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1.
Plant J ; 119(3): 1386-1399, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38843154

RESUMO

Ghost introgression, or the transfer of genetic material from extinct or unsampled lineages to sampled species, has attracted much attention. However, conclusive evidence for ghost introgression, especially in plant species, remains scarce. Here, we newly assembled chromosome-level genomes for both Carya sinensis and Carya cathayensis, and additionally re-sequenced the whole genomes of 43 C. sinensis individuals as well as 11 individuals representing 11 diploid hickory species. These genomic datasets were used to investigate the reticulation and bifurcation patterns within the genus Carya (Juglandaceae), with a particular focus on the beaked hickory C. sinensis. By combining the D-statistic and BPP methods, we obtained compelling evidence that supports the occurrence of ghost introgression in C. sinensis from an extinct ancestral hickory lineage. This conclusion was reinforced through the phylogenetic network analysis and a genome scan method VolcanoFinder, the latter of which can detect signatures of adaptive introgression from unknown donors. Our results not only dispel certain misconceptions about the phylogenetic history of C. sinensis but also further refine our understanding of Carya's biogeography via divergence estimates. Moreover, the successful integration of the D-statistic and BPP methods demonstrates their efficacy in facilitating a more precise identification of introgression types.


Assuntos
Introgressão Genética , Genoma de Planta , Filogenia , Genoma de Planta/genética , Genômica , Ásia Oriental , População do Leste Asiático
2.
Syst Biol ; 73(1): 207-222, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38224495

RESUMO

In recent years, the study of hybridization and introgression has made significant progress, with ghost introgression-the transfer of genetic material from extinct or unsampled lineages to extant species-emerging as a key area for research. Accurately identifying ghost introgression, however, presents a challenge. To address this issue, we focused on simple cases involving 3 species with a known phylogenetic tree. Using mathematical analyses and simulations, we evaluated the performance of popular phylogenetic methods, including HyDe and PhyloNet/MPL, and the full-likelihood method, Bayesian Phylogenetics and Phylogeography (BPP), in detecting ghost introgression. Our findings suggest that heuristic approaches relying on site-pattern counts or gene-tree topologies struggle to differentiate ghost introgression from introgression between sampled non-sister species, frequently leading to incorrect identification of donor and recipient species. The full-likelihood method BPP uses multilocus sequence alignments directly-hence taking into account both gene-tree topologies and branch lengths, by contrast, is capable of detecting ghost introgression in phylogenomic datasets. We analyzed a real-world phylogenomic dataset of 14 species of Jaltomata (Solanaceae) to showcase the potential of full-likelihood methods for accurate inference of introgression.


Assuntos
Classificação , Filogenia , Classificação/métodos , Introgressão Genética , Hibridização Genética , Filogeografia/métodos , Simulação por Computador
3.
Mol Biol Evol ; 40(6)2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37216901

RESUMO

When challenged by similar environmental conditions, phylogenetically distant taxa often independently evolve similar traits (convergent evolution). Meanwhile, adaptation to extreme habitats might lead to divergence between taxa that are otherwise closely related. These processes have long existed in the conceptual sphere, yet molecular evidence, especially for woody perennials, is scarce. The karst endemic Platycarya longipes and its only congeneric species, Platycarya strobilacea, which is widely distributed in the mountains in East Asia, provide an ideal model for examining the molecular basis of both convergent evolution and speciation. Using chromosome-level genome assemblies of both species, and whole-genome resequencing data from 207 individuals spanning their entire distribution range, we demonstrate that P. longipes and P. strobilacea form two species-specific clades, which diverged around 2.09 million years ago. We find an excess of genomic regions exhibiting extreme interspecific differentiation, potentially due to long-term selection in P. longipes, likely contributing to the incipient speciation of the genus Platycarya. Interestingly, our results unveil underlying karst adaptation in both copies of the calcium influx channel gene TPC1 in P. longipes. TPC1 has previously been identified as a selective target in certain karst-endemic herbs, indicating a convergent adaptation to high calcium stress among karst-endemic species. Our study reveals the genic convergence of TPC1 among karst endemics and the driving forces underneath the incipient speciation of the two Platycarya lineages.


