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1.
Nat Immunol ; 19(9): 932-941, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30127433

RESUMEN

Cohesin is important for 3D genome organization. Nevertheless, even the complete removal of cohesin has surprisingly little impact on steady-state gene transcription and enhancer activity. Here we show that cohesin is required for the core transcriptional response of primary macrophages to microbial signals, and for inducible enhancer activity that underpins inflammatory gene expression. Consistent with a role for inflammatory signals in promoting myeloid differentiation of hematopoietic stem and progenitor cells (HPSCs), cohesin mutations in HSPCs led to reduced inflammatory gene expression and increased resistance to differentiation-inducing inflammatory stimuli. These findings uncover an unexpected dependence of inducible gene expression on cohesin, link cohesin with myeloid differentiation, and may help explain the prevalence of cohesin mutations in human acute myeloid leukemia.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Diferenciación Celular/genética , Autorrenovación de las Células/genética , Proteínas Cromosómicas no Histona/metabolismo , Células Madre Hematopoyéticas/fisiología , Leucemia Mieloide Aguda/genética , Macrófagos/fisiología , Proteínas Nucleares/genética , Fosfoproteínas/genética , Animales , Proteínas de Ciclo Celular/genética , Células Cultivadas , Proteínas Cromosómicas no Histona/genética , Proteínas de Unión al ADN , Regulación de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Inflamación/genética , Lipopolisacáridos/inmunología , Ratones , Ratones Noqueados , Mutación/genética , Cohesinas
2.
Nature ; 621(7980): 821-829, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37586410

RESUMEN

Endothelial cells line the blood and lymphatic vasculature, and act as an essential physical barrier, control nutrient transport, facilitate tissue immunosurveillance and coordinate angiogenesis and lymphangiogenesis1,2. In the intestine, dietary and microbial cues are particularly important in the regulation of organ homeostasis. However, whether enteric endothelial cells actively sense and integrate such signals is currently unknown. Here we show that the aryl hydrocarbon receptor (AHR) acts as a critical node for endothelial cell sensing of dietary metabolites in adult mice and human primary endothelial cells. We first established a comprehensive single-cell endothelial atlas of the mouse small intestine, uncovering the cellular complexity and functional heterogeneity of blood and lymphatic endothelial cells. Analyses of AHR-mediated responses at single-cell resolution identified tissue-protective transcriptional signatures and regulatory networks promoting cellular quiescence and vascular normalcy at steady state. Endothelial AHR deficiency in adult mice resulted in dysregulated inflammatory responses and the initiation of proliferative pathways. Furthermore, endothelial sensing of dietary AHR ligands was required for optimal protection against enteric infection. In human endothelial cells, AHR signalling promoted quiescence and restrained activation by inflammatory mediators. Together, our data provide a comprehensive dissection of the effect of environmental sensing across the spectrum of enteric endothelia, demonstrating that endothelial AHR signalling integrates dietary cues to maintain tissue homeostasis by promoting endothelial cell quiescence and vascular normalcy.


Asunto(s)
Células Endoteliales , Receptores de Hidrocarburo de Aril , Humanos , Animales , Ratones , Receptores de Hidrocarburo de Aril/metabolismo , Células Endoteliales/metabolismo , Intestinos , Transducción de Señal , Homeostasis , Ligandos
3.
Nature ; 600(7890): 737-742, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34880491

RESUMEN

Stability of the epigenetic landscape underpins maintenance of the cell-type-specific transcriptional profile. As one of the main repressive epigenetic systems, DNA methylation has been shown to be important for long-term gene silencing; its loss leads to ectopic and aberrant transcription in differentiated cells and cancer1. The developing mouse germ line endures global changes in DNA methylation in the absence of widespread transcriptional activation. Here, using an ultra-low-input native chromatin immunoprecipitation approach, we show that following DNA demethylation the gonadal primordial germ cells undergo remodelling of repressive histone modifications, resulting in a sex-specific signature in mice. We further demonstrate that Polycomb has a central role in transcriptional control in the newly hypomethylated germline genome as the genetic loss of Ezh2 leads to aberrant transcriptional activation, retrotransposon derepression and dramatic loss of developing female germ cells. This sex-specific effect of Ezh2 deletion is explained by the distinct landscape of repressive modifications observed in male and female germ cells. Overall, our study provides insight into the dynamic interplay between repressive chromatin modifications in the context of a developmental reprogramming system.


