Can Ethylene Inhibitors Enhance the Success of Olive Somatic Embryogenesis?

An efficient in vitro morphogenesis, specifically through somatic embryogenesis, is considered to be a crucial step for the application of modern biotechnological tools for genetic improvement in olive (Olea europaea L.). The effects of different ethylene inhibitors, i.e., cobalt chloride (CoCl2), salicylic acid (SA), and silver nitrate (AgNO3), were reported in the cyclic somatic embryogenesis of olive. Embryogenic callus derived from the olive immature zygotic embryos of the cultivar Leccino, was transferred to the expression ECO medium, supplemented with the ethylene inhibitors at 20 and 40 µM concentrations. Among these, the maximum number of somatic embryos (18.6) was obtained in media containing silver nitrate (40 µM), followed by cobalt chloride (12.2 somatic embryos @ 40 µM) and salicylic acid (40 µM), which produced 8.5 somatic embryos. These compounds interfered on callus traits: white friable embryogenic calli were formed in a medium supplemented with 40 µM cobalt chloride and salicylic acid; in addition, a yellow-compact embryogenic callus appeared at 20 µM of all the tested ethylene inhibitors. The resulting stimulatory action of silver nitrate among all the tested ethylene inhibitors on somatic embryogenesis, clearly demonstrates that our approach can efficiently contribute to the improvement of the current SE protocols for olive.

Cardioprotective effects of alantolactone on isoproterenol-induced cardiac injury and cobalt chloride-induced cardiomyocyte injury

Objectives Alantolactone (AL) is a compound extracted from the roots of Inula Racemosa that has shown beneficial effects in cardiovascular disease. However, the cardioprotective mechanism of AL against hypoxic/ischemic (H/I) injury is still unclear. This research aimed to determine AL’s ability to protect the heart against isoproterenol (ISO)-induced MI injury in vivo and cobalt chloride (CoCl2) induced H/I injury in vitro. Methods Electrocardiography (ECG), lactate dehydrogenase (LDH), creatine kinase (CK), and cardiac troponin I (cTnI) assays in addition to histological analysis of the myocardium were used to investigate the effects of AL in vivo. Influences of AL on L-type Ca2+ current (ICa-L) in isolated rat myocytes were observed by the patch-clamp technique. Furthermore, cell viability, apoptosis, oxidative stress injury, mitochondrial membrane potential, and intracellular Ca2+ concentration were examined in vitro. Results The results indicated that AL treatment ameliorated the morphological and ECG changes associated with MI, and decreased levels of LDH, CK, and cTnI. Furthermore, pretreatment with AL elevated antioxidant enzyme activity and suppressed ROS production. AL prevented H/I-induced apoptosis, mitochondria damage, and calcium overload while reducing ICa-L in a concentration and time dependent fashion. The 50% inhibiting concentration (IC50) and maximal inhibitory effect (Emax) of AL were 17.29 μmol/L and 57.73 ± 1.05%, respectively. Conclusion AL attenuated MI-related injury by reducing oxidative stress, apoptosis, calcium overload, and mitochondria damage. These cardioprotective effects may be related to the direct inhibition of ICa-L.

Economic Analysis of Parawilt Management in Bt-Cotton (Gossypium hirsutum L.) in Mansa District of South-western Punjab, India

Parawilt characterized by a sudden drooping of leaves followed by death of plants withinfew hours after rainfall or heavy irrigation has been the major physiological disorder affectingproductivity of Bt-Cotton (Gossypium hirsutum L.). We studied the effect of foliarapplication of cobalt chloride (@10 mg L-1 water) within 24-36 hours after appearance ofsymptoms on recovery rate, seed cotton yield and economics at farmers’ fields in Mansadistrict of south-western Punjab. The results of front line demonstrations revealed thatfoliar application of cobalt chloride resulted in significantly (p<0.05) higher seed cottonyield by ~9.1 per cent, compared with the control (no-spray). The mean gross returns(MGRs) increased significantly by Rs. 9620/- ha-1 in the demonstration plots. The higherbenefit-cost (B:C) ratio of 2.38 was observed for the demonstration plots, against 2.15 forthe control (no-spray). The foliar application of cobalt chloride resulted in higher averageproduction efficiency of 1.1 kg seed cotton yield ha-1 d-1 and average economic efficiencyof Rs. 65.7 ha-1 d-1, compared with the control. These results therefore, revealed that farmerscan effectively manage parawilt in Bt-cotton using foliar application of cobalt chloride andmay increase seed cotton yield and economic returns.

