scholarly journals Ascorbate glutathione-dependent H2O2 scavenging is an important process in axillary bud outgrowth in rosebush

2020 ◽  
Vol 126 (6) ◽  
pp. 1049-1062
Author(s):  
Alexis Porcher ◽  
Vincent Guérin ◽  
Françoise Montrichard ◽  
Anita Lebrec ◽  
Jérémy Lothier ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Marker Gene ◽  
Buthionine Sulfoximine ◽  
Direct Consequence ◽  
Axillary Bud ◽  
Transcriptional Level ◽  
Quiescent State ◽  
Synthesis Inhibitor ◽  
Axillary Bud Outgrowth

Abstract Background and Aims Branching is an important mechanism of plant shape establishment and the direct consequence of axillary bud outgrowth. Recently, hydrogen peroxide (H2O2) metabolism, known to be involved in plant growth and development, has been proposed to contribute to axillary bud outgrowth. However, the involvement of H2O2 in this process remains unclear. Methods We analysed the content of H2O2 during bud outgrowth and characterized its catabolism, both at the transcriptional level and in terms of its enzymatic activities, using RT–qPCR and spectrophotometric methods, respectively. In addition, we used in vitro culture to characterize the effects of H2O2 application and the reduced glutathione (GSH) synthesis inhibitor l-buthionine sulfoximine (BSO) on bud outgrowth in relation to known molecular markers involved in this process. Key Results Quiescent buds displayed a high content of H2O2 that declined when bud outgrowth was initiated, as the consequence of an increase in the scavenging activity that is associated with glutathione pathways (ascorbate–glutathione cycle and glutathione biosynthesis); catalase did not appear to be implicated. Modification of bud redox state after the application of H2O2 or BSO prevented axillary bud outgrowth by repressing organogenesis and newly formed axis elongation. Hydrogen peroxide also repressed bud outgrowth-associated marker gene expression. Conclusions These results show that high levels of H2O2 in buds that are in a quiescent state prevents bud outgrowth. Induction of ascorbate–glutathione pathway scavenging activities results in a strong decrease in H2O2 content in buds, which finally allows bud outgrowth.

scholarly journals Aldosterone induces active K+ secretion by enhancing mucosal expression of Kcnn4c and Kcnma1 channels in rat distal colon

2012 ◽  
Vol 302 (9) ◽  
pp. C1353-C1360 ◽  
Author(s):  
Satish K. Singh ◽  
Bryan O'Hara ◽  
Jamilur R. Talukder ◽  
Vazhaikkurichi M. Rajendran
Keyword(s):  
Channel Blocker ◽  
Short Circuit ◽  
Distal Colon ◽  
Normal Colonic Mucosa ◽  
Transcriptional Level ◽  
Mrna Levels ◽  
Atpase Inhibitor ◽  
Synthesis Inhibitor ◽  
Rat Distal Colon

Although both Kcnn4c and Kcnma1 channels are present on colonic mucosal membranes, only Kcnma1 has been suggested to mediate K+ secretion in the colon. Therefore, studies were initiated to investigate the relative roles of Kcnn4c and Kcnma1 in mediating aldosterone (Na-free diet)-induced K+ secretion. Mucosal to serosal (m-s), serosal to mucosal (s-m), and net 86Rb+ (K+ surrogate) fluxes as well as short circuit currents ( Isc; measure of net ion movement) were measured under voltage clamp condition in rat distal colon. Active K+ absorption, but not K+ secretion, is present in normal, while aldosterone induces active K+ secretion (1.04 ± 0.26 vs. −1.21 ± 0.15 μeq·h−1·cm−2; P < 0.001) in rat distal colon. Mucosal VO4 (a P-type ATPase inhibitor) inhibited the net K+ absorption in normal, while it significantly enhanced net K+ secretion in aldosterone animals. The aldosterone-induced K+ secretion was inhibited by the mucosal addition of 1) either Ba2+ (a nonspecific K+ channel blocker) or charybdotoxin (CTX; a common Kcnn4 and Kcnma1 channel blocker) by 89%; 2) tetraethyl ammonium (TEA) or iberiotoxin (IbTX; a Kcnma1 channel blocker) by 64%; and 3) TRAM-34 (a Kcnn4 channel blocker) by 29%. TRAM-34, but not TEA, in the presence of IbTX further significantly inhibited the aldosterone-induced K+ secretion. Thus the aldosterone-induced Ba2+/CTX-sensitive K+ secretion consists of IbTX/TEA-sensitive (Kcnma1) and IbTX/TEA-insensitive fractions. TRAM-34 inhibition of the IbTX-insensitive fraction is consistent with the aldosterone-induced K+ secretion being mediated partially via Kcnn4c. Western and quantitative PCR analyses indicated that aldosterone enhanced both Kcnn4c and Kcnma1α protein expression and mRNA abundance. In vitro exposure of isolated normal colonic mucosa to aldosterone also enhanced Kcnn4c and Kcnma1α mRNA levels, and this was prevented by exposure to actinomycin D (an RNA synthesis inhibitor). These observations indicate that aldosterone induces active K+ secretion by enhancing mucosal Kcnn4c and Kcnma1 expression at the transcriptional level.

