PC12 Cells Research Articles

Autocrine activation of P2X7 receptors mediates catecholamine secretion in chromaffin cells.

ATP is highly accumulated in secretory vesicles and secreted upon exocytosis from neurons and endocrine cells. In adrenal chromaffin granules, intraluminal ATP reaches concentrations over 100 mM. However, how these large amounts of ATP contribute to exocytosis has not been investigated. Exocytotic events in bovine and mouse adrenal chromaffin cells were measured with single cell amperometry. Cytosolic Ca2+ measurements were carried out in Fluo-4 loaded cells. Submembrane Ca2+ was examined in PC12 cells transfected with a membrane-tethered Ca2+ indicator Lck-GCaMP3. ATP release was measured using the luciferin/luciferase assay. Knockdown of P2X7 receptors was induced with short interfering RNA (siRNA). Direct Ca2+ influx through this receptor was measured using a P2X7 receptor-GCamp6 construct. ATP induced exocytosis in chromaffin cells, whereas the ectonucleotidase apyrase reduced the release events induced by the nicotinic agonist dimethylphenylpiperazinium (DMPP), high KCl, or ionomycin. The purinergic agonist BzATP also promoted a secretory response that was dependent on extracellular Ca2+. A740003, a P2X7 receptor antagonist, abolished secretory responses of these secretagogues. Exocytosis was also diminished in chromaffin cells when P2X7 receptors were silenced using siRNAs and in cells of P2X7 receptor knockout mice. In PC12 cells, DMPP induced ATP release, triggering Ca2+ influx through P2X7 receptors. Furthermore, BzATP, DMPP, and KCl allowed the formation of submembrane Ca2+ microdomains inhibited by A740003. Autocrine activation of P2X7 receptors constitutes a crucial feedback system that amplifies the secretion of catecholamines in chromaffin cells by favouring submembrane Ca2+ microdomains.

Dihydroquercetin regulates HIF-1α/AKT/NR2B signalling to improve impaired brain function in rats with metabolic syndrome

Dihydroquercetin (DHQ) is commonly used as a dietary additive, but its activity in improving brain injury with metabolic syndrome (MS) remains known. In present study, the MS rat model was induced using 10 % fructose water. The apoptosis rate of primary brain cells was detected. The HIF-1α/AKT/NR2B signalling pathway, levels of KEAP1/NRF2, HO-1 and NQO-1 were detected. In vitro experiments were performed using H2O2-stimulated PC-12 cells. The effect of DHQ on rates of cell survival and apoptosis were detected. After silencing HIF-1α, we further elucidate the mechanism of action of DHQ. The results indicated that DHQ reduced the hyperactivity and inhibited oxidative stress via increasing the levels of HIF-1α/AKT/NR2B signalling pathway, whereas regulated KEAP1/NRF2 pathway. In vitro experiments showed that the HIF-1α plays an important role in this process. Overall, DHQ may improve impaired brain function in rats with metabolic syndrome by regulating the HIF-1α/AKT/NR2B signalling pathway.

A Sequentially Activated Probe for Imaging of Superoxide Anion and Peroxynitrite in PC12 Cells under Oxidative Stress.

Superoxide anion (O2·-) and peroxynitrite (ONOO-), two important oxidants under oxidative stress, coexist in complex cell and organism systems, playing crucial roles in various physiological and pathological processes, particularly in neurodegenerative diseases. Despite the absence of robust molecular tools capable of simultaneously visualizing O2·- and ONOO- in biosystems, the relationship between these two species remains understudied. Herein, we present sequentially activated fluorescent probe, DHX-SP, which exhibits exceptional selectivity and sensitivity toward O2·- and ONOO-. This probe enables precise imaging of these species in living PC12 cells under oxidative stress conditions using distinct fluorescence signal combinations. Furthermore, the probe DHX-SP has the ability to visualize changes in O2·- and ONOO- levels during ferroptosis of PC12 cells and in the Parkinson's disease model. These findings establish a connection between the crosstalk of the phosphorus group of O2·- and ONOO- in PC12 cells under oxidative stress.