Assuntos
Carbonato de Cálcio , Juglandaceae , Ásia Oriental , Cálcio , Especiação Genética , Genômica , Juglandaceae/genética , Juglandaceae/fisiologia
4.
Mol Biol Evol ; 40(6): msad121, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37325551

RESUMO

When challenged by similar environmental conditions, phylogenetically distant taxa often independently evolve similar traits (convergent evolution). Meanwhile, adaptation to extreme habitats might lead to divergence between taxa that are otherwise closely related. These processes have long existed in the conceptual sphere, yet molecular evidence, especially for woody perennials, is scarce. The karst endemic Platycarya longipes, and its only congeneric species, P. strobilacea, which is widely distributed in the mountains in East Asia, provide an ideal model for examining the molecular basis of both convergent evolution and speciation. Using chromosome-level genome assemblies of both species, and whole genome resequencing data from 207 individuals spanning their entire distribution range, we demonstrate that P. longipes and P. strobilacea form two species-specific clades, which diverged around 2.09 million years ago. We find an excess of genomic regions exhibiting extreme interspecific differentiation, potentially due to long-term selection in P. longipes, likely contributing to the incipient speciation of the genus Platycarya. Interestingly, our results unveil underlying karst adaptation in both copies of the calcium influx channel gene TPC1 in P. longipes. TPC1 has previously been identified as a selective target in certain karst-endemic herbs, indicating a convergent adaptation to high calcium stress among karst-endemic species. Our study reveals the genic convergence of TPC1 among karst endemics, and the driving forces underneath the incipient speciation of the two Platycarya lineages.


Assuntos
Carbonato de Cálcio , Juglandaceae , Cálcio , Especiação Genética , Genômica
5.
Syst Biol ; 72(1): 35-49, 2023 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35799362

RESUMO

The species studied in any evolutionary investigation generally constitute a small proportion of all the species currently existing or that have gone extinct. It is therefore likely that introgression, which is widespread across the tree of life, involves "ghosts," that is, unsampled, unknown, or extinct lineages. However, the impact of ghost introgression on estimations of species trees has rarely been studied and is poorly understood. Here, we use mathematical analysis and simulations to examine the robustness of species tree methods based on the multispecies coalescent model to introgression from a ghost or extant lineage. We found that many results originally obtained for introgression between extant species can easily be extended to ghost introgression, such as the strongly interactive effects of incomplete lineage sorting (ILS) and introgression on the occurrence of anomalous gene trees. The relative performance of the summary species tree method (ASTRAL) and the full-likelihood method (*BEAST) varies under different introgression scenarios, with the former being more robust to gene flow between nonsister species, whereas the latter performing better under certain conditions of ghost introgression. When an outgroup ghost (defined as a lineage that diverged before the most basal species under investigation) acts as the donor of the introgressed genes, the time of root divergence among the investigated species generally was overestimated, whereas ingroup introgression, as commonly perceived, can only lead to underestimation. In many cases of ingroup introgression that may or may not involve ghost lineages, the stronger the ILS, the higher the accuracy achieved in estimating the time of root divergence, although the topology of the species tree is more prone to be biased by the effect of introgression. [Anomalous gene trees; divergence time; ghost introgression; multispecies coalescent; simulation; species tree.].


Assuntos
Evolução Biológica , Fluxo Gênico , Filogenia , Simulação por Computador , Probabilidade , Modelos Genéticos
6.
BMC Biol ; 21(1): 168, 2023 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-37553642

RESUMO

BACKGROUND: Autopolyploidy is a valuable model for studying whole-genome duplication (WGD) without hybridization, yet little is known about the genomic structural and functional changes that occur in autopolyploids after WGD. Cyclocarya paliurus (Juglandaceae) is a natural diploid-autotetraploid species. We generated an allele-aware autotetraploid genome, a chimeric chromosome-level diploid genome, and whole-genome resequencing data for 106 autotetraploid individuals at an average depth of 60 × per individual, along with 12 diploid individuals at an average depth of 90 × per individual. RESULTS: Autotetraploid C. paliurus had 64 chromosomes clustered into 16 homologous groups, and the majority of homologous chromosomes demonstrated similar chromosome length, gene numbers, and expression. The regions of synteny, structural variation and nonalignment to the diploid genome accounted for 81.3%, 8.8% and 9.9% of the autotetraploid genome, respectively. Our analyses identified 20,626 genes (69.18%) with four alleles and 9191 genes (30.82%) with one, two, or three alleles, suggesting post-polyploid allelic loss. Genes with allelic loss were found to occur more often in proximity to or within structural variations and exhibited a marked overlap with transposable elements. Additionally, such genes showed a reduced tendency to interact with other genes. We also found 102 genes with more than four copies in the autotetraploid genome, and their expression levels were significantly higher than their diploid counterparts. These genes were enriched in enzymes involved in stress response and plant defense, potentially contributing to the evolutionary success of autotetraploids. Our population genomic analyses suggested a single origin of autotetraploids and recent divergence (~ 0.57 Mya) from diploids, with minimal interploidy admixture. CONCLUSIONS: Our results indicate the potential for genomic and functional reorganization, which may contribute to evolutionary success in autotetraploid C. paliurus.


