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Simple Summary: The recently identified lysine methyltransferase (KMT) 9 regulates the growth of different types of cancer. While KMT9 was shown to be overexpressed in muscle-invasive bladder cancer (MIBC) tissue samples of patients, a potential functional role of the enzyme in MIBC remains to be clarified. In this study, we show that KMT9 regulates the proliferation, migration, and invasion of various MIBC cell lines as well as the growth of BC tumor organoids and xenografts in mice. Our data provide evidence that tumor cell growth relies on the enzymatic function of KMT9 and that a small-molecule inhibitor of KMT9 impairs BC cell proliferation. These results suggest that KMT9 is a potential novel therapeutic target for MIBC treatment. Novel treatment modalities are imperative for the challenging management of muscle-invasive and metastatic BC to improve patient survival rates. The recently identified KMT9, an obligate heterodimer composed of KMT9α and KMT9β, regulates the growth of various types of tumors such as prostate, lung, and colon cancer. While the overexpression of KMT9α was previously observed to be associated with aggressive basal-like MIBC in an analysis of patients' tissue samples, a potential functional role of KMT9 in this type of cancer has not been investigated to date. In this study, we show that KMT9 regulates proliferation, migration, and invasion of various MIBC cell lines with different genetic mutations. KMT9α depletion results in the differential expression of genes regulating the cell cycle, cell adhesion, and migration. Differentially expressed genes include oncogenes such as EGFR and AKT1 as well as mediators of cell adhesion or migration such as DAG1 and ITGA6. Reduced cell proliferation upon KMT9α depletion is also observed in Pten/Trp53 knockout bladder tumor organoids, which cannot be rescued with an enzymatically inactive KMT9α mutant. In accordance with the idea that the catalytic activity of KMT9 is required for the control of cellular processes in MIBC, a recently developed small-molecule inhibitor of KMT9 (KMI169) also impairs cancer cell proliferation. Since KMT9α depletion also restricts the growth of xenografts in mice, our data suggest that KMT9 is an actionable novel therapeutic target for the treatment of MIBC. [ABSTRACT FROM AUTHOR]

Objective: Preoperative chronic stress (CS) is associated with postoperative brain injury in patients undergoing open heart cardiac surgery. This research is to explore the potential molecular biological mechanisms of brain damage following cardiac surgery in preoperative CS rats by the analyses combining proteomics and metabolomics. Methods: We constructed the chronic unpredictable stress (CUS) and cardiac surgery models in adult rats. We proved the brain injury in CUS cardiac surgery rats by Hematoxylin–Eosin (H&E) staining, followed by separating the hippocampal tissue and investigating the potential mechanisms of brain injury by the methods of data-independent acquisition proteomics and untargeted metabolomics. Results: The signaling pathways of glycoproteins and metabolism of amino acids were the main possible mechanisms of brain injury in CUS rats following cardiac surgery according to the proteomics and metabolomics. In addition, the pathways of animo acids metabolism such as the pathways of lysine degradation and β-alanine metabolism may be the main mechanism of cardiac surgery related brain injury in preoperative CUS rats. Conclusions: The pathways of animo acids metabolism such as lysine degradation and β-alanine metabolism may be the potential mechanisms of brain injury in CUS rats following cardiac surgery. We should focus on the varieties of bioproteins and metabolites in these pathways, and related changes in other signaling pathways induced by the two pathways. [ABSTRACT FROM AUTHOR]

Objective: Many patients with acromegaly, a hormonal disorder with excessive growth hormone (GH) production, report pain in joints. We undertook this study to characterize the joint pathology of mice with overexpression of bovine GH (bGH) or a GH receptor antagonist (GHa) and to investigate the effect of GH on regulation of chondrocyte cellular metabolism. Methods: Knee joints from mice overexpressing bGH or GHa and wild‐type (WT) control mice were examined using histology and micro–computed tomography for osteoarthritic (OA) pathologies. Additionally, cartilage from bGH mice was used for metabolomics analysis. Mouse primary chondrocytes from bGH and WT mice, with or without pegvisomant treatment, were used for quantitative polymerase chain reaction and Seahorse respirometry analyses. Results: Both male and female bGH mice at ~13 months of age had increased knee joint degeneration, which was characterized by loss of cartilage structure, expansion of hypertrophic chondrocytes, synovitis, and subchondral plate thinning. The joint pathologies were also demonstrated by significantly higher Osteoarthritis Research Society International and Mankin scores in bGH mice compared to WT control mice. Metabolomics analysis revealed changes in a wide range of metabolic pathways in bGH mice, including beta‐alanine metabolism, tryptophan metabolism, lysine degradation, and ascorbate and aldarate metabolism. Also, bGH chondrocytes up‐regulated fatty acid oxidation and increased expression of Col10a. Joints of GHa mice were remarkably protected from developing age‐associated joint degeneration, with smooth articular joint surface. Conclusion: This study showed that an excessive amount of GH promotes joint degeneration in mice, which was associated with chondrocyte metabolic dysfunction and hypertrophic changes, whereas antagonizing GH action through a GHa protects mice from OA development. [ABSTRACT FROM AUTHOR]

Background: DNA damage repair is a crucial mechanism highly related to therapy resistance for various therapeutic strategies. Our previous results have shown that the degree of drug resistance in small‐cell lung cancer (SCLC) cell lines was proportional to both the transcription and expression levels of Wee1, indicating that Wee1, an evolutionarily highly conserved kinase, plays a vital role in the therapeutic resistance of SCLC. In the present study, we aim to determine the nonclassical mechanism of Wee1 on DNA repair regulation. Methods: Western blot was conducted to determine the mono‐ubiquitination level of H2Bub. Comet assay was used to evaluate the degree of DNA damage. Immunofluorescence was conducted to determine the DNA repair markers. Co‐immunoprecipitation was utilized to assess the potential interactions with H2BY37ph. MTT assays were used to evaluate the survival rates of SCLC cells. Results: Overexpression of Wee1 increases the level of H2BK120ub and alleviates ionizing radiation (IR)‐induced DNA damage in SCLC cells. Moreover, H2BK120ub is a crucial molecule in Wee1‐mediated double‐strain break (DSB) repair in SCLC cells. Mechanisms study indicated that H2BY37ph is involved in Wee1‐mediated H2BK120ub through interaction with the E3 ubiquitin ligase RNF20–RNF40 complex and upregulates its phosphorylation, mutation of H2BY37 phosphorylation sites attenuated DSB repair and enhanced the sensitivity of IR‐induced SCLC cell death. Conclusion: H2BY37ph produces crosstalk with H2BK120ub in an E3 ubiquitin ligase‐dependent manner, promoting Wee1‐mediated DSB repair in SCLC cells. This study clarifies the nonclassical mechanism of Wee1 regulation of DSB repair, which provides a theoretical basis for the clinical understanding of the regulatory network of Wee1 and its use as a target for overcoming multiple types of therapeutic resistance. [ABSTRACT FROM AUTHOR]

Post-translational modifications on histones are well known to regulate chromatin structure and function, but much less information is available on modifications of the centromeric histone H3 variant and their effect at the kinetochore. Here, we report two modifications on the centromeric histone H3 variant CENP-A/Cse4 in the yeast Saccharomyces cerevisiae, methylation at arginine 143 (R143me) and lysine 131 (K131me), that affect centromere stability and kinetochore function. Both R143me and K131me lie in the core region of the centromeric nucleosome, near the entry/exit sites of the DNA from the nucleosome. Unexpectedly, mutation of Cse4-R143 (cse4-R143A) exacerbated the kinetochore defect of mutations in components of the NDC80 complex of the outer kinetochore (spc25-1) and the MIND complex (dsn1-7). The analysis of suppressor mutations of the spc25-1 cse4-R143A growth defect highlighted residues in Spc24, Ndc80, and Spc25 that localize to the tetramerization domain of the NDC80 complex and the Spc24-Spc25 stalk, suggesting that the mutations enhance interactions among NDC80 complex components and thus stabilize the complex. Furthermore, the Set2 histone methyltransferase inhibited kinetochore function in spc25-1 cse4-R143A cells, possibly by methylating Cse4-K131. Taken together, our data suggest that Cse4-R143 methylation and Cse4-K131 methylation affect the stability of the centromeric nucleosome, which is detrimental in the context of defective NDC80 tetramerization and can be compensated for by strengthening interactions among NDC80 complex components. [ABSTRACT FROM AUTHOR]

In higher fungi, lysine is biosynthesized via the α-aminoadipate (AAA) pathway, which differs from plants, bacteria, and lower fungi. The differences offer a unique opportunity to develop a molecular regulatory strategy for the biological control of plant parasitic nematodes, based on nematode-trapping fungi. In this study, in the nematode-trapping fungus model Arthrobotrys oligospora, we characterized the core gene in the AAA pathway, encoding α-aminoadipate reductase (Aoaar), via sequence analyses and through comparing the growth, and biochemical and global metabolic profiles of the wild-type and Aoaar knockout strains. Aoaar not only has α-aminoadipic acid reductase activity, which serves fungal L-lysine biosynthesis, but it also is a core gene of the non-ribosomal peptides biosynthetic gene cluster. Compared with WT, the growth rate, conidial production, number of predation rings formed, and nematode feeding rate of the ΔAoaar strain were decreased by 40–60%, 36%, 32%, and 52%, respectively. Amino acid metabolism, the biosynthesis of peptides and analogues, phenylpropanoid and polyketide biosynthesis, and lipid metabolism and carbon metabolism were metabolically reprogrammed in the ΔAoaar strains. The disruption of Aoaar perturbed the biosynthesis of intermediates in the lysine metabolism pathway, then reprogrammed amino acid and amino acid-related secondary metabolism, and finally, it impeded the growth and nematocidal ability of A. oligospora. This study provides an important reference for uncovering the role of amino acid-related primary and secondary metabolism in nematode capture by nematode-trapping fungi, and confirms the feasibility of Aoarr as a molecular target to regulate nematode-trapping fungi to biocontrol nematodes. [ABSTRACT FROM AUTHOR]

