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Skeletal muscle wasting is a clinically proven pathology associated with Japanese encephalitis virus (JEV) infection; however, underlying factors that govern skeletal muscle damage are yet to be explored. The current study aims to investigate the pathobiology of skeletal muscle damage using a mouse model of JEV infection. Our study reveals a significant increment in viral copy number in skeletal muscle post-JEV infection, which is associated with enhanced skeletal muscle cell death. Molecular and biochemical analysis confirms NOX2-dependent generation of reactive oxygen species, leading to autophagy flux inhibition and cell apoptosis. Along with this, an alteration in mitochondrial dynamics (change in fusion and fission process) and a decrease in the total number of mitochondria copies were found during JEV disease progression. The study represents the initial evidence of skeletal muscle damage caused by JEV and provides insights into potential avenues for therapeutic advancement.
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Silicon in its nanoscale range offers a versatile scope in biomedical, photovoltaic, and solar cell applications. Due to its compatibility in integration with complex molecules owing to changes in charge density of as-fabricated Silicon Nanostructures (SiNSs) to realize label-free and real-time detection of certain biological and chemical species with certain biomolecules, it can be exploited as an indicator for ultra-sensitive and cost-effective biosensing applications in disease diagnosis. The morphological changes of SiNSs modified receptors (PNA, DNA, etc) have huge future scope in optimized sensitivity (due to conductance variations of SiNSs) of target biomolecules in health care applications. Further, due to the unique optical and electrical properties of SiNSs realized using the chemical etching technique, they can be used as an indicator for photovoltaic and solar cell applications. In this work, emphasis is given on different critical parameters that control the fabrication morphologies of SiNSs using metal-assisted chemical etching technique (MACE) and its corresponding fabrication mechanisms focusing on numerous applications in energy storage and health care domains. The evolution of MACE as a low-cost, easy process control, reproducibility, and convenient fabrication mechanism makes it a highly reliable-process friendly technique employed in photovoltaic, energy storage, and biomedical fields. Analysis of the experimental fabrication to obtain high aspect ratio SiNSs was carried out using iMAGEJ software to understand the role of surface-to-volume ratio in effective bacterial interfacing. Also, the role of silicon nanomaterials has been discussed as effective anti-bacterial surfaces due to the presence of silver investigated in the post-fabrication energy dispersive x-ray spectroscopy analysis using MACE.
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Nanoestruturas , Silício , Silício/química , Nanoestruturas/química , Técnicas Biossensoriais/métodos , Energia Solar , Humanos , Nanotecnologia/métodos , Nanotecnologia/economiaRESUMO
T-cell acute lymphoblastic leukemia (T-ALL) is a heterogeneous group of hematological tumors composed of distinct subtypes that vary in their genetic abnormalities, gene expression signatures, and prognoses. However, it remains unclear whether T-ALL subtypes differ at the functional level, and, as such, T-ALL treatments are uniformly applied across subtypes, leading to variable responses between patients. Here we reveal the existence of a subtype-specific epigenetic vulnerability in T-ALL by which a particular subgroup of T-ALL characterized by expression of the oncogenic transcription factor TAL1 is uniquely sensitive to variations in the dosage and activity of the histone 3 Lys27 (H3K27) demethylase UTX/KDM6A. Specifically, we identify UTX as a coactivator of TAL1 and show that it acts as a major regulator of the TAL1 leukemic gene expression program. Furthermore, we demonstrate that UTX, previously described as a tumor suppressor in T-ALL, is in fact a pro-oncogenic cofactor essential for leukemia maintenance in TAL1-positive (but not TAL1-negative) T-ALL. Exploiting this subtype-specific epigenetic vulnerability, we propose a novel therapeutic approach based on UTX inhibition through in vivo administration of an H3K27 demethylase inhibitor that efficiently kills TAL1-positive primary human leukemia. These findings provide the first opportunity to develop personalized epigenetic therapy for T-ALL patients.
