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1.
Anal Chem ; 96(37): 14749-14758, 2024 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-39215696

RESUMEN

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has triggered an ongoing global pandemic, necessitating rapid and accurate diagnostic tools to monitor emerging variants and preparedness for the next outbreak. This study introduces a multidisciplinary approach combining Fourier Transform Infrared (FTIR) microspectroscopy and Machine learning to comprehensively characterize and strain-type SARS-CoV-2 variants. FTIR analysis of pharyngeal swabs from different pandemic waves revealed distinct vibrational profiles, particularly in nucleic acid and protein vibrations. The spectral wavenumber range between 1150 and 1240 cm-1 was identified as the classification marker, distinguishing Healthy (noninfected) and infected samples. Machine learning algorithms, with neural networks exhibiting superior performance, successfully classified SARS-CoV-2 variants with a remarkable accuracy of 98.6%. Neural networks were also able to identify and differentiate a small cohort infected with influenza A variants, H1N1 and H3N2, from SARS-CoV-2-infected and Healthy samples. FTIR measurements further show distinct red shifts in vibrational energy and secondary structural alterations in the spike proteins of more transmissible forms of SARS-CoV-2 variants, providing experimental validation of the computational data. This integrated approach presents a promising avenue for rapid and reliable SARS-CoV-2 variant identification, enhancing our understanding of viral evolution and aiding in diagnostic advancements, particularly for an infectious disease with unknown etiology.


Asunto(s)
COVID-19 , SARS-CoV-2 , Espectroscopía Infrarroja por Transformada de Fourier/métodos , SARS-CoV-2/aislamiento & purificación , SARS-CoV-2/genética , SARS-CoV-2/química , Humanos , COVID-19/diagnóstico , COVID-19/virología , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H1N1 del Virus de la Influenza A/genética , Glicoproteína de la Espiga del Coronavirus/química , Aprendizaje Automático , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Subtipo H3N2 del Virus de la Influenza A/genética , Redes Neurales de la Computación
2.
Exp Cell Res ; 442(1): 114216, 2024 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-39182663

RESUMEN

The toxic effect of oxidized-heme, also known as hemin, is implicated in developing adverse clinical outcome in various hematolytic diseases. To simulate and reconstruct the molecular events associated with hemin exposure on circulating monocytes, we employed a THP-1 cell line based in vitro model. Flow cytometry and Western blot analyses were subsequently applied. Hemin-treated THP-1 produced ROS in a dose-dependent manner which resulted in 10-30 % of cell death primarily through apoptosis. Surviving cells induced autophagy which too was ROS-dependent, as revealed by application of N-acetyl-L-cysteine. Hemin-mediated autophagy promoted differentiation of CD14+ THP-1 cells into CD11b+ macrophages. Application of 3-methyladenine, reinforced that differentiation of THP-1 was an autophagy-dependent process. It was revealed that despite a higher polarization towards M2-macrophage, synthesis of pro-inflammatory cytokines namely TNF-α, IL-1A, IL-2, IL-8 and IL-17A predominated. IL-6, a pleiotropic cytokine, was also elevated. It may thus be surmised that hemin-induced pro-inflammatory response in THP-1 is downstream to ROS-dependent autophagy and monocyte differentiation. This finding is translationally meaningful as hemin is already approved by FDA for amelioration of acute porphyria and is actively considered as a therapeutic agent for other diseases. This study underscores the need of further research untangling the reciprocal regulation of inflammatory signaling and autophagy under oxidative stress.


Asunto(s)
Autofagia , Diferenciación Celular , Hemina , Macrófagos , Especies Reactivas de Oxígeno , Humanos , Especies Reactivas de Oxígeno/metabolismo , Autofagia/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Hemina/farmacología , Macrófagos/metabolismo , Macrófagos/efectos de los fármacos , Células THP-1 , Inflamación/metabolismo , Inflamación/patología , Citocinas/metabolismo , Monocitos/metabolismo , Monocitos/efectos de los fármacos , Apoptosis/efectos de los fármacos
3.
J Phys Chem Lett ; 15(7): 2075-2081, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38358315