Background: Diabetic peripheral neuropathy (DPN) is a common neurological complication of diabetes mellitus without efficient interventions. Both lysine demethylase 5B (KDM5B) and sirtuin‐3 (SIRT3) have been found to regulate islet function and glucose homeostasis. KDM5B was predicted to bind to the SIRT3 promoter by bioinformatics. Here, we investigated whether KDM5B affected DPN development via modulating SIRT3. Methods: The db/db mice and high glucose‐stimulated Schwann cells (RSC96) were used as in vivo and in vitro models of DPN, respectively. Glucose level, glucose and insulin tolerance of mice were measured. Neurological function was evaluated by motor nerve conduction velocity (MNCV), tactile allodynia assay and thermal sensitivity assay. Adenosine triphosphate level, oxygen consumption rate, extracellular acidification rate, β‐oxidation rate, acetyl‐CoA level, acetylation levels and activities of long‐chain acyl CoA dehydrogenase (LCAD) and pyruvate dehydrogenase (PDH) were detected. Methyl thiazolyl tetrazolium assay was adopted to determine cell viability. Reactive oxygen species (ROS) production was detected by MitoSox staining. Western blotting for measuring target protein levels. Molecular mechanisms were investigated by co‐immunoprecipitine (Co‐IP), chromatin immunoprecipitation (ChIP) and luciferase reporter assay. Results: KDM5B was up‐regulated, while SIRT3 was down‐regulated in DPN models. SIRT3 overexpression or AMPK activation ameliorated mitochondrial metabolism dysfunction and ROS overproduction during DPN. KDM5B overexpression triggered mitochondrial metabolism disorder and oxidative stress via directly transcriptional inhibiting SIRT3 expression by demethylating H3K4me3 or indirectly repressing AMPK pathway‐regulated SIRT3 expression. Conclusion: KDM5B contributes to DPN via regulating SIRT3‐mediated mitochondrial glucose and lipid metabolism. KDM5B inhibition may be an effective intervention for DPN. [ABSTRACT FROM AUTHOR]

The transition from lean to obese states involves systemic metabolic remodeling that impacts insulin sensitivity, lipid partitioning, inflammation, and glycemic control. Here, we have taken a pharmacological approach to test the role of a nutrient-regulated chromatin modifier, lysine-specific demethylase (LSD1), in obesity-associated metabolic reprogramming. We show that systemic administration of an LSD1 inhibitor (GSK-LSD1) reduces food intake and body weight, ameliorates nonalcoholic fatty liver disease (NAFLD), and improves insulin sensitivity and glycemic control in mouse models of obesity. GSK-LSD1 has little effect on systemic metabolism of lean mice, suggesting that LSD1 has a context-dependent role in promoting maladaptive changes in obesity. In analysis of insulin target tissues we identified white adipose tissue as the major site of insulin sensitization by GSK-LSD1, where it reduces adipocyte inflammation and lipolysis. We demonstrate that GSK-LSD1 reverses NAFLD in a non-hepatocyte-autonomous manner, suggesting an indirect mechanism potentially via inhibition of adipocyte lipolysis and subsequent effects on lipid partitioning. Pair-feeding experiments further revealed that effects of GSK-LSD1 on hyperglycemia and NAFLD are not a consequence of reduced food intake and weight loss. These findings suggest that targeting LSD1 could be a strategy for treatment of obesity and its associated complications including type 2 diabetes and NAFLD. [ABSTRACT FROM AUTHOR]

Background: Although eradication therapy for chronic Helicobacter pylori (H. pylori) reduces the risk of gastric cancer (GC), its effectiveness is not complete. Therefore, it is also critically important to identifying those patients who remain at high risk after H. pylori eradication therapy. Accumulation of protein methylation is strongly implicated in cancer, and recent study showed that dimethylation of eEF1A lysine 55 (eEF1AK55me2) promotes carcinogenesis in vivo. We aimed to investigate the relationship between eEF1A dimethylation and H. pylori status, efficacy of eradication therapy, and GC risk in H. pylori-eradicated mucosa, and to reveal the potential downstream molecules of eEF1A dimethylation.Methods: Records of 115 patients (11 H. pylori-negative, 29 H. pylori-positive, 75 post-eradication patients) who underwent upper gastrointestinal endoscopy were retrospectively reviewed. The eEF1A dimethyl level was evaluated in each functional cell type of gastric mucosa by immunofluorescent staining. We also investigated the relationship between eEF1AK55me2 downregulation by CRISPR/Cas9 mediated deletion of Mettl13, which is known as a dimethyltransferase of eEF1AK55me2.Results: The level of eEF1A dimethylation significantly increased in the surface and basal areas of H. pylori-positive mucosa compared with the negative mucosa (surface, p = 0.0031; basal, p = 0.0036, respectively). The eEF1A dimethyl-levels in the surface area were significantly reduced by eradication therapy (p = 0.005), but those in the basal area were maintained even after eradication therapy. Multivariate analysis revealed that high dimethylation of eEF1A in the basal area of the mucosa was the independent factor related to GC incidence (odds ratio = 3.6611, 95% confidence interval = 1.0350-12.949, p = 0.0441). We also showed the relationship between eEF1A dimethylation and expressions of reprogramming factors, Oct4 and Nanog, by immunohistochemistry and in vitro genome editing experiments.Conclusions: The results indicated that H. pylori infection induced eEF1A dimethylation in gastric mucosa. The accumulation of dimethyl-eEF1A in the basal area of the mucosa might contribute to GC risk via regulation of reprograming factors in H. pylori eradicated-gastric mucosa. [ABSTRACT FROM AUTHOR]

Simple Summary: The histone methyltransferase SET domain-containing protein 8 (SETD8) methylates histone H4 lysine 20 and non-histone proteins such as p53. Our aim was to determine the involvement of SETD8 in endometrial cancer and its therapeutic potential and identify the downstream genes regulated by SETD8 via H4K20 methylation and the p53 signaling pathway. We confirmed that SETD8 expression was elevated in endometrial cancer tissues. Our results suggest that the suppression of SETD8 using siRNA or a selective inhibitor attenuated cell proliferation and promoted the apoptosis of endometrial cancer cells. In these cells, SETD8 regulates genes via H4K20 methylation and the p53 signaling pathway. We also identified the prognostically important genes related to apoptosis, such as those encoding KIAA1324 and TP73, in endometrial cancer. SETD8 is an important gene for carcinogenesis and progression of endometrial cancer via H4K20 methylation. The histone methyltransferase SET domain-containing protein 8 (SETD8), which methylates histone H4 lysine 20 (H4K20) and non-histone proteins such as p53, plays key roles in human carcinogenesis. Our aim was to determine the involvement of SETD8 in endometrial cancer and its therapeutic potential and identify the downstream genes regulated by SETD8 via H4K20 methylation and the p53 signaling pathway. We examined the expression profile of SETD8 and evaluated whether SETD8 plays a critical role in the proliferation of endometrial cancer cells using small interfering RNAs (siRNAs). We identified the prognostically important genes regulated by SETD8 via H4K20 methylation and p53 signaling using chromatin immunoprecipitation sequencing, RNA sequencing, and machine learning. We confirmed that SETD8 expression was elevated in endometrial cancer tissues. Our in vitro results suggest that the suppression of SETD8 using siRNA or a selective inhibitor attenuated cell proliferation and promoted the apoptosis of endometrial cancer cells. In these cells, SETD8 regulates genes via H4K20 methylation and the p53 signaling pathway. We also identified the prognostically important genes related to apoptosis, such as those encoding KIAA1324 and TP73, in endometrial cancer. SETD8 is an important gene for carcinogenesis and progression of endometrial cancer via H4K20 methylation. [ABSTRACT FROM AUTHOR]

Simple Summary: Epigenetic events, which comprise post-translational modifications of histone tails or DNA methylation, control gene expression by altering chromatin structure without change in the DNA sequence. Histone tails modifications are driven by specific cellular enzymes such as histone methyltransferases or histone acetylases, which play a key role in regulating diverse biological processes. Their alteration may have consequences on growth and tumorigenesis. Epigenetic regulations, that comprise histone modifications and DNA methylation, are essential to processes as diverse as development and cancer. Among the histone post-translational modifications, lysine methylation represents one of the most important dynamic marks. Here, we focused on methyltransferases of the nuclear binding SET domain 1 (NSD) family, that catalyze the mono- and di-methylation of histone H3 lysine 36. We review the loss of function mutations of NSD1 in humans that are the main cause of SOTOS syndrome, a disease associated with an increased risk of developing cancer. We then report the role of NSD1 in triggering tumor suppressive or promoter functions according to the tissue context and we discuss the role of NSD1 in melanoma. Finally, we examine the ongoing efforts to target NSD1 signaling in cancers. [ABSTRACT FROM AUTHOR]

Background: Parenteral nutrition (PN) is often a necessity for preterm infants; however, prolonged PN leads to gut atrophy, weakened gut barrier function, and a higher risk of intestinal infections. Peptide transporter-1 (PepT1) is a di- or tripeptide transporter in the gut and, unlike other nutrient transporters, its activity is preserved with the onset of intestinal atrophy from PN. As such, enteral amino acids in the form of dipeptides may be more bioavailable than free amino acids when atrophy is present.Objectives: In Yucatan miniature piglets with PN-induced intestinal atrophy, we sought to determine the structural and functional effects of enteral refeeding with lysine as a dipeptide, compared to free L-lysine.Methods: Piglets aged 7-8 days were PN-fed for 4 days to induce intestinal atrophy, then were refed with enteral diets with equimolar lysine supplied as lysyl-lysine (Lys-Lys; n = 7), free lysine (n = 7), or Lys-Lys with glycyl-sarcosine (n = 6; to determine whether competitive inhibition of Lys-Lys uptake would abolish PepT1-mediated effects). The diets provided lysine at 75% of the requirement and were gastrically delivered for a total of 18 hours. Whole-body and tissue-specific protein synthesis, as well as indices for gut structure and barrier function, were measured.Results: The villus height, mucosal weight, and free lysine concentration were higher in the Lys-Lys group compared to the other 2 groups (P < 0.05). Lysyl-lysine led to greater whole-body protein synthesis compared to free lysine (P < 0.05). Mucosal myeloperoxidase activity was lower in the Lys-Lys group (P < 0.05), suggesting less inflammation. The inclusion of glycyl-sarcosine with Lys-Lys abolished the dipeptide effects on whole-body and tissue-specific protein synthesis (P < 0.05), suggesting that improved lysine availability was mediated by PepT1.Conclusions: Improved intestinal structure and whole-body protein synthesis suggests that feeding strategies designed to exploit PepT1 may help to avoid adverse effects when enteral nutrition is reintroduced into the compromised guts of neonatal piglets. [ABSTRACT FROM AUTHOR]