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Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Epigênese Genética , Regulação Neoplásica da Expressão Gênica/genética , Terapia Genética , Histona Desmetilases/genética , Proteínas Nucleares/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/terapia , Proteínas Proto-Oncogênicas/metabolismo , Linhagem Celular Tumoral , Técnicas de Silenciamento de Genes , Histona Desmetilases/metabolismo , Humanos , Proteínas Nucleares/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/fisiopatologia , Proteínas Proto-Oncogênicas/genética , Proteína 1 de Leucemia Linfocítica Aguda de Células TRESUMO
The transcriptional activator MyoD serves as a master controller of myogenesis. Often in partnership with Mef2 (myocyte enhancer factor 2), MyoD binds to the promoters of hundreds of muscle genes in proliferating myoblasts yet activates these targets only upon receiving cues that launch differentiation. What regulates this off/on switch of MyoD function has been incompletely understood, although it is known to reflect the action of chromatin modifiers. Here, we identify KAP1 (KRAB [Krüppel-like associated box]-associated protein 1)/TRIM28 (tripartite motif protein 28) as a key regulator of MyoD function. In myoblasts, KAP1 is present with MyoD and Mef2 at many muscle genes, where it acts as a scaffold to recruit not only coactivators such as p300 and LSD1 but also corepressors such as G9a and HDAC1 (histone deacetylase 1), with promoter silencing as the net outcome. Upon differentiation, MSK1-mediated phosphorylation of KAP1 releases the corepressors from the scaffold, unleashing transcriptional activation by MyoD/Mef2 and their positive cofactors. Thus, our results reveal KAP1 as a previously unappreciated interpreter of cell signaling, which modulates the ability of MyoD to drive myogenesis.
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Diferenciação Celular , Desenvolvimento Muscular/fisiologia , Músculo Esquelético/citologia , Proteína MyoD/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Repressoras/metabolismo , Animais , Linhagem Celular , Regulação da Expressão Gênica no Desenvolvimento , Fatores de Transcrição MEF2/metabolismo , Camundongos , Proteína MyoD/genética , Mioblastos/citologia , Proteínas Nucleares/genética , Fosforilação , Proteínas Repressoras/genética , Transdução de Sinais , Proteína 28 com Motivo TripartidoRESUMO
Human leukemic T cells show decreased surface CD5 (sCD5) and increased cytoplasmic CD5 (cCD5). When we examined their expressions in the Jurkat T cells, it showed increased sCD5 and decreased cCD5, which is in sharp contrast with the pattern of CD5 expression observed for human leukemic T cells. Furthermore, this opposite pattern was due to the absence of an exonal switch between E1A and E1B. This study suggests that Jurkat cell does not retain all characteristics of T-ALL cells; thus, we should carefully interpret the data obtained using Jurkat T cell as a model cell line of T-ALL.
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Leucemia-Linfoma de Células T do Adulto , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Linhagem Celular , Humanos , Células JurkatRESUMO
The CD6 molecule, a cell surface marker, is involved in immunological synapse formation between T cell and antigen-presenting cell and T lymphocyte activation for adequate immune response. Geriatric individuals fail to mount a satisfactory immunological response against pathogens thus, insights into the functionality of CD6 may provide information for competence building in elderly immune cells. However, limited information is available regarding the status of CD6 in geriatric individuals. In this study, various isoforms of CD6 were analysed in aged mononuclear cells (MNCs) and compared with young individuals. In geriatric individuals, protein and mRNA expressions of CD6 molecule/isoforms were found to be decreased compared to their young counterparts. Furthermore, geriatric MNCs failed to show any change in CD6 levels and its isoforms upon polyclonal activation compared to young MNCs, marked by reduced Ca++ release and IL-2 expression. We suggest an overall decrease in CD6 levels in geriatric MNCs and T cells with suboptimal T cell activation in aged individuals.
