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1.
Nature ; 618(7967): 1017-1023, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37316672

RESUMO

The discovery and application of genome editing introduced a new era of plant breeding by giving researchers efficient tools for the precise engineering of crop genomes1. Here we demonstrate the power of genome editing for engineering broad-spectrum disease resistance in rice (Oryza sativa). We first isolated a lesion mimic mutant (LMM) from a mutagenized rice population. We then demonstrated that a 29-base-pair deletion in a gene we named RESISTANCE TO BLAST1 (RBL1) caused broad-spectrum disease resistance and showed that this mutation caused an approximately 20-fold reduction in yield. RBL1 encodes a cytidine diphosphate diacylglycerol synthase that is required for phospholipid biosynthesis2. Mutation of RBL1 results in reduced levels of phosphatidylinositol and its derivative phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2). In rice, PtdIns(4,5)P2 is enriched in cellular structures that are specifically associated with effector secretion and fungal infection, suggesting that it has a role as a disease-susceptibility factor3. By using targeted genome editing, we obtained an allele of RBL1, named RBL1Δ12, which confers broad-spectrum disease resistance but does not decrease yield in a model rice variety, as assessed in small-scale field trials. Our study has demonstrated the benefits of editing an LMM gene, a strategy relevant to diverse LMM genes and crops.


Assuntos
Diacilglicerol Colinofosfotransferase , Resistência à Doença , Edição de Genes , Oryza , Melhoramento Vegetal , Doenças das Plantas , Resistência à Doença/genética , Edição de Genes/métodos , Genoma de Planta/genética , Oryza/enzimologia , Oryza/genética , Oryza/microbiologia , Fosfatidilinositóis/metabolismo , Melhoramento Vegetal/métodos , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Alelos , Fosfatidilinositol 4,5-Difosfato/metabolismo , Diacilglicerol Colinofosfotransferase/genética , Diacilglicerol Colinofosfotransferase/metabolismo
2.
N Engl J Med ; 391(1): 56-59, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38959481

RESUMO

Hereditary angioedema is a potentially life-threatening autosomal dominant condition, causing attacks of angioedema due to failure to regulate bradykinin. Nearly all cases of hereditary angioedema are caused by mutations in the gene encoding C1 inhibitor, SERPING1. C1 inhibitor is a multifunctional protein produced in the liver that regulates the kallikrein-kinin system at multiple points. An infant with genetically confirmed hereditary angioedema and low C1 inhibitor levels (but without previous episodes of angioedema) underwent liver transplantation for biliary atresia, an unrelated condition. Liver transplantation led to normalization of the C1 inhibitor level and function. To our knowledge, this represents the first patient to be potentially cured of hereditary angioedema.


Assuntos
Angioedemas Hereditários , Proteína Inibidora do Complemento C1 , Transplante de Fígado , Humanos , Proteína Inibidora do Complemento C1/uso terapêutico , Angioedemas Hereditários/tratamento farmacológico , Angioedemas Hereditários/complicações , Angioedemas Hereditários/genética , Lactente , Masculino , Feminino
3.
Proc Natl Acad Sci U S A ; 119(8)2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35131901

RESUMO

In this article, we describe the development of the plant immunity field, starting with efforts to understand the genetic basis for disease resistance, which ∼30 y ago led to the discovery of diverse classes of immune receptors that recognize and respond to infectious microbes. We focus on knowledge gained from studies of the rice XA21 immune receptor that recognizes RaxX (required for activation of XA21 mediated immunity X), a sulfated microbial peptide secreted by the gram-negative bacterium Xanthomonas oryzae pv. oryzae. XA21 is representative of a large class of plant and animal immune receptors that recognize and respond to conserved microbial molecules. We highlight the complexity of this large class of receptors in plants, discuss a possible role for RaxX in Xanthomonas biology, and draw attention to the important role of sulfotyrosine in mediating receptor-ligand interactions.


