Neuronal HT22 Cells Research Articles

The role of FAM171A2-GRN-NF-κB pathway in TBBPA induced oxidative stress and inflammatory response in mouse-derived hippocampal neuronal HT22 cells

Tetrabromobisphenol A (TBBPA) is one of the brominated flame retardants (BFRs) widely used in industry, which has a broad toxic effect on organisms. However, there is still limited research on the neurotoxic mechanism of TBBPA. Using mouse hippocampal neurons (HT22) cells, the toxicity of TBBPA was evaluated, especially focusing on its alteration on the key molecules in FAM171A2-GRN-NF-κB signaling pathway. The results showed that TBBPA exposure could lead to an increase in the production of inflammation-related genes IL-6, iNOS, TGF-β1, COX2, and TNF-α in both HT22 cells and HT22-AD-model, intensifying the inflammatory response; it inhibits the mRNA expression of antioxidative enzymes genes Sod1, Cat, Gpx1, and Gsta1, resulting in reduced antioxidant enzyme activities of SOD, CAT, and GSH-Px/GPX. Mechanistically, TBBPA caused the upregulation of FAM171A2 expression level, alongside increased GRN, IκBα and p65 levels; whereas the expression of GRN, IκBα and p65 was decreased after FAM171A2 knockdown, demonstrating TBBPA-induced upregulation of FAM171A2 should be responsible for the increased GRN, IκBα and p65 expression. Therefore, for the first time, our data indicate that TBBPA-induced oxidative stress and inflammatory response is closely related to the FAM171A2-GRN-NF-κB pathway.

Suppressing ROS Production of AIE Nanoprobes by Simple Matrices Optimization for CNS Cell Observation and Minimized Influence of Cytoskeleton Morphology.

The visualization of the central nervous system (CNS) has proposed stringent criteria for fluorescent probes, as the inevitable production of reactive oxygen species (ROS) or heat generated from most photoluminescent probes upon excitation can disturb the normal status of relatively delicate CNS cells. In this work, a red-emitting fluorogen with aggregation-induced emission (AIE) characteristics, known as DTF, was chosen as the model fluorogen to investigate whether the side effects of ROS and heat could be suppressed through easy-to-operate processes. Specifically, DTF was encapsulated with different amphiphilic matrices to yield AIE nanoprobes, and their photoluminescent properties, ROS production, and photothermal conversion rates were examined. BSA@DTF NPs possessed 1.3-fold brightness compared to that of DSPE-PEG@DTF NPs and F127@DTF NPs but its ROS generation efficiency is markedly decreased to only 2.4% of that produced by F127@DTF NPs. Meanwhile, BSA@DTF NPs showed a negligible photothermal effect. These features make BSA@DTF NPs favorable for long-term live cell imaging, particularly for fluorescent imaging of CNS cells. BSA@DTF NPs were able to sustain the normal state of HT-22 neuronal cells with continuous illumination for at least 25 min, and they also preserved the cytoskeleton of microglia BV-2 cells as the untreated control group. This work represents a successful but easy-to-operate process to suppress the ROS generation of red-emissive AIEgen, and it highlights the importance of minimizing the ROS generation of the fluorescent probes, particularly in the application of long-term imaging of CNS cells.

Vitamin D can mitigate sepsis-associated neurodegeneration by inhibiting exogenous histone-induced pyroptosis and ferroptosis: Implications for brain protection and cognitive preservation

