1.The Diversity of Filamentous Morphologies and Magnetic Sensitivity Modulated by Diverse MagR Expression in Bacteria
Ya-Fei CHANG ; Jing ZHANG ; Peng ZHANG ; Xiu-Juan ZHOU ; Meng-Ke WEI ; Tian-Tian CAI ; Pei-Qi HE ; Jun-Feng WANG ; Can XIE
Progress in Biochemistry and Biophysics 2026;53(5):1439-1456
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.
2.The Diversity of Filamentous Morphologies and Magnetic Sensitivity Modulated by Diverse MagR Expression in Bacteria
Ya-Fei CHANG ; Jing ZHANG ; Peng ZHANG ; Xiu-Juan ZHOU ; Meng-Ke WEI ; Tian-Tian CAI ; Pei-Qi HE ; Jun-Feng WANG ; Can XIE
Progress in Biochemistry and Biophysics 2026;53(5):1439-1456
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.
3.Exploring behavioral patterns and hippocampal neurogenesis in autism spectrum disorder mice
Xiao-Jie NIU ; Jiao LIU ; Xin-Wei ZHANG ; Ze-Tao WANG ; Ke-Qi YAN ; Qi-Yuan LIU ; Wan-Yun HAO ; Pei-Jun ZHANG
Acta Anatomica Sinica 2025;56(2):171-179
Objective To explore the behavioral patterns and hippocampal neurogenesis of CHD8+mice,and to provide behavioral and morphological basis for improving autism like behavior and neurogenesis.Methods Genotype of wild type(WT)and CHD8+/-mice was identified.Weight measurement was conducted on both male and female mice of the WT and CHD8+/-strains.Subsequently,a battery of behavioral tests was administered,which included three-chamber test,self-grooming test,nesting test,Y-maze spontaneous alternation test,food burial test,open-field test and light-dark transition test.Afterwards,the mice were administered 2%pentobarbital sodium(2 ml/kg)to induce anesthesia.Their brains were frozen with 4%paraformaldehyde,removed for photography and analysis to identify any alterations in brain size.Western blotting and immunofluorescent labeling were used to detect changes in the process of hippocampus neurogenesis.Results Western blotting analysis demonstrated a decrease in the amounts of chromodomain helicase DNA binding protein 8(CHD8)protein in both male and female mice with CHD8+genotype,as compared to WT mice.There were no notable disparities in body weight between male and female WT and CHD8+mice,as well as in brain size.The three-chamber social behavior test revealed that both male and female CHD8+/-mice had social deficiencies(P<0.05).During the open field test,there was no significant difference in the total distance moved by male and female WT and CHD8+/-mice.However,the amount of time spent in the central region was considerably lower in CHD8+/-mice compared to the WT mice(P<0.01).Furthermore,the light-dark transition test revealed that both male and female CHD8+/-mice spent considerably less time investigating the white box compared to the WT mice(P<0.05).Nevertheless,there were no notable alterations found in self-grooming,nesting,spontaneous alternation of Y-maze,and food burial experiments.In addition,Western blotting result demonstrated a significant drop in doublecortin(DCX)expression(P<0.001),and immunofluorescent staining revealed a notable reduction in the number of DCX+cells(P<0.01)in the hippocampus of CHD8+/-mice.Conclusion CHD8+/-mice exhibit social disorders and anxiety-like behaviors,with a decrease in the number of newly generated neurons in the hippocampus and neurogenesis disorders.
