D-mannose,essential for protein glycosylation,has been reported to have immunomodulatory effects and to maintain intestinal flora homeostasis.In addition to evaluating growth performance,we examined the impact of D-ma...D-mannose,essential for protein glycosylation,has been reported to have immunomodulatory effects and to maintain intestinal flora homeostasis.In addition to evaluating growth performance,we examined the impact of D-mannose on the structure of epithelial cells and apical junction complexes in the animal intestine.All 1800 grass carp(16.20±0.01 g)were randomly divided into six treatments with six replicates of 50 fish each and fed with six different levels of D-mannose(0.52,1.75,3.02,4.28,5.50 and 6.78 g/kg diet)for 70 d.The study revealed that D-mannose increased feed intake(P 0.05).D-mannose supplementation at 1.75 g/kg increased crude protein content in fish and lipid production value(P<0.05).D-mannose supplementation at 4.28 g/kg increased intestinal length,intestinal weight and fold height of grass carp compared to the control group(P<0.05).This improvement may be attributed to the phosphomannose isomerase(PMI)-mediated enhancement of glycolysis.This study found that D-mannose supplementation at 4.28 or 3.02 g/kg reduced serum diamine oxidase activity or D-lactate content(P<0.05)and improved cellular and intercellular structures for the first time.The improvement of cellular redox homeostasis involves alleviating endoplasmic reticulum(ER)stress through the inositol-requiring enzyme 1(IRE1),RNA-dependent protein kinase-like ER kinase(PERK),and activating transcription factor 6(ATF6)signaling pathways.The alleviation of ER stress may be linked to the phosphomannomutase(PMM)-mediated enhancement of protein glycosylation.In addition,ubiquitin-dependent[PTEN-induced putative kinase 1(PINK1)/Parkin]and ubiquitin-independent[BCL2-interacting protein 3-like(BNIP3L),BCL2-interacting protein 3(BNIP3),and FUN14 domain containing 1(FUNDC1)]mitophagy may play a role in maintaining cellular redox homeostasis.The enhancement of intercellular structures includes enhancing tight junction and adherent junction structures,which may be closely associated with the small Rho GTPase protein(RhoA)/the Rho-associated protein kinase(ROCK)signaling pathway.In conclusion,D-mannose improved intestinal cellular redox homeostasis associated with ER stress and mitophagy pathways,and enhanced intercellular structures related to tight junctions and adherent junctions.Furthermore,quadratic regression analysis of the PWG and intestinal reactive oxygen species content indicated that the optimal addition level of D-mannose for juvenile grass carp was 4.61 and 4.59 g/kg,respectively.展开更多
Fumonisin B1(FB1)is a prevalent mycotoxin found in plant-based feed ingredients,and it negatively impacts the performance of aquatic animals.However,the mechanism of this toxicity remains unclear.This study aims to in...Fumonisin B1(FB1)is a prevalent mycotoxin found in plant-based feed ingredients,and it negatively impacts the performance of aquatic animals.However,the mechanism of this toxicity remains unclear.This study aims to investigate the effect and underlying mechanism of dietary FB1 on the growth performance of juvenile grass carp(Ctenopharyngodon idella).A total of 720 juvenile grass carp(10.92±0.02 g)were fed with four different levels of FB1 diets(0,2.06,3.94,and 8.05 mg/kg)for 30 d and each group had 3 replicates of 60 fish.Our data indicated that when the FB1 concentration in the diet exceeded 3.94 mg/kg,there was a significant decline in growth performance(e.g.,final body weight,percent weight gain,and body length)(P<0.05),as well as reductions in the activities of digestive enzymes(e.g.,chymotrypsin and trypsin),alkaline phosphatase,and creatine kinase in juvenile grass carp(P<0.05).Furthermore,increased levels of intestinal sphinganine(Sa),sphingosine(So),and FB1 residues were observed,along with disruptions in intestinal tissue structure and elevated serum D-lactic acid levels(P<0.05).Additionally,FB1 inhibited the Kelch-like ECH-associated protein 1a/NF-E2-related factor-2 signaling pathway,resulting in decreased gene expression of intestinal copper-zinc superoxide dismutase,glutathione peroxidase 4b,and glutathione peroxidase 1a(P<0.05).These alterations were accompanied by a reduction in glutathione levels,total superoxide dismutase activity,and total antioxidant capacity(P<0.05),as well as an increase in levels of reactive oxygen species and malondialdehyde in the intestine(P<0.05).FB1 induced intestinal apoptosis by downregulating the gene expression of B-cell lymphoma 2(P=0.009),while simultaneously upregulating the expression of Bcl-2-associated X protein,apoptotic protease activating factor-1,caspase-9,and caspase-3(P<0.05).Additionally,FB1 decreased the gene expression of apical junction complex-related molecules(e.g.,zonula occluden-1,occludin,and nectin)(P<0.05),while increasing the expression of claudin-15b,myosin light chain kinase,Rho family GTPases,and Rho-associated protein kinase(P<0.05).These findings indicated that dietary FB1 negatively impacts the growth performance of juvenile grass carp,likely due to reduced digestive and absorptive capacities,elevated intestinal Sa and So levels,and disruption of intestinal structure integrity.This study filled the study gap on the toxicity of FB1 to the intestines of aquatic animals.展开更多
基金supported by the earmarked fund for CARS (CARS-45),and the National Key R&D Program of China (2019YFD0900200).
