flow cytometry was employed to detect the expression of MICA and MICB; clone formation experiment and Transwell were used to detect the proliferative and invasive ability of TE-10 cells; lactate dehydrogenase (LDH) releasing assay was used to detect cytotoxicity of NK cells against TE-10 cells. Results:The expression of CREB in esophageal adenocarcinoma tissue was higher than that in normal tissues adjacent to cancer; the protein level of CREB in esophageal cancer cell TE-10 was higher than that of human normal esophageal epithelial cells HEEC ( P<0.05). The proliferative and invasive ability of TE-10 cells in the si-CREB group was significant lower than that in the control group ( P<0.05), while the expression of MICA and MICB, the killing rate of NK cells on TE-10 cells was significant higher than that in the control group ( P<0.05). Conclusions:CREB was highly expressed in esophageal adenocarcinoma tissues and cells. Silencing CREB could inhibit the proliferation and invasion of esophageal adenocarcinoma cells, and enhance the killing sensitivity of NK cells to esophageal adenocarcinoma cells by up-regulating the expression of MICA and MICB.
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Objective:To evaluate the role of extracellular signal-regulated kinase 1/2 (ERK1/2)/cyclic adenosine monophosphate response element-binding protein (CREB)/brain-derived neurotrophic factor (BDNF) signaling pathway in dexmedetomidine-induced inhibition of propofol-caused apoptosis in isolated hippocampal neurons of fetal rats.Methods:Pregnant Sprague-Dawley rats at 16 days of gestation were sacrificed, and the fetal rats were taken out, and hippocampal neurons of fetal rats were obtained and primarily cultured in vitro for 7 days.The neurons were divided into 9 groups ( n=12 each) using a random number table method: control group (group C), fat emulsion group (group I), dimethyl sulfoxide (DMSO) group, dexmedetomidine group (group D), propofol group (group P), propofol plus dexmedetomidine group (group PD), PD98059 plus propofol plus dexmedetomidine group (group PDP), MH89 plus propofol plus dexmedetomidine group (group HDP), and KG501 plus propofol plus dexmedetomidine group (group KDP). Group C received no treatment.In group I, 20% fat emulsion was added, and the neurons were incubated for 30 min, and 0.25% DMSO was added in group DMSO, and the neurons were incubated for 30 min.Dexmedetomidine at a final concentration of 10 μmol/L was added, and the neurons were incubated for 30 min in group D. Propofol at a final concentration of 100 μmol/L was added, and the neurons were incubated for 3 h in group P. In group PD, dexmedetomidine at a final concentration of 10 μmol/L was added, the neurons were incubated for 30 min, propofol at a final concentration of 100 μmol/L was added, and the neurons were incubated for 3 h. In PDP, HDP and KDP groups, 25 μmol PD98059 (p-ERK1/2 inhibitor), 10 μmol H89 (p-CREB inhibitor) and 25 μmol KG501 (CREB inhibitor) were added, respectively, the neurons were incubated for 30 min, dexmedetomidine at a final concentration of 10 μmol/L was added, the neurons were incubated for 30 min, and propofol at a final concentration of 100 μmol/L was added, and the neurons were incubated for 3 h. The cell ultrastructure was observed with the transmission electron microscope, the apoptosis in neurons was detected by flow cytometry, the expression of ERK1/2, CREB and BDNF mRNA was detected by quantitative real-time polymerase chain reaction, and the expression of p-ERK1/2, CREB, p-CREB, BDNF and cleaved caspase-3 was detected by Western blot. Results:Compared with group C, the apoptosis rate was significantly increased, the expression of p-ERK1/2 and p-CREB was down-regulated, and the expression of cleaved caspase-3 was up-regulated in P, PD, PDP, HDP and KDP groups, and the expression of BDNF was significantly down-regulated in P, PDP, HDP and KDP groups ( P<0.05). Compared with group P, the apoptosis rate was significantly decreased, the expression of p-ERK1/2, p-CREB and BDNF was up-regulated, and the expression of cleaved caspase-3 was down-regulated in group PD ( P<0.05). Compared with group PD, the apoptosis rate was significantly increased, the expression of p-ERK1/2, p-CREB and BDNF was down-regulated, and the expression of cleaved caspase-3 was up-regulated in PDP, HDP and KDP groups ( P<0.05). Conclusion:The ERK1/2/CREB/BDNF signaling pathway is involved in dexmedetomidine-induced inhibition of propofol-caused apoptosis in isolated hippocampal neurons of fetal rats.
