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1.
Plant Physiol Biochem ; 215: 108973, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39133980

RESUMO

Exopolysaccharide (EPS)-producing beneficial bacteria play a multifaceted role in improving plant growth and adaptive responses against different stressors. In this study, we isolated 25 bacterial strains from pea nodules and were further studied for their sodium chloride (NaCl) and cadmium (Cd) stress tolerance. Based on our results, Rhizobium fabae SR-22 (NCBI Accession number: MG063739.1) showed better tolerance toward salinity and Cd stress and produced a wide range of plant growth-promoting compounds. However, the amount of EPS varies during NaCl and Cd stress. It was important to note that NaCl and Cd beyond the tolerant level, affected the morphology and cellular viability of R. fabae. Interestingly, plant growth-promoting (PGP) substances (indole-3-acetic acid, ammonia, siderophore, and ACC deaminase) released by R. fabae were increased with increasing NaCl concentrations. In contrast, PGP substances were greatly decreased by increasing Cd dosages. Further, the beneficial effect of EPS-producing R. fabae in Triticum aestivum grown in soil treated with different levels of NaCl and Cd was assessed. Inoculation of R. fabae in wheat seedlings grown under higher NaCl and Cd concentrations showed improved growth compared to non-inoculated plants. R. fabae exhibited maximum effect in wheat plants grown under 2% NaCl and increased seed germination (8%), root length (13%), vigor indices (19%), root biomass (20%), chlorophyll-a (31%), total chlorophyll (27%) and carotenoid content. Additionally, R. fabae increased Cd and NaCl tolerance in wheat seedlings and improved their antioxidative responses. Conclusively, this work demonstrated that EPS-producing R. fabae showed a promising role in mitigating salinity and Cd-stress in wheat possibly by reducing salt and HM stress-induced abrasions and growth promotion via inorganic phosphate solubilization, and increased nutrient absorption. In the future, R. fabae equipped with these distinguishing characteristics may be used as effective bio-inoculants/bio-formulations in agriculture to address salinity and HM stress issues.


Assuntos
Cádmio , Polissacarídeos Bacterianos , Cloreto de Sódio , Triticum , Triticum/metabolismo , Triticum/crescimento & desenvolvimento , Triticum/microbiologia , Triticum/efeitos dos fármacos , Cádmio/toxicidade , Cádmio/metabolismo , Cloreto de Sódio/farmacologia , Polissacarídeos Bacterianos/metabolismo , Estresse Fisiológico
2.
Int J Biol Macromol ; 276(Pt 2): 133947, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39025189

RESUMO

Fluorosis disease can be prevented by the defluoridated water. Hence, the present work focused on the fabrication of hybrid materials using graphene oxide (GO) and Ce-based metal organic frameworks namely cerium fumarate (Ce-Fu) which gives GO/Ce-Fu for defluoridation of water. Further, the powdered GO/Ce-Fu was dispersed with alginate (Alg) and chitosan (CS) biopolymeric matrixes to give GO/Ce-Fu/Alg-CS biopolymeric hybrid beads for defluoridation investigations. The developed GO/Ce-Fu and GO/Ce-Fu/Alg-CS beads have defluoridation capacities (DCs) of 4.410 and 4.753 mg/g within 30 min. The fabricated GO/Ce-Fu and GO/Ce-Fu/Alg-CS beads were analyzed by XRD, FTIR, TGA, BET, SEM and EDAX studies. The performance of fluoride adsorption influencing parameters such as dosage, contact time, solution pH, interfering anions and temperature studies were optimized with batch scale. Thermodynamic, adsorption isotherms and kinetic studies were carried out using hybrid materials to find the nature and order of fluoride adsorption. The fluoride adsorption mechanism of GO/Ce-Fu and GO/Ce-Fu/Alg-CS beads was investigated. The performance of recyclability of the hybrid materials was examined. In addition, the field studies of hybrid materials were also explored to identify their field suitability nature.


