The role of HCN channels on the effects of T-type calcium channels and GABAA receptors in the absence epilepsy model of WAG/Rij rats.

In this study we used ivabradine (IVA), a hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blocker, to identify its effect on spike-wave discharges (SWDs); and aimed to determine the role of IVA on the effects of T-type calcium channel blocker NNC 55-0396, GABAA receptor agonist muscimol and antagonist bicuculline in male WAG/Rij rats. After tripolar electrodes for electrocorticogram (ECoG) recordings were placed on the WAG/Rij rats' skulls, 5, 10, and 20 mg/kg IVA were intraperitoneally administered for 7 consecutive days and ECoG recordings were obtained on days 0th, 3rd, 6th, and 7th for three hours before and after injections. While acute injection of 5, 10, and 20 mg/kg IVA did not affect the total number and the mean duration of SWDs, subacute administration (7 days) of IVA decreased the SWDs parameters 24 hours after the 7th injection. Interestingly, when IVA was administered again 24 hours after the 6th IVA injection, it increased the SWDs parameters. Western-blot analyses showed that HCN1 and HCN2 expressions decreased and HCN4 increased in the 5-month-old WAG/Rij rats compared to the 1-month-old WAG/Rij and 5-month-old native Wistar rats, while subacute IVA administration increased the levels of HCN1 and HCN2 channels, except HCN4. Subacute administration of IVA reduced the antiepileptic activity of NNC, while the proepileptic activity of muscimol and the antiepileptic activity of bicuculline were abolished. It might be suggested that subacute IVA administration reduces absence seizures by changing the HCN channel expressions in WAG/Rij rats, and this affects the T-type calcium channels and GABAA receptors.

Investigation of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in vitro inflammation model at molecular level.

In our study, we aimed to create an inflammation model in endothelial and macrophage cell lines and to examine the changes in the expression of hyperpolarization activated cyclic nucleotide gated (HCN) channels at the molecular level. HUVEC and RAW cell lines were used in our study. 1 µg/mL LPS was applied to the cells. Cell media were taken 6 h later. TNF-α, IL-1, IL-2, IL-4, IL-10 concentrations were measured by ELISA method. Cell media were cross-applied to cells for 24 h after LPS. HCN1/HCN2 protein levels were determined by Western-Blot method. HCN-1/HCN-2 gene expressions were determined by qRT-PCR method. In the inflammation model, a significant increase in TNF-α, IL-1, and IL-2 levels was observed in RAW cell media compared to the control. While no significant difference was observed in IL-4 level, a significant decrease was observed in IL-10 level. While a significant increase in TNF-α level was observed in HUVEC cell medium, no difference was observed in other cytokines. In our inflammation model, an 8.44-fold increase in HCN1 gene expression was observed in HUVEC cells compared to the control group. No significant change was observed in HCN2 gene expression. 6.71-fold increase in HCN1 gene expression was observed in RAW cells compared to the control. The change in HCN2 expression was not statistically significant. In the Western-Blot analysis, a statistically significant increase in HCN1 level was observed in the LPS group in HUVEC cells compared to the control; no significant increase in HCN2 level was observed. While a statistically significant increase in HCN1 level was observed in the LPS group in RAW cells compared to the control; no significant increase in HCN2 level was observed. In immunofluorescence examination, it was observed that the level of HCN1 and HCN2 proteins in the cell membrane of HUVEC and RAW cells increased in the LPS group compared to the control group. While HCN1 gene/protein levels were increased in RAW and HUVEC cells in the inflammation model, no significant change was observed in HCN2 gene/protein levels. Our data suggest that the HCN1 subtype is dominant in endothelium and macrophages and may play a critical role in inflammation.

GLP-1 agonist liraglutide improves ouabain-induced mania and depressive state via GSK-3ß pathway.

Bipolar disorder (BD) is a severe mental illness characterized by aberrant mood changes between hypomania and mania or mixed states and depression. Metabolic changes also accompany disease progression and cause significant morbidity. Symptomatic treatment options are available, but asymptomatic patients and poor drug responders are significant problems. Based on the most common pharmacological agent that is used in the treatment, lithium and its main mechanisms of action, oxidative stress, and glycogen synthase kinase-3ß (GSK-3ß) signaling are extensively investigated. However, knowledge about the effects of compounds that positively affect oxidative stress and GSK-3ß signaling, such as glucagon-like peptide-1 (GLP-1) mimetics, liraglutide, is still missing. Therefore, in this study, we aimed to investigate the effects of liraglutide on the ouabain-induced bipolar disease model in rats. After intracerebroventricular single dose ouabain administration, animals were treated with 100, 200, and 400 µg/kg liraglutide (s.c.) and valproic acid (200 mg/kg, i.p.) for 10 d. The locomotion and depressive states of animals were assessed by an open field, forced swimming test, and sucrose preference tests. Serum total antioxidant (TAS) and oxidant states (TOS) and glutathione, malonyl dialdehyde (MDA) levels in the brain tissue were determined. GSK-3ß phosphorylation was evaluated by western blotting. Our results demonstrated that liraglutide attenuated ouabain-induced hyperlocomotion and depressive state. Additionally, liraglutide prevented oxidative stress after ouabain administration. Decreased GSK-3ß phosphorylation due to the ouabain insult was alleviated by liraglutide treatment. These findings indicate that the manic and depressive-like behaviors are ameliorated by liraglutide, which exerted antioxidant action, possibly improving GSK-3ß phosphorylation.

Role of TRPV1 channels on glycogen synthase kinase-3ß and oxidative stress in ouabain-induced bipolar disease.

Bipolar disorder (BD) is a multifactorial chronic and refractory disease characterized by manic, depressive, and mixed mood episodes. Although epidemiological, and pathophysiological studies demonstrated a strong correlation between bipolar disorder and oxidative stress, precise etiology is still missing. Recent studies suggested the possible role of transient receptor potential channels (TRP) in the BD but, current knowledge is limited. Therefore, the current study investigates the possible role of TRPV1 in the ouabain-induced model of BD. The model was created with intracerebroventricular single dose ouabain (10-3 M) administration. Animals were treated with capsaicin, capsazepine, and lithium for seven days. Mania and depressive-like states were investigated with open-field, sucrose preference, and elevated plus maze tests. Oxidative stress was assessed by measuring total antioxidant and oxidant states, spectrophotometrically. The phosphorylation Glycogen synthase kinase-3ß (GSK-3ß) evaluated by western blotting. Our results demonstrated that capsaicin dose-dependently inhibited the ouabain-induced hyperlocomotion and depression. Although capsazepine exacerbated behavioral impairment, it did not show a significant effect on the antioxidant and oxidant states, and the effects of capsazepine on behaviors were abolished by combination with capsaicin. Additionally, capsaicin potently prevented the ouabain-induced decrease in GSK-3ß phosphorylation. In contrast, capsazepine potentiated ouabain-induced decrease in GSK-3ß phosphorylation and combination with capsaicin, suppressed the effect of capsazepine on GSK-3ß phosphorylation. The effects of TRPV1 activation on oxidative stress and mania-like behaviors in the ouabain-induced BD model might be regulated by GSK-3ß phosphorylation.

CIITA expression is regulated by histone deacetylase enzymes and has a role in α-synuclein pre-formed fibril-induced antigen presentation in murine microglial cell line.

AIM: Parkinson's disease (PD) is a chronic neurodegenerative disorder related with several genetic and epigenetic factors. In the context of epigenetic factors, histone acetylation is one of the most associated mechanisms with Parkinson's disease progression. This study investigates the effects of the increased histone acetylation on antigen presentation in microglial cells which were induced by pre-formed fibrils of α-synuclein (pFF α-synuclein). METHODS: Parkinson's disease model was created with pFF α-synuclein administration to the BV-2 microglial cells. BV-2 cells were co-treated with CUDC-907 and TMP-195 to increase histone acetylation in the presence of α-synuclein. Antigen representation was evaluated by determining expression levels of major histocompatibility complex-II (MHC-II) and class-II major histocompatibility complex (CIITA). RESULTS: Our results showed that pFF α-synuclein significantly increased MHC-II expression, and that effect was most severe at 6 h of administration of α-synuclein. Increasing histone acetylation via CUDC-907 and TMP-195 enhanced MHC-II levels expression, which was more severe in CUDC-907. Additionally, CIITA expression levels were significantly increased with pFF α-synuclein administration and intensified with the co-treatment of CUDC-907 and TMP-195. Furthermore, pFF α-synuclein caused a time-dependent increase in the IFN-gamma (IFN-É£) and interleukin-16(IL-16) levels, and that increase was potentiated with CUDC-907 and TMP-195. CONCLUSION: Changes in MHC-II and CIITA expression indicate that histone acetylation increases the antigen presentation properties of microglial cells after pFF α-synuclein or histone deacetylase inhibitor (HDACi) administration. Our results show that microglial antigen presentation might have an essential role in the pathology of Parkinson's disease, and α-synuclein likely to play a primary role in this mechanism.

