Nissl Staining Research Articles

L-NRB alleviates amyotrophic lateral sclerosis by regulating P11-Htr4 signaling pathway

IntroductionL-NRB is a compound formed as a ring cleavage product of butylphthalide and borneol in a molar ratio 1:2. This study aimed to explore the therapeutic effect of L-NRB on amyotrophic lateral sclerosis (ALS) and its possible mechanism. MethodsSOD1-G93A mice were used as an ALS model. Behavioral tests, histopathological staining, Nissl staining, immunohistochemistry, enzyme-linked immunosorbent assays, and Western blotting were used to analyze the therapeutic effect. The underlying mechanism of L-NRB in treating ALS was investigated using transcriptomic analyses. ResultsIt was found that L-NRB alleviated motor dysfunction, pathological changes in the gastrocnemius muscle, and motor neuron injuries.The results indicated that L-NRB had a neuroprotective function associated with the inhibition of neuroinflammation. The anti-apoptotic effect of L-NRB was found to be related to the regulation of the P11-Htr4 signaling pathway. ConclusionIn summary, the results demonstrated the therapeutic effect of L-NRB on ALS and suggest a promising new therapeutic candidate for ALS.

Unraveling Neurotoxicity Discrepancies: Comparative In vitro and In vivo Analysis of Colistin and Polymyxin B and the Underlying Mechanisms.

Polymyxins, including colistin and polymyxin B, are the final resort against Gram-negative bacterial infections. However, its clinical application is restricted due to concerns related to neurotoxicity. Despite the similar antibacterial spectrum and mode of action shared between colistin and polymyxin B, there is still a lack of definitive evidence to support the idea that their neurotoxicity profiles are identical. To comprehensively compare the neurotoxicity between colistin and polymyxin B both in vivo and in vitro and establish a theoretical foundation to guide the rational use of polymyxins within clinical settings. in vitro experiments simulated nerve damage by exposing N2a and RSC96 cells to colistin and polymyxin B. The evaluation of nerve injury included assessments of cell viability and apoptosis. To discern the variance in the mechanisms of nerve injury between colistin and polymyxin B, oxidative stress levels were examined, such as SOD, CAT, GSH, and malondialdehyde (MDA). In in vivo experiments, a rat nerve injury model was created by intraventricular injections of colistin and polymyxin B, respectively. The impact of these drugs on brain injury in rats, particularly within the hippocampus and medulla oblongata, was measured using HE and Nissl staining. The potential influence of polymyxins on the ferroptosis pathway was evaluated by assessing LPO and Fe2+ levels and the degree of mitochondrial impairment. At equivalent doses, colistin demonstrated a reduced level of neurotoxicity compared to polymyxin B, both in vitro and in vivo. in vitro experiments revealed greater cell viability and a lower apoptosis rate after colistin treatment than after polymyxin B treatment. This variance in outcomes could be attributed to the comparatively lower levels of oxidative stress associated with colistin administration.In a rat model, nerve injury resulted in observable damage to both the hippocampus and the medulla oblongata. A comprehensive assessment of the extent of damage in the CA1 to CA4 regions of the hippocampus, and the solitary tract nucleus of the medulla oblongata underscored that the neurotoxic effects of colistin remained milder compared to those elicited by polymyxin B. Even when evaluated at equivalent multiples of clinically recommended doses, colistin exhibited lower neurotoxicity in vivo than polymyxin B. For the first time, this study demonstrated the role of ferroptosis in polymyxin B-induced nerve damage. The activation levels observed within the ferroptosis pathway due to polymyxin B exceeded those triggered by colistin. Colistin exhibited a marked reduction in neurotoxicity compared to polymyxin B, evident in both the equivalent and clinically recommended doses. These findings suggest that, from the perspective of neurotoxicity, colistin presents a more favorable option for clinical use.

Safflower Yellow Alleviates Cognitive Impairment in Mice by Modulating Cholinergic System Function, Oxidative Stress, and CREB/BDNF/TrkB Signaling Pathway

Ethnopharmacological relevanceCarthamus tinctorius L. (Safflower) was believed to have multiple benefits, including antioxidant effects, enhanced learning and memory, and improving neuronal injury. Safflower Yellow(SY) are the main active ingredients of Safflower, displays strong pharmacological potential treatment of Alzheimer's disease(AD). However, its effect on memory impairments remains insufficiently investigated. Aim of the study:The study aims to investigate the effects of SY on cognitive functions in memory impairments model and to explore the mechanism of its action. Materials and methodsWe utilized the Morris Water Maze, Step-Through Test, Step-Down Test to assess the potential of SY in ameliorating learning and memory dysfunction caused by SCOP, NaNO2 and ethanol in mice. Bioinformatic analysis and molecular biological approaches were used to study the related mechanisms of SY on anti-memory impairments. ResultsThe results of the Morris Water Test suggested that SY could shorten the escape latency and the time of the first crossing platform in the mice with memory acquisition and memory consolidation impairments, and increase the platform crossing times. The results of the Step-Though test and Step-Down test showed that the escape latency in the mice was prolonged and the number of errors was reduced after SY treatment. ELISA experiments indicated that SY decreased the AChE activities, increased the ChAT activities, and modulated oxidative stress markers (SOD, MDA, and GSH-PX) in scopolamine-induced mice. Western Blot and Nissl staining showed that SY could activated BDNF/TrkB/CREB signaling pathway and reduced neuronal damage. ConclusionThe findings present that SY can restore the function of the cholinergic system, inhibit oxidative stress, regulate the expression of upstream and downstream proteins in the CREB/BDNF/TrkB pathway, and alleviate brain tissue damage to improve memory impairment in mice.

