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.

Osteoarthritis (OA), a highly prevalent degenerative joint disease worldwide, is defined by articular cartilage degradation, abnormal bone remodeling, and persistent chronic inflammation. It severely compromises patients’ quality of life, and currently, there is no radical cure. Abnormal mechanical stress is widely regarded as a core driver of OA pathogenesis, and the exploration of mechanical signal perception and transduction mechanisms has become crucial for deciphering OA’s pathophysiological processes. Piezo1, a key mechanosensitive cation channel belonging to the Piezo protein family, has recently gained significant attention due to its pivotal role in mediating cellular responses to mechanical stimuli in joint tissues. This review systematically examines Piezo1’s expression patterns, regulatory mechanisms, and pathological functions in OA, with a particular focus on its dual roles in modulating chondrocyte homeostasis and bone metabolism disorders, while also delving into the underlying molecular signaling pathways and potential therapeutic implications. Piezo1, consisting of approximately 2 500 amino acids and forming a unique trimeric propeller-like structure, is widely expressed in chondrocytes, osteocytes, mesenchymal stem cells, and synovial cells. It exhibits permeability to cations such as Ca²⁺, K⁺, and Na⁺, and directly responds to membrane tension changes induced by mechanical stimuli like fluid shear stress and mechanical overload. In OA patients and animal models, Piezo1 expression is significantly upregulated, especially in cartilage regions subjected to abnormal mechanical stress (e.g., human temporomandibular joint cartilage). This overexpression is closely associated with aggravated cartilage degeneration, increased chondrocyte apoptosis, accelerated cellular senescence, and intensified inflammatory responses. Mechanical overload and pro-inflammatory cytokines (e.g., IL-1β) are key inducers of Piezo1 upregulation: IL-1β activates the PI3K/AKT/mTOR signaling pathway to enhance Piezo1 expression, forming a pathogenic positive feedback loop that inhibits chondrocyte autophagy, promotes apoptosis, and further accelerates joint degeneration. Mechanistically, Piezo1 mediates OA progression through multiple interconnected pathways. When activated by mechanical stress, Piezo1 triggers excessive Ca²⁺ influx, leading to endoplasmic reticulum stress (ERS) and mitochondrial dysfunction, which directly induce chondrocyte apoptosis. This process involves the activation of downstream signaling cascades such as cGAS-STING and YAP-MMP13/ADAMTS5. YAP, a transcriptional regulator, upregulates the expression of matrix metalloproteinase 13 (MMP13) and aggrecanase (ADAMTS5), thereby accelerating cartilage matrix degradation. Additionally, Piezo1-driven Ca²⁺ overload promotes the accumulation of reactive oxygen species (ROS) and upregulates senescence markers (p16 and p21), accelerating chondrocyte senescence via the p38MAPK and NF-κB pathways. Senescent chondrocytes secrete senescence-associated secretory phenotype (SASP) factors (e.g., IL-6, IL-1β), further amplifying joint inflammation. In terms of bone metabolism, Piezo1 maintains joint homeostasis by promoting the differentiation of fibrocartilage stem cells into chondrocytes and balancing bone formation and resorption through regulating the FoxC1/YAP axis and RANKL/OPG ratio. Therapeutically, targeting Piezo1 shows promising potential. Preclinical studies have demonstrated that Piezo1 inhibitors (e.g., GsMTx4) can reduce joint damage and alleviate pain in OA mice. Simultaneously, siRNA-mediated co-silencing of Piezo1 and TRPV4 (another mechanosensitive channel) decreases intracellular Ca²⁺ concentration, inhibits chondrocyte apoptosis, and promotes cartilage repair. Conditional knockout of Piezo1 using Gdf5-Cre transgenic mice alleviates cartilage degeneration in post-traumatic OA models by downregulating MMP13 and ADAMTS5 expression. Despite existing challenges, such as off-target effects of inhibitors, inefficient local drug delivery, and interindividual genetic variability, strategies like developing selective Piezo1 antagonists, optimizing targeted nanocarriers, and combining Piezo1-targeted therapy with physical therapy provide viable avenues for clinical translation. The authors propose that Piezo1 serves as a critical therapeutic target for OA, and future research should focus on deciphering its context-dependent regulatory networks, developing tissue-specific intervention strategies, and validating their efficacy and safety in clinical trials to address the unmet medical needs of OA patients.

