The Jak/STAT pathway is involved in synaptic plasticity

Xiao-xu-ming decoction improved synaptic damage after acute cerebral ischemia and reperfusion via JAK2/STAT3 pathway in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke is an important cause of death and disability worldwide. Xiao-xu-ming Decoction (XXMD) is a classic prescription for the treatment of stroke patients, which has been widely used in China and has significant therapeutic effect, but the therapeutic target and mechanism are still unclear.

AIM OF THE STUDY

The current study aimed to investigate temporal alternation of synaptic damage and the protective effects of XXMD on synaptic damage following cerebral ischemia and reperfusion in vivo.

MATERIALS AND METHODS

Adult male Sprague-Dawley (SD) rats subjected to 90 min of middle cerebral artery occlusion (MCAO) and subsequent reperfusion at various time points. Neurobehavioral function was assessed using modified neurological severity scores (mNSS), while pro-inflammatory cytokine levels were measured using ELISA kits. Histological assessment involved silver staining and Luxol Fast Blue (LFB) staining, and the ultrastructural alterations in neurons and synapses were examined using a transmission electron microscope (TEM). Golgi-cox staining was used to evaluate the density of dendritic spines. Levels of synapse-related proteins were quantified via immunofluorescence staining and Western blotting. Additionally, JAK2/STAT3 pathway related protein levels were assessed using Western blotting. In the second part, the rats were randomly divided into sham operation group, 24 h of reperfusion group, and XXMD group. The ultrastructural alterations and dendrite spine density of synapses were observed by TEM and Golgi-Cox staining respectively, and the expression levels of SYN, PSD95, GAP43, p-JAK2 and p-STAT3 were evaluated by WB.

RESULTS

Findings included deteriorated neurobehavioral function, increased release of IL-6, IL-1β, and TNFα, and time-dependent neuronal and synaptic damages during the initial phase of ischemia and reperfusion. At the ultrastructural level, neurons and synapses exhibited structural failure in the peri-infarct cortex. In addition, golgi-cox staining showed dendritic density in ischemic cortex significantly reduced after cerebral ischemia and reperfusion. Moreover, significant reductions in SYN, PSD95, and GAP43 expression levels, along with increases in p-JAK2 and p-STAT3 expression levels, were observed after cerebral ischemia and reperfusion. Meantime, XXMD significantly reduced synaptic impairment and up-regulated SYN, GAP43, PSD95 expression and down-regulated phosphorylation expression of JAK2 and STAT3 following MCAO and 24 h of reperfusion.

CONCLUSION

Collectively, these results indicates XXMD may play a neuroprotective role in reducing synaptic damage via JAK2/STAT3 signaling pathway.

Ruxolitinib-dependent reduction of seizure load and duration is accompanied by spatial memory improvement in the rat pilocarpine model of temporal lobe epilepsy

Molecules with optimized pharmacokinetic properties selectively aimed at the inhibition of STAT3 phosphorylation in brain have recently emerged as potential disease modifying therapies for epilepsy. In the current study, pharmacological inhibition of JAK1/2 with the orally available, FDA-approved drug ruxolitinib, produced nearly complete inhibition of hippocampal STAT3 phosphorylation, and reduced the expression of its downstream target Cyclin D1, when administered to rats 30 ​min and 3 ​h after onset of pilocarpine-induced status epilepticus (SE). This effect was accompanied by significantly shorter seizure duration and lower overall seizure frequency throughout the 4 weeks of EEG recording, but did not completely prevent the development of epilepsy in ruxolitinib-treated male rats. Compared to DMSO-treated animals, administration of ruxolitinib also improved memory (Y maze) but did not impact motor function (open field) following SE. Taken together with our previous findings, the results of this study provide further evidence that inhibition of the JAK/STAT pathway may be a promising disease modifying strategy to reduce severity of acquired epilepsy after brain injury, but also point to the need to better understand and optimize inhibitors of this pathway.

Photobiomodulation reduces spinal cord edema by decreasing the expression of AQP4 in the astrocytes of male spinal cord injury rats via the JAK2/STAT3 signaling pathway

BACKGROUND

Spinal cord swelling commonly occurs following SCI. Previous studies suggest that PBM may reduce inflammation and scar formation after SCI. However, whether PBM can alleviate post-spinal cord injury edema and its underlying mechanisms have not yet been reported. This study aims to investigate the effects of PBM on spinal cord swelling in rats following SCI and explore the underlying mechanisms.

METHODS

A rat model of SCI was established, and the rats received continuous PBM therapy for two weeks. Tissue hydration, motor function, AQP4 expression, and pathological changes in the spinal cord were evaluated at different time points. In vitro, astrocytes were subjected to PBM and treated with either cucurbitacin I or TGN020 following OGD.

RESULTS

The results indicate that PBM reduces tissue swelling in rats with SCI, improves motor function recovery, and inhibits the upregulation of AQP4 and GFAP associated with SCI. In vitro, PBM reduces abnormal activation of the JAK2/STAT3 signaling pathway in astrocytes, leading to decreased AQP4 synthesis and astrocyte activation.

CONCLUSIONS

These findings suggest that PBM reduces spinal cord swelling in rats after injury. This effect is associated with the inhibition of JAK2/STAT3 signaling pathway activation in astrocytes and the reduction in AQP4 expression.

Analysis of Differential microRNA Expression in the Hippocampus of Scopolamine-Induced Amnesic Mouse Model

Amnesia is characterized by memory deficits linked to various neurodegenerative pathologies and can be induced by the administration of scopolamine, a cholinergic antagonist. Scopolamine-induced amnesia is a well-studied pharmacological animal model that simulates memory impairment caused by aging, brain illnesses, neuropathologies, and trauma. However, the molecular mechanism of amnesia, more importantly in terms of microRNA (miRNA) regulation, is not well understood. Therefore, this study aimed to analyze miRNA profiles in the hippocampus of both control mice and those treated with scopolamine (amnesic mice). Initially, a short cDNA library was prepared for each sample and then sequenced on the Illumina platform. Among the total differentially expressed miRNAs, 113 were significantly upregulated and 96 were downregulated in the scopolamine group in comparison to the control group. Ten upregulated and ten downregulated miRNAs were validated to confirm the reliability of the sequencing results using qRT-PCR (quantitative real-time PCR). Furthermore, we performed a target prediction analysis intersecting the results from TargetScan, miRDB (miRNA database), and Miranda to analyze the targets of the dysregulated miRNAs. We also conducted a pathway analysis to investigate the molecular, cellular, and biological functions of these targets. miRNA‒target interactions were found to play roles in various signaling pathways during amnesia. These results provide an initial insight for the contribution of miRNAs to scopolamine-induced amnesia, as well as their possible application as markers of disease pathology.

Effects of chronic stress on cognitive function - From neurobiology to intervention

Exposure to chronic stress contributes considerably to the development of cognitive impairments in psychiatric disorders such as depression, generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and addictive behavior. Unfortunately, unlike mood-related symptoms, cognitive impairments are not effectively treated by available therapies, a situation in part resulting from a still incomplete knowledge of the neurobiological substrates that underly cognitive domains and the difficulty in generating interventions that are both efficacious and safe. In this review, we will present an overview of the cognitive domains affected by stress with a specific focus on cognitive flexibility, behavioral inhibition, and working memory. We will then consider the effects of stress on neuronal correlates of cognitive function and the factors which may modulate the interaction of stress and cognition. Finally, we will discuss intervention strategies for treatment of stress-related disorders and gaps in knowledge with emerging new treatments under development. Understanding how cognitive impairment occurs during exposure to chronic stress is crucial to make progress towards the development of new and effective therapeutic approaches.

Decoding paradoxical links of cytokine markers in cognition: Cross talk between physiology, inflammaging, and Alzheimer's disease- related cognitive decline

Recent research has revolutionized our understanding of memory consolidation by emphasizing the critical role of astrocytes, microglia, and immune cells in through cytokine signaling. Cytokines, compact proteins, play pivotal roles in neuronal development, synaptic transmission, and normal aging. This review explores the cellular mechanisms contributing to cognitive decline in inflammaging and Alzheimer's disease, highlighting the paradoxical effects of most studied cytokines (IL-1, IL-6, TNF-α) in brain function, which act as a double-edged sword in brain physiology, acting both as facilitators of healthy cognitive function and as a potential contributor to cognitive decline.

Grilled nux vomica alleviates myasthenia gravis by inhibiting the JAK2/STAT3 signaling pathway: a study in a mice model

BACKGROUND

Grilled Nux Vomica (GNV) is a promising traditional Chinese medicine to treat myasthenia gravis (MG), but its effects and mechanisms need further exploration.

METHODS

Experimental autoimmune MG (EAMG) model was established by muscle-specific kinase (MuSK) induction on C57BL/6 J mice. Mice were treated with GNV and/or ruxolitinib (JAK2 inhibitor) or AG490 (STAT3 inhibitor) for 30 days via gavage after modeling and randomized into 7 groups: control, model, low-dose GNV, middle-dose GNV, high-dose GNV, GNV + ruxolitinib, GNV + AG490. Body weight, muscle strength, clinical score, MuSK level, neuromuscular junction integrity (agrin and acetylcholine receptor [AChR] levels), inflammatory factors (IL-2 and IL-6), and the activation of the JAK2/STAT3 pathway were measured and compared between groups.

