MARCO+ Macrophage Dynamics in Regenerating Liver after 70% Liver Resection in Mice

Background: Macrophages play a key role in liver regeneration. The fates of resident macrophages after 70% resection are poorly investigated. In this work, using the MARCO macrophage marker (abbreviated from macrophage receptor with collagenous structure), we studied the dynamics of mouse liver resident macrophages after 70% resection. Methods: In BALB/c male mice, a model of liver regeneration after 70% resection was reproduced. The dynamics of markers CD68, TIM4, and MARCO were studied immunohistochemically and by using a Western blot. Results: The number of MARCO- and CD68-positive macrophages in the regenerating liver increased 1 day and 3 days after resection, respectively. At the same time, the content of the MARCO protein increased in the sorted macrophages of the regenerating liver on the third day. Conclusions: The data indicate that the number of MARCO-positive macrophages in the regenerating liver increases due to the activation of MARCO synthesis in the liver macrophages. The increased expression of MARCO by macrophages can be regarded as a sign of their activation. In the present study, stimulation with LPS led to an increase in the expression of the Marco gene in both Kupffer cells and macrophages of bone marrow origin.

Role of Nephronectin in Pathophysiology of Silicosis

Silicosis is a typical form of pneumoconiosis and is characterized as a type of lung fibrosis. Silica particles are captured and recognized upon by alveolar macrophages via the macrophage receptor with collagenous structure (MARCO) scavenger receptor, and thereafter the inflammasome is activated. Thereafter, various chemokines/cytokines play their roles to eventually form fibrosis. Additionally, silica particles chronically activate T helper cells which sets the background for the formation of silicosis-associated autoimmune disturbances. The occurrence and progression of lung fibrosis, the extracellular matrix-related molecules such as integrins and their ligands including fibronectin, vitronectin, laminin, and collagens, all play important roles. Here, the roles of these molecules in silicosis-related lung fibrosis are reviewed from the literature. Additionally, the measurement of serum nephronectin (Npnt), a new member of the integrin family of ligands, is discussed, together with investigations attempting to delineate the role of Npnt in silica-induced lung fibrosis. Serum Npnt was found to be higher in silicosis patients compared to healthy volunteers and seems to play a role in the progression of fibrosis with other cytokines. Therefore, serum Npnt levels may be employed as a suitable marker to monitor the progression of fibrosis in silicosis patients.

Study of Collagen Hydrogel Biodegradability Over Time

Hydrogels have drawn the interest of researchers over the past decade, due to their intrinsic properties for applications in medicine, agriculture [1,2], food industry, pharmaceuticals, environmental protection and biomaterials, etc. Obtaining hydrogels with collagen structure by hydrolyzing pelt waste and using them for applications in agriculture is a novelty, considering that the collagen structure is currently used only in medicine. The paper presents an experimental model for obtaining hydrogels with collagenous structure from pelt waste resulting from the liming process. As a biological material, the hydrogel with collagen structure is a complex medium, optimal for the development of a variety of biodeteriogenic organisms due to a considerable amount of protein as well as the presence of lipids and carbohydrates that provide an excellent nutrient substrate for many biological species. During the phase of incorporation into the soil of the collagen hydrogel, proteolytic bacteria develop particularly, stimulated by humidity and possibly by temperature, thus producing biodegradation.The paper presents the methodology for studying the biodegradability of collagen hydrogel with encapsulated nutrients.