Structure-based mechanism of riboregulation of the metabolic enzyme SHMT1.

RNA can directly control protein activity in a process called riboregulation; only a few mechanisms of riboregulation have been described in detail, none of which have been characterized on structural grounds. Here, we present a comprehensive structural, functional, and phylogenetic analysis of riboregulation of cytosolic serine hydroxymethyltransferase (SHMT1), the enzyme interconverting serine and glycine in one-carbon metabolism. We have determined the cryoelectron microscopy (cryo-EM) structure of human SHMT1 in its free- and RNA-bound states, and we show that the RNA modulator competes with polyglutamylated folates and acts as an allosteric switch, selectively altering the enzyme's reactivity vs. serine. In addition, we identify the tetrameric assembly and a flap structural motif as key structural elements necessary for binding of RNA to eukaryotic SHMT1. The results presented here suggest that riboregulation may have played a role in evolution of eukaryotic SHMT1 and in compartmentalization of one-carbon metabolism. Our findings provide insights for RNA-based therapeutic strategies targeting this cancer-linked metabolic pathway.

Identification of Anastatica hierochuntica L. Methanolic-Leaf-Extract-Derived Metabolites Exhibiting Xanthine Oxidase Inhibitory Activities: In Vitro and In Silico Approaches.

There is a growing interest in the discovery of novel xanthine oxidase inhibitors for gout prevention and treatment with fewer side effects. This study aimed to identify the xanthine oxidase (XO) inhibitory potential and drug-likeness of the metabolites present in the methanolic leaf extract of Anastatica (A.) hierochuntica L. using in vitro and in silico models. The extract-derived metabolites were identified by liquid-chromatography-quadrupole-time-of-flight-mass-spectrometry (LC-QTOF-MS). Molecular docking predicted the XO inhibitory activity of the identified metabolites and validated the best scored in vitro XO inhibitory activities for experimental verification, as well as predictions of their anticancer, pharmacokinetic, and toxic properties; oral bioavailability; and endocrine disruption using SwissADMET, PASS, ProTox-II, and Endocrine Disruptome web servers. A total of 12 metabolites, with a majority of flavonoids, were identified. Rutin, quercetin, and luteolin flavonoids demonstrated the highest ranked docking scores of -12.39, -11.15, and -10.43, respectively, while the half-maximal inhibitory concentration (IC50) values of these metabolites against XO activity were 11.35 µM, 11.1 µM, and 21.58 µM, respectively. In addition, SwissADMET generated data related to the physicochemical properties and drug-likeness of the metabolites. Similarly, the PASS, ProTox-II, and Endocrine Disruptome prediction models stated the safe and potential use of these natural compounds. However, in vivo studies are necessary to support the development of the prominent and promising therapeutic use of A. hierochuntica methanolic-leaf-extract-derived metabolites as XO inhibitors for the prevention and treatment of hyperuricemic and gout patients. Furthermore, the predicted findings of the present study open a new paradigm for these extract-derived metabolites by revealing novel oncogenic targets for the potential treatment of human malignancies.

Endogenous hydrogen sulfide accelerated trauma-induced heterotopic ossification through the Ca2+/ERK pathway-enhanced aberrant osteogenic activity.

Unveiling of the mechanism involved in the occurrence and development of trauma-induced heterotopic ossification (tHO) is highly demanding due to current ineffective clinical treatment for it. Previous studies proposed that hydrogen sulfide (H2S) was vital for fate determination of stem cells, suggesting a potential role in the regulation of tHO development. In the current study, We found that expression of metabolic enzyme within sulfur conversion pathway was enhanced after tendon injury, leading to H2S accumulation within the tHO region. Increased production of endogenous H2S was shown to promote aberrant osteogenic activity of tendon-derived stem cells (TDSCs), which accelerated tHO formation. The inhibition of metabolic enzyme of H2S production or directly absorption of H2S could abolished osteogenic induction of TDSCs and the formation of tHO. Mechanistically, through RNA sequencing combined with rescue experiments, we demonstrated that activation of Ca2+/ERK pathway was the downstream molecular event of H2S-induced osteogenic commitment of TDSCs and tHO. For treatment strategy exploration, zine oxide nanoparticles (ZnO) as an effective H2S elimination material was validated to ideally halt the tHO formation in this study. Furthermore, in terms of chirality of nanoparticles, D-ZnO or L-ZnO nanoparticles showed superiority over R-ZnO nanoparticles in both clearing of H2S and inhibition of tHO. Our study not only revealed the mechanism of tHO through the endogenous gas signaling event from a new perspective, but also presented a applicable platform for elimination of the inordinate gas production, thus aiding the development of clinical treatment for tHO.

