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1.
Proc Natl Acad Sci U S A ; 120(6): e2221637120, 2023 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-36716376

RESUMO

Lipids establish the specialized thylakoid membrane of chloroplast in eukaryotic photosynthetic organisms, while the molecular basis of lipid transfer from other organelles to chloroplast remains further elucidation. Here we revealed the structural basis of Arabidopsis Sec14 homology proteins AtSFH5 and AtSFH7 in transferring phosphatidic acid (PA) from endoplasmic reticulum (ER) to chloroplast, and whose function in regulating the lipid composition of chloroplast and thylakoid development. AtSFH5 and AtSFH7 localize at both ER and chloroplast, whose deficiency resulted in an abnormal chloroplast structure and a decreased thickness of stacked thylakoid membranes. We demonstrated that AtSFH5, but not yeast and human Sec14 proteins, could specifically recognize and transfer PA in vitro. Crystal structures of the AtSFH5-Sec14 domain in complex with L-α-phosphatidic acid (L-α-PA) and 1,2-dipalmitoyl-sn-glycero-3-phosphate (DPPA) revealed that two PA ligands nestled in the central cavity with different configurations, elucidating the specific binding mode of PA to AtSFH5, different from the reported phosphatidylethanolamine (PE)/phosphatidylcholine (PC)/phosphatidylinositol (PI) binding modes. Quantitative lipidomic analysis of chloroplast lipids showed that PA and monogalactosyldiacylglycerol (MGDG), particularly the C18 fatty acids at sn-2 position in MGDG were significantly decreased, indicating a disrupted ER-to-plastid (chloroplast) lipid transfer, under deficiency of AtSFH5 and AtSFH7. Our studies identified the role and elucidated the structural basis of plant SFH proteins in transferring PA between organelles, and suggested a model for ER-chloroplast interorganelle phospholipid transport from inherent ER to chloroplast derived from endosymbiosis of a cyanobacteriumproviding a mechanism involved in the adaptive evolution of cellular plastids.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Cloroplastos , Ácidos Fosfatídicos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cloroplastos/metabolismo , Ácidos Fosfatídicos/metabolismo , Tilacoides/metabolismo
2.
Stem Cells ; 42(7): 662-674, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38655781

RESUMO

Cortactin (CTTN), a cytoskeletal protein and substrate of Src kinase, is implicated in tumor aggressiveness. However, its role in bone cell differentiation remains unknown. The current study revealed that CTTN was upregulated during osteoblast and adipocyte differentiation. Functional experiments demonstrated that CTTN promoted the in vitro differentiation of mesenchymal stem/progenitor cells into osteogenic and adipogenic lineages. Mechanistically, CTTN was able to stabilize the protein level of mechanistic target of rapamycin kinase (mTOR), leading to the activation of mTOR signaling. In-depth investigation revealed that CTTN could bind with casitas B lineage lymphoma-c (c-CBL) and counteract the function of c-CBL, a known E3 ubiquitin ligase responsible for the proteasomal degradation of mTOR. Silencing c-Cbl alleviated the impaired differentiation of osteoblasts and adipocytes caused by CTTN siRNA, while silencing mTOR mitigated the stimulation of osteoblast and adipocyte differentiation induced by CTTN overexpression. Notably, transplantation of CTTN-silenced bone marrow stromal cells (BMSCs) into the marrow of mice led to a reduction in trabecular bone mass, accompanied by a decrease in osteoblasts and an increase in osteoclasts. Furthermore, CTTN-silenced BMSCs expressed higher levels of receptor activator of nuclear factor κB ligand (RANKL) than control BMSCs did and promoted osteoclast differentiation when cocultured with bone marrow-derived osteoclast precursor cells. This study provides evidence that CTTN favors osteoblast differentiation by counteracting the c-CBL-induced degradation of mTOR and inhibits osteoclast differentiation by downregulating the expression of RANKL. It also suggests that maintaining an appropriate level of CTTN expression may be advantageous for maintaining bone homeostasis.


Assuntos
Diferenciação Celular , Cortactina , Homeostase , Osteoblastos , Osteoclastos , Proteínas Proto-Oncogênicas c-cbl , Osteoblastos/metabolismo , Osteoblastos/citologia , Animais , Osteoclastos/metabolismo , Camundongos , Cortactina/metabolismo , Cortactina/genética , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Proteínas Proto-Oncogênicas c-cbl/genética , Serina-Treonina Quinases TOR/metabolismo , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/citologia , Osteogênese , Osso e Ossos/metabolismo , Adipócitos/metabolismo , Adipócitos/citologia , Ligante RANK/metabolismo , Transdução de Sinais
3.
J Immunol ; 210(1): 72-81, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36426999

RESUMO

Fish possess a powerful IFN system to defend against aquatic virus infections. Nevertheless, spring viremia of carp virus (SVCV) causes large-scale mortality in common carp and significant economic losses to aquaculture. Therefore, it is necessary to investigate the strategies used by SVCV to escape the IFN response. In this study, we show that the SVCV nucleoprotein (N protein) negatively regulates cellular IFN production by degrading stimulator of IFN genes (STING) via the autophagy-lysosome-dependent pathway. First, overexpression of N protein inhibited the IFN promoter activation induced by polyinosinic-polycytidylic acid and STING. Second, the N protein associated with STING and experiments using a dominant-negative STING mutant demonstrated that the N-terminal transmembrane domains of STING were indispensable for this interaction. Then, the N protein degraded STING in a dose-dependent and autophagy-lysosome-dependent manner. Intriguingly, in the absence of STING, individual N proteins could not elicit host autophagic flow. Furthermore, the autophagy factor Beclin1 was found to interact with the N protein to attenuate N protein-mediated STING degradation after beclin1 knockdown. Finally, the N protein remarkably weakened STING-enhanced cellular antiviral responses. These findings reveal that SVCV uses the host autophagic process to achieve immune escape, thus broadening our understanding of aquatic virus pathogenesis.