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Envelhecimento/metabolismo , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Imunossenescência , Leucócitos Mononucleares/metabolismo , Ativação Linfocitária , Linfócitos T/metabolismo , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/genética , Envelhecimento/imunologia , Antígenos CD/genética , Antígenos de Diferenciação de Linfócitos T/genética , Células Cultivadas , Feminino , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Linfócitos T/imunologiaRESUMO
Alternate splicing contributes extensively to cellular complexity by generating protein isoforms with divergent functions. However, the role of alternate isoforms in development remains poorly understood. Mef2 transcription factors are essential transducers of cell signaling that modulate differentiation of many cell types. Among Mef2 family members, Mef2D is unique, as it undergoes tissue-specific splicing to generate a muscle-specific isoform. Since the ubiquitously expressed (Mef2Dα1) and muscle-specific (Mef2Dα2) isoforms of Mef2D are both expressed in muscle, we examined the relative contribution of each Mef2D isoform to differentiation. Using both in vitro and in vivo models, we demonstrate that Mef2D isoforms act antagonistically to modulate differentiation. While chromatin immunoprecipitation (ChIP) sequencing analysis shows that the Mef2D isoforms bind an overlapping set of genes, only Mef2Dα2 activates late muscle transcription. Mechanistically, the differential ability of Mef2D isoforms to activate transcription depends on their susceptibility to phosphorylation by protein kinase A (PKA). Phosphorylation of Mef2Dα1 by PKA provokes its association with corepressors. Conversely, exon switching allows Mef2Dα2 to escape this inhibitory phosphorylation, permitting recruitment of Ash2L for transactivation of muscle genes. Thus, our results reveal a novel mechanism in which a tissue-specific alternate splicing event has evolved that permits a ubiquitously expressed transcription factor to escape inhibitory signaling for temporal regulation of gene expression.
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Processamento Alternativo , Diferenciação Celular/genética , Músculos/citologia , Músculos/metabolismo , Fatores de Regulação Miogênica/genética , Fatores de Regulação Miogênica/metabolismo , Animais , Imunoprecipitação da Cromatina , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Ligação a DNA/metabolismo , Éxons/genética , Regulação da Expressão Gênica/genética , Genoma/genética , Fatores de Transcrição MEF2 , Camundongos , Músculos/enzimologia , Mutação/genética , Fatores de Regulação Miogênica/química , Proteínas Nucleares/metabolismo , Especificidade de Órgãos/genética , Fosforilação/genética , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica/genéticaRESUMO
Contrast Induced Acute Kidney Injury (CI-AKI) is one of the most common causes of acute kidney injury in hospitalized patients. These days, contrast agents are widely being used in both cardiology and radiology procedures. Old age, history of diabetes, heart failure, proteinuria and low blood pressure are some important risk factors in the pathogenesis of CI-AKI. Apart from risk stratification and the use of low and iso-osmolar contrast agents, intravenous fluid hydration with crystalloids is the only recommended strategy for the prevention of CI-AKI. Agents like N-acetylcysteine (NAC), atrial natriuretic peptide, ascorbic acid, theophylline, and fenoldopam have failed to show any proven beneficial role in the prevention of CI-AKI. Though hemodialysis is still being perceived by many clinicians as the modality for contrast removal but prophylactic hemodialysis is now not recommended for the prevention of CI-AKI.
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Injúria Renal Aguda , Meios de Contraste , Acetilcisteína/uso terapêutico , Injúria Renal Aguda/induzido quimicamente , Meios de Contraste/efeitos adversos , Humanos , Diálise Renal , Fatores de RiscoRESUMO
Pre-mRNA splicing is a complex regulatory nexus modulated by various trans-factors and their posttranslational modifications to create a dynamic transcriptome through alternative splicing. Signal-induced phosphorylation and dephosphorylation of trans-factors are known to regulate alternative splicing. However, the role of other posttranslational modifications, such as deacetylation/acetylation, methylation, and ubiquitination, that could modulate alternative splicing in either a signal-dependent or -independent manner remain enigmatic. Here, we demonstrate that Scaffold/matrix-associated region-binding protein 1 (SMAR1) negatively regulates alternative splicing through histone deacetylase 6 (HDAC6)-mediated deacetylation of RNA-binding protein Sam68 (Src-associated substrate during mitosis of 68 kDa). SMAR1 is enriched in nuclear splicing speckles and associates with the snRNAs that are involved in splice site recognition. ERK-MAPK pathway that regulates alternative splicing facilitates ERK-1/2-mediated phosphorylation of SMAR1 at threonines 345 and 360 and localizes SMAR1 to the cytoplasm, preventing its interaction with Sam68. We showed that endogenously, SMAR1 through HDAC6 maintains Sam68 in a deacetylated state. However, knockdown or ERK-mediated phosphorylation of SMAR1 releases the inhibitory SMAR1-HDAC6-Sam68 complex, facilitating Sam68 acetylation and alternative splicing. Furthermore, loss of heterozygosity at the Chr.16q24.3 locus in breast cancer cells, wherein the human homolog of SMAR1 (BANP) has been mapped, enhances Sam68 acetylation and CD44 variant exon inclusion. In addition, tail-vein injections in mice with human breast cancer MCF-7 cells depleted for SMAR1 showed increased CD44 variant exon inclusion and concomitant metastatic propensity, confirming the functional role of SMAR1 in regulation of alternative splicing. Thus, our results reveal the complex molecular mechanism underlying SMAR1-mediated signal-dependent and -independent regulation of alternative splicing via Sam68 deacetylation.
