药用寄生植物菟丝子属,列当属和无根藤属氨基酸的分析

本文测定了菟丝子属、列当属和无根藤属某些种的种子和植株氨基酸的种类组成和含量。结果表明,3个属种子和植株氨基酸均在15种以上,且含量丰富,特别是必需氨基酸的含量较高。文中讨论了氨基酸的药用和在种子鉴定与化学分类上的作用,探讨了开发应用的前景。     

Design,synthesis and anti-malarial activities of synthetic analogs of biselyngbyolide B,a Ca2+ pump inhibitor from marine cyanobacteria

Biselyngbyaside, an 18-membered macrolide glycoside from marine cyanobacteria, and its derivatives are known to be sarco/endoplasmic reticulum Ca²⁺ ATPase (SERCA) inhibitors. Recently, a SERCA orthologue of the malaria parasite, PfATP6, has attracted attention as a malarial drug target. To provide a novel drug lead, we designed new synthetic analogs of biselyngbyolide B, the aglycone of biselyngbyaside, based on the co-crystal structure of SERCA with biselyngbyolide B, and synthesized them using the established synthetic route for biselyngbyolide B. Their biological activities against malarial parasites were evaluated.     

The yeast mitochondrial permeability transition is regulated by reactive oxygen species,endogenous Ca2+ and Cpr3, mediating cell death

We investigated the properties of the permeability transition pore (PTP) in Saccharomyces cerevisiae in agar-embedded mitochondria (AEM) and agar-embedded cells (AEC) and its role in yeast death. In AEM, ethanol-induced pore opening, as indicated by the release of calcein and mitochondrial membrane depolarization, can be inhibited by CsA, by Cpr3 deficiency, and by the antioxidant glutathione. Notably, the pore opening is inhibited, when mitochondria are preloaded by EGTA or Fluo3 to chelate matrix Ca²⁺, or are pretreated with 4-Br A23187 to extract matrix Ca²⁺, prior to agar-embedding, or when pore opening is induced in the presence of EGTA; opened pores are re-closed by sequential treatment with CsA, 4-Br A23187 plus EGTA and NADH, indicating endogenous matrix Ca²⁺ involvement. CsA also inhibits the pore opening with low conductance triggered by exogenous Ca²⁺ transport with ETH129. In AEC, the treatment of tert-butylhydroperoxide, a pro-oxidant that triggers transient pore opening in high conductance in AEM, induces yeast death, which is also dependent on CsA and Cpr3. Furthermore, AEMs from mutants lacking three ADP/ATP carrier (AAC) isoforms and with defective ATP synthase dimerization exhibit high and low conductance pore openings with CsA sensitivity, respectively. Collectively, these data show that the yeast PTP is regulated by Cpr3, endogenous matrix Ca²⁺, and reactive oxygen species, and that it is involved in yeast death; furthermore, ATP synthase dimers play a key role in CsA-sensitive pore formation, while AACs are dispensable.     

Elucidation of the speciation history of three sister species of crown-of-thorns starfish (Acanthaster spp.) based on genomic analysis

The crown-of-thorns starfish (COTS) is a coral predator that is widely distributed in Indo-Pacific Oceans. A previous phylogenetic study using partial mitochondrial sequences suggested that COTS had diverged into four distinct species, but a nuclear genome-based analysis to confirm this was not conducted. To address this, COTS species nuclear genome sequences were analysed here, sequencing Northern Indian Ocean (NIO) and Red Sea (RS) species genomes for the first time, followed by a comparative analysis with the Pacific Ocean (PO) species. Phylogenetic analysis and ADMIXTURE analysis revealed clear divergences between the three COTS species. Furthermore, within the PO species, the phylogenetic position of the Hawaiian sample was further away from the other Pacific-derived samples than expected based on the mitochondrial data, suggesting that it may be a PO subspecies. The pairwise sequentially Markovian coalescent model showed that the trajectories of the population size diverged by region during the Mid-Pleistocene transition when the sea-level was dramatically decreased, strongly suggesting that the three COTS species experienced allopatric speciation. Analysis of the orthologues indicated that there were remarkable genes with species-specific positive selection in the genomes of the PO and RS species, which suggested that there may be local adaptations in the COTS species.     

