Inosine Research Articles

Quercetin ameliorates chicken quality by activating the PI3K/PKB/AMPK signaling pathway in broilers.

This study was conducted to investigate the effects and mechanism of quercetin on chicken quality in broilers. We selected 480 AA broilers (1 day old) and randomly allotted those to four treatments (negative control and 0.2, 0.4, or 0.6 g of quercetin per kg of diet) for 42 days. Compared with the control group, the supplementation with 0.4 g of quercetin significantly increased the pH45min and L * value of the thigh muscle and decreased the shearing force of the thigh muscle and breast muscle and drip loss of the thigh muscle (P < 0.05). The supplementation with 0.6 g/kg of quercetin significantly increased the pH45min and L * value of the thigh muscle, and pH45min of breast muscle and decreased the drip loss of the thigh muscle (P < 0.05). Sensory scores of meat color, tenderness, and juiciness also were improved with increasing quercetin concentration (P < 0.05). The inosinic acid (IMP) content of the breast and thigh muscles of broilers was significantly increased by supplementation with 0.6 g/kg of quercetin (P < 0.05). Supplementation with 0.2, 0.4, and 0.6 g of quercetin significantly reduced mRNA expression of L-FABP (P < 0.05, P < 0.05, and P < 0.05); supplementation with 0.4 and 0.6 g/kg of quercetin significantly increased mRNA expression of PKB and AMPKα1 (P < 0.05 and P < 0.05); supplementation with 0.6 g/kg of quercetin in the diet significantly reduced mRNA expression of SREBP1 and HMGR (P < 0.05 and P < 0.05) and significantly increased mRNA expression of CPT1 and PPARγ (P < 0.05 and P < 0.05); and supplementation with 0.2, 0.4, and 0.6 g/kg of quercetin significantly increased mRNA expression of PI3K, LPL, and Apo A1 and significantly reduced mRNA expression of ACC and FATP1 in the breast muscle of broilers (P > 0.05). PI3k, PKB, AMPK, SREBP1, and L-FABP were significantly and positively correlated with pH45min (P < 0.05); PPARγ was significantly and positively correlated with shear force (P < 0.05); CPT1 was significantly and positively correlated with the L * value (P < 0.05); and HMGR was significantly and positively correlated with drip loss (P < 0.05). In conclusion, quercetin improved the meat quality, protecting it against lipid oxidation and deposition by regulating the PI3K/PKB/AMPKα1 signaling pathway in the breast muscle of broilers.

Sappanone A Aggrandises Ionising Radiation-induced Damage in Oral Epithelial Cells.

To analyse the role played by Sappanone A, a bioactive ingredient isolated from the heartwood of Caesalpinia sappan, in the regulation of oral epithelial cell viability under radiation. Cell viability of human oral keratinocytes (HOKs) and mouse salivary gland cells under ionising radiation was analysed. Expression of Ki67 was measured by immunohistochemical staining. Fragmentation of deoxyribonucleic acid (DNA) was measured by comet assay. Cell death was analysed using trypan blue exclusion assay. Cell viability was measured using a Cell Counting Kit 8 (CCK8; Abcam, Cambridge, UK) assay. Sappanone A decreased cell viability of HOK cells and mouse salivary gland cells under ionising radiation. In addition, Sappanone A enhanced radiation-induced genomic DNA fragmentation, accompanied by impaired homologous recombination and non-homologous end joining DNA repair. Mechanistic evaluation revealed that Sappanone A counteracted radiation-induced inosine monophosphate dehydrogenase 2 (IMPDH2) activation, and that this effect could be abolished by reconstituted expression of a Sappanone A-binding defective IMPDH2 mutant. The present study highlights a novel role played by Sappanone A in the modulation of radiosensitivity of oral epithelial cells.

