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1.
Cell ; 185(14): 2523-2541.e30, 2022 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-35738284

RESUMO

Stem cell research endeavors to generate specific subtypes of classically defined "cell types." Here, we generate >90% pure human artery or vein endothelial cells from pluripotent stem cells within 3-4 days. We specified artery cells by inhibiting vein-specifying signals and vice versa. These cells modeled viral infection of human vasculature by Nipah and Hendra viruses, which are extraordinarily deadly (∼57%-59% fatality rate) and require biosafety-level-4 containment. Generating pure populations of artery and vein cells highlighted that Nipah and Hendra viruses preferentially infected arteries; arteries expressed higher levels of their viral-entry receptor. Virally infected artery cells fused into syncytia containing up to 23 nuclei, which rapidly died. Despite infecting arteries and occupying ∼6%-17% of their transcriptome, Nipah and Hendra largely eluded innate immune detection, minimally eliciting interferon signaling. We thus efficiently generate artery and vein cells, introduce stem-cell-based toolkits for biosafety-level-4 virology, and explore the arterial tropism and cellular effects of Nipah and Hendra viruses.


Assuntos
Vírus Hendra , Vírus Nipah , Células-Tronco Pluripotentes , Artérias , Células Endoteliais , Vírus Hendra/genética , Humanos , Tropismo
2.
Semin Cell Dev Biol ; 155(Pt C): 23-29, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-37202277

RESUMO

The interests in blood endothelial cells arise from their therapeutic potential in vascular repair and regeneration. Our understanding of blood endothelial cells that exist in the circulation has been evolving significantly from the original concept of endothelial progenitor cells. Many studies have uncovered heterogeneities of blood endothelial subtypes where some cells express both endothelial and hematopoietic antigens, and others possess either mature or immature endothelial markers. Due to the lack of definitive cell marker identities, there have been momentums in the field to adopt a technical-oriented labeling system based on the cells' involvement in postnatal neovascularization and cell culture derivatives. Our review streamlines nomenclatures for blood endothelial subtypes and standardizes understanding of their functional differences. Broadly, we will discuss about myeloid angiogenic cells (MACs), endothelial colony-forming cells (ECFCs), blood outgrowth endothelial cells (BOECs) and circulating endothelial cells (CECs). The strategic location of blood endothelial cells confers them essential roles in supporting physiological processes. MACs exert angiogenic effects through paracrine mechanisms, while ECFCs are recruited to sites of vascular injury to participate directly in new vessel formation. BOECs are an in vitro derivative of ECFCs. CECs are shed into the bloodstream from damaged vessels, hence reflective of endothelial dysfunction. With clarity on the functional attributes of blood endothelial subtypes, we present recent advances in their applications in disease modelling, along with serving as biomarkers of vascular tissue homeostasis.


Assuntos
Células Progenitoras Endoteliais , Células Progenitoras Endoteliais/fisiologia , Técnicas de Cultura de Células , Biomarcadores , Neovascularização Fisiológica , Células Cultivadas
3.
Br J Cancer ; 130(11): 1875-1884, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38582811