Ecdysterone improves oxidative damage induced by acute ischemic stroke via inhibiting ferroptosis in neurons through ACSL4

Ethnopharmacological relevanceAcute ischemic stroke (AIS) is a prominent cause of disability and mortality around the world. Achyranthes bidentata Blume, a regularly prescribed traditional Chinese herb, plays a significant role in traditional Chinese stroke therapy due to its ability to promote blood circulation and remove stasis. Ecdysterone (EDS) is one of the key active components in Achyranthes bidentata Blume, which exhibits antioxidant and anti-cerebral hypoxia properties. However, whether EDS improves AIS and the mechanism of action of AIS is still unclear. Aim of the studyThe objective of this study was to observe whether EDS ameliorates oxidative damage caused by AIS by inhibiting ferroptosis in neurons via ACSL4. Materials and methodsIn vivo, the Middle cerebral artery occlusion (MCAO) rat model was established for research. After treatment with EDS, Neurologic score, TTC, HE and FJC staining were performed, followed by measurements of oxidative stress-related indicators, the content of Fe2+, iron deposition levels and expression of ACSL4, NCOA4 and FTH1 in brain tissue. In vitro, oxygen-glucose deprivation and reperfusion (OGD/R) cell model was established. After treatment with EDS, cell viability, oxidative stress-related indicators, the content of Fe2+ and expression of ACSL4, NCOA4 and FTH1 were detected. In addition, the overexpression of ACSL4 and CETSA technology further elucidated that EDS improves AIS through ACSL4. ResultsThe results showed that the treatment of EDS could improve the oxidative damage of MCAO rats by inhibiting ferroptosis, and then improve AIS. Importantly, EDS inhibited ferroptosis via ACSL4, thereby inhibiting oxidative stress in MCAO rats or OGD/R-induced PC12 cells. ConclusionsThese results provide evidence that EDS ameliorates oxidative damage caused by AIS by inhibiting ferroptosis via ACSL4, and provide new insights into the potential use of EDS as an effective drug development candidate for AIS.

Synthesis of zinc oxide nanoparticles via biomass of Hypnea pannosa as a green mediator and their biological applications

The biological manufacturing of zinc oxide nanoparticles (ZnO-NPs) using renewable sources is safe, harmless, and compatible with the environment. The capacity of Hypnea pannosa to synthesize ZnO-NPs was investigated in this work. Ultraviolet visible (UV-Vis) spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), and zeta potential analysis were employed to characterize the ZnO-NPs. The created ZnO-NPs showed antimicrobial activity against Staphylococcus aureus, Enterococcus faecalis, Klebsiella pneumoniae, Acinetobacter baumannii, Candida albicans, and Candida auris. ZnO-NPs showed an MIC of 12.5 µg/mL against S. aureus, E. faecalis, K. pneumoniae, C. albicans, and C. auris, but it had a 25 µg/mL against Acinetobacter baumannii. ZnO-NPs’ ability to scavenge free radicals was assessed using the 1,1-diphenyl-2-picryl hydrazyl (DPPH) technique with IC50 of 36.2 µg/mL. Anti-inflammatory activity of ZnO-NPs compared to indomethacin at 1000 µg/mL was investigated, where the membrane’s maximum stabilizer was 93.3%. ZnO-NPs demonstrated anticancer activity against PC3 and Caco2 cell lines with IC50 of 174.3 μg/mL and 83.3 μg/mL, respectively. Furthermore, ZnO-NPs demonstrated a range of anti-biofilm activities against Pseudomonas aeruginosa and Staphylococcus aureus. Furthermore, ZnO-NPs showed encouraging antiviral effect versus COX B4 as well as HSV1 with antiviral activities of 54.8% and 61.1%, respectively.