文摘D-mannose,essential for protein glycosylation,has been reported to have immunomodulatory effects and to maintain intestinal flora homeostasis.In addition to evaluating growth performance,we examined the impact of D-mannose on the structure of epithelial cells and apical junction complexes in the animal intestine.All 1800 grass carp(16.20±0.01 g)were randomly divided into six treatments with six replicates of 50 fish each and fed with six different levels of D-mannose(0.52,1.75,3.02,4.28,5.50 and 6.78 g/kg diet)for 70 d.The study revealed that D-mannose increased feed intake(P 0.05).D-mannose supplementation at 1.75 g/kg increased crude protein content in fish and lipid production value(P<0.05).D-mannose supplementation at 4.28 g/kg increased intestinal length,intestinal weight and fold height of grass carp compared to the control group(P<0.05).This improvement may be attributed to the phosphomannose isomerase(PMI)-mediated enhancement of glycolysis.This study found that D-mannose supplementation at 4.28 or 3.02 g/kg reduced serum diamine oxidase activity or D-lactate content(P<0.05)and improved cellular and intercellular structures for the first time.The improvement of cellular redox homeostasis involves alleviating endoplasmic reticulum(ER)stress through the inositol-requiring enzyme 1(IRE1),RNA-dependent protein kinase-like ER kinase(PERK),and activating transcription factor 6(ATF6)signaling pathways.The alleviation of ER stress may be linked to the phosphomannomutase(PMM)-mediated enhancement of protein glycosylation.In addition,ubiquitin-dependent[PTEN-induced putative kinase 1(PINK1)/Parkin]and ubiquitin-independent[BCL2-interacting protein 3-like(BNIP3L),BCL2-interacting protein 3(BNIP3),and FUN14 domain containing 1(FUNDC1)]mitophagy may play a role in maintaining cellular redox homeostasis.The enhancement of intercellular structures includes enhancing tight junction and adherent junction structures,which may be closely associated with the small Rho GTPase protein(RhoA)/the Rho-associated protein kinase(ROCK)signaling pathway.In conclusion,D-mannose improved intestinal cellular redox homeostasis associated with ER stress and mitophagy pathways,and enhanced intercellular structures related to tight junctions and adherent junctions.Furthermore,quadratic regression analysis of the PWG and intestinal reactive oxygen species content indicated that the optimal addition level of D-mannose for juvenile grass carp was 4.61 and 4.59 g/kg,respectively.
基金supported by the National Key R&D Program of China(2023YFD2400600)the earmarked fund for CARS(CARS-45)the 111 project(D17015).
文摘Fumonisin B1(FB1)is a prevalent mycotoxin found in plant-based feed ingredients,and it negatively impacts the performance of aquatic animals.However,the mechanism of this toxicity remains unclear.This study aims to investigate the effect and underlying mechanism of dietary FB1 on the growth performance of juvenile grass carp(Ctenopharyngodon idella).A total of 720 juvenile grass carp(10.92±0.02 g)were fed with four different levels of FB1 diets(0,2.06,3.94,and 8.05 mg/kg)for 30 d and each group had 3 replicates of 60 fish.Our data indicated that when the FB1 concentration in the diet exceeded 3.94 mg/kg,there was a significant decline in growth performance(e.g.,final body weight,percent weight gain,and body length)(P<0.05),as well as reductions in the activities of digestive enzymes(e.g.,chymotrypsin and trypsin),alkaline phosphatase,and creatine kinase in juvenile grass carp(P<0.05).Furthermore,increased levels of intestinal sphinganine(Sa),sphingosine(So),and FB1 residues were observed,along with disruptions in intestinal tissue structure and elevated serum D-lactic acid levels(P<0.05).Additionally,FB1 inhibited the Kelch-like ECH-associated protein 1a/NF-E2-related factor-2 signaling pathway,resulting in decreased gene expression of intestinal copper-zinc superoxide dismutase,glutathione peroxidase 4b,and glutathione peroxidase 1a(P<0.05).These alterations were accompanied by a reduction in glutathione levels,total superoxide dismutase activity,and total antioxidant capacity(P<0.05),as well as an increase in levels of reactive oxygen species and malondialdehyde in the intestine(P<0.05).FB1 induced intestinal apoptosis by downregulating the gene expression of B-cell lymphoma 2(P=0.009),while simultaneously upregulating the expression of Bcl-2-associated X protein,apoptotic protease activating factor-1,caspase-9,and caspase-3(P<0.05).Additionally,FB1 decreased the gene expression of apical junction complex-related molecules(e.g.,zonula occluden-1,occludin,and nectin)(P<0.05),while increasing the expression of claudin-15b,myosin light chain kinase,Rho family GTPases,and Rho-associated protein kinase(P<0.05).These findings indicated that dietary FB1 negatively impacts the growth performance of juvenile grass carp,likely due to reduced digestive and absorptive capacities,elevated intestinal Sa and So levels,and disruption of intestinal structure integrity.This study filled the study gap on the toxicity of FB1 to the intestines of aquatic animals.