The role of lymphatic endothelial cell metabolism in lymphangiogenesis and disease.

Lymphatic endothelial cells (LECs) line lymphatic vessels, which play an important role in the transport of lymph fluid throughout the human body. An organized lymphatic network develops via a process termed "lymphangiogenesis." During development, LECs respond to growth factor signaling to initiate the formation of a primary lymphatic vascular network. These LECs display a unique metabolic profile, preferring to undergo glycolysis even in the presence of oxygen. In addition to their reliance on glycolysis, LECs utilize other metabolic pathways such as fatty acid ß-oxidation, ketone body oxidation, mitochondrial respiration, and lipid droplet autophagy to support lymphangiogenesis. This review summarizes the current understanding of metabolic regulation of lymphangiogenesis. Moreover, it highlights how LEC metabolism is implicated in various pathological conditions.

Metabolism, Disposition, Excretion, and Potential Transporter Inhibition of 7-16, an Improving 5-HT2A Receptor Antagonist and Inverse Agonist for Parkinson's Disease.

Compound 7-16 was designed and synthesized in our previous study and was identified as a more potential selective 5-HT2A receptor antagonist and inverse agonist for treating Parkinson's disease psychosis (PDP). Then, the metabolism, disposition, and excretion properties of 7-16 and its potential inhibition on transporters were investigated in this study to highlight advancements in the understanding of its therapeutic mechanisms. The results indicate that a total of 10 metabolites of 7-16/[14C]7-16 were identified and determined in five species of liver microsomes and in rats using UPLC-Q Exactive high-resolution mass spectrometry combined with radioanalysis. Metabolites formed in human liver microsomes could be covered by animal species. 7-16 is mainly metabolized through mono-oxidation (M470-2) and N-demethylation (M440), and the CYP3A4 isozyme was responsible for both metabolic reactions. Based on the excretion data in bile and urine, the absorption rate of 7-16 was at least 74.7%. 7-16 had weak inhibition on P-glycoprotein and no effect on the transport activity of OATP1B1, OATP1B3, OAT1, OAT3, and OCT2 transporters. The comprehensive pharmacokinetic properties indicate that 7-16 deserves further development as a new treatment drug for PDP.

Non-canonical substrate recognition by the human WDR26-CTLH E3 ligase regulates prodrug metabolism.

The yeast glucose-induced degradation-deficient (GID) E3 ubiquitin ligase forms a suite of complexes with interchangeable receptors that selectively recruit N-terminal degron motifs of metabolic enzyme substrates. The orthologous higher eukaryotic C-terminal to LisH (CTLH) E3 complex has been proposed to also recognize substrates through an alternative subunit, WDR26, which promotes the formation of supramolecular CTLH E3 assemblies. Here, we discover that human WDR26 binds the metabolic enzyme nicotinamide/nicotinic-acid-mononucleotide-adenylyltransferase 1 (NMNAT1) and mediates its CTLH E3-dependent ubiquitylation independently of canonical GID/CTLH E3-family substrate receptors. The CTLH subunit YPEL5 inhibits NMNAT1 ubiquitylation and cellular turnover by WDR26-CTLH E3, thereby affecting NMNAT1-mediated metabolic activation and cytotoxicity of the prodrug tiazofurin. Cryoelectron microscopy (cryo-EM) structures of NMNAT1- and YPEL5-bound WDR26-CTLH E3 complexes reveal an internal basic degron motif of NMNAT1 essential for targeting by WDR26-CTLH E3 and degron mimicry by YPEL5's N terminus antagonizing substrate binding. Thus, our data provide a mechanistic understanding of how YPEL5-WDR26-CTLH E3 acts as a modulator of NMNAT1-dependent metabolism.

Targeting SHMTs and MTHFDs in cancer: attractive opportunity for anti-tumor strategy.

