Autophagy‑dependent cell death, ADCD

1 Mechanism Overview

Autophagy‑dependent cell death (ADCD) is a form of programmed cell death that is executed through the core molecular machinery of autophagy. ADCD is typically induced by various intracellular and extracellular stressors, including nutrient deprivation, metabolic stress, alterations in developmental signals, pharmacological stimulation, and aberrant oncogene activation. Its core regulatory mechanism is closely associated with the mTOR (mechanistic target of rapamycin) signaling pathway.

Under nutrient‑rich conditions, mTORC1 remains activated and suppresses autophagy initiation by inhibiting the ULK1 complex. However, under conditions of nutrient deprivation or energy stress, mTORC1 activity is inhibited, resulting in the activation of the ULK1/ATG13/FIP200 complex, which initiates autophagosome formation. Subsequently, the Beclin‑1–VPS34 complex promotes phagophore nucleation, while the ATG5–ATG12–ATG16L complex mediates membrane elongation. The conversion of LC3‑I to LC3‑II facilitates autophagosome maturation, ultimately establishing a complete autophagic process.

During ADCD, sustained enhancement of autophagic flux serves as a critical driver of cell death. Unlike moderate autophagy that maintains cellular homeostasis, autophagy in ADCD is excessively activated, resulting in continuous degradation of large amounts of intracellular proteins, organelles, and cytoplasmic components. When autophagic activity exceeds the cellular compensatory capacity, excessive depletion of cellular resources occurs, leading to metabolic imbalance, insufficient energy supply, and structural damage, ultimately resulting in irreversible cell death. Therefore, “excessive self‑consumption” is considered a fundamental concept underlying ADCD.

The mechanism of ADCD can be summarized as follows: external or endogenous stress signals induce mTORC1 inhibition and ULK1 activation, initiating an ATG‑dependent autophagic program; subsequently, sustained autophagic flux promotes extensive degradation of cellular components, while selective autophagy eliminates essential cellular structures or survival factors and induces lysosomal stress and metabolic collapse; ultimately, irreversible cellular damage and cell death occur.

ADCD represents a novel form of programmed cell death distinct from classical death modalities such as apoptosis, necrosis, and ferroptosis. It plays important roles in developmental regulation, cancer therapy, and disease mechanism studies.

Autophagy‑dependent cell death pathway schematic. Stress stimuli (nutrient deprivation, energy stress, drugs, etc.) activate AMPK and inhibit mTORC1, thereby initiating the ULK1‑dependent autophagic program. Subsequently, ATG proteins mediate autophagosome formation and enhance autophagic flux. When autophagy exceeds the capacity required for cellular homeostasis maintenance, excessive self‑consumption, selective organelle degradation, lysosomal damage, and metabolic collapse ultimately lead to autophagy‑dependent cell death (ADCD).

