Knowns and unknowns of TiLV-associated neuronal disease

Tilapia Lake Virus (TiLV) is associated with pathological changes in the brain of infected fish, but the mechanisms driving the virus's neuropathogenesis remain poorly characterized. TiLV establishes a persistent infection in the brain of infected fish even when the virus is no longer detectable in the peripheral organs, rendering therapeutic interventions and disease management challenging. Moreover, the persistence of the virus in the brain may pose a risk for viral reinfection and spread and contribute to ongoing tissue damage and neuroinflammatory processes. In this review, we explore TiLV-associated neurological disease. We discuss the possible mechanism(s) used by TiLV to enter the central nervous system (CNS) and examine TiLV-induced neuroinflammation and brain immune responses. Lastly, we discuss future research questions and knowledge gaps to be addressed to significantly advance this field.

JNK3 inhibitors as promising pharmaceuticals with neuroprotective properties

The intensive study and investigation of neuroprotective therapy for central nervous system (CNS) diseases is ongoing. Due to shared mechanisms of neurodegeneration, a neuroprotective approach might offer benefits across multiple neurological disorders, despite variations in symptoms or injuries. C-Jun N-terminal Kinase 3 (JNK3) is found primarily in the CNS and is involved in physiological processes such as brain development, synapse formation, and memory formation. The potential of JNK3 as a target for pharmacological development holds promise for advancing neuroprotective therapies. Developing small molecule JNK3 inhibitors into drugs with neuroprotective qualities could facilitate neuronal restoration and self-repair. This review focuses on elucidating key neuroprotective mechanisms, exploring the interplay between neurodegenerative diseases and neuroprotection, and discussing advancements in JNK3 inhibitor drug development.

Gut-brain axis interplay via STAT3 pathway: Implications of Helicobacter pylori derived secretome on inflammation and Alzheimer's disease

Helicobacter pylori is a pathogenic bacterium that causes gastritis and gastric carcinoma. Besides gastric complications its potential link with gut-brain axis disruption and neurological disorders has also been reported. The current study investigated the plausible role and its associated molecular mechanism underlying H. pylori mediated gut-brain axis disruption and neuroinflammation leading to neurological modalities like Alzheimer's disease (AD). We have chosen the antimicrobial resistant and susceptible H. pylori strains on the basis of broth dilution method. We have observed the increased inflammatory response exerted by H. pylori strains in the gastric as well as in the neuronal compartment after treatment with Helicobacter pylori derived condition media (HPCM). Further, elevated expression of STAT1, STAT3, and AD-associated proteins- APP and APOE4 was monitored in HPCM-treated neuronal and neuron-astrocyte co-cultured cells. Excessive ROS generation has been found in these cells. The HPCM treatment to LN229 causes astrogliosis, evidenced by increased glial fibrillary acidic protein. Our results indicate the association of STAT3 as an important regulator in the H. pylori-mediated pathogenesis in neuronal cells. Notably, the inhibition of STAT3 by its specific inhibitor, BP-1-102, reduced the expression of pSTAT3 and AD markers in neuronal compartment induced by HPCM. Thus, our study demonstrates that H. pylori infection exacerbates inflammation in AGS cells and modulates the activity of STAT3 regulatory molecules. H. pylori secretome could affect neurological compartments by promoting STAT3 activation and inducing the expression of AD-associated signature markers. Further, pSTAT-3 inhibition mitigates the H. pylori associated neuroinflammation and amyloid pathology.

Assessment of blood-brain barrier leakage and brain oxygenation in Connexin-32 knockout mice with systemic neuroinflammation using pulse electron paramagnetic resonance imaging techniques

PURPOSE

The determination of blood-brain barrier (BBB) integrity and partial pressure of oxygen (pO2) in the brain is of substantial interest in several neurological applications. This study aimed to assess the feasibility of using trityl OX071-based pulse electron paramagnetic resonance imaging (pEPRI) to provide a quantitative estimate of BBB integrity and pO2 maps in mouse brains as a function of neuroinflammatory disease progression.

METHODS

Five Connexin-32 (Cx32)-knockout (KO) mice were injected with lipopolysaccharide to induce neuroinflammation for imaging. Three wild-type mice were also used to optimize the imaging procedure and as control animals. An additional seven Cx32-KO mice were used to establish the BBB leakage of trityl using the colorimetric assay. All pEPRI experiments were performed using a preclinical instrument, JIVA-25 (25 mT/720 MHz), at times t = 0, 4, and 6 h following lipopolysaccharide injection. Two pEPRI imaging techniques were used: (a) single-point imaging for obtaining spatial maps to outline the brain and calculate BBB leakage using the signal amplitude, and (b) inversion-recovery electron spin echo for obtaining pO2 maps.

RESULTS

A statistically significant change in BBB leakage was found using pEPRI with the progression of inflammation in Cx32 KO animals. However, the change in pO2 values with the progression of inflammation for these animals was not statistically significant.

CONCLUSIONS

For the first time, we show the ability of pEPRI to provide pO2 maps in mouse brains noninvasively, along with a quantitative assessment of BBB leakage. We expect this study to open new queries from the field to explore the pathology of many neurological diseases and provide a path to new treatments.

On neuroinflammation in Alzheimer's disease model amyloid-β (Aβ1-42)-peptide-induced astrocyte activation

One of the main pathological features noted in Alzheimer's disease (AD) is the presence of plagues of aggregated β-amyloid (Aβ1-42)-peptides. Excess deposition of amyloid-β oligomers (AβO) are known to promote neuroinflammation. Sequentially, following neuroinflammation astrocytes become activated with cellular characteristics to initiate activated astrocytes. The purpose of this study was to determine whether total flavonoids derived from Dracocephalum moldavica L. (TFDM) inhibited Aβ1-42-induced damage attributed to activated C8-D1A astrocytes. Western blotting and ELISA were used to determine the expression of glial fibrillary acidic protein (GFAP), and complement C3 to establish the activation status of astrocytes following induction from exposure to Aβ1-42. Data demonstrated that stimulation of C8-D1A astrocytes by treatment with 40 μM Aβ1-42 for 24 hr produced significant elevation in protein expression and protein levels of acidic protein (GFAP) and complement C3 accompanied by increased expression and levels of inflammatory cytokines. Treatment with TFDM or the clinically employed drug donepezil in AD therapy reduced production of inflammatory cytokines, and toxicity initiated following activation of C8-D1A astrocytes following exposure to Aβ1-42. Therefore, TFDM similar to donepezil inhibited inflammatory secretion in reactive astrocytes, suggesting that TFDM may be considered as a potential compound to be utilized in AD therapy.

Primary microglia cell cultures in translational research: Strengths and limitations

Microglia are the resident macrophages in the central nervous system, accounting for 10-15% of the cell mass in the brain. Next to their physiological role in development, monitoring neuronal function and the maintenance of homeostasis, microglia are crucial in the brain's immune defense. Brain injury and chronic neurological disorders are associated with neuroinflammation, in which microglia activation is a central element. Microglia acquire a wide spectrum of activation states in the diseased or injured brain, some of which are neurotoxic. The investigation of microglia (patho)physiology and therapeutic interventions targeting neuroinflammation is a substantial challenge. In addition to in vivo approaches, the application of in vitro model systems has gained significant ground and is essential to complement in vivo work. Primary microglia cultures have proved to be a useful tool. Microglia cultures have offered the opportunity to explore the mechanistic, molecular elements of microglia activation, the microglia secretome, and the efficacy of therapeutic treatments against neuroinflammation. As all model systems, primary microglia cultures have distinct strengths and limitations to be weighed when experiments are designed and when data are interpreted. Here, we set out to provide a succinct overview of the advantages and pitfalls of the use of microglia cultures, which instructs the refinement and further development of this technique to remain useful in the toolbox of microglia researchers. Since there is no conclusive therapy to combat neurotoxicity linked to neuroinflammation in acute brain injury or neurodegenerative disorders, these research tools remain essential to explore therapeutic opportunities.

Genetic deletion of astrocytic calcineurin B1 prevents cognitive impairment and neuropathology development in acute and chronic mouse models of Alzheimer's disease

Alzheimer's disease (AD) represents an urgent yet unmet challenge for modern society, calling for exploration of innovative targets and therapeutic approaches. Astrocytes, main homeostatic cells in the CNS, represent promising cell-target. Our aim was to investigate if deletion of the regulatory CaNB1 subunit of calcineurin in astrocytes could mitigate AD-related memory deficits, neuropathology, and neuroinflammation. We have generated two, acute and chronic, AD mouse models with astrocytic CaNB1 ablation (ACN-KO). In the former, we evaluated the ability of β-amyloid oligomers (AβOs) to impair memory and activate glial cells once injected in the cerebral ventricle of conditional ACN-KO mice. Next, we generated a tamoxifen-inducible astrocyte-specific CaNB1 knock-out in 3xTg-AD mice (indACNKO-AD). CaNB1 was deleted, by tamoxifen injection, in 11.7-month-old 3xTg-AD mice for 4.4 months. Spatial memory was evaluated using the Barnes maze; β-amyloid plaques burden, neurofibrillary tangle deposition, reactive gliosis, and neuroinflammation were also assessed. The acute model showed that ICV injected AβOs in 2-month-old wild type mice impaired recognition memory and fostered a pro-inflammatory microglia phenotype, whereas in ACN-KO mice, AβOs were inactive. In indACNKO-AD mice, 4.4 months after CaNB1 depletion, we found preservation of spatial memory and cognitive flexibility, abolishment of amyloidosis, and reduction of neurofibrillary tangles, gliosis, and neuroinflammation. Our results suggest that ACN is crucial for the development of cognitive impairment, AD neuropathology, and neuroinflammation. Astrocyte-specific CaNB1 deletion is beneficial for both the abolishment of AβO-mediated detrimental effects and treatment of ongoing AD-related pathology, hence representing an intriguing target for AD therapy.