Asunto(s)
Ensamble y Desensamble de Cromatina , Células Germinativas , Animales , Cromatina/genética , Cromatina/metabolismo , Inmunoprecipitación de Cromatina , Metilación de ADN , Epigénesis Genética , Femenino , Células Germinativas/metabolismo , Masculino , Ratones , Proteínas del Grupo Polycomb/metabolismo
4.
Genome Res ; 33(1): 80-95, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36414416

RESUMEN

The identification and characterization of circulating tumor cells (CTCs) are important for gaining insights into the biology of metastatic cancers, monitoring disease progression, and medical management of the disease. The limiting factor in the enrichment of purified CTC populations is their sparse availability, heterogeneity, and altered phenotypes relative to the primary tumor. Intensive research both at the technical and molecular fronts led to the development of assays that ease CTC detection and identification from peripheral blood. Most CTC detection methods based on single-cell RNA sequencing (scRNA-seq) use a mix of size selection, marker-based white blood cell (WBC) depletion, and antibodies targeting tumor-associated antigens. However, the majority of these methods either miss out on atypical CTCs or suffer from WBC contamination. We present unCTC, an R package for unbiased identification and characterization of CTCs from single-cell transcriptomic data. unCTC features many standard and novel computational and statistical modules for various analyses. These include a novel method of scRNA-seq clustering, named deep dictionary learning using k-means clustering cost (DDLK), expression-based copy number variation (CNV) inference, and combinatorial, marker-based verification of the malignant phenotypes. DDLK enables robust segregation of CTCs and WBCs in the pathway space, as opposed to the gene expression space. We validated the utility of unCTC on scRNA-seq profiles of breast CTCs from six patients, captured and profiled using an integrated ClearCell FX and Polaris workflow that works by the principles of size-based separation of CTCs and marker-based WBC depletion.


Asunto(s)
Células Neoplásicas Circulantes , Humanos , Células Neoplásicas Circulantes/metabolismo , Transcriptoma , Variaciones en el Número de Copia de ADN , Perfilación de la Expresión Génica , Biomarcadores de Tumor
5.
Nature ; 580(7802): 263-268, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32269334

RESUMEN

In cells, organs and whole organisms, nutrient sensing is key to maintaining homeostasis and adapting to a fluctuating environment1. In many animals, nutrient sensors are found within the enteroendocrine cells of the digestive system; however, less is known about nutrient sensing in their cellular siblings, the absorptive enterocytes1. Here we use a genetic screen in Drosophila melanogaster to identify Hodor, an ionotropic receptor in enterocytes that sustains larval development, particularly in nutrient-scarce conditions. Experiments in Xenopus oocytes and flies indicate that Hodor is a pH-sensitive, zinc-gated chloride channel that mediates a previously unrecognized dietary preference for zinc. Hodor controls systemic growth from a subset of enterocytes-interstitial cells-by promoting food intake and insulin/IGF signalling. Although Hodor sustains gut luminal acidity and restrains microbial loads, its effect on systemic growth results from the modulation of Tor signalling and lysosomal homeostasis within interstitial cells. Hodor-like genes are insect-specific, and may represent targets for the control of disease vectors. Indeed, CRISPR-Cas9 genome editing revealed that the single hodor orthologue in Anopheles gambiae is an essential gene. Our findings highlight the need to consider the instructive contributions of metals-and, more generally, micronutrients-to energy homeostasis.


Asunto(s)
Canales de Cloruro/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crecimiento & desarrollo , Drosophila melanogaster/metabolismo , Ingestión de Alimentos/fisiología , Intestinos/fisiología , Zinc/metabolismo , Animales , Drosophila melanogaster/genética , Enterocitos/metabolismo , Femenino , Preferencias Alimentarias , Homeostasis , Insectos Vectores , Insulina/metabolismo , Activación del Canal Iónico , Larva/genética , Larva/crecimiento & desarrollo , Larva/metabolismo , Lisosomas/metabolismo , Masculino , Oocitos/metabolismo , Proteínas Tirosina Quinasas Receptoras/metabolismo , Transducción de Señal , Xenopus
6.
J Cell Mol Med ; 28(6): e18163, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38445776

RESUMEN

Malic enzyme (ME) genes are key functional metabolic enzymes playing a crucial role in carcinogenesis. However, the detailed effects of ME gene expression on breast cancer progression remain unclear. Here, our results revealed ME1 expression was significantly upregulated in breast cancer, especially in patients with oestrogen receptor/progesterone receptor-negative and human epidermal growth factor receptor 2-positive breast cancer. Furthermore, upregulation of ME1 was significantly associated with more advanced pathological stages (p < 0.001), pT stage (p < 0.001) and tumour grade (p < 0.001). Kaplan-Meier analysis revealed ME1 upregulation was associated with poor disease-specific survival (DSS: p = 0.002) and disease-free survival (DFS: p = 0.003). Multivariate Cox regression analysis revealed ME1 upregulation was significantly correlated with poor DSS (adjusted hazard ratio [AHR] = 1.65; 95% CI: 1.08-2.52; p = 0.021) and DFS (AHR, 1.57; 95% CI: 1.03-2.41; p = 0.038). Stratification analysis indicated ME1 upregulation was significantly associated with poor DSS (p = 0.039) and DFS (p = 0.038) in patients with non-triple-negative breast cancer (TNBC). However, ME1 expression did not affect the DSS of patients with TNBC. Biological function analysis revealed ME1 knockdown could significantly suppress the growth of breast cancer cells and influence its migration ability. Furthermore, the infiltration of immune cells was significantly reduced when they were co-cultured with breast cancer cells with ME1 knockdown. In summary, ME1 plays an oncogenic role in the growth of breast cancer; it may serve as a potential biomarker of progression and constitute a therapeutic target in patients with breast cancer.


