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1.
Food Chem X ; 21: 101061, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38187941

RESUMO

This study investigated the effects of ultra-high pressure (UHP) at different levels on the physicochemical properties, gelling properties, and in vitro digestion characteristics of myofibrillar protein (MP) in Tai Lake whitebait. The α-helix gradually unfolded and transformed into ß-sheet as the pressure increased from 0 to 400 MPa. In addition, the elastic modulus (G') and viscous modulus (G'') of the 400 MPa-treated MP samples increased by 4.8 and 3.8 times, respectively, compared with the control group. The gel properties of the MP also increased significantly after UHP treatment, e.g., the gel strength increased by a 4.8-fold when the pressure reached 400 Mpa, compared with the control group. The results of in vitro simulated digestion showed that the 400 MPa-treated MP gel samples showed a 1.8-fold increase in digestibility and a 69.6 % decrease in digestible particle size compared with the control group.

2.
Insect Sci ; 2024 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-38214184

RESUMO

The foregut, located at the front of the digestive tract, serves a vital role in insects by storing and grinding food into small particles. The innermost layer of the foregut known as the chitinous intima, comes into direct contact with the food and acts as a protective barrier against abrasive particles. Knickkopf (Knk) is required for chitin organization in the chitinous exoskeleton, tracheae and wings. Despite its significance, little is known about the biological function of Knk in the foregut. In this study, we found that LmKnk was stably expressed in the foregut, and highly expressed before molting in Locusta migratoria. To ascertain the biological function of LmKnk in the foregut, we synthesized specific double-stranded LmKnk (dsLmKnk) and injected it into locusts. Our findings showed a significant decrease in the foregut size, along with reduced food intake and accumulation of residues in the foregut after dsLmKnk injection. Morphological observations revealed that newly formed intima became thinner and lacked chitin lamella. Furthermore, fluorescence immunohistochemistry revealed that LmKnk was located in the apical region of new intima and epithelial cells. Taken together, this study provides insights into the biological function of LmKnk in the foregut, and identifies the potential target gene for exploring biological pest management strategies.

3.
Org Lett ; 25(48): 8683-8687, 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38014880

RESUMO

Hydrothiocarbonylation of olefins using carbon monoxide and thiols is a powerful method to synthesize thioesters from simple building blocks. Owing to the intrinsic challenges of catalyst poisoning, transition-metal-catalyzed asymmetric thiocarbonylation, particularly when utilizing earth abundant metals, remains rare in the literature. Herein, we report a nickel-catalyzed enantioselective hydrothiocarbonylation of cyclopropenes for the synthesis of a diverse collection of functionalized thioesters in good to excellent yields with high stereoselectivity. This new method employs an inexpensive, air-stable nickel(II) precursor, which provides enhanced catalyst fidelity against CO poisoning compared to nickel(0) catalysts.

4.
Org Lett ; 25(40): 7422-7427, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37781988

RESUMO

Novel regioselective hydrodeoxygenation of α-diketones with phosphites as the deoxygenation reagent was realized via visible-light photoredox catalysis. Broad substrate scope and high functional group compatibility were obtained. Unsymmetric α-diketones were selectively reduced at the carbonyls of higher electrophilicity. This unique regioselectivity compared with available methods makes it a practical complementary approach for the monohydrodeoxygenation of α-diketones.

5.
Org Lett ; 25(27): 5128-5133, 2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37409772

RESUMO

We herein develop a highly diastereoselective synthesis of cyano-substituted cyclopropanes via palladium-catalyzed direct cyanoesterification of cyclopropenes, which features mild reaction conditions, good functional group compatibility, and simple operation. This transformation represents a stepwise, highly atom economic, and scalable protocol for obtaining synthetically useful cyclopropanecarbonitriles.


