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1.
Apoptosis ; 28(3-4): 627-638, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36719469

RESUMO

Recent evidence have indicated that ferroptosis, a novel iron-dependent form of non-apoptotic cell death, plays a critical role in human cancers. Besides, emerging literatures have revealed the ovel function of N6-methyladenosine (m6A) in bladder cancer physiological. However, the underlying mechanism of m6A on bladder cancer is still unclear. Here, present work revealed that m6A methyltransferase ('writer') WTAP up-regulated in bladder cancer tissue and cells, indicating the poor prognosis of bladder cancer patients. Functionally, gain/loss-of-functional experiments illustrated that WTAP promoted the viability of bladder cancer cells and inhibited the erastin-induced ferroptosis. Mechanistically, there was a remarkable m6A modification site on 3'-UTR of endogenous antioxidant factor NRF2 RNA and WTAP could install its methylation. Moreover, m6A reader YTHDF1 recognized the m6A site on NRF2 mRNA and enhanced its mRNA stability. Therefore, these findings demonstrated potential therapeutic strategyies for bladder cancer via m6A-dependent manner.


Assuntos
Ferroptose , Neoplasias da Bexiga Urinária , Humanos , Regiões 3' não Traduzidas , Apoptose , Proteínas de Ciclo Celular , Ferroptose/genética , Fator 2 Relacionado a NF-E2/genética , Fatores de Processamento de RNA , Neoplasias da Bexiga Urinária/genética
2.
Molecules ; 28(14)2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37513208

RESUMO

The composition, structure, and functionalities of prolamins from highland barley were investigated. These parameters were compared with those of the commonly applied prolamins (zein). There are more charged and hydrophilic amino acids in highland barely prolamins than zein. The molecular weight of highland barely prolamins was between 30 and 63 kDa, which was larger than that of zein (20 and 24 kDa). The main secondary structure of highland barely prolamins was ß-turn helices, while α-helical structures were the main secondary structure in zein. The water holding capacity, thermal stability, emulsifying capacity, and stability of prolamins from highland barley were significantly higher than in zein, while the opposite results were observed for oil absorption capacity between the two. The diameter of fibers prepared using highland barely prolamins was almost six times that of zein, while highland barely prolamins formed ribbon structures instead of fibers. Therefore, the results provide guidance for applications of prolamins from highland barley.


Assuntos
Hordeum , Zeína , Prolaminas/química , Prolaminas/metabolismo , Zeína/química , Hordeum/metabolismo , Estrutura Secundária de Proteína , Aminoácidos
3.
Langmuir ; 38(30): 9166-9185, 2022 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-35852171

RESUMO

In this paper, the microscopic mechanisms and macroscopic characteristics of polymer/nanoparticle foam flooding in a heavy oil reservoir environment were studied. Sodium dodecyl sulfate (SDS) surfactant was used as the foaming agent, and the foam was prepared by a combination of partially hydrolyzed polyacrylamide (HPAM) polymer and SiO2 nanoparticles. By performing experiments with the microscopic model, the foam flooding dynamics in the heavy oil reservoir were simulated. Based on the experiments, the formula model was established to evaluate the physicochemical effects between the foam liquid film and oil surface. Finally, the macroscopic characteristics of foam flooding were studied by performing oil displacement experiments with a 2D visual model. The microscopic experiments demonstrated that the foam liquid film could exert multiple actions, such as adsorption, stretching, and cutting on the heavy oil in the reservoir pores. These actions were accompanied by force changes between the foam and heavy oil, and the addition of polymer and nanoparticles further strengthened them. The calculations of the formula model indicated that the polymer and nanoparticles amplified the force between the foam liquid film and heavy oil by 1.95 and 2.2 times, respectively. The 2D visual model experiments suggested that foam flooding could further develop heavy oil after water flooding through its liquid film effects, and the oil recovery efficiency increased from 42.43 to 57.82%. In addition, the polymer and nanoparticles further optimized the oil displacement effect of the foam liquid film, which made the oil recovery efficiency reach 64.77-68.16%.

