Deficiency of the metabolic enzyme SCHAD in pancreatic ß-cells promotes amino acid-sensitive hypoglycemia.

Congenital hyperinsulinism of infancy (CHI) can be caused by a deficiency of the ubiquitously expressed enzyme short-chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD). To test the hypothesis that SCHAD-CHI arises from a specific defect in pancreatic ß-cells, we created genetically engineered ß-cell-specific (ß-SKO) or hepatocyte-specific (L-SKO) SCHAD knockout mice. While L-SKO mice were normoglycemic, plasma glucose in ß-SKO animals was significantly reduced in the random-fed state, after overnight fasting, and following refeeding. The hypoglycemic phenotype was exacerbated when the mice were fed a diet enriched in leucine, glutamine, and alanine. Intraperitoneal injection of these three amino acids led to a rapid elevation in insulin levels in ß-SKO mice compared to controls. Consistently, treating isolated ß-SKO islets with the amino acid mixture potently enhanced insulin secretion compared to controls in a low-glucose environment. RNA sequencing of ß-SKO islets revealed reduced transcription of ß-cell identity genes and upregulation of genes involved in oxidative phosphorylation, protein metabolism, and Ca2+ handling. The ß-SKO mouse offers a useful model to interrogate the intra-islet heterogeneity of amino acid sensing given the very variable expression levels of SCHAD within different hormonal cells, with high levels in ß- and δ-cells and virtually absent α-cell expression. We conclude that the lack of SCHAD protein in ß-cells results in a hypoglycemic phenotype characterized by increased sensitivity to amino acid-stimulated insulin secretion and loss of ß-cell identity.

A (S)-3-Hydroxybutyrate Dehydrogenase Belonging to the 3-Hydroxyacyl-CoA Dehydrogenase Family Facilitates Hydroxyacid Degradation in Anaerobic Bacteria.

Ketone bodies, including acetoacetate, 3-hydroxybutyrate, and acetone, are produced in the liver of animals during glucose starvation. Enzymes for the metabolism of (R)-3-hydroxybutyrate have been extensively studied, but little is known about the metabolism of its enantiomer (S)-3-hydroxybutyrate. Here, we report the characterization of a novel pathway for the degradation of (S)-3-hydroxybutyrate in anaerobic bacteria. We identify and characterize a stereospecific (S)-3-hydroxylbutyrate dehydrogenase (3SHBDH) from Desulfotomaculum ruminis, which catalyzes the reversible NAD(P)H-dependent reduction of acetoacetate to form (S)-3-hydroxybutyrate. 3SHBDH also catalyzes oxidation of d-threonine (2R, 3S) and l-allo-threonine (2S, 3S), consistent with its specificity for ß-(3S)-hydroxy acids. Isothermal calorimetry experiments support a sequential mechanism involving binding of NADH prior to (S)-3-hydroxybutyrate. Homologs of 3SHBDH are present in anaerobic fermenting and sulfite-reducing bacteria, and experiments with Clostridium pasteurianum showed that 3SHBDH, acetate CoA-transferase (YdiF), and (S)-3-hydroxybutyryl-CoA dehydrogenase (Hbd) are involved together in the degradation of (S)-3-hydroxybutyrate as a carbon and energy source for growth. (S)-3-hydroxybutyrate is a human metabolic marker and a chiral precursor for chemical synthesis, suggesting potential applications of 3SHBDH in diagnostics or the chemicals industry. IMPORTANCE (R)-3-hydroxybutyrate is well studied as a component of ketone bodies produced by the liver and of bacterial polyesters. However, the biochemistry of its enantiomer (S)-3-hydroxybutyrate is poorly understood. This study describes the identification and characterization of a stereospecific (S)-3-hydroxylbutyrate dehydrogenase and its function in a metabolic pathway for the degradation of (S)-3-hydroxybutyrate as a carbon and energy source in anaerobic bacteria. (S)-3-hydroxybutyrate is a mammalian metabolic marker and a precursor for chemical synthesis and bioplastics, suggesting potential applications of these enzymes in diagnostics and biotechnology.

