CNS & Neurological Disorders - Drug Targets (Formerly Current Drug Targets - CNS & Neurological Disorders) - Volume 17, Issue 7, 2018

Background: The evidence based supports that multifactorial and complex immune interactions play a role in autism spectrum disorders (ASD), but contradictory findings are also reported. Objective: The aim of this selective review was to identify trends in the research literature on this topic, focusing on immunology and other aberrations with respect to the different ASD subtypes. Methods: This selective review is based on original and review articles written in English and identified in literature searches of PubMed. Results: Several studies have found that the risk of ASD is greater among children whose mothers suffered from autoimmune diseases while pregnant. Moreover, individuals with ASD show increased levels of antibodies that are specific for several specific proteins. Studies also show that mothers of children with ASD have antibodies against fetal brain proteins. There are also reports on the associations between increased levels of proinflammatory cytokines and ASD. Finally, infections in mothers during pregnancy are linked to an increased risk of ASD. Conclusion: We propose that the large inconsistencies in findings among studies in the field are due to differences in subdiagnoses among the included children with ASD. Well-phenotyped ASD samples are needed to understand the biological and immunological mechanisms underpinning ASD and its subdiagnoses. Future research should apply new strategies to scrutinize the link between ASD and changes in immune responsivity. Important new research avenues are to investigate the associations (a) between different ASD phenotypes and aberrations in (auto)immune pathways and (b) between reduced natural regulatory autoimmune responses during pregnancy, which are in turn associated with increased oxidative and nitrosative stress in maternal blood and putative detrimental effects in the offspring.

Background & Objective: Multiple sclerosis is an autoimmune demyelinating disease of the human central nervous system with still unknown etiology. Infiltration, accumulation and activation of autoreactive T cells, macrophages and other inflammatory immune cells in the CNS are the crucial steps in MS neuropathogenesis and development. Chemokines and their receptors play the main role in the attraction of the pathogenic cells into the CNS in MS. Specific chemokines and chemokine receptors are up-regulated in the actively demyelinating lesions and cerebrospinal fluid of MS patients. Many medical studies investigated how changes in levels or activities of chemokines and their receptors are implicated in leukocyte migration into CNS and consequently causing MS. These chemokines and their receptors are under intense focus to introduce new therapeutic strategies for MS. Conclusion: The aim of this review is to summarize previous findings on the relationship between chemokines network and MS development. Furthermore, opportunities and challenges in the chemokine system intervention as a potential therapeutic target for the treatment of MS will be outlined.

Background: Aphasia is a common complication after stroke, and traditional speech and language therapy (SLT) has a limited effect on post-stroke aphasia (PSA). While there has been an increasing number of controlled clinical trials on the efficacy of drugs in the treatment of PSA, there have been very few systematic reviews on the efficacy and safety of pharmacological treatments in people with PSA. Objective: To evaluate the efficacy and safety of pharmacological interventions for PSA. Methods: The Cochrane Central Register of Controlled Trials (CENTRA), PubMed, Embase, Chinese Journal Full-text Database (CJFD), China Biology Medicine disc (CBMdisc), Wanfang Data and VIP Information System were searched for randomized controlled trials about pharmacological treatments for PSA. Literature screening using the inclusion and exclusion criteria, data extraction and methodological quality assessment of the included studies were completed by two independent reviewers. Methodological quality was considered high for modified Jadad quality scale scores of 4 to 7. RevMan 5.3 software was used to conduct a meta-analysis of high-quality studies. Results: Fifteen studies (578 participants) satisfied the eligibility criteria for this systematic review. Five trials (277 participants) assessed donepezil, four studies (124 participants) assessed memantine, three studies (72 participants) assessed bromocriptine, one trial (45 patients) evaluated galantamine, one study (21 patients) evaluated amphetamine, and one trial (39 patients) evaluated levodopa. The systematic review showed that donepezil achieved remarkable results in terms of the aphasia quotient (AQ) (SMD 0.82, 95% CI 0.48-1.17, P < 0.00001), repetition ability (SMD 0. 81, 95% CI 0.57-1.06, P < 0.00001), naming ability (SMD 0.56, 95% CI 0.29-0. 84, P < 0.00001), auditory comprehension (SMD 0.85, 95% CI 0.58-1. 13, P< 0.00001) and oral expression (SMD 0.90, 95% CI 0.54-1.26, P < 0.00001). Memantine showed no pronounced improvement in auditory comprehension (SMD 0.35, 95% CI -0.05-0.74, P = 0.09) but did improve the AQ (SMD 0.57, 95% CI 0.09-1.06, P = 0. 02), naming ability (SMD 0.81, 95% CI 0.38-1.25, P = 0.0002), spontaneous speech (SMD 0.76, 95% CI 0. 39- 1.13, P < 0.0001), and repetition ability (SMD 0.37, 95% CI 0.01-0.73, P = 0.04). Bromocriptine showed pronounced improvement in naming ability (SMD -0.20, 95% CI- 0.67-0.26, P = 0.39), verbal fluency (SMD 0.02, 95% CI 0.53-0.56, P = 0.95), and repetition ability (SMD 0.29, 95% CI -0.23-0. 81, P = 0.28). There is limited and inconclusive evidence for galantamine, amphetamine and levodopa. Conclusion: Current evidence suggests that drugs, such as donepezil and memantine, can improve the prognosis of PSA. Donepezil has a significant effect in improving the ability of auditory comprehension, naming, repetition and oral expression. Memantine has a significant effect in improving the ability of naming, spontaneous speech and repetition. Bromocriptine showed no significant improvements in the treatment of aphasia after stroke. Data regarding galantamine, amphetamine and levodopa in the treatment of aphasia after stroke are limited and inconclusive.

