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1.
Nat Immunol ; 24(11): 1813-1824, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37813965

RESUMO

Kupffer cells, the liver tissue resident macrophages, are critical in the detection and clearance of cancer cells. However, the molecular mechanisms underlying their detection and phagocytosis of cancer cells are still unclear. Using in vivo genome-wide CRISPR-Cas9 knockout screening, we found that the cell-surface transmembrane protein ERMAP expressed on various cancer cells signaled to activate phagocytosis in Kupffer cells and to control of liver metastasis. ERMAP interacted with ß-galactoside binding lectin galectin-9 expressed on the surface of Kupffer cells in a manner dependent on glycosylation. Galectin-9 formed a bridging complex with ERMAP and the transmembrane receptor dectin-2, expressed on Kupffer cells, to induce the detection and phagocytosis of cancer cells by Kupffer cells. Patients with low expression of ERMAP on tumors had more liver metastases. Thus, our study identified the ERMAP-galectin-9-dectin-2 axis as an 'eat me' signal for Kupffer cells.


Assuntos
Citofagocitose , Células de Kupffer , Humanos , Fagocitose/genética , Galectinas/genética , Galectinas/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo
2.
Ann Surg ; 277(4): e948-e954, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35166263

RESUMO

OBJECTIVE: The aim of this study was to study the association of perioperative administration of renin angiotensin system inhibitors (RASi) and clinical outcomes of patients with heart failure (HF) undergoing cardiac surgery. SUMMARY BACKGROUND DATA: It is controversial whether the perioperative RASi should be administered in HF patients undergoing cardiac surgery. METHODS: A total of 2338 patients with HF and undergoing CABG and/or valve surgeries at multiple hospitals from 2001 to 2015 were identified from STS database. After adjustment using propensity score and instrumental variable, logistic regression was conducted to analyze the influence of preoperative continuation of RASi (PreRASi) on short-term in-hospital outcomes. Independent risk factors of 30-day mortality, major adverse cardiovascular events (MACE), and renal failure were analyzed by use of stepwise logistic regression. The effects of pre- and postoperative use of RASi (PostRASi) on long-term mortality were analyzed using survival analyses. Stepwise Cox regression was conducted to analyze the independent risk factors of 6-year mortality. The relationships of HF status and surgery type with perioperative RASi, as well as PreRASi-PostRASi, were also evaluated by subgroup analyses. RESULTS: PreRASi was associated with lower incidences of 30-day mortality [ P < 0.0001, odds ratio (OR): 0.556, 95% confidence interval (CI) 0.405-0.763], stroke ( P =0.035, OR: 0.585, 95% CI: 0.355-0.962), renal failure ( P =0.007, OR: 0.663, 95% CI: 0.493-0.894). Both PreRASi ( P =0.0137) and PostRASi ( P =0.007) reduced 6-year mortality compared with the No-RASi groups. CONCLUSIONS: Pre- and postoperative use of RASi was associated with better outcomes for the patients who have HF and undergo CABG and/or valve surgeries. Preoperative continuation and postoperative restoration are warranted in these patients.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Insuficiência Cardíaca , Insuficiência Renal , Humanos , Sistema Renina-Angiotensina , Estudos de Coortes , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Insuficiência Cardíaca/cirurgia
3.
Endoscopy ; 55(11): 1037-1042, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37339664

RESUMO

BACKGROUND : Selective biliary cannulation is the most challenging step in endoscopic retrograde cholangiopancreatography (ERCP) because only indirect radiographic images can be obtained. Therefore, we developed a novel endoscopic retrograde direct cholangioscopy (ERDC) technology to facilitate visible biliary cannulation. METHODS : In this case series, we used ERDC to treat 21 patients with common bile duct stones who were enrolled consecutively between July 2022 and December 2022. The procedure details and complications were recorded, and all patients were followed up for 3 months after the procedure. The learning curve effect was analyzed by comparing the early and later cases. RESULTS : Biliary cannulation was successful in all patients, and the stones were removed completely. The median (interquartile range [IQR]) time for cholangioscopy-guided biliary cannulation was 240.0 (10.0-430.0) seconds, and the median (IQR) number of cannulation procedures was 2 (1-5). Despite there being one episode of post-ERCP pancreatitis, one of cholangitis, and three patients developing asymptomatic hyperamylasemia, all of the patients recovered after symptomatic treatment, being discharged and with no serious adverse events occurring during the 3-month follow-up period. Compared with the early cases, the number of intubations and the use of guidewire guidance decreased in later cases. CONCLUSION : Our research confirms that ERDC is a feasible technology for biliary cannulation under direct vision.