4.
Pacing Clin Electrophysiol ; 45(12): 1401-1408, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36209460

RESUMO

BACKGROUND: Wolff-Parkinson-White (WPW) concomitant with atrial tachyarrhythmia (ATA) has not been systemically characterized. METHODS: Detailed electroanatomical mapping of the right atrium (RA) and/or left atrium (LA) was performed using three-dimensional mapping and the accessory pathway (AP) was mapped. RESULTS: WPW syndrome with ATA was diagnosed in 11 patients (median age 60 years). The characteristic of unidirectional anterograde conduction over the AP was displayed in nine patients, six of whom were intermittent. Sustained atrial tachycardia, that is, counterclockwise atrial flutter (AFL) with a median tachycardia cycle length (TCL) of 225 (220-275) ms, was mapped in eight patients; furthermore, "figure 8" right atrial reentry was mapped with TCL 250 ms in one patient with a surgical history of ventricular septal defect repair. The remaining two patients underwent mitral annulus-dependent AT after paroxysmal atrial fibrillation (PAF) ablation and LA micro-reentry AT, respectively. In four patients, the location of the APs was left posterior. Left-lateral APs were identified in four patients. The locations of the APs in the remaining three patients were the right posterior and middle septum. All ATAs and APs were successfully ablated. After a median follow-up of 37 (15-72) months, no anterograde conduction over the AP was recorded, new onset of PAF was recorded in three patients, and all of them underwent circumferential pulmonary vein isolation. CONCLUSIONS: WPW with concomitant ATA frequently had continuous anterograde conduction over the AP with a rapid ventricular rate. Most WPWs displayed the characteristic of unidirectional anterograde conduction.


Assuntos
Síndromes de Pré-Excitação , Humanos , Pessoa de Meia-Idade , Síndromes de Pré-Excitação/complicações , Síndromes de Pré-Excitação/diagnóstico , Síndromes de Pré-Excitação/cirurgia , Átrios do Coração/cirurgia
5.
Blood ; 131(3): 328-341, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29113963

RESUMO

Additional Sex Combs-Like 1 (ASXL1) is mutated at a high frequency in all forms of myeloid malignancies associated with poor prognosis. We generated a Vav1 promoter-driven Flag-Asxl1Y588X transgenic mouse model, Asxl1Y588X Tg, to express a truncated FLAG-ASXL1aa1-587 protein in the hematopoietic system. The Asxl1Y588X Tg mice had an enlarged hematopoietic stem cell (HSC) pool, shortened survival, and predisposition to a spectrum of myeloid malignancies, thereby recapitulating the characteristics of myeloid malignancy patients with ASXL1 mutations. ATAC- and RNA-sequencing analyses revealed that the ASXL1aa1-587 truncating protein expression results in more open chromatin in cKit+ cells compared with wild-type cells, accompanied by dysregulated expression of genes critical for HSC self-renewal and differentiation. Liquid chromatography-tandem mass spectrometry and coimmunoprecipitation experiments showed that ASXL1aa1-587 acquired an interaction with BRD4. An epigenetic drug screening demonstrated a hypersensitivity of Asxl1Y588X Tg bone marrow cells to BET bromodomain inhibitors. This study demonstrates that ASXL1aa1-587 plays a gain-of-function role in promoting myeloid malignancies. Our model provides a powerful platform to test therapeutic approaches of targeting the ASXL1 truncation mutations in myeloid malignancies.


Assuntos
Mutação com Ganho de Função/genética , Leucemia Mieloide/genética , Proteínas Repressoras/genética , Animais , Células da Medula Óssea/metabolismo , Diferenciação Celular/genética , Linhagem da Célula/genética , Cromatina/metabolismo , Regulação Leucêmica da Expressão Gênica , Células-Tronco Hematopoéticas/metabolismo , Leucemia Mieloide/patologia , Camundongos Transgênicos , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Proteínas Proto-Oncogênicas c-kit/metabolismo , Proteínas Proto-Oncogênicas c-vav/metabolismo , Fatores de Transcrição/metabolismo
6.
Langmuir ; 36(48): 14748-14762, 2020 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-33213147

