Neuron-like Cells Research Articles

Cdk5 activation promotes Cos-7 cells transition towards neuronal-like cells.

Cyclin-dependent kinase 5 (Cdk5) activity is specifically active in neurogenesis, and Cdk5 and neocortical neurons migration related biomarker are expressed in Cos-7 cells. However, the function of Cdk5 on the transformation of immortalized Cos-7 cells into neuronal-like cells is not clear. Cdk5 kinase activity was measured by [γ-32P] ATP and p81 phosphocellulose pads based method. The expression of neuron liker markers was evaluated by immunofluorescence, real-time PCR, Western blot, and Elisa. P35 overexpression upregulated Cdk5 kinase activity in Cos-7 cells. p35 mediated Cdk5 expression promoted the generation of nerite-like outgrowth. Compared with the empty vector, p35-induced Cdk5 activation resulted in time-dependent increase in neuron-like marker, including Tau, NF-H, NF-H&M, and TuJ1. Tau-5 and NF-M exhibited increased expression at 48 h while TuJ1 was only detectable after 96 h in p35 expressed Cos-7 cells. Additionally, the neural cell biomarkers exhibited well colocation with p35 proteins. Next-generation RNA sequence showed that p35 overexpression significantly upregulated the level of nerve growth factor (NGF). Gene set enrichment analysis showed significant enrichment of multiple neuron development pathways and increased NGF expression after p35 overexpression. p35-mediated Cdk5 activation promotes the transformation of immortalized Cos-7 cells into neuronal-like cells by upregulating NGF level.

MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1

Mesenchymal stem cell (MSC)-based therapy has emerged as a promising treatment for spinal cord injury (SCI), but improving the neurogenic potential of MSCs remains a challenge. Mixed lineage leukemia 1 (MLL1), an H3K4me3 methyltransferases, plays a critical role in regulating lineage-specific gene expression and influences neurogenesis. In this study, we investigated the role and mechanism of MLL1 in the neurogenesis of stem cells from apical papilla (SCAPs). We examined the expression of neural markers, and the nerve repair and regeneration ability of SCAPs using dynamic changes in neuron-like cells, immunofluorescence staining, and a SCI model. We employed a coimmunoprecipitation (Co-IP) assay, real-time RT-PCR, microarray analysis, and chromatin immunoprecipitation (ChIP) assay to investigate the molecular mechanism. The results showed that MLL1 knock-down increased the expression of neural markers, including neurogenic differentiation factor (NeuroD), neural cell adhesion molecule (NCAM), tyrosine hydroxylase (TH), βIII-tubulin and Nestin, and promoted neuron-like cell formation in SCAPs. In vivo, a transplantation experiment showed that depletion of MLL 1 in SCAPs can restore motor function in a rat SCI model. MLL1 can combine with WD repeat domain 5 (WDR5) and WDR5 inhibit the expression of neural markers in SCAPs. MLL1 regulates Hairy and enhancer of split 1 (HES1) expression by directly binds to HES1 promoters via regulating H3K4me3 methylation by interacting with WDR5. Additionally, HES1 enhances the expression of neural markers in SCAPs. Our findings demonstrate that MLL1 inhibits the neurogenic potential of SCAPs by interacting with WDR5 and repressing HES1. These results provide a potential therapeutic target for promoting the recovery of motor function in SCI patients.

Astrocyte-like subpopulation of NG2 glia in the adult mouse cortex exhibits characteristics of neural progenitor cells.

Glial cells expressing neuron-glial antigen 2 (NG2), also known as oligodendrocyte progenitor cells (OPCs), play a critical role in maintaining brain health. However, their ability to differentiate after ischemic injury is poorly understood. The aim of this study was to investigate the properties and functions of NG2 glia in the ischemic brain. Using transgenic mice, we selectively labeled NG2-expressing cells and their progeny in both healthy brain and after focal cerebral ischemia (FCI). Using single-cell RNA sequencing, we classified the labeled glial cells into five distinct subpopulations based on their gene expression patterns. Additionally, we examined the membrane properties of these cells using the patch-clamp technique. Of the identified subpopulations, three were identified as OPCs, whereas the fourth subpopulation had characteristics indicative of cells likely to develop into oligodendrocytes. The fifth subpopulation of NG2 glia showed astrocytic markers and had similarities to neural progenitor cells. Interestingly, this subpopulation was present in both healthy and post-ischemic tissue; however, its gene expression profile changed after ischemia, with increased numbers of genes related to neurogenesis. Immunohistochemical analysis confirmed the temporal expression of neurogenic genes and showed an increased presence of NG2 cells positive for Purkinje cell protein-4 at the periphery of the ischemic lesion 12 days after FCI, as well as NeuN-positive NG2 cells 28 and 60 days after injury. These results suggest the potential development of neuron-like cells arising from NG2 glia in the ischemic tissue. Our study provides insights into the plasticity of NG2 glia and their capacity for neurogenesis after stroke.

