RESUMO
RATIONALE: Splenic abscess is relatively rare in clinical practice as an invasive disease. However, during the continuous prevalence of coronavirus disease 2019 (COVID-19), the incidence rate of splenic abscess showed an upward trend. However, because the etiology of splenic abscess is not specific, it is easy to be covered by the respiratory symptoms of COVID-19, resulting in omission or delay in diagnosis. If splenic abscesses cannot be treated in a timely manner, the mortality rate can reach 100%. Therefore, it is important to fully understand the correlation between COVID-19 and the development of splenic abscesses. PATIENT CONCERNS: A female patient, 71 years of age, was admitted to our hospital because of cough and sputum for 1 week and fever for 2 days. According to the positive results of novel coronavirus nucleic acid and chest computed tomography, novel coronavirus pneumonia was diagnosed. On the 4th day after treatment, abdominal distension and vomiting were observed. Abdominal ultrasound indicated splenomegaly and mixed echo masses in the spleen and abdominal computed tomography indicated 2 new round low-density lesions were found in the spleen. DIAGNOSES: The patient was diagnosed with secondary splenic abscess after COVID-19 infection. INTERVENTIONS: The patient and her family members refused to undergo ultrasound-guided splenic puncture drainage and splenectomy. In terms of treatment, she was given meropenem combined with vancomycin to continue anti-infection treatment. OUTCOMES: The patient's body temperature and infection indicators gradually increased, and the scope of splenic abscess continued to expand. The infection worsened and progressed to septic shock. The patient abandoned rescue drugs and invasive treatment, and died on the 9th day after admission. LESSONS: This case introduces the clinical characteristics of secondary splenic abscess caused by COVID-19 from the aspects of etiology, disease course, clinical manifestations, auxiliary examinations, and treatment methods. The focus is on improving the understanding of clinical doctors about secondary splenic abscesses caused by COVID-19, providing reference for early diagnosis and timely treatment.
Assuntos
COVID-19 , SARS-CoV-2 , Esplenopatias , Humanos , COVID-19/complicações , COVID-19/diagnóstico , Feminino , Esplenopatias/etiologia , Idoso , Abscesso/etiologia , Meropeném/uso terapêutico , Tomografia Computadorizada por Raios XRESUMO
The durable flame-retardant functional coating of polyester/cotton (T/C) blend fabrics is both interesting and challenging. In this study, a novel in-situ polymerization strategy for phosphorus/nitrogen-based flame-retardant on T/C blend samples was developed through the polycondensation of tetramethylolphosphonium sulfate, dicyandiamide, and anionic cyclic phosphate ester. The chemical structure of the polycondensation compounds, as well as the surface morphology, combustion behavior, flame-retardant capacity, washing durability and flame-retardant mechanism of the coated T/C blend fabrics, were investigated. The coated T/C blend fabrics demonstrated excellent self-extinguishing performance, with the damaged length decreasing to as low as 8.0 cm and the LOI reaching 28 %. Moreover, the peak heat release rate of the coated T/C blend fabrics decreased by 39.7 %. The superior flame retardancy can be attributed to the enhanced dehydration and carbonization by phosphate groups in the condensed phase, as well as the quenching effect and diluting effect in the gas phase. Additionally, the coated T/C blend fabrics exhibited remarkable washing durability and still achieved self-extinguishing after 65 washing cycles, and the in-situ deposition of insoluble three-dimensional polycondensation compounds onto the T/C blend fabrics was beneficial. The flame-retardant coating had a minor impact on the whiteness, tensile strength and breathability of the T/C blend fabrics.
