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1.
Nature ; 612(7938): 92-99, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36261525

RESUMO

The Indo-Pacific Warm Pool (IPWP) exerts a dominant role in global climate by releasing huge amounts of water vapour and latent heat to the atmosphere and modulating upper ocean heat content (OHC), which has been implicated in modern climate change1. The long-term variations of IPWP OHC and their effect on monsoonal hydroclimate are, however, not fully explored. Here, by combining geochemical proxies and transient climate simulations, we show that changes of IPWP upper (0-200 m) OHC over the past 360,000 years exhibit dominant precession and weaker obliquity cycles and follow changes in meridional insolation gradients, and that only 30%-40% of the deglacial increases are related to changes in ice volume. On the precessional band, higher upper OHC correlates with oxygen isotope enrichments in IPWP surface water and concomitant depletion in East Asian precipitation as recorded in Chinese speleothems. Using an isotope-enabled air-sea coupled model, we suggest that on precessional timescales, variations in IPWP upper OHC, more than surface temperature, act to amplify the ocean-continent hydrological cycle via the convergence of moisture and latent heat. From an energetic viewpoint, the coupling of upper OHC and monsoon variations, both coordinated by insolation changes on orbital timescales, is critical for regulating the global hydroclimate.

2.
Am J Physiol Cell Physiol ; 326(4): C1106-C1119, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38344766

RESUMO

Intrauterine infection during pregnancy can enhance uterine contractions. A two-pore K+ channel TREK1 is crucial for maintaining uterine quiescence and reducing contractility, with its properties regulated by pH changes in cell microenvironment. Meanwhile, the sodium hydrogen exchanger 1 (NHE1) plays a pivotal role in modulating cellular pH homeostasis, and its activation increases smooth muscle tension. By establishing an infected mouse model of Escherichia coli (E. coli) and lipopolysaccharide (LPS), we used Western blotting, real-time quantitative polymerase chain reaction, and immunofluorescence to detect changes of TREK1 and NHE1 expression in the myometrium, and isometric recording measured the uterus contraction. The NHE1 inhibitor cariporide was used to explore the effect of NHE1 on TREK1. Finally, cell contraction assay and siRNA transfection were performed to clarify the relationship between NHE1 and TREK1 in vitro. We found that the uterine contraction was notably enhanced in infected mice with E. coli and LPS administration. Meanwhile, TREK1 expression was reduced, whereas NHE1 expression was upregulated in infected mice. Cariporide alleviated the increased uterine contraction and promoted myometrium TREK1 expression in LPS-injected mice. Furthermore, suppression of NHE1 with siRNA transfection inhibited the contractility of uterine smooth muscle cells and activated the TREK1. Altogether, our findings indicate that infection increases the uterine contraction by downregulating myometrium TREK1 in mice, and the inhibition of TREK1 is attributed to the activation of NHE1.NEW & NOTEWORTHY Present work found that infection during pregnancy will increase myometrium contraction. Infection downregulated NHE1 and followed TREK1 expression and activation decrease in myometrium, resulting in increased myometrium contraction.


Assuntos
Guanidinas , Lipopolissacarídeos , Miométrio , Canais de Potássio de Domínios Poros em Tandem , Trocador 1 de Sódio-Hidrogênio , Sulfonas , Animais , Feminino , Camundongos , Gravidez , Escherichia coli , Lipopolissacarídeos/toxicidade , Miométrio/metabolismo , RNA Interferente Pequeno/metabolismo , Contração Uterina/fisiologia , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Trocador 1 de Sódio-Hidrogênio/metabolismo
3.
J Biol Chem ; 299(10): 105232, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37690690