RESULTS

GNV significantly improved body weight and muscle strength, as well as reduced clinical scores, MuSK levels, and inflammatory markers (IL-2 and IL-6) levels compared with untreated EAMG mice. GNV also protected the neuromuscular junction and increased agrin and AChR co-expression in a dose-dependent manner. In addition, GNV attenuated the levels of p-JAK2 and p-STAT3, which are aberrantly upregulated in EAMG mice. After co-treatment with ruxolitinib or AG490, the effect of GNV on body weight, muscle strength, clinical score, MuSK level, neuromuscular junction integrity, levels of inflammatory factors, and JAK2/STAT3 pathway was further amplified in EAMG mice.

CONCLUSIONS

GNV improves MG by inhibiting the JAK2/STAT3 pathway, which might be an effective therapeutic strategy for MG.

Vanillic Acid Protects PC12 Cells from Corticosterone-Induced Neurotoxicity via Regulating Immune and Metabolic Dysregulation Based on Computational Metabolomics

Vanillic acid is widely used in the food industry and exhibits an excellent neuroprotective effect. Nevertheless, the mechanisms underlying them are largely unexplored, especially the interactions between the neuroprotection effects of vanillic acid and inflammation-immunity-metabolism. A cell metabolomics-based mathematics algorithm was reported to interpret the potential mechanism of vanillic acid on corticosterone-induced PC12 cells by regulating immune and metabolic dysregulation. Our results showed that vanillic acid markedly inhibited the level of inflammatory factors in corticosterone-induced PC12 cells. Cell metabolomics results suggested that vanillic acid regulated the abnormality of corticosterone-induced PC12 cell metabolic profiles and markedly regulated 11 differential metabolites. Our designed scoring model base entropy weight algorithm showed that the core targets (IL2RB, IFNA13, etc.) and metabolites (lactate, ethanolamine, etc.) regulate the immunity-metabolism of vanillic acid. Furthermore, we demonstrated that vanillic acid inhibited IL2RB expression and modulated the related pathway, JAK1/STAT3 signaling. The JAK inhibitor ABT-494 was further applied to validate the effect of vanillic acid on the JAK/STAT pathway. Results indicate that vanillic acid regulates the abnormal interactions of inflammation-immunity-metabolism by repressing the IL2RB-JAK1-STAT3 pathway. Methodologically, this study contributes to the decoding of vanillic acid's antidepressive effect from the metabolism perspective combined with computer algorithms and mathematics models.

JAK and STAT5B mediate olfactory response of migratory locusts to their own volatiles

Janus kinase (JAK) and signal transducer and activator of transcription (STAT) signaling affect social aggregation, mood and psychiatric disorders, nociceptive and depressive behaviors. Olfactory dysfunction is one of the distinct symptoms of these behaviors, but function and mechanism of JAK and STAT in modulating olfaction remain largely unknown. Migratory locusts show olfactory preference for their own volatiles. We thus use this animal model to explore functions and mechanisms of JAK and STAT5B in mediating olfaction response to their own volatiles. Tissue distribution study shows that JAK and STAT5B express in antennae and brains, especially in antennal lobes and mushroom bodies in locust brains, and knockdown of these two genes by RNA interference (RNAi) in antennae and brains results in the loss of olfactory preference for locust volatiles, including chemical odorants indole and β-ionone. RNA-seq analysis reveals that JAK and STAT5B RNAi knockdown downregulates a functional class of transcripts in nucleoprotein complex, including heterogeneous nuclear ribonucleoprotein C (hnRNPC) and small nuclear ribonucleoprotein polypeptide F (SNRPF). HnRNPC and SNRPF mRNAs and proteins are also expressed in antennae and brains, and RNAi knockdown of these two genes reduces the percentage of locusts preferring volatiles, including chemical odorants indole and β-ionone. Furthermore, RNAi knockdown of dopamine receptor 1 (DopR1) results in the decrease of JAK mRNA level in antennae, and JAK/STAT5B, hnRNPC and SNRPF are required for dopamine receptor 1 (DopR1) to modulate olfactory preference for their own volatiles. This study confirms that JAK/STAT5B signaling modulates olfaction by affecting expression levels of hnRNPC and SNRPF, and this pathway is also required for DopR1 to modulate olfactory preference for their own volatiles. These findings highlight novel roles of JAK and STAT5B in modulating olfactory preference. This study provides novel insights into functional links among JAK/STAT5B signaling, RNA binding proteins and DopR1 underlying the modulation of olfactory behaviors.

Antenatal steroids elicited neurodegenerative-associated transcriptional changes in the hippocampus of preterm fetal sheep independent of lung maturation

BACKGROUND

Antenatal steroid therapy for fetal lung maturation is routinely administered to women at risk of preterm delivery. There is strong evidence to demonstrate benefit from antenatal steroids in terms of survival and respiratory disease, notably in infants delivered at or below 32 weeks' gestation. However, dosing remains unoptimized and lung benefits are highly variable. Current treatment regimens generate high-concentration, pulsatile fetal steroid exposures now associated with increased risk of childhood neurodevelopmental diseases. We hypothesized that damage-associated changes in the fetal hippocampal transcriptome would be independent of preterm lung function.

METHODS

Date-mated ewes carrying a single fetus at 122 ± 2dGA (term = 150dGA) were randomized into 4 groups: (i) Saline Control Group, 4×2ml maternal saline intramuscular(IM) injections at 12hr intervals (n = 11); or (ii) Dex High Group, 2×12mg maternal IM dexamethasone phosphate injections at 12hr intervals followed by 2×2ml IM saline injections at 12hr intervals (n = 12; representing a clinical regimen used in Singapore); or (iii) Dex Low Group, 4×1.5mg maternal IM dexamethasone phosphate injections 12hr intervals (n = 12); or (iv) Beta-Acetate Group, 1×0.125mg/kg maternal IM betamethasone acetate injection followed by 3×2ml IM sterile normal saline injections 12hr intervals (n = 8). Lambs were surgically delivered 48hr after first maternal injection at 122-125dGA, ventilated for 30min to establish lung function, and euthanised for necropsy and tissue collection.

RESULTS

Preterm lambs from the Dex Low and Beta-Acetate Groups had statistically and biologically significant lung function improvements (measured by gas exchange, lung compliance). Compared to the Saline Control Group, hippocampal transcriptomic data identified 879 differentially significant expressed genes (at least 1.5-fold change and FDR < 5%) in the steroid-treated groups. Pulsatile dexamethasone-only exposed groups (Dex High and Dex Low) had three common positively enriched differentially expressed pathways related in part to neurodegeneration ("Prion Disease", "Alzheimer's Disease", "Arachidonic Acid metabolism"). Adverse changes were independent of respiratory function during ventilation.

CONCLUSIONS

Our data suggests that exposure to antenatal steroid therapy is an independent cause of damage- associated transcriptomic changes in the brain of preterm, fetal sheep. These data highlight an urgent need for careful reconsideration and balancing of how antenatal steroids are used, both for patient selection and dosing regimens.

Testis-Specific Protein, Y-Encoded-Like 2 Activates JAK2/STAT3 Pathway in Hypothalamic Paraventricular Nucleus to Sustain Hypertension

BACKGROUND

In the hypothalamic paraventricular nucleus (PVN) of spontaneously hypertensive rats (SHRs), the expression of the testis-specific protein, Y-encoded-like 2 (TSPYL2) and the phosphorylation level of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) are higher comparing with the normotensive Wistar Kyoto rats (WKY). But how they are involved in hypertension remains unclear. TSPYL2 may interact with JAK2/STAT3 in PVN to sustain high blood pressure during hypertension.

METHODS

Knockdown of TSPYL2 via adeno-associated virus (AAV) carrying shRNA was conducted through bilateral microinjection into the PVN of SHR and WKY rats. JAK2/STAT3 inhibition was achieved by intraperitoneally or PVN injection of AG490 into the SHRs. Blood pressure (BP), plasma norepinephrine (NE), PVN inflammatory response, and PVN oxidative stress were measured.

RESULTS

TSPYL2 knock-down in the PVN of SHRs but not WKYs led to reduced BP and plasma NE, deactivation of JAK2/STAT3, decreased expression of pro-inflammatory cytokine IL-1β, and increased expression of anti-inflammatory cytokine IL-10 in the PVN. Meanwhile, AG490 administrated in both ways reduced the BP in the SHRs and deactivated JAK2/STAT3 but failed to change the expression of TSPYL2 in PVN. AG490 also downregulated expression of IL-1β and upregulated expression of IL-10. Both knockdown of TSPYL2 and inhibition of JAK2/STAT3 can reduce the oxidative stress in the PVN of SHRs.

CONCLUSION

JAK2/STAT3 is regulated by TSPYL2 in the PVN of SHRs, and PVN TSPYL2/JAK2/STAT3 is essential for maintaining high BP in hypertensive rats, making it a potential therapeutic target for hypertension.

