PLA1A, also known as phosphatidylserine-specific phospholipase A1-alpha, belongs to the pancreatic lipase family. It specifically hydrolyzes sn-1 fatty acid of phosphatidylserine (PS) or 1-acyl-lysophosphatidylserine (1-acyl-lysoPS), producing lysophosphatidylserine.

PLA1A is involved in multiple biological processes. It participates in the antiviral innate immune response by facilitating the recruitment of TANK-binding kinase 1 to mitochondria [2]. It also plays a role in immune cell regulation, such as influencing the maturation and functions of T cells, dendritic cells, macrophages, and mast cells [3].

In disease-related studies, gene-knockout mouse models have provided insights. In the mannan-induced psoriatic arthritis (MIP) mouse model, Pla1a−/− mice were less susceptible to MIP with reduced bone erosions and lower levels of cytokines like IL-17, KC, IP-10, MIP-1β, LIF, and VEGF in hind paw tissues. This indicates that PLA1A may contribute to MIP through increased activation of lymphocytes, possibly those producing IL-17 [5].

In melanoma, PLA1A expression was significantly increased during melanogenesis, positively correlated with disease severity and histopathological markers of metastatic melanoma. It can be used as a diagnostic marker for advanced and BRAF-mutated melanoma [1].

In lung adenocarcinoma, low PLA1A expression was correlated with poor prognosis. Overexpressed PLA1A suppressed the proliferation, migration, and invasion of lung adenocarcinoma cells both in vitro and in vivo [4].

In conclusion, PLA1A has diverse functions in biological processes and is implicated in various diseases. The study of Pla1a knockout mouse models has been crucial in revealing its role in psoriatic arthritis, while in other diseases like melanoma and lung adenocarcinoma, its expression patterns and functional impacts have been identified, contributing to our understanding of disease mechanisms and potential diagnostic or therapeutic applications.