Altered ovarian tissue level of lysophosphatidic acid and mRNA expressions of its metabolic enzymes and receptors in rats received gonadotropin-hyperstimulation

Lysophosphatidic acid (LPA), a well-studied member of the lysophospholipid family, is known to exert an important bio-effect on oocyte maturation and ovulation in mammals. We attempted to determine how follicle maturation in the rat ovary affects the levels of LPA and its precursor lysophospholipids, as well as mRNA levels of LPA-producing and -degrading enzymes and LPA receptors in rats that received gonadotropin-hyper-stimulation. Tissue levels of lysophospholipids were quantified by LC-MS/MS, and relative mRNA expression levels of LPA-producing and -degrading enzymes, and LPA receptors were measured by RT-PCR. Tissue levels of n-6 polyunsaturated LPAs and LPCs were higher in the ovaries of rats after receiving human chorionic gonadotropin, unlike the distinct profiles of n-3 polyunsaturated LPAs, which had lower levels, and LPCs which had higher levels, after the gonadotropin treatment. The effects of different levels of other polyunsaturated lysophospholipids were variable: decreased levels of lysophosphatidylglycerol, and unaltered levels of lysophosphatidylethanolamine, lysophosphatidylinositol, and lysophosphatidylserine. The results indicate that expression of mRNA levels of autotaxin and acylglycerol kinase were reduced and expression of lipid phosphate phosphatase 3 was elevated, whereas expressions of two membrane phosphatidic acid phosphatases (A1α and A1β) and lipid phosphate phosphatase 1 were essentially unaltered in rat ovary at several stages after ovary hyperstimulation. After the gonadotropin treatment, the expression levels of all LPA receptors except LPA3 were decreased at various times. These results are discussed with respect to the physiological processes of the ovarian environment and development in rats.

Extracellular and intracellular productions of lysophosphatidic acids and cyclic phosphatidic acids by lysophospholipase D from exogenously added lysophosphatidylcholines to cultured NRK52E cells

Lysophosphatidic acid (LPA) is a bioactive lysophospholipid that is a notable biomarker of kidney injury. However, it is not clear how LPA is produced in renal cells. In this study, we explored LPA generation and its enzymatic pathway in a rat kidney-derived cell, NRK52E cells. Culturing of NRK52E cells with acyl lysophosphatidylcholine (acyl LPC), or lyso-platelet activating factor (lysoPAF, alkyl LPC) was resulted in increased extracellular level of choline, co-product with LPA by lysophospholipase D (lysoPLD). Their activities were enhanced by addition of calcium ions to the cell culture medium, but failed to be inhibited by S32826, an autotaxin (ATX)-specific inhibitor. Liquid chromatography-tandem mass spectrometric analysis revealed the small, but significant extracellular production of acyl LPA/cyclic phosphatidic acid (cPA) and alkyl LPA/cPA. The mRNA expression of glycerophosphodiesterase (GDE) 7 with lysoPLD activity was elevated in confluent NRK52E cells cultured over 3 days. GDE7 plasmid-transfection of NRK52E cells augmented both extracellular and intracellular productions of LPAs (acyl and alkyl) as well as extracellular productions of cPAs (acyl and alkyl) from exogenous LPCs (acyl and alkyl). These results suggest that intact NRK52E cells are able to produce choline and LPA/cPA from exogenous LPCs through the enzymatic action of GDE7 that is located on the plasma membranes and intracellular membranes.

Hypoxia increases cellular levels of phosphatidic acid and lysophospholipids in undifferentiated Caco-2 cells

Cancer cells are known to survive in a hypoxic microenvironment by altering their lipid metabolism as well as their energy metabolism. In this study, Caco-2 cells derived from human colon cancer, were found to have elevated intracellular levels of phosphatidic acid and its lysoform, lysophosphatidic acid (LPA), under hypoxic conditions. Our results suggested that the elevation of LPA in Caco-2 cells was mainly due to the combined increases in cellular levels of lysophosphatidylcholine and lysophosphatidylethanolamine by phospholipase A₂ and subsequent hydrolysis to LPA by lysophospholipase D. We detected the Ca²⁺ -stimulated choline-producing activities toward exogenous lysophosphatidylcholines in whole Caco-2 cell homogenates, indicating their involvement in the LPA production in intact Caco-2 cells.

Lysophosphatidic acid production from lysophosphatidylcholine by lysophospholipase D activity of autotaxin in plasma of women with normal and adverse pregnancies

To identify biomarker lipids causing preterm delivery, we focused on lysophosphatidylcholine (LPC) and lysophosphatidic acid (LPA). The results of liquid chromatography-tandem mass spectrometry revealed that plasma levels of LPCs and LPAs were higher in the first and third (T3) trimesters of human normal and adverse pregnancies than in the second trimester, suggesting the direct metabolic conversion of LPC to LPA by lysophospholipase D (lysoPLD) activity of autotaxin. The elevated LPC and LPA levels in women with preterm deliveries in T3 were higher than in women with term deliveries under normal pregnancy in T3. We measured lysoPLD activity of diluted sera of pregnant women by quantification of choline released from exogenous LPC, and found progressive increases of lysoPLD activities in women with normal and adverse pregnancies. Ratios of lysoPLD activities for linoleoyl LPC to that for palmitoyl LPC were found to be decreased in pregnant women compared to that in non-pregnant women. These results may be due to the altered patterns of endogenous modulators for autotaxin and the profiles of the bound metal ion.

Reaction Mechanism and Selectivity Control of Si Compound ALE Based on Plasma Modification and F-Radical Exposure

In this work, atomic layer etching (ALE) of Si compounds using H₂ or N₂ plasma modification followed by fluorine radical exposure is discussed. It is shown that the H₂ plasma modification process promotes the selective etching of SiN, SiC, and SiCO versus SiO₂. The N₂ plasma modification, on the other hand, enables the selective etching of SiC and SiCO versus SiN and SiO₂. The origin of the etching selectivity between different Si compounds is investigated using a combination of in situ SE and FTIR supported by several ex situ analysis techniques. It is shown that the formation of a hydrogen-rich layer after plasma modification is essential to enable the ALE process. The hydrogen-rich layer can be formed due to ion and radicals of the modification plasma (H₂ plasma modification) or be a result of the reconfiguration of hydrogen that is already present in the film (N₂ plasma modification). The obtained insights are expected to further enhance the etching selectivity of Si compound ALE processes. Furthermore, it is anticipated that the process can be extended to many other compound materials such as Ti and Hf, as well as enable selective etching between their oxides, carbides, and nitrides.