Assuntos
Alginatos , Quitosana , Fluoretos , Grafite , Quitosana/química , Grafite/química , Alginatos/química , Fluoretos/química , Adsorção , Estruturas Metalorgânicas/química , Cinética , Biopolímeros/química , Concentração de Íons de Hidrogênio , Metais Terras Raras/química , Termodinâmica , Purificação da Água/métodos , Temperatura
3.
Sci Adv ; 10(23): eadn2955, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38848364

RESUMO

The hierarchical chromatin organization begins with formation of nucleosomes, which fold into chromatin domains punctuated by boundaries and ultimately chromosomes. In a hierarchal organization, lower levels shape higher levels. However, the dependence of higher-order 3D chromatin organization on the nucleosome-level organization has not been studied in cells. We investigated the relationship between nucleosome-level organization and higher-order chromatin organization by perturbing nucleosomes across the genome by deleting Imitation SWItch (ISWI) and Chromodomain Helicase DNA-binding (CHD1) chromatin remodeling factors in budding yeast. We find that changes in nucleosome-level properties are accompanied by changes in 3D chromatin organization. Short-range chromatin contacts up to a few kilo-base pairs decrease, chromatin domains weaken, and boundary strength decreases. Boundary strength scales with accessibility and moderately with width of nucleosome-depleted region. Change in nucleosome positioning seems to alter the stiffness of chromatin, which can affect formation of chromatin contacts. Our results suggest a biomechanical "bottom-up" mechanism by which nucleosome distribution across genome shapes 3D chromatin organization.


Assuntos
Montagem e Desmontagem da Cromatina , Cromatina , Genoma Fúngico , Nucleossomos , Saccharomyces cerevisiae , Nucleossomos/genética , Nucleossomos/metabolismo , Cromatina/genética , Cromatina/metabolismo , Cromatina/química , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Adenosina Trifosfatases
4.
Chemosphere ; 360: 142431, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38797209

RESUMO

Globally, agricultural productivity is facing a serious problem due to soil salinity which often causes osmotic, ionic, and redox imbalances in plants. Applying halotolerant rhizobacterial inoculants having multifarious growth-regulating traits is thought to be an effective and advantageous approach to overcome salinity stress. Here, salt-tolerant (tolerating 300 mM NaCl), exopolysaccharide (EPS) producing Rhizobium azibense SR-26 (accession no. MG063740) was assessed for salt alleviation potential by inoculating Phaseolus vulgaris (L.) plants raised under varying NaCl regimes. The metabolically active cells of strain SR-26 produced a significant amount of phytohormones (indole-3-acetic acid, gibberellic acid, and cytokinin), ACC deaminase, ammonia, and siderophore under salt stress. Increasing NaCl concentration variably affected the EPS produced by SR-26. The P-solubilization activity of the SR-26 strain was positively impacted by NaCl, as demonstrated by OD shift in NaCl-treated/untreated NBRIP medium. The detrimental effect of NaCl on plants was lowered by inoculation of halotolerant strain SR-26. Following soil inoculation, R. azibense significantly (p ≤ 0.05) enhanced seed germination (10%), root (19%) shoot (23%) biomass, leaf area (18%), total chlorophyll (21%), and carotenoid content (32%) of P. vulgaris raised in soil added with 40 mM NaCl concentration. Furthermore, strain SR-26 modulated the relative leaf water content (RLWC), proline, total soluble protein (TSP), and sugar (TSS) of salt-exposed plants. Moreover, R. azibense inoculation lowered the concentrations of oxidative stress biomarkers; MDA (29%), H2O2 content (24%), electrolyte leakage (31%), membrane stability (36%) and Na+ ion uptake (28%) when applied to 40 mM NaCl-treated plants. Further, R. azibense increases the salt tolerance mechanism of P. vulgaris by upregulating the antioxidant defensive responses. Summarily, it is reasonable to propose that EPS-synthesizing halotolerant R. azibense SR-26 should be applied as the most cost-effective option for increasing the yields of legume crops specifically P. vulgaris in salinity-challenged soil systems.