Assuntos
Carpas , Doenças dos Peixes , Infecções por Rhabdoviridae , Rhabdoviridae , Animais , Proteínas do Nucleocapsídeo , Viremia , Proteína Beclina-1 , Rhabdoviridae/fisiologia , Lisossomos , Autofagia
4.
J Cell Mol Med ; 28(15): e18574, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39087591

RESUMO

Osteoarthritis (OA) is a widespread inflammatory joint disease with significant global disability burden. Cuproptosis, a newly identified mode of cell death, has emerged as a crucial factor in various pathological conditions, including OA. In this context, our study aims to investigate the intrinsic relationship between cuproptosis-related genes (CRGs) and OA, and assess their potential as biomarkers for OA diagnosis and treatment. Datasets from the GEO databases were analysed the differential expression of CRGs, leading to the identification of 10 key CRGs (CDKN2A, DLD, FDX1, GLS, LIAS, LIPT1, MTF1, PDHA1, DLAT and PDHB). A logistic regression analysis and calibration curves were used to show excellent diagnostic accuracy. Consensus clustering revealed two CRG patterns, with Cluster 1 indicating a closer association with OA progression. RT-PCR confirmed a significant increase in the expression levels of these nine key genes in IL-1ß-induced C28/i2 cells, and the expression of CDKN2A and FDX1 were also elevated in conditioned monocytes, while the expression of GLS and MTF1 were significantly decreased. In vitro experiments demonstrated that the expression levels of these 7/10 CRGs were significantly increased in chondrocytes induced by IL-1ß, and upon stimulation with cuproptosis inducers, chondrocyte apoptosis was exacerbated, accompanied by an increase in the expression of cuproptosis-related proteins. These further substantiated our research findings and indicated that the nine selected cuproptosis genes have high potential for application in the diagnosis of OA.


Assuntos
Condrócitos , Osteoartrite , Humanos , Osteoartrite/genética , Fatores de Risco , Condrócitos/metabolismo , Condrócitos/patologia , Biomarcadores/metabolismo , Interleucina-1beta/genética , Regulação da Expressão Gênica , Monócitos/metabolismo , Perfilação da Expressão Gênica
5.
Stroke ; 55(3): 586-594, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38275115

RESUMO

BACKGROUND: Sleep-disordered breathing (SDB) and atrial fibrillation (AF) are highly prevalent in patients with stroke and are recognized as independent risk factors for stroke. Little is known about the impact of comorbid SDB and AF on long-term outcomes after stroke. METHODS: In this prospective cohort study, 353 patients with acute ischemic stroke or transient ischemic attacks were analyzed. Patients were screened for SDB by respiratory polygraphy during acute hospitalization. Screening for AF was performed using a 7-day ECG up to 3× in the first 6 months. Follow-up visits were scheduled at 1, 3, 12, 24, and 36 months poststroke. Cox regression models adjusted for various factors (age, sex, body mass index, hypertension, diabetes, dyslipidemia, and heart failure) were used to assess the impact of comorbid SDB and AF on subsequent death or cerebro-cardiovascular events. RESULTS: Among 353 patients (299 ischemic stroke and 54 transient ischemic attacks), median age, 67 (interquartile range, 57-74) years with 63% males. Moderate-to-severe SDB (apnea-hypopnea index score, ≥15/h) was present in 118 (33.4%) patients. Among the 56 (15.9%) patients with AF, 28 had comorbid moderate-to-severe SDB and AF. Over 36 months, there were 12 deaths and 67 recurrent cerebro-cardiovascular events. Patients with comorbid moderate-to-severe SDB and AF had a higher risk of subsequent death or cerebro-cardiovascular events compared with those with only moderate-to-severe SDB without AF (hazard ratio, 2.49 [95% CI, 1.18-5.24]) and to those without moderate-to-severe SDB or AF (hazard ratio, 2.25 [95% CI, 1.12-4.50]). However, no significant difference was found between the comorbid moderate-to-severe SDB and AF group and the group with only AF without moderate-to-severe SDB (hazard ratio, 1.64 [95% CI, 0.62-4.36]). CONCLUSIONS: Comorbid moderate-to-severe SDB and AF significantly increase the risk of long-term mortality or recurrent cerebro-cardiovascular events after acute ischemic stroke. Considering both conditions as cumulative and modifiable cerebro-cardiovascular risk factors is of interest for the management of acute stroke. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02559739.


