Identification and characterization of circRNAs in maize seedlings under deficient nitrogen.

Here, deep sequencing results of the maize transcriptome in leaves and roots were compared under high-nitrogen (HN) and low-nitrogen (LN) conditions to identify differentially expressed circRNAs (DECs). Circular RNAs (circRNAs) are covalently closed non-coding RNA with widely regulatory potency that has been identified in animals and plants. However, the understanding of circRNAs involved in responsive nitrogen deficiency remains to be elucidated. A total of 24 and 22 DECs were obtained from the leaves and roots, respectively. Ten circRNAs were validated by divergent and convergent primers, and 6 DECs showed the same expression tendency validated by reverse transcriptase-quantitative PCR. Integrating the identified differentially expressed miRNAs, 34 circRNAs could act as miRNA decoys, which might play important roles in multiple biological processes, including organonitrogen compound biosynthesis and regulation of the metabolic process. A total of 51 circRNA-parent genes located in the genome-wide association study identified loci were assessed between HN and LN conditions and were associated with root growth and development. In summary, our results provide valuable information regarding further study of maize circRNAs under nitrogen deficiency and provide new insights into screening of candidate genes as well as the improvement of maize regarding nitrogen deficiency resistance. CircRNA-miRNA-mRNA co-expression networks were constructed to explore the circRNAs that participated in biological development and nitrogen metabolism.

LncRNA DANCR regulates osteosarcoma migration and invasion by targeting miR-149/MSI2 axis.

OBJECTIVE: As a new LncRNA, anti-differentiated non-coding RNA (DANCR) plays an important role in tumorigenesis and development, and its molecular mechanism in osteosarcoma is unclear. In this study, by investigating osteosarcoma tissue and cells, we explored the molecular mechanism by which lncRNA DANCR regulates the occurrence and development of osteosarcoma by targeting the miR-149 / MSI2 axis. PATIENTS AND METHODS: In this study, osteosarcoma tissues and adjacent tissues in 109 patients were collected, and the relative expression of DANCR was detected by qPCR. The correlation between DANCR expression and clinical classification was statistically analyzed. In order to explore the potential molecular mechanism of DANCR related to tumor migration and invasion, an overexpression and silencing test was performed on the osteosarcoma cell line Saos-2, and then qPCR method was used to test the expression of miR149, and cell scratch test was used to detect invasion after DANCR silencing and miR149 overexpression. Transwell assay was used to detect the invasion after DANCR silencing and miR149 overexpression. Finally, Western blot was used to verify the expression of MSI2 protein after overexpression and silencing of miR-149. RESULTS: DANCR was significantly up-regulated in both osteosarcoma tissue and cells. The high expression of DANCR was significantly positively correlated with tissue typing and advanced TNM stage. DANCR can significantly reduce the migration and invasion of osteosarcoma cells. miRNA overexpression significantly reduced osteosarcoma cell migration and invasion. When miR-149 was overexpressed, MSI2 protein expression was significantly down-regulated. When miR-149 was silenced, MSI2 protein was significantly up-regulated. CONCLUSIONS: LncRNA DANCR plays an important regulatory role in the occurrence and development of osteosarcoma. It may be used as a potential target in the treatment of osteosarcoma in the future, by targeting the miR-149/MSI2 axis to regulate the occurrence and development of osteosarcoma.

Sapphire-based graphene saturable absorber for long-time working femtosecond lasers.

We report a long-time working femtosecond laser using metal-free sapphire-based graphene as a saturable absorber (SA). The sapphire-based graphene yielded excellent nonlinear saturable absorption properties and was demonstrated to be suitable as an SA for an ultrafast solid-state laser. Stable mode-locked pulses of 325 fs were obtained at a central wavelength of 1032 nm with a repetition rate of 66.3 MHz. At pump power of 8.23 W the average output power was 1.78 W and the highest pulse energy reached 26.8 nJ with a peak power of 72.6 kW. Our work opens up a facile route for making reliable graphene SA in the mode-locking technique and also displays an exciting prospect in making low-cost and ultrafast lasers.

Lung cancer cell migration is regulated via repressing growth factor PTN/RPTP ß/ζ signaling by menin.

Menin encoded by the multiple endocrine neoplasia type 1 (MEN1) gene is associated with chromatin and the nuclear matrix and exerts multiple biological functions including regulation of cell proliferation and adhesion. Men1 mutations increase the likelihood of lung cancer development in mice. Menin expression is reduced in certain human non-small cell lung cancer cells, and reduction of menin is closely correlated with increased lung cancer metastasis to lymph nodes. However, it is poorly understood whether menin affects migration of lung cancer cells. In this study, we show that menin-regulated A549 lung cancer cell migration, which was mediated by growth factor pleiotrophin (PTN) and its cell surface receptor, protein tyrosine phosphatase beta/zeta (RPTP ß/ζ). Ectopic menin expression significantly repressed PTN transcription, but indirectly inhibited RPTP ß/ζ expression through repressing PTN expression. Further studies revealed that menin-regulated cell migration through PTN/RPTP ß/ζ, in conjunction with integrin α(v)ß(3), focal adhesion kinase, phosphatidylinositol 3-kinase and phosphorylated extracellular signal regulated kinase 1/2. These findings provide mechanistic insights into the molecular basis for menin/PTN-mediated regulation of A549 lung cancer cell migration.

