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1.
Hepatology ; 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38563629

RESUMO

BACKGROUND AND AIMS: Fibrosis is the common end point for all forms of chronic liver injury, and the progression of fibrosis leads to the development of end-stage liver disease. Activation of HSCs and their transdifferentiation into myofibroblasts results in the accumulation of extracellular matrix proteins that form the fibrotic scar. Long noncoding RNAs regulate the activity of HSCs and provide targets for fibrotic therapies. APPROACH AND RESULTS: We identified long noncoding RNA TILAM located near COL1A1 , expressed in HSCs, and induced with liver fibrosis in humans and mice. Loss-of-function studies in human HSCs and human liver organoids revealed that TILAM regulates the expression of COL1A1 and other extracellular matrix genes. To determine the role of TILAM in vivo, we annotated the mouse ortholog ( Tilam ), generated Tilam- deficient green fluorescent protein-reporter mice, and challenged these mice in 2 different models of liver fibrosis. Single-cell data and analysis of single-data and analysis of Tilam-deficient reporter mice revealed that Tilam is induced in murine HSCs with the development of fibrosis in vivo. Tilam -deficient reporter mice revealed that Tilam is induced in murine HSCs with the development of fibrosis in vivo. Furthermore, loss of Tilam expression attenuated the development of fibrosis in the setting of in vivo liver injury. Finally, we found that TILAM interacts with promyelocytic leukemia nuclear body scaffold protein to regulate a feedback loop by which TGF-ß2 reinforces TILAM expression and nuclear localization of promyelocytic leukemia nuclear body scaffold protein to promote the fibrotic activity of HSCs. CONCLUSIONS: TILAM is activated in HSCs with liver injury and interacts with promyelocytic leukemia nuclear body scaffold protein to drive the development of fibrosis. Depletion of TILAM may serve as a therapeutic approach to combat the development of end-stage liver disease.

2.
J Biol Chem ; 299(5): 104700, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37059184

RESUMO

Ribonucleoproteins (RNPs) comprise one or more RNA and protein molecules that interact to form a stable complex, which commonly involves conformational changes in the more flexible RNA components. Here, we propose that Cas12a RNP assembly with its cognate CRISPR RNA (crRNA) guide instead proceeds primarily through Cas12a conformational changes during binding to more stable, prefolded crRNA 5' pseudoknot handles. Phylogenetic reconstructions and sequence and structure alignments revealed that the Cas12a proteins are divergent in sequence and structure while the crRNA 5' repeat region, which folds into a pseudoknot and anchors binding to Cas12a, is highly conserved. Molecular dynamics simulations of three Cas12a proteins and their cognate guides revealed substantial flexibility for unbound apo-Cas12a. In contrast, crRNA 5' pseudoknots were predicted to be stable and independently folded. Limited trypsin hydrolysis, differential scanning fluorimetry, thermal denaturation, and CD analyses supported conformational changes of Cas12a during RNP assembly and an independently folded crRNA 5' pseudoknot. This RNP assembly mechanism may be rationalized by evolutionary pressure to conserve CRISPR loci repeat sequence, and therefore guide RNA structure, to maintain function across all phases of the CRISPR defense mechanism.


Assuntos
Sistemas CRISPR-Cas , RNA Guia de Sistemas CRISPR-Cas , RNA , Ribonucleoproteínas , Edição de Genes , Filogenia , Ribonucleoproteínas/genética , RNA Guia de Sistemas CRISPR-Cas/genética , Dobramento de Proteína
3.
J Phys Chem A ; 127(42): 8911-8921, 2023 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-37819373

