Profiles of lipid, protein and microRNA expression in exosomes derived from intestinal epithelial cells after ischemia-reperfusion injury in a cellular hypoxia model.

Intestinal ischemia-reperfusion injury leads to proinflammatory responses via gut-derived mediators, and accumulating evidence suggests that exosomes secreted by intestinal epithelial cells are involved in the development of systemic inflammation. Studies have reported changes in protein, lipid, and microRNA (miRNA) expression; however, considering the different experimental conditions, information on the relationships among these biomolecules remains insufficient. The aim of this study was to elucidate the multiple changes that simultaneously occur in exosomes after ischemic stimulation. Here, differentiated human intestinal Caco-2 cells were exposed to 95% air (normoxia group) or 5% O2 (hypoxia group) for 6 h. Cells in each group were subsequently incubated for 24 h in an atmosphere of 5% CO2 plus 95% air. The conditioned medium of each group was collected for isolating intestinal epithelial cell-derived exosomes. Together with proteome analyses, lipid analyses, and miRNA quantification, biological functional assays were performed using monocytic NF-κB reporter cells. Lipid metabolism-related protein expression was upregulated, miRNA levels were slightly altered, and unsaturated fatty acid-containing lysophosphatidylcholine concentration increased after hypoxia and reoxygenation injury; this suggested that the changes in exosomal components associated with ischemia-reperfusion injury activates inflammation, including the NF-κB pathway. This study elucidated the multiple changes that co-occur in exosomes after ischemic stimulation and partially clarified the mechanism underlying exosome-mediated inflammation after intestinal ischemic recanalization.

Hepatic phosphatidylcholine catabolism driven by PNPLA7 and PNPLA8 supplies endogenous choline to replenish the methionine cycle with methyl groups.

Choline supplies methyl groups for regeneration of methionine and the methyl donor S-adenosylmethionine in the liver. Here, we report that the catabolism of membrane phosphatidylcholine (PC) into water-soluble glycerophosphocholine (GPC) by the phospholipase/lysophospholipase PNPLA8-PNPLA7 axis enables endogenous choline stored in hepatic PC to be utilized in methyl metabolism. PNPLA7-deficient mice show marked decreases in hepatic GPC, choline, and several metabolites related to the methionine cycle, accompanied by various signs of methionine insufficiency, including growth retardation, hypoglycemia, hypolipidemia, increased energy consumption, reduced adiposity, increased fibroblast growth factor 21 (FGF21), and an altered histone/DNA methylation landscape. Moreover, PNPLA8-deficient mice recapitulate most of these phenotypes. In contrast to wild-type mice fed a methionine/choline-deficient diet, both knockout strains display decreased hepatic triglyceride, likely via reductions of lipogenesis and GPC-derived glycerol flux. Collectively, our findings highlight the biological importance of phospholipid catabolism driven by PNPLA8/PNPLA7 in methyl group flux and triglyceride synthesis in the liver.

Association of healthy eating literacy and resident status with energy, nutrients, and food consumption among lean and normal-weight female university students.

BACKGROUND & AIMS: This study aimed to describe the association of healthy eating literacy (HEL) with energy, nutrients, and food consumption in young women who had normal and lean weight at a Japanese university, considering their resident status. METHODS: Cross-sectional data from the Ochanomizu Health Study were used in this study. Participants answered a self-administered, two-part, anonymous survey in 2018 and 2019. A total of 203 female undergraduate students with lean and normal body mass index (BMI) were included in the analysis. Single and stepwise multiple linear regression analysis was used to examine the association of HEL and resident status with healthy food consumption, such as vegetables, fish, and shellfish. The dependent variables were HEL and resident status, and the covariates were age, BMI, and the total metabolic equivalents. RESULTS: The median (25th and 75th percentiles) age, BMI, and total HEL score were 20 (19, 21) years, 20.2 (18.9, 21.3) kg/m 2, and 18 (16, 20), respectively. Resident status and HEL were independently associated with vegetables, fish, and shellfish intake. Participants who had higher total HEL scores and lived in their family home consumed significantly more vegetables (ß = 0.17 and -0.34, p < 0.05) and fish and shellfish (ß = 0.24, -0.28, p < 0.001). CONCLUSION: This study provides an insight into the association between HEL and dietary consumption in young women with normal and lean BMI.

