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1.
Proc Natl Acad Sci U S A ; 120(24): e2302854120, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-37276396

RESUMO

Stomata are pores found in the epidermis of stems or leaves that modulate both plant gas exchange and water/nutrient uptake. The development and function of plant stomata are regulated by a diverse range of environmental cues. However, how carbohydrate status in preexisting leaves might determine systemic stomatal formation within newly developing leaves has remained obscure. The glucose (Glc) sensor HEXOKINASE1 (HXK1) has been reported to decrease the stability of an ethylene/Glc signaling transcriptional regulator, EIN3 (ETHYLENE INSENSITIVE3). EIN3 in turn directly represses the expression of SUC2 (sucrose transporter 2), encoding a master transporter of sucrose (Suc). Further, KIN10, a nuclear regulator involved in energy homeostasis, has been reported to repress the transcription factor SPCH (SPEECHLESS), a master regulator of stomatal development. Here, we demonstrate that the Glc status of preexisting leaves determines systemic stomatal development within newly developing leaves by the HXK1-¦EIN3-¦SUC2 module. Further, increasing Glc levels in preexisting leaves results in a HXK1-dependent decrease of EIN3 and increase of SUC2, triggering the perception, amplification and relay of HXK1-dependent Glc signaling and thereby triggering Suc transport from mature to newly developing leaves. The HXK1-¦EIN3-¦SUC2 molecular module thereby drives systemic Suc transport from preexisting leaves to newly developing leaves. Subsequently, increasing Suc levels within newly developing leaves promotes stomatal formation through the established KIN10⟶ SPCH module. Our findings thus show how a carbohydrate signal in preexisting leaves is sensed, amplified and relayed to determine the extent of systemic stomatal development within newly developing leaves.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Açúcares/metabolismo , Folhas de Planta/metabolismo , Etilenos/metabolismo , Sacarose/metabolismo , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo
2.
Proc Natl Acad Sci U S A ; 120(22): e2219216120, 2023 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-37216514

RESUMO

The assembly of the ß-amyloid peptide (Aß) to form oligomers and fibrils is closely associated with the pathogenesis and progression of Alzheimer's disease. Aß is a shape-shifting peptide capable of adopting many conformations and folds within the multitude of oligomers and fibrils the peptide forms. These properties have precluded detailed structural elucidation and biological characterization of homogeneous, well-defined Aß oligomers. In this paper, we compare the structural, biophysical, and biological characteristics of two different covalently stabilized isomorphic trimers derived from the central and C-terminal regions Aß. X-ray crystallography reveals the structures of the trimers and shows that each trimer forms a ball-shaped dodecamer. Solution-phase and cell-based studies demonstrate that the two trimers exhibit markedly different assembly and biological properties. One trimer forms small soluble oligomers that enter cells through endocytosis and activate capase-3/7-mediated apoptosis, while the other trimer forms large insoluble aggregates that accumulate on the outer plasma membrane and elicit cellular toxicity through an apoptosis-independent mechanism. The two trimers also exhibit different effects on the aggregation, toxicity, and cellular interaction of full-length Aß, with one trimer showing a greater propensity to interact with Aß than the other. The studies described in this paper indicate that the two trimers share structural, biophysical, and biological characteristics with oligomers of full-length Aß. The varying structural, assembly, and biological characteristics of the two trimers provide a working model for how different Aß trimers can assemble and lead to different biological effects, which may help shed light on the differences among Aß oligomers.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Humanos , Peptídeos beta-Amiloides/metabolismo , Conformação Proteica , Cristalografia por Raios X , Membrana Celular/metabolismo , Fragmentos de Peptídeos/química
3.
Plant Physiol ; 195(3): 2309-2322, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38466216

RESUMO

Soil (or plant) water deficit accelerates plant reproduction. However, the underpinning molecular mechanisms remain unknown. By modulating cell division/number, ABSCISIC ACID-INSENSITIVE 5 (ABI5), a key bZIP (basic (region) leucine zippers) transcription factor, regulates both seed development and abiotic stress responses. The KIP-RELATED PROTEIN (KRP) cyclin-dependent kinases (CDKs) play an essential role in controlling cell division, and SHOOT MERISTEMLESS (STM) plays a key role in the specification of flower meristem identity. Here, our findings show that abscisic acid (ABA) signaling and/or metabolism in adjust reproductive outputs (such as rosette leaf number and open flower number) under water-deficient conditions in Arabidopsis (Arabidopsis thaliana) plants. Reproductive outputs increased under water-sufficient conditions but decreased under water-deficient conditions in the ABA signaling/metabolism mutants abscisic acid2-1 (aba2-1), aba2-11, abscisic acid insensitive3-1 (abi3-1), abi4-1, abi5-7, and abi5-8. Further, under water-deficient conditions, ABA induced-ABI5 directly bound to the promoter of KRP1, which encodes a CDK that plays an essential role in controlling cell division, and this binding subsequently activated KRP1 expression. In turn, KRP1 physically interacted with STM, which functions in the specification of flower meristem identity, promoting STM degradation. We further demonstrate that reproductive outputs are adjusted by the ABI5-KRP1-STM molecular module under water-deficient conditions. Together, our findings reveal the molecular mechanism by which ABA signaling and/or metabolism regulate reproductive development under water-deficient conditions. These findings provide insights that may help guide crop yield improvement under water deficiency.


