1.Activation of the Gamma-Aminobutyric Acid (GABA)ergic Neural Circuit in Salicylate-Induced Tinnitus: the Inferior Colliculus to the Medial Geniculate Body
Xu-Yuan PENG ; Jiang WANG ; Ming-Yue GONG ; Li-Yuan ZHANG ; Min ZHANG ; Zhi-Bin CHEN ; Zheng-Quan TANG ; Lei CHENG
Clinical and Experimental Otorhinolaryngology 2026;19(1):55-69
Objectives:
. This study aimed to investigate the regulatory functions of gamma-aminobutyric acid (GABA)ergic neural circuits from the inferior colliculus (IC) to the medial geniculate body (MGB) in salicylate-induced tinnitus.
Methods:
. Mice were treated with salicylate to induce tinnitus, and tinnitus-like behaviors were evaluated via gap prepulse inhibition of acoustic startle. Using combined viral tracing methodologies, we identified and mapped the pathways and connections from the IC to the MGB. Furthermore, we employed Gq-coupled human M3 designer receptors exclusively activated by designer drugs (DREADDs) and Gi-coupled human M4 DREADDs to achieve targeted excitation or suppression of GABAergic neurons in the IC and MGB. Following the administration of clozapine N-oxide, which binds to these receptors, we modulated these neural circuits to assess their impact on tinnitus severity in a mouse model.
Results:
. Our findings demonstrated that mice exposed to salicylate exhibited tinnitus-like behaviors. GABAergic neurons projecting retrogradely from the MGB to the IC were primarily concentrated in the external nucleus of the IC. After clozapine N-oxide administration, chemogenetic activation of IC-MGB GABAergic neurons aggravated salicylate-induced tinnitus. Additionally, activation of GABAergic neurons between the IC and MGB induced the perception of tinnitus even without salicylate. However, chemogenetic inhibition of the IC-MGB GABAergic circuit did not reverse salicylate-induced tinnitus.
Conclusion
. These findings suggest that activation of the IC-MGB GABAergic neural circuit may contribute to tinnitus generation through a mechanism distinct from that of salicylate-induced tinnitus. This study provides novel insights into the mechanisms underlying tinnitus.
2.Differences in deltamethrin resistance and kdr gene mutation in Culex tritaeniorhynchus population in and outside the Yellow Sea wetland
Xiao-er ZHANG ; Zhi-ming WU ; Ye TIAN ; Qian CUI ; Yu-qian JI ; Huan WANG ; Shu-juan YANG ; Yi-chao ZHAO ; Yu WANG ; Hua-yu YIN ; Yu DING ; Guo-jin YAN ; Min-sen ZHAO ; Shou-gang ZHANG ; Bing-dong SONG ; Hong-na CHEN ; Jian GAO ; Wei-fang YANG ; Yu-fu ZHANG ; Hui LIU ; Hong-liang CHU
Acta Parasitologica et Medica Entomologica Sinica 2026;33(2):101-107
Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.
3.Dual Targeting of TBK1 and JAK-STAT1 Pathways by (-)-epigallocatechin-3-gallate Suppresses Type I Interferon-driven Inflammation
Liang LI ; Qi-Huan SHENG ; Huan LIU ; Wen-Hao YANG ; Jia-Lin SHI ; Ying-Jie SUN ; Rui JING ; Wei-Hua MAI ; Zhi-Min LI ; Xiao-Li XIE
Progress in Biochemistry and Biophysics 2026;53(7):1969-1983
ObjectiveType I interferon (IFN-I) signaling is essential for antiviral innate immunity, yet its sustained or excessive activation contributes to the pathogenesis of several autoimmune diseases and interferonopathies, such as systemic lupus erythematosus and Aicardi-Goutières syndrome. Current strategies targeting this pathway, exemplified by JAK inhibitors, act mainly on downstream signal transduction and provide limited direct control over upstream IFN-I production, while also carrying the risk of broad immunosuppression. Phyllanthus emblica L. has long been used in traditional medicine for inflammatory disorders, but the bioactive constituent responsible for its regulation of IFN-I signaling and the underlying molecular mechanism have not been clearly defined. This study aimed to identify the active anti-inflammatory component of P. emblica and to characterize its mechanism of action on the IFN-I pathway in macrophages. MethodsActive components ofP. emblica and their candidate targets were screened by network pharmacology using the TCMSP and DrugBank databases (oral bioavailability≥30%, drug-likeness≥0.18) and intersected with inflammation-related genes retrieved from public databases. The predicted interaction between EGCG and IFN-I pathway proteins (TBK1, IRF3, STAT1) was evaluated by molecular docking, with BX795 and GSK8612 used as reference TBK1 inhibitors. Mechanistic experiments were performed in THP-1-derived macrophages and primary bone marrow-derived macrophages (BMDM). Upstream signaling was activated by transfection of the nucleic acid analogs poly(I∶C) and poly(dA∶dT) or by lipopolysaccharide (LPS) stimulation, whereas downstream signaling was activated by exogenous IFN-β. An siRNA-mediated TREX1 knockdown model was used to mimic endogenous nucleic acid-driven interferonopathy. Expression of IFN-β1 and interferon-stimulated genes (ISGs) was measured by RT-qPCR, protein phosphorylation by Western blot, and IFN-β secretion by ELISA. Cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) were used to probe the interactionbetween EGCG and IRF3. ResultsNetwork pharmacology