Intramuscular Transplantation of Pig Amniotic Fluid-Derived Progenitor Cells Has Therapeutic Potential in a Mouse Model of Myocardial Infarction

Abstract

Acute myocardial infarction (MI) is a fatal event that causes a large number of deaths worldwide. MI results in pathological remodeling and decreased cardiac function, which could lead to heart failure and fatal arrhythmia. Cell therapy is a potential strategy to repair the damage through enhanced angiogenesis or by modulation of the inflammatory process via paracrine signaling. Amniotic fluid-derived progenitor cells (AFPCs) have been reported to differentiate into several lineages and can be used without ethical concerns or risk of teratoma formation. Since pigs are anatomically, physiologically, and genetically similar to humans, and pregnant pigs can be an abundant source of AFPCs, we used porcine AFPCs (pAFPCs) as our target cells. Intramyocardial injection of AFPCs has been shown to cure MI in animal models. However, intramuscular transplantation of cells has not been extensively investigated. In this study, we investigated the therapeutic potential of intramuscular injection of pAFPCs on acute MI. MI mice were divided into 1) PBS control, 2) medium cell dose (1 × 10 6 cells per leg; cell-M), and 3) high cell dose (4 × 10 6 cells per leg; cell-H) groups. Cells or PBS were directly injected into the hamstring muscle 20 min after MI surgery. Four weeks after MI surgery, the cell-M and cell-H groups exhibited significantly better ejection fraction, significantly greater wall thickness, smaller infarct scar sizes, and lower LV expansion index compared to the PBS group. Using in vivo imaging, we showed that the hamstring muscles from animals in the cell-M and cell-H groups had RFP-positive signals. In summary, intramuscular injection of porcine AFPCs reduced scar size, reduced pathological remodeling, and preserved heart function after MI.

Towards the standardization of stem cell therapy studies for ischemic heart diseases: Bridging the gap between animal models and the clinical setting

“…The advantages and limitations of each stem cell with regard to the possible emergence of ethical concerns (symbolized by ¥), the invasiveness and collection (from + to ++++), the isolation procedure, the abundance (from + to ++++), expansion and proliferation rate, the transdifferentiation capacity, the paracrine effects or/and cardiomyogenic potential, the survival and engraftment capacity as well as the immunogenic, oncogenic or teratogenic risks is given in the accessory side tables. The left table abridges bone marrow-derived stem cells [3,[19][20][21]27,28], cortical bone-derived stem cells [32,33], adipose tissue-derived stem cells [34,37,39,41] and gestation-related stem cells [42][43][44][45][46][47][48][49]51,54] and the right table abridges cardiac stem cells [57,59,60], skeletal muscle stem cells [62,63,66] and induced pluripotent stem cells [67,[69][70][71]. The human body scheme was constructed with images sourced from Servier Medical Art (http://www.servier.com/ Powerpoint-image-bank) and Cientic website (http://www.cientic.com/).…”

“…Pregnancy byproducts represent an important source of stem cells which can be obtained from a plethora of sources, such as placenta [42][43][44], chorionic plate [45], amniotic fluid [46], umbilical cord [47,48] and its blood [48][49][50][51]. These immune-privileged materials offer several advantages (Fig.…”

“…So far, few studies report the effects of different cell dosages and when they do, they are often limited to two-to-three specific doses (Supplementary Table 1). For instance, in a mouse model of AMI it was found that high doses of amniotic fluid-derived progenitor cells (4 × 10 6 cells) brought the best recovery of left ventricular structure and function [46]. Nonetheless, not always the higher dose is the best.…”

“…After being administered, cells can be nearly gone as soon as 1 to 3 days after transplantation [44,45]. However, some authors reported signs of stem cell survival up to 1 week [8,16,60,100,104], 1 month [14,18,23,27,30,37,46,52,67,105] and, most strikingly, up to 1 year [26]. When retained cells are quantified, we find that less than 3% of the stem cells survive more than 4 weeks [59,70] and that percentage drops to levels below 1% when the assessment is made 16 weeks after transplantation [106].…”

“…[21,57,58,61,111]) of cells but ICI (e.g. [15,30,34,76,102]), intravenous (IVI, [44,54]) and intramuscular injections [46] and epicardial delivery (e.g. [17,53,[64][65][66]) are routes of choice, too.…”