Robust arm and leg muscle adaptation to training despite ACE inhibition: a randomized placebo-controlled trial.

PURPOSE: Angiotensin-converting enzyme (ACE) inhibitor treatment is widely applied, but the fact that plasma ACE activity is a potential determinant of training-induced local muscular adaptability is often neglected. Thus, we investigated the hypothesis that ACE inhibition modulates the response to systematic aerobic exercise training on leg and arm muscular adaptations. METHODS: Healthy, untrained, middle-aged participants (40 ± 7 yrs) completed a randomized, double-blinded, placebo-controlled trial. Participants were randomized to placebo (PLA: CaCO3) or ACE inhibitor (ACEi: enalapril) for 8 weeks and completed a supervised, high-intensity exercise training program. Muscular characteristics in the leg and arm were extensively evaluated pre and post-intervention. RESULTS: Forty-eight participants (nACEi = 23, nPLA = 25) completed the trial. Exercise training compliance was above 99%. After training, citrate synthase, 3-hydroxyacyl-CoA dehydrogenase and phosphofructokinase maximal activity were increased in m. vastus lateralis in both groups (all P < 0.05) without statistical differences between them (all time × treatment P > 0.05). In m. deltoideus, citrate synthase maximal activity was upregulated to a greater extent (time × treatment P < 0.05) in PLA (51 [33;69] %) than in ACEi (28 [13;43] %), but the change in 3-hydroxyacyl-CoA dehydrogenase and phosphofructokinase maximal activity was similar between groups. Finally, the training-induced changes in the platelet endothelial cell adhesion molecule-1 protein abundance, a marker of capillary density, were similar in both groups in m. vastus lateralis and m. deltoideus. CONCLUSION: Eight weeks of high-intensity whole-body exercise training improves markers of skeletal muscle mitochondrial oxidative capacity, glycolytic capacity and angiogenesis, with no overall effect of pharmacological ACE inhibition in healthy adults.

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-1ß, 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.

Functional analysis of HADH c.99C>G shows that the variant causes the proliferation of pancreatic islets and leu-sensitive hyperinsulinaemia.

A novel missense variant (NM_005327.7: c.99C>G, p.Ile33Met) was discovered in 3-hydroxyacyl-CoA dehydrogenase (HADH), which is involved in congenital hyperinsulinism (CHI). This variant may be damaging or deleterious, as assessed using protein prediction software. This study aimed at the impact of this variant on islets and if it caused the leu-sensitive insulin secretion. The adenoassociated virus containing the HADH missense variant (p.Ile33Met), wild-type (WT) HADH or empty vector (EV) was constructed, and the rats were infected with it. Three weeks after the transfection, 15 rats were dissected to observe the effect of the variant on the islet tissue. Then we treated the remaining rats with leucine or sodium carboxymethyl cellulose (CMC-Na) by gavage and drew blood from the rat tail vein to detect the variations in blood glucose, serum insulin and serum glucagon. Further, we dissected the rats to observe the fluctuation of insulin and glucagon contents in pancreatic islets under the combined action of leucine and p.Ile33Met. Insulin and glucagon were observed in the islet tissue under an inverted fluorescence microscope, serum insulin and glucagon were detected by ELISA, and the blood glucose value was determined using a Roche glucometer. The positive area and average gray value of islet fluorescence pictures were analysed using the software Image J (USA). Rats expressing p.Ile33Met showed significantly higher insulin and glucagon content, as well as the islet area, compared to WT and EV rats. Moreover, after intragastric administration of leucine, the serum insulin content of the variant rats increased but the blood sugar level decreased significantly. Meanwhile, there was an appreciable decrease in the insulin content in rat pancreatic islet tissues. Our results suggest that the variant NM_005327.7: c.99C>G promotes the proliferation of pancreatic islets, enhances the secretion of insulin, and induces leu-sensitive hyperinsulinaemia.

