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.

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.

BACKGROUND:Allogeneic hematopoietic stem cell transplantation is currently the most effective method for the radical treatment of thalassemia major,but only half of patients can find compatible bone marrow or peripheral blood stem cells.Sib-derived umbilical cord blood stem cells have different characteristics from bone marrow and peripheral blood stem cells,and are a potential alternative source of hematopoietic stem cells for transplantation in patients with thalassemia major.OBJECTIVE:To investigate the therapeutic effect of human leukocyte antigen matched sibling fresh umbilical cord blood transplantation in the treatment of β-thalassemia major in children.METHODS:Forty-eight children with β-thalassemia major,including 28 males and 20 females,with a median age of 4 years old,were selected from Nanfang Hospital of Southern Medical University from June 2010 to June 2020.All of them received fresh cord blood transplantation from human leukocyte antigen matched sibling.Transplantation conditioning adopted a myeloablative regiment without anti-thymocyte globulin.A combination of cyclosporine A and mycophenolate mofetil with or without short-range methotrexate was administered for graft-versus-host disease.RESULTS AND CONCLUSION:(1)The median infused doses of total nucleated cells and CD34+cells were 8.17×107/kg and 2.40×105/kg,respectively in 48 children.The median follow-up time after cord blood transplantation was 98 months,and 44 cases were successfully engrafted.The median time to neutrophil and platelet engraftment was 28 and 31 days,respectively.Among them,37 cases were found to be donor-type complete chimerism detected as evidence of implantation after transplantation,7 cases were found to be stable mixed chimerism.(2)Among the 44 children with successful implantation,four patients developed acute graft-versus-host disease,and were scored as grade Ⅰ(n=2)and grade Ⅱ(n=2).All the affected organs were skin,and no chronic graft-versus-host disease occurred.(3)After umbilical cord blood transplantation,cytomegalovirus infection and activation occurred in 5 of the 48 cases,sepsis in 12 cases,invasive fungal disease in 3 cases,stomatitis in 21 cases,hemorrhagic cystitis in 8 cases,and hepatic vein occlusion in 1 case.(4)Among 48 children,47 patients survived;1 died of severe pneumonia combined with acute heart failure 28 days after transplantation;43 survived without disease;3 had primary implantation failure,and 1 had pancytopenia after transplantation.The 5-year probabilities of overall survival and disease-free survival were 98％and 89％,respectively.The cumulative incidence of transplant-related deaths at 1 year was 2.1％.(5)The above results indicate that human leukocyte antigen matched sibling fresh umbilical cord blood transplantation is effective in the treatment of β-thalassemia major in children with a low incidence of graft-versus-host disease.

