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.

AIM To evaluate the quality of Rubi Fructus.METHODS UPLC-Q-TOF-MS/MS was adopted in the component identification,after which the HPLC fingerprints were established,cluster analysis,principal component analysis and orthogonal partial least squares discriminant analysis were used for chemical pattern recognition.and the contents of chlorogenic acid,ferulic acid,ellagic acid,isoquercitrin,kaempferol-3-O-rutinoside,astragalin,tiliroside quercetin,kaempferol were determined.RESULTS Total 34 constituents were identified.There were 19 common peaks in the fingerprints for 31 batches of medicinal materials with the similarities of more than 0.8.Wild varieties and cultivated varieties,and medicinal materials from different producing areas could be distinguished;4 principal components demonstrated the accumulative variance contribution rate of 84.142％;8 differential components were screened,2 of which were ellagic acid and astragalin.Ellagic acid and astragalin displayed higher contents in the wild varieties than those in the cultivated varieties(P＜0.05,P＜0.01).CONCLUSION UPLC-Q-TOF-MS/MS,HPLC fingerprints combined with content determination can be used for the quality control of Rubi Fructus.

OBJECTIVE: This study aimed to explore the association between body mass index (BMI) and mortality based on the 10-year population-based multicenter prospective study. METHODS: A general population-based multicenter prospective study was conducted at four sites in rural China between 2013 and 2023. Multivariate Cox proportional hazards models and restricted cubic spline analyses were used to assess the association between BMI and mortality. Stratified analyses were performed based on the individual characteristics of the participants. RESULTS: Overall, 19,107 participants with a sum of 163,095 person-years were included and 1,910 participants died. The underweight (< 18.5 kg/m ²) presented an increase in all-cause mortality (adjusted hazards ratio [ aHR] = 2.00, 95% confidence interval [ CI]: 1.66-2.41), while overweight (≥ 24.0 to < 28.0 kg/m ²) and obesity (≥ 28.0 kg/m ²) presented a decrease with an aHR of 0.61 (95% CI: 0.52-0.73) and 0.51 (95% CI: 0.37-0.70), respectively. Overweight ( aHR = 0.76, 95% CI: 0.67-0.86) and mild obesity ( aHR = 0.72, 95% CI: 0.59-0.87) had a positive impact on mortality in people older than 60 years. All-cause mortality decreased rapidly until reaching a BMI of 25.7 kg/m ² ( aHR = 0.95, 95% CI: 0.92-0.98) and increased slightly above that value, indicating a U-shaped association. The beneficial impact of being overweight on mortality was robust in most subgroups and sensitivity analyses. CONCLUSION This study provides additional evidence that overweight and mild obesity may be inversely related to the risk of death in individuals older than 60 years. Therefore, it is essential to consider age differences when formulating health and weight management strategies.
Humans ; Body Mass Index ; China/epidemiology* ; Male ; Female ; Middle Aged ; Prospective Studies ; Rural Population/statistics & numerical data* ; Aged ; Follow-Up Studies ; Adult ; Mortality ; Cause of Death ; Obesity/mortality* ; Overweight/mortality*

AIM To evaluate the quality of Rubi Fructus.METHODS UPLC-Q-TOF-MS/MS was adopted in the component identification,after which the HPLC fingerprints were established,cluster analysis,principal component analysis and orthogonal partial least squares discriminant analysis were used for chemical pattern recognition.and the contents of chlorogenic acid,ferulic acid,ellagic acid,isoquercitrin,kaempferol-3-O-rutinoside,astragalin,tiliroside quercetin,kaempferol were determined.RESULTS Total 34 constituents were identified.There were 19 common peaks in the fingerprints for 31 batches of medicinal materials with the similarities of more than 0.8.Wild varieties and cultivated varieties,and medicinal materials from different producing areas could be distinguished;4 principal components demonstrated the accumulative variance contribution rate of 84.142％;8 differential components were screened,2 of which were ellagic acid and astragalin.Ellagic acid and astragalin displayed higher contents in the wild varieties than those in the cultivated varieties(P＜0.05,P＜0.01).CONCLUSION UPLC-Q-TOF-MS/MS,HPLC fingerprints combined with content determination can be used for the quality control of Rubi Fructus.