RESUMO

This paper combined experiments with a theoretical model to simulate the behavior between a foam and heavy oil during contact pressing, separation, and adsorption. We discuss the changes in the elasticity and adsorption forces during the pressing and adsorption of the two fluids. The influence of the changes in temperature and pressure, the concentration of the sodium dodecyl sulfate surfactant, the heavy oil viscosity, and the addition of partially hydrolyzed polyacrylamide and hydrophobic SiO2 nanoparticles was studied. The results showed that the overall increase in the elasticity and adsorption forces between the foam at 1 wt % surfactant and heavy oil was more than 2 times greater than those of the foam with 0.2 wt % surfactant. The increase in viscosity of heavy oil also increased various forces. The overall improvement in the adsorption force between fluids caused by nanoparticles during separation and adsorption stages reached 1.8 times, which was better than that obtained using the polymer (1.65 times). However, the polymer showed a 1.4 times higher elastic force during the fluid pressing stage than the nanoparticles and about 4 times higher than the control foam, and the increase in temperature greatly weakened the effect of the force, while the change in pressure did not cause much impact. An analytical model was built based on fluid mechanics, and the calculation results were consistent with the experimental data with an error of about 5-12%, suggesting that this model provides a good reference value.

7.
Clin Exp Pharmacol Physiol ; 45(6): 573-580, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29164657

RESUMO

Some studies have revealed that nicotine can damage the male reproductive system through various means including oxidative stress, which is a primary factor in the pathogenesis of male infertility. The strong anti-oxidative capacity of resveratrol has been demonstrated previously, but its role in the context of male reproduction remains inconclusive. To explore the biological role of resveratrol in protecting male reproductive function and the potential underlying mechanism, nicotine-induced Leydig cells were used as a cell model of oxidative damage. The data showed that resveratrol treatment increased cell viability, SOD activity and anti-apoptotic activity in nicotine-stressed Leydig cells. This effect was accompanied by the upregulation of autophagy, which was illustrated by MDC-LysoTracker red staining. Moreover, pretreating with 3-methyladenine (3-MA), an autophagy inhibitor, attenuated resveratrol-induced Leydig cells autophagy and promoted apoptosis. Apart from this, resveratrol enhanced AMPK phosphorylation but reduced mTOR phosphorylation. Subsequently, upon inhibiting AMPK phosphorylation by AMPK inhibitors, Leydig cell autophagy induced by resveratrol was obviously abolished. In conclusion, resveratrol may exert its cytoprotective role against oxidative injury by the activation of autophagy via AMPK/mTOR pathway.


Assuntos
Autofagia/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Células Intersticiais do Testículo/citologia , Células Intersticiais do Testículo/efeitos dos fármacos , Nicotina/efeitos adversos , Estresse Oxidativo/efeitos dos fármacos , Resveratrol/farmacologia , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Masculino , Camundongos , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Regulação para Cima/efeitos dos fármacos
8.
Blood ; 123(4): 541-53, 2014 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-24255920

RESUMO

ASXL1 is mutated/deleted with high frequencies in multiple forms of myeloid malignancies, and its alterations are associated with poor prognosis. De novo ASXL1 mutations cause Bohring-Opitz syndrome characterized by multiple congenital malformations. We show that Asxl1 deletion in mice led to developmental abnormalities including dwarfism, anophthalmia, and 80% embryonic lethality. Surviving Asxl1(-/-) mice lived for up to 42 days and developed features of myelodysplastic syndrome (MDS), including dysplastic neutrophils and multiple lineage cytopenia. Asxl1(-/-) mice had a reduced hematopoietic stem cell (HSC) pool, and Asxl1(-/-) HSCs exhibited decreased hematopoietic repopulating capacity, with skewed cell differentiation favoring granulocytic lineage. Asxl1(+/-) mice also developed mild MDS-like disease, which could progress to MDS/myeloproliferative neoplasm, demonstrating a haploinsufficient effect of Asxl1 in the pathogenesis of myeloid malignancies. Asxl1 loss led to an increased apoptosis and mitosis in Lineage(-)c-Kit(+) (Lin(-)c-Kit(+)) cells, consistent with human MDS. Furthermore, Asxl1(-/-) Lin(-)c-Kit(+) cells exhibited decreased global levels of H3K27me3 and H3K4me3 and altered expression of genes regulating apoptosis (Bcl2, Bcl2l12, Bcl2l13). Collectively, we report a novel ASXL1 murine model that recapitulates human myeloid malignancies, implying that Asxl1 functions as a tumor suppressor to maintain hematopoietic cell homeostasis. Future work is necessary to clarify the contribution of microenvironment to the hematopoietic phenotypes observed in the constitutional Asxl1(-/-) mice.