Expression of Otx Genes in Müller Cells Using an In Vitro Experimental Model of Retinal Hypoxia

Introduction. Müller glial cells typically activate to react to hypoxic tissue damage in several retinal diseases. We evaluated the in vitro response to a hypoxia-mimicking stimulus on the expression of a set of genes, known to contribute to eye morphogenesis and cell differentiation. Materials and Methods. A MIO-M1 Müller cell line was cultured in a hypoxia-mimicking environment by the addition of cobalt chloride to the culture medium, followed by a recovery time in which we mimic restoration from the hypoxic insult. The HIF-1α protein and VEGF-A gene expression were quantified to verify the induction of a hypoxia-like state. Results. Among the genes under study, we did not observe any difference in the expression levels of Otx1 and Otx2 during treatment; conversely, Otx1 was overexpressed during recovery steps. The VEGF-A gene was strongly upregulated at both the CoCl2 and recovery time points. The transactivated isoform (TA) of the TP73 gene showed an overexpression in long-term exposure to the hypoxic stimulus with a further increase after recovery. Discussion. Our molecular analysis is able to describe the activation of a set of genes, never before described, that can drive the response to a hypoxia-like status. The improved comprehension of these cellular events will be useful for designing new therapeutical approaches for retinal pathologies.

Effects of Exogenous Ethylene and Cobalt Chloride on Root Growth of Chinese Fir Seedlings under Phosphorus-Deficient Conditions

Studying the effects of different concentrations of ethephon on morphological and physiological changes in the roots of Chinese fir (Cunninghamia lanceolata Lamb. Hook.) seedlings under P deficiency can reveal the internal adaptive mechanisms of these plants under nutrient stress. Herein, we investigated the effects of different ethephon and cobalt chloride concentrations under normal P supply and P deficiency. A significant effect (p < 0.05) of exogenous additive application was observed on the development of Chinese fir root length, surface area, and volume. These root development indices showed maximum values when the ethephon concentration was 0.01 g kg−1 under normal P supply and P deficiency, and they were significantly different from those under 0.04 g kg−1 ethephon treatment. Similarly, the indices showed maximum values when CoCl2 concentration was 0.01 g kg−1 under P deficiency and was significantly different (p < 0.01) from those under 0.2 g kg−1 CoCl2 treatment. Under normal P supply, an increase in ethephon concentration caused superoxide dismutase (SOD; E.C. 1.15.1.1) activity to decrease and peroxidase (POD; E.C. 1.11.1.X) activity to increase gradually. Conversely, CoCl2 addition (0.01 g kg−1) promoted SOD and POD activities under P deficiency. There were no significant differences (p > 0.05) in malondialdehyde content of seedlings among ethephon or CoCl2 treatments. In conclusion, ethylene plays a significant role in adaptative mechanisms underlying stress resistance in plants, prompting them to respond to P starvation and improving seedlings’ tolerance to P-deficient conditions.

Obesity and Oral Contraceptives Synergistically Increase Thrombotic Risk By Downregulating Protein S

