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1.
Nature ; 623(7987): 580-587, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37938769

RESUMO

Microsatellite repeat expansions within genes contribute to a number of neurological diseases1,2. The accumulation of toxic proteins and RNA molecules with repetitive sequences, and/or sequestration of RNA-binding proteins by RNA molecules containing expanded repeats are thought to be important contributors to disease aetiology3-9. Here we reveal that the adenosine in CAG repeat RNA can be methylated to N1-methyladenosine (m1A) by TRMT61A, and that m1A can be demethylated by ALKBH3. We also observed that the m1A/adenosine ratio in CAG repeat RNA increases with repeat length, which is attributed to diminished expression of ALKBH3 elicited by the repeat RNA. Additionally, TDP-43 binds directly and strongly with m1A in RNA, which stimulates the cytoplasmic mis-localization and formation of gel-like aggregates of TDP-43, resembling the observations made for the protein in neurological diseases. Moreover, m1A in CAG repeat RNA contributes to CAG repeat expansion-induced neurodegeneration in Caenorhabditis elegans and Drosophila. In sum, our study offers a new paradigm of the mechanism through which nucleotide repeat expansion contributes to neurological diseases and reveals a novel pathological function of m1A in RNA. These findings may provide an important mechanistic basis for therapeutic intervention in neurodegenerative diseases emanating from CAG repeat expansion.


Assuntos
Adenosina , Caenorhabditis elegans , Proteínas de Ligação a DNA , Drosophila melanogaster , Doenças Neurodegenerativas , RNA , Expansão das Repetições de Trinucleotídeos , Animais , Humanos , Adenosina/análogos & derivados , Adenosina/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Ligação a DNA/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , RNA/química , RNA/genética , RNA/metabolismo , Expansão das Repetições de Trinucleotídeos/genética , Citoplasma/metabolismo , Modelos Animais de Doenças
2.
Mol Cell ; 81(3): 546-557.e5, 2021 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-33378643

RESUMO

Eukaryotic cells regulate 5'-triphosphorylated RNAs (ppp-RNAs) to promote cellular functions and prevent recognition by antiviral RNA sensors. For example, RNA capping enzymes possess triphosphatase domains that remove the γ phosphates of ppp-RNAs during RNA capping. Members of the closely related PIR-1 (phosphatase that interacts with RNA and ribonucleoprotein particle 1) family of RNA polyphosphatases remove both the ß and γ phosphates from ppp-RNAs. Here, we show that C. elegans PIR-1 dephosphorylates ppp-RNAs made by cellular RNA-dependent RNA polymerases (RdRPs) and is required for the maturation of 26G-RNAs, Dicer-dependent small RNAs that regulate thousands of genes during spermatogenesis and embryogenesis. PIR-1 also regulates the CSR-1 22G-RNA pathway and has critical functions in both somatic and germline development. Our findings suggest that PIR-1 modulates both Dicer-dependent and Dicer-independent Argonaute pathways and provide insight into how cells and viruses use a conserved RNA phosphatase to regulate and respond to ppp-RNA species.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/enzimologia , Monoéster Fosfórico Hidrolases/metabolismo , Processamento Pós-Transcricional do RNA , RNA/metabolismo , Animais , Animais Geneticamente Modificados , Caenorhabditis elegans/embriologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Regulação da Expressão Gênica no Desenvolvimento , Monoéster Fosfórico Hidrolases/genética , Fosforilação , RNA/genética , Capuzes de RNA , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , Ribonuclease III/genética , Ribonuclease III/metabolismo , Espermatogênese , Especificidade por Substrato
3.
FASEB J ; 38(1): e23381, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38102952