Acetyl-CoA Carboxylase 1 catalyzes the conversion of acetyl-CoA to malonyl-CoA, the committed step of de novo fatty acid synthesis. As a master regulator of lipid synthesis, acetyl-CoA carboxylase 1 has been proposed to be a therapeutic target for numerous metabolic diseases. We have shown that acetyl-CoA carboxylase 1 activity is reduced in the absence of the lysine acetyltransferase NuA4 in Saccharomyces cerevisiae. This change in acetyl-CoA carboxylase 1 activity is correlated with a change in localization. In wild-type cells, acetyl-CoA carboxylase 1 is localized throughout the cytoplasm in small punctate and rod-like structures. However, in NuA4 mutants, acetyl-CoA carboxylase 1 localization becomes diffuse. To uncover mechanisms regulating acetyl-CoA carboxylase 1 localization, we performed a microscopy screen to identify other deletion mutants that impact acetyl-CoA carboxylase 1 localization and then measured acetyl-CoA carboxylase 1 activity in these mutants through chemical genetics and biochemical assays. Three phenotypes were identified. Mutants with hyper-active acetyl-CoA carboxylase 1 form 1 or 2 rod-like structures centrally within the cytoplasm, mutants with mid-low acetyl-CoA carboxylase 1 activity displayed diffuse acetyl-CoA carboxylase 1, while the mutants with the lowest acetyl-CoA carboxylase 1 activity (hypomorphs) formed thick rod-like acetyl-CoA carboxylase 1 structures at the periphery of the cell. All the acetyl-CoA carboxylase 1 hypomorphic mutants were implicated in sphingolipid metabolism or very long-chain fatty acid elongation and in common, their deletion causes an accumulation of palmitoyl-CoA. Through exogenous lipid treatments, enzyme inhibitors, and genetics, we determined that increasing palmitoyl-CoA levels inhibits acetyl-CoA carboxylase 1 activity and remodels acetyl-CoA carboxylase 1 localization. Together this study suggests yeast cells have developed a dynamic feed-back mechanism in which downstream products of acetyl-CoA carboxylase 1 can fine-tune the rate of fatty acid synthesis. [ABSTRACT FROM AUTHOR]

Haloarchaea with the capacity to degrade alkanes is promising to deal with petroleum pollution in hypersaline environments. However, only a limited number of haloarchaeal species are investigated, and their pathway and mechanism for alkane degradation remain unclear. In this study, Halogranum rubrum RO2-11, a haloarchaeal strain, verified the ability to degrade kerosene and hexadecane in 184 g/L NaCl, with 53% and 52% degradation rates after 9 and 4 days, respectively. Genome sequencing and gene annotation indicated that strain RO2-11 possesses a complete potential alkane-degrading pathway, of which alkane hydroxylases may include CYP450, AlmA, and LadA. Transcriptome and metabolome analyses revealed that the upregulation of related genes in TCA cycle, lysine biosynthesis, and acetylation may help improve hexadecane degradation. Additionally, an alternative degrading pathway of hexadecane based on dual-terminal β -oxidation may occur in strain RO2-11. It is likely to be the first report of alkane degradation by the genus Halogranum , which may be helpful for applications of oil-pollution bioremediation under high-salt conditions. [Display omitted] • Halogranum rubrum RO2-11 possesses a complete potential alkane-degrading pathway. • Hexadecane-degrading enzymes keep high activities even in the absence of alkane. • The degradation pathway involves alkane oxygenation and dual-terminal β -oxidation. • Upregulation of TCA cycle, lysine synthesis & acetylation may help for degradation. [ABSTRACT FROM AUTHOR]

Background: Sunflower is a promising protein source but data on amino acid (AA) digestibility are lacking in humans. Classically, the determination of AA digestibility requires ileal digesta sampling. The dual isotope method is minimally invasive but has not been compared to the conventional approach.Objectives: This study aimed to determine the true ileal digestibility of sunflower AAs in healthy volunteers who ate biscuits containing 15nitrogen (N) protein isolate, in comparison with the dual isotope method.Methods: Twelve healthy volunteers (men and women; 40.4 ± 10.5 years old; BMI, 23.7 ± 2.9 kg/m2) were equipped with a naso-ileal tube. For 4 hours, they consumed 9 repeated meals comprising 15N-sunflower protein biscuits together with 13carbon (C)-AAs, carried either in chocolate (SUN + Ch; n = 7) or apple puree (SUN + P; n = 5). Ileal digesta and blood were sampled throughout 8 hours after ingestion of the first meal. The 15N and 13C AA enrichments were measured in digesta to determine ileal digestibility directly and in plasma to determine lysine and threonine digestibility using the dual isotope method. Differences between methods and between vector groups were analyzed using paired and unpaired t-tests, respectively.Results: The ileal digestibility of sunflower indispensable AAs (IAA) was 89% ± 5.3%, with threonine and lysine having the lowest digestibility. In the SUN + Ch meal, IAA digestibility was 3% below that of SUN + P (P < 0.05). The mean free 13C-AA ileal digestibility was 98.1% ± 0.9%. No matter which matrix was used to carry 13C-AAs, plasma 15N and 13C-AA kinetics displayed a 1-hour offset. Digestibility obtained with the dual isotope method (70.4% ± 6.0% for threonine and 75.9% ± 22.3% for lysine) was below the target values.Conclusions: The ileal digestibility of IAAs from a sunflower isolate incorporated in a biscuit was close to 90% in healthy adults. Under our experimental conditions, the dual isotope method provided lower values than the usual method. Further protocol developments are needed to validate the equivalence between both methods. This trial was registered at clinicaltrials.gov as NCT04024605. [ABSTRACT FROM AUTHOR]

Background: Sorghum is the fifth most consumed cereal grain but limiting in the indispensable amino acid lysine. Complementing sorghum with lentils can improve the quality of sorghum-based diets. However, knowledge of lysine bioavailability in sorghum is lacking.Objectives: The study objectives were to determine the bioavailability of lysine in sorghum and to assess the effect of complementation of sorghum and lentils in a mixed-meal format.Methods: We studied 5 healthy young men (≤30 years; BMI <25 kg/m2) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each subject participated in 8 determinations in random order. On the reference diet, subjects received 4 amounts of L-lysine (5, 8, 12, and 15 mg. kg-1 . d-1) from a crystalline amino acid mixture patterned after egg protein. On the test diet, they received 3 levels of lysine (8.2, 12.5, and 15.7 mg. kg-1 . d-1) from sorghum, and on the complementation diet they received 1 level of lysine from a mixed meal of sorghum and lentils. The bioavailability of lysine in sorghum was estimated by comparing the IAAO response to the test diet with the IAAO response to the reference diet using the slope-ratio method. Effectiveness of complementation was assessed by comparing the IAAO response to the mixed meal to the IAAO response to the test protein.Results: The bioavailability of lysine from sorghum was 94%. Upon complementation with lentils, there was a decline in the oxidation of L-[1-13C] phenylalanine by 19% (P < 0.0495), reflecting an improvement in available lysine in the mixed meal due to increased lysine intake.Conclusions: Although the bioavailability of lysine in sorghum is high, its lysine content is limiting. Complementation with lentils in a 1:1 ratio is recommended to achieve the lysine requirement for adult men consuming a sorghum-based diet. This trial was registered at clinicaltrials.gov as NCT03411005. [ABSTRACT FROM AUTHOR]

Histone posttranslational modifications (HPTMs) are crucial epigenetic mechanisms regulating various biological events. Different types of HPTMs characterize and shape functional chromatin states alone or in combination, and dedicated effector proteins selectively recognize these modifications for gene expression. The dysregulation of HPTM recognition events takes part in human diseases. With the application of mass spectrometry- (MS-) based proteomics, novel histone lysine acylation has been successively discovered, e.g., propionylation, butyrylation, 2-hydroxyisobutyrylation, β-hydroxybutyrylation, malonylation, succinylation, crotonylation, glutarylation, and lactylation. These nine types of modifications expand the repertoire of HPTMs and regulate chromatin remodeling, gene expression, cell cycle, and cellular metabolism. Recent researches show that HPTMs have a close connection with the pathogenesis of cancer, metabolic diseases, neuropsychiatric disorders, infertility, kidney diseases, and acquired immunodeficiency syndrome (AIDS). This review focuses on the chemical structure, sites, functions of these novel HPTMs, and underlying mechanism in gene expression, providing a glimpse into their complex regulation in health and disease. [ABSTRACT FROM AUTHOR]