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 evaluate the cost utility of different influenza vaccination strategies for primary and secondary school students in Anshun City, so as to provide healtheconomic evidence for influenza prevention and control in this population. Methods: Based on the demographic data of 380 700 students aged 5-14 in Anshun City in 2024, a decision tree model for different influenza vaccination strategies was constructed. The incremental cost utility ratio (ICUR) and net monetary benefit (NMB) were calculated, and sensitivity analysis was performed to assess the robustness of the model results. Results: For influenza vaccination among primary and secondary school students in Anshun City, compared with the selfpaid strategy (2% coverage), the free strategy (45% coverage) and the target strategy (70% coverage) both yielded an ICUR of -7 874.29 yuan per quality adjusted life year (QALY). When using 1 and 3 times the per capita Gross Domestic Product (GDP) as the willingness to pay thresholds, the per capita Net Monetary Benefit (NMB) was 1 000, 1 600 and 2 900, 4 500 RMB, respectively. The number of influenza infections or school absenteeism decreased by 25% and 40%, while saving a total cost of (46.779 5 and 73.976 8) million yuan, and increasing QALY by 5 940.79 and 9 394.73, respectively. Sensitivity analysis showed that within the reasonable fluctuation range of parameters, the ICUR remained consistently lower than the one and three times willingness to pay. Furthermore, 99% of the simulation results for both the free and target strategies fell below those thresholds, indicating high robustness of the model results. Conclusion Implementing free and target influenza vaccination strategies for primary and secondary school students in Anshun City offer distinct cost utility advantages, and the advantage enhances as the vaccination coverage rate increases.

Body weight abnormalities, including overweight, obesity, and underweight, have become a dual public health challenge in Chinese adults: overweight and obesity lead to a variety of chronic complications, while underweight increases the risks of malnutrition, sarcopenia, and organ dysfunction. To systematically address these issues, multidisciplinary experts in endocrinology, sports science, nutrition, and psychiatry from various regions have held multiple weight management seminars. Based on the latest epidemiological data and clinical evidence, they expanded the guideline to include assessment and intervention strategies for underweight, in addition to the core content of obesity management. This guideline outlines the etiological mechanisms, evaluation methods, and multidimensional management strategies for overweight and obesity, covering key areas such as diagnosis and assessment, medical nutrition therapy, exercise prescription, pharmacological intervention, and psychological support. It is intended to provide a scientific and standardized approach to weight management across the adult population, aiming to curb the rising prevalence of obesity, mitigate complications associated with abnormal body weight, and improve nutritional status and overall quality of life.

Hepatocellular carcinoma(HCC),which is essentially primary liver cancer,is closely related to CD8+T cell immune infiltration and immune suppression.We constructed a CD8+T cells related risk score model to pre-dict the prognosis of HCC patients and provided therapeutic guidance based on the risk score.Using integrated bulk RNA sequencing(RNA-seq)and single-cell RNA sequencing(scRNA-seq)datasets,we identified stable CD8+T cell signatures.Based on these signatures,a 3-gene risk score model,comprised of KLRB1,RGS2,and TN-FRSF1B was constructed.The risk score model was well validated through an independent external validation co-hort.We divided patients into high-risk and low-risk groups according to the risk score and compared the differ-ences in immune microenvironment between these two groups.Compared with low-risk patients,high-risk patients have higher M2-type macrophage content(P＜0.0001)and lower CD8+T cells infiltration(P＜0.0001).High-risk patients predict worse response to immunotherapy treatment than low-risk patients(P＜0.01).Drug sensitivity a-nalysis shows that PI3K-β inhibitor AZD6482 and TGFβRII inhibitor SB505124 may be suitable therapies for high-risk patients,while the IGF-1R inhibitor BMS-754807 or the novel pyrimidine-based anti-tumor metabolic drug Gemcitabine could be potential therapeutic choices for low-risk patients.Moreover,expression of these 3-gene mod-el was verified by immunohistochemistry.In summary,the establishment and validation of a CD8+T cell-derived risk model can more accurately predict the prognosis of HCC patients and guide the construction of personalized treatment plans.

The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(＜0.5 ?),the longest hydrogen bond lifetime(＞8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(～120 ?3)and moderate conformational coherence(correlation coefficient～0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.