RESUMO

After adult mammalian central nervous system injury, axon regeneration is extremely limited or absent, resulting in persistent neurological deficits. Axon regeneration failure is due in part to the presence of inhibitory proteins, including NogoA (Rtn4A), from which two inhibitory domains have been defined. When these inhibitory domains are deleted, but an amino-terminal domain is still expressed in a gene trap line, mice show axon regeneration and enhanced recovery from injury. In contrast, when there is no amino-terminal Nogo-A fragment in the setting of inhibitory domain deletion, then axon regeneration and recovery are indistinguishable from WT. These data indicated that an amino-terminal Nogo-A fragment derived from the gene trap might promote axon regeneration, but this had not been tested directly and production of this fragment without gene targeting was unclear. Here, we describe posttranslation production of an amino-terminal fragment of Nogo-A from the intact gene product. This fragment is created by proteolysis near amino acid G214-N215 and levels are enhanced by axotomy. Furthermore, this fragment promotes axon regeneration in vitro and acts cell autonomously in neurons, in contrast to the inhibitory extracellular action of other Nogo-A domains.Proteins interacting with the amino-terminal Nogo-A fragment by immunoprecipitation include HSPA8 (HSC70, HSP7C). Suppression of HSPA8 expression by shRNA decreases axon regeneration from cerebral cortical neurons and overexpression increases axon regeneration. Moreover, the amino-terminal Nogo-A fragment increases HSPA8 chaperone activity. These data provide an explanation for varied results in different gene-targeted Nogo-A mice, as well as revealing an axon regeneration promoting domain of Nogo-A.


Assuntos
Axônios , Proteínas da Mielina , Animais , Camundongos , Axônios/metabolismo , Inibidores do Crescimento/metabolismo , Mamíferos/metabolismo , Proteínas da Mielina/genética , Proteínas da Mielina/metabolismo , Regeneração Nervosa/fisiologia , Proteínas Nogo/genética , Proteínas Nogo/metabolismo , Proteólise , Feminino , Camundongos Endogâmicos C57BL
4.
Exp Eye Res ; 241: 109837, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38382576

RESUMO

The lens is an avascular tissue, where epithelial cells (LECs) are the primary living cells. The role of LECs-derived exosomes (LEC-exos) is largely unknown. In our study, we determined the anti-angiogenic role of LEC-exos, manifested as regressed retinal neovascularization (NV) using the oxygen-induced retinopathy (OIR), and reduced choroidal NV size and pathological vascular leakage using the laser-induced choroidal neovascularization (laser-induced CNV). Furthermore, the activation and accumulation of microglia were also restricted by LEC-exos. Based on Luminex multiplex assays, the expressions of chemokines such as SCYB16/CXCL16, MCP-1/CCL2, I-TAC/CXCL11, and MIP 3beta/CCL19 were decreased after treatment with LEC-exos. Transwell assays showed that LEC-exos restricted the migration of the mouse microglia cell line (BV2 cells). After incubation with LEC-exos-treated BV2 cells, human umbilical vein endothelial cells (hUVECs) were collected for further evaluation using tube formation, Transwell assays, and 5-ethynyl-2'-deoxyuridine (EDU) assays. Using in vitro experiments, the pro-angiogenic effect of microglia was restricted by LEC-exos. Hence, it was investigated that LEC-exos attenuated ocular NV, which might attribute to the inhibition of microglial activation and accumulation.


Assuntos
Neovascularização de Coroide , Exossomos , Células-Tronco Mesenquimais , Camundongos , Animais , Humanos , Microglia , Exossomos/metabolismo , Angiogênese , Neovascularização Fisiológica/fisiologia , Células Endoteliais da Veia Umbilical Humana , Neovascularização de Coroide/metabolismo
5.
FASEB J ; 37(10): e23192, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37682530

RESUMO

Abnormal ocular neovascularization, a major pathology of eye diseases, leads to severe visual loss. The role of lens epithelial cell (LEC)-derived exosomes (Lec-exo) is largely unknown. Thus, we aimed to investigate whether Lec-exo can inhibit abnormal ocular neovascularization and explore the possible mechanisms. In our study, we proved the first evidence that exosomes derived from LECs attenuated angiogenesis in both oxygen-induced retinopathy and laser-induced choroidal neovascularization mice models. Further in vitro experiments proved that Lec-exo inhibited proliferation, migration, and tube formation capability of human umbilical vein endothelial cells in high glucose condition. Further high-throughput miRNAs sequencing analysis detected that miR-146a-5p was enriched in Lec-exo. Mechanistically, exosomal miR-146a-5p was delivered to endothelial cells and bound to the NRAS coding sequence, which subsequently inactivated AKT/ERK signaling pathway. We successfully elucidated the function of Lec-exo in inhibiting abnormal ocular neovascularization, which may offer a promising strategy for treatment of abnormal ocular neovascularization.


