Berberine regulates glucose metabolism in largemouth bass by modulating intestinal microbiota

This study examined the role of intestinal microbiota in berberine (BBR)-mediated glucose (GLU) metabolism regulation in largemouth bass. Four groups of largemouth bass (133.7 ± 1.43 g) were fed with control diet, BBR (1 g/kg feed) supplemented diet, antibiotic (ATB, 0.9 g/kg feed) supplemented diet and BBR + ATB (1g/kg feed +0.9 g/kg feed) supplemented diet for 50 days. BBR improved growth, decreased the hepatosomatic and visceral weight indices, significantly downregulated the serum total cholesterol and GLU levels, and significantly upregulated the serum total bile acid (TBA) levels. The hepatic hexokinase, pyruvate kinase, GLU-6-phosphatase and glutamic oxalacetic transaminase activities in the largemouth bass were significantly upregulated when compared with those in the control group. The ATB group exhibited significantly decreased final bodyweight, weight gain, specific growth rates and serum TBA levels, and significantly increased hepatosomatic and viscera weight indices, hepatic phosphoenolpyruvate carboxykinase, phosphofructokinase, and pyruvate carboxylase activities, and serum GLU levels. Meanwhile, the BBR + ATB group exhibited significantly decreased final weight, weight gain and specific growth rates, and TBA levels and significantly increased hepatosomatic and viscera weight indices and GLU levels. High-throughput sequencing revealed that compared with those in the control group, the Chao one index and Bacteroidota contents were significantly upregulated and the Firmicutes contents were downregulated in the BBR group. Additionally, the Shannon and Simpson indices and Bacteroidota levels were significantly downregulated, whereas the Firmicutes levels were significantly upregulated in ATB and BBR + ATB groups. The results of in-vitro culture of intestinal microbiota revealed that BBR significantly increased the number of culturable bacteria. The characteristic bacterium in the BBR group was Enterobacter cloacae. Biochemical identification analysis revealed that E. cloacae metabolizes carbohydrates. The size and degree of vacuolation of the hepatocytes in the control, ATB, and ATB + BBR groups were higher than those in the BBR group. Additionally, BBR decreased the number of nuclei at the edges and the distribution of lipids in the liver tissue. Collectively, BBR reduced the blood GLU level and improved GLU metabolism in largemouth bass. Comparative analysis of experiments with ATB and BBR supplementation revealed that BBR regulated GLU metabolism in largemouth bass by modulating intestinal microbiota.

[Association of extranodal extension and lymph node ratio with radioactive iodine-refractory papillary thyroid cancer]

Objective: To investigate the related factors of radioiodine-refractory thyroid cancer (RAIR-DTC) and the increase of cumulative iodine treatment dose. Methods: The data of patients with papillary thyroid cancer who underwent surgery and iodine treatment for the first time in the Affiliated Cancer Hospital of Zhengzhou University from January 2015 to December 2017 were retrospectively analyzed. The related factors of RAIR-DTC and the increase of cumulative iodine treatment dose were explored. Results: A total of 650 patients were enrolled, including 217 males (33.4%) and 433 females (66.6%), aged 45 (34, 53) years. There were 123 patients (18.9%) over 55 years old, 171 patients (26.3%) with extranodal extension and 18 patients (2.8%) with distant metastasis. The median lymph node ratio was 0.22 (0.11, 0.33). Twenty patients (3.1%) had an accumulated iodine treatment dose>400 mCi and 19 patients (2.9%) had RAIR-DTC. Multivariate logistic regression analysis showed that extranodal extension (OR=19.833, 95%CI: 6.057-73.325, P<0.001) was related factors for the increase of cumulative iodine treatment dose. Age>55 years old (OR=3.322, 95%CI: 1.136-9.466, P=0.024), distant metastasis (OR=10.059, 95%CI: 2.508-38.888, P<0.001), extranodal extension (OR=5.278, 95%CI: 1.707-19.813, P=0.006) and lymph node ratio (OR=34.724, 95%CI: 2.749-384.575, P=0.004) were related factors for RAIR-DTC. Conclusions: Extranodal extension and lymph node ratio are related factors for RAIR-DTC. In clinical practice, more attention should be paid to the influence of different lymph node metastasis characteristics on the occurrence of RAIR-DTC and the cumulative therapeutic dose of iodine.

