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1.
Plant Cell ; 36(3): 665-687, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-37971931

RESUMEN

Caspases are restricted to animals, while other organisms, including plants, possess metacaspases (MCAs), a more ancient and broader class of structurally related yet biochemically distinct proteases. Our current understanding of plant MCAs is derived from studies in streptophytes, and mostly in Arabidopsis (Arabidopsis thaliana) with 9 MCAs with partially redundant activities. In contrast to streptophytes, most chlorophytes contain only 1 or 2 uncharacterized MCAs, providing an excellent platform for MCA research. Here we investigated CrMCA-II, the single type-II MCA from the model chlorophyte Chlamydomonas (Chlamydomonas reinhardtii). Surprisingly, unlike other studied MCAs and similar to caspases, CrMCA-II dimerizes both in vitro and in vivo. Furthermore, activation of CrMCA-II in vivo correlated with its dimerization. Most of CrMCA-II in the cell was present as a proenzyme (zymogen) attached to the plasma membrane (PM). Deletion of CrMCA-II by genome editing compromised thermotolerance, leading to increased cell death under heat stress. Adding back either wild-type or catalytically dead CrMCA-II restored thermoprotection, suggesting that its proteolytic activity is dispensable for this effect. Finally, we connected the non-proteolytic role of CrMCA-II in thermotolerance to the ability to modulate PM fluidity. Our study reveals an ancient, MCA-dependent thermotolerance mechanism retained by Chlamydomonas and probably lost during the evolution of multicellularity.


Asunto(s)
Arabidopsis , Chlorophyta , Animales , Plantas/metabolismo , Caspasas/genética , Caspasas/química , Caspasas/metabolismo , Arabidopsis/genética , Membrana Celular/metabolismo
2.
Immunity ; 48(3): 530-541.e6, 2018 03 20.
Artículo en Inglés | MEDLINE | ID: mdl-29562201

RESUMEN

Selective expansion of high-affinity antigen-specific B cells in germinal centers (GCs) is a key event in antibody affinity maturation. GC B cells with improved affinity can either continue affinity-driven selection or exit the GC to differentiate into plasma cells (PCs) or memory B cells. Here we found that deleting E3 ubiquitin ligases Cbl and Cbl-b (Cbls) in GC B cells resulted in the early exit of high-affinity antigen-specific B cells from the GC reaction and thus impaired clonal expansion. Cbls were highly expressed in GC light zone (LZ) B cells, where they promoted the ubiquitination and degradation of Irf4, a transcription factor facilitating PC fate choice. Strong CD40 and BCR stimulation triggered the Cbl degradation, resulting in increased Irf4 expression and exit from GC affinity selection. Thus, a regulatory cascade that is centered on the Cbl ubiquitin ligases ensures affinity-driven clonal expansion by connecting BCR affinity signals with differentiation programs.


Asunto(s)
Linfocitos B/inmunología , Linfocitos B/metabolismo , Centro Germinal/inmunología , Centro Germinal/metabolismo , Proteínas Proto-Oncogénicas c-cbl/genética , Proteínas Proto-Oncogénicas c-cbl/metabolismo , Animales , Afinidad de Anticuerpos/ética , Afinidad de Anticuerpos/inmunología , Formación de Anticuerpos/genética , Formación de Anticuerpos/inmunología , Subgrupos de Linfocitos B/inmunología , Subgrupos de Linfocitos B/metabolismo , Diferenciación Celular/genética , Diferenciación Celular/inmunología , Selección Clonal Mediada por Antígenos/genética , Selección Clonal Mediada por Antígenos/inmunología , Expresión Génica , Técnicas de Inactivación de Genes , Factores Reguladores del Interferón/genética , Factores Reguladores del Interferón/metabolismo , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , Ratones , Ratones Transgénicos , Mutación , Unión Proteica , Proteolisis , Receptores de Antígenos de Linfocitos B/genética , Receptores de Antígenos de Linfocitos B/metabolismo , Ubiquitinación
3.
Proc Natl Acad Sci U S A ; 120(43): e2308658120, 2023 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-37844234