Assuntos
Resistência à Doença/imunologia , Oryza/imunologia , Proteínas de Plantas/imunologia , Proteínas Serina-Treonina Quinases/imunologia , Agricultura/história , Alergia e Imunologia/história , Alergia e Imunologia/tendências , Infecções Bacterianas/genética , Proteínas de Bactérias/genética , Resistência à Doença/genética , História do Século XIX , História do Século XX , História do Século XXI , Peptídeos/química , Doenças das Plantas/microbiologia , Imunidade Vegetal/imunologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo
4.
Clin Exp Immunol ; 217(1): 109-116, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38456386

RESUMO

Hereditary angioedema (HAE) is a rare inherited disorder causing recurrent episodes of swelling that can be potentially life threatening. Treatment of HAE can be divided into on-demand treatment for swelling, and prophylaxis. The last UK consensus on HAE was in 2014 and since then, new medications for prophylaxis have been developed, with more drugs in the pipeline. International guidelines currently recommend the use of long-term prophylaxis (LTP) as the only way of achieving disease control and normalizing patient lives. Modern prophylactic medications are available in the UK, although access is restricted primarily by HAE attack frequency. To establish an updated view of UK clinicians and patients, a Delphi process was used to develop statements regarding LTP as well as other aspects of HAE management. There was consensus that UK access criteria for modern LTP agents based on numerical frequency of attacks alone are too simplistic and potentially disadvantage a cohort of patients who may benefit from LTP. Additionally, there was agreement that patients should be seen in expert centres, remote monitoring of patients is popular post-pandemic, and that the use of patient-reported outcome measures has the potential to improve patient care. Psychological health is an area in which patients may benefit, and recognition of this is important for future research and development.


Assuntos
Angioedemas Hereditários , Consenso , Técnica Delphi , Humanos , Angioedemas Hereditários/prevenção & controle , Angioedemas Hereditários/tratamento farmacológico , Reino Unido , Proteína Inibidora do Complemento C1/uso terapêutico
5.
Clin Transplant ; 38(1): e15165, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37837612

RESUMO

BACKGROUND: The use of bortezomib which is a proteasome inhibitor has been demonstrated to be efficacious in small number of patients as a desensitization strategy in heart transplant. We reviewed our single center's experience using Bortezomib along with plasmapheresis as desensitization therapy for highly sensitized patients to assess pre- and post-transplant outcomes. METHOD: We assessed 43 highly sensitized patients awaiting HTx (defined as cPRA > 50%) between 2010 and 2021 who underwent desensitization therapy with bortezomib. Only those patients who subsequently underwent HTx were included in this study. Enrolled patients received up to four doses of bortezomib (1.3 mg/m2 ) over 2 weeks in conjunction with plasmapheresis. The efficacy of PP/BTZ was assessed by comparing the calculated panel reactive antibodies to HLA class I or class II antigens. Post-transplant outcomes including overall survival and incidence of rejection were compared to those of non-sensitized patients (PRA < 10%, n = 649) from the same center. RESULTS: The average cPRA prior to PP/BTZ was 94.5%. Post-PP/BTZ there was no statistically significant decline in mean cPRA, class I cPRA, or class II cPRA, though the average percentage decrease in class I cPRA (8.7 ± 17.0%) was higher than the change in class II cPRA (4.4 ± 13.3%). Resulted were also replicated with C1q-binding antibodies showing more effect on I class compared to class II (15.0 ± 37.4% vs. 6.8 ± 33.6%) as well as with 1:8 dilutional assay (14.0 ± 23.0% vs. 9.1 ± 34.9%). Additionally, PP/BTZ treated patients and the control group of non-sensitized patients had similar overall 1 year survival (95.4 vs. 92.5%) but patients with PP/BTZ had increased incidence of AMR (79.1% vs. 97.1%, p = < .001), any treated rejection (62.8% vs. 86.7%, p = < .001) and de novo DSA development (81.4% vs. 92.5%, p = .007). Major side effects of PP/BTZ included thrombocytopenia (42%), infection requiring antibiotics (28%), and neuropathy (12%). CONCLUSION: The use of bortezomib in highly sensitized patients does not significantly lower circulating antibodies prior to heart transplantation. However, its use may improve the chances of obtaining an immuno-compatible donor heart and contribute to acceptable post-transplant outcomes.


Assuntos
Transplante de Coração , Humanos , Bortezomib/uso terapêutico , Isoanticorpos , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/etiologia , Doadores de Tecidos , Antígenos HLA , Dessensibilização Imunológica
6.
Proc Natl Acad Sci U S A ; 118(8)2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33608460

RESUMO

Early root growth is critical for plant establishment and survival. We have identified a molecular pathway required for helical root tip movement known as circumnutation. Here, we report a multiscale investigation of the regulation and function of this phenomenon. We identify key cell signaling events comprising interaction of the ethylene, cytokinin, and auxin hormone signaling pathways. We identify the gene Oryza sativa histidine kinase-1 (HK1) as well as the auxin influx carrier gene OsAUX1 as essential regulators of this process in rice. Robophysical modeling and growth challenge experiments indicate circumnutation is critical for seedling establishment in rocky soil, consistent with the long-standing hypothesis that root circumnutation facilitates growth past obstacles. Thus, the integration of robotics, physics, and biology has elucidated the functional importance of root circumnutation and uncovered the molecular mechanisms underlying its regulation.