BackgroundSepsis-induced neurodegeneration and cognitive dysfunction remain critical challenges worldwide. Vitamin D was reported to reduce neuronal injury and neurotoxicity and its deficiency was associated with neurocognitive disorders. This study investigates the mechanisms by which vitamin D exerts neuroprotective potential against damage-associated molecular patterns (DAMPs), specifically extracellular histones, in sepsis-related brain dysfunction. MethodsThe cultured mouse hippocampal neuronal HT22 cells were exposed to 20 µg/ml exogenous histone for 24 h to induce pyroptosis and ferroptosis in the presence or absence of the active form of vitamin D, calcitriol (1 nM). A cecal ligation and puncture mouse sepsis model was used to evaluate histone release and pyroptosis/ferroptosis biomarkers in the brain together with neurobehavioral performance with or without calcitriol treatment (1 µg/kg, i.p. injection) at 24 h or 1 week after sepsis onset. ResultsIn vitro, histone exposure triggered both pyroptosis and ferroptosis in neuronal cells, which was significantly suppressed by calcitriol treatment with the reduced expression of caspase-1 by 38 %, GSDMD by 30 %, ACSL4 by 33 %, and the increased expression of GPX4 by 35 % (n = 6, P < 0.05). Similarly, in vivo, calcitriol treatment inhibited both neuronal pyroptosis and ferroptosis by reducing expression of pyroptosis marker, GSDMD/NeuN (11.6 ± 1.2 % vs. 19.4 ± 1.1 %) and increasing expression of ferroptosis marker, GPX4/NeuN (21.4 ± 1.7 % vs. 13.5 ± 1.1 %), in the brain of septic mice (n = 6, P < 0.01). In addition, calcitriol increased survival rate (72 % vs. 41 %) and ameliorated cognitive dysfunction of septic mice (n = 8–13, P < 0.05). ConclusionsThis study demonstrates that vitamin D exerts a neuroprotective effect against sepsis by attenuating histone-induced pyroptosis and ferroptosis. These findings highlight the potential therapeutic role of vitamin D supplementation in mitigating brain dysfunction associated with sepsis which needs for further investigation.

Ethyl Acetate Fraction of Chestnut Honey Attenuates Scopolamine-Induced Cognitive Impairment in Mice and Glutamate-Induced Neurotoxicity in HT22 Cells.

Chestnut honey has various benefits, such as antioxidative, anti-inflammatory, immunomodulatory, antibacterial, and antiviral effects. However, the effects of chestnut honey or the ethyl acetate fraction of chestnut honey (EACH) on neurodegenerative diseases and their related cognitive impairment and neurotoxicity have not yet been established. Therefore, in this study, we investigated the mitigating effect of the EACH on scopolamine (SCO)-injected cognitive decline in mice and glutamate-exposed neurotoxicity in HT22 cells. EACH administration significantly reversed SCO-induced cognitive decline in mice, as demonstrated through the Morris water maze and passive avoidance tests. The EACH treatment showed a significant alleviation effect by recovering more than 80% of the cell viability decrease induced by glutamate exposure in the HT22 neuronal cell model. Furthermore, the EACH significantly reduced reactive oxygen species accumulation, lactate dehydrogenase release, mitochondrial depolarization, and neuronal apoptosis. The EACH regulated the level of apoptosis-related proteins, induced the nuclear translocation of nuclear factor-E2-related factor 2 (Nrf-2) and the expression of related antioxidant proteins, and induced the phosphorylation of tropomyosin-related kinase receptor B (TrkB)/cAMP-calcium response element-binding protein (CREB) and the expression of brain-derived neurotrophic factor. These data indicate that the EACH can prevent neurons from oxidative damage and improve cognitive dysfunction by activating Nrf-2 and TrkB/CREB signaling pathways. Therefore, the EACH demonstrates potential therapeutic value in mitigating oxidative stress-induced neurotoxicity, cognitive decline, and related neurodegenerative diseases.

Protective effect of water-soluble nervonic acid micro-powder coated with chitosan oligosaccharide and silk fibroin on hippocampal neuronal HT22 cells

