Expression Of Pyruvate Kinase Research Articles

Expression of pyruvate kinase, malate and octopine dehydrogenase genes in the gills of the Mediterranean mussel Mytilus galloprovincialis (Lamarck, 1819) under conditions of hypoxia and reoxygenation

The effect of hypoxia on the expression level of pyruvate kinase (PKM), octopine dehydrogenase (OcDH) and malate dehydrogenase (MDH) genes in the gill tissue of the Mediterranean mussel Mytilus galloprovincialis (L., 1819) was studied experimentally. The control group of mollusks was kept at 9–10°C and the oxygen level in the water was 8.5 mgO2 l–1. Experimental – at 9–10°C and 2.2 mgO2 l–1. The exposure was 24 and 72 hours. Some of the individuals were subsequently subjected to the reoxygenation procedure. Under conditions of hypoxia, the expression level of OcDH and MDH genes increased by 3 and 2 times, respectively (p 0.05). At the same time, OcDH expression showed sensitivity to the oxygen content in the medium. Under the conditions of reoxygenation, the process was completely suppressed. The expression of the PKM gene, on the contrary, did not depend on hypoxic effects and remained at the level of control values.

Investigation of copper-induced intestinal damage and proteome alterations in Takifugu rubripes: Potential health risks and environmental toxicology detection

Copper is one of the predominant water pollutants. Excessive exposure to copper can cause harm to animal health, affecting the central nervous system and causing blood abnormalities. Cuproptosis is a novel form of cell death that differs from previous programmed cell death methods. However, the impact of copper on the intestines remains unclear. Therefore, we investigated the effects of different concentrations of copper exposure on the intestinal proteome of Takifugu rubripes (T. rubripes). Relevant biomarkers were used to detect cuproptosis. We revealed the crosstalk relationship between cuproptosis and self-rescue at different concentrations, and discussed the feasibility of using potential cuproptosis indicators as anti-infection factors. We observed intestinal damage in the three copper exposure groups, especially in T. rubripes treated with 100 and 500 μg/L copper, with shedding and breakage of intestinal villus and fuzzy and loose structure of intestinal mucosa. The presence of copper stress not only causes cuproptosis but also oxidative damage caused by reactive oxygen species (ROS). The results of quantitative proteomics by TMT showed that compared to the 50 and 100 μg/L copper exposure groups, the expression of glutaminase, pyruvate kinase, and skin mucus lectin in the 500 μg/L group was significantly increased. The positive mediators COX5A and CTNNB1, as well as the negative mediators CD4 and FDXR, were found to be differentially expressed. Using the protein expression trends of cuproptosis indicator factors FDX1 and DLAT to indicate the concentration of copper ions in the environment. In addition, we found a new effect of promoting ferroptosis: providing additional copper ions can activate the phenomenon of ferroptosis. Our results expand our understanding of the potential health risks of copper in T. rubripes. At the same time, it is of great significance for the process of copper poisoning and the development of new environmental toxicology detection reagents.

Expression of Pyruvate Kinase, Malate and Octopine Dehydrogenase Genes in the Gills of the Mediterranean Mussel Mytilus galloprovincialis (Lamarck, 1819) under Conditions of Hypoxia and Reoxygenation

Expression of Pyruvate Kinase, Malate and Octopine Dehydrogenase Genes in the Gills of the Mediterranean Mussel Mytilus galloprovincialis (Lamarck, 1819) under Conditions of Hypoxia and Reoxygenation

Effects of sodium lactate injection on meat quality and lactate content in broiler chickens: emphasis on injection method and dosage

