Maternal and Neonatal Polyunsaturated Fatty Acid Intake and Risk of Neurodevelopmental Impairment in Premature Infants.

The N3 and N6 long chain polyunsaturated fatty acids (LCPUFA) docosahexaenoic acid (DHA) and arachidonic acid (AA) are essential for proper neurodevelopment in early life. These fatty acids are passed from mother to infant via the placenta, accreting into fetal tissues such as brain and adipose tissue. Placental transfer of LCPUFA is highest in the final trimester, but this transfer is abruptly severed with premature birth. As such, efforts have been made to supplement the post-natal feed of premature infants with LCPUFA to improve neurodevelopmental outcomes. This narrative review analyzes the current body of evidence pertinent to neurodevelopmental outcomes after LCPUFA supplementation in prematurely born infants, which was identified via the reference lists of systematic and narrative reviews and PubMed search engine results. This review finds that, while the evidence is weakened by heterogeneity, it may be seen that feed comprising 0.3% DHA and 0.6% AA is associated with more positive neurodevelopmental outcomes than LCPUFA-deplete feed. While no new RCTs have been performed since the most recent Cochrane meta-analysis in 2016, this narrative review provides a wider commentary; the wider effects of LCPUFA supplementation in prematurely born infants, the physiology of LCPUFA accretion into preterm tissues, and the physiological effects of LCPUFA that affect neurodevelopment. We also discuss the roles of maternal LCPUFA status as a modifiable factor affecting the risk of preterm birth and infant neurodevelopmental outcomes. To better understand the role of LCPUFAs in infant neurodevelopment, future study designs must consider absolute and relative availabilities of all LCPUFA species and incorporate the LCPUFA status of both mother and infant in pre- and postnatal periods.

Dietary fatty acids modulate cortisol concentrations and social dominance during social confrontations in adolescent male guinea pigs.

The hypothalamic-pituitary-adrenal (HPA)-axis and related glucocorticoid concentrations regulate physiology and behavior, which can be modulated by nutritional conditions, particularly by the dietary fatty acid composition. Omega-3 polyunsaturated fatty acids (PUFAs) have been shown to promote hypothalamic-pituitary-adrenal (HPA)-axis functions, whereas saturated fatty acids (SFAs) in general produce adverse effects and even increase baseline glucocorticoid concentrations. Glucocorticoids (e.g. cortisol) were further documented to modulate the establishment of dominance relationships, while the involvement of dietary fatty acids remains understudied. This study focused on different effects of PUFAs and SFAs on cortisol concentrations and social dominance in male guinea pigs. Three groups of animals were maintained on diets high in PUFAs (10 % w/w walnut oil), SFAs (10 % w/w coconut fat), or on an untreated control diet starting already prenatally. During adolescence, at an age of 60, 90, and 120 days, each individual's saliva cortisol concentrations and hierarchy index (calculated by initiated and received agonistic behavior) were measured during basal group housing conditions and stressful social confrontations with unfamiliar individuals of the other groups. SFA males showed highest baseline cortisol concentrations, lowest cortisol responses to social confrontations, and became subdominant. PUFA and control males showed significant cortisol responses. However, while control males became dominant during social confrontations, the hierarchy index in PUFA males decreased with age. Individual hierarchy indices during consecutive social confrontations revealed a high consistency. The findings presented here indicate that dietary fatty acids differently affect HPA-axis functions and social dominance but the underlying mechanisms remain to be determined.

Bovine pyruvate carboxylase gene proximal promoter activity is regulated by saturated and unsaturated fatty acids in Madin-Darby bovine kidney cells.