Asunto(s)
Neoplasias de la Mama Triple Negativas , Humanos , Mama , Carcinogénesis , Técnicas de Cocultivo , Supervivencia sin Enfermedad
7.
Mol Cancer ; 23(1): 91, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38715012

RESUMEN

BACKGROUND: Recent evidence has demonstrated that abnormal expression and regulation of circular RNA (circRNAs) are involved in the occurrence and development of a variety of tumors. The aim of this study was to investigate the effects of circ_PPAPDC1A in Osimertinib resistance in NSCLC. METHODS: Human circRNAs microarray analysis was conducted to identify differentially expressed (DE) circRNAs in Osimertinib-acquired resistance tissues of NSCLC. The effect of circ_PPAPDC1A on cell proliferation, invasion, migration, and apoptosis was assessed in both in vitro and in vivo. Dual-luciferase reporter assay, RT-qPCR, Western-blot, and rescue assay were employed to confirm the interaction between circ_PPAPDC1A/miR-30a-3p/IGF1R axis. RESULTS: The results revealed that circ_PPAPDC1A was significantly upregulated in Osimertinib acquired resistance tissues of NSCLC. circ_PPAPDC1A reduced the sensitivity of PC9 and HCC827 cells to Osimertinib and promoted cell proliferation, invasion, migration, while inhibiting apoptosis in Osimertinib-resistant PC9/OR and HCC829/OR cells, both in vitro and in vivo. Silencing circ_PPAPDC1A partially reversed Osimertinib resistance. Additionally, circ_PPAPDC1A acted as a competing endogenous RNA (ceRNA) by targeting miR-30a-3p, and Insulin-like Growth Factor 1 Receptor (IGF1R) was identified as a functional gene for miR-30a-3p in NSCLC. Furthermore, the results confirmed that circ_PPAPDC1A/miR-30a-3p/IGF1R axis plays a role in activating the PI3K/AKT/mTOR signaling pathway in NSCLC with Osimertinib resistance. CONCLUSIONS: Therefore, for the first time we identified that circ_PPAPDC1A was significantly upregulated and exerts an oncogenic role in NSCLC with Osimertinib resistance by sponging miR-30a-3p to active IGF1R/PI3K/AKT/mTOR pathway. circ_PPAPDC1A may serve as a novel diagnostic biomarker and therapeutic target for NSCLC patients with Osimertinib resistance.


Asunto(s)
Acrilamidas , Compuestos de Anilina , Carcinoma de Pulmón de Células no Pequeñas , Proliferación Celular , Resistencia a Antineoplásicos , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares , MicroARNs , ARN Circular , Receptor IGF Tipo 1 , Transducción de Señal , Humanos , MicroARNs/genética , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Receptor IGF Tipo 1/genética , Receptor IGF Tipo 1/metabolismo , Resistencia a Antineoplásicos/genética , Acrilamidas/farmacología , ARN Circular/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/metabolismo , Compuestos de Anilina/farmacología , Línea Celular Tumoral , Animales , Ratones , Apoptosis , Movimiento Celular/genética , Ensayos Antitumor por Modelo de Xenoinjerto , Masculino , Femenino , Indoles , Pirimidinas
8.
Mol Med ; 30(1): 86, 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38877399

RESUMEN

BACKGROUND: Despite the advances of therapies, multiple myeloma (MM) remains an incurable hematological cancer that most patients experience relapse. Tumor angiogenesis is strongly correlated with cancer relapse. Human leukocyte antigen G (HLA-G) has been known as a molecule to suppress angiogenesis. We aimed to investigate whether soluble HLA-G (sHLA-G) was involved in the relapse of MM. METHODS: We first investigated the dynamics of serum sHLA-G, vascular endothelial growth factor (VEGF) and interleukin 6 (IL-6) in 57 successfully treated MM patients undergoing remission and relapse. The interactions among these angiogenesis-related targets (sHLA-G, VEGF and IL-6) were examined in vitro. Their expression at different oxygen concentrations was investigated using a xenograft animal model by intra-bone marrow and skin grafts with myeloma cells. RESULTS: We found that HLA-G protein degradation augmented angiogenesis. Soluble HLA-G directly inhibited vasculature formation in vitro. Mechanistically, HLA-G expression was regulated by hypoxia-inducible factor-1α (HIF-1α) in MM cells under hypoxia. We thus developed two mouse models of myeloma xenografts in intra-bone marrow (BM) and underneath the skin, and found a strong correlation between HLA-G and HIF-1α expressions in hypoxic BM, but not in oxygenated tissues. Yet when stimulated with IL-6, both HLA-G and HIF-1α could be targeted to ubiquitin-mediated degradation via PARKIN. CONCLUSION: These results highlight the importance of sHLA-G in angiogenesis at different phases of multiple myeloma. The experimental evidence that sHLA-G as an angiogenesis suppressor in MM may be useful for future development of novel therapies to prevent relapse.