4.A SINGLE CASE OF COINFECTION WITH SEVERE FEVER WITH THROMBOCYTOPENIA SYNDROME AND SCRUB TYPHUS IN DALIAN,CHINA
Ke-Ya WU ; Ling-Yan KONG ; Jun XING ; Wei PANG ; Yi ZHOU ; Yu-Hong LIANG ; Sheng-Hao JIN ; Shang QI
Acta Parasitologica et Medica Entomologica Sinica 2025;32(1):48-51
This article reports a first case of combined infection with severe fever with thrombocytopenia syndrome(SFTS)and scrub typhus in Dalian City.The patient was admitted to the hospital due to recurrent fever for 7 days and loss of consciousness for 1 day.Pathogen metagenomic sequencing(mNGS),SFTSV quantitative PCR,and enzyme-linked immunosorbent assay(ELISA)IgM tests were performed,showing positive results for Orientia tsutsugamushi and SFTSV nucleic acids.Based on clinical manifestations and epidemiological history,the patient was diagnosed with combined infections.
5.Pathological image classification model based on pseudo-bag strategy and feature adjustment
Jinling CHEN ; Yanlin SU ; Zhouwei TANG ; Jihong WEI ; Qi KE ; Yuzhu JI ; Ziqing GAO
Chinese Journal of Medical Physics 2025;42(6):775-783
Objective To propose a classification model based on a pseudo-bag strategy and feature adjustment for whole slide imaging in pathology.Methods A pseudo-bag generator was constructed to divide a parent bag into 3 pseudo-bags for increasing the number of training bags.Then,a pseudo-bag learning method based on Nystr?m-based algorithm for approximating self-attention and a selective feature fusion method were employed to process the pseudo-bags.Specifically,the pseudo-bag learning method based on Nystr?m-based algorithm for approximating self-attention reduced computational complexity through an improved multi-head self-attention mechanism while deeply extracting instance features to obtain pseudo-bag classification predictions,thereby enhancing pseudo-bag classification accuracy;and the selective feature fusion method refined pseudo-bag features by filtering and extracting relevant instances.Finally,the model adjusted bag features by extracting confounding factors to avoid interference from irrelevant information and further improve classification accuracy.Results The proposed model was evaluated on two datasets(CAMELYON-16 and TCGA-NSCLC)and compared with 10 other methods,and the results demonstrated that the proposed model achieved the best performance.The proposed method reached an accuracy of 0.943 on the CAMELYON-16 dataset and 0.906 on the TCGA-NSCLC dataset.Conclusion The proposed model can significantly improve the accuracy of whole-slide pathological image classification by effectively mitigating the overfitting and avoiding interference from irrelevant information.
6.A Health Economic Evaluation of an Artificial Intelligence-assisted Prescription Review System in a Real-world Setting in China.
Di WU ; Ying Peng QIU ; Li Wei SHI ; Ke Jun LIU ; Xue Qing TIAN ; Ping REN ; Mao YOU ; Jun Rui PEI ; Wen Qi FU ; Yue XIAO
Biomedical and Environmental Sciences 2025;38(3):385-388
7.Analysis of Clinical Characteristics and Risk Factors for Bone Lesions in Patients with Multiple Myeloma
Chen-Yang LI ; Qi-Ke ZHANG ; Xiao-Fang WEI ; You-Fan FENG ; Yuan FU ; Qiao-Lin CHEN ; Wen-Jie ZHANG ; Yuan-Yuan ZHANG ; Shao-Hua ZHANG ; Shang-Yi ZHANG ; Jie LIU
Journal of Experimental Hematology 2025;33(6):1635-1639
Objective:To investigate the clinical characteristics of patients with multiple myeloma(MM)complicated by bone lesions and the risk factors associated with bone lesions.Methods:The clinical data of 294 newly diagnosed MM patients in Gansu Provincial Hospital from January 2017 to June 2021 were retrospectively analyzed.The patients were divided into the bone lesion group(154 cases)and the non-bone lesions group(140 cases)based on the presence of absence of bone lesions at diagnosis.The general data and laboratory parameters were compared between the two groups.The risk factors for bone lesions in MM patients were analyzed by logistic regression analysis,and the characteristic(ROC)curves were plotted to assess the predictive value of each risk factor for the occurrence of bone lesions in MM patients.Results:Compared to the non-bone lesion group,the bone lesion group had significantly higher serum calcium levels and significantly greater proportions of patients with Durie-Salmon(DS)stage Ⅲ,and bone pain(all P<0.05).Logistic regression analysis showed that elevated serum calcium(OR=5.135,95%CI:1.931-13.653,P=0.001),DS stage Ⅲ(OR=1.841,95%CI:1.019-3.328,P=0.043),and bone pain(OR=8.208,95%CI:4.761-14.151,P<0.001)were independent risk factors for bone lesions in MM patients.ROC curve analysis showed that serum calcium(AUC=0.619,95%CI:0.555-0.683,P<0.001)and bone pain(AUC=0.743,95%CI:0.692-0.793,P<0.001)had predictive value for bone lesions in MM patients.Conclusion:MM patients have a high incidence of bone lesions,and active monitoring and management of risk factors may improve treatment outcomes and prognosis.
