Immunotherapy has revolutionized cancer treatment, yet its efficacy in hepatocellular carcinoma (HCC) remains limited and the mechanisms of resistance are poorly defined. Using in vivo CRISPR-Cas9 screens, we identify serine/threonine kinase 40 (STK40) as a previously unrecognized regulator of immune evasion. Stk40 ablation synergizes with PD-1 blockade to induce tumor regression. Hepatocyte-specific Stk40 deletion abolishes tumorigenesis in hydrodynamic plasmid-driven HCC models. Mechanistically, STK40 scaffolds the COP1 ubiquitin ligase to promote interferon gamma receptor 1 (IFNGR1) degradation. Genetic depletion of Stk40 stabilizes IFNGR1, restoring tumor cell sensitivity to T cell cytotoxicity. Concurrently, Stk40 loss triggers autonomous GM-CSF secretion, enhancing the infiltration and activation of conventional type 1 dendritic cells, which promotes antigen cross-presentation and CD8+ T cell activation. Pharmacological inhibition of STK40 using LNP-siRNA, combined with PD-1 blockade, elicits potent anti-tumor responses across multiple cancer types. These findings establish STK40 as a dual-action therapeutic target to overcome resistance to anti-tumor immunity.

Depression is one of the most prevalent psychiatric disorders worldwide, yet its pathogenesis remains unclear. Here, we aimed to investigate the effects of formyl peptide receptor 2 (FPR2), a key regulator of innate immunity and inflammation, on lipopolysaccharide (LPS)-induced depression-related behaviors in mice after intraperitoneal administration, and to elucidate its regulatory mechanisms in microglia. FPR2 knockout (Fpr2–/–) significantly attenuated LPS-induced depressive and anxiety-like behaviors in mice. LPS markedly increased FPR2 expression in microglia of the prefrontal cortex (PFC) and hippocampus, while only a minimal increase was observed in neurons. FPR2 deficiency alleviated LPS-induced microglial activation and reduced neuronal synaptic alterations. RNA sequencing and validation experiments confirmed that FPR2 deletion substantially decreased LPS-induced microglial NLRP3 inflammasome activation and IL-1β levels in the brain. Mechanistically, FPR2 regulated downstream NLRP3 activation by modulating CSF1, and FPR2/CSF1 activation was governed by its upstream ligand, serum amyloid A (SAA). Analysis of public clinical datasets revealed that SAA1 levels were significantly upregulated in the orbital ventral PFC of patients with major depressive disorder (MDD) and in the plasma of patients with late-life depression. These findings demonstrate that the SAA/FPR2/CSF1/NLRP3 pathway mediates LPS-induced depressive-like behaviors by regulating microglial activation and neuroinflammation.

Inducing the selective ablation of specific cell types is a powerful approach for studying complex cell-cell interactions, particularly within the immune system. While systemic depletion of immune cells can be achieved using chemicals or cytotoxic antibodies, the diphtheria toxin receptor (DTR)-diphtheria toxin (DT) system provides a more targeted, cost-effective, and minimally invasive alternative. The system leverages the fact that human DTR has a 103-105 times higher affinity for DT compared to rodent cells. This allows selective cell ablation in mice by introducing the human DTR gene into specific cell populations and subsequently administering DT in vivo. Using CRISPR/Cas9 technology, we generated a series of DTR mouse models targeting immune cell types, including CD8, Ncr1, Foxp3, CD11c, and seven additional cell-specific targets. These models were created on C57BL/6 or BALB/c genetic backgrounds, with the human DTR coding sequence driven by murine endogenous promoters. Successful gene insertions were validated using GFP or Tomato fluorescent reporter expression. Upon DT administration, these engineered DTR mice exhibited transient immune cell ablation within 48 hours, with cell levels recovering to baseline within 96 hours in the absence of repeated DT dosing. For functional validation, we used the Ncr1-DTR mouse model in an MC38 tumor inoculation study. DT treatment effectively depleted natural killer (NK) cells in the blood, highlighting the model's utility for immune cell depletion in specific experimental contexts. Overall, these results demonstrate that DTR mouse models are robust tools for dissecting immune cell functions, exploring intercellular interactions, and evaluating the mechanisms of immune-based therapies. Yang Yu, Yi Li, Hechun Ma, Shuang Li, Ruilin Sun. Development and application of DTR mouse models for immune cell ablation and tumor immunotherapy studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6847.