This study aims to develop an experimental model of high lactate levels in broilers to mimic the condition of birds under stress or diseases and evaluate its consequent effects on meat quality. The injection sites and dosage effects were compared separately in 2 experiments. Experiment 1 includes 3 injection sites: intraperitoneal injection, intramuscular injection, and subcutaneous injection. Experiment 2 was a dosage experiment based on the results of Experiment 1: sodium lactate intraperitoneal injection group with 1.5, 3, 6 mM concentration. The results showed that injecting sodium lactate intraperitoneally, intramuscularly, or subcutaneously all significantly decreased body weight and breast muscle weight while elevating lactic acid levels in both the blood and breast muscle of broilers. Moreover, all 3 injection methods caused a significant reduction in pH24h and an increase in the shear force value of breast muscle. In addition, dose-response experiments of intraperitoneal injection showed that a concentration of 3 mM and 6 mM were significantly decreased body weight and breast muscle weight in broiler chickens, accompanied by a notable increase in breast muscle lactate content. Compared to the control group, intraperitoneal injections of 1.5 mM, 3 mM, and 6 mM sodium lactate treatments significantly reduced the yellowness values of the breast muscle. As the dose of sodium lactate increased, the shear force value of the breast meat exhibited linear and quadratic increments, while the drip loss decreased linearly. Intraperitoneal injection of 3 mM sodium lactate also significantly reduced the pH24h of broiler breast muscle. In addition, an increased dose of lactate injections up-regulated the glycolytic pathway responsible for endogenous lactate production in the breast muscle by upregulating the expression of phosphofructokinase, pyruvate kinase and lactate dehydrogenase A. In conclusion, intraperitoneal injection of sodium lactate at 3 mM directly increased breast muscle lactate levels, providing a valuable method for establishing a high-level lactate model in poultry.

Gckr depletion leads to growth retardation and diet-dependent visceral obesity in red crucian carp (Carassius auratus red var.)

There exists a notable contrast in the carbohydrate utilization capacity between fish and mammals. In mammals, the glucokinase regulatory protein (GCKR) is known to exert inhibitory effects on glycolysis by binding to glucokinase (GCK), but its role in fish remains unexplored. In this study, the function of gckr in red crucian carp (Carassius auratus red var.), hereafter referred to as RCC, was investigated through its knockout. Under normal dietary conditions, the growth rate of gckr knockout RCC was significantly lower compared to wild-type (WT) RCC reared in the same environment. Subsequent analysis found that gckr knockout RCC exhibited significantly higher serum glucose levels at 1 h post-feeding or glucose injection (hpi), while the difference was abolished at 3 h. Therefore, the metabolic characteristics at 1 and 3 hpi were evaluated between WT and gckr knockout RCC. The results revealed that gckr knockout led to impaired insulin signaling and glycolysis, as evidenced by a reduction in serum insulin level, hepatic insulin receptor a and pyruvate kinase expression, GCK contents, and pyruvate levels at 1 hpi. Additionally, gckr knockout resulted in compromised gluconeogenesis, as indicated by a significant decrease in hepatic expression of fructose-1,6-bisphosphatase 1 and glucose-6-phosphatase at 1 hpi, while it did not affect glycogen accumulation after glucose injection. Regarding lipid metabolism, gckr knockout caused a transient decrease in triglyceride level and reduced expression of fatty acid synthase after glucose injection. Moreover, decreased hepatic peroxisome proliferator activated receptor alpha (ppara) transcripts and proteins were observed in gckr knockout RCC at 1 dpi, indicating a reduced capacity for β-oxidation due to Gckr deficiency. Interestingly, when fed a high-lipid diet, gckr knockout resulted in a significant increase in visceral mass with higher triglyceride level, accompanied by attenuated PPARα signaling. Taken together, this study provides evidence that Gckr-mediated maintenance of Gck contributes to the facilitation of postprandial glycolysis, gluconeogenesis, lipogenesis, and fatty acid β-oxidation in RCC. This study further suggests that enhancing glycolysis may promote growth and liver health in fish under high lipid dietary conditions.

Metabolic engineering of Escherichia coli for high-level production of the biodegradable polyester monomer 2-pyrone-4,6-dicarboxylic acid

2-Pyrone-4,6-dicarboxylic acid (PDC), a chemically stable pseudo-aromatic dicarboxylic acid, is a promising building block compound for manufacturing biodegradable polyesters. This study aimed to construct high-performance cell factories enabling the efficient production of PDC from glucose. Firstly, the effective enzymes of the PDC biosynthetic pathway were overexpressed on the chromosome of the 3-dehydroshikimate overproducing strain. Consequently, the one-step biosynthesis of PDC from glucose was achieved. Further, the PDC production was enhanced by multi-copy integration of the key gene PsligC encoding 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase and co-expression of Vitreoscilla hemoglobin. Subsequently, the PDC production was substantially improved by redistributing the metabolic flux for cell growth and PDC biosynthesis based on dynamically downregulating the expression of pyruvate kinase. The resultant strain PDC50 produced 129.37 g/L PDC from glucose within 78 h under fed-batch fermentation conditions, with a yield of 0.528 mol/mol and an average productivity of 1.65 g/L/h. The findings of this study lay the foundation for the potential industrial production of PDC.

