3-hydroxyacyl-CoA Dehydrogenase Research Articles

Enzymatic Metabolic Switches of Astrocyte Response to Lipotoxicity as Potential Therapeutic Targets for Nervous System Diseases.

Astrocytes play a pivotal role in maintaining brain homeostasis. Recent research has highlighted the significance of palmitic acid (PA) in triggering pro-inflammatory pathways contributing to neurotoxicity. Furthermore, Genomic-scale metabolic models and control theory have revealed that metabolic switches (MSs) are metabolic pathway regulators by potentially exacerbating neurotoxicity, thereby offering promising therapeutic targets. Herein, we characterized these enzymatic MSs in silico as potential therapeutic targets, employing protein-protein and drug-protein interaction networks alongside structural characterization techniques. Our findings indicate that five MSs (P00558, P04406, Q08426, P09110, and O76062) were functionally linked to nervous system drug targets and may be indirectly regulated by specific neurological drugs, some of which exhibit polypharmacological potential (e.g., Trifluperidol, Trifluoperazine, Disulfiram, and Haloperidol). Furthermore, four MSs (P00558, P04406, Q08426, and P09110) feature ligand-binding or allosteric cavities with druggable potential. Our results advocate for a focused exploration of P00558 (phosphoglycerate kinase 1), P04406 (glyceraldehyde-3-phosphate dehydrogenase), Q08426 (peroxisomal bifunctional enzyme, enoyl-CoA hydratase, and 3-hydroxyacyl CoA dehydrogenase), P09110 (peroxisomal 3-ketoacyl-CoA thiolase), and O76062 (Delta(14)-sterol reductase) as promising targets for the development or repurposing of pharmacological compounds, which could have the potential to modulate lipotoxic-altered metabolic pathways, offering new avenues for the treatment of related human diseases such as neurological diseases.

Identification and analysis of immunogenicity and immunotherapy efficacy by fatty acid genes: a novel prognostic features of lumbar disc herniation and Mendelian randomization analysis

ABSTRACT Background: Sciatica is a phrase used to describe radiating leg discomfort. The most common cause is lumbar disc herniation (LDH), which is considered to start in the nucleus pulposus. Advancements in lipidomics and metabolomics have unveiled the complex role of fatty acid metabolism (FAM) in both healthy and pathological states. However, the specific roles of fatty acid metabolism-related genes (FAMGs) in shaping therapeutic approaches, especially in LDH, remain largely unexplored and are a subject of ongoing research. Methods: The junction of the weighted correlation network analysis (WGCNA) test with 6 FAMGs enabled the finding of FAMGs. Gene set variation analysis (GSVA) was used to identify the possible biological activities and pathways of FAMGs. LASSO was used to determine diagnostic effectiveness of the four FAMGs in diagnosing LDH. GSE124272, GSE147383, GSE150408, and GSE153761 were utilized to confirm the levels of expression of four FAMGs. Results: Four FAMGs were discovered [Acyl-CoA Thioesterase 4 (ACOT4), Cytochrome P450 Family 4 Subfamily A Member 11 (CYP4A11), Acyl-CoA Dehydrogenase Long Chain (ACADL), Enoyl-CoA Hydratase and 3-Hydroxyacyl CoA Dehydrogenase (EHHADH)] For biological function analysis, mhc class ib receptor activity, response to thyroxine, response to l phenylalanine derivative were emphasized. Conclusions: FAMGs can help with prognosis and immunology, and provide evidence for fatty acid metabolism-related targeted therapeutics. In LDH, FAMGs and their interactions with immune cells might be therapeutic targets.

Early diagnosis and treatment by newborn screening (NBS) or family history is associated with improved visual outcomes for long-chain 3-hydroxyacylCoA dehydrogenase deficiency (LCHADD) chorioretinopathy.

