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1.
Cell ; 166(3): 716-728, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27426949

RESUMO

Fear behaviors are regulated by adaptive mechanisms that dampen their expression in the absence of danger. By studying circuits and the molecular mechanisms underlying this adaptive response, we show that cholinergic neurons of the medial habenula reduce fear memory expression through GABAB presynaptic excitation. Ablating these neurons or inactivating their GABAB receptors impairs fear extinction in mice, whereas activating the neurons or their axonal GABAB receptors reduces conditioned fear. Although considered exclusively inhibitory, here, GABAB mediates excitation by amplifying presynaptic Ca(2+) entry through Cav2.3 channels and potentiating co-release of glutamate, acetylcholine, and neurokinin B to excite interpeduncular neurons. Activating the receptors for these neurotransmitters or enhancing neurotransmission with a phosphodiesterase inhibitor reduces fear responses of both wild-type and GABAB mutant mice. We identify the role of an extra-amygdalar circuit and presynaptic GABAB receptors in fear control, suggesting that boosting neurotransmission in this pathway might ameliorate some fear disorders.


Assuntos
Neurônios Colinérgicos/metabolismo , Medo/fisiologia , Habenula/fisiologia , Memória/fisiologia , Receptores de GABA-B/metabolismo , Animais , Cálcio/metabolismo , Canais de Cálcio/metabolismo , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Vias Neurais , Neurotransmissores/metabolismo , Transmissão Sináptica
2.
Nature ; 629(8013): 893-900, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38632402

RESUMO

The blood-brain barrier (BBB) protects the central nervous system from infections or harmful substances1; its impairment can lead to or exacerbate various diseases of the central nervous system2-4. However, the mechanisms of BBB disruption during infection and inflammatory conditions5,6 remain poorly defined. Here we find that activation of the pore-forming protein GSDMD by the cytosolic lipopolysaccharide (LPS) sensor caspase-11 (refs. 7-9), but not by TLR4-induced cytokines, mediates BBB breakdown in response to circulating LPS or during LPS-induced sepsis. Mice deficient in the LBP-CD14 LPS transfer and internalization pathway10-12 resist BBB disruption. Single-cell RNA-sequencing analysis reveals that brain endothelial cells (bECs), which express high levels of GSDMD, have a prominent response to circulating LPS. LPS acting on bECs primes Casp11 and Cd14 expression and induces GSDMD-mediated plasma membrane permeabilization and pyroptosis in vitro and in mice. Electron microscopy shows that this features ultrastructural changes in the disrupted BBB, including pyroptotic endothelia, abnormal appearance of tight junctions and vasculature detachment from the basement membrane. Comprehensive mouse genetic analyses, combined with a bEC-targeting adeno-associated virus system, establish that GSDMD activation in bECs underlies BBB disruption by LPS. Delivery of active GSDMD into bECs bypasses LPS stimulation and opens the BBB. In CASP4-humanized mice, Gram-negative Klebsiella pneumoniae infection disrupts the BBB; this is blocked by expression of a GSDMD-neutralizing nanobody in bECs. Our findings outline a mechanism for inflammatory BBB breakdown, and suggest potential therapies for diseases of the central nervous system associated with BBB impairment.


Assuntos
Barreira Hematoencefálica , Encéfalo , Células Endoteliais , Gasderminas , Inflamação , Animais , Feminino , Humanos , Masculino , Camundongos , Membrana Basal/metabolismo , Membrana Basal/ultraestrutura , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Barreira Hematoencefálica/ultraestrutura , Barreira Hematoencefálica/virologia , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/ultraestrutura , Caspases Iniciadoras/metabolismo , Dependovirus , Células Endoteliais/metabolismo , Células Endoteliais/ultraestrutura , Gasderminas/antagonistas & inibidores , Gasderminas/metabolismo , Inflamação/patologia , Inflamação/metabolismo , Klebsiella pneumoniae/fisiologia , Receptores de Lipopolissacarídeos/metabolismo , Lipopolissacarídeos/sangue , Lipopolissacarídeos/farmacologia , Camundongos Endogâmicos C57BL , Piroptose , Sepse/metabolismo , Sepse/patologia , Sepse/microbiologia , Análise de Célula Única , Junções Íntimas/metabolismo , Junções Íntimas/ultraestrutura
3.
Chem Rev ; 124(9): 5617-5667, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38661498

