Long Non-Coding RNA (lncRNA) Small Nucleolar RNA Host Gene 15 (SNHG15) Alleviates Osteoarthritis Progression by Regulation of Extracellular Matrix Homeostasis.

BACKGROUND Growing evidence suggests that long non-coding RNAs (lncRNAs), as decoys of microRNAs (miRNAs), are involved in osteoarthritis (OA) progression, but the potential mechanism of lncRNA SNHG15 in OA remains unknown. Thus, the present study explored the molecular mechanism of SNHG15 in OA progression. MATERIAL AND METHODS OA chondrocytes were created by 20 ng/ml IL-1ß stimulation, and the experimental OA model was created by destabilization of the medial meniscus (DMM) surgery. Cartilage histomorphology was observed by safranin and fast green double dyeing. The relationships between SNHG15 and miR-7, KLF4, and miR-7 were determined by dual-luciferase assay or RNA immunoprecipitation (RIP). Immunofluorescence was used to detect the expressions of Ki67, collagen II, and Aggrecan. Moreover, SNHG15, miR-7, KLF4, MMP3, ADAMTS5, COL2A1, Aggrecan, and ß-catenin expressions were assessed by qRT-PCR or Western blot. The methylation status of SNHG15 promoter was evaluated by MS-PCR. RESULTS Underexpression of KLF4 and SHNG15 and overexpression of miR-7 were found in human OA knee cartilage tissues and IL-1ß-stimulated OA chondrocytes. SHNG15 overexpression significantly inhibited ECM degradation and promoted chondrocyte formation of OA chondrocytes. Furthermore, SNHG15 regulated KLF4 expression by sponging miR-7. Further analysis found that SNHG15 significantly inhibited b-catenin in OA chondrocytes. SNHG15 had a higher level of methylation in human OA tissues than in normal cartilage tissues. CONCLUSIONS Our results revealed that SNHG15 alleviated OA progression by regulating ECM homeostasis, which provides a promising target for OA therapy.

Volatile organic compounds of Hanseniaspora uvarum increase strawberry fruit flavor and defense during cold storage.

Volatile organic compounds (VOCs) of antagonistic yeasts are considered as environmental safe fumigants to promote the resistance and quality of strawberry (Fragaria ananassa). By GC-MS assays, VOCs of Hanseniaspora uvarum (H. uvarum) fumigated strawberry fruit showed increased contents of methyl caproate (5.8%), methyl octanoate (5.1%), and methyl caprylate (10.9%) in postharvest cold storage. Possible mechanisms of H. uvarum VOCs involved in regulations of the defense-related enzymes and substances in strawberry were investigated during postharvest storage in low temperature and high humidity (2 ± 1°C, RH 90%-95%). Defense-related enzymes assays indicated H. uvarum VOCs stimulated the accumulation of CAT, SOD, POD, APX, PPO, and PAL and inhibited biosynthesis of MDA in strawberry fruit under storage condition. Moreover, the expression levels of related key enzyme genes, such as CAT, SOD, APX42, PPO, and PAL6, were consistently increased in strawberry fruit after H. uvarum VOCs fumigation.

Multifunctional N,S co-doped carbon dots for sensitive probing of temperature, ferric ion, and methotrexate.

In this paper, we have presented a facile method to fabricate nitrogen and sulfur co-doped carbon dots (N,S-CDs) for blood methotrexate (MTX) sensing applications. The N,S-CDs with quantum yield up to 75% were obtained by one-step hydrothermal carbonization, using reduced glutathione and citric acid as the precursors. With this approach, the formation and the surface passivation of N,S-CDs were carried out simultaneously, resulting in intrinsic fluorescence emission. Owing to their pronounced temperature dependence of the fluorescence emission spectra, resultant N,S-CDs can work as versatile nanothermometry devices by taking advantage of the temperature sensitivity of their emission intensity. In addition, the obtained N,S-CDs facilitated high selectivity detection of Fe3+ ions with a detection limit as low as 0.31 µM and a wide linear range from 3.33 to 99.90 µM. More importantly, the added MTX selectively led to the fluorescence quenching of the N,S-CDs. Such fluorescence responses were used for well quantifying MTX in the range of 2.93 to 117.40 µM, and the detection limit was down to 0.95 µM. Due to "inert" surface, the N,S-CDs well resisted the interferences from various biomolecules and exhibited excellent selectivity. The proposed sensing system was successfully used for the assay of MTX in human plasma. Due to simplicity, sensitivity, selectivity, and low cost, it exhibits great promise as a practical platform for MTX sensing in biological samples. Graphical Abstract.

[Changes of granulocyte distribution induced by thyroxin and epinephrine: experiment with rabbits].

OBJECTIVE: To investigate the distribution of granulocyte during thyrotoxicosis and the relation of granulopenia and the gathering of circulating granulocytes into the marginal pool. METHODS: Forty-five rabbits were randomly divided into 3 equal groups: epinephrine group fed with levo-thyroxin (LT4) for 14 days, injected subcutaneously with epinephrine 0.07 mg/kg, and undergoing collection of peripheral blood samples for white blood cell and granulocyte counts, free blood triiodothyroxine (FT3) and free blood thyroxine (FT4), electrocardiography, and body weight measurement; labeled group fed with LT4 for 14 days, injected subcutaneously with 131I-labeled anti-human granulocyte monoclonal antibody, and killed 6 hours later to calculate the ratio of radioactivity of heart, liver, spleen, and muscle tissues to blood (CPM/g), and control group, not fed with L-T4 but injected with 131I-labeled anti-human granulocyte monoclonal antibody on the day 14, and killed 6 hours later to calculate the ratio of radioactivity of tissues to blood. RESULTS: After 14-day feeding of L-T4, the heart rates of the epinephrine and labeled groups were significantly higher than those before injection, and the FT3 and FT4 levels were significantly increased;the venous WBC and granulocyte counts were significantly reduced. But the granulocyte count of 13 of the 15 rabbits in the epinephrine group increased 20 minutes after the injection of epinephrine, even becoming 2-4.8 times as high as those before the injection in 7 rabbits. The heart, liver, spleen, and muscle tissues to blood CPM/g ratios of the labeled group were all significantly higher than those of the control group (all P<0.01). CONCLUSION: During thyrotoxicosis the circulating granulocytes are reduced and the distribution of circulating granulocytes is abnormal with a gathering phenomenon of the granulocytes into the marginal pool.