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1.
Nature ; 603(7903): 819-823, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35355005

RESUMEN

The natural habitats of microorganisms in the human microbiome, ocean and soil ecosystems are full of colloids and macromolecules. Such environments exhibit non-Newtonian flow properties, drastically affecting the locomotion of microorganisms1-5. Although the low-Reynolds-number hydrodynamics of swimming flagellated bacteria in simple Newtonian fluids has been well developed6-9, our understanding of bacterial motility in complex non-Newtonian fluids is less mature10,11. Even after six decades of research, fundamental questions about the nature and origin of bacterial motility enhancement in polymer solutions are still under debate12-23. Here we show that flagellated bacteria in dilute colloidal suspensions display quantitatively similar motile behaviours to those in dilute polymer solutions, in particular a universal particle-size-dependent motility enhancement up to 80% accompanied by a strong suppression of bacterial wobbling18,24. By virtue of the hard-sphere nature of colloids, whose size and volume fraction we vary across experiments, our results shed light on the long-standing controversy over bacterial motility enhancement in complex fluids and suggest that polymer dynamics may not be essential for capturing the phenomenon12-23. A physical model that incorporates the colloidal nature of complex fluids quantitatively explains bacterial wobbling dynamics and mobility enhancement in both colloidal and polymeric fluids. Our findings contribute to the understanding of motile behaviours of bacteria in complex fluids, which are relevant for a wide range of microbiological processes25 and for engineering bacterial swimming in complex environments26,27.


Asunto(s)
Coloides , Ecosistema , Bacterias , Humanos , Hidrodinámica , Polímeros
2.
Proc Natl Acad Sci U S A ; 120(48): e2310952120, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-37991946

RESUMEN

To swim through a viscous fluid, a flagellated bacterium must overcome the fluid drag on its body by rotating a flagellum or a bundle of multiple flagella. Because the drag increases with the size of bacteria, it is expected theoretically that the swimming speed of a bacterium inversely correlates with its body length. Nevertheless, despite extensive research, the fundamental size-speed relation of flagellated bacteria remains unclear with different experiments reporting conflicting results. Here, by critically reviewing the existing evidence and synergizing our own experiments of large sample sizes, hydrodynamic modeling, and simulations, we demonstrate that the average swimming speed of Escherichia coli, a premier model of peritrichous bacteria, is independent of their body length. Our quantitative analysis shows that such a counterintuitive relation is the consequence of the collective flagellar dynamics dictated by the linear correlation between the body length and the number of flagella of bacteria. Notably, our study reveals how bacteria utilize the increasing number of flagella to regulate the flagellar motor load. The collective load sharing among multiple flagella results in a lower load on each flagellar motor and therefore faster flagellar rotation, which compensates for the higher fluid drag on the longer bodies of bacteria. Without this balancing mechanism, the swimming speed of monotrichous bacteria generically decreases with increasing body length, a feature limiting the size variation of the bacteria. Altogether, our study resolves a long-standing controversy over the size-speed relation of flagellated bacteria and provides insights into the functional benefit of multiflagellarity in bacteria.


Asunto(s)
Movimiento , Natación , Movimiento/fisiología , Flagelos/fisiología , Rotación , Escherichia coli/fisiología
3.
Circulation ; 150(13): 981-993, 2024 Sep 24.
Artículo en Inglés | MEDLINE | ID: mdl-39166327