Assuntos
Regulação da Expressão Gênica de Plantas , Histidina Quinase/metabolismo , Ácidos Indolacéticos/farmacologia , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Solo/química , Transporte Biológico , Citocininas/metabolismo , Histidina Quinase/genética , Oryza/efeitos dos fármacos , Oryza/genética , Oryza/metabolismo , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/metabolismo
7.
Curr Heart Fail Rep ; 21(2): 139-146, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38231443

RESUMO

PURPOSE OF REVIEW: This review describes management practices, outcomes, and allocation policies in candidates for simultaneous heart-kidney transplantation (SHKT). RECENT FINDINGS: In patients with heart failure and concomitant kidney disease, SHKT confers a survival advantage over heart transplantation (HT) alone in patients with dialysis dependence or an estimated glomerular filtration rate (eGFR) < 40 mL/min/1.73 m2. However, when compared to kidney transplantation (KT) alone, SHKT is associated with worse patient and kidney allograft survival. In September 2023, the United Network of Organ Sharing adopted a new organ allocation policy, with strict eligibility criteria for SHKT and a safety net for patients requiring KT after HT alone. While the impact of the policy change on SHKT outcomes remains to be seen, strategies to prevent and slow development of kidney disease in patients with heart failure and to prevent kidney dysfunction after HT and SHKT are necessary.


Assuntos
Insuficiência Cardíaca , Transplante de Coração , Nefropatias , Transplante de Rim , Humanos , Insuficiência Cardíaca/cirurgia , Insuficiência Cardíaca/complicações , Rim , Nefropatias/complicações
8.
Plant J ; 110(3): 646-657, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35106860

RESUMO

The rice immune receptor XA21 confers resistance to Xanthomonas oryzae pv. oryzae (Xoo), and upon recognition of the RaxX21-sY peptide produced by Xoo, XA21 activates the plant immune response. Here we screened 21 000 mutant plants expressing XA21 to identify components involved in this response, and reported here the identification of a rice mutant, sxi4, which is susceptible to Xoo. The sxi4 mutant carries a 32-kb translocation from chromosome 3 onto chromosome 7 and displays an elevated level of DCL2a transcript, encoding a Dicer-like protein. Silencing of DCL2a in the sxi4 genetic background restores resistance to Xoo. RaxX21-sY peptide-treated leaves of sxi4 retain the hallmarks of XA21-mediated immune response. However, WRKY45-1, a known negative regulator of rice resistance to Xoo, is induced in the sxi4 mutant in response to RaxX21-sY peptide treatment. A CRISPR knockout of a short interfering RNA (TE-siRNA815) in the intron of WRKY45-1 restores the resistance phenotype in sxi4. These results suggest a model where DCL2a accumulation negatively regulates XA21-mediated immunity by altering the processing of TE-siRNA815.


Assuntos
Oryza , Xanthomonas , Oryza/metabolismo , Peptídeos/metabolismo , Fenótipo , Doenças das Plantas/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Serina-Treonina Quinases/genética , Xanthomonas/metabolismo
9.
Clin Immunol ; 236: 108938, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35121105

RESUMO

Many patients with immunodeficiencies require lifelong immunoglobulin replacement therapy (IgRT). In a multicenter, randomized, open-label, crossover, non-inferiority 3-month-trial, we compared the impact of the subcutaneous immunoglobulin Gammanorm® administered via pump or syringe (rapid push). Primary endpoint was the life quality index (LQI), secondary endpoints were QoL (SF36v2), satisfaction (TSQM-11), disease and treatment burden (PRISM), incidence of infections and adverse events (AE), treatment costs, and IgG levels. 28/30 patients completed the study. Most of the endpoints were comparable. Drug administrations with rapid push were more frequent, but reduced total time expenditure and some costs. Of the TSQM-11/LQI/SF36 components only "treatment interference with daily activities" was superior with pump and two QoL domains with rapid push. Both delivery devices showed favorable safety. Rapid push was preferred by 34.5% of patients. It proved to be an efficacious and cost-effective alternative to pumps adding to patient choice and increasing flexibility during long-term IgRT.