Assuntos
Colangiopancreatografia Retrógrada Endoscópica , Pancreatite , Humanos , Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Colangiopancreatografia Retrógrada Endoscópica/métodos , Cateterismo/métodos , Pancreatite/etiologia , Esfinterotomia Endoscópica/métodos
4.
BMC Neurol ; 22(1): 429, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36380279

RESUMO

BACKGROUND: C1q/TNF-related protein 9 (CTRP9) and adiponectin (APN) have beneficial metabolic regulatory and vasoprotective effects. This study explored alteration of CTRP9 and APN multimers during onset of ischemic stroke and development, to provide novel clinical and experimental basis for recognition and prevention of ischemic stroke. METHODS: There were 269 patients with ischemic stroke and 182 control subjects included in this study. Serum levels of CTRP9 and APN multimers in different disease stages were measured. RESULTS: Serum CTRP9, total APN (tAPN), and high-molecular weight (HMW) APN decreased gradually in stage I (acute stage, within 72 h of onset) of ischemic stroke and increased during stage III (11th day to one month) and stage IV (1 month after), compared to control. In the non-hyperlipidemia group, serum CTRP9, tAPN, and HMW were decreased in ischemic stroke patients compared to control (P < 0.05). Serum CTRP9 is closely related to serum tAPN and HMW (r = 0.992, 0.991). Serum CTRP9 are protective against ischemic stroke (OR = 0.400, 95% CI 0.197-0.810, P < 0.05). CONCLUSIONS: Lower serum CTRP9, tAPN, LMW, and HMW are significantly associated with increased ischemic stroke risk in non-hyperlipidemia subjects. CTRP9, tAPN, and HMW isoforms may be valuable clinical indicators for patients with ischemic stroke.


Assuntos
Adiponectina , AVC Isquêmico , Humanos , Adiponectina/metabolismo , Glicoproteínas/metabolismo , Peso Molecular
5.
Cell Mol Biol (Noisy-le-grand) ; 67(2): 138-141, 2021 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-34817326

RESUMO

Nitric oxide (NO), as a free radical, is produced by inflamed microglia cells and is one of the destructive factors of the immune system and a factor in myelin degradation. Therefore, inhibition of microglia activity is a chief strategy in reducing neurotoxic damage to the central nervous system. In this study, an herbal Immunomodulatory Drug (IMOD) was used to evaluate the effects of this drug in controlling the amount of nitric oxide. Nitric oxide induction was performed by bacterial lipopolysaccharide (LPS) in rat inflamed microglial cell line, CHME-5. ELISA test was used to measure the produced nitric oxide at 24, 48, and 72 hours. The results showed that the high concentrations of IMOD (1.2, and 4% V/V) had anti-inflammatory effects on microglial cells and were able to reduce the amount of nitric oxide in these cells but the effective dose of IMOD was in the range of 1.2% V/V. Therefore, the safest dose and the best time for the effect of IMOD on inflammatory cell groups are 1.2% V/V and 72h, respectively. Hence, with further studies, IMOD can be considered as an herbal anti-inflammatory drug that is effective in controlling neurodegenerative diseases.


Assuntos
Agentes de Imunomodulação/farmacologia , Microglia/efeitos dos fármacos , Óxido Nítrico/biossíntese , Extratos Vegetais/farmacologia , Plantas Medicinais/química , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Linhagem Celular , Relação Dose-Resposta a Droga , Agentes de Imunomodulação/química , Lipopolissacarídeos/farmacologia , Microglia/citologia , Microglia/metabolismo , Extratos Vegetais/química , Ratos , Fatores de Tempo
6.
Aesthetic Plast Surg ; 45(6): 3037-3044, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34184094