RESUMO
BACKGROUND: Impaired hospitalizations for heart failure (HHF) and mortality are associated with tricuspid regurgitation (TR). OBJECTIVES: The objective of this study was to investigate the benefit of transcatheter tricuspid valve replacement (TTVR) over guideline-directed medical therapy (GDMT) in patients with symptomatic severe TR. METHODS: Between May 2020 and April 2023, 88 patients with symptomatic severe TR were treated in our center. Of these, 57 patients received GDMT alone, and 31 patients underwent combined TTVR and GDMT. We collected and analyzed baseline data, and follow-up information for both groups. The primary endpoints were all-cause mortality and the combined endpoint (including all-cause mortality and HHF). RESULTS: At a median follow-up of 20 (IQR 10-29) months, significant improvements were shown in TR severity, right ventricular function, and dimensions in TTVR group (all P < 0.001). It also resulted in superior survival rates (75.8% vs. 48.4%, P = 0.019), improved freedom from combined endpoint (61.5% vs. 45.9%, P = 0.007) and fewer major adverse events. After stratification by TRI-SCORE, the subgroup with < 6 points in the TTVR group exhibited a significant difference in the combined endpoint compared to the other subgroups (all P < 0.05), while no significant differences were observed in the GDMT subgroups (P = 0.680). CONCLUSIONS: The utilization of LuX-Valve in TTVR effectively improves TR and is associated with lower rates of major adverse events, HHF and all-cause mortality. The TRI-SCORE may help identify higher-benefit patients with TR from TTVR. Clinical trial registration ClinicalTrials.gov Protocol Registration System (NCT02917980).
Assuntos
Implante de Prótese de Valva Cardíaca , Insuficiência da Valva Tricúspide , Humanos , Insuficiência da Valva Tricúspide/cirurgia , Masculino , Feminino , Estudos Retrospectivos , Idoso , Implante de Prótese de Valva Cardíaca/métodos , Valva Tricúspide/cirurgia , Pessoa de Meia-Idade , Resultado do Tratamento , Índice de Gravidade de Doença , Cateterismo Cardíaco/métodosRESUMO
The deregulation of cell surface heparan sulfate proteoglycans (HSPGs) is a main issue of cancer cells for increasing their malignancy. In these terms, the sulfation pattern of HS, created by an orchestrated activity of enzymes balancing a site-specific sulfation, is of key importance. These enzymes are often deregulated by epigenetic processes in cancer, e.g., being silenced by DNA hypermethylation. Here, we address this issue in human breast cancer cell lines aiming to target epigenetic processes to reactivate HS sulfation, shifting HS into an antithrombotic phenotype for which 3-O-sulfation is particularly important. Treatment of MCF-7 and MDA-MB-231 cells with nontoxic concentrations of 5-azacytidine (azacytidine) and 5-fluoro-2'-deoxycytidine (FdCyd) as DNMT inhibitors or vorinostat for targeting HDAC increased HS3-O-sulfation remarkably, as confirmed by fluorescence microscopy, by upregulating HS3-O-sulfotransferases, detected by quantitative real-time polymerase chain reaction and Western blot. Flow cytometry and microscopic approaches confirm that upon inhibitor treatment, increased HS3-O-sulfation improves cell binding to antithrombin, leading to an antithrombotic activity. Nevertheless, only azacytidine- and vorinostat-treated cells display anticoagulative properties, represented by attenuated thrombin formation, a lower activation of human platelet aggregation, or ATP release. In contrast, FdCyd additionally upregulated tissue factor expression in both cell lines, overshadowing the anticoagulant effects of HS, leading to an overall prothrombotic phenotype. Our data provide evidence for the first time that targeting epigenetic processes in HS sulfation is a valuable means to foster anticoagulative cell properties for decreasing malignancy and metastatic potency. These data warrant further investigations to fine-tune epigenetic targeting and to search for potential biomarkers attributed to these activities.