Ischemic stroke (IS) leads to the disruption of blood-brain barrier (BBB) integrity, resulting in brain edema. In this process, endothelial cells, as a crucial component of the BBB, are subjected to external pressure and tensile stress. Piezo1, a mechanically-sensitive ion channel, may be activated by sensing these stresses, further exacerbating the destruction of the BBB. Our findings indicated that after cerebral ischemia/reperfusion (I/R) injury, the expression of Piezo1 in endothelial cells increased. In endothelial-specific Piezo1 knockout (Piezo1ECKO) mice, brain damage, neurological deficits, and BBB disruption caused by I/R injury were significantly alleviated. Moreover, oxidative stress and the inflammatory response in the cerebral cortex induced by I/R were also reduced. In vitro, by activating or knocking out Piezo1 in bEnd.3 cells under oxygen-glucose deprivation/reperfusion (OGD/R), we observed similar effects, further corroborating the in vivo findings. To elucidate the molecular mechanism, we found that the protective effect of Piezo1 deficiency on BBB integrity is mediated by the alleviation of p-CaMKII and the enhancement of Nrf2 nuclear translocation. This, in turn, leads to the upregulation of NQO-1 and HO-1 expression. In summary, our research indicates that Piezo1 exacerbates BBB disruption after cerebral I/R injury by promoting oxidative stress, inflammation, and mitochondrial dysfunction. This process is closely linked to the activation of the Ca2+/CaMKII and Nrf2 pathways, suggesting that Piezo1 may be a potential therapeutic target for IS.

With an aging population, the incidence of obstructive sleep apnea syndrome (OSAS) is rising, resulting in a growing number of patients undergoing surgery who are also affected by OSAS. The combined impact of anesthetic drugs and OSAS-related neurological damage has drawn significant attention. Here, wild-type (WT) and Tau-knockout (Tau-KO) mice were subjected to intermittent hypoxia and sevoflurane exposure to induce OSAS and sevoflurane-induced neurotoxicity. Protein expression of tau phosphorylation (Tau-Ser202/Thr205 and Tau-Ser422) was measured by Western blotting. Immunofluorescence was used to visualize tau phosphorylation (Tau-Ser202/Thr205) in the hippocampal CA1 region. Mitochondrial function was evaluated by measuring reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and ATP levels. Cognitive functions were assessed using the Morris water maze and Y-maze tests. We found that compared to the WT OSAS group, sevoflurane significantly increased tau phosphorylation and mitochondrial dysfunction in WT OSAS mice, leading to cognitive impairment. Interestingly, idebenone treatment mitigated sevoflurane-induced mitochondrial dysfunction and cognitive impairment in WT OSAS mice, but it did not affect tau phosphorylation. Compared to the Tau-KO control group, Tau-KO OSAS mice exhibited mitochondrial dysfunction and cognitive impairment, but sevoflurane did not exacerbate mitochondrial dysfunction or cognitive impairment in these mice. These findings suggest that sevoflurane exacerbates cognitive impairments in OSAS mice through tau phosphorylation-induced mitochondrial dysfunction, but also uncovered differing mechanisms between cognitive impairments induced by OSAS and those exacerbated by sevoflurane.