Summary: Lysine is the main limiting essential amino acid (EAA) in the rice seeds, which is a major energy and nutrition source for humans and livestock. In higher plants, the rate‐limiting steps in lysine biosynthesis pathway are catalysed by two key enzymes, aspartate kinase (AK) and dihydrodipicolinate synthase (DHDPS), and both are extremely sensitive to feedback inhibition by lysine. In this study, two rice AK mutants (AK1 and AK2) and five DHDPS mutants (DHDPS1–DHDPS5), all single amino acid substitution, were constructed. Their protein sequences passed an allergic sequence‐based homology alignment. Mutant proteins were recombinantly expressed in Escherichia coli, and all were insensitive to the lysine analog S‐(2‐aminoethyl)‐l‐cysteine (AEC) at concentrations up to 12 mm. The AK and DHDPS mutants were transformed into rice, and free lysine was elevated in mature seeds of transgenic plants, especially those expressing AK2 or DHDPS1, 6.6‐fold and 21.7‐fold higher than the wild‐type (WT) rice, respectively. We then engineered 35A2D1L plants by simultaneously expressing modified AK2 and DHDPS1, and inhibiting rice LKR/SDH (lysine ketoglutaric acid reductase/saccharopine dehydropine dehydrogenase). Free lysine levels in two 35A2D1L transgenic lines were 58.5‐fold and 39.2‐fold higher than in WT and transgenic rice containing native AK and DHDPS, respectively. Total free amino acid and total protein content were also elevated in 35A2D1L transgenic rice. Additionally, agronomic performance analysis indicated that transgenic lines exhibited normal plant growth, development and seed appearance comparable to WT plants. Thus, AK and DHDPS mutants may be used to improve the nutritional quality of rice and other cereal grains. [ABSTRACT FROM AUTHOR]

Our previous studies have demonstrated that Jian-Pi-Yi-Shen formula (JPYSF), a traditional Chinese herbal decoction, has a renoprotective effect in 5/6 nephrectomy-induced chronic kidney injury. However, the role and potential mechanisms of JPYSF in the treatment of acute kidney injury (AKI) remain unknown. This study was designed to test the beneficial effect of JPYSF in an AKI mouse model and to investigate the underlying mechanism by using metabolomics analysis. The AKI mouse model was induced by a single intraperitoneal injection of cisplatin at a dose of 20 mg/kg. The mice in the treatment group were pretreated orally with JPYSF (18.35 g/kg/d) for 5 days before cisplatin injection. Seventy-two hours after cisplatin injection, serum and kidney samples were collected for biochemical and histological examination. Ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF/MS) was applied to analyze metabolic profiling variations in the kidney. The results showed that pretreatment with JPYSF obviously reduced the levels of serum creatinine and blood urea nitrogen and alleviated renal pathological injury in AKI mice. Orthogonal partial least-squares discriminant analysis (OPLS-DA) score plot revealed a clear separation between the AKI and AKI + JPYSF group. A total of 68 and 87 significantly differentially expressed metabolites were identified in the kidney of AKI mice responding to JPYSF treatment in negative and positive ion mode, respectively. The pivotal pathways affected by JPYSF included vitamin B6 metabolism, alanine, aspartate and glutamate metabolism, lysine biosynthesis, and butanoate metabolism. In conclusion, JPYSF can protect the kidney from cisplatin-induced AKI, which may be associated with regulating renal metabolic disorders. [ABSTRACT FROM AUTHOR]

Background: Lysine rich foods such as milk and legumes serve as important food additions to the lysine deficient cereal-based diets of vegetarian populations in low- and middle-income countries (LMICs) to alleviate the risk of quality corrected dietary protein inadequacy. Dietary protein quality can be determined by estimating the metabolic availability (MA) of lysine.Objectives: The study aimed to estimate the MA of lysine in spray-dried cow milk powder (SMP), heat-treated spray-dried cow milk powder (HSMP), and a habitually consumed cereal-legume based vegetarian meal (VM), using the indicator amino acid oxidation (IAAO) slope-ratio method.Methods: The MA of lysine in SMP, HSMP, and VM was estimated in 7 healthy young men aged 19-24 y with BMI of 21.5 ± 0.5 kg/m2 in a repeated measures design. The IAAO response slopes with 2 graded lysine intakes (10.5 and 15.0 mg·kg-1·d-1) from the SMP and VM were compared with the response slope generated with 3 graded crystalline lysine intakes (6.0, 10.5, and 15.0 mg·kg-1·d-1) at the subrequirement level. To produce HSMP, pasteurized cow milk was heat treated and spray dried. The MA of lysine in HSMP was tested at a single level of lysine intake (15 mg·kg-1·d-1). A total of 8 IAAO experiments were conducted on each participant in randomized order. The IAAO slopes were estimated using a linear mixed-effect regression model.Results: The MA of lysine in SMP, HSMP, and VM was 91.9%, 69.9%, and 86.6% respectively.Conclusions: Heat treatment reduced the MA of lysine by 22% in HSMP compared with SMP in healthy Indian adults. The lysine MA estimates can be used to optimize lysine limited cereal-based diets, with the addition of appropriately processed legumes and milk powder, to meet the protein requirement. This trial was registered at Clinical Trials Registry of India (http://ctri.nic.in) as CTRI/2019/08/020568. [ABSTRACT FROM AUTHOR]

Background: Pearl millet is the chief source of energy in the diet in some developing regions, but has a limited amount of indispensable amino acid lysine. Complementation with pulses like lentils can improve the protein quality of millet diets, but the knowledge of lysine bioavailability (BA) in millet and lentils is lacking.Objectives: The study objectives were to determine the BA of lysine in millet and lentils separately and to assess the effect of complementation of millet and lentils in a mixed meal format.Methods: We studied 9 healthy young men (≤30 y; BMI <25) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each subject completed 7 or 8 experiments in random order. On the reference diet, subjects received 4 graded levels of L-lysine (5, 8, 12, and 15 mg·kg-1.d-1) from a crystalline amino acid mixture patterned after egg protein; on the test diets, they received 3 levels of lysine (10, 12, and 15 mg·kg-1.d-1) from either steamed millet or stewed lentils; and on the complementation diet, they received 1 level of lysine from a mixed meal of steamed millet and stewed lentils. The BA of lysine and the effect of complementation were assessed by comparing the IAAO responses to the test diets and the complementation diet with the IAAO response to L-lysine intakes in the reference protein, using the slope ratio method.Results: The BA of lysine was 97% from millet and 80% from lentils. Complementation of steamed millet with stewed lentils decreased the oxidation of L-[1-13C] phenylalanine by 27% (P < 0.05), signifying improved quality of the combined millet and lentil protein.Conclusions: Lysine has high BA but is still limiting in steamed pearl millet. Complementation with lentils in a 2:1 ratio is recommended to meet the lysine and protein requirements for adult men consuming a millet-based diet. This trial was registered at clinicaltrials.gov as NCT03674736 and NCT03339167. [ABSTRACT FROM AUTHOR]

Accumulation of advanced glycation end products (AGEs) and activation of the receptor for AGEs (RAGE) are implicated in the progression of pathologies associated with aging, chronic inflammation, diabetes, and cellular stress. RAGE activation is also implicated in cardiovascular complications of type 2 diabetes, such as nephropathy, retinopathy, accelerated vascular diseases, and cardiomyopathy. Studies investigating the effects of AGE/RAGE axis activation on skeletal muscle oxidative stress and metabolism are more limited. We tested whether a high-fat diet (HFD) would alter circulating AGE concentration, skeletal muscle AGE accumulation, and oxidative stress in wild-type and RAGE-deficient mice. The physiological significance of AGE/RAGE axis activation in HFD-fed mice was evaluated in terms of exercise tolerance and mitochondrial respiratory chain complex activity. HFD elicited adiposity, abnormal fat distribution, and oral glucose intolerance. HFD also induced accumulation of Nε-carboxymethyl-l-lysine, increased protein carbonyl levels, and impaired respiratory chain complex activity in soleus muscle. Ablation of RAGE had no effects on weight gain and oral glucose tolerance in HFD-fed mice. Peak aerobic capacity and mitochondrial cytochrome-c oxidase activity were restored in HFD-fed RAGE−/− mice. We concluded that RAGE signaling plays an important role in skeletal muscle homeostasis of mice under metabolic stress. Novelty HFD in mice induces accumulation of AGEs, oxidative stress, and mitochondrial dysfunction in the soleus muscle. RAGE, the multi-ligand receptor for AGEs, modulates oxidative stress and mitochondrial electron transport chain function in the soleus muscle of HFD-fed mice. [ABSTRACT FROM AUTHOR]

Background: Legumes are an excellent plant source of the limiting indispensable amino acid (IAA) lysine in vegetarian, cereal-based diets. However, their digestibility is poor largely because of their antiprotease content. Extrusion can enhance digestibility by inactivating trypsin inhibitors and thus potentially improve the protein quality of legumes.Objective: We measured the digestibility of extruded chickpea and yellow pea protein with use of a dual stable isotope method in moderately stunted South Indian primary school children.Methods: Twenty-eight moderately stunted children (height-for-age z scores <-2.0 SD and >-3.0 SD) aged 6-11 y from low to middle socioeconomic status were randomly assigned to receive a test protein (extruded intrinsically [2H]-labeled chickpea or yellow pea) along with a standard of U-[13C]-spirulina protein to measure amino acid (AA) digestibility with use of a dual stable isotope method. Individual AA digestibility in the test protein was calculated by the ratios of AA enrichments in the test protein to the standard protein in the food and their appearance in blood plasma collected at 6 and 6.5 h during the experiment, representing a plateau state.Results: The mean AA digestibility of extruded chickpea and yellow pea protein in moderately stunted children (HAZ; -2.86 to -1.2) was high and similar in both extruded test proteins (89.0% and 88.0%, respectively, P = 0.83). However, lysine and proline digestibilities were higher in extruded chickpea than yellow pea (79.2% compared with 76.5% and 75.0% compared with 72.0%, respectively, P < 0.02).Conclusion: Extruded chickpea and yellow pea protein had good IAA digestibility in moderately stunted children, which was 20% higher than an earlier report of their digestibility when pressure-cooked, measured by the same method in adults. Higher digestibility of lysine and proline highlights better retention of these AA in chickpea during extrusion-based processing. Extrusion might be useful for developing high-quality protein foods from legumes. This trial was registered at www.ctri.nic.in as CTRI/2018/03/012439. [ABSTRACT FROM AUTHOR]

