Two type III polyketide synthases from Polygonum cuspidatum: gene structure, evolutionary route and metabolites

Lan-Qing Ma,Yan-Wu Guo,Hui-Li Guo,Xing Li,Li-Li Huang,Bo-Ning Zhang,Xiao-Bin Pang,Ben-Ye Liu,Hong Wang 한국식물생명공학회 2013 Plant biotechnology reports Vol.7 No.3

In our recent work (Ma et al., in Planta229(3):457–469, 2009a and 229(4):1077–1086, 2009b),two three-intron type III PKS genes, PcPKS1 and PcPKS2,were isolated from Polygonum cuspidatum Sieb. et Zucc. Phylogenetic and functional analyses revealed PcPKS1 is athree-intron chalcone synthase (CHS) gene, and PcPKS2 isfound to be a three-intron benzalacetone synthase (BAS)gene. The regular CHS encoded by a single intron genehave not been isolated and characterized from P. cuspidatum. In this work a further CHS with one intron (PcPKS3)and a stilbene synthase (STS) gene with three-intron(PcPKS5) were isolated and characterized by functionaland phylogenetic analyses. In comparison with PcPKS1, abifunctional enzyme with both CHS and BAS activity, theenzymatic product of recombinant PcPKS3 was naringenin,bis-noryangonin (BNY) and 4-coumaroyltriacetic acidlactone (CTAL) occurred as side products. The PcPKS5synthesized resveratrol and a trace amount of naringeninfrom p-coumaroyl-CoA. To our knowledge, PcPKS5 is thefirst reported three-intron STS gene in flowering plants. Inthis work, we speculated that this involved a possibleevolutionary route of plant-specific type III PKS superfamilyin P. cuspidatum.

Insulin receptors regulate the fecundity of Nilaparvata lugens (Stål) (Hemiptera: Delphacidae)

Liu Yong-Kang,Luo Yu-Jia,Deng Ying-Mei,Li Yan,Pang Xiao-Qing,Xu Cai-Di,Wang Shi-Gui,Tang Bin 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.4

Two InR (insulin receptor) genes have been identified in the Nilaparvata lugens. In this study, we used RNA interference (RNAi) to investigate the role of InR genes in the fecundity of N. lugens. The expression of NLInR1 and NLInR2 genes was simultaneously silenced with mixture of dsInR1 and dsInR2 (dsInRs) injection. Our results showed that larvae RNAi against both NLInR1 and NLInR2 reduced the number of eggs laid by N. lugens and some eggs as well as ovaries were abnormal. In addition, the relative expression of Vg (vitellogenin) and VgR (vitellogenin receptor) was significantly reduced on the 4th and 6th days after insects treated with larvae RNAi reached the adult stage. We also determined the relative expression levels of insulin/insulin-like signaling (IIS) related genes in RNAi-treated larvae and found that the expression levels of Chico (homologous receptor substrate), Akt (protein kinase B), PI3K (phosphoinositide 3-kinase), and PTEN (phosphatase and tensin homolog) genes decreased whereas FOXO (forkhead box O) and GSK3 (glycogen synthase kinase-3) levels increased on the 4th and 6th days after insects reached the adult stage. These results indicate that silencing of NLInR1 and NLInR2 reduces the fecundity of N. lugens through the IIS pathway.

Increased Serotonin Signaling Contributes to the Warburg Effect in Pancreatic Tumor Cells Under Metabolic Stress and Promotes Growth of Pancreatic Tumors in Mice

Jiang, Shu-Heng,Li, Jun,Dong, Fang-Yuan,Yang, Jian-Yu,Liu, De-Jun,Yang, Xiao-Mei,Wang, Ya-Hui,Yang, Min-Wei,Fu, Xue-Liang,Zhang, Xiao-Xin,Li, Qing,Pang, Xiu-Feng,Huo, Yan-Miao,Li, Jiao,Zhang, Jun-Feng Elsevier 2017 Gastroenterology Vol.153 No.1

