RESUMO
The osmotic resistance mechanism has been extensively studied in whole plants or plant tissues. However, little is known about it in embryogenic tissue (ET) which is widely used in plant-based biotechnological systems. Suberin, a cell wall aliphatic and aromatic heteropolymer, plays a critical role in plant cells against osmosis stress. The suberin regulatory biosynthesis has rarely been studied in gymnosperms. Here, PaMYB11, a subgroup 11 R2R3-MYB transcription factor, plays a key role in the osmotic resistance of Norway spruce (Picea abies) ETs during cryoprotectant pretreatment. Thus, RNA-seq, histological, and analytical chemical analyses are performed on the stable transformations of PaMYB11-OE and PaMYB11-SRDX in Norway spruce ETs. DAP-seq, Y1H, and LUC are further combined to explore the PaMYB11 targets. Activation of PaMYB11 is necessary and sufficient for suberin lamellae deposition on Norway spruce embryogenic cell walls, which plays a decisive role in ET survival under osmotic stress. Transcriptome analysis shows that PaMYB11 enhances suberin lamellae monomer synthesis by promoting very long-chain fatty acid (VLCFA) synthesis. PaPOP, PaADH1, and PaTET8L, the first two (PaADH1 and PaPOP, included) involved in VLCFA synthesis, are proved to be the direct targets of PaMYB11. Our study identified a novel osmotic response directed by PaMYB11 in Norway spruce ET, which provides a new understanding of the resistance mechanism against osmosis in gymnosperms.
RESUMO
Herbivore-induced plant volatiles (HIPVs) are known to be perceived by neighboring plants, resulting in induction or priming of chemical defenses. There is little information on the defense responses that are triggered by these plant-plant interactions, and the phenomenon has rarely been studied in rice. Using chemical and molecular analyses in combination with insect behavioral and performance experiments, we studied how volatiles emitted by rice plants infested by the striped stemborer (SSB) Chilo suppressalis affect defenses against this pest in conspecific plants. Compared with rice plants exposed to the volatiles from uninfested plants, plants exposed to SSB-induced volatiles showed enhanced direct and indirect resistance to SSB. When subjected to caterpillar damage, the HIPV-exposed plants showed increased expression of jasmonic acid (JA) signaling genes, resulting in JA accumulation and higher levels of defensive proteinase inhibitors. Moreover, plants exposed to SSB-induced volatiles emitted larger amounts of inducible volatiles and were more attractive to the parasitoid Cotesia chilonis. By unraveling the factors involved in HIPV-mediated defense priming in rice, we reveal a key defensive role for proteinase inhibitors. These findings pave the way for novel rice management strategies to enhance the plant's resistance to one of its most devastating pests.
Assuntos
Mariposas , Oryza , Compostos Orgânicos Voláteis , Animais , Oryza/genética , Plantas/metabolismo , Insetos/metabolismo , Herbivoria , Peptídeo Hidrolases/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Ciclopentanos/metabolismoRESUMO
The challenge to improve the clinical efficacy and enlarge the population that benefits from immune checkpoint inhibitors (ICIs) for non-small-cell lung cancer (NSCLC) is significant. Based on whole-exosome sequencing analysis of biopsies from NSCLC patients before anti-programmed cell death protein-2 (PD-1) treatment, we identified NLRP4 mutations in the responders with a longer progression-free survival (PFS). Knockdown of NLRP4 in mouse Lewis lung cancer cell line enhanced interferon (IFN)-α/ß production through the cGAS-STING-IRF3/IRF7 axis and promoted the accumulation of intratumoral CD8+ T cells, leading to tumor growth retardation in vivo and a synergistic effect with anti-PD-ligand 1 therapy. This was consistent with clinical observations that more tumor-infiltrating CD8+ T cells and elevated peripheral IFN-α before receiving nivolumab treatment were associated with a longer PFS in NSCLC patients. Our study highlights the roles of tumor-intrinsic NLRP4 in remodeling the immune contextures in the tumor microenvironment, making regional type I IFN beneficial for ICI treatment.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Antígeno B7-H1/antagonistas & inibidores , Inibidores de Checkpoint Imunológico/uso terapêutico , Interferon Tipo I/metabolismo , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Linfócitos T CD8-Positivos/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/imunologia , Linhagem Celular Tumoral , Feminino , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Pessoa de Meia-Idade , Mutação , Intervalo Livre de Progressão , Transdução de Sinais/efeitos dos fármacos , Resultado do Tratamento , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologiaRESUMO
BACKGROUND: Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by the presence of pathogenic autoantibodies associated with polyclonal B cell hyperreactivity. Previous study reported that autophagy-related gene Leucine-rich repeat kinase 2 (LRRK2) was likely a susceptible gene for SLE. However, the pathogenic function of LRRK2 in SLE is undefined. METHODS: Using quantitative PCR, we compared the expression levels of LRRK2 in B cells between SLE patients and healthy controls. The expression levels of LRRK2 in in vitro induced CD19hi B cells and naïve B cells were compared as well based on RNA-seq assay. A pristane-induced lupus-like mouse model was used to explore the effects of LRRK2 on the development of SLE. IgG level, B cell subsets in the spleens and bone marrows and pathological features in the kidneys were compared between wildtype (WT) and Lrrk2-/- littermates. RESULTS: It was obvious that LRRK2 expression was dramatically up-regulated in primary B cells from SLE patients compared to those from healthy controls, as well as in activated CD19hi B cells. More significantly, LRRK2 expression in B cells was positively correlated with system lupus erythematosus disease activity index (SLEDAI), an indicator for disease severity, and serum IgG levels in SLE patients. Negative correlations were observed between LRRK2 expression and serum C3 or C4 levels, two clinical features associated with SLE-related nephritis. LRRK2 deficiency reduced the death rate of pristane treated mice. Decreased levels of total IgG and autoantibody were detected in the serum with less deposition of immune complexes and attenuated pathological symptoms in the kidneys of Lrrk2-/- mice. Consistent with the reduction in IgG production, the percentages of germinal center B cells and plasma cells decreased significantly as well with LRRK2 deficiency. CONCLUSIONS: Our study demonstrates that LRRK2 expression is upregulated in B cells from SLE patients with strong correlations to disease severity. LRRK2 deficiency largely attenuates the pathogenic progress of lupus-like features in pristane-induced mice. This is probably achieved through affecting B cell terminal differentiation and subsequent immunoglobulin production.
Assuntos
Formação de Anticorpos/imunologia , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/metabolismo , Lúpus Eritematoso Sistêmico/enzimologia , Lúpus Eritematoso Sistêmico/imunologia , Animais , Linfócitos B/imunologia , Estudos de Casos e Controles , Feminino , Centro Germinativo/imunologia , Rim/patologia , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/deficiência , Lúpus Eritematoso Sistêmico/patologia , Ativação Linfocitária/imunologia , Camundongos Endogâmicos C57BL , Plasmócitos/imunologia , Índice de Gravidade de Doença , Terpenos , Regulação para CimaRESUMO
To explore the adjuvant therapy drugs of low-dose metformin, one homogeneous polysaccharide named APS-D1 was purified from Astragalus membranaceus by DEAE-52 cellulose and Sephadex G-100 column chromatography. Its chemical structure was characterized by molecular weight distribution, monosaccharide composition, infrared spectrum, methylation analysis, and NMR. The results revealed that APS-D1 (7.36 kDa) consisted of glucose, galactose, and arabinose (97.51 %:1.56 %:0.93 %). It consisted of â4)-α-D-Glcp-(1â residue backbone with â3)-ß-D-Galp-(1â residue and terminal-α/ß-D-Glcp-(1â side chains. APS-D1 could significantly improve inflammation (TNF-α, LPS, and IL-10) in vivo. Moreover, APS-D1 improved the curative effect of low-dose metformin without adverse events. APS-D1 combined with low-dose metformin regulated several gut bacteria, in which APS-D1 enriched Staphylococcus lentus to produce l-carnitine (one of 136 metabolites of S. lentus). S. lentus and l-carnitine could improve diabetes, and reduction of S. lentusl-carnitine production impaired diabetes improvement. The combination, S. lentus, and l-carnitine could promote fatty acid oxidation (CPT1) and inhibit gluconeogenesis (PCK and G6Pase). The results indicated that APS-D1 enhanced the curative effect of low-dose metformin to improve diabetes by enriching S. lentus, in which the effect of S. lentus was mediated by l-carnitine. Collectively, these findings support that low-dose metformin supplemented with APS-D1 may be a favorable therapeutic strategy for type 2 diabetes.