identified (-)-epigallocatechin-3-gallate (EGCG) as a candidate IFN-I-suppressive constituent of P. emblica, with predicted binding to TBK1, IRF3, and STAT1. Molecular docking yielded binding energies of -9.2, -7.2, and -8.2 kcal/mol for TBK1, IRF3, and STAT1, respectively, indicating an affinity for TBK1 comparable to that of the reference inhibitors BX795 (-5.7 kcal/mol) and GSK8612 (-6.4 kcal/mol). EGCG suppressed IFN-β1 and ISG mRNA expression under poly (I∶C), poly (dA∶dT), and LPS stimulation in both THP-1 macrophages and BMDM. At the protein level, EGCG reduced the phosphorylation of TBK1 and IRF3 without affecting the levels of the upstream sensors cGAS and RIG-I, and lowered IFN-β secretion in a concentration-dependent manner. CETSA and DARTS showed that EGCG did not enhance the thermal stability or protease resistance of IRF3, indicating that its effect on IRF3 is indirect. Following IFN-β stimulation, prolonged EGCG treatment reduced STAT1 phosphorylation in a time-dependent manner without an apparent change in IRF9, and partially attenuated ISG transcription; this effect was not monotonicly concentration-dependent, and CXCL10 showed the most consistent suppression. In TREX1-knockdown cells, the elevated mRNA levels of ISG15, ISG56, and CXCL10 were reduced by EGCG. ConclusionEGCG suppresses IFN-I responses by concurrently inhibiting TBK1-IRF3-dependent IFN‑β production and JAK-STAT1-mediated downstream transcription. These in vitro findings provide a mechanistic basis for the anti-inflammatory use of P. emblica in traditional medicine and identify EGCG as a candidate for further evaluation in interferon-driven autoimmune disease models.
4.Technique and Application of Deep Learning-based EEG Denoising
Bao-Lian SHAN ; Hai-Qing YU ; Yong-Zhi HUANG ; Jia-Yuan MENG ; Min-Peng XU ; Tzyy-Ping JUNG ; Dong MING
Progress in Biochemistry and Biophysics 2026;53(8):2147-2160
Electroencephalography (EEG) is a non-invasive neurophysiological monitoring technique. It records the electrical activity of the cerebral cortex using electrodes placed on the scalp surface. Owing to its high safety, portability, and millisecond-level temporal resolution, EEG has been widely utilized in a variety of fields, including clinical diagnosis, brain-computer interfaces (BCIs), and cognitive neuroscience research. However, due to its microvolt-level amplitude, EEG is highly susceptible to various artifacts, including electrooculographic (EOG), electrocardiographic (ECG), electromyographic (EMG), and power line interference (PLI). These artifacts can obscure genuine neural activity and introduce spurious electrophysiological features. Consequently, they may compromise EEG signal quality, thereby reducing the reliability of downstream analyses. To address this issue, numerous EEG artifact removal methods have been developed, including both traditional denoising techniques and deep learning-based approaches. Traditional EEG denoising methods have long served as the primary solutions for artifact removal. Representative approaches include filtering, regression, and blind source separation. Although these methods have demonstrated effectiveness in specific scenarios, they suffer from several inherent limitations. Filtering assumes that artifacts and EEG signals can be separated in the frequency domain, but many artifacts, such as EOG and EMG, overlap with EEG spectra, which may lead to the loss of valuable neural information. Regression methods require high-quality artifact references to estimate and subtract contaminations, limiting their effectiveness in reference-free scenarios. Blind source separation can remove artifacts without external references, but it typically requires the number of EEG channels to exceed the number of sources, restricting its application in single- or low-channel EEG recordings. Deep learning-based EEG denoising methods address these limitations effectively. First, they learn the nonlinear mapping between contaminated and clean EEG directly from data in an end-to-end manner. This approach does not rely on assumptions about spectral separability, thereby preserving neural activity more completely. Second, the reference information is incorporated during the training phase, allowing the trained model to perform artifact removal independently without external references. Third, deep learning models can be flexibly designed to accommodate various recording setups, achieving robust denoising for both high-density and single-channel EEG. Collectively, these advantages enable deep learning-based methods to overcome the main challenges of traditional approaches, providing more accurate and reliable EEG signal recovery. The superior denoising performance of deep learning-based EEG denoising methods has attracted increasing attention in EEG artifact removal research. As a result, many deep learning-based denoising methods have been developed and successfully applied in neural engineering areas. However, a systematic review of the techniques and applications in this field is still lacking. To address this gap, this paper reviews recent advances in deep learning-based EEG denoising from four perspectives: technical principle, benchmark dataset, denoising model, and evaluation method. Representative applications in neural signal analysis and BCI decoding are also summarized. Furthermore, the advantage, existing challenge, and future research direction of deep learning-based EEG denoising are discussed. This review aims to provide valuable theoretical insights and technical guidance for researchers. It is also expected to promote further advances and broader applications of deep learning-based EEG denoising techniques.