RESUMO

BACKGROUND: Other than for breast cancer, endocrine therapy has not been highly effective for gynecologic cancers. Endocrine therapy resistance in estrogen receptor positive gynecologic cancers is still poorly understood. In this retrospective study, we examined the estrogen receptor (ER) signaling pathway activities of breast, ovarian, endometrial, and cervical cancers to identify those that may predict endocrine therapy responsiveness. METHODS: Clinical and genomic data of women with breast and gynecological cancers were downloaded from cBioPortal for Cancer Genomics. Estrogen receptor alpha (ESR1) expression level and sample-level pathway enrichment scores (EERES) were calculated to classify patients into four groups (low/high ESR1 and low/high EERES). Correlation between ESR1/EERES score and survival was further validated with RNAseq data from low-grade serous ovarian cancer. Pathway analyses were performed among different ESR1/EERES groups to identify genes that correlate with endocrine resistance, which are validated using Cancer Cell Line Encyclopedia gene expression and Genomics of Drug Sensitivity in Cancer data. RESULTS: We identified a novel combined prognostic value of ESR1 expression and the corresponding estrogen response signaling (EERES score) for breast cancer. The combined prognostic value (ESR1/EERES) may be applicable to other gynecologic cancers. More importantly, we discovered that ER signaling can cross-regulate MEK pathway activation. We identified downstream genes in the MEK pathway (EPHA2, INAVA, MALL, MPZL2, PCDH1, and TNFRSF21) that are potential endocrine therapy response biomarkers. CONCLUSION: This study demonstrated that targeting both the ER and the ER signaling activity related MEK pathway may aid the development of endocrine therapy strategies for personalized medicine.


Assuntos
Receptor alfa de Estrogênio , Humanos , Feminino , Prognóstico , Receptor alfa de Estrogênio/metabolismo , Receptor alfa de Estrogênio/genética , Estudos Retrospectivos , Sistema de Sinalização das MAP Quinases/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Resistencia a Medicamentos Antineoplásicos/genética , Transdução de Sinais , Regulação Neoplásica da Expressão Gênica , Antineoplásicos Hormonais/uso terapêutico , Linhagem Celular Tumoral , Neoplasias dos Genitais Femininos/genética , Neoplasias dos Genitais Femininos/tratamento farmacológico , Neoplasias dos Genitais Femininos/metabolismo , Neoplasias dos Genitais Femininos/patologia , Neoplasias dos Genitais Femininos/mortalidade , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/mortalidade
4.
Hepatology ; 77(1): 213-229, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-35363898

RESUMO

BACKGROUND AND AIMS: Metabolism in the liver is dysregulated in obesity, contributing to various health problems including steatosis and insulin resistance. While the pathogenesis of lipid accumulation has been extensively studied, the protective mechanism against lipid challenge in the liver remains unclear. Here, we report that Src homology 3 domain binding kinase 1 (SBK1) is a regulator of hepatic lipid metabolism and systemic insulin sensitivity in response to obesity. APPROACH AND RESULTS: Enhanced Sbk1 expression was found in the liver of high-fat diet (HFD)-induced obese mice and fatty acid (FA)-challenged hepatocytes. SBK1 knockdown in mouse liver cells augmented FA uptake and lipid accumulation. Similarly, liver-specific SBK1 knockout ( Lsko ) mice displayed more severe hepatosteatosis and higher expression of genes in FA uptake and lipogenesis than the Flox/Flox ( Fl/Fl ) control mice when fed the HFD. The HFD-fed Lsko mice also showed symptoms of hyperglycemia, poor systemic glucose tolerance, and lower insulin sensitivity than the Fl/Fl mice. On the other hand, hepatic Sbk1 overexpression alleviated the high-fructose diet-induced hepatosteatosis, hyperlipidemia, and hyperglycemia in mice. White adipose tissue browning was also observed in hepatic SBK1 -overexpressed mice. Moreover, we found that SBK1 was a positive regulator of FGF21 in the liver during energy surplus conditions. Mechanistically, SBK1 phosphorylates the orphan nuclear receptor 4A1 (Nur77) on serine 344 to promote hepatic FGF21 expression and inhibit the transcription of genes involved in lipid anabolism. CONCLUSIONS: Collectively, our data suggest that SBK1 is a regulator of the metabolic adaption against obesity through the Nur77-FGF21 pathway.