RESUMO

The high transition dipole strength of the azide asymmetric stretch makes aryl azides good candidates as vibrational probes (VPs). However, aryl azides have complex absorption profiles due to Fermi resonances (FRs). Understanding the origin and the vibrational modes involved in FRs of aryl azides is critically important toward developing them as VPs for studies of protein structures and structural changes in response to their surroundings. As such, we studied vibrational couplings in 4-azidotoluene and 4-azido-N-phenylmaleimide in two solvents, N,N-dimethylacetamide and tetrahydrofuran, to explore the origin and the effects of intramolecular group and solvent on the FRs of aryl azides using density functional theory (DFT) calculations with the B3LYP functional and seven basis sets, 6-31G(d,p), 6-31+G(d,p), 6-31++G(d,p), 6-311G(d,p), 6-311+G(d,p), 6-311++G(d,p), and 6-311++G(df,pd). Two combination bands consisting of the azide symmetric stretch and another mode form strong FRs with the azide asymmetric stretch for both molecules. The FR profile was altered by replacing the methyl group with maleimide. Solvents change the relative peak position and intensity more significantly for 4-azido-N-phenylmaleimide, which makes it a more sensitive VP. Furthermore, the DFT results indicate that a comparison among the results from different basis sets can be used as a means to predict more reliable vibrational spectra.

4.
J Chem Phys ; 159(16)2023 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-37870142

RESUMO

Enzymes accelerate the rates of biomolecular reactions by many orders of magnitude compared to bulk solution, and it is widely understood that this catalytic effect arises from a combination of polar pre-organization and electrostatic transition state stabilization. A number of recent reports have also implicated ultrafast (femtosecond-picosecond) timescale motions in enzymatic activity. However, complications arising from spatially-distributed disorder, the occurrence of multiple substrate binding modes, and the influence of hydration dynamics on solvent-exposed active sites still confound many experimental studies. Here we use ultrafast two-dimensional infrared (2D IR) spectroscopy and covalently-tethered substrate analogs to examine dynamical properties of the promiscuous Pyrococcus horikoshii ene-reductase (PhENR) active site in two binding configurations mimicking proposed "inactive" and "reactive" Michaelis complexes. Spectral diffusion measurements of aryl-nitrile substrate analogs reveal an end-to-end tradeoff between fast (sub-ps) and slow (>5 ps) motions. Fermi resonant aryl-azide analogs that sense interactions of coupled oscillators are described. Lineshape and quantum beat analyses of these probes reveal characteristics that correlate with aryl-nitrile frequency fluctuation correlation functions parameters, demonstrating that this anisotropy is an intrinsic property of the water-exposed active site, where countervailing gradients of fast dynamics and disorder in the reactant ground state are maintained near the hydration interface. Our results suggest several plausible factors leading to state-selective rate enhancement and promiscuity in PhENR. This study also highlights a strategy to detect perturbations to vibrational modes outside the transparent window of the mid-IR spectrum, which may be extended to other macromolecular systems.


Assuntos
Nitrilas , Água , Espectrofotometria Infravermelho/métodos , Domínio Catalítico , Anisotropia , Água/química
5.
Chembiochem ; 21(19): 2792-2804, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32372560

RESUMO

Infrared spectroscopy detects the formation of G-quadruplexes in guanine-rich nucleic acid sequences through shifts in the guanine C=O stretch mode. Here, we use ultrafast 2D infrared (IR) spectroscopy and isotope substitution to show that these shifts arise from vibrational delocalization among stacked G-quartets. This provides a direct measure of the sizes of locally ordered motifs in heterogeneous samples with substantial disordered regions. We find that parallel-stranded, potassium-bound DNA G-quadruplexes are limited to five consecutive G-quartets and 3-4 consecutive layers are preferred for longer polyguanine tracts. The resulting potassium-dependent G-quadruplex assembly landscape reflects the polyguanine tract lengths found in genomes, the ionic conditions prevalent in healthy mammalian cells, and the onset of structural disorder in disease states. Our study describes spectral markers that can be used to probe other G-quadruplex structures and provides insight into the fundamental limits of their formation in biological and artificial systems.


