Integrating Bulk RNA and Single-Cell Sequencing Data Unveils Efferocytosis Patterns and ceRNA Network in Ischemic Stroke.

Excessive inflammatory response following ischemic stroke (IS) injury is a key factor affecting the functional recovery of patients. The efferocytic clearance of apoptotic cells within ischemic brain tissue is a critical mechanism for mitigating inflammation, presenting a promising avenue for the treatment of ischemic stroke. However, the cellular and molecular mechanisms underlying efferocytosis in the brain after IS and its impact on brain injury and recovery are poorly understood. This study explored the roles of inflammation and efferocytosis in IS with bioinformatics. Three Gene Expression Omnibus Series (GSE) (GSE137482-3 m, GSE137482-18 m, and GSE30655) were obtained from NCBI (National Center for Biotechnology Information) and GEO (Gene Expression Omnibus). Differentially expressed genes (DEGs) were processed for GSEA (Gene Set Enrichment Analysis), GO (Gene Ontology Functional Enrichment Analysis), and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analyses. Efferocytosis-related genes were identified from the existing literature, following which the relationship between Differentially Expressed Genes (DEGs) and efferocytosis-related genes was examined. The single-cell dataset GSE174574 was employed to investigate the distinct expression profiles of efferocytosis-related genes. The identified hub genes were verified using the dataset of human brain and peripheral blood sample datasets GSE56267 and GSE122709. The dataset GSE215212 was used to predict competing endogenous RNA (ceRNA) network, and GSE231431 was applied to verify the expression of differential miRNAs. At last, the middle cerebral artery (MCAO) model was established to validate the efferocytosis process and the expression of hub genes. DEGs in two datasets were significantly enriched in pathways involved in inflammatory response and immunoregulation. Based on the least absolute shrinkage and selection operator (LASSO) analyses, we identified hub efferocytosis-related genes (Abca1, C1qc, Ptx3, Irf5, and Pros1) and key transcription factors (Stat5). The scRNA-seq analysis showed that these hub genes were mainly expressed in microglia and macrophages which are the main cells with efferocytosis function in the brain. We then identified miR-125b-5p as a therapeutic target of IS based on the ceRNA network. Finally, we validated the phagocytosis and clearance of dead cells by efferocytosis and the expression of hub gene Abca1 in MCAO mice models.

Dysfunctional regulatory T cell: May be an obstacle to immunotherapy in cardiovascular diseases.

Inflammatory responses are linked to cardiovascular diseases (CVDs) in various forms. Tregs, members of CD4+ T cells, play important roles in regulating immune system and suppressing inflammatory response, thus contributing to maintaining immune homeostasis. However, Tregs exert their powerful suppressive function relying on the stable phenotype and function. The stability of Tregs primarily depends on the FOXP3 (Forkhead box P3) expression and epigenetic regulation. Although Tregs are quite stable under physiological conditions, prolonged exposure to inflammatory cues, Tregs may lose suppressive function and require proinflammatory phenotype, namely plastic Tregs or ex-Tregs. There are extensive researches have established the beneficial role of Tregs in CVDs. Nevertheless, the potential risks of dysfunctional Tregs lack deep research. Anti-inflammatory and immunological modulation have been hotspots in the treatment of CVDs. Tregs are appealing because of their crucial role in resolving inflammation and promoting tissue repair. If alleviating inflammatory response through modulating Tregs could be a new therapeutic strategy for CVDs, the next step to consider is how to prevent the formation of dysfunctional Tregs or reverse detrimental Tregs to normal phenotype.

Efficient Photothermal Sensor Based on Coral-Like Hollow Gold Nanospheres for the Sensitive Detection of Sulfonamides.

