Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 93
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
Ying Yong Sheng Tai Xue Bao ; 35(1): 195-202, 2024 Jan.
Artículo en Chino | MEDLINE | ID: mdl-38511456

RESUMEN

In order to understand the response and adaptation mechanisms of photosynthetic characteristics and growth for Cunninghamia lanceolata saplings in the subtropical region to global warming, we conducted the root-box warming experiment (ambient, ambient+4 ℃) at the Sanming Forest Ecosystem National Observation and Research Station in Fujian Province to investigate the effects of soil warming on the photosynthetic characteristics and growth of C. lanceolata saplings in different seasons. The results showed that the net photosynthetic rate (Pn) and stomatal conductance (gs) of C. lanceolata significantly decreased in summer compared with in spring and autumn. Soil warming had no effect on the Pn and gs of C. lanceolata. However, the interaction between warming and season significantly impacted the leaf water use efficiency (WUE). The tree height and ground diameter growth of C. lanceolata significantly increased in spring compared with in summer and autumn. Warming significantly reduced ground diameter growth, and it diminished the net diameter growth by 48.1% in autumn. However, warming had no impact on the tree height growth of C. lanceolata in each season. The specific leaf area, soluble sugar, and non-structural carbohydrates contents of C. lanceolata significantly improved in summer and autumn compared with in spring. Warming had rarely influence on leaf functional traits in each season. In conclusion, the response of photosynthesis for C. lanceolata to soil warming was insignificant. The photosynthesis of C. lanceolata exhibited significant seasonal dynamics, primarily controlled by gs. C. lanceolata adapted to soil warming by adjusting WUE, and it adjusted to high temperatures and drought stress in summer by increasing soluble sugar content and specific leaf area. The effect of warming on ground diameter growth of C. lanceolata was primarily driven by soil moisture. The seasonal difference in the growth of C. lanceolata was influenced by the photosynthesis of C. lanceolata and the trade-off between the utilization and storage of photosynthetic products.


Asunto(s)
Cunninghamia , Ecosistema , Carbohidratos , Fotosíntesis , Estaciones del Año , Suelo/química , Azúcares , Árboles/fisiología
2.
Nat Commun ; 15(1): 996, 2024 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-38307858

RESUMEN

Postzygotic reproductive isolation, which results in the irreversible divergence of species, is commonly accompanied by hybrid sterility, necrosis/weakness, or lethality in the F1 or other offspring generations. Here we show that the loss of function of HWS1 and HWS2, a couple of duplicated paralogs, together confer complete interspecific incompatibility between Asian and African rice. Both of these non-Mendelian determinants encode the putative Esa1-associated factor 6 (EAF6) protein, which functions as a characteristic subunit of the histone H4 acetyltransferase complex regulating transcriptional activation via genome-wide histone modification. The proliferating tapetum and inappropriate polar nuclei arrangement cause defective pollen and seeds in F2 hybrid offspring due to the recombinant HWS1/2-mediated misregulation of vitamin (biotin and thiamine) metabolism and lipid synthesis. Evolutionary analysis of HWS1/2 suggests that this gene pair has undergone incomplete lineage sorting (ILS) and multiple gene duplication events during speciation. Our findings have not only uncovered a pair of speciation genes that control hybrid breakdown but also illustrate a passive mechanism that could be scaled up and used in the guidance and optimization of hybrid breeding applications for distant hybridization.


Asunto(s)
Oryza , Oryza/genética , Fitomejoramiento , Reproducción , Evolución Biológica , Hibridación Genética
3.
Zhongguo Zhong Yao Za Zhi ; 49(1): 185-196, 2024 Jan.
Artículo en Chino | MEDLINE | ID: mdl-38403351

