Acellular human amniotic fluid protects the ischemic/reperfused rat myocardium

Proteomic Characterization of Cardioprotective Human Acellular Amniotic Fluid

Amniotic fluid-derived products are a promising resource for cell therapy and tissue engineering due to their anti-inflammatory, angiogenic, and antifibrotic properties. Human amniotic fluid (hAF) has been used in medical applications such as wound healing, skin disorders, and ophthalmic conditions. Recently, we demonstrated that hAF is an effective treatment for myocardial ischemia-reperfusion injury in adult rats. However, the protein composition of full-term acellular hAF has remained poorly characterized. To uncover the biologically active components underlying hAF's cardioprotective effects, we conducted a global proteomic analysis of hAF collected from six patients at full-term cesarean sections. Previously shown to improve cardiac function in ischemic rats, these samples were analyzed by using tandem mass spectrometry. We identified 657 proteins, including 148 unique to the deep learning platform Inferys. Bioinformatic analysis revealed that these proteins are involved in immunity, inflammatory responses, cell adhesion, and apoptotic signaling pathways. In addition, these proteins were highly modified, with methylation and deamidation being the most abundant modifications. This study represents the first mass-spectrometry-based characterization of full-term, acellular hAF, suggesting that hAF offers a wide array of immune-modulating proteins working together to provide robust cardioprotection and a valuable treatment for ischemia-reperfusion injury.

High-impact opportunities to address ischemia: a focus on heart and circulatory research

Myocardial ischemic injury and its resolution are the key determinants of morbidity or mortality in heart failure. The cause and duration of ischemia in patients vary. Numerous experimental models and methods have been developed to define genetic, metabolic, molecular, cellular, and pathophysiological mechanisms, in addition to defining structural and functional deterioration of cardiovascular performance. The rapid rise of big data, such as single-cell analysis techniques with bioinformatics, machine learning, and neural networking, brings a new level of sophistication to our understanding of myocardial ischemia. This mini-review explores the multifaceted nature of ischemic injury in the myocardium. We highlight recent state-of-the-art findings and strategies to show new directions of high-impact approach to understanding myocardial tissue remodeling. This next age of heart and circulatory physiology research will be more comprehensive and collaborative to uncover the origin, progression, and manifestation of heart failure while strengthening novel treatment strategies.

Cell-Free Amniotic Fluid and Regenerative Medicine: Current Applications and Future Opportunities

Amniotic fluid (AF) provides critical biological and physical support for the developing fetus. While AF is an excellent source of progenitor cells with regenerative properties, recent investigations indicate that cell-free AF (cfAF), which consists of its soluble components and extracellular vesicles, can also stimulate regenerative and reparative activities. This review summarizes published fundamental, translational, and clinical investigations into the biological activity and potential use of cfAF as a therapeutic agent. Recurring themes emerge from these studies, which indicate that cfAF can confer immunomodulatory, anti-inflammatory, and pro-growth characteristics to the target cells/tissue with which they come into contact. Another common observation is that cfAF seems to promote a return of cells/tissue to a homeostatic resting state when applied to a model of cell stress or disease. The precise mechanisms through which these effects are mediated have not been entirely defined, but it is clear that cfAF can safely and effectively treat cutaneous wounds and perhaps orthopedic degenerative conditions. Additional applications are currently being investigated, but require further study to dissect the fundamental mechanisms through which its regenerative effects are mediated. By doing so, rational design can be used to fully unlock its potential in the biotechnology lab and in the clinic.

Comparative Analysis of Co-Cultured Amniotic Cell-Conditioned Media with Cell-Free Amniotic Fluid Reveals Differential Effects on Epithelial–Mesenchymal Transition and Myofibroblast Activation

Myofibroblast activation is a cellular response elicited by a variety of physiological or pathological insults whereby cells initiate a coordinated response intended to eradicate the insult and then revert back to a basal state. However, an underlying theme in various disease states is persistent myofibroblast activation that fails to resolve. Based on multiple observations, we hypothesized that the secreted factors harvested from co-culturing amniotic stem cells might mimic the anti-inflammatory state that cell-free amniotic fluid (AF) elicits. We optimized an amnion epithelial and amniotic fluid cell co-culture system, and tested this hypothesis in the context of myofibroblast activation. However, we discovered that co-cultured amniotic cell conditioned media (coACCM) and AF have opposing effects on myofibroblast activation: coACCM activates the epithelial–mesenchymal transition (EMT) and stimulates gene expression patterns associated with myofibroblast activation, while AF does the opposite. Intriguingly, extracellular vesicles (EVs) purified from AF are necessary and sufficient to activate EMT and inflammatory gene expression patterns, while the EV-depleted AF potently represses these responses. In summary, these data indicate that coACCM stimulates myofibroblast activation, while AF represses it. We interpret these findings to suggest that coACCM, AF, and fractionated AF represent unique biologics that elicit different cellular responses that are correlated with a wide variety of pathological states, and therefore could have broad utility in the clinic and the lab.