Assuntos
Antioxidantes , Phaseolus , Reguladores de Crescimento de Plantas , Polissacarídeos Bacterianos , Rhizobium , Tolerância ao Sal , Phaseolus/efeitos dos fármacos , Phaseolus/fisiologia , Phaseolus/crescimento & desenvolvimento , Rhizobium/fisiologia , Polissacarídeos Bacterianos/metabolismo , Antioxidantes/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Microbiologia do Solo , Homeostase , Salinidade , Cloreto de Sódio/farmacologia , Íons
5.
Vaccine ; 42(12): 3033-3038, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38594122

RESUMO

INTRODUCTION: Despite being a preventable and treatable disease, cholera remains a public health problem in Sudan. The objective of the outbreak investigation was to identify associated risk factors that would help institute appropriate control measures. MATERIAL AND METHODS: A case control study design was chosen to identify the risk factors for cholera in Gadarif State. RESULTS: Multi-variate analysis of identified two risk factors and three preventive factors for cholera in Gadarif City. RISK FACTORS: Buying foods or drinks from street vendors (OR = 71.36), 95 % CI: 16.58-307.14), living in an urban setting (Gadarif City) (OR = 5.38), 95 % CI: 2.10-13.81); and the preventive factors were: Washing hands with water after defecation but without soap (OR = 0.16), 95 % CI: 0.04-0.63) or with soap (OR = 0.01), 95 % CI: 0.00-0.03), washing hands before eating (OR = 0.15), 95 % CI: 0.05-0.51) and taking Oral Cholera Vaccine (OCV) (OR = 0.19, 95 % CI: 0.08-0.44). The effectiveness of OCV (VE) was (Unadjusted VE: 80 %, 95 % CI: 69 %-87 %) or (Adjusted VE = 81.0 %, 95 % CI: 56.0 %-92.0 %). DISCUSSION: Cholera outbreaks, especially in the setting of a complex humanitarian crises, can spread rapidly, resulting in many deaths, and quickly become a public health crisis. Implementation of a community-wide vaccination campaign using OCV as early as possible during the outbreak while implementing other control measures to target hotspots and at-risk populations would expedite halting outbreaks of cholera and save lives.


Assuntos
Vacinas contra Cólera , Cólera , Humanos , Cólera/epidemiologia , Cólera/prevenção & controle , Estudos de Casos e Controles , Sabões , Administração Oral , Surtos de Doenças/prevenção & controle
6.
Int J Biol Macromol ; 267(Pt 1): 131573, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38614188

RESUMO

DNA, vital for biological processes, encodes hereditary data for protein synthesis, shaping cell structure and function. Since revealing its structure, DNA has become a target for various therapeutically vital molecules, spanning antidiabetic to anticancer drugs. These agents engage with DNA-associated proteins, DNA-RNA hybrids, or bind directly to the DNA helix, triggering diverse downstream effects. These interactions disrupt vital enzymes and proteins essential for maintaining cell structure and function. Analysing drug-DNA interactions has significantly advanced our understanding of drug mechanisms. Glipizide, an antidiabetic drug, is known to cause DNA damage in adipocytes. However, its extract mechanism of DNA interaction is unknown. This study delves into the interaction between glipizide and DNA utilizing various biophysical tools and computational technique to gain insights into the interaction mechanism. Analysis of UV-visible and fluorescence data reveals the formation of complex between DNA and glipizide. The binding affinity of glipizide to DNA was of moderate strength. Examination of thermodynamic parameters at different temperatures suggests that the binding was entropically spontaneous and energetically favourable. Various experiments such as thermal melting assays, viscosity measurement, and dye displacement assays confirmed the minor grove nature of binding of glipizide with DNA. Molecular dynamics studies confirmed the glipizide forms stable complex with DNA when simulated by mimicking the physiological conditions. The binding was mainly favoured by hydrogen bonds and glipizide slightly reduced nucleotide fluctuations of DNA. The study deciphers the mechanism of interaction of glipizide with DNA at molecular levels.