The pursuit of new alternative ways to eradicate Helicobacter pylori continues: Detailed characterization of interactions in the adenylosuccinate synthetase active site

Purine nucleotide synthesis is realised only through the salvage pathway in pathogenic bacterium Helicobacter pylori. Therefore, the enzymes of this pathway, among them also the adenylosuccinate synthetase (AdSS), present potential new drug targets. This paper describes characterization of His6-tagged AdSS from H. pylori. Thorough analysis of 3D-structures of fully ligated AdSS (in a complex with guanosine diphosphate, 6-phosphoryl-inosine monophosphate, hadacidin and Mg2+) and AdSS in a complex with inosine monophosphate (IMP) only, enabled identification of active site interactions crucial for ligand binding and enzyme activity. Combination of experimental and molecular dynamics (MD) simulations data, particularly emphasized the importance of hydrogen bond Arg135-IMP for enzyme dimerization and active site formation. The synergistic effect of substrates (IMP and guanosine triphosphate) binding was suggested by MD simulations. Several flexible elements of the structure (loops) are stabilized by the presence of IMP alone, however loops comprising residues 287–293 and 40–44 occupy different positions in two solved H. pylori AdSS structures. MD simulations discovered the hydrogen bond network that stabilizes the closed conformation of the residues 40–50 loop, only in the presence of IMP. Presented findings provide a solid basis for the design of new AdSS inhibitors as potential drugs against H. pylori.

IMPDH inhibition activates TLR-VCAM1 pathway and suppresses the development of MLL-fusion leukemia.

Inosine monophosphate dehydrogenase (IMPDH) is a rate-limiting enzyme in de novo guanine nucleotide synthesis pathway. Although IMPDH inhibitors are widely used as effective immunosuppressants, their antitumor effects have not been proven in the clinical setting. Here, we found that acute myeloid leukemias (AMLs) with MLL-fusions are susceptible to IMPDH inhibitors invitro. We also showed that alternate-day administration of IMPDH inhibitors suppressed the development of MLL-AF9-driven AML invivo without having a devastating effect on immune function. Mechanistically, IMPDH inhibition induced overactivation of Toll-like receptor (TLR)-TRAF6-NF-κB signaling and upregulation of an adhesion molecule VCAM1, which contribute to the antileukemia effect of IMPDH inhibitors. Consequently, combined treatment with IMPDH inhibitors and the TLR1/2 agonist effectively inhibited the development of MLL-fusion AML. These findings provide a rational basis for clinical testing of IMPDH inhibitors against MLL-fusion AMLs and potentially other aggressive tumors with active TLR signaling.

Repurposing immunosuppressants for antileukemia therapy.

Drug repurposing, the strategy to identify new therapeutic use for clinically approved drugs has attracted much attention in recent years. This strategy offers various advantages over traditional approaches to develop new drugs, including shorter development timelines, low cost, and reduced risk of failure. In this issue of EMBO Molecular Medicine, Liu etal show that inosine monophosphate dehydrogenase (IMPDH) inhibitors, the well-known immunosuppressants have a potent therapeutic effect on the aggressive blood cancer, acute myeloid leukemia with MLL rearrangements. Intriguingly, the antileukemia effect of IMPDH inhibitors is mediated, at least in part through the overactivation of TLR signaling and Vcam1 upregulation. The robust antileukemia effect of IMPDH inhibitors, both invitro and invivo, together with their mechanistic findings provides a rational basis for repurposing IMPDH inhibitors for antileukemia therapy.

Integrative Analysis of Transcriptomic and Metabolomic Data for Identification of Pathways Related to Matrine-Induced Hepatotoxicity.

Matrine (MT) is a major bioactive compound extracted from Sophorae tonkinensis. However, the clinical application of MT is relatively restricted due to its potentially toxic effects, especially hepatotoxicity. Although MT-induced liver injury has been reported, little is known about the underlying molecular mechanisms. In this study, transcriptomics and metabolomics were applied to investigate the hepatotoxicity of MT in mice. The results indicated that liver injury occurred when the administration of MT (30 or 60 mg/kg, i.g) lasted for 2 weeks, including dramatically increased alanine aminotransferase (ALT), aspartate aminotransferase (AST), etc. The metabolomic results revealed that steroid biosynthesis, purine metabolism, glutathione metabolism, and pyruvate metabolism were involved in the occurrence and development of MT-induced hepatotoxicity. Further, the transcriptomic data indicated that the downregulation of NSDHL with CYP51, FDFT1, and DHCR7, involved in steroid biosynthesis, resulted in a lower level of cholic acid. Besides, Gstps and Nat8f1 were related to the disorder of glutathione metabolism, and HMGCS1 could be treated as the marker gene of the development of MT-induced hepatotoxicity. In addition, other metabolites, such as taurine, flavin mononucleotide (FMN), and inosine monophosphate (IMP), also made a contribution to the boosting of MT-induced hepatotoxicity. In this work, our results provide clues for the mechanism investigation of MT-induced hepatotoxicity, and several biomarkers (metabolites and genes) closely related to the liver injury caused by MT are also provided. Meanwhile, new insights into the understanding of the development of MT-induced hepatotoxicity or other monomer-induced hepatotoxicity were also provided.