RESUMO

Dysfunction of the human voltage-gated K+ channel Kv1.1 has been associated with epilepsy, multiple sclerosis, episodic ataxia, myokymia, and cardiorespiratory dysregulation. We report here that AETX-K, a sea anemone type I (SAK1) peptide toxin we isolated from a phage display library, blocks Kv1.1 with high affinity (Ki ~ 1.6 pM) and notable specificity, inhibiting other Kv channels we tested a million-fold less well. Nuclear magnetic resonance (NMR) was employed both to determine the three-dimensional structure of AETX-K, showing it to employ a classic SAK1 scaffold while exhibiting a unique electrostatic potential surface, and to visualize AETX-K bound to the Kv1.1 pore domain embedded in lipoprotein nanodiscs. Study of Kv1.1 in Xenopus oocytes with AETX-K and point variants using electrophysiology demonstrated the blocking mechanism to employ a toxin-channel configuration we have described before whereby AETX-K Lys23 , two positions away on the toxin interaction surface from the classical blocking residue, enters the pore deeply enough to interact with K+ ions traversing the pathway from the opposite side of the membrane. The mutant channel Kv1.1-L296 F is associated with pharmaco-resistant multifocal epilepsy in infants because it significantly increases K+ currents by facilitating opening and slowing closure of the channels. Consistent with the therapeutic potential of AETX-K for Kv1.1 gain-of-function-associated diseases, AETX-K at 4 pM decreased Kv1.1-L296 F currents to wild-type levels; further, populations of heteromeric channels formed by co-expression Kv1.1 and Kv1.2, as found in many neurons, showed a Ki of ~10 nM even though homomeric Kv1.2 channels were insensitive to the toxin (Ki > 2000 nM).


Assuntos
Epilepsia , Mutação com Ganho de Função , Humanos , Peptídeos/genética , Peptídeos/farmacologia , Epilepsia/genética , Bloqueadores dos Canais de Potássio/farmacologia
5.
Proc Natl Acad Sci U S A ; 119(23): e2120750119, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35648818

RESUMO

The human voltage-gated proton channel (hHv1) is important for control of intracellular pH. We designed C6, a specific peptide inhibitor of hHv1, to evaluate the roles of the channel in sperm capacitation and in the inflammatory immune response of neutrophils [R. Zhao et al., Proc. Natl. Acad. Sci. U.S.A. 115, E11847­E11856 (2018)]. One C6 binds with nanomolar affinity to each of the two S3­S4 voltage-sensor loops in hHv1 in cooperative fashion so that C6-bound channels require greater depolarization to open and do so more slowly. As depolarization drives hHv1 sensors outwardly, C6 affinity decreases, and inhibition is partial. Here, we identified residues essential to C6­hHv1 binding by scanning mutagenesis, five in the hHv1 S3­S4 loops and seven on C6. A structural model of the C6­hHv1 complex was then generated by molecular dynamics simulations and validated by mutant-cycle analysis. Guided by this model, we created a bivalent C6 peptide (C62) that binds simultaneously to both hHv1 subunits and fully inhibits current with picomolar affinity. The results help delineate the structural basis for C6 state-dependent inhibition, support an anionic lipid-mediated binding mechanism, and offer molecular insight into the effectiveness of engineered C6 as a therapeutic agent or lead.


Assuntos
Desenho de Fármacos , Canais Iônicos , Humanos , Canais Iônicos/antagonistas & inibidores , Canais Iônicos/química , Canais Iônicos/genética , Masculino , Mutagênese , Peptídeos/química , Peptídeos/farmacologia , Ligação Proteica , Prótons , Capacitação Espermática
6.
J Cell Biochem ; 125(5): e30551, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38465779

RESUMO

Neuregulin-4 (Nrg4) and melatonin play vital roles in endocrine diseases. However, there is little discussion about the function and potential mechanism of Nrg4 and melatonin in prolactin (PRL) regulation. The human normal pituitary data from Gene Expression Profiling Interactive Analysis (GEPIA) database was used to explore the correlation between NRG4 and PRL. The expression and correlation of NRG4 and PRL were determined by Immunofluorescence staining (IF) and human normal pituitary tissue microarray. Western Blot (WB) was used to detect the expression of PRL, p-ErbB2/3/4, ErbB2/3/4, p-Erk1/2, Erk1/2, p-Akt and Akt in PRL-secreting pituitary GH3 and RC-4B/C cells treated by Nrg4, Nrg4-small interfering RNA, Erk1/2 inhibitor FR180204 and melatonin. The expression of NRG4 was significantly positively correlated with that of PRL in the GEPIA database and normal human pituitary tissues. Nrg4 significantly increased the expression and secretion of PRL and p-Erk1/2 expression in GH3 cells and RC-4B/C cells. Inhibition of Nrg4 significantly inhibited PRL expression. The increased levels of p-Erk1/2 and PRL induced by Nrg4 were abolished significantly in response to FR180204 in GH3 and RC-4B/C cells. Additionally, Melatonin promotes the expression of Nrg4, p-ErbB4, p-Erk1/2, and PRL and can further promote the expression of p-Erk1/2 and PRL in combination with Nrg4. Further investigation into the function of Nrg4 and melatonin on PRL expression and secretion may provide new clues to advance the clinical control of prolactinomas and hyperprolactinemia.


