Very Long Chain Fatty Acids Research Articles

MSC-Derived Small Extracellular Vesicles Exert Cardioprotective Effect Through Reducing VLCFAs and Apoptosis in Human Cardiac Organoid IRI Model.

Cardiovascular diseases (CVDs) are the leading cause of death worldwide, accounting for 31% of all deaths globally. Myocardial ischemia-reperfusion injury (IRI), a common complication of CVDs, is a major cause of mortality and morbidity. Studies have shown efficacious use of mesenchymal stem cells-derived small extracellular vesicles (MSCs-EVs) to mitigate IRI in animals, but few research has been done on human-related models. In this study, human embryonic stem cell-derived chambered cardiac organoid (CCO) was used as a model system to study the effects of MSC-EVs on myocardial IRI. The results revealed that MSC-EVs treatment reduced apoptosis and improved contraction resumption of the CCOs. Metabolomics analysis showed that this effect could be attributed to EVs' ability to prevent the accumulation of unsaturated very long-chain fatty acids (VLCFAs). This was corroborated when inhibition of fatty acid synthase, which was reported to reduce VLCFAs, produced a similar protective effect to EVs. Overall, this study uncovered the mechanistic role of MSC-EVs in mitigating IRI that involves preventing the accumulation of unsaturated VLCFA, decreasing cell death, and improving contraction resumption in CCOs.

Toxicological evaluation of a fish oil concentrate containing Very Long Chain Fatty Acids

Very long chain fatty acids (VLCFA) have a chain length ≥24 carbons. Fish contain low levels of these fatty acids. A commercial oil called EPAX® Evolve 05 with an up-concentration of VLCFAs of approximately 10 times, has been developed as a dietary supplement by Epax Norway AS. A series of toxicological studies were performed using mice and rats to determine the safety and toxicity of repeat dosing with a gavage administered VLCFA formulation. The results suggest transient lipid accumulation in kidneys and liver. Lipid accumulation was seen with the test item and with the soya control but was not dose related. Liver and kidney lipid accumulation, whilst present in 14- day repeat dose study, was absent in a 90-day rat study. No treatment-effect was seen in urine analysis in any of the studies. No treatment-related effects were seen with a functional observation battery, ophthalmological examination, haematology, urine analysis, oestrus cycle, thyroid hormones, organ weight, or histopathology. In the 90-day study the liver enzymes ALP, AST and ALT were statistically significantly increased with test item but within control values. There were no associated histological findings in the liver suggesting there was no toxic effect and the normalisation of values for all liver enzymes in the recovery groups suggests an adaptive response rather than a prevailing toxic response. The no-observed-adverse-effect level (NOAEL) was determined as 1200 mg VLCFA/kg b.w./day.

Plasma C24:0- and C26:0-lysophosphatidylcholines are reliable biomarkers for the diagnosis of peroxisomal β-oxidation disorders

The gold-standard diagnostic test for peroxisomal disorders (PDs) is plasma concentration analysis of very long-chain fatty acids (VLCFAs). However, this method’s time-consuming nature and limitations in cases which present normal VLCFA levels necessitates alternative approaches. The analysis of C26:0-lysophosphatydylcholine (C26:0-LPC) in dried blood spot samples by tandem-mass spectrometry (MS/MS) has successfully been implemented in certain newborn screening programs to diagnose X-linked adrenoleukodystrophy (ALD). However, the diagnostic potential of very long-chain LPCs concentrations in plasma remains poorly understood. This study sought to evaluate the diagnostic performance of C26:0-LPC and other very long-chain LPCs, comparing them to VLCFA analysis in plasma. The study, which included 330 individuals affected by a peroxisomal β-oxidation deficiency and 407 control individuals, revealed that C26:0- and C24:0-LPC concentrations demonstrated the highest diagnostic accuracy (98.8% and 98.4%, respectively), outperforming VLCFA when C26:0/C22:0 and C24:0/C22:0 ratios were combined (98.1%). Combining C24:0- and C26:0-LPC gave the highest sensitivity (99.7%), with ALD females exhibiting notably higher sensitivity compared with the VLCFA ratio combination (98.7% vs. 93.5%, respectively). In contrast, C22:0-LPC exhibited suboptimal performance, primarily due to its low sensitivity (75%), but we identified a potential use to help distinguish between ALD and Zellweger spectrum disorders. In summary, MS/MS analysis of plasma C24:0- and C26:0-LPC concentrations represents a rapid and straightforward approach to diagnose PDs, demonstrating superior diagnostic accuracy, particularly in ALD females, compared with conventional VLCFA biomarkers. We strongly recommend integrating very-long chain LPC plasma analysis in the diagnostic evaluation of individuals suspected of having a PD.