RESUMEN

Aqueous glycine plays many different roles in living systems, from being a building block for proteins to being a neurotransmitter. To better understand its fundamental behavior, we study glycine's orientational behavior near model aqueous interfaces, in the absence and presence of electric fields and biorelevant ions. To this purpose, we use a surface-specific technique called heterodyne-detected vibrational sum-frequency generation spectroscopy (HD-VSFG). Using HD-VSFG, we directly probe the symmetric and antisymmetric stretching vibrations of the carboxylate group of zwitterionic glycine. From their relative amplitudes, we infer the zwitterion's orientation near surfactant-covered interfaces and find that it is governed by both electrostatic and surfactant-specific interactions. By introducing additional ions, we observe that the net orientation is altered by the enhanced ionic strength, indicating a change in the balance of the electrostatic and surfactant-specific interactions.

4.
J Phys Chem Lett ; 14(41): 9285-9290, 2023 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-37815274

RESUMEN

We study the effect of sodium chloride (NaCl) on the properties of the interface of water and the surfactant dodecyl sulfate (DS-) using heterodyne-detected vibrational sum-frequency generation spectroscopy. We find that the signal of the O-H stretch vibrations of oriented water molecules at the interface is highly nonlinearly dependent on the NaCl concentration. This nonlinear dependence is explained by a combination of screening of the electric field of surface-bound DS- ions pointing into the bulk and screening of the Coulomb repulsion between the headgroups of the DS- ions in the surface plane. The latter effect strongly increases the oriented water signal within a limited NaCl concentration range of 10-100 mM, indicating a two-dimensional hydrophobic collapse of the surfactant layer. The occurrence of collapse is supported by model calculations of the surface potential and surface surfactant density.

5.
J Cell Biochem ; 124(6): 849-860, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37158093

RESUMEN

The standard diagnosis of prostate cancer is accomplished by the identification of cytomorphological deviations in biopsied tissues while immunohistochemistry is used to resolve the equivocal cases. Accumulating evidence favors the concept that epithelial-to-mesenchymal transition (EMT) is a stochastic process composed of multiple intermediate states instead of a single binary switch. Despite its significant role in promoting cancer aggressiveness, the current tissue-based risk stratification tools do not include any of the EMT phenotypes as a metric. As a proof-of-concept, the present study analyzes the temporal progression of EMT in transforming growth factor-beta (TGF-ß) treated PC3 cells encompassing multifarious characteristics such as morphology, migration and invasion, gene expression, biochemical fingerprint, and metabolic activity. Our multimodal approach reinstates EMT plasticity in TGF-ß treated PC3 cells. Further, it highlights that mesenchymal transition is accompanied by discernible changes in cellular morphometry and molecular signatures particularly in the range of 1800-1600 cm-1 and 3100-2800 cm-1 of Fourier-transformed infrared (FTIR) spectra signifying Amide III and lipid, respectively. Investigation of attenuated total reflectance (ATR)-FTIR spectra of extracted lipids from PC3 cell populations undergoing EMT identifies changes in stretching vibration at FTIR peaks at 2852, 2870, 2920, 2931, 2954, and 3010 cm-1 characteristics of fatty acids and cholesterol. Chemometric analysis of these spectra indicates that the level of unsaturation and acyl chain length of fatty acid coregister with differential epithelial/mesenchymal states of TGF-ß treated PC3 cells. Observed changes in lipids also correlate with cellular nicotinamide adenine dinucleotide hydrogen (NADH) and flavin adenine dinucleotide dihydrogen (FADH2) levels and mitochondrial oxygen consumption rate. In summary, our study establishes that morphological and phenotypic traits of epithelial/mesenchymal variants of PC3 cells concur with their respective biochemical and metabolic properties. It also underscores that spectroscopic histopathology has a definitive potential to refine the diagnosis of prostate cancer reckoning its molecular and biochemical heterogeneities.


