The features analysis of hemoglobin expression on visual information transmission pathway in early stage of Alzheimer's disease.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized primarily by cognitive impairment. The motivation of this paper is to explore the impact of the visual information transmission pathway (V-H pathway) on AD, and the following feature were observed: Hemoglobin expression on the V-H pathway becomes dysregulated as AD occurs so as to the pathway becomes dysfunctional. According to the feature, the following conclusion was proposed: As AD occurs, abnormal tau proteins penetrate bloodstream and arrive at the brain regions of the pathway. Then the tau proteins or other toxic substances attack hemoglobin molecules. Under the attack, hemoglobin expression becomes more dysregulated. The dysfunction of V-H pathway has an impact on early symptoms of AD, such as spatial recognition disorder and face recognition disorder.

The clinical value of artificial intelligence in assisting junior radiologists in thyroid ultrasound: a multicenter prospective study from real clinical practice.

BACKGROUND: This study is to propose a clinically applicable 2-echelon (2e) diagnostic criteria for the analysis of thyroid nodules such that low-risk nodules are screened off while only suspicious or indeterminate ones are further examined by histopathology, and to explore whether artificial intelligence (AI) can provide precise assistance for clinical decision-making in the real-world prospective scenario. METHODS: In this prospective study, we enrolled 1036 patients with a total of 2296 thyroid nodules from three medical centers. The diagnostic performance of the AI system, radiologists with different levels of experience, and AI-assisted radiologists with different levels of experience in diagnosing thyroid nodules were evaluated against our proposed 2e diagnostic criteria, with the first being an arbitration committee consisting of 3 senior specialists and the second being cyto- or histopathology. RESULTS: According to the 2e diagnostic criteria, 1543 nodules were classified by the arbitration committee, and the benign and malignant nature of 753 nodules was determined by pathological examinations. Taking pathological results as the evaluation standard, the sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC) of the AI systems were 0.826, 0.815, 0.821, and 0.821. For those cases where diagnosis by the Arbitration Committee were taken as the evaluation standard, the sensitivity, specificity, accuracy, and AUC of the AI system were 0.946, 0.966, 0.964, and 0.956. Taking the global 2e diagnostic criteria as the gold standard, the sensitivity, specificity, accuracy, and AUC of the AI system were 0.868, 0.934, 0.917, and 0.901, respectively. Under different criteria, AI was comparable to the diagnostic performance of senior radiologists and outperformed junior radiologists (all P < 0.05). Furthermore, AI assistance significantly improved the performance of junior radiologists in the diagnosis of thyroid nodules, and their diagnostic performance was comparable to that of senior radiologists when pathological results were taken as the gold standard (all p > 0.05). CONCLUSIONS: The proposed 2e diagnostic criteria are consistent with real-world clinical evaluations and affirm the applicability of the AI system. Under the 2e criteria, the diagnostic performance of the AI system is comparable to that of senior radiologists and significantly improves the diagnostic capabilities of junior radiologists. This has the potential to reduce unnecessary invasive diagnostic procedures in real-world clinical practice.

Rhodojaponin VI ameliorates podocyte injury related with MDM2/Notch1 pathway in rat experimental membranous nephropathy.

AIM: Rhodojaponin VI (R-VI) is the key compound of Rhododendron molle G. Don (Ericaceae) (RM) with effective clinical application in rheumatoid arthritis and chronic glomerulonephritis. In our study, we tried to explore the effect of R-VI on the rat model of membranous nephropathy. METHODS: The rat model of passive heymann nephritis (PHN) was established by injecting sheep anti-rat Fx1A serum at a single dose through the tail. The rats were orally administered R-VI (0.02 mg/kg) or FK506 (1 mg/kg) 1 day before PHN induction, which was kept for 4 weeks. Urine and blood samples as well as kidney tissue were collected for analysis. C5b-9-induced human podocyte cell (HPC) was employed for experiments in vitro. RESULTS: R-VI could alleviate glomerulonephritis progression and podocyte injury in PHN rats, as indicated by the decreased proteinuria and the elevated level of albumin, accompanied with reduced immune deposits, reversed podocyte injury in the kidneys. Furthermore, R-VI suppressed murine double minute 2 (MDM2) expression without the alteration in the protein level of p53 and decreased Notch1 expression independent of Numb regulation. Pre-treatment with R-VI in C5b-9-induced HPC blocked MDM2/Notch1 signalling pathway. CONCLUSION: Thus, R-VI ameliorates podocyte injury in rats with PHN, which was probably related with MDM2/Notch1 signalling pathway.