Mediating role of sensory differences in the relationship between autistic traits and internalizing problems.

BACKGROUND: Sensory differences are related to the autistic traits, and previous studies have shown a positive correlation between sensory differences and internalizing problems. In this study, we hypothesized that sensory differences and suffering due to sensory differences mediates the relationships between autistic traits and internalizing problems. METHODS: A total of 346 female Japanese university students completed questionnaires regarding their autistic traits, suffering due to sensory differences, and internalizing problems. Moreover, 114 participants completed a questionnaire related to sensory differences. RESULTS: Autistic traits were correlated with Low Registration and Sensation Avoiding. These sensory differences were also correlated with suffering due to sensory differences and internalizing problems. Moreover, path analysis indicated that the higher the suffering due to Low Registration and Sensation Avoiding was, the greater the internalizing problems in those who showed these sensory differences. CONCLUSIONS: Female university students with serious suffering due to sensory differences may need support in managing their suffering and internalizing problems. Further research will help suggest support that these people require, at school and elsewhere.

Group IVE cytosolic phospholipase A2 limits psoriatic inflammation by mobilizing the anti-inflammatory lipid N-acylethanolamine.

Psoriasis is an inflammatory disorder characterized by keratinocyte hyper-proliferation and Th17-type immune responses. However, the roles of bioactive lipids and the regulation of their biosynthesis in this chronic skin disease are not fully understood. Herein, we show that group IVE cytosolic phospholipase A2 (cPLA2 ε/PLA2G4E) plays a counterregulatory role against psoriatic inflammation by producing the anti-inflammatory lipid N-acylethanolamine (NAE). Lipidomics analysis of mouse skin revealed that NAE species and their precursors (N-acyl-phosphatidylethanolamine and glycerophospho-N-acylethanolamine) were robustly increased in parallel with the ongoing process of imiquimod (IMQ)-induced psoriasis, accompanied by a marked upregulation of cPLA2 ε in epidermal keratinocytes. Genetic deletion of cPLA2 ε exacerbated IMQ-induced ear swelling and psoriatic marker expression, with a dramatic reduction of NAE-related lipids in IMQ-treated, and even normal, skin. Stimulation of cultured human keratinocytes with psoriatic cytokines concomitantly increased PLA2G4E expression and NAE production, and supplementation with NAEs significantly attenuated the cytokine-induced upregulation of the psoriatic marker S100A9. Increased expression of cPLA2 ε was also evident in the epidermis of psoriatic patients. These findings reveal for the first time the in vivo role of cPLA2 ε, which is highly induced in the keratinocytes of the psoriatic skin, promotes the biosynthesis of NAE-related lipids, and contributes to limiting psoriatic inflammation.

Clinical and molecular features of 66 patients with musculocontractural Ehlers-Danlos syndrome caused by pathogenic variants in CHST14 (mcEDS-CHST14).

BACKGROUND: Musculocontractural Ehlers-Danlos syndrome is caused by biallelic loss-of-function variants in CHST14 (mcEDS-CHST14) or DSE (mcEDS-DSE). Although 48 patients in 33 families with mcEDS-CHST14 have been reported, the spectrum of pathogenic variants, accurate prevalence of various manifestations and detailed natural history have not been systematically investigated. METHODS: We collected detailed and comprehensive clinical and molecular information regarding previously reported and newly identified patients with mcEDS-CHST14 through international collaborations. RESULTS: Sixty-six patients in 48 families (33 males/females; 0-59 years), including 18 newly reported patients, were evaluated. Japanese was the predominant ethnicity (27 families), associated with three recurrent variants. No apparent genotype-phenotype correlation was noted. Specific craniofacial (large fontanelle with delayed closure, downslanting palpebral fissures and hypertelorism), skeletal (characteristic finger morphologies, joint hypermobility, multiple congenital contractures, progressive talipes deformities and recurrent joint dislocation), cutaneous (hyperextensibility, fine/acrogeria-like/wrinkling palmar creases and bruisability) and ocular (refractive errors) features were observed in most patients (>90%). Large subcutaneous haematomas, constipation, cryptorchidism, hypotonia and motor developmental delay were also common (>80%). Median ages at the initial episode of dislocation or large subcutaneous haematoma were both 6 years. Nine patients died; their median age was 12 years. Several features, including joint and skin characteristics (hypermobility/extensibility and fragility), were significantly more frequent in patients with mcEDS-CHST14 than in eight reported patients with mcEDS-DSE. CONCLUSION: This first international collaborative study of mcEDS-CHST14 demonstrated that the subtype represents a multisystem disorder with unique set of clinical phenotypes consisting of multiple malformations and progressive fragility-related manifestations; these require lifelong, multidisciplinary healthcare approaches.

