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1.
Plant Physiol Biochem ; 169: 259-268, 2021 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-34814097

RESUMO

Improving nitrogen use efficiency (NUE) has been a focal point for crop growth and yield throughout the world. Glutamine synthetase (GS), which plays a fundamental role in N metabolism, has been exploited to improve crop NUE. However, increased GS activity in rice by overexpressing its own GS genes hasn't shown superior plant productivity. Here, transgenic rice plants with increased GS activity by overexpressing TaGS1 were analyzed under field and culture conditions at two N rates. Transgenic expression of TaGS1 significantly increases GS activity in leaves, junctions and roots of rice plants relative to wide-type plants. When rice plants grown under consecutive field trials with N rates of 60 and 240 kg/ha, three transgenic lines have higher grain yield than wild-type plants, with increment of 15%-22% in T2 generation and with that of 28%-36% in T3 generation, respectively. And increased panicle numbers (effective tiller numbers) mainly contribute to the advantage of grain yield in transgenic plants. Analysis of N use-related traits shows that transgenic plants with enhanced GS activity promote root capacity to obtain N, N accumulation during growth stages and N remobilization to grains, ultimately conferring 31%-40% improvement of NUE relative to wild-type rice plants.

2.
Plant Cell Environ ; 2021 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-34713922

RESUMO

Most land plants can establish symbiosis with arbuscular mycorrhizal (AM) fungi to increase fitness to environmental challenges. The development of AM symbiosis is controlled by intricate procedures involving all phytohormones. However, the mechanisms underlying the auxin-mediated regulation of AM symbiosis remains largely unknown. Here, we report that AM colonisation promotes auxin response and indole-3-acetic acid (IAA) accumulation, but downregulates IAA biosynthesis genes in tomato (Solanum lycopersicum). External IAA application modulates the AM symbiosis by promoting arbuscule formation at low concentrations but repressing it at high concentrations. An AM-induced GH3 gene, SlGH3.4, encoding a putative IAA-amido synthetase, negatively regulates mycorrhization via maintaining cellular auxin homoeostasis. Loss of SlGH3.4 function increased free IAA content and arbuscule incidence, while constitutively overexpressing SlGH3.4 in either tomato or rice resulted in decreased IAA content, total colonisation level and arbuscule abundance in mycorrhizal roots. Several auxin-inducible expansin genes involved in AM formation or resistance to pathogen infection were upregulated in slgh3.4 mycorrhizal roots but downregulated in the SlGH3.4-overexpressing plants. Taken together, our results highlight a positive correlation between the endogenous IAA content and mycorrhization level, particularly arbuscule incidence, and suggest that the SlGH3.4-mediated auxin homoeostasis and regulation of expansin genes is involved in finely tuning the AM development.

3.
BMC Musculoskelet Disord ; 22(1): 818, 2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34556093

RESUMO

BACKGROUND: Fibrosis is an important factor and process of ligamentum flavum hypertrophy. The expression of phosphodiesterase family (PDE) is related to inflammation and fibrosis. This article studied the expression of PDE in hypertrophic ligamentum flavum fibroblasts and investigated whether inhibition of PDE4 activity can play an anti-fibrotic effect. METHODS: Samples of clinical hypertrophic ligamentum flavum were collected and patients with lumbar disc herniations as a control group. The collagenase digestion method is used to separate fibroblasts. qPCR is used to detect the expression of PDE subtypes, type I collagen (Col I), type III collagen (Col III), fibronectin (FN1) and transforming growth factor ß1 (TGF-ß1). Recombinant TGF-ß1 was used to stimulate fibroblasts to make a fibrotic cell model and treated with Rolipram. The morphology of the cells treated with drugs was observed by Sirius Red staining. Scratch the cells to observe their migration and proliferation. WB detects the expression of the above-mentioned multiple fibrotic proteins after drug treatment. Finally, combined with a variety of signaling pathway drugs, the signaling mechanism was studied. RESULTS: Multiple PDE subtypes were expressed in ligamentum flavum fibroblasts. The expression of PDE4A and 4B was significantly up-regulated in the hypertrophic group. Using Rolipram to inhibit PDE4 activity, the expression of Col I and TGF-ß1 in the hypertrophic group was inhibited. Col I recovered to the level of the control group. TGF-ß1 was significantly inhibited, which was lower than the control group. Recombinant TGF-ß1 stimulated fibroblasts to increase the expression of Col I/III, FN1 and TGF-ß1, which was blocked by Rolipram. Rolipram restored the increased expression of p-ERK1/2 stimulated by TGF-ß1. CONCLUSION: The expressions of PDE4A and 4B in the hypertrophic ligamentum flavum are increased, suggesting that it is related to the hypertrophy of the ligamentum flavum. Rolipram has a good anti-fibrosis effect after inhibiting the activity of PDE4. This is related to blocking the function of TGF-ß1, specifically by restoring normal ERK1/2 signal.