Altered plasma levels of lysophospholipids in response to adrenalectomy of rats

The aim of this study was to investigate effects of reduced stress hormone by adrenalectomy on rat plasma levels of lysophosphatidic acid (LPA) and other lysophospholipids. We measured activities of lysophospholipase D (lysoPLD) in plasma and lipid phosphate phosphatase (LPP) in blood by determining choline and inorganic phosphate, respectively. LPA, lysophosphatidylcholine (LPC), lysophosphatidylethanolamine (LPE), lysophosphatidylinositol (LPI), lysophosphatidylserine (LPS) and lysophosphatodylglycerol were quantified by LC-MS/MS. In adrenalectomized rats, plasma levels of LPA, LPE, LPS and LPI, but not LPC, were increased. The increased level of LPA were due to decreased LPC level, increases plasma activity of lysoPLD toward LPC and decreased LPP activity toward LPA. Daily injections of deoxycoricosterone into rats selectively reversed increased level of LPS. Our results suggest enzymatic mechanism for increased plasma level of LPA, and indicate that the circulating levels of lysophospholipids including LPA in rats are differently affected by artificial suppression of release of adrenergic hormones.

Synthesis and In Vitro Assessment of pH-Sensitive Human Serum Albumin Conjugates of Pirarubicin

In a previous study, we reported on the development of a synthetic polymer conjugate of pirarubicin (THP) that was formed via an acid-labile hydrazone bond between the polymer and the THP. However, the synthetic polymer itself was non-biodegradable, which could lead to unexpected adverse effects. Human serum albumin (HSA), which has a high biocompatibility and good biodegradability, is also a potent carrier for delivering antitumor drugs. The objective of this study was to develop pH-sensitive HSA conjugates of THP (HSA-THP), and investigate the release of THP and the cytotoxicity under acidic conditions in vitro for further clinical development. HSA-THP was synthesized by conjugating maleimide hydrazone derivatives of THP with poly-thiolated HSA using 2-iminothiolane, via a thiol-maleimide coupling reaction. We synthesized two types of HSA-THP that contained different amounts of THP (HSA-THP2 and HSA-THP4). Free THP was released from both of the HSA conjugates more rapidly at an acidic pH, and the rates of release for HSA-THP2 and HSA-THP4 were similar. Moreover, both HSA-THPs exhibited a higher cytotoxicity at acidic pH than at neutral pH, which is consistent with the effective liberation of free THP under acidic conditions. These findings suggest that these types of HSA-THPs are promising candidates for further development.

Identification of human glycerophosphodiesterase 3 as an ecto phospholipase C that converts the G protein-coupled receptor 55 agonist lysophosphatidylinositol to bioactive monoacylglycerols in cultured mammalian cells

A family of glycerol-based lysolipid mediators comprises lysophosphatidic acid as a representative phospholipidic member but also a monoacylglycerol as a non-phosphorus-containing member. These critical lysolipid mediators are known to be produced from different lysophospholipids by actions of lysophospholipases C and D in mammals. Some members of the glycerophosphodiesterase (GDE) family have attracted recent attention due to their phospholipid-metabolizing activity. In this study, we found selective depletion of lysophosphatidylinositol among lysophospholipids in the culture medium of COS-7 cells transfected with a vector containing glycerophosphodiester phosphodiesterase 2 (GDPD2, GDE3). Thin-layer chromatography and liquid chromatography-tandem mass spectrometry of lipids extracted from GDE3-transfected COS-7 cells exposed to fluorescent analogs of phosphatidylinositol (PI) revealed that GDE3 acted as an ecto-type lysophospholipase C preferring endogenous lysophosphatidylinositol and PI having a long-chain acyl and a short-chain acyl group rather than endogenous PI and its fluorescent analog having two long chain acyl groups. In MC3T3-E1 cells cultured with an osteogenic or mitogenic medium, mRNA expression of GDE3 was increased by culturing in 10% fetal bovine serum for several days, concomitant with increased activity of ecto-lysophospholipase C, converting arachidonoyl-lysophosphatidylinositol, a physiological agonist of G protein-coupled receptor 55, to arachidonoylglycerol, a physiological agonist of cannabinoid receptors 1 and 2. We suggest that GDE3 acts as an ecto-lysophospholipase C, by switching signaling from lysophosphatidylinositol to that from arachidonoylglycerol in an opposite direction in mouse bone remodeling.

Distinct contributions of two choline-producing enzymatic activities to lysophosphatidic acid production in human amniotic fluid from pregnant women in the second trimester and after parturition

The purpose of this study was to clarify whether human amniotic fluid (AF) contains a significant level of bioactive lysophosphatidic acid (LPA) and, whether autotaxin (ATX) is involved in the production of LPA, if present. Using LC-MS/MS, we found a higher ratio of levels of LPA and its precursor lysophosphatidylcholine (LPC) in AF collected after parturition than that in AF collected at the middle stage of pregnancy. We detected significant choline-producing enzymatic activity toward an exogenous LPC in AF at the middle stage of pregnancy, about half of which was ascribable to ATX. In AF collected after parturition, the ATX-independent choline-producing activity of glycerophosphcholine phosphodiesterase coupled to lysophospholipase A activity was increased in relative to the lysophospholipase D activity of ATX. These results suggest that the increased LPA/LPC ratio in AF at the term of pregnancy was due to not only a moderate increase in the level of LPC, but also an unknown mechanism involving epithelial cells bathed with AF.