Assuntos
Duplicação Gênica , Tetraploidia , Humanos , Alelos , Poliploidia , Genômica
7.
Mol Biol Evol ; 39(1)2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34687315

RESUMO

Although hybridization plays a large role in speciation, some unknown fraction of hybrid individuals never reproduces, instead remaining as genetic dead-ends. We investigated a morphologically distinct and culturally important Chinese walnut, Juglans hopeiensis, suspected to have arisen from hybridization of Persian walnut (J. regia) with Asian butternuts (J. cathayensis, J. mandshurica, and hybrids between J. cathayensis and J. mandshurica). Based on 151 whole-genome sequences of the relevant taxa, we discovered that all J. hopeiensis individuals are first-generation hybrids, with the time for the onset of gene flow estimated as 370,000 years, implying both strong postzygotic barriers and the presence of J. regia in China by that time. Six inversion regions enriched for genes associated with pollen germination and pollen tube growth may be involved in the postzygotic barriers that prevent sexual reproduction in the hybrids. Despite its long-recurrent origination and distinct traits, J. hopeiensis does not appear on the way to speciation.


Assuntos
Juglans , Fluxo Gênico , Genômica , Humanos , Hibridização Genética , Juglans/genética , Árvores
8.
PLoS Pathog ; 17(3): e1009481, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33788895

RESUMO

TcpC is a virulence factor of uropathogenic E. coli (UPEC). It was found that TIR domain of TcpC impedes TLR signaling by direct association with MyD88. It has been a long-standing question whether bacterial pathogens have evolved a mechanism to manipulate MyD88 degradation by ubiquitin-proteasome pathway. Here, we show that TcpC is a MyD88-targeted E3 ubiquitin ligase. Kidney macrophages from mice with pyelonephritis induced by TcpC-secreting UPEC showed significantly decreased MyD88 protein levels. Recombinant TcpC (rTcpC) dose-dependently inhibited protein but not mRNA levels of MyD88 in macrophages. Moreover, rTcpC significantly promoted MyD88 ubiquitination and accumulation in proteasomes in macrophages. Cys12 and Trp106 in TcpC are crucial amino acids in maintaining its E3 activity. Therefore, TcpC blocks TLR signaling pathway by degradation of MyD88 through ubiquitin-proteasome system. Our findings provide not only a novel biochemical mechanism underlying TcpC-medicated immune evasion, but also the first example that bacterial pathogens inhibit MyD88-mediated signaling pathway by virulence factors that function as E3 ubiquitin ligase.


Assuntos
Proteínas de Escherichia coli/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Transdução de Sinais/fisiologia , Escherichia coli Uropatogênica/patogenicidade , Fatores de Virulência/metabolismo , Animais , Linhagem Celular , Feminino , Humanos , Evasão da Resposta Imune/fisiologia , Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Pielonefrite/imunologia , Pielonefrite/microbiologia , Receptores Toll-Like/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Escherichia coli Uropatogênica/imunologia , Escherichia coli Uropatogênica/metabolismo , Virulência/fisiologia
9.
Am J Bot ; 109(3): 470-485, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35244204