scholarly journals Protective effects of glutathione, glycine, or alanine in an in vitro model of renal anoxia.

1992 ◽  
Vol 2 (8) ◽  
pp. 1338-1344 ◽  
Author(s):  
M S Paller ◽  
M Patten
Keyword(s):  
Cell Injury ◽  
Primary Cultures ◽  
Buthionine Sulfoximine ◽  
Experimental Models ◽  
Protective Effects ◽  
Synthesis Inhibitor ◽  
Lactate Dehydrogenase Release ◽  
Reoxygenation Injury ◽  
Vitro Model

Both glutathione and glycine provide some protection against ischemic renal injury in a variety of experimental models. However, results have been inconsistent and there may also be model heterogeneity. The effects of glutathione, glycine, and alanine in a cell culture model of renal anoxia/reoxygenation injury were tested. When primary cultures of rat proximal tubule epithelial cells were subjected to 60 min of anoxia and 30 min of reoxygenation, glutathione (2 mM) essentially eliminated lethal cell injury as determined by lactate dehydrogenase release. Glycine or alanine, on the other hand, provided only partial protection. Glutamate did not protect, although cysteine did. The glutathione synthesis inhibitor buthionine sulfoximine blocked the protective effect of exogenous glutathione, and the glutathione transport inhibitor probenecid partially blocked glutathione protection. A combination of glycine, glutamate, plus cysteine also protected against anoxia/reoxygenation injury. The studies suggest that both glutathione degradation with intracellular resynthesis and transport of intact glutathione into the cell are involved in the protection afforded by exogenous glutathione. These results are different from those obtained in other experimental models of renal ischemia, such as freshly isolated proximal tubules, because the protective effects of glutathione were not derived solely from glycine generation. These studies also suggest the need for caution in extrapolating results from one model of renal anoxic injury to another.

scholarly journals Aberrantly high activation of a FoxM1–STMN1 axis contributes to progression and tumorigenesis in FoxM1-driven cancers

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Jun Liu ◽  
Jipeng Li ◽  
Ke Wang ◽  
Haiming Liu ◽  
Jianyong Sun ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Poor Prognosis ◽  
Soft Agar ◽  
Transcriptional Level ◽  
Regulation Mechanism ◽  
Strong Positive Correlation ◽  
Cell Viability Assay ◽  
High Level

AbstractFork-head box protein M1 (FoxM1) is a transcriptional factor which plays critical roles in cancer development and progression. However, the general regulatory mechanism of FoxM1 is still limited. STMN1 is a microtubule-binding protein which can inhibit the assembly of microtubule dimer or promote depolymerization of microtubules. It was reported as a major responsive factor of paclitaxel resistance for clinical chemotherapy of tumor patients. But the function of abnormally high level of STMN1 and its regulation mechanism in cancer cells remain unclear. In this study, we used public database and tissue microarrays to analyze the expression pattern of FoxM1 and STMN1 and found a strong positive correlation between FoxM1 and STMN1 in multiple types of cancer. Lentivirus-mediated FoxM1/STMN1-knockdown cell lines were established to study the function of FoxM1/STMN1 by performing cell viability assay, plate clone formation assay, soft agar assay in vitro and xenograft mouse model in vivo. Our results showed that FoxM1 promotes cell proliferation by upregulating STMN1. Further ChIP assay showed that FoxM1 upregulates STMN1 in a transcriptional level. Prognostic analysis showed that a high level of FoxM1 and STMN1 is related to poor prognosis in solid tumors. Moreover, a high co-expression of FoxM1 and STMN1 has a more significant correlation with poor prognosis. Our findings suggest that a general FoxM1-STMN1 axis contributes to cell proliferation and tumorigenesis in hepatocellular carcinoma, gastric cancer and colorectal cancer. The combination of FoxM1 and STMN1 can be a more precise biomarker for prognostic prediction.