Tracking changes in image-defined risk factors during neoadjuvant chemotherapy and their predictive value for surgical outcomes based on the International Neuroblastoma Surgical Report Form.

BACKGROUND: The capacity of presurgical image-defined risk factors (IDRFs) to predict secondary surgical outcomes in patients with neuroblastoma is controversial. METHODS: The International Neuroblastoma Surgical Report Form (INSRF) was employed to retrospectively collect the clinical data of 53 patients diagnosed with neuroblastoma at our hospital from April 2014 to April 2020. IDRFs were identified at the time of diagnosis and reassessed during the course of neoadjuvant chemotherapy. Various statistical tests were used to evaluate the correlation between IDRFs and secondary surgical outcomes. RESULTS: A total of 195 IDRFs were identified. Notably, by two courses of neoadjuvant chemotherapy, the number of "two body compartments," "intraspinal tumor extension," and "trachea-compressing" IDRFs decreased significantly (p = .001). The primary tumor volumes and the number of IDRFs decreased significantly by four courses of neoadjuvant chemotherapy, especially in "intraspinal tumor extension" IDRFs (p = .034). The median number of IDRF per patient was four (interquartile range [IQR]: 1-5) at diagnosis, which diminished to one (IQR: 1-3) subsequent to neoadjuvant chemotherapy. The presence of preoperative IDRFs was not associated with surgical complications (p = .286) or the extent of surgery (p = .188). However, the number of preoperative IDRFs linked to the extent of surgery (p = .002), not to operative complications (p = .669). Specifically, presurgery "renal vessel contact" IDRFs were predictive of surgical complications, while presurgery "infiltration of vital structures" IDRFs were associated with the extent of surgery. CONCLUSION: The number of IDRFs decreased significantly by four courses of neoadjuvant chemotherapy. The number and type of presurgery IDRFs may predict secondary surgical outcomes, surpassing the mere consideration of their presence or absence.

Analysis of the safety and efficacy of the self-pulling and latter transected technique in modified overlap anastomosis in total laparoscopic total gastrectomy.

Background: Laparoscopic total gastrectomy plus lymph node dissection is an effective treatment method for patients with gastric cancer. With the development and popularization of laparoscopic techniques in recent years, surgeons have become more skilled in laparoscopic techniques. Totally laparoscopic total gastrectomy (TLTG) has been developed; however, digestive tract reconstruction remains difficult, especially with anastomosis of the esophagus and jejunum. Using the self-pulling and latter transection (SPLT) method combined with a linear stapler has effectively solved the problem of narrow space in esophagojejunostomy. Here, we examined the safety and effectiveness of the SPLT technique in TLTG compared with SPLT with traditional esophagojejunostomy overlap anastomosis. Methods: We retrospectively analyzed all patients with gastric cancer admitted to the Department of Gastrointestinal Surgery of the Second Affiliated Hospital of Fujian Medical University from September 2020 to September 2023. In total, 158 patients met the inclusion criteria and were included. Patients were grouped according to whether the lower esophagus was transected after self-pulling. Patient demographics, tumor characteristics, surgical conditions, and postoperative results between the two groups were statistically analyzed. Results: A total of 158 patients were included in the study. All patients underwent TLTG and completed intracavitary anastomosis. There were 70 cases (44%) in the SPLT-Overlap group and 88 cases (56%) in the traditional overlap group. There was no significant difference in demographic and oncological characteristics between the two groups. The operation time (P = 0.002) and esophageal jejunum anastomosis time (P<0.001) were significantly shorter in the SPLT-Overlap group compared with the traditional overlap group. The intraoperative blood loss of the SPLT-Overlap group was 80.29 ± 36.36 ml, and the intraoperative blood loss of the traditional overlap group was 101.40 ± 46.68 ml. The difference was statistically significant (P=0.003). The SPLT-Overlap group also achieved a higher upper cutting edge (P =0.03). There was no significant difference between the two groups in terms of the incision size, postoperative hospital stay, time to first flatus, time to first liquid intake, drainage tube removal time, and esophagojejunal anastomotic diameter. There were 15 and 19 cases of short-term postoperative complications in the SPLT-Overlap and traditional Overlap groups, respectively. All patients received R0 resection, and no secondary surgery or death occurred. Conclusion: We applied SPLT to overlap anastomosis. Short-term, SPLT has good safety and feasibility in TLTG. It can effectively shorten the time of digestive tract reconstruction, simplify the reconstruction procedure, and make the digestive tract reconstruction simple and fast; at the same time, a safe cutting edge can be obtained.

