1.Effect of Runmu Dihuang Decoction on Perimenopausal Dry Eye in Rats with Liver-kidney Yin Deficiency Syndrome Based on SIRT3/HIF-1α/NF-κB Signaling Pathway
Sainan TIAN ; Wei MA ; Yao CHEN ; Yu CAO ; Guicheng LIU ; Pei LIU ; Junxian LEI ; Qinghua PENG ; Jun PENG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(7):201-210
ObjectiveTo investigate the mechanisms of Runmu Dihuang decoction (RMDHD) in treating perimenopausal dry eye with liver-kidney Yin deficiency syndrome based on the silent information regulator 3 (SIRT3)/hypoxia-inducible factor-1α (HIF-1α)/nuclear factor-κB (NF-κB) signaling pathway. MethodsSixty female Sprague-Dawley rats were randomly divided into six groups (n=10 per group): Sham operation group, model group, sodium hyaluronate eye drop group, and low-, medium-, and high-dose RMDHD groups (5.625, 11.25, 22.50 g·kg-1). Except for the sham operation group, all rats underwent bilateral ovariectomy and were administered 0.1% benzalkonium chloride eye drops combined with long-term chronic irritation to establish a perimenopausal dry eye model with liver-kidney Yin deficiency syndrome. Drug administration began in the 11th week after modeling and continued for 21 days. General conditions, screen-grip test scores, tear secretion volume, tear film breakup time (TFBUT), and corneal fluorescein staining were recorded. Serum levels of reactive oxygen species (ROS), follicle-stimulating hormone (FSH), estradiol (E2), and progesterone (PROG) were measured by enzyme-linked immunosorbent assay (ELISA). Pathological changes in the lacrimal glands, corneas, and uteri were observed using hematoxylin-eosin (HE) staining. Protein expression levels of SIRT3, HIF-1α, phosphorylated NF-κB p65 (p-NF-κB p65), and total NF-κB p65 in the lacrimal glands were detected by Western blot. The expression of inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the lacrimal glands was assessed by immunohistochemistry (IHC). ResultsAfter model establishment, no significant differences were observed among the groups except the sham operation group. Compared with the sham operation group, the other groups exhibited slowed movement, dull responses, increased irritability, reduced body weight, elevated rectal temperature, decreased screen-grip test scores, reduced tear secretion, and significantly shortened TFBUT (P<0.05). After treatment, compared with the model group, the sodium hyaluronate eye drop group and all RMDHD groups showed improved general conditions, significantly increased tear secretion (P<0.05), prolonged TFBUT (P<0.05), and elevated screen-grip test scores (P<0.05). Serum ROS and FSH levels were significantly decreased, while E2 and PROG levels were significantly increased (P<0.05). Pathological damage to the cornea, lacrimal glands, and uterus was ameliorated. In addition, protein expression levels of SIRT3 and HIF-1α in the lacrimal glands were significantly upregulated (P<0.05), whereas the expression of p-NF-κB p65, IL-1β, and TNF-α was significantly downregulated (P<0.05). ConclusionRMDHD increases tear secretion and TFBUT, improves lacrimal gland and corneal injury, and alleviates dry eye symptoms in a perimenopausal dry eye rat model with liver-kidney Yin deficiency syndrome. The underlying mechanism may be related to regulation of the SIRT3/HIF-1α/NF-κB signaling pathway, inhibition of oxidative stress and inflammatory responses, and reduction of ocular surface tissue damage.
2.Analysis of knowledge awareness and associated factors of chikungunya fever among medical college students in Baise City
Chinese Journal of School Health 2026;47(3):347-350
Objective:
To understand the awareness of chikungunya fever knowledge and its related factors among medical college students in Baise City, so as to provide a scientific basis to offer relevant courses and special education.
Methods:
From July to August 2025, 7 286 enrolled medical students were selected by a sampling method from a medical college in Baise City to participate in the questionnaire survey. The questionnaire covered epidemiological characteristics, clinical symptoms, and prevention/control knowledge of chikungunya fever. Statistical analyses including the Chi quare test and multivariate Logistic regression models were performed.