One-carbon metabolism is a universal metabolic process that mediates the transfer of one-carbon units for purine and thymidine synthesis. One-carbon metabolism has been found to be dysregulated in various cancer types due to its role in production of purine and pyrimidine nucleotides, epigenetic program, and redox homeostasis. One-carbon metabolism is composed a network of one-carbon metabolic enzymes. Disturbing the expression and enzymatic activity of these one-carbon metabolic enzymes could lead to fluctuations of metabolites in the tumor microenvironment. Serine hydroxymethyltransferases (SHMTs) and methylenetetrahydrofolate dehydrogenases (MTHFDs) are gradually recognized as important one-carbon metabolic enzymes for regulating tumor initiation and development, representing potential therapeutic targets for anti-tumor strategies. In the review, we primarily focused on the role of SHMTs and MTHFDs in cancer. Several inhibitors targeting MTHFDs and SHMTs have exert its potential to decrease tumor burden and inhibit tumor proliferation, highlighting the potential of targeting one-carbon metabolic enzymes for anti-cancer strategies.

Sublethal effect of chlorpyrifos on predatory behavior and physiology of Eocanthecona furcellata (Hemiptera: Pentatomidae).

Insecticides have been known to reduce the predation efficacy of natural enemies. However, the mechanism of the sublethal effect of insecticides on the functional response of predators remains unclear. This study investigated the sublethal effects of the broad-spectrum insecticide chlorpyrifos on the predatory bug Eocanthecona furcellata (Wolff), which is a potential biological control agent against pests in integrated pest management (IPM) programs. After exposure to a sublethal concentration of chlorpyrifos, the predation capacity and the maximum predatory number of E. furcellata increased by 11.27 and 15.26%, respectively, with prey handling time decreased by 15.07%, and the searching efficiency increased by 5.88-12.61%. Additionally, the intraspecific interference effect was enhanced. Glutathione S-transferase (GST) activity was significantly decreased after 12- to 60-h treatment. At 12 h after treatment, the expression levels of GST gene (GST3), acetylcholinesterase gene (AChE), and cytochrome P450 monooxygenasegene (cyp6B1) were significantly up-regulated by 1.47-, 1.48-, and 2.05-fold, respectively, while GST gene (GST1) was significantly down-regulated by 16.67-fold. These results indicated that a sublethal chlorpyrifos concentration inhibited the GST activity and stimulated the predatory behavior of E. furcellata. The results will advance our understanding of the toxicological mechanism of predatory stink bug responses to insecticides and predict chlorpyrifos' effects on predators in an IPM program.

Effects of Yinzhihuang on Alleviating Cyclosporine A-Induced Cholestatic Liver Injury via Farnesoid X Receptor-Mediated Regulation of Transporters and Enzymes in Vitro and in Vivo.

Yinzhihuang (YZH), a traditional Chinese medicine prescription, was widely used to treat cholestasis. Cholestatic liver injury limited the use of the immunosuppressive drug cyclosporine A (CsA) in preventing organ rejection after solid organ transplantation. Clinical evidences suggested that YZH could enhance bile acids and bilirubin clearance, providing a potential therapeutic strategy against CsA-induced cholestasis. Nevertheless, it remains unclear whether YZH can effectively alleviate CsA-induced cholestatic liver injury, as well as the molecular mechanisms responsible for its hepatoprotective effects. The purpose of the present study was to investigate the hepatoprotective effects of YZH on CsA-induced cholestatic liver injury and explore its molecular mechanisms in vivo and vitro. The results demonstrated that YZH significantly improved the CsA-induced cholestatic liver injury and reduced the level of liver function markers in serum of Sprague-Dawley (SD) rats. Targeted protein and gene analysis indicated that YZH increased bile acids and bilirubin efflux into bile through the regulation of multidrug resistance-associated protein 2 (Mrp2), bile salt export pump (Bsep), sodium taurocholate cotransporting polypeptide (Ntcp) and organic anion transporting polypeptide 2 (Oatp2) transport systems, as well as upstream nuclear receptors farnesoid X receptor (Fxr). Moreover, YZH modulated enzymes involved in bile acids synthesis and bilirubin metabolism including Cyp family 7 subfamily A member 1 (Cyp7a1) and uridine 5'-diphosphate (UDP) glucuronosyltransferase family 1 member A1 (Ugt1a1). Furthermore, the active components geniposidic acid, baicalin and chlorogenic acid exerted regulated metabolic enzymes and transporters in LO2 cells. In conclusion, YZH may prevent CsA-induced cholestasis by regulating the transport systems, metabolic enzymes, and upstream nuclear receptors Fxr to restore bile acid and bilirubin homeostasis. These findings highlight the potential of YZH as a therapeutic intervention for CsA-induced cholestasis and open avenues for further research into its clinical applications.

