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.

Objective To explore the effects of different glucose concentrations on the synthesis and secretion of bone collagen in osteoblasts and the impact of diabetes on bone quality in mice.Methods(1)Primary osteoblasts were extracted from the skulls of neonatal mice via collagenase digestion and cultured in four groups under different glucose concentrations:normal glucose(5.5 mmol/L),moderate glucose(11.5 mmol/L),moderate-high glucose(16.5 mmol/L),and high glucose(25 mmol/L).EdU staining was performed to evaluate cell proliferation,while the Transwell assay was used to assess cell migration.Immunofluorescence and Western blotting were performed to detect and quantitatively analyze the content of type Ⅰ collagen(Col-1).Alizarin red S(ARS)staining and alkaline phosphatase(ALP)staining were applied to assess the effects of different glucose concentrations on osteogenic differentiation.(2)Six-week-old male C57BL/6 mice were randomly divided into control group and model group(5 in each group).The model group was fed a high-fat diet for 4 weeks followed by streptozotocin(STZ)injection to establish a diabetic mouse model.The osteogenic differentiation capacity of primary osteoblasts from both groups was assessed.(3)Micro-computed tomography(Micro-CT)was employed to analyze femoral bone mineral density(BMD),bone volume/tissue volume(BV/TV),trabecular number(Tb.N),and trabecular separation(Tb.Sp).Three-point bending test was conducted to evaluate mechanical parameters including maximum load,Young's modulus,fracture energy,and stiffness.RT-qPCR was employed to assess the expression of osteogenic differentiation genes(Alp,Opn,Col1a1,and Lox).Masson staining and Mallory staining were used to evaluate Col-1 content in trabecular bone.Results(1)EdU and Transwell assay results demonstrated that with the gradual increase in glucose concentration,the proliferation and migration abilities of osteoblasts were significantly decreased(P<0.001),and the protein expression levels of Col-1 and lysyl oxidase(LOX)were significantly reduced(P<0.01 or P<0.001).ARS and ALP staining revealed that calcium salt deposition and ALP activity in osteoblasts were significantly decreased with increasing glucose concentration(P<0.05 or P<0.001).(2)Compared with control group,mice in model group exhibited typical"three polies and one weight loss"symptoms(polyuria,polydipsia,polyphagia,and weight loss)of diabetes,and ARS and ALP staining showed a significant reduction in osteoblasts(P<0.001).(3)Micro-CT and three-point bending test results indicated that,compared with control group,mice in model group showed microarchitectural deterioration of bone,decreased Tb.N,increased Tb.Sp,and significantly reduced maximum load,Young's modulus,fracture energy,and stiffness(P<0.05).RT-qPCR results showed that the relative mRNA expression levels of osteogenic differentiation genes(Alp,Opn,Col1a1,and Lox)were significantly decreased in model group compared with control group(P<0.01 or P<0.001).Masson and Mallory staining indicated a significant reduction in collagen content in model group compared with control group(P<0.01).Conclusions High-glucose environment inhibits osteoblast proliferation,differentiation,and migration.Diabetic mice exhibit reduced bone quality and increased bone fragility,potentially mediated by decreased lysyl oxidase and collagen levels.

