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.CatLet(Hexu)angiographic scoring system
Xue-cheng SONG ; Yang HE ; Xing-hong LIN ; Cai-yun SONG ; Xiu WANG ; Ming-xing XU ; Yong-ming HE
Chinese Journal of Interventional Cardiology 2025;33(4):231-235
This review has introduced the Coronary Artery Tree description and Lesion EvaluaTion(CatLet or Hexu)angiographic scoring system,which,based solely on coronary angiography results,has characterized 6 types of right coronary artery,3 types of left descending artery,and 3 types of diagonal size,together resulting in 54 types of coronary circulation pattern.This novel angiographic scoring system can be utilized to account for coronary anatomy in its diversity,severity and complexity of diseased coronary arteries,and their subtended myocardial territories in jeopardy.The CatLet angiographic scoring system is unique in that the importance of a coronary artery is weighted according to its subtended myocardial segments,by which the variability of coronary artery has been accounted for and measured.Researchers at home and abroad have increasingly paid attention to its clinical utilities,which warrant further validation in the context of large sample size,prospective,and randomized controlled trials.The CatLet angiographic scoring system is accessible at www.catletscore.com.
4.Microchannel-based Electrochemiluminescence Sensor for Tetracycline Detection Using Luminol/Hydrogen Peroxide as Reporter System
Shao-Kun HUANG ; Xiu-Lin XIE ; Hua-Bin CAI ; Yan-Ling HUANG ; Yue LIN ; Zhen-Yu LIN
Chinese Journal of Analytical Chemistry 2025;53(3):356-363
A microchannel-based electrochemiluminescence(ECL)sensor was developed for detection of tetracycline(TC)utilizing luminol/H2O2 as ECL reporting system.The low excitation potential of luminol/H2O2 effectively mitigated the impact of clamping voltage,thereby enhancing the detection performance of the microchannel-based ECL sensor.The microchannel modified with TC aptamer selectively recognized and captured target TC.The positively charged TC reduced the surface charge density within the microchannel,thereby increasing the ionic current in the microchannel,leading to change of ECL signal of system.The experimental conditions such as electrolyte concentration,TC-aptamer concentration,and reaction time between TC and TC-aptamer were optimized.Under optimal conditions,the difference of ECL signal in the absence and presence of TC(?ECL)exhibited a good linear relationship with TC concentration in the range from 1.00 ng/mL to 200 ng/mL,with a detection limit as low as 0.69 ng/mL.The sensor had good selectivity and was successfully used in detection of TC in milk samples.
5.Impact of the interaction between nonalcoholic fatty liver disease and overweight/obesity on the risk of mild cognitive impairment in the elderly
Wanying CAI ; Lang XU ; Yiqing LI ; Chunli LI ; Jing HUANG ; Xiu QU
Chinese Journal of Health Management 2025;19(8):611-616
Objective:To investigate the interaction between non-alcoholic fatty liver disease (NAFLD) and overweight/obesity on the risk of mild cognitive impairment (MCI) in elderly individuals.Methods:This cross-sectional study was based on the Hubei Memory and Aging Cohort Study (HMACS). Cluster random sampling was used to select 5 661 elderly individuals aged≥65 years in Wuhan from 2018 to 2023. Standardized neuropsychological assessments and clinical examinations results were collected. The NAFLD was diagnosed by abdominal ultrasound. The logistic regression analysis was used to analyze the association of NAFLD and overweight/obesity with MCI. The impacts of interaction between NAFLD and overweight/obesity on the risk of MCI were analyzed using both multiplicative and additive models.Results:Among the 5 661 elderly individuals included in the analysis, 2 563 were male and 3 098 were female, with a mean age of (72.24±5.51) years. A total of 2 239 participants (39.6%) resided in rural areas, 2 841 (50.2%) were overweight/obesity, 2 390 (42.2%) had NAFLD, and 1 694 (29.9%) were diagnosed with MCI. The risk of MCI in elderly individuals with NAFLD and overweight/obesity was 2.975 times ( OR=2.975, 95% CI: 2.489-3.557, P<0.001) of that in non-overweight/obese individuals without NAFLD. There was a multiplicative interaction between NAFLD and overweight/obesity on MCI ( OR=1.508, 95% CI: 1.169-1.944, P=0.002). NAFLD and overweight/obesity had an additive interaction effect on the risk of MCI, and the relative excess risk of interaction, attributable proportion of interaction and the synergy index was 1.099 (95% CI: 0.630-1.593), 0.369 (95% CI: 0.222-0.487), 2.256 (95% CI: 1.457-3.492), respectively. Conclusion:There is an interaction between NAFLD and overweight/obesity in elderly individuals, and the co-existence of NAFLD and overweight/obesity increases the risk of MCI in this population.
