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1.
Cell ; 147(2): 332-43, 2011 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-21982154

RESUMO

The immunoglobulin heavy-chain (IgH) gene locus undergoes radial repositioning within the nucleus and locus contraction in preparation for gene recombination. We demonstrate that IgH locus conformation involves two levels of chromosomal compaction. At the first level, the locus folds into several multilooped domains. One such domain at the 3' end of the locus requires an enhancer, Eµ; two other domains at the 5' end are Eµ independent. At the second level, these domains are brought into spatial proximity by Eµ-dependent interactions with specific sites within the V(H) region. Eµ is also required for radial repositioning of IgH alleles, indicating its essential role in large-scale chromosomal movements in developing lymphocytes. Our observations provide a comprehensive view of the conformation of IgH alleles in pro-B cells and the mechanisms by which it is established.


Assuntos
Linfócitos B/metabolismo , Núcleo Celular/genética , Cromatina/química , Genes de Cadeia Pesada de Imunoglobulina , Cadeias Pesadas de Imunoglobulinas/genética , Animais , Fator de Ligação a CCCTC , Elementos Facilitadores Genéticos , Região Variável de Imunoglobulina , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Proteínas Repressoras/metabolismo , Recombinação V(D)J , Fator de Transcrição YY1/metabolismo
2.
Nat Methods ; 19(7): 854-864, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35761067

RESUMO

Lactylation was initially discovered on human histones. Given its nascence, its occurrence on nonhistone proteins and downstream functional consequences remain elusive. Here we report a cyclic immonium ion of lactyllysine formed during tandem mass spectrometry that enables confident protein lactylation assignment. We validated the sensitivity and specificity of this ion for lactylation through affinity-enriched lactylproteome analysis and large-scale informatic assessment of nonlactylated spectral libraries. With this diagnostic ion-based strategy, we confidently determined new lactylation, unveiling a wide landscape beyond histones from not only the enriched lactylproteome but also existing unenriched human proteome resources. Specifically, by mining the public human Meltome Atlas, we found that lactylation is common on glycolytic enzymes and conserved on ALDOA. We also discovered prevalent lactylation on DHRS7 in the draft of the human tissue proteome. We partially demonstrated the functional importance of lactylation: site-specific engineering of lactylation into ALDOA caused enzyme inhibition, suggesting a lactylation-dependent feedback loop in glycolysis.


Assuntos
Histonas , Proteoma , Glicólise , Histonas/metabolismo , Humanos , Oxirredutases/metabolismo , Proteoma/metabolismo , Espectrometria de Massas em Tandem/métodos
3.
Brief Bioinform ; 24(1)2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36578163

RESUMO

Understanding drug selectivity mechanism is a long-standing issue for helping design drugs with high specificity. Designing drugs targeting cyclin-dependent kinases (CDKs) with high selectivity is challenging because of their highly conserved binding pockets. To reveal the underlying general selectivity mechanism, we carried out comprehensive analyses from both the thermodynamics and kinetics points of view on a representative CDK12 inhibitor. To fully capture the binding features of the drug-target recognition process, we proposed to use kinetic residue energy analysis (KREA) in conjunction with the community network analysis (CNA) to reveal the underlying cooperation effect between individual residues/protein motifs to the binding/dissociating process of the ligand. The general mechanism of drug selectivity in CDKs can be summarized as that the difference of structural cooperation between the ligand and the protein motifs leads to the difference of the energetic contribution of the key residues to the ligand. The proposed mechanisms may be prevalent in drug selectivity issues, and the insights may help design new strategies to overcome/attenuate the drug selectivity associated problems.


Assuntos
Quinases Ciclina-Dependentes , Simulação de Dinâmica Molecular , Quinases Ciclina-Dependentes/metabolismo , Ligantes , Ligação Proteica , Termodinâmica
4.
Nat Chem Biol ; 19(12): 1480-1491, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37322158

RESUMO

Hyperactivated glycolysis is a metabolic hallmark of most cancer cells. Although sporadic information has revealed that glycolytic metabolites possess nonmetabolic functions as signaling molecules, how these metabolites interact with and functionally regulate their binding targets remains largely elusive. Here, we introduce a target-responsive accessibility profiling (TRAP) approach that measures changes in ligand binding-induced accessibility for target identification by globally labeling reactive proteinaceous lysines. With TRAP, we mapped 913 responsive target candidates and 2,487 interactions for 10 major glycolytic metabolites in a model cancer cell line. The wide targetome depicted by TRAP unveils diverse regulatory modalities of glycolytic metabolites, and these modalities involve direct perturbation of enzymes in carbohydrate metabolism, intervention of an orphan transcriptional protein's activity and modulation of targetome-level acetylation. These results further our knowledge of how glycolysis orchestrates signaling pathways in cancer cells to support their survival, and inspire exploitation of the glycolytic targetome for cancer therapy.