Enhanced spontaneous radiation of quantum dots based on modulated anapole states in dielectric metamaterial.

Dielectric nanostructures exhibit low-loss electrical and magnetic resonance, making them ideal for quantum information processing. In this study, the periodic double-groove silicon nanodisk (DGSND) is used to support the anapole state. Based on the distribution properties of the electromagnetic field in anapole states, the anapoles are manipulated by cutting the dielectric metamaterial. Quantum dots (QDs) are used to stimulate the anapole and control the amplification of the photoluminescence signal within the QDs. By opening symmetrical holes in the long axis of the nanodisk in the dielectric metamaterial, the current distribution of Mie resonance can be adjusted. As a result, the toroidal dipole moment is altered, leading to an enhanced electric field (E-field) and Purcell factor. When the dielectric metamaterial is deposited on the Ag substrate separated by the silicon dioxide (SiO2) layer, the structure exhibits ultra-narrow perfect absorption with even higher E-field and Purcell factor enhancement compared to silicon (Si) nanodisks.

Reliability and validity of the Chinese version of the functional status score for the ICU (FSS-ICU) after translation and cross-cultural adaptation.

PURPOSE: The Functional Status Score for the Intensive Care Unit (FSS-ICU) is designed to assess the physical functional status of patients in ICU settings. This study aimed to translate and culturally adapt the FSS-ICU for the Chinese context and to evaluate its reliability and validity. METHODS: Following Beaton's translation model, the original FSS-ICU was subjected to forward translation, back-translation, and synthesis. After cultural adaptation and preliminary testing, the Chinese version of the FSS-ICU was established, and then two rehabilitation therapists assessed the functional status of 51 ICU patients using this scale, evaluating its reliability and validity. RESULTS: The Chinese version of the FSS-ICU exhibits excellent internal consistency with a Cronbach's alpha coefficient of 0.934. The inter-rater and intra-rater correlation coefficients are 0.995 and 0.997, respectively. Both item-level and scale-level content validity indices are 1.00. The FSS-ICU demonstrates good convergent validity with other physical function assessment tools (Medical Research Council Sum-Score, grip strength, the Intensive Care Unit Mobility Scale), with |rs| values all above 0.5, and satisfactory discriminant validity with non-physical function assessment indicators (body mass index, blood glucose), with |rs| values all below 0.2. Additionally, it demonstrated no ceiling or floor effects. CONCLUSION: The Chinese FSS-ICU, demonstrating strong reliability and validity, can serve as an effective assessment tool for physical function in ICU patients.

The Chinese version of the Functional Status Score for the ICU (FSS-ICU) is a robust tool for assessing physical function in ICU settings in China, characterized by high reliability and validity.As in other countries, the FSS-ICU may be used as part of clinical care and clinical research when evaluating ICU patients' physical status.This instrument facilitates tracking the progression of physical capabilities and tailoring targeted rehabilitation plans.

Improving the Solubility and Bioavailability of Progesterone Cocrystals with Selected Carboxylic Acids.