RESUMEN

This study investigated the effect of trametenolic acid(TA) on the migration and invasion of human hepatocellular carcinoma HepG2.2.15 cells by using Ras homolog gene family member C(RhoC) as the target and probed into the mechanism, aiming to provide a basis for the utilization of TA. The methyl thiazolyl tetrazolium(MTT) assay was employed to examine the proliferation of HepG2.2.15 cells exposed to TA, and scratch and Transwell assays to examine the cell migration and invasion. The pull down assay was employed to determine the impact of TA on RhoC GTPase activity. Western blot was employed to measure the effect of TA on the transport of RhoC from cytoplasm to cell membrane and the expression of RhoC/Rho-associated kinase 1(ROCK1)/myosin light chain(MLC)/matrix metalloprotease 2(MMP2)/MMP9 pathway-related proteins. RhoC was over-expressed by transient transfection of pcDNA3.1-RhoC. The changes of F-actin in the cytoskeleton were detected by Laser confocal microscopy. In addition, the changes of cell migration and invasion, expression of proteins in the RhoC/ROCK1/MLC/MMP2/MMP9 pathway, and RhoC GTPase activity were detected. The subcutaneously transplanted tumor model of BALB/c nude mice and the low-, medium-, and high-dose(40, 80, and 120 mg·kg~(-1), respectively) TA groups were established and sorafenib(20 mg·kg~(-1)) was used as the positive control. The tumor volume and weight in each group were measured, and the expression of related proteins in the tumor tissue was determined by Western blot. The results showed that TA inhibited the proliferation of HepG2.2.15 cells in a concentration-dependent manner, with the IC_(50) of 66.65 and 23.09 µmol·L~(-1) at the time points of 24 and 48 h, respectively. The drug administration groups had small tumors with low mass. The tumor inhibition rates of sorafenib and low-, medium-and high-dose TA were 62.23%, 26.48%, 55.45%, and 62.36%, respectively. TA reduced migrating and invading cells and inhibited RhoC protein expression and RhoC GTPase activity in a concentration-dependent manner, dramatically reducing RhoC and membrane-bound RhoC GTPase. The expression of ROCK1, MLC, p-MLC, MMP2, and MMP9 downstream of RhoC can be significantly inhibited by TA, as confirmed in both in vitro and in vivo experiments. After HepG2.2.15 cells were transfected with pcDNA3.1-RhoC to overexpress RhoC, TA down-regulated the protein levels of RhoC, ROCK1, MLC, p-MLC, MMP2, and MMP9 and decreased the activity of RhoC GTPase, with the inhibition level comparable to that before overexpression. In summary, TA can inhibit the migration and invasion of HepG2.2.15 cells. It can inhibit the RhoC/ROCK1/MLC/MMP2/MMP9 signaling pathway by suppressing RhoC GTPase activity and down-regulating RhoC expression. This study provides a new idea for the development of autophagy modulators targeting HSP90α to block the proliferation and inhibit the invasion and migration of hepatocellular carcinoma cells via multiple targets of active components in traditional Chinese medicines.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animales , Ratones , Humanos , Proteína rhoC de Unión a GTP/metabolismo , Carcinoma Hepatocelular/tratamiento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Metaloproteinasa 9 de la Matriz/metabolismo , Proteínas de Unión al GTP rho/genética , Proteínas de Unión al GTP rho/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Quinasas Asociadas a rho/genética , Quinasas Asociadas a rho/metabolismo , Sorafenib , Ratones Desnudos , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Línea Celular Tumoral , Invasividad Neoplásica/genética , Invasividad Neoplásica/patología , Movimiento Celular , Proliferación Celular
4.
Arch Microbiol ; 206(3): 125, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38411841

RESUMEN

Non-specific endonucleases can be used for the digestion of nucleic acids because they hydrolyze DNA/RNA into 3-5 base pairs (bp) length oligonucleotide fragments without strict selectivity. In this work, a novel non-specific endonuclease from Pseudomonas fluorescens (PfNuc) with high activities for both DNA and RNA was successfully cloned and expressed in Escherichia coli. The production of PfNuc in flask scale could be achieved to 1.73 × 106 U/L and 4.82 × 106 U/L for DNA and RNA by investigation of the culture and induction conditions. The characterization of PfNuc indicated that it was Mg2+-dependent and the catalytic activity was enhanced by 3.74 folds for DNA and 1.06 folds for RNA in the presence of 5 mM Mg2+. The specific activity of PfNuc for DNA was 1.44 × 105 U/mg at pH 8.0 and 40 °C, and 3.93 × 105 U/mg for RNA at pH 8.5 and 45 °C. The Km of the enzyme for both DNA and RNA was close to 43 µM. The Vmax was 6.40 × 105 U/mg and 1.11 × 106 U/mg for DNA and RNA, respectively. There was no observed activity loss when PfNuc was stored at 4 °C and - 20 °C after 28 days or 10 repeated freeze-thaw cycles at - 80 °C. Molecular docking revealed that PfNuc formed 17 and 19 hydrogen bonds with single-stranded RNA and double-stranded DNA, respectively. These results could explain the high activity and stability of PfNuc, suggesting its great potential applications in the industry and clinic.


