Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 154
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cell ; 186(4): 764-785.e21, 2023 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-36803604

RESUMO

The choroid plexus (ChP) is the blood-cerebrospinal fluid (CSF) barrier and the primary source of CSF. Acquired hydrocephalus, caused by brain infection or hemorrhage, lacks drug treatments due to obscure pathobiology. Our integrated, multi-omic investigation of post-infectious hydrocephalus (PIH) and post-hemorrhagic hydrocephalus (PHH) models revealed that lipopolysaccharide and blood breakdown products trigger highly similar TLR4-dependent immune responses at the ChP-CSF interface. The resulting CSF "cytokine storm", elicited from peripherally derived and border-associated ChP macrophages, causes increased CSF production from ChP epithelial cells via phospho-activation of the TNF-receptor-associated kinase SPAK, which serves as a regulatory scaffold of a multi-ion transporter protein complex. Genetic or pharmacological immunomodulation prevents PIH and PHH by antagonizing SPAK-dependent CSF hypersecretion. These results reveal the ChP as a dynamic, cellularly heterogeneous tissue with highly regulated immune-secretory capacity, expand our understanding of ChP immune-epithelial cell cross talk, and reframe PIH and PHH as related neuroimmune disorders vulnerable to small molecule pharmacotherapy.


Assuntos
Plexo Corióideo , Hidrocefalia , Humanos , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Plexo Corióideo/metabolismo , Hidrocefalia/líquido cefalorraquidiano , Hidrocefalia/imunologia , Imunidade Inata , Síndrome da Liberação de Citocina/patologia
2.
Proc Natl Acad Sci U S A ; 121(27): e2314702121, 2024 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-38916997

RESUMO

Enlargement of the cerebrospinal fluid (CSF)-filled brain ventricles (cerebral ventriculomegaly), the cardinal feature of congenital hydrocephalus (CH), is increasingly recognized among patients with autism spectrum disorders (ASD). KATNAL2, a member of Katanin family microtubule-severing ATPases, is a known ASD risk gene, but its roles in human brain development remain unclear. Here, we show that nonsense truncation of Katnal2 (Katnal2Δ17) in mice results in classic ciliopathy phenotypes, including impaired spermatogenesis and cerebral ventriculomegaly. In both humans and mice, KATNAL2 is highly expressed in ciliated radial glia of the fetal ventricular-subventricular zone as well as in their postnatal ependymal and neuronal progeny. The ventriculomegaly observed in Katnal2Δ17 mice is associated with disrupted primary cilia and ependymal planar cell polarity that results in impaired cilia-generated CSF flow. Further, prefrontal pyramidal neurons in ventriculomegalic Katnal2Δ17 mice exhibit decreased excitatory drive and reduced high-frequency firing. Consistent with these findings in mice, we identified rare, damaging heterozygous germline variants in KATNAL2 in five unrelated patients with neurosurgically treated CH and comorbid ASD or other neurodevelopmental disorders. Mice engineered with the orthologous ASD-associated KATNAL2 F244L missense variant recapitulated the ventriculomegaly found in human patients. Together, these data suggest KATNAL2 pathogenic variants alter intraventricular CSF homeostasis and parenchymal neuronal connectivity by disrupting microtubule dynamics in fetal radial glia and their postnatal ependymal and neuronal descendants. The results identify a molecular mechanism underlying the development of ventriculomegaly in a genetic subset of patients with ASD and may explain persistence of neurodevelopmental phenotypes in some patients with CH despite neurosurgical CSF shunting.


Assuntos
Cílios , Hidrocefalia , Microtúbulos , Animais , Hidrocefalia/genética , Hidrocefalia/patologia , Hidrocefalia/metabolismo , Humanos , Camundongos , Microtúbulos/metabolismo , Masculino , Cílios/metabolismo , Cílios/patologia , Feminino , Katanina/metabolismo , Katanina/genética , Transtorno do Espectro Autista/genética , Transtorno do Espectro Autista/patologia , Transtorno do Espectro Autista/metabolismo , Neurônios/metabolismo , Epêndima/metabolismo , Epêndima/patologia , ATPases Associadas a Diversas Atividades Celulares/genética , ATPases Associadas a Diversas Atividades Celulares/metabolismo , Células Piramidais/metabolismo , Células Piramidais/patologia
3.
RNA ; 30(6): 728-738, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38485192

