oxidative degradation

Liposomes are spherical or multilayered spherical vesicles formed by the self-assembly of diacyl chain phospholipids (lipid bilayers) in aqueous solutions, which can be made from natural or synthetic phospholipids and exhibit good biocompatibility and low toxicity. They can serve as delivery carriers for various bioactive substances (such as drugs, proteins, nucleic acids, etc.) and are widely used in biomedical and chemical research. The main advantages of liposomes include 1) Protective effect: Their bilayer structure can protect encapsulated molecules from enzymatic degradation, oxidation, and other influences, extending stability and activity; 2) Active targeting: Surface modifications enable active targeting, enhancing the concentration of drugs or molecules in specific tissues or cells; 3) Customizability: The composition and structure of liposomes can be adjusted according to needs, such as altering phospholipid types or adding targeting ligands. These properties make liposomes highly valuable in developing novel drug delivery systems, serving as nucleic acid carriers for gene transfection, studying cellular uptake mechanisms and drug release kinetics, as well as developing functional food additives to improve the bioavailability of nutritional components.

MCE contains 140 liposome compounds, which is a good tool for lipidomic-related studies.

Oxygen homeostasis regulation is the most fundamental cellular process for adjusting physiological oxygen variations, and its irregularity leads to various human diseases, including cancer. Hypoxia is closely associated with cancer development, and hypoxia/oxygen-sensing signaling plays critical roles in the modulation of cancer progression.

Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that functions as a master regulator of oxygen homeostasis. A variety of HF-1 target genes have been identified thus far which encode proteins that play key roles in critical developmental and physiological processes including angiogenesis/vascular remodeling, erythropoiesis, glucose transport, glycolysis, iron transport, and cell proliferation/survival.

HIF-1 is a heterodimeric transcription factor consisting of a constitutively expressed β-subunit and an oxygen-regulated α-subunit. The unique feature of HIF-1 is the regulation of HIF-1α expression and activity based upon the cellular O₂ concentration. Under normoxic conditions, hydroxylation of HIF-1α on these different proline residues is essential for HIF proteolytic degradation by promoting interaction with the von Hippel-Lindau tumor-suppressor protein (pVHL) through hydrogen bonding to the hydroxyproline-binding pocket in the pVHL β-domain. As oxygen levels decrease, hydroxylation of HIF decreases; HIF-1α then no longer binds pVHL, and becomes stabilized, allowing more of the protein to translocate to the cell’s nucleus, where it acts as a transcription factor, upregulating (often within minutes) the production of proteins that stimulate blood perfusion in tissues and thus tissue oxygenation.

MCE offers a unique collection of 3,261 oxygen sensing related compounds targeting HIF/HIF Prolyl-Hydroxylase, MAPK/ERK, PI3K/AKT signaling pathways, etc. MCE Oxygen Sensing Compound Library is a useful tool to study hypoxia, oxidative stress and discover new anti-cancer drugs.