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Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Processamento Alternativo/fisiologia , Proteínas de Ciclo Celular/fisiologia , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/fisiologia , Histona Desacetilases/metabolismo , Matriz Nuclear/metabolismo , Proteínas Nucleares/fisiologia , Proteínas de Ligação a RNA/metabolismo , Acetilação , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Citoplasma/metabolismo , Proteínas de Ligação a DNA/genética , Técnicas de Silenciamento de Genes , Desacetilase 6 de Histona , Humanos , Receptores de Hialuronatos/genética , Sistema de Sinalização das MAP Quinases , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Transporte ProteicoRESUMO
OBJECTIVE: Neurotrauma has been labelled as a "silent epidemic" affecting both the developed and the developing nations. To date, no single brain-specific biomarker has been unanimously accepted for routine clinical use in TBI. Our study aims to determine the correlation of "cleaved-tau protein" in severe traumatic brain injury (TBI) with Glasgow Coma Scale (GCS) at the time of admission, mode of injury, CT findings and outcome at discharge. METHODS: The study has been approved by the institutional ethical committee. 40 cases with severe TBI and 40 randomly selected healthy controls were included in this prospective study. Venous blood samples were collected and serum cleaved tau protein levels were measured and correlated with gender, mode of injury, CT findings GCS score and GOS score at discharge. RESULTS: In the severe TBI group, the mean serum cleaved tau protein levels in males were 91.65 ± 41.34 pg/ml (mean ± S.D.), and females were 104.43 ± 53.08 pg/ml (mean ± S.D.), (p = 0.27). Mean serum C-tau level in study group was 95.48 ± 44.87 pg/ml (range 36.44-192.34), 95% C.I. (81.13-109.83) and in controls was 33.82 ± 13.65 pg/ml (range 2.48-66.54), 95% C.I. (29.46-38.19) (p < 0.001). The distribution of serum C-tau was in severe TBI group varied in all categories of GCS at 0th day (p < 0.001). Serum cleaved tau protein levels in the good outcome group were 74.26 ± 25.43 pg/ml (mean ± S.D.), range 36.44-144.54, 95% C.I. (63.52-85.00) and the poor-outcome group were 127.32 ± 49.40 pg/ml, range 66.65-192.34, 95% C.I. (100.99-153.64) (p = 0.001). CONCLUSION: In severe TBI, serum cleaved tau protein levels were significantly higher as compared to the controls in this prospective study. However, results of this study are preliminary in nature and there is a need to undertake larger prospective studies to reach a definitive conclusion.
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Lesões Encefálicas Traumáticas/diagnóstico , Proteínas tau/metabolismo , Adolescente , Adulto , Idoso , Biomarcadores/metabolismo , Lesões Encefálicas Traumáticas/sangue , Feminino , Escala de Coma de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Estudos Retrospectivos , Adulto JovemRESUMO
Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder characterised by various phenotypic features like hyperpigmented spots, neurofibromas, Lisch nodules, skeletal abnormalities and tendency to develop neoplasms. Only few cases of Non-Familial Spinal Neurofibromatosis-1 (Non-FSNF1) have been described in literature with tumors involving the spinal roots at every level being even rarer. We reported an interesting case of bilateral symmetrical cervical neurofibroma with multiple spinal neurofibromas appearing as mirror image on CT, associated with non familial NF-1 as a rare presentation in a 25-year-old adult male.