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Objective:To evaluate the role of p38 mitogen-activated protein kinase (MAPK)/cyclic adenosine monophosphate response element-binding protein (CREB) signaling pathway in tetramethylpyrazine-induced reduction of hippocampal inflammatory responses in mice with sepsis-associated encephalopathy (SAE).Methods:Sixty healthy male C57BL6 mice, weighing 24-27 g, were divided into 4 groups ( n=15 each) using a random number table method: sham operation group (group Sham), sepsis group (group Sep), tetramethylpyrazine group (group TMP) and p38 MAPK inhibitor SB203580 group (group SB). The model of SAE was established by cecal ligation and puncture in anesthetized mice.Tetramethylpyrazine 10 mg/kg was injected intraperitoneally once a day at 3 days before the establishment of the model in TMP group, and SB203580 2.0 mg/kg was intraperitoneally injected at 30 min after the establishment of the model in SB group.The equal volume of normal saline was given intraperitoneally in Sham and Sep groups.At 1 day after operation, cognitive function was assessed by Morris water maze, and the escape latency and ratio of time spent in the target quadrant were recorded.The animals were sacrificed after the test, and hippocampal tissues were taken for determination of the contents of interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α) and IL-6 (by enzyme-linked immunosorbent assay) and for detection of the expression of phosphorylation of p38 MAPK, GSK3 and CREB and expression of brain-derived neurotrophic factor (BDNF) (by Western blot). Results:Compared with group Sham, the escape latency was significantly prolonged, the ratios of time spent in the target quadrant were decreased, the contents of IL-1β, TNF-α and IL-6 were increased, the phosphorylation of hippocampus p38 MAPK was increased, the phosphorylation of GSK3 and CREB were decreased, and the expression of BDNF was down-regulated in Sep, TMP and SB groups ( P<0.05). Compared with group Sep, the escape latency was significantly shortened, the ratios of time spent in the target quadrant were increased, the contents of IL-1β, TNF-α and IL-6 were decreased, the phosphorylation of hippocampus p38 MAPK was decreased, the phosphorylation of GSK3 and CREB were increased, and the expression of BDNF was up-regulated in TMP and SB groups ( P<0.05). Compared with group TMP, no significant change was found in the parameters mentioned above in group SB ( P>0.05). Conclusion:p38 MAPK/CREB signaling pathway is involved in the process of tetramethylpyrazine-induced reduction of hippocampal inflammatory responses in mice with SAE.
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Objective:To evaluate the effect of pre-infusion of young rat plasma on cognitive dysfunction induced by sevoflurane in aged rats and the role of extracellular regulated protein kinase (ERK)-cyclic adenosine monophosphate effector binding protein (CREB) signaling pathway.Methods:One hundred and twenty SPF healthy male Wistar rats, aged 18 months, weighing 550-650 g, were divided into 4 groups ( n=30 each) using a random number table method: control group (group C), sevoflurane anesthesia group (group S), young rat plasma group (group P) and ERK inhibitor SL327 group (group SL). The teated plasma 100 μl from 3-month-old young rats was injected via the tail vein in group P and group SL, while the equal volume of normal saline was given via the tail vein in group C and group S, twice a week, for 4 weeks.In S, P and SL groups, 3% sevoflurane was inhaled for 3 h at the end of injection, and ERK inhibitor SL327 50 mg/kg was injected via the tail vein before anesthesia in group SL.The cognitive function was evaluated by Morris water maze test at 1 day before anesthesia and at 3 and 7 days after anesthesia.The rats were sacrificed, and their hippocampi were isolated for determination of the expression of phosphorylated ERK (p-ERK), p-CREB, synapsin, synapsin Ⅰ and synaptophysin and for examination of the ultrastructure of neurons (by transmission electron microscopy). The number of synapses was recorded. Results:Compared with group C, the escape latency was significantly prolonged, the number of crossing the original platform was reduced, the expression of p-ERK, p-CREB, synapsin, synapsin Ⅰ and synaptophysin was down-regulated, and the number of synapses was decreased at each time point after anesthesia in the other 3 groups ( P<0.05). Compared with group S, the escape latency was significantly shortened, the number of crossing the original platform was increased, the expression of p-ERK, p-CREB, synapsin, synapsin Ⅰ and synaptophysin was up-regulated, and the number of synapses was increased at each time point after anesthesia in P and SL groups ( P<0.05). Compared with group P, the escape latency was significantly prolonged, the number of crossing the original platform was reduced, the expression of p-ERK, p-CREB, synapsin, synapsin Ⅰ and synaptophysin was down-regulated, and the number of synapses was decreased in group SL ( P<0.05). Conclusion:Pre-infusion of young rat plasma can reduce cognitive dysfunction induced by sevoflurane in aged rats, and the mechanism is related to activation of ERK-CREB signaling pathway and improvement of synaptic plasticity.