8.Machine learning-based prediction of accelerated corneal collagen cross-linking surgery outcomes
Qi WAN ; Li CHEN ; Ran WEI ; Hongbo YIN ; Jing TANG ; Yingping DENG ; Ke MA
Chinese Journal of Experimental Ophthalmology 2025;43(4):323-334
Objective:To use machine learning to predict the efficacy of accelerated corneal collagen cross-linking (A-CXL) surgery, identify prognostic factors, and construct models to predict postoperative disease progression.Methods:A single-center retrospective study was conducted.A total of 82 keratoconus patients (112 eyes) who underwent A-CXL surgery at the West China Hospital of Sichuan University between March and December 2021 were enrolled.Preoperative and follow-up examinations included anterior segment evaluation by slit-lamp microscopy, corneal topography using Pentacam, and corneal biomechanical indices using Corvis ST.Disease progression was defined as an increase in maximum keratometry (Kmax) of ≥1 D from the preoperative level at the last follow-up.Various machine learning algorithms were employed to analyze corneal topography, biomechanical parameters and corneal densitometry values to identify prognostic factors and construct models for predicting postoperative disease progression.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of West China Hospital, Sichuan University (No.2023496).Written informed consent was obtained from each subject.Results:During follow-up, 15.1% (17/112) of the eyes showed progression after A-CXL.The preoperative astigmatism and stress-strain index (SSI) in the progression group were (-5.41±2.72)D and 1.41±0.78, respectively, which were significantly higher than (-3.30±2.54)D and 0.95±0.98 in the non-progression group ( t=2.80, 2.03; both P<0.05).Cox regression analysis identified preoperative astigmatism (hazard ratio [HR]=1.20), SSI (HR=1.10), and anterior corneal densitometry of 2-6 mm (CDA6) (HR=2.10) as significant risk factors for post-A-CXL progression.Among various machine learning models developed and validated, the area under the curve (AUC) values for logistic regression, multilayer perceptron (MLP) model, and random forest (RF) exceeded 0.700.For F1-score, the AUC values for logistic regression, MLP, and RF were 0.870, 0.880, and 0.880, respectively.The network structure of the visualized MLP was a single-layer, 24-neurons neural network with 80% accuracy in predicting whether progression occurred after A-CXL.The clinical nomogram developed in conjunction with astigmatism, SSI, and CDA6 predicted the cumulative probability of progression at 0.5, 1, and 2 years postoperatively based on the sum of the specified values for each variable, and based on the optimal cutoff value, keratoconus corneas could be classified into high-, intermediate-, and low-risk groups, respectively.The time-dependent subject operating characteristic curves of the nomogram showed AUCs of 0.734, 0.685, and 0.935 at 0.5, 1, and 2 years postoperatively, respectively, all of which performed well in predicting progression. Conclusions:Preoperative astigmatism, SSI, and CDA6 are significant risk factors for post-A-CXL progression in keratoconus.The MLP model can accurately predict postoperative disease progression, and the clinical nomogram combining preoperative astigmatism, SSI, and CDA6 can effectively differentiate between low-, medium-, and high-risk postoperative progression outcomes.