Asunto(s)
Antígenos HLA-G , Interleucina-6 , Mieloma Múltiple , Neovascularización Patológica , Mieloma Múltiple/sangre , Mieloma Múltiple/metabolismo , Mieloma Múltiple/patología , Humanos , Animales , Neovascularización Patológica/metabolismo , Antígenos HLA-G/sangre , Antígenos HLA-G/metabolismo , Ratones , Interleucina-6/sangre , Interleucina-6/metabolismo , Masculino , Femenino , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/sangre , Persona de Mediana Edad , Línea Celular Tumoral , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Anciano , Modelos Animales de Enfermedad , Angiogénesis
9.
Oncologist ; 29(4): e455-e466, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-37995303

RESUMEN

BACKGROUND: CDK4/6 inhibitors (CDK4/6i) have shown great efficacy in prolonging progression-free survival and is the current standard of care for hormone positive (HR(+)) metastatic breast cancer (mBC). Despite well tolerability and ease of use, the most common side effect of CDK4/6i is myelosuppression, with neutropenia the most prevalent adverse effect. Studies show that the prevalence and severity of neutropenia are more marked in Asian patients, although details remain obscure. METHODS: In this study, we retrospectively analyzed 105 Taiwanese patients who received palbociclib for HR(+) HER2(-) mBC at the Taipei Veterans General Hospital. To investigate a possible genetic association for high prevalence of neutropenia, we queried the Taiwan Biobank with publicly available germline databases (ALFA, gnomAD, ExAC, 1000 Genomes project, HapMap), for the allele frequencies of 4 neutropenia-related SNPs (ABCB1_rs1045642, ABCB1_rs1128503, ERCC1_rs3212986, ERCC1_rs11615) and compared between different ethnicities. In addition, one of the patients was a long-term patient with peritoneal dialysis. We quantified the levels of palbociclib in her serum and peritoneal fluid by liquid chromatography-mass spectrometry (LC-MS). RESULTS: Interestingly, in our cohort, early neutropenia nadir (occurred within 56 days of start) was associated with worse treatment outcome, while occurrence of grade 3/4 neutropenia was associated with better outcome. We observed an extremely high incidence of neutropenia (96.2% any grade, 70.4% grade 3/4). In the analyzed germline databases, we discovered a higher SNP frequency of the T allele in ABCB1_rs1128503, a lower frequency of T allele in ABCB1_rs1045642, and a higher SNP frequency of G allele in ERCC1_rs11615. We observed that palbociclib levels in peritoneal dialysate ranged from around 20-50 ppb, and serum levels reached 100-110 ppb during drug administration and decreased to <10 ppb during discontinuation. CONCLUSION: Our retrospective analysis of real world palbociclib use reveals an association with grade 3/4 neutropenia with better outcome and early neutropenia nadir with worse outcome. Our findings of Asian specific SNPs support a predisposition toward profound and prevalent neutropenia in Asian patients under CDK4/6i. We also report the first pharmacokinetics analysis on a patient with peritoneal dialysis receiving CDK4/6i. In summary, our study provides novel clinical and genotypic insights into CDK4/6i associated neutropenia.


Asunto(s)
Neoplasias de la Mama , Neutropenia , Piperazinas , Piridinas , Femenino , Humanos , Estudios Retrospectivos , Prevalencia , Receptor ErbB-2/genética , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Neutropenia/inducido químicamente , Neutropenia/epidemiología , Neutropenia/genética , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Quinasa 4 Dependiente de la Ciclina
10.
Cancer Immunol Immunother ; 73(1): 3, 2024 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-38175307