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BACKGROUND: The pain-relief properties of tricyclic antidepressants can be attributed to several actions. Recent observations suggest that adenosine is involved in the antinociceptive effect of amitriptyline. The A3 adenosine receptor (A3AR) is the only adenosine subtype overexpressed in inflammatory and cancer cells. This study was performed to investigate the role of A3AR in the anti-nociceptive effect of amitriptyline. METHODS: Spinal nerve-ligated neuropathic pain was induced by ligating the L5 and L6 spinal nerves of male Sprague-Dawley rats. The neuropathic rats were randomly assigned to one of the following three groups (8 per group): a neuropathic pain with normal saline group, a neuropathic pain with amitriptyline group, and a neuropathic pain with amitriptyline and 3-ethyl-5-benzyl- 2-methyl-4-phenylethynyl-6-phenyl-1,4-(±)-dihydropyridine-3,5-dicarboxylate (MRS) group. Amitriptyline or saline was administered intraperitoneally and 3-ethyl-5-benzyl-2-methyl-4-phenylethynyl-6-phenyl-1,4-(±)-dihydropyridine-3,5-dicarboxylate (MRS-1191), an A3AR antagonist, was injected subcutaneously immediately before amitriptyline administration. The level of extracellular signal-regulated kinase P44/42 (ERK1/2), cyclic AMP response element-binding protein (CREB), and proinflammatory cytokines were assessed using immunoblotting or reverse-transciption polymerase chain reaction. RESULTS: Amitriptyline increased the mechanical withdrawal threshold of the neuropathic rats. The level of phospho-ERK1/2 and phospho-CREB proteins, and proinflammatory cytokines produced by spinal nerve ligation were significantly reduced by amitriptyline administration. However, the use of MRS-1191 before amitriptyline administration not only reduced the threshold of mechanical allodynia, but also increased the signaling protein and proinflammatory cytokine levels, which were reduced by amitriptyline. CONCLUSIONS: The results of this study suggest that the anti-nociceptive effect of amitriptyline involves the suppression of ERK1/2 and CREB signaling proteins, and A3AR activation also affects the alleviation of the inflammatory response.