An increase in bovine pyruvate carboxylase (PC; EC 6.4.1.1) at calving and during feed restriction corresponds with increased circulating nonesterified fatty acids as a consequence of negative energy balance. Regulation of PC mRNA and effect of specific combinations of saturated and unsaturated fatty acid profiles has yet to be explored. Our objective was to determine the effects of chain length, degree of saturation, and copresence of saturated and unsaturated fatty acids on activity of bovine PC promoter 1 (PCP1). For these experiments, Madin-Darby bovine kidney cells were transfected with a full-length bovine PCP1 construct from -1002 to +3 bp relative to the bovine PC gene transcription start site (bovine PCP1(-1002_+3)) ligated to a Firefly luciferase reporter, or with one of a series of nested 5' serial truncations (bovine PCP1(-773_+3), bovine PCP1(-494_+3), or bovine PCP1(-222_+3)). Cells were exposed for 23 h to either individual fatty acids (C16:0, C18:0, or C18:3n-3 cis) bound to BSA or to fatty acid mixtures in ratios of 90:10, 75:25, 50:50, or 25:75, corresponding to combinations of C16:0: C18:3n-3 cis or C18:0: C18:3n-3 cis. Total fatty acid concentration was 1.00 mM. Exposure to either C16:0 or C18:3n-3 cis alone elicited a significant increase in capacity to drive bovine PCP1(-1002_+3) activity compared with 1% BSA in Dulbecco's Modified Eagle's Medium control treatment (2.29, 2.89, and 1.00 ± 0.26 fold of promoter induction for C16:0, C18:3n-3 cis, and control, respectively). Treatment with C18:3n-3 cis alone caused a greater increase in promoter activity compared with C16:0 alone, indicating a lesser response to C16:0 alone for bovine PCP1(-1002_+3). Interestingly, inclusion of C18:3n-3 cis, at any level of fatty acid ratios examined, in combination with C16:0 increased promoter activity of bovine PCP1(-773_+3) or bovine PCP1(-222_+3) compared with treatment with C16:0 alone or control. Data from the bovine PCP1 truncation and fatty acid copresence experiments reveal the potential for response elements of unsaturated fatty acids or fatty acid ligands in several bovine PCP1 promoter regions. In silico analysis of bovine PCP1 identified putative peroxisome proliferator-activated receptor α and sterol regulatory element binding protein binding sites which may be implicated in fatty acid signaling to alter bovine PCP1 activity. Pyruvate carboxylase promoter 1 activity that is mediated by unsaturated fatty acids acting through elements within -1002 and -222 bp of bovine PCPI may determine PC response during periods of negative energy balance in dairy cows.

Analysis of the effects of polyunsaturated fatty acids on transporter expressions using a PCR array: Induction of xCT/SLC7A11 in human placental BeWo cells.

OBJECTIVE: Polyunsaturated fatty acids (PUFAs), including arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), are essential for adequate fetal growth. The aim of the present study was to elucidate the effects of PUFAs on the expression and function of placental transporters, which play important roles in placental functions including the supply of nutrients to the fetus, excretion of metabolites, and protection of the fetus from xenobiotics. METHODS: Human placental choriocarcinoma BeWo cells were used as a trophoblast model. PUFA-induced alteration in the gene expression of 84 transporters was investigated by a commercially available PCR array. Protein levels and the activity of transporters were assessed by western blotting and uptake experiments, respectively. The placental expression of the transporters was analyzed using pregnant Wistar rats. RESULTS: PUFAs (AA, EPA, and DHA) increased cystine/glutamate transporter xCT/SLC7A11, which mediates the cellular uptake of cystine coupled with the efflux of glutamate in human placental choriocarcinoma BeWo cells. These PUFAs also increased [14C]-cystine uptake in BeWo cells. PUFA-induced xCT/SLC7A11 mRNA expression was not blocked by nuclear factor-erythroid 2-related factor-2 (NRF2) knockdown. Reverse transcription (RT)-PCR analysis indicated that xCT/Slc7a11 mRNA was detected in rat placenta and the expression level at gestational day (GD) 12 was higher than that at GD 20. CONCLUSION: These results indicate that PUFAs promoted cystine uptake in placental cells by inducing xCT/SLC7A11 expression and NRF2 did not contribute to upregulation of xCT/SLC7A11 by PUFAs. Furthermore, xCT expression in rat placenta may change during pregnancy.

Long-Chain Polyunsaturated Fatty Acids in the Green Microalga Lobosphaera incisa Contribute to Tolerance to Abiotic Stresses.