Gentiopicroside Attenuates Lithium/Pilocarpine-Induced Epilepsy Seizures by Down-Regulating NR2B/CaMKII/CREB and TLR4/NF-κB Signaling Pathways in the Hippocampus of Mice

Background: Epilepsy is a prevalent and disabling neurological condition characterized by recurrent seizures. Approximately 50% of adults with active epilepsy have at least one comorbidity and they are at a greater risk of premature death than the general population. Gentiopicroside (Gent) is a primary component of Gentiana macrophylla Pall. that has been shown to have diverse pharmacological properties. However, its role in epileptic seizures in adult mice and its underlying mechanism of action remain obscure. We aimed to explore the anti-epileptic effect and mechanism of Gent on lithium/pilocarpine (Pilo)-induced epilepsy seizures in mice. Methods: In this study, we established a lithium/Pilo-induced epilepsy model, and Gent was first given to mice 30 min before Pilo administration. Then, we detected behavioral and histopathological changes through electrocorticographic (ECoG) measurements, Nissl staining, Fluoro-Jade B (FJB) staining, and immunohistochemical staining. We then used molecular biology techniques, such as Western blotting, quantitative polymerase chain reaction (qPCR) analysis, and the enzyme-linked immunosorbent assay (ELISA) to investigate the mechanisms of Gent in lithium/Pilo-induced epileptic seizures in mice and lipopolysaccharide (LPS)-induced inflammatory astrocytes. Results: We confirmed that Gent could prevent abnormal ECoG activity, behavioral changes, and neurodegeneration. Subsequently, we found Gent could downregulate the factors that could promote apoptosis (i.e., the NR2B/CaMKII/CREB signaling cascade) and neuroinflammatory-related factors (i.e., the TLR4/NF-κB signaling cascade). Conclusions: Gent could be a potential therapeutic agent for epilepsy, offering possibilities for both prevention and treatment. Our research establishes a preliminary experimental framework for ongoing studies into Gent’s efficacy as a treatment for epilepsy.

GABAB modulate NF-κB/NLRP3 pathways in electroacupuncture prevention of depression in CUMS rats

BackgroundOur previous research has demonstrated that electroacupuncture (EA) has the potential to mitigate depression-like symptoms resulting from chronic stress. However, further investigation is required to fully understand the underlying mechanisms. The regulatory role of γ-aminobutyric acid type B (GABAB) in synaptic plasticity and the involvement of NF-κB/NLRP3-mediated inflammation in the lateral habenula nucleus (LHb) are key factors in the development of depression. This study sought to investigate the potential of EA in mitigating depression-like symptoms induced by chronic stress through mechanisms such as enhancing GABAB levels, regulating synaptic plasticity in the LHb, and suppressing NF-κB/NLRP3-mediated inflammation. MethodsSprague-Dawley rats were exposed to chronic unpredictable mild stress (CUMS) in order to create a model of depression. Subsequently, the weight and behavioral assessments of all rats were monitored, and samples of the lateral habenula and serum were collected. The protein expression levels were analyzed using western blotting. The 5-hydroxytryptophan (5-HT), Dopamine (DA), and Norepinephrine (NE) in the LHb and serum were measured using ELISA. The alterations in GABAB and NF-κB in the LHb were observed through immunofluorescence. The neuronal damage in the LHb was assessed using Nissl staining. ResultsEA upregulated the expression of GABAB in the LHb of rats subjected to CUMS. Subsequent behavioral assessments indicated that blocking GABAB attenuated the antidepressant effects of EA in CUMS-exposed rats. Furthermore, EA enhanced synaptic plasticity in the LHb of CUMS-exposed rats and mitigated NF-κB/NLRP3-mediated inflammatory responses, with these effects potentially being reversed by GABAB inhibition. ConclusionThrough the promotion of GABAB levels, regulation of synaptic plasticity within the LHb, and inhibition of NF-κB/NLRP3-mediated neuroinflammation in the same region, electroacupuncture at Shangxing and Fengfu acupoints demonstrates efficacy in mitigating depression-like behaviors induced by CUMS.

