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1.
Cell ; 152(5): 1037-50, 2013 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-23452852

RESUMO

Although somatic cell reprogramming to generate inducible pluripotent stem cells (iPSCs) is associated with profound epigenetic changes, the roles and mechanisms of epigenetic factors in this process remain poorly understood. Here, we identify Jmjd3 as a potent negative regulator of reprogramming. Jmjd3-deficient MEFs produced significantly more iPSC colonies than did wild-type cells, whereas ectopic expression of Jmjd3 markedly inhibited reprogramming. We show that the inhibitory effects of Jmjd3 are produced through both histone demethylase-dependent and -independent pathways. The latter pathway involves Jmjd3 targeting of PHF20 for ubiquitination and degradation via recruitment of an E3 ligase, Trim26. Importantly, PHF20-deficient MEFs could not be converted to fully reprogrammed iPSCs, even with knockdown of Jmjd3, Ink4a, or p21, indicating that PHF20 is required for reprogramming. Our findings demonstrate, to the best of our knowledge, a previously unrecognized role of Jmjd3 in cellular reprogramming and provide molecular insight into the mechanisms by which the Jmjd3-PHF20 axis controls this process.


Assuntos
Reprogramação Celular , Proteínas de Homeodomínio/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Histona Desmetilases com o Domínio Jumonji/metabolismo , Animais , Inibidor p16 de Quinase Dependente de Ciclina/genética , Proteínas de Ligação a DNA , Embrião de Mamíferos/citologia , Fibroblastos/metabolismo , Cinética , Camundongos , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise , Fatores de Transcrição , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Regulação para Cima
2.
J Biol Chem ; 300(3): 105667, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38272228

RESUMO

The aggregation of α-Synuclein (α-Syn) into amyloid fibrils is the hallmark of Parkinson's disease. Under stress or other pathological conditions, the accumulation of α-Syn oligomers is the main contributor to the cytotoxicity. A potential approach for treating Parkinson's disease involves preventing the accumulation of these α-Syn oligomers. In this study, we present a novel mechanism involving a conserved group of disorderly proteins known as small EDRK-rich factor (SERF), which promotes the aggregation of α-Syn through a cophase separation process. Using diverse methods like confocal microscopy, fluorescence recovery after photobleaching assays, solution-state NMR spectroscopy, and Western blot, we determined that the N-terminal domain of SERF1a plays a role in the interactions that occur during cophase separation. Within these droplets, α-Syn undergoes a gradual transformation from solid condensates to amyloid fibrils, while SERF1a is excluded from the condensates and dissolves into the solution. Notably, in vivo experiments show that SERF1a cophase separation with α-Syn significantly reduces the deposition of α-Syn oligomers and decreases its cellular toxicity under stress. These findings suggest that SERF1a accelerates the conversion of α-Syn from highly toxic oligomers to less toxic fibrils through cophase separation, thereby mitigating the biological damage of α-Syn aggregation.


Assuntos
Doença de Parkinson , alfa-Sinucleína , Humanos , alfa-Sinucleína/química , alfa-Sinucleína/metabolismo , Amiloide/química , Doença de Parkinson/metabolismo , Separação de Fases , Agregados Proteicos , Agregação Patológica de Proteínas/metabolismo , Fatores de Transcrição , Antígenos de Grupos Sanguíneos/química , Antígenos de Grupos Sanguíneos/metabolismo , Células HeLa , Eletricidade Estática
3.
J Biol Chem ; 299(2): 102857, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36592929

RESUMO

Cu/Zn superoxide dismutase 1 (SOD1) has a high propensity to misfold and form abnormal aggregates when it is subjected to oxidative stress or carries mutations associated with amyotrophic lateral sclerosis. However, the transition from functional soluble SOD1 protein to aggregated SOD1 protein is not completely clear. Here, we propose that liquid-liquid phase separation (LLPS) represents a biophysical process that converts soluble SOD1 into aggregated SOD1. We determined that SOD1 undergoes LLPS in vitro and cells under oxidative stress. Abnormal oxidation of SOD1 induces maturation of droplets formed by LLPS, eventually leading to protein aggregation and fibrosis, and involves residues Cys111 and Trp32. Additionally, we found that pathological mutations in SOD1 associated with ALS alter the morphology and material state of the droplets and promote the transformation of SOD1 to solid-like oligomers which are toxic to nerve cells. Furthermore, the fibrous aggregates formed by both pathways have a concentration-dependent toxicity effect on nerve cells. Thus, these combined results strongly indicate that LLPS may play a major role in pathological SOD1 aggregation, contributing to pathogenesis in ALS.