Results:
The overall awareness rate of chikungunya fever knowledge among the medical students was 18.89%. Among the knowledge items, the awareness rate of "the high incidence season" was the highest (84.05%), while that of "the infectious period" was the lowest (17.80%). Multivariate Logistic regression analysis showed that medical students with female (a OR= 1.37 , 95%CI =1.20- 1.57 ), the age for over 25 years old (a OR=1.76, 95%CI =1.05-2.93), whose father had a middle school educational level (a OR=1.18, 95%CI =1.05-1.31), and majored in preventive medicine (a OR=1.54, 95%CI =1.10-1.67) had relatively higher awareness rates of chikungunya fever knowledge (all P <0.05). In contrast, students of Zhuang ethnicity (a OR= 0.87 , 95%CI =0.76-0.98) and majoring in nursing (a OR=0.74, 95%CI =0.61-0.91) or pharmacy (a OR=0.70, 95%CI =0.52-0.95) had relatively lower awareness rates (all P <0.05).
Conclusions
The awareness rate of chikungunya fever related knowledge among medical college students in Baise City is relatively low. Schools should take targeted publicity measures to improve medical students awareness.
3.Xuefu Zhuyutang in Malignant Tumor Disease: A Review
Jiaqi JI ; Xiaoqing HU ; Yihan ZHAO ; Xuhang SUN ; Dandan WEI ; Junwen PEI ; Shiqing JIANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):321-330
Cancer has become a significant global public health issue, severely impacting public health and societal development. Despite advances in tumor treatment methods in recent years and a gradual decline in cancer mortality rates, drug-related adverse reactions and drug resistance remain substantial challenges. Traditional Chinese medicine (TCM) has demonstrated significant clinical efficacy in cancer treatment and small side effects, making it widely applied in the field of oncology. Xuefu Zhuyutang, derived from Yilin Gaicuo, is known for its abilities to invigorate blood circulation, dispel blood stasis, promote Qi flow, and alleviate pain. It was specifically formulated by the esteemed WANG Qingren of the Qing dynasty for the "blood stasis syndrome in the blood mansion" and is commonly used to treat Qi stagnation and blood stasis syndrome. Clinical studies have shown that Xuefu Zhuyutang, when combined with conventional Western medications, produces significant effects in the treatment of malignant tumors such as liver cancer, lung cancer, and cervical cancer. It substantially reduces the incidence of adverse reactions following Western treatments, including radiation esophagitis, radiation encephalopathy, radiation-induced oral mucositis, and edema. Additionally, it alleviates cancer-related pain and fever, blood hypercoagulability, and associated complications such as depression and anxiety, and also mitigates chemotherapy-induced side effects like hand-foot syndrome. Basic research has demonstrated its potential anti-tumor mechanisms, including the inhibition of Wnt/β-catenin signaling pathway activation, suppression of mitogen-activated protein kinase (MAPK) pathway activation, and anti-tumor angiogenesis. Pharmacological studies have revealed that its active components inhibit tumor cell proliferation and migration, induce tumor cell apoptosis, suppress tumor angiogenesis, enhance the cytotoxicity of natural killer cells against tumors, improve the tumor microenvironment, and regulate immune function. This paper reviewed the latest research progress on Xuefu Zhuyutang in the treatment of malignant tumors from four aspects: theoretical exploration, clinical studies, mechanisms of action, and pharmacological basis, aiming to provide insights and methods for the clinical diagnosis and treatment of malignant tumors.