RESUMO

Transcriptomics analyses play pivotal roles in understanding the complex regulatory networks that govern cellular processes. The abundance of rRNAs, which account for 80%-90% of total RNA in eukaryotes, limits the detection and investigation of other transcripts. While mRNAs and long noncoding RNAs have poly(A) tails that are often used for positive selection, investigations of poly(A)- RNAs, such as circular RNAs, histone mRNAs, and small RNAs, typically require the removal of the abundant rRNAs for enrichment. Current approaches to deplete rRNAs for downstream molecular biology investigations are hampered by restrictive RNA input masses and high costs. To address these challenges, we developed rRNA Removal by RNaseH (rRRR), a method to efficiently deplete rRNAs from a wide range of human, mouse, and rat RNA inputs and of varying qualities at a cost 10- to 20-fold cheaper than other approaches. We used probe-based hybridization and enzymatic digestion to selectively target and remove rRNA molecules while preserving the integrity of non-rRNA transcripts. Comparison of rRRR to two commercially available approaches showed similar rRNA depletion efficiencies and comparable off-target effects. Our developed method provides researchers with a valuable tool for investigating gene expression and regulatory mechanisms across a wide range of biological systems at an affordable price that increases the accessibility for researchers to enter the field, ultimately advancing our understanding of cellular processes.


Assuntos
RNA Ribossômico , RNA Ribossômico/genética , RNA Ribossômico/metabolismo , Animais , Humanos , Camundongos , Ratos , Ribonuclease H/metabolismo , Ribonuclease H/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
4.
Brain ; 147(4): 1553-1570, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38128548

RESUMO

Hydrocephalus, characterized by cerebral ventriculomegaly, is the most common disorder requiring brain surgery in children. Recent studies have implicated SMARCC1, a component of the BRG1-associated factor (BAF) chromatin remodelling complex, as a candidate congenital hydrocephalus gene. However, SMARCC1 variants have not been systematically examined in a large patient cohort or conclusively linked with a human syndrome. Moreover, congenital hydrocephalus-associated SMARCC1 variants have not been functionally validated or mechanistically studied in vivo. Here, we aimed to assess the prevalence of SMARCC1 variants in an expanded patient cohort, describe associated clinical and radiographic phenotypes, and assess the impact of Smarcc1 depletion in a novel Xenopus tropicalis model of congenital hydrocephalus. To do this, we performed a genetic association study using whole-exome sequencing from a cohort consisting of 2697 total ventriculomegalic trios, including patients with neurosurgically-treated congenital hydrocephalus, that total 8091 exomes collected over 7 years (2016-23). A comparison control cohort consisted of 1798 exomes from unaffected siblings of patients with autism spectrum disorder and their unaffected parents were sourced from the Simons Simplex Collection. Enrichment and impact on protein structure were assessed in identified variants. Effects on the human fetal brain transcriptome were examined with RNA-sequencing and Smarcc1 knockdowns were generated in Xenopus and studied using optical coherence tomography imaging, in situ hybridization and immunofluorescence. SMARCC1 surpassed genome-wide significance thresholds, yielding six rare, protein-altering de novo variants localized to highly conserved residues in key functional domains. Patients exhibited hydrocephalus with aqueductal stenosis; corpus callosum abnormalities, developmental delay, and cardiac defects were also common. Xenopus knockdowns recapitulated both aqueductal stenosis and cardiac defects and were rescued by wild-type but not patient-specific variant SMARCC1. Hydrocephalic SMARCC1-variant human fetal brain and Smarcc1-variant Xenopus brain exhibited a similarly altered expression of key genes linked to midgestational neurogenesis, including the transcription factors NEUROD2 and MAB21L2. These results suggest de novo variants in SMARCC1 cause a novel human BAFopathy we term 'SMARCC1-associated developmental dysgenesis syndrome', characterized by variable presence of cerebral ventriculomegaly, aqueductal stenosis, developmental delay and a variety of structural brain or cardiac defects. These data underscore the importance of SMARCC1 and the BAF chromatin remodelling complex for human brain morphogenesis and provide evidence for a 'neural stem cell' paradigm of congenital hydrocephalus pathogenesis. These results highlight utility of trio-based whole-exome sequencing for identifying pathogenic variants in sporadic congenital structural brain disorders and suggest whole-exome sequencing may be a valuable adjunct in clinical management of congenital hydrocephalus patients.