Asunto(s)
Pseudomonas fluorescens , Pseudomonas fluorescens/genética , Simulación del Acoplamiento Molecular , ARN , Endonucleasas/genética , Escherichia coli/genética , ADN , Clonación Molecular
5.
J Agric Food Chem ; 72(6): 3045-3054, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38307881

RESUMEN

A novel heparinase III from Pedobacter schmidteae (PsHep-III) with high activity and good stability was successfully cloned, expressed, and characterized. PsHep-III displayed the highest specific activity ever reported of 192.8 U mg-1 using heparin as the substrate. It was stable at 25 °C with a half-life of 323 h in an aqueous solution. PsHep-III was employed for the depolymerization of heparin, and the enzymatic hydrolyzed products were analyzed with gel permeation chromatography and high-performance liquid chromatography. PsHep-III can break glycosidic bonds in heparin like →4]GlcNAc/GlcNAc6S/GlcNS/GlcNS6S/GlcN/GlcN6S(1 → 4)ΔUA/ΔUA2S[1 → and efficiently digest heparin into seven disaccharides including N-acetylated, N-sulfated, and N-unsubstituted modification, with molecular masses of 503, 605, 563, 563, 665, 360, and 563 Da, respectively. These results indicated that PsHep-III with broad substrate specificity could be combined with heparinase I to overcome the low selectivity at the N-acetylated modification binding sites of heparinase I. This work will contribute to the application of PsHep-III for characterizing heparin and producing low-molecular-weight heparin effectively.


Asunto(s)
Heparina , Polisacárido Liasas , Heparina/análisis , Heparina/química , Heparina/metabolismo , Liasa de Heparina/genética , Liasa de Heparina/química , Liasa de Heparina/metabolismo , Polisacárido Liasas/genética , Polisacárido Liasas/metabolismo , Sitios de Unión
6.
Immun Inflamm Dis ; 12(2): e1172, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38358044

RESUMEN

INTRODUCTION: Nuclear receptor subfamily five group A member two (NR5A2) plays a key role in the development of many tumor types, while it is uncertain in cutaneous squamous cell carcinoma (cSCC). The aim of this work was to determine the role of NR5A2 in cSCC proliferation, and to determine whether NR5A2 mediates the effect of cisplatin in cSCC. METHODS: We performed a systematic study of existing data and conducted a preliminary bioinformatics analysis of NR5A2 expression in cSCC using bioinformatics databases. Immunohistochemical staining was performed on cSCC tissues of seven patients to study NR5A2 expression. NR5A2 expression was examined in human keratin-forming cells (HaCaT) and human cSCC cells (A431, Colo-16, SCL-1, SCL-2, and HSC-5). Stable A431 and SCL-2 cell lines consisting of sh-RNA-NR5A2 were constructed to detect changes in cell proliferation, cell cycle, apoptosis, and to determine the key proteins in the Wnt/ß-catenin pathway. We also investigated changes in the effects of cisplatin on cSCC cells by CCK-8, clone formation assay, and Flow apoptosis assay after NR5A2 knockdown. RESULTS: NR5A2 showed enhanced expression in cSCC tissues than in healthy tissues. Downregulation of NR5A2 in cSCC cells led to the formation of a less malignant phenotype. In contrast, the proliferative capacity of the cSCC cells was enhanced posttreatment with RJW100, an NR5A2 agonist. Additionally, NR5A2 knockdown led to a decrease in the expression level of the proteins in the Wnt/ß-catenin pathway, and this inhibition was reversed by LiCl and recombinant antibody, Wnt3a. Moreover, NR5A2 knockdown resulted in diminished proliferative capacity and increased apoptotic cells after the addition of cisplatin. CONCLUSION: NR5A2 plays a crucial role in the progression of cSCC, and the Wnt/ß-catenin signaling pathway may be involved in the regulation of NR5A2-mediated cSCC. Knockdown of NR5A2 enhanced both the proliferation inhibiting and apoptosis promoting effects of cisplatin on cSCC.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias Cutáneas , Humanos , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/genética , beta Catenina/genética , beta Catenina/metabolismo , Cisplatino/farmacología , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/genética , Línea Celular Tumoral , Receptores Citoplasmáticos y Nucleares
7.
Funct Integr Genomics ; 23(4): 329, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37910254

RESUMEN

Improved chondrogenic differentiation of mesenchymal stem cells (MSCs) by genetic regulation is a potential method for regenerating articular cartilage. LncRNA MIR22HG has been proven to accelerate osteogenic differentiation, but the regulation mechanism of chondrogenic differentiation is still unclear. Human adipose-derived stem cells (hADSCs) have been widely utilised for bone tissue engineering applications. The present study aimed to examine the effect of MIR22HG on the chondrogenic differentiation of hADSCs. The results confirmed that MIR22HG was downregulated in the process of chondrogenic differentiation. Subsequently, gain- and loss-of-function of MIR22HG experiments showed that the overexpression of MIR22HG suppressed the deposition of cartilage matrix proteoglycans and decreased the expression of cartilage-related markers (e.g. Sox9, ACAN and Col2A1), whereas the knockdown of MIR22HG had the opposite effect. MIR22HG could bind to CTCF (CCCTC-binding factor), and CTCF could bind to the CRLF1 (cytokine receptor-like factor 1) promoter and upregulate CRLF1 gene expression. Besides, inhibition of CRLF1 can reverse the effect of MIR22HG on cell chondrogenic differentiation of hADSCs. Taken together, our outcomes reveal that MIR22HG suppressed chondrogenic differentiation by interaction with CTCF to stabilise CRLF1.