Objective To analyze the relationship between obesity indicators,muscle mass indices and hypertension in Dongxiang adults,and establish and evaluate a Nomogram model based on these indicators used to predict the risk of hypertension in this population.Methods A total of 1209 Dongxiang adults from Linxia Prefecture,Gansu Province were selected,11 obesity indicators and 5 muscle mass indicators,including neck circumference(NC),waist-to-hip ratio(WHR),BMI,ponderal index(PI),conicity index(CI),a body shape index(ABSI),body roundness index(BRI),abdominal volume index(AVI),hip index(HI),body adiposity index(BAI),and the ratio of limb fat mass to body weight(LFWR),appendicular skeletal muscle mass(ASM),appendicular skeletal muscle mass index(ASMI),appendicular skeletal muscle mass to BMI ratio(ASMBMI),skeletal muscle index(SMI),and trunk muscle mass to body weight ratio(TMWR)were measured.Logistic regression analysis was used to explore the relationship between each indicator and hypertension.Nomogram prediction model was constructed and validated by using R language.Results Among Dongxiang males,the NC,BMI,PI,WHR,CI,AVI,BRI,BAI,ASM,ASMI,and LFWR were lower in the normal and high-normal blood pressure groups compared to the hypertensive group,while SMI,ASMBMI,and TMWR were higher.Among females,similar trends were observed,with lower NC,BMI,PI,WHR,CI,AVI,BRI,BAI,and LFWR in the normal blood pressure and high-normal blood pressure groups compared to the hypertensive group,but SMI,ASMBMI,and TMWR higher than the hypertensive group(P＜0.05).Results of multivariate Logistic regression analysis indicated that age,NC,and WHR were risk factors for hypertension in Dongxiang adults,while was protective factor(P＜0.05).The area under curve(AUC)of the Nomogram model constructed based on these factors was 0.796,and the Bootstrap internal validation C-index was 0.7957,indicating good calibration of the model.Conclusion The Nomogram model constructed based on obesity and muscle mass indicators has good predictive efficiency for predicting the risk of hypertension in Dongxiang adults.

Objective To construct a three-dimensional bionic model of intestinal mucosal structure in vitro.Methods Using fibroin protein with villous-crypt structure as scaffold and Caco-2 and HT29-MTX-E12 as seed cells,the intestinal mucosal epithelial-myofibroblast co-culture model was constructed by three-dimensional co-culture with myofibroblasts in vitro.The growth,activity,histological characteristics and expression of functional genes of model cells were investigated through the detection of cell signature proteins and genes.Results 1.An intestinal mucosal epithelial-myofibroblast co-culture model was successfully constructed with good cell activity.2.Mucous secretion increased and muc2 gene expression was up-regulated in the co-culture model.Conclusion The co-culture of intestinal mucosal epithelial-myofibroblasts with villous-crypt structure can promote the functional differentiation of intestinal epithelial cells and better simulate the structure and function of intestinal mucosa in vivo.

Objective To investigate the size variation in the first metatarsal of extant primates.Methods In this study,we analyzed 135 first metatarsal specimens across 12 primate genera,quantifying eight linear measurements,articular surface areas,mid-shaft cross-sectional area,total surface area,volume,and derived indices.Multivariate patterns were assessed through mean-based correspondence analysis and principal component analysis(PCA).Results Eulemur,Otolemur,Cebus,and Perodicticus exhibited a relatively high metatarsal surface-area-to-volume ratio.Perodicticus additionally showed a low articular facet index.Propithecus,Colobus,and Macaca displayed lower values for metatarsal shaft robusticity,the ratio of shaft cross-sectional area to base articular surface area,and the proximal articular facet index.Nasalis possessed a relatively high articular facet index.Pongo,Pan,Gorilla,and Homo sapiens were characterized by higher metatarsal shaft robusticity and a lower metatarsal surface-area-to-volume ratio.Principal component analysis revealed that the 12 extant primate genera could be broadly divided into two groups.Group 1 comprised Pongo,Pan,Gorilla and H.sapiens,although H.sapiens formed a distinct cluster relative to the extant great apes.Group 2 included Eulemur,Otolemur,Perodicticus,Propithecus,Cebus,Colobus,Macaca and Nasalis.Conclusion The relative sizedistribution of the first metatarsal provides some reference value for classifying extant primates.However,it demonstrates no clear correlations with specific locomotor patterns or foot grasping ability.

By summarizing the mass spectrometric fragmentation patterns of oxyphenisatin substances,an analytical method was established for screening of illegally added oxyphenisatin compounds in weight-loss health foods using high performance liquid chromatography-in-source-fragmentation-quadrupole time-of-flight mass spectrometry(HPLC-ISF-QTOF-MS),along with a quantitative method for 11 kinds of oxyphenisatin compounds.Based on the developed screening method,an oxyphenisatin derivative was discovered in the reference standards,which was tentatively identified as 4-(3-(4-hydroxyphenyl)-2-oxoindolin-3-yl)phenyl acetate and confirmed by MS/MS analysis.The results showed that all 11 kinds of oxyphenisatin compounds had correlation coefficients greater than 0.9971,with limits of detection(LODs)ranging from 0.12 to 0.68 μg/L and limits of quantification(LOQ)from 0.21 to 2.29 μg/L.The LODs for 11 kinds of characteristic ions ranged from 0.45 to 9.11 μg/kg.At spiking levels of 25,50 and 100 μg/kg,the recoveries ranged from 78.9%to 117.3%.The instrumental precision,intra-day method precision and inter-day method precision were 0.23%?1.70%,0.7%?2.4%,and 1.1%?3.3%,respectively.The developed targeted and non-targeted detection method demonstrated high sensitivity,strong stability,rapid analysis,and an expanded screening range for oxyphenisatin substances,and provided robust technical support for regulatory authorities in combating illegal adulteration.