Assuntos
DNA/química , DNA/síntese química , Quadruplex G , Humanos , Conformação de Ácido Nucleico , Tamanho da Partícula , Espectrofotometria Infravermelho
6.
J Neuroinflammation ; 14(1): 7, 2017 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-28086912

RESUMO

BACKGROUND: α/ß-Hydrolase domain 6 (ABHD6) is one of the major enzymes for endocannabinoid 2-arachidonoylglycerol (2-AG) hydrolysis in microglia cells. Our recent studies have shown that a selective ABHD6 inhibitor WWL70 has anti-inflammatory and neuroprotective effects in animal models of traumatic brain injury and multiple sclerosis. However, the role of ABHD6 in the neuroinflammatory response and the mechanisms by which WWL70 suppresses inflammation has not yet been elucidated in reactive microglia. METHODS: The hydrolytic activity and the levels of 2-AG in BV2 cells were measured by radioactivity assay and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The expression of cyclooxygenase-2 (COX-2) and prostaglandin E2 (PGE2) synthases in microglia treated with lipopolysaccharide (LPS) with/without WWL70 was determined by western blot and quantitative RT-PCR. The conversion of 2-AG to PGE2 or PGE2-glyceryl ester (PGE2-G) was assessed by enzyme-linked immunoassay (EIA) or LC-MS/MS. The involvement of ABHD6 in PGE2 production was assessed using pharmacological inhibitors and small interfering RNA (siRNA). The effect of WWL70 on PGE2 biosynthesis activity in the microsome fraction from BV2 cells and experimental autoimmune encephalopathy (EAE) mouse brain was also examined. RESULTS: We found that WWL70 suppressed PGE2 production in LPS-activated microglia via cannabinoid receptor-independent mechanisms, although intracellular levels of 2-AG were elevated by WWL70 treatment. This reduction was not attributable to WWL70 inhibition of ABHD6, given the fact that downregulation of ABHD6 by siRNA or use of KT182, an alternative ABHD6 inhibitor failed to suppress PGE2 production. WWL70 attenuated the expression of COX-2 and PGES-1/2 leading to the downregulation of the biosynthetic pathways of PGE2 and PGE2-G. Moreover, PGE2 production from arachidonic acid was reduced in the microsome fraction, indicating that WWL70 also targets PGE2 biosynthetic enzymes, which are likely to contribute to the therapeutic mechanisms of WWL70 in the EAE mouse model. CONCLUSIONS: WWL70 is an anti-inflammatory therapeutic agent capable of inhibiting PGE2 and PGE2-G production, primarily due to its reduction of COX-2 and microsomal PGES-1/2 expression and their PGE2 biosynthesis activity in microglia cells, as well as in the EAE mouse brain.


Assuntos
Ácidos Araquidônicos/metabolismo , Compostos de Bifenilo/farmacologia , Carbamatos/farmacologia , Dinoprostona/metabolismo , Endocanabinoides/metabolismo , Inibidores Enzimáticos/farmacologia , Glicerídeos/metabolismo , Microglia/efeitos dos fármacos , Monoacilglicerol Lipases/metabolismo , Animais , Agonistas de Receptores de Canabinoides/farmacologia , Antagonistas de Receptores de Canabinoides/farmacologia , Células Cultivadas , Córtex Cerebral/citologia , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/genética , Feminino , Hidrólise/efeitos dos fármacos , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Microglia/metabolismo , Piperidinas/farmacologia , Pirazóis/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Ratos , Ratos Sprague-Dawley , Rimonabanto
7.
Nat Chem Biol ; 16(3): 226-227, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32080631
8.
Proc Natl Acad Sci U S A ; 111(16): 5796-801, 2014 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-24550484

RESUMO

Polyglutamine (polyQ) sequences are found in a variety of proteins, and mutational expansion of the polyQ tract is associated with many neurodegenerative diseases. We study the amyloid fibril structure and aggregation kinetics of K2Q24K2W, a model polyQ sequence. Two structures have been proposed for amyloid fibrils formed by polyQ peptides. By forming fibrils composed of both (12)C and (13)C monomers, made possible by protein expression in Escherichia coli, we can restrict vibrational delocalization to measure 2D IR spectra of individual monomers within the fibrils. The spectra are consistent with a ß-turn structure in which each monomer forms an antiparallel hairpin and donates two strands to a single ß-sheet. Calculated spectra from atomistic molecular-dynamics simulations of the two proposed structures confirm the assignment. No spectroscopically distinct intermediates are observed in rapid-scan 2D IR kinetics measurements, suggesting that aggregation is highly cooperative. Although 2D IR spectroscopy has advantages over linear techniques, the isotope-mixing strategy will also be useful with standard Fourier transform IR spectroscopy.