RESUMEN

Dysregulated apoptosis and proliferation are fundamental properties of cancer, and microRNAs (miRNA) are critical regulators of these processes. Loss of miR-15a/16-1 at chromosome 13q14 is the most common genomic aberration in chronic lymphocytic leukemia (CLL). Correspondingly, the deletion of either murine miR-15a/16-1 or miR-15b/16-2 locus in mice is linked to B cell lymphoproliferative malignancies. However, unexpectedly, when both miR-15/16 clusters are eliminated, most double knockout (DKO) mice develop acute myeloid leukemia (AML). Moreover, in patients with CLL, significantly reduced expression of miR-15a, miR-15b, and miR-16 associates with progression of myelodysplastic syndrome to AML, as well as blast crisis in chronic myeloid leukemia. Thus, the miR-15/16 clusters have a biological relevance for myeloid neoplasms. Here, we demonstrate that the myeloproliferative phenotype in DKO mice correlates with an increase of hematopoietic stem and progenitor cells (HSPC) early in life. Using single-cell transcriptomic analyses, we presented the molecular underpinning of increased myeloid output in the HSPC of DKO mice with gene signatures suggestive of dysregulated hematopoiesis, metabolic activities, and cell cycle stages. Functionally, we found that multipotent progenitors (MPP) of DKO mice have increased self-renewing capacities and give rise to significantly more progeny in the granulocytic compartment. Moreover, a unique transcriptomic signature of DKO MPP correlates with poor outcome in patients with AML. Together, these data point to a unique regulatory role for miR-15/16 during the early stages of hematopoiesis and to a potentially useful biomarker for the pathogenesis of myeloid neoplasms.


Asunto(s)
Leucemia Linfocítica Crónica de Células B , Leucemia Mieloide Aguda , MicroARNs , Trastornos Mieloproliferativos , Humanos , Animales , Ratones , Leucemia Linfocítica Crónica de Células B/genética , MicroARNs/metabolismo , Células Madre Hematopoyéticas/metabolismo , Leucemia Mieloide Aguda/metabolismo , División Celular , Trastornos Mieloproliferativos/genética
4.
Nat Immunol ; 19(4): 317-318, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29563629
5.
BMC Cancer ; 24(1): 441, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38594604

RESUMEN

BACKGROUND: We recently found that epiplakin 1 (EPPK1) alterations were present in 12% of lung adenocarcinoma (LUAD) cases and were associated with a poor prognosis in early-stage LUAD when combined with other molecular alterations. This study aimed to identify a probable crucial role for EPPK1 in cancer development. METHODS: EPPK1 mRNA and protein expression was analyzed with clinical variables. Normal bronchial epithelial cell lines were exposed to cigarette smoke for 16 weeks to determine whether EPPK1 protein expression was altered after exposure. Further, we used CRISPR-Cas9 to knock out (KO) EPPK1 in LUAD cell lines and observed how the cancer cells were altered functionally and genetically. RESULTS: EPPK1 protein expression was associated with smoking and poor prognosis in early-stage LUAD. Moreover, a consequential mesenchymal-to-epithelial transition was observed, subsequently resulting in diminished cell proliferation and invasion after EPPK1 KO. RNA sequencing revealed that EPPK1 KO induced downregulation of 11 oncogenes, 75 anti-apoptosis, and 22 angiogenesis genes while upregulating 8 tumor suppressors and 12 anti-cell growth genes. We also observed the downregulation of MYC and upregulation of p53 expression at both protein and RNA levels following EPPK1 KO. Gene ontology enrichment analysis of molecular functions highlighted the correlation of EPPK1 with the regulation of mesenchymal cell proliferation, mesenchymal differentiation, angiogenesis, and cell growth after EPPK1 KO. CONCLUSIONS: Our data suggest that EPPK1 is linked to smoking, epithelial to mesenchymal transition, and the regulation of cancer progression, indicating its potential as a therapeutic target for LUAD.


