A proteomic analysis for profiling NeuroD2 related changes in N2A neuroblastoma cell line

Aim: NeuroD2 transcription factor is a key regulator of neurogenin-NeuroD signaling network and induces neuronal development, differentiation, neurogenesis and calcium de- pendent signaling. NeuroD2 regulates expression of survival and plasticity related proteins in neurons. Surprisingly, inhibition of NeuroD2 causes an increase in apoptotic cell death. Even though previous studies found out important data about NeuroD2 function, molec- ular interactions of NeuroD2 behind all of these impacts remains elusive. For this reason, it was aimed to shed light on the proteome profile of NeuroD2 based changes in the N2A cell line. Materials and Methods: NeuroD2 over-expression and NeuroD2 inhibition groups were constructed via lentiviral vectors. Mouse N2A cell line was transfected with the given vectors and incubated for 6 hours. After incubation samples were prepared for proteomic analyses with Filter Aided Sample Preparation (FASP) protocol and LC-MS/MS analysis was carried out. Results: Under conditions of overexpression and inhibition, detected proteins were fil- tered according to significant cut off values. The filtered proteins were further investigated to exhibit a coherent expression in each situation. Eventually, increased NeuroD2 activity was accompanied by an increase in N-alpha-acetyltransferase 25 (NAA25), and Synapto- brevin homolog (YKT6). On the other hand, when NeuroD2 was suppressed, expression of Cytoplasmic Dynein 1 Light Intermediate Chain 1, Kinesin-Like Protein (KIF-11), Leucine-tRNA Ligase (LARS1), and Ubiquitin-Associated Protein 2 (UBA2) were found to be upregulated with a reverse action. Conclusion: Up-regulations of the proteins Cytoplasmic Dynein 1, KIF11, LARS1, and UBA2 suggested that these proteins might be controlled by inhibition of NeuroD2. In this contex it can be said that, axonal transport, neuronal signaling, and activity of PI3K/AKT pathway can be indirectly regulated by NeuroD2

Kaempferol treatment ameliorates memory impairments in STZ-induced neurodegeneration by acting on reelin signaling

Many treatment initiatives, like herbal products and their active ingredients, aim to alleviate neurodegeneration to increase cognitive functions. Kaempferol may be a candidate molecule for treating neurodegeneration because of its antioxidant effects. In the present study, we examined the molecular changes associated with kaempferol’s memory-enhancing effects on streptozotocin (STZ)-induced neurodegeneration. After intracerebroventricular STZ injection in Long-Evans male rats, intraperitoneal kaempferol was administered for 12 days. The Morris water maze (MWM) was used to measure learning and memory performance in the rats, and proteins related to memory formation were investigated in the hippocampi with western blotting. Kaempferol improved learning performance and memory decline in STZ-treated rats. At the molecular level, STZ-induced neurodegeneration resulted in a decrease in the expression of GAD67, reelin, and phosphorylated-NMDAR. However, kaempferol treatment ameliorated these changes by enhancing their levels similar to the controls. While neither STZ injection nor kaempferol treatment produced any significant change in phosphorylated-CAMKII levels, they increased the expression of klotho and prealbumin. These results show that kaempferol has positive effects on memory loss, affecting synaptic plasticity by ameliorating both the levels and activity of memory-relevant molecules through reelin signaling. In summary, this study provides a guide to future studies by examining in detail the healing effect of kaempferol as a candidate molecule in the treatment of neurodegeneration, such as that observed in Alzheimer’s disease

Prenatal ethanol intoxication and maternal intubation stress alter cell survival and apoptosis in the postnatal development of rat hippocampus