Assuntos
Ligamento Amarelo , Fibroblastos/metabolismo , Fibrose , Humanos , Ligamento Amarelo/patologia , Sistema de Sinalização das MAP Quinases , Rolipram/metabolismo , Rolipram/farmacologia , Fator de Crescimento Transformador beta1/metabolismo
4.
Plant Signal Behav ; 16(11): 1976545, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34523389

RESUMO

Phosphorus (P), which is taken up by plants as inorganic phosphate (Pi), is one of the most important macronutrients for plant growth and development. Meanwhile, it determines plant architecture in several ways, including leaf inclination. However, the molecular basis underlying the crosstalk between the signaling pathways of plant P homeostasis and architecture maintenance remains elusive. We recently characterized a WRKY transcription factor, OsWRKY108, in rice (Oryza sativa). It functions redundantly with OsWRKY21 to promote Pi uptake in response to Pi supply. Overexpression of either OsWRKY108 or OsWRKY21 led to up-regulation of Pi transporter genes and thus enhanced Pi accumulation. By contrast, transgenic rice plants expressing OsWRKY21-SRDX (a fusion protein transforming OsWRKY21 from an activator into a dominant repressor) but not the OsWRKY108-SRDX fusion showed decreased Pi accumulation under Pi-replete conditions. Here, we report that OsWRKY108 acts as a positive regulator of leaf inclination. OsWRKY108 overexpressors showed increased leaf inclination and OsWRKY108-SRDX plants showed an erect-leaf phenotype, irrespective of the Pi regimes. Nevertheless, the response of leaf inclination to Pi starvation was largely impaired upon OsWRKY108 overexpression. Moreover, in both OsWRKY108-SRDX plants and OsWRKY108 overexpressors, the 'percentage of leaf angle alteration relative to wild-type' under Pi-starvation condition was more significant than that under Pi-replete condition. These results suggest that the regulation of OsWRKY108 on leaf inclination is in part dependent on Pi availability. Altogether, our findings demonstrate that OsWRKY108 is an integrative regulator of P homeostasis and leaf inclination, serving as a link between plant nutrient signaling and developmental cues.