RESUMO

PREMISE: Fecundity and mating outcomes commonly differ among plant populations occupying contrasting environments. If self-pollination occurs primarily among flowers within plants, contrasting reproductive outcomes among populations must reflect environmental effects on plant-pollinator interactions. Specifically, local conditions could affect features of plant phenotypes that influence pollinator behavior, in turn modifying plant reproductive outcomes. METHODS: We compared phenotypes, pollinator abundance and behavior, and female fecundity and mating in two meadow populations and two forest populations of Aconitum kusnezoffii within 3 km of each other. Mating outcomes were assessed using microsatellites. RESULTS: Meadow plants generally produced more, shorter ramets with more, larger flowers, but less nectar per flower than forest plants. These differences likely largely represent phenotypic plasticity. Individual bumble bees visited more flowers on forest plants, likely because the more abundant bees in the meadows depleted nectar availability, as indicated by briefer visits to individual flowers. Despite similar fruit set in both habitats, forest plants set more seeds per fruit. Nevertheless, meadow plants produced more seeds overall, owing to sevenfold greater flower production. Consistent with individual bees visiting fewer flowers on meadow plants, more of their seeds were outcrossed. However, the outcrossed seeds of forest plants included more male mates. CONCLUSIONS: Reproductive outcomes can vary among populations of animal-pollinated plants as a result of differences in the availability of effective pollinators and environmental effects on plant phenotypes, and their functional consequences for pollinator behavior that governs pollen dispersal.


Assuntos
Néctar de Plantas , Polinização , Animais , Abelhas , Fertilidade , Flores , Florestas , Fenótipo , Plantas
10.
New Phytol ; 232(1): 388-403, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34143496

RESUMO

Topological cytonuclear discordance is commonly observed in plant phylogenetic and phylogeographic studies, yet few studies have attempted to detect two other forms of cytonuclear discordance (branch length and geographical) and to uncover the causes of the discordance. We used the whole nuclear and chloroplast genome data from 80 individual Asian butternuts to reveal the pattern and processes of cytonuclear discordance. Our findings indicate that the chloroplast genome had substantially deeper divergence (branch-length discordance) and a steeper cline in the contact zone (geographic discordance) compared with the nuclear genome. After various hypothesis have been tested, the results suggest that incomplete lineage sorting, positive selection and cytonuclear incompatibility are probably insufficient to explain this pattern. However, isolation-by-distance analysis and gene flow estimation point to a much higher level of gene flow by pollen compared with by seeds, which may have slowed down lineage divergence and mediated wider contact for nuclear genome compared with the chloroplast genome. Altogether, this study highlights a critical role of sex-biased dispersal in causing discordance between the nuclear and plastid genome of Asian butternuts. Given its ubiquity among plants, asymmetric gene flow should be given a high priority in future studies of cytonuclear discordance.


Assuntos
Fluxo Gênico , Genoma de Cloroplastos , Núcleo Celular/genética , Filogenia , Pólen/genética , Sementes/genética
11.
Mol Phylogenet Evol ; 154: 106964, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32956798

RESUMO

Hybridization has played an important role in plant evolution. Less attention has been paid, however, to its role in dispersal. In this study, historical divergence and hybridization were investigated in two closely related Chinese oaks, Quercus mongolica and Q. liaotungensis, to estimate the role that hybridization played in their dispersal. We genotyped 27 Q. mongolica and Q. liaotungensis populations throughout the distributional range of the two oak species, using 14 single-copy nuclear genes and four noncoding chloroplast DNA regions. Bayesian cluster and population tree analyses indicated that there were three groups over all oak populations, namely, Q. mongolica, northwest-northern China (NW-NC) Q. liaotungensis, and northeastern China (NEC) Q. liaotungensis. Approximate Bayesian computation simulation supported an asymmetrical hybridization origin of NEC Q. liaotungensis, after a previous divergence between NW-NC Q. liaotungensis and Q. mongolica. IMa3 analyses suggested that Q. liaotungensis and Q. mongolica diverged in the NW-NC and NEC regions, respectively, and that NEC Q. liaotungensis arose from Q. mongolica, not from NW-NC Q. liaotungensis, and was greatly introgressed by NW-NC Q. liaotungensis. Oak populations in NW-NC and NEC regions held different chloroplast DNA haplotypes, and Q. liaotungensis in NEC shared most haplotypes with Q. mongolica populations, but none with NW-NC Q. liaotungensis populations, suggesting the maternal origin of NEC Q. liaotungensis from Q. mongolica. This study found clear signals of isolation divergence of Q. liaotungensis in NW-NC and Q. mongolica in NEC, and the results suggest that asymmetrical hybridization and introgression from Q. liaotungensis to Q. mongolica, mostly likely via pollen flow, facilitated Q. liaotungensis dispersal to NEC.


