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1.
Int J Mol Sci ; 25(7)2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38612566

RESUMO

Rubisco large-subunit methyltransferase (LSMT), a SET-domain protein lysine methyltransferase, catalyzes the formation of trimethyl-lysine in the large subunit of Rubisco or in fructose-1,6-bisphosphate aldolases (FBAs). Rubisco and FBAs are both vital proteins involved in CO2 fixation in chloroplasts; however, the physiological effect of their trimethylation remains unknown. In Nannochloropsis oceanica, a homolog of LSMT (NoLSMT) is found. Phylogenetic analysis indicates that NoLSMT and other algae LSMTs are clustered in a basal position, suggesting that algal species are the origin of LSMT. As NoLSMT lacks the His-Ala/ProTrp triad, it is predicted to have FBAs as its substrate instead of Rubisco. The 18-20% reduced abundance of FBA methylation in NoLSMT-defective mutants further confirms this observation. Moreover, this gene (nolsmt) can be induced by low-CO2 conditions. Intriguingly, NoLSMT-knockout N. oceanica mutants exhibit a 9.7-13.8% increase in dry weight and enhanced growth, which is attributed to the alleviation of photoinhibition under high-light stress. This suggests that the elimination of FBA trimethylation facilitates carbon fixation under high-light stress conditions. These findings have implications in engineering carbon fixation to improve microalgae biomass production.


Assuntos
Aldeído Liases , Lisina , Ribulose-Bifosfato Carboxilase/genética , Biomassa , Dióxido de Carbono , Filogenia , Frutose-Bifosfato Aldolase , Histona-Lisina N-Metiltransferase , Cloroplastos/genética
2.
Immunogenetics ; 75(1): 39-51, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36114381

RESUMO

The involvement of small nucleolar RNA host gene 3 (SNHG3) in cancer regulation has been reported. This study attempted to deeply investigate the molecular regulatory mechanism of SNHG3 on malignant progression of hepatocellular carcinoma (HCC). According to TCGA analysis, high SNHG3 expression was a risk factor for poor prognosis of HCC patients. Therefore, we further detected the mRNA level of SNHG3 in HCC tissue and cells. It was found that SNHG3 was upregulated in HCC tissue and cells. Afterwards, CCK-8 and flow cytometry assays further proved that silencing SNHG3 inhibited HCC cell proliferation while inducing cell apoptosis and G0/G1 phase arrest. It was also attested in vivo experiments that silencing SNHG3 could reduce the volume and weight of tumors and downregulate the Ki-67 expression to suppress HCC tumor growth. Next, it was discovered that SNHG3 increased the binding of E2F1 and NEIL3 promoter region, thereby activating the transcription feature of NEIL3. Lastly, rescue assays indicated that NEIL3 participated in SNHG3-mediated HCC cell cycle, apoptosis and proliferation. All in all, this study revealed the specific regulatory mechanism of SNHG3 in HCC to enable SNHG3 a hopeful marker for HCC diagnosis and treatment.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Humanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Fator de Transcrição E2F1/genética , Fator de Transcrição E2F1/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Proliferação de Células/genética , RNA Mensageiro/genética , Regulação Neoplásica da Expressão Gênica , Linhagem Celular Tumoral , MicroRNAs/genética
3.
Plant Physiol ; 190(3): 1658-1672, 2022 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-36040196

RESUMO

Depending on their fatty acid (FA) chain length, triacylglycerols (TAGs) have distinct applications; thus, a feedstock with a genetically designed chain length is desirable to maximize process efficiency and product versatility. Here, ex vivo, in vitro, and in vivo profiling of the large set of type-2 diacylglycerol acyltransferases (NoDGAT2s) in the industrial oleaginous microalga Nannochloropsis oceanica revealed two endoplasmic reticulum-localized enzymes that can assemble medium-chain FAs (MCFAs) with 8-12 carbons into TAGs. Specifically, NoDGAT2D serves as a generalist that assembles C8-C18 FAs into TAG, whereas NoDGAT2H is a specialist that incorporates only MCFAs into TAG. Based on such specialization, stacking of NoDGAT2D with MCFA- or diacylglycerol-supplying enzymes or regulators, including rationally engineering Cuphea palustris acyl carrier protein thioesterase, Cocos nucifera lysophosphatidic acid acyltransferase, and Arabidopsis thaliana WRINKLED1, elevated the medium-chain triacylglycerol (MCT) share in total TAG 66-fold and MCT productivity 64.8-fold at the peak phase of oil production. Such functional specialization of NoDGAT2s in the chain length of substrates and products reveals a dimension of control in the cellular TAG profile, which can be exploited for producing designer oils in microalgae.