RESUMO
Smart materials demonstrate fascinating responses to environmental physical/chemical stimuli, including thermal, photonic, electronic, humidity, or magnetic stimuli, which have attracted intensive interest in material chemistry. However, their limited/harsh stimuli-responsive behavior or sophisticated postprocessing leads to enormous challenges for practical applications. Herein, we rationally designed and synthesized thermochromic Ni(II) organometallic [(C2H5)2NH2]2NiCl4-xBrx via a facile mechanochemical strategy, which demonstrated a reversible switch from yellow to blue color with a tunable phase-transition temperature from 75.6 to 61.7 °C. The simple electrospinning technology was applied to fabricate thermochromic Ni(II) organometallic-based nanofiber membranes for temperature monitoring. Furthermore, the organic charge-transfer cocrystal with a wide spectral absorption of 300-1950 nm and a high-efficiency photothermal conversion was combined with thermochromic Ni(II) organometallics for the desired dual-stimuli photo/thermochromism. This work supplies a new strategy for realizing multiple stimuli-responsive applications, such as thermal/light sensor displays and information storage.
RESUMO
Secreted chemokines form concentration gradients in target tissues to control migratory directions and patterns of immune cells in response to inflammatory stimulation; however, how the gradients are formed is much debated. Heparan sulfate (HS) binds to chemokines and modulates their activities. In this study, we investigated the roles of HS in the gradient formation and chemoattractant activity of CCL5 that is known to bind to HS. CCL5 and heparin underwent liquid-liquid phase separation and formed gradient, which was confirmed using CCL5 immobilized on heparin-beads. The biological implication of HS in CCL5 gradient formation was established in CHO-K1 (wild-type) and CHO-677 (lacking HS) cells by Transwell assay. The effect of HS on CCL5 chemoattractant activity was further proved by Transwell assay of human peripheral blood cells. Finally, peritoneal injection of the chemokines into mice showed reduced recruitment of inflammatory cells either by mutant CCL5 (lacking heparin-binding sequence) or by addition of heparin to wild-type CCL5. Our experimental data propose that co-phase separation of CCL5 with HS establishes a specific chemokine concentration gradient to trigger directional cell migration. The results warrant further investigation on other heparin-binding chemokines and allows for a more elaborate insight into disease process and new treatment strategies.
Assuntos
Quimiocina CCL5 , Quimiotaxia , Cricetulus , Heparitina Sulfato , Quimiocina CCL5/metabolismo , Quimiocina CCL5/genética , Animais , Heparitina Sulfato/metabolismo , Humanos , Células CHO , Camundongos , Heparina/metabolismo , Heparina/farmacologia , Separação de FasesRESUMO
Efficient conversion of biomass wastes into valuable chemicals has been regarded as a sustainable approach for green and circular economy. Herein, a highly efficient catalytic conversion of glycerol (Gly) into glycerol carbonate (GlyC) by carbonylation with the commercially available urea is presented using low-cost transition metal single atoms supported on zinc oxide quantum dots (M1-ZnO QDs) as a catalyst without using any solvent. A facile one-step wet chemical synthesis allows various types of metal single atoms to simultaneously dope and introduce Lewis-acid defects in the ZnO QD structure. It is found that doping with a trace amount of isolated metal atoms greatly boosts the catalytic activity with Gly conversion of 90.7%, GlyC selectivity of 100.0%, and GlyC yield of 90.6%. Congruential results from both Density Functional Theory (DFT) and in situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (in situ DRIFTS) studies reveal that the superior catalytic performance can be attributed to the enriched Lewis acid sites that endow optimal adsorption, formation of the intermediate for coupling between urea and Gly, and desorption of GlyC. Moreover, the tiny size of ZnO QDs efficiently promotes the accessibility of these active sites to the reactants.
RESUMO
Homologous recombination deficiency (HRD) is prevalent in cancer, sensitizing tumor cells to poly (ADP-ribose) polymerase (PARP) inhibition. However, the impact of HRD and related therapies on the tumor microenvironment (TME) remains elusive. Our study generates single-cell gene expression and T cell receptor profiles, along with validatory multimodal datasets from >100 high-grade serous ovarian cancer (HGSOC) samples, primarily from a phase II clinical trial (NCT04507841). Neoadjuvant monotherapy with the PARP inhibitor (PARPi) niraparib achieves impressive 62.5% and 73.6% response rates per RECIST v.1.1 and GCIG CA125, respectively. We identify effector regulatory T cells (eTregs) as key responders to HRD and neoadjuvant therapies, co-occurring with other tumor-reactive T cells, particularly terminally exhausted CD8+ T cells (Tex). TME-wide interferon signaling correlates with cancer cells upregulating MHC class II and co-inhibitory ligands, potentially driving Treg and Tex fates. Depleting eTregs in HRD mouse models, with or without PARP inhibition, significantly suppresses tumor growth without observable toxicities, underscoring the potential of eTreg-focused therapeutics for HGSOC and other HRD-related tumors.
