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1.
Proc Natl Acad Sci U S A ; 121(11): e2318599121, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38446856

RESUMO

T cells help orchestrate immune responses to pathogens, and their aberrant regulation can trigger autoimmunity. Recent studies highlight that a threshold number of T cells (a quorum) must be activated in a tissue to mount a functional immune response. These collective effects allow the T cell repertoire to respond to pathogens while suppressing autoimmunity due to circulating autoreactive T cells. Our computational studies show that increasing numbers of pathogenic peptides targeted by T cells during persistent or severe viral infections increase the probability of activating T cells that are weakly reactive to self-antigens (molecular mimicry). These T cells are easily re-activated by the self-antigens and contribute to exceeding the quorum threshold required to mount autoimmune responses. Rare peptides that activate many T cells are sampled more readily during severe/persistent infections than in acute infections, which amplifies these effects. Experiments in mice to test predictions from these mechanistic insights are suggested.


Assuntos
Doenças Autoimunes , Infecção Persistente , Animais , Camundongos , Tolerância Periférica , Linfócitos T , Autoantígenos , Peptídeos
2.
Mol Oncol ; 18(4): 988-1011, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38414326

RESUMO

Inhibitors specifically targeting the 1-phosphatidylinositol 3-phosphate 5-kinase (PIKFYVE) disrupt lysosome homeostasis, thereby selectively terminating autophagy-dependent human cancer cells in vivo as well as in vitro without harming the viability of nonmalignant cells. To elucidate the mechanism by which PIKFYVE inhibition induces cell death, autophagy-dependent melanoma cells were compared with normal foreskin fibroblasts. RNA sequence profiling suggested that PIKFYVE inhibitors upregulated an endoplasmic reticulum (ER) stress response involving interleukin-24 (IL24; also known as MDA7) selectively in melanoma cells. Subsequent biochemical and genetic analyses confirmed these results and extended them to tumor xenografts in which tumor formation and expansion were inhibited. IL24 expression was upregulated by the DDIT3/CHOP/CEBPz transcription factor, a component of the PERK-dependent ER-stress response. Ectopic expression of IL24-induced cell death in melanoma cells, but not in foreskin fibroblasts, whereas ablation of the IL24 gene in melanoma cells prevented death. IL24 upregulation was triggered specifically by PIKFYVE inhibition. Thus, unlike thapsigargin and tunicamycin, which induce ER-stress indiscriminately, PIKFYVE inhibitors selectively terminated PIKFYVE-sensitive melanoma by inducing IL24-dependent ER-stress. Moreover, induction of cell death by a PIKFYVE inhibitor together with ectopic expression of IL24 protein was cumulative, thereby confirming the therapeutic potential of PIKFYVE inhibitors in the treatment of melanoma.


Assuntos
Melanoma , Humanos , Melanoma/tratamento farmacológico , Melanoma/genética , Melanoma/patologia , Morte Celular , Interleucinas/genética , Autofagia/fisiologia , Estresse do Retículo Endoplasmático , Apoptose/fisiologia , Fosfatidilinositol 3-Quinases
3.
J Biomol Struct Dyn ; 42(6): 3233-3248, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37203884

RESUMO

Melanoma,also known as a 'black tumor', begins in the melanocytes when cells (that produce pigment) grows out of control. Immunological dysregulation, which raises the risk for multiple illnesses, including melanoma, may be influenced by stress tiggered through viral infection, long term effects of ultraviolet radiation, environmental pollutants etc. Borapetoside C is one of the phytoconstituents from Tinospora crispa, and its biological source has been reported for its antistress property. Network pharmacology and KEGG pathway analysis of borapetoside C-regulated proteins were conducted to identify the hub genes involved in melanoma development. Further, a molecular docking was performed between borapetoside C and targets involved in melanoma. Further, the top 3 complexes were selected based on the binding energy to conduct molecular dynamics simulations to evaluate the stability of ligand-protein complex followed by principal component analysis and dynamic cross-correlation matrix. In addition, borapetoside C was also screened for its pharmacokinetics and toxicity profile. Network Pharmacology studies and KEGG pathway analysis revealed 8 targets involved in melanoma. Molecular docking between borapetoside C and targets involved in melanoma identified 3 complexes with minimum binding i.e. borapetoside C- MAP2K1, MMP9, and EGFR. Further, molecular dynamics simulations showed a stable complex of borapetoside C with MMP9 and EGFR. The present study suggested that borapetoside C may target MMP9 and EGFR to possess an anti-melanoma property. This finding can be useful in developing a novel therapeutic agent against melanoma from a natural source.Communicated by Ramaswamy H. Sarma.