Domestication Gene Mlx and Its Partner Mondo Are Involved in Controlling the Larval Body Size and Cocoon Shell Weight of Bombyx mori.

Bombyx mori was domesticated from Bombyx mandarina. The long-term domestication of the silkworm has brought about many remarkable changes to its body size and cocoon shell weight. However, the molecular mechanism underlying the improvement in the economic characteristics of this species during domestication remains unclear. In this study, we found that a transposable element (TE)-Bm1-was present in the upstream regulatory region of the Mlx (Max-like protein X) gene in wild silkworms but not in all domesticated silkworms. The absence of Bm1 caused an increase in the promoter activity and mRNA content of Mlx. Mlx and its partner Mondo belong to the bHLHZ transcription factors family and regulate nutrient metabolism. RNAi of Mlx and Mondo decreased the expression and promoter activity of glucose metabolism-related genes (trehalose transport (Tret), phosphofructokinase (PFK), and pyruvate kinase (PK)), lipogenic genes (Acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS)), and glutamine synthesis gene (Glutamine synthase 2, (GS2)). Furthermore, the transgenic overexpression of Mlx and Mondo in the fat body of silkworms increased the larval body size, cocoon shell weight, and egg number, but the silencing of the two genes resulted in the opposite phenotypes. Our results reveal the molecular mechanism of Mlx selection during domestication and its successful use in the molecular breeding of Bombyx mori.

Changes in carbohydrate metabolism and soil microorganisms under the stress of polyamide and polyethylene nanoplastics during rice (Oryza sativa L.) growth

Nanoplastics (NPs) presence in agricultural soils can affect plant growth and impact the quality of agricultural products. To investigate the effect of polyamide (PA) NPs and polyethylene (PE) NPs on carbohydrate metabolism and soil microorganisms during rice growth, rice seedlings were exposed to soil containing 2 g/kg of 100 nm PA or 100 nm PE powder for 33 d. The results revealed that 100 nm PE reduced shoot length and dry weight of rice by 4.14 % and 15.68 %, respectively. Analyzing the expression of hexokinase-2 (HXK), phosphofructokinase-1 (PFK), pyruvate kinase (PK) and isocitrate dehydrogenase (IDH), which are four genes related to carbohydrate metabolism, 100 nm PA decreased the expression of PFK and increased the expression of PK and IDH. 100 nm PE increased the expression of HXK, PFK, PK, and IDH. The results of soil microorganisms showed that 100 nm PA significantly effects on 3 bacterial phyla (Bacteroidota, Deinococcota, and Desulfobacterota), whereas 100 nm PE significantly effects on phylum Rozellomycota, class Umbelopsidomycetes, and an unclassified Firmicutes. Our study provides direct evidence of the negative effects of PA and PE on rice, which may be important for assessing the risk of NPs on agroecosystems.

Thyme extract could overcome diabetes-induced reproductive dysfunction by inhibiting oxidative damage and increasing the expression of insulin receptor substrate and pyruvate kinase in the rat sperm.