Assuntos
Transtorno do Espectro Autista , Aqueduto do Mesencéfalo/anormalidades , Doenças Genéticas Ligadas ao Cromossomo X , Hidrocefalia , Criança , Humanos , Transtorno do Espectro Autista/genética , Fatores de Transcrição/genética , Hidrocefalia/diagnóstico por imagem , Hidrocefalia/genética , Epigênese Genética , Proteínas do Olho/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética
5.
Plant Physiol ; 192(2): 1548-1568, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-36852886

RESUMO

Sucrose and auxin are well-known determinants of root system architecture (RSA). However, the factors that connect the signaling pathways evoked by these two critical factors during root development are poorly understood. In this study, we report the role of MEDIATOR SUBUNIT17 (MED17) in RSA and its involvement in the transcriptional integration of sugar and auxin signaling pathways in Arabidopsis (Arabidopsis thaliana). Sucrose regulates root meristem activation through the TARGET OF RAPAMYCIN-E2 PROMOTER BINDING FACTOR A (TOR-E2FA) pathway, and auxin regulates lateral root (LR) development through AUXIN RESPONSE FACTOR-LATERAL ORGAN BOUNDARIES DOMAIN (ARF-LBDs). Both sucrose and auxin play a vital role during primary and LR development. However, there is no clarity on how sucrose is involved in the ARF-dependent regulation of auxin-responsive genes. This study establishes MED17 as a nodal point to connect sucrose and auxin signaling. Transcription of MED17 was induced by sucrose in an E2FA/B-dependent manner. Moreover, E2FA/B interacted with MED17, which can aid in the recruitment of the Mediator complex on the target promoters. Interestingly, E2FA/B and MED17 also occupied the promoter of ARF7, but not ARF19, leading to ARF7 expression, which then activates auxin signaling and thus initiates LR development. MED17 also activated cell division in the root meristem by occupying the promoters of cell-cycle genes, thus regulating their transcription. Thus, MED17 plays an important role in relaying the transcriptional signal from sucrose to auxin-responsive and cell-cycle genes to regulate primary and lateral root development, highlighting the role of the Mediator as the transcriptional processor for optimal root system architecture in Arabidopsis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição/metabolismo , Mutação , Ácidos Indolacéticos/farmacologia , Ácidos Indolacéticos/metabolismo , Sacarose/farmacologia , Sacarose/metabolismo , Raízes de Plantas/metabolismo , Regulação da Expressão Gênica de Plantas
6.
J Exp Bot ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38881317

RESUMO

Mediator, a multiprotein complex, is an important component of the transcription machinery. In plants, the latest reports from our group and some other studies have established that Mediator functions as a signal processor that conveys transcriptional signals from transcription factors to RNA polymerase II. It has been found to be involved in different developmental and stress-adaptation conditions ranging from embryo, root, and shoot development to flowering and senescence and also in response to different biotic and abiotic stresses. In the last one decade, significant progress has been made in understanding the role of Mediator subunits in root development. They have been shown to transcriptionally regulate development of almost all the components of root system architecture - primary root, lateral root and root hair. Their role has also been appreciated in nutrient acquisition through root. In this review, we have discussed all the known functions of Mediator subunits during root development. We have also highlighted the role of Mediator as a nodal point for processing different hormone signaling that regulate root morphogenesis and growth.

7.
Bioorg Med Chem Lett ; 108: 129789, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38729318

RESUMO

Receptors are proteinous macromolecules which remain in the apo form under normal/unliganded conditions. As the ligand approaches, there are specific stereo-chemical changes in the apo form of the receptor as per the stereochemistry of a ligand. Accordingly, a series of substituted dimethyl-chroman-based stereochemically flexible and constrained Tamoxifen analogs were synthesized as anti-breast cancer agents. The synthesized compounds 19a-e, 20a-e, 21, and 22a-e, showed significant antiproliferative activity against estrogen receptor-positive (ER+, MCF-7) and negative (ER-, MDA MB-231) cells within IC50 value 8.5-25.0 µM. Amongst all, four potential molecules viz 19b, 19e, 22a, and 22c, were evaluated for their effect on the cell division cycle and apoptosis of ER+ and ER- cancer cells (MCF-7 & MDA MB-231cells), which showed that these compounds possessed antiproliferative activity through triggering apoptosis. In-silico docking experiments elucidated the possible affinity of compounds with estrogen receptors-α and -ß.