Neuroinflammation, a significant contributor to secondary brain injury, plays a critical role in the pathological process and prognosis of intracerebral haemorrhage (ICH). Thus, developing interventions to mitigate secondary neuroimmune deterioration is of paramount importance. Currently, no effective immunomodulatory drugs are available for ICH. The cyclic GMP-AMP synthase (cGAS)−stimulator of interferon genes (STING) pathway is a recently identified innate immune-sensing pathway primarily expressed in microglia within the central nervous system (CNS) that has been implicated in the pathophysiology of various neurological diseases. In this study we investigated the role of cGAS-STING pathway in ICH. A collagenase model of ICH was established in mice. Brain tissues were collected on D1 or D3 post-ICH. We observed a significant increase in double-stranded (dsDNA) levels and activation of the cGAS-STING pathway in the perihaematomal region of ICH mice. Administration of a blood brain barrier-permeable STING antagonist H151 (10 mg/kg, i.p.) significantly decreased cell apoptosis, alleviated hematoma growth, and improved motor impairments in ICH mice, accompanied by inhibiting the STING pathway in microglia, reducing production/release of the cGAS-STING pathway downstream inflammatory factors, NLRP3 inflammasome activation and gasdermin D (GSDMD)-induced microglial pyroptosis. Microglial Sting conditional knockout significantly mitigated ICH-induced neuroinflammatory responses, pathological damage and motor dysfunction. These results suggest that the microglial STING pathway promotes brain pathological damage and behavioural defects in ICH mice by activating the NLRP3 inflammasome and microglial pyroptosis. The STING pathway may serve as a potential therapeutic target for ICH-induced secondary brain injury.

Social isolation (SI) is a prevalent issue in modern society, particularly exacerbated during the COVID-19 pandemic, and it is a significant contributor to depressive disorders. Inflammation-related markers are upregulated in patients with major depressive disorder (MDD) unresponsive to first-line selective serotonin reuptake inhibitor (SSRI) antidepressants. This study investigates the role of formyl peptide receptor 2 (FPR2), a G-protein coupled receptor expressed in central and peripheral immune cells, in SI-induced depression. We developed a mouse model of SI by housing mice individually for three weeks. SI mice exhibited increased capillary-associated microglia (CAMs) with upregulated FPR2 expression in the prefrontal cortex (PFC) and hippocampus compared to group-housed controls. Notably, subcutaneous administration of the FPR2 antagonist WRW4 alleviated depressive and anxiety-like behaviors in SI mice, reducing microglial activation and neuronal damage. WRW4 treatment decreased CAM numbers and their FPR2 expression. RNA sequencing revealed that SI primarily induced changes in genes associated with blood-brain barrier (BBB) function, followed by alterations in genes related to hormone activity, immune activation, and neuronal function. Transcriptomic changes in brain endothelial cells from SI mice resembled those observed in animal models of several neurological disorders and in MDD patients. WRW4 treatment partially reversed these transcriptomic alterations and restored compromised BBB integrity. Additionally, intracerebroventricular (ICV) injection of WRW4 also alleviated depressive and anxiety-like behaviors in SI mice. Finally, our analysis of public transcriptome databases indicates FPR2 upregulation in the orbital ventral PFC of MDD patients and peripheral blood mononuclear cells of those in severe depressive episodes. These findings suggest that the pharmacological targeting of FPR2 may rescue SI-induced pathology in mice by protecting BBB integrity.

BACKGROUND:In the development of several cancers, the Forkhead Box M1 (FOXM1) is crucial. The relationship between the immune system and FOXM1 in renal cell carcinoma (ccRCC), which has been verified by bulk RNA sequencing and scRNA sequencing, is the primary subject of this research. METHOD:Publicly available data related to FOXM1 and ccRCC were extracted from The Cancer Genome Atlas (TCGA) database. The impact of FOXM1 on the prognosis of ccRCC was examined using Cox regression analysis. Results were verified by immunohistochemistry and quantitative real-time PCR (qRT-PCR). Additionally, single-cell sequencing data were analyzed. RESULTS:When compared to para-carcinoma tissues, the expression of FOXM1 was considerably higher in ccRCC tissues. Patients with elevated FOXM1 expression had lower survival rates. FOXM1 may be a standalone prognostic factor for ccRCC, according to results of univariate and multivariate Cox regression studies. Reduced FOXM1 expression was linked to higher immunotherapy sensitivity, according to immunocorrelation analysis. This suggests FOXM1 may mediate immunotherapy resistance in ccRCC. Additionally, FOXM1 showed strong associations with tumor mutation load, microsatellite instability, and antitumor immunity. These results imply FOXM1 may regulate antitumor immunity in the ccRCC microenvironment. Consistent results from immunohistochemistry, PCR, and single-cell RNA sequencing confirmed upregulated FOXM1 expression in ccRCC. CONCLUSIONS:According to the findings, FOXM1 might be used as a stand-alone prognostic biomarker for ccRCC. Moreover, FOXM1 has exhibited robust correlations with microsatellite instability, tumor mutation burden, immune response, and immunotherapy efficacy. FOXM1 may promote ccRCC pathogenesis partly by suppressing antitumor immunity and mediating immunotherapy resistance.