Bioinformatic Evaluation of KLF13 Genetic Variant: Implications for Neurodevelopmental and Psychiatric Symptoms

The Krüppel-like factor (KLF) family represents a group of transcription factors (TFs) performing different biological processes that are crucial for proper neuronal function, including neuronal development, synaptic plasticity, and neuronal survival. As reported, genetic variants within the KLF family have been associated with a wide spectrum of neurodevelopmental and psychiatric symptoms. In a patient exhibiting attention deficit hyperactivity disorder (ADHD) combined with both neurodevelopmental and psychiatric symptoms, whole-exome sequencing (WES) analysis revealed a de novo heterozygous variant within the Krüppel-like factor 13 (KLF13) gene, which belongs to the KLF family and regulates axonal growth, development, and regeneration in mice. Moreover, in silico analyses pertaining to the likely pathogenic significance of the variant and the impact of the mutation on the KLF13 protein structure suggested a potential deleterious effect. In fact, the variant was localized in correspondence to the starting residue of the N-terminal domain of KLF13, essential for protein-protein interactions, DNA binding, and transcriptional activation or repression. This study aims to highlight the potential involvement of the KLF13 gene in neurodevelopmental and psychiatric disorders. Nevertheless, we cannot rule out that excluded variants, those undetectable by WES, or the polygenic risk may have contributed to the patient's phenotype given ADHD's high polygenic risk. However, further functional studies are required to validate its potential contribution to these disorders.

Mapping dynamic molecular changes in hippocampal subregions after traumatic brain injury through spatial proteomics

BACKGROUND

Traumatic brain injury (TBI) often results in diverse molecular responses, challenging traditional proteomic studies that measure average changes at tissue levels and fail to capture the complexity and heterogeneity of the affected tissues. Spatial proteomics offers a solution by providing insights into sub-region-specific alterations within tissues. This study focuses on the hippocampal sub-regions, analyzing proteomic expression profiles in mice at the acute (1 day) and subacute (7 days) phases of post-TBI to understand subregion-specific vulnerabilities and long-term consequences.

METHODS

Three mice brains were collected from each group, including Sham, 1-day post-TBI and 7-day post-TBI. Hippocampal subregions were extracted using Laser Microdissection (LMD) and subsequently analyzed by label-free quantitative proteomics.

RESULTS

The spatial analysis reveals region-specific protein abundance changes, highlighting the elevation of FN1, LGALS3BP, HP, and MUG-1 in the stratum moleculare (SM), suggesting potential immune cell enrichment post-TBI. Notably, established markers of chronic traumatic encephalopathy, IGHM and B2M, exhibit specific upregulation in the dentate gyrus bottom (DG2) independent of direct mechanical injury. Metabolic pathway analysis identifies disturbances in glucose and lipid metabolism, coupled with activated cholesterol synthesis pathways enriched in SM at 7-Day post-TBI and subsequently in deeper DG1 and DG2 suggesting a role in neurogenesis and the onset of recovery. Coordinated activation of neuroglia and microtubule dynamics in DG2 suggest recovery mechanisms in less affected regions. Cluster analysis revealed spatial variations post-TBI, indicative of dysregulated neuronal plasticity and neurogenesis and further predisposition to neurological disorders. TBI-induced protein upregulation (MUG-1, PZP, GFAP, TJP, STAT-1, and CD44) across hippocampal sub-regions indicates shared molecular responses and links to neurological disorders. Spatial variations were demonstrated by proteins dysregulated in both or either of the time-points exclusively in each subregion (ELAVL2, CLIC1 in PL, CD44 and MUG-1 in SM, and SHOC2, LGALS3 in DG).

CONCLUSIONS

Utilizing advanced spatial proteomics techniques, the study unveils the dynamic molecular responses in distinct hippocampal subregions post-TBI. It uncovers region-specific vulnerabilities and dysregulated neuronal processes, and potential recovery-related pathways that contribute to our understanding of TBI's neurological consequences and provides valuable insights for biomarker discovery and therapeutic targets.

Function and Mechanism of Abscisic Acid on Microglia-Induced Neuroinflammation in Parkinson's Disease

Parkinson's disease (PD), as a neurologically implemented disease with complex etiological factors, has a complex and variable pathogenesis. Accompanying further research, neuroinflammation has been found to be one of the possible factors in its pathogenesis. Microglia, as intrinsic immune cells in the brain, play an important role in maintaining microenvironmental homeostasis in the brain. However, over-activation of neurotoxic microglia in PD promotes neuroinflammation, which further increases dopaminergic (DA) neuronal damage and exacerbates the disease process. Therefore, targeting and regulating the functional state of microglia is expected to be a potential avenue for PD treatment. In addition, plant extracts have shown great potential in the treatment of neurodegenerative disorders due to their abundant resources, mild effects, and the presence of multiple active ingredients. However, it is worth noting that some natural products have certain toxic side effects, so it is necessary to pay attention to distinguish medicinal ingredients and usage and dosage when using to avoid aggravating the progression of diseases. In this review, the roles of microglia with different functional states in PD and the related pathways inducing microglia to transform into neuroprotective states are described. At the same time, it is discussed that abscisic acid (ABA) may regulate the polarization of microglia by targeting them, promote their transformation into neuroprotective state, reduce the neuroinflammatory response in PD, and provide a new idea for the treatment of PD and the selection of drugs.

Unraveling the role of glial cell line-derived neurotrophic factor in the treatment of Parkinson's disease

Parkinson's disease is the second most common neurodegenerative condition with its prevalence projected to 8.9 million individuals globally in the year 2019. Parkinson's disease affects both motor and certain non-motor functions of an individual. Numerous research has focused on the neuroprotective effect of the glial cell line-derived neurotrophic factor (GDNF) in Parkinson's disease. Discovered in 1993, GDNF is a neurotrophic factor identified from the glial cells which was found to have selective effects on promoting survival and regeneration of certain populations of neurons including the dopaminergic nigrostriatal pathway. Given this property, recent studies have focused on the exogenous administration of GDNF for relieving Parkinson's disease-related symptoms both at a pre-clinical and a clinical level. This review will focus on enumerating the molecular connection between Parkinson's disease and GDNF and shed light on all the available drug delivery approaches to facilitate the selective delivery of GDNF into the brain paving the way as a potential therapeutic candidate for Parkinson's disease in the future.

STAT3 ameliorates truncated tau-induced cognitive deficits

Proteolytic cleavage of tau by asparagine endopeptidase (AEP) creates tau-N368 fragments, which may drive the pathophysiology associated with synaptic dysfunction and memory deterioration in the brain of Alzheimer's disease patients. Nonetheless, the molecular mechanisms of truncated tau-induced cognitive deficits remain unclear. Evidence suggests that signal transduction and activator of transcription-3 (STAT3) is associated with modulating synaptic plasticity, cell apoptosis, and cognitive function. Using luciferase reporter assays, electrophoretic mobility shift assays, western blotting, and immunofluorescence, we found that human tau-N368 accumulation inhibited STAT3 activity by suppressing STAT3 translocation into the nucleus. Overexpression of STAT3 improved tau-N368-induced synaptic deficits and reduced neuronal loss, thereby improving the cognitive deficits in tau-N368 mice. Moreover, in tau-N368 mice, activation of STAT3 increased N-methyl-D-aspartic acid receptor levels, decreased Bcl-2 levels, reversed synaptic damage and neuronal loss, and thereby alleviated cognitive deficits caused by tau-N368. Taken together, STAT3 plays a critical role in truncated tau-related neuropathological changes. This indicates a new mechanism behind the effect of tau-N368 on synapses and memory deficits. STAT3 can be used as a new molecular target to treat tau-N368-induced protein pathology.

Drug repurposing and personalized treatment strategies for bipolar disorder using transcriptomics: an exploratory study

OBJECTIVE

The present study combined transcriptomic data and computational techniques based on gene expression signatures to identify new bioactive compounds or Food and Drug Administration-approved drugs for the treatment of bipolar disorder (BD).

METHODS

Five transcriptomic datasets containing 165 blood samples from individuals with BD were selected from the Gene Expression Omnibus (GEO). The number of participants varied from six to 60, with a mean age between 35 and 48 years and a gender difference between them. Most of these patients were receiving pharmacological treatment. Master regulator analysis (MRA) and gene set enrichment analysis (GSEA) were performed to identify genes that were significantly different between patients with BD and healthy controls and their associations with mood states in patients with BD. In addition, molecules that could reverse the transcriptomic profiles of BD-altered regulons were identified from the Library of Network-Based Cellular Signatures Consortium (LINCS) and the Broad Institute Connectivity Map Drug Repurposing Database (cMap) databases.

RESULTS

MRA identified 59 candidate master regulators (MRs) that modulate regulatory units enriched with BD-altered genes. In contrast, GSEA identified 134 enriched genes and 982 regulons whose activation state was determined. Both analyses revealed genes exclusively associated with mania, depression, or euthymia, and some genes were shared among these three mood states. We identified bioactive compounds and licensed drug candidates, including antihypertensives and antineoplastic agents, as promising candidates for the treatment of BD. However, experimental validation is essential to confirm these findings in further studies.