Mast Cell-Specific Deletion of Group III Secreted Phospholipase A2 Impairs Mast Cell Maturation and Functions.

Tissue-resident mast cells (MCs) have important roles in IgE-associated and -independent allergic reactions. Although microenvironmental alterations in MC phenotypes affect the susceptibility to allergy, understanding of the regulation of MC maturation is still incomplete. We previously reported that group III secreted phospholipase A2 (sPLA2-III) released from immature MCs is functionally coupled with lipocalin-type prostaglandin D2 (PGD2) synthase in neighboring fibroblasts to supply a microenvironmental pool of PGD2, which in turn acts on the PGD2 receptor DP1 on MCs to promote their proper maturation. In the present study, we reevaluated the role of sPLA2-III in MCs using a newly generated MC-specific Pla2g3-deficient mouse strain. Mice lacking sPLA2-III specifically in MCs, like those lacking the enzyme in all tissues, had immature MCs and displayed reduced local and systemic anaphylactic responses. Furthermore, MC-specific Pla2g3-deficient mice, as well as MC-deficient KitW-sh mice reconstituted with MCs prepared from global Pla2g3-null mice, displayed a significant reduction in irritant contact dermatitis (ICD) and an aggravation of contact hypersensitivity (CHS). The increased CHS response by Pla2g3 deficiency depended at least partly on the reduced expression of hematopoietic PGD2 synthase and thereby reduced production of PGD2 due to immaturity of MCs. Overall, our present study has confirmed that MC-secreted sPLA2-III promotes MC maturation, thereby facilitating acute anaphylactic and ICD reactions and limiting delayed CHS response.

Erylysin A inhibits cytokinesis in Escherichia coli by binding with cardiolipin.

Cardiolipin (CL) localizes to curved membranes such as cristae in mitochondria as well as cell poles and division sites in rod-shaped bacteria. CL is believed to stabilize the membrane curvature by localizing to sites of negative curvature. However, this hypothesis has not been tested because of a lack of appropriate tools to distinguish CL inside and outside lipid bilayers. In this study, we provided the first evidence that CL localized to regions of negative curvature in Escherichia coli using the novel CL probe erylysin A-EGFP (EryA-EGFP). Staining in E.coli illustrated that CL localized to the inner leaflets at cell poles and the outer leaflets at division sites. Furthermore, we revealed that EryA-EGFP inhibited cytokinesis. We propose that cytokinesis completes after CL in the outer leaflets transfers to the inner leaflets at division sites by inspecting the mechanism of inhibition of cytokinesis. Moreover, the cytoskeletal protein RodZ was abnormally distributed when cytokinesis was inhibited by EryA-EGFP, suggesting that RodZ participates in cytokinesis. In summary, we revealed the detailed distribution of CL and proposed a new model of cytokinesis.

Later chronotype is associated with unhealthful plant-based diet quality in young Japanese women.

BACKGROUND: Having a late chronotype, that is, the tendency to go to sleep and wake up at later hours, influences an individual's physical and mental health. Despite a few studies noting the association of chronotype with healthy dietary patterns, this relationship remains unclear. PURPOSE: This study aimed to describe the association of chronotype with healthful and unhealthful plant-based diet quality in female Japanese undergraduate students. DESIGN: Cross-sectional. PARTICIPANTS AND SETTING: A total of 218 female university students in Tokyo, Japan. MAIN OUTCOME MEASURES: Healthful and unhealthful plant-based dietary index-Japanese version (hPDI-J and uPDI-J), calculated using the validated brief-type self-administered diet history questionnaire. STATISTICAL ANALYSES PERFORMED: A five-model stepwise multiple linear regression analysis was conducted. Independent variables were hPDI-J and uPDI-J scores, and dependent variables were various lifestyle habits related to the circadian rhythm and demographic characteristics. RESULTS: Mean (standard deviation) sleep duration, midpoint of sleep, sleep latency time, and social jetlag were 411 (60) min, 03:56 (00:57), 21 (27) min, and 50 (39) min, respectively. Chronotype and several variables, such as residential status, energy and alcohol intake, and nutritional knowledge, were associated with healthful and unhealthful plant-based diet quality. Individuals who had higher hPDI-J scores were more likely to have an earlier chronotype (ß = -0.168, P = 0.019) and better nutritional knowledge (ß = 0.164, P = 0.022) than those with lower hPDI-J scores. Individuals were more likely to have higher uPDI-J scores if they were living alone (ß = -0.301, P < 0.001), had a later chronotype (ß = 0.181, P = 0.001), higher frequency of snacking (ß = 0.164, P = 0.019), lower total energy (ß = -0.445, P < 0.001), and worse nutritional knowledge (ß = -0.172, P = 0.001). CONCLUSION: This study provided new evidence as to the relationship between sleep and dietary habits, the interaction of which may affect women's health.