Oxidative stress and disruption of energy metabolism in the reproductive system, especially sperm, play a significant role in diabetes-related infertility. Zataria multiflora Boissis (ZMB), a medicinal plant containing various bioactive compounds, may have efficacy in treating metabolic diseases and reproductive disorders. Therefore, the aim of this study was to investigate the effects of different doses of ZMB extract on diabetes-induced reproductive dysfunction by assessing oxidative damage and the gene expression of insulin receptor substrate (IRS) and pyruvate kinase (PK) in male rats' sperm. Sixty adult male Wistar rats were randomly divided into six groups; control (C), diabetes (D), and diabetic animals treated with glibenclamide (G, 50 mg/kg) and thyme extract (T100, T200, and T400). Diabetes was induced by intraperitoneal injection of Streptozotocin (STZ) (50 mg/kg). Insulin, glucose, oxidative and pro-inflammatory markers in the serum, and gene expressions of IRS, and PK were measured in the stored sperms in the epididymis. Changes in the process of spermatogenesis were assessed through the histological evaluation of the testis. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the quantity and quality of thyme extract. The study results indicated that body weight, food intake, and sperm parameters significantly improved in a dose-dependent manner in the T200 group compared to the other groups. Additionally, in the same group, pro-inflammatory biomarkers, DNA fragmentation, and MDA levels decreased, while the levels of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) enzymes in the stored epididymal sperm significantly improved compared to the other groups. The expression of IRS and PK, along with the mean counts of spermatogenesis cell lines (especially Sertoli cells), significantly increased in the T200 group. In conclusion, thymol appears to alleviate diabetes-induced reproductive dysfunction by inhibiting oxidative damage, improving the metabolic state, and upregulating the expression of IRS and PK genes in the sperm of male rats.

Bactericidal bissulfone B7 targets bacterial pyruvate kinase to impair bacterial biology and pathogenicity in plants.

The prevention and control of rice bacterial leaf blight (BLB) disease has not yet been achieved due to the lack of effective agrochemicals and available targets. Herein, we develop a series of novel bissulfones and a novel target with a unique mechanism to address this challenge. The developed bissulfones can control Xanthomonas oryzae pv. oryzae (Xoo), and 2-(bis(methylsulfonyl)methylene)-N-(4-chlorophenyl) hydrazine-1-carboxamide (B7) is more effective than the commercial drugs thiodiazole copper (TC) and bismerthiazol (BT). Pyruvate kinase (PYK) in Xoo has been identified for the first time as the target protein of our bissulfone B7. PYK modulates bacterial virulence via a CRP-like protein (Clp)/two-component system regulatory protein (regR) axis. The elucidation of this pathway facilitates the use of B7 to reduce PYK expression at the transcriptional level, block PYK activity at the protein level, and impair the interaction within the PYK-Clp-regR complex via competitive inhibition, thereby attenuating bacterial biology and pathogenicity. This study offers insights into the molecular and mechanistic aspects underlying anti-Xoo strategies that target PYK. We believe that these valuable discoveries will be used for bacterial disease control in the future.

Pyruvate kinase M in germ cells is essential for sperm motility and male fertility but not spermatogenesis.

Male germ cells employ specific metabolic pathways throughout their developmental stages. In a previous study, we discovered heightened expression of pyruvate kinase M (PKM), a pivotal glycolytic enzyme, in spermatogonia and spermatids. To gain deeper insights into PKM's roles in spermatogenesis, sperm function, and male fertility, we engineered a conditional-knockout mouse model ( Pkm -vKO mice) to selectively disrupt the Pkm gene within germ cells. Despite maintaining regular testicular histology and sperm morphology, the male Pkm -vKO mice were infertility, characterized by significant impairments in sperm motility and adenosine triphosphate (ATP) generation. In addition, Pkm -null spermatozoa exhibited similar deficits in protein tyrosine phosphorylation linked to capacitation, as well as compromised performance in in vitro fertilization experiments. To conclude, PKM's presence is not obligatory for the entirety of spermatogenesis in male germ cells; however, it emerges as a critical factor influencing sperm motility and overall male fertility.

Mitapivat reprograms the RBC metabolome and improves anemia in a mouse model of hereditary spherocytosis.

Hereditary spherocytosis (HS) is the most common, nonimmune, hereditary, chronic hemolytic anemia after hemoglobinopathies. The genetic defects in membrane function causing HS lead to perturbation of the RBC metabolome, with altered glycolysis. In mice genetically lacking protein 4.2 (4.2-/-; Epb42), a murine model of HS, we showed increased expression of pyruvate kinase (PK) isoforms in whole and fractioned RBCs in conjunction with abnormalities in the glycolytic pathway and in the glutathione (GSH) system. Mitapivat, a PK activator, metabolically reprogrammed 4.2-/- mouse RBCs with amelioration of glycolysis and the GSH cycle. This resulted in improved osmotic fragility, reduced phosphatidylserine positivity, amelioration of RBC cation content, reduction of Na/K/Cl cotransport and Na/H-exchange overactivation, and decrease in erythroid vesicles release in vitro. Mitapivat treatment significantly decreased erythrophagocytosis and beneficially affected iron homeostasis. In mild-to-moderate HS, the beneficial effect of splenectomy is still controversial. Here, we showed that splenectomy improves anemia in 4.2-/- mice and that mitapivat is noninferior to splenectomy. An additional benefit of mitapivat treatment was lower expression of markers of inflammatory vasculopathy in 4.2-/- mice with or without splenectomy, indicating a multisystemic action of mitapivat. These findings support the notion that mitapivat treatment should be considered for symptomatic HS.

