Melis Savasan Sogut

Elk-1, a member of the ternary complex factors (TCFs) within the ETS (E26 transformation-specific) domain superfamily, is a transcription factor implicated in neuroprotection, neurodegeneration, and brain tumor proliferation. Except for known targets, c-fos and egr-1, few targets of Elk-1 have been identified. Interestingly, SMN, SOD1, and PSEN1 promoters were shown to be regulated by Elk-1. On the other hand, Elk-1 was shown to regulate the CD133 gene, which is highly expressed in brain-tumor-initiating cells (BTICs) and used as a marker for separating this cancer stem cell population. In this study, we have carried out microarray analysis in SH-SY5Y cells overexpressing Elk-1-VP16, which has revealed a large number of genes significantly regulated by Elk-1 that function in nervous system development, embryonic development, pluripotency, apoptosis, survival, and proliferation. Among these, we have shown that genes related to pluripotency, such as Sox2, Nanog, and Oct4, were indeed regulated by Elk-1, and in the context of brain tumors, we further showed that Elk-1 overexpression in CD133+ BTIC population results in the upregulation of these genes. When Elk-1 expression is silenced, the expression of these stemness genes is decreased. We propose that Elk-1 is a transcription factor upstream of these genes, regulating the self-renewal of CD133+ BTICs.

Parkinson’s disease (PD) is the second most common neurodegenerative disease with an estimation of 10 million people living with the disease and it is increasing in prevalence every year. Familial cases of PD are source of valuable information to determine genetical risk factors yet sporadic cases can emerge from distinct mechanisms so, identifying common pathways of familial and sporadic cases of PD may provide worthwhile insights to determine underlying mechanisms through the progression. LRRK2 mutations are the most common indicators of both sporadic and familial cases of PD and α-synuclein aggregation is one of the hallmarks of both cases of PD as well as in other synucleinopathies. As in the case of most neurological diseases, human studies addressing the molecular basis of pathology are generally restricted to post-mortem materials. For this reason, cell culture systems and animal models are widely used. There are two main approaches for modelling PD: genetically constructed PD models and neuroxin-based models. In this study, we aim to construct and compare both approaches by overexpressing wild-type (WT) and A53T mutant α-synuclein and treating cells with well-known neurotoxin 6-hydroxidopamine (6-OHDA) using dopaminergic human neuroblastoma SH-SY5Y cell line. Our findings suggest that WT or A53T α-synuclein overexpression by itself is not sufficient to cause significant toxicity in SH-SY5Y cells in the presented time scale. As expected, 6-OHDA treatment caused toxicity with an IC50 value of ~100 µM. In addition, 6-OHDA treatment causes 3- and 2.5-fold increase in SNCA and LRRK2 expression respectively.

To the best of our knowledge, this is the first study concerning the effect of boric acid (BA) administration on fetal alcohol syndrome (FAS). In this study, the aim was to investigate prenatal alcohol‑induced oxidative stress on the cerebral cortex of newborn rat pups and assess the protective and beneficial effects of BA supplementation on rats with FAS. Pregnant rats were divided into three groups, namely the control, alcohol and alcohol + boric acid groups. As markers of alcohol‑induced oxidative stress in the cerebral cortex of the newborn pups, malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) levels were measured. Although the MDA levels in the alcohol group were significantly increased compared with those in the control group (P<0.05), the MDA level in the alcohol + boric acid group was shown to be significantly decreased compared with that in the alcohol group (P<0.01). The CAT activity of the alcohol + boric acid group was significantly higher than that in the alcohol group (P<0.05). The GPx activity in the alcohol group was decreased compared with that in the control group (P<0.05). These results demonstrate that alcohol is capable of triggering damage to membranes of the cerebral cortex of rat pups and BA could be influential in antioxidant mechanisms against oxidative stress resulting from prenatal alcohol exposure.

Pea3 subfamily of ETS transcription factors consist of three major proteins, Pea3, ERM and ER81. Although important for many different tissues that exhibit branching morphogenesis, the function of Pea3 family in nervous system development and regeneration is only beginning to unfold. In this study, we provide evidence that Pea3 can directs neurite extension and axonal outgrowth in different model systems, and that Serine 90 is important for this function. We have also identified neurofilament-L and neurofilament-M as two putative novel targets for Pea3.