Asunto(s)
Neoplasias de la Próstata , Factor de Crecimiento Transformador beta , Humanos , Masculino , Factor de Crecimiento Transformador beta/metabolismo , Espectroscopía Infrarroja por Transformada de Fourier , Transición Epitelial-Mesenquimal , Neoplasias de la Próstata/metabolismo , Línea Celular Tumoral , Análisis Multivariante , Lípidos , Movimiento Celular
6.
J Phys Chem Lett ; 13(49): 11391-11397, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36455883

RESUMEN

Interfacial vibrational footprints of the binary mixture of sodium dodecyl sulfate (SDS) and hexaethylene glycol monododecyl ether (C12E6) were probed using heterodyne detected vibrational sum frequency generation (HDVSFG). Our results show that in the presence of C12E6 at CMC (70 µM) the effect of SDS on the orientation of interfacial water molecules is enhanced 10 times compared to just pure surfactants. The experimental results contest the traditional Langmuir adsorption model predictions. This is also evidenced by our molecular dynamics simulations that show a remarkable restructuring and enhanced orientation of the interfacial water molecules upon DS- adsorption to the C12E6 surface. The simulations show that the adsorption free energy of DS- ions to a water surface covered with C12E6 is an enthalpy-driven process and more attractive by ∼10 kBT compared to the adsorption energy of DS- to the surface of pure water.

7.
Artículo en Inglés | MEDLINE | ID: mdl-36517108

RESUMEN

INTRODUCTION: Renal involvement in type 2 diabetes mellitus (T2DM) may be due to diabetes (diabetic kidney disease (DKD)), causes other than diabetes (non-diabetic kidney disease (NDKD)) or overlap of DKD and NDKD (mixed kidney disease group). Prevalence of NDKD and predictive value of clinical or biochemical indicators have been explored in retrospective cohorts with preselection biases warranting the need for prospectively conducted unbiased renal biopsy study. RESEARCH DESIGN AND METHODS: Consecutive subjects aged >18 years with T2DM and renal involvement with estimated glomerular filtration rate of 30-60 mL/min/m2 and/or albumin:creatinine ratio of >300 mg/g were offered renal biopsy. Prevalence of DKD, NDKD and mixed kidney disease was documented. Clinical/laboratory parameters of subjects were recorded and compared between groups and were tested for ability to predict histopathological diagnosis. RESULTS: We screened 6247 subjects with T2DM of which 869 fulfilled inclusion criteria for biopsy. Of the 869 subjects, biopsy was feasible in 818 subjects. Out of 818, we recruited first 110 subjects who agreed to undergo renal biopsy. Among those 110 subjects, 73 (66.4%) had DKD; 20 (18.2 %) had NDKD; and 17 (15.4 %) had mixed kidney disease. Subjects with NDKD as compared with DKD had shorter duration of diabetes (p<0.001), absence of retinopathy (p<0.001) and absence of neuropathy (p<0.001). Logistic regression revealed that only presence of retinopathy and duration of diabetes were statistically significant to predict histopathological diagnosis of DKD. 30% of DKD did not have retinopathy, thereby limiting the utility of the same as a discriminator. Use of traditional indicators of biopsy would have indicated a need for renal biopsy in 87.2% of subjects, though 64.5% of the subjects had DKD, who would not have benefitted from biopsy. CONCLUSION: NDKD and mixed kidney disease in T2DM with renal involvement are very common and traditionally used parameters to select biopsies are of limited value in clinical decision making.


Asunto(s)
Diabetes Mellitus Tipo 2 , Nefropatías Diabéticas , Enfermedades de la Retina , Humanos , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiología , Prevalencia , Estudios Retrospectivos , Nefropatías Diabéticas/diagnóstico , Nefropatías Diabéticas/epidemiología , Nefropatías Diabéticas/etiología , Biopsia/efectos adversos , Enfermedades de la Retina/complicaciones
8.
J Phys Chem Lett ; 13(42): 9793-9800, 2022 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-36227233

RESUMEN

UiO-66 is a benchmark metal-organic framework that holds great promise for the design of new functional materials. In this work, we perform two-dimensional infrared measurements on polycrystalline membranes of UiO-66 grown on c-sapphire substrates. We study the symmetric and antisymmetric stretch vibrations of the carboxylate groups of the terephthalate linker ions and find that these vibrations show a rapid energy exchange and a collective vibrational relaxation with a time constant of 1.3 ps. We also find that the symmetric vibration of the carboxylate group is strongly coupled to a vibration of the aromatic ring of the terephthalate ion. We observe that the antisymmetric carboxylate vibrations of different terephthalate linkers show rapid resonant (Förster) energy transfer with a time constant of ∼1 ps.

