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1.
PLoS Biol ; 21(8): e3002231, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37590294

RESUMO

Mycobacterium tuberculosis (Mtb) defends host-mediated killing by repressing the autophagolysosome machinery. For the first time, we report NCoR1 co-repressor as a crucial host factor, controlling Mtb growth in myeloid cells by regulating both autophagosome maturation and lysosome biogenesis. We found that the dynamic expression of NCoR1 is compromised in human peripheral blood mononuclear cells (PBMCs) during active Mtb infection, which is rescued upon prolonged anti-mycobacterial therapy. In addition, a loss of function in myeloid-specific NCoR1 considerably exacerbates the growth of M. tuberculosis in vitro in THP1 differentiated macrophages, ex vivo in bone marrow-derived macrophages (BMDMs), and in vivo in NCoR1MyeKO mice. We showed that NCoR1 depletion controls the AMPK-mTOR-TFEB signalling axis by fine-tuning cellular adenosine triphosphate (ATP) homeostasis, which in turn changes the expression of proteins involved in autophagy and lysosomal biogenesis. Moreover, we also showed that the treatment of NCoR1 depleted cells by Rapamycin, Antimycin-A, or Metformin rescued the TFEB activity and LC3 levels, resulting in enhanced Mtb clearance. Similarly, expressing NCoR1 exogenously rescued the AMPK-mTOR-TFEB signalling axis and Mtb killing. Overall, our data revealed a central role of NCoR1 in Mtb pathogenesis in myeloid cells.


Assuntos
Mycobacterium tuberculosis , Correpressor 1 de Receptor Nuclear , Animais , Humanos , Camundongos , Proteínas Quinases Ativadas por AMP , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Leucócitos Mononucleares , Células Mieloides , Serina-Treonina Quinases TOR , Correpressor 1 de Receptor Nuclear/metabolismo
2.
Nucleic Acids Res ; 50(3): 1551-1561, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35048970

RESUMO

During the course of the COVID-19 pandemic, large-scale genome sequencing of SARS-CoV-2 has been useful in tracking its spread and in identifying variants of concern (VOC). Viral and host factors could contribute to variability within a host that can be captured in next-generation sequencing reads as intra-host single nucleotide variations (iSNVs). Analysing 1347 samples collected till June 2020, we recorded 16 410 iSNV sites throughout the SARS-CoV-2 genome. We found ∼42% of the iSNV sites to be reported as SNVs by 30 September 2020 in consensus sequences submitted to GISAID, which increased to ∼80% by 30th June 2021. Following this, analysis of another set of 1774 samples sequenced in India between November 2020 and May 2021 revealed that majority of the Delta (B.1.617.2) and Kappa (B.1.617.1) lineage-defining variations appeared as iSNVs before getting fixed in the population. Besides, mutations in RdRp as well as RNA-editing by APOBEC and ADAR deaminases seem to contribute to the differential prevalence of iSNVs in hosts. We also observe hyper-variability at functionally critical residues in Spike protein that could alter the antigenicity and may contribute to immune escape. Thus, tracking and functional annotation of iSNVs in ongoing genome surveillance programs could be important for early identification of potential variants of concern and actionable interventions.


Assuntos
Evolução Molecular , Variação Genética/genética , Genoma Viral/genética , Interações Hospedeiro-Patógeno/genética , SARS-CoV-2/genética , Desaminase APOBEC-1/genética , Adenosina Desaminase/genética , Animais , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/virologia , Chlorocebus aethiops , RNA-Polimerase RNA-Dependente de Coronavírus/genética , Bases de Dados Genéticas , Evasão da Resposta Imune/genética , Índia/epidemiologia , Filogenia , Proteínas de Ligação a RNA/genética , SARS-CoV-2/classificação , SARS-CoV-2/crescimento & desenvolvimento , Glicoproteína da Espícula de Coronavírus/genética , Células Vero
3.
J Am Chem Soc ; 145(33): 18549-18559, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37579341

