Next-generation sequencing of the human TRPV1 gene and the regulating co-players LTB4R and LTB4R2 based on a custom AmpliSeq (TM) panel
PLOS ONE
Authors: Kringel, Dario; Sisignano, Marco; Zinn, Sebastian; Loetsch, Joern
Abstract
Background Transient receptor potential cation channel subfamily V member 1 (TRPV1) are sensitive to heat, capsaicin, pungent chemicals and other noxious stimuli. They play important roles in the pain pathway where in concert with proinflammatory factors such as leukotrienes they mediate sensitization and hyperalgesia. TRPV1 is the target of several novel analgesics drugs under development and therefore, TRPV1 genetic variants might represent promising candidates for pharmacogenetic modulators of drug effects. Methods A next-generation sequencing (NGS) panel was created for the human TRPV1 gene and in addition, for the leukotriene receptors BLT1 and BLT2 recently described to modulate TRPV1 mediated sensitisation processes rendering the coding genes LTB4R and LTB4R2 important co-players in pharmacogenetic approaches involving TRPV1. The NGS workflow was based on a custom AmpliSeq (TM) panel and designed for sequencing of human genes on an Ion PGM (TM) Sequencer. A cohort of 80 healthy subjects of Western European descent was screened to evaluate and validate the detection of exomic sequences of the coding genes with 25 base pair exon padding. Results The amplicons covered approximately 97% of the target sequence. A median of 2.81 x 10(6) reads per run was obtained. This identified approximately 140 chromosome loci where nucleotides deviated from the reference sequence GRCh37 hg19 comprising the three genes TRPV1, LTB4R and LTB4R2. Correspondence between NGS and Sanger derived nucleotide sequences was 100%. Conclusions Results suggested that the NGS approach based on AmpliSeq (TM) libraries and Ion Personal Genome Machine (PGM) sequencing is a highly efficient mutation detection method. It is suitable for large-scale sequencing of TRPV1 and functionally related genes. The method adds a large amount of genetic information as a basis for complete analysis of TRPV1 ion channel genetics and its functional consequences.
Leukotriene Pathway Activation Associates with Poor Glycemic Control and with Cardiovascular Autonomic Neuropathy in Type 1 Diabetes
MEDIATORS OF INFLAMMATION
Authors: Santos-Bezerra, Daniele P.; Filgueiras, Luciano R.; Monteiro, Maria Beatriz; Admoni, Sharon N.; Perez, Ricardo, V; Cavaleiro, Ana M.; Machado, Cleide G.; Machado, Ubiratan F.; Passarelli, Marisa; Jancar, Sonia; Correa-Giannella, Maria Lucia
Abstract
Background and Aims. Since hyperglycemia promotes inflammation by different pathways and inflammation participates in the development of chronic diabetes complications, we investigated the association between the leukotriene (LT) pathway and microvascular diabetes complications. Methods and Results. Quantitative polymerase chain reaction was employed to quantify the expression of ALOX5 (encodes 5-lipoxygenase), LTB4R (encodes one of the LTB4 receptors), and MYD88 in peripheral blood mononuclear cells from 164 type 1 diabetes (T1D) individuals presenting or not diabetes kidney disease, retinopathy, peripheral neuropathy, and cardiovascular autonomic neuropathy (CAN); 26 nondiabetic subjects were included as controls. LTB4 plasmatic concentrations were also evaluated. The expression of LTB4R was significantly higher in T1D individuals than in controls. T1D individuals with microvascular complications presented lower MYD88 mRNA expression when compared to those without microvascular complications. Higher LTB4 concentrations were found in individuals with CAN versus without CAN. The observation of two distinct subgroups of T1D individuals in the correlation analyses motivated us to evaluate the characteristics of each one of these groups separately. The group presenting higher expression of ALOX5 and of LTB4R also presented higher values of HbA(1)C, of fructosamine, and of plasmatic LTB4. Conclusion. In the diabetes setting, the LT pathway is not only activated by hyperglycemia but is also modulated by the status of the autonomic nervous system.