Triphenyltin(IV) compounds bearing modulated azo-carboxylato ligands: Synthesis, structural characterization, in vitro cytotoxicity, BSA/DNA binding affinity, and in silico studies

Three novel triphenyltin(IV) compounds with modulated azo-carboxylato ligands: triphenylstannyl (E)-4-((2-hydroxynaphthalen-1-yl)diazenyl)benzoate, 1, triphenylstannyl (E)-4-((4-hydroxyphenyl)diazenyl)benzoate, 2, and triphenylstannyl (E)-4-((4-(dimethylamino)phenyl)diazenyl)benzoate, 3, were synthesized and characterized by elemental analysis, FTIR and NMR (1H, 13C, 119Sn) spectroscopy. The structures and spectra of compounds were predicted by Density Functional Theory (DFT) methods at B3LYP-D3BJ/6–311++G(d,p)(H,C,N,O)/LanL2DZ(Sn) level of theory. Furthermore, the antitumor potential of ligand precursors, HL1–HL3, and appropriate organotin(IV) compounds 1–3 was evaluated across mouse melanoma B16F1, human breast adenocarcinoma MCF-7, human colorectal HT-29 and human prostate PC3 cell lines using MTT and CV assays. The organotin(IV) compounds exhibit enhanced cellular uptake and efficacy in reducing viable cell numbers when compared to free acids. Specifically, compound 3 demonstrates a notable impact at lower nanomolar concentrations on all tested cell lines. Moreover, 3 induces cell death in MCF-7 cells by inhibiting cell division and promoting the overproduction of cellular nitric oxide (NO), ultimately leading to caspase-independent apoptosis. Importantly, this process occurs without concurrent activation of autophagy or the generation of ROS/RNS species. The binding affinity of 1–3 with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) was investigated by fluorescence spectroscopy and molecular docking simulations, suggesting their capacity to interact with these biomolecules.

Neuroprotective effect of acetoxypachydiol against oxidative stress through activation of the Keap1-Nrf2/HO-1 pathway

BackgroundExcessive oxidative stress in the brain is an important pathological factor in neurological diseases. Acetoxypachydiol (APHD) is a lipophilic germacrane-type diterpene extracted as a major component from different species of brown algae within the genus Dictyota. There have been no previous reports on the pharmacological activity of APHD. The present research aims to explore the potential neuroprotective properties of APHD and its underlying mechanisms.MethodsThe possible mechanism of APHD was predicted using a combination of molecular docking and network pharmacological analysis. PC12 cells were induced by H2O2 and oxygen–glucose deprivation/reoxygenation (OGD/R), respectively. Western blot, flow cytometry, immunofluorescence staining, and qRT-PCR were used to investigate the antioxidant activity of APHD. The HO-1 inhibitor ZnPP and Nrf2 gene silencing were employed to confirm the influence of APHD on the signaling cascade involving HO-1, Nrf2, and Keap1 in vitro.ResultsAPHD exhibited antioxidant activity in both PC12 cells subjected to H2O2 and OGD/R conditions by downregulating the release of LDH, the concentrations of MDA, and ROS, and upregulating SOD, GSH-Px, and GSH concentrations. APHD could potentially initiate the Keap1-Nrf2/HO-1 signaling cascade, according to the findings from network pharmacology evaluation and molecular docking. Furthermore, APHD was observed to increase Nrf2 and HO-1 expression at both mRNA and protein levels, while downregulating the protein concentrations of Keap1. Both Nrf2 silencing and treatment with ZnPP reversed the neuroprotective effects of APHD.ConclusionsAPHD activated antioxidant enzymes and downregulated the levels of LDH, MDA, and ROS in two cell models. The neuroprotective effect is presumably reliant on upregulation of the Keap1-Nrf2/HO-1 pathway. Taken together, APHD from brown algae of the genus Dictyota shows potential as a candidate for novel neuroprotective agents.

Protection of Si Nanowires against Aβ Toxicity by the Inhibition of Aβ Aggregation.