RESUMO
BACKGROUND: Paravalvular leakage (PVL) is a common complication after artificial valve replacement. Transcatheter paravalvular leak closure (PVT), an efficient, safe, and minimally invasive treatment for PVL patients. AIMS: The purpose of this study was to present our experience with transcatheter closure of mitral paravalvular leakage (PVL) after surgical valve replacement in our center. METHODS: A cohort of 81 consecutive patients with mitral PVLs was treated with transcatheter closure between September 2014 and December 2022. We reviewed the demographics, clinical features, therapeutic modalities and follow-up results. The patients' charts were used for retrospective analysis. RESULTS: Eighty-one patients from one center were enrolled in this study. The median age of the patients was 63 ± 11 years. The median LVEF was 51% ± 7%, and the median regurgitation volume was 11.5 ± 10.1 mL. Sealing with occlusion was successful in 70 patients, and the technical success rate was 86.5%. The median regurgitation volume was reduced to 1.95 ± 2.6 mL. The major adverse event was hemolysis, which affected 19 patients, 17 of whom required blood transfusion. Three patients required secondary open surgery due to bleeding. Three patients died during the hospital stay, and all of their deaths were caused by hemolysis-related complications. The median hospital stay was 10.3 ± 6.3 days. During the follow-up period, 2 patients died, and none of their deaths were caused by surgery. The New York Heart Association classification increased in all patients during the 6-month follow-up. CONCLUSION: Transcatheter mitral PVL closure requires complex catheter techniques. However, this technique is minimally invasive and has a shorter hospital stay. Interventional mitral PVL closure is a safe and efficacious technique for high-risk surgical patients with symptomatic paravalvular regurgitation.
RESUMO
O'Donnell-Luria-Rodan (ODLURO) syndrome is an autosomal dominant genetic disorder caused by mutations in the KMT2E (lysine methyltransferase 2E) gene. The Third Xiangya Hospital of Central South University admitted a 12-year and 9-month-old male patient who presented with growth retardation, intellectual disability, and distinctive facial features. Peripheral blood was collected from the patient, and DNA was extracted for genetic testing. Chromosome karyotyping showed 46XY. Whole-exome sequencing and low-coverage massively parallel copy number variation sequencing (CNV-seq) revealed a 506 kb heterozygous deletion in the 7q22.3 region, which includes 6 genes, including KMT2E. The patient was diagnosed with ODLURO syndrome. Both the patient's parents and younger brother had normal clinical phenotypes and genetic test results, indicating that this deletion was a de novo mutation. The clinical and genetic characteristics of this case can help increase clinicians' awareness of ODLURO syndrome.
