RESUMO
Increased blood lipid levels are heritable risk factors of cardiovascular disease with varied prevalence worldwide owing to different dietary patterns and medication use1. Despite advances in prevention and treatment, in particular through reducing low-density lipoprotein cholesterol levels2, heart disease remains the leading cause of death worldwide3. Genome-wideassociation studies (GWAS) of blood lipid levels have led to important biological and clinical insights, as well as new drug targets, for cardiovascular disease. However, most previous GWAS4-23 have been conducted in European ancestry populations and may have missed genetic variants that contribute to lipid-level variation in other ancestry groups. These include differences in allele frequencies, effect sizes and linkage-disequilibrium patterns24. Here we conduct a multi-ancestry, genome-wide genetic discovery meta-analysis of lipid levels in approximately 1.65 million individuals, including 350,000 of non-European ancestries. We quantify the gain in studying non-European ancestries and provide evidence to support the expansion of recruitment of additional ancestries, even with relatively small sample sizes. We find that increasing diversity rather than studying additional individuals of European ancestry results in substantial improvements in fine-mapping functional variants and portability of polygenic prediction (evaluated in approximately 295,000 individuals from 7 ancestry groupings). Modest gains in the number of discovered loci and ancestry-specific variants were also achieved. As GWAS expand emphasis beyond the identification of genes and fundamental biology towards the use of genetic variants for preventive and precision medicine25, we anticipate that increased diversity of participants will lead to more accurate and equitable26 application of polygenic scores in clinical practice.
Assuntos
Doenças Cardiovasculares , Estudo de Associação Genômica Ampla , Doenças Cardiovasculares/genética , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla/métodos , Humanos , Desequilíbrio de Ligação , Herança Multifatorial , Polimorfismo de Nucleotídeo Único/genética , Grupos PopulacionaisRESUMO
Meta-analyses of genome-wide association studies (GWAS) have identified more than 240 loci that are associated with type 2 diabetes (T2D)1,2; however, most of these loci have been identified in analyses of individuals with European ancestry. Here, to examine T2D risk in East Asian individuals, we carried out a meta-analysis of GWAS data from 77,418 individuals with T2D and 356,122 healthy control individuals. In the main analysis, we identified 301 distinct association signals at 183 loci, and across T2D association models with and without consideration of body mass index and sex, we identified 61 loci that are newly implicated in predisposition to T2D. Common variants associated with T2D in both East Asian and European populations exhibited strongly correlated effect sizes. Previously undescribed associations include signals in or near GDAP1, PTF1A, SIX3, ALDH2, a microRNA cluster, and genes that affect the differentiation of muscle and adipose cells3. At another locus, expression quantitative trait loci at two overlapping T2D signals affect two genes-NKX6-3 and ANK1-in different tissues4-6. Association studies in diverse populations identify additional loci and elucidate disease-associated genes, biology, and pathways.
Assuntos
Povo Asiático/genética , Diabetes Mellitus Tipo 2/genética , Predisposição Genética para Doença , Aldeído-Desidrogenase Mitocondrial/genética , Alelos , Anquirinas/genética , Índice de Massa Corporal , Estudos de Casos e Controles , Europa (Continente)/etnologia , Proteínas do Olho/genética , Ásia Oriental/etnologia , Feminino , Estudo de Associação Genômica Ampla , Proteínas de Homeodomínio/genética , Humanos , Masculino , Proteínas do Tecido Nervoso/genética , RNA Mensageiro/análise , Fatores de Transcrição/genética , Transcrição Gênica , Proteína Homeobox SIX3RESUMO
A major challenge of genome-wide association studies (GWASs) is to translate phenotypic associations into biological insights. Here, we integrate a large GWAS on blood lipids involving 1.6 million individuals from five ancestries with a wide array of functional genomic datasets to discover regulatory mechanisms underlying lipid associations. We first prioritize lipid-associated genes with expression quantitative trait locus (eQTL) colocalizations and then add chromatin interaction data to narrow the search for functional genes. Polygenic enrichment analysis across 697 annotations from a host of tissues and cell types confirms the central role of the liver in lipid levels and highlights the selective enrichment of adipose-specific chromatin marks in high-density lipoprotein cholesterol and triglycerides. Overlapping transcription factor (TF) binding sites with lipid-associated loci identifies TFs relevant in lipid biology. In addition, we present an integrative framework to prioritize causal variants at GWAS loci, producing a comprehensive list of candidate causal genes and variants with multiple layers of functional evidence. We highlight two of the prioritized genes, CREBRF and RRBP1, which show convergent evidence across functional datasets supporting their roles in lipid biology.