Recruitment and accumulation of reactive astrocytes around senile plaques are common pathological features of Alzheimer’s disease (AD), with unclear mechanisms. Chemerin, an adipokine implicated in neuroinflammation, acts through its receptor, chemokine-like receptor 1 (CMKLR1), which also functions as a receptor for amyloid β (Aβ). The impact of the chemerin/CMKLR1 axis on astrocyte migration towards Aβ plaques is unknown. Here we investigated the effect of CMKLR1 on astrocyte migration around Aβ deposition in APP/PS1 mice with Cmklr1 knockout (APP/PS1-Cmklr1−/−). CMKLR1-expressed astrocytes were upregulated in the cortices and hippocampi of 9-month-old APP/PS1 mice. Chemerin mainly co-localized with neurons, and its expression was reduced in the brains of APP/PS1 mice, compared to WT mice. CMKLR1 deficiency decreased astrocyte colocalization with Aβ plaques in APP/PS1-Cmklr1−/− mice, compared to APP/PS1 mice. Activation of the chemerin/CMKLR1 axis promoted the migration of primary cultured astrocytes and U251 cells, and reduced astrocyte clustering induced by Aβ42. Mechanistic studies revealed that chemerin/CMKLR1 activation induced STING phosphorylation. Deletion of STING attenuated the promotion of the chemerin/CMKLR1 axis relative to astrocyte migration and abolished the inhibitory effect of chemerin on Aβ42-induced astrocyte clustering. These findings suggest the involvement of the chemerin/CMKLR1/STING pathway in the regulation of astrocyte migration and recruitment to Aβ plaques/Aβ42.

Pumilio RNA-binding family member 1 (PUM1) has been implicated in both the progression of colorectal cancer and the regulation of inflammation. The role of PUM1 in the polarization of tumor-associated macrophages (TAMs) into the M2 phenotype has not yet been reported in hepatocellular carcinoma. Using the PUM1-knockout mice model, flow cytometry, and IHC, we validated the role of PUM1 in hepatocellular carcinoma (HCC) TAMs. One-way analysis of variance (ANOVA) or student's t-tests was used to compare the experimental groups. We found that PUM1 inhibited anti-tumor immunity in HCC through TAM-mediated inhibition of CD8+ T cells. We also showed that PUM1 promotes the transformation of TAMs into pro-tumorigenic M2-like phenotypes by activating cAMP signaling pathway. This study emphasized the potential of PUM1 as a target for immunotherapy in HCC through TAMs. The present study revealed the molecular mechanism underlying the pro-tumor role of PUM1 in HCC.

Background: Tumor metastasis is one of the leading causes of poor prognosis for colorectal cancer (CRC) patients. Loss of Smad4 contributes to aggression process in many human cancers. However, the underlying precise mechanism of aberrant Smad4 expression in CRC development is still little known.Results: miR-20a-5p negatively regulated Smad4 by directly targeting its 3'UTR in human colorectal cancer cells. miR-20a-5p not only promoted CRC cells aggression capacity in vitro and liver metastasis in vivo, but also promoted the epithelial-to-mesenchymal transition process by downregulating Smad4 expression. In addition, tissue microarray analysis obtained from 544 CRC patients' clinical characters showed that miR-20a-5p was upregulated in human CRC tissues, especially in the tissues with metastasis. High level of miR-20a-5p predicted poor prognosis in CRC patients.Methods: Five miRNA target prediction programs were applied to identify potential miRNA(s) that target(s) Smad4 in CRC. Luciferase reporter assay and transfection technique were used to validate the correlation between miR-20a-5p and Smad4 in CRC. Wound healing, transwell and tumorigenesis assays were used to explore the function of miR-20a-5p and Smad4 in CRC progression in vitro and in vivo. The association between miR-20a-5p expression and the prognosis of CRC patients was evaluated by Kaplan-Meier analysis and multivariate cox proportional hazard analyses based on tissue microarray data.Conclusions: miR-20a-5p, as an onco-miRNA, promoted the invasion and metastasis ability by suppressing Smad4 expression in CRC cells, and high miR-20a-5p predicted poor prognosis for CRC patients, providing a novel and promising therapeutic target in human colorectal cancer.