Genetic insights into the relationship between immune cell characteristics and ischemic stroke: A bidirectional Mendelian randomization study

BACKGROUND AND PURPOSE

Ischemic stroke, a major contributor to global disability and mortality, is underpinned by intricate pathophysiological mechanisms, notably neuroinflammation and immune cell dynamics. Prior research has identified a nuanced and often paradoxical link between immune cell phenotypes and ischemic stroke susceptibility. The aim of this study was to elucidate the potential causal links between the median fluorescence intensity (MFI) and morphological parameters (MP) of 731 immune cell types and ischemic stroke risk.

METHODS

By analyzing extensive genetic datasets, we conducted comprehensive Mendelian randomization (MR) analyses to discern the genetic correlations between diverse immune cell attributes (MFI and MP) and ischemic stroke risk.

RESULTS

Our study identified key immune cell signatures linked to ischemic stroke risk. Both B cells and T cells, among other immune cell types, have a bidirectional influence on stroke risk. Notably, the regulatory T-cell phenotype demonstrates significant neuroprotective properties, with all odds ratio (OR) values and confidence intervals (CIs) being less than 1. Furthermore, CD39 phenotype immune cells, particularly CD39+ CD8+ T cells (inverse variance weighting [IVW] OR 0.92, 95% CI 0.87-0.97; p = 0.002) and CD39+ activated CD4 regulatory T cells (IVW OR 0.93, 95% CI 0.90-0.97; p < 0.001), show notable neuroprotection against ischemic stroke.

CONCLUSION

This investigation provides new genetic insights into the interplay between various immune cells and ischemic stroke, underscoring the complex role of immune processes in stroke pathogenesis. These findings lay a foundation for future research, which may confirm and expand upon these links, potentially leading to innovative immune-targeted therapies for stroke prevention and management.

Complete remission with histamine blocker in a patient with intractable hyperadrenergic postural orthostatic tachycardia syndrome secondary to long coronavirus disease syndrome

The COVID-19 pandemic caused by the novel severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), has emerged as a global public health concern and its sequels have barely started to outcrop. A good percentage of patients who suffered from COVID-19 are prone to develop long-COVID or post-COVID condition (PCC), a multisystemic, heterogeneous, chronic disorder. Patients with PCC may experience diverse manifestations, of which cardiovascular and neurological symptoms are among the most frequently reported. Indeed, dysautonomia presented as orthostatic intolerance has gained room following recent reports linking postural orthostatic tachycardia syndrome (POTS) with PCC. Disturbances in heart rate (HR) and blood pressure (BP) during postural changes are the cornerstones of orthostatic intolerance seen in patients suffering from PCC. A subtype of POTS, hyperadrenergic POTS, has been widely studied because of its association with mast cell activation syndrome (MCAS). Although a causative relationship between PCC, hyperadrenergic POTS, and MCAS remains unrevealed, these syndromes can overlap. We want to propose here a correlation produced by a close-loop mechanism with positive feedback established after SARS-CoV-2 infection in a previously healthy young patient.

Conditioned medium from human dental pulp stem cells treats spinal cord injury by inhibiting microglial pyroptosis

Human dental pulp stem cell transplantation has been shown to be an effective therapeutic strategy for spinal cord injury. However, whether the human dental pulp stem cell secretome can contribute to functional recovery after spinal cord injury remains unclear. In the present study, we established a rat model of spinal cord injury based on impact injury from a dropped weight and then intraperitoneally injected the rats with conditioned medium from human dental pulp stem cells. We found that the conditioned medium effectively promoted the recovery of sensory and motor functions in rats with spinal cord injury, decreased expression of the microglial pyroptosis markers NLRP3, GSDMD, caspase-1, and interleukin-1β, promoted axonal and myelin regeneration, and inhibited the formation of glial scars. In addition, in a lipopolysaccharide-induced BV2 microglia model, conditioned medium from human dental pulp stem cells protected cells from pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1β pathway. These results indicate that conditioned medium from human dental pulp stem cells can reduce microglial pyroptosis by inhibiting the NLRP3/caspase-1/interleukin-1β pathway, thereby promoting the recovery of neurological function after spinal cord injury. Therefore, conditioned medium from human dental pulp stem cells may become an alternative therapy for spinal cord injury.

Vincamine alleviates brain injury by attenuating neuroinflammation and oxidative damage in a mouse model of Parkinson's disease through the NF-κB and Nrf2/HO-1 signaling pathways

Parkinson's disease (PD) is a neurodegenerative disease featured by progressive loss of nigrostriatal dopaminergic neurons, the etiology of which is associated with the existence of neuroinflammatory response and oxidative stress. Vincamine is an indole alkaloid that was reported to exhibit potent anti-inflammatory and antioxidant properties in many central and/or peripheral diseases. Nevertheless, the specific role of vincamine in PD development remains unknown. In our study, dopaminergic neuron loss was determined through immunohistochemistry staining and western blot analysis of tyrosine hydroxylase (TH) expression in the substantia nigra (SN) of PD mice. Reactive oxygen species (ROS) production and malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) levels were detected through DHE staining and commercially available kits to assess oxidative stress. Pro-inflammatory cytokine (TNF-α, IL-1β, and IL-6) levels in the SN were measured via RT-qPCR and western blot analysis. Microglial and astrocyte activation was examined through immunofluorescence staining of Iba-1 (microglia marker) and GFAP (astrocyte marker) in the SN. The regulation of vincamine on the NF-κB and Nrf2/HO-1 pathway was estimated through western blot analysis. Our results showed that vincamine treatment decreased TNF-α, IL-1β, and IL-6 mRNA and protein levels, reduced GFAP and Iba-1 expression, decreased ROS production and MDA level, and increased SOD activity and GSH level in the SN of PD mice. Mechanically, vincamine repressed the phosphorylation levels of p65, IKKβ, and IκBα but enhanced the protein levels of Nrf2 and HO-1 in PD mice. Collectively, vincamine plays a neuroprotective role in PD mouse models by alleviating neuroinflammation and oxidative damage via suppressing the NF-κB pathway and activating the Nrf2/HO-1 pathway.

Detection of Neuroinflammation Induced by Typhoid Vaccine Using Quantitative Magnetization Transfer MR: A Randomized Crossover Study

BACKGROUND

The role of neuroinflammation in psychiatric disorders is not well-elucidated. A noninvasive technique sensitive to low-level neuroinflammation may improve understanding of the pathophysiology of these conditions.

PURPOSE

To test the ability of quantitative magnetization transfer (QMT) MR at 3 T for detection of low-level neuroinflammation induced by typhoid vaccine within a clinically reasonable scan time.

STUDY TYPE

Randomized, crossover, placebo-controlled.

SUBJECTS

Twenty healthy volunteers (10 males; median age 34 years).

FIELD STRENGTH/SEQUENCE

Magnetization prepared rapid gradient-echo and MT-weighted 3D fast low-angle shot sequences at 3 T.

ASSESSMENT

Participants were randomized to either vaccine or placebo first with imaging, then after a washout period received the converse with a second set of imaging. MT imaging, scan time, and blood-based inflammatory marker concentrations were assessed pre- and post-vaccine and placebo. Mood was assessed hourly using the Profile of Mood States questionnaire. QMT parameter maps, including the exchange rate from bound to free pool (kba) were generated using a two-pool model and then segmented into tissue type.

STATISTICAL TESTS

Voxel-wise permutation-based analysis examined inflammatory-related alterations of QMT parameters. The threshold-free cluster enhancement method with family-wise error was used to correct voxel-wise results for multiple comparisons. Region of interest averages were fed into mixed models and Bonferroni corrected. Spearman correlations assessed the relationship between mood scores and QMT parameters. Results were considered significant if corrected P < 0.05.

RESULTS

Scan time for the MT-weighted acquisition was approximately 11 minutes. Blood-based analysis showed higher IL-6 concentrations post-vaccine compared to post-placebo. Voxel-wise analysis found three clusters indicating an inflammatory-mediated increase in kba in cerebellar white matter. Cerebellar kba for white matter was negatively associated with vigor post-vaccine but not post-placebo.

DATA CONCLUSION

This study suggested that QMT at 3 T may show some sensitivity to low-level neuroinflammation. Further studies are needed to assess the viability of QMT for use in inflammatory-based disorders.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

Autophagy dysregulation plays a crucial role in regulatory T-cell loss and neuroinflammation in amyotrophic lateral sclerosis (ALS)

OBJECTIVE

Neuroinflammation is the hallmark of amyotrophic lateral sclerosis (ALS) disease. Regulatory T cells (Tregs) are essential in immune tolerance and neuroinflammation prevention. It has been shown that a significant decrease in Treg and FoxP3 protein expression is observed in ALS patients. The main reason for the FoxP3+ Treg loss in ALS is unknown. In this study, the role of autophagy dysregulation in FoxP3+ Tregs in ALS was investigated.

METHODS

Twenty-three ALS patients and 24 healthy controls were recruited for the study. Mononuclear cells (MNCs) were obtained from peripheral blood, and then Tregs were isolated. Isolated Tregs were stained with FoxP3 and LC3 antibodies and analyzed in flow cytometry to determine autophagy levels in FoxP3+ Tregs in patients and controls.

RESULTS

The mean of FoxP3+ LC3+ cells, were 0.47 and 0.45 in patients and controls, respectively. The mean of FoxP3+ LC3- cells was 0.15 in patients and 0.20 in controls, p = 0.030 (p < 0.05). There is no significant correlation between ALSFRS-R decay rate and autophagy level in patients. Also, there is no significant difference between autophagy levels in FoxP3+ Tregs in patients with rapidly progressing ALS and slow-progressing ALS.

CONCLUSION

Excessive autophagy levels in FoxP3+ Tregs in ALS patients can potentially be an explanation for an increased cell death and result in worsened neuroinflammation and disease onset. However, the disease progress is not attributable to autophagy levels in FoxP3+ Tregs.

