Different kinds of stem cells in the development of SARS-CoV-2 treatments

Figure 1 Stem cells in the development of severe acute respiratory syndrome coronavirus 2 treatments. Different kinds of stem cells (SCs), such as embryonic, mesenchymal, or artificial induced pluripotent SCs (iPSCs) or their products (SC exosomes), have been used in clinical trials and basic research to understand severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) behavior in humans. For example, Embryonic SCs (which can be differentiated in lung airway, lung alveolar, and intestinal epithelial cells or used for organoid development) and artificial iPSCs have been used in the progress of organogenesis knowledge, the comprehension of genetic alterations, pharmacological treatments or interactions, and the combination of SARS-CoV-2 in different kinds of cells (infection model). Mesenchymal SCs and SC exosomes have mainly been used in clinical trials as immunoregulators, and some authors have also stated their regeneration capability. SCs: Stem cells; iPSCs: Induced pluripotent SCs; SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2; ESCs: Embryonic stem cells; MSCs: Mesenchymal SCs.

Figure 2 Stem cells classification. According to their origin, stem cells (SCs) are divided into embryonic and adult cells. Embryonic SCs can be obtained from the zygote, morula, or the blastocyst's inner cell mass and possess high potentiality. Adult SCs can be isolated from neonatal and adult tissues (umbilical cord, placenta, bone marrow, adipose tissue, among others). Likewise, the induced pluripotent SCs are considered another kind of adult SCs once they are derived from adult somatic cells but have been genetically reprogrammed. Concerning their potentiality, SCs are divided into totipotent, pluripotent, multipotent, and oligopotent SCs. Thanks to artificial intelligence, the generation of artificial induced pluripotent SCs was reported. iPSCs: Induced pluripotent stem cells.