Nervonic acid (NA) is an extremely long chain monounsaturated fatty acid that plays a crucial biological role in brain development and repair. However, its low solubility reduced bioavailability and limited its applications. In this study, spherical water-soluble nervonic acid composite micro-powder (NA-WM) was constructed by layer-by-layer self-assembly technology under electrostatic interaction and hydrogen bond, in which electronegative NA was used as the core material, and electropositive COS (Chitosan oligosaccharide) with neuroprotective properties and electronegative SF (Silk fibroin) with biocompatibility and anti-inflammatory synergism were used as the wall material. In the preparation process, the electronegative NA was first combined with electropositive COS by antisolvent method, and then the electropositive COS-NA complex was encapsulated with electronegative SF to form NA-WM. The optimal preparation conditions were screened and optimized via single-factor and BBD method. Under the optimum conditions, the average particle size of NA-WM was 420 ± 35 nm. The results of TGA (Thermogravimetric), SEM (Scanning electron microscopy), and FTIR (Fourier transform infrared spectroscopy) confirmed that NA-WM had good thermal stability and spherical-defined layer-to-layer structure. Additionally, at pH 1.5, the NA release rate of NA-WM was as high as 89.54 % within 2.5 h. Through measuring the levels of MDA (Malondialdehyde), CAT (Catalase), SOD (Superoxide dismutase), GSH-Px (Glutathione peroxidase), and LDH (Lactate dehydrogenase), as well as flow cytometry and SEM analysis, it was confirmed that NA-WM could protect Aβ1–42-induced HT22 by inhibiting oxidative stress and reducing mitochondrial membrane potential. This study provided data support for the development and application of NA.

Bifidobacterium lactis-Derived Vesicles Attenuate Hippocampal Neuroinflammation by Targeting IL-33 to Regulate FoxO6/P53 Signaling.

Hippocampal Neuroinflammation (HNF) is a critical driver of cognitive impairment. The lipopolysaccharide (LPS) accumulate amyloid beta (Aβ) and lead to HNF. The Bifidobacterium lactis (BL) 99 have anti-inflammatory ability. However, whether BL99-derived microbiota-derived vesicles (MV) could alleviate LPS-induced HNF remains unclear. To investigate, we used ultrafiltration with ultracentrifuge to extract BL99-derived-MV (BL99-MV). We used hippocampal neuronal HT22 cells (HT22) to establish the LPS-induced HNF model, and explored whether BL99-MV alleviate LPS-induced HNF. The confocal microscopy showed that BL99-MV were taken up by HT22 and reduced the oxidative stress (ROS) level. The PCR showed that BL99-MV up-regulate IL-10 level, and down-regulate TNF-α, IL-1β, and IL-6. Transcriptomic analysis revealed 4127 differentially expressed genes, with 2549 genes upregulated and 1578 genes downregulated in the BL99-MV group compared to the LPS group. Compared to the LPS group, BL99-MV decreased FoxO6, IL-33, P53, and NFκB expression, but increased FoxO1 and Bcl2 expression. The WB showed that BL99-MV modulated NFκB, FoxO6, P53, Caspase9, and Caspase3 protein expression by reducing IL-33 expression in HT22. The findings demonstrated IL-33 as a regulator for FoxO6/P53 signaling. Here, we hypothesized that BL99-MV alleviated LPS-induced HNF to promote HT22 survival and synaptic development by regulating FoxO6/P53 signaling by targeting IL-33.

The involvement of lidocaine in amyloid-β1-42-dependent mitochondrial dysfunction and apoptosis in hippocampal neurons via nerve growth factor-protein kinase B pathway.

This project is conceived to reveal the role of lidocaine in the process of Alzheimer's disease (AD) and its possible downstream targets. After the employment of AD cell model in mice hippocampal neuronal HT-22 cells in the presence of amyloid-β1-42 (Aβ1-42), Cell Counting Kit-8 method investigated cell viability. Oxidative damage was assayed based on a dichloro-dihydro-fluorescein diacetate fluorescent probe and commercially available kits. The 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine iodide fluorescent probe estimated mitochondrial function. Terminal-deoxynucleotidyl transferase mediated nick end labeling, western blotting, and immunofluorescence appraised the apoptotic level. Western blot also ascertained the alternations of nerve growth factors (NGF)-protein kinase B (Akt) pathway-related proteins. Aβ1-42 concentration dependently triggered the viability loss, oxidative damage, and apoptosis in HT-22 cells. Lidocaine promoted the viability and reduced the mitochondrial impairment and mitochondria-dependent apoptosis in Aβ1-42-treated HT-22 cells in a concentration-dependent manner. Besides, lidocaine activated the NGF-Akt pathway and NGF absence blocked NGF-Akt pathway, aggravated mitochondrial dysfunction as well as mitochondria-dependent apoptosis in lidocaine-administrated HT-22 cells in response to Aβ1-42. Altogether, these observations concluded that lidocaine might stimulate NGF-Akt pathway to confer protection against mitochondrial impairment and apoptosis in Aβ1-42-mediated cellular model of AD.