RESUMEN

A number of the inhibitors against programmed death protein 1 (PD-1) have been approved to treat recurrent or metastatic squamous cell carcinoma of head and neck (HNSCC). The interaction between PD-1 and its ligand (PD-L1) serves as an immune checkpoint that governs cytotoxic immune effectors against tumors. Numerous clinical trials of PD-1/PD-L1 inhibitors have so far been discordant about having sufficient PD-L1 expression in the tumor as a prerequisite for a successful anti-PD-1 treatment. On the other hand, vascular endothelial cells modulate immune activities through PD-L1 expression, and thus it is possible that the expressions of circulating endothelial cells (CECs) and circulating endothelial progenitor cells (CPCs) could affect antitumor immunity as well as neoangiogenesis. Here we investigated the potential involvement of PD-L1+ CECs and PD-L1+ CPCs in PD-1 blockade treatments for HNSCC patients. We measured CD8+ T cells, CECs, and CPCs in the peripheral blood of the HNSCC patients treated by anti-PD-1 therapies. We found that their PD-L1+ CPC expression before anti-PD1 therapies was strongly correlated with treatment responses and overall survival. Moreover, if the first infusion of PD-1 inhibitors reduced ≥ 50% PD-L1+ CPCs, a significantly better outcome could be predicted. In these patients as well as in an animal model of oral cancer, Pd-l1+ CPC expression was associated with limited CD8+ T-cell infiltration into the tumors, and anti-PD-1 treatments also targeted Pd-l1+ CPCs and increased CD8+ T-cell infiltration. Our results highlight PD-L1+ CPC as a potential regulator in the anti-PD-1 treatments for HNSCC.


Asunto(s)
Células Progenitoras Endoteliales , Neoplasias de Cabeza y Cuello , Animales , Humanos , Carcinoma de Células Escamosas de Cabeza y Cuello/tratamiento farmacológico , Receptor de Muerte Celular Programada 1 , Antígeno B7-H1 , Linfocitos T CD8-positivos , Inhibidores de Puntos de Control Inmunológico , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Inmunidad
11.
J Transl Med ; 22(1): 359, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38632656

RESUMEN

BACKGROUND: Myelodysplastic neoplasms (MDS) are myeloid neoplasms characterized by disordered differentiation of hematopoietic stem cells and a predisposition to acute myeloid leukemia (AML). The underline pathogenesis remains unclear. METHODS: In this study, the trajectory of differentiation and mechanisms of leukemic transformation were explored through bioinformatics analysis of single-cell RNA-Seq data from hematopoietic stem and progenitor cells (HSPCs) in MDS patients. RESULTS: Among the HSPC clusters, the proportion of common myeloid progenitor (CMP) was the main cell cluster in the patients with excess blasts (EB)/ secondary AML. Cell cycle analysis indicated the CMP of MDS patients were in an active proliferative state. The genes involved in the cell proliferation, such as MAML3 and PLCB1, were up-regulated in MDS CMP. Further validation analysis indicated that the expression levels of MAML3 and PLCB1 in patients with MDS-EB were significantly higher than those without EB. Patients with high expression of PLCB1 had a higher risk of transformation to AML. PLCB1 inhibitor can suppress proliferation, induce cell cycle arrest, and activate apoptosis of leukemic cells in vitro. CONCLUSION: This study revealed the transcriptomic change of HSPCs in MDS patients along the pseudotime and indicated that PLCB1 plays a key role in the transformation of MDS into leukemia.


Asunto(s)
Leucemia Mieloide Aguda , Síndromes Mielodisplásicos , Humanos , Transcriptoma , Células Madre Hematopoyéticas/metabolismo , Síndromes Mielodisplásicos/patología , Leucemia Mieloide Aguda/genética , Perfilación de la Expresión Génica
12.
Plant Physiol ; 192(2): 1000-1015, 2023 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-36856724

RESUMEN

Cell wall synthesis and protein glycosylation require the import of nucleotide diphosphate-sugar conjugates into the Golgi that must be counterbalanced by phosphate (Pi) export. Numerous Golgi nucleotide-sugar transporters have been characterized, but transporters mediating Golgi Pi export remain poorly understood. We used plant and yeast genetics to characterize the role of 2 Arabidopsis (Arabidopsis thaliana) proteins possessing an EXS domain, namely ERD1A and ERD1B, in Golgi Pi homeostasis. ERD1A and ERD1B localized in cis-Golgi and were broadly expressed in vegetative and reproductive tissues. We identified ERD1 putative orthologs in algae, bryophytes, and vascular plants. Expressing ERD1A and ERD1B in yeast complemented the erd1 mutant phenotype of cellular Pi loss via exocytosis associated with reduced Golgi Pi export. The Arabidopsis erd1a mutant had a similar phenotype of apoplastic Pi loss dependent on exocytosis. ERD1A overexpression in Nicotiana benthamiana and Arabidopsis led to partial mislocalization of ERD1A to the plasma membrane and specific Pi export to the apoplastic space. Arabidopsis erd1a had defects in cell wall biosynthesis, which were associated with reduced shoot development, hypocotyl growth, cell wall extensibility, root elongation, pollen germination, pollen tube elongation, and fertility. We identified ERD1 proteins as Golgi Pi exporters that are essential for optimal plant growth and fertility.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Transporte de Fosfato/genética , Proteínas de Transporte de Fosfato/metabolismo , Saccharomyces cerevisiae/metabolismo , Aparato de Golgi/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Desarrollo de la Planta , Nucleótidos/metabolismo
13.
Plant Physiol ; 191(3): 1719-1733, 2023 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-36567484

