Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Background: and Purpose Live cell-based assays (LCBA) are increasingly used for serological antibody detection due to their ability to preserve antigen conformation, offering moderately higher sensitivity than fixed cell-based assays. However, the clinical necessity of prioritizing LCBA for the detection of aquaporin-4 immunoglobulin G (AQP4-IgG) in neuromyelitis optica spectrum disorder (NMOSD) remains unclear, especially when compared to its established role in diagnosing myelin oligodendrocyte glycoprotein antibody-associated disease. Methods: We compared the performance of live cell-based assays using immunofluorescence (LCBA-IF) and fixed cell-based assays using immunofluorescence (FCBA-IF) in detecting AQP4-IgG in 90 cases of NMOSD meeting 2015 International Panel for Neuromyelitis Optica Diagnosis criteria, alongside 40 controls. Additionally, we further investigated the relationship between AQP4-IgG titers as measured by LCBA-IF and FCBA-IF and clinical parameters in NMOSD patients. Results: Results showed 96.9% agreement between LCBA-IF and FCBA-IF (Cohen’s κ=0.935), with a strong Spearman correlation (0.977, p<0.001). Both methods demonstrated 100% specificity, with LCBA-IF showing slightly higher sensitivity compared to FCBA-IF. Within LCBAIF-tested groups, statistically significant differences in annualized relapse rates were observed across all pairwise comparisons (low-titer vs. moderate-titer, low-titer vs. high-titer, and moderate-titer vs. high-titer; all p<0.050). However, this association reached statistical significance in some FCBA-IF-tested groups. Conclusions Overall, there is a strong concordance between LCBA-IF and FCBA-IF in detecting AQP4-IgG, where LCBA-IF shows slightly higher sensitivity. Furthermore, there is a potential link between elevated AQP4-IgG titers and an increased risk of relapse, and this correlation may appear more pronounced when using LCBA-IF.

Objective To establish a chromatography-tandem mass spectrometry method for detecting chlorfenapyr and its metabolite tralopyril in blood,and to investigate the toxicokinetics in rats.Methods Chlorfenapyr(8 mg/kg)was administered orally to rats,and blood samples were collected from rats'canthus vein at 5 min,15 min,30 min,1 h,3 h,6 h,12 h,24 h and 48 h after administration.The blood samples were extracted using 100 μL of 5%formic acid solution and 400 μL of acetonitrile.Chlorfena-pyr was qualitatively and quantitatively detected by triple quadrupole gas chromatography-tandem mass spectrometry(GC-MS/MS)and tralopyril was detected by triple quadrupole liquid chromatography-tandem mass spectrometry(LC-MS/MS).The DAS 3.0 software was used to fit the toxicokinetic equa-tions and calculate the toxicokinetic parameters.Results Chlorfenapyr was detectable from 5 min to 24 h with a peak time of 1 h.Tralopyril was detectable from 15 min to 48 h with a peak time of 3 h.The toxicokinetic process of chlorfenapyr in rat blood conformed to a first-order absorption one-compartment open model,with the toxicokinetic equation described as C=e-0.265t-e-0.175t.Tralopyril con-formed to the first-order absorption three-compartment model,and the toxicokinetic equation was C=47 361.069e-2.209t-35 404.962e-1.486t+11 956.363e-0.512t.In the equations,C stands for the concentration of the target substance in the blood,e is the natural constant(≈2.718 28),and t stands for time.Conclu-sion This study optimized the detection method for chlorfenapyr and its metabolite tralopyril in blood.The toxicokinetic equations and parameters of chlorfenapyr and tralopyril can provide a reference for the estimation of oral intake time of chlorfenapyr.