Assuntos
Síndromes de Imunodeficiência , Qualidade de Vida , Adulto , Humanos , Imunização Passiva , Imunoglobulina G , Síndromes de Imunodeficiência/terapia , Infusões Subcutâneas
10.
Clin Exp Immunol ; 209(3): 247-258, 2022 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-35641155

RESUMO

In March 2020, the United Kingdom Primary Immunodeficiency Network (UKPIN) established a registry of cases to collate the outcomes of individuals with PID and SID following SARS-CoV-2 infection and treatment. A total of 310 cases of SARS-CoV-2 infection in individuals with PID or SID have now been reported in the UK. The overall mortality within the cohort was 17.7% (n = 55/310). Individuals with CVID demonstrated an infection fatality rate (IFR) of 18.3% (n = 17/93), individuals with PID receiving IgRT had an IFR of 16.3% (n = 26/159) and individuals with SID, an IFR of 27.2% (n = 25/92). Individuals with PID and SID had higher inpatient mortality and died at a younger age than the general population. Increasing age, low pre-SARS-CoV-2 infection lymphocyte count and the presence of common co-morbidities increased the risk of mortality in PID. Access to specific COVID-19 treatments in this cohort was limited: only 22.9% (n = 33/144) of patients admitted to the hospital received dexamethasone, remdesivir, an anti-SARS-CoV-2 antibody-based therapeutic (e.g. REGN-COV2 or convalescent plasma) or tocilizumab as a monotherapy or in combination. Dexamethasone, remdesivir, and anti-SARS-CoV-2 antibody-based therapeutics appeared efficacious in PID and SID. Compared to the general population, individuals with PID or SID are at high risk of mortality following SARS-CoV-2 infection. Increasing age, low baseline lymphocyte count, and the presence of co-morbidities are additional risk factors for poor outcome in this cohort.


Assuntos
Tratamento Farmacológico da COVID-19 , COVID-19 , Síndromes de Imunodeficiência , Humanos , Anticorpos Monoclonais Humanizados , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/terapia , Soroterapia para COVID-19 , Dexametasona , Combinação de Medicamentos , Imunização Passiva , SARS-CoV-2 , Reino Unido/epidemiologia
11.
Clin Transplant ; 35(11): e14449, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34363421

RESUMO

BACKGROUND: Conditional survival (CS) is a dynamic method of survival analysis that provides an estimate of how an individual's future survival probability changes based on time post-transplant, individual characteristics, and post-transplant events. This study sought to provide post-transplant CS probabilities for heart transplant recipients based on different prognostic variables and provide a discussion tool for the providers and the patients. METHODS: Adult heart transplant recipients from January 1, 2004, through October 18, 2018, were identified in the UNOS registry. CS probabilities were calculated using data from Kaplan-Meier survival estimates. RESULTS: CS probability exceeded actuarial survival probability at all times post-transplant. Women had similar short-term, but greater long-term CS than men at all times post-transplant (10-year CS 1.8-11.5% greater [95% CI 1.2-12.9]). Patients with ECMO or a surgical BiVAD had decreased survival at the time of transplant, but their CS was indistinguishable from all others by 1-year post-transplant. Rejection and infection requiring hospitalization during the first year were associated with a persistently decreased CS probability. CONCLUSIONS: In this study, we report differential conditional survival outcomes based on time, patient characteristics, and clinical events post-transplant, providing a dynamic assessment of survival. The survival probabilities will better inform patients and clinicians of future outcomes.


Assuntos
Transplante de Coração , Obtenção de Tecidos e Órgãos , Adulto , Feminino , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto , Humanos , Estimativa de Kaplan-Meier , Masculino , Sistema de Registros , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
12.
Funct Integr Genomics ; 20(4): 509-522, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31925598