Assuntos
Diterpenos , Melanoma , Humanos , Melanoma/tratamento farmacológico , Metaloproteinase 9 da Matriz , Simulação de Acoplamento Molecular , Raios Ultravioleta , Receptores ErbB
4.
Appl Opt ; 62(12): 3160-3168, 2023 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-37133164

RESUMO

Recognizing that wavelength modulation spectroscopy (WMS) is particularly important in the development of high-sensitivity gas sensing systems, this paper presents a detailed analysis of the R 1f /Δ I 1 WMS technique that has recently been successfully demonstrated for calibration-free measurements of the parameters that support detecting multiple gases under challenging conditions. In this approach, the magnitude of the 1f WMS signal (R 1f ) was normalized by using the laser's linear intensity modulation (Δ I 1) to obtain the quantity R 1f /Δ I 1 that is shown to be unaffected by large variations in R 1f itself due to the variations in the intensity of the received light. In this paper, different simulations have been used to explain the approach taken and the advantages that it shows. A 40 mW, 1531.52 nm near-infrared distributed feedback (DFB) semiconductor laser was used to extract the mole fraction of acetylene in a single-pass configuration. The work has shown a detection sensitivity of 0.32 ppm for 28 cm (0.089 ppm-m) with an optimum integration time of 58 s. The detection limit achieved has been shown to be better than the value of 1.53 ppm (0.428 ppm-m) for R 2f WMS by a factor of 4.7, which is a significant improvement.

5.
Proc Natl Acad Sci U S A ; 120(20): e2221726120, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37155885

RESUMO

From proteins to chromosomes, polymers fold into specific conformations that control their biological function. Polymer folding has long been studied with equilibrium thermodynamics, yet intracellular organization and regulation involve energy-consuming, active processes. Signatures of activity have been measured in the context of chromatin motion, which shows spatial correlations and enhanced subdiffusion only in the presence of adenosine triphosphate. Moreover, chromatin motion varies with genomic coordinate, pointing toward a heterogeneous pattern of active processes along the sequence. How do such patterns of activity affect the conformation of a polymer such as chromatin? We address this question by combining analytical theory and simulations to study a polymer subjected to sequence-dependent correlated active forces. Our analysis shows that a local increase in activity (larger active forces) can cause the polymer backbone to bend and expand, while less active segments straighten out and condense. Our simulations further predict that modest activity differences can drive compartmentalization of the polymer consistent with the patterns observed in chromosome conformation capture experiments. Moreover, segments of the polymer that show correlated active (sub)diffusion attract each other through effective long-ranged harmonic interactions, whereas anticorrelations lead to effective repulsions. Thus, our theory offers nonequilibrium mechanisms for forming genomic compartments, which cannot be distinguished from affinity-based folding using structural data alone. As a first step toward exploring whether active mechanisms contribute to shaping genome conformations, we discuss a data-driven approach.