Human Motor Neurons Elicit Pathological Hallmarks of ALS and Reveal Potential Biomarkers of the Disease in Response to Prolonged IFNγ Exposure

Amyotrophic lateral sclerosis (ALS) is a debilitating neurodegenerative disorder marked by progressive motor neuron degeneration and muscle denervation. A recent transcriptomic study integrating a wide range of human ALS samples revealed that the upregulation of p53, a downstream target of inflammatory stress, is commonly detected in familial and sporadic ALS cases by a mechanism linked to a transactive response DNA-binding protein 43 (TDP-43) dysfunction. In this study, we show that prolonged interferon-gamma (IFNγ) treatment of human induced pluripotent stem cell-derived spinal motor neurons results in a severe cytoplasmic aggregation of TDP-43. TDP-43 dysfunction resulting from either IFNγ exposure or an ALS-associated TDP-43 mutation was associated with the activation of the p53 pathway. This was accompanied by the hyperactivation of neuronal firing, followed by the complete loss of their electrophysiological function. Through a comparative single-cell transcriptome analysis, we have identified significant alterations in ALS-associated genes in motor neurons exposed to IFNγ, implicating their direct involvement in ALS pathology. Interestingly, IFNγ was found to induce significant levels of programmed death-ligand 1 (PD-L1) expression in motor neurons without affecting the levels of any other immune checkpoint proteins. This finding suggests a potential role of excessive PD-L1 expression in ALS development, given that PD-L1 was recently reported to impair neuronal firing ability in mice. Our findings suggest that exposing motor neurons to IFNγ could directly derive ALS pathogenesis, even without the presence of the inherent genetic mutation or functional glia component. Furthermore, this study provides a comprehensive list of potential candidate genes for future immunotherapeutic targets with which to treat sporadic forms of ALS, which account for 90% of all reported cases.

Prophylactic Administration of Gut Microbiome Metabolites Abrogated Microglial Activation and Subsequent Neuroinflammation in an Experimental Model of Japanese Encephalitis

Short-chain fatty acids (SCFAs) are gut microbial metabolic derivatives produced during the fermentation of ingested complex carbohydrates. SCFAs have been widely regarded to have a potent anti-inflammatory and neuro-protective role and have implications in several disease conditions, such as, inflammatory bowel disease, type-2 diabetes, and neurodegenerative disorders. Japanese encephalitis virus (JEV), a neurotropic flavivirus, is associated with life threatening neuro-inflammation and neurological sequelae in infected hosts. In this study, we hypothesize that SCFAs have potential in mitigating JEV pathogenesis. Postnatal day 10 BALB/c mice were intraperitoneally injected with either a SCFA mixture (acetate, propionate, and butyrate) or PBS for a period of 7 days, followed by JEV infection. All mice were observed for onset and progression of symptoms. The brain tissue was collected upon reaching terminal illness for further analysis. SCFA-supplemented JEV-infected mice (SCFA + JEV) showed a delayed onset of symptoms, lower hindlimb clasping score, and decreased weight loss and increased survival by 3 days (p < 0.0001) upon infection as opposed to the PBS-treated JEV-infected animals (JEV). Significant downregulation of inflammatory cytokines TNF-α, MCP-1, IL-6, and IFN-Υ in the SCFA + JEV group relative to the JEV-infected control group was observed. Inflammatory mediators, phospho-NF-kB (P-NF-kB) and iba1, showed 2.08 ± 0.1 and 3.132 ± 0.43-fold upregulation in JEV versus 1.19 ± 0.11 and 1.31 ± 0.11-fold in the SCFA + JEV group, respectively. Tissue section analysis exhibited reduced glial activation (JEV group─42 ± 2.15 microglia/ROI; SCFA + JEV group─27.07 ± 1.8 microglia/ROI) in animals that received SCFA supplementation prior to infection as seen from the astrocytic and microglial morphometric analysis. Caspase-3 immunoblotting showed 4.08 ± 1.3-fold upregulation in JEV as compared to 1.03 ± 0.14-fold in the SCFA + JEV group and TUNEL assay showed a reduced cellular death post-JEV infection (JEV-6.4 ± 1.5 cells/ROI and SCFA + JEV-3.7 ± 0.73 cells/ROI). Our study critically contributes to the increasing evidence in support of SCFAs as an anti-inflammatory and neuro-protective agent, we further expand its scope as a potential supplementary intervention in JEV-mediated neuroinflammation.

Dl-3-n-Butylphthalide Improves Stroke Outcomes after Focal Ischemic Stroke in Mouse Model by Inhibiting the Pyroptosis-regulated Cell Death and Ameliorating Neuroinflammation

Recent studies have highlighted the involvement of pyroptosis-mediated cell death and neuroinflammation in ischemic stroke (IS) pathogenesis. DL-3-n-butylphthalide (NBP), a synthesized compound based on an extract from seeds of Apium graveolens, possesses a broad range of biological effects. However, the efficacy and the underlying mechanisms of NBP in IS remain contentious. Herein, we investigated the therapeutic effects of NBP and elucidated its potential mechanisms in neuronal cell pyroptosis and microglia inflammatory responses. Adult male mice underwent permanent distal middle cerebral artery occlusion (dMCAO), followed by daily oral gavage of NBP (80mg/kg) for 1, 7, or 21 consecutive days. Gene Expression Omnibus (GEO) dataset of IS patients peripheral blood RNA sequencing was analyzed to identify differentially expressed pyroptosis-related genes (PRGs) during the ischemic process. Our results suggested that NBP treatment effectively alleviated brain ischemic damage, resulting in decreased neurological deficit scores, reduced infarct volume, and improved neurological and behavioral functions. RNA sequence data from human unveiled upregulated PRGs in IS. Subsequently, we observed that NBP downregulated pyroptosis-associated markers at days 7 and 21 post-modeling, at both the protein and mRNA levels. Additionally, NBP suppressed the co-localization of pyroptosis markers with neuronal cells to variable degrees and simultaneously mitigated the accumulation of activated microglia. Overall, our data provide novel evidence that NBP treatment significantly attenuates ischemic brain damage and promotes recovery of neurological function in the early and recovery phases after IS, probably by negatively regulating the pyroptosis cell death of neuronal cells and inhibiting toxic neuroinflammation in the central nervous system.

Single administration of a psychedelic [(R)-DOI] influences coping strategies to an escapable social stress

Psychedelic compounds have potentially rapid, long-lasting anxiolytic, antidepressive and anti-inflammatory effects. We investigated whether the psychedelic compound (R)-2,5-dimethoxy-4-iodoamphetamine [(R)-DOI], a selective 5-HT2A receptor partial agonist, decreases stress-related behavior in male mice exposed to repeated social aggression. Additionally, we explored the likelihood that these behavioral changes are related to anti-inflammatory properties of [(R)-DOI]. Animals were subjected to the Stress Alternatives Model (SAM), an escapable social stress paradigm in which animals develop reactive coping strategies - remaining in the SAM arena (Stay) with a social aggressor, or dynamically initiated stress coping strategies that involve utilizing the escape holes (Escape) to avoid aggression. Mice expressing these behavioral phenotypes display behaviors like those in other social aggression models that separate animals into stress-vulnerable (as for Stay) or stress-resilient (as for Escape) groups, which have been shown to have distinct inflammatory responses to social stress. These results show that Stay animals have heightened cytokine gene expression, and both Stay and Escape mice exhibit plasma and neural concentrations of the inflammatory cytokine tumor necrosis factor-α (TNFα) compared to unstressed control mice. Additionally, these results suggest that a single administration of (R)-DOI to Stay animals in low doses, can increase stress coping strategies such as increasing attention to the escape route, promoting escape behavior, and reducing freezing during socially aggressive interaction in the SAM. Lower single doses (R)-DOI, in addition to shifting behavior to suggest anxiolytic effects but also concomitantly to reduce the plasma and limbic brain levels of the inflammatory cytokine TNFα.

Neuroprotective and anti-inflammatory effects of curcumin in Alzheimer's disease: Targeting neuroinflammation strategies

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by the accumulation of amyloid-beta plaques and neurofibrillary tangles, leading to neuronal loss. Curcumin, a polyphenolic compound derived from Curcuma longa, has shown potential neuroprotective effects due to its anti-inflammatory and antioxidant properties. This review aims to synthesize current preclinical data on the anti-neuroinflammatory mechanisms of curcumin in the context of AD, addressing its pharmacokinetics, bioavailability, and potential as a therapeutic adjunct. An exhaustive literature search was conducted, focusing on recent studies within the last 10 years related to curcumin's impact on neuroinflammation and its neuroprotective role in AD. The review methodology included sourcing articles from specialized databases using specific medical subject headings terms to ensure precision and relevance. Curcumin demonstrates significant neuroprotective properties by modulating neuroinflammatory pathways, scavenging reactive oxygen species, and inhibiting the production of pro-inflammatory cytokines. Despite its potential, challenges remain regarding its limited bioavailability and the scarcity of comprehensive human clinical trials. Curcumin emerges as a promising therapeutic adjunct in AD due to its multimodal neuroprotective benefits. However, further research is required to overcome challenges related to bioavailability and to establish effective dosing regimens in human subjects. Developing novel delivery systems and formulations may enhance curcumin's therapeutic potential in AD treatment.

Piezo1 Knockout Improves Post-Stroke Cognitive Dysfunction by Inhibiting the Interleukin-6 (IL-6)/Glutathione Peroxidase 4 (GPX4) Pathway

Background

Cerebral infarction often results in post-stroke cognitive impairment, which impairs the quality of life and causes long-term disability. Astrocytes, the most abundant glial cells in the central nervous system, have a crucial role in cerebral ischemia and neuroinflammation. We explored the possible advantages of interleukin-6 (IL-6), a powerful pro-inflammatory cytokine produced by astrocytes, for post-stroke cognitive function.

Methods

Mendelian randomization was applied to analyze the GWAS database of stroke patients, obtaining a causal relationship between IL-6 and stroke. Further validation of this relationship and its mechanisms was conducted. Using a mouse model of cerebral infarction, we demonstrated a significant increase in IL-6 expression in astrocytes surrounding the ischemic lesion. This protective effect of Piezo1 knockout was attributed to the downregulation of matrix metalloproteinases and upregulation of tight junction proteins, such as occludin and zonula occludens-1 (ZO-1).