CONCLUSION

Although our data are still preliminary, they provide some insights into the biological patterns of different mood states in patients with BD and their potential therapeutic targets. The strategy of transcriptomics plus bioinformatics offers a way to advance drug discovery and personalized medicine by using gene expression information.

Therapeutic potential of stilbenes in neuropsychiatric and neurological disorders: A comprehensive review of preclinical and clinical evidence

Neuropsychiatric disorders are anticipated to be a leading health concern in the near future, emphasizing an outstanding need for the development of new effective therapeutics to treat them. Stilbenes, with resveratrol attracting the most attention, are an example of multi-target compounds with promising therapeutic potential for a broad array of neuropsychiatric and neurological conditions. This review is a comprehensive summary of the current state of research on stilbenes in several neuropsychiatric and neurological disorders such as depression, anxiety, schizophrenia, autism spectrum disorders, epilepsy, traumatic brain injury, and neurodegenerative disorders. We describe and discuss the results of both in vitro and in vivo studies. The majority of studies concentrate on resveratrol, with limited findings exploring other stilbenes such as pterostilbene, piceatannol, polydatin, tetrahydroxystilbene glucoside, or synthetic resveratrol derivatives. Overall, although extensive preclinical studies show the potential benefits of stilbenes in various central nervous system disorders, clinical evidence on their therapeutic efficacy is largely missing.

Targeting the JAK2/STAT3 signaling pathway for chronic pain

Chronic pain is a notable health concern because of its prevalence, persistence, and associated mental stress. Drugs targeting chronic pain with potent abirritation, and minimal side effects remain unidentified. Substantial evidence indicates that the Janus Kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway plays a distinct and critical role in different stages of chronic pain. Aberrant activation of the JAK2/STAT3 signaling pathway is evident in multiple chronic pain models. Moreover, an increasing number of studies have demonstrated that the downregulation of JAK2/STAT3 can attenuate chronic pain in different animal models. In this review, we investigated the mechanism and role of the JAK2/STAT3 signaling pathway in modulating chronic pain. The aberrant activation of JAK2/STAT3 can trigger chronic pain by interacting with microglia and astrocytes, releasing proinflammatory cytokines, inhibiting anti-inflammatory cytokines, and regulating synaptic plasticity. We also retrospectively reviewed current reports on JAK2/STAT3 pharmacological inhibitors that demonstrated their significant therapeutic potential in different types of chronic pain. In summary, our results provide strong evidence that the JAK2/STAT3 signaling pathway is a promising therapeutic target for chronic pain.

Interplay of G-proteins and Serotonin in the Neuroimmunoinflammatory Model of Chronic Stress and Depression: A Narrative Review

INTRODUCTION

This narrative review addresses the clinical challenges in stress-related disorders such as depression, focusing on the interplay between neuron-specific and pro-inflammatory mechanisms at the cellular, cerebral, and systemic levels.

OBJECTIVE

We aim to elucidate the molecular mechanisms linking chronic psychological stress with low-grade neuroinflammation in key brain regions, particularly focusing on the roles of G proteins and serotonin (5-HT) receptors.

METHODS

This comprehensive review of the literature employs systematic, narrative, and scoping review methodologies, combined with systemic approaches to general pathology. It synthesizes current research on shared signaling pathways involved in stress responses and neuroinflammation, including calcium-dependent mechanisms, mitogen-activated protein kinases, and key transcription factors like NF-κB and p53. The review also focuses on the role of G protein-coupled neurotransmitter receptors (GPCRs) in immune and pro-inflammatory responses, with a detailed analysis of how 13 of 14 types of human 5-HT receptors contribute to depression and neuroinflammation.

RESULTS

The review reveals a complex interaction between neurotransmitter signals and immunoinflammatory responses in stress-related pathologies. It highlights the role of GPCRs and canonical inflammatory mediators in influencing both pathological and physiological processes in nervous tissue.

CONCLUSION

The proposed Neuroimmunoinflammatory Stress Model (NIIS Model) suggests that proinflammatory signaling pathways, mediated by metabotropic and ionotropic neurotransmitter receptors, are crucial for maintaining neuronal homeostasis. Chronic mental stress can disrupt this balance, leading to increased pro-inflammatory states in the brain and contributing to neuropsychiatric and psychosomatic disorders, including depression. This model integrates traditional theories on depression pathogenesis, offering a comprehensive understanding of the multifaceted nature of the condition.

TNFR1 signaling converging on FGF14 controls neuronal hyperactivity and sickness behavior in experimental cerebral malaria

BACKGROUND

Excess tumor necrosis factor (TNF) is implicated in the pathogenesis of hyperinflammatory experimental cerebral malaria (eCM), including gliosis, increased levels of fibrin(ogen) in the brain, behavioral changes, and mortality. However, the role of TNF in eCM within the brain parenchyma, particularly directly on neurons, remains underdefined. Here, we investigate electrophysiological consequences of eCM on neuronal excitability and cell signaling mechanisms that contribute to observed phenotypes.

METHODS

The split-luciferase complementation assay (LCA) was used to investigate cell signaling mechanisms downstream of tumor necrosis factor receptor 1 (TNFR1) that could contribute to changes in neuronal excitability in eCM. Whole-cell patch-clamp electrophysiology was performed in brain slices from eCM mice to elucidate consequences of infection on CA1 pyramidal neuron excitability and cell signaling mechanisms that contribute to observed phenotypes. Involvement of identified signaling molecules in mediating behavioral changes and sickness behavior observed in eCM were investigated in vivo using genetic silencing.

RESULTS

Exploring signaling mechanisms that underlie TNF-induced effects on neuronal excitability, we found that the complex assembly of fibroblast growth factor 14 (FGF14) and the voltage-gated Na+ (Nav) channel 1.6 (Nav1.6) is increased upon tumor necrosis factor receptor 1 (TNFR1) stimulation via Janus Kinase 2 (JAK2). On account of the dependency of hyperinflammatory experimental cerebral malaria (eCM) on TNF, we performed patch-clamp studies in slices from eCM mice and showed that Plasmodium chabaudi infection augments Nav1.6 channel conductance of CA1 pyramidal neurons through the TNFR1-JAK2-FGF14-Nav1.6 signaling network, which leads to hyperexcitability. Hyperexcitability of CA1 pyramidal neurons caused by infection was mitigated via an anti-TNF antibody and genetic silencing of FGF14 in CA1. Furthermore, knockdown of FGF14 in CA1 reduced sickness behavior caused by infection.

CONCLUSIONS

FGF14 may represent a therapeutic target for mitigating consequences of TNF-mediated neuroinflammation.

JAK-STAT signaling in inflammation and stress-related diseases: implications for therapeutic interventions

The Janus kinase-signal transducer and transcription activator pathway (JAK-STAT) serves as a cornerstone in cellular signaling, regulating physiological and pathological processes such as inflammation and stress. Dysregulation in this pathway can lead to severe immunodeficiencies and malignancies, and its role extends to neurotransduction and pro-inflammatory signaling mechanisms. Although JAK inhibitors (Jakinibs) have successfully treated immunological and inflammatory disorders, their application has generally been limited to diseases with similar pathogenic features. Despite the modest expression of JAK-STAT in the CNS, it is crucial for functions in the cortex, hippocampus, and cerebellum, making it relevant in conditions like Parkinson's disease and other neuroinflammatory disorders. Furthermore, the influence of the pathway on serotonin receptors and phospholipase C has implications for stress and mood disorders. This review expands the understanding of JAK-STAT, moving beyond traditional immunological contexts to explore its role in stress-related disorders and CNS function. Recent findings, such as the effectiveness of Jakinibs in chronic conditions such as rheumatoid arthritis, expand their therapeutic applicability. Advances in isoform-specific inhibitors, including filgotinib and upadacitinib, promise greater specificity with fewer off-target effects. Combination therapies, involving Jakinibs and monoclonal antibodies, aiming to enhance therapeutic specificity and efficacy also give great hope. Overall, this review bridges the gap between basic science and clinical application, elucidating the complex influence of the JAK-STAT pathway on human health and guiding future interventions.