Assuntos
Cromatina , Polímeros , Polímeros/química , Cromatina/genética , Cromossomos/metabolismo , Genoma , Genômica
6.
Autophagy ; 19(9): 2464-2484, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36803256

RESUMO

Although PIKFYVE phosphoinositide kinase inhibitors can selectively eliminate PIKFYVE-dependent human cancer cells in vitro and in vivo, the basis for this selectivity has remained elusive. Here we show that the sensitivity of cells to the PIKFYVE inhibitor WX8 is not linked to PIKFYVE expression, macroautophagic/autophagic flux, the BRAFV600E mutation, or ambiguous inhibitor specificity. PIKFYVE dependence results from a deficiency in the PIP5K1C phosphoinositide kinase, an enzyme required for conversion of phosphatidylinositol-4-phosphate (PtdIns4P) into phosphatidylinositol-4,5-bisphosphate (PtdIns[4,5]P2/PIP2), a phosphoinositide associated with lysosome homeostasis, endosome trafficking, and autophagy. PtdIns(4,5)P2 is produced via two independent pathways. One requires PIP5K1C; the other requires PIKFYVE and PIP4K2C to convert PtdIns3P into PtdIns(4,5)P2. In PIKFYVE-dependent cells, low concentrations of WX8 specifically inhibit PIKFYVE in situ, thereby increasing the level of its substrate PtdIns3P while suppressing PtdIns(4,5)P2 synthesis and inhibiting lysosome function and cell proliferation. At higher concentrations, WX8 inhibits both PIKFYVE and PIP4K2C in situ, which amplifies these effects to further disrupt autophagy and induce cell death. WX8 did not alter PtdIns4P levels. Consequently, inhibition of PIP5K1C in WX8-resistant cells transformed them into sensitive cells, and overexpression of PIP5K1C in WX8-sensitive cells increased their resistance to WX8. This discovery suggests that PIKFYVE-dependent cancers could be identified clinically by low levels of PIP5K1C and treated with PIKFYVE inhibitors.Abbreviations: DMSO: dimethylsulfoxide; ELISA: enzyme-linked immunosorbent assay; LC3-I: microtubule associated protein light chain 3-I; LC3-II: microtubule associated protein light chain 3-II; MS: mass spectrometry; PtdIns: phosphatidylinositol; PtdIns3P: PtdIns-3-phosphate; PtdIns4P: PtdIns-4-phosphate; PtdIns5P: PtdIns-5-phosphate; PtdIns(3,5)P2: PtdIns-3,5-bisphosphate; PtdIns(4,5)P2/PIP2: PtdIns-4,5-bisphosphate; PtdIns(3,4,5)P3/PIP3: PtdIns-3,4,5-trisphosphate; PIKFYVE: phosphoinositide kinase, FYVE-type zinc finger containing; PIK3C3: phosphatidylinositol 3-kinase catalytic subunit type 3; PI4KA: phosphatidylinositol 4-kinase alpha; PI4KB: phosphatidylinositol 4-kinase beta; PI4K2A: phosphatidylinositol 4-kinase type 2 alpha; PI4K2B: phosphatidylinositol 4-kinase type 2 beta; PIP4K2A: phosphatidylinositol-5-phosphate 4-kinase type 2 alpha; PIP4K2B: phosphatidylinositol-5-phosphate 4-kinase type 2 beta; PIP4K2C: phosphatidylinositol-5-phosphate 4-kinase type 2 gamma; PIP5K1A: phosphatidylinositol-4-phosphate 5-kinase type 1 alpha; PIP5K1B: phosphatidylinositol-4-phosphate 5-kinase type 1 beta; PIP5K1C: phosphatidylinositol-4-phosphate 5-kinase type 1 gamma; WX8: 1H-indole-3-carbaldehyde (4-anilino-6-[4-morpholinyl]-1,3,5-triazin-2-yl)hydrazone.