Cell Cycle Reactivation, at the Start of Neurodegeneration, Induced by Forskolin and Aniline in Differentiated Neuroblastoma Cells.

A characteristic hallmark of Alzheimer's disease (AD) is the intracellular accumulation of hyperphosphorylated tau protein, a phenomenon that appears to have associations with oxidative stress, double-stranded DNA breakage, and the de-condensation of heterochromatin. Re-entry into the cell division cycle appears to be involved in the onset of this neurodegenerative process. Indeed, the cell cycle cannot proceed regularly in the differentiated neurons leading to cell death. Here, we induced cell cycle reactivation in neuronal-like cells, obtained by neuroblastoma cells treated with retinoic acid, by exposure to forskolin or aniline. These compounds determine tau hyperphosphorylation or oxidative stress, respectively, resulting in the appearance of features resembling the start of neuronal degeneration typical of AD, such as tau hyperphosphorylation and re-entry into the cell cycle. Indeed, we detected an increased transcriptional level of cyclins and the appearance of a high number of mitotic cells. We also observed a delay in the initiation of the cell cycle when forskolin was co-administered with pituitary adenylate cyclase-activating polypeptide (PACAP). This delay was not observed when PACAP was co-administered with aniline. Our data demonstrate the relevance of tau hyperphosphorylation in initiating an ectopic cell cycle in differentiated neuronal cells, a condition that can lead to neurodegeneration. Moreover, we highlight the utility of neuroblastoma cell lines as an in vitro cellular model to test the possible neuroprotective effects of natural molecules.

CircNCOA4 knockdown attenuates OGD-induced neuron injury through miR-338-5p/PDE4B axis.

Circular RNAs (circRNAs) have been revealed to be involved in the pathology of acute ischemic stroke (AIS). Herein, we aimed to study the role and mechanism of circNCOA4 in ischemic stroke. The neuron-like cell line SK-N-SH of the experiment group was cultured in oxygen-glucose deprivation (OGD) condition. Cell viability and apoptosis were evaluated by cell counting kit-8 and flow cytometry. The oxidative damage and endoplasmic reticulum stress (ERS) were analyzed by measuring the production of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), and ERS-related markers. The binding between miR-338-5p and circNCOA4 or PDE4B (Phosphodiesterase 4B) was confirmed using dual-luciferase reporter and RIP assays. The commercial kit was used for exosome separation. The levels of circNCOA4 and PDE4B were increased, while miR-338-5p expression was decreased by OGD stimulation. OGD stimulation resulted in the apoptosis of neurons and induced oxidative damage and ERS, these effects were attenuated by circNCOA4 knockdown, while reinforced by circNCOA4 overexpression. Mechanistically, circNCOA4 acted as a sponge for miR-338-5p, and PDE4B was a target of miR-338-5p. MiR-338-5p inhibition reversed the neuroprotective effects of circNCOA4 silencing on neurons. Besides, miR-338-5p overexpression could abolish OGD-induced neuron injury, which was reversed by PDE4B upregulation. In addition, circNCOA4 was packaged into exosomes and showed potential diagnostic value for acute ischemic stroke (AIS) patients. CircNCOA4 has potential diagnostic value for AIS patients and promoted OGD-induced neuron injury via the miR-338-5p/PDE4B axis, providing a new insight into the pathology of AIS.