To explore the mechanism of action of asperosaponin VI (AVI) in the treatment of rheumatoid arthritis (RA) and validate it in ex vivo experiments using network pharmacology and molecular docking methods. The predicted targets of AVI were obtained from PharmMaper, UniProt and SwissTarget Prediction platforms, the disease targets were collected from Online Mendelian Inheritance in Man, Therapeutic Target Database and GeneCards databases, the intersection targets of AVI and RA were obtained from Venny 2.1.0, and the protein-protein interaction (PPI) network was obtained from STRING database, which was analyzed by Cytoscape software and screened to obtain the core targets. Cytoscape software was used to analyze PPI network and screen the core targets. Based on the Database for Annotation, Visualization and Integrated Discovery database, Gene Ontology functional and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed, and Cytoscape software was used to construct the “Disease-Pathway-Target-Drug” network, which was finally verified by molecular docking and animal experiments. Network pharmacological studies showed that AVI was able to modulate 289 targets, with 102 targets for the potential treatment of RA, with the core pathway being the AKT/PI3K signaling pathway, and the core targets being the epidermal growth factor receptor (EGFR) and matrix metalloproteinase 9 (MMP9). Molecular docking results showed that AVI could produce strong binding with both of the 2 core targets. In vitro cellular experiments showed that AVI reduced nitric oxide, prostaglandin E2, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IL-1 β levels (P<0.05) and inhibited cyclooxygenase-2, nitric oxide synthase, EGFR, MMP9, phosphorylated phosphoinositide 3-kinase (p-PI3K), and phosphorylated serine-threonine kinase (p-AKT) proteins (P<0.05). The results of in vivo studies showed that AVI improved RA score and foot swelling thickness and decreased TNF-α, IL-6, p-PI3K and p-AKT levels in RA rats (P<0.05). AVI exerts anti-inflammatory and anti-RA effects which might be related to the EGFR/MMP9/AKT/PI3K pathway.

Alzheimer’s disease (AD) is a common progressive degenerative disease of the central nervous system in aging populations. This study aimed to investigate the effects of combined catalpol and tetramethylpyrazine (CT) in promoting axonal plasticity in AD and the potential underlying mechanism. Astrocytes were treated with different concentrations of compatible CT. Exosomes were collected and subjected to sequencing analysis, which was followed by the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of differentially expressed genes. Amyloid precursor protein/presenilin 1 (APP/PS1) double-transfected male mice were used as the in vivo AD models. Astrocyte-derived exosomes that were transfected with cyclin-dependent kinase 5 (CDK5) or CT treatment were injected into the tail vein of mice. The levels of CDK5, synaptic plasticity marker protein neurofilament 200 (NF200), and growth-associated protein 43 (GAP-43) in the hippocampus of mice were compared in each group. Immunofluorescence staining was used to detect the localization of STAT3 and to visualize synaptic morphology via β-tubulin-III (TUBB3). Astrocyte-derived exosomes transfected with siCDK5 or treated with CT were co-cultured with HT-22 cells, which were untransfected or silenced for signal transducer and activator of transcription 3 (STAT3). Amyloid β-protein (Aβ)1–42 was induced in the in vitro AD models. The viability, apoptosis, and expression levels of NF200 and GAP-43 proteins in the hippocampal neurons of each group were compared. In total, 166 differentially expressed genes in CT-induced astrocyte-derived exosomes were included in the KEGG analysis, and they were found to be enriched in 12 pathways, mainly in axon guidance. CT treatment significantly increased the level of CDK5 mRNA in astrocyte-derived exosomes—these exosomes restored CDK5 mRNA and protein levels in the hippocampus of the in vivo AD model mice and the in vitro AD model; promoted p-STAT3 (Ser727), NF200 and GAP-43 proteins; and promoted the regeneration and extension of neuronal synapses. Silencing of CDK5 blocked both neuronal protection as well as induction of axonal plasticity in AD by CT-treated exosomes in vitro and in vivo. Moreover, silencing of STAT3 blocked both neuronal protection as well as induction of axonal plasticity in AD caused by CDK5 overexpression or CT-treated astrocyte-induced exosomes. CT promotes axonal plasticity in AD by inducing astrocytes to secrete exosomes carrying CDK5 mRNA and regulating STAT3 (Ser727) phosphorylation.