Progesterone (PROG) is a natural steroid hormone with low solubility and high permeability that belongs to biopharmaceutics classification system class II. In this study, novel pharmaceutical cocrystals of PROG were successfully prepared by solvent evaporation or a liquid-assisted grinding process aimed at enhancing its solubility and bioavailability. The cocrystal formers selected based on crystal engineering principles were carboxylic acids, namely, 4-formylbenzeneboronic acid (BBA), isophthalic acid (IPA), and 3-nitrophthalic acid (NPA). The cocrystal structures were characterized using multiple techniques. Single-crystal X-ray diffraction results showed that the carbonyl group, acting as a hydrogen bond acceptor, was pivotal in the cocrystal network formation, with C-H···O interactions further stabilizing the crystals. The cocrystals exhibited improved solubility and dissolution profiles in vitro, with no significant changes in hygroscopicity. The parallel artificial membrane permeability assay (PAMPA) models indicated that the cocrystals retained PROG's high permeability. Pharmacokinetic studies in Sprague-Dawley rats revealed that all cocrystals increased PROG exposure, with AUC(0~∞) values for PROG-BBA, PROG-IPA, and PROG-NPA being 742.59, 1201.72 and 442.67 h·ng·mL-1, respectively. These values are substantially higher compared to free PROG, which had an AUC(0~∞) of 301.48 h·ng·mL-1. Notably, PROG-IPA provided the highest AUC improvement, indicating a significant enhancement in bioavailability. Collectively, the study concludes that the cocrystal approach is a valuable strategy for optimizing the physicochemical properties and oral bioavailability of PROG, with potential implications for the development of other poor water-soluble drugs.

The role of locoregional surgery in de novo stage IV breast cancer: A meta-analysis of randomized controlled trials.

BACKGROUND: We performed an updated meta-analysis to explore the value of locoregional surgery in de novo stage IV breast cancer patients. METHODS: A literature search was conducted to identify randomized controlled trials comparing primary tumor resection with systemic therapy in de novo stage IV breast cancer. The hazard ratio (HR) of overall survival (OS), local relapse-free survival (LRFS), and distant relapse-free survival (DRFS) were estimated and pooled. RESULTS: Six studies were eligible, including a total of 1368 patients. Both OS (HR = 0.86; 95 %CI: 0.77-0.96; p = 0.01; I2 = 45 %) and LRFS (HR = 0.35; 95 %CI: 0.20-0.62; p = 0.0003; I2 = 83 %) were significantly improved with locoregional surgery compared with systemic therapy alone. There was no significant difference in terms of DRFS (HR = 0.96; 95 %CI: 0.41-2.22; p = 0.92; I2 = 86 %). The OS benefit was more pronounced in hormone receptor-positive patients (HR = 0.79; p = 0.003) and HER2-negative patients (HR = 0.80; p = 0.003). CONCLUSIONS: This study demonstrated that locoregional surgery conferred significant OS and LRFS benefits in de novo stage IV breast cancer patients and may serve as an alternative choice for selected patients.

Effect of Boron Content in LiOH Solutions on the Corrosion Behavior of Zr-Sn-Nb Alloy.

In pressurized water reactors, LiOH may be concentrated in some areas, leading to the accelerated corrosion of fuel claddings. Injecting boric acid into primary coolants can mitigate the accelerated corrosion effect of LiOH on Zircaloys, but the effects of boron content on the corrosion behavior of the Zr-Sn-Nb alloy are still unknown. This work focused on the corrosion and hydrogen absorption behavior at 360 °C/18.6 MPa in 100 mg/kg LiOH solutions with 0 mg/kg, 50 mg/kg, and 200 mg/kg boron contents for up to 510 days, aiming to study the effect of boron content on corrosion resistance in LiOH solutions. Corrosion kinetics, microstructures of oxide films, hydrogen absorption concentrations and hydride morphology were obtained after the test. The results show that injecting boron in LiOH solutions can significantly reduce the corrosion weight gain, hydrogen concentration, and hydrogen length of Zr-Sn-Nb alloys, that is, improving corrosion resistance effectively. During the oxidation of the Zr-Sn-Nb alloy, B3+ and Li+ incorporate in oxide films. The incorporation of Li+ may lead to the generation of oxygen vacancies, which can carry oxygen from the solutions to O/M interface, accelerating corrosion. The incorporation of B3+ in oxide films will slow down the oxidation of Zr-Sn-Nb alloys by reducing the oxygen vacancies caused by Li+ aggregation.

