Extracellular vesicles from human urine-derived stem cells delay aging through the transfer of PLAU and TIMP1

Aging increases the risks of various diseases and the vulnerability to death.Cellular senescence is a hallmark of aging that contributes greatly to aging and aging-related diseases.This study demonstrates that extracellular vesicles from human urine-derived stem cells(USC-EVs)efficiently inhibit cellular senescence in vitro and in vivo.The intravenous injection of USC-EVs improves cognitive function,increases physical fitness and bone quality,and alleviates aging-related structural changes in different organs of senescence-accelerated mice and natural aging mice.The anti-aging effects of USC-EVs are not obviously affected by the USC donors’ages,genders,or health status.Proteomic analysis reveals that USC-EVs are enriched with plasminogen activator urokinase(PLAU)and tissue inhibitor of metalloproteinases 1(TIMP1).These two proteins contribute importantly to the anti-senescent effects of USC-EVs associated with the inhibition of matrix metalloproteinases,cyclin-dependent kinase inhibitor 2A(P16INK4a),and cyclin-dependent kinase inhibitor 1A(P21cip1).These findings suggest a great potential of autologous USC-EVs as a promising anti-aging agent by transferring PLAU and TIMP1 proteins.

Paraquat induces selective dopaminergic nigrostriatal degeneration in aging C57BL/6 mice

Background Paraquat （PQ; 1,1 ＇-dimethyl-4,4＇-bipyridinium）, a widely used herbicide that is structurally similar to the known dopaminergic neurotoxicant MPTP （1-methyl-l, 2, 3,6-tetrahydropyridine ）, has been suggested as a potential etiologic factor for the development of Parkinson＇ s disease （PD）. Aging is an accepted risk factor for idiopathic Parkinson＇ s disease. The aim of this study was to test the hypothesis that paraquat could induce PD-like nigrostriatal dopaminergic degeneration in aging C57BL/6 mice. Methods Senile male C57BL/6 mice were intraperitoneally injected with either saline or PQ at 2-day intervals for a total of 10 doses. Locomotor activity and performance on the pole test were measured 7 days after the last injection and animals were sacrificed one day later. Level of dopamine （DA） and its metabolites levels in the striatum were measured by high-performance liquid chromatography with an electrochemical detector （ HPLCECD）, and numbers of tyrosine hydroxylase （TH） positive neurons were estimated using immunohistochemistry. Results Locomotor activities were significantly decreased and the behavioral performance on the pole test were significantly impaired in the PQ treated group. Level of DA and its metabolites levels in the striatum were declined by 8 days after the last injection. Immunohistochemical analyses showed that PQ was associated with a reduction in numbers of tyrosine hydroxylase positive neurons. Conclusions Long-term repeated exposes to PQ can selectively impair the nigrostriatal dopaminergic system of senile mice, suggesting that PQ could play an important role in the pathogenesis of Parkinson＇ s disease （PD）. Our results also validate a novel model of PD induced by exposure to a toxic environmental agent.