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1.
Cell ; 187(7): 1685-1700.e18, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38503280

RESUMO

The reciprocal coordination between cholesterol absorption in the intestine and de novo cholesterol synthesis in the liver is essential for maintaining cholesterol homeostasis, yet the mechanisms governing the opposing regulation of these processes remain poorly understood. Here, we identify a hormone, Cholesin, which is capable of inhibiting cholesterol synthesis in the liver, leading to a reduction in circulating cholesterol levels. Cholesin is encoded by a gene with a previously unknown function (C7orf50 in humans; 3110082I17Rik in mice). It is secreted from the intestine in response to cholesterol absorption and binds to GPR146, an orphan G-protein-coupled receptor, exerting antagonistic downstream effects by inhibiting PKA signaling and thereby suppressing SREBP2-controlled cholesterol synthesis in the liver. Therefore, our results demonstrate that the Cholesin-GPR146 axis mediates the inhibitory effect of intestinal cholesterol absorption on hepatic cholesterol synthesis. This discovered hormone, Cholesin, holds promise as an effective agent in combating hypercholesterolemia and atherosclerosis.


Assuntos
Colesterol , Hormônios , Proteínas de Ligação a RNA , Animais , Humanos , Camundongos , Colesterol/metabolismo , Hormônios/genética , Hormônios/metabolismo , Hipercolesterolemia/metabolismo , Fígado/metabolismo , Transdução de Sinais , Proteínas de Ligação a RNA/metabolismo
2.
Nature ; 630(8015): 222-229, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38657677

RESUMO

Gamma delta (γδ) T cells, a unique T cell subgroup, are crucial in various immune responses and immunopathology1-3. The γδ T cell receptor (TCR), which is generated by γδ T cells, recognizes a diverse range of antigens independently of the major histocompatibility complex2. The γδ TCR associates with CD3 subunits, initiating T cell activation and holding great potential in immunotherapy4. Here we report the structures of two prototypical human Vγ9Vδ2 and Vγ5Vδ1 TCR-CD3 complexes5,6, revealing two distinct assembly mechanisms that depend on Vγ usage. The Vγ9Vδ2 TCR-CD3 complex is monomeric, with considerable conformational flexibility in the TCRγ-TCRδ extracellular domain and connecting peptides. The length of the connecting peptides regulates the ligand association and T cell activation. A cholesterol-like molecule wedges into the transmembrane region, exerting an inhibitory role in TCR signalling. The Vγ5Vδ1 TCR-CD3 complex displays a dimeric architecture, whereby two protomers nestle back to back through the Vγ5 domains of the TCR extracellular domains. Our biochemical and biophysical assays further corroborate the dimeric structure. Importantly, the dimeric form of the Vγ5Vδ1 TCR is essential for T cell activation. These findings reveal organizing principles of the γδ TCR-CD3 complex, providing insights into the unique properties of γδ TCR and facilitating immunotherapeutic interventions.


Assuntos
Complexo CD3 , Receptores de Antígenos de Linfócitos T gama-delta , Linfócitos T , Humanos , Complexo CD3/química , Complexo CD3/imunologia , Complexo CD3/metabolismo , Complexo CD3/ultraestrutura , Colesterol/metabolismo , Colesterol/química , Microscopia Crioeletrônica , Ligantes , Ativação Linfocitária/imunologia , Modelos Moleculares , Domínios Proteicos , Multimerização Proteica , Receptores de Antígenos de Linfócitos T gama-delta/química , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Receptores de Antígenos de Linfócitos T gama-delta/ultraestrutura , Linfócitos T/química , Linfócitos T/citologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Transdução de Sinais , Membrana Celular/química , Membrana Celular/metabolismo
3.
Nature ; 624(7991): 333-342, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38092915

