Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Objective Magnetoreception, the remarkable ability of diverse animals to sense and utilize the geomagnetic field for orientation and navigation, remains a molecularly unresolved mystery in sensory biology. The putative magnetoreceptor (MagR, previously known as IscA1) is a highly conserved iron-sulfur protein implicated in both magnetoreception and iron metabolism; however, the functional diversity among its cross-species homologs remains poorly understood. Cellular morphology is a key genetically determined trait that can be altered through genetic or environmental modifications—a process known as cell morphology engineering. Constructing engineered cells with specific morphological features and magnetic sensitivity to achieve remote, non-invasive magnetic modulation represents a crucial goal in this field with significant application potential. Therefore, this study aims to systematically investigate the effects of MagR heterologous expression on bacterial morphology and magnetic sensing capabilities, screen for MagR-based magnetically sensitive morphology engineering pathways, and reveal the underlying molecular mechanisms. Methods We systematically screened 28 MagR homologous genes from diverse prokaryotic and animal taxa to evaluate their expression and corresponding phenotypic effects in Escherichia coli (E. coli). To compare the differential magnetic responses among bacteria expressing various recombinant MagR proteins, we utilized high-throughput automated bright-field microscopic imaging and scanning electron microscopy (SEM). Furthermore, comprehensive biochemical and biophysical characterizations of iron and iron-sulfur cluster binding were performed using Ferrozine colorimetric assays, electron paramagnetic resonance (EPR) spectroscopy, ultraviolet-visible (UV-Vis) absorption, and circular dichroism (CD) spectroscopy. Additionally, 100 mT static magnetic field (SMF) exposure experiments were conducted to assess magnetically tunable phenotypes, while the intrinsic magnetic properties of purified MagR proteins were directly measured using a superconducting quantum interference device (SQUID) magnetometer. Results Our results demonstrated that the heterologous expression of MagR homologs induced varying degrees of bacterial filamentation. From this comprehensive screen, two distinct morphological patterns were identified: hydra (Hydra vulgaris) MagR (hyMagR) promoted uniform cell elongation and filamentation, exhibiting robust magnetic sensitivity manifested as significantly enhanced filamentation under the 100 mT SMF. In contrast, pigeon (Columba livia) MagR (clMagR) induced only low-frequency, extreme filamentation (sporadically exceeding 80 μm) with a relatively weaker magnetic morphological response. Mechanistically, our data unambiguously proved that these phenotypic differences are primarily driven by distinct iron redox preferences rather than total cellular iron accumulation. Specifically, hyMagR preferentially binds ferrous iron (Fe²⁺), whereas clMagR favors ferric iron (Fe³⁺) and forms more stable iron-sulfur clusters. Intriguingly, although SQUID magnetometry showed that purified clMagR exhibited approximately five-fold higher mass magnetic susceptibility than hyMagR, its cellular magnetic response was weaker. We hypothesize that the Fe²⁺-preferred intracellular environment associated with hyMagR overexpression primes the cell for enhanced generation of reactive oxygen species (ROS) via the Fenton reaction. Exposure to an SMF synergizes with this primed redox state, triggering the bacterial SOS response and upregulating cell division inhibitors to efficiently induce uniform filamentation. Conclusion Our findings identify the Fe²⁺/Fe³⁺ redox state as a critical determinant of MagR-mediated morphological remodeling and magnetic responsiveness. This discovery suggests a potential strategy for engineering magnetically responsive cellular systems for synthetic biology applications, and provides a plausible framework, which potentially combines intrinsic protein magnetism with redox-state modulation, for further investigating the evolutionary mechanisms of MagR-mediated magnetoreception.