9.
Cancer Gene Ther ; 29(11): 1697-1706, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35732909

RESUMEN

Development of endocrine resistance in hormone-receptor-positive (HR+ve) subtype and lack of definitive target in triple-negative subtype challenge breast cancer management. Contributing to such endocrine resistance is a protein called CUEDC2. It degrades hormone receptors, estrogen receptor-α (ERα) and progesterone receptor. Higher level of CUEDC2 in ERα+ve breast cancer corresponded to poorer disease prognosis. It additionally influences mitotic progression. However, the crosstalk of these two CUEDC2-driven functions in the outcome of breast cancer remained elusive. We showed that CUEDC2 degrades ERα during mitosis, utilising the mitotic-ubiquitination-machinery. We elucidated the importance of mitosis-specific phosphorylation of CUEDC2 in this process. Furthermore, upregulated CUEDC2 overrode mitotic arrest, increasing aneuploidy. Finally, recruiting a prospective cohort of breast cancer, we found significantly upregulated CUEDC2 in HR-ve cases. Moreover, individuals with higher CUEDC2 levels showed a poorer progression-free-survival. Together, our data confirmed that CUEDC2 up-regulation renders ERα+ve malignancies to behave essentially as HR-ve tumors with the prevalence of aneuploidy. This study finds CUEDC2 as a potential prognostic marker and a therapeutic target in the clinical management of breast cancer.


Asunto(s)
Neoplasias de la Mama , Receptor alfa de Estrógeno , Humanos , Femenino , Receptor alfa de Estrógeno/genética , Receptor alfa de Estrógeno/metabolismo , Neoplasias de la Mama/patología , Estudios Prospectivos , Mitosis/genética , Aneuploidia , Regulación Neoplásica de la Expresión Génica , Proteínas Adaptadoras Transductoras de Señales/metabolismo
11.
Sci Rep ; 12(1): 3539, 2022 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-35241725

RESUMEN

Microfluidics has emerged rapidly over the past 20 years and has been investigated for a variety of applications from life sciences to environmental monitoring. Although continuous-flow microfluidics is ubiquitous, segmented-flow or droplet microfluidics offers several attractive features. Droplets can be independently manipulated and analyzed with very high throughput. Typically, microfluidics is carried out within planar networks of microchannels, namely, microfluidic chips. We propose that fibers offer an interesting alternative format with key advantages for enhanced optical coupling. Herein, we demonstrate the generation of monodisperse droplets within a uniaxial optofluidic Lab-in-a-Fiber scheme. We combine droplet microfluidics with laser-induced fluorescence (LIF) detection achieved through the development of an optical side-coupling fiber, which we term a periscope fiber. This arrangement provides stable and compact alignment. Laser-induced fluorescence offers high sensitivity and low detection limits with a rapid response time making it an attractive detection method for in situ real-time measurements. We use the well-established fluorophore, fluorescein, to characterize the Lab-in-a-Fiber device and determine the generation of [Formula: see text] 0.9 nL droplets. We present characterization data of a range of fluorescein concentrations, establishing a limit of detection (LOD) of 10 nM fluorescein. Finally, we show that the device operates within a realistic and relevant fluorescence regime by detecting reverse-transcription loop-mediated isothermal amplification (RT-LAMP) products in the context of COVID-19 diagnostics. The device represents a step towards the development of a point-of-care droplet digital RT-LAMP platform.