MDM2 accelerated renal senescence via ubiquitination and degradation of HDAC1.

Senescence, an intricate and inevitable biological process, characterized by the gradual loss of homeostasis and declining organ functions. The pathological features of cellular senescence, including cell cycle arrest, metabolic disruptions, and the emergence of senescence-associated secretory phenotypes (SASP), collectively contribute to the intricate and multifaceted nature of senescence. Beyond its classical interaction with p53, murine double minute gene 2 (MDM2), traditionally known as an E3 ubiquitin ligase involved in protein degradation, plays a pivotal role in cellular processes governing senescence. Histone deacetylase (HDAC), a class of histone deacetylases mainly expressed in the nucleus, has emerged as a critical contributor to renal tissues senescence. In this study we investigated the interplay between MDM2 and HDAC1 in renal senescence. We established a natural aging model in mice over a 2-year period that was verified by SA-ß-GAL staining and increased expression of senescence-associated markers such as p21, p16, and TNF-α in the kidneys. Furthermore, we showed that the expression of MDM2 was markedly increased, while HDAC1 expression underwent downregulation during renal senescence. This phenomenon was confirmed in H2O2-stimulated HK2 cells in vitro. Knockout of renal tubular MDM2 alleviated renal senescence in aged mice and in H2O2-stimulated HK2 cells. Moreover, we demonstrated that MDM2 promoted renal senescence by orchestrating the ubiquitination and subsequent degradation of HDAC1. These mechanisms synergistically accelerate the aging process in renal tissues, highlighting the intricate interplay between MDM2 and HDAC1, underpinning the age-related organ function decline.

Tannic acid inhibits Escherichia coli biofilm formation and underlying molecular mechanisms: Biofilm regulator CsgD.

Biofilms often engender persistent infections, heightened antibiotic resistance, and the recurrence of infections. Therefor, infections related to bacterial biofilms are often chronic and pose challenges in terms of treatment. The main transcription regulatory factor, CsgD, activates csgABC-encoded curli to participate in the composition of extracellular matrix, which is an important skeleton for biofilm development in enterobacteriaceae. In our previous study, a wide range of natural bioactive compounds that exhibit strong affinity to CsgD were screened and identified via molecular docking. Tannic acid (TA) was subsequently chosen, based on its potent biofilm inhibition effect as observed in crystal violet staining. Therefore, the aim of this study was to investigate the specific effects of TA on the biofilm formation of clinically isolated Escherichia coli (E. coli). Results demonstrated a significant inhibition of E. coli Ec032 biofilm formation by TA, while not substantially affecting the biofilm of the ΔcsgD strain. Moreover, deletion of the csgD gene led to a reduction in Ec032 biofilm formation, alongside diminished bacterial motility and curli synthesis inhibition. Transcriptomic analysis and RT-qPCR revealed that TA repressed genes associated with the csg operon and other biofilm-related genes. In conclusion, our results suggest that CsgD is one of the key targets for TA to inhibit E. coli biofilm formation. This work preliminarily elucidates the molecular mechanisms of TA inhibiting E. coli biofilm formation, which could provide a lead structure for the development of future antibiofilm drugs.

Stimulator of interferon genes mediated immune senescence reveals the immune microenvironment and prognostic characteristics of bladder cancer.