Assuntos
Deficiência Intelectual , Humanos , Masculino , Deficiência Intelectual/genética , Criança , Histona-Lisina N-Metiltransferase/genética , Mutação , Transtornos do Crescimento/genética , Anormalidades Múltiplas/genética , Cromossomos Humanos Par 7/genética , Cariotipagem , Fenótipo , Variações do Número de Cópias de DNA , Sequenciamento do Exoma , Heterozigoto , Contratura , Microcefalia , FáciesRESUMO
Egg production traits are crucial in the poultry industry, including age at first egg (AFE), egg number (EN) at different stages, and laying rate (LR). Ducks exhibit higher egg production capacity than other poultry species, but the genetic mechanisms are still poorly understood. In this study, we collected egg-laying data of 618 Peking ducks from 22 to 66 weeks of age and genotyped them by whole-genome resequencing. Genetic parameters were calculated based on SNPs, and a genome-wide association study (GWAS) was performed for these traits. The SNP-based heritability of egg production traits ranged from 0.09 to 0.54. The GWAS identified nine significant SNP loci associated with AFE and egg number from 22 to 66 weeks. These loci showed that the corresponding alleles were positively correlated with a decrease in the traits. Moreover, three potential candidate genes (ENSAPLG00020011445, ENSAPLG00020012564, TMEM260) were identified. Functional enrichment analyses suggest that specific immune responses may have a critical impact on egg production capacity by influencing ovarian function and oocyte maturation processes. In conclusion, this study deepens the understanding of egg-laying genetics in Peking duck and provides a sound theoretical basis for future genetic improvement and genomic selection strategies in poultry.
RESUMO
The 2,7-fluorenone-linked bis(6-imidazo[1,5-a]pyridinium) salt H2-1(PF6)2 reacts with Ag2O in CH3CN to yield the [2]catenane [Ag4(1)4](PF6)4. The [2]catenane rearranges in DMF to yield two metallamacrocycles [Ag2(1)2](PF6)2. 2,7-Fluorenone-bridged bis-(imidazolium) salts H2-L(PF6)2 (L=2 a, 2 b) react with Ag2O in CH3CN to yield metallamacrocycles [Ag2(L)2](PF6)2 with interplanar distances between the fluorenone rings too small for [2]catenane formation. Intra- and intermolecular πâ â â π interactions between the fluorenone groups were observed by X-ray crystallography. The strongly kinked 2,7-fluorenone bridged bis(5-imidazo[1,5-a]pyridinium) salt H2-4(PF6)2 reacts with Ag2O to yield [Ag2(4)(CN)](PF6), while the tetranuclear assembly [Ag4(4)2(CO3)](PF6)2 was obtained in the presence of K2CO3.
RESUMO
Endometrial cancer is the most common gynecological cancer in the developed world. However, the accuracy of current diagnostic methods is still unsatisfactory and time-consuming. Here, we presented an alternate approach to monitoring the progression of endometrial cancer via multiphoton microscopy imaging and analysis of collagen, which is often overlooked in current endometrial cancer diagnosis protocols but can offer a crucial signature in cancer biology. Multiphoton microscopy (MPM) based on the second-harmonic generation and two-photon excited fluorescence was introduced to visualize the microenvironment of endometrium in normal, hyperplasia without atypia, atypical hyperplasia, and endometrial cancer specimens. Furthermore, automatic image analysis based on the MPM image processing algorithm was used to quantify the differences in the collagen morphological features among them. MPM enables the visualization of the morphological details and alterations of the glands in the development process of endometrial cancer, including irregular changes in the structure of the gland, increased ratio of the gland to the interstitium, and atypical changes in the glandular epithelial cells. Moreover, the destructed basement membrane caused by gland proliferation and fusion is clearly shown in SHG images, which is a key feature for identifying endometrial cancer progression. Quantitative analysis reveals that the formation of endometrial cancer is accompanied by an increase in collagen fiber length and width, a progressive linearization and loosening of interstitial collagen, and a more random arrangement of interstitial collagen. Observation and quantitative analysis of interstitial collagen provide invaluable information in monitoring the progression of endometrial cancer. Label-free multiphoton imaging reported here has the potential to become an in situ histological tool for effective and accurate early diagnosis and detection of malignant lesions in endometrial cancer.