Assuntos
Ácidos Graxos , Estramenópilas , Ácidos Graxos/metabolismo , Diglicerídeos , Estramenópilas/genética , Estramenópilas/metabolismo , Diacilglicerol O-Aciltransferase/genética , Diacilglicerol O-Aciltransferase/metabolismo , Triglicerídeos/metabolismo
4.
Plant J ; 106(4): 1148-1162, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33719095

RESUMO

Industrial microalgae are promising photosynthetic cell factories, yet tools for large-scale targeted genome engineering are limited. Here for the model industrial oleaginous microalga Nannochloropsis oceanica, we established a method to precisely and serially delete large genome fragments of ~100 kb from its 30.01 Mb nuclear genome. We started by identifying the 'non-essential' chromosomal regions (i.e. low expression region or LER) based on minimal gene expression under N-replete and N-depleted conditions. The largest such LER (LER1) is ~98 kb in size, located near the telomere of the 502.09-kb-long Chromosome 30 (Chr 30). We deleted 81 kb and further distal and proximal deletions of up to 110 kb (21.9% of Chr 30) in LER1 by dual targeting the boundaries with the episome-based CRISPR/Cas9 system. The telomere-deletion mutants showed normal telomeres consisting of CCCTAA repeats, revealing telomere regeneration capability after losing the distal part of Chr 30. Interestingly, the deletions caused no significant alteration in growth, lipid production or photosynthesis (transcript-abundance change for < 3% genes under N depletion). We also achieved double-deletion of both LER1 and LER2 (from Chr 9) that total ~214 kb at maximum, which can result in slightly higher growth rate and biomass productivity than the wild-type. Therefore, loss of the large, yet 'non-essential' regions does not necessarily sacrifice important traits. Such serial targeted deletions of large genomic regions had not been previously reported in microalgae, and will accelerate crafting minimal genomes as chassis for photosynthetic production.


Assuntos
Genoma/genética , Microalgas/genética , Plasmídeos/genética , Estramenópilas/genética , Sistemas CRISPR-Cas , Engenharia Genética , Fenótipo
5.
BMC Plant Biol ; 22(1): 428, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36071408

RESUMO

BACKGROUND: Calmodulin-binding transcription activators (CAMTAs) are relatively conserved calmodulin-binding transcription factors widely found in eukaryotes and play important roles in plant growth and stress response. CAMTA transcription factors have been identified in several plant species, but the family members and functions have not yet been identified and analyzed in quinoa. RESULTS: In this study, we identified seven CAMTA genes across the whole quinoa genome and analyzed the expression patterns of CqCAMTAs in root and leaf tissues. Gene structure, protein domain, and phylogenetic analyses showed that the quinoa CAMTAs were structurally similar and clustered into the same three major groups as other plant CAMTAs. A large number of stress response-related cis-elements existed in the 2 kb promoter region upstream of the transcription start site of the CqCAMTA genes. qRT-PCR indicated that CqCAMTA genes were expressed differentially under PEG treatments in leaves, and responded to drought stress in leaves and roots. In particular, the CqCAMTA03 gene strongly responded to drought. The transient expression of CqCAMTA03-GFP fusion protein in the tobacco leaf showed that CqCAMTA03 was localized in the nucleus. In addition, transgenic Arabidopsis lines exhibited higher concentration levels of the antioxidant enzymes measured, including POD, SOD, and CAT, under drought conditions with very low levels of H2O2 and MDA. Moreover, relative water content and the degree of stomatal opening showed that the transgenic Arabidopsis lines were more tolerant of both stress factors as compared to their wild types. CONCLUSION: In this study, the structures and functions of the CAMTA family in quinoa were systematically explored. Many CAMTAs may play vital roles in the regulation of organ development, growth, and responses to drought stress. The results of the present study serve as a basis for future functional studies on the quinoa CAMTA family.