RESUMEN

BACKGROUND: Colchicine has been approved to reduce cardiovascular risk in patients with coronary heart disease on the basis of its potential benefits demonstrated in the COLCOT (Colchicine Cardiovascular Outcomes Trial) and LoDoCo2 (Low-Dose Colchicine 2) studies. Nevertheless, there are limited data available about the specific impact of colchicine on coronary plaques. METHODS: This was a prospective, single-center, randomized, double-blind clinical trial. From May 3, 2021, until August 31, 2022, a total of 128 patients with acute coronary syndrome aged 18 to 80 years with lipid-rich plaque (lipid pool arc >90°) detected by optical coherence tomography were included. The subjects were randomly assigned in a 1:1 ratio to receive either colchicine (0.5 mg once daily) or placebo for 12 months. The primary end point was the change in the minimal fibrous cap thickness from baseline to the 12-month follow-up. RESULTS: Among 128 patients, 52 in the colchicine group and 52 in the placebo group completed the study. The mean age of the 128 patients was 58.0±9.8 years, and 25.0% were female. Compared with placebo, colchicine therapy significantly increased the minimal fibrous cap thickness (51.9 [95% CI, 32.8 to 71.0] µm versus 87.2 [95% CI, 69.9 to 104.5] µm; difference, 34.2 [95% CI, 9.7 to 58.6] µm; P=0.006), and reduced average lipid arc (-25.2° [95% CI, -30.6° to -19.9°] versus -35.7° [95% CI, -40.5° to -30.8°]; difference, -10.5° [95% CI, -17.7° to -3.4°]; P=0.004), mean angular extension of macrophages (-8.9° [95% CI, -13.3° to -4.6°] versus -14.0° [95% CI, -18.0° to -10.0°]; difference, -6.0° [95% CI, -11.8° to -0.2°]; P=0.044), high-sensitivity C-reactive protein level (geometric mean ratio, 0.6 [95% CI, 0.4 to 1.0] versus 0.3 [95% CI, 0.2 to 0.5]; difference, 0.5 [95% CI, 0.3 to 1.0]; P=0.046), interleukin-6 level (geometric mean ratio, 0.8 [95% CI, 0.6 to 1.1] versus 0.5 [95% CI, 0.4 to 0.7]; difference, 0.6 [95% CI, 0.4 to 0.9]; P=0.025), and myeloperoxidase level (geometric mean ratio, 1.0 [95% CI, 0.8 to 1.2] versus 0.8 [95% CI, 0.7 to 0.9]; difference, 0.8 [95% CI, 0.6 to 1.0]; P=0.047). CONCLUSIONS: Our findings suggested that colchicine resulted in favorable effects on coronary plaque stabilization at optical coherence tomography in patients with acute coronary syndrome. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04848857.


Asunto(s)
Síndrome Coronario Agudo , Colchicina , Placa Aterosclerótica , Tomografía de Coherencia Óptica , Humanos , Colchicina/uso terapéutico , Femenino , Síndrome Coronario Agudo/tratamiento farmacológico , Síndrome Coronario Agudo/diagnóstico por imagen , Persona de Mediana Edad , Masculino , Placa Aterosclerótica/tratamiento farmacológico , Placa Aterosclerótica/diagnóstico por imagen , Método Doble Ciego , Anciano , Estudios Prospectivos , Adulto , Resultado del Tratamiento , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Enfermedad de la Arteria Coronaria/diagnóstico por imagen
4.
EMBO J ; 40(14): e107500, 2021 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-34046916

RESUMEN

The Staphylococcal Bap proteins sense environmental signals (such as pH, [Ca2+ ]) to build amyloid scaffold biofilm matrices via unknown mechanisms. We here report the crystal structure of the aggregation-prone region of Staphylococcus aureus Bap which adopts a dumbbell-shaped fold. The middle module (MM) connecting the N-terminal and C-terminal lobes consists of a tandem of novel double-Ca2+ -binding motifs involved in cooperative interaction networks, which undergoes Ca2+ -dependent order-disorder conformational switches. The N-terminal lobe is sufficient to mediate amyloid aggregation through liquid-liquid phase separation and maturation, and subsequent biofilm formation under acidic conditions. Such processes are promoted by disordered MM at low [Ca2+ ] but inhibited by ordered MM stabilized by Ca2+ binding, with inhibition efficiency depending on structural integrity of the interaction networks. These studies illustrate a novel protein switch in pathogenic bacteria and provide insights into the mechanistic understanding of Bap proteins in modulation of functional amyloid and biofilm formation, which could be implemented in the anti-biofilm drug design.


Asunto(s)
Amiloide/metabolismo , Proteínas Bacterianas/metabolismo , Biopelículas/crecimiento & desarrollo , Staphylococcus aureus/crecimiento & desarrollo , Staphylococcus aureus/metabolismo , Calcio/metabolismo , Agregación Celular/fisiología
5.
FASEB J ; 38(4): e23488, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38358359