Identification and analysis of lipid droplet-related proteome in the adipose tissue of grass carp (Ctenopharyngodon idella) under fed and starved conditions

Fat accumulation in the mesenteric adipose tissue is a serious problem in grass carp (Ctenopharyngodon idella) culture. Lipid droplet-related proteins (LDRPs) are involved in the formation, degradation, and biological functions of lipid droplets. In this study, we aimed to provide reference proteomics data to study lipid droplet regulation in fish. We isolated LDRPs from the mesenteric adipose tissue of grass carp (1-year-old) after normal feeding and 7 days of starvation, and identified and analysed them using isobaric tags for relative and absolute quantitation (iTRAQ) technology. Short-term starvation had no significant effect on the body weight, condition factor, visceral index, hepatopancreas index, intraperitoneal fat index, adipose tissue triglyceride content, and adipocyte size of grass carp. Nine hundred and fifty proteins were identified and annotated using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases; they are involved in a variety of metabolic and signalling pathways, including amino acid, lipid, and carbohydrate metabolism, and the PI3K-Akt signalling pathway. There were 296 differentially expressed proteins (DEPs), with 143 up-regulated and 153 down-regulated proteins. Three proteins involved in triglyceride and fatty acid syntheses and two proteins involved in autophagy were up-regulated, and six proteins involved in lipid catabolism were down-regulated. These results indicate that under short-term starvation, lipid droplets in the adipose tissue of grass carp may maintain their shape by promoting fat production and inhibiting lipolysis, and autophagy may be one of the main strategies for coping with short-term energy deprivation.

Lipid droplets participate in modulating innate immune genes in Ctenopharyngodon idella kidney cells

Lipid droplets (LDs) are increasingly being recognized as important immune modulators in mammals, in additional to their function of lipid ester deposition. However, the role of LDs in fish immunity remains poorly understood. In this study, the function of LDs in the innate immune response of Ctenopharyngodon idella kidney (CIK) cells, which are the equivalent of myeloid cells in vertebrates, was investigated. LD number and TG content significantly increased in the CIK cells following exposure to lipopolysaccharide (LPS), peptidoglycan (PGN), and polyriboinosinic-polyribocytidylic acid (Poly [I: C]) for 24 h, accompanied by increases in the relative expression of several innate immune genes. However, fatty acid compositions of the triglycerides were not changed after treatment with these three pathogenic mimics. LPS, PGN, and Poly (I: C) did not alter the relative expressions of lipogenic (FAS, SCD, and DGAT) and lipid catabolic (PPARα, ATGL, and CPT-1) genes. However, these treatments did increase the mRNA levels of lipid transportation genes (FATP/CD36, ACSL1, and ACSL4), and also decreased the non-esterified fatty acid level in the medium. To further explore the role of LDs in the immune response, CIK cells were incubated with different concentrations (0, 100, 200, 300, 400, 500 μM) of exogenous lipid mix (LM; oleic acid [OA]:linoleic acid [LA]:linolenic acid [LNA] = 2:1:1), and were then transferred to a lipid-free medium and incubated for 24 h. LD size and number increased with the increase in lipid levels, and this was accompanied by increased expression of innate immune genes, including MyD88, IRF3, and IL-1β, which were expressed at their highest levels in 300 μM exogenous lipid mix. Interestingly, after incubating with different fatty acids (LM, OA, LA, LNA, arachidonic acid [ARA], and docosahexaenoic acid [DHA]; 300 μM), ARA and DHA were more potent in inducing LD formation and innate immune gene expression in the CIK cells. Finally, atglistatin, an ATGL inhibitor, effectively attenuated the expression of most genes upregulated by ARA or DHA, suggesting that lipolysis may be involved in the regulation of immune genes at the transcriptional level. Overall, the findings of this study demonstrate that LDs are functional organelles that could act as modulators in the innate immune response of CIK cells. Additionally, long-chain polyunsaturated fatty acid enriched LDs play a unique role in regulating this process.