Assuntos
Neovascularização de Coroide , Exossomos , MicroRNAs , Humanos , Animais , Camundongos , Células Epiteliais , Neovascularização de Coroide/genética , Células Endoteliais da Veia Umbilical Humana , MicroRNAs/genética
6.
Biomacromolecules ; 25(5): 3190-3199, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38693753

RESUMO

Intracellular bacteria in dormant states can escape the immune response and tolerate high-dose antibiotic treatment, leading to severe infections. To overcome this challenge, cascade-targeted nanoplatforms that can target macrophages and intracellular bacteria, exhibiting synergetic antibiotic/reactive oxygen species (ROS)/nitric oxide (NO)/immunotherapy, were developed. These nanoplatforms were fabricated by encapsulating trehalose (Tr) and vancomycin (Van) into phosphatidylserine (PS)-coated poly[(4-allylcarbamoylphenylboric acid)-ran-(arginine-methacrylamide)-ran-(N,N'-bisacryloylcystamine)] nanoparticles (PABS), denoted as PTVP. PS on PTVP simulates a signal of "eat me" to macrophages to promote cell uptake (the first-step targeting). After the uptake, the nanoplatform in the acidic phagolysosomes could release Tr, and the exposed phenylboronic acid on the nanoplatform could target bacteria (the second-step targeting). Nanoplatforms can release Van in response to infected intracellular overexpressed glutathione (GSH) and weak acid microenvironment. l-arginine (Arg) on the nanoplatforms could be catalyzed by upregulated inducible nitric oxide synthase (iNOS) in the infected macrophages to generate nitric oxide (NO). N,N'-Bisacryloylcystamine (BAC) on nanoplatforms could deplete GSH, allow the generation of ROS in macrophages, and then upregulate proinflammatory activity, leading to the reinforced antibacterial capacity. This nanoplatform possesses macrophage and bacteria-targeting antibiotic delivery, intracellular ROS, and NO generation, and pro-inflammatory activities (immunotherapy) provides a new strategy for eradicating intracellular bacterial infections.


Assuntos
Antibacterianos , Nanopartículas , Óxido Nítrico , Espécies Reativas de Oxigênio , Espécies Reativas de Oxigênio/metabolismo , Óxido Nítrico/metabolismo , Antibacterianos/farmacologia , Antibacterianos/química , Camundongos , Animais , Células RAW 264.7 , Nanopartículas/química , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/imunologia , Imunoterapia/métodos , Vancomicina/farmacologia , Vancomicina/química , Vancomicina/administração & dosagem , Infecções Bacterianas/tratamento farmacológico , Trealose/química , Trealose/farmacologia
7.
Fish Shellfish Immunol ; 148: 109505, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38521144

RESUMO

The E11 cell line, derived from striped snakehead fish (Channa striata), possesses a distinctive feature: it is persistently infected with a C-type retrovirus. Notably, it exhibits high permissiveness to piscine nodavirus and the emerging tilapia lake virus (TiLV). Despite its popularity in TiLV research, the absence of genome assembly for the E11 cell line and Channa striata has constrained research on host-virus interactions. This study aimed to fill this gap by sequencing, assembling, and annotating the E11 cell line genome. Our efforts yielded a 600.5 Mb genome including 24 chromosomes with a BUSCO score of 98.8%. In addition, the complete proviral DNA sequence of snakehead retrovirus (SnRV) was identified in the E11 cell genome. Comparative genomic analysis between the E11 cell line and another snakehead species Channa argus revealed the loss of many immune-related gene families in the E11 cell genome, indicating a compromised immune response. We also conducted transcriptome analysis of mock- and TiLV-infected E11 cells, unveiling new perspectives on virus-virus and host-virus interactions. The TiLV infection suppressed the high expression of SnRV in E11 cells, and activated some other endogenous retroviruses. The protein-coding gene comparison revealed a pronounced up-regulation of genes involved in immune response, alongside a down-regulation of genes associated with specific metabolic processes. In summary, the genome assembly and annotation of the E11 cell line provide valuable resources to understand the SnRV and facilitate further studies on nodavirus and TiLV. The RNA-seq profiles shed light on the cellular mechanisms employed by fish cells in response to viral challenges, potentially guiding the development of therapeutic strategies against TiLV in aquaculture. This study also provides the first insights into the viral transcriptome profiles of endogenous SnRV and evading TiLV, enhancing our understanding of host-virus interactions in fish.