Asunto(s)
Dispositivos Laboratorio en un Chip , Virus/aislamiento & purificación , Fluorescencia , Rayos Láser
12.
J Colloid Interface Sci ; 608(Pt 2): 2169-2180, 2022 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-34798383

RESUMEN

Specific interactions of yttrium and lanthanum ions with a fatty acid Langmuir monolayer were investigated using vibrational sum frequency spectroscopy. The trivalent ions were shown to interact with the charged form of the carboxylic acid group from nanomolar concentrations (<300 nM). Analysis of the spectral features from both the symmetric and the asymmetric carboxylate modes reveals the presence of at least three distinct coordination structures linked to specific binding configurations. Although the same species were identified for both La3+ and Y3+, they display a different concentration dependence, highlighting the ion-specificity of the interaction. From the analysis of the response of interfacial water molecules, the reversal of the surface charge, as well as the formation of yttrium hydroxide complexes, were detected upon increasing the amount of salt in solution. The binding interaction and kinetics of absorption are sensitive to the solution pH, showing a distinct ion speciation in the interfacial region when compared to the bulk. Changing the subphase pH or adding a monovalent background electrolyte that promotes deprotonation of the carboxylic acid headgroup could further improve the detection limit of La3+ and Y3+ to concentrations < 100 nM. These findings demonstrate that nM concentrations of trace metals contaminants, typically found on monovalent salts, can significantly influence the binding structure and kinetics in Langmuir monolayers.


Asunto(s)
Ácidos Carboxílicos , Agua , Iones , Límite de Detección , Vibración
13.
Infect Genet Evol ; 93: 104929, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34022438

RESUMEN

The polymorphic nature of merozoite surface protein 1(MSP1) raises doubts whether it may serve as a vaccine target against Plasmodium vivax malaria. This study analyses the impact of genetic variability on the epitope organization of different Pvmsp1 blocks. Ten blood samples collected from P. vivax infected malaria patients from West Bengal, India were used to analyze sequence and antigenic diversities of block 2 region of Pvmsp1. An additional 48 block 2 sequences from other countries were also analyzed. Global genetic framework of Pvmsp1 block 2 was represented by 12 indel clusters & 33 haplotypes (haplotype diversiy = 0.965 ± 0.024). Parasite sequences pertaining to other Pvmsp1 modules, namely block 6 and 10 displayed 14 & 29 (haplotype diversiy = 0.975 ± 0.003) and 22 & 30 indel clusters and haplotypes (haplotype diversiy = 0.947 ± 0.004), respectively. In spite of this remarkable genetic diversity, a small number of conserved epitopes were detected in all three PvMSP1 blocks. This novel finding substantiates that MSP1 could serve as a promising vaccine candidate against vivax malaria.


Asunto(s)
Epítopos de Linfocito B/inmunología , Variación Genética/inmunología , Vacunas contra la Malaria/inmunología , Proteína 1 de Superficie de Merozoito/inmunología , Plasmodium vivax/inmunología , Plasmodium vivax/genética
14.
Biochem Genet ; 59(3): 781-798, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33543406

RESUMEN

Increasing burden of non-communicable diseases like diabetes and cardiovascular disorders has made the global health scenario more challenging. Dyslipidemia in diabetes is a compounding risk factor for cardiovascular diseases, but there is dearth of identifying appropriate signatures to address this issue. The protein, adiponectin, is actively involved in regulating glucose levels as well as fatty acid breakdown playing crucial role in dyslipidemia and vascular complications. To identify the underlying genetic and molecular profile of adiponectin metabolic pathway in diabetic dyslipidemia and to correlate it with known biochemical and oxidative stress parameters of T2DM, we performed a case-control study in a total 264 individuals belonging to three categories such as diabetes with dyslipidemia (n = 88), diabetes without dyslipidemia (n = 86) and normal healthy controls (n = 90). Expression of adiponectin (ADIPOQ) and its receptors (ADIPOR1 and ADIPOR2) were measured in visceral and subcutaneous adipose tissues. A significant downregulated expression of ADIPOQ and its receptors in adipose tissues and PBMCs were linked with diabetic dyslipidemic condition. A multiple linear regression followed by MDR analysis implicated the elevated plasma malondialdehyde and decreased adiponectin level to be correlated with diabetic dyslipidemia. More interestingly, two single nucleotide polymorphisms of ADIPOQ (rs2241766 and rs1501299) were genetically associated with the risk of developing dyslipidemia. Other important biochemical factors found to be increased in diabetic dyslipidemic conditions included plasma C-reactive protein and 4-hydroxynonenal adducts. Our results explore, a complex interplay of genetic and biochemical parameters in diabetic dyslipidemia which is significant from the perspective of risk stratification and novel therapeutic strategy development.


