Avian retroviral cardiomyopathy induced by infectious molecular clones of avian leukosis viruses (fowl glioma-inducing virus variants).

We previously described cardiomyocyte abnormality caused by Km_5666 strain, a variant of fowl glioma-inducing virus (FGV) prototype, which is an avian leukosis virus (ALV). However, the cardiac involvement appeared to be eradicated from the flock after a few years. An epidemiological survey from 2017 to 2020 was performed to elucidate the current prevalence of the cardiopathogenic strains in this flock. Four of the 71 bantams pathologically examined showed both glioma and cardiomyocyte abnormality, from which three ALV strains were detected. DNA sequencing revealed that several different ALV strains coexisted in each bantam and that the conserved Km_5666 virus fluid also contained at least two different ALV strains. We generated three infectious molecular clones from these samples, named KmN_77_clone_A, KmN_77_clone_B, and Km_5666_clone. The envSU of KmN_77_clone_A shared high sequence identity with that of Km_5666 (94.1%). In contrast, the envSU of KmN_77_clone_B showed >99.2% nucleotide similarity with that of an FGV variant without cardiopathogenicity. Furthermore, Km_5666_clone experimentally reproduced both gliomas and cardiomyocyte abnormality in chickens. From these results, it is suggested that the pathogenic determinant of cardiomyocyte abnormality is located in envSU similar to that of Km_5666. The cloning technique described here is beneficial for evaluating the viral pathogenicity in cases where affected birds are coinfected with several different ALV strains.

Radical Caging Strategy for Cholinergic Optopharmacology.

Photo-caged methodologies have been indispensable for elucidating the functional mechanisms of pharmacologically active molecules at the cellular level. A photo-triggered removable unit enables control of the photo-induced expression of pharmacologically active molecular function, resulting in a rapid increase in the concentration of the bioactive compound near the target cell. However, caging the target bioactive compound generally requires specific heteroatom-based functional groups, limiting the types of molecular structures that can be caged. We have developed an unprecedented methodology for caging/uncaging on carbon atoms using a unit with a photo-cleavable carbon-boron bond. The caging/uncaging process requires installation of the CH2-B group on the nitrogen atom that formally assembles an N-methyl group protected with a photoremovable unit. N-Methylation proceeds by photoirradiation via carbon-centered radical generation. Using this radical caging strategy to cage previously uncageable bioactive molecules, we have photocaged molecules with no general labeling sites, including acetylcholine, an endogenous neurotransmitter. Caged acetylcholine provides an unconventional tool for optopharmacology to clarify neuronal mechanisms on the basis of photo-regulating acetylcholine localization. We demonstrated the utility of this probe by monitoring uncaging in HEK cells expressing a biosensor to detect ACh on the cell surface, as well as Ca2+ imaging in Drosophila brain cells (ex vivo).

Small-Molecule-Mediated Suppression of BMP Signaling by Selective Inhibition of BMP1-Dependent Chordin Cleavage.

BMP signaling is critical for many biological processes. Therefore, small molecules that modulate BMP signaling are useful for elucidating the function of BMP signaling and treating BMP signaling-related diseases. Here, we performed a phenotypic screening in zebrafish to examine the in vivo effects of N-substituted-2-amino-benzoic acid analogs NPL1010 and NPL3008 and found that they affect BMP signaling-dependent dorsal-ventral (D-V) patterning and bone formation in zebrafish embryos. Furthermore, NPL1010 and NPL3008 suppressed BMP signaling upstream of BMP receptors. BMP1 cleaves Chordin, an antagonist of BMP, and negatively regulates BMP signaling. Docking simulations demonstrated that NPL1010 and NPL3008 bind BMP1. We found that NPL1010 and NPL3008 partially rescued the disruptions in the D-V phenotype caused by bmp1 overexpression and selectively inhibited BMP1-dependent Chordin cleavage. Therefore, NPL1010 and NPL3008 are potentially valuable inhibitors of BMP signaling that act through selective inhibition of Chordin cleavage.

Reductive umpolung for asymmetric synthesis of chiral α-allenic alcohols.

In this communication, we report a chiral copper/NHC-catalyzed reaction between aromatic aldehydes and propargylic phosphates using a silylboronate, providing enantioenriched chiral α-allenic alcohols with complete regioselectivity and moderate to high enantioselectivity. The reaction pathway involves the catalytic formation of a nucleophilic α-alkoxylalkylcopper(i) species from aldehydes followed by its SN2' type substitution reaction with propargylic phosphates.

Neuropathogenicity of newly isolated avian leukosis viruses from chickens with osteopetrosis and mesenchymal neoplasms.

ABSTRACT The prototype fowl glioma-inducing virus (FGVp) causes fowl glioma and cerebellar hypoplasia in chickens. In this study, we investigated whether a strain of avian leukosis virus (ALV), associated with avian osteopetrosis and mesenchymal neoplasms, is able to induce fowl glioma. We encountered avian osteopetrosis and mesenchymal neoplasms, including myxosarcoma and rhabdomyosarcoma, in Japanese native chickens used for both egg-laying and meat production. These birds were also affected by non-suppurative encephalitis and glioma in their brains. Four ALV strains (GifN_001, GifN_002, GifN_004, GifN_005) were isolated, and a phylogenic analysis of envSU showed that these isolates were classified into different clusters from FGVp and the variants previously reported. Whereas the envSU shared a high identity (94.7%) with that of Rous sarcoma virus (strain Schmidt-Ruppin B) (RSV-SRB), the identity between envTM of GifN_001 and that of FGVp was high (94.5%), indicating that GifN_strains may emerge by recombination between FGVp and other exogenous ALVs. Specific-pathogen-free chickens inoculated in ovo with GifN_001 revealed fowl glioma and cerebellar hypoplasia. These results suggest that the newly isolated strains have acquired neuropathogenicity to chickens.

Helical mechanoclinic deformation of main-chain chiral smectic elastomers.

The helical mechanoclinic deformation of a main-chain chiral smectic elastomer, which is prepared by a crosslinking reaction under twist deformation, is investigated. The twist deformation induces a layer tilt angle that depends on the handedness of twist. The layer tilt angle in the right-handedly twisted elastomer, of which the handedness is consistent with that of the helix in the SmC* phase of the non-crosslinked backbone polymer, is estimated to be up to 16° at room temperature, although that in the left-handedly twisted elastomer is less than several degrees. The experiments provide evidence of chiral coupling between tilt and twist for helical mechanoclinic deformation in the chiral smectic system.