Salinomycin biosynthesis reversely regulates the ß-oxidation pathway in Streptomyces albus by carrying a 3-hydroxyacyl-CoA dehydrogenase gene in its biosynthetic gene cluster.

Streptomyces is well known for synthesis of many biologically active secondary metabolites, such as polyketides and non-ribosomal peptides. Understanding the coupling mechanisms of primary and secondary metabolism can help develop strategies to improve secondary metabolite production in Streptomyces. In this work, Streptomyces albus ZD11, an oil-preferring industrial Streptomyces strain, was proved to have a remarkable capability to generate abundant acyl-CoA precursors for salinomycin biosynthesis with the aid of its enhanced ß-oxidation pathway. It was found that the salinomycin biosynthetic gene cluster contains a predicted 3-hydroxyacyl-CoA dehydrogenase (FadB3), which is the third enzyme of ß-oxidation cycle. Deletion of fadB3 significantly reduced the production of salinomycin. A variety of experimental evidences showed that FadB3 was mainly involved in the ß-oxidation pathway rather than ethylmalonyl-CoA biosynthesis and played a very important role in regulating the rate of ß-oxidation in S. albus ZD11. Our findings elucidate an interesting coupling mechanism by which a PKS biosynthetic gene cluster could regulate the ß-oxidation pathway by carrying ß-oxidation genes, enabling Streptomyces to efficiently synthesize target polyketides and economically utilize environmental nutrients.

Crystal structure of multi-functional enzyme FadB from Cupriavidus necator: Non-formation of FadAB complex.

Cupriavidus necator H16 is a gram-negative chemolithoautotrophic bacterium that has been extensively studied for biosynthesis and biodegradation of polyhydroxyalkanoate (PHA) plastics. To improve our understanding of fatty acid metabolism for PHA production, we determined the crystal structure of multi-functional enoyl-CoA hydratase from Cupriavidus necator H16 (CnFadB). The predicted model of CnFadB created by AlphaFold was used to solve the phase problem during determination of the crystal structure of the protein. The CnFadB structure consists of two distinctive domains, an N-terminal enol-CoA hydratase (ECH) domain and a C-terminal 3-hydroxyacyl-CoA dehydrogenase (HAD) domain, and the substrate- and cofactor-binding modes of these two functional domains were identified. Unlike other known FadB enzymes that exist as dimers complexed with FadA, CnFadB functions as a monomer without forming a complex with CnFadA. Small angle X-ray scattering (SAXS) measurement further proved that CnFadB exists as a monomer in solution. The non-sequential action of FadA and FadB in C. necator appears to affect ß-oxidation and PHA synthesis/degradation.

Molecular characterization and immune protection of the 3-hydroxyacyl-CoA dehydrogenase gene in Echinococcus granulosus.

BACKGROUND: Cystic echinococcosis (CE) is a serious parasitic zoonosis caused by the larvae of the tapeworm Echinococcus granulosus. The development of an effective vaccine is one of the most promising strategies for controlling CE. METHODS: The E. granulosus 3-hydroxyacyl-CoA dehydrogenase (EgHCDH) gene was cloned and expressed in Escherichia coli. The distribution of EgHCDH in protoscoleces (PSCs) and adult worms was analyzed using immunofluorescence. The transcript levels of EgHCDH in PSCs and adult worms were analyzed using quantitative real-time reverse transcription PCR (RT-qPCR). The immune protective effects of the rEgHCDH were evaluated. RESULTS: The 924-bp open reading frame sequence of EgHCDH, which encodes a protein of approximately 34 kDa, was obtained. RT-qPCR analysis revealed that EgHCDH was expressed in both the PSCs and adult worms of E. granulosus. Immunofluorescence analysis showed that EgHCDH was mainly localized in the tegument of PSCs and adult worms. Western blot analysis showed that the recombinant protein was recognized by E. granulosus-infected dog sera. Animal challenge experiments demonstrated that dogs immunized with recombinant (r)EgHCDH had significantly higher serum IgG, interferon gamma and interleukin-4 concentrations than the phosphate-buffered saline (PBS) control group. The rEgHCDH vaccine was able to significantly reduce the number of E. granulosus and inhibit the segmental development of E. granulosus compared to the PBS control group. CONCLUSIONS: The results suggest that rEgHCDH can induce partial immune protection against infection with E. granulosus and could be an effective candidate for the development of new vaccines.