Asunto(s)
Células Madre Mesenquimatosas , ARN Largo no Codificante , Humanos , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Osteogénesis , Factor de Unión a CCCTC/genética , Factor de Unión a CCCTC/metabolismo , Factor de Unión a CCCTC/farmacología , Diferenciación Celular/genética , Células Madre Mesenquimatosas/metabolismo , Células Cultivadas
8.
Clin Neurol Neurosurg ; 233: 107956, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37729800

RESUMEN

Epilepsy is one of the most common disorders in children, with an incidence rate of approximately 5%. Although an increasing number of genes have been demonstrated to be pathogenic factors in epilepsy, evidence for a potential pathogenic role of ATP6V1A remains limited. Herein, the clinical and genetic data of a 5-year-old boy who experienced seizures at 9 months of age are collected. Genetic variants are screened using whole-exome sequencing (WES), and the effects of the candidate variants are further validated at both the RNA and protein levels. WES reveals a heterozygous variant [NM_001690.4: c .1132 C>T, p.Leu378Phe] of the ATP6V1A gene. This variant is not reported in the public database, but is predicted to be deleterious by multiple software packages, and classified as a variant of unknown significance following the American College of Medical Genetics and Genomics guidelines. Quantitative PCR and western blotting further confirm its down-regulatory role in both the RNA and protein expression of ATP6V1A. This case report confirms the pathogenicity of ATP6V1A in epilepsy with solid experimental evidence, thereby expanding the phenotype spectrum of ATP6V1A variants. More importantly, we show that seizures triggered by ATP6V1A variants could be controlled by Levetiracetam, crucially rescuing the development of the patient.


Asunto(s)
Epilepsia , ATPasas de Translocación de Protón Vacuolares , Preescolar , Humanos , Masculino , Pueblos del Este de Asia , Epilepsia/genética , Epilepsia/patología , Mutación , Linaje , ARN , Convulsiones , ATPasas de Translocación de Protón Vacuolares/genética , Lactante
9.
J Adv Res ; 2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37648022

RESUMEN

INTRODUCTION: Sessile plants engage in trade-offs between growth and defense capacity in response to fluctuating environmental cues. MYB is an important transcription factor that plays many important roles in controlling plant growth and defense. However, the mechanism behind how it keeps a balance between these two physiological processes is still largely unknown. OBJECTIVES: Our work focuses on the dissection of the molecular mechanism by which GhMYB33 regulates plant growth and defense. METHODS: The CRISPR/Cas9 technique was used to generate mutants for deciphering GhMYB33 functions. Yeast two-hybrid, luciferase complementary imaging, and co-immunoprecipitation assays were used to prove that proteins interact with each other. We used the electrophoretic mobility shift assay, yeast one-hybrid, and luciferase activity assays to analyze GhMYB33 acting as a promoter. A ß-glucuronidase fusion reporter and 5' RNA ligase mediated amplification of cDNA ends analysis showed that ghr-miR319c directedly cleaved the GhMYB33 mRNA. RESULTS: Overexpressing miR319c-resistant GhMYB33 (rGhMYB33) promoted plant growth, accompanied by a significant decline in resistance against Verticillium dahliae. Conversely, its knockout mutant, ghmyb33, demonstrated growth restriction and concomitant augmentation of V. dahliae resistance. GhMYB33 was found to couple with the DELLA protein GhGAI1 and bind to the specific cis-elements of GhSPL9 and GhDFR1 promoters, thereby modulating internode elongation and plant resistance in V. dahliae infection. The ghr-miR319c was discovered to target and suppress GhMYB33 expression. The overexpression of ghr-miR319c led to enhanced plant resistance and a simultaneous reduction in plant height. CONCLUSION: Our findings demonstrate that GhMYB33 encodes a hub protein and controls the expression of GhSPL9 and GhDFR1, implicating a pivotal role for the miR319c-MYB33 module to regulate the trade-offs between plant growth and defense.