Asunto(s)
Adiponectina/genética , Diabetes Mellitus Tipo 2/genética , Dislipidemias/metabolismo , Peroxidación de Lípido , Polimorfismo de Nucleótido Simple , Adulto , Alelos , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/complicaciones , Dislipidemias/complicaciones , Dislipidemias/genética , Femenino , Genotipo , Haplotipos , Humanos , Masculino , Persona de Mediana Edad
15.
Pathogens ; 10(1)2020 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-33374748

RESUMEN

SARS-CoV-2, a novel coronavirus, was first identified in Wuhan, China in December 2019. The rapid spread of the virus worldwide prompted the World Health Organization (WHO) to declare COVID-19 a pandemic in March 2020. COVID-19 discontinuing's a global health crisis. Approximately 80% of the patients infected with SARS-CoV-2 display undetectable to mild inflammation confined in the upper respiratory tract. In remaining patients, the disease turns into a severe form affecting almost all major organs predominantly due to an imbalance of innate and adaptive arms of host immunity. The purpose of the present review is to narrate the virus's invasion through the system and the host's reaction. A thorough discussion on disease severity is also presented regarding the behavior of the host's immune system, which gives rise to the cytokine storm particularly in elderly patients and those with comorbidities. A multifaceted yet concise description of molecular aspects of disease progression and its repercussion on biochemical and immunological features in infected patients is tabulated. The summary of pathological, clinical, immunological, and molecular accounts discussed in this review is of theranostic importance to clinicians for early diagnosis of COVID-19 and its management.

16.
Malar J ; 19(1): 367, 2020 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-33054833

RESUMEN

BACKGROUND: Reticulocyte binding protein-like homologs (RHs) are currently being evaluated as anti-erythrocytic stage vaccine targets against Plasmodium falciparum malaria. Present study explores the possible evolutionary drivers shaping the genetic organization of Pfrhs in Indian parasite population. It simultaneously evaluates a putative gain-of-function variant of PfRH5, a keystone member of PfRH family. METHODS: Receptor binding regions of Pfrh1, Pfrh2a/b, Pfrh4 and whole Pfrh5 were amplified using blood samples of P. falciparum malaria patients from Chhattisgarh and West Bengal and sequenced. Assembled sequences were analysed using MEGA7 and DnaSPv6. Binding affinities of recombinant PfRH5 proteins with basigin (BSG) were compared using in silico (CHARMM and AUTODOCK) and in vitro (Circular dichroism, fluorescence spectroscopy and isothermal titration calorimetry) methods. RESULTS: Pfrh1 (0.5), Pfrh2a/b (0.875), Pfrh4 (0.667) and Pfrh5 (0.778) sequence changes corresponded to low frequency (< 0.05) variants which resulted in an overall negative Tajima's D. Since mismatch distribution of none of the Pfrh loci corroborated with the model of demographic expansion, a possible role of natural selection formulating Pfrh sequence diversity was investigated. Among the 5 members, Pfrh5 displayed very high dN/dS (5.7) ratio. Nevertheless, the model of selective sweep due to presence of any advantageous substitutions could not be invoked as polymorphic nonsynonymous sites (17/18) for Pfrh5 exceeded significantly over the divergent (62/86) ones (p = 0.0436). The majority of extant PfRH5 sequences (52/83) differed from the reference Pf3D7 allele by a single amino acid mismatch (C203Y). This non-conservative alteration was predicted to lower the total interaction energy of that PfRH5variant with BSG, compared to PfRH53D7. Biophysical evidences validated the proposition that PfRH5variant formed a more stable complex with BSG. Thermodynamic association constant for interaction of BSG with PfRH5variant was also found to be higher (Kavariant = 3.63E6 ± 2.02E6 M-1 and Ka3D7 = 1.31E6 ± 1.21E6 M-1). CONCLUSIONS: Together, the study indicates that the genetic architecture of Pfrhs is principally shaped by purifying selection. The most abundant and ubiquitous PfRH5 variant harbouring 203Y, exhibits a greater affinity for BSG compared to PfRH53D7 possessing 203C allele. The study underscores the importance of selecting the functional allele that best represents circulating strains in natural parasite populations as vaccine targets.