Assuntos
DNA , Glipizida , Simulação de Dinâmica Molecular , Termodinâmica , Glipizida/química , Glipizida/farmacologia , DNA/química , DNA/metabolismo , Biologia Computacional/métodos , Simulação de Acoplamento Molecular , Conformação de Ácido Nucleico , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia
7.
ACS Omega ; 9(7): 8557-8573, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38405473

RESUMO

Heavy metals (HMs) pose a serious threat to agricultural productivity. Therefore, there is a need to find sustainable approaches to combat HM stressors in agriculture. In this study, we isolated Trichoderma sp. TF-13 from metal-polluted rhizospheric soil, which has the ability to resist 1600 and 1200 µg mL-1 cadmium (Cd) and lead (Pb), respectively. Owing to its remarkable metal tolerance, this fungal strain was applied for bioremediation of HMs in Vigna radiata (L.). Strain TF-13 produced siderophore, salicylic acid (SA; 43.4 µg mL-1) and 2,3-DHBA (21.0 µg mL-1), indole-3-acetic acid, ammonia, and ACC deaminase under HM stressed conditions. Increasing concentrations of tested HM ions caused severe reduction in overall growth of plants; however, Trichoderma sp. TF-13 inoculation significantly (p ≤ 0.05) increased the growth and physiological traits of HM-treated V. radiata. Interestingly, Trichoderma sp. TF-13 improved germination rate (10%), root length (26%), root biomass (32%), and vigor index (12%) of V. radiata grown under 25 µg Cd kg-1 soil. Additionally, Trichoderma inoculation showed a significant (p ≤ 0.05) increase in total chlorophyll, chl a, chl b, carotenoid content, root nitrogen (N), and root phosphorus (P) of 100 µg Cd kg-1 soil-treated plants over uninoculated treatment. Furthermore, enzymatic and nonenzymatic antioxidant activities of Trichoderma inoculated in metal-treated plants were improved. For instance, strain TF-13 increased proline (37%), lipid peroxidation (56%), catalase (35%), peroxidase (42%), superoxide dismutase (27%), and glutathione reductase (39%) activities in 100 µg Pb kg-1 soil-treated plants. The uptake of Pb and Cd in root/shoot tissues was decreased by 34/39 and 47/38% in fungal-inoculated and 25 µg kg-1 soil-treated plants. Thus, this study demonstrates that stabilizing metal mobility in the rhizosphere through Trichoderma inoculation significantly reduced the detrimental effects of Cd and Pb toxicity in V. radiata and also enhanced development under HM stress conditions.

8.
RSC Adv ; 13(51): 35841-35852, 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38090073

RESUMO

Antimicrobial resistance (AMR), a condition in which the efficacy of antimicrobial drugs in fighting microorganisms is reduced, has become a global challenge. Multidrug resistance (MDR) has been developing in microorganisms, where they can resist multiple medications. In particular, there has been a rise in MDR as well as extensively drug-resistant (XDR) strains of Pseudomonas aeruginosa in some regions, with prevalence rates ranging from 15% to 30%. The application of nanotechnology ranges from diagnostics to drug-delivery systems, revolutionizing healthcare, and improving disease treatment. We aimed to investigate the efficacy of titanium dioxide nanoparticles (TiO2-NPs) against various virulent traits of P. aeruginosa and S. marcescens. More than 50% reduction in the production of virulent pigments of P. aeruginosa was recorded following the treatment of TiO2-NPs. Additionally, elastases and exoproteases were inhibited by 58.21 and 74.36%, respectively. A similar result was observed against the rhamnolipid production and swimming motility of P. aeruginosa. The effect of TiO2-NPs was also validated against another opportunistic pathogen, S. marcescens, where the production of prodigiosin was reduced by 64.78%. Also, a roughly 75% attenuation of proteolytic activity and more than 50% reduction in swarming motility were found. In the control group, the cell surface hydrophobicity was 77.72%, which decreased to 24.67% with the addition of 64 µg ml-1 TiO2-NPs in culture media. The hydrophobicity index of microorganisms is crucial for their initial attachment and the formation of biofilms. In conclusion, TiO2-NPs demonstrated potential in a multi-target approach against P. aeruginosa and S. marcescens, suggesting their advantages in the prevention and treatment of infections. These nanomaterials could have vital importance in the development of novel antibacterial agents to combat drug-resistant bacteria.

