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1.
Mol Carcinog ; 63(5): 926-937, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38380957

RESUMO

Early treatment of retinoblastoma (RB) has significantly improved clinical outcomes. N6-methyladenosine (m6A) methylation is crucial for cancer progression. Thus, we investigated the role of FTO-dependent demethylation in RB and its underlying mechanisms. The biological behavior of RB cells was analyzed using cell counting kit-8, colony formation analysis, transwell assay, flow cytometry, and western blot analysis. m6A modification was evaluated using methylated RNA immunoprecipitation and dual-luciferase reporter assays, and E2F3 stability was assessed using Actinomycin D. The roles of FTO and E2F3 were also elucidated in vivo. These results indicated that FTO was highly expressed in RB cells with low m6A levels. FTO knockdown inhibited RB cell growth, migration, invasion, and epithelial-mesenchymal transition and arrested the cell cycle at the G0/G1 phase. Mechanistically, FTO interference promoted m6A methylation of E2F3, which was recognized by YTHDF2, thereby reducing mRNA stability. E2F3 overexpression partially rescued the effects of FTO knockdown on biological behavior. Moreover, FTO knockdown reduced tumor weight, tumor volume, ki67 expression, and tumor cell infiltration by mediating E2F3. Taken together, FTO silencing inhibited the malignant processes of RB by suppressing E2F3 in an m6A-YTHD2-dependent manner. These findings suggest that FTO is a novel therapeutic target for RB.


Assuntos
Dioxigenase FTO Dependente de alfa-Cetoglutarato , Fator de Transcrição E2F3 , Neoplasias da Retina , Retinoblastoma , Humanos , Adenosina , Dioxigenase FTO Dependente de alfa-Cetoglutarato/genética , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Ciclo Celular , Fator de Transcrição E2F3/genética , Fator de Transcrição E2F3/metabolismo , Retinoblastoma/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
2.
Biomed Eng Online ; 23(1): 25, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38419078

RESUMO

BACKGROUND: The accurate detection of eyelid tumors is essential for effective treatment, but it can be challenging due to small and unevenly distributed lesions surrounded by irrelevant noise. Moreover, early symptoms of eyelid tumors are atypical, and some categories of eyelid tumors exhibit similar color and texture features, making it difficult to distinguish between benign and malignant eyelid tumors, particularly for ophthalmologists with limited clinical experience. METHODS: We propose a hybrid model, HM_ADET, for automatic detection of eyelid tumors, including YOLOv7_CNFG to locate eyelid tumors and vision transformer (ViT) to classify benign and malignant eyelid tumors. First, the ConvNeXt module with an inverted bottleneck layer in the backbone of YOLOv7_CNFG is employed to prevent information loss of small eyelid tumors. Then, the flexible rectified linear unit (FReLU) is applied to capture multi-scale features such as texture, edge, and shape, thereby improving the localization accuracy of eyelid tumors. In addition, considering the geometric center and area difference between the predicted box (PB) and the ground truth box (GT), the GIoU_loss was utilized to handle cases of eyelid tumors with varying shapes and irregular boundaries. Finally, the multi-head attention (MHA) module is applied in ViT to extract discriminative features of eyelid tumors for benign and malignant classification. RESULTS: Experimental results demonstrate that the HM_ADET model achieves excellent performance in the detection of eyelid tumors. In specific, YOLOv7_CNFG outperforms YOLOv7, with AP increasing from 0.763 to 0.893 on the internal test set and from 0.647 to 0.765 on the external test set. ViT achieves AUCs of 0.945 (95% CI 0.894-0.981) and 0.915 (95% CI 0.860-0.955) for the classification of benign and malignant tumors on the internal and external test sets, respectively. CONCLUSIONS: Our study provides a promising strategy for the automatic diagnosis of eyelid tumors, which could potentially improve patient outcomes and reduce healthcare costs.