RESUMO

The function of the mammalian brain relies upon the specification and spatial positioning of diversely specialized cell types. Yet, the molecular identities of the cell types and their positions within individual anatomical structures remain incompletely known. To construct a comprehensive atlas of cell types in each brain structure, we paired high-throughput single-nucleus RNA sequencing with Slide-seq1,2-a recently developed spatial transcriptomics method with near-cellular resolution-across the entire mouse brain. Integration of these datasets revealed the cell type composition of each neuroanatomical structure. Cell type diversity was found to be remarkably high in the midbrain, hindbrain and hypothalamus, with most clusters requiring a combination of at least three discrete gene expression markers to uniquely define them. Using these data, we developed a framework for genetically accessing each cell type, comprehensively characterized neuropeptide and neurotransmitter signalling, elucidated region-specific specializations in activity-regulated gene expression and ascertained the heritability enrichment of neurological and psychiatric phenotypes. These data, available as an online resource ( www.BrainCellData.org ), should find diverse applications across neuroscience, including the construction of new genetic tools and the prioritization of specific cell types and circuits in the study of brain diseases.


Assuntos
Encéfalo , Perfilação da Expressão Gênica , Animais , Camundongos , Encéfalo/anatomia & histologia , Encéfalo/citologia , Encéfalo/metabolismo , Perfilação da Expressão Gênica/métodos , Sequenciamento de Nucleotídeos em Larga Escala , Hipotálamo/citologia , Hipotálamo/metabolismo , Mesencéfalo/citologia , Mesencéfalo/metabolismo , Neuropeptídeos/metabolismo , Neurotransmissores/metabolismo , Fenótipo , Rombencéfalo/citologia , Rombencéfalo/metabolismo , Análise da Expressão Gênica de Célula Única , Transcriptoma/genética
4.
Nature ; 611(7935): 284-288, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36289341

RESUMO

Single-atom catalysts1 make exceptionally efficient use of expensive noble metals and can bring out unique properties1-3. However, applications are usually compromised by limited catalyst stability, which is due to sintering3,4. Although sintering can be suppressed by anchoring the metal atoms to oxide supports1,5,6, strong metal-oxygen interactions often leave too few metal sites available for reactant binding and catalysis6,7, and when exposed to reducing conditions at sufficiently high temperatures, even oxide-anchored single-atom catalysts eventually sinter4,8,9. Here we show that the beneficial effects of anchoring can be enhanced by confining the atomically dispersed metal atoms on oxide nanoclusters or 'nanoglues', which themselves are dispersed and immobilized on a robust, high-surface-area support. We demonstrate the strategy by grafting isolated and defective CeOx nanoglue islands onto high-surface-area SiO2; the nanoglue islands then each host on average one Pt atom. We find that the Pt atoms remain dispersed under both oxidizing and reducing environments at high temperatures, and that the activated catalyst exhibits markedly increased activity for CO oxidation. We attribute the improved stability under reducing conditions to the support structure and the much stronger affinity of Pt atoms for CeOx than for SiO2, which ensures the Pt atoms can move but remain confined to their respective nanoglue islands. The strategy of using functional nanoglues to confine atomically dispersed metals and simultaneously enhance their reactivity is general, and we anticipate that it will take single-atom catalysts a step closer to practical applications.

5.
EMBO J ; 42(4): e112184, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36588499

RESUMO

Hippo signaling restricts tumor growth by inhibiting the oncogenic potential of YAP/TAZ-TEAD transcriptional complex. Here, we uncover a context-dependent tumor suppressor function of YAP in androgen receptor (AR) positive prostate cancer (PCa) and show that YAP impedes AR+ PCa growth by antagonizing TEAD-mediated AR signaling. TEAD forms a complex with AR to enhance its promoter/enhancer occupancy and transcriptional activity. YAP and AR compete for TEAD binding and consequently, elevated YAP in the nucleus disrupts AR-TEAD interaction and prevents TEAD from promoting AR signaling. Pharmacological inhibition of MST1/2 or LATS1/2, or transgenic activation of YAP suppressed the growth of PCa expressing therapy resistant AR splicing variants. Our study uncovers an unanticipated crosstalk between Hippo and AR signaling pathways, reveals an antagonistic relationship between YAP and TEAD in AR+ PCa, and suggests that targeting the Hippo signaling pathway may provide a therapeutical opportunity to treat PCa driven by therapy resistant AR variants.


