42002-05-1Relevant articles and documents
4-Hydroxy-7-oxo-5-heptenoic acid lactone can induce mitochondrial dysfunction in retinal pigmented epithelial cells
Ayyash, Naji,Cheng, Yu-Shiuan,Gardella, Anthony,Li, Haoting,Linetsky, Mikhail,Salomon, Robert G.
, p. 719 - 733 (2020)
Oxidation of docosahexaenoate (DHA)-containing phospholipids in the cell plasma membrane leads to release of the α,β-unsaturated aldehyde 4-hydroxy-7-oxo-5-heptenoic acid (HOHA) lactone which is capable of inducing retinal pigmented epithelial (RPE) cell dysfunction. Previously, HOHA lactone was shown to induce apoptosis and angiogenesis, and to activate the alternative complement pathway. RPE cells metabolize HOHA lactone through enzymatic conjugation with glutathione (GSH). Competing with this process is the adduction of HOHA lactone to protein lysyl residues generating 2-(ω-carboxyethyl)pyrrole (CEP) derivatives that have pathological relevance to age-related macular degeneration (AMD). We now find that HOHA lactone induces mitochondrial dysfunction. It decreases ATP levels, mitochondrial membrane potentials, enzymatic activities of mitochondrial complexes, depletes GSH and induces oxidative stress in RPE cells. The present study confirmed that pyridoxamine and other primary amines, which have been shown to scavenge γ-ketoaldehydes formed by carbohydrate or lipid peroxidation, are ineffective for scavenging the α,β-unsaturated aldehydes. Histidyl hydrazide (HH), that has both hydrazide and imidazole nucleophile functionalities, is an effective scavenger of HOHA lactone and it protects ARPE-19 cells against HOHA lactone-induced cytotoxicity. The HH α-amino group is not essential for this electrophile trapping activity. The Nα-acyl L-histidyl hydrazide derivatives with 2- to 7-carbon acyl groups with increasing lipophilicities are capable of maintaining the effectiveness of HH in protecting ARPE-19 cells against HOHA lactone toxicity, which potentially has therapeutic utility for treatment of age related eye diseases.
Amino Acid Functionalized Organotin Trichlorides and Their Tin Sulfide Clusters
Engel, Annikka,Dehnen, Stefanie
, (2019/08/02)
We present a new synthesis of functionalized tin sulfide clusters via organotin trichlorides with boc-protected amino acids (RAAcSnCl3). In this work we used non-polar (alanine, valine, leucine, phenylalanine and methionine), polar/neutral (serine and tyrosine) and basic (histidine) amino acids. We obtained single crystals from a Boc-protected valine derivative of the originally used organotin trichloride R1SnCl3 [R1 = CMe2CH2C(O)Me] and determined its structure by means of X-ray diffraction. A subsequent reaction with sulfide sources led to a variety of respective cluster structures. By using either (Me3Si)2S or Na2S, the reaction product turns out to be the defect-heterocubane cluster [(RAAcSn)3S4Cl] or the “doppeldecker”-type cluster [(RAAcSn)4S6], respectively, according to 119Sn NMR spectroscopy.