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Abstract: Alzheimer''s disease (AD) a progressive neurodegenerative disorder of later life, is characterized by brain deposition of amyloid β-protein (Aβ) plaques, accumulation of intracellular neurofibrillatory tangles, synaptic loss and neuronal cell death. There is significant evidence that oxidative stress is a critical event in the pathogenesis of AD. In the present study Aβ formation was induced in NT2N neurons, one of the most appropriate cell line models in AD. Our results indicate that oxidative stress resulting from the treatment of H2O2/FeSO4 and/or 4-hydroxy-2-noenal (HNE) can be inhibited in the presence of tBHQ, a known inducer of nuclear factor-erythroid 2 related factor 2 (Nrf2) in NT2N neurons and can therefore be used to elucidate the relationship between oxidative stress, Aβ formation and Nrf2. The role of Nrf2 was confirmed using retinoic acid as an inhibitor of Nrf2. It provides the first documentation that tBHQ not only protects the neurons against cell death but also decreases amyloid β formation. Moreover, the results indicate that oxidative stress fosters Aβ formation in NT2N neurons, creating a vicious neurodegenerative loop. [Copyright &y& Elsevier]

Abstract: Reported here is the overexpression, purification and partial characterization of recombinant coxsakievirus B3 2A protease (CVB3 2Apro) from bacterial cells transformed with a plasmid containing the CVB3 2Apro cDNA sequences. The structural investigation showed that the protein contains mostly β-strand elements and requires Zn2+ ions as a structural component which appeared to be inhibitory if added exogenously. The purified enzyme activity was optimal at 4°C and had a short half-life at physiological temperature. This feature can be the result of the presence of a high content of β-structure and also hydrophobic residues in its structure. [Copyright &y& Elsevier]

Reteplase is a deleted variant of human tissue plasminogen activator with a complex structure containing nine disulfide bonds. Reteplase is expressed as inclusion bodies in Escherichia coli and needs the additional step of refolding for activation. In this study an experimental design was performed to find the optimal refolding condition for reteplase. The influence of 14 chemical additives was assessed by one factor at a time method and then Taguchi design followed by response surface methodology was employed to find compounds with most significant effects on reteplase refolding and their optimum concentration. We found that 0.13 M histidine, 1.64 M methionine, 0.33 M cysteine, and 0.34 M arginine in addition to the GSH/GSSG is the optimal condition for refolding of reteplase. We also investigated the refolding yield for inclusion bodies obtained from different E. coli strains and found that BL21 (DE3) has the best recovery yield in comparison to Rosetta-gami and Shuffle T7. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: There are some evidences indicating that stress can affect hippocampal survival and function. During pregnancy mother is exposed to more stress and anxiety; also adrenal gland response to ACTH and glucocorticoid secretion is increased. Hence this study was done to assess the effect of restraint stress on corticosterone level, hippocampal caspase-3 and MAPK activation during pregnancy. Study design: The restraint stress was applied in day 14 or days 14–20 (single and repeated stress) of rats’ pregnancy. The hippocampi were isolated after last stress episode and western blot analysis was done to assess caspase-3 and MAPK activation. Data were analyzed by one-way ANOVA followed by Student–Newman–Keuls for multiple comparison. Results: Our study showed that single and repeated stress both increase corticosterone level compared to non-stressed pregnant rats, but do not induce hippocampal apoptosis. Single stress increases transient JNK activation but not P38 and ERK. Repeated stress activated none of the MAPKs. Conclusion: It seems that pregnancy protects mother''s hippocampus against stress-induced damages. [Copyright &y& Elsevier]