Assuntos
Fibrilação Atrial , Ataque Isquêmico Transitório , AVC Isquêmico , Síndromes da Apneia do Sono , Acidente Vascular Cerebral , Masculino , Humanos , Idoso , Feminino , Ataque Isquêmico Transitório/epidemiologia , Ataque Isquêmico Transitório/complicações , Fibrilação Atrial/complicações , AVC Isquêmico/complicações , Estudos Prospectivos , Síndromes da Apneia do Sono/complicações , Síndromes da Apneia do Sono/epidemiologia , Síndromes da Apneia do Sono/diagnóstico , Fatores de Risco
6.
Anal Chem ; 96(17): 6738-6745, 2024 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-38642036

RESUMO

The detection of low-abundance microribonucleic acid (miRNA) frequently adopted nucleic acid sequence-based amplification detection, which was found to have poor selectivity for the nonspecific amplification of template-dependent ligation in enzyme-mediated cascade reactions. Here, a highly selective detection of miRNAs was developed that combined microsphere-enhanced fluorescence (MSEF) and solid-phase base-paired hybridization. The target miRNA could be accurately and quantitatively identified through the solid-phase hybridization assay on the surface of an optical microsphere, while the detected fluorescence signal could be physically amplified by MSEF. Hereinto, the optical microsphere acted as the fluorescence amplifier and whose surface supplied the space to carry out base-paired hybridization to recognize the target miRNA via the immobilized capture DNA sequence. The detected fluorescence signal of the single-base mismatched miRNA-21 sequence was just around 12% of that of the target miRNA-21 sequence in the measurement of model miRNA-21, while the limit of detection of miRNA-21 could be 1.0 fM. The developed detection of miRNA on an optical microsphere was demonstrated to be an excellent physically amplified method to selectively and sensitively detect the target miRNA and magnificently avoid the nonspecific amplification and false-positive results, which is expected to have wide applications in pathematology, pharmacology, clinic diagnosis, and on-site screening fields as well.


Assuntos
MicroRNAs , Microesferas , Hibridização de Ácido Nucleico , MicroRNAs/análise , Fluorescência , Humanos , Espectrometria de Fluorescência , Corantes Fluorescentes/química , Limite de Detecção
7.
Biochem Biophys Res Commun ; 735: 150451, 2024 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-39094233

RESUMO

Cerebral small vascular disease (CSVD) has a high incidence worldwide, but its pathological mechanisms remain poorly understood due to the lack of proper animal models. The current animal models of CSVD have several limitations such as high mortality rates and large-sized lesions, and thus it is urgent to develop new animal models of CSVD. Ultrasound can activate protoporphyrin to produce reactive oxygen species in a liquid environment. Here we delivered protoporphyrin into cerebral small vessels of rat brain through polystyrene microspheres with a diameter of 15 µm, and then performed transcranial ultrasound stimulation (TUS) on the model rats. We found that TUS did not affect the large vessels or cause large infarctions in the brain of model rats. The mortality rates were also comparable between the sham and model rats. Strikingly, TUS induced several CSVD-like phenotypes such as cerebral microinfarction, white matter injuries and impaired integrity of endothelial cells in the model rats. Additionally, these effects could be alleviated by antioxidant treatment with N-acetylcysteine (NAC). As control experiments, TUS did not lead to cerebral microinfarction in the rat brain when injected with the polystyrene microspheres not conjugated with protoporphyrin. In sum, we generated a rat model of CSVD that may be useful for the mechanistic study and drug development for CSVD.


Assuntos
Doenças de Pequenos Vasos Cerebrais , Modelos Animais de Doenças , Protoporfirinas , Ratos Sprague-Dawley , Animais , Doenças de Pequenos Vasos Cerebrais/patologia , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Protoporfirinas/farmacologia , Masculino , Ratos , Encéfalo/patologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/diagnóstico por imagem , Ondas Ultrassônicas , Acetilcisteína/farmacologia , Microesferas
8.
J Transl Med ; 22(1): 499, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38796415

RESUMO

BACKGROUND: Myocardial ischemia-reperfusion injury (MIRI) is caused by reperfusion after ischemic heart disease. LncRNA Snhg1 regulates the progression of various diseases. N6-methyladenosine (m6A) is the frequent RNA modification and plays a critical role in MIRI. However, it is unclear whether lncRNA Snhg1 regulates MIRI progression and whether the lncRNA Snhg1 was modified by m6A methylation. METHODS: Mouse cardiomyocytes HL-1 cells were utilized to construct the hypoxia/reoxygenation (H/R) injury model. HL-1 cell viability was evaluated utilizing CCK-8 method. Cell apoptosis, mitochondrial reactive oxygen species (ROS), and mitochondrial membrane potential (MMP) were quantitated utilizing flow cytometry. RNA immunoprecipitation and dual-luciferase reporter assays were applied to measure the m6A methylation and the interactions between lncRNA Snhg1 and targeted miRNA or target miRNAs and its target gene. The I/R mouse model was constructed with adenovirus expressing lncRNA Snhg1. HE and TUNEL staining were used to evaluate myocardial tissue damage and apoptosis. RESULTS: LncRNA Snhg1 was down-regulated after H/R injury, and overexpressed lncRNA Snhg1 suppressed H/R-stimulated cell apoptosis, mitochondrial ROS level and polarization. Besides, lncRNA Snhg1 could target miR-361-5p, and miR-361-5p targeted OPA1. Overexpressed lncRNA Snhg1 suppressed H/R-stimulated cell apoptosis, mitochondrial ROS level and polarization though the miR-361-5p/OPA1 axis. Furthermore, WTAP induced lncRNA Snhg1 m6A modification in H/R-stimulated HL-1 cells. Moreover, enforced lncRNA Snhg1 repressed I/R-stimulated myocardial tissue damage and apoptosis and regulated the miR-361-5p and OPA1 levels. CONCLUSION: WTAP-mediated m6A modification of lncRNA Snhg1 regulated MIRI progression through modulating myocardial apoptosis, mitochondrial ROS production, and mitochondrial polarization via miR-361-5p/OPA1 axis, providing the evidence for lncRNA as the prospective target for alleviating MIRI progression.