RESUMO

BACKGROUND: Both keloid and hypertrophic scars are common benign skin lesions manifested by hyperplasia of fibroblasts. Clinically, this will not only have physiological effects on patients, but also cause psychological damage. However, there is no unified standard treatment method at present. Intralesional corticosteroid injection alone and corticosteroid combined with botulinum toxin type A has been gradually found to be useful for the treatment of keloid and hypertrophic scars, but the difference in efficacy between the two is controversial. METHODS: A systematic search was made of the relevant experiments from Web of Science, PubMed, Scopus, Google Scholar, Cochrane Library, and China National Knowledge Infrastructure (CNKI). RESULTS: The scores of Visual Analog Scale (VAS), Vancouver Scar Score sheet (VSS), scar thickness, itching degree and patient satisfaction after the combination of corticosteroid and botulinum toxin type A were superior than those after corticosteroid (P<0.05). CONCLUSION: Compared with corticosteroid alone, corticosteroid combined with botulinum toxin type A is more effective in the treatment of keloid and hypertrophic scar. Although clinical case studies for the treatment of keloid or hypertrophic scars are limited, it is necessary and helpful to understand the effectiveness of corticosteroid combined with botulinum toxin type A in the treatment of keloid or hypertrophic scars. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Assuntos
Toxinas Botulínicas Tipo A , Cicatriz Hipertrófica , Queloide , Corticosteroides/uso terapêutico , Toxinas Botulínicas Tipo A/uso terapêutico , Cicatriz Hipertrófica/tratamento farmacológico , Cicatriz Hipertrófica/patologia , Humanos , Injeções Intralesionais , Queloide/tratamento farmacológico , Queloide/patologia , Resultado do Tratamento
11.
Tumour Biol ; 36(9): 7017-26, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25861751

RESUMO

Renal cell carcinoma (RCC) is one of most malignant neoplasms, exhibiting poor responsiveness to the conventional chemo-regime. Abnormal expression of P-glycoprotein (P-gp) has been implicated in the emergence of multiple-drug resistance (MDR) by reducing the accumulation of intracellular chemotherapy drugs. Wnt signaling plays critical roles in renal cancer and is triggered by binding of Wnt ligands to Frizzled (FZD) receptor proteins. miR-124 is a tumor suppressor associated with cancer relapse and MDR, whereas its role in P-gp-mediated MDR in refractory RCC is as yet unrevealed. Our study aimed to investigate the roles of miR-124 in chemo-resistant RCC cells and the potential targeted signaling paths in inducing P-gp expression. Doxorubicin (DOX)- and vinblastine (VBL)-resistant Caki-2 cells were developed by exposure of parental Caki-2 cells to the agents over a long period of time. In comparison with their parental cells, miR-124 was downregulated in Caki-2/DOX and Caki-2/VBL cells, accompanied by increased FZD5 and P-gp. IC50 values were reduced significantly after miR-124 mimics were introduced into Caki-2/DOX cells. In addition, miR-124 mimics significantly promoted apoptosis of Caki-2/DOX cells. miR-124 targeted to FZD5 and miR-124 mimics as well as FZD5 siRNA showed significant inhibitory effects on P-gp expression in Caki-2/DOX cells. Furthermore, Wnt-5a dose-dependently stimulated the presentation of p-PKCα/ßII and p-CamKII via activating FZD5, which was reversed by FZD5 silencing. Moreover, FZD5/protein kinase C (PKC) signaling is responsible for the elevation of P-gp and cancer cell survival. In conclusion, restoring miR-124 may function as a promising strategy to overcome P-gp-mediated MDR by inhibiting FZD5/PKC signaling.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Carcinoma de Células Renais/genética , Receptores Frizzled/biossíntese , MicroRNAs/genética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Carcinoma de Células Renais/tratamento farmacológico , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Resistencia a Medicamentos Antineoplásicos/genética , Receptores Frizzled/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Recidiva Local de Neoplasia , Proteína Quinase C/biossíntese , Proteínas Proto-Oncogênicas/biossíntese , Vimblastina/administração & dosagem , Proteínas Wnt/biossíntese , Via de Sinalização Wnt/efeitos dos fármacos , Proteína Wnt-5a
14.
Anticancer Drugs ; 24(8): 810-7, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23744557