Lobosphaera incisa is a green microalga that accumulates high levels of the valuable omega-6 long-chain polyunsaturated fatty acids (LC-PUFA) arachidonic acid (ARA, 20:4n-6) in triacylglycerols (TAG) under nitrogen (N) starvation. LC-PUFA accumulation is a rare trait in photosynthetic microalgae with insufficiently understood physiological significance. In this study, RNAi was attempted, for the first time in L. incisa, to produce knockdown lines for the Δ5 desaturase gene. Two lines, termed modified lines, which were isolated during screening for transgenic events, demonstrated alterations in their LC-PUFA profile, ARA-biosynthesis gene expression and lipid class distribution. In line M5-78, which appeared to carry a mutation in the Δ6 elongase gene, LC-PUFA were substituted by 18:3n-6 in all glycerolipids. Line M2-35, for which the exact genetic background has not been established, displayed a dramatic reduction in 20:4n-6, concomitant with an augmented proportion of 18:1n-9, in particular in the extraplastidial membrane lipids and TAG. The physiological responses of the modified lines to stressful conditions were compared with the wild type and the Δ5 desaturase mutant. In the N-replete cells of modified lines, the frequency of lipid droplets was reduced, while a number of starch grains increased, suggesting altered partitioning of assimilated carbon into reserve products. Furthermore, both lines exhibited reduced ability to accumulate TAG under N deprivation and recover from N starvation. Both lines demonstrated lower photosynthetic pigment contents, impairments in photosynthesis under a range of stressful conditions, and less efficient functioning of photoprotection under optimal conditions. Possible implications of fatty acids modifications in the stress response of L. incisa are addressed.

12-Oxo-Phytodienoic Acid Acts as a Regulator of Maize Defense against Corn Leaf Aphid.

The corn leaf aphid (CLA; Rhopalosiphum maidis) is a phloem sap-sucking insect that attacks many cereal crops, including maize (Zea mays). We previously showed that the maize inbred line Mp708, which was developed by classical plant breeding, provides enhanced resistance to CLA. Here, using electrophysiological monitoring of aphid feeding behavior, we demonstrate that Mp708 provides phloem-mediated resistance to CLA. Furthermore, feeding by CLA on Mp708 plants enhanced callose deposition, a potential defense mechanism utilized by plants to limit aphid feeding and subsequent colonization. In maize, benzoxazinoids (BX) or BX-derived metabolites contribute to enhanced callose deposition by providing heightened resistance to CLA. However, BX and BX-derived metabolites were not significantly altered in CLA-infested Mp708 plants, indicating BX-independent defense against CLA. Evidence presented here suggests that the constitutively higher levels of 12-oxo-phytodienoic acid (OPDA) in Mp708 plants contributed to enhanced callose accumulation and heightened CLA resistance. OPDA enhanced the expression of ethylene biosynthesis and receptor genes, and the synergistic interactions of OPDA and CLA feeding significantly induced the expression of the transcripts encoding Maize insect resistance1-Cysteine Protease, a key defensive protein against insect pests, in Mp708 plants. Furthermore, exogenous application of OPDA on maize jasmonic acid-deficient plants caused enhanced callose accumulation and heightened resistance to CLA, suggesting that the OPDA-mediated resistance to CLA is independent of the jasmonic acid pathway. We further demonstrate that the signaling function of OPDA, rather than a direct toxic effect, contributes to enhanced CLA resistance in Mp708.

Dynamic differences in dietary polyunsaturated fatty acid metabolism in sputum of COPD patients and controls.

INTRODUCTION: Disturbances in onset and resolution of inflammation in chronic obstructive pulmonary disease (COPD) are incompletely understood. Dietary polyunsaturated fatty acids (PUFAs) can be converted into lipid mediators here collectively named oxylipins. These include classical eicosanoids, but also pro-resolving mediators. A balanced production of pro-inflammatory and pro-resolving oxylipins is of importance for adequate inflammatory responses and subsequent return to homeostasis. OBJECTIVES: Here we investigated if PUFA metabolism is disturbed in COPD patients. METHODS: Free PUFA and oxylipin levels were measured in induced sputum samples from the Bergen COPD cohort and COPD exacerbation study using liquid chromatography-mass spectrometry. Additionally, effects of whole cigarette smoke on PUFA metabolism in air-liquid interface cultures of primary bronchial epithelial cells were assessed. RESULTS: Significantly lower levels of free alpha-linolenic acid, linoleic acid and eicosapentaenoic acid (EPA) were detected in sputum from stable COPD patients compared to controls. During acute exacerbation (AE), levels of free arachidonic acid and docosapentaenoic acid were higher than in stable COPD patients. Furthermore, levels of omega-3 EPA- and docosahexaenoic acid-derived oxylipins were lower in sputum from stable COPD patients compared to controls. Cyclooxygenase-2-converted mediators were mostly increased during AE. In vitro studies additionally showed that cigarette smoke exposure may also directly contribute to altered epithelial PUFA metabolism, and indirectly by causing airway epithelial remodelling. CONCLUSIONS: Our findings show significant differences in PUFA metabolism in COPD patients compared to controls, further changed during AE. Airway epithelial remodelling may contribute to these changes. These findings provide new insight in impaired inflammatory resolution in COPD.

