1.The Clinical and Genetics Characteristics of Oculopharyngodistal Myopathy
Jiaxi YU ; Zhihao QUAN ; Yilei ZHENG ; Jing AN ; Jing LIU ; Qingqing WANG ; Lingchao MENG ; Meng YU ; Zhiying XIE ; Jianwen DENG ; He LYU ; Wei ZHANG ; Yun YUAN ; Zhaoxia WANG
JOURNAL OF RARE DISEASES 2026;5(2):164-174
To analyze the clinical and genetic features of oculopharyngodistal myopathy (OPDM) patients and compare the phenotypic differences among various causative genes. A total of 65 genetically confirmed OPDM patients from 43 unrelated families, who were admitted to the Department of Neurology, Peking University First Hospital between January 2008 and December 2025, were retrospectively included.The general demographic data, clinical manifestations, laboratory/auxiliary examinations, muscle pathology, and genetic test results were systematically collected and analyzed. The clinical and pathological characteristics among different OPDM subtypes were compared. Among the 65 patients(39 male and 26 female), the mean age of onset was (31.20±10.43) years (range: 14 to 63 years). The initial symptom was predominantly distal limb weakness (67.44%), which gradually progressed to involve the extraocular muscles, pharyngeal muscles, facial muscles and proximal limb muscles. Serum creatine kinase levels were mildly to moderately elevated. Muscle pathological examinations revealed rimmed vacuoles and intranuclear inclusions (within muscle fibers). The mean duration from onset to diagnosis was (12.33±7.88) years (range: 1 to 32 years). All probands had negative results on conventional next-generation whole-exome sequencing; pathogenic variants were identified through third-generation long-read sequencing or OPDM-targeted repeat-primed polymerase chain reaction(RP-PCR). Among the 43 families, OPDM2 subtype was the most common genetic subtype ( OPDM2 was the predominant subtype in this study. All subtypes share similar age of onset and muscular pathological changes, yet exhibit distinct disease progression patterns. Future multicenter prospective cohort studies are warranted to further elucidate the clinical characteristics, pathogenetic mechanisms, and prognostic differences among OPDM subtypes.
2.Neuroelectromagnetic Activities Across Temporal Scales
Zhuo-Qun SHEN ; Xiao-Fei XU ; Yan-Qing WANG ; Jing-Xin LI ; Lan TIAN ; Wei GUO ; Jing-Jing XU
Progress in Biochemistry and Biophysics 2026;53(6):1541-1560
Although global brain science research has progressed rapidly in recent decades, several fundamental questions in neuroscience remain unresolved. In particular, the physical mechanism underlying neural signal transmission remains controversial, and the carriers responsible for neural information storage and retrieval have not yet been fully clarified. These unresolved issues motivate us to re-examine the processes of neural information generation, transmission, integration, storage, and retrieval from multiple perspectives. A key observation is that neural electromagnetic activities are closely associated with time. Their duration, temporal structure, and dynamic evolution play crucial roles in neural information processing. In this work, we analyze neural electromagnetic activities from the perspective of temporal scales (referred to here as the “time course”). By reviewing and integrating findings from previous studies, we examine the characteristic time requirements and dynamic features of neural processes occurring at different stages of information processing. These stages include neural signal generation, signal transmission along axons, synaptic integration, synaptic plasticity, and memory formation and retrieval. Based on this temporal analysis, we outline a framework describing neural electromagnetic activities across a wide range of time scales, spanning from microseconds to minutes, hours, or even longer periods associated with long-term memory, which suggests that neural information processing involves multiple physical processes operating at different time levels. Rapid electromagnetic events may occur on microsecond scales, whereas electrophysiological phenomena such as action potentials typically last on the order of milliseconds. Longer time scales are associated with synaptic plasticity and memory-related processes. From this perspective, we propose that the physical carrier of neural information may be transient electromagnetic pulses with durations on the microsecond scale. In this framework, action potentials can be interpreted as the macroscopic electrophysiological manifestation of underlying electromagnetic processes triggered by ionic currents across neuronal membranes. Rather than being the fundamental neural signal itself, the action potential may represent a measurable membrane-level response associated with the successful activation of these electromagnetic events. Moreover, we discuss a possible mechanism for long-term memory storage. Considering the apparent temporal contradiction between the millisecond-scale excitation of neurons and the long-term persistence of memories, we believe that long-term memory information may be stored within neural network topologies formed by electrical synapse coupling. Such structures, referred to as electrically coupled memory networks (ECMNs), may enable neurons within the same network to respond rapidly and synchronously to stimuli, thereby facilitating efficient memory retrieval. Overall, this study emphasizes the importance of considering the temporal organization of neural electromagnetic activities when interpreting neural signaling mechanisms. It may provide new insights into the physical nature of neural information carriers and the mechanisms of memory storage and retrieval. Furthermore, highlighting the potential role of electromagnetic interactions in neural activity may contribute to the development of new theoretical frameworks and experimental approaches in neuroscience. Such perspectives may also offer valuable references for future research on neural coding, brain function mechanisms, and neuromodulation technologies.