9.
Pharmaceuticals (Basel) ; 16(4)2023 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-37111322

RESUMO

Multidrug-resistant bacterial infections are on the rise around the world. Chronic infections caused by these pathogens through biofilm mediation often complicate the situation. In natural settings, biofilms are often formed with different species of bacteria existing synergistically or antagonistically. Biofilms on diabetic foot ulcers are formed predominantly by two opportunistic pathogens, Staphylococcus aureus and Enterococcus faecalis. Bacteriophages and phage-based proteins, including endolysins, have been found to be active against biofilms. In this study, we evaluated the activity of two engineered enzybiotics either by themselves or as a combination against a dual biofilm formed by S. aureus and E. faecalis in an inert glass surface. An additive effect in rapidly disrupting the preformed dual biofilm was observed with the cocktail of proteins, in comparison with mono treatment. The cocktail-treated biofilms were dispersed by more than 90% within 3 h of treatment. Apart from biofilm disruption, bacterial cells embedded in the biofilm matrix were also effectively reduced by more than 90% within 3 h of treatment. This is the first instance where a cocktail of engineered enzybiotics has been effectively used to impede the structural integrity of a dual biofilm.

10.
FEBS Lett ; 597(7): 962-974, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36723387

RESUMO

IRE1 is a transmembrane signalling protein that activates the unfolded protein response under endoplasmic reticulum stress. IRE1 is endowed with kinase and endoribonuclease activities. The ribonuclease activity of IRE1 can switch substrate specificities to carry out atypical splicing of Xbp1 mRNA or trigger the degradation of specific mRNAs. The mechanisms regulating the distinct ribonuclease activities of IRE1 have yet to be fully understood. Here, we report the Bcl-2 family protein Bid as a novel recruit of the IRE1 complex, which directly interacts with the cytoplasmic domain of IRE1. Bid binding to IRE1 leads to a decrease in IRE1 phosphorylation in a way that it can only perform Xbp1 splicing while mRNA degradation activity is repressed. The RNase outputs of IRE1 have been found to regulate the homeostatic-apoptotic switch. This study, thus, provides insight into IRE1-mediated cell survival.


Assuntos
Proteínas Serina-Treonina Quinases , Resposta a Proteínas não Dobradas , Estresse do Retículo Endoplasmático/fisiologia , Endorribonucleases/genética , Endorribonucleases/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Ribonucleases/metabolismo , Proteína 1 de Ligação a X-Box/genética , Proteína 1 de Ligação a X-Box/metabolismo , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo
11.
Antibiotics (Basel) ; 12(2)2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36830298

RESUMO

The emergence of antibiotic resistance in enterococci is a great concern encountered worldwide. Almost all enterococci exhibit significant levels of resistance to penicillin, ampicillin, semi-synthetic penicillin and most cephalosporins, primarily due to the expression of low-affinity penicillin-binding proteins. The development of new and novel antibacterial agents against enterococci is a significant need of the hour. In this research, we have constructed a modular peptide against Enterococcus faecalis. The enzymatic domain of the constructed peptide BP404 is from the bacteriocin BacL1 and the cell wall binding domain from endolysin PlyV12 of phage ϕ1. The protein BP404 was found to be active against two tested strains of Enterococcus faecalis, with a reduction in cell density amounting to 85% and 65%. The cell wall binding assay confirms the binding of the protein to Enterococcus faecalis, which was not seen towards the control strain Escherichia coli, invariably pointing to the specificity of BP404. To the best of our knowledge, this is one of the first instances of the development of a chimeric peptide against Enterococcus faecalis. This study points out that novel proteins can be genetically engineered against clinically relevant enterococci.