Assuntos
Fenômenos Bioquímicos , Neoplasias , Humanos , Glicólise , Neoplasias/metabolismo , Transdução de Sinais , Linhagem Celular
5.
Med Res Rev ; 44(2): 568-586, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37899676

RESUMO

Nonalcoholic fatty liver disease, also called metabolic dysfunction-associated steatotic liver disease, is the most common liver disease worldwide and has no approved pharmacotherapy. Due to its beneficial effects on metabolic regulation, inflammation suppression, cell death prevention, and fibrogenesis inhibition, farnesoid X receptor (FXR) is widely accepted as a promising therapeutic target for nonalcoholic steatosis (NASH) or called metabolic dysfunction-associated steatohepatitis (MASH). Many FXR agonists have been developed for NASH/MASH therapy. Obeticholic acid (OCA) is the pioneering frontrunner FXR agonist and the first demonstrating success in clinical trials. Unfortunately, OCA did not receive regulatory approval as a NASH pharmacotherapy because its moderate benefits did not outweigh its safety risks, which may cast a shadow over FXR-based drug development for NASH/MASH. This review summarizes the milestones in the development of OCA for NASH/MASH and discuss its limitations, including moderate hepatoprotection and the undesirable side effects of dyslipidemia, pruritus, cholelithiasis, and liver toxicity risk, in depth. More importantly, we provide perspectives on FXR-based therapy for NASH/MASH, hoping to support a successful bench-to-clinic transition.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Ácido Quenodesoxicólico/farmacologia , Ácido Quenodesoxicólico/uso terapêutico
6.
Emerg Infect Dis ; 30(7): 1425-1429, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38848249

RESUMO

During March and April 2024, we studied dairy cattle specimens from a single farm in Texas, USA, using multiple molecular, cell culture, and next-generation sequencing pathogen detection techniques. Here, we report evidence that highly pathogenic avian influenza A(H5N1) virus strains of clade 2.3.4.4b were the sole cause of this epizootic.


Assuntos
Doenças dos Bovinos , Virus da Influenza A Subtipo H5N1 , Animais , Texas/epidemiologia , Bovinos , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Doenças dos Bovinos/virologia , Doenças dos Bovinos/epidemiologia , Filogenia , Influenza Aviária/virologia , Influenza Aviária/epidemiologia , Indústria de Laticínios , Feminino
7.
Anal Chem ; 96(19): 7566-7576, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38684118

RESUMO

Genetically encoding proximal-reactive unnatural amino acids (PrUaas), such as fluorosulfate-l-tyrosine (FSY), into natural proteins of interest (POI) confer the POI with the ability to covalently bind to its interacting proteins (IPs). The PrUaa-incorporated POIs hold promise for blocking undesirable POI-IP interactions. Selecting appropriate PrUaa anchor sites is crucial, but it remains challenging with the current methodology, which heavily relies on crystallography to identify the proximal residues between the POIs and the IPs for the PrUaa anchorage. To address the challenge, here, we propose a footprinting-directed genetically encoded covalent binder (footprinting-GECB) approach. This approach employs carbene footprinting, a structural mass spectrometry (MS) technique that quantifies the extent of labeling of the POI following the addition of its IP, and thus identifies the responsive residues. By genetically encoding PrUaa into these responsive sites, POI variants with covalent bonding ability to its IP can be produced without the need for crystallography. Using the POI-IP model, KRAS/RAF1, we showed that engineering FSY at the footprint-assigned KRAS residue resulted in a KRAS variant that can bind irreversibly to RAF1. Additionally, we inserted FSY at the responsive residue in RAF1 upon footprinting the oncogenic KRASG12D/RAF1, which lacks crystal structure, and generated a covalent binder to KRASG12D. Together, we demonstrated that by adopting carbene footprinting to direct PrUaa anchorage, we can greatly expand the opportunities for designing covalent protein binders for PPIs without relying on crystallography. This holds promise for creating effective PPI inhibitors and supports both fundamental research and biotherapeutics development.


