Protective effect of L-pipecolic acid on constipation in C57BL/6 mice based on gut microbiome and serum metabolomic.

BACKGROUND: Functional constipation (FC) in children affects their growth, development and quality of life. L-pipecolic acid (L-PA) was decreased in FC children based on gut microbiome and serum metabolomic. In this study, loperamide-induced constipation in mice was used to evaluate the effects of L-PA on constipated mice. METHOD: 26 FC and 28 healthy children were recruited. Stool samples and serum samples were subjected to 16S rDNA sequencing and ultra-performance liquid chromatography/quadrupole time of flight (UPLC-Q/TOF-MS) approach, respectively. A loperamide-induced mouse constipation model was developed, and all mice were randomly divided into control (Con), loperamide (Lop) and L-PA (Lop + L-PA) treatment groups (6 mice per group). The mice in the Lop + L-PA group were given L-PA (250 mg/kg, once a day) and loperamide; the Lop group was given loperamide for 1 week, and the Con group was given saline. The fecal parameters and intestinal motility of mice in each group were detected. serum 5-HT levels and colon 5-HT expression were detected by ELISA and immunohistochemistry, respectively; qRT-PCR was used to detect the expression of AQP3 and 5-HT4R mRNA in each group. RESULTS: 45 differential metabolites and 18 significantly different microbiota were found in FC children. The α and ß diversity of gut microbiota in FC children was significantly reduced. Importantly, serum L-PA was significantly reduced in FC children. The KEGG pathway enrichment were mainly enriched in fatty acid biosynthesis, lysine degradation, and choline metabolism. L-PA was negatively associated with Ochrobactrum, and N6, N6, N6-trimethyl-l-lysine was positively associated with Phascolarcrobacterium. In addition, L-PA improved the fecal water content, intestinal transit rate, and increased the serum 5-HT levels in constipated mice. Moreover, L-PA increased the expression of 5-HT4R, reduced AQP3, and regulated constipation-associated genes. CONCLUSIONS: Gut microbiota and serum metabolites were significantly altered in children with FC. The abundance of Phascolarctobacterium and Ochrobactrum and serum L-PA content were decreased in FC children. L-PA was found to alleviate the fecal water content, increase intestinal transit rate and the first black stool defecation time. L-PA improved constipation by increasing 5-HT and 5-HT4R expression while down-regulating AQP3 expression.

Serum sCD14 as a Biomarker for Significant Liver Inflammation in Chronic Hepatitis B Patients with Normal or Mildly Elevated ALT.

BACKGROUND: CD14 is a pattern recognition receptor constitutively expressed in different types of immune cells, either in a membrane-anchored (mCD14) or in a soluble (sCD14) form. This study investigated whether hepatic CD14 expression levels were correlated with the grades of liver inflammation as well as the potential usefulness of serum sCD14 as a biomarker for predicting liver inflammation in chronic hepatitis B (CHB) patients with normal or mildly elevated ALT. METHODS: A total of 216 treatment-naive CHB patients with normal or mildly elevated ALT who underwent liver biopsy were recruited. Hepatic expression level of CD14 was measured using immunohistochemistry and real-time PCR. Serum sCD14 concentrations were determined with an enzyme-linked immunosorbent assay. Correlations between hepatic CD14, serum sCD14, and liver inflammation grade were analyzed. Univariate and multivariate analysis were performed to identify significant liver inflammation-associated factors. The receiver operating characteristic curve was used to assess the discriminating power of serum sCD14 to significant liver inflammation in CHB patients with normal or mildly elevated ALT. RESULTS: Both hepatic expression levels of CD14 and serum sCD14 concentrations significantly increased with the aggravation of liver inflammation. Moreover, hepatic expression levels of CD14, serum sCD14 concentrations, and liver inflammation grades were positively correlated with each other. Three parameters including alkaline phosphatase (ALP), neutrophil, and sCD14 were identified as independent predictors of significant liver inflammation. Subsequently, a diagnostic equation named model-sCD14 was developed incorporating sCD14 and other variables (ALP and neutrophils) with p < 0.05 in multivariate logistic analysis. The area under receiver operating characteristic curve (AUC) of sCD14 for predicting significant liver inflammation was 0.788 and the optimal cutoff was 27.14 ng/mL, with a sensitivity of 66.67%, a specificity of 81.70%, positive predictive value of 60.01%, and negative predictive value of 85.62%. When sCD14 was replaced by model-sCD14, the AUC value increased from 0.788 to 0.843 (z = 2.311, p = 0.021), with sensitivity of 77.78%, specificity of 77.12%, positive predictive value of 58.33%, and negative predictive value of 89.39%. CONCLUSIONS: Serum sCD4 has the potential to discriminate significant liver inflammation from CHB patients with normal or mildly increased ALT levels.