5.The Dual Role and Clinical Potential of Core Fucosylation in Liver Diseases
Zi-Han LEI ; Hui-Min XU ; De-Zhi ZHAO ; Yong-Hong GUO ; Hao-Qi DU
Progress in Biochemistry and Biophysics 2026;53(8):2161-2178
Core fucosylation, catalyzed exclusively by fucosyltransferase 8 (FUT8), is an evolutionarily conserved post-translational modification that has emerged as a central regulatory hub linking liver homeostasis, chronic disease progression, and malignant transformation. Liver diseases, particularly hepatocellular carcinoma, remain a leading global health burden characterized by late diagnosis, limited therapeutic options, and poor overall survival. While aberrant glycosylation is now recognized as a hallmark of cancer and inflammatory disorders, existing research on FUT8-mediated core fucosylation in liver diseases remains fragmented: the dynamic functional switch of FUT8 from a homeostatic regulator to a pathological driver across the full disease continuum has not been systematically delineated, and the integrated mechanisms by which core fucosylation modulates oncogenic signaling, metabolic reprogramming, and immune evasion remain poorly understood. This review synthesizes recent advances to establish a unified framework for understanding the dual role of core fucosylation in liver physiology and pathology, and evaluates its translational potential for precision medicine. At the molecular level, FUT8’s unique catalytic specificity makes core fucosylation an irreplaceable modification, as evidenced by the perinatal lethality and severe organ dysfunction in Fut8 knockout mice. In hepatocellular carcinoma, genomic amplification of guanosine 5'-diphosphate-fucose biosynthetic enzymes provides metabolic support for aberrant core fucosylation. FUT8 expression is tightly regulated by a multi-layered network: transcriptional activation via Wnt/β‑catenin and wild-type p53, epigenetic upregulation by lncRNAs, post-transcriptional repression by miR-122-5p and miR-34a, and virus-specific induction by hepatitis B virus/hepatitis C virus. Physiologically, core fucosylation maintains liver homeostasis through four core mechanisms: it acts as a molecular switch for epidermal growth factor receptor/hepatocyte growth factor receptor signaling to enable liver regeneration; directs polarized secretion of hepatocyte-derived glycoproteins into bile ducts; modulates cholesterol metabolism via the hepatocyte nuclear factor 1α-proprotein convertase subtilisin/kexin type 9-low density lipoprotein receptor axis; and regulates aging through insulin‑like growth factor 1 receptor signaling. Pathologically, core fucosylation exhibits context-dependent dual functions: in liver fibrosis, FUT8 upregulation in hepatic stellate cells forms a negative feedback loop that limits excessive fibrogenesis; in hepatocellular carcinoma, however, aberrant FUT8 overexpression drives cell-autonomous malignancy by constitutively activating epidermal growth factor/hepatocyte growth factor receptor, transforming growth factor‑β/Smad, and Wnt/β‑catenin pathways, while simultaneously establishing a multi-layered immune evasion network by stabilizing programmed cell death ligand 1 and cluster of differentiation 47, and impairing natural killer cell homeostasis via interleukin‑2 receptor β glycosylation. Clinically, stage-specific core fucosylation biomarkers enable non-invasive monitoring of liver disease progression: low molecular mass kringle-Fc fusion protein outperforms conventional markers for early fibrosis detection, while alpha-fetoprotein-L3 and novel glycopeptides (α‑2‑macroglobulin N‑linked glycosylation site 1424, lumican core fucosylated peptide) significantly improve early hepatocellular carcinoma diagnosis, especially in alpha-fetoprotein-negative patients. Next-generation detection technologies (chemoenzymatic labeling, site-specific mass spectrometry) overcome the specificity limitations of traditional lectin assays. Therapeutically, four promising strategies are emerging: small-molecule FUT8 inhibitors, afucosylated antibodies with enhanced antibody‑dependent cellular cytotoxicity, Fuc-modified targeted drug delivery systems, and core fucose-specific lectins for NASH treatment. The core challenge for clinical translation lies in FUT8’s inherent “double-edged sword” effect, as systemic inhibition disrupts its essential physiological functions beyond pathological roles. Long-term systemic FUT8 blockade not only impairs post-injury liver regeneration by abrogating epidermal