Assuntos
Metano , Metano/análogos & derivados , Metano/química , Humanos , Pegadas de Proteínas/métodos , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/química , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Ligação Proteica , Espectrometria de Massas
8.
Brief Bioinform ; 23(3)2022 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-35395683

RESUMO

Drug design targeting protein-protein interactions (PPIs) associated with the development of diseases has been one of the most important therapeutic strategies. Besides interrupting the PPIs with PPI inhibitors/blockers, increasing evidence shows that stabilizing the interaction between two interacting proteins may also benefit the therapy, such as the development of various types of molecular glues/stabilizers that mostly work by stabilizing the two interacting proteins to regulate the downstream biological effects. However, characterizing the stabilization effect of a stabilizer is usually hard or too complicated for traditional experiments since it involves ternary interactions [protein-protein-stabilizer (PPS) interaction]. Thus, developing reliable computational strategies will facilitate the discovery/design of molecular glues or PPI stabilizers. Here, by fully analyzing the energetic features of the binary interactions in the PPS ternary complex, we systematically investigated the performance of molecular mechanics Poisson-Boltzmann surface area (MM/PBSA) and molecular mechanics generalized Born surface area (MM/GBSA) methods on characterizing the stabilization effects of stabilizers in 14-3-3 systems. The results show that both MM/PBSA and MM/GBSA are powerful tools in distinguishing the stabilizers from the decoys (with area under the curves of 0.90-0.93 for all tested cases) and are reasonable for ranking protein-peptide interactions in the presence or absence of stabilizers as well (with the average Pearson correlation coefficient of ~0.6 at a relatively high dielectric constant for both methods). Moreover, to give a detailed picture of the stabilization effects, the stabilization mechanism is also analyzed from the structural and energetic points of view for individual systems containing strong or weak stabilizers. This study demonstrates a potential strategy to accelerate the discovery of PPI stabilizers.


Assuntos
Simulação de Dinâmica Molecular , Proteínas , Desenho de Fármacos , Entropia , Peptídeos , Ligação Proteica , Proteínas/química
9.
Hepatology ; 77(1): 239-255, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-35460276

RESUMO

BACKGROUND AND AIMS: Peroxisome proliferator-activated receptor α (PPARα) regulates fatty acid transport and catabolism in liver. However, the role of intestinal PPARα in lipid homeostasis is largely unknown. Here, intestinal PPARα was examined for its modulation of obesity and NASH. APPROACH AND RESULTS: Intestinal PPARα was activated and fatty acid-binding protein 1 (FABP1) up-regulated in humans with obesity and high-fat diet (HFD)-fed mice as revealed by using human intestine specimens or HFD/high-fat, high-cholesterol, and high-fructose diet (HFCFD)-fed C57BL/6N mice and PPARA -humanized, peroxisome proliferator response element-luciferase mice. Intestine-specific Ppara or Fabp1 disruption in mice fed a HFD or HFCFD decreased obesity-associated metabolic disorders and NASH. Molecular analyses by luciferase reporter assays and chromatin immunoprecipitation assays in combination with fatty acid uptake assays in primary intestinal organoids revealed that intestinal PPARα induced the expression of FABP1 that in turn mediated the effects of intestinal PPARα in modulating fatty acid uptake. The PPARα antagonist GW6471 improved obesity and NASH, dependent on intestinal PPARα or FABP1. Double-knockout ( Ppara/Fabp1ΔIE ) mice demonstrated that intestinal Ppara disruption failed to further decrease obesity and NASH in the absence of intestinal FABP1. Translationally, GW6471 reduced human PPARA-driven intestinal fatty acid uptake and improved obesity-related metabolic dysfunctions in PPARA -humanized, but not Ppara -null, mice. CONCLUSIONS: Intestinal PPARα signaling promotes NASH progression through regulating dietary fatty acid uptake through modulation of FABP1, which provides a compelling therapeutic target for NASH treatment.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , PPAR alfa/metabolismo , Camundongos Endogâmicos C57BL , Fígado/metabolismo , Dieta Hiperlipídica/efeitos adversos , Obesidade/metabolismo , Camundongos Knockout , Intestinos , Proteínas de Ligação a Ácido Graxo/metabolismo , Proteínas de Ligação a Ácido Graxo/farmacologia , Ácidos Graxos/metabolismo
10.
FASEB J ; 36(9): e22468, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35913801

