Integrated analysis of microRNAs, circular RNAs, long non-coding RNAs, and mRNAs revealed competing endogenous RNA networks involved in brown adipose tissue whitening in rabbits.

BACKGROUND: The brown adipose tissue (BAT) is a target for treating obesity. BAT losses thermogenic capacity and gains a "white adipose tissue-like" phenotype ("BAT whitening") under thermoneutral environments, which is a potential factor causing a low curative effect in BAT-related obesity treatments. Circular RNAs (circRNAs) and long non-coding RNAs (lncRNAs) can act as competing endogenous RNAs (ceRNA) to mRNAs and function in various processes by sponging shared microRNAs (miRNAs). However, the roles of circRNA- and lncRNA-related ceRNA networks in regulating BAT whitening remain litter known. RESULTS: In this study, BATs were collected from rabbits at day0 (D0), D15, D85, and 2 years (Y2). MiRNA-seq was performed to investigate miRNA changes during BAT whitening. Then, a combined analysis of circRNA-seq and whole-transcriptome sequencing was used for circRNA assembly and quantification during BAT whitening. Our data showed that 1187 miRNAs and 6204 circRNAs were expressed in the samples, and many of which were identified as significantly changed during BAT whitening. Target prediction showed that D0-selective miRNAs were significantly enriched in the Ras, MAPK, and PI3K-Akt signaling pathways, and Y2-selective miRNAs were predicted to be involved in cell proliferation. The cyclization of several circRNAs could form novel response elements of key thermogenesis miRNAs at the back-splicing junction (BSJ) sites, and in combination with a dual-luciferase reporter assay confirmed the binding between the BSJ site of novel_circ_0013792 and ocu-miR-378-5p. CircRNAs and lncRNAs have high cooperativity in sponging miRNAs during BAT whitening. Both circRNA-miRNA-mRNA and lncRNA-miRNA-mRNA triple networks were significantly involved in immune response-associated biological processes. The D15-selective circRNA might promote BAT whitening by increasing the expression of IDH2. The Y2-selective circRNA-related ceRNA network and lncRNA-related ceRNA network might regulate the formation of the WAT-like phenotype of BAT via MAPK and Ras signaling pathways, respectively. CONCLUSIONS: Our work systematically revealed ceRNA networks during BAT whitening in rabbits and might provide new insight into BAT-based obesity treatments.

Hydrogen generation from Al-NiCl2/NaBH4 mixture affected by lanthanum metal.

The effect of La on Al/NaBH(4) hydrolysis was elaborated in the present paper. Hydrogen generation amount increases but hydrogen generation rate decreases with La content increasing. There is an optimized composition that Al-15 wt% La-5 wt% NiCl(2)/NaBH(4) mixture (Al-15 wt% La-5 wt% NiCl(2)/NaBH(4) weight ratio, 1 : 3) has 126 mL g(-1 )min(-1) maximum hydrogen generation rate and 1764 mL g(-1) hydrogen generation amount within 60 min. The efficiency is 88%. Combined with NiCl(2), La has great effect on NaBH(4) hydrolysis but has little effect on Al hydrolysis. Increasing La content is helpful to decrease the particle size of Al-La-NiCl(2) in the milling process, which induces that the hydrolysis byproduct Ni(2)B is highly distributed into Al(OH)(3) and the catalytic reactivity of Ni(2)B/Al(OH)(3) is increased therefore. But hydrolysis byproduct La(OH)(3) deposits on Al surface and leads to some side effect. The Al-La-NiCl(2)/NaBH(4) mixture has good stability in low temperature and its hydrolytic performance can be improved with increasing global temperature. Therefore, the mixture has good safety and can be applied as on board hydrogen generation material.

Indispensable but insufficient role of renal D-amino acid oxidase in chiral inversion of NG-nitro-D-arginine.

Unidirectionally chiral inversion of N(G)-nitro-D-arginine (D-NNA) to its L-enantiomer (L-NNA) occurred in rats, and it was blocked markedly (ca. 80%) by renal vascular ligation, and entirely (100%) by the D-amino acid oxidase (DAO) inhibitor sodium benzoate, suggesting that renal DAO is essential for the inversion. However, the doses of sodium benzoate administrated were extremely high (e.g., 400 mg/kg) due to its low potency. It is thus possible that sodium benzoate-mediated blockade of D-NNA inversion might be due to its nonspecific (or non-DAO-related) effects. In addition, after D-NNA was incubated with the pure enzyme of DAO in vitro without tissue homogenates, L-NNA was not produced, even though D-NNA was disposed. We propose that this occurred because D-NNA was first converted to its corresponding alpha-keto acid by DAO and then to L-NNA by transaminase(s); however, there was no direct evidence for this process. The goal of this study is to further elucidate the process of D-NNA chiral inversion both in vivo and in in vitro tissue homogenates by comparing mutant ddY/DAO(-/-) mice that lack DAO activity entirely compared to normal ddY/DAO(+/+) mice and Swiss mice. Furthermore, the ability to produce L-NNA from D-NNA-corresponding alpha-keto acids (N(G)-nitroguanidino-2-oxopentanoic acid) produced by porcine kidney-derived DAO (pkDAO) was also studied in the DAO inhibitor-pretreated rats. We found that D-NNA chiral inversion occurred in Swiss mice and ddY/DAO(+/+) mice both in vivo and in in vitro kidney homogenates, but not in ddY/DAO(-/-) mice, correlated to their DAO activities. The alpha-keto acid (N(G)-nitro-guanidino-2-oxopentanoic acid) from D-NNA was able to produce L-NNA, and subsequent vasoconstriction and pressor responses. These results indicate that the role of renal DAO is indispensible but insufficient for chiral inversion of D-NNA and other neutral and polar D-amino acids, and unidentified aminotransferase(s) are involved in a subsequent mechanism for the process of chiral inversion.

[Characteristics of Particulate Matter Emissions from the Coking Process].

To investigate the particulate matter emission characteristics of various emitting sources of the coking process of iron and steel plants, an automatic dust (smoke) tester and an eight-staged Anderson sampler were employed to conduct onsite sampling of particulate matter emissions from the coking process, including coal loading and coke pushing, coke dry quenching exhaust and coke screening and transferring in a steel plant, based on the measurement of particulate matter in the exhaust of fixed sources and sampling of gaseous pollutants. The morphology, particle size distribution, and chemical composition of the particulate matter from different sources were investigated. The results show that the single particles can be divided into five categories:iron-rich, silicon-rich, calcium-rich, carbon, and smoke polymer. They mainly appear in four forms:polygon block, irregular lamellae, lumps, and floc. The particle size of the coal loading and coke pushing unit mainly is 3.3-4.7 µm, while it is 3.3-4.7 µm and 5.8-9.0 µm for the dry quenching exhaust and 4.7-5.8 µm for the coke screening and transferring unit. The main chemical components of particulate matter in the coking process are C, SiO2, Al2O3, S, CaO, and TFe, with contents of 76.30%-81.30%, 5.36%-5.91%, 3.96%-4.26%, 1.15%-1.34%, 0.52%-1.59%, and 0.81%-1.34%, respectively.