MiR-20 promotes cartilage repair in knee osteoarthritis rats via BMP2/Smad1 signaling pathway.

To explore the effect of micro ribonucleic acid (miR)-20b on knee osteoarthritis rats by regulating the bone morphogenetic protein 2 (BMP2)/Smad1 pathway, a total of 36 SD rats were randomly divided into normal group (n=12), model group (n=12) and miR-20b mimics group (n=12). The rats in normal group were fed normally, while those in model group and miR-20b mimics group were used to establish knee osteoarthritis models. After modeling, model group was not given any intervention, but miR-20b mimics group received intra-articular injection of miR-20b mimics once a day for 2 weeks. Basso, Beattie and Bresnahan (BBB) limb motor function scoring was performed at 1, 5, 7 and 14 days after the modeling, and samples were obtained after 2 weeks of intervention. Next, hematoxylin and eosin (H&E) staining was applied to observe tissue morphology, Markin's scoring was utilized to evaluate articular cartilage degeneration, and immunohistochemistry was employed to detect the expressions of BMP2 and Smad1. Thereafter, the expression of miR-20b was detected via qPCR, the content of cartilage oligomeric matrix protein (COMP) and C-telopeptide of type II collagen (CTX-II) was measured via enzyme-linked immunosorbent assay (ELISA), and the expressions of BMP2 and Smad1 proteins were examined via Western blotting (WB). BBB limb motor function scoring showed that compared with that in normal group, the BBB limb motor function score of rats in the other two groups was reduced (P<0.05). In comparison with that in model group, the BBB limb motor function score in miR-20b mimics group was increased from the 7th day after intervention (P<0.05). In addition, H&E staining results manifested that the articular surface in normal group was smooth and flat, with normal morphology, clear structure and no obvious damage. In model group, the articular surface was not smooth and uneven, and more articular cartilage fractures, morphological disorders and structural damages could be observed. Moreover, the articular surface in miR-20b mimics group was slightly damaged and smoother, and its morphology and structure were markedly improved in contrast to that in model group. The Markin's score in normal group was lower than that in model group and miR-20b mimics group (P<0.05), and it was overtly decreased in miR-20b mimics group in comparison with that in model group (P<0.05). Next, immunohistochemistry demonstrated that compared with normal group, the other two groups had lowered positive expressions of BMP2 and Smad1 (P<0.05). In comparison with model group, miR-20b mimics group exhibited notably raised positive expressions of BMP2 and Smad1 (P<0.05). Then it was found from qPCR results that the expression level of miR-20b in the other two groups was overtly reduced compared with that in normal group (P<0.05), and it was prominently elevated in miR-20b mimics group in contrast to that in model group (P<0.05). Besides, ELISA illustrated that the content of COMP and CTX-II in the cartilage tissues in the other two groups was evidently reduced compared with that in normal group (P<0.05), and it was increased prominently in miR-20b mimics group compared with that in model group (P<0.05). Finally, it was revealed by WB examination that the relative expression levels of BMP2 and Smad1 proteins in the other two groups markedly declined in comparison with those in normal group (P<0.05), and they were elevated in contrast to those in model group (P<0.05). MiR-20b can promote cartilage repair and improve articular function in knee osteoarthritis rats by up-regulating the BMP2/Smad1 signaling pathway.

Impact of humid climate on rheumatoid arthritis faecal microbiome and metabolites.

Studies have shown that high humidity is a condition that aggravates the pain of rheumatoid arthritis (RA), but the relevant mechanism is controversial. Currently, there is a lack of experimental animal studies on high humidity as an adverse factor related to the pathogenesis of RA. We used healthy SD rats and collagen-induced arthritis (CIA) rats to investigate the effects of high humidity on arthritis. Integrated metabolomics analyses of faeces and 16S rRNA sequencing of the faecal microbiota were performed to comprehensively assess the diversity of the faecal microbiota and metabolites in healthy and CIA rats. In this study, high humidity aggravated arthritis in CIA rats, which manifested as articular cartilage lesions, increased arthritis scores, and an increase in proinflammatory cytokines. High humidity had a certain effect on the articular cartilage extent, arthritis score and proinflammatory cytokines of healthy rats as well. Furthermore, high humidity caused significant changes in faecal microbes and metabolites in both healthy and CIA rats. 16S rRNA sequencing of faecal samples showed that high humidity increased the amount of inflammation-related bacteria in healthy and CIA rats. Faecal metabolomics results showed that high humidity significantly altered the level of faecal metabolites in healthy rats and CIA rats, and the changes in biological functions were mainly related to the inflammatory response and oxidative stress. Combined analysis showed that there was a strong correlation between the faecal microbiota and faecal metabolites. High humidity is an adverse factor for the onset and development of RA, and its mechanism is related to the inflammatory response and oxidative stress. However, the question of how high humidity impacts RA pathogenesis needs to be further investigated.

