The aim of this study was to examine whether flavin-containing monooxygenase (FMO) protein was expressed in cultured rat brain microvascular endothelial cells (BMECs), which constitute the blood-brain barrier (BBB), a...The aim of this study was to examine whether flavin-containing monooxygenase (FMO) protein was expressed in cultured rat brain microvascular endothelial cells (BMECs), which constitute the blood-brain barrier (BBB), and whether N-oxide from the tertiary amine, d-chlorpheniramine, was formed by FMO in rat BMECs. BMECs were isolated and cultured from the brains of three-week-old male Wistar rats. The expression of FMO1, FMO2 and FMO5 proteins was confirmed in rat BMECs by western blotting analysis using polyclonal anti-FMO antibodies, but FMO3 and FMO4 proteins were not found in the rat BBB. Moreover, N-oxide of d-chlorpheniramine was formed in rat BMECs. The intrinsic clearance value for N-oxidation at pH 8.4 was higher than that at pH 7.4. Inhibition of N-oxide formation by methimazole was found to be the best model of competitive inhibition yielding an apparent Ki value of 0.53 μmol/L, suggesting that N-oxidation was catalyzed by FMOs in rat BMECs. Although FMO activity in rat BMECs was lower than that in SD rat normal hepatocytes (rtNHeps), we suggest that rat BMECs enzymes can convert substrates of exogenous origin for detoxification, indicating that BMECs are an important barrier for metabolic products besides hepatic cells.展开更多
Background:Most duck eggs possess a fishy odor,indicating that ducks generally exhibit impaired trimethylamine(TMA)metabolism.TMA accumulation is responsible for this unpleasant odor,and TMA metabolism plays an essen-...Background:Most duck eggs possess a fishy odor,indicating that ducks generally exhibit impaired trimethylamine(TMA)metabolism.TMA accumulation is responsible for this unpleasant odor,and TMA metabolism plays an essen-tial role in trimethylaminuria(TMAU),also known as fish odor syndrome.In this study,we focused on the unusual TMA metabolism mechanism in ducks,and further explored the unclear reasons leading to the debilitating TMA metabolism.Methods:To achieve this,transcriptome,proteome,and metagenome analyses were first integrated based on the constructed duck populations with high and low TMA metabolism abilities.Additionally,further experiments were conducted to validate the hypothesis regarding the limited flavin-containing monooxygenase 3(FMO3)metabolism ability of ducks.Results:The study demonstrated that liver FMO3 and cecal microbes,including Akkermansia and Mucispirillum,par-ticipated in TMA metabolism in ducks.The limited oxidation ability of FMO3 explains the weakening of TMA metabo-lism in ducks.Nevertheless,it decreases lipid deposition and increases antibacterial activity,contributing to its survival and reproduction during the evolutionary adaptation process.Conclusions:This study demonstrated the function of FMO3 and intestinal microbes in regulating TMA metabolism and illustrated the biological significance of FMO3 impairment in ducks.展开更多
目的观察犬尿氨酸3单加氧酶(KMO)抑制剂对慢性脑低灌注大鼠模型认知功能的影响及其相关代谢产物变化情况。方法选取成年健康雄性SD大鼠45只,随机分成假手术组、手术组、抑制剂组,每组15只。手术组和抑制剂组行血管性认知障碍模型制备。...目的观察犬尿氨酸3单加氧酶(KMO)抑制剂对慢性脑低灌注大鼠模型认知功能的影响及其相关代谢产物变化情况。方法选取成年健康雄性SD大鼠45只,随机分成假手术组、手术组、抑制剂组,每组15只。手术组和抑制剂组行血管性认知障碍模型制备。假手术组和手术组生理盐水灌胃,抑制剂组KMO抑制剂灌胃。Western Blot检测血细胞及海马区脑组织KMO活性。结果与手术组比较,抑制剂组第1、2、4、5天逃避潜伏期时间明显缩短,平台象限游泳距离百分比明显升高(P<0.05)。与假手术组比较,手术组大鼠血细胞和海马区KMO活性明显升高(0.297±0.012 vs 0.147±0.017,0.880±0.029 vs 0.690±0.035,P<0.05);抑制剂组大鼠血细胞KMO活性明显低于手术组(0.177±0.023 vs 0.297±0.012,P<0.05)。与手术组比较,抑制剂组大鼠血清和海马区犬尿喹啉酸水平明显升高,大鼠血清KMO、3-羟基犬尿氨酸及血清和海马区喹啉酸水平明显降低,差异有统计学意义(P<0.05)。结论KMO抑制剂可改善血管性认知障碍大鼠的认知功能,机制可能是升高犬尿喹啉酸,降低喹啉酸实现的。展开更多