4.Xuefu Zhuyutang in Malignant Tumor Disease: A Review
Jiaqi JI ; Xiaoqing HU ; Yihan ZHAO ; Xuhang SUN ; Dandan WEI ; Junwen PEI ; Shiqing JIANG
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(3):321-330
Cancer has become a significant global public health issue, severely impacting public health and societal development. Despite advances in tumor treatment methods in recent years and a gradual decline in cancer mortality rates, drug-related adverse reactions and drug resistance remain substantial challenges. Traditional Chinese medicine (TCM) has demonstrated significant clinical efficacy in cancer treatment and small side effects, making it widely applied in the field of oncology. Xuefu Zhuyutang, derived from Yilin Gaicuo, is known for its abilities to invigorate blood circulation, dispel blood stasis, promote Qi flow, and alleviate pain. It was specifically formulated by the esteemed WANG Qingren of the Qing dynasty for the "blood stasis syndrome in the blood mansion" and is commonly used to treat Qi stagnation and blood stasis syndrome. Clinical studies have shown that Xuefu Zhuyutang, when combined with conventional Western medications, produces significant effects in the treatment of malignant tumors such as liver cancer, lung cancer, and cervical cancer. It substantially reduces the incidence of adverse reactions following Western treatments, including radiation esophagitis, radiation encephalopathy, radiation-induced oral mucositis, and edema. Additionally, it alleviates cancer-related pain and fever, blood hypercoagulability, and associated complications such as depression and anxiety, and also mitigates chemotherapy-induced side effects like hand-foot syndrome. Basic research has demonstrated its potential anti-tumor mechanisms, including the inhibition of Wnt/β-catenin signaling pathway activation, suppression of mitogen-activated protein kinase (MAPK) pathway activation, and anti-tumor angiogenesis. Pharmacological studies have revealed that its active components inhibit tumor cell proliferation and migration, induce tumor cell apoptosis, suppress tumor angiogenesis, enhance the cytotoxicity of natural killer cells against tumors, improve the tumor microenvironment, and regulate immune function. This paper reviewed the latest research progress on Xuefu Zhuyutang in the treatment of malignant tumors from four aspects: theoretical exploration, clinical studies, mechanisms of action, and pharmacological basis, aiming to provide insights and methods for the clinical diagnosis and treatment of malignant tumors.
5.Research progress on the regulation of JNK signaling pathway by traditional Chinese medicine for intervention in central nervous system diseases
Hongwei WANG ; Mingliang QIAO ; Chenyi ZHAO ; Pei ZHU ; Zilong WEI ; Yi MENG
China Pharmacy 2026;37(2):257-262
The c-Jun N-terminal kinase (JNK) signaling pathway, a key member of the mitogen-activated protein kinase (MAPK) family, plays a central role in the pathogenesis and progression of central nervous system (CNS) diseases by regulating core biological processes such as apoptosis, inflammatory responses, synaptic plasticity, and autophagy. This article sorts out and analyzes relevant literature published domestically and internationally in recent years, summarizing the mechanisms of action of the JNK signaling pathway in common CNS diseases and the research progress in traditional Chinese medicine (TCM) interventions in CNS diseases through the regulation of the JNK signaling pathway. Studies have shown that active components of TCM, such as berberine, paeoniflorin, and astragaloside Ⅳ, as well as compound formulations like Heixiaoyao san, Ditan tang, and Buyang huanwu tang, can exert neuroprotective effects in various CNS disorders, including Alzheimer’s disease, Parkinson’s disease, cerebral ischemia-reperfusion injury, and epilepsy, by inhibiting the aberrant activation of the JNK signaling pathway, thereby alleviating neuroinflammation, oxidative stress, and neuronal apoptosis, while improving synaptic function and cognitive behavioral deficits, regulating autophagy, and maintaining blood-brain barrier integrity.
