Ancient Mitochondrial DNA Reveals the Origin of Sus scrofa from Rebun Island, Japan

The Kabukai A site (5 to 8C A.D.) of the Okhotsk cultural area is on Rebun Island, a small island near the coast, north–northwest of Hokkaido, Japan. Specimens of Sus scrofa, called the Sakhalin pig, were discovered in five cultural layers at the Kabukai A site. Ancient DNA was extracted from the remains of 42 Sakhalin pig bones. Thirty-nine nucleotide sequences of the 574-bp mitochondrial DNA control region, estimated to have originated from at least 21 individuals, were amplified and analyzed phylogenetically. Nine distinct haplotypes (A1, A2, A3, B1, B2, C1, C2, D1, and D2) from this site were classified into four haplotype groups (A, B, C, and D) by parsimonious network analysis. Phylogenetic analysis of 9 ancient and 55 modern haplotypes indicated that the population of Sakhalin pigs at the Kabukai A site belonged to two distinct clusters; haplotype groups A and B formed a cluster comprised only of themselves, and haplotype groups C and D belonged to the cluster of one of the two genetic groups of Japanese wild boars uniquely distributed in the western part of Japan, including one northeast Mongolian wild boar. Analysis of the haplotype distribution among three archaeological sites and their historical transitions among the five layers reflecting the cultural periods at the Kabukai A site suggests that the Sakhalin pig populations were introduced from Sakhalin island and the Amur River basin in the northeastern Eurasian continent together with some cultural influences. Received: 18 April 2000 / Accepted: 24 November 2000     

Effect of Amino Acids on Lysosomal Proteolytic Activities in Rat Livers

(R)-2-(4′-Isobutylphenyl)propanoic acid (ibuprofen), (S)-3(4′-isobutylphenyl)butanoic acid and (S)-4-(4′-isobutylphenyl)pentanoic acid were obtained using microbial oxidation of (±)-l-isobutyl-4-(1′ -methyloctyl)benzene by Rhodococcus sp. BPM 1613.     

Biosynthesis of C-labeled branched polysaccharides by pestalotiopsis from C-labeled glucoses and the mechanism of formation

Biosynthesis of branched glucan by Pestalotiopsis from media containing D-(1-¹³C)glucose, D-(2-¹³C)glucose, D-(4-¹³C)glucose, D-(6-¹³C)glucose or a mixture of D-(1-¹³C)glucose and D-(2-¹³C)glucose was carried out to elucidate biosynthetic mechanism of branched polysaccharides. ¹³C NMR spectra of the labeled polysaccharides were determined and assigned. Analysis of ¹³C NMR spectra of glucitol acetates obtained from hydrolysates of the labeled branched polysaccharides indicated that transfer of labeling from C-1 to C-3 and C-6 carbons, from C-2 to C-1, C-3 and C-5 carbons, and from C-6 to C-1 carbon. From the results the percentages of routes via which the polysaccharide is biosynthesized are estimated. They show that the biosynthesis of the polysaccharide via the Embden-Meyerhof pathway and that from lipids and proteins are more active, and the pentose cycle is less active, than in the biosynthesis of cellulose and curdlan. As for the results, labeling at C-6 carbon in the branched polysaccharide cultured from D-(6-¹³C)glucose was low, compared to that of cellulose and curdlan.     

The yeast Tor signaling pathway is involved in G2/M transition via polo-kinase

The target of rapamycin (Tor) protein plays central roles in cell growth. Rapamycin inhibits cell growth and promotes cell cycle arrest at G1 (G0). However, little is known about whether Tor is involved in other stages of the cell division cycle. Here we report that the rapamycin-sensitive Tor complex 1 (TORC1) is involved in G2/M transition in S. cerevisiae. Strains carrying a temperature-sensitive allele of KOG1 (kog1-105) encoding an essential component of TORC1, as well as yeast cell treated with rapamycin show mitotic delay with prolonged G2. Overexpression of Cdc5, the yeast polo-like kinase, rescues the growth defect of kog1-105, and in turn, Cdc5 activity is attenuated in kog1-105 cells. The TORC1-Type2A phosphatase pathway mediates nucleocytoplasmic transport of Cdc5, which is prerequisite for its proper localization and function. The C-terminal polo-box domain of Cdc5 has an inhibitory role in nuclear translocation. Taken together, our results indicate a novel function of Tor in the regulation of cell cycle and proliferation.     

Complete resistance to challenges with Hymenolepis nana cysticercoids derived from mouse, rat and beetle in mice

and 1986. Complete resistance to challenges with Hymenolepis nana cysticercoids derived from mouse, rat and beetle in mice. International Journal for Parasitology 16: 623–628. When BALB/c and dd strains of mice were given eggs of Hymenolepis nana, they all became completely resistant not only to challenge with mouse-derived cysticercoids but also to challenges with rat-derived and beetle-derived cysticercoids. Serum IgG antibodies at 47–60 days post egg inoculation reacted strongly with these three different host-derived cysticercoids when examined by IFA test, but IgA and IgM isotypes reacted very weakly. Antibodies of infected mouse sera (IgG, IgM and IgA were examined) reacted not only with the protoscolex (scolex of the excysted juvenile) but also with the outer cyst wall. By contrast, uninfected mouse sera and immune sera prepared seven days post cysticercoid inoculation did not react at all. Antigens of both cyst wall and protoscolex appeared to be of parasite origin and not of host origin, and appeared similar in parasites from the different host species.     