BACKGROUND:Allogeneic hematopoietic stem cell transplantation is currently the most effective method for the radical treatment of thalassemia major,but only half of patients can find compatible bone marrow or peripheral blood stem cells.Sib-derived umbilical cord blood stem cells have different characteristics from bone marrow and peripheral blood stem cells,and are a potential alternative source of hematopoietic stem cells for transplantation in patients with thalassemia major.OBJECTIVE:To investigate the therapeutic effect of human leukocyte antigen matched sibling fresh umbilical cord blood transplantation in the treatment of β-thalassemia major in children.METHODS:Forty-eight children with β-thalassemia major,including 28 males and 20 females,with a median age of 4 years old,were selected from Nanfang Hospital of Southern Medical University from June 2010 to June 2020.All of them received fresh cord blood transplantation from human leukocyte antigen matched sibling.Transplantation conditioning adopted a myeloablative regiment without anti-thymocyte globulin.A combination of cyclosporine A and mycophenolate mofetil with or without short-range methotrexate was administered for graft-versus-host disease.RESULTS AND CONCLUSION:(1)The median infused doses of total nucleated cells and CD34+cells were 8.17×107/kg and 2.40×105/kg,respectively in 48 children.The median follow-up time after cord blood transplantation was 98 months,and 44 cases were successfully engrafted.The median time to neutrophil and platelet engraftment was 28 and 31 days,respectively.Among them,37 cases were found to be donor-type complete chimerism detected as evidence of implantation after transplantation,7 cases were found to be stable mixed chimerism.(2)Among the 44 children with successful implantation,four patients developed acute graft-versus-host disease,and were scored as grade Ⅰ(n=2)and grade Ⅱ(n=2).All the affected organs were skin,and no chronic graft-versus-host disease occurred.(3)After umbilical cord blood transplantation,cytomegalovirus infection and activation occurred in 5 of the 48 cases,sepsis in 12 cases,invasive fungal disease in 3 cases,stomatitis in 21 cases,hemorrhagic cystitis in 8 cases,and hepatic vein occlusion in 1 case.(4)Among 48 children,47 patients survived;1 died of severe pneumonia combined with acute heart failure 28 days after transplantation;43 survived without disease;3 had primary implantation failure,and 1 had pancytopenia after transplantation.The 5-year probabilities of overall survival and disease-free survival were 98％and 89％,respectively.The cumulative incidence of transplant-related deaths at 1 year was 2.1％.(5)The above results indicate that human leukocyte antigen matched sibling fresh umbilical cord blood transplantation is effective in the treatment of β-thalassemia major in children with a low incidence of graft-versus-host disease.

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.

This study investigated the prevalence of canine ticks and the types of their carried pathogens in select cities of Liaon-ing Province,to provide a theoretical scientific basis for the prevention and control of ticks and tick-borne diseases.Canine ticks were collected from six cities in Liaoning Province(Shenyang,Dalian,Anshan,Chaoyang,Tieling,Dandong)and identified through a combination of morphological and molecular biology methods.PCR was used to detect five tick pathogens:Rickettsia,Borrelia burgdor-feri,Babesia,Pseudomonas aeruginosa,and Ehrlichia.Canine ticks were prevalent primarily in Liaoning Province from April to June.The collected ticks included 456 Haemaphysalis longicornis,70 Ixodes persulcatus,and 31 Rhicephalus sanguineus.Three tick borne pathogens,Ehrlichia,Borrelia burgdorferi,and Rickettsia,were detected,whereas no Babesia or Pseudomonas were detected.The to-tal detection rate of Ehrlichia(46.85%),which is significant difference with total detection rate of Borrelia burgdorferi(10.81%)(χ2=33.392,P<0.05),but insignificant difference with total detection rate of Rickettsia(34.23%)(χ2=3.370,P>0.05),Both Eh-rlichia and Rickettsia were distributed in the six cities.Haemaphysalis longicornis was the dominant tick species parasite on the surfaces of dogs in Liaoning Province.The main tick borne pathogens in dogs in Liaoning Province were Ehrlichia and Rickettsia.

This study investigated the prevalence of canine ticks and the types of their carried pathogens in select cities of Liaon-ing Province,to provide a theoretical scientific basis for the prevention and control of ticks and tick-borne diseases.Canine ticks were collected from six cities in Liaoning Province(Shenyang,Dalian,Anshan,Chaoyang,Tieling,Dandong)and identified through a combination of morphological and molecular biology methods.PCR was used to detect five tick pathogens:Rickettsia,Borrelia burgdor-feri,Babesia,Pseudomonas aeruginosa,and Ehrlichia.Canine ticks were prevalent primarily in Liaoning Province from April to June.The collected ticks included 456 Haemaphysalis longicornis,70 Ixodes persulcatus,and 31 Rhicephalus sanguineus.Three tick borne pathogens,Ehrlichia,Borrelia burgdorferi,and Rickettsia,were detected,whereas no Babesia or Pseudomonas were detected.The to-tal detection rate of Ehrlichia(46.85%),which is significant difference with total detection rate of Borrelia burgdorferi(10.81%)(χ2=33.392,P<0.05),but insignificant difference with total detection rate of Rickettsia(34.23%)(χ2=3.370,P>0.05),Both Eh-rlichia and Rickettsia were distributed in the six cities.Haemaphysalis longicornis was the dominant tick species parasite on the surfaces of dogs in Liaoning Province.The main tick borne pathogens in dogs in Liaoning Province were Ehrlichia and Rickettsia.