Assuntos
1-Fosfatidilinositol 4-Quinase , Neoplasias , Humanos , Autofagia/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Fosfatidilinositóis , Proteínas Associadas aos Microtúbulos , Fosfotransferases (Aceptor do Grupo Álcool)
7.
Natl Med J India ; 36(3): 150-156, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38692608

RESUMO

Background Injecting drug use (IDU) is associated with several cardiometabolic risks. We aimed to measure the independent effects of IDU behaviour and related factors on serum lipid profile among people who inject drugs (PWIDs). Methods We did a longitudinal study with six follow-up measurements at an interval of 2 months among 104 PWIDs from 11 selected hotspots under two blocks in West Bengal, India. Generalized estimating equations with robust standard errors analysed the effect of addiction habits on lipid profile parameters. Results The mean (SD) age of the participants was 27.6 (5.24) years, 36.5% married and 44.3% were unemployed at the time of recruitment. At the baseline, the mean (SD) body mass index (BMI) and fasting blood sugar (FBS) were 20.0 (1.82) kg/m2 and 112.0 (15.90) mg/dl, respectively. The mean duration of drug use was 2.5 (1.20) years. While 62.5% had normal triglyceride (TG), 14.4% had high total cholesterol (TC) and 69.2% had dyslipidaemia at the baseline. Adjusted for age, BMI, FBS and other addiction-related variables, models showed that longer duration of drug use (>3 years) resulted in higher levels of TG, higher TC-to-high-density lipoprotein ratio and dyslipidaemia. Tobacco use and high FBS level were also risk factors for dyslipidaemia. Conclusions Higher duration of IDU, tobacco use and higher FBS were associated with deranged lipid profile among PWIDs.


Assuntos
Lipídeos , População Rural , Abuso de Substâncias por Via Intravenosa , Humanos , Índia/epidemiologia , Adulto , Masculino , Feminino , Abuso de Substâncias por Via Intravenosa/epidemiologia , Abuso de Substâncias por Via Intravenosa/sangue , Estudos Longitudinais , Lipídeos/sangue , População Rural/estatística & dados numéricos , Adulto Jovem , Comportamento Aditivo/epidemiologia , Comportamento Aditivo/sangue , Dislipidemias/epidemiologia , Dislipidemias/sangue
8.
Indian J Public Health ; 66(3): 307-312, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36149110

RESUMO

Background: The Rashtriya Bal Swasthya Karyakram (RBSK) was launched in 2013 to screen and manage birth defects, deficiencies, diseases, and developmental delays including disabilities in Indian children, with the help of designated mobile health teams and grassroot workers across the country. Objectives: Performance of the RBSK program in three selected blocks of a health district of a large Indian state (West Bengal) was assessed. Methods: The performance assessment was based on input, process, and output performances, using checklists based on RBSK operational guidelines. Results: While some essential evaluation tools were available in required numbers at the block level, many were unavailable. There were deficiencies in the number of health staff appointed. Although most screening camps were conducted as per microplan, some were not. Anthropometric measurements were not done in some camps; Information, Education, and Communication (IEC) materials were not used adequately. Issues with fund management were also noted. The intervention rate at higher centers (District Early Intervention Centre) was low with regard to the children referred for management. Involvement of grassroot workers such as ASHA was also found to be lacking. Conclusion: Frequent orientation training of medical officers and staff is needed along with the efforts to strengthen the referral system and the patient tracking system. Sensitizing the children and their guardians regarding the importance of the relevant health issues is also needed with the help of the proper implementation of IEC services.


Assuntos
Atenção à Saúde , Intervenção Educacional Precoce , Criança , Humanos , Índia , Programas de Rastreamento , Encaminhamento e Consulta
9.
Stem Cell Reports ; 17(2): 397-412, 2022 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-35063131

RESUMO

Inhibition of PIKfyve phosphoinositide kinase selectively kills autophagy-dependent cancer cells by disrupting lysosome homeostasis. Here, we show that PIKfyve inhibitors can also selectively eliminate pluripotent embryonal carcinoma cells (ECCs), embryonic stem cells, and induced pluripotent stem cells under conditions where differentiated cells remain viable. PIKfyve inhibitors prevented lysosome fission, induced autophagosome accumulation, and reduced cell proliferation in both pluripotent and differentiated cells, but they induced death only in pluripotent cells. The ability of PIKfyve inhibitors to distinguish between pluripotent and differentiated cells was confirmed with xenografts derived from ECCs. Pretreatment of ECCs with the PIKfyve specific inhibitor WX8 suppressed their ability to form teratocarcinomas in mice, and intraperitoneal injections of WX8 into mice harboring teratocarcinoma xenografts selectively eliminated pluripotent cells. Differentiated cells continued to proliferate, but at a reduced rate. These results provide a proof of principle that PIKfyve specific inhibitors can selectively eliminate pluripotent stem cells in vivo as well as in vitro.