RESUMO

MicroRNAs lie at the core of biological regulatory networks in plants. The recent discovery of isomiRs that are length variants of the annotated mature miRNAs has further unveiled the complexity of miRNome. Delineation of their functional relevance is critical to understand the complete functional spectrum of the miRNome. To apprehend the role of 5' isomiRs in rice, we performed a comprehensive analysis of the annotated miRNA pool using 8 deep-sequencing datasets from flag leaf and spikelet tissues from two cultivars of rice viz. N22 and PB1 grown under control and drought conditions. The products of the 5' start site variability termed as "5' isomiRs" were found to be widespread in all the datasets. It was possible to identify several 5' isomiRs that were highly distinct and abundant and supported by more than 90% of the tags that map in the region. Majority of miRNA/5' isomiR pair share similar tissue and drought-mediated expression dynamics. Analysis of the degradome data identified targets for several of these 5' isomiRs, thereby confirming their biological activity. Since the isomiRs are length variants at the 5' end, the target sites were found to be accordingly shifted as compared to the target site of the annotated miRNA. Further we also observed that drought affects the processing accuracy of several miRNAs across all tissues of both the cultivars leading to differential accumulation of 5' isomiR/miRNA pair.


Assuntos
Secas , MicroRNAs/genética , Oryza/genética , Processamento Pós-Transcricional do RNA , Regulação da Expressão Gênica de Plantas , MicroRNAs/metabolismo , Oryza/metabolismo , Estresse Fisiológico
13.
J Card Fail ; 26(4): 287-297, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31618696

RESUMO

BACKGROUND: Obesity remains a relative contraindication for heart transplantation, and hence, obese patients with advanced heart failure receive ventricular assist devices (VADs) either as a destination or "bridge to weight loss" strategy. However, impact of obesity on clinical outcomes after VAD implantation is largely unknown. We sought to determine the clinical outcomes of obese patients with body mass index (BMI) ≥ 35 kg/m2) following contemporary VAD implantation. METHODS: The Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) registry was queried for patients who underwent VAD implantation. Patients were categorized into BMI groups based on World Health Organization classification. RESULTS: Of 17,095 patients, 2620 (15%) had a BMI ≥ 35 kg/m2. Obese patients were likely to be young, non-white, females with dilated cardiomyopathy and undergo device implantation as destination. Survival was similar amongst BMI groups (P = .058). Obese patients had significantly higher risk for infection (hazard ratio [HR]: 1.215; P = .001), device malfunction or thrombosis (HR: 1.323; P ≤ .001), cardiac arrhythmia (HR: 1.188; P = .001) and hospital readmissions (HR: 1.073; P = .022), but lower risk of bleeding (HR: 0.906; P = .018). Significant weight loss (≥10%) during VAD support was achieved only by a small proportion (18.6%) of patients with BMI ≥ 35 kg/m2. Significant weight loss rates observed in obese patients with VAD implantation as destination and bridge to transplant strategy were comparable. Obese patients with significant weight loss were more likely to undergo cardiac transplantation. Weight loss worsened bleeding risk without altering risk for infection, cardiac arrhythmia, and device complications. CONCLUSIONS: Obesity alone should not be considered a contraindication for VAD therapy in contemporary era. Given durability of heart transplantation, strategies should be developed to promote weight loss, which occurs infrequently in obese patients. Impact of weight loss on clinical outcome of obese patients warrants further investigation.


Assuntos
Insuficiência Cardíaca , Transplante de Coração , Coração Auxiliar , Feminino , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/terapia , Humanos , Obesidade/complicações , Obesidade/epidemiologia , Sistema de Registros , Estudos Retrospectivos , Resultado do Tratamento
14.
Plant Cell ; 29(6): 1218-1231, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28576844

RESUMO

The availability of a whole-genome sequenced mutant population and the cataloging of mutations of each line at a single-nucleotide resolution facilitate functional genomic analysis. To this end, we generated and sequenced a fast-neutron-induced mutant population in the model rice cultivar Kitaake (Oryza sativa ssp japonica), which completes its life cycle in 9 weeks. We sequenced 1504 mutant lines at 45-fold coverage and identified 91,513 mutations affecting 32,307 genes, i.e., 58% of all rice genes. We detected an average of 61 mutations per line. Mutation types include single-base substitutions, deletions, insertions, inversions, translocations, and tandem duplications. We observed a high proportion of loss-of-function mutations. We identified an inversion affecting a single gene as the causative mutation for the short-grain phenotype in one mutant line. This result reveals the usefulness of the resource for efficient, cost-effective identification of genes conferring specific phenotypes. To facilitate public access to this genetic resource, we established an open access database called KitBase that provides access to sequence data and seed stocks. This population complements other available mutant collections and gene-editing technologies. This work demonstrates how inexpensive next-generation sequencing can be applied to generate a high-density catalog of mutations.