Assuntos
Ácido Abscísico , Proteínas de Arabidopsis , Arabidopsis , Flores , Regulação da Expressão Gênica de Plantas , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Ácido Abscísico/metabolismo , Flores/genética , Flores/crescimento & desenvolvimento , Flores/fisiologia , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/genética , Transdução de Sinais , Meristema/genética , Meristema/crescimento & desenvolvimento , Meristema/metabolismo , Reprodução , Mutação/genética , Quinases Ciclina-Dependentes/metabolismo , Quinases Ciclina-Dependentes/genética , Proteínas de Homeodomínio
4.
Hum Mol Genet ; 31(18): 3144-3160, 2022 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-35567413

RESUMO

Myotonic dystrophy (DM) is caused by expansions of C(C)TG repeats in the non-coding regions of the DMPK and CNBP genes, and DM patients often suffer from sudden cardiac death due to lethal conduction block or arrhythmia. Specific molecular changes that underlie DM cardiac pathology have been linked to repeat-associated depletion of Muscleblind-like (MBNL) 1 and 2 proteins and upregulation of CUGBP, Elav-like family member 1 (CELF1). Hypothesis solely targeting MBNL1 or CELF1 pathways that could address all the consequences of repeat expansion in heart remained inconclusive, particularly when the direct cause of mortality and results of transcriptome analyses remained undetermined in Mbnl compound knockout (KO) mice with cardiac phenotypes. Here, we develop Myh6-Cre double KO (DKO) (Mbnl1-/-; Mbnl2cond/cond; Myh6-Cre+/-) mice to eliminate Mbnl1/2 in cardiomyocytes and observe spontaneous lethal cardiac events under no anesthesia. RNA sequencing recapitulates DM heart spliceopathy and shows gene expression changes that were previously undescribed in DM heart studies. Notably, immunoblotting reveals a nearly 6-fold increase of Calsequestrin 1 and 50% reduction of epidermal growth factor proteins. Our findings demonstrate that complete ablation of MBNL1/2 in cardiomyocytes is essential for generating sudden death due to lethal cardiac rhythms and reveal potential mechanisms for DM heart pathogenesis.


Assuntos
Distrofia Miotônica , Processamento Alternativo/genética , Animais , Calsequestrina/genética , Proteínas de Ligação a DNA/genética , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/patologia , Família de Proteínas EGF/genética , Família de Proteínas EGF/metabolismo , Camundongos , Camundongos Knockout , Músculo Esquelético/metabolismo , Miócitos Cardíacos/metabolismo , Distrofia Miotônica/patologia , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
5.
Clin Immunol ; 263: 110205, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38575044

RESUMO

Increasing clinical data show that the imbalance of host metallome is closely associated with different kinds of disease, however, the intrinsic mechanisms of action of metals in immunity and pathogenesis of disease remain largely undefined. There is lack of multiplexed profiling system to integrate the metalloproteome-immunoproteome information at systemic level for exploring the roles of metals in immunity and disease pathogenesis. In this study, we build up a metal-coding assisted multiplexed proteome assay platform for serum metalloproteomic and immunoproteomic profiling. By taking COVID-19 as a showcase, we unbiasedly uncovered the most evident modulation of iron-related proteins, i.e., Ft and Tf, in serum of severe COVID-19 patients, and the value of Ft/Tf could work as a robust biomarker for COVID-19 severity stratification, which overtakes the well-established clinical risk factors (cytokines). We further uncovered a tight association of transferrin with inflammation mediator IL-10 in COVID-19 patients, which was proved to be mainly governed by the monocyte/macrophage of liver, shedding light on new pathophysiological and immune regulatory mechanisms of COVID-19 disease. We finally validated the beneficial effects of iron chelators as anti-viral agents in SARS-CoV-2-infected K18-hACE2 mice through modulation of iron dyshomeostasis and alleviating inflammation response. Our findings highlight the critical role of liver-mediated iron dysregulation in COVID-19 disease severity, providing solid evidence on the involvement of iron-related proteins in COVID-19 pathophysiology and immunity.