Gold nanoparticles (AuNPs), universally regarded as colorimetric signal reporters, are widely employed in lateral flow immunoassays (LFIAs). However, it is difficult for AuNPs-LFIA to achieve a wide range and sensitive detection. Herein, novel coral-like hollow gold nanospheres (CHGNPs) are synthesized. The growth of gold nanospheres can be regulated to obtain a multibranched and hollow construction. The obtained CHGNPs possess intense broadband absorption across the visible to near-infrared region, exhibiting a high molar extinction coefficient of 14.65 × 1011 M-1 cm-1 and a photothermal conversion efficiency of 79.75%. Thus, the photothermal/colorimetric dual-readout LFIA is developed based on CHGNPs (CHGNPs-PT-LFIA and CHGNPs-CM-LFIA) to effectively improve the detection sensitivity and broaden the detection range in regard to sulfonamides (SAs). The limits of detection of the CHGNPs-PT-LFIA and CHGNPs-CM-LFIA reached 1.9 and 2.8 pg mL-1 for the quantitative detection of sulfaquinoxaline, respectively, which are 6.3-fold and 4.3-fold lower than that of the AuNPs-LFIA. Meanwhile, the CHGNPs-PT-LFIA broadened the detection range to three orders of magnitude, which ranged from 2.5 to 5000 pg mL-1 . The synthesized photothermal CHGNPs have been proven effective in improving the performance of the LFIA and provide a potential option for the construction of sensing platforms.

The role of TNC in atherosclerosis and drug development opportunities.

Tenascin C (TNC), a rich glycoprotein of the extracellular matrix, exhibits a pro-atherosclerosis or anti-atherosclerosis effect depending on its location. TNC, especially its C domain/isoform (TNC-C), is strongly overexpressed in atherosclerotic plaque active areas but virtually undetectable in most normal adult tissues, suggesting that TNC is a promising delivery vector target for atherosclerosis-targeted drugs. Many delivery vectors were investigated by recognizing TNC-C, including G11, G11-iRGD, TN11, PL1, and PL3. F16 and FNLM were also investigated by recognizing TNC-A1 and TNC, respectively. Notably, iRGD was undergoing clinical trials. PL1 not only recognizes TNC-C but also the extra domain-B (EDB) of fibronectin (FN), which is also a promising delivery vector for atherosclerosis-targeted drugs, and several conjugate agents are undergoing clinical trials. The F16-conjugate agent F16IL2 is undergoing clinical trials. Therefore, G11-iRGD, PL1, and F16 have great development value. Furthermore, ATN-RNA and IMA950 were investigated in clinical trials as therapeutic drugs and vaccines by targeting TNC, respectively. Therefore, targeting TNC could greatly improve the success rate of atherosclerosis-targeted drugs and/or specific drug development. This review discussed the role of TNC in atherosclerosis, atherosclerosis-targeted drug delivery vectors, and agent development to provide knowledge for drug development targeting TNC.

AAV1-hOTOF gene therapy for autosomal recessive deafness 9: a single-arm trial.