Which can Predict the Outcome of Antidepressants: Metabolic Genes or Pharmacodynamic Genes?

Drug therapy is the primary modality for depression; however, its outcome is often unpredictable, ranging from beneficial effects to serious adverse effects. Genetic variations in drug metabolizing enzymes and pharmacodynamic molecules are responsible for a considerable proportion of interindividual differences in the effectiveness and toxicity of antidepressants. For the improvement in the use of antidepressants, the focus is mainly on personalized treatment emphasizing interindividual differences in genes. This study provides a comprehensive review of the literature on the clinical applications of pharmacogenomics for antidepressant therapy. The polymorphisms of metabolizing enzymes (CYP2D6, CYP2C19, and others) governing the pharmacokinetic behavior of drugs are potential predictors of side effects or treatment failure with medications and there are good pharmacogenetic clinical recommendations for a wide selection of psychopharmacological agents based on functional diplotypes of CYP2C19 and CYP2D6. The relationship between pharmacodynamic genes, including FKBP5, SLC6A4, BDNF, ABCB1, HTR1A, and HTR2A, and clinical outcomes varies in different races. Receptors that are currently used as drug targets for antidepressant drugs are evolutionarily conserved to a higher extent than genes encoding drug metabolism, and the actionability of pharmacodynamic-related genotyping is currently still questionable. The limited availability of largescale, long-term clinical studies on different races and medications currently impedes the implementation of pharmacogenomics in antidepressant treatment. The use of pharmacokinetic and pharmacodynamic modeling, and therapeutic drug monitoring combined with genetic, somatic, dietary, and environmental factors represents a promising avenue for improving the precision and effectiveness of antidepressant therapy.

Yeast polysaccharide mitigated oxidative injury in broilers induced by mixed mycotoxins via regulating intestinal mucosal oxidative stress and hepatic metabolic enzymes.

This study was aimed to investigate the effects of yeast polysaccharides (YPS) on growth performance, intestinal health, and aflatoxin metabolism in livers of broilers fed diets naturally contaminated with mixed mycotoxins (MYCO). A total of 480 one-day-old Arbor Acre male broilers were randomly allocated into a 2 × 3 factorial arrangement of treatments (8 replicates with 10 birds per replicate) for 6 wk to assess the effects of 3 levels of YPS (0, 1, or 2 g/kg) on the broilers fed diets contaminated with or without MYCO (95 µg/kg aflatoxin B1, 1.5 mg/kg deoxynivalenol, and 490 µg/kg zearalenone). Results showed that mycotoxins contaminated diets led to significant increments in serum malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, mRNA expressions of TLR4 and 4EBP1 associated with oxidative stress, mRNA expressions of CYP1A1, CYP1A2, CYP2A6, and CYP3A4 associated with hepatic phase Ⅰ metabolizing enzymes, mRNA expressions of p53 associated with hepatic mitochondrial apoptosis, and AFB1 residues in the liver (P < 0.05); meanwhile dietary MYCO decreased the jejunal villus height (VH), villus height/crypt depth (VH/CD), the activity of serum total antioxidant capacity (T-AOC), mRNA expressions of jejunal HIF-1α, HMOX, and XDH associated with oxidative stress, mRNA expressions of jejunal CLDN1, ZO1, and ZO2, and mRNA expression of GST associated with hepatic phase Ⅱ metabolizing enzymes of broilers (P < 0.05). Notably, the adverse effects induced by MYCO on broilers were mitigated by supplementation with YPS. Dietary YPS supplementation reduced the concentrations of serum MDA and 8-OHdG, jejunal CD, mRNA expression of jejunal TLR2, and 4EBP1, hepatic CYP1A2, and p53, and the AFB1 residues in the liver (P < 0.05), and elevated the serum T-AOC and SOD, jejunal VH, and VH/CD, and mRNA expression of jejunal XDH, hepatic GST of broilers (P < 0.05). There were significant interactions between MYCO and YPS levels on the growth performance (BW, ADFI, ADG, and F/G) at d 1 to 21, d 22 to 42, and d 1 to 42, serum GSH-Px activity, and mRNA expression of jejunal CLDN2 and hepatic ras of broilers (P < 0.05). In contrast with MYCO group, the addition of YPS increased BW, ADFI, and ADG, the serum GSH-Px activity (14.31%-46.92%), mRNA levels of jejunal CLDN2 (94.39%-103.02%), decreased F/G, and mRNA levels of hepatic ras (57.83%-63.62%) of broilers (P < 0.05). In conclusion, dietary supplements with YPS protected broilers from mixed mycotoxins toxicities meanwhile keeping normal performance of broilers, presumably via reducing intestinal oxidative stress, protecting intestinal structural integrity, and improving hepatic metabolic enzymes to minimize the AFB1 residue in the liver and enhance the performance of broilers.

