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Metamorphosis is the dramatic and irreversible reconstruction of animal bodies transitioning from the larval stage. Because of the significant impact of metamorphosis on animal life, its timing is strictly regulated. Invertebrate chordate ascidians are the closest living relatives of vertebrates. Ascidians exhibit metamorphosis that converts their swimming larvae into sessile adults. Ascidian metamorphosis is triggered by a mechanical stimulus generated when adhesive papillae adhere to a substrate. However, it is not well understood how the mechanical stimulus is generated and how ascidian larvae sense the stimulus. In this study, we addressed these issues by a combination of embryological, molecular, and genetic experiments in the model ascidian Ciona intestinalis Type A, also called Ciona robusta. We here showed that the epidermal neuronal network starting from the sensory neurons at the adhesive papillae is responsible for the sensing of adhesion. We also found that the transient receptor potential (TRP) channel PKD2 is involved in sensing the stimulus of adhesion. Our results provide a better understanding of the mechanisms underlying the regulation of the timing of ascidian metamorphosis. [ABSTRACT FROM AUTHOR]

Summary: Sesamum spp. (sesame) are known to accumulate a variety of lignans in a lineage‐specific manner. In cultivated sesame (Sesamum indicum), (+)‐sesamin, (+)‐sesamolin and (+)‐sesaminol triglucoside are the three major lignans found richly in the seeds. A recent study demonstrated that SiCYP92B14 is a pivotal enzyme that allocates the substrate (+)‐sesamin to two products, (+)‐sesamolin and (+)‐sesaminol, through multiple reaction schemes including oxidative rearrangement of α‐oxy‐substituted aryl groups (ORA). In contrast, it remains unclear whether (+)‐sesamin in wild sesame undergoes oxidation reactions as in S. indicum and how, if at all, the ratio of the co‐products is tailored at the molecular level. Here, we functionally characterised SrCYP92B14 as a SiCYP92B14 orthologue from a wild sesame, Sesamum radiatum, in which we revealed accumulation of the (+)‐sesaminol derivatives (+)‐sesangolin and its novel structural isomer (+)‐7´‐episesantalin. Intriguingly, SrCYP92B14 predominantly produced (+)‐sesaminol either through ORA or direct oxidation on the aromatic ring, while a relatively low but detectable level of (+)‐sesamolin was produced. Amino acid substitution analysis suggested that residues in the putative distal helix and the neighbouring heme propionate of CYP92B14 affect the ratios of its co‐products. These data collectively show that the bimodal oxidation mechanism of (+)‐sesamin might be widespread across Sesamum spp., and that CYP92B14 is likely to be a key enzyme in shaping the ratio of (+)‐sesaminol‐ and (+)‐sesamolin‐derived lignans from the biochemical and evolutionary perspectives. [ABSTRACT FROM AUTHOR]

Summary: Sesame (Sesamum indicum) seeds contain a large number of lignans, phenylpropanoid‐related plant specialized metabolites. (+)‐Sesamin and (+)‐sesamolin are major hydrophobic lignans, whereas (+)‐sesaminol primarily accumulates as a water‐soluble sesaminol triglucoside (STG) with a sugar chain branched via β1→2 and β1→6‐O‐glucosidic linkages [i.e. (+)‐sesaminol 2‐O‐β‐d‐glucosyl‐(1→2)‐O‐β‐d‐glucoside‐(1→6)‐O‐β‐d‐glucoside]. We previously reported that the 2‐O‐glucosylation of (+)‐sesaminol aglycon and β1→6‐O‐glucosylation of (+)‐sesaminol 2‐O‐β‐d‐glucoside (SMG) are mediated by UDP‐sugar‐dependent glucosyltransferases (UGT), UGT71A9 and UGT94D1, respectively. Here we identified a distinct UGT, UGT94AG1, that specifically catalyzes the β1→2‐O‐glucosylation of SMG and (+)‐sesaminol 2‐O‐β‐d‐glucosyl‐(1→6)‐O‐β‐d‐glucoside [termed SDG(β1→6)]. UGT94AG1 was phylogenetically related to glycoside‐specific glycosyltransferases (GGTs) and co‐ordinately expressed with UGT71A9 and UGT94D1 in the seeds. The role of UGT94AG1 in STG biosynthesis was further confirmed by identification of a STG‐deficient sesame mutant that predominantly accumulates SDG(β1→6) due to a destructive insertion in the coding sequence of UGT94AG1. We also identified UGT94AA2 as an alternative UGT potentially involved in sugar–sugar β1→6‐O‐glucosylation, in addition to UGT94D1, during STG biosynthesis. Yeast two‐hybrid assays showed that UGT71A9, UGT94AG1, and UGT94AA2 were found to interact with a membrane‐associated P450 enzyme, CYP81Q1 (piperitol/sesamin synthase), suggesting that these UGTs are components of a membrane‐bound metabolon for STG biosynthesis. A comparison of kinetic parameters of these UGTs further suggested that the main β‐O‐glucosylation sequence of STG biosynthesis is β1→2‐O‐glucosylation of SMG by UGT94AG1 followed by UGT94AA2‐mediated β1→6‐O‐glucosylation. These findings together establish the complete biosynthetic pathway of STG and shed light on the evolvability of regio‐selectivity of sequential glucosylations catalyzed by GGTs. Significance Statement: Sesaminol triglucoside (STG) of sesame seeds has unique bioactivities with potential health benefits, yet the STG biosynthesis pathway remains to be fully established. This study has identified the missing enzyme in STG biosynthesis that catalyzes β1→2‐O‐glucosylation, a regioselective sequential glycosylation of sesame lignan biosynthesis. [ABSTRACT FROM AUTHOR]