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by the accumulation of amyloid beta (Aβ) plaques in the brain. Aβ1-42 is the main component of Aβ plaque, which is toxic to neuronal cells. Si nanowires (Si NWs) have the advantages of small particle size, high specific surface area, and good biocompatibility, and have potential application prospects in suppressing Aβ aggregation. In this study, we employed the vapor-liquid-solid (VLS) growth mechanism to grow Si NWs using Au nanoparticles as catalysts in a plasma-enhanced chemical vapor deposition (PECVD) system. Subsequently, these Si NWs were transferred to a phosphoric acid buffer solution (PBS). We found that Si NWs significantly reduced cell death in PC12 cells (rat adrenal pheochromocytoma cells) induced by Aβ1-42 oligomers via double staining with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and fluorescein diacetate/propyl iodide (FDA/PI). Most importantly, pre-incubated Si NWs largely prevented Aβ1-42 oligomer-induced PC12 cell death, suggesting that Si NWs exerts an anti-Aβ neuroprotective effect by inhibiting Aβ aggregation. The analysis of Fourier Transform Infrared (FTIR) results demonstrates that Si NWs reduce the toxicity of fibrils and oligomers by intervening in the formation of β-sheet structures, thereby protecting the viability of nerve cells. Our findings suggest that Si NWs may be a potential therapeutic agent for AD by protecting neuronal cells from the toxicity of Aβ1-42.

Design, Synthesis, and Biological Evaluation of Novel Cinnamide Derivatives as Neuroprotective Agents for the Treatment of Cerebral Ischemia.

Ischemic stroke, the most common type of cerebrovascular accident, is a major cause of severe disability among adults worldwide. Although there has been progress in interventions for ischemic stroke in the past decades, there is no effective treatment to prevent brain damage in acute ischemic stroke. Therefore, it is urgent to develop novel neuroprotective agents with a wide therapeutic time window to provide a better prognosis for ischemic stroke patients. The current study aimed to synthesize novel derivatives with substituent cinnamide scaffolds, evaluate biological activity, and obtain neuroprotective agents. The target compounds were synthesized using classical methods of medicinal chemistry. The neuroprotective effects in vitro against Glu-induced neurotoxicity injury were evaluated in PC12 cells by MTT assay. The cell apoptosis was analyzed by flow cytometer. The proteins were detected by western blotting. The neuroprotective activities in vivo were determined in two in vivo models of global and focal cerebral ischemia. Among the title compounds, 9t, 9u, 9y, and 9z exhibited good neuroprotection in vivo and in vitro, which were selected and further studied to determine their mechanism of action. 9t, 9u, 9y and 9z protected PC12 cells against glutamate-induced apoptosis in a dose-dependent manner via caspase-3 pathway. Moreover, the four compounds significantly reduced brain infarct area and exhibited excellent neuroprotective activities in the in vivo MCAO model. Compounds 9t, 9u, 9y, and 9z, as potent neuroprotective agents with anti- neurotoxicity activity in vitro and anticerebral infarction efficacy in vivo, might serve as a useful molecular tool for further physiology and pathophysiology function studies, leading to potential clinical therapeutic agents for ischemic injury.

Computational Design of Novel Cyclic Peptides Endowed with Autophagy-Inhibiting Activity on Cancer Cell Lines.

(1) Autophagy plays a significant role in development and cell proliferation. This process is mainly accomplished by the LC3 protein, which, after maturation, builds the nascent autophagosomes. The inhibition of LC3 maturation results in the interference of autophagy activation. (2) In this study, starting from the structure of a known LC3B binder (LIR2-RavZ peptide), we identified new LC3B ligands by applying an in silico drug design strategy. The most promising peptides were synthesized, biophysically assayed, and biologically evaluated to ascertain their potential antiproliferative activity on five humans cell lines. (3) A cyclic peptide (named Pep6), endowed with high conformational stability (due to the presence of a disulfide bridge), displayed a Kd value on LC3B in the nanomolar range. Assays accomplished on PC3, MCF-7, and A549 cancer cell lines proved that Pep6 exhibited cytotoxic effects comparable to those of the peptide LIR2-RavZ, a reference LC3B ligand. Furthermore, it was ineffective on both normal prostatic epithelium PNT2 and autophagy-defective prostate cancer DU145 cells. (4) Pep6 can be considered a new autophagy inhibitor that can be employed as a pharmacological tool or even as a template for the rational design of new small molecules endowed with autophagy inhibitory activity.