• Peripheral inflammatory pain increased the microglia dependent proBDNF/BDNF ratio in the hippocampus. • An increase of the microglia dependent proBDNF/BDNF ratio led to neurons death in the hippocampus. • The hippocampal cell death impaired spatial learning and memory following Peripheral inflammatory pain. Inflammatory pain is commonly associated with cognitive impairment. However, its molecular mechanisms are poorly understood. Thus, this study was conducted to investigate the molecular mechanisms of behavioral changes associated with inflammatory pain. Briefly, 36 Wistar rats were randomly divided into two main groups: CFA group treated with 100 μL of Complete Freundsʼ Adjuvant (CFA) and CFA + Minocycline group treated with 100 μL of CFA+40 mg/kg/day of minocycline). After that, each group was divided into three subgroups based on different time points of the study. The pain was induced using CFA and subsequent behavioral changes (i.e., hyperalgesia and learning and spatial memory) were analyzed by the Morris Water Maze (MWM) task and Radiant Heat. Then, the cellular and molecular changes were assessed using Western Blotting, Immunohistochemistry, and Terminal deoxynucleotidyl transferase dUTP Nick End Labeling (TUNEL) techniques. Results of the study indicated that CFA-induced pain impaired spatial learning and memory functions. Studying the cellular changes showed that persistent inflammatory pain increased the microglial activity in CA1 and Dentate Gyrus (DG) regions. Furthermore, an increase was observed in the percentage of TUNEL-positive cells. Also, pro-Brain-Derived Neurotrophic Factor (BDNF)/BDNF ratio, Caspase3, and Receptor-Interacting Protein kinase 3 (RIP3) levels increased in the rats' hippocampus following induction of persistent inflammatory pain. These changes were reversed following the cessation of pain as well as the injection of minocycline. Taking together, the results of the current study for the first time revealed that an increase in the microglia dependent proBDNF/BDNF ratio following persistent inflammatory pain leads to cell death of the CA1 and DG neurons that subsequently causes a cognitive deficit in the learning and spatial memory functions. [ABSTRACT FROM AUTHOR]

Highlights • i.p. administration of CEPO-Fc prevents Aβ 25–35 -induced spatial learning and memory impairment. • Aβ 25–35 -mediated memory loss is associated with MAPKs (P38, ERK, JNK) hyperactivity and MMP-2 overexpression in hippocampus. • Memory deterioration induced by Aβ 25–35 is related to disruption in Akt/GSK-3β signaling. • i.p. CEPO-Fc treatment reverses the effect of Aβ 25–35 on hippocampal P38, ERK, Akt/GSK-3β and MMP-2. Abstract Alzheimer’s disease (AD) is a debilitating neurodegenerative disease, characterized by extracellular deposition of senile plaques, mostly amyloid β-protein (Aβ) and neuronal loss. The neuroprotective effects of erythropoietin (EPO) have been reported in some models of neurodegenerative disease, but because of its hematopoietic side effects, its derivatives lacking hematopoietic bioactivity is recommended. In this study, the neuroprotective effects of carbamylated erythropoietin-Fc (CEPO-Fc) against beta amyloid-induced memory deficit were evaluated. Adult male Wistar rats weighing 250–300 g were bilaterally cannulated into CA1. Aβ 25–35 was administered intrahippocampally for 4 consecutive days (5 μg/2.5 μL/each side/day). CEPO-Fc (500 or 5000 IU) was injected intraperitoneally during days 4–9. Learning and memory performance of rats was assessed on days 10–13 using Morris Water Maze, then hippocampi were isolated and the amount of activated forms of hippocampal MAPKs’ subfamily, Akt/GSK-3β and MMP-2 were analyzed using Western blot. From the behavioral results, it was revealed that CEPO-Fc treatment in both 500 and 5000 IU significantly reversed Aβ-induced learning and memory deterioration. From the molecular analysis, an increment of MAPKs and MMP-2 activity and an imbalance in Akt/GSK-3β signaling after Aβ 25–35 administration was observed. CEPO-Fc treatment prevented the elevation of hippocampal of P38, ERK, MMP-2 activity and also Akt/GSK-3β signaling impairment induced by Aβ 25–35 but it had no effect on JNK. It seems that CEPO-Fc prevents Aβ-induced learning and memory deterioration, and also modulates hippocampal MAPKs, Akt/GSK-3β and MMP-2 activity. This study suggests that CEPO-Fc can be considered as a potential therapeutic strategy for memory deficits like AD. [ABSTRACT FROM AUTHOR]