Identification of QTLs associated with very-long chain fatty acid (VLCFA) content via linkage mapping and BSA-seq in peanut.

Three major QTLs qA01, qB04.1 and qB05 for VLCFA content and their corresponding allele-specific markers will benefit peanut low VLCFA breeding, and a candidate gene Arahy.IF1JV3 was predicted. Peanut is a globally significant oilseed crop worldwide, and contains a high content (20%) of saturated fatty acid (SFA) in its seeds. As high level SFA intake in human dietary may increase the cardiovascular disease risk, reducing the SFA content in peanut is crucial for improving its nutritional quality. Half of the SFAs in peanut are very long-chain fatty acids (VLCFA), so reducing the VLCFA content is a feasible strategy to decrease the total SFA content. Luoaowan with extremely low VLCFA (4.80%) was crossed with Jihua16 (8.00%) to construct an F2:4 population. Three major QTLs including qA01, qB04.1 and qB05 for VLCFA content were detected with 4.43 ~ 14.32% phenotypic variation explained through linkage mapping. Meanwhile, three genomic regions on chromosomes B03, B04 and B05 were identified via BSA-seq approach. Two co-localized intervals on chromosomes B04 (100.10 ~ 103.97Mb) and B05 (6.39 ~ 10.90Mb) were identified. With markers developed based on SNP/InDel variations in qA01 between the two parents, the remaining interval was refined to 103.58 ~ 111.14Mb. A candidate gene Arahy.IF1JV3 encoding a β-ketoacyl-CoA synthase was found in qA01, and its expression level in Luoaowan was significantly lower than that in Jihua16. Allele-specific markers targeting qA01, qB04.1 and qB05 were developed and validated in F4 population, and an elite line with high oleic, low VLCFA (5.05%) and low SFA (11.48%) contents was selected. This study initially revealed the genetic mechanism of VLCFA content, built a marker-assisted selection system for low VLCFA breeding, and provided an effective method to decrease the SFA content in peanut.

Differential gene expression and potential regulatory network of fatty acid biosynthesis during fruit and leaf development in yellowhorn (Xanthoceras sorbifolium), an oil-producing tree with significant deployment values.

Xanthoceras sorbifolium (yellowhorn) is a woody oil plant with super stress resistance and excellent oil characteristics. The yellowhorn oil can be used as biofuel and edible oil with high nutritional and medicinal value. However, genetic studies on yellowhorn are just in the beginning, and fundamental biological questions regarding its very long-chain fatty acid (VLCFA) biosynthesis pathway remain largely unknown. In this study, we reconstructed the VLCFA biosynthesis pathway and annotated 137 genes encoding relevant enzymes. We identified four oleosin genes that package triacylglycerols (TAGs) and are specifically expressed in fruits, likely playing key roles in yellowhorn oil production. Especially, by examining time-ordered gene co-expression network (TO-GCN) constructed from fruit and leaf developments, we identified key enzymatic genes and potential regulatory transcription factors involved in VLCFA synthesis. In fruits, we further inferred a hierarchical regulatory network with MYB-related (XS03G0296800) and B3 (XS02G0057600) transcription factors as top-tier regulators, providing clues into factors controlling carbon flux into fatty acids. Our results offer new insights into key genes and transcriptional regulators governing fatty acid production in yellowhorn, laying the foundation for efforts to optimize oil content and fatty acid composition. Moreover, the gene expression patterns and putative regulatory relationships identified here will inform metabolic engineering and molecular breeding approaches tailored to meet biofuel and bioproduct demands.