Asunto(s)
Adenocarcinoma del Pulmón , Adenocarcinoma , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/patología , Transición Epitelial-Mesenquimal/genética , Pronóstico , Adenocarcinoma del Pulmón/patología , Adenocarcinoma/patología , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Línea Celular Tumoral
6.
J Org Chem ; 89(4): 2726-2740, 2024 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-38307838

RESUMEN

A facile and efficient approach for the synthesis of multisubstituted tetrahydropyridazines starting from cyclopropyl ketones and hydrazines has been developed. The transformation is chalcone-based and takes place via a Cloke-Wilson-type rearrangement-involved tandem reaction catalyzed by TfOH in HFIP.

7.
Environ Res ; 249: 118236, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38266893

RESUMEN

Excessive noise exposure presents significant health risks to humans, affecting not just the auditory system but also the cardiovascular and central nervous systems. This study focused on three male macaque monkeys as subjects. 90 dB sound pressure level (SPL) pure tone exposure (frequency: 500Hz, repetition rate: 40Hz, 1 min per day, continuously exposed for 5 days) was administered. Assessments were performed before exposure, during exposure, immediately after exposure, and at 7-, 14-, and 28-days post-exposure, employing auditory brainstem response (ABR) tests, electrocardiograms (ECG), and electroencephalograms (EEG). The study found that the average threshold for the Ⅴ wave in the right ear increased by around 30 dB SPL right after exposure (P < 0.01) compared to pre-exposure. This elevation returned to normal within 7 days. The ECG results indicated that one of the macaque monkeys exhibited an RS-type QRS wave, and inverted T waves from immediately after exposure to 14 days, which normalized at 28 days. The other two monkeys showed no significant changes in their ECG parameters. Changes in EEG parameters demonstrated that main brain regions exhibited significant activation at 40Hz during noise exposure. After noise exposure, the power spectral density (PSD) in main brain regions, particularly those represented by the temporal lobe, exhibited a decreasing trend across all frequency bands, with no clear recovery over time. In summary, exposure to 90 dB SPL noise results in impaired auditory systems, aberrant brain functionality, and abnormal electrocardiographic indicators, albeit with individual variations. It has implications for establishing noise protection standards, although the precise mechanisms require further exploration by integrating pathological and behavioral indicators.


Asunto(s)
Electrocardiografía , Electroencefalografía , Potenciales Evocados Auditivos del Tronco Encefálico , Ruido , Animales , Masculino , Ruido/efectos adversos , Macaca/fisiología
8.
Proc Natl Acad Sci U S A ; 118(30)2021 07 27.
Artículo en Inglés | MEDLINE | ID: mdl-34301867

RESUMEN

Antibody affinity maturation occurs in the germinal center (GC), a highly dynamic structure that arises upon antigen stimulation and recedes after infection is resolved. While the magnitude of the GC reaction is highly fluctuating and depends on antigens or pathological conditions, it is unclear whether GCs are assembled ad hoc in different locations or in preexisting niches within B cell follicles. We show that follicular dendritic cells (FDCs), the essential cellular components of the GC architecture, form a predetermined number of clusters. The total number of FDC clusters is the same on several different genetic backgrounds and is not altered by immunization or inflammatory conditions. In unimmunized and germ-free mice, a few FDC clusters contain GC B cells; in contrast, immunization or autoimmune milieu significantly increases the frequency of FDC clusters occupied by GC B cells. Excessive occupancy of GC niches by GC B cells after repeated immunizations or in autoimmune conditions suppresses subsequent antibody responses to new antigens. These data indicate that the magnitude of the GC reaction is restricted by a fixed number of permissive GC niches containing preassembled FDC clusters. This finding may help in the future design of vaccination strategies and in the modulation of antibody-mediated autoimmunity.