Long chain 3-hydroxyacyl-CoA dehydrogenase (LCHADD) is the only fatty acid oxidation disorder to develop a progressive chorioretinopathy resulting in vision loss; newborn screening (NBS) for this disorder began in the United States around 2004. We compared visual outcomes among 40 participants with LCHADD or trifunctional protein deficiency diagnosed symptomatically to those who were diagnosed via NBS or a family history. Participants completed ophthalmologic testing including measures of visual acuity, electroretinograms (ERG), fundal imaging, contrast sensitivity, and visual fields. Records were reviewed to document medical and treatment history. Twelve participants presented symptomatically with hypoglycemia, failure to thrive, liver dysfunction, cardiac arrest, or rhabdomyolysis. Twenty eight were diagnosed by NBS or due to a family history of LCHADD. Participants diagnosed symptomatically were older but had similar percent males and genotypes as those diagnosed by NBS. Treatment consisted of fasting avoidance, dietary long-chain fat restriction, MCT, C7, and/or carnitine supplementation. Visual acuity, rod- and cone-driven amplitudes on ERG, contrast sensitivity scores, and visual fields were all significantly worse among participants diagnosed symptomatically compared to NBS. In mixed-effects models, both age and presentation (symptomatic vs. NBS) were significant independent factors associated with visual outcomes. This suggests that visual outcomes were improved by NBS, but there was still lower visual function with advancing age in both groups. Early diagnosis and treatment by NBS is associated with improved visual outcomes and retinal function compared to participants who presented symptomatically. Despite the impact of early intervention, chorioretinopathy was greater with advancing age, highlighting the need for novel treatments.

Cardiac phenotype in adolescents and young adults with long-chain 3-hydroxyacyl CoA dehydrogenase (LCHAD) deficiency

PurposeLong-chain 3-hydroxyacyl-coenzyme A dehydrogenase deficiency (LCHADD) is a rare fatty acid oxidation disorder characterized by recurrent episodes of metabolic decompensation and rhabdomyolysis, as well as retinopathy, peripheral neuropathy, and cardiac involvement, such as infantile dilated cardiomyopathy. Because LCHADD patients are surviving longer, we sought to characterize LCHADD-associated major cardiac involvement in adolescence and young adulthood. MethodsA retrospective cohort of 16 adolescent and young adult participants with LCHADD was reviewed for cardiac phenotype. ResultsMajor cardiac involvement occurred in 9 of 16 participants, including sudden death, out-of-hospital cardiac arrest, acute cardiac decompensations with heart failure and/or in-hospital cardiac arrest, end-stage dilated cardiomyopathy, and moderate restrictive cardiomyopathy. Sudden cardiac arrest was more common in males and those with a history of infant cardiomyopathy. ConclusionThe cardiac manifestations of LCHADD in adolescence and early adulthood are complex and distinct from the phenotype seen in infancy. Life-threatening arrhythmia occurs at substantial rates in LCHADD, often in the absence of metabolic decompensation or rhabdomyolysis. The potential risk factors identified here—male sex and history of infant cardiomyopathy—may hint at strategies for risk stratification and possibly the prevention of these events.

Cardiomyocyte-specific deletion of GCN5L1 reduces lysine acetylation and attenuates diastolic dysfunction in aged mice by improving cardiac fatty acid oxidation.

Cardiac mitochondrial dysfunction is a critical contributor to the pathogenesis of aging and many age-related conditions. As such, complete control of mitochondrial function is critical to maintain cardiac efficiency in the aged heart. Lysine acetylation is a reversible post-translational modification shown to regulate several mitochondrial metabolic and biochemical processes. In the present study, we investigated how mitochondrial lysine acetylation regulates fatty acid oxidation (FAO) and cardiac function in the aged heart. We found a significant increase in mitochondrial protein acetylation in the aged heart which correlated with increased level of mitochondrial acetyltransferase-related protein GCN5L1. We showed that acetylation status of several fatty acid and glucose oxidation enzymes (long-chain acyl-coenzyme A dehydrogenase, hydroxyacyl-coA dehydrogenase, and pyruvate dehydrogenase) were significantly up-regulated in aged heart which correlated with decreased enzymatic activities. Using a cardiac-specific GCN5L1 knockout (KO) animal model, we showed that overall acetylation of mitochondrial proteins was decreased in aged KO animals, including FAO proteins which led to improved FAO activity and attenuated cardiac diastolic dysfunction observed in the aged heart. Together, these findings indicate that lysine acetylation regulates FAO in the aged heart which results in improved cardiac diastolic function and this is in part regulated by GCN5L1.

Proteomic study on nintedanib in gastric cancer cells.