growth factor/hepatocyte growth factor receptor signaling but also disrupts cholesterol homeostasis via the hepatocyte nuclear factor 1α-proprotein convertase subtilisin/kexin type 9-low density lipoprotein receptor axis, leading to dyslipidemia and altered bile secretion. Critically, it compromises immune surveillance by destabilizing interleukin‑2 receptor β on natural killer cells, reducing their cytotoxic activity against malignant and virally infected cells, and impairs IgG Fc-mediated effector functions, increasing susceptibility to infections. This fundamental trade-off between therapeutic efficacy and systemic toxicity necessitates a paradigm shift from non-specific global inhibition to precision modulation of pathological core fucosylation. By addressing these critical challenges, FUT8-mediated core fucosylation has the potential to transform liver disease management from late-stage intervention to early detection and precision therapy, ultimately improving patient outcomes and reducing the global burden of liver diseases.
6.The Dual Roles of ERK Signaling in Parkinson’s Disease: From Neurotoxicity to Neuroprotection
Chang-Zhi YANG ; Hui WANG ; Min YAN ; Shuai WEI ; Xue-Wen TIAN
Progress in Biochemistry and Biophysics 2026;53(9):2316-2333
Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta and abnormal accumulation of α‑synuclein. Its pathogenesis involves multiple interconnected processes, including oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, neuroinflammation, and impaired protein homeostasis. Extracellular signal-regulated kinase 1/2 (ERK1/2), a major component of the mitogen-activated protein kinase signaling network, plays an important role in neuronal survival, synaptic plasticity, stress responses, and cell death. However, accumulating evidence indicates that ERK signaling in PD is not unidirectional, as both insufficient activity and sustained overactivation have been associated with neuronal dysfunction and disease progression. In this review, we systematically summarize the evidence for the pathological and protective roles of ERK signaling in PD. Insufficient ERK activity may impair neurotrophic support, synaptic plasticity, mitochondrial homeostasis, and neuronal adaptation to stress, thereby increasing the vulnerability of dopaminergic neurons. In contrast, persistent and excessive ERK activation may promote neuroinflammation, oxidative stress, mitochondrial dysfunction, apoptosis, autophagy-lysosomal impairment, and abnormal α-synuclein accumulation. Conversely, moderate and transient ERK activation induced by neurotrophic factors, bioactive compounds, or exercise may enhance neuronal survival, antioxidant defense, synaptic plasticity, and functional recovery. These apparently contradictory findings suggest that ERK activation itself cannot be simply classified as either neuroprotective or neurotoxic. Based on the available evidence, we propose the concept of an “ERK activity window” to explain the context-dependent effects of ERK signaling in PD. This hypothesis suggests that ERK activity needs to remain within an appropriate dynamic range to maintain neuronal homeostasis and adaptive responses. ERK activity below this range may weaken neurotrophic support and stress resistance, whereas prolonged and high-intensity activation may exceed the adaptive capacity of neurons and glial cells, thereby promoting inflammatory and degenerative processes. Importantly, this functional window should not be regarded as a fixed threshold. Its biological effects are likely determined by the intensity and duration of activation, cell type, subcellular localization, upstream stimuli, interaction with other signaling pathways, and disease stage. This framework may therefore help reconcile the apparently inconsistent findings among different PD models and experimental conditions. From a therapeutic perspective, these findings indicate that ERK should not necessarily be considered a target for simple activation or inhibition. Instead, restoring ERK signaling toward an appropriate functional state may represent a more rational strategy. Exercise is of particular interest because it can simultaneously influence neurotrophic signaling, oxidative stress, inflammation, synaptic plasticity, and ERK activity, potentially promoting adaptive remodeling of ERK signaling according to pathological conditions. Nevertheless, current evidence is predominantly derived from cellular and animal studies, and the dynamic, cell-specific, and spatial characteristics of ERK signaling remain insufficiently defined. Blood-brain barrier penetration, long-term safety, preservation of physiological ERK functions, and the lack of reliable biomarkers for monitoring brain ERK activity also limit clinical translation. Importantly, the “ERK activity window” remains a theoretical framework, and direct clinical evidence that ERK modulation can alter the progression of human PD is currently lacking. Future studies should therefore integrate longitudinal analysis, cell-specific and spatial approaches, and clinical biomarker validation to determine whether precise regulation of ERK signaling can provide a viable strategy for disease-modifying intervention in PD.