Asunto(s)
Evolución Molecular , Variación Genética , Plasmodium falciparum/genética , Proteínas Protozoarias/química , Selección Genética , India , Ligandos
17.
Infect Genet Evol ; 85: 104418, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32561295

RESUMEN

The pathological outcome of malaria due to Plasmodium falciparum infection depends largely on erythrocyte invasion by blood-stage merozoites which employ a cascade of interactions occurring between parasite ligands and RBC receptors. In a previous study exploring the genetic diversity of region-II of PfEBA-175, a ligand that plays a crucial part in parasite's RBC entry through Glycophorin A (GPA) receptor, we demonstrated that F2 domain of region-II underwent positive selection in Indian P. falciparum population through the accumulation of non-synonymous polymorphisms. Here, we examine the functional impact of two highly prevalent non-synonymous alterations in F2, namely Q584E & E592A, using a battery of molecular, biophysical and in-silico techniques. Application of circular dichroism, FTIR, fluorescence spectroscopy reveals that secondary and three-dimensional folding of recombinant-F2 protein carrying 584E and 592A residues (F2-Mut) differs significantly from that carrying 584Q and 592E (F2-3D7). A comparison of spectroscopic and thermodynamic parameters shows that F2-Mut is capable of forming a complex with GPA with higher efficiency compared to F2-3D7. In silico docking predicts both artemisinin and artesunate possess the capacity of slipping into the GPA binding crevices of PfEBA-175 and disrupt PfEBA-GPA association. However, the estimated affinity of artesunate towards PfEBA-175 with 584E and 592A residues is higher than that of artemisinin. Thermodynamic parameters computed using isotherms are concordant with this in-silico prediction. Together, our data suggest that the presence of amino acid alterations in F2 provide structural and functional stability favoring PfEBA-GPA interaction and artesunate can efficiently disrupt the interaction between GPA and PfEBA-175 even carrying altered amino acid residues. The present study alerts the malaria research community by presenting evidence that the parasite is gaining evolutionary fitness by cultivating genetic alterations in many of its proteins.


Asunto(s)
Artemisininas/química , Artesunato/química , Glicoforinas/química , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/genética , Plasmodium falciparum/genética , Polimorfismo Genético , Proteínas Protozoarias/química , Proteínas Protozoarias/genética , Sustitución de Aminoácidos , Animales , Antimaláricos/química , Eritrocitos/parasitología , Interacciones Huésped-Parásitos , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Malaria Falciparum/parasitología , Simulación del Acoplamiento Molecular , Plasmodium falciparum/química , Unión Proteica , Dominios Proteicos , Pliegue de Proteína , Proteínas Protozoarias/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
18.
Carcinogenesis ; 41(12): 1767-1780, 2020 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-32386317