The pharmacological mechanism of chaihu-jia-longgu-muli-tang for treating depression: integrated meta-analysis and network pharmacology analysis

Aim: Chaihu-jia-Longgu-Muli-tang (CLM) is derived from "Shang Han Lun" and is traditionally prescribed for treating depression. However, there is still a lack of evidence for its antidepressant effects, and the underlying mechanism is also unclear. This study aimed to assess clinical evidence on the efficacy of CLM in patients with depression using a meta-analysis and to explore its underlying antidepressant molecular mechanisms via network pharmacology. Methods: Eight open databases were searched for randomized controlled trials (RCTs) comparing the effects of CLM alone or combined with serotonin-norepinephrine reuptake inhibitors (SNRIs) and selective serotonin reuptake inhibitors (SSRIs) in patients with depression, evaluating the total effective rate of the treatment group (CLM alone or combined with SSRIs/SNRIs) and the control group (SNRIs or SSRIs), and comparing changes in depression scale, anxiety scale, sleep scale, inflammation indicators and adverse effects. Subsequently, the active ingredients and target genes of CLM were screened through six databases. Then Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and protein-protein interaction (PPI) network and topology analysis were performed. Finally, Molecular docking was applied to evaluate the binding affinity between components and predicted targets. Results: Twenty-four RCTs with a total of 2,382 patients were included. For the efficacy of antidepression and adverse effects, whether CLM alone or in combination with SSRIs/SNRIs, the treatment group has no inferior to that of the control group. Additionally, the intervention of CLM + SSRI significantly improved the symptoms of anxiety and insomnia, and reduced serum IL-6 and TNF-α levels. For network pharmacology, a total of 129 compounds and 416 intersection targets in CLM were retrieved. The interaction pathway between CLM and depression is mainly enriched in PI3K-Akt, JAK-STAT, and NF-κB signaling pathway, PIK3R1, MAPK3, and AKT1 may be the potential targets of Stigmasterol, β-stiosterol, coumestrol. Conclusion: Compared to SSRIs/SNRIs alone, CLM is more effective and safe in treating depression. It not only significantly alleviates depressive mood, but improves symptoms such as anxiety and insomnia, with fewer side effects, especially in combination with SSRI. Its antidepressant mechanism may be correlated with the regulation of the PI3K/Akt signaling pathway and inhibiting inflammatory response.

Minocycline and antipsychotics inhibit inflammatory responses in BV-2 microglia activated by LPS via regulating the MAPKs/ JAK-STAT signaling pathway

BACKGROUND

Abnormal activation of microglia is involved in the pathogenesis of schizophrenia. Minocycline and antipsychotics have been reported to be effective in inhibiting the activation of microglia and thus alleviating the negative symptoms of patients with schizophrenia. However, the specific molecular mechanism by which minocycline and antipsychotics inhibit microglial activation is not clear. In this study, we aimed to explore the molecular mechanism of treatment effect of minocycline and antipsychotics on schizophrenia.

METHODS

Microglia cells were activated by lipopolysaccharide (LPS) and further treated with minocycline, haloperidol, and risperidone. Then cell morphology, specific marker, cytokines, and nitric oxide production process, and the proteins in related molecular signaling pathways in LPS-activated microglia were compared among groups.

RESULTS

The study found that minocycline, risperidone, and haloperidol significantly inhibited morphological changes and reduced the expression of OX-42 protein induced by LPS. Minocycline significantly decreased the production of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-1beta (IL-1β). Risperidone also showed significant decrease in the production of IL-6 and TNF-α, while haloperidol only showed significant decrease in the production of IL-6. Minocycline, risperidone, and haloperidol were found to significantly inhibit nitric oxide (NO) expression, but had no effect on inducible nitric oxide synthase (iNOS) expression. Both minocycline and risperidone were effective in decreasing the activity of c‑Jun N‑terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) in the mitogen-activated protein kinases (MAPKs) signal pathway. Additionally, minocycline and risperidone were found to increase the activity of phosphorylated-p38. In contrast, haloperidol only suppressed the activity of ERK. Minocycline also suppressed the activation of janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3), while risperidone and haloperidol only suppressed the activation of STAT3.

CONCLUSIONS

The results demonstrated that minocycline and risperidone exert stronger anti-inflammatory and neuroprotective effects stronger than haloperidol, through MAPKs and Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathways in BV2 cells stimulated with LPS, revealing the underlying mechanisms of minocycline and atypical antipsychotics in the treatment of negative schizophrenia symptoms.

Allelic burden of Janus kinase 2 in a 6-month course of therapy for myeloproliferative neoplasms

BACKGROUND

Janus kinase 2 (JAK2) V617F gene mutation is an important marker for the diagnosis of Philadelphia negative Myeloproliferative neoplasms (MPN) which is subdivided into Polycythemia Vera (PV), Primary Myelofibrosis (PMF), and Essential Thrombocythemia (ET). The aim here is to investigate the JAK2 allele burden of the patients diagnosed with the subgroups of MPN and to demonstrate the alterations of hematological parameters and spleen size between diagnosis and 6 months of treatment.

METHODS

A total of 107 patients with the diagnosis of MPN and negative Philadelphia chromosome, 51 males and 56 females with a mean age of 59,74 ± 16,41 years, were included in the study. Diagnosis of MPN was based on the World Health Organization (WHO) criteria. Subgroups of MPN distributed as 49,5% ET, 46,7% PV, and 3,8% PMF. Findings such as the age of the patients, JAK-2 allele burden, and laboratory findings of splenomegaly were examined at the time of diagnosis, 3rd month, and 6th month. JAK2 allele burden and spleen size were re-evaluated in 6th month.

RESULTS

Our study confirmed the findings of high Hb, HCT, and RBC but low platelet values in PV patients with high JAK2 allele burden with respect to other groups, a positive correlation between JAK2 allele burden and LDH.

CONCLUSIONS

A novel finding of our study is, that there is not any reducing effect of the phlebotomy on JAK2 allele burden in PV patients whether they receive phlebotomy or not. Evaluation of the spleen size alteration during 6 months within the subgroups demonstrated a decrease in PV and ET groups whereas no statistically significant difference was found in the PMF group.

Prolonged fluoride exposure induces spatial-memory deficit and hippocampal dysfunction by inhibiting small heat shock protein 22 in mice

Millions of residents in areas with high-fluoride drinking water supply ingest excessive levels of fluoride for long periods. This study investigated the mechanisms and impacts of lifelong exposure to naturally occurring moderate-high-fluoride drinking water on spatial-memory function by studying mice in controlled experiments. Spatial-memory deficits and disorders of hippocampal neuronal electrical activity were observed in mice exposed to 25-ppm or 50-ppm-fluoride drinking water for 56 weeks, but not in adult or old mice exposed to 50 ppm fluoride for 12 weeks. Ultrastructural analysis showed severely damaged hippocampal mitochondria, evidenced by reduced mitochondrial membrane potential and ATP content. Mitochondrial biogenesis was impaired in fluoride-exposed mice, manifesting as a significantly reduced mtDNA content, mtDNA-encoded subunits mtND6 and mtCO1, and respiratory complex activities. Fluoride reduced expression of Hsp22, a beneficial mediator of mitochondrial homeostasis, and decreased levels of signaling for the PGC-1α/TFAM pathway-which regulates mitochondrial biogenesis-and the NF-κβ/STAT3 pathway-which regulates mitochondrial respiratory chain enzyme activity. Hippocampus-specific Hsp22-overexpression improved fluoride-induced spatial-memory deficits by activating the PGC-1α/TFAM and STAT3 signaling pathways, while Hsp22-silencing aggravated the deficits by inhibiting both pathways. Downregulation of Hsp22 plays a vital role in fluoride-induced spatial-memory deficits by impacting mtDNA-encoding subsets and mitochondrial respiratory chain enzyme activity.

Neuroimmune interactions with binge alcohol drinking in the cerebellum of IL-6 transgenic mice

The neuroimmune system of the brain, which is comprised primarily of astrocytes and microglia, regulates a variety of homeostatic mechanisms that underlie normal brain function. Numerous conditions, including alcohol consumption, can disrupt this regulatory process by altering brain levels of neuroimmune factors. Alcohol and neuroimmune factors, such as proinflammatory cytokines IL-6 and TNF-alpha, act at similar targets in the brain, including excitatory and inhibitory synaptic transmission. Thus, alcohol-induced production of IL-6 and/or TNF-alpha could be important contributing factors to the effects of alcohol on the brain. Recent studies indicate that IL-6 plays a role in alcohol drinking and the effects of alcohol on the brain activity following the cessation of alcohol consumption (post-alcohol period), however information on these topics is limited. Here we used homozygous and heterozygous female and male transgenic mice with increased astrocyte expression of IL-6 to examined further the interactions between alcohol and IL-6 with respect to voluntary alcohol drinking, brain activity during the post-alcohol period, IL-6 signal transduction, and expression of synaptic proteins. Wildtype littermates (WT) served as controls. The transgenic mice model brain neuroimmune status with respect to IL-6 in subjects with a history of persistent alcohol use. Results showed a genotype dependent reduction in voluntary alcohol consumption in the Drinking in the Dark protocol and in frequency-dependent relationships between brain activity in EEG recordings during the post-alcohol period and alcohol consumption. IL-6, TNF-alpha, IL-6 signal transduction partners pSTAT3 and c/EBP beta, and synaptic proteins were shown to play a role in these genotypic effects.

