Table 1.

Comparison of distinct aspects of RCD pathways.

RCD pathway	Morphological characteristics		Occurrence mechanism	Common inspection methods and indicators	Major associated disease
Autophagy-dependent cell death (22, 23, 28)	Cytomembrane	The autophagosome is formed, which wraps around and encloses the organelles to be degraded.	The autophagy pathway primarily occurs in two ways (1): non-selective autophagy, involving the extensive degradation of encapsulated organelles and intracellular proteins; and (2) selective autophagy, targeting the degradation of specific entities such as diseased cells or viruses.	The localization of the transcription factor TFEB, determination of ATG expression (such as Atg5, Atg7, and Atg8/LC3), and observation of autophagosomes (including their membrane structure and proteins) are necessary.	Tumors, neurodegenerative diseases, cardiovascular diseases, etc.
	Cytoplasm	The number of autophagosomes gradually increased, and the fusion of lysosomes led to the formation of autolysosomes.
	Nucleus	No special change.
	Organelle	The shape and number of mitochondria are significantly altered, and the number of autophagosomes increases, while the structure of the endoplasmic reticulum also appears to be expanded or fragmented.
Anoikis (24, 29)	Cytomembrane	The cytomembrane displays folds and bulbous expansions, leading to the formation of flower-like ring protrusions.	The loss of cell-matrix force or the weakening of cell-cell adhesion leads to the activation of signaling proteins and apoptosis pathways.	Apoptosis-related markers, such as Annexin V, and nuclear and chromosomal histochemical staining were detected.	It is closely related to the metastasis of tumor
	Cytoplasm	The organelles gradually compact, resulting in cell shrinkage and clumping.
	Nucleus	Chromatin aggregation, nuclear membrane rupture, and nucleus fragmentation occur.
	Organelle	The cytoskeleton is reorganized, mitochondrial function is impaired, and ultimately, the system collapses completely.
Ferroptosis (25, 26)	Cytomembrane	Lipid per, leading to the rupture of cell membranes.	The main cause is the excessive presence of free iron ions in the cell, which leads to oxidative stress and increased lipid peroxidation of the cell membrane. This triggers the signaling pathway for cell death.	The degree of lipid peroxidation, the content of endogenous iron ions, and the expression levels of related genes and proteins were assessed.	It is mainly associated with neurodegenerative diseases and tumors.
	Cytoplasm	Mineralized clusters appear.
	Nucleus	No special change.
	Organelle	Mitochondrial structural changes, increased oxidative stress, and endoplasmic reticulum stress.
Cuproptosis (27)	Cytomembrane	Multiple villous bulges are formed on the cytomembrane	Intracellular overload of copper ions leads to oxidative stress, disrupts the intracellular REDOX balance, and ultimately results in cell death.	The concentration of copper ions, oxidative stress and cell death were measured.	Neurodegenerative diseases and metabolic related diseases.
	Cytoplasm	The organelles become smaller and tightly packed.
	Nucleus	Nuclear morphology is irregular and nuclear fragments appear.
	Organelle	Mitochondrial structural changes, increased oxidative stress, and endoplasmic reticulum stress.
Pyroptosis (30)	Cytomembrane	The cell membrane forms numerous holes, leading to an ion imbalance that causes the cell to swell and dissolve, ultimately leading to the rupture of the cell membrane.	The main way to activate Caspase-1 or Caspase-4/5/11 by inflammasome complexes (such as NLRP3, AIM2), these Caspases then cleave Gasdermin D (GSDMD), causing its N-terminal fragment to insert into the cell membrane and form pores, leading to cell membrane rupture and release of cellular contents, including pro-inflammatory cytokines such as IL-1β and IL-18, thereby triggering a severe inflammatory response and cell death.	Lactate dehydrogenase (LDH) release assay, enzyme-linked immunosorbent assay (ELISA) etc.	Inflammatory diseases, cardiovascular diseases, and tumors.
	Cytoplasm	The cells rapidly swell, and cellular contents leak out, releasing inflammatory factors such as IL-1β and IL-18 into the cytoplasm.
	Nucleus	The nuclear DNA fragments, but not in a structured way like apoptosis; chromatin is partially condensed.
	Organelle	Mitochondrial depolarization, loss of integrity of lysosomal membrane.
ICD (31)	Cytomembrane	The surface exposes high mobility group box protein B1 (HMGB1), calreticulin (CRT), and heat shock proteins (HSPs).	This mainly involves the translocation and release of specific signaling molecules, such as endoplasmic reticulum stress-induced calreticulin (CRT) on the surface and high-mobility group box 1 (HMGB1) released extracellularly, as well as ATP released, which are recognized and taken up by dendritic cells and other antigen-presenting cells.	Flow cytometry, immunofluorescence staining, ATP release detection, etc.	Tumors, autoimmune diseases, and infections.
	Cytoplasm	Releases multiple immune stimulating substances.
	Nucleus	DNA breaks and chromatin condensation resemble apoptosis, but also involve the release of immune-related molecules.
	Organelle	The mitochondrial membrane potential is lost, and there is a significant endoplasmic reticulum stress response.

The divergence in the mechanisms underlying different RCD pathways can be attributed to the regulation of both internal and external signals. These signals encompass DNA damage, perturbation of cell cycle control, cytokine signaling, nutrient deprivation, as well as extracellular matrix cues. Upon sensing these signals, specific pathways are triggered, ultimately leading to cell death. In this table, we compare various RCD pathways in terms of cell morphological characteristics, pathogenesis, commonly employed examination methods and indicators, as well as key associated diseases. By doing so, we aim to provide a comprehensive summary of the commonalities and distinctions among different pathways, which could facilitate future practical applications.