It is well known that the fetal ethanol exposure and prenatal stress may have adverse effects on brain development. Interestingly, some morphological and functional recovery from their teratogenic effects that take place during brain maturation. However, mechanisms that underlie this recovery are not fully elucidated. The aim of this study was to examine whether the postnatal attenuation of fetal alcohol - and maternal stress-induced morphological and functional deficits correlates with compensatory changes in the expression/activation of the brain proteins involved in inflammation, cell survival and apoptosis. In this project, we investigated the hippocampus which belongs to the brain regions most susceptible to the adverse effects of prenatal ethanol exposure. Pregnant rat dams were administered ethanol (A) or isocaloric glucose solution (IC) by a gastric intubation during gestational days 7-20. The pure control group received ad libitum laboratory chow and water with no other treatment. The hippocampi of fetal-ethanol and control pups were examined at the postnatal day (PD)1, PD10, PD30 and PD60. Moderate fetal-ethanol exposure and prenatal intubation stress caused a significant increase in molecular factors relating to inflammation (iNOS) and cell survival/apoptosis pathways (PTEN, GSK-3 and ERK) at birth, with a rapid compensation from these developmental deficits upon removal of alcohol at PD10. Indeed, an increase in ERK1/2 and JNK1/2 activation at PD30 was observed with ethanol consumption. It indicates that the recovery process in A and IC brains started soon after the birth upon the ethanol and stressor withdrawal and continued until the adulthood

Effects of GDNF on neurovascular structures during recovery process after cerebral ischemia

..

Effects of fetal alcohol and maternal intubation stress on the expression of proteins controlling postnatal development of male rat hippocampus

Background Developing brains can partially get over prenatal alcohol exposure-related detrimental conditions by activating some mechanisms involved in survival. Objectives This study aimed to shed light on the molecular correlates of compensatory mechanisms by examining temporal profiles in the expression of proteins controlling postnatal development in the rat hippocampus prenatally exposed to intubation stress/ethanol. Methods Male pups were randomly assigned to age subgroups (n = 21/age) which were sacrificed on postnatal day (PD)1, PD10, PD30, and PD60. Ethanol (6 g/kg/day) were intragastrically intubated to the dams throughout 7-21 gestation days. The expression of neurogenesis and angiogenesis markers, extracellular matrix proteins, and growth-promoting ligands were examined by western blot. Results The most rapid increase in the index of neuronal maturation was noted between PD10-PD30 (p< .05). Prenatal stress caused a decrease of neurogenesis markers at birth and an increase of their expressions at PD10 and PD30 to reach control levels (p< .001). The impact of fetal-alcohol was observed as a decrease in the expression of synaptic plasticity protein versican at birth (p< .001), an increase in the synaptic repulsion protein ephrin-B2 at PD10 (p< .001), and a decrease in the maturation of BDNF at PD30 (p< .001) with a decrease in the mature neuron markers at PD30 (p< .001) and PD60 (p= .005) which were compensated with upregulation of angiogenesis and increasing brevican expression, a neuronal maturation protein (p< .001). Conclusion These data providein vivoevidence for the potential therapeutic factors related to neurogenesis, angiogenesis, and neurite remodeling which may tolerate the alcohol/stress dependent teratogenicity in the developing hippocampus

Striatal dopaminergic neurons as a potential target for GDNF based ischemic stroke therapy

Background/aim: Glial cell-line-derived neurotrophic factor (GDNF) is a well-known regulatory neurotrophic factor on dopaminergic neurons. Several pathologies have been documented so far in case of any impairment in the dopaminergic system. This study aimed to investigate the potential protective role of lentiviral GNDF delivery on the small population of tyrosine hydroxylase (TH) positive dopamine producing striatal neurons after ischemic stroke. Materials and methods: Fourteen C57BL/6J male mice (8–10 weeks) were intracerebrally treated with lentiviral GDNF (Lv-GDNF) or vehicle. Ten days after injections, cerebral ischemia was induced by blockage of the middle cerebral artery. Animals were terminated 72 h after ischemia, and their brains were taken for histological and molecular investigations. Following confirmation of GDNF overexpression, TH immunostaining and immunoblotting were used to evaluate the role of GDNF on dopaminergic neurons. Next, Fluro Jade C staining was implemented to examine the degree of neuronal degeneration at the damaged parenchyma. Results: Neither the amount of TH positive dopaminergic neurons nor the expression of TH changed in the Lv-GDNF treated animals comparing to the vehicle group. On the other hand, GDNF exposure caused a significant increase in the expression of Nurr1, an essential transcription factor for dopaminergic neurons and Gap43, growth and plasticity promoting protein, in the ischemic striatum. Treatment with Lv-GDNF gave rise to a significant reduction in the number of degenerated neurons. Finally, enhanced GDNF expression also induced expression of an important stress-related transcription factor NF-κB as well as the nitric oxide synthase enzymes iNOS and nNOS in the contralesional hemisphere. Conclusion: Considering these results together, GDNF’s impact on the survival of striatal dopaminergic neurons is not outstanding for its neuroprotective role. However, it seems that GDNF conducts several signaling pathways by acting on key transcription factors and shows its protective feature by fine-tuning the degeneration-related processes

