Effect of edaravone on ERK-CREB signaling pathway in hippocampus of aged rats with postoperative cognitive dysfunction / 中华麻醉学杂志

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.

Effect of surgery under propofol anesthesia during mid-pregnancy on cognitive function and hippocampal HDAC2-CREB-NR2B signaling pathway in offspring rats / 中华麻醉学杂志

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.

Nerve repair effect of olanzapine-mediated cyclic AMP response element binding protein/brain-derived neurotrophic factor/receptor tyrosine kinase receptors B pathway on schizophrenic rats / 解剖学报

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.

Hypothesis on ontogenesis and pathophysiology of Alzheimer's disease

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.

Role of PKA-CREB signaling pathway in sevoflurane-induced reduction of cognitive impairment caused by cardiopulmonary bypass in rats / 中华麻醉学杂志

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.

Role of p38 MAPK/CREB signaling pathway in tetramethylpyrazine-induced reduction of hippocampal inflammatory responses in mice with sepsis-associated encephalopathy / 中华麻醉学杂志

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.

Role of ERK1/2/CREB/BDNF signaling pathway in dexmedetomidine-induced inhibition of propofol-caused apoptosis in isolated hippocampal neurons of fetal rats / 中华麻醉学杂志

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.

Effects of upregulation of CREB on proliferation, invasion and NK cell killing activity of esophageal adenocarcinoma / 中国医师杂志

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.

Amitriptyline inhibits the MAPK/ERK and CREB pathways and proinflammatory cytokines through A3AR activation in rat neuropathic pain models / 대한마취과학회지

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.

Effects of hypothermia on learning and memory ability of neonatal rats during anesthesia / 临床麻醉学杂志

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.

Effect of sevoflurane on hippocampal cAMP-PKA-CREB signaling pathway in aged rats / 中华麻醉学杂志

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.

Role of cAMP-PKA-CREB signaling pathway in hypoxic preconditioning-induced reduction of propofol-induced central neurotoxicity in developing rats / 中华麻醉学杂志

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.

GABA-enriched fermented Laminaria japonica improves cognitive impairment and neuroplasticity in scopolamine- and ethanol-induced dementia model mice

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.

Relationship between hippocampal CREB/BDNF signaling pathway and cognitive dysfunction in rats with chronic pathological pain / 中华麻醉学杂志

Objective To evaluate the relationship between hippocampal cyclic adenosine monophosphate response element-binding protein(CREB)/brain-derived neurotrophic factor(BDNF)signaling pathway and cognitive dysfunction in rats with chronic pathological pain.Methods Thirty-two healthy adult male Sprague-Dawley rats,weighing 220-250 g,were divided into 3 groups using a random number table:control group(group C,n=8),sham operation group(group S,n=8)and chronic pathological pain group(group CP,n=16).Chronic pathological pain model was established by injecting cobra venom 0.4 mg(4 μl)into the sheath of the infraorbital nerve.The mechanical pain threshold was measured at 3 days before establishment of the model(baseline)and 4 days and 1,2,3,4 and 8 weeks after establishment of the model.Morris water maze test was performed to evaluate the spatial learning and memory abilities at 5 and 9 weeks after establishment of the model.Eight rats were sacrificed at 5 and 9 weeks after establishment of the model in CP group,and rats were sacrificed after the end of Morris water maze test at 9 weeks after establishment of the model in C and S groups.The hippocampi were isolated for determination of the expression of phosphorylated CREB and BDNF in the hippocampal tissues using Western blot.Results Compared with group C,the mechanical pain threshold was significantly decreased at each time point after establishment of the model,the escape latency was prolonged at 5 and 9 weeks after establishment of the model,the rate of time of staying at the target quadrant was decreased,the frequency of crossing the original platform was decreased,and the expression of phosphorylated CREB and BDNF was down-regulated at 9 weeks after establishment of the model in group CP(P0.05).Conclusion The mechanism underlying cognitive dysfunction may be related to inhibited activation of CREB/BDNF signaling pathway in the hippocampus of rats with chronic pathological pain.

Effect of sevoflurane on hippocampal CaMK Ⅱ/CREB signaling pathway in aged rats / 中华麻醉学杂志

Objective To evaluate the effect of sevoflurane on hippocampal calcium/calmodulindependent protein kinase Ⅱ (CaMK Ⅱ)/cyclic adenosine monophosphate response element-binding protein (CREB) signaling pathway in aged rats.Methods Sixty pathogen-free healthy male Sprague-Dawley rats,aged 18 months,weighing 600-750 g,were divided into 2 groups (n=30 each) using a random number table:control group (group C) and sevoflurane group (group Sev).Group Sev inhaled 2％ sevoflurane in the mixture of 50％ air and oxygen (2 L/min) 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 6 days before anesthesia and 1 day after anesthesia.The escape latency,swimming distance,frequency of crossing the original platform and time of staying at the platform quadrant Ⅱ were recorded.On 1,3 and 7 days after anesthesia,the rats were sacrificed,and the hippocampus was obtained for determination of the expression of CaMK Ⅱ,phosphorylated CaMK Ⅱ,CREB and phosphorylated CREB by Western blot.Results Compared with group C,the escape latency and swimming distance were significantly prolonged,the frequency of crossing the original platform was decreased,and the time of staying at the platform quadrant Ⅱ was reduced on 5th day of training and 1 day after anesthesia,and the expression of CaMK Ⅱ,phosphorylated CaMK Ⅱ,CREB and phosphorylated CREB was down-regulated after anesthesia in group Sev (P＜ 0.05).Conclusion Sevoflurane leads to cognitive decline through inhibiting hippocampal CaMK Ⅱ/CREB signaling pathway in aged rats.