Is mindful eating sustainable and healthy? A focus on nutritional intake, food consumption, and plant-based dietary patterns among lean and normal-weight female university students in Japan.

PURPOSE: This study aimed to investigate the correlation between mindful eating and nutritional intake, food consumption, and healthful and unhealthful plant-based dietary patterns in young Japanese women. METHODS: The sample comprised 215 female undergraduates who responded to a two-questionnaire anonymous survey conducted in Tokyo, Japan in 2018 and 2019 from November to December. We measured mindful eating status using the Expanded Mindful Eating Scale (EMES) and used Japanese plant-based dietary indices to determine plant-based dietary patterns. Partial correlation analyses were conducted to determine the correlation of mindful eating with energy and nutrient intake, food consumption, and plant-based dietary patterns, after adjusting for demographics and body mass index. RESULTS: Participants with higher sub-scores in "health of the planet" and "awareness and appreciation for food" ate higher quantities of several micronutrients and plant-based foods and were more likely to have a healthful plant-based dietary pattern. They were also less likely to have an unhealthful plant-based dietary pattern. In contrast, participants with higher scores in "non-judgmental awareness" ate less protein, whole grains, and vegetables, and were likely to have an unhealthful plant-based dietary pattern. CONCLUSION: This study is the first to show that young Japanese women with normal or lean body weight were more likely to consume healthful plant-based foods when they ate mindfully. LEVEL V: Opinions of respected authorities, based on descriptive studies, narrative reviews, clinical experience, or reports of expert committees.

Peroxisome proliferator-activated receptor α as a novel therapeutic target for schizophrenia.

BACKGROUND: The pathophysiology of schizophrenia, a major psychiatric disorder, remains elusive. In this study, the role of peroxisome proliferator-activated receptor (PPAR)/retinoid X receptor (RXR) families, belonging to the ligand-activated nuclear receptor superfamily, in schizophrenia, was analyzed. METHODS: The PPAR/RXR family genes were screened by exploiting molecular inversion probe (MIP)-based targeted next-generation sequencing (NGS) using the samples of 1,200 Japanese patients with schizophrenia. The results were compared with the whole-genome sequencing databases of the Japanese cohort (ToMMo) and the gnomAD. To reveal the relationship between PPAR/RXR dysfunction and schizophrenia, Ppara KO mice and fenofibrate (a clinically used PPARα agonist)-administered mice were assessed by performing behavioral, histological, and RNA-seq analyses. FINDINGS: Our findings indicate that c.209-2delA, His117Gln, Arg141Cys, and Arg226Trp of the PPARA gene are risk variants for schizophrenia. The c.209-2delA variant generated a premature termination codon. The three missense variants significantly decreased the activity of PPARα as a transcription factor in vitro. The Ppara KO mice exhibited schizophrenia-relevant phenotypes, including behavioral deficits and impaired synaptogenesis in the cerebral cortex. Oral administration of fenofibrate alleviated spine pathology induced by phencyclidine, an N-methyl-d-aspartate (NMDA) receptor antagonist. Furthermore, pre-treatment with fenofibrate suppressed the sensitivity of mice to another NMDA receptor antagonist, MK-801. RNA-seq analysis revealed that PPARα regulates the expression of synaptogenesis signaling pathway-related genes. INTERPRETATION: The findings of this study indicate that the mechanisms underlying schizophrenia pathogenesis involve PPARα-regulated transcriptional machinery and modulation of synapse physiology. Hence, PPARα can serve as a novel therapeutic target for schizophrenia.