Background: Visceral white adipose tissue (vWAT) inflammation is a critical pathology of obesity-caused heart damage and is closely associated with adipocyte endoplasmic reticulum (ER) dysfunction. Serine (or cysteine) peptidase inhibitor, clade A, member 3C (Serpina3c) has been identified as an adipokine with anti-vWAT inflammatory effects. However, it remains unclear whether Serpina3c deficiency promotion of vWAT inflammation involves adipocyte ER dysfunction and whether it further contributes to heart damage in obesity. Methods: Wild type and Serpina3c knockout (Serpina3c–/–) mice were fed a high-fat diet (HFD) for 12 weeks. An adeno-associated virus (AAV) was injected locally into epididymal white adipose tissue (eWAT) of Serpina3c–/– mice to induce eWAT-adipocyte- specific overexpression of Serpina3c (AAV-Serpina3c) or knockdown of hypoxia-inducible factor 1α (AAV-shHIF1α). In vitro experiments were performed in 3T3-L1 adipocytes. Results: Serpina3c–/– mice exhibited more severe eWAT, serum and heart inflammation after HFD feeding. Consistently, these adverse phenotypes were mitigated in AAV-Serpina3c and AAV-shHIF1α mice. Mechanistically, ER oxidoreductase 1α (Ero1α) and protein disulfide isomerase (PDI) family members PDIA3 and PDIA4 were found to be target genes of HIF1α. In the obese mice, Serpina3c deficiency caused adipocyte more hypertrophy, and activated HIF1α-Ero1α/PDI mediated ER overoxidation and ER stress in eWAT. Subsequently, this led to increased adipocyte apoptosis and chemokine production and decreased adiponectin expression, which promoted macrophage infiltration and M1 polarization in eWAT, thus exacerbating eWAT inflammation and ultimately facilitating serum and distal heart inflammation. Conclusion These findings indicate that Serpina3c is a significant regulator of adipocyte ER redox homeostasis, thus highlighting Serpina3c as a potential therapeutic target for obesity-related eWAT inflammation and heart damage.

Background Large-for-gestational-age (LGA) births are associated with adverse perinatal outcomes and increased risks of offspring obesity, metabolic syndrome, and cardiovascular diseases later in life. Beyond traditional risk factors, exposure to environmental factors, especially fine particulate matter (PM_2.5), before and during pregnancy may contribute to excessive fetal growth; however, the roles of specific chemical constituents and critical exposure windows remain unclear. Objective To examine the associations between maternal exposures to PM_2.5 and its chemical constituents before and during pregnancy and the risk of delivering LGA infants. Methods Singleton pregnancies from the National Free Preconception Health Examination Project between 2010 and 2014 were included. Individual exposures to PM_2.5 and its constituents were estimated for preconception and pregnancy windows using geocoded residential addresses. The associations of single and mixed exposures with LGA risk were analyzed using generalized linear models (GLMs) and qg-computation. Results Exposures to PM_2.5 and its major chemical constituents were significantly associated with an increased LGA risk, with differences in effect magnitude across components. Secondary inorganic aerosols showed the strongest associations. For full-pregnancy exposure, nitrate (OR=1.330, 95%CI: 1.313, 1.347), ammonium (OR=1.279, 95%CI: 1.263, 1.295), and sulfate (OR=1.242, 95%CI: 1.227, 1.257) had larger effects on LGA risk than black carbon and organic matter. Analysis by exposure window indicated that the month preceding conception and the third trimester of pregnancy were critical exposure windows for susceptibility, while the strongest effect was observed for full-pregnancy exposure, suggesting a cumulative effect over time. Mixed exposure analysis further showed that nitrate and sulfate consistently accounted for the main positive contributions across different time windows. Conclusion Maternal exposures to PM_2.5 and its chemical components before and during pregnancy are associated with an elevated LGA risk. Nitrate and sulfate show consistent and strong associations across pregnancy stages, underscoring the importance of component composition and exposure timing in fetal overgrowth.

Objectives: This study evaluates the efficacy of a new temporomandibular joint (TMJ) capsule suspension technique for stabilizing the TMJ after free fibular flap reconstruction of the mandibular condyle. Patients and Methods: Patients undergoing the TMJ capsule suspension technique during free fibular flap reconstruction after mandibulectomy with condylectomy (study group; n=9) were compared with a control group (n=9). Mandibular movement trajectory and surface electromyographic signals of bilateral masseters were recorded. The neocondyle–disc relationship was examined with magnetic resonance imaging (MRI) at 6 months after surgery. Results: Maximal mouth opening and bilateral marginal movement distances were comparable between the two groups (P>0.05). The asymmetry index of the condyle path length was significantly higher in controls (P=0.02). Bilateral mouth opening trajectories were symmetric in 7 patients and deviated to the affected side in 2 patients in the study group; they deviated to the affected side in all controls. The mean electromyographic values of the masseter on the affected side in resting, maximum bite, and chewing states were comparable between the two groups (P=0.13, P=0.65, and P=0.82, respectively). On MRI at 6 months, the thicknesses of the anterior, medial, and posterior bands and TMJ disc length were similar on the affected and normal sides in the study group (P=0.57, P=0.13, P=0.48, and P=0.87, respectively). Conclusion The proposed TMJ capsule suspension technique could improve postoperative TMJ structure and function after fibular free flap reconstruction following mandibulectomy with condylectomy.