RESUMEN

Accumulation of incompletely folded proteins in the endoplasmic reticulum (ER) leads to ER stress, activates ER protein degradation pathways, and upregulates genes involved in protein folding. This process is known as the unfolded protein response (UPR). The role of ER protein folding in plant responses to nutrient deficiencies is unclear. We analyzed Arabidopsis (Arabidopsis thaliana) mutants affected in ER protein quality control and established that both CALNEXIN (CNX) genes function in the primary root response to phosphate (Pi) deficiency. CNX1 and CNX2 are homologous ER lectins promoting protein folding of N-glycosylated proteins via the recognition of the GlcMan9GlcNAc2 glycan. Growth of cnx1-1 and cnx2-2 single mutants was similar to that of the wild type under high and low Pi conditions, but the cnx1-1 cnx2-2 double mutant showed decreased primary root growth under low Pi conditions due to reduced meristematic cell division. This phenotype was specific to Pi deficiency; the double mutant responded normally to osmotic and salt stress. Expression of CNX2 mutated in amino acids involved in binding the GlcMan9GlcNAc2 glycan failed to complement the cnx1-1 cnx2-2 mutant. The root growth phenotype was Fe-dependent and was associated with root apoplastic Fe accumulation. Two genes involved in Fe-dependent inhibition of primary root growth under Pi deficiency, the ferroxidase LOW PHOSPHATE 1 (LPR1) and P5-type ATPase PLEIOTROPIC DRUG RESISTANCE 2 (PDR2) were epistatic to CNX1/CNX2. Overexpressing PDR2 failed to complement the cnx1-1 cnx2-2 root phenotype. The cnx1-1 cnx2-2 mutant showed no evidence of UPR activation, indicating a limited effect on ER protein folding. CNX might process a set of N-glycosylated proteins specifically involved in the response to Pi deficiency.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Calnexina/genética , Calnexina/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Chaperonas Moleculares/metabolismo , Retículo Endoplásmico/metabolismo , Estrés del Retículo Endoplásmico/genética , Fosfatos/metabolismo , Glicoproteínas/metabolismo , Adenosina Trifosfatasas/metabolismo
14.
Plant Physiol ; 192(4): 3049-3068, 2023 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-37073492

RESUMEN

NLP7 (NIN-LIKE-PROTEIN 7) is the major transcriptional factor responsible for the primary nitrate response (PNR), but the role of its homolog, NLP6, in nitrogen signaling and the interplay between NLP6 and NLP7 remain to be elucidated. In this study, we show that, like NLP7, nuclear localization of NLP6 via a nuclear retention mechanism is nitrate dependent, but nucleocytosolic shuttling of both NLP6 and NLP7 is independent of each other. Compared with single mutants, the nlp6nlp7 double mutant displays a synergistic growth retardation phenotype in response to nitrate. The transcriptome analysis of the PNR showed that NLP6 and NLP7 govern ∼50% of nitrate-induced genes, with cluster analysis highlighting 2 distinct patterns. In the A1 cluster, NLP7 plays the major role, whereas in the A2 cluster, NLP6 and NLP7 are partially functionally redundant. Interestingly, comparing the growth phenotype and PNR under high- and low-nitrate conditions demonstrated that NLP6 and NLP7 exert a more dominant role in the response to high nitrate. Apart from nitrate signaling, NLP6 and NLP7 also participated in high ammonium conditions. Growth phenotypes and transcriptome data revealed that NLP6 and NLP7 are completely functionally redundant and may act as repressors in response to ammonium. Other NLP family members also participated in the PNR, with NLP2 and NLP7 acting as broader regulators and NLP4, -5, -6, and -8 regulating PNR in a gene-dependent manner. Thus, our findings indicate that multiple modes of interplay exist between NLP6 and NLP7 that differ depending on nitrogen sources and gene clusters.