Assuntos
COVID-19 , Ferro , Proteoma , SARS-CoV-2 , COVID-19/imunologia , Humanos , Animais , SARS-CoV-2/imunologia , Camundongos , Ferro/metabolismo , Proteômica/métodos , Transferrina/metabolismo , Metaloproteínas/imunologia , Metaloproteínas/metabolismo , Masculino , Feminino , Biomarcadores/sangue , Biomarcadores/metabolismo , Quelantes de Ferro/uso terapêutico , Quelantes de Ferro/farmacologia , Interleucina-10/imunologia , Interleucina-10/metabolismo , Pessoa de Meia-Idade
6.
J Virol ; 97(9): e0094823, 2023 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-37671867

RESUMO

Proteolytic processing of human immunodeficiency virus type 1 particles mediated by viral protease (PR) is essential for acquiring virus infectivity. Activation of PR embedded in Gag-Pol is triggered by Gag-Pol dimerization during virus assembly. We previously reported that amino acid substitutions at the RT tryptophan repeat motif destabilize virus-associated RT and attenuate the ability of efavirenz (EFV, an RT dimerization enhancer) to increase PR-mediated Gag cleavage efficiency. Furthermore, a single amino acid change at RT significantly reduces virus yields due to enhanced Gag cleavage. These data raise the possibility of the RT domain contributing to PR activation by promoting Gag-Pol dimerization. To test this hypothesis, we investigated the putative involvement of a hydrophobic leucine repeat motif (LRM) spanning RT L282 to L310 in RT/RT interactions. We found that LRM amino acid substitutions led to RT instability and that RT is consequently susceptible to degradation by PR. The LRM mutants exhibited reduced Gag cleavage efficiencies while attenuating the EFV enhancement of Gag cleavage. In addition, an RT dimerization-defective mutant, W401A, reduced enhanced Gag cleavage via a leucine zipper (LZ) motif inserted at the deleted Gag-Pol region. Importantly, the presence of RT and integrase domains failed to counteract the LZ enhancement of Gag cleavage. A combination of the Gag cleavage enhancement factors EFV and W402A markedly impaired Gag cleavage, indicating a disruption of W402A Gag-Pol dimerization following EFV binding to W402A Gag-Pol. Our results support the idea that RT modulates PR activation by affecting Gag-Pol/Gag-Pol interaction. IMPORTANCE A stable reverse transcriptase (RT) p66/51 heterodimer is required for HIV-1 genome replication in host cells following virus entry. The activation of viral protease (PR) to mediate virus particle processing helps viruses acquire infectivity following cell release. RT and PR both appear to be major targets for inhibiting HIV-1 replication. We found a strong correlation between impaired p66/51RT stability and deficient PR-mediated Gag cleavage, suggesting that RT/RT interaction is critical for triggering PR activation via the promotion of adequate Gag-Pol dimerization. Accordingly, RT/RT interaction is a potentially advantageous method for anti-HIV/AIDS therapy if it is found to simultaneously block PR and RT enzymatic activity.


Assuntos
Protease de HIV , Transcriptase Reversa do HIV , HIV-1 , Proteólise , Produtos do Gene gag do Vírus da Imunodeficiência Humana , Humanos , Protease de HIV/genética , Protease de HIV/metabolismo , Transcriptase Reversa do HIV/metabolismo , Produtos do Gene gag do Vírus da Imunodeficiência Humana/metabolismo , HIV-1/enzimologia , HIV-1/metabolismo , Estabilidade Enzimática , Zíper de Leucina , Multimerização Proteica , Internalização do Vírus , Replicação Viral , Ativação Enzimática , Produtos do Gene pol do Vírus da Imunodeficiência Humana/metabolismo
7.
Plant Physiol ; 194(1): 391-407, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-37738410