Gastric cancer is a very common gastrointestinal tumor with a high mortality rate. Nintedanib has been shown to significantly reduce tumor cell proliferation and increase apoptosis in gastric cancer cells in vitro. However, its systemic action mechanism on gastric cancer cells remains unclear. A high-throughput proteomic approach should help identify the potential mechanisms and targets of nintedanib on gastric cancer cells. The effects of nintedanib on the biological behavior of gastric cancer cells were evaluated. A cytotoxic proliferation assay was performed to estimate the half maximal inhibitory concentration (IC50). AGS cells were divided into control, and nintedanib-treated groups (5 µM, 48 h), and differential protein expression was investigated using tandem mass tags (TMT) proteomics. The molecular mechanisms of these differentially expressed proteins and their network interactions were then analyzed using bioinformatics, and potential nintedanib targets were identified. This study identified 845 differentially expressed proteins in the nintedanib-treated group (compared to the control group), comprising 526 up-regulated and 319 down-regulated proteins. Bioinformatics analysis revealed that the differentially expressed proteins were primarily enriched in biological pathways for branched-chain amino acid metabolism, steroid biosynthesis, propionate metabolism, fatty acid metabolism, lysosome, peroxisome, and ferroptosis. Key driver analysis revealed that proteins, such as enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase (EHHADH), isocitrate dehydrogenase 1 (IDH1), acyl-CoA oxidase 1 (ACOX1), acyl-CoA oxidase 2 (ACOX2), acyl-CoA oxidase 3 (ACOX3), and acetyl-CoA acyltransferase 1 (ACAA1) could be linked with nintedanib action. Nintedanib inhibits the proliferation, invasion, and metastasis of gastric cancer cells. The crossover pathways and protein networks predicted by proteomics should provide more detailed molecular information enabling the use of nintedanib against gastric cancer.

Identification of a new C-23 metabolite in sterol degradation of Mycobacterium neoaurum HGMS2 and analysis of its metabolic pathways

Mycobacterium neoaurum has the ability to produce steroidal intermediates known as 22-hydroxy-23, 24-bisnorchol-4-en-3-one (BA) upon the knockout of the genes for either the hydroxyacyl-CoA dehydrogenase (Hsd4A) or acyl-CoA thiolase (FadA5). In a previous study, we discovered a novel metabolite in the fermentation products when the fadA5 gene was deleted. This research aims to elucidate the metabolic pathway of this metabolite through structural identification, homologous sequence analysis of the fadA5 gene, phylogenetic tree analysis of M. neoaurum HGMS2, and gene knockout. Our findings revealed that the metabolite is a C23 metabolic intermediate, named 24-norchol-4-ene-3, 22-dione (designated as 3-OPD). It is formed when a thioesterase (TE) catalyzes the formation of a β-ketonic acid by removing CoA from the side chain of 3, 22-dioxo-25, 26-bisnorchol-4-ene-24-oyl CoA (22-O-BNC-CoA), followed by spontaneously undergoing decarboxylation. These results have the potential to contribute to the development of novel steroid intermediates.

Consistent changes in muscle metabolism underlie dive performance across multiple lineages of diving ducks.

Diving animals must sustain high activity with limited O2 stores to successfully capture prey. Studies suggest that increasing body O2 stores supports breath-hold diving, but less is known about metabolic specializations that underlie underwater locomotion. We measured maximal activities of 10 key enzymes in locomotory muscles (gastrocnemius and pectoralis) to identify biochemical changes associated with diving in pathways of oxidative and substrate-level phosphorylation and compared them across three groups of ducks-the longest diving sea ducks (eight spp.), the mid-tier diving pochards (three spp.) and the non-diving dabblers (five spp.). Relative to dabblers, both diving groups had increased activities of succinate dehydrogenase and cytochrome c oxidase, and sea ducks further showed increases in citrate synthase (CS) and hydroxyacyl-CoA dehydrogenase (HOAD). Both diving groups had relative decreases in capacity for anaerobic metabolism (lower ratio of lactate dehydrogenase to CS), with sea ducks also showing a greater capacity for oxidative phosphorylation and lipid oxidation (lower ratio of pyruvate kinase to CS, higher ratio of HOAD to hexokinase). These data suggest that the locomotory muscles of diving ducks are specialized for sustaining high rates of aerobic metabolism, emphasizing the importance of body O2 stores for dive performance in these species.

IFI27 Integrates Succinate and Fatty Acid Oxidation to Promote Adipocyte Thermogenic Adaption.