Assuntos
Mutação , Síndromes Mielodisplásicas/genética , Proteínas Repressoras/genética , Proteínas Repressoras/fisiologia , Animais , Apoptose , Células da Medula Óssea/citologia , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Cruzamentos Genéticos , Modelos Animais de Doenças , Deleção de Genes , Proteínas de Fluorescência Verde/metabolismo , Hematopoese , Células-Tronco Hematopoéticas/citologia , Homeostase , Homozigoto , Humanos , Camundongos , Camundongos Transgênicos , Mitose , Síndromes Mielodisplásicas/metabolismo , Fenótipo
9.
Soft Matter ; 12(3): 946-56, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26563818

RESUMO

In this work, we have prepared CO2-in-water foam by mixing partially hydrophobic SiO2 nanoparticles and sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and studied its properties. The observation of the appearance of the foam revealed that, with the continuous addition of AOT, the phase behavior of the SiO2 nanoparticle and the AOT mixed system transformed from that of a two-phase system of aggregated nanoparticles into that of a uniform dispersed phase. Both foaming ability and foam stability were optimized when the nanoparticles and the AOT were mixed in a proportion of 1 : 5. On the basis of our findings from measurements of the dispersion properties, including measurements of the adsorption isotherm of the surfactant on the nanoparticles, zeta potentials, interfacial tension and the three-phase contact angle, we concluded that the synergistic interactions between the SiO2 nanoparticles and the AOT led to the adsorption of nanoparticles around the bubble surface and the formation of a spatial network structure of nanoparticles in the film, thereby enhancing the mechanical strength of the bubble and improving the resistance to outside disturbances, deformation and drainage. Laser scanning confocal microscopy (LCSM) analysis of the same foams further confirmed the existence of a "viscoelastic shell" wrapped around and protecting the bubble.

10.
J Biol Chem ; 288(44): 31447-57, 2013 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-24043626

RESUMO

Many proteins exist and function as homodimers. Understanding the detailed mechanism driving the homodimerization is important and will impact future studies targeting the "undruggable" oncogenic protein dimers. In this study, we used 14-3-3σ as a model homodimeric protein and performed a systematic investigation of the potential roles of amino acid residues in the interface for homodimerization. Unlike other members of the conserved 14-3-3 protein family, 14-3-3σ prefers to form a homodimer with two subareas in the dimeric interface that has 180° symmetry. We found that both subareas of the dimeric interface are required to maintain full dimerization activity. Although the interfacial hydrophobic core residues Leu(12) and Tyr(84) play important roles in 14-3-3σ dimerization, the non-core residue Phe(25) appears to be more important in controlling 14-3-3σ dimerization activity. Interestingly, a similar non-core residue (Val(81)) is less important than Phe(25) in contributing to 14-3-3σ dimerization. Furthermore, dissociating dimeric 14-3-3σ into monomers by mutating the Leu(12), Phe(25), or Tyr(84) dimerization residue individually diminished the function of 14-3-3σ in resisting drug-induced apoptosis and in arresting cells at G2/M phase in response to DNA-damaging treatment. Thus, dimerization appears to be required for the function of 14-3-3σ.


