Adaptation to the shallow sea floor environment of a species of marine worms, Oligobrachia mashikoi, generally inhabiting deep-sea water.

Beard worms from the family Siboglinidae, are peculiar animals and are known for their symbiotic relationships with sulfur bacteria. Most Siboglinids inhabit the deep-sea floor, thus making difficult to make any observations in situ. One species, Oligobrachia mashikoi, occurs in the shallow depths (24.

Neuritogenic steroid glycosides from crown-of-thorns starfish: Possible involvement of p38 mitogen-activated protein kinase and attenuation of cognitive impairment in senescence-accelerated mice (SAMP8) by peripheral administration.

Novel steroid glycosides, acanthasterosides A1, B1, and B3, have been isolated from the crown-of-thorns starfish Acanthaster planci. Acanthasterosides B1 and B3 having two separated xyloses induced neurite outgrowth as like as nerve growth factor (NGF) in the rat pheochromocytoma cell line PC12, whereas acanthasteroside A1, having one xylose, did not induce neurite outgrowth. The acanthasteroside B3 induced neuritogenesis via the significant activation of p38 mitogen-activated protein kinase after the activation of the small G-protein Cdc42 rather than via Ras-MEK-ERK pathway that is predominantly activated by NGF.

In vivo activation of PEGylated long circulating lipid nanoparticle to achieve efficient siRNA delivery and target gene knock down in solid tumors.

We developed a lipid nanoparticle formulation (LNPK15) to deliver siRNA to a tumor for target gene knock down. LNPK15 is highly PEGylated with 3.3% 1,2-distearoyl-sn-glycero-3-phosphatidylethanolamine-N-(polyethylene glycol-2000) (PEG-DSPE) and shows a long duration: the half-lives of siRNA in LNPK15 were 15.

Sardine procalcitonin amino-terminal cleavage peptide has a different action from calcitonin and promotes osteoblastic activity in the scales of goldfish.

The nucleotide sequence of a sardine preprocalcitonin precursor has been determined from their ultimobranchial glands in the present study. From our analysis of this sequence, we found that sardine procalcitonin was composed of procalcitonin amino-terminal cleavage peptide (N-proCT) (53 amino acids), CT (32 amino acids), and procalcitonin carboxyl-terminal cleavage peptide (C-proCT) (18 amino acids). As compared with C-proCT, N-proCT has been highly conserved among teleosts, reptiles, and birds, which suggests that N-proCT has some bioactivities.

Evidence for Conservation of the Calcitonin Superfamily and Activity-regulating Mechanisms in the Basal Chordate Branchiostoma floridae: INSIGHTS INTO THE MOLECULAR AND FUNCTIONAL EVOLUTION IN CHORDATES.

The calcitonin (CT)/CT gene-related peptide (CGRP) family is conserved in vertebrates. The activities of this peptide family are regulated by a combination of two receptors, namely the calcitonin receptor (CTR) and the CTR-like receptor (CLR), and three receptor activity-modifying proteins (RAMPs). Furthermore, RAMPs act as escort proteins by translocating CLR to the cell membrane.

A case of collagenous gastritis resembling nodular gastritis in endoscopic appearance.

A 25-year-old Japanese female was referred to our clinic for the investigation of moderate iron-deficiency anemia and epigastralgia. Endoscopic examination showed diffuse mucosal nodules in the gastric body resembling nodular gastritis, but this pattern was not observed in the antrum. Histology of the gastric biopsies taken from the gastric body showed mild atrophic mucosa with chronic active inflammation.

Static and dynamic hypergravity responses of osteoblasts and osteoclasts in medaka scales.

Fish scales are a form of calcified tissue similar to that found in human bone. In medaka scales, we detected both osteoblasts and osteoclasts and subsequently developed a new scale assay system. Using this system, we analyzed the osteoblastic and osteoclastic responses under 2-, 3-, and 4-gravity (G) loading by both centrifugation and vibration.

Prostaglandin E₂ increases both osteoblastic and osteoclastic activity in the scales and participates in calcium metabolism in goldfish.

