Diabetes mellitus and cellular replacement therapy: Expected clinical potential and perspectives

Table 1 Summary preclinical data among stem cell transplantation in diabetic animals

Type of cell replaced	Positive effect expected	Negative effect expected
Embryonic stem cells	Direct effect: Differentiation into functional insulin-producing cells Indirect effect: Improving of the fasting blood glucose due to restore the function of islet β cells Decreasing of blood lipid levels Increasing of serum C-peptide level Prevention of free-radical induced oxidative stress injury of beta-cells Improving of pancreatic microcirculation	Ethical problems Rejection High frequency of autoimmune-mediated destruction of the β cells and other autoimmune reactions High immunogenency Malignancy Potential tumor mediated effect
Pluripotent stem cells	Direct and indirect effects: See mentioned above	High frequency of rejection High immunogenency Low frequency of autoimmune-mediated destruction of the β cells and other autoimmune reactions Potential tumor mediated effect
Bone marrow derived mesenchymal stem cells	Direct and indirect effects: See mentioned above	Low frequency of autoimmune-mediated destruction of the β cells Moderate immunogenency Potential tumor mediated effect Low frequency of rejection
Adipose-derived stem cells	Direct and indirect effects: See mentioned above	Extremely low incidences in comparison with bone marrow derived mesenchymal stem cells of rejection, potential tumor mediated effect and autoimmune-mediated destruction of the β cells