Asiatic acid exerts an anti-psoriatic effect in the imiquimod-induced psoriasis model in mice.

Background: Psoriasis is a common skin disorder related to inflammation and immune response. However, many treatment modalities are present in the clinics, and drug conformity halts chronic treatment. Therefore, novel treatment options are still needed. In this study, the possible protective effect of asiatic acid is one of the active compounds present in Centella Asiatica, was investigated in the imiquimod-induced psoriasis murine model.Methods:Imiquimod (62.5 mg) was administered dorsal skin of the mice for 6 days. Animals were co-treated with low-dose (25 mg/kg, p.o.) and high-dose (100 mg/kg, p.o.) asiatic acid. The dorsal skin of the animals was daily scored for erythema, thickness, and scaling. At the end of the treatments, serum levels of IL-17A and IL-23 were determined by ELISA. Additionally, the dorsal skins of animals were histopathologically evaluated.Results: Asiatic acid (high-dose) prevented imiquimod-induced skin lesions and protected dermal integrity in addition decreasing mast cell infiltration due to the imiquimod. Furthermore, asiatic acid (high-dose) suppressed the imiquimod-induced increase in serum levels of IL-17A and IL-23.Conclusion: These results indicate that asiatic acid showed an anti-psoriatic effect in the imiquimod-induced psoriasis model via mediating IL-17A and IL-23 pathways. Because wound healing properties of asiatic acid are described, further investigations should be carried out to understand deeper mechanisms and possible use in dermatological pathologies such as psoriasis.

The beneficial effect of salubrinal on neuroinflammation and neuronal loss in intranigral LPS-induced hemi-Parkinson disease model in rats.

OBJECTIVE: Endoplasmic reticulum stress (ERS) and neuroinflammation are triggers for neurodegenerative disorders. Salubrinal is a selective inhibitor of protein phosphatase 1 (PP1) complex involving dephosphorylation of phosphorylated eukaryotic initiation factor-2α (eIF2α), the key crucial pathway in the ERS. Therefore, this study assessed the effects of inhibition of the ERS with salubrinal in the intranigral hemi-Parkinson disease (PD) model. MATERIALS AND METHODS: Animals were treated with salubrinal for one week after the PD model was created by intranigral lipopolysaccharide (LPS) administration. Apomorphine-induced rotation, rotarod, cylinder, and pole tests were performed to evaluate behavioral changes. Proinflammatory cytokines and the expression level of the dual specificity protein phosphatase 2 (DUSP2), PP1, and p-eIF2α were evaluated. Nigral expression of inducible nitric oxide synthase (iNOS), nuclear factor kappaB (Nf-κB), and cyclooxygenase (COX)-2 was determined. Finally, tyrosine hydroxylase and caspase-3/ caspase-9 expressions were assessed by immunohistochemistry. RESULTS: Salubrinal reduced the motor impairments and dopamine-related behavioral deficiencies caused by the LPS. Salubrinal attenuated the LPS-induced increased levels of interleukin (IL)-1ß, IL-6, tumor necrosis factor-α, and salubrinal rescued the loss of TH expression and dopamine levels and prevented the caspase-3/9 increase in the substantial nigra (SN). LPS potently increased iNOS, Nf-κB, and COX-2 expression, but this effect was reduced after salubrinal treatment. Additionally, salubrinal attenuated the LPS-induced PP1 and DUSP2 increase. CONCLUSION: Our results reveal that salubrinal is attenuating several inflammatory mediators and thereby decreased the inflammatory effects of LPS in the neurons of the SN. Together this results in increased cellular survival and maintained integrity of SN. Taken together our data show the beneficial effects of inhibition of ERS to restrict neuroinflammatory progression and neuronal loss in a PD model.

Cannabinoid receptors modulate LPS-induced increase of class-II transactivator expression levels in a microglial cell line.

