The calmodulin-binding transcription activators (CAMTA) play critical roles in plant growth and responses to environmental stimuli. However, how CAMTAs function in responses to abiotic and biotic stresses in maize (Zea mays L.) is largely unknown. In this study, we first identified all the CAMTA homologous genes in the whole genome of maize. The results showed that nine ZmCAMTA genes showed highly diversified gene structures and tissue-specific expression patterns. Many ZmCAMTA genes displayed high expression levels in the roots. We then surveyed the distribution of stress-related cis-regulatory elements in the −1.5 kb promoter regions of ZmCAMTA genes. Notably, a large number of stress-related elements present in the promoter regions of some ZmCAMTA genes, indicating a genetic basis of stress expression regulation of these genes. Quantitative real-time PCR was used to test the expression of ZmCAMTA genes under several abiotic stresses (drought, salt, and cold), various stress-related hormones [abscisic acid, auxin, salicylic acid (SA), and jasmonic acid] and biotic stress [rice black-streaked dwarf virus (RBSDV) infection]. Furthermore, the expression pattern of ZmCAMTA genes under RBSDV infection was analyzed to investigate their potential roles in responses of different maize cultivated varieties to RBSDV. The expression of most ZmCAMTA genes responded to both abiotic and biotic stresses. The data will help us to understand the roles of CAMTA-mediated Ca2+ signaling in maize tolerance to environmental stresses.

Circular RNAs (circRNAs) are a novel type of non-coding RNA expressed across different species and tissues. At present, little is known about the expression and function of circRNAs in the tree shrew brain. In this study, we used RNA-seq to identify 35,007 circRNAs in hippocampus and cerebellum samples from infant (aged 47–52 days), young (aged 15–18 months), and old (aged 78–86 months) tree shrews. We observed no significant changes in the total circRNA expression profiles in different brain regions over time. However, circRNA tended to be downregulated in the cerebellum over time. Real-time RT-PCR analysis verified the presence of circRNAs. KEGG analysis indicated the occurrence of ubiquitin-mediated proteolysis, the MAPK signaling pathway, phosphatidylinositol signaling system, long-term depression, the rap1 signaling pathway, and long-term potentiation in both brain regions. We also observed that 29,087 (83.1%) tree shrew circRNAs shared homology with human circRNAs. The competing endogenous RNA networks suggested novel_circRNA_007362 potential functions as a 24-miRNAs sponge to regulate UBE4B expression. Thus, we obtained comprehensive circRNA expression profiles in the tree shrew brain during postnatal development and aging, which might help to elucidate the functions of circRNAs during brain aging and in age-related diseases.

Cadmium (Cd) is a heavy metal and is highly toxic to all plant species. However, the underlying molecular mechanism controlling the effects of auxin on the Cd stress response in maize is largely unknown. In this study, the transcriptome produced by maize ‘Zheng 58’ root responses to Cd stress was sequenced using Illumina sequencing technology. In our study, six RNA-seq libraries yielded a total of 244 million clean short reads and 30.37 Gb of sequence data. A total of 6342 differentially expressed genes (DEGs) were grouped into 908 Gene Ontology (GO) categories and 198 Kyoto Encyclopedia of Genes and Genomes terms. GO term enrichment analysis indicated that various auxin signaling pathway-related GO terms were significantly enriched in DEGs. Comparison of the transcript abundances for auxin biosynthesis, transport, and downstream response genes revealed a universal expression response under Cd treatment. Furthermore, our data showed that free indole-3-acetic acid (IAA) levels were significantly reduced; but IAA oxidase activity was up-regulated after Cd treatment in maize roots. The analysis of Cd activity in maize roots under different Cd and auxin conditions confirmed that auxin affected Cd accumulation in maize seedlings. These results will improve our understanding of the complex molecular mechanisms underlying the response to Cd stress in maize roots.

Background/Aims: Cisplatin-based treatment is first-line chemotherapy for several cancers including ovarian cancer. The development of cisplatin resistance results in treatment failure, but the underlying mechanisms are not fully understood. Histone deacetylases (HDACs) are a large family of enzymes that deacetylate lysine residues on histones and non-histone proteins. High expression of HDAC1 is associated with poor outcomes in ovarian cancer. Furthermore, resistance to chemotherapeutic agents is associated with HDAC1 overexpression in ovarian cancer cells. The goals of this study were to determine whether targeting HDAC1 can sensitize ovarian cancer cells to cisplatin and to explore the underlying mechanisms. Methods: Small interfering RNA (siRNA)-targeting HDAC1 was designed to silence HDAC1 in the cisplatin-resistant ovarian cancer cell line A2780^CDDP and its cisplatin-sensitive cell line A2780. The effects of targeting HDAC1 on cell viability assay, colony formation, and apoptosis were detected. c-Myc re-expression or miR-34a inhibitors were used to examine the relationship among HDAC1, c-Myc, and miR-34a expression, which was assessed by western blot analysis and quantitative reverse transcription PCR. We established stable transfectants of A2780^CDDP/HDAC1 short hairpin RNA (shRNA) and A2780/HDAC1 shRNA. The therapeutic effectiveness of cisplatin in murine xenograft models was assessed following shRNA-mediated HDAC1 silencing in A2780^CDDP and A2780 cells. The mechanism of cell death was studied in tumor sections obtained from different mouse tumors. Results: In cisplatin-resistant A2780^CDDP cells, HDAC1 knockdown by siRNA suppressed cell proliferation, and increased apoptosis and chemosensitivity by downregulating c-Myc and upregulating miR-34a. In cisplatin-sensitive A2780 cells, HDAC1 knockdown did not affect cell proliferation and apoptosis. Cisplatin treatment activated HDAC1 and c-Myc and inactivated miR-34a. Inhibition of HDAC1 with siRNA reduced c-Myc expression, increased miR-34a expression, and sensitized A2780 cells to cisplatin-induced apoptosis. c-Myc re-expression or miR-34a targeting by miR-34a inhibitors protected cells from apoptosis or reversed cisplatin resistance following HDAC1 knockdown or/and cisplatin exposure. Finally, in vivo studies showed that targeting HDAC1 inhibited A2780^CDDP-induced xenograft tumor growth but not A2780-induced xenograft tumor growth. Targeting HDAC1 sensitized both A2780- and A2780^CDDP-induced xenograft tumors to cisplatin treatment. Conclusions: Upregulation of HDAC1 is a crucial event in the development of drug resistance to current treatments in ovarian cancer. Thus, targeting HDAC1 by enhancing c-Myc-dependent miR-34a expression might be an effective strategy for increasing the efficacy of cisplatin treatment.

Most human diseases are systems diseases, and systems biomarkers are better fitted for diagnostic, prognostic, and treatment monitoring purposes. To search for systems biomarker candidates, lactate dehydrogenase (LDH), a housekeeping protein expressed in all living cells, was investigated. To this end, we analyzed the serum LDH activities from 172,933 patients with 48 clinically defined diseases and 9528 healthy individuals. Based on the median values, we found that 46 out of 48 diseases, leading by acute myocardial infarction, had significantly increased (p < 0.001), whereas gout and cerebral ischemia had significantly decreased (p < 0.001) serum LDH activities compared to the healthy control. Remarkably, hepatic encephalopathy and lung fibrosis had the highest AUCs (0.89, 0.80), sensitivities (0.73, 0.56), and specificities (0.90, 0.91) among 48 human diseases. Statistical analysis revealed that over-downregulation of serum LDH activities was associated with blood-related cancers and diseases. LDH activities were potential systems biomarker candidates (AUCs > 0.8) for hepatic encephalopathy and lung fibrosis.