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OBJECTIVE: To evaluate the functional efficacy of an iridotomy in primary angle closure (PAC) eyes by measuring IOP responses to provocative tests before and after iridotomy. DESIGN: Prospective cohort study. SUBJECTS: 50 consecutive adult patients, 40-60 years of age, having primary angle closure. METHODS: Clinical examination, perimetry, biometry and ultrasound biomicroscopy of the angle were done. A darkroom prone provocative test (DRPPT), a mydriatic test and a Valsalva maneuver were performed before and after the iridotomy. MAIN OUTCOME MEASURES: IOP change in response to the provocative tests before and after iridotomy, and correlation with baseline parameters. RESULTS: IOP at baseline and after iridotomy was 14.4 ± 2.7 mmHg and 14.3 ± 2.6 mmHg, respectively (p = 0.)83. There was no significant change on diurnal phasing before and after an iridotomy (p = 0.)11. The mean IOP rise was 5.9 ± 3.7 mmHg on the DRPPT, 4.3 ± 3.5 mmHg on the Mydriatic test and 9.1 ± 4.9 mmHg on the Valsalva maneuver, and was reduced significantly to 3.2 ± 2.1 mmHg, 2.3 ± 1.8 and 6.4 ± 3.5, respectively(p < 0.001 for all tests). The decrease in pupillary block component for all 50 eyes was 46.5 % for the mydriatic test, 45.8 % for the DRPPT and 29.7 % for the Valsalva maneuver. PAC eyes positive on the DRPPT and mydriatic test prior to an iridotomy became negative after laser iridotomy in 75.9 and 84.6 % eyes, respectively, but on the Valsalva maneuver, only 23.8 % became negative. After iridotomy, eyes that continued to be positive on the mydriatic test had a significantly thicker lens (p = 0.02), decreased TCPD (p = 0.014) and narrower trabecular-iris angle (p = 0.048). On the DRPPT, they had a thicker lens (p = 0.03), shorter iris thickness (p = 0.025) and TCPD (p = 0.032), and on the Valsalva maneuver, they had a narrower scleral-ciliary process angle (SCPA; p = 0.019) and shorter TCPD (p = 0.015). CONCLUSIONS: This comprehensive functional evaluation of laser iridotomy in early PAC eyes showed a significant reduction in the pupillary block component of IOP response to provocative testing, possibly decreasing IOP fluctuations over time. An iridotomy does not, however, significantly change mean IOP or diurnal phasing of IOP in PAC eyes. Eyes with a very narrow angle or a thick lens may continue to have angle closure due to other pathomechanisms for angle closure.
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Glaucoma de Ângulo Fechado/cirurgia , Pressão Intraocular/fisiologia , Iridectomia , Iris/cirurgia , Adulto , Biometria , Estudos de Coortes , Feminino , Glaucoma de Ângulo Fechado/fisiopatologia , Gonioscopia , Humanos , Terapia a Laser , Lasers de Estado Sólido/uso terapêutico , Masculino , Microscopia Acústica , Pessoa de Meia-Idade , Estudos Prospectivos , Distúrbios Pupilares/fisiopatologia , Tonometria Ocular , Manobra de Valsalva/fisiologia , Testes de Campo VisualRESUMO
Chromatin remodeling is essential for controlling the expression of genes during development. The histone-modifying enzyme G9a/KMT1C can act both as a coactivator and a corepressor of transcription. Here, we show that the dual function of G9a as a coactivator vs. a corepressor entails its association within two distinct protein complexes, one containing the coactivator Mediator and one containing the corepressor Jarid1a/KDM5A. Functionally, G9a is important in stabilizing the Mediator complex for gene activation, whereas its repressive function entails a coordinate action with the histone H3 lysine 4 (H3K4) demethylase Jarid1a for the maintenance of gene repression. The essential nature of cross-talk between the histone methyltransferase G9a and the demethylase Jarid1a is demonstrated on the embryonic E(y)-globin gene, where the concurrent introduction of repressive histone marks (dimethylated H3K9 and dimethylated H3K27) and removal of activating histone mark (trimethylated H3K4) is required for maintenance of gene silencing. Taken together with our previous demonstration of cross-talk between UTX and MLL2 to mediate activation of the adult ß(maj)-globin gene, these data suggest a model where "active" and "repressive" cross-talk between histone-modifying enzymes coexist on the same multigene locus and play a crucial role in the precise control of developmentally regulated gene expression.