Assuntos
Neoplasias Palpebrais , Humanos , Neoplasias Palpebrais/diagnóstico , Área Sob a Curva , Custos de Cuidados de Saúde
3.
Funct Integr Genomics ; 23(1): 49, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36705739

RESUMO

Uveal melanoma (UM), a frequently seen adulthood primary ocular malignancy, shows high aggressiveness. Accumulating studies have revealed the crucial effects of microRNAs (miRNAs) on tumorigenesis and development in various human tumors. miR-204, the cancer-associated miRNA, shows dysregulation and is related to several human malignancies, but its effect on UM remains unknown. The present work focused on exploring miR-204's effect on UM and elucidating its possible molecular mechanisms. According to our results, miR-204 expression markedly increased within both UM tissues and cell lines. As revealed by functional analysis, miR-204 suppressed UM cell invasion and migration. Besides, RAB22A expression decreased through directly binding miR-204 into the corresponding 3' untranslated region (3'UTR) in UM cells. Furthermore, the RAB22A mRNA level increased, which was negatively related to the miR-204 level within UM samples. As revealed by mechanical research, miR-204 exerted its inhibition on the invasion and migration of UM cells via RAB22A. Taken together, this study suggested the tumor-suppressing effect of miR-204 on UM through down-regulating RAB22A. Thus, miR-204 may serve as the new anti-UM therapeutic target.


Assuntos
Melanoma , MicroRNAs , Humanos , Adulto , Linhagem Celular Tumoral , MicroRNAs/genética , MicroRNAs/metabolismo , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Movimento Celular/genética , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo
4.
Bioengineered ; 13(6): 14357-14367, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35758265

RESUMO

Epithelial-melancholy transition (EMT) is the main cause of organ fibrosis and a common pathogenetic mechanism in most cataracts. This study aimed to explore the molecular mechanism of Toll-like receptor (TLR)-3 in the occurrence and development of post-cataract EMT and to provide new ideas for the prevention and treatment of posterior capsule opacification (PCO). In the presence or absence of TLR3, the human lens epithelial cell (LEC) line, SRA01/04, was treated with the transforming growth factor (TGF)-ß2. Cell counting kit-8 (CCK-8) and Transwell assays were used to analyze the cell proliferation, migration, and invasion. The expression levels of proteins and RNAs were detected by western blotting and quantitative polymerase chain reaction (qPCR) experiments. Functional gain and loss studies showed that TLR3 regulates the proliferation, migration, and invasion of LECs and EMT induced by TGF-ß2. Moreover, TLR3 regulates the expression of Jagged-1, Notch-1, and Notch-3 These findings indicate that TLR3 prevents the progression of lens fibrosis by targeting the Jagged-1/Notch signaling pathway to regulate the proliferation, migration, and invasion of LECs, and TGF-ß2-induced EMT. Therefore, the TLR3-Jagged-1/Notch signaling axis may be a potential therapeutic target for the treatment of fibrotic cataracts.


Assuntos
Opacificação da Cápsula , Receptores Notch , Receptor 3 Toll-Like , Opacificação da Cápsula/genética , Opacificação da Cápsula/metabolismo , Opacificação da Cápsula/patologia , Movimento Celular/genética , Proliferação de Células/genética , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Transição Epitelial-Mesenquimal , Fibrose , Humanos , Proteína Jagged-1/genética , Proteína Jagged-1/metabolismo , Receptores Notch/genética , Receptores Notch/metabolismo , Transdução de Sinais/genética , Receptor 3 Toll-Like/genética , Receptor 3 Toll-Like/metabolismo , Fator de Crescimento Transformador beta2/farmacologia
5.
J Cataract Refract Surg ; 48(7): 859-862, 2022 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-35546428

RESUMO

A technique using the single-string, closed-loop fixation method to reposit dislocated triple-looped haptic intraocular lens (IOL)-capsular bag complex is described. The long needle or curved needle with a 10-0/8-0 polypropylene suture and a 27/30-gauge needle were used as the guide needle to pass through the fenestrated haptics twice. The scleral interlaminar course was used as the fixed point. Last, a fixation knot was created in the sclerotomy by the 2 ends of the thread to close the suture loop for IOL fixation. Another knot was created about 2 to 3 mm from the exit point and was intrasclerally anchored by the aid of the attached needle. 4 eyes from 4 consecutive patients were studied retrospectively; during all follow-up visits, the IOLs were well centered and stable, and no suture erosion, hypotony, scleral atrophy, chronic inflammation, retinal tears, and/or detachments were observed.


