Numerous studies have been focusing on breeding tomato plants with enhanced lycopene accumulation, considering its positive effects of fruits on the visual and functional properties. In this study, we used a bidirectional strategy: promoting the biosynthesis of lycopene, while inhibiting the conversion from lycopene to β- and α-carotene. The accumulation of lycopene was promoted by knocking down some genes associated with the carotenoid metabolic pathway. Finally, five genes were selected to be edited in genome by CRISPR/Cas9 system using Agrobacterium tumefaciens-mediated transformation. Our findings indicated that CRISPR/Cas9 is a site-specific genome editing technology that allows highly efficient target mutagenesis in multiple genes of interest. Surprisingly, the lycopene content in tomato fruit subjected to genome editing was successfully increased to about 5.1-fold. The homozygous mutations were stably transmitted to subsequent generations. Taken together, our results suggest that CRISPR/Cas9 system can be used for significantly improving lycopene content in tomato fruit with advantages such as high efficiency, rare off-target mutations, and stable heredity.
SummaryIn recent years, the type II CRISPR system has become a widely used and robust technique to implement site‐directed mutagenesis in a variety of species including model and crop plants. However, few studies manipulated metabolic pathways in plants using the CRISPR system. Here, we introduced the pYLCRISPR/Cas9 system with one or two single‐site guide RNAs to target the tomato phytoene desaturase gene. An obvious albino phenotype was observed in T0 regenerated plants, and more than 61% of the desired target sites were edited. Furthermore, we manipulated the γ‐aminobutyric acid (GABA) shunt in tomatoes using a multiplex pYLCRISPR/Cas9 system that targeted five key genes. Fifty‐three genome‐edited plants were obtained following single plant transformation, and these samples represented single to quadruple mutants. The GABA accumulation in both the leaves and fruits of genomically edited lines was significantly enhanced, and the GABA content in the leaves of quadruple mutants was 19‐fold higher than that in wild‐type plants. Our data demonstrate that the multiplex CRISPR/Cas9 system can be exploited to precisely edit tomato genomic sequences and effectively create multisite knockout mutations, which could shed new light on plant metabolic engineering regulations.
Objective: We investigated the contribution of several cytokines in the pathogenesis of first-onset neuromyelitis optica spectrum disorder (NMOSD) and determined the differences between aquaporin 4 immunoglobulin G (AQP4-IgG)-positive and AQP4-IgG-negative subtypes. Methods: We enrolled 18 NMOSD (10 AQP4-IgG-positive and 8 AQP4-IgG-negative) and 8 multiple sclerosis (MS) patients, whose serum and cerebrospinal fluid (CSF) samples were collected during the acute phase of the first onset before immunotherapy. Fifteen patients with other noninflammatory neurological diseases (OND) were also included. The serum and CSF levels of interleukin (IL)-6, IL-10, IL-17, IL-21, IL-23, transforming growth factor (TGF)-β1 and the CSF levels of 3 biomarkers of axonal loss and astrocytic damage were measured using the human cytokine multiplex assay or ELISA. Results: Serum levels of IL-10 and TGF-β1 and CSF levels of IL-6, IL-10, and TGF-β1 were significantly increased in first-onset NMOSD compared to in OND patients. In a subgroup analysis, the CSF levels of IL-6, neurofilament light protein (NFL), S100B, and glial fibrillary acidic protein (GFAP) were significantly more elevated in the AQP4-IgG-positive patients than in the AQP4-IgG-negative NMOSD patients. Correlations were found between the CSF cytokines and tissue damage biomarkers and the clinical findings in NMOSD patients. Notably, the CSF IL-6 level had the strongest correlation with the tissue damage biomarkers and it also correlated with CSF white blood cell (WBC) count. Conclusions: IL-6 plays a role in the pathogenetic process of NMOSD, especially in the AQP4-IgG-positive subtype. Distinct pathogenesis exists between AQP4-IgG-positive and AQP4-IgG-negative NMOSD in the initial phase of the disease.
Astrocytic impairment is a pathologic feature of neuromyelitis optica spectrum disorder (NMOSD). S100B and glial fibrillary acidic protein (GFAP) are the two most commonly used astrocytic markers. The aim of this study was to evaluate whether CSF-S100B could serve as a marker of NMOSD. We enrolled 49 NMOSD patients [25 aquaporin-4 antibody (AQP4-Ab)–positive, 8 myelin-oligodendrocyte glycoprotein antibody (MOG-Ab)-positive, and 16 seronegative patients], 12 multiple sclerosis (MS) patients, and 15 other noninflammatory neurological diseases (OND) patients. The CSF levels of S100B and GFAP were measured by ELISA. Both CSF-S100B and GFAP levels significantly discriminated NMOSD from MS [area under curve (AUC) = 0.839 and 0.850, respectively] and OND (AUC = 0.839 and 0.850, respectively). The CSF-S100B levels differentiated AQP4-Ab–positive NMOSD from MOG-Ab–positive NMOSD with higher accuracy than the CSF-GFAP levels (AUC=0.865 and 0.772, respectively). The CSF-S100B levels also significantly discriminated MOG-Ab–positive patients from seronegative patients (AUC = 0.848). Both CSF-S100B and GFAP levels were correlated with the Expanded Disability Status Scale (EDSS) during remission. Only the CSF-S100B levels were correlated with the CSF WBC count and the EDSS during attack. The levels of CSF-S100B seemed to have a longer lasting time than the levels of CSF-GFAP, which may benefit patients who present late. As a result, CSF-S100B might be a potential candidate biomarker for NMOSD in discriminating, evaluating severity, and predicting disability.