Assuntos
Arabidopsis , Secas , Arabidopsis/metabolismo , Calmodulina/metabolismo , Peróxido de Hidrogênio/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética
6.
Bioinformatics ; 37(16): 2340-2346, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-33620460

RESUMO

MOTIVATION: Cryo-Electron Tomography (cryo-ET) is a 3D bioimaging tool that visualizes the structural and spatial organization of macromolecules at a near-native state in single cells, which has broad applications in life science. However, the systematic structural recognition and recovery of macromolecules captured by cryo-ET are difficult due to high structural complexity and imaging limits. Deep learning-based subtomogram classification has played critical roles for such tasks. As supervised approaches, however, their performance relies on sufficient and laborious annotation on a large training dataset. RESULTS: To alleviate this major labeling burden, we proposed a Hybrid Active Learning (HAL) framework for querying subtomograms for labeling from a large unlabeled subtomogram pool. Firstly, HAL adopts uncertainty sampling to select the subtomograms that have the most uncertain predictions. This strategy enforces the model to be aware of the inductive bias during classification and subtomogram selection, which satisfies the discriminativeness principle in AL literature. Moreover, to mitigate the sampling bias caused by such strategy, a discriminator is introduced to judge if a certain subtomogram is labeled or unlabeled and subsequently the model queries the subtomogram that have higher probabilities to be unlabeled. Such query strategy encourages to match the data distribution between the labeled and unlabeled subtomogram samples, which essentially encodes the representativeness criterion into the subtomogram selection process. Additionally, HAL introduces a subset sampling strategy to improve the diversity of the query set, so that the information overlap is decreased between the queried batches and the algorithmic efficiency is improved. Our experiments on subtomogram classification tasks using both simulated and real data demonstrate that we can achieve comparable testing performance (on average only 3% accuracy drop) by using less than 30% of the labeled subtomograms, which shows a very promising result for subtomogram classification task with limited labeling resources. AVAILABILITY AND IMPLEMENTATION: https://github.com/xulabs/aitom. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

7.
Metab Eng ; 66: 157-166, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33823272

RESUMO

The chain length (CL) of fatty acids (FAs) is pivotal to oil property, yet to what extent it can be customized in industrial oleaginous microalgae is unknown. In Nannochloropsis oceanica, to modulate long-chain FAs (LCFAs), we first discovered a fungi/bacteria-originated polyketide synthase (PKS) system which involves a cytoplasmic acyl-ACP thioesterase (NoTE1). NoTE1 hydrolyzes C16:0-, C16:1- and C18:1-ACP in vitro and thus intercepts the specific acyl-ACPs elongated by PKS for polyunsaturated FA biosynthesis, resulting in elevation of C16/C18 monounsaturated FAs when overproduced and increase of C20 when knocked out. For medium-chain FAs (MCFAs; C8-C14), C8:0 and C10:0 FAs are boosted by introducing a Cuphea palustris acyl-ACP TE (CpTE), whereas C12:0 elevated by rationally engineering CpTE enzyme's substrate-binding pocket to shift its CL preference towards C12:0. A mechanistic model exploiting both native and engineered PKS and type II FAS pathways was thus proposed for manipulation of carbon distribution among FAs of various CL. The ability to tailor FA profile at the unit CL resolution from C8 to C20 in Nannochloropsis spp. lays the foundation for scalable production of designer lipids via industrial oleaginous microalgae.