RESUMO

Organic-inorganic metal hybrids with their tailorable lattice dimensionality and intrinsic spin-splitting properties are interesting material platforms for spintronic applications. While the spin decoherence process is extensively studied in lead- and tin-based hybrids, these systems generally show short spin decoherence lifetimes, and their correlation with the lattice framework is still not well-understood. Herein, we synthesized magnetic manganese hybrid single crystals of (4-fluorobenzylamine)2MnCl4, ((R)-3-fluoropyrrolidinium)MnCl3, and (pyrrolidinium)2MnCl4, which represent a change in lattice dimensionality from 2D and 1D to 0D, and studied their spin decoherence processes using continuous-wave electron spin resonance spectroscopy. All manganese hybrids exhibit nanosecond-scale spin decoherence time τ2 dominated by the symmetry-directed spin exchange interaction strengths of Mn2+-Mn2+ pairs, which is much longer than lead- and tin-based metal hybrids. In contrast to the similar temperature variation laws of τ2 in 2D and 0D structures, which first increase and gradually drop afterward, the 1D structure presents a monotonous rise of τ2 with the temperatures, indicating the strong correlation of spin decoherence with the lattice rigidity of the inorganic framework. This is also rationalized on the basis that the spin decoherence is governed by the competitive contributions from motional narrowing (prolonging the τ2) and electron-phonon coupling interaction (shortening the τ2), both of which are thermally activated, with the difference that the former is more pronounced in rigid crystalline lattices.

4.
FASEB J ; 36(10): e22566, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36165231

RESUMO

CMTM6, a type 3 transmembrane protein, is known to stabilize the expression of programmed cell death ligand 1 (PD-L1) and hence facilitates the immune evasion of tumor cells. Recently, we demonstrated that CMTM6 is a major driver of cisplatin resistance in oral squamous cell carcinomas (OSCC). However, the detailed mechanism of how CMTM6 rewires cisplatin resistance in OSCC is yet to be explored. RNA sequencing analysis of cisplatin-resistant OSCC lines stably expressing Nt shRNA and CMTM6 shRNA revealed that CMTM6 might be a potential regulator of the ribosome biogenesis network. Knocking down CMTM6 significantly inhibited transcription of 47S precursor rRNA and hindered the nucleolar structure, indicating reduced ribosome biogenesis. When CMTM6 was ectopically over-expressed in CMTM6KD cells, almost all ribosomal machinery components were rescued. Mechanistically, CMTM6 induced the expression of C-Myc, which promotes RNA polymerase I mediated rDNA transcription. In addition to this, CMTM6 was also found to regulate the AKT-mTORC1-dependent ribosome biogenesis and protein synthesis in cisplatin-resistant lines. The nude mice and zebrafish xenograft experiments indicate that blocking ribosome synthesis either by genetic inhibitor (CMTM6KD) or pharmacological inhibitor (CX-5461) significantly restores cisplatin-mediated cell death in chemoresistant OSCC. Overall, our study suggests that CMTM6 is a major regulator of the ribosome biogenesis network and targeting the ribosome biogenesis network is a viable target to overcome chemoresistance in OSCC. The novel combination of CX-5461 and cisplatin deserves further clinical investigation in advanced OSCC.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Animais , Antígeno B7-H1 , Carcinoma de Células Escamosas/genética , Morte Celular , Linhagem Celular Tumoral , Cisplatino/farmacologia , DNA Ribossômico , Humanos , Ligantes , Alvo Mecanístico do Complexo 1 de Rapamicina , Camundongos , Camundongos Nus , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/patologia , Proteínas Proto-Oncogênicas c-akt , RNA Polimerase I , RNA Interferente Pequeno , Ribossomos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Peixe-Zebra/genética
5.
Eur J Immunol ; 51(5): 1126-1142, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33527393

