Biology subjects

Tanno, T.

Publications and source records attributed to Tanno, T..

3 recordsLinked to original sources

bioRxiv2024

Interresponse time and run length shaping by discrete-trial percentile schedule incorporating fixed consecutive number procedure

The effect of incorporating a fixed consecutive number (FCN) procedure in interresponse time (IRT) shaping using a discrete-trial percentile schedule was examined. Eight pigeons were used. On each trial, pigeons were required to peck the IRT start key and then the IRT end key. Reinforcers were presented according to the percentile schedule based on the time interval (IRT) or the cumulative response count to the IRT start key during those two key pecks. Multiple responses to the IRT start key were allowed only in the condition incorporating the FCN procedure. Results showed that incorporating the FCN procedure improved the success of IRT shaping from 1/8 to 7/8 of the pigeons. The procedure developed in this study provides an ideal baseline for studying response shaping with IRT as the dependent variable.

animal behavior and cognition↗

bioRxiv2019

Exosome-mediated crosstalk stimulated by liver fluke granulin promotes a microenvironment conducive to cholangiocarcinoma

Crosstalk between malignant and neighboring cells contributes to tumor growth. In East Asia, infection with fish-borne liver flukes is a major risk factor for cholangiocarcinoma (CCA). The parasite secretes a growth factor termed liver fluke granulin (Ov-GRN-1), a homologue of the human progranulin (huPGRN), which contributes significantly to biliary tract fibrosis and morbidity during infection. Here, exosome-mediated transfer of mRNAs from the human cholangiocyte cell line (H69) was investigated following exposure to Ov-GRN-1, to naive recipient H69 cells. To minimize the influence of endogenous huPGRN, the gene encoding huPGRN was inactivated using CRISPR/Cas9-based gene knock-out. Several huPGRN-depleted cell lines, termed {Delta}huPGRN-H69, were established. These lines exhibited >80% reductions in levels of huPGRN transcripts and protein, both in gene-edited cells and within exosomes released by these cells. Profiles of exosomal RNAs (exRNA) from {Delta}huPGRN-H69 for CCA-associated characteristics revealed a paucity of transcripts for estrogen- and Wnt-signaling pathways, peptidase inhibitors and tyrosine phosphatase related to cellular processes including oncogenic transformation. Several CCA-specific mRNAs including MAPK/AKT pathway members were induced by exposure to Ov-GRN-1. By comparison, estrogen, Wnt/PI3K and TGF signaling and other CCA pathway mRNAs were upregulated in wild type H69 exposed to Ov-GRN-1. Of these, CCA-associated exRNAs modified the CCA microenvironment in naive recipient cells co-cultured with exosomes from {Delta}huPGRN-H69 exposed to Ov-GRN-1, and induced translation of MAPK phosphorylation related-protein in naive recipient cells comparing with control recipient cells. Exosome-mediated crosstalk in response to liver fluke granulin promoted a CCA-specific program through MAPK pathway which, in turn, established a CCA-conducive disposition.

molecular biology↗

bioRxiv2018

Functional genomics and programmed genome editing of omega-1 of the blood fluke Schistosoma mansoni

CRISPR/Cas9 based genome editing has yet been reported in parasitic or indeed any species of the phylum Platyhelminthes. We tested this approach by targeting omega-1 ({omega}1) of Schistosoma mansoni as a proof of principle. This secreted ribonuclease is crucial for Th2 priming and granuloma formation, providing informative immuno-pathological readouts for programmed genome editing. Schistosome eggs were either exposed to Cas9 complexed with a synthetic guide RNA (sgRNA) complementary to exon 6 of {omega}1 by electroporation or transduced with pseudotyped lentivirus encoding Cas9 and the sgRNA. Some eggs were also transduced with a single stranded oligodeoxynucleotide donor transgene that encoded six stop codons, flanked by 50 nt-long 5-and 3-microhomology arms matching the predicted Cas9-catalyzed double stranded break (DSB) within {omega}1. CRISPResso analysis of amplicons spanning the DSB revealed [~]4.5% of the reads were mutated by insertions, deletions and/or substitutions, with an efficiency for homology directed repair of 0.19% insertion of the donor transgene. Transcripts encoding {omega}1 were reduced >80% and lysates of {omega}1-edited eggs displayed diminished ribonuclease activity indicative that programmed editing mutated the {omega}1 gene. Whereas lysates of wild type eggs polarized Th2 cytokine responses including IL-4 and IL-5 in human macrophage/T cell co-cultures, diminished levels of the cytokines followed the exposure to lysates of {omega}1-mutated schistosome eggs. Following injection of schistosome eggs into the tail vein of mice, the volume of pulmonary granulomas surrounding {omega}1-mutated eggs was 18-fold smaller than wild type eggs. Programmed genome editing was active in schistosomes, Cas9-catalyzed chromosomal breakage was repaired by homology directed repair and/or non-homologous end joining, and mutation of {omega}1 impeded the capacity of schistosome eggs both to drive Th2 polarization and to provoke formation of pulmonary circumoval granulomas. Knock-out of {omega}1 and the impaired immunological phenotype showcase the novel application of programmed gene editing in and functional genomics for schistosomes.

molecular biology↗