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.Impact of ischemia time and storage periods on RNA quality of fresh-frozen breast cancer and esophageal cancer tissue samples in biobank
Yang-si ZHENG ; Xuan-hao LIN ; Fan LI ; Kun-sheng XIAO ; Xi-feng CHEN ; Chun-peng LIU ; Pei-xiu YAO ; Shao-hong WANG
Fudan University Journal of Medical Sciences 2025;52(3):437-445
Objective To investigate the effects of ischemia time and storage periods on RNA quality in fresh-frozen breast cancer(BC)and esophageal cancer(EC)tissue samples in order to establish evidence-based protocols for biobank sample management.Methods The tumor(T)and paired normal(N)tissue samples from 6 cases of BC and 6 cases of EC were collected and cryopreserved in Biobank,Shantou Central Hospital.Mirror paraffin-embedded tissues were simultaneously prepared into sections for morphological analysis.The samples were divided into two groups of<15 min and 15-30 min according to ischemia time,and RNA quality was analyzed at 4 storage periods of 8-10 months(T1),14-16 months(T2),26-28 months(T3)and 38-40 months(T4).Results In 96 analyzed samples,93.8%(90/96)exhibited high quality(RIN≥6),with 89.6%(43/48)in BC and 97.9%(47/48)in EC.Significant differences in RIN were observed between BC group and EC group(8.050 vs.8.600,P=0.009).In EC group,RIN value was significantly negatively correlated with RNA yield(P<0.001).Moreover,RIN values of tumor-normal pairs exhibited markedly significant differences(7.550 vs.9.000,P<0.001).In contrast,no significant difference was detected in BC group(8.200 vs.7.700,P=0.348).Statistical analysis showed that RIN value was positively correlated with 28S/18S(P<0.001),but had no correlation with tumor content(P=0.676)and necrotic content(P=0.055).Neither ischemia time(<15 min vs.15-30 min:8.200 vs.8.300,P=0.932)nor storage periods(T1-T4:8.400,7.700,8.450,8.600,P=0.163)compromised RNA quality.Conclusion Organ origin and tissue type could influence RNA quality of fresh-frozen tissue samples.However,limited ischemia time(≤30 min)and long-term storage period(38-40 months)do not adversely affect RNA quality in fresh-frozen breast cancer and esophageal cancer tissue samples.
4.caspase-8-dependent cell death mode and cerebral ischemia/reperfusion injury
Yan-xi CHE ; Xiu-ju LUO ; Jun PENG
Chinese Pharmacological Bulletin 2025;41(12):2240-2245
Caspase-8 is a cysteine-aspartate protease widely dis-tributed in cells.As a molecular"switch",caspase-8 is involved in the regulation of various modes of cell death,including apopto-sis,necroptosis and pyroptosis.During cerebral ischemia/reper-fusion,caspase-8 activation is one of the key factors inducing neuronal cell death.Currently there are both specific inhibitors of caspase-8,such as Z-IETD-FMK and Ac-IETD-CHO,as well as a variety of pan-caspase inhibitors,such as z-VAD,Q-VD-OPH,and enricosan.Both animal and cellular experiments have demonstrated that all of these inhibitors attenuate cerebral ische-mia/reperfusion injury,an effect that involves inhibition of caspase-8 activity and reduction of neuronal apoptosis.Clinical-ly,certain drugs for ischemic stroke reduce plasma caspase-8 ac-tivity,suggesting that caspase-8 may be a biomarker for the diag-nosis and prognosis of ischemic stroke.Finding and developing clinically valuable inhibitors around caspase-8 is expected to provide new ideas for new drug development in ischemic stroke.