Free fatty acid receptor 4-ß-arrestin 2 pathway mediates the effects of different classes of unsaturated fatty acids in osteoclasts and osteoblasts.

Bone is a dynamic tissue that is constantly remodelled by bone resorbing osteoclasts and bone forming osteoblasts, respectively. A breakdown in the remodelling process underlies several bone diseases such as osteoporosis. Unsaturated fatty acids (UFAs) have been shown to have beneficial effects on bone health. However, the mechanism of action of UFAs in bone remains unclear. Free fatty acid receptor 4 (FFAR4) is expressed in bone cells and preferentially binds ω-3 and ω-7 UFAs. Therefore, we sought to determine if FFAR4 influenced the action of different classes of UFAs in bone cells. FFAR4 and potential signalling pathways, ß-arrestin 2 (ßarr2) and Gαq, were silenced in RAW264.7 murine macrophages (pre-osteoclasts) and MC3T3-E1 murine pre-osteoblasts. Cell differentiation, activation of signalling pathways and expression of regulatory genes were evaluated. The ω-3 UFAs, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and the ω-7 UFA, palmitoleic acid (PLA), were shown to require the FFAR4/ßarr2 signalling pathway to inhibit osteoclast differentiation in RAW264.7 murine macrophages. The ω-6 UFA, arachidonic acid, and the ω-9 UFA, oleic acid (OA), were shown to inhibit osteoclast formation but did not use FFAR4. DHA, EPA, PLA and OA enhanced osteoblast signalling through the FFAR4/ßarr2 signalling axis. This study reveals that FFAR4/ßarr2 signalling may mediate the bone protective effects of different classes of UFAs in osteoclasts and osteoblasts.

Preconception Plasma Phospholipid Fatty Acids and Fecundability.

Context: Fatty acids (FAs) are important for reproductive processes, including steroidogenesis, though associations with fecundability, as measured by time to pregnancy (TTP), are unclear. Objective: To investigate the relationship between preconception plasma phospholipid FA (PPFA) levels and time to human chorionic gonadotropin-pregnancy among women with prior pregnancy loss. Design, Setting, and Participants: Prospective cohort of 1228 women attempting pregnancy (aged 18 to 40 years, with one or two prior pregnancy losses) followed for up to six cycles at four US university medical centers during 2006 to 2012. PPFA levels were measured at baseline. Main Outcome Measures: Associations with fecundability overall and by body mass index (BMI) group after adjusting for confounders were estimated using fecundability odds ratios (FORs) and 95% CIs. False discovery rate (FDR) was used to account for multiple comparisons. Results: Monounsaturated fatty acids (MUFAs) were associated with increased fecundability or shorter TTP [FOR, 1.08 (95% CI, 1.01 to 1.16) per unit increase in percentage of total FAs], whereas polyunsaturated fatty acids (PUFAs) were associated with decreased fecundability or longer TTP [FOR, 0.95 (95% CI, 0.91 to 1.00) per 1% change], though associations only remained significant after FDR adjustment among women with BMI <25 kg/m2. Saturated FA and trans FA were not associated with fecundability. Omega-3 FAs and omega-6 linoleic acid were not associated with fecundability. Conclusion: We observed associations between preconception MUFA and PUFA levels and fecundability among women with normal BMI, highlighting the importance of FA composition among normal-weight women with prior pregnancy loss.

Short chain and polyunsaturated fatty acids in host gut health and foodborne bacterial pathogen inhibition.