Assuntos
Amiloide/metabolismo , Peptídeos/química , Peptídeos/metabolismo , Motivos de Aminoácidos , Animais , Isótopos de Carbono , Modelos Moleculares , Fenômenos Ópticos , Porfirinas/metabolismo , Ligação Proteica , Espectrofotometria Infravermelho , Cachalote , Marcadores de Spin , Termodinâmica
9.
Brain Behav Immun ; 58: 181-190, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27395434

RESUMO

Although the most notable clinical symptoms of Huntington's disease (HD) are motor disturbances and brain atrophy, other symptoms include cognitive dysfunction, emotional and hormonal dysregulation. Emotional dysregulation (irritability, anger/aggression, and anxiety) and increased inflammation are early emerging symptoms which can be detected decades before the onset of motor symptoms in HD patients. Despite the advances in understanding the genetic causes of HD there is still no cure or preventative treatment. Thus, to better understand the pathogenesis of HD and develop effective treatments, a holistic understanding of HD is needed, as well as animal models that replicate the full spectrum of HD symptoms. The current study examined the emotional, hormonal, and gene expression responses to an acute stressor of adult male transgenic HD rhesus monkeys (n=2) as compared to wild-type controls (n=2). Results revealed that HD monkeys expressed increased anxiety and irritability/aggression as compared to controls. Reactive cortisol response to the stressor was similar between groups. However, HD monkeys exhibited increased pro-inflammatory cytokines and higher induction of immune pathway genes as compared to controls. Overall, results reveal that HD monkeys exhibit these early emerging symptoms of HD and may be an effective animal model to facilitate the development of new therapeutics for HD patients.


Assuntos
Ansiedade , Comportamento Animal , Doença de Huntington/imunologia , Doença de Huntington/psicologia , Agressão , Animais , Animais Geneticamente Modificados , Proteína C-Reativa/metabolismo , Modelos Animais de Doenças , Expressão Gênica , Doença de Huntington/genética , Hidrocortisona/sangue , Interleucina-6/sangue , Leucócitos Mononucleares/metabolismo , Macaca mulatta , Masculino , Estresse Fisiológico , Fator de Necrose Tumoral alfa/sangue
10.
Proc Natl Acad Sci U S A ; 109(33): 13290-5, 2012 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-22851764

RESUMO

Androcam replaces calmodulin as a tissue-specific myosin VI light chain on the actin cones that mediate D. melanogaster spermatid individualization. We show that the androcam structure and its binding to the myosin VI structural (Insert 2) and regulatory (IQ) light chain sites are distinct from those of calmodulin and provide a basis for specialized myosin VI function. The androcam N lobe noncanonically binds a single Ca(2+) and is locked in a "closed" conformation, causing androcam to contact the Insert 2 site with its C lobe only. Androcam replacing calmodulin at Insert 2 will increase myosin VI lever arm flexibility, which may favor the compact monomeric form of myosin VI that functions on the actin cones by facilitating the collapse of the C-terminal region onto the motor domain. The tethered androcam N lobe could stabilize the monomer through contacts with C-terminal portions of the motor or recruit other components to the actin cones. Androcam binds the IQ site at all calcium levels, constitutively mimicking a conformation adopted by calmodulin only at intermediate calcium levels. Thus, androcam replacing calmodulin at IQ will abolish a Ca(2+)-regulated, calmodulin-mediated myosin VI structural change. We propose that the N lobe prevents androcam from interfering with other calmodulin-mediated Ca(2+) signaling events. We discuss how gene duplication and mutations that selectively stabilize one of the many conformations available to calmodulin support the molecular evolution of structurally and functionally distinct calmodulin-like proteins.