BACKGROUND: Autosomal recessive deafness 9, caused by mutations of the OTOF gene, is characterised by congenital or prelingual, severe-to-complete, bilateral hearing loss. However, no pharmacological treatment is currently available for congenital deafness. In this Article, we report the safety and efficacy of gene therapy with an adeno-associated virus (AAV) serotype 1 carrying a human OTOF transgene (AAV1-hOTOF) as a treatment for children with autosomal recessive deafness 9. METHODS: This single-arm, single-centre trial enrolled children (aged 1-18 years) with severe-to-complete hearing loss and confirmed mutations in both alleles of OTOF, and without bilateral cochlear implants. A single injection of AAV1-hOTOF was administered into the cochlea through the round window. The primary endpoint was dose-limiting toxicity at 6 weeks after injection. Auditory function and speech were assessed by appropriate auditory perception evaluation tools. All analyses were done according to the intention-to-treat principle. This trial is registered with Chinese Clinical Trial Registry, ChiCTR2200063181, and is ongoing. FINDINGS: Between Oct 19, 2022, and June 9, 2023, we screened 425 participants for eligibility and enrolled six children for AAV1-hOTOF gene therapy (one received a dose of 9 × 1011 vector genomes [vg] and five received 1·5 × 1012 vg). All participants completed follow-up visits up to week 26. No dose-limiting toxicity or serious adverse events occurred. In total, 48 adverse events were observed; 46 (96%) were grade 1-2 and two (4%) were grade 3 (decreased neutrophil count in one participant). Five children had hearing recovery, shown by a 40-57 dB reduction in the average auditory brainstem response (ABR) thresholds at 0·5-4·0 kHz. In the participant who received the 9 × 1011 vg dose, the average ABR threshold was improved from greater than 95 dB at baseline to 68 dB at 4 weeks, 53 dB at 13 weeks, and 45 dB at 26 weeks. In those who received 1·5 × 1012 AAV1-hOTOF, the average ABR thresholds changed from greater than 95 dB at baseline to 48 dB, 38 dB, 40 dB, and 55 dB in four children with hearing recovery at 26 weeks. Speech perception was improved in participants who had hearing recovery. INTERPRETATION: AAV1-hOTOF gene therapy is safe and efficacious as a novel treatment for children with autosomal recessive deafness 9. FUNDING: National Natural Science Foundation of China, National Key R&D Program of China, Science and Technology Commission of Shanghai Municipality, and Shanghai Refreshgene Therapeutics.

Sensitive fluorescence ELISA for the detection of zearalenone based on self-assembly DNA nanocomposites and copper nanoclusters.

Zearalenone (ZEN), produced by Fusarium species, is a potential risk to human health. Traditional enzyme-linked immunosorbent assay (ELISA) is restricted due to low sensitivity for the detection of ZEN. Herein, enzyme nanocomposites (ALP-SA-Bio-ssDNA, ASBD) were prepared with the self-assembly strategy based on streptavidin-labeled alkaline phosphatase (SA-ALP) and dual-biotinylated ssDNA (B2-ssDNA). The enzyme nanocomposites improved the loading amount of ALP and catalyzed more ascorbic acid 2-phosphate to generate ascorbic acid (AA). Subsequently, Cu2+ could be reduced to copper nanoclusters (CuNCs) having strong fluorescence signal by AA with poly T. Benefiting from the high enzyme load of nanocomposites and the strong signal of CuNCs, the fluorescence ELISA was successfully established for the detection of ZEN. The proposed method exhibited lower limit of detection (0.26 ng mL-1) than traditional ELISA (1.55 ng mL-1). The recovery rates ranged from 92.00% to 108.38% (coefficient of variation < 9.50%) for the detection of zearalenone in corn and wheat samples. In addition, the proposed method exhibited no cross reaction with four other mycotoxins. This proposed method could be used in trace detection for food safety.

Photoredox-Catalyzed Three-Component 1,2-Cyanoalkylpyridylation of Styrenes with Nonredox-Active Cyclic Oximes.

Three-component alkene 1,2-difunctionalizations have emerged as a powerful strategy for rapid buildup of diverse and complex alkylpyridines, but the distal functionalized alkyl radicals for the alkene 1,2-alkylpyridylations were still rare. Herein, we report an example of regioselective three-component 1,2-cyanoalkylpyridylation of feedstock styrenes with accessible nonredox-active cyclic oximes through visible-light photoredox catalysis, providing a series of structurally diverse ß-cyanoalkylated alkylpyridines. This protocol proceeds through a radical relay pathway including the generation of iminyl radicals enabled by phosphoranyl radical-mediated ß-scission, radical transposition through C-C bond cleavage, highly selective radical addition, and precise radical-radical cross-coupling sequence, thus facilitating the regioselective formation of two distinct C-C single bonds in a single-pot operation. This synthetic strategy features mild conditions, broad compatibility of functional groups and substrate scope, diverse product derivatization, and late-stage modification.

Integrated Assessment of the Leading Paths to Mitigate CO2 Emissions from the Organic Chemical and Plastics Industry.