Thioflavin-T: application as a neuronal body and nucleolar stain and the blue light photo enhancement effect

Thioflavin-T (THT) is a common and indispensable tool for the study of amyloid pathologies and protein aggregation, both in vitro and for histological samples. In this study we expand the use of THT beyond its canonical usage for staining amyloid plaques and demonstrate its novel use as an easy and rapid stain comparable to fluorescent Nissl staining, allowing for clear discernment of neuronal cell bodies and also nucleoli in fixed tissue and live cells. We believe that this is of value for any lab that studies central nervous system (CNS) tissues. Furthermore, we show that THT could potentially be used as a an alternative to the use of fluorescent reporters or other more costly RNA binding compounds in the study of nucleolar dynamics owing to its ability to clearly stain nucleoli in live cells. We also discovered the previously unreported effect of blue light exposure on the photo enhancement of THT excited by a 488 nm laser in stained tissue sample and how to avoid complications arising from this effect. Finally, we provide a simple protocol that can be easily adjusted either for using THT as a neuronal cell body and nucleoli stain, compatible with antibody based staining methods tested up to 4 fluorophores, or alternatively by using an additional washing step the protocol may be used for amyloid plaque detection in fixed brain tissue.

Nucleophosmin 1 overexpression enhances neuroprotection by attenuating cellular stress in traumatic brain injury

BackgroundTraumatic Brain Injury (TBI) is a multifaceted injury that can cause a wide range of symptoms and impairments, leading to significant effects on brain function. Nucleophosmin 1 (NPM1), a versatile phosphoprotein located in the nucleolus, is being recognized as a possible controller of cellular stress reactions and could be important in reducing neuro dysfunction caused by TBI. However the critical roles of NPM1 in cellular stress in TBI remains unclear. MethodsWe employed a control cortical impact mouse model and a scratch-induced primary neuronal culture model. Hematoxylin and eosin staining was used to evaluate tissue damage and cellular changes, with NPM1 expression in the cortical area assessed through immunofluorescence staining and Western blot analysis. Neuronal morphology was assessed using Nissl staining. Behavioral assessments were performed to evaluate the impact of NPM1 overexpression on neurobehavioral results in TBI mice. Mitochondrial function was assessed using an Extracellular Flux Analyzer. ResultsFollowing TBI, an increase in NPM1 expression was observed, with a peak at 72 h post-injury. Increased levels of NPM1 resulted in decreased neuronal cell death, as shown by Nissl staining, and lower levels of Caspase 8, APE1, H2AX, and 8-OHDG expression, indicating a reduction in DNA damage. NPM1 overexpression also resulted in improved neurobehavioral outcomes, characterized by decreased neurological deficits and enhanced motor function post-TBI. Additionally, in vitro, scratch-induction experiments revealed that NPM1 overexpression mitigated mitochondrial damage, as evidenced by the downregulation of P53, BCL2, and Cyto C expression levels and improvements in mitochondrial respiratory function. ConclusionThese findings suggest NPM1 as a promising target for developing interventions to alleviate TBI-related cellular stress and promote neuronal survival.

Experimental peri-implantitis induces neuroinflammation: An exploratory study in rats

PurposeCumulating evidence supports the close association between periodontal diseases, neuroinflammation and neurodegenerative pathologies, except for peri-implantitis (PI). Thus, this study explored the association between experimental PI and neuropathological changes in the rat brain.Materials and methodsAfter bilateral first molars extraction, experimental PI was induced at titanium implants placed in the maxillae by lipopolysaccharide injections and ligature placement. Following 28-weeks of disease progression, the maxillae and brains were retrieved from 6 rats. Healthy brains from 3 rats were used as control. Brains were analyzed by immunohistochemistry to detect signs of neuroinflammation (interleukin (IL)-6 and tumor necrosis factor (TNF)-α)), microglial activation (IBA-1) and astrogliosis (GFAP). To explore signs of neurodegeneration, hematoxylin/eosin and Nissl stainings were used. Also, four different antibodies against amyloid beta (Aβ 1–42) were tested.ResultsChronic PI lesions showed peri-implant bone resorption accompanied by large inflammatory infiltrates. IL-6+ and TNF-α+ cells were found within the CA1 and Dentate Gyrus regions of the hippocampus of the PI-affected group, while almost no immune-positivity was detected in the control (p < 0.05). Detection of activated GFAP+ microglia and IBA-1+ astrocytes surface were significantly higher at the CA areas, and cerebral cortex of the PI-affected group, in comparison with control (p < 0.05). Shrunk neurons with pyknotic nuclei were inconsistently found among the PI-affected group, and these were almost not detected in control. No positive Aβ reactivity was detected in any of the samples.ConclusionChronic experimental PI lesions led to an increased detection of IL-6 and TNF-α, GFAP+ microgliosis and IBA-1+ astrocytosis, and in some cases, neurodegeneration, in the rat brain.

