Autophagy, a highly conserved cellular degradation mechanism, maintains intracellular homeostasis by removing damaged organelles and abnormal proteins. Its dysregulation is closely associated with various diseases. Autophagy-related protein 12 (ATG12), a core member of the ubiquitin-like protein family, covalently binds to ATG5 through a ubiquitin-like conjugation system to form the ATG12-ATG5-ATG16L1 complex. This complex directly regulates the formation and maturation of autophagosomes, making ATG12 a key molecule in the initiation of autophagy. Recent studies have revealed that ATG12 functions extend far beyond the classical autophagy context. It promotes apoptosis by binding to anti-apoptotic proteins of the Bcl-2 family (e.g., Bcl-2 and Mcl-1) and enhances host antiviral immunity by regulating the NF-κB and interferon signaling pathways. Moreover, ATG12 deficiency can lead to mitochondrial biogenesis impairment, energy metabolism disorders, and substrate-dependent metabolic shifts, underscoring its pivotal role in cellular metabolic homeostasis. At the disease level, dysregulation of ATG12 expression is closely linked to tumorigenesis and cancer progression. By modulating the dynamic balance between autophagy and apoptosis, ATG12 influences cancer cell proliferation, metastasis, and chemoresistance. Notably, ATG12 is abnormally overexpressed in multiple cancers, including breast, liver, and gastric cancer, highlighting its potential as a therapeutic target. Furthermore, in neurodegenerative diseases such as Parkinson’s disease, ATG12 mitigates protein toxicity by enhancing mitochondrial autophagy. In cardiovascular diseases, it alleviates ischemia-reperfusion injury by regulating cardiomyocyte autophagy and apoptosis, demonstrating its broad regulatory role across various pathological conditions. Genetic studies further underscore the clinical significance of ATG12. Polymorphisms in the ATG12 gene (e.g., rs26537 and rs26538) have been significantly associated with the risk of head and neck squamous cell carcinoma, hepatocellular carcinoma, and atrophic gastritis. Notably, the risk allele of rs26537 enhances ATG12 promoter activity, leading to its overexpression and promoting tumorigenesis. These findings provide a molecular basis for individualized risk assessment and targeted interventions based on ATG12 genotype. Despite significant progress, many aspects of ATG12 biology remain unclear. The precise regulatory mechanisms of its post-translational modifications (e.g., ubiquitination and acetylation) are yet to be fully elucidated. Additionally, the molecular pathways underlying its non-canonical functions, such as metabolic regulation and immune modulation, require further investigation. Moreover, the functional heterogeneity of ATG12 in different tumor microenvironments and its role in drug resistance warrant in-depth exploration. Future research should integrate advanced technologies such as cryo-electron microscopy, single-cell sequencing, and organoid models to decipher the intricate regulatory network of ATG12. Additionally, developing small-molecule inhibitors or gene-editing tools targeting its protein interaction interfaces (e.g., the ATG12-ATG3 binding domain) may help overcome current therapeutic challenges. Through interdisciplinary collaboration and clinical translation, ATG12 holds promise as a next-generation molecular target for precision intervention in autophagy-related diseases. This review summarizes the structure and function of ATG12, its role in autophagy initiation, its physiological functions, and its involvement in disease pathogenesis. Furthermore, it discusses future research directions and potential challenges, emphasizing ATG12’s potential as a biomarker and therapeutic target in autophagy-related diseases.

Polycystin-2 (also known as PC2, TRPP2, PKD2) is a major contributor to the underlying etiology of autosomal dominant polycystic kidney disease (ADPKD), which is the most prevalent monogenic kidney disease in the world. As a transient receptor potential (TRP) channel protein, PC2 exhibits cation-permeable, Ca²⁺-dependent channel properties, and plays a crucial role in maintaining normal Ca²⁺ signaling in systemic physiology, particularly in ADPKD chronic kidney disease. Structurally, PC2 protein consists of six transmembrane structural domains (S1-S6), a polycystin-specific “tetragonal opening for polycystins” (TOP) domain located between the S1 and S2 transmembrane structures, and cytoplasmic N- and C-termini. Although the cytoplasmic N-terminus and C-terminus of PC2 may not be significant in the gating of PC2 channels, there is still much protein structural information that needs to be thoroughly investigated, including the regulation of channel function and the assembly of homotetrameric ion channels. This is further supported by the presence of human disease-associated mutation sites on the PC2 structure. Moreover, PC2 synthesized in the endoplasmic reticulum is enriched in specific subcellular localization via membrane transport and can assemble itself into homotetrameric ion channels, as well as form heterotrimeric receptor-ion channel complexes with other proteins. These complexes are involved in a wide range of physiological functions, including the regulation of mechanosensation, cell polarity, cell proliferation, and apoptosis. In particular, PC2 assembles with chaperone proteins to form polycystic protein complexes that affect Ca²⁺ transport in cell membranes, cilia, endoplasmic reticulum, and mitochondria, and are involved in activating cell fate-related signaling pathways, particularly cell differentiation, proliferation, survival, and apoptosis, and more recently, autophagy. This leads to a shift of cystic cells from a normal uptake, quiescent state to a pathologically secreted, proliferative state. In conclusion, the complex structural and functional roles of PC2 highlight its critical importance in the pathogenesis of ADPKD, making it a promising target for therapeutic intervention.