Multiple Fano resonator based on photonic crystal waveguide coupled with two micro-cavities for biomedical sensing application

In order to acquire a miniature refractive index (RI) biosensor with high sensitivity, fast and selective for ultra-low concentrations of molecules, a new Photonic Crystal (PhC) biosensor based on a waveguide coupled to a Fano resonator is proposed for cancer cells detection. An optimized structure of the biosensor can detect cells cancers (Besal, Hela, Jurkat and PC12) in a biological solution deposited on the surface of the resonator. The detection mechanism uses the refractive index as a detection element. The performance of the proposed biosensor is studied by analyzing the variations in the transmission spectrum of different normal and cancer cells. The proposed structure is multimode PhC, with silica as a dielectric material. The finite element method (FEM) have been implemented for studying and investigating the numerical values. The simulation results display that the proposed biosensor attains spectral sensitivities of ‘513.12 nm RIU−1’, ‘587.28 nm RIU−1 ’, ‘702.35 nm RIU−1 ’ and ‘690.57 nm RIU−1 ’ corresponding to Hela cells, PC12 cells, Basal cells and Jurkat cells, respectively. And he qualilty factor Q of the Fano resonance mode can reach 3040.26. Our optimized design ensures easy fabrication with ongoing techniques. This study may open a new way for the development of integrated optical circuits and biosensing.

Natural products from Odontonema strictum promote neurite outgrowth in neuronal PC12 cells

The leaves of Odontonema strictum, a tropical plant used for its antihypertensive properties, are rich in nutrients and biologically active phytochemicals, such as β-sitosterol, stigmasterol, umuravumbolide, deacetylumuravumbolide, dideacetylboronolide, deacetylboronolide, verbascoside, and isoverbascoside. In addition, its roots are rich in β-sitosterol, stigmasterol, and the iridoid glycoside β-O-methyl-unedoside. Ingestion of the roots was reported to have a sedative effect in a dog was previously reported on a dog eating the roots of this plant. In the present study, we report for the first time the cell proliferation- and neurite outgrowth-promoting effects in PC12 neuronal cells of the isolated organic compounds and crude extracts from O. strictum. Pituitary adenylate cyclase-activating peptide (PACAP) and quercetin were used as positive controls. At the concentration of 0.2 μg/mL, β-sitosterol was more potent than quercetin and displayed the same activity (>45 μm/cell) as PACAP (100 nM). At a low concentration (0.04 μg/mL), verbascoside and isoverbascoside showed the strongest neurite outgrowth-promoting effect (neurite length of 30 to 35 μm/cell). Our results indicate that phytomedicines made from O. strictum may be useful in preventing neurodegenerative diseases.

MiR-497-5p ameliorates the oxyhemoglobin-induced subarachnoid hemorrhage injury in vitro by targeting orthodenticle homeobox protein 1 (Otx1) to activate the Nrf2/HO-1 pathway.

Subarachnoid hemorrhage (SAH) is a neurological disorder that severely damages the brain and causes cognitive impairment. MicroRNAs are critical regulators in a variety of neurological diseases. MiR-497-5p has been found to be downregulated in the aneurysm vessel walls obtained from patients with aneurysmal subarachnoid hemorrhage, but its functions and mechanisms in SAH have not been reported. Therefore, this study was designed to investigate the effect of miR-497-5p and its related mechanisms in SAH. We established an in vitro SAH model by exposing PC12 cells to oxyhemoglobin (oxyHb). We found that miR-497-5p was downregulated in SAH serum and oxyHb-treated PC12 cells, and its overexpression inhibited the oxyHb-induced apoptosis, inflammatory response and oxidative stress via activation of the Nrf2 pathway. Mechanistically, the targeting relationship between miR-497-5p and Otx1 was verified by luciferase reporter assays. Moreover, Otx1 upregulation abolished the protective effects of miR-497-5p upregulation against oxyHb-induced apoptosis, inflammation and oxidative stress in PC12 cells. Collectively, our findings indicate that miR-497-5p could inhibit the oxyHb-induced SAH damage by targeting Otx1 to activate the Nrf2/HO-1 pathway, which provides a potential therapeutic target for SAH treatment.