Biochemical metabolomic profiling of the Crown-of-Thorns Starfish (Acanthaster): New insight into its biology for improved pest management

The Crown-of-Thorns Starfish (COTS), Acanthaster species, is a voracious coral predator that destroys coral reefs when in outbreak status. The baseline metabolite and lipid biomolecules of 10 COTS tissues, including eggs from gravid females, were investigated in this study to provide insight into their biology and identify avenues for control. Targeted and untargeted metabolite- and lipidomics-based mass spectrometry approaches were used to obtain tissue-specific metabolite and lipid profiles. Across all COTS tissues, 410 metabolites and 367 lipids were identified. Most abundant were amino acids and peptides (18.7%) and wax esters (17%). There were 262 metabolites and 192 lipids identified in COTS eggs. Wax esters were more abundant in the eggs (30%) followed by triacylglycerols (TG), amino acids, and peptides. The diversity of asterosaponins in eggs (34) was higher than in tissues (2). Several asterosaponins known to modulate sperm acrosome reaction were putatively identified, including glycoside B, asterosaponin-4 (Co-Aris III), and regularoside B (asterosaponin A). The saponins saponin A, thornasteroside A, hillaside B, and non-saponins dictyol J and axinellamine B which have been shown to possess defensive properties, were found in abundance in gonads, skin, and radial nerve tissues. Inosine and 2-hexyldecanoic acid are the most abundant metabolites in tissues and eggs. As a secondary metabolite of purine degradation, inosine plays an important role in purine biosynthesis, while 2-hexyldecanoic acid is known to suppress side-chain crystallization during the synthesis of amphiphilic macromolecules (i.e., phospholipids). These significant spatial changes in metabolite, lipid, and asterosaponin profiles enabled unique insights into key biological tissue-specific processes that could be manipulated to better control COTS populations. Our findings highlight COTS as a novel source of molecules with therapeutic and cosmetic properties (ceramides, sphingolipids, carnosine, and inosine). These outcomes will be highly relevant for the development of strategies for COTS management including chemotaxis-based biocontrol and exploitation of COTS carcasses for the extraction of commercial molecules.

Enhancements in flavor substances, mouthfeel characteristics and collagen synthesis in the muscle of sub-adult grass carp (Ctenopharyngodon Idella): Application of a dietary lysine nutrition strategy

The growth performance, flavor substances, mouthfeel characteristics and collagen synthesis in the muscle of sub-adult grass carp (659.07 ± 0.74 g) were investigated after 60-day feeding with graded dietary levels of lysine (6.0–17.0 g/kg diet). The results showed that optimal dietary lysine levels boosted the growth of grass carp. Proper dietary lysine levels improved muscle inosine monophosphate, free amino acids, unsaturated fatty acid content, water holding capacity, pH and shear force (hardness). The diets also decreased lactate content, and enhanced collagen content by increasing transcription, translation and post-translational modifications of type I collagen, probably via activating TGF-β1/Smads and PI3K/Akt/p70S6k/la ribonucleoprotein domain family member 6 (LARP6) signaling; this enhanced prolyl 4-hydroxylase (P4H) and lysyl hydroxylase (LOX) content, thereby improving the flavor and mouthfeel of muscle. In summary, this research indicated that dietary lysine could lead to the enhancement of muscle flavor substances, mouthfeel characteristics and type I collagen synthesis in sub-adult grass carp. Based on the PWG and shear force, the dietary requirements of lysine for sub-adult grass carp are 13.43 and 12.96 g/kg, respectively.

Bio-Fermented Malic Acid Facilitates the Production of High-Quality Chicken via Enhancing Muscle Antioxidant Capacity of Broilers.