5.
Br J Neurosurg ; : 1-8, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34524042

RESUMO

OBJECTIVE: This retrospective study investigated the clinical and radiographic outcomes following temporary transpedicular posterior instrumentation between two cohorts of patients with thoracolumbar fractures (TLF) who underwent selective or bi-segments intervertebral articular process fusion. METHODS: Patients with TLF who underwent the temporary posterior fixation with selective fusion (Group SF), or bi-segments fusion (Group BF) were studied. Superior intervertebral articular process and interlaminar fusion were performed in Group SF, whereas in Group BF, the patients underwent bi-segments fusion in both superior and inferior articular processes, as well as interlaminar fusion. We measured the distal and proximal intervertebral mobility, regional kyphotic angle, and vertebral height before and after surgery in both groups. Greenough Low-Back Outcome Score was used to assess the clinical outcomes. RESULTS: Sixty-five patients with TLF from T12 to L2 fractures were enrolled in the study period: 33 patients in the Group SF and 32 patients in the Group BF. All the patients experienced fracture healing (mean follow-up time: 19.7 months). The mean postoperative functional outcomes were 65.0 ± 2.0 points for the Low-Back Outcome Score in the Group SF and 65.2 ± 1.8 for the Group BF. A progressive regional kyphotic angle was observed with time regardless of fusion but was not significantly different between the two groups. There was a statistical difference between unfused inferior proximal adjacent and inferior distal adjacent segment regardless of fracture segments. CONCLUSIONS: The strategy of selective fusion is reported to be useful for the treatment of patients with TLF. The motion in the un-fused and adjacent segment could be better regained after instrumentation removal in the selective fusion group. LEVEL OF EVIDENCE: Level 3.

6.
Front Nutr ; 8: 702108, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34504861

RESUMO

Collagen is a kind of biocompatible protein material, which is widely used in medical tissue engineering, drug delivery, cosmetics, food and other fields. Because of its wide source, low extraction cost and good physical and chemical properties, it has attracted the attention of many researchers in recent years. However, the application of collagen derived from terrestrial organisms is limited due to the existence of diseases, religious beliefs and other problems. Therefore, exploring a wider range of sources of collagen has become one of the main topics for researchers. Marine-derived collagen (MDC) stands out because it comes from a variety of sources and avoids issues such as religion. On the one hand, this paper summarized the sources, extraction methods and characteristics of MDC, and on the other hand, it summarized the application of MDC in the above fields. And on the basis of the review, we found that MDC can not only be extracted from marine organisms, but also from the wastes of some marine organisms, such as fish scales. This makes further use of seafood resources and increases the application prospect of MDC.

7.
Oxid Med Cell Longev ; 2021: 6389568, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34394829

RESUMO

Excessive apoptosis and inflammatory responses of nucleus pulposus (NP) cells induced by oxidative stress contribute to intervertebral disc degeneration (IVDD). Though some microRNAs are associated with IVDD, the specific microRNA that can mediate apoptotic and inflammatory responses of NP cells induced by oxidative stress synchronously still needs further identification. Here, we find that microRNA-623 (miR-623) is downregulated in IVDD and its expression is regulated by hypoxia-inducible factor-1α (HIF-1α) under oxidative stress conditions. Mechanistically, HIF-1α is observed to promote miR-623 expression by directly binding to its promoter region (-1,994/-1,987 bp). Functionally, miR-623 is found to work as an intermediator in alleviating apoptosis and inflammatory responses of NP cells induced by oxidative stress via regulating thioredoxin-interacting protein (TXNIP) expression by directly targeting its 3'-untranslated region (3'-UTR). Thus, on elucidating the expression and functional mechanisms of miR-623, our study suggests that miR-623 can be a valuable therapeutic target for treating oxidative stress-induced IVDD.

8.
Plant Physiol Biochem ; 166: 712-722, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34214781

RESUMO

Phosphorus (P) and nitrogen (N) are both essential macronutrients for maintaining plant growth and development. In rice (Oryza sativa L.), OsPHR3 is one of the four paralogs of PHR1, which acts as a central regulator of phosphate (Pi) homeostasis, as well being involved in N homeostasis. However, the functions of OsPHR3 in N utilization under different Pi conditions have yet to be fully studied. In this study, we aimed to dissect the effect of OsPHR3-overexpression on N utilization under Pi deficient regimes. Biochemical, molecular and physiological assays were performed to determine the N-influx, translocation, and accumulation in OsPHR3-overexpressing rice lines, grown under Pi-sufficient and -deficient conditions, in both hydroponic and soil systems. Furthermore, important agronomic traits of these plants were also evaluated. The overexpression of OsPHR3 increased N uptake under Pi stress regimes. Increased N uptake also elevated total N concentrations in these plants by inducing N transporter genes expression. Furthermore, overexpression of OsPHR3 increased N use efficiency, 1000-grain weight and grain yield under different Pi conditions. We established new findings that OsPHR3-overexpression facilitates N utilization under Pi deficient conditions. This will help achieving higher yields by coordinating the utilization of N and P.