Assuntos
Tecnologia Háptica , Lentes Intraoculares , Humanos , Estudos Retrospectivos , Esclera/cirurgia , Técnicas de Sutura , Suturas , Acuidade Visual
6.
NPJ Digit Med ; 5(1): 23, 2022 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-35236921

RESUMO

Malignant eyelid tumors can invade adjacent structures and pose a threat to vision and even life. Early identification of malignant eyelid tumors is crucial to avoiding substantial morbidity and mortality. However, differentiating malignant eyelid tumors from benign ones can be challenging for primary care physicians and even some ophthalmologists. Here, based on 1,417 photographic images from 851 patients across three hospitals, we developed an artificial intelligence system using a faster region-based convolutional neural network and deep learning classification networks to automatically locate eyelid tumors and then distinguish between malignant and benign eyelid tumors. The system performed well in both internal and external test sets (AUCs ranged from 0.899 to 0.955). The performance of the system is comparable to that of a senior ophthalmologist, indicating that this system has the potential to be used at the screening stage for promoting the early detection and treatment of malignant eyelid tumors.

7.
Int J Ophthalmol ; 13(6): 879-885, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32566497

RESUMO

AIM: To investigate the effects of nintedanib thermo-sensitive hydrogel (NTH) on neovascularization and related markers in corneal alkali burns of Wistar rats. METHODS: NTH was prepared by grinding, and its phase-transition temperature was determined. Thirty specific-pathogen-free Wistar rats served as a model of corneal alkali burn in the right eye were randomly divided into 3 groups (n=10, each): model group treated with 0.9% saline once a day, NTH group with 0.2% nintedanib b.i.d, and dexamethasone group with dexamethasone ointment once a day. The left eye of rats served as the controls. The corneal transparency was observed under a slit-lamp microscope, and the area of neovascularization was calculated. On day 7, the rats were sacrificed, and the cornea was removed and embedded with paraffin, then stained with hematoxylin-eosin, and the expression of vascular endothelial growth factor receptor 2 (VEGFR-2) and CD31 in the corneal tissues of each group was detected by immunofluorescence. RESULTS: The phase-transition temperature of nintedanib obtained by grinding was 37°C after adding artificial tears. The results of the alkali burn model indicated that the growth rate of neovascularization in the NTH group was slower than that in the model group, and the neovascularization area was significantly smaller than that in the model group (P<0.05). Moreover, CD31 and VEGFR-2 expression levels in the NTH group were significantly lower than those in the model group. CONCLUSION: NTH becomes colloidal at body temperature, which is beneficial for releasing the drug slowly and can significantly inhibit the neovascularization of corneal induced by alkali burn in rats.

8.
J Int Med Res ; 48(6): 300060519896437, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32588673

RESUMO

OBJECTIVE: This study aimed to evaluate the association between plasma P-selectin levels and the severity of coronary heart disease (CHD) in a Chinese Han population. METHODS: We enrolled 219 patients with CHD and 168 healthy individuals without CHD as a control group. Coronary stenosis was evaluated based on the number of diseased coronary arteries and the Gensini scoring system. P-selectin levels were quantified by enzyme-linked immunosorbent assay and the association between CHD and plasma P-selectin level was analyzed. RESULTS: P-selectin levels were significantly higher in CHD patients compared with controls. Levels were highest in patients with three-vessel disease and lowest in those with one-vessel disease, with significant differences among the groups. P-selectin levels were also highest in the high-score and lowest in the low-score group according to Gensini score, with significant differences among the groups. P-selectin level was significantly positively correlated with Gensini score and C-reactive protein level. Elevated P-selectin was identified as an independent risk factor for CHD. CONCLUSION: P-selectin levels were increased in Chinese Han patients with CHD. P-selectin level is an independent risk factor for CHD and may serve as a biomarker reflecting the severity of CHD in the Chinese Han population.


Assuntos
Estenose Coronária , Selectina-P , Povo Asiático , China , Vasos Coronários , Humanos , Fatores de Risco
9.
Plant Cell Physiol ; 60(2): 285-302, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30351427

RESUMO

Plant organ development to a specific size and shape is controlled by cell proliferation and cell expansion. Here, we identify a novel Myb-like Arabidopsis gene, Development Related Myb-like1 (DRMY1), which controls cell expansion in both vegetative and reproductive organs. DRMY1 is strongly expressed in developing organs and its expression is reduced by ethylene while it is induced by ABA. DRMY1 has a Myb-like DNA-binding domain, which is predominantly localized in the nucleus and does not exhibit transcriptional activation activity. The loss-of-function T-DNA insertion mutant drmy1 shows reduced organ growth and cell expansion, which is associated with changes in the cell wall matrix polysaccharides. Interestingly, overexpression of DRMY1 in Arabidopsis does not lead to enhanced organ growth. Expression of genes involved in cell wall biosynthesis/remodeling, ribosome biogenesis and in ethylene and ABA signaling pathways is changed with the deficiency of DRMY1. Our results suggest that DRMY1 plays an essential role in organ development by regulating cell expansion either directly by affecting cell wall architecture and/or cytoplasmic growth or indirectly through the ethylene and/or ABA signaling pathways.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Proteínas de Ligação a DNA/genética , Sementes/crescimento & desenvolvimento , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/fisiologia , Proteínas de Arabidopsis/fisiologia , Proteínas de Ligação a DNA/fisiologia , Flores/crescimento & desenvolvimento , Germinação/fisiologia , Filogenia , Folhas de Planta/anatomia & histologia , Folhas de Planta/crescimento & desenvolvimento , Alinhamento de Sequência
10.
Cutan Ocul Toxicol ; 37(3): 233-239, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29298533