Assuntos
Proteínas 14-3-3/metabolismo , Resistência a Medicamentos/fisiologia , Multimerização Proteica/fisiologia , Tolerância a Radiação/fisiologia , Proteínas 14-3-3/genética , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Apoptose/efeitos da radiação , Divisão Celular/efeitos dos fármacos , Divisão Celular/fisiologia , Divisão Celular/efeitos da radiação , Dano ao DNA , Fase G1/efeitos dos fármacos , Fase G1/fisiologia , Fase G1/efeitos da radiação , Células HEK293 , Humanos , Interações Hidrofóbicas e Hidrofílicas , Estrutura Quaternária de Proteína , Relação Estrutura-Atividade
11.
Heart Rhythm ; 20(6): 815-821, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36868545

RESUMO

BACKGROUND: Ablation strategies to treat bundle branch reentrant ventricular tachycardia (BBRT) are well described. However, reports of long-term follow-up outcomes in BBRT patients without structural heart disease (SHD) are limited. OBJECTIVE: The purpose of this study was to investigate the long-term follow-up prognosis of BBRT patients without SHD. METHODS: Changes in electrocardiographic and echocardiographic parameters were used to evaluate progression during follow-up. Potential pathogenic candidate variants were screened using a specific gene panel. RESULTS: Eleven consecutive BBRT patients without obvious SHD based on echocardiographic and cardiovascular magnetic resonance imaging results were enrolled. Median age was 20 (11-48) years, and median follow-up time was 72 months. During follow-up, PR interval [206 (158-360) ms vs 188 (158-300) ms; P = .018] and QRS duration [187 (155-240) ms vs 164 (130-178) ms; P = .008] each increased significantly compared with postablation. Right- and left-sided chamber dilation and reduced left ventricular ejection fraction (LVEF) also were observed. Clinical deterioration or events occurred in 8 patients: 1 sudden death; 3 both complete heart block and reduced LVEF; 2 significantly reduced LVEF; and 2 prolonged PR interval. Genetic testing results showed that 6 of 10 patients (excluding the patient with sudden death) had ≥1 potential pathogenic candidate variants. CONCLUSION: Further deterioration of His-Purkinje system conduction was observed in young BBRT patients without SHD after ablation. The His-Purkinje system may be the first target of genetic predisposition.


Assuntos
Bloqueio Atrioventricular , Taquicardia Ventricular , Humanos , Adulto Jovem , Adulto , Bloqueio de Ramo , Volume Sistólico , Função Ventricular Esquerda , Arritmias Cardíacas , Eletrocardiografia , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/genética , Taquicardia Ventricular/cirurgia , Fascículo Atrioventricular
12.
ACS Nano ; 17(3): 3181-3193, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36655945

RESUMO

Biophysical cues can facilitate the cardiac differentiation of human pluripotent stem cells (hPSCs), yet the mechanism is far from established. One of the binary colloidal crystals, composed of 5 µm Si and 400 nm poly(methyl methacrylate) particles named 5PM, has been applied as a substrate for hPSCs cultivation and cardiac differentiation. In this study, cell nucleus, cytoskeleton, and epigenetic states of human induced pluripotent stem cells on the 5PM were analyzed using atomic force microscopy, molecular biology assays, and the assay for transposase-accessible chromatin sequencing (ATAC-seq). Cells were more spherical with stiffer cell nuclei on the 5PM compared to the flat control. ATAC-seq revealed that chromatin accessibility decreased on the 5PM, caused by the increased entry of histone lysine methyltransferase SETDB1 into the cell nuclei and the amplified level of histone H3K9me3 modification. Reducing cytoskeleton tension using a ROCK inhibitor attenuated the nuclear accumulation of SETDB1 on the 5PM, indicating that the effect is cytoskeleton-dependent. In addition, the knockdown of SETDB1 reversed the promotive effects of the 5PM on cardiac differentiation, demonstrating that biophysical cue-induced cytoskeletal tension, cell nucleus deformation, and then SETDB1 accumulation are critical outside-in signal transformations in cardiac differentiation. Human embryonic stem cells showed similar results, indicating that the biophysical impact of the 5PM surfaces on cardiac differentiation could be universal. These findings contribute to our understanding of material-assistant hPSC differentiation, which benefits materiobiology and stem cell bioengineering.