An endophenotype network strategy uncovers YangXue QingNao Wan suppresses Aβ deposition, improves mitochondrial dysfunction and glucose metabolism

BackgroundAlzheimer's disease (AD), an escalating global health issue, lacks effective treatments due to its complex pathogenesis. YangXue QingNao Wan (YXQNW) is a China Food and Drug Administration (CFDA)- approved TCM formula that has been repurposed in clinical Phase II for the treatment of AD. Identifying YXQNW's active ingredients and their mechanisms is crucial for developing effective AD treatments. PurposeThis study aims to elucidate the anti-AD effects of YXQNW and to explore its potential therapeutic mechanisms employing an endophenotype network strategy. MethodsHerein we present an endophenotype network strategy that combines active ingredient identification in rat serum, network proximity prediction, metabolomics, and in vivo experimental validation in two animal models. Specially, utilizing UPLC-Q-TOF-MS/MS, active ingredients are identified in YXQNW to build a drug-target network. We applied network proximity to identify potential AD pathological mechanisms of YXQNW via integration of drug-target network, AD endophenotype gene sets, and human protein interactome, and validated related mechanisms in two animal models. In a d-galactose-induced senescent rat model, YXQNW was administered at varying doses for cognitive and neuronal assessments through behavioral tests, Nissl staining, and transmission electron microscopy (TEM). Metabolomic analysis with LC-MS revealed YXQNW's influence on brain metabolites, suggesting therapeutic pathways. Levels of key proteins and biochemicals were measured by WB and ELISA, providing insights into YXQNW's neuroprotective mechanisms. In addition, 5×FAD model mice were used and administered YXQNW by gavage for 14 days at two doses. Amyloid-β levels, transporter expression, and cerebral blood flow have been detected by MRI and biochemical assays. ResultsThe network proximity analysis showed that the effect of YXQNW on AD was highly correlated with amyloid β, synaptic function, glucose metabolism and mitochondrial function. The results of metabolomics combined with in vivo experimental validation suggest that YXQNW has the potential to ameliorate glucose transport abnormalities in the brain by upregulating the expression of GLUT1 and GLUT3, while further enhancing glucose metabolism through increased O-GlcNAcylation and mitigating mitochondrial dysfunction via the AMPK/Sirt1 pathway, thereby improving d-galactose-induced cognitive deficits in rats. Additionally, YXQNW treatment significantly decreased Aβ1–42 levels and enhanced cerebral blood flow (CBF) in the hippocampus of 5×FAD mice. while mechanistic findings indicated that YXQNW treatment increased the expression of ABCB1, an Aβ transporter, in 5×FAD model mice to promote the clearance of Aβ from the brain and alleviate AD-like symptoms. ConclusionsThis study reveals that YXQNW may mitigate AD by inhibiting Aβ deposition and ameliorating mitochondrial dysfunction and glucose metabolism, thus offering a promising therapeutic approach for AD.

WuYou decoction effectively reduces neuronal damage, synaptic dysfunction, and Aβ production in rats exposed to chronic sleep deprivation by modulating the Aβ-related enzymes and SIRT1/Nrf2/NF-κB pathway

Ethnopharmacological relevanceChronic sleep deprivation (CSD) can result in neuronal damage, synaptic dysfunction, Aβ production, neuroinflammation, and ultimately cognitive deterioration. WuYou Decoction (WYD), a contemporary prescription, has shown promise in enhancing sleep quality and cognitive performance in individuals with insomnia. However, the specific molecular mechanisms responsible for the neuroprotective effects of WYD on CSD remain incompletely understood. Aim of the studyThis study aimed to investigate the neuroprotective effects of WYD on the CSD model and its molecular mechanism. Materials and methodsUHPLC-MS/MS analysis was utilized to analyze the active ingredients of WYD extract. The study employed the multi-platform water environment method to establish the CSD model in rats. Subsequent to treatment with varying doses of WYD in CSD rats, cognitive function and pathological alterations in hippocampus and cortex, including neuronal damage, synaptic dysfunction, Aβ production, and neuroinflammation, were evaluated through a combination of Morris Water Maze test, HE staining, Nissl staining, Golgi-Cox staining, Transmission electron microscope, ELISA, Immunohistochemistry staining, Immunofluorescence staining and Western blot. ResultsUHPLC-MS/MS analysis revealed a total of 99 active ingredients were identified from the WYD extract. The administration of WYD exhibited a mitigation of cognitive decline in the model of CSD, as evidenced by increased neuron count in the hippocampus and cortex, and improved density and length of dendritic spines in these brain regions. Furthermore, WYD was found to suppress the Aβ production, and inhibit the expression of BACE1, PS1, GFAP, IBA1, IL-1β, IL-6, TNF-α, phosphorylated IκBα (Ser32) and phosphorylated NF-κB p65 (Ser536) in the hippocampus and cortex, while also increasing the levels of PSD95, SYN1, ADAM10, IDE, SIRT1 and Nrf2. ConclusionsWYD exhibits neuroprotective properties in CSD, potentially through modulation of the Aβ-related enzymes and SIRT1/Nrf2/NF-κB pathway.