The chemical industry is a major and growing source of CO2 emissions. Here, we extend the principal U.S.-based integrated assessment model, GCAM, to include a representation of steam cracking, the dominant process in the organic chemical industry today, and a suite of emerging decarbonization strategies, including catalytic cracking, lower-carbon process heat, and feedstock switching. We find that emerging catalytic production technologies only have a small impact on midcentury emissions mitigation. In contrast, process heat generation could achieve strong mitigation, reducing associated CO2 emissions by ∼76% by 2050. Process heat generation is diversified to include carbon capture and storage (CCS), hydrogen, and electrification. A sensitivity analysis reveals that our results for future net CO2 emissions are most sensitive to the amount of CCS deployed globally. The system as defined cannot reach net-zero emissions if the share of incineration increases as projected without coupling incineration with CCS. Less organic chemicals are produced in a net-zero CO2 future than those in a no-policy scenario. Mitigation of feedstock emissions relies heavily on biogenic carbon used as an alternative feedstock and waste treatment of plastics. The only scenario that delivers net-negative CO2 emissions from the organic chemical sector (by 2070) combines greater use of biogenic feedstocks with a continued reliance on landfilling of waste plastic, versus recycling or incineration, which has trade-offs.

Toxic Elements in Beans from Zhejiang, Southeast China: Distribution and Probabilistic Health Risk Assessment.

This study described the distribution of As, Cd, Cr, Hg, and Pb in 692 bean samples from Zhejiang province, southeast China, and estimated the health risk using Monte Carlo simulation. The average levels of As, Cd, Cr, Hg, and Pb were 0.0349, 0.0379, 0.246, 0.0019, and 0.0246 mg kg-1. Correlation analyses showed very strong positive correlations for Cd-Pb in kidney beans and mung beans, Cd-As in black beans, and Pb-As in red beans. The target hazard quotients (THQs) were adopted for non-carcinogenic risk assessment, and THQs at the 50th percentile were all less than 1, indicating that there are no deleterious effects from rice exposure to these elements. When evaluating THQ for multiple elements, the certainty with a hazard index (HI) greater than 1 for children was 12.64%, for teens 11.54%, and for adults 1.01%. The sensitivity analysis reveals that the concentration of Cd in beans and ED (exposure duration) are the main principal factors that contributed to the total risk. The mean carcinogenic risks for children, teens, and adults were all less than 1 × 10-4, indicating no potential carcinogenic risk. Despite that, the routine monitoring of these elements, especially for Cd should be continued.

Complementary Homogeneous Electrochemical and Photothermal Dual-Modal Sensor for Highly Sensitive Detection of Organophosphorus Pesticides via Stimuli-Responsive COF/Methylene Blue@MnO2 Composite.

Credible and on-site detection of organophosphorus pesticides (OPs) in complex matrixes is significant for food security and environmental monitoring. Herein, a novel COF/methylene blue@MnO2 (COF/MB@MnO2) composite featured abundant signal loading, a specific recognition unit, and robust oxidase-like activity was successfully prepared through facile assembly processes. The multifunctional composite acted as a homogeneous electrochemical and photothermal dual-mode sensing platform for OPs detection through stimuli-responsive regulation. Without the presence of OPs, the surface MnO2 coating could recognize thiocholine (TCh), originating from acetylcholinesterase (AChE)-catalyzed hydrolysis of acetylthiocholine (ATCh), and exhibited a distinctly amplified diffusion current due to the release of plentiful MB; while the residual MnO2 nanosheets could only catalyze less TMB into oxidized TMB (oxTMB) with a typical near-infrared (NIR) absorption, enabling NIR-driven photothermal assay with a low temperature using a portable thermometer. Based on the inhibitory effect of OPs on AChE activity and OP-regulated generation of TCh, chlorpyrifos as a model target can be accurately detected with a low limit of detection of 0.0632 and 0.108 ng/mL by complementary electrochemical and photothermal measurements, respectively. The present dual-mode sensor was demonstrated to be excellent for application to the reliable detection of OPs in complex environmental and food samples. This work can not only provide a complementary dual-mode method for convenient and on-site detection of OPs in different scenarios but also expand the application scope of the COF-based multifunctional composite in multimodal sensors.

