Mesenchymal stem cells (MSCs) have been shown to have therapeutic efficacy in different complex pathologies in feline species. This effect is attributed to the secretion of a wide variety of bioactive molecules and extracellular vesicles, such as exosomes, with significant paracrine activity, encompassed under the concept of the secretome. However, at present, the exosomes from feline MSCs have not yet been studied in detail. The objective of this study is to analyze and compare the protein profiles of the secretome as a whole and its exosomal fraction from feline adipose-derived MSCs (fAd-MSCs). For this, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and Protein–Protein Interaction Networks Functional Enrichment Analysis (STRING) were utilized. A total of 239 proteins were identified in the secretome, and 228 proteins specific to exosomes were identified, with a total of 133 common proteins. The proteins identified in the secretome were located in the extracellular regions and in the cytoplasm, while the exosomal proteins were located mainly in the membrane, cytoplasm and cytosol. Regarding function, in the secretome, proteins involved in different metabolic pathways, in pathways related to the immune system and the endocrine system and in the processing of proteins in the endoplasmic reticulum predominated. In contrast, proteins specific to exosomes were predominantly associated with endocytosis, cell junctions, platelet activation and other cell signaling pathways. The possible future use of the secretome, or some of its components, such as exosomes, would provide a non-cell-based therapeutic strategy for the treatment of different diseases that would avoid the drawbacks of cell therapy.

中文翻译：

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猫脂肪来源的间充质干细胞分泌和外泌体的蛋白质组学分析

间充质干细胞（MSCs）已显示在猫科动物的不同复杂病理中具有治疗功效。该作用归因于分泌组概念所涵盖的具有显着旁分泌活性的多种生物活性分子和细胞外囊泡（如外泌体）的分泌。然而，目前，尚未对来自猫MSC的外泌体进行详细研究。这项研究的目的是分析和比较从猫脂肪来源的MSCs（fAd-MSCs）整体来看，分泌蛋白的蛋白质谱及其外泌体组分。为此，利用了基因本体论（GO），《京都基因与基因组百科全书》（KEGG）和蛋白质-蛋白质相互作用网络功能性富集分析（STRING）。分泌组中总共鉴定出239种蛋白质，鉴定出了228种特定于外泌体的蛋白质，共有133种常见蛋白质。在分泌组中鉴定出的蛋白质位于细胞外区域和细胞质中，而外泌体蛋白质主要位于膜，细胞质和细胞质中。关于功能，在分泌组中，蛋白质参与不同的代谢途径，与免疫系统和内分泌系统有关的途径以及在内质网中蛋白质的加工中占主导地位。相反，特异于外泌体的蛋白质主要与胞吞作用，细胞连接，血小板活化和其他细胞信号通路相关。分泌蛋白或其某些成分（如外泌体）在未来的可能用途，