Assuntos
Antineoplásicos , Apoptose , Neoplasias da Mama , Proliferação de Células , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Estereoisomerismo , Relação Estrutura-Atividade , Linhagem Celular Tumoral , Apoptose/efeitos dos fármacos , Cromanos/farmacologia , Cromanos/síntese química , Cromanos/química , Simulação de Acoplamento Molecular , Receptor alfa de Estrogênio/metabolismo , Receptor alfa de Estrogênio/antagonistas & inibidores , Feminino , Estrutura Molecular , Células MCF-7 , Relação Dose-Resposta a Droga , Tamoxifeno/farmacologia , Tamoxifeno/síntese química , Tamoxifeno/química
8.
J Biochem Mol Toxicol ; 37(5): e23330, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36890713

RESUMO

Cardiomyopathy (CDM) and related morbidity and mortality are increasing at an alarming rate, in large part because of the increase in the number of diabetes mellitus cases. The clinical consequence associated with CDM is heart failure (HF) and is considerably worse for patients with diabetes mellitus, as compared to nondiabetics. Diabetic cardiomyopathy (DCM) is characterized by structural and functional malfunctioning of the heart, which includes diastolic dysfunction followed by systolic dysfunction, myocyte hypertrophy, cardiac dysfunctional remodeling, and myocardial fibrosis. Indeed, many reports in the literature indicate that various signaling pathways, such as the AMP-activated protein kinase (AMPK), silent information regulator 1 (SIRT1), PI3K/Akt, and TGF-ß/smad pathways, are involved in diabetes-related cardiomyopathy, which increases the risk of functional and structural abnormalities of the heart. Therefore, targeting these pathways augments the prevention as well as treatment of patients with DCM. Alternative pharmacotherapy, such as that using natural compounds, has been shown to have promising therapeutic effects. Thus, this article reviews the potential role of the quinazoline alkaloid, oxymatrine obtained from the Sophora flavescensin CDM associated with diabetes mellitus. Numerous studies have given a therapeutic glimpse of the role of oxymatrine in the multiple secondary complications related to diabetes, such as retinopathy, nephropathy, stroke, and cardiovascular complications via reductions in oxidative stress, inflammation, and metabolic dysregulation, which might be due to targeting signaling pathways, such as AMPK, SIRT1, PI3K/Akt, and TGF-ß pathways. Thus, these pathways are considered central regulators of diabetes and its secondary complications, and targeting these pathways with oxymatrine might provide a therapeutic tool for the diagnosis and treatment of diabetes-associated cardiomyopathy.


Assuntos
Alcaloides , Diabetes Mellitus , Cardiomiopatias Diabéticas , Resistência à Insulina , Humanos , Proteínas Quinases Ativadas por AMP/metabolismo , Sirtuína 1/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Cardiomiopatias Diabéticas/tratamento farmacológico , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta
9.
Fetal Pediatr Pathol ; 42(1): 98-102, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35286176

RESUMO

Background: B-cell acute lymphoblastic leukemia is known for heterogeneous blast morphology. Cytoplasmic granules and blebs have both been described, but not together, in lymphoblasts. Case presentation: A 7-year-old boy presented with fever, abdominal distension for 3 weeks, with hepatosplenomegaly. Investigations revealed pancytopenia, peripheral smear showing 21% blasts of varying size, displaying cytoplasmic blebbing and granulation. Marrow aspirate was hemodilute, 10% cells showed dim to moderate expression of CD45, CD10, CD19, HLA-DR confirming B-ALL. Megakaryocytic markers (CD41, CD61) were negative. Marrow biopsy showed a focus of large atypical cells displaying increased nuclear-cytoplasmic ratio, vesicular nuclear chromatin and macronucleoli, reminiscent of diffuse large B-cell lymphoma, cells strongly expressing PAX5, CD19, CD20, and bcl-2.The child was put on standard induction therapy. No blasts were detected in subsequent peripheral smears. Conclusion: To the best of our knowledge, this is the first case of pediatric B-ALL displaying granular "blebbed" blasts.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras , Masculino , Humanos , Criança , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Medula Óssea/patologia , Biópsia , Citoplasma/metabolismo , Citometria de Fluxo , Imunofenotipagem
10.
Pharmacol Res ; 182: 106358, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35863719

RESUMO

Type 2 diabetes mellitus (T2DM) the most prevalent metabolic disease that has evolved into a major public health issue. Concerning about its secondary complications, a growing body of evidence links T2DM to cognitive impairment and neurodegenerative disorders. The underlying pathology behind this secondary complication disease is yet to be fully known. Nonetheless, they are likely to be associated with poor insulin signaling as a result of insulin resistance. We have combed through a rising body of literature on insulin signaling in the normal and diabetic brains along with various factors like insulin resistance, hyperglycemia, obesity, oxidative stress, neuroinflammation and Aß plaques which can act independently or synergistically to link T2DM with cognitive impairments. Finally, we explored several pharmacological and non-pharmacological methods in the hopes of accelerating the rational development of medications for cognitive impairment in T2DM by better understanding these shared pathways.


