Neurochemical Research最新文献

Despite the considerable progress in mesenchymal stem/stromal cells (MSCs)-based novel intervention of multiple sclerosis (MS), yet the disease-modifying effect of VCAM-1⁻ MSCs and novel VCAM-1⁺ counterpart is largely obscure. In this study, we took advantage of the EAE mouse model and VCAM-1⁺ human umbilical cord-derived MSCs (hUC-MSCs) for the evaluation of the therapeutic effect of systematic MSCs infusion. On the one hand, we compared the protective effect of VCAM-1⁻ and VCAM-1⁺ hUC-MSCs against the clinical symptoms, demyelination, active glia cells and neuroinflammation in EAE mice by conducting multifaceted detections upon spinal cord and brain tissues. On the other hand, we conducted RNA-sequencing (RNA-SEQ) and multidimensional bioinformatics analyses for the evaluation of the transcriptomic features of spinal cord tissue in EAE mice after systematic hUC-MSCs infusion. Compared to those with VCAM-1⁻ hUC-MSCs injection, VCAM-1⁺ mice showed further remission in clinical manifestations, and in particular, the inflammatory infiltration and active glial cells. Mice in all groups revealed conservations in overall gene expression profiling and somatic mutation spectrum. The differentially expressed genes (DEGs) between EAE mice and those with hUC-MSCs infusion were mainly involved in neuroinflammation and inflammatory response. Our findings indicated the feasibility of VCAM-1⁺ hUC-MSCs for multiple sclerosis treatment, which would supply new references for the development of novel VCAM-1⁺ MSCs-based cytotherapy in future.

Chaperonin containing TCP1 (CCT) is an essential protein that controls proteostasis following spinal cord damage. In particular, CCT2 plays an important role in neuronal death in various neurological disorders; however, few studies have investigated the effects of CCT2 on ischemic damage in the spinal cord. In the present study, we synthesized a cell-permeable Tat-CCT2 fusion protein and observed its effects on H₂O₂-induced oxidative damage in NSC34 motoneuron-like cells and in the spinal cord after ischemic injury. Tat-CCT2, but not its control protein CCTs, was delivered into NSC34 cells in a concentration- and incubation time-dependent manner, and a clear cytosolic location of the delivered protein was observed. In addition, the delivered protein gradually degraded, and nearly control levels were observed 24 h after Tat-CCT2 treatment. Tat-CCT2 treatment significantly ameliorated 200 µM H₂O₂-induced neuronal damage in NSC34 cells at 8.0 µM protein treatment. Additionally, Tat-CCT2 significantly ameliorated H₂O₂-induced reactive oxygen species formation and DNA fragmentation. In the rabbit spinal cord, Tat-CCT2 was efficiently delivered into the spinal cord 4 h after 0.125 mg/kg protein treatment. In addition, treatment with Tat-CCT2 significantly improved the neurological scores based on the Tarlov criteria 24 and 72 h after ischemia/reperfusion. Moreover, the number of surviving neurons in the ventral horn of the spinal cord was significantly increased in the Tat-CCT2-treated group 3 and 7 days after ischemia compared to vehicle-treated group. Treatment with Tat-CCT2 alleviated the ischemia-induced oxidative stress and ferroptosis-related factor (malondialdehyde, 8-iso-prostaglandin F2α, and high mobility group box 1) and pro-inflammatory cytokine (interleukin-1β, interleukin-6, and tumor necrosis factor-α) releases in the ventral horn of the spinal cord 8 and 24 h after ischemia/reperfusion. In addition, Tat-CCT2 treatment significantly ameliorated ischemia-induced microglial activation in the ventral horn of spinal cord 24 h after reperfusion. These results suggest that Tat-CCT2 mitigates ischemia-induced neuronal damage in the spinal cord.