Assuntos
Apoptose , MicroRNAs , Dinâmica Mitocondrial , Traumatismo por Reperfusão Miocárdica , Miócitos Cardíacos , RNA Longo não Codificante , Animais , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , MicroRNAs/metabolismo , MicroRNAs/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/patologia , Camundongos , Apoptose/genética , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Linhagem Celular , Masculino , Camundongos Endogâmicos C57BL , GTP Fosfo-Hidrolases/metabolismo , GTP Fosfo-Hidrolases/genética , Espécies Reativas de Oxigênio/metabolismo , Adenosina/análogos & derivados , Adenosina/metabolismo , Sequência de Bases , Metilação , Potencial da Membrana Mitocondrial
9.
Microvasc Res ; 155: 104699, 2024 09.
Artigo em Inglês | MEDLINE | ID: mdl-38901735

RESUMO

Patients with Takotsubo syndrome displayed endothelial dysfunction, but underlying mechanisms have not been fully clarified. This study aimed to explore molecular signalling responsible for catecholamine excess induced endothelial dysfunction. Human cardiac microvascular endothelial cells were challenged by epinephrine to mimic catecholamine excess. Patch clamp, FACS, ELISA, PCR, and immunostaining were employed for the study. Epinephrine (Epi) enhanced small conductance calcium-activated potassium channel current (ISK1-3) through activating α1 adrenoceptor. Phenylephrine enhanced edothelin-1 (ET-1) and reactive oxygen species (ROS) production, and the effects involved contribution of ISK1-3. H2O2 enhanced ISK1-3 and ET-1 production. Enhancing ISK1-3 caused a hyperpolarization, which increases ROS and ET-1 production. BAPTA partially reduced phenylephrine-induced enhancement of ET-1 and ROS, suggesting that α1 receptor activation can enhance ROS/ET-1 generation in both calcium-dependent and calcium-independent ways. The study demonstrates that high concentration catecholamine can activate SK1-3 channels through α1 receptor-ROS signalling and increase ET-1 production, facilitating vasoconstriction.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 1 , Células Endoteliais , Epinefrina , Espécies Reativas de Oxigênio , Receptores Adrenérgicos alfa 1 , Transdução de Sinais , Canais de Potássio Ativados por Cálcio de Condutância Baixa , Vasoconstrição , Humanos , Canais de Potássio Ativados por Cálcio de Condutância Baixa/metabolismo , Receptores Adrenérgicos alfa 1/metabolismo , Receptores Adrenérgicos alfa 1/genética , Espécies Reativas de Oxigênio/metabolismo , Células Endoteliais/metabolismo , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/patologia , Agonistas de Receptores Adrenérgicos alfa 1/farmacologia , Vasoconstrição/efeitos dos fármacos , Células Cultivadas , Epinefrina/farmacologia , Peróxido de Hidrogênio/metabolismo , Potenciais da Membrana , Fenilefrina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Endotélio Vascular/metabolismo , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Canais de Potássio Éter-A-Go-Go
10.
Cancer Cell Int ; 24(1): 87, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38419028

RESUMO

BACKGROUND: As a key enzyme in ceramide synthesis, longevity assurance homologue 2 (LASS2) has been indicated to act as a tumour suppressor in a variety of cancers. Ferroptosis is involved in a variety of tumour processes; however, the role of LASS2 in regulating ferroptosis has yet to be explored. This article explores the potential underlying mechanisms involved. METHODS: Bioinformatics tools and immunohistochemical staining were used to evaluate LASS2 expression, and the results were analysed in relation to overall survival and clinical association in multiple cancers. Coimmunoprecipitation-coupled liquid chromatography-mass spectrometry (co-IP LC-MS) was performed to identify potential LASS2-interacting proteins in thyroid, breast, and liver cancer cell lines. Transcriptomics, proteomics and metabolomics analyses of multiple cancer cell types were performed using MS or LC-MS to further explore the underlying mechanisms involved. Among these tumour cells, the common LASS2 interaction partner transferrin receptor (TFRC) was analysed by protein-protein docking and validated by coimmunoprecipitation western blot, immunofluorescence, and proximity ligation assays. Then, we performed experiments in which tumour cells were treated with Fer-1 or erastin or left untreated, with or without inducing LASS2 overexpression, and assessed the molecular biological and cellular functions by corresponding analyses. RESULTS: Low LASS2 expression is correlated with adverse clinical characteristic and poor prognosis in patients with thyroid cancer, breast cancer or HCC. Multiomics analyses revealed significant changes in the ferroptosis signalling pathway, iron ion transport and iron homeostasis. Our in vitro experiments revealed that LASS2 overexpression regulated ferroptosis status in these tumour cells by affecting iron homeostasis, which in turn inhibited tumour migration, invasion and EMT. In addition, LASS2 overexpression reversed the changes in tumour cell metastasis induced by either Fer-1 or erastin. Mechanistically, LASS2 interacts directly with TFRC to regulate iron homeostasis in these tumour cells. CONCLUSIONS: In summary, our study reveals for the first time that LASS2 can inhibit tumour cell metastasis by interacting with TFRC to regulate iron metabolism and influence ferroptosis status in thyroid, breast, and liver cancer cells, these results suggest potential universal therapeutic targets for the treatment of these cancers.