Differentially expressed genes PCCA, ECHS1, and HADH are potential prognostic biomarkers for gastric cancer.

Gastric cancer (GC) is one of the most common malignant tumors in the world. As far as we know, no biomarker has been widely accepted for early diagnosis and prognosis prediction of GC. The purpose of this study is to find potential biomarkers to predict the prognosis of GC. The differentially expressed gene (DEG) was analyzed from GSE93774. Enrichr was used to analyze the gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, the enrichment of transcription factors (TF), miRNA, and kinase. GO analysis showed DEGs was enriched in the process of amino acid metabolism. Pathway results showed DEGs was mainly enriched in cell cycle. Propionyl CoA carboxylase alpha (PCCA), Enoyl coenzyme A hydratase short chain 1 (ECHS1), and 3-hydroxyacyl-CoA dehydrogenase (HADH) have prognostic value in patients with GC. ECHS1 and HADH genes were significantly associated with disease-free survival. There was a significant correlation between PCCA and overall survival rate. The results of this study suggest that PCCA, ECHS1, and HADH may be new biomarkers for predicting the prognosis of GC.

iTRAQ-facilitated proteomic analysis of Bacillus cereus via degradation of malachite green.

The wide use of malachite green (MG) as a dye has caused substantial concern owing to its toxicity. Bacillus cereus can against the toxic effect of MG and efficiently decolourise it. However, detailed information regarding its underlying adaptation and degradation mechanisms based on proteomic data is scarce. In this study, the isobaric tags for relative and absolute quantitation (iTRAQ)-facilitated quantitative method was applied to analyse the molecular mechanisms by which B. cereus degrades MG. Based on this analysis, 209 upregulated proteins and 198 downregulated proteins were identified with a false discovery rate of 1% or less during MG biodegradation. Gene ontology and KEGG analysis determined that the differentially expressed proteins were enriched in metabolic processes, catalytic activity, antioxidant activity, and responses to stimuli. Furthermore, real-time qPCR was utilised to further confirm the regulated proteins involved in benzoate degradation. The proteins BCE_4076 (Acetyl-CoA acetyltransferase), BCE_5143 (Acetyl-CoA acetyltransferase), BCE_5144 (3-hydroxyacyl-CoA dehydrogenase), BCE_4651 (Enoyl-CoA hydratase), and BCE_5474 (3-hydroxyacyl-CoA dehydrogenase) involved in the benzoate degradation pathway may play an important role in the biodegradation of MG by B. cereus. The results of this study not only provide a comprehensive view of proteomic changes in B. cereus upon MG loading but also shed light on the mechanism underlying MG biodegradation by B. cereus.

Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency and progressive retinopathy: one case report followed by ERGs, VEPs, EOG over a 17-year period.