Assuntos
Sistema de Sinalização das MAP Quinases , Melatonina , Neurregulinas , Prolactina , Receptor ErbB-4 , Melatonina/farmacologia , Humanos , Prolactina/metabolismo , Receptor ErbB-4/metabolismo , Receptor ErbB-4/genética , Neurregulinas/metabolismo , Neurregulinas/genética , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Hipófise/metabolismo , Hipófise/citologia , Animais , Ratos
7.
Anal Chem ; 96(4): 1789-1794, 2024 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-38230634

RESUMO

Highly sensitive and facile detection of low levels of protein markers is of great significance for the early diagnosis and efficacy monitoring of diseases. Herein, aided by an efficient tyramine-signal amplification (TSA) mechanism, we wish to report a simple but ultrasensitive immunoassay with signal readout on a portable personal glucose meter (PGM). In this study, the bioconjugates of tyramine and invertase (Tyr-inv), which act as the critical bridge to convert and amplify the protein concentration information into glucose, are prepared following a click chemistry reaction. Then, in the presence of a target protein, the sandwich immunoreaction between the immobilized capture antibody, the target protein, and the horseradish peroxidase (HRP)-conjugated detection antibody is specifically performed in a 96-well microplate. Subsequently, the specifically loaded HRP-conjugated detection antibodies will catalyze the amplified deposition of a large number of Tyr-inv molecules onto adjacent proteins through highly efficient TSA. Then, the deposited invertase, whose dosage can faithfully reflect the original concentration of the target protein, can efficiently convert sucrose to glucose. The amount of finally produced glucose is simply quantified by the PGM, realizing the highly sensitive detection of trace protein markers such as the carcinoembryonic antigen and alpha fetoprotein antigen at the fg/mL level. This method is simple, cost-effective, and ultrasensitive without the requirement of sophisticated instruments or specialized laboratory equipment, which may provide a universal and promising technology for highly sensitive immunoassay for in vitro diagnosis of diseases.


Assuntos
Técnicas Biossensoriais , Glucose , beta-Frutofuranosidase/química , Técnicas Biossensoriais/métodos , Imunoensaio/métodos , Anticorpos , Peroxidase do Rábano Silvestre/química , Tiramina/química , Ouro/química
8.
Mod Pathol ; 37(1): 100371, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38015043

RESUMO

B7-H4 (VTCN1), a member of the B7 family, is overexpressed in several types of cancer. Here we investigated the pattern of expression of B7-H4 in salivary gland carcinomas (SGC) and assessed its potential as a prognostic marker and therapeutic target. Immunohistochemistry (IHC) analyses were performed in a cohort of 340 patient tumors, composed of 124 adenoid cystic carcinomas (ACC), 107 salivary duct carcinomas (SDC), 64 acinic cell carcinomas, 36 mucoepidermoid carcinomas (MEC), 9 secretory carcinomas (SC), as well as 20 normal salivary glands (controls). B7-H4 expression was scored and categorized into negative (<5% expression of any intensity), low (5%-70% expression of any intensity or >70% with weak intensity), or high (>70% moderate or strong diffuse intensity). The associations between B7-H4 expression and clinicopathologic characteristics, as well as overall survival, were assessed. Among all tumors, B7-H4 expression was more prevalent in ACC (94%) compared with those of SC (67%), MEC (44%), SDC (32%), and acinic cell carcinomas (0%). Normal salivary gland tissue did not express B7-H4. High expression of B7-H4 was found exclusively in ACC (27%), SDC (11%), and MEC (8%). In SDC, B7-H4 expression was associated with female gender (P = .002) and lack of androgen receptor expression (P = .012). In ACC, B7-H4 expression was significantly associated with solid histology (P < .0001) and minor salivary gland primary (P = .02). High B7-H4 expression was associated with a poorer prognosis in ACC, regardless of clinical stage and histologic subtype. B7-H4 expression was not prognostic in the non-ACC SGC evaluated. Our comparative study revealed distinct patterns of B7-H4 expression according to SGC histology, which has potential therapeutic implications. B7-H4 expression was particularly high in solid ACC and was an independent prognostic marker in this disease but not in the other SGC assessed.