Assuntos
Hibridização Genética , Quercus/genética , Dispersão de Sementes/genética , Teorema de Bayes , China , Cloroplastos/genética , DNA de Cloroplastos/genética , Fluxo Gênico , Variação Genética , Geografia , Haplótipos/genética , Funções Verossimilhança , Filogenia , Probabilidade , Tamanho da Amostra
12.
Nanotechnology ; 32(13): 135204, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33285531

RESUMO

We investigated the influence of the flake thickness for molybdenum disulfide (MoS2) field effect transistors on the effect of a 150 keV high-energy proton beam applied on these devices. The electrical characteristics of the devices with channel thicknesses ranging from monolayer to bulk were measured before and after proton irradiation with a proton fluence of 5 × 1014 cm-2. The subthreshold swing (SS), threshold voltage shift and electron mobility were extracted with the Y-function method after proton irradiation and significant degradation were observed. It is found that, with the increase of layer thickness, mobility degradation and threshold voltage shift both eased, but the SS degradation was insensitive to the MoS2 flake thickness increase. We also demonstrate that the threshold voltage shift is dominated by oxide charges; however, the mobility and SS degradations are mainly affected by the interface traps. Our study will enhance the understanding of the influence of high-energy particles on MoS2-based nano-electronic devices. By increasing the MoS2 flake thickness to a certain extent, one can hopefully find a balance between effectively resisting [Formula: see text] shift and achieving high mobility and small SS degradation.

13.
Nanotechnology ; 32(31)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33882479

RESUMO

Contact resistance (RC) is of great importance for radio frequency (RF) applications of graphene, especially graphene field effect transistors (FETs) with short channel. FETs and transmission line model test structures based on chemical vapor deposition grown graphene are fabricated. The effects of employing traditional lithography solvent (Acetone) and strong solvents for photo resist, such as N, N-Dimethylacetamide (ZDMAC) and N-Methyl pyrrolidone (NMP), are systematically investigated. It was found that ZDMAC and NMP have more proficiency than acetone to remove the photo-resist residues and contaminations attached on graphene surface, enabling clean surface of graphene. However, strong solvents are found to destroy the lattice structure of graphene channel and induce defects in graphene lattice. Clean surface contributes to a significant reduction in theRCbetween graphene channel and metal electrode, and the defects introduced on graphene surface underneath metal electrodes also contribute the reduction ofRC. But defects and deformation of lattice will increase the resistance in graphene channel and lead to the compromise of device performance. To address this problem, a mix wet-chemical approach employing both acetone and ZDMAC was developed in our study to realize a 19.07% reduction ofRC, without an unacceptable mass production of defects.

14.
Nanotechnology ; 32(15): 155705, 2021 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-33511964

RESUMO

Recently, graphene has led to unprecedented progress in device performance at the atom limit. A high performance of field-effect transistors requires a low graphene-metal contact resistance. However, the chemical doping methods used to tailor or improve the properties of graphene are sensitive to ambient conditions. Here, we fabricate a single-layer perfluorinated polymeric sulfonic acid (PFSA), also known as Nafion, between the graphene and the substrate as a p-type dopant. The PFSA doping method, without inducing any additional structural defects, reduces the contact resistance of graphene by ∼28.8%, which has a significant impact on practical applications. This reduction can be maintained for at least 67 days due to the extreme stability of PFSA. Effective, uniform and stable, the PFSA doping method provides an efficient way to reduce the contact resistance of graphene applications.