Long-term hypothermia amplified neuroprotection by antagonizing intracranial pressure rebound after severe traumatic brain injury in rats.

Long-term hypothermia has been reported to prevent intracranial pressure (ICP) rebound in clinical patients, but the duration for hypothermia and the corresponding ICP data are not available. This study investigated the optimal duration of long-term hypothermia in traumatic brain injury (TBI) rats, and observed the effect on ICP and neurological function. In this study, we established a rat severe TBI model with electronic Controlled Cortical Injury device, and implemented hypothermia (33 °C) for different durations. The motor function of the rats in each group was evaluated by beam walking test and inclined-grid climbing test, brain water content was calculated by the wet-dry weight method, Evan's blue staining was used to measure the blood-brain barrier (BBB) permeability, the change of hippocampal neurons was observed by Nissl staining, the expressions of BrdU, NeuN, and CD86 positive cells were detected by immunofluorescence staining, and the expressions of Bcl-2, Bax, iNOS, IL-10, and Arg-1 were detected by Western blot. We found that therapeutic hypothermia improved neurological recovery after TBI with declining ICP, reducing brain edema, decreasing BBB permeability, promoting neurogenesis, inhibiting apoptosis, and regulating inflammation. Moreover, 48 h hypothermia amplified the neuroprotective effect after injury on the basis of 4 or 24 h hypothermic treatment. Both 4 and 24 h hypothermia led to ICP rebound during or after rewarming, whereas 48 h hypothermia completely abolished ICP rebound. Our study suggests that long-term hypothermia amplifies neuroprotection after TBI by antagonizing ICP rebound.

Pyrazolone-nicotinic acid derivative (4Z)-4-(2-hydroxybenzylidine)-5-methyl-2-(pyridine-3-ylcarbonyl)-2, 4-dihydro-3H-pyrazole-3-one (IIc) as multitarget inhibitor of neurodegeneration and behavioural impairment in Dementia.

The study was aimed at the synthesis and pharmacological investigation of (4Z)-4-(2-hydroxybenzylidine)-5-methyl-2-(pyridine-3-ylcarbonyl)-2, 4-dihydro-3H-pyrazole-3-one (IIc) in mice model of scopolamine-induced neurodegeneration and cognition impairment. The behavioural studies included Y-Maze Test, Water Morris Test, and Novel Object Recognition Test in Albino mice (20-25g). Scopalamine was used as an inducing agent. The acetylcholinesterase (AChE) inhibitory assay was used to assess the role of the test compounds in vitro. The Crystal Violet Staining (Nissl staining) was used to assess the neuroprotective and antiapoptotic effect through quantifying the number of neurons and viability. The expression of the anti-inflammatory enzyme cyclooxygenase-2 (COX-2), cytokine tumour necrotic factor (TNF-α), key transcription factor producing pro-inflammatory signals nuclear factor kappa B (P-NFkB), and apoptosis marker p-JNK was validated through enzyme-linked immunosorbent assay (ELISA) and immunohistochemical (IHC) analysis. The tested compound reverted cognitive and behavioural impairment through inhibiting scopolamine-induced inflammation and oxidative stress. We found that the compound IIc improved the short-term memory and learning behaviour of the experimental animals. Further investigation into molecular mechanisms showed that this effect was the manifestation of immunomodulatory, antioxidant, and consequently, of downsizing of inflammatory cytokines. These results were further validated through docking analysis. Finally, we conclude that the pyrazolone-nicotinic acid derivative IIc reversed the scopolamine-induced cognitive and behavioural deficits, attributed to acetylcholinesterase inhibition, neuronal recovery, antioxidant potential, and through downregulating the neuroinflammatory mediators p-NF-kB, cytokine TNF-α, and anti-inflammatory enzyme COX-2.

Multi-Protective Effects of Petunidin-3-O-(trans-p-coumaroylrutinoside)-5-O-glucoside on D-Gal-Induced Aging Mice