Cytoophidia and filaments: you must unlearn what you have learned.

The nucleotide CTP can be synthesized de novo from UTP via the metabolic enzyme CTP synthase (CTPS). As a textbook enzyme, CTPS has been extensively studied for seven decades. However, it came as a surprise when CTPS was found to form snake-shaped mesoscale cytoophidia in fruit fly cells. Since 2010, more and more studies have demonstrated that CTPS can form cytoophidia within the cells across all three domains of life. Oligomers of CTPS form filaments that are undetectable under light microscopy. This review summarizes our current understanding of cytoophidia and filaments, highlighting some basic features such as conservation, morphology and functions of the two levels of CTPS structures.

Targeting serine-glycine-one-carbon metabolism as a vulnerability in cancers.

The serine-glycine-one-carbon (SGOC) metabolic pathway is critical for DNA methylation, histone methylation, and redox homeostasis, in addition to protein, lipid, and nucleotide biosynthesis. The SGOC pathway is a crucial metabolic network in tumorigenesis, wherein the outputs are required for cell survival and proliferation and are particularly likely to be co-opted by aggressive cancers. SGOC metabolism provides an integration point in cell metabolism and is of crucial clinical significance. The mechanism of how this network is regulated is the key to understanding tumor heterogeneity and overcoming the potential mechanism of tumor recurrence. Herein, we review the role of SGOC metabolism in cancer by focusing on key enzymes with tumor-promoting functions and important products with physiological significance in tumorigenesis. In addition, we introduce the ways in which cancer cells acquire and use one-carbon unit, and discuss the recently clarified role of SGOC metabolic enzymes in tumorigenesis and development, as well as their relationship with cancer immunotherapy and ferroptosis. The targeting of SGOC metabolism may be a potential therapeutic strategy to improve clinical outcomes in cancers.

Exposure to Nickel Oxide Nanoparticles Induces Alterations in Antioxidant System, Metabolic Enzymes and Nutritional Composition in Muscles of Heteropneustes fossilis.

The current study was performed to explore potential toxic effect of nickel oxide nanoparticles (NiO NPs) on muscle tissue of catfish, Heteropneustes fossilis. Fishes were exposed to different concentrations of NiO NPs (12 mg/L, 24 mg/L, 36 mg/L and 48 mg/L) for a period of 14 days. Results revealed that NiO NPs caused significant increase in Ni accumulation, metallothionein content, lipid peroxidation and activity of different antioxidant enzymes (catalase, glutathione s transferase and glutathione reductase) while decrease in activity of superoxide dismutase (p < 0.05). Data also reported induction of Na+/K+ ATPase activity initially and then its decrease in concentration dependent manner. Fourier transform infrared spectroscopy revealed shift and changes in spectra of muscle of NiO NPs treated fishes. Fluctuations in activity of aspartate amino transferase, alanine amino transferase and alkaline phosphatase were also noticed. Nutritional contents like protein, lipid, and moisture significantly reduced while glucose and ash percent increased.

Enzyme-Catalyzed Hydrogen-Deuterium Exchange between Environmental Pollutants and Enzyme-Regulated Endogenous Metabolites.