5.Investigation on Risk Stratification of Atherosclerotic Cardiovascular Disease and Target Achievement of Lipid and Blood Pressure in Community-Based Hypertensive Patients
Yun-li PENG ; Lu-qiang YIN ; Jie-tao LU ; Qin XIAO ; Xiu-lan ZHU
Progress in Modern Biomedicine 2025;25(14):2315-2321
Objective:This study aimed to investigate the atherosclerotic cardiovascular disease(ASCVD)risk stratification and target achievement of lipid and blood pressure control among community-based hypertensive patients,with the goal of optimizing integrated management strategies.Methods:A total of 2832 hypertensive patients registered in 2021 at the Bicheng Community Health Service Center in Bishan District of Chongqing,were included.Baseline data were collected through retrospective analysis of health records.Non-high-density lipoprotein cholesterol(non-HDL-C)levels and estimated glomerular filtration rate(eGFR)were calculated.ASCVD risk stratification was performed,and target achievement for lipid and blood pressure control were analyzed,including comparisons among patients with different comorbidities.Results:Based on ASCVD risk stratification,patients were categorized as follows:ultra-high risk(22 cases,0.78%),very high risk(111 cases,3.92%),high risk(1324 cases,46.75%),moderate risk(997 cases,35.20%),and low risk(378 cases,13.35%).The LDL-C target achievement rate was 4.55%(1/22)in the ultra-high risk group and 15.32%(17/111)in the very high risk group,with blood pressure target achievement rate of 18.18%(4/22)and 11.71%(13/111),respectively.In the high-risk group,LDL-C and blood pressure target achievement rate were only 4.76%(63/1324)and 8.08%(107/1324),while moderate-risk groups showed 25.68%(256/997)and 26.18%(261/997),respectively.The low-risk group achieved 99.74%(377/378)LDL-C target achievement and 30.69%(116/378)blood pressure target achievement.Patients with ischemic stroke had a significantly higher lipid target achievement rate(13.73%,7/51)compared to non-ischemic stroke patients(6.40%,178/2781)(P<0.05).Similarly,those with coronary heart disease(12.65%,13/87)exhibited higher lipid target achievement than non-coronary heart disease patients(6.27%,172/2745)(P<0.05).However,no significant difference was observed between hypertensive patients with diabetes(8.04%,52/647)and non-diabetic patients(6.09%,133/2185)(P>0.05),or between those with chronic kidney disease(CKD)stages 3/4(6.72%,16/238)and non-CKD 3/4 patients(6.52%,169/2594)(P>0.05).Conclusion:Over half of the community-based hypertensive patients were classified as high-risk or above in ASCVD stratification,yet their lipid and blood pressure target achievement rates were markedly suboptimal.Hypertension patients with comorbidities,particularly diabetes or CKD stages 3/4,showed poor lipid target achievement.These findings underscore the necessity of incorporating ASCVD risk stratification into community management assessments for hypertensive patients,enhancing personalized management for high-risk populations,and prioritizing lipid target achievement in those with diabetes or CKD stages 3/4.
6.Cross-fusion skip connection mechanism-based abdominal organ segmentation method
Chinese Medical Equipment Journal 2025;46(11):1-9
Objective To propose an abdominal organ segmentation method based on a cross-fusion skip-connection mechanism to enhance the overall segmentation effect of abdominal organs.Methods Firstly,the Swin-Unet network was used as the baseline segmentation model,into which an enhanced dual cross attention(EDCA)module was integrated to refine features by fusing multi-scale encoder features;secondly,a decoder-guided cross-fusion attention(DCFA)module was added to reconstruct encoder information under the guidance of decoder features so as to mitigate the semantic gap between the features of the encoder and decoder;finally,a cross-fusion skip-connection mechanism was designed based on EDCA and DCFA modules to achieve effective feature transmission from encoder to decoder features.The cross-fusion skip connection mechanism-based abdominal organ segmentation model had its effectiveness validated by the experiments carried out on Synapse multi-organ CT dataset and comparison with some mainstream abdominal organ segmentation models including TransUNet,UNetR,UCTransNet,MT-UNet and Swin-Unet.Results The Swin-Unet model based on the cross-fusion skip connection mechanism achieved a Dice similarity coefficient(DSC)of 80.30%and a Hausdorff distance(HD)of 18.26 mm,outperforming the other mainstream abdominal organ segmentation models.Moreover,the model proposed had the number of parameters(27.18M)and floating-point operations per second(6.16×10?/s)both superior to those of the other mainstream abdominal organ segmentation models while close to those of Swin-Unet.Conclusion The proposed method effectively enhances the segmentation of abdominal organs,providing an effective design approach for optimizing segmentation models based on U-shaped structures.