Assuntos
Disfunção Cognitiva , Diabetes Mellitus Tipo 2 , Resistência à Insulina , Encéfalo/metabolismo , Disfunção Cognitiva/complicações , Disfunção Cognitiva/etiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Insulina/metabolismo , Insulina/uso terapêutico
11.
PLoS Comput Biol ; 17(4): e1008806, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33852574

RESUMO

Voltage imaging enables monitoring neural activity at sub-millisecond and sub-cellular scale, unlocking the study of subthreshold activity, synchrony, and network dynamics with unprecedented spatio-temporal resolution. However, high data rates (>800MB/s) and low signal-to-noise ratios create bottlenecks for analyzing such datasets. Here we present VolPy, an automated and scalable pipeline to pre-process voltage imaging datasets. VolPy features motion correction, memory mapping, automated segmentation, denoising and spike extraction, all built on a highly parallelizable, modular, and extensible framework optimized for memory and speed. To aid automated segmentation, we introduce a corpus of 24 manually annotated datasets from different preparations, brain areas and voltage indicators. We benchmark VolPy against ground truth segmentation, simulations and electrophysiology recordings, and we compare its performance with existing algorithms in detecting spikes. Our results indicate that VolPy's performance in spike extraction and scalability are state-of-the-art.


Assuntos
Encéfalo , Processamento de Imagem Assistida por Computador/métodos , Neuroimagem/métodos , Neurônios/fisiologia , Software , Algoritmos , Automação , Conjuntos de Dados como Assunto , Fenômenos Eletrofisiológicos , Humanos
12.
Mol Ther ; 29(2): 611-625, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33160073

RESUMO

A first-in-human phase I trial of Vvax001, an alphavirus-based therapeutic cancer vaccine against human papillomavirus (HPV)-induced cancers was performed assessing immunological activity, safety, and tolerability. Vvax001 consists of replication-incompetent Semliki Forest virus replicon particles encoding HPV16-derived antigens E6 and E7. Twelve participants with a history of cervical intraepithelial neoplasia were included. Four cohorts of three participants were treated per dose level, ranging from 5 × 105 to 2.5 × 108 infectious particles per immunization. The participants received three immunizations with a 3-week interval. For immune monitoring, blood was drawn before immunization and 1 week after the second and third immunization. Immunization with Vvax001 was safe and well tolerated, with only mild injection site reactions, and resulted in both CD4+ and CD8+ T cell responses against E6 and E7 antigens. Even the lowest dose of 5 × 105 infectious particles elicited E6/E7-specific interferon (IFN)-γ responses in all three participants in this cohort. Overall, immunization resulted in positive vaccine-induced immune responses in 12 of 12 participants in one or more assays performed. In conclusion, Vvax001 was safe and induced immune responses in all participants. These data strongly support further clinical evaluation of Vvax001 as a therapeutic vaccine in patients with HPV-related malignancies.


Assuntos
Vacinas Anticâncer/imunologia , Vetores Genéticos/genética , Neoplasias/etiologia , Neoplasias/terapia , Infecções por Papillomavirus/complicações , Vacinas contra Papillomavirus/imunologia , Vírus da Floresta de Semliki/genética , Alphapapillomavirus/imunologia , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/genética , Vetores Genéticos/administração & dosagem , Humanos , Imunização , Neoplasias/prevenção & controle , Proteínas Oncogênicas Virais/imunologia , Proteínas E7 de Papillomavirus/imunologia , Infecções por Papillomavirus/virologia , Vacinas contra Papillomavirus/administração & dosagem , Vacinas contra Papillomavirus/genética , Proteínas Repressoras/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Resultado do Tratamento , Vacinação
13.
J Biol Chem ; 295(34): 12111-12129, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32636304