Protective effect of oleic acid against very long-chain fatty acid-induced apoptosis in peroxisome-deficient CHO cells

Very long-chain fatty acids (VLCFAs) are degraded exclusively in peroxisomes, as evidenced by the accumulation of VLCFAs in patients with certain peroxisomal disorders. Although accumulation of VLCFAs is considered to be associated with health issues, including neuronal degeneration, the mechanisms underlying VLCFAs-induced tissue degeneration remain unclear. Here, we report the toxic effect of VLCFA and protective effect of C18: 1 FA in peroxisome-deficient CHO cells. We examined the cytotoxicity of saturated and monounsaturated VLCFAs with chain-length at C20–C26, and found that longer and saturated VLCFA showed potent cytotoxicity at lower accumulation levels. Furthermore, the extent of VLCFA-induced toxicity was found to be associated with a decrease in cellular C18:1 FA levels. Notably, supplementation with C18:1 FA effectively rescued the cells from VLCFA-induced apoptosis without reducing the cellular VLCFAs levels, implying that peroxisome-deficient cells can survive in the presence of accumulated VLCFA, as long as the cells keep sufficient levels of cellular C18:1 FA. These results suggest a therapeutic potential of C18:1 FA in peroxisome disease and may provide new insights into the pharmacological effect of Lorenzo's oil, a 4:1 mixture of C18:1 and C22:1 FA.

The impact of the GLOSSY2 and GLOSSY2-LIKE BAHD-proteins in affecting the product profile of the maize fatty acid elongase.

The maize glossy2 and glossy2-like genes are homologs, which encode proteins that belong to the BAHD family of acyltransferases. In planta genetic studies have demonstrated that these genes may be involved in the elongation of very long chain fatty acids (VLCFAs) that are precursors of the cuticular wax fraction of the plant cuticle. VLCFAs are synthesized by a fatty acyl-CoA elongase complex (FAE) that consists of four component enzymes. Previously, we functionally identified the maize FAE component enzymes by their ability to complement haploid Saccharomyces cerevisiae strains that carry lethal deletion alleles for each FAE component enzyme. In this study we used these complemented haploid strains and wild-type diploid strains to evaluate whether the co-expression of either GLOSSY2 or GLOSSY2-LIKE with individual maize FAE component enzymes affects the VLCFA product-profile of the FAE system. Wild-type diploid strains produced VLCFAs of up to 28-carbon chain length. Co-expression of GLOSSY2 or GLOSSY2-LIKE with a combination of maize 3-ketoacyl-CoA synthases stimulated the synthesis of longer VLCFAs, up to 30-carbon chain lengths. However, such results could not be recapitulated when these co-expression experiments were conducted in the yeast haploid mutant strains that lacked individual components of the endogenous FAE system. Specifically, lethal yeast mutant strains that are genetically complemented by the expression of maize FAE-component enzymes produce VLCFAs that range between 20- and 26-carbon chain lengths. However, expressing either GLOSSY2 or GLOSSY2-LIKE in these complemented strains does not enable the synthesis of longer chain VLCFAs. These results indicate that the apparent stimulatory role of GLOSSY2 or GLOSSY2-LIKE to enable the synthesis of longer chain VLCFAs in diploid yeast cells may be associated with mixing plant enzyme components with the endogenous FAE complex.

Fatty Acid Metabolism in Peroxisomes and Related Disorders.