Assuntos
Esclerose Lateral Amiotrófica , Superóxido Dismutase-1 , Humanos , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Mutação , Dobramento de Proteína , Superóxido Dismutase-1/química , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/metabolismo , Transição de Fase
4.
Plant Mol Biol ; 114(3): 36, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38598012

RESUMO

Increasing evidence indicates a strong correlation between the deposition of cuticular waxes and drought tolerance. However, the precise regulatory mechanism remains elusive. Here, we conducted a comprehensive transcriptome analysis of two wheat (Triticum aestivum) near-isogenic lines, the glaucous line G-JM38 rich in cuticular waxes and the non-glaucous line NG-JM31. We identified 85,143 protein-coding mRNAs, 4,485 lncRNAs, and 1,130 miRNAs. Using the lncRNA-miRNA-mRNA network and endogenous target mimic (eTM) prediction, we discovered that lncRNA35557 acted as an eTM for the miRNA tae-miR6206, effectively preventing tae-miR6206 from cleaving the NAC transcription factor gene TaNAC018. This lncRNA-miRNA interaction led to higher transcript abundance for TaNAC018 and enhanced drought-stress tolerance. Additionally, treatment with mannitol and abscisic acid (ABA) each influenced the levels of tae-miR6206, lncRNA35557, and TaNAC018 transcript. The ectopic expression of TaNAC018 in Arabidopsis also improved tolerance toward mannitol and ABA treatment, whereas knocking down TaNAC018 transcript levels via virus-induced gene silencing in wheat rendered seedlings more sensitive to mannitol stress. Our results indicate that lncRNA35557 functions as a competing endogenous RNA to modulate TaNAC018 expression by acting as a decoy target for tae-miR6206 in glaucous wheat, suggesting that non-coding RNA has important roles in the regulatory mechanisms responsible for wheat stress tolerance.


Assuntos
Arabidopsis , MicroRNAs , RNA Longo não Codificante , RNA Endógeno Competitivo , RNA Longo não Codificante/genética , Ácido Abscísico/farmacologia , Arabidopsis/genética , Manitol , MicroRNAs/genética , RNA Mensageiro , Triticum/genética , Ceras
5.
Small ; 20(9): e2306698, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37840390

RESUMO

Hierarchical architecture engineering is desirable in integrating the physical-chemical behaviors and macroscopic properties of materials, which present great potential for developing multifunctional microwave absorption materials. However, the intrinsic mechanisms and correlation conditions among cellular units have not been revealed, which are insufficient to maximize the fusion of superior microwave absorption (MA) and derived multifunctionality. Herein, based on three models (disordered structure, porous structure, lamellar structure) of structural units, a range of MXene-aerogels with variable constructions are fabricated by a top-down ice template method. The aerogel with lamellar structure with a density of only 0.015 g cm-3 exhibits the best MA performance (minimum reflection loss: -53.87 dB, effective absorption bandwidth:6.84 GHz) at a 6 wt.% filling ratio, which is preferred over alternative aerogels with variable configurations. This work elucidates the relationship between the hierarchical architecture and the superior MA performance. Further, the MXene/CoNi Composite aerogel with lamellar structure exhibits >90% compression stretch after 1000 cycles, excellent compressive properties, and elasticity, as well as high hydrophobicity and thermal insulation properties, broadening the versatility of MXene-based aerogel applications. In short, through precise microstructure design, this work provides a conceptually novel strategy to realize the integration of electromagnetic stealth, thermal insulation, and load-bearing capability simultaneously.