LncRNA NEAT1 promotes MPP+ induced injury of PC12 cells and accelerates the progression of Parkinson's disease in mice through FUS mediated inhibition of PI3K/AKT/mTOR signalling pathway

Long noncoding RNA nuclear-enriched abundant transcript 1 (NEAT1) is involved in the progression of Parkinson's disease (PD), but the specific regulatory role needs further exploration. This study showed that the expression of NEAT1 was upregulated in the cerebrospinal fluid (CSF) and peripheral blood of patients with different stages of PD. 1-Methyl-4-phenylpyridine (MPP)-treated PC 12 cells were transfected with si-NEAT1, and MPP treatment promoted cell apoptosis, oxidative stress and inflammatory factor secretion. Si-NEAT1 reversed the effects of MPP. NEAT1 silencing eliminated the effect of MPP on the protein expression levels of LC3-II and p62/SQSTM1. By using an online bioinformatics database, Fused in Sarcoma (FUS) was confirmed to be an RNA binding protein of NEAT1, and it was highly expressed in the CSF and peripheral blood of patients with PD. Si-FUS was transfected into MPP-treated PC 12 cells to detect cell apoptosis, oxidative stress, inflammatory factor secretion and autophagy, and the results were the same as those of transfection of si-NEAT1. Furthermore, MPP treatment reduced the phosphorylation levels of PI3K, Akt and mTOR, whereas si-FUS reversed the effects of MPP. In vivo, compared with the model group, the PD mice showed reduced NEAT1 and FUS expression levels and activated PI3K pathway after being injected with si-NEAT1. The brain tissue of NEAT1-silenced PD mice had decreased inflammatory infiltration and apoptosis and increased neurological scores. In conclusion, NEAT1 is involved in PD progression through FUS-mediated inhibition of the PI3K/AKT/mTOR signalling pathway.

Lycium barbarum polysaccharides attenuate nonylphenol and octylphenol-induced oxidative stress and neurotransmitter disorders in PC-12 cells

Nonylphenol (NP) and octylphenol (OP) are environmental contaminants with potential endocrine disrupting effects. However, there is limited research on the mechanisms and intervention of combined NP and OP exposure-induced neurotoxicity. This study aims to explore the cytotoxicity of combined NP and OP exposure and evaluate the potential of Lycium barbarum polysaccharides (LBP) in mitigating the aforementioned toxicity. In present study, LBP (62.5, 125 and 250 µg/mL) were applied to intervene rat adrenal pheochromocytoma (PC-12) cells treated with combined NP and OP (NP: OP = 4:1, w/w; 1, 2, 4 and 8 µg/mL). The results showed that NP and OP induced oxidative stress, disrupted the 5-hydroxytryptamine (5-HT) and cholinergic systems in PC-12 cells. Additionally, they activated the p38 protein kinase (p38) and suppressed the expression of silent information regulation type 1 (SIRT1), monoamine oxidase A (MAOA), phosphorylated cyclic-AMP response binding protein (p-CREB), brain-derived neurotrophic factor (BDNF) and phosphorylated tropomyosin-related kinase receptor type B (p-TrkB). However, N-acetyl-L-cysteine (NAC) treatment counteracted the changes of signalling molecule p38, SIRT1/MAOA and CREB/BDNF/TrkB pathways-related proteins induced by NP and OP. LBP pretreatment ameliorated combined NP and OP exposure-induced oxidative stress and neurotransmitter imbalances. Furthermore, the application of LBP and administration of a p38 inhibitor both reversed the alterations in the signaling molecule p38, as well as the proteins associated to the SIRT1/MAOA and CREB/BDNF/TrkB pathways. These results implied that LBP may have neuroprotective effects via p38-mediated SIRT1/MAOA and CREB/BDNF/TrkB pathways.