A low level of lysophosphatidic acid in human gingival crevicular fluid from patients with periodontitis due to high soluble lysophospholipase activity: Its potential protective role on alveolar bone loss by periodontitis

We previously detected a submicromolar concentration of lysophosphatidic acid (LPA) in human saliva. Here, we compare LPA concentrations in human gingival crevicular fluid (GCF) from patients with periodontitis and healthy controls, and examine how the local LPA levels are regulated enzymatically. The concentrations of LPA and its precursor lysophospholipids in GCF was measured by liquid chromatography-tandem mass spectrometry. The LPA-producing and LPA-degrading enzymatic activities were measured by quantifying the liberated choline and free fatty acid, respectively. The concentration of LPA in GCF of periodontitis patients was lower than that of healthy controls, due to higher soluble lysophospholipase activity toward LPA. LPA was found to prevent survival of Sa3, a human gingival epithelium-derived tumor cell line, activate Sa3 through Ca²⁺ mobilization, and release interleukin 6 from Sa3 in vitro. Furthermore, local injection of LPA into the gingiva attenuated ligature-induced experimental alveolar bone loss induced by oral bacteria inoculation in a rat model of periodontitis in vivo. A high concentration of LPA in human GCF is necessary to maintain normal gingival epithelial integrity and function, protecting the progression of periodontitis.

Effect of Systematic Conversion to Generic Mycophenolate Mofetil (MMF) in Kidney Transplantation: A Single-Center Clinical Experience from Japan

INTRODUCTION

Recently, more and more generic drugs have been used for immunosuppressive drugs in the field of organ transplantation. Some reports have indicated that blood concentration of most generic drugs is difficult to maintain stability, and it may cause the difference in graft survival of transplanted organs between original drugs and generic drugs. In this article, we report the cases could not maintain blood concentration of generic drugs of mycophenolate mofetil (MMF).

RESULTS

In 4 cases out of 5 cases that we had to change original MMF to generic MMF, there were cases that blood concentration level was not stabilized. There were possibility that the lowered blood concentration level of MMF caused a rejection, in two cases. Mean MMF trough level was decreased from 3.6 ± 1.9 μg/mL to 0.6 ± 0.4 μg/mL. Due to the early detection, it did not become severe or failure of graft function, however, we cannot deny the possibilities that side effects were increased and rejection rose. In these cases, we discontinued to use the generic drugs thereafter due to unstable plasma concentration of MMF.

DISCUSSION

Some reports have indicated that failure to maintain plasma concentration of MMF leads to rejection. Therefore, maintenance of effective plasma concentration and prevention of rejection are essential to long-term graft survival in kidney transplant.

CONCLUSION

Generic drug formulations may exhibit differences in effects and absorption compared to the brand-name drug. If the generic drug should be used, patients should be closely monitored.

Addition of high load of lysophosphatidic acid to standard and high-fat chows causes no significant changes of its circulating and peripheral tissue levels but affects body weight and visceral fat mass of mice

Oral administration of lysophosphatidic acid (LPA), a critical intercellular lipid mediator, exerts wound healing and antiulcer effects on gastrointestinal system. To evaluate effects of food-derived LPA on body homeostasis, we measured LPA levels by liquid chromatography-tandem mass spectrometry in chows, feces, plasma, liver, and visceral fat of mice fed a normal or high-fat chow supplemented with or without LPA-rich soybean phospholipids for 30 days. Reductions in daily body weight gains and visceral fat mass were mainly related to lower chow intake by mice fed the LPA-rich high-fat chow, whereas reduced body weight gains and fat mass were mainly related to decreased intestinal triacylglycerol absorption in mice fed LPA-rich chow. Our results showed no significant increase in plasma, liver, or adipose LPA levels, even if a quite high LPA concentration (2.0%) in chows was ingested daily, suggesting limited effects of food-derived LPA on the lumen side of the digestive tract. © 2018 BioFactors, 44(6):548-557, 2018.

Safety of Elderly Living Kidney Donors: 2 Cases of Donors Older Than 80 Years: A Case Report

Much controversy exists over the performance of elderly living donor kidney transplantation. We report the safety of 2 cases of elderly living kidney donations in our hospital. CASE 1: An 82-year-old man was a living kidney donor for his 56-year-old son. The donor suffered from hypertension, but has successfully managed his blood pressure with only one medication. His serum creatinine was 0.7 mg/dL and inulin clearance was 122.5 mL/min, which met the usual criteria for living kidney donors. This was his son's secondary kidney transplantation, and no other donors existed. CASE 2: An 80-year-old woman was a living kidney donor for her 45-year-old son. Her serum creatinine was 0.61 mg/dL and inulin clearance was 71.7 mL/min, which met the marginal kidney donor criteria. In both cases, we determined that the donor kidney function was acceptable. Though we explained the risks of the transplantation thoroughly, the patients' strong will to offer a kidney to their family member did not change. We decided to carry out the transplantation. At the time of publication, nearly 2 years have passed since the transplantation, but both donors and recipients are doing well. In the future, it seems more likely that the number of elderly living donor kidney transplantation will rise. On one hand, there is no absolute contraindication for elderly donors, while on the other hand, the criteria for a living kidney donor must be strictly examined. Furthermore, careful observation of both donors and recipients after transplantation is required.

Peripheral tissue levels and molecular species compositions of N-acyl-phosphatidylethanolamine and its metabolites in mice lacking N-acyl-phosphatidylethanolamine-specific phospholipase D

N-acylethanolamines (NAEs), a class of lipid mediators, are produced from N-acyl-phosphatidylethanolamine (NAPE) by several pathways, including the direct release by NAPE-specific phospholipase D (NAPE-PLD) or the multistep pathway via sn-glycero-3-phospho-N-acylethanolamine (Gp-NAE). Using liquid chromatography-tandem mass spectrometry, we compared peripheral tissue levels of NAPE, Gp-NAE and NAE in NAPE-PLD-deficient (NAPE-PLD-/-) and wild type (WT) mice. NAPE-PLD was suggested to play a major role in the NAPE degradation in heart, kidney, and liver, but not in jejunum, because the NAPE levels except jejunum were significantly higher in NAPE-PLD-/- mice than in WT mice. The deletion of NAPE-PLD failed to alter the NAE levels of these tissues, suggesting its limited role in the NAE production. The enzyme assays with tissue homogenates confirmed the presence of NAPE-PLD-independent pathways in these peripheral tissues. Gp-NAE species having an acyl moiety with 22 carbons and 6 double bonds was enriched in these peripheral tissues. As for sn-2 acyl species of NAPE, 18:2-acyl-containing NAPE species were predominant over 18:1-containing species in heart, liver, and jejunum. Our results show that both molecular species composition of NAPE, NAE and Gp-NAE and their dependencies on Napepld are different among the peripheral tissues, suggesting that each tissue has distinct metabolic pathways and these NAE-containing lipids play tissue-specific roles.