RESUMO

Dendritic cell (DC) activation and cytokine production is tightly regulated. In this study, we found that Zbtb10 expression is activation dependent and it is essential for the immunogenic function of cDC1. Zbtb10 knockdown (KD) significantly reduced the expression of co-stimulatory genes CD80 and CD86 along with cytokines including IL-12, IL-6, and IL-10, in activated cDC1 Mutu-DC line. Consequently, the clonal expansion of CD44+ effector T cells in co-cultured CD4+ T cells was drastically reduced owing to significantly reduced IL-2. At the same time, these CD44+ effector T cells were unable to differentiate toward Tbet+ IFNγ+ Th1 subtype. Instead, an increased frequency of Th2 cells expressing GATA3+ and IL-13+ was observed. Interestingly, in Zbtb10 KD condition the co-cultured T cells depicted increased expression of PD1 and LAG3, the T-cell anergic markers. Moreover, the global transcriptome analysis identified that Zbtb10 is pertinent for DC activation and its depletion in cDC1 completely shuts down their immune responses. Mechanistic analysis revealed that Zbtb10 KD enhanced the expression of NKRF (NF-κB repressing factor) leading to drastic suppression of NF-κB related genes. Zbtb10 KD abrogated p65 and RelB nuclear translocation, thereby controlling the activation and maturation of cDC1 and the ensuing adaptive T cell responses.


Assuntos
Citocinas/biossíntese , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Fatores de Transcrição/metabolismo , Animais , Biomarcadores , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Linhagem Celular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Ativação Linfocitária/imunologia , Camundongos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
6.
FASEB J ; 35(7): e21713, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34105201

RESUMO

Syrian golden hamsters (Mesocricetus auratus) infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) manifests lung pathology. In this study, efforts were made to check the infectivity of a local SARS-CoV-2 isolate in a self-limiting and non-lethal hamster model and evaluate the differential expression of lung proteins during acute infection and convalescence. The findings of this study confirm the infectivity of this isolate in vivo. Analysis of clinical parameters and tissue samples show the pathophysiological manifestation of SARS-CoV-2 infection similar to that reported earlier in COVID-19 patients and hamsters infected with other isolates. However, diffuse alveolar damage (DAD), a common histopathological feature of human COVID-19 was only occasionally noticed. The lung-associated pathological changes were very prominent on the 4th day post-infection (dpi), mostly resolved by 14 dpi. Here, we carried out the quantitative proteomic analysis of the lung tissues from SARS-CoV-2-infected hamsters on day 4 and day 14 post-infection. This resulted in the identification of 1585 proteins of which 68 proteins were significantly altered between both the infected groups. Pathway analysis revealed complement and coagulation cascade, platelet activation, ferroptosis, and focal adhesion as the top enriched pathways. In addition, we also identified altered expression of two pulmonary surfactant-associated proteins (Sftpd and Sftpb), known for their protective role in lung function. Together, these findings will aid in understanding the mechanism(s) involved in SARS-CoV-2 pathogenesis and progression of the disease.


Assuntos
COVID-19/metabolismo , COVID-19/patologia , Interações Hospedeiro-Patógeno , Pulmão/metabolismo , Pulmão/virologia , Proteômica , SARS-CoV-2/patogenicidade , Animais , COVID-19/virologia , Cricetinae , Modelos Animais de Doenças , Feminino , Pulmão/patologia , Masculino , Proteoma/análise , Proteoma/biossíntese , Reprodutibilidade dos Testes , Carga Viral
7.
Arch Microbiol ; 204(1): 72, 2021 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-34951686