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Animals , Humans , Male , Rats , Adenosine , Amitriptyline , Antidepressive Agents, Tricyclic , Cyclic AMP Response Element-Binding Protein , Cytokines , Hyperalgesia , Immunoblotting , Ligation , Neuralgia , Phosphotransferases , Polymerase Chain Reaction , Rats, Sprague-Dawley , Receptors, Purinergic P1 , Spinal NervesABSTRACT
Objective To evaluate the effects of melatonin on the excitability of pyramidal neurons in the prefrontal cortex and the role of melatonin receptor 1 (MT1 R)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling pathway.Methods Brains were obtained from male SpragueDawley rats between 14 and 21 days after birth.The brain slices of 350-μm thick were prepared and placed in artificial cerebrospinal fluid.The brain slices were divided into 5 groups (n =6 each) using a random number table method:control group (C group),melatonin group (M group),MT1/2R antagonist luzindole plus melatonin group (L+M group),MT2R antagonist 4P-PDOT plus melatonin group (P+M group) and PKA inhibitor Rp-cAMPS plus melatonin group (R+M group).Cells were perfused for 2 min with artificial cerebrospinal fluid in group C.Cells were perfused for 2 min with 1 μmol/L melatonin in group M.Cells were perfused for 2 min with the mixture of 1 μmol/L MT1/2R antagonist luzindole and 1 μmol/L melatonin in group L+M.Cells were perfused for 2 min with the mixture of 1 μmol/L MT2R antagonist 4P-PDOT and 1 μmol/L melatonin in group P+M.In group R+M,1 mmol/L PKA inhibitor Rp-cAMPS was continuously added to the pipette solution,and cells were perfused for 2 min with 1 μmol/L melatonin.The whole-cell patch-clamp technique was used to record the membrane potential and clamp current of pyramidal neurons in the prefrontal cortex.Results Compared with group C,the clamp current was significantly increased,and the membrane potential was decreased in group M (P＜0.05).Compared with group M,the clamp current was significantly decreased,and the membrane potential was increased in L + M and R + M groups (P＜0.05),and no significant change was found in the clamp current or membrane potential in group P+M (P＞0.05).Conclusion Melatonin inhibits the excitability of pyramidal neutrons in the prefrontal cortex,and the mechanism is related to activating MT1 R-cAMP-PKA signaling pathway.
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To observe therapeutic effect of L‐carnitine combined cyclic adenosine monophosphate and its influence on serum levels of IFN‐γ and IL‐4 in patients with viral myocarditis .Methods : A total of 132 VMC pa‐tients treated in our hospital from 2017 to 2018 were randomly and equally divided into L‐carnitine group and com‐bined treatment group (received cAMP based on L‐carnitine group ) , both groups were treated for two weeks .Pe‐ripheral serum levels of IFN‐γ , IL‐4 , cardiac troponin T (cTnT) and creatine kinase isoenzyme MB (CK‐MB) be‐fore and two weeks after treatment , therapeutic effect and incidence of adverse drug reactions were observed and compared between two groups .Results : Compared with before treatment , there was significant rise in serum IL‐4 level , and significant reductions in serum levels of IFN‐γ , cTnT and CK‐MB in two groups after two‐week treat‐ment , P＝0. 001 all ;compared with L‐carnitine group , there was significant rise in serum IL‐4 level [ (47. 43 ± 9.17) ng／ml vs.(55. 38 ± 10.23 ) ng／ml] , and significant reductions in serum levels of IFN‐γ [ (65.22 ± 11.82 ) ng／ml vs .(52.18 ± 10.06) ng／ml] , cTnT [ (0. 37 ± 0.09) ng／ml vs.(0.18 ± 0.03) ng／ml] and CK‐MB [ (28.56 ± 5. 34) U／L vs.(16. 22 ± 3. 47) U／L] in combined treatment group , P＝0.001 all.Total effective rate of com‐bined treatment group was significantly higher than that of L‐carnitine group (92.4% vs.80.3%) , P＝ 0.042. There was no significant difference in incidence rate of adverse drug reactions between two groups , P＝0. 784. Con‐clusion : L‐carnitine combined cAMP can significantly reduce peripheral serum IFN‐γ level and increase IL‐4 level , regulate Th1／Th2 imbalance with significant therapeutic effect in VMC patients .And its safety is good .