Protection of HT22 neuronal cells against chemically-induced ferroptosis by catechol estrogens: protein disulfide isomerase as a mechanistic target

Ferroptosis is a form of regulated cell death, characterized by excessive iron-dependent lipid peroxidation. Biochemically, ferroptosis can be selectively induced by erastin through glutathione depletion or through inhibition of glutathione peroxidase 4 by RSL3, which leads to accumulation of cytotoxic lipid reactive oxygen species (ROS). Protein disulfide isomerase (PDI) was recently shown to mediate erastin/RSL3-induced ferroptosis and thus also become a new target for protection against chemically-induced ferroptosis. The present study aims to identify endogenous compounds that can protect against erastin/RSL3-induced ferroptotic cell death. We find that 2-hydroxyestrone, 2-hydroxyestradiol, 4-hydroxyestrone and 4-hydroxyestradiol, four major endogenous catechol estrogens, are effective inhibitors of PDI, and can strongly protect against chemically-induced ferroptotic cell death in cultured HT22 mouse hippocampal neuronal cells. The CETSA assay showed that these catechol estrogens can bind to PDI in live cells. PDI knockdown attenuates the protective effect of these catechol estrogens against chemically-induced ferroptosis. Mechanistically, inhibition of PDI’s catalytic activity by catechol estrogens abrogates erastin/RSL3-induced dimerization of nitric oxide synthase, thereby preventing the subsequent accumulation of cellular nitric oxide, ROS and lipid-ROS, and ultimately ferroptotic cell death. In addition, joint treatment of cells with catechol estrogens also abrogates erastin/RSL3-induced upregulation of nitric oxide synthase protein levels, which also contributes to the cytoprotective effect of the catechol estrogens. In conclusion, the present study demonstrates that the catechol estrogens are protectors of HT22 neuronal cells against chemically-induced ferroptosis, and inhibition of PDI’s catalytic activity by these estrogens contributes to a novel, estrogen receptor-independent mechanism of cytoprotection.

Raloxifene Prevents Chemically-Induced Ferroptotic Neuronal Death In Vitro and In Vivo.

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.

Benzofuran and Benzo[b]thiophene-2-Carboxamide Derivatives as Modulators of Amyloid Beta (Aβ42) Aggregation.

A group of N-phenylbenzofuran-2-carboxamide and N-phenylbenzo[b]thiophene-2-carboxamide derivatives were designed and synthesized as a novel class of Aβ42 aggregation modulators. In the thioflavin-T based fluorescence aggregation kinetics study, compounds 4 a, 4 b, 5 a and 5 b possessing a methoxyphenol pharmacophore were able to demonstrate concentration dependent inhibition of Aβ42 aggregation with maximum inhibition of 54 % observed for compound 4 b. In contrast, incorporation of a 4-methoxyphenyl ring in compounds 4 d and 5 d led to a significant increase in Aβ42 fibrillogenesis demonstrating their ability to accelerate Aβ42 aggregation. Compound 4 d exhibited 2.7-fold increase in Aβ42 fibrillogenesis when tested at the maximum concentration of 25 μM. These results were further confirmed by electron microscopy studies which demonstrates the ability of compounds 4 a, 4 b, 4 d, 5 a, 5 b and 5 d to modulate Aβ42 fibrillogenesis. Compounds 5 a and 5 b provided significant neuroprotection to mouse hippocampal neuronal HT22 cells against Aβ42-induced cytotoxicity. Molecular docking studies suggest that the orientation of the bicyclic aromatic rings (either benzofuran or benzo[b]thiophene) plays a major role in moderating their ability to either inhibit or accelerate Aβ42 aggregation. Our findings support the application of these novel derivatives as pharmacological tools to study the mechanisms of Aβ42 aggregation.

