Flap transplantation is a critical surgical strategy for the reconstruction of tissue defects caused by trauma, tumor resection, and congenital malformations, and its survival rate directly determines surgical efficacy and patient prognosis. Following transplantation, flaps inevitably undergo ischemia-reperfusion (I/R) injury, during which oxidative stress, inflammatory responses, and metabolic disturbances are intricately intertwined, ultimately leading to cellular injury and tissue necrosis. Recent studies have demonstrated that multiple forms of programmed cell death—including apoptosis, pyroptosis, ferroptosis, necroptosis, and PANoptosis—play central roles in flap I/R injury. The extensive crosstalk and molecular interactions among these pathways form a highly complex cell death network. Specifically, apoptosis is mediated by the imbalance of Bcl-2 family proteins and the activation of cysteine-dependent aspartate-specific protease (caspase) cascades; pyroptosis is driven by the NLRP3-caspase-1-GSDMD axis, resulting in membrane pore formation and the release of pro-inflammatory cytokines; ferroptosis is characterized by iron-dependent lipid peroxidation and dysfunction of glutathione peroxidase 4 (GPX4); necroptosis is triggered by the receptor-interacting serine/threonine-protein kinase 1 (RIPK1)-RIPK3-MLKL signaling complex, leading to membrane rupture; and PANoptosis represents an integrated form of inflammatory cell death that coordinates multiple death pathways. Importantly, these forms of programmed cell death are not independent but are interconnected through extensive signaling crosstalk. Key regulatory molecules, including caspase-8, reactive oxygen species (ROS), nuclear factor-κB (NF-κB), and nuclear factor erythroid 2-related factor 2 (Nrf2), collectively modulate the dynamic balance among these pathways. Therefore, the multidimensional interplay and spatiotemporal dynamics of programmed cell death constitute a fundamental pathological basis of flap I/R injury. This review systematically summarizes the latest advances in the mechanisms and interactions of various programmed cell death pathways in flap I/R injury, aiming to elucidate the underlying regulatory network. These insights may provide novel theoretical foundations for optimizing flap protection strategies, improving flap survival, and promoting tissue repair.

Objective To study the effect of Exendin-4 on oxidative stress and neural apoptosis following spinal cord injury (SCI). Methods Adult male SD rats, with weight between 200-250 g, were randomly divided into three groups (12 in each group):Sham group, SCI group and Exendin-4 group (Ex-4 group). Rats in Sham group achieved spinal cord exposure. SCI group and Ex-4 group were induced according to Allen′s test (using a weight-drop device). Rats in Ex-4 group were ad?ministrated with Exendin-4 (10 μg/rat) through intraperitoneal injection immediately after establishment of SCI models. Rats in Sham group and SCI group were given the same volume of normal saline solution instead. Level of malondialdehyde (MDA) and the activity of catalase (CAT) were assessed in spinal cord tissues 24 hour after drug administrations. Neural apoptosis was detected by TUNEL staining and the expression levels of caspase-9 and AIF were determined using Western blot. Results Compared with Sham group, the levels of MDA, caspase-9 and AIF as well as neuronal apoptosis rate in?creased obviously, while activity of CAT decreased markedly in SCI group(P<0.01). Compared with SCI group, the levels of MDA, caspase-9 and AIF as well as the neuronal apoptosis rate decreased obviously, while activity of CAT increased re?markably in Exendin-4 group(P < 0.01). Conclusion Exendin-4 restrain neural apoptosis following spinal cord injury through relieving oxidative damage.