Assuntos
Células-Tronco Pluripotentes Induzidas , Células-Tronco Pluripotentes , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes/metabolismo , Diferenciação Celular , Cromatina , Histona-Lisina N-Metiltransferase/genética , Histona-Lisina N-Metiltransferase/metabolismo
13.
J Proteome Res ; 11(2): 1364-72, 2012 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-22188235

RESUMO

Human ABCC1 is a member of the ATP-binding cassette (ABC) transporter superfamily, and its overexpression has been shown to cause multidrug resistance by active efflux of a wide variety of anticancer drugs. ABCC1 has been shown to exist and possibly function as a homodimer. However, a possible heterocomplex involving ABCC1 has been indicated. In this study, we performed an interactive proteomics study to examine proteins that bind to and form heterocomplexes with ABCC1 using coimmunoprecipitation and tandem mass spectrometry (MS/MS) analyses. We found that ATP synthase α binds to ABCC1 in plasma membranes with a ratio of 2:1. The ATP synthase α binding site in ABCC1 is located in the linker domain at the carboxyl core of ABCC1, and phosphorylation of the linker domain at the protein kinase A site enhances ATP synthase α binding. The interaction between ABCC1 and ATP synthase α in a heterocomplex may indicate a novel function of ABCC1 in regulating extracellular ATP level and purinergic signaling cascade.


Assuntos
ATPases Mitocondriais Próton-Translocadoras/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Células HEK293 , Humanos , Imunoprecipitação , ATPases Mitocondriais Próton-Translocadoras/química , Modelos Biológicos , Dados de Sequência Molecular , Proteínas Associadas à Resistência a Múltiplos Medicamentos/química , Fosforilação , Ligação Proteica , Mapeamento de Interação de Proteínas/métodos , Proteômica/métodos , Reprodutibilidade dos Testes
14.
RSC Adv ; 12(24): 15584-15592, 2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35685180

RESUMO

A bioinspired PEEK material with hard "bricks" of nanoscale lamellae and micron-scale deformed spherulites bonded by soft "mortar" of a rigid amorphous fraction was produced with a pressure-induced flow (PIF) processing applied in the solid-state. Novel mechanisms were proposed for the marked and simultaneous improvement in the strength and toughness, where the tensile strength and impact strength could be increased to ∼200% and ∼450%, respectively. On one hand, the rotation, recombination and restacking of the crystalline blocks formed an oriented and stratified morphology similar to the "brick-and-mortar" structure in nacre, and resulted in the confined crack propagations and the tortuous energy dissipating paths. On the other hand, the PIF-relaxation due to the newly generated rigid amorphous fraction further contributed to the improvement of the impact strength. The efficiency of enhancement could be controlled by the molding temperature, the compression ratio, and the volume fraction of chopped carbon fiber. As a result, PIF-processing might endow the PEEK material with improved mechanical matching with the surrounding tissues and extended service life in biomedical applications while retaining excellent biocompatibility with no external substances introduced.

15.
Stem Cell Res ; 62: 102810, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35580545

RESUMO

We generated an iPSCs line from the peripheral blood mononuclear cells (PBMCs) collected from a patient with long QT syndrome type 1 (LQT1) via a non-integrating system. We identified and verified a missense mutation in the KCNQ1 gene (c.773A > T) by whole-exome sequencing and Sanger sequencing. The established iPSC line was tested for pluripotency, differentiation potential, and karyotype. This cell-based model can help study the molecular mechanism and develop personalized drug therapies for LQT1.


Assuntos
Células-Tronco Pluripotentes Induzidas , Síndrome de Romano-Ward , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Canal de Potássio KCNQ1/genética , Canal de Potássio KCNQ1/metabolismo , Leucócitos Mononucleares/metabolismo , Mutação/genética , Síndrome de Romano-Ward/genética , Síndrome de Romano-Ward/metabolismo
16.
Front Cardiovasc Med ; 9: 840337, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35360035