Daily Intake of High-Fat Diet with Lysophosphatidic Acid-Rich Soybean Phospholipids Augments Colon Tumorigenesis in Kyoto Apc Delta Rats

BACKGROUND

Oral administration of lysophosphatidic acid (LPA) was shown to attenuate gastric ulceration in rats and mice but aggravate intestinal tumorigenesis in mice.

AIMS

The present study examined whether dietary LPA induces or prevents development of colorectal tumor in rats.

METHODS

Kyoto Apc Delta rats fed high-fat diet with or without an LPA-rich soybean phospholipid mixture (LSP, 0.1 or 1%) were treated with azoxymethane and dextran sodium sulfate to induce colorectal tumorigenesis. Rats were killed 15 weeks after azoxymethane treatment, and size, total number, location, and severity of colorectal tumors were assessed. Expression of mRNA of LPA receptors in rat colon tissue was assayed.

RESULTS

Rats fed the diet supplemented with 1% LSP had a higher number of tumors 2-4 mm long compared than those with or without 0.1% LSP. The mean distance of tumors >4 mm long from the anus was significantly higher than those of tumors <2 and 2-4 mm long in rats fed 1% LSP-supplemented diet. Supplementation of the diet with 0.1% LSP decreased mRNA expression of LPA5 in colon tumors of rats.

CONCLUSIONS

Dietary supplementation of LPA-rich phospholipids dose-dependently augmented colorectal tumorigenesis. Decreased expression of LPA5 in colon tumors may be relevant to augmented tumorigenesis.

Reduced rat plasma lysophosphatidylglycerol or lysophosphatidic acid level as a biomarker of aristolochic acid-induced renal and adipose dysfunctions

AIMS

Food products and diet pills containing aristolochic acid (AA) are responsible for a rapid progression of nephropathy associated with reduced body weight in human beings. In this study, we investigated the relationship of dietary NaCl and lysophospholipid (LPL) plasma levels to body weight gain in AA-treated rats.

MAIN METHODS

Male rats receiving a salt-deficient chow, normal salt chow or high salt chow were injected intraperitoneally daily with AA for 15days. Body weight, visceral fat mass, food intake, levels of LPL in plasma and its synthesized enzyme were investigated.

KEY FINDINGS

Body weight gain, visceral fat mass and daily food intake were smaller in AA-treated rats than those of control rats, regardless of dietary salt concentration. AA treatment decreased plasma levels of major lysophosphatidic acid (LPA) molecular species in rats fed the normal or high-salt chow but not the salt-deficient chow, whereas both the plasma lysophospholipase D activity and kidney mRNA level of autotaxin of AA-treated rats fed chow with defined salt concentrations were lower than those of control rats. Plasma levels of major molecular species of lysophosphatidylglycerol (LPG) in AA-treated rat groups fed chow with defined salt concentrations were lower than those of control rats.

SIGNIFICANCE

Plasma levels of LPG and LPA seem to be relevant to the reduced body weight gain and fat mass due to AA treatment.

The role of plasma chemistry on functional silicon nitride film properties deposited at low-temperature by mixing two frequency powers using PECVD

A correlation study of plasma parameters and film properties and the implication of dual frequency PECVD for industry are proposed.

Reduced kidney levels of lysophosphatidic acids in rats after chronic administration of aristolochic acid: Its possible protective role in renal fibrosis

Aristolochic acid (AA) is considered to be a causative agent for progressive interstitial renal fibrosis, leading to AA nephropathy. Lysophosphatidic acid (LPA) is a mediator in the onset of renal fibrosis. In this study, we analyzed the molecular species of LPA and its precursor lysophospholipids in kidney tissue from rats exposed to AA. Daily intraperitoneal injections of AA for 35 days to rats gave rise to fibrosis in kidney, decreased the kidney levels of LPA, lysophosphatidylserine and lysophosphatidylinositol. In rat renal cell lines (NRK52E and NRK49F), AA-induced cytotoxicity was potentiated by Ki16425, LPA_1,3 receptor antagonist. The level of mRNA encording α-smooth muscle actin was significantly increased by AA-treatment only in NRK52E cells, while the mRNA level of collagen III was decreased in both NRK52E and NRK49F cells. These results suggest that endogenous LPA in rat kidney prevents AA-induced renal fibrosis.

The potential protective role of lysophospholipid mediators in nephrotoxicity induced by chronically exposed cadmium

Cadmium is a hazardous metal whose chronic exposure induces renal failure due to fibrosis, but the mechanisms are not well known. In this study we analyzed the molecular species of lysophosphatidic acid (LPA) and related phospholipids, together with their metabolic enzyme activity, in plasma from Wistar rats exposed up to 300ppm Cd(2+) in drinking water for 114days. Exposure of 300ppm Cd(2+) for 114days enhanced autotoxin (ATX)/lysophospholipase D activity, but significantly lowered the total levels of LPA and lysophosphatidylethanolamine. Interestingly, the total level of sphingosine-1-phosphate (S1P) was elevated dose-dependently by Cd(2+). Cultured rat kidney-derived interstitial fibroblast cells, NRK49F cells and proximal epithelial cells, NRK52E cells, were both responsive to the protective action of LPA or S1P against Cd(2+) toxicity. The former cell expresses ATX RNA. In conclusion, the elevation of LPA-producing enzyme activity and S1P concentrations in plasma after exposure of rats to Cd(2+) would protect from the renal toxicity of Cd(2+).