Assuntos
Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Cromatina/genética , Genômica , Humanos , Lipídeos/genética , Polimorfismo de Nucleotídeo Único/genéticaRESUMO
Protein-coding genetic variants that strongly affect disease risk can yield relevant clues to disease pathogenesis. Here we report exome-sequencing analyses of 20,791 individuals with type 2 diabetes (T2D) and 24,440 non-diabetic control participants from 5 ancestries. We identify gene-level associations of rare variants (with minor allele frequencies of less than 0.5%) in 4 genes at exome-wide significance, including a series of more than 30 SLC30A8 alleles that conveys protection against T2D, and in 12 gene sets, including those corresponding to T2D drug targets (P = 6.1 × 10-3) and candidate genes from knockout mice (P = 5.2 × 10-3). Within our study, the strongest T2D gene-level signals for rare variants explain at most 25% of the heritability of the strongest common single-variant signals, and the gene-level effect sizes of the rare variants that we observed in established T2D drug targets will require 75,000-185,000 sequenced cases to achieve exome-wide significance. We propose a method to interpret these modest rare-variant associations and to incorporate these associations into future target or gene prioritization efforts.
Assuntos
Diabetes Mellitus Tipo 2/genética , Sequenciamento do Exoma , Exoma/genética , Animais , Estudos de Casos e Controles , Técnicas de Apoio para a Decisão , Feminino , Frequência do Gene , Estudo de Associação Genômica Ampla , Humanos , Masculino , Camundongos , Camundongos KnockoutRESUMO
Although interest in stabilized α-helical peptides as next-generation therapeutics for modulating biomolecular interfaces is increasing, peptides have limited functionality and stability due to their small size. In comparison, α-helical ligands based on proteins can make steric clash with targets due to their large size. Here, we report the design of a monomeric pseudo-isolated α-helix (mPIH) system in which proteins behave as if they are peptides. The designed proteins contain α-helix ligands that do not require any covalent chemical modification, do not have frayed ends, and importantly can make sterically favorable interactions similar to isolated peptides. An optimal mPIH showed a more than 100-fold increase in target selectivity, which might be related to the advantages in conformational selection due to the absence of frayed ends. The α-helical ligand in the mPIH displayed high thermal stability well above human body temperature and showed reversible and rapid folding/unfolding transitions. Thus, mPIH can become a promising protein-based platform for developing stabilized α-helix pharmaceuticals.
Assuntos
Peptídeos , Proteínas , Sequência de Aminoácidos , Dicroísmo Circular , Humanos , Peptídeos/química , Conformação Proteica em alfa-Hélice , Dobramento de Proteína , Estrutura Secundária de ProteínaRESUMO
Chrysin is a flavonoid found abundantly in substances, such as honey and phytochemicals, and is known to exhibit anticancer effects against various cancer cells. Nevertheless, the anticancer effect of chrysin against oral cancer has not yet been verified. Furthermore, the mechanism underlying autophagy is yet to be clearly elucidated. Thus, this study investigated chrysin-mediated apoptosis and autophagy in human mucoepidermoid carcinoma (MC-3) cells. The change in MC-3 cell viability was examined using a 3-(4,5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide cell viability assay, as well as 40,6-diamidino-2-phenylindole, annexin V, and propidium iodide staining. Western blotting was used to analyze the proteins related to apoptosis and the mitogen-activated protein kinase (MAPK) pathway. In addition, the presence or absence of autophagy and changes in the expression of related proteins were investigated using acridine orange staining and Western blot. The results suggested that chrysin induced apoptosis and autophagy in MC-3 oral cancer cells via the MAPK/extracellular signal-regulated kinase pathway. Moreover, the induced autophagy exerted a cytoprotective effect against apoptosis. Thus, the further reduced cell viability due to autophagy as well as apoptosis induction highlight therapeutic potential of chrysin for oral cancer.
Assuntos
Apoptose , Neoplasias Bucais , Humanos , Serina-Treonina Quinases TOR/metabolismo , Flavonoides/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Autofagia , Linhagem Celular Tumoral , Neoplasias Bucais/tratamento farmacológicoRESUMO
We constructed an age-to-age infection matrix to characterize the household transmission pattern of coronavirus disease 2019 (COVID-19) in Korea. Among 4,048 household clusters, within-age group infection dominated the overall household transmissions. Transmission of severe acute respiratory syndrome coronavirus 2 was more common from adults to children than from children to adults.