Assuntos
Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Drosophila/química , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Cloreto de Cálcio/metabolismo , Calmodulina/química , Calmodulina/metabolismo , Motivos EF Hand , Glicina/metabolismo , Espectroscopia de Ressonância Magnética , Modelos Moleculares , Dados de Sequência Molecular , Cadeias Pesadas de Miosina/química , Peptídeos/química , Peptídeos/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Relação Estrutura-Atividade , Titulometria
11.
Proc Natl Acad Sci U S A ; 109(9): 3329-34, 2012 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-22328156

RESUMO

The structural eye lens protein γD-crystallin is a major component of cataracts, but its conformation when aggregated is unknown. Using expressed protein ligation, we uniformly (13)C labeled one of the two Greek key domains so that they are individually resolved in two-dimensional (2D) IR spectra for structural and kinetic analysis. Upon acid-induced amyloid fibril formation, the 2D IR spectra reveal that the C-terminal domain forms amyloid ß-sheets, whereas the N-terminal domain becomes extremely disordered but lies in close proximity to the ß-sheets. Two-dimensional IR kinetics experiments show that fibril nucleation and extension occur exclusively in the C-terminal domain. These results are unexpected because the N-terminal domain is less stable in the monomer form. Isotope dilution experiments reveal that each C-terminal domain contributes two or fewer adjacent ß-strands to each ß-sheet. From these observations, we propose an initial structural model for γD-crystallin amyloid fibrils. Because only 1 µg of protein is required for a 2D IR spectrum, even poorly expressing proteins can be studied under many conditions using this approach. Thus, we believe that 2D IR and protein ligation will be useful for structural and kinetic studies of many protein systems for which IR spectroscopy can be straightforwardly applied, such as membrane and amyloidogenic proteins.


Assuntos
Amiloide/química , gama-Cristalinas/química , Humanos , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Espectrofotometria Infravermelho
12.
BMC Neurosci ; 15: 36, 2014 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-24581271

RESUMO

BACKGROUND: A two-year longitudinal study composed of morphometric MRI measures and cognitive behavioral evaluation was performed on a transgenic Huntington's disease (HD) monkey. rHD1, a transgenic HD monkey expressing exon 1 of the human gene encoding huntingtin (HTT) with 29 CAG repeats regulated by a human polyubiquitin C promoter was used together with four age-matched wild-type control monkeys. This is the first study on a primate model of human HD based on longitudinal clinical measurements. RESULTS: Changes in striatal and hippocampal volumes in rHD1 were observed with progressive impairment in motor functions and cognitive decline, including deficits in learning stimulus-reward associations, recognition memory and spatial memory. The results demonstrate a progressive cognitive decline and morphometric changes in the striatum and hippocampus in a transgenic HD monkey. CONCLUSIONS: This is the first study on a primate model of human HD based on longitudinal clinical measurements. While this study is based a single HD monkey, an ongoing longitudinal study with additional HD monkeys will be important for the confirmation of our findings. A nonhuman primate model of HD could complement other animal models of HD to better understand the pathogenesis of HD and future development of diagnostics and therapeutics through longitudinal assessment.


Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Modelos Animais de Doenças , Doença de Huntington/genética , Doença de Huntington/patologia , Proteínas do Tecido Nervoso/genética , Envelhecimento/genética , Envelhecimento/patologia , Animais , Animais Geneticamente Modificados , Humanos , Proteína Huntingtina , Estudos Longitudinais , Macaca mulatta , Masculino , Tamanho do Órgão/genética , Distribuição Tecidual
13.
F S Sci ; 5(1): 80-91, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38043603

RESUMO

OBJECTIVES: To assess the effect of simvastatin on uterine leiomyoma growth and extracellular matrix (ECM) deposition. DESIGN: Laboratory analysis of human leiomyoma cell culture, xenograft in a mouse model, and patient tissue from a clinical trial. SETTING: Academic research center. PATIENT(S): Tissue culture from human leiomyoma tissue and surgical leiomyoma tissue sections from a placebo-controlled randomized clinical trial. INTERVENTION(S): Simvastatin treatment. MAIN OUTCOME MEASURE(S): Serum concentrations, xenograft volumes, and protein expression. RESULTS: Mice xenografted with 3-dimensional human leiomyoma cultures were divided as follows: 7 untreated controls; 12 treated with activated simvastatin at 10 mg/kg body weight; and 15 at 20 mg/kg body weight. Simvastatin was detected in the serum of mice injected at the highest dose. Xenograft volumes were significantly smaller (mean 53% smaller at the highest concentration). There was dissolution of compact ECM, decreased ECM formation, and lower collagen protein expression in xenografts. Membrane type 1 matrix metalloproteinase was increased in vitro and in vivo. Matrix metalloproteinase 2 and low-density lipoprotein receptor-related protein 1 were increased in vitro. CONCLUSIONS: Simvastatin exhibited antitumoral activity with ECM degradation and decreased leiomyoma tumor volume in vivo. Activation of the matrix metalloproteinase 2, membrane type 1 matrix metalloproteinase, and low-density lipoprotein receptor-related protein 1 pathway may explain these findings.