Malic acid, an intermediate of the tricarboxylic acid (TCA) cycle, is a promising acidifier with strong antioxidant capacity. This study aimed to evaluate the effects of bio-fermented malic acid (BFMA) on promoting the body health, performance and meat quality of broilers. A total of 288 one-day-old Arbor Acres male broiler chicks were randomly divided into four treatments with six replicates in each. Every replicate had 12 chicks. Four experimental diets contained 0, 4, 8, and 12 g/kg BFMA, respectively. During the 42-day trial, mortality was recorded daily, feed intake and body weight of each replicate being recorded every week. Blood samples were collected on days 21 and 42 for chemical analysis. After slaughter at the age of 42 days, the carcass traits and meat quality of the broilers were measured, breast muscle samples were collected for the determination of antioxidant capacity, and cecal digesta were pretreated for microbiota analysis. Dietary BFMA significantly increased feed intake and daily gain, and decreased feed conversion ratio and death and culling ratio of the broilers at the earlier stage. The water-holding capacity of breast muscle indicated by the indexes of dripping loss and cooking loss was significantly increased by BFMA, especially at the addition level of 8 g/kg. Dietary BFMA significantly decreased the activity of superoxide dismutase and contents of immunoglobulin A and glutathione, and increased contents of immunoglobulin G and M in serum of the broilers. The contents of glutathione, inosinic acid, and total antioxidant capacity and the activities of glutathione-Px and superoxide dismutase were significantly increased by dietary BFMA, with the level of 8 g/kg best. The diversity of cecal microbiota of broilers was obviously altered by BFMA. In conclusion, as one of several acidifiers, addition of BFMA in diets could improve the performance and body health of broilers, probably by reinforcing immunity and perfecting cecal microbiota structure. As one of the intermediates of the TCA cycle, BFMA increases the water-holding capacity of breast muscle of broilers, probably through reducing lactate accumulates and enhancing antioxidant capacity.

Highly-sensitive electrochemiluminescence biosensor for detection of inosine monophosphate in meat based on graphdiyne/AuNPs/luminol nanocomposites

Inosine monophosphate (IMP), as a critical umami substance, is one of the most important indicators for evaluating the quality of meat products. Here, a sensitive electrochemiluminescence (ECL) biosensor based on graphdiyne (GDY)/AuNPs/luminol nanocomposites was constructed to detect IMP. The GDY/AuNPs/luminol nanocomposites were synthesized by using simple one-pot method. GDY utilized its 2D framework to disperse and fix gold nanoparticles, which inhibited the agglomeration of gold nanoparticles and greatly improved its stability and catalytic properties. Importantly, GDY/AuNPs/luminol nanocomposites showed excellent catalytic ability and superior ECL activity towards luminol-H2O2 systems due to the synergistic effect of GDY and AuNPs. Under optimal conditions, the prepared biosensor exhibited a wide linear range from 0.01 g/L to 20 g/L, a satisfactory limit detection of 0.0013 g/L, as well as an excellent specificity. Moreover, we carried out the precise analysis of IMP in actual meat samples with acceptable results compared to the liquid chromatography. We believe that this work could offer an efficient ECL platform for accurate and reliable report of IMP levels, which is significant for maintaining food quality and safety.

Development of Flavor and Taste Components of Sous-Vide-Cooked Nile Tilapia (Oreochromis niloticus) Fillet as Affected by Various Conditions.

This study aims to shed light on the association between non-volatile and volatile compounds related to flavor/taste characteristics as well as sensory acceptability of Nile tilapia fillet (Oreochromis niloticus) cooked by various sous-vide (SV) conditions (50-60 ℃, 30-60 min), with fish cooked with boiling water used as control. Higher temperatures and longer processing times of SV cooking led to greater protein and lipid oxidation as indicated by the increase in total sulfhydryl (-SH), carbonyl, free fatty acid (FFA) contents as well as peroxide values (PV) and thiobarbituric acid reactive substance (TBARS) values. The differences in flavor/taste components including adenosine triphosphate (ATP)-related compounds, free amino acids (FAAs) and volatiles were also obtained, which directly affect sensory acceptability as evaluated by using the hedonic scale. Based on principal component analysis (PCA) results, the acceptability score was strongly correlated with inosine monophosphate (IMP) and acetoin, which seem to be the most crucial flavor enhancers for cooked tilapia. Among all samples, tilapia processed at 60 °C for 45 and 60 min, which contained significantly higher IMP and acetoin (p &lt; 0.05) than others, had significantly higher flavor-liking and overall-liking scores, with a more than 7.5 meaning for high acceptability (p &lt; 0.05), indicating the optimal SV conditions for tilapia fillet. Overall, the present finding indicated that the SV-cooking technique, at the optimal conditions, can improve the meat quality of cooked fish, in terms of flavor/taste characteristics, compared with traditional cooking (control).

A new limit for blood metabolite analysis using 1H NMR spectroscopy

Human blood is the most widely used biospecimen in the clinic and the metabolomics field. While both mass spectrometry and NMR spectroscopy are the two premier analytical platforms in the metabolomics field, NMR exhibits several unsurpassed characteristics for blood metabolite analysis, the most important of which are its ability to identify unknown metabolites and its quantitative nature. However, the relatively small number of metabolites accessible by NMR has restricted the scope of its applications. Enhancing the limit of identified metabolites in blood will therefore greatly impact NMR-based metabolomics. Continuing our efforts to address this major issue, our current study describes the identification of 12 metabolites, which expands the number of quantifiable blood metabolites by ∼15%. These results, in combination with our earlier efforts, now provide access to nearly 90 metabolites, which is the highest to date for a simple 1D 1H NMR experiment that is widely used in the metabolomics field. Metabolites were identified based on the comprehensive investigation of human blood and plasma using 1D/2D NMR techniques. The newly identified metabolites were validated based on chemical shift databases, spectra of authentic compounds obtained under conditions identical to blood/plasma, and, finally, spiking experiments using authentic compounds. Considering the high reproducibility of NMR and the sensitivity of chemical shifts to altered sample conditions, experimental protocols and peak annotations are provided for the newly identified metabolites, which serve as a template for identification of blood metabolites for routine applications. Separately, the identified metabolites were evaluated for their sensitivity to preanalytical conditions. The results reveal that among the newly identified metabolites, inosine monophosphate (IMP) and nicotinamide are associated with labile coenzymes and their levels are sensitive to preanalytical conditions. The study demonstrates the expansion of quantifiable blood metabolites using NMR to a new height and is expected to greatly impact blood metabolomics.

Untargeted Metabolomics on Dried Blood Spots of Patients with Sickle Cell Disease Treated with the Pyruvate Kinase Activator Mitapivat

Background Sickle cell disease (SCD) is one of the most common inherited red blood cell (RBC) disorders. The disease is characterized by polymerization of sickle hemoglobin (HbS) upon deoxygenation resulting in, among other things, chronic life-threatening complications. The pathophysiology of SCD is multifactorial and highly complex. Novel anti-sickling agents under development for SCD include oral, small molecule pyruvate kinase activators such as mitapivat (AG-348). Mitapivat could reduce HbS polymerization by decreasing the level of the glycolytic intermediate metabolite 2,3-diphosphoglycerate (2,3-DPG), thereby increasing the oxygen affinity of hemoglobin, and the level of adenosine triphosphate (ATP) to increase cellular energy. We investigated, as an exploratory outcome, changes in untargeted metabolomics on dried blood spots (DBS) of patients with SCD treated with mitapivat in the 8-week Dose Finding Period of an investigator-initiated, open label, phase 2 study (EudraCT 2019-003438-18, ESTIMATE study). Methods Untargeted metabolomics was performed by direct-infusion high-resolution mass spectrometry on DBS of patients ≥16 years with SCD (HbSS, HbS/β0 or HbS/β+-thalassemia) collected at baseline and at completion of the 8-week Dose Finding Period. In this period, patients received initial dosing of 20 mg mitapivat twice daily with a maximum of two sequential dose escalations to 50 mg and 100 mg twice daily every two weeks depending on safety. DBS samples obtained from healthy adults were used to calculate Z-scores. Data analyses were conducted in MetaboAnalyst (v5.0) without data filtering or normalization. Distinct metabolic profiles between baseline samples of patients with SCD and healthy controls were identified by multivariate principal component analysis and partial least square discriminant analysis, as well as independent two-sample t-tests with equal group variance. False Discovery Rate (FDR) adjusted p-values were used to correct for multiple testing. A significance level of 0.05 was applied. Distinctive increased or decreased metabolites were also analyzed at treatment week 8 and compared to baseline in the cohort of patients with SCD. Additional analyses were performed in Graphpad Prism (v9.3.0) including paired two-sample t-tests for individual Z-scores of features. Results In total, 1907 unique metabolite features were identified in DBS of 9 patients with SCD (n=7 HbSS, n=1 HbS/β0, n=1 HbS/β+-thalassemia; median age 22 years (range 16-59 years); 6/9 (67%) female) and 29 healthy controls (median age 38 years (range 25-65 years); 21/29 (72%) female). One HbSS patient and one healthy control were determined as outliers and excluded from final analysis. A total of 55 metabolites were significantly different between patient samples at baseline and healthy control samples. The top 35 are shown in a heatmap (Figure 1) and include increased acyl carnitines, (derivatives of) polyamines, purines and pyrimidines, and decreased carbohydrates and benzenoids. Patient samples showed an increase in 8/55 metabolites, of which 5 towards normalization, after 8-week treatment with mitapivat (unadjusted p-value <0.05), and no significant decreases (Table 1). In patients a significant increase was seen in 2/1907 unique metabolite features after 8 weeks of treatment with mitapivat compared to baseline: butenylcarnitine, which is an acyl carnitine, and inosinic acid, or inosine-5-monophosphate (5'-IMP), which is a purine nucleotide (FDR-adjusted p-value <0.05; data not shown). Conclusion Patients with SCD showed a distinct metabolic profile compared to healthy controls. The distinctions were determined by metabolites produced by RBC-related pathways including the glycolytic and purinergic signaling pathway that mediate hypoxic metabolic reprogramming, carnitine derivatives, involved in turnover and repair of the RBC membrane, and polyamines, that probably stabilize the RBC membrane (as reported from other hereditary hemolytic anemias). Moreover, after 8 weeks of treatment with mitapivat showed, again, changes in an acyl carnitine and purine nucleotide compared to baseline. We conclude that the distinct metabolic profile from healthy controls is a promising starting point to further unravel the underlying pathophysiology of SCD and to characterize the endogenous and exogenous effects of pyruvate kinase activators and other novel therapies. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