Objectives: This study evaluates the efficacy of a new temporomandibular joint (TMJ) capsule suspension technique for stabilizing the TMJ after free fibular flap reconstruction of the mandibular condyle. Patients and Methods: Patients undergoing the TMJ capsule suspension technique during free fibular flap reconstruction after mandibulectomy with condylectomy (study group; n=9) were compared with a control group (n=9). Mandibular movement trajectory and surface electromyographic signals of bilateral masseters were recorded. The neocondyle–disc relationship was examined with magnetic resonance imaging (MRI) at 6 months after surgery. Results: Maximal mouth opening and bilateral marginal movement distances were comparable between the two groups (P>0.05). The asymmetry index of the condyle path length was significantly higher in controls (P=0.02). Bilateral mouth opening trajectories were symmetric in 7 patients and deviated to the affected side in 2 patients in the study group; they deviated to the affected side in all controls. The mean electromyographic values of the masseter on the affected side in resting, maximum bite, and chewing states were comparable between the two groups (P=0.13, P=0.65, and P=0.82, respectively). On MRI at 6 months, the thicknesses of the anterior, medial, and posterior bands and TMJ disc length were similar on the affected and normal sides in the study group (P=0.57, P=0.13, P=0.48, and P=0.87, respectively). Conclusion The proposed TMJ capsule suspension technique could improve postoperative TMJ structure and function after fibular free flap reconstruction following mandibulectomy with condylectomy.

Pancreatic cancer is characterized by significant drug resistance,and despite continuous advancements in treatment regimens,the 5-year survival rate of patients remains low.The nuclear factor-κB(NF-κB)signaling pathway,frequently mutated in tumors,has been identified as a critical factor in triggering drug resistance.Multiple studies have demonstrated that strategies targeting NF-κB signaling transduction exhibit promising outcomes in pancreatic cancer treatment.Therefore,exploring the relationship between the NF-κB signaling pathway and drug resistance in pancreatic cancer has become a research hotspot in pancreatic cancer treatment.This review summarizes recent advances in the relationship between NF-κB signaling pathway and tumor drug resistance,as well as its role in pancreatic cancer treatment.Specifically,the mechanisms by which the NF-κB signaling pathway mediates drug resistance in pancreatic cancer are elaborated from two perspectives:chemotherapy and immunotherapy,aiming to provide insights for pancreatic cancer treatment and future research.

Objective To assess the efficacy of a novel inguinal tourniquet in healthy individuals and to investigate the relationship between localized inguinal compression and femoral artery blood flow occlusion.Methods A self-controlled study was conducted.From November 9 to November 30,2024,11 volunteers were recruited at the Third Medical Center of Chinese PLA General Hospital.Three compression methods--finger pressure,a novel groin tourniquet,and a SAM junction tourniquet(SJT)—were applied bilaterally to the inguinal region until distal blood flow signals disappeared.Each compression method was tested in 22 trials with a 5-minute interval between operations.Differences in hemostatic efficacy between bilateral inguinal regions and across compression methods were compared.Subsequently,the novel tourniquet was incrementally pressurized in 120 mmHg multiples using an integrated pressure device to analyze trends in popliteal artery blood flow velocity.Observational indicators included the internal pressure of the tourniquet pressurization device,peak systolic velocity(PSV)of popliteal artery,inguinal surface pressure magnitude,inguinal surface pressure distribution,and pain scores(assessed using a single-dimensional numerical rating scale).Results No statistically significant difference was observed in the minimum pressure required to occlude femoral artery blood flow bilaterally(P>0.05).The success rates of femoral artery blood flow occlusion at the inguinal region were 100%for the novel inguinal tourniquet,SJT,and finger pressure.The novel inguinal tourniquet induced the highest pain scores,ranging from 5 to 8.A significant reduction in PSV of popliteal artery was noted when the intra-tourniquet pressure reached 360 mmHg and 480 mmHg(P<0.05),with a 95%hemostasis efficacy observed within the range of 360-600 mmHg.No significant association was observed between the recovery of popliteal artery blood flow after limb movement and inguinal pressure distribution(P>0.05).The PSV of popliteal artery exhibited the strongest negative correlation with the average pressure within the inguinal compression area(r=-0.79,P<0.001),with a linear regression fitting line of y=69.69-0.13x(P<0.001,R2=0.58).Conclusions The novel inguinal tourniquet effectively occludes femoral artery blood flow within a pressure range of 360-600 mmHg,accompanied by moderate-to-severe pain.Its hemostatic mechanism mainly relies on increasing the mean pressure within the inguinal compression area.