Innovative glycochenodeoxycholic Acid-Acrylamide Nanopolymer carriers: Regulating upper critical solution temperature on neurorehabilitation

Neurorehabilitation focuses on restoring function in patients with central and peripheral nervous system disorders, yet effective therapeutic options remain scarce. This study introduces a novel nanocopolymer, CaCO3-PAAm-GDCA, synthesized through reversible addition-fragmentation chain transfer polymerization of glycodeoxycholic acid, acrylamide, and CaCO3. This nanocopolymer exhibits a sharp and reversible insoluble-to-soluble transition in water at a temperature related to its upper critical solution temperature (UCST), which can be finely adjusted to a practical range around 37 °C, suitable for biomedical applications. The addition of β-cyclodextrin (β-CD) modulates this transition temperature by forming host-guest complexes, further enhancing the copolymer’s adaptability. When loaded with compound 1, the resulting CaCO3-PAAm-GDCA@1 significantly promoted the proliferation of damaged neuronal HT22 cells and inhibited ferroptosis through the modulation of Nrf2 and GPX4 pathways. This study provides a strong foundation for the development of neuroprotective drugs, highlighting the potential of tailored nanocopolymers in advanced neurorehabilitation therapies.

Mitofusin 2 Mediates the Protective Effect of NR6A1 Silencing Against Neuronal Injury in Experimental Stroke Models.

An abnormal increase in the expression of nuclear receptor subfamily 6 group A member 1 (NR6A1) in the hippocampus has been reported to result in depressive-like behavior in mice. However, the role of NR6A1 in the progression of neuronal death induced by ischemic stroke remains unknown. In this study, we observed an increase in NR6A1 in neurons in both in vivo and in vitro cerebral ischemic models. We found that knocking down NR6A1 in HT-22 neuronal cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) attenuated mitochondrial dysfunction and endoplasmic reticulum (ER) stress. Conversely, NR6A1 overexpression exacerbated neuronal damage following OGD/R. NR6A1 hindered the transcription of mitonfusin 2 (MFN2), leading to a decrease in its expression. In contrast, MFN2 conferred the protective effect of NR6A1 silencing against both mitochondrial dysfunction and ER stress. In addition, NR6A1 silencing also attenuated brain infarction, ER stress, neuronal apoptosis, and loss of MFN2 in mice subjected to middle cerebral artery occlusion/reperfusion. These findings indicate that NR6A1 is a promising target for the treatment of neuronal death following cerebral ischemia. Furthermore, these results confirm the involvement of MFN2 in the effects of NR6A1 silencing. Therefore, targeting NR6A1 has potential as a viable strategy for the treatment of ischemic stroke.

Tripeptide Phe-Trp-Leu-NH2 as a putative endogenous ligand of TSPO: molecular modeling, synthesis and pharmacological activity

The putative endogenous tripeptide ligand of the translocator protein (TSPO) l-phenylalanyl-l-tryptophanyl-l-leucine amide was obtained using the drug-based peptide design strategy and molecular modeling. This tripeptide demonstrated anxiolytic activity in the elevated plus-maze test and antidepressant-like activity in the forced swimming test in BALB/c mice at the doses of 10 mg kg−1 (i.p.) and also showed neuroprotective activity in the concentration range of 10−5–10−7 m in vitro under conditions of oxidative stress using HT-22 neuronal cell line.

Bis-chalcones obtained via one-pot synthesis as the anti-neurodegenerative agents and their effect on the HT-22 cell line