9.Established cell model and mechanism of visceral hypersensitivity and nerve hyperplasia in IBS using P815 and N2a co-culture
Hongbin LI ; Chunli GAN ; Xiangyu XIE ; Shan LIU ; Qin LU ; Wei KE ; Shi-yu QI ; Yusheng HUANG ; Hongmei TANG
Chinese Journal of Pathophysiology 2025;41(4):825-832
AIM:To establish a cell model of visceral hypersensitivity and nerve hyperplasia in irritable bowel syndrome(IBS)by conducting an in vitro co-culture of mouse P815 mast cells and N2a nerve cells and explore its possible mechanism.METHODS:Enzyme-linked immunosorbent assay(ELISA)with three replicates was used to confirm the C48/80-induced P815 degranulation.The length of neurites was observed under bright field microscopy to determine the number of differentiated neurons,thereby selecting the concentration of retinoic acid(RA)for stimulating the differentia-tion of N2a cells,with four replicates.A co-culture system of P815 and N2a cells was established using Transwell cham-bers with four replicates.The following groups were established:N2a cells cultured alone,N2a cells co-cultured with P815 cells,N2a cells co-cultured with P815 cells plus C48/80,and N2a cells plus RA group.After co-culturing,the num-ber of differentiated N2a cells was observed under bright field.The expression of nerve growth factor(NGF),tyrosine ki-nase receptor A(TRKA),growth-associated protein-43(GAP43),neuron-specific enolase(NSE),synapsin(SYN),and postsynaptic density protein-95(PSD-95)at both protein and gene levels in N2a cells was detected using Western blot and polymerase chain reaction(PCR),with four replicates.RESULTS:The best condition for N2a differentiation was stimulation with 10 μmol/L RA for 24 hours,whereas the best condition for degranulation was stimulation of P815 cells with 20 mg/L C48/80 for 24 hours.Compared with N2a cells cultured alone,the differentiation ratio of the N2a+P815+C48/80 and N2a+RA groups was significantly increased(P<0.01),and the protein and mRNA expressions of NGF,TRKA,GAP43,NSE,SYN,and PSD-95 were significantly increased(P<0.05).CONCLUSION:Our results revealed that mast cell degranulation enhances the level of nerve hyperplasia in enteric nerve cells and promotes changes in nerve structure and function.Synaptic remodeling regulated by abnormal expression of key proteins such as NGF,TRKA,and GAP43 is involved in the nerve hyperplasia induced by mast cell degranulation.
10.Cell nucleus segmentation in pathological images based on text annotations and Transformer
Jinling CHEN ; Yu CHEN ; Zhuowei TANG ; Jihong WEI ; Qi KE ; Yuzhu JI ; Ziqing GAO
Chinese Journal of Medical Physics 2025;42(10):1328-1336
A VLi-net based cell nucleus segmentation method integrating convolutional neural networks(CNN)and Vision Transformer(ViT)is proposed to address the limitation that the U-Net with CNN as its backbone is only proficient in capturing local features and has a restricted receptive field.Firstly,to mitigate challenges such as high cost of data annotation and insufficient annotated data,text annotations are introduced to enhance the network's understanding of image information.Secondly,to improve the segmentation performance of VLi-net,ViT and CNN are combined to fully extract global and local features,with multi-receptive field convolution features incorporating into the ViT structure for effectively mitigating the issues of limited local information interaction and single feature representation in ViT.Finally,an interactive fusion module(ViFusion)is used to efficiently fuse the multi-level features from the CNN and ViT branches.Experimental results show that VLi-net achieves a Dice coefficient of 80.85%and a mean intersection over union(MIoU)of 66.83%on the MoNuSeg dataset,obtains a Dice coefficient of 80.53%and a MIoU of 67.54%on the DSB-2018 dataset,and has a Dice coefficient of 86.87%and a MIoU of 77.44%on the TNBC dataset.These findings confirm that VLi-net outperforms other methods across multiple experimental metrics.

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