Asunto(s)
Formación de Anticuerpos , Antígenos/inmunología , Linfocitos B/inmunología , Diferenciación Celular , Células Dendríticas Foliculares/inmunología , Centro Germinal/inmunología , Animales , Afinidad de Anticuerpos , Femenino , Inmunización , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL
9.
Hum Brain Mapp ; 44(2): 341-361, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36647263

RESUMEN

Emerging evidence indicates that activity flow over resting-state network topology allows the prediction of task activations. However, previous studies have mainly adopted static, linear functional connectivity (FC) estimates as activity flow routes. It is unclear whether an intrinsic network topology that captures the dynamic nature of FC can be a better representation of activity flow routes. Moreover, the effects of between- versus within-network connections and tight versus loose (using rest baseline) task contrasts on the prediction of task-evoked activity across brain systems remain largely unknown. In this study, we first propose a probabilistic FC estimation derived from a dynamic framework as a new activity flow route. Subsequently, activity flow mapping was tested using between- and within-network connections separately for each region as well as using a set of tight task contrasts. Our results showed that probabilistic FC routes substantially improved individual-level activity flow prediction. Although it provided better group-level prediction, the multiple regression approach was more dependent on the length of data points at the individual-level prediction. Regardless of FC type, we consistently observed that between-network connections showed a relatively higher prediction performance in higher-order cognitive control than in primary sensorimotor systems. Furthermore, cognitive control systems exhibit a remarkable increase in prediction accuracy with tight task contrasts and a decrease in sensorimotor systems. This work demonstrates that probabilistic FC estimates are promising routes for activity flow mapping and also uncovers divergent influences of connectional topology and task contrasts on activity flow prediction across brain systems with different functional hierarchies.


Asunto(s)
Mapeo Encefálico , Imagen por Resonancia Magnética , Humanos , Mapeo Encefálico/métodos , Imagen por Resonancia Magnética/métodos , Vías Nerviosas/fisiología , Encéfalo/diagnóstico por imagen , Encéfalo/fisiología , Descanso/fisiología
10.
Biochem Biophys Res Commun ; 658: 97-106, 2023 05 28.
Artículo en Inglés | MEDLINE | ID: mdl-37030070

RESUMEN

BACKGROUND: Evidence shows that microwaves radiation may have various biological effects on central nervous system. Role of electromagnetic fields in neurodegenerative diseases, especially AD, has been widely studied, but results of these studies are inconsistent. Therefore, the above effects were verified again and the mechanism was preliminarily discussed. METHODS: Amyloid precursor protein (APP/PS1) and WT mice were exposed to long-term microwave radiation for 270 days (900 MHz, SAR: 0.25-1.055 W/kg, 2 h/day, alternately), and related indices were assessed at 90, 180 and 270 days. Cognition was evaluated by Morris water maze, Y maze and new object recognition tests. Congo red staining, immunohistochemistry and ELISA were used to analyze Aß plaques, Aß40 and Aß42 content. Differentially expressed proteins in hippocampus between microwave-exposed and unexposed AD mice were identified by proteomics. RESULTS: Spatial and working memory was improved in AD mice after long-term 900 MHz microwave exposure compared with after sham exposure. Microwave radiation (900 MHz) for 180 or 270 days did not induce Aß plaque formation in WT mice but inhibited Aß accumulation in the cerebral cortex and hippocampus in 2- and 5-month-old APP/PS1 mice. This effect mainly occurred in the late stage of the disease and may have been attributed to downregulation of apolipoprotein family member and SNCA expression and excitatory/inhibitory neurotransmitter rebalance in the hippocampus. CONCLUSIONS: The present results indicated that long-term microwave radiation can retard AD development and exert a beneficial effect against AD, suggesting that 900 MHz microwave exposure may be a potential therapy for AD.


Asunto(s)
Enfermedad de Alzheimer , Ratones , Animales , Enfermedad de Alzheimer/terapia , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/metabolismo , Ratones Transgénicos , Campos Electromagnéticos , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Hipocampo/metabolismo , Modelos Animales de Enfermedad , Presenilina-1/genética , Presenilina-1/metabolismo
11.
Toxicol Appl Pharmacol ; 474: 116629, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37468076