Effect of P2X7 receptor on activation of microglia and IL1 beta following ischemia

..

Inflammatory cytokines are in action: Brain plasticity and recovery after brain ischemia due to delayed melatonin administration

Objectives: Post-ischemic inflammation leads to apoptosis as an indirect cause of functional disabilities after the stroke. Melatonin may be a good candidate for the stroke recovery because of its anti-inflammatory effects. Therefore, we investigated the effect of melatonin on inflammation in the functional recovery of brain by evaluating ipsilesional and contralesional alterations. Materials and Methods: Melatonin (4 mg/kg/day) was intraperitoneally administered into the mice from the 3rd to the 55th day of the post-ischemia after 30 min of middle cerebral artery occlusion. Results: Melatonin produced a functional recovery by reducing the emigration of the circulatory leukocytes and the local microglial activation within the ischemic brain. Overall, the expression of the inflammation-related genes reduced upon melatonin treatment in the ischemic hemisphere. On the other hand, the expression level of the inflammatory cytokine genes raised in the contralateral hemisphere at the 55th day of the post-ischemia. Furthermore, melatonin triggers an increase in the iNOS expression and a decrease in the nNOS expression in the ipsilateral hemisphere at the earlier times in the post-ischemic recovery. At the 55th day of the post-ischemic recovery, melatonin administration enhanced the eNOS and nNOS protein expressions. Conclusions: The present molecular, biological, and histological data have revealed broad anti-inflammatory effects of melatonin in both hemispheres with distinct temporal and spatial patterns at different phases of post-stroke recovery. These outcomes also established that melatonin act recruitment of contralesional rather than of ipsilesional

Delayed Therapeutic Administration of Melatonin Enhances Neuronal Survival Through AKT and MAPK Signaling Pathways Following Focal Brain Ischemia in Mice

Melatonin has a role in the cell survival signaling pathways as a candidate for secondary stroke prevention. Therefore, in the present study, the coordination of ipsilateral and contralateral hemispheres to evaluate delayed post-acute effect of melatonin was examined on recovery of the cell survival and apoptosis after stroke. Melatonin was administered (4 mg/kg/day) intraperitoneally for 45 days, starting 3 days after 30 min of middle cerebral artery occlusion. The genes and proteins related to the cell survival and apoptosis were investigated by immunofluorescence, western blotting, and RT-PCR techniques after behavioral experiments. Melatonin produced delayed neurological recovery by improving motor coordination on grip strength and rotarod tests. This neurological recovery was also reflected by high level of NeuN positive cells and low level of TUNEL-positive cells suggesting enhanced neuronal survival and reduced apoptosis at the fifty-fifth day of stroke. The increase of NGF, Nrp1, c-jun; activation of AKT; and dephosphorylation of ERK and INK at the fifty-fifth day showed that cell survival and apoptosis signaling molecules compete to contribute to the remodeling of brain. Furthermore, an increase in the CREB and Atf-1 expressions suggested the melatonin's strong reformative effect on neuronal regeneration. The contralateral hemisphere was more active at the latter stages of the molecular and functional regeneration which provides a further proof of principle about melatonin's action on the promotion of brain plasticity and recovery after stroke

Plasticity-promoting effect of melatonin after experimental cerebral ischemia

..