Effects of Caraway and (S)-(+)-carvone Extract on the Expression of Genes Coding Key Glycolytic Enzymes in Streptozotocin-induced Diabetic Rats

Background: Diabetes mellitus is a metabolic disorder causing dysfunctional regulation of carbohydrate metabolism and contributing to multiple serious health challenges worldwide. Aims: This research explores the effect of caraway hydroalcoholic extract and (S)-(+)-carvone on the transcription of genes coding for key glycolytic enzymes in the liver of the diabetic rat treated with streptozotocin (STZ). Methods: In this experimental study, diabetes was established in four groups of rats by injecting 45 mg/kg of STZ intraperitoneally. Further normal rats that were not injected formed the control group. Over four weeks, the effects of caraway hydroalcoholic extract (150 and 250 mg/kg) and carvone (100 mg/kg) were evaluated using PCR and histopathological evaluation, specifically in the form of effects on the transcription process of genes coding key glycolytic enzymes in the liver of the diabetic rats. Results: Over the four-week assessment period, rats’ food intake, and therefore blood glucose levels, were decreased through the daily oral administration of carvone and caraway extract (150 mg/kg) when compared to those administered with further STZ. The expression of key glycolytic enzymes, including glucokinase, pyruvate kinase, and phosphofructokinase 1 in the liver of diabetic rats was restored to near-normal levels by carvone and caraway extract, especially at the 150 mg/kg dose. Histopathological evaluation of diabetic rat liver demonstrated that administration of caraway extract and carvone decreased the STZ-induced damage to liver tissue. Conclusion: 150 mg/kg of caraway extract strongly regulates glycolysis by regulating the gene expression of key glycolytic enzymes in diabetic rats.

Effects of Selenium Enrichment on Dough Fermentation Characteristics of Baker's Yeast.

In this research, the effect of selenium (Se) enrichment on dough fermentation characteristics of yeast and the possible mechanisms was investigated. Then, the Se-enriched yeast was used as starter to make Se-enriched bread, and the difference between Se-enriched bread and common bread was investigated. It was found Se enrichment increased CO2 production and sugar consumption rate of Saccharomyces cerevisiae (S. cerevisiae) in dough fermentation, and had positive impacts on final volume and rheological index of dough. The mechanism is possibly related to higher activity and protein expression of hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), citrate synthase (CS), isocitrate dehydrogenase (ICD), and α-ketoglutarate dehydrogenase (α-KGDHC) in Se-enriched yeast. Moreover, Se-enriched bread (Se content: 11.29 μg/g) prepared by using Se-enriched yeast as starter exhibited higher overall acceptability on sensory, cell density in stomatal morphology, and better elasticity and cohesiveness on texture properties than common bread, which may be due to effect of higher CO2 production on dough quality. These results indicate Se-enriched yeast could be used as both Se-supplements and starter in baked-foods making.

Differential dose-response effect of cyclosporine A in regulating apoptosis and autophagy markers in MCF-7 cells.