Assuntos
Microalgas , Estramenópilas , Ácidos Graxos , Lipídeos , Microalgas/genética , Policetídeo Sintases , Estramenópilas/genética
8.
Plant Commun ; 5(3): 100773, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38007614

RESUMO

Epigenetic marks on histones and DNA, such as DNA methylation at N6-adenine (6mA), play crucial roles in gene expression and genome maintenance, but their deposition and function in microalgae remain largely uncharacterized. Here, we report a genome-wide 6mA map for the model industrial oleaginous microalga Nannochloropsis oceanica produced by single-molecule real-time sequencing. Found in 0.1% of adenines, 6mA sites are mostly enriched at the AGGYV motif, more abundant in transposons and 3' untranslated regions, and associated with active transcription. Moreover, 6mA gradually increases in abundance along the direction of gene transcription and shows special positional enrichment near splicing donor and transcription termination sites. Highly expressed genes tend to show greater 6mA abundance in the gene body than do poorly expressed genes, indicating a positive interaction between 6mA and general transcription factors. Furthermore, knockout of the putative 6mA methylase NO08G00280 by genome editing leads to changes in methylation patterns that are correlated with changes in the expression of molybdenum cofactor, sulfate transporter, glycosyl transferase, and lipase genes that underlie reductions in biomass and oil productivity. By contrast, knockout of the candidate demethylase NO06G02500 results in increased 6mA levels and reduced growth. Unraveling the epigenomic players and their roles in biomass productivity and lipid metabolism lays a foundation for epigenetic engineering of industrial microalgae.


Assuntos
Metilação de DNA , Epigenômica , Mapeamento Cromossômico , Adenina/metabolismo , Lipídeos
9.
Cancer Med ; 13(7): e7165, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38613157

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, it has a poor prognosis due to its highly invasive and metastatic nature. Consequently, identifying effective prognostic markers and potential therapeutic targets has been extensively investigated. METTL5, an 18S rRNA methyltransferase, is abnormally high in HCC. But its biological function and prognostic significance in HCC remain largely unelucidated. This study aimed to investigate the role of METTL5 in HCC progression, and elucidate its possible molecular mechanisms in HCC via transcriptome sequencing, providing new insights for identifying new HCC prognostic markers and therapeutic targets. METHODS: The METTL5 expression in HCC and paracancerous tissues was analyzed using HCC immunohistochemical microarrays and bioinformatic retrieval methods to correlate METTL5 with clinicopathological features and survival prognosis. We constructed a METTL5 knockdown hepatocellular carcinoma cell line model and an animal model to determine the effect of METTL5 on hepatocellular carcinoma progression. Subsequently, RNA sequencing was performed to analyze the molecular mechanism of METTL5 in HCC based on the sequencing results, and relevant experiments were performed to verify it. RESULTS: We found that METTL5 expression was elevated in hepatocellular carcinoma tissues and correlated with poor patient prognosis, and in the analysis of clinicopathological features showed a correlation with TNM staging. In hepatocellular carcinoma cell lines with knockdown of METTL5, the malignant biological behavior was significantly reduced both in vitro and in vivo. Based on the sequencing results as well as the results of GO functional enrichment analysis and KEGG pathway enrichment analysis, we found that METTL5 could promote the generation and release of neutrophil extracellular capture network (NETs) and might further accelerate the progression of HCC. CONCLUSION: The m6A methyltransferase METTL5 is overexpressed in hepatocellular carcinoma (HCC) and correlates with poor prognosis. METTL5 accelerates malignant progression of HCC by promoting generation and release of the neutrophil extracellular traps (NETs) network, providing new insights for clinical biomarkers and immunotherapeutic targets in HCC prognosis.


Assuntos
Adenina , Carcinoma Hepatocelular , Armadilhas Extracelulares , Neoplasias Hepáticas , Animais , Humanos , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Metiltransferases/genética
10.
Int J Biol Macromol ; 253(Pt 8): 127582, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37866580