RESUMO

Kappaphycus alvarezii seaweed extract (KSWE) is known to enhance crop productivity and impart stress tolerance. Close to one quarter of foliar spray applied to maize falls on the soil, either as drift or from leaf as drip. It was hypothesized that the drift spray would profoundly influence soil microbes under stress. An experiment was conducted with five treatments, with or without KSWE application at critical stages of maize grown under soil moisture stress and compared with an irrigated control. An Illumina platform was employed for the analysis of the V3-V4 region of 16S rRNA gene from the soil metagenome. A total of 345,552 operational taxonomic units were generated which were classified into 55 phyla, 152 classes, 240 orders, 305 families and 593 genera. Shannon's index and Shannon's equitability indicated increased soil bacterial diversity after multiple KSWE applications under conditions of abiotic duress. The abundance of the genera Alicyclobacillus, Anaerolinea, Bacillus, Balneimonas, Nitrospira, Rubrobacter and Steroidobacter decreased (49-79%) under drought imposed at the V5,10 and 15 stages of maize over the irrigated control, while it significantly improved when followed by KSWE application under drought. Flavobacterium, Nitrosomonas, Nitrosovibrio, Rubrobacter genera and several other bacterial taxa which are important for plant growth promotion and nutrient cycling were found to be enriched by KSWE application under drought conditions. Treatments having enriched microbial abundance due to KSWE application under stress recorded higher soil enzymatic activities and plant cob yield, suggesting the contribution of altered soil ecology mediated by KSWE as one of the reasons for improvement of yield.


Assuntos
Fertilizantes , Metagenômica , Alga Marinha , Microbiologia do Solo , RNA Ribossômico 16S/genética , Solo
8.
Phys Rev Lett ; 124(1): 017203, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31976695

RESUMO

We report on temperature dependent measurements of the longitudinal spin Seebeck effect (LSSE) in the mixed valent manganite La_{0.7}Ca_{0.3}MnO_{3}. By disentangling the contribution arising due to the anisotropic Nernst effect, we observe that in the low temperature regime, the LSSE exhibits a T^{0.5} dependence, which matches well with that predicted by the magnon-driven spin current model. Across the double exchange driven paramagnetic-ferromagnetic transition, the LSSE exponent is significantly higher than the magnetization one, and also depends on the thickness of the spin-to-charge conversion layer. These observations highlight the importance of individually ascertaining the temperature evolution of different mechanisms-especially the spin mixing conductance-which contribute to the measured spin Seebeck signal.

9.
Physiol Plant ; 170(4): 462-473, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32812254

RESUMO

Temperature is the most critical factor that directly affects the physiological functioning and metabolic activities of any organism. With rising global temperature, understanding the heat stress response of an organism is critically important. In the present study, we investigated differences in the early changes occurring upon heat stress in the green microalga Acutodesmus dimorphus, a potential strain for biofuel production. The cells were heat-stressed at 45 and 50°C for 24 h and the temporal response of cells in terms of growth, pigments content, levels of oxidative stress biomarkers i.e., reactive oxygen species (ROS) and the response of enzymatic and non-enzymatic antioxidant scavengers were evaluated. The results revealed that after 24 h of heat stress at 45°C, the accumulations of chlorophyll a and carotenoids remained stable; all three ROS increased with the higher activities of various enzymatic and non-enzymatic antioxidants. On the contrary, at a higher temperature of 50°C, the accumulations of chlorophyll a, carotenoids and non-enzymatic antioxidants reduced drastically while the accumulations of all three ROS and the response of enzymatic antioxidants were significantly higher than those at 45°C. These results suggest that the cells utilize several stress acclimatization mechanisms to cope up the heat stress. There was a dramatic difference in the physiological changes and cellular antioxidant mechanism upon heat stress at 45 and 50°C. The cellular defense response of A. dimorphus gets impaired after heat stress at 50°C but remains active at 45°C, exhibiting the heat resistance and, thus, the thermotolerance.