7.Applications of Brain-heart Interaction in Consciousness State Assessment
Jun-Yi WANG ; Hai-Qing YU ; Qiang-Fan MENG ; Yong-Zhi HUANG ; Min-Peng XU ; Dong MING
Progress in Biochemistry and Biophysics 2026;53(10):2767-2785
Consciousness, which underpins human perception, cognition, and behavioural responses, has long been a major focus of neuroscience and medicine. Alterations in consciousness occur not only during reversible processes such as sleep and anaesthesia, but also in pathological conditions, including disorders of consciousness (DOC) and brain injury. With recent advances in the synchronized acquisition and analysis of multimodal physiological signals, such as electroencephalography (EEG) and electrocardiography (ECG), the dynamic interactions between the heart and brain have become increasingly apparent. A growing body of evidence indicates that heart-brain interactions are closely associated with the maintenance and transition of consciousness states, offering a novel perspective for elucidating their underlying mechanisms and supporting relevant clinical assessments. Current approaches to heart-brain interaction analysis for consciousness-state assessment can be broadly grouped into three categories: ECG-based methods, EEG-based methods, and heart-brain coupling analysis. These approaches characterize heart-brain interactions during changes in consciousness from the complementary perspectives of autonomic regulation, cortical interoceptive processing, and cross-system information transfer, respectively. Nevertheless, this field remains at an early stage. Most studies have focused on a single experimental context or a fixed analytical method, with insufficient systematic consideration of the applicability and limitations of different approaches. Moreover, the mechanisms underlying the emergence and alteration of consciousness remain incompletely understood. Accordingly, this review examines heart-brain interaction methods employed in recent consciousness-state assessment studies in accordance with progressively deeper analytical perspectives, and systematically evaluates the advantages and limitations of these methods across distinct consciousness-related conditions. Heart rate variability (HRV) is one of the classical ECG-based indices used to investigate heart-brain interactions. It refers to fluctuations in consecutive interbeat intervals over a specified time period and is regarded as a physiological measure of autonomic nervous system regulation that may indirectly reflect the strength of heart-brain interactions. Depending on the analytical dimension, HRV analysis is commonly divided into time-domain, frequency-domain, and complexity-index analyses. These approaches characterize autonomic activity in terms of temporal fluctuations, the distribution of frequency components, and nonlinear dynamical properties, respectively. Although extensive research supports their physiological interpretation, they cannot characterize directional interactions from the heart to the brain. Among EEG-based methods for heart-brain interaction analysis, EEG activity directly related to cardiac fluctuations has received particular attention. One of the most widely used measures is the heartbeat-evoked potential (HEP). HEP-based approaches are considered to directly reflect the capacity of the cerebral cortex to process cardiac afferent signals and may be especially advantageous for characterizing rapidly changing consciousness levels, such as those observed during sleep. However, they do not comprehensively capture dynamic bidirectional information exchange between the brain and heart and are susceptible to cardiac artefacts, respiration, and variation in preprocessing procedures. Heart-brain coupling analysis quantifies functional associations between ECG and EEG through cross-system interaction measures, thereby assessing dynamic interactions between the heart and brain. It emphasizes information transfer, feedback regulation, and cross-timescale coordination between the two systems, offering a more comprehensive perspective for investigating changes in consciousness during sleep, anaesthesia, and DOC. However, the neurophysiological mechanisms and physiological interpretation of individual computational indices have not yet been fully established, and the robustness of their results and their potential for clinical generalization require further validation. Finally, this review summarizes the commonalities and differences among the three classes of methods across research domains involving different consciousness states. It further argues that heart-brain interaction research requires deeper investigation at both the mechanistic level of consciousness and the level of clinical application. Current challenges and key issues are identified, and future directions and feasible pathways for heart-brain interaction research are discussed, with the aim of providing new perspectives for researchers in related fields.