Assuntos
Leiomioma , Neoplasias Uterinas , Feminino , Humanos , Camundongos , Animais , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 2 da Matriz/farmacologia , Sinvastatina/farmacologia , Sinvastatina/metabolismo , Sinvastatina/uso terapêutico , Metaloproteinase 14 da Matriz/metabolismo , Metaloproteinase 14 da Matriz/farmacologia , Neoplasias Uterinas/tratamento farmacológico , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/patologia , Leiomioma/tratamento farmacológico , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia , Peso Corporal , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/farmacologia , Lipoproteínas LDL/uso terapêutico
14.
Shock ; 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-39012765

RESUMO

ABSTRACT: Both abdominal radiotherapy and a nuclear event can result in gastrointestinal symptoms, including acute radiation syndrome (GI-ARS). GI-ARS is characterized by compromised intestinal barrier integrity increasing the risk for infectious complications. Physiologically relevant animal models are crucial for elucidating host responses and therapeutic targets. We aimed to determine the radiation dose requirements for creating GI-ARS in the Sinclair minipig. Male, sexually mature swine were randomly divided into sham (n = 6) and three lower hemibody radiation dosage groups of 8, 10, and 12 Gy (n = 5/group) delivered using a linear accelerator-derived X-rays (1.9 Gy/min). Animals were monitored for GI-ARS symptoms for 14 days with rectal swab and blood collection at days 0-3, 7, 10, and 14 followed by necropsy for western blotting and histology. Dose-dependent increases in weight loss, diarrhea severity, and mortality (log-rank test, p = 0.041) were seen. Villi length was significantly reduced in all irradiated animals compared to controls (p < 0.001). Serum citrulline decreased and bacterial translocation increased post-irradiation compared to controls. Increased NLRP3 levels in post-mortem jejunum were seen (p = 0.0043) as well as increased IL-1ß levels in the 12 Gy group (p = 0.041). Radiation dose and survival were associated with significant gut microbial community shifts in beta diversity. Moreover, decedents had increased Porphyromonas, Campylobacter, Bacteroides, Parvimonas, and decreased Fusobacterium and decreased Aerococcus, Lactobacillus, Prevotella, and Streptococcus. Our novel Sinclair minipig model showed dose-dependent clinical symptoms of GI-ARS. These findings provide invaluable insights into the intricate interplay between GI-ARS, intestinal inflammation, and gut microbiota alterations offering potential targets for therapeutic and diagnostic interventions after radiation exposure.

15.
Curr Biol ; 34(12): 2712-2718.e3, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38806055

RESUMO

New World porcupines (Erethizontinae) originated in South America and dispersed into North America as part of the Great American Biotic Interchange (GABI) 3-4 million years ago.1 Extant prehensile-tailed porcupines (Coendou) today live in tropical forests of Central and South America.2,3 In contrast, North American porcupines (Erethizon dorsatum) are thought to be ecologically adapted to higher-latitude temperate forests, with a larger body, shorter tail, and diet that includes bark.4,5,6,7 Limited fossils8,9,10,11,12,13 have hindered our understanding of the timing of this ecological differentiation relative to intercontinental dispersal during the GABI and expansion into temperate habitats.14,15,16,17,18 Here, we describe functionally important features of the skeleton of the extinct Erethizon poyeri, the oldest nearly complete porcupine skeleton documented from North America, found in the early Pleistocene of Florida. It differs from extant E. dorsatum in having a long, prehensile tail, grasping foot, and lacking dental specializations for bark gnawing, similar to tropical Coendou. Results from phylogenetic analysis suggest that the more arboreal characteristics found in E. poyeri are ancestral for erethizontines. Only after it expanded into temperate, Nearctic habitats did Erethizon acquire the characteristic features that it is known for today. When combined with molecular estimates of divergence times, results suggest that Erethizon was ecologically similar to a larger species of Coendou when it crossed the Isthmus of Panama by the early Pleistocene. It is likely that the range of this more tropically adapted form was limited to a continuous forested biome that extended from South America through the Gulf Coast.