Spinal cord injury (SCI) is a complex debilitating condition leading to permanent life-long neurological deficits. Estrogen (E2) treatment is known to be neuroprotectant in SCI. This hormone is highly pleiotropic and has been shown to decrease apoptosis, modulate calcium signaling, regulate growth factor expression, act as an anti-inflammatory, and drive angiogenesis. These beneficial effects were found in our earlier study at the low dose of 10 µg/kg E2 in rats. However, the dose remains non-physiologic, which poses a safety hurdle for clinical use. Thus, we recently devised/constructed a fast release nanoparticle (NP) estrogen embedded (FNP-E2) construct and tested a focal delivery system in a contused SCI rat model which showed protection in the short run. In the current study, we have developed a novel slow-release NP estrogen (SNP-E2) delivery system that shows sustained release of E2 in the injured spinal cord and no systemic exposure in the host. The study of E2 release and kinetics of this SNP-E2 construct in vitro and in vivo supported this claim. Delivery of E2 to the injured spinal cord via this approach reduced inflammation and gliosis, and induced microglial differentiation of M1 to M2 in rats after SCI. Analysis of spinal cord samples showed improved myelination and survival signals (AKT) as demonstrated by western blot analysis. SNP-E2 treatment also induced astrocytic differentiation into neuron-like (MAP2/NeuN) cells, supported the survival of oligodendrocyte precursor cells (OPC), and improved bladder and locomotor function in rats following SCI. These data suggest that this novel delivery strategy of SNP-E2 to the injured spinal cord may provide a safe and effective therapeutic approach to treat individuals suffering from SCI.

Sepsis-associated encephalopathy (SAE) is a severe neurological complication of sepsis, characterized by cognitive impairment and increased mortality. Owing to the established neuroprotective and immunomodulatory effects of Mesencephalic Astrocyte-derived Neurotrophic Factor (MANF) in a plethora of neurological disorders, our study aimed to investigate the role of MANF in SAE and evaluate its potential as a therapeutic target. Employing a cecal ligation and puncture (CLP) mouse model of sepsis, we analyzed MANF expression in the hippocampus and cortex, and evaluated the influence of intranasally administered recombinant human MANF (rhMANF) on symptoms of SAE. Our results disclosed a substantial increase in MANF protein levels within the hippocampus and cortex of septic mice, primarily found in neurons. Post-CLP surgical administration of rhMANF led to numerous favorable outcomes. Specifically, rhMANF therapy mitigated sepsis-induced behavioral deviations and cognitive impairments, as gauged by SHIRPA scores and Morris water maze tests, and enhanced survival rates in septic mice. These enhancements were concomitant with alterations in neuroinflammation and synaptic integrity. The rhMANF treatment attenuated activation of microglia and astrocytes in the hippocampus and cortex, as evidenced by diminished Iba-1 and GFAP positive cells. It also curtailed the generation of pro-inflammatory cytokines TNF-α and IL-6, and obstructed the p38 MAPK inflammatory pathway. Moreover, rhMANF sustained the expression of synaptic proteins PSD95 and SYN, and conserved neuronal integrity, as demonstrated by Nissl staining. In conclusion, our study underscores the potential of MANF as an innovative therapeutic target for SAE, emphasizing its anti-inflammatory and neuroprotective capabilities.

Chronic stress disrupts dopamine (DA) transmission, adversely affecting mood and contribution to neuropsychiatric disorders like ADHD, autism, schizophrenia, anxiety, depression, and drug addiction. The neuropeptide oxytocin (OXT) plays a key role in social cognition, bonding, attachment, and parenting behaviors. In addition, OXT can modulate the activity of the HPA axis, counteracting the effects of stress, and alleviating fear and anxiety. However, whether OXT can mitigate stress-induced DA dysfunction and the underlying mechanisms remains unclear. This study investigated the neuroprotective effects of OXT on corticosterone (CORT) induced DA dysfunction in the neuroblastoma cell line SH-SY5Y. The results revealed that CORT decreases the levels of intracellular signaling molecules associated with DA function, including phosphorylated tyrosine hydroxylase (pTH), phosphorylated cAMP response element-binding protein (pCREB), and protein kinase A (PKA). Interestingly, pretreatment with OXT mitigated CORT-induced DA dysfunction through its potent PKA activator properties. In addition, the neuroprotective effect of OXT was abolished by atosiban (an OXT receptor antagonist) or H89 (a PKA inhibitor). Our results suggest that OXT protects dopaminergic neuroblastoma cells from CORT-induced DA dysfunction, potentially through the involvement of oxytocin receptors and the PKA/CREB signaling pathway. These findings contribute to the understanding of the neurobiological mechanisms underlying stress resilience and highlight potential pathways for developing targeted treatments that leverage the neuroprotective properties of OXT to address disorders characterized by DA dysregulation and impaired stress responses.