Assuntos
COVID-19/transmissão , SARS-CoV-2 , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Características da Família , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Adulto JovemRESUMO
Lipid levels in blood are widely used to diagnose and monitor chronic diseases. It is essential to identify the genetic traits involved in lipid metabolism for understanding chronic diseases. However, the influence of genetic traits varies depending on race, sex, age, and ethnicity. Therefore, research focusing on populations of individual countries is required, and the results can be used as a basis for comparison of results of other studies at the cross-racial and cross-country levels. In the present study, we selected lipid-related variants and evaluated their effects on lipid-related diseases in more than 14,000 subjects of three cohorts using the Illumina Human Exome Beadchip. A genome-wide association study was conducted using EPACTs after adjusting for age, sex, and recruitment area. A genome-wide significance cutoff was defined as p < 5E-08 in all the three cohorts. Sixteen variants represented the lipid traits and were classified as vulnerable to borderline hypertriglyceridemia, hyper-LDL-cholesterolemia, or hypo-HDL-cholesterolemia. Moreover, we compared the genetic effects of the 16 variants between ethnic groups and identified the missense variants in apolipoprotein A-V, cholesterol ester transfer protein, and apolipoprotein E as Asian-specific. Our study provides candidate genes as markers for chronic diseases through the evaluation of genetic effects.
Assuntos
Etnicidade/genética , Exoma , Estudo de Associação Genômica Ampla , Hiperlipidemias/etnologia , Hiperlipidemias/genética , Lipídeos/análise , Polimorfismo de Nucleotídeo Único , Povo Asiático/genética , Etnicidade/classificação , Etnicidade/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , República da CoreiaRESUMO
A screening of Sudanese medicinal plants for antiprotozoal activities revealed that the chloroform and water fractions of the ethanolic root extract of Haplophyllum tuberculatum exhibited appreciable bioactivity against Leishmania donovani. The antileishmanial activity was tracked by HPLC-based activity profiling, and eight compounds were isolated from the chloroform fraction. These included lignans tetrahydrofuroguaiacin B (1), nectandrin B (2), furoguaiaoxidin (7), and 3,3'-dimethoxy-4,4'-dihydroxylignan-9-ol (10), and four cinnamoylphenethyl amides, namely dihydro-feruloyltyramine (5), (E)-N-feruloyltyramine (6), N,N'-diferuloylputrescine (8), and 7'-ethoxy-feruloyltyramine (9). The water fraction yielded steroid saponins 11-13. Compounds 1, 2, and 5-13 are reported for the first time from Haplophyllum species and the family Rutaceae. The antiprotozoal activity of the compounds plus two stereoisomeric tetrahydrofuran lignans-fragransin B2 (3) and fragransin B1 (4)-was determined against Leishmania donovani amastigotes, Plasmodium falciparum, and Trypanosoma brucei rhodesiense bloodstream forms, along with their cytotoxicity to rat myoblast L6 cells. Nectandrin B (2) exhibited the highest activity against L. donovani (IC50 4.5 µM) and the highest selectivity index (25.5).
Assuntos
Antimaláricos/farmacologia , Leishmania donovani/crescimento & desenvolvimento , Plasmodium falciparum/crescimento & desenvolvimento , Rutaceae/química , Tripanossomicidas/farmacologia , Trypanosoma brucei rhodesiense/crescimento & desenvolvimento , Amidas/química , Amidas/farmacologia , Animais , Antimaláricos/química , Lignanas/química , Lignanas/farmacologia , Ratos , Saponinas/química , Saponinas/farmacologia , Tripanossomicidas/químicaRESUMO
The major class of bioactive metabolites in Gymnema sylvestre, a popular Ayurvedic medicinal plant for the treatment of diabetes mellitus, is oleanane triterpenoids. In this study, a targeted, biosynthesis-inspired approach using UHPLC-qTOF/MS was implemented to elucidate the whole chemical profile of this plant for the standardization of the Vietnamese G. sylvestre variety. The known compounds were first determined to identify the building blocks of the biosynthetic intermediates and the construction rules for synthesizing oleanane triterpenoids in the plant. These blocks were recombined to build a virtual library of all reasonable compounds consistent with the deduced construction rules. Various techniques, including