Core/shell nanofibrous conduit containing natural surfactant enhanced axonal regrowth guiding for peripheral nerve regeneration

This study illustrated the impact of Saponins in electrospun nanofibers on nerve regeneration and compared them with Tween 80, which is commonly used as a synthetic surfactant. The study explores the effect of Saponins, natural emulsifiers known for their effectiveness in forming and stabilizing emulsions. Surfactant choice is crucial due to its effects on fluid stability, influenced by parameters like polymer concentration, homogenization rate, and surfactant type/amount. This study explored PCL as the core and PVA as the shell.Core/shell scaffolds displayed favorable wettability (contact angle: 67.0° ± 1.3) and improved mechanical properties (wet state tensile strength: PVA 1.1 ± 0.2 MPa, PVA/PCL-Saponin 2.0 ± 0.5 MPa). The MTT viability assay demonstrated higher viability of PC12 cells on Saponin-containing nanofibers (85.0 % ± 0.1) compared to Tween 80 (69.0 % ± 0.1) after 24 h. Subcutaneous implantation in rats showed no significant inflammation after one week. Eventually, in the animal model, the conduit containing Saponin was more effective than Tween 80 in repairing the rat's sciatic nerve within six weeks, as evidenced by NF-200 counts and histological studies. Overall, the study indicates that PVA/PCL-Saponin nanofibers, without requiring Saponin surfactant removal, show high quality and effectiveness for tissue engineering and medical purposes.

PGC-1a mediated mitochondrial biogenesis promotes recovery and survival of neuronal cells from cellular degeneration.

Neurodegenerative disorders are characterized by the progressive loss of structure and function of neurons, often including the death of the neuron. Previously, we reported that, by removing the cell death stimulus, dying/injured neurons could survive and recover from the process of regulated cell death, even if the cells already displayed various signs of cellular damage. Now we investigated the role of mitochondrial dynamics (fission/fusion, biogenesis, mitophagy) in both degeneration and in recovery of neuronal cells. In neuronal PC12 cells, exposure to ethanol (EtOH) induced massive neurite loss along with widespread mitochondrial fragmentation, mitochondrial membrane potential loss, reduced ATP production, and decreased total mitochondrial volume. By removing EtOH timely all these mitochondrial parameters recovered to normal levels. Meanwhile, cells regrew neurites and survived. Study of the mitochondrial dynamics showed that autophagy was activated only during the cellular degeneration phase (EtOH treatment) but not in the recovery phase (EtOH removed), and it was not dependent on the Parkin/PINK1 mediated mitophagy pathway. Protein expression of key regulators of mitochondrial fission, phospho-Drp1Ser616 and S-OPA1, increased during EtOH treatment and recovered to normal levels after removing EtOH. In addition, the critical role of PGC-1α mediated mitochondrial biogenesis in cellular recovery was revealed: inhibition of PGC-1α using SR-18292 after EtOH removal significantly impeded recovery of mitochondrial damage, regeneration of neurites, and cell survival in a concentration-dependent manner. Taken together, our study showed reversibility of mitochondrial morphological and functional damage in stressed neuronal cells and revealed that PGC-1α mediated mitochondrial biogenesis played a critical role in the cellular recovery. This molecular mechanism could be a target for neuroprotection and neurorescue in neurodegenerative diseases.

ZLN005 alleviates PBDE-47 induced impairment of mitochondrial translation and neurotoxicity through PGC-1α/ERRα axis