As a major source of microbes and their numerous beneficial effects, the gut microflora/microbiome is intimately linked to human health and disease. The exclusion of enteric pathogens by these commensal microbes partially depends upon the production of bioactive compounds such as short-chain fatty acids (SCFAs) and polyunsaturated fatty acids (PUFAs). These key intestinal microbial byproducts are crucial to the maintenance of a healthy gut microbial community. Moreover, SCFAs and PUFAs play multiple critical roles in host defense and immunity, including anti-cancer, anti-inflammation, and anti-oxidant activities, as well as out-competition of enteric bacterial pathogens. In this review article, we hereby aim to highlight the importance of SCFAs and PUFAs and the microbes involved in production of these beneficial intestinal components, and their biological functions, specifically as to their immunomodulation and interactions with enteric bacterial pathogens. Finally, we also advance potential applications of these fatty acids with regards to food safety and human gut health.

[Progress in study on the correlation of polyunsaturated fatty acids, vitamin D and homocysteine with postpartum depression].

Postpartum depression(PPD) is a common emotional disorder in the puerperium, which has negative impact on women, infants and family. There is growing evidence that abnormal concentration of a number of nutrients (including polyunsaturated fatty acids, vitamin D and homocysteine) is associated with depression in postpartum population. Further studies on the mechanisms for the functions of nutrients and regulation of nutritional states in the puerperium will be of great value in the prevention, early diagnosis and treatment of PPD.

Long-Chain Polyunsaturated Fatty Acids and Clinical Outcomes of Preterm Infants.

Long-chain polyunsaturated fatty acids (LCPUFAs) play specific roles during the perinatal period and are very important nutrients to consider. The possible effects of LCPUFAs, particularly docosahexaenoic acid (DHA), on various clinical outcomes of preterm infants are discussed in this paper. Since DHA accumulates in the central nervous system during development, a lot of attention has focused on the effects of DHA on neurodevelopment. Experimental studies as well as recent clinical trials show that providing larger amounts of DHA than currently and routinely provided is associated with better neurological outcomes at 18 months to 2 years. This early advantage, however, does not seem to translate into detectable change in visual and neurodevelopmental outcomes or behavior when assessed in childhood. There is growing evidence that, in addition to effects on development, omega-3 LCPUFAs may reduce the incidence or severity of neonatal morbidities by affecting different steps of the immune and anti-inflammatory response. Studies in preterm infants suggest that the omega-3 LCPUFAs may play a significant role by reducing the risk of bronchopulmonary dysplasia, necrotizing enterocolitis and possibly retinopathy of prematurity and sepsis. Overall, evidence is increasing to support the benefits of high-dose DHA for various health outcomes of preterm infants. These findings are of major clinical relevance mainly because infants born preterm are at particularly high risk for a nutritional deficit in omega-3 fatty acids, predisposing to adverse neonatal outcomes. Further studies are warranted to address these issues as well as to more precisely determine the LCPUFA requirement in order to favor the best possible outcomes of preterm infants.

Growth curves in Down syndrome with congenital heart disease / Curvas de crescimento na síndrome de Down com cardiopatia congênita

SUMMARY Introduction: To assess dietary habits, nutritional status and food frequency in children and adolescents with Down syndrome (DS) and congenital heart disease (CHD). Additionally, we attempted to compare body mass index (BMI) classifications according to the World Health Organization (WHO) curves and curves developed for individuals with DS. Method: Cross-sectional study including individuals with DS and CHD treated at a referral center for cardiology, aged 2 to 18 years. Weight, height, BMI, total energy and food frequency were measured. Nutritional status was assessed using BMI for age and gender, using curves for evaluation of patients with DS and those set by the WHO. Results: 68 subjects with DS and CHD were evaluated. Atrioventricular septal defect (AVSD) was the most common heart disease (52.9%). There were differences in BMI classification between the curves proposed for patients with DS and those proposed by the WHO. There was an association between consumption of vitamin E and polyunsaturated fatty acids. Conclusion: Results showed that individuals with DS are mostly considered normal weight for age, when evaluated using specific curves for DS. Reviews on specific curves for DS would be the recommended practice for health professionals so as to avoid precipitated diagnosis of overweight and/or obesity in this population.

