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Mesenchymal stem cells (MSCs) are increasingly being reported as occurring in a variety of tissues. Although MSCs from human bone marrow are relatively easy to harvest, the isolation of rodent MSCs is more difficult, thereby limiting the number of experiments in vivo. To determine a suitable cell source, we isolated rat MSCs from bone marrow, synovium, periosteum, adipose, and muscle and compared their properties for yield, expansion, and multipotentiality. After two passages, the cells in each population were CD11b (-), CD45 (-), and CD90 (+). The colony number per nucleated cells derived from synovium was 100-fold higher than that for cells derived from bone marrow. With regard to expansion potential, synovium-derived cells were the highest in colony-forming efficiency, fold increase, and growth kinetics. An in vitro chondrogenesis assay demonstrated that the pellets derived from synovium were heavier, because of their greater production of cartilage matrix, than those from other tissues, indicating their superiority in chondrogenesis. Synovium-derived cells retained their chondrogenic potential after a few passages. The Oil Red-O positive colony-rate assay demonstrated higher adipogenic potential in synovium- and adipose-derived cells. Alkaline phosphatase activity was greater in periosteum- and muscle-derived cells during calcification. The yield and proliferation potential of rat MSCs from solid tissues was much better than those from bone marrow. In particular, synovium-derived cells had the greatest potential for both proliferation and chondrogenesis, indicating their usefulness for cartilage study in a rat model.

Chlorophylls are essential components of the photosynthetic apparati that sustain all of the life forms that ultimately depend on solar energy. However, a drawback of the extraordinary photosensitizing efficiency of certain chlorophyll species is their ability to generate harmful singlet oxygen. Recent studies have clarified the catabolic processes involved in the detoxification of chlorophylls in land plants, but little is understood about these strategies in aquatic ecosystem. Here, we report that a variety of heterotrophic protists accumulate the chlorophyll a catabolite 13², 17³-cyclopheophorbide a enol (cPPB-aE) after their ingestion of algae. This chlorophyll derivative is nonfluorescent in solution, and its inability to generate singlet oxygen in vitro qualifies it as a detoxified catabolite of chlorophyll a. Using a modified analytical method, we show that cPPBaE is ubiquitous in aquatic environments, and it is often the major chlorophyll a derivative. Our findings suggest that cPPB-aE metabolism is one of the most important, widely distributed processes in aquatic ecosystems. Therefore, the herbivorous protists that convert chlorophyll a to cPPB-aE are suggested to play more significant roles in the modern oceanic carbon flux than was previously recognized, critically linking microscopic primary producers to the macroscopic food web and carbon sequestration in the ocean.

This study investigated the taxonomic affiliation of the algal strain nak-9, which has been reported to absorb radioactive cesium with high efficiency, using light and electron microscopy, and molecular phylogenetic analysis based on 18S ribosomal RNA gene (rDNA) sequences. This alga is spherical and coccoid, with a smooth cell wall, large vacuole, crystalline structure, reddish globule, and refractile granules (lamellate vesicles). The cells possess one to several greenish parietal chloroplasts with a bulging pyrenoid surrounded by lamellate vesicles. The chloroplasts include orderly thylakoid lamellae but no girdle lamella. Molecular phylogenetic analysis suggests that strain nak-9 is a member of the eustigmatophycean clade, which includes Goniochloris, Pseudostaurastrum, and Trachydiscus. On the basis of these results, we propose that strain nak-9 (NIES-2860) comprises a new species and new genus of the Eustigmatophyceae, Vacuoliviride crystalliferum gen. et sp. nov.

The Fukushima 1 Nuclear Power Plant accident in March 2011 released an enormously high level of radionuclides into the environment, a total estimation of 6.3 × 10 17 Bq represented by mainly radioactive Cs, Sr, and I. Because these radionuclides are biophilic, an urgent risk has arisen due to biological intake and subsequent food web contamination in the ecosystem. Thus, urgent elimination of radionuclides from the environment is necessary to prevent substantial radiopollution of organisms. In this study, we selected microalgae and aquatic plants that can efficiently eliminate these radionuclides from the environment. The ability of aquatic plants and algae was assessed by determining the elimination rate of radioactive Cs, Sr and I from culture medium and the accumulation capacity of radionuclides into single cells or whole bodies. Among 188 strains examined from microalgae, aquatic plants and unidentified algal species, we identified six, three and eight strains that can accumulate high levels of radioactive Cs, Sr and I from the medium, respectively. Notably, a novel eustigmatophycean unicellular algal strain, nak 9, showed the highest ability to eliminate radioactive Cs from the medium by cellular accumulation. Our results provide an important strategy for decreasing radiopollution in Fukushima area.

The purpose of this study was to determine whether the expression of ER stress-related factors IRE1α, apoptosis signal-regulating kinase 1 (ASK1), SAPK/ERK kinase 1 (SEK1) and c-Jun N-terminal kinase (JNK) is associated with the damaged retinal neurons induced by ischemia-reperfusion injury. After 60 minutes of ischemia, the rat retinas were reperfused, and retinas were isolated and fixed after 6, 9, 12, 18, and 24 hours, and 2, 5, and 9 days of reperfusion. Cryosections were immunostained with Fluoro-Jade B, a degenerating neuron marker to label degenerating neurons. Semi-quantitative analysis of the expression of IRE1α, ASK1, SEK1, and JNK were performed in both control and ischemic retinas. In ischemic retinas, the intensities of IRE1α immunoreactivity in the ganglion cell layer (GCL) were significantly higher than in the control retinas. In ischemic retinas, the numbers of SEK1-, ASK1-, and JNK-positive cells were significantly increased in the GCL compared to those in the control retinas. In addition, the cells that were positive for SEK1-, ASK1-, and JNK were also positive for Fluoro-Jade B-positive cells. These results indicate that the increased expression of ER stress-related factors was, in part, associated with the retinal neuronal abnormalities after ischemia-reperfusion injury in rat retinas.

J. Scott, A. Yokoyama, C. Billard, J. Fresnel, Y. Hara, K.A. West and J.A. West. 2008. Neorhodella cyanea, a new genus in the Rhodellophyceae (Rhodophyta). Phycologia 47: 560-572. DOI: 10.2216/08-27.1 The red algal unicell Rhodella cyanea (Rhodellophyceae) was reinvestigated. The cell ultrastructure is clearly dissimilar to that of the two other Rhodella species, R. maculata Evans and R. violacea (Kornmann) Wehrmeyer. Consequently, we have established Neorhodella gen. nov. Neorhodella cyanea possesses a large parietal chloroplast with numerous lobes extending into the cell center. The inner region of each lobe terminates near the central nucleus and contains several thylakoids sparsely covered by opposed, disc-shaped phycobilisomes. These regions are interpreted as multiple pyrenoids. Thylakoids are more numerous in other chloroplast regions where phycobilisomes are alternately spaced. A peripheral encircling thylakoid is absent and plastoglobuli, in unicellular red algae found only in the Rhodellophyceae, are found at the cell periphery. Golgi bodies are exclusively perinuclear, similar to Dixoniella and Glaucosphaera in the class Rhodellophyceae. Golgi cisternae appear closely opposed during some cell cycle stages, a feature found in no other unicells except members of the Rhodellophyceae. Several stages of mitosis were observed in Neorhodella. These suggest a pattern fairly typical of other unicellular red algae. Nucleus-associated organelles are polar rings, the division poles have conspicuous gaps in the mostly intact nuclear envelope and microtubules emanate from a flattened plate of membranes and moderately electron dense material, attaching to small kinetochores during mitosis and terminating near the former poles of telophase nuclei during migration of daughter nuclei. The low molecular weight carbohydrate of Neorhodella is mannitol, similar to Rhodella and Dixoniella.

Although it was reported that protein 4.1 G, a cytoskeletal protein characterized by its general expression in the body, interacts with some signal transduction molecules in the central nervous system (CNS), its distribution and significance in vivo remained to be elucidated. In the present study, we have identified 4.1 G-positive cells in the rodent CNS, and demonstrated its immunolocalization in the developing mouse CNS. In the rodent CNS, 4.1 G was colocalized with markers for microglia, such as CD45, OX-42 and ionized calcium-binding adapter molecule 1 (Iba1), but not with markers for neuronal or other glial cells. Additionally, colocalization of 4.1 G and A1 adenosine receptor was observed in the mouse cerebrum. In a mixed glial culture, most OX-42-positive microglia were positive for 4.1 G, and 4.1 G isoforms of the same molecular weight as in the rat brain were expressed in cultured microglia, where 4.1 G mRNA was detected by RT-PCR. In the developing mouse cerebral cortex, 4.1 G was detected in immature microglia, which were positive for Iba1. These results indicate that 4.1 G in the CNS is mainly distributed in microglia in vivo. Considering the interactions between 4.1 G and the signal transduction molecules, putative roles have been proposed for 4.1 G in microglial functions in the CNS.

Objective/Methods: Seckel syndrome is a rare form of primordial dwarfism and most of the previous reports have been limited to postnatal findings. We report on a fetus showing severe microcephaly, intrauterine growth restriction and a few gyri with shallow sulci on the fetal brain suggesting cortical dysplasia, followed by ultrasound and magnetic resonance imaging in the prenatal period. Results: Cardiotocograph revealed a reassuring fetal status throughout the whole pregnancy period. A male infant weighing 1,556 g was delivered at 39 weeks’ gestation, and a diagnosis of Seckel syndrome was made based on postnatal typical findings. Although previous reports on prenatal findings of Seckel syndrome are quite limited, we think that our case presents typical features of a fetus affected by this syndrome. Conclusions: When prenatal ultrasound shows severe microcephaly and intrauterine growth restriction, this rare syndrome should be included in the differential diagnosis. Moreover, magnetic resonance imaging of the affected fetal brain provides further diagnostic clues.

Extant eukaryote ecology is primarily sustained by oxygenic photosynthesis, in which chlorophylls play essential roles. The exceptional photosensitivity of chlorophylls allows them to harvest solar energy for photosynthesis, but on the other hand, they also generate cytotoxic reactive oxygen species. A risk of such phototoxicity of the chlorophyll must become particularly prominent upon dynamic cellular interactions that potentially disrupt the mechanisms that are designed to quench photoexcited chlorophylls in the phototrophic cells. Extensive examination of a wide variety of phagotrophic, parasitic, and phototrophic microeukaryotes demonstrates that a catabolic process that converts chlorophylls into nonphotosensitive 13 2 ,17 3 -cyclopheophorbide enols (CPEs) is phylogenetically ubiquitous among extant eukaryotes. The accumulation of CPEs is identified in phagotrophic algivores belonging to virtually all major eukaryotic assemblages with the exception of Archaeplastida, in which no algivorous species have been reported. In addition, accumulation of CPEs is revealed to be common among phototrophic microeukaryotes (i.e., microalgae) along with dismantling of their secondary chloroplasts. Thus, we infer that CPE-accumulating chlorophyll catabolism (CACC) primarily evolved among algivorous microeukaryotes to detoxify chlorophylls in an early stage of their evolution. Subsequently, it also underpinned photosynthetic endosymbiosis by securing close interactions with photosynthetic machinery containing abundant chlorophylls, which led to the acquisition of secondary chloroplasts. Our results strongly suggest that CACC, which allowed the consumption of oxygenic primary producers, ultimately permitted the successful radiation of the eukaryotes throughout and after the late Proterozoic global oxygenation.

Graft implantation is one of the more popular procedures for repairing cartilage defects; however, sacrifices of the donor site have been an issue. Mesenchymal stem cells (MSCs) are a fascinating source for regenerative medicine because they can be harvested in a less invasive manner and are easily isolated and expanded, with multi-potentiality including chondrogenesis. MSCs can be isolated from various adult mesenchymal tissues including synovium. Here, we attempted to form cartilage from the composites of synovium-derived MSCs with collagen gel in vitro. After 21 days of culture, the composites had increased their cartilage matrix, as demonstrated by toluidine blue staining and immunohistochemistry for type II collagen. The composites consisting of 5 x 10(7) and 10(8) cells/ml in gel were richer in proteoglycans than those consisting of lower cell densities. After 1 day, MSCs/gel composites contracted and the diameter decreased by 30%; however, they were stable thereafter. Round cells with short processes producing collagen fibrils showing a similar morphology to that of chondrocytes were seen in the composites by transmission electron microscopy. During composite culture, chondroitin sulfate and mRNA expression for cartilage-related genes increased, demonstrating cartilage maturation. Using an optimized method, we obtained cartilage discs with a diameter of 7 mm and a thickness of 500 microm. Our procedure should thus make it possible to produce a large cartilage matrix in vitro. The tissue engineering of autologous cartilage from the composites of synovium-derived MSCs with collagen gel in vitro for transplantation may be a future alternative to graft implantation for patients with cartilage defects.