Alzheimer disease (AD) is a progressive neurodegenerative disease characterized by extracellular deposits of beta amyloid (Aβ) and neuronal loss particularly in the hippocampus. Accumulating evidences have implied that insulin signaling impairment plays a key role in the pathology of AD; as much as it is considered as type 3 Diabetes. MAPKs are a group of signaling molecules which are involved in pathobiology of AD. Therefore this study was designed to investigate if intrahippocampal insulin hinders Aβ-related memory deterioration, hippocampal apoptosis and MAPKs signaling alteration induced by Aβ. Adult male Sprague-Dawely rats weighing 250-300 g were used in this study. The canules were implanted bilaterally into CA1 region. Aβ25-35 was administered during first 4 days after surgery (5 μg/2.5 μL/daily). Insulin treatment (0.5 or 6 mU) was done during days 4-9. The animal's learning and memory capability was assessed on days 10-13 using Morris water maze. After finishing of behavioral studies the hippocampi was isolated and the amount of hippocampal cleaved caspase 3 (the landmark of apoptosis) and the phosphorylated (activated) forms of P38, JNK and ERK was analyzed by western blot. The results showed that insulin in 6 but not 0.5 mU reversed the memory loss induced by Aβ25-35. Western blot analysis revealed that Aβ25-35 induced elevation of caspase-3 and all 3 MAPks subfamily activity, while insulin in 6 mu restored ERK and P38 activation but has no effect on JNK. This study disclosed that intrahippocampal insulin treatment averts not only Aβ-induced memory deterioration but also hippocampal caspase-3, ERK and P38 activation. [ABSTRACT FROM AUTHOR]

Alzheimer disease (AD) is characterized by accumulation of beta amyloid (Aβ) and neuronal loss, particularly in the hippocampus. Direct central administration of this peptide was suggested as a route to create an animal model of AD. Although there are some studies indicating that a single dose of Aβ induces AD-like learning and memory impairment, this model is not usually reproducible especially in rat. Then one of the aims of this study was to explore a more reliable method to trigger AD-like behavioral impairments in rat through a series of pilot studies. In other step, according to some controversies about roles of MAPKs (P38, JNK and ERK) in AD, these kinases were assayed in beta amyloid-treated rats with or without memory impairment. A series of pilot studies was done to assess if a single Aβ injection (5, 10, 15µg/each side) induces reproducible memory impairment. Because of the failure of that set of studies, another set of experiment with repeated Aβ administration during four days was carried out. The results showed that in contrast to single treatment of beta amyloid, its repeated administration (5µg/2.5µl each side/day) during 4 days led to memory deterioration. Hippocampal western blot analysis revealed that behavioral impairment is in parallel with greater apoptosis and MAPKs activation. This study introduces a new method for inducing AD models by repeated intra-CA1 injection of Aβ25–35. Additionally it elucidates how caspase-3 and MAPKs activity differ between beta amyloid-treated rats with or without learning and memory impairment. [ABSTRACT FROM AUTHOR]

Patients with chronic pain often complain about memory impairments. Experimental studies have shown neuroprotective effects of Carbamylated erythropoietin (Cepo-Fc) in the treatment of cognitive dysfunctions. However, little is currently known about its precise molecular mechanisms in a model of inflammatory pain. Therefore, this study aimed to investigate neuroprotective effects of Cepo-Fc against cognitive impairment induced by the inflammatory model of Complete Freund's Adjuvant (CFA). Carbamylated erythropoietin was administrated Intraperitoneally (i.p) on the day CFA injection, continued for a 21-days period. After conducting the behavioral tests (thermal hyperalgesia and novel object recognition test), western blot and ELISA were further preformed on days 0, 7, and 21. The results of this study indicate that Cepo-Fc can effectively reverse the CFA induced thermal hyperalgesia and recognition memory impairment. Additionally, Cepo-Fc noticeably decreased the hippocampal microglial expression, production of hippocampal IL-1β, and hippocampal apoptosis and necroptosis induced by the inflammatory pain. Therefore, our findings suggest that neuroprotective effects of Cepo-Fc in the treatment of pain related recognition memory impairment may be mediated through reducing hippocampal microglial expression as well as IL-1β production. [ABSTRACT FROM AUTHOR]

Highlights: [•] Our study demonstrates the dominancy of Western type cagA gene in Iranian isolates. [•] We could find new EPIYA type (EPIYA-A-B/C) and new motif (QPIYP). [•] We also identified 3 sequence motifs which may be applied as genetic markers for Iranian strains. [ABSTRACT FROM AUTHOR]