Petunidin-3-O-(trans-p-coumaroylrutinoside)-5-O-glucoside (PtCG), the primary anthocyanin ingredient in Lycium ruthenicum Murr., possesses a range of biological activities, including antioxidative properties and melanin inhibition. This study aimed to investigate the protective effect of PtCG on D-galactose (D-gal)-induced aging in female mice and elucidate the underlying molecular pathways. Behavioral experiments, including the MWW and Y-maze tests, revealed that PtCG significantly ameliorated cognitive decline and enhanced learning and memory abilities in aging mice. Regarding biochemical indicators, PtCG considerably improved superoxide dismutase (SOD) and glutathione (GSH) activity while reducing malondialdehyde (MDA) and acetylcholinesterase (AChE) levels in the hippocampus and serum. Furthermore, PtCG ingestion alleviated liver injury by decreasing alanine transaminase (ALT), aspartate transaminase (AST), and alkaline phosphatase (AKP) levels, and attenuated renal damage by reducing blood urea nitrogen (BUN) and uric acid (UA) levels. Transmission electron microscopy (TEM) results demonstrated that PtCG restored the function and quantity of synapses in the hippocampus. Hematoxylin and eosin (H&amp;E), Masson’s trichrome, and Nissl staining revealed that PtCG significantly improved the relevant pathological characteristics of liver and hippocampal tissues in aging mice. The molecular mechanism investigation showed that PtCG downregulated the protein expression of microglial marker ionized calcium-binding adapter molecule 1 (Iba1), astrocytic marker glial fibrillary acidic protein (GFAP), β-secretase 1 (BACE-1), and amyloid-beta1–42 (Aβ1–42) in the hippocampus of aging mice. The protein expression of inflammatory pathway components, including nuclear factor-kappa B (NF-κB), cyclooxygenase-2 (COX2), inducible nitric oxide synthase (iNOS), and interleukin-1 beta (IL-1β), was also suppressed. These findings suggest that PtCG may possess anti-aging properties, with its mechanism of action potentially linked to the attenuation of neuroinflammation, oxidative stress, and liver and kidney damage. PtCG may have future applications as a functional food for the treatment of aging-related disorders.

SIRT1 modulates microglia phenotypes via inhibiting drp1 phosphorylation reduces neuroinflammation in heatstroke

BackgroundBrain injury often results in high mortality rates and significant sequelae following severe heatstroke (HS). Neuroinflammation aggravates HS-induced brain injury, yet the involvement of microglia in heat-induced neuroinflammation deserves further investigation. MethodsOur study investigated activation status, phenotype markers, production of pro-inflammatory cytokine and reactive oxygen species (ROS) of microglia both in vitro and in vivo under HS. Utilizing high-throughput sequencing, we identified SIRT1 as a potential modulator of microglia phenotype, and observed that SIRT1 alleviated severe heatstroke-induced brain injury following intraperitoneal administration of the SIRT1 agonist SRT-1720 and the inhibitor selisistat. Additionally, the effects of SRT-1720 and selisistat on mitochondrial dynamics and microglial phenotype transition were examined in BV2 cells in vitro. ResultsHeatstroke promotes microglia activation, as evidenced by the increased production of pro-inflammatory cytokine and reactive oxygen species. High-throughput sequencing revealed elevated expression of SIRT1 in BV2 cells under HS. Upon inhibition of SIRT1 expression, there was a corresponding increase in pro-inflammatory cytokine, iNOS, and ROS expression in BV2 cells. In vivo experiments with the SIRT1 agonist SRT-1720 showed a mitigation of neuron injury under HS, as assessed by Nissl and HE staining. Activation of SIRT1 was associated with a reduction in mitochondrial injury and a decrease in the phosphorylation of mitochondrial fission protein Drp1ser616. Furthermore, the heat-induced activation of microglia was reversed by the Drp1 inhibitor, Mdivi. ConclusionsOur findings provided evidence that SIRT1 played a crucial role in inhibiting heat stress-induced microglial activation. By suppressing the phosphorylation of mitochondrial fission protein Drp1, SIRT1 contributed to the reduction of neuroinflammation and severity of heatstroke-induced brain injury.

Melanin concentrating hormone regulates the JNK/ERK signaling pathway to alleviate influenza A virus infection-induced neuroinflammation

Melanin concentrating hormone (MCH) controls many brain functions, such as sleep/wake cycle and memory, and modulates the inflammation response. Previous studies have shown that influenza A virus (IAV) infection-induced neuroinflammation leads to central nervous damage. This study investigated the potential effects of MCH against neuroinflammation induced by IAV infection and its mechanism. MCH (1 and 2 mg/ml) was administrated for 5 consecutive days before IAV infection. Pentobarbital-induced sleep tests, an open-field test, and a Morris water maze were performed to measure sleep quality, spatial learning and memory ability. Neuronal loss and microglial activation were observed with Nissl staining and immunofluorescence assay. The levels of inflammatory cytokines and the expression of the JNK/ERK signaling pathway were examined by ELISA and western blot. IAV infection led to poor sleep quality, impaired the ability of spatial learning and memory, caused neuronal loss and microglial activation in mice’s hippocampus and cortex. Meanwhile the level of inflammatory cytokines increased, and the JNK/ERK signaling pathway was activated after IAV infection. MCH administration significantly alleviated IAV-induced neuroinflammation, cognitive impairment, and sleep disorder, decreased the levels of inflammatory cytokines, and inhibited neuronal loss and microglial activation in the hippocampus and cortex by regulating the JNK/ERK signaling pathway. Therefore, MCH alleviated the neuroinflammation, spatial learning and memory impairment, and sleep disorder in IAV-infected mice by regulating the JNK/ERK signaling pathway.