Assuntos
Doenças dos Peixes , Tilápia , Vírus , Animais , Retroviridae , Cromossomos , Perfilação da Expressão Gênica/veterinária
8.
J Nanobiotechnology ; 22(1): 56, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38336783

RESUMO

Diabetic retinopathy (DR) is a vision-threatening diabetic complication that is characterized by microvasculature impairment and immune dysfunction. The present study demonstrated that M2 microglia intensively participated in retinal microangiopathy in human diabetic proliferative membranes, mice retinas, retinas of mice with oxygen-induced retinopathy (OIR) mice, and retinas of streptozotocin-induced DR mice. Further in vivo and in vitro experiments showed that exosomes derived from M2 polarized microglia (M2-exo) could reduce pericyte apoptosis and promote endothelial cell proliferation, thereby promoting vascular remodeling and reducing vascular leakage from the diabetic retina. These effects were further enhanced by M2-exo that facilitated M2 polarization of retinal microglia. Collectively, the study demonstrated the capability of M2-exo to induce retinal microvascular remodeling, which may provide a new therapeutic strategy for the treatment of DR.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Exossomos , Camundongos , Animais , Humanos , Retinopatia Diabética/tratamento farmacológico , Retinopatia Diabética/etiologia , Remodelação Vascular , Microglia , Retina
9.
Langenbecks Arch Surg ; 409(1): 54, 2024 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-38321184

RESUMO

BACKGROUND: This study was to compare the safety and efficacy of different lymphadenectomy methods in patients with pancreatic head cancer undergoing pancreaticoduodenectomy (PD). MATERIAL AND METHODS: A total of 150 patients were included in this study. Patients were divided into Group A (n = 79), Group B (n = 44), and Group C (n = 27) according to the different lymphadenectomy methods. The clinical endpoint was time to progression (TTP) and overall survival (OS). Postoperative complications of different lymphadenectomy methods were compared respectively. TTP and OS of the three groups were compared by Kaplan-Meier curves. RESULTS: There were no significant differences between the three groups in operative time (P = 0.300), death in the hospital (P = 0.253), postoperative hemorrhage (P = 0.863), postoperative pancreatic fistula (POPF) B/C (P = 0.306), bile leakage (P = 0.215), intestinal fistula (P = 0.177), lymphatic leakage (P = 0.267), delayed gastric emptying [(DGE) (P = 0.283)], ICU stay (P = 0.506), and postoperative hospital stay [(PHS) (P = 0.810)]. Median TTP in Groups B and C was significantly longer than in Group A (log-rank test, A vs B: P = 0.0005, A vs C: P = 0.0001). Median OS between the three groups has no statistical difference (P = 0.1546). CONCLUSIONS: Extended lymphadenectomy methods based on the TRIANGLE do not increase perioperative complications significantly and can effectively delay tumor progression in patients with pancreatic head cancer.


Assuntos
Pâncreas , Neoplasias Pancreáticas , Humanos , Pâncreas/cirurgia , Neoplasias Pancreáticas/cirurgia , Pancreaticoduodenectomia/métodos , Fístula Pancreática/etiologia , Complicações Pós-Operatórias/etiologia , Excisão de Linfonodo/métodos
10.
Sensors (Basel) ; 24(12)2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38931789

RESUMO

Joint source-channel coding (JSCC) based on deep learning has shown significant advancements in image transmission tasks. However, previous channel-adaptive JSCC methods often rely on the signal-to-noise ratio (SNR) of the current channel for encoding, which overlooks the neural network's self-adaptive capability across varying SNRs. This paper investigates the self-adaptive capability of deep learning-based JSCC models to dynamically changing channels and introduces a novel method named Channel-Blind JSCC (CBJSCC). CBJSCC leverages the intrinsic learning capability of neural networks to self-adapt to dynamic channels and diverse SNRs without relying on external SNR information. This approach is advantageous, as it is not affected by channel estimation errors and can be applied to one-to-many wireless communication scenarios. To enhance the performance of JSCC tasks, the CBJSCC model employs a specially designed encoder-decoder. Experimental results show that CBJSCC outperforms existing channel-adaptive JSCC methods that depend on SNR estimation and feedback, both in additive white Gaussian noise environments and under slow Rayleigh fading channel conditions. Through a comprehensive analysis of the model's performance, we further validate the robustness and adaptability of this strategy across different application scenarios, with the experimental results providing strong evidence to support this claim.