Variation of CREB and NMDAR1 Proteins Induced by Auditory Deprivation and Intracochlear Electrical Stimulation in Infant Rats / 听力学及言语疾病杂志

Objective To observe the expression of cAMP -response element binding protein (CREB) and N-methyl-D-aspartic acid receptor (NMDA ) after intracochlear electrical stimulation in the auditory cortex and inferior colliculus in infant rats with auditory deprivation .Methods Sixty six SD infant rats were randomly divided into 6 groups (11 rats each group):4 weeks ,and 6 weeks after injection of ototoxic drug ,the control group ,and 3 weeks and 5 weeks after injection of ototoxic drug with intra -cochlear electrical stimulation for one week .Gentami-cin sulphate (350 mg/kg body weight) and frusemide (200 mg/kg body weight) were injected subcutaneously in the skin folds on the lateral abdominal side and the dorsal neck area ,respectively .The expression of CREB and NMDAR1protein were detected by immunohistological staining .Results The results of immunohisto -chemistry revealed that protein expression of CREB and NMDAR1 in 4 week group of injection increased as compared to the control group ,while decreasing as compared to intracochlear electrical stimulation group ,significantly .However ,protein expression of CREB and NMDAR1 in 6 week group of injection decreased as compared to the control group and in-tracochlear electrical stimulation group ,significantly .Conclusion Auditory deprivation could result in the expres-sion of protein of CREB and NMDAR1 in auditory cortex and inferior colliculus increasing in an early stage and then de-creasing in infant rats .Intracochlear electrical stimulation could result in the expression of proteins of CREB and NMDAR 1 in auditory cortex and inferior colliculus increasing in infant rats .The dynamic variation of CREB and NMDAR1 expression in rat auditory cortex and inferior colliculus reflects synaptic plasticity in neurons of auditory pathway .

Effects of Electroacupuncture at Shenting and Baihui on Learning and Memory, and Expression of Cyclic AMP Response Element Binding Protein and Phosphorylation in Rats with Cerebral Ischemia-reperfusion / 中国康复理论与实践

@#Objective To explore the effects of electroacupuncture at Shenting (DU24) and Baihui (DU20) on cognitive dysfunction after stroke. Methods Forty-five Sprague-Dawley rats were randomly divided into control group (n=15), model group (n=15) and electroacupuncture group (n=15). The latter two groups were occluded their middle cerebral artery for two hours and reperfused. The electroacupuncture group accepted electroacupuncture at Shenting and Baihui 24 hours after modeling for seven days. They were assessed with Morris water maze once a day since the second day of intervention. Their brains were stained with TTC staining to measure cerebral infarction volume after treatment, while the expression of cyclic AMP response element binding protein (CREB) and phosphorylation (p-CREB) in hippocampal CA1 area were detected with immunohistochemistry. Results The escape latency and swimming distance of place navigation shortened in the electroacupuncture group compared with those in the model group (P<0.05) from the fourth day of intervention. The number of cross platform of spatial probe increased (P<0.05). The infarction volume was less in the electroacupuncture group than in the model group (P< 0.05), with increased expression of CREB and p-CREB in hippocampal CA1 area (P<0.05). Conclusion Electroacupuncture at Shenting and Baihui can increase the expression of CREB and phosphorylation in hippocampal CA1 area in rats after cerebral ischemia-reperfusion, to protect the neurons from ischemia and improve the learning and memory function.

Protective Effect of Administered Rolipram against Radiation-Induced Testicular Injury in Mice

PURPOSE: Pelvic irradiation for the treatment of cancer can affect normal cells, such as the rapidly proliferating spermatogenic cells of the testis, leading to infertility, a common post-irradiation problem. The present study investigated the radioprotective effect of rolipram, a specific phosphodiesterase type-IV inhibitor known to increase the expression and phosphorylation of the cyclic adenosine monophosphate response element-binding protein (CREB), a key factor for spermatogenesis, with the testicular system against pelvic irradiation. MATERIALS AND METHODS: Male C57BL/6 mice were treated with pelvic irradiation (2 Gy) and rolipram, alone or in combination, and were sacrificed at 12 hours and 35 days after irradiation. RESULTS: Rolipram protected germ cells from radiation-induced apoptosis at 12 hours after irradiation and significantly increased testis weight compared with irradiation controls at 35 days. Rolipram also ameliorated radiation-induced testicular morphological changes, such as changes in seminiferous tubular diameter and epithelial height. Additionally, seminiferous tubule repopulation and stem cell survival indices were higher in the rolipram-treated group than in the radiation group. Moreover, rolipram treatment counteracted the radiation-mediated decrease in the sperm count and mobility in the epididymis. CONCLUSIONS: These protective effects of rolipram treatment prior to irradiation may be mediated by the increase in pCREB levels at 12 hours post-irradiation and the attenuated decrease in pCREB levels in the testis at 35 days post-irradiation in the rolipram-treated group. These findings suggest that activation of CREB signaling by rolipram treatment ameliorates the detrimental effects of acute irradiation on testicular dysfunction and the related male reproductive functions in mice.

