Biology subjects

Kashimoto, R.

Publications and source records attributed to Kashimoto, R..

4 recordsLinked to original sources

bioRxiv2024

Lignin isolated by microwave-assisted acid-catalyzed solvolysis induced cell death on mammalian tumor cells by modulating apoptotic pathways

Lignin, the most abundant renewable aromatic polymer, has been shown to suppress the growth of mammalian tumor cells. Despite being a textbook example, there is little information on the biological activity of lignin in relation to its molecular structure or the molecular mechanisms by which lignin suppresses tumor cells in mammalian species. Here, we prepared Microwave-assisted Acid-catalyzed Solvolysis Lignin (MASL) and assessed its effects on human and mouse tumor cells. Our data showed MASL significantly reduced viability of tumor cells by modulating apoptotic pathways. MASL treatment upregulated TNF-, Fas, and FasL expression levels, while suppressing anti-apoptotic NF-{kappa}B and mTOR pathways in tumor cells. In-vivo experiments were also performed using tumor-bearing mice to confirm the anti-tumor effects of MASL. An administration of MASL significantly suppressed tumor growth in mice in association with elevation of caspase 3 expression. These findings strongly suggest the potential usefulness of low molecular weight lignin as an effective therapeutic against malignancies.

cancer biology↗

bioRxiv2023

Anemonefish are better taxonomists than humans.

The symbiosis between giant sea anemones, photosynthetic algae of the family Symbiodiniaceae, and anemonefish is an iconic example of a mutualistic "menage a 3"1. Patterns of associations among 28 species of anemonefish and 10 species of giant sea anemone hosts are complex: Some anemonefish species are highly specialized to inhabit only one species of sea anemone (e.g., Amphiprion frenatus with Entacmaea quadricolor), whereas others are more generalist and can live in almost any host species (e.g., Amphiprion clarkii)1,2,3. Reasons for host preferences and the mechanisms involved are obscured, among other things, by the lack of resolution of giant sea anemone phylogeny. Recent molecular analyses have shown that giant sea anemones hosting anemonefish belong to three distinct clades: Entacmaea, Stichodactyla, and Heteractis4,5,6. Inside these clades, however, species delimitation has been impeded by morphological variability of the giant sea anemones and is poorly resolved with classical markers4,5. Here, we employed an extensive transcriptomic dataset from 55 sea anemones collected from southern Japan to build a robust phylogeny. With this dataset, we observed that the bubble-tip sea anemone E. quadricolor, currently considered to be a single species, can in fact be separated into at least four distinct cryptic lineages (A-D). Moreover, these lineages can be precisely distinguished by their association with anemonefish: A. frenatus is only found associated with lineage D, whereas A. clarkii lives in the other three lineages.

evolutionary biology↗

bioRxiv2022

The genetic basis for adaptation in giant sea anemones to their symbiosis with anemonefish and Symbiodiniaceae

Sea anemones in the order Anthozoa play an integral part in marine ecosystems by providing refuge and habitat for various organisms. Despite this, much of their molecular ecology remains elusive. Sea anemones can nurture numerous symbiotic relationships; the most iconic being the one between giant sea anemones and anemonefish. However, the genes and biological processes associated with this symbiosis in the sea anemones in unknown. Additionally, it is unclear how genes can mediate interactions between sea anemones, anemonefish, and symbionts from the algal family Symbiodiniaceae. Here we compared the gene expression profiles of tentacles from several cnidarians to uncover the genetic basis for adaptations in giant sea anemones to their symbiosis with anemonefish and Symbiodiniaceae. We found that tentacle transcriptomes of cnidarians are highly diverse, with closely related species having more similar expression patterns. However, despite an overall high correlation between gene expression and phylogeny, the giant sea anemones showed distinct expression patterns. The giant sea anemones had gene co-expression clusters enriched for processes involved in nutrient exchange and metabolism. These genes were not only differentially expressed, but also experienced evolutionary shifts in expression in giant sea anemones. Using a phylogenetic multilevel model, we found that Symbiodiniaceae and anemonefish significantly affect gene expression in giant sea anemone tentacles. By characterizing gene expression patterns, we identify genes and biological processes that provide evidence for the cross-talk between Symbiodiniaceae, anemonefish, and giant sea anemones. Our study demonstrates how integrated biological processes can lead to the evolution of a successful multi-organism interaction.

evolutionary biology↗

bioRxiv2021

Fluctuation of cellular differentiation in limb regeneration is regulated by Pde4b in urodele amphibians

Urodele amphibians, Pleurodeles waltl and Ambystoma mexicanum, have organ-level regeneration capability, such as limb regeneration. Multipotent cells are induced by an endogenous mechanism in amphibian limb regeneration. It is well known that dermal fibroblasts receive regenerative signals and turn into multipotent cells, called blastema cells. However, the induction mechanism of the blastema cells from matured dermal cells was unknown. We previously found that BMP2, FGF2, and FGF8 (B2FF) could play sufficient roles in blastema induction in urodele amphibians. Here, we show that B2FF treatment can induce dermis-derived cells that can participate in multiple cell lineage in limb regeneration. We first established a newt dermis-derived cell line and confirmed that B2FF treatment on the newt cells provided plasticity in cellular differentiation in limb regeneration. Interspecies comparative analysis clarified that Pde4b upregulation by B2FF specifically took place in the newt cells. Blocking PDE4B signaling by Rolipram suppressed dermis-to-cartilage transformation and the mosaic knockout animals showed consistent results. Our results are a valuable insight into how dermal fibroblasts acquire multipotency during the early phase of limb regeneration via an endogenous program in amphibian limb regeneration.

developmental biology↗