RESUMO

Exposure of dark-grown etiolated seedlings to light triggers the transition from skotomorphogenesis/etiolation to photomorphogenesis/de-etiolation. In the life cycle of plants, de-etiolation is essential for seedling development and plant survival. The mobilization of soluble sugars (glucose [Glc], sucrose, and fructose) derived from stored carbohydrates and lipids to target organs, including cotyledons, hypocotyls, and radicles, underpins de-etiolation. Therefore, dynamic carbohydrate biochemistry is a key feature of this phase transition. However, the molecular mechanisms coordinating carbohydrate status with the cellular machinery orchestrating de-etiolation remain largely opaque. Here, we show that the Glc sensor HEXOKINASE 1 (HXK1) interacts with GROWTH REGULATOR FACTOR5 (GRF5), a transcriptional activator and key plant growth regulator, in Arabidopsis (Arabidopsis thaliana). Subsequently, GRF5 directly binds to the promoter of phytochrome A (phyA), encoding a far-red light (FR) sensor/cotyledon greening inhibitor. We demonstrate that the status of Glc within dark-grown etiolated cotyledons determines the de-etiolation of seedlings when exposed to light irradiation by the HXK1-GRF5-phyA molecular module. Thus, following seed germination, accumulating Glc within dark-grown etiolated cotyledons stimulates a HXK1-dependent increase of GRF5 and an associated decrease of phyA, triggering the perception, amplification, and relay of HXK1-dependent Glc signaling, thereby facilitating the de-etiolation of seedlings following light irradiation. Our findings, therefore, establish how cotyledon carbohydrate signaling under subterranean darkness is sensed, amplified, and relayed, determining the phase transition from skotomorphogenesis to photomorphogenesis on exposure to light irradiation.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Plântula/metabolismo , Cotilédone/metabolismo , Estiolamento , Glucose/metabolismo , Luz , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Fitocromo A/metabolismo , Regulação da Expressão Gênica de Plantas
8.
Opt Express ; 32(7): 12438-12448, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38571066

RESUMO

Ultraviolet B light-emitting diodes (UVB LEDs) hold promise in medical and agricultural applications. The commonly used sapphire substrate for their epitaxy growth possesses a high refractive index and excellent UV light absorption characteristics. However, this high refractive index can induce total internal reflection (TIR) within the substrate, leading to decreased Light Extraction Efficiency (LEE) due to light absorption within the material. In this study, UVB LED chips were detached from the sub-mount substrate and directly affixed onto an aluminum nitride (AlN) substrate with superior heat dissipation using a eutectic process. This was undertaken to diminish packaged thermal resistance (PTR). Simultaneously, optimization of the UVB LED packaging structure was employed to alleviate LEE losses caused by the TIR phenomenon, with the overarching goal of enhancin external quantum efficiency (EQE). The final experimental findings suggest that optimal LEE is achieved with packaging dimensions, including a length (ELL) of 2 mm, a width (ELW) of 1.62 mm, and a height (ELH) of 0.52 mm. At an input current of 200 mA, the output power reaches 50 mW, resulting in an EQE of 6.3%. Furthermore, the packaged thermal resistance from the chip to the substrate surface can be reduced to 4.615 K/W.

9.
Brain Cogn ; 174: 106120, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38142535

RESUMO

Previous studies found that prolonged musical training can promote language processing, but few studies have examined whether and how musical training affects the processing of accentuation in spoken language. In this study, a vocabulary detection task was conducted, with Chinese single sentences as materials, to investigate how musicians and non-musicians process corrective accent and information accent in the sentence-middle and sentence-final positions. In the sentence-middle position, results of the cluster-based permutation t-tests showed significant differences in the 574-714 ms time window for the control group. In the sentence-final position, the cluster-based permutation t-tests revealed significant differences in the 612-810 ms time window for the music group and in the 616-812 ms time window for the control group. These significant positive effects were induced by the processing of information accent relative to that of corrective accent. These results suggest that both groups were able to distinguish corrective accent from information accent, but they processed the two accent types differently in the sentence-middle position. These findings show that musical training has a cross-domain effect on spoken language processing and that the accent position also affects its processing.


Assuntos
Música , Percepção da Fala , Humanos , Idioma , Potenciais Evocados , Vocabulário
10.
Ren Fail ; 46(2): 2365394, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38874108

RESUMO

BACKGROUND: The survival of critically ill patients with acute kidney injury (AKI) undergoing continuous renal replacement therapy (CRRT) is highly dependent on their nutritional status. OBJECTIVES: The prognostic nutritional index (PNI) is an indicator used to assess nutritional status and is calculated as: PNI = (serum albumin in g/dL) × 10 + (total lymphocyte count in/mm3) × 0.005. In this retrospective study, we investigated the correlation between this index and clinical outcomes in critically ill patients with AKI receiving CRRT. METHODS: We analyzed data from 2076 critically ill patients admitted to the intensive care unit at Changhua Christian Hospital, a tertiary hospital in central Taiwan, between January 1, 2010, and April 30, 2021. All these patients met the inclusion criteria of the study. The relationship between PNI and renal replacement therapy-free survival (RRTFS) and mortality was examined using logistic regression models, Cox proportional hazard models, and propensity score matching. High utilization rate of parenteral nutrition (PN) was observed in our study. Subgroup analysis was performed to explore the interaction effect between PNI and PN on mortality. RESULTS: Patients with higher PNI levels exhibited a greater likelihood of achieving RRTFS, with an adjusted odds ratio of 2.43 (95% confidence interval [CI]: 1.98-2.97, p-value < 0.001). Additionally, these patients demonstrated higher survival rates, with an adjusted hazard ratio of 0.84 (95% CI: 0.72-0.98) for 28-day mortality and 0.80 (95% CI: 0.69-0.92) for 90-day mortality (all p-values < 0.05), compared to those in the low PNI group. While a high utilization rate of parenteral nutrition (PN) was observed, with 78.86% of CRRT patients receiving PN, subgroup analysis showed that high PNI had an independent protective effect on mortality outcomes in AKI patients receiving CRRT, regardless of their PN status. CONCLUSIONS: PNI can serve as an easy, simple, and efficient measure of lymphocytes and albumin levels to predict RRTFS and mortality in AKI patients with require CRRT.