Objective To investigate the effects and mechanisms of ubiquitin-associated domain-containing protein 2(UBAC2)mediated by m6A methylation modification on the invasion and migration abilities of colorectal cancer cells.Methods The GEPIA2.0 database was utilized to analyze the expression differences of UBAC2 mRNA between colorectal cancer tissues and adjacent normal tissues,as well as its expression in colorectal cancer tissues at different stages.The correlation between Wilms tumor 1-associated protein(WTAP)and UBAC2 expression was analyzed.The Kaplan-Meier plotter online tool was applied to analyze the correlation between UBAC2 and the overall survival rate of colorectal cancer patients.The RMVar and SRAMP databases were employed to predict potential m6A methylation modification sites in the UBAC2 gene.Quantitative real-time PCR(qRT-PCR)and Western blotting were performed to detect the expression levels of UBAC2 mRNA and protein in colorectal cancer cell lines.For UBAC2 knockdown experiments,SW480 cells were divided into control group(no treatment),sh-NC group(transfected with sh-NC negative control plasmid),and sh-UBAC2 group(transfected with sh-UBAC2 plasmid).For WTAP knockdown experiments,groups included control group(no treatment),si-NC group(transfected with negative control siRNA),and si-WTAP group(transfected with WTAP-targeting siRNA).For UBAC2 overexpression experiments,groups were control group(no treatment),si-WTAP group(transfected with pcDNA3.1 empty plasmid),and si-WTAP+OE-UBAC2 group(transfected with UBAC2 overexpression plasmid pcDNA3.1-UBAC2).Western blotting was used to detect the protein expression levels of UBAC2,WTAP,E-cadherin,N-cadherin,and Vimentin;qRT-PCR was applied to detect the expression level of UBAC2 mRNA;Transwell assays were conducted to assess cell invasion and migration abilities.MeRIP-qPCR was employed to detect the m6A methylation modification of UBAC2 mRNA;RIP-qPCR experiments were conducted to verify the binding of WTAP to UBAC2 mRNA.In nude mouse colorectal cancer lung metastasis experiments,groups included LV-sh-NC group(tail vein injection of SW480 cells stably infected with LV-sh-NC)and LV-sh-UBAC2 group(tail vein injection of SW480 cells stably infected with LV-sh-UBAC2).After 42 d of tumor-implantation in nude mice,lung tissues were harvested:the number of lung nodules observed by hematoxylin/eosin(HE)staining,and the expression level of Luc2 mRNA detected by qRT-PCR.Results GEPIA2.0 database analysis revealed that the expression level of UBAC2 mRNA in colorectal cancer tissues was significantly higher than that in adjacent normal tissues,and it gradually increased with the progression of tumor stage(P<0.05).The expression levels of UBAC2 mRNA and protein in multiple colorectal cancer cell lines were significantly higher than those in normal colonic epithelial cells(P<0.05).Compared with sh-NC group,sh-UBAC2 group showed significantly increased E-cadherin protein expression,significantly decreased N-cadherin and Vimentin protein expression,and significantly reduced number of invaded and migrated SW480 cells(P<0.05).GEPIA2.0 database analysis results indicated a positive correlation between WTAP and UBAC2 expression(r=0.24,P<0.001).Compared with si-NC group,si-WTAP group showed significantly decreased expression levels of WTAP and UBAC2 mRNA and protein in SW480 cells(P<0.05).MeRIP-qPCR results demonstrated that the m6A modification level of UBAC2 mRNA in si-WTAP group was significantly lower than that in si-NC group(P<0.05).RIP-qPCR further confirmed that WTAP could bind to UBAC2 mRNA.Compared with control group,si-WTAP group showed significantly increased E-cadherin protein expression and significantly decreased N-cadherin and Vimentin protein expression in SW480 cells(P<0.05);compared with si-WTAP group,si-WTAP+OE-UBAC2 group showed significantly decreased E-cadherin protein expression and significantly increased N-cadherin and Vimentin protein expression in SW480 cells(P<0.05).The number of lung nodules in LV-sh-UBAC2 group was significantly fewer than that in LV-sh-NC group,and the expression level of Luc2 mRNA in lung tissues was significantly lower than that in LV-sh-NC group(P<0.05).Conclusion UBAC2 mediated by m6A methylation modification can regulate the epithelial-mesenchymal transition(EMT)process in colorectal cancer cells,thereby affecting the invasion and migration abilities of colorectal cancer cells.