Objective The pathophysiological process of acute high-altitude hypoxia-induced lung injury affects protein expression levels,which are mainly evaluated by Western blot.No systematic study has investigated changes in internal control proteins as calibration loading amounts.Methods Lung injury at an altitude of 6000 m was induced in a low-pressure,low-oxygen chamber for 8,24,and 72 h using C57BL/6J mice.Establishment of the model was confirmed by hematoxylin and eosin staining.Expression levels of various internal control proteins,including vinculin,α-tubulin,eukaryotic translation initiation factor 5(EIF5),β-actin,and glyceraldehyde 3-phosphate dehydrogenase(GAPDH)were detected by Western blot,and total protein expression was detected by Coomassie blue staining.Furthermore,the lung injury model in vitro was establised by using,Bronchial epithelial cell(BZAS-2B)andhunman umbilical vein endothelial cells(HUVECS)confirmed by TUNEL staining.Expression levels of internal control proteins were detected by Western blot,and total protein expression was detected by Coomassie Blue staining.Results Acute 8,24,and 72 h hypoxic models were successfully established in lung tissue,demonstrating consistent total protein expression and stable levels of the internal reference proteins vinculin,α-tubulin,EIF5,andβ-actin.GAPDH expression was elevated in the HH8 h,HH24 h,and HH72 h groups compared with the normoxia(Nor)group,but only the increase at HH72 h groups was significant.Similarly,8,24,and 48 h hypoxic models were successfully established in BEAS-2B cells and HUVECs,with consistent total protein expression.In BEAS-2B cells,expression levels of the internal reference proteins β-actin and GAPDH were consistent with the normoxic control(NC)group,while vinculin,α-tubulin,and EIF5 expression levels were significantly reduced under hypoxic conditions for up to 24 h.In HUVECs,vinculin and α-tubulin expression levels were also consistent with the NC group,while EIF5,β-actin,and GAPDH expression levels were significantly reduced at 8 h and increased at 48 h.Conclusions Acute hypoxia induces lung tissue injury,and protein expression levels of the internal reference proteins vinculin,α-tubulin,EIF5,and β-actin are stable,making them suitable internal references for Western blot.Additionally,Western blot detected differential expression levels of the internal reference proteins vinculin,α-tubulin,EIF5,β-actin,and GAPDH in BEAS-2B cells and HUVECs,as the most important in vitro lung tissue models of hypoxia-induced injury.

Objective The pathophysiological process of acute high-altitude hypoxia-induced lung injury affects protein expression levels,which are mainly evaluated by Western blot.No systematic study has investigated changes in internal control proteins as calibration loading amounts.Methods Lung injury at an altitude of 6000 m was induced in a low-pressure,low-oxygen chamber for 8,24,and 72 h using C57BL/6J mice.Establishment of the model was confirmed by hematoxylin and eosin staining.Expression levels of various internal control proteins,including vinculin,α-tubulin,eukaryotic translation initiation factor 5(EIF5),β-actin,and glyceraldehyde 3-phosphate dehydrogenase(GAPDH)were detected by Western blot,and total protein expression was detected by Coomassie blue staining.Furthermore,the lung injury model in vitro was establised by using,Bronchial epithelial cell(BZAS-2B)andhunman umbilical vein endothelial cells(HUVECS)confirmed by TUNEL staining.Expression levels of internal control proteins were detected by Western blot,and total protein expression was detected by Coomassie Blue staining.Results Acute 8,24,and 72 h hypoxic models were successfully established in lung tissue,demonstrating consistent total protein expression and stable levels of the internal reference proteins vinculin,α-tubulin,EIF5,andβ-actin.GAPDH expression was elevated in the HH8 h,HH24 h,and HH72 h groups compared with the normoxia(Nor)group,but only the increase at HH72 h groups was significant.Similarly,8,24,and 48 h hypoxic models were successfully established in BEAS-2B cells and HUVECs,with consistent total protein expression.In BEAS-2B cells,expression levels of the internal reference proteins β-actin and GAPDH were consistent with the normoxic control(NC)group,while vinculin,α-tubulin,and EIF5 expression levels were significantly reduced under hypoxic conditions for up to 24 h.In HUVECs,vinculin and α-tubulin expression levels were also consistent with the NC group,while EIF5,β-actin,and GAPDH expression levels were significantly reduced at 8 h and increased at 48 h.Conclusions Acute hypoxia induces lung tissue injury,and protein expression levels of the internal reference proteins vinculin,α-tubulin,EIF5,and β-actin are stable,making them suitable internal references for Western blot.Additionally,Western blot detected differential expression levels of the internal reference proteins vinculin,α-tubulin,EIF5,β-actin,and GAPDH in BEAS-2B cells and HUVECs,as the most important in vitro lung tissue models of hypoxia-induced injury.

