Herbal pre-conditioning induces proliferation and delays senescence in Wharton's Jelly Mesenchymal Stem Cells

BACKGROUND

Mesenchymal Stem Cells (MSCs) are multipotent stem cells which are being explored for various clinical applications. Isolation and in-vitro expansion of MSCs remain important in achieving desired cell number for the therapy. However, in-vitro proliferation of MSCs is often associated with senescence and early onset of apoptosis which limits its therapeutic ability and long term clinical use. Tinospora cordifolia and Withania somnifera are used widely in Ayurveda: the traditional Indian system of medicine and are reported to have rejuvenating and anti-aging potential. In the present study, we investigated the effect of Tinospora cordifolia and Withania somnifera on proliferation and senescence of wharton's jelly MSCs (WJMSCs) in-vitro.

METHODS

WJMSCs were treated in culture medium with Tinospora cordifolia leaf and Withania somnifera root extracts to examine their effect on proliferation and senescence properties of WJMSCs. Proliferation of WJMSCs was assayed by cell count, MTT, BrdU incorporation assay, cell cycle analysis and Ki67 mRNA expression. Senescence was demonstrated using β-galactosidase senescence assay and associated mRNA markers.

RESULTS

Culture medium supplemented with Tinospora cordifolia leaf and Withania somnifera root extracts exhibited significant increase in proliferation of WJMSCs as evidenced by cell count and MTT assay. Cell cycle analysis using propidium iodide showed increase in G2/M phase and decrease in apoptotic cells. BrdU incorporation and upregulation of proliferation marker ki67 by RT PCR showed increased DNA synthesis/proliferation in Tinospora cordifolia and Withania somnifera extract treated MSCs. Delayed senescence was confirmed by β-galactosidase senescence assay and down regulation of senescence marker p21.

CONCLUSION

Our results demonstrate for the first time that Tinospora cordifolia and Withania somnifera extracts support proliferation and inhibit senescence in WJMSCs making them suitable candidates as supplements for in-vitro expansion without affecting the cell viability indicating its non-toxic nature.

Abnormal vibrissa-related behavior and loss of barrel field inhibitory neurons in 5xFAD transgenics

A recent study reported lower anxiety in the 5xFAD transgenic mouse model of Alzheimer's disease, as measured by reduced time on the open arms of an elevated plus maze. This is important because all behaviors in experimental animals must be interpreted in light of basal anxiety and response to novel environments. We conducted a comprehensive anxiety battery in the 5xFAD transgenics and replicated the plus-maze phenotype. However, we found that it did not reflect reduced anxiety, but rather abnormal avoidance of the closed arms on the part of transgenics and within-session habituation to the closed arms on the part of wild-type controls. We noticed that the 5xFAD transgenics did not engage in the whisker-barbering behavior typical of mice of this background strain. This is suggestive of abnormal social behavior, and we suspected it might be related to their avoidance of the closed arms on the plus maze. Indeed, transgenic mice exhibited excessive home-cage social behavior and impaired social recognition, and did not permit barbering by wild-type mice when pair-housed. When their whiskers were snipped the 5xFAD transgenics no longer avoided the closed arms on the plus maze. Examination of parvalbumin (PV) staining showed a 28.9% reduction in PV+ inhibitory interneurons in the barrel fields of 5xFAD mice, and loss of PV+ fibers in layers IV and V. This loss of vibrissal inhibition suggests a putatively aversive overstimulation that may be responsible for the transgenics' avoidance of the closed arms in the plus maze.

A single intramuscular injection of rAAV-mediated mutant erythropoietin protects against MPTP-induced parkinsonism

Erythropoietin (Epo) is neuroprotective in a number of preparations, but can lead to unacceptably high and even lethal hematocrit levels. Recent reports show that modified Epo variants confer neuroprotection in models of glaucoma and retinal degeneration without raising hematocrit. In this study, neuroprotective effects of two Epo variants (EpoR76E and EpoS71E) were assessed in a model of Parkinson's disease. The constructs were packaged in recombinant adeno-associated viral (rAAV) vectors and injected intramuscularly. After 3 weeks, mice received five daily injections of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and were killed 5 weeks later. The MPTP-lesioned mice pretreated with rAAV.eGFP (negative control) exhibited a 7- to 9-Hz tremor and slower latencies to move on a grid test (akinesia). Both of these symptomatic features were absent in mice pretreated with either modified Epo construct. The rAAV.eGFP-treated mice lesioned with MPTP exhibited a 41% reduction in tyrosine hydroxylase (TH)-positive neurons in the substantia nigra. The rAAV.EpoS71E construct did not protect nigral neurons, but neuronal loss in mice pretreated with rAAV.EpoR76E was only half that of rAAV.eGFP controls. Although dopamine levels were normal in all groups, 3,4-dihydroxyphenylacetic acid (DOPAC) was significantly reduced only in MPTP-lesioned mice pretreated with rAAV.eGFP, indicating reduced dopamine turnover. Analysis of TH-positive fibers in the striatum showed normalized density in MPTP-lesioned mice pretreated with rAAV.EpoS71E, suggesting that enhanced sprouting induced by EpoS71E may have been responsible for normal behavior and dopaminergic tone in these mice. These results show that systemically administered rAAV-generated non-erythropoietic Epo may protect against MPTP-induced parkinsonism by a combination of neuroprotection and enhanced axonal sprouting.