AIM To screen the material basis for Rhei Radix et Rhizoma on improving human umbilical vein endothelial cell(HUVECs)injury before and after carbonization.METHODS The HPLC fingerprints were established,after which difference analysis was performed by orthogonal partial least squares discriminant analysis.The LPS-induced HUVECs injury model was established,then NO,MDA levels and SOD activity were detected.Gray correlation analysis and partial least squares regression were adopted in the investigation of spectrum-effect relationship,and active constituents were screened.RESULTS There were 22 and 20 common peaks in the fingerprints for 17 batches of raw products and carbonized products,respectively,along with the similarities of more than 0.8.Twelve main difference components were observable,among which gallic acid,5-hydroxymethylfurfural,catechin,aloe rhodopsin-8-O-β-D-glucoside,rhubarbic acid-8-O-β-D-glucoside and sennosides A were identified.The carbonized products demonstrated stronger effect on improving HUVECs injury than the raw product.The correlations of common peaks were more than 0.5 in the fingerprints for raw products and carbonized products,and peaks 3,5,11,12,15,19,23 exhibited significant effects on their efficacy(VIP values＞1).CONCLUSION This accurate,reliable and reproducible method can provide a basis for clarifying the material basis for hemostatic efficacy of Rhei Radix et Rhizoma and its carbonized product.

AIM To screen the material basis for Rhei Radix et Rhizoma on improving human umbilical vein endothelial cell(HUVECs)injury before and after carbonization.METHODS The HPLC fingerprints were established,after which difference analysis was performed by orthogonal partial least squares discriminant analysis.The LPS-induced HUVECs injury model was established,then NO,MDA levels and SOD activity were detected.Gray correlation analysis and partial least squares regression were adopted in the investigation of spectrum-effect relationship,and active constituents were screened.RESULTS There were 22 and 20 common peaks in the fingerprints for 17 batches of raw products and carbonized products,respectively,along with the similarities of more than 0.8.Twelve main difference components were observable,among which gallic acid,5-hydroxymethylfurfural,catechin,aloe rhodopsin-8-O-β-D-glucoside,rhubarbic acid-8-O-β-D-glucoside and sennosides A were identified.The carbonized products demonstrated stronger effect on improving HUVECs injury than the raw product.The correlations of common peaks were more than 0.5 in the fingerprints for raw products and carbonized products,and peaks 3,5,11,12,15,19,23 exhibited significant effects on their efficacy(VIP values＞1).CONCLUSION This accurate,reliable and reproducible method can provide a basis for clarifying the material basis for hemostatic efficacy of Rhei Radix et Rhizoma and its carbonized product.

Objective To evaluate the bioequivalence and safety of ezetimibe tablets in healthy Chinese subjects.Methods The study was designed as a single-center,randomized,open-label,two-period,two-way crossover,single-dose trail.Subjects who met the enrollment criteria were randomized into fasting administration group and postprandial administration group and received a single oral dose of 10 mg of the subject presparation of ezetimibe tablets or the reference presparation per cycle.The blood concentrations of ezetimibe and ezetimibe-glucuronide conjugate were measured by high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS),and the bioequivalence of the 2 preparations was evaluated using the WinNonlin 7.0 software.Pharmacokinetic parameters were calculated to evaluate the bioequivalence of the 2 preparations.The occurrence of all adverse events was also recorded to evaluate the safety.Results The main pharmacokinetic parameters of total ezetimibe in the plasma of the test and the reference after a single fasted administration:Cmax were(118.79±35.30)and(180.79±51.78)nmol·mL-1;tmax were 1.40 and 1.04 h;t1/2 were(15.33±5.57)and(17.38±7.24)h;AUC0-t were(1 523.90±371.21)and(1 690.99±553.40)nmol·mL-1·h;AUC0-∞ were(1 608.70±441.28),(1 807.15±630.00)nmol·mL-1·h.The main pharmacokinetic parameters of total ezetimibe in plasma of test and reference after a single meal:Cmax were(269.18±82.94)and(273.93±87.78)nmol·mL-1;Tmax were 1.15 and 1.08 h;t1/2 were(22.53±16.33)and(16.02±5.84)h;AUC0_twere(1 463.37±366.03),(1 263.96±271.01)nmol·mL-1·h;AUC0-∞ were(1 639.01±466.53),(1 349.97±281.39)nmol·mL-1·h.The main pharmacokinetic parameters Cmax,AUC0-tand AUC0-∞ of the two preparations were analyzed by variance analysis after logarithmic transformation.In the fasting administration group,the 90％CI of the log-transformed geometric mean ratios were within the bioequivalent range for the remaining parameters in the fasting dosing group,except for the Cmax of ezetimibe and total ezetimibe,which were below the lower bioequivalent range.The Cmax of ezetimibe,ezetimibe-glucuronide,and total ezetimibe in the postprandial dosing group was within the equivalence range,and the 90％CI of the remaining parameters were not within the equivalence range for bioequivalence.Conclusion This test can not determine whether the test preparation and the reference preparation of ezetimibe tablets have bioequivalence,and further clinical trials are needed to verify it.

A liquid chromatography-tandem mass spectrometry method was established and validated for determining the concentrations of costunolide(CO), piperine(PI), agarotetrol(AG), glycyrrhizic acid(GL), vanillic acid(VA), and glycyrrhetinic acid(GA) in rat plasma. This method was then applied to the toxicokinetic study of these six compounds in rats with chronic cerebral ischemia(CCI) following multiple oral doses of Zhachong Shisanwei Pills. Finally, the effects of continuous multiple-dose administration of Zhachong Shisanwei Pills on the liver of CCI rats were investigated. The results showed that after oral administration of different doses of Zhachong Shisanwei Pills, the in vivo exposure of AG, VA, and GA was relatively high, with AUC_(0-∞) values ranging from 604.0-2 494.2, 1 305.4-4 634.5, and 2 177.5-4 045.7 h·ng·mL~(-1), respectively, while the exposure of CO, PI, and GL was relatively low, with AUC_(0-∞) values ranging from 37.8-238.2, 2.4-17.0, and 146.9-408.5 h·ng·mL~(-1), respectively. The C_(max) and AUC_(0-∞) of the six compounds were positively correlated with the administered dose. The T_(max) of PI and AG ranged from 0.3 to 2.0 h, their T_(1/2) ranged from 0.8 to 2.9 h, and their mean residence time(MRT) ranged from 1.0 to 3.7 h. The T_(max) of GL and VA was shorter(0.4-1.9 h), while their T_(1/2)(2.6-5.9 h) and MRT(2.5-8.5 h) were longer. Both CO and GA exhibited a bimodal phenomenon, with T_(max) ranging from 1.6 to 6.6 h, T_(1/2) ranging from 2.8 to 7.7 h, and MRT ranging from 4.1 to 12.9 h. Liver histopathology after 28 days of continuous multiple-dose administration of Zhachong Shisanwei Pills showed that the liver tissue remained normal at a low dose(crude drug 0.8 g·kg~(-1), approximately 5 times the clinical equivalent dose). However, as the dose increased(crude drug 1.1-3.0 g·kg~(-1), 6.9-18.8 times the clinical equivalent dose), varying degrees of liver damage were observed. Blood biochemical tests revealed no significant changes in the serum levels of alanine aminotransferase(ALT), aspartate aminotransferase(AST), alkaline phosphatase(ALP), and total bile acid(TBA) in CCI rats from administration groups 1 to 3(crude drug 0.8, 1.1, 1.5 g·kg~(-1)). However, ALT, AST, ALP, and TBA levels in groups 4 and 5(crude drug 2.1, 3.0 g·kg~(-1)) showed significant increases. This study preliminarily elucidated the toxicokinetic characteristics of the six compounds in Zhachong Shisanwei Pills and their effects on liver tissue in CCI rats, providing data as a reference for clinical use.
Animals ; Tandem Mass Spectrometry/methods* ; Rats ; Drugs, Chinese Herbal/toxicity* ; Male ; Rats, Sprague-Dawley ; Brain Ischemia/blood* ; Chromatography, Liquid/methods* ; Polyunsaturated Alkamides/blood* ; Piperidines/toxicity* ; Benzodioxoles/toxicity* ; Alkaloids/blood* ; Liquid Chromatography-Mass Spectrometry

Objective To establish a method to identify an unknown substance based on the combined use of gas chromatography-quadrupole time-of-flight mass spectrometry(GC-QTOF-MS),ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry(UPLC-Q/Orbitrap HRMS)and nuclear magnetic resonance(NMR)techniques.Methods The unknown substance was dissolved in methanol and was detected by GC-QTOF-MS and UPLC-Q/Orbitrap HRMS,and was dissolved in methanol-d4 to be detected by NMR.Results The main characteristics ion peaks of components with retention time of 9.67 min in GC-QTOF-MS measured were 84.080 8,110.999 7,128.107 0(base peak),138.994 7,etc.The protonated molecular ion peak m/z in UPLC-Q/Orbitrap HRMS was 268.109 3.It was inferred that the unknown substance was an analog of the syn-thetic cathinone substance 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one(MTMP)by comparing the mass spectrum information and molecular structure of MTMP.NMR analysis confirmed it as a novel N-morpholine substituted synthetic cathinone substance 1-(4-chlorophenyl)-2-methyl-2-morpholinopropan-1-one(CMMP).Conclusion The method established in this study can be used for structural confirmation of CMMP.