DDDR-21. REGULATORY REDUCTASE SUBUNIT RRM2 AND DEHYDROGENASE IMPDH2 INTERACT IN GLIOBLASTOMA IN A TMZ-DEPENDENT MANNER

Abstract Glioblastoma (GBM) is an aggressive primary brain tumor characterized by poor prognostic outcomes. Nearly all GBM tumors recur, due to cellular resistance against chemotherapies, including temozolomide (TMZ), which develops during active treatment. To investigate these adaptive mechanisms, our lab conducted a single-cell RNA sequencing analysis utilizing an in vivo patient-derived xenograft (PDX) model of GBM, prior to, during, and post TMZ-based therapy. Our data revealed 149 genes to be uniquely expressed in the during-TMZ condition (p &amp;lt; 0.0001), including two regulatory enzymes involved in purine metabolism: the Ribonucleotide Reductase (RNR) Regulatory Subunit 2, RRM2, and inosine monophosphate dehydrogenase 2, IMPDH2. Previous work in this lab has independently established both RRM2 and IMPDH2 as significant drivers of TMZ-resistance in GBM, through their respective abilities to alter tumor metabolism during therapy. Network analysis of genetic pathways enriched during TMZ therapy revealed a previously unidentified interaction between IMPDH2 and the RRM1 subunit of the RNR enzyme. Given these data, we aimed to determine if there was also an interaction between IMPDH2 and RRM2 in GBM. Immunocyto- and histochemistry of GBM-PDX primarily demonstrated significant co-localization between RRM2 and IMPDH2 during TMZ therapy. Immunoprecipitation (IP) and reverse-IP analyses were subsequently conducted, and revealed a previously unreported molecular interaction between the two proteins in GBM lines, which increased in a TMZ-dependent manner. These results were not corroborated in neural stem cell lines. Additionally, immunoblot analyses revealed that in RRM2-knockdown GBM-PDX, IMPDH2 protein expression is decreased compared to controls. We hypothesize the dynamic interaction of RRM2 and IMPDH2 to enhance the metabolic adaptations underlying GBM chemoresistance. The efforts of this study are now focused on investigating the potentially synergistic mechanisms of FDA-approved RRM2 and IMPDH2 inhibitors, previously shown to enhance the efficiency of TMZ. This novel and targetable interaction may present a promising clinical opportunity for GBM therapy.