RESUMEN

Myocardial infarction (MI) is defined as sudden ischemic death of myocardial tissue. Amphiregulin (Areg) regulates cell survival and is crucial for the healing of tissues after damage. However, the functions and mechanisms of Areg after MI remain unclear. Here, we aimed to investigate Areg's impact on myocardial remodeling. Mice model of MI was constructed and Areg-/- mice were used. Expression of Areg was analyzed using western blotting, RT-qPCR, flow cytometry, and immunofluorescence staining. Echocardiographic analysis, Masson's trichrome, and triphenyltetrazolium chloride staining were used to assess cardiac function and structure. RNA sequencing was used for unbiased analysis. Apoptosis and autophagy were determined by western blotting, TUNEL staining, electron microscopy, and mRFP-GFP-LC3 lentivirus. Lysosomal acidity was determined by Lysotracker staining. Areg was elevated in the infarct border zone after MI. It was mostly secreted by macrophages. Areg deficiency aggravated adverse ventricular remodeling, as reflected by worsening cardiac function, a lower survival rate, increased scar size, and interstitial fibrosis. RNA sequencing analyses showed that Areg related to the epidermal growth factor receptor (EGFR), phosphoinositide 3-kinase/protein kinase B (PI3K-Akt), mammalian target of rapamycin (mTOR) signaling pathways, V-ATPase and lysosome pathways. Mechanistically, Areg exerts beneficial effects via increasing lysosomal acidity to promote autophagosome clearance, and activating the EGFR/PI3K/Akt/mTOR signaling pathway, subsequently inhibiting excessive autophagosome formation and apoptosis in cardiomyocytes. This study provides a novel evidence for the role of Areg in inhibiting ventricular remodeling after MI by regulating autophagy and apoptosis and identifies Areg as a potential therapeutic target in ventricular remodeling after MI.


Asunto(s)
Infarto del Miocardio , Fosfatidilinositol 3-Quinasas , Animales , Ratones , Anfirregulina/genética , Apoptosis , Autofagia , Receptores ErbB , Mamíferos , Proteínas Proto-Oncogénicas c-akt , Serina-Treonina Quinasas TOR , Remodelación Ventricular
6.
FASEB J ; 38(1): e23386, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38112398

RESUMEN

CD4+ T-cell counts are increased and activated in patients with chronic heart failure (CHF), whereas regulatory T-cell (Treg) expansion is inhibited, probably due to aberrant T-cell receptor (TCR) signaling. TCR signaling is affected by protein tyrosine phosphatase nonreceptor type 22 (PTPN22) in autoimmune disorders, but whether PTPN22 influences TCR signaling in CHF remains unclear. This observational case-control study included 45 patients with CHF [18 patients with ischemic heart failure versus 27 patients with nonischemic heart failure (NIHF)] and 16 non-CHF controls. We used flow cytometry to detect PTPN22 expression, tyrosine phosphorylation levels, zeta-chain-associated protein kinase, 70 kDa (ZAP-70) inhibitory residue tyrosine 292 and 319 phosphorylation levels, and CD4+ T cell and Treg proportions. We conducted lentivirus-mediated PTPN22 RNA silencing in isolated CD4+ T cells. PTPN22 expression increased in the CD4+ T cells of patients with CHF compared with that in controls. PTPN22 expression was positively correlated with left ventricular end-diastolic diameter and type B natriuretic peptide but negatively correlated with left ventricular ejection fraction in the NIHF group. ZAP-70 tyrosine 292 phosphorylation was decreased, which correlated positively with PTPN22 overexpression in patients with NIHF and promoted early TCR signaling. PTPN22 silencing induced Treg differentiation in CD4+ T cells from patients with CHF, which might account for the reduced frequency of peripheral Tregs in these patients. PTPN22 is a potent immunomodulator in CHF and might play an essential role in the development of CHF by promoting early TCR signaling and impairing Treg differentiation from CD4+ T cells.


Asunto(s)
Insuficiencia Cardíaca , Receptores de Antígenos de Linfocitos T , Humanos , Estudios de Casos y Controles , Volumen Sistólico , Receptores de Antígenos de Linfocitos T/metabolismo , Función Ventricular Izquierda , Proteínas Tirosina Fosfatasas , Linfocitos T Reguladores , Tirosina , Proteína Tirosina Fosfatasa no Receptora Tipo 22/genética
7.
FASEB J ; 38(1): e23350, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38071600