Background: Pridopidine, a compound in clinical trials for Huntington's disease treatment, was originally synthesized as a dopamine D2 receptor (D2R) ligand, but later found to possess higher affinity for the sigma-1 receptor (S1R). However, the putative contributions of D2R and S1R to the behavioral profile of acutely administered pridopidine have not been investigated. Objective: The present study sought to compare the effects of acute pridopidine on wild-type vs. D2R and S1R knockout mice, at high (60 mg/kg) and low (6 mg/kg) doses. Method: Pridopidine effects on basal and phencyclidine-induced locomotor activity was measured in the open field test. Additionally, the actions of pridopidine on prepulse inhibition was measured in animals treated with saline or phencyclidine. Results: Whereas inhibition of spontaneous and phencyclidine-induced locomotion was readily observed at 60 mg/kg pridopidine, neither locomotor stimulation in habituated mice, nor any effects on prepulse inhibition were detected upon pridopidine treatment. Surprisingly, inhibition of spontaneous locomotion was unaffected by both D2R and S1R deletion. Conclusion: The present results suggest the involvement of additional targets, besides D2R and S1R, in mediating locomotor inhibition by pridopidine.

Background & Objective: The adolescent brain has a higher vulnerability to alcoholinduced neurotoxicity, compared to adult's brain. Most studies have investigated the effect of ethanol consumption on the body, however, methanol consumption, which peaked in the last years, is still poorly explored. Method: In this study, we investigated the effects of methanol neurotoxicity on memory function and pathological outcomes in the hippocampus of adolescent rats and examined the efficacy of Light- Emitting Diode (LED) therapy. Methanol induced neurotoxic rats showed a significant decrease in the latency period, in comparison to controls, which was significantly improved in LED treated rats at 7, 14 and 28 days, indicating recovery of memory function. In addition, methanol neurotoxicity in hippocampus caused a significant increase in cell death (caspase3+ cells) and cell edema at 7 and 28 days, which were significantly decreased by LED therapy. Furthermore, the number of glial fibrillary acid protein astrocytes was significantly lower in methanol rats, compared to controls, whereas LED treatment caused their significant increase. Finally, methanol neurotoxicity caused a significant decrease in the number of brain-derived neurotrophic factor (BDNF+) cells, but also circulating serum BDNF, at 7 and 28 days, compared to controls, which were significantly increased by LED therapy. Importantly, LED significantly increased the number of Ki-67+ cells and BDNF levels in the serum and hypothalamus in control-LED rats, compared to controls without LED therapy. Conclusion: In conclusion, chronic methanol administration caused severe memory impairments and several pathological outcomes in the hippocampus of adolescent rats which were improved by LED therapy.

