Human amniotic epithelial stem cells: Hepatic differentiation and regenerative properties in liver disease treatment

The placenta and the extraembryonic tissues represent a valuable source of cells for regenerative medicine. In particular, the amniotic membrane possesses cells with stem cells characteristics that have attracted research attention. Human amniotic epithelial cells (hAECs) have unique and desirable features that position them over other stem cells, not only because of the unlimited potential supplied of, the easy access to placental tissues, and the minimal ethical and legal barriers associated, but also due to the embryonic stem cells markers expression and their ability to differentiate into the three germ layers. In addition, they are non-tumorigenic and have immunomodulatory and anti-inflammatory properties. Hepatic failure is one of the major causes of morbidity and mortality worldwide. Organ transplantation is the best way to treat acute and chronic liver failure, but there are several associated obstacles. Stem cells have been highlighted as alternative hepatocytes source because of their potential for hepatogenic differentiation. HAECs, in particular, have some properties that make them suitable for hepatocyte differentiation. In this work, we review the general characteristics of the epithelial stem cells isolated from human amniotic membrane as well as their ability to differentiate to hepatic cells. We also revise their regenerative properties, with the focus on their potential application in the liver disease treatment.

Stem cells and COVID-19: are the human amniotic cells a new hope for therapies against the SARS-CoV-2 virus?

A new coronavirus respiratory disease (COVID-19) caused by the SARS-CoV-2 virus, surprised the entire world, producing social, economic, and health problems. The COVID-19 triggers a lung infection with a multiple proinflammatory cytokine storm in severe patients. Without effective and safe treatments, COVID-19 has killed thousands of people, becoming a pandemic. Stem cells have been suggested as a therapy for lung-related diseases. In particular, mesenchymal stem cells (MSCs) have been successfully tested in some clinical trials in patients with COVID-19. The encouraging results positioned MSCs as a possible cell therapy for COVID-19. The amniotic membrane from the human placenta at term is a valuable stem cell source, including human amniotic epithelial cells (hAECs) and human mesenchymal stromal cells (hAMSCs). Interestingly, amnion cells have immunoregulatory, regenerative, and anti-inflammatory properties. Moreover, hAECs and hAMSCs have been used both in preclinical studies and in clinical trials against respiratory diseases. They have reduced the inflammatory response and restored the pulmonary tissue architecture in lung injury in vivo models. Here, we review the existing data about the stem cells use for COVID-19 treatment, including the ongoing clinical trials. We also consider the non-cellular therapies that are being applied. Finally, we discuss the human amniotic membrane cells use in patients who suffer from immune/inflammatory lung diseases and hypothesize their possible use as a successful treatment against COVID-19.