RESUMO
The Drosophila Imd pathways are well-known mechanisms involved in innate immunity responsible for Gram-negative (G-) bacterial infection. The intensity and durability of immunity need to be finely regulated to keep sufficient immune activation meanwhile avoid excessive immune response. In this study, we firstly demonstrated that miR-190 can downregulate the expression levels of antimicrobial peptides (AMPs) in the Imd immune pathway after Escherichia coli infection using the miR-190 overexpression flies and the miR-190KO/+ flies. Secondly, miR-190 overexpression significantly reduces while miR-190 KO increases Drosophila survival rates upon lethal Enterobacter cloacae infection. Thirdly, we further demonstrated that miR-190 negatively regulates innate immune responses by directly targeting both RA/RB and RC isoforms of Tab2. In addition, the dynamic expression pattern of AMPs (Dpt, AttA, CecA1), miR-190 and Tab2 in the wild-type flies reveals that miR-190 play an important role in Drosophila immune homeostasis restoration at the late stage of E. coli infection. Collectively, our study reveals that miR-190 can downregulate the expression of AMPs by targeting Tab2 and promote immune homeostasis restoration in Drosophila Imd pathway. Our study provides new insights into the regulatory mechanism of animal innate immune homeostasis.
RESUMO
Natural heparin, a glycosaminoglycan consisting of repeating hexuronic acid and glucosamine linked by 1 â 4 glycosidic bonds, is the most widely used anticoagulant. To subvert the dependence on animal sourced heparin, alternative methods to produce heparin saccharides, i.e., either heterogenous sugar chains similar to natural heparin, or structurally defined oligosaccharides, are becoming hot subjects. Although the success by chemical synthesis of the pentasaccharide, fondaparinux, encourages to proceed through a chemical approach generating homogenous product, synthesizing larger oligos is still cumbersome and beyond reach so far. Alternatively, the chemoenzymatic pathway exhibited exquisite stereoselectivity of glycosylation and regioselectivity of modification, with the advantage to skip the tedious protection steps unavoidable in chemical synthesis. However, to a scale of drug production needed today is still not in sight. In comparison, a procedure of de novo biosynthesis in an organism could be an ultimate goal. The main purpose of this review is to summarize the current available/developing strategies and techniques, which is expected to provide a comprehensive picture for production of heparin saccharides to replenish or eventually to replace the animal derived products. In chemical and chemoenzymatic approaches, the methodologies are discussed according to the synthesis procedures: building block preparation, chain elongation, and backbone modification.
Assuntos
Anticoagulantes , Heparina , Animais , Anticoagulantes/síntese química , Anticoagulantes/química , Glicosilação , Heparina/química , Heparina/síntese química , Oligossacarídeos/síntese química , Oligossacarídeos/químicaRESUMO
T cell activation is an essential step in chimeric Ag receptor (CAR) T (CAR T) cell manufacturing and is accomplished by the addition of activator reagents that trigger the TCR and provide costimulation. We explore several T cell activation reagents and examine their effects on key attributes of CAR T cell cultures, such as activation/exhaustion markers, cell expansion, gene expression, and transduction efficiency. Four distinct activators were examined, all using anti-CD3 and anti-CD28, but incorporating different mechanisms of delivery: Dynabeads (magnetic microspheres), TransAct (polymeric nanomatrix), Cloudz (alginate hydrogel), and Microbubbles (lipid membrane containing perfluorocarbon gas). Clinical-grade lentiviral vector was used to transduce cells with a bivalent CD19/CD22 CAR, and cell counts and flow cytometry were used to monitor the cells throughout the culture. We observed differences in CD4/CD8 ratio when stimulating with the Cloudz activator, where there was a significant skewing toward CD8 T cells. The naive T cell subset expressing CD62L+CCR7+CD45RA+ was the highest in all donors when stimulating with Dynabeads, whereas effector/effector memory cells were highest when using the Cloudz. Functional assays demonstrated differences in killing of target cells and proinflammatory cytokine secretion, with the highest killing from the Cloudz-stimulated cells among all donors. This study demonstrates that the means by which these stimulatory Abs are presented to T cells contribute to the activation, resulting in differing effects on CAR T cell function. These studies highlight important differences in the final product that should be considered when manufacturing CAR T cells for patients in the clinic.