Assuntos
Apoptose/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Fosfatidilinositol 3-Quinases/química , Animais , Autofagia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , DNA/metabolismo , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Inibidores Enzimáticos/uso terapêutico , Feminino , Fase G1 , Humanos , Hidrazinas/química , Hidrazinas/farmacologia , Hidrazinas/uso terapêutico , Camundongos , Camundongos Nus , Fosfatidilinositol 3-Quinases/metabolismo , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Células-Tronco Pluripotentes/metabolismo , Teratocarcinoma/tratamento farmacológico , Teratocarcinoma/patologia , Transplante Heterólogo
10.
Indian J Occup Environ Med ; 26(4): 240-244, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-37033747

RESUMO

Background: Adverse short-term and long-term health effects following a high level of noise have been established. The current study aims to find the relationship of these effects with an environment-specific level of noise exposure. Materials and Methods: A comparative cross-sectional study was conducted among 50 auto-rickshaw drivers and 51 age-matched service-sector employees. The peak average noise exposure in decibels (dB) was measured. The duration of exposure and response regarding perceptions following noise exposure was assessed through a pre-designed pre-tested semi-structured questionnaire. Results: The mean age of the participants was 42.24 (±13.72) years. Among the auto-rickshaw drivers, 82% perceived stress, 64% had hearing difficulty, and 74% complained of lack of sleep following exposure to a high level of noise. However, the perceptions were comparable among the comparison group and the differences were not statistically significant. The mean average peak level of noise exposure among drivers and their comparison group was 91.64 (±7.37) dB and 91.98 (± 8.06) dB, respectively, but were not different statistically. Around 52.94% of the service-sector respondents and 48% of the drivers were exposed to the lower cumulative noise levels. Those having a higher level of cumulative noise exposure, had a higher odds of feeling irritated (Odds ratio [OR]: 2.182, 95% confidence interval [CI]: 0.845-5.636), feeling stressed (OR: 5.805, 95% CI: 1.552-21.708), having palpitation (OR: 3.694, 95% CI: 1.264-10.793), and lack of sleep (OR: 3.020, 95% CI: 1.006-9.066). Conclusion: Stress and lack of sleep were the most important perceived effects of noise exposure. The exposures to the higher cumulative noise level in specified groups were more important in relation to quantifying perceived symptoms than the average peak noise level.

11.
Mol Cancer Res ; 19(8): 1361-1374, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34050002

RESUMO

Histone deacetylase inhibitors (HDACi) induce hyperacetylation of histones by blocking HDAC catalytic sites. Despite regulatory approvals in hematological malignancies, limited solid tumor clinical activity has constrained their potential, arguing for better understanding of mechanisms of action (MOA). Multiple activities of HDACis have been demonstrated, dependent on cell context, beyond the canonical induction of gene expression. Here, using a clinically relevant exposure duration, we established DNA damage as the dominant signature using the NCI-60 cell line database and then focused on the mechanism by which hyperacetylation induces DNA damage. We identified accumulation of DNA-RNA hybrids (R-loops) following romidepsin-induced histone hyperacetylation, with single-stranded DNA (ssDNA) breaks detected by single-cell electrophoresis. Our data suggest that transcription-coupled base excision repair (BER) is involved in resolving ssDNA breaks that, when overwhelmed, evolve to lethal dsDNA breaks. We show that inhibition of BER proteins such as PARP will increase dsDNA breaks in this context. These studies establish accumulation of R-loops as a consequence of romidepsin-mediated histone hyperacetylation. We believe that the insights provided will inform design of more effective combination therapy with HDACis for treatment of solid tumors. IMPLICATIONS: Key HDAC inhibitor mechanisms of action remain unknown; we identify accumulation of DNA-RNA hybrids (R-loops) due to chromatin hyperacetylation that provokes single-stranded DNA damage as a first step toward cell death.