Assuntos
Nitrogênio , Oryza , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/metabolismo , Fosfatos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Fatores de Transcrição/genética
9.
Pain Physician ; 24(4): E483-E492, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34213874

RESUMO

BACKGROUND: Selective nerve root block (SNRB) has been used to facilitate the diagnostic process when radiologic abnormalities are not correlated with clinical symptomatology in patients with cervical radiculopathy. Meanwhile, minimally invasive posterior percutaneous endoscopic cervical foraminotomy and discectomy (PPECFD) has been widely used to treat cervical radiculopathy because of its advantages. However, combination of these 2 procedures in the treatment of cervical radiculopathy with diagnostic uncertainty has not been reported. OBJECTIVES: To examine the clinical outcomes of PPECFD assisted with SNRB in patients who had cervical radiculopathy with diagnostic uncertainty. STUDY DESIGN: A retrospective design was used. SETTING: This study was conducted in a university-affiliated tertiary hospital in Shanghai, China. METHODS: Thirty consecutive patients with cervical radicular pain who had diagnostic uncertainty were included (January 2018 to January 2019). Diagnostic SNRB was performed to identify the responsible nerve root(s). PPECFD was selected as the treatment when the SNRB result was positive. Clinical outcomes were assessed by the Visual Analog Scale (VAS), Neck Disability Index (NDI), and modified Macnab criteria. Pre- and post-operative radiologic and clinical parameters were evaluated. Other information was retrieved from the electronic records. RESULTS: All patients had successful SNRB procedures. Four were excluded from the analysis because of the negative results of the SNRB. Among the remaining 26 patients who underwent the subsequent PPECFD surgery, the mean follow-up was 14 months. Compared with preoperative values, the mean VAS scores for radicular arm pain and neck pain, as well as the NDI score, improved significantly. According to the Macnab criteria, 22 patients (84.6%) had excellent or good results. No major peri- and postoperative complications were observed. LIMITATIONS: This study used a retrospective design with relatively small sample size and medium follow-up duration. CONCLUSIONS: Diagnostic SNRB may be a helpful tool to identify the origin of cervical radicular pain for patients with diagnostic uncertainty. With the guidance of SNRB, PPECFD is likely to be an effective and safe option for the treatment of cervical radiculopathy with diagnostic uncertainty.


Assuntos
Foraminotomia , Radiculopatia , Vértebras Cervicais/cirurgia , China , Discotomia , Humanos , Radiculopatia/diagnóstico , Radiculopatia/cirurgia , Estudos Retrospectivos , Resultado do Tratamento , Incerteza
10.
ACS Appl Mater Interfaces ; 13(28): 32673-32689, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34227792

RESUMO

Injectable hydrogels have received much attention because of the advantages of simulation of the natural extracellular matrix, microinvasive implantation, and filling and repairing of complex shape defects. Yet, for bone repair, the current injectable hydrogels have shown significant limitations such as the lack of tissue adhesion, deficiency of self-healing ability, and absence of osteogenic activity. Herein, a strategy to construct mussel-inspired bisphosphonated injectable nanocomposite hydrogels with adhesive, self-healing, and osteogenic properties is developed. The nano-hydroxyapatite/poly(l-glutamic acid)-dextran (nHA/PLGA-Dex) dually cross-linked (DC) injectable hydrogels are fabricated via Schiff base cross-linking and noncovalent nHA-BP chelation. The chelation between bisphosphonate ligands (alendronate sodium, BP) and nHA favors the uniform dispersion of the latter. Moreover, multiple adhesion ligands based on catechol motifs, BP, and aldehyde groups endow the hydrogels with good tissue adhesion. The hydrogels possess excellent biocompatibility and the introduction of BP and nHA both can effectively promote viability, proliferation, migration, and osteogenesis differentiation of MC3T3-E1 cells. The incorporation of BP groups and HA nanoparticles could also facilitate the angiogenic property of endothelial cells. The nHA/PLGA-Dex DC hydrogels exhibited considerable biocompatibility despite the presence of a certain degree of inflammatory response in the early stage. The successful healing of a rat cranial defect further proves the bone regeneration ability of nHA/PLGA-Dex DC injectable hydrogels. The developed tissue adhesive osteogenic injectable nHA/PLGA-Dex hydrogels show significant potential for bone regeneration application.