Results

Two-step Mendelian randomization revealed that IL-6 exposure is a risk factor for stroke. Moreover, we conducted behavioral assessments and observed that Piezo1 knockout mice that received intranasal administration of astrocyte-derived IL-6 showed notable improvement in cognitive function compared to control mice. This enhancement was associated with reduced neuronal cell death and suppressed astrocyte activation, preserving ZO-1.

Conclusion

Our study shows that astrocyte-derived IL-6 causes cognitive decline after stroke by protecting the blood-brain barrier. This suggests that piezo1 knockout may reduce cognitive impairment after brain ischemia. Further research on the mechanisms and IL-6 delivery methods may lead to new therapies for post-stroke cognition.

The effects of hyaluronan and proteoglycan link protein 1 (HAPLN1) in ameliorating spinal cord injury mediated by Nrf2

Excessive inflammatory response and oxidative stress (OS) play an important role in the pathogenesis of spinal cord injury (SCI). Balance of inflammation and prevention of OS have been considered an effective strategy for the treatment of SCI. Hyaluronan and proteoglycan link protein 1 (HAPLN1), also known as cartilage link protein, has displayed a wide range of biological and physiological functions in different types of tissues and cells. However, whether HAPLN1 regulates inflammation and OS during SCI is unknown. Therefore, we aimed to examine whether HAPLN1 can have a protective effect on SCI. In this study, both in vitro and in vivo SCI models were established. Nissl staining and terminal deoxynucleotidyl transferase dUTP nick end labeling staining assays were used. Western blotting and enzyme-linked immunosorbent assay were employed to assess the expression of proteins. Our results demonstrate that the administration of HAPLN1 promoted the recovery of motor neurons after SCI by increasing the Basso mouse scale score, increasing the numbers of motor neurons, and preventing apoptosis of spinal cord cells. Additionally, HAPLN1 mitigated OS in spinal cord tissue after SCI by increasing the content of superoxide dismutase SOD and the activity of glutathione peroxidase but reducing the levels of malondialdehyde. Importantly, we found that HAPLN1 stimulated the activation of the nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway and stimulated the expression of heme oxygenase-1 and nicotinamide adenine dinucleotide phosphate quinone oxidoreductase-1, which mediated the attenuation of HAPLN1 in activation of the NOD-like receptor protein 3 (NLRP3) inflammasome by reducing the levels of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), caspase-1, and interleukin-1β. Correspondingly, in vitro experiments show that the presence of HAPLN1 suppressed the NLRP3 inflammasome and prevented cell injury against H2O2 in PC12 cells. These effects were mediated by the Nrf2/ARE pathway, and inhibition of Nrf2 with ML385 abolished the beneficial effects of HAPLN1. Based on these findings, we conclude that HAPLN1 inhibits the NLRP3 inflammasome through the stimulation of the Nrf2/ARE pathway, thereby suppressing neuroinflammation, enhancing motor neuronal survival, and improving the recovery of nerve function after SCI.

FBL Promotes LPS-Induced Neuroinflammation by Activating the NF-κB Signaling Pathway

Purpose

Neuroinflammation occurs in response to central nervous system (CNS) injury, infection, stimulation by toxins, or autoimmunity. We previously analyzed the downstream molecular changes in HT22 cells (mouse hippocampal neurons) upon lipopolysaccharide (LPS) stimulation. We detected elevated expression of Fibrillarin (FBL), a nucleolar methyltransferase, but the associated proinflammatory mechanism was not systematically elucidated. The aim of this study was to investigate the underlying mechanisms by which FBL affects neuroinflammation.

Methods

RT-real-time PCR, Western blotting and immunofluorescence were used to assess the mRNA and protein expression of FBL in HT22 cells stimulated with LPS, as well as the cellular localization and fluorescence intensity of FBL. BAY-293 (a son of sevenless homolog 1 (SOS1) inhibitor), SR11302 (an activator protein-1 (AP-1) inhibitor) and KRA-533 (a KRAS agonist) were used to determine the molecular mechanisms underlying the effect of FBL. AP-1 was predicted to be the target protein of FBL by molecular docking analysis, and validation was performed with T-5224 (an AP-1 inhibitor). In addition, the downstream signaling pathways of FBL were identified by transcriptome sequencing and verified by RT-real-time PCR.

Results

LPS induced FBL mRNA and protein expression in HT22 cells. In-depth mechanistic studies revealed that when we inhibited c-Fos, AP-1, and SOS1, FBL expression decreased, whereas FBL expression increased when KRAS agonists were used. In addition, the transcript levels of inflammatory genes in the NF-kB signaling pathway (including CD14, MYD88, TNF, TRADD, and NFKB1) were elevated after the overexpression of FBL.

Conclusion

LPS induced the expression of FBL in HT22 cells through the RAS/MAPK signaling pathway, and FBL further activated the NF-kB signaling pathway, which promoted the expression of relevant inflammatory genes and the release of cytokines. The present study reveals the mechanism by which FBL promotes neuroinflammation and offers a potential target for the treatment of neuroinflammation.

Biofilm exopolysaccharides alter sensory-neuron-mediated sickness during lung infection

Infections of the lung cause observable sickness thought to be secondary to inflammation. Signs of sickness are crucial to alert others via behavioral-immune responses to limit contact with contagious individuals. Gram-negative bacteria produce exopolysaccharide (EPS) that provides microbial protection; however, the impact of EPS on sickness remains uncertain. Using genome-engineered Pseudomonas aeruginosa (P. aeruginosa) strains, we compared EPS-producers versus non-producers and a virulent Escherichia coli (E. coli) lung infection model in male and female mice. EPS-negative P. aeruginosa and virulent E. coli infection caused severe sickness, behavioral alterations, inflammation, and hypothermia mediated by TLR4 detection of the exposed lipopolysaccharide (LPS) in lung TRPV1+ sensory neurons. However, inflammation did not account for sickness. Stimulation of lung nociceptors induced acute stress responses in the paraventricular hypothalamic nuclei by activating corticotropin-releasing hormone neurons responsible for sickness behavior and hypothermia. Thus, EPS-producing biofilm pathogens evade initiating a lung-brain sensory neuronal response that results in sickness.

Cellular architecture of evolving neuroinflammatory lesions and multiple sclerosis pathology

Multiple sclerosis (MS) is a neurological disease characterized by multifocal lesions and smoldering pathology. Although single-cell analyses provided insights into cytopathology, evolving cellular processes underlying MS remain poorly understood. We investigated the cellular dynamics of MS by modeling temporal and regional rates of disease progression in mouse experimental autoimmune encephalomyelitis (EAE). By performing single-cell spatial expression profiling using in situ sequencing (ISS), we annotated disease neighborhoods and found centrifugal evolution of active lesions. We demonstrated that disease-associated (DA)-glia arise independently of lesions and are dynamically induced and resolved over the disease course. Single-cell spatial mapping of human archival MS spinal cords confirmed the differential distribution of homeostatic and DA-glia, enabled deconvolution of active and inactive lesions into sub-compartments, and identified new lesion areas. By establishing a spatial resource of mouse and human MS neuropathology at a single-cell resolution, our study unveils the intricate cellular dynamics underlying MS.

Activating transcription factor 6 alleviates secondary brain injury by increasing cystathionine γ-lyase expression in a rat model of intracerebral hemorrhage

BACKGROUND

Intracerebral hemorrhage (ICH) comprises primary and secondary injuries, the latter of which induces increased inflammation and apoptosis and is more severe. Activating transcription factor 6 (ATF6) is a type-II transmembrane protein in the endoplasmic reticulum (ER). ATF6 target genes could improve ER homeostasis, which contributes to cryoprotection. Hence, we predict that ATF6 will have a protective effect on brain tissue after ICH.

METHOD

The ICH rat model was generated through autologous blood injection into the right basal ganglia, the expression of ATF6 after ICH was determined by WB and IF. The expression of ATF6 was effectively controlled by means of intervention, and a series of measures was used to detect cell death, neuroinflammation, brain edema, blood-brain barrier and other indicators after ICH. Finally, the effects on long-term neural function of rats were measured by behavioral means.

RESULT

ATF6 was significantly increased in the ICH-induced brain tissues. Further, ATF6 was found to modulate the expression of cystathionine γ-lyase (CTH) after ICH. Upregulation of ATF6 attenuated neuronal apoptosis and inflammation in ICH rats, along with mitigation of ICH-induced brain edema, blood-brain barrier deterioration, and cognitive behavior defects. Conversely, ATF6 genetic knockdown induced effects counter to those aforementioned.

CONCLUSIONS

This study thereby emphasizes the crucial role of ATF6 in secondary brain injury in response to ICH, indicating that ATF6 upregulation may potentially ameliorate ICH-induced secondary brain injury. Consequently, ATF6 could serve as a promising therapeutic target to alleviate clinical ICH-induced secondary brain injuries.

Innovative Approaches to Alzheimer's Therapy: Harnessing the Power of Heterocycles, Oxidative Stress Management, and Nanomaterial Drug Delivery System

Alzheimer's disease (AD) presents a complex pathology involving amyloidogenic proteolysis, neuroinflammation, mitochondrial dysfunction, and cholinergic deficits. Oxidative stress exacerbates AD progression through pathways like macromolecular peroxidation, mitochondrial dysfunction, and metal ion redox potential alteration linked to amyloid-beta (Aβ). Despite limited approved medications, heterocyclic compounds have emerged as promising candidates in AD drug discovery. This review highlights recent advancements in synthetic heterocyclic compounds targeting oxidative stress, mitochondrial dysfunction, and neuroinflammation in AD. Additionally, it explores the potential of nanomaterial-based drug delivery systems to overcome challenges in AD treatment. Nanoparticles with heterocyclic scaffolds, like polysorbate 80-coated PLGA and Resveratrol-loaded nano-selenium, show improved brain transport and efficacy. Micellar CAPE and Melatonin-loaded nano-capsules exhibit enhanced antioxidant properties, while a tetra hydroacridine derivative (CHDA) combined with nano-radiogold particles demonstrates promising acetylcholinesterase inhibition without toxicity. This comprehensive review underscores the potential of nanotechnology-driven drug delivery for optimizing the therapeutic outcomes of novel synthetic heterocyclic compounds in AD management. Furthermore, the inclusion of various promising heterocyclic compounds with detailed ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) data provides valuable insights for planning the development of novel drug delivery treatments for AD.