Evaluation of light-emitting diode colors and intensities on slaughter performance, meat quality and serum antioxidant capacity in caged broilers.

This study was to evaluate the interaction of three different light-emitting diode (LED) light colors (white, green, and blue) and three intensities (5, 10, and 15 lx) on slaughter performance, meat quality and serum antioxidant capacity of broilers raised in three-layer cages. A total of 648 (8-days-old) male broiler chicks (Cobb-500) were randomly assigned in 3×3 factorially arranged treatments: three light colors (specifically, white, blue, and green) and three light intensities (namely, 5, 10, and 15 lx) for 35 days. Each treatment consisted of 6 replicates of 12 chicks. The test lasted for 35 days. The semi-eviscerated weight percentage (SEWP) in 5 lx white was higher than that in 15 lx (p<0.01). The eviscerated weight percentage (EWP) (p<0.05) and water-loss percentage (WLP) (p<0.01) decreased in 10 lx white light than those in green light. Under blue light, the content of hypoxanthine (Hx) in muscle was lower than that under white and green light (p<0.01). The content of malondialdehyde (MDA) in 15 lx blue light was higher than that in 10 lx green light (p<0.05). Light color had an extremely significant effect on thigh muscle percentage, WLP, Hx, and crude protein content (p<0.01). Light intensity had a significant effect on SEWP (p<0.05), EWP (p<0.05), lightness (L*) value (p<0.05), WLP (p<0.01), and the contents of superoxide dismutase (p<0.05), MDA (p<0.01), glutathione peroxidase (p<0.01). Using white LED light with 10 lx light intensity can significantly improve the chicken quality of caged Cobb broilers, improve the content of inosine acid in chicken breast and enhance the antioxidant capacity of the body. We suggest that the broiler farm can use 10 lx white LED light source for lighting in 8 to 42 days.

Metabolomics-Based Analysis of the Major Taste Contributors of Meat by Comparing Differences in Muscle Tissue between Chickens and Common Livestock Species.

The taste of meat is the result of complex chemical reactions. In this study, non-target metabolomics was used to resolve the taste differences in muscle tissue of four major livestock species (chicken, duck, pork, and beef). The electronic tongue was then combined to identify the major taste contributors to meat. The results showed that the metabolism of chicken meat differed from that of duck, pork, and beef. The multivariate statistical analysis showed that the five important metabolites responsible for the differences were all related to taste, including creatinine, hypoxanthine, gamma-aminobutyric acid, L-glutamic acid, and L-aspartic acid. These five key taste contributors acted mainly through the amino acid metabolic pathways. In combination with electronic tongue (e-tongue) analysis, inosine monophosphate was the main contributor of umami. L-Glutamic acid and L-aspartic acid might be important contributors to the umami richness. Creatinine and hypoxanthine contributed more to the bitter aftertaste of meat.

New triazole-substituted triterpene derivatives exhibiting anti-RSV activity: synthesis, biological evaluation, and molecular modeling.

Respiratory syncytial virus (RSV) is a major cause of acute lower respiratory tract infections in infants. Currently, ribavirin, a nucleoside analog containing a 1,2,4-triazole-3-carboxamide moiety, is a first-line drug for its treatment, however, its clinical use has been limited due to its side effects. Here, we designed two new nitroaryl-1,2,3-triazole triterpene derivatives as novel anti-RSV drugs. Their anti-RSV and cytotoxic activity were evaluated in vitro, RSV protein F gene effects by RT-PCR and molecular modeling with inosine monophosphate dehydrogenase (IMPDH) were performed. Compound 8 was the best performing compound, with an EC50 value of 0.053 μM, a TI of 11160.37 and it inhibited hRSV protein F gene expression by approximately 65%. Molecular docking showed a top-ranked solution located in the same region occupied by crystallographic ligands in their complex with IMPDH. The results obtained in this study suggest that compound 8 might be a new anti-RSV candidate.