Asunto(s)
Compuestos de Amonio , Proteínas de Arabidopsis , Arabidopsis , Nitratos/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Factores de Transcripción/metabolismo , Nitrógeno/metabolismo , Compuestos de Amonio/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/metabolismo
15.
Plant Cell ; 33(5): 1492-1505, 2021 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-33580260

RESUMEN

Compared with root development regulated by external nutrients, less is known about how internal nutrients are monitored to control plasticity of shoot development. In this study, we characterize an Arabidopsis thaliana transceptor, NRT1.13 (NPF4.4), of the NRT1/PTR/NPF family. Different from most NRT1 transporters, NRT1.13 does not have the conserved proline residue between transmembrane domains 10 and 11; an essential residue for nitrate transport activity in CHL1/NRT1.1/NPF6.3. As expected, when expressed in oocytes, NRT1.13 showed no nitrate transport activity. However, when Ser 487 at the corresponding position was converted back to proline, NRT1.13 S487P regained nitrate uptake activity, suggesting that wild-type NRT1.13 cannot transport nitrate but can bind it. Subcellular localization and ß-glucuronidase reporter analyses indicated that NRT1.13 is a plasma membrane protein expressed at the parenchyma cells next to xylem in the petioles and the stem nodes. When plants were grown with a normal concentration of nitrate, nrt1.13 showed no severe growth phenotype. However, when grown under low-nitrate conditions, nrt1.13 showed delayed flowering, increased node number, retarded branch outgrowth, and reduced lateral nitrate allocation to nodes. Our results suggest that NRT1.13 is required for low-nitrate acclimation and that internal nitrate is monitored near the xylem by NRT1.13 to regulate shoot architecture and flowering time.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Flores/fisiología , Nitratos/farmacología , Brotes de la Planta/anatomía & histología , Animales , Arabidopsis/efectos de los fármacos , Proteínas de Arabidopsis/genética , Transporte Biológico/efectos de los fármacos , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Flores/efectos de los fármacos , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Proteínas de Dominio MADS/metabolismo , Modelos Biológicos , Mutación/genética , Fenotipo , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/crecimiento & desarrollo , Factores de Tiempo , Xenopus , Xilema/metabolismo
16.
Ann Hematol ; 2024 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-38671297

RESUMEN

The molecular pathogenesis of extranodal NK/T-cell lymphoma (NKTCL) remains obscured despite the next-generation sequencing (NGS) studies explored on ever larger cohorts in the last decade. We addressed the highly variable mutation frequencies reported among previous studies with comprehensive amplicon coverage and enhanced sequencing depth to achieve higher genomic resolution for novel genetic discovery and comparative mutational profiling of the oncogenesis of NKTCL. Targeted exome sequencing was conducted to interrogate 415 cancer-related genes in a cohort of 36 patients with NKTCL, and a total of 548 single nucleotide variants (SNVs) and 600 Copy number variances (CNVs) were identified. Recurrent amplification of the MCL1 (67%) and PIM1 (56%) genes was detected in a dominant majority of patients in our cohort. Functional mapping of genetic aberrations revealed that an enrichment of mutations in the JAK-STAT signaling pathway, including the cytokine receptor LIFR (copy number loss) upstream of JAK3, STAT3 (activating SNVs), and downstream effectors of MYC, PIM1 and MCL1 (copy number gains). RNA in situ hybridization showed the significant consistence of MCL1 RNA level and copy number of MCL1 gene. We further correlated molecular and clinical parameters with overall survival (OS) of these patients. When correlations were analyzed by univariate followed by multivariate modelling, only copy number loss of LIFR gene and stage (III-IV) were independent prognostic factors of reduced OS. Our findings identified that novel loss of LIFR gene significantly correlated with the adverse clinical outcome of NKTCL patients and provided therapeutic opportunities for this disease through manipulating LIFR.

17.
Faraday Discuss ; 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38808590

RESUMEN

Electron-induced dissociation of a fluorocarbon adsorbate CF3 (ad) at 4.6 K is shown by Scanning Tunnelling Microscopy (STM) to form directed energetic F-atom 'projectiles' on Cu(110). The outcome of a collision between these directed projectiles and stationary co-adsorbed allyl 'target' molecules was found through STM to give rotational excitation of the target allyl, clockwise or anti-clockwise, depending on the chosen collision geometry. Molecular dynamics computation linked the collisional excitation of the allyl target to an 'abortive chemical reaction', in which the approach of the F-projectile stretched an H-C bond lifting the allyl above the surface, facilitating isomerization from 'Across' to 'Along' a Cu row.

18.
Cell ; 138(6): 1184-94, 2009 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-19766570

RESUMEN

Ions serve as essential nutrients in higher plants and can also act as signaling molecules. Little is known about how plants sense changes in soil nutrient concentrations. Previous studies showed that T101-phosphorylated CHL1 is a high-affinity nitrate transporter, whereas T101-dephosphorylated CHL1 is a low-affinity transporter. In this study, analysis of an uptake- and sensing-decoupled mutant showed that the nitrate transporter CHL1 functions as a nitrate sensor. Primary nitrate responses in CHL1T101D and CHLT101A transgenic plants showed that phosphorylated and dephosphorylated CHL1 lead to a low- and high-level response, respectively. In vitro and in vivo studies showed that, in response to low nitrate concentrations, protein kinase CIPK23 can phosphorylate T101 of CHL1 to maintain a low-level primary response. Thus, CHL1 uses dual-affinity binding and a phosphorylation switch to sense a wide range of nitrate concentrations in the soil, thereby functioning as an ion sensor in higher plants. For a video summary of this article, see the PaperFlick file with the Supplemental Data available online.