Molecular characterization and prognosis of mutant TP53 acute myeloid leukemia and myelodysplastic syndrome with excess blasts.

INTRODUCTION: Myeloid tumors typically harbor TP53 mutations, which are linked to a dismal prognosis. There are fewer studies on whether TP53-mutated acute myeloid leukemia (AML) and myelodysplastic syndrome with excess blasts (MDS-EB) differ in molecular characteristics and should be considered as separate entities. METHODS: Between January 2016 and December 2021, a retrospective analysis was done on a total of 73 newly diagnosed AML patients and 61 MDS-EB patients from the first affiliated hospital of Soochow University. We described a survival profile and a thorough characterization of newly found TP53-mutant AML and MDS-EB and investigated the relationship between these characteristics and overall survival (OS). RESULTS: 38 (31.1%) were mono-allelic, and 84 (68.9%) were bi-allelic. There is no significant difference between TP53-mutated AML and MDS-EB (median OS 12.9 verse 14.4 months; p = .558). Better overall survival was linked to mono-allelic TP53 than bi-allelic TP53(HR = 3.030, CI:1.714-5.354, p < .001). However, the number of TP53 mutations and comutations were not significantly associated with OS. TP53 variant allele frequency cutoff of 50% is significant correlation with OS (HR: 2.177, 95% CI: 1.142-4.148; p = .0063). CONCLUSION: Our data revealed that allele status and allogeneic hematopoietic stem cell transplant independently affect the prognostic of AML and MDS-EB patients, with a concordance of molecular features and survival between these two disease entities. Our analysis favors considering TP53-mutated AML/MDS-EB as a distinct disorder.

Further delineation of EBF3-related syndromic neurodevelopmental disorder in twelve Chinese patients.

Neurodevelopmental disorders (NDDs) have heterogeneity in both clinical characteristics and genetic factors. EBF3 is a recently discovered gene associated with a syndromic form of NDDs characterized by hypotonia, ataxia and facial features. In this study, we report twelve unrelated individuals with EBF3 variants using next-generation sequencing. Five missense variants (four novel variants and one known variant) and seven copy number variations (CNVs) of EBF3 gene were identified. All of these patients exhibited developmental delay/intellectual disability. Ataxia was observed in 33% (6/9) of the patients, and abnormal muscle tone was observed in 55% (6/11) of the patients. Aberrant MRI reports were noted in 64% (7/11) of the patients. Four novel missense variants were all located in the DNA-binding domain. The pathogenicity of these variants was validated by in vitro experiments. We found that the subcellular protein localization of the R152C and F211L mutants was changed, and the distribution pattern of the R163G mutant was changed from even to granular. Luciferase assay results showed that the four EBF3 mutants' transcriptional activities were all significantly decreased (p < 0.01). Our study further expanded the gene mutation spectrum of EBF3-related NDD.

Construction and Evaluation of Zeolitic Imidazolate Framework-Encapsulated Hemoglobin Microparticles as Oxygen Carriers.

Artificial oxygen carriers, such as favorably hemoglobin-based oxygen carriers, have received considerable attention due to some drawbacks of human donor blood. Among all oxygen carriers, the metal organic framework (MOF) exhibits excellent oxygen-carrying capacity due to its good encapsulation efficiency and competitive biocompatibility. Recently, zeolitic imidazolate frameworks (ZIFs) with unique structure have attracted much attention due to their outstanding solvothermal stability. Notably, ZIF-8, the prototypical ZIF, has been utilized to load hemoglobin (Hb) as a potential blood substitute. In this work, another ZIF material, which possesses a high oxygen binding/release capability, suitable safety profile, high stability, and efficiency as a potential oxygen carrier, was used to encapsulate Hb in an environment-friendly condition.

