Interaction of AIM with insulin-like growth factor-binding protein-4

The effects of apoptosis inhibitor of macrophage in kidney diseases

Kidney disease is a progressive and irreversible condition in which immunity is a contributing factor that endangers human health. It is widely acknowledged that macrophages play a significant role in developing and causing numerous kidney diseases. The increasing focus on the mechanism by which macrophages express apoptosis inhibitor of macrophages (AIM) in renal diseases has been observed. AIM is an apoptosis inhibitor that stops different things that cause apoptosis from working. This keeps AIM-bound cell types alive. Notably, the maintenance of immune cell viability regulates immunity. As our investigation progressed, we concluded that AIM has two sides when it comes to renal diseases. AIM can modulate renal phagocytosis, expedite the elimination of renal tubular cell fragments, and mitigate tissue injury. AIM can additionally exacerbate the development of renal fibrosis and kidney disease by prolonging inflammation. IgA nephropathy (IgAN) may also worsen faster if more protein is in the urine. This is because IgA and immunoglobulin M are found together and expressed. In the review, we provide a comprehensive overview of prior research and concentrate on the impacts of AIM on diverse subcategories of nephropathies. We discovered that AIM is closely associated with renal diseases by playing a positive or negative role in the onset, progression, or cure of kidney disease. AIM is thus a potentially effective therapeutic target for kidney diseases.

Serum level of apoptosis inhibitor of macrophage in dogs with histiocytic sarcoma and its association with the disease

Histiocytic sarcoma (HS) is a rare neoplasm of macrophages or dendritic cells with a poor prognosis in dogs. As the apoptosis inhibitor of macrophage (AIM) is characteristically expressed in canine macrophages, we hypothesised that AIM is involved in the development or progression of HS in dogs. In this study, AIM expression in the tumour region and serum AIM levels in dogs with HS was assessed. Additionally, the effects of AIM overexpression on HS cell viability were investigated using a HS cell line that was selected from five validated HS cell lines. Immunohistochemistry showed that AIM expression was observed in the cytoplasm of the HS cells. CD36, a candidate AIM receptor, was also observed on the cell membrane of HS cells. When the serum AIM level was detected in 36 dogs with HS and 10 healthy dogs via western blot analysis, the AIM levels in the HS dogs were significantly higher than those in the controls. AIM mRNA expression in the 5 HS cell lines varied but was higher than that in the other tumour-derived lines. Among the five HS cell lines, DH82 originally had lower AIM and the highest CD36 expression. When AIM was overexpressed in DH82, therein cell growth speed and invasion, apoptosis inhibition and phagocytic activity were strongly upregulated. These data suggest that elevated intra-tumour expression of AIM could induce the progression of HS cells in dogs. Moreover, elevated serum AIM levels in dogs with HS could serve as a biomarker of HS.

Cancer Stem Cells: Emergent Nature of Tumor Emergency

A functional analysis of 167 genes overexpressed in Krebs-2 tumor initiating cells was performed. In the first part of the study, the genes were analyzed for their belonging to one or more of the three groups, which represent the three major phenotypic manifestation of malignancy of cancer cells, namely (1) proliferative self-sufficiency, (2) invasive growth and metastasis, and (3) multiple drug resistance. 96 genes out of 167 were identified as possible contributors to at least one of these fundamental properties. It was also found that substantial part of these genes are also known as genes responsible for formation and/or maintenance of the stemness of normal pluri-/multipotent stem cells. These results suggest that the malignancy is simply the ability to maintain the stem cell specific genes expression profile, and, as a consequence, the stemness itself regardless of the controlling effect of stem niches. In the second part of the study, three stress factors combined into the single concept of "generalized cellular stress," which are assumed to activate the expression of these genes, were defined. In addition, possible mechanisms for such activation were identified. The data obtained suggest the existence of a mechanism for the de novo formation of a pluripotent/stem phenotype in the subpopulation of "committed" tumor cells.

Orchestrating Role of Apoptosis Inhibitor of Macrophage in the Resolution of Acute Lung Injury

Appropriate resolution of inflammation is known to be essential in tissue homeostasis. In this study, we evaluated the significance of a macrophage-derived soluble protein, apoptosis inhibitor of macrophage (AIM), in LPS-induced lung injury in mice. After oropharyngeal administration of LPS, the level of free-form serum AIM increased on days 2-4, accompanied by the resolution of inflammation, which was observed in the cellular profile of bronchoalveolar lavage fluid. In an experiment using wild-type (WT) and AIM^-/- mice, the resolution of inflammation was accelerated in AIM^-/- mice when compared with the WT mice, which was reversed when recombinant AIM protein was administered. The changes in the histopathological findings and inflammatory mediators followed similar trends, and the ratio of apoptotic cells was increased in AIM^-/- mice when compared with the WT mice. In vitro analysis showed that macrophage phagocytosis of apoptotic neutrophils was suppressed in the presence of AIM, indicating that anti-resolution property of AIM involves efferocytosis inhibition. In lipidomic analysis of lung tissues, the levels of several lipid mediators increased markedly when LPS was given to WT mice. However, in AIM^-/- mice, the concentrations of these lipid mediators were not significantly upregulated by LPS. These data reflect the significant role of AIM in lipid metabolism; it may suppress lipid metabolites at baseline, and then produce an inflammatory/pathologic pattern in the event of LPS-induced lung injury. Taken together, AIM may play an orchestrating role in the resolution process of inflammation by altering the profile of pulmonary lipid mediators in mice.