3.Relationship between EDNRA gene polymorphisms and congenital bilateral absence of the vas deferens in the male Han Chinese population
Yuwan PENG ; Xiaojin HE ; Xiaoyu YANG ; Jing WANG ; Binbin WANG ; Dongdong TANG ; Zhaolian WEI ; Yunxia CAO
Acta Universitatis Medicinalis Anhui 2026;61(5):931-936
ObjectiveTo investigate the association between endothelin receptor type A gene (EDNRA) and congenital bilateral absence of the vas deferens (CBAVD). MethodsThis case-control study consisted of 124 subjects with CBAVD and 100 fertile controls.Two single nucleotide polymorphisms (SNPs: rs5335 and rs1801708) in the EDNRA gene were genotyped via PCR, PCR-RFLP analysis, and direct sequencing. ResultsNo significant differences existed between EDNRA polymorphisms and CBAVD phenotype (rs1801708: P=0.220 2, 0.163 2; rs5335: P=0.805 8, 0.818 6). However, the rs1801708-rs5335 haplotype AG was notably associated with an increased risk of CBAVD (P=0.008 6, OR=2.178, 95% CI: 1.207-3.929). A significantly protective effect of rs1801708-rs5335 haplotype GG on CBAVD (P=0.038 5, OR= 0.671, 95% CI: 0.460-0.980) was observed. After Bonferroni correction, the result for haplotype A-G remained significant (P =0.008 6<0.012 5), while haplotype G-G was not significant. ConclusionThe rs1801708-rs5335 AG haplotype of EDNRA is a potential risk factor for CBAVD development in Han Chinese.
4.A preliminary investigation on the carriage of Bartonella by rodents at key ports in western Inner Mongolia
Ruo-wen GUO ; Huai-bo WEI ; Peng LUO ; Xia LIU ; Zong-di LIU ; Jing WU ; Jia XU
Acta Parasitologica et Medica Entomologica Sinica 2026;33(2):134-140
Objective This study investigated the diversity of rodent populations and the infection status of Bartonella at three ports along the China-Mongolia border in 2022. Methods Rodents at three Belt and Road ports along the China-Mongolia border, namely Ganqimaodu, Erenhot, and Zhuengadabuqi, were morphologically identified. The Bartonella citrate synthase(gltA)gene was amplified by nested polymerase chain reaction(PCR), and PCR-positive products were sequenced. The resulting sequences were then analyzed for genetic characteristics. Phylogenetic analysis was performed using MEGA 11.0 software using Neighbor-Joining and Maximum-Likelihood method. Results A total of 94 rodents were captured, representing seven species from five families and six genera: Mus musculus, Meriones unguiculatus, Meriones meridianus, Spermophilus dauricus, Allactaga sibirica, Dipus sagitta, and Phodopus roborovskii. Among them, M. unguiculatus was the most abundant species, with 58 rodents, accounting for 61.70% of the total. Overall,11 positive Bartonella pathogen sequences were obtained from the three ports, with a positive detection rate of 11.70%(11/94). The infected rodent species included M. unguiculatus, M. meridianus, and A. sibirica, and two species of Bartonella were detected. Conclusions Rodents at Ganqimaodu, Erenhot, and Zhuengadabuqi ports along the China-Mongolia border were naturally infected with Bartonella. Rodent monitoring and pathogen prevention and control in this area should be strengthened.