6.MRI Characteristics and Differential Diagnosis of Benign and Malignant Ductal Lesions with Microcalcifications Detected by Mammography
Lin CHEN ; Chun-hong ZHENG ; Feng JIANG ; Xiang-xiu ZHANG ; An-wen CAI
Progress in Modern Biomedicine 2025;25(12):2034-2041
Objective:To investigate the MRI characteristics of ductal lesions with microcalcifications detected by mammography,and to evaluate the value of MRI in the differential diagnosis of benign and malignant ductal lesions.Methods:The clinical data of 112 patients with pathologically confirmed ductal lesions with microcalcifications detected by mammography in our hospital from January 2022 to June 2024 were retrospectively analyzed.All patients underwent mammography and MRI examinations.MRI morphological features,dynamic enhancement characteristics,diffusion-weighted imaging(DWI)findings,and apparent diffusion coefficient(ADC)values were analyzed and compared with pathological results.The diagnostic performance of various MRI features was analyzed using ROC curves.Results:Among the 112 patients,there were 47 benign lesions and 65 malignant lesions.Malignant lesions were more likely to present with irregular morphology,heterogeneous T2 signal,lobulation,and spiculation(P<0.05),while benign lesions were more likely to present with round or oval shapes and homogeneous T2 signal(P<0.05).Malignant lesions predominantly showed fast rise-fast washout(Washout type)enhancement curves(58.5%),while benign lesions predominantly showed persistent rise(Progressive type)enhancement curves(55.3%).The ADC values of malignant lesions(0.92±0.21× 10-3 mm2/s)were significantly lower than those of benign lesions(1.45±0.28× 10-3 mm2/s)(P<0.001).The combined application of morphological features,dynamic enhancement curves,and ADC values had the highest diagnostic performance,with a sensitivity of 92.3%,specificity of 89.4%,and accuracy of 91.1%.Conclusion:Multi-parameter MRI can comprehensively evaluate ductal lesions with microcalcifications detected by mammography.The combined application of morphological features,dynamic enhancement curve types,and ADC values can effectively improve the accuracy of differential diagnosis between benign and malignant lesions,providing important basis for clinical treatment decisions.
7.Analysis of the Influencing Factors and Short-Term Prognosis of Early Onset Coronary Heart Disease in Women in Wansheng District of Chongqing
Xiu-ping LOU ; Shi-cai LAN ; Hai-na FAN ; Yan WANG ; Sheng ZHANG ; Nong-hao WEN ; Rui-peng WEI
Progress in Modern Biomedicine 2025;25(20):3247-3253
Objective:To explore the incidence status,influencing factors and short-term prognosis characteristics of early onset coronary heart disease in women in Wansheng District of Chongqing,and to provide scientific basis for formulating regional prevention and treatment strategies.Methods:This study was a single-center retrospective study,100 coronary heart disease in women from January 2022 to December 2023 at Chongqing Wansheng Economic and Technological Development Zone People's Hospital were prospective selected,and they were divided into early onset group of 40 cases(≤ 65 years old)and late onset group of 60 cases(>65 years old)based on their age of onset.Another 60 healthy women who underwent physical examinations during the same period to exclude coronary heart disease were selected as the control group.Univariate factor and multiple factor logistic regression analysis were used to identify independent risk factors for early onset coronary heart disease in women.Draw receiver operating characteristic(ROC)curve for the subjects,the efficacy of risk factors in predicting early onset coronary heart disease based on the area under the curve(AUC)of ROC curve were evaluated.Patients were followed up for 1 year to observe the occurrence of major adverse cardiovascular events(MACE).Result:Among 100 fcoronary heart disease in women,the early onset group accounted for 40.00%(40/100).Univariate analysis showed that age,hyperlipidemia history,smoking history,hypertension history,family history,diabetes history,total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C)were related to the early onset coronary heart disease.Multivariate analysis showed that,hyperlipidemia history(OR=4.124,95%CI:2.343-7.217),smoking history(OR=3.564),hypertension(OR=3.253),family history(OR=2.981),diabetes history(OR=2.873)were independent risk factors.ROC curve analysis results showed that joint evaluation had the best predictive value,with AUC of 0.829,which was higher than the AUC of individual evaluation for each factor.The incidence of MACE in the early onset group(45.00%)was significantly higher than that in the late onset group(P<0.05).Conclusion:Early onset coronary heart disease in women in Wansheng District of Chongqing is related to the hyperlipidemia history,smoking,hypertension history,family history and diabetes history.The incidence of MACE in early-onset patients followed up for 1 year is higher than that in late-onset patients.
8.Research progress on the mechanism of action of rosmarinic acid in the prevention of cardiovascular diseases
Ke CAI ; Sheng-ru HUANG ; Fang-fang GAO ; Xiu-juan PENG ; Sheng GUO ; Feng LIU ; Jin-ao DUAN ; Shu-lan SU
Acta Pharmaceutica Sinica 2025;60(1):12-21
With the rapid development of social economy and the continuous improvement of human living standard, the incidence, fatality and recurrence rates of cardiovascular disease (CVD) are increasing year by year, which seriously affects people's life and health. Conventional therapeutic drugs have limited improvement on the disability rate, so the search for new therapeutic drugs and action targets has become one of the hotspots of current research. In recent years, the therapeutic role of the natural compound rosmarinic acid (RA) in CVD has attracted much attention, which is capable of preventing CVD by modulating multiple signalling pathways and exerting physiological activities such as antioxidant, anti-apoptotic, anti-inflammatory, anti-platelet aggregation, as well as anti-coagulation and endothelial function protection. In this paper, the role of RA in the prevention of CVD is systematically sorted out, and its mechanism of action is summarised and analysed, with a view to providing a scientific basis and important support for the in-depth exploration of the prevention value of RA in CVD and its further development as a prevention drug.