Tanshinone IIA protects motor neuron-like NSC-34 cells against lipopolysaccharide-induced cell injury by the regulation of the lncRNA TCTN2/miR-125a-5p/DUSP1 axis

BackgroundTanshinone IIA (TSIIA) exerts a protective role in spinal cord injury (SCI). However, the mechanism of TSIIA activity in SCI remains to be elucidated. MethodsCell viability and apoptosis were gauged by CCK-8 assay and flow cytometry, respectively. The expression levels of lncRNA TCTN2, miR-125a-5p and DUSP1 were detected by qRT-PCR and western blot. Direct relationship between miR-125a-5p and TCTN2 or DUSP1 was verified by dual-luciferase reporter assay. ResultsIn mouse NSC-34 cells, LPS reduced the expression of TCTN2. TSIIA alleviated cell injury induced by LPS and increased TCTN2 expression in LPS-exposed NSC-34 cells. TCTN2 was a downstream mediator of TSIIA activity. TCTN2 targeted miR-125a-5p, and TCTN2 over-expression attenuated LPS-induced cell damage in NSC-34 cells by down-regulating miR-125a-5p. TCTN2 functioned as a post-transcriptional regulator of DUSP1 expression through miR-125a-5p. DUSP1 was a functional target of miR-125a-5p in controlling NSC-34 cell injury induced by LPS. TSIIA inhibited miR-125a-5p expression and increased the level of DUSP1 protein in LPS-exposed NSC-34 cells. ConclusionOur study establishes a novel mechanism, the TCTN2/miR-125a-5p/DUSP1 axis, at least in part, for the protective activity of TSIIA in cell injury induced by LPS.

Pimecrolimus protects neuron-like SH-SY5Y cells against anti-inflammatory and anti-oxidant effects of both microglial secretome and hydrogen peroxide.

Calcineurin inhibitors have been found to exhibit a preventive role against neuroinflammation, which represents a crucial underlying mechanism in neurodegenerative diseases (ND). Additionally, they possess suppressive effects on the activation of apoptotic pathways, which constitute another mechanism underlying such diseases. Given that pimecrolimus, a calcineurin inhibitor, impedes the synthesis of pro-inflammatory cytokines, such as interleukin (IL)-2, IL-4, and IL-10, and influences apoptotic processes, it is noteworthy to test its potential neuroprotective properties. Thus, the objective of this investigation was to assess the potential protective effects of pimecrolimus against the degenerative consequences of both microglial secretomes and hydrogen peroxide (H2O2), an oxidant agent. The survival rates of HMC3 microglia cells, neuron-like differentiated SH-SY5Y (d-SH-SY5Y) cells, and their co-culture were determined using the 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) method. Furthermore, the levels of pro-inflammatory cytokines IL-1β and IL-6, and anti-inflammatory cytokine IL-10 were measured using ELISA kits, besides total antioxidant and oxidant capacities in conditioned media of cells. Additionally, the effect of pimecrolimus on neurite length in these cell groups was evaluated through morphological observations. This study revealed, for the first time, that pimecrolimus exerts preventive effects on neurodegenerative processes by virtue of its anti-inflammatory and -antioxidant activities. It holds promise as a potential treatment option for ND.

Transplantation of Chemical Compound-Induced Cells from Human Fibroblasts Improves Locomotor Recovery in a Spinal Cord Injury Rat Model.

The development of regenerative medicine using cell therapy is eagerly awaited for diseases such as spinal cord injury (SCI), for which there has been no radical cure. We previously reported the direct conversion of human fibroblasts into neuronal-like cells using only chemical compounds; however, it is unclear whether chemical compound-induced neuronal-like (CiN) cells are clinically functional. In this study, we partially modified the method of inducing CiN cells (termed immature CiN cells) and examined their therapeutic efficacy, in a rat model of SCI, to investigate whether immature CiN cells are promising for clinical applications. Motor function recovery, after SCI, was assessed using the Basso, Beattie, and Bresnahan (BBB) test, as well as the CatWalk analysis. We found that locomotor recovery, after SCI in the immature CiN cell-transplanted group, was partially improved compared to that in the control group. Consistent with these results, magnetic resonance imaging (MRI) and histopathological analyses revealed that nerve recovery or preservation improved in the immature CiN cell-transplanted group. Furthermore, transcriptome analysis revealed that immature CiN cells highly express hepatocyte growth factor (HGF), which has recently been shown to be a promising therapeutic agent against SCI. Our findings suggest that immature CiN cells may provide an alternative strategy for the regenerative therapy of SCI.

Investigating the Therapeutic Potential of Plants and Plant-Based Medicines: Relevance to Antioxidant and Neuroprotective Effects.