RESUMEN

Lung diseases characterized by type 2 inflammation are reported to occur with a female bias in prevalence/severity in both humans and mice. This includes previous work examining multi-walled carbon nanotube (MWCNT)-induced eosinophilic inflammation, in which a more exaggerated M2a phenotype was observed in female alveolar macrophages (AMs) compared to males. The mechanisms responsible for this sex difference in AM phenotype are still unclear, but estrogen receptor (ER) signaling is a likely contributor. Accordingly, male AMs downregulated ERα expression after MWCNT exposure while female AMs did not. Thus, ER antagonist Fulvestrant was administered prior to MWCNT instillation. In females, Fulvestrant significantly attenuated MWCNT-induced M2a gene expression and eosinophilia without affecting IL-33. In males, Fulvestrant did not affect eosinophil recruitment but reduced IL-33 and M2a genes compared to controls. Regulation of cholesterol efflux and oxysterol synthesis is a potential mechanism through which estrogen promotes the M2a phenotype. Levels of oxysterols 25-OHC and 7α,25-OHC were higher in the airways of MWCNT-exposed males compared to MWCNT-females, which corresponds with the lower IL-1ß production and greater macrophage recruitment previously observed in males. Sex-based changes in cholesterol efflux transporters Abca1 and Abcg1 were also observed after MWCNT exposure with or without Fulvestrant. In vitro culture with estrogen decreased cellular cholesterol and increased the M2a response in female AMs, but did not affect cholesterol content in male AMs and reduced M2a polarization. These results reveal the modulation of (oxy)sterols as a potential mechanism through which estrogen signaling may regulate AM phenotype resulting in sex differences in downstream respiratory inflammation.


Asunto(s)
Pulmón , Nanotubos de Carbono , Femenino , Masculino , Humanos , Animales , Ratones , Pulmón/metabolismo , Interleucina-33/metabolismo , Nanotubos de Carbono/toxicidad , Caracteres Sexuales , Fulvestrant , Inflamación/inducido químicamente , Inflamación/metabolismo , Macrófagos/metabolismo , Colesterol/metabolismo , Ratones Endogámicos C57BL
8.
Proc Natl Acad Sci U S A ; 119(31): e2205469119, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35895684

RESUMEN

T regulatory (Treg) cells are essential for self-tolerance whereas they are detrimental for dampening the host anti-tumor immunity. How Treg cells adapt to environmental signals to orchestrate their homeostasis and functions remains poorly understood. Here, we identified that transcription factor EB (TFEB) is induced by host nutrition deprivation or interleukin (IL)-2 in CD4+ T cells. The loss of TFEB in Treg cells leads to reduced Treg accumulation and impaired Treg function in mouse models of cancer and autoimmune disease. TFEB intrinsically regulates genes involved in Treg cell differentiation and mitochondria function while it suppresses expression of proinflammatory cytokines independently of its established roles in autophagy. This coordinated action is required for mitochondria integrity and appropriate lipid metabolism in Treg cells. These findings identify TFEB as a critical regulator for orchestrating Treg generation and function, which may contribute to the adaptive responses of T cells to local environmental cues.


Asunto(s)
Adaptación Fisiológica , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Mitocondrias , Neoplasias , Linfocitos T Reguladores , Adaptación Fisiológica/genética , Adaptación Fisiológica/fisiología , Animales , Enfermedades Autoinmunes/inmunología , Autofagia/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/genética , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice/fisiología , Modelos Animales de Enfermedad , Interleucina-2/metabolismo , Ratones , Mitocondrias/genética , Mitocondrias/metabolismo , Neoplasias/inmunología , Linfocitos T Reguladores/inmunología , Ensayos Antitumor por Modelo de Xenoinjerto
9.
J Lipid Res ; 65(7): 100575, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38866327

RESUMEN

Lipids are components of cytomembranes that are involved in various biochemical processes. High-altitude hypoxic environments not only affect the body's energy metabolism, but these environments can also cause abnormal lipid metabolism involved in the hypoxia-induced cognitive impairment. Thus, comprehensive lipidomic profiling of the brain tissue is an essential step toward understanding the mechanism of cognitive impairment induced by hypoxic exposure. In the present study, mice showed reduced new-object recognition and spatial memory when exposed to hypobaric hypoxia for 1 day. Histomorphological staining revealed significant morphological and structural damage to the hippocampal tissue, along with prolonged exposure to hypobaric hypoxia. Dynamic lipidomics of the mouse hippocampus showed a significant shift in both the type and distribution of phospholipids, as verified by spatial lipid mapping. Collectively, a diverse and dynamic lipid composition in mice hippocampus was uncovered, which deepens our understanding of biochemical changes during sustained hypoxic exposure and could provide new insights into the cognitive decline induced by high-altitude hypoxia exposure.