In the area of research on neurodegenerative diseases, the current challenge is to search for appropriate research methods that would detect these diseases at the earliest possible stage, but also new active structures that would reduce the rate of the disease progression and minimize the intensity of their symptoms experienced by the patient. The chalcones are considered in the context of candidates for new drugs dedicated to the fight against neurodegenerative diseases. The synthesis of bis-chalcone derivatives (3a-3d), as aim molecules was performed. Their structures were established by applying 1H NMR, 13C NMR, MS, FT-IR and UV–Vis spectra. All bis-chalcones were synthesized from terephthalaldehyde and appropriate aromatic ketone as substrates in the Claisen-Schmidt condensation method and evaluated in the biological tests and in silico analysis. Compounds exerted antioxidant activity using the HORAC method (3a-3d) and decreased the activities of GPx, COX-2 (3b-3d), GR (3a-3c) and CAT (3a,3b). The high anti-neurodegenerative potential of all four bis-chalcones was observed by inhibition of acetyl- (AChE) and butyrylcholinesterase (BChE) and a positive effect on the mouse hippocampal neuronal HT-22 cell line (LDH release and PGC-1α, PPARγ and GAPDH protein expression). TD-DFT method (computing a number of descriptors associated with HOMO–LUMO electron transition: electronegativity, chemical hardness and potential, first ionization potential, electron affinity) was employed to study the spectroscopic properties. This method showed that the first excited state of compounds was consistent with their maximum absorption in the computed UV–Vis spectra, which showed good agreement with the experimental spectrum using PBE1PBE functional. Using in silico approach, interactions of bis-chalcones with selected targets (aryl hydrocarbon receptor (AhR) PAS-A Domain, ligand binding domain of human PPAR-γ, soman-aged human BChE-butyrylthiocholine complex, Torpedo californica AChE:N-piperidinopropyl-galanthamine complex and the COX-2-celecoxib complex) were characterized. Results obtained in in silico models were consistent with in vitro experiments.

Ionic liquid and ultrasound as a fast and innovative combination for improved extraction of Chlorella sorokiniana-derived carotenoids

Chlorella sorokiniana is a microalgae with high amounts of carotenoids, but the extraction methods need to be improved. This work hypothesized that the combination of ionic liquids (ILs) and ultrasound would provide a fast and efficient process for carotenoid extraction, allowing for the reuse of ILs in several extractive cycles. This study aimed to develop an improved ILs/ultrasound-based method for extracting carotenoids from C. sorokiniana. The potential reuse of ILs in five consecutive extraction cycles and the recovery of carotenoids was also examined. Moreover, the antioxidant activity of the carotenoid extracts and their effects on metabolic cell viability and cell death were investigated using HT22 neuronal cells. Initial tests with four ILs and acetone as a control were carried out in an ultrasonic probe. The ILs (1-butyl-3-methylimidazolium chloride [BMIM][Cl]; 1-hexyl-3-methylimidazolium chloride [HMIM][Cl]) were selected for the 25−1 fractional experimental design. The maximized parameters obtained in the experimental design were the following: IL ([HMIM][Cl]), a 1:10 solid-liquid ratio, a 1:4 IL-cosolvent ratio, and two repetitions of extraction with 7.5 min (with an extraction yield of 1.29 mg·g‐1 of dry matter). A total of 11 carotenoids were separated, and nine were identified, the major ones being lutein and β-carotene. [HMIM][Cl] recyclability using resin Amberlite XAD-7HP was efficient for at least five cycles. On average, 91 % of the IL was recovered, and the pigment yield increased by 40 %. The antioxidant activities of the extracts obtained using [HMIM][Cl] and acetone were 1.65 μmol and 2.32 μmol of α-tocopherol, respectively. Both extracts (≤ 4.0 μg·mL‐1) exhibited no significant toxicity to HT22 cells. The proposed method is an innovative and improved approach for carotenoid extraction from C. sorokiniana due to its short extraction times and high process yield. [HMIM][Cl] demonstrated stability in reuse cycles and proved to have the potential for obtaining carotenoids from C. sorokiniana.

Small molecule inhibitor DDQ-treated hippocampal neuronal cells show improved neurite outgrowth and synaptic branching.