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Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Inativação Gênica/fisiologia , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Proteína 2 de Ligação ao Retinoblastoma/metabolismo , Animais , Proteínas de Ligação a DNA , Loci Gênicos/fisiologia , Globinas/biossíntese , Globinas/genética , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histona Metiltransferases , Histona-Lisina N-Metiltransferase/genética , Histonas/genética , Histona Desmetilases com o Domínio Jumonji , Complexo Mediador/genética , Complexo Mediador/metabolismo , Metilação , Camundongos , Camundongos Knockout , Proteína de Leucina Linfoide-Mieloide/genética , Proteína de Leucina Linfoide-Mieloide/metabolismo , Proteína 2 de Ligação ao Retinoblastoma/genéticaRESUMO
The demand for microfluidic pressure sensors is ever-increasing in various industries due to their crucial role in controlling fluid pressure within microchannels. While syringe pump setups have been traditionally used to regulate fluid pressure in microfluidic devices, they often result in larger setups that increase the cost of the device. To address this challenge and miniaturize the syringe pump setup, the researcher introduced integrated T-microcantilever-based microfluidic devices. In these devices, microcantilevers are incorporated, and their deflections correlate with the microchannel's pressure. When the relative pressure of fluid (plasma) changes, the T-microcantilever deflects, and the extent of this deflection provides information on fluid pressure within the microchannel. In this work, finite element method (FEM) based simulation was carried out to investigate the role of material, and geometric parameters of the cantilever, and the fluid viscosity on the pressure sensing capability of the T-microcantilever integrated microfluidic channel. The T-microcantilever achieves a maximum deflection of 127µm at a 5000µm/s velocity for Young's modulus(E) of 360 kPa of PDMS by employing a hinged structure. On the other hand, a minimum deflection of 4.05 × 10-5µm was attained at 5000µm/s for Young's modulus of 1 TPa for silicon. The maximum deflected angle of the T-cantilever is 20.46° for a 360 kPa Young's modulus while the minimum deflection angle of the T-cantilever is measured at 13.77° for 900 KPa at a fluid velocity of 5000µm s-1. The T-cantilever functions as a built-in microchannel that gauges the fluid pressure within the microchannel. The peak pressure, set at 8.86 Pa on the surface of the cantilever leads to a maximum deflection of 0.096µm (approximately 1µm) in the T-cantilever at a 1:1 velocity ratio. An optimized microfluidic device embedded with microchannels can optimize fluid pressure in a microchannel support cell separation.
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Microfluídica , Silício , Microfluídica/métodos , Silício/química , Módulo de ElasticidadeRESUMO
The function of CD5 protein in T cells is well documented, but regulation of its surface-level expression has yet to be fully understood. However, variation in its surface expression is associated with various immunopathological conditions and haematological malignancies. Briefly, expression of an alternate exon E1B of a human endogenous retroviruses (HERV) origin directly downregulates the conventional transcript variant (E1A), as its expression leads to the retention of the resultant protein at the intracellular level (cCD5). A separate promoter governs the expression of E1B and may be influenced by different transcription factors. Hence, we performed in silico transcription factor binding site (TFBS) analysis of the 3 kb upstream region from TSS of exon E1B and found five putative DREs (Dioxin Response elements) with good similarity scores. Further, we observed the upregulation in E1B expression after the exposure of BaP (a dioxin) and the reduction of E1A expression and their respective protein, i.e. sCD5 and cCD5. The binding of AHR at the predicted DRE sites was confirmed by ChIP qPCR and AHR specific inhibitor and gene silencing studies suggested the involvement of AHR in exonal switch. This study indicates that the polycyclic aromatic hydrocarbon decreases the sCD5 expression by upregulating alternative exon expression, which may adversely affect the overall T cell functions.
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Benzo(a)pireno , Antígenos CD5 , Éxons , Regulação da Expressão Gênica , Receptores de Hidrocarboneto Arílico , Humanos , Antígenos CD5/metabolismo , Antígenos CD5/genética , Receptores de Hidrocarboneto Arílico/metabolismo , Receptores de Hidrocarboneto Arílico/genética , Éxons/genética , Linfócitos T/imunologia , Linfócitos T/metabolismo , Regiões Promotoras Genéticas/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Ligação Proteica , Retrovirus Endógenos/genética , Retrovirus Endógenos/metabolismo , Sítios de Ligação , Células JurkatRESUMO
The neocortex is comprised of six neuronal layers that are generated in a defined temporal sequence. While extrinsic and intrinsic cues are known to regulate the sequential production of neocortical neurons, how these factors interact and function in a coordinated manner is poorly understood. The proneural gene Neurog2 is expressed in progenitors throughout corticogenesis, but is only required to specify early-born, deep-layer neuronal identities. Here, we examined how neuronal differentiation in general and Neurog2 function in particular are temporally controlled during murine neocortical development. We found that Neurog2 proneural activity declines in late corticogenesis, correlating with its phosphorylation by GSK3 kinase. Accordingly, GSK3 activity, which is negatively regulated by canonical Wnt signaling, increases over developmental time, while Wnt signaling correspondingly decreases. When ectopically activated, GSK3 inhibits Neurog2-mediated transcription in cultured cells and Neurog2 proneural activities in vivo. Conversely, a reduction in GSK3 activity promotes the precocious differentiation of later stage cortical progenitors without influencing laminar fate specification. Mechanistically, we show that GSK3 suppresses Neurog2 activity by influencing its choice of dimerization partner, promoting heterodimeric interactions with E47 (Tcfe2a), as opposed to Neurog2-Neurog2 homodimer formation, which occurs when GSK3 activity levels are low. At the functional level, Neurog2-E47 heterodimers have a reduced ability to transactivate neuronal differentiation genes compared with Neurog2-Neurog2 homodimers, both in vitro and in vivo. We thus conclude that the temporal regulation of Neurog2-E47 heterodimerization by GSK3 is a central component of the neuronal differentiation "clock" that coordinates the timing and tempo of neocortical neurogenesis in mouse.
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Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , Quinase 3 da Glicogênio Sintase/fisiologia , Neocórtex/citologia , Neocórtex/fisiologia , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/fisiologia , Neurônios/fisiologia , Animais , Células Cultivadas , Imunoprecipitação da Cromatina , Cromatografia em Gel , Clonagem Molecular , Dimerização , Eletroporação , Feminino , Genes Reporter/genética , Meia-Vida , Sequências Hélice-Alça-Hélice/genética , Imuno-Histoquímica , Hibridização In Situ , Camundongos , Neocórtex/crescimento & desenvolvimento , Neurogênese/genética , Neurogênese/fisiologia , Fosforilação , Gravidez , Processamento de Proteína Pós-Traducional , Reação em Cadeia da Polimerase em Tempo Real , Células-Tronco/fisiologiaRESUMO
CONTEXT: Cisplatin, a coordination platinum complex, is used as a potential anti-neoplastic agent, having well recognized DNA-damaging property that triggers cell-cycle arrest and cell death in cancer therapy. Beneficial chemotherapeutic actions of cisplatin can be detrimental for kidneys. BACKGROUND: Unbound cisplatin gets accumulated in renal tubular cells, leading to cell injury and death. This liable action of cisplatin on kidneys is mediated by altered intracellular signalling pathways such as mitogen-activated protein kinase (MAPK), extracellular regulated kinase (ERK), or C- Jun N terminal kinase/stress-activated protein kinase (JNK/SAPK). Further, these signalling alterations are responsible for release and activation of tumour necrosis factor (TNF-α), mitochondrial dysfunction, and apoptosis, which ultimately cause the renal pathogenic process. Cisplatin itself enhances the generation of reactive oxygen species (ROS) and activation of nuclear factor-κB (NF-κB), inflammation, and mitochondrial dysfunction, which further leads to renal apoptosis. Cisplatin-induced nephropathy is also mediated through the p53 and protein kinase-Cδ (PKCδ) signalling pathways. OBJECTIVE: This review explores these signalling alterations and their possible role in the pathogenesis of cisplatin-induced renal injury.