Objective. Surface electromyography (EMG) decomposition techniques have been developed to decode motor neuron activities non-invasively in the past decades, showing superior performance in human-machine interfaces such as gesture recognition and proportional control. However, neural decoding across multiple motor tasks and in real-time remains challenging, which limits its wide application. In this work, we proposed a real-time hand gesture recognition method by decoding motor unit (MU) discharges across multiple motor tasks ( $>$ 10) in a motion-wise way. Methods. The EMG signals were first divided into numerous segments related to motions. The convolution kernel compensation algorithm was applied for each segment individually. The local MU filters, which indicate the MU-EMG correlation for each motion, were calculated iteratively in each segment and reused for global EMG decomposition to trace the MU discharges across motor tasks in real-time. The motion-wise decomposition method was applied on the high-density EMG signals recorded during twelve hand gesture tasks from eleven non-disabled participants. The neural feature of discharge count was extracted for gesture recognition based on five common classifiers. Main results. On average, 164 $\pm$ 34 MUs were identified for twelve motions from each subject, with a pulse-to-noise ratio of 32.1 $\pm$ 5.6 dB. The average time cost of EMG decomposition in a sliding window of 50 ms was less than 5 ms. The average classification accuracy using a linear discriminant analysis classifier was 94.6 $\pm$ 8.1%, which was significantly higher than that of a time-domain feature called root mean square. The superiority of the proposed method was also validated with a previously published EMG database comprising 65 gestures. Conclusion and Significance. These results indicate the feasibility and superiority of the proposed method for MU identification and hand gesture recognition across multiple motor tasks, extending the potential applications of neural decoding in human-machine interfaces.

Alzheimer’s Disease (AD) contributes to most cases of dementia. Its prominent neuropathological features are the extracellular neuritic plaques and intercellular neurofibrillary tangles composed of aggregated β-amyloid (Aβ) and hyperphosphorylated tau protein, respectively. In the past few decades, disease-modifying therapy targeting Aβ has been the focus of AD drug development. Even though it is encouraging that two of these drugs have recently received accelerated US Food and Drug Administration approval for AD treatment, their efficacy or long-term safety is controversial. Tau has received increasing attention as a potential therapeutic target, since evidence indicates that tau pathology is more associated with cognitive dysfunction. Moreover, inflammation, especially neuroinflammation, accompanies AD pathological processes and is also linked to cognitive deficits. Accumulating evidence indicates that inflammation has a complex and tight interplay with tau pathology. Here, we review recent evidence on the interaction between tau pathology, focusing on tau post-translational modification and dissemination, and neuroinflammatory responses, including glial cell activation and inflammatory signaling pathways. Then, we summarize the latest clinical trials targeting tau and neuroinflammation. Sustained and increased inflammatory responses in glial cells and neurons are pivotal cellular drivers and regulators of the exacerbation of tau pathology, which further contributes to its worsening by aggravating inflammatory responses. Unraveling the precise mechanisms underlying the relationship between tau pathology and neuroinflammation will provide new insights into the discovery and clinical translation of therapeutic targets for AD and other tau-related diseases (tauopathies). Targeting multiple pathologies and precision therapy strategies will be the crucial direction for developing drugs for AD and other tauopathies.

Supplementary Figures and Tables. // Figure S1, Survival fractions. Figure S2, Linearity of bioluminescence signals vs. Fluc-GFP-labeled tumor cell numbers. Figure S3, Cisplatin-induced dying tumor cells stimulated living tumor cell growth. Figure S4, DN_PKCÎ' (K378A) stably transduced HT-29 cells showed less growth stimulation effect when compared with wild-type HT-29 cells. Figure S5, A specific HIF1α inhibitor PX-478 2HCl remarkably suppressed the reporter cell growth on irradiated feeder cells. // Table S1, Summary of clinical characteristics in 68 patients of colorectal cancer.