Basolateral protein Scribble binds phosphatase PP1 to establish a signaling network maintaining apicobasal polarity

Scribble, a member of the LAP protein family, contributes to the apicobasal polarity (ABP) of epithelial cells. The LAP-unique region of these proteins, which is essential and sufficient for ABP, includes a conserved Leucine-Rich Repeat (LRR) domain. The major binding partners of this region that could regulate ABP remain unknown. Here, using proteomics, native gel electrophoresis, and site-directed mutagenesis, we show that the concave surface of LRR domain in Scribble participates in three types of mutually exclusive interactions—(i) homodimerization, serving as an auto-inhibitory mechanism; (ii) interactions with a diverse set of polarity proteins, such as Llgl1, Llgl2, EPB41L2, and EPB41L5, which produce distinct multiprotein complexes; and (iii) a direct interaction with the protein phosphatase, PP1. Analogy with the complex between PP1 and LRR domain of SDS22, a well-studied PP1 regulator, suggests that the Scibble-PP1 complex stores a latent form of PP1 in the basolateral cell cortex. Such organization may generate a dynamic signaling network wherein PP1 could be dispatched from the complex with Scribble to particular protein ligands, achieving fast dephosphorylation kinetics.     

Comparison of rNIS and hNIS as reporter genes for noninvasive imaging of bone mesenchymal stem cells transplanted into infarcted rat myocardium

The purpose of this study was to investigate and compare the feasibility of rat sodium iodide symporter (rNIS) and human sodium iodide symporter (hNIS) as reporter genes for noninvasive monitoring of rat bone marrow mesenchymal stem cells (rBMSCs) transplanted into infarcted rat myocardium. rBMSCs were isolated from rat bone marrow. Adenovirus (Ad) was reconstructed to contain rNIS-enhanced green fluorescent protein (eGFP) or hNIS-eGFP. The transfection efficiency of Ad/eGFP/rNIS and Ad/eGFP/hNIS to rBMSCs was measured by real-time polymerase chain reaction, flow cytometry, Western blot, and immunofluorescence staining. The transfected rBMSCs were transplanted into infarcted rat myocardium followed by a single-photon emission computed tomography (SPECT) study with (99m)Tc-pertechnetate as the radiotracer and by autoradiography. The isolated rBMSCs were CD29, CD44, and CD90 positive and CD34, CD45, and CD11b negative. The expression of rNIS and hNIS in the transfected rBMSCs at both gene and protein levels was obviously higher than that without transfection. The myocardium of rats transplanted with transfected rBMSCs could be visualized by SPECT owing to the accumulation of (99m)Tc-pertechnetate in rBMSCs mediated by exogenous NIS genes. The accumulation of (99m)Tc-pertechnetate in myocardium mediated by rNIS was higher than that by hNIS, which was also confirmed by autoradiography. Both rNIS and hNIS are useful reporter genes to monitor BMSCs transplanted into infarcted myocardium in vivo with rNIS being superior to hNIS as the reporter gene.     

LIP19, a basic region leucine zipper protein, is a Fos-like molecular switch in the cold signaling of rice plants

The rice low-temperature-induced lip19 gene encodes a 148-amino-acid basic region/leucine zipper (bZIP) protein, termed LIP19. In this study we characterized LIP19 and showed that it lacks the usual ability of bZIP proteins to homodimerize and to bind DNA, as does the Fos protein in mammals. Using a yeast two-hybrid system, the cDNA clones whose products interact with LIP19 were screened. This search revealed a clone termed OsOBF1 (Oryza sativa OBF1) that encodes a new bZIP protein (OsOBF1). This protein forms a homodimer and binds to the hexamer motif sequence (5'-ACGTCA-3'). The protein-protein interaction in homo- and hetero-combinations between LIP19 and OsOBF1 was confirmed in vitro and in planta. LIP19 and OsOBF1 most likely interact with each other more strongly than OsOBF1 interacts with itself, and the resulting heterodimer binds to the C/G hybrid sequence but not to the hexamer sequence. Whereas the expression patterns of lip19 and OsOBF1 in response to low temperatures were totally opposite, the locations of their expression were almost identical. Based upon the presented data, we propose a model describing the low-temperature signal switching mediated by LIP19 in rice.     

Association of lecithin-cholesterol acyltransferase activity and low-density lipoprotein heterogeneity with atherosclerotic cardiovascular disease risk: a longitudinal pilot study

Background

Lecithin-cholesterol acyltransferase (LCAT) is believed to be involved in reverse cholesterol transport, which is known to play a key role in suppression of atherosclerosis. However, recent investigations have demonstrated that higher LCAT activity, measured in terms of the serum cholesterol esterification rate by an endogenous substrate method, is associated with increased formation of triglyceride (TG)-rich lipoproteins (TRLs), leading to a decrease in the low-density lipoprotein (LDL) particle size. The purpose of this hospital-based longitudinal study was to clarify the causal relationship between changes in the LCAT activity and changes in the LDL-particle size.