Simultaneous determination of 13 paralytic shellfish toxins and tetrodotoxin in marine shellfish by porous graphitic carbon solid-phase extraction and hydrophilic interaction chromatography-tandem mass spectrometry.

The lethal neurotoxins, paralytic shellfish toxins (PSTs), and tetrodotoxin (TTX) have recently been found in marine shellfish from many coastal states. Herein, we applied a sensitive and reliable ultra-performance hydrophilic interaction chromatography (HILIC)-tandem mass spectrometry (MS) method to determine 13 PSTs and TTX in marine shellfish using a porous carbon solid-phase extraction (SPE). This in-house validation study required the development of a novel chromatographic separation using a HILIC-Z column, which was necessary to retain highly polar compounds. Using acetonitrile as the organic phase and ammonium formate-formic acid buffer as the aqueous phase, the quantitative analysis was carried out with an external standard method in the multiple reaction monitoring modes using positive electrospray ionization. To reduce interference, 1% aqueous acetic acid extracts of the shellfish samples were cleaned up by ion-pair SPE using a porous graphitic carbon cartridge. The calibration curves for PSTs and TTX were linear (R2 > 0.995), and the sensitivity was good, with limits of detection (LODs) of 1.7-13.7 µg/kg, and limits of quantitation (LOQs) of 5.2-41.0 µg/kg. The recoveries were 76.5-95.5% with RSDs of 3.1-12.0%. Finally, We applied the method for the determination of PSTs and TTX in three batches of Nassarius showing excellent method accuracy against expected values.

Rapid Measurement of Residual Kanamycin Using Highly Specific Biomimetic Recognition Paper-Based Chip.

The development of highly specific biomimetic recognition material is a challenge for rapid detection of harmful residues in foodstuff. In this study, a paper-based boronate affinity metal-organic framework/molecularly imprinted polymer microfluidic chip (FZS-BA@MIP) was constructed based on the in situ construction strategy, which was also designed as a highly specific biomimetic recognition module. Here, the homogeneous zeolitic imidazole framework-8 (ZIF-8) membrane served as a great scaffold and enrichment layer. Besides, the recognition layer of MIP was prepared based on a highly oriented boronate affinity surface imprinting strategy. With the aid of the liquid flow channel, the highly specific enrichment and visual detection for antibiotic residues like kanamycin in actual products were achieved on the paper chip module of an integrated lateral flow platform. The whole analysis process could be accomplished within 30 min. In brief, this study offered a new integrated biomimetic recognition platform for visually detecting harmful veterinary residues containing cis-diols, which demonstrated promising commercial value in point-of-care testing of foodborne hazardous compounds.

[Rapid screening and confirmation of 86 illegally added chemicals in fishery drugs by ultra performance liquid chromatography-quadrupole-time-of-flight mass spectrometry].

With the rapid expansion of fisheries, one of the most significant limitations to the sustainable development of fisheries in China is the quality and safety of fishery products owing to the abuse of fishery drugs and the use of illegal and/or restricted chemicals in fishery drugs. A range of chemicals that are potential hazards to fishery drugs were selected for screening in this study. A comprehensive analytical method was developed, based on ultra performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS), for the rapid screening of 86 types of illegally added chemicals in fishery drugs. The fishery drug samples were extracted with 80% (v/v) acetonitrile aqueous solution and diluted to reduce matrix effects. The 86 target compounds were separated on an ACQUITY PREMIER HSS T3 column (100 mm×2.1 mm, 1.8 µm), with methanol and 0.1% formic acid as mobile phases, via gradient elution. The extract was directly analyzed by UPLC-Q-TOF-MS using electrospray ionization in the positive mode. The external standard method was used for quantification. In this study, the extraction reagent and purification procedure were selected to develop a simple and effective pre-treatment protocol. The effects of the chromatographic column, mobile phase, and fragmentation voltage on the separation and sensitivity of the 86 substances were evaluated to determine the optimum instrument conditions. An accurate mass database and fragment ion library were created for the rapid qualitative and quantitative analysis of the 86 illegally added chemicals in fishery drugs. The retention time, isotopic abundance and spacing, and precise mass of the principal diagnostic ion for each analyte were used for identification. The information on the fragment ions obtained from the target MS/MS profiles was compared with that from a database to ensure the accuracy of the qualitative results. The chromatographic peak area of each target analyte was used for quantification. The analytical detection was based on the retention time deviation of ±0.35 min, accurate mass deviation of ±10×10-6, and major adduct forms, including [M+H]+, [M+Na]+, and [M+NH4]+. To evaluate the matrix effects of the 86 target chemicals at varied dilution ratios, two types of antibiotics and four types of Chinese herbal medicines were selected as typical samples. Considering the instrument tolerance as well as sensitivity and accuracy of the procedure, the recommended dilution ratios for antibiotics and Chinese herbal medicines were 50 times and 10 times, respectively. Two different types of calibration curves were prepared; one was the solvent calibration curve for antibiotics and the other was the matrix calibration curve for Chinese herbal medicines. For a given concentration, the calibration curves of the 86 target chemicals were linear with correlation coefficients of at least 0.99. The recoveries ranged from 76.8% to 112.1% with relative standard deviations (RSDs) (n=3) of less than 11.7%. The limit of quantification (LOQ) ranges of the compounds in Chinese herbal medicines and antibiotics were 1-15 mg/kg and 5-75 mg/kg, respectively. To evaluate the screening detection limits (SDLs) of each compound, a mixed standard solution was added to a fishery drug sample at varied concentrations. The SDL ranges of the compounds in Chinese herbal medicines and antibiotics were 1-15 and 5-50 mg/kg, respectively. This approach resulted in SDLs that satisfy the actual screening requirements. Because of its rapid nature, simplicity, accuracy, and sensitivity, the method may be used in the high-throughput screening and identification of illegally added chemicals in many types of fishery drugs. This method was applied to a monitoring project for the quality and safety of fishery inputs in Zhejiang Province. Sixty fishery drug samples were evaluated, among which eight Chinese herbal medicine samples were found to contain unspecified ingredients and one antibiotic sample was found to be free of any active substances. Thus, an effective technical method to monitor the quality and safety of fishery drugs was developed.

iTRAQ-based quantitative proteomics analysis of the hepatoprotective effect of melatonin on ANIT-induced cholestasis in rats.

The therapeutic effects of melatonin on cholestatic liver injury have received widespread attention recently. The aim of the present study was to investigate the mechanisms of the anti-cholestatic effects of melatonin against α-naphthyl isothiocyanate (ANIT)-induced liver injury in rats and to screen for potential biomarkers of cholestasis through isobaric tags for relative and absolute quantitation (iTRAQ) proteomics. Rats orally received melatonin (100 mg/kg body weight) or an equivalent volume of 0.25% carboxymethyl cellulose sodium salt 12 h after intraperitoneal injection of ANIT (75 mg/kg) and were subsequently sacrificed at 36 h after injection. Liver biochemical indices were determined and liver tissue samples were stained using hematoxylin-eosin staining, followed by iTRAQ quantitative proteomics to identify potential underlying therapeutic mechanisms and biomarkers. The results suggested that the expression levels of alanine transaminase, aspartate aminotransferase, total bilirubin and direct bilirubin were reduced in the rats treated with melatonin. Histopathological observation indicated that melatonin was effective in the treatment of ANIT-induced cholestasis. iTRAQ proteomics results suggested that melatonin-mediated reduction in ANIT-induced cholestasis may be associated with enhanced antioxidant function and relieving abnormal fatty acid metabolism. According to pathway enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes, the major metabolic pathways for the metabolism of melatonin are fatty acid degradation, the peroxisome proliferator-activated receptor signaling pathway, fatty acid metabolism, chemical carcinogenesis, carbon metabolism, pyruvate metabolism, fatty acid biosynthesis and retinol metabolism, as well as drug metabolism via cytochrome P450. Malate dehydrogenase 1 and glutathione S-transferase Yb-3 may serve as potential targets in the treatment of ANIT-induced cholestasis with melatonin.

Synthesis of dummy-template molecularly imprinted polymer adsorbents for solid phase extraction of aminoglycosides antibiotics from environmental water samples.

A novel dummy molecularly imprinted polymers (DMIPs) for aminoglycoside antibiotics (AAs) was prepared for the first time by precipitation polymerization using raffinose as template molecule, methacrylic acid as functional monomer and trimethylolpropane triacrylate as cross-linker. The obtained DMIPs were characterized in detail, and their adsorbing and recognition performance were evaluated. The results showed that the DMIPs exhibited specific recognition towards six AAs with large adsorption capacity. The dummy molecularly imprinted solid phase extraction (DMISPE) conditions including elution/washing solutions and sample loading volumes were optimized. Under optimum conditions, a convenient and efficient method for the determination of AAs in environmental water samples based on DMISPE coupling with hydrophilic interaction-high performance liquid chromatography-tandem mass spectrometry was established. The developed method showed good linearity with correlation coefficients higher than 0.9921 for all the analytes and good recoveries (70.8-108.3%) with relative standard deviations from 2.6 to 11.4% spiked at three different concentration levels in water samples. The limit of detection (S/N = 3) ranged from 0.006 to 0.6 ng/mL. The results demonstrated good potential of DMIPs for sample pretreatment of trace AAs in environmental water samples.