RESUMEN

Thiacloprid (THIA) is a kind of neonicotinoid, a widely used insecticide class. Animal studies of adult and prenatal exposure to THIA have revealed deleterious effects on mammalian sperm fertility and embryonic development. A recent cross-sectional study linked higher THIA concentrations to delayed genitalia development stages in adolescent boys, suggesting that pubertal exposure to THIA may adversely affect reproductive development in immature males. Hence, this study aimed to investigate the effects of daily oral administration of THIA during puberty on the reproductive system of developing male mice. Young male C57 BL/6 J mice aged 21 days were administrated with THIA at concentrations of 10 (THIA-10), 50 (THIA-50) and 100 mg/kg (THIA-100) for 4 weeks by oral gavage. It is found that exposure to 100 mg/kg THIA diminished sexual behavior in immature male mice, caused a decrease in the spermatogenic cell layers and irregular arrangement of the seminiferous epithelium, and down-regulated the mRNA levels of spermatogenesis-related genes Ddx4, Scp3, Atg5, Crem, and Ki67, leading to an increase of sperm abnormality rate. In addition, THIA exposure at 50 and 100 mg/kg reduced the serum levels of testosterone and FSH, and decreased the expression levels of Star and Cyp11a1 related to testosterone biosynthesis. THIA exposure at 10 mg/kg did not produce any of the above significant changes. In conclusion, the high dose of THIA exposure impaired reproductive function in immature mice. It seems that THIA has no detrimental effects on the reproductive system of mice at low dose of 10 mg/kg.


Asunto(s)
Efectos Tardíos de la Exposición Prenatal , Testículo , Embarazo , Femenino , Ratones , Masculino , Animales , Humanos , Semen , Espermatogénesis , Testosterona , Neonicotinoides/metabolismo , Efectos Tardíos de la Exposición Prenatal/metabolismo , Mamíferos
12.
Acta Pharmacol Sin ; 44(3): 546-560, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36042291

RESUMEN

Sirtuin3 (SIRT3), a class III histone deacetylase, is implicated in various cardiovascular diseases as a novel therapeutic target. SIRT3 has been proven to be cardioprotective in a model of Ang II-induced cardiac hypertrophy. However, a few small-molecule compounds targeting deacetylases could activate SIRT3. In this study, we generated a novel SIRT3 activator, 3-(2-bromo-4-hydroxyphenyl)-7-hydroxy-2H-chromen-2-one (SZC-6), through structural optimization of the first SIRT3 agonist C12. We demonstrated that SZC-6 directly bound to SIRT3 with Kd value of 15 µM, and increased SIRT3 deacetylation activity with EC50 value of 23.2 ± 3.3 µM. In neonatal rat cardiomyocytes (NRCMs), pretreatment with SZC-6 (10, 20, 40 µM) dose-dependently attenuated isoproterenol (ISO)-induced hypertrophic responses. Administration of SZC-6 (20, 40 and 60 mg·kg-1·d-1, s.c.) for 2 weeks starting from one week prior ISO treatment dose-dependently reversed ISO-induced impairment of diastolic and systolic cardiac function in wild-type mice, but not in SIRT3 knockdown mice. We showed that SZC-6 (10, 20, 40 µM) dose-dependently inhibited cardiac fibroblast proliferation and differentiation into myofibroblasts, which was abolished in SIRT3-knockdown mice. We further revealed that activation of SIRT3 by SZC-6 increased ATP production and rate of mitochondrial oxygen consumption, and reduced ROS, improving mitochondrial function in ISO-treated NRCMs. We also found that SZC-6 dose-dependently enhanced LKB1 phosphorylation, thereby promoting AMPK activation to inhibit Drp1-dependent mitochondrial fragmentation. Taken together, these results demonstrate that SZC-6 is a novel SIRT3 agonist with potential value in the treatment of cardiac hypertrophy partly through activation of the LKB1-AMPK pathway.