Asunto(s)
Hipocampo , Hipoxia , Lipidómica , Animales , Hipocampo/metabolismo , Hipocampo/patología , Ratones , Lipidómica/métodos , Hipoxia/metabolismo , Masculino , Espectrometría de Masas , Lípidos/análisis , Ratones Endogámicos C57BL , Metabolismo de los Lípidos
10.
J Proteome Res ; 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39226440

RESUMEN

This investigation aims to employ Olink proteomics in analyzing the distinct serum proteins associated with postmenopausal osteoporosis (PMOP) and identifying prognostic markers for early detection of PMOP via molecular mechanism research on postmenopausal osteoporosis. Postmenopausal women admitted to Beijing Jishuitan Hospital were randomly selected and categorized into three groups based on their dual-energy X-ray absorptiometry (DXA) T-scores: osteoporosis group (n = 24), osteopenia group (n = 20), and normal bone mass group (n = 16). Serum samples from all participants were collected for clinical and bone metabolism marker measurements. Olink proteomics was utilized to identify differentially expressed proteins (DEPs) that are highly associated with postmenopausal osteoporosis. The functional analysis of DEPs was performed using Gene Ontology and Kyto Encyclopedia Genes and Genomes (KEGG). The biological characteristics of these proteins and their correlation with PMOP were subsequently analyzed. ROC curve analysis was performed to identify potential biomarkers with the highest diagnostic accuracy for early stage PMOP. Through Olink proteomics, we identified five DEPs highly associated with PMOP, including two upregulated and three downregulated proteins. TWEAK and CDCP1 markers exhibited the highest area under the curve (0.8188 and 0.8031, respectively). TWEAK and CDCP1 have the potential to serve as biomarkers for early prediction of postmenopausal osteoporosis.

11.
Immunology ; 172(4): 600-613, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38637948

RESUMEN

Immune cell infiltration is a significant pathological process in abdominal aortic aneurysms (AAA). T cells, particularly CD4+ T cells, are essential immune cells responsible for substantial infiltration of the aorta. Regulatory T cells (Tregs) in AAA have been identified as tissue-specific; however, the time, location, and mechanism of acquiring the tissue-specific phenotype are still unknown. Using single-cell RNA sequencing (scRNA-seq) on CD4+ T cells from the AAA aorta and spleen, we discovered heterogeneity among CD4+ T cells and identified activated, proliferating and developed aorta Tregs. These Tregs originate in the peripheral tissues and acquire the tissue-specific phenotype in the aorta. The identification of precursors for Tregs in AAA provides new insight into the pathogenesis of AAA.


Asunto(s)
Aneurisma de la Aorta Abdominal , Análisis de la Célula Individual , Linfocitos T Reguladores , Aneurisma de la Aorta Abdominal/inmunología , Aneurisma de la Aorta Abdominal/patología , Linfocitos T Reguladores/inmunología , Humanos , Animales , Masculino , Linfocitos T CD4-Positivos/inmunología , Ratones , Análisis de Secuencia de ARN , Bazo/inmunología , Activación de Linfocitos , Ratones Endogámicos C57BL
12.
J Am Chem Soc ; 146(26): 17931-17939, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38877992

RESUMEN

Complex micro/nanorobots may be constructed by integrating several independent, controlled nanomotors for high degrees of freedom of maneuvering and manipulation. However, designing nanomotors with distinctive responses to the same global stimuli is challenging due to the nanomotors' simple structure and limited material composition. In this work, we demonstrate that a nanomotor can be designed with the same principles of electronic circuits, where the motion of semiconductor particles can be controlled with synchronized electric and optical signals. This technique relies on transient bipolar photoelectrochemistry in semiconductor microparticles, where the reaction site selectivity is realized by modulating the light pulse in the time domain. Due to the microparticles' intrinsic resistance and surface capacitance, the nanomotors can be designed as an electronic circuit, enabling distinctive responses to the global electric/optical field and achieving the desired movement or deflection/rotation. This work gives new insight into the manipulation technique for independent and untethered nanomotor control. Ultimately, it exploits the potential for particle sorting based on geometry in time and frequency domain modulation.