Oxidative stress is a common characteristic of psychiatric, neurological, and neurodegenerative disorders. Therefore, compounds that are neuroprotective and reduce oxidative stress may be of interest as novel therapeutics. Phenolic, flavonoid and anthocyanin content, ORAC and DPPH free radical scavenging, and Cu2+ and Fe2+ chelating capacities were examined in variations (fresh/capsule) of Queen Garnet plum (QGP, Prunus salicina), black pepper (Piper nigrum) clove (Syzygium aromaticum), elderberry (Sambucus nigra), lemon balm (Melissa officinalis) and sage (Salvia officinalis), plus two blends (Astralagus membranaceus-lemon balm-rich, WC and R8). The ability of samples to prevent and treat H2O2-induced oxidative stress in SH-SY5Y cells was investigated. Pre-treatment with WC, elderberry, QGP, and clove prevented the oxidative stress-induced reduction in cell viability, demonstrating a neuroprotective effect. Elderberry increased cell viability following oxidative stress induction, demonstrating treatment effects. Clove had the highest phenolic and flavonoid content, DPPH, and Cu2+ chelating capacities, whereas QGP and elderberry were highest in anthocyanins. Black pepper had the highest ORAC and Fe2+ chelating capacity. These findings demonstrate that plant extracts can prevent and treat oxidative stress-induced apoptosis of neuron-like cells in vitro. Further research into phytochemicals as novel therapeutics for oxidative stress in the brain is needed.

Dissociation process of polyalanine aggregates by free electron laser irradiation.

Polyalanine (polyA) disease-causative proteins with an expansion of alanine repeats can be aggregated. Although curative treatments for polyA diseases have not been explored, the dissociation of polyA aggregates likely reduces the cytotoxicity of polyA. Mid-infrared free electron laser (FEL) successfully dissociated multiple aggregates. However, whether the FEL dissociates polyA aggregates like other aggregates has not been tested. Here, we show that FEL at 6.1 μm experimentally weakened the extent of aggregation of a peptide with 13 alanine repeats (13A), and the irradiated 13A exerted lesser cytotoxicity to neuron-like cells than non-irradiated 13A. Then, we applied molecular dynamics (MD) simulation to follow the dissociation process by FEL. We successfully observed how the intermolecular β-sheet of polyA aggregates was dissociated and separated into monomers with helix structures upon FEL irradiation. After the dissociation by FEL, water molecules inhibited the reformation of polyA aggregates. We recently verified the same dissociation process using FEL-treated amyloid-β aggregates. Thus, a common mechanism underlies the dissociation of different protein aggregates that cause different diseases, polyA disease and Alzheimer's disease. However, MD simulation indicated that polyA aggregates are less easily dissociated than amyloid-β aggregates and require longer laser irradiation due to hydrophobic alanine repeats.

ER stress induces caspase-2-tBID-GSDME-dependent cell death in neurons lytically infected with herpes simplex virus type 2.

Neurotropic viruses, including herpes simplex virus (HSV) types 1 and 2, have the capacity to infect neurons and can cause severe diseases. This is associated with neuronal cell death, which may contribute to morbidity or even mortality if the infection is not controlled. However, the mechanistic details of HSV-induced neuronal cell death remain enigmatic. Here, we report that lytic HSV-2 infection of human neuron-like SH-SY5Y cells and primary human and murine brain cells leads to cell death mediated by gasdermin E (GSDME). HSV-2-induced GSDME-mediated cell death occurs downstream of replication-induced endoplasmic reticulum stress driven by inositol-requiring kinase 1α (IRE1α), leading toactivation of caspase-2, cleavage of the pro-apoptotic protein BH3-interacting domain death agonist (BID), and mitochondria-dependent activation of caspase-3. Finally, necrotic neurons released alarmins, which activated inflammatory responses in human iPSC-derived microglia. In conclusion, lytic HSV infection in neurons activates an ER stress-driven pathway to execute GSDME-mediated cell death and promote inflammation.

NeuroD4 converts glioblastoma cells into neuron-like cells through the SLC7A11-GSH-GPX4 antioxidant axis