6.
Small ; 20(33): e2310939, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38453670

RESUMO

Nickel oxide (NiOx) is commonly used as a holetransporting material (HTM) in p-i-n perovskite solar cells. However, the weak chemical interaction between the NiOx and CH3NH3PbI3 (MAPbI3) interface results in poor crystallinity, ineffective hole extraction, and enhanced carrier recombination, which are the leading causes for the limited stability and power conversion efficiency (PCE). Herein, two HTMs, TRUX-D1 (N2,N7,N12-tris(9,9-dimethyl-9H-fluoren-2-yl)-5,5,10,10,15,15-hexaheptyl-N2,N7,N12-tris(4-methoxyphenyl)-10,15-dihydro-5H-diindeno[1,2-a:1',2'-c]fluorene-2,7,12-triamine) and TRUX-D2 (5,5,10,10,15,15-hexaheptyl-N2,N7,N12-tris(4-methoxyphenyl)-N2,N7,N12-tris(10-methyl-10H-phenothiazin-3-yl)-10,15-dihydro-5H-diindeno[1,2-a:1',2'-c]fluorene-2,7,12-triamine), are designed with a rigid planar C3 symmetry truxene core integrated with electron-donating amino groups at peripheral positions. The TRUX-D molecules are employed as effective interfacial layer (IFL) materials between the NiOx and MAPbI3 interface. The incorporation of truxene-based IFLs improves the quality of perovskite crystallinity, minimizes nonradiative recombination, and accelerates charge extraction which has been confirmed by various characterization techniques. As a result, the TRUX-D1 exhibits a maximum PCE of up to 20.8% with an impressive long-term stability. The unencapsulated device retains 98% of their initial performance following 210 days of aging in a glove box and 75.5% for the device after 80 days under ambient air condition with humidity over 40% at 25 °C.

7.
Phys Rev Lett ; 132(5): 056702, 2024 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-38364119

RESUMO

We report a giant hysteretic spin Seebeck effect (SSE) anomaly with a sign reversal at magnetic fields much stronger than the coercive field in a (001)-oriented Tb_{3}Fe_{5}O_{12} film. The high-field SSE enhancement reaches 4200% at approximately 105 K over its weak-field value and presents a nonmonotonic dependence on temperature. The unexpected high-field hysteresis of SSE is found to be associated with a magnetic transition of double-umbrella spin texture in TbIG. Nearly parallel dispersion curves of magnons and acoustic phonons around this neoteric transition are supported by theoretical calculations, leading to a high density of field-tuned magnon polarons and consequently an extraordinarily large SSE. Our study provides insight into the evolution of magnon dispersions of double-umbrella TbIG and could potentially boost the efficiency of magnon-polarons SSE devices.

8.
Cerebellum ; 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38558026

RESUMO

Repetitive transcranial magnetic stimulation (rTMS), a noninvasive neuroregulatory technique used to treat neurodegenerative diseases, holds promise for spinocerebellar ataxia type 3 (SCA3) treatment, although its efficacy and mechanisms remain unclear. This study aims to observe the short-term impact of cerebellar rTMS on motor function in SCA3 patients and utilize resting-state functional magnetic resonance imaging (RS-fMRI) to assess potential therapeutic mechanisms. Twenty-two SCA3 patients were randomly assigned to receive actual rTMS (AC group, n = 11, three men and eight women; age 32-55 years) or sham rTMS (SH group, n = 11, three men and eight women; age 26-58 years). Both groups underwent cerebellar rTMS or sham rTMS daily for 15 days. The primary outcome measured was the ICARS scores and parameters for regional brain activity. Compared to baseline, ICARS scores decreased more significantly in the AC group than in the SH group after the 15-day intervention. Imaging indicators revealed increased Amplitude of Low Frequency Fluctuation (ALFF) values in the posterior cerebellar lobe and cerebellar tonsil following AC stimulation. This study suggests that rTMS enhances motor functions in SCA3 patients by modulating the excitability of specific brain regions and associated pathways, reinforcing the potential clinical utility of rTMS in SCA3 treatment. The Chinese Clinical Trial Registry identifier is ChiCTR1800020133.

9.
Cell Commun Signal ; 22(1): 343, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38907279

RESUMO

Mitochondria are central to endothelial cell activation and angiogenesis, with the RNA polymerase mitochondrial (POLRMT) serving as a key protein in regulating mitochondrial transcription and oxidative phosphorylation. In our study, we examined the impact of POLRMT on angiogenesis and found that its silencing or knockout (KO) in human umbilical vein endothelial cells (HUVECs) and other endothelial cells resulted in robust anti-angiogenic effects, impeding cell proliferation, migration, and capillary tube formation. Depletion of POLRMT led to impaired mitochondrial function, characterized by mitochondrial depolarization, oxidative stress, lipid oxidation, DNA damage, and reduced ATP production, along with significant apoptosis activation. Conversely, overexpressing POLRMT promoted angiogenic activity in the endothelial cells. In vivo experiments demonstrated that endothelial knockdown of POLRMT, by intravitreous injection of endothelial specific POLRMT shRNA adeno-associated virus, inhibited retinal angiogenesis. In addition, inhibiting POLRMT with a first-in-class inhibitor IMT1 exerted significant anti-angiogenic impact in vitro and in vivo. Significantly elevated expression of POLRMT was observed in the retinal tissues of streptozotocin-induced diabetic retinopathy (DR) mice. POLRMT endothelial knockdown inhibited pathological retinal angiogenesis and mitigated retinal ganglion cell (RGC) degeneration in DR mice. At last, POLRMT expression exhibited a substantial increase in the retinal proliferative membrane tissues of human DR patients. These findings collectively establish the indispensable role of POLRMT in angiogenesis, both in vitro and in vivo.