11.
Zhongguo Zhong Yao Za Zhi ; 49(2): 403-411, 2024 Jan.
Artigo em Zh | MEDLINE | ID: mdl-38403316

RESUMO

Based on the concept of quality by design(QbD), this study optimized the processing technology of Ilicis Rotundae Cortex. According to the processing method and ingredient requirements of Ilicis Rotundae Cortex in the Chinese Pharmacopoeia, the content of syringin and pedunculoside, alcohol extract, fragmentation rate, and moisture content were taken as the critical quality attributes(CQAs). The soaking time, moistening time, and drying time were taken as critical process parameters(CPPs) by single factor tests. The weight coefficients of CQAs were determined by the analytic hierarchy process(AHP)-entropy weighting method, and the comprehensive score was calculated. With the comprehensive score as the response value, Box-Behnken design was employed to establish a mathematical model between CPPs and CQAs, and the design space for the processing of Ilicis Rotundae Cortex was built and verified. The results of ANOVA showed that the mathematical model had the P value below 0.05, the lack of fit greater than 0.05, adjusted R~2=0.910 5, and predicted R~2=0.831 0, which indicated that the proposed model had statistical significance and good prediction performance. Considering the factors in production, the best processing conditions of Ilicis Rotundae Cortex were decoction pieces of about 1 cm soaking for 1 h, moistening for 4 h, and drying at 60-70 ℃ in a blast drier for 2 h. The optimized processing technology of Ilicis Rotundae Cortex was stable and feasible, which can provide a reference for the standardized preparation and stable quality of Ilicis Rotundae Cortex.


Assuntos
Medicamentos de Ervas Chinesas , Casca de Planta , Tecnologia , Etanol
12.
J Am Chem Soc ; 145(39): 21231-21241, 2023 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-37748094

RESUMO

Zeolite nonclassical growth via particle attachment has been proposed for two decades, yet the attachment mechanism and kinetic regulation remain elusive. Here, nonclassical growth of an MFI-type zeolite has been achieved by using amorphous protozeolite (PZ) nanoparticles containing encapsulated TPA+ templates and abundant silanols (Si-OH) as sole precursors under hydrothermal conditions. The silanol characteristics of the precursor were studied by two-dimensional (2D) solid-state nuclear magnetic resonance (NMR) correlation spectroscopy, which were proven to play critical roles in determining precursor attachment behavior and crystal growth orientation. Under mechanical ball-milling or tablet-pressing process, pressure drove the fusion of spherical PZ into platelet-like integrated PZ (IPZ) coupled with transformations of external silanols from evenly distributed to curvature-dependent distributed and internal silanols from isolated to spatially proximate. Compared to isolated silanols, the spatially proximate silanols possessed a stronger correlation with TPA+, benefiting the formation of Si-O-Si bonds via silanol condensation. Subsequently, driven by minimization of surface energy, particle attachment of the platelet-like IPZ precursor preferentially occurred at high-curvature surfaces with high-density silanols, leading to anisotropic rates of nonclassical growth and thus the formation of high-aspect-ratio MFI-type zeolite nanosheets. Advanced electron microscopy provided direct evidence of attachment of amorphous IPZ precursors to crystalline intermediate surfaces along the c-axis direction with the formation of amorphous-crystalline interfaces, followed by interface elimination and structural evolution to a single-crystalline phase. Our findings not only unravel the zeolite nonclassical growth mechanism but also reveal the critical role of silanol chemistry in kinetic regulation, which is of great importance for pursuing a tailored zeolite synthesis.

