Language
Country/Area
No result found
The Invisible Enemy of Cardiovascular Disease: How Does AIM Affect Your Heart Health?
In the study of cardiovascular health, as scientists conduct in-depth discussions, more and more cytokines and proteins have gradually emerged. One of the potential factors that has attracted attention is macrophage apoptosis inhibitory factor (AIM). The presence of this protein not only affects immune responses and inflammatory processes, but may also become an invisible enemy of cardiovascular disease. This article will explore the impact of AIM on heart health and whether it protects or harms our cardiovascular system.
Overview
AIM is a 40 kDa protein encoded by the CD5L gene. It is mainly produced by tissue-resident macrophages and is regulated by transcription-activating nuclear receptors (such as LXR/RXR) or the transcription factor MAFB. AIM belongs to the scavenger receptor cysteine-rich (SRCR) superfamily and possesses three SRCR domains. In serum, AIM binds to IgM pentamers, preventing their renal excretion and maintaining high circulating levels. Although AIM is bound to IgM in an inactive state, it dissociates under disease conditions to promote repair.
These studies indicate that the specific binding mode of AIM is unclear, but the binding mode of AIM-Fc is similar to that of antibody-antigen interaction and has lower affinity.
AIM functions
AIM plays multiple roles in the body, regulating internal processes such as lipid metabolism and apoptosis, inhibiting cholesterol synthesis, and affecting the pathogenicity of Th17 cells. Although diverse effects of AIM on the regulation of inflammation have been discovered, the specific mechanisms of all these effects remain unclear, and being able to discern their beneficial or detrimental roles is even more difficult.
AIM in autoimmune diseases
In autoimmune diseases, the increased expression of AIM has become a potential biomarker, but its role and mechanism have not yet been clarified. In a series of autoimmune diseases such as ALS, rheumatoid arthritis, etc., the level of AIM is abnormally increased and is closely related to the activity of the disease.
In both psoriasis and Crohn's disease, AIM plays an integral role in promoting the inflammatory process.
AIM in cardiovascular and pulmonary diseases
The role of AIM in cardiovascular and pulmonary diseases is mostly focused on inflammation, by inhibiting the apoptosis of macrophages and promoting inflammatory responses. AIM is highly expressed in foam macrophages in atherosclerotic plaques and significantly affects macrophage survival and inflammatory response.
AIM-null mice show favorable prognosis in recovery after myocardial infarction, including improved survival and reduced cardiac rupture.
AIM’s dual role
The role of AIM in the liver is equally complex. In terms of lipid metabolism, AIM helps promote related inflammatory responses, while in the liver microenvironment it antagonizes the pro-fibrotic effects of TGFβ1, showing its adaptive response. But in hepatocellular carcinoma (HCC), elevated AIM is often associated with tumor aggressiveness and proliferation.
The impact of AIM on renal function
The presence of AIM also affects kidney health, especially in acute kidney injury (AKI). Research shows that AIM increases during AKI and can bind to kidney injury molecule (KIM-1) to promote the removal of cell debris and tissue repair.
Mice treated with recombinant AIM showed improved renal pathology in the treatment of AKI, which may provide a basis for novel AKI treatments.
In summary, the role of AIM in various diseases is multifaceted and complex. From the inflammatory response it drives to its dual roles in the heart, liver, and kidneys, AIM's functions may influence the development of cardiovascular disease. However, can this potentially beneficial protein be a protector of cardiovascular health, or is it the culprit of its potential harm? It deserves further exploration and thinking.