Environmental pollutants can disrupt the homeostasis of endogenous metabolites in organisms, leading to metabolic disorders and syndromes. However, it remains highly challenging to efficiently screen for critical biological molecules affected by environmental pollutants. Herein, we found that enzyme could catalyze hydrogen-deuterium (H-D) exchange between a deuterium-labeled environmental pollutant [D38-bis(2-ethylhexyl) phthalate (D38-DEHP)] and several groups of enzyme-regulated metabolites [cardiolipins (CLs), monolysocardiolipins (MLCLs), phospholipids (PLs), and lysophospholipids (LPLs)]. A high-throughput scanning identified the D-labeled endogenous metabolites in a simple enzyme [phospholipase A2 (PLA2)], enzyme mixtures (liver microsomes), and living organisms (zebrafish embryos) exposed to D38-DEHP. Mass fragmentation and structural analyses showed that similar positions were D-labeled in the CLs, MLCLs, PLs, and LPLs, and this labeling was not attributable to natural metabolic transformations of D38-DEHP or incorporation of its D-labeled side chains. Molecular docking and competitive binding analyses revealed that DEHP competed with D-labeled lipids for binding to the active site of PLA2, and this process mediated H-D exchange. Moreover, competitive binding of DEHP against biotransformation enzymes could interfere with catabolic or anabolic lipid metabolism and thereby affect the concentrations of endogenous metabolites. Our findings provide a tool for discovering more molecular targets that complement the known toxic endpoints of metabolic disruptors.

Pharmacokinetic Drug-Drug Interactions Involving Antiretroviral Agents: An Update.

Antiretroviral therapy is the recognized treatment for human immunodeficiency virus (HIV) infection involving several antiviral agents. Even though highly active antiretroviral therapy has been proven to be very effective in suppressing HIV replication, the antiretroviral drugs, belonging to different pharmacological classes, present quite complex pharmacokinetic properties such as extensive drug metabolism and transport by membrane-associated drug carriers. Moreover, due to uncomplications or complications in HIV-infected populations, an antiretroviralbased multiple-drug coadministration therapy strategy is usually applied for treatment effect, thus raising the possibility of drug-drug interactions between antiretroviral drugs and common drugs such as opioids, stains, and hormonal contraceptives. Herein, thirteen classical antiretroviral drugs approved by US Food and Drug Administration were summarized. Besides, relative drug metabolism enzymes and transporters known to interact with those antiretroviral drugs were detailed and described. Furthermore, one after the summarized antiretroviral drugs, the drug-drug interactions between two antiretroviral drugs or antiretroviral drug - conventional medical drugs of the past decade were discussed and summarized. This review is intended to deepen the pharmacological understanding of antiretroviral drugs and promote more secure clinical applications for antiretroviral drugs to treat HIV.

Dietary Responses of Dementia-Related Genes Encoding Metabolic Enzymes.

The age-related loss of the cognitive function is a growing concern for global populations. Many factors that determine cognitive resilience or dementia also have metabolic functions. However, this duality is not universally appreciated when the action of that factor occurs in tissues external to the brain. Thus, we examined a set of genes involved in dementia, i.e., those related to vascular dementia, Alzheimer's disease, Parkinson's disease, and the human metabolism for activity in 12 metabolically active tissues. Mining the Genotype-Tissue Expression (GTEx) data showed that most of these metabolism-dementia (MD) genes (62 of 93, 67%) exhibit a higher median expression in any of the metabolically active tissues than in the brain. After identifying that several MD genes served as blood-based biomarkers of longevity in other studies, we examined the impact of the intake of food, nutrients, and other dietary factors on the expression of MD genes in whole blood in the Framingham Offspring Study (n = 2134). We observed positive correlations between flavonoids and HMOX1, taurine and UQCRC1, broccoli and SLC10A2, and myricetin and SLC9A8 (p < 2.09 × 10-4). In contrast, dairy protein, palmitic acid, and pie were negatively correlated, respectively, with the expression of IGF1R, CSF1R, and SLC9A8, among others (p < 2.92 × 10-4). The results of this investigation underscore the potential contributions of metabolic enzyme activity in non-brain tissues to the risk of dementia. Specific epidemiological or intervention studies could be designed using specific foods and nutrients or even dietary patterns focused on these foods and nutrients that influence the expression of some MD genes to verify the findings presented here.

Comparative study on the gene expression of corticosterone metabolic enzymes in embryonic tissues between Tibetan and broiler chickens.