An in vitro senescence model of gingival epithelial cell induced by hydrogen peroxide treatment

Odontology ◽  
2021 ◽  
Author(s):  
Sarita Giri ◽  
Ayuko Takada ◽  
Durga Paudel ◽  
Koki Yoshida ◽  
Masae Furukawa ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Epithelial Cell ◽  
Gingival Epithelial Cell ◽  
Hydrogen Peroxide Treatment

scholarly journals miR-29a sensitizes the response of glioma cells to temozolomide by modulating the P53/MDM2 feedback loop

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Qiudan Chen ◽  
Weifeng Wang ◽  
Shuying Chen ◽  
Xiaotong Chen ◽  
Yong Lin
Keyword(s):  
Molecular Mechanism ◽  
Feedback Loop ◽  
Glioma Cells ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Transcriptional Level ◽  
Aberrant Expression ◽  
Altered Expression ◽  
P53 Signaling

AbstractRecently, pivotal functions of miRNAs in regulating common tumorigenic processes and manipulating signaling pathways in brain tumors have been recognized; notably, miR‐29a is closely associated with p53 signaling, contributing to the development of glioma. However, the molecular mechanism of the interaction between miR-29a and p53 signaling is still to be revealed. Herein, a total of 30 glioma tissues and 10 non-cancerous tissues were used to investigate the expression of miR‐29a. CCK-8 assay and Transwell assay were applied to identify the effects of miR-29a altered expression on the malignant biological behaviors of glioma cells in vitro, including proliferation, apoptosis, migration and invasion. A dual-luciferase reporter assay was used to further validate the regulatory effect of p53 or miR-29a on miR-29a or MDM2, respectively, at the transcriptional level. The results showed that miR-29a expression negatively correlated with tumor grade of human gliomas; at the same time it inhibited cell proliferation, migration, and invasion and promoted apoptosis of glioma cells in vitro. Mechanistically, miR-29a expression was induced by p53, leading to aberrant expression of MDM2 targeted by miR-29a, and finally imbalanced the activity of the p53-miR-29a-MDM2 feedback loop. Moreover, miR-29a regulating p53/MDM2 signaling sensitized the response of glioma cells to temozolomide treatment. Altogether, the study demonstrated a potential molecular mechanism in the tumorigenesis of glioma, while offering a possible target for treating human glioma in the future.

scholarly journals 4-Methylumbelliferone administration enhances radiosensitivity of human fibrosarcoma by intercellular communication

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryo Saga ◽  
Yusuke Matsuya ◽  
Rei Takahashi ◽  
Kazuki Hasegawa ◽  
Hiroyuki Date ◽  
...  
Keyword(s):  
Intercellular Communication ◽  
Dose Range ◽  
Synthesis Inhibitor ◽  
X Ray ◽  
Tumour Control ◽  
Synergetic Effects ◽  
Fibrosarcoma Cells ◽  
Oxidative Stress Level ◽  
Human Fibrosarcoma Cells