Asunto(s)
Sirtuina 3 , Ratones , Ratas , Animales , Sirtuina 3/metabolismo , Proteínas Quinasas Activadas por AMP/metabolismo , Cardiomegalia/inducido químicamente , Miocitos Cardíacos/metabolismo , Isoproterenol
13.
Heart Vessels ; 38(6): 857-868, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36717388

RESUMEN

Chronic heart failure (CHF), a conventional, complex, and severe syndrome, is generally defined by myocardial output inadequate to satisfy the metabolic requirements of body tissues. Recently, miR-568 was identified to be down-regulated in CHF patients' sera and negatively correlated with left ventricular mass index in symptomatic CHF patients with systolic dysfunction. Nevertheless, the role of miR-568 during CHF development remains obscure. The current study is aimed to investigate the role of miR-568 in CHF. The MTT assay, flow cytometry analysis, RT-qPCR analysis, western blot analysis and luciferase reporter assays were conducted to figure out the function and potential mechanism of miR-568 in vitro. Rats were operated with aortic coarctation to establish CHF animal model. The effects of miR-568 and SMURF2 on CHF rats were evaluated by hematoxylin-eosin staining, Masson's staining, serum index testing, cardiac ultrasound detection, and TUNEL staining assays. We discovered that miR-568 level was downregulated by H2O2 treatment in cardiomyocytes. In mechanism, miR-568 directly targeted and negatively regulated SMURF2. In function, SMURF2 overexpression reversed the effects of miR-568 on cardiac function and histological changes in vivo. Additionally, SMURF2 overexpression reversed the effects of miR-568 on the content of LDH, AST, CK and CK-MB in vivo. Moreover, SMURF2 overexpression reversed the effects of miR-568 on oxidative stress response in vivo. MiR-568 mitigated cardiomyocytes apoptosis, oxidative stress response and cardiac dysfunction via targeting SMURF2 in CHF rats. This discovery may serve as a potential biomarker for CHF treatment.


Asunto(s)
Insuficiencia Cardíaca , MicroARNs , Ratas , Animales , Miocitos Cardíacos/metabolismo , Peróxido de Hidrógeno/metabolismo , Peróxido de Hidrógeno/farmacología , MicroARNs/genética , MicroARNs/metabolismo , Insuficiencia Cardíaca/metabolismo , Apoptosis , Estrés Oxidativo , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Ubiquitina-Proteína Ligasas/farmacología
14.
J Trop Pediatr ; 69(5)2023 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-37674390

RESUMEN

Coronavirus disease 2019 (COVID-19) has become a significant global public health problem. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which causes the disease, utilizes angiotensin-converting enzyme II (ACE2) as a major functional receptor to enter host cells. No study has systematically assessed ACE2 expression in multiple tissues in children. This study investigated ACE2 expression and ACE2 protein's histological distribution in various organs in paediatric patients (the small intestine, thymus, heart and lungs). Our study revealed that ACE2 was highly expressed in enterocytes of the small intestine and widely expressed in the myocardium of heart tissues. The most notable finding was the positive staining of ACE2 in the Hassall's corpuscles epithelial cells. Negligible ACE2 expression in the lung tissues may contribute to a lower risk of infection and fewer symptoms of pneumonia in children than in adults with COVID-19 infection. These findings provide initial evidence for understanding SARS-CoV-2 pathogenesis and prevention strategies in paediatric clinical practice, which should be applicable for all children worldwide.


Asunto(s)
COVID-19 , SARS-CoV-2 , Adulto , Humanos , Niño , Enzima Convertidora de Angiotensina 2/genética , Corazón , Salud Pública
15.
Sensors (Basel) ; 23(9)2023 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-37177545

RESUMEN

As the number and length of high-speed railway tunnels increase in China, implicit defects such as insufficient lining thicknesses, voids, and poor compaction have become increasingly common, posing a serious threat to train operation safety. It is, therefore, imperative to conduct a comprehensive census of the defects within the tunnel linings. In response to this problem, this study proposes a high-speed railway tunnel detection method based on vehicle-mounted air-coupled GPR. Building on a forward simulation of air-coupled GPR, the study proposes the F-K filtering and BP migration algorithms based on the practical considerations of random noise and imaging interference from the inherent equipment. Through multi-dimensional quantitative comparisons, these algorithms are shown to improve the spectrum entropy values and instantaneous amplitude ratios by 4.6% and 11.6%; and 120% and 180%, respectively, over the mean and bandpass filtering algorithms, demonstrating their ability to suppress clutter and enhance the internal signal prominence of the lining. The experimental results are consistent with the forward simulation trends, and the verification using the ground-coupled GPR detection confirms that air-coupled GPR can meet the requirements of high-speed railway tunnel lining inspections. A comprehensive GPR detection model is proposed to lay the foundation for a subsequent defect census of high-speed railway tunnels.