Methods

The subjects were a total of 335 patients, derived from our previous study cohort, with one or more risk factors for atherosclerotic cardiovascular disease (ASCVD). For this study, we measured the LDL-particle size (relative LDL migration [LDL-Rm value]) by polyacrylamide gel electrophoresis in the subjects, along with the changes in the LCAT activity, at the end of a follow-up period of at least 1 year.

Results

The results revealed that the absolute change (Δ) in the LDL-particle size increased significantly as the quartile of Δ LCAT activity increased (p =?0.01). A multi-logistic regression adjusted-analysis revealed that Δ LCAT activity in the fourth quartile as compared to that in the first quartile was independently predictive of an increased LDL-particle size (odds ratio [95% confidence interval]: 2.03 [1.02/4.04], p =?0.04). Moreover, the ? LCAT activity was also positively correlated with ? TRL-related markers (i.e., TG, remnant particle-like cholesterol [RLP-C], apolipoprotein B, apolipoprotein C-2, and apolipoprotein C-3).

Conclusions

The results lend support to the hypothesis that increased LCAT activity may be associated with increased formation of TRLs, leading to a reduction in the LDL-particle size in patients at a high risk for ASCVD. To reduce the risk of ASCVD, it may be important to focus not only on the quantitative changes in the serum LDL-cholesterol levels, but also on the LCAT activity.

Trial registration

UMIN (https://upload.umin.ac.jp/cgi-bin/ctr/ctr_reg_list.cgi) Study ID: UMIN000033228 retrospectively registered 2 July 2018.

     

Chondrogenic differentiation of human mesenchymal stem cells cultured in a cobweb-like biodegradable scaffold

Human mesenchymal stem cells (MSCs) were cultured in vitro in a cobweb-like biodegradable polymer scaffold: a poly(dl-lactic-co-glycolic acid)-collagen hybrid mesh in serum-free DMEM containing TGF-beta3 for 1-10 weeks. The cells adhered to the hybrid mesh, distributed evenly, and proliferated to fill the spaces in the scaffold. The ability of the cells to express gene encoding type I collagen decreased, whereas its ability to express type II collagen and aggrecan increased. Histological examination by HE staining indicated that the cells showed fibroblast morphology at the early stage and became round after culture for 4 weeks. The cartilaginous matrices were positively stained by safranin O and toluidine blue. Immunostaining with anti-type II collagen and anti-cartilage proteoglycan showed that type II collagen and cartilage proteoglycan were detected around the cells. In addition, a homogeneous distribution of cartilaginous extracellular matrices was detected around the cells. These results suggest the chondrogenic differentiation of the mesenchymal stem cells in the hybrid mesh. The PLGA-collagen hybrid mesh enabled the aggregation of mesenchymal stem cells and provided a promotive microenvironment for the chondrogenic differentiation of the MSCs.     

Multiple sampling for increasing the diagnostic sensitivity of nipple aspirate fluid for atypical cytology

OBJECTIVE: To determine if repeated collection of nipple aspirate fluid (NAF) can improve the diagnostic sensitivity for cytologic atypia, a marker of increased risk of breast cancer. STUDY DESIGN: Two hundred sixty-seven women without known breast disease volunteered for NAF cytology at 5 6-month intervals over 2 years. NAF samples were prepared on Millipore filters (Millipore Filter Corp., Bedford, Massachusetts, U.S.A.) and stained with a modified Papanicolaou method. Fluid availability and cellular abnormalities were evaluated for each collection attempt. Cellular findings were classified as benign, hyperplasia or atypia. RESULTS: NAF was obtained from 178 women (66.6%) at the first visit and from an additional 15, 10, 2 and 4 women at visits 2, 3, 4 and 5, respectively, for a cumulative total of 78.2% by visit 5. The number of women yielding NAF containing hyperplastic or atypical epithelial cells was determined at each visit. Hyperplastic cells were found in 34 (19.1%) at visit 1 and in an additional 20, 10, 5 and 4 women at visits 2, 3, 4 and 5, respectively. Atypical epithelial cells were present in 12 (6.7%) women at the initial visit and in an additional 11, 7, 5 and 1 women at visits 2, 3, 4 and 5, respectively, for a cumulative percent of 18.2 at visit 5. NAF could not be obtained from 58 women at any visit. CONCLUSION: These findings suggest that an optimum collection method for NAF cytology should consist of at least 3 or 4 separate fluid aspiration attempts. Reviewing repeated multiple samples instead of 1 increases the number of women who can be evaluated and the likelihood of detecting cytologic atypia.