2 Target List

Mechanism Module	Target / Detection Marker	Full Name	Functional / Mechanistic Significance	Recommended Detection
Core Confirmation of ADCD	ATG5	Autophagy‑related protein 5	Essential protein for autophagosome formation; knockdown can block ADCD	WB / qPCR / KO or KD rescue experiments
	ATG7	Autophagy‑related protein 7	Core autophagy execution factor involved in LC3 lipidation	WB / qPCR
	BECN1 (Beclin‑1)	Beclin‑1 autophagy‑related protein	Initiates autophagy and promotes PI3K complex formation	WB / IF
	LC3B (LC3‑I/LC3‑II)	Microtubule‑associated protein 1 light chain 3 beta	Classical marker of autophagosome formation and autophagic conversion	WB / IF
	ATG12, ATG16L1	Autophagy‑related protein 12 / Autophagy‑related protein 16‑like 1	Components of the ATG5–ATG12–ATG16 complex	WB
Autophagy Initiation Regulation	p‑mTOR/mTOR	Phosphorylated mechanistic target of rapamycin / mechanistic target of rapamycin	mTORC1 inhibition promotes ADCD initiation	WB
	ULK1/p‑ULK1	Unc‑51 like autophagy activating kinase 1	Core activation factor of the autophagy initiation complex	WB
	ATG13, FIP200/RB1CC1	Autophagy‑related protein 13 / RB1‑inducible coiled‑coil protein 1	Components of the ULK1 initiation complex	WB
	p‑AMPK/AMPK	Phosphorylated AMP‑activated protein kinase / AMP‑activated protein kinase	Energy stress sensor promoting autophagy activation	WB
Autophagic Flux Assessment	p62/SQSTM1	Sequestosome 1	Autophagy substrate; decreased level indicates enhanced autophagic flux	WB / IF
	LAMP1/LAMP2	Lysosome‑associated membrane glycoprotein 1/2	Markers of autophagosome–lysosome fusion	WB / IF
	CTSB (Cathepsin B)	Cathepsin B	Lysosomal hydrolase involved in cell death execution	WB / IF
	CTSD (Cathepsin D)	Cathepsin D	Lysosomal protein degradation function	WB
Selective Autophagy / Mitophagy	PINK1	PTEN‑induced kinase 1	Recognition of damaged mitochondria	WB
	Parkin/PARK2	Parkin RBR E3 ubiquitin‑protein ligase	Promotes mitochondrial ubiquitination and clearance	WB
	BNIP3/NIX	BCL2 interacting protein 3 / BNIP3‑like protein	Receptor‑mediated mitophagy regulators	WB
	TOM20	Translocase of outer mitochondrial membrane 20	Indicator of mitochondrial content; decreases during excessive mitochondrial clearance	WB / IF
	COX IV	Cytochrome c oxidase subunit IV	Evaluation of mitochondrial quality	WB
Lysosome‑Dependent Death Mechanisms	LAMP1	Lysosome‑associated membrane glycoprotein 1	Marker of autolysosome formation	WB / IF
	TFEB	Transcription factor EB	Transcriptional regulator of lysosome biogenesis and autophagy	WB
	GBA1/GALC	Glucosylceramidase beta 1 / Galactosylceramidase	Lysosomal metabolism‑related factors involved in certain ADCD processes	WB
Metabolic Depletion Mechanisms	ATP level	Cellular ATP level	Reflects excessive autophagy‑induced energy depletion	Biochemical assay
	AMPK	AMP‑activated protein kinase	Regulator of energy stress response	WB
	HK2, GLUT1, LDHA	Hexokinase 2 / Glucose transporter 1 / Lactate dehydrogenase A	Indicators of glycolytic metabolic alterations	WB / qPCR
Exclusion of Apoptosis	Cleaved‑Caspase‑3	Cleaved caspase‑3	Determines whether cell death is mediated by classical apoptosis	WB
	Cleaved‑PARP	Cleaved poly(ADP‑ribose) polymerase	Execution marker of apoptosis	WB
	BAX/BCL‑2	BCL2‑associated X protein / B‑cell lymphoma‑2	Markers of mitochondrial apoptotic pathway	WB
Exclusion of Ferroptosis	GPX4	Glutathione peroxidase 4	Ferroptosis inhibitory protein	WB
	SLC7A11	Solute carrier family 7 member 11	Regulator of glutathione metabolism and cystine transport	WB
	ACSL4	Acyl‑CoA synthetase long‑chain family member 4	Ferroptosis‑promoting factor involved in PUFA metabolism	WB
Exclusion of Necroptosis	RIPK1/RIPK3/p‑MLKL	Receptor‑interacting protein kinase 1 / 3 / phosphorylated mixed lineage kinase domain‑like protein	Markers used to exclude necroptotic signaling	WB

3 Application Scheme

Function	Markers
Autophagy initiation	ULK1, ATG13, BECN1
Autophagosome formation	LC3‑I/II, ATG5, ATG7
Autophagic flux	p62/SQSTM1, LAMP1
Lysosomal function	LAMP1, Cathepsin B/D
mTOR regulation	p‑mTOR, p‑S6K, p‑ULK1
Mitochondrial clearance (Mitophagy)	PINK1, Parkin, TOM20
Exclusion of apoptosis	Caspase‑3, PARP
Cell death confirmation	ATG5/ATG7 knockdown rescue experiments

4 References

1. Denton D, Kumar S. Autophagy‑dependent cell death. Cell Death Differ. 2019;26(4):605‑616. doi:10.1038/s41418‑018‑0252‑y.
2. Jung S, Jeong H, Yu SW. Autophagy as a decisive process for cell death. Exp Mol Med. 2020;52:921‑930. doi:10.1038/s12276‑020‑0455‑4.
3. Huang X, Yan H, Xu Z, et al. The inducible role of autophagy in cell death: emerging evidence and future perspectives. Cell Commun Signal. 2025;23:151.