Assuntos
Fígado Gorduroso , Resistência à Insulina , Proteínas Quinases , Animais , Camundongos , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Hiperglicemia/complicações , Hiperglicemia/metabolismo , Hiperglicemia/patologia , Lipídeos , Fígado/patologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Obesidade/complicações , Membro 1 do Grupo A da Subfamília 4 de Receptores Nucleares
5.
EMBO Rep ; 23(6): e54271, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35403791

RESUMO

The top cause of mortality in patients with nonalcoholic fatty liver disease (NAFLD) is cardiovascular complications. However, mechanisms of NAFLD-associated vasculopathy remain understudied. Here, we show that blood outgrowth endothelial cells (BOECs) from NAFLD subjects exhibit global transcriptional upregulation of chemokines and human leukocyte antigens. In mouse models of diet-induced NAFLD, we confirm heightened endothelial expressions of CXCL12 in the aortas and the liver vasculatures, and increased retention of infiltrated leukocytes within the vessel walls. To elucidate endothelial-immune crosstalk, we performed immunoprofiling by single-cell analysis, uncovering T cell intensification in NAFLD patients. Functionally, treatment with a CXCL12-neutralizing antibody is effective at moderating the enhanced chemotactic effect of NAFLD BOECs in recruiting CD8+ T lymphocytes. Interference with the CXCL12-CXCR4 axis using a CXCR4 antagonist also averts the impact of immune cell transendothelial migration and restores endothelial barrier integrity. Clinically, we detect threefold more circulating damaged endothelial cells in NAFLD patients than in healthy controls. Our work provides insight into the modulation of interactions with effector immune cells to mitigate endothelial injury in NAFLD.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Movimento Celular , Células Endoteliais/metabolismo , Humanos , Fígado/metabolismo , Linfócitos/metabolismo , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Transdução de Sinais
6.
Plant Physiol ; 188(1): 442-459, 2022 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-34747472

RESUMO

Chloroplasts are the sites for photosynthesis, and two Golden2-like factors act as transcriptional activators of chloroplast development in rice (Oryza sativa L.) and maize (Zea mays L.). Rice OsGLK1 and OsGLK2 are orthologous to maize ZmGLK1 (ZmG1) and ZmGLK2 (ZmG2), respectively. However, while rice OsGLK1 and OsGLK2 act redundantly to regulate chloroplast development in mesophyll cells, maize ZmG1 and ZmG2 are functionally specialized and expressed in different cell-specific manners. To boost rice chloroplast development and photosynthesis, we generated transgenic rice plants overexpressing ZmG1 and ZmG2, individually or simultaneously, with constitutive promoters (pZmUbi::ZmG1 and p35S::ZmG2) or maize promoters (pZmG1::ZmG1, pZmG2::ZmG2, and pZmG1::ZmG1/pZmG2::ZmG2). Both ZmG1 and ZmG2 genes were highly expressed in transgenic rice leaves. Moreover, ZmG1 and ZmG2 showed coordinated expression in pZmG1::ZmG1/pZmG2::ZmG2 plants. All Golden2-like (GLK) transgenic plants had higher chlorophyll and protein contents, Rubisco activities and photosynthetic rates per unit leaf area in flag leaves. However, the highest grain yields occurred when maize promoters were used; pZmG1::ZmG1, pZmG2::ZmG2, and pZmG1::ZmG1/pZmG2::ZmG2 transgenic plants showed increases in grain yield by 51%, 47%, and 70%, respectively. In contrast, the pZmUbi::ZmG1 plant produced smaller seeds without yield increases. Transcriptome analysis indicated that maize GLKs act as master regulators promoting the expression of both photosynthesis-related and stress-responsive regulatory genes in both rice shoot and root. Thus, by promoting these important functions under the control of their own promoters, maize GLK1 and GLK2 genes together dramatically improved rice photosynthetic performance and productivity. A similar approach can potentially improve the productivity of many other crops.