relative mass defect filtering, multiple key ion analysis, mass fragmentation analysis, and comparison with standard references, were applied to determine the presence of these predicted compounds. Conventional isolation and structure elucidation of six of the new compounds were carried out to identify the new building blocks and validate the assignments. Consequently, 119 peaks were quickly assigned to oleanane triterpenoids, and among them, 77 peaks were predicted to be new compounds based on their molecular formulas and mass fragmentation patterns. All the identified metabolites were then classified into different layers to analyze their logical relationships, and a multilayered chemical profile of the oleanane triterpenoids was constructed. This new approach is expected to be practical for characterizing structures of modular secondary metabolites, such as triterpenoid saponins, and for proposing biosynthetic relationships among compounds of the same class of metabolites in medicinal plants.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Gymnema sylvestre/metabolismo , Ácido Oleanólico/análogos & derivados , Análise Espectral/métodos , Triterpenos/metabolismo , Glicosídeos/metabolismo , Estrutura Molecular , Ácido Oleanólico/química , Ácido Oleanólico/metabolismo , Triterpenos/químicaRESUMO
Although there has been substantial advancement in the development of nanostructures, the development of self-assembled nanostructures that can selectively recognize multivalent targets has been very difficult. Here we show the proof of concept that topology-controlled peptide nanoassemblies can selectively recognize and detect a multivalent RNA target. We compared the differential behaviors of peptides in a linear or cyclic topology in terms of peptide-gold nanoparticle hybrid nanostructure formation, conformational stabilization, monovalent and multivalent RNA binding in vitro, and multivalent RNA recognition in live cells. When the topology-dependent selectivity amplification of the cyclic peptide hybrids is combined with the noninvasive nature of dark-field microscopy, the cellular localization of the viral Rev response element (RRE) RNA can be monitored in situ. Because intracellular interactions are often mediated by overlapping binding partners with weak affinity, the topology-controlled peptide assemblies can provide a versatile means to convert weak ligands into multivalent ligands with high affinity and selectivity.
Assuntos
Nanoestruturas , Peptídeos Cíclicos/química , RNA/química , Microscopia Eletrônica de TransmissãoRESUMO
BACKGROUND: The genetic contribution to complex diseases or traits, including cardio-metabolic traits, has been elucidated recently by large-scale genome-wide association studies. These genome-wide association studies have indicated that most pleiotropic loci contain genes associated with lipids. Clinically, lipid related abnormalities are strongly associated with other diseases such as type 2 diabetes, coronary artery disease and hypertension. The aim of this study was to evaluate the shared genetic background of lipids and other cardio-metabolic traits. METHODS: We conducted meta-analyses of the association between 157 published lipid-associated loci and 10 cardio-metabolic traits in 14,028 Korean individuals genotyped using the Exome chip (Illumina HumanExome BeadChip). We also examined whether the pleiotropic effects of such loci constituted independent (i.e., biological) pleiotropy or mediated pleiotropy in these metabolic pathways. RESULTS: Eighteen lipid-associated loci were significantly associated with one of six cardio-metabolic traits after correction for multiple testing (P < 3.70 × 10(-4)). Region 12q24.12 had pleiotropic effects on fasting plasma glucose, blood pressure and obesity-related traits (body mass index and waist-hip ratio) independent of its effects on the lipid profile. Lipid risk scores, calculated according to whether or not subjects carried the risk allele for lipid traits, were significantly associated with fasting plasma glucose, blood pressure and obesity-related traits. CONCLUSIONS: The 12q24.12 region showed ethnic-specific genetic pleiotropy among cardio-metabolic traits in this study. Our findings may help to account for molecular mechanisms based on shared genetic background underlying not only dyslipidemia, but also cardiovascular disease and type 2 diabetes.