Previously, a number of microRNAs (miRNAs) have been reported to be dysregulated in cervical cancer, and dysregulated miRNAs may play crucial roles in the development and progression of cervical cancer. Hence, investigating the detailed roles of miRNAs that are aberrantly expressed in cervical cancer and the underlying molecular mechanisms is essential for early diagnosis and effective therapeutic approaches. miRNA-877 (miR-877) was found to be downregulated in hepatocellular carcinoma and renal cell carcinoma, and function as a tumor-suppressive miRNA. However, how miR-877 exerts an effect in cervical cancer progression and its underlying molecular mechanisms remains to be elucidated. In the current study, reverse transcription-quantitative PCR was performed to determine miR-877 expression in cervical cancer tissues and cell lines. The effects of miR-877 overexpression on cervical cancer cell proliferation and invasion were evaluated using MTT and Transwell cell invasion assays. In the present study, miR-877 was significantly downregulated in cervical cancer tissues and cell lines, and the decreased expression levels of miR-877 were significantly associated with increased International Federation of Gynecology and Obstetric stage as well as increased lymph node metastasis in patients with cervical cancer. Upregulation of miR-877 using miR-877 mimics resulted in the decreased proliferation and invasion of cervical cancer cells. Metastasis-associated in colon cancer-1 (MACC1) was assessed using bioinformatics analyses to determine whether it could be a potential target gene of miR-877, and the results were confirmed using a luciferase reporter assay. Furthermore, MACC1 was markedly upregulated in cervical cancer tissues, and its level was negatively correlated with the miR-877 level. Overexpression of miR-877 resulted in decreased expression levels of MACC1 in cervical cancer cells at both the mRNA and protein levels. In addition, the functional effects of MACC1 knockdown were similar to those induced by upregulated miR-877 in cervical cancer cells. MACC1 restored miR-877 overexpression-mediated suppression of cervical cancer cell proliferation and invasion. In conclusion, miR-877 may play an antitumor role in cervical cancer by directly targeting MACC1, which suggests that this miRNA may be a promising therapeutic target for the treatment of patients with such an aggressive gynecological cancer.
We formulate an economic optimal control problem for transport of natural gas over a large-scale transmission pipeline network under transient flow conditions. The objective is to maximize economic welfare for users of the pipeline system, who provide time-dependent price and quantity bids to purchase or supply gas at metered locations on a system with time-varying injections, withdrawals, and control actions of compressors and regulators. Our formulation ensures that pipeline hydraulic limitations, compressor station constraints, operational factors, and pre-existing contracts for gas transport are satisfied. A pipeline is modeled as a metric graph with gas dynamics partial differential equations on edges and coupling conditions at the nodes. These dynamic constraints are reduced using lumped elements to a sparse nonlinear differential algebraic equation system. A highly efficient temporal discretization scheme for time-periodic formulations is introduced, which we extend to develop a rolling-horizon model-predictive control scheme. We apply the computational methodology to a pipeline system test network case study. In addition to the physical flow and compressor control solution, the optimization yields dual functions that we interpret as the time-dependent economic values of gas at each location in the network. † azlotnik@lanl.gov,
Densely grafted bottlebrush statistical copolymers (BSCPs) and bottlebrush block copolymers (BBCPs) were synthesized with polystyrene (PS) and poly(solketal methacrylate) (PSM) side chains grafted to a polynorbornene backbone. The PSM chains could be hydrolyzed into poly(glycerol monomethacrylate) (PGM), significantly increasing the segmental interaction parameter (χ). Self-assembly of the polymers was studied with small-angle X-ray scattering before and after hydrolysis. The well-known rapid self-assembly of BBCPs by thermal annealing was retarded after hydrolysis, due to a large χ between the segments of the brushes. Utilizing the well-ordered lamellar morphology before hydrolysis, we developed a solid-state hydrolysis method to achieve high-χ BBCPs with long-range order. Analysis of the Porod scattering invariant showed that for high-χ BBCPs, the density of each phase deviated from the density of linear homopolymer melts due to multiple restrictions placed on the configuration of the brushes.
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