The Influence of Myeloid-Derived Suppressor Cell Expansion in Neuroinflammation and Neurodegenerative Diseases

The neuro-immune axis has a crucial function both during physiological and pathological conditions. Among the immune cells, myeloid-derived suppressor cells (MDSCs) exert a pivotal role in regulating the immune response in many pathological conditions, influencing neuroinflammation and neurodegenerative disease progression. In chronic neuroinflammation, MDSCs could lead to exacerbation of the inflammatory state and eventually participate in the impairment of cognitive functions. To have a complete overview of the role of MDSCs in neurodegenerative diseases, research on PubMed for articles using a combination of terms made with Boolean operators was performed. According to the search strategy, 80 papers were retrieved. Among these, 44 papers met the eligibility criteria. The two subtypes of MDSCs, monocytic and polymorphonuclear MDSCs, behave differently in these diseases. The initial MDSC proliferation is fundamental for attenuating inflammation in Alzheimer's disease (AD), Parkinson's disease (PD), and multiple sclerosis (MS), but not in amyotrophic lateral sclerosis (ALS), where MDSC expansion leads to exacerbation of the disease. Moreover, the accumulation of MDSC subtypes in distinct organs changes during the disease. The proliferation of MDSC subtypes occurs at different disease stages and can influence the progression of each neurodegenerative disorder differently.

Intranasal Delivery of Curcumin Nanoparticles Improves Neuroinflammation and Neurological Deficits in Mice with Intracerebral Hemorrhage

Intracerebral hemorrhage (ICH) represents one of the most severe subtypes of stroke. Due to the complexity of the brain injury mechanisms following ICH, there are currently no effective treatments to significantly improve patient functional outcomes. Curcumin, as a potential therapeutic agent for ICH, is limited by its poor water solubility and oral bioavailability. In this study, mPEG-PCL is used to encapsulate curcumin, forming curcumin nanoparticles, and utilized the intranasal administration route to directly deliver curcumin nanoparticles from the nasal cavity to the brain. By inhibiting pro-inflammatory neuroinflammation of microglia following ICH in mice, reprogramming pro-inflammatory microglia toward an anti-inflammatory function, and consequently reducing neuronal inflammatory death and hematoma volume, this approach improved blood-brain barrier damage in ICH mice and promoted the recovery of neurological function post-stroke. This study offers a promising therapeutic strategy for ICH to mediate neuroinflammatory microenvironments.

Transient Receptor Potential Ankyrin 1-dependent Activation of Extracellular Signal-regulated Kinase 2 in the Cerebral Cortices Contributes to Cortical Spreading Depolarization

Extracellular signal-regulated kinase (ERK) are serine/threonine-selective proteins and ERK1/2 can be phosphorylated in peripheral and central brain regions after cortical spreading depolarization (CSD) and calcitonin gene-related peptide; However, it remains unclear about whether and how ERK activity modulates CSD that correlates to migraine aura. Here, we determined the role of ERK in regulating CSD and explored the underlying mechanism involving transient receptor potential ankyrin 1 (TRPA1), a stress-sensing cation channel. CSD was recorded using intrinsic optical imaging in mouse brain slices, and electrophysiology in rats. Phosphorylated ERK (pERK1/2) and interleukin-1β (IL-1β) protein levels were detected using Western blot or enzyme-linked immunosorbent assay, respectively. IL-1β mRNA level was detected using qPCR. The results showed that an ERK inhibitor, SCH77298, markedly prolonged CSD latency and reduced propagation rate in mouse brain slices. Corresponding to this, CSD induction increased levels of cytosolic pERK1/2 in ipsilateral cerebral cortices of rats, the elevation of which correlated to the level of IL-1β mRNA. Mechanistic analysis showed that pre-treatment of an anti-TRPA1 antibody reduced the cytosolic pERK2 level but not pERK1 following CSD in cerebral cortices of rats and this level of pERK2 correlated with that of cerebral cortical IL-1β protein. Furthermore, an ERK activator, AES16-2M, but not its scrambled control, reversed the prolonged CSD latency by a TRPA1 inhibitor, HC-030031, in mouse brain slices. These data revealed a crucial role of ERK activity in regulating CSD, and elevation of pERK and IL-1β production induced by CSD is predominantly TRPA1 channel-dependent, thereby contributing to migraine pathogenesis.

Aging brain: exploring the interplay between bone marrow aging, immunosenescence, and neuroinflammation

Aging is a complex process characterized by a myriad of physiological changes, including alterations in the immune system termed immunosenescence. It exerts profound effects on both the bone marrow and the central nervous system, with significant implications for immunosenescence in neurological contexts. Our mini-review explores the complex relationship between bone marrow aging and its impact on immunosenescence, specifically within the context of neurological diseases. The bone marrow serves as a crucial hub for hematopoiesis and immune cell production, yet with age, it undergoes significant alterations, including alterations in hematopoietic stem cell function, niche composition, and inflammatory signaling. These age-related shifts in the bone marrow microenvironment contribute to dysregulation of immune cell homeostasis and function, impacting neuroinflammatory processes and neuronal health. In our review, we aim to explore the complex cellular and molecular mechanisms that link bone marrow aging to immunosenescence, inflammaging, and neuroinflammation, with a specific focus on their relevance to the pathophysiology of age-related neurological disorders. By exploring this interplay, we strive to provide a comprehensive understanding of how bone marrow aging impacts immune function and contributes to the progression of neurological diseases in aging individuals. Ultimately, this knowledge can hold substantial promise for the development of innovative therapeutic interventions aimed at preserving immune function and mitigating the progression of neurological disorders in the elderly population.

Fibroblast growth factor receptor inhibitors mitigate the neuropathogenicity of Borrelia burgdorferi or its remnants ex vivo

In previous studies, we showed that fibroblast growth factor receptors (FGFRs) contribute to inflammatory mediator output from primary rhesus microglia in response to live Borrelia burgdorferi. We also demonstrated that non-viable B. burgdorferi can be as pathogenic as live bacteria, if not more so, in both CNS and PNS tissues. In this study we assessed the effect of live and non-viable B. burgdorferi in inducing FGFR expression from rhesus frontal cortex (FC) and dorsal root ganglion (DRG) tissue explants as well as their neuronal/astrocyte localization. Specific FGFR inhibitors were also tested for their ability to attenuate inflammatory output and apoptosis in response to either live or non-viable organisms. Results show that in the FC, FGFR2 was the most abundantly expressed receptor followed by FGFR3 and FGFR1. Non-viable B. burgdorferi significantly upregulated FGFR3 more often than live bacteria, while the latter had a similar effect on FGFR1, although both treatments did affect the expressions of both receptors. FGFR2 was the least modulated in the FC tissues by the two treatments. FGFR1 expression was more prevalent in astrocytes while FGFR2 and FGFR3 showed higher expression in neurons. In the DRG, all three receptor expressions were also seen, but could not be distinguished from medium controls by immunofluorescence. Inhibition of FGFR1 by PD166866 downregulated both inflammation and apoptosis in both FC and DRG in response to either treatment in all the tissues tested. Inhibition of FGFR1-3 by AZD4547 similarly downregulated both inflammation and apoptosis in both FC and DRG in response to live bacteria, while with sonicated remnants, this effect was seen in one of the two FC tissues and 2 of 3 DRG tissues tested. CCL2 and IL-6 were the most downregulated mediators in the FC, while in the DRG it was CXCL8 and IL-6 in response to FGFR inhibition. Downregulation of at least two of these three mediators was observed to downregulate apoptosis levels in general. We show here that FGFR inhibition can be an effective anti-inflammatory treatment in antibiotic refractive neurological Lyme. Alternatively, two biologics may be needed to effectively curb neuroinflammation and pathology in the CNS and PNS.

Mast cell activation triggered by SARS-CoV-2 causes inflammation in brain microvascular endothelial cells and microglia

SARS-CoV-2-induced excessive inflammation in brain leads to damage of blood-brain barrier, hypoxic-ischemic injury, and neuron degeneration. The production of inflammatory cytokines by brain microvascular endothelial cells and microglia is reported to be critically associated with the brain pathology of COVID-19 patients. However, the cellular mechanisms for SARS-CoV-2-inducing activation of brain cells and the subsequent neuroinflammation remain to be fully delineated. Our research, along with others', has recently demonstrated that SARS-CoV-2-induced accumulation and activation of mast cells (MCs) in mouse lung could further induce inflammatory cytokines and consequent lung damages. Intracerebral MCs activation and their cross talk with other brain cells could induce neuroinflammation that play important roles in neurodegenerative diseases including virus-induced neuro-pathophysiology. In this study, we investigated the role of MC activation in SARS-CoV-2-induced neuroinflammation. We found that (1) SARS-CoV-2 infection triggered MC accumulation in the cerebrovascular region of mice; (2) spike/RBD (receptor-binding domain) protein-triggered MC activation induced inflammatory factors in human brain microvascular endothelial cells and microglia; (3) MC activation and degranulation destroyed the tight junction proteins in brain microvascular endothelial cells and induced the activation and proliferation of microglia. These findings reveal a cellular mechanism of SARS-CoV-2-induced neuroinflammation.

