Strategies to improve regenerative potential of mesenchymal stem cells

Table 1 Oxygen concentrations in various stem cells niches

Tissue/Organ	Oxygen concentration	Ref.
Adipose tissue (source: ASCs)	2%-10%	[31]
Bone marrow (source: MSCs)	1%-6%	[32,33]
Eye (retina, corpus vitreous) (Source: Limbal stem cells)	1%-5%	[119,120]
Brain (source: Neural stem cells)	0.5%-8%	[121,122]
Heart (source: Cardiac progenitor cells)	4%-14%	[123]
Kidney (source: Renal stem/progenitor cells)	4%-14%	[124]
Liver (source: Liver stem cells)	4%-14%	[125]
Umbilical veins and arteries	2.4%-3.8%	[126]

MSCs: Mesenchymal stem cells.

Table 2 Effect of glucose concentrations on cells

Glucose concentration	Major findings	Cell types	Ref.
Glucose free and 4.5 g/L	Glucose depletion enhances proliferation, delays senescence and restores ability of aged cells to repair senescent infarcted myocardium	Mouse bone marrow derived MSCs	[109]
0.25, 0.5, 1.0 and 4.5 g/L	High glucose decreases viability while low glucose concentration retains high proliferative and differentiation capability of cells	Rat bone marrow derived MSCs	[110]
5.56 mmol/L, 13.9 mmol/L, 27.8 mmol/L, and 55.6 mmol/L	Decrease in population doublings and CFUs. Increased senescence in high glucose	Human adipose tissue derived MSCs	[111]
5.5 mM and 25 mM	No negative impact on population doublings and expansion. Increased senescence, inhibit osteogenic and adipogenic differentiation potential	Endosteal niche lining compact bone cells (CB-MSCs)	[112]
1 g/L and 4.5 g/L	Decreased proliferation, increased apoptosis and senescence	Nucleus pulpous-derived MSCs	[113]
5.5 mM and 35 mM	Increased apoptosis	Human periodontal ligament fibroblasts	[114]
5 mM/L and 25 mM/L	Increased oxidative stress	Mesangial cells	[118]

MSCs: Mesenchymal stem cells.