Related Experiment Video
Updated: Sep 28, 2025
Mechanism of Kemeng Fang's Inhibition of Podocyte Apoptosis in Rats with Membranous Nephropathy through the PI3K/AKT Signaling Pathway
Published on: August 23, 2024
Ming-Mu-Di-Huang-Pill Activates SQSTM1 via AMPK-Mediated Autophagic KEAP1 Degradation and Protects RPE Cells from
Xi Chen1,2,3, Yujie Zhu1,2,3, Xiaoqing Shi1,3
1First College of Clinical Medicine, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210029, China.
Abstract:
Oxidative stress and diminished autophagy in the retinal pigment epithelium (RPE) play crucial roles in the pathogenesis of age-related macular degeneration (AMD). Enhancing autophagy has recently been identified as an important strategy to protect RPE cells from oxidative damage. Ming-Mu-Di-Huang-Pill (MMDH pill) is a traditional herbal medicine used to treat AMD, and its molecular mechanism is not well understood. The aim of the present study was to investigate whether the MMDH pill relieved acute oxidative damage by activating autophagy in an in vitro and in vivo model of sodium iodate (NaIO3). The results showed that NaIO3 induced cell death and inhibited proliferation. The MMDH pill increased cell viability, restored the activities of antioxidant enzymes, and reduced reactive oxygen species (ROS) fluorescence intensity. The MMDH pill mediated Kelch-like ECH-associated protein 1 (Keap1) degradation and decreased oxidative damage, which was blocked in autophagy inhibitor (chloroquine) or sequestosome-1 (SQSTM1) siRNA-treated RPE cells. Furthermore, we indicated that the MMDH pill could promote adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and autophagy adaptor-SQSTM1 expression, which could stimulate autophagic degradation of Keap1. In addition, the MMDH pill increased nuclear factor (erythroid-derived 2)-like 2 (Nrf2) nuclear translocation in a SQSTM1-dependent manner and induced the expression of the downstream antioxidant factors heme oxygenase-1 (HO-1) and nicotinamide adenine dinucleotide phosphate quinone dehydrogenase 1 (NQO1). In conclusion, MMDH pill plays a protective role in relieving NaIO3-induced oxidative stress by activating the AMPK/SQSTM1/Keap1 pathway. The MMDH pill may be useful to treat AMD by maintaining redox homeostasis and autophagy.
Insights
Ming-Mu-Di-Huang-Pill enhances autophagy to protect retinal cells from oxidative stress, a key factor in age-related macular degeneration. This traditional medicine may offer a new therapeutic strategy for AMD by restoring cellular balance.
Area of Science:
- Ophthalmology
- Cell Biology
- Pharmacology
Background:
- Oxidative stress and impaired autophagy in retinal pigment epithelium (RPE) cells contribute to age-related macular degeneration (AMD) pathogenesis.
- Enhancing autophagy is a promising strategy for protecting RPE cells against oxidative damage.
- The molecular mechanisms of traditional herbal medicines like Ming-Mu-Di-Huang-Pill (MMDH pill) for AMD treatment require elucidation.
Purpose of the Study:
- To investigate the protective effects of MMDH pill against sodium iodate (NaIO3)-induced oxidative stress in RPE cells.
- To determine if MMDH pill activates autophagy and its underlying molecular pathways.
- To evaluate the therapeutic potential of MMDH pill for AMD.
Main Methods:
- In vitro and in vivo models of NaIO3-induced oxidative stress in RPE cells.
- Assessment of cell viability, antioxidant enzyme activity, and reactive oxygen species (ROS) levels.
- Analysis of key proteins involved in autophagy and oxidative stress response, including Keap1, AMPK, SQSTM1, Nrf2, HO-1, and NQO1.
- Inhibition studies using chloroquine (autophagy inhibitor) and SQSTM1 siRNA.
Main Results:
- MMDH pill treatment increased RPE cell viability, restored antioxidant enzyme activity, and reduced ROS levels.
- MMDH pill promoted the degradation of Keap1 and decreased oxidative damage, effects that were abolished by autophagy inhibition.
- MMDH pill activated the AMPK/SQSTM1 pathway, leading to enhanced autophagic degradation of Keap1.
- MMDH pill increased Nrf2 nuclear translocation in a SQSTM1-dependent manner, upregulating downstream antioxidant genes HO-1 and NQO1.
Conclusions:
- MMDH pill exerts protective effects against NaIO3-induced oxidative stress by activating the AMPK/SQSTM1/Keap1 pathway and enhancing autophagy.
- MMDH pill may be a valuable therapeutic agent for AMD by maintaining redox homeostasis and promoting autophagy in RPE cells.
Related Concept Videos
02:23Abnormal Proliferation
01:22PI3K/mTOR/AKT Signaling Pathway