Ethylene Acts as a Local and Systemic Signal to Mediate UV-B-Induced Nitrate Reallocation to Arabidopsis Leaves and Roots via Regulating the ERFs-NRT1.8 Signaling Module.

Nitrate is the preferred nitrogen source for plants and plays an important role in plant growth and development. Under various soil stresses, plants reallocate nitrate to roots to promote stress tolerance through the ethylene-ethylene response factors (ERFs)-nitrate transporter (NRT) signaling module. As a light signal, ultraviolet B (UV-B) also stimulates the production of ethylene. However, whether UV-B regulates nitrate reallocation in plants via ethylene remains unknown. Here, we found that UV-B-induced expression of ERF1B, ORA59, ERF104, and NRT1.8 in both Arabidopsis shoots and roots as well as nitrate reallocation from hypocotyls to leaves and roots were impaired in ethylene signaling mutants for Ethylene Insensitive2 (EIN2) and EIN3. UV-B-induced NRT1.8 expression and nitrate reallocation to leaves and roots were also inhibited in the triple mutants for ERF1B, ORA59, and ERF104. Deletion of NRT1.8 impaired UV-B-induced nitrate reallocation to both leaves and roots. Furthermore, UV-B promoted ethylene release in both shoots and roots by enhancing the gene expression and enzymatic activities of ethylene biosynthetic enzymes only in shoots. These results show that ethylene acts as a local and systemic signal to mediate UV-B-induced nitrate reallocation from Arabidopsis hypocotyls to both leaves and roots via regulating the gene expression of the ERFs-NRT1.8 signaling module.

A novel multiplex qPCR method for assessing the comparative lengths of telomeres.

BACKGROUND: The comparative length of telomeres is considered to be related to diseases such as cancer, aging, and cardiovascular diseases. qPCR is currently one of the main methods for detecting telomere length. However, due to the unique sequence of telomeres (highly repetitive six-base sequence), it is difficult to design primers and probes to expand and detect telomere and to put internal reference gene and telomere into the same tube for detection to reduce the possible inter-pore errors and improve amplification efficiency. Besides, the stability and accuracy of the test results are greatly affected by the difference between reference genes and telomere copy number. METHODS: In this study, the single-copy genes were replaced with high-copy genes (300 copies) as the internal control to reduce the copy number difference of the internal genes and telomere. In addition, a multiplex qPCR system was constructed to detect the telomeres and an internal reference gene product. We also detected the lengths of telomeres in the genomic DNA in immortalized cells (293T and Hela) from different generations of cells. RESULTS: We detected the comparative telomere lengths of 1500 random Chinese volunteers of different ages with the multiplex qPCR method; the result shows that the comparative length of telomeres is negatively related to age. In addition, we compared our qPCR detection method with a terminal restriction fragmentation (TRF) method. Both of them were highly consistent, indicating that the qPCR method was reliable. CONCLUSIONS: In conclusion, we developed a stable, convenient, and accurate comparative telomere length detection method.

A novel multiplex fluorescent competitive PCR for copy number variation detection.

The copy number variation (CNV) is an important genetic marker in cancer and other diseases. To detect CNVs of specific genetic loci, the multiplex ligation-dependent probe amplification (MLPA) is an appropriate approach, but the experimental optimization and probe synthesis are still great challenges. The multiplex competitive PCR is an alternative method for CNV detection. However, the construction of internal competitive template and establishment of a stable multiplex PCR system are the main limiting factors for this method. Here, we introduce a novel multiplex fluorescent competitive PCR (NMFC-PCR) for detecting CNVs. In this method, the blunt hairpin primers are used to rapidly establish a stable multiplex PCR system due to the reduction of non-specific amplification, and limited cycles' amplification is used to obtain the internal competitive template instead of artificial synthesis. With this method, we tested 21 clinical samples with potential LIM homeobox 1 (LHX1) or T-box 6 (TBX6) deletion. Every three segments located on the LHX1 and TBX6 were selected as the target regions, while two segments located on X-chromosome and five segments located on autosome were selected as the reference regions for detecting CNVs. The results showed that the gender information of 21 samples can be accurately inferred by the copy number ratio (CNR) of X-chromosomal reference region to autosomal reference region (X/A), and 2 samples had one copy of LHX1 and 9 samples had one copy of TBX6. To evaluate the accuracy of NMFC-PCR, 5 random samples with CNV were also detected by array-based comparative genomic hybridization (aCGH), and the results of aCGH were consistent with the NMFC-PCR results. To further assess the performance of NMFC-PCR, 60 normal samples were simultaneously tested. The results showed that the gender results were exactly the same as known information, and CNVs of LHX1 or TBX6 were not found. In conclusion, the method is a cheap, efficient, accurate, and convenient competitive PCR method for CNV detection.