Antifungal Effects of Fusion Puroindoline B on the Surface and Intracellular Environment of Aspergillus flavus.

Aspergillus flavus infection is a major issue for safe food storage. In this study, we constructed an efficient prokaryotic expression system for puroindoline B (PINB) protein to detect its antifungal activity. The Puroindoline b gene was cloned into pET-28a (+) vector and expressed in Escherichia coli. Treatment with fusion PINB revealed that it inhibits mycelial growth of A. flavus, a common grain mold. Moreover, fusion PINB-treated A. flavus mycelium withered and exhibited a sunken spore head. As fusion PINB concentration increased, electrical conductivity in mycelium also increased, indicative of cell membrane damage. Furthermore, intracellular malate dehydrogenase and succinate dehydrogenase activity decreased, revealing a disruption in the tricarboxylic acid cycle. Moreover, the dampened activity of the ion pump Na+K+-ATPase negatively affected the intracellular regulation of both ions. Catalase and superoxide dismutase activity decreased, thus reducing antioxidant capacity, a result confirmed with an increase in malondialdehyde content. Changes to the GSH/GSSG ratio indicated a shift to an intracellular oxidative state. At the same time, laser scanning confocal microscopy assay showed the accumulation of reactive oxygen species and nuclear damage. Therefore, the PINB fusion protein may have the potential to control A. flavus in grain storage and food preservation.

[Spectral Characteristics and Source Analysis of WSOC of PM2.5 in Winter of Xi'an].

The spectral characteristics and sources of water-soluble organic compounds (WSOC) in PM2.5 in winter were studied by using UV-vis absorption spectroscopy, three-dimensional fluorescence spectroscopy, parallel factor analysis, and backward trajectory model. The results showed that the concentration of WSOC in PM2.5 was 4.66-14.75 µg ·m-3. The values of E2/E3, E3/E4, S275-295, SUVA254, AAE, and MAE365 of WSOC were, respectively, in the range of 2.85-4.32, 2.21-3.56, 0.0099-0.0127 nm-1, 2.35-3.89 m2 ·g-1, 2.66-4.60, and 1.51-2.60 m2 ·g-1. The E2/E3, E3/E4, S275-295, and AAE values of WSOC at the sampling site in the southern suburb of Xi'an, China (Xi'an University of Architecture and Technology) were higher than those at the sampling site in the northern suburb (sports park), while the values of SUVA254 and MAE365 were lower. There were four fluorescent components in WSOC identified by the EEMs-PARAFAC model: C1 and C2 were fulvic acid-like and protein-like, respectively, and C3 and C4 were humus-like components. The fluorescence intensities and the sum of the fluorescent components were positively correlated with the concentrations of PM2.5, OC, WSOC, and A254 value (P<0.01). The fluorescence index (FI), biological source index (BIX), and humic index (HIX) values of WSOC were 1.75-2.12, 1.14-1.46, and 1.18-2.06, respectively. During the monitoring period, the air mass transmission trajectory was dominated by the local southwest of short-distance transmission, and its trajectory accounted for more than 50%. The pollutant emissions from Xinjiang, Inner Mongolia, and Gansu also made significant contributions to the air pollution levels in Xi'an in winter. There was a small difference in the carbon component content of PM2.5 in the northern and southern suburbs of Xi'an. The molecular weight, humification degree, and light absorption capacity of WSOC at the southern suburb sampling site were lower than those in the northern suburb where the wavelength dependence of light absorption intensity was relatively stronger. The WSOC mainly originated from biological sources or both from biological and terrestrial sources. Local transmission had the most significant contribution to PM2.5 and WSOC in winter.