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To compare therapeutic effect of dibutyryl cyclic adenosine monophosphate calcium (DCAMC) on chronic heart failure (CHF) between different administration route .Methods :The 98 CHF patients were ran‐ domly and equally divided into intravenous drip (i .v.gtt) group and intramuscular injection group (i.m .) group , both groups received DCAMC via corresponding administration route based on routine anti heart failure treatment for 10d.Plasma level of N terminal pro brain natriuretic peptide (NT‐proBNP) ,left ventricular end diastolic dimen‐sion (LVEDd) ,LVEF before and after treatment ,and incidence of adverse reactions were observed and compared between two groups .Results :Compared with before treatment , there were significant reductions in plasma NT‐proBNP level [i.v.gtt group :(6846.23 ± 3856. 01)pg／ml vs.(2285.69 ± 2023.79)pg／ml ,i .m .group :(6151. 50 ± 5160.09) pg／ml vs.(2568.37 ± 2488.51)pg／ml] and LVEDd [i.v.gtt group :(4.78 ± 0.44 )cm vs.(4. 69 ± 0.43) cm ,i.m .group :(4.97 ± 0.64)cm vs .(4. 88 ± 0.62) cm] ,and significant rise in LVEF [i.v.gtt group :(59.49 ± 4.64)% vs.(60. 67 ± 4. 52)%,i.m.group :(57.67 ± 7.19)% vs.(58.94 ± 7.05)%] in two groups after treatment , P＝0.001 all.There were no significant difference in above indexes between two groups before and after treatment , P＞0. 05 all.There was no significant difference in incidence rate of adverse reactions between two groups , P＝1.000. Conclusion :DCAMC can improve cardiac function in CHF patients .Therapeutic effect of local intramuscular injection is equal with that of intravenous drip .
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Objective To evaluate the role of cyclic adenosine monophosphate-protein kinase A-cAMP response element-binding protein (cAMP-PKA-CREB) signaling pathway in hypoxic preconditioninginduced reduction of propofol-induced central neurotoxicity in the developing rats.Methods A total of 70 SPF male Sprague-Dawley rats,aged 7 days,weighing 10-15 g,were divided into 7 groups (n=10 each) using a random number table method:normal saline group (N group),propofol group (P group),hypoxic preconditioning plus propofol group (HP group),hypoxic preconditioning plus propofol plus PKA inhibitor H89 group (HPH group),propofol plus PKA agonist SP-CAMP group (PS group),normal saline injected via the lateral cerebral ventricle group (NI group),and 5％ dimethyl sulfoxide (DMSO) injected via the lateral cerebral ventricle group (DI group).In P group,propofol 50 mg/kg was intraperitoneally injected,and an increment of propofol 50 mg/kg was given after recovery of righting reflex.The equal volume of normal saline was given instead in N group.In HP group,hypoxic preconditioning (rats were subjected to 5 cycles of 10-min hypoxia of 8％ O2 and 1O-min normoxia of 21％ O2) was performed,and propofol was intraperitoneally injected at 2 h after the end of hypoxic preconditioning and the method was similar to those previously described in P group.In HPH group,H89 5 μmol/5 μl was injected via the lateral cerebral ventricle,and 30 min later the other treatment was similar to those previously described in HP group.In PS group,SP-CAMP 20 nmol/5 μl was injected via the lateral cerebral ventricle,and 30 min later propofol was injected using the method previously described in P group.In NI and DI groups,5 μl normal saline and 5％ DMSO were injected via the lateral cerebral ventricle,respectively.Rats were immediately sacrificed after the righting reflex was recovered,brains were removed and hippocampi were isolated and cut into sections which were stained with haematoxylin and eosin for determination of PKAc and p-CREB positive cells (by i mmuno-histochemistry) and expression of cleaved caspase-3,Bcl-2,Bax,PKAc and posphorylated (p-CREB) protein (by Western blot).Results Compared with N group,the expression of cleaved caspase-3 and Bax was significantly up-regulated,the expression of Bcl-2,PKAc and p-CREB was downregulated,and the percentage of PKAc and p-CREB positive cells was decreased (P＜0.05),hippocampal cells had irregular arrangement,and cells was atrophied in P group.Compared with P group,the expression of cleaved caspase-3 was significantly down-regulated,the expression of Bcl-2,PKAc and p-CREB was up-regulated,and the percentage of PKAc and p-CREB positive cells was increased in HP and PS groups,and the expression of Bax was down-regulated (P＜0.05),the hippocampal cells were arranged neatly,the cytoplasm was abundant,and the nuclei were visible in HP group.Compared with HP group,the expression of cleaved caspase-3 was significantly up-regulated,the expression of Bcl-2,PKAc and p-CREB protein was down-regulated and the percentage of PKAc and p-CREB positive cells was decreased (P＜0.05),the cells had irregular arrangement and shrinked,and nuclear condensation was found in cells in HPH group.Conclusion The mechanism by which hypoxic preconditioning reduces propofol-induced central neurotoxicity may be related to activating cAMP-PKA-CREB signaling pathway in the developing rats.