Assuntos
Ativação Linfocitária , Receptores de Antígenos Quiméricos , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Humanos , Ativação Linfocitária/imunologia , Imunoterapia Adotiva/métodos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T/imunologia , Fenótipo , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Antígenos CD19/imunologia , Antígenos CD19/metabolismoRESUMO
Biomacromolecular condensates formed via phase separation establish compartments for the enrichment of specific compositions, which is also used as a biological tool to enhance molecule condensation, thereby increasing the efficiency of biological processes. Proteolysis-targeting chimeras (PROTACs) have been developed as powerful tools for targeted protein degradation in cells, offering a promising approach for therapies for different diseases. Herein, we introduce an intrinsically disordered region in the PROTAC (denoted PSETAC), which led to the formation of droplets of target proteins in the cells and increased degradation efficiency compared with PROTAC without phase separation. Further, using a nucleus targeting intrinsically disordered domain, the PSETAC was able to target and degrade nuclear-located proteins. Finally, we demonstrated intracellular delivery of PSETAC using lipid nanoparticle-encapsulated mRNA (mRNA-LNP) for the degradation of the endogenous target protein. This study established the PSETAC mRNA-LNP method as a potentially translatable, safe therapeutic strategy for the development of clinical applications based on PROTAC.
Assuntos
Proteólise , RNA Mensageiro , Proteólise/efeitos dos fármacos , Humanos , RNA Mensageiro/genética , Nanopartículas/química , Lipídeos/química , Células HeLa , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Separação de Fases , LipossomosRESUMO
To overcome the trade-off challenge encountered in the engineering of alginate lyase AlyG2 from Seonamhaeicola algicola Gy8T and to expand its potential industrial applications, we devised a two-step strategy encompassing activity enhancement followed by thermal stability engineering. To enhance the specific activity of efficient AlyG2, we strategically substituted residues with bulky steric hindrance proximal to the active pocket with glycine or alanine. This led to the generation of three promising positive mutants, with particular emphasis on the T91S mutant, exhibiting a 1.91-fold specific activity compared to the wild type. To mitigate the poor thermal stability of T91S, mutants with negative ΔΔG values in the thermal flexibility region were screened out. Notably, the S72Ya mutant not only displayed 17.96 % further increase in specific activity but also exhibited improved stability compared to T91S, manifesting as a remarkable 30.97 % increase in relative activity following a 1-hour incubation at 42 °C. Furthermore, enhanced kinetic stability was observed. To gain deeper insights into the mechanism underlying the enhanced thermostability of the S72Ya mutant, we conducted molecular dynamics simulations, principal component analysis (PCA), dynamic cross-correlation map (DCCM), and free energy landscape (FEL) analysis. The results unveiled a reduction in the flexibility of the surface loop, a stronger correlation dynamic and a narrower motion subspace in S72Ya system, along with the formation of more stable hydrogen bonds. Collectively, our findings suggest amino acids substitutions resulting in smaller side chains proximate to the active site can positively impact enzyme activity, while reducing the flexibility of surface loops emerges as a pivotal factor in conferring thermal stability. These insights offer valuable guidance and a framework for the engineering of other enzyme types.