Microglial antigen generation (MAG) is an essential process in regulating disease states and homeostasis of the central nervous system. MAG is considered as responsible autoimmune mechanism in neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's diseases. Neuroprotective and regulator effects of cannabinoid receptors on these disease states and modulation with pharmacological agents are urgent subjects in recent decades. Although different aspects of microglial immune response have been investigated, specific effects of these receptor subtypes in the MAG are still unclear. Therefore, in the current study, we have investigated the effects of CB1 and CB2 receptors on antigen generation by investigating MHC-II and its master regulator CIITA by specific cannabinoid agents (ACEA, AM-251, CP 55,940, and SR144528) in the LPS-induced BV-2 cells. Additionally, the effects of drug treatments on inflammatory status were measured by determining IL-1ß, IL-6, and TNF-α levels. LPS-induced increase in MHC-II and CIITA expression was inhibited by specific CB1 agonist, ACEA, and nonselective cannabinoid agonist CP 55,940. A combination with specific CB1 antagonist AM-251 prevented these inhibitory effects of ACEA and CP 55,940 on both MHC-II and CIITA expression. Although specific CB2 antagonist, SR144528, also prevented the inhibitory effect of CP 55,940 on MHC-II, it did not affect CIITA expression. LPS-induced IL-1ß, IL-6, and TNF-α increase both attenuated with CP 55,940 and ACEA treatments. Although both selective cannabinoid antagonists inhibited this effect, preventive effects were more dominant on CB1 receptors. Our results demonstrated that CB1 receptors majorly mediates LPS-induced MHC-II and its regulator CIITA expression in microglial cells.

Idebenone Ameliorates Rotenone-Induced Parkinson's Disease in Rats Through Decreasing Lipid Peroxidation.

Oxidative stress is considered one of the mechanisms responsible for neurodegenerative diseases, especially for Parkinson's disease. Since oxidative stress causes pathological changes in neuronal structures antioxidant compounds gained significant attention the last decades. Although several antioxidant compounds showed neuroprotective actions in Parkinson's disease models, only a few of them demonstrated protective effects against loss of striatal dopaminergic neurons. Idebenone is an analog of the well-known antioxidant compound coenzyme Q10 (CoQ10). Clinical safety of idebenone is well described, and due to its high antioxidant capacity currently used to treat Freidrich's ataxia and Alzheimer's disease. Like Parkinson's disease, these diseases are characterized by oxidative stress and impaired mitochondrial balance in neurons. However, knowledge about the effects of idebenone on Parkinson's disease is limited. Therefore, in this study we aimed to investigate and delineate the possible effects of idebenone in rotenone-induced Parkinson's disease models. Idebenone (200 mg/kg, p.o.) inhibited the decrease of striatal expression of NAD(P)H dehydrogenase[quinone]-1, which is an essential element for mitochondrial respiration. Idebenone decreased the striatal levels of the lipid peroxidation products and increased the expression of glutathione peroxidase-4 (GPx-4), which is primarily known for lipid peroxidation and ferroptosis. Furthermore, idebenone mitigated motor impairment and increased tyrosine hydroxylase-positive neuron survival. Together our results thus indicate that that idebenone has protective effects against a rotenone insult with pleiotropic actions on the cellular oxidative enzymes and lipid peroxidation.

The receptor for advanced glycation end product (RAGE) pathway in COVID-19.

INTRODUCTION: Coronavirus disease-2019 (COVID-19) with lung involvement frequently causes morbidity and mortality. Advanced age appears to be the most important risk factor. The receptor for advanced glycation end-product (RAGE) pathway is considered to play important roles in the physiological aging and pathogenesis of lung diseases. This study aimed to investigate the possible relationship between COVID-19 and RAGE pathway. MATERIALS AND METHODS: This study included 23 asymptomatic patients and 35 patients with lung involvement who were diagnosed with COVID-19 as well as 22 healthy volunteers. Lung involvement was determined using computed tomography. Serum soluble-RAGE (sRAGE) levels were determined using enzyme-linked immunosorbent assay. RESULTS: The sRAGE levels were significantly higher in the asymptomatic group than in the control group. Age, fibrinogen, C-reactive protein, and ferritin levels were higher and the sRAGE level was lower in the patients with lung involvement than in the asymptomatic patients. CONCLUSIONS: In this study, patients with high sRAGE levels were younger and had asymptomatic COVID-19. Patients with low sRAGE levels were elderly patients with lung involvement, which indicates that the RAGE pathway plays an important role in the aggravation of COVID-19.

Agomelatine confers neuroprotection against cisplatin-induced hippocampal neurotoxicity.