Cell fate and proliferation ability can be transformed through reprogramming technology. Reprogramming glioblastoma cells into neuron-like cells holds great promise for glioblastoma treatment, as it induces their terminal differentiation. NeuroD4 (Neuronal Differentiation 4) is a crucial transcription factor in neuronal development and has the potential to convert astrocytes into functional neurons. In this study, we exclusively employed NeuroD4 to reprogram glioblastoma cells into neuron-like cells. In vivo, the reprogrammed glioblastoma cells demonstrated terminal differentiation, inhibited proliferation, and exited the cell cycle. Additionally, NeuroD4 virus-infected xenografts exhibited smaller sizes compared to the GFP group, and tumor-bearing mice in the GFP+NeuroD4 group experienced prolonged survival. Mechanistically, NeuroD4 overexpression significantly reduced the expression of SLC7A11 and Glutathione peroxidase 4 (GPX4). The ferroptosis inhibitor ferrostatin-1 effectively blocked the NeuroD4-mediated process of neuron reprogramming in glioblastoma. To summarize, our study demonstrates that NeuroD4 overexpression can reprogram glioblastoma cells into neuron-like cells through the SLC7A11-GSH-GPX4 signaling pathway, thus offering a potential novel therapeutic approach for glioblastoma.

Mixed Medicinal Mushroom Mycelia Attenuates Alzheimer's Disease Pathologies In Vitro and In Vivo.

Alzheimer's disease (AD) is characterized by memory impairment and existence of amyloid-β (Aβ) plaques and neuroinflammation. Due to the pivotal role of oxidative damage in AD, natural antioxidative agents, such as polyphenol-rich fungi, have garnered scientific scrutiny. Here, the aqueous extract of mixed medicinal mushroom mycelia (MMMM)-Phellinus linteus, Ganoderma lucidum, and Inonotus obliquus-cultivated on a barley medium was assessed for its anti-AD effects. Neuron-like PC12 cells, which were subjected to Zn2+, an Aβ aggregator, were employed as an in vitro AD model. The cells pretreated with or without MMMM were assayed for Aβ immunofluorescence, cell viability, reactive oxygen species (ROS), apoptosis, and antioxidant enzyme activity. Then, 5XFAD mice were administered with 30 mg/kg/day MMMM for 8 weeks and underwent memory function tests and histologic analyses. In vitro results demonstrated that the cells pretreated with MMMM exhibited attenuation in Aβ immunofluorescence, ROS accumulation, and apoptosis, and incrementation in cell viability and antioxidant enzyme activity. In vivo results revealed that 5XFAD mice administered with MMMM showed attenuation in memory impairment and histologic deterioration such as Aβ plaque accumulation and neuroinflammation. MMMM might mitigate AD-associated memory impairment and cerebral pathologies, including Aβ plaque accumulation and neuroinflammation, by impeding Aβ-induced neurotoxicity.

Propionic acid induces alterations in mitochondrial morphology and dynamics in SH-SY5Y cells

Propionic acid (PPA) is used to study the role of mitochondrial dysfunction in neurodevelopmental conditions like autism spectrum disorders. PPA is known to disrupt mitochondrial biogenesis, metabolism, and turnover. However, the effect of PPA on mitochondrial dynamics, fission, and fusion remains challenging to study due to the complex temporal nature of these mechanisms. Here, we use complementary quantitative visualization techniques to examine how PPA influences mitochondrial ultrastructure, morphology, and dynamics in neuronal-like SH-SY5Y cells. PPA (5 mM) induced a significant decrease in mitochondrial area (p < 0.01), Feret's diameter and perimeter (p < 0.05), and in area2 (p < 0.01). Mitochondrial event localiser analysis demonstrated a significant increase in fission and fusion events (p < 0.05) that preserved mitochondrial network integrity under stress. Moreover, mRNA expression of cMYC (p < 0.0001), NRF1 (p < 0.01), TFAM (p < 0.05), STOML2 (p < 0.0001), and OPA1 (p < 0.01) was significantly decreased. This illustrates a remodeling of mitochondrial morphology, biogenesis, and dynamics to preserve function under stress. Our data provide new insights into the influence of PPA on mitochondrial dynamics and highlight the utility of visualization techniques to study the complex regulatory mechanisms involved in the mitochondrial stress response.

The ε-Isozyme of Protein Kinase C (PKCε) Is Impaired in ALS Motor Cortex and Its Pulse Activation by Bryostatin-1 Produces Long Term Survival in Degenerating SOD1-G93A Motor Neuron-like Cells.