Assuntos
Paládio , Catálise , Estereoisomerismo
6.
J Control Release ; 356: 595-609, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36924896

RESUMO

How to achieve efficient drug accumulation in the tumor with low vascular density is a great challenge but the key to push the limit of anti-vascular therapeutic efficacy. Herein, we report a charge-reversible nanoparticles of gambogenic acid (CRNP-GNA) that would induce the positive feedback loop between increased tumor vascular permeability and improved drug accumulation. This positive feedback loop would remarkably improve tumor vascular permeability for efficient drug accumulation through few residue vessels. As compared to its charge-irreversible analogue in the latter injections, the accumulation in tumor and vascular permeability and retention indexes (VPRI) in CRNP-GNA group respectively boosted from nearly equal to 8.32 and 60 times, while its tumorous microvessel density decreased from nearly equal to only 7%. The self-augmented accumulation consequently amplified the antitumor efficacy via multiple pathways of anti-angiogenesis, vascular disruption and pro-apoptosis, where 5 out of 6 tumors in animal models were completely cured by CRNP-GNA. This work confirms that the underlying positive feedback loop for anti-vascular therapy could be induced by charge-reversible drug delivery nanosystem to achieve efficient and self-augmented drug accumulation even in the tumor with few vessels. It provides a novel strategy to conquer the dilemma between anti-vascular efficacy and drug accumulation.


Assuntos
Nanopartículas , Neoplasias , Animais , Retroalimentação , Neoplasias/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Linhagem Celular Tumoral
7.
J Mater Chem B ; 11(15): 3364-3372, 2023 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-36883988

RESUMO

The membrane-disruptive strategy, which involves host defense peptides and their mimetics, is a revolutionary cancer treatment based on broad-spectrum anticancer activities. However, clinical application is limited by low selectivity towards tumors. In this context, we have established a highly selective anticancer polymer, i.e. poly(ethylene glycol)-poly(2-azepane ethyl methacrylate) (PEG-PAEMA), that can mediate the membrane-disruptive activity via a subtle pH change between physiological pH and tumor acidity for selective cancer treatment. Specifically, the resulting PEG-PAEMA can assemble into neutral nanoparticles and silence the membrane-disruptive activity at physiological pH and disassemble into cationic free-chains or smaller nanoparticles with potent membrane-disruptive activity after the protonation of the PAEMA block due to tumor acidity, resulting in high selectivity towards tumors. Dramatically, PEG-PAEMA exhibited a >200-fold amplification in hemolysis and <5% in IC50 against Hepa1-6, SKOV3 and CT-26 cells at pH 6.7 as compared to those at pH 7.4, thanks to the selective membrane-disruptive mechanism. Moreover, mid- and high-dose PEG-PAEMA demonstrated higher anticancer efficacy than an optimal clinical prescription (bevacizumab plus PD-1) and, significantly, had few side effects on major organs in the tumor-bearing mice model, agreeing with the highly selective membrane-disruptive activity in vivo. Collectively, this work showcases the latent anticancer pharmacological activity of the PAEMA block, and also brings new hope for selective cancer therapy.


Assuntos
Neoplasias , Polietilenoglicóis , Animais , Camundongos , Concentração de Íons de Hidrogênio , Polietilenoglicóis/uso terapêutico , Neoplasias/tratamento farmacológico , Interações Hidrofóbicas e Hidrofílicas
8.
IEEE Trans Cybern ; 53(1): 289-302, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34347617

RESUMO

We consider mechanical systems with uncertainty. The uncertainty may be time varying. The bound of the uncertainty is described by its fuzzy characteristics. To design a feasible control, we start with a robust phase, which renders a control scheme that guarantees the system performance regardless of the actual value of the uncertainty. This robust phase is then followed by an optimal phase. There are design parameters in the control, which can be fine-tuned. We proposed multiple performance objectives. The goal of the choice of the control design parameters is to minimize the performance objectives. However, since these objectives are nonconciliating (meaning one's minimum is not the other one's minimum), we invoke the Stackelberg strategy for the optimal parameters. The game strategy mimics two players: one is the leader and one is the follower. Through the interplay between the two players, we show how to select the design parameters. The design procedure in both robust and optimal phases is demonstrated by a coupled inverted pendulum system.