Regular exercise ameliorates high-fat diet-induced depressive-like behaviors by activating hippocampal neuronal autophagy and enhancing synaptic plasticity

Exercise enhances synaptic plasticity and alleviates depression symptoms, but the mechanism through which exercise improves high-fat diet-induced depression remains unclear. In this study, 6-week-old male C57BL/6J mice were administered a high-fat diet (HFD, 60% kcal from fat) to a HFD model for 8 weeks. The RUN group also received 1 h of daily treadmill exercise in combination with the HFD. Depressive-like behaviors were evaluated by behavioral assessments for all groups. The key mediator of the effect of exercise on high-fat diet-induced depressive-like behaviors was detected by RNA-seq. The morphology and function of the neurons were evaluated via Nissl staining, Golgi staining, electron microscopy and electrophysiological experiments. The results showed that exercise attenuated high-fat diet-induced depressive-like behavior and reversed hippocampal gene expression changes. RNA-seq revealed Wnt5a, which was a key mediator of the effect of exercise on high-fat diet-induced depressive-like behaviors. Further work revealed that exercise significantly activated neuronal autophagy in the hippocampal CA1 region via the Wnt5a/CamkII signaling pathway, which enhanced synaptic plasticity to alleviate HFD-induced depressive-like behavior. However, the Wnt5a inhibitor Box5 suppressed the ameliorative effects of exercise. Therefore, this work highlights the critical role of Wnt5a, which is necessary for exercise to improve high-fat diet-induced depression.

Low-frequency rTMS Plays a Neuroprotective role in Pilocarpine-induced Status Epilepticus Rat Models Through the AMPAR GluA1-STIM-Ca2+ Pathway.

Low-frequency repetitive transcranial magnetic stimulation (rTMS) refers to the stimulation of the brain using repetitive magnetic field pulses at a low frequency (≤ 1Hz) to reduce seizures. Currently, the mechanism is not well understood.Male Sprague-Dawley rats underwent pilocarpine-induced status epilepticus (SE) and were then stimulated with low-frequency rTMS. An epilepsy cell model was then established by incubating rat hippocampal neurons with Mg2+-free extracellular fluids. The effects of the low-frequency rTMS on epileptogenesis and hippocampal neuron injury were evaluated using a video electroencephalogram (vEEG) and Nissl staining, and the expression of AMPAR GluA1 and STIM in the hippocampus and hippocampal neurons was assessed using western blot and immunofluorescence. Additionally, the intracellular Ca2+ concentration and reactive oxygen species (ROS) were measured using flow cytometry.Low-frequency rTMS attenuated spontaneous recurrent seizures in rats with epilepsy, with the SE group exhibiting a higher incidence (100%) and frequency (3.00 ± 0.18 times/day) than the SE + 0.3 (50% incidence, 0.06 ± 0.03 times/day), SE + 0.5 (0.20 ± 0.02 times/day) and SE + 1Hz (1.02 ± 0.05 times/day) groups. Additionally, rTMS reduced the damage and apoptosis of hippocampal pyramidal neurons, increasing their numbers in the CA1 and CA3 regions. Furthermore, AMPAR GluA1 and STIM expression were upregulated in the hippocampus when using rTMS, reversing the downregulation caused by seizures. Immunofluorescence verified the increased fluorescence intensity of AMPAR GluA1 and STIM. Moreover, rTMS inhibited Ca2+ overload and ROS in epileptic neuron models.Low-frequency rTMS may exert neuroprotective effects through the AMPAR GluA1-STIM-Ca2+ pathway.

Mechanism of Treadmill Exercise Combined with Rich Environmental Stimulation to Improve Depression in Post-stroke Depression Model Rats.

Post-stroke depression (PSD) is a common complication, occurring in approximately one-third of these patients. The neurological symptoms of PSD affect patients' daily life and subsequent recovery. Analyzing the pathogenesis of post-stroke depression from a psychological perspective, it was found that PSD patients often feel despair and anxiety, and it is crucial to explore non-pharmacological ways to improve post-stroke depressive symptoms. A combination of exercise and rich environmental stimulation (RES) has been found effective in improving post-stroke depressive symptoms. Therefore, this study aimed to explore the effects of exercise and rich environmental stimulation on PSD in rats and their potential underlying mechanisms and to provide a theoretical basis for managing PSD. The PSD rat model was constructed, and the depression-like behaviors of rats in each group were evaluated using the open field test (OFT), sucrose preference test (SPT), and forced swimming test (FST). Moreover, changes in the morphological behavior of rat hippocampus were observed using hematoxylin-eosin (HE) staining and Nissl staining. The expression levels of 5-hydroxytryptamine (5-HT) and norepinephrine (NE) in hippocampus tissues were assessed using enzyme linked immunosorbent assay (ELISA), and the levels of tryptophan-related proteins were determined employing western blot analysis. Additionally, a kynurenine-3-monooxygenase (KMO) inhibitor was administered to the combined stimulation group, and the levels of tryptophan (TRP), 5-HT, kynurenine (KYN), 3-hydroxy-kynurenine (3-HK), and quinolinic acid (QA) were evaluated using liquid chromatography mass spectrometry/mass spectrometry (LC-MS/MS). Treadmill exercise combined with rich environmental stimulation significantly reduced the immobility time in the FST (p < 0.01), increased the exploratory behavior in the OFT (p < 0.05), and increased the sucrose water consumption in the SPT (p < 0.01), indicating that the depression-like behavior was improved. Treadmill exercise combined with rich environmental stimulation also improved the shape of the damaged hippocampus and increased the number of neurons in the hippocampus. Additionally, treadmill exercise combined with rich environmental stimulation significantly increased the levels of 5-HT and NE in hippocampus tissues (p < 0.01) and decreased KMO protein level (p < 0.01). In the KMO inhibitor group, the neural function was efficiently restored, the levels of 3-HK, QA, and KMO in the hippocampus were substantially reduced (p < 0.01), and the expression level of 5-HT was increased (p < 0.01). Exercise stimulation combined with enriched environmental stimuli alleviates post-stroke depression in rats, and the underlying mechanisms may be related to TRP/KYN/3-HK/QA excitotoxicity pathways and increased 5-hydroxytryptamine levels.