13.
J Am Chem Soc ; 145(50): 27838-27849, 2023 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-38059465

RESUMO

Hydrogen sulfide (H2S) has shown promise for gas therapy. However, it is still controversial whether H2S can remodel the tumor microenvironment (TME) and induce robust antitumor immunity. Here, a tumor-targeting and TME-responsive "smart" lipid nanoparticle (1-JK-PS-FA) is presented, which is capable of delivering and releasing H2S specifically in tumor tissues for on-demand H2S gas and photodynamic immunotherapy. 1-JK-PS-FA enables a burst release of H2S in the acidic TME, which promptly reduces the embedded organic electrochromic materials and consequently switches on near-infrared fluorescence and photodynamic activity. Furthermore, we found that high levels of H2S can reprogram the TME by reducing tumor interstitial fluid pressure, promoting angiogenesis, increasing vascular permeability, ameliorating hypoxia, and reducing immunosuppressive conditions. This leads to increased tumor uptake of 1-JK-PS-FA, thereby enhancing PDT efficacy and eliciting strong immunogenic cell death during 808 nm laser irradiation. Therefore, 1-JK-PS-FA permits synergistic H2S gas and photodynamic immunotherapy, effectively eradicating orthotopic breast tumors and preventing tumor metastasis and recurrence. This work showcases the capacity of H2S to reprogram the TME to enhance H2S gas and immunotherapy.


Assuntos
Neoplasias Mamárias Animais , Nanopartículas , Neoplasias , Fotoquimioterapia , Animais , Microambiente Tumoral , Imunoterapia , Transporte Biológico , Linhagem Celular Tumoral
14.
J Am Chem Soc ; 145(44): 24116-24125, 2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-37783464

RESUMO

All-solid-state batteries with a high energy density and safety are desirable candidates for next-generation energy storage applications. However, conventional solid electrolytes for all-solid-state batteries encounter limitations such as poor ionic conduction, interfacial compatibility, instability, and high cost. Herein, taking advantage of the ingenious capability of zeolite to incorporate functional guests in its void space, we present an innovative ionic activation strategy based on the "guest wrench" mechanism, by introducing a pair of cation and anion of LiTFSI-based guest species (GS) into the supercage of the LiX zeolite, to fabricate a zeolite membrane (ZM)-based solid electrolyte (GS-ZM) with high Li ionic conduction and interfacial compatibility. The restriction of zeolite frameworks toward the framework-associated Li ions is significantly reduced through the dynamic coordination of Li ions with the "oxygen wrench" of TFSI- at room temperature as shown by experiments and Car-Parrinello molecular dynamics simulations. Consequently, the GS-ZM shows an ∼100% increase in ionic conductivity compared with ZM and an outstanding Li+ transference number of 0.97. Remarkably, leveraging the superior ionic conduction of GS-ZM with the favorable interface structure between GS-ZM and electrodes, the assembled all-solid-state Li-ion and Li-air batteries based on GS-ZM exhibit the best-level electrochemical performance much superior to batteries based on liquid electrolytes: a capacity retention of 99.3% after 800 cycles at 1 C for all-solid-state Li-ion batteries and a cycle life of 909 cycles at 500 mA g-1 for all-solid-state Li-air batteries. The mechanistic discovery of a "guest wrench" in zeolite will significantly enhance the adaptability of zeolite-based electrolytes in a variety of all-solid-state energy storage systems with high performance, high safety, and low cost.

15.
Reproduction ; 166(1): 55-64, 2023 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-37184053

RESUMO

In brief: During pregnancy, uterine kept quiescence along with uterine overdistention before labor. Prolonged stretching induced uterus myometrial hypoxia, increased TREK1 expression, and relaxed the myometrium, which may contribute to uterine quiescence and atony during pregnancy. Abstract: The mechanisms underlying pre-labor uterine quiescence and uterine atony during overdistention are unclear. TREK1 (a two-pore domain potassium channel) and hypoxia-inducible factor-1α (HIF-1α) are activated by mechanical stretch, and their expression is upregulated by decreased uterine contractility. HIF-1α is a nuclear factor which regulates numerous target proteins, but whether it regulates TREK1 during the uterine stretch to cause uterine quiescence and/or atony is unclear. We investigated uterine contractility at different gestational stages in rats, as well as in non-pregnant uteri, which were induced by prolonged stretching and hypoxia. We also assessed the effects of incubating the uteri with or without echinomycin or l-methionine. Moreover, we analyzed HIF-1α and TREK1 expression levels in each group, as well as at various gestational stages of pregnant human uteri. We found that contractility was significantly decreased in pregnant uteri when compared with non-pregnant uteri, and this decrease was associated with increases in HIF-1α and TREK1 expression levels. HIF-1α and TREK1 expression levels in human uteri increased with the gestational length. Decreased uterine contractility and increased HIF-1α and TREK1 expression levels were also observed in non-pregnant rat uteri under 8 g of stretching tension or hypoxia. Inhibition of hypoxia with echinomycin restored normal uterine contractility, while HIF-1α and TREK1 protein expression remained reduced. TREK1 inhibition with l-methionine also restored uterine contractility under tension or hypoxia. In conclusion, we demonstrated that prolonged stretching induces myometrial hypoxia, increases TREK1 expression, and relaxes the myometrium, which may contribute to uterine quiescence and atony.