JOURNAL/nrgr/04.03/01300535-202509000-00024/figure1/v/2024-11-05T132919Z/r/image-tiff The process of neurite outgrowth and branching is a crucial aspect of neuronal development and regeneration. Axons and dendrites, sometimes referred to as neurites, are extensions of a neuron's cellular body that are used to start networks. Here we explored the effects of diethyl (3,4-dihydroxyphenethylamino)(quinolin-4-yl) methylphosphonate (DDQ) on neurite developmental features in HT22 neuronal cells. In this work, we examined the protective effects of DDQ on neuronal processes and synaptic outgrowth in differentiated HT22 cells expressing mutant Tau (mTau) cDNA. To investigate DDQ characteristics, cell viability, biochemical, molecular, western blotting, and immunocytochemistry were used. Neurite outgrowth is evaluated through the segmentation and measurement of neural processes. These neural processes can be seen and measured with a fluorescence microscope by manually tracing and measuring the length of the neurite growth. These neuronal processes can be observed and quantified with a fluorescent microscope by manually tracing and measuring the length of the neuronal HT22. DDQ-treated mTau-HT22 cells (HT22 cells transfected with cDNA mutant Tau) were seen to display increased levels of synaptophysin, MAP-2, and β-tubulin. Additionally, we confirmed and noted reduced levels of both total and p-Tau, as well as elevated levels of microtubule-associated protein 2, β-tubulin, synaptophysin, vesicular acetylcholine transporter, and the mitochondrial biogenesis protein-peroxisome proliferator-activated receptor-gamma coactivator-1α. In mTau-expressed HT22 neurons, we observed DDQ enhanced the neurite characteristics and improved neurite development through increased synaptic outgrowth. Our findings conclude that mTau-HT22 (Alzheimer's disease) cells treated with DDQ have functional neurite developmental characteristics. The key finding is that, in mTau-HT22 cells, DDQ preserves neuronal structure and may even enhance nerve development function with mTau inhibition.

MiR-18a affects hypoxia induced glucose metabolism transition in HT22 hippocampal neuronal cell line through the Hif1a gene

Hypoxia can cause a variety of diseases, including ischemic stroke and neurodegenerative diseases. Within a certain range of partial pressure of oxygen, cells can respond to changes in oxygen. Changes in oxygen concentration beyond a threshold will cause damage or even necrosis of tissues and organs, especially for the central nervous system. Therefore, it is very important to find appropriate measures to alleviate damage. MiRNAs can participate in the regulation of hypoxic responses in various types of cells. MiRNAs are involved in regulating hypoxic responses in many types of tissues by activating the hypoxia-inducible factor (HIF) to affect angiogenesis, glycolysis and other biological processes. By analyzing differentially expressed miRNAs in hypoxia and hypoxia-related studies, as well as the HT22 neuronal cell line under hypoxic stress, we found that the expression of miR-18a was changed in these models. MiR-18a could regulate glucose metabolism in HT22 cells under hypoxic stress by directly regulating the 3’UTR of the Hif1a gene. As a small molecule, miRNAs are easy to be designed into small nucleic acid drugs, so this study can provide a theoretical basis for the research and treatment of nervous system diseases caused by hypoxia.Graphical

Phelligridimer A enhances the expression of mitofusin 2 and protects against cerebral ischemia/reperfusion injury

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress play pivotal roles in the pathology of cerebral ischemia. In this study, we investigated whether phelligridimer A (PA), an active compound isolated from the medicinal and edible fungus Phellinus igniarius, ameliorates ischemic cerebral injury by restoring mitochondrial function and restricting ER stress. An in vitro cellular model of ischemic stroke-induced neuronal damage was established by exposing HT-22 neuronal cells to oxygen-glucose deprivation/reoxygenation (OGD/R). An in vivo animal model was established in rats subjected to middle cerebral artery occlusion/reperfusion (MCAO/R). The results showed that PA (1–10 μM) dose-dependently increased HT-22 cell viability, reduced OGD/R-induced lactate dehydrogenase release, and reversed OGD/R-induced apoptosis. PA reduced OGD/R-induced accumulation of reactive oxygen species, restored mitochondrial membrane potential, and increased ATP levels. Additionally, PA reduced the expression of the 78-kDa glucose-regulated protein (GRP78) and the phosphorylation of inositol-requiring enzyme-1α (p-IRE1α) and eukaryotic translation-initiation factor 2α (p-eIF2α). PA also inhibited the activation of the mitogen-activated protein kinase (MAPK) pathway in the OGD/R model. Moreover, treatment with PA restored the expression of mitofusin 2 (Mfn-2), a protein linking mitochondria and ER. The silencing of Mfn-2 abolished the protective effects of PA. The results from the animal study showed that PA (3–10 mg/kg) significantly reduced the volume of cerebral infarction and neurological deficits, which were accompanied by an increased level of Mfn-2, and decreased activation of the ER stress in the penumbra of the ipsilateral side after MCAO/R in rats. Taken together, these results indicate that PA counteracts cerebral ischemia-induced injury by restoring mitochondrial function and reducing ER stress. Therefore, PA might be a novel protective agent to prevent ischemia stroke-induced neuronal injury.