RESUMO

Renal cell carcinoma (RCC) ranks among the most chemoresistant tumors, and P-glycoprotein (P-gp) predominates multidrug resistance mechanisms by reducing the accumulation of intracellular chemotherapy drugs such as vinblastine (VBL), which is considered the most effective chemotherapeutic agent for this neoplasia. Unfortunately, the mechanism by which the expression of P-gp is regulated and the ways to inhibit the function of P-gp are poorly understood. Our study was carried out to determine the possible role of CCN1 in P-pg-mediated drug resistance on the basis of the validated function of CCN1, an extracellular matrix protein, in promoting chemoresistance. As expected, CCN1 was overexpressed in VBL-resistant cell lines (ACHN/VBL, A498/VBL, Caki-1/VBL, and Caki-2/VBL) as measured by enzyme-linked immunosorbent assay. We then transfected non-VBL-resistant cell lines with Ad-CCN1 and observed that the IC50 of VBL increased by about 3-5 times. Furthermore, both CCN1 antibody neutralization and αvß3 integrin antibody blockade decreased the IC50 of VBL, which showed that CCN1 and αvß3 are associated with resistance to VBL in RCC. Simultaneously, the enhanced expression of CCN1 triggered the intracellular PI3K/Akt pathway by binding αvß3 integrin, as shown by western blot. P-gp expression was augmented in response to activation of the PI3K/Akt pathway, which could be modified by PI3K inhibitor LY294002 or multidrug resistance siRNA transfection. Therefore, targeted restraint of CCN1 or αvß3 integrin in combination with the administration of VBL may be beneficial in the treatment of primary and metastatic RCC.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos Fitogênicos/farmacologia , Carcinoma de Células Renais/metabolismo , Proteína Rica em Cisteína 61/metabolismo , Resistencia a Medicamentos Antineoplásicos , Integrina alfaVbeta3/metabolismo , Neoplasias Renais/metabolismo , Vimblastina/farmacologia , Subfamília B de Transportador de Cassetes de Ligação de ATP , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/genética , Western Blotting , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Proteína Rica em Cisteína 61/genética , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Células HEK293 , Humanos , Concentração Inibidora 50 , Neoplasias Renais/genética , Neoplasias Renais/patologia , Fosfatidilinositol 3-Quinase/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , Transdução de Sinais , Transfecção
15.
Gastroenterol Rep (Oxf) ; 11: goac081, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36686571

RESUMO

Background: In colonoscopy screening for colorectal cancer, human vision limitations may lead to higher miss rate of lesions; artificial intelligence (AI) assistance has been demonstrated to improve polyp detection. However, there still lacks direct evidence to demonstrate whether AI is superior to trainees or experienced nurses as a second observer to increase adenoma detection during colonoscopy. In this study, we aimed to compare the effectiveness of assistance from AI and human observer during colonoscopy. Methods: A prospective multicenter randomized study was conducted from 2 September 2019 to 29 May 2020 at four endoscopy centers in China. Eligible patients were randomized to either computer-aided detection (CADe)-assisted group or observer-assisted group. The primary outcome was adenoma per colonoscopy (APC). Secondary outcomes included polyp per colonoscopy (PPC), adenoma detection rate (ADR), and polyp detection rate (PDR). We compared continuous variables and categorical variables by using R studio (version 3.4.4). Results: A total of 1,261 (636 in the CADe-assisted group and 625 in the observer-assisted group) eligible patients were analysed. APC (0.42 vs 0.35, P = 0.034), PPC (1.13 vs 0.81, P < 0.001), PDR (47.5% vs 37.4%, P < 0.001), ADR (25.8% vs 24.0%, P = 0.464), the number of detected sessile polyps (683 vs 464, P < 0.001), and sessile adenomas (244 vs 182, P = 0.005) were significantly higher in the CADe-assisted group than in the observer-assisted group. False detections of the CADe system were lower than those of the human observer (122 vs 191, P < 0.001). Conclusions: Compared with the human observer, the CADe system may improve the clinical outcome of colonoscopy and reduce disturbance to routine practice (Chictr.org.cn No.: ChiCTR1900025235).