12.
J Biol Chem ; 299(3): 102988, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36758804

RESUMO

RNA-binding proteins (RBPs) are emerging as important players in regulating eukaryotic gene expression and genome stability. Specific RBPs have been shown to mediate various chromatin-associated processes ranging from transcription to gene silencing and DNA repair. One of the prominent classes of RBPs is the KH domain-containing proteins. Vigilin, an evolutionarily conserved KH domain-containing RBP has been shown to be associated with diverse biological processes like RNA transport and metabolism, sterol metabolism, chromosome segregation, and carcinogenesis. We have previously reported that vigilin is essential for heterochromatin-mediated gene silencing in fission yeast. More recently, we have identified that vigilin in humans plays a critical role in efficient repair of DNA double-stranded breaks and functions in homology-directed DNA repair. In this review, we highlight the multifaceted functions of vigilin and discuss the findings in the context of gene expression, genome organization, cancer, and autism-related disorders.


Assuntos
Transtorno Autístico , Schizosaccharomyces , Humanos , Transtorno Autístico/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Inativação Gênica , Schizosaccharomyces/genética , Instabilidade Genômica
13.
J Biol Chem ; 299(3): 102937, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36690274

RESUMO

Defective autophagy and lipotoxicity are the hallmarks of nonalcoholic fatty liver disease. However, the precise molecular mechanism for the defective autophagy in lipotoxic conditions is not fully known. In the current study, we elucidated that activation of the mammalian target of rapamycin complex 1 (mTORC1)-G9a-H3K9me2 axis in fatty acid-induced lipotoxicity blocks autophagy by repressing key autophagy genes. The fatty acid-treated cells show mTORC1 activation, increased histone methyltransferase G9a levels, and suppressed autophagy as indicated by increased accumulation of the key autophagic cargo SQSTM1/p62 and decreased levels of autophagy-related proteins LC3II, Beclin1, and Atg7. Our chromatin immunoprecipitation analysis showed that decrease in autophagy was associated with increased levels of the G9a-mediated repressive H3K9me2 mark and decreased RNA polymerase II occupancy at the promoter regions of Beclin1 and Atg7 in fatty acid-treated cells. Inhibition of mTORC1 in fatty acid-treated cells decreased G9a-mediated H3K9me2 occupancy and increased polymerase II occupancy at Beclin1 and Atg7 promoters. Furthermore, mTORC1 inhibition increased the expression of Beclin1 and Atg7 in fatty acid-treated cells and decreased the accumulation of SQSTM1/p62. Interestingly, the pharmacological inhibition of G9a alone in fatty acid-treated cells decreased the H3K9me2 mark at Atg7 and Beclin1 promoters and restored the expression of Atg7 and Beclin1. Taken together, our findings have identified the mTORC1-G9a-H3K9me2 axis as a negative regulator of the autophagy pathway in hepatocellular lipotoxicity and suggest that the G9a-mediated epigenetic repression is mechanistically a key step during the repression of autophagy in lipotoxic conditions.