Abstract: 2A protease of the pathogenic coxsackievirus B3 is key to the pathogenesis of inflammatory myocarditis and, therefore, an attractive drug target. However lack of a crystal structure impedes design of inhibitors. Here we predict 3D structure of CVB3 2Apro based on sequence comparison and homology modeling with human rhinovirus 2Apro. The two enzymes are remarkably similar in their core regions. However they have different conformations at the N-terminal. A large number of N-terminal hydrophobic residues reduce the thermal stability of CVB3 2Apro, as we confirmed by fluorescence, western blot and turbidity measurement. Molecular dynamic simulation revealed that elevated temperature induces protein motion that results in frequent movement of the N-terminal coil. This may therefore induce successive active site changes and thus play an important role in destabilization of CVB3 2Apro structure. [Copyright &y& Elsevier]

Abstract: Neuroinflammation is associated with a number of neurodegenerative diseases. It is known that lipopolysaccharide (LPS) treatment induces neuroinflammation and memory deterioration. Agmatine, the metabolite of arginine by arginine decarboxylase, is suggested to be a neuroprotective agent. The aim of this study was to explore if agmatine can prevent LPS-induced spatial memory impairment and hippocampal apoptosis. Adult male Wistar rats (200–250g) were trained in water maze for 4days (3days in hidden platform and the last day in visible platform task). Saline, LPS (250µg/kg/ip) or (and) agmatine (5 or 10mg/kg) were administered 4h before every training session. LPS treatment impaired water maze place learning while agmatine co-administration prevented it. Also western blot studies revealed that LPS induces hippocampal caspase-3 activation while agmatine treatment prevented it. [Copyright &y& Elsevier]

Abstract: Increased oxidative stress is a widely accepted factor in the development and progression of Alzheimer’s disease. Here we introduced alginate – an antioxidant oligosaccharide – as a protective agent on NT2 neural cell line against H2O2/FeSO4-induced cell death. Our results demonstrate that alginate not only protects the neurons against cell death, as measured by MTT test and caspase-3 activity determination, but also decreases amyloid β formation. In the present study we could induce Aβ formation through oxidative stress in NT2 neurons, one of the most appropriate cell line models in Alzheimer’s disease and provided the first documentation that alginate can be neuroprotective by suppressing Aβ formation. We further showed that alginate exerts its protective effect by up regulation of HO-1, γ-GCS, Hsp-70, Nrf2 and inhibiting caspase-3 and NF-κB. This study raises the possibility of developing alginate as a potential neuroprotective agent. [Copyright &y& Elsevier]

Intracerebroventricular (icv) administration of streptozotocin (STZ) has been used as a metabolic model of sporadic Alzheimer's disease (AD). Erythropoietin (EPO) possesses neuroprotective and memory-improving effects, which might be advantageous in treating different characteristics of AD. Nevertheless, the hematopoietic effect of EPO has hindered its application as a neuroprotective agent. Previous studies have shown that a new Epo derivative called carbamylated Erythropoietin-Fc (CEPO-Fc), yield noticeable neuroprotective effects without affecting hematopoiesis. In this study, the neuroprotective effects of CEPO-Fc on icv-STZ induced memory impairment and hippocampal apoptosis were examined. Adult male Wistar rats weighing 250−300 g were used. STZ was administered on days 1 and 3 (3 mg/kg in divided doses/icv), and CEPO-Fc was administered at the dose of 5000 IU/ip/daily during days 4–14. The animals were trained in Morris water maze during days 15–17, and the memory retention test was performed on the 18th day. Following behavioral studies, the animals were sacrificed and their hippocampi isolated to determine the amounts of cleaved caspase-3 (the landmark of apoptosis). The results showed that CEPO-Fc treatment at the dose of 5000 IU/kg/ip was able to prevent the learning and memory deficit induced by icv-STZ. Western blot analysis revealed that STZ prompted the cleavage of caspase-3 in the hippocampus while pretreatment with CEPO-Fc significantly reduced the cleavage of this protein. Collectively, our findings suggest that CEPO-Fc could restore STZ-induced learning and memory impairment as well as apoptosis in the hippocampal region in a rat model of sporadic AD induced by icv-STZ. [ABSTRACT FROM AUTHOR]