5.Dual Targeting of TBK1 and JAK-STAT1 Pathways by (-)-epigallocatechin-3-gallate Suppresses Type I Interferon-driven Inflammation
Liang LI ; Qi-Huan SHENG ; Huan LIU ; Wen-Hao YANG ; Jia-Lin SHI ; Ying-Jie SUN ; Rui JING ; Wei-Hua MAI ; Zhi-Min LI ; Xiao-Li XIE
Progress in Biochemistry and Biophysics 2026;53(7):1969-1983
ObjectiveType I interferon (IFN-I) signaling is essential for antiviral innate immunity, yet its sustained or excessive activation contributes to the pathogenesis of several autoimmune diseases and interferonopathies, such as systemic lupus erythematosus and Aicardi-Goutières syndrome. Current strategies targeting this pathway, exemplified by JAK inhibitors, act mainly on downstream signal transduction and provide limited direct control over upstream IFN-I production, while also carrying the risk of broad immunosuppression. Phyllanthus emblica L. has long been used in traditional medicine for inflammatory disorders, but the bioactive constituent responsible for its regulation of IFN-I signaling and the underlying molecular mechanism have not been clearly defined. This study aimed to identify the active anti-inflammatory component of P. emblica and to characterize its mechanism of action on the IFN-I pathway in macrophages. MethodsActive components ofP. emblica and their candidate targets were screened by network pharmacology using the TCMSP and DrugBank databases (oral bioavailability≥30%, drug-likeness≥0.18) and intersected with inflammation-related genes retrieved from public databases. The predicted interaction between EGCG and IFN-I pathway proteins (TBK1, IRF3, STAT1) was evaluated by molecular docking, with BX795 and GSK8612 used as reference TBK1 inhibitors. Mechanistic experiments were performed in THP-1-derived macrophages and primary bone marrow-derived macrophages (BMDM). Upstream signaling was activated by transfection of the nucleic acid analogs poly(I∶C) and poly(dA∶dT) or by lipopolysaccharide (LPS) stimulation, whereas downstream signaling was activated by exogenous IFN-β. An siRNA-mediated TREX1 knockdown model was used to mimic endogenous nucleic acid-driven interferonopathy. Expression of IFN-β1 and interferon-stimulated genes (ISGs) was measured by RT-qPCR, protein phosphorylation by Western blot, and IFN-β secretion by ELISA. Cellular thermal shift assay (CETSA) and drug affinity responsive target stability (DARTS) were used to probe the interactionbetween EGCG and IRF3. ResultsNetwork pharmacology identified (-)-epigallocatechin-3-gallate (EGCG) as a candidate IFN-I-suppressive constituent of P. emblica, with predicted binding to TBK1, IRF3, and STAT1. Molecular docking yielded binding energies of -9.2, -7.2, and -8.2 kcal/mol for TBK1, IRF3, and STAT1, respectively, indicating an affinity for TBK1 comparable to that of the reference inhibitors BX795 (-5.7 kcal/mol) and GSK8612 (-6.4 kcal/mol). EGCG suppressed IFN-β1 and ISG mRNA expression under poly (I∶C), poly (dA∶dT), and LPS stimulation in both THP-1 macrophages and BMDM. At the protein level, EGCG reduced the phosphorylation of TBK1 and IRF3 without affecting the levels of the upstream sensors cGAS and RIG-I, and lowered IFN-β secretion in a concentration-dependent manner. CETSA and DARTS showed that EGCG did not enhance the thermal stability or protease resistance of IRF3, indicating that its effect on IRF3 is indirect. Following IFN-β stimulation, prolonged EGCG treatment reduced STAT1 phosphorylation in a time-dependent manner without an apparent change in IRF9, and partially attenuated ISG transcription; this effect was not monotonicly concentration-dependent, and CXCL10 showed the most consistent suppression. In TREX1-knockdown cells, the elevated mRNA levels of ISG15, ISG56, and CXCL10 were reduced by EGCG. ConclusionEGCG suppresses IFN-I responses by concurrently inhibiting TBK1-IRF3-dependent IFN‑β production and JAK-STAT1-mediated downstream transcription. These in vitro findings provide a mechanistic basis for the anti-inflammatory use of P. emblica in traditional medicine and identify EGCG as a candidate for further evaluation in interferon-driven autoimmune disease models.
