Enhancement of Replication and Differentiation Potential of Human Bone Marrow Stem Cells by Nicotinamide Treatment

Abstract

Background and ObjectivesTherapies using mesenchymal stem cells (MSCs) generally require substantial expansion of cell populations. However, the replicative life span of MSCs is limited and their multipotency declines over continued passages, imposing a limitation on their application especially in aged individuals. In an effort to increase MSC life span, we tested the effects of nicotinamide (NAM), a precursor of NAD+ that has been shown to reduce reactive oxygen species generation and delay the onset of replicative senescence in fibroblasts.MethodsBone marrow stem cells (BMSCs) from healthy donors were cultivated in the presence of 5 mM NAM until the end of their life span. The levels of proliferation and differentiation to osteogenic, adipogenic, and chondrogenic lineages of BMSCs were compared between populations incubated in the absence or presence of NAM.ResultsThe replicative life span was substantially increased with a significant delay in the onset of senescence, and differentiation to all tested lineages was increased. Furthermore, differentiation was sustained and the adipogenic switch from osteogenesis to adipogenesis was attenuated in late-passage BMSCs.ConclusionsNAM could be considered as an important biological agent to expand and sustain the multipotency of BMSCs and thus broaden the application of stem cells in cell therapies.

AICAR and nicotinamide treatment synergistically augment the proliferation and attenuate senescence-associated changes in mesenchymal stromal cells

“…Senescent cells often exhibit a characteristic accumulation of dysfunctional autophagolysosomes, portrayed as a yellowish-green granulated cytoplasm when treated with Acridine Orange [1,30,36], as seen in the control group. Altogether, our data is consistent with the literature [11,24], as treatment with senolytics AICAR and NAM, especially AICAR, prevented most of the morphological features of senescence in our MSCs, as shown by smaller cell surface area, lower frequency of SA-β-gal-positive cells, and accumulation of autophagolysosomes in the cytoplasm.…”

“…For instance, García-Prat et al showed that treating old mice with a rapamycin regimen increased autophagy and re-established cell proliferation [18]. Additionally, Ok et al demonstrated that human bone marrow MSCs treated with NAM had increased autophagy [24]. According to Morselli et al, increasing autophagy is an integral part of the geroprotection, and without it, senolytics would not show any apparent protection against aging [59].…”

“…Then, the cells were washed with PBS and observed under the microscope for visualization. Stained oil droplets were dissolved in isopropanol for 15 min, and absorbance at 518 nm was evaluated, using NanoDrop 2000c Spectrophotometer (Thermo Fisher Scientific) [24].…”

“…AMPK then phosphorylates the regulatory-associated protein of TOR (Raptor) on Ser722/Ser792 to attenuate the mTORC1 activity [22,23]. Nicotinamide (NAM), which is converted to NAD + in cells, can enhance the in vitro replication and multilineage differentiation capacity of human bone marrow stem cells through activation of SIRT1 [24]. Also, NAM can prevent the senescence of human primary keratinocytes and increase their proliferative potential [25].…”

Nicotinamide Metabolism Modulates the Proliferation/Differentiation Balance and Senescence of Human Primary Keratinocytes

“…This effect seems to occur through positive modulation of mitochondrial oxidative phosphorylation (OXPHOS) (Zhang et al, 2016), but how OXPHOS prevents stem cell senescence is yet to be determined. Moreover, NAM has recently been shown to increase lifespan of mesenchymal stem cells by delaying replicative senescence (Ok et al, 2018).…”