Assuntos
Microalgas , Antioxidantes , Clorofila A , Temperatura Alta , Estresse Oxidativo , Espécies Reativas de Oxigênio , Estresse Fisiológico , Temperatura
10.
Chemphyschem ; 19(21): 2872-2878, 2018 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-30133086

RESUMO

This work reports the application possibilities of cobalt ferrite (CoFe2 O4 ) magnetic nanoparticles (CFMNPs) for stimuli responsive drug delivery by magnetic field induced hyperthermia technique. The CFMNPs were characterized by X-ray diffraction (XRD) with Rietveld analysis, field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), fourier transform infrared spectroscopy (FTIR), thermogravimetry and differential thermal analysis (TG-DTA), vibrating sample magnetometer (VSM) and superconducting quantum interference device (SQUID) magnetometry. Particles were functionalized with folic acid (FA) by EDC-NHS coupling method and loaded with anticancer drug (DOX) by activated folate ions. The drug release was studied as a function of time at two different temperatures (37 and 44 °C) under pH∼5.5 and 7. It was observed that the drug release rate is higher at elevated temperature (44 °C) and acidic pH∼5.5 as compared to our normal body temperature and pH∼7 using the CFMNPs. This way, we have developed a pH and temperature sensitive drug delivery system, which can release the anticancer drug selectively by applying ac magnetic field as under ac field particles are heated up. We have calculated the amount of heat generation by the particles around 1.67 °C per second at ∼600 Hz frequency. By MTT assay on cancer cell and normal cell, it was confirmed that CFMNPs are nontoxic and biocompatible in nature, which assures that our synthesized particles can be successfully used in localized cancer treatment by stimuli responsive drug delivery technique.


Assuntos
Antineoplásicos/farmacologia , Cobalto/química , Doxorrubicina/farmacologia , Compostos Férricos/química , Nanopartículas de Magnetita/química , Temperatura , Adulto , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Doxorrubicina/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Relação Estrutura-Atividade , Propriedades de Superfície , Células Tumorais Cultivadas
11.
J Phys Chem A ; 122(25): 5563-5573, 2018 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-29878781

RESUMO

Intermolecular proton transfer (IMPT) in a C-H···O hydrogen bonded dimer of an α,ß-unsaturated aldehyde, methacrolein (MC), upon nonresonant multiphoton ionization by 532 nm laser pulses (10 ns), has been investigated using time-of-flight (TOF) mass spectrometry under supersonic cooling condition. The mass peaks corresponding to both the protonated molecular ion [(MC)H+] and intact dimer cation [(MC)2]•+ show up in the mass spectra, and the peak intensity of the former increases proportionately with the latter with betterment of the jet cooling conditions. The observations indicate that [(MC)2]•+ is the likely precursor of (MC)H+ and, on the basis of electronic structure calculations, IMPT in the dimer cation has been shown to be the key reaction for formation of the latter. Laser power dependences of ion yields indicate that at this wavelength the dimer is photoionized by means of 4-photon absorption process, and the total 4-photon energy is nearly the same as the predicted vertical ionization energy of the dimer. Electronic structure calculations reveal that the optimized structures of [(MC)2]•+ correspond to a proton transferred configuration wherein the aldehydic hydrogen is completely shifted to the carbonyl oxygen of the neighboring moiety. Potential energy scans along the C-H···O coordinate also show that the IMPT in [(MC)2]•+ is a barrierless process.

12.
J Chem Phys ; 146(8): 084310, 2017 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-28249428

RESUMO

In this paper, we report finding of a remarkable chemical effect of hydrogen bonding, elimination of hydrogen fluoride (HF) from the hydrogen bonded dimers of 2-fluorophenol (2-FP) and 3-fluorophenol (3-FP), in a supersonic jet expansion upon multi-photon ionization using 4th harmonic wavelength (266 nm) of a Q-switched Nd:YAG laser, and the reaction has been probed by time-of-flight mass spectrometry. No HF elimination is observed to occur by such means from the monomer of 3-FP, but it occurs with a small yield from the monomer of 2-FP. On the other hand, upon dimerization the reaction is triggered on for 3-FP, and for 2-FP it becomes so facile that no intact dimer cation survives and only the HF eliminated product ion appears in the mass spectra. Electronic structure calculation shows that in the cationic ground (D0) state, although the reaction for 2-FP dimer is exothermic, the associated barrier is significantly high (2.75 eV) and for its occurrence, absorption of three photons (2+1 type) is required. However, the reaction is predicted barrierless in the intermediate S1 state of this dimer, and HF loss dimer cation mass peak could appear in the mass spectrum due to an effective two-photon (1+1) ionization process. In the case of 3-FP dimer, the energy barriers both in S1 (neutral) and D0 (ionic) states are high, and it is suggested that for occurrence of HF elimination, dimer cation needs to absorb an additional photon. For facilitation of HF loss from this dimer cation, a rearrangement of the geometry and formation of an intermediate adduct have been suggested, and it is argued that the latter could be produced by nucleophilic attack of the neutral moiety at the ortho site of the cationic counterpart.