Objective(s): Isothiocyanates (ITCs) are biologically active plant secondary metabolites capable of mediating various biological effects including modulation of the epigenome. Our aim was to characterize the effect of allyl isothiocyanate (AITC) on lysine acetylation and methylation marks as a potential epigenetic-induced anti-melanoma strategy. Methods: Our malignant melanoma model consisted of (1) human (A375) and murine (B16-F10) malignant melanoma as well as of human; (2) brain (VMM1) and lymph node (Hs 294T) metastatic melanoma; (3) non-melanoma epidermoid carcinoma (A431) and (4) immortalized keratinocyte (HaCaT) cells subjected to AITC. Cell viability, histone deacetylases (HDACs) and acetyltransferases (HATs) activities were evaluated by the Alamar blue, Epigenase HDAC Activity/Inhibition and EpiQuik HAT Activity/Inhibition assay kits, respectively, while their expression levels together with those of lysine acetylation and methylation marks by western immunoblotting. Finally, apoptotic gene expression was assessed by an RT-PCR-based gene expression profiling methodology. Results: AITC reduces cell viability, decreases HDACs and HATs activities and causes changes in protein expression levels of various HDACs, HATs, and histone methyl transferases (HMTs) all of which have a profound effect on specific lysine acetylation and methylation marks. Moreover, AITC regulates the expression of a number of genes participating in various apoptotic cascades thus indicating its involvement in apoptotic induction. Conclusions: AITC exerts a potent epigenetic effect suggesting its potential involvement as a promising epigenetic-induced bioactive for the treatment of malignant melanoma. [ABSTRACT FROM AUTHOR]

Early brain damage (EBI) following subarachnoid hemorrhage (SAH) is a long-lasting condition with a high occurrence. However, treatment options are restricted. Wu-zhu-yu Decoction (WZYD) can treat headaches and vomiting, which are similar to the early symptoms of subarachnoid hemorrhage (SAH). However, it is yet unknown if WZYD can reduce EBI following SAH and its underlying mechanisms. This study aimed to investigate whether WZYD protects against EBI following SAH by inhibiting oxidative stress through activating nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling via Sirtuin 6 (SIRT6)-mediated histone H3 lysine 56 (H3K56) deacetylation. In the current investigation, the principal components of WZYD were identified using high-performance liquid chromatography-diode array detection (HPLC-DAD). The SAH model in rats using the internal carotid artery plug puncture approach and the SAH model in primary neurons using hemoglobin incubation were developed. WZYD with different doses (137 mg kg−1, 274 mg kg−1, 548 mg kg−1) and the positive drug–Nimodipine (40 mg kg−1) were intragastrically administered in SAH model rats, respectively. The PC12 cells were cultured with corresponding medicated for 24h. In our investigation, neurological scores, brain water content, Evans blue leakage, Nissl staining, TUNEL staining, oxidative stress, expression of apoptosis-related proteins, and Nrf2/HO-1 signaling were evaluated. The interaction between SIRT6 and Nrf2 was detected by co-immunoprecipitation. SIRT6 knockdown was used to confirm its role in WZYD's neuroprotection. The WZYD treatment dramatically reduced cerebral hemorrhage and edema, and enhanced neurological results in EBI following SAH rats. WZYD administration inhibited neuronal apoptosis via reducing the expression levels of Cleaved cysteinyl aspartate specific proteinase-3(Cleaved Caspase-3), cysteinyl aspartate specific proteinase-3(caspase-3), and Bcl-2, Associated X Protein (Bax) and increasing the expression of B-cell lymphoma-2(Bal2). It also decreased reactive oxygen species and malondialdehyde levels and increased Nrf2 and HO-1 expression in the rat brain after SAH. In vitro, WZYD attenuated hemoglobin-induced cytotoxicity, oxidative stress and apoptosis in primary neurons. Mechanistically, WZYD enhanced SIRT6 expression and H3K56 deacetylation, activated Nrf2/HO-1 signaling, and promoted the interaction between SIRT6 and Nrf2. Knockdown of SIRT6 abolished WZYD-induced neuroprotection. WZYD attenuates EBI after SAH by activating Nrf2/HO-1 signaling through SIRT6-mediated H3K56 deacetylation, suggesting its therapeutic potential for SAH treatment. The graph created with BioRender (https://biorender.com). The caption for the abstract graphic: WZYD alleviated SAH symptoms by activating SIRT6/Nrf2/HO-1 antioxidant system and reducing pyroptosis in SAH rats. SIRT6 could directly bind to Nrf2, and SIRT6 could deacetylate the H3K56Ac site of the promoter of Nrf2 target genes, thus promoting the expression antioxidant of gene HO-1. [Display omitted] • Wu-zhu-yu Decoction (WZYD) ameliorated EBI after SAH in rats. • WZYD activated the Nrf2 antioxidant system and reduced oxidative stress and cell death. • WZYD activated the Nrf2 antioxidant system via targeting of SIRT6. • The knockdown of SIRT6 reversed the positive effects of activating the antioxidant system in vivo by WZYD. [ABSTRACT FROM AUTHOR]

Recent studies have made significant progress in identifying distinct populations of peripheral neurons involved in itch transmission, whereas the cellular identity of spinal interneurons that contribute to itch processing is still a debate. Combining genetic and pharmacological ablation of spinal excitatory neuronal subtypes and behavioral assays, we demonstrate that spinal somatostatin-positive (SOM) excitatory interneurons transmit pruritic sensation. We found that the ablation of spinal SOM/Lbx1 (SOM) neurons caused significant attenuation of scratching responses evoked by various chemical pruritogens (chemical itch). In an attempt to identify substrates of spinal itch neural circuit, we observed that spinal SOM neurons partially overlapped with neurons expressing natriuretic peptide receptor A (Npra), the receptor of peripheral itch transmitter B-type natriuretic peptide. Spinal SOM neurons, however, did not show any overlap with itch transmission neurons expressing gastrin-releasing peptide receptor in the dorsal spinal cord, and the gastrin-releasing peptide-triggered scratching responses were intact after ablating spinal SOM neurons. Dual ablation of SOM and Npra neurons in the spinal cord reduced chemical itch responses to a greater extent than ablation of SOM or Npra neurons alone, suggesting the existence of parallel spinal pathways transmitting chemical itch. Furthermore, we showed that SOM peptide modulated itch processing through disinhibition of somatostatin receptor 2A-positive inhibitory interneuron. Together, our findings reveal a novel spinal mechanism for sensory encoding of itch perception. [ABSTRACT FROM AUTHOR]

Background: Bronchiolitis is associated with a greater risk of developing recurrent wheezing, but with currently available tools, it is impossible to know which infants with bronchiolitis will develop this condition. This preliminary prospective study aimed to assess whether urine metabolomic analysis can be used to identify children with bronchiolitis who are at risk of developing recurrent wheezing.Methods: Fifty-two infants <1 year old treated in the emergency department at University Hospital of Padova for acute bronchiolitis were enrolled (77% tested positive for respiratory syncytial virus [RSV]). Follow-up visits were conducted for 2 years after the episode of bronchiolitis. Untargeted metabolomic analyses based on mass spectrometry were performed on urine samples collected from infants with acute bronchiolitis. Data modeling was based on univariate and multivariate data analyses.Results: We distinguished children with and those without postbronchiolitis recurrent wheeze, defined as ≥3 episodes of physician-diagnosed wheezing. Pathway overrepresentation analysis pointed to a major involvement of the citric acid cycle (P < .001) and some amino acids (lysine, cysteine, and methionine; P ≤ .015) in differentiating between these 2 groups of children.Conclusion: This is the first study showing that metabolomic profiling of urine specimens from infants with bronchiolitis can be used to identify children at increased risk of developing recurrent wheezing. [ABSTRACT FROM AUTHOR]

The gram-negative anaerobe Porphyromonas gingivalis is not only a keystone periodontal pathogen but also an emerging systemic pathogen. Although the newly discovered protein post-translational modification (PTM), lysine succinylation (Ksuc), appears to play an important role in modulating metabolic processes in bacteria, this PTM has not been investigated in P gingivalis. In this study, we used a highly sensitive proteomics approach combining affinity enrichment with high-resolution liquid chromatography coupled with tandem mass spectrometry to examine Ksuc in P gingivalis. In total, 345 Ksuc sites in 233 proteins were identified and determined to be involved in a variety of cellular processes. In the region surrounding Ksuc sites, lysine residues were drastically overrepresented and sequence motifs with succinyl-lysine flanked by a lysine at the +3 or +6 positions appear to be unique to this pathogen. Additionally, our results suggest a crosstalk between Ksuc and glycosylation, but the overlap between Ksuc and acetylation in P gingivalis is quite different from that observed in other organisms. Notably, Ksuc was observed in proteins associated with established virulence factors, including gingipains, fimbriae, RagB, and PorR. Moreover, products of the factors necessary for P gingivalis in vitro survival (18.5%) were found to be succinylated at lysine sites and the same was observed in products of fitness factors for P gingivalis survival in both abscess and epithelial cell colonization environments (12%). Collectively, these results suggest that Ksuc may be a new mechanism in modulating the virulence, adaptation, and fitness of P gingivalis. [ABSTRACT FROM AUTHOR]

Background: Histone methylation has been considered as one of the epigenetic mechanisms of carcinogenesis and progression. Researches on the correlation between histone lysine methylation and gastric cancer (GC) will help in finding novel epigenetic biomarkers for monitoring cancers.Aims: The study detected the expression patterns of histone 3 lysine 9 dimethylation (H3K9me2), histone 3 lysine 9 trimethylation (H3K9me3), and histone 3 lysine 27 trimethylation (H3K27me3) in GC tissues and evaluated their clinical merit for GC patients.Methods: One hundred thirty-three paraffin-embedded GC samples were examined by immunohistochemistry for the histone markers: H3K9me2, H3K9me3, and H3K27me3. The relationship and clinicopathological significance of the three lysine methylations on histone H3 with GC were assessed by Paired t test, Chi-square test, Kaplan-Meier analysis with log-rank test, and Cox proportional hazard analyses.Results: Strong positive immunostaining of H3K9me2, H3K9me3, and H3K27me3 was observed in cancerous tissues than in their counterpart non-cancer tissues. Higher expression patterns of H3K9me2, H3K9me3, and H3K27me3 significantly related to differentiation degree, lymph nodes metastases, and pathological TNM staging in GC. The GC patients with low scoring of the three markers implied long survival period and best prognosis. In contrast, the patients' survival time was significantly shorter if their cancerous tissues presented high expression of the three markers.Conclusions: H3K9me2, H3K9me3, and H3K27me3 expression patterns closely relate to clinicopathological features and may be the independent risk factors for the survival of GC patients. The combined pattern of the three markers rather than an individual marker is considered to more accurately evaluate the outcome of GC patients. [ABSTRACT FROM AUTHOR]