Electroacupuncture attenuates depressive-like behaviors in poststroke depression mice through promoting hippocampal neurogenesis and inhibiting TLR4/NF-κB/NLRP3 signaling pathway.

The aim of this study was to investigate the impact and underlying molecular mechanisms of electroacupuncture on mice with poststroke depression (PSD). Mice were randomly allocated into sham, PSD, and electroacupuncture groups. Mice in the PSD and electroacupuncture groups underwent middle cerebral artery occlusion (MCAO) surgery following with sedentary behavior. Electroacupuncture targeting Zusanli (ST36) acupoint was performed 24 h after MCAO for 4 weeks in electroacupuncture group. The sucrose preference test, forced swimming test, open field test, tail suspension test, elevated plus maze, Catwalk analysis, RNA sequencing, Nissl staining, Golgi staining, TUNEL staining, Edu labeling, and doublecortin staining were performed. Lymphocyte subsets in peripheral blood and the levels of IL-1β, IL-6, TNF-α, and expression of Iba1/CD86, Iba1/NLRP3, TLR4/p38/NF-κB/NLRP3 pathways in the hippocampus were detected. Electroacupuncture effectively protected against the development of depression-like symptoms. The number of granulosa cells and doublecortin-positive cells in the dentate gyrus (DG) were significantly decreased in PSD group, which were significantly upregulated ( P < 0.01) by electroacupuncture. Electroacupuncture also significantly reduced ( P < 0.05) TUNEL-positive cells in the DG and CA1. RNA-seq revealed that electroacupuncture may exert antidepressant effect by regulating the inflammation mediated by TLR4/NF-κB/NLRP3 pathway in hippocampus. Electroacupuncture remarkably elevated ( P < 0.01) the ratio of CD4+ to CD8+ T cells and percentage of CD3-CD49b+ cells in CD45+CD49b+ cells in the peripheral blood. Electroacupuncture significantly reduced ( P < 0.05) the high levels of IL-1β, IL-6, TNF-α, iba1, TLR4, p-p38, p-NF-κB, and NLRP3 and sedentary behavior. Electroacupuncture was observed to mitigate depression symptoms and increase hippocampal neurogenesis in mice with PSD, possibly by inhibiting TLR4/p38/NF-κB/NLRP3 pathways and improving the microglia-mediated inflammatory microenvironment in the hippocampus.

Curcumin activates the Wnt/β-catenin signaling pathway to alleviate hippocampal neurogenesis abnormalities caused by intermittent hypoxia: A study based on network pharmacology and experimental verification

The purpose of this work was to investigate how curcumin (Cur) might enhance cognitive function and to gain a better understanding of the molecular mechanisms behind Cur’s impacts on neurogenesis deficits brought on by intermittent hypoxia (IH). Using network pharmacology, we explored possible targets for Cur’s obstructive sleep apnea (OSA) therapy. We established an IH model using C57BL/6 mice and c17.2 cells, and we assessed the influence of Cur on treatment outcomes as well as the effect of IH on cognitive function. Hippocampal damage and neurogenesis, as well as expression of core targets, were then examined. Network pharmacology analysis revealed that Cur has the potential for multi-target, multi-pathway therapy, with CTNNB1 and MYC as core target genes. The Morris water maze test showed that Cur (100 mg/kg, intragastrically) significantly improved cognitive dysfunction induced by IH. The hematoxylin and eosin (H&E) and Nissl staining indicated that Cur could alleviate damage to the hippocampus caused by IH. Immunohistochemistry, immunofluorescence, and western blotting results showed that Cur might promote neurogenesis and upregulate the expression of β-catenin and c-myc. In vitro, Cur (0.5 μM) has a protective effect on IH-induced neural stem cells (NSCs) injury and apoptosis and can restore the Wnt/β-catenin. Cur significantly increased the neurogenesis via the Wnt/β-catenin pathway, providing the scientific groundwork for the development of new treatment strategies for neurological damage linked to OSA.