BACKGROUND: LCHAD (long-chain 3-hydroxyacyl-CoA dehydrogenase) deficiency is a rare genetic disorder of mitochondrial long-chain fatty acid oxidation inherited as a recessive trait. Affected patients can present with hypoglycaemia, rhabdomyolysis and cardiomyopathy. About half of the patients may suffer from retinopathy. CASE REPORT: A 19-year-old girl was diagnosed as suffering from LCHAD deficiency with recurrent rhabdomyolysis episodes at the age of 7 months by an inaugural coma with hypoglycaemia and hepatomegaly. Appropriate dietary management with carnitine supplementation was initiated. Retinopathy was diagnosed at age two. Ophthalmological assessments including visual acuity, visual field, OCT, flash ERGs, P-ERG, flash VEPs and EOG recordings were conducted over a 17-year period. RESULTS: Visual acuity was decreased. Fundi showed a progressive retinopathy and chorioretinopathy. Photophobia was noticed 2 years before the decrease in photopic-ERG amplitude with normal scotopic-ERGs. Scotopic-ERG amplitude decreased 10 years after the decrease in photopic-ERG amplitude. No EOG light rise was observed. Flash VEPs remained normal. These results suggest that the cone system dysfunction occurs largely prior to the rod system dysfunction with a relative preservation of the macula function. COMMENTS: This dysfunction of cones prior to the dysfunction of rods was not reported previously. This could be related to mitochondrial energy failure in cones as cones are greater consumers of ATP than rods. This hypothesis needs to be further confirmed as other long-chain fatty oxidation defective patients (VLCAD and CPT2 deficiencies) do not exhibit retinopathy.

Distribution of concurrent training sessions does not impact endurance adaptation.

OBJECTIVES: Optimized concurrent training regimes are warranted in physical training of military-, law enforcement- and rescue-personnel. This study investigated if four 15-min endurance training sessions weekly improve aerobic capacity and performance more than one 60-min endurance session weekly during the initial phase of a Basic Military Training program. DESIGN: A randomized training intervention study with functional and physiological tests before and after the intervention. METHODS: Military conscripts (n=290) were randomly allocated to three groups completing 9 weeks training. Weekly training consisted of four endurance and four strength training sessions lasting 15min each ('Micro-training': MIC); one strength and one endurance session lasting 60min each ('Classical-training': CLA) or two 60min sessions of standard military training ('Control-training': CON). RESULTS: Both 12-min (∼7-10%) and shuttle run performance (∼35-42%) improved (P≤0.001) similarly in all groups. Likewise, functional 2-min maximal repetition exercise capacity increased (P≤0.05) similarly in all groups (Lunges ∼17-24 %; PushUp ∼10-20%; AbdominalFlexions∼21-23%). Peak oxygen uptake changes depended on group (P≤0.05) with increases (P≤0.01) in MIC (7±7%, n=23) and CON (12±18%, n=17) and no changes in CLA. Maximal m. vastus lateralis citrate synthase activity decreased 14±26% (P≤0.001, n=18) in CLA. Likewise, maximal m. vastus lateralis 3-hydroxyacyl-CoA dehydrogenase activity decreased 8±17% in MIC (n=28) and 14±24% in CLA (n=18). CONCLUSIONS: Four 15-min endurance training sessions weekly improves running performance and strength-endurance similarly to one 60min session. Peak oxygen uptake only increases with more than one endurance session weekly and leg muscle oxidative capacity appears reduced after basic military training.

Effects of lactate administration on mitochondrial enzyme activity and monocarboxylate transporters in mouse skeletal muscle.

Growing evidence shows that lactate is not merely an intermediate metabolite, but also a potential signaling molecule. However, whether daily lactate administration induces physiological adaptations in skeletal muscle remains to be elucidated. In this study, we first investigated the effects of daily lactate administration (equivalent to 1 g/kg of body weight) for 3 weeks on mitochondrial adaptations in skeletal muscle. We demonstrated that 3-week lactate administration increased mitochondrial enzyme activity (citrate synthase, 3-hydroxyacyl CoA dehydrogenase, and cytochrome c oxidase) in the plantaris muscle, but not in the soleus muscle. MCT1 and MCT4 protein contents were not different after 3-week lactate administration. Next, we examined whether lactate administration enhances training-induced adaptations in skeletal muscle. Lactate administration prior to endurance exercise training (treadmill running, 20 m/min, 60 min/day), which increased blood lactate concentration during exercise, enhanced training-induced mitochondrial enzyme activity in the skeletal muscle after 3 weeks. MCT protein content and blood lactate removal were not different after 3-week lactate administration with exercise training compared to exercise training alone. In a single bout experiment, lactate administration did not change the phosphorylation state of AMPK, ACC, p38 MAPK, and CaMKII in skeletal muscle. Our results suggest that lactate can be a key factor for exercise-induced mitochondrial adaptations, and that the efficacy of high-intensity training is, at least partly, attributed to elevated blood lactate concentration.