Assuntos
Equinomicina , Trabalho de Parto , Canais de Potássio de Domínios Poros em Tandem , Animais , Feminino , Humanos , Gravidez , Ratos , Equinomicina/farmacologia , Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Trabalho de Parto/fisiologia , Miométrio/fisiologia , Útero , Canais de Potássio de Domínios Poros em Tandem/fisiologia
16.
Environ Sci Technol ; 57(10): 4342-4353, 2023 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-36864006

RESUMO

The association of poorly crystalline iron (hydr)oxides with organic matter (OM), such as extracellular polymeric substances (EPS), exerts a profound effect on Fe and C cycles in soils and sediments, and their behaviors under sulfate-reducing conditions involve complicated mineralogical transformations. However, how different loadings and types of EPS and water chemistry conditions affect the sulfidation still lacks quantitative and systematic investigation. We here synthesized a set of ferrihydrite-organic matter (Fh-OM) coprecipitates with various model compounds for plant and microbial exopolysaccharides (polygalacturonic acids, alginic acid, and xanthan gum) and bacteriogenic EPS (extracted from Bacillus subtilis). Combining wet chemical analysis, X-ray diffraction, and X-ray absorption spectroscopic techniques, we systematically studied the impacts of C and S loadings by tracing the temporal evolution of Fe mineralogy and speciation in aqueous and solid phases. Our results showed that the effect of added OM on sulfidation of Fh-OM coprecipitates is interrelated with the amount of loaded sulfide. Under low sulfide loadings (S(-II)/Fe < 0.5), transformation to goethite and lepidocrocite was the main pathway of ferrihydrite sulfidation, which occurs more strongly at pH 6 compared to that at pH 7.5, and it was promoted and inhibited at low and high C/Fe ratios, respectively. While under high sulfide loadings (S(-II)/Fe > 0.5), the formation of secondary Fe-S minerals such as mackinawite and pyrite dominated ferrihydrite sulfidation, and it was inhibited with increasing C/Fe ratios. Furthermore, all three synthetic EPS proxies unanimously inhibited mineral transformation, while the microbiogenic EPS has a more potent inhibitory effect than synthetic EPS proxies compared at equivalent C/Fe loadings. Collectively, our results suggest that the quantity and chemical characteristics of the associated OM have a strong and nonlinear influence on the extent and pathways of mineralogical transformations of Fh-OM sulfidation.


Assuntos
Carbono , Matriz Extracelular de Substâncias Poliméricas , Oxirredução , Compostos Férricos/química , Minerais/química , Enxofre , Água
17.
Plant Cell Rep ; 42(12): 1891-1906, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37743376

RESUMO

KEY MESSAGE: The study of the origin, evolution, and diversification of the wall-associated kinase gene family in plants facilitates their functional investigations in the future. Wall-associated kinases (WAKs) make up one subfamily of receptor-like kinases (RLKs), and function directly in plant cell elongation and responses to biotic and abiotic stresses. The biological functions of WAKs have been extensively characterized in angiosperms; however, the origin and evolutionary history of the WAK family in green plants remain unclear. Here, we performed a comprehensive analysis of the WAK family to reveal its origin, evolution, and diversification in green plants. In total, 1061 WAK genes were identified in 37 species from unicellular algae to multicellular plants, and the results showed that WAK genes probably originated before bryophyte differentiation and were widely distributed in land plants, especially angiosperms. The phylogeny indicated that the land plant WAKs gave rise to five clades and underwent lineage-specific expansion after species differentiation. Cis-acting elements and expression patterns analyses of WAK genes in Arabidopsis and rice demonstrated the functional diversity of WAK genes in these two species. Many gene gains and losses have occurred in angiosperms, leading to an increase in the number of gene copies. The evolutionary trajectory of the WAK family during polyploidization was uncovered using Gossypium species. Our results provide insights into the evolution of WAK genes in green plants, facilitating their functional investigations in the future.