Mitochondria are the pivot organelles to control metabolism and energy homeostasis. The capacity of mitochondrial metabolic adaptions to cold stress is essential for adipocyte thermogenesis. How brown adipocytes keep mitochondrial fitness upon a challenge of cold-induced oxidative stress has not been well characterized. This manuscript shows that IFI27 plays an important role in cristae morphogenesis, keeping intact succinate dehydrogenase (SDH) function and active fatty acid oxidation to sustain thermogenesis in brown adipocytes. IFI27 protein interaction map identifies SDHB and HADHA as its binding partners. IFI27 physically links SDHB to chaperone TNF receptor associated protein 1 (TRAP1), which shields SDHB from oxidative damage-triggered degradation. Moreover, IFI27 increases hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit alpha (HADHA) catalytic activity in β-oxidation pathway. The reduced SDH level and fatty acid oxidation in Ifi27-knockout brown fat results in impaired oxygen consumption and defective thermogenesis. Thus, IFI27 is a novel regulator of mitochondrial metabolism and thermogenesis.

1630-P: Reduced Fatty Acid Oxidation Does Not Prevent Intralipid-Induced Peripheral Insulin Resistance in Humans

Mitochondrial handling of excess lipid substrate is thought to be an important determinant of insulin resistance. Evidence from animal models support insulin signaling defects resulting from either intra-cellular lipid accumulation or by mitochondrial dysfunction and altered fatty acid oxidation (FAO) flux. To explore the relationship between FAO and insulin sensitivity, we measured the change in peripheral glucose disposal (Rd) during a 5-hour hyperinsulinemic euglycemic clamp with co-infusion of a control glycerol solution versus a 20% intralipid solution in 18 subjects with an inherited defect in FAO (FAOD; including Carnitine Palmitoyltransferase 2, Very long-chain, medium-chain or long-chain 3-hydroxy AcylcoA Dehydrogenase Deficiencies) and 18 age, sex, and weight-matched normal healthy controls. Rd was similar between groups during the glycerol control clamp. Intramyocellular lipid (IMCL) content as measured by MRS increased after the 5 hour intralipid infusion in controls but not in participants with FAOD. Plasma free fatty acids during intralipid infusion were higher in FAOD compared to controls suggesting infused lipid remained in circulation. Muscle fiber type and expression of lipid transporters CD36 and FATP1 were similar in biopsy samples between groups and cannot explain decreased lipid uptake into muscle among FAOD subjects. However, intralipid suppressed Rd equally in subjects with FAOD and controls inducing peripheral insulin resistance in both groups. Impaired FAO decreased lipid accumulation in the muscle during intralipid infusion, but despite lower IMCL, subjects with FAOD developed peripheral insulin resistance similar to controls. Increased IMCL is not essential for, nor is reduced FAO flux protective against, the development of peripheral insulin resistance during intralipid infusion. Disclosure M.B.Gillingham: None. J.Q.Purnell: Advisory Panel; Boehringer Ingelheim International GmbH, Novo Nordisk. A.N.Gregor: None. O.Varlamov: None. J.J.Robino: None. C.E.Mccurdy: None. K.T.Greyslak: None. D.Choi: None. E.Baetscher: Consultant; Biogen. W.Rooney: Consultant; Ultragenix, Research Support; Revalesio. Funding National Institutes of Health (DK102813)

Relative Activities of the β-Ketoacyl-CoA and Acyl-CoA Reductases Influence the Product Profile and Flux in a Reversed β-Oxidation Pathway

The β-oxidation pathway, normally involved in the catabolism of fatty acids, can be functionally made to act as a fermentative, iterative, elongation pathway when driven by the activity of a trans-enoyl-CoA reductase (TER). The terminal acyl-CoA reduction to alcohol can occur on substrates with varied chain lengths, leading to a broad distribution of fermentation products in vivo. Tight control of the average chain length and product profile is desirable, as the chain length greatly influences the molecular properties and the commercial value. Lacking a termination enzyme with a narrow chain length preference, we sought alternative factors that could influence the product profile and pathway flux in the iterative pathway. In this study, we reconstituted the reversed β-oxidation (R-βox) pathway in vitro with a purified tri-functional complex (FadBA) responsible for the thiolase, enoyl-CoA hydratase, and hydroxyacyl-CoA dehydrogenase activities, a TER, and an acyl-CoA reductase. Using this system, we determined the rate-limiting step of the elongation cycle and demonstrated that by controlling the ratio of these three enzymes and the ratio of NADH and NADPH, we can influence the average chain length of the alcohol product profile.