15.
Clin Exp Pharmacol Physiol ; 48(9): 1185-1202, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34046925

RESUMO

Cancer stem cells (CSCs) are a small population of heterogeneous tumor cells with the capacity of self-renewal and aberrant differentiation for immortality and divergent lineages of cancer cells. In contrast to bulky tumor cells, CSCs remain less differentiated and resistant to therapy even when targeted with tissue-specific antigenic markers. This makes CSCs responsible for not only tumor initiation, development, but also tumor recurrence. Emerging evidence suggests that CSCs can undergo cell senescence, a non-proliferative state of cells in response to stress. While cell senescence attenuates tumor cell proliferation, it is commonly regarded as a tumor suppressive mechanism. However, mounting research indicates that CSC senescence also provides these cells with the capacity to evade cytotoxic effects from cancer therapy, exacerbating cancer relapse and metastasis. Recent studies demonstrate that senescence drives reprogramming of cancer cell toward stemness and promotes CSC generation. In this review, we highlight the origin, heterogeneity and senescence regulatory mechanisms of CSCs, the complex relationship between CSC senescence and tumor therapy, and the recent beneficial effects of senotherapy on eliminating senescent tumor cells.


Assuntos
Células-Tronco Neoplásicas
16.
Mol Biol Evol ; 36(11): 2451-2461, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31163451

RESUMO

Persian walnut (Juglans regia) is cultivated worldwide for its high-quality wood and nuts, but its origin has remained mysterious because in phylogenies it occupies an unresolved position between American black walnuts and Asian butternuts. Equally unclear is the origin of the only American butternut, J. cinerea. We resequenced the whole genome of 80 individuals from 19 of the 22 species of Juglans and assembled the genome of its relatives Pterocarya stenoptera and Platycarya strobilacea. Using phylogenetic-network analysis of single-copy nuclear genes, genome-wide site pattern probabilities, and Approximate Bayesian Computation, we discovered that J. regia (and its landrace J. sigillata) arose as a hybrid between the American and the Asian lineages and that J. cinerea resulted from massive introgression from an immigrating Asian butternut into the genome of an American black walnut. Approximate Bayesian Computation modeling placed the hybrid origin in the late Pliocene, ∼3.45 My, with both parental lineages since having gone extinct in Europe.

17.
J Evol Biol ; 2020 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424908

RESUMO

Temperature determines the rates of all biochemical and biophysical processes, and is also believed to be a key driver of macroevolutionary patterns. It is suggested that physiological constraints at low temperatures may diminish the fitness advantages of otherwise beneficial mutations; by contrast, relatively high, benign, temperatures allow beneficial mutations to efficiently show their phenotypic effects. To experimentally test this "mutational effects" mechanism, we examined the fitness effects of mutations across a temperature gradient using bacterial genotypes from the early stage of a mutation accumulation experiment with Escherichia coli. While the incidence of beneficial mutations did not significantly change across environmental temperatures, the number of mutations that conferred strong beneficial fitness effects was greater at higher temperatures. The results therefore support the hypothesis that warmer temperatures increase the chance and magnitude of positive selection, with implications for explaining the geographic patterns in evolutionary rates and understanding contemporary evolution under global warming.

18.
Bioorg Chem ; 98: 103720, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32171982

RESUMO

Selective JAK3 inhibitors have been shown to have a potential benefit in the treatment of autoimmune disorders. Here we report the identification of a series of pyrazolopyrimidine derivatives as potent JAK3 inhibitors that exploit a unique cysteine (Cys909) residue in JAK3. Most of these compounds (13k, 13n and 13 t), displayed stronger anti-JAK3 kinase activity and selectivity than tofacitinib. Furthermore, the most active inhibitor 13t (IC50 = 0.1 nM), also exhibited favourable selectivity for JAK3 in a panel of 9 kinases which contain the same cysteine. In a series of cytokinestimulated cellular analysis, compound 13 t, could potently block the JAK3-STAT signaling pathway. Further biological studies, including cellular antiproliferative activity assays and a rat adjuvant-induced arthritis model for in vivo evaluation, also indicated its efficacy and low toxicity in the treatment of rheumatoid arthritis. The results of these experimental explorations suggested that 13t is a promising lead compound for the development of selective JAK3 inhibitor with therapeutic potential in rheumatoid arthritis.