Pancreatic cancer (PC) is a highly fatal disease which originated from pancreatic epithelial and acinar cells, and the survival rate of pancreatic cancer patients is only about 12%. Approximately 95% of pancreatic cancer presents as ductal adenocarcinoma (PDAC). Pancreatic cancer is characterized by high aggressiveness, rapid progression and progression, and high resistance to treatment. Common somatic mutated genes in the early stage of pancreatic cancer include KRAS, CDKN2A, TP53, and SMAD4. Most pancreatic cancer patients are affected by environmental risk factors such as age, sex and diet. Malignant pancreatic cancer is associated with non-invasive, preneoplastic lesions that are thoughted to be precursors, such as pancreatic intraepithelial neoplasia (PanIN), intraductal papillary mucinous neoplasm (IPMN) and mucinous cystadenoma (MCN). In recent years, people have gradually improved the therapy and diagnosis of pancreatic cancer, and the contribution of imaging technology, which enhancing the usage of minimally invasive pancreatectomy that typically includes pancreaticoduodenectomy and distal pancreatectomy. However, combined administration of the chemotherapeutic gemcitabine and erlotinib is still considered a potential first-line treatment for advanced pancreatic cancer, but the development of chemoresistance often leads to poor therapeutic outcomes. Based on the current research progress for pancreatic cancer, its treatment currently remains one of the most important challenges in the medical field. Although some new treatment options have been provided, there were minor clinical success achieved and therefore new safe and effective therapies of pancreatic cancer are still an urgent need for patients. Among these new therapies for pancreatic cancer, short peptide-based treatment protocols have attracted great attention. Peptide is a compound formed by linking α-amino acids together in peptide chains. It is also an intermediate product of proteolysis. The short peptide-based therapy has many advantages such as precise targeting, easy preparation and low toxicity. Short peptides usually act as tumor suppressors by targeting and recognizing tumor-specific expressed proteins. Currently, there is an increased interest in peptides in pharmaceutical and development research, and approximate 140 peptide therapeutics are currently being evaluated in clinical trials. These peptides provide excellent prospects for targeted drug delivery because of their high selectivity, specificity and simplicity of modification. Peptides have high bioactivity and excellent biodegradability. Clinically, short peptides are increasingly used as combination drugs with chemotherapy for tumor treatment. Peptides can induce cancer cell death by numerous mechanisms and peptides have emerged as a promising drug for the treatment of pancreatic cancer. Here we mainly review the roles of peptides on Wnt/β-catenin, NF-κB, autophagy, and the use of peptides as tracer in pancreatic cancer. We also analyzed the benefits and disadvantages existing in the development process of short peptides, which provide the feasibility of targeted short peptides to become new therapeutic approaches for cancer therapy.

Objective : To investigate the effects of angiopoietin 4 (ANGPT4) on the odontogenic differentiation of human dental pulp stem cells. Methods : This study has been reviewed and approved by the Ethics Committee, and informed consent has been obtained from patients. Human premolars were fixed, decalcified, dehydrated, embedded, and sectioned. Immunofluorescence staining was used to observe the expression and localization of ANGPT4. Human dental pulp stem cells (hDPSCs) were isolated and cultured in vitro. The growth state and morphology of hDPSCs were observed under an inverted phase contrast microscope. The expression of cell surface-related molecular markers was detected by flow cytometry. Alkaline phosphatase and alizarin red S staining were used to detect the odontogenic differentiation potential of hDPSCs. Oil-red O staining was used to detect the adipogenic differentiation potential of hDPSCs. RNA was extracted from hDPSCs at different time points after odontogenic induction, and RT-qPCR was used to analyze the mRNA expression of ANGPT4 and odontogenic-related genes during the odontogenic differentiation of hDPSCs in vitro. siRNA gene silencing technology was used to silence the expression of ANGPT4 in hDPSCs, and the silencing efficiency was detected by RT-qPCR and Western Blot. After silencing ANGPT4 in hDPSCs for 24 h, odontogenic induction was performed. Alkaline phosphatase and alizarin red S staining were performed on the 7th and 14th of induction to detect the odontogenic differentiation ability of hDPSCs after silencing ANGPT4 Results : Immunofluorescence staining of human premolars showed that ANGPT4 was expressed in odontoblasts and sub-odontoblastic cell-rich zone. hDPSCs were in good condition after 14 days of isolation and culture. Under the microscope, multiple cell colonies were observed, and the cell morphology was uniform and long spindle-shaped. The results of flow cytometry showed that hDPSCs expressed mesenchymal stem cell markers CD105 (90.42%) and CD90 (97.15%), but did not express hematopoietic cell markers CD45 (0.01%) and CD34 (0.08%). After odontogenic and adipogenic induction of hDPSCs, alkaline phosphatase staining, alizarin red S staining and oil red O staining were positive. The results of RT-qPCR after the odontogenic induction of hDPSCs showed that ANGPT4 was highly expressed on the 5th, 7th, 11th and 14th days of differentiation of hDPSCs (P<0.05), with the highest expression level on the 5th day. After hDPSCs were transfected with si-ANGPT4, the expression of ANGPT4 mRNA and protein was significantly down-regulated (P<0.05). The results of alkaline phosphatase staining showed that ALP staining intensity and area in the si-ANGPT4 group were significantly lower than those in the negative control. Alizarin red S staining showed that the formation of calcium nodules in the si-ANGPT4 group was significantly lower than that in the negative control. Conclusion ANGPT4 was expressed in odontoblasts and sub-odontoblastic cell-rich zone of human premolars. ANGPT4 may be a factor to promote the odontogenic differentiation of hDPSCs.