Background: The increased thrombotic effects of estrogen-based oral contraceptives and obesity have been documented independently. However, obesity and oral contraceptives combined are associated with a far greater thrombotic risk, but we have a poor understanding of the mechanism of this greater effect. Increasingly, women are using oral contraceptives, and the national obesity rate has been skyrocketing. Thus, it is imperative to explain how obesity and oral contraceptives work together to significantly elevate thrombotic risk. We know that hypoxia-inducible factor 1-ɑ (HIF-1ɑ) and the estrogen receptor (Erɑ) bind to the promoter of the Protein S gene; binding occurs at sites within ~450 nucleotides of each other, and the two transcription factors downregulate Protein S expression independently. We hypothesize that the two factors, by binding the promoter simultaneously, synergistically downregulate Protein S to a degree much greater than the downregulation mediated by each factor separately. Aims: The goal of this project is determining whether estrogen and obesity-induced hypoxia work synergistically to downregulate Protein S transcription and increase thrombotic risk. Methods: We measured the effects of obesity and oral contraceptives on hepatocarcinoma (HEP G2) cells because the liver is the major producer of Protein S. Estrogen of varying concentrations (25-150 μM) was used to mimic the effects of oral contraceptives, and cobalt chloride of varying concentrations (25-150 μM) was used to stimulate hypoxia and HIF-1ɑ expression. Cells were exposed to estrogen only, cobalt chloride only, and estrogen and cobalt chloride together for 24 hours, after which the cells were harvested and subjected to q-PCR and immunoblot blot analyses to measure Protein S transcription and protein expression. Although cobalt chloride is a reliable inducer of hypoxia and HIF-1ɑ expression, we also performed hypoxia experiments by incubating cells in a chamber with varying O 2 concentrations (20%, 15%, 10%, 5%, 1%). Results and Conclusions: Immunoblot analysis of cells treated with either CoCl 2 and estrogen supplementation revealed a ~20% reduction in Protein S levels compared to control conditions and a more significant reduction in (~60%) Protein S expression in cells treated with estrogen and CoCl 2 together. These results supported our hypothesis that obesity and estrogen-based contraceptives increase thrombotic risk by downregulating anticoagulant Protein S transcription and subsequently decreasing Protein S level. Disclosures No relevant conflicts of interest to declare.

Genotoxicity of chromium (III) and cobalt (II) and interactions between them

Introduction. Chromium and cobalt are essential trace elements that are required only in a small amount, otherwise their excess can cause toxic effects. Aim. The aim of this study was to determine the effects of chromium (III) and cobalt (II) and their combinations on genotoxicity in human fibroblasts cells (BJ). Material and methods. In this work, comet and micronucleus assays were used. The BJ cells were exposed to chromium chloride and cobalt chloride at concentration ranges from 100 to 1400 µM. Mixtures of these elements were prepared so as to examine interactions between them. Results. The present study shows the genotoxic effects of chromium (III) and cobalt (II) and their mixtures on BJ cells. In the comet assay, no comets were observed at the lowest concentrations; in the higher, a significant increase in their percentage was observed. In the other assay (formation of micronuclei), a statistically significant increase in the number of cells with micronuclei was observed in the BJ cells spiked with cobalt chloride and chromium chloride. In the case of simultaneous incubation of chromium chloride at 200 µM and cobalt chloride at 1000 µM in the BJ line, antagonism was observed. However, the interaction of chromium chloride at the 1000 µM and cobalt chloride at 200 µM leads to synergism between the studied elements. Conclusions. Cobalt (II) and chromium (III) show genotoxic properties, they induce breaks in double and single-stranded DNA and they cause formation of AP-sites that do not have purine or pyrimidine bases.

Cobalt Chloride Alters Mitochondrial Function in a Dose Dependent Manner

Aim: This study was carried to evaluates of Cobalt chloride (CoCl2) on cardiac mitochondrial function. Methods: H9C2 cardiomyocytes were cultured in medium containing different concentrations of CoCl2. Cell viability, cardiolipin content, mitochondrial function, and mitochondrial oxidative stress were assessed by using Cell Counting Kit-8 and suitable fluorescence kits. Results: The obtained data showed that CoCl2 (200÷400 µM) induced cell death and decreased mitochondrial function of H9C2 cardiomyocytes in dose dependence. Especially, CoCl2 at dose of 300 µM significantly altered values of mitochondrial membrane potential, H2O2 and O2- to 63.79±2.15%, 145.81±5.83% and 143.10±3.07% (of 100% control), respectively. Conclusion: CoCl2 strongly induced cardiomyocyte death via altering mitochondrial function in a dose-dependent manner.