Assuntos
Povo Asiático/genética , Cromossomos Humanos Par 12 , Loci Gênicos , Pleiotropia Genética , Síndrome Metabólica/genética , Biomarcadores/sangue , Glicemia/genética , Pressão Sanguínea/genética , Índice de Massa Corporal , Bases de Dados de Proteínas , Perfilação da Expressão Gênica/métodos , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Lipídeos/sangue , Lipídeos/genética , Síndrome Metabólica/sangue , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/etnologia , Análise de Sequência com Séries de Oligonucleotídeos , Fenótipo , Polimorfismo de Nucleotídeo Único , Mapeamento de Interação de Proteínas , República da Coreia , Relação Cintura-QuadrilRESUMO
BACKGROUND: To investigate whether preeclampsia is independently associated with risk of future metabolic syndrome and whether any such primary associations are modified by different ages at first pregnancy. METHODS: Based on the Health Examinees Study, a cross-sectional analysis was conducted. Data of women (n = 49 780) who had experienced at least 1 pregnancy during their lifetime and had never been diagnosed with any metabolic disorder before their pregnancy were analyzed using multiple logistic regression models. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated after adjusting for age, lifestyle characteristics, and reproductive factors. A stratified analysis was also conducted to estimate the extent of the primary association between preeclampsia and future metabolic syndrome by age at first pregnancy. RESULTS: Women with a history of preeclampsia had significantly increased odds of developing metabolic syndrome (adjusted OR 1.23; 95% CI, 1.12-1.35), central obesity (adjusted OR 1.36; 95% CI, 1.25-1.47), elevated blood pressure (adjusted OR 1.53; 95% CI, 1.41-1.67), or elevated fasting glucose (adjusted OR 1.13; 95% CI, 1.03-1.25) in later life. In the stratified analysis, women who first became pregnant at ages >35 years and had preeclampsia were found to be at significantly increased likelihood of metabolic syndrome later in life (adjusted OR 4.38; 95% CI, 1.62-11.9). CONCLUSIONS: Our findings suggest that preeclampsia increases the risk of metabolic syndrome in later life, and late age at first pregnancy can further exacerbate this risk.
Assuntos
Síndrome Metabólica/epidemiologia , Pré-Eclâmpsia/epidemiologia , Adulto , Idoso , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Idade Materna , Pessoa de Meia-Idade , Gravidez , República da Coreia/epidemiologia , RiscoRESUMO
Here, we report on a ratiometric fluorescence biosensor based on self-assembled peptide nanostructures (SPN), which can respond to conformational changes induced by RNA ligand binding. The design of the SPN biosensor was inspired by the conformational stabilization and multimerization behaviors of the HIV-1 Rev protein induced by cooperative protein-protein and protein-RNA interactions. Because conformation-sensitive SPN biosensors can orchestrate binding and signal transduction events, they can be developed as highly sophisticated and smart nanomaterials for biosensing.
Assuntos
Corantes Fluorescentes/química , Nanopartículas/química , Peptídeos/química , RNA Fúngico/química , Produtos do Gene rev do Vírus da Imunodeficiência Humana/química , Técnicas Biossensoriais , Ligação Proteica , Multimerização Proteica , Estabilidade Proteica , Espectrometria de Fluorescência , Difração de Raios XRESUMO
The glutamine-histidine-glycine-valine (QHGV), a peptide derived from oysters, exhibits antioxidant activity and is being actively researched as a potential pharmaceutical and functional cosmetic ingredient. In this study, we synthesized the QHGV peptide and explored the hitherto unknown anti-inflammatory effects of QHGV. The antioxidant property was also characterized by conjugating with various naturally derived phenolic acids, such as caffeic, gallic, ferulic, sinapinic, and vanillic acids. Conjugation with phenolic acids not only enhanced the antioxidant activity of QHGV but also diminished the lipopolysaccharide-induced generation of reactive oxygen species (ROS) in the murine macrophage cell line, RAW 264.7. The reduction in the levels of reactive oxygen species led to the reduced mRNA expression of inducible nitric oxide synthase (iNos) and cyclooxygenase 2 (Cox-2), resulting in an anti-inflammatory effect through the inhibition of the phosphorylation of mitogen-activated protein kinase, including extracellular signal-activated protein kinase, c-Jun NH2-terminal kinase, and p38. Furthermore, the phenolic acid-conjugated peptides increased the mRNA and protein levels of collagen type I, indicative of a wrinkle-improvement effect. The phenolic acid conjugates of the peptide were not cytotoxic to human keratinocytes such as HaCaT cells. These results suggest that phenolic acid conjugation can enhance the potential of peptides as drug and cosmetic resources.
RESUMO
Gastric cancer is the fifth most common cancer globally and the third leading cause of cancer-related mortality. Existing treatment strategies for gastric cancer often present numerous side effects. Consequently, recent studies have shifted toward devising new treatments grounded in safer natural substances. α-Pinene, a natural terpene found in the essential oils of various plants, such as Lavender angustifolia and Satureja myrtifolia, displays antioxidant, antibiotic, and anticancer properties. Yet, its impact on gastric cancer remains unexplored. This research assessed the effects of α-pinene in vitro using a human gastric adenocarcinoma cell-line (AGS) human gastric cancer cells and in vivo via a xenograft mouse model. The survival rate of AGS cells treated with α-pinene was notably lower than that of the control group, as revealed by the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay. This decline in cell viability was linked to apoptosis, as verified by 4',6-diamidino-2-phenylindole and annexin V/propidium iodide staining. The α-pinene-treated group exhibited elevated cleaved-poly (ADP-ribose) polymerase and B cell lymphoma 2 (Bcl-2)-associated X (Bax) levels and reduced Bcl-2 levels compared with the control levels. Moreover, α-pinene triggered the activation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 within the mitogen-activated protein kinase (MAPK) pathway. In the xenograft mouse model, α-pinene induced apoptosis through the MAPK pathway, devoid of toxicity. These findings position α-pinene as a promising natural therapeutic for gastric cancer.