Assuntos
Fósseis , Porcos-Espinhos , Porcos-Espinhos/anatomia & histologia , Animais , Fósseis/anatomia & histologia , América do Sul , Cauda/anatomia & histologia , Extinção Biológica , América do Norte , Evolução Biológica , Ecossistema
16.
ACS Chem Neurosci ; 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39197083

RESUMO

Herein we report progress toward a backup clinical candidate to the M1 positive allosteric modulator (PAM) VU319/ACP-319. Scaffold-hopping from the pyrrolo[2,3-b]pyridine-based M1 PAM VU6007477 to isomeric pyrrolo[3,2-b]pyridine and thieno[3,2-b]pyridine congeners identified several backup contenders. Ultimately, VU6007496, a pyrrolo[3,2-b]pyridine, advanced into late stage profiling, only to be plagued with unanticipated, species-specific metabolism and active/toxic metabolites which were identified in our phenotypic seizure liability in vivo screen, preventing further development. However, VU6007496 proved to be a highly selective and CNS penetrant M1 PAM, with minimal agonism, that displayed excellent multispecies IV/PO pharmacokinetics (PK), CNS penetration, no induction of long-term depression (or cholinergic toxicity) and robust efficacy in novel object recognition (minimum effective dose = 3 mg/kg p.o.). Thus, VU6007496 can serve as another valuable in vivo tool compound in rats and nonhuman primates, but not mouse, to study selective M1 activation.

17.
Biochemistry ; 52(36): 6169-81, 2013 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-23957864

RESUMO

γD-Crystallin is an abundant structural protein of the lens that is found in native and modified forms in cataractous aggregates. We establish that UV-B irradiation of γD-Crystallin leads to structurally specific modifications and precipitation via two mechanisms: amorphous aggregates and amyloid fibers. UV-B radiation causes cleavage of the backbone, in large measure near the interdomain interface, where side chain oxidations are also concentrated. 2D IR spectroscopy and expressed protein ligation localize fiber formation exclusively to the C-terminal domain of γD-Crystallin. The native ß-sandwich domains are not retained upon precipitation by either mechanism. The similarities between the amyloid forming pathways when induced by either UV-B radiation or low pH suggest that the propensity for the C-terminal ß-sandwich domain to form amyloid ß-sheets determines the misfolding pathway independent of the mechanism of denaturation.


Assuntos
Amiloide/química , Cristalino/efeitos da radiação , Raios Ultravioleta , gama-Cristalinas/efeitos da radiação , Sequência de Aminoácidos , Peptídeos beta-Amiloides/química , Catarata/etiologia , Humanos , Microscopia Eletrônica de Transmissão , Desnaturação Proteica , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Espectrofotometria Infravermelho , gama-Cristalinas/química
18.
BMC Neurosci ; 14: 88, 2013 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-23957861

RESUMO

BACKGROUND: Huntington's Disease (HD) is a progressive neurodegenerative disorder caused by an expansion in the polyglutamine (polyQ) region of the Huntingtin (HTT) gene. The clinical features of HD are characterized by cognitive, psychological, and motor deficits. Molecular instability, a core component in neurological disease progression, can be comprehensively evaluated through longitudinal transcriptomic profiling. Development of animal models amenable to longitudinal examination enables distinct disease-associated mechanisms to be identified. RESULTS: Here we report the first longitudinal study of transgenic monkeys with genomic integration of various lengths of the human HTT gene and a range of polyQ repeats. With this unique group of transgenic HD nonhuman primates (HD monkeys), we profiled over 47,000 transcripts from peripheral blood collected over a 2 year timespan from HD monkeys and age-matched wild-type control monkeys. CONCLUSIONS: Messenger RNAs with expression patterns which diverged with disease progression in the HD monkeys considerably facilitated our search for transcripts with diagnostic or therapeutic potential in the blood of human HD patients, opening up a new avenue for clinical investigation.