7.Value of DCE-MRI quantitative parameters in differential diagnosis of brain metastases from non-small cell lung cancer
Rui-peng LIANG ; Yong-long LI ; Hao-tian WANG ; Dan SU ; Xiu-fu ZHANG ; Jun ZHOU
Chinese Medical Equipment Journal 2025;46(5):54-59
Objective To evaluate the value of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)in differentiating histopathological types of brain metastases from non-small cell lung cancer(NSCLC).Methods Sixty-eight patients with brain metastases confirmed by pathology were collected,including 47 lung adenocarcinoma patients divided into a lung adenocarcinoma group and 21 lung squamous cell carcinoma patients into a lung squamous cell carcinoma group.The two groups were compared in terms of the DCE-MRI derived parameters including volume transfer constant(Ktrans),extra vascular extracellular volume fraction(Ve)and plasma volume fraction(Vp);ROC curves were used to assess the diagnostic efficacy of different quantitative parameters for the pathologic types of brain metastases from lung adenocarcinoma group or lung squamous cell carcinoma.SPSS 22.0 software was used for statistical analysis.Results The lung adenocarcinoma group had the values of Ktrans,Ve,Vp and Ve+Vp higher than those of the lung squamous cell carcinoma group,with the differences being statistically significant(all P<0.05).ROC curve analysis results showed that Ktrans,Vp and Ve had high differential diagnosis values for the pathologic types of brain metastases from lung adenocarcinoma group or lung squamous cell carcinoma,with the AUC being 1.000,0.998 and 0.875,the optimal Youden index being 0.183 min-1,0.039 and 0.270,the sensitivity being 100.00%,100.00%and 80.56%and the specificity being 100.00%,97.06%and 80.88%,respectively.Conclusion The quantitative parameters of DCE-MRI gain advantages in the differential diagnosis of NSCLC brain metastases,and provide references for the diagnosis and treatment of brain metastases of lung cancer.[Chinese Medical Equipment Journal,2025,46(5):54-59]
8.Cross-fusion skip connection mechanism-based abdominal organ segmentation method
Chinese Medical Equipment Journal 2025;46(11):1-9
Objective To propose an abdominal organ segmentation method based on a cross-fusion skip-connection mechanism to enhance the overall segmentation effect of abdominal organs.Methods Firstly,the Swin-Unet network was used as the baseline segmentation model,into which an enhanced dual cross attention(EDCA)module was integrated to refine features by fusing multi-scale encoder features;secondly,a decoder-guided cross-fusion attention(DCFA)module was added to reconstruct encoder information under the guidance of decoder features so as to mitigate the semantic gap between the features of the encoder and decoder;finally,a cross-fusion skip-connection mechanism was designed based on EDCA and DCFA modules to achieve effective feature transmission from encoder to decoder features.The cross-fusion skip connection mechanism-based abdominal organ segmentation model had its effectiveness validated by the experiments carried out on Synapse multi-organ CT dataset and comparison with some mainstream abdominal organ segmentation models including TransUNet,UNetR,UCTransNet,MT-UNet and Swin-Unet.Results The Swin-Unet model based on the cross-fusion skip connection mechanism achieved a Dice similarity coefficient(DSC)of 80.30%and a Hausdorff distance(HD)of 18.26 mm,outperforming the other mainstream abdominal organ segmentation models.Moreover,the model proposed had the number of parameters(27.18M)and floating-point operations per second(6.16×10?/s)both superior to those of the other mainstream abdominal organ segmentation models while close to those of Swin-Unet.Conclusion The proposed method effectively enhances the segmentation of abdominal organs,providing an effective design approach for optimizing segmentation models based on U-shaped structures.