Assuntos
Neoplasias da Próstata , Fatores de Transcrição , Masculino , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Sinalização YAP , Transdução de Sinais , Neoplasias da Próstata/genética
6.
EMBO J ; 42(17): e113415, 2023 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-37485728

RESUMO

The human ABC transporter ABCC3 (also known as MRP3) transports a wide spectrum of substrates, including endogenous metabolites and exogenous drugs. Accordingly, it participates in multiple physiological processes and is involved in diverse human diseases such as intrahepatic cholestasis of pregnancy, which is caused by the intracellular accumulation of bile acids and estrogens. Here, we report three cryogenic electron microscopy structures of ABCC3: in the apo-form and in complexed forms bound to either the conjugated sex hormones ß-estradiol 17-(ß-D-glucuronide) and dehydroepiandrosterone sulfate. For both hormones, the steroid nuclei that superimpose against each other occupy the hydrophobic center of the transport cavity, whereas the two conjugation groups are separated and fixed by the hydrophilic patches in two transmembrane domains. Structural analysis combined with site-directed mutagenesis and ATPase activity assays revealed that ABCC3 possesses an amphiphilic substrate-binding pocket able to hold either conjugated hormone in an asymmetric pattern. These data build on consensus features of the substrate-binding pocket of MRPs and provide a structural platform for the rational design of inhibitors.


Assuntos
Transportadores de Cassetes de Ligação de ATP , Estradiol , Humanos , Transportadores de Cassetes de Ligação de ATP/genética , Estradiol/farmacologia , Estradiol/metabolismo , Mutagênese Sítio-Dirigida
7.
Nature ; 598(7879): 159-166, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34616071

RESUMO

An essential step toward understanding brain function is to establish a structural framework with cellular resolution on which multi-scale datasets spanning molecules, cells, circuits and systems can be integrated and interpreted1. Here, as part of the collaborative Brain Initiative Cell Census Network (BICCN), we derive a comprehensive cell type-based anatomical description of one exemplar brain structure, the mouse primary motor cortex, upper limb area (MOp-ul). Using genetic and viral labelling, barcoded anatomy resolved by sequencing, single-neuron reconstruction, whole-brain imaging and cloud-based neuroinformatics tools, we delineated the MOp-ul in 3D and refined its sublaminar organization. We defined around two dozen projection neuron types in the MOp-ul and derived an input-output wiring diagram, which will facilitate future analyses of motor control circuitry across molecular, cellular and system levels. This work provides a roadmap towards a comprehensive cellular-resolution description of mammalian brain architecture.


Assuntos
Córtex Motor/anatomia & histologia , Córtex Motor/citologia , Neurônios/classificação , Animais , Atlas como Assunto , Feminino , Neurônios GABAérgicos/citologia , Neurônios GABAérgicos/metabolismo , Glutamatos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neuroimagem , Neurônios/citologia , Neurônios/metabolismo , Especificidade de Órgãos , Análise de Sequência de RNA , Análise de Célula Única
8.
Plant Cell ; 35(5): 1304-1317, 2023 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-36724050

RESUMO

Although many studies have elucidated the mechanisms by which different wavelengths of light (blue, red, far-red, or ultraviolet-B [UV-B]) regulate plant development, whether and how green light regulates plant development remains largely unknown. Previous studies reported that green light participates in regulating growth and development in land plants, but these studies have reported conflicting results, likely due to technical problems. For example, commercial green light-emitting diode light sources emit a little blue or red light. Here, using a pure green light source, we determined that unlike blue, red, far-red, or UV-B light, which inhibits hypocotyl elongation, green light promotes hypocotyl elongation in Arabidopsis thaliana and several other plants during the first 2-3 d after planting. Phytochromes, cryptochromes, and other known photoreceptors do not mediate green-light-promoted hypocotyl elongation, but the brassinosteroid (BR) signaling pathway is involved in this process. Green light promotes the DNA binding activity of BRI1-EMS-SUPPRESSOR 1 (BES1), a master transcription factor of the BR pathway, thus regulating gene transcription to promote hypocotyl elongation. Our results indicate that pure green light promotes elongation via BR signaling and acts as a shade signal to enable plants to adapt their development to a green-light-dominant environment under a canopy.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Proteínas de Arabidopsis/metabolismo , Hipocótilo , Brassinosteroides/metabolismo , Arabidopsis/metabolismo , Transdução de Sinais , Regulação da Expressão Gênica de Plantas
9.
EMBO Rep ; 25(1): 378-403, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38177901