14.
J Chem Phys ; 141(4): 044303, 2014 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-25084906

RESUMO

Time-of-flight mass spectra of cyclopentanone and its clusters cooled in a supersonic jet expansion have been measured following 4-, 3-, and 2-photon ionizations by the 2nd, 3rd, and 4th harmonic wavelengths, respectively, of a Q-switched Nd:YAG laser. The mass spectra reveal signatures of energetically favored keto to enol tautomerization of the molecular ion leading to intermolecular proton transfer, and this observation is found sharply dependent on the ionization wavelengths used. Electronic structure calculation predicts that in spite of the energetic preference, keto-enol conversion barrier of isolated molecular ion is high. However, the barrier is significantly reduced in a CH⋯O hydrogen-bonded dimer of the molecule. The transition states associated with tautomeric conversion of both cyclopentanone monomer and dimer cations have been identified by means of intrinsic reaction co-ordinate calculation. In a supersonic jet expansion, although a weakly bound dimer is readily generated, the corresponding cation and also the protonated counterpart are observed only for ionization by 532 nm. For other two ionization wavelengths, these species do not register in the mass spectra, where the competing reaction channels via α-cleavage of the ring become dominant. In contrast to the report of a recent study, we notice that the intact molecular ion largely survives fragmentations when ionized from the 2-photon resonant 3p Rydberg state as intermediate using nanosecond laser pulses, and the corresponding resonant 3-photon ionization spectrum has been recorded probing the intact molecular ion.


Assuntos
Ciclopentanos/química , Ciclopentanos/efeitos da radiação , Íons/química , Íons/efeitos da radiação , Luz , Prótons , Dimerização , Ligação de Hidrogênio , Lasers , Espectrometria de Massas , Modelos Químicos , Processos Fotoquímicos , Teoria Quântica
15.
Vaccine ; 42(21): 126153, 2024 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-39060204

RESUMO

Vaccines and host genetic factors can influence the SARS-CoV-2 evolution and emergence of new variants. Even vaccinated cases get affected as virus continues to evolve, raising concerns about vaccine efficacy and the emergence of immune escape variants. Here, we have analyzed 2295 whole-genome sequences of SARS-CoV-2 collected from vaccinated and unvaccinated cases to evaluate the impact of vaccines on virus diversity within hosts. Our comparative analysis revealed a significant higher incidence of intra-host single nucleotides variants (iSNVs) in vaccinated cases compared to unvaccinated ones (p value<0.0001). Furthermore, we have found that specific mutational processes, including APOBEC (C > T) mediated and ADAR1 (A > G) mediated mutations, were found more prevalent in vaccinated cases. Vaccinated cases exhibited higher accumulation of nonsynonymous mutation than unvaccinated cases. Fixed iSNVs were predominantly located in the ORF1ab and spike genes, several key omicron defining immune escape variants S477N, Q493R, Q498R, Y505H, L452R, and N501Y were identified in the RBD domain of spike gene in vaccinated cases. Our findings suggest that vaccine plays an important role in the evolution of the virus genome. The virus genome acquires random mutations due to error-prone replication of the virus, host modification through APOBEC and ADAR1 mediated editing mechanism, and oxidative stress. These mutations become fixed in the viral population due to the selective pressure imposed by vaccination.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Evolução Molecular , Evasão da Resposta Imune , Mutação , SARS-CoV-2 , Vacinação , Humanos , SARS-CoV-2/imunologia , SARS-CoV-2/genética , COVID-19/prevenção & controle , COVID-19/imunologia , COVID-19/virologia , Evasão da Resposta Imune/genética , Vacinas contra COVID-19/imunologia , Genoma Viral , Sequenciamento Completo do Genoma , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/imunologia , Adenosina Desaminase/genética , Adenosina Desaminase/imunologia
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 313: 124143, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38471309