Assuntos
RNA Polimerases Dirigidas por DNA , Células Endoteliais da Veia Umbilical Humana , Mitocôndrias , Humanos , Animais , Camundongos , Mitocôndrias/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , RNA Polimerases Dirigidas por DNA/genética , Retinopatia Diabética/patologia , Retinopatia Diabética/metabolismo , Retinopatia Diabética/genética , Camundongos Endogâmicos C57BL , Proliferação de Células , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Masculino , Neovascularização Fisiológica/genética , Movimento Celular , Apoptose , Angiogênese
10.
Pediatr Res ; 2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39179877

RESUMO

BACKGROUND: We aimed to explore the differences and relationships in body composition, social function, and comorbidities between children with attention-deficit/hyperactivity disorder (ADHD) and subthreshold ADHD. METHODS: A case-control study was conducted to analyze the differences between children with ADHD and subthreshold ADHD. Logistic regression models were used to analyze the factors influencing social functional impairments and comorbidities. RESULTS: Children with ADHD and subthreshold ADHD had a higher fat mass index than healthy children (p < 0.05). The scores of all six social functional domains were higher in the subthreshold ADHD and ADHD groups than in the control group (p < 0.05). The prevalence of comorbidity was higher in children with subthreshold ADHD and ADHD compared to the control group (p < 0.05). Inattention and comorbid anxiety/depression increased the risk of functional impairments in children with ADHD (full syndrome/subthreshold), whereas a higher fat-free mass index reduced the risk. The severity of hyperactivity was associated with a higher risk of comorbidity in children with ADHD (full syndrome/subthreshold). CONCLUSION: Children with subthreshold ADHD and ADHD had more fat mass and higher rates of social functional impairments and comorbidities than healthy children. There were clinical correlations between body composition, social functional impairments, and comorbidities in ADHD. IMPACT: 1. Children with subthreshold ADHD and ADHD had higher fat mass levels than normal children. 2. The social function impairments and comorbidities of children with subthreshold ADHD were similar to those with ADHD. 3. Inattentiveness and anxiety/depression increased the risk of functional impairments in children with ADHD (full syndrome/subthreshold), while a higher fat-free mass index and skeletal muscle-to-body fat ratio reduced the risk.

11.
Biomacromolecules ; 25(7): 4374-4383, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38825770

RESUMO

Biomacromolecular condensates formed via phase separation establish compartments for the enrichment of specific compositions, which is also used as a biological tool to enhance molecule condensation, thereby increasing the efficiency of biological processes. Proteolysis-targeting chimeras (PROTACs) have been developed as powerful tools for targeted protein degradation in cells, offering a promising approach for therapies for different diseases. Herein, we introduce an intrinsically disordered region in the PROTAC (denoted PSETAC), which led to the formation of droplets of target proteins in the cells and increased degradation efficiency compared with PROTAC without phase separation. Further, using a nucleus targeting intrinsically disordered domain, the PSETAC was able to target and degrade nuclear-located proteins. Finally, we demonstrated intracellular delivery of PSETAC using lipid nanoparticle-encapsulated mRNA (mRNA-LNP) for the degradation of the endogenous target protein. This study established the PSETAC mRNA-LNP method as a potentially translatable, safe therapeutic strategy for the development of clinical applications based on PROTAC.


Assuntos
Proteólise , RNA Mensageiro , Proteólise/efeitos dos fármacos , Humanos , RNA Mensageiro/genética , Nanopartículas/química , Lipídeos/química , Células HeLa , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/metabolismo , Separação de Fases , Lipossomos
12.
Soft Matter ; 20(33): 6635-6647, 2024 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-39109438

RESUMO

Rapid adsorption of surfactants onto a freshly formed interface is vital for emulsification because emulsification is a competitive process occurring between the very short time span of interface formation and surfactant mass transport. The biosurfactant surfactin has been previously reported to reach adsorption equilibrium at the hydrophobic/hydrophilic interface within hundreds of milliseconds and rapidly reduce the interfacial tension compared to chemically synthesized surfactants. According to a prior study, surfactin is expected to exhibit good performance in stabilizing micro-droplets of oil within the aging time scale of milliseconds. Herein, the stabilities of micro-droplets of n-hexadecane in the presence of a biosurfactant, surfactin (C15-SFT), and a chemically synthesized surfactant, sodium cetyl benzene sulfonate (8-SCBS), were investigated using a microfluidic method. The coalescence frequency of micro-droplets, the evolution of micro-droplet size, and the coalescence time of micro-droplets were evaluated. The results indicated that C15-SFT exhibited superiority over 8-SCBS in stabilizing the micro-droplets of n-hexadecane. Biosurfactant C15-SFT effectively reduced the fusion probability between oil droplets and elongated the coalescence time compared to 8-SCBS, and these phenomena were obvious at a shorter aging time (150 ms) and lower surfactant concentration (0.1 × critical micelle concentration). The stabilities of micro-droplets increased with aging time and the bulk concentration of surfactants. Stable micro-droplets of n-hexadecane were formed in 1 × 10-4 mol L-1 C15-SFT solution at 600 ms aging time, and the bulk concentration was 1 × 10-3 mol L-1 in the case of 8-SCBS. The micro-droplets rarely coalesced in the presence of 1 × 10-4 mol L-1 C15-SFT after 600 ms aging time, but the micro-droplets in 1 × 10-4 mol L-1 8-SCBS coalesced frequently in the midstream and downstream of the coalescence chamber, and big droplets were dominant in the emulsion. The coalescence time of micro-droplets stabilized by C15-SFT was obviously longer than that of those stabilized by 8-SCBS under the same condition, indicating that the interfacial film formed by C15-SFT has much strength to resist coalescence during collisions. This work is helpful for understanding the activity of lipopeptides in the very short early stage of the emulsification process, laying the foundation for biosurfactant research in the fields of enhanced oil recovery, bioremediation of contaminated water or soil, etc.

13.
Acta Pharmacol Sin ; 45(6): 1130-1141, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38195693

RESUMO

Hepatocellular carcinoma (HCC) is one of the most common malignancy, presenting a formidable challenge to the medical community owing to its intricate pathogenic mechanisms. Although current prevention, surveillance, early detection, diagnosis, and treatment have achieved some success in preventing HCC and controlling overall disease mortality, the imperative to explore novel treatment modalities for HCC remains increasingly urgent. Epigenetic modification has emerged as pivotal factors in the etiology of cancer. Among these, RNA N6-methyladenosine (m6A) modification stands out as one of the most prevalent, abundant, and evolutionarily conserved post-transcriptional alterations in eukaryotes. The literature underscores that the dynamic and reversible nature of m6A modifications orchestrates the intricate regulation of gene expression, thereby exerting a profound influence on cell destinies. Increasing evidence has substantiated conspicuous fluctuations in m6A modification levels throughout the progression of HCC. The deliberate modulation of m6A modification levels through molecular biology and pharmacological interventions has been demonstrated to exert a discernible impact on the pathogenesis of HCC. In this review, we elucidate the multifaceted biological functions of m6A modifications in HCC, and concurrently advancing novel therapeutic strategies for the management of this malignancy.


Assuntos
Adenosina , Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/genética , Adenosina/análogos & derivados , Adenosina/metabolismo , Animais , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , RNA/metabolismo , RNA/genética
14.
World J Surg ; 48(2): 446-455, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38686786

RESUMO

BACKGROUND: The diseased bile duct in bilobar congenital biliary dilatation is extensive and often requires major hepatectomy or liver transplantation associated with a higher risk. We aimed to evaluate the safety and benefit of modified mesohepatectomy, in comparison with trisectionectomy, to treat bilobar congenital biliary dilatation. METHODS: This study included 28 patients with type IV and V bilobar congenital biliary dilatation. An innovative mesohepatectomy comprising the hepatectomy technique beyond the P/U point and bile duct shaping was applied to 14 patients to address the extensively diseased bile duct and difficulty in hepaticojejunostomy. Another 14 patients received trisectionectomy. The perioperative and long-term outcomes of these patients were compared. RESULTS: The ratio of residual liver volume to standard liver volume in the mesohepatectomy group was higher (78.68% vs. 40.90%, p = 0.005), while the resection rate of the liver parenchyma was lower (28.25% vs. 63.97%, p = 0.000), than that in trisectionectomy group. The mesohepatectomy group had a lower severe complication (>Clavein III, 0% vs. 57.70%, p = 0.019) and incidence of posthepatectomy liver failure (7.14% vs. 42.86%, p = 0.038). No significant difference was observed in blood loss and bile leakage (p > 0.05). All the patients in the mesohepatectomy group achieved optimal results in the long-term follow-up. CONCLUSIONS: mesohepatectomy provides an efficient treatment option for bilobar congenital biliary dilatation and can achieve radical resection, retain more liver parenchyma, and reduce the difficulty of hepaticojejunostomy, especially for patients that are not eligible for major hepatectomy and liver transplantation.


Assuntos
Hepatectomia , Humanos , Hepatectomia/métodos , Masculino , Feminino , Resultado do Tratamento , Estudos Retrospectivos , Dilatação Patológica/cirurgia , Lactente , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Pré-Escolar
15.
PLoS Genet ; 17(11): e1009898, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34784357

RESUMO

Increasing evidence points to the tight relationship between alternative splicing (AS) and the salt stress response in plants. However, the mechanisms linking these two phenomena remain unclear. In this study, we have found that Salt-Responsive Alternatively Spliced gene 1 (SRAS1), encoding a RING-Type E3 ligase, generates two splicing variants: SRAS1.1 and SRAS1.2, which exhibit opposing responses to salt stress. The salt stress-responsive AS event resulted in greater accumulation of SRAS1.1 and a lower level of SRAS1.2. Comprehensive phenotype analysis showed that overexpression of SRAS1.1 made the plants more tolerant to salt stress, whereas overexpression of SRAS1.2 made them more sensitive. In addition, we successfully identified the COP9 signalosome 5A (CSN5A) as the target of SRAS1. CSN5A is an essential player in the regulation of plant development and stress. The full-length SRAS1.1 promoted degradation of CSN5A by the 26S proteasome. By contrast, SRAS1.2 protected CSN5A by competing with SRAS1.1 on the same binding site. Thus, the salt stress-triggered AS controls the ratio of SRAS1.1/SRAS1.2 and switches on and off the degradation of CSN5A to balance the plant development and salt tolerance. Together, these results provide insights that salt-responsive AS acts as post-transcriptional regulation in mediating the function of E3 ligase.


Assuntos
Processamento Alternativo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Complexo do Signalossomo COP9/genética , Estresse Salino , Ubiquitina-Proteína Ligases/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Genes de Plantas , Isoformas de Proteínas/genética , Salinidade , Ubiquitina-Proteína Ligases/genética
16.
J Cell Mol Med ; 27(16): 2372-2384, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37400979

RESUMO

Metastasis is the primary cause of death of hepatocellular carcinoma (HCC), while the mechanism underlying this severe disease remains largely unclear. The Kruppel-like factor (KLF) family is one of the largest transcription factor families that control multiple physiologic and pathologic processes by governing the cellular transcriptome. To identify metastatic regulators of HCC, we conducted gene expression profiling on the MHCC97 cell series, a set of subclones of the original MHCC97 that was established by in vivo metastasis selection therefore harbouring differential metastatic capacities. We found that the expression of KLF9, a member of the KLF family, was dramatically repressed in the metastatic progeny clone of the MHCC97 cells. Functional studies revealed overexpression of KLF9 suppressed HCC migration in vitro and metastasis in vivo, while knockdown of KLF9 was sufficient to promote cell migration and metastasis accordingly. Mechanistically, we found the expression of KLF9 can reverse the pro-metastatic epithelial-mesenchymal transition (EMT) program via direct binding to the promoter regions of essential mesenchymal genes, thus repressing their expression. Interestingly, we further revealed that KLF9 was, in turn, directly suppressed by a mesenchymal transcription factor Slug, suggesting an intriguing negative feedback loop between KLF9 and the EMT program. Using clinical samples, we found that KLF9 was not only downregulated in HCC tissue compared to its normal counterparts but also further reduced in the HCC samples of whom had developed metastatic lesions. Together, we established a critical transcription factor that represses HCC metastasis, which is clinically and mechanically significant in HCC therapies.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Transição Epitelial-Mesenquimal/genética , Retroalimentação , Regulação Neoplásica da Expressão Gênica , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Neoplasias Hepáticas/patologia , Metástase Neoplásica , Fatores de Transcrição da Família Snail/metabolismo , Fatores de Transcrição/metabolismo
17.
J Neuroinflammation ; 20(1): 82, 2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36944982

