Early dietary treatments with Lorenzo's oil and docosahexaenoic acid for neurological development in a case with Zellweger syndrome

Nervonic Acid Synthesis Substrates as Essential Components in Profiled Lipid Supplementation for More Effective Central Nervous System Regeneration

Central nervous system (CNS) damage leads to severe neurological dysfunction as a result of neuronal cell death and axonal degeneration. As, in the mature CNS, neurons have little ability to regenerate their axons and reconstruct neural loss, demyelination is one of the hallmarks of neurological disorders such as multiple sclerosis (MS). Unfortunately, remyelination, as a regenerative process, is often insufficient to prevent axonal loss and improve neurological deficits after demyelination. Currently, there are still no effective therapeutic tools to restore neurological function, but interestingly, emerging studies prove the beneficial effects of lipid supplementation in a wide variety of pathological processes in the human body. In the future, available lipids with a proven beneficial effect on CNS regeneration could be included in supportive therapy, but this topic still requires further studies. Based on our and others' research, we review the role of exogenous lipids, pointing to substrates that are crucial in the remyelination process but are omitted in available studies, justifying the properly profiled supply of lipids in the human diet as a supportive therapy during CNS regeneration.

De novo synthesis of nervonic acid and optimization of metabolic regulation by Yarrowia lipolytica

Nervonic acid, a natural fatty acid compound and also a core component of nerve fibers and nerve cells, has been widely used to prevent and treat related diseases of the brain nervous system. At present, fatty acids and their derivatives are mainly obtained by natural extraction or chemical synthesis which are limited by natural resources and production costs. In this study, the de novo synthetic pathway of nervonic acid was constructed in Yarrowia lipolytica by means of synthetic biology, and the yield of nervonic acid was further improved by metabolic engineering and fermentation optimization. Specially, heterologous elongases and desaturases derived from different organism were successfully expressed and evaluated for their potential for the production of nervonic acid in Y. lipolytica. Meanwhile, we overexpressed the genes involved in the lipid metabolism to increase the nervonic acid titer to 111.6 mg/L. In addition, the potential of adding oil as auxiliary carbon sources for nervonic acid production by the engineered Y. lipolytica was analyzed. The results indicated that supplementation with colleseed oil as an auxiliary carbon source can be beneficial for the nervonic acid productivity, which led to the highest concentration of 185.0 mg/L in this work. To summarize, this study describes that the Y. lipolytica can be used as a promising platform for the production of nervonic acid and other very long-chain fatty acids.

Ribosome footprint profiling enables elucidating the systemic regulation of fatty acid accumulation in Acer truncatum

BACKGROUND

The accumulation of fatty acids in plants covers a wide range of functions in plant physiology and thereby affects adaptations and characteristics of species. As the famous woody oilseed crop, Acer truncatum accumulates unsaturated fatty acids and could serve as the model to understand the regulation and trait formation in oil-accumulation crops. Here, we performed Ribosome footprint profiling combing with a multi-omics strategy towards vital time points during seed development, and finally constructed systematic profiling from transcription to proteomes. Additionally, we characterized the small open reading frames (ORFs) and revealed that the translational efficiencies of focused genes were highly influenced by their sequence features.

RESULTS

The comprehensive multi-omics analysis of lipid metabolism was conducted in A. truncatum. We applied the Ribo-seq and RNA-seq techniques, and the analyses of transcriptional and translational profiles of seeds collected at 85 and 115 DAF were compared. Key members of biosynthesis-related structural genes (LACS, FAD2, FAD3, and KCS) were characterized fully. More meaningfully, the regulators (MYB, ABI, bZIP, and Dof) were identified and revealed to affect lipid biosynthesis via post-translational regulations. The translational features results showed that translation efficiency tended to be lower for the genes with a translated uORF than for the genes with a non-translated uORF. They provide new insights into the global mechanisms underlying the developmental regulation of lipid metabolism.

CONCLUSIONS

We performed Ribosome footprint profiling combing with a multi-omics strategy in A. truncatum seed development, which provides an example of the use of Ribosome footprint profiling in deciphering the complex regulation network and will be useful for elucidating the metabolism of A. truncatum seed oil and the regulatory mechanisms.