Assuntos
Doença de Huntington/genética , Proteínas do Tecido Nervoso/genética , Transcriptoma , Animais , Animais Geneticamente Modificados , Modelos Animais de Doenças , Progressão da Doença , Feminino , Perfilação da Expressão Gênica , Humanos , Proteína Huntingtina , Doença de Huntington/sangue , Estudos Longitudinais , Macaca mulatta , Masculino , RNA Mensageiro/metabolismo
19.
F S Sci ; 4(1): 74-89, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36273722

RESUMO

OBJECTIVE: To determine whether a curcumin-supplemented diet would prevent and/or treat uterine leiomyoma growth in our mouse xenograft model. DESIGN: Animal study. SETTING: Laboratory study. PATIENT(S): N/A. INTERVENTION(S): Curcumin-supplemented diet. MAIN OUTCOME MEASURE(S): Dietary intake, blood concentrations, tumor size, extracellular matrix protein concentrations, apoptosis markers. RESULT(S): We found that curcumin was well tolerated as a dietary supplement, free curcumin and its metabolites were detected in the serum, and exposure resulted in approximately 60% less leiomyoma xenograft growth as well as dissolution of the peripheral extracellular matrix architecture of the xenografts. The production of matrix proteins, including collagens, decreased, whereas the number of apoptotic cells in the xenografts increased. Additionally, when xenografts were placed in a uterine intramural location, we found a significantly increased apoptotic response to curcumin in the diet. CONCLUSION(S): Mice on a diet supplemented with curcumin could achieve serum concentrations sufficient to regulate human leiomyoma xenograft growth, and curcumin could play both preventive and curative roles in the treatment of uterine leiomyoma as an oral nutritional supplement.


Assuntos
Curcumina , Leiomioma , Neoplasias Uterinas , Feminino , Humanos , Animais , Camundongos , Curcumina/farmacologia , Curcumina/uso terapêutico , Curcumina/metabolismo , Neoplasias Uterinas/tratamento farmacológico , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/patologia , Xenoenxertos , Solubilidade , Leiomioma/tratamento farmacológico , Matriz Extracelular/metabolismo , Matriz Extracelular/patologia
20.
Neuron ; 111(21): 3378-3396.e9, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37657442

RESUMO

A genetically valid animal model could transform our understanding of schizophrenia (SCZ) disease mechanisms. Rare heterozygous loss-of-function (LoF) mutations in GRIN2A, encoding a subunit of the NMDA receptor, greatly increase the risk of SCZ. By transcriptomic, proteomic, and behavioral analyses, we report that heterozygous Grin2a mutant mice show (1) large-scale gene expression changes across multiple brain regions and in neuronal (excitatory and inhibitory) and non-neuronal cells (astrocytes and oligodendrocytes), (2) evidence of hypoactivity in the prefrontal cortex (PFC) and hyperactivity in the hippocampus and striatum, (3) an elevated dopamine signaling in the striatum and hypersensitivity to amphetamine-induced hyperlocomotion (AIH), (4) altered cholesterol biosynthesis in astrocytes, (5) a reduction in glutamatergic receptor signaling proteins in the synapse, and (6) an aberrant locomotor pattern opposite of that induced by antipsychotic drugs. These findings reveal potential pathophysiologic mechanisms, provide support for both the "hypo-glutamate" and "hyper-dopamine" hypotheses of SCZ, and underscore the utility of Grin2a-deficient mice as a genetic model of SCZ.


Assuntos
Dopamina , Proteômica , Receptores de N-Metil-D-Aspartato , Animais , Camundongos , Encéfalo/metabolismo , Dopamina/metabolismo , Neuroglia/metabolismo , Neurônios/metabolismo , Córtex Pré-Frontal/metabolismo , Modelos Animais de Doenças , Receptores de N-Metil-D-Aspartato/genética
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