RESUMO

N-Linked glycans are critical to the infection cycle of HIV, and most neutralizing antibodies target the high-mannose glycans found on the surface envelope glycoprotein-120 (gp120). Carbohydrate-binding proteins, particularly mannose-binding lectins, have also been shown to bind these glycans. Despite their therapeutic potency, their ability to cause lymphocyte proliferation limits their application. In this study, we report one such lectin named horcolin (Hordeum vulgare lectin), seen to lack mitogenicity owing to the divergence in the residues at its carbohydrate-binding sites, which makes it a promising candidate for exploration as an anti-HIV agent. Extensive isothermal titration calorimetry experiments reveal that the lectin was sensitive to the length and branching of mannooligosaccharides and thereby the total valency. Modeling and simulation studies demonstrate two distinct modes of binding, a monovalent binding to shorter saccharides and a bivalent mode for higher glycans, involving simultaneous interactions of multiple glycan arms with the primary carbohydrate-binding sites. This multivalent mode of binding was further strengthened by interactions of core mannosyl residues with a secondary conserved site on the protein, leading to an exponential increase in affinity. Finally, we confirmed the interaction of horcolin with recombinant gp120 and gp140 with high affinity and inhibition of HIV infection at nanomolar concentrations without mitogenicity.


Assuntos
Proteína gp120 do Envelope de HIV/química , Infecções por HIV , HIV-1/química , Hordeum/química , Manose/química , Lectinas de Plantas/química , Polissacarídeos/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Animais , Células HEK293 , HIV-1/metabolismo , Hordeum/genética , Humanos , Masculino , Camundongos , Lectinas de Plantas/genética , Coelhos
14.
IUBMB Life ; 73(6): 855-865, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33724683

RESUMO

Despite sharing conserved substrate-binding residues, members of 3-hydroxyisobutyrate dehydrogenase (HIBADH) superfamily show remarkable differences in substrate preference. Cysteine residues were identified within a radius of 6 Å surrounding both the active site and the substrate entry site of HIBADH enzyme from Mycobacterium tuberculosis (MtHIBADH). Chemical modification with thiol-modifying reagents, pCMB and DTNB, abrogated the dehydrogenase activity of the enzyme. The loss in activity followed pseudo-first-order kinetics as a function of the concentration of pCMB. S-HIBA (substrate) binding provided partial protection, while NAD (cofactor) binding provided ~70% protection from thiol-modifying reagent. Site-directed mutagenesis of cysteine residues present in the MtHIBADH enzyme identified the indispensable role of Cys-210 residue, located at C-terminal domain, for its dehydrogenase activity. Cys-210 mutation to serine reduced the dehydrogenase activity by ~2-fold while mutation to alanine strikingly reduced the activity by ~140-fold. C210A mutation did not perturb the state of oligomerization of the enzyme but perturbed the secondary structure content. Structural analysis revealed the involvement of Cys-210 residue in inter-chain interaction with Gln-178, which acts as hydrogen bond donor and coordinates with Cys-210 and Gly-208 of the adjacent subunit. The data demonstrate a critical role of Cys-210 residue in maintaining the conformation and rigidity of loop composed of substrate-interacting residues involved in the entry of S-HIBA substrate in MtHIBADH.


Assuntos
Oxirredutases do Álcool/metabolismo , Proteínas de Bactérias/metabolismo , Cisteína/química , Alanina/química , Oxirredutases do Álcool/química , Oxirredutases do Álcool/efeitos dos fármacos , Oxirredutases do Álcool/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/efeitos dos fármacos , Proteínas de Bactérias/genética , Catálise , Dinitrobenzenos/farmacologia , Ligação de Hidrogênio , Modelos Moleculares , Mutagênese Sítio-Dirigida , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/genética , NAD/metabolismo , Conformação Proteica , Proteínas Recombinantes/metabolismo , Serina/química , Relação Estrutura-Atividade , Especificidade por Substrato , Ácido p-Cloromercurobenzoico/farmacologia
15.
J Comput Neurosci ; 49(2): 107-127, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33595765

RESUMO

Pain is a complex, multidimensional experience that involves dynamic interactions between sensory-discriminative and affective-emotional processes. Pain experiences have a high degree of variability depending on their context and prior anticipation. Viewing pain perception as a perceptual inference problem, we propose a predictive coding paradigm to characterize evoked and non-evoked pain. We record the local field potentials (LFPs) from the primary somatosensory cortex (S1) and the anterior cingulate cortex (ACC) of freely behaving rats-two regions known to encode the sensory-discriminative and affective-emotional aspects of pain, respectively. We further use predictive coding to investigate the temporal coordination of oscillatory activity between the S1 and ACC. Specifically, we develop a phenomenological predictive coding model to describe the macroscopic dynamics of bottom-up and top-down activity. Supported by recent experimental data, we also develop a biophysical neural mass model to describe the mesoscopic neural dynamics in the S1 and ACC populations, in both naive and chronic pain-treated animals. Our proposed predictive coding models not only replicate important experimental findings, but also provide new prediction about the impact of the model parameters on the physiological or behavioral read-out-thereby yielding mechanistic insight into the uncertainty of expectation, placebo or nocebo effect, and chronic pain.