RESUMO

PRKAG2 cardiomyopathy is a rare progressive disease characterized by increased ventricular wall thickness and preexcitation. Dysfunction of the protein 5'-AMP-activated protein kinase (AMPK) plays a decisive role in the progression of ventricular lesions. Although patients with the PRKAG2-R302Q mutation have a high incidence of atrial fibrillation (AF), the molecular mechanism contributing to the disease remains unclear. We carried out whole-genome sequencing with linkage analysis in three affected members of a family. Atrial samples were obtained from the proband via surgical intervention. Control atrium biopsies were obtained from patients with persistent AF. Pathological changes were analyzed using the hematoxylin and eosin (H&E), Masson, and periodic acid-Schiff (PAS) staining. The AMPK signaling pathway was investigated by western blot. A murine atrial cardiomyocyte cell line (HL-1) and human induced pluripotent stem derived atrial cardiomyocytes (hiPSC-ACMs) were transfected with an adenovirus carrying the same mutation. We used enzyme linked immunosorbent assay (ELISA) to determine the AMPK activity in HL-1 cells and hiPSC-ACMs overexpressing PRKAG2-R302Q. Pathological results showed a large quantity of glycogen accumulation and vacuolization in cardiomyocytes from the proband atrial tissue. Western blot analysis revealed that the AMPK activity was significantly downregulated compared with that of the controls. Furthermore, remarkable glycogen deposition and impairment of AMPK activity were reproduced in HL-1 cells overexpressing PRKAG2-R302Q. Taken together, PRKAG2-R302Q mutation directly impair atrial cardiomyocytes. PRKAG2-R302Q mutation lead to glycogen deposition and promote the growth of atrial lesions by disrupting the AMPK pathway.

17.
Heart Rhythm ; 19(3): 466-475, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34808346

RESUMO

BACKGROUND: The literature on laminopathy with ventricular phenotype is extensive. However, the pathogenicity of LMNA variations in atrial lesions still lacks research. OBJECTIVE: The purpose of this study was to characterize the atrial phenotypes and possible mechanisms in a large Chinese family with heart-hand syndrome carrying a LMNA missense variant in rod 2B domain (c.1003C>T p.R335W). METHODS: Clinical characteristics were collected on the basis of the pedigree investigation. Comprehensive functional analyses, including molecular dynamic (MD) simulation, cellular, and animal functional assays, determined the pathogenicity in atrial myopathy. RESULTS: In the pedigree investigation, 6 of 13 of the mutation carriers showed heterogeneous cardiac phenotypes and 8 carriers also had brachydactyly. In silico molecular dynamics simulations predicted increased binding energy of the R335W mutant lamin A. Atrial cardiomyocytes (HL-1, human induced pluripotent stem cell-derived atrial cardiomyocytes) expressing R335W showed abnormal nuclear morphology, compromised DNA repair, and dysfunctional contraction. Adult zebrafish expressing mutant lamin A showed increased P wave duration in the electrocardiogram, decreased peak A wave velocity in echocardiography, and atrial lesions under the transmission electron microscope. CONCLUSION: LMNA p.R335W mutation leads to familial heart-hand syndrome characterized by an overlapping phenotype of prominent atrial lesions and brachydactyly. The unstable lamin dimerization and impaired DNA repair are possible mechanisms underlying cardiac phenotypes. Our findings consolidated the genetic role in the course of atrial arrhythmias and cardiac aging, which is helpful in the diagnosis and treatment of cardiac laminopathy.


Assuntos
Braquidactilia , Células-Tronco Pluripotentes Induzidas , Lamina Tipo A , Laminopatias , Doenças Musculares , Anormalidades Múltiplas , Animais , Cardiopatias Congênitas , Comunicação Interatrial , Humanos , Lamina Tipo A/genética , Deformidades Congênitas das Extremidades Inferiores , Mutação , Linhagem , Deformidades Congênitas das Extremidades Superiores , Peixe-Zebra/genética
18.
J Chem Inf Model ; 51(10): 2612-25, 2011 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-21870863

