Oxidative Damage and Cellular Senescence: Lessons from Bacteria and Yeast

2006 ◽  
pp. 473-484 ◽  
Author(s):  
Thomas Nyström
2007 ◽  
Vol 41 (5) ◽  
pp. 571-579 ◽  
Author(s):  
Hung-yao Ho ◽  
Mei-ling Cheng ◽  
Pei-Fen Cheng ◽  
Daniel Tsun-Yee Chiu

2016 ◽  
Vol 41 (11) ◽  
pp. 2904-2913 ◽  
Author(s):  
Eduardo B. Parisotto ◽  
Verónica Vidal ◽  
Susana García-Cerro ◽  
Sara Lantigua ◽  
Danilo Wilhelm Filho ◽  
...  

Author(s):  
O. T. Minick ◽  
E. Orfei ◽  
F. Volini ◽  
G. Kent

Hemolytic anemias were produced in rats by administering phenylhydrazine or anti-erythrocytic (rooster) serum, the latter having agglutinin and hemolysin titers exceeding 1:1000.Following administration of phenylhydrazine, the erythrocytes undergo oxidative damage and are removed from the circulation by the cells of the reticulo-endothelial system, predominantly by the spleen. With increasing dosage or if animals are splenectomized, the Kupffer cells become an important site of sequestration and are greatly hypertrophied. Whole red cells are the most common type engulfed; they are broken down in digestive vacuoles, as shown by the presence of acid phosphatase activity (Fig. 1). Heinz body material and membranes persist longer than native hemoglobin. With larger doses of phenylhydrazine, erythrocytes undergo intravascular fragmentation, and the particles phagocytized are now mainly red cell fragments of varying sizes (Fig. 2).


2020 ◽  
Vol 477 (14) ◽  
pp. 2715-2720
Author(s):  
Susana Castro-Obregón

The nuclear envelope is composed by an outer nuclear membrane and an inner nuclear membrane, which is underlain by the nuclear lamina that provides the nucleus with mechanical strength for maintaining structure and regulates chromatin organization for modulating gene expression and silencing. A layer of heterochromatin is beneath the nuclear lamina, attached by inner nuclear membrane integral proteins such as Lamin B receptor (LBR). LBR is a chimeric protein, having also a sterol reductase activity with which it contributes to cholesterol synthesis. Lukasova et al. showed that when DNA is damaged by ɣ-radiation in cancer cells, LBR is lost causing chromatin structure changes and promoting cellular senescence. Cellular senescence is characterized by terminal cell cycle arrest and the expression and secretion of various growth factors, cytokines, metalloproteinases, etc., collectively known as senescence-associated secretory phenotype (SASP) that cause chronic inflammation and tumor progression when they persist in the tissue. Therefore, it is fundamental to understand the molecular basis for senescence establishment, maintenance and the regulation of SASP. The work of Lukasova et al. contributed to our understanding of cellular senescence establishment and provided the basis that lead to the further discovery that chromatin changes caused by LBR reduction induce an up-regulated expression of SASP factors. LBR dysfunction has relevance in several diseases and possibly in physiological aging. The potential bifunctional role of LBR on cellular senescence establishment, namely its role in chromatin structure together with its enzymatic activity contributing to cholesterol synthesis, provide a new target to develop potential anti-aging therapies.


2010 ◽  
Vol 34 (8) ◽  
pp. S27-S27
Author(s):  
Xueling Dai ◽  
Ping Chang ◽  
Ke Xu ◽  
Changjun Lin ◽  
Hanchang Huang ◽  
...  

2002 ◽  
Vol 7 (5) ◽  
pp. 295-313 ◽  
Author(s):  
Patricia A. McChesney ◽  
Lynne W. Elmore ◽  
Shawn E. Holt
Keyword(s):  

Author(s):  
Paulina Iwan ◽  
Jan Stepniak ◽  
Malgorzata Karbownik-Lewinska

Abstract. Iodine is essential for thyroid hormone synthesis. Under normal iodine supply, calculated physiological iodine concentration in the thyroid is approx. 9 mM. Either potassium iodide (KI) or potassium iodate (KIO3) are used in iodine prophylaxis. KI is confirmed as absolutely safe. KIO3 possesses chemical properties suggesting its potential toxicity. Melatonin (N-acetyl-5-methoxytryptamine) is an effective antioxidant and free radical scavenger. Study aims: to evaluate potential protective effects of melatonin against oxidative damage to membrane lipids (lipid peroxidation, LPO) induced by KI or KIO3 in porcine thyroid. Homogenates of twenty four (24) thyroids were incubated in presence of either KI or KIO3 without/with melatonin (5 mM). As melatonin was not effective against KI-induced LPO, in the next step only KIO3 was used. Homogenates were incubated in presence of KIO3 (200; 100; 50; 25; 20; 15; 10; 7.5; 5.0; 2.5; 1.25 mM) without/with melatonin or 17ß-estradiol. Five experiments were performed with different concentrations of melatonin (5.0; 2.5; 1.25; 1.0; 0.625 mM) and one with 17ß-estradiol (1.0 mM). Malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA) concentration (LPO index) was measured spectrophotometrically. KIO3 increased LPO with the strongest damaging effect (MDA + 4-HDA level: ≈1.28 nmol/mg protein, p < 0.05) revealed at concentrations of around 15 mM, thus corresponding to physiological iodine concentrations in the thyroid. Melatonin reduced LPO (MDA + 4-HDA levels: from ≈0.97 to ≈0,76 and from ≈0,64 to ≈0,49 nmol/mg protein, p < 0.05) induced by KIO3 at concentrations of 10 mM or 7.5 mM. Conclusion: Melatonin can reduce very strong oxidative damage to membrane lipids caused by KIO3 used in doses resulting in physiological iodine concentrations in the thyroid.


Sign in / Sign up

Export Citation Format

Share Document