Assuntos
Arabidopsis , Plantas , Plantas/genética , Genes de Plantas/genética , Arabidopsis/genética , Família Multigênica
18.
Int J Mol Sci ; 24(11)2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37298464

RESUMO

Salinity is a major abiotic stress that restricts cotton growth and affects fiber yield and quality. Although studies on salt tolerance have achieved great progress in cotton since the completion of cotton genome sequencing, knowledge about how cotton copes with salt stress is still scant. S-adenosylmethionine (SAM) plays important roles in many organelles with the help of the SAM transporter, and it is also a synthetic precursor for substances such as ethylene (ET), polyamines (PAs), betaine, and lignin, which often accumulate in plants in response to stresses. This review focused on the biosynthesis and signal transduction pathways of ET and PAs. The current progress of ET and PAs in regulating plant growth and development under salt stress has been summarized. Moreover, we verified the function of a cotton SAM transporter and suggested that it can regulate salt stress response in cotton. At last, an improved regulatory pathway of ET and PAs under salt stress in cotton is proposed for the breeding of salt-tolerant varieties.


Assuntos
S-Adenosilmetionina , Tolerância ao Sal , Tolerância ao Sal/genética , Estresse Salino , Estresse Fisiológico/genética , Gossypium/genética , Regulação da Expressão Gênica de Plantas
19.
Angew Chem Int Ed Engl ; 62(48): e202313101, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-37792288

RESUMO

The selective hydrogenation of alkynes to alkenes is a crucial step in the synthesis of fine chemicals. However, the widely utilized palladium (Pd)-based catalysts often suffer from poor selectivity. In this work, we demonstrate a carbonization-reduction method to create palladium carbide subnanometric species within pure silicate MFI zeolite. The carbon species can modify the electronic and steric characteristics of Pd species by forming the predominant Pd-C4 structure and, meanwhile, facilitate the desorption of alkenes by forming the Si-O-C structure with zeolite framework, as validated by the state-of-the-art characterizations and theoretical calculations. The developed catalyst shows superior performance in the selective hydrogenation of alkynes over mild conditions (298 K, 2 bar H2 ), with 99 % selectivity to styrene at a complete conversion of phenylacetylene. In contrast, the zeolite-encapsulated carbon-free Pd catalyst and the commercial Lindlar catalyst show only 15 % and 14 % selectivity to styrene, respectively, under identical reaction conditions. The zeolite-confined Pd-carbide subnanoclusters promise their superior properties in semihydrogenation of alkynes.

20.
Angew Chem Int Ed Engl ; 62(49): e202312131, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-37819839

RESUMO

Creation of intrapenetrated mesopores with open highway from external surface into the interior of zeolite crystals are highly desirable that can significantly improve the molecular transport and active sites accessibility of microporous zeolites to afford enhanced catalytic properties. Here, different from traditional zeolite-seeded methods that generally produced isolated mesopores in zeolites, nanosized amorphous protozeolites with embryo structure of zeolites were used as seeds for the construction of single-crystalline hierarchical ZSM-5 zeolites with intrapenetrated mesopores (mesopore volume of 0.51 cm3 g-1 ) and highly complete framework. In this strategy, in contrast to the conventional synthesis, only a small amount of organic structure directing agents and a low crystallization temperature were adopted to promise the protozeolites as the dominant growth directing sites to induce crystallization. The protozeolite nanoseeds provided abundant nucleation sites for surrounding precursors to be crystallized, followed by oriented coalescence of crystallites resulting in the formation of intrapenetrated mesopores. The as-prepared hierarchical ZSM-5 zeolites exhibited ultra-long lifetime of 443.9 hours and a high propylene selectivity of 47.92 % at a WHSV of 2 h-1 in the methanol-to-propylene reaction. This work provides a facile protozeolite-seeded strategy for the synthesis of intrapenetrated hierarchical zeolites that are highly effective for catalytic applications.

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