RESUMO

The quest to identify precious metal free hydrogen evolution reaction catalysts has received unprecedented attention in the past decade. In this Review, we focus our attention to recent developments in precious metal free hydrogen evolution reactions in acidic and alkaline electrolyte owing to their relevance to commercial and near-commercial low-temperature electrolyzers. We provide a detailed review and critical analysis of catalyst activity and stability performance measurements and metrics commonly deployed in the literature, as well as review best practices for experimental measurements (both in half-cell three-electrode configurations and in two-electrode device testing). In particular, we discuss the transition from laboratory-scale hydrogen evolution reaction (HER) catalyst measurements to those in single cells, which is a critical aspect crucial for scaling up from laboratory to industrial settings but often overlooked. Furthermore, we review the numerous catalyst design strategies deployed across the precious metal free HER literature. Subsequently, we showcase some of the most commonly investigated families of precious metal free HER catalysts; molybdenum disulfide-based, transition metal phosphides, and transition metal carbides for acidic electrolyte; nickel molybdenum and transition metal phosphides for alkaline. This includes a comprehensive analysis comparing the HER activity between several families of materials highlighting the recent stagnation with regards to enhancing the intrinsic activity of precious metal free hydrogen evolution reaction catalysts. Finally, we summarize future directions and provide recommendations for the field in this area of electrocatalysis.

4.
Mol Cell ; 71(4): 606-620.e7, 2018 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-30118680

RESUMO

Metformin has been reported to possess antitumor activity and maintain high cytotoxic T lymphocyte (CTL) immune surveillance. However, the functions and detailed mechanisms of metformin's role in cancer immunity are not fully understood. Here, we show that metformin increases CTL activity by reducing the stability and membrane localization of programmed death ligand-1 (PD-L1). Furthermore, we discover that AMP-activated protein kinase (AMPK) activated by metformin directly phosphorylates S195 of PD-L1. S195 phosphorylation induces abnormal PD-L1 glycosylation, resulting in its ER accumulation and ER-associated protein degradation (ERAD). Consistently, tumor tissues from metformin-treated breast cancer patients exhibit reduced PD-L1 levels with AMPK activation. Blocking the inhibitory signal of PD-L1 by metformin enhances CTL activity against cancer cells. Our findings identify a new regulatory mechanism of PD-L1 expression through the ERAD pathway and suggest that the metformin-CTLA4 blockade combination has the potential to increase the efficacy of immunotherapy.


Assuntos
Antineoplásicos/farmacologia , Antígeno B7-H1/genética , Antígeno CTLA-4/genética , Regulação Neoplásica da Expressão Gênica , Hipoglicemiantes/farmacologia , Metformina/farmacologia , Proteínas Quinases Ativadas por AMP/genética , Proteínas Quinases Ativadas por AMP/imunologia , Animais , Antígeno B7-H1/imunologia , Antígeno CTLA-4/imunologia , Linhagem Celular Tumoral , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/genética , Retículo Endoplasmático/metabolismo , Degradação Associada com o Retículo Endoplasmático , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Feminino , Glicosilação , Humanos , Glândulas Mamárias Humanas/citologia , Glândulas Mamárias Humanas/efeitos dos fármacos , Glândulas Mamárias Humanas/imunologia , Melanoma Experimental/tratamento farmacológico , Melanoma Experimental/genética , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos NOD , Fosforilação , Serina/metabolismo , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/efeitos dos fármacos , Linfócitos T Citotóxicos/imunologia
5.
Mol Cell ; 69(2): 279-291.e5, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29351847

RESUMO

Sustained energy starvation leads to activation of AMP-activated protein kinase (AMPK), which coordinates energy status with numerous cellular processes including metabolism, protein synthesis, and autophagy. Here, we report that AMPK phosphorylates the histone methyltransferase EZH2 at T311 to disrupt the interaction between EZH2 and SUZ12, another core component of the polycomb repressive complex 2 (PRC2), leading to attenuated PRC2-dependent methylation of histone H3 at Lys27. As such, PRC2 target genes, many of which are known tumor suppressors, were upregulated upon T311-EZH2 phosphorylation, which suppressed tumor cell growth both in cell culture and mouse xenografts. Pathologically, immunohistochemical analyses uncovered a positive correlation between AMPK activity and pT311-EZH2, and higher pT311-EZH2 correlates with better survival in both ovarian and breast cancer patients. Our finding suggests that AMPK agonists might be promising sensitizers for EZH2-targeting cancer therapies.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Animais , Carcinogênese/genética , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Metilação de DNA , Proteínas de Ligação a DNA/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/fisiologia , Epigênese Genética , Feminino , Histonas/metabolismo , Humanos , Camundongos , Proteínas de Neoplasias , Proteínas Nucleares/metabolismo , Oncogenes , Neoplasias Ovarianas/metabolismo , Fosforilação , Complexo Repressor Polycomb 2/metabolismo , Complexo Repressor Polycomb 2/fisiologia , Fatores de Transcrição , Regulação para Cima
6.
PLoS Genet ; 19(11): e1011031, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37956204

RESUMO

PIWI proteins and their associated piRNAs act to silence transposons and promote gametogenesis. Murine PIWI proteins MIWI, MILI, and MIWI2 have multiple arginine and glycine (RG)-rich motifs at their N-terminal domains. Despite being known as docking sites for the TDRD family proteins, the in vivo regulatory roles for these RG motifs in directing PIWI in piRNA biogenesis and spermatogenesis remain elusive. To investigate the functional significance of RG motifs in mammalian PIWI proteins in vivo, we genetically engineered an arginine to lysine (RK) point mutation of a conserved N-terminal RG motif in MIWI in mice. We show that this tiny MIWI RG motif is indispensable for piRNA biogenesis and male fertility. The RK mutation in the RG motif disrupts MIWI-TDRKH interaction and impairs enrichment of MIWI to the intermitochondrial cement (IMC) for efficient piRNA production. Despite significant overall piRNA level reduction, piRNA trimming and maturation are not affected by the RK mutation. Consequently, MiwiRK mutant mice show chromatoid body malformation, spermatogenic arrest, and male sterility. Surprisingly, LINE1 transposons are effectively silenced in MiwiRK mutant mice, indicating a LINE1-independent cause of germ cell arrest distinctive from Miwi knockout mice. These findings reveal a crucial function of the RG motif in directing PIWI proteins to engage in efficient piRNA production critical for germ cell progression and highlight the functional importance of the PIWI N-terminal motifs in regulating male fertility.


Assuntos
RNA de Interação com Piwi , Testículo , Masculino , Camundongos , Animais , Testículo/metabolismo , RNA Interferente Pequeno/metabolismo , Espermatogênese/genética , Proteínas/metabolismo , Camundongos Knockout , Arginina/metabolismo , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Mamíferos/genética
7.
Am J Transplant ; 2024 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-38648890

RESUMO

The activation of innate immunity following transplantation has been identified as a crucial factor in allograft inflammation and rejection. However, the role of cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)/stimulator of interferon genes (STING) signaling-mediated innate immunity in the pathogenesis of allograft rejection remains unclear. Utilizing a well-established murine model of corneal transplantation, we demonstrated increased expression of cGAS and STING in rejected-corneal allografts compared with syngeneic (Syn) and normal (Nor) corneas, along with significant activation of the cGAS/STING pathway, as evidenced by the enhanced phosphorylation of TANK-binding kinase 1and interferon regulatory factor 3. Pharmacological and genetic inhibition of cGAS/STING signaling markedly delayed corneal transplantation rejection, resulting in prolonged survival time and reduced inflammatory infiltration. Furthermore, we observed an increase in the formation of neutrophil extracellular traps (NETs) in rejected allografts, and the inhibition of NET formation through targeting peptidylarginine deiminase 4 and DNase I treatment significantly alleviated immune rejection and reduced cGAS/STING signaling activity. Conversely, subconjunctival injection of NETs accelerated corneal transplantation rejection and enhanced the activation of the cGAS/STING pathway. Collectively, these findings demonstrate that NETs contribute to the exacerbation of allograft rejection via cGAS/STING signaling, highlighting the targeting of the NETs/cGAS/STING signaling pathway as a potential strategy for prolonging allograft survival.

8.
Plant Physiol ; 193(1): 448-465, 2023 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-37217835

RESUMO

Bud dormancy is crucial for winter survival and is characterized by the inability of the bud meristem to respond to growth-promotive signals before the chilling requirement (CR) is met. However, our understanding of the genetic mechanism regulating CR and bud dormancy remains limited. This study identified PpDAM6 (DORMANCY-ASSOCIATED MADS-box) as a key gene for CR using a genome-wide association study analysis based on structural variations in 345 peach (Prunus persica (L.) Batsch) accessions. The function of PpDAM6 in CR regulation was demonstrated by transiently silencing the gene in peach buds and stably overexpressing the gene in transgenic apple (Malus × domestica) plants. The results showed an evolutionarily conserved function of PpDAM6 in regulating bud dormancy release, followed by vegetative growth and flowering, in peach and apple. The 30-bp deletion in the PpDAM6 promoter was substantially associated with reducing PpDAM6 expression in low-CR accessions. A PCR marker based on the 30-bp indel was developed to distinguish peach plants with non-low and low CR. Modification of the H3K27me3 marker at the PpDAM6 locus showed no apparent change across the dormancy process in low- and non-low- CR cultivars. Additionally, H3K27me3 modification occurred earlier in low-CR cultivars on a genome-wide scale. PpDAM6 could mediate cell-cell communication by inducing the expression of the downstream genes PpNCED1 (9-cis-epoxycarotenoid dioxygenase 1), encoding a key enzyme for ABA biosynthesis, and CALS (CALLOSE SYNTHASE), encoding callose synthase. We shed light on a gene regulatory network formed by PpDAM6-containing complexes that mediate CR underlying dormancy and bud break in peach. A better understanding of the genetic basis for natural variations of CR can help breeders develop cultivars with different CR for growing in different geographical regions.


Assuntos
Malus , Prunus persica , Prunus , Prunus persica/genética , Prunus persica/metabolismo , Prunus/genética , Prunus/metabolismo , Histonas/metabolismo , Estudo de Associação Genômica Ampla , Malus/genética , Regulação da Expressão Gênica de Plantas , Dormência de Plantas/genética
9.
Cytokine ; 175: 156444, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38150791

RESUMO

Head and neck squamous cell carcinoma (HNSCC) is the most common malignancy of the head and neck epidermis. Accumulating long non-coding RNAs (lncRNAs) have been proven to be involved in the occurrence and development of HNSCC. LncRNA long intergenic non-protein coding RNA 491 (LINC00491) has been confirmed to regulate the progression of some cancers. In our study, we aimed to explore the potential biological function of LINC00491 and expound the regulatory mechanism by which LINC00491 affects the progression of HNSCC. RT-qPCR was utilized to analyze the expression of LINC00491 in HNSCC cell lines and the normal cell line. Functionally, we carried out a series of assays to measure cell proliferation, apoptosis, migration and invasion, such as EdU assay, colony formation, wound healing and western blot assays. Also, mechanism assays including RNA pull down and RIP were also implemented to investigate the interaction of LINC00491 and RNAs. As a result, we discovered that LINC00491 was highly expressed in HNSCC cells. In addition, LINC00491 depletion suppressed cell proliferation, migration and EMT process. Furthermore, we discovered that LINC00491 could bind to miR-508-3p. MiR-508-3p overexpression can restrain HNSCC cell growth. Importantly, miR-508-3p can target SATB homeobox 1 (SATB1) in HNSCC cells. Further, Wnt signaling pathway was proved to be activated by LINC00491 through SATB1 in HNSCC cells. In a word, LINC00491 accelerated HNSCC progression through regulating miR-508-3p/SATB1 axis and activating Wnt signaling pathway.


Assuntos
Neoplasias de Cabeça e Pescoço , Proteínas de Ligação à Região de Interação com a Matriz , MicroRNAs , RNA Longo não Codificante , Humanos , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/genética , Proteínas de Ligação à Região de Interação com a Matriz/genética , Proteínas de Ligação à Região de Interação com a Matriz/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Fatores de Transcrição/metabolismo , Via de Sinalização Wnt/genética
10.
Phys Rev Lett ; 132(19): 190801, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38804925

RESUMO

Fidelity estimation is an important technique for evaluating prepared quantum states in noisy quantum devices. A recent theoretical work proposed a frugal approach called neural quantum fidelity estimation (NQFE) [X. Zhang et al., Phys. Rev. Lett. 127, 130503 (2021).PRLTAO0031-900710.1103/PhysRevLett.127.130503]. While this requires a much smaller number of measurement operators than full quantum state tomography, it uses a weight-based floating measurement strategy that predetermines the top global Pauli operators that contribute the most to the fidelity and uses discrete fidelity intervals as predictions. In this Letter, we develop a measurement-fixed NQFE based on a transformer model which requires less measurement cost and can output continuous estimates of fidelity. Here we further experimentally apply the NQFE in a realistic situation using a nuclear spin quantum processor. We prepare the ground states of local Hamiltonians and arbitrary states and investigate how to estimate their fidelity with reference states, and we compare the fidelity estimation strategy with our and the original NQFE to conventional tomography. It is shown that NQFE can estimate the fidelity with comparable accuracy to the tomography approach. In the future, NQFE will become an important tool for benchmarking quantum states ahead of the advent of well-trusted fault-tolerant quantum computers.

11.
Exp Eye Res ; 245: 109971, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38871165

RESUMO

PURPOSE: This study aims to reveal the immunopathogenesis of the high-risk corneal transplantation using a comparative proteomic approach. METHODS: The immunological properties of ocular tissues (including corneal grafts, aqueous humour, and iris-ciliary body) were analysed using a high-risk rabbit corneal transplantation model employing a comparative proteomic approach. RESULTS: The corneal grafts revealed a dramatic increase in the immune response both at the early (postoperative day 7) and rejection stages, along with the appearance of transplantation stress-induced cellular senescence in the early stage. The aqueous humour (AH) displayed persistent pathological alterations, indicated by the significant enrichment of complement and coagulation cascades pathway in the early stage and interleukin (IL)-17 signalling pathway in the rejection stage. More surprisingly, the pronounced elevation of immune response was also observed in the iris-ciliary body (I-CB) tissues at the early and rejection stages. The enriched immune-related pathways were associated with antigen processing and presentation, complement and coagulation cascades, and IL-17 signalling pathway. Furthermore, proteomic analysis revealed that the implantation of Cyclosporine A drug delivery system (CsA-DDS) into the anterior chamber obviously mitigated corneal transplantation rejection by inhibiting immunoreaction both in the corneal grafts and I-CB tissues. CONCLUSION: The results highlighted the involvement of intraocular immunity both in the grafts and I-CB tissues during corneal transplantation rejection, further suggesting the anterior chamber as an optimal drug-delivery site for its treatment.

12.
Mol Cell Biochem ; 479(1): 63-72, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36988778

RESUMO

Severe hemorrhage shock and resuscitation (HSR) has been reported to induce myocardial ischemia-reperfusion injury (MIRI), resulting in a poor prognosis. Hirudin, an effective thrombin inhibitor, can offer protection against MIRI. This study aimed to determine if hirudin administration ameliorates HSR-induced MIRI and the underlying mechanism. A rat model of HSR was established by bleeding rats to a mean arterial blood pressure of 30-35 mmHg for 45 min and then resuscitating them with all the shed blood through the left femoral vein. After HSR, 1 mg/kg of hirudin was administrated immediately. At 24 h after HSR, the cardiac injury was assessed using serum CK-MB, cTnT, hematoxylin-eosin (HE) staining, echocardiography, M1-polarized macrophages, and pyroptosis-associated factors, including cleaved caspase-1, Gasdermin D (GSDMD) N-terminal, IL-1ß, and IL-18 were measured by immunofluorescence and western blot assays. Nigericin, a unique agonist, was utilized to evaluate the responsibilities of NLRP3 signaling. Under the HSR condition, rats exhibited a significant increase in myocardial injury score, an elevation of serum cTnT, CK-MB levels, an aggrandization of M1-polarized macrophages, an upregulation of pyroptosis-associated factors, including cleaved caspase-1, GSDMD N-terminal, IL-1ß, and IL-18, but a significant decrease in left ventricular ejection fraction (EF%) and a reduction of left ventricular fractional shortening (FS%), while hirudin administration partially restored the changes. However, the NLRP3 agonist nigericin reversed the cardioprotective effects of hirudin. We determined the cardioprotective effects of hirudin against HSR-induced MIRI. The mechanism may involve the inhibition of NLRP3-induced pyroptosis.


Assuntos
Traumatismo por Reperfusão Miocárdica , Choque Hemorrágico , Ratos , Animais , Traumatismo por Reperfusão Miocárdica/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Interleucina-18 , Hirudinas/farmacologia , Choque Hemorrágico/metabolismo , Volume Sistólico , Nigericina/farmacologia , Função Ventricular Esquerda , Caspase 1/metabolismo , Transdução de Sinais
13.
J Org Chem ; 89(5): 3383-3389, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38364205

RESUMO

In this paper, a mild strategy for the oxidative cleavage of carbon-carbon bonds catalyzed by Lewis acid was developed in air condition at room temperature. Under such conditions, the bis-carbonyl compounds 3 were directly afforded from the reaction of D-ribose tosylate 1 and aniline in excellent yields through the oxidative cleavage of the key intermediate iminium-ion A and its tautomer enamine B. A series of N-arylated lactam-type iminosugars 5 were then successfully obtained by removing the isopropylidene group from 3 with the aid of the condensation agent DCC. Additionally, reduction of A and the removal of the isopropylidene group could provide N-arylated iminosugars 4. This strategy enables the oxidative cleavage of carbon-carbon bonds under mild conditions and facilitates the synthesis of the novel iminosugars with potent biological activity.

14.
Cell Biol Int ; 2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-38922770

RESUMO

Oxidative stress plays a pivotal role in the development of diabetic cardiomyopathy (DCM). Previous studies have revealed that inhibition of mitochondrial fission suppressed oxidative stress and alleviated mitochondrial dysfunction and cardiac dysfunction in diabetic mice. However, no research has confirmed whether mitochondria fission accentuates hyperglycemia-induced cardiomyoblast oxidative stress through regulating fatty acid oxidation (FAO). We used H9c2 cardiomyoblasts exposed to high glucose (HG) 33 mM to simulate DCM in vitro. Excessive mitochondrial fission, poor cell viability, and lipid accumulation were observed in hyperglycemia-induced H9c2 cardiomyoblasts. Also, the cells were led to oxidative stress injury, lower adenosine triphosphate (ATP) levels, and apoptosis. Dynamin-related protein 1 (Drp1) short interfering RNA (siRNA) decreased targeted marker expression, inhibited mitochondrial fragmentation and lipid accumulation, suppressed oxidative stress, reduced cardiomyoblast apoptosis, and improved cell viability and ATP levels in HG-exposed H9c2 cardiomyoblasts, but not in carnitine palmitoyltransferase 1 (CPT1) inhibitor etomoxir treatment cells. We also found subcellular localization of CPT1 on the mitochondrial membrane, FAO, and levels of nicotinamide adenine dinucleotide phosphate (NADPH) were suppressed after exposure to HG treatment, whereas Drp1 siRNA normalized mitochondrial CPT1, FAO, and NADPH. However, the blockade of FAO with etomoxir abolished the above effects of Drp1 siRNA in hyperglycemia-induced H9c2 cardiomyoblasts. The preservation of mitochondrial function through the Drp1/CPT1/FAO pathway is the potential mechanism of inhibited mitochondria fission in attenuating oxidative stress injury of hyperglycemia-induced H9c2 cardiomyoblasts.

15.
Inorg Chem ; 63(1): 593-601, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-38103019

RESUMO

In nature, biological nitrogen fixation is accomplished through the π-back-bonding mechanism of nitrogenase, which poses significant challenges for mimic artificial systems, thanks to the activation barrier associated with the N≡N bond. Consequently, this motivates us to develop efficient and reusable photocatalysts for artificial nitrogen fixation under mild conditions. We employ a charge-assisted self-assembly process toward encapsulating one polyoxometalate (POM) within a dehydrated Zr-based metal-organic framework (d-UiO-66) exhibiting nitrogen photofixation activities, thereby constructing an enzyme-mimicking photocatalyst. The dehydration of d-UiO-66 is favorable for facilitating nitrogen chemisorption and activation via the unpaired d-orbital electron at the [Zr6O6] cluster. The incorporation of POM guests enhanced the charge separation in the composites, thereby facilitating the transfer of photoexcited electrons into the π* antibonding orbital of chemisorbed N2 for efficient nitrogen fixation. Simultaneously, the catalytic efficiency of SiW9Fe3@d-UiO-66 is enhanced by 9.0 times compared to that of d-UiO-66. Moreover, SiW9Fe3@d-UiO-66 exhibits an apparent quantum efficiency (AQE) of 0.254% at 550 nm. The tactics of "working-in-tandem" achieved by POMs and d-UiO-66 are extremely vital for enhancing artificial ammonia synthesis. This study presents a paradigm for the development of an efficient artificial catalyst for nitrogen photofixation, aiming to mimic the process of biological nitrogen fixation.

16.
Plant Cell Rep ; 43(3): 81, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418607

RESUMO

KEY MESSAGE: Cathepsin B plays an important role that degrades the Rubisco large subunit RbcL in freezing stress. Programmed cell death (PCD) has been well documented in both development and in response to environmental stresses in plants, however, PCD induced by freezing stress and its molecular mechanisms remain poorly understood. In the present study, we characterized freezing-induced PCD and explored its mechanisms in Arabidopsis. PCD induced by freezing stress was similar to that induced by other stresses and senescence in Arabidopsis plants with cold acclimation. Inhibitor treatment assays and immunoblotting indicated that cathepsin B mainly contributed to increased caspase-3-like activity during freezing-induced PCD. Cathepsin B was involved in freezing-induced PCD and degraded the large subunit, RbcL, of Rubisco. Our results demonstrate an essential regulatory mechanism of cathepsin B for Rubisco degradation in freezing-induced PCD, improving our understanding of freezing-induced cell death and nitrogen and carbohydrate remobilisation in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Catepsina B/metabolismo , Congelamento , Ribulose-Bifosfato Carboxilase/metabolismo , Apoptose , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo
17.
Ecotoxicol Environ Saf ; 274: 116203, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38479313

RESUMO

PCDD/Fs are dioxins produced by waste incineration and pose risks to human health. We aimed to detail the health risks of airborne and soil PCDD/Fs near a municipal solid-waste incinerator (MSWI) for the surrounding population and develop a new model that improves upon existing methods. Thus, we conducted field sampling and then investigated a MSWI in the Pearl River Delta (2016-2018). Our results showed that the carcinogenic and non-carcinogenic risk values of PCDD/Fs exposed to residents in nearby areas were acceptable, with hazard index (HI) values lower than 1.0 and a total carcinogenic risk lower than 1.0E-6. Notably, the results raised concerns regarding higher non-carcinogenic risks in children than in adults. Comparative analysis of the frequency accumulation diagram, accumulated probability risk, and the absolute value of error (δ) between the 95% confidence interval (CI) and the 90% CI of the Monte Carlo stochastic simulation-triangular fuzzy number (MCSS-TFN) and the MCSS model, respectively, demonstrated that the MCSS-TFN exhibited less uncertainty than the MCSS model, regardless of the health risk value of PCDD/Fs in ambient air or in soil. This observation underscores the superiority of the MCSS-TFN model over other models in assessing the health risks associated with PCDD/Fs in situations with limited data. Our new method overcomes the limited dataset size and high uncertainty in assessing the health risks of dioxin substances, providing a more comprehensive understanding of their associated health risks than MCSS models.


Assuntos
Poluentes Atmosféricos , Dioxinas , Dibenzodioxinas Policloradas , Adulto , Criança , Humanos , Resíduos Sólidos , Monitoramento Ambiental/métodos , Dibenzodioxinas Policloradas/toxicidade , Dibenzodioxinas Policloradas/análise , Dibenzofuranos , Poluentes Atmosféricos/análise , Incineração , Dioxinas/toxicidade , Medição de Risco , Dibenzofuranos Policlorados/análise , Solo
18.
Sensors (Basel) ; 24(5)2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38474973