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is mainly characterized by excessive fat accumulation in the liver, and it is associated with liver-related complications and adverse systemic diseases. NAFLD has become the most prevalent liver disease; however, effective therapeutic agents for NAFLD are still lacking. We combined clinical data with proteomics and metabolomics data, and found that the mitochondrial nucleoside diphosphate kinase NME4 plays a central role in mitochondrial lipid metabolism. Nme4 is markedly upregulated in mice fed with high-fat diet, and its expression is positively correlated with the level of steatosis. Hepatic deletion of Nme4 suppresses the progression of hepatic steatosis. Further studies demonstrated that NME4 interacts with several key enzymes in coenzyme A (CoA) metabolism and increases the level of acetyl-CoA and malonyl-CoA, which are the major lipid components of the liver in NAFLD. Increased level of acetyl-CoA and malonyl-CoA  lead to increased triglyceride levels and lipid accumulation in the liver. Taken together, these findings reveal that NME4 is a critical regulator of NAFLD progression and a potential therapeutic target for NAFLD.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Acetilcoenzima A/metabolismo , Reprogramação Metabólica , Fígado/metabolismo , Metabolismo dos Lipídeos/genética , Dieta Hiperlipídica/efeitos adversos , Lipídeos , Camundongos Endogâmicos C57BL
10.
Proc Natl Acad Sci U S A ; 120(3): e2208927120, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36626550

RESUMO

The process of oncogene-induced senescence (OIS) and the conversion between OIS and malignant transformation during carcinogenesis is poorly understood. Here, we show that following overactivation of oncogene Ras in lung epithelial cells, high-level transforming growth factor ß1 (TGF-ß1)-activated SMAD3, but not SMAD2 or SMAD4, plays a determinant role in inducing cellular senescence independent of the p53/p16/p15 senescence pathways. Importantly, SMAD3 binds a potential tumor suppressor ATOH8 to form a transcriptional complex that directly represses a series of cell cycle-promoting genes and consequently causes senescence in lung epithelial cells. Interestingly, the prosenescent SMAD3 converts to being oncogenic and essentially facilitates oncogenic Ras-driven malignant transformation. Furthermore, depleting Atoh8 rapidly accelerates oncogenic Ras-driven lung tumorigenesis, and lung cancers driven by mutant Ras and Atoh8 loss, but not by mutant Ras only, are sensitive to treatment of a specific SMAD3 inhibitor. Moreover, hypermethylation of the ATOH8 gene can be found in approximately 12% of clinical lung cancer cases. Together, our findings demonstrate not only epithelial cellular senescence directed by a potential tumor suppressor-controlled transcriptional program but also an important interplay between the prosenescent and transforming effects of TGF-ß/SMAD3, potentially laying a foundation for developing early detection and anticancer strategies.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos , Transformação Celular Neoplásica , Genes ras , Proteína Smad3 , Humanos , Transformação Celular Neoplásica/genética , Senescência Celular/genética , Genes Supressores de Tumor , Proteína Smad3/genética , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo
11.
Proc Natl Acad Sci U S A ; 120(8): e2206694120, 2023 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-36795754

