Kozo Ohkusu-Tsukada

Cow-specific feature hepatic lesion, termed as eosinophilic proliferative phlebitis (EPP), has been mainly detected in Japanese black cattle and identified histologically eosinophilic infiltration and endothelial hyperplasia in portal areas. We previously proposed EPP as a food allergy from the pathological characteristics and a significant increase of serum immunoglobulin E specific to curly dock (Rumex crispus) in allergens testing, however, first report had regarded EPP an atypical type of bovine fascioliasis. In EPP lesions, eosinophilic infiltration was observed to the hypertrophic endothelium and not to the intrahepatic bile duct, and that was related to eotaxin-1 expression. In EPP, the mast cells increased as well as in fascioliasis, and the mast cells producing tryptase without chymase increased with interleukin-4 production. In this context, hyperplasia of periendothelium expressing proteinase-activated receptor-2 (PAR-2) and not angiotensin II was observed. Contrastably, in fascioliasis, unique mast cells producing neither tryptase nor chymase infiltrated, and the periendothelium expressed neither PAR-2 nor angiotensin II. Interestingly, EPP had not occurred liver injury with raised hepatic enzymes like fascioliasis, and suggested to a correlation with severe serum hypo-vitamin A. Overall, this study suggests that EPP is an allergic disease by main difference between adaptive immunity to allergens and innate immunity to parasites.

Genetic, transcriptional, and morphological differences have been reported in pancreatic ductal adenocarcinoma (PDAC) cases. We recently found that epithelial or mesenchymal features were enhanced in three-dimensional (3D) cultures compared to two-dimensional (2D) cultures. In this study, we examined the differences in the morphological and functional characteristics of eight PDAC cell lines in 2D and 3D cultures. Most PDAC cells showed similar pleomorphic morphologies in 2D culture. Under 3D culture, PDAC cells with high E-cadherin and low vimentin expression levels (epithelial) formed small round spheres encircled with flat lining cells, whereas those with high vimentin and low E-cadherin expression levels (mesenchymal) formed large grape-like spheres without lining cells and were highly proliferative. In 3D culture, gemcitabine was more effective for the spheres formed by PDAC cells with epithelial features, while abraxane was more effective on those with mesenchymal features. The expression levels of drug transporters were highest PDAC cells with high vimentin expression levels. These findings indicate that PDAC cells possess various levels of epithelial and mesenchymal characteristics. The 3D-culture method is useful for investigating the diversity of PDAC cell lines and may play important roles in the development of personalized early diagnostic methods and anticancer drugs for PDAC.

G protein-coupled receptors 41 and 43 were identified and characterized as free fatty acid receptors (FFAR) 3 and 2, respectively. FFAR2 and FFAR3 mediate short-chain fatty acids (SCFAs) as signalling molecules. The present study aimed to give molecular characterization of FFAR2 and FFAR3 in the domestic cat. High homology with that in other mammals was revealed by cDNA cloning of cat FFAR2 FFAR3. We analyzed the tissue distribution of cat FFAR2 and FFAR3 mRNA using quantitative polymerase chain reaction. The inhibition of intracellular cAMP concentrations was observed in cells transfected with cat FFAR2 or FFAR3 and treated with SCFAs. The activation of nuclear factor of activated T cells-luciferase reporter was only observed in cat FFAR2 transfected cells but not in FFAR3. Split luciferase assay (NanoLuc Binary Technology; NanoBiT) for FFAR2 or FFAR3 and Arrestin-3/β-arrestin-2 revealed acetate-/propionate-induced recruitment to cat FFAR2 or FFAR3 in CHO-K1 cells. Our results indicate that FFAR2 and FFAR3 are functional receptor proteins that are expressed in cat tissues and show differential distribution patterns.

Environmental factors and the major histocompatibility complex (MHC) are involved in the pathogenesis of atopic dermatitis (AD). However, MHC type (H2 haplotype) of AD model mice NC/Nga is poorly understood. Alloreactive CD8+ or CD4+ T cells in NC/Nga strongly responded to each antigen-presenting cells (A/J: H-2a, C57BL/6: H-2b, BALB/c: H-2d, or C3H/HeJ: H-2k), suggesting that NC/Nga has other H2 haplotype. Polymorphic microsatellite (CA)n repeats in TNF-α gene differ based on the H2 haplotype at present. NC/Nga’s (CA)n repeats (n = 19) were different from other examined strains, A/J (n = 14), BALB/c (n = 14), C3H/HeJ (n = 16), and C57BL/6 (n = 20). Using flow cytometry and genotyping, we demonstrated the NC/Nga H2 haplotype had a unique phenotype (Kd, I-Ak, and I-Ek) in which Dd and Ld lacked as protein despite sensitive mRNA detection. The loss of Dd and Ld was caused by forming a unique Ddm7/Ldm7-hybrid mutant (D/Ldm7). We propose to call this novel H2 haplotype the “H-2nc,” and provide the important information regarding the AD research using NC/Nga mice.