Neurotoxicity caused by cisplatin is a major obstacle during chemotherapy. Oxidative stress and inflammation are considered the primary mechanism behind neuronal damage which affects the continuing chemotherapy regimen. Agomelatine was recently described as a neuroprotective compound against toxic insults in the nervous systems. It is an analog of the well-known antioxidant and anti-inflammatory compound melatonin and currently used for depression and sleep disturbances. In the current study, we investigated the possible neuroprotective role of agomelatine against cisplatin-induced oxidative, inflammatory, and behavioral alterations in male rats. Our results show that agomelatine prevented cisplatin-induced neurotoxicity in the HT-22 mouse hippocampal neuronal cell line. Additionally, agomelatine treatment inhibited cisplatin-induced behavioral deficits and neuronal integrity in vivo. For the evaluation of the effect of agomelatine on oxidative stress and inflammation, GSH, MDA, TNF, and IL-6 levels were analyzed in HT-22 cells and hippocampal tissues. Agomelatine significantly attenuated oxidative stress and inflammation due to the cisplatin insult in vitro and in vivo. Also, agomelatine treatment ameliorated the neuronal pathology in the hippocampus, which is strongly related to cognition and memory. Taken together, our results indicate that in males, the neuroprotective effect of agomelatine is mediated through its antioxidant and anti-inflammatory actions abrogating functional deficits.

Tofacitinib enhances remyelination and improves myelin integrity in cuprizone-induced mice.

AIM: Demyelination and subsequent remyelination are well-known mechanisms in multiple sclerosis (MS) pathology. Current research mainly focused on preventing demyelination or regulating the peripheral immune system to protect further damage to the central nervous system. However, information about another essential mechanism, remyelination, and its balance of the immune response within the central nervous system's boundaries is still limited. MATERIALS AND METHODS: In this study, we tried to demonstrate the effect of the recently introduced Janus kinase (JAK)-signal transducer and activator of transcription (STAT) inhibitor, tofacitinib, on remyelination.Demyelination was induced by 6-week cuprizone administration, followed by 2-week tofacitinib (10, 30, and 100 mg/kg) treatment. RESULTS: At the functional level, tofacitinib improved cuprizone-induced decline in motor coordination and muscle strength, which were assessed by rotarod and hanging wire tests. Tofacitinib also showed anti-inflammatory effect by alleviating the cuprizone-induced increase in the central levels of interferon-γ (IFN-γ), interleukin (IL)-6, IL-1ß, and tumor necrosis alpha (TNF-α). Furthermore, tofacitinib also suppressed the cuprizone-induced increase in matrix metalloproteinases (MMP)-9 and MMP-2 levels. Additionally, cuprizone-induced loss of myelin integrity and myelin basic protein expression was inhibited by tofacitinib. At the molecular level, we also assessed phosphorylation of STAT-3 and STAT-5, and our data indicates tofacitinib suppressed cuprizone-induced phosphorylation in those proteins. CONCLUSION: Our study highlights JAK/STAT inhibition provides beneficial effects on remyelination via inhibition of inflammatory cascade.

SAHA attenuates rotenone-induced toxicity in primary microglia and HT-22 cells.

Rotenone is an industrial and environmental toxicant that has been strongly associated with neurodegeneration. It is clear that rotenone induces inflammatory and oxidative stress; however, information on the role of histone acetylation in neurotoxicity is limited. Epigenetic alterations, neuroinflammation, and oxidative stress play a role in the progression of neurodegeneration and can be caused by exposure to environmental chemicals, such as rotenone. Histone modifications, such as methylation and acetylation, play an important role in mediating epigenetic changes. Therefore, we here investigated the effects of histone acetylation on rotenone-induced inflammation and oxidative stress in both primary mouse microglia and hippocampal HT-22 cells using the pan-histone deacetylase (HDAC) inhibitor, suberoylanilide hydroxamic acid (SAHA). Our results showed that SAHA suppressed the inflammatory response by decreasing nuclear factor kappa B and inducible nitric oxide synthase expression. Additionally, SAHA inhibited the rotenone-induced elevation of interleukin 6 and tumor necrosis factor α levels in both cell lines. Furthermore, SAHA improved the rotenone-induced antioxidant status by mitigating the decrease in cellular glutathione levels. Additionally, SAHA prevented the rotenone-induced increase in the HDAC activity in microglial and hippocampal HT-22 cells. Together, our results showed that SAHA reduced rotenone-induced inflammatory and oxidative stress, suggesting a role for histone deacetylation in environmental-related neurotoxicity.