Assuntos
Cloroplastos/genética , Cloroplastos/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/genética , Fotossíntese/genética , Sementes/crescimento & desenvolvimento , Sementes/genética , Zea mays/genética , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Variação Genética , Genótipo , Fatores de Transcrição/genética
7.
Eur Spine J ; 32(9): 3058-3071, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37256367

RESUMO

PURPOSE: Anterior vertebral body tethering (AVBT) was introduced as a fusionless alternative to treating adolescent idiopathic scoliosis (AIS) while preserving range of motion (ROM). This is the first systematic review to compare the ROM outcomes between AVBT and PSF in treating AIS. METHODS: We conducted a comprehensive search on PubMed, EMBASE, MEDLINE, and Cochrane Library. Inclusion criteria were patients with AIS treated with AVBT or PSF or both, and clearly defined ROM outcomes; exclusion criteria were scoliosis other than AIS, biomechanical or cadaveric studies, non-English publications, case reports, conference summaries, unpublished literature, commentaries, and reviews. Primary outcome was ROM. Secondary outcomes included Cobb angle correction, quality of life (QOL), complications, and muscle strength and endurance. RESULTS: Twelve studies were included in this review. We found moderate evidence to support that AVBT results in superior ROM outcomes than PSF while achieving comparable Cobb angle correction with low evidence. The comparison of QOL outcomes between AVBT and PSF remained inconclusive. In addition to the complications noted conventionally in PSF, AVBT could result in over-correction and distal adding-on. We also found very low evidence to support that AIS patients treated with AVBT have superior muscle strength and endurance when compared to those treated with PSF. CONCLUSIONS: AVBT provides better preservation of ROM and muscle strength postoperatively when compared with PSF, while achieving comparable curve correction. Future studies should explore the spinal growth trajectory to determine the window of opportunity for AVBT in AIS.


Assuntos
Cifose , Escoliose , Fusão Vertebral , Humanos , Adolescente , Escoliose/cirurgia , Qualidade de Vida , Vértebras Torácicas/cirurgia , Corpo Vertebral , Fusão Vertebral/métodos , Resultado do Tratamento , Amplitude de Movimento Articular , Estudos Retrospectivos
8.
BMC Biol ; 20(1): 47, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35164755

RESUMO

BACKGROUND: Polypoidal choroidal vasculopathy (PCV), a subtype of age-related macular degeneration (AMD), is a global leading cause of vision loss in older populations. Distinct from typical AMD, PCV is characterized by polyp-like dilatation of blood vessels and turbulent blood flow in the choroid of the eye. Gold standard anti-vascular endothelial growth factor (anti-VEGF) therapy often fails to regress polypoidal lesions in patients. Current animal models have also been hampered by their inability to recapitulate such vascular lesions. These underscore the need to identify VEGF-independent pathways in PCV pathogenesis. RESULTS: We cultivated blood outgrowth endothelial cells (BOECs) from PCV patients and normal controls to serve as our experimental disease models. When BOECs were exposed to heterogeneous flow, single-cell transcriptomic analysis revealed that PCV BOECs preferentially adopted migratory-angiogenic cell state, while normal BOECs undertook proinflammatory cell state. PCV BOECs also had a repressed protective response to flow stress by demonstrating lower mitochondrial functions. We uncovered that elevated hyaluronidase-1 in PCV BOECs led to increased degradation of hyaluronan, a major component of glycocalyx that interfaces between flow stress and vascular endothelium. Notably, knockdown of hyaluronidase-1 in PCV BOEC improved mechanosensitivity, as demonstrated by a significant 1.5-fold upregulation of Krüppel-like factor 2 (KLF2) expression, a flow-responsive transcription factor. Activation of KLF2 might in turn modulate PCV BOEC migration. Barrier permeability due to glycocalyx impairment in PCV BOECs was also reversed by hyaluronidase-1 knockdown. Correspondingly, hyaluronidase-1 was detected in PCV patient vitreous humor and plasma samples. CONCLUSIONS: Hyaluronidase-1 inhibition could be a potential therapeutic modality in preserving glycocalyx integrity and endothelial stability in ocular diseases with vascular origin.