Platelet Dynamics in Neurodegenerative Disorders: Investigating the Role of Platelets in Neurological Pathology

Background: Neurological disorders, particularly those associated with aging, pose significant challenges in early diagnosis and treatment. The identification of specific biomarkers, such as platelets (PLTs), has emerged as a promising strategy for early detection and intervention in neurological health. This systematic review aims to explore the intricate relationship between PLT dynamics and neurological health, focusing on their potential role in cognitive functions and the pathogenesis of cognitive disorders. Methods: Adhering to PRISMA guidelines, a comprehensive search strategy was employed in the PubMed and Scholar databases to identify studies on the role of PLTs in neurological disorders published from 2013 to 2023. The search criteria included studies focusing on PLTs as biomarkers in neurological disorders, their dynamics, and their potential in monitoring disease progression and therapy effectiveness. Results: The systematic review included 104 studies, revealing PLTs as crucial biomarkers in neurocognitive disorders, acting as inflammatory mediators. The findings suggest that PLTs share common features with altered neurons, which could be utilised for monitoring disease progression and evaluating the effectiveness of treatments. PLTs are identified as significant biomarkers for detecting neurological disorders in their early stages and understanding the pathological events leading to neuronal death. Conclusions: The systematic review underscores the critical role of PLTs in neurological disorders, highlighting their potential as biomarkers for the early detection and monitoring of disease progression. However, it also emphasises the need for further research to solidify the use of PLTs in neurological disorders, aiming to enhance early diagnosis and intervention strategies.

Targeted-Neuroinflammation Mitigation Using Inflammasome-Inhibiting Nanoligomers is Therapeutic in an Experimental Autoimmune Encephalomyelitis Mouse Model

Multiple sclerosis (MS) is a debilitating autoimmune disease that impacts millions of patients worldwide, disproportionately impacting women (4:1), and often presenting at highly productive stages of life. This disease affects the spinal cord and brain and is characterized by severe neuroinflammation, demyelination, and subsequent neuronal damage, resulting in symptoms like loss of mobility. While untargeted and pan-immunosuppressive therapies have proven to be disease-modifying and manage (or prolong the time between) symptoms in many patients, a significant fraction are unable to achieve remission. Recent work has suggested that targeted neuroinflammation mitigation through selective inflammasome inhibition can offer relief to patients while preserving key components of immune function. Here, we show a screening of potential therapeutic targets using inflammasome-inhibiting Nanoligomers (NF-κB1, TNFR1, TNF-α, IL-6) that meet or far-exceed commercially available small-molecule counterparts like ruxolitinib, MCC950, and deucravacitinib. Using the human brain organoid model, top Nanoligomer combinations (NF-κB1 + TNFR1: NI111, and NF-κB1 + NLRP3: NI112) were shown to significantly reduce neuroinflammation without any observable negative impact on organoid function. Further testing of these top Nanoligomer combinations in an aggressive experimental autoimmune encephalomyelitis (EAE) mouse model for MS using intraperitoneal (IP) injections showed that NF-κB1 and NLRP3 targeting Nanoligomer combination NI112 rescues mice without observable loss of mobility or disability, minimal inflammation in brain and spinal cord histology, and minimal to no immune cell infiltration of the spinal cord and no demyelination, similar to or at par with mice that received no EAE injections (negative control). Mice receiving NI111 (NF-κB1 + TNFR1) also showed reduced neuroinflammation compared to saline (sham)-treated EAE mice and at par/similar to other inflammasome-inhibiting small molecule treatments, although it was significantly higher than NI112 leading to subsequent worsening clinical outcomes. Furthermore, treatment with an oral formulation of NI112 at lower doses showed a significant reduction in EAE severity, albeit with higher variance owing to administration and formulation/fill-and-finish variability. Overall, these results point to the potential of further development and testing of these inflammasome-targeting Nanoliogmers as an effective neuroinflammation treatment for multiple neurodegenerative diseases and potentially benefit several patients suffering from such debilitating autoimmune diseases like MS.

Thymol as a Potential Neuroprotective Agent: Mechanisms, Efficacy, and Future Prospects

Neurodegenerative diseases pose a growing global health challenge, with limited effective therapeutic options. Mitochondrial dysfunction, oxidative stress, neuroinflammation, apoptosis, and autophagy are common underlying mechanisms in these diseases. Thymol is a phenolic monoterpene compound that has gained attention for its diverse biological properties, including antioxidant, anti-inflammatory, and immunomodulatory activities. Thymol supplementation could provide potential neuroprotection and improve cognitive deficits, depressant-like effects, learning, and memory impairments in rodents. Mechanistic investigations reveal that the neuroprotective effects of thymol involve the improvement of oxidative stress, mitochondrial dysfunction, and inflammatory response. Several signaling pathways, including mitochondrial apoptotic, NF-κB, AKT, Nrf2, and CREB/BDNF pathways are also involved. In this review, the neuroprotective effects of thymol, the potential molecular mechanisms, safety, applications, and current challenges toward development as a neuroprotective agent were summarized and discussed. We hope that this review provides valuable insights for the further development of this promising natural product as a promising neuroprotective agent.

Therapeutic Potential of Natural Compounds in Subarachnoid Haemorrhage

Subarachnoid hemorrhage (SAH) is a common and fatal cerebrovascular disease with high morbidity, mortality and very poor prognosis worldwide. SAH can induce a complex series of pathophysiological processes, and the main factors affecting its prognosis are early brain injury (EBI) and delayed cerebral ischemia (DCI). The pathophysiological features of EBI mainly include intense neuroinflammation, oxidative stress, neuronal cell death, mitochondrial dysfunction and brain edema, while DCI is characterized by delayed onset ischemic neurological deficits and cerebral vasospasm (CVS). Despite much exploration in people to improve the prognostic outcome of SAH, effective treatment strategies are still lacking. In recent years, numerous studies have shown that natural compounds of plant origin have unique neuro- and vascular protective effects in EBI and DCI after SAH and long-term neurological deficits, which mainly include inhibition of inflammatory response, reduction of oxidative stress, anti-apoptosis, and improvement of blood-brain barrier and cerebral vasospasm. The aim of this paper is to systematically explore the processes of neuroinflammation, oxidative stress, and apoptosis in SAH, and to summarize natural compounds as potential targets for improving the prognosis of SAH and their related mechanisms of action for future therapies.

Patient-Derived Blood-Brain Barrier Model for Screening Copper Bis(thiosemicarbazone) Complexes as Potential Therapeutics in Alzheimer's Disease

Alzheimer's disease (AD) is the most prevalent cause of dementia characterized by a progressive cognitive decline. Addressing neuroinflammation represents a promising therapeutic avenue to treat AD; however, the development of effective antineuroinflammatory compounds is often hindered by their limited blood-brain barrier (BBB) permeability. Consequently, there is an urgent need for accurate, preclinical AD patient-specific BBB models to facilitate the early identification of immunomodulatory drugs capable of efficiently crossing the human AD BBB. This study presents a unique approach to BBB drug permeability screening as it utilizes the familial AD patient-derived induced brain endothelial-like cell (iBEC)-based model, which exhibits increased disease relevance and serves as an improved BBB drug permeability assessment tool when compared to traditionally employed in vitro models. To demonstrate its utility as a small molecule drug candidate screening platform, we investigated the effects of diacetylbis(N(4)-methylthiosemicarbazonato)copper(II) (CuII(atsm)) and a library of metal bis(thiosemicarbazone) complexes─a class of compounds exhibiting antineuroinflammatory therapeutic potential in neurodegenerative disorders. By evaluating the toxicity, cellular accumulation, and permeability of those compounds in the AD patient-derived iBEC, we have identified 3,4-hexanedione bis(N(4)-methylthiosemicarbazonato)copper(II) (CuII(dtsm)) as a candidate with good transport across the AD BBB. Furthermore, we have developed a multiplex approach where AD patient-derived iBEC were combined with immune modulators TNFα and IFNγ to establish an in vitro model representing the characteristic neuroinflammatory phenotype at the patient's BBB. Here, we observed that treatment with CuII(dtsm) not only reduced the expression of proinflammatory cytokine genes but also reversed the detrimental effects of TNFα and IFNγ on the integrity and function of the AD iBEC monolayer. This suggests a novel pathway through which copper bis(thiosemicarbazone) complexes may exert neurotherapeutic effects on AD by mitigating BBB neuroinflammation and related BBB integrity impairment. Together, the presented model provides an effective and easily scalable in vitro BBB platform for screening AD drug candidates. Its improved translational potential makes it a valuable tool for advancing the development of metal-based compounds aimed at modulating neuroinflammation in AD.

Targeting Neuroinflammation by Pharmacologic Downregulation of Inflammatory Pathways Is Neuroprotective in Protein Misfolding Disorders

Neuroinflammation plays a crucial role in the development of neurodegenerative protein misfolding disorders. This category of progressive diseases includes, but is not limited to, Alzheimer's disease, Parkinson's disease, and prion diseases. Shared pathogenesis involves the accumulation of misfolded proteins, chronic neuroinflammation, and synaptic dysfunction, ultimately leading to irreversible neuronal loss, measurable cognitive deficits, and death. Presently, there are few to no effective treatments to halt the advancement of neurodegenerative diseases. We hypothesized that directly targeting neuroinflammation by downregulating the transcription factor, NF-κB, and the inflammasome protein, NLRP3, would be neuroprotective. To achieve this, we used a cocktail of RNA targeting therapeutics (SB_NI_112) shown to be brain-penetrant, nontoxic, and effective inhibitors of both NF-κB and NLRP3. We utilized a mouse-adapted prion strain as a model for neurodegenerative diseases to assess the aggregation of misfolded proteins, glial inflammation, neuronal loss, cognitive deficits, and lifespan. Prion-diseased mice were treated either intraperitoneally or intranasally with SB_NI_112. Behavioral and cognitive deficits were significantly protected by this combination of NF-κB and NLRP3 downregulators. Treatment reduced glial inflammation, protected against neuronal loss, prevented spongiotic change, rescued cognitive deficits, and significantly lengthened the lifespan of prion-diseased mice. We have identified a nontoxic, systemic pharmacologic that downregulates NF-κB and NLRP3, prevents neuronal death, and slows the progression of neurodegenerative diseases. Though mouse models do not always predict human patient success and the study was limited due to sample size and number of dosing methods utilized, these findings serve as a proof of principle for continued translation of the therapeutic SB_NI_112 for prion disease and other neurodegenerative diseases. Based on the success in a murine prion model, we will continue testing SB_NI_112 in a variety of neurodegenerative disease models, including Alzheimer's disease and Parkinson's disease.