Synthesis, structural characterization and cytoprotective activity of a new mixed oxidovanadium(IV) compound with nitrilotriacetate and imidazole ligands

Herein, we have shown that the water molecule in [VO(nta)(H2O)]- can be replaced by an imidazole moiety which is a versatile binding site in various biological systems. These findings offer a new approach for synthesizing mixed ligand complexes with desired physicochemical and biological properties. In this study, a new hetero-ligand oxidovanadium(IV) monohydrate salt was successfully synthesized and structurally characterized. The compound consists of a mononuclear [VO(nta)(im)]- entity, where nitrilotriacetato–(nta) and imidazole (im) ligands are incorporated, along with an imidazolinium counterion, [im(H)][VO(nta)(im)]H2O. To characterize the complex in a solid state, various techniques were employed including elemental analysis, thermogravimetric analysis (TG-FTIR), single-crystal X-ray diffraction method and IR spectroscopy. In addition, the investigation included a study of the speciation of the complex ion [VO(nta)(im)]- in an aqueous solution. Furthermore, the influence of imidazole as an auxiliary ligand (im) in the coordination sphere of V(IV) is investigated in terms of its effects on ABTS+• radical scavenging activity and cytoprotective properties against oxidative damage in the hippocampal neuronal HT22 cell line. Finally, this study compares and discusses the physicochemical properties and biological activities of the newly synthesised compound and those containing [VO(nta)(H2O)]- complex anions.

Polydopamine-Coated Kaempferol-Loaded MOF Nanoparticles: A Novel Therapeutic Strategy for Postoperative Neurocognitive Disorder.

The primary objective of this study was to develop an innovative nanomedicine-based therapeutic strategy to alleviate Postoperative Neurocognitive Disorder (PND) in patients undergoing surgery. To achieve this goal, polydopamine-coated Kaempferol-loaded Metal-Organic Framework nanoparticles (pDA/KAE@ZIF-8) were synthesized and evaluated. The study involved encapsulating Kaempferol (KAE) within ZIF-8 nanoparticles, followed by coating with polydopamine (PDA) to enhance biocompatibility and targeted delivery. The characterization of these nanoparticles (NPs) was conducted using various techniques including Scanning Electron Microscopy, Fourier-Transform Infrared Spectroscopy, X-ray Diffraction, and Ultraviolet-Visible spectroscopy. The efficacy of pDA/KAE@ZIF-8 NPs was tested in both in vitro and in vivo models, specifically focusing on their ability to penetrate the blood-brain barrier and protect neuronal cells against oxidative stress. The study found that pDA/KAE@ZIF-8 NPs efficiently penetrated the blood-brain barrier and were significantly taken up by neuronal cells. These nanoparticles demonstrated remarkable Reactive Oxygen Species (ROS) scavenging capabilities and stability under physiological conditions. In vitro studies showed that pDA/KAE@ZIF-8 NPs provided protection to HT-22 neuronal cells against H2O2-induced oxidative stress, reduced the levels of pro-inflammatory cytokines, and decreased apoptosis rates. In a PND mouse model, the treatment with pDA/KAE@ZIF-8 NPs significantly improved cognitive functions, surpassing the effects of KAE alone. This improvement was substantiated through behavioral tests and a noted reduction in hippocampal inflammation. The findings from this study underscore the potential of pDA/KAE@ZIF-8 NPs as an effective nanotherapeutic agent for PND. This approach offers a novel direction in the postoperative care of elderly patients, with the potential to transform the therapeutic landscape for neurocognitive disorders following surgery. The application of nanotechnology in this context opens new avenues for more effective and targeted treatments, thereby improving the quality of life for patients suffering from PND.