10.
Healthcare (Basel) ; 11(14)2023 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-37510548

RESUMEN

The temporomandibular joint (TMJ) disc displacement is the most common temporomandibular disorders (TMD) condition. It causes clicking, pain, limited mandibular movements, and even masticatory difficulties in many people. The aim of this study is showcasing hotspots and frontiers in the field and providing a reference for the future research by a bibliometric analysis. Studies published from 1992 to 2022 were retrieved from Web of Science Core Collection on 23 April 2023. A total of 1882 studies (1739 articles and 143 reviews) were included in the bibliometric analysis. From 1992 to 2022, the annual number of publications and citations greatly increased. The United States of America (USA) contributed the most publications about TMJ disc displacement. Shanghai Jiao Tong University was the most productive institution; meanwhile, Yang, C. from this institution was the most prolific author. The University of Washington was the most influential institution, and Brooks, S. was the most influential author. Diagnostic criteria and management of TMJ disc displacement, as well as TMJ disc displacement-associated conditions, might be a hotspot for current global research. We provided an objective and valuable reference for future research on TMJ disc displacement.

11.
J Orthop Surg Res ; 18(1): 430, 2023 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-37312126

RESUMEN

BACKGROUND: Tumor necrosis factor-alpha (TNF-α), one of the pro-inflammatory cytokines mediating the local inflammatory process in joints, inhibits cartilage formation and has a detrimental effect on stem cell-based cartilage regeneration for the treatment of osteoarthritis (OA). However, the mechanisms behind this inhibitory effect are still poorly understood. Mitochondrial morphological changes mediated by mitochondrial fusion and fission are highly plastic, are quite sensitive to environmental stimuli and play a crucial role in maintaining cell structure and function. In our study, chondrogenic differentiated human adipose stem cells (hADSCs) were exposed to TNF-α and the effect of TNF-α on the ability of hADSCs to chondrogenic differentiate and on mitochondrial fusion and fission was observed and analyzed. The aim was to investigate the role and mechanisms of mitochondrial fusion and fission regulation in the chondrogenic differentiation of hADSCs under normal conditions and under exposure to TNF-α. METHODS: We used flow cytometry to identify hADSCs immunophenotypes CD29, CD44, CD34, CD45, and HLA-DR. Alcian blue staining and Sirius red staining were used to observe the formation of proteoglycans and collagen during the chondrogenic differentiation of hADSCs, respectively. The mRNA and protein expression levels of the cartilage formation marker SOX9, type II collagen (COL2A1), and Aggrecan were measured by real-time fluorescent quantitative PCR (RT-qPCR) and western blot, respectively. The fluorescent probes MitoTracker® Red CMXRos and JC-1 were used to visualize mitochondria morphology and detect mitochondrial membrane electricity (MMP). Affymetrix PrimeView™ chips were used for gene expression profiling. RESULTS: The results showed that the chondrogenic differentiation of hADSCs was inhibited in the presence of TNF-α that optic atrophy 1 (OPA1) expression was significantly upregulated and mitochondria were prolonged and interconnected during this process. Gene microarray and RT-qPCR data showed that the presence of TNF-α led to increased expression of TNFα receptor 2 (TNFRSF1B) and RELA during chondrogenic differentiation of hADSCs. CONCLUSIONS: TNF-α inhibits chondrogenic differentiation of human adipose stem cells by activating RELA expression through TNFRSF1B upregulating OPA1 expression thereby increasing mitochondrial fusion.


Asunto(s)
Adipocitos , Factor de Necrosis Tumoral alfa , Humanos , Factor de Necrosis Tumoral alfa/farmacología , Diferenciación Celular/genética , Citocinas , Mitocondrias , GTP Fosfohidrolasas , Receptores Tipo II del Factor de Necrosis Tumoral , Factor de Transcripción ReIA
12.
Carbohydr Polym ; 312: 120793, 2023 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-37059533

RESUMEN

A novel iminodisuccinate modified chitin (ICH) was prepared using crab shells via a one-step facile procedure. The ICH with grafting degree of 1.46 and deacetylation degree of 47.68 % possessed maximum adsorption capacity of 2572.41 mg/g for silver ions (Ag(I)).The ICH also exhibited good selectivity and reusability. The adsorption followed better with the Freundlich isotherm model, while fitted well with both the Pseudo-first-order and Pseudo-second-order kinetics models. The characteristical results showed that the excellent Ag(I) adsorption capability of ICH should be attributed to both looser porous microstructure as well as additional functional groups-grafting molecular. Moreover, the Ag-loaded ICH (ICH-Ag) showed remarkable antibacterial properties against six typical pathogenic bacteria strains (Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Salmonella typhimurium, Staphylococcus aureus, and Listeria monocytogenes), with the corresponding 90 % minimal inhibitory concentrations ranged 0.426-0.685 mg/mL. Further study on the silver release, microcell morphology, and metagenomic analysis suggested that many Ag nanoparticles were formed after the Ag(I) adsorption, and the antibacterial mechanisms of the ICH-Ag involved both cell membranes destruction and intracellular metabolism disturbing. This research presented a coupling solution of crab shell wastes treatment with chitin-based bioadsorbents preparation, metal removal and recovery, as well as antibacterial agent production.