RESUMO

Lysergic acid diethylamide (LSD), a classical hallucinogen, was used as a popular and notorious substance of abuse in various parts of the world. Its abuse could result in long-lasting abnormalities in retina and little is known about the exact mechanism. This study was to investigate the effect of LSD on macrophage activation state at non-toxic concentration and its resultant toxicity to photoreceptor cells. Results showed that cytotoxicity was caused by LSD on 661 W cells after co-culturing with RAW264.7 cells. Treatment with LSD-induced RAW264.7 cells to the M1 phenotype, releasing more pro-inflammatory cytokines, and increasing the M1-related gene expression. Moreover, after co-culturing with RAW264.7 cells, significant oxidative stress in 661 W cells treated with LSD was observed, by increasing the level of malondialdehyde (MDA) and reactive oxygen species (ROS), and decreasing the level of glutathione (GSH) and the activity of superoxide dismutase (SOD). Our study demonstrated that LSD caused photoreceptor cell damage by inducing inflammatory response and resultant oxidative stress, providing the scientific rationale for the toxicity of LSD to retina.


Assuntos
Alucinógenos/toxicidade , Dietilamida do Ácido Lisérgico/toxicidade , Macrófagos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Células Fotorreceptoras de Vertebrados/efeitos dos fármacos , Animais , Técnicas de Cocultura , Citocinas/metabolismo , Macrófagos/imunologia , Camundongos , Células Fotorreceptoras de Vertebrados/metabolismo , Células RAW 264.7
11.
Plant Sci ; 262: 74-80, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28716422

RESUMO

Borage (Borago officinalis) is an annual herb that produces a high level of gamma-linolenic acid (GLA) in its seed oil. Due to the recognized health benefits of GLA, borage is now commercially cultivated worldwide. However, an herbicide-tolerant variety for effective weed management has not yet been developed. Here we report the generation and characterization of ethyl methanesulfonate (EMS) induced borage mutant lines tolerant to the herbicide imidazolinone. An EMS-mutagenized borage population was generated by using a series of concentrations of EMS to treat mature borage seeds. Screening of the M2 and M3 borage plants using an herbicide treatment resulted in the identification of two imidazolinone-tolerant lines. Sequence analysis of two acetohydroxyacid synthase (AHAS) genes, AHAS1 and AHAS2, from the mutant (tolerant) and wild type (susceptible) borage plants showed that single nucleotide substitutions which resulted in amino acid changes occurred in AHAS1 and AHAS2, respectively in the two tolerant lines. A KASP marker was then developed to differentiate the homozygous susceptible, homozygous tolerant and heterozygous borage plants. An in vitro assay showed that homozygous tolerant borage carrying the AHAS1 mutation retained significantly higher AHAS activity than susceptible borage across different imazamox concentrations. A herbicide dose response test indicated that the line with the AHAS1 mutation could tolerate four times the normally used field concentration of "Solo" herbicide.


Assuntos
Borago/efeitos dos fármacos , Borago/metabolismo , Herbicidas/farmacologia , Acetolactato Sintase/genética , Acetolactato Sintase/metabolismo , Borago/enzimologia , Metanossulfonato de Etila/farmacologia , Resistência a Herbicidas , Imidazolinas/farmacologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
12.
Am J Transl Res ; 8(9): 3947-3954, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27725874

RESUMO

Previous studies have shown that metformin, an AMP-activated protein kinase activator widely prescribed for type 2 diabetes, is especially beneficial in cases of diabetic retinopathy (DR) with undetermined mechanisms. Here, we used a streptozotocin-induced diabetes model in mice to study the effects of metformin on the development of DR. We found that 10 weeks after STZ treatment, DR was induced in STZ-treated mice, regardless treatment of metformin. However, metformin alleviated the DR, seemingly through attenuating the retina neovascularization. The total vascular endothelial cell growth factor A (VEGF-A) in eyes was not altered by metformin, but the phosphorylation of the VEGF receptor 2 (VEGFR2) was decreased, which inhibited VEGF signaling. Further analysis showed that metformin may induce VEGF-A mRNA splicing to VEGF120 isoform to reduce its activation of the VEGFR2. These findings are critical for generating novel medicine for DR treatment.