Potential prognostic markers of retained placenta in dairy cows identified by plasma metabolomics coupled with clinical laboratory indicators

: Background The complex etiopathology of retained placenta (RP) and hazards associated with it has made it crucial for researchers and clinical veterinarians to study pathogenesis, early-warning diagnosis, and treatment. Objectives This study aimed to screen the potential prognostic markers of RP in dairy cows using plasma metabolomics coupled with clinical laboratory indicators. Methods Blood samples were collected from 260 dairy cows at 21, 14, 7, and 0 days before parturition and 7, 14, and 21 days after parturition. Consequently, 10 healthy cows and 10 cows with RP with similar parity, body condition score, and age were included in the study. The changes in clinical laboratory indicators of the enrolled cows from 21 before parturition to 21 days after parturition were assessed. After initial overview of the multivariate statistical data using PCA analysis, the data were subjected to orthogonal partial least-squares discriminant analysis. Results Compared with cows with RP at 7 days before parturition, the levels of endothelin and 6-keto-prostaglandin F1α were increased in healthy cows while the level of estradiol and progesterone decreased. Adenine dinucleotide phosphate, hypoxanthine, guanine dinucleotide phosphate, inosine monophosphate, and L-arginine were revealed as potential prognostic markers of cows with RP at 7 days before parturition involved in the regulation of taste transduction, purine and glutathione metabolism, and autophagy. Conclusions The best period for the early-warning diagnosis of RP in dairy cows is 7 days before parturition, and purine metabolism and autophagy may play a vital role in the occurrence and development of RP in dairy cows.

Metabolomic Study of a Rat Model of Retinal Detachment.

Retinal detachment is a serious ocular disease leading to photoreceptor degeneration and vision loss. However, the mechanism of photoreceptor degeneration remains unclear. The aim of this study was to investigate the altered metabolism pathway and physiological changes after retinal detachment. Eight-week-old male SD rats were fed, and the model of retinal detachment was established by injecting hyaluronic acid into the retinal space. The rats were euthanized 3 days after RD, and the retinal tissues were sectioned for analysis. Untargeted lipid chromatography-mass spectrometry lipidomic was performed to analyze the metabolite changes. A total of 90 significant metabolites (34 in anionic and 56 in cationic models) were detected after retinal detachment. The main pathways were (1) histidine metabolism; (2) phenylalanine, tyrosine, and tryptophan biosynthesis; and (3) glycine, serine, and threonine metabolism. The key genes corresponding to each metabolic pathway were verified from the Gene Expression Omnibus (GEO) database of human retinal samples. The results indicated that the production of histamine by histidine decarboxylase from histidine reduced after RD (p &lt; 0.05). Xanthine, hypoxanthine, guanine, and guanosine decreased after RD (p &lt; 0.05). Decreased xanthine and hypoxanthine may reduce the antioxidant ability. The decreased guanosine could not provide enough sources for inosine monophosphate production. Tyrosine is an important neurotransmitter and was significantly reduced after RD (p &lt; 0.05). Citrate was significantly reduced with the increase of ATP-citrate lyase enzyme (ACLY) (p &lt; 0.05). We inferred that lipid oxidation might increase rather than lipid biogenesis. Thus, this study highlighted the main changes of metabolite and physiological process after RD. The results may provide important information for photoreceptor degeneration.

Targeted deletion of ecto-5′-nucleotidase results in retention of inosine monophosphate content in postmortem muscle of medaka (Oryzias latipes)

Inosine monophosphate (IMP) is an important indicator of meat freshness and contributes to its umami taste. An attractive strategy for enhancing umami is to suppress the IMP-degrading activity and increase the IMP content in the skeletal muscle through genome editing technology using the CRISPR-Cas9 system. However, the molecular mechanisms underlying IMP degradation remain unclear. We cloned two ecto-5′-nucleotidase genes, designated as ecto-5′-nucleotidase-a (nt5ea) and ecto-5′-nucleotidase-b (nt5eb), from medaka (Oryzias latipes), a vertebrate model organism. Expression analysis using embryos showed that nt5ea or nt5eb overexpression remarkably upregulated IMP degradation, and that the IMP-degrading activity was higher in Nt5ea than in Nt5eb. Furthermore, we established frame-shifted or large deletion (lacking nt5ea or nt5eb locus) mutant strains and assayed the effects of gene disruptions on the amount of IMP in skeletal muscle. The nt5ea-deficient medaka showed considerable higher levels of IMP at 48 h postmortem than did the wild-type fish. The nt5eb mutants also exhibited higher IMP contents than that in the wild types, but the increase was less than that in the nt5ea mutants. Our results demonstrated that nt5e is an important regulator of IMP levels in skeletal muscle and that its loss of function was effective in maintaining IMP content.