Assuntos
Injúria Renal Aguda , Terapia de Substituição Renal Contínua , Estado Terminal , Avaliação Nutricional , Estado Nutricional , Humanos , Masculino , Feminino , Estudos Retrospectivos , Pessoa de Meia-Idade , Idoso , Injúria Renal Aguda/terapia , Injúria Renal Aguda/mortalidade , Taiwan/epidemiologia , Prognóstico , Estado Terminal/mortalidade , Estado Terminal/terapia , Unidades de Terapia Intensiva/estatística & dados numéricos , Nutrição Parenteral/estatística & dados numéricos
11.
Microsurgery ; 44(4): e31186, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38716649

RESUMO

INTRODUCTION: Free flap transfer for head and neck defects has gained worldwide acceptance. Because flap failure is a devastating outcome, studies have attempted to identify risk factors-including renal failure. We sought to determine whether end-stage renal disease (ESRD) patients undergoing dialysis are at increased risk of flap failure following microsurgical head and neck reconstruction. PATIENTS AND METHODS: The study's participants were patients who underwent free flap reconstruction in the head and neck region at Hualien Tzu Chi Hospital between January 2010 and December 2019. We used the National Health Insurance "Specific Diagnosis and Treatment Code" to identify patients undergoing dialysis; these patients comprised the dialysis group, whose members were matched to a non-dialysis group for age and gender. The dependent variables were flap survival rate, take-back rate, and flap failure risk between the dialysis and non-dialysis groups. RESULTS: We included 154 patients in the dialysis (n = 14) and non-dialysis (n = 140) groups. The groups were similar in terms of age and most comorbidities, except diabetes mellitus, hypertension, and coronary artery disease, which were more prevalent in the dialysis group. The dialysis and non-dialysis groups had similar flap survival rates (100% vs. 92.9%; p = .600). Twenty-three patients underwent take-back surgery, most in the non-dialysis group (14.3% vs. 15.0%; p = 1.000). Patients in the dialysis group were more likely to have prolonged intensive care unit stays; however, dialysis alone did not predict flap failure (OR: 0.83; p = .864). CONCLUSION: This study found no significant differences in free flap survival and take-back rates between patients with and without dialysis. Dialysis did not increase the risk of flap failure following microsurgical head and neck reconstruction in this study; however, prospective, randomized controlled trials are needed.


Assuntos
Retalhos de Tecido Biológico , Neoplasias de Cabeça e Pescoço , Falência Renal Crônica , Microcirurgia , Procedimentos de Cirurgia Plástica , Diálise Renal , Humanos , Masculino , Feminino , Falência Renal Crônica/terapia , Falência Renal Crônica/complicações , Pessoa de Meia-Idade , Retalhos de Tecido Biológico/transplante , Procedimentos de Cirurgia Plástica/métodos , Microcirurgia/métodos , Neoplasias de Cabeça e Pescoço/cirurgia , Neoplasias de Cabeça e Pescoço/complicações , Idoso , Estudos Retrospectivos , Sobrevivência de Enxerto , Fatores de Risco , Adulto
12.
J Physiol ; 601(22): 5011-5031, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35318675