Assuntos
Metformina , Polissacarídeos , Staphylococcus , Metformina/farmacologia , Metformina/química , Animais , Polissacarídeos/farmacologia , Polissacarídeos/química , Staphylococcus/efeitos dos fármacos , Camundongos , Astrágalo/química , Masculino , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/farmacologia , Hipoglicemiantes/química , Peso MolecularRESUMO
DnaJs are the common molecular chaperone proteins with strong structural and functional diversity. In recent years, only several DnaJ family members have been found to be able to regulate leaf color, and it remains to be explored whether there are other potential members that also regulate this character. Here, we identified 88 putative DnaJ proteins from Catalpa bungei, and classified them into four types according to their domain. Gene-structure analysis revealed that each member of CbuDnaJ family had same or similar exon-intron structure. Chromosome mapping and collinearity analysis showed that tandem and fragment duplication occurred in the process of evolution. Promoter analyses suggested that CbuDnaJs might be involved in a variety of biological processes. The expression levels of DnaJ family members in different color leaves of Maiyuanjinqiu were respectively extracted from the differential transcriptome. Among these, CbuDnaJ49 was the largest differentially expressed gene between the green and yellow sectors. Ectopic overexpression of CbuDnaJ49 in tobacco showed that the positive transgenic seedlings exhibited albino leaves, and the contents of chlorophyll and carotenoid were significantly reduced compared with those of wild type. The results suggested that CbuDnaJ49 played an important role in regulating leaf color. This study not only identified a novel gene of DnaJ family members regulating leaf color, but also provided new germplasm for landscaping.
RESUMO
Branched-chain amino acids (BCAAs) provide nutrient signals for cell survival and growth. How BCAAs affect CD8+ T cell functions remains unexplored. Herein, we report that accumulation of BCAAs in CD8+ T cells due to the impairment of BCAA degradation in 2C-type serine/threonine protein phosphatase (PP2Cm)-deficient mice leads to hyper-activity of CD8+ T cells and enhanced anti-tumor immunity. CD8+ T cells from PP2Cm-/- mice upregulate glucose transporter Glut1 expression in a FoxO1-dependent manner with more glucose uptake, as well as increased glycolysis and oxidative phosphorylation. Moreover, BCAA supplementation recapitulates CD8+ T cell hyper-functions and synergizes with anti-PD-1, in line with a better prognosis in NSCLC patients containing high BCAAs when receiving anti-PD-1 therapy. Our finding thus reveals that accumulation of BCAAs promotes effector function and anti-tumor immunity of CD8+ T cells through reprogramming glucose metabolism, making BCAAs alternative supplementary components to increase the clinical efficacy of anti-PD-1 immunotherapy against tumors.
Assuntos
Aminoácidos de Cadeia Ramificada , Linfócitos T CD8-Positivos , Animais , Camundongos , Aminoácidos de Cadeia Ramificada/metabolismo , Linfócitos T CD8-Positivos/metabolismo , GlucoseRESUMO
Intravesical bacillus Calmette-Guerin (BCG) instillation is recommended as an adjuvant therapy for intermediate-risk and high-risk non-muscle invasive bladder cancer (NMIBC) after transurethral resection of bladder tumor (TURBt) with nearly 70% reoccurrence. In the present study, we investigated the dynamics of peripheral purified protein derivative (PPD)-specific immune responses along the treatment. Intravesical BCG instillation caused a significant increase in peripheral PPD-specific IFN-γ release of NMIBC patients, when compared to those receiving chemo-drug instillation. Through a follow-up study, we detected rapid increase in PPD-specific IFN-γ, IL-2, and IL-17A producing CD4+ and CD8+ T cells in the induction phase. Interestingly, the frequencies of PPD-specific IFN-γ and IL-2 producing CD4+ and CD8+ T cells decreased dramatically after induction treatment and were restored after BCG re-instillation, whereas IL-17A-producing T cells remained at the maintenance phase. However, we only observed that the percentages of peripheral CD8+ T cells were significantly higher in BCG responder patients than those in BCG refractory patients at the baseline with the potential of predicting the recurrence. A more dramatic increase in PPD-specific IFN-γ and IL-2 producing CD4+ and CD8+ T cells after one and two dose BCG instillations was observed in refractory NMIBC patients. Therefore, regional BCG instillation induced transient peripheral PPD-specific T cell responses, which could be restored through repetitive BCG instillation. Higher proportions of peripheral CD8+ T cells at baseline were associated with better responses to BCG instillation for the prevention of recurrence of bladder cancer.
