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.Role of EBP50 in renal tubular epithelial-mesenchymal transition in diabetic nephropathy
Xiaofei XIU ; Xiaomei WANG ; Tao ZHANG ; Xuelan XIAO ; Hongjing SUN ; Zinan GUO ; Feng GAO
Journal of Chinese Physician 2025;27(5):678-681
Objective:To investigate the role of ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) in renal tubular epithelial-mesenchymal transition (EMT) in diabetic nephropathy (DN).Methods:Renal tissue specimens from 24 DN patients (DN group) confirmed by medical history, clinical laboratory tests, and pathological diagnosis at the Third Hospital of Hebei Medical University and 15 adjacent normal renal tissues (control group) from 2018 to 2023 were collected. Immunohistochemical staining was performed to detect the expression of EBP50, E-cadherin, and Vimentin proteins. Additionally, 10 healthy volunteers were enrolled as a normal group, and fasting blood glucose, serum creatinine, blood urea nitrogen, and 24 h urinary protein levels were compared between DN patients and the normal group.Results:Fasting blood glucose, serum creatinine, blood urea nitrogen, and 24 h urinary protein levels were significantly higher in the DN group than in the normal group (all P<0.01). Periodic acid-schiff (PAS) staining revealed significant thickening of the glomerular basement membrane, increased extracellular matrix, vacuolar degeneration of renal tubules, and elevated extracellular matrix in the renal interstitium in the DN group. Immunohistochemistry showed higher expression of EBP50 and E-cadherin proteins in the control group than in the DN group (all P<0.01), while Vimentin expression was lower in the control group ( P<0.01). Conclusions:EBP50 is involved in the EMT process of renal tubules in DN and is associated with tubular injury.
4.The Relationship between Ig Class Switch Recombination and MMR Protein,Microsatellite Phenotype in Extranodal Marginal Zone Lymphoma of Mucosa-associated Lymphoid Tissue
Hong-Xia WANG ; Jun CHEN ; Jing LI ; Guo-Feng LU ; Xiu-Hua HAN ; Rong YANG ; Ya-Jun JIANG
Journal of Experimental Hematology 2025;33(4):1036-1041
Objective:To investigate the relationship between Ig class switch recombination(CSR)and mismatch repair(MMR)protein,microsatellite phenotype in extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue(MALT lymphoma).Methods:Forty cases of MALT lymphoma archived in the Department of Pathology,Jiading District Central Hospital,Shanghai University of Medicine & Health Sciences were selected as the observation group,and twenty cases of benign lymphoid tissue hyperplasia were as the control group.The expressions of IgG,IgM,IgD,and IgA in both groups were detected by immunohistochemical double staining,and MMR proteins including MLH1,MSH2,MSH6,and PMS2 in both groups were detected by immunohistochemistry.Multiplex fluorescence PCR capillary electrophoresis was used to detect microsatellite phenotype in tumor and adjacent tissues of the experimental group.Results:In the observation group,the proportions of single Ig heavy chain expression(mode Ⅰ),negative expression(mode Ⅱ),and multiple expression(mode Ⅲ)were 65%(26/40),27.5%(11/40),and 7.5%(3/40),respectively,while in the control group were 0(0/20),5%(1/20),and 95%(19/20).The proportion of Ig heavy chain expression mode Ⅰ+Ⅱ in the observation group was 92.5%,which was significantly higher than 5%in the control group(P<0.0 1).In the observation group,partial deletion of MMR protein was observed in 3 cases(7.5%),including 2 cases of MSH6 deletion and 1 case of both MSH6 and PMS2 deletion.In the control group,there was 1 case(5%)with PMS2 deletion.There was no significant difference in the deletion rate of MMR protein between the two groups(P>0.05).A total of 5 cases of microsatellite instability(MSI)were detected in the observation group,including 1 case of low-frequency MSI(MSI-L),4 cases of high-frequency MSI(MSI-H),and 2 cases of MSI-H with MSH6 deletion.When the loss expression of MSI-H or MMR protein was counted as a positive result,the MSI-H rate detected by PCR capillary electrophoresis was 10%(4/40),which was slightly higher than the MMR protein deletion rate detected by immunohistochemistry(7.5%,3/40),but there was no statistically significant difference between the two groups(P>0.05).The MMR protein deletion rates among the Ig heavy chain protein expression mode Ⅰ,mode Ⅱ,and mode Ⅲ groups were 0(0/26),18.2%(2/11),and 33.3%(1/3),respectively.There was a statistically significant difference in the constituent ratios among the three groups(P<0.05).The MMR protein deletion rates among the MSS,MSI-L,and MSI-H groups were 2.9%(1/35),0(0/1),and 50%(2/4),respectively.There was a statistically significant difference in the constituent ratios among the three groups(P<0.05).MMR protein deficiency was positively correlated with Ig heavy chain expression pattern and MSI(r=0.41,P<0.05;r=0.48,P<0.05),but Ig heavy chain expression pattern was not correlated with MSI(r=0.02,P>0.05).Conclusion:Ig heavy chain CSR detection is helpful for the differential diagnosis of MALT lymphoma.Low frequency MMR protein deletion and MSI-H phenotype exist in MALT lymphoma,which may be of certain value for the study of its occurrence,development and clinical treatment.