Lead (Pb), a dense, soft, blue-gray metal, is widely used in metallurgy, cables, storage batteries, pigments, and other industrial applications. Pb has been shown to cause degenerative changes in the nervous system. Necroptosis, a form of non-apoptotic programmed cell death modality, is closely associated with neurodegenerative diseases. Whether the TNF-R1-RIPK1/RIPK3 pathway is involved in the neurodegeneration induced by Pb has yet to be determined. Here, we explored the role of the TNF-R1-RIPK1/RIPK3 signaling pathway in the Pb-induced necroptosis by using HT-22 cells, primary mouse hippocampal neurons, and C57BL/6 mice models, demonstrating that Pb exposure elevated lead levels in murine whole blood and hippocampal tissue in a dose-response relationship. Protein expression levels of PARP, c-PARP, RIPK1, p-RIPK1, RIPK3, MLKL, and p-MLKL in the hippocampal tissues were elevated, while the protein expression of caspase-8 was decreased. Furthermore, Pb exposure reduced the survival rates in HT-22 cells and primary mouse hippocampal neurons, while increasing the protein expressions of RIPK1 and p-MLKL. Collectively, these novel findings suggest that the TNF-R1/RIPK1/RIPK3 signaling pathway is associated with Pb-induced neurotoxicity in hippocampal neurons in mice.

Transplantation of bone marrow mesenchymal stem cells (BMSCs) represents an encouraging strategy for the repair of spinal cord injury (SCI), however, its effectiveness on treating SCI remains controversial. Bilobalide isolated from Ginkgo biloba leaves shows significant neuroprotective effects. We examined the role and underlying mechanism of bilobalide in the efficacy of BMSC transplantation on SCI. Primary BMSCs were isolated from neonatal rats, and cell viability was assessed by MTT assay. Neuronal markers (MAP-2, NeuN, NSE and Tuj1), autophagy markers (LC3 and Beclin1), and Fragile X mental retardation protein (FMRP)/With-no-lysine kinase-1 (WNK1) signaling were measured using RT-qPCR and western blotting. The relationship of FMRP and WNK1 was estimated by RNA immunoprecipitation, while WNK1 mRNA stability was assessed with actinomycin D assay. In a SCI rat model, tissue injury was examined using HE and Nissl staining. Bilobalide treatment facilitated neural differentiation of BMSCs, as well as enhanced autophagy and inhibited WNK1 signaling. The promotive effect of bilobalide on BMSC differentiation was antagonized when overexpressing WNK1 or inhibiting autophagy. Bilobalide upregulated FMRP to promote WNK1 mRNA decay, thus reducing WNK1 expression. FMRP knockdown reversed the promoted functions of bilobalide on autophagy and neuronal differentiation in BMSCs. Additionally, compared to either monotherapy, simultaneous treatments with bilobalide and BMSCs further facilitated autophagy and neuronal differentiation, thereby enhancing the repair of SCI in rats. Bilobalide enhances autophagy activity to promote BMSC neuronal differentiation via FMRP/WNK1 axis, thus improving functional recovery following SCI, which indicates a promising therapeutic approach for SCI.

