Effects of cysteine addition to low-fishmeal diets on the growth, anti-oxidative stress, intestine immunity, and Streptococcus agalactiae resistance in juvenile golden pompano (Trachinotus ovatus).

As the precursor of taurine, cysteine serves physiological functions, such as anti-oxidative stress and immune improvement. Investigation of cysteine and its derivatives has made positive progress in avian and mammalian species, yet the study and application of cysteine in aquatic animals are relatively rare. Therefore, we evaluated the effects of supplementing a low-fishmeal diet with various levels of cysteine on the growth, antioxidant capacity, intestine immunity, and resistance against Streptococcus agalactiae of the juvenile golden pompano (Trachinotus ovatus). According to our study, exogenous supplementation with 0.6-1.2% cysteine greatly increased the final body weight (FBW) and specific growth rate (SGR) of golden pompano compared to the control group. Under the present conditions, the optimum dietary cysteine supplementation level for golden pompano was 0.91% based on the polynomial regression analysis of SGR. Meanwhile, we found that the Nrf2/Keap1/HO-1 signaling pathway was notably upregulated with the increase of exogenous cysteine, which increased antioxidant enzyme activity in serum and gene expression in the intestine and reduced the level of reactive oxygen species (ROS) in the serum of golden pompano. In addition, morphological analysis of the midgut demonstrated that exogenous cysteine improved muscle thickness and villi length, which suggested that the physical barrier of the intestine was greatly strengthened by cysteine. Moreover, cysteine increased the diversity and relative abundance of the intestinal flora of golden pompano. Cysteine suppressed intestinal NF-κB/IKK/IκB signaling and pro-inflammatory cytokine mRNA levels. Conversely, intestinal anti-inflammatory cytokine gene expression and serum immune parameters were upregulated with the supplementary volume of cysteine and improved intestine immunity. Further, exogenous cysteine supplementation greatly reduced the mortality rate of golden pompano challenged with S. agalactiae. In general, our findings provide more valuable information and new insights into the rational use of cysteine in the culture of healthy aquatic animals.

Effects of exogenous taurine supplementation on the growth, antioxidant capacity, intestine immunity, and resistance against Streptococcus agalactiae in juvenile golden pompano (Trachinotus ovatus) fed with a low-fishmeal diet.

Taurine has various biological functions in fish, playing an essential role in growth, resistance to oxidative stress, and intestine immunity. Here, we evaluated the effects of exogenous taurine added to low-fishmeal diets on the growth, anti-oxidative stress, intestine immunity, and Streptococcus agalactiae resistance in juvenile golden pompano (Trachinotus ovatus). Our study showed that exogenous taurine supplementation of 1.2% (T3 group) greatly enhanced the weight gain rate and specific growth rate (SGR) of juvenile golden pompano, significantly upregulating growth-related factor expression in the brain and liver, as well as the levels of growth-related parameters in the serum. Polynomial regression analysis using SGR estimated the optimal dietary taurine level for golden pompano at 1.18%. Moderate exogenous taurine also increased the muscular thickness and villus length within the intestine, maintained intestinal physical barrier stability, activated the Nrf2/Keap-1/HO-1 signaling pathway, increased intestinal antioxidant enzyme gene expression and antioxidant enzyme activity in the serum, and upregulated immunoglobulin and complement levels in parallel with declining reactive oxygen species (ROS) levels in the serum. Antioxidant factor expression was also upregulated in the intestine. Furthermore, supplementation suppressed NF-κB signaling and intestinal pro-inflammatory cytokine gene expression, increased anti-inflammatory cytokine gene expression, and improved intestine immunity. Finally, taurine supplementation improved the survival rate of golden pompano challenged with S. agalactiae. Overall, our findings provide additional information and support for the rational use of taurine in healthy aquatic animal farming.

[Metabonomic study of biochemical changes in serum of PCPA-induced insomnia rats after treatment with Suanzaoren Decoction].