Asunto(s)
Quitina , Nanopartículas del Metal , Quitina/farmacología , Nanopartículas del Metal/química , Plata/farmacología , Plata/química , Antibacterianos/farmacología , Antibacterianos/química
13.
Polymers (Basel) ; 15(7)2023 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-37050390

RESUMEN

Heparinase I (Hep I), which specifically degrades heparin to oligosaccharide or unsaturated disaccharide, has an important role in the production of low molecular weight heparin (LMWH). However, low productivity and stability of heparinase I hinders its applications. Here, a novel heparinase I (BxHep-I) was cloned from Bacteroides xylanisolvens and overexpressed in soluble form in Escherichia coli. The expression conditions of BxHep-I were optimized for an activity of 7144 U/L. BxHep-I had a specific activity of 57.6 U/mg at the optimal temperature and pH of 30 °C and pH 7.5, with the Km and Vmax of 0.79 mg/mL and 124.58 U/mg, respectively. BxHep-I catalytic activity could be enhanced by Ca2+ and Mg2+, while strongly inhibited by Zn2+ and Co2+. Purified BxHep-I displayed an outstanding thermostability with half-lives of 597 and 158 min at 30 and 37 °C, respectively, which are the highest half-lives ever reported for heparinases I. After storage at 4 °C for one week, BxHep-I retained 73% of its initial activity. Molecular docking revealed that the amino acids Asn25, Gln27, Arg88, Lys116, His156, Arg161, Gln228, Tyr356, Lys358, and Tyr362 form 13 hydrogen bonds with the substrate heparin disaccharides in the substrate binding domain and are mainly involved in the substrate binding of BxHep-I. These results suggest that the BxHep-I with high stability could be a candidate catalyst for the industrial production of LMWH.

14.
Prep Biochem Biotechnol ; 53(10): 1297-1305, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37040156

RESUMEN

Heparinase I (EC 4.2.2.7), is an enzyme that cleaves heparin, showing great potential for eco-friendly production of low molecular weight heparin (LMWH). However, owing to its poor catalytic activity and thermal stability, the industrial application of heparinase I has been severely hindered. To improve the catalytic activity, we proposed to engineer both the substrate and Ca2+ binding domains of heparinase I. Several heparinases I from different organisms were selected for multiple sequence alignment and molecular docking to screen the key residues in the binding domain. Nine single-point mutations were selected to enhance the catalytic activity of heparinase I. Among them, T250D was the most highly active one, whereas mutations around Ca2+ binding domain yielded two active mutants. Mutant D152S/R244K/T250D with significantly increased catalytic activity was obtained by combined mutation. The catalytic efficiency of the mutant was 118,875.8 min-1·µM-1, which was improved 5.26 times. Molecular modeling revealed that the improved activity and stability of the mutants were probably attributed to the formation of new hydrogen bonds. The highly active mutant had great potential applications in industry and the strategy could be used to improve the performance of other enzymes.


HighlightsImproved catalytic activity of heparinase I by engineering the binding domains of substrate and Ca2+.The mutant D152S/R244K/T250D showed the highest catalytic performance.The increased hydrogen bonds attribute to the increased activity.


Asunto(s)
Heparina de Bajo-Peso-Molecular , Heparina , Liasa de Heparina/química , Simulación del Acoplamiento Molecular , Heparina/química , Mutación
15.
Nat Commun ; 14(1): 1640, 2023 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-36964129

RESUMEN

Rice panicle architecture determines the grain number per panicle and therefore impacts grain yield. The OsER1-OsMKKK10-OsMKK4-OsMPK6 pathway shapes panicle architecture by regulating cytokinin metabolism. However, the specific upstream ligands perceived by the OsER1 receptor are unknown. Here, we report that the EPIDERMAL PATTERNING FACTOR (EPF)/EPF-LIKE (EPFL) small secreted peptide family members OsEPFL6, OsEPFL7, OsEPFL8, and OsEPFL9 synergistically contribute to rice panicle morphogenesis by recognizing the OsER1 receptor and activating the mitogen-activated protein kinase cascade. Notably, OsEPFL6, OsEPFL7, OsEPFL8, and OsEPFL9 negatively regulate spikelet number per panicle, but OsEPFL8 also controls rice spikelet fertility. A osepfl6 osepfl7 osepfl9 triple mutant had significantly enhanced grain yield without affecting spikelet fertility, suggesting that specifically suppressing the OsEPFL6-OsER1, OsEPFL7-OsER1, and OsEPFL9-OsER1 ligand-receptor pairs can optimize rice panicle architecture. These findings provide a framework for fundamental understanding of the role of ligand-receptor signaling in rice panicle development and demonstrate a potential method to overcome the trade-off between spikelet number and fertility.