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and ultimately fatal neurodegenerative disease, characterized by a progressive depletion of upper and lower motor neurons (MNs) in the brain and spinal cord. The aberrant regulation of several PKC-mediated signal transduction pathways in ALS has been characterized so far, describing either impaired expression or altered activity of single PKC isozymes (α, β, ζ and δ). Here, we detailed the distribution and cellular localization of the ε-isozyme of protein kinase C (PKCε) in human postmortem motor cortex specimens and reported a significant decrease in both PKCε mRNA (PRKCE) and protein immunoreactivity in a subset of sporadic ALS patients. We furthermore investigated the steady-state levels of both pan and phosphorylated PKCε in doxycycline-activated NSC-34 cell lines carrying the human wild-type (WT) or mutant G93A SOD1 and the biological long-term effect of its transient agonism by Bryostatin-1. The G93A-SOD1 cells showed a significant reduction of the phosphoPKCε/panPKCε ratio compared to the WT. Moreover, a brief pulse activation of PKCε by Bryostatin-1 produced long-term survival in activated G93A-SOD1 degenerating cells in two different cell death paradigms (serum starvation and chemokines-induced toxicity). Altogether, the data support the implication of PKCε in ALS pathophysiology and suggests its pharmacological modulation as a potential neuroprotective strategy, at least in a subgroup of sporadic ALS patients.

Bioprinting 3D muscle tissue supplemented with endothelial-spheroids for neuromuscular junction model

The neuromuscular junction (NMJ) plays a critical role in muscle contraction, and its dysfunction can result in various neuromuscular disorders. In vitro models for studying NMJ are essential for understanding their functions and pathology. However, the engineering of muscle tissue presents challenges for the organization of myofiber-like oriented muscle bundles as well as the induction of vessel formation and innervation. To address these challenges, we fabricated a hybrid muscle construct comprising uniaxially aligned muscle struts and endothelial cell spheroids using a combination of in situ electric field-assisted bioprinting (E-printing) and microdroplet-based spheroid-forming bioprinting (MDS-printing) techniques. This resulted in self-aggregation of human umbilical vein endothelial cells (HUVECs) into spheroids without attachment to the structures. We tested various fabrication parameters, such as electric field and cross-linking conditions, for E-printing and the deposited cell density of MDS-printing, to stabilize the alignment of the human muscle progenitor cells (hMPCs) and HUVEC spheroids, respectively. The stimulated hMPCs efficiently formed fully aligned myofibers, and the incorporation of HUVEC spheroids induced highly upregulated crosstalk between different cell types compared to a simple E-printed hMPC/HUVEC mixture-loaded construct. This improved myogenesis and vessel formation in vitro. In addition, when co-cultured with a motor neuron-like cell (NSC-34) spheroid separated by a channel, we observed considerably improved neuromuscular junction formation compared to those formed with the normally mixed cell-bearing structures. Our findings suggest that this hybrid muscle construct has the potential to enhance muscle tissue engineering by improving biological activities through the incorporation of HUVEC-spheroids and facilitating neuromuscular junction formation through co-culture with NSC-34 spheroids.

Dietary fatty acids differentially impact phagocytosis, inflammatory gene expression, and mitochondrial respiration in microglial and neuronal cell models.

The consumption of diets high in saturated fatty acids and/or refined carbohydrates are associated with neuroinflammation, cognitive dysfunction, and neurodegenerative disease. In contrast, diets high in polyunsaturated fatty acids are associated with anti-inflammatory and neuroprotective effects. We have previously shown that high fat diet (HFD) consumption increases saturated fatty acids and decreases polyunsaturated fatty acids in the hippocampus. We have further shown that HFD elicits exaggerated neuroinflammation and reduced synaptic elements, and results in robust memory deficits in aged rats. Here, we examined the impact of palmitate, an abundant dietary saturated fat, on a variety of cellular responses in BV2 microglia and HippoE-14 neurons, and the extent to which the omega-3 fatty acid, docosahexaenoic acid (DHA), would buffer against these responses. Our data demonstrate that DHA pretreatment prevents or partially attenuates palmitate-induced alterations in proinflammatory, endoplasmic reticulum stress, and mitochondrial damage-associated gene expression in both cell types. Furthermore, we show that synaptoneurosomes isolated from aged, HFD-fed mice are engulfed by BV2 microglia at a faster rate than synaptoneurosomes isolated from aged, chow-fed mice, suggesting HFD alters signaling at synapses to hasten their engulfment by microglia. Consistent with this notion, we found modest increases in complement proteins and a decrease in CD47 protein expression on synaptoneurosomes isolated from the hippocampus of aged, HFD-fed mice. Interestingly, palmitate reduced BV2 microglial phagocytosis, but only of synaptoneurosomes isolated from chow-fed mice, an effect that was prevented by DHA pretreatment. Lastly, we measured the impact of palmitate and DHA on mitochondrial function in both microglial and neuronal cell models using the Seahorse XFe96 Analyzer. These data indicate that DHA pretreatment does not mitigate palmitate-induced reductions in mitochondrial respiration in BV2 microglia and HippoE-14 neurons, suggesting DHA may be acting downstream of mitochondrial function to exert its protective effects. Together, this study provides evidence that DHA can ameliorate the negative impact of palmitate on a variety of cellular functions in microglia- and neuron-like cells.