The role of mesenteric lymph exosomal lipid mediators following intestinal ischemia-reperfusion injury on activation of inflammation.

BACKGROUND: Intestinal ischemia caused by hemorrhagic shock is known to induce systemic inflammatory responses. Previous studies have shown that mesenteric lymph (ML) plays a crucial role in gut-mediated inflammation. Lipid mediators, such as lysophosphatidylcholines (LPCs), which contain polyunsaturated fatty acids (PUFAs), are present in the postshock ML. Exosomes are also present in the ML and act as transcellular carriers of lipids; however, their role in postshock systemic inflammation has not been revealed. Here, we aimed to identify changes in lipid mediators in ML exosomes after intestinal ischemia. METHODS: Male Sprague-Dawley rats underwent laparotomy, followed by ML duct cannulation. Animals were subjected to 60 minutes of intestinal ischemia by superior mesenteric artery clamping, followed by 120 minutes of reperfusion. Mesenteric lymph was obtained before and after intestinal ischemia, and exosomes were isolated from ML by ultracentrifugation. The biological activity of ML exosomes was determined using the monocyte nuclear factor κB (NF-κB) activation assay. Lipids of ML exosomes were extracted and quantified by liquid chromatography/electrospray ionization mass spectrometry. RESULTS: Mesenteric lymph exosome-induced NF-κB activation significantly increased after intestinal ischemia, and lipid analysis revealed a significant increase in the concentration of PUFA-containing LPCs. In addition, PUFA-containing LPCs also induced NF-κB activation. CONCLUSION: Our results suggest that biologically active lipid mediators in ML exosomes may be involved in the inflammatory response after intestinal ischemia.

Development and validation of the Expanded Mindful Eating Scale.

PURPOSE: To develop and validate the Expanded Mindful Eating Scale (EMES), an expanded mindful eating model created for the promotion of health and sustainability. DESIGN/METHODOLOGY/APPROACH: A cross-sectional study using self-administered questionnaire surveys on Ochanomizu Health Study (OHS) was conducted. The survey was provided to 1,388 female university students in Tokyo, Japan. Exploratory factor analysis (EFA), confirmatory factor analysis (CFA) and a partial correlation analysis were used to confirm construct and criterion validity. Internal consistency of the EMES was confirmed to calculate Cronbach's alpha. FINDINGS: The response rate was 38.7 % (n = 537). Mean BMI was 20.21 ± 2.12, and 18.8% of them were classified as "lean" (BMI < 18.5). The authors listed 25 items and obtained a final factor structure of five factors and 20 items, as a result of EFA. Through CFA, the authors obtained the following fit indices for a final model: GFI = 0.914, AGFI = 0.890, CFI = 0.870 and RMSEA = 0.061. The total EMES score was significantly correlated with BMI, mindfulness, body dissatisfaction, drive for thinness and life satisfaction (r = -0.138, -0.315, -0.339, -0.281 and 0.149, p < 0.01, respectively). Cronbach's alpha for all items in this scale was 0.687. PRACTICAL IMPLICATIONS: The authors suggest the possibility that practitioners and researchers of mindful eating that includes this new concept can use authors' novel scale as an effective measurement tool. ORIGINALITY/VALUE: The EMES, which can multidimensionally measure the concept of the expanded model of mindful eating was first developed in this study.

2-Carba cyclic phosphatidic acid inhibits lipopolysaccharide-induced prostaglandin E2 production in a human macrophage cell line.

Cyclic phosphatidic acid (cPA) is a naturally occurring phospholipid mediator that contains a unique cyclic phosphate ring at the sn-2 and sn-3 positions of its glycerol backbone. Using mouse models for multiple sclerosis (cuprizone-induced demyelination and experimental autoimmune encephalomyelitis) and traumatic brain injury, we revealed that cPA and its metabolically stabilized cPA derivative, 2-carba-cPA (2ccPA), have potential to protect against neuroinflammation. In this study, we investigated whether 2ccPA has anti-inflammatory effect on peripheral immune function or not using inflammation-induced macrophages-like cell line, THP-1 monocytes differentiated by phorbol 12-myristate 13-acetate (PMA). Lipopolysaccharide (LPS)-stimulated THP-1 cells were found to have higher expression of the mRNAs of several inflammation-related cytokines and of the enzyme cyclooxygenase-2 (Cox-2); however, when THP-1 cells were stimulated by LPS in the presence of 2ccPA, the increase in the expression of pro-inflammatory cytokine and Cox-2 mRNA was attenuated. 2ccPA treatment also decreased the amount of prostaglandin E2 (PGE2) produced by LPS-stimulated THP-1 cells and decreased expression of the mRNA of prostaglandin E receptor 2 (EP2, PTGER2), a PGE2 receptor that mediates inflammation. These results indicate that 2ccPA has anti-inflammatory properties.

A Critical Review of the Consensus Statement from the European Atherosclerosis Society Consensus Panel 2017.

BACKGROUND: The Consensus Statement from the European Atherosclerosis Society (EAS) Consensus Panel 2017 concludes on the basis of 3 different types of clinical studies that low-density lipoprotein (LDL) causes atherosclerotic cardiovascular disease (ASCVD). In Mendelian randomization studies, rare genetic mutations affecting LDL receptor function were found to cause higher or lower LDL-C levels, which are associated with correspondingly altered ASCVD risk. In prospective cohort studies and randomized controlled trials (RCTs) of statins, a remarkably consistent log-linear association was demonstrated between the absolute magnitude of LDL-C exposure and ASCVD risk. The EAS Statement proposes that any mechanism of lowering plasma LDL concentration should reduce the risk of ASCVD events proportional to the absolute reduction in LDL-C and the cumulative duration of exposure to lower LDL-C. However, as we explain, we do not find this conclusion acceptable. SUMMARY: Our review points out that different interpretations are possible for the results of Mendelian randomization studies. As for prospective cohort studies, many inconsistent reports on the association of LDL-C and ASCVD were disregarded when drafting the Statement, reports with and without genetic factors related to LDL receptor function should be analyzed separately, and the term ASCVD in the Statement is used inappropriately because myocardial infarction and cerebral infarction differ in their association with LDL-C. As for RCTs, clinical reports on statins published before and after the implementation of new regulations affecting clinical trials (2004/2005) should not both be included in meta-analyses because the evaluated efficacy of statins changed markedly, and the irreversible adverse effects of statins need to be evaluated more rigorously now that their mechanisms have been elucidated. Key Messages: Apart from the EAS hypothesis that LDL causes ASCVD, recent pharmacological/biochemical studies, as summarized in this review and elsewhere, have revealed that atherosclerosis is caused by statins taken to lower LDL-C, as well as by warfarin and some types of vegetable fats and oils, in the absence of significantly elevated LDL-C levels. Thus, the promotion of statin treatment by the Statement is rather risky and we do not feel that the conclusions are justified for the prevention of ASCVD.

A novel sphingomyelin/cholesterol domain-specific probe reveals the dynamics of the membrane domains during virus release and in Niemann-Pick type C.

We identified a novel, nontoxic mushroom protein that specifically binds to a complex of sphingomyelin (SM), a major sphingolipid in mammalian cells, and cholesterol (Chol). The purified protein, termed nakanori, labeled cell surface domains in an SM- and Chol-dependent manner and decorated specific lipid domains that colocalized with inner leaflet small GTPase H-Ras, but not K-Ras. The use of nakanori as a lipid-domain-specific probe revealed altered distribution and dynamics of SM/Chol on the cell surface of Niemann-Pick type C fibroblasts, possibly explaining some of the disease phenotype. In addition, that nakanori treatment of epithelial cells after influenza virus infection potently inhibited virus release demonstrates the therapeutic value of targeting specific lipid domains for anti-viral treatment.-Makino, A., Abe, M., Ishitsuka, R., Murate, M., Kishimoto, T., Sakai, S., Hullin-Matsuda, F., Shimada, Y., Inaba, T., Miyatake, H., Tanaka, H., Kurahashi, A., Pack, C.-G., Kasai, R. S., Kubo, S., Schieber, N. L., Dohmae, N., Tochio, N., Hagiwara, K., Sasaki, Y., Aida, Y., Fujimori, F., Kigawa, T., Nishibori, K., Parton, R. G., Kusumi, A., Sako, Y., Anderluh, G., Yamashita, M., Kobayashi, T., Greimel, P., Kobayashi, T. A novel sphingomyelin/cholesterol domain-specific probe reveals the dynamics of the membrane domains during virus release and in Niemann-Pick type C.

Medicines and Vegetable Oils as Hidden Causes of Cardiovascular Disease and Diabetes.

BACKGROUND: Positive associations have been observed between cardiovascular disease (CVD) and type 2 diabetes mellitus (DM), but their causal relationship has not been clarified. Nevertheless, guidelines from relevant medical societies recommend using cholesterol lowering medication (statin) for both types of patients. Medicines with several different action mechanisms have been developed, and the effectiveness of different lifestyle modifications has been studied extensively for the prevention of DM, which was successful in improving clinical marker status in relatively short-term treatments, but none have been shown to be effective in improving long-term outcomes (mortality from CVD and all causes). SUMMARY: Statin-induced suppression of prenyl intermediates in the cholesterol biosynthetic pathway has been linked to stimulated atherosclerosis and heart failure. On the other hand, certain types of vegetable oil and hydrogenated oil shortened the survival of stroke-prone spontaneously hypertensive rats by decreasing platelet number, increasing hemorrhagic tendency and damaging kidney functions, which could not be accounted for by their fatty acid and phytosterol compositions. These vegetable oils and medicines such as statin and warfarin share, in part, a common mechanism to inhibit vitamin K2-dependent processes, which was interpreted to lead to increased onset of CVD, DM, chronic kidney disease, bone fracture and even mental disorder. Impaired vitamin K2-dependent processes by some types of vegetable oils and medicines, but not plasma high low density lipoprotein cholesterol, were proposed as the cause of CVD, DM and other lifestyle-related diseases. High n-6/n-3 fatty acid ratio of ingested foods, but not animal fats, was emphasized to be another risk factor for many of the diseases described above. KEY MESSAGES: To date, no randomized controlled trials (RCTs) have been performed to prove the above interpretation. However, the opposite types of RCT trials have been performed by increasing the intake of high-linoleic vegetable oils and reducing that of animal fats, which resulted in increased CVD and all-cause mortality. The amounts of these vegetable oils to exhibit adverse effects in animal studies are not huge (<6 energy %), which should not be overlooked nor disregarded.

Group X Secreted Phospholipase A2 Releases ω3 Polyunsaturated Fatty Acids, Suppresses Colitis, and Promotes Sperm Fertility.

Within the secreted phospholipase A2(sPLA2) family, group X sPLA2(sPLA2-X) has the highest capacity to hydrolyze cellular membranes and has long been thought to promote inflammation by releasing arachidonic acid, a precursor of pro-inflammatory eicosanoids. Unexpectedly, we found that transgenic mice globally overexpressing human sPLA2-X (PLA2G10-Tg) displayed striking immunosuppressive and lean phenotypes with lymphopenia and increased M2-like macrophages, accompanied by marked elevation of free ω3 polyunsaturated fatty acids (PUFAs) and their metabolites. Studies usingPla2g10-deficient mice revealed that endogenous sPLA2-X, which is highly expressed in the colon epithelium and spermatozoa, mobilized ω3 PUFAs or their metabolites to protect against dextran sulfate-induced colitis and to promote fertilization, respectively. In colitis, sPLA2-X deficiency increased colorectal expression of Th17 cytokines, and ω3 PUFAs attenuated their production by lamina propria cells partly through the fatty acid receptor GPR120. In comparison, cytosolic phospholipase A2(cPLA2α) protects from colitis by mobilizing ω6 arachidonic acid metabolites, including prostaglandin E2 Thus, our results underscore a previously unrecognized role of sPLA2-X as an ω3 PUFA mobilizerin vivo, segregated mobilization of ω3 and ω6 PUFA metabolites by sPLA2-X and cPLA2α, respectively, in protection against colitis, and the novel role of a particular sPLA2-X-driven PUFA in fertilization.

Novel role of group VIB Ca2+-independent phospholipase A2γ in leukocyte-endothelial cell interactions: An intravital microscopic study in rat mesentery.

BACKGROUND: Phospholipase A2 (PLA2) is associated with a variety of inflammatory processes related to polymorphonuclear neutrophil (PMN)-endothelial cell interactions. However, the cellular and molecular mechanisms underlying the interactions and the causative isoform(s) of PLA2 remain elusive. In addition, we recently showed that calcium-independent PLA2γ (iPLA2γ), but not cytosolic PLA2 (cPLA2), is responsible for the cytotoxic functions of human PMN including respiratory bursts, degranulation, and chemotaxis. We therefore hypothesized that iPLA2γ is a prerequisite for the PMN recruitment cascade into the site of inflammation. The aim of this study was to elucidate the roles of the three major phospholipases A2, iPLA2, cPLA2 and secretory PLA2, in leukocyte rolling and adherence and in the surface expression of ß2-integrins in vivo and in vitro in response to well-defined stimuli. METHODS: Male Wistar rats were pretreated with PLA2 inhibitors selective for iPLA2ß, iPLA2γ, cPLA2, or secretory PLA2. Leukocyte rolling/adherence in the mesenteric venules superfused with platelet-activating factor (PAF) were quantified by intravital microscopy. Furthermore, isolated human PMNs or whole blood were incubated with each PLA2 inhibitor and then activated with formyl-methionyl-leucyl-phenylalanine (fMLP) or PAF. PMN adherence was assessed by counting cells bound to purified fibrinogen, and the surface expression of lymphocyte function-associated antigen 1 and macrophage antigen 1 (Mac-1) was measured by flow cytometry. RESULTS: The iPLA2γ-specific inhibitor almost completely inhibited the fMLP/PAF-induced leukocyte adherence in vivo and in vitro and also decreased the fMLP/PAF-stimulated surface expression of Mac-1 by 60% and 95%, respectively. In contrast, the other inhibitors did not affect these cellular functions. CONCLUSION: iPLA2γ seems to be involved in leukocyte/PMN adherence in vivo and in vitro as well as in the up-regulation of Mac-1 in vitro in response to PAF/fMLP. This enzyme is therefore likely to be a major regulator in the PMN recruitment cascade.

Discrete roles of intracellular phospholipases A2 in human neutrophil cytotoxicity.

BACKGROUND: The role of calcium-independent phospholipase A2 (iPLA2), a component of the three major PLA2 families, in acute/chronic inflammatory processes remains elusive. Previous investigations have documented iPLA2-mediated respiratory burst of neutrophils (PMNs); however, the causative isoform of iPLA2 is unidentified. We also demonstrated that the iPLA2γ-specific inhibitor attenuates trauma/hemorrhagic shock-induced lung injury. Therefore, iPLA2γ may be implicated in acute inflammation. In addition, arachidonic acid (AA), which is primarily produced by cytosolic PLA2 (cPLA2), is known to display PMN cytotoxicity, although the relationship between AA and the cytotoxic function is still being debated on. We therefore hypothesized that iPLA2γ regulates PMN cytotoxicity via AA-independent signaling pathways. The study aim was to distinguish the role of intracellular phospholipases A2, iPLA2, and cPLA2, in human PMN cytotoxicity and explore the possibility of the presence of signaling molecule(s) other than AA. METHODS: Isolated human PMNs were incubated with the PLA2 inhibitor selective for iPLA2ß, iPLA2γ, or cPLA2 and then activated with formyl-methionyl-leucyl-phenylalanine (fMLP) or phorbol 12-myristate 13-acetate (PMA). Superoxide production was assayed according to the superoxide dismutase-inhibitable cytochrome c reduction method, and the degree of elastase release was measured using a p-nitroanilide-conjugated elastase-specific substrate. In addition, chemotaxis toward platelet activating factor/fMLP was determined with a modified Boyden chamber system. RESULTS: The iPLA2γ-specific inhibitor reduced the fMLP/PMA-stimulated superoxide generation by 90% and 30%, respectively; in addition, the inhibitor completely blocked the fMLP/PMA-activated elastase release. However, the cPLA2-specific inhibitor did not abrogate these effects to any degree at all concentrations. Likewise, the inhibitor for iPLA2γ, but not iPLA2ß or cPLA2, completely inhibited the platelet activating factor/fMLP-induced chemotaxis. CONCLUSION: iPLA2 is involved in extracellular reactive oxygen species production, elastase release, and chemotaxis in response to well-defined stimuli. In addition, the ineffectiveness of the cPLA2 inhibitor suggests that AA may not be relevant to these cytotoxic functions.