[Construction of root library by SSH and preliminary analysis of genes responsible for phosphorus deficiency in maize].

An elite maize inbred line with high tolerance to low phosphorus, 178, was studied for constructing root library and analyzing some genes closely related to phosphorus (P) deficiency using SSH and Semi-quantitative RT-PCR. As a result, 3648 preliminary clones were obtained for root library under stress of P deficiency. By DNA sequencing of 34 random clones, we obtained 23 unique EST sequences which are involved in functions of root cell structure, tolerance and defense, protein modification and composition, transcription regulation, metabolism, and other unknown aspects. Five representative genes were further analyzed for their expression models. The results suggested that the molecular mechanism to adapt P deficiency in maize, performed by multi-genes with different contributions, is similar to rice, Arabidopsis and soybean. The expression order of 5 low P tolerant genes in maize root was PAP, GCS, TOM, PDI and AIP. And it was considered preliminarily that physiological and biochemical changes were prior to morphologic changes in maize root and the essential tolerance to low P may be determined by extending absorption of P to wide soil range through adaption of root architecture and root secretions, which is the greatest difference between tolerant and sensitive maize varieties under low P stress.

Suppression of lung adenocarcinoma through menin and polycomb gene-mediated repression of growth factor pleiotrophin.

Menin upregulates transcription of cell-cycle inhibitors to suppress endocrine tumors, but it is poorly understood how menin suppresses non-endocrine tumors such as lung cancer. Here, we show that menin inhibits proliferation of human lung cancer cells and growth of lung cancer in mice. The menin-mediated tumor suppression requires repression of growth factor pleiotrophin (PTN), which binds to its cell surface receptor, anaplastic lymphoma kinase (ALK) that is activated in certain lung adenocarcinomas. Menin represses PTN transcription and PTN-induced proliferation of human lung cancer cells, and menin expression is substantially reduced in primary human lung adenocarcinomas. Notably, menin binds the PTN locus and enhances Polycomb gene Enhancer of Zeste homolog 2 (EZH2)-mediated histone H3 lysine 27 trimethylation (H3K27m3), a negative mark for gene transcription but does not affect histone H3K4 methylation that is usually upregulated by menin in endocrine cells. Together, our findings indicate that menin suppresses lung cancer partly through increasing Polycomb gene-mediated H3K27 methylation and repressing PTN transcription, unraveling a novel, epigenetically regulated PTN-ALK signaling pathway in suppressing lung cancer.

Menin regulates endocrine diseases by controlling histone modification and gene transcription.

Multiple endocrine neoplasia type 1 (MEN1), a human familial tumor syndrome, results from mutations in the Men1 gene. Although much progress has been made in demonstrating the definitive role for menin in suppressing tumorigenesis in endocrine organs, the molecular pathways responsible for menin action in normal tissues and tumors remain poorly defined. Here, we review the recent progress on the molecular functions of menin in controlling cell proliferation, apoptosis, and DNA repair. The majority of these functions are largely executed by menin-mediated influencing of histone modifications and chromatin structure. These findings lead to a new model of understanding menin's tumor-suppressing function, providing insights into understanding of how menin regulates cell proliferation and the development of endocrine tumors. The new knowledge could also be translated into new strategies to improve therapeutic interventions against MEN1 and other endocrine diseases including diabetes.

Correlation of serum lipids, lipoproteins, lipid peroxide products and metals with coronary heart disease.

Serum lipids, lipoproteins, malondialdelyde (MDA) and metal levels were determined in 86 patients with coronary heart disease (CHD) proved angiographically and 33 controls subjects. Serum concentrations of TC, LDL-C, AI, MDA and Cu were significantly elevated and serum HDL-C, Zn and Mg contents were decreased markedly in patients. Correlation analyses indicated that the severity of coronary arterial lesions was related positively to serum TC, LDL-C, AI, MDA and Cu levels, and inversely to HDL-C levels; both the serum Cu and MDA contents were related positively to TC and LDL-C levels. These data suggest that serum Cu and MDA might have effects on the extent of CA lesions during the progress of atherosclerosis in patients with CHD.

[Antiarrhythmic effects of Cordyceps sinensis (Berk.) Sacc].

The administration of 65% alcohol extracts of Cordyceps sinensis can counteract the arrhythmias induced by aconitine or BaCl2 in rats, and increase the tolerant dose of ouabain to produce the arrhythmias in guinea pigs. The drug can reduce the heart rate of anesthetic rats, decreasing the contractility of isolated papillary muscle or atria in guinea pigs, but showing no effect on the automatic rhythmicity and the functional refractory period of the atria.