Recent studies are identified the mitochondria as critical targets of 2, 2′, 4, 4′-tetrabromodiphenyl ether (PBDE-47) induced neurotoxicity. This study aimed at examining the impact of PBDE-47 exposure on mitochondrial translation, and its subsequent effect on PBDE-47 neurotoxicity. The Sprague-Dawley (SD) rat model and neuroendocrine pheochromocytoma (PC12) cells were adopted for the measurements of mitochondrial ATP levels, mitochondrial translation products, and expressions of important mitochondrial regulators, such as required meiotic nuclear division 1 (RMND1), estrogen-related receptor α (ERRα), and peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α). To delve into the role of PGC-1α/ERRα axis in mitochondrial translation, 2-(4-tert-butylphenyl) benzimidazole (ZLN005) was employed. Both cellular and animal model results shown that PBDE-47 impeded PGC-1α/ERRα axis and mitochondrial translation. PBDE-47 suppressed mitochondrial function in rat hippocampus and PC12 cells by decreasing relative mitochondrial DNA (mtDNA) content, mitochondrial translation products, and mitochondrial ATP levels. Particularly, ZLN005 reversed PBDE-47 neurotoxicity by enhancing mitochondrial translation through activation of PGC-1α/ERRα axis, yet suppressing PGC-1α with siRNA attenuates its neuroprotective effect in vitro. In conclusion, this work highlights the importance of mitochondrial translation in PBDE-47 neurotoxicity by presenting results from cellular and animal models and suggests a potential therapeutic approach through activation of PGC-1α/ERRα axis. Environmental implicationPBDEs have attracted extensive attention because of their high lipophilicity, persistence, and detection levels in various environmental media. Increasing evidence has shown that neurodevelopmental disorders in children are associated with PBDE exposure. Several studies have also found that perinatal PBDE exposure can cause long-lasting neurobehavioral abnormalities in experimental animals. Our recent studies have also demonstrated the impact of PBDE-47 exposure on mitochondrial biogenesis and dynamics, leading to memory and neurobehavioral deficits. Therefore, we explore whether the pathological mechanism of PBDE-47-induced neurotoxicity involves the regulation of mitochondrial translation through the PGC-1α/ERRα axis.

Synthesis, Photophysical Properties, Theoretical Studies, and Living Cancer Cell Imaging Applications of New 7-(Diethylamino)quinolone Chalcones.

In this article, three unsymmetrical 7-(diethylamino)quinolone chalcones with D-π-A-D and D-π-A-π-D type push-pull molecular arrangements were synthesized via a Claisen-Schmidt reaction. Using 7-(diethylamino)quinolone and vanillin as electron donor (D) moieties, these were linked together through the α,β-unsaturated carbonyl system acting as a linker and an electron acceptor (A). The photophysical properties were studied, revealing significant Stokes shifts and strong solvatofluorochromism caused by the ICT and TICT behavior produced by the push-pull effect. Moreover, quenching caused by the population of the TICT state in THF-H2O mixtures was observed, and the emission in the solid state evidenced a red shift compared to the emission in solution. These findings were corroborated by density functional theory (DFT) calculations employing the wb97xd/6-311G(d,p) method. The cytotoxic activity of the synthesized compounds was assessed on BHK-21, PC3, and LNCaP cell lines, revealing moderate activity across all compounds. Notably, compound 5b exhibited the highest activity against LNCaP cells, with an LC50 value of 10.89 μM. Furthermore, the compounds were evaluated for their potential as imaging agents in living prostate cells. The results demonstrated their favorable cell permeability and strong emission at 488 nm, positioning them as promising candidates for cancer cell imaging applications.

Tl(I) and Tl(III)-induce genotoxicity, reticulum stress and autophagy in PC12 Adh cells.

Thallium (Tl) and its two cationic species, Tl(I) and Tl(III), are toxic for most living beings. In this work, we investigated the effects of Tl (10-100µM) on the viability and proliferation capacity of the adherent variant of PC12 cells (PC12 Adh cells). While both Tl(I) and Tl(III) halted cell proliferation from 24h of incubation, their viability was ~ 90% even after 72h of treatment. At 24h, increased levels of γH2AX indicated the presence of DNA double-strand breaks. Simultaneously, increased expression of p53 and its phosphorylation at Ser15 were observed, which were associated with decreased levels of p-AKTSer473 and p-mTORSer2448. At 72h, the presence of large cytoplasmic vacuoles together with increased autophagy predictor values suggested that Tl may induce autophagy in these cells. This hypothesis was corroborated by images obtained by transmission electron microscopy (TEM) and from the decreased expression at 72h of incubation of SQSTM-1 and increased LC3β-II to LC3β-I ratio. TEM images also showed enlarged ER that, together with the increased expression of IRE1-α from 48h of incubation, indicated that Tl-induced ER stress preceded autophagy. The inhibition of autophagy flux with chloroquine increased cell mortality, suggesting that autophagy played a cytoprotective role in Tl toxicity in these cells. Together, results indicate that Tl(I) or Tl(III) are genotoxic to PC12 Adh cells which respond to the cations inducing ER stress and cytoprotective autophagy.