16.
Int J Mol Sci ; 24(4)2023 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-36835251

RESUMEN

Alzheimer's disease (AD) is the most frequent cause of cognitive impairment in middle-aged and older populations. There is a lack of drugs that demonstrate significant efficacy in AD, so the study of the pathogenesis of AD is of great importance. More efficacious interventions are needed, as reflected by our population's fast aging. Synaptic plasticity is the capacity of neurons to adjust their connections, and it is strongly tied to learning and memory, cognitive function, and brain injury recovery. Changes in synaptic strength, such as long-term potentiation (LTP) or inhibition (LTD), are thought to represent the biological foundation of the early stages of learning and memory. The results of numerous studies confirm that neurotransmitters and their receptors play an important role in the regulation of synaptic plasticity. However, so far, there is no definite correlation between the function of neurotransmitters in aberrant neural oscillation and AD-related cognitive impairment. We summarized the AD process to understand the impact of neurotransmitters in the progression and pathogenesis of AD, including the current status of neurotransmitter target drugs, and the latest evidence of neurotransmitters' function and changes in the AD process.


Asunto(s)
Enfermedad de Alzheimer , Persona de Mediana Edad , Humanos , Anciano , Animales , Enfermedad de Alzheimer/patología , Plasticidad Neuronal , Potenciación a Largo Plazo , Aprendizaje , Neurotransmisores/farmacología , Modelos Animales de Enfermedad , Hipocampo
17.
J Comput Sci Technol ; 38(1): 25-63, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37016602

RESUMEN

With the increasing pervasiveness of mobile devices such as smartphones, smart TVs, and wearables, smart sensing, transforming the physical world into digital information based on various sensing medias, has drawn researchers' great attention. Among different sensing medias, WiFi and acoustic signals stand out due to their ubiquity and zero hardware cost. Based on different basic principles, researchers have proposed different technologies for sensing applications with WiFi and acoustic signals covering human activity recognition, motion tracking, indoor localization, health monitoring, and the like. To enable readers to get a comprehensive understanding of ubiquitous wireless sensing, we conduct a survey of existing work to introduce their underlying principles, proposed technologies, and practical applications. Besides we also discuss some open issues of this research area. Our survey reals that as a promising research direction, WiFi and acoustic sensing technologies can bring about fancy applications, but still have limitations in hardware restriction, robustness, and applicability. Supplementary Information: The online version contains supplementary material available at 10.1007/s11390-023-3073-5.

18.
Angew Chem Int Ed Engl ; 62(37): e202305661, 2023 Sep 11.
Artículo en Inglés | MEDLINE | ID: mdl-37479952

RESUMEN

The low-temperature reverse water-gas shift (RWGS) reaction faces the following obstacles: low activity and unsatisfactory selectivity. Herein, the dual-active sites of platinum (Pt) clusters and frustrated Lewis pair (FLP) on porous CeO2 nanorods (Ptcluster /PN-CeO2 ) provide an interface-independent pathway to boost high performance RWGS reaction at low temperatures. Mechanistic investigations illustrate that Pt clusters can effectively activate and dissociate H2 . The FLP sites, instead of the metal and support interfaces, not only enhance the strong adsorption and activation of CO2 , but also significantly weaken CO adsorption on FLP to facilitate CO release and suppress the CH4 formation. With the help of hydrogen spillover from Pt to PN-CeO2 , the Ptcluster /PN-CeO2 catalysts achieved a CO yield of 29.6 %, which is very close to the thermodynamic equilibrium yield of CO (29.8 %) at 350 °C. Meanwhile, the Ptcluster /PN-CeO2 catalysts delivered a large turnover frequency of 8720 h-1 . Moreover, Ptcluster /PN-CeO2 operated stably and continuously for at least 840 h. This finding provides a promising path toward optimizing the RWGS reaction.