13.
J Am Chem Soc ; 146(22): 15428-15437, 2024 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-38795044

RESUMEN

Chemical recycling to monomers (CRM) offers a promising closed-loop approach to transition from current linear plastic economy toward a more sustainable circular paradigm. Typically, this approach has focused on modulating the ceiling temperature (Tc) of monomers. Despite considerable advancements, polymers with low Tc often face challenges such as inadequate thermal stability, exemplified by poly(γ-butyrolactone) (PGBL) with a decomposition temperature of ∼200 °C. In contrast, floor temperature (Tf)-regulated polymers, particularly those synthesized via the ring-opening polymerization (ROP) of macrolactones, inherently exhibit enhanced thermodynamic stability as the temperature increases. However, the development of those Tf regulated chemically recyclable polymers remains relatively underexplored. In this context, by judicious design and efficient synthesis of a biobased macrocyclic diester monomer (HOD), we developed a type of Tf -regulated closed-loop chemically recyclable poly(ketal-ester) (PHOD). First, the entropy-driven ROP of HOD generated high-molar mass PHOD with exceptional thermal stability with a Td,5% reaching up to 353 °C. Notably, it maintains a high Td,5% of 345 °C even without removing the polymerization catalyst. This contrasts markedly with PGBL, which spontaneously depolymerizes back to the monomer above its Tc in the presence of catalyst. Second, PHOD displays outstanding closed-loop chemical recyclability at room temperature within just 1 min with tBuOK. Finally, copolymerization of pentadecanolide (PDL) with HOD generated high-performance copolymers (PHOD-co-PPDL) with tunable mechanical properties and chemical recyclability of both components.

14.
Small ; 20(3): e2304327, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37699748

RESUMEN

Flexible composite films have attracted considerable attention due to great potential for healthcare, telecommunication, and aerospace. However, it is still challenging to achieve high conductivity and multifunctional integration, mainly due to poorly designed composite structures of these films. Herein, a novel sandwich-structured assembly strategy is proposed to fabricate flexible composite thin films made of Ag nanowire (AgNW) core and MXene layers by combination of spray coating and vacuum filtration process. In this case, ultrathin MXene layers play crucial roles in constructing compact composite structures strongly anchored to substrate with extensive hydrogen-bonding interactions. The resultant sandwich-structured MXene/AgNW composite thin films (SMAFs) exhibit ultrahigh electrical conductivity (up to 27193 S cm-1 ), resulting in exceptional electromagnetic interference shielding effectiveness of 16 223.3 dB cm2 g-1 and impressive Joule heating performance with rapid heating rate of 10.4 °C s-1 . Moreover, the uniform SMAFs can also be facilely cut into kirigami-patterned interconnects, which indicate superior strain-insensitive conductance even after long-term exposure to extreme temperatures. The demonstrated strategy offers a significant paradigm to construct multifunctional composite thin films for next-generation integrated flexible electronics with practical applications.

15.
Bioinformatics ; 39(2)2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36727489

RESUMEN

MOTIVATION: Mammalian cells can be transcriptionally reprogramed to other cellular phenotypes. Controllability of such complex transitions in transcriptional networks underlying cellular phenotypes is an inherent biological characteristic. This network controllability can be interpreted by operating a few key regulators to guide the transcriptional program from one state to another. Finding the key regulators in the transcriptional program can provide key insights into the network state transition underlying cellular phenotypes. RESULTS: To address this challenge, here, we proposed to identify the key regulators in the transcriptional co-expression network as a minimum dominating set (MDS) of driver nodes that can fully control the network state transition. Based on the theory of structural controllability, we developed a weighted MDS network model (WMDS.net) to find the driver nodes of differential gene co-expression networks. The weight of WMDS.net integrates the degree of nodes in the network and the significance of gene co-expression difference between two physiological states into the measurement of node controllability of the transcriptional network. To confirm its validity, we applied WMDS.net to the discovery of cancer driver genes in RNA-seq datasets from The Cancer Genome Atlas. WMDS.net is powerful among various cancer datasets and outperformed the other top-tier tools with a better balance between precision and recall. AVAILABILITY AND IMPLEMENTATION: https://github.com/chaofen123/WMDS.net. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Algoritmos , Neoplasias , Animales , Transcriptoma , Neoplasias/genética , Oncogenes , Redes Reguladoras de Genes , Mamíferos/genética
16.
Opt Lett ; 49(4): 838-841, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38359195