Assuntos
Materiais Biomiméticos/química , Regeneração Óssea/efeitos dos fármacos , Hidrogéis/química , Nanocompostos/química , Osteogênese/efeitos dos fármacos , Tecidos Suporte/química , Adesivos/síntese química , Adesivos/química , Adesivos/toxicidade , Alendronato/análogos & derivados , Alendronato/toxicidade , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/toxicidade , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/toxicidade , Osso e Ossos/efeitos dos fármacos , Linhagem Celular , Fenômenos Fisiológicos Celulares/efeitos dos fármacos , Dextranos/síntese química , Dextranos/química , Dextranos/toxicidade , Durapatita/síntese química , Durapatita/química , Durapatita/toxicidade , Feminino , Hidrogéis/síntese química , Hidrogéis/toxicidade , Masculino , Camundongos , Nanocompostos/toxicidade , Ácido Poliglutâmico/síntese química , Ácido Poliglutâmico/química , Ácido Poliglutâmico/toxicidade , Ratos Sprague-Dawley , Suínos , Engenharia Tecidual/métodos
11.
Int J Comput Assist Radiol Surg ; 16(10): 1829-1839, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34327630

RESUMO

PURPOSE: To assess the clinical and radiological outcomes of using endoscopic foraminoplasty and decompression assisted with a preoperative planning software in the treatment of lumbar foraminal stenosis. METHODS: This retrospective study included 43 patients with lumbar foraminal stenosis (Jan 2018 and June 2019). These patients were divided into two groups. Patients in the conventional group (group A) underwent endoscopic lumbar foraminoplasty and decompression. Patients in the experimental group (group B) underwent the same surgery assisted with a preoperative software. The total operation time, puncture-channel establishment time, and the number of intraoperative fluoroscopic images taken were recorded. The Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) were administered preoperatively and postoperatively (at 1-month, 3-month, and 12-month follow-up). The modified MacNab criteria were used to assess the global outcome at 12-month follow-up. RESULTS: Patients in group B had shorter operation time, puncture-channel establishment time, and less number of intraoperative fluoroscopic images taken, as compared with group A. The VAS and ODI scores were significantly lower than pre-operation for both groups at all follow-ups. No significant difference was observed between these two groups. Based on the modified MacNab criteria, the excellent-to-good rate was 86.4% in group A and 90.5% in group B, respectively. After the operation, no patients had residual osteophytes in group B, while two patients still had residual osteophytes and foraminal stenosis in group A. CONCLUSION: For endoscopic surgery treating lumbar foraminal stenosis, using preoperative planning software could reduce the puncture-channel establishment time, operation time, and the number of intraoperative fluoroscopic images taken without affecting the clinical outcomes.