Hyperocclusion Up-regulates CCL3 Expression in CCL2- and CCR2-deficient Mice

Excessive mechanical stress (MS) during hyperocclusion is known to result in disappearance of the alveolar hard line, enlargement of the periodontal ligament (PDL) space, and destruction of alveolar bone, leading to occlusal traumatism. We have recently reported that MS induces predominantly C-C chemokine ligand (CCL) 2 expression in PDL tissues, leading, via C-C chemokine receptor (CCR) 2, to MS-dependent osteoclastogenesis in alveolar bone. Thus, we hypothesize that ablation of the CCL2/CCR2 signaling pathway should suppress MS-induced osteoclastogenesis-associated chemokines and alleviate occlusal traumatism. We examined the effect of MS on chemokine expression and osteoclastogenesis using in vivo and in vitro hyperocclusion models with CCL2-deficient (CCL2(-/-)) and CCR2-deficient (CCR2(-/-)) mice. Compared with that in wild-type mice, expression of CCL3 in PDL cells and TRAP-positive cells in alveolar bone from CCL2(-/-) and CCR2(-/-) mice was up-regulated, even in the absence of MS. Furthermore, the expression of CCL3 and TRAP-positive cells was significantly increased after both 4 and 7 days of hyperocclusal MS loading in CCL2(-/-) and CCR2(-/-) mice. Hyperocclusion induced compensatory CCL3 expression and promoted osteoclastogenesis to counterbalance deficient CCL2/CCR2 signaling, suggesting that co-expression of CCL3 with CCL2 may precipitate synergistic, MS-dependent alveolar bone destruction during occlusal traumatism. Abbreviations: MS, mechanical stress; PDL, periodontal ligament; CCL2, CC chemokine ligand 2 (MCP-1; monocyte chemoattractant protein-1); CCR2, CC chemokine receptor 2; CCL3, CC chemokine ligand 3 (MIP-1α); CCL5, CC chemokine ligand 5 (RANTES).

Lysophospholipids and lysophospholipase D in rabbit aqueous humor following corneal injury

We previously found that lysophosphatidic acid (LPA)-like activity eliciting Cl(-) currents in Xenopus oocytes is increased in rabbit aqueous humor (AH) following corneal freeze wounds. The purpose of this study was to examine whether actual levels of LPA in AH from wounded eyes are higher than those from control eyes, and to determine the sources and enzymatic pathways of AH LPA in control and wounded conditions. Lysophospholipase D (lysoPLD) activity was measured by the enzymatic determination of choline following incubation of AH samples with exogenous lysophosphatidylcholines (LPCs). The molecular species compositions of LPA and LPC in fresh and incubated AH were determined by liquid chromatography-tandem mass spectrometry. A high, but similar activity of lysoPLD in the samples from both control and freeze-wounded eyes was detected. Its enzymatic properties resemble those of plasma lysoPLD, identified as autotaxin. Levels of LPCs, predominant substrates of lysoPLD in AH, were several times higher in the AH samples from injured eyes than those from the control eyes. Our results suggest that lysoPLD is constitutively released from corneal tissues and/or ciliary body into the AH, with no injury-induced increase in release following freeze-wounding. They also suggest that wound-induced increases in LPA-like biological activity are due to linoleoyl species-rich molecular composition in AH from wounded eyes. A possible mechanism of the altered molecular composition is an increase in the AH concentrations of LPCs, linoleoyl species of which are preferentially converted to corresponding unsaturated LPA by the constitutively active lysoPLD.

Characteristics of maximum performance of pedaling exercise in recumbent and supine positions

To determine the characteristics of maximum pedaling performance in the recumbent and supine positions, maximum isokinetic leg muscle strength was measured in eight healthy male subjects during pedaling at three velocities (300°/s, 480°/s, and 660°/s), and maximum incremental tests were performed for each position. The maximum isokinetic muscle strength in the recumbent position was 210.0 ± 29.2 Nm at 300°/s, 158.4 ± 19.8 Nm at 480°/s, and 110.6 ± 13.2 at 660°/s. In contrast, the muscle strength in the supine position was 229.3 ± 36.7 Nm at 300°/s, 180. 7 ± 20.3 Nm at 480°/s, and 129.6 ± 14.0 Nm at 660°/s. Thus, the maximum isokinetic muscle strength showed significantly higher values in the supine position than in the recumbent position at all angular velocities. The knee and hip joint angles were measured at peak torque using a goniometer; the knee joint angle was not significantly different between both positions, whereas the hip joint angle was greater in the supine position than in the recumbent position (Supine position: 137.3 ± 9. 33 degree at 300°/s, 140.0 ± 11.13 degrees at 480°/s, and 141.0 ± 9.61 degrees at 660°/s. Recumbent position: 99.5 ± 12.21 degrees at 300°/s, 101.6 ± 12.29 degrees at 480°/s, and 105.8 ± 14.28 degrees at 660°/s). Peak oxygen uptake was higher in the recumbent position (50.3 ± 4.43 ml·kg(-1)·min(-1)) than in the supine position (48.7 ± 5.10 ml·kg(-1)·min(-1)). At maximum exertion, the heart rate and whole-body rate of perceived exertion (RPE) were unaffected by position, but leg muscle RPE was higher in the supine position (19.5 ± 0.53 than in the recumbent position (18.8 ± 0.71). These results suggest that the supine position is more suitable for muscle strength exertion than the recumbent position, and this may be due to different hip joint angles between the positions. On the contrary, the endurance capacity was higher in the recumbent position than in the supine position. Since leg muscle RPE was higher in the supine position than in the recumbent position, it was suggested that different burdens imposed on active muscles in both positions exerted an impact on the result of the endurance capacity. Key pointsIsokinetic maximal peak torque measured in this study during pedaling showed higher values in the supine position than in the recumbent position at all angular velocities.Maximum oxygen uptake as evaluated by maximum incremental testing showed higher values in the recumbent position than in the supine position.No significant changes in the angle of peak torque for the knee joint or hip joint were observed in either the recumbent or supine position even at an increased angular velocity. These observations indicate the effectiveness of a cycle-type muscle strength assessment device for evaluating leg muscle strength.

Comparison of lysophospholipid levels in rat feces with those in a standard chow

Although lysophospholipids have attracted much attention due to their diverse physiological activities through their specific receptors, little is known about their metabolic fates in mammalian digestive systems after their ingestion as a minor food component. In this study, we analyzed five lysophospholipids in lipid extracts of a standard rat chow and feces of rats fed the chow by two-dimensional thin layer chromatography and liquid chromatography-tandem mass spectrometry. The most abundant lysophospholipid in the rat chow was lysophosphatidylcholine followed by lysophosphatidylethanolamine, lysophosphatidic acid (LPA), lysophosphatidylinositol and lysophosphatidylserine (LPS) in an increasing order, but their concentrations were very low in rat feces. Among the molecular species of LPS in the chow, only saturated species were detected in the feces in significant amounts. In addition, several molecular species of LPA remained in the feces in variable portions (saturated > monounsaturated > polyunsaturated). These results suggest that a portion of ingested LPA and LPS reach the rat large intestine, affecting physiological colon functions.