11.
Diabetes Metab Res Rev ; 40(4): e3799, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38546139

RESUMO

AIMS: Previous studies have found that a single liver enzyme may predict gestational diabetes mellitus (GDM), but the results have been inconsistent. This study aimed to explore the associations of liver enzymes in early pregnancy with risk of GDM, as well as to independently rank risk factors. METHODS: This prospective cohort study included 1295 women who underwent liver enzyme measurements during early pregnancy and completed GDM assessment in mid-pregnancy. Logistic regression and restricted cubic spline analyses were conducted to assess the relationship between liver enzymes and risk of GDM. Back-propagation artificial neural network was performed to rank independently risk factors of GDM. RESULTS: Women diagnosed with GDM exhibited significantly higher levels of liver enzymes than those without GDM (all p < 0.05). The highest quartile of liver enzymes was associated with higher risk of GDM compared with the lowest quartile, with adjusted odds ratio (ORs) ranging from 2.76 to 8.11 (all p < 0.05). Moreover, the ORs of GDM increased linearly with liver enzymes level (all P for overall association <0.001). Furthermore, Back-propagation artificial neural network identified γ-gamma-glutamyl transferase (GGT) as accounting for the highest proportion in the ranking of GDM risk prediction weights (up to 20.8%). CONCLUSIONS: Single or total elevations of liver enzymes in early pregnancy could predict the GDM occurrence, in which GGT, alkaline Phosphatase, and aspartate aminotransferase were the three most important independent risk factors.


Assuntos
Diabetes Gestacional , Gravidez , Feminino , Humanos , Diabetes Gestacional/epidemiologia , Primeiro Trimestre da Gravidez , Estudos Prospectivos , Fatores de Risco , Fígado
12.
Circ Res ; 130(9): 1321-1341, 2022 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-35382554

RESUMO

BACKGROUND: Cerebral small vessel injury, including loss of endothelial tight junctions, endothelial dysfunction, and blood-brain barrier breakdown, is an early and typical pathology for Alzheimer's disease, cerebral amyloid angiopathy, and hypertension-related cerebral small vessel disease. Whether there is a common mechanism contributing to these cerebrovascular alterations remains unclear. Studies have shown an elevation of BACE1 (ß-site amyloid precursor protein cleaving enzyme 1) in cerebral vessels from cerebral amyloid angiopathy or Alzheimer's disease patients, suggesting that vascular BACE1 may involve in cerebral small vessel injury. METHODS: To understand the contribution of vascular BACE1 to cerebrovascular impairments, we combined cellular and molecular techniques, mass spectrometry, immunostaining approaches, and functional testing to elucidate the potential pathological mechanisms. RESULTS: We observe a 3.71-fold increase in BACE1 expression in the cerebral microvessels from patients with hypertension. Importantly, we discover that an endothelial tight junction protein, occludin, is a completely new substrate for endothelial BACE1. BACE1 cleaves occludin with full-length occludin reductions and occludin fragment productions. An excessive cleavage by elevated BACE1 induces membranal accumulation of caveolin-1 and subsequent caveolin-1-mediated endocytosis, resulting in lysosomal degradation of other tight junction proteins. Meanwhile, membranal caveolin-1 increases the binding to eNOS (endothelial nitric oxide synthase), together with raised circulating Aß (ß-amyloid peptides) produced by elevated BACE1, leading to an attenuation of eNOS activity and resultant endothelial dysfunction. Furthermore, the initial endothelial damage provokes chronic reduction of cerebral blood flow, blood-brain barrier leakage, microbleeds, tau hyperphosphorylation, synaptic loss, and cognitive impairment in endothelial-specific BACE1 transgenic mice. Conversely, inhibition of aberrant BACE1 activity ameliorates tight junction loss, endothelial dysfunction, and memory deficits. CONCLUSIONS: Our findings establish a novel and direct relationship between endothelial BACE1 and cerebral small vessel damage, indicating that abnormal elevation of endothelial BACE1 is a new mechanism for cerebral small vessel disease pathogenesis.