A separable nanodevice enables multilayer imaging of diverse biomarkers for precise diagnosis.

An acid-driven separable nanodevice was designed for multilayer imaging of diverse biomarkers with different spatial distributions in living cells. The proposed nanodevice can simultaneously perform in situ imaging of the intracellular microRNAs and extracellular pH, affording a new approach to develop a precise imaging system for disease diagnosis.

A self-circulating electro-fenton-like process over Fe3O4-CaO2 cathode for highly efficient degradation of levofloxacin.

Electro-Fenton reaction was limited by the generation of H2O2 and the circulation of Fe(Ⅱ)/Fe(Ⅲ). Herein, an efficient electro-Fenton-like process was constructed based on Fe3O4-CaO2 cathode promoted by peroxymonosulfate (PMS). Levofloxacin (LEV) could be efficiently degraded (92.1%) and mineralized with the TOC removal of 74.5% in this self-circulating process. More importantly, the Fe3O4-CaO2 exhibited good stability in the recycles due that CaO2 was covered by Fe3O4, which inhibited the rapid release of H2O2. Mechanism analysis indicated that CaO2 could not only replace H2O2 to accelerate the oxidation of Fe(Ⅱ) to Fe(Ⅲ), but also could form complexes with Fe(Ⅲ) and PMS to transfer electrons from ligands to metals, thereby enhancing the reduction of Fe(Ⅲ) to Fe(Ⅱ). As a result, the electrical consumption was significantly reduced, which was only 5.0% of the Fe3O4 in electro-Fenton reaction. Meanwhile, the hydrolyzed product of Ca(OH)2 reacted with Fe(Ⅲ) in the presence of H2O2 and converted into CaO2. Thus, the self-circulation of CaO2/Ca(OH)2 and Fe(Ⅲ)/Fe(Ⅱ) was realized, which accelerated the generation of active species, such as, ·OH, O2·- and 1O2. This work first proposed a self-circulating electro-Fenton-like system and demonstrated the potential application of Fe3O4-CaO2 in the treatment of wastewater.

Risk assessment of 3-monochloropropane-1,2-diol esters through dietary exposure from edible oils for the Zhejiang population in China by Monte Carlo simulation.

The purpose of this study was to assess the risk of 3-monochoropropane-1,2-diol (3-MCPD) esters from edible oils for the Zhejiang population in China. Exposure assessment of 3-MCPD esters was evaluated by Monte Carlo simulation based on the concentrations of 3-MCPD esters in edible oils combined with survey data on the eating habits of Chinese residents classified by age group and gender. The simulation results indicated that the mean daily intakes (CDI) of 3-MCPD esters for children 7-10 years old were 2.154 µg (kg BW d)-1 for boys and 2.049 µg (kg BW d)-1 for girls, which are lower than the provisional maximum tolerable daily intake (PMTDI) of 4 µg (kg BW d)-1 for 3-MCPD and 3-MCPD esters individually or in combination, set by the Joint FAO/WHO Expert Committee on Food Additives. The range of mean dietary intakes of 3-MCPD esters in different subpopulation groups ranged 1.242-1.672 µg (kg BW d)-1, which was lower than the PMTDI. However, the CDI values of 3-MCPD esters in high percentile exposure subgroups (95th, 99th) of males (7-49 years old) and females (7-10 and 50-75 years old) were all above 4µg (kg bw d)-1. Outside of the senior group (50-75 years old), males had more exposure to 3-MCPD than females. The average hazard indexes (HI) of 3-MCPD esters to male and female children were 1.257 and 1.024, respectively, indicating there was a risk, but no immediate measures are required to address this risk. The average HI of 3-MCPD esters to adolescent, adult, and seniors were all below 1, indicating risk for those age groups were at an acceptable level.