Assuntos
Neoplasias da Mama , Carcinoma de Células Acinares , Carcinoma Adenoide Cístico , Carcinoma Mucoepidermoide , Carcinoma , Neoplasias das Glândulas Salivares , Humanos , Feminino , Carcinoma Adenoide Cístico/patologia , Prognóstico , Carcinoma de Células Acinares/patologia , Neoplasias das Glândulas Salivares/patologia , Carcinoma Mucoepidermoide/patologia , Carcinoma/patologia , Glândulas Salivares/química , Glândulas Salivares/metabolismo , Glândulas Salivares/patologia , Biomarcadores Tumorais/análise
9.
Ann Surg Oncol ; 31(4): 2777-2785, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38334846

RESUMO

BACKGROUND: Minimal access breast surgery improves cosmetic outcomes over conventional breast surgery but still faces barriers in becoming standard procedure for breast reconstruction. This report introduces a novel technique of transaxillary reverse-sequence endoscopic nipple-sparing mastectomy (R-E-NSM) followed by direct-to-implant prepectoral breast reconstruction (DTI-PBR) and describes its clinical outcomes. METHODS: This prospective study enrolled patients who underwent R-E-NSM and DTI-PBR from March 2021 to December 2021 at a single institution. Perioperative data, surgical complications, oncologic outcomes, and patient- and surgeon-reported cosmetic results were noted. RESULTS: The 60 patients in this study who underwent 68 R-E-NSM and DTI-PBR had a mean age was 40.4 ± 10.3 years. The average durations of uni- and bilateral operations were 156.5 ± 48.3 min and 191.3 ± 36.1 min, respectively. The overall surgical complication rate was 13.3%, including 10.0% of patients with minor complications and 3.3% of patients with major complications. The study had one case (1.7%) of implant loss and one case (1.7%) of skin flap necrosis treated by reoperation. During the median follow-up period of 24 months, one patient (1.7%) who discontinued chemotherapy for myelosuppression experienced liver metastases 5 months postoperatively, and one patient experienced new-onset contralateral ductal carcinoma in situ 24 months postoperatively. The preoperative and 18-month postoperative Breast-Q scores for satisfaction with breasts, psychosocial well-being, sexual well-being, and chest well-being did not differ significantly, and the Scar-Q was 81.2 ± 14.5 points. The good-to-excellent rate in surgeon-reported cosmetic results reached 90%. CONCLUSIONS: Transaxillary R-E-NSM followed by DTI-PBR is a safe and efficient technique with high cosmetic outcomes and reliable medium-term oncologic results.


Assuntos
Implantes de Mama , Neoplasias da Mama , Mamoplastia , Humanos , Adulto , Pessoa de Meia-Idade , Feminino , Mastectomia/métodos , Estudos Prospectivos , Mamilos/cirurgia , Neoplasias da Mama/cirurgia , Mamoplastia/métodos , Estudos Retrospectivos
10.
BMC Cancer ; 24(1): 6, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166698

RESUMO

BACKGROUND: Anlotinib is a multi-target tyrosine kinase inhibitor (TKI) targeting the vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), fibroblast growth factor receptor (FGFR), and c-Kit. This phase II study aimed to assess the efficacy and safety of anlotinib, either alone or in combination with bevacizumab (Bev) for recurrent high-grade glioma (rHGG) (NCT04822805, 30/03/2021). METHODS: Eligible patients had a histological diagnosis of rHGG with first or subsequent recurrences. All patients received oral anlotinib 12 mg or 10 mg on days 1-14 (repeated every 21 days). In cases where brain magnetic resonance imaging examination revealed an increase in peritumoral edema without worsening of symptoms, patients received a temporary treatment of intravenous bevacizumab 10 mg/kg to alleviate edema. The primary endpoint was the median progression-free survival (mPFS), and the secondary endpoints included median overall survival (mOS), objective response rate (ORR), disease control rate (DCR), and safety. RESULTS: Twenty-five patients with rHGG were included in the efficacy and safety assessments. Eighteen patients received anlotinib alone, and seven patients received anlotinib in combination with Bev. For all patients, the mPFS and mOS were 5.0 months and 13.6 months, respectively. The ORR was 32%, and the DCR was 96%. It is noteworthy that the survival and response data of recurrent glioblastoma (rGBM) exhibit similarities to those of rHGG. For rGBM patients, there were no significant differences in mPFS, mOS, ORR, or DCR between the anlotinib alone and anlotinib + Bev groups. However, the incidence of treatment-related adverse events of any grade was higher in the anlotinib + Bev group compared to the anlotinib alone group (100% vs. 78%, p = 0.041). CONCLUSIONS: Both anlotinib alone and its combination with Bev demonstrated good efficacy and safety in the treatment of rHGG.