Assuntos
Hialuronoglucosaminidase , Degeneração Macular , Idoso , Corioide/irrigação sanguínea , Corioide/patologia , Células Endoteliais , Angiofluoresceinografia , Glicocálix/patologia , Humanos , Hialuronoglucosaminidase/genética , Hialuronoglucosaminidase/uso terapêutico , Degeneração Macular/tratamento farmacológico , Degeneração Macular/patologia
9.
J Biol Chem ; 296: 100520, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33684447

RESUMO

The retention of low-density lipoprotein (LDL) is a key process in the pathogenesis of atherosclerosis and largely mediated via smooth-muscle cell-derived extracellular proteoglycans including the glycosaminoglycan chains. Macrophages can also internalize lipids via complexes with proteoglycans. However, the role of polarized macrophage-derived proteoglycans in binding LDL is unknown and important to advance our understanding of the pathogenesis of atherosclerosis. We therefore examined the identity of proteoglycans, including the pendent glycosaminoglycans, produced by polarized macrophages to gain insight into the molecular basis for LDL binding. Using the quartz crystal microbalance with dissipation monitoring technique, we established that classically activated macrophage (M1)- and alternatively activated macrophage (M2)-derived proteoglycans bind LDL via both the protein core and heparan sulfate (HS) in vitro. Among the proteoglycans secreted by macrophages, we found perlecan was the major protein core that bound LDL. In addition, we identified perlecan in the necrotic core as well as the fibrous cap of advanced human atherosclerotic lesions in the same regions as HS and colocalized with M2 macrophages, suggesting a functional role in lipid retention in vivo. These findings suggest that macrophages may contribute to LDL retention in the plaque by the production of proteoglycans; however, their contribution likely depends on both their phenotype within the plaque and the presence of enzymes, such as heparanase, that alter the secreted protein structure.


Assuntos
Aterosclerose/metabolismo , Proteoglicanas de Heparan Sulfato/metabolismo , Heparitina Sulfato/metabolismo , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Aterosclerose/patologia , Células Cultivadas , Humanos , Macrófagos/citologia
10.
J Transl Med ; 20(1): 606, 2022 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-36528667

RESUMO

BACKGROUND: Low-grade serous ovarian cancer (LGSOC) is a rare disease that occurs more frequently in younger women than those with high-grade disease. The current treatment is suboptimal and a better understanding of the molecular pathogenesis of this disease is required. In this study, we compared the proteogenomic analyses of LGSOCs from short- and long-term survivors (defined as < 40 and > 60 months, respectively). Our goal was to identify novel mutations, proteins, and mRNA transcripts that are dysregulated in LGSOC, particularly in short-term survivors. METHODS: Initially, targeted sequencing of 409 cancer-related genes was performed on 22 LGSOC and 6 serous borderline ovarian tumor samples. Subsequently, whole-genome sequencing analysis was performed on 14 LGSOC samples (7 long-term survivors and 7 short-term survivors) with matched normal tissue samples. RNA sequencing (RNA-seq), quantitative proteomics, and phosphoproteomic analyses were also performed. RESULTS: We identified single-nucleotide variants (SNVs) (range: 5688-14,833 per sample), insertion and deletion variants (indels) (range: 880-1065), and regions with copy number variants (CNVs) (range: 62-335) among the 14 LGSOC samples. Among all SNVs and indels, 2637 mutation sites were found in the exonic regions. The allele frequencies of the detected variants were low (median12%). The identified recurrent nonsynonymous missense mutations included KRAS, NRAS, EIF1AX, UBR5, and DNM3 mutations. Mutations in DNM3 and UBR5 have not previously been reported in LGSOC. For the two samples, somatic DNM3 nonsynonymous missense mutations in the exonic region were validated using Sanger sequencing. The third sample contained two missense mutations in the intronic region of DNM3, leading to a frameshift mutation detected in RNA transcripts in the RNA-seq data. Among the 14 LGSOC samples, 7754 proteins and 9733 phosphosites were detected by global proteomic analysis. Some of these proteins and signaling pathways, such as BST1, TBXAS1, MPEG1, HBA1, and phosphorylated ASAP1, are potential therapeutic targets. CONCLUSIONS: This is the first study to use whole-genome sequencing to detect somatic mutations in LGSOCs with matched normal tissues. We detected and validated novel mutations in DNM3, which were present in 3 of the 14 samples analyzed. Additionally, we identified novel indels, regions with CNVs, dysregulated mRNA, dysregulated proteins, and phosphosites that are more prevalent in short-term survivors. This integrated proteogenomic analysis can guide research into the pathogenesis and treatment of LGSOC.