Cyclosporine A (CsA) is an immunosuppressant primarily used at a higher dosage in transplant medicine and autoimmune diseases with a higher success rate. At lower doses, CsA exhibits immunomodulatory properties. CsA has also been reported to inhibit breast cancer cell growth by downregulating the expression of pyruvate kinase. However, differential dose-response effects of CsA in cell growth, colonization, apoptosis, and autophagy remain largely unidentified in breast cancer cells. Herein, we showed the cell growth-inhibiting effects of CsA by preventing cell colonization and enhancing DNA damage and apoptotic index at a relatively lower concentration of 2µM in MCF-7 breast cancer cells. However, at a higher concentration of 20µM, CsA leads to differential expression of autophagy-related genes ATG1, ATG8, and ATG9 and apoptosis-associated markers, such as Bcl-2, Bcl-XL, Bad, and Bax, indicating a dose-response effect on differential cell death mechanisms in MCF-7 cells. This was confirmed in the protein-protein interaction network of COX-2 (PTGS2), a prime target of CsA, which had close interactions with Bcl-2, p53, EGFR, and STAT3. Furthermore, we investigated the combined effect of CsA with SHP2/PI3K-AKT inhibitors showing significant MCF-7 cell growth reduction, suggesting its potential to use as an adjuvant during breast cancer therapy.

Evaluating the impact of the hexosamine biosynthesis pathway and O-GlcNAcylation on glucose metabolism in bovine granulosa cells

Granulosa cells (GCs) of ovarian follicles prefer glucose as a metabolic substrate for growth and maturation. Disruption of glucose utilization via the hexosamine biosynthesis pathway (HBP) impairs O-linked N-acetylglucosaminylation (O-GlcNAcylation) and inhibits proliferation of bovine GCs of both small (3–5 mm) and large (>8.5 mm) antral follicles. Knowing that 2–5% of all glucose in cells is utilized via the HBP, the aim of this study was to characterize glucose metabolism in bovine GCs and determine the impact of the HBP and O-GlcNAcylation on metabolic activity. The GCs were initially cultured in serum-containing medium to confluency and then sub-cultured in serum-free medium in 96 well plates (n = 10 ovary pairs). The cells were exposed to vehicle and inhibitors of the HBP and O-GlcNAcylation for 24 h. Extracellular acidification rate (ECAR; an indicator of glycolysis) and oxygen consumption rate (OCR; an indicator of oxidative phosphorylation) of the GCs were measured using a Seahorse xFe96 Analyzer, including the implementation of glycolytic and mitochondrial stress tests. GCs from small antral follicles exhibited overall greater metabolic activity than GCs from large antral follicles as evidenced by increased ECAR and OCR. Inhibition of the HBP and O-GlcNAcylation had no effect on the metabolic activity of GCs from either type of follicle. The glycolytic stress test indicated that GCs from both types of follicles possessed additional glycolytic capacity; but again, inhibition of the HBP and O-GlcNAcylation did not affect this. Interestingly, inhibition of cellular respiration by 2-Deoxy-D-glucose impaired OCR only in GCs from small antral follicles, but exposure to the mitochondrial stress test had no effect. Conversely, in GCs from large antral follicles, oxidative metabolism was impaired by the mitochondrial stress test and was accompanied by a concomitant increase in glycolytic metabolism. Immunodetection of glycolytic enzymes revealed that phosphofructokinase expression is increased in GCs of small antral follicles compared to large follicles. Inhibition of O-GlcNAcylation impaired the expression of hexokinase only in GCs of small antral follicles. Inhibition of O-GlcNAcylation also impaired the expression of phosphofructokinase, pyruvate kinase and pyruvate dehydrogenase in GCs of both types of follicles, but had no effect on the expression of lactate dehydrogenase. The results indicate that GCs of small antral follicles possess greater aerobic glycolytic capacity than GCs from large antral follicles; but disruption of the HBP and O-GlcNAcylation has little to no impact on metabolic activity.

Metabolic remodeling caused by heat hardening in the Mediterranean mussel Mytilus galloprovincialis.