9.
Artigo em Inglês | MEDLINE | ID: mdl-36554909

RESUMO

Autism spectrum disorder (ASD) seriously affects children's health. In our previous study, we isolated and identified a bacterium (Lactobacillus plantarum strain 6-1) that is resistant to propionic acid (PA), which has been reported to play a significant role in the formation of ASD. In order to elucidate the mechanism of the resistance to PA, this study investigated the change in the metabolic and proteomic profile of L. plantarum strain 6-1 in the presence and absence of PA. The results show that 967 and 1078 proteins were specifically identified in the absence and the presence of PA, respectively, while 616 proteins were found under both conditions. Gene ontology enrichment analysis of 130 differentially expressed proteins accumulated in the presence and absence of PA indicated that most of the proteins belong to biological processes, cellular components, and molecular functions. Pathway enrichment analysis showed a great reduction in the metabolic pathway-related proteins when this resistant bacterium was exposed to PA compared to the control. Furthermore, there was an obvious difference in protein-protein interaction networks in the presence and the absence of propionic acid. In addition, there was a change in the metabolic profile of L. plantarum strain 6-1 when this bacterium was exposed to PA compared to the control, while six peaks at 696.46, 1543.022, 1905.241, 2004.277, 2037.374, and 2069.348 m/z disappeared. Overall, the results could help us to understand the mechanism of the resistance of gut bacteria to PA, which will provide a new insight for us to use PA-resistant bacteria to prevent the development of ASD in children.


Assuntos
Transtorno do Espectro Autista , Lactobacillus plantarum , Criança , Humanos , Lactobacillus plantarum/genética , Lactobacillus plantarum/metabolismo , Proteômica/métodos , Propionatos/farmacologia
10.
Angew Chem Int Ed Engl ; 61(36): e202200733, 2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-35836371

RESUMO

The asymmetric Reppe carbonylation reactions provide a straightforward access to α-chiral carbonyl compounds. The reported paradigms predominantly adopted precious palladium as the catalyst. Here we report a nickel-catalyzed asymmetric carbonylation of cyclopropenes with phenyl formate and CO/ROH, respectively. This asymmetrical synthetic protocol features high atom economy, good functional group tolerance, which rapidly constructs polysubstituted cyclopropanecarboxylic derivatives with excellent diastereo- and enantioselectivity. The synthetic utility is demonstrated by facile conversion of the chiral products into bioactive molecules such as (-)-Tranylcypromine and (-)-Lemborexant.

11.
J Diabetes Res ; 2022: 3780156, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35712028

RESUMO

Methods: Male C57BL/6J mice were randomly divided into six different experimental groups (8 animals/group): (1) normal group (NOR), (2) normal control group (NC), (3) normal + exercise group (NE), (4) IGT group (IGT), (5) IGT control group (IC), and (6) IGT+ exercise group (IE).The exercise group received aerobic exercise for 8 weeks. After the intervention, a blood glucose meter was used to detect the level of glucose tolerance in the mouse's abdominal cavity; a biochemical kit was used to detect serum lipid metabolism indicators, malondialdehyde, and superoxide dismutase levels; the ELISA method was used to detect serum insulin and mouse gastrocnemius homogenate LDH, PDH, SDH, and CCO levels. Western blot method was used to detect the protein expression levels of NOX4, PGC-1α, and Mfn2 in the gastrocnemius muscle of mice. Results: (1) Mice with high-fat diet for 30 weeks showed impaired glucose tolerance, insulin resistance, and lipid metabolism disorders. The level of LDH, PDH, SDH, and CCO in the gastrocnemius homogenate of mice was reduced. The expressions of NOX4 protein were significantly upregulated, while the expressions of PGC-1α and Mfn2 proteins were significantly downregulated. (2) 8-week aerobic exercise improved the disorders of glucose and lipid metabolism in IGT mice and increased homogenized LDH, PDH, SDH, and CCO levels, and the expressions of NOX4, PGC-1α, and Mfn2 proteins in the gastrocnemius muscle of mice were reversed. It is speculated that aerobic exercise can accelerate energy metabolism. Conclusion: (1) C57BL/6 mice were fed high fat for 30 weeks and successfully constructed a mouse model of reduced diabetes; the mice with reduced diabetes have impaired glucose tolerance, insulin resistance, and lipid metabolism disorders; (2) 8 weeks of aerobic exercise improve glucose tolerance, reduce glucose tolerance in mice, reduce insulin resistance, improve lipid metabolism disorders, and reduce oxidative stress; (3) 8-week aerobic exercise reduces skeletal muscle NOX4 expression and increases glucose tolerance; reduces the expression of LDH, PDH, SDH, and CCO in mouse skeletal muscle; increases the expression level of mitochondrial fusion protein 2 and PGC-1α; improves glucose tolerance; reduces energy metabolism of mouse skeletal muscle; reduces oxidative stress; and reduces insulin resistance. It is speculated that aerobic exercise can accelerate energy metabolism. This process may involve two aspects: firstly, increase the expression level of oxidative metabolism enzymes and promote the tricarboxylic acid cycle; secondly, increase the expression of Mfn2 and accelerate mitochondria fission or fusion to regulate energy metabolism, thereby reducing oxidative stress and insulin resistance.


Assuntos
Intolerância à Glucose , Resistência à Insulina , Animais , Glucose/farmacologia , Intolerância à Glucose/metabolismo , Resistência à Insulina/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Mitocôndrias Musculares/metabolismo , Músculo Esquelético/metabolismo , Estresse Oxidativo
12.
J Colloid Interface Sci ; 622: 261-271, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35512590

RESUMO

Core-shell structure has been receiving extensive attention to enhance the electromagnetic wave (EMW) absorption performance due to its unique interface effect. In this paper, a micro-flower like ZnCo@C@1T-2H-MoS2 was prepared through MOF self-template method. The introduction 1T-2H-MoS2 shell helps optimize impedance matching of the CoZn@C particles to improve the EMW absorption ability. The minimal reflection loss (RLmin) value of ZnCo@C@1T-2H-MoS2 is -35.83 dB with a thickness of 5.0 mm at 5.83 GHz and the effective absorption (RL < -10 dB) bandwidth up to 4.56 GHz at 2.0 mm thickness. Meanwhile, the overall effective absorption bandwidth (OEAB) can reach up to 13.44 GHz from 4.56 to 18.0 GHz. Moreover, ultrafast photothermal performances are also achieved, which can guarantee the normal functioning of ZnCo@C@1T-2H-MoS2 materials in cold conditions. The excellent EMW absorption and photothermal performance are attributed to the unique structure designed with the core of magnetic ZnCo@C rhombic dodecahedral and the shell of dielectric micro-flower like 1T-2H-MoS2 optimize impedance matching.


Assuntos
Radiação Eletromagnética , Molibdênio , Impedância Elétrica
13.
IEEE Trans Cybern ; 52(7): 7151-7163, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33284771

RESUMO

There is uncertainty in the system, and we consider that uncertainty is (possibly fast) time varying, but with definite bound. Fuzzy set theory is used to describe the inexact boundary and then the problem of robust control of uncertain dynamical systems is studied. Based on two adjustable design parameters, a robust control method for general mechanical systems is proposed. The control is deterministic, not the conventional IF-THEN rule based. By using the Lyapunov minimax approach, it is proved that the proposed control can guarantee system performance to be uniformly bounded and uniformly ultimately bounded. In order to find the optimal solution in the prescribed range, a two-player cooperative game is used. To reduce costs while ensuring control performance, two performance indices are developed, each of which is controlled by an adjustable parameter (i.e., player). Both necessary and sufficient conditions for Pareto-optimality are established. Using these conditions, the Pareto-optimal solution can be obtained. The effectiveness of the control design is demonstrated by the simulation of the two-body pendulum.

14.
Materials (Basel) ; 14(19)2021 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-34639886

RESUMO

Autism spectrum disorder (ASD) seriously affects children's health, while the gut microbiome has been widely hypothesized to be involved in the regulation of ASD behavior. This study investigated and compared the number, diversity, and population structure of gut microbiota between healthy and ASD children and their susceptibility to zinc oxide nanoparticles (ZnONPs) based on the measurement of live cell number, living/dead bacterial staining test, flow cytometry observation and bacterial community analysis using 16S rRNA gene amplicon sequencing. The result of this present study revealed that ASD children not only significantly reduced the live cell number and the community diversity of gut bacteria, but also changed the gut bacterial community composition compared to the healthy children. In addition, this result revealed that ZnONPs significantly reduced the number of live bacterial cells in the gut of healthy children, but not in that of ASD children. In contrast, ZnONPs generally increased the gut bacterial community diversity in both ASD and healthy children, while a greater increase was found in ASD children than that of healthy children. Furthermore, this study successfully isolated and identified some representative nanoparticle-resistant bacteria based on the color, shape, and edge of colony as well as the 16S rDNA sequence analysis. The community of nanoparticle-resistant bacteria differed in between healthy and ASD children. Indeed, the representative strains 6-1, 6-2, 6-3 and 6-4 from healthy children were identified as Bacillus anthracis, Escherichia coli, Bacillus cereus and Escherichia coli with sequence similarity of 97.86%, 99.86%, 99.03% and 99.65%, respectively, while the representative strains 8-1, 8-2 and 8-3 from ASD children were identified as Bacillus cereus, with sequence similarities of 99.58%, 99.72% and 99.72%, respectively. Overall, this study demonstrated that ZnONPs caused a change in number, diversity, and species composition of gut bacteria, but differed in healthy and ASD children.

15.
Energy Build ; 251: 111346, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34566246

RESUMO

Although COVID-19 has significantly changed the higher educational sector, there are few studies revealing how this pandemic has changed the energy use of higher education buildings. This study was conducted not only to disclose the energy use change under COVID-19 but also to identify the corresponding facilities management strategies for future learning and teaching delivery modes under virtual campuses. This study collected the energy use data of 122 buildings across five campuses in Griffith University, located in Southeast Queensland, Australia, during the COVID-19 academic year (February 17, 2020, to February 21, 2021) and during a typical normal academic year (February 18, 2019, to February 16, 2020) by PI Vision Platform, and compared the data using the t-test and multiple linear regression. The results indicated that learning and administration activities became off campus during the pandemic, while research activities remained on campus. During the COVID-19 academic year, an amount of 9,646,933 kWh energy or around 24.88 kWh/m2 of energy use intensity was saved, which accounted for 16% of the total energy use per academic year. Specifically, the shutting down of air conditioning in academic buildings, administration buildings, retail buildings and teaching buildings during COVID-19 saved 4,566 kWh (1.13 kWh/m2), 966 kWh (0.8 kWh/m2), 1,472 kWh (1.4 kWh/m2) and 860 kWh (1.3 kWh/m2) of electricity use per week, respectively, which accounted for 51.5%, 44.3%, 48.3% and 57.1% of total energy use per week during this period, respectively. Based on this analysis and the changing educational environment, this study also speculated on the energy implications of future teaching and learning practices, which provided guidance to the facilities management under virtual campuses.

16.
Front Microbiol ; 12: 700707, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34421854

RESUMO

Attention-deficit hyperactivity disorder (ADHD) seriously affects children's health, and the gut microbiome has been widely hypothesized to play a role in the regulation of ADHD behavior. The present study aims to the biosynthesize of zinc oxide nanoparticles (ZnONPs) by using Acinetobacter johnsonii strain RTN1, followed by their characterization through state-of-the-art material characterization techniques, viz., UV-vis spectroscopy, Fourier transform infrared spectroscopy, and transmission and scanning electron microscopic analyses with energy dispersive spectrometry. Moreover, we investigated and compared the population composition of gut microbiota and their susceptibility to biogenic ZnONPs between healthy and ADHD children based on the traditional plate method and 16S rRNA amplicon sequence analysis. The antibacterial effect of ZnONPs against gut bacteria was also determined by measurement of live cell number, living/dead bacterial staining test, and flow cytometry observation. The present study revealed that the number of live gut bacteria in healthy children was more than 10-fold higher than that in ADHD children; however, the community structure of gut bacteria has changed, while greater diversity was found in gut bacteria from ADHD children. In addition, we found that the number of live gut bacteria in healthy and ADHD children was reduced by ZnONPs, which shows an increased and reduced effect in composition of gut bacteria from healthy and ADHD children, respectively. It was also noted that the main mechanism of ZnONPs may be to inhibit the growth of gut bacteria rather than to kill them, while the nanoparticle-resistant strains in healthy children is also different from that in ADHD children. Some representative bacteria, in particular nanoparticle-resistant bacteria, were successfully isolated and identified. Overall, this study revealed the potential correlation of ADHD with gut bacteria and provided a new possibility to prevent ADHD by the combination of nanoparticle and its resistant bacteria.

17.
J Org Chem ; 86(13): 8987-8996, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34115513

RESUMO

Palladium-catalyzed C-P bond formation reaction of ArBr/ArOTf using acylphosphines as differential phosphination reagents is reported. The acylphosphines show practicable reactivity with ArBr and ArOTf as the phosphination reagents, though they are inert to the air and moisture. The reaction affords trivalent phosphines directly in good yields with a broad substrate scope and functional group tolerance. This reaction discloses the acylphosphines' capability as new phosphorus sources for the direct synthesis of trivalent phosphines.

18.
Pestic Biochem Physiol ; 175: 104854, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33993972

RESUMO

Chitin deacetylases including CDA1 and CDA2, containing a chitin deacetylase domain and an LDL domain, have been reported to be essential for cuticle structure differentiation in different insect species. However, it is yet unexplored whether CDA1 and CDA2 activity is needed for the function of the cuticle as a barrier against pathogen and xenobiotics penetration. In this study, we studied the efficiency of fungal infection in the migratory locust Locusta migratoria in dependence of LmCDA1 and LmCDA2 function. Second instar nymphs injected with dsRNA against LmCDA1 and LmCDA2 transcripts were less resistant against the infection by the fungus Metarhizium anisopliae than control nymphs. At the same time, permeability to organophosphorus pesticides was increased in these nymphs. Interestingly, the CHC amounts at the cuticle surface were unaffected upon LmCDA1 and LmCDA2 reduction. These results suggest that the barrier function of the locust cuticle not only depends on surface CHCs, but also on an intact procuticle.


Assuntos
Locusta migratoria , Metarhizium , Animais , Proteínas de Insetos/genética , Locusta migratoria/genética , Metarhizium/genética , Ninfa , Filogenia
19.
Org Lett ; 23(3): 930-935, 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33481617

RESUMO

A regio-, chemo-, and enantioselective nickel-catalyzed hydrocyanation of 1,3-dienes is reported. The key to the success of this asymmetric transformation is the use of a specific multichiral diphosphite ligand. In addition to aryl-substituted 1,3-dienes, highly challenging aliphatic 1,3-diene substrates can also be preferentially converted to the corresponding 1,2-adducts in decent yields with the highest enantioselectivities to date.

20.
Insect Sci ; 28(5): 1314-1325, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33037856

RESUMO

Chitin deacetylases (CDAs, including CDA1 and CDA2) are considered key enzymes for body cuticle formation and tracheal morphogenesis in various insect species. However, their functions in the formation of the cuticular intima of the foregut and hindgut are unclear. Here, we investigated the roles of their respective genes LmCDA1 and LmCDA2 in this process, in the hemimetabolous insect Locusta migratoria. Transcripts of LmCDA1 and LmCDA2 were highly expressed both before and after molting in the foregut. In the hindgut, their expression was high only before molting. In both the foregut and hindgut, LmCDA1 protein was localized in the basal half of the chitin matrix (procuticle), whereas LmCDA2 was detected in the upper half of the procuticle. Knockdown of LmCDA1 by RNA interference (RNAi) in 5th-instar nymphs caused no visible defects of the hindgut cuticle. By contrast, the chitinous lamellae of the cuticular intima in the foregut of knockdown animals were less compact than in control animals. RNAi against LmCDA2 led to thickening of both the foregut and hindgut cuticles, with a greater number of thinner laminae than in the respective control cuticles. Taken together, our results show that LmCDA1 and LmCDA2 have distinct, but overlapping, functions in chitin organization in the foregut cuticle. However, in the hindgut, this process seems independent of LmCDA1 activity but requires LmCDA2 function. Thus, the CDAs reflect tissue-specific differences in cuticular organization and function, which need further detailed molecular and histological analyses for full comprehension.


Assuntos
Quitina , Trato Gastrointestinal/metabolismo , Proteínas de Insetos , Locusta migratoria , Exoesqueleto , Animais , Quitina/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Locusta migratoria/genética , Locusta migratoria/metabolismo , Muda , Ninfa/genética , Ninfa/metabolismo , Interferência de RNA
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