Assuntos
Modelos Neurológicos , Percepção da Dor , Animais , Giro do Cíngulo , Dor , Ratos , Ratos Sprague-Dawley , Córtex Somatossensorial
16.
Biomacromolecules ; 22(7): 3069-3083, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-34152738

RESUMO

The regeneration of critical-sized bone defects with biomimetic scaffolds remains clinically challenging due to avascular necrosis, chronic inflammation, and altered osteogenic activity. Two confounding mechanisms, efficacy manipulation, and temporal regulation dictate the scaffold's bone regenerative ability. Equally critical is the priming of the mesenchymal stromal cells (MSCs) toward lineage-specific differentiation into bone-forming osteoblast, which particularly depends on varied mechanochemical and biological cues during bone tissue regeneration. This study sought to design and develop an optimized osteogenic scaffold, adenosine/epigallocatechin gallate-N,O-carboxymethyl chitosan/collagen type I (AD/EGCG-g-NOCC@clgn I), having osteoinductive components toward swift bone regeneration in a calvarial defect BALB/c mice model. The ex vivo findings distinctly establish the pro-osteogenic potential of adenosine and EGCG, stimulating MSCs toward osteoblast differentiation with significantly increased expression of alkaline phosphatase, calcium deposits, and enhanced osteocalcin expression. Moreover, the 3D matrix recapitulates extracellular matrix (ECM) properties, provides a favorable microenvironment, structural support against mechanical stress, and acts as a reservoir for sustained release of osteoinductive molecules for cell differentiation, proliferation, and migration during matrix osteointegration observed. Evidence from in vivo experiments, micro-CT analyses, histology, and histomorphometry signify accelerated osteogenesis both qualitatively and quantitatively: effectual bone union with enhanced bone formation and new ossified tissue in 4 mm sized defects. Our results suggest that the optimized scaffold serves as an adjuvant to guide bone tissue regeneration in critical-sized calvarial defects with promising therapeutic efficacy.


Assuntos
Osteogênese , Alicerces Teciduais , Adenosina , Animais , Regeneração Óssea , Catequina/análogos & derivados , Diferenciação Celular , Quitosana , Colágeno , Camundongos , Camundongos Endogâmicos BALB C
17.
J Biochem Mol Toxicol ; 35(7): e22789, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33847027

RESUMO

Previously, we established several facts regarding hypertension-associated cataractogenesis. As a follow-on study, we evaluated the role of the renin-angiotensin system (RAS) in angiotensin-II (Ang-II)-induced cataract formation in experimental hypertensive rats. Sprague-Dawley male albino rats (150-180 g) were used for the present experiment. The animals were divided into four groups, with six animals in each group. During the 12 weeks of the experimental protocol, the normal group received sterile water (1 ml/kg/day, subcutaneously (sc), and the Ang-II control group received angiotensin (1 mg/kg/day) subcutaneously. The ARB (O) group received olmesartan (2 mg/kg/day) orally, and the ARB (T) group received two drops of olmesartan (5 mM) topically on the cornea; concurrently, both groups were treated with Ang-II (1 mg/kg/day, sc) to induce hypertension. Biweekly, the systolic and the diastolic blood pressures were recorded, and the eyes were examined; moreover, cataractogenic parameters, such as oxidative stress markers and protein contents in the lenses, were evaluated after completion of the experimental protocol. Twelve weeks of olmesartan administered, orally or topically, significantly reduced the progression of cataract formation and restored antioxidants, lipid peroxidation, nitrite content, and protein contents in the lenses of the mice in groups O and T, respectively, as compared with those in the Ang-II control group. On the basis of our results, we conclude that the ocular RAS exacerbates the lenticular oxidative stress that may lead to cataract formation. The results showed that the RAS has an independent and important role in cataract formation under hypertensive conditions.