Hyperocclusion Stimulates Osteoclastogenesis via CCL2 Expression

Excessive mechanical stress (MS) during hyperocclusion is known to result in disappearance of the alveolar hard line, enlargement of the periodontal ligament (PDL) space, and destruction of alveolar bone, leading to occlusal traumatism. We hypothesized that MS induces expression of osteoclastogenesis-associated chemokines in PDL tissue, resulting in chemotaxis and osteoclastogenesis during occlusal traumatism. We examined the effect of MS on relationships between chemokine expression and osteoclastogenesis using in vivo and in vitro hyperocclusion models. In an in vitro model, intermittent stretching-induced MS was shown to up-regulate the expression of CC chemokine ligand (CCL)2, CCL3, and CCL5 in PDL cells. The expression levels of CCL2 in PDL tissues, its receptor CCR2 in pre-osteoclasts, and tartrate-resistant acid-phosphatase-positive cells in alveolar bone were significantly up-regulated 4-7 days after excessive MS during hyperocclusion in in vivo rodent models. Hyperocclusion predominantly induced CCL2 expression in PDL tissues and promoted chemotaxis and osteoclastogenesis, leading to MS-dependent alveolar bone destruction during occlusal traumatism. Abbreviations: MS, mechanical stress; PDL, periodontal ligament; CCL2, CC chemokine ligand 2; MCP-1, monocyte chemoattractant protein-1; CCR2, CC chemokine receptor 2; CCL3, CC chemokine ligand 3 (MIP-1α); CCL5, CC chemokine ligand 5 (RANTES); CXCL12, CXC chemokine ligand 12 (SDF-1).

Hexabromocyclododecane determination in seafood samples collected from Japanese coastal areas

The levels of three hexabromocyclododecane (HBCD) isomers and ΣHBCDs in 54 wild and 11 farmed seafood samples collected from four regions of Japan were determined by LC/MS/MS. For the fish classified as Anguilliformes, Perciformes, Clupeiformes and farmed Salmoniformes, the medians (ranges) of ΣHBCDs are 2.09 (0.05-36.9), 0.75 (ND-26.2), 0.12 (0.09-77.3) and 1.29 (1.09-1.34) ng g(-1)ww, respectively. However, HBCDs were not detected in samples classified as Crustacea, Mollusca, Pleuronectiformes and Scorpaeniformes, or if detected, the levels were very low. The rank correlation between ΣHBCDs (or α-HBCD) and fat content could not be found except for the Japanese sea bass of the Tohoku region. In HBCD isomer profiles, for fish samples above 20 ng g(-1)ww, the trend was found that γ-HBCD was predominant, which suggests the influence of discharge from a nearby industrial plant. In the other wild fish and the farmed fish samples, on the other hand, α-HBCD was mostly predominant, which suggests biomagnification via the food chain. Additionally, to assess the risk to human health, based on the determined HBCD median concentrations for Anguilliformes, farmed Salmoniformes and Perciformes, the daily intake of HBCDs from fish by an average Japanese adult was tentatively calculated to be 3.7, 2.3 and 1.3 ng (kg body weight)(-1) d(-1), respectively.

Involvement of adhesion molecule in in vitro plaque-like formation of macrophages stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide

BACKGROUND AND OBJECTIVE

Inflammatory agents, such as lipopolysaccharide (LPS), in periodontal pockets may promote atherogenesis by activating leukocytes. In our previous study, we developed a microchannel chip to observe the cell adhesion process in a fluid system. The objective of this investigation was to examine the mechanism by which periodontopathic bacterial LPS enhances plaque-like formation on a microchannel chip.

MATERIAL AND METHODS

To evaluate the effect of Aggregatibacter actinomycetemcomitans LPS on the expression of adhesion molecules, e.g. intercellular adhesion molecule 1 (ICAM-1), lymphocyte function-associated antigen 1 (LFA-1) and L-selectin, on the surface of murine macrophage RAW264.7 cells, the expression of each adhesion molecule was examined by flow cytometry and western blot analysis. Moreover, a flow test on the microchannel chip involving anti-adhesion molecule antibodies was conducted to clarify which adhesion molecule is related to plaque-like formation of RAW264.7 cells.

RESULTS

The expressions of ICAM-1 and LFA-1 on the surface of RAW 264.7 cells increased following 12 h culture with LPS; L-selectin expression was unaffected. An increase in ICAM-1 expression was also confirmed by western blot analysis. The flow test revealed that anti-ICAM-1 antibody inhibited plaque-like formation of LPS-stimulated macrophages on the micropillars of the microchannel chip.

CONCLUSION

These findings indicate that ICAM-1 plays an important role in plaque-like formation of LPS-stimulated macrophages. Our microchannel chip is a suitable tool for the investigation of etiological factors of atherosclerosis, including periodontitis, in vitro.

Eicosapentaenoic acid inhibits voltage-gated sodium channels and invasiveness in prostate cancer cells

BACKGROUND AND PURPOSE

The voltage-gated Na(+) channels (Na(v)) and their corresponding current (I(Na)) are involved in several cellular processes, crucial to metastasis of cancer cells. We investigated the effects of eicosapentaenoic (EPA), an omega-3 polyunsaturated fatty acid, on I(Na) and metastatic functions (cell proliferation, endocytosis and invasion) in human and rat prostate cancer cell lines (PC-3 and Mat-LyLu cells).

EXPERIMENTAL APPROACH

The whole-cell voltage clamp technique and conventional/quantitative real-time reverse transcriptase polymerase chain reaction analysis were used. The presence of Na(v) proteins was shown by immunohistochemical methods. Alterations in the fatty acid composition of phospholipids after treatment with EPA and metastatic functions were also examined.

