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.Experimental and Computational Investigation of pH-Dependent Urease Conformational Dynamics and Its Impact on MICP Efficiency
Qiu-Cai ZHANG ; Yi-Fei ZHENG ; Mei-Zhong HUANG ; Xiu-Kang SHEN ; Ling-Ling WU ; Zhi-Jun ZHANG
Chinese Journal of Biochemistry and Molecular Biology 2025;41(6):879-894
The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(<0.5 ?),the longest hydrogen bond lifetime(>8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(~120 ?3)and moderate conformational coherence(correlation coefficient~0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.
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.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.
6.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.
7.Application effect of hand-sewn esophagojejunostomy in totally laparoscopic total gastrectomy for gastric cancer
Sheng-hui MA ; Jia REN ; Xin WANG ; Xiu-xia SHI ; Shu-yun CAI
Journal of Regional Anatomy and Operative Surgery 2025;34(5):431-434
Objective To explore the clinical effect of totally laparoscopic total gastrectomy combined with hand-sewn esophagojejunos-tomy for gastric cancer.Methods Ninety cases of gastric cancer patients were seleted,of which 45 cases undergoing Roux-en-Y esophagoje-junostomy for digestive tract reconstruction were set as the control group,while 45 cases undergoing hand-sewn esophagojejunostomy for digestive tract reconstruction were set as the observation group.Patients in the control group underwent laparoscopic-assisted total gastrectomy combined with Roux-en-Y esophagojejunostomy to reconstruct digestive tract,while patients in the observation group underwent totally laparoscopic total gastrectomy combined with hand-sewn esophagojejunostomy to reconstruct digestive tract.The perioperative indicators and complications of patients in the two groups were compared.Results The surgical time,time of esophagojejunostomy,and time to get out of bed after surgery of patients in the observation group were significantly shorter than those in the control group(P<0.05),the pain score 24 hours after surgery was significantly lower than that in the control group(P<0.05).There was no statistically significant difference between the two groups in terms of the incidence of complications or Clavien-Dindo grading(P>0.05).Conclusion Hand-sewn esophagojejunostomy for digestive tract reconstruction has a good clinical effect in gastric cancer during totally laparoscopic total gastrectomy.It can shorten the surgical time and time of esophagojejunostomy,reduce postoperative pain,and accelerate postoperative recovery,whose safety is comparable to Roux-en-Y esophagojejunostomy.
8.Diagnostic Techniques and Risk Prediction for Cardiovascular-kidney-metabolic (CKM) Syndrome
Song HOU ; Lin-Shan ZHANG ; Xiu-Qin HONG ; Chi ZHANG ; Ying LIU ; Cai-Li ZHANG ; Yan ZHU ; Hai-Jun LIN ; Fu ZHANG ; Yu-Xiang YANG
Progress in Biochemistry and Biophysics 2025;52(10):2585-2601
Cardiovascular disease (CVD), chronic kidney disease (CKD), and metabolic disorders are the 3 major chronic diseases threatening human health, which are closely related and often coexist, significantly increasing the difficulty of disease management. In response, the American Heart Association (AHA) proposed a novel disease concept of “cardiovascular-kidney-metabolic (CKM) syndrome” in October 2023, which has triggered widespread concern about the co-treatment of heart and kidney diseases and the prevention and treatment of metabolic disorders around the world. This review posits that effectively managing CKM syndrome requires a new and multidimensional paradigm for diagnosis and risk prediction that integrates biological insights, advanced technology and social determinants of health (SDoH). We argue that the core pathological driver is a “metabolic toxic environment”, fueled by adipose tissue dysfunction and characterized by a vicious cycle of systemic inflammation and oxidative stress, which forms a common pathway to multi-organ injury. The at-risk population is defined not only by biological characteristics but also significantly impacted by adverse SDoH, which can elevate the risk of advanced CKM by a factor of 1.18 to 3.50, underscoring the critical need for equity in screening and care strategies. This review systematically charts the progression of diagnostic technologies. In diagnostics, we highlight a crucial shift from single-marker assessments to comprehensive multi-marker panels. The synergistic application of traditional biomarkers like NT-proBNP (reflecting cardiac stress) and UACR (indicating kidney damage) with emerging indicators such as systemic immune-inflammation index (SII) and Klotho protein facilitates a holistic evaluation of multi-organ health. Furthermore, this paper explores the pivotal role of non-invasive monitoring technologies in detecting subclinical disease. Techniques like multi-wavelength photoplethysmography (PPG) and impedance cardiography (ICG) provide a real-time window into microcirculatory and hemodynamic status, enabling the identification of early, often asymptomatic, functional abnormalities that precede overt organ failure. In imaging, progress is marked by a move towards precise, quantitative evaluation, exemplified by artificial intelligence-powered quantitative computed tomography (AI-QCT). By integrating AI-QCT with clinical risk factors, the predictive accuracy for cardiovascular events within 6 months significantly improves, with the area under the curve (AUC) increasing from 0.637 to 0.688, demonstrating its potential for reclassifying risk in CKM stage 3. In the domain of risk prediction, we trace the evolution from traditional statistical tools to next-generation models. The new PREVENT equation represents a major advancement by incorporating key kidney function markers (eGFR, UACR), which can enhance the detection rate of CKD in primary care by 20%-30%. However, we contend that the future lies in dynamic, machine learning-based models. Algorithms such as XGBoost have achieved an AUC of 0.82 for predicting 365-day cardiovascular events, while deep learning models like KFDeep have demonstrated exceptional performance in predicting kidney failure risk with an AUC of 0.946. Unlike static calculators, these AI-driven tools can process complex, multimodal data and continuously update risk profiles, paving the way for truly personalized and proactive medicine. In conclusion, this review advocates for a paradigm shift toward a holistic and technologically advanced framework for CKM management. Future efforts must focus on the deep integration of multimodal data, the development of novel AI-driven biomarkers, the implementation of refined SDoH-informed interventions, and the promotion of interdisciplinary collaboration to construct an efficient, equitable, and effective system for CKM screening and intervention.
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.

Result Analysis
Print
Save
E-mail