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OBJECTIVE To investigate the effect and mechanism of α7 nicotinic acetylcholine receptor （α7nAChR） agonists PNU-282987 on cognitive function in temporal lobe epilepsy （TLE） model rats. METHODS Sixty rats were randomly divided into control group， model group， PNU-282987 group （3 mg/kg） and methyllycaconitine （MLA）+PNU-282987 group （6 mg/kg MLA+3 mg/kg PNU-282987）， with 15 rats in each group. Except for control group， the TLE model was established in the other groups. After the model was successfully established， each group was given relevant medicine or normal saline intraperitoneally， once a day， for two consecutive weeks. The epilepsy attack of rats was observed and scored， and the duration of seizures was recorded； the cognitive function of rats was detected； pathological morphology of neurons in CA1 region was observed； the levels of tumor necrosis factor-α （TNF-α）， interleukin-6 （IL-6） and IL-1β in the hippocampus were detected； the positive expressions of ionized calcium-binding adapter molecule-1 （IBA-1）， α7nAChR， nuclear factor-κB （NF-κB） p65， p-NF-κB p65 in the hippocampus were detected. RESULTS Compared with model group， the score and duration of seizures， the number of IBA-1 positive cells， the levels of TNF- α， IL-6 and IL-1β， the expressions of NF- κB p65 and p-NF- κB p65 protein decreased significantly in the hippocampus （P＜0.05）； the escape latency time was shortened significantly （P＜0.05）， the time spent in the original platform quadrant and times of crossing the platform increased significantly （P＜0.05）； neuronal damage in the CA1 region of the hippocampus was significantly reduced； the expression of α7nAChR protein increased significantly in hippocampus （P＜0.05）. Compared with PNU-282987 group， the above indexes of rats in MLA+PNU-282987 group were reversed significantly （P＜0.05）. CONCLUSIONS PNU-282987 could improve cognitive dysfunction in TLE model rats， and its mechanism may be associated with inhibiting microglia-mediated inflammatory response through α7nAChR/NF- κB signaling pathway， thus reducing hippocampal neuronal damage.
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OBJECTIVE：To st udy the effects of α7 nicotinic acetylcholine receptor agonists （PNU282987）on improving cardiac remodeling of mice and Janus kinase 2/signal transducer and activator of transcription 3（JAK2/STAT3）signaling pathway. METHODS：Male Kunming mice were randomly divided into normal control group ，model group ，propranolol group （positive control，i.g. 40 mg/kg）and PNU 282987 low-dose，medium-close and high-dose groups （intraperitoneal injection of 0.5，1.0，3.0 mg/kg），with 10 mice in each group. Except for the normal control group ，mice in the other groups were given isoproterenol （ISO，30 mg/kg） subcutaneously for 7 days to induce the cardiac remodeling model. After 30 minutes of ISO injection ， administration groups were given relevant liquid ，once a day ，for 7 consecutive days. Twelve hours after last administration ，the left ventricular ejection fraction （EF）and left ventricular short axis shortening rate （FS）of mice in each group were measured ，and the whole heart mass index （HMI）was calculated ；the pathological changes of myocardium were observed. The serum contents of lactate dehydrogenase （LDH），creatine kinase （CK），tumor necrosis factor α（TNF-α），interleukin 6（IL-6），the protein expression of intercellular adhesion molecule 1（ICAM-1）and adhesion molecule 1（VCAM-1）were also determined. The ratios of p-JAK2/JAK2，p-STAT3/STAT3 in myocardial tissue were detected. RESULTS ：Compared with normal control group ，EF and FS of model group were significantly reduced ，HMI，the contents of LDH，CK，TNF-α and IL-6，the protein expression of ICAM- 1 and VCAM- 1，the ratio of p-JAK 2/JAK2 and p-STAT 3/STAT3 were increased significantly （P＜0.05 or P＜0.01）； blue collagen deposition in the interstitium of myocardium was obvious，and the degree of fibrosis was severe. Compared with model group ， the EF and FS of the mice in the medium-dose and high-dose groups were increased significantly ， HMI （except for PNU 282987 medium-dose group ），the contents of LDH （except for PNU 282987 medium-dose group ），CK，TNF-α and IL-6，the protein expression of ICAM- 1 and VCAM- 1，the ratio of p-JAK 2/JAK2 and p-STAT 3/STAT3 were decreased significantly （P＜0.05 or P＜ 0.01）；blue collagen deposition in the myocardial interstitium was significantly reduced ，and the degree of myocardial fibrosis was significantly reduced. There was no significant difference in the comparison of the above indicators in PNU 282987 low-dose group （P＞0.05）. CONCLUSIONS ：PNU282987 can improve cardiac remodeling of mice ，the mechanism of which may be associated with inhibiting JAK 2/STAT3 signaling pathway.
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@#To investigate the neuroprotective effect and possible molecular mechanism of PNU-282987 on rats subjected to ischemia and reperfusion. In this study, middle cerebral artery occlusion/reperfusion(MCAO/R)in rats was used as the animal model. The 44 Sprague-Dawley(SD)rats were divided into 4 groups, sham group, model group, low-dose of PNU-282987(1. 2 mg/kg)and high-dose of PNU-282987(2. 4 mg/kg)treatment group. Y-maze test was tested for the learning and memory abilities of rats, and we also examined the brain infarct size, brain edema and neurological dysfunction in rats. Furthermore, HE staining was used to evaluate the neuronal injury and TUNEL assay was used to evaluate the neuronal apoptosis in the rat brain. The results revealed that the learning and memory abilities of rats in treatment group improved significantly, and treatment with PNU-282987 reduced brain infarct size, lessoned brain edema, lessened neurological dysfunction, ameliorated pathological injury and prevented neuronal apoptosis. The above results suggest that the underlying mechanism of PNU-282987 on improving learning and memory abilities of rats after cerebral ischemia and reperfusion may include the inhibition of neuronal apoptosis.
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BACKGROUND AND OBJECTIVES: Alzheimer’s disease (AD) is the most common form of dementia among older persons. Thymoquinone (TQ) has anti-inflammatory, anticonvulsant and antioxidant activity. A novel α7 nicotinic acetyl choline receptor (α7 nAChR ) agonist (PNU- 282987) have been identified to enhance the cognitive performance. An alternative treatment strategy via compounds known as nicotinic “positive allosteric modulators” (PAMs) has been reported. This study was designed to investigate the combination of PAM of α7 nAChRs with PNU- 282987 or with TQ as a possible treatment for AD in rat. METHODS: 48 male albino rats were divided into 4 groups. Group I (Control), Group II received lipopolysaccharide, 0.8 mg/kg by intraperitoneal injection (IPI) once, Group III received TQ 10 mg/kg by IPI, Group IV received PNU-120596 1 mg/kg by IPI, in addition to PNU-282987 1 mg/kg by IPI in subgroup IVa and TQ in subgroup b. All treatment drugs were given for 5 days. RESULTS: Acidophilic masses, deformed neurons, Congo red +ve masses and reduced Phospho-CREB immunoexpression were seen in group II. All changes regressed by treatment. Some CD44 +ve cells were noticed in group II and few +ve cells in subgroup IVa, that became multiple in group III and subgroup IVb. The histological, histochemical and immunohistochemical changes were confirmed statistically and significant differences were recorded. CONCLUSIONS: TQ or α7 nAChR agonist combined with PAM can have an important role in treatment of AD that is superior to thymoquinone alone. Exceptionally, TQ single or combined with PAM proved activation of MSC.