One of the functions of peroxisomes is the oxidation of fatty acids (FAs). The importance of this function in our lives is evidenced by the presence of peroxisomal disorders caused by the genetic deletion of proteins involved in these processes. Unlike mitochondrial oxidation, peroxisomal oxidation is not directly linked to ATP production. What is the role of FA oxidation in peroxisomes? Recent studies have revealed that peroxisomes supply the building blocks for lipid synthesis in the endoplasmic reticulum and facilitate intracellular carbon recycling for membrane quality control. Accumulation of very long-chain fatty acids (VLCFAs), which are peroxisomal substrates, is a diagnostic marker in many types of peroxisomal disorders. However, the relationship between VLCFA accumulation and various symptoms of these disorders remains unclear. Recently, we developed a method for solubilizing VLCFAs in aqueous media and found that VLCFA toxicity could be mitigated by oleic acid replenishment. In this chapter, we present the physiological role of peroxisomal FA oxidation and the knowledge obtained from VLCFA-accumulating peroxisome-deficient cells.

Innovative tree-based method for sampling molecular conformations: exploring the ATP-binding cassette subfamily D member 1 (ABCD1) transporter as a case study.

We introduce a novel tree-based method for visualizing molecular conformation sampling. Our method offers enhanced precision in highlighting conformational differences and facilitates the observation of local minimas within proteins fold space. The projection of empirical laboratory data on the tree allows us to create a link between protein conformations and disease relevant data. To demonstrate the efficacy of our approach, we applied it to the ATP-binding cassette subfamily D member 1 (ABCD1) transporter responsible for very long-chain fatty acids (VLCFAs) import into peroxisomes. The genetic disorder called X-linked adrenoleukodystrophy (XALD) is characterized by the accumulation of VLCFA due to pathogenic variants in the ABCD1 gene. Using in silico molecular simulation, we examined the behavior of 16 prevalent mutations alongside the wild-type protein, exploring both inward and outward open forms of the transporter through molecular simulations. We evaluated from resulting trajectories the energy potential related to the ABCD1 interactions with ATP molecules. We categorized XALD patients based on the severity and progression of their disease, providing a unique clinical perspective. By integrating this data into our numerical framework, our study aimed to uncover the molecular underpinnings of XALD, offering new insights into disease progression. As we explored molecular trajectories and conformations resulting from our study, the tree-based method not only contributes valuable insights into XALD but also lays a solid foundation for forthcoming drug design studies. We advocate for the broader adoption of our innovative approach, proposing it as a valuable tool for researchers engaged in molecular simulation studies.

Trade-offs between the accumulation of cuticular wax and jasmonic acid-mediated herbivory resistance in maize.

Plants have evolved complex physical and chemical defense systems that allow them to withstand herbivory infestation. Composed of a complex mixture of very-long-chain fatty acids (VLCFAs) and their derivatives, cuticular wax constitutes the first physical line of defense against herbivores. Here, we report the function of Glossy 8 (ZmGL8), which encodes a 3-ketoacyl reductase belonging to the fatty acid elongase complex, in orchestrating wax production and jasmonic acid (JA)-mediated defenses against herbivores in maize (Zea mays). The mutation of GL8 enhanced chemical defenses by activating the JA-dependent pathway. We observed a trade-off between wax accumulation and JA levels across maize glossy mutants and 24 globally collected maize inbred lines. In addition, we demonstrated that mutants defective in cuticular wax biosynthesis in Arabidopsis thaliana and maize exhibit enhanced chemical defenses. Comprehensive transcriptomic and lipidomic analyses indicated that the gl8 mutant confers chemical resistance to herbivores by remodeling VLCFA-related lipid metabolism and subsequent JA biosynthesis and signaling. These results suggest that VLCFA-related lipid metabolism has a critical role in regulating the trade-offs between cuticular wax and JA-mediated chemical defenses.