Background: Studies have shown that the stimulator of interferon genes (STING) is critical in tumorigenesis, and development. This study aimed to investigate the immune profile and prognostic significance of STING-mediated immune senescence in bladder cancer (BLCA). Methods: We identified differential genes between tumor and normal tissue based on the Cancer Genome Atlas database, and used consensus clustering to identify BLCA subtypes. The genes most associated with overall survival were screened by further analysis and used to construct risk models. Then, comparing the immune microenvironment, tumor mutational load (TMB), and microsatellite instability (MSI) scores between different risk groups. Eventually, a nomogram was constructed based on clinical information and risk scores. The model was validated using receiver operating curves (ROC) and calibration plots. Results: We identified 160 differential genes, including 13 genes most associated with prognosis. Three subtypes of bladder cancer with different clinical and immunological features were identified. Immunotherapy was more likely to benefit the low-risk group, which had higher TMB and MSI scores. The nomogram was found to be highly predictive based on ROC analysis and calibration plots. Conclusion: The risk model and nomogram not only predict the prognosis of BLCA patients but also can guide the treatment.

FGF21 attenuates neuroinflammation following subarachnoid hemorrhage through promoting mitophagy and inhibiting the cGAS-STING pathway.

BACKGROUND: Subarachnoid hemorrhage (SAH) represents a form of cerebrovascular event characterized by a notable mortality and morbidity rate. Fibroblast growth factor 21 (FGF21), a versatile hormone predominantly synthesized by the hepatic tissue, has emerged as a promising neuroprotective agent. Nevertheless, the precise impacts and underlying mechanisms of FGF21 in the context of SAH remain enigmatic. METHODS: To elucidate the role of FGF21 in inhibiting the microglial cGAS-STING pathway and providing protection against SAH-induced cerebral injury, a series of cellular and molecular techniques, including western blot analysis, real-time polymerase chain reaction, immunohistochemistry, RNA sequencing, and behavioral assays, were employed. RESULTS: Administration of recombinant fibroblast growth factor 21 (rFGF21) effectively mitigated neural apoptosis, improved cerebral edema, and attenuated neurological impairments post-SAH. Transcriptomic analysis revealed that SAH triggered the upregulation of numerous genes linked to innate immunity, particularly those involved in the type I interferon (IFN-I) pathway and microglial function, which were notably suppressed upon adjunctive rFGF21 treatment. Mechanistically, rFGF21 intervention facilitated mitophagy in an AMP-activated protein kinase (AMPK)-dependent manner, thereby preventing mitochondrial DNA (mtDNA) release into the cytoplasm and dampening the activation of the DNA-sensing cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway. Conditional knockout of STING in microglia markedly ameliorated the inflammatory response and mitigated secondary brain injuries post-SAH. CONCLUSION: Our results present the initial evidence that FGF21 confers a protective effect against neuroinflammation-associated brain damage subsequent to SAH. Mechanistically, we have elucidated a novel pathway by which FGF21 exerts this neuroprotection through inhibition of the cGAS-STING signaling cascade.

Effect of baicalin on eradicating biofilms of bovine milk derived Acinetobacter lwoffii.

BACKGROUND: Acinetobacter lwoffii (A.lwoffii) is a serious zoonotic pathogen that has been identified as a cause of infections such as meningitis, bacteremia and pneumonia. In recent years, the infection rate and detection rate of A.lwoffii is increasing, especially in the breeding industry. Due to the presence of biofilms, it is difficult to eradicate and has become a potential super drug-resistant bacteria. Therefore, eradication of preformed biofilm is an alternative therapeutic action to control A.lwoffii infection. The present study aimed to clarify that baicalin could eradicate A.lwoffii biofilm in dairy cows, and to explore the mechanism of baicalin eradicating A.lwoffii. RESULTS: The results showed that compared to the control group, the 4 MIC of baicalin significantly eradicated the preformed biofilm, and the effect was stable at this concentration, the number of viable bacteria in the biofilm was decreased by 0.67 Log10CFU/mL. The total fluorescence intensity of biofilm bacteria decreased significantly, with a reduction rate of 67.0%. There were 833 differentially expressed genes (367 up-regulated and 466 down-regulated), whose functions mainly focused on oxidative phosphorylation, biofilm regulation system and trehalose synthesis. Molecular docking analysis predicted 11 groups of target proteins that were well combined with baicalin, and the content of trehalose decreased significantly after the biofilm of A.lwoffii was treated with baicalin. CONCLUSIONS: The present study evaluated the antibiofilm potential of baicalin against A.lwoffii. Baicalin revealed strong antibiofilm potential against A.lwoffii. Baicalin induced biofilm eradication may be related to oxidative phosphorylation and TCSs. Moreover, the decrease of trehalose content may be related to biofilm eradication.