Objective To explore the relevant factors affecting the efficacy of traditional Chinese medicine in treating MG,and to develop and validate a nomogram model,in order to personalize the prediction of the probability of benefits for MG patients after traditional Chinese medicine treatment,further guide clinical physicians in targeted medication,and provide guidance for the traditional Chinese medicine treatment of MG.Method Retrospective analysis of MG patients who visited the Affiliated Hospital of Changchun University of Traditional Chinese Medicine from March 2018 to June 2022,13 clinical factors were selected to evaluate the results.To acquire independent factors,univariate and multivariate Logistic analyses were performed.The area under the receiver operating characteristic curve,Harrell's concordance index,calibration curve,and decision curve analyses were used to evaluate the predictive ability,accuracy,and clinical practicability of the prediction model.Results A total of 204 cases were included,divided into derivation cohort 139 cases and temporal validation cohort 65 cases.Multivariate Logistic regression showed 4 independent predictors affecting effectiveness of traditional Chinese medicine in treating MG,including age at onset,repetitive nerve stimulation positive,oral immunosuppressant and anxiety/depression.AUC values for the model group and validation group were 0.76(95%CI:0.68-0.84)and 0.83(95%CI:0.71-0.95),respectively,and based on calibration curve and decision curve analysis,we concluded that the nomogram showed excellent performance.Conclusion MG patients may experience a decrease in short-term efficacy with age,positive RNS,concomitant emotional abnormalities,or recent history of immunosuppressive therapy.This nomogram effectively predicts the possibility of short-term effective traditional Chinese medicine treatment in MG patients.

Metastatic dissemination is the major cause of death from breast-cancer (BC). Fusobacterium nucleatum (F.n) is widely enriched in BC and has recently been identified as one of the high-risk factors for promoting BC metastasis. Here, with an experimental model, we demonstrated that intratumoral F.n induced BC aggressiveness by transcriptionally activating Epithelial-mesenchymal transition-associated genes. Therefore, the F.n may be a potential target to prevent metastasis. Given the fact that cancer-associated fibroblasts (CAFs) are abundant in BC and located near blood vessels, we report an optogenetic system that drives CAF to in situ produce human antibacterial peptide LL37, with the characteristics of biosafety and freely intercellular trafficking, for depleting intratumoral F.n, leading to a 72.1% reduction in lung metastatic nodules number without affecting the balance of the systemic flora. Notably, mild photothermal treatment was found that could normalize CAF, contributing to synergistically inhibiting BC metastasis. In addition, the system can also simultaneously encode a gene of TNF-related apoptosis-inducing ligand to suppress the primary tumor. Together, our study highlights the potential of local elimination of tumor pathogenic bacteria to prevent BC metastasis.

AIM:To investigate the effects of the neutrophil elastase(NE)inhibitor sivelestat on the pathologi-cal changes of cardiac tissues in mice with heart failure with preserved ejection fraction(HFpEF).METHODS:Eight-week-old C57BL/6J mice were randomly divided into 3 groups:control group(n=5),model group(n=6),and treatment group(n=18).The HFpEF mouse model was established using a combined approach of high-fat diet and NG-nitro-L-argi-nine methyl ester(L-NAME).The mice in treatment group received intraperitoneal injection of sivelestat at doses of 12.5,25 and 50 mg·kg-1·d-1(n=6),while those in control and model groups were injected with the same volume of nor-mal saline.After 12 weeks,small animal ultrasound was employed to assess changes in cardiac function,and the lung weight-to-tibia length(LW/TL)ratio was calculated to evaluate pulmonary edema.An exercise fatigue test was conducted to assess exercise intolerance.Histological evaluations were performed using HE,wheat germ agglutinin,dihydroethidium and Sirius red staining to examine overall heart morphology,cross-sectional area of cardiomyocytes,levels of oxidative stress,and the extent of cardiac fibrosis.The expression of fibrosis-related proteins was analyzed using Western blot.RE-SULTS:Compared with model group,sivelestat at various concentrations significantly improved cardiac diastolic function in HFpEF mice,indicated by an increased E/A ratio and a decreased E/e'ratio(P＜0.05).The LW/TL ratio decreased,alleviating lung congestion and exercise intolerance(P＜0.05).The heart weight-to-tibia length(HW/TL)ratio,overall heart cross-sectional area,and cardiomyocyte cross-sectional area all decreased,indicating attenuation in cardiac hypertro-phy(P＜0.05).Additionally,cardiac fibrosis and reactive oxygen species levels were significantly reduced(P＜0.05).CONCLUSION:Inhibition of NE exerts a protective effect against diastolic dysfunction and cardiac fibrosis induced by HFpEF in mice.

