Lactobacillus acidophilus K301 Inhibits Atherogenesis via Induction of 24 (S), 25-Epoxycholesterol-Mediated ABCA1 and ABCG1 Production and Cholesterol Efflux in Macrophages

Lactobacillus acidophilus species are well-known probiotics with the beneficial activity of regulating cholesterol levels. In this study, we showed that L. acidophilus K301 reduced the level of cholesterol through reverse transport in macrophages. L. acidophilus K301 upregulated the mRNA and protein levels of genes such as ATP-binding cassette A1 (ABCA1) and ATP-binding cassette G1 (ABCG1) under the control of liver X receptor (LXR), resulting in increased apoA-I-dependent cholesterol efflux in phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 cells. L. acidophilus K301 induced both ABCA1 and ABCG1 through the endogenous LXR agonist 24(S), 25-epoxcycholesterol, which is synthesized by intracellular cholesterol synthetic pathways. In vivo studies using L. acidophilus K301-treated ApoE^-/- mice showed reduced accumulation of lipoproteins in the arterial lumen. The inhibitory effects of L. acidophilus K301 on accumulation of lipoprotein in atherosclerotic plaques were mediated by the induction of squalene reductase (SQLE) and oxidosqualene cyclase (OSC) and resulted in ABCA1-mediated cholesterol efflux. Taken together, our findings revealed that Lactobacillus acidophilus K301 regulates the expression of genes related to cholesterol reverse transport via the induction of endogenous LXR agonist, suggesting the therapeutic potential of Lactobacillus acidophilus K301 as an anti-atherosclerotic agent.     

Effects of EDTA treatment upon the protein subunit composition and mechanical properties of mammalian single skeletal muscle fibers

Considerable interest has been focused on the role of myosin light chain LC(2) in the contraction of vertebrate striated muscle. A study was undertaken to further our investigations (Moss, R.L., G.G. Giulian, and M.L. Greaser, 1981, J. Biol. Chem., 257:8588-8591) of the effects of LC(2) removal upon contraction in skinned fibers from rabbit psoas muscles. Isometric tension and maximum velocity of shortening, V(max), were measured in fiber segments prior to LC(2) removal. The segments were then bathed at 30 degrees C for up to 240 min in a buffer solution containing 20 mM EDTA in order to extract up to 60 percent of the LC(2). Troponin C (TnC) was also partially removed by this procedure. Mechanical measurements were done following the EDTA extraction and the readditions of first TnC and then LC(2) to the segments. The protein subunit compositions of the same fiber segments were determined following each of these procedures by SDS PAGE of small pieces of the fiber. V(max) was found to decrease as the LC(2) content of the fiber segments was reduced by increasing the duration of extraction. EDTA treatment also resulted in substantial reductions in tension due mainly to the loss of TnC, though smaller reductions due to the extraction of LC(2) were also observed. Reversal of the order of recombination of LC(2) and TnC indicated that the reduction in V(max) following EDTA treatment was a specific effect of LC(2) removal. These results strongly suggest that LC(2) may have roles in determining the kinetics and extent of interaction between myosin and actin.     

Nucleotide sequence analysis of the lemur beta-globin gene family: evidence for major rate fluctuations in globin polypeptide evolution

Lemur beta-related globin genes have been isolated and sequenced. Orthology of prosimian and human epsilon-, gamma-, and beta-related globin genes was established by dot-matrix analysis. All of these lemur globin genes potentially encode functional beta-related globin polypeptides, though precisely when the gamma-globin gene is expressed remains unknown. The organization of the 18-kb brown lemur beta-globin gene cluster (5' epsilon-gamma-[psi eta-delta]-beta 3') is consistent with its evolution by contraction via unequal crossing-over from the putative ancestral mammalian beta-globin gene cluster (5' epsilon-gamma- eta-delta-beta 3'). The dwarf lemur nonadult globin genes are arranged as in the brown lemur. Similar levels of synonymous (silent) nucleotide substitutions and noncoding DNA sequence differences have accumulated between species in all of these genes, suggesting a uniform rate of noncoding DNA divergence throughout primate beta-globin gene clusters. These differences are comparable with those observed in the nonfunctional psi eta pseudogene and have therefore accumulated at the presumably maximal neutral rate. In contrast, nonsynonymous (replacement) nucleotide substitutions show a significant heterogeneity in distribution for both the same gene in different lineages and different genes in the same lineage. These major fluctuations in replacement but not silent substitution rates cannot be attributed to changes in mutation rate, suggesting that changes in the rate of globin polypeptide evolution in primates is not governed solely by variable mutation rates.      