6.Strategies of HIV-1 Vaccines Based on mRNA Platforms
Pei LIU ; Zhong-Yue FANG ; Xin-Xin CHEN ; Shao-Wei LI ; Ying GU
Progress in Biochemistry and Biophysics 2026;53(4):826-839
Since its emergence in the 1980s, the human immunodeficiency virus (HIV) has caused a global pandemic, posing a severe threat to human life and health as well as social development. Although pre-exposure prophylaxis (PrEP) effectively curbs HIV transmission and antiretroviral therapy (ART) significantly extends the lifespan of patients, vaccines remain a pivotal tool for blocking transmission and ending the pandemic. The high genetic variability of HIV-1, the glycan shield of its envelope glycoproteins, and the long-term persistence of latent reservoirs have repeatedly led to bottlenecks in traditional vaccine strategies. In recent years, mRNA technology has offered a novel approach to addressing these challenges, leveraging advantages such as sequence programmability, short production cycles, native conformational expression of antigens, and self-adjuvant effects. In recent years, mRNA vaccine technology has emerged as a transformative solution to longstanding vaccinology challenges, characterized by its sequence programmability, rapid production cycles, native conformational antigen expression, and intrinsic self-adjuvanting properties. Unlike traditional platforms reliant on pathogen culture or recombinant proteins, mRNA vaccines can be expeditiously designed and updated based solely on viral genomic sequences. Lipid nanoparticle (LNP)-encapsulated mRNA facilitates endogenous antigen expression and presentation, simultaneously eliciting potent humoral and cellular immune responses. Within this landscape, self-amplifying mRNA (saRNA) further extends in vivo antigen expression to enhance the persistence of immune responses. Moreover, the LNP delivery system not only protects mRNA from degradation and mediates endosomal escape but also synergizes with mRNA to optimize immune activation via self-adjuvant effects. Importantly, mRNA platforms circumvent the pre-existing immunity associated with viral vectors and the genomic integration risks of DNA vaccines, positioning them as a cornerstone for global pandemic preparedness. This review systematically delineates recent advances in mRNA technology for HIV-1 vaccine development, focusing on four pivotal research frontiers. First, mRNA innovations building upon the RV144 trial optimize antigens through codon modification and multivalent designs to induce more durable and broad-spectrum immunity. Second, particulate mRNA vaccine strategies, utilizing virus-like particles (VLPs) and ferritin nanoparticles, achieve in situ antigen self-assembly, significantly enhancing B cell activation and reducing infection risks in non-human primate models. Third, germline-targeting mRNA vaccines address the low-affinity barrier of broadly neutralizing antibody (bNAp) precursors, efficiently activating rare precursor B cells and promoting affinity maturation. Fourth, therapeutic mRNA vaccines offer unique advantages for an HIV functional cure; combining immunogens with mRNA-encoded adjuvants potentiates cellular immunity, while LNP-mediated “shock-and-kill” strategies specifically activate latent reservoirs to guide immune clearance. Comparative analyses with traditional platforms reveal that mRNA technology redefines antigen production and presentation, simulating chronic infection through sustained expression and enabling dual-pathway presentation via endogenous synthesis. Furthermore, we explore the mechanistic innovations of mRNA vaccines in inducing bNAps: sustained in vivo production prolongs the activation window for precursor B cells and maintains germinal center (GC) reactions; endogenously expressed antigens adopt native conformations to expose conserved epitopes; and self-adjuvanting effects modulate the functions of antigen-presenting cells (APCs) and follicular helper T cells (Tfh), driving somatic hypermutation and affinity maturation. We also address critical clinical translation challenges, including immune durability, adaptability to special populations, and large-scale LNP manufacturing, while proposing targeted optimization strategies. In conclusion, this review establishes a theoretical framework for utilizing mRNA technology to overcome HIV-1 immune escape, transitioning from a descriptive paradigm to a problem-solving-based synthesis of evidence. By integrating preclinical and early clinical data, we bridge the gap between basic design and translational verification. mRNA technology is poised to become a central pillar inHIV-1 prevention and therapy, providing a robust toolset to achieve the global goal of ending the AIDS pandemic and offering a blueprint for vaccine development against other recalcitrant infectious diseases.