Objective:To apply combined serological diagnostic methods for anti-BP180-type and anti-laminin 332 (Ln332) -type mucous membrane pemphigoid (MMP), and to summarize their clinical and immunoserological characteristics.Methods:A retrospective analysis was conducted on the data from 52 patients clinically suspected of having MMP at the Hospital of Dermatology, Chinese Academy of Medical Sciences from January 2017 to February 2022. Serum samples were collected, and combined serological tests, including indirect immunofluorescence on salt-split skin, enzyme-linked immunosorbent assay, and immunoblotting, were performed to analyze the immunoserological and clinical characteristics of the patients. The Fisher′s exact test was used to compare the lesion occurrence rates between groups.Results:Among the 52 patients clinically suspected of MMP, 32 (61.5%) were diagnosed with anti-BP180-type MMP, 10 (19.2%) with anti-Ln332-type MMP, and 4 (7.7%) with anti-BP180- and anti-Ln332-type MMP due to the presence of both anti-BP180 and anti-Ln332 antibodies; 2 tested positive for IgG on the epidermal side of salt-split skin, but no target antigens were identified by serological tests, and they were diagnosed with MMP (subtype pending) ; 4 tested negative by immunoserological tests. Ocular involvement was observed in 6 out of 10 patients with anti-Ln332-type MMP, whereas only 6 out of 32 anti-BP180-type MMP patients (18.8%) had ocular symptoms, and there was a significant difference in the occurrence rate of ocular involvement between the two groups ( P = 0.02) ; the occurrence rates of nasal involvement and multi-mucosal involvement were significantly higher in the anti-Ln332-type MMP patients (50%[5/10], 90%[9/10], respectively) than in the anti-BP180-type MMP patients (0, 25%[8/32], respectively, both P < 0.001). Scar formation occurred in 6 out of 10 anti-Ln332-type MMP patients, but occurred in only 6 out of 32 anti-BP180-type patients (18.8%, P = 0.02) . Conclusion:The combination of indirect immunofluorescence on salt-split skin, enzyme-linked immunosorbent assay, and immunoblotting could effectively identify anti-BP180 and anti-Ln332 autoantibodies in MMP patients, with BP180 being the most common target antigen; compared with anti-BP180-type MMP, anti-Ln332-type MMP appeared to be more frequently involve the ocular and nasal mucosae, associated with the involvement of multiple mucosal sites, carrying a higher risk of scar formation.