RESUMO Objetivo: avaliar hábitos alimentares, estado nutricional e frequência alimentar em crianças e adolescentes com síndrome de Down (SD) portadores de cardiopatia congênita (CC). Adicionalmente, procurou-se comparar classificações de índice de massa corpórea (IMC) de acordo com curvas da Organização Mundial da Saúde (OMS) e curvas desenvolvidas para indivíduos com SD. Método: estudo transversal com indivíduos portadores de SD e CC atendidos em um centro de referência para cardiologia, com idade entre 2 e 18 anos. Foram aferidos peso, altura, IMC, valor energético total (VET) e frequência alimentar. O estado nutricional foi analisado por meio de IMC para gênero e idade, utilizando-se curvas específicas para SD e curvas da OMS. Resultados: foram avaliados 68 indivíduos portadores de SD com CC. O defeito do septo atrioventricular (DSAV) foi a cardiopatia mais frequente (52,9%). Houve diferença de classificação do IMC entre as curvas propostas para portadores de SD e pela OMS. Houve associação entre consumo de vitamina E e ácidos graxos poli-insaturados. Conclusão: resultados mostraram que indivíduos com SD são, em sua maioria, considerados eutróficos para a idade quando avaliados pelas curvas específicas para SD. Avaliá-los de acordo com as curvas específicas para SD seria o recomendado para a prática dos profissionais da saúde, evitando-se diagnósticos precipitados de sobrepeso e/ou obesidade nessa população.

Growth curves in Down syndrome with congenital heart disease.

INTRODUCTION: To assess dietary habits, nutritional status and food frequency in children and adolescents with Down syndrome (DS) and congenital heart disease (CHD). Additionally, we attempted to compare body mass index (BMI) classifications according to the World Health Organization (WHO) curves and curves developed for individuals with DS. METHOD: Cross-sectional study including individuals with DS and CHD treated at a referral center for cardiology, aged 2 to 18 years. Weight, height, BMI, total energy and food frequency were measured. Nutritional status was assessed using BMI for age and gender, using curves for evaluation of patients with DS and those set by the WHO. RESULTS: 68 subjects with DS and CHD were evaluated. Atrioventricular septal defect (AVSD) was the most common heart disease (52.9%). There were differences in BMI classification between the curves proposed for patients with DS and those proposed by the WHO. There was an association between consumption of vitamin E and polyunsaturated fatty acids. CONCLUSION: Results showed that individuals with DS are mostly considered normal weight for age, when evaluated using specific curves for DS. Reviews on specific curves for DS would be the recommended practice for health professionals so as to avoid precipitated diagnosis of overweight and/or obesity in this population.

CYP2J2 - regulation, function and polymorphism.

Polyunsaturated fatty acids (PUFAs) undergo cytochrome P450 (CYP)-dependent oxidation to epoxides that modulate important physiological functions, including vasoactivity, inflammation, nociception, proliferation and viability. One of the most important human CYP epoxygenases is human CYP2J2 that is widely expressed in tissues, especially heart, vascular smooth muscle, salivary glands and placenta. Recent studies have shown that overexpression of CYP2J2 in vivo reverses several pathological processes in animals, including hypertension and other cardiovascular pathologies and insulin resistance. Information on the molecular regulation of CYP2J2 is sparse but supports roles for specificity protein-1 (Sp1) and activator protein-1 (AP-1) in transcription and the micro-RNA Let-7b in post-transcriptional regulation. Exposure to stress stimuli, including pro- and antioxidant factors and pro-inflammatory cytokines regulates CYP2J2, possibly in a cell-specific fashion. CYP2J2 is also subject to genetic variation and the promoter region SNP (CYP2J2-76G > T; *7 allele) reportedly decreases epoxygenase activity in vivo. Several studies have suggested that carriers of the *7 allele may be predisposed to adverse cardiovascular and related health outcomes, although other studies report different findings. Greater understanding of the mechanisms by which CYP2J2 is regulated could provide insights into important pathogenic processes in complex disease states. Such studies may also lead to the development of novel therapeutic strategies that seek to activate CYP2J2 expression in tissues. Additionally, the development of agents that promote fatty acid epoxide production, or stable analogs that retain the activities of the epoxides, offer promising new avenues for utilizing the beneficial actions of these molecules.

Short update on docosapentaenoic acid: a bioactive long-chain n-3 fatty acid.

