High temperature and salt stress response in French bean (Phaseolus vulgaris)

Abiotic stresses, such as high temp., and salt stress are major factors which reduce crop productivity. Effects of high temp. (46-​48° C) and salt stress (0.4 M) on French bean (Phaseolus vulgaris)​, a major vegetable crop, were evaluated in terms of antioxidants and antioxidant enzymes in S-​9 cultivar. Both stresses caused similar responses in the plant. Oxidative stress indicators such as H2O2, TBARS, glutathione, ascorbic acid, and proline were significantly elevated. Similarly, antioxidant enzyme, guaiacol-​specific peroxidase (POX) was significantly elevated. Other enzymes, β-​amylase and acid phosphatase (AP) activities were marginally enhanced. However, stresses had contrasting effects on glutathione reductase (GR) and catalase (CAT)​, which were drastically reduced in temp. stress, and elevated in salt stress. No variations were obsd. in AP, POX, and CAT isoenzymes. Patterns of GR and β-​amylase isoenzymes differed between temp. and salt stress. SDS-​PAGE indicated entirely different sets of proteins in temp. and salt stressed seedlings. Growth rate and fresh mass were affected to same extent, relative to their resp. controls. DNA damage was more pronounced under temp. stress than under salt stress. Response mechanism of French bean appears to involve some players which are common to both the stresses, and few specific to individual stress

Identification of microRNAs and their targets in Finger millet by high throughput sequencing

MicroRNAs are short non-coding RNAs which play an important role in regulating gene expression by mRNA cleavage or by translational repression. The majority of identified miRNAs were evolutionarily conserved; however, others expressed in a species-specific manner. Finger millet is an important cereal crop; nonetheless, no practical information is available on microRNAs to date. In this study, we have identified 95 conserved microRNAs belonging to 39 families and 3 novel microRNAs by high throughput sequencing. For the identified conserved and novel miRNAs a total of 507 targets were predicted. 11 miRNAs were validated and tissue specificity was determined by stem loop RT-qPCR, Northern blot. GO analyses revealed targets of miRNA were involved in wide range of regulatory functions. This study implies large number of known and novel miRNAs found in Finger millet which may play important role in growth and development. © 2015 Elsevier B.V

Genome wide analysis of NAC transcription factors and their expression pattern during high temperature and drought stress in groundnut

NAC (NAM, ATAF1/2 and CUC2) is a prime plant specific transcription factor, which plays a pivotal role in stress signaling. Excavating a relatively large number of NAC TFs under complex environmental cues and understanding their molecular basis,\ua0remains a challenge. The objective of this study was to analyse a total of 76 NAC transcription factors of which 38 were from Arachis duranensis (AdNAC) and Arachis ipaensis (AiNAC) for phylogeny, chromosomal location, conserved motif identification including membrane bound NTLs (NAC trans-membrane like), promoter analysis and expression profiles under high temperature and drought stress.\ua0The study led to the identification of eight membrane bound NTLs, such as AdNAC26, AdNAC36, AiNAC16, AiNAC17, AiNAC37, AdNAC14, AiNAC12, and AiNAC29, and revealed that majority of NAC proteins had four NAC domain- containing conserved motifs and were localised at the nucleus. The study also reveals AdNAC21 and AiNAC3 as positive regulators under both stress conditions. Our results provide a basis for selection of promising stress- responsive NAC candidates for further functional analysis, leading to development of transgenics with improved productivity of groundnut varieties under drought and high temperature.NAC (NAM, ATAF1/2 et CUC2) est un facteur sp\ue9cifique primordial dans la transcription chez la plante, qui joue un r\uf4le principal dans la signalisation des stresses. Fouiller un nombre relativement important de NAC TFs sous le complexe des signaux environnementaux et comprendre leur base mol\ue9culaire, demeurent un d\ue9fi. L\u2019objectif de cette \ue9tude \ue9tait d\u2019analyser un total de 76 facteurs de transcription desquels 38 sont de Arachis duranensis (AdNAC) et Arachis ipaensis (AiNAC) pour la phylog\ue9nie, la localisation chromosomique, l\u2019identification du motif conserv\ue9 y comprises la membrane li\ue9e NTLs (semblable \ue0 NAC transe-membrane), analyse du promoteur et les profils d\u2019expression sous le stress de haute temp\ue9rature et de s\ue9cheresse. L\u2019\ue9tude a conduit \ue0 l\u2019identification de huit membranes NTLs li\ue9es, telles que AdNAC26, AdNAC36, AiNAC16, AiNAC17, AiNAC37, AdNAC14, AiNAC12, et AiNAC29, et a r\ue9v\ue9l\ue9 que la majorit\ue9 des prot\ue9ines NAC ont quatre domaines NAC- contenant des motifs conserv\ue9s et sont localis\ue9s dans le noyau. L\u2019\ue9tude a aussi r\ue9v\ue9l\ue9 AdNAC21 et AiNAC3 comme r\ue9gulateurs positifs sous les deux conditions \ue0 la fois. Nos r\ue9sultats ont fourni une base pour la s\ue9lection des NAC candidats donnant de r\ue9ponses satisfaisantes aux stresses pour une analyse fonctionnelle avanc\ue9e, conduisant au d\ue9veloppement des transg\ue9niques avec des vari\ue9t\ue9s d\u2019arachide \ue0 rendement am\ue9lior\ue9 sous la s\ue9cheresse et une haute temp\ue9rature

