Beta estradiol and norepinephrine treatment of differentiated SH-SY5Y cells enhances tau phosphorylation at (Ser396) and (Ser262) via AMPK but not mTOR signaling pathway

Abstract

Hyperphosphorylation of tau is one of the main hallmarks for Alzheimer's disease (AD) and many other tauopathies. Norepinephrine (NE), a stress-related hormone and 17-β-estradiol (E2) thought to influence tau phosphorylation (p-tau) and AD pathology. The controversy around the impact of NE and E2 requires further clarification. Moreover, the combination effect of physiological and psychological stress and estrogen alteration during menopause, which affect p-tau, has not been addressed. Exposure to E2 is believed to reduce NE release, however, the link between these two hormones and AD at cellular level was also remained unknown. Here, we examined whether NE and E2 treatment of differentiated SH-SY5Y cells affected tau phosphorylation. The involvement of adenosine monophosphate kinase protein kinase (AMPK) and target of Rapamycin (mTOR) as the possible mechanisms, underlying this effect was also investigated. Subsequent to SH-SY5Y differentiation to mature neurons, we treated the cells with NE, E2 and NE plus E2 in presence and absence of Compound C and Rapamycin. Cell viability was not affected by our treatment while our Western blot and immunofluorescent findings showed that exposure to NE and E2 separately, and in combination enhanced p-tau (Ser) and (Ser)/tau but not (Ser/Thr)/tau. Blocking AMPK by Compound C reduced p-tau (Ser) and (Ser), while GSK-3β and PP2A activities were remained unchanged. We also found that blocking mTOR by Rapamycin did not change increased p-tau (Ser) and (Ser) due to NE + E2 treatment. Collectively, our results suggested that tau hyperphosphorylation due to exposure to NE/E2 was mediated by AMPK, the main energy regulator of cells during stress with no significant involvement of mTOR, GSK-3β and PP2A.

Axonal TAU sorting requires the C-terminus of TAU but is independent of ANKG and TRIM46 enrichment at the AIS

“…The neuroblastoma cell line SH-SY5Y is human-derived 54 and cells can be differentiated with various substances into polarized neuronal cells (SH-SY5Y-derived neurons) at low cost 55 . SH-SY5Y-derived neurons express common neuronal maturation marker proteins [56][57][58][59][60][61] , including all six major human TