Baicalein Activates Parkin-Dependent Mitophagy through NDP52 and OPTN

Abstract

The elimination of intracellular components by autophagy maintains metabolic homeostasis and is a quality-control pathway that enables organelle regeneration. Mitophagy is a type of selective autophagy that regulates mitochondrial turnover, and the dysregulation of mitophagy has been implicated in the pathogenesis of liver diseases. However, the detailed molecular mechanism underlying mitophagy regulation in liver cells remains unclear, and the small molecules that may potentially modulate hepatic mitophagy are still unavailable. Here, we report that baicalein, a flavonoid extracted from Scutellaria baicalensis, induces the entire autophagy that proceeds through the autolysosome maturation stage in human hepatoma cells. In addition, baicalein-induced autophagy is demonstrated to target mitochondria for degradation. Further studies show that baicalein triggers the translocation of Parkin and TBK1 to mitochondria to induce mitophagy. Moreover, the phosphorylation of TBK1 at Ser172 and ubiquitin at Ser65 is shown to trigger mitophagy in baicalein-treated cells. Furthermore, two specific autophagy cargo receptors, NDP52 and OPTN, that function in baicalein-activated mitophagy are identified. Taken together, these findings not only delineate the molecular process of Parkin-dependent mitophagy in liver cells, but also reveal baicalein as a novel inducer of hepatic mitophagy.

HSPA8-mediated stability of the CLPP protein regulates mitochondrial autophagy in cisplatin-resistant ovarian cancer cells

“…NIX, a protein on the outer membrane of mitochondria, recruits LC3 II/I to form autophagosomes that wrap damaged mitochondria. This autophagy process can help to maintain intracellular stability by allowing damaged mitochondria to be cleared [ 43 , 44 ]. Thus, mitochondrial function is thought to be closely related to DDP resistance.…”

Construction and evaluation of Alzheimer’s disease diagnostic prediction model based on genes involved in mitophagy

“…Activated Parkin recruits OPTN proteins into the mitochondria. With the increasing number of OPTN proteins, mitochondrial autophagy is activated ( Ke et al, 2022 ). Some researchers have found that in AD, Aβ exposure can induce the activation of PINK1/Parkin/OPTN pathway, upregulate the expression level of OPTN, and initiate mitochondrial autophagy to reduce the accumulation of Aβ.…”

HSPA8-mediated stability of the CLPP protein regulates mitochondrial autophagy in cisplatin-resistant ovarian cancer cells

“…NIX, a protein on the outer membrane of mitochondria, recruits LC3 II/I to form autophagosomes that wrap damaged mitochondria. This autophagy process can help to maintain intracellular stability by allowing damaged mitochondria to be cleared [43,44]. Thus, mitochondria function is thought to be closely related to DDP resistance.…”