RESUMO

BACKGROUND: Central post-stroke pain (CPSP) is an intractable and disabling central neuropathic pain that severely affects patients' lives, well-being, and socialization abilities. However, CPSP has been poorly studied mechanistically and its treatment remains challenging. Here, we used a rat model of CPSP induced by thalamic hemorrhage to investigate its underlying mechanisms and the effect of stellate ganglion block (SGB) on CPSP and emotional comorbidities. METHODS: Thalamic hemorrhage was produced by injecting collagenase IV into the ventral-posterolateral nucleus (VPL) of the right thalamus. The up-and-down method with von Frey hairs was used to measure the mechanical allodynia. Behavioral tests were carried out to examine depressive and anxiety-like behaviors including the open field test (OFT), elevated plus maze test (EPMT), novelty-suppressed feeding test (NSFT), and forced swim test (FST). The peri-thalamic lesion tissues were collected for immunofluorescence, western blotting, and enzyme-linked immunosorbent assay (ELISA). Genetic knockdown of thalamic hypoxia-inducible factor-1α (HIF-1α) and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) with microinjection of HIF-1α siRNA and NLRP3 siRNA into the VPL of thalamus were performed 3 days before collagenase injection into the same regions. Microinjection of lificiguat (YC-1) and MCC950 into the VPL of thalamus were administrated 30 min before the collagenase injection in order to inhibited HIF-1α and NLRP3 pharmacologically. Repetitive right SGB was performed daily for 5 days and laser speckle contrast imaging (LSCI) was conducted to examine cerebral blood flow. RESULTS: Thalamic hemorrhage caused persistent mechanical allodynia and anxiety- and depression-like behaviors. Accompanying the persistent mechanical allodynia, the expression of HIF-1α and NLRP3, as well as the activities of microglia and astrocytes in the peri-thalamic lesion sites, were significantly increased. Genetic knockdown of thalamic HIF-1α and NLRP3 significantly attenuated mechanical allodynia and anxiety- and depression-like behaviors following thalamic hemorrhage. Further studies revealed that intra-thalamic injection of YC-1, or MCC950 significantly suppressed the activation of microglia and astrocytes, the release of pro-inflammatory cytokines, the upregulation of malondialdehyde (MDA), and the downregulation of superoxide dismutase (SOD), as well as mechanical allodynia and anxiety- and depression-like behaviors following thalamic hemorrhage. In addition, repetitive ipsilateral SGB significantly restored the upregulated HIF-1α/NLRP3 signaling and the hyperactivated microglia and astrocytes following thalamic hemorrhage. The enhanced expression of pro-inflammatory cytokines and the oxidative stress in the peri-thalamic lesion sites were also reversed by SGB. Moreover, LSCI showed that repetitive SGB significantly increased cerebral blood flow following thalamic hemorrhage. Most strikingly, SGB not only prevented, but also reversed the development of mechanical allodynia and anxiety- and depression-like behaviors induced by thalamic hemorrhage. However, pharmacological activation of thalamic HIF-1α and NLRP3 with specific agonists significantly eliminated the therapeutic effects of SGB on mechanical allodynia and anxiety- and depression-like behaviors following thalamic hemorrhage. CONCLUSION: This study demonstrated for the first time that SGB could improve CPSP with comorbid anxiety and depression by increasing cerebral blood flow and inhibiting HIF-1α/NLRP3 inflammatory signaling.


Assuntos
Acidente Vascular Cerebral Hemorrágico , Neuralgia , Acidente Vascular Cerebral , Ratos , Animais , Hiperalgesia/tratamento farmacológico , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Acidente Vascular Cerebral Hemorrágico/complicações , Acidente Vascular Cerebral Hemorrágico/patologia , Depressão/etiologia , Depressão/terapia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Gânglio Estrelado/metabolismo , Gânglio Estrelado/patologia , Ratos Sprague-Dawley , Acidente Vascular Cerebral/patologia , Tálamo/metabolismo , Hemorragia Cerebral/patologia , Neuralgia/metabolismo , Ansiedade , Colagenases/metabolismo , Citocinas/metabolismo
18.
Brief Bioinform ; 22(6)2021 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-34180984