Alterations in the matrix metalloproteinase-3 promoter methylation after common chemotherapeutics: in vitro study of paclitaxel, cisplatin and methotrexate in the MCF-7 and SH-SY5Y cell lines.

Cancer treatment is a complex process due to the several encountered obstacles during therapy, such as metastasis, angiogenesis, and drug resistance. The methylation status of elements that are thought to play crucial roles in these mechanisms is considered valuable targets. Matrix metalloproteinase-3 (MMP-3), one of the possible targets, is a well-known endopeptidase and secreted by several types of cancer cells. Paclitaxel, cisplatin, and methotrexate are frequently used for several malignancies, individually or in combination. Therefore, the aims of this study is that demonstration of possible effects of different doses of single or jointly application of these agents with maintaining their antiproliferative activity in clinically relevant cell lines, as well as revealing epigenetic results of this pharmacological alteration with exploring promoter methylation status of the MMP-3 gene. Cell viability was determined with Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay. Further methylation-specific PCR (MSP) experiments for determining the promoter methylation status of MMP-3 were performed according to the obtained IC50 values of the drug treatments. The MMP-3 promoter methylation status was analayzed with MSP and determined with agarose gel electrophoresis. As a result, methotrexate and paclitaxel treatment significantly methylated the MMP-3 promoter; however, cisplatin caused MMP-3 promoter unmethylation in MCF-7 and SH-SY5Y cells. Our study indicates that decreasing the dose of clinically prevalent chemotherapeutic agents while maintaining the same tumor-killing potency might be a rational strategy for treatment. In addition to avoiding adverse effects of these compounds, decreasing treatment doses will bring substantial benefits for patient life-quality.

The assessment of the serum levels of TWEAK and prostaglandin F2α in COVID ­ 19

Background/aim: It is claimed that aberrant immune response has a more important role than the cytopathic effect of the virus in the morbidity and mortality of the coronavirus disease 2019 (COVID-19). We aimed to investigate the possible roles of tumor necrosis factor-like weak inducer of apoptosis (TWEAK)/Fn14 pathway and leukotrienes (LT) in uncontrolled immune response that occurs in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Materials and methods: This study included 25 asymptomatic patients and 35 patients with lung involvement who were diagnosed with COVID-19 as well as 22 healthy volunteers. Lung involvement was determined using computed-tomography. Serum TWEAK, LTE4, and prostaglandin F2α (PGF2α) levels were determined. Results: Compared with the healthy control group, TWEAK, LTE4, and PGF2α levels were higher in the group of SARS-CoV-2 infection without lung involvement. In the group of SARS-CoV-2 infection with lung involvement, age, fibrinogen, sedimentation, C-reactive protein and ferritin, TWEAK, LTE4, and PGF2α levels were higher, and lymphocyte levels were lower compared with the asymptomatic group. Conclusions: In the study, TWEAK and LTE4 levels increased in cases with COVID-19. These results support that TWEAK/Fn14 pathway and LT may involved in the pathology of aberrant immune response against SARS-CoV-2. Inhibition of each of these pathways may be a potential target in the treatment of COVID-19.

Atorvastatin reduces alloxan-induced impairment of aversive stimulus memory in mice.