Assuntos
DNA de Cadeia Simples/efeitos dos fármacos , Depsipeptídeos/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/metabolismo , Estruturas R-Loop/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Linhagem Celular Tumoral , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Reparo do DNA/efeitos dos fármacos , Reparo do DNA/genética , DNA de Cadeia Simples/genética , Humanos , Células PC-3 , Estruturas R-Loop/genética
13.
Materials (Basel) ; 14(8)2021 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-33924057

RESUMO

In this work, we continued our systematic investigations on synthesis, structural studies, and electrochemical behavior of Ni-rich materials Li[NixCoyMnz]O2 (x + y + z = 1; x ≥ 0.8) for advanced lithium-ion batteries (LIBs). We focused, herein, on LiNi0.85Co0.10Mn0.05O2 (NCM85) and demonstrated that doping this material with high-charge cation Mo6+ (1 at. %, by a minor nickel substitution) results in substantially stable cycling performance, increased rate capability, lowering of the voltage hysteresis, and impedance in Li-cells with EC-EMC/LiPF6 solutions. Incorporation of Mo-dopant into the NCM85 structure was carried out by in-situ approach, upon the synthesis using ammonium molybdate as the precursor. From X-ray diffraction studies and based on our previous investigation of Mo-doped NCM523 and Ni-rich NCM811 materials, it was revealed that Mo6+ preferably substitutes Ni residing either in 3a or 3b sites. We correlated the improved behavior of the doped NCM85 electrode materials in Li-cells with a partial Mo segregation at the surface and at the grain boundaries, a tendency established previously in our lab for the other members of the Li[NixCoyMnz]O2 family.

14.
Proc Natl Acad Sci U S A ; 118(5)2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33514660

RESUMO

An effective vaccine that can protect against HIV infection does not exist. A major reason why a vaccine is not available is the high mutability of the virus, which enables it to evolve mutations that can evade human immune responses. This challenge is exacerbated by the ability of the virus to evolve compensatory mutations that can partially restore the fitness cost of immune-evading mutations. Based on the fitness landscapes of HIV proteins that account for the effects of coupled mutations, we designed a single long peptide immunogen comprising parts of the HIV proteome wherein mutations are likely to be deleterious regardless of the sequence of the rest of the viral protein. This immunogen was then stably expressed in adenovirus vectors that are currently in clinical development. Macaques immunized with these vaccine constructs exhibited T-cell responses that were comparable in magnitude to animals immunized with adenovirus vectors with whole HIV protein inserts. Moreover, the T-cell responses in immunized macaques strongly targeted regions contained in our immunogen. These results suggest that further studies aimed toward using our vaccine construct for HIV prophylaxis and cure are warranted.


Assuntos
Vacinas contra a AIDS/imunologia , Adenoviridae/metabolismo , Vetores Genéticos/metabolismo , HIV-1/imunologia , Proteoma/metabolismo , Sequência de Aminoácidos , Animais , Antígenos Virais/imunologia , Feminino , Infecções por HIV/imunologia , Imunização , Macaca mulatta , Masculino , Linfócitos T Citotóxicos/imunologia , Proteínas Virais/química , Proteínas Virais/metabolismo
15.
Science ; 368(6497): 1386-1392, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32554597

RESUMO

The nucleus contains diverse phase-separated condensates that compartmentalize and concentrate biomolecules with distinct physicochemical properties. Here, we investigated whether condensates concentrate small-molecule cancer therapeutics such that their pharmacodynamic properties are altered. We found that antineoplastic drugs become concentrated in specific protein condensates in vitro and that this occurs through physicochemical properties independent of the drug target. This behavior was also observed in tumor cells, where drug partitioning influenced drug activity. Altering the properties of the condensate was found to affect the concentration and activity of drugs. These results suggest that selective partitioning and concentration of small molecules within condensates contributes to drug pharmacodynamics and that further understanding of this phenomenon may facilitate advances in disease therapy.