Assuntos
Cistadenocarcinoma Seroso , Dinamina III , Neoplasias Ovarianas , Feminino , Humanos , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/patologia , Dinamina III/genética , Multiômica , Mutação/genética , Gradação de Tumores , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Proteômica , RNA Mensageiro/genética , RNA Mensageiro/uso terapêutico , Sobreviventes
11.
Inflamm Res ; 71(10-11): 1261-1270, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35916930

RESUMO

OBJECTIVES: We employed the co-culture of CD34+ stem cell-derived human mast cells (HMC) and human monocyte-derived osteoclast precursors to evaluate if mast cells contribute to the pathogenesis of osteoporosis through regulation of osteoclast proliferation and activation. METHODS: Mature HMC and osteoclast precursors were cultured from monocytes isolated from human buffy coat. The osteoclast precursors were incubated with HMC or receptor activator of nuclear factor kappa-B ligand (RANKL) for a week prior to determination of osteoclast maturation through characterization by their morphology and tartrate resistant acid phosphatase (TRAP) expression. The bone absorption activity was determined by pit formation on osteo-assay plate. RESULTS: Mature osteoclasts were identified following co-culture of osteoclast precursors with HMC for one week in the absence of RANKL and they were capable of bone resorption. These actions of HMC on osteoclasts were not affected by mast cell activators such anti-IgE or substance P but could be reversed by osteoprotegerin (OPG) in the co-culture system suggesting the involvement of RANKL. The expression of RANKL on the cell surface of HMC was confirmed by flow cytometry and the density was not affected by activation of HMC. CONCLUSION: Our study provided direct evidence confirming the initiation of osteoclast proliferation and activation by mast cells through cell surface RANKL suggesting that mast cells may contribute to bone destruction in pathological conditions such as osteoporosis.


Assuntos
Mastócitos , Osteoporose , Humanos , Diferenciação Celular , Células Cultivadas , Mastócitos/metabolismo , Glicoproteínas de Membrana/metabolismo , NF-kappa B/metabolismo , Osteoclastos , Osteogênese , Osteoporose/metabolismo , Osteoprotegerina/metabolismo , Ligante RANK/metabolismo , Receptor Ativador de Fator Nuclear kappa-B/metabolismo
12.
Int J Mol Sci ; 23(20)2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-36293401

RESUMO

Age-related macular degeneration (AMD) is a global leading cause of visual impairment in older populations. 'Wet' AMD, the most common subtype of this disease, occurs when pathological angiogenesis infiltrates the subretinal space (choroidal neovascularization), causing hemorrhage and retinal damage. Gold standard anti-vascular endothelial growth factor (VEGF) treatment is an effective therapy, but the long-term prevention of visual decline has not been as successful. This warrants the need to elucidate potential VEGF-independent pathways. We generated blood out-growth endothelial cells (BOECs) from wet AMD and normal control subjects, then induced angiogenic sprouting of BOECs using a fibrin gel bead assay. To deconvolute endothelial heterogeneity, we performed single-cell transcriptomic analysis on the sprouting BOECs, revealing a spectrum of cell states. Our wet AMD BOECs share common pathways with choroidal neovascularization such as extracellular matrix remodeling that promoted proangiogenic phenotype, and our 'activated' BOEC subpopulation demonstrated proinflammatory hallmarks, resembling the tip-like cells in vivo. We uncovered new molecular insights that pathological angiogenesis in wet AMD BOECs could also be driven by interleukin signaling and amino acid metabolism. A web-based visualization of the sprouting BOEC single-cell transcriptome has been created to facilitate further discovery research.