Characterization of Severity in Zellweger Spectrum Disorder by Clinical Findings: A Scoping Review, Meta-Analysis and Medical Chart Review

Zellweger spectrum disorder (ZSD) is a rare, debilitating genetic disorder of peroxisome biogenesis that affects multiple organ systems and presents with broad clinical heterogeneity. Although severe, intermediate, and mild forms of ZSD have been described, these designations are often arbitrary, presenting difficulty in understanding individual prognosis and treatment effectiveness. The purpose of this study is to conduct a scoping review and meta-analysis of existing literature and a medical chart review to determine if characterization of clinical findings can predict severity in ZSD. Our PubMed search for articles describing severity, clinical findings, and survival in ZSD resulted in 107 studies (representing 307 patients) that were included in the review and meta-analysis. We also collected and analyzed these same parameters from medical records of 136 ZSD individuals from our natural history study. Common clinical findings that were significantly different across severity categories included seizures, hypotonia, reduced mobility, feeding difficulties, renal cysts, adrenal insufficiency, hearing and vision loss, and a shortened lifespan. Our primary data analysis also revealed significant differences across severity categories in failure to thrive, gastroesophageal reflux, bone fractures, global developmental delay, verbal communication difficulties, and cardiac abnormalities. Univariable multinomial logistic modeling analysis of clinical findings and very long chain fatty acid (VLCFA) hexacosanoic acid (C26:0) levels showed that the number of clinical findings present among seizures, abnormal EEG, renal cysts, and cardiac abnormalities, as well as plasma C26:0 fatty acid levels could differentiate severity categories. We report the largest characterization of clinical findings in relation to overall disease severity in ZSD. This information will be useful in determining appropriate outcomes for specific subjects in clinical trials for ZSD.

The Key Role of Peroxisomes in Follicular Growth, Oocyte Maturation, Ovulation, and Steroid Biosynthesis

The absence of peroxisomes can cause disease in the human reproductive system, including the ovaries. The available peroxisomal gene-knockout female mouse models, which exhibit pathological changes in the ovary and reduced fertility, are listed in this review. Our review article provides the first systematic presentation of peroxisomal regulation and its possible functions in the ovary. Our immunofluorescence results reveal that peroxisomes are present in all cell types in the ovary; however, peroxisomes exhibit different numerical abundances and strong heterogeneity in their protein composition among distinct ovarian cell types. The peroxisomal compartment is strongly altered during follicular development and during oocyte maturation, which suggests that peroxisomes play protective roles in oocytes against oxidative stress and lipotoxicity during ovulation and in the survival of oocytes before conception. In addition, the peroxisomal compartment is involved in steroid synthesis, and peroxisomal dysfunction leads to disorder in the sexual hormone production process. However, an understanding of the cellular and molecular mechanisms underlying these physiological and pathological processes is lacking. To date, no effective treatment for peroxisome-related disease has been developed, and only supportive methods are available. Thus, further investigation is needed to resolve peroxisome deficiency in the ovary and eventually promote female fertility.

Transcriptome sequencing and flavonoid metabolism analysis in the leaves of three different cultivars of Acer truncatum

Young and mature leaves of three Acer truncatum varieties with different leaf colors were examined. Transcriptome sequencing and flavonoid metabolism were used to analyze the differential gene expression associated with different leaf colors and growth stages and the relationships between gene expression and flavonoid and anthocyanin contents to improve ornamental value and develop flavonoid-rich A. truncatum. Kyoto Encyclopedia of Genes and Genomes database annotation of differentially expressed genes indicated that the following genes were related to flavonoid synthesis: phenylpropanoid biosynthesis genes (PAL, C4H, 4CL and CHS), flavonoid biosynthesis genes (E2.1.1.104, CHI, FLS, F3'5'H and ANR), anthocyanin biosynthesis genes (ANS, DFR, HCT, BZ1, GT1, and UGT79B1), isoflavonoid biosynthesis genes (HIDH and CYP81E17), and their transcriptional regulator (MYB). A total of 234 types of flavonoids were detected. The types and contents of anthocyanins in the red-leaf varieties 'Hong Jingling' and 'Caidie Fanfei' were significantly higher than those in the green leaf cultivar 'Lv Baoshi', especially morning glory 3-O-glucoside, delphinidin 3-O-glucoside, and pelargonium-3-O-glucoside, which were not detected in 'Lv Baoshi'. Combined omics analysis showed that downregulated expression of C4H, CHS and F3'5'H and upregulated expression of FLS reduced the supply of raw materials for anthocyanin synthesis, and downstream ANR upregulation converted anthocyanins to procyanidins, increasing the total flavonoid content. F3'5'H expression was downregulated in the leaves of each variety with development, resulting in the accumulation of catechins and the gradual greening of the leaves. F3'5'H was significantly depleted in the young leaves of 'Hong Jingling' and 'Caidie Fanfei' compared with the young leaves of 'Lv Baoshi', while ANS and BZ1 were enriched significantly. It is concluded that F3'5'H, BZ1, and ANS are the key genes needed for breeding red A. truncatum and that ANR is the key gene needed for breeding varieties with a high flavonoids contens. These results may facilitate genetic modification or selection for further improvement of the ornamental qualities and flavonoid content of A. truncatum.