Effects of exercise training with short-duration intermittent hypoxia on endurance performance and muscle metabolism in well-trained mice.

The author previously reported that short-duration intermittent hypoxia had additive effects on improvements in endurance capacity by enhancing fatty acid metabolism. The present study was designed to investigate the effects of short-duration intermittent hypoxia on endurance capacity, metabolic enzyme activity, and protein levels associated with mitochondrial biogenesis in well-trained mice. Mice in the training group were housed in a cage with a running wheel for 7 weeks from 5 weeks old. Voluntary running markedly increased maximal work values by 5.0-fold. Trained mice were then subjected to either endurance treadmill training (ET) for 60 min or hybrid training (HT, ET for 30 min followed by sprint interval exercise (5-sec run-10-sec rest) for 30 min) with (H-ET or H-HT) or without (ET or HT) short-duration intermittent hypoxia (4 cycles of 12-13% O2 for 15 min and 20.9% O2 for 10 min) for 4 weeks. Maximal endurance capacity was markedly greater in the H-ET and H-HT than ET and HT groups, respectively. H-ET and H-HT increased activity levels of 3-hydroxyacyl-CoA-dehydrogenase in oxidative muscle portion and pyruvate dehydrogenase complex in glycolytic muscle portion. These activity levels were significantly correlated with maximal endurance capacity. Protein levels of dynamin-related protein-1 were increased more by H-ET and H-HT than by ET and HT, but were not significantly correlated with maximal work. These results suggest that intermittent hypoxic exposure has beneficial effects on endurance and hybrid training to improve the endurance capacity via improving fatty acid and pyruvate oxidation in highly trained mice.

1064 nm Nd:YAG laser light affects transmembrane mitochondria respiratory chain complexes.

Photobiomodulation (PBM) is a non-plant-cell manipulation through a transfer of energy by means of light sources at the non-ablative or thermal intensity. Authors showed that cytochrome-c-oxidase (complex IV) is the specific chromophore's target of PBM at the red (600-700 nm) and NIR (760-900 nm) wavelength regions. Recently, it was suggested that the infrared region of the spectrum could influence other chromospheres, despite the interaction by wavelengths higher than 900 nm with mitochondrial chromophores was not clearly demonstrated. We characterized the interaction between mitochondria respiratory chain, malate dehydrogenase, a key enzyme of Krebs cycle, and 3-hydroxyacyl-CoA dehydrogenase, an enzyme involved in the ß-oxidation (two mitochondrial matrix enzymes) with the 1064 nm Nd:YAG (100mps and 10 Hz frequency mode) irradiated at the average power density of 0.50, 0.75, 1.00, 1.25 and 1.50 W/cm2 to generate the respective fluences of 30, 45, 60, 75 and 90 J/cm2 . Our results show the effect of laser light on the transmembrane mitochondrial complexes I, III, IV and V (adenosine triphosphate synthase) (window effects), but not on the extrinsic mitochondrial membrane complex II and mitochondria matrix enzymes. The effect is not due to macroscopical thermal change. An interaction of this wavelength with the Fe-S proteins and Cu-centers of respiratory complexes and with the water molecules could be supposed.

[Regulation of pravastatin on long-chain fatty acid oxidative enzyme in pre-eclampsia-like mouse model].