RESUMEN

We experimentally establish a 3 × 3 cross-shaped micro-ring resonator (MRR) array-based photonic multiplexing architecture relying on silicon photonics to achieve parallel edge extraction operations in images for photonic convolution neural networks. The main mathematical operations involved are convolution. Precisely, a faster convolutional calculation speed of up to four times is achieved by extracting four feature maps simultaneously with the same photonic hardware's structure and power consumption, where a maximum computility of 0.742 TOPS at an energy cost of 48.6 mW and a convolution accuracy of 95.1% is achieved in an MRR array chip. In particular, our experimental results reveal that this system using parallel edge extraction operators instead of universal operators can improve the imaging recognition accuracy for CIFAR-10 dataset by 6.2% within the same computing time, reaching a maximum of 78.7%. This work presents high scalability and efficiency of parallel edge extraction chips, furnishing a novel, to the best of our knowledge, approach to boost photonic computing speed.

17.
Opt Lett ; 49(13): 3556-3559, 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38950208

RESUMEN

Optical image encryption has long been an important concept in the fields of photonic network processing and communication. Here, we propose a convolution-like operation-based optical image encryption algorithm exploiting a silicon photonic multiplexing architecture to achieve content security. Particularly, the encryption process is completed in a 3 × 3 cross-shaped photonic micro-ring resonator (MRR) array on chip. For the first time, to the best of our knowledge, this algorithm encodes information in an integrated intensity modulation, effectively reducing the encoding difficulty. Moreover, the high reliability and scalability of optical encryption are ensured using both linear and nonlinear operations on photonic chips according to characteristics of MRRs. As the encryption and decryption experiments show, the image restoration accuracy of our optical encryption algorithm exceeds 99% under real system noise at the pixel level, indicating its noise-robust property. Meanwhile, the peak signal-to-noise ratios of the restored and encrypted images are >60 and <15 dB, respectively, revealing both the high accuracy of the restored image and the small correlation between the encrypted and original images. This work adds to the rapidly expanding field of optical image encryption on photonic chips.

18.
Stem Cells ; 41(1): 77-92, 2023 01 30.
Artículo en Inglés | MEDLINE | ID: mdl-36208284

RESUMEN

Hypoxia as a microenvironment or niche stimulates proliferation of neural stem cells (NSCs). However, the underlying mechanisms remain elusive. Autophagy is a protective mechanism by which recycled cellular components and energy are rapidly supplied to the cell under stress. Whether autophagy mediates the proliferation of NSCs under hypoxia and how hypoxia induces autophagy remain unclear. Here, we report that hypoxia facilitates embryonic NSC proliferation through HIF-1/mTORC1 signaling pathway-mediated autophagy. Initially, we found that hypoxia greatly induced autophagy in NSCs, while inhibition of autophagy severely impeded the proliferation of NSCs in hypoxia conditions. Next, we demonstrated that the hypoxia core regulator HIF-1 was necessary and sufficient for autophagy induction in NSCs. Considering that mTORC1 is a key switch that suppresses autophagy, we subsequently analyzed the effect of HIF-1 on mTORC1 activity. Our results showed that the mTORC1 activity was negatively regulated by HIF-1. Finally, we provided evidence that HIF-1 regulated mTORC1 activity via its downstream target gene BNIP3. The increased expression of BNIP3 under hypoxia enhanced autophagy activity and proliferation of NSCs, which was mediated by repressing the activity of mTORC1. We further illustrated that BNIP3 can interact with Rheb, a canonical activator of mTORC1. Thus, we suppose that the interaction of BNIP3 with Rheb reduces the regulation of Rheb toward mTORC1 activity, which relieves the suppression of mTORC1 on autophagy, thereby promoting the rapid proliferation of NSCs. Altogether, this study identified a new HIF-1/BNIP3-Rheb/mTORC1 signaling axis, which regulates the NSC proliferation under hypoxia through induction of autophagy.