RESUMO
Branched-chain amino acids (BCAAs) are the three essential amino acids including leucine, isoleucine, and valine. BCAA metabolism has been linked with the development of a variety of tumors. However, the impact of dietary BCAA intake on breast tumor progression and metastasis remains to be fully explored. Here, we unexpectedly find that the elevated BCAA, either in the genetic model or via increasing dietary intake in mice, suppresses the tumor growth and lung metastasis of breast cancer. The survival analysis shows that BCAA catabolic gene expression is strongly associated with long-term oncological outcomes in patients with breast cancer. In Pp2cm knockout mice in which BCAAs accumulate due to the genetic defect of BCAA catabolism, the breast tumor growth is suppressed. Interestingly, while the cell proliferation and tumor vasculature remain unaffected, more cell death occurs in the tumor in Pp2cm knockout mice, accompanied with increased natural killer (NK) cells. Importantly, increasing BCAA dietary intake suppresses breast tumor growth in mice. On the other hand, there are fewer lung metastases from primary breast tumor in Pp2cm knockout mice and the high BCAA diet-fed mice, suggesting high BCAA also suppresses the lung metastasis of breast cancer. Furthermore, low BCAA diet promotes lung colonization of breast cancer cells in tail vein model. The migration and invasion abilities of breast cancer cells are impaired by high concentration of BCAA in culture medium. The suppressed tumor metastasis and cell migration/invasion abilities by elevated BCAA are accompanied with reduced N-cadherin expression. Together, these data show high BCAA suppresses both tumor growth and metastasis of breast cancer, demonstrating the potential benefits of increasing BCAA dietary intake in the treatment of breast cancer.
RESUMO
Koolen-de Vries syndrome (KdVS) is a rare disorder caused by haploinsufficiency of KAT8 regulatory NSL complex subunit 1 (KANSL1), which is characterized by intellectual disability, heart failure, hypotonia, and congenital malformations. To date, no effective treatment has been found for KdVS, largely due to its unknown pathogenesis. Using siRNA screening, we identified KANSL1 as an essential gene for autophagy. Mechanistic study shows that KANSL1 modulates autophagosome-lysosome fusion for cargo degradation via transcriptional regulation of autophagosomal gene, STX17. Kansl1+/- mice exhibit impairment in the autophagic clearance of damaged mitochondria and accumulation of reactive oxygen species, thereby resulting in defective neuronal and cardiac functions. Moreover, we discovered that the FDA-approved drug 13-cis retinoic acid can reverse these mitophagic defects and neurobehavioral abnormalities in Kansl1+/- mice by promoting autophagosome-lysosome fusion. Hence, these findings demonstrate a critical role for KANSL1 in autophagy and indicate a potentially viable therapeutic strategy for KdVS.
Assuntos
Anormalidades Múltiplas/genética , Deficiência Intelectual/genética , Mitofagia/genética , Proteínas Nucleares/genética , Anormalidades Múltiplas/tratamento farmacológico , Anormalidades Múltiplas/imunologia , Anormalidades Múltiplas/patologia , Animais , Autofagossomos/efeitos dos fármacos , Autofagossomos/metabolismo , Autofagossomos/patologia , Córtex Cerebral/citologia , Córtex Cerebral/patologia , Deleção Cromossômica , Cromossomos Humanos Par 17/genética , Cromossomos Humanos Par 17/imunologia , Modelos Animais de Doenças , Feminino , Haploinsuficiência/imunologia , Células HeLa , Humanos , Deficiência Intelectual/tratamento farmacológico , Deficiência Intelectual/imunologia , Deficiência Intelectual/patologia , Isotretinoína/farmacologia , Isotretinoína/uso terapêutico , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Lisossomos/patologia , Camundongos , Camundongos Transgênicos , Mitofagia/efeitos dos fármacos , Mitofagia/imunologia , Neurônios , Proteínas Nucleares/metabolismo , Cultura Primária de CélulasRESUMO
The communication between glioblastoma stem cells (GSCs) and the surrounding microenvironment is a prominent feature accounting for the aggressive biology of glioblastoma multiforme (GBM). However, the mechanisms by which GSCs proactively drive interactions with microenvironment is not well understood. In this study, we interrogated metabolites that are preferentially secreted from GSCs and found that GSCs produce and secrete histamine to shape a pro-angiogenic tumor microenvironment. This histamine-producing ability is attributed to H3K4me3 modification-activated histidine decarboxylase (HDC) transcription via MYC. Notably, HDC is highly expressed in GBM, which is associated with poor survival of these patients. GSC-secreted histamine activates endothelial cells by triggering a histamine H1 receptor (H1R)-Ca2+-NF-κB axis, thereby promoting angiogenesis and GBM progression. Importantly, pharmacological blockage of H1R using antihistamines impedes the growth of GBM xenografts in mice. Our findings establish that GSC-specific metabolite secretion remodels the tumor microenvironment and highlight histamine targeting as a potential strategy for GBM therapy.