Background: An association between dysregulated glucose levels in patients with diabetes mellitus and detrimental effects on the central nervous system, particularly in Alzheimer disease, has been recognized. Atorvastatin treatment has improved memory and cognition in some patients with diabetes mellitus and Alzheimer disease. Objectives: To determine possible neuroprotective effects of atorvastatin on memory and cognition by measuring changes in an adverse stimulus avoidance learning deficit induced by alloxan in a murine model of diabetes mellitus and impaired memory and cognition. Methods: We administered 150 mg/kg and 100 mg/kg alloxan in saline (intraperitoneally, i.p.) at a 48 h interval to produce a model of diabetes mellitus in male BALB/c mice. An oral glucose tolerance test (OGTT) was used to assess blood glucose regulation. After demonstrating hyperglycemia in mice (n = 7 per group) we administered vehicle (saline, i.p.), atorvastatin (10 mg/kg, i.p.), or liraglutide (200 µg/kg, i.p.) for 28 d except for those in a negative control group, which were given saline instead of alloxan, and a group administered atorvastatin alone, which were given saline instead of alloxan followed by atorvastatin (10 mg/kg, i.p.) for 28 d. Locomotor activity was measured 24 h after the final drug treatments, and subsequently their learned behavioral response to an adverse electrical stimulus to their plantar paw surface in a dark compartment was measured using a passive avoidance apparatus (Ugo Basile) in a model of impaired memory and cognition associated with Alzheimer disease. To determine any deficit in their learned avoidance of the adverse stimulus, we measured the initial latency or time mice spent in an illuminated white compartment before entering the dark compartment in the learning trial, and on the day after learning to avoid the adverse stimulus, the retention period latency in the light compartment and time spent in the dark compartment. Results: Atorvastatin alone produced no significant change in blood glucose levels (F4,10 = 0.80, P = 0.55) within 2 h. Liraglutide decreased blood glucose levels after 0.5 h (F4,10 = 11.7, P < 0.001). We found no significant change in locomotor activity in any group. In mice with alloxan-induced diabetes, atorvastatin significantly attenuated the decreased avoidance associated with the diabetes (F4,30 = 38.0, P = 0.02) and liraglutide also significantly attenuated the decreased avoidance (F4,30 = 38.0, P < 0.001). Atorvastatin alone had no significant effect on the adversive learned response compared with vehicle treatment (F4,30 = 38.0, P > 0.05). Atorvastatin significantly decreased the time mice with alloxan-induced diabetes spent in the dark compartment compared with mice in the diabetes group without atorvastatin treatment (F4,30 = 53.9, P = 0.046). Liraglutide also significantly reduced the time mice with alloxan-induced diabetes spent in the dark compartment compared with vehicle-treated mice with alloxan-induced diabetes (F4,30 = 53.9, P < 0.001). Atorvastatin treatment alone had no significant effect on the time mice spent in dark compartment compared with the control group (F4,30 = 53.9, P > 0.05). Conclusion: Atorvastatin significantly attenuated the adverse stimulus avoidance learning deficit in the alloxan-induced murine model of diabetes suggesting decreased impairment of memory and cognition.

Effects of Suberoylanilide Hydroxamic Acid (SAHA) on the Inflammatory Response in Lipopolysaccharide-Induced N9 Microglial Cells.

INTRODUCTION: Epigenetics has shown promising results for understanding the different behaviors of microglia under the context of neuroinflammation. However, to our knowledge, the results of this complex mechanism with novel pharmacological agents such as histone deacetylase inhibitors (HDACis) are still missing. In this study, we aimed to investigate the effects of suberoylanilide hydroxamic acid (SAHA), a pan-HDACi, on the lipopolysaccharide (LPS)-induced neuroinflammation model in the N9 microglial cells. METHODS: Microglial cells were treated with SAHA (0.25, 0.5, 1.0, 1.25, 1.5 µM) and LPS (100 ng/mL) for 24 hours. Then, levels of the pro/anti-inflammatory cytokines interleukin-1 beta (IL-1ß), IL-6, tumor necrosis factor alpha (TNF-α), and IL-10 were determined by the enzyme-linked immunosorbent assay. The total cellular HDAC activity was determined by colorimetric analysis. Additionally, the expression levels of nuclear factor kappa-B (NF-κB) were quantified via western blotting. RESULTS: SAHA (1.0 and 1.25 µM) attenuated the LPS-induced inflammatory response of microglial cells via decreasing NF-κB expression and pro-inflammatory cytokines (IL-1ß, IL-6, TNF-α) in the N9 microglial cells. Moreover, SAHA treatment improved IL-10 levels and prevented the LPS-induced increase in the HDAC activity in the microglial cells. CONCLUSION: Our results suggest SAHA attenuates the LPS-induced inflammatory response in the N9 microglial cells, and regulation of histone acetylation with HDACis might be a rational approach for the treatment of neuroinflammation.

Cannabinoid receptor-1 has an effect on CD200 under rotenone and alpha-synuclein induced stress.