Objective: Binge‐eating episodes are recurrent and are defining features of several eating disorders. Thus binge‐eating episodes might influence eating disorder development of which exact underlying mechanisms are still largely unknown. Methods: Here we focused on the transcriptional regulation of the endocannabinoid system, a potent regulator of feeding behavior, in relevant rat brain regions, using a rat model in which a history of intermittent food restriction and a frustration stress induce binge‐like palatable food consumption. Results: We observed a selective down‐regulation of fatty acid amide hydrolase (faah) gene expression in the hypothalamus of rats showing the binge‐eating behavior with a consistent reduction in histone 3 acetylation at lysine 4 of the gene promoter. No relevant changes were detected for any other endocannabinoid system components in any brain regions under study, as well as for the other epigenetic mechanisms investigated (DNA methylation and histone 3 lysine 27 methylation) at the faah gene promoter. Discussion: Our findings suggest that faah transcriptional regulation is a potential biomarker of binge‐eating episodes, with a relevant role in the homeostatic regulation of food intake. [ABSTRACT FROM AUTHOR]

Danggui Buxue decoction (DBD) is a classic herbal decoction consisting of Astragali Radix (AR) and Angelica Sinensis Radix (ASR) with a 5:1 wt ratio, which can supplement 'blood' and 'qi' (vital energy) for the treatment of clinical diseases. According to Traditional Chinese Medicine (TCM) theory, dementia is induced by Blood deficiency and Qi weakness, which causes a decline in cognition. However, the underlying mechanisms of DBD improving cognition deficits in neurodegenerative disease are no clear. This study aims at revealing the underlying mechanisms of DBD plays a protective role in the cognitive deficits and pathology process of Alzheimer's disease (AD). The APP/PS1 (Mo/HuAPP695swe/PS1-dE9) double transgenic mice were adopted as an experimental model of AD. Qualitative and quantitative analysis of 3 compounds in DBT was analyzed by HPLC. Morris water maze test, Golgi staining and electrophysiology assays were used to evaluate the effects of DBD on cognitive function and synaptic plasticity in APP/PS1 mice. Western blot, immunofluorescence and Thioflavin S staining were used for the pathological evaluation of AD. Monitoring the level of ATP, mitochondrial membrane potential, SOD and MDA to evaluate the mitochondrial function, and with the usage of qPCR and CHIP for the changes of histone post-translational modification. In the current study, we found that DBD could effectively attenuate memory impairments and enhance long-term potentiation (LTP) with concurrent increased expression of memory-associated proteins. DBD markedly decreased Aβ accumulation in APP/PS1 mice by decreasing the phosphorylation of APP at the Thr668 level but not APP, PS1 or BACE1. Further studies demonstrated that DBD restored mitochondrial biogenesis deficits and mitochondrial dysfunction. Finally, the restored mitochondrial biogenesis and cognitive deficits are under HADC2-mediated histone H4 lysine 12 (H4K12) acetylation at the peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α) and N-methyl-D-aspartate receptor type 2B (GluN2B) promoters. These findings reveal that DBD could ameliorate mitochondrial biogenesis and cognitive deficits by improving H4K12 acetylation. DBD might be a promising complementary drug candidate for AD treatment. Treated by DBD, the level of phosphorylation of APP was downregulated to cause Aβ deposition to decrease in APP/PS1 mice. Meanwhile, DBD restored mitochondrial biogenesis by the HDAC2/H4K12 acetylation/PGC-1α pathway and improved synaptic plasticity through the HDAC2/H4K12 acetylation/GluN2B pathway. In conclusion, DBD could ameliorate cognitive deficits in APP/PS1 mice. [Display omitted] • DBD ameliorated cognitive deficits in APP/PS1 mice. • DBD attenuated Aβ deposition by decreasing the phosphorylation of APP at the Thr668 level. • DBD restored mitochondrial biogenesis by the HDAC2/H4K12 acetylation/PGC-1α pathway. • DBD improved synaptic plasticity through the HDAC2/H4K12 acetylation/GluN2B pathway. [ABSTRACT FROM AUTHOR]

Iron‑sulfur clusters (Fe S) are one of the most primitive and ubiquitous cofactors used by various enzymes in multiple pathways. Biosynthesis of Fe S is a complex multi-step process that is tightly regulated and requires multiple machineries. IBA57, along with ISCA1 and ISCA2, play a role in maturation of [4Fe-4S] clusters which are required for multiple mitochondrial enzymes including mitochondrial Complex I, Complex II, lipoic acid synthase, and aconitase. Pathogenic variants in IBA57 have been associated with multiple mitochondrial dysfunctions syndrome 3 (MMDS3) characterized by infantile to early childhood-onset psychomotor regression, optic atrophy and nonspecific dysmorphism. Here we report a female proband who had prenatal involvement including IUGR and microcephaly and developed subacute psychomotor regression at the age of 5 weeks in the setting of preceding viral infection. Brain imaging revealed cortical malformation with polymicrogyria and abnormal signal alteration in brainstem and spinal cord. Biochemical analysis revealed increased plasma glycine and hyperexcretion of multiple organic acids in urine, raising the concern for lipoic acid biosynthesis defects and mitochondrial Fe S assembly defects. Molecular analysis subsequently detected compound heterozygous variants in IBA57 , confirming the diagnosis of MMDS3. Although the number of MMDS3 patients are limited, certain degree of genotype-phenotype correlation has been observed. Unusual brain imaging in the proband highlights the need to include mitochondrial disorders as differential diagnoses of structural brain abnormalities. Lastly, in addition to previously known biomarkers including high blood lactate and plasma glycine levels, the increase of 2-hydroxyadipic and 2-ketoadipic acids in urine organic acid analysis, in the appropriate clinical context, should prompt an evaluation for the lipoic acid biosynthesis defects and mitochondrial Fe S assembly defects. [ABSTRACT FROM AUTHOR]

Lysine, as an essential amino acid, predominantly undergoes metabolic processes through the saccharopine pathway, whereas a smaller fraction follows the pipecolic acid pathway. Although the liver is considered the primary organ for lysine metabolism, it is worth noting that lysine catabolism also takes place in other tissues and organs throughout the body, including the brain. Enzyme deficiency caused by pathogenic variants in its metabolic pathway may lead to a series of neurometabolic diseases, among which glutaric aciduria type 1 and pyridoxine-dependent epilepsy have the most significant clinical manifestations. At present, through research, we have a deeper understanding of the multiple pathophysiological mechanisms related to these diseases, including intracerebral accumulation of neurotoxic metabolites, imbalance between GABAergic and glutamatergic neurotransmission, energy deprivation due to metabolites, and the dysfunction of antiquitin. Because of the complexity of these diseases, their clinical manifestations are also diverse. The early implementation of lysine-restricted diets and supplementation with arginine and carnitine has reported positive impacts on the neurodevelopmental outcomes of patients. Presently, there is more robust evidence supporting the effectiveness of these treatments in glutaric aciduria type 1 compared with pyridoxine-dependent epilepsy. [ABSTRACT FROM AUTHOR]

Summary: l‐lysine catabolic routes in plants include the saccharopine pathway to α‐aminoadipate and decarboxylation of lysine to cadaverine. The current review will cover a third l‐lysine metabolic pathway having a major role in plant systemic acquired resistance (SAR) to pathogen infection that was recently discovered in Arabidopsis thaliana. In this pathway, the aminotransferase AGD2‐like defense response protein (ALD1) α‐transaminates l‐lysine and generates cyclic dehydropipecolic (DP) intermediates that are subsequently reduced to pipecolic acid (Pip) by the reductase SAR‐deficient 4 (SARD4). l‐pipecolic acid, which occurs ubiquitously in the plant kingdom, is further N‐hydroxylated to the systemic acquired resistance (SAR)‐activating metabolite N‐hydroxypipecolic acid (NHP) by flavin‐dependent monooxygenase1 (FMO1). N‐hydroxypipecolic acid induces the expression of a set of major plant immune genes to enhance defense readiness, amplifies resistance responses, acts synergistically with the defense hormone salicylic acid, promotes the hypersensitive cell death response and primes plants for effective immune mobilization in cases of future pathogen challenge. This pathogen‐inducible NHP biosynthetic pathway is activated at the transcriptional level and involves feedback amplification. Apart from FMO1, some cytochrome P450 monooxygenases involved in secondary metabolism catalyze N‐hydroxylation reactions in plants. In specific taxa, pipecolic acid might also serve as a precursor in the biosynthesis of specialized natural products, leading to C‐hydroxylated and otherwise modified piperidine derivatives, including indolizidine alkaloids. Finally, we show that NHP is glycosylated in Arabidopsis to form a hexose‐conjugate, and then discuss open questions in Pip/NHP‐related research. [ABSTRACT FROM AUTHOR]