RESUMO

Cholestasis is a common complication of hepatitis B virus (HBV) infection, characterized by increased intrahepatic and plasma bile acid levels. Cholestasis was found negatively associated with hepatitis outcome, however, the exact mechanism by which cholestasis impacts anti-viral immunity and impedes HBV clearance remains elusive. Here, we found that cholestatic mice are featured with dysfunctional T cells response, as indicated by decreased sub-population of CD25+ /CD69+ CD4+ and CD8+ cells, while CTLA-4+ CD4+ and CD8+ subsets were increased. Mechanistically, bile acids disrupt intracellular calcium homeostasis via inhibiting mitochondria calcium uptake and elevating cytoplasmic Ca2+ concentration, leading to STIM1 and ORAI1 decoupling and impaired store-operated Ca2+ entry which is essential for NFAT signaling and T cells activation. Moreover, in a transgenic mouse model of HBV infection, we confirmed that cholestasis compromised both CD4+ and CD8+ T cells activation resulting in poor viral clearance. Collectively, our results suggest that bile acids play pivotal roles in anti-HBV infection via controlling T cells activation and metabolism and that targeting the regulation of bile acids may be a therapeutic strategy for host-virus defense.


Assuntos
Colestase , Hepatite B , Animais , Ácidos e Sais Biliares , Linfócitos T CD8-Positivos/metabolismo , Cálcio/metabolismo , Colestase/complicações , Hepatite B/complicações , Vírus da Hepatite B/metabolismo , Camundongos
11.
J Chem Inf Model ; 63(23): 7529-7544, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-37983966

RESUMO

It is well-known that the potency of a drug is heavily associated with its kinetic and thermodynamic properties with the target. Nuclear receptors (NRs), as an important target family, play important roles in regulating a variety of physiological processes in vivo. However, it is hard to understand the drug-NR interaction process because of the closed structure of the ligand-binding domain (LBD) of the NR proteins, which apparently hinders the rational design of drugs with controllable kinetic properties. Therefore, understanding the underlying mechanism of the ligand-NR interaction process seems necessary to help NR drug design. However, it is usually difficult for experimental approaches to interpret the kinetic process of drug-target interactions. Therefore, in silico methods were utilized to explore the optimal binding/dissociation pathways of the NR ligands. Specifically, farnesoid X receptor (FXR) is considered here as the target system since it has been an important target for the treatment of bile acid metabolism-associated diseases, and a series of structures cocrystallized with diverse scaffold ligands were resolved. By using random acceleration molecular dynamics (RAMD) simulation and umbrella sampling (US), 5 main dissociation pathways (pathways I-V) were identified in 11 representative FXR ligands, with most of them (9/11) preferring to go through Pathway III and the remaining two favoring escaping from Pathway I and IV. Furthermore, key residues functioning in the three main dissociation pathways were revealed by the kinetic residue energy analysis (KREA) based on the US trajectories, which may serve as road-marker residues for rapid identification of the (un)binding pathways of FXR ligands. Moreover, the preferred pathways explored by RAMD simulations are in good agreement with the minimum free energy path identified by the US simulations with the Pearson R = 0.76 between the predicted binding affinity and the experimental data, suggesting that RAMD is suitable for applying in large-scale (un)binding-pathway exploration in the case of ligands with obscure binding tunnels to the target.


Assuntos
Simulação de Dinâmica Molecular , Receptores Citoplasmáticos e Nucleares , Ligantes , Ligação Proteica , Termodinâmica
12.
Bioorg Chem ; 141: 106919, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37871388

RESUMO

Endocrine therapy (ET) is a well-validated strategy for estrogen receptor α positive (ERα + ) breast cancer therapy. Despite the clinical success of current standard of care (SoC), endocrine-resistance inevitably emerges and remains a significant medical challenge. Herein, we describe the structural optimization and evaluation of a new series of selective estrogen receptor covalent antagonists (SERCAs) based on benzothiophene scaffold. Among them, compounds 15b and 39d were identified as two highly potent covalent antagonists, which exhibits superior antiproliferation activity than positive controls against MCF-7 cells and shows high selectivity over ERα negative (ERα-) cells. More importantly, their mode of covalent engagement at Cys530 residue was accurately illustrated by a cocrystal structure of 15b-bound ERαY537S (PDB ID: 7WNV) and intact mass spectrometry, respectively. Further in vivo studies demonstrated potent antitumor activity in MCF-7 xenograft mouse model and an improved safety profile. Collectively, these compounds could be promising candidates for future development of the next generation SERCAs for endocrine-resistant ERα + breast cancer.