Assuntos
Genoma de Planta/genética , Genômica/métodos , Oryza/genética , DNA de Plantas/genética , Mutação/genética , Análise de Sequência de DNA
15.
Langmuir ; 36(4): 1003-1013, 2020 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-31865708

RESUMO

Collagen, the most abundant component of natural ECM, has attracted interest of scientific communities to replicate its multihierarchical self-assembling structure. Recent developments in collagen mimetic peptides were inclined toward the production of self-assembling short peptides capable of mimicking complex higher order structures with tunable mechanical properties. Here, we report for the first time, the crucial molecular design of oppositely charged collagen mimetic shortest bioactive pentapeptide sequences, as a minimalistic building block for development of next-generation biomaterials. Our rational design involves synthesis of two pentapeptides, where the fundamental molecular motif of collagen, that is, Gly-X-Y has been mutated at the central position with positively charged, lysine, and negatively charged, aspartate, residues. Depending on their overall surface charge, these peptides showed high propensity to form self-supporting hydrogel either at acidic or basic pH, which limits their biomedical applications. Interestingly, simple mixing of the two peptides was found to induce the coassembly of these designed peptides, which drives the formation of self-supporting hydrogel at physiological pH and thus enhanced the potential of exploring these peptides for biomedical purposes. This coassembly of ionic peptides was accompanied by the enhancement in the mechanical stiffness of the gels and reduction in overall zeta potential of the combined hydrogel, which provides the evidence for additional electrostatic interactions. Furthermore, the thixotropic nature of these gels offers an additional advantage of exploration of designer biomaterials as injectable gels. The nanofibers of coassembled hydrogel were found to be highly biocompatible to the fibroblast cells compared to the individual peptides, which was evident from their cytotoxicity studies. We anticipate that our rational design of ECM protein mimics in the form of short bioactive peptides will contribute significantly to the development of novel biomaterials and play a crucial role in the field of tissue engineering and regenerative medicines.


Assuntos
Colágeno/química , Peptídeos/química , Hidrogel de Polietilenoglicol-Dimetacrilato , Concentração de Íons de Hidrogênio , Íons/química , Substâncias Macromoleculares/química , Espectrometria de Massas , Estrutura Molecular , Peptídeos/síntese química , Eletricidade Estática
16.
Biomacromolecules ; 21(10): 4180-4193, 2020 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-32786522

RESUMO

In recent years, the molecular self-assembly approach has witnessed a sudden surge in coassembly strategy to achieve extensive control over accessing diverse nanostructures and functions. To this direction, peptide-peptide coassembly has been explored to some extent in the literature, but protein-peptide coassembly is still in its infancy for controlling the self-assembling properties. To the best of our knowledge, our study illustrated the merits of protein-peptide coassembly toward inducing gelation to a nongelator dipeptide sequence, for the first time. This simplistic approach could provide access to diverse mechanical and structural properties within a single gelator domain at identical concentrations with a simple variation in the protein concentrations. Interestingly, the protein-peptide interactions could transform aggregate-like structures into fibrillar nanostructures. The study attempts to provide the proof of concept for the nonspecific protein-peptide interactions purely based on simple noncovalent interactions. The range of dissociation constants and binding energies obtained from bioloyer interferometry and docking studies confirmed the involvement of noncovalent interactions in protein-peptide coassembly, which triggers gelation. Moreover, different binding affinities of a protein toward an individual peptide essentially demonstrated a route to achieve precise control over differential self-assembling properties. Another important aspect of this study was entrapment of an enzyme protein within the gel network during coassembly without inhibiting enzyme activity, which can serve as a scaffold for catalytic reactions. The present study highlights the nonconventional way of protein-peptide interactions in triggering self-assembly in a nonassembling precursor. We anticipate that fundamental insights into the intermolecular interactions would lead to novel binary supramolecular hydrogels that can be developed as a next generation biomaterial for various biomedical applications.