8.Investigating the mechanism of Legionella pneumophila inhibiting endosome-lysosome fusion in mouse macrophages based on transcriptome sequencing
Min-Jia CHEN ; Xiu-Qin CAO ; Rui-Xia HE ; Hai-Xia CHEN ; Zhi-Wei YANG
Medical Journal of Chinese People's Liberation Army 2025;50(2):176-187
Objective To explore the pathogenic mechanisms of Legionella pneumophila(L.pneumophila)infection inhibiting the fusion of endosome-lysosome fusion in mouse macrophages.Methods Twelve C57 mice were randomly divided into control group and L.pneumophila infection group(n=6 each).After anesthesia,an equal volume of physiological saline or L.pneumophila solution was administered nasally.Body weight changes were monitored for 3 consecutive days,and the lungs were extracted to assess injury.Hematoxylin and eosin(HE)staining and immunohistochemical staining were performed to observe the pathological characteristics of lung tissue in both groups.Transcriptome sequencing was utilized to analyze differentially expressed genes(DEGs)and associated signaling pathways in lung tissues.Mouse bone marrow macrophages(BMDMs)were isolated and co-cultured with L.pneumophila,with infection status confirmed by immunofluorescence staining.Transcriptome sequencing was employed to analyze DEGs and enriched related signaling pathways before and after infection.Core genes involved in the post-infection signaling pathway were identified,and the consistency of their mRNA expression levels in vivo and in vitro was verified using RT-qPCR.The expression of relevant proteins was detected by Western Blotting,and bacterial proliferation assays were conducted to evaluate the intracellular replication of L.pneumophila.Results Compared with control group,the body weight of mice in L.pneumophila infection group significantly decreased(P<0.001)on the second and third day post-infection.Edema and red hepatoid degeneration were observed in both left and right lung tissues,with lesion areas spreading from the hilum to the lung periphery.HE staining revealed increased inflammatory cell infiltration in the alveolar spaces,thickening of alveolar septa and increased fibrin exudation in L.pneumophila infection group.Immunohistochemistry results showed a significant increase in myeloperoxidase(MPO)activity in the lung tissue infected mice(P<0.001).Transcriptome sequencing identified 2550 DEGs,with 1444 up-regulated genes and 1106 down-regulated genes.KEGG enrichment analysis indicated that these DEGs were mainly involved in pathways related to tumor necrosis factor,rheumatoid arthritis,Rap1,PI3K-Ak,and phagosome pathways.Immunofluorescence results showed in vitro proliferation of L.pneumophila within mouse BMDMs.Transcriptome sequencing identified 2550 DEGs,including 1677 up-regulated genes and 873 down-regulated genes.KEGG enrichment analysis showed that enrichment in pathway related to transcription dysregulation in cancer,PI3K-Akt and phagosome pathways.Thirteen core genes,including tubulin β1(Tubb1),were identified from the overlap between mouse lung tissue and BMDMs.RT-qPCR results demonstrated a significant decrease in Tubb1 expression in both lung tissue and BMDMs infected with L.pneumophila(P<0.001).Western Blotting results revealed significant decreases in Rab7,Tubb1,and LAMP2 protein expression(P<0.05),and increases in iNOS and MPO expression(P<0.05).Intracellular proliferation experiments indicated that L.pneumophila gradually increased within BMDMs over time.Conclusion The potential mechanism of L.pneumophila infection in mouse macrophages involves the down-regulation of Rab7/Tubb1/LAMP2 which inhibits the endosome-lysosome fusion.