KEY RESULTS

A transient inward Na(+) current (I(Na)), highly sensitive to tetrodotoxin, and Na(V) proteins were found in these cells. Expression of Na(V)1.6 and Na(V)1.7 transcripts (SCN8A and SCN9A) was predominant in PC-3 cells, while Na(V)1.7 transcript (SCN9A) was the major component in Mat-LyLu cells. Tetrodotoxin or synthetic small interfering RNA targeted for SCN8A and SCN9A inhibited metastatic functions (endocytosis and invasion), but failed to inhibit proliferation in PC-3 cells. Exposure to EPA produced a rapid and concentration-dependent suppression of I(Na). In cells chronically treated (up to 72h) with EPA, the EPA content of cell lipids increased time-dependently, while arachidonic acid content decreased. Treatment of PC-3 cells with EPA decreased levels of mRNA for SCN9A and SCN8A, cell proliferation, invasion and endocytosis.

CONCLUSION AND IMPLICATIONS

Treatment with EPA inhibited I(Na) directly and also indirectly, by down-regulation of Na(v) mRNA expression in prostate cancer cells, thus inhibiting their metastatic potential.

Vesicular acetylcholine transporter–immunoreactive axon terminals enriched in the pontine nuclei of the mouse

Information to the cerebellum enters via many afferent sources collectively known as precerebellar nuclei. We investigated the distribution of cholinergic terminal-like structures in the mouse precerebellar nuclei by immunohistochemistry for vesicular acetylcholine transporter (VAChT). VAChT is involved in acetylcholine transport into synaptic vesicles and is regarded as a reliable marker for cholinergic terminals and preterminal axons. In adult male mice, brains were perfusion-fixed. Polyclonal antibodies for VAChT, immunoglobulin G-peroxidase and diaminobenzidine were used for immunostaining. In the mouse brain, immunoreactivity was seen in almost all major cholinergic cell groups including brainstem motoneurons. In precerebellar nuclei, the signal could be detected as diffusely beaded terminal-like structures. It was seen heaviest in the pontine nuclei and moderate in the pontine reticulotegmental nucleus; however, it was seen less in the medial solitary nucleus, red nucleus, lateral reticular nucleus, inferior olivary nucleus, external cuneate nucleus and vestibular nuclear complex. In particular, VAChT-immunoreactive varicose fibers were so dense in the pontine nuclei that detailed distribution was studied using three-dimensional reconstruction of the pontine nuclei. VAChT-like immunoreactivity clustered predominantly in the medial and ventral regions suggesting a unique regional difference of the cholinergic input. Electron microscopic observation in the pontine nuclei disclosed ultrastructural features of VAChT-immunoreactive varicosities. The labeled bouton makes a symmetrical synapse with unlabeled dendrites and contains pleomorphic synaptic vesicles. To clarify the neurons of origin of VAChT-immunoreactive terminals, VAChT immunostaining combined with wheat germ agglutinin-conjugated horseradish peroxidase retrograde labeling was conducted by injecting a retrograde tracer into the right pontine nuclei. Double-labeled neurons were seen bilaterally in the laterodorsal tegmental nucleus and pedunculopontine tegmental nucleus. It is assumed that mesopontine cholinergic neurons negatively regulate neocortico-ponto-cerebellar projections at the level of pontine nuclei.

Movement of monoglyceride derived from hydrolysis of fluorescence-labeled lyso platelet-activating factor by lysophospholipase C through plasma membranes of porcine kidney epithelial cell line LLC-PK1

To investigate the mechanisms of the release of lyso platelet-activating factor (PAF), an alkyl ether-linked lysophosphatidylcholine, from the kidney epithelial cell line LLC-PK1, the cell monolayer was incubated with a fluorescence-labeled lysoPAF analog, Bodipy-lysoPAF, on either the basolateral or apical side. The fluorescent lipids in the culture media mixed with or without bovine serum albumin at a final concentration of 2% were analyzed by thin layer chromatography. In both cases, two major bands, assignable to Bodipy-lysoPAF and Bodipy-monoglyceride (MG), were detected in the culture medium to which Bodipy-lysoPAF had been added, whereas the culture medium at the opposite side exhibited only the major band of Bodipy-MG. Our results suggest that lysoPAF was degraded by high ecto-lysophospholipase C activity. The possible physiological significance of this metabolic pathway is discussed.

Intracranial angiosarcoma arising from a schwannoma

Angiosarcomas rarely arise from schwannomas, but we describe here a case of angiosarcoma that arose from a remnant of a benign vestibular schwannoma that had been removed 10 years earlier. The patient was a 66-year-old man with no sign of neurofibromatosis. Although we attempted surgical resection, we could not totally remove the tumour. The patient died nine months after diagnosis, primarily as result of an abscess in the cerebellum and base of the skull. The histological diagnosis was confirmed by the immunohistochemical findings of positivity for CD34 antigen and S-100 protein in the resected tumour.A review of the literature revealed four other cases of angiosarcoma with schwannoma, all of which arose from an extracranial nerve. The present case is the first report of an angiosarcoma with schwannoma arising from an intracranial locus.

A case of IgG4-related autoimmune disease with multiple organ involvement

A 52-year-old male was admitted with autoimmune pancreatitis (AIP), showing mononuclear cell infiltration in both the pancreas and salivary glands with both normal sialography and anti-SS-A/SS-B antibodies. Although the AIP improved with glucocorticoid treatment, subsequent abdominal computed tomography (CT) revealed a nodular shadow in the bilateral kidneys, which was confirmed as interstitial nephritis by renal biopsy. The patient's serum immunoglobulin G4 (IgG4) level was 10 times higher than the upper limit of the normal range. IgG4-positive mononuclear cell infiltration was detected in the salivary gland, pancreas, and kidney. A new entity proposed as 'IgG4-related autoimmune disease' was considered.

Transient electrostatic fields and related energetic proton generation with a plasma fiber

We observe a hollow structure and a fine ring in the proton images from a petawatt scale laser interaction with a "cone-fiber" target. The protons related to the hollow structure are accelerated from the cone-tip surface and deflected later by a radial electric field surrounding the fiber. Those associated with the fine ring are accelerated from the fiber surface by this radial electric field. This field is found to decay exponentially within 3 ps from about 5 x 10(12) V/m. Two-dimensional particle-in-cell simulations produce similar proton angular distributions.