The dopamine D1-like receptor is a dopamine (DA) receptor regulating diverse brain functions. Once the dopamine D1-like receptor is activated, it induces activation of the Protein Kinase A (PKA) that phosphorylates the cAMP Response Element-Binding (CREB) transcription factor, which once active elicits the expression of the critical synaptic elements Activity-regulated cytoskeleton-associated (Arc) and the Brain-Derived Neurotrophic Factor (BDNF). The temporality and subcellular localization of proteins impact brain function. However, there is no information about the temporality of CREB activation and Arc and BDNF levels induced through dopamine D1-like receptor activation. In this study, we aimed to assess the specific effect of dopamine D1-like receptor activation on the temporality of CREB-phosphorylation (p-CREB^S133) and the spatiotemporal induction of Arc and BDNF. Using SY-SY5Y cells differentiated with Retinoic Acid (RA), the dopamine D1-like receptor activation with a specific agonist transiently increased p-CREB^S133 at 30 min of stimulation. It induced two spikes of Arc protein at 15 min and 6 h, forming clusters near the cell membrane. BDNF secretion temporarily increased, reaching a maximum at 6 h, while secretion was lower at 24 h compared to the unstimulated group. Our results provide new insight into the role of dopamine D1-like receptor activation on CREB activation, Arc, and BDNF increase, showing that these effects occur temporally and for Arc in subcellular specific sites. This study highlights the dopaminergic system as a critical regulator of subcellular events relevant to neuron plasticity. Future research should address the study of the implications for brain function and behavior.

Chronic fatigue stress (CFS) is a multisystem disorder which exhibits multiple signs of neurological complications like brain fog, cognitive deficits and oxidative stress with no specific treatment. Doxophylline, a non-selective phosphodiesterase inhibitor (PDEI), has anti-inflammatory properties with enhanced blood-brain barrier penetration and tissue specificity. We have evaluated the neuroprotective potential of doxophylline in a murine model of forced swim test (FST) induced CFS and in H₂O₂ (hydrogen peroxide) induced oxidative stress in PC12 cells. An FST model to induce a state of CFS in mice was induced by forcing them to swim daily for 6 min for 15 days. The drug was administered daily 30 min prior to FST. The immobility period was compared for day 1 and day 15. Animals were sacrificed on day 16 for biochemical, mitochondrial, and histopathological estimations in the brain. Cytotoxicity assay, reactive oxygen species (ROS) and nuclear morphology determination were carried out in PC12 cells. A significant increase in immobility has been observed on the 15th day in CFS-induced mice compared to doxophylline treated group. Neurobehavioral studies revealed hypo locomotion, anxiety, motor incoordination, and memory deficit. Biochemical analysis showed a significant change in oxidative stress markers (superoxide dismutase (SOD), reduced glutathione (GSH), catalase, lipid peroxidation (LPO) and nitrite levels) and acetylcholinesterase enzyme activity (AChE) in brain homogenates. Doxophylline pre-treatment protects against these impairments. In PC12 cell lines, doxophylline exhibits alleviation against H₂O₂-induced oxidative stress, intracellular ROS generation, and changes in nuclear morphology. Doxophylline could be promising and possess therapeutic potential in CFS treatment. Further research is needed to test if doxophylline can be repurposed for neurological disorders.

Recent epidemiological and experimental studies have increasingly highlighted the association between environmental pollution, especially ultrafine particulate matter (PM), and the risk of neurodegenerative diseases, such as Parkinson’s disease (PD). These previous studies suggest a potential mechanism by which ultrafine PM contributes to neuronal damage through processes, such as iron accumulation and oxidative stress. In this study, we aimed to elucidate the effects of ultrafine PM on ferroptosis, an iron-dependent form of cell death, in the mouse substantia nigra pars compacta (SNc) and to evaluate the protective role of α-lipoic acid (ALA). Mice were exposed to ultrafine diesel exhaust particles (ufDEP), a type of ultrafine PM, intranasally and injected ALA intraperitoneally for seven consecutive days. Iron accumulation and lipid peroxidation were significantly increased, and antioxidant capacity was significantly decreased in the SNc after ufDEP exposure, highlighting the deleterious effects of ufDEP on tyrosine hydroxylase (TH)-positive neurons. In contrast, ALA treatment effectively mitigated these effects by reducing iron accumulation, decreasing lipid peroxidation, and restoring antioxidant levels, resulting in the protection of TH-positive neurons from ferroptotic damage. Our results provide evidence that ufDEP can induce ferroptosis in dopaminergic neurons in the SNc, potentially contributing to PD pathogenesis. Furthermore, ALA showed protective effects against ufDEP-induced ferroptotic damage, suggesting its potential as a therapeutic intervention for PD.