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In the last decade, there has been a great increase in methamphetamine hydrochloride (METH) abuse by pregnant women that exposes fetus and human offspring to a wide variety of developmental impairments that may be the underlying causes of future psychosocial issues. Herein, we investigated whether prenatal METH exposure with different doses (2 and 5 mg/kg) could influence neuronal cell death and antioxidant level in the different brain regions of adult male and female offspring. Adult male and female Wistar rats prenatally exposed to METH (2 or 5 mg/kg) and/or saline was used in this study. At week 12, adult rats' offspring were decapitated to collect different brain region tissues including amygdala (AMY) and prefrontal cortices (PFC). Western blot analysis was performed to evaluate the apoptosis- and autophagy-related markers, and enzymatic assay was used to measure the level of catalase and also reduced glutathione (GSH). Our results showed that METH exposure during pregnancy increased the level of apoptosis (BAX/Bcl-2 and Caspase-3) and autophagy (Beclin-1 and LC3II/LC3I) in the PFC and AMY areas of both male and female offspring's brain. Also, we found an elevation in the GSH content of all both mentioned brain areas and catalase activity of PFC in the offspring's brain. These changes were more significant in female offspring. Being prenatally exposed to METH increased cell death at least partly via apoptosis and autophagy in AMY and PFC of male and female offspring's brain, while the antioxidant system tried to protect cells in these regions., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Abnormal and sometimes severe behavioral and molecular symptoms are usually observed in epileptic humans and animals. To address this issue, we examined the behavioral and molecular aspects of seizure evoked by pilocarpine. Autophagy can promote both cell survival and death, but there are controversial reports about the neuroprotective or neurodegenerative effects of autophagy in seizure. Cannabidiol has anticonvulsant properties in some animal models when used as a pretreatment. In this study, we investigated alteration of seizure scores, autophagy pathway proteins, and antioxidant status in hippocampal cells during the chronic phase of pilocarpine-induced epilepsy after treatment with cannabidiol. Cannabidiol (100 ng, intracerebroventricular injection) delayed the chronic phase of epilepsy. Single administration of cannabidiol during the chronic phase of seizure significantly diminished seizure scores such as mouth clonus, head nodding, monolateral and bilateral forelimb clonus and increased the activity of catalase enzyme and reduced glutathione content. Such a protective effect in the behavioral scores of epileptic rats was also observed after repeated administrations of cannabidiol at the onset of the silent phase. Moreover, the amount of Atg7, conjugation of Atg5/12, Atg12, and LC3II/LC3I ratio increased significantly in epileptic rats treated with repeated injections of cannabidiol. In short, our results suggest that post-treatment of Cannabidiol could enhance the induction of autophagy pathway and antioxidant defense in the chronic phase of epilepsy, which could be considered as the protective mechanisms of cannabidiol in a temporal lobe epilepsy model.

Neurodegenerative disorders are generally characterized by abnormal aggregation and deposition of specific proteins. Amyloid beta (Aβ)-associated neurodegenerative disorder is characterized by an oxidative damage that, in turn, leads to some behavioral changes before the establishment of dementia such as depression and anxiety. In the current study, we investigated the effect of heat shock protein 90 inhibitor geldanamycin (GA) administration 24 h before Aβ injection. In our experiment, 7 days after Aβ injection, elevated plus maze and forced swimming test were conducted to assess anxiety and depression-like behaviors. Levels of autophagy markers and malondialdehyde (MDA) and also activity of catalase in the hippocampus of rats were evaluated. Our behavioral analyses demonstrated that GA pretreatment can significantly decrease anxiety- and depression-like behaviors in Aβ-injected rats. Also, levels of autophagy markers including Atg12, Atg7, and LC3-II increased, while MDA level decreased and the activity of catalase increased in rats pretreated with GA compared to Aβ-injected rats. Thus, we assumed that GA, at least in part, ameliorated Aβ-mediated anxiety and depression by inducing autophagy and improving antioxidant defense system.