Background: l-lysine (Lys) is a critical dietary nutrient for mammary gland development and milk production. However, the specific pathways of Lys utilization and how milk protein synthesis is affected in bovine mammary epithelial cells (BMECs) are poorly understood.Objective: We aimed to investigate the effects of Lys on milk protein synthesis and the mechanism of Lys uptake and catabolism in BMECs.Methods: BMECs were cultured in 0, 0.5, 1.0, 1.5, 2.0, 5.0, and 10.0 mmol Lys/L to detect cell viability, or cultured in 0-2.0 mmol Lys/L with l-[ring-3H5] phenylalanine to study the effect of Lys on protein turnover, or cultured in Krebs buffer with [U-14C] l-Lys to quantify Lys metabolism. In some experiments, BMECs were cultured in a conditioned medium alone or including 1.0 mmol Lys/L and 2-amino-endo-bicyclo [2.2.1] heptane-2-carboxylic acid (BCH) for 24 h to analyze the expression of amino acid transporter B (0+) (ATB0,+), mammalian target of rapamycin (mTOR), and Janus kinase 2 (JAK2)-signal transducer and activator of transcription 5 (STAT5) pathways.Results: Including 1.0 mmol Lys/L in cultures increased cell viability by 17-47% and protein synthesis by 7-23%, whereas protein degradation was inhibited by 4-64% compared with BMECs cultured with 0, 0.5, or 2.0 mmol Lys/L (all P ≤ 0.05). Studies that used [U-14C] l-Lys showed that most Lys was incorporated into proteins (90%), whereas the remainder was either oxidized into CO2 (4%) or used as a substrate for aspartate (3%) and histidine synthesis (3%). Furthermore, Lys significantly increased expression of ATB0,+ (71% mRNA and 44% protein), STAT5 (27% mRNA and 21% phosphorylated proteins), and mTOR (51% mRNA and 22% phosphorylated proteins) compared with cells without Lys.Conclusions: Lys promoted protein synthesis, mostly through enhancing uptake by ATB0,+ and the mTOR and JAK2-STAT5 pathways. Understanding the utilization of Lys in BMECs provides insights into the role of amino acid nutrition in bovine milk production. [ABSTRACT FROM AUTHOR]

Protein turnover is required for muscle growth and regeneration and several proteolytic enzymes, including the calpains, degrade myofibrillar proteins during this process. In a previous experiment, phenotypic differences were observed between μ-calpain knockout (KO) and wild type (WT) mice, including nutrient accretion and fiber type differences. These changes were particularly evident as the animals aged. Thus, we utilized 18 mice (9 KO and 9 WT) to compare transcript abundance to identify differentially expressed genes (DEGs) at 52 wk of age. A total of 55 genes were differentially expressed, including adiponectin, phosphoenolpyruvate carboxykinase 1, uncoupling protein 1, and lysine deficient protein kinase 2. These genes were analyzed for over- and underrepresented gene ontology (GO) terms. Several GO terms, including response to cytokine, response to interferon-beta, regulation of protein phosphorylation, and hydrolase activity, were identified as overrepresented. Pathways related to taurine biosynthesis, nitric oxide synthase signaling, amyloid processing, and L-cysteine degradation were also identified. Our results are consistent with previous experiments, in that identified DEGs may explain, at least in part, some of the phenotypic differences between μ-calpain KO and WT mice. Clearly muscle growth and maintenance are complex, multifaceted processes. Genes affected by the silencing of the μ-calpain gene have been identified, but the relationship between μ-calpain and these pathways requires further investigation. [ABSTRACT FROM AUTHOR]

Peptides that exhibit enzymatic or hormonal activities are regulatory factors and desirable therapeutic drugs because of their high target specificity and minimal side effects. Unfortunately, these drugs are susceptible to enzymatic degradation, leading to their rapid elimination and thereby demanding frequent dosage. Structurally modified forms of some peptide drugs have shown enhanced pharmacokinetics, improving their oral bioavailability. Here, we discuss a novel glycomimetic approach to modify lysine residues in peptides. In a model system, the ε-amine of Ts-Lys-OMe was reductively alkylated with a glucose derivative to afford a dihydroxylated piperidine in place of the amine. A similar modification was applied to H-KPV-NH2, a tripeptide derived from the α-melanocyte stimulating hormone (α-MSH) reported to have antimicrobial and anti-inflammatory properties. Antimicrobial assays, under a variety of conditions, showed no activity for Ac-KPV-NH2 or the α- or ε-glycoalkylated analogs. Glycoalkylated peptides did, however, show stability toward proteolytic enzymes. [ABSTRACT FROM AUTHOR]

Background: Maize is a staple food in many regions of the world, particularly in Africa and Latin America. However, maize protein is limiting in the indispensable amino acids lysine and tryptophan, making its protein of poor quality.Objective: The main objective of this study was to determine the protein quality of white African cornmeal by determining the metabolic availability (MA) of lysine and tryptophan.Methods: To determine the MA of lysine, 4 amounts of l-lysine (10, 13, 16, and 18 mg · kg-1 · d-1 totaling 28.6%, 37.1%, 45.7%, and 51.4% of the mean lysine requirement of 35 mg · kg-1 · d-1, respectively) were studied in 6 healthy young men in a repeated-measures design. To determine the MA of tryptophan, 4 amounts of l-tryptophan (0.5, 1, 1.5, and 2 mg · kg-1 · d-1 totaling 12.5%, 25.0%, 37.5%, and 50.0% of the mean tryptophan requirement of 4 mg · kg-1 · d-1, respectively) were studied in 7 healthy young men in a repeated-measures design. The MAs of lysine and tryptophan were estimated by comparing the indicator amino acid oxidation (IAAO) response with varying intakes of lysine and tryptophan in cooked white cornmeal compared with the IAAO response to l-lysine and l-tryptophan intakes in the reference protein (crystalline amino acid mixture patterned after egg protein) with the use of the slope ratio method.Results: The MAs of lysine and tryptophan from African cooked white cornmeal were 71% and 80%, respectively.Conclusion: Our study provides a robust estimate of the availability of lysine and tryptophan in African white maize to healthy young men. This estimate provides a basis for postproduction fortification or supplementation of maize-based diets. This trial was registered at www.clinicaltrials.gov as NCT02402179. [ABSTRACT FROM AUTHOR]

Introduction Pyridoxine-dependent epilepsy (PDE) is a rare disorder of the lysine metabolism, characterized by a pharmacoresistant epileptic encephalopathy that usually begins in the neonatal period. However, its phenotypic spectrum is wide and not limited to seizures. We report a new case of PDE who developed hydrocephalus, along with an exhaustive review of the literature. Case report Our patient presented with seizures at 13 h of life. Antiepileptic drugs, vitamins and cofactors were required to achieve seizure control. Laboratory tests were congruent with PDE. She remained seizure-free until age five months, when seizures reappeared in the context of increasing head size and irritability. A cranial ultrasound showed hydrocephalus, for which she underwent ventriculoperitoneal shunting. Discussion Seven other patients with same features have been previously reported. Seizure onset occurred within the first 7 days in all patients. Most of the children developed hydrocephalus at 6–7 months of age. In 4 out of 7 a genetic mutation was identified, despite the accurate etiology of hydrocephalus was unknown in most of them. The case we report behaved similarly to the others previously described. We postulate that the pathogenesis of this complication could be related to the high expression of antiquitin in choroid plexus epithelium, where the cerebrospinal fluid is produced. Conclusions patients with PDE should be closely monitored, since they may present severe complications. We highlight the development of hydrocephalus, an uncommon but potentially life-threatening problem reported in 8 patients up to present time. [ABSTRACT FROM AUTHOR]

Pyridoxine-dependent epilepsy (PDE) is a rare disease characterized by mutations in the lysine degradation gene ALDH7A1 leading to recurrent neonatal seizures, which are uniquely alleviated by high doses of pyridoxine or pyridoxal 59-phosphate (vitamin B6 vitamers). Despite treatment, neurodevelopmental disabilities are still observed in most PDE patients underlining the need for adjunct therapies. Over 60 years after the initial description of PDE, we report the first animal model for this disease: an aldh7a1-null zebrafish (Danio rerio) displaying deficient lysine metabolism and spontaneous and recurrent seizures in the larval stage (10 days postfertilization). Epileptiform electrographic activity was observed uniquely in mutants as a series of population bursts in tectal recordings. Remarkably, as is the case in human PDE, the seizures show an almost immediate sensitivity to pyridoxine and pyridoxal 59-phosphate, with a resulting extension of the life span. Lysine supplementation aggravates the phenotype, inducing earlier seizure onset and death. By using mass spectrometry techniques, we further explored the metabolic effect of aldh7a1 knockout. Impaired lysine degradation with accumulation of PDE biomarkers, B6 deficiency, and low g-aminobutyric acid levels were observed in the aldh7a12/2 larvae, which may play a significant role in the seizure phenotype and PDE pathogenesis. This novel model provides valuable insights into PDE pathophysiology; further research may offer new opportunities for drug discovery to control seizure activity and improve neurodevelopmental outcomes for PDE. [ABSTRACT FROM AUTHOR]

We hypothesized that hepatic steatosis could be mitigated by the hypolipidemic activity of Schisandra chinensis berry ethanol extract (SCE) via the inhibition of histone acetyltransferase (HAT) activity. HepG2 cells treated with oleic acid (OA) in the presence of SCE exhibited reduced OA-induced lipid accumulation, which was likely mediated by reductions in SREBP-1c expression. SCE attenuated the acetylation of total lysine and H3K9 that was otherwise increased by OA. Male obese mice fed with either a low-fat diet or Western diet exhibited reduced body and liver weights when supplemented with 1% SCE. The SCE-mediated attenuation of hepatic lipid accumulation was accompanied by a decrease in the expression of lipogenic genes. SCE also attenuated the expression of acetylated lysine and non-acetylated forms of H3K9 acetylation in the livers of these mice. Taken together, these results suggest that SCE has potential for further development as a novel therapeutic agent for the prevention of steatosis. [ABSTRACT FROM AUTHOR]