Neuroinflammation drives sex-dependent effects on pain and negative affect in a murine model of repeated mild traumatic brain injury

ABSTRACT

The Center for Disease Control and Prevention estimates that 75% of reported cases of traumatic brain injury (TBI) are mild, where chronic pain and depression are 2 of the most common symptoms. In this study, we used a murine model of repeated mild TBI to characterize the associated pain hypersensitivity and affective-like behavior and to what extent microglial reactivity contributes to these behavioral phenotypes. Male and female C57BL/6J mice underwent sham or repeated mild traumatic brain injury (rmTBI) and were tested for up to 9 weeks postinjury, where an anti-inflammatory/neuroprotective drug (minocycline) was introduced at 5 weeks postinjury in the drinking water. Repeated mild traumatic brain injury mice developed cold nociceptive hypersensitivity and negative affective states, as well as increased locomotor activity and risk-taking behavior. Minocycline reversed negative affect and pain hypersensitivities in male but not female mice. Repeated mild traumatic brain injury also produced an increase in microglial and brain-derived neurotropic factor mRNA transcripts in limbic structures known to be involved in nociception and affect, but many of these changes were sex dependent. Finally, we show that the antiepileptic drug, gabapentin, produced negative reinforcement in male rmTBI mice that was prevented by minocycline treatment, whereas rmTBI female mice showed a place aversion to gabapentin. Collectively, pain hypersensitivity, increased tonic-aversive pain components, and negative affective states were evident in both male and female rmTBI mice, but suppression of microglial reactivity was only sufficient to reverse behavioral changes in male mice. Neuroinflammation in limbic structures seems to be a contributing factor in behavioral changes resulting from rmTBI.

Immunotherapeutic Properties of Dexmedetomidine on Pain Management and Cardiovascular Function in Videolaparoscopic Cholecystectomies: A Randomized, Two-Arm, Double-Blinded, Placebo-Controlled Trial

BACKGROUND

Laparoscopy represented one of the most innovative surgical techniques approached in the surgery field. Dexmedetomidine association with general anesthesia promotes the response control to trauma by altering the neuroinflammatory reflex, provides better clinical outcomes in the postoperative period and reduces the excessive use of drugs with risk for addiction. This trial aims to evaluate the potential drug treatment of dexmedetomidine on organic function, with the targets in neuroinflammation, perioperative pain control and blood pressure measurements in a medium-sized surgical model.

METHODS

Fifty-two patients were randomized in two groups: Sevoflurane and Dexmedetomidine - A (dexmedetomidine infusion [1 μg/kg loading, .2-.5 μg/kg/h thereafter]) vs Sevoflurane and Saline .9% - B. Three blood samples were collected at three times: before surgery, 4 to 6 hours after surgery and 24 hours postoperatively. The primary outcome was inflammatory and endocrine mediators dosage analisys. Finally, we evaluated pain and opioid use as secondary outcomes, also the hemodynamic values.

RESULTS

In Dexmedetomidine group A, a reduction of Interleukin 6 was found during 4-6 hours after surgery. A reduction of IL-10 was noted in the measurement of its values 24 hours after the procedure, with statistical significance. Also, systolic and diastolic blood pressure, as well heart rate were attenuated, and there was a lower incidence of pain and opioid consumption in the first postoperative hour (P < .0001) in the anesthetic recovery room.

CONCLUSIONS

Dexmedetomidine provided anti-inflammatory activity, sympatholytic effect and analgesia with cardiovascular safety. It reinforces the therapeutic nature of highly selective α2-adrenergic agonists when combined within anesthetic interventions.

Second Near-Infrared Macrophage-Biomimetic Nanoprobes for Photoacoustic Imaging of Neuroinflammation

Neuroinflammation is a significant pathological event involving the neurodegenerative process associated with many neurological disorders. Diagnosis and treatment of neuroinflammation in its early stage are essential for the prevention and management of neurological diseases. Herein, we designed macrophage membrane-coated photoacoustic (PA) probes (MSINPs), with targeting specificities based on naturally existing target-ligand interactions for the early diagnosis of neuroinflammation. The second near-infrared dye, IR1061, was doped into silica as the core and was encapsulated with a macrophage membrane. In vitro as well as in vivo, the MSINPs could target inflammatory cells via the inflammation chemotactic effect. PA imaging was used to trace the MSINPs in a neuroinflammation mouse model and showed a great targeted effect of MSINPs in the prefrontal cortex. Therefore, the biomimetic nanoprobe prepared in this study offers a new strategy for PA molecular imaging of neuroinflammation, which can enhance our understanding of the evolution of neuroinflammation in specific brain regions.

Versatile strategies for adult neurogenesis: avenues to repair the injured brain

Brain injuries due to trauma or stroke are major causes of adult death and disability. Unfortunately, few interventions are effective for post-injury repair of brain tissue. After a long debate on whether endogenous neurogenesis actually happens in the adult human brain, there is now substantial evidence to support its occurrence. Although neurogenesis is usually significantly stimulated by injury, the reparative potential of endogenous differentiation from neural stem/progenitor cells is usually insufficient. Alternatively, exogenous stem cell transplantation has shown promising results in animal models, but limitations such as poor long-term survival and inefficient neuronal differentiation make it still challenging for clinical use. Recently, a high focus was placed on glia-to-neuron conversion under single-factor regulation. Despite some inspiring results, the validity of this strategy is still controversial. In this review, we summarize historical findings and recent advances on neurogenesis strategies for neurorepair after brain injury. We also discuss their advantages and drawbacks, as to provide a comprehensive account of their potentials for further studies.

Epigenetics and the neurodegenerative process

Neurological diseases are multifactorial, genetic and environmental. Environmental factors such as diet, physical activity and emotional state are epigenetic factors. Environmental markers are responsible for epigenetic modifications. The effect of epigenetic changes is increased inflammation of the nervous system and neuronal damage. In recent years, it has been shown that epigenetic changes may cause an increased risk of neurological disorders but, currently, the relationship between epigenetic modifications and neurodegeneration remains unclear. This review summarizes current knowledge about neurological disorders caused by epigenetic changes in diseases such as Alzheimer's disease, Parkinson's disease, stroke and epilepsy. Advances in epigenetic techniques may be key to understanding the epigenetics of central changes in neurological diseases.

Short-Term Effects of Gamma Stimulation on Neuroinflammation at the Tissue-Electrode Interface in Motor Cortex

OBJECTIVES

The reliability of long-term neural recordings as therapeutic interventions for motor and sensory disorders is hampered by the brain tissue response. Previous work showed that flickering light at gamma frequencies (ie, 20-50 Hz) causes enhanced microglial recruitment in the visual cortex. The effects of gamma stimulation on glial cells surrounding implanted neural electrodes are not well understood. We hypothesized that invasive stimulation in the gamma frequency band increases microglial recruitment in the short term and reduces astrogliosis at the tissue-electrode interface.

MATERIALS AND METHODS

Male Long Evans rats were implanted with dual-shank silicon microelectrode arrays into the motor cortex. After implantation, rats received one hour of 40-Hz stimulation at a constant current of 10 μA using charge-balanced, biphasic pulses on one shank, and the other shank served as the nonstimulated control. Postmortem, tissue sections were stained with ectodermal dysplasia 1 (ED1) for activated microglia, glial fibrillary acidic protein (GFAP) for astrocytes, and 4',6-diamidino-2-phenylindole (DAPI) for nonspecific nuclei. Fluorescent intensity and cell number as a function of distance from the tissue-electrode interface were used to quantify all stained sections.

RESULTS

Fluorescent intensity for ED1 was nearly 40% lower for control than for stimulated sites (0-500 μm away from the implant), indicating increased microglial recruitment to the stimulated site (p < 0.05). Fluorescent intensity for GFAP was >67% higher for control than for stimulated sites (0-500 μm away from the implant), indicating reduced astrogliosis at the stimulated site (p < 0.05). No differences were observed in DAPI-stained sections between conditions.

CONCLUSIONS

These results suggest that short-term gamma stimulation modulates glial recruitment in the immediate vicinity of the microelectrode. Future studies will investigate the long-term effects of gamma stimulation on glial recruitment at the tissue-electrode interface as a strategy to improve long-term recording reliability.

Therapeutic Polymer-Based Cannabidiol Formulation: Tackling Neuroinflammation Associated with Ischemic Events in the Brain

Cannabidiol (CBD) is the most relevant nonpsychostimulant phytocompound found in Cannabis sativa. CBD has been extensively studied and has been proposed as a therapeutic candidate for neuroinflammation-related conditions. However, being a highly lipophilic drug, it has several drawbacks for pharmaceutical use, including low solubility and high permeability. Synthetic polymers can be used as drug delivery systems to improve CBD's stability, half-life, and biodistribution. Here, we propose using a synthetic polymer as a nanoparticulate vehicle for CBD (NPCBD) to overcome the pharmacological drawbacks of free drugs. We tested the NPCBD-engineered system in the context of ischemic events in a relevant oxygen and glucose deprivation (OGD) model in primary cortical cells (PCC). Moreover, we have characterized the inflammatory response of relevant cell types, such as THP-1 (human monocytes), HMC3 (human microglia), and PCC, to NPCBD and observed a shift in the inflammatory state of the treated cells after the ischemic event. In addition, NPCBD exhibited a promising ability to restore mitochondrial function after OGD insult in both HMC3 and PCC cells at low doses of 1 and 0.2 μM CBD. Taken together, these results suggest the potential for preclinical use.