Decades after identifying cannabinoids and their beneficial effects on Parkinson's disease (PD), many gaps are still missing. Although, CB2-dependent actions have been shown as underlying positive effects of cannabinoid treatment, in recent years, another receptor of cannabinoids, CB1, emerged as a valuable player in cannabinoid-induced neuroprotection. Remarkably, the effects of CB1 are mainly related to immune cells in the CNS, microglia, and astrocytes. However, oxidative stress, α-syn accumulation, and immune disbalance are essential aspects of both neurons and glial cells. Therefore, in this study, we investigated the effects of the CB1 on both α-syn and rotenone-treated SH-SY5Y and C8-D1A cells. ACEA and AM-251 were used as CB1 agonists and antagonists. Cell viability, IL-1ß, IL-6, TNF-α levels, and CD200 expressions were determined in culture mediums. Our results demonstrated that preformed fibril form (pFF) of α-syn did not cause any significant change in SH-SY5Y cells compared to C8-D1A cells. Rotenone significantly increased the expression of IL-1ß, IL-6, and TNF-α levels in both cells. pFF α-syn and rotenone treatment caused a decrease in CD200 expression. Surprisingly both ACEA and AM-251 alleviated rotenone-induced increase in cytokine levels in both cell lines. Although ACEA prevented pFF α-syn induced increase in cytokine levels and decrease in CD200 expression in C8-D1A cells, AM-251 failed to affect CD200 expression levels. Additionally, ACEA + AM-251 abolished the protective effects of both ACEA and AM-251 against rotenone and α-syn insults in both cell lines. The current study suggests that cannabinoid receptor agonism alleviates rotenone and α-syn-dependent inflammation in neurons and astrocytes.

Proconvulsant effect of trans-cinnamaldehyde in pentylenetetrazole-induced kindling model of epilepsy: The role of TRPA1 channels.

The transient receptor potential ankyrin 1 (TRPA1), a member of the TRP superfamily, is widely distributed in the central nervous system (CNS) and plays an important role in pain and inflammation. However, no data has been reported regarding the effects of TRPA1 on epileptic seizures. Thus, this study was designed to investigate the sub-chronic effect of trans-cinnamaldehyde (TCA), an agonist of TRPA1, in pentylenetetrazole (PTZ) induced kindling model via electrocorticography (ECoG). Furthermore, the expressions of cAMP response element binding protein (CREB), brain-derived neurotrophic factor (BDNF), and NMDA receptor subunit NR2B were measured using Western blotting. Rats were kindled by intraperitoneal (i.p.) PTZ (35 mg/kg) injections. After electrode implantation and healing period, 10 and 30 mg/kg TCA was given i.p. for 14 consecutive days. On the next day, ECoG recordings were obtained after the injection of PTZ (35 mg/kg, i.p.), and twenty-four hours later, rats were decapitated for molecular analyses. TCA, at a dose of 30 mg/kg, decreased the first myoclonic jerk latency and increased seizure duration and total spike activity. Additionally, both doses of TCA enhanced CREB, BDNF, and NR2B expressions, which were increased by the kindling. The evidence from this study suggests that long term activation of TRPA1 channels causes an exacerbated seizure activity. Moreover, PTZ-induced increases in CREB, BDNF, and NR2B levels were enhanced by the repeated administrations of TCA.

The neuroprotective action of lenalidomide on rotenone model of Parkinson's Disease: Neurotrophic and supportive actions in the substantia nigra pars compacta.

Lenalidomide is a centrally active thalidomide analog that has potent anti-inflammatory and antiangiogenic activities. Currently, it is primarily used in the treatment of multiple myeloma and myelodysplastic syndromes. However, recent studies have revealed in addition to neuroprotection and neuromodulation of lenalidomide. Because of this combination of inflammation and neuro-immunogenic properties, lenalidomide is considered as a high potential compound for the treatment of neurodegenerative diseases. Despite intensive research during the last decade, the role of neurotrophic elements in the effect of lenalidomide is still not well understood. Therefore, in the current study, the effects of lenalidomide on neurodegeneration were investigated in a rotenone model of Parkinson's disease (PD) rat model. The PD rat model was generated by rotenone injection into the substantia nigra pars compacta (SNpc). After validation of the PD model, the rats were treated with lenalidomide (100 mg/kg) for 28 days. Our data shows that lenalidomide alleviated rotenone-induced motor impairments and deficits in dopamine-related behaviors and resulted in increased levels of tumor necrosis factor-α and calcium-binding protein B in the SNpc. Moreover, chronic lenalidomide treatment resulted increase in transforming growth factor immunoreactivity and brain derived neurotrophic factor expression in the SNPc. In addition, chronic treatment mitigated tyrosine hydroxylase expression prevented the rotenone-induced decrease in dopamine levels, and consequently a decrease in caspase-3/9 immunoreactivity. This thus shows that chronic lenalidomide treatment improves neuronal survival. Together with our data demonstrate that lenalidomide, in addition to its anti-inflammatory and immunomodulatory actions, is also capable of increasing neurotrophic factors in the SNpc, thereby preventing rotenone-induced motor impairments.