OBJECTIVE: To investigate the short-term effectiveness of the anterior and middle columns in thoracolumbar tuberculosis reconstructed with whole autogenous spinous process-laminar bone through posterior approach. METHODS: The retrospective study included 78 patients with thoracolumbar tuberculosis who underwent posterior approach surgery and anterior and middle column bone graft reconstruction between January 2012 and May 2023. Based on the type of autogenous bone graft used, patients were divided into group A (whole autogenous spinous process-laminar bone graft, 38 cases) and group B (autogenous structural iliac bone graft, 40 cases). There was no significant difference of baseline data, such as age, gender, disease duration, involved segment of spinal tuberculosis, and preoperative erythrocyte sedimentation rate (ESR), C reactive protein (CRP), Oswestry disability index (ODI), visual analogue scale (VAS) score, the American Spinal Injury Association (ASIA) grade, segmental kyphotic angle, and intervertebral height between the two groups ( P>0.05). The operation time, intraoperative blood loss, postoperative drainage, hospital stays, ESR, CRP, VAS score, ODI, bone fusion time, ASIA grade for neurological status valuation, postoperative complications, change of segmental kyphotic angle, change of intervertebral height were recorded and compared between the two groups. RESULTS: The operation time in group A was significantly shorter than that in group B ( P<0.05); there was no significant difference in intraoperative blood loss, postoperative drainage, and hospital stays between the two groups ( P>0.05). All patients in the two groups were followed up 14-110 months (mean, 64.1 months); there was no significant difference in the follow-up time between the two groups ( P>0.05). The ESR, CRP, ODI, and VAS score at each time point after operation in both groups significantly improved when compared with those before operation, and further improved with the extension of time, the differences were significant ( P<0.05). There was no significant difference between the two groups ( P>0.05) except that the VAS score of group A was significantly better than that of group B at 3 days after operation ( P<0.05). There was no significant difference in fusion time between the two groups ( P>0.05). The neurological function of most patients improved after operation, and there was no significant difference in ASIA grade between the two groups at last follow-up ( P>0.05). There was no significant difference in segmental kyphosis angle and intervertebral height between the two groups at each time point ( P>0.05), and no significant difference in segmental kyphosis angle, intervertebral height correction and loss were found between the two groups ( P>0.05). In group A, there was 1 case of incision fat liquefaction and 1 case of incision infection; in group B, there was 1 case of deep venous thrombosis, 2 cases of pleural effusion, and 10 cases of pain in bone harvesting area; in both groups, there were 2 cases of gout caused by hyperuricemia. There was a significant difference in the incidence of pain in bone harvesting area between the two groups ( P<0.05), and there was no significant difference in the incidence of other complications between the two groups ( P>0.05). CONCLUSION Whole autogenous spinous process-laminar bone grafting is equivalent to structural iliac bone graft in reconstruction of the anterior and middle columns in thoracolumbar tuberculosis through posterior approach, effectively supporting the stability of the anterior and middle columns of the spine, while resulting in shorter operation time and less postoperative pain in bone harvesting area.
Humans ; Tuberculosis, Spinal/surgery* ; Thoracic Vertebrae/surgery* ; Lumbar Vertebrae/surgery* ; Bone Transplantation/methods* ; Retrospective Studies ; Male ; Female ; Treatment Outcome ; Plastic Surgery Procedures/methods* ; Adult ; Middle Aged ; Transplantation, Autologous ; Operative Time ; Ilium/transplantation*