9.Regulatory effect of neutrophils in microglial polarization after permanent ischemic stroke
Min-Hua HUANG ; Xin-Yan YE ; Si-Yu WU ; Shao-Tong LUO ; Zhi-Shan WU ; Yuan CHEN ; Su-Ning PING
Acta Anatomica Sinica 2025;56(2):136-142
Objective To investigate the effects of peripheral blood neutrophil infiltration on the polarization regulation of cerebral resident microglia under a permanent ischemic stroke model.Methods Fifty-eight C57BL/6 mice were divided into two groups.One group was sham group,and the other group of mice was subjected to permanent middle cerebral artery occlusion surgery.Mice were euthanized 48 hours,7 days,14 days,and 30 days after surgery for tissue collection.Western blotting was used to detect expression levels of M1 microglia markers CD 16,M2 microglia marker arginase 1(Arg1),inflammatory cytokine interleukin-1 β(IL-1β),and neutrophil marker myeloperoxidase(MPO)in brain tissue.Immunofluorescence histochemical staining was used to assess neutrophil infiltration and M2 microglial distribution around the infarct area in brain sections.In vitro,purified neutrophils were co-cultured with BV2 microglial cells.After lipopolysaccharide stimulation,the phagocytosis of neutrophils by BV2 cells was observed,and the expression levels of CD16 and Arg1 proteins in BV2 cells were detected.Results Western blotting showed that the levels of CD16(P<0.05),IL-1β(P<0.001),and MPO(P<0.05)in brain tissue increased significantly 48 hours and 7 days after surgery,then decreased,with MPO expression returning to normal levels 30 days after surgery.Immunofluorescence showed a significant increase of MPO-positive cells around the infarct area of the mouse cerebral cortex 48 hours after surgery(P<0.001),followed by a decrease(P<0.05).The number of ionized calcium binding adapter molecule 1(Iba1)and MPO double-positive cells gradually increased after surgery,and reached their peak at 14 days(P<0.05).Iba1 and Arg1 double-positive cells also increased significantly 7 days(P<0.05)and 14 days(P<0.01)after surgery.In vitro,co-culture experiments showed that after BV2 phagocytosing neutrophils,CD 16(P<0.05)significantly decreased and Arg1 significantly upregulated(P<0.05).Conclusion In a permanent ischemic stroke model,microglia transition from M1 to M2 type after phagocytosing neutrophils,and the injured brain area changes from pro-inflammatory state to anti-inflammatory state.
10.Molecular mechanism and therapeutic strategies of necrotic apoptosis in Alzheimer's disease
Zhi-Cheng LU ; Li-Na TANG ; Sheng-Long MO ; Cheng-Min YANG ; Chong-Dong JIAN ; Jing-Wei SHANG
Acta Anatomica Sinica 2025;56(2):239-247
This review delves into the pivotal role of necrotic apoptosis in Alzheimer's disease(AD),with a focus on treatment strategies,drug development,prospects,and challenges,highlighting its significance in the progression of the disease.Firstly,necrotic apoptosis plays a crucial role in the pathogenesis of AD,particularly in association with the abnormal metabolism of β-amyloid(Aβ)and Tau proteins.The primary focus of drug design is to regulate the metabolism pathways of these two proteins to slow down or inhibit the progression of necrotic apoptosis.Secondly,the progress in drug development further emphasizes the importance of necrotic apoptosis in treating AD.Current research mainly focuses on drugs that affect the metabolism of Aβ and Tau proteins,such as lecanemab.Still,inconsistent result underscore the necessity for a more comprehensive understanding of the molecular mechanisms of necrotic apoptosis.Finally,the prospects and challenges of necrotic apoptosis research in AD are thoroughly discussed.A deeper understanding of necrotic apoptosis contributes to a better comprehension of the pathological mechanisms of AD but also may reveal new therapeutic targets.However,challenges such as multifactorial influences and the selection of treatment timing necessitate further in-depth research in the future.In conclusion,this review advocates for future research to deepen the understanding of the molecular mechanisms of necrotic apoptosis,enhance research on treatment strategies,gain a deeper understanding of its cross-regulation with other cell death pathways,and promote collaboration between basic research and clinical practice to advance the comprehensive understanding and treatment of Alzheimer's disease and necrotic apoptosis.


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