Background Chronic ethanol (EtOH) consumption is a major cause of liver disease worldwide. Oxidative stress is a known consequence of EtOH metabolism and is thought to contribute significantly to alcoholic liver disease (ALD). Therefore, elucidating pathways leading to sustained oxidative stress and downstream redox imbalances may reveal how EtOH consumption leads to ALD. Recent studies suggest that EtOH metabolism impacts mitochondrial antioxidant processes through a number of proteomic alterations, including hyperacetylation of key antioxidant proteins. Methods To elucidate mechanisms of EtOH-induced hepatic oxidative stress, we investigate a role for protein hyperacetylation in modulating mitochondrial superoxide dismutase (SOD2) structure and function in a 6-week Lieber-DeCarli murine model of EtOH consumption. Our experimental approach includes immunoblotting immunohistochemistry (IHC), activity assays, mass spectrometry, and in silico modeling. Results We found that EtOH metabolism significantly increased the acetylation of SOD2 at 2 functionally relevant lysine sites, K68 and K122, resulting in a 40% decrease in enzyme activity while overall SOD2 abundance was unchanged. In vitro studies also reveal which lysine residues are more susceptible to acetylation. IHC analysis demonstrates that SOD2 hyperacetylation occurs near zone 3 within the liver, which is the main EtOH-metabolizing region of the liver. Conclusions Overall, the findings presented in this study support a role for EtOH-induced lysine acetylation as an adverse posttranslational modification within the mitochondria that directly impacts SOD2 charge state and activity. Last, the data presented here indicate that protein hyperacetylation may be a major factor contributing to an imbalance in hepatic redox homeostasis due to chronic EtOH metabolism. [ABSTRACT FROM AUTHOR]

The level of the essential amino acid lysine is of concern in trout feed. The objective of this study was to investigate the response of different families of fish to lysine-deficient ( LD) versus lysine-adequate ( LA) soy protein-containing diets. For each treatment combination, there were five replicates. As expected, feed efficiency ( p < .0001) and thermal growth coefficient ( TGC, p < .0001) were improved in fish fed the LA compared to the LD diet. Hepatosomatic index ( HSI, p < .01) and whole-body lipid content ( p < .01) were higher for fish consuming the LD compared to the LA diet. There was no effect ( p > .05) of diet on hepatic lysine α-ketoglutarate reductase ( LKR) activity, LKR m RNA abundance or lysine oxidation. There was a family effect on feed efficiency ( p < .0001), TGC ( p < .0001) and condition factor ( p < .05) and there was a trend for differences in oxygen consumption ( p < .07) across families while consuming the LD diet; however, there was no effect on ammonia excretion, HSI, lipid content, efficiency of nitrogen or lysine retention or indices of lysine catabolism. One family, in particular, had more favourable feed efficiency and thermal growth coefficient when fed the LD diet, indicating that it may possess an enhanced genetic potential for performance when consuming LD, soybean meal-containing diets. [ABSTRACT FROM AUTHOR]

Glutaric aciduria type I (GA-I) is a rare organic aciduria caused by the autosomal recessive inherited deficiency of glutaryl-CoA dehydrogenase (GCDH). GCDH deficiency leads to disruption of l -lysine degradation with characteristic accumulation of glutarylcarnitine and neurotoxic glutaric acid (GA), glutaryl-CoA, 3-hydroxyglutaric acid (3-OHGA). DHTKD1 acts upstream of GCDH, and its deficiency leads to none or often mild clinical phenotype in humans, 2-aminoadipic 2-oxoadipic aciduria. We hypothesized that inhibition of DHTKD1 may prevent the accumulation of neurotoxic dicarboxylic metabolites suggesting DHTKD1 inhibition as a possible treatment strategy for GA-I. In order to validate this hypothesis we took advantage of an existing GA-I ( Gcdh −/− ) mouse model and established a Dhtkd1 deficient mouse model. Both models reproduced the biochemical and clinical phenotype observed in patients. Under challenging conditions of a high lysine diet, only Gcdh −/− mice but not Dhtkd1 −/− mice developed clinical symptoms such as lethargic behaviour and weight loss. However, the genetic Dhtkd1 inhibition in Dhtkd1 −/− /Gcdh −/− mice could not rescue the GA-I phenotype. Biochemical results confirm this finding with double knockout mice showing similar metabolite accumulations as Gcdh −/− mice with high GA in brain and liver. This suggests that DHTKD1 inhibition alone is not sufficient to treat GA-I, but instead a more complex strategy is needed. Our data highlights the many unresolved questions within the l -lysine degradation pathway and provides evidence for a so far unknown mechanism leading to glutaryl-CoA. [ABSTRACT FROM AUTHOR]

Lysine is considered to be the first essential amino acid in rice. An elite H igh- F ree- L ysine transgenic line HFL1 was previously produced by metabolic engineering to regulate lysine metabolism. In this study, a 90-day toxicology experiment was undertaken to investigate the potential health effect of feeding different doses of HFL1 rice to Sprague-Dawley rats. During the trial, body weight gain, food consumption and food efficiency were recorded, and no adverse effect was observed in rats fed transgenic (T) rice diets compared with non-transgenic (N) or control diets. At both midterm and final assessments, hematological parameters and serum chemistry were measured, and organ weights and histopathology were examined at the end of the trial. There was no diet-related difference in most hematological or serum chemistry parameters or organ weights between rats fed the T diets and those fed the N or control diets. Some parameters were found to differ between T groups and their corresponding N and/or control groups, but no adverse histological effect was observed. Taken together, the data from the current trial demonstrates that high lysine transgenic rice led to no adverse effect in Sprague-Dawley rats given a diet containing up to 70% HFL1 rice in 90 days. [ABSTRACT FROM AUTHOR]

Three experiments were conducted separately to estimate the digestible Lys (dig. Lys) requirements of Cobb × Cobb 500 male broilers using different statistical models. For each experiment, 1,200 chicks were housed in 48 floor pens in a completely randomized design with 6 treatments and 8 replicates. Broilers were fed diets with increasing dig. Lys levels from 1 to 12 d (Exp. 1), from 12 to 28 d (Exp. 2), and 28 to 42 d (Exp. 3). Increasing dig. Lys levels were equally spaced from 0.97 to 1.37% in Exp. 1, 0.77 to 1.17% in Exp. 2, and 0.68 to 1.07% in Exp. 3. The lowest dig. Lys diets were not supplemented with L-Lysine and all other essential AA met or exceeded recommendations. In Exp. 3, six birds per pen were randomly selected from each replication to evaluate carcass and breast yields. Digestible Lys requirements were estimated by quadratic polynomial (QP), linear broken-line (LBL), quadratic broken-line (QBL), and exponential asymptotic (EA) models. Overall, dig. Lys requirements varied among response variables and statistical models. Increasing dietary dig. Lys had a positive effect on BW, carcass and breast yields. Levels of dig. Lys that optimized performance using QP, LBL, QBL, and EA models were 1.207, 1.036, 1.113, and 1.204% for BWG and 1.190, 1.027, 1.100, and 1.172% for FCR in Exp. 1; 1.019, 0.853, 0.944; 1.025% for BWG and 1.050, 0.879, 1.032, and 1.167% for FCR in Exp. 2; and 0.960, 0.835, 0.933, and 1.077% for BWG, 0.981, 0.857, 0.963, and 1.146% for FCR in Exp. 3. The QP, LBL, QBL, and EA also estimated dig. Lys requirements as 0.941, 0.846, 0.925, and 1.070% for breast meat yield in Exp. 3. In conclusion, Lys requirements vary greatly according to the statistical analysis utilized; therefore, the origin of requirement estimation must be taken into account in order to allow adequate comparisons between references. [ABSTRACT FROM AUTHOR]

Proper oocyte development is crucial for female fertility and requires timely and accurate control of gene expression. K (lysine) acetyltransferase 8 (KAT8), an important component of the X chromosome dosage compensation system in Drosophila, regulates gene activity by acetylating histone H4 preferentially at lysine 16. To explore the function of KAT8 during mouse oocyte development, we crossed Kat8flox/flox mice with Gdf9-Cre mice to specifically delete Kat8 in oocytes. Oocyte Kat8 deletion resulted in female infertility, with follicle development failure in the secondary and preantral follicle stages. RNA-seq analysis revealed that Kat8 deficiency in oocytes results in significant downregulation of antioxidant genes, with a consequent increase in reactive oxygen species. Intraperitoneal injection of the antioxidant N-acetylcysteine rescued defective follicle and oocyte development resulting from Kat8 deficiency. Chromatin immunoprecipitation assays indicated that KAT8 regulates antioxidant gene expression by direct binding to promoter regions. Taken together, our findings demonstrate that KAT8 is essential for female fertility by regulating antioxidant gene expression and identify KAT8 as the first histone acetyltransferase with an essential function in oogenesis. [ABSTRACT FROM AUTHOR]

Secretion of high molecular weight (HMW) adiponectin is dependent on post-translational modification (PTM) of conserved lysines in the collagenous domain. The present study aims to characterize the enzymes responsible for the PTM of conserved lysines which leads to HMW adiponectin secretion, and to define its significance in relation to obesity. Collagen beta (1-O) galactosyltransferase 1 (GLT25D1) was knocked down in HEK cells modified for the stable expression of adiponectin (adiponectin expressing human embryonic kidney cells, Adipo-HEK) as well as in Simpson Golabi-Behmel-Syndrome (SGBS) adipocytes. Knockdown of GLT25D1 caused a significant decrease in HMW adiponectin in Adipo-HEK cells with no change in total adiponectin. Knockdown in the SGBS cells caused an increase in lipid accumulation yet inhibited adipogenesis. Co-immunoprecipitation with adiponectin and mass spectrometry showed that adiponectin formed a protein complex with lysyl hydroxylase 3 (LH3) and GLT25D1. Transient overexpression of GLT25D1 showed that the intracellular retention of LH3 was dependent on GLT25D1. To determine whether changes in GLT25D1 were significant in obesity, mice were fed a standard chow or high-fat diet (HFD) for 5 weeks. GLT25D1 was significantly decreased in mice fed HFD which coincided with a decrease in HMW adiponectin. We conclude that GLT25D1 regulates HMW adiponectin secretion and lipid accumulation, consistent with changes in mice after high-fat feeding. These results suggest a novel function of GLT25D1 leading to decreased HMW adiponectin secretion in early obesity. [ABSTRACT FROM AUTHOR]