Replacing Fish Meal with Hydrolyzed Collagen Derived from Fish By-Products Improved Muscle Quality and Glycolipid Metabolism of Triploid Crucian Carp.

Fish by-products are rich in collagen. Hydrolyzed collagen derived from fish by-products was used to replace fish meal to evaluate the effects on muscle quality and glycolipid metabolism of juvenile triploid crucian carp. A total of 240 juvenile fish with body weight of 10.01 ± 0.02 g were divided into four groups and fed four diets for 66 days: fish meal (FM) replaced with hydrolyzed collagen (HC) in 0% (Control), 2% (2% HC), 4% (4% HC), and 6% (6% HC), respectively. The results were as follows: The increased proportion of fish meal replaced with hydrolyzed collagen linearly and quadratically decreased the specific growth rate (SGR) of triploid crucian carp (p < 0.05). Compared with the control group, the SGR and intestinal α-amylase, trypsin and lipase activities in the 4% and 6% HC groups significantly decreased (p < 0.05), while there was no significant difference between the control and 2% HC groups (p > 0.05). Total umami amino acids content, chewiness and myofiber density of muscle in the 4% and 6% HC groups, as well as the essential fatty acids content in all HC groups increased significantly (p < 0.05). All HC groups significantly increased the serum glutathione peroxidase (GSH-Px) activity and decreased the serum malondialdehyde (MDA) content (p < 0.05). When the replacement amount reached 4%, the serum glucose and liver glycogen content, the liver and serum triglyceride (TG) content, and serum total cholesterol (T-CHO) content were significantly reduced (p < 0.05). In addition, the expression levels of insulin-like growth factor-1 (IGF-1) of the liver in all HC groups and lipolysis-related genes (lipoprotein lipase (LPL), carnitine O-palmitoyltransferase 1 (CPT 1) and hydroxyacyl-coenzyme A dehydrogenase (HADH)) of the liver in the 6% of HC group increased significantly (p < 0.05), and the expression levels of lipogenesis-related genes (fatty acid synthase (FAS) and sterol regulatory element-binding protein 1 (SREBP 1)) of the liver in the 4% HC and 6% HC groups decreased significantly (p < 0.05). In conclusion, the replacement of 2% fish meal with hydrolyzed collagen had no negative effects on the growth of triploid crucian carp, while the replacement of 4% fish meal with hydrolyzed collagen decreased SGR, but improved the muscle quality and decreased glycolipid levels. The maximum proportion of hydrolyzed collagen replacing fish meal should not exceed 4%.

ALDH2 attenuates myocardial pyroptosis through breaking down Mitochondrion-NLRP3 inflammasome pathway in septic shock.

Cell survival or death is critical for cardiac function. Myocardial pyroptosis, as a newly recognized programmed cell death, remains poorly understood in sepsis. In this study, we evaluated the effect of aldehyde dehydrogenase (ALDH2) on myocardial pyroptosis and revealed the underlying mechanisms in sepsis. We established a septic shock mice model by intraperitoneal injection of Lipopolysaccharide (LPS, 15mg/kg) 12h before sacrifice. It was found that aldehyde dehydrogenase significantly inhibited NOD-like receptor protein 3 (NLRP3) inflammasome activation and Caspase-1/GSDMD-dependent pyroptosis, which remarkably improved survival rate and septic shock-induced cardiac dysfunction, relative to the control group. While aldehyde dehydrogenase knockout or knockdown significantly aggravated these phenomena. Intriguingly, we found that aldehyde dehydrogenase inhibited LPS-induced deacetylation of Hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex α subunit (HADHA) by suppressing the translocation of Histone deacetylase 3 (HDAC3) from nuclei to mitochondria. Acetylated HADHA is essential for mitochondrial fatty acid β-oxidation, and its interruption can result in accumulation of toxic lipids, induce mROS and cause mtDNA and ox-mtDNA release. Our results confirmed the role of Histone deacetylase 3 and HADHA in NOD-like receptor protein 3 inflammasome activation. Hdac3 knockdown remarkedly suppressed NOD-like receptor protein 3 inflammasome and pyroptosis, but Hadha knockdown eliminated the effect. aldehyde dehydrogenase inhibited the translocation of Histone deacetylase 3, protected ac-HADHA from deacetylation, and significantly reduced the accumulation of toxic aldehyde, and inhibited mROS and ox-mtDNA, thereby avoided NOD-like receptor protein 3 inflammasome activation and pyroptosis. This study provided a novel mechanism of myocardial pyroptosis through mitochondrial Histone deacetylase 3/HADHA- NOD-like receptor protein 3 inflammasome pathway and demonstrated a significant role of aldehyde dehydrogenase as a therapeutic target for myocardial pyroptosis in sepsis.

Fatty acid-sensing mechanisms in the hypothalamus of European sea bass (Dicentrarchus labrax): The potential role of monounsaturated and polyunsaturated fatty acids

This study aimed to evaluate the hypothalamus fatty acid (FA)-sensing mechanisms response to different FA in European sea bass. For that purpose, fish (body weight of 90 g) were intraperitoneally (IP) injected (time 0 h) with five long-chain unsaturated fatty acids, namely, docosahexaenoic acid (DHA; C22:5n3); eicosapentaenoic acid (EPA; C20:4n3); α-linolenic (ALA; C18:3n3); linoleic acid (LA; C18:2n6) and oleic acid (OA; C18:1n9) at a dose of 300 μg kg−1, or with 0.9% saline solution (control). Feed intake (FI) was recorded at 3, 6, and 24 h after the IP injection. One week later, fish were IP injected with the same FA, and the hypothalamus was collected 3 h after the IP injection for measurement of molecules related to FI regulation and FA-sensing mechanisms. Cumulative FI (g/kg/day) was not affected by treatments. However, compared to the control, FI increased with the OA treatment at 6 h after the IP injection. FI decreased with mealtime in the DHA and LA groups. Gene expression of orexigenic (npy/agrp) and anorexigenic (cart2/pomc1) neurons was not affected by the FA treatments. Attending the enzymes involved in the FA-sensing mechanisms activation, compared to the control carnitine palmitoyltransferase I (CPT1) and ATP citrate lyase (ACLY) activity were not affected by FA treatments. Contrarily the key enzymes of lipid metabolisms, malic enzyme and hydroxyacylCoA dehydrogenase was higher in fish that received the EPA and OA treatment, than fish treated to the control. Overall, the results of the present study indicate that gene expression of orexigenic and anorexigenic neurons was not affected at 3 h after IP injection with different FA. However, the activity of key enzymes of lipid metabolism was differently affected by circulating FA, indicating that FA-sensing mechanisms respond to different FA. Further studies are required involving different sampling times to further characterize the response of FA-sensing mechanisms to FA. These findings may be of relevance to the aquaculture industry in an era where alternative lipid sources are being increasingly used.

RNA-Seq Analysis Identifies Differentially Expressed Genes in the Longissimus dorsi of Wagyu and Chinese Red Steppe Cattle.

Meat quality has a close relationship with fat and connective tissue; therefore, screening and identifying functional genes related to lipid metabolism is essential for the production of high-grade beef. The transcriptomes of the Longissimus dorsi muscle in Wagyu and Chinese Red Steppe cattle, breeds with significant differences in meat quality and intramuscular fat deposition, were analyzed using RNA-seq to screen for candidate genes associated with beef quality traits. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the 388 differentially expressed genes (DEGs) were involved in biological processes such as short-chain fatty acid metabolism, regulation of fatty acid transport and the peroxisome proliferator-activated receptor (PPAR) signaling pathway. In addition, crystallin alpha B (CRYAB), ankyrin repeat domain 2 (ANKRD2), aldehyde dehydrogenase 9 family member A1 (ALDH9A1) and enoyl-CoA hydratase and 3-hydroxyacyl CoA dehydrogenase (EHHADH) were investigated for their effects on intracellular triglyceride and fatty acid content and their regulatory effects on genes in lipogenesis and fatty acid metabolism pathways. This study generated a dataset from transcriptome profiling of two cattle breeds, with differing capacities for fat-deposition in the muscle, and revealed molecular evidence that CRYAB, ANKRD2, ALDH9A1 and EHHADH are related to fat metabolism in bovine fetal fibroblasts (BFFs). The results provide potential functional genes for maker-assisted selection and molecular breeding to improve meat quality traits in beef cattle.

Hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit beta gene as a tumour suppressor in stomach adenocarcinoma.

Stomach adenocarcinoma (STAD) is the most common type of gastric cancer. In this study, the functions and potential mechanisms of hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit beta (HADHB) in STAD were explored. Different bioinformatics analyses were performed to confirm HADHB expression in STAD. HADHB expression in STAD tissues and cells was also evaluated using western blot, qRT-PCR, and immunohistochemistry. Further, the viability, proliferation, colony formation, cell cycle determination, migration, and wound healing capacity were assessed, and the effects of HADHB on tumour growth, cell apoptosis, and proliferation in nude mice were determined. The upstream effector of HADHB was examined using bioinformatics analysis and dual luciferase reporter assay. GSEA was also employed for pathway enrichment analysis and the expression of Hippo-YAP pathway-related proteins was detected. The expression of HADHB was found to be low in STAD tissues and cells. The upregulation of HADHB distinctly repressed the viability, proliferation, colony formation, cell cycle progression, migration, invasion, and wound healing of HGC27 cells, while knockdown of HADHB led to opposite effects. HADHB upregulation impeded tumour growth and cell proliferation, and enhanced apoptosis in nude mice. KLF4, whose expression was low in STAD, was identified as an upstream regulator of HADHB. KLF4 upregulation abolished the HADHB knockdown-induced tumour promoting effects in AGS cells. Further, HADHB regulates the Hippo-YAP pathway, which was validated using a pathway rescue assay. Low expression of KLF4 led to HADHB downregulation in STAD. HADHB might function as a tumour suppressor gene in STAD by regulation the Hippo-YAP pathway.

Hadh deficiency induced oligoasthenoteratozoospermia through the TNF-α/Bcl-2 pathway in male mice.

The process of spermatogenesis is a complex and delicate process that is still not fully understood. In this study, we examined the role of fatty acid oxidase 3-hydroxy acyl CoA dehydrogenase (HADH) in maintaining normal spermatogenesis in mice. In male mice, ablation of the Hadh gene using CRISPR/Cas9 technology arrested spermatocyte meiosis, increased multinucleated giant germ cells and vacuoles in seminiferous tubules, and accompanied with acrosomal dysplasia. Hadh-/- male mice showed the typical features of oligoasthenoteratozoospermia (OAT), including decreased sperm concentration and motility and increased sperm abnormalities. Next, we explored the molecular events in the testes of the mutant mice. We found fatty acids accumulated in the testis of Hadh-/- mice. And also, inflammatory factors TNF-α, IL-1β, and IL-6 were significantly increased, apoptosis-related protein Bcl-2 was decreased, and Bax and cleaved-Caspase3 were increased in Hadh-/- male mice testis. After using etanercept, a specific inhibitor of TNF-α, testis injury caused by Hadh knockout was significantly alleviated, the sperm quality and motility were improved, and germ cell apoptosis was reduced. So our study demonstrated that Hadh deletion caused an increase in fatty acids. The accumulated fatty acids further induced testicular inflammation and germ cell apoptosis through the TNF-α/Bcl-2 signaling pathway, finally resulting in OAT in the Hadh-/- mice. Inhibiting TNF-α may be used as a new treatment approach for testicular inflammation and OAT.

The effects of training, acute exercise and dietary fatty acid composition on muscle lipid oxidative capacity in European starlings.

Migratory birds undergo seasonal changes to muscle biochemistry. Nonetheless, it is unclear to what extent these changes are attributable to the exercise of flight itself versus endogenous changes. Using starlings (Sturnus vulgaris) flying in a wind tunnel, we tested the effects of exercise training, a single bout of flight and dietary lipid composition on pectoralis muscle oxidative enzymes and lipid transporters. Starlings were either unexercised or trained over 2 weeks to fly in a wind tunnel and sampled either immediately following a long flight at the end of this training or after 2 days recovery from this flight. Additionally, they were divided into dietary groups that differed in dietary fatty acid composition (high polyunsaturates versus high monounsaturates) and amount of dietary antioxidant. Trained starlings had elevated (19%) carnitine palmitoyl transferase and elevated (11%) hydroxyacyl-CoA dehydrogenase in pectoralis muscle compared with unexercised controls, but training alone had little effect on lipid transporters. Immediately following a long wind-tunnel flight, starling pectoralis had upregulated lipid transporter mRNA (heart-type fatty acid binding protein, H-FABP, 4.7-fold; fatty acid translocase, 1.9-fold; plasma membrane fatty acid binding protein, 1.6-fold), and upregulated H-FABP protein (68%). Dietary fatty acid composition and the amount of dietary antioxidants had no effect on muscle catabolic enzymes or lipid transporter expression. Our results demonstrate that birds undergo rapid upregulation of catabolic capacity that largely becomes available during flight itself, with minor effects due to training. These effects likely combine with endogenous seasonal changes to create the migratory phenotype observed in the wild.