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BACKGROUND/OBJECTIVES: Fermented Laminaria japonica (FL), a type sea tangle used as a functional food ingredient, has been reported to possess cognitive improving properties that may aid in the treatment of common neurodegenerative disorders, such as dementia. MATERIALS/METHODS: We examined the effects of FL on scopolamine (Sco)- and ethanol (EtOH)-induced hippocampus-dependent memory impairment, using the Passive avoidance (PA) and Morris water maze (MWM) tests. To examine the underlying mechanisms associated with neuroprotective effects, we analyzed acetylcholine (ACh) and acetylcholinesterase (AChE) activity, brain tissue expression of muscarinic acetylcholine receptor (mAChR), cAMP response element binding protein (CREB) and extracellular signal-regulated kinases 1/2 (ERK1/2), and immunohistochemical analysis, in the hippocampus of mice, compared to current drug therapy intervention. Biochemical blood analysis was carried out to determine the effects of FL on alanine transaminase (ALT), aspartate transaminase (AST), and triglyceride (TG) and total cholesterol (TC) levels. 7 groups (n = 10) consisted of a control (CON), 3 Sco-induced dementia and 3 EtOH-induced dementia groups, with both dementia group types containing an untreated group (Sco and EtOH); a positive control, orally administered donepezil (Dpz) (4mg/kg) (Sco + Dpz and EtOH + Dpz); and an FL (50 mg/kg) treatment group (Sco + FL50 and EtOH + FL50), orally administered over the 4-week experimental period. RESULTS: FL50 significantly reduced EtOH-induced increase in AST and ALT levels. FL50 treatment reduced EtOH-impaired step-through latency time in the PA test, and Sco- and EtOH-induced dementia escape latency times in the MWM test. Moreover, anticholinergic effects of Sco and EtOH on the brain were reversed by FL50, through the attenuation of AChE activity and elevation of ACh concentration. FL50 elevated ERK1/2 protein expression and increased p-CREB (ser133) in hippocampus brain tissue, according to Western blot and immunohistochemistry analysis, respectively. CONCLUSION: Overall, these results suggest that FL may be considered an efficacious intervention for Sco- and EtOH-induced dementia, in terms of reversing cognitive impairment and neuroplastic dysfunction.
Subject(s)
Animals , Mice , Acetylcholine , Acetylcholinesterase , Alanine Transaminase , Aspartate Aminotransferases , Blotting, Western , Brain , Cholesterol , Cognition Disorders , Cyclic AMP Response Element-Binding Protein , Dementia , Drug Therapy , Ethanol , Extracellular Signal-Regulated MAP Kinases , Functional Food , Hippocampus , Immunohistochemistry , Laminaria , Memory , Neurodegenerative Diseases , Neuronal Plasticity , Neuroprotective Agents , Receptors, Muscarinic , Scopolamine , Triglycerides , United Nations , WaterABSTRACT
Objective To investigate the effect of hypothermia on the learning and memory a-bility of neonatal rats during anesthesia and its possible mechanism.Methods Forty SD rats aged 7 d were randomly divided into 4 groups (n=10):control group (group C),anesthesia group (group A),anesthesia and hypothermia group (group AH),hypothermia group (group H).Group C was in-jected intraperitoneally with 0.1 ml of saline and equipped with heating pad to keep the rectal temper-ature at 38-39℃.Group A was injected with propofol 0.1 ml at 25 mg/kg intraperitoneally with 1/2 of the initial dose,and anesthesia was maintained for 2 h.The same method to maintain the rectal temperature at 38-39℃;Group AH of anesthesia and time and Group A of the same,rats in the anes-thesia process is not insulation,control room temperature of 23℃,allowing the body temperature de-creased;Group H rats intraperitoneal injection of 0.1 ml saline,the same control room temperature of 23℃,so that the natural temperature drop.Anesthesia in the process of continuous oxygen,inter-mittent monitoring of body temperature.Immediately after awake,5 rats in each group were randomly selected to detect the content of p-ERK and p-CREB in hippocampus by Western blot.The spatial learning and memory ability and p-ERK and p-CREB contents in hippocampus were measured by water maze test.Results The rectal temperature in group AH and group H decreased to (25.38± 0.22)℃ and (25.54±0.20)℃ in 1 h respectively,and the