Neuroprotective Effect of NO-Delivery Dinitrosyl Iron Complexes (DNICs) on Amyloid Pathology in the Alzheimer's Disease Cell Model.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive impairment, memory loss, and behavioral deficits. β-amyloid1-42 (Aβ1-42) aggregation is a significant cause of the pathogenesis in AD. Despite the numerous types of research, the current treatment efficacy remains insufficient. Hence, a novel therapeutic strategy is required. Nitric oxide (NO) is a multifunctional gaseous molecule. NO displays a neuroprotective role in the central nervous system by inhibiting the Aβ aggregation and rescuing memory and learning deficit through the NO signaling pathway. Targeting the NO pathway might be a therapeutic option; however, NO has a limited half-life under the biological system. To address this issue, a biomimetic dinitrosyl iron complex [(NO)2Fe(μ-SCH2CH2COOH)2Fe(NO)2] (DNIC-COOH) that could stably deliver NO was explored in the current study. To determine whether DNIC-COOH exerts anti-AD efficacy, DNIC-COOH was added to neuron-like cells and primary cortical neurons along with Aβ1-42. This study found that DNIC-COOH protected neuronal cells from Aβ-induced cytotoxicity, potentiated neuronal functions, and facilitated Aβ1-42 degradation through the NO-sGC-cGMP-AKT-GSK3β-CREB/MMP-9 pathway.

Inducing Mechanical Stimuli to Tissues Grown on a Magnetic Gel Allows Deconvoluting the Forces Leading to Traumatic Brain Injury.

Traumatic brain injury (TBI), which is characterized by damage to the brain resulting from a sudden traumatic event, is a major cause of death and disability worldwide. It has short- and long-term effects, including neuroinflammation, cognitive deficits, and depression. TBI consists of multiple steps that may sometimes have opposing effects or mechanisms, making it challenging to investigate and translate new knowledge into effective therapies. In order to better understand and address the underlying mechanisms of TBI, we have developed an in vitro platform that allows dynamic simulation of TBI conditions by applying external magnetic forces to induce acceleration and deceleration injury, which is often observed in human TBI. Endothelial and neuron-like cells were successfully grown on magnetic gels and applied to the platform. Both cell types showed an instant response to the TBI model, but the endothelial cells were able to recover quickly-in contrast to the neuron-like cells. In conclusion, the presented in vitro model mimics the mechanical processes of acceleration/deceleration injury involved in TBI and will be a valuable resource for further research on brain injury.

Short- and Long-Term Regulation of HuD: A Molecular Switch Mediated by Folic Acid?

The RNA-binding protein HuD has been shown to play a crucial role in gene regulation in the nervous system and is involved in various neurological and psychiatric diseases. In this study, through the creation of an interaction network on HuD and its potential targets, we identified a strong association between HuD and several diseases of the nervous system. Specifically, we focused on the relationship between HuD and the brain-derived neurotrophic factor (BDNF), whose protein is implicated in several neuronal diseases and is involved in the regulation of neuronal development, survival, and function. To better investigate this relationship and given that we previously demonstrated that folic acid (FA) is able to directly bind HuD itself, we performed in vitro experiments in neuron-like human SH-SY5Y cells in the presence of FA, also known to be a pivotal environmental factor influencing the nervous system development. Our findings show that FA exposure results in a significant increase in both HuD and BDNF transcripts and proteins after 2 and 4 h of treatment, respectively. Similar data were obtained after 2 h of FA incubation followed by 2 h of washout. This increase was no longer detected upon 24 h of FA exposure, probably due to a signaling shutdown mechanism. Indeed, we observed that following 24 h of FA exposure HuD is methylated. These findings indicate that FA regulates BDNF expression via HuD and suggest that FA can behave as an epigenetic modulator of HuD in the nervous system acting via short- and long-term mechanisms. Finally, the present results also highlight the potential of BDNF as a therapeutic target for specific neurological and psychiatric diseases.