Molecular Neurobiology最新文献

We employed single-cell transcriptome sequencing to reveal the dynamic gene expression changes during the differentiation of adipose-derived stromal cells (ADSCs) into astrocytes. Single-cell RNA sequencing was conducted on cells from the ADSCs group and the induced groups at 2, 7, 14, and 21 days using the 10 × Chromium platform. Data underwent quality control and dimensionality reduction. Cell differentiation trajectories were constructed using Monocle2, and differentially expressed genes (DEGs) in each cell cluster were identified using differential selection algorithms. DEGs at each time point were annotated using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), and regulatory intensities of transcription factors were analyzed using SCENIC. Integrating all groups, a total of five samples were divided into 13 cell clusters (0-12 clusters). DEGs between clusters and those compared with ADSCs at various induced time points showed distinct specificities. Monocle2 constructed cell differentiation trajectories; ADSCs can differentiate into mature astrocytes not only through the direct pathway from the 1 branch to the 3 branch but also through an indirect pathway, involving the 1 branch to the 2 branch before progressing to the 3 branch. SCENIC analysis highlighted the critical regulatory roles of STAT1, MYEF2, and SOX6 transcription factors during the differentiation of ADSCs into astrocytes. ADSCs can differentiate into mature astrocytes through two distinct pathways: direct and indirect. By the 14th day of induction, mature astrocytes have formed, characterized by a cell cycle arrest in mitosis. Further induction leads to degenerative senescence changes in differentiated cells.

Parkinson's disease (PD) ranks as the second most prevalent neurodegenerative disorder, and while the neuroprotective effects of estrogen are well-documented, the impact of androgens on neurological disorders remains understudied. The consequences of exposure to 17-trenbolone (17-TB), an environmental endocrine disruptor with androgen-like properties, on the mammalian nervous system have received limited attention. Therefore, in this study, we aimed to investigate the biological effects of 17-TB exposure on PD. In our investigation using the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mouse model, we discovered that 17-TB exposure elevated testosterone hormone levels prevented androgen receptor (AR) reduction, upregulated the expression of muscular dystrophic factors (Atrogin1, MuRF1, Musa1, and Myostatin), improved muscle strength, and enhanced locomotor activity in the open field test. However, it is noteworthy that exposure to 17-TB also led to an upregulation of neuroinflammatory cytokines (NLRP3, IL-6, IL-1α, and IL-1β) in PD mice. Crucially, 17-TB exposure induced downregulation of nigral apoptotic proteins DJ-1 and Bcl-2 while upregulating Bax and Caspase-3 in PD mice. This exacerbated neuronal apoptosis, ultimately intensifying dopaminergic neuronal degeneration and death in the substantia nigra and striatum of PD mice. In conclusion, our findings indicate that while 17-TB mitigates muscle atrophy and enhances motor activity in PD mice, it concurrently exacerbates neuroinflammation, induces neuronal apoptosis, and worsens dopaminergic neuronal death, thereby aggravating the progression of MPTP-induced Parkinsonism. This underscores the importance of considering potential environmental risks in neurodegeneration associated with Parkinson's disease, providing a cautionary tale for our daily exposure to environmental endocrine chemical disruptors.

Chemobrain is a cognitive impairment observed in up to 75% of cancer patients treated with doxorubicin (DOX). Cognitive deficits associated with DOX are complex, and multiple interplay pathways contribute to memory impairment and the loss of concentration. Empagliflozin (EMPA), a sodium-glucose co-transporter-2 (SGLT-2) inhibitor with neuroprotective potential, has recently been elucidated because of its regulatory effects on oxidative stress and neuroinflammation. Thus, this study aimed to explore the protective mechanisms of EMPA in DOX-induced chemobrain. Rats were allocated to four groups: normal (NC), EMPA, DOX, and EMPA + DOX. Chemobrain was induced in the third and fourth groups by DOX (2 mg/kg, IP) on the 0th, 7th, 14th, and 21st days of the study, while EMPA was administered (10 mg/kg, PO) for 28 consecutive days in both the EMPA and EMPA + DOX groups. Behavioral and biochemical assessments were then performed. Rats treated with DOX exhibited significant memory, learning, and muscle coordination dysfunctions. Moreover, DOX boosted oxidative stress in the brain, as evidenced by elevated malondialdehyde (MDA) content together with decreased levels of nuclear factor-erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) and reduced glutathione (GSH). Neuroinflammation was also observed as an upsurge of tumor necrosis factor-alpha (TNF-α) and nuclear factor kappa B (NF-κB) (p65). Additionally, DOX diminished the expression of brain-derived neurotrophic factor (BDNF) and increased phosphoinositol-3-kinase (PI3K), phosphorylated-Akt (pAkt), and mammalian target of rapamycin (mTOR) content. EMPA exhibited potent neuroprotective potential in DOX-induced cognitive impairment, attributed to its antioxidant and neuroplasticity-enhancing properties and suppression of the PI3K/Akt/mTOR/NF-κB/TNF-α signaling pathway.