Organisms can modify and increase their thermal tolerance faster and more efficiently after a brief exposure to sublethal thermal stress. This response is called 'heat hardening' as it leads to the generation of phenotypes with increased heat tolerance. The aim of this study was to investigate the impact of heat hardening on the metabolomic profile of Mytilus galloprovincialis in order to identify the associated adjustments of biochemical pathways that might benefit the mussels' thermal tolerance. Thus, mussels were exposed sequentially to two different phases (heat hardening and acclimation phases). To gain further insight into the possible mechanisms underlying the metabolic response of the heat-hardened M. galloprovincialis, metabolomics analysis was complemented by the estimation of mRNA expression of phosphoenolpyruvate carboxykinase (PEPCK), pyruvate kinase (PK) and alternative oxidase (AOX) implicated in the metabolic pathways of gluconeogenesis, glycolysis and redox homeostasis, respectively. Heat-hardened mussels showed evidence of higher activity of the tricarboxylic acid (TCA) cycle and diversification of upregulated metabolic pathways, possibly as a mechanism to increase ATP production and extend survival under heat stress. Moreover, formate and taurine accumulation provide an antioxidant and cytoprotective role in mussels during hypoxia and thermal stress. Overall, the metabolic responses in non-heat-hardened and heat-hardened mussels underline the upper thermal limits of M. galloprovincialis, set at 26°C, and are in accordance with the OCLTT concept. The ability of heat-hardened mussels to undergo a rapid gain and slow loss of heat tolerance may be an advantageous strategy for coping with intermittent and often extreme temperatures.

Administration of the Potential Probiotic Paenibacillus ehimensis NPUST1 Enhances Expression of Indicator Genes Associated with Nutrient Metabolism, Growth and Innate Immunity against Aeromonas hydrophila and Streptococcus indie Infections in Zebrafish (Danio rerio)

Probiotics as antibiotic alternatives for preventing and controlling infectious diseases are a relatively eco-friendly strategy in aquaculture. The bacteriocin-producing probiotic Paenibacillus ehimensis NPUST1 was isolated from tilapia culture pond water in our previous study. The present study demonstrated that P. ehimensis NPUST1 produced hydrolytic enzymes, including protease, amylase, cellulase, xylanase and lipase. The effects of P. ehimensis NPUST1 on zebrafish nutrient metabolism, growth performance and innate immunity were evaluated by measuring the expression of indicator genes in zebrafish after feeding P. ehimensis NPUST1 at doses of 106 and 107 CFU/g for 8 weeks. There was an obvious increase in the hepatic mRNA expression of carbohydrate metabolism-related genes, including glucokinase, hexokinase 1, glucose-6-phosphatase, and pyruvate kinase, and growth-related genes, including the growth hormone receptor and insulin-like growth factor-1. The expression of the innate immune-related genes including interleukin (IL)-1β, IL-6, IL-15, tumor necrosis factor-α, toll-like receptor (TLR)-1, TLR-4, complement component C3b and lysozyme were significantly increased in P. ehimensis NPUST1-supplemented fish. A significant reduction in cumulative mortality was exhibited in P. ehimensis NPUST1-supplemented fish after infection with Aeromonas hydrophila and Streptococcus iniae. In conclusion, our data suggested that P. ehimensis NPUST1 supplementation in feed could potentially improve nutrient metabolism and growth in addition to enhancing innate immunity and disease resistance against A. hydrophila and S. iniae in zebrafish.

The effect of insulin-loaded gold and carboxymethyl chitosan nanoparticles on gene expression of glucokinase and pyruvate kinase in rats with diabetes type 1.

The goal of this study was to see how effective subcutaneous (SC) insulin is and two different types of oral insulin-loaded nanoparticles (INS) including carboxymethyl chitosan nanoparticles (CMCNPs) and gold nanoparticles (AuNPs) separately and compare their effects on glucokinase, pyruvate kinase gene expressions, and other parameters in diabetes type one male Wistar rats. Seven groups of ten male Wistar rats for each group were formed at random including four control groups (n= 10) and three treatment groups (n= 10). The control groups consisted of four control groups (10 rats for each) and three treatment groups (10 rats for each). Normal control rats were not given any treatment, as were diabetic rats that were not given any treatment, and diabetic rats that were given oral nanoparticles (CMCNPs and AuNPs). Diabetic rats were given subcutaneous insulin, oral insulin-loaded carboxymethyl chitosan nanoparticles (INS-CMCNPs), and oral insulin-loaded gold nanoparticles (INS-AuNPs). The rats were treated for the final 3 weeks of the experiment, which lasted 4 weeks. CMCNPs and AuNPs presented a promising effect on pyruvate kinase and Glucokinase gene expressions compared to subcutaneous insulin. We also discovered that conjugating insulin to CMCNPs and AuNPs protects them from the insulin-degrading enzyme, which offers managed bioavailability. Furthermore, we investigated the effects of CMCNPs and AuNPs on several parameters and discovered that both have a significant effect in vivo, which enables glucose level regulation, and improves patient organ activity for better glucose consumption. PRACTICAL APPLICATIONS: In this paper, we discussed the effect of oral INS-CMCNPs and INS-AuNPs, and compared their effects on Glucokinase and pyruvate kinase gene expressions and other biochemical parameters in diabetes type one male Wistar rats. On the other hand, we investigated the impact of oral INS and subcutaneous insulin separately on the same parameters and their effect on the histology of the liver and pancreas of diabetic rats. According to our research, as we discussed the different mechanisms of INS-CMCNPs and INS-AuNPs, they presented a promising effect compared to SC insulin. They can be used to keep oral insulin safe from the environment of the gastrointestinal system to overcome all the barriers, improve the therapeutic, and clinical outcomes of insulin by maintaining its desired concentration inside the body, ending the panic of the patient from receiving insulin by the SC injection by increasing his satisfaction with receiving accurate oral insulin doses.