body temperature decreased significantly compared with group C(38.36±0.24)℃ and group A(37.40±0.29)℃ (P<0.05).Compared with group C and group A,the expression of group AH and group H was decreased (P<0.05).At the end of the water maze test,the expression of protein in the four groups was not statistically signifi-cant.There was no significant difference between the four groups in the escape latency,the number of crossing the platform and the quadrant of the original platform quadrant.Conclusion The expression of p-ERK and p-CREB in neonatal rats hippocampus can be short-term inhibition in the period of hy-pothermia at 25℃,but no significant effect on the long-term learning and memory ability.
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Objective To evaluate the effect of sevoflurane on hippocampal cyclic AMP (cAMP)-protein kinase A (PKA)-cAMP response element-binding protein (CREB) signaling pathway in aged rats.Methods Sixty healthy aged male Sprague-Dawley rats,aged 18 months,weighing 600-750 g,were divided into control group (C group,n =30) and sevoflurane group (group Sev,n =30) using a random number table method.Group Sev inhaled 2％ sevoflurane for 4 h.Group C inhaled the mixture of 50％ air and oxygen (2 L/min) for 4 h.Morris water maze test was performed on 1-6 days before anesthesia and at 1 day after the end of anesthesia (at the corresponding time points in group C).The animals were sacrificed and hippocampi were removed at 1,3 and 7 days after anesthesia (at the corresponding time points in group C) for determination of the hippocampal cAMP content (using enzyme-linked immunosorbent assay) and expression of hippocampal CREB,phosphorylated CREB (p-CREB) and PKA (using Western blot),and the p-CREB/CREB ratio was calculated.Results Compared with group C,the escape latency and swimming distance were significantly prolonged,the frequency of crossing the original platform was decreased,the time of staying at the original platform quadrant was shortened at 1 day after the end of anesthesia,and the expression of hippocampal cAMP and PKA was down-regulated at 1,3 and 7 days after the end of anesthesia,and the expression of CREB and p-CREB was down-regulated and p-CREB/CREB ratio was decreased at 1 day after the end of anesthesia in group Sev (P＜ 0.05).Conclusion The mechanism of sevoflurane-induced postoperative cognitive dysfunction may be related to inhibiting hippocampal cAMP-PKA-CREB signaling pathway in aged rats.
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RESUMO Introdução: Novos estudos de regulação gênica do exercício físico por meio de técnicas pós-genômicas em ensaios de resistência (endurance) e força caracterizam a transcriptômica do exercício físico. Entre os genes afetados, destacamos a via da proteína quinase ativada por AMP (AMPK), cuja ativação ocorre durante o exercício como resultado das alterações dos níveis de fosfato energético da fibra muscular. Objetivo: Avaliar a via de sinalização da AMPK por revisão sistemática da expressão de genes e análise in silico. Método: Foi efetuada uma revisão sistemática para avaliar a regulação gênica da via de sinalização AMPK, caracterizando os genes estudados na literatura, as variações de regulação obtidas, na forma de fold change e tipos de exercício usados. Resultados: A via de sinalização AMPK mostrou 133 genes no repositório KEGG (Kyoto Encyclopedia of Genes and Genomes), os quais foram confrontados com a revisão sistemática da literatura, totalizando 65 genes. Dezessete genes apresentaram UR e 24 mostraram DR com relação ao seu respectivo controle. Além destes, 20 genes estavam presentes nos trabalhos, apresentando tanto UR e DR e quatro genes não apresentaram dados de regulação. Verificou-se regulação específica em função do tipo de exercício efetuado. Discussão: Dos 133 genes da via AMPK, 48,8% foram amostrados nos trabalhos revisados, indicando que uma parte significativa da via é regulada pelo exercício. O estudo apresentou a regulação gênica básica de dois mecanismos para a recuperação energética, a biogênese mitocondrial e o bloqueio da gliconeogênese. Conclusão: Este trabalho mostrou que o exercício atua ativamente na via de sinalização da AMPK, na importância da regulação via PGC-1α e no papel de outros genes, regulando a expressão de mais da metade dos genes amostrados.