Assuntos
Neoplasias da Mama , Antagonistas do Receptor de Estrogênio , Humanos , Camundongos , Animais , Feminino , Receptor alfa de Estrogênio , Receptores de Estrogênio , Cristalografia por Raios X , Neoplasias da Mama/tratamento farmacológico , Células MCF-7 , Antagonistas de Estrogênios
13.
Anal Chem ; 94(43): 14820-14826, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36260072

RESUMO

We report a living cell-target responsive accessibility profiling (LC-TRAP) approach to identify the targetome of silibinin (SIL), a well-established hepatoprotective natural product (NP), in HepG2 cells. Proteins showing accessibility changes, probed by covalent lysine labeling reagents and leveraged by multiplexed quantitative proteomics, following the administration of SIL to the living cells were assigned as potential targets. Among the assigned targetome, ACSL4, an enzyme essential for ferroptosis induction, might be involved in the hepatoprotective effects of SIL and hence was intensively validated. We first demonstrated that SIL protected HepG2 cells from ferroptosis dependent on ACSL4. Then, we used biophysical assays and a SIL-derivatized chemical probe to corroborate that SIL can bind to ACSL4. The ensuing enzymatic assays showed that SIL inhibited ACSL4 enzymatic activity, thereby mitigating the ACSL4-mediated ferroptosis. As such, we revealed that ACSL4 inhibition, using SIL as a model compound, represents a promising hepatoprotective strategy. Further, since TRAP probes the accessibility changes of reactive proteinaceous lysines, it can pinpoint the proximal regions where the ligand engagement may occur. Thus, the LC-TRAP analysis of SIL, the newly discovered ligand of ACSL4, and arachidonic acid (AA), the substrate, intriguingly showed that SIL and AA both affected the conformation of the K536-proximal region of ACSL4, albeit through distinct binding patterns. Collectively, we describe a straightforward LC-TRAP workflow that does not involve ligand-derived probe synthesis and is widely applicable to target discovery of NPs.


Assuntos
Ferroptose , Humanos , Silibina/farmacologia , Coenzima A Ligases/metabolismo , Ligantes , Células Hep G2 , Ácido Araquidônico
14.
Anal Chem ; 94(30): 10722-10729, 2022 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-35853240

RESUMO

Farnesoid X receptor (FXR), a member of the nuclear receptor superfamily, is a vital ligand-activated transcriptional factor, which is highly expressed in the liver, intestine, and adrenal gland. However, FXR homeostasis is influenced by many factors, such as diet and circadian rhythm, and the expression of FXR differs in diverse organs. Currently, there is no method to monitor the FXR homeostasis in real time, which restricts us from further investigating the function of FXR under physiological and pathological conditions. In this project, classic FXR agonists were selected to be modified to targeting FXR. The photo-cross-linking diazirine group and alkynyl, a click reaction group, were incorporated to the ligands. Through biorthogonal reaction, fluorophore was linked to the ligands to realize the monitoring of FXR expression in cells.


Assuntos
Fígado , Receptores Citoplasmáticos e Nucleares , Células Cultivadas , Regulação da Expressão Gênica , Fígado/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Fatores de Transcrição/metabolismo
15.
Drug Metab Dispos ; 50(5): 685-693, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34903587

RESUMO

Withaferin A (WA) is a natural steroidal compound used in Ayurvedic medicine in India and elsewhere. Although WA was used as an anticancer reagent for decades, its role in the treatment of liver diseases has only recently been experimentally explored. Here, the effects of WA in the treatment of liver injury, systematic inflammation, and liver cancer are reviewed, and the toxicity and metabolism of WA as well as pharmacological potentials of other extracts from Withania somnifera (W. somnifera) discussed. The pharmacokinetic behaviors of WA are summarized and pharmacokinetic insights into current progress and future opportunities are highlighted. SIGNIFICANCE STATEMENT: This review outlines the current experimental progress of Withaferin A (WA) hepatoprotective activities and highlights gaps in the field. This work also discusses the pharmacokinetics of WA that can be used to guide future studies for the possible treatment of liver diseases with this compound.