Melatonin ameliorates ANIT­induced cholestasis by activating Nrf2 through a PI3K/Akt­dependent pathway in rats.

Cholestasis is a devastating liver condition which is increasing in prevalence worldwide; however, its underlying pathogenic mechanisms remain to be fully elucidated. It was hypothesised that melatonin may alleviate the hepatic injury associated with cholestasis due to its established antioxidant effects. Therefore, the effect and potential anticholestatic properties of melatonin were investigated in rats with α­naphthylisothiocyanate (ANIT)­induced liver injury, a common animal model that mimics the cholestasis­associated liver injury in humans. The rats received intraperitoneal injection of ANIT with or without subsequent treatment with melatonin, and were sacrificed 24 h later. The serum biochemistry parameters of the liver were measured using conventional laboratory assays, and the liver tissue was subjected to conventional histological examination, reverse transcription­quantitative polymerase chain reaction analysis and western blotting. The levels of alanine transaminase, aspartate transaminase, total bilirubin, direct bilirubin, total bile acids, alkaline phosphatase, γ­glutamyl transferase and glutathione were restored in rats treated with melatonin. Histological examination provided further evidence supporting the protective effect of melatonin against ANIT­induced cholestasis. In addition, the mRNA and protein expression levels of glutamate cysteine ligase, phosphorylated Akt and nuclear factor­erythroid 2­related factor­2 were restored in rats treated with melatonin. These findings indicate that melatonin is a natural agent that appears to be promising for the treatment of cholestasis, and that the anticholestatic effects of melatonin involve the alleviation of oxidative stress.

Identification of potential biomarkers in cholestasis and the therapeutic effect of melatonin by metabolomics, multivariate data and pathway analyses.

The present study investigated the anti­cholestatic effect of melatonin (MT) against α­naphthyl isothiocyanate (ANIT)­induced liver injury in rats and screened for potential biomarkers of cholestasis. Rats were administered ANIT by intraperitoneal injection and then sacrificed 36 h later. Serum biochemical parameters were measured and liver tissue samples were subjected to histological analysis. Active components in the serum were identified by gas chromatography­mass spectrometry, while biomarkers and biochemical pathways were identified by multivariate data analysis. The results revealed that the serum levels of alanine aminotransferase, aspartate aminotransferase, total bilirubin, direct bilirubin, γ­glutamyl transpeptidase, and alkaline phosphatase were reduced in rats with ANIT­induced cholestasis that were treated with MT. The histological observations indicated that MT had a protective effect against ANIT­induced hepatic tissue damage. Metabolomics analysis revealed that this effect was likely to be associated with the regulation of compounds related to MT synthesis and catabolism, and amino acid metabolism, including 5­aminopentanoate, 5­methoxytryptamine, L­tryptophan, threonine, glutathione, L­methionine, and indolelactate. In addition, principal component analysis demonstrated that the levels of these metabolites differed significantly between the MT and control groups, providing further evidence that they may be responsible for the effects induced by MT. These results provide an insight into the mechanisms underlying cholestasis development and highlight potential biomarkers for disease diagnosis.

[Rapid and simultaneous determination of seven microcystins in fish meat by liquid chromatography-tandem mass spectrometry coupled with pass-through solid phase extraction].

An analytical method was developed for the simultaneous and rapid determination of seven microcystins in fish meat by liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with pass-through solid phase extraction (SPE). The samples were extracted with methanol-water (90:10, v/v) after heat treatment by water bath at 80℃, and then cleaned up with an Oasis PRiME HLB pass-through SPE column. The samples were analyzed directly on a Waters XSelect HSS T3 column using 0.1% (v/v) aqueous formic acid and acidified acetonitrile (0.1% formic acid, v/v) as mobile phases. Qualitative and quantitative analysis of the analytes was carried out under the multiple reaction monitoring mode with positive electrospray ionization. The matrix matching external standard method was used for quantitation analysis. To solve the problem of parent ion selection of the microcystins, the ionization characteristics of microcystins were evaluated under different mobile phase conditions. Finally, the results showed that the acid could promote the intensity of the doubly charged ions significantly. The calibration curves were linear well in the corresponding concentration ranges, with correlation coefficient ≥ 0.99. The limits of quantification ranged from 0.30 to 2.0 µ g/kg. The average spiked recoveries for the seven microcystins were between 70.6% and 96.1% with the relative standard deviations of 3.4%-9.6%. The proposed method is sensitive, accurate, and efficient. It is applicable for the determination of microcystins in fish meat.