Asunto(s)
Proteínas de Transporte de Anión/metabolismo , Arabidopsis/metabolismo , Nitratos/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas , Fosforilación , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo
19.
Epilepsy Behav ; 151: 109647, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38232558

RESUMEN

Childhood absence epilepsy (CAE) is a common type of idiopathic generalized epilepsy, manifesting as daily multiple absence seizures. Although seizures in most patients can be adequately controlled with first-line antiseizure medication (ASM), approximately 25 % of patients respond poorly to first-line ASM. In addition, an accurate method for predicting first-line medication responsiveness is lacking. We used the quantitative electroencephalogram (QEEG) features of patients with CAE along with machine learning to predict the therapeutic effects of valproic acid in this population. We enrolled 25 patients with CAE from multiple medical centers. Twelve patients who required additional medication for seizure control or who were shifted to another ASM and 13 patients who achieved seizure freedom with valproic acid within 6 months served as the nonresponder and responder groups. Using machine learning, we analyzed the interictal background EEG data without epileptiform discharge before ASM. The following features were analyzed: EEG frequency bands, Hjorth parameters, detrended fluctuation analysis, Higuchi fractal dimension, Lempel-Ziv complexity (LZC), Petrosian fractal dimension, and sample entropy (SE). We applied leave-one-out cross-validation with support vector machine, K-nearest neighbor (KNN), random forest, decision tree, Ada boost, and extreme gradient boosting, and we tested the performance of these models. The responders had significantly higher alpha band power and lower delta band power than the nonresponders. The Hjorth mobility, LZC, and SE values in the temporal, parietal, and occipital lobes were higher in the responders than in the nonresponders. Hjorth complexity was higher in the nonresponders than in the responders in almost all the brain regions, except for the leads FP1 and FP2. Using KNN classification with theta band power in the temporal lobe yielded optimal performance, with sensitivity of 92.31 %, specificity of 76.92 %, accuracy of 84.62 %, and area under the curve of 88.46 %.We used various EEG features along with machine learning to accurately predict whether patients with CAE would respond to valproic acid. Our method could provide valuable assistance for pediatric neurologists in selecting suitable ASM.


Asunto(s)
Epilepsia Tipo Ausencia , Niño , Humanos , Epilepsia Tipo Ausencia/diagnóstico , Epilepsia Tipo Ausencia/tratamiento farmacológico , Ácido Valproico/uso terapéutico , Convulsiones/tratamiento farmacológico , Electroencefalografía/métodos , Aprendizaje Automático
20.
Exp Cell Res ; 429(1): 113652, 2023 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-37209991

RESUMEN

Damage associated molecular patterns (DAMPs), including calreticulin (CRT) exposure, high-mobility group box 1 protein (HMGB1) elevation, and ATP release, characterize immunogenic cell death (ICD) and may play a role in cancer immunotherapy. Triple negative breast cancer (TNBC) is an immunogenic subtype of breast cancer with higher lymphocyte infiltration. Here, we found that regorafenib, a multi-target angiokinase inhibitor previously known to suppress STAT3 signaling, induced DAMPs and cell death in TNBC cells. Regorafenib induced the expression of HMGB1 and CRT, and the release of ATP. Regorafenib-induced HMGB1 and CRT were attenuated following STAT3 overexpression. In a 4T1 syngeneic murine model, regorafenib treatment increased HMGB1 and CRT expression in xenografts, and effectively suppressed 4T1 tumor growth. Immunohistochemical staining revealed increased CD4+ and CD8+ tumor-infiltrating T cells in 4T1 xenografts following regorafenib treatment. Regorafenib treatment or programmed death-1 (PD-1) blockade using anti-PD-1 monoclonal antibody reduced lung metastasis of 4T1 cells in immunocompetent mice. While regorafenib increases the proportion of MHC II high expression on dendritic cells in mice with smaller tumors, the combination of regorafenib and PD-1 blockade did not show a synergistic effect on anti-tumor activity. These results suggest that regorafenib induces ICD and suppresses tumor progression in TNBC. It should be carefully evaluated when developing a combination therapy with an anti-PD-1 antibody and a STAT3 inhibitor.


Asunto(s)
Proteína HMGB1 , Neoplasias de la Mama Triple Negativas , Ratones , Humanos , Animales , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Neoplasias de la Mama Triple Negativas/metabolismo , Proteína HMGB1/farmacología , Muerte Celular , Adenosina Trifosfato/farmacología , Línea Celular Tumoral
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