OBJECTIVE: To explore short-term effectiveness of floating island laminectomy surgery in treating thoracic spinal stenosis and myelopathy caused by ossification of the ligamentum flavum. METHODS: A total of 31 patients with thoracic spinal stenosis and myelopathy caused by ossification of the ligamentum flavum between January 2019 and April 2022 were managed with floating island laminectomy surgery. The patients comprised 17 males and 14 females, aged between 36 and 78 years, with an average of 55.9 years. The duration of symptoms of spinal cord compression ranged from 3 to 62 months (mean, 27.2 months). The lesions affected T _1-6 in 4 cases and T _7-12 in 27 cases. The preoperative neurological function score from the modified Japanese Orthopaedic Association (mJOA) was 4.7±0.6. Surgical duration, intraoperative blood loss, and complications were recorded. The thoracic MRI was conducted to reassess the degree of spinal cord compression and decompression after operation. The mJOA score was employed to evaluate the neurological function and calculate the recovery rate at 12 months after operation. RESULTS: The surgical duration ranged from 122 to 325 minutes, with an average of 204.5 minutes. The intraoperative blood loss ranged from 150 to 800 mL (mean, 404.8 mL). All incisions healed by first intention after operation. All patients were followed up 12-14 months, with an average of 12.5 months. The patients' symptoms, including lower limb weakness, gait disorders, and pain, significantly improved. The mJOA scores after operation significantly increased when compared with preoperative scores ( P<0.05), gradually improving with time, with significant differences observed among 1, 3, and 6 months ( P<0.05). The recovery rate at 12 months was 69.76%±11.38%, with 10 cases exhibiting excellent neurological function and 21 cases showing good. During the procedure, there were 3 cases of dural tear and 1 case of dural defect. Postoperatively, there were 2 cases of cerebrospinal fluid leakage. No aggravated nerve damage, recurrence of ligamentum flavum ossification, or postoperative thoracic deformity occurred. CONCLUSION The floating island laminectomy surgery is safe for treating thoracic spinal stenosis and myelopathy caused by ossification of the ligamentum flavum, effectively preventing the exacerbation of neurological symptoms. Early improvement and recovery of neurological function are achieved.
Humans ; Male ; Spinal Stenosis/diagnostic imaging* ; Female ; Laminectomy/methods* ; Ligamentum Flavum/pathology* ; Middle Aged ; Aged ; Thoracic Vertebrae/surgery* ; Adult ; Decompression, Surgical/methods* ; Treatment Outcome ; Ossification, Heterotopic/surgery* ; Spinal Cord Compression/etiology* ; Spinal Cord Diseases/etiology* ; Magnetic Resonance Imaging

OBJECTIVE: Photodynamic therapy has become an important method in clinical tumor treatment. This study aimed to investigate the effects of hematoporphyrin on multiple myeloma (MM) and its potential applications. METHODS: The MM cell line RPMI 8226 was treated with hematoporphyrin derivative (HPD), and CCK-8 assay was used to determine cell viability, apoptosis was detected by flow cytometry, intracellular reactive oxygen species (ROS) levels were measured using a detection kit combined with flow cytometry, and Western blot assay was used to detect apoptosis-related proteins and key signaling pathway protein levels. RESULTS: The optimal incubation time for the maximum absorption of HPD in RPMI 8226 cells was 4 hours. HPD significantly inhibited the proliferation of RPMI 8226 cells in a dose- and illumination time-dependent manner ( r =0.981; r =0.961). Additionally, HPD induced apoptosis in RPMI 8226 cells, but had no significant inhibitory effect on peripheral blood mononuclear cells derived from healthy individuals. HPD combined with illumination treatment significantly increased the intracellular ROS level, upregulated the expression of apoptosis-related proteins such as cleaved PARP, cleaved caspase-3 and Bax, and down-regulated the expression of proteins that maintain cell survival, such as NF-κB and Akt. CONCLUSION The HPD can inhibit the proliferation and induce apoptosis of multiple myeloma cells.
Humans ; Multiple Myeloma/pathology* ; Hematoporphyrins/pharmacology* ; Apoptosis/drug effects* ; Cell Line, Tumor ; Reactive Oxygen Species/metabolism* ; Cell Proliferation/drug effects* ; Photochemotherapy ; Cell Survival/drug effects* ; Signal Transduction