9.Recombinant human LAG3 lentiviral vector and its stable expression in mouse fibroblast cells
China Tropical Medicine 2025;25(3):328-
Objective To construct a recombinant lentiviral expression vector for human lymphocyte activation gene 3 (LAG3) and generation of monoclonal cell lines that preferentially express LAG3 by transfection of the vector into mouse fibroblast cells 3T3. Methods After extracting total RNA extracted from human peripheral blood mononuclear cells, the RNA is reversely transcribed into cDNA. The LAG3 extracellular and transmembrane region sequences are amplified by PCR using high-fidelity DNA polymerase. The PCR products are double-digested with the restriction endonucleases EcoRⅠ and NotⅠ, then ligated with the lentiviral vector pTSB-copGFP to construct the recombinant expression vector pTSB-LAG3-copGFP, which is subsequently transformed into Escherichia coli DH5α. Positive clonal bacteria are selected by PCR, and the plasmids are extracted and sequenced for verification. The recombinant vector pTSB-LAG3-copGFP, along with packaging plasmids psPAX2 and pMD2.0G, are co-transfected into human embryonic kidney 293T cells to assemble and release virus particles, the virus infected 3T3 cells were collected. During the puromycin selection of infected 3T3 cells, the limited dilution method is used to obtain 3T3 monoclonal cells that stably express LAG3. Real-time fluorescent quantitative PCR, immunofluorescence and flow cytometry were utilized to verify the transcription of LAG3 mRNA and the expression of LAG3 protein respectively. Results Sequencing of the recombinant pTSB-LAG3-copGFP lentiviral vector plasmid reveals that the amplified LAG3 sequence contains a synonymous mutation in the His codon at nucleotide position 1 697 bp within the LAG3 transmembrane region, which aligns with the standard LAG3 sequence (accession number NM_002286.6) in GenBank. The 3T3 cells infected by pTSB-LAG3-copGFP packaging virus screened with puromycin. A total of 20 LAG3+copGFP+-3T3 monoclonal cell lines were obtained, all of which exhibited transcription of LAG3 mRNA. The monoclonal cell line MC-6 exhibits the highest transcriptional level of LAG3. Effective expression and distribution of LAG3 protein on the cell membrane and cytoplasmic organelle membranes in MC-6 indicated by immunofluorescence and flow cytometry. Conclusion The pTSB-LAG3-copGFP lentiviral vector was successfully constructed. LAG3+copGFP+-3T3 monoclonal cell lines overexpressing lymphocyte activating 3 were efficiently established, laying the foundation for subsequent studies on the relationship between LAG3 and the development of chronic infectious diseases such as hepatitis B, as well as the interventional treatment of LAG3.
10.Molecular characteristics and genetic evolution analysis of CRISPR loci in Listeria monocytogenes
DU Bo ; WU Ying ; CAI Nannan ; REN Yanyan ; XIU Min ; LIU Wenxin
China Tropical Medicine 2025;25(3):343-
Objective To detect clustered regularly interspaced short palindromic repeats (CRISPR) in Listeria monocytogenes, and analyze the structure and homology of CRISPR loci. Methods Totally 34 strains of Listeria monocytogenes isolated in our laboratory were identified, PCR amplified and sequenced. The repeat sequence structure and spacer sequence homology in CRISPR loci were analyzed by bioinformatics software. Results A total of 7 CRISPR loci were detected in 34 strains. The mutation rate of the first 2 and last 2 bases of the Repeat sequence of CRISPR loci was higher, while the mutation rate of the middle part was lower. Seven CRISPR sites form eight CRISPR structural types, among which the Repeat sequences of CRISPR1 and CRISPR2 are relatively conserved, while the Repeat sequences of CRISPR1 and CRISPR5 can form dumbbell shaped secondary structures. The number of Spacer sequences contained in each CRISPR site ranges from 2 to 15, with an average of 2.43. The 136 Spacer sequences detected were not only homologous to Listeria plasmids and bacteriophages, but also homologous to uncultured virus sequences, staphylococcal bacteriophages, and Listeria innocua. The same CRISPR genotype did not show large-scale clustering, but some strains in the same year were in the same evolutionary cluster with close genetic relationships. Conclusion The CRISPR structure of Listeria monocytogenes in this study exhibits high specificity, and its homology with bacteriophages provides a theoretical basis for the application of bacteriophages in the control and prevention of Listeria monocytogenes.

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