RESUMO

Notch has been implicated in human cancers and is a putative therapeutic target. However, the regulation of Notch activation in the nucleus remains largely uncharacterized. Therefore, characterizing the detailed mechanisms governing Notch degradation will identify attractive strategies for treating Notch-activated cancers. Here, we report that the long noncoding RNA (lncRNA) BREA2 drives breast cancer metastasis by stabilizing the Notch1 intracellular domain (NICD1). Moreover, we reveal WW domain containing E3 ubiquitin protein ligase 2 (WWP2) as an E3 ligase for NICD1 at K1821 and a suppressor of breast cancer metastasis. Mechanistically, BREA2 impairs WWP2-NICD1 complex formation and in turn stabilizes NICD1, leading to Notch signaling activation and lung metastasis. BREA2 loss sensitizes breast cancer cells to inhibition of Notch signaling and suppresses the growth of breast cancer patient-derived xenograft tumors, highlighting its therapeutic potential in breast cancer. Taken together, these results reveal the lncRNA BREA2 as a putative regulator of Notch signaling and an oncogenic player driving breast cancer metastasis.


Assuntos
Neoplasias da Mama , Neoplasias Pulmonares , RNA Longo não Codificante , Humanos , Feminino , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Ubiquitinação , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Neoplasias Pulmonares/genética , Neoplasias da Mama/genética , Receptor Notch1/genética , Receptor Notch1/metabolismo
12.
J Biol Chem ; 300(6): 107319, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38677512

RESUMO

Lipid metabolism is important for the maintenance of physiological homeostasis. Several members of the small ubiquitin-like modifier (SUMO)-specific protease (SENP) family have been reported as the regulators of lipid homeostasis. However, the function of Senp7 in lipid metabolism remains unclear. In this study, we generated both conventional and adipocyte-specific Senp7 KO mice to characterize the role of Senp7 in lipid metabolism homeostasis. Both Senp7-deficient mice displayed reduced white adipose tissue mass and decreased size of adipocytes. By analyzing the lipid droplet morphology, we demonstrated that the lipid droplet size was significantly smaller in Senp7-deficient adipocytes. Mechanistically, Senp7 could deSUMOylate the perilipin family protein Plin4 to promote the lipid droplet localization of Plin4. Our results reveal an important role of Senp7 in the maturation of lipid droplets via Plin4 deSUMOylation.

13.
Plant Physiol ; 194(2): 787-804, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-37815230

RESUMO

Root development influences plant responses to environmental conditions, and well-developed rooting enhances plant survival under abiotic stress. However, the molecular and genetic mechanisms underlying root development and abiotic stress tolerance in plants remain unclear. In this study, we identified the MYB transcription factor-encoding gene IbMYB73 by cDNA-amplified fragment length polymorphism and RNA-seq analyses. IbMYB73 expression was greatly suppressed under abiotic stress in the roots of the salt-tolerant sweet potato (Ipomoea batatas) line ND98, and its promoter activity in roots was significantly reduced by abscisic acid (ABA), NaCl, and mannitol treatments. Overexpression of IbMYB73 significantly inhibited adventitious root growth and abiotic stress tolerance, whereas IbMYB73-RNAi plants displayed the opposite pattern. IbMYB73 influenced the transcription of genes involved in the ABA pathway. Furthermore, IbMYB73 formed homodimers and activated the transcription of ABA-responsive protein IbGER5 by binding to an MYB binding sites I motif in its promoter. IbGER5 overexpression significantly inhibited adventitious root growth and abiotic stress tolerance concomitantly with a reduction in ABA content, while IbGER5-RNAi plants showed the opposite effect. Collectively, our results demonstrated that the IbMYB73-IbGER5 module regulates ABA-dependent adventitious root growth and abiotic stress tolerance in sweet potato, which provides candidate genes for the development of elite crop varieties with well-developed root-mediated abiotic stress tolerance.