Assuntos
Glioblastoma , Glioma , Humanos , Bevacizumab/efeitos adversos , Estudos Prospectivos , Fator A de Crescimento do Endotélio Vascular , Glioma/tratamento farmacológico , Glioma/patologia , Edema
11.
J Magn Reson Imaging ; 59(1): 211-222, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37078514

RESUMO

BACKGROUND: How brain neural activity changes at multiple time points throughout the day and the neural mechanisms underlying time-dependent modulation of vigilance are less clear. PURPOSE: To explore the effect of circadian rhythms and homeostasis on brain neural activity and the potential neural basis of time-dependent modulation of vigilance. STUDY TYPE: Prospective. SUBJECTS: A total of 30 healthy participants (22-27 years old). FIELD STRENGTH/SEQUENCE: A 3.0 T, T1-weighted imaging, echo-planar functional MRI (fMRI). ASSESSMENT: Six resting-state fMRI (rs-fMRI) scanning sessions were performed at fixed times (9:00 h, 13:00 h, 17:00 h, 21:00 h, 1:00 h, and 5:00 h) to investigate fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity (ReHo) diurnal variation. The fALFF/ReHo and the result of the psychomotor vigilance task were used to assess local neural activity and vigilance. STATISTICAL TESTS: One-way repeated measures analysis of variance (ANOVA) was used to assess changes in vigilance (P < 0.05) and neural activity in the whole brain (P < 0.001 at the voxel level and P < 0.01 at the cluster level, Gaussian random field [GRF] corrected). Correlation analysis was used to examine the relationship between neural activity and vigilance at all-time points of the day. RESULTS: The fALFF/ReHo in the thalamus and some perceptual cortices tended to increase from 9:00 h to 13:00 h and from 21:00 h to 5:00 h, whereas the key nodes of the default mode network (DMN) tended to decrease from 21:00 h to 5:00 h. The vigilance tended to decrease from 21:00 h to 5:00 h. The fALFF/ReHo in the thalamus and some perceptual cortices was negatively correlated with vigilance at all-time points of the day, whereas the fALFF/ReHo in the key nodes of the DMN was positively correlated with vigilance. DATA CONCLUSION: Neural activities in the thalamus and some perceptual cortices show similar trends throughout the day, whereas the key nodes of the DMN show roughly opposite trends. Notably, diurnal variation of the neural activity in these brain regions may be an adaptive or compensatory response to changes in vigilance. EVIDENCE LEVEL: 1. TECHNICAL EFFICACY: 1.


Assuntos
Encéfalo , Imageamento por Ressonância Magnética , Humanos , Adulto Jovem , Adulto , Imageamento por Ressonância Magnética/métodos , Estudos Prospectivos , Mapeamento Encefálico/métodos , Homeostase
12.
J Magn Reson Imaging ; 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38284542

RESUMO

BACKGROUND: The changes that occur in the gamma-aminobutyric acid (GABA) levels within specific brain regions throughout the day are less clear. PURPOSE: To evaluate the daily fluctuations of GABA levels within the parietal lobe (PL) and anterior cingulate gyrus (ACC) regions and explore their association with melatonin (MT) levels, heart rate (HR), and blood pressure. STUDY TYPE: Prospective. SUBJECTS: 26 healthy young adults (15 males and 11 females aged 22-27 years). FIELD STRENGTH/SEQUENCE: 3.0T, T1-weighted imaging, Mescher-Garwood point resolved spectroscopy (MEGA-PRESS) sequence. ASSESSMENT: The acquired GABA signal contained the overlapping signals of macromolecules and homocarnosine, hence expressed as GABA+. The creatine (Cr) signal was applied as an endogenous reference. The GABA+, GABA+/Cr were measured at six different time points (1:00, 5:00, 9:00, 13:00, 17:00, and 21:00 hours) using MEGA-PRESS. The blood pressure, HR and sputum MT levels, were also acquired. STATISTICAL TESTS: The one-way repeated-measures analysis of variance (ANOVA) was used to evaluate the GABA, blood pressure, HR, and MT levels throughout the day. A general linear model was used to find the correlation between GABA and blood pressure, HR, and MT. P < 0.05 was statistically significant. RESULTS: Significant variations in GABA+/Cr and GABA+ levels were observed throughout the day within the PL region. The lowest levels were recorded at 9:00 hour (GABA+/Cr: 0.100 ± 0.003,GABA+:1.877 ± 0.051 i.u) and the highest levels were recorded at 21:00 hour (GABA+/Cr: 0.115 ± 0.003, GABA+:2.122 ± 0.052 i.u). The MT levels were positively correlated with GABA+/Cr (r = 0.301) and GABA+ (r = 0.312) within the ACC region. DATA CONCLUSION: GABA+/Cr and GABA+ in ACC are positively correlated with MT. GABA levels in the PL have diurnal differences. These findings may indicate that the body's GABA level change in response to the light-dark cycle. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 2.