Assuntos
Hepatopatias , Withania , Vitanolídeos , Humanos , Hepatopatias/tratamento farmacológico , Ayurveda , Vitanolídeos/farmacocinética , Vitanolídeos/uso terapêutico
16.
FASEB J ; 35(11): e21968, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34644426

RESUMO

St. John's wort (SJW), from traditional herbs, activates the pregnane X receptor (PXR), a potential drug target for treating inflammatory bowel disease (IBD). However, how SJW alleviates dextran sodium sulfate (DSS)-induced experimental IBD by activating PXR is unknown. To test this, PXR-humanized, wild-type (WT) and Pxr-null mice, primary intestinal organoids cultures, and the luciferase reporter gene assays were employed. In vivo, a diet supplemented with SJW was found to activate intestinal PXR both in WT and PXR-humanized mice, but not in Pxr-null mice. SJW prevented DSS-induced IBD in PXR-humanized and WT mice, but not in Pxr-null mice. In vitro, hyperforin, a major component of SJW, activated PXR and suppressed tumor necrosis factor (TNF)α-induced nuclear factor (NF) κB translocation in primary intestinal organoids from PXR-humanized mice, but not Pxr-null mice. Luciferase reporter gene assays showed that hyperforin dose-dependently alleviated TNFα-induced NFκB transactivation by activating human PXR in Caco2 cells. Furthermore, SJW therapeutically attenuated DSS-induced IBD in PXR-humanized mice. These data indicate the therapeutic potential of SJW in alleviating DSS-induced IBD in vivo, and TNFα-induced NFκB activation in vitro, dependent on PXR activation, which may have clinical implications for using SJW as a herbal drug anti-IBD treatment.


Assuntos
Anti-Inflamatórios/farmacologia , Hypericum/química , Doenças Inflamatórias Intestinais/tratamento farmacológico , Extratos Vegetais/farmacologia , Receptor de Pregnano X/fisiologia , Animais , Células CACO-2 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/metabolismo
17.
Brain Behav Immun ; 102: 11-22, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35143877

RESUMO

Gut microbiome disturbances have been widely implicated in major depressive disorder (MDD), although the identity of causal microbial species and the underlying mechanisms are yet to be fully elucidated. Here we show that Bacteroides species enriched in the gut microbiome from MDD patients differentially impact the susceptibility to depressive behaviors. Transplantation of fecal microbiome from MDD patients into antibiotic-treated mice induced anxiety and despair-like behavior and impaired hippocampal neurogenesis. Colonization of Bacteroides fragilis, Bacteroides uniformis, and, to a lesser extent, Bacteroides caccae, but not Bacteroides ovatus, recapitulated the negative effects of MDD microbiome on behavior and neurogenesis. The varying impacts of Bacteroides species were partially explained by differential alternations of tryptophan pathway metabolites and neurotransmitters along the gut-brain axis. Notably, an intensified depletion of cerebral serotonin concurred with the enhanced susceptibility to depression. Together, these findings identify select Bacteroidetes species that contribute to depression susceptibility in mice by metabolic regulation along the gut-brain axis.


Assuntos
Transtorno Depressivo Maior , Microbioma Gastrointestinal , Animais , Bacteroides , Encéfalo/metabolismo , Depressão/metabolismo , Transtorno Depressivo Maior/metabolismo , Microbioma Gastrointestinal/fisiologia , Humanos , Camundongos
18.
J Chem Inf Model ; 62(17): 3993-4007, 2022 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-36040137

RESUMO

The mechanism of transcriptional activation/repression of the nuclear receptors (NRs) involves two main conformations of the NR protein, namely, the active (agonistic) and inactive (antagonistic) conformations. Binding of agonists or antagonists to the ligand-binding pocket (LBP) of NRs can regulate the downstream signaling pathways with different physiological effects. However, it is still hard to determine the molecular type of a LBP-bound ligand because both the agonists and antagonists bind to the same position of the protein. Therefore, it is necessary to develop precise and efficient methods to facilitate the discrimination of agonists and antagonists targeting the LBP of NRs. Here, combining structural and energetic analyses with machine-learning (ML) algorithms, we constructed a series of structure-based ML models to determine the molecular category of the LBP-bound ligands. We show that the proposed models work robustly and with high accuracy (ACC > 0.9) for determining the category of molecules derived from docking-based and crystallized poses. Furthermore, the models are also capable of determining the molecular category of ligands with dual opposite functions on different NRs (i.e., working as an agonist in one NR target, whereas functioning as an antagonist in another) with reasonable accuracy. The proposed method is expected to facilitate the determination of the molecular properties of ligands targeting the LBP of NRs with structural interpretation.