Assembly and comparative analysis of the first complete mitochondrial genome of Acer truncatum Bunge: a woody oil-tree species producing nervonic acid

BACKGROUND

Acer truncatum (purpleblow maple) is a woody tree species that produces seeds with high levels of valuable fatty acids (especially nervonic acid). The species is admired as a landscape plant with high developmental prospects and scientific research value. The A. truncatum chloroplast genome has recently been reported; however, the mitochondrial genome (mitogenome) is still unexplored.

RESULTS

We characterized the A. truncatum mitogenome, which was assembled using reads from PacBio and Illumina sequencing platforms, performed a comparative analysis against different species of Acer. The circular mitogenome of A. truncatum has a length of 791,052 bp, with a base composition of 27.11% A, 27.21% T, 22.79% G, and 22.89% C. The A. truncatum mitogenome contains 62 genes, including 35 protein-coding genes, 23 tRNA genes and 4 rRNA genes. We also examined codon usage, sequence repeats, RNA editing and selective pressure in the A. truncatum mitogenome. To determine the evolutionary and taxonomic status of A. truncatum, we conducted a phylogenetic analysis based on the mitogenomes of A. truncatum and 25 other taxa. In addition, the gene migration from chloroplast and nuclear genomes to the mitogenome were analyzed. Finally, we developed a novel NAD1 intron indel marker for distinguishing several Acer species.

CONCLUSIONS

In this study, we assembled and annotated the mitogenome of A. truncatum, a woody oil-tree species producing nervonic acid. The results of our analyses provide comprehensive information on the A. truncatum mitogenome, which would facilitate evolutionary research and molecular barcoding in Acer.

Plant monounsaturated fatty acids: Diversity, biosynthesis, functions and uses

Monounsaturated fatty acids are straight-chain aliphatic monocarboxylic acids comprising a unique carbon‑carbon double bond, also termed unsaturation. More than 50 distinct molecular structures have been described in the plant kingdom, and more remain to be discovered. The evolution of land plants has apparently resulted in the convergent evolution of non-homologous enzymes catalyzing the dehydrogenation of saturated acyl chain substrates in a chemo-, regio- and stereoselective manner. Contrasted enzymatic characteristics and different subcellular localizations of these desaturases account for the diversity of existing fatty acid structures. Interestingly, the location and geometrical configuration of the unsaturation confer specific characteristics to these molecules found in a variety of membrane, storage, and surface lipids. An ongoing research effort aimed at exploring the links existing between fatty acid structures and their biological functions has already unraveled the importance of several monounsaturated fatty acids in various physiological and developmental contexts. What is more, the monounsaturated acyl chains found in the oils of seeds and fruits are widely and increasingly used in the food and chemical industries due to the physicochemical properties inherent in their structures. Breeders and plant biotechnologists therefore develop new crops with high monounsaturated contents for various agro-industrial purposes.

Metabolomic analysis of white, green and purple morphs of sea cucumber Apostichopus japonicus during body color pigmentation process

The sea cucumber Apostichopus japonicus is an important economic species owing to their high nutritive and medicinal value. Body color is one of the most important traits in the cultivation, which affects taste and market price of holothurian products. Pigmentation is an important stage of sea cucumber growth and development, in addition to achieving rare and beautiful coloration. In this study, UHPLC-QTOF/MS technique was performed to analyze the metabolome of white, green and purple A. japonicus body wall during the pigmentation process. A total of 2633 metabolites were identified. OPLS-DA clearly discriminated the body wall metabolites among the three color morphs. In addition, 13 annotated metabolites that could discriminate white, green and purple A. japonicus were screened out. KEGG metabolic pathway analysis revealed that "biosynthesis of unsaturated fatty acids" and "fatty acid biosynthesis" were closely related in the different color morphs. Furthermore, we performed comparative analysis of polysaccharide and saponin among white, green and purple A. japonicus. The results showed that the content of polysaccharide and saponin in purple A. japonicus was the highest, while that in white A. japonicus was the lowest. This study will provide valuable information for future studies on sea cucumber and the molecular mechanism underlying pigmentation and color polymorphism, and may contribute to support the culturing of desirable color morphs.