Assuntos
Doença de Alzheimer , Angiopatia Amiloide Cerebral , Doenças de Pequenos Vasos Cerebrais , Hipertensão , Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide , Animais , Ácido Aspártico Endopeptidases/genética , Ácido Aspártico Endopeptidases/metabolismo , Caveolina 1/genética , Caveolina 1/metabolismo , Angiopatia Amiloide Cerebral/complicações , Angiopatia Amiloide Cerebral/metabolismo , Humanos , Hipertensão/complicações , Camundongos , Camundongos Transgênicos , Óxido Nítrico Sintase Tipo III/metabolismo , Ocludina/metabolismo , Proteínas de Junções Íntimas , Junções Íntimas/metabolismo
13.
J Gastroenterol Hepatol ; 39(8): 1684-1694, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38747068

RESUMO

BACKGROUND AND AIM: The impact of cholecystectomy, which blocks the cholecystohepatic shunt pathway (CHSP), on the prognosis of patients with hepatocellular carcinoma (HCC) is unclear. Hepatic secondary bile acids (BAs) inhibit natural killer T (NKT) cell-mediated immunity against HCC, and the regulation of homeostasis of hepatic secondary BAs is controlled by the CHSP. However, the influence of CHSP on NKT cell-mediated immunity against HCC remains unclear. METHODS: The clinical data of hospitalized patients undergoing HCC resection were collected. Meanwhile, an in situ HCC mouse model was established, and the CHSP was augmented using oleanolic acid (OA). RESULTS: After 1:1 propensity score matching, Cox regression analysis revealed that cholecystectomy was an independent risk factor for HCC recurrence after hepatectomy (P = 0.027, hazard ratio: 1.599, 95% confidence interval: 1.055-2.422). Experimentally, when OA enhanced CHSP, a significant decrease was observed in the accumulation of secondary BAs in the livers of mice. Additionally, a significant increase was observed in the levels of C-X-C ligand 16 and interferon γ in the serum and tumor tissues. Further, the percentage of C-X-C receptor 6 (+) NKT cells in the tumor tissues increased significantly, and the growth of liver tumors was inhibited. CONCLUSIONS: This clinical study revealed that cholecystectomy promoted the recurrence after radical hepatectomy in patients with HCC. Preserving the normal-functioning gallbladder as much as possible during surgery may be beneficial to the patient's prognosis. Further investigation into the mechanism revealed that CHSP enhanced NKT cell-mediated immunity against HCC by reducing the hepatic accumulation of secondary BAs.


Assuntos
Ácidos e Sais Biliares , Carcinoma Hepatocelular , Neoplasias Hepáticas , Células T Matadoras Naturais , Animais , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/cirurgia , Células T Matadoras Naturais/imunologia , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/cirurgia , Ácidos e Sais Biliares/metabolismo , Masculino , Humanos , Feminino , Colecistectomia , Modelos Animais de Doenças , Camundongos , Hepatectomia , Pessoa de Meia-Idade , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/farmacologia , Fígado/metabolismo , Camundongos Endogâmicos C57BL , Imunidade Celular , Recidiva Local de Neoplasia/prevenção & controle , Interferon gama/metabolismo , Fatores de Risco , Idoso
14.
Biol Cybern ; 118(1-2): 127-143, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38644417

RESUMO

The cognitive impairment will gradually appear over time in Parkinson's patients, which is closely related to the basal ganglia-cortex network. This network contains two parallel circuits mediated by putamen and caudate nucleus, respectively. Based on the biophysical mean-field model, we construct a dynamic computational model of the parallel circuit in the basal ganglia-cortex network associated with Parkinson's disease dementia. The simulated results show that the decrease of power ratio in the prefrontal cortex is mainly caused by dopamine depletion in the caudate nucleus and is less related to that in the putamen, which indicates Parkinson's disease dementia may be caused by a lesion of the caudate nucleus rather than putamen. Furthermore, the underlying dynamic mechanism behind the decrease of power ratio is investigated by bifurcation analysis, which demonstrates that the decrease of power ratio is due to the change of brain discharge pattern from the limit cycle mode to the point attractor mode. More importantly, the spatiotemporal course of dopamine depletion in Parkinson's disease patients is well simulated, which states that with the loss of dopaminergic neurons projecting to the striatum, motor dysfunction of Parkinson's disease is first observed, whereas cognitive impairment occurs after a period of onset of motor dysfunction. These results are helpful to understand the pathogenesis of cognitive impairment and provide insights into the treatment of Parkinson's disease dementia.


Assuntos
Gânglios da Base , Demência , Modelos Neurológicos , Doença de Parkinson , Humanos , Doença de Parkinson/fisiopatologia , Doença de Parkinson/complicações , Doença de Parkinson/patologia , Gânglios da Base/fisiopatologia , Demência/fisiopatologia , Demência/patologia , Simulação por Computador , Vias Neurais/fisiopatologia , Córtex Cerebral/fisiopatologia , Dopamina/metabolismo
15.
Int J Med Sci ; 21(10): 1964-1975, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39113882