Using our original in vitro assay system with goldfish scales, we examined the direct effect of prostaglandin E₂ (PGE₂) on osteoclasts and osteoblasts in teleosts. In this assay system, we measured the activity of alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) as respective indicators of each activity in osteoblasts and osteoclasts. ALP activity in scales significantly increased following treatment at high concentration of PGE₂(10⁻⁷ and 10⁻⁶ M) over 6 hrs of incubation.

Cloning of two members of the calcitonin-family receptors from stingray, Dasyatis akajei: possible physiological roles of the calcitonin family in osmoregulation.

In cartilaginous fish, two cDNAs encoding calcitonin-family receptors were isolated for the first time from the stingray brain. The open reading frame of one receptor cDNA coded a 525-amino acid protein. The amino acid identity of this receptor to human calcitonin-receptor-like receptor (CRLR) is 64.

Tributyltin-binding protein type 1, a lipocalin, prevents inhibition of osteoblastic activity by tributyltin in fish scales.

Tributyltin-binding protein type 1 (TBT-bp1) is a member of the lipocalin family of proteins which bind to small hydrophobic molecules. In this study, we expressed a recombinant TBT-bp1 (rTBT-bp1, ca. 35kDa) in a baculovirus expression system and purified the protein from the hemolymph of silkworm larvae injected with recombinant baculovirus.

Parathyroid hormone 1 (1-34) acts on the scales and involves calcium metabolism in goldfish.

The effect of fugu parathyroid hormone 1 (fugu PTH1) on osteoblasts and osteoclasts in teleosts was examined with an assay system using teleost scale and the following markers: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Synthetic fugu PTH1 (1-34) (100pg/ml-10ng/ml) significantly increased ALP activity at 6h of incubation. High-dose (10ng/ml) fugu PTH1 significantly increased ALP activity even after 18h of incubation.

Direct evidence that extracellular giant hemoglobin is produced in chloragogen tissues in a beard worm, Oligobrachia mashikoi (Frenulata, Siboglinidae, Annelida).

In Oligobrachia mashikoi, a mouthless and gutless polychaete known as a beard worm, sites of production of extra-cellular giant hemoglobin were examined with whole-mount in-situ hybridization and semi-quantitative RT-PCR. An RNA probe was prepared from mRNA of the A2-globin subunit. Clear signals were obtained from a peritoneal membrane covering the trophosome in the posterior body in all seven individuals examined in this study.

Expression levels of hormone receptors and bone morphogenic protein in fins of medaka.

In the genus Oryzias, the morphologies of the dorsal and anal fins are typical secondary sex characters. In the Japanese medaka (Oryzias latipes) and Thai medaka (Oryzias minutillus), androgen receptor (AR) expression levels in the dorsal, anal, and pectoral fins were higher in males than in females. Conversely, in both species estrogen receptor (ER) beta expression levels in the dorsal and anal fins were higher in females than in males.

Structural basis for the heterotropic and homotropic interactions of invertebrate giant hemoglobin.

The oxygen binding properties of extracellular giant hemoglobins (Hbs) in some annelids exhibit features significantly different from those of vertebrate tetrameric Hbs. Annelid giant Hbs show cooperative oxygen binding properties in the presence of inorganic cations, while the cooperativities of vertebrate Hbs are enhanced by small organic anions or chloride ions. To elucidate the structural basis for the cation-mediated cooperative mechanisms of these giant Hbs, we determined the crystal structures of Ca2+- and Mg2+-bound Hbs from Oligobrachia mashikoi at 1.

Anuran Calcitonins are Diverse in Lower Vertebrates.

We investigated the nucleotide sequences of cDNA fragments coding calcitonin from ultimobranchial glands in 2 species of urodelans (1 salamander and 1 newt) and 4 species of anurans (1 toad and 3 frogs) by the reverse transcription polymerase chain reaction (RT-PCR) method and rapid amplification of cDNA ends (RACE)-PCR method. The salamander and newt calcitonins were each 97% and 94% similar to the lungfish and caiman calcitonins that we have already reported, in the amino acid sequences. However, anuran calcitonins were not only dissimilar (63-81%) to the lungfish and caiman calcitonins but also diversified (59-91%) even among anurans.

Unpaired Ultimobranchial Glands of the African Lungfish, Protopterus dolloi.

The ultimobranchial glands of juvenile African lungfish (Protopterus dolloi) (14 individuals; total body length 25-205 mm) were immunohistochemically examined. In individuals larger than 36 mm, one ultimobranchial gland was close to the left afferent branchial arteries. The topography of the ultimobranchial gland was similar to that of salamanders and sharks, but not to teleosts.

Alpha-glucosidase-like activity detected in a siboglinid polychaete, Oligobrachia mashikoi.

Siboglinid worms live on carbohydrates produced by symbiotic bacteria. In this study, alpha-glucosidase-like activity was detected in the surface of the body and in the trophosome of Oligobrachia mashikoi. The enzyme exhibiting this activity was partially purified by consecutively applying the crude enzyme extract to Con-A-Sepharose and Sephadex-200 HR columns.

Structure of the partially unliganded met state of 400 kDa hemoglobin: insights into ligand-induced structural changes of giant hemoglobins.

Recent crystallographic studies have revealed the structures of some invertebrate extracellular giant hemoglobins of 3,600 kDa or 400 kDa and their common quaternary structure of dodecameric subassembly composed of four kinds of globin subunits (A1, A2, B1, and B2). These results have provided insight into the mechanisms of their unique functional properties of oxygen binding and sulfide binding. All of these structures were solved with oxygenated or CO-liganded forms at low or moderate resolutions.

Distribution and Population of Free-Living Cells Related to Endosymbiont A Harbored in Oligobrachia mashikoi (a Siboglinid Polychaete) Inhabiting Tsukumo Bay.

Beard worms (Siboglinidae, Polychaeta), which lack a mouth and a digestive tract, harbor thioautotrophic or methanotrophic bacteria in special cells called bacteriocytes. These endosymbionts have been considered to be trapped at a specific larval stage from the environment. Although many species of beard worms have been discovered in various abyssal seas, Oligobrachia mashikoi inhabits Tsukumo Bay which is only 25 m deep.

Oxygenation properties of extracellular giant hemoglobin from Oligobrachia mashikoi.

Oxygenation properties of hemoglobin (Hb) from Oligobrachia mashikoi were extensively investigated. Compared to human Hb, Oligobrachia Hb showed a high oxygen affinity (P(50)=1.4 mmHg), low cooperativity (n =1.

Lats2 is an essential mitotic regulator required for the coordination of cell division.

Tumor suppressor Lats2 is a member of the conserved Dbf2 kinase family. It localizes to the centrosome and has been implicated in regulation of the cell cycle and apoptosis. However, the in vivo function of this kinase remains unclear.

Cloning and expression of vacuolar proton-pumping ATPase subunits in the follicular epithelium of the bullfrog endolymphatic sac.

In an investigation aimed at clarifying the mechanism of crystal dissolution of the calcium carbonate lattice in otoconia (the mineral particles embedded in the otolithic membrane) of the endolymphatic sac (ELS) of the bullfrog, cDNAs encoding the A- and E-subunits of bullfrog vacuolar proton-pumping ATPase (V-ATPase) were cloned and sequenced. The cDNA of the A-subunit consisted of an 11-bp 5'-untranslated region (UTR), a 1,854-bp open reading frame (ORF) encoding a protein comprising 617 amino acids with a calculated molecular mass of 68,168 Da, and a 248-bp 3'-UTR followed by a poly(A) tail. The cDNA of the E-subunit consisted of a 72-bp 5'-UTR, a 681-bp ORF encoding a protein of 226 amino acids with a calculated molecular mass of 26,020 Da, and a 799-bp 3'-UTR followed by a poly(A) tail.

Relationship between the lifestyle of a Siboglinid (Pogonophoran) polychaete, Oligobrachia mashikoi, and the total sulfide and nitrogen levels in its habitat.

A gutless polychaete of the family Siboglinidae, Oligobrachia mashikoi, known in the past as a beard worm of the group Pogonophora, inhabits Tsukumo Bay of the Noto Peninsula in the Sea of Japan. Photographs were taken of this polychaete projecting about one third of the length of its tentacles outside of its tube. The tube protruded several mm from the sea bottom.