Assuntos
Ácido Abscísico , Ipomoea batatas , Ácido Abscísico/farmacologia , Ácido Abscísico/metabolismo , Ipomoea batatas/genética , Ipomoea batatas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Estresse Fisiológico/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
14.
Plant Cell ; 34(3): 955-966, 2022 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-34904672

RESUMO

Light and temperature change constantly under natural conditions and profoundly affect plant growth and development. Light and warmer temperatures promote flowering, higher light intensity inhibits hypocotyl and petiole elongation, and warmer temperatures promote hypocotyl and petiole elongation. Moreover, exogenous light and temperature signals must be integrated with endogenous signals to fine-tune phytohormone metabolism and plant morphology. Plants perceive and respond to light and ambient temperature using common sets of factors, such as photoreceptors and multiple light signal transduction components. These highly structured signaling networks are critical for plant survival and adaptation. This review discusses how plants respond to variable light and temperature conditions using common elements to coordinate their development. Future directions for research on light and temperature signaling pathways are also discussed.


Assuntos
Proteínas de Arabidopsis , Hipocótilo , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica de Plantas , Luz , Desenvolvimento Vegetal/genética , Plantas/genética , Plantas/metabolismo , Temperatura
15.
FASEB J ; 38(2): e23387, 2024 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-38193649

RESUMO

Human brain microvascular endothelial cells (HBMVECs) and microglia play critical roles in regulating cerebral homeostasis during ischemic stroke. However, the role of HBMVECs-derived exosomes in microglia polarization after stroke remains unknown. We isolated exosomes (Exos) from oxygen glucose deprivation (OGD)-exposed HBMVECs, before added them into microglia. Microglia polarization markers were tested using RT-qPCR or flow cytometry. Inflammatory cytokines were measured with ELISA. Endothelial cell damage was assessed by cell viability, apoptosis, apoptosis-related proteins, oxidative stress, and angiogenic activity using CCK-8, flow cytometry, western blot, ELISA, and endothelial tube formation assay, respectively. We also established middle cerebral artery occlusion (MCAO) mice model to examine the function of circ_0000495 on stroke in vivo. Our study found that HBMVECs-Exos reduced M2 markers (IL-10, CD163, and CD206), increased M1 markers (TNF-α, IL-1ß, and IL-12), CD86-positive cells, and inflammatory cytokines (TNF-α and IL-1ß), indicating the promotion of microglial M1-polarization. Microglial M1-polarization induced by HBMVECs-Exos reduced viability and promoted apoptosis and oxidative stress, revealing the aggravation of endothelial cell damage. However, circ_0000495 silencing inhibited HBMVECs-Exos-induced alterations. Mechanistically, circ_0000495 adsorbed miR-579-3p to upregulate toll-like receptor 4 (TLR4) in microglia; miR-579-3p suppressed HBMVECs-Exos-induced alterations via declining TLR4; furthermore, Yin Yang 1 (YY1) transcriptionally activated circ_0000495 in HBMVECs. Importantly, circ_0000495 aggravated ischemic brain injury in vivo via activating TLR4/nuclear factor-κB (NF-κB) pathway. Collectively, OGD-treated HBMVECs-Exos transmitted circ_0000495 to regulate miR-579-3p/TLR4/NF-κB axis in microglia, thereby facilitating microglial M1-polarization and endothelial cell damage.


Assuntos
Exossomos , MicroRNAs , Acidente Vascular Cerebral , Animais , Camundongos , Humanos , Células Endoteliais , Microglia , Receptor 4 Toll-Like/genética , NF-kappa B , Fator de Necrose Tumoral alfa , Encéfalo , Hipóxia , Oxigênio , Citocinas , MicroRNAs/genética
16.
Mol Psychiatry ; 2024 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-38503925

RESUMO

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social interactions, communication deficits and repetitive behaviors. A study of autistic human subjects has identified RFWD2 as a susceptibility gene for autism, and autistic patients have 3 copies of the RFWD2 gene. The role of RFWD2 as an E3 ligase in neuronal functions, and its contribution to the pathophysiology of ASD, remain unknown. We generated RFWD2 knockin mice to model the human autistic condition of high gene dosage of RFWD2. We found that heterozygous knockin (Rfwd2+/-) male mice exhibited the core symptoms of autism. Rfwd2+/- male mice showed deficits in social interaction and communication, increased repetitive and anxiety-like behavior, and spatial memory deficits, whereas Rfwd2+/- female mice showed subtle deficits in social communication and spatial memory but were normal in anxiety-like, repetitive, and social behaviors. These autistic-like behaviors in males were accompanied by a reduction in dendritic spine density and abnormal synaptic function on layer II/III pyramidal neurons in the prelimbic area of the medial prefrontal cortex (mPFC), as well as decreased expression of synaptic proteins. Impaired social behaviors in Rfwd2+/- male mice were rescued by the expression of ETV5, one of the major substrates of RFWD2, in the mPFC. These findings indicate an important role of RFWD2 in the pathogenesis of autism.