Interplay of nuclear receptors (ER, PR, and GR) and their steroid hormones in MCF-7 cells

Steroid hormones and their nuclear receptors play a major role in the development and progression of breast cancer. MCF-7 cells are triple-positive breast cancer cells expressing estrogen receptor (ER), progesterone receptor (PR), and glucocorticoid receptor (GR). However, interaction and their role in expression pattern of activator protein (AP-1) transcription factors (TFs) are not completely understood. Hence, in our study, MCF-7 cells were used as an in vitro model system to study the interplay between the receptors and hormones. MCF-7 cells were treated with estradiol-17β (E2), progesterone (P4), and dexamethasone (Dex), alone or in combination, to study the proliferation of cells and expression of AP-1 genes. MTT assay results show that E2 or P4 induced the cell proliferation by more than 35 %, and Dex decreased the proliferation by 26 %. E2 and P4 are found to increase ERα by more than twofold and c-Jun, c-Fos, and Fra-1 AP-1 TFs by more than 1.7-fold, while Dex shows opposite effect of E2- or P4-induced effect as well as effect on the expression of nuclear receptors and AP-1 factors. E2 antagonist Fulvestrant (ICI 182,780) found to reduce proliferation and E2-induced expression of AP1-TFs, while P4 or Dex antagonist Mifepristone (RU486) is found to block GR-mediated expression of NRs and AP-1 mRNAs. Results suggest that E2 and P4 act synergistically, and Dex acts as an antagonist of E2 and P4

Aqueous areca nut extract induces oxidative stress in human lung epithelial A549 cells: Probable role of p21 in inducing cell death

Areca nut a well-known masticator used across globe. Habitual chewing of areca nut is associated with serious oral health effects. However, the role of areca nut in oxidative stress induction and cell death is less understood. Hence, in the present study we aimed to evaluate the toxic mechanism of areca nut extract on human lung epithelial A549 cells. Cells were treated with or without aqueous areca nut extract and cell viability was measured by MTT assay. Cells treated with areca nut extract show reduced viability in a dose dependent manner with the IC50 of 0.5 concentration. Areca nut extract induced the reactive oxygen species (ROS), lipid peroxidation followed by membrane damage with leakage of lactate dehydrogenase (LDH) enzyme. Cells with continuous exposure of areca nut extract depletes the free radical neutralizing anti-oxidant enzymes like superoxide dismutase (SOD), Glutathione peroxidase (GSH-Px) and Glutathione-S-transferase (GST). Further, the analysis of mRNA expression of apoptotic genes and cell cycle regulators show decreased expression of anti-apoptotic gene (Bcl-2), Cyclin E1, Cyclin D1, CDK4, Rb and p53 whereas induced expression of p21 and marginal increase of pro-apoptotic gene (Bax) confirms the toxic nature of areca nut. Thus, cell death due to areca nut exposure may be through different mechanism rather than the conventional apoptotic pathway, where p21 induction might be independent of p53 action, which possibly suggests that there may be a role of p21 in oxidative stress induced cell death. Further FACS analysis confirms cell death in areca nut treated cells. © 2016 Elsevier Inc

Cadmium induces oxidative stress and apoptosis in lung epithelial cells

Cadmium (Cd) is one of the well-known highly toxic environmental and industrial pollutants. Cd first accumulates in the nucleus and later interacts with zinc finger proteins of antiapoptotic genes and inhibit the binding of transcriptional factors and transcription. However, the role of Cd in oxidative stress and apoptosis is less understood. Hence, the present study was undertaken to unveil the mechanism of action. A549 cells were treated with or without Cd and cell viability was measured by MTT assay. Treatment of cells with Cd shows reduced viability in a dose-dependent manner with IC50 of 45 μM concentration. Cd significantly induces the reactive oxygen species (ROS), lipid peroxidation followed by membrane damage with the leakage of lactate dehydrogenase (LDH). Cells with continuous exposure of Cd deplete the antioxidant super oxide dismutase (SOD) and glutathione peroxidase (GSH-Px) enzymes. Further, analysis of the expression of genes involved in apoptosis show that both the extrinsic and intrinsic apoptotic pathways were involved. Death receptor marker tumor necrosis factor-α (TNF-α), executor caspase-8 and pro-apoptotic gene (Bax) were induced, while antiapoptotic gene (Bcl-2) was decreased in Cd-treated cells. Fluorescence-activated cell sorting (FACS) analysis further confirms the induction of apoptosis in Cd-treated A549 cells

Differential expression of AP-1 transcription factors in human prostate LNCaP and PC-3 cells: role of Fra-1 in transition to CRPC status

Androgen receptor (AR) signaling axis plays a vital role in the development of prostate and critical in the progression of prostate cancer. Androgen withdrawal initially regresses tumors but eventually develops into aggressive castration-resistant prostate cancer (CRPC). Activator Protein-1 (AP-1) transcription factors are most likely to be associated with malignant transformation in prostate cancer. Hence, to determine the implication of AR and AP-1 in promoting the transition of prostate cancer to the androgen-independent state, we used AR-positive LNCaP and AR-negative PC-3 cells as an in vitro model system. The effect of dihydrotestosterone or anti-androgen bicalutamide on the cell proliferation and viability was assessed by MTT assay. Expression studies on AR, marker genes-PSA, TMPRSS2, and different AP-1 factors were analyzed by semi-quantitative RT-PCR and expressions of AR and Fra-1 proteins were analyzed by Western blotting. Dihydrotestosterone induced the cell proliferation in LNCaP with no effect on PC-3 cells. Bicalutamide decreased the viability of both LNCaP and PC-3 cells. Dihydrotestosterone induced the expression of AR, PSA, c-Jun, and Fra-1 in LNCaP cells, and it was c-Jun and c-Fos in case of PC-3 cells, while bicalutamide decreased their expression. In addition, constitutive activation and non-regulation of Fra-1 by bicalutamide in PC-3 cells suggested that Fra-1, probably a key component, involved in transition of aggressive androgen-independent PC-3 cells with poor prognosis. © 2017, Springer Science+Business Media New York

Effect of Daily Chewing Soft Buds and Leaves of Catha edulis (Khat) on the Antioxidant Defense System and Oxidative Stress Markers in Blood

Catha edulis (Khat) is one of the major economic, social and health problems in Yemen. This paper aimed to study the effect of Khat on the oxidative status of Khat chewers by measuring the levels of enzymatic and non-enzymatic antioxidant as well as lipid peroxidation. The results exhibited significant reduction in erythrocytes superoxide dismutase (SOD, EC: 1.15.1.1), and catalase (CAT, EC: 1.11.1.6) in Khat chewers, in addition to elevation of serum glutathione-S-transferase (GST, EC: 2.5.1.18). Furthermore, non-enzymatic antioxidants glutathione (GSH) and vitamin C were significantly reduced (p < 0.001; p < 0.015), whereas malondialdehyde (MDA) was significantly elevated (p < 0.001). The depletion of GSH and vitamin C along with MDA elevation in Khat chewers compared with control reflects the obvious oxidative status, a result of enormous reactive oxygen species (ROS) formation, leading to membrane damage. ROS possibly induced by active components of Khat or by pesticides added to the Khat tree. In addition, the reduction of SOD and CAT is indicative to cellular proteins damage which occurred by ROS. As well, the elevation of GST may due to a leakage of cellular GST to blood stream; this implies that GST active site was not affected. This study concludes that daily chewing Khat for long period certainly induce ROS production, leading to oxidative toxicity. Both enzymatic and non-enzymatic antioxidants are involved in the protection against this toxicity. People who habitually chew Khat for long term will be susceptible to the oxidative toxicity; therefore, they recommended giving up of Khat chewing

Protein kinases orchestrate cell cycle regulators in differentiating BeWo choriocarcinoma cells

Abstract Choriocarcinoma, a trophoblastic neoplasia, occurs in women as an incidence of abnormal pregnancy. BeWo choriocarcinoma cells derived from the abnormal placentation are a suitable model system to study the factors associated with differentiation, invasion and other cellular events as an alternative to clinical samples. Many protein kinases orchestrate the complex events of cell cycle and in case of malignancy such regulators are found to be mutated. In the present study, BeWo cells treated with forskolin (Fo) and phorbol 12-myristate 13-acetate (PMA) were used to study the role of PKA (protein kinase A) and PKC (protein kinase C), respectively, on the expression pattern of differentiation-related genes, membrane markers, PKC isoforms and cell cycle regulators. The effect of Fo and PMA on the cell proliferation was assessed. Progressive induction of alkaline phosphatase level and formation of multinucleated differentiated cells were observed in the cells treated with Fo. Exposure of cells to Fo and PMA induced the mRNA transcripts of α-hCG, β-hCG and endoglin and down-regulates E-cadherin at mRNA and protein levels. Synergistic levels of both up- and down-regulated genes/proteins were observed when cells were treated with the combination of Fo and PMA. The mRNA levels of cyclin D1, cyclin E1, p21, Rb, p53, caspase-3 and caspase-8 decreased gradually during differentiation. Fo significantly inhibited the protein levels of PCNA, Rb, PKC-α and PMA stimulated mRNA expression of PKC-ε and PKC-δ. Further, failure in the activation of essential components of the cell cycle machinery caused G2/M phase arrest in differentiating BeWo cells