Assuntos
Aprendizado de Máquina , Receptores Citoplasmáticos e Nucleares , Sítios de Ligação , Ligantes
19.
Phytother Res ; 36(6): 2463-2480, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35312112

RESUMO

The Ginkgo biloba leave extract (GbE) is widely applied in the prevention and treatment of atherosclerotic cardiovascular diseases in clinical practice. However, its mechanism of actions has not been totally elucidated. In this study, we confirmed the beneficial effects of GbE in alleviating hypercholesterolemia, inflammation and atherosclerosis in Ldlr-/- mice, which were fed 12 weeks of Western diet (WD). Moreover, 16S rRNA sequencing revealed that GbE treatment reshaped the WD-perturbed intestinal microbiota, particularly decreased the Firmicutes/Bacteroidetes ratio and elevated the abundance of Akkermansia, Alloprevotella, Alistipes, and Parabacteroides. Furthermore, GbE treatment downregulated the intestinal transcriptional levels of proinflammatory cytokines and enhanced the expression of tight junction proteins, exerting the roles of attenuating the intestinal inflammation as well as repairing the gut barrier. Meanwhile, the targeted metabolomic analysis displayed that GbE treatment significantly reversed the dysfunction of the microbial metabolic phenotypes, including promoting the production of short chain fatty acids, indole-3-acetate and secondary bile acids, which were correlated with the atherosclerotic plaque areas. Finally, we confirmed GbE-altered gut microbiota was sufficient to alleviate atherosclerosis by fecal microbiota transplantation. In summary, our findings provide important insights into the pharmacological mechanism underlying the antiatherogenic efficacy of GbE.


Assuntos
Aterosclerose , Microbioma Gastrointestinal , Animais , Aterosclerose/tratamento farmacológico , Aterosclerose/metabolismo , Ginkgo biloba , Inflamação/tratamento farmacológico , Camundongos , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , RNA Ribossômico 16S/genética
20.
AAPS PharmSciTech ; 24(1): 31, 2022 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-36577873

RESUMO

Metformin hydrochloride enteric-coated capsule (MH-EC) is a commonly used clinical drug for the treatment of type 2 diabetes. In this study, we described a metformin hydrochloride mucosal nanoparticles enteric-coated capsule (MH-MNPs-EC) based on metformin hydrochloride chitosan mucosal nanoparticles (MH-CS MNPs) and its preparation method to improve the bioavailability and hypoglycemic effect duration of MH-EC. In intestinal adhesion study, the residue rates of free drugs and mucosal nanoparticles were 10.52% and 67.27%, respectively after cleaned with PBS buffer. MH-CS MNPs could significantly improve the efficacy of MH and promote the rehabilitation of diabetes rats. In vitro release test of MH-MNPs-EC showed continuous release over 12 h, while commercial MH-EC released completely within about 1 h in intestinal environment (pH 6.8). Pharmacokinetic study was performed in beagle dogs compared to the commercial MH-EC. The durations of blood MH concentration above 2 µg/mL were 9 h for MH-MNPs-EC versus 2 h for commercial MH-EC. The relative bioavailability of MH-MNPs-EC was determined as 185.28%, compared with commercial MH-EC. In conclusion, MH-CS MNPs have good intestinal adhesion and can significantly prolong the residence time of MH in the intestine. MH-MNPs-EC has better treatment effect compared with MH-EC, and it is expected to be a potential drug product for the treatment of diabetes because of its desired characteristics.


Assuntos
Quitosana , Diabetes Mellitus Tipo 2 , Metformina , Nanopartículas , Animais , Ratos , Cães , Hipoglicemiantes/química , Metformina/química , Disponibilidade Biológica , Intestinos , Nanopartículas/química , Quitosana/química
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