Role of PDGFR-βsignal pathway in morphine tolerance / 医学研究生学报

Objective Beta platelet-derived growth factor receptor ( PDGFR-β)-mediated signaling plays a key role in mor-phine tolerance , but its molecular mechanisms are not yet completely understood .The present study aims to investigate whether the ex-tracellular signal-regulated kinase ( ERK) and cyclic AMP response element binding protein ( REB) signaling pathways are involved in the development of PDGFR-βactivation-induced morphine tolerance in rats . Methods Thirty-six adult male SD rats were randomly divided into six groups of equal number:normal saline (20μL), morphine (15μg), morphine +imatinib (morphine 15μg +ima-tinib 10μg), morphine +PDGF-BB (morphine 15μg +PDGF-BB 10 ng), imatinib (10μg), and PDGF-BB (10 ng), all treated intrathecally at 20μL once daily for 7 consecutive days .Paw withdrawal latency ( PWL ) was measured 1 d before and 30 min after medication at 1, 3, 5, and 7 days, respectively, followed by calculation of the maximal possible effect of analgesia (MPE).On the 8th day, PWL was again obtained from all the rats at 30 min after intrathecal injection of morphine (15μg).Then, all the animals were sacrificed and the L4-5 segment of the spinal cord was isolated for determination of the expressions of ERK , phosphorylated ERK ( p-ERK) , CREB, and phosphorylated CREB ( p-CREB) by Western blot. Results At 5 and 7 days after medication, MPE was significant decreased in the morphine group ([52.90 ±8.20] and [15.12 ±3.80] %) and the morphine +PDGF-BB group ([43.51 ±5.42] and [14.81 ±3.60] %) as compared with (100.00 ± 0.00) %in both groups at 1 day (P<0.05), but had no significant changes in the morphine +imatinib group at 1, 3, 5, and 7 days.After intrathecal injection of morphine on the 8th day, MPE was (16.22 ±2.51) %in the morphine group, (15.22 ±3.50) %in the morphine +PDGF-BB group, and (35.21 ±4.51) %in the PDGF-BB group, all remarkably lower than (100.00 ±0.00) %in the control group (P<0.05).There were no significant differences in the expression levels of ERK and CREB among the six groups.The expressions of spinal p-ERK and p-CREB were markedly increased in the morphine , morphine +PDGF-BB, and PDGF-BB groups as compared with the control group (P<0.05), but significantly decreased in the morphine +imatinib group in compari-son with the morphine group, (P<0.05). Conclusion The PDGFR-βsignaling pathway plays an important role in the develop-ment of tolerance to morphine-induced analgesia and its underlying mechanisms may be associated with the activation of the ERK and CREB pathways .

Infusion of clenbuterol into infralimbic cortex attenuates cue-induced reinstatement of heroin-seeking behavior / 中国药理学与毒理学杂志

OBJECTIVE To investigate the effect of injection of β2-adrenergic receptor agonist clenbuterol into the infralimbic cortex(IL) on drug-seeking behavior triggered by conditioned cues. METHODS Adult male SD rats were trained to self-administer heroin under a FR1 schedule for consecutive 14 d,followed by 2-h extinction training. Cue-induced heroin seeking was measured for 2 h. Clenbuterol was microinjected bilaterally into the IL(8 ng/side)of rats 15 min prior to reinstatement test. Meanwhile,locomotor activity was detected 15 min after clenbuterol or artifial cerebrospinal fluid(mod?el group) was microinjected bilaterally into IL. Western blotting was used to detect the expression of phosphorylated cyclic AMP response element-binding protein(p-CREB)in the prelimbic cortex(PL), IL,nucleus accumbens core (NACc) and shell (NACsh) of rats immediately after reinstatement test. RESULTS After heroin administration training for 14 consecutive days,these animals exhibited reliable heroin self-administration,indicated by the increase in active nose poke responses and infusions. The rats that had received infusion of clenbuterol into the IL had significantly lower active pokes (8 ± 3)than those in model group(45±10)in cue-induced reinstatement(P<0.01),but there was no significant differ?ence between clenbuterol group and vehicle group in the locomotor activity. The expression of p-CREB in either IL or NACsh was significantly decreased in clenbuterol group compared with model group(P<0.01,P<0.05),but significantly increased in NACc(P<0.01). CONCLUSION Microinjection of clenb?uterol into the IL can attenuate the cue-induced reinstatement of heroin-seeking behavior in rats. The underlying mechanism might be related to the regulation of p-CREB expression in the NACc and NACsh.