Diversity in seed oil content and fatty acid composition in Acer species with potential as sources of nervonic acid

Nervonic acid (NA, cis-15-tetracosenoic acid) is a very long-chain monounsaturated fatty acid that has been shown to be a core component of nerve fibers and nerve cells. It can be used to treat and prevent many neurological diseases. At present, commercially available NA is mainly derived from Acer truncatum seeds, which contain about 5%-6% NA in their seed oil. The aim of this study were to identify and analyze NA-containing Acer species that could be used as NA resource plants. For this purpose, 46 Acer species seeds were collected in China and in some or all of the seed oils from these species 15 fatty acids were detected, including linoleic acid, oleic acid (C18:1Δ9, C18:1Δ11), erucic acid, palmitic acid, NA, linolenic acid (C18:3Δ6,9,12, C18:3Δ9,12,15), eicosenoic acid (C20:1Δ11, C20:1Δ13), stearic acid, behenic acid, tetracosanoic acid, arachidic acid, and docosadienoic acid. Nervonic acid was detected in all samples, but the content was highly variable among species. NA content over 9% was detected in eleven species, of which Acer elegantulum had the highest levels (13.90%). The seed oil content, seed weight, and fatty acid profiles varied among species, but the comprehensive evaluation value (W) showed that A. coriaceifolium could be a new potential NA resources plant. The results also showed that NA was significantly negatively correlated with palmitic acid, oleic acid, and eicosenoic acid, but positively correlated with eicosadienoic acid, behenic acid, erucic acid, and tetracosanoic acid, which indicate the probable pathway for NA biosynthesis in Acer plants. This study has identified Acer species that may serve as NA resources and will help guide subsequent species breeding programs.

The Acer truncatum genome provides insights into nervonic acid biosynthesis

Acer truncatum (purpleblow maple) is a woody tree species that produces seeds with high levels of valuable fatty acids (especially nervonic acid). However, the lack of a complete genome sequence has limited both basic and applied research on A. truncatum. We describe a high-quality draft genome assembly comprising 633.28 Mb (contig N50 = 773.17 kb; scaffold N50 = 46.36 Mb) with at least 28 438 predicted genes. The genome underwent an ancient triplication, similar to the core eudicots, but there have been no recent whole-genome duplication events. Acer yangbiense and A. truncatum are estimated to have diverged about 9.4 million years ago. A combined genomic, transcriptomic, metabonomic, and cell ultrastructural analysis provided new insights into the biosynthesis of very long-chain monounsaturated fatty acids. In addition, three KCS genes were found that may contribute to regulating nervonic acid biosynthesis. The KCS paralogous gene family expanded to 28 members, with 10 genes clustered together and distributed in the 0.27-Mb region of pseudochromosome 4. Our chromosome-scale genomic characterization may facilitate the discovery of agronomically important genes and stimulate functional genetic research on A. truncatum. Furthermore, the data presented also offer important foundations from which to study the molecular mechanisms influencing the production of nervonic acids.

Effects of Malania oleifera Chun Oil on the Improvement of Learning and Memory Function in Mice

BACKGROUND

The fruits of Malania oleifera Chun & S. K. Lee have been highly sought after medically because its seeds have high oil content (>60%), especially the highest known proportion of nervonic acid (>55%). Objective of the Study. The objective was to explore the effects of different doses of Malania oleifera Chun oil (MOC oil) on the learning and memory of mice and to evaluate whether additional DHA algae oil and vitamin E could help MOC oil improve learning and memory and its possible mechanisms.

METHODS

After 30 days of oral administration of the relevant agents to mice, behavioral tests were conducted as well as detection of oxidative stress parameters (superoxide dismutase, malondialdehyde, and glutathione peroxidase) and biochemical indicators (acetylcholine, acetyl cholinesterase, and choline acetyltransferase) in the hippocampus.

RESULTS

Experimental results demonstrated that MOC oil treatment could markedly improve learning and memory of mouse models in behavioral experiments and increase the activity of GSH-PX in hippocampus and reduce the content of MDA, especially the dose of 46.27 mg/kg. The addition of DHA and VE could better assist MOC oil to improve the learning and memory, and its mechanism may be related to the inhibition of oxidative stress and restrain the activity of AChE and also increase the content of ACh.

CONCLUSION

Our results demonstrated that MOC oil treatment could improve learning and memory impairments. Therefore, we suggest that MOC oil is a potentially important resource for the development of nervonic acid products.