Demonstration of bulk acceleration of ions in ultraintense laser interactions with low-density foams

Ion acceleration inside low-density foams irradiated by ultraintense laser pulses has been studied experimentally and theoretically. It is found that the ion generation is closely correlated with the suppressed hot electron transport inside the foams. Particle-in-cell simulations suggest that localized electrostatic fields with multi peaks around the surfaces of lamellar layers inside the foams are induced. These fields inhibit hot electron transport and meanwhile accelerate ions inside the foams, forming a bulk acceleration in contrast to the surface acceleration at the front and rear sides of a thin solid target.

Enhancement of energetic electrons and protons by cone guiding of laser light

Energetic electrons and protons are observed when a target consisting of a reentrant cone with a disk at the tip is irradiated by a petawatt (PW) laser at an intensity of approximately 10(19) W cm(-2). The angular distribution of the electrons and protons, dependent on the open angle of the reentrant cone, is found to differ from that in the case when a target with planar geometry is used. Two jet beams are observed, in directions parallel to the cone axis and normal to the cone-shaped wall. The number and cutoff energies of the generated protons are also related to the open angle of the cone. The efficiency of the generation of energetic electrons from the cone target is 2-3 times higher than that from a simple plane target. These results indicate a guiding of the PW laser beam in the cone geometry.

High-energy electrons produced in subpicosecond laser-plasma interactions from subrelativistic laser intensities to relativistic intensities

The characteristics of the forward hot electrons produced by subpicosecond laser-plasma interactions are studied for different laser polarizations at laser intensities from subrelativistic to relativistic. The peak of the hot electron beam produced by p-polarized laser beam shifts to the laser propagation direction from the target normal direction as the laser intensity reaches the relativistic. For s-polarized laser pulse, hot electrons are mainly directed to the laser axis direction. The temperature and the maximum energy of hot electrons are much higher than that expected by the empirical scaling law. The energy spectra of the hot electrons evolve to be a single-temperature structure at relativistic laser intensities from the two-temperature structure at subrelativistic intensities. For relativistic laser intensities, the forward hot electrons are less dependent on the laser polarization under the laser conditions. The existing of a preplasma formed by the laser amplified spontaneous emission pedestal plays an important role in the interaction. One-dimensional particle-in-cell simulations reproduce the most characteristics observed in the experiment.

Phorbol myristate acetate stimulates degradation of a structural analogue of platelet-activating factor to a neutral lipid in human leukemic K562 cells: relevance to the release of lipids

In our attempt to investigate the mechanism of the release of platelet-activating factor (PAF) from cells, the erythroleukemic cell line K562 was preloaded with a radiolabeled PAF analogue having an ethylcarbamyl residue, 1-O-octadecyl-2-O-ethylcarbamyl-sn-glycero-3-phosphocholine (ethylcarbamyl-PAF), that is resistant to the hydrolytic action of PAF acetylhydrolase. Its extracellular release was monitored using an albumin back-extraction method, and its metabolic degradation was analyzed by TLC. Phorbol myristate acetate (PMA) was found to stimulate the release of two radioactive lipids, ethylcarbamyl-PAF itself and its metabolite, 1-O-octadecyl-2-ethylcarbamyl-sn-glycerol, whereas only ethylcarbamyl-PAF was released from the resting cells. The increased release of radioactive lipids in PMA-stimulated cells was suggested to be due to stimulated degradation of intracellular ethylcarbamyl-PAF into the cell-permeable metabolite. Thus K562 cells have much less capacity to release intact PAF-like lipid in comparison with its high ability to uptake exogenously added PAF analogues previously described by us and others.

Novel CAG/CTG repeat expansion mutations do not contribute to the genetic risk for most cases of bipolar disorder or schizophrenia

The possible presence of anticipation in bipolar affective disorder and schizophrenia has led to the hypothesis that repeat expansion mutations could contribute to the genetic etiology of these diseases. Using the repeat expansion detection (RED) assay, we have systematically examined genomic DNA from 100 unrelated probands with schizophrenia and 68 unrelated probands with bipolar affective disorder for the presence of CAG/CTG repeat expansions. Our results show that 28% of the probands with schizophrenia and 30% of probands with bipolar disorder have a CAG/CTG repeat in the expanded range, but that each expansion could be explained by one of three nonpathogenic repeat expansions known to exist in the general population. We conclude that novel CAG/CTG repeat expansions are not a common genetic risk factor for bipolar disorder or schizophrenia.

Effect of the neurotoxic dose of methamphetamine on gene expression of parkin and Pael-receptors in rat striatum

We previously reported that haloperidol, a dopamine-D(2) receptor antagonist, induced striatal expression of parkin gene, which mutations cause autosomal recessive juvenile parkinsonism. Because of an involvement of the parkin gene defect in selective degeneration of dopaminergic neurons, we herein examined the effect of the neurotoxic dose of methamphetamine (METH; 40 mg/kg, i.p.) on gene expression of parkin and its substrate Pael-receptor (R) in the dopamine-rich areas of the rat brain, using reverse transcription-polymerase chain reaction. parkin mRNA levels in the striatum, but not in other regions, decreased at 1 and 2 h and returned to the pre-drug basal levels at 4 h after METH administration. METH also decreased Pael-R mRNA levels in the striatum and substantia nigra within 2 h after METH, while haloperidol (2 mg/kg, s.c.) increased Pael-R mRNA levels in the substantia nigra at 2 h after administration. These results suggest that temporary suppression of gene expression of parkin and Pael-R may be associated with the METH-induced dopaminergic neurotoxicity. Taken together with our previous report, dopaminergic modulation of the expression of parkin and Pael-R genes in the nigro-striatal pathway may have significant implication for pathophysiology and treatment of parkinson disease.

Anxiety induced by repetitive transcranial magnetic stimulation is suppressed by chronic treatment of paroxetine in rats

Repetitive transcranial magnetic stimulation (rTMS) has been shown to have a therapeutic effect on affective disorder and anxiety disorders. However, some reports have linked rTMS to a significant increase in anxiety in normal volunteers. This study investigates the effect of rTMS on anxiety and the use of acute and chronic paroxetine treatment on this animal model of anxiety. In normal rats, rTMS for 10 days induced anxiety, as shown by elevated plus maze, black and white box, and conditioned fear tests. This anxiety was suppressed by chronic, but not acute, paroxetine. These results suggest that rats receiving chronic rTMS treatment can be used as a model of anxiety and that the anxiety induced by rTMS might involve the serotonergic system.