Assuntos
Estenose Espinal , Constrição Patológica , Descompressão Cirúrgica , Endoscopia , Humanos , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Estudos Retrospectivos , Software , Punção Espinal , Estenose Espinal/diagnóstico por imagem , Estenose Espinal/cirurgia , Resultado do Tratamento
12.
J Bone Miner Metab ; 39(6): 914-924, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34250565

RESUMO

Osteoporosis is a common form of metabolic bone disease that is costly to treat and is primarily diagnosed on the basis of bone mineral density. As the influences of genetic lesions and environmental factors are increasingly studied in the pathological development of osteoporosis, regulated epigenetics are emerging as the important pathogenesis mechanisms in osteoporosis. Recently, osteoporosis genome-wide association studies and multi-omics technologies have revealed that susceptibility loci and the misregulation of epigenetic modifiers are key factors in osteoporosis. Over the past decade, extensive studies have demonstrated epigenetic mechanisms, such as DNA methylation, histone/chromatin modifications, and non-coding RNAs, as potential contributing factors in osteoporosis that affect disease initiation and progression. Herein, we review recent advances in epigenetics in osteoporosis, with a focus on exploring the underlying mechanisms and potential diagnostic/prognostic biomarker applications for osteoporosis.


Assuntos
Estudo de Associação Genômica Ampla , Osteoporose , Metilação de DNA/genética , Epigênese Genética/genética , Humanos , Osteoporose/genética
13.
Biomol NMR Assign ; 15(2): 409-413, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34169459

RESUMO

Human protein disulfide isomerase (PDI), a protein containing 4 domains a, b, b', a', disordered x linker and C-terminus, plays critical roles in disulfide bond reactions and proper protein folding in the endoplasmic reticulum. The bb' domain contributes to client binding, the a, a' domain catalyse the rearrangement of the disulfide bonds. The x linker and a' domain were the main dynamics region for full-length PDI and the b'xa' construct has the minimum functional domain within full-length PDI. Herein, we report a new preparation strategy with 1, 6-hexandiol and backbone NMR chemical shift assignments for the monomer b'xa' domain.

14.
Biomol NMR Assign ; 15(2): 403-407, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34170495

RESUMO

Japanese encephalitis virus (JEV) is a flavivirus in the same family as West Nile virus (WNV), dengue virus (DENV) and yellow fever virus (YFV), which are transmitted by mosquitoes. About 68 thousand people are infected with JEV every year. In many Asian countries, JEV is the main cause of viral encephalitis. There are no specific antiviral drugs for Japanese encephalitis. Capsid protein C is the core protein of virus particles. Many studies have revealed that capsid protein C plays an important role in the life cycle of flaviviruses. Although the structure of JEV capsid protein (JEVC) has been determined by X-ray crystallography, the mechanism of how it assembles into an inner core to encapsulate the virus genome remains elusive. What's more, the disordered N-terminal region that is reported to affect its assembly is absent in the crystal structure. NMR spectroscopy has distinct advantages over other technologies in the characterization of conformational dynamics. Here we report the backbone 1H, 13C and 15N chemical shift assignments of JEVC by heteronuclear multidimensional spectroscopy and predict its secondary structure in solution using TALOS+.

15.
J Exp Bot ; 72(18): 6510-6523, 2021 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-34165534

RESUMO

Phosphate (Pi)-starved crops utilize phospholipids as a source for internal Pi supply by replacing non-phosphorus glycolipids. In rice, sulfoquinovosyl diacylglycerol synthase 1 (OsSQD1) functions as a key enzyme in the first step to catalyze sulfoquinovosyldiacylglycerol (SQDG) formation. Here we study differential expression of OsSQD1 in response to Pi, nitrogen, potassium, and iron-deficiencies in rice. Electrophoretic mobility shift assay suggested that OsSQD1 is regulated by OsPHR2 (Phosphate Starvation Response2), a MYB (v-myb avian myeloblastosis viral oncogene homolog) domain-containing transcription factor. The concentrations of different lipid species in ossqd1 knockout mutant demonstrated that OsSQD1 silencing increased the phospholipid content and altered fatty acid composition under Pi-deficiency. Moreover, OsSQD1 silencing reduces glycolipid accumulation under Pi-deficiency, and triggered the saturation of fatty acids in phospholipids and glycolipids treated with different Pi regimes. Relative amounts of transcripts related to phospholipid degradation and glycolipid synthesis were assessed to explore the mechanism by which OsSQD1 exerts an effect on lipid homeostasis under P-deficiency. Furthermore, OsSQD1 silencing inhibited photosynthesis, especially under Pi-deficient conditions, by down-regulating glycolipids in rice shoots. Taken together, our study reveals that OsSQD1 plays a key role in lipid homeostasis, especially glycolipid accumulation under Pi-deficiency, which results in the inhibition of photosynthesis.