Docosahexaenoic Acid Attenuates Mitochondrial Alterations and Oxidative Stress Leading to Cell Death Induced by Very Long-Chain Fatty Acids in a Mouse Oligodendrocyte Model

In the case of neurodegenerative pathologies, the therapeutic arsenal available is often directed towards the consequences of the disease. The purpose of this study is, therefore, to evaluate the ability of docosahexaenoic acid (DHA), a molecule present in certain foods and considered to have health benefits, to inhibit the cytotoxic effects of very long-chain fatty acids (C24:0, C26:0), which can contribute to the development of some neurodegenerative diseases. The effect of DHA (50 µM) on very long-chain fatty acid-induced toxicity was studied by several complementary methods: phase contrast microscopy to evaluate cell viability and morphology, the MTT test to monitor the impact on mitochondrial function, propidium iodide staining to study plasma membrane integrity, and DHE staining to measure oxidative stress. A Western blot assay was used to assess autophagy through modification of LC3 protein. The various experiments were carried out on the cellular model of 158N murine oligodendrocytes. In 158N cells, our data establish that DHA is able to inhibit all tested cytotoxic effects induced by very long-chain fatty acids.

A mini review of nervonic acid: Source, production, and biological functions

Nervonic acid (NA) has attracted considerable attention because of its close relationship with brain development. Sources of NA include oil crop seeds, oil-producing microalgae, and other microorganisms. Transgenic technology has also been applied to improve the sources and production of NA. NA can be separated and purified by urea adduction fractionation, molecular distillation, and crystallization. Studies on NA functionality involved treatments for demyelinating diseases and acquired immunodeficiency syndrome, as well as prediction of mortality due to cardiovascular diseases and chronic kidney disease. This mini review focuses on the sources, production, and biological functions of NA and provides prospective trends in the investigation of NA.

Transcriptome analysis reveals crucial genes involved in the biosynthesis of nervonic acid in woody Malania oleifera oilseeds

BACKGROUND

Malania oleifera Chun et Lee (Olacaceae), an evergreen broad-leaved woody tree native to southwest China, is an important oilseed tree. Its seed oil has a high level of nervonic acid (cis-tetracos-15-enoic acid, over 60%), which is essential for human health. M. oleifera seed oil is a promising source of nervonic acid, but little is known about the physiological and molecular mechanisms underlying its biosynthesis.

RESULTS

In this study, we recorded oil accumulation at four stages of seed development. Using a high-throughput RNA-sequencing technique, we obtained 55,843 unigenes, of which 29,176 unigenes were functionally annotated. By comparison, 22,833 unigenes had a two-fold or greater expression at the fast oil accumulation stage than at the initial stage. Of these, 198 unigenes were identified as being functionally involved in diverse lipid metabolism processes (including de novo fatty acid synthesis, carbon chain elongation and modification, and triacylglycerol assembly). Key genes (encoding KCS, KCR, HCD and ECR), putatively responsible for nervonic acid biosynthesis, were isolated and their expression profiles during seed development were confirmed by quantitative real-time PCR analysis. Also, we isolated regulatory factors (such as WRI1, ABI3 and FUS3) that are putatively involved in the regulation of oil biosynthesis and seed development.

CONCLUSION

Our results provide novel data on the physiological and molecular mechanisms of nervonic acid biosynthesis and oil accumulation in M. oleifera seeds, and will also serve as a starting point for biotechnological genetic engineering for the production of nervonic acid resources.

Carriers of an apolipoprotein E epsilon 4 allele are more vulnerable to a dietary deficiency in omega-3 fatty acids and cognitive decline

Carriers of an epsilon 4 allele (E4) of apolipoprotein E (APOE) develop Alzheimer's disease (AD) earlier than carriers of other APOE alleles. The metabolism of plasma docosahexaenoic acid (DHA, 22:6n-3), an omega-3 fatty acid (n-3 FA), taken up by the brain and concentrated in neurons, is disrupted in E4 carriers, resulting in lower levels of brain DHA. Behavioural and cognitive impairments have been observed in animals with lower brain DHA levels, with emphasis on loss of spatial memory and increased anxiety. E4 mice provided a diet deficient in n-3 FA had a greater depletion of n-3 FA levels in organs and tissues than mice carrying other APOE alleles. However, providing n-3 FA can restore levels of brain DHA in E4 animals and in other models of n-3 FA deficiency. In E4 carriers, supplementation with DHA as early as possible might help to prevent the onset of AD and could halt the progression of, and reverse some of the neurological and behavioural consequences of their higher vulnerability to n-3 FA deficiency.