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.

This study employs ultra-performance liquid chromatography(UPLC) to analyze the differences in alkaloid content of Commelina communis from various geographical origins, exploring its feasibility as a quality evaluation indicator. A total of 57 batches of C. communis samples from 23 provinces, autonomous regions, and municipalities in China were selected. The MicroPulite HSS T3(2.1 mm×50 mm, 1.8 μm)column was used with a mobile phase of acetonitrile-0.2% phosphoric acid aqueous solution(20∶80), detection wavelength at 254 nm, and a flow rate of 0.3 mL·min~(-1) to measure the content of 1-deoxynojirimycin(DNJ) and deoxymannojirimycin(DMJ). The MicroPulite XP tC_(18)(2.1 mm×100 mm, 1.7 μm)column was employed with a mobile phase of acetonitrile-0.2% phosphoric acid aqueous solution(4∶96), detection wavelength at 254 nm, and a flow rate of 0.4 mL·min~(-1) to measure the content of norharmine(NHM) and harmanme(HM). Chemometric methods were applied to study the relationships and differences among the 57 batches of C. communis. Significant differences in alkaloid content were observed among C. communis from different regions, with the average total content decreasing in the order of North China, Northeast China, Northwest China, East China, Southwest China, Central China, and South China. Cluster analysis(CA) and principal component analysis(PCA) further revealed the quality differences of C. communis from various origins, and partial least squares discriminant analysis(PLS-DA) identified DNJ as a marker compound to distinguish the quality differences between different geographical sources of C. communis. It is recommended that the content limit of DNJ be set at no less than 0.055 9%, providing a reference for the quality evaluation and clinical application of C. communis medicinal materials.
Alkaloids/analysis* ; Drugs, Chinese Herbal/chemistry* ; China ; Chromatography, High Pressure Liquid ; Chemometrics/methods* ; Quality Control

This study was aimed at predicting the biological function of Streptococcus suis serotype 2(S.suis 2)tyrosine kinase Cps2C through bioinformatics and analyzing its effects on S.suis 2 pathogenicity.Online bioinformatics tools were used to analyze and predict the localization,conserved domains,transmembrane domains,protein similarity,and protein three-di-mensional structure of Cps2C.A BALB/c mouse infection model was used to compare and analyze clinical characteristics,mor-tality rates,and blood bacterial loads in mice infected with the wild-type strain 05ZYH33 and the cps2C gene knockout strainΔcps2C.Additionally,heart,brain,and joint tissue sections from infected mice were stained with hematoxylin and eosin(HE)for comparative pathological analysis.The Cps2C protein-coding gene is located upstream of the capsule biosynthesis locus cps,lacks transmembrane domains,is a homologous protein to Streptococcus pneumoniae tyrosine kinase CpsD with a 64％amino acid sequence similarity,and is potentially involved in bacterial capsule synthesis regulation.Cps2C deficiency significantly de-creased the pathogenicity of S.suis 2 in mice(P＜0.05).Compared with the wild-type strain,the Δcps2C strain showed a sig-nificantly lower blood bacterial load(P＜0.000 1).Heart,brain,and joint tissues of mice infected intraperitoneally with strains 05ZYH33 and Δcps2C remained structurally intact without e-dema,hemorrhage,or inflammatory cell infiltration;moreo-ver,characteristic lesion features of endocarditis,meningitis,or arthritis were absent.Streptococcus suis serotype 2 tyrosine kinase Cps2C may be an important regulatory factor in capsule biosynthesis,and its deficiency decreases bacterial blood survival capability and pathogenicity in mice.