Assuntos
Nanoestruturas , Peptídeos , Dipeptídeos , Hidrogéis
17.
BMC Genomics ; 20(1): 905, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31775618

RESUMO

BACKGROUND: The availability of thousands of complete rice genome sequences from diverse varieties and accessions has laid the foundation for in-depth exploration of the rice genome. One drawback to these collections is that most of these rice varieties have long life cycles, and/or low transformation efficiencies, which limits their usefulness as model organisms for functional genomics studies. In contrast, the rice variety Kitaake has a rapid life cycle (9 weeks seed to seed) and is easy to transform and propagate. For these reasons, Kitaake has emerged as a model for studies of diverse monocotyledonous species. RESULTS: Here, we report the de novo genome sequencing and analysis of Oryza sativa ssp. japonica variety KitaakeX, a Kitaake plant carrying the rice XA21 immune receptor. Our KitaakeX sequence assembly contains 377.6 Mb, consisting of 33 scaffolds (476 contigs) with a contig N50 of 1.4 Mb. Complementing the assembly are detailed gene annotations of 35,594 protein coding genes. We identified 331,335 genomic variations between KitaakeX and Nipponbare (ssp. japonica), and 2,785,991 variations between KitaakeX and Zhenshan97 (ssp. indica). We also compared Kitaake resequencing reads to the KitaakeX assembly and identified 219 small variations. The high-quality genome of the model rice plant KitaakeX will accelerate rice functional genomics. CONCLUSIONS: The high quality, de novo assembly of the KitaakeX genome will serve as a useful reference genome for rice and will accelerate functional genomics studies of rice and other species.


Assuntos
Genoma de Planta , Genômica , Oryza/genética , Sequenciamento Completo do Genoma , Biologia Computacional/métodos , Variação Genética , Genômica/métodos , Anotação de Sequência Molecular , Oryza/classificação , Fenótipo
18.
Langmuir ; 35(17): 5878-5889, 2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-30916565

RESUMO

The fundamental understanding of the detailed relationship between molecular structure and material function remains a challenging task, until now. In order to understand the relative contribution of aromatic moieties and hydrophobicity of amino acid chains, we designed a library of ultrashort amyloid-like peptides based on Ar-Phe-X (where "Ar" represents different aromatic moieties and "X" represents amino acids having varied side-chain functionalities). Our research clearly indicated that the alteration in the size and hydrophobicity of the aromatic capping play a crucial role compared to the subtle change in the amino acid sequence of the dipeptide in dictating the final self-assembled structure and properties of these short peptide amphiphiles. Further, we explored our detailed understanding toward the controlled synthesis of bioinspired organic-inorganic hybrids. For the first time, we established the differential role of aliphatic and aromatic hydroxyl moieties toward the in situ shape-controlled synthesis of gold nanoparticles in three-dimensional nanostructures of hydrogels. To the best of our knowledge, it is the first report which demonstrated the formation of rectangular platonic gold nanoparticles using simple dipeptide hydrogels, exhibiting pH-dependent size control. Our study shows promising implications in bottom-up nanofabrication of next-generation nanomaterials with emergent properties.


Assuntos
Proteínas Amiloidogênicas/química , Dipeptídeos/química , Hidrogéis/química , Nanopartículas Metálicas/química , Proteínas Amiloidogênicas/síntese química , Dipeptídeos/síntese química , Ouro/química , Interações Hidrofóbicas e Hidrofílicas , Estrutura Molecular , Multimerização Proteica , Reologia
20.
PLoS Genet ; 12(5): e1006049, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27176732

RESUMO

Systemic acquired resistance, mediated by the Arabidopsis NPR1 gene and the rice NH1 gene, confers broad-spectrum immunity to diverse pathogens. NPR1 and NH1 interact with TGA transcription factors to activate downstream defense genes. Despite the importance of this defense response, the signaling components downstream of NPR1/NH1 and TGA proteins are poorly defined. Here we report the identification of a rice mutant, snim1, which suppresses NH1-mediated immunity and demonstrate that two genes encoding previously uncharacterized cysteine-rich-receptor-like kinases (CRK6 and CRK10), complement the snim1 mutant phenotype. Silencing of CRK6 and CRK10 genes individually in the parental genetic background recreates the snim1 phenotype. We identified a rice mutant in the Kitaake genetic background with a frameshift mutation in crk10; this mutant also displays a compromised immune response highlighting the important role of crk10. We also show that elevated levels of NH1 expression lead to enhanced CRK10 expression and that the rice TGA2.1 protein binds to the CRK10 promoter. These experiments demonstrate a requirement for CRKs in NH1-mediated immunity and establish a molecular link between NH1 and induction of CRK10 expression.


Assuntos
Proteínas de Arabidopsis/genética , Oryza/genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Arabidopsis/genética , Cisteína/genética , Regulação da Expressão Gênica de Plantas , Oryza/crescimento & desenvolvimento , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas
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