Assuntos
Oryza , Diglicerídeos , Glicolipídeos , Oryza/genética , Fosfatos , Fotossíntese
16.
Bioact Mater ; 6(12): 4717-4728, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34136722

RESUMO

It is very challenging to visualize implantable medical devices made of biodegradable polymers in deep tissues. Herein, we designed a novel macromolecular contrast agent with ultrahigh radiopacity (iodinate content > 50%) via polymerizing an iodinated trimethylene carbonate monomer into the two ends of poly(ethylene glycol) (PEG). A set of thermosensitive and biodegradable polyester-PEG-polyester triblock copolymers with varied polyester compositions synthesized by us, which were soluble in water at room temperature and could spontaneously form hydrogels at body temperature, were selected as the demonstration materials. The addition of macromolecular contrast agent did not obviously compromise the injectability and thermogelation properties of polymeric hydrogels, but conferred them with excellent X-ray opacity, enabling visualization of the hydrogels at clinically relevant depths through X-ray fluoroscopy or Micro-CT. In a mouse model, the 3D morphology of the radiopaque hydrogels after injection into different target sites was visible using Micro-CT imaging, and their injection volume could be accurately obtained. Furthermore, the subcutaneous degradation process of a radiopaque hydrogel could be non-invasively monitored in a real-time and quantitative manner. In particular, the corrected degradation curve based on Micro-CT imaging well matched with the degradation profile of virgin polymer hydrogel determined by the gravimetric method. These findings indicate that the macromolecular contrast agent has good universality for the construction of various radiopaque polymer hydrogels, and can nondestructively trace and quantify their degradation in vivo. Meanwhile, the present methodology developed by us affords a platform technology for deep tissue imaging of polymeric materials.

17.
BMC Plant Biol ; 21(1): 211, 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33975546

RESUMO

BACKGROUND: Nitrogen (N) is an important nutrient for plant growth, development, and agricultural production. Nitrogen stress could induce epigenetic changes in plants. In our research, overexpression of the OsNAR2.1 line was used as a testing target in rice plants with high nitrogen-use efficiency to study the changes of rice methylation and growth in respond of the endogenous and external nitrogen stress. RESULTS: Our results showed that external N deficiency could decrease seed N content and plant growth of the overexpression line. During the filial growth, we found that the low parent seed nitrogen (LPSN) in the overexpression line could lead to a decrease in the filial seed nitrogen content, total plant nitrogen content, yield, and OsNAR2.1 expression (28, 35, 23, and 55%, respectively) compared with high parent seed nitrogen (HPSN) in high nitrogen external supply. However, such decreases were not observed in wild type. Furthermore, methylation sequencing results showed that LPSN caused massive gene methylation changes, which enriched in over 20 GO pathways in the filial overexpression line, and the expression of OsNAR2.1 in LPSN filial overexpression plants was significantly reduced compared to HPSN filial plants in high external N, which was not shown in wild type. CONCLUSIONS: We suggest that the parent seed nitrogen content decreased induced DNA methylation changes at the epigenetic level and significantly decreased the expression of OsNAR2.1, resulting in a heritable phenotype of N deficiency over two generations of the overexpression line.