5.Research progress on anatomical variations of the femoral vein and ultrasound-guided femoral vein catheterization
Feng LIU ; Xiu-qin YU ; Wang SHEN ; Bing TANG
Fudan University Journal of Medical Sciences 2025;52(5):733-736
The femoral vein is the primary venous trunk of the lower limbs and is commonly used for central venous catheterization in clinical practice.Traditional textbooks lack summarizes of the different types of anatomical variations of the femoral vein,making it more challenging for operators to perform punctures.Ultrasound-guided catheterization provides visualization,but there are still frequent instances of failed punctures and various complications.Operators usually use ultrasound equipment according to personal habits,but may not reach its full potential.This review summarizes recent researches on anatomical variations of the femoral vein and ultrasound-guided femoral vein catheterization,offering reference for medical professionals in clinical practice.
6.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.
7.Role of EBP50 in renal tubular epithelial-mesenchymal transition in diabetic nephropathy
Xiaofei XIU ; Xiaomei WANG ; Tao ZHANG ; Xuelan XIAO ; Hongjing SUN ; Zinan GUO ; Feng GAO
Journal of Chinese Physician 2025;27(5):678-681
Objective:To investigate the role of ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50) in renal tubular epithelial-mesenchymal transition (EMT) in diabetic nephropathy (DN).Methods:Renal tissue specimens from 24 DN patients (DN group) confirmed by medical history, clinical laboratory tests, and pathological diagnosis at the Third Hospital of Hebei Medical University and 15 adjacent normal renal tissues (control group) from 2018 to 2023 were collected. Immunohistochemical staining was performed to detect the expression of EBP50, E-cadherin, and Vimentin proteins. Additionally, 10 healthy volunteers were enrolled as a normal group, and fasting blood glucose, serum creatinine, blood urea nitrogen, and 24 h urinary protein levels were compared between DN patients and the normal group.Results:Fasting blood glucose, serum creatinine, blood urea nitrogen, and 24 h urinary protein levels were significantly higher in the DN group than in the normal group (all P<0.01). Periodic acid-schiff (PAS) staining revealed significant thickening of the glomerular basement membrane, increased extracellular matrix, vacuolar degeneration of renal tubules, and elevated extracellular matrix in the renal interstitium in the DN group. Immunohistochemistry showed higher expression of EBP50 and E-cadherin proteins in the control group than in the DN group (all P<0.01), while Vimentin expression was lower in the control group ( P<0.01). Conclusions:EBP50 is involved in the EMT process of renal tubules in DN and is associated with tubular injury.
8.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.