Suanzaoren Decoction(SZRD) is a classical formula for the clinical treatment of insomnia. This study analyzed the effect of SZRD on endogenous metabolites in insomnia rats based on metabonomics and thereby explored the anti-insomnia mechanism of SZRD. To be specific, DL-4-chlorophenylalanine(PCPA) was used to induce insomnia in rats. Then pathological changes of the liver and brain were observed and biochemical indexes such as 5-hydroxytryptamine(5-HT), dopamine(DA), glutamate(Glu), γ-aminobutyric acid(GABA), and norepinephrine(NE) in the hippocampus and prostaglandin D2(PGD2), tumor necrosis factor-α(TNF-α), interleukin-1ß(IL-1ß), and IL-6 in the serum of rats were detected. On this basis, the effect of SZRD on PCPA-induced insomnia rats was preliminarily assessed. The metabolic profile of rat serum samples was further analyzed by ultra-performance liquid chromatography-quadrupole-time of flight-tandem mass spectrometry(UPLC-Q-TOF-MS/MS). Principal component analysis(PCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA) were combined with t-test and variable importance in projection(VIP) to identify differential metabolites, and MetaboAnalyst 5.0 was employed for pathway analysis. The results showed that SZRD could improve the pathological changes of brain and liver tissues, increase the levels of neurotransmitters 5-HT, DA, and GABA in hippocampus and the level of PGD2 in hypothalamic-pituitary-adrenal axis(HPA axis), and reduce the levels of IL-1ß and TNF-α in serum of insomnia rats. Metabonomics analysis yielded 12 significantly changed potential metabolites: 5-aminovaleric acid, N-acetylvaline, L-proline, L-glutamate, L-valine, DL-norvaline, D(-)-arginine, pyroglutamic acid, 1-methylguanine, L-isoleucine, 7-ethoxy-4-methylcoumarin, and phthalic acid mono-2-ethylhexyl ester(MEHP), which were related with multiple biochemical processes including metabolism of D-glutamine and D-glutamate, metabolism of alanine, aspartate, and glutamate, metabolism of arginine and proline, arginine biosynthesis, glutathione metabolism. These metabolic changes indicated that SZRD can improve the metabolism in insomnia rats by regulating amino acid metabolism.

[Mechanism of Suanzaoren Decoction in improving insomnia rats by integrating metabolomics and intestinal flora analysis].

To explore the mechanism of Suanzaoren Decoction(SZRD) in improving the insomnia rat model induced by DL-4-chlorophenylalanine(PCPA). The insomnia model was established by single intraperitoneal injection with PCPA(400 mg·kg~(-1)), UPLC-Q-TOF-MS/MS was used to analyze the profile of metabolites in rat hippocampus samples, combined with multivariate statistical analysis and screening of differential metabolites, and related metabolic pathways were constructed with MetaboAnalyst 5.0. The high-throughput sequencing of V3-V4 regions of 16 S rRNA gene was used to predict the structure and relative abundance of intestinal flora by LEfSe, OPLS-DA and PICRUSt2. A total of 22 differential hippocampus metabolites were identified by metabolomics analysis, including amino acids, fatty acids, nucleosides, organic acids, vitamins, and others. Pathway analysis showed that alanine, aspartate and glutamic metabolism, D-glutamine and D-glutamate metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, arginine biosynthesis were the main pathways. 16 S rRNA gene sequencing showed that Ruminococcus and Eubacterium were the differences between SZRD group and model group. Ruminococcus might be the sign of SZRD improving PCPA insomnia on analysis of PICRUSt2 and LEfSe. Furthermore Spearman correlation analysis showed that the differential metabolites 2-oxo-4-methylthiobutyric acid and palmitic acid intervened by SZRD were significantly positively correlated with the differential flora. In conclusion, SZRD indirectly improves insomnia by affecting metabolic pathways such as amino acids metabolic pathways and regulating the structure of flora. The results of this study provide a new mechanism and new idea for elucidating the mechanism of classic famous prescription SZRD in improving insomnia from the perspective of intestinal flora.

Stimulation of osteogenic differentiation in bone marrow stromal cells via Wnt/ß-catenin pathway by Qili Jiegu-containing serum.

A capsule of Qili Jiegu, a traditional Chinese medicine with numerous biological activities, may exert a protective eff ;ect against postmenopausal bone loss. However, it remains unclear whether Qili Jiegu-containing serum regulates the osteogenic diff ;erentiation of bone marrow stromal cells (BMSCs) in vitro. In this study, BMSCs were treated with medium and Qili Jiegu-containing serum over a 14-day period. We found that Qili Jiegu-containing serum promoted the BMSC proliferation and alkaline phosphatase (ALP) activities, as well as stimulated the expression of osteogenic markers and Wnt/ß-catenin pathway-related genes, i.e., runt-related transcription factor 2 (Runx2), osteocalcin (OCN), ß-catenin and Wnt4a, in BMSCs. Finally, we found that Qili Jiegu-containing serum activated the Wnt/ß-catenin pathway. An addition of Dickkopf-related protein-1 (an inhibitor of the Wnt/ß-catenin signaling pathway) to the Qili Jiegu-containing serum could decrease the stimulatory osteogenic effect of Qili Jiegu-containing serum on BMSCs. Therefore, Qili Jiegu-containing serum could promote the osteogenic diff ;erentiation of BMSCs, and the potential mechanism may involve regulation of Wnt/ß-catenin signaling.