16.
Am J Hum Genet ; 84(3): 418-23, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19268274

RESUMO

Low lean body mass (LBM) is related to a series of health problems, such as osteoporotic fracture and sarcopenia. Here we report a genome-wide association (GWA) study on LBM variation, by using Affymetrix 500K single-nucleotide polymorphism (SNP) arrays. In the GWA scan, we tested 379,319 eligible SNPs in 1,000 unrelated US whites and found that two SNPs, rs16892496 (p = 7.55 x 10(-8)) and rs7832552 (p = 7.58 x 10(-8)), within the thyrotropin-releasing hormone receptor (TRHR) gene were significantly associated with LBM. Subjects carrying unfavorable genotypes at rs16892496 and rs7832552 had, on average, 2.70 and 2.55 kg lower LBM, respectively, compared to those with alternative genotypes. We replicated the significant associations in three independent samples: (1) 1488 unrelated US whites, (2) 2955 Chinese unrelated subjects, and (3) 593 nuclear families comprising 1972 US whites. Meta-analyses of the GWA scan and the replication studies yielded p values of 5.53 x 10(-9) for rs16892496 and 3.88 x 10(-10) for rs7832552. In addition, we found significant interactions between rs16892496 and polymorphisms of several other genes involved in the hypothalamic-pituitary-thyroid and the growth hormone-insulin-like growth factor-I axes. Results of this study, together with the functional relevance of TRHR in muscle metabolism, support the TRHR gene as an important gene for LBM variation.


Assuntos
Composição Corporal/genética , Peso Corporal/genética , Receptores do Hormônio Liberador da Tireotropina/genética , Adulto , Idoso , Asiático , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Receptores do Hormônio Liberador da Tireotropina/metabolismo , Magreza , População Branca
17.
Am J Hum Genet ; 84(3): 388-98, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19249006

RESUMO

To identify and validate genes associated with bone mineral density (BMD), which is a prominent osteoporosis risk factor, we tested 379,319 SNPs in 1000 unrelated white U.S. subjects for associations with BMD. For replication, we genotyped the most significant SNPs in 593 white U.S. families (1972 subjects), a Chinese hip fracture (HF) sample (350 cases, 350 controls), a Chinese BMD sample (2955 subjects), and a Tobago cohort of African ancestry (908 males). Publicly available Framingham genome-wide association study (GWAS) data (2953 whites) were also used for in silico replication. The GWAS detected two BMD candidate genes, ADAMTS18 (ADAM metallopeptidase with thrombospondin type 1 motif, 18) and TGFBR3 (transforming growth factor, beta receptor III). Replication studies verified the significant findings by GWAS. We also detected significant associations with hip fracture for ADAMTS18 SNPs in the Chinese HF sample. Meta-analyses supported the significant associations of ADAMTS18 and TGFBR3 with BMD (p values: 2.56 x 10(-5) to 2.13 x 10(-8); total sample size: n = 5925 to 9828). Electrophoretic mobility shift assay suggested that the minor allele of one significant ADAMTS18 SNP might promote binding of the TEL2 factor, which may repress ADAMTS18 expression. The data from NCBI GEO expression profiles also showed that ADAMTS18 and TGFBR3 genes were differentially expressed in subjects with normal skeletal fracture versus subjects with nonunion skeletal fracture. Overall, the evidence supports that ADAMTS18 and TGFBR3 might underlie BMD determination in the major human ethnic groups.


Assuntos
Proteínas ADAM/genética , Povo Asiático , População Negra , Densidade Óssea/genética , Proteoglicanas/genética , Receptores de Fatores de Crescimento Transformadores beta/genética , População Branca , Proteínas ADAMTS , Adulto , Idoso , Bases de Dados Genéticas , Feminino , Seguimentos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Fraturas do Quadril/etnologia , Fraturas do Quadril/etiologia , Fraturas do Quadril/genética , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/complicações , Osteoporose/etnologia , Osteoporose/genética , Polimorfismo de Nucleotídeo Único , Adulto Jovem
18.
J Hum Genet ; 57(1): 33-7, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22048656

RESUMO

Lean body mass (LBM) is a heritable trait predicting a series of health problems, such as osteoporotic fracture and sarcopenia. We aim to identify sequence variants associated with LBM by a genome-wide association study (GWAS) of copy number variants (CNVs). We genotyped genome-wide CNVs of 1627 individuals of the Chinese population with Affymetrix SNP6.0 genotyping platform, which comprised of 9 40 000 copy number probes. We then performed a GWAS of CNVs with lean mass at seven sites: left and right arms, left and right legs, total of limb, trunk and whole body. We identified a CNV that is associated with LBM variation at the genome-wide significance level (CNV2073, Bonferroni corrected P-value 0.002 at right arm). CNV2073 locates at chromosome 15q13.3, which has been implicated as a candidate region for LBM by our previous linkage studies. The nearest gene, gremlin1, has a key role in the regulation of skeletal muscle formation and repair. Our results suggest that the gremlin1 gene is a potentially important gene for LBM variation. Our findings also show the utility and efficacy of CNV as genetic markers in association studies.