BACE1 modulates filopodia-like protrusions induced by sodium channel beta4 subunit

Processing of APP by BACE1 plays a crucial role in the pathogenesis of Alzheimer disease (AD). Recently, the voltage-gated sodium channel (Na_v) β4 subunit (β4), an auxiliary subunit of Na_v that is supposed to serve as a cell adhesion molecule, has been identified as a substrate for BACE1. However, the biological consequence of BACE1 processing of β4 remains illusive. Here, we report the biological effects of β4 processing by BACE1. Overexpression of β4 in Neuro2a cells promoted neurite extension and increased the number of F-actin rich filopodia-like protrusions. While coexpression of BACE1 together with β4 further accelerated neurite extension, the number of filopodia-like protrusions was reduced. Overexpression of C-terminal fragment of β4 that was generated by BACE1 (β4-CTF) partially recapitulated the results obtained with BACE1 overexpression. These results suggest that the processing of β4 by BACE1 regulates neurite length and filopodia-like protrusion density in neurons.     

Nicastrin, presenilin, APH-1, and PEN-2 form active gamma-secretase complexes in mitochondria

Mitochondria are central in the regulation of cell death. Apart from providing the cell with ATP, mitochondria also harbor several death factors that are released upon apoptotic stimuli. Alterations in mitochondrial functions, increased oxidative stress, and neurons dying by apoptosis have been detected in Alzheimer's disease patients. These findings suggest that mitochondria may trigger the abnormal onset of neuronal cell death in Alzheimer's disease. We previously reported that presenilin 1 (PS1), which is often mutated in familial forms of Alzheimer's disease, is located in mitochondria and hypothesized that presenilin mutations may sensitize cells to apoptotic stimuli at the mitochondrial level. Presenilin forms an active gamma-secretase complex together with Nicastrin (NCT), APH-1, and PEN-2, which among other substrates cleaves the beta-amyloid precursor protein (beta-APP) generating the amyloid beta-peptide and the beta-APP intracellular domain. Here we have identified dual targeting sequences (for endoplasmic reticulum and mitochondria) in NCT and showed expression of NCT in mitochondria by immunoelectron microscopy. We also showed that NCT together with APH-1, PEN-2, and PS1 form a high molecular weight complex located in mitochondria. gamma-secretase activity in isolated mitochondria was demonstrated using C83 (alpha-secretase-cleaved C-terminal 83-residue beta-APP fragment from BD8 cells lacking presenilin and thus gamma-secretase activity) or recombinant C100-Flag (C-terminal 100-residue beta-APP fragment) as substrates. Both systems generated an APP intracellular domain, and the activity was inhibited by the gamma-secretase inhibitors l-685,458 or Compound E. This novel localization of NCT, PS1, APH-1, and PEN-2 expands the role and importance of gamma-secretase activity to mitochondria.     

Functions of toll-like receptors: lessons from KO mice

The innate immune response is a first-line defense system in which individual Toll-like receptors (TLRs) recognize distinct pathogen-associated molecular patterns (PAMPs) and exert subsequent immune responses against a variety of pathogens. TLRs are composed of an extracellular leucine-rich repeat (LRR) domain and a cytoplasmic domain that is homologous to that of the IL-IR family. Upon stimulation, TLR recruits a cytoplasmic adaptor molecule MyD88, then IL-IR-associated kinase (IRAK), and finally induces activation of NF-kappaB and MAP kinases. However, the responses to TLR ligands differ, indicating the diversity of TLR signaling pathways. Besides MyD88, several novel adaptor molecules have recently been identified. Differential utilization of these adaptor molecules may provide the specificity in the TLR signaling.     

Anti-monocyte chemoattractant protein-1 gene therapy attenuates pulmonary hypertension in rats

Monocyte/macrophage chemoattractant protein-1 (MCP-1), a potent chemoattractant chemokine and an activator for mononuclear cells, may play a role in the initiation and/or progression of pulmonary hypertension (PH). To determine whether blockade of a systemic MCP-1 signal pathway in vivo may prevent PH, we intramuscularly transduced a naked plasmid encoding a 7-NH(2) terminus-deleted dominant negative inhibitor of the MCP-1 (7ND MCP-1) gene in monocrotaline-induced PH. We also simultaneously gave a duplicate transfection at 2-wk intervals or skeletal muscle-directed in vivo electroporation (EP) to evaluate whether a longer or higher expression might be more effective. The intramuscular reporter gene expression was enhanced 10 times over that by EP than by simple injection, and a significant 7ND MCP-1 protein in plasma was detected only in the EP group. 7ND MCP-1 gene transfer significantly inhibited the progression of MCT-induced PH as evaluated by right ventricular systolic pressure, right ventricular hypertrophy, medial hypertrophy of pulmonary arterioles, and mononuclear cell infiltration into the lung. Differential effects of longer or higher transgene expression were not apparent. Although the in vivo kinetics of 7ND MCP-1 gene therapy should be studied further, these encouraging results suggest that an anti-inflammatory strategy via blockade of the MCP-1 signal pathway may be an alternative approach to treat subjects with PH.