Assuntos
Neoplasias Encefálicas , Glioblastoma , Humanos , Camundongos , Animais , Glioblastoma/patologia , Histamina/metabolismo , Microambiente Tumoral , Neoplasias Encefálicas/patologia , Células Endoteliais/metabolismo , Células-Tronco Neoplásicas/patologia , Linhagem Celular TumoralRESUMO
Limited benefit population of immune checkpoint inhibitors makes it urgent to screen predictive biomarkers for stratifying the patients. Herein, we have investigated peripheral CD4+ T cell signatures in advanced non-small cell lung cancer (NSCLC) patients receiving anti-PD-1/PD-L1 treatments. It was found that the percentages of IFN-γ and IL-17A secreting naïve CD4+ T cells (Tn), and memory CD4+ T cells (Tm) expressing PD-1, PD-L1 and CTLA-4 were significantly higher in responder (R) than non-responder (NonR) NSCLC patients associated with a longer progression free survival (PFS). Logistic regression analysis revealed that the baseline IFN-γ-producing CD4+ Tn cells and PD-1+CD4+ Tm cells were the most significant signatures with the area under curve (AUC) value reaching 0.849. This was further validated in another anti-PD-1 monotherapy cohort. Conversely, high percentage of CTLA-4+CD4+ Tm cells was associated with a shorter PFS in patients receiving anti-PD-L1 monotherapy. Our study therefore elucidates the significance of functional CD4+ Tn and Tm subpopulations before the treatment in predicting the responses to anti-PD-1 treatment in Chinese NSCLC patients. The fact that there display distinct CD4+ T cell signatures in the prediction to anti-PD-1 and anti-PD-L1 monotherapy from our study provides preliminary evidence on the feasibility of anti-PD-1 and anti-PD-L1 combination therapy for advanced NSCLC patients.
Assuntos
Linfócitos T CD4-Positivos/metabolismo , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , China , Citocinas/metabolismo , Feminino , Humanos , Proteínas de Checkpoint Imunológico/metabolismo , Neoplasias Pulmonares/sangue , Masculino , Células T de Memória/metabolismo , Pessoa de Meia-Idade , Nivolumabe/uso terapêutico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Intervalo Livre de ProgressãoRESUMO
INTRODUCTION: Gut microbiome affecting the responses to immune checkpoint inhibitors against advanced NSCLC has been investigated in the Western population. However, considering pre-existing genetic and gut microbiota variation, the relevance remains unknown in the East-Asian NSCLC population. This study is designed to explore the relationship between gut microbiome and clinical outcomes in Chinese patients with NSCLC who have received treatment using an anti-programmed death 1 (PD-1) blockade. METHODS: Thirty-seven patients with advanced NSCLC receiving treatment with nivolumab were enrolled in CheckMate 078 (NCT02613507) and CheckMate 870 (NCT03195491). Fecal samples were collected at the starting point, when patients received nivolumab, at clinical evaluation, and when disease progression was noted. 16S ribosome RNA gene sequencing was applied to assess gut microbiota profiles. Peripheral immune signatures were determined by multicolor flow cytometry in parallel. RESULTS: When subgrouping patients into responder (R) and nonresponder according to the clinical response assessed using Response Evaluation Criteria in Solid Tumor version 1.1, R patients harbored higher diversity of gut microbiome at the starting point with stable composition during the treatment. Patients with high microbiome diversity had significantly prolonged progression-free survival when compared to those with low diversity. Compositional difference was observed between the two groups as well with the enrichment of Alistipes putredinis, Bifidobacterium longum, and Prevotella copri in R whereas Ruminococcus_unclassified enriched in nonresponding patients. Analysis of systemic immune responses using multicolor flow cytometry revealed that patients with a high abundance of microbiome diversity in the gut had a greater frequency of unique memory CD8+ T cell and natural killer cell subsets in the periphery in response to anti-PD-1 therapy. CONCLUSIONS: Our results reveal strong correlation between gut microbiome diversity and the responses to anti-PD-1 immunotherapy in Chinese patients with advanced NSCLC. Patients with favorable gut microbiome (such as those with high diversity) exhibit enhanced memory T cell and natural killer cell signatures in the periphery. These findings provide important implications for the prediction and the evaluation of anti-PD-1 immunotherapy against NSCLC in the Chinese population.