MicroRNA­449a is a potential predictor of colitis­associated colorectal cancer progression.

An early diagnosis of colitis­associated colorectal cancer (CAC) is important for its clinical management. However, it is currently difficult to distinguish the different stages of CAC development. MicroRNA dysregulation is common in human colorectal disorders, however little is known regarding whether miRNA affects tumor progression by regulating inflammation. In the present study, we identified a novel miRNA (miR­449a), the expression of which was significantly reduced in CAC tissues than in paired adjacent non­cancerous tissues (ANTs). Notably, the level of miR­449a was in a markedly decreased pattern during the neoplastic transformation of ulcerative colitis (UC)­to­CAC, as demonstrated by both clinical investigations and the experimental mouse model induced by AOM/DSS treatment. In addition, we observed that decreased miR­449a expression was associated with advanced T or N status, later clinical stage and poor histological differentiation of CAC. Mechanistic studies revealed that miR­449a inhibited the growth and metastasis of human colon cancer cells by directly binding to the 3'­UTR of Notch­1 and thereby, suppressed the activation of the Notch signaling pathway. Therefore, these findings provide strong evidence for the translational potential of miR­449a in the discrimination of patients with UC that is likely to progress into CAC, from those unlikely to progress, as well as in the prognosis and diagnosis of CAC.

Emerging Role of MicroRNAs and Long Noncoding RNAs in Healthy and Diseased Lung.

Pulmonary hypertension (PH) is a complex and multifactorial disease. An inability to fully unravel the molecular complexities has led to various clinical challenges in developing new therapies for this disease. Noncoding RNAs (ncRNAs) are RNA molecules with limited ability of coding proteins. The amount of ncRNAs is up to 98% of the whole genome's transcripts. Many ncRNAs with a regulatory function of genes have been identified to date and found to act at various steps along the protein biosynthetic process, which includes transcription, RNA maturation, translation, and protein degradation. These discoveries are fueling a new era in understanding the pathophysiology and therapeutic pathways of PH. In this chapter, we discuss the emerging role of noncoding RNAs in PH as well as other pulmonary diseases.

Deregulated expression of Cdc6 as BCR/ABL-dependent survival factor in chronic myeloid leukemia cells.

Chronic myeloid leukemia is characterized by the presence of the reciprocal translocation t(9;22) and the BCR/ABL oncogene. The BCR/ABL oncogene activates multiple signaling pathways and involves the dysregulation of oncogenes during the progression of chronic myeloid leukemia. The cell division cycle protein 6, an essential regulator of DNA replication, is elevated in some human cancer cells. However, the expression of cell division cycle protein 6 in chronic myeloid leukemia and the underlying regulatory mechanism remain to be elucidated. In this study, our data showed that cell division cycle protein 6 expression was significantly upregulated in primary chronic myeloid leukemia cells and the chronic myeloid leukemia cell line K562 cells, as compared to the normal bone marrow mononuclear cells. BCR/ABL kinase inhibitor STI571 or BCR/ABL small interfering RNA could significantly downregulate cell division cycle protein 6 messenger RNA expression in K562 cells. Moreover, phosphoinositide 3-kinase/AKT pathway inhibitor LY294002 and Janus kinase/signal transducer and activator of transcription pathway inhibitor AG490 could downregulate cell division cycle protein 6 expression in K562 cells, but not RAS/mitogen-activated protein kinase pathway inhibitor PD98059 had such effect. Cell division cycle protein 6 gene silencing by small interfering RNA effectively resulted in decrease of proliferation, increase of apoptosis, and arrest of cell cycle in K562 cells. These findings have demonstrated that cell division cycle protein 6 overexpression may contribute to the high proliferation and low apoptosis in chronic myeloid leukemia cells and can be regulated by BCR/ABL signal transduction through downstream phosphoinositide 3-kinase/Akt and Janus kinase/signal transducer and activator of transcription pathways, suggesting cell division cycle protein 6 as a potential therapeutic target in chronic myeloid leukemia.

MicroRNA-155 promotes the pathogenesis of experimental colitis by repressing SHIP-1 expression.

AIM: To explore the mechanism by which microRNA-155 (miR-155) regulates the pathogenesis of experimental colitis. METHODS: A luciferase assay was performed to confirm the binding of miR-155 to the SHIP-1 3'-UTR. MiR-155 mimics, negative controls and SHIP-1 expression/knockdown vectors were established and then utilized in gain- and loss-of-function studies performed in raw264.7 cells and primary bone marrow-derived macrophages (BMDMs). Thereafter, dextran sulfate sodium (DSS)-induced colitis mouse model with or without antagomiR-155 treatment was established, and the levels of miR-155 and SHIP-1, as well as the pro-inflammatory capabilities, were measured by western blot, quantitative polymerase chain reaction, and immunohistochemistry. RESULTS: MiR-155 directly bound to the 3'-UTR of SHIP-1 mRNA and induced a significant decrease in SHIP-1 expression in both raw264.7 cells and primary BMDMs. MiR-155 markedly promoted cell proliferation and pro-inflammatory secretions including IL-6, TNF-α, IL-1ß, and IFN-γ, whereas these effects could be reversed by the restoration of SHIP-1 expression. In vivo studies showed that antagomiR-155 administration could alleviate DSS-induced intestinal inflammation in Balb/c mice. Moreover, significantly increased SHIP-1 expression, as well as decreased Akt activation and inflammatory response, were observed in the antagomiR-155-treated mice. CONCLUSION: MiR-155 promotes experimental colitis by repressing SHIP-1 expression. Thus, the inhibition of miR-155 might be a promising strategy for therapy.

ceRNA in cancer: possible functions and clinical implications.

Competing endogenous RNAs (ceRNAs) are transcripts that can regulate each other at post-transcription level by competing for shared miRNAs. CeRNA networks link the function of protein-coding mRNAs with that of non-coding RNAs such as microRNA, long non-coding RNA, pseudogenic RNA and circular RNA. Given that any transcripts harbouring miRNA response element can theoretically function as ceRNAs, they may represent a widespread form of post-transcriptional regulation of gene expression in both physiology and pathology. CeRNA activity is influenced by multiple factors such as the abundance and subcellular localisation of ceRNA components, binding affinity of miRNAs to their sponges, RNA editing, RNA secondary structures and RNA-binding proteins. Aberrations in these factors may deregulate ceRNA networks and thus lead to human diseases including cancer. In this review, we introduce the mechanisms and molecular bases of ceRNA networks, discuss their roles in the pathogenesis of cancer as well as methods of predicting and validating ceRNA interplay. At last, we discuss the limitations of current ceRNA theory, propose possible directions and envision the possibilities of ceRNAs as diagnostic biomarkers or therapeutic targets.

Efficacy and safety of adalimumab for the Crohn's disease: a systematic review and meta-analysis of published randomized placebo-controlled trials.

PURPOSE: The aim of this study was to evaluate the efficacy and safety of adalimumab (ADA) for Crohn's disease. METHODS: Electronic databases, including PubMed, Embase, the Cochrane Library, and the Science Citation Index, were searched to retrieve relevant trials. We estimated pooled estimates of the odds ratio (OR) and relevant 95% confidence interval (CI) using fixed effects model or random effects model as appropriate. RESULTS: Six randomized placebo-controlled studies met the selection criteria. Short-term clinical response/remission and long-term remission were better in the ADA groups than in the control groups (P < 0.05), both in anti-TNF-naive patients and in subjects who lost their response and/or became intolerant to infliximab (IFX). And ADA was also effective for patients who were previously treated with IFX, and its efficacy in infliximab-exposed patients was probably less than in infliximab-naive patients. In patients with active Crohn's disease (CD), ADA therapy was more effective than placebo for obtaining complete fistula closure. In comparison with placebo, ADA does not increase the risk of serious adverse events. CONCLUSIONS: ADA appears to be effective in achieving short-term clinical response/remission, long-term remission, and complete fistula healing in CD, including patients not manageable with IFX, and appears to have a favorable safety profile. A longer duration of follow-up and a larger number of patients are required to better assess the safety profile of ADA in CD.

Distinct activity of BK channel ß1-subunit in cerebral and pulmonary artery smooth muscle cells.

This study was designed to test a hypothesis that the functional activity of big-conductance, Ca(2+)-activated K(+) (BK) channels is different in cerebral and pulmonary artery smooth muscle cells (CASMCs and PASMCs). Using patch-clamp recordings, we found that the activity of whole cell and single BK channels were significantly higher in CASMCs than in PASMCs. The voltage and Ca(2+) sensitivity of BK channels were greater in CASMCs than in PASMCs. Targeted gene knockout of ß(1)-subunits significantly reduced BK currents in CASMCs but had no effect in PASMCs. Western blotting experiments revealed that BK channel α-subunit protein expression level was comparable in CASMCs and PASMCs; however, ß(1)-subunit protein expression level was higher in CASMCs than in PASMCs. Inhibition of BK channels by the specific blocker iberiotoxin enhanced norepinephrine-induced increase in intracellular calcium concentration in CASMCs but not in PASMCs. Systemic artery blood pressure was elevated in ß(1)(-/-) mice. In contrast, pulmonary artery blood pressure was normal in ß(1)(-/-) mice. These findings provide the first evidence that the activity of BK channels is higher in cerebral than in PASMCs. This heterogeneity is primarily determined by the differential ß(1)-subunit function and contributes to diverse cellular responses in these two distinct types of cells.

Simultaneous detection of hepatitis B virus genotypes and mutations associated with resistance to lamivudine, adefovir, and telbivudine by the polymerase chain reaction-ligase detection reaction

OBJECTIVES: Detection of mutations associated to nucleos(t)ide analogs and hepatitis B virus (HBV) genotyping are essential for monitoring treatment of HBV infection. We developed a multiplex polymerase chain reaction-ligase detection reaction (PCR-LDR) assay for the rapid detection of HBV genotypes and mutations associated with lamivudine, adefovir, and telbivudine resistance in HBV-infected patients. METHODS: HBV templates were amplified by PCR, followed by LDR and electrophoresis on a sequencer. The assay was evaluated using plasmids that contained wild-type or mutant HBV sequences and 216 clinical samples. RESULTS: The PCR-LDR assay and sequencing gave comparable results for 158 of the 216 samples (73.1 percent) with respect to mutation detection and genotyping. Complete agreement between the two methods was observed for all the samples (100 percent) at codon 180 and codon 204. Concordant results were observed for 99.4 percent of the 158 samples at codon 181 and 98.7 percent at codon 236. The genotyping results were completely concordant between the PCR-LDR assay and sequencing. The PCR-LDR assay could detect a proportion of 1 percent mutant plasmid in a background of wild-type plasmid. CONCLUSION: The PCR-LDR assay is sensitive and specific for detection of HBV genotypes and drug resistance mutations, and could be helpful for decision making in the treatment of HBV infection.

Beneficial effects of THSG on acetic acid-induced experimental colitis: involvement of upregulation of PPAR-γ and inhibition of the Nf-Κb inflammatory pathway.

The polyphenolic compound 2,3,5,4'-tetrahydroxystilbene-2-O-beta-D-glucoside (THSG) has been shown to possess anti-inflammatory effects. Here, we examined the effects of THSG on experimental mice with colitis induced by acetic acid and whether the underlying mechanisms were associated with the PPAR-γ and NF-κB pathways. Mice were randomized into six equal groups: normal, colitis model, THSG (10, 30, 60 mg·kg(-1)) and mesalazine. The mice were administered 10, 30, 60 mg·kg(-1) THSG or 100 mg·kg-1 mesalazine or saline once daily by intragastric administration for 7 days after induction of colitis by acetic acid irrigation. THSG dramatically attenuated acetic acid-induced colon lesions, including reversing the body weight loss and improving histopathological changes. THSG apparently decreased the increase of malondialdehyde (MDA) which is a marker of lipid peroxidation. THSG appears to exert its beneficial effects on acetic acid-induced experimental colitis through upregulation of PPAR-γ mRNA and protein levels and inhibition of the NF-κB pathway, which in turn decreases the protein overexpression of the downstream inflammatory mediators TNF-α, IL-6 and COX-2. The effect of THSG 60 mg·kg(-1) on PPAR-γ mRNA expression was higher than that of mesalazine. THSG may thus be a promising new candidate or lead compound for the treatment of IBD.

Effects of isoliensinine on proliferation of porcine coronary arterial smooth muscle cells induced by phenylephrine.

AIM: To investigate the inhibitory effects and mechanism of action of isoliensinine (IL) on the proliferation of porcine coronary arterial smooth muscle cells (CASMCs) induced by phenylephrine (Phen) and its mechanisms of action. METHODS: MTT assay, immunohistochemical method and Western blotting were adopted. RESULTS: IL (0.03 - 3 micromol x L(-1)) could inhibit the CASMCs proliferation induced by Phen (0.1 micromol x L(-1)) in a concentration-dependent manner. IL (0.1 micromol x L(-1)) antagonized Phen-induced overexpression of PDGF-beta and bFGF from 0.545 +/- 0.026 and 0.47 +/- 0.03 to 0.458 +/- 0.019 and 0.376 +/- 0.017 (P < 0.01 , P < 0.01). IL (0.1 micromol x L(-1)) also decreased c-fos, c-myc and hsp70 overexpression induced by Phen from 0.57 +/- 0.04, 0.44 +/- 0.04 and (173 +/- 36)% to 0.46 +/- 0.05, 0.372 +/- 0.021 and (115 +/- 35)% respectively (P < 0.01, P < 0.01, P < 0.01). CONCLUSION: IL exerted antiproliferative effect on CASMCs induced by phenylephrine, and its mechanisms were related to decrease the overexpression of growth factors (PDGF-beta, bFGF), protooncogene (c-fos, c-myc) and hsp70.

Homocysteine inhibits store-mediated calcium entry in human endothelial cells: evidence for involvement of membrane potential and actin cytoskeleton.

The role of homocysteine for store-operated calcium influx was investigated in human umbilical cord endothelial cell line. Homocysteine significantly decreased thapsigargin-evoked Ca2+ entry, membrane hyperpolarization and actin polymerization. GSH and DTT prevented homocysteine-induced inhibition of thapsigargin-evoked Ca2+ entry, membrane hyperpolarization and actin polymerization; while GSSG had the opposite effect. Homocysteine blocked large conductance Ca2+-activated K+ (BK(Ca)) channels in a concentration-dependent manner and related to the redox status of the endothelial cells. BK(Ca) channels opener NS1619 reversed thapsigargin-evoked Ca2+ entry, membrane hyperpolarization and actin polymerization; BK(Ca) channels inhibitor iberiotoxin had the opposite effect. The findings suggest that homocysteine is involved in store-regulated Ca2+ entry through membrane potential-dependent and actin cytoskeleton-dependent mechanisms, redox status of homocysteine and BK(Ca) channels may play a regulatory role in it.

Inhibitory effects of isoliensinine on bleomycin-induced pulmonary fibrosis in mice.

The effects of isoliensinine (IL), a bisbenzylisoquinoline alkaloid extracted from the Chinese traditional medicine seed embryo of Nelumbo nucifera Gaertn., on bleomycin (BLM)-induced pulmonary fibrosis in mice were investigated. Seventy-two male Kungming mice were divided randomly into eight groups as BLM-IL10, BLM-IL20, BLM-IL40, BLM-Sal, Sal-IL10, Sal-IL20, Sal-IL40 and Sal-Sal groups. BLM (0.1 mg in 0.05 ml saline per animal, once) or saline (0.05 ml per animal, once) was applied intratracheally, and IL (10, 20, 40 mg/kg) or saline was administered orally 3 times per day in the appropriate groups. Animals were sacrificed 14 days after intratracheal treatment. Lung tissue and serum superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels, tumor necrosis factor alpha (TNF-alpha) and transforming growth factor beta 1 (TGF-beta (1)) were determined by biochemical measurements and immunohistochemistry. BLM treatment resulted in a significant increase of the hydroxyproline content and an obvious lung histological injury as compared to the Sal-Sal group. Administration of IL remarkably suppressed the increase in hydroxyproline content and abated the lung histological injury induced by BLM. There was a decrease in SOD activity and an increase in MDA level in lung tissue and serum in the BLM-Sal group (p < 0.01 , p < 0.01, vs. Sal-Sal group, respectively). And IL could obviously enhance the SOD activity and decrease the MDA level in a concentration-dependent manner. Moreover, IL also significantly inhibited the overexpression of TNF-alpha and TGF-beta (1) induced by BLM. These results indicated that IL possessed a significant inhibitory effect on BLM-induced pulmonary fibrosis, probably due to its antioxidant and/or anti-inflammatory activities and inhibitory overexpressing TNF-alpha and TGF-beta (1) induced by BLM.