AbstractHyaluronan synthesis inhibitor 4-methylumbelliferone (4-MU) is a candidate of radiosensitizers which enables both anti-tumour and anti-metastasis effects in X-ray therapy. The curative effects under such 4-MU administration have been investigated in vitro; however, the radiosensitizing mechanisms remain unclear. Here, we investigated the radiosensitizing effects under 4-MU treatment from cell experiments and model estimations. We generated experimental surviving fractions of human fibrosarcoma cells (HT1080) after 4-MU treatment combined with X-ray irradiation. Meanwhilst, we also modelled the pharmacological effects of 4-MU treatment and theoretically analyzed the synergetic effects between 4-MU treatment and X-ray irradiation. The results show that the enhancement of cell killing by 4-MU treatment is the greatest in the intermediate dose range of around 4 Gy, which can be reproduced by considering intercellular communication (so called non-targeted effects) through the model analysis. As supposed to be the involvement of intercellular communication in radiosensitization, the oxidative stress level associated with reactive oxygen species (ROS), which leads to DNA damage induction, is significantly higher by the combination of 4-MU treatment and irradiation than only by X-ray irradiation, and the radiosensitization by 4-MU can be suppressed by the ROS inhibitors. These findings suggest that the synergetic effects between 4-MU treatment and irradiation are predominantly attributed to intercellular communication and provide more efficient tumour control than conventional X-ray therapy.

scholarly journals Chromatic intervention and biocompatibility assay for biosurfactant derived from Balanites aegyptiaca (L.) Del

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vishal Panchariya ◽  
Vishal Bhati ◽  
Harishkumar Madhyastha ◽  
Radha Madhyastha ◽  
Jagdish Prasad ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Skin Fibroblast ◽  
Mouse Skin ◽  
Fibroblast Cells ◽  
Toxicity Assay ◽  
Balanites Aegyptiaca ◽  
Hemolysis Assay ◽  
Full Factorial ◽  
Human Rbcs

AbstractExtraction of biosurfactants from plants is advantageous than from microbes. The properties and robustness of biosurfactant derived from the mesocarp of Balanites aegyptiaca have been reported. However, the dark brown property of biosurfactant and lack of knowledge of its biocompatibility limits its scope. In the present work, the decolorization protocol for this biosurfactant was optimized using hydrogen peroxide. The hemolytic potential and biocompatibility based on cell toxicity and proliferation were also investigated. This study is the first report on the decolorization and toxicity assay of this biosurfactant. For decolorization of biosurfactant, 34 full factorial design was used, and the data were subjected to ANOVA. Results indicate that 1.5% of hydrogen peroxide can decolorize the biosurfactant most efficiently at 40 °C in 70 min at pH 7. Mitochondrial reductase (MTT) and reactive oxygen species (ROS) assays on M5S mouse skin fibroblast cells revealed that decolorized biosurfactant up to 50 µg/mL for 6 h had no significant toxic effect. Hemolysis assay showed ~ 2.5% hemolysis of human RBCs, indicating the nontoxic effect of this biosurfactant. The present work established a decolorization protocol making the biosurfactant chromatically acceptable. Biocompatibility assays confirm its safer use as observed by experiments on M5S skin fibroblast cells under in vitro conditions.

scholarly journals Dynamic changes of podocytes caused by fibroblast growth factor 2 in culture

2021 ◽  
Author(s):  
Eishin Yaoita ◽  
Masaaki Nameta ◽  
Yutaka Yoshida ◽  
Hidehiko Fujinaka
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth Factor 2 ◽  
Quiescent State ◽  
Fibroblast Growth ◽  
Gene Expressions ◽  
Dynamic Changes ◽  
Ki 67

AbstractFibroblast growth factor 2 (FGF2) augments podocyte injury, which induces glomerulosclerosis, although the mechanisms remain obscure. In this study, we investigated the effects of FGF2 on cultured podocytes with interdigitating cell processes in rats. After 48 h incubation with FGF2 dynamic changes in the shape of primary processes and cell bodies of podocytes resulted in the loss of interdigitation, which was clearly shown by time-lapse photography. FGF2 reduced the gene expressions of constituents of the slit diaphragm, inflections of intercellular junctions positive for nephrin, and the width of the intercellular space. Immunostaining for the proliferation marker Ki-67 was rarely seen and weakly stained in the control without FGF2, whereas intensely stained cells were frequently found in the presence of FGF2. Binucleation and cell division were also observed, although no significant increase in cell number was shown. An in vitro scratch assay revealed that FGF2 enhanced migration of podocytes. These findings show that FGF2 makes podocytes to transition from the quiescent state into the cell cycle and change their morphology due to enhanced motility, and that the culture system in this study is useful for analyzing the pathological changes of podocytes in vivo.

Sign in / Sign up

Export Citation Format

Share Document