Assuntos
Antineoplásicos Imunológicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Microbioma Gastrointestinal/imunologia , Neoplasias Pulmonares/tratamento farmacológico , Nivolumabe/uso terapêutico , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Povo Asiático , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/microbiologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Ensaios Clínicos como Assunto , Progressão da Doença , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/microbiologia , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Receptor de Morte Celular Programada 1/imunologiaRESUMO
Aged and damaged mitochondria can be selectively degraded by specific autophagic elimination, termed mitophagy. Defects in mitophagy have been increasingly linked to several diseases including neurodegenerative diseases, metabolic diseases and other aging-related diseases. However, the molecular mechanisms of mitophagy are not fully understood. Here, we identify PRPF8 (pre-mRNA processing factor 8), a core component of the spliceosome, as an essential mediator in hypoxia-induced mitophagy from an RNAi screen based on a fluorescent mitophagy reporter, mt-Keima. Knockdown of PRPF8 significantly impairs mitophagosome formation and subsequent mitochondrial clearance through the aberrant mRNA splicing of ULK1, which mediates macroautophagy/autophagy initiation. Importantly, autosomal dominant retinitis pigmentosa (adRP)-associated PRPF8 mutant R2310K is defective in regulating mitophagy. Moreover, knockdown of other adRP-associated splicing factors, including PRPF6, PRPF31 and SNRNP200, also lead to ULK1 mRNA mis-splicing and mitophagy defects. Thus, these findings demonstrate that PRPF8 is essential for mitophagy and suggest that dysregulation of spliceosome-mediated mitophagy may contribute to pathogenesis of retinitis pigmentosa.
Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Genes Dominantes , Hipóxia/genética , Mitofagia/genética , Fatores de Processamento de RNA/genética , Splicing de RNA/genética , Proteínas de Ligação a RNA/genética , Retinose Pigmentar/genética , Animais , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Regulação da Expressão Gênica , Células HeLa , Humanos , Camundongos , Mutação/genética , Fagossomos/metabolismo , Fagossomos/ultraestrutura , Interferência de RNA , Fatores de Processamento de RNA/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Spliceossomos/metabolismoRESUMO
A simutaneous distillation extraction (SDE) combined GC method was constructed for determination of volatile flavor components in Pu-erh tea samples. Dichloromethane and ethyl decylate was employed as organic phase in SDE and internal standard in determination, respectively. Weakly polar DB-5 column was used to separate the volatile flavor components in GC, 10 of the components were quantitatively analyzed, and further confirmed by GC-MS. The recovery covered from 66.4%-109%, and repeatability expressed as RSD was in range of 1.44%-12.6%. SDE was most suitable for the extraction of the anlytes by comparing with steam distillation-liquid/liquid extraction and Soxhlet extraction. Commercially available Pu-erh tea samples, including Pu-erh raw tea and ripe tea, were analyzed by the constructed method. the high-volatile components, such as benzyl alcohol, linalool oxide, and linalool, were greatly rich in Pu-erh raw teas, while the contents of 1,2,3-Trimethoxylbenzene and 1,2,4-Trimethoxylbenzene were much high in Pu-erh ripe teas.