RESUMO

A sensitive and selective relay-based scheme for the detection of salicylaldehyde, Hg2+, and folic acid (FA) has been demonstrated using fluorescent ovalbumin functionalized gold nanoclusters (OVA-AuNCs, λem = 655 nm) in this article. The OVA-AuNCs were conjugated to salicylaldehyde via an imine linkage to form Salic_OVA-AuNCs conjugate. The molecular docking study reveals that multiple functional groups and amino acid residues are involved in the interaction between salicylaldehyde and the OVA-AuNCs. The coupling of salicylaldehyde with OVA-AuNCs results in fluorescence quenching at 655 nm and concomitant formation of an emission band at 500 nm, which have leveraged to detect salicylaldehyde down to 2.02 µM. Following that, the Salic_OVA-AuNCs has been used for the detection of Hg2+ and FA. Several processes, such as internal charge transfer (ICT), photoinduced electron transfer (PET) and metallophilic interactions, are involved between the Salic_OVA-AuNCs nanoprobe and the analytes, which allowed to detect Hg2+ and FA down to 0.13 nM and 0.11 nM, respectively. The Salic_OVA-AuNCs nanoprobe has an additional naked-eye utility when applied to paper-strip sensing strategy for Hg2+ and FA detection.


Assuntos
Aldeídos , Mercúrio , Nanopartículas Metálicas , Ovalbumina , Ouro/química , Ácido Fólico , Simulação de Acoplamento Molecular , Nanopartículas Metálicas/química , Espectrometria de Fluorescência/métodos , Mercúrio/química , Corantes Fluorescentes/química
17.
Cureus ; 16(7): e65725, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39211674

RESUMO

A promising method for non-invasive cancer diagnosis and prognosis is through salivary biomarkers. By utilizing the distinct characteristics of saliva and the progress made in biomarker studies, these markers provide more accurate diagnoses for a wider range of malignancies. An attempt was made to thoroughly investigate the field of salivary biomarkers for tumor prognosis and diagnosis, with an emphasis on their use in various cancer forms. Predetermined search criteria were utilized for a systematic search across numerous databases for peer-reviewed papers from 2009 to 2021. Studies concentrating on the detection, validation, and clinical use of salivary biomarkers for different types of cancers were included in the inclusion criteria. Initially, 238 articles were found, of which 15 relevant articles satisfied the inclusion requirements. Information on study aims, methodology, findings, and conclusions were gathered for data extraction. We identified recurrent themes, patterns, and contradictions by a thematic analysis. We also assessed state-of-the-art salivary biomarkers for tumor diagnosis and prognosis. One major finding is the identification of biomolecules in saliva linked to several cancer forms, including pancreatic, oral, breast, lung, and stomach cancers. There is an increasing amount of evidence demonstrating the value of saliva-based diagnostics in oncology. This is due to new detection methods and developments in salivary proteomics and genomics. Identification of exosomes and microvesicles as salivary biomarker profiles offered molecular understandings of the etiology and evolution of cancer, thereby opening new avenues for diagnosis and treatment. Salivary biomarkers are a non-invasive approach for the early detection and prediction of cancer, thanks to the unique properties of saliva and advancements in biomarker research. This potential revolution could enhance patient outcomes and reduce cancer-related deaths.