Aß Pathology and Neuron-Glia Interactions: A Synaptocentric View

Alzheimer's disease (AD) causes the majority of dementia cases worldwide. Early pathological hallmarks include the accumulation of amyloid-ß (Aß) and activation of both astrocytes and microglia. Neurons form the building blocks of the central nervous system, and astrocytes and microglia provide essential input for its healthy functioning. Their function integrates at the level of the synapse, which is therefore sometimes referred to as the "quad-partite synapse". Increasing evidence puts AD forward as a disease of the synapse, where pre- and postsynaptic processes, as well as astrocyte and microglia functioning progressively deteriorate. Here, we aim to review the current knowledge on how Aß accumulation functionally affects the individual components of the quad-partite synapse. We highlight a selection of processes that are essential to the healthy functioning of the neuronal synapse, including presynaptic neurotransmitter release and postsynaptic receptor functioning. We further discuss how Aß affects the astrocyte's capacity to recycle neurotransmitters, release gliotransmitters, and maintain ion homeostasis. We additionally review literature on how Aß changes the immunoprotective function of microglia during AD progression and conclude by summarizing our main findings and highlighting the challenges in current studies, as well as the need for further research.

IgSF11-mediated phosphorylation of pyruvate kinase M2 regulates osteoclast differentiation and prevents pathological bone loss

Osteoclasts are primary bone-resorbing cells, and receptor-activated NF-kB ligand (RANKL) stimulation is the key driver of osteoclast differentiation. During late-stage differentiation, osteoclasts become multinucleated and enlarged (so-called "maturation"), suggesting their need to adapt to changing metabolic demands and a substantial increase in size. Here, we demonstrate that immunoglobulin superfamily 11 (IgSF11), which is required for osteoclast differentiation through an association with the postsynaptic scaffolding protein PSD-95, regulates osteoclast differentiation by controlling the activity of pyruvate kinase M isoform 2 (PKM2). By using a system that directly induces the activation of IgSF11 in a controlled manner, we identified PKM2 as a major IgSF11-induced tyrosine-phosphorylated protein. IgSF11 activates multiple Src family tyrosine kinases (SFKs), including c-Src, Fyn, and HcK, which phosphorylate PKM2 and thereby inhibit PKM2 activity. Consistently, IgSF11-deficient cells show higher PKM2 activity and defective osteoclast differentiation. Furthermore, inhibiting PKM2 activities with the specific inhibitor Shikonin rescues the impaired osteoclast differentiation in IgSF11-deficient cells, and activating PKM2 with the specific activator TEPP46 suppresses osteoclast differentiation in wild-type cells. Moreover, PKM2 activation further suppresses osteoclastic bone loss without affecting bone formation in vivo. Taken together, these results show that IgSF11 controls osteoclast differentiation through PKM2 activity, which is a metabolic switch necessary for optimal osteoclast maturation.

Inflammation and Treatment-Resistant Depression from Clinical to Animal Study: A Possible Link?

The aim of this study was to investigate the relationship between treatment-resistant depression (TRD) and inflammation in humans and experimental models. For the human study, a retrospective cohort study was conducted with 206 participants; half were on antidepressants for major depressive disorder. The patients were divided into healthy and depressed groups. Inflammation was assessed based on the values of the main inflammatory biomarkers (CRP, WBC and ESR). For the animal experiments, 35 adult male Wistar rats were assigned to stressed and non-stressed groups. Inflammation and stress were induced using lipopolysaccharide and chronic unpredictable mild stress. A 10 mg/kg intraperitoneal injection of fluoxetine (FLX), a known antidepressant, was simultaneously administered daily for 4 weeks. Behavioral tests were performed. The plasma levels of inflammatory and stress biomarkers were measured and were significantly higher in the stressed and non-responsive groups in both studies. This study provides evidence of the link between inflammation and TRD. We further observed a possible link via the Phosphorylated Janus Kinase 2 and Phosphorylated Signal Transducer and Activator of Transcription 3 (P-JAK2/P-STAT3) signaling pathway and found that chronic stress and high inflammation hinder the antidepressant effects of FLX. Thus, non-response to antidepressants could be mitigated by treating inflammation to improve the antidepressant effect in patients with TRD.

Role of prostaglandin E2 in macrophage polarization: Insights into atherosclerosis

Atherosclerosis, a trigger of cardiovascular disease, poses grave threats to human health. Although atherosclerosis depends on lipid accumulation and vascular wall inflammation, abnormal phenotypic regulation of macrophages is considered the pathological basis of atherosclerosis. Macrophage polarization mainly refers to the transformation of macrophages into pro-inflammatory (M1) or anti-inflammatory (M2) phenotypes, which has recently become a much-discussed topic. Increasing evidence has shown that M2 macrophage polarization can alleviate atherosclerosis progression. PGE₂ is a bioactive lipid that has been observed to be elevated in atherosclerosis and to play a pro-inflammatory role, yet recent studies have reported that PGE₂ promotes anti-inflammatory M2 macrophage polarization and mitigates atherosclerosis progression. However, the mechanisms by which PGE₂ acts remain unclear. This review summarizes current knowledge of PGE₂ and macrophages in atherosclerosis. Additionally, we discuss potential PGE₂ mechanisms of macrophage polarization, including CREB, NF-κB, and STAT signaling pathways, which may provide important therapeutic strategies based on targeting PGE₂ pathways to modulate macrophage polarization for atherosclerosis treatment.

The JAK-STAT Signaling Pathway in Epilepsy

Epilepsy is defined as spontaneous recurrent seizures in the brain. There is increasing evidence that inflammatory mediators and immune cells are involved in epileptic seizures. As more research is done on inflammatory factors and immune cells in epilepsy, new targets for the treatment of epilepsy will be revealed. The Janus kinase-signal transducer and transcriptional activator (JAKSTAT) signaling pathway is strongly associated with many immune and inflammatory diseases, At present, more and more studies have found that the JAK-STAT pathway is involved in the development and development of epilepsy, indicating the JAK-STAT pathway's potential promise as a target in epilepsy treatment. In this review, we discuss the composition, activation, and regulation of the JAK-STAT pathway and the relationship between the JAK-STAT pathway and epilepsy. In addition, we summarize the common clinical inhibitors of JAK and STAT that we would expect to be used in epilepsy treatment in the future.

Exploring the Potential Mechanism of Danshen in the Treatment of Concurrent Ischemic Heart Disease and Depression Using Network Pharmacology, Molecular Docking, and Molecular Dynamics Simulation

Objective: This study aimed to explore the potential targets and mechanism of action of Danshen in treating concurrent ischemic heart disease (IHD) and depression using network pharmacology, molecular docking, and molecular dynamics simulation (MDS). Methods: The Traditional Chinese Medicine Systems Pharmacology (TCMSP) database was used to obtain active ingredients and targets of Danshen. Candidate targets for IHD and depression were obtained from the Genecards and DisGeNet databases. The protein–protein interaction (PPI) network was constructed using the STRING database and the Cytoscape 3.8.2 software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed using the Metascape database and the GlueGO package of the Cytoscape 3.8.2 software. Molecular docking was performed using Autodock 1.5.6 and Vina, and the MDS was completed using GROMACS 5.1.2. Results: We obtained 65 active ingredients of Danshen with 131 candidate targets and 39 intersection targets of the active ingredients and diseases. Luteolin, tanshinone IIA, and salviolone were the core active ingredients, and AKT1, TNF, IL-6, MMP9, CASP3, IL-10, PTGS2, STAT3, PPARG, IL-4, EGFR, MAPK14, NOS3, and EDN1 were the core targets. The GO and KEGG pathway enrichment analyses revealed that the intersection targets were mainly enriched in positive regulation of protein phosphorylation, blood circulation, IL-17 signaling pathway, VEGF signaling pathway, and JAK/STAT signaling pathway. The molecular docking revealed that the core active ingredients had a good affinity for the core targets. The results of MDS revealed that the protein-ligand complexes were stable. Conclusions: This study used network pharmacology to analyze the potential mechanism of action of Danshen in the treatment of concurrent IHD and depression. Additionally, the study provided a theoretical basis for further studying the pharmacological mechanisms and targets of Danshen.

Changes in dendritic complexity and spine morphology following BCG immunization in APP/PS1 mice

Bacillus Calmette - Guerin (BCG) is an immune regulator that can enhance hippocampal synaptic plasticity in rats; however, it is unclear whether it can improve synaptic function in a mouse model with Alzheimer's disease (AD). We hypothesized that BCG plays a protective role in AD mice and investigated its effect on dendritic morphology. The results obtained show that BCG immunization significantly increases dendritic complexity, as indicated by the increased number of dendritic intersections and branch points, as well as the increase in the fractal dimension. Furthermore, the number of primary neurites and dendritic length also increased following BCG immunization, which increased the number of spines and promoted maturation. IFN-γ and IL-4 levels increased, while TNF-α levels decreased following BCG immunization; expression levels of p-JAK2, P-STAT3, SYN, and PSD-95 also increased. Therefore, this study demonstrates that BCG immunization in APP/PS1 mice mitigated hippocampal dendritic spine pathology, especially after the third round of immunization. This effect could possibly be attributed to; changes in dendritic arborization and spine morphology or increases in SYN and PSD-95 expression levels. It could also be related to mechanisms of BCG-induced increases in IFN-γ or IL-4/JAK2/STAT3 levels.