文摘The aim of this study was to examine whether flavin-containing monooxygenase (FMO) protein was expressed in cultured rat brain microvascular endothelial cells (BMECs), which constitute the blood-brain barrier (BBB), and whether N-oxide from the tertiary amine, d-chlorpheniramine, was formed by FMO in rat BMECs. BMECs were isolated and cultured from the brains of three-week-old male Wistar rats. The expression of FMO1, FMO2 and FMO5 proteins was confirmed in rat BMECs by western blotting analysis using polyclonal anti-FMO antibodies, but FMO3 and FMO4 proteins were not found in the rat BBB. Moreover, N-oxide of d-chlorpheniramine was formed in rat BMECs. The intrinsic clearance value for N-oxidation at pH 8.4 was higher than that at pH 7.4. Inhibition of N-oxide formation by methimazole was found to be the best model of competitive inhibition yielding an apparent Ki value of 0.53 μmol/L, suggesting that N-oxidation was catalyzed by FMOs in rat BMECs. Although FMO activity in rat BMECs was lower than that in SD rat normal hepatocytes (rtNHeps), we suggest that rat BMECs enzymes can convert substrates of exogenous origin for detoxification, indicating that BMECs are an important barrier for metabolic products besides hepatic cells.
基金supported by the National Natural Science Foundation of China(31672408)the China Agriculture Research Systems(CARS-40)+1 种基金the National Key Research and Development Program of China(2021YFD1200803)the Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R62).
文摘Background:Most duck eggs possess a fishy odor,indicating that ducks generally exhibit impaired trimethylamine(TMA)metabolism.TMA accumulation is responsible for this unpleasant odor,and TMA metabolism plays an essen-tial role in trimethylaminuria(TMAU),also known as fish odor syndrome.In this study,we focused on the unusual TMA metabolism mechanism in ducks,and further explored the unclear reasons leading to the debilitating TMA metabolism.Methods:To achieve this,transcriptome,proteome,and metagenome analyses were first integrated based on the constructed duck populations with high and low TMA metabolism abilities.Additionally,further experiments were conducted to validate the hypothesis regarding the limited flavin-containing monooxygenase 3(FMO3)metabolism ability of ducks.Results:The study demonstrated that liver FMO3 and cecal microbes,including Akkermansia and Mucispirillum,par-ticipated in TMA metabolism in ducks.The limited oxidation ability of FMO3 explains the weakening of TMA metabo-lism in ducks.Nevertheless,it decreases lipid deposition and increases antibacterial activity,contributing to its survival and reproduction during the evolutionary adaptation process.Conclusions:This study demonstrated the function of FMO3 and intestinal microbes in regulating TMA metabolism and illustrated the biological significance of FMO3 impairment in ducks.
文摘目的观察犬尿氨酸3单加氧酶(KMO)抑制剂对慢性脑低灌注大鼠模型认知功能的影响及其相关代谢产物变化情况。方法选取成年健康雄性SD大鼠45只,随机分成假手术组、手术组、抑制剂组,每组15只。手术组和抑制剂组行血管性认知障碍模型制备。假手术组和手术组生理盐水灌胃,抑制剂组KMO抑制剂灌胃。Western Blot检测血细胞及海马区脑组织KMO活性。结果与手术组比较,抑制剂组第1、2、4、5天逃避潜伏期时间明显缩短,平台象限游泳距离百分比明显升高(P<0.05)。与假手术组比较,手术组大鼠血细胞和海马区KMO活性明显升高(0.297±0.012 vs 0.147±0.017,0.880±0.029 vs 0.690±0.035,P<0.05);抑制剂组大鼠血细胞KMO活性明显低于手术组(0.177±0.023 vs 0.297±0.012,P<0.05)。与手术组比较,抑制剂组大鼠血清和海马区犬尿喹啉酸水平明显升高,大鼠血清KMO、3-羟基犬尿氨酸及血清和海马区喹啉酸水平明显降低,差异有统计学意义(P<0.05)。结论KMO抑制剂可改善血管性认知障碍大鼠的认知功能,机制可能是升高犬尿喹啉酸,降低喹啉酸实现的。