RESUMO

Extended periods of bed rest and limb immobilization are required for healing post-injury or disease, yet disuse can result in significant muscle atrophy and decreased quality of life in older adults. Physical rehabilitation is commonly prescribed to recover these deficits, yet accumulation of reactive oxygen species and sustained rates of protein degradation persist during the rehabilitation period that can significantly delay or prevent recovery. Pericytes, considered the primary mesenchymal and vascular stromal cell in skeletal muscle, secrete beneficial factors that maintain baseline muscle mass, yet minimal information exists regarding the pericyte response to disuse and recovery. In the current study, single-cell RNA sequencing and functional assays were performed to demonstrate that pericytes in mouse skeletal muscle lose the capacity to synthesize antioxidants during disuse and recovery. This information was used to guide the design of a strategy in which healthy donor pericytes were stimulated with hydrogen peroxide (H2 O2 ) to produce small extracellular vesicles (sEVs) that effectively restored myofibre size in adult and aged muscle after disuse. Proteomic assessment detected 11 differentially regulated proteins in primed sEVs that may account for recovery of muscle, including proteins associated with extracellular matrix composition and anti-inflammatory and antioxidant processes. This study demonstrates that healthy H2 O2 -primed pericyte-derived sEVs effectively improve skeletal muscle recovery after immobilization, presenting a novel acellular approach to rebuild muscle mass in older adults after a period of disuse. KEY POINTS: Previous studies suggest that prolonged oxidative stress is a barrier to skeletal muscle recovery after a period of immobilization. In this study we demonstrate that muscle-resident perivascular stromal cells (pericytes) become dysfunctional and lack the capacity to mount an antioxidant defence after disuse in mice. Hydrogen peroxide treatment of healthy pericytes in vitro simulates the release of small extracellular vesicles (sEVs) that effectively recover skeletal muscle fibre size and extracellular matrix remodelling in young adult and aged mice after disuse. Pericyte-derived sEVs present a novel acellular strategy to recover skeletal muscle after disuse.


Assuntos
Peróxido de Hidrogênio , Qualidade de Vida , Camundongos , Animais , Peróxido de Hidrogênio/metabolismo , Antioxidantes/metabolismo , Proteômica , Músculo Esquelético/fisiologia , Atrofia Muscular/metabolismo
13.
J Biol Chem ; 298(12): 102634, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36273584

RESUMO

Myosin B (MyoB) is a class 14 myosin expressed in all invasive stages of the malaria parasite, Plasmodium falciparum. It is not associated with the glideosome complex that drives motility and invasion of host cells. During red blood cell invasion, MyoB remains at the apical tip of the merozoite but is no longer observed once invasion is completed. MyoB is not essential for parasite survival, but when it is knocked out, merozoites are delayed in the initial stages of red blood cell invasion, giving rise to a growth defect that correlates with reduced invasion success. Therefore, further characterization is needed to understand how MyoB contributes to parasite invasion. Here, we have expressed and purified functional MyoB with the help of parasite-specific chaperones Hsp90 and Unc45, characterized its binding to actin and its known light chain MLC-B using biochemical and biophysical methods and determined its low-resolution structure in solution using small angle X-ray scattering. In addition to MLC-B, we found that four other putative regulatory light chains bind to the MyoB IQ2 motif in vitro. The purified recombinant MyoB adopted the overall shape of a myosin, exhibited actin-activated ATPase activity, and moved actin filaments in vitro. Additionally, we determined that the ADP release rate was faster than the ATP turnover number, and thus, does not appear to be rate limiting. This, together with the observed high affinity to actin and the specific localization of MyoB, may point toward a role in tethering and/or force sensing during early stages of invasion.


Assuntos
Miosina não Muscular Tipo IIB , Plasmodium falciparum , Proteínas de Protozoários , Actinas/metabolismo , Calmodulina/genética , Calmodulina/metabolismo , Miosinas/metabolismo , Miosina não Muscular Tipo IIB/metabolismo , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo
14.
Emerg Infect Dis ; 29(9): 1780-1788, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37610104

RESUMO

Anaplasma capra is an emerging tickborne human pathogen initially recognized in China in 2015; it has been reported in ticks and in a wide range of domestic and wild animals worldwide. We describe whole-genome sequences of 2 A. capra strains from metagenomic sequencing of purified erythrocytes from infected goats in China. The genome of A. capra was the smallest among members of the genus Anaplasma. The genomes of the 2 A. capra strains contained comparable G+C content and numbers of pseudogenes with intraerythrocytic Anaplasma species. The 2 A. capra strains had 54 unique genes. The prevalence of A. capra was high among goats in the 2 endemic areas. Phylogenetic analyses revealed that the A. capra strains detected in this study were basically classified into 2 subclusters with those previously detected in Asia. Our findings clarify details of the genomic characteristics of A. capra and shed light on its genetic diversity.


Assuntos
Genômica , Cabras , Animais , Humanos , Prevalência , Filogenia , Anaplasma/genética , China/epidemiologia
15.
Neuropathol Appl Neurobiol ; 49(2): e12890, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36765387