RESUMO

Endothelial dysfunction may contribute to pathogenesis of Takotsubo cardiomyopathy, but mechanism underlying endothelial dysfunction in the setting of catecholamine excess has not been clarified. The study reports that D1/D5 dopamine receptor signaling and small conductance calcium-activated potassium channels contribute to high concentration catecholamine induced endothelial cell dysfunction. For mimicking catecholamine excess, 100 µM epinephrine (Epi) was used to treat human cardiac microvascular endothelial cells. Patch clamp, FACS, ELISA, PCR, western blot and immunostaining analyses were performed in the study. Epi enhanced small conductance calcium-activated potassium channel current (ISK1-3) without influencing the channel expression and the effect was attenuated by D1/D5 receptor blocker. D1/D5 agonists mimicked the Epi effect, suggesting involvement of D1/D5 receptors in Epi effects. The enhancement of ISK1-3 caused by D1/D5 activation involved roles of PKA, ROS and NADPH oxidases. Activation of D1/D5 and SK1-3 channels caused a hyperpolarization, reduced NO production and increased ROS production. The NO reduction was membrane potential independent, while ROS production was increased by the hyperpolarization. ROS (H2O2) suppressed NO production. The study demonstrates that high concentration catecholamine can activate D1/D5 and SK1-3 channels through NADPH-ROS and PKA signaling and reduce NO production, which may facilitate vasoconstriction in the setting of catecholamine excess.


Assuntos
Células Endoteliais , Epinefrina , Espécies Reativas de Oxigênio , Transdução de Sinais , Humanos , Transdução de Sinais/efeitos dos fármacos , Células Endoteliais/metabolismo , Células Endoteliais/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Óxido Nítrico/metabolismo , Catecolaminas/metabolismo , Canais de Potássio Ativados por Cálcio de Condutância Baixa/metabolismo , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Endotélio Vascular/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , NADPH Oxidases/metabolismo , Receptores de Dopamina D5/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores Dopaminérgicos/metabolismo
16.
BMC Pregnancy Childbirth ; 24(1): 633, 2024 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-39358711

RESUMO

BACKGROUND: To investigate the association between serum branched chain amino acids (BCAAs), mammalian target of rapamycin (mTOR) levels and the risk of gestational diabetes mellitus (GDM) in pregnant women. METHODS: 1:1 matched case-control study was conducted including 66 GDM patients and 66 matched healthy pregnant women (± 3 years) in 2019, in China. Fasting bloods of pregnant women were collected in pregnancy at 24 ~ 28 weeks gestation. And the serum levels of valine (Val), leucine (Leu), isoleucine (Ile) and mTOR were determined. Conditional logistic regressions models were used to estimate the associations of BCAAs and mTOR concentrations with the risk of GDM. RESULTS: Concentrations of serum Val and mTOR in cases were significantly higher than that in controls (P < 0.05). After adjusted for the confounded factors, both the second tertile and the third tertile of mTOR increased the risk of GDM (OR = 11.771, 95%CI: 3.949-35.083; OR = 4.869 95%CI: 1.742-13.611, respectively) compared to the first tertile of mTOR. However, the second tertile of serum Val (OR = 0.377, 95%CI:0.149-0.954) and the second tertile of serum Leu (OR = 0.322, 95%CI: 0.129-0.811) decreased the risk of GDM compared to the first tertile of serum Val and Leu, respectively. The restricted cubic spline indicated a significant nonlinear association between the serum levels of mTOR and the risk of GDM (P values for non-linearity = 0.0058). CONCLUSION: We confirmed the association of higher mTOR with the increased risk of GDM in pregnant women. Pregnant women who were in the certain range level of Val and Leu were at lower risk of GDM. Our findings provided epidemiological evidence for the relation of serum BCAAs and mTOR with risk of GDM.


Assuntos
Aminoácidos de Cadeia Ramificada , Diabetes Gestacional , Serina-Treonina Quinases TOR , Humanos , Feminino , Diabetes Gestacional/sangue , Diabetes Gestacional/epidemiologia , Gravidez , Estudos de Casos e Controles , Serina-Treonina Quinases TOR/sangue , Adulto , Aminoácidos de Cadeia Ramificada/sangue , China/epidemiologia , Fatores de Risco , Leucina/sangue , Isoleucina/sangue , Valina/sangue
17.
Mikrochim Acta ; 191(4): 209, 2024 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-38499840

RESUMO

A novel colorimetric platform was designed for the determination of S. aureus by utilizing a dual-recognition strategy, where wheat germ agglutinin (WGA)-functionalized magnetic beads were served as separation elements to capture and enrich S. aureus efficiently from the matrix. Horseradish peroxidase (HRP) labeled chicken anti-protein A IgY (HRP-IgY) was used to label the captured S. aureus. A chicken IgY was introduced as a signal tracer to bind with staphylococcal protein A (SPA) on the surface of S. aureus, which can circumvent the interference from protein G-producing Streptococcus. Subsequently, the colorimetric signal was achieved by an HRP-catalyzed reaction, which was amplified by HRP-IgY bound by approximately 80,000 SPA molecules on one S. aureus. The entire detection process could be accomplished within 90 min. Under optimal conditions, the linear response of different S. aureus concentrations ranged from 7.8 × 102 to 2.0 × 105 CFU/mL and the limit of detection reached down to 3.9 × 102 CFU/mL. Some common non-target bacteria yielded negative results, indicating the excellent specificity of the method. The developed strategy was successfully applied to the determination of S. aureus in various types of samples with satisfactory recoveries. Therefore, the novel dual-recognition strategy possessed the advantages of high sensitivity, specificity, and low cost and exhibited considerable potential as a promising tool to defend public health.