Zebrafish model of in utero glucose exposure alters developmental programming that leads to life‐long metabolic consequences

Background and AimOne in ten pregnancies in the US, suffers from Gestational Diabetes Mellitus (GDM). Offspring born to mothers who have GDM have a higher risk of developing Obesity, Type 2 diabetes and Non‐alcoholic fatty liver disease later in life. Although in utero glucose exposure provides evidence for developmental programming leading to metabolic disorders in adults, the molecular mechanisms are still unclear. We aim to understand the mechanisms implicated in developmental programming and their associated adult outcomes in a well‐established zebrafish model of fetal hyperglycemia that mimics the metabolic disorders in human GDM.MethodsWe developed a zebrafish model of fetal hyperglycemia by exposing embryos to high glucose (4.5% w/v) during the last day of embryogenesis from 96 to 120 hours post fertilization. Glucose level was detected in embryos and larvae homogenates and in adult serum by glucometer. Body composition was determined in adults by EchoMRI, gene expression of glycolytic, lipogenic (Acetyl‐CoA Carboxylase (acca) and mitochondria biogenesis (Peroxisome proliferator‐activated receptor‐gamma coactivator [PGC‐1α/β) markers were quantified by RT‐qPCR and acca by western blot. Lipid accumulation was detected by Oil‐Red‐O staining (ORO) and quantified by spectrophotometry. Triglyceride and cholesterol levels (ELISA), adiposity (Nile red staining) and mitochondrion number (mitotracker staining) were also evaluated. We also assessed if co‐administration of metformin or ND646 (known inhibitors of acca) with glucose can attenuate fetal hyperglycemia‐mediated metabolic outcomes.ResultsZebrafish embryos exposed to high glucose for 24 hrs are transiently hyperglycemic while normoglycemia is restored after glucose exposure. Larvae and adults with embryonic glucose exposure are normoglycemic. Embryos showed an upregulation of hexokinase and pyruvate Kinase expression when assessed at 120 hpf, but no change in expression was detected in larvae. Embryos exposed to glucose showed increased lipid accumulation by ORO staining (0.22 ±0.01 Vs 0.17±0.01) while larvae showed a 5‐fold increase in adiposity. Adult fish develop obesity characterized by increased BMI (0.83±26.34 Vs. 0.60± 33.89) kg/m2 and fat mass (12.07± 2.92 Vs 3.4± 0.4) g. Embryos showed increase in both acca mRNA expression (3‐folds) and activation (decreased phosphorylation). Interestingly, acca expression remained increased in larvae while glycemia was normal. Moreover, there was a significant increase in cholesterol (57.92± 0.7 Vs 34.8±1.01 µM) and triglyceride levels in glucose exposed embryos compared to controls (4.1± 0.75 Vs 0.98±0.27 µM). Our data in embryos revealed an increase in mitochondria number validated by an increase in the expression of PGC‐1α/β. Finally, ORO staining showed that embryonic lipid accumulation was decreased to normal levels, by metformin or ND646 exposure when co‐administered with glucose.Conclusion and significanceTogether our results show that embryonic glucose exposure alters developmental programming, including lipid homeostasis dysregulation that is persistent in larvae and adult. However, it can be rescued by pharmacological approaches.