Assuntos
Neovascularização de Coroide , Degeneração Macular Exsudativa , Humanos , Neovascularização de Coroide/tratamento farmacológico , Transcriptoma , Fator A de Crescimento do Endotélio Vascular/metabolismo , Células Endoteliais/metabolismo , Degeneração Macular Exsudativa/tratamento farmacológico , Fatores de Crescimento do Endotélio Vascular , Interleucinas/uso terapêutico , Aminoácidos , Fibrina , Inibidores da Angiogênese/uso terapêutico
13.
Plant J ; 97(6): 1073-1088, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30523657

RESUMO

The CS8 transgenic rice (Oryza sativa L.) lines expressing an up-regulated glgC gene produced higher levels of ADPglucose (ADPglc), the substrate for starch synthases. However, the increase in grain weight was much less than the increase in ADPglc levels suggesting one or more downstream rate-limiting steps. Endosperm starch levels were not further enhanced in double transgenic plants expressing both glgC and the maize brittle-1 gene, the latter responsible for transport of ADPglc into the amyloplast. These studies demonstrate that critical processes within the amyloplast stroma restrict maximum carbon flow into starch. RNA-seq analysis showed extensive re-programming of gene expression in the CS8 with 2073 genes up-regulated and 140 down-regulated. One conspicuous gene, up-regulated ~15-fold, coded for a biochemically uncharacterized starch binding domain-containing protein (SBDCP1) possessing a plastid transit peptide. Confocal microscopy and transmission electron microscopy analysis confirmed that SBDCP1 was located in the amyloplasts. Reciprocal immunoprecipitation and pull-down assays indicated an interaction between SBDCP1 and starch synthase IIIa (SSIIIa), which was down-regulated at the protein level in the CS8 line. Furthermore, binding by SBDCP1 inhibited SSIIIa starch polymerization activity in a non-competitive manner. Surprisingly, artificial microRNA gene suppression of SBDCP1 restored protein expression levels of SSIIIa in the CS8 line resulting in starch with lower amylose content and increased amylopectin chains with a higher degree of polymerization. Collectively, our results support the involvement of additional non-enzymatic factors such as SBDCP in starch biosynthesis.


Assuntos
Metabolismo dos Carboidratos , Oryza/enzimologia , Proteínas de Plantas/metabolismo , Amido/biossíntese , Zea mays/genética , Regulação para Baixo , Endosperma/metabolismo , Expressão Gênica , Perfilação da Expressão Gênica , Glucose-1-Fosfato Adenililtransferase/genética , Glucose-1-Fosfato Adenililtransferase/metabolismo , Oryza/genética , Oryza/fisiologia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Plastídeos/metabolismo , Sintase do Amido/genética , Sintase do Amido/metabolismo , Regulação para Cima
14.
Langmuir ; 36(11): 2966-2973, 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32108481

RESUMO

This paper demonstrates the stabilization of single foam films at dynamic conditions induced by exposure to the acoustic sound. The foam films were formed from aqueous solutions using a Sheludko cell. In the presence of sound at certain sound frequencies and above certain thresholds of sound amplitude, the lifetime of the film with 1 × 10-4 M sodium dodecyl sulfate (SDS) in the presence of 0.1 M NaCl was significantly increased, and a stabilization map was drawn to show the three levels of film stability (i.e., unstable, metastable, and stable) obtained over a broad range of sound frequencies (1-19 kHz) and amplitudes (74-125 dB). In particular, stable films were observed at relatively high frequencies (14-19 kHz) and high amplitudes (>107 dB) and metastable films were observed at intermediate frequencies (8.8-9.3 kHz) and high amplitudes (>111 dB). The stabilization effect was also demonstrated with different surfactants at different concentrations, at different electrolyte concentrations (in the presence and absence of the surfactant), and at different temperatures. Image analysis suggested the presence of liquid flow within the films that were stabilized by exposure to the acoustic sound. The stabilization effect could be attributed to the hydrodynamic pressure arising at dynamic conditions.