Valproic acid ameliorates cauda equina injury by suppressing HDAC2-mediated ferroptosis

INTRODUCTION

Persistent neuroinflammatory response after cauda equina injury (CEI) lowers nociceptor firing thresholds, accompanied by pathological pain and decreasing extremity dysfunction. Histone deacetylation has been considered a key regulator of immunity, inflammation, and neurological dysfunction. Our previous study suggested that valproic acid (VPA), a histone deacetylase inhibitor, exhibited neuroprotective effects in rat models of CEI, although the underlying mechanism remains elusive.

METHODS

The cauda equina compression surgery was performed to establish the CEI model. The Basso, Beattie, Bresnahan score, and the von Frey filament test were carried out to measure the animal behavior. Immunofluorescence staining of myelin basic protein and GPX4 was carried out. In addition, transmission electron microscope analysis was used to assess the effect of VPA on the morphological changes of mitochondria. RNA-sequencing was conducted to clarify the underlying mechanism of VPA on CEI protection.

RESULTS

In this current study, we revealed that the expression level of HDAC1 and HDAC2 was elevated after cauda equina compression model but was reversed by VPA treatment. Meanwhile, HDAC2 knockdown resulted in the improvement of motor functions and pathologic pain, similar to treatment with VPA. Histology analysis also showed that knockdown of histone deacetylase (HDAC)-2, but not HDAC1, remarkably alleviated cauda equina injury and demyelinating lesions. The potential mechanism may be related to lowering oxidative stress and inflammatory response in the injured region. Notably, the transcriptome sequencing indicated that the therapeutic effect of VPA may depend on HDAC2-mediated ferroptosis. Ferroptosis-related genes were analyzed in vivo and DRG cells further validated the reliability of RNA-sequencing results, suggesting HDAC2-H4K12ac axis participated in epigenetic modulation of ferroptosis-related genes.

CONCLUSION

HDAC2 is critically involved in the ferroptosis and neuroinflammation in cauda equina injury, and VPA ameliorated cauda equina injury by suppressing HDAC2-mediated ferroptosis.

Cognition is selectively impaired in males with spinal pain: A retrospective analysis of data from the Longitudinal Study of Ageing Danish Twins

Cognitive decline and spinal pain (back pain [BP] and neck pain [NP]) represent a major public health challenge, yet the potential relationship between them remains elusive. A retrospective analysis of the Longitudinal Study of Ageing Danish Twins was performed to determine any potential relationships between BP/NP and cognitive function adjusting for age, sex, educational and socioeconomic status. A total of 4731 adults (2788 females/1943 males) aged 78 ± 6 (SD) years were included in the analysis. We observed a 1-month prevalence of 25% with BP, 21% with NP and 11% for combined BP/NP. While there were no differences in cognition scores for males and females reporting combined BP/NP, compared to those without combined BP/NP (34.38 points [95% confidence interval (CI) = 31.88, 36.88] vs. 35.72 points [95% CI = 35.19, 36.26]; P = 0.180; and 35.72 points [95% CI = 35.19, 36.26] vs. 35.85 points [95% CI = 35.39, 36.31]; P = 0.327; for male and females, respectively), an adjusted analysis revealed that males with combined BP/NP presented with lower cognitive scores compared to males without combined BP/NP (81.26 points [95% CI = 73.80, 88.72] vs. 79.48 points [95% CI = 70.31, 88.66]; P = 0.043). The findings of this hypothesis-generating study may highlight a potential sex-specific association between spinal pain and later-life neurodegeneration.

The SATB1-MIR22-GBA axis mediates glucocerebroside accumulation inducing a cellular senescence-like phenotype in dopaminergic neurons

Idiopathic Parkinson's disease (PD) is characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta, which is associated with neuroinflammation and reactive gliosis. The underlying cause of PD and the concurrent neuroinflammation are not well understood. In this study, we utilize human and murine neuronal lines, stem cell-derived dopaminergic neurons, and mice to demonstrate that three previously identified genetic risk factors for PD, namely SATB1, MIR22HG, and GBA, are components of a single gene regulatory pathway. Our findings indicate that dysregulation of this pathway leads to the upregulation of glucocerebrosides (GluCer), which triggers a cellular senescence-like phenotype in dopaminergic neurons. Specifically, we discovered that downregulation of the transcriptional repressor SATB1 results in the derepression of the microRNA miR-22-3p, leading to decreased GBA expression and subsequent accumulation of GluCer. Furthermore, our results demonstrate that an increase in GluCer alone is sufficient to impair lysosomal and mitochondrial function, thereby inducing cellular senescence. Dysregulation of the SATB1-MIR22-GBA pathway, observed in both PD patients and normal aging, leads to lysosomal and mitochondrial dysfunction due to the GluCer accumulation, ultimately resulting in a cellular senescence-like phenotype in dopaminergic neurons. Therefore, our study highlights a novel pathway involving three genetic risk factors for PD and provides a potential mechanism for the senescence-induced neuroinflammation and reactive gliosis observed in both PD and normal aging.

'Unpredictable chronic mild stress does not exacerbate memory impairment or altered neuronal and glial plasticity in the hippocampus of middle-aged vitamin D deficient mice'

Vitamin D deficiency is a worldwide health concern, especially in the elderly population. Much remains unknown about the relationship between vitamin D deficiency (VDD), stress-induced cognitive dysfunctions and depressive-like behaviour. In this study, 4-month-old male C57Bl/6J mice were fed with control or vitamin D free diet for 6 months, followed by unpredictable chronic stress (UCMS) for 8 weeks. VDD induced cognitive impairment and reduced grooming behaviour, but did not induce depressive-like behaviour. While UCMS in vitamin D sufficient mice induced expected depressive-like phenotype and impairments in the contextual fear memory, chronic stress did not manifest as an additional risk factor for memory impairments and depressive-like behaviour in VDD mice. In fact, UCMS restored self-care behaviour in VDD mice. At the histopathological level, VDD mice exhibited cell loss in the granule cell layer, reduced survival of newly generated cells, accompanied with an increased number of apoptotic cells and alterations in glial morphology in the hippocampus; however, these effects were not exacerbated by UCMS. Interestingly, UCMS reversed VDD induced loss of microglial cells. Moreover, tyrosine hydroxylase levels decreased in the striatum of VDD mice, but not in stressed VDD mice. These findings indicate that long-term VDD in adulthood impairs cognition but does not augment behavioural response to UCMS in middle-aged mice. While VDD caused cell loss and altered glial response in the DG of the hippocampus, these effects were not exacerbated by UCMS and could contribute to mechanisms regulating altered stress response.

Metal-Organic Framework Based Nanozyme System for NLRP3 Inflammasome-Mediated Neuroinflammatory Regulation in Parkinson's Disease

Neuroinflammation is associated with a series of pathological symptoms in Parkinson's disease (PD), including α-synuclein aggregation and dopaminergic neuronal death. The NOD-like receptor protein 3 (NLRP3) inflammasome plays a crucial role in neuroinflammation at the lesion site and is a promising target for PD treatment. In this study, a nanoscale metal-organic framework (Zr-FeP MOF) based nanozyme is fabricated using Fe-5,10,15,20-tetra (4-carboxyphenyl) porphyrin (Fe-TCPP) and Zr6 cluster as ligands. The Zr-FeP MOF is subsequently encapsulated with mannitol (Man)-liposome, resulting in the formation of Zr-FeP MOF@Man liposome (MOF@Man Liposome) nanozyme system. The in vitro studies show that this nanozyme system is effective in relieving the formation of NLRP3 inflammasome and mitochondrial dysfunction. In mouse models of PD, the nanozyme system demonstrates a significant blood-brain barrier-crossing capability attributed to the Man-mediated brain targeting. Additionally, transcriptomic and biochemical studies show that the nanozyme system effectively inhibits the formation and assembly of inflammasome components, mitigating the activation of glial cells and neuroinflammatory response, and ultimately regulating the pathological symptoms of PD effectively.

Amelioration of morphine withdrawal syndrome by systemic and intranasal administration of mesenchymal stem cell-derived secretome in preclinical models of morphine dependence

BACKGROUND

Morphine is an opiate commonly used in the treatment of moderate to severe pain. However, prolonged administration can lead to physical dependence and strong withdrawal symptoms upon cessation of morphine use. These symptoms can include anxiety, irritability, increased heart rate, and muscle cramps, which strongly promote morphine use relapse. The morphine-induced increases in neuroinflammation, brain oxidative stress, and alteration of glutamate levels in the hippocampus and nucleus accumbens have been associated with morphine dependence and a higher severity of withdrawal symptoms. Due to its rich content in potent anti-inflammatory and antioxidant factors, secretome derived from human mesenchymal stem cells (hMSCs) is proposed as a preclinical therapeutic tool for the treatment of this complex neurological condition associated with neuroinflammation and brain oxidative stress.

METHODS

Two animal models of morphine dependence were used to evaluate the therapeutic efficacy of hMSC-derived secretome in reducing morphine withdrawal signs. In the first model, rats were implanted subcutaneously with mini-pumps which released morphine at a concentration of 10 mg/kg/day for seven days. Three days after pump implantation, animals were treated with a simultaneous intravenous and intranasal administration of hMSC-derived secretome or vehicle, and withdrawal signs were precipitated on day seven by i.p. naloxone administration. In this model, brain alterations associated with withdrawal were also analyzed before withdrawal precipitation. In the second animal model, rats voluntarily consuming morphine for three weeks were intravenously and intranasally treated with hMSC-derived secretome or vehicle, and withdrawal signs were induced by morphine deprivation.

RESULTS

In both animal models secretome administration induced a significant reduction of withdrawal signs, as shown by a reduction in a combined withdrawal score. Secretome administration also promoted a reduction in morphine-induced neuroinflammation in the hippocampus and nucleus accumbens, while no changes were observed in extracellular glutamate levels in the nucleus accumbens.

CONCLUSION

Data presented from two animal models of morphine dependence suggest that administration of secretome derived from hMSCs reduces the development of opioid withdrawal signs, which correlates with a reduction in neuroinflammation in the hippocampus and nucleus accumbens.