Objective:To evaluate the efficacy and safety of rivaroxaban and investigate the clinical features of Mycoplasma pneumoniae pneumonia (MPP) associated with pulmonary thromboembolism (PTE) in children. Methods:A case series study was conducted on 36 children, diagnosed with MPP associated with PTE and hospitalized in our institution from January 2020 to June 2024 of Department of Pediatric Respiratory, Shandong Provincial Hospital Affiliated to Shandong First Medical University. Clinical data and follow-up information were collected to analyze their clinical characteristics, outcomes, and adverse events to rivaroxaban. Comparison of coagulation indices before and after treatment with rivaroxaban using the Mann-Whitney rank sum test.Results:Among the 36 children, there were 27 males and 9 females, and the age of onset was (7.8±2.8) years. PTE was diagnosed (17±6) days after the onset of MPP. Thirty-four cases (94%) were classified as low-risk PTE, and 13 cases (36%) had thromboembolism of multiple anatomic sites. All patients presented with cough and fever, manifesting as shortness of breath in 33 cases (92%), chest pain in 12 case (33%), hemoptysis in 6 case (17%) and dyspnea in 5 cases (14%). Pulmonary artery involvement was demonstrated by CT pulmonary angiography in all 36 children. The D-dimer level was 5.1 (4.2, 12.2) mg/L. D-dimer levels were 5.1 (4.2, 12.2) mg/L, of which 29 cases (81%) were ≥4.0 mg/L. The total duration of anticoagulation 3.1 (2.5, 4.2) months. All children received rivaroxaban for 2.7 (2.2, 3.8) months. Of the 36 children, 35 cases were followed up after 3 months of anticoagulant therapy, and 30 cases (83%) showed pulmonary artery thrombus absorption. Finally, follow-up outcome data were available for 34 cases, of which 33 showed complete resolution of thrombus in the affected areas, and 1 showed partial resolution. There were no cases of death, thrombus recurrence or progression, major bleeding events occurred or chronic thromboembolic pulmonary hypertension. Adverse events included hemoptysis in 2 cases and elevated liver enzymes in 4 cases. After the treatment of rivaroxaban, the levels of D-dimer were decreased compared with those before the treatment of PTE (0.3 (0.2, 0.5) vs. 5.1 (4.2, 12.2) mg/L, Z=-7.12, P<0.05), and the levels of prothrombin time levels were significantly longer compared with those before the treatment of PTE (3.6 (12.4, 14.9) vs. 13.0 (11.8, 13.6) s, Z=2.34, P<0.05). Conclusions:During the course of MPP, the emergence of clinical symptoms such as short of breath, chest pain, hemoptysis, dyspnea or along with elevated D-dimer levels, should raise suspicion for the occurrence of PTE. Rivaroxaban has shown good efficacy and a favorable safety profile.

Objective:To investigate the clinical manifestations, therapeutic strategies and prognostic outcomes in pediatric patients with severe Mycoplasma pneumoniae pneumonia (SMPP) complicated by cardiac thrombosis. Methods:This case series study retrospectively analyzed 15 pediatric patients with SMPP complicated by cardiac thrombosis. The patients was recruited from the Department of Pediatric Respiratory Medicine at Shandong Provincial Hospital Affiliated to Shandong First Medical University between July 2018 and January 2025. Comprehensive clinical data and follow-up information were collected.Results:Among the 15 children, 10 were male and 5 were female, and the age of onset was 8.0 (6.3, 10.0) years. All 15 children presented with fever and cough, while additional symptoms included dyspnea in 7 cases, chest pain in 6 cases, hemoptysis in 3 cases, and chest tightness in 1 case. The white blood cell count was 11.7 (9.5, 15.9)×10 9/L, C-reactive protein was 31.6 (17.5, 64.8) mg/L and lactate dehydrogenase was 548.2 (410.4, 768.3) U/L. A total of 14 children underwent testing for the Mycoplasma pneumoniae drug resistance genes 2063A>G and 2064A>G, of which 13 tested positive. The plasma D-dimer levels of 15 children were 8.77 (7.23, 12.50) mg/L, all of which were higher than normal. Among the 15 children, 5 had decreased activity of anticoagulant proteins (protein C, protein S, antithrombin Ⅲ), and 8 tested positive for antiphospholipid antibodies. Chest CT scans of all 15 children showed pulmonary consolidation and (or) atelectasis, with pleural effusion present in 12 cases. In the 15 children, thrombosis was detected at 14.0 (11.0, 18.0) days after the onset of illness. The locations of cardiac thrombosis included the right ventricle in 9 cases, the right atrium in 5 cases, and the left atrium in 1 case. Additionally, 10 cases had pulmonary vascular embolism, comprising 9 cases of pulmonary artery thrombosis and 1 case of pulmonary vein thrombosis. After anticoagulant treatment, cardiac thrombi disappeared in 10 children. Five children who did not show improvement with anticoagulation underwent surgical thrombectomy. In the follow-up of 15 children, lung imaging basically returned to normal, with no major hemorrhagic events or other adverse events. Conclusions:In children with Mycoplasma pneumoniae pneumonia, the presence of clinical symptoms such as shortness of breath, chest pain and hemoptysis, along with elevated plasma D-dimer levels, should raise suspicion for the possibility of cardiac thrombosis. SMPP complicated by cardiac thrombosis, prognosis is good following anticoagulation or surgical treatment.