Assuntos
Autofagia , Ácidos Graxos , Histona Metiltransferases , Histonas , Alvo Mecanístico do Complexo 1 de Rapamicina , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Histonas/metabolismo , Ácidos Graxos/toxicidade , Autofagia/fisiologia , Epigênese Genética , Histona Metiltransferases/metabolismo , Hepatócitos/fisiologia , Células Hep G2 , Regulação da Expressão Gênica/efeitos dos fármacos , Palmitatos/toxicidade , Proteína Beclina-1/genética , Proteína Beclina-1/metabolismo , Regiões Promotoras Genéticas , Autofagossomos/genética , Autofagossomos/metabolismo , Humanos
14.
Materials (Basel) ; 15(23)2022 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-36499868

RESUMO

Long-term corrosion protection of metals might be provided by nanocomposite coatings having synergistic qualities. In this perspective, rapeseed oil-based polyurethane (ROPU) and nanocomposites with calcium and magnesium ions were designed. The structure of these nanocomposites was established through Fourier-transform infrared spectroscopy (FT-IR). The morphological studies were carried out using scanning electron microscopy (SEM) as well as transmission electron microscopy (TEM). Their thermal characteristics were studied using thermogravimetric analysis (TGA). Electrochemical experiments were applied for the assessment of the corrosion inhibition performance of these coatings in 3.5 wt. % NaCl solution for 7 days. After completion of the test, the results revealed a very low icorr value of 7.73 × 10-10 A cm-2, a low corrosion rate of 8.342 × 10-5 mpy, impedance 1.0 × 107 Ω cm2, and phase angle (approx 90°). These findings demonstrated that nanocomposite coatings outperformed ordinary ROPU and other published methods in terms of anticorrosive activity. The excellent anti-corrosive characteristic of the suggested nanocomposite coatings opens up new possibilities for the creation of advanced high-performance coatings for a variety of metal industries.

15.
ACS Omega ; 7(40): 35825-35833, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36249394

RESUMO

An efficient and green methodology to assemble various functionalized naphthalimide-centered acridine-1,8-dione derivatives involving a one-pot multicomponent protocol has successfully been developed. Herein, a variety of aromatic aldehydes, 1,3-diketones, 1,8-naphthanoic anhydride, and hydrazine hydrate have been condensed under a reusable, inexpensive, and biodegradable deep eutectic solvent (DES) of N,N'-dimethyl urea and l-(+)-tartaric acid to obtain the desired targets under operationally mild reaction conditions with outstanding conversions. Strikingly, in this strategy, the DES plays a dual role of a catalyst and solvent and was recycled efficiently in four consecutive runs with no substantial drop in the yield of the desired product. Interestingly, the easy recovery and high reusability of the DES make this simple yet efficient protocol environmentally desirable. Moreover, the preliminary photophysical properties of thus-prepared valuable molecules have also been investigated by ultraviolet-visible (UV-vis) and fluorescence spectroscopy.

16.
iScience ; 25(4): 104142, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35434547

RESUMO

Hyperthermia inhibits DNA double-strand break (DSB) repair that utilizes homologous recombination (HR) pathway by a poorly defined mechanism(s); however, the mechanisms for this inhibition remain unclear. Here we report that hyperthermia decreases H4K16 acetylation (H4K16ac), an epigenetic modification essential for genome stability and transcription. Heat-induced reduction in H4K16ac was detected in humans, Drosophila, and yeast, indicating that this is a highly conserved response. The examination of histone deacetylase recruitment to chromatin after heat-shock identified SIRT1 as the major deacetylase subsequently enriched at gene-rich regions. Heat-induced SIRT1 recruitment was antagonized by chromatin remodeler SMARCAD1 depletion and, like hyperthermia, the depletion of the SMARCAD1 or combination of the two impaired DNA end resection and increased replication stress. Altered repair protein recruitment was associated with heat-shock-induced γ-H2AX chromatin changes and DSB repair processing. These results support a novel mechanism whereby hyperthermia impacts chromatin organization owing to H4K16ac deacetylation, negatively affecting the HR-dependent DSB repair.