13.
Mitochondrial DNA A DNA Mapp Seq Anal ; 27(4): 2405-7, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-25835039

RESUMO

Variants in mitochondrial DNA (mtDNA) are the most important causes for vision loss, the mt-tRNA variants being the largest group among them. In this study, we report the molecular characterization of 15 mt-tRNA variants with primary congenital glaucoma (PCG). Based on phylogenetic approach, we found that only half of them were definitely pathogenic with PCG, other mutations were single nucleotide polymorphisms (SNP) in human population. Thus, our study provided novel insight into the pathogenesis of PCG.


Assuntos
Genes Mitocondriais , Estudos de Associação Genética , Variação Genética , Glaucoma/congênito , RNA de Transferência/genética , RNA , Alelos , Humanos , Mutação , Polimorfismo de Nucleotídeo Único , RNA Mitocondrial
14.
Transgenic Res ; 19(2): 221-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19582587

RESUMO

Eicosapentaenoic acid (EPA, 20:5n-3) plays an important role in many aspects of human health. In our efforts towards producing high levels of EPA in plants, we investigated the effects of different host species, genes and promoters on EPA biosynthesis. Zero-erucic acid Brassica carinata appeared to be an outstanding host species for EPA production, with EPA levels in transgenic seed of this line reaching up to 25%. Two novel genes, an 18-carbon omega3 desaturase (CpDesX) from Claviceps purpurea and a 20-carbon omega3 desaturase (Pir-omega3) from Pythium irregulare, proved to be very effective in increasing EPA levels in high-erucic acid B. carinata. The conlinin1 promoter from flax functioned reasonably well in B. carinata, and can serve as an alternative to the napin promoter from B. napus. In summary, the judicious selection of host species and promoters, together with the inclusion of genes that enhance the basic very long chain polyunsaturated fatty acid biosynthetic pathway, can greatly influence the production of EPA in plants.


Assuntos
Biotecnologia/métodos , Brassica/genética , Ácido Eicosapentaenoico/biossíntese , Ácidos Graxos Dessaturases/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/metabolismo , Brassica/classificação , Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Claviceps/enzimologia , Claviceps/genética , Ácidos Erúcicos/metabolismo , Ácidos Graxos Dessaturases/genética , Regulação da Expressão Gênica de Plantas , Humanos , Plantas Geneticamente Modificadas/enzimologia , Regiões Promotoras Genéticas , Pythium/enzimologia , Pythium/genética , Sementes/genética , Sementes/metabolismo , Especificidade da Espécie , Transformação Genética
16.
Transgenic Res ; 15(2): 131-7, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16604455

RESUMO

Very long-chain polyunsaturated fatty acids (VLCPUFAs) are essential for human health and well-being. However, the current sources of these valuable compounds are limited and may not be sustainable in the long term. Recently, considerable progress has been made in identifying genes involved in the biosynthesis of VLCPUFAs. The co-expression of these genes in model systems such as plant embryos or yeast provided many valuable insights into the mechanisms of VLCPUFA synthesis. The recent successful reconstitution of pathways leading to the synthesis of arachidonic acid, eicosapentaenoic acid and finally docosahexaenoic acid in oil-seed plants indicates the feasibility of using transgenic crops as alternative sources of VLCPUFAs. The various approaches used to attain these results and the specific constraints associated with each approach are discussed.