Assuntos
Monoterpenos Bicíclicos , Neoplasias Gástricas , Humanos , Animais , Camundongos , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Linhagem Celular Tumoral , Apoptose , MAP Quinases Reguladas por Sinal Extracelular , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proliferação de CélulasRESUMO
This study sought to determine the anticancer effect of kaempferol, a glycone-type flavonoid glycoside with various pharmacological benefits, on human oral cancer MC-3 cells. In vitro studies comprised a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, annexin V and propidium iodide staining, western blotting analysis, and acridine orange staining, while the in vivo studies entailed a xenograft model, hematoxylin and eosin staining, and TdT-mediated dUTP-biotin nick end labelling. In vitro, kaempferol reduced the rate of survival of MC-3 cells, mediated intrinsic apoptosis, increased the number of acidic vesicular organelles, and altered the expression of autophagy-related proteins. Further, treatment with the autophagy inhibitors revealed that the induced autophagy had a cytoprotective effect on apoptosis in kaempferol-treated MC-3 cells. Kaempferol also decreased the expression of phosphorylated extracellular signal-regulated kinase and increased that of phosphorylated c-Jun N-terminal kinase (p-JNK) and phosphorylated p38 kinase in MC-3 cells, suggesting the occurrence of mitogen-activated protein kinase-mediated apoptosis and JNK-mediated autophagy. In vivo, kaempferol reduced tumor growth inducing apoptosis and autophagy. These results showed that kaempferol has the potential use as an adjunctive agent in treating oral cancer.
RESUMO
Platycodin D (PD) is the main component of triterpene saponins found in Platycodi radix. In this study, we observed a decrease in cell viability, an increase in apoptotic bodies, and an increase in the rate of apoptosis. Also, we observed an increase in cleaved PARP and Bax, a decrease in Bcl-2, and p-ERK, and an increase in p-p38 and p-JNK. Furthermore, a change in cell viability and the expression of p-p38, Bax, and Bcl-2 using the p38 inhibitor revealed a decrease in p-p38 and Bax and an increase in Bcl-2 in the inhibitor treatment group. In addition, we observed an increase in vacuole formation through morphological changes and an increase in acidic vesicular organelles (AVOs). We also observed an increase in the expression of beclin 1, LC 3-I, and -II. There was no significant decrease in cell viability in the group treated with 3-MA, but a decrease in cell viability was noted in the group treated with HCQ. HCQ treatment resulted in an increase in Bax and a decrease in Bcl-2. These findings reveal that in HT-29 colon cancer cells, PD induces apoptosis through the MAPK pathway, thereby exerting anticancer effects. Moreover, autophagy caused by PD inhibits apoptosis by protecting the cells.
Assuntos
Neoplasias do Colo , Saponinas , Triterpenos , Humanos , Proteína X Associada a bcl-2 , Saponinas/farmacologia , Triterpenos/farmacologia , Apoptose , Autofagia , Neoplasias do Colo/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2RESUMO
The stabilization of peptide's active conformation is a critical determinant of its target binding efficiency. Here we present a structure-based self-assembly strategy for the design of nanostructures with multiple and thermostable α-helices using bioinspired peptide amphiphiles. The design principle was inspired by the oligomerization of the human immunodeficiency virus type-1 (HIV-1) Rev protein. Our goal was to find a strategy to modify the Rev protein into a chemically manageable self-assembling peptide while stabilizing its α-helical structure. Instead of using cyclic peptides for structure stabilization, this strategy utilizes the pseudocyclization for helix stabilization. The self-assembly induced stabilization of α-helical conformation could be observed, and the α-helices were found to be stable even at high temperature (at least up to 74 °C). Conjugation of a hydrophobic alkyl chain to the Rev peptide was crucial for forming the self-assembled nanostructures, and no nanostructures could be obtained without this modification. Because chemical modifications to the α-helical peptide domain can be avoided, potentially any α-helical peptide fragment can be grafted into this self-assembling peptide scaffold.