19.
Dev Biol ; 477: 70-84, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34015362

RESUMEN

The C-X-C chemokine receptor CXCR4 and its ligand CXCL12 play an important role in organ-specific vascular branching morphogenesis. CXCR4 is preferentially expressed by arterial endothelial cells, and local secretion of CXCL12 determines the organotypic pattern of CXCR4+ arterial branching. Previous loss-of-function studies clearly demonstrated that CXCL12-CXCR4 signaling is necessary for proper arterial branching in the developing organs such as the skin and heart. To further understand the role of CXCL12-CXCR4 signaling in organ-specific vascular development, we generated a mouse model carrying the Cre recombinase-inducible Cxcr4 transgene. Endothelial cell-specific Cxcr4 gain-of-function embryos exhibited defective vascular remodeling and formation of a hierarchical vascular branching network in the developing skin and heart. Ectopic expression of CXCR4 in venous endothelial cells, but not in lymphatic endothelial cells, caused blood-filled, enlarged lymphatic vascular phenotypes, accompanied by edema. These data suggest that CXCR4 expression is tightly regulated in endothelial cells for appropriate vascular development in an organ-specific manner.


Asunto(s)
Vasos Sanguíneos/embriología , Células Endoteliales/fisiología , Neovascularización Fisiológica/fisiología , Receptores CXCR4/fisiología , Animales , Vasos Sanguíneos/anatomía & histología , Células Endoteliales/metabolismo , Mutación con Ganancia de Función , Células HEK293 , Humanos , Ratones , Ratones Endogámicos C57BL , Receptores CXCR4/biosíntesis , Remodelación Vascular/fisiología
20.
Int J Obes (Lond) ; 46(11): 1970-1982, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35922561

RESUMEN

BACKGROUND: FAM132b (myonectin) has been identified as a muscle-derived myokine with exercise and has hormone activity in circulation to regulate iron homeostasis and lipid metabolism via unknown receptors. Here, we aim to explore the potential of adeno-associated virus to deliver FAM132b in vivo to develop a gene therapy against obesity. METHODS: Adeno-associated virus AAV9 were engineered to induce overexpression of FAM132b with two mutations, A136T and P159A. Then, AAV9 was delivered into high-fat diet mice through tail vein, and glucose homeostasis and obesity development of mice were observed. Methods of structural biology were used to predict the action site or receptor of the FAM132b mutant. RESULTS: Treatment of high-fat diet-fed mice with AAV9 improved glucose intolerance and insulin resistance, and resulted in reductions in body weight, fat depot, and adipocyte size. Codon-optimized FAM132b (coFAM132b) reduced the glycemic response to epinephrine (EPI) in the whole body and increased the lipolytic response to EPI in adipose tissues. However, FAM132b knockdown by shRNA significantly increased the glycemic response to EPI in vivo and reduced adipocyte response to EPI and adipose tissue browning. Structural analysis predicted that the FAM132b mutant with A136T and P159A may form a weak bond with ß2 adrenergic receptor (ADRB2) and may have more affinity for insulin and insulin-receptor complexes. CONCLUSIONS: Our study underscores the potential of FAM132b gene therapy with codon optimization to treat obesity by modulating the adrenergic response and insulin action. Both structural biological analysis and in vivo experiments suggest that the adrenergic response and insulin action are most likely blockaded by FAM132b mutants.


Asunto(s)
Adrenérgicos , Resistencia a la Insulina , Ratones , Animales , ARN Interferente Pequeño , Obesidad/genética , Obesidad/terapia , Obesidad/metabolismo , Resistencia a la Insulina/genética , Dieta Alta en Grasa , Insulina/metabolismo , Glucemia/metabolismo , Terapia Genética , Codón , Epinefrina , Receptores Adrenérgicos/genética , Hierro , Ratones Endogámicos C57BL
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