PURPOSE OF REVIEW: Docosapentaenoic acid (DPA) is a long-chain n-3 polyunsaturated fatty acid that is intermediary between eicosapentaenoic acid and docosahexaenoic acid in the n-3 synthesis pathway. DPA is part of our normal diet through fish and lean red meat. In recent years, DPA has received increasing attention as an important bioactive fatty acid in light of its potential beneficial health effects, which include anti-inflammatory actions, antiplatelet aggregation, and improved plasma lipid prolife. This review provides a short summary of the most recent research on DPA. RECENT FINDINGS: In this review, we report on the latest association data as well as data generated from in-vitro and in-vivo studies on DPA and cardiovascular health, mental health, inflammation, and cancer. We also report on the newly identified DPA metabolites and their effects on exacerbation of inflammation in animal models. SUMMARY: Although there is a growing body of evidence supporting DPA's role as an important bioactive fatty acid, there is a need for more 'cause and effect studies', clinical trials and studies which can reveal whether DPA plays separate roles to those identified for eicosapentaenoic acid and docosahexaenoic acid.

Males on demand: the environmental-neuro-endocrine control of male sex determination in daphnids.

Branchiopod crustaceans (e.g., Daphnia sp.) and some other taxa utilize both asexual and sexual reproduction to maximize population sustainability. The decision to switch from asexual to sexual reproduction is triggered by environmental cues that foretell a potentially detrimental change in environmental conditions. This review describes the cascade of events beginning with environmental cues and ending with changes in gene expression that dictate male sex determination in daphnids, the initial event in the switch to sexual reproduction. Several environmental cues have been identified which, either in isolation or in combination, stimulate male sex determination. These cues are typically associated with change of season, exhaustion of resources or loss of habitat. Maternal daphnids receive and respond to these cues, we propose, through the secretion of neuropeptides, which suppress (hyperglycemic hormone-like neuropeptides, allatostatin) or stimulate (allatotropin) the male sex differentiation program. In response, maternal daphnids produce the male sex-determining hormone, methyl farnesoate. Methyl farnesoate binds to a protein MET that dimerizes with the protein SRC forming an active transcription factor. This complex then regulates the expression of genes, primarily doublesex (dsx), involved in programming the single-celled embryo to develop into a male. In the absence of methyl farnesoate programming, the embryo develops into a female. Epigenetic modifications of the genome as a possible mode of methyl farnesoate action and the utility of this model to decipher the role of epigenetics in sex differentiation in other species are discussed.

Understanding the local actions of lipids in bone physiology.

The adult skeleton is a metabolically active organ system that undergoes continuous remodeling to remove old and/or stressed bone (resorption) and replace it with new bone (formation) in order to maintain a constant bone mass and preserve bone strength from micro-damage accumulation. In that remodeling process, cellular balances--adipocytogenesis/osteoblastogenesis and osteoblastogenesis/osteoclastogenesis--are critical and tightly controlled by many factors, including lipids as discussed in the present review. Interest in the bone lipid area has increased as a result of in vivo evidences indicating a reciprocal relationship between bone mass and marrow adiposity. Lipids in bones are usually assumed to be present only in the bone marrow. However, the mineralized bone tissue itself also contains small amounts of lipids which might play an important role in bone physiology. Fatty acids, cholesterol, phospholipids and several endogenous metabolites (i.e., prostaglandins, oxysterols) have been purported to act on bone cell survival and functions, the bone mineralization process, and critical signaling pathways. Thus, they can be regarded as regulatory molecules important in bone health. Recently, several specific lipids derived from membrane phospholipids (i.e., sphingosine-1-phosphate, lysophosphatidic acid and different fatty acid amides) have emerged as important mediators in bone physiology and the number of such molecules will probably increase in the near future. The present paper reviews the current knowledge about: (1°) bone lipid composition in both bone marrow and mineralized tissue compartments, and (2°) local actions of lipids on bone physiology in relation to their metabolism. Understanding the roles of lipids in bone is essential to knowing how an imbalance in their signaling pathways might contribute to bone pathologies, such as osteoporosis.

Testing the interactive effects of carotenoids and polyunsaturated fatty acids on ejaculate traits in the guppy Poecilia reticulata (Pisces: Poeciliidae).

Using the polyandrous livebearing guppy Poecilia reticulata, this study revealed no main effects of carotenoids in the diet on ejaculate traits, but significant main effects of polyunsaturated fatty acids (PUFAs) on sperm viability and weak but significant interacting effects of both nutrients on sperm length. Collectively, these findings not only add evidence that PUFAs are critical determinants of sperm quality, but also provide tentative evidence that for some traits these effects may be moderated by carotenoid intake.