The physiological basis of seed dormancy in Avena fatua. II. On the involvement of alternative respiration in the stimulation of germination by sodium azide

Chromatography on DEAE-cellulose of an extract from etiolated leaves of sorghum ( Sorghum vulgare Pers. cv. INRA 450), a C₄ plant, gave only one form of phosphoenol pyruvate carboxylase with functional and regulatory properties of a C₃ type plant enzyme. Greening of the leaves resulted in a significant increase in activity. This increase was due to the appearance of a new form of the enzyme, which eluted at lower ionic strength and exhibited new properties. This form was glucose-6-P activated and showed a sigmoidal curve response to the concentration of the substrate phosphoerralpyruvate. These kinetic properties are typical of a C₄ plant enzyme.     

The 1,2,3-triazole derivative KP-A021 suppresses osteoclast differentiation and function by inhibiting RANKL-mediated MEK-ERK signaling pathway

The triazole family of compounds has been implicated in modulating various biological processes such as inflammation, tumorigenesis, and infection. To our knowledge, this is the first study to demonstrate the effects of 1,2,3-triazole substituted biarylacrylonitrile compounds, including KP-A021, on the differentiation and function of osteoclasts. KP-A021 and its triazole derivatives, at a concentration that does not cause a cytotoxic response in bone marrow macrophages (BMMs), significantly inhibited osteoclast differentiation induced by receptor activator of nuclear factor-κB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) as assessed by tartrate-resistant acid phosphatase (TRAP) staining. KP-A021 also dramatically inhibited the expression of marker genes associated with osteoclast differentiation, such as TRAP, cathepsin K (Cat K), dendritic cell-specific transmembrane protein (DC-STAMP), and nuclear factor of activated T-cells, cytoplasmic 1 (NFATc1). Furthermore, KP-A021 inhibited actin ring formation in osteoclasts as well as resorption pit formation induced by osteoclasts. Analysis of the signaling pathway for KP-A021 indicated that this triazole compound inhibited the RANKL-induced activation of extracellular signal-regulated kinase (ERK) and its upstream signaling molecule, mitogen-activated protein kinase kinase1/2 (MEK1/2). Taken together, these results demonstrate that KP-A021 has an inhibitory effect on the differentiation and function of osteoclasts via modulation of the RANKL-induced activation of the MEK-ERK pathway.     

Analysis of neuron-like differentiation of human bone marrow mesenchymal stem cells

The objective of the study was to evaluate differentiation of human bone marrow mesenchymal stem cells into true or pseudo neurons after treating with chemical induction medium in vitro. The morphological changes were assessed using interference contrast microscopy. Immunocytochemistry and Western blotting were performed using neuronal markers. Further evaluation was conducted with proteomic profiling, DNA microarray analysis and the whole-cell patch clamp test. After three hours of treatment with chemical induction medium, nearly three-fourths of the hMSCs changed to cells with a neuronal phenotype. The results of immunocytochemistry and Western blotting showed a high expression of neuronal markers in these cells at 3 h which decreased at 24 h. The proteomics analysis showed no change of proteins related to neuronal differentiation. DNA microarray showed downregulation of neuron related genes. The patch clamp test was unable to demonstrate any similarity to true neurons. Our findings suggest that neuron-like cells derived from chemical induction of hMSCs are not the genuine neurons as they resemble true neurons phenotypically but are different in genotypic and electrophysiological characteristics.