The Role of TGF-β in Cognitive Decline Associated with Radiotherapy in Brain Tumor

Cognitive decline is a late adverse event in brain tumor survivors. The patients receiving radiation treatment exhibit a wide range of damage and impairment in attention, memory, and executive function compared to the untreated group. After radiation treatment, various changes are observed in astrocytes, oligodendrocytes, white matter, and vasculature. The major affected areas are the hippocampus and prefrontal cortex. Neurogenesis impairment is one of the primary mechanisms responsible for cognitive dysfunction. Various cytokines and growth factors are responsible for inducing apoptosis of neural cells, which results in impaired neurogenesis in response to radiotherapy. Transforming growth factor (TGF-β) is one of the key cytokines released in response to radiation. TGF-β plays a major role in neuronal apoptosis through various pathways such as the MAP kinase pathway, JAK/STAT pathway, and protein kinase pathway. In contrast, activation of the ALK5 pathway via TGF-β improves neurogenesis. So, the current review article focuses on the detailed effects of TGF-β on neuronal cells concerning radiation exposure. This in-depth knowledge will help researchers focus more on the TGF-β pathway and come up with new treatment schedules which will help reduce cognitive dysfunctions in brain tumor patients produced as a result of radiation therapy.

STAT3 in medulloblastoma: a key transcriptional regulator and potential therapeutic target

Medulloblastoma is the most common malignant brain tumor of childhood accounting for about 60% of all pediatric embryonal tumors. Despite improvements in the overall survival rate, this tumor still lacks an efficient, reliable, and less toxic therapeutic approach. Characterization of the molecular mechanisms involved in medulloblastoma initiation and progression is a crucial step for the development of effective therapies. Signal transducer and activator of transcription 3 is a convergence point for several signaling cascades that are implicated in medulloblastoma tumorigenesis. Accumulated evidence has revealed the pivotal role of signal transducer and activator of transcription 3 in medulloblastoma pathogenesis such as proliferation, survival, angiogenesis, and immunosuppression as well as maintenance, drug resistance, and recurrence. In this review, we focus on the role of signal transducer and activator of transcription 3 in medulloblastoma tumorigenesis and discuss the recent advances of signal transducer and activator of transcription 3 inhibition as a promising developed strategy for medulloblastoma therapy.

Food for Thought: Leptin and Hippocampal Synaptic Function

It is well documented that the endocrine hormone, leptin controls energy homeostasis by providing key signals to specific hypothalamic nuclei. However, our knowledge of leptin’s central actions has advanced considerably over the last 20 years, with the hippocampus now established as an important brain target for this hormone. Leptin receptors are highly localised to hippocampal synapses, and increasing evidence reveals that activation of synaptically located leptin receptors markedly impacts cognitive processes, and specifically hippocampal-dependent learning and memory. Here, we review the recent actions of leptin at hippocampal synapses and explore the consequences for brain health and disease.

ATP spreads inflammation to other limbs through crosstalk between sensory neurons and interneurons

Neural circuits between lesions are one mechanism through which local inflammation spreads to remote positions. Here, we show the inflammatory signal on one side of the joint is spread to the other side via sensory neuron-interneuron crosstalk, with ATP at the core. Surgical ablation or pharmacological inhibition of this neural pathway prevented inflammation development on the other side. Mechanistic analysis showed that ATP serves as both a neurotransmitter and an inflammation enhancer, thus acting as an intermediary between the local inflammation and neural pathway that induces inflammation on the other side. These results suggest blockade of this neural pathway, which is named the remote inflammation gateway reflex, may have therapeutic value for inflammatory diseases, particularly those, such as rheumatoid arthritis, in which inflammation spreads to remote positions.

Is the JAK-STAT Signaling Pathway Involved in the Pathogenesis of Depression?

(1) Background: Only 60–70% of depressed patients respond to standard antidepressant treatments. Hence, it is essential to search for new, effective and safe therapies for unmet clinical needs of treatment-resistant depression (TRD). Agents targeting the components of the JAK-STAT signaling pathway have been shown to be relevant in immunology and are commonly used in the treatment of many hematological, rheumatological and dermatological diseases. The aim of this study was to investigate the role of elements of the JAK-STAT signaling pathway in the etiopathogenesis of depressive disorders. (2) Methods: A total of 290 subjects took part in the study (190 depressed patients, 100 healthy controls). Sociodemographic data were collected. The severity of depressive symptoms was assessed using the Hamilton Depression Rating Scale (HDRS). The gene expression at the mRNA protein levels of JAK (JAK1-JAK3) and STAT (STAT1-STAT5) was assessed by using RT-PCR and ELISA. (3) Results: Increased expression of JAK3 and decreased expression of STAT1 were observed in the group of depressed patients. (4) Conclusions: Further studies are necessary to determine whether moderation of the JAK-STAT signaling pathways is involved in the treatment of depression.

Nicotine Activating α4β2 Nicotinic Acetylcholine Receptors to Suppress Neuroinflammation via JAK2-STAT3 Signaling Pathway in Ischemic Rats and Inflammatory Cells

Nicotine plays a role in inhibiting inflammatory factors, which contributes to improving cognitive impairment by activating α₄β₂ nAChRs in ischemic rats, but the underlying mechanism has not been fully elucidated. Janus tyrosine kinase 2-signal transducer and activator of transcription 3 (JAK2-STAT3) signaling pathway is involved in cognitive improvement, and there seems to be a relationship between nAChRs and JAK2-STAT3 as well. The aim of this study is to explore the role of JAK2-STAT3 signaling pathway in nicotine-mediated anti-inflammatory effect. Nicotine, DHβE (the strongest competitive antagonist of α₄β₂ nAChRs), and AG490 (a specific JAK2-STAT3 blocker) were used to intervene and treat ischemic rats and HEK-293 T-hα₄β₂ cells. The Morris water maze (MWM) test and 2-[¹⁸F]-A-85380 PET imaging were performed to detect the cognitive function and α₄β₂ nAChRs density in ischemic rats. The results demonstrated that nicotine intervention increased the density of α₄β₂ nAChRs and improved cognitive impairment, but this effect was blocked by AG490, and the receptors were still upregulated. Essentially, when the JAK2-STAT3 signaling pathway was blocked, nicotine could only upregulate the expression of α₄β₂ nAChRs, but not improve the cognitive function. PCR and Western blot analysis further confirmed these results. The cell experiments also showed that nicotine could reduce inflammatory factors stimulated by LPS and upregulate the expression of pJAK2 and pSTAT3 in HEK-293 T-hα₄β₂ cells, while AG490 and DHβE reversed the effect of nicotine. To sum up, our work indicated that JAK2-STAT3 signaling pathway played an important role in nicotine-induced cognitive improvement by upregulating α₄β₂ nAChRs in ischemic rats.

Leptin regulation of synaptic function at hippocampal TA-CA1 and SC-CA1 synapses

Increasing evidence indicates that the metabolic hormone, leptin markedly influences the functioning of the hippocampus. In particular, exposure to leptin results in persistent changes in synaptic efficacy at both temporoammonic (TA) and Schaffer Collateral (SC) inputs to hippocampal CA1 neurons. The ability of leptin to regulate TA-CA1 and SC-CA1 synapses has important functional implications, as both synaptic connections play important roles in hippocampal-dependent learning and memory. Here we review the modulatory actions of the hormone leptin at these hippocampal CA1 synapses and explore the impact on learning and memory processes.

Possible Involvement of the IL-6/JAK2/STAT3 Pathway in the Hypothalamus in Depressive-Like Behavior of Rats Exposed to Chronic Mild Stress

INTRODUCTION

The interleukin-6/janus kinase 2/signal transducer and activator of transcription 3 (IL-6/JAK2/STAT3) pathway plays an important role in immune function, but little research has focused on this pathway in depression. We sought to examine the relationship between the IL-6/JAK2/STAT3 pathway and depressive-like behavior.

METHODS

Using a chronic mild stress (CMS) paradigm, a total of 36 adult male Sprague-Dawley rats were divided into four matched groups: (1) control + vehicle, (2) CMS + vehicle, (3) control + paroxetine, and (4) CMS + paroxetine. We investigated the effects of CMS on depressive-like behavior by using the forced swimming test (FST). Subsequently, the mRNA levels of members of the IL-6/JAK2/STAT3 pathway were assessed by qRT-PCR.

RESULTS

We found that rats exposed to CMS displayed a significant increase in immobility time and a decrease in climbing time in the FST. Moreover, mRNA levels of IL-6, JAK2, and STAT3 in the hypothalamus were increased following CMS. We also found that mRNA levels of IL-6, JAK2, and STAT3 were normalized by paroxetine administration, which coincided with normalization of the depressive-like behavior.

CONCLUSIONS

The IL-6/JAK2/STAT3 pathway may be activated in depression, and targeting this pathway may provide a novel effective therapeutic approach for the treatment of depression.

PIAS3 suppresses damage in an Alzheimer's disease cell model by inducing the STAT3-associated STAT3/Nestin/Nrf2/HO-1 pathway

BACKGROUND

Alzheimer's disease (AD), the most common form of dementia, is caused by the degeneration of the central nervous system (CNS). A previous study reported that signal transducer and activator of transcription 3 (STAT3) is activated during AD development; nonetheless, the related mechanism remains unknown. Thus, this study used a cell model to explore whether and how the protein inhibitor of activated STAT3 (PIAS3) is involved in AD development.