17.
Life (Basel) ; 11(12)2021 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-34947915

RESUMO

Development of multidrug antibiotic resistance in bacteria is a predicament encountered worldwide. Researchers are in a constant hunt to develop effective antimicrobial agents to counter these dreadful pathogenic bacteria. Here we describe a chimerically engineered multimodular enzybiotic to treat a clinical isolate of methicillin-resistant Staphylococcus aureus (S. aureus). The cell wall binding domain of phage ϕ11 endolysin was replaced with a truncated and more potent cell wall binding domain from a completely unrelated protein from a different phage. The engineered enzybiotic showed strong activity against clinically relevant methicillin-resistant Staphylococcus aureus. In spite of a multimodular peptidoglycan cleaving catalytic domain, the engineered enzybiotic could not exhibit its activity against a veterinary isolate of S. aureus. Our studies point out that novel antimicrobial proteins can be genetically engineered. Moreover, the cell wall binding domain of the engineered protein is indispensable for a strong binding and stability of the proteins.

18.
Polymers (Basel) ; 13(19)2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34641141

RESUMO

The environmental and health hazards associated with petro-based chemicals have motivated the researchers to replace them partially or wholly with renewable resource-based polymers. Vegetable oils serve as an excellent alternative to this end as they are cost effective, eco-friendly, easily available and rich with functional groups amenable to chemical reactions. The aim of the research work is to prepare Canola oil [CANO] derived poly (ester-ether-amide-urethane) (CPEEUA) nanocomposite coating material using N,N-bis (2-hydroxyethyl) fatty amide [CFA] obtained from CANO, Lactic acid [LA], and reinforced with Fumed Silica [FS]. CPEEUA was obtained by esterification, etherification, and urethanation reactions and its structure was confirmed from FTIR and NMR spectral analyses. CPEEUA/FS coatings were found to be scratch resistant, flexible, well-adhered to mild steel panels, and hydrophobic with 2.0-2.5 kg scratch hardness, 150lb/inch impact resistance and >90° contact angle value. They exhibited good corrosion protection in 3.5 wt% NaCl solution as investigated by Potentiodynamic Polarization and Electrochemical Impedance tests. CPEEUA coatings are safe for usage up to 200 °C.

19.
DNA Repair (Amst) ; 107: 103205, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34399315

RESUMO

The accurate repair of DNA damage specifically the chromosomal double-strand breaks (DSBs) arising from exposure to physical or chemical agents, such as ionizing radiation (IR) and radiomimetic drugs is critical in maintaining genomic integrity. The DNA DSB response and repair is facilitated by hierarchical signaling networks that orchestrate chromatin structural changes specifically histone modifications which impact cell-cycle checkpoints through enzymatic activities to repair the broken DNA ends. Various histone posttranslational modifications such as phosphorylation, acetylation, methylation and ubiquitylation have been shown to play a role in DNA damage repair. Recent studies have provided important insights into the role of histone-specific modifications in sensing DNA damage and facilitating the DNA repair. Histone modifications have been shown to determine the pathway choice for repair of DNA DSBs. This review will summarize the role of important histone acetyltransferases MOF and Tip60 mediated acetylation in repair of DNA DSBs in eukaryotic cells.


Assuntos
Histona Acetiltransferases
20.
Genes (Basel) ; 12(7)2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34209979

RESUMO

Packaging of the eukaryotic genome with histone and other proteins forms a chromatin structure that regulates the outcome of all DNA mediated processes. The cellular pathways that ensure genomic stability detect and repair DNA damage through mechanisms that are critically dependent upon chromatin structures established by histones and, particularly upon transient histone post-translational modifications. Though subjected to a range of modifications, histone methylation is especially crucial for DNA damage repair, as the methylated histones often form platforms for subsequent repair protein binding at damaged sites. In this review, we highlight and discuss how histone methylation impacts the maintenance of genome integrity through effects related to DNA repair and repair pathway choice.


Assuntos
Instabilidade Genômica , Código das Histonas , Animais , Reparo do DNA , Histonas/metabolismo , Humanos , Metilação
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