Decarboxylation Mechanism of iso-Orotate Decarboxylase Revisited.

iso-Orotate decarboxylase (IDCase), which is involved in the thymidine salvage pathway, has attracted considerable interest owing to its chemical similarity to a hypothetical DNA decarboxylase in mammals. Although valuable insights into the active DNA demethylation of 5-methyl-cytosine can be obtained from the decarboxylation mechanism of 5-carboxyl-uracil (5caU) catalyzed by IDCase, this mechanism remains under debate. In this study, the catalytic mechanism of 5caU decarboxylation by IDCase was studied using hybrid quantum mechanics/molecular mechanics (QM/MM) methodologies and density functional theory (DFT) calculations with a truncated model. The calculations supported a mechanism involving three sequential stages: activation of the 5caU substrate via proton transfer from an arginine (R262') to the carboxyl group of 5caU, formation of a tetrahedral intermediate, and decarboxylation of the tetrahedral intermediate to generate uracil as the product. The reaction pathways and structures obtained using the QM/MM and DFT methods coincided with each other. These simulations provided detailed insights into the unique mechanism of IDCase, clarifying various unresolved issues, such as the critical role of R262'. In addition, aspartate D323 was found to act as a general base in the tetrahedral intermediate formation step and a general acid in the later C-C bond cleavage step.

Functional mechanism of hypoxia-like conditions mediating resistance to ferroptosis in cervical cancer cells by regulating KDM4A SUMOylation and the SLC7A11/GPX4 pathway.

The discovery of ferroptosis has unveiled new perspectives for cervical cancer (CC) management. We elucidated the functional mechanism of hypoxia-like conditions in CC cell ferroptosis resistance. CC cells were subjected to normoxia or hypoxia-like conditions, followed by erastin treatment to induce ferroptosis. The assessment of cell viability/ferroptosis resistance was performed by MTT assay/Fe2+, MDA, and glutathione measurement by colorimetry. KDM4A/SUMO1/Ubc9/SENP1 protein levels were determined by Western blot. Interaction and binding sites between KDM4A and SUMO1 were analyzed and predicted by immunofluorescence/co-immunoprecipitation and GPS-SUMO 1.0 software, with the target relationship verified by mutation experiment. SLC7A11/GPX4/H3K9me3 protein levels, and H3K9me3 level in the SLC7A11 gene promoter region were determined by RT-qPCR and Western blot/chromatin immunoprecipitation. H3H9me3/SLC7A11/GPX4 level alterations, and ferroptosis resistance after KDM4A silencing or KDM4A K471 mutation were assessed. Hypoxia-like conditions increased CC cell ferroptosis resistance and KDM4A, SUMO1, and Ubc9 protein levels, while it decreased SENP1 protein level. KDM4A and SUMO1 were co-localized in the nucleus, and hypoxia-like conditions promoted their interaction. Specifically, the K471 locus of KDM4A was the main locus for SUMO1ylation. Hypoxia-like conditions up-regulated SLC7A11 and GPX4 expression levels and decreased H3K9me3 protein level and H3K9me3 abundance in the SLC7A11 promoter region. KDM4A silencing or K471 locus mutation resulted in weakened interaction between KDM4A and SUMO1, elevated H3K9me3 levels, decreased SLC7A11 expression, ultimately, a reduced CC cell ferroptosis resistance. CoCl2-stimulated hypoxia-like conditions enhanced SUMO1 modification of KDM4A at the K471 locus specifically, repressed H3K9me3 levels, and up-regulated SLC7A11/GPX4 to enhance CC cell ferroptosis resistance.