Assuntos
Infecções Estafilocócicas , Staphylococcus aureus , Humanos , Aglutininas do Germe de Trigo , Colorimetria/métodos , Imunoglobulinas , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Peroxidase do Rábano Silvestre/metabolismo
18.
J Environ Manage ; 366: 121876, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39018855

RESUMO

Integrated MFC-MBR systems effectively remove antibiotics and control the release of antibiotic resistance genes (ARGs). However, the fouling layers on membranes can potentially act as reservoirs for ARGs. This study aims to elucidate the roles of membrane fouling layers and levels in influencing sulfamethoxazole (SMX) removal and ARGs control within an MFC-MBR system. Our findings demonstrate that low-intensity bioelectricity (400-500 mV) mitigates membrane fouling rates. The membrane fouling layer significantly contributes (39%-47%) to SMX removal compared to the cathode/anode zones. Higher extracellular polymeric substance (EPS) content and a lower protein/polysaccharide (PN/PS) ratio favor SMX removal by the membrane fouling layer. Across different levels of membrane fouling, the PN/PS ratio rather than EPS concentration plays a crucial role in SMX removal efficiency. The MFC-MBR with low fouling achieved superior SMX removal (69.1%) compared to medium (54.3%) and high fouling conditions (46.8%). The presence of ARGs in the membrane fouling layer increases with fouling formation, with intrinsic ARGs prevailing. Dense membrane fouling layers effectively retain ARGs, thereby reducing the risk of extracellular ARGs (eARGs) diffusion in effluents. These results provide insights into controlling ARGs in MFC-MBR systems and underscore the significant role of membrane fouling layers in antibiotics and ARGs removal.


Assuntos
Fontes de Energia Bioelétrica , Reatores Biológicos , Membranas Artificiais , Sulfametoxazol , Resistência Microbiana a Medicamentos/genética , Antibacterianos , Matriz Extracelular de Substâncias Poliméricas/metabolismo
19.
Molecules ; 29(16)2024 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-39202795

RESUMO

Significant interest has emerged for the application of Pd-In2O3 catalysts as high-performance catalysts for CO2 hydrogenation to CH3OH. However, precise active site control in these catalysts and understanding their reaction mechanisms remain major challenges. In this investigation, a series of Pd-InOx catalysts were synthesized, revealing three distinct types of active sites: In-O, Pd-O(H)-In, and Pd2In3. Lower Pd loadings exhibited Pd-O(H)-In sites, while higher loadings resulted in Pd2In3 intermetallic compounds. These variations impacted catalytic performance, with Pd-O(H)-In catalysts showing heightened activity at lower temperatures due to the enhanced CO2 adsorption and H2 activation, and Pd2In3 catalysts performing better at elevated temperatures due to the further enhanced H2 activation. In situ DRIFTS studies revealed an alteration in key intermediates from *HCOO over In-O bonds to *COOH over Pd-O(H)-In and Pd2In3 sites, leading to a shift in the main reaction pathway transition and product distribution. Our findings underscore the importance of active site engineering for optimizing catalytic performance and offer valuable insights for the rational design of efficient CO2 conversion catalysts.

20.
J Cell Mol Med ; 27(22): 3478-3490, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37610095

RESUMO

Breast cancer is a highly prevalent malignancy with the first morbidity and the primary reason for female cancer-related deaths worldwide. Acid ground nano-realgar processed product (NRPP) could inhibit breast cancer cell proliferation and induce autophagy in our previous research; however, the underlying mechanisms are still unclear. Therefore, this research aimed to verify whether NRPP induces breast cancer mitophagy and explore the mitophagy-mediated mechanism. Primarily, rhodamine-123 assay and transmission electron microscopy were applied to detect mitochondrial membrane potential (MMP) and ultrastructural changes in the MDA-MB-435S cells, respectively. Mito-Tracker Green/Lyso-Tracker Red staining, western blot, immunofluorescence and RT-PCR were used to explore molecular mechanisms of NRPP-induced mitophagy in vitro. MDA-MB-435S breast cancer xenograft models were established to assess the activity and mechanisms of NRPP in vivo. Our results showed that NRPP decreased MMP and increased autophagosome numbers in MDA-MB-435S cells and activated mitophagy. Furthermore, mitophagy was consolidated because mitochondria and lysosomes colocalized phenomenology were observed, and the expression of LC3II/I and COXIV was upregulated. Additionally, we found the p53/BNIP3/NIX pathway was activated. Finally, NRPP inhibited tumour growth and downregulated the levels of TNF-α, IL-1ß and IL-6. Necrosis, damaged mitochondria and autophagosomes were observed in xenograft tumour cells, and proteins and mRNA levels of LC3, p53, BNIP3 and NIX were increased. Overall, NRPP inhibited MDA-MB-435S cell proliferation and tumour growth by inducing mitophagy via the p53/BNIP3/NIX pathway. Thus, NRPP is a promising candidate for breast cancer treatment.


Assuntos
Neoplasias da Mama , Mitofagia , Humanos , Feminino , Mitofagia/genética , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Autofagia , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas de Membrana/genética , Proteínas Proto-Oncogênicas/metabolismo
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