Assuntos
Peso Corporal/genética , Variações do Número de Cópias de DNA/genética , Estudos de Associação Genética , Estudo de Associação Genômica Ampla , Peptídeos e Proteínas de Sinalização Intercelular/genética , Magreza/genética , Adulto , Feminino , Humanos , Masculino
19.
Physiol Plant ; 145(3): 384-94, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22380525

RESUMO

The 'stage albinism line of winter wheat' FA85 exhibits a severe block in chlorophyll (Chl) biosynthesis with prolonged low-temperature treatment. The correlations between leaf color and low temperature provide more comprehensive understanding of low temperature as an environmental signal that regulate the metabolic changes in the entire Chl-synthesizing pathway. In this study, we investigated differences in Chl biosynthesis between leaves of Aibian1 and FA85 by measuring their Chl precursors and heme content, transcripts for key genes of Chl biosynthesis and key enzyme activities. With prolonged low-temperature treatment, the Chl content gradually decreased, but Chl precursors, including protoporphyrin IX, Mg-protoporphyrin IX and protochlorophyllide (Pchlide), simultaneously accumulated. Parallel to the decline in Chl content, the protoporphyrin IX distribution toward Chl synthesis was less than that in heme synthesis in the leaves of FA85. Corresponding to the change of protoporphyrin IX distribution, the relative changes in magnesium chelatase (EC 6.6.1.1) and ferrochelatase (EC 4.99.1.1) activities in the leaves of FA85 also indirectly reflected channeling of the metabolic flow into heme rather than Chl. A drastic loss in the transcripts for Pchlide oxidoreductase (EC 1.3.1.33) and Chl synthase (EC 2.5.1.62) accounted for a decrease in the metabolic flux and the re-direction of metabolites. The high-level accumulations of Chl precursors and traces of Chl in the leaves of FA85 suggest that a severe block between the steps from Pchlide to Chl formation during Chl biosynthesis is partially derived from the transcriptional downregulation of Pchlide oxidoreductase and Chl synthase.


Assuntos
Temperatura Baixa , Protoclorifilida/biossíntese , Protoporfirinas/biossíntese , Triticum/metabolismo , Cor , Ativação Enzimática , Ferroquelatase/genética , Ferroquelatase/metabolismo , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Liases/genética , Liases/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Fenótipo , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Protoclorifilida/genética , Protoporfirinas/genética , RNA de Plantas/genética , Especificidade da Espécie , Fatores de Tempo , Transcrição Gênica , Triticum/enzimologia , Triticum/genética
20.
PLoS Genet ; 5(3): e1000420, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19282985

RESUMO

For females, menarche is a most significant physiological event. Age at menarche (AAM) is a trait with high genetic determination and is associated with major complex diseases in women. However, specific genes for AAM variation are largely unknown. To identify genetic factors underlying AAM variation, a genome-wide association study (GWAS) examining about 380,000 SNPs was conducted in 477 Caucasian women. A follow-up replication study was performed to validate our major GWAS findings using two independent Caucasian cohorts with 854 siblings and 762 unrelated subjects, respectively, and one Chinese cohort of 1,387 unrelated subjects--all females. Our GWAS identified a novel gene, SPOCK (Sparc/Osteonectin, CWCV, and Kazal-like domains proteoglycan), which had seven SNPs associated with AAM with genome-wide false discovery rate (FDR) q<0.05. Six most significant SNPs of the gene were selected for validation in three independent replication cohorts. All of the six SNPs were replicated in at least one cohort. In particular, SNPs rs13357391 and rs1859345 were replicated both within and across different ethnic groups in all three cohorts, with p values of 5.09 x 10(-3) and 4.37 x 10(-3), respectively, in the Chinese cohort and combined p values (obtained by Fisher's method) of 5.19 x 10(-5) and 1.02 x 10(-4), respectively, in all three replication cohorts. Interestingly, SPOCK can inhibit activation of MMP-2 (matrix metalloproteinase-2), a key factor promoting endometrial menstrual breakdown and onset of menstrual bleeding. Our findings, together with the functional relevance, strongly supported that the SPOCK gene underlies variation of AAM.


Assuntos
Estudo de Associação Genômica Ampla , Menarca/genética , Proteoglicanas/genética , Adulto , Fatores Etários , Envelhecimento/genética , Feminino , Humanos , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , População Branca/genética
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