17.
Exp Cell Res ; 438(1): 114049, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38642790

RESUMO

BACKGROUND: Acellular nerve allografts (ANAs) have been successfully applied to bridge facial nerve defects, and transplantation of stem cells may enhance the regenerative results. Up to now, application of hair follicle epidermal neural crest stem cell-derived Schwann cell-like cells (EPI-NCSC-SCLCs) combined with ANAs for bridging facial nerve defects has not been reported. METHODS: The effect of ANAs laden with green fluorescent protein (GFP)-labeled EPI-NCSC-SCLCs (ANA + cells) on bridging rat facial nerve trunk defects (5-mm-long) was detected by functional and morphological examination, as compared with autografts and ANAs, respectively. RESULTS: (1) EPI-NCSC-SCLCs had good compatibility with ANAs in vitro. (2) In the ANA + cells group, the GFP signals were observed by in vivo imaging system for small animals within 8 weeks, and GFP-labeled EPI-NCSC-SCLCs were detected in the tissue slices at 16 weeks postoperatively. (3) The facial symmetry at rest after surgery in the ANA + cells group was better than that in the ANA group (p < 0.05), and similar to that in the autograft group (p > 0.05). The initial recovery time of vibrissal and eyelid movement in the ANA group was 2 weeks later than that in the other two groups. (4) The myelinated fibers, myelin sheath thickness and diameter of the axons of the buccal branches in the ANA group were significantly worse than those in the other two groups (P < 0.05), and the results in the ANA + cells group were similar to those in the autograft group (p > 0.05). CONCLUSIONS: EPI-NCSC-SCLCs could promote functional and morphological recovery of rat facial nerve defects, and GFP labeling could track the transplanted EPI-NCSC-SCLCs in vivo for a certain period of time. These may provide a novel choice for clinical treatment of peripheral nerve defects.


Assuntos
Aloenxertos , Nervo Facial , Proteínas de Fluorescência Verde , Folículo Piloso , Regeneração Nervosa , Crista Neural , Células de Schwann , Animais , Células de Schwann/transplante , Folículo Piloso/transplante , Folículo Piloso/citologia , Crista Neural/citologia , Crista Neural/transplante , Ratos , Proteínas de Fluorescência Verde/metabolismo , Proteínas de Fluorescência Verde/genética , Regeneração Nervosa/fisiologia , Células-Tronco Neurais/transplante , Células-Tronco Neurais/citologia , Ratos Sprague-Dawley , Traumatismos do Nervo Facial/terapia , Traumatismos do Nervo Facial/patologia , Traumatismos do Nervo Facial/cirurgia , Masculino
18.
Proc Natl Acad Sci U S A ; 119(42): e2202133119, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36215479