9.Mechanism of action of Sterculiae Lychnophorae Semen against PM2.5-induced acute lung injury based on network pharmacology,molecular docking and experimental validation
Fan ZHANG ; Yi-fan DU ; Xiao-shu DENG ; Zu-feng ZHANG ; Xian-lei HAN ; Wei TIAN ; Xiu-mei LI ; Mian CHEN ; Fei LIU ; Nan WANG
Chinese Pharmacological Bulletin 2025;41(12):2362-2369
Aim To investigate the anti-acute lung injury(ALI)effect of Sterculiae Lychnophorae Semen(SLS)and its mechanism.Methods The main ac-tive components of SLS and their core targets and path-ways of action against ALI were obtained by network pharmacology methods.Subsequently,molecular doc-king technology and in vitro cellular experiments were applied for validation.Results A total of 19 core tar-gets were obtained,including HSP90AA1,CASP3,TNF,MAPK8 and MAPK14.The mechanisms may in-volve signaling pathways such as cancer,PI3K/Akt and MAPK.Molecular docking confirmed that the key targets of SLS formed a better binding activity with the relevant active ingredients.The in vitro results showed that SLS was able to protect the PM2.5-contaminated BEAS-2B cells,inhibit their NO,IL-1β and TNF-αlevels,and reduce the expression of p-p38 MAPK and p-JNK proteins.Conclusions The study successfully predicts the active ingredients,targets and signaling pathways of SLS against ALI,and in vitro experiments demonstrate that SLS might protect BEAS-2B cells from PM2.5 stimulus-induced inflammation and apoptosis by inhibiting the over-activation of p38 MAPK and JNK signaling pathways.
10.Treating Type 2 Diabetic Nephropathy by Down-regulating NOX4 to Inhibit the Oxidative Stress Pathway in Mesenchymal Stem Cells
Shu-Qi FENG ; Guo-Rong JIN ; Qun-Hang XUE ; Min HE ; Ze-Hang WANG ; Jia-Xin YAO ; Long CHEN ; Yu-Jiao WANG ; An-Xiu ZHANG ; Sheng HE ; Bing-Rui ZHOU ; Jun XIE
Chinese Journal of Biochemistry and Molecular Biology 2025;41(5):730-740
Diabetic nephropathy(DN)is a serious complication of diabetes mellitus and a leading cause of end-stage renal diseases.In DN patients,key pathological mechanisms include proteinuria,glomerulo-sclerosis,and fibrosis,largely driven by poor glycemic control and oxidative stress caused by prolonged hyperglycemia.This stress damages renal podocytes and triggers inflammatory mesenchymal infiltration of renal tubular cells,exacerbating the progression of proteinuria and fibrosis.Human umbilical cord-de-rived mesenchymal stem cells(hUC-MSCs)offer promising potential for treating DN due to their strong anti-oxidative properties.In this study,we developed a DN mouse model and treated the mouse via tail vein injections of hUC-MSCs(1×106 cells/mouse).The results indicated that hUC-MSCs significantly lowered fasting blood glucose levels(22.5±3.0 vs 14.7±1.1,P<0.01)and improved glucose toler-ance,as shown by intraperitoneal glucose tolerance test(IPGTT)results(P<0.05).Additionally,the renal function improved in hUC-MSCs-treated mice,with marked reductions in oxidative stress markers,including blood urea nitrogen(BUN),urinary creatinine(Ucr),urinary protein(PRO),superoxide dismutase(SOD),and malondialdehyde(MDA)(P<0.05).Histological analyses through hematoxy-lin-eosin(H&E),Periodic Acid-Schiff(PAS),and Sirius red staining demonstrated alleviation of glo-merular mesangial hyperplasia,glomerular hypertrophy,and tubular inflammation.Furthermore,hUC-MSCs treatment downregulated the expression of oxidative stress-related proteins,such as NADPH oxi-dase 4(NOX4)and thioredoxin-interacting protein(TXNIP),and reduced reactive oxygen species(ROS)production(P<0.05).Meanwhile,human renal cortical proximal tubule epithelial cells(HK-2 cells)were selected for validation in vitro experiments using high glucose treatment followed by super-natants of hUC-MSCs(MSC-CM),and Western blotting showed that the expression of both NOX4 and TXNIP was inhibited(P<0.05)and ROS expression was reduced.In conclusion,hUC-MSC treatment effectively lowered blood glucose levels and improved renal function in DN mice,likely through the sup-pression of NOX4 expression and TXNIP-mediated oxidative stress.

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