RESUMO

Quinoa is a crop with high nutritional value and strong stress resistance. AP2/ERF transcription factors play a key role in plant growth and development. In this study, 148 AP2/ERF genes were identified in quinoa, which were divided into 5 subfamilies, including ERF, AP2, DREB, RAV and Soloist. The results showed that the number of introns ranged from 0 to 11, and the Motif 1-Motif 4 was highly conserved in most CqAP2/ERF proteins. The 148 CqAP2/ERF genes were distributed on 19 chromosomes. There were 93 pairs of duplicating genes in this family, and gene duplication played a critical role in the expansion of this family. Protein-protein interaction indicated that the proteins in CqAP2/ERF subfamily exhibited complex interactions, and GO enrichment analysis indicated that 148 CqAP2/ERF proteins were involved in transcription factor activity. In addition, CqAP2/ERF gene contains a large number of elements related to hormones in promoter region (IAA, GA, SA, ABA and MeJA) and stresses (salt, drought, low temperature and anaerobic induction). Transcriptome analysis under drought stress indicated that most of the CqAP2/ERF genes were responsive to drought stress, and subcellular localization indicated that CqERF24 was location in the nucleus, qRT-PCR results also showed that most of the genes such as CqERF15, CqERF24, CqDREB03, CqDREB14, CqDREB37 and CqDREB43 also responded to drought stress in roots and leaves. Overexpression of CqERF24 in Arabidopsis thaliana enhanced drought resistance by increasing antioxidant enzyme activity and activation-related stress genes, and the gene is sensitive to ABA, while silencing CqERF24 in quinoa decreased drought tolerance. In addition, overexpression of CqERF24 in quinoa calli enhanced resistance to mannitol. These results lay a solid foundation for further study on the role of AP2/ERF family genes in quinoa under drought stress.


Assuntos
Chenopodium quinoa , Chenopodium quinoa/genética , Secas , Duplicação Gênica , Perfilação da Expressão Gênica/métodos , Íntrons , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Filogenia , Regulação da Expressão Gênica de Plantas
11.
J Int Med Res ; 49(4): 300060521990512, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33845647

RESUMO

OBJECTIVE: To explore the relationships between hepatocellular carcinoma (HCC) and the expression of RNA polymerase II subunit 3 (RPB3) and vesicular, overexpressed in cancer, prosurvival protein 1 (VOPP1), and to determine whether RPB3 regulates VOPP1 expression to promote HCC cell proliferation, tumor growth, and tumorigenesis. METHODS: HCC and adjacent liver samples were collected from 51 patients with HCC who underwent surgical excision between September 20, 2010 and June 22, 2017. Immunohistochemical staining, western blot, quantitative PCR, plate colony assay, and RNA microarray were used to detect relevant indexes for further analyses. RESULTS: VOPP1 was shown to function as a target gene of RPB3 in facilitating HCC proliferation, and was downregulated after RBP3 silencing. Additionally, hepatic tumor tissues demonstrated high VOPP1 expression. Furthermore, VOPP1 silencing suppressed tumor growth and cell proliferation and elicited apoptosis. CONCLUSION: RPB3 regulates VOPP1 expression to promote HCC cell proliferation, tumor growth, and tumorigenesis.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , RNA Polimerase II , Fatores de Transcrição , Apoptose , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/genética
12.
J Int Med Res ; 49(10): 3000605211047278, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34617814

RESUMO

OBJECTIVE: To investigate the clinical significance of human leukocyte antigen (HLA)-E levels in oesophageal squamous cell carcinoma (ESCC). METHODS: The levels of HLA-E immunostaining in ESCC lesions and 47 corresponding adjacent normal tissues were measured using immunohistochemistry. The correlation between the levels of immunostaining and clinical parameters was analysed. RESULTS: This study analysed 110 paraffin-embedded primary tumour lesions and 47 case-controlled paracancerous tissues that were surgically resected from 110 patients with ESCC. Positive immunostaining for HLA-E was observed in 88.2% (97 of 110) of ESCC lesions and 29.8% (14 of 47) of normal oesophageal tissues. There was no correlation between HLA-E immunostaining in ESCC lesions and clinicopathological characteristics such as lymph node metastasis, tumour-node-metastasis stage and differentiation grade. Kaplan-Meier survival analysis revealed a significantly better prognosis in patients with higher levels of HLA-E immunostaining than in those with lower levels of HLA-E immunostaining; overall survival was 28.6 months (95% confidence interval [CI], 23.2, 34.0) versus 15.3 months (95% CI, 11.5, 19.1), respectively. Furthermore, multivariate analysis showed that the HLA-E level was an independent prognostic factor in patients with ESCC. CONCLUSION: A higher level of HLA-E immunostaining was associated with favourable survival in patients with ESCC.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Carcinoma de Células Escamosas/diagnóstico , Neoplasias Esofágicas/diagnóstico , Antígenos HLA , Humanos , Prognóstico
13.
Eur J Pharmacol ; 900: 174046, 2021 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-33745958