Assuntos
Antineoplásicos/farmacologia , Cisplatino/farmacologia , Nefropatias/metabolismo , Animais , Glutationa/metabolismo , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Nefropatias/induzido quimicamente , Nefropatias/patologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Proteína Quinase C-delta/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/metabolismoRESUMO
BACKGROUND: Hydrocephalus of tubercular origin is one of the most dreaded and difficult to manage complications of brain tuberculosis. Traditionally, the management has been ventriculoperitoneal shunting, but in recent years emerging interest is in endoscopic ventriculostomy. In this article, we discuss the management protocol of hydrocephalus in various stages of disease. METHODS: A total of 424 cases of tubercular origin hydrocephalus were managed between years 2000 and 2009. Initially the cases were managed by ventriculoperitoneal shunting, which was followed by use of endoscopic third ventriculostomy. Drug-resistant cases were also encountered and managed according to drug sensitivity. RESULTS: The results provided through evaluation of retrospective data showed a high mortality in cases of hydrocephalus of acute origin if endoscopic third ventriculostomy was performed. The cerebrospinal fluid protein level and neurological status of the patient determined the success or failure of the procedure. For better management, patients were divided into six groups and their management underlined. CONCLUSION: The cases of tubercular meningitis with aqueductal stenosis presenting in early stages should be given a trial of endoscopic third ventriculostomy where chronic burnt-out cases or cases with communicating hydrocephalus should be managed by ventriculoperitoneal shunting.
Assuntos
Hidrocefalia/cirurgia , Ventriculostomia , Endoscopia/métodos , Humanos , Hidrocefalia/etiologia , Estudos Retrospectivos , Terceiro Ventrículo/cirurgia , Resultado do Tratamento , Tuberculose Meníngea/complicações , Tuberculose Meníngea/cirurgia , Ventriculostomia/efeitos adversos , Ventriculostomia/métodosRESUMO
Cryptococcosis is the third most commonly occurring invasive fungal disease in solid organ transplant recipients (SOT). It is caused by encapsulated yeast, Cryptococcus species, predominantly Cryptococcus neoformans and Cryptococcus gattii. Though kidney transplant recipients are at the lowest risk of cryptococcosis when compared to other solid organ transplant recipients such as lung, liver or heart, still this opportunistic infection causes significant morbidity and mortality in this subset of patients. Mortality rates with cryptococcosis range from 10%-25%, while it can be as high as 50% in SOT recipients with central nervous system involvement. The main aim of diagnosis is to find out if there is any involvement of the central nervous system in disseminated disease or whether there is only localized pulmonary involvement as it has implications for both prognostication and treatment. Detection of cryptococcal antigen (CrAg) in cerebrospinal fluid or plasma is a highly recommended test as it is more sensitive and specific than India ink and fungal cultures. The CrAg lateral flow assay is the single point of care test that can rapidly detect cryptococcal polysaccharide capsule. Treatment of cryptococcosis is challenging in kidney transplant recipients. Apart from the reduction or optimization of immunosuppression, lipid formulations of amphotericin B are preferred as induction antifungal agents. Consolidation and maintenance are done with fluconazole; carefully monitoring its interactions with calcineurin inhibitors. This review further discusses in depth the evolving developments in the epidemiology, pathogenesis, diagnostic assays, and management approach of cryptococcosis in kidney transplant recipients.
RESUMO
BACKGROUND: The ionic interactions play an important role in the stabilization of the native conformation of proteins. Toxoplasma gondii Ferredoxin NADP+ Reductase (TgFNR) remains stable at pH 4.0. However, such modulation of ionic interactions leads to compaction and non-cooperativity in its folding. OBJECTIVE: To gain insights into the role of ionic interactions in the modulation of structure and thermodynamic stability of TgFNR. METHODS: Protein preparations, circular dichroism and fluorescence spectroscopy were used to determine salt-induced changes in the structure and stability of TgFNR. RESULTS: The kosmotropic salts (sodium fluoride and sodium sulphate) appear to induce the biphasic response on the structure and stability of TgFNR. At pH about 4.0, the addition of low concentrations of kosmotropic salts significantly perturbs the existing native-like secondary structure of TgFNR, whereas higher quantities of salt reversed the denaturing impact. This is a one-of-a-kind situation we are unaware of in any other protein. The urea-induced unfolding of TgFNR in the presence of a low dose of salt (100 mM) drastically affected the protein's thermodynamic stability at neutral pH. The increased salt concentrations, on the other hand, reversed the destabilizing effect. CONCLUSION: Our findings imply that electrostatic interactions are exceptionally significant for the TgFNR stability, however, render highly unusual behavior of Hofmeister series salts, indicating a possible crucial role of salt bridges in the stabilization of different conformations of the protein.