RESUMO

This paper considers the interactive effects between the ego vehicle and other vehicles in a dynamic driving environment and proposes an autonomous vehicle lane-changing behavior decision-making and trajectory planning method based on graph convolutional networks (GCNs) and multi-segment polynomial curve optimization. Firstly, hierarchical modeling is applied to the dynamic driving environment, aggregating the dynamic interaction information of driving scenes in the form of graph-structured data. Graph convolutional neural networks are employed to process interaction information and generate ego vehicle's driving behavior decision commands. Subsequently, collision-free drivable areas are constructed based on the dynamic driving scene information. An optimization-based multi-segment polynomial curve trajectory planning method is employed to solve the optimization model, obtaining collision-free motion trajectories satisfying dynamic constraints and efficiently completing the lane-changing behavior of the vehicle. Finally, simulation and on-road vehicle experiments are conducted for the proposed method. The experimental results demonstrate that the proposed method outperforms traditional decision-making and planning methods, exhibiting good robustness, real-time performance, and strong scenario generalization capabilities.

19.
Zhongguo Zhong Yao Za Zhi ; 49(9): 2478-2488, 2024 May.
Artigo em Zh | MEDLINE | ID: mdl-38812147

RESUMO

In order to analyze the similarities and differences of chemical compositions between the roots and stems and leaves of Isodon japonicus(IJ), this study utilized UPLC-Q-TOF-MS technology to systematically characterize its chemical compositions, analyzed and identified the structure of its main compounds, and established a method for simultaneous determination of its content by refe-rence substance. A total of 34 major compounds in IJ, including 14 reference compounds, were identified or predicted online. Moreover, an UPLC-UV content determination method was developed for 11 compounds [danshensu, caffeic acid, vicenin-2,(1S,2S)-globoidnan B, rutin,(+)-rabdosiin,(-)-rabdosiin,(1S,2S)-rabdosiin, shimobashiric acid C, rosmarinic acid, and pedalitin]. The method exhibited excellent separation, stability, and repeatability, with a wide linear range(0.10-520.00 µg·mL~(-1)) and high linearity(R~2>0.999). The average recovery rates ranged from 94.72% to 104.2%. The principal component analysis(PCA) demonstrated a clear difference between the roots and stems and leaves of IJ, indicating good separation by cluster. Furthermore, the orthogonal partial least squares discriminant analysis(OPLS-DA) model was employed, and six main differentially identified compounds were identified: rosmarinic acid, shimobashiric acid C, epinodosin, pedalitin, rutin, and(1S,2S)-rabdosiin. In summary, this study established a strategy and method for distinguishing different parts of IJ, providing a valuable tool for quality control of IJ and a basis for the ratio-nal utilization and sustainable development of IJ.


Assuntos
Quimiometria , Medicamentos de Ervas Chinesas , Isodon , Espectrometria de Massas , Folhas de Planta , Cromatografia Líquida de Alta Pressão/métodos , Isodon/química , Espectrometria de Massas/métodos , Quimiometria/métodos , Folhas de Planta/química , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/análise , Raízes de Plantas/química , Caules de Planta/química
20.
BMC Genomics ; 24(1): 264, 2023 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-37198531

RESUMO

Long non-coding RNAs (lncRNAs) play a crucial role in numbers of biological processes and have received wide attention during the past years. Since the rapid development of high-throughput transcriptome sequencing technologies (RNA-seq) lead to a large amount of RNA data, it is urgent to develop a fast and accurate coding potential predictor. Many computational methods have been proposed to address this issue, they usually exploit information on open reading frame (ORF), protein sequence, k-mer, evolutionary signatures, or homology. Despite the effectiveness of these approaches, there is still much room to improve. Indeed, none of these methods exploit the contextual information of RNA sequence, for example, k-mer features that counts the occurrence frequencies of continuous nucleotides (k-mer) in the whole RNA sequence cannot reflect local contextual information of each k-mer. In view of this shortcoming, here, we present a novel alignment-free method, CPPVec, which exploits the contextual information of RNA sequence for coding potential prediction for the first time, it can be easily implemented by distributed representation (e.g., doc2vec) of protein sequence translated from the longest ORF. The experimental findings demonstrate that CPPVec is an accurate coding potential predictor and significantly outperforms existing state-of-the-art methods.


Assuntos
RNA Longo não Codificante , Sequência de Aminoácidos , RNA Longo não Codificante/genética , Sequência de Bases , Análise de Sequência de RNA
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