13.
J Sleep Res ; : e14190, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38453144

RESUMO

The presence of a circadian cycle of cerebral blood flow may have implications for the occurrence of daily variations in cerebrovascular events in humans, but how cerebral blood flow varies throughout the day and its mechanism are still unclear. The study aimed to explore the diurnal variation of cerebral blood flow in healthy humans and its possible mechanisms. Arterial spin labelling images were collected at six time-points (09:00 hours, 13:00 hours, 17:00 hours, 21:00 hours, 01:00 hours, 05:00 hours) from 18 healthy participants (22-39 years old; eight females) to analyse diurnal variations in cerebral blood flow. Resting heart rate and blood pressure at six time-points and blood indicators (20-hydroxyeicosatetraenoic acid, epoxyeicosatrienoic acids, prostaglandin E2, noradrenaline and nitric oxide) related to cerebral vascular tone at two time-points (09:00 hours and 21:00 hours) were collected to analyse possible influences on diurnal variations in cerebral blood flow. From 21:00 hours to 05:00 hours, parietal cortical relative cerebral blood flow tended to increase, while frontal cortical and cerebellar relative cerebral blood flow tended to decrease. There was a time-dependent negative correlation between parietal cortical relative cerebral blood flow and resting heart rate, whereas there was a time-dependent positive correlation between cerebellar relative cerebral blood flow and resting heart rate. The change of parietal cortical relative cerebral blood flow was positively correlated with the change of nitric oxide. There was also a time-dependent positive correlation between mean arterial pressure and mean whole-brain cerebral blood flow. The findings indicated that parietal cortical relative cerebral blood flow and frontal cortical/cerebellar relative cerebral blood flow showed roughly opposite trends throughout the day. The diurnal variations in relative cerebral blood flow were regional-specific. Diurnal variation of nitric oxide and neurogenic regulation may be potential mechanisms for diurnal variation in regional relative cerebral blood flow.

14.
J Opt Soc Am A Opt Image Sci Vis ; 41(6): B48-B54, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38856403

RESUMO

Structured beams have attracted increasing interest in free-space and fiber-based optical communications. Underwater wireless optical communication (UWOC) is becoming a prospective technique in marine exploration. We investigated UWOC performance using different representative structured beams. The transmission performances of the Gaussian, Bessel-Gaussian (BG), Ince-Gaussian (IG), and radially polarized Gaussian (RPG) beams were experimentally demonstrated and evaluated in underwater channels subjected to thermal gradient. The experimental results show that the BG, IG, and RPG perform better against the thermal gradient. Compared with the Gaussian beams, the beam wanders of BG, IG, and RPG beams under the thermal gradient have been reduced by 56.9%, 8.2%, and 59%, the scintillation indices have been decreased by 12.8%, 17.3%, and 28.9%, and the BER performance of the BG, IG, and RPG beams have been improved by ∼5.5, ∼3.7, and ∼5.2d B at the forward error correction threshold (FEC threshold). Based on the above results, the RPG beam is a more promising light source for UWOC. The experimental results provide a promising beam choice for UWOC.