<P><B>Background & Aims</B></P> <P>Desmoplasia and poor vascularity cause severe metabolic stress in pancreatic ductal adenocarcinomas (PDACs). Serotonin (5-HT) is a neuromodulator with neurotransmitter and neuroendocrine functions that contributes to tumorigenesis. We investigated the role of 5-HT signaling in the growth of pancreatic tumors.</P> <P><B>Methods</B></P> <P>We measured the levels of proteins that regulate 5-HT synthesis, packaging, and degradation in pancreata from Kras<SUP>G12D/+</SUP>/Trp53<SUP>R172H/+</SUP>/Pdx1-Cre (KPC) mice, which develop pancreatic tumors, as well as in PDAC cell lines and a tissue microarray containing 81 human PDAC samples. We also analyzed expression levels of proteins involved in 5-HT synthesis and degradation by immunohistochemical analysis of a tissue microarray containing 311 PDAC specimens, and associated expression levels with patient survival times. 5-HT level in 14 matched PDAC tumor and non-tumor tissues were analyzed by ELISA. PDAC cell lines were incubated with 5-HT and cell survival and apoptosis were measured. We analyzed expression of the 5-HT receptor HTR2B in PDAC cells and effects of receptor agonists and antagonists, as well as HTR2B knockdown with small hairpin RNAs. We determined the effects of 5-HT stimulation on gene expression profiles of BxPC-3 cells. Regulation of glycolysis by 5-HT signaling via HTR2B was assessed by immunofluorescence and immunoprecipitation analyses, as well as by determination of the extracellular acid ratio, glucose consumption, and lactate production. Primary PDACs, with or without exposure to SB204741 (a selective antagonist of HTR2B), were grown as xenograft tumors in mice, and SB204741 was administered to tumor-bearing KPC mice; tumor growth and metabolism were measured by imaging analyses.</P> <P><B>Results</B></P> <P>In immunohistochemical analysis of a tissue microarray of PDAC specimens, increased levels of TPH1 and decreased level of MAOA, which regulate 5-HT synthesis and degradation, correlated with stage and size of PDACs and shorter patient survival time. We found levels of 5-HT to be increased in human PDAC tissues compared with non-tumor pancreatic tissues, and PDAC cell lines compared with non-transformed pancreatic cells. Incubation of PDAC cell lines with 5-HT increased proliferation and prevented apoptosis. Agonists of HTR2B, but not other 5-HT receptors, promoted proliferation and prevented apoptosis of PDAC cells. Knockdown of HTR2B in PDAC cells, or incubation of cells with HTR2B inhibitors, reduced their growth as xenograft tumors in mice. We observed a correlation between 5-HT and glycolytic flux in PDAC cells; levels of metabolic enzymes involved in glycolysis, the phosphate pentose pathway, and hexosamine biosynthesis pathway increased significantly in PDAC cells following 5-HT stimulation. 5-HT stimulation led to formation of the HTR2B–LYN–p85 complex, which increased PI3K–Akt–mTOR signaling and the Warburg effect by increasing protein levels of MYC and HIF1A. Administration of SB204741 to KPC mice slowed growth and metabolism of established pancreatic tumors and prolonged survival of the mice.</P> <P><B>Conclusions</B></P> <P>Human PDACs have increased levels of 5-HT, and PDAC cells increase expression of its receptor, HTR2B. These increases allow for tumor glycolysis under metabolic stress and promote growth of pancreatic tumors and PDAC xenograft tumors in mice.</P>

Two type III polyketide synthases from Polygonum cuspidatum: gene structure, evolutionary route and metabolites

Guo, Yan-Wu,Guo, Hui-Li,Li, Xing,Huang, Li-Li,Zhang, Bo-Ning,Pang, Xiao-Bin,Liu, Ben-Ye,Ma, Lan-Qing,Wang, Hong 한국식물생명공학회 2013 Plant biotechnology reports Vol.7 No.3

In our recent work (Ma et al., in Planta 229(3):457-469, 2009a and 229(4):1077-1086, 2009b), two three-intron type III PKS genes, PcPKS1 and PcPKS2, were isolated from Polygonum cuspidatum Sieb. et Zucc. Phylogenetic and functional analyses revealed PcPKS1 is a three-intron chalcone synthase (CHS) gene, and PcPKS2 is found to be a three-intron benzalacetone synthase (BAS) gene. The regular CHS encoded by a single intron gene have not been isolated and characterized from P. cuspidatum. In this work a further CHS with one intron (PcPKS3) and a stilbene synthase (STS) gene with three-intron (PcPKS5) were isolated and characterized by functional and phylogenetic analyses. In comparison with PcPKS1, a bifunctional enzyme with both CHS and BAS activity, the enzymatic product of recombinant PcPKS3 was naringenin, bis-noryangonin (BNY) and 4-coumaroyltriacetic acid lactone (CTAL) occurred as side products. The PcPKS5 synthesized resveratrol and a trace amount of naringenin from p-coumaroyl-CoA. To our knowledge, PcPKS5 is the first reported three-intron STS gene in flowering plants. In this work, we speculated that this involved a possible evolutionary route of plant-specific type III PKS superfamily in P. cuspidatum.