Stable breast cancer cell ( BCC) lines are valuable tools for the identification of breast cancer stem cell ( BCSC) phenotypes that develop in response to several stimuli as well as for studying the basic mechanisms associated with the initiation and maintenance of BCSCs. However, the characteristics of individual, BCC-derived BCSCs varies and these cells show distinct phenotypes depending on the different BCSC markers used for their isolation. Aldehyde dehydrogenase ( ALDH) activity is just such a recognized biomarker of BCSCs with a CD44+/ CD24− phenotype. We isolated BCSCs with high ALDH activity ( CD44+/ CD24−/Aldefluorpos) from a primary culture of human breast cancer tissue and observed that the cells had stem cell properties compared to BCSCs with no ALDH activity ( CD44+/ CD24−/Aldefluorneg). Moreover, we found Aldefluorpos BCSCs had a greater hypoxic response and subsequent induction of HIF-1α expression compared to the Aldefluorneg BCSCs. We also found that knocking down HIF-1α, but not HIF-2α, in Aldefluorpos BCSCs led to a significant reduction of the stem cell properties through a decrease in the mRNA levels of genes associated with the epithelial-mesenchymal transition. Indeed, HIF-1α overexpression in Aldefluorneg BCSCs led to Slug and Snail mRNA increase and the associated repression of E-cadherin and increase in Vimentin. Of note, prolonged hypoxic stimulation promoted the phenotypic changes of Aldefluorneg BCSCs including ALDH activity, tumorigenesis and metastasis, suggesting that hypoxia in the tumor environment may influence BCSC fate and breast cancer clinical outcomes. [ABSTRACT FROM AUTHOR]

The expression of estrogen receptor is the key in most breast cancers (BC) and binding of estrogen receptor to the genome correlates to Forkhead protein (FOXA1) expression. We herein assessed the correlation between the cancer stem cell (CSC) population and FOXA1 expression in luminal BC. We established luminal BC cells derived from metastatic pleural effusion and analyzed the potency of CSC and related factors with established luminal BC cell lines. We also confirmed that mammosphere cultures have an increased aldehyde dehydrogenase-positive population, which is one of the CSC markers, compared with adherent culture cells. Using a quantitative PCR analysis, we found that mammosphere forming cells showed a higher expression of FOXA1 and stemness-related genes compared with adherent culture cells. Furthermore, the growth activity and colony-forming activity of 4-hydroxytamoxifen-treated BC cells were inhibited in a mammosphere assay. Interestingly, 4-hydroxytamoxifen-resistant cells had significantly increased FOXA1 gene expression levels. Finally, we established short hairpin RNA of FOXA1 (shFOXA1) MCF-7 cells and investigated the relationship between self-renewal potential and FOXA1 expression. As a result, we found no significant difference in the number of mammospheres but decreased colony formation in shFOXA1 MCF-7 cells compared with control. These results suggest that the expression of FOXA1 appears to be involved in the proliferation of immature BC cells rather than the induction of stemness-related genes and self-renewal potency of CSCs. [ABSTRACT FROM AUTHOR]

The RSA scheme is considered as one of the most promising as a digital signature, i.e., the signature for document for digital information. However, the method has a problem in that the processing speed is slow. A method by high-speed hash function is proposed as a solution to this problem, but the improvement is not remarkable for brief documents. To solve this problem, this paper proposes a new high-speed digital signature scheme based on a congruent polynomial of lower degree. In this scheme, large prime numbers p and q are used as the secret information and n = p²q is used as the public information. A random is used in the generation of the signature, and an equality is used in the verification. It is shown that the security of the proposed scheme is of the same order of the difficulty of the prime factorization of n. The processing speed ad transfer/retained information of the proposed scheme are evaluated, indicating that the processing speed for a brief document is more than 100 times the RSA scheme, and the method requires larger secret information to be retained than in RSA scheme. [ABSTRACT FROM AUTHOR]