Asunto(s)
Oryza , Proteínas de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Oryza/metabolismo , Ligandos , Grano Comestible/metabolismo , Transporte Biológico
16.
Cancer Sci ; 114(5): 1943-1957, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36642785

RESUMEN

Radioresistance remains a major obstacle to efficacious radiotherapy in non-small-cell lung cancer (NSCLC). DNA replication proteins are novel targets for radiosensitizers. POLQ is a DNA polymerase involved in DNA damage response and repair. We found that POLQ is overexpressed in NSCLC and is clinically correlated with high tumor stage, poor prognosis, increased tumor mutational burden, and ALK and TP5 mutation status; POLQ inhibition impaired lung tumorigenesis. Notably, POLQ expression was higher in radioresistant lung cancer cells than in wild-type cancer cells. Moreover, POLQ expression was further increased in radioresistant cells after radiation. Enhanced radioresistance is through a prolonged G2/M phase and faster repair of DNA damage, leading to reduced radiation-induced apoptosis. Novobiocin (NVB), a POLQ inhibitor, specifically targeted cancer cells. Genetic knockdown of POLQ or pharmacological inhibition by NVB decreased radioresistance in lung adenocarcinoma while causing little toxicity to normal pulmonary epithelial cells. In conclusion, POLQ is a promising and practical cancer-specific target to impair tumorigenesis and enhance radiosensitivity in NSCLC.


Asunto(s)
Adenocarcinoma del Pulmón , Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/radioterapia , Reparación del ADN/genética , Línea Celular Tumoral , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/radioterapia , Tolerancia a Radiación/genética , Carcinogénesis/genética
17.
Cancer Biother Radiopharm ; 38(10): 684-707, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34619053

RESUMEN

Background: To date, the clinical management of advanced hepatocellular carcinoma (HCC) patients remains challenging and the mechanisms of E2F transcription factor 1 (E2F1) underlying HCC are obscure. Materials and Methods: Our study integrated datasets mined from several public databases to comprehensively understand the deregulated expression status of E2F1. Tissue microarrays and immunohistochemistry staining was used to validate E2F1 expression level. The prognostic value of E2F1 was assessed. In-depth subgroup analyses were implemented to compare the differentially expressed levels of E2F1 in HCC patients with various tumor stages. Functional enrichments were used to address the predominant targets of E2F1 and shedding light on their potential roles in HCC. Results: We confirmed the elevated expression of E2F1 in HCC. Subgroup analyses indicated that elevated E2F1 level was independent of various stages in HCC. E2F1 possessed moderate discriminatory capability in differentiating HCC patients from non-HCC controls. Elevated E2F1 correlated with Asian race, tumor classification, neoplasm histologic grade, eastern cancer oncology group, and plasma AFP levels. Furthermore, high E2F1 correlated with poor survival condition and pooled HR signified E2F1 as a risk factor for HCC. Enrichment analysis of differentially expressed genes, coexpressed genes, and putative targets of E2F1 emphasized the importance of cell cycle pathway, where CCNE1 and CCNA2 served as hub genes. Conclusions: We confirmed the upregulation of E2F1 and explored the prognostic value of E2F1 in HCC patients. Two putative targeted genes (CCNE1 and CCNA2) of E2F1 were identified for their potential roles in regulating cell cycle and promote antiapoptotic activity in HCC patients.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patología , Ciclo Celular , Factor de Transcripción E2F1/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias Hepáticas/patología , Pronóstico
18.
Mol Plant ; 15(12): 1908-1930, 2022 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-36303433