7.Effects of ammonia poisoning on cognitive behavior and hippocampal synaptic damage in mice
Jiuxuan ZHANG ; Jinnan ZHANG ; Xiaofan SUI ; Xiaxia PEI ; Jianhong WEI ; Qiang SU ; Tian LI
Chinese Journal of Tissue Engineering Research 2026;30(5):1122-1128
BACKGROUND:Ammonia poisoning is considered to be the main hypothesis for the pathogenesis of hepatic encephalopathy.Ammonia can lead to psychiatric and cognitive behavioral disorders,although the specific pathological molecular mechanisms remain unclear.OBJECTIVE:To investigate the effects of ammonia poisoning on cognitive behavior and hippocampal neuronal synapses in mice.METHODS:Thirty-two C57BL/6J mice were randomly divided into a normal control group and an ammonium chloride group,with 16 mice in each group.Normal saline was injected intraperitoneally in the control group,and ammonium chloride(10 mmol/kg)was injected intraperitoneally in the ammonium chloride group to construct a model of ammonia poisoning,once a day.After 7 days of ammonium chloride intervention,blood samples were collected from the hearts of six mice in each group for blood ammonia concentration detection.Behavioral experiments,including the open field test,novel object recognition test,and Y-maze test,were performed to assess mental and cognitive-behavioral changes in mice.Finally,hippocampal tissues were extracted for western blot analysis to detect the expression levels of synaptophysin and postsynaptic density protein-95 in hippocampal neurons.RESULTS AND CONCLUSION:The blood ammonia concentration was significantly elevated in the ammonium chloride group compared with the control group(P<0.05).Mice in the ammonium chloride group showed anxiety-like behavior and disinhibition phenomenon,and a significant decrease in recognition memory and working memory ability.Western blot results revealed that the expression of synaptophysin and postsynaptic density protein-95 protein in hippocampal neurons in the ammonium chloride group was lower than that in the control group(P<0.05).To conclude,ammonia poisoning can induce hippocampal neuronal synaptic damage,leading to psychiatric and cognitive behavioral abnormalities in mice.
8.Effects of ammonia poisoning on cognitive behavior and hippocampal synaptic damage in mice
Jiuxuan ZHANG ; Jinnan ZHANG ; Xiaofan SUI ; Xiaxia PEI ; Jianhong WEI ; Qiang SU ; Tian LI
Chinese Journal of Tissue Engineering Research 2026;30(5):1122-1128
BACKGROUND:Ammonia poisoning is considered to be the main hypothesis for the pathogenesis of hepatic encephalopathy.Ammonia can lead to psychiatric and cognitive behavioral disorders,although the specific pathological molecular mechanisms remain unclear.OBJECTIVE:To investigate the effects of ammonia poisoning on cognitive behavior and hippocampal neuronal synapses in mice.METHODS:Thirty-two C57BL/6J mice were randomly divided into a normal control group and an ammonium chloride group,with 16 mice in each group.Normal saline was injected intraperitoneally in the control group,and ammonium chloride(10 mmol/kg)was injected intraperitoneally in the ammonium chloride group to construct a model of ammonia poisoning,once a day.After 7 days of ammonium chloride intervention,blood samples were collected from the hearts of six mice in each group for blood ammonia concentration detection.Behavioral experiments,including the open field test,novel object recognition test,and Y-maze test,were performed to assess mental and cognitive-behavioral changes in mice.Finally,hippocampal tissues were extracted for western blot analysis to detect the expression levels of synaptophysin and postsynaptic density protein-95 in hippocampal neurons.RESULTS AND CONCLUSION:The blood ammonia concentration was significantly elevated in the ammonium chloride group compared with the control group(P<0.05).Mice in the ammonium chloride group showed anxiety-like behavior and disinhibition phenomenon,and a significant decrease in recognition memory and working memory ability.Western blot results revealed that the expression of synaptophysin and postsynaptic density protein-95 protein in hippocampal neurons in the ammonium chloride group was lower than that in the control group(P<0.05).To conclude,ammonia poisoning can induce hippocampal neuronal synaptic damage,leading to psychiatric and cognitive behavioral abnormalities in mice.
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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