Assuntos
Ácidos Graxos Insaturados/biossíntese , Engenharia Genética , Plantas Geneticamente Modificadas , Plantas/genética , Plantas/metabolismo , Ácidos Docosa-Hexaenoicos/metabolismo
17.
Gene ; 363: 77-84, 2005 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-16226403

RESUMO

A cDNA (BG-15) was isolated through differential screening of a cDNA library made from an ABA-treated bromegrass (Bromus inermis Leyss) suspension cell culture. The 819 bp pair cDNA encoded a 174 amino acid polypeptide with a calculated molecular mass of 18.08 kD and isolectric point of 7.50. The deduced amino acid sequences for the cDNA were 29.5% and 32.6% homologous to the known amino acid-selective channel proteins of the chloroplastic outer membrane in pea and barley, but were highly homologous (55.6% to 83.2%) to the putative membrane channel proteins from rice and Arabidopsis. Immunogold localization demonstrated that the channel protein encoded by this cDNA was present on the peroxisome membrane. High stringency southern analysis revealed that 1 to 2 copies of the peroxisomal channel protein (PCP) genes were present in the bromegrass genome. Northern and Western blots revealed that the PCP gene was responsive to both cold and drought stresses, and was rapidly induced by ABA (75 microM). The transcript of the PCP gene also accumulated during late embryogenesis, but declined rapidly during germination. Data taken together, responsiveness of the PCP to cold and drought stresses, and accumulation during late embryogenesis suggest this novel peroxisomal channel protein is associated with sugar and fatty acid metabolism through fatty acid import or succinate export from peroxisome during desiccation tolerance and energy metabolism.


Assuntos
Ácido Abscísico/farmacologia , Bromus/metabolismo , Temperatura Baixa , Desastres , Peroxissomos/metabolismo , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Northern Blotting , Southern Blotting , Western Blotting , Bromus/embriologia , DNA Complementar , Imuno-Histoquímica , Dados de Sequência Molecular , Proteínas de Plantas/química , Proteínas de Plantas/genética , Homologia de Sequência de Aminoácidos
18.
Nat Biotechnol ; 23(8): 1013-7, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15951804

RESUMO

Very long chain polyunsaturated fatty acids (VLCPUFAs) such as arachidonic acid (AA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are valuable commodities that provide important human health benefits. We report the transgenic production of significant amounts of AA and EPA in Brassica juncea seeds via a stepwise metabolic engineering strategy. Using a series of transformations with increasing numbers of transgenes, we demonstrate the incremental production of VLCPUFAs, achieving AA levels of up to 25% and EPA levels of up to 15% of total seed fatty acids. Both fatty acids were almost exclusively found in triacylglycerols, with AA located preferentially at sn-2 and sn-3 positions and EPA distributed almost equally at all three positions. Moreover, we reconstituted the DHA biosynthetic pathway in plant seeds, demonstrating the practical feasibility of large-scale production of this important omega-3 fatty acid in oilseed crops.


Assuntos
Ácidos Graxos Insaturados/biossíntese , Engenharia Genética/métodos , Mostardeira/genética , Mostardeira/metabolismo , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Sementes/genética , Sementes/metabolismo , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/genética , Modelos Biológicos , Peso Molecular , Proteínas de Plantas/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
19.
J Plant Physiol ; 161(4): 449-58, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15128032

RESUMO

The objective was to investigate the expression of a lipid transfer protein gene (LTP) both in bromegrass (Bromus inermis) cells and seedlings after exposure to abiotic stresses, abscisic acid (ABA), anisomycin, and sphingosine. A full-length cDNA clone BG-14 isolated from bromegrass suspension cell culture encodes a polypeptide of 124 amino acids with typical LTP characteristics, such as a conserved arrangement of cysteine residues. During active stages of cold acclimation LTP expression was up-regulated, whereas at the final stage of cold acclimation LTP transcript level declined to pre-acclimation level. A severe drought stress induced the LTP gene; yet, LTP expression doubled 3 d after re-hydration. Both temperature and heat shock duration influence LTP induction; however temperature is the primary factor. Treatment with NaCl stimulated accumulation of LTP mRNA within 15 min and the transcripts remained at elevated levels for the duration of the salinity stress. Most interestingly, Northern blots showed LTP was rapidly induced not only by ABA, but also by anisomycin and sphingosine in suspension cell cultures. Of the three chemicals, ABA induced the most rapid and highest response in LTP expression as well as highest freezing tolerance, whereas sphingosine was the least active for both LTP expression and freezing tolerance.


Assuntos
Ácido Abscísico/farmacologia , Anisomicina/farmacologia , Bromus/genética , Proteínas de Transporte/genética , Esfingosina/farmacologia , Aclimatação/fisiologia , Antígenos de Plantas , Bromus/efeitos dos fármacos , Bromus/metabolismo , Proteínas de Transporte/metabolismo , Temperatura Baixa , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Temperatura Alta , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Cloreto de Sódio/farmacologia , Estresse Mecânico , Água/farmacologia
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