Azadiradione is a brain-permeable phytochemical present in the seed of an Indian medicinal plant, Azadirachta Indica, well known as neem. Recently, this small bioactive molecule has been revealed to induce the expression of Ube3a, a ubiquitin ligase whose loss and gain of function are associated with two diverse neurodevelopmental disorders. Here, we report that in utero exposure to azadiradione in mice results in severe developmental disabilities. Treatment of a well-tolerated dose of azadiradione into the pregnant dam (at embryonic days 12 and 14) causes a substantial decrease in the body weight of the newborn pups during their early developmental periods along with significant cognitive, motor, and communication deficits and increased anxiety-like behaviors. As the animals grow from adolescence to adulthood, their body weight and many behavioral deficits are gradually restored to normalcy, although the cognitive deficit persists significantly. Biochemical analysis reveals that the azadiradione prenatally exposed mice brain exhibits about 2-3 fold increase in the level of Ube3a at postnatal day 25 along with a significant increase in some of its target proteins linked to synaptic function and plasticity, indicating the enduring effect of the drug on Ube3a expression. The prenatally azadiradione-exposed mice also display increased dendritic spines in the hippocampal and cortical pyramidal neurons. These results suggest that Ube3a might be one of the key players in azadiradione-induced developmental disabilities.

Epilepsy represents the most prevalent chronic neurological disease, characterized by spontaneous recurrent seizures. In experimental epilepsy models created by different methods, resveratrol has been demonstrated to reduce epileptiform activity and exhibit neuroprotective properties. A penicillin-induced model of epileptogenesis was used to investigate the effects of resveratrol and its combination with sodium valproate on epileptiform activity. The study design was an in vivo animal experimental study. Forty Wistar-albino rats were divided into five groups, each with eight rats. The groups are categorized as the saline group, penicillin group (only penicillin), resveratrol group, sodium valproate group, and resveratrol + sodium valproate group. ECoG recording was taken for 180 min in all groups and statistically evaluated. GABAα1, mGluR1/mGluR5, NMDAR1 receptor expressions in the hippocampus, and S100B level in serum were measured. The spike frequency decreased statistically to 60th min in the sodium valproate group and 150th min in the resveratrol group. The spike frequency decreased statistically in the 20th min and later measurements of the recording in the resveratrol + sodium valproate group. GABAα1 receptor expression was increased in all groups compared to the penicillin group. mGluR1/mGluR5, NMDAR1 receptor expression was decreased in all groups compared to the penicillin group. Serum S100B level increased in all groups compared to the penicillin group. There was no statistically significant difference in epileptiform activity when resveratrol alone was administered in the penicillin-induced epilepsy model. Resveratrol co-administered with sodium valproate significantly reduced epileptiform activity. Co-administration of the sodium valproate + resveratrol group made the receptor level's highest GABAα1receptor expression at receptors.

Studies in the existing literature propose that allocryptopine possesses both antioxidant and anti-inflammatory properties, showcasing its neuroprotective effects by potentially mitigating oxidative stress and inflammation. This study aims to investigate the antioxidant and anti-inflammatory effects of allocryptopine on various targets and potential mechanisms that have not been previously explored in the literature. Initially, we used MTT and LDH methods to evaluate the effects of allocryptopine on cell viability in BV-2 cells exposed to LPS-induced damage. Subsequently, we evaluated the impact of allocryptopine on pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), other inflammatory mediators (Cox-2 and iNOS), and p38 MAPK genes and proteins through qRT-PCR and Western blot analyses. Also, we evaluated the impact of allocryptopine on NF-κB proteins (TLR4, MyD88, IκBα, p-p50, and p-p65) through ELISA assay. Molecular docking analyses were performed to investigate the potential binding of allocryptopine to target proteins (TLR4, MyD88, IκBα, p50, p65, MKK3, MKK4, MKK6, p38, AP-1 (c-Jun and ATF2), IL-1β, IL-6, TNF-α, Cox-2, and iNOS) associated with the TLR4, NF-κB, and p38 MAPK pathways. Our results indicate that allocryptopine exerts a comprehensive influence on pro-inflammatory cytokines and other inflammatory mediators by inhibiting TLR4 signaling and modulating the NF-κB and p38 MAPK pathways. The outcomes of our study suggest that the antioxidant and anti-inflammatory efficacy of allocryptopine is intricately linked to the modulation of key molecular pathways associated with oxidative stress and inflammation. These findings highlight the potential of allocryptopine as a therapeutic agent for addressing neurodegenerative diseases by safeguarding neuronal health.