HADHA Inhibits the Migration and Invasion of HTR-8/SVneo Cells by Regulating PI3K/AKT Signaling Pathway

To explore the effects of hydroxyacyl-CoA dehydrogenase alpha subunit (HADHA) on the migration and invasion of HTR-8/SVneo cells, a human trophoblast cell line, and its potential mechanism of action. Immunofluorescence staining was done to evaluate the expression levels of HADHA in samples of normal villi and recurrent spontaneous abortion (RSA) villi at 6-8 weeks. Lentiviral infection system was used to construct stable HTR-8/SVneo cell lines with HADHA overexpression and knockdown. Western blot, qRT-PCR, Wound-healing assay, and Transwell assay were used to determine the effect of HADHA on the migration and invasion of HTR-8/SVneo cells and the expression of relevant genes. Transcriptome sequencing and bioinformatics analysis were done to screen for the potential target genes and signaling pathways regulated by HADHA. The specific molecular mechanism of how HADHA regulates the migration and invasion of HTR-8/SVneo cells was examined by adding the inhibitor of protein kinase B (PKB/AKT). HADHA was highly expressed in extravillous trophoblasts (EVT) of RSA villus samples as compared with samples from the normal control group. In HTR-8/SVneo cells overexpressing HADHA, the expression levels of migration and invasion-related genes, including HLA-G, MMP2, MMP9, and NCAD, were decreased (P<0.01,P<0.05), and the migration and invasion abilities of HTR-8/SVneo cells were weakened (P<0.05). HADHA knockdown increased the expression levels of HLA-G, MMP2, MMP9, and NCAD (P<0.01, P<0.05), and promoted the migration and invasion of HTR-8/SVneo cells (P<0.05). In addition, HADHA overexpression decreased the phosphorylation levels of PI3K and AKT (P<0.05) and inhibited the PI3K/AKT signaling pathway. HADHA knockdown activated the PI3K/AKT signaling pathway. When MK-2206, an AKT inhibitor, was added to stable HTR-8/SVneo cell lines with HADHA knockdown, the migration and invasion of the cells were significantly reduced. HADHA inhibits the migration and invasion of HTR-8/SVneo cells by inhibiting the PI3K/AKT signaling pathway.

Glyoxylase-1 combats dicarbonyl stress and right ventricular dysfunction in rodent pulmonary arterial hypertension.

BackgroundHeightened glycolytic flux is associated with right ventricular (RV) dysfunction in pulmonary arterial hypertension (PAH). Methylglyoxal, a glycolysis byproduct, is a highly reactive dicarbonyl that has toxic effects via non-enzymatic post-translational modifications (protein glycation). Methylglyoxal is degraded by the glyoxylase system, which includes the rate-limiting enzyme glyoxylase-1 (GLO1), to combat dicarbonyl stress. However, the potential consequences of excess protein glycation on RV function are unknown.MethodsBioinformatics analysis of previously identified glycated proteins predicted how protein glycation regulated cardiac biology. Methylglyoxal treatment of H9c2 cardiomyocytes evaluated the consequences of excess protein glycation on mitochondrial respiration. The effects of adeno-associated virus serotype 9-mediated (AAV9) GLO1 expression on RV function in monocrotaline rats were quantified with echocardiography and hemodynamic studies. Immunoblots and immunofluorescence were implemented to probe the effects of AAV-Glo1 on total protein glycation and fatty acid oxidation (FAO) and fatty acid binding protein levels.ResultsIn silico analyses highlighted multiple mitochondrial metabolic pathways may be affected by protein glycation. Exogenous methylglyoxal minimally altered mitochondrial respiration when cells metabolized glucose, however methylglyoxal depressed FAO. AAV9-Glo1 increased RV cardiomyocyte GLO1 expression, reduced total protein glycation, partially restored mitochondrial density, and decreased lipid accumulation. In addition, AAV9-Glo1 increased RV levels of FABP4, a fatty acid binding protein, and hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunits alpha and beta (HADHA and HADHB), the two subunits of the mitochondrial trifunctional protein for FAO. Finally, AAV9-Glo1 blunted RV fibrosis and improved RV systolic and diastolic function.ConclusionExcess protein glycation promotes RV dysfunction in preclinical PAH, potentially through suppression of FAO.