Showing papers on "Lanosterol synthase published in 2019"
TL;DR: Diffuse intrinsic pontine glioma (DIPG) remains an incurable childhood brain tumor for which novel therapeutic approaches are desperately needed, andabolomic and biochemical analyses identify lanosterol synthase as the direct molecular target of MI-2, revealing this metabolic enzyme as a vulnerability in gliomas and further implicating cholesterol homeostasis as an attractive pathway to target in this malignancy.
Abstract: Diffuse intrinsic pontine glioma (DIPG) remains an incurable childhood brain tumor for which novel therapeutic approaches are desperately needed. Previous studies have shown that the menin inhibitor MI-2 exhibits promising activity in preclinical DIPG and adult glioma models, although the mechanism underlying this activity is unknown. Here, using an integrated approach, we show that MI-2 exerts its antitumor activity in glioma largely independent of its ability to target menin. Instead, we demonstrate that MI-2 activity in glioma is mediated by disruption of cholesterol homeostasis, with suppression of cholesterol synthesis and generation of the endogenous liver X receptor ligand, 24,25-epoxycholesterol, resulting in cholesterol depletion and cell death. Notably, this mechanism is responsible for MI-2 activity in both DIPG and adult glioma cells. Metabolomic and biochemical analyses identify lanosterol synthase as the direct molecular target of MI-2, revealing this metabolic enzyme as a vulnerability in glioma and further implicating cholesterol homeostasis as an attractive pathway to target in this malignancy.
44 citations
University of Nantes1, University of Lorraine2, Necker-Enfants Malades Hospital3, Hamad Medical Corporation4, University of Burgundy5, Boston Children's Hospital6, École pratique des hautes études7, Cliniques Universitaires Saint-Luc8, GeneDx9, University of Franche-Comté10, University Hospital of Basel11, University of Paris12
TL;DR: The data suggest LSS as a major gene causing a rare recessive neuroectodermal syndrome, formerly named alopecia with mental retardation (APMR) syndrome, is suggested.
35 citations
TL;DR: UV-B exposure induced oxidative injury and resulted in crystallin denaturation and apoptosis in lens epithelial cells, and LSS might play a protective role during the early stages of this process and could be an important target in the cataract prevention.
Abstract: UV-B radiation may be an important risk factor in cataract etiology. After exposure to UV-B radiation, cells show imbalances in the repair of DNA damage, which induce changes in the levels of certain proteins, including alpha-crystallin, which is the most abundant protein in the lens and crucial for the maintenance of lens transparency. Lanosterol synthase (LSS), an essential rate-limiting enzyme in cholesterol biosynthesis, might play significant roles in oxidative stress and in the maintenance of lens transparency. However, the roles of LSS in UV-B-induced apoptosis are not well understood. Therefore, we irradiated female Sprague-Dawley rats with ultraviolet radiation to establish an animal model for exploring the variations in LSS expression during the early stages of UV-B exposure. In addition, we cultured human lens epithelial (HLE) cells that overexpress LSS and exposed them to UV-B radiation to explore the function of increased LSS expression in UV-B-induced apoptosis. The data demonstrated that UV-B exposure induced oxidative stress and apoptosis in rat lens epithelial cells and that irradiance exposure increased the level of lenticular damage. Additionally, UV-B exposure decreased the alpha-crystallin content and increased the expressions of Bax and cleaved caspase-3 compared with the control levels. After exposure to UV-B, the apoptosis-related index of HLE cells overexpressing LSS was lower than that of the control cells. Furthermore, ROS overproduction might activate the sirtuin 1 (Sirt1) pathway, which induced protein expressions of sterol regulatory element-binding transcription factor 2 (SREBF2), 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), and LSS. However, the specific mechanism of the Sirt1 pathway needed to be further studied. In summary, UV-B exposure induced oxidative injury and resulted in crystallin denaturation and apoptosis in lens epithelial cells, and LSS might play a protective role during the early stages of this process and could be an important target in the cataract prevention.
24 citations
TL;DR: It is found that initiation of salt-induced hypertension involves a type of kidney dysfunction (natriuretic handicap) which causes salt-sensitive subjects to excrete less of a sodium load than normal subjects and to undergo abnormal increases in cardiac output.
Abstract: Objective:For decades, it has been widely accepted that initiation of salt-induced hypertension involves a type of kidney dysfunction (natriuretic handicap) which causes salt-sensitive subjects to excrete less of a sodium load than normal subjects and to undergo abnormal increases in cardiac output,
1 citations