Assuntos
Estabilidade Enzimática , Simulação de Dinâmica Molecular , Polissacarídeo-Liases , Polissacarídeo-Liases/química , Polissacarídeo-Liases/genética , Polissacarídeo-Liases/metabolismo , Cinética , Temperatura , Engenharia de Proteínas/métodos , Mutação , Substituição de Aminoácidos , Mutagênese Sítio-DirigidaRESUMO
Background: The primary aim of this study is to investigate the correlation between serum levels of fibrinogen-to-prealbumin ratio (FPR) and C-reactive protein-to-prealbumin ratio (CPR) and prognostic outcomes among patients with severe fever with thrombocytopenia syndrome (SFTS). SFTS, characterized by elevated mortality rates, represents a substantial public health challenge as an emerging infectious disease. Methods: The study included 159 patients with SFTS. Clinical and laboratory data were compared between the survival and death groups. Univariate and multivariate logistic regression analysis were utilized to identify independent risk factors for mortality. The predictive efficacy of FPR and CPR was evaluated using receiver operating characteristic (ROC) curve. Survival analysis was conducted using the Kaplan-Meier curve and the log-rank test was employed for comparison. Results: The death group exhibited significantly elevated levels of FPR and CPR compared to the survival group (P < 0.05). Multivariate logistic regression analysis confirmed that both FPR and CPR independently correlated with a poorer prognosis among patients with SFTS. The ROC curve analysis indicated that FPR and CPR had superior predictive capabilities compared to C-reactive protein and fibrinogen. Kaplan-Meier survival analysis demonstrated that patients with SFTS who have FPR > 0.045 (log-rank test; χ2 = 17.370, P < 0.001) or CPR > 0.05 (log-rank test; χ2 = 19.442, P < 0.001) experienced significantly lower survival rates within a 30-day follow-up period. Conclusion: Elevated levels of FPR and CPR serve as distinct risk factors for mortality among patients with SFTS, indicating their potential to predict an unfavorable prognosis in these patients.
Assuntos
Proteína C-Reativa , Fibrinogênio , Pré-Albumina , Curva ROC , Febre Grave com Síndrome de Trombocitopenia , Humanos , Proteína C-Reativa/análise , Proteína C-Reativa/metabolismo , Masculino , Feminino , Fibrinogênio/análise , Fibrinogênio/metabolismo , Prognóstico , Pessoa de Meia-Idade , Idoso , Febre Grave com Síndrome de Trombocitopenia/sangue , Febre Grave com Síndrome de Trombocitopenia/mortalidade , Pré-Albumina/análise , Pré-Albumina/metabolismo , Biomarcadores/sangue , Fatores de Risco , Adulto , Phlebovirus , Estimativa de Kaplan-Meier , Estudos RetrospectivosRESUMO
BACKGROUND: Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder affecting women of reproductive ages. Our previous study has implicated a possible link between RNA editing and PCOS, yet the actual role of RNA editing, its association with clinical features, and the underlying mechanisms remain unclear. METHODS: Ten RNA-Seq datasets containing 269 samples of multiple tissue types, including granulosa cells, T helper cells, placenta, oocyte, endometrial stromal cells, endometrium, and adipose tissues, were retrieved from public databases. Peripheral blood samples were collected from twelve PCOS and ten controls and subjected to RNA-Seq. Transcriptome-wide RNA-Seq data analysis was conducted to identify differential RNA editing (DRE) between PCOS and controls. The functional significance of DRE was evaluated by luciferase reporter assays and overexpression in human HEK293T cells. Dehydroepiandrosterone and lipopolysaccharide were used to stimulate human KGN granulosa cells to evaluate gene expression. RESULTS: RNA editing dysregulations across multiple tissues were found to be associated with PCOS in public datasets. Peripheral blood transcriptome analysis revealed 798 DRE events associated with PCOS. Through weighted gene co-expression network analysis, our results revealed a set of hub DRE events in PCOS blood. A DRE event in the eukaryotic translation initiation factor 2-alpha kinase 2 (EIF2AK2:chr2:37,100,559) was associated with PCOS clinical features such as luteinizing hormone (LH) and the ratio of LH over follicle-stimulating hormone. Luciferase assays, overexpression, and knockout of RNA editing enzyme adenosine deaminase RNA specific (ADAR) showed that the ADAR-mediated editing cis-regulated EIF2AK2 expression. EIAF2AK2 showed a higher expression after dehydroepiandrosterone and lipopolysaccharide stimulation, triggering changes in the downstrean MAPK pathway. CONCLUSIONS: Our study presented the first evidence of cross-tissue RNA editing dysregulation in PCOS and its clinical associations. The dysregulation of RNA editing mediated by ADAR and the disrupted target EIF2AK2 may contribute to PCOS development via the MPAK pathway, underlining such epigenetic mechanisms in the disease.