Objective: To investigate the modulation of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) expression by pravastatin in pre-eclampsia-like mouse model. Methods: C57BL/6J mice were randomly injected with N-nitro-L-arginine methyl ester (L-NAME) as pre-eclampsia-like model group (PE) or saline as normal pregnancy control group (Con) respectively, from gestational the 7th to 18th day. For each group, pravastatin (PE+Pra, Con+Pra group) or saline (PE+N, Con+N Group) was given from the 8th to 18th day of gestation, respectively. Liver and placenta of pregnant mice were collected on gestational day 18. The LCHAD protein expression and mRNA levels of liver and placenta were detected through western blot, immunohistochemistry and real-time quantitative PCR. Results: (1) The average arterial pressure of pregnant mice increased gradually from the 8th to 18th day in PE+N group, but decreased in PE+Pra group from gestational 10th day, 24 hour urinary protein levels in PE+N group [(1 494 ± 201) µg] were significantly higher than that in Con+N group [(935±128) µg, P<0.01], and also higher than that in PE+Pra group [(981±116) µg, P<0.01].(2) The results of western blot: the expression of LCHAD was significantly lower in PE+N group (liver: 0.64±0.11, placenta: 0.48±0.06) than that in Con+N group (liver: 1.06±0.10, placenta: 0.60±0.10), and lower than that in PE+Pra group (liver: 0.99±0.04, placenta: 0.60±0.08; all P<0.01).(3)The results of real-time quantitative PCR: the levels of LCHAD mRNA in liver and placenta in PE+N group (liver: 0.621±0.128, placenta: 0.646±0.129) were significantly decreased compared with Con+N group (liver: 1.007±0.130, placenta: 1.004±0.103; all P<0.01), but there was no significant difference between PE+Pra group (liver: 0.693±0.678, placenta: 0.662±0.183; P>0.05). (4) LCHAD protein was expressed widely and evenly in liver. The expression in placental cytotrophoblast and syncytial trophoblast cells located in outer layer of villous in labyrinth layer was the most. The expression of LCHAD was significantly lower in PE+N group (liver: 0.062±0.016, placenta: 0.147±0.018) than that in Con+N group (liver: 0.126±0.013, placenta: 0.183±0.024), and lower than that in PE+Pra group (liver: 0.111±0.017, placenta: 0.174±0.027; all P<0.05). Conclusion: Pravastatin could upregulate the LCHAD protein expression of liver and placenta in the pre-eclampsia-like mouse, which may be a mechanism to improve the clinical manifestations of pre-eclampsia.

The p75NTR-mediated effect of nerve growth factor in L6C5 myogenic cells.

OBJECTIVE: During muscle development or regeneration, myocytes produce nerve growth factor (NGF) as well as its tyrosine-kinase and p75-neurotrophin (p75NTR) receptors. It has been published that the p75NTR receptor could represent a key regulator of NGF-mediated myoprotective effect on satellite cells, but the precise function of NGF/p75 signaling pathway on myogenic cell proliferation, survival and differentiation remains fragmented and controversial. Here, we verified the role of NGF in the growth, survival and differentiation of p75NTR-expressing L6C5 myogenic cells, specifically inquiring for the putative involvement of the nuclear factor κB (NFκB) and the small heat shock proteins (sHSPs) αB-crystallin and Hsp27 in these processes. RESULTS: Although NGF was not effective in modulating myogenic cell growth or survival in both standard or stress conditions, we demonstrated for the first time that, under serum deprivation, NGF sustained the activity of some key enzymes involved in energy metabolism. Moreover, we confirmed that NGF promotes myogenic fusion and expression of the structural protein myosin heavy chain while modulating NFκB activation and the content of sHSPs correlated with the differentiation process. We conclude that p75NTR is sufficient to mediate the modulation of L6C5 myogenic differentiation by NGF in term of structural, metabolic and functional changes.

Exercise with weight loss improves adipose tissue and skeletal muscle markers of fatty acid metabolism in postmenopausal women.