18.
Indian J Otolaryngol Head Neck Surg ; 76(1): 1335-1340, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38440520

RESUMO

Collision tumours, characterized by the simultaneous occurrence of two distinct neoplasms within the same anatomical site, are exceedingly rare in oral pathology. This case report presents an uncommon collision tumour involving desmoplastic ameloblastoma and squamous odontogenic tumour in the anterior maxilla of a 52-year-old male from the Indian population. Desmoplastic ameloblastoma is a variant of ameloblastoma known for its unique histopathological features, while squamous odontogenic tumour is a benign epithelial odontogenic tumour with distinctive clinical behaviour. The rarity of this occurrence emphasizes the need for accurate diagnosis and effective treatment strategies. This report discusses the clinical presentation, radiographic findings, and histopathological characteristics of this collision tumour. Through the presentation of this case, we aim to contribute to the understanding of these rare entities and their management considerations.

19.
Autophagy ; 20(3): 697-698, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37953605

RESUMO

Mycobacterium tuberculosis (Mtb) employs a multifaceted arsenal to elude host defense mechanisms, including those associated with autophagy and lysosome function. Within the realm of host-pathogen interactions, NCOR1, a well-recognized transcriptional co-repressor, is known to associate with a multitude of protein complexes to effect the repression of a diverse spectrum of genes. However, its role in regulating macroautophagy/autophagy, lysosome biogenesis, and, by extension, Mtb pathogenesis remains unexplored. The depletion of NCOR1 assumes a pivotal role in the control of the AMPK-MTOR-TFEB signaling axis, thereby fine-tuning cellular ATP homeostasis. This finely orchestrated adjustment further alters the profile of proteins involved in autophagy and lysosomal biogenesis through its master regulator, TFEB, culminating in the increased Mtb survival within the host milieu. Furthermore, the treatment of NCOR1-depleted cells with either rapamycin, antimycin A, or metformin demonstrates a capacity to restore the TFEB activity and LC3-II levels, consequently restoring the capacity of host cells to clear Mtb. Additionally, exogenous NCOR1 expression rescues the AMPK-MTOR-TFEB signaling axis and essentially the autophagic induction machinery. Overall, these findings demonstrate a crucial role of NCOR1 in regulating Mtb pathogenesis within myeloid cells and sheds light toward its involvement in the development of novel host-directed therapies.


Assuntos
Mycobacterium tuberculosis , Mycobacterium tuberculosis/metabolismo , Autofagia/genética , Proteínas Quinases Ativadas por AMP/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fatores de Transcrição/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Lisossomos/metabolismo
20.
Talanta ; 275: 126089, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38608343

RESUMO

Water, although an important part of everyday life, is acts as one of the most significant contaminants in various applications such as biomedical monitoring, chemical production, petroleum-based fuel and food processing. In fact, the presence of water in other solvents is a huge concern. For the quantification of trace water content, different methods such as Karl-Fischer, electrochemical, nuclear magnetic resonance, chromatography, and thermogravimetric analysis have been used. Although every technique has its own benefit, each one suffers from several drawbacks that include high detection costs, lengthy procedures and specialized operations. Nowadays, the development of fluorescence-based chemical probes has become an exciting area of research for the quick and accurate estimation of water content in organic solvents. A variety of chemical processes such as hydrolysis reaction, metal ions promoted oxidation reaction, suppression of the -C═N isomerization, protonation and deprotonation reactions, and molecular aggregation have been well researched in the last few years for the fluorescent detection of trace water. These chemical processes eventually lead to different photophysical events such as aggregation-induced emission (AIE), aggregation-induced emission enhancement (AIEE), aggregation-caused quenching (ACQ), fluorescent resonance energy transfer (FRET), charge transfer, photo-induced electron transfer (PET), excited state intramolecular proton transfer (ESIPT) that are responsible for the detection. This review presents a summary of the fluorescence-based chemosensors reported in recent years. The design of water sensors, sensing mechanisms and their potential applications are reviewed and discussed.

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