Ferroptosis, a regulated form of cell death characterized by excessive iron-dependent lipid peroxidation, can be readily induced in cultured cells by chemicals such as erastin and RSL3. Protein disulfide isomerase (PDI) has been identified as an upstream mediator of chemically induced ferroptosis and also a target for ferroptosis protection. In this study, we discovered that raloxifene (RAL), a selective estrogen receptor modulator known for its neuroprotective actions in humans, can effectively inhibit PDI function and provide robust protection against chemically induced ferroptosis in cultured HT22 neuronal cells. Specifically, RAL can bind directly to PDI both in vitro and in intact neuronal cells and inhibit its catalytic activity. Computational modeling analysis reveals that RAL can tightly bind to PDI through forming a hydrogen bond with its His256 residue, and biochemical analysis further shows that when PDI's His256 is mutated to Ala256, RAL loses its inhibition of PDI's catalytic activity. This inhibition of PDI by RAL significantly reduces the dimerization of both the inducible and neuronal nitric oxide synthases and the accumulation of nitric oxide, both of which have recently been shown to play a crucial role in mediating chemically induced ferroptosis through subsequent induction of ROS and lipid-ROS accumulation. In vivo behavioral analysis shows that mice treated with RAL are strongly protected against kainic acid-induced memory deficits and hippocampal neuronal damage. In conclusion, this study demonstrates that RAL is a potent inhibitor of PDI and can effectively prevent chemically induced ferroptosis in hippocampal neurons both in vitro and in vivo. These findings offer a novel estrogen receptor-independent mechanism for RAL's neuroprotective actions in animal models and humans.

Acrylamide (ACR) is a water-soluble monomer with broad consumer applications, even in foods due to thermal processes. Acute exposure to ACR may lead to neurotoxic effects such as ataxia and skeletal muscle weakness in humans and experimental animals. Oxidative stress is the primary pathway in ACR toxicity; therefore, this study aimed to evaluate the possible protective effect of benzo[b]thiophene analogs as an antioxidant drug for ACR poisoning. For this purpose, adult zebrafish were chosen as the experimental model considering the 3Rs of research. Hydroxyl containing benzo[b]thiophene analogs, 1-(3-hydroxybenzo[b]thiophen-2-yl) ethanone (BP) and 1-(3-hydroxybenzo[b]thiophen-2-yl) propan-1-one hydrate (EP) were injected via intraperitoneal (i.p.) route at an effective dose of 5 mg/kg one hour before the exposure of ACR (0.75 mM) for three days. ACR fish showed aberrant socio-behavior with low exploration, tight circling, negative scototaxis, disrupted aggression, and tight shoaling. These results indicated depression comorbid and anxiety-like phenotype. BP and EP partially reduced the aberrant socio-behavior. BP and EP elevated the antioxidant defense and reduced the oxidative damage in the brain caused by ACR. Cellular and tissular alterations caused by ACR were visualized through histopathological study. BP and EP administration reduced and repaired the cellular changes via the antioxidant mechanism. BP and EP altered the axonal growth and regeneration gene and synaptic vesicle cycle gene expression necessary for neurotransmission. This combined gain-of-function of redox mechanism at molecular, cellular, and tissular levels explains the behavioral improvement at the organismal level of the organization.

Alzheimer disease (AD) is a common neurodegenerative disease with an intricate pathophysiological mechanism. Oxidative stress has been shown in several investigations as a significant factor in AD progression. For instance, studies have confirmed that oxidative stress inhibition may considerably improve AD symptoms, with potent antioxidants being touted as a possible interventional strategy in the search for AD treatment. Epigallocatechin-3-gallate (EGCG) acts as a natural catechin that has antioxidant effect. It activates the kelch-like epichlorohydrin-associated proteins (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway to inhibit oxidative stress. The Keap1/Nrf2 signal pathway is not only an upstream signaling target for a variety of antioxidant enzymes, but also minimizes high levels of reactive oxygen species. This report analyzes the antioxidant effect of EGCG in AD, elaborates its specific mechanism of action, and provides a theoretical basis for its clinical application in AD.

Aberrant neurogenesis in the adult hippocampal dentate gyrus (DG) contributes to synapse remodeling during temporal lobe epilepsy (TLE). Transient receptor potential vanilloid 4 (TRPV4) is involved in the pathogenesis of TLE. Activation of TRPV4 can modulate neurogenesis in the adult hippocampal DG. The present study examined whether TRPV4 is responsible for the aberrant neurogenesis in the adult hippocampal DG during TLE. Herein, administration of a TRPV4-specific antagonist, HC-067047, attenuated the enhanced neural stem cell proliferation in the adult hippocampal DG in mice following pilocarpine‑induced status epilepticus (PISE). HC-067047 reduced the heightened hippocampal protein levels of cyclin-dependent kinase (CDK) 2, CDK6, cyclin E1, cyclin A2, and phosphorylated retinoblastoma (p-Rb) observed following PISE. Meanwhile, HC-067047 inhibited the extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (p38 MAPK) pathways that were enhanced and responsible for the increased proliferation of stem cells and higher levels of CDKs, cyclins, and p-Rb protein. HC-067047 reduced the 28-day-old BrdU⁺ cells but increased the ratio of 28-day-old BrdU⁺ cells to 1-day-old BrdU⁺ cells, indicating that TRPV4 blockage reduced the number but increased the survival rate of newborn cells following PISE. Finally, HC-067047 increased the Akt signaling that was inhibited and responsible for the decreased survival rate of newborn cells following PISE. It is concluded that TRPV4 blockage inhibits stem cell proliferation in the hippocampal DG following PISE, likely through inhibiting ERK1/2 and p38 MAPK signaling to decrease cell cycle-related protein expression, and increases newborn cell survival rate likely through increasing phosphoinositide 3 kinase-Akt signaling.