Assuntos
Antineoplásicos/farmacologia , Núcleo Celular/metabolismo , Resistencia a Medicamentos Antineoplásicos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Antineoplásicos/uso terapêutico , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Homólogo 5 da Proteína Cromobox , Proteínas Cromossômicas não Histona/genética , Proteínas Cromossômicas não Histona/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Subunidade 1 do Complexo Mediador/genética , Subunidade 1 do Complexo Mediador/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Nucleofosmina , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
17.
Nat Commun ; 11(1): 377, 2020 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-31953427

RESUMO

Vaccination has essentially eradicated poliovirus. Yet, its mutation rate is higher than that of viruses like HIV, for which no effective vaccine exists. To investigate this, we infer a fitness model for the poliovirus viral protein 1 (vp1), which successfully predicts in vitro fitness measurements. This is achieved by first developing a probabilistic model for the prevalence of vp1 sequences that enables us to isolate and remove data that are subject to strong vaccine-derived biases. The intrinsic fitness constraints derived for vp1, a capsid protein subject to antibody responses, are compared with those of analogous HIV proteins. We find that vp1 evolution is subject to tighter constraints, limiting its ability to evade vaccine-induced immune responses. Our analysis also indicates that circulating poliovirus strains in unimmunized populations serve as a reservoir that can seed outbreaks in spatio-temporally localized sub-optimally immunized populations.


Assuntos
Proteínas do Capsídeo/genética , Aptidão Genética , Taxa de Mutação , Mutação , Poliomielite/epidemiologia , Poliomielite/virologia , Poliovirus/genética , Antígenos Virais/genética , Proteínas do Capsídeo/classificação , Biologia Computacional , Surtos de Doenças , Evolução Molecular , HIV/genética , Humanos , Modelos Genéticos , Filogenia , Poliomielite/imunologia , Poliovirus/imunologia , Prevalência , Probabilidade , Proteínas Virais/classificação , Proteínas Virais/genética , Vacinas Virais
18.
Indian J Otolaryngol Head Neck Surg ; 71(4): 542-549, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31750117

RESUMO

Maxillofacial trauma, a common injury in urban population following road traffic accident or act of interpersonal violence of which orbital floor fractures is common. It impairs the integrity of the extraocular muscles and may be accompanied by enophthalmos, orbital deformity and diplopia. Orbital reconstruction is essential to improve anatomical and visual deformity. Repair of orbital floor is done by autologous bone graft or synthetic implants. Compare outcome of orbital floor reconstruction in blow out orbital fracture using autogenous bone graft from iliac crest, outer table of mandible, alloplastic implant- silastic block and titanium mesh. 30 patients having orbital fractures were considered in study population. All the patients were treated by ORIF and repair of floor by subcilliary incision. Out of 30 patients, repair of orbital floor was done by autologous bone graft from iliac crest in 7 patients (Group A), bone graft from outer table of mandible in 5 patients (Group B), implant using silastic block in 8 patients (Group C) and titanium mesh in 10 patients (Group D). Factors analyzed were age, sex, cause of fracture and treatment outcome in terms of correction of pre operative diplopia and enophthalmos, rate of development of post operative infection, wound dehiscence and implant exposure. All patents were reviewed at 4 weeks and 12 weeks following operation. 71.42% of patients in Group A had early correction of diplopia and enophthalmos. This was 100% in rest of the groups. All patients had complete correction when assessed at 12 weeks post operatively. Post operative complication rate was 20% and 12.5% in Group B and C respectively. There were no complications in the rest of the groups within the follow up period. No statistically significant difference as to the chance of occurrence of complication could be found amongst the groups. Autologous bone graft has no immunological reaction but donor site morbidity. Silastic block may case immunological reaction, infection, poor drainage of orbital floor. But titanium mesh for orbital floor repair has excellent outcome and superior to other modality of treatment.