It is not known if insulin prevents Aβ-induced cell death, MAPK, and Akt activity in isolated hippocampal cell culture. This study was aimed to explore the effect of insulin on Aβ-induced cell death and ERK and Akt signaling alteration in isolated hippocampal cell culture. Additionally, it was desirable to assess if there is any interaction between these two pathways. The hippocampal cells were derived from fetuses at the embryonic day 18-19. The cells were treated with different drugs, and MTT assay, morphological assessments, and Western blot were done. Insulin prevented Aβ-induced cell death and caspase-3 cleavage. Aβ-induced toxicity was aligned with decrement of the phosphorylated Akt (pAkt) which was prevented by insulin. The PI3 kinase inhibitor, LY294002, decreased pAkt and abolished the protective effect of insulin. Aβ exposure increased phosphorylated ERK (pERK) in parallel with cell death and apoptosis. Insulin-inhibited ERK activation (phosphorylation) induced by Aβ and PD98059 (as ERK inhibitor) did not affect the protective effect of insulin. One of the interesting finding of this study was the interplay of Akt and ERK in Aβ toxicity and insulin-mediated protection; meaning that there is an inverse relation between pERK and pAkt, in a way that PI3-Akt pathway inhibition leads to pERK increment while ERK inhibition causes Akt phosphorylation (activation). This study showed, for the first time, that insulin protects against Aβ toxicity in isolated hippocampal cell culture via modulating Akt and ERK phosphorylation and also revealed an interaction between those signals in Aβ toxicity and insulin-mediated protection.

Anxiety-related disorders are complex illnesses that underlying molecular mechanisms of these complicated emotional disorders are poorly understood. Nuclear factor erythroid 2-related factor 2 (Nrf2) is the most important regulator of the antioxidant defense system. Its protective actions are not only limited to antioxidative transactivation, but also plays important roles in encountering various physiological and pathological stresses. In this study, we evaluated whether silencing of Nrf2 plays a role in development of anxiety-related behavior. In this regard, we exerted small interfering RNA (siRNA) targeting Nrf2 in dorsal third ventricle and subsequently examined the effect of this silencing on anxiety-related behavior along with supposed molecular mechanisms. Therefore, we evaluated apoptotic markers and mitochondrial electron transport chain (ETC) activity in three brain regions: hippocampus, amygdala, and prefrontal cortex. Based on our result, Nrf2-silenced rats exhibited greater anxiety-like behavior compared to control group. Furthermore, Nrf2 silencing increased activity of ETC complexes. Also, Bax/Bcl2 ratio of all mentioned areas of the brain and cleavage of caspase-3 in hippocampus increased in Nrf2 silenced group, however, with a distinct pattern.

Optimized levels of glial cell line-derived neurotrophic factor (GDNF) are critical for protection of dopaminergic neurons against parkinsonian cell death. Recombinant lentiviruses harboring GDNF coding sequence were constructed and used to infect astrocytoma cell line 1321N1. The infected astrocytes overexpressed GDNF mRNA and secreted an average of 2.2 ng/mL recombinant protein as tested in both 2 and 16 weeks post-infection. Serial dilutions of GDNF-enriched conditioned medium from infected astrocytes added to growing neuroblastoma cell line SK-N-MC resulted in commensurate resistance against 6-OHDA toxicity. SK-N-MC cell survival rate rose from 51% in control group to 84% in the cells grown with astro-CM containing 453 pg secreted GDNF, an increase that was highly significant (P < 0.0001). However, larger volumes of the GDNF-enriched conditioned medium failed to improve cell survival and addition of volumes that contained 1,600 pg or more GDNF further reduced survival rate to below 70%. Changes in cell survival paralleled to changes in the percent of apoptotic cell morphologies. These data demonstrate the feasibility of using astrocytes as minipumps to stably oversecrete neurotrophic factors and further indicate that GDNF can be applied to neuroprotection studies in PD pending the optimization of its concentrations.