Assuntos
Angiotensina II/efeitos adversos , Catarata , Sistema Renina-Angiotensina/efeitos dos fármacos , Angiotensina II/farmacologia , Animais , Catarata/induzido quimicamente , Catarata/metabolismo , Catarata/patologia , Imidazóis/farmacologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Endogâmicos SHR , Ratos Sprague-Dawley , Tetrazóis/farmacologia
18.
Childs Nerv Syst ; 37(11): 3325-3340, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34232380

RESUMO

Congenital hydrocephalus (CH), characterized by enlarged brain ventricles, is considered a disease of pathological cerebrospinal fluid (CSF) accumulation and, therefore, treated largely by neurosurgical CSF diversion. The persistence of ventriculomegaly and poor neurodevelopmental outcomes in some post-surgical patients highlights our limited knowledge of disease mechanisms. Recent whole-exome sequencing (WES) studies have shown that rare, damaging de novo and inherited mutations with large effect contribute to ~ 25% of sporadic CH. Interestingly, multiple CH genes are key regulators of neural stem cell growth and differentiation and converge in human transcriptional networks and cell types pertinent to fetal neurogliogenesis. These data implicate genetic disruption of early brain development as the primary pathomechanism in a substantial minority of patients with sporadic CH, shedding new light on human brain development and the pathogenesis of hydrocephalus. These data further suggest WES as a clinical tool with potential to re-classify CH according to a molecular nomenclature of increased precision and utility for genetic counseling, outcome prognostication, and treatment stratification.


Assuntos
Hidrocefalia , Encéfalo , Ventrículos Cerebrais , Genômica , Humanos , Hidrocefalia/genética , Sequenciamento do Exoma
19.
Childs Nerv Syst ; 37(11): 3341-3353, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34164718

RESUMO

Reparative inflammation is an important protective response that eliminates foreign organisms, damaged cells, and physical irritants. However, inappropriately triggered or sustained inflammation can respectively initiate, propagate, or prolong disease. Post-hemorrhagic (PHH) and post-infectious hydrocephalus (PIH) are the most common forms of hydrocephalus worldwide. They are treated using neurosurgical cerebrospinal fluid (CSF) diversion techniques with high complication and failure rates. Despite their distinct etiologies, clinical studies in human patients have shown PHH and PIH share similar CSF cytokine and immune cell profiles. Here, in light of recent work in model systems, we discuss the concept of "inflammatory hydrocephalus" to emphasize potential shared mechanisms and potential therapeutic vulnerabilities of these disorders. We propose that this change of emphasis could shift our thinking of PHH and PIH from a framework of life-long neurosurgical disorders to that of preventable conditions amenable to immunomodulation.


Assuntos
Hidrocefalia , Citocinas , Hemorragia , Humanos , Hidrocefalia/cirurgia , Inflamação
20.
J Obstet Gynaecol Res ; 47(11): 3842-3848, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34463016

RESUMO

INTRODUCTION: Gestational diabetes mellitus (GDM) is a public health problem that currently affects a large part of the female population and has short- and long-term consequences for the fetus and the mother. It has been reported that GDM affects 1%-14% of all pregnancies, and that its incidence has been steadily rising. In recent years while exploring the etiological factors responsible for the emergence of insulin resistance particularly that of transient nature, vitamin D has emerged as one of the possible factors. Although systematic review and metaanalysis of observational studies show that low blood vitamin D level during pregnancy is associated with 1.8 times higher odds of GDM as compared to those having normal blood vitamin D levels; however, individual observational studies about maternal vitamin D status and risk of GDM are conflicting, The aim of this study is to compare the levels of 25(OH) vitamin D in women with gestational diabetes mellitus and normoglycemic pregnant women to assess the pathogenic role of vitamin D in the causation of GDM. MATERIALS AND METHODS: This study was conducted in the Department of Obstetrics and Gynecology, Era's Lucknow Medical College and Hospital (ELMCH), Lucknow from December 2018 to November 2020 The present study was an analytical case-control study, in which a total of 30 pregnant women in 24-28 weeks of gestation diagnosed as GDM using Diabetes in Pregnancy Study Group criteria were enrolled as cases while another 30 pregnant women in same gestational age range with normoglycemic profile were enrolled as controls. The 25(OH)D levels were assessed by the chemiluminecence immunoassay. The statistical analysis was performed using SPSS (Statistical Package for Social Sciences) Version 21.0. RESULTS: On multivariate analysis, vegetarian diet and GDM were found to be significantly associated with vitamin D deficiency. The present study endorsed the relationship between vitamin D deficiency and GDM and showed a high prevalence of vitamin D deficiency, and that too at severe level could result in GDM. Appropriate awareness and intervention strategies are warranted on a larger sample.


Assuntos
Diabetes Gestacional , Deficiência de Vitamina D , Calcifediol , Estudos de Casos e Controles , Diabetes Gestacional/epidemiologia , Feminino , Humanos , Estudos Observacionais como Assunto , Gravidez , Gestantes , Vitamina D , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/epidemiologia , Vitaminas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA