Objective: To analyze the causes and distribution characteristics of leukopenia in apheresis platelet donors, and to formulate effective pre-donation intervention measures. Methods: The data of apheresis platelet donors with leukopenia in Dongguan Central Blood Station during the entire year of 2021 were collected. Combined with the results of peripheral blood smear examination, the related factors that may cause leukopenia were analyzed. Results: There were 57 apheresis platelet donors with leukopenia in peripheral blood, with an incidence of 1.53% (57/3 726). The rate of leukopenia showed no significant difference between male and female apheresis platelet donors (χ =0.627, P>0.05), and was not related to the frequency of platelet donation (χ =1.48, P>0.05). However, there were statistically significant differences in the rate of leukopenia across seasons (χ =10.13, P<0.05), highly significant differences among different age groups (χ =22.98, P<0.001), and a significant association with the number of apheresis platelet donations (χ =7.80, P<0.05). Multivariate logistic regression analysis showed that age (36-55 years old), number of donations (≥26 times), and season (first and fourth quarters) were independent risk factors for leukopenia in apheresis platelet donors, while gender had no significant independent effect on leukopenia. Peripheral blood smear examination was performed on all apheresis platelet donors with leukopenia, and primary malignant hematological diseases infiltrated into peripheral blood were excluded. Among them, two cases of peripheral blood smear showed left shift of granulocyte nucleus with increased and thickened granules, whereas the other 55 cases only showed decreased peripheral blood nucleated cell counts without obvious morphological abnormalities. Conclusion: Leukopenia in apheresis platelet donors mainly occurred in young and middle-aged people and those with ≥26 donations, with high incidence in winter and spring, and more common in males. Blood routine examination combined with blood smear examination can facilitate the detection of conditions that are not suitable for blood donation, including hematological malignant diseases and infection-related leukopenia. Strengthening health consultation before blood donation is an important measure to identify blood donors with leukopenia.

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.

Acute kidney injury (AKI) is a prevalent and life-threatening clinical syndrome characterised by a rapid decline in renal function and diverse pathological etiologies. The condition has been demonstrated to be associated with elevated mortality rates and an increased risk of progression to chronic kidney disease. At present, clinicians depend heavily on conventional functional markers, such as serum creatinine and urine output, for the diagnosis and staging of the disease. It is evident that these conventional indicators characteristically manifest a considerable temporal delay and only undergo modification subsequent to considerable tissue damage. This severely restricts the timeframe for early detection and timely therapeutic intervention. Furthermore, standard markers fail to provide specific biological information regarding the underlying cellular injury mechanisms. The utilisation of advanced probe technologies in molecular imaging offers a robust alternative to overcome these inherent diagnostic limitations.This comprehensive review systematically evaluates recent progress in the design and application of two primary categories of molecular imaging tools for acute kidney disease, specifically reactive probes and enzyme-activated probes. Reactive probes are engineered to specifically interact with redox-active chemical species, including hydrogen peroxide, peroxynitrite, hypochlorous acid, and sulfur dioxide. Because oxidative stress constitutes a primary early event in acute renal tubular damage, these probes enable researchers and clinicians to visualize early cellular injury and radical accumulation well before global renal functional decline becomes evident. We discuss the application of these reactive probes across multiple imaging modalities including fluorescence imaging, magnetic resonance imaging (MRI), positron emission tomography (PET), and photoacoustic techniques. Photoacoustic imaging combines high spatial resolution with deep tissue penetration and has successfully demonstrated the ability to provide diagnostic alerts up to 12 h before any detectable rise in serum creatinine levels. Additionally, specific reactive probes have shown promising translational potential when tested by high-throughput screening in clinical human urine samples. Enzyme-activated probes target the specific catalytic activity of disease-relevant enzymes. These include well-documented renal tubular structural biomarkers such as NAG, GGT, and ALP, along with apoptosis-related caspases and specific nitroreductases. By responding only to enzymatic cleavage, these tools provide highly specific and pathology-directed imaging readouts. Recent structural design strategies in this field have advanced significantly beyond single-enzyme detection. Researchers are now focusing on sophisticated dual-target recognition to minimize background noise, multimodal integration to cross-validate imaging signals, and theranostic applications where probes simultaneously deliver diagnostic feedback and therapeutic agents to injured tissues. Nanotechnology serves as a fundamental enabler for realizing these advanced probe functions. By precisely optimizing nanoparticle parameters such as hydrodynamic size, surface charge, and targeting ligands, researchers can achieve amplified signal output, highly precise kidney delivery, and protection against premature degradation in the systemic circulation. For example, modifying surface charges can significantly enhance the active uptake of nanoprobes by damaged renal tubular epithelial cells.While preclinical probe development has progressed rapidly, moving these technologies into routine clinical practice remains a major challenge. We analyze the translational feasibility and current obstacles from biological, technological, and regulatory perspectives. Although biological targets such as KIM-1, FAP, and ALP have been validated in extensive patient cohorts, practical barriers severely limit their immediate clinical application. These obstacles involve complex changes in in vivo pharmacokinetics. During an acute injury episode, the extreme drop in the glomerular filtration rate alters probe clearance and can cause unwanted systemic accumulation or confusing background imaging signals. Other major hurdles include a lack of comprehensive long-term toxicity data and the absence of standardized manufacturing protocols to ensure batch-to-batch consistency. Future successful translation will require rigorous multi-center clinical studies to confirm the true diagnostic value of these probes over traditional markers. Researchers must also establish strict standardization of imaging procedures and comprehensive safety evaluations. Ultimately, this review provides a thorough reference framework for designing clinically translatable molecular probes and building a precision diagnostic imaging system for acute kidney injury.

Metachromatic leukodystrophy (MLD) is an inherited disease caused by a deficiency of the enzyme arylsulfatase A (ARSA). Lentivirus-modified autologous hematopoietic stem cell gene therapy (HSCGT) has recently been approved for clinical use in pre and early symptomatic children with MLD to increase ARSA activity. Unfortunately, this advanced therapy is not available for most patients with MLD who have progressed to more advanced symptomatic stages at diagnosis. Patients with late-onset juvenile MLD typically present with a slower neurological progression of symptoms and represent a significant burden to the economy and healthcare system, whereas those with early onset infantile MLD die within a few years of symptom onset. We conducted a pilot study to determine the safety and benefit of HSCGT in patients with postsymptomatic juvenile MLD and report preliminary results. The safety profile of HSCGT was favorable in this long-term follow-up over 9 years. The most common adverse events (AEs) within 2 months of HSCGT were related to busulfan conditioning, and all AEs resolved. No HSCGT-related AEs and no evidence of distorted hematopoietic differentiation during long-term follow-up for up to 9.6 years. Importantly, to date, patients have maintained remarkably improved ARSA activity with a stable disease state, including increased Functional Independence Measure (FIM) score and decreased magnetic resonance imaging (MRI) lesion score. This long-term follow-up pilot study suggests that HSCGT is safe and provides clinical benefit to patients with postsymptomatic juvenile MLD.
Humans ; Leukodystrophy, Metachromatic/genetics* ; Pilot Projects ; Genetic Therapy/methods* ; Hematopoietic Stem Cell Transplantation ; Male ; Follow-Up Studies ; Female ; Lentivirus/genetics* ; Child ; Child, Preschool ; Hematopoietic Stem Cells/metabolism* ; Cerebroside-Sulfatase/metabolism* ; Adolescent

Non-alcoholic fatty liver disease (NAFLD) is a metabolic disease characterized by abnormal deposition of lipid in hepatocytes. If not intervened in time, NAFLD may develop into liver fibrosis or liver cancer, and ultimately threatening life. NAFLD has complicated etiology and pathogenesis, and there are no effective therapeutic means and specific drugs. Currently, insulin sensitizers, lipid-lowering agents and hepatoprotective agents are often used for clinical intervention, but these drugs have obvious side effects, and their effectiveness and safety need to be further confirmed. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) plays a central role in maintaining energy homeostasis. Activated AMPK can enhance lipid degradation, alleviate insulin resistance (IR), suppress oxidative stress and inflammatory response, and regulate autophagy, thereby alleviating NAFLD. Natural herbal medicines have received extensive attention recently because of their regulatory effects on AMPK and low side effects. In this article, we reviewed the biologically active natural herbal medicines (such as natural herbal medicine formulas, extracts, polysaccharides, and monomers) that reported in recent years to treat NAFLD via regulating AMPK, which can serve as a foundation for subsequent development of candidate drugs for NAFLD.

OBJECTIVE: To investigate the feasibility and prognostic implications of assessing volume status during early fluid resuscitation in septic patients based on estimated plasma volume status (ePVS). METHODS: A prospective study was conducted. Patients with sepsis admitted to intensive care unit (ICU) of the First Affiliated Hospital of Kunming Medical University from March to December in 2023 were enrolled. The general information and laboratory indicators at ICU admission were recorded, and ePVS, sequential organ failure assessment (SOFA) score, acute physiology and chronic health status evaluation II (APACHE II) score were calculated. The vital signs, arterial blood gas analysis and volume status related indicators before liquid resuscitation (T0h) and 3 hours (T3h) and 6 hours (T6h) of fluid resuscitation were recorded. The diameter and variability of the inferior vena cava (IVC) were measured by ultrasound, and ePVS, percentage change value of estimated plasma volume status (ΔePVS%), difference in central venous-to-arterial partial pressure of carbon dioxide (Pcv-aCO₂), and lactate clearance rate (LCR) were calculated. Patients were divided into sepsis group and septic shock group based on the diagnosis at ICU admission, and septic patients were subdivided into survival group and death group based on their 28-day survival status. The differences in clinical data between the groups were compared. The correlation between ePVS or ΔePVS% and volume status related indicators during early liquid resuscitation was analyzed by Spearman rank sum correlation test. The predictive value of each variable for 28-day survival in patients with sepsis was analyzed by receiver operator characteristic curve (ROC curve), and 28-day death risk factors were analyzed by Logistic regression method. RESULTS: Fifty-four septic patients were enrolled in the final analysis, including 17 with sepsis and 37 with septic shock; 34 survived at 28 days and 20 died, with a 28-day survival rate of 63.0%. Compared with the sepsis group, the septic shock group had a lower venous ePVS at ICU admission [dL/g: 4.96 (3.67, 7.15) vs. 7.55 (4.36, 10.07), P < 0.05]. Compared with the death group, the survival group had higher T6h arterial and venous ΔePVS%, and albumin [Alb; T6h arterial ΔePVS% (%): 11.57% (-1.82%, 31.35%) vs. 0.48% (-5.67%, 6.02%), T6h venous ΔePVS%: 9.62% (3.59%, 25.75%) vs. 1.52% (-9.65%, 7.72%), Alb (g/L): 27.57±4.15 vs. 23.77±6.97, all P < 0.05], lower SOFA score, APACHE II score, AST, T0h Lac, and T3h and T6h norepinephrine dosage [SOFA score: 9.00 (8.00, 10.00) vs. 11.50 (9.25, 14.50), APACHE II score: 18.00 (14.75, 21.25) vs. 25.50 (21.00, 30.00), AST (U/L): 34.09 (23.20, 56.64) vs. 79.24 (25.34, 196.59), T0h Lac (mmol/L): 1.75 (1.40, 2.93) vs. 3.25 (2.33, 5.30), norepinephrine dosage (mg): 0.98 (< 0.01, 3.10) vs. 4.60 (1.05, 8.55) at T3h, 1.82 (0.38, 5.30) vs. 8.20 (2.80, 17.73) at T6h, all P < 0.05]. While there were no significantly differences in other basic data and ePVS at all of the time points before and after resuscitation between the two groups. Correlation analysis showed that T6h venous ePVS was significantly positively correlated with T6h IVC variability in septic patients (r = 0.360, P < 0.05), T0h arterial ePVS was significantly negatively correlated with T3h and T6h liquid intake volume (r₁ = -0.367, r₂ = -0.280, both P < 0.05), and venous ePVS at ICU admission was significantly positively correlated with NT-proBNP at ICU admission (r = 0.409, P < 0.05). T6h venous ΔePVS% was significantly positively correlated with T3h liquid intake volume and T6h LCR (r₁ = 0.286, r₂ = 0.286, both P < 0.05), and significantly negatively correlated with T6h urine volume and T6h change value of Pcv-aCO₂ (ΔPcv-aCO₂; r₁ = -0.321, r₂ = -0.371, both P < 0.05). ROC curve analysis showed that the area under the ROC curve (AUC) of T6h venous ΔePVS% for predicting 28-day survival in septic patients was 0.726 [95% confidence interval (95%CI) was 0.578-0.875, P = 0.006], with a sensitivity of 82.4%, a specificity of 60.0%, and an optimal cut-off value of 3.09%. Binary multifactorial Logistic regression analysis showed that an increase in T6h venous ΔePVS% was a protective factor for 28-day death in patients with sepsis on early fluid resuscitation [odds ratio (OR) = 0.900, 95%CI was 0.834-0.972, P = 0.007]. CONCLUSIONS ePVS may have potential for assessing the volume status of septic patients during early fluid resuscitation. The ΔePVS% during early fluid resuscitation may help to identify septic patients with a poor prognosis.
Humans ; Prognosis ; Fluid Therapy ; Sepsis/physiopathology* ; Prospective Studies ; Plasma Volume ; Intensive Care Units ; Resuscitation ; Male ; Female ; Middle Aged ; Shock, Septic/therapy*

AIM To explore the clinical effects of Jinfukang Oral Liquid combined with thymosin α1 on patients with non-small cell lung cancer due to Dual Deficiency of Qi and Yin.METHODS Seventy-five patients were randomly assigned into thymosin α1 group(15 cases)for 4-week administration,Jinfukang Oral Liquid group(30 cases)for 4-week administration,and combination group(30 cases)for 4-week administration.The changes in TCM clinical syndrome effects,immunity indices(CD3+T,Th,CTL,total NK,CD56dim CD16+NK,NKT,Treg,MDSC),lethality/inhibition ratios(CTL/Treg,total NK/Treg,NKT/Treg,CTL/MDSC,total NK/MDSC,NKT/MDSC)and FACT-L scores were detected.RESULTS The Jinfukang Oral Liquid group and combination group demonstrated higher total effective rates than the thymosin α1 group(P＜0.05).After the treatment,the Jinfukang Oral Liquid group and combination group displayed increased NKT(P＜0.05)and decreased MDSC(P＜0.05),which were more obvious than those in the thymosin α1 group(P＜0.05),and higher NKT was observable in the Jinfukang Oral Liquid group(P＜0.05);the Jinfukang Oral Liquid group and combination group displayed increased lethality/inhibition ratios(P＜0.05),among which NKT/Treg,CTL/MDSC,total NK/MDSC,NKT/MDSC were higher than those in the thymosin α1 group(P＜0.05),and higher CTL/MDSC,NKT/MDSC were observable in the Jinfukang Oral Liquid group(P＜0.05);the Jinfukang Oral Liquid group(except for physiological status,society and family status)and combination group(except for society and family status)displayed increased FACT-L scores(P＜0.05).CONCLUSION For the patients with non-small cell lung cancer due to Dual Deficiency of Qi and Yin,Jinfukang Oral Liquid single use or combined with thymosin α1 can enhance peripheral blood immune surveillance,inhibit immune escape,restore the balanced state of tumor immune responses,and improve TCM syndromes and life quality.

Objective:To investigate the epileptogenic networks of bilateral asymmetric tonic seizures (BATS) originating from the posterior insula using stereo-electroencephalography (SEEG).Methods:A retrospective analysis was performed. Among the epilepsy patients who underwent preoperative assessment and SEEG monitoring in the Epilepsy Department of Guangdong Sanjiu Brain Hospital from January 1, 2015 to July 1, 2024, 7 patients with insular epilepsy characterized by BATS originating from the posterior insula were selected based on anatomo-electro-clinical characteristics. The clinical characteristics, neuroimaging features, scalp EEG patterns, and SEEG recordings of the 7 patients were collected and analyzed. Via synchronously analyzing ictal semiology and electroanatomical propagation pathways shown by SEEG, the features of epileptogenic networks were elucidated. Results:Four patients had seizure onset from the dorsal-superior part of the left posterior insula, and 3 patients from the dorsal-superior part of the right posterior insula. The electroencephalographic characteristics of the seizure onset zones showed high consistency in these 7 patients: rhythmic spike or multiple spike discharges at the initial stage, and a low-amplitude rapid rhythm pattern subsequently. Totally, 3-10 seizures were recorded in each patient. Four patients experienced prodromal symptoms, including 3 patients with somatosensory symptoms (1 with chest and abdominal pain, 1 with contralateral facial numbness combined with throat constriction sensation, and 1 with contralateral limb numbness), and 1 patient with non-specific presentation (hugging family member before seizure). The seizure semiological evolution sequence was from prodrome to BATS, and then to secondary symptoms, with 3 patients exhibiting clustered spasms as secondary symptoms, and 4 patients showing eyelids and contralateral upper limb distal tonic-clonic manifestations as secondary symptoms. The epileptogenic networks followed a consistent pattern: the dorsal-superior part of the posterior insula leads to the middle-posterior part of the superior circular sulcus, to the ventral posterior insular and posterior circular sulcus, and then to the supplementary sensorimotor area (SSMA), and finally to the central sulcus, central region-vertex, and inferior parietal lobule. Only 2 patients had the anterior insular-involved epileptic brain networks, while the remaining 5 patients did not involve the anterior insular. During BATS, SEEG electrode contacts corresponding to the posterior insular, superior circular sulcus and SSMA exhibited low-amplitude rapid rhythm patterns.Conclusion:The seizures spread from the dorsal-superior part of the posterior insula to the middle-posterior part of the superior circular sulcus at the early stage of onset, and then connected with SSMA; these structures formed a epileptogenic brain network through abnormal synchronous discharge, which eventually led to BATS.

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.