These findings disclose a novel regulatory pathway that is composed of HRCR, miR-223, and ARC. Modulation of their levels provides an attractive therapeutic target for the treatment of cardiac hypertrophy and heart failure.

A comprehensive investigation was carried out to determine the changes that occurred in water-stressed cucumber (Cucumis sativus L.) in response to melatonin treatment. We examined the potential roles of melatonin during seed germination and root generation and measured its effect on reactive oxygen species (ROS) levels, antioxidant enzyme activities, and photosynthesis. Melatonin alleviated polyethylene glycol induced inhibition of seed germination, with 100 μm melatonin-treated seeds showing the greatest germination rate. Melatonin stimulated root generation and vitality and increased the root:shoot ratio; therefore, melatonin may have an effect on strengthening cucumber roots. Melatonin treatment significantly reduced chlorophyll degradation. Seedlings treated with 100 μm melatonin clearly showed a higher photosynthetic rate, thus reversing the effect of water stress. Furthermore, the ultrastructure of chloroplasts in water-stressed cucumber leaves was maintained after melatonin treatment. The antioxidant levels and activities of the ROS scavenging enzymes, i.e., superoxide dismutase, peroxidase, and catalase, were also increased by melatonin. These results suggest that the adverse effects of water stress can be minimized by the application of melatonin.

Although previous studies have found that melatonin can promote seed germination, the mechanisms involved in perceiving and signaling melatonin remain poorly understood. In this study, it was found that melatonin was synthesized during cucumber seed germination with a peak in melatonin levels occurring 14 hr into germination. This is indicative of a correlation between melatonin synthesis and seed germination. Meanwhile, seeds pretreated with exogenous melatonin (1 μM) showed enhanced germination rates under 150 mM NaCl stress compared to water-pretreated seeds under salinity stress. There are two apparent mechanisms by which melatonin alleviated salinity-induced inhibition of seed germination. Exogenous melatonin decreased oxidative damage induced by NaCl stress by enhancing gene expression of antioxidants. Under NaCl stress, compared to untreated control, the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were significantly increased by approximately 1.3-5.0-fold, with a concomitant 1.4-2.0-fold increase of CsCu-ZnSOD, CsFe-ZnSOD, CsCAT, and CsPOD in melatonin-pretreated seeds. Melatonin also alleviated salinity stress by affecting abscisic acid (ABA) and gibberellin acid (GA) biosynthesis and catabolism during seed germination. Compared to NaCl treatment, melatonin significantly up-regulated ABA catabolism genes (e.g., CsCYP707A1 and CsCYP707A2, 3.5 and 105-fold higher than NaCl treatment at 16 hr, respectively) and down-regulated ABA biosynthesis genes (e.g., CsNECD2, 0.29-fold of CK2 at 16 hr), resulting in a rapid decrease of ABA content during the early stage of germination. At the same time, melatonin positively up-regulated GA biosynthesis genes (e.g., GA20ox and GA3ox, 2.3 and 3.9-fold higher than NaCl treatment at 0 and 12 hr, respectively), contributing to a significant increase of GA (especially GA4) content. In this study, we provide new evidence suggesting that melatonin alleviates the inhibitory effects of NaCl stress on germination mainly by regulating the biosynthesis and catabolism of ABA and GA4.

The abnormal autophagy is associated with a variety of cardiovascular diseases. Long noncoding RNAs (lncRNAs) are emerging as new factors in gene regulation, but how lncRNAs operate in the regulation of autophagy in the heart is unclear. Here we report that a long noncoding RNA, named autophagy promoting factor (APF), can regulate autophagic cell death by targeting miR-188-3p and ATG7. The results show that miR-188-3p suppresses autophagy and myocardial infarction by targeting ATG7. Further, we find that APF lncRNA regulates miR-188-3p, and thus affects ATG7 expression, autophagic cell death and myocardial infarction. Our present study reveals a novel regulating model of autophagic programme, which comprises APF, miR-188-3p and ATG7 in the heart. Modulation of their levels may serve as potential targets and diagnostic tools for novel therapeutic strategies of myocardial infarction and heart failure.

Cucumber is a model cucurbitaceous plant with a known genome sequence which is important for studying molecular mechanisms of root development. In this study, RNA sequencing was employed to explore the mechanism of melatonin-induced lateral root formation in cucumber under salt stress. Three groups of seeds were examined, that is, seeds primed without melatonin (CK), seeds primed in a solution containing 10 or 500 μmol/L melatonin (M10 and M500, respectively). These seeds were then germinated in NaCl solution. The RNA-seq analysis generated 16,866,670 sequence reads aligned with 17,920 genes, which provided abundant data for the analysis of lateral root formation. A total of 17,552, 17,450, and 17,393 genes were identified from roots of the three treatments (CK, M10 and M500, respectively). The expression of 121 genes was significantly up-regulated, and 196 genes were significantly down-regulated in M500 which showed an obvious increase on the number of lateral roots. These genes were significantly enriched in 57 KEGG pathways and 16 GO terms (M500 versus CK). Based on their expression pattern, peroxidase-related genes were selected as the candidates to be involved in the melatonin response. Several transcription factor families might play important roles in lateral root formation processes. A number of genes related to cell wall formation, carbohydrate metabolic processes, oxidation/reduction processes, and catalytic activity also showed different expression patterns as a result of melatonin treatments. This RNA-sequencing study will enable the scientific community to better define the molecular processes that affect lateral root formation in response to melatonin treatment.

SummaryTomato fruits were treated by exogenous melatonin. The effect of melatonin on ethylene biosynthesis, ethylene perception, and ethylene signalling may contribute to fruit ripening and quality improvement in tomato.

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BackgroundGlioma is one of the most common and aggressive primary malignant tumor in the brain. Accumulating evidences indicated that aberrantly expressed non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), contribute to tumorigenesis. However, potential mechanisms between lncRNAs and miRNAs in glioma remain largely unknown.MethodsLong non-coding RNA activated by TGF-β (LncRNA-ATB) expression in glioma tissues and cells was quantified by quantitative reverse transcription–PCR. Glioma cell lines U251 and A172 were transfected with sh-ATB, miR-200a mimics, miR-200a inhibitors, after we assayed the cell phenotype and expression of the relevant molecules. Dual-luciferase reporter assay, RIP and a xenograft mouse model were used to examine the expression of sh-ATB and its target gene miR-200a.ResultsATB is abnormally up-regulated both in glioma tissues and cell lines compared with normal brain tissues, and glioma patients with high ATB expression had shorter overall survival time. Knockdown of ATB significantly inhibits glioma malignancy, including cell proliferation, colony formation, migration, invasion in vitro, and the xenograft tumor formation in vivo. In addition, ATB was confirmed to target miR-200a, and miR-200a inhibition reversed the malignant characteristics of ATB knockdown on glioma cells. In particular, ATB may act as a ceRNA, effectively becoming a sink for miR-200a, thereby modulating the derepression of TGF-β2.ConclusionsOur findings suggest that ATB plays an oncogenic role of glioma cells by inhibiting miR-200a and facilitating TGF-β2 in glioma, thereby may represent a potential therapeutic target for the treatment of human glioma.