Asunto(s)
Proteínas de la Membrana , Células-Madre Neurales , Humanos , Proteínas de la Membrana/genética , Hipoxia de la Célula , Hipoxia/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Autofagia , Células-Madre Neurales/metabolismo , Proliferación Celular , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo
19.
Cell Commun Signal ; 22(1): 374, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39054523

RESUMEN

BACKGROUND: High-altitude cerebral edema (HACE) is considered an end-stage acute mountain sickness (AMS) that typically occurs in people after rapid ascent to 2500 m or more. While hypoxia is a fundamental feature of the pathophysiological mechanism of HACE, emerging evidence suggests that inflammation serves as a key risk factor in the occurrence and development of this disease. However, little is known about the molecular mechanism underlying their crosstalk. METHODS: A mouse HACE model was established by combination treatment with hypobaric hypoxia exposure and lipopolysaccharides (LPS) stimulation. Lactylated-proteomic analysis of microglia was performed to reveal the global profile of protein lactylation. Molecular modeling was applied to evaluate the 3-D modeling structures. A combination of experimental approaches, including western blotting, quantitative real-time reverse transcriptionpolymerase chain reaction (qRT-PCR), and enzyme-linked immunosorbent assay (ELISA), confocal microscopy and RNA interference, were used to explore the underlying molecular mechanisms. RESULTS: We found that hypoxia exposure increased the lactate concentration and lactylation in mouse HACE model. Moreover, hypoxia aggravated the microglial neuroinflammatory response in a lactate-dependent manner. Global profiling of protein lactylation has shown that a large quantity of lysine-lactylated proteins are induced by hypoxia and preferentially occur in protein complexes, such as the NuRD complex, ribosome biogenesis complex, spliceosome complex, and DNA replication complex. The molecular modeling data indicated that lactylation could affect the 3-D theoretical structure and increase the solvent accessible surface area of HDAC1, MTA1 and Gatad2b, the core members of the NuRD complex. Further analysis by knockdown or selectively inhibition indicated that the NuRD complex is involved in hypoxia-mediated aggravation of inflammation. CONCLUSIONS: These results revealed a comprehensive profile of protein lactylation in microglia and suggested that protein lysine lactylation plays an important role in the regulation of protein function and subsequently contributes to the neuroinflammatory response under hypoxic conditions.


Asunto(s)
Edema Encefálico , Microglía , Microglía/metabolismo , Microglía/patología , Animales , Edema Encefálico/metabolismo , Edema Encefálico/patología , Ratones , Mal de Altura/metabolismo , Mal de Altura/patología , Masculino , Ratones Endogámicos C57BL , Modelos Animales de Enfermedad , Lipopolisacáridos/farmacología , Altitud , Proteómica
20.
J Cardiovasc Pharmacol ; 83(3): 234-242, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-37944130

RESUMEN

ABSTRACT: Colchicine reduces atherothrombotic cardiovascular events in coronary artery disease because of its anti-inflammatory effect. However, the effects of the other anti-inflammatory drugs in coronary artery disease remain unclear. This study included 132 patients aged 18-80 years who completed the planned percutaneous coronary interventions and were treated with aggressive secondary prevention strategies for 4 weeks. The subjects were randomly assigned to 1 of the following treatment groups for 4 weeks: (1) control: no additional intervention; (2) colchicine: 0.5 mg once a day; (3) tranilast: 0.1 g thrice a day; or (4) oridonin: 0.5 g thrice a day. The primary outcome was the percentage change in high-sensitivity C-reactive protein (hsCRP) levels at the end of 4 weeks. In total, 109 patients completed the study. The mean age was 58.33 years, 81 (74.31%) were male, and 28 (25.69%) were female. The percentage changes in hsCRP after 4 weeks of treatment were -11.62%, -48.28%, -21.60%, and -7.81%, in the control, colchicine, tranilast, and the oridonin groups, respectively. Compared with the control group, only the colchicine group showed significantly greater reduction in hsCRP levels ( P = 0.022). In targeted proteomic analysis, proteins associated with neutrophil activation (azurocidin, myeloperoxidase, and myeloblastin), platelet aggregation (glycoprotein VI), and endothelial damage (galectin-3) were reduced with colchicine therapy. These results show that of 3 anti-inflammatory drugs only colchicine could reduce hsCRP in patients after percutaneous coronary interventions.


Asunto(s)
Enfermedad de la Arteria Coronaria , Diterpenos de Tipo Kaurano , Intervención Coronaria Percutánea , ortoaminobenzoatos , Humanos , Masculino , Femenino , Persona de Mediana Edad , Proteína C-Reactiva/metabolismo , Enfermedad de la Arteria Coronaria/tratamiento farmacológico , Proyectos Piloto , Proteómica , Antiinflamatorios/efectos adversos , Colchicina/efectos adversos , Intervención Coronaria Percutánea/efectos adversos , Resultado del Tratamiento
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