9.Atlantodentoplasty using the anterior retropharyngeal approach for treating irreducible atlantoaxial dislocation with atlantodental bony obstruction: a retrospective study
Jia SHAO ; Yun Peng HAN ; Yan Zheng GAO ; Kun GAO ; Ke Zheng MAO ; Xiu Ru ZHANG
Asian Spine Journal 2025;19(1):54-63
Methods:
The clinical data of 26 patients diagnosed with irreducible atlantoaxial dislocation complicated by atlantodental bony obstruction were analyzed retrospectively. All patients underwent anterior retropharyngeal atlantodentoplasty, followed by posterior occipitocervical fusion. Details including surgical duration and blood loss volume were recorded. Radiographic data such as the anterior atlantodental interval, O–C2 angle, space available for the cord, clivus–canal angle, and cervical medullary angle, and clinical data including the Japanese Orthopedic Association (JOA) score were assessed. The fusion time of the grafted bone and the development of complications were examined.
Results:
In patients undergoing anterior retropharyngeal atlantodentoplasty, the surgical duration and blood loss volume were 120.1±16.4 minutes and 100.6±33.5 mL, respectively. The anterior atlantodental interval decreased significantly after the surgery (p <0.001). The O–C2 angle, space available for the cord, clivus–canal angle, and cervical medullary angle increased significantly after the surgery (p <0.001). The JOA score during the latest follow-up significantly increased compared with that before the surgery (p <0.001). The improvement rate of the JOA score was 80.8%±18.1%. The fusion time of the grafted bone was 3–8 months, with an average of 5.7±1.5 months. In total, 11 patients presented with postoperative dysphagia and three with irritating cough. However, none of them exhibited other major complications.
Conclusions
Anterior retropharyngeal atlantodentoplasty can anatomically reduce the atlantoaxial joint with a satisfactory clinical outcome in patients with irreducible atlantoaxial dislocation with atlantodental bony obstruction.
10.Clinical Study of Repeated Transcranial Magnetic Stimulation Combined with Mindfulness-Based Cognitive Therapy in Patients with Alcohol Withdrawal Syndrome
Xiao-ling LIU ; Hong-he ZHANG ; Jun-ling YE ; Xiu-ying ZHENG ; Zi-yan PENG ; Dan-ni HUANG
Progress in Modern Biomedicine 2025;25(11):1847-1854,1878
Objective:To observe the clinical efficacy of repetitive transcranial magnetic stimulation(rTMS)combined with mindfulness-based cognitive therapy(MBCT)in patients with alcohol withdrawal syndrome(AWS).Methods:The 120 patients with AWS who were observed in this study were all male patients admitted to our hospital from June 2021 to June 2024,the patients were divided into group A(conventional treatment,40 cases),group B(group A combined with rTMS,40 cases),and group C(group B combined with MBCT,40 cases)according to random number table method.The clinical efficacy,self-control ability[Modified Clinical Institution Alcohol Dependence Withdrawal Assessment Scale(CIWA-Ar)score,Visual Analog Scale of Psychological Craving for Alcohol(VAS)score and Pennsylvania Alcohol Craving Scale(PACS)score],anxiety and depression degree assessment[Hamilton Depression Scale(HAMD)score,Hamilton Anxiety Scale(HAMA)score]and quality of life[36 Short Form Health Survey(SF-36)Score],relapse rate and readmission rate were compared among the three groups.Results:The total effective rate of group A,group B and group C increased successively(P<0.05).The CIWA-Ar,PACS and VAS scores in group B and group C after treatment were lower than those in group A,and group C was lower than that in group B(P<0.05).The HAMD and HAMA scores of group B and group C after treatment were lower than those in group A,and group C was lower than that in group B(P<0.05).The SF-36 score of group B and group C after treatment was higher than those in group A,and group C was higher than that in group B(P<0.05).Relapse rate and readmission rate in groups B and C were lower than those in group A,and group C was lower than that in group B(P<0.05).Conclusion:The application of rTMS combined with MBCT in patients with AWS can improve clinical efficacy and quality of life,alleviate anxiety and depression,improve patients' self-control ability,reduce relapse rate and readmission rate,with definite effects.

Result Analysis
Print
Save
E-mail