6.Experimental study of epigallocatechin gallate-loaded hydrogel scaffold for the treatment of periodontitis
Longge LIU ; Jing MAO ; Huimin ZHENG ; Wei LI
Acta Universitatis Medicinalis Anhui 2026;61(6):1013-1020
ObjectiveTo explore the structural characteristics, biocompatibility, anti-inflammatory and antioxidant properties of hyaluronic acid (HA)/silk fibroin (SF) composite hydrogel scaffolds loaded with epigallocatechin gallate (EGCG), and to provide a new material basis for the treatment of periodontitis. MethodsThe composite hydrogel scaffolds were constructed by cross-linking HA and SF and loaded with EGCG. The water absorption rate, degradation property and material characteristics were detected by scanning electron microscopy. The cytocompatibility and anti-inflammatory and antioxidant properties were evaluated by in vitro experiments. ResultsThe EGCG-loaded scaffolds exhibited a porous network structure and desirable swelling properties. In vitro experiments demonstrated that the scaffolds possessed good biocompatibility, along with the ability to inhibit the expression of inflammatory factors and scavenge reactive oxygen species. ConclusionThe HA/SF-EGCG composite scaffolds have excellent biocompatibility and dual functional activities of anti-inflammatory and antioxidant, providing a new strategy for improving the clinical treatment effect of periodontitis.
7.Brown Tumor: Rare Today, but Never to Be Forgotten
Min Jing Choo ; Liang Wei Wong
Journal of the ASEAN Federation of Endocrine Societies 2026;41(S1):77-
Introduction:
Brown tumors are rare skeletal manifestations of primary
hyperparathyroidism (PHPT), now seen in less than 5%
of cases due to widely accessible biochemical screening.
Despite being benign, they can mimic malignant bone
lesions, making diagnosis challenging.
Case:
A 45-year-old female presented with lethargy and
hypercalcemia (corrected calcium 3.5 mmol/L) and was
discharged after intravenous zoledronate. She returned
1 week later with an enlarging gingival mass present
for 2 months but not previously disclosed, with a strong
family history of malignancy. Examination revealed a 6
× 3 cm pedunculated lesion over the right alveolar ridge.
Biochemistry showed persistent hypercalcemia (2.7–2.9
mmol/L), hypophosphatemia, and elevated alkaline
phosphatase. Contrast-enhanced computed tomography of
the neck demonstrated lytic mandibular and skull changes,
raising suspicion for malignancy. Tumor markers and
multiple myeloma screening were negative. Parathyroid
hormone (PTH) later returned markedly elevated at 222.1
pg/mL (upper limit of normal 56.9 pg/mL), consistent
with PHPT, alongside concomitant vitamin D deficiency.
Excision biopsy of the mandibular lesion confirmed a
brown tumor on histopathology. Following preoperative
localization, she underwent left parathyroidectomy and
recovered without hungry bone syndrome. Histology
confirmed a parathyroid adenoma, and she has remained
normocalcemic since.
Brown tumors arise from prolonged osteoclastic activity
and represent advanced PHPT. Craniofacial involvement
is rare, with the mandible affected in 4–5% of cases,
and lesions may clinically and radiologically mimic
primary bone tumors or metastases, creating diagnostic
uncertainty. Hypercalcemia should be systematically
investigated to determine the underlying cause, with early
measurement of PTH to distinguish PTH-dependent from
PTH-independent etiologies. Untreated brown tumors
may result in bone pain, deformity, pathological fractures,
and functional impairment, highlighting the importance
of early detection and management.
Conclusion
Brown tumors, although rare, remain an important
differential diagnosis for lytic bone lesions in the context
of hypercalcemia. Early measurement of PTH and careful
clinical examination are essential to avoid misdiagnosis
and prevent disease-related morbidity.
Neoplasms
8.When Hyperprolactinemia Fails to Suppress: The Silent Gonadotroph in a Pituitary Macroadenoma
Min Jing Choo ; Liang Wei Wong
Journal of the ASEAN Federation of Endocrine Societies 2026;41(S1):85-
Introduction:
Pituitary macroadenomas may present with mass effects,
hypopituitarism, or hormone hypersecretion. Hyperprolactinemia, resulting from a prolactin-secreting tumor
or stalk compression, typically suppresses gonadotropins.
Thus, elevated follicle-stimulating hormone (FSH) and
luteinizing hormone (LH) with low testosterone in this
context are unusual. We report a macroprolactinoma with
a clinically non-functioning gonadotroph adenoma.
Case:
A 69-year-old male presented with acute giddiness and
headache while in Vietnam. He reported reduced libido
but no visual symptoms or galactorrhea. Examination
showed no neurological deficits, normal visual fields, and
secondary sexual characteristics; bilateral testes volume of
25 mL. Magnetic resonance imaging (MRI) brain revealed
a 1.6 × 2.2 × 2.1 cm pituitary macroadenoma compressing
the optic chiasm and pituitary stalk.
Initial pituitary evaluation demonstrated hyperprolactinemia (prolactin >200 µg/L; normal 2.4–13.1), central hypothyroidism (T4 6.8 pmol/L [7.8–14.4], thyroid-stimulating
hormone 2.3 mIU/L [0.38–5.3]), elevated FSH (21.5 IU/L
[1.2–19.2]) and LH (191 IU/L [1.24–8.62]), low testosterone
(8.88 nmol/L), normal insulin-like growth factor 1 (IGF-1)
(68 µg/L [46.5–191.9]), and cortisol 237 nmol/L. Cabergoline
was initiated at 0.25 mg twice weekly and titrated to 1
mg twice weekly over 4 months, alongside levothyroxine
25 µg daily.
Repeated MRI brain 2 months after cabergoline initiation
showed a persistent macroadenoma (1.7 × 2.2 × 2.2 cm) with
bilateral cavernous sinus extension. Prolactin decreased to
<170 µg/L, central hypothyroidism persisted; levothyroxine
was optimized, and hydrocortisone was initiated.
At the 5-month follow-up, prolactin further improved to
57 µg/L. Central hypothyroidism and borderline adrenal
function persisted, requiring continued replacement
therapy. Testosterone remained low-normal (10.2 nmol/L)
despite elevated FSH (15.4 IU/L) and LH (92 IU/L). Followup MRI and hormonal reassessment were planned in
May 2026.
Conclusion
Profoundly elevated prolactin level >200 µg/L and response
to cabergoline reflect true prolactinoma rather than stalk
effect. Persistently low testosterone with discordant high
FSH/LH suggests a non-functioning gonadotroph component producing biologically inactive gonadotropins. Definitive diagnosis requires histopathological confirmation,
while serial biochemical and radiological follow-up guides
management and clarifies tumor subtype.
Gonadotrophs
;
Hyperprolactinemia
9.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.
10.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.


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