Genome-wide Analysis and Functional Identification of KCS Gene Family under Drought and Salt Stresses in Phaseolus vulgaris L

β-ketoacyl-CoA synthase (KCS) is an important enzyme that catalyzes the biosynthesis of very-long-chain fatty acids (VLCFAs). In this study, the genome-wide analysis and functional characterization of the KCS gene family members in common bean (Phaseolus vulgaris L.) plants were conducted, and the response of the identified gene family to abiotic stresses was evaluated. In this study, 19 KCS genes were identified and characterized in the P. vulgaris genome. The molecular weights of these KCS proteins ranged from 49.14 kDa to 60.57 kDa, their amino acid lengths varied from 437 to 534, and their pI values ranged from 8.81 to 9.47, indicating a basic nature. Segmental and tandem duplications were observed in the Pvul-KCS gene family. Phylogenetic analysis revealed that Pvul-KCS proteins clustered into three main groups with Arabidopsis thaliana and Glycine max species. Comparative mapping analysis was also conducted with A. thaliana and G. max. Expression profile comparisons indicated that these genes had different expression levels in common bean varieties and played a role in the plant’s response to biotic and abiotic stresses. This study provides important insights into the biological functions of KCS genes in Phaseolus vulgaris and offers valuable information for improving drought and salt stress tolerance in common beans.

Increased neurotoxicity of high-density lipoprotein secreted from murine reactive astrocytes deficient in a peroxisomal very-long-chain fatty acid transporter Abcd1.

X-linked adrenoleukodystrophy (X-ALD) is a genetic neurodegenerative disorder caused by pathogenic variants in ABCD1, resulting in the accumulation of very-long-chain fatty acids (VLCFAs) in tissues. The etiology of X-ALD is unclear. Activated astrocytes play a pathological role in X-ALD. Recently, reactive astrocytes have been shown to induce neuronal cell death via saturated lipids in high-density lipoprotein (HDL), although how HDL from reactive astrocytes exhibits neurotoxic effects has yet to be determined. In this study, we obtained astrocytes from wild-type and Abcd1-deficient mice. HDL was purified from the culture supernatant of astrocytes, and the effect of HDL on neurons was evaluated in vitro. To our knowledge, this study shows for the first time that HDL obtained from Abcd1-deficient reactive astrocytes induces a significantly higher level of lactate dehydrogenase (LDH) release, a marker of cell damage, from mouse primary cortical neurons as compared to HDL from wild-type reactive astrocytes. Notably, HDL from Abcd1-deficient astrocytes contained significantly high amounts of VLCFA-containing phosphatidylcholine (PC) and LysoPC. Activation of Abcd1-deficient astrocytes led to the production of HDL containing decreased amounts of PC with arachidonic acid in sn-2 acyl moieties and increased amounts of LysoPC, presumably through cytosolic phospholipase A2 α upregulation. These results suggest that compositional changes in PC and LysoPC in HDL, due to Abcd1 deficiency and astrocyte activation, may contribute to neuronal damage. Our findings provide novel insights into central nervous system pathology in X-ALD.

Quantifying resistance to very-long-chain fatty acid-inhibiting herbicides in Amaranthus tuberculatus using a soilless assay.

Resistance to preemergence (PRE) soil-applied herbicides, such as inhibitors of very-long-chain fatty acid (VLCFA) elongases, was documented in two waterhemp [Amaranthus tuberculatus (Moq.) J.D. Sauer] populations (SIR and CHR) from Illinois, USA. To limit the spread of resistant weed populations, rapid detection measures are necessary. Soil-based resistance assays are limited by edaphic factors, application timing, variable seeding depth and rainfall amount. Therefore, cost-effective techniques mitigating effects of edaphic factors that are appropriate for small- to large-scale assays are needed. Our research goal was to identify and quantify resistance to the VLCFA-inhibiting herbicides, S-metolachlor and pyroxasulfone, using a soilless greenhouse assay. Dose-response experiments were conducted under greenhouse conditions with pre-germinated waterhemp seeds planted on the vermiculite surface, which had been saturated with S-metolachlor (0.015-15 μM), pyroxasulfone (0.0005-1.5 μM), or S-metolachlor plus the cytochrome P450 (P450) inhibitor, malathion. Lethal dose estimates of 50% (LD50) and growth reduction of 50% (GR50) were calculated for S-metolachlor and pyroxasulfone PRE and used to determine resistance indices (RI) for resistant populations (CHR and SIR) relative to sensitive populations, SEN and ACR. RI values for S-metolachlor using LD50 values calculated relative to SEN and ACR were 17.2 and 15.2 (CHR) or 11.5 and 10.1 (SIR), while RI values for pyroxasulfone using LD50 values calculated relative to SEN and ACR were 3.8 and 3.1 (CHR) or 4.8 and 3.8 (SIR). Malathion decreased the GR50 of S-metolachlor to a greater degree in CHR compared to ACR, consistent with P450 involvement in S-metolachlor resistance in CHR. Results from these soilless assays are in accord with previous findings in soil-based systems that demonstrate CHR and SIR are resistant to S-metolachlor and pyroxasulfone. This method provides an effective, reproducible alternative to soil-based systems for studying suspected PRE herbicide-resistant populations and will potentially assist in identifying non-target-site resistance mechanisms.

Very long chain fatty acid–inhibiting herbicides: Current uses, site of action, herbicide-resistant weeds, and future

Abstract The herbicides that inhibit very-long-chain fatty acid (VLCFA) elongases are primarily used for residual weed control in corn, barley, oat, sorghum, soybean, sugarcane, certain vegetable crops, and wheat production fields in the United States. They act primarily by inhibiting shoot development of susceptible species, preventing weed emergence and growth. The objectives of this review were to summarize 1) the chemical family of VLCFA-inhibiting herbicides and their use in the United States, 2) the VLCFA biosynthesis in plants and their site of action, 3) VLCFA-inhibitor resistant weeds and their mechanism of resistance, and 4) the future of VLCFA-inhibiting herbicides. After their reclassification as Group 15 herbicides to include shoot growth-inhibiting herbicides (Group 8), the VLCFA-inhibiting herbicides are currently represented by eight chemical families (benzofurans, thiocarbamates, α-chloroacetamides, α-oxyacetamides, azolyl-carboxamides, isoxazolines, α-thioacetamides, and oxiranes). On average, VLCFA-inhibiting herbicides are applied once a year to both corn and soybean crops in the United States with acetochlor and S-metolachlor being the most used VLCFA-inhibiting herbicides in corn and soybean production, respectively. The site of action of Group 15 herbicides results from inhibition of the VLCFA synthase, which is encoded by several fatty acid elongase (FAE1)-like genes in VLCFA elongase complex in an endoplasmic reticulum. The VLCFA synthase is a condensing enzyme, and relies on a conserved, reactive cysteinyl sulfur in its active site that performs a nucleophilic attack on either the natural substrate (fatty acyl-CoA) or the herbicide. As of August 2023, 13 weed species have been documented to be resistant to VLCFA inhibitors, including 11 monocot weeds and two dicot weeds (Palmer amaranth and waterhemp). The isoxazolines (pyroxasulfone and fenoxasulfone) are the most recently (2014) discovered VLCFA-inhibiting herbicides. Although the intensity of VLCFA-inhibitor-directed discovery efforts has decreased over the past decade, this biochemical pathway remains a viable mechanistic target for the discovery of herbicide premixes and a valuable component of them.

Immune response of BV-2 microglial cells is impacted by peroxisomal beta-oxidation.

Microglia are crucial for brain homeostasis, and dysfunction of these cells is a key driver in most neurodegenerative diseases, including peroxisomal leukodystrophies. In X-linked adrenoleukodystrophy (X-ALD), a neuroinflammatory disorder, very long-chain fatty acid (VLCFA) accumulation due to impaired degradation within peroxisomes results in microglial defects, but the underlying mechanisms remain unclear. Using CRISPR/Cas9 gene editing of key genes in peroxisomal VLCFA breakdown (Abcd1, Abcd2, and Acox1), we recently established easily accessible microglial BV-2 cell models to study the impact of dysfunctional peroxisomal β-oxidation and revealed a disease-associated microglial-like signature in these cell lines. Transcriptomic analysis suggested consequences on the immune response. To clarify how impaired lipid degradation impacts the immune function of microglia, we here used RNA-sequencing and functional assays related to the immune response to compare wild-type and mutant BV-2 cell lines under basal conditions and upon pro-inflammatory lipopolysaccharide (LPS) activation. A majority of genes encoding proinflammatory cytokines, as well as genes involved in phagocytosis, antigen presentation, and co-stimulation of T lymphocytes, were found differentially overexpressed. The transcriptomic alterations were reflected by altered phagocytic capacity, inflammasome activation, increased release of inflammatory cytokines, including TNF, and upregulated response of T lymphocytes primed by mutant BV-2 cells presenting peptides. Together, the present study shows that peroxisomal β-oxidation defects resulting in lipid alterations, including VLCFA accumulation, directly reprogram the main cellular functions of microglia. The elucidation of this link between lipid metabolism and the immune response of microglia will help to better understand the pathogenesis of peroxisomal leukodystrophies.

Ataxia with giant axonopathy in Acbd5-deficient mice halted by adeno-associated virus gene therapy.

Acyl-CoA binding domain containing 5 (ACBD5) is a critical player in handling very long chain fatty acids (VLCFA) en route for peroxisomal β-oxidation. Mutations in ACBD5 lead to the accumulation of VLCFA and patients present retinal dystrophy, ataxia, psychomotor delay and a severe leukodystrophy. Using CRISPR/Cas9, we generated and characterized an Acbd5 Gly357* mutant allele. Gly357* mutant mice recapitulated key features of the human disorder, including reduced survival, impaired locomotion and reflexes, loss of photoreceptors, and demyelination. The ataxic presentation of Gly357* mice involved the loss of cerebellar Purkinje cells and a giant axonopathy throughout the CNS. Lipidomic studies provided evidence for the extensive lipid dysregulation caused by VLCFA accumulation. Following a proteomic survey, functional studies in neurons treated with VLCFA unravelled a deregulated cytoskeleton with reduced actin dynamics and increased neuronal filopodia. We also show that an adeno-associated virus-mediated gene delivery ameliorated the gait phenotypes and the giant axonopathy, also improving myelination and astrocyte reactivity. Collectively, we established a mouse model with significance for VLCFA-related disorders. The development of relevant neuropathological outcomes enabled the understanding of mechanisms modulated by VLCFA and the evaluation of the efficacy of preclinical therapeutic interventions.

Genome-wide identification and expression analysis of the KCS gene family in soybean (Glycine max) reveal their potential roles in response to abiotic stress.

Very long chain fatty acids (VLCFAs) are fatty acids with chain lengths of 20 or more carbon atoms, which are the building blocks of various lipids that regulate developmental processes and plant stress responses. 3-ketoacyl-CoA synthase encoded by the KCS gene is the key rate-limiting enzyme in VLCFA biosynthesis, but the KCS gene family in soybean (Glycine max) has not been adequately studied thus far. In this study, 31 KCS genes (namely GmKCS1 - GmKCS31) were identified in the soybean genome, which are unevenly distributed on 14 chromosomes. These GmKCS genes could be phylogenetically classified into seven groups. A total of 27 paralogous GmKCS gene pairs were identified with their Ka/Ks ratios indicating that they had undergone purifying selection during soybean genome expansion. Cis-acting element analysis revealed that GmKCS promoters contained multiple hormone- and stress-responsive elements, indicating that GmKCS gene expression levels may be regulated by various developmental and environmental stimuli. Expression profiles derived from RNA-seq data and qRT-PCR experiments indicated that GmKCS genes were diversely expressed in different organs/tissues, and many GmKCS genes were found to be differentially expressed in the leaves under cold, heat, salt, and drought stresses, suggesting their critical role in soybean resistance to abiotic stress. These results provide fundamental information about the soybean KCS genes and will aid in their further functional elucidation and exploitation.

OROSOMUCOID PROTEIN 1 regulation of sphingolipid synthesis is required for nodulation in Aeschynomene evenia.

Legumes establish symbiotic interactions with nitrogen-fixing rhizobia that are accommodated in root-derived organs known as nodules. Rhizobial recognition triggers a plant symbiotic signaling pathway that activates 2 coordinated processes: infection and nodule organogenesis. How these processes are orchestrated in legume species utilizing intercellular infection and lateral root base nodulation remains elusive. Here, we show that Aeschynomene evenia OROSOMUCOID PROTEIN 1 (AeORM1), a key regulator of sphingolipid biosynthesis, is required for nodule formation. Using A. evenia orm1 mutants, we demonstrate that alterations in AeORM1 function trigger numerous early aborted nodules, defense-like reactions, and shorter lateral roots. Accordingly, AeORM1 is expressed during lateral root initiation and elongation, including at lateral root bases where nodule primordium form in the presence of symbiotic bradyrhizobia. Sphingolipidomics revealed that mutations in AeORM1 lead to sphingolipid overaccumulation in roots relative to the wild type, particularly for very long-chain fatty acid-containing ceramides. Taken together, our findings reveal that AeORM1-regulated sphingolipid homeostasis is essential for rhizobial infection and nodule organogenesis, as well as for lateral root development in A. evenia.

CytogeneticsRapid Resolution of Medically Relevant Polyunsaturated, Very Long-, Odd-, and Branched-Chain Fatty Acid Methyl Esters

Abstract Fatty acids play an important role in human health and disease. Nearly 100 years ago, the Burrs demonstrated that polyunsaturated fatty acids (PUFAs) were essential for development; subsequent work uncovered the role of PUFAs as precursors to important signaling molecules such as prostaglandins, leukotrienes, and thromboxanes. Very long chain fatty acids (VLCFAs) originally sparked interest over 40 years ago for being elevated in humans with peroxisomal disorders. More recent studies have shown that VLCFAs are elevated in healthy human controls, compared to their diabetic counterparts. In a similar vein, odd chain fatty acids (OCFAs) and branched-chain fatty acids (BCFAs) of the iso and anteiso variety are higher in humans with insulin sensitivity than in insulin resistant individuals. These families of fatty acids are most frequently analyzed as their fatty acid methyl esters (FAMEs) by gas chromatography (GC). Regrettably, even recently published methods resolving BCFAs from their linear correlates have run-times in excess of an hour and, in some cases, over 100 minutes. Objective: The goal of this study was to decrease the GC run-time for the analysis of FAMEs relevant to human health and disease. Methods: Baseline resolution of FAMEs required careful combination of the right gas chromatograph, column dimensions, stationary phase, carrier gas, and temperature programming. Results: We cleanly resolved the FAMEs of all common polyunsaturated, very long-, odd-, and branched-chain fatty acids with baseline separation in only ~15 minutes – a 4-fold improvement over many existing methods. Conclusion: This method will significantly improve analysis of fatty acids in health and disease, especially in large-scale, clinical studies, by quartering the run time necessary to resolve PUFAs, VLCFAs, OCFAs, and BCFAs.

Fatty acid analysis in serum of patients with elevated lipoprotein(a) and cardiovascular disease undergoing lipoprotein apheresis

Fatty acid analysis in serum of patients with elevated lipoprotein(a) and cardiovascular disease undergoing lipoprotein apheresis