Objective: This study aims to summarize the role of PIWIs/piRNAs in cell apoptosis through multiple signaling pathways. The PIWI-interacting RNAs (piRNAs) are among the small non-coding RNAs (sncRNAs) and are mainly expressed in germline cells. PIWI protein is the key to the biogenesis of piRNA. With the deepening of research in recent years, the PIWIs/piRNAs are expressed in a tissue-specific way in somatic cells outside the germline. In addition, researchers have found that the PIWIs/piRNAs play a regulatory role in cell apoptosis, proliferation, and necrosis by regulating key signaling pathways, such as PI3K/Akt signaling pathway, STAT signaling pathway, TGF-β signaling pathway, and Fas signaling pathway at the transcriptional or post-transcriptional level. However, the PIWIs/piRNAs' role in cell apoptosis and its underlying mechanisms are still not fully understood. This study reviews the regulatory functions of PIWIs/piRNAs in apoptosis from the perspective of the signal pathway.
Materials and methods: This study is a narrative review. PubMed and MEDLINE were used as the primary sources to search the following keywords: PIWI/piRNAs, signal pathway, pro-apoptotic, anti-apoptotic, and signaling pathway.
Results: PIWIs/piRNAs modulated pro-apoptotic or anti-apoptotic effects in a variety of cells: PIWIs/piRNAs through PI3K/Akt signaling pathway, STAT signaling pathway, TGF-β signaling pathway, and Fas signaling pathway for pro-apoptotic or anti-apoptotic effects in cells.
Conclusions: Apoptosis is a basic biological phenomenon of cell death, and it also has a great significance and complex molecular biological mechanisms. PIWI/piRNAs are closely related to various types of diseases and play a pro-apoptotic or anti-apoptotic role through the following pathways: PI3K/Akt signaling, STAT signaling, TGF-β signaling, and Fas signaling pathways.