15.
Nucleic Acids Res ; 50(4): 2005-2018, 2022 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-35137179

RESUMO

The second cell fate decision in the early stage of mammalian embryonic development is pivotal; however, the underlying molecular mechanism is largely unexplored. Here, we report that Prmt1 acts as an important regulator in primitive endoderm (PrE) formation. First, Prmt1 depletion promotes PrE gene expression in mouse embryonic stem cells (ESCs). Single-cell RNA sequencing and flow cytometry assays demonstrated that Prmt1 depletion in mESCs contributes to an emerging cluster, where PrE genes are upregulated significantly. Furthermore, the efficiency of extraembryonic endoderm stem cell induction increased in Prmt1-depleted ESCs. Second, the pluripotency factor Klf4 methylated at Arg396 by Prmt1 is required for recruitment of the repressive mSin3a/HDAC complex to silence PrE genes. Most importantly, an embryonic chimeric assay showed that Prmt1 inhibition and mutated Klf4 at Arg 396 induce the integration of mouse ESCs into the PrE lineage. Therefore, we reveal a regulatory mechanism for cell fate decisions centered on Prmt1-mediated Klf4 methylation.


Assuntos
Embrião de Mamíferos/metabolismo , Endoderma , Proteína-Arginina N-Metiltransferases/metabolismo , Animais , Diferenciação Celular , Desenvolvimento Embrionário , Endoderma/metabolismo , Feminino , Fator 4 Semelhante a Kruppel/metabolismo , Camundongos , Células-Tronco Embrionárias Murinas , Gravidez
16.
Adv Exp Med Biol ; 1445: 151-156, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38967757

RESUMO

Skin is the most prominent tissue and organ, as well as the first line of defence, of the body. Because it is situated on the body's surface, it is constantly exposed to microbial, chemical, and physical factors such as mechanical stimulation. Therefore, skin has evolved substantial immune defences, regenerative ability, and anti-injury capacity. Epidermal cells produce antibacterial peptides that play a role in immune defence under physiological conditions. Additionally, IgG or IgA in the skin also participates in local anti-infective immunity. However, based on the classical theory of immunology, Ig can only be produced by B cells which should be derived from local B cells. This year, thanks to the discovery of Ig derived from non B cells (non B-Ig), Ig has also been found to be expressed in epidermal cells and contributes to immune defence. Epidermal cell-derived IgG and IgA have been demonstrated to have potential antibody activity by binding to pathogens. However, these epidermal cell-derived Igs show different microbial binding characteristics. For instance, IgG binds to Staphylococcus aureus and IgA binds to Staphylococcus epidermidis. Epidermal cells producing IgG and IgA may serve as an effective defense mechanism alongside B cells, providing a novel insight into skin immunity.


Assuntos
Imunoglobulina A , Pele , Humanos , Imunoglobulina A/imunologia , Imunoglobulina A/metabolismo , Pele/imunologia , Animais , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Linfócitos B/imunologia , Imunoglobulinas/imunologia , Imunoglobulinas/metabolismo , Staphylococcus aureus/imunologia , Staphylococcus epidermidis/imunologia , Epiderme/imunologia , Epiderme/metabolismo , Células Epidérmicas/imunologia , Células Epidérmicas/metabolismo
17.
Angew Chem Int Ed Engl ; 63(12): e202319773, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38279666

RESUMO

We report herein the development of palladium-catalyzed deacylative deuteration of arylketone oxime ethers. This protocol features excellent functional group tolerance, heterocyclic compatibility, and high deuterium incorporation levels. Regioselective deuteration of some biologically important drugs and natural products are showcased via Friedel-Crafts acylation and subsequent deacylative deuteration. Vicinal meta-C-H bond functionalization (including fluorination, arylation, and alkylation) and para-C-H bond deuteration of electro-rich arenes are realized by using the ketone as both directing group and leaving group, which is distinct from aryl halide in conventional dehalogenative deuteration.

18.
Cancer Sci ; 114(2): 370-383, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36310398

RESUMO

Although effective, immune checkpoint blockade induces response in only a subset of cancer patients. There is an urgent need to discover new immune checkpoint targets. Recently, it was found that a class of sialic acid-binding immunoglobulin-like lectins (Siglecs) expressed on the surface of T cells in cancer patients inhibit T cell activation through their intracellular immunosuppressive motifs by recognizing sialic acid-carrying glycans, sialoglycans. However, ligands of Siglecs remain elusive. Here, we report sialylated IgG (SIA-IgG), a ligand to Siglec-7, that is highly expressed in epithelial cancer cells. SIA-IgG binds Siglec-7 directly and inhibits TCR signals. Blocking of either SIA-IgG or Siglec-7 elicited potent antitumor immunity in T cells. Our study suggests that blocking of Siglec-7/SIA-IgG offers an opportunity to enhance immune function while simultaneously sensitizing cancer cells to immune attack.


Assuntos
Ácido N-Acetilneuramínico , Neoplasias , Humanos , Ácido N-Acetilneuramínico/metabolismo , Linfócitos T/metabolismo , Lectinas Semelhantes a Imunoglobulina de Ligação ao Ácido Siálico/metabolismo , Polissacarídeos , Imunoglobulina G
19.
Opt Express ; 31(15): 24067-24084, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37475243

RESUMO

Prompted by alleviating the random perturbation of underwater channel and enhancing the performance for the orbital angular momentum (OAM) -based underwater wireless optical communication (UWOC), the quasi-Airy Hypergeometric-Gaussian (QAHyGG) vortex beam is first proposed and demonstrated. Moreover, an underwater channel model is first modified for more accurate simulated results of the propagation property of various beams. Based on the modified model, the transmission and communication performance of three different OAM-carrying beams (the Gauss vortex (GV) beam, the Hypergeometric-Gaussian (HyGG) vortex beam, and the QAHyGG vortex beam) are comparatively studied. In addition, the parameters optimization of the QAHyGG vortex beam is made for further enhancing the average capacity. The results show that the QAHyGG vortex beam exhibits higher received power and lower crosstalk probability under different channel conditions. The average capacity of the QAHyGG vortex beam has enhanced by ∼8% and ∼27% compared with the HyGG vortex beam and the GV beam at 100m, respectively. The QAHyGG vortex beam is more suitable in an OAM-based UWOC system with a limited-size receiving aperture or lower transmit power. Besides, the average capacity will improve effectively at longer distances with the optimized beam parameters. These research results can provide advances in designing the practical OAM-based UWOC system.

20.
Toxicol Appl Pharmacol ; 474: 116613, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37414289

RESUMO

Alzheimer's disease (AD) is a common neurodegenerative disease in the elderly. Dysregulation of intracellular Ca2+ homeostasis plays a critical role in the pathological development of AD. Dauricine (DAU) is a bisbenzylisoquinoline alkaloid isolated from Menispermum dauricum DC., which can prevent the influx of extracellular Ca2+ and inhibit the release of Ca2+ from the endoplasmic reticulum. DAU has a potential for anti-AD. However, it is unclear whether DAU can exert its anti-AD effect in vivo by regulating the Ca2+ related signaling pathways. Here, we investigated the effect and mechanism of DAU on D-galactose and AlCl3 combined-induced AD mice based on the Ca2+/CaM pathway. The results showed that DAU (1 mg/kg and 10 mg/kg for 30 days) treatment attenuated learning and memory deficits and improved the nesting ability of AD mice. The HE staining assay showed that DAU could inhibit the histopathological alterations and attenuate neuronal damage in the hippocampus and cortex of AD mice. Studies on the mechanism indicated that DAU decreased the phosphorylation of CaMKII and Tau and reduced the formation of NFTs in the hippocampus and cortex. DAU treatment also reduced the abnormally high expression of APP, BACE1, and Aß1-42, which inhibited the deposition of Aß plaques. Moreover, DAU could decrease Ca2+ levels and inhibit elevated CaM protein expression in the hippocampus and cortex of AD mice. The molecular docking results showed that DAU may have a high affinity with CaM or BACE1. DAU has a beneficial impact on pathological changes in AD mice induced by D-galactose and AlCl3 and may act by negative regulation of the Ca2+/CaM pathway and its downstream molecules such as CaMKII and BACE1.


Assuntos
Doença de Alzheimer , Benzilisoquinolinas , Disfunção Cognitiva , Doenças Neurodegenerativas , Camundongos , Animais , Doença de Alzheimer/induzido quimicamente , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Galactose/toxicidade , Galactose/metabolismo , Secretases da Proteína Precursora do Amiloide/efeitos adversos , Secretases da Proteína Precursora do Amiloide/metabolismo , Doenças Neurodegenerativas/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Simulação de Acoplamento Molecular , Ácido Aspártico Endopeptidases/efeitos adversos , Ácido Aspártico Endopeptidases/metabolismo , Benzilisoquinolinas/efeitos adversos , Hipocampo , Disfunção Cognitiva/induzido quimicamente , Disfunção Cognitiva/tratamento farmacológico , Modelos Animais de Doenças , Peptídeos beta-Amiloides/metabolismo , Camundongos Transgênicos
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