RESUMEN

Ongoing soil salinization drastically threatens crop growth, development, and yield worldwide. It is therefore crucial that we improve salt tolerance in rice by exploiting natural genetic variation. However, many salt-responsive genes confer undesirable phenotypes and therefore cannot be effectively applied to practical agricultural production. In this study, we identified a quantitative trait locus for salt tolerance from the African rice species Oryza glaberrima and named it as Salt Tolerance and Heading Date 1 (STH1). We found that STH1 regulates fatty acid metabolic homeostasis, probably by catalyzing the hydrolytic degradation of fatty acids, which contributes to salt tolerance. Meanwhile, we demonstrated that STH1 forms a protein complex with D3 and a vital regulatory factor in salt tolerance, OsHAL3, to regulate the protein abundance of OsHAL3 via the 26S proteasome pathway. Furthermore, we revealed that STH1 also serves as a co-activator with the floral integrator gene Heading date 1 to balance the expression of the florigen gene Heading date 3a under different circumstances, thus coordinating the regulation of salt tolerance and heading date. Notably, the allele of STH1 associated with enhanced salt tolerance and high yield is found in some African rice accessions but barely in Asian cultivars. Introgression of the STH1HP46 allele from African rice into modern rice cultivars is a desirable approach for boosting grain yield under salt stress. Collectively, our discoveries not only provide conceptual advances on the mechanisms of salt tolerance and synergetic regulation between salt tolerance and flowering time but also offer potential strategies to overcome the challenges resulted from increasingly serious soil salinization that many crops are facing.


Asunto(s)
Oryza , Tolerancia a la Sal , Tolerancia a la Sal/genética , Oryza/genética , Hidrolasas , Familia
19.
Cardiovasc Diabetol ; 21(1): 188, 2022 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-36123740

RESUMEN

BACKGROUND: To determine the risk-assessment role of the immune-inflammatory biomarkers on myocardial damage in COVID-19 patients with diabetes mellitus (DM). METHODS: This retrospective study was conducted on 822 COVID-19 inpatients from 1 January to 10 March 2020 at Renmin Hospital of Wuhan University. The demographic data, clinical data, and immune-inflammatory parameters of participants were collected. The predictors of cardiac injury were assessed by Logistics regression analysis. RESULTS: A total of 246 COVID-19 inpatients were diagnosed with DM (29.9%). The incidence of cardiac injury was higher in patients with DM than in non-DM cases (28.9% vs 9.0%, p < 0.001), even grouped by age, gender, and the level of fasting plasma glucose (FPG). The mortality in diabetic COVID-19 patients with cardiac injury and without cardiac injury was 42.9% and 3.4%, respectively (p < 0.001). COVID-19 patients with DM and cardiac injury presented a decreased number of immunocyte subsets, lower C3 concentration, and a higher level of interleukin-6 (IL-6) and immunoglobulin A (IgA). The independent risk factors for cardiac injury in COVID-19 patients with DM were CD3+CD4+ T cells counts ≤ 288 cells/µl (adjusted Odds ratio (OR), 2.501; 95% confidence interval (CI) 1.282-4.877; p = 0.007) and IL-6 > 25.68mpg/ml (adjusted OR, 4.345; 95% CI 2.192-10.374; p < 0.001) (all Pinteraction < 0.05). CONCLUSIONS: For diabetic patients with COVID-19, cardiac injury not only induce severer immune-inflammatory responses, but also increase in-hospital mortality. The decreased number of CD3+CD4+ T cells and increased IL-6 are recommended to distinguish the people who refer to high risk of cardiac injury and mortality from those persons. However, it remains a testable theory whether decision-making strategies based on the risk status of cardiac injury in COVID-19 patients, especially with DM, would be expected to get better outcomes.


Asunto(s)
COVID-19 , Diabetes Mellitus , Biomarcadores , Glucemia , COVID-19/diagnóstico , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiología , Humanos , Inmunoglobulina A , Interleucina-6 , Estudios Retrospectivos
20.
World J Microbiol Biotechnol ; 38(11): 199, 2022 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-35996038

RESUMEN

As an important glycosaminoglycan hydrolase, chondroitin lyases can hydrolyze chondroitin sulfate (CS) and release disaccharides and oligosaccharides. They are further divided into chondroitin AC, ABC, and B lyases according to their spatial structure and substrate specificity. Chondroitin AC lyase can hydrolyze chondroitin sulfate A (CS-A), chondroitin sulfate C (CS-C), and hyaluronic acid (HA), making it an essential biocatalyst for the preparation of low molecular weight chondroitin sulfate, analysis of the structure of the chondroitin sulfate, treatment of spinal cord injury, and purification of heparin. This paper provides an overview of reported chondroitin AC lyases, including their properties and the challenges faced in industrial applications. Up to now, although many attempts have been adopted to improve the enzyme properties, the most important factors are still the low activity and stability. The relations between the stability of the enzyme and the spatial structure were also summarized and discussed. Also perspectives for remodeling the enzymes with protein engineering are included.


Asunto(s)
Sulfatos de Condroitina , Liasas , Condroitín Liasas/química , Condroitín Liasas/metabolismo , Sulfatos de Condroitina/química , Sulfatos de Condroitina/metabolismo , Ácido Hialurónico/química , Ácido Hialurónico/metabolismo , Liasas/metabolismo , Especificidad por Sustrato
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA