Inhibitory effect of tumor necrosis factor on gene expression of hormone sensitive lipase in 3T3-L1 adipocytes

Recombinant human tumor necrosis factor (TNF) depressed the activities of both lipoprotein lipase (LPL) and hormone sensitive lipase (HSL) in 3T3-L1 adipocytes, 3 to 24 h after its introduction to the cells. HSL gene expression, as measured by Northern blotting analysis with 32P-labeled cloned HSL-cDNA, was also suppressed. These results suggested that the reduction in HSL activity caused by TNF resulted from inhibited gene expression of the enzyme.     

Applying hydraulic lift in an agroecosystem: forage plants with shoots removed supply water to neighboring vegetable crops

When a plant encounters spatially heterogeneous soil moisture within its root system, usually drier surface and moister subsurface soils, water can move between these layers through the root system, a plant process known as hydraulic lift or redistribution. The water thus transferred is available not only for the plant itself but also for its neighbors. We examined application of this process as a possible biological irrigation tool. As ??donors??, we used perennial forage plants with their shoots removed to minimize the effect of light-interception by them on the ??receiver?? plants growing alongside them. In a horizontally split-root experiment, where an upper container was filled with sand and a lower one with water, superior donor species could maintain the upper sand in a fully hydrated condition for several weeks, increasing stomatal conductance in the receivers. The effects were also confirmed in a water-limited agricultural field, as significant differences were found in canopy temperature and yield in neighboring crop plants in the presence or absence of donor root systems. These results suggest that deep-rooting associate plants with their shoots removed function as an irrigation tool and improve crop production in water-scarce environments.     

Gamma Knife Irradiation of Injured Sciatic Nerve Induces Histological and Behavioral Improvement in the Rat Neuropathic Pain Model

We examined the effects of gamma knife (GK) irradiation on injured nerves using a rat partial sciatic nerve ligation (PSL) model. GK irradiation was performed at one week after ligation and nerve preparations were made three weeks after ligation. GK irradiation is known to induce immune responses such as glial cell activation in the central nervous system. Thus, we determined the effects of GK irradiation on macrophages using immunoblot and histochemical analyses. Expression of Iba-1 protein, a macrophage marker, was further increased in GK-treated injured nerves as compared with non-irradiated injured nerves. Immunohistochemical study of Iba-1 in GK-irradiated injured sciatic nerves demonstrated Iba-1 positive macrophage accumulation to be enhanced in areas distal to the ligation point. In the same area, myelin debris was also more efficiently removed by GK-irradiation. Myelin debris clearance by macrophages is thought to contribute to a permissive environment for axon growth. In the immunoblot study, GK irradiation significantly increased expressions of βIII-tubulin protein and myelin protein zero, which are markers of axon regeneration and re-myelination, respectively. Toluidine blue staining revealed the re-myelinated fiber diameter to be larger at proximal sites and that the re-myelinated fiber number was increased at distal sites in GK-irradiated injured nerves as compared with non-irradiated injured nerves. These results suggest that GK irradiation of injured nerves facilitates regeneration and re-myelination. In a behavior study, early alleviation of allodynia was observed with GK irradiation in PSL rats. When GK-induced alleviation of allodynia was initially detected, the expression of glial cell line-derived neurotrophic factor (GDNF), a potent analgesic factor, was significantly increased by GK irradiation. These results suggested that GK irradiation alleviates allodynia via increased GDNF. This study provides novel evidence that GK irradiation of injured peripheral nerves may have beneficial effects.     

JNK1-Dependent Phosphorylation of GAP-43 Serine 142 is a Novel Molecular Marker for Axonal Growth

Mammalian axon growth has mechanistic similarities with axon regeneration. The growth cone is an important structure that is involved in both processes, and GAP-43 (growth associated protein-43 kDa) is believed to be the classical molecular marker. Previously, we used growth cone phosphoproteomics to demonstrate that S96 and T172 of GAP-43 in rodents are highly phosphorylated sites that are phosphorylated by c-jun N-terminal protein kinase (JNK). We also revealed that phosphorylated (p)S96 and pT172 antibodies recognize growing axons in the developing brain and regenerating axons in adult peripheral nerves. In rodents, S142 is another putative JNK-dependent phosphorylation site that is modified at a lower frequency than S96 and T172. Here, we characterized this site using a pS142-specific antibody. We confirmed that pS142 was detected by co-expressing mouse GAP-43 and JNK1. pS142 antibody labeled growth cones and growing axons in developing mouse neurons. pS142 was sustained until at least nine weeks after birth in mouse brains. The pS142 antibody could detect regenerating axons following sciatic nerve injury in adult mice. Comparison of amino acid sequences indicated that rodent S142 corresponds to human S151, which is predicted to be a substrate of the MAPK family, which includes JNK. Thus, we confirmed that the pS142 antibody recognized human phospho-GAP-43 using activated JNK1, and also that its immunostaining pattern in neurons differentiated from human induced pluripotent cells was similar to those observed in mice. These results indicate that the S142 residue is phosphorylated by JNK1 and that the pS142 antibody is a new candidate molecular marker for axonal growth in both rodents and human.

     

Genome-wide association study of idiopathic hypersomnia in a Japanese population

Sleep and Biological Rhythms - Idiopathic hypersomnia (IH) is a rare sleep disorder characterized by excessive daytime sleepiness, great difficulty upon awakening, and prolonged sleep time. In...     

Purified Human Synovium Mesenchymal Stem Cells as a Good Resource for Cartilage Regeneration

Mesenchymal stem cells (MSCs) have the ability to differentiate into a variety of lineages and to renew themselves without malignant changes, and thus hold potential for many clinical applications. However, it has not been well characterized how different the properties of MSCs are depending on the tissue source in which they resided. We previously reported a novel technique for the prospective MSC isolation from bone marrow, and revealed that a combination of cell surface markers (LNGFR and THY-1) allows the isolation of highly enriched MSC populations. In this study, we isolated LNGFR⁺ THY-1 ⁺ MSCs from synovium using flow cytometry. The results show that the synovium tissue contained a significantly larger percentage of LNGFR ⁺ THY-1 ⁺ MSCs. We examined the colony formation and differentiation abilities of bone marrow-derived MSCs (BM-MSCs) and synovium-derived MSCs (SYN-MSCs) isolated from the same patients. Both types of MSCs exhibited a marked propensity to differentiate into specific lineages. BM-MSCs were preferentially differentiated into bone, while in the SYN-MSC culture, enhanced adipogenic and chondrogenic differentiation was observed. These data suggest that the tissue from which MSCs are isolated should be tailored according to their intended clinical therapeutic application.     

Plasma cholesterol-lowering and transient liver dysfunction in mice lacking squalene synthase in the liver

Squalene synthase (SS) catalyzes the biosynthesis of squalene, the first specific intermediate in the cholesterol biosynthetic pathway. To test the feasibility of lowering plasma cholesterol by inhibiting hepatic SS, we generated mice in which SS is specifically knocked out in the liver (L-SSKO) using Cre-loxP technology. Hepatic SS activity of L-SSKO mice was reduced by >90%. In addition, cholesterol biosynthesis in the liver slices was almost eliminated. Although the hepatic squalene contents were markedly reduced in L-SSKO mice, the hepatic contents of cholesterol and its precursors distal to squalene were indistinguishable from those of control mice, indicating the presence of sufficient centripetal flow of cholesterol and/or its precursors from the extrahepatic tissues. L-SSKO mice showed a transient liver dysfunction with moderate hepatomegaly presumably secondary to increased farnesol production. In a fed state, the plasma total cholesterol and triglyceride were significantly reduced in L-SSKO mice, primarily owing to reduced hepatic VLDL secretion. In a fasted state, the hypolipidemic effect was lost. mRNA expression of liver X receptor α target genes was reduced, while that of sterol-regulatory element binding protein 2 target genes was increased. In conclusion, liver-specific ablation of SS inhibits hepatic cholesterol biosynthesis and induces hypolipidemia without increasing significant mortality.     

The decreased membrane fluidity of in vivo aged, human erythrocytes. A spin label study.

The decreased membrane fluidity of the in vivo aged, human erythrocytes is found, by monitoring the electron paramagnetic resonance (EPR) spectra of fatty acid spin labels incorporated into the membrane. In addition, the decreased cell sizes and the decreased cholesterol and phospholipids contents, without significant changes of the quantity of the membrane proteins, also the decrease of ATP and 2,3-diphosphoglycerate and the increase of ADP and AMP, in the aged cells, were observed. Further the functional impairments of the aged cells, i.e. the increased oxygen affinity and the decreased deformability, were shown. On the basis of these quantitative data, the alteration of the protein-lipid organization, due to decreased lipid/protein ratio, the modified protein-lipid interaction and/or the influences of the diminished ATP content, is suggested to contribute towards the decreased membrane fluidity of the in vivo aged erythrocytes.     

15-Deoxy-Δ-prostaglandin J2 enhanced the anti-tumor activity of camptothecin against renal cell carcinoma independently of topoisomerase-II and PPARγ pathways

Renal cell carcinoma (RCC) is chemoresistant cancer. Although several clinical trials were conducted to explore effective medications, the chemoresistance of RCC has not yet been conquered. An endogenous ligand for peroxisome proliferator-activated receptor-γ (PPARγ), 15-deoxy-Δ^12,14-prostaglandin J₂ (15d-PGJ₂), induces apoptosis in RCC. Here, we examined synergistic effects of several carcinostatics on the anti-tumor activity of 15d-PGJ₂ in Caki-2 cell line by MTT assay. A topoisomerase-I inhibitor, camptothecin (CPT), exhibited synergistically toxicity with 15d-PGJ₂, but neither 5-fluorouracil nor cisplatin did. The combination of 15d-PGJ₂ and a topoisomerase-II inhibitor, doxorubicine, did not cause synergistic cell growth inhibition. The synergistic effect of topoisomerase-I and II inhibitors was not also detected. A PPARγ antagonist, GW9662, did not prevent Caki-2 from undergoing 15d-PGJ₂-induced cytotoxicity. The treatment of CPT combined with 15d-PGJ₂ activated caspase-3 more than the separate treatment. These results suggest that 15d-PGJ₂ exhibited the anti-tumor activity synergistically with CPT independent of topoisomerase-II and PPARγ.