RESUMEN

Previously, our laboratory demonstrated that a deregulated E2F5/p38/SMAD3 axis was associated with uncontrolled cellular proliferation in prostate cancer (PCa). Here, we investigate the role of E2F5 in PCa in further details. RNAi-mediated E2F5 knockdown and pathway-focused gene expression profiling in PC3 cells identified TFPI2 as a downstream target of E2F5. Manipulation of E2F5 expression was also found to alter MMP-2 and MMP-9 levels as detected by Proteome Profiler array, western blot and reverse transcription coupled quantitative polymerase chain reaction Site-directed mutagenesis, dual-luciferase assays and chromatin immunoprecipitation with anti-E2F5-IgG coupled with qPCR confirmed recruitment of E2F5 on TFPI2, MMP-2 and MMP-9 promoters. RNAi-mediated knockdown of E2F5 expression in PC3 caused a significant alteration of cell migration while that of TFFI2 resulted in a modest change. Abrogation of E2F5 and TFPI2 expression was associated with significant changes in the gelatinolytic activity of active forms of MMP-2 and MMP-9. Moreover, E2F5, MMP-2 and MMP-9 levels were elevated in biopsies of PCa patients relative to that of benign hyperplasia, while TFPI2 expression was reduced. MMP-9 was coimmunoprecipitated with anti-TFPI2-IgG in PCa tissue samples suggesting a direct interaction between the proteins. Finally, artemisinin treatment in PC3 cells repressed E2F5 along with MMP-2/MMP-9 while triggering TFPI2 expression which alleviated PC3 aggressiveness possibly through inhibition of MMP activities. Together, our study reinstates an oncogenic role of E2F5 which operates as a dual-function transcription factor for its targets TFPI2, MMP-2 and MMP-9 and promotes cellular invasiveness. This study also indicates a therapeutic potential of artemisinin, a natural compound which acts by correcting dysfunctional E2F5/TFPI2/MMP axis in PCa.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Factor de Transcripción E2F5/metabolismo , Regulación Neoplásica de la Expresión Génica , Glicoproteínas/metabolismo , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Neoplasias de la Próstata/patología , Apoptosis , Biomarcadores de Tumor/genética , Movimiento Celular , Proliferación Celular , Factor de Transcripción E2F5/genética , Glicoproteínas/genética , Humanos , Masculino , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/genética , Invasividad Neoplásica , Pronóstico , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/metabolismo , Células Tumorales Cultivadas
19.
Nat Commun ; 11(1): 493, 2020 01 24.
Artículo en Inglés | MEDLINE | ID: mdl-31980619

RESUMEN

Despite the importance of the hydrogen ion in a wide range of biological, chemical, and physical processes, its molecular structure in solution remains lively debated. Progress has been primarily hampered by the extreme diffuse nature of the vibrational signatures of hydrated protons in bulk solution. Using the inherently surface-specific vibrational sum frequency spectroscopy technique, we show that at selected negatively charged interfaces, a resolved spectral feature directly linked to the H3O+ core in an Eigen-like species can be readily identified in a biologically compatible pH range. Centered at ~2540 cm-1, the band is seen to shift to ~1875 cm-1 when forming D3O+ upon isotopic substitution. The results offer the possibility of tracking and understanding from a molecular perspective the behavior of hydrated protons at charged interfaces.

20.
Gene ; 730: 144264, 2020 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-31759982

RESUMEN

Deregulated epithelial-to-mesenchymal transition constitutes one of the major aspects of cancer progression. In this study, to identify key molecular principles of EMT pathway in prostate carcinogenesis, an elaborate gene expression profiling was conducted by qRT-PCR and Western blot analyses. A preponderance of mesenchymal trait was observed in the pathological samples of prostate cancer. To simulate an appropriate in vitro model, PC3 cell line was subjected to hypoxic stress, which resulted in elevated expression of vimentin along with EMT-mediating transcription factors Zeb1 and Slug. To conciliate this mesenchymal behavior of PC3 cells, hsa-miR-200c was deliberately overexpressed which led to a marked reduction of cell motility and expression of vimentin, N-cadherin, Zeb1 and Slug with concurrent increase in level of ß-catenin. hsa-miR-200c was demonstrated to appease hypoxia-aggravated changes in cellular morphology by coordinated repression of vimentin, Zeb1 and Slug. Mode of action for hsa-miR-200c was mediated through transcriptional repression of Zeb1 and Slug interacting with E-box sequences in the vimentin promoter as documented by promoter assay. This ability of hsa-miR-200c to reclaim epithelial traits leads to the anticipation that molecular reprogramming of Zeb1-Slug/vimentin axis may relieve aggressiveness of prostate cancer.


Asunto(s)
Transición Epitelial-Mesenquimal/genética , MicroARNs/metabolismo , Neoplasias de la Próstata/genética , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Masculino , MicroARNs/genética , Células PC-3 , Factores de Transcripción de la Familia Snail/genética , Transcriptoma/genética , Vimentina/genética , Vimentina/metabolismo , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/genética
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