RESUMO

Unfolded protein response (UPR) is the mechanism by which cells control endoplasmic reticulum (ER) protein homeostasis. ER proteostasis is essential to adapt to cell proliferation and regeneration in development and tumorigenesis, but mechanisms linking UPR, growth control, and cancer progression remain unclear. Here, we report that the Ire1/Xbp1s pathway has surprisingly oncogenic and tumor-suppressive roles in a context-dependent manner. Activation of Ire1/Xbp1s up-regulates their downstream target Bip, which sequesters Yorkie (Yki), a Hippo pathway transducer, in the cytoplasm to restrict Yki transcriptional output. This regulation provides an endogenous defensive mechanism in organ size control, intestinal homeostasis, and regeneration. Unexpectedly, Xbp1 ablation promotes tumor overgrowth but suppresses invasiveness in a Drosophila cancer model. Mechanistically, hyperactivated Ire1/Xbp1s signaling in turn induces JNK-dependent developmental and oncogenic cell migration and epithelial-mesenchymal transition (EMT) via repression of Yki. In humans, a negative correlation between XBP1 and YAP (Yki ortholog) target gene expression specifically exists in triple-negative breast cancers (TNBCs), and those with high XBP1 or HSPA5 (Bip ortholog) expression have better clinical outcomes. In human TNBC cell lines and xenograft models, ectopic XBP1s or HSPA5 expression alleviates tumor growth but aggravates cell migration and invasion. These findings uncover a conserved crosstalk between the Ire1/Xbp1s and Hippo signaling pathways under physiological settings, as well as a crucial role of Bip-Yki interaction in tumorigenesis that is shared from Drosophila to humans.


Assuntos
Proteínas de Drosophila , Proteínas Serina-Treonina Quinases , Animais , Carcinogênese/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Retículo Endoplasmático/metabolismo , Endorribonucleases , Via de Sinalização Hippo , Humanos , Proteínas Serina-Treonina Quinases/genética , Resposta a Proteínas não Dobradas , Proteína 1 de Ligação a X-Box/genética , Proteína 1 de Ligação a X-Box/metabolismo
19.
Proc Natl Acad Sci U S A ; 119(34): e2208759119, 2022 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-35969741

RESUMO

Cytoplasmic male sterility (CMS) determined by mitochondrial genes and restorer of fertility (Rf) controlled by nuclear-encoded genes provide the breeding systems of many hybrid crops for the utilization of heterosis. Although several CMS/Rf systems have been widely exploited in rice, hybrid breeding using these systems has encountered difficulties due to either fertility instability or complications of two-locus inheritance or both. In this work, we characterized a type of CMS, Fujian Abortive cytoplasmic male sterility (CMS-FA), with stable sporophytic male sterility and a nuclear restorer gene that completely restores hybrid fertility. CMS is caused by the chimeric open reading frame FA182 that specifically occurs in the mitochondrial genome of CMS-FA rice. The restorer gene OsRf19 encodes a pentatricopeptide repeat (PPR) protein targeted to mitochondria, where it mediates the cleavage of FA182 transcripts, thus restoring male fertility. Comparative sequence analysis revealed that OsRf19 originated through a recent duplication in wild rice relatives, sharing a common ancestor with OsRf1a/OsRf5, a fertility restorer gene for Boro II and Hong-Lian CMS. We developed six restorer lines by introgressing OsRf19 into parental lines of elite CMS-WA hybrids; hybrids produced from these lines showed equivalent or better agronomic performance relative to their counterparts based on the CMS-WA system. These results demonstrate that CMS-FA/OsRf19 provides a highly promising system for future hybrid rice breeding.


Assuntos
Oryza , Infertilidade das Plantas , Hibridização Genética , Oryza/genética , Oryza/metabolismo , Melhoramento Vegetal , Proteínas de Plantas/metabolismo
20.
Nano Lett ; 24(6): 1851-1858, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38315876

RESUMO

Interlayer excitons, with prolonged lifetimes and tunability, hold potential for advanced optoelectronics. Previous research on the interlayer excitons has been dominated by two-dimensional heterostructures. Here, we construct WSe2/GaN composite heterostructures, in which the doping concentration of GaN and the twist angle of bilayer WSe2 are employed as two ingredients for the manipulation of exciton behaviors and polarizations. The exciton energies in monolayer WSe2/GaN can be regulated continuously by the doping levels of the GaN substrate, and a remarkable increase in the valley polarizations is achieved. Especially in a heterostructure with 4°-twisted bilayer WSe2, a maximum polarization of 38.9% with a long lifetime is achieved for the interlayer exciton. Theoretical calculations reveal that the large polarization and long lifetime are attributed to the high exciton binding energy and large spin flipping energy during depolarization in bilayer WSe2/GaN. This work introduces a distinctive member of the interlayer exciton with a high degree of polarization and a long lifetime.

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