Glucocorticoids (GCs) are an essential mediator hormone that can regulate animal growth, behavior, the phenotype of offspring, and so on, while GCs in poultry are predominantly corticosterones. The biological activity of GCs is mainly regulated by the intracellular metabolic enzymes, including 11ß-hydroxysteroid dehydrogenases 1 (11ß-HSD1), 11ß-hydroxysteroid dehydrogenases 2 (11ß-HSD2), and 20-hydroxysteroid dehydrogenase (20-HSD). To investigate the embryonic mechanisms of phenotypic differences between breeds, we compared the expression of corticosterone metabolic enzyme genes in the yolk-sac membrane and chorioallantoic membrane (CAM). We described the tissue distribution and ontogenic patterns of corticosterone metabolic enzymes during embryonic incubation between Tibetan and broiler chickens. Forty fertilized eggs from Tibetan and broiler chickens were incubated under hypoxic and normoxic conditions, respectively. Real-time fluorescence quantitative PCR was used to examine the expression of 11ß-HSD1/2, and 20-HSD mRNA in embryonic tissues. The results showed that the expression levels of yolk-sac membrane mRNA of 11ß-HSD2 and 20-HSD in Tibetan chickens on E14 (embryonic day of 14) were significantly lower than those of broiler chickens (P < 0.05), and these genes expression of CAM in Tibetan chickens were higher than those of broiler chickens (P < 0.05). In addition, the three genes in the yolk-sac membrane and CAM were followed by a down-regulation on E18 (embryonic day of 18). The 11ß-HSD1 and 11ß-HSD2 genes followed a similar tissue-specific pattern: the expression level was more abundantly in the liver, kidney, and intestine, with relatively lower abundance in the hypothalamus and muscle, and the expression level of 20-HSD genes in all tissues tested was higher. In the liver, 20-HSD of both Tibetan and broiler chickens showed different ontogeny development patterns, and hepatic mRNA expression of 20-HSD in broiler chickens was significantly higher than that of Tibetan chickens of the same age from E14 to E18 (P < 0.05). This study preliminarily revealed the expression levels of cortisol metabolic genes in different tissues during the development process of Tibetan and broiler chicken embryos. It provided essential information for in-depth research of the internal mechanism of maternal GCs programming on offspring.

Thermo-L-Asparaginases: From the Role in the Viability of Thermophiles and Hyperthermophiles at High Temperatures to a Molecular Understanding of Their Thermoactivity and Thermostability.

L-asparaginase (L-ASNase) is a vital enzyme with a broad range of applications in medicine, food industry, and diagnostics. Among various organisms expressing L-ASNases, thermophiles and hyperthermophiles produce enzymes with superior performances-stable and heat resistant thermo-ASNases. This review is an attempt to take a broader view on the thermo-ASNases. Here we discuss the position of thermo-ASNases in the large family of L-ASNases, their role in the heat-tolerance cellular system of thermophiles and hyperthermophiles, and molecular aspects of their thermoactivity and thermostability. Different types of thermo-ASNases exhibit specific L-asparaginase activity and additional secondary activities. All products of these enzymatic reactions are associated with diverse metabolic pathways and are important for mitigating heat stress. Thermo-ASNases are quite distinct from typical mesophilic L-ASNases based on structural properties, kinetic and activity profiles. Here we attempt to summarize the current understanding of the molecular mechanisms of thermo-ASNases' thermoactivity and thermostability, from amino acid composition to structural-functional relationships. Research of these enzymes has fundamental and biotechnological significance. Thermo-ASNases and their improved variants, cloned and expressed in mesophilic hosts, can form a large pool of enzymes with valuable characteristics for biotechnological application.

Extracellular-matrix mechanics regulate cellular metabolism: A ninja warrior behind mechano-chemo signaling crosstalk.

Mechanical forces are the indispensable constituent of environmental cues, such as gravity, barometric pressure, vibration, and contact with bodies, which are involved in pattern and organogenesis, providing mechanical input to tissues and determining the ultimate fate of cells. Extracellular matrix (ECM) stiffness, the slow elastic force, carries the external physical force load onto the cell or outputs the internal force exerted by the cell and its neighbors into the environment. Accumulating evidence illustrates the pivotal role of ECM stiffness in the regulation of organogenesis, maintenance of tissue homeostasis, and the development of multiple diseases, which is largely fulfilled through its systematical impact on cellular metabolism. This review summarizes the establishment and regulation of ECM stiffness, the mechanisms underlying how ECM stiffness is sensed by cells and signals to modulate diverse cell metabolic pathways, and the physiological and pathological significance of the ECM stiffness-cell metabolism axis.