Peroxisomal biogenesis is genetically and biochemically linked to carbohydrate metabolism in Drosophila and mouse

Peroxisome biogenesis disorders (PBD) are a group of multi-system human diseases due to mutations in the PEX genes that are responsible for peroxisome assembly and function. These disorders lead to global defects in peroxisomal function and result in severe brain, liver, bone and kidney disease. In order to study their pathogenesis we undertook a systematic genetic and biochemical study of Drosophila pex16 and pex2 mutants. These mutants are short-lived with defects in locomotion and activity. Moreover these mutants exhibit severe morphologic and functional peroxisomal defects. Using metabolomics we uncovered defects in multiple biochemical pathways including defects outside the canonical specialized lipid pathways performed by peroxisomal enzymes. These included unanticipated changes in metabolites in glycolysis, glycogen metabolism, and the pentose phosphate pathway, carbohydrate metabolic pathways that do not utilize known peroxisomal enzymes. In addition, mutant flies are starvation sensitive and are very sensitive to glucose deprivation exhibiting dramatic shortening of lifespan and hyperactivity on low-sugar food. We use bioinformatic transcriptional profiling to examine gene co-regulation between peroxisomal genes and other metabolic pathways and we observe that the expression of peroxisomal and carbohydrate pathway genes in flies and mouse are tightly correlated. Indeed key steps in carbohydrate metabolism were found to be strongly co-regulated with peroxisomal genes in flies and mice. Moreover mice lacking peroxisomes exhibit defective carbohydrate metabolism at the same key steps in carbohydrate breakdown. Our data indicate an unexpected link between these two metabolic processes and suggest metabolism of carbohydrates could be a new therapeutic target for patients with PBD.

Novel compound heterozygous mutations in the PEX1 gene in two Chinese newborns with Zellweger syndrome based on whole exome sequencing

Peroxisome biogenesis disorders (PBDs) represent a spectrum of human genetic disorders that are characterized by damaged peroxisome assembly. In the newborn period, the characteristics of affected patients include dysmorphic facial features, neonatal hypotonia, seizures, ocular abnormalities, poor feeding, liver cysts with hepatic dysfunction and skeletal defects. These can be caused by a defect in at least 14 different PEX genes. In this study, whole-exome sequencing (WES) was performed on samples from two Chinese newborns with clinical features of Zellweger syndrome. WES identified two novel mutations (c.2416+1G>T and c.2489delT) in patient 1 and another two novel mutations (c.1483+1G>A and c.1727dupG) in patient 2 in the PEX1 gene. All four mutations have a serious influence on the protein function, which also highlights the power of WES, particularly in clinically challenging cases.

Zellweger spectrum disorders: clinical overview and management approach

Zellweger spectrum disorders (ZSDs) represent the major subgroup within the peroxisomal biogenesis disorders caused by defects in PEX genes. The Zellweger spectrum is a clinical and biochemical continuum which can roughly be divided into three clinical phenotypes. Patients can present in the neonatal period with severe symptoms or later in life during adolescence or adulthood with only minor features. A defect of functional peroxisomes results in several metabolic abnormalities, which in most cases can be detected in blood and urine. There is currently no curative therapy, but supportive care is available. This review focuses on the management of patients with a ZSD and provides recommendations for supportive therapeutic options for all those involved in the care for ZSD patients.

Hepatic dysfunction in peroxisomal disorders

The peroxisomal compartment in hepatocytes hosts several essential metabolic conversions. These are defective in peroxisomal disorders that are either caused by failure to import the enzymes in the organelle or by mutations in the enzymes or in transporters needed to transfer the substrates across the peroxisomal membrane. Hepatic pathology is one of the cardinal features in disorders of peroxisome biogenesis and peroxisomal β-oxidation although it only rarely determines the clinical fate. In mouse models of these diseases liver pathologies also occur, although these are not always concordant with the human phenotype which might be due to differences in diet, expression of enzymes and backup mechanisms. Besides the morphological changes, we overview the impact of peroxisome malfunction on other cellular compartments including mitochondria and the ER. We further focus on the metabolic pathways that are affected such as bile acid formation, and dicarboxylic acid and branched chain fatty acid degradation. It appears that the association between deregulated metabolites and pathological events remains unclear.

Peroxisome biogenesis in mammalian cells: The impact of genes and environment

The initiation and progression of many human diseases are mediated by a complex interplay of genetic, epigenetic, and environmental factors. As all diseases begin with an imbalance at the cellular level, it is essential to understand how various types of molecular aberrations, metabolic changes, and environmental stressors function as switching points in essential communication networks. In recent years, peroxisomes have emerged as important intracellular hubs for redox-, lipid-, inflammatory-, and nucleic acid-mediated signaling pathways. In this review, we focus on how nature and nurture modulate peroxisome biogenesis and function in mammalian cells. First, we review emerging evidence that changes in peroxisome activity can be linked to the epigenetic regulation of cell function. Next, we outline how defects in peroxisome biogenesis may directly impact cellular pathways involved in the development of disease. In addition, we discuss how changes in the cellular microenvironment can modulate peroxisome biogenesis and function. Finally, given the importance of peroxisome function in multiple aspects of health, disease, and aging, we highlight the need for more research in this still understudied field.

Combinatorial Effects of Fatty Acid Elongase Enzymes on Nervonic Acid Production in Camelina sativa

Very long chain fatty acids (VLCFAs) with chain lengths of 20 carbons and longer provide feedstocks for various applications; therefore, improvement of VLCFA contents in seeds has become an important goal for oilseed enhancement. VLCFA biosynthesis is controlled by a multi-enzyme protein complex referred to as fatty acid elongase, which is composed of β-ketoacyl-CoA synthase (KCS), β-ketoacyl-CoA reductase (KCR), β-hydroxyacyl-CoA dehydratase (HCD) and enoyl reductase (ECR). KCS has been identified as the rate-limiting enzyme, but little is known about the involvement of other three enzymes in VLCFA production. Here, the combinatorial effects of fatty acid elongase enzymes on VLCFA production were assessed by evaluating the changes in nervonic acid content. A KCS gene from Lunaria annua (LaKCS) and the other three elongase genes from Arabidopsis thaliana were used for the assessment. Five seed-specific expressing constructs, including LaKCS alone, LaKCS with AtKCR, LaKCS with AtHCD, LaKCS with AtECR, and LaKCS with AtKCR and AtHCD, were transformed into Camelina sativa. The nervonic acid content in seed oil increased from null in wild type camelina to 6-12% in LaKCS-expressing lines. However, compared with that from the LaKCS-expressing lines, nervonic acid content in mature seeds from the co-expressing lines with one or two extra elongase genes did not show further increases. Nervonic acid content from LaKCS, AtKCR and AtHCD co-expressing line was significantly higher than that in LaKCS-expressing line during early seed development stage, while the ultimate nervonic acid content was not significantly altered. The results from this study thus provide useful information for future engineering of oilseed crops for higher VLCFA production.

The pilot study: sphingomyelin-fortified milk has a positive association with the neurobehavioural development of very low birth weight infants during infancy, randomized control trial

AIM

This study was a randomised control trial to examine the effects of sphingomyelin (SM), on the mental, motor and behavioural development of premature infants.

PATIENTS AND METHODS

Randomised, double-blind controlled trial, enroling infants born with a birth weight of less than 1500 g between January 2004 and October 2007 at Juntendo University Hospital, with follow-up to 18 months. Twenty-four preterm babies were randomly assigned; 12 were assigned to a test group and fed SM-fortified milk (SM 20% of all phospholipids in milk) and 12 were assigned to a control group (SM 13% of all phospholipids in milk). We analysed the composition of the plasma phospholipids and red-cell-membrane fatty acids, after which VEP, Fagan, BSID-II, attention and memory tests were performed.

RESULTS

The percentage of SM in the total phospholipids was significantly higher in the trial group than in the control group at 4, 6 and 8 weeks. The Behaviour Rating Scale of the BSID-II, the Fagan test scores, the latency of VEP, and sustained attention test scores at 18 months were all significantly better in the trial group than in the control group.

CONCLUSION

This study is the first to report that nutritional intervention via administration of SM-fortified milk has a positive association with the neurobehavioural development of low-birth-weight infants. However, detailed studies on the effects of SM on longer-term development are required.

Omega 3 fatty acids and inborn errors of metabolism

A number of studies are investigating the role of n-3 polyunsaturated fatty acids in children with metabolic inborn errors, while the effects on visual and brain development in premature infants and neonates are well known. However, their function incertain chronic neurological, inflammatory and metabolic disorders is still under study. Standards should be established to help identify the need of docosahexaenoic acid supplementation in conditions requiring a restricted diet resulting in an altered metabolism system, and find scientific evidence on the effects of such supplementation. This study reviews relevant published literature to propose adequate n-3 intake or supplementation doses for different ages and pathologies. The aim of this review is to examine the effects of long chain polyunsaturated fatty acids supplementation in preventing cognitive impairment or in retarding its progress, and to identify nutritional deficiencies, in children with inborn errors of metabolism. Trials were identified from a search of the Cochrane and MEDLINE databases in 2011. These databases include all major completed and ongoing double-blind, placebo-controlled, randomized trials, as well as all studies in which omega-3 supplementation was administered to children with inborn errors, and studies assessing omega-3 fatty acids status in plasma in these pathologies. Although few randomized controlled trials met the inclusion criteria of this review, some evidenced that most of children with inborn errors are deficient in omega-3 fatty acids, and demonstrated that supplementation might improve their neural function, or prevent the progression of neurological impairment. Nontheless, further investigations are needed on this issue.

Mychonastes afer HSO-3-1 as a potential new source of biodiesel

BACKGROUND

Biodiesel is considered to be a promising future substitute for fossil fuels, and microalgae are one source of biodiesel. The ratios of lipid, carbohydrates and proteins are different in different microalgal species, and finding a good strain for oil production remains a difficult prospect. Strains producing valuable co-products would improve the viability of biofuel production.

RESULTS

In this study, we performed sequence analysis of the 18S rRNA gene and internal transcribed spacer (ITS) of an algal strain designated HSO-3-1, and found that it was closely related to the Mychonastes afer strain CCAP 260/6. Morphology and cellular structure observation also supported the identification of strain HSO-3-1 as M. afer. We also investigated the effects of nitrogen on the growth and lipid accumulation of the naturally occurring M. afer HSO-3-1, and its potential for biodiesel production. In total, 17 fatty acid methyl esters (FAMEs) were identified in M. afer HSO-3-1, using gas chromatography/mass spectrometry. The total lipid content of M. afer HSO-3-1 was 53.9% of the dry cell weight, and we also detected nervonic acid (C24:1), which has biomedical applications, making up 3.8% of total fatty acids. The highest biomass and lipid yields achieved were 3.29 g/l and 1.62 g/l, respectively, under optimized conditions.

CONCLUSION

The presence of octadecenoic and hexadecanoic acids as major components, with the presence of a high-value component, nervonic acid, renders M. afer HSO-3-1 biomass an economic feedstock for biodiesel production.

Increase in nervonic acid content in transformed yeast and transgenic plants by introduction of a Lunaria annua L. 3-ketoacyl-CoA synthase (KCS) gene

Nervonic acid is a Very Long-Chain Monounsaturated Fatty Acid (VLCMFA), 24:1 Delta15 (cis-tetracos-15-enoic acid) found in the seed oils of Lunaria annua, borage, hemp, Acer (Purpleblow maple) and Tropaeolum speciosum (Flame flower). However, of these, only the "money plant" (Lunaria annua L.) has been studied and grown sparingly for future development as a niche crop and the outlook has been disappointing. Therefore, our goal was to isolate and characterize strategic new genes for high nervonic acid production in Brassica oilseed crops. To this end, we have isolated a VLCMFA-utilizing 3-Keto-Acyl-CoA Synthase (KCS; fatty acid elongase; EC 2.3.1.86) gene from Lunaria annua and functionally expressed it in yeast, with the recombinant KCS protein able to catalyze the synthesis of several VLCMFAs, including nervonic acid. Seed-specific expression of the Lunaria KCS in Arabidopsis resulted in a 30-fold increase in nervonic acid proportions in seed oils, compared to the very low quantities found in the wild-type. Similar transgenic experiments using B. carinata as the host resulted in a 7-10 fold increase in seed oil nervonic acid proportions. KCS enzyme activity assays indicated that upon using (14)C-22:1-CoA as substrate, the KCS activity from developing seeds of transgenic B. carinata was 20-30-fold higher than the low erucoyl-elongation activity exhibited by wild type control plants. There was a very good correlation between the Lun KCS transcript intensity and the resultant 22:1-CoA KCS activity in developing seed. The highest nervonic acid level in transgenic B. carinata expressing the Lunaria KCS reached 30%, compared to 2.8% in wild type plant. In addition, the erucic acid proportions in these transgenic lines were considerably lower than that found in native Lunaria oil. These results show the functional utility of the Lunaria KCS in engineering new sources of high nervonate/reduced erucic oils in the Brassicaceae.