BACKGROUND:Recent studies have shown that β-sitosterol has a good inhibitory effect on hypertrophic scar fibroblasts.However,its clinical application is limited by its poor water solubility and unstable physicochemical properties.OBJECTIVE:To prepare β-sitosterol-laden nanoparticles with sustained drug release function and to analyze the therapeutic effect of the drug-laden nanoparticles on hypertrophic scars in rats.METHODS:Mesoporous silica nanoparticles and mesoporous silica@β-sitosterol nanoparticles were prepared,and the physicochemical properties of the two nanoparticles were characterized.A self-made traction device was used to continuously apply traction force to the wound surface of the tail of 48 SD rats(deep to the periosteum)to establish a tail hypertrophic scar model.On day 21 of continuous traction,the 36 rats with successful modeling were randomly divided into 4 groups for intervention using a random number table method,with 9 rats in each group:the control group was injected with normal saline into the scar tissue,and the mesoporous silica group,β-sitosterol group,and mesoporous silica@β-sitosterol group were injected with mesoporous silica nanoparticle solution,β-sitosterol suspension,and mesoporous silica@β-sitosterol nanoparticle solution into the scar tissue,respectively,once a week for 6 consecutive weeks.Scar area and clinical scar score were recorded before injection and 14 and 42 days after injection.One week after the last injection,hematoxylin-eosin staining and Masson staining were used to evaluate dermal thickness and collagen fiber deposition and arrangement.Immunohistochemical staining was used to evaluate the expression of type Ⅰ collagen and α-smooth muscle actin in scars.Western blot assay was used to detect the protein expression of autophagy marker LC3-Ⅱ and apoptosis marker cleaved caspase-3 in scars.RESULTS AND CONCLUSION:(1)Under transmission electron microscopy,both nanoparticles were hollow spheres,and the mesoporous structure of mesoporous silica@β-sitosterol nanoparticles was fuzzy and the average particle size was slightly larger.Infrared spectroscopy showed that β-sitosterol was successfully encapsulated in mesoporous silica nanoparticles.The drug encapsulation rate and drug loading rate of mesoporous silica@β-sitosterol nanoparticles were 88.34％and 39.77％,respectively.The solubility of mesoporous silica@β-sitosterol nanoparticles was stronger than that of free β-sitosterol,and β-sitosterol could be slowly released in vitro for more than 6 days.(2)The results of animal experiments showed that the scar area of the mesoporous silica@β-sitosterol group was smaller than that of the other three groups 42 days after injection(P＜0.05).The clinical scar scores at 14 and 42 days after injection were lower than those of the control group and the mesoporous silica group(P＜0.05).The results of hematoxylin-eosin staining and Masson staining showed that the scar dermis thickness of the mesoporous silica@β-sitosterol group was reduced compared with the control group,the mesoporous silica group,and the β-sitosterol group(P＜0.05),and the collagen arrangement was relatively neat and regular in direction.The results of immunohistochemical staining showed that the expression of type Ⅰ collagen and α-smooth muscle actin in the mesoporous silica@β-sitosterol group was lower than that of the other three groups(P＜0.05).The results of western blot assay showed that the expression of LC3-Ⅱ protein in the mesoporous silica@β-sitosterol group was lower than that of the other three groups(P＜0.05),and the expression of cleaved Caspase-3 protein was higher than that of the other three groups(P＜0.05).(3)The results showed that mesoporous silica@β-sitosterol nanoparticles effectively improved the water solubility and water dispersibility of β-sitosterol,and had excellent drug controlled release properties.They could inhibit the autophagy of fibroblasts in the lesions and induce their apoptosis,thereby inhibiting collagen deposition,promoting the fading and remodeling of hypertrophic scars.