METHODS

Cerebrospinal fluid (CSF) specimens of 30 patients with AD and 10 normal participants were included in this study. SH-SY5Y cells were used to constructed AD model. Relevant indices were then detected and analyzed.

RESULTS

The results showed that compared with the control group, PIAS3 expression was substantially decreased in patients with AD and amyloid beta (Aβ)-treated SH-SY5Y cells. PIAS3 overexpression was able to reverse the detrimental effects of Aβ treatment on cell survival and growth. Further, it could also ameliorate apoptosis and oxidative stress in Aβ-treated SH-SY5Y cells. Additionally, PIAS3 was shown to reduce the activated form of STAT3 and increase the activity of the downstream Nestin/nuclear factor erythroid 2-related factor/heme oxygenase-1 pathway.

CONCLUSIONS

STAT3 reactivation by colivelin treatment negated the influence of PIAS3 on the survival, growth, apoptosis, and oxidative stress of Aβ-treated SH-SY5Y cells.

Prenatal interleukin 6 elevation increases glutamatergic synapse density and disrupts hippocampal connectivity in offspring

Early prenatal inflammatory conditions are thought to be a risk factor for different neurodevelopmental disorders. Maternal interleukin-6 (IL-6) elevation during pregnancy causes abnormal behavior in offspring, but whether these defects result from altered synaptic developmental trajectories remains unclear. Here we showed that transient IL-6 elevation via injection into pregnant mice or developing embryos enhanced glutamatergic synapses and led to overall brain hyperconnectivity in offspring into adulthood. IL-6 activated synaptogenesis gene programs in glutamatergic neurons and required the transcription factor STAT3 and expression of the RGS4 gene. The STAT3-RGS4 pathway was also activated in neonatal brains during poly(I:C)-induced maternal immune activation, which mimics viral infection during pregnancy. These findings indicate that IL-6 elevation at early developmental stages is sufficient to exert a long-lasting effect on glutamatergic synaptogenesis and brain connectivity, providing a mechanistic framework for the association between prenatal inflammatory events and brain neurodevelopmental disorders.

Photobiomodulation inhibits the activation of neurotoxic microglia and astrocytes by inhibiting Lcn2/JAK2-STAT3 crosstalk after spinal cord injury in male rats

BACKGROUND

Neurotoxic microglia and astrocytes begin to activate and participate in pathological processes after spinal cord injury (SCI), subsequently causing severe secondary damage and affecting tissue repair. We have previously reported that photobiomodulation (PBM) can promote functional recovery by reducing neuroinflammation after SCI, but little is known about the underlying mechanism. Therefore, we aimed to investigate whether PBM ameliorates neuroinflammation by modulating the activation of microglia and astrocytes after SCI.

METHODS

Male Sprague-Dawley rats were randomly divided into three groups: a sham control group, an SCI + vehicle group and an SCI + PBM group. PBM was performed for two consecutive weeks after clip-compression SCI models were established. The activation of neurotoxic microglia and astrocytes, the level of tissue apoptosis, the number of motor neurons and the recovery of motor function were evaluated at different days post-injury (1, 3, 7, 14, and 28 days post-injury, dpi). Lipocalin 2 (Lcn2) and Janus kinase-2 (JAK2)-signal transducer and activator of transcription-3 (STAT3) signaling were regarded as potential targets by which PBM affected neurotoxic microglia and astrocytes. In in vitro experiments, primary microglia and astrocytes were irradiated with PBM and cotreated with cucurbitacin I (a JAK2-STAT3 pathway inhibitor), an adenovirus (shRNA-Lcn2) and recombinant Lcn2 protein.

RESULTS

PBM promoted the recovery of motor function, inhibited the activation of neurotoxic microglia and astrocytes, alleviated neuroinflammation and tissue apoptosis, and increased the number of neurons retained after SCI. The upregulation of Lcn2 and the activation of the JAK2-STAT3 pathway after SCI were suppressed by PBM. In vitro experiments also showed that Lcn2 and JAK2-STAT3 were mutually promoted and that PBM interfered with this interaction, inhibiting the activation of microglia and astrocytes.

CONCLUSION

Lcn2/JAK2-STAT3 crosstalk is involved in the activation of neurotoxic microglia and astrocytes after SCI, and this process can be suppressed by PBM.

An insight into crosstalk among multiple signaling pathways contributing to epileptogenesis

Despite the years of research, epilepsy remains uncontrolled in one-third of afflicted individuals and poses a health and economic burden on society. Currently available anti-epileptic drugs mainly target the excitatory-inhibitory imbalance despite targeting the underlying pathophysiology of the disease. Recent research focuses on understanding the pathophysiologic mechanisms that lead to seizure generation and on possible new treatment avenues for preventing epilepsy after a brain injury. Various signaling pathways, including the mechanistic target of rapamycin (mTOR) pathway, mitogen-activated protein kinase (MAP-ERK) pathway, JAK-STAT pathway, wnt/β-catenin signaling, cAMP pathway, and jun kinase pathway, have been suggested to play an essential role in this regard. Recent work suggests that the mTOR pathway intervenes epileptogenesis and proposes that mTOR inhibitors may have antiepileptogenic properties for epilepsy. In the same way, several animal studies have indicated the involvement of the Wnt signaling pathway in neurogenesis and neuronal death induced by seizures in different phases (acute and chronic) of seizure development. Various studies have also documented the activation of JAK-STAT signaling in epilepsy and cAMP involvement in epileptogenesis through CREB (cAMP response element-binding protein). Although studies are there, the mechanism for how components of these pathways mediate epileptogenesis requires further investigation. This review summarises the current role of various signaling pathways involved in epileptogenesis and the crosstalk among them. Furthermore, we will also discuss the mechanical base for the interaction between these pathways and how these interactions could be a new emerging promising target for future epilepsy therapies.

Further insights for the role of Morin in mRTBI: Implication of non-canonical Wnt/PKC-α and JAK-2/STAT-3 signaling pathways

The slightly available data about the pathogenesis process of mild repetitive traumatic brain injury (mRTBI) indicates to the necessity of further exploration of mRTBI consequences. Several cellular changes are believed to contribute to the cognitive disabilities, and neurodegenerative changes observed later in persons subjected to mRTBI. We investigated glial fibrillary acidic protein (GFAP), the important severity related biomarker, where it showed further increase after multiple trauma compared to single one. To authenticate our aim, Morin (10 mg/kg loading dose, then twice daily 5 mg/kg for 7 days), MK-801 (1 mg/kg; i.p) and their combination were used. The results obtained has shown that all the chosen regimens opposed the upregulated dementia markers (Aβ1-40,p(Thr231)Tau) and inflammatory protein contents/expression of p(Ser53s6)NF-κBp65, TNF-α, IL-6,and IL-1β and the elevated GFAP in immune stained cortex sections. Additionally, they exerted anti-apoptotic activity by decreasing caspase-3 activity and increasing Bcl-2 contents. Saving brain tissues was evident after these therapeutic agents via upregulating the non-canonical Wnt-1/PKC-α cue and IL-10/p(Tyr(1007/1008))JAK-2/p(Tyr705)STAT-3 signaling pathway to confirm enhancement of survival pathways on the molecular level. Such results were imitated by correcting the injury dependent deviated behavior, where Morin alone or in combination enhanced behavior outcome. On one side, our study refers to the implication of two survival signaling pathways; viz.,the non-canonical Wnt-1/PKC-α and p(Tyr(1007/1008))JAK-2/p(Tyr705)STAT-3 in single and repetitive mRTBI along with distorted dementia markers, inflammation and apoptotic process that finally disrupted behavior. On the other side, intervention through affecting all these targets by Morin alone or with MK-801 affords a promising neuroprotective effect.

The Circadian Rhythms of STAT3 in the Rat Pineal Gland and Its Involvement in Arylalkylamine-N-Acetyltransferase Regulation

In rodents, the melatonin production by the pineal gland is controlled through adrenergic signaling from the suprachiasmatic nuclei and regulation of the principal enzyme in its synthesis, arylalkylamine-N-acetyltransferase (AANAT). In the present study, we identified increased isoprenaline-induced aa-nat expression and nocturnal AANAT activity in the pineal glands in response to the silencing of the signal transducer and activator of transcription 3 (STAT3) with siRNA or STAT3 inhibitors WP1066 and AZD1480. This AANAT activity enhancement in vivo did not interfere with light-induced AANAT suppression. Systemic or in vitro lipopolysaccharide (LPS) administration markedly increased Stat3 expression and STAT3 phosphorylation, but it did not significantly affect AANAT expression or activity. Simultaneous LPS administration and Stat3 silencing enhanced the aa-nat transcription and AANAT activity to a similar extent as Stat3 inhibition without LPS co-administration. Furthermore, we describe the circadian rhythmicity in Stat3 expression and the phosphorylated form of STAT3 protein in the rat pineal gland. Our data suggest that the higher nocturnal endogenous level of STAT3 in the pineal gland decelerates or hampers the process of NA-induced AANAT activation or affects the AANAT enzyme stability.