Qixian granule inhibits ferroptosis in vascular endothelial cells by modulating TRPML1 in the lysosome to prevent postmenopausal atherosclerosis.

ETHNOPHARMACOLOGICAL RELEVANCE: QiXian Granule (QXG) is an integrated traditional Chinese medicine formula used to treat postmenopausal atherosclerotic (AS) cardiovascular diseases. The previous studies have found that QXG inhibited isoproterenol (ISO)-induced myocardial remodeling. And its active ingredient, Icraiin, can inhibit ferroptosis by promoting oxidized low-density lipoprotein (xo-LDL)-induced vascular endothelial cell injury and autophagy in atherosclerotic mice. Another active ingredient, Salvianolic Acid B, can suppress ferroptosis and apoptosis during myocardial ischemia/reperfusion injury by reducing ubiquitin-proteasome degradation of Glutathione Peroxidase 4 (GPX4) and down-regulating the reactive oxygen species (ROS)- c-Jun N-terminal kinases (JNK)/mitogen-activated protein kinase (MAPK) pathway. AIM OF THE STUDY: The objective of this research was to assess the possible impact of QXG on atherosclerosis in postmenopausal individuals and investigate its underlying mechanisms. MATERIALS AND METHODS: Female ApoE-/- mice underwent ovariectomy and were subjected to a high-fat diet (HFD) to establish a postmenopausal atherosclerosis model. The therapeutic effects of QXG were observed in vivo and in vitro through intraperitoneal injection of erastin, G-protein Coupled Estrogen Receptor (GPER) inhibitor (G15), and silent Mucolipin Transient Receptor Potential Channel 1 (TRPML1) adenovirus injection via tail vein. UPLC-MS and molecular docking techniques identified and evaluated major QXG components, contributing to the investigation of QXG's anti-postmenopausal atherosclerotic effects. RESULTS: QXG increased serum Estradiol levels, decreased follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels, which indicated QXG had estrogen-like effects in Ovx/ApoE-/- mice. Furthermore, QXG demonstrated the potential to impede the progression of AS in Ovx/ApoE-/- mice, as evidenced by reductions in serum triglycerides (TG), total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C) levels. Additionally, QXG inhibited ferroptosis in Ovx/ApoE-/- mice. Notably, UPLC-MS analysis identified a total of 106 active components in QXG. The results of molecular docking analysis demonstrated that Epmedin B, Astragaloside II, and Orientin exhibit strong binding affinity towards TRPML1. QXG alleviates the progression of atherosclerosis by activating TRPML1 through the GPER pathway or directly activating TRPML1, thereby inhibiting GPX4 and ferritin heavy chain (FTH1)-mediated iron pendant disease. In vitro, QXG-treated serum suppressed proliferation, migration, and ox-LDL-induced MMP and ROS elevation in HAECs. CONCLUSION: QXG inhibited GPX4 and FTH1-mediated ferroptosis in vascular endothelial cells through up-regulating GPER/TRPML1 signaling, providing a potential therapeutic option for postmenopausal females seeking a safe and effective medication to prevent atherosclerosis. The study highlights QXG's estrogenic properties and its promising role in combating postmenopausal atherosclerosis.

Artemisia Leaf Extract protects against neuron toxicity by TRPML1 activation and promoting autophagy/mitophagy clearance in both in vitro and in vivo models of MPP+/MPTP-induced Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is a neurodegenerative disorder involving the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Cellular clearance mechanisms, including the autophagy-lysosome pathway, are commonly affected in the pathogenesis of PD. The lysosomal Ca2+ channel mucolipin TRP channel 1 (TRPML1) is one of the most important proteins involved in the regulation of autophagy. Artemisia argyi Lev. et Vant., is a traditional Chinese herb, that has diverse therapeutic properties and is used to treat patients with skin diseases and oral ulcers. However, the neuroprotective effects of A. argyi are not explored yet. HYPOTHESIS: This study aims is to investigate the neuroprotective effects of A. argyi in promoting the TRPML1-mediated autophagy/mitophagy-enhancing effect METHODS: In this study, we used 1-methyl-4-phenyl-pyridinium (MPP+)-induced PD model established in an SH-SY5Y human neuroblastoma cell line as well as in a 1-methyl-4-phenyl-1,2,3,6-tetrahydro-pyridine (MPTP)-induced PD model in C57BL/6 J mice. MTT assay was conducted to measure the cell viability and further MitoSoX and DCFDA assay were used to measure the ROS. Western blot analysis was used to access levels of TRPML1, p-DRP1 (ser616), p-AKT, PI3K, and ß-catenin, Additionally, IF and IHC analysis to investigate the expression of TRPML1, LC3B, ß-catenin, TH+, α-synuclein. Mitotracker stain was used to check mitophagy levels and a lysosomal intracellular activity kit was used to measure the lysosomal dysfunction. Behavioral studies were conducted by rotarod and grip strength experiments to check motor functions. RESULTS: In our in vitro study, A. argyi rescued the MPP+-induced loss of cell viability and reduced the accumulation of mitochondrial and total reactive oxygen species (ROS). Subsequently, it increased the expression of TRPML1 protein, thereby inducing autophagy, which facilitated the clearance of toxic accumulation of α-synuclein. Furthermore, A. argyi played a neuroprotective role by activating the PI3K/AKT/ß-catenin cell survival pathway. MPP+-mediated mitochondrial damage was overcome by upregulation of mitophagy and downregulation of the mitochondrial fission regulator p-DRP1 (ser616) in SH-SY5Y cells. In the in vivo study, A. argyi ameliorated impaired motor function and rescued TH+ neurons in the SNpc region. Similar to the results of the in vitro study, TRPML1, LC3B, and ß-catenin expression was enhanced in the SNpc region in the A. argyi-treated mice brain. CONCLUSION: Thus, our results first demonstrate that A. argyi can exert neuroprotective effects by stimulating TRPML1 and rescuing neuronal cells by boosting autophagy/mitophagy and upregulating a survival pathway, suggesting that A. argyi can further be exploited to slow the progression of PD.

Unconventional role of lysosomes in phagocytosis.

Lysosomes are generally thought to be required only for the late stages of phagosome maturation, providing the proton pumps (V-ATPases) and hydrolases needed to acidify and degrade the ingested prey. A recent paper by Davis et al. (EMBO J. [2020], doi:10.15252/embj.2019104058) reports the involvement of lysosomes at a much earlier stage, namely in scission of phagosomes from the plasma membrane. Here we analyze these findings, highlighting a number of unexpected observations and unresolved questions.

The complex interplay of iron metabolism, reactive oxygen species, and reactive nitrogen species: insights into the potential of various iron therapies to induce oxidative and nitrosative stress.

Production of minute concentrations of superoxide (O2(*-)) and nitrogen monoxide (nitric oxide, NO*) plays important roles in several aspects of cellular signaling and metabolic regulation. However, in an inflammatory environment, the concentrations of these radicals can drastically increase and the antioxidant defenses may become overwhelmed. Thus, biological damage may occur owing to redox imbalance-a condition called oxidative and/or nitrosative stress. A complex interplay exists between iron metabolism, O2(*-), hydrogen peroxide (H2O2), and NO*. Iron is involved in both the formation and the scavenging of these species. Iron deficiency (anemia) (ID(A)) is associated with oxidative stress, but its role in the induction of nitrosative stress is largely unclear. Moreover, oral as well as intravenous (iv) iron preparations used for the treatment of ID(A) may also induce oxidative and/or nitrosative stress. Oral administration of ferrous salts may lead to high transferrin saturation levels and, thus, formation of non-transferrin-bound iron, a potentially toxic form of iron with a propensity to induce oxidative stress. One of the factors that determine the likelihood of oxidative and nitrosative stress induced upon administration of an iv iron complex is the amount of labile (or weakly-bound) iron present in the complex. Stable dextran-based iron complexes used for iv therapy, although they contain only negligible amounts of labile iron, can induce oxidative and/or nitrosative stress through so far unknown mechanisms. In this review, after summarizing the main features of iron metabolism and its complex interplay with O2(*-), H2O2, NO*, and other more reactive compounds derived from these species, the potential of various iron therapies to induce oxidative and nitrosative stress is discussed and possible underlying mechanisms are proposed. Understanding the mechanisms, by which various iron formulations may induce oxidative and nitrosative stress, will help us develop better tolerated and more efficient therapies for various dysfunctions of iron metabolism.