Assuntos
Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Janus Quinase 3/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Animais , Artrite Experimental/metabolismo , Artrite Reumatoide/metabolismo , Relação Dose-Resposta a Droga , Humanos , Janus Quinase 3/metabolismo , Masculino , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirazóis/síntese química , Pirazóis/química , Pirimidinas/síntese química , Pirimidinas/química , Ratos , Ratos Endogâmicos Lew , Relação Estrutura-Atividade , Células THP-1
19.
Acta Pharmacol Sin ; 41(4): 523-534, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32203085

RESUMO

Ginsenoside Rg1 is one of the most active ingredients in ginseng, which has been reported to protect dopaminergic neurons and improve behavioral defects in MPTP model, 6-OHDA model and rotenone model. However, it is unclear whether Rg1 exerted neuroprotection in LPS-induced sub-acute PD model. In this study, we investigated the neuroprotective effect of Rg1 in the sub-acute PD mouse model and explored the related mechanisms. Rg1 (10, 20, 40 mg·kg-1·d-1) was orally administered to mice for 18 days. A sub-acute PD model was established in the mice through LPS microinjection into the substantia nigra (SN) from D8 to D13. We found that Rg1 administration dose-dependently inhibited LPS-induced damage of dopaminergic neurons and activation of glial cells in the substantia nigra pars compacta (SNpc). The neuroprotective effects of Rg1 were associated with the reduction of pro-inflammatory cytokines and the improvement of anti-inflammatory cytokines and neurotrophin in the midbrain. Rg1 shifted the polarization of microglia towards the M2 phenotype from M1, evidenced by decreased M1 markers (inducible NO synthase, CD16, etc.) and increased M2 markers (arginase 1 (Arg1), CD206, etc) in the midbrain. Furthermore, Rg1 administration markedly inhibited nuclear translocation of NF-κB in midbrain microglia. In conclusion, Rg1 protects PD mice induced by continuous LPS injection by inhibiting the nuclear entry of NF-κB and regulating the polarization balance of microglia, shedding new light on a disease-modifying therapy of PD.


Assuntos
Ginsenosídeos/farmacologia , Microglia/efeitos dos fármacos , NF-kappa B/antagonistas & inibidores , Fármacos Neuroprotetores/farmacologia , Transtornos Parkinsonianos/tratamento farmacológico , Administração Oral , Animais , Araliaceae/química , Citocinas/antagonistas & inibidores , Citocinas/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ginsenosídeos/administração & dosagem , Ginsenosídeos/isolamento & purificação , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , NF-kappa B/metabolismo , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/isolamento & purificação , Transtornos Parkinsonianos/induzido quimicamente , Fenótipo , Transdução de Sinais/efeitos dos fármacos
20.
Zhongguo Zhong Yao Za Zhi ; 45(6): 1304-1310, 2020 Mar.
Artigo em Zh | MEDLINE | ID: mdl-32281340

RESUMO

In the clinical practice of traditional Chinese medicine, Pinelliae Rhizoma is a commonly used traditional Chinese medicinal material, with a very important medicinal value, but its raw products have certain toxicity. According to the basic theory of traditional Chinese medicine, after Pinelliae Rhizoma is processed, its toxic and side effects can be reduced, there by ensuring its medication safety in clinic. Based on the processing characteristics of Pinelliae Rhizoma replication method, this article discusses the changes before and after processing of Pinelliae Rhizoma with multiple materials and multiple processes. This method does not have a unified process. One or more materials are added, and various processes, such as dipping, soaking, bleaching, or steaming, cooking or combined methods are adopted. Then, Pinelliae Rhizoma is repeatedly processed to meet the specified quality requirements. By different processing methods, the efficacy changes accordingly, and Pinelliae Rhizoma can be used for the treatment of different diseases. The article starts in the two directions of multi-materials and multi-processes, and summarizes the effects of multi-materials or multi-processes on the chemical composition and efficacy, as well as the processing mechanism of reducing toxicity and increasing efficiency, in the expectation of reducing the toxicity and enhancing the efficacy of Pinelliae Rhizoma. The medicinal scope provides a reference and theoretical basis for further studies on the processing mechanism. An in-depth study is conducted to make Pinelliae Rhizoma more safe and effective in clinic application, and ensure its clinical efficacy. It will provide reference for future studies on quality control, active ingredients and new drug development of the processing of pinellia slices. It has laid a scientific foundation for exploring the best processing techno-logy, and provided a theoretical basis for solving the production problems of processed Pinelliae Rhizoma products, so as to improve the production efficiency and the quality of medicines.


Assuntos
Medicamentos de Ervas Chinesas/química , Pinellia/química , Rizoma/química , Tecnologia Farmacêutica , Medicina Tradicional Chinesa
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