19.
Sci Signal ; 12(604)2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31641081

RESUMO

T cells require the protein tyrosine phosphatase CD45 to detect and respond to antigen because it activates the Src family kinase Lck, which phosphorylates the T cell antigen receptor (TCR) complex. CD45 activates Lck by opposing the negative regulatory kinase Csk. Paradoxically, CD45 has also been implicated in suppressing TCR signaling by dephosphorylating the same signaling motifs within the TCR complex upon which Lck acts. We sought to reconcile these observations using chemical and genetic perturbations of the Csk/CD45 regulatory axis incorporated with computational analyses. Specifically, we titrated the activities of Csk and CD45 and assessed their influence on Lck activation, TCR-associated ζ-chain phosphorylation, and more downstream signaling events. Acute inhibition of Csk revealed that CD45 suppressed ζ-chain phosphorylation and was necessary for a regulatable pool of active Lck, thereby interconnecting the activating and suppressive roles of CD45 that tune antigen discrimination. CD45 suppressed signaling events that were antigen independent or induced by low-affinity antigen but not those initiated by high-affinity antigen. Together, our findings reveal that CD45 acts as a signaling "gatekeeper," enabling graded signaling outputs while filtering weak or spurious signaling events.


Assuntos
Antígenos Comuns de Leucócito/imunologia , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Animais , Proteína Tirosina Quinase CSK/genética , Humanos , Células Jurkat , Antígenos Comuns de Leucócito/genética , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/genética , Proteína Tirosina Quinase p56(lck) Linfócito-Específica/imunologia , Camundongos , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/genética , Linfócitos T/citologia
20.
Indian J Public Health ; 63(3): 171-177, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31552844

RESUMO

BACKGROUND: Overweight among adolescents has high prevalence on the eastern part of India, especially West Bengal. OBJECTIVES: The current study was conducted to estimate and compare the effects of different dietary habits and habits related to physical activity in the development of overweight and obesity among rural schoolgoing adolescents. METHODS: A prospective repeated measures study was conducted on 645 schoolgoing adolescents from selected rural government-aided schools from June 2017 to December 2017. Dietary habits of the students and physical activity-related factors were the major predictors. Adjusting for the age and sex of the participants, effect of these factors on the development of overweight and obesity was analyzed by generalized estimating equations for 2 repeated measures, taken 6 months apart. RESULTS: Most of the respondents were aged ≥16 years (56.90%), female (52.87%), Hindu (76.74%), from a nuclear family (76.74%), and studying in the secondary level (57.68%). There was a stark rise in proportion of overweight from 0.93% to 7.44%. The prevalence of unhealthy dietary habits was 68.99% at the baseline, and 66.82% on follow-up. The overall prevalence of inadequate physical activity increased to 48.68% from 47.91%. Female gender and older age group were at higher risk of being overweight or obesity. Overall fast food showed highest risk (3.04, 95% confidence interval [CI]: 1.86-4.95), while among the boys, it was with less vegetable consumption (4.64, 95% CI: 1.84-11.69). CONCLUSIONS: Strong evidence was generated of dietary practices being more rigidly related to overweight among the adolescents. Healthy dietary practices coupled with physical activity should be promoted to mitigate the risk of obesity.


Assuntos
Dieta/estatística & dados numéricos , Exercício Físico , Sobrepeso/epidemiologia , População Rural/estatística & dados numéricos , Adolescente , Distribuição por Idade , Índice de Massa Corporal , Estudos Transversais , Feminino , Inquéritos Epidemiológicos , Humanos , Índia/epidemiologia , Masculino , Obesidade Infantil/epidemiologia , Estudos Prospectivos , Distribuição por Sexo , Fatores Socioeconômicos , Adulto Jovem
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