Assuntos
Metilação de DNA , Nitrogênio/análise , Oryza/crescimento & desenvolvimento , Oryza/genética , Oryza/metabolismo , Sementes/química , Sementes/metabolismo , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , DNA de Plantas , Regulação da Expressão Gênica de Plantas , Variação Genética , Genótipo , Plantas Geneticamente Modificadas
18.
Front Pharmacol ; 12: 671563, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34054544

RESUMO

Lack of vascularization is directly associated with refractory wound healing in diabetes mellitus (DM). Enrichment of endothelial precursor cells (EPCs) is a promising but challenging approach for the treatment of diabetic wounds. Herein, we investigate the action of nicotinamide riboside (NR) on EPC function for improved healing of diabetic wounds. Db/db mice that were treated with NR-supplemented food (400 mg/kg/d) for 12 weeks exhibited higher wound healing rates and angiogenesis than untreated db/db mice. In agreement with this phenotype, NR supplementation significantly increased the number of blood EPCs and bone marrow (BM)-derived EPCs of db/db mice, as well as the tube formation and adhesion functions of BM-EPCs. Furthermore, NR-supplemented BM-EPCs showed higher expression of sirtuin 1 (Sirt1), phosphorylated adenosine monophosphate-activated protein kinase (p-AMPK), and lower expression of acetylated peroxisome proliferator-activated receptor γ coactivator (PGC-1α) than BM-EPCs isolated from untreated db/db mice. Knockdown of Sirt1 in BM-EPCs significantly abolished the tube formation and adhesion function of NR as well as the expression of p-AMPK and deacetylated PGC-1a. Inhibition of AMPK abolished the NR-regulated EPC function but had no effect on Sirt1 expression, demonstrating that NR enhances EPC function through the Sirt1-AMPK pathway. Overall, this study demonstrates that the oral uptake of NR enhances the EPC function to promote diabetic wound healing, indicating that NR supplementation might be a promising strategy to prevent the progression of diabetic complications.

19.
Breed Sci ; 71(1): 62-75, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33762877

RESUMO

As sessile organisms, plants rely on their roots for anchorage and uptake of water and nutrients. Plant root is an organ showing extensive morphological and metabolic plasticity in response to diverse environmental stimuli including nitrogen (N) and phosphorus (P) nutrition/stresses. N and P are two essential macronutrients serving as not only cell structural components but also local and systemic signals triggering root acclimatory responses. Here, we mainly focused on the current advances on root responses to N and P nutrition/stresses regarding transporters as well as long-distance mobile proteins and peptides, which largely represent local and systemic regulators, respectively. Moreover, we exemplified some of the potential pitfalls in experimental design, which has been routinely adopted for decades. These commonly accepted methods may help researchers gain fundamental mechanistic insights into plant intrinsic responses, yet the output might lack strong relevance to the real situation in the context of natural and agricultural ecosystems. On this basis, we further discuss the established-and yet to be validated-improvements in experimental design, aiming at interpreting the data obtained under laboratory conditions in a more practical view.

20.
Nat Commun ; 12(1): 735, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33531490

RESUMO

Nitrogen (N) and carbon (C) are essential elements for plant growth and crop yield. Thus, improved N and C utilisation contributes to agricultural productivity and reduces the need for fertilisation. In the present study, we find that overexpression of a single rice gene, Oryza sativa plasma membrane (PM) H+-ATPase 1 (OSA1), facilitates ammonium absorption and assimilation in roots and enhanced light-induced stomatal opening with higher photosynthesis rate in leaves. As a result, OSA1 overexpression in rice plants causes a 33% increase in grain yield and a 46% increase in N use efficiency overall. As PM H+-ATPase is highly conserved in plants, these findings indicate that the manipulation of PM H+-ATPase could cooperatively improve N and C utilisation, potentially providing a vital tool for food security and sustainable agriculture.


Assuntos
Membrana Celular/metabolismo , Oryza/enzimologia , Oryza/metabolismo , Proteínas de Plantas/metabolismo , ATPases Translocadoras de Prótons/metabolismo , Compostos de Amônio/metabolismo , Transporte Biológico , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Oryza/fisiologia , Fotossíntese/genética , Fotossíntese/fisiologia , Folhas de Planta/enzimologia , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Raízes de Plantas/enzimologia , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia
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