OBJECTIVE: The effects of 6-month weight loss (WL) versus aerobic exercise training (AEX)+WL on fat and skeletal muscle markers of fatty acid metabolism were determined in normal (NGT) and impaired (IGT) glucose tolerant African-American and Caucasian postmenopausal women with overweight/obesity. METHODS: Fat (gluteal and abdominal) lipoprotein lipase (LPL), skeletal muscle LPL, acyl-CoA synthase (ACS), ß-hydroxacyl-CoA dehydrogenase, carnitine palmitoyltransferase (CPT-1), and citrate synthase (CS) activities were measured at baseline (n = 104) and before and after WL (n = 34) and AEX+WL (n = 37). RESULTS: After controlling for age and race, muscle LPL and CPT-1 were lower in IGT, and the ratios of fat/muscle LPL activity were higher in IGT compared to NGT. Muscle LPL was related to insulin sensitivity (M value) and inversely related to G120 , fasting insulin, and homeostatic model assessment of insulin resistance. AEX+WL decreased abdominal fat LPL and increased muscle LPL, ACS, and CS. The ratios of fat/muscle LPL decreased after AEX+WL. The change in VO2 max was related to the changes in LPL, ACS, and CS and inversely related to the changes in fat/muscle LPL activity ratios. CONCLUSIONS: Six-month AEX+WL, and not WL alone, is capable of enhancing skeletal muscle fatty acid metabolism in postmenopausal African-American and Caucasian women with NGT, IGT, and overweight/obesity.

Acute Fatty Liver Disease of Pregnancy: Updates in Pathogenesis, Diagnosis, and Management.

Acute fatty liver of pregnancy (AFLP) is an obstetric emergency characterized by maternal liver failure and may have complications for the mother and fetus, including death. This review examines recent literature on the epidemiology, pathogenesis, diagnosis, and treatment of acute fatty liver of pregnancy. Pathogenesis of this disease has been linked to defects in fatty acid metabolism during pregnancy, especially in the setting of fetal genetic defects in fatty acid oxidation. The value of screening all patients for these genetic defects remains to be determined. Distinguishing AFLP from other high-risk liver diseases of pregnancy that have overlap features, such as HELLP and preeclampsia, can be challenging. Although sensitive diagnostic tools such as the Swansea criteria have been developed, further work is needed to diagnose AFLP more quickly. Although survival rates have improved in the past 30 years, delay in diagnosis and treatment of AFLP has life-threatening consequences; an algorithmic approach to AFLP may be a valuable resource for clinicians. Future epidemiological and long-term studies will improve our prediction of women at risk for developing AFLP and determine the long-term consequences of this condition.

The Hypoglycemic Phenotype Is Islet Cell-Autonomous in Short-Chain Hydroxyacyl-CoA Dehydrogenase-Deficient Mice.

Congenital hyperinsulinism of infancy (CHI) can be caused by inactivating mutations in the gene encoding short-chain 3-hydroxyacyl-CoA dehydrogenase (SCHAD), a ubiquitously expressed enzyme involved in fatty acid oxidation. The hypersecretion of insulin may be explained by a loss of interaction between SCHAD and glutamate dehydrogenase in the pancreatic ß-cells. However, there is also a general accumulation of metabolites specific for the enzymatic defect in affected individuals. It remains to be explored whether hypoglycemia in SCHAD CHI can be uncoupled from the systemic effect on fatty acid oxidation. We therefore transplanted islets from global SCHAD knockout (SCHADKO) mice into mice with streptozotocin-induced diabetes. After transplantation, SCHADKO islet recipients exhibited significantly lower random and fasting blood glucose compared with mice transplanted with normal islets or nondiabetic, nontransplanted controls. Furthermore, intraperitoneal glucose tolerance was improved in animals receiving SCHADKO islets compared with those receiving normal islets. Graft ß-cell proliferation and apoptosis rates were similar in the two transplantation groups. We conclude that hypoglycemia in SCHAD-CHI is islet cell-autonomous.