Background: Radiation therapy is widely used for the treatment of pituitary adenomas. Unfortunately, it might raise the risk of ischemic stroke, with neuroinflammation being a major pathological process. Astrocytes are the most abundant cell type in the central nervous system and have been reported for playing important roles in ischemic stroke. Objective: Here we studied how γ-radiation would introduce astrocytes into a detrimental state for neuroinflammation and provide new theory evidence and target for the clinical management of inflammation- related neural damage after radiation-induced ischemic stroke. Method: HA-1800 cells were treated with γ-radiation and then the protein and mRNA levels of Connexin (Cx)-43 were evaluated by western and q-PCR. The culture supernatant was collected and the concentrations of the inflammatory factors were determined by ELISA. MiRNA complementary to Cx-43 was designed through the online tools. Results: Cx-43 is upregulated in the treatment of γ-radiation in astrocytes and γ-radiation introduced the detrimental function of astrocytes: cell viability was reduced while the apoptotic cells were increased. Inflammatory factors like tumor necrosis factor alpha, interferon gamma, interleukin-6, interleukin 1-beta were dramatically up-regulated by the irradiation. MiR-374a rescued irradiation induced Cx-43 up-regulation of astrocytes and eliminated detrimental function triggered by γ-radiation. Conclusion: Cx-43 expression level may play an important role in the inflammation-related neural damage after irradiation-induced ischemic stroke.

Background & Objective: Notoginsenoside R1 (NGR1) is one of the main effective components of Panax notoginseng. Method: Primary cortical neurons were harvested from neonatal rats and cultured to analyze the role of NGR1 in neuronal growth and the effects of NGR1 on the Wnt/β-catenin signaling pathway. Following treatment with NGR1, immunocytochemistry was used to detect expression of Tuj1 and MAP2, and RT-qPCR was used to measure mRNA levels of key factors in the Wnt signaling pathway. Results: Results showed that NGR1 promotes growth of cultured neurons and significantly upregulates mRNA levels of β-catenin, Dishevelled, and Frizzled. To further confirm whether NGR1 promoted cortical neuron growth via the Wnt/β-catenin signaling pathway, we knocked down β- catenin mRNA by siRNA interference; following NGR1 treatment of β-catenin-knockdown neurons, β-catenin mRNA levels increased significantly. Conclusion: In conclusion, these results demonstrate that NGR1 promotes growth of cultured cortical neurons from the neonatal rat, possibly via the Wnt/β-catenin signaling pathway.

Background: Glioblastoma multiforme (GBM) is the most aggressive and malignant primary brain tumor characterized by rapid growth and extensive infiltration to neighboring normal brain parenchyma, which contribute to tumor recurrence and poor prognosis. Myricetin is a natural flavonoid with potent anti-oxidant, anti-inflammatory and anti-cancer activities, which may serve as a potential and harmless agent for GBM treatment. Methods: To investigate the anti-glioblastoma effects of myricetin, GBM cells were treated with myricetin alone or in combination with temozolomide. Its effects on GBM cell motility and cytoskeletal structures including lamellipodia, focal adhesions and membrane ruffles were also evaluated. Results: We showed that myricetin alone inhibited glioblastoma U-87 MG cell proliferation, migration and invasion, whereas combination of myricetin and temozolomide did not exhibit any synergistic effect. The inhibitory effect on GBM cell proliferation is independent of PTEN status. Moreover, myricetin showed less cytotoxicity to normal astrocytes than GBM cells. Formation of lamellipodia, focal adhesions, membrane ruffles and vasculogenic mimicry were blocked by myricetin, and phosphorylation of ROCK2, paxillin and cortactin was suppressed. In addition, myricetin could inhibit PI3K/Akt and JNK signaling, and bind to a series of kinases and scaffold proteins including PI3K catalytic isoforms (p110α, p110β and p110δ), PDK1, JNK, c-Jun, ROCK2, paxillin, vinculin and VEcadherin. Conclusions: In conclusion, myricetin is a multi-targeted drug that has potent anti-migratory and antiinvasive effects on GBM cells, and suppresses formation of lamellipodia and focal adhesions, suggesting that it may serve as an alternative option for GBM treatment.