RESUMO

This study is designed to investigate the role of novel protein kinases C (nPKC) in mediating pulmonary artery smooth muscle cells (PASMCs) proliferation in pulmonary hypertension (PH) and the underlying mechanisms. Mouse PASMCs was isolated using magnetic separation technology. The PASMCs were divided into 24 h group, 48 h group and 72 h group according to different hypoxia treatment time, then detected cell proliferation rate and nPKC expression level in each group. We treated PASMCs with agonists or inhibitors of PKCdelta (PKCδ) and PKCepsilon (PKCε) and exposed them to hypoxia or normoxia for 72 h, then measured the proliferation of PASMCs. We also constructed a lentiviral vector containing siRNA fragments for inhibiting PKCδ and PKCε to transfected PASMCs, then examined their proliferation. PASMCs isolated successfully by magnetic separation method and were in good condition. Hypoxia promoted the proliferation of PASMCs, and the treatment for 72 h had the most significant effect. Hypoxia upregulated the expression of PKCδ and PKCε in mouse PASMCs, leading to PASMCs proliferation. Moreover, Our study demonstrated that hypoxia induced upregulation of PKCδ and PKCε expression resulting to the proliferation of PASMCs via up-regulating the phosphorylation of AKT and ERK. Our study provides clear evidence that increased nPKC expression contributes to PASMCs proliferation and uncovers the correlation between AKT and ERK pathways and nPKC-mediated proliferation of PASMCs. These findings may provide novel targets for molecular therapy of pulmonary hypertension.


Assuntos
Hipóxia Celular/fisiologia , Hipertensão Pulmonar/patologia , Miócitos de Músculo Liso , Proteína Quinase C/biossíntese , Artéria Pulmonar/patologia , Animais , Proliferação de Células , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína Oncogênica v-akt/efeitos dos fármacos , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C-delta/efeitos dos fármacos , Proteína Quinase C-épsilon/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Regulação para Cima/fisiologia
14.
J Nanosci Nanotechnol ; 10(1): 421-5, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20352872

RESUMO

Using acetylene black as an assistant reagent in the ammonia atmosphere, one dimensional (1D) hexagonal single crystalline aluminum nitride (AIN) nanowires were successfully synthesized via carbothermal reduction and nitridation method. With smooth surface and uniform diameter, the wool-like product of AIN nanowires grow along [001] direction and are 80-120 nm in diameter and several tens micrometers in length. According to thermodynamic and kinetic analysis, AI2O3 initially was reduced to a volatile suboxide gas Al2O at 1800 degrees C. Then gaseous Al2O was transported by N2/NH3 mixtures to about 1200 degrees C, where 1D AIN nanowires formed by the reaction of Al2O gas, graphite and NH3. Due to high surface area, small particle size and amorphous structure, acetylene black maybe possess more active sites and more effective contact area, which benefits the first step reaction. The electrostatic polar charge model and crystallographic characteristics are employed to explain the growth mechanism of AIN nanowires. To our knowledge, acetylene black is the first time to be used for synthesizing 1D AIN nanostructures via carbothermal reduction and nitridation method, which would be an efficient, economical assistant reagent for fabricating nitride nanostructures.

15.
World J Gastroenterol ; 26(11): 1156-1171, 2020 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-32231420

RESUMO

BACKGROUND: Intestinal inflammation is a common digestive tract disease, which is usually treated with hormone medicines. Hormone medicines are effective to some extent, but long-term use of them may bring about many complications. AIM: To explore the protective effects of panax notoginseng saponin (PNS) against dextran sulfate sodium (DSS)-induced intestinal inflammatory injury through phosphoinositide-3-kinase protein kinase B (PI3K/AKT) signaling pathway inhibition in rats. METHODS: Colitis rat models were generated via DSS induction, and rats were divided into control (no modeling), DSS, DSS + PNS 50 mg/k, and DSS + PNS 100 mg/kg groups. Then, the intestinal injury, oxidative stress parameters, inflammatory indices, tight junction proteins, apoptosis, macrophage polarization, and TLR4/AKT signaling pathway in colon tissues from rats in each of the groups were detected. The PI3K/AKT signaling pathway in the colon tissue of rats was blocked using the PI3K/AKT signaling pathway inhibitor, LY294002. RESULTS: Compared with rats in the control group, rats in the DSS group showed significantly shortened colon lengths, and significantly increased disease activity indices, oxidative stress reactions and inflammatory indices, as well as significantly decreased expression of tight junction-associated proteins. In addition, the DSS group showed significantly increased apoptotic cell numbers, and showed significantly increased M1 macrophages in spleen and colon tissues. They also showed significantly decreased M2 macrophages in colon tissues, as well as activation of the PI3K/AKT signaling pathway (all P < 0.05). Compared with rats in the DSS group, rats in the DSS + PNS group showed significantly lengthened colon lengths, decreased disease activity indices, and significantly alleviated oxidative stress reactions and inflammatory responses. In addition, this group showed significantly increased expression of tight junction-associated proteins, significantly decreased apoptotic cell numbers, and significantly decreased M1 macrophages in spleen and colon tissues. This group further showed significantly increased M2 macrophages in colon tissues, and significantly suppressed activation of the PI3K/AKT signaling pathway, as well as a dose dependency (all P < 0.05). When the PI3K/AKT signaling pathway was inhibited, the apoptosis rate of colon tissue cells in the DSS + LY294002 group was significantly lower than that of the DSS group (P < 0.05). CONCLUSION: PNS can protect rats against DSS-induced intestinal inflammatory injury by inhibiting the PI3K/AKT signaling pathway, and therefore may be potentially used in the future as a drug for colitis.


Assuntos
Colite/prevenção & controle , Panax notoginseng/química , Substâncias Protetoras/farmacologia , Saponinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Administração Oral , Animais , Colite/induzido quimicamente , Colite/imunologia , Colite/patologia , Colo/efeitos dos fármacos , Colo/imunologia , Colo/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Humanos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilinositol 3-Quinase/metabolismo , Substâncias Protetoras/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Saponinas/uso terapêutico
16.
World J Gastroenterol ; 26(1): 55-69, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31933514

RESUMO

BACKGROUND: Ulcerative colitis (UC) is a main form of inflammatory bowel disease. Due to complicated etiology and a high rate of recurrence, it is quite essential to elucidate the underlying mechanism of and search for effective therapeutic methods for UC. AIM: To investigate the effects of astragalus polysaccharides (APS) combined with matrine on UC and associated lung injury. METHODS: UC was induced in rats by colon mucosal tissue sensitization combined with trinitro-benzene-sulfonic acid-ethanol. Then, the effects of the treatments of salazopyrine, APS, matrine, and APS combined with matrine on histopathological changes of lung and colon tissues, disease activity index (DAI), colon mucosal damage index (CMDI), serum endotoxin (ET) level, serum diamine oxidase (DAO) activity, the contents of tumor necrosis factor-α and interleukin-1ß, and the activities of myeloperoxidase, superoxide dismutase, and malondialdehyde in lung tissues, as well as the protein expression of zonula occludens (ZO)-1, Occludin, and trefoil factor 3 (TFF3) were detected in UC rats. RESULTS: The treatments of salazopyrine, APS, matrine, and APS combined with matrine reduced DAI scores and improved histopathological changes of colon and lung tissues, as well as decreased CMDI scores, ET levels, and DAO activities in UC rats. Moreover, in lung tissues, inflammatory response and oxidative stress injury were relieved after the treatments of salazopyrine, APS, matrine, and APS combined with matrine in UC rats. Furthermore, the expression of ZO-1, Occludin, and TFF3 in lung and colon tissues was increased after different treatments in UC rats. Notably, APS combined with matrine exerted a better protective effect against UC and lung injury compared with other treatments. CONCLUSION: APS combined with matrine exert a synergistic protective effect against UC and lung injury, which might be associated with regulating TFF3 expression.


