Conclusions
Recently, a new group of molecules, named SPMs that resolve inflammation were elucidated. Further, in efforts to investigate and demonstrate their mechanism of action, their receptors are slowly being discovered. As an additional milestone, SPMs were detected in several biological samples. However, the investigation of the pharmacological principle based on GPCR for SPMs under various physiological and pathological conditions is insufficient (Psychogios et al. 2011; Lukiw et al. 2005). Further research is needed on specific molecular targets of omega-3 fatty acids such as RvE2, RvD2, PDs, and MaRs. The interaction between the host immune system and infectious viral attacks represents new opportunities for the utilization of SPMs. The use of SPMs is likely to help regulate abnormal viral-mediated inflammation and prevent complications such as SARS-CoV-2 cytokine storm. Besides, SPMs play parts in restoring tissue homeostasis, including wound healing. Therefore, they are very likely to have therapeutic effects against the sequelae of SARS-CoV-2 infection. Both inflammation and resolution of inflammation are vital processes of the immune system. Therefore, a balance between the need for a sufficient immune response to clear the infection and the rapid decline of immune response to prevent host damage presents a novel opportunity for therapeutic exploitation of the SPMs.
Further research is needed to identify opportunities to optimize this balance in human viral infectivity. Among them, it will be exciting to study how the receptors of SPMs, which act as coreceptors during virus infection, play a role in virus infection and virus-induced inflammation. Finally, although not mentioned in this review, the author would like to emphasize that SPMs are effective in treating bacterial infections as well.
In nutshell, SPMs shows excellent potential as novel therapeutic options for severe inflammation and tissue damage caused by viral infections, including SARS-CoV-2 infection.
Fig. 1 Inflammation-resolution process.
Modified from Fullerton and Gilroy (Fullerton and Gilroy 2016), and Lee et al. (Lee 2018)
Fig. 2 SPMS and their receptors. Blue dotted lines mean activation of receptors, and red dotted lines inhibition of receptors
Fig. 3 Effects of SPMS on the virus life cycle. Please refer to the text for details. RTA: replication and transcription activator, KSHV: Kaposi’s sarcoma-associated herpesvirus
Fig. 4 Effects of SPMS on the viruses and viral infection-induced inflammation. Green lines mean direct antiviral effects. Blue dotted lines mean indirect effects on virus and purple dotted lines possible effects (not proved)