RESUMO

Many proteins exist and function as oligomers. While hydrophobic interactions have been recognized as the major driving force for oligomerization, detailed molecular mechanisms for the assembly are unknown. Here, we used 14-3-3σ as a model protein and investigated the role of hydrophobic residues at the dimeric interface using MD simulations and coimmunoprecipitations. We found that a half-exposed and half-buried residue in the interface, Phe(25), plays a more important role in promoting homodimerization than the hydrophobic core residues by organizing both favorable hydrophobic and hydrophilic interactions. Phe(25) is critical in packing and stabilizing hydrophobic core residues. We conclude that the structural stability of hydrophobic cores is critical for a stable homodimer complex and this stable property can be bestowed by residues outside of hydrophobic core. The important organizing activity of Phe(25) for homodimerization of 14-3-3σ originates from its unique physical location, rigidity, size, and hydrophobicity. Thus, hydrophobic residues that are not deeply buried at the oligomeric interface may play important but different roles from the buried core residues and they may promote oligomerization by organizing co-operativity of core and other residues for favorable hydrophobic and electrostatic interactions.


Assuntos
Proteínas 14-3-3/química , Biomarcadores Tumorais/química , Exonucleases/química , Simulação de Dinâmica Molecular , Fenilalanina , Multimerização Proteica , Proteínas 14-3-3/genética , Proteínas 14-3-3/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Cristalografia por Raios X , Exonucleases/genética , Exonucleases/metabolismo , Exorribonucleases , Humanos , Interações Hidrofóbicas e Hidrofílicas , Imunoprecipitação , Mutação , Estabilidade Proteica , Estrutura Quaternária de Proteína , Estrutura Secundária de Proteína , Eletricidade Estática , Termodinâmica , Água/química
19.
Toxicol In Vitro ; 77: 105233, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34390763

RESUMO

The awareness of the long-term toxicities of cancer survivors after chemotherapy treatment has been gradually strengthened as the population of cancer survivors grows. Generally, chemotherapy-induced peripheral neurotoxicity (CIPN) is studied by animal models which are not only expensive and time-consuming, but also species-specific differences. The generation of human induced pluripotent stem cells (hiPSCs) and differentiation of peripheral neurons have provided an in vitro model to elucidate the risk of CIPN. Here, we developed a drug-induced peripheral neurotoxicity model using hiPSC-derived peripheral neurons (hiPSC-PNs) to study the mechanisms of different chemotherapeutic agents on neuronal viability using LDH assay, a cell apoptosis assay determined by caspase 3/7 activation, neurite outgrowth, ion channel expression and neurotransmitter release following treatment of cisplatin, bortezomib, ixabepilone, or pomalidomide. Our data showed that the multiple endpoints of the hiPSC-PNs model had different sensitivity to various chemotherapeutic agents. Furthermore, the chemotherapeutics separated cell viability from the decrease in neurite lengthand changed levels of ion channels and neurotransmitters to a certain extent. Thus, we study the mechanisms of peripheral neurotoxicity induced by chemotherapeutic agents through changes in these indicators.


Assuntos
Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Síndromes Neurotóxicas/etiologia , Neurotoxinas/toxicidade , Diferenciação Celular/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Humanos , Reação em Cadeia da Polimerase em Tempo Real
20.
Cell Discov ; 7(1): 64, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34373443

RESUMO

Coronavirus disease 2019 (COVID-19), driven by SARS-CoV-2, is a severe infectious disease that has become a global health threat. Vaccines are among the most effective public health tools for combating COVID-19. Immune status is critical for evaluating the safety and response to the vaccine, however, the evolution of the immune response during immunization remains poorly understood. Single-cell RNA sequencing (scRNA-seq) represents a powerful tool for dissecting multicellular behavior and discovering therapeutic antibodies. Herein, by performing scRNA/V(D)J-seq on peripheral blood mononuclear cells from four COVID-19 vaccine trial participants longitudinally during immunization, we revealed enhanced cellular immunity with concerted and cell type-specific IFN responses as well as boosted humoral immunity with SARS-CoV-2-specific antibodies. Based on the CDR3 sequence and germline enrichment, we were able to identify several potential binding antibodies. We synthesized, expressed and tested 21 clones from the identified lineages. Among them, one monoclonal antibody (P3V6-1) exhibited relatively high affinity with the extracellular domain of Spike protein, which might be a promising therapeutic reagent for COVID-19. Overall, our findings provide insights for assessing vaccine through the novel scRNA/V(D)J-seq approach, which might facilitate the development of more potent, durable and safe prophylactic vaccines.

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