Assuntos
Alcaloides/farmacologia , Astrágalo/química , Colite Ulcerativa/tratamento farmacológico , Lesão Pulmonar/tratamento farmacológico , Polissacarídeos/farmacologia , Substâncias Protetoras/farmacologia , Quinolizinas/farmacologia , Animais , Colite Ulcerativa/induzido quimicamente , Colo/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Lesão Pulmonar/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ácido Trinitrobenzenossulfônico , Matrinas
17.
ANZ J Surg ; 88(6): E522-E525, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28803451

RESUMO

BACKGROUND: We evaluated the feasibility and efficacy of laparoscopic hepatectomy (LH) combined with endoscopic papillary balloon dilation (EPBD) for removing intra- and extrahepatic bile duct stones. METHODS: A total of 26 patients with intra- and extrahepatic bile duct stones underwent LH and EPBD. Selective hemi-hepatic vascular occlusion was used to complete the LH. EPBD was performed under the guidance of a guidewire, and stones were removed with a stone basket or balloon. RESULTS: A one-stage LH with EPBD lithotomy was successfully performed in 26 cases. No residual bile duct stones, intestinal or bile duct perforations were found. In addition, no severe post-operative bleeding, severe pancreatitis or mortality occurred. Post-operative hyperamylasemia was observed in five cases and bile leakage in one case. Post-operative hospital stays lasted 7-11 days. CONCLUSION: LH combined with EPBD applied to intra- and extrahepatic bile duct stones was feasible, effective and safe, resulting in rapid recovery and few post-operative complications.


Assuntos
Colangiopancreatografia Retrógrada Endoscópica/métodos , Cálculos Biliares/diagnóstico por imagem , Cálculos Biliares/cirurgia , Hepatectomia/métodos , Laparoscopia/métodos , Adulto , Ductos Biliares Extra-Hepáticos/diagnóstico por imagem , Ductos Biliares Extra-Hepáticos/cirurgia , Ductos Biliares Intra-Hepáticos/diagnóstico por imagem , Ductos Biliares Intra-Hepáticos/cirurgia , Estudos de Coortes , Terapia Combinada , Dilatação/métodos , Feminino , Seguimentos , Humanos , Tempo de Internação , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Segurança do Paciente , Estudos Prospectivos , Medição de Risco , Resultado do Tratamento
18.
Onco Targets Ther ; 10: 1191-1198, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28280353

RESUMO

Increasing evidence has demonstrated that aberrant expressions of long non-coding RNAs (lncRNAs) are involved in various malignancies, including hepatocellular carcinoma (HCC). This study aimed to investigate the role of lncRNA colon cancer-associated transcript 2 (CCAT2) in the progression of HCC. Quantitative real-time polymerase chain reaction analysis confirmed that CCAT2 was upregulated in HCC cell lines and cancerous tissues compared with normal liver cell line and adjacent normal tissue samples. The level of CCAT2 was positively associated with tumor-node-metastasis stages and vessel invasion. Survival analyses revealed that high CCAT2 expression predicted poor prognostic outcomes, serving as an independent prognostic factor for HCC patients. Patients with high CCAT2 expression had a 1.849-fold increased risk of death compared with those with low CCAT2 expression. Moreover, we also found that knockdown of CCAT2 expression reduced cell migration and invasion in vitro. We further demonstrated that CCAT2 played a key role in enhancing the epithelial-mesenchymal transition (EMT) through the regulation of vimentin, E-cadherin and transcription factor snail2 expression. Taken together, our findings showed that high CCAT2 expression is associated with poor survival in HCC patients. CCAT2 promotes HCC progression by regulating Snail2-induced EMT. CCAT2 may be a prognostic biomarker and therapeutic target for HCC.

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