Lipid accumulation in grass carp (Ctenopharyngodon idellus) fed faba beans (Vicia faba L.)

Feeding faba beans (Vicia faba L.) to grass carp (Ctenopharyngodon idellus) increases muscle compactness but decreases growth and motility. The lipid metabolism of grass carp was examined to assess potential effects of feeding faba beans on physiological properties using a total of 180 fish. The treatment group was fed faba beans for 120 days and a commercial diet for another 30 days. The control group received a commercial diet for 150 days. Fish were sampled every month. Weight gain was significantly lower in the treatment group than in the control. Hardness, springiness, chewiness, cohesiveness, and gumminess of the dorsal muscle increased significantly with the feeding faba beans from 30 to 120 days, which was not reversed by the subsequent feeding of commercial diet. Fat accumulation increased significantly in the treatment group as suggested by the condition factor, viscera index, hepatopancreatic index, and intraperitoneal fat index (IPFI), hepatopancreas, and muscle fat content but was not affected by subsequent feeding with the commercial diet. Serum triglyceride and total cholesterol levels were significantly reduced in the experimental diet group. In the hepatopancreas and intraperitoneal fat IPF, monounsaturated fatty acids showed significantly higher content in faba bean feeding fish, whereas polyunsaturated fatty acid content showed the reversed pattern. In the hepatopancreas, the activities of the lipogenic enzymes malate dehydrogenase and glucose 6-phosphate dehydrogenase were higher in the treatment than in the control group. Moreover, the treatment group showed lower mRNA levels of carnitine palmitoyltransferase-1. Overall, our results clearly demonstrate increasing lipid accumulation in the viscera of faba bean-fed grass carp.

Smad4-dependent regulation of type I collagen expression in the muscle of grass carp fed with faba bean

Smad4 is the key regulator in the transforming growth factor β1 (TGF-β1)/Smads signal pathway, and is also the crux of the regulation of type I collagen expression in mammals. In fish, however, the relationship between Smad4 and type I collagen is still unknown. Given the widely accepted importance of type I collagen in fish muscle hardness, we seek to explore this issue by analyzing the expressions of the TGF-β1/Smads pathway molecules and type I collagen in the muscle of crisp grass carp fed with faba bean, which shows increased muscle hardness. The study found that (1) in the process of feeding the grass carp with faba bean, the mRNA and protein expressions of TGF-β1, Smad2 and Smad4 all increased along with the increase of type I collagen expression (Col1α1 and Col1α2); (2) one day after the injection of Smad4 over-expression vector, both mRNA and protein expressions of Col1α1 and Col1α2 significantly increased, reaching the maximum on the 2nd and 5th day, respectively; (3) one day after the injection of Smad4 RNAi interference vector, the mRNA and protein expressions of Col1α1 and Col1α2 decreased, reaching the minimum on the 5th day. These results revealed that Smad4 is the major regulator of type I collagen in the muscle of grass carp fed with faba bean. This study would provide an important mechanistic basis for nutritional regulation of type I collagen in the muscle of fish.

Crystallization and preliminary crystallographic studies of antibacterial polypeptide LCI expressed in Escherichia coli

LCI is a type of novel antibacterial polypeptide secreted by a Bacillus subtilis strain. It consists of 47 residues with a molecular weight of 5468 Da. Using bioengineering, LCI was expressed in Escherichia coli DH5alpha with recombinant plasmid pBVAB16. It was crystallized using PEG 4000 as a precipitant. The crystal belongs to space group P6(2)22 or P6(4)22, with unit-cell parameters a = b = 29.30, c = 187.09 A, and diffracts to 2.44 A. A set of diffraction data to 2.8 A was collected.