ABSTRACT Introduction: New studies of gene regulation by physical exercise through post-genomic techniques in endurance and strength tests characterize the physical exercise transcriptomics. Among the affected genes, we highlight the AMP-activated protein kinase (AMPK) pathway, the activation of which occurs during exercise because of changes in muscle fiber energetic phosphate levels. Objective: To evaluate the AMPK signaling pathway by systematic review of gene expression and in silico analysis. Method: A systematic review was performed in order to assess the gene regulation of AMPK signaling pathway, characterizing the genes studied in the literature, regulation variations obtained in the form of fold change, and types of exercise performed. Results: The AMPK signaling pathway showed 133 genes in the KEGG repository (Kyoto Encyclopedia of Genes and Genomes), which were compared with the systematic review of the literature, totaling 65 genes. Seventeen genes presented UR and 24 showed DR in relation to their respective control. In addition to these, 20 genes were present in the literature, presenting both UR and DR and four genes showed no regulatory data. Specific regulation was verified according to the type of exercises performed. Discussion: Of the 133 genes of the AMPK pathway, 48.8% were sampled in the revised studies indicating that a significant part of the pathway is regulated by exercise. The study presented the basic gene regulation of two mechanisms for energy recovery, mitochondrial biogenesis, and gluconeogenesis blockade. Conclusion: This work showed that the exercise actively works in the AMPK signaling pathway, in the importance of regulation via PGC-1α and in the role of other genes, regulating the expression of more than half of the genes sampled.
RESUMEN Introducción: Nuevos estudios de regulación génica del ejercicio físico por medio de técnicas pos-genómicas en ensayos de resistencia (endurance) y fuerza caracterizan la transcriptómica del ejercicio físico. Entre los genes afectados, destacamos la vía de la proteína quinasa activada por AMP (AMPK), cuya activación ocurre durante el ejercicio como resultado de las alteraciones de los niveles de fosfato energético de la fibra muscular. Objetivo: Evaluar la vía de señalización AMPK por revisión sistemática de la expresión de genes y análisis in silico. Método: Se ha efectuado una revisión para evaluar la regulación génica de la vía de señalización AMPK, caracterizando los genes estudiados en la literatura, las variaciones de regulación obtenidas en forma de fold change y tipos de ejercicios utilizados. Resultados: La vía de señalización AMPK mostró 133 genes en el repositorio KEGG (Kyoto Encyclopedia of Genes and Genomes), los cuales fueran confrontados con la revisión sistemática de la literatura, totalizando 65 genes. Diecisiete genes presentaron UR y 24 mostraron DR con respecto a su respectivo control. Además de estos, 20 genes estaban presentes en los trabajos, presentando tanto UR y DR y cuatro genes no presentaron dados de regulación. Se observó una regulación específica en función del tipo de ejercicio efectuado. Discusión: De los 133 genes de la vía AMPK, 48,8% fueron muestreados en los trabajos revisados, indicando que una parte significativa de la vía es regulada por el ejercicio. El estudio presentó la regulación génica básica de dos mecanismos para la recuperación energética, la biogénesis mitocondrial y el bloqueo de la gluconeogénesis. Conclusión: Este trabajo mostró que el ejercicio actúa activamente en la vía de señalización AMPK, en la importancia de la regulación vía factor PGC-1a y en el papel de otros genes, regulando la expresión de más de la mitad de los genes muestreados.