RESUMO

Targeting the interaction between severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2)-receptor-binding domain (RBD) and angiotensin-converting enzyme 2 (ACE2) is believed to be an effective strategy for drug design to inhibit the infection of SARS-CoV-2. Herein, several ultrashort peptidase inhibitors against the RBD-ACE2 interaction were obtained by a computer-aided approach based on the RBD-binding residues on the protease domain (PD) of ACE2. The designed peptides were tested on a model coronavirus GX_P2V, which has 92.2 and 86% amino acid identity to the SARS-CoV-2 spike protein and RBD, respectively. Molecular dynamics simulations and binding free energy analysis predicted a potential binding pocket on the RBD of the spike protein, and this was confirmed by the specifically designed peptides SI5α and SI5α-b. They have only seven residues, showing potent antiviral activity and low cytotoxicity. Enzyme-linked immunosorbent assay result also confirmed their inhibitory ability against the RBD-ACE2 interaction. The ultrashort peptides are promising precursor molecules for the drug development of Corona Virus Disease 2019, and the novel binding pocket on the RBD may be helpful for the design of RBD inhibitors or antibodies against SARS-CoV-2.


Assuntos
Enzima de Conversão de Angiotensina 2/química , Tratamento Farmacológico da COVID-19 , Peptídeos/química , SARS-CoV-2/efeitos dos fármacos , Glicoproteína da Espícula de Coronavírus/antagonistas & inibidores , Enzima de Conversão de Angiotensina 2/antagonistas & inibidores , Enzima de Conversão de Angiotensina 2/genética , Antivirais/química , Sítios de Ligação/efeitos dos fármacos , COVID-19/genética , COVID-19/virologia , Desenho de Fármacos , Humanos , Simulação de Dinâmica Molecular , Peptídeos/genética , Peptídeos/uso terapêutico , Ligação Proteica/efeitos dos fármacos , Domínios Proteicos/efeitos dos fármacos , SARS-CoV-2/patogenicidade , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética
19.
New Phytol ; 240(2): 710-726, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37547968

RESUMO

MicroRNAs (miRNAs) play crucial roles in regulating plant development and stress responses. However, the functions and mechanism of intronic miRNAs in plants are poorly understood. This study reports a stress-responsive RNA splicing mechanism for intronic miR400 production, whereby miR400 modulates reactive oxygen species (ROS) accumulation and improves plant tolerance by downregulating its target expression. To monitor the intron splicing events, we used an intronic miR400 splicing-dependent luciferase transgenic line. Luciferase activity was observed to decrease after high cadmium concentration treatment due to the retention of the miR400-containing intron, which inhibited the production of mature miR400. Furthermore, we demonstrated that under Cd treatments, Pentatricopeptide Repeat Protein 1 (PPR1), the target of miR400, acts as a positive regulator by inducing ROS accumulation. Ppr1 mutation affected the Complex III activity in the electron transport chain and RNA editing of the mitochondrial gene ccmB. This study illustrates intron splicing as a key step in intronic miR400 production and highlights the function of intronic miRNAs as a 'signal transducer' in enhancing plant stress tolerance.


Assuntos
Arabidopsis , MicroRNAs , MicroRNAs/genética , MicroRNAs/metabolismo , Arabidopsis/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Íntrons/genética , Splicing de RNA/genética , Regulação da Expressão Gênica de Plantas
20.
Mol Psychiatry ; 27(2): 896-906, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34697452

RESUMO

Neuroplasticity in the medial prefrontal cortex (mPFC) is essential for fear extinction, the process of which forms the basis of the general therapeutic process used to treat human fear disorders. However, the underlying molecules and local circuit elements controlling neuronal activity and concomitant induction of plasticity remain unclear. Here we show that sustained plasticity of the parvalbumin (PV) neuronal network in the infralimbic (IL) mPFC is required for fear extinction in adult male mice and identify the involvement of neuregulin 1-ErbB4 signalling in PV network plasticity-mediated fear extinction. Moreover, regulation of fear extinction by basal medial amygdala (BMA)-projecting IL neurons is dependent on PV network configuration. Together, these results uncover the local molecular circuit mechanisms underlying mPFC-mediated top-down control of fear extinction, suggesting alterative therapeutic approaches to treat fear disorders.


Assuntos
Extinção Psicológica , Medo , Animais , Extinção Psicológica/fisiologia , Medo/fisiologia , Masculino , Camundongos , Neuregulina-1 , Plasticidade Neuronal/fisiologia , Parvalbuminas , Córtex Pré-Frontal/fisiologia , Receptor ErbB-4
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