RESUMO

AIMS: Muscleblind-like 2 (MBNL2) plays a crucial role in regulating alternative splicing during development and mouse loss of MBNL2 recapitulates brain phenotypes in myotonic dystrophy (DM). However, the mechanisms underlying DM neuropathogenesis during brain development remain unclear. In this study, we aim to investigate the impact of MBNL2 elimination on neuronal development by Mbnl2 conditional knockout (CKO) mouse models. METHODS: To create Mbnl2 knockout neurons, cDNA encoding Cre-recombinase was delivered into neural progenitors of Mbnl2flox/flox mouse brains by in utero electroporation. The morphologies and dynamics of dendritic spines were monitored by confocal and two-photon microscopy in brain slices and live animals from the neonatal period into adulthood. To investigate the underlying molecular mechanism, we further detected the changes in the splicing and molecular interactions of proteins associated with spinogenesis. RESULTS: We found that Mbnl2 knockout in cortical neurons decreased dendritic spine density and dynamics in adolescent mice. Mbnl2 ablation caused the adducin 1 (ADD1) isoform to switch from adult to fetal with a frameshift, and the truncated ADD1 failed to interact with alpha-II spectrin (SPTAN1), a critical protein for spinogenesis. In addition, expression of ADD1 adult isoform compensated for the reduced dendritic spine density in cortical neurons deprived of MBNL2. CONCLUSION: MBNL2 plays a critical role in maintaining the dynamics and homeostasis of dendritic spines in the developing brain. Mis-splicing of downstream ADD1 may account for the alterations and contribute to the DM brain pathogenesis.


Assuntos
Espinhas Dendríticas , Distrofia Miotônica , Animais , Camundongos , Encéfalo/patologia , Espinhas Dendríticas/metabolismo , Espinhas Dendríticas/patologia , Distrofia Miotônica/genética , Isoformas de Proteínas/metabolismo
16.
Inorg Chem ; 62(4): 1570-1579, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36656719

RESUMO

A new copper indium selenide, Ba3.5Cu7.55In1.15Se9, was synthesized by the KBr flux reaction at 800 °C. The compound crystallizes with orthorhombic Pnma, a = 46.1700(12) Å, b = 4.26710(10) Å, c = 19.8125(5) Å, and Z = 8. The structural framework mainly consists of four sites of cubane-type defective M4Se3 (M = Cu, Cu/In) units with disordered Cu+/In3+ ions present at the part corner of each unit. The single crystal emits intense photoluminescence at 657 nm with a relative quantum yield (RQY) 0.2 times that of rhodamine 6G powder. The compound belongs to a direct band gap at 1.91 eV, analyzed by Tauc's plot, and the energy is close to the PL position. The Hall effect measurement on a pressed pellet reveals an n-type conductivity with a carrier concentration of 3.358 × 1017 cm-3 and a mobility of 24.331 cm2 V-1 s-1. Furthermore, the compound produces a strong nonlinear third-harmonic generation (THG), with an χS(3) value of 1.3 × 105 pm2/V2 comparable to 1.6 × 105 pm2/V2 for AgGaSe2 measured at 800 nm.

17.
BMC Gastroenterol ; 23(1): 440, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38097952

RESUMO

BACKGROUND: Type 1 gastric neuroendocrine tumors (NETs) are relatively rare to the extent that some physicians have little experience in diagnosing and treating them. The purpose of this study was to increase the understanding of the disease by analyzing and summarizing the management and prognoses of patients with type 1 gastric NETs at our center. METHODS: The data of 229 patients (59.4% female) with type 1 gastric NETs who were treated at our center during 2011-2022 were retrospectively analyzed. RESULTS: The average patient age was 50.5 ± 10.8 years. Multiple tumors affected 72.5% of the patients; 66.4% of the tumors were < 1 cm, 69.4% were NET G1, and 2.2% were stage III-IV. A total of 76.9% of the patients had received endoscopic management, 60.7% had received traditional Chinese medicine treatment, 10.5% received somatostatin analogues treatment, and 6.6% underwent surgical resection. Seventy patients (41.2%) experienced the first recurrence after a median follow-up of 31 months (range: 2-122 months), and the median recurrence-free time was 43 months. The 1-, 2-, and 3-year cumulative recurrence-free survival rates were 71.8%, 56.8%, and 50.3%, respectively. During a median follow-up of 39 months (range: 2-132 months), one patient had bilateral pulmonary metastasis, and no disease-related deaths were observed. CONCLUSION: Type 1 gastric NETs have a high recurrence rate and a long disease course, underscoring the importance of long-term and comprehensive management.


Assuntos
Tumores Neuroendócrinos , Neoplasias Gástricas , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Masculino , Tumores Neuroendócrinos/diagnóstico , Tumores Neuroendócrinos/terapia , Tumores Neuroendócrinos/patologia , Estudos Retrospectivos , Prognóstico , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/terapia
18.
J Immunol ; 207(11): 2868-2877, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34686582

RESUMO

The IL-36 cytokines are known to play various roles in mediating the immune response to infection in a tissue- and pathogen-dependent manner. The present study seeks to investigate the role of IL-36R signaling in C57BL/6 mouse corneas in response to Pseudomonas aeruginosa infection. IL-36α-/-, IL-36γ-/-, and IL-36R-/- mice had significantly more severe keratitis than wild-type mice. At six hours postinfection, IL-36α pretreatment augmented P. aeruginosa-induced expression of IL-1Ra, IL-36γ, LCN2, and S100A8/A9. At one day postinfection, exogenous IL-36α suppressed, whereas IL-36α deficiency promoted, the expression of IL-1ß. At three days postinfection, exogenous IL-36α suppressed Th1 but promoted Th2 immune response. IL-36α stimulated the infiltration of IL-22-expressing immune cells, and IL-22 neutralization resulted in more severe keratitis. IL-36α alone stimulated dendritic cell infiltration in B6 mouse corneas. Taken together, our study suggests that IL-36R signaling plays a protective role in the pathogenesis of P. aeruginosa keratitis by promoting the innate immune defense, Th2, and/or Th22/IL-22 immune responses. Exogenous IL-36α might be a potential therapy for improving the outcome of P. aeruginosa keratitis.


Assuntos
Córnea/imunologia , Interleucina-1/imunologia , Infecções por Pseudomonas/imunologia , Pseudomonas aeruginosa/imunologia , Animais , Interleucina-1/deficiência , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
19.
Cardiology ; 148(2): 138-149, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36596284

RESUMO

INTRODUCTION: Data on first-line ablation treatment for patients with symptomatic atrial fibrillation (AF) are scarce. This study indirectly compared the efficacy and safety of cryoballoon ablation (CBA) versus radiofrequency ablation (RFA) as initial therapy for symptomatic AF. METHODS: We searched the EMBASE, PubMed, Cochrane Library, and ClinicalTrials.gov databases for randomized controlled trials (RCTs) that compared CBA or RFA with antiarrhythmic drugs (AADs) as first-line treatment for AF from the time of database establishment up to December 2021. The odds ratio (OR) with a 95% confidence interval (CI) was used as a measure of the treatment effect. RESULTS: Six RCTs (3 CBA, 3 RFA) that enrolled a total of 1,215 patients were included in this analysis. There were no significant differences in atrial arrhythmia (AA) (OR 0.993, 95% CI: 0.602-1.638), symptomatic AA (OR 0.638, 95% CI: 0.344-1.182), or serious adverse events (OR 1.474, 95% CI: 0.404-5.376) between the two ablation techniques. The incidences of additional CBA therapy (OR 2.693, 95% CI: 1.277-5.681) and patients who crossed over to AAD therapy (OR 0.345, 95% CI: 0.179-0.664) in the CBA group were significantly lower than those in the RFA group. CONCLUSION: Among patients with paroxysmal AF receiving initial therapy, CBA and RFA share a similar efficacy and safety profile. When pulmonary vein isolation is performed by CBA, study crossover and the need for additional ablation are substantially lower.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Criocirurgia , Ablação por Radiofrequência , Humanos , Criocirurgia/métodos , Resultado do Tratamento , Metanálise em Rede , Ablação por Cateter/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Recidiva
20.
J Appl Microbiol ; 134(2)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36639131

RESUMO

AIMS: Feathers are keratin-rich byproducts of poultry processing, but those are often frequently abandoned as garbage and thus polluting the environment. Therefore, the study focused on the efficient biodegradation, bioactivity, and high-value application of feather keratin. METHODS AND RESULTS: Feather-degrading bacteria were identified, and the degradation properties were characterized. DPPH (1,1-Diphenyl-2-picrylhydrazyl radical) and ABTS (2,2'-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid))radical scavenging assays, cytotoxicity assays, intracellular reactive oxygen scavenging assays, and cell migration assays were used to examine the biological activities of the feather keratin hydrolysis peptides (FKHPs). The results showed that we screened a feather-degrading strain of Bacillus licheniformis 8-4, which achieved complete degradation of 2% (w/v) feathers within 48 h. Notably, the feather fermentation broth was particularly high in FKHPs, which exhibited good DPPH and ABTS radical scavenging ability. Further studies revealed that FKHPs had both the ability to scavenge H2O2-induced ROS from HaCat cells and the ability to promote HaCat cell migration, while remaining non-toxic. CONCLUSIONS: The effective feather-degrading ability of B. licheniformis 8-4 allowed for the fermentation of feather medium to yield active peptides that were both antioxidants and cell-migration enhancers.


Assuntos
Bacillus licheniformis , Animais , Antioxidantes/química , Plumas/química , Plumas/metabolismo , Plumas/microbiologia , Queratinas/metabolismo , Peróxido de Hidrogênio/metabolismo , Galinhas , Peptídeos/farmacologia , Peptídeos/química , Peptídeo Hidrolases/metabolismo
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