15.
Langmuir ; 35(36): 11609-11628, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31256589

RESUMO

Metal halide perovskite semiconductor nanocrystals have emerged as a lucrative class of materials for many optoelectronic applications. By leveraging the synthetic toolboxes developed from decades of research into more traditional semiconductor nanocrystals, remarkable progress has been made across these materials in terms of their structural, compositional, and optoelectronic control. Here, we review this progress in terms of their underlying formation stages, synthetic approaches, and postsynthetic treatment steps. This assessment highlights the rapidly maturing nature of the perovskite nanocrystal field, particularly with regard to their lead-based derivatives. It further demonstrates that significant challenges remain around precisely controlling their nucleation and growth processes. In going forward, a deeper understanding of the role of precursors and ligands will significantly bolster the versatility in the size, shape, composition, and functional properties of these exciting materials.

18.
Int Arch Allergy Immunol ; 177(3): 199-206, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30021208

RESUMO

BACKGROUND: Mast cells are key immune effector cells which release chemokines, proteases, and other inflammatory mediators upon activation by immunological stimuli. The aim of this study was to investigate the effects of co-releasing proteases on the kinetics of release of the chemokine monocyte chemoattractant protein-1 (MCP-1) in immunoglobulin E (IgE)-mediated activation of human mast cells. METHODS: Homogenous populations of mature and functional primary human mast cells were generated from CD34+ progenitors originated from buffy coats of healthy adult donors. The releases of MCP-1 from human mast cells in basal conditions and in response to FcεRI cross-linking were assessed at different time points. The effects of different types of protease inhibitors on MCP-1 release from these mast cells under stimulated or unstimulated conditions were also investigated. RESULTS: Cultured human mast cells released MCP-1 in basal conditions and its levels increased in a time-dependent manner. When stimulated by FcεRI cross-linking, the levels of MCP-1 detected in the medium gradually decreased over time after the initial peak induction. Such a decline in MCP-1 levels after IgE-dependent activation was completely prevented by pretreatment with a cocktail of protease inhibitors or the specific tryptase inhibitor APC366. CONCLUSIONS: Direct regulation of MCP-1 expression by co-release of tryptase in cultured human mast cells upon IgE-dependent activation demonstrates a role of the serglycin:serine protease axis in modulation of inflammatory reactions through proteolytic degradation of mediators such as chemokines.


Assuntos
Quimiocina CCL2/metabolismo , Imunoglobulina E/imunologia , Mastócitos/imunologia , Proteoglicanas/metabolismo , Serina Proteases/metabolismo , Triptases/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Degranulação Celular/imunologia , Células Cultivadas , Liberação de Histamina/imunologia , Humanos , Mastócitos/fisiologia , Inibidores de Proteases/farmacologia , Receptores de IgE/imunologia , Receptores de IgE/metabolismo , Triptases/antagonistas & inibidores
20.
Angew Chem Int Ed Engl ; 57(18): 4986-4990, 2018 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-29498164

RESUMO

Construction of single-component supramolecular triangle and unprecedented spontaneous resolution of pairs of intertwined supramolecular 31 - and 32 -double helices by the self-assembly of achiral 2-(iodoethynyl)pyridine and its derivatives have been achieved through intermolecular ethynyl C-I⋅⋅⋅⋅N halogen bonds in the crystalline state. Fine-tuning of the molecular structure of the achiral monomer and choice of solvents for crystallization have a dominant effect on the resultant supramolecular architectures.

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