[Effect of salvianolic acid B on high-glucose induced renal tubular epithelial-mesenchymal transition in rats and its mechanism].

The aim of this paper was to observe the effect of salvianolic acid B(Sal B) on high-glucose induced renal tubular epithelial-mesenchymal transition(EMT) in rats, and to explore its possible mechanisms of prevention and treatment of diabetic nephropathy. The rat renal tubular epithelial NRK-52 E cells were cultured in vitro. The cells were divided into control group, high glucose group, high glucose+10 µmol·L~(-1)Sal B group(Sal B), the above 3 groups were set at 6, 12, 24 and 48 h for dynamic observation; high glucose+Sal B different concentration(1, 5, 10 µmol·L~(-1)) groups, high glucose+5.0 µmol·L~(-1) pioglitazone group, high glucose+10 µmol·L~(-1)Sal B+5 µmol·L~(-1)GW9662 group. The protein expression levels of PPARγ, PTEN, α-SMA, E-cadherin and PI3 K/Akt signaling molecules were determined by Western blot. The mRNA expression of PPARγ and PTEN were detected by Real-time PCR. The viabi-lity of NRK52 E cells was determined by MTT assay. The results showed that as compared with control group, the mRNA and protein expression levels of PPARγ and PTEN in high glucose group gradually reduced, the protein expression levels of α-SMA and p-Akt~((Thr308))gradually increased, and the protein expression of E-cadherin gradually reduced(P<0.05). As compared with high glucose group, when increases in Sal B doses, the mRNA and protein expression levels of PPARγ, PTEN in high glucose + different concentrations of Sal B groups gradually increased, the protein expression levels of α-SMA and p-Akt~((Thr308)) gradually reduced, and the protein expression of E-cadherin gradually increased(P<0.05), however, the effect of 1 µmol·L~(-1)concentration of Sal B on the expression of PPARγ mRNA and protein and PTEN mRNA was not significantly different. As compared with high glucose group, the mRNA and protein expression levels of PPARγ mRNA(except 6 h) and protein(except 6 h), PTEN mRNA(except 6 h) and protein(except 6, 12 h) kept increasing, the protein expression levels of α-SMA and p-Akt~((Thr308))(except 6 h) continued to reduce, the protein expression of E-cadherin kept increasing in high glucose+10 µmol·L~(-1) Sal B dynamic observation group(P<0.05). As compared with high glucose group, Sal B and the pioglitazone(PIO) can greatly enhance the expression of PPARγ, PTEN at mRNA and protein levels, enhance the expression of E-cadherin at protein levels, and reduce the expression of α-SMA, p-Akt~((Thr308))protein level(P<0.05), there was no significant difference between the two groups. However, the expression levels of PPARγ and PTEN mRNA and protein, E-cadherin, α-SMA and p-Akt(Thr308) protein in the Sal B+GW9662 control group were not statistically significant compared with the high glucose group. The effect of Sal B was blocked by the PPARγ antagonist GW9662. It can be concluded that Sal B can suppress the NRK52 E cells induced by high-glucose EMT. The mechanism may be related to the activation of PPARγ with Sal B, and the up-regulation of PTEN expression, and thereby inhibiting the fibrosis effect of PI3 K/Akt signaling pathway.