In the developing cerebral cortex: axonogenesis, synapse formation, and synaptic plasticity are regulated by SATB2 target genes.

BACKGROUND: Special AT-rich sequence-binding protein 2 is essential for the development of cerebral cortex and key molecular node for the establishment of proper neural circuitry and function. Mutations in the SATB2 gene lead to SATB2-associated syndrome, which is characterized by abnormal development of skeleton and central nervous systems. METHODS: We generated Satb2 knockout mouse model through CRISPR-Cas9 technology and performed RNA-seq and ChIP-seq of embryonic cerebral cortex. We conducted RT-qPCR, western blot, immunofluorescence staining, luciferase reporter assay and behavioral analysis for experimental verification. RESULTS: We identified 1363 downstream effector genes of Satb2 and correlation analysis of Satb2-targeted genes and neurological disease genes showed that Satb2 contribute to cognitive and mental disorders from the early developmental stage. We found that Satb2 directly regulate the expression of Ntng1, Cdh13, Kitl, genes important for axon guidance, synaptic formation, neuron migration, and Satb2 directly activates the expression of Mef2c. We also showed that Satb2 heterozygous knockout mice showed impaired spatial learning and memory. CONCLUSIONS: Taken together, our study supportsroles of Satb2 in the regulation of axonogenesis and synaptic formation at the early developmental stage and provides new insights into the complicated regulatory mechanism of Satb2 and new evidence to elucidate the pathogen of SATB2-associated syndrome. IMPACT: 1363 downstream effector genes of Satb2 were classified into 5 clusters with different temporal expression patterns. We identified Plxnd1, Ntng1, Efnb2, Ephb1, Plxna2, Epha3, Plxna4, Unc5c, and Flrt2 as axon guidance molecules to regulate axonogenesis. 168 targeted genes of Satb2 were found to regulate synaptic formation in the early development of the cerebral cortex. Transcription factor Mef2c is positively regulated by Satb2, and 28 Mef2c-targeted genes can be directly regulated by Satb2. In the Morris water maze test, Satb2+/- mice showed impaired spatial learning and memory, further strengthening that Satb2 can regulate synaptic functions.

Determination of tetrodotoxin in salted pufferfish by liquid chromatography-tandem mass spectrometry / 预防医学

Objective@#To develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with cation exchange-based solid phase extraction (SPE) for determination of tetrodotoxin (TTX) in salted pufferfish. @*Methods@#Evenly crushed salted pufferfish samples were subjected to ultrasound-assisted extraction with 0.5% acetic acid/50% methanol/water. The extract was cleaned with cation exchange-based SPE cartridge and eluted with 0.3% hydrochloric acid and 50% acetonitrile/water. The eluent was neutralized with ammonia and separated with a Waters XBridgeTM BEH Amide column (150 mm×3.0 mm, 1.7 μm), and determined using LC-MS/MS in a multiple reaction monitoring mode.@*Results@#The matrix effects of TTX were 85.7%-92.4%, and the matrix suppression effect was under effective control following clean-up procedures using the optimized SPE method. The TTX showed a good linear relationship at the range of 2.0 to 4 000 μg/kg, with a correlation coefficient (r2) of 0.999 2. The limits of detection and quantitation for TTX in sample matrix were 1.0 μg/kg and 2.0 μg/kg, respectively. The mean spiked-recovery rates were 81.2% to 96.5% at spiked amounts of 2.0, 200 μg/kg and 2 200 μg/kg, with relative standard deviations (RSDs) of 4.3% to 7.5%. The intraday accuracy and precision of TTX were 84.4% to 95.6% and 4.9% to 5.8% in quality control samples, and the interday accuracy and precision of TTX were 86.1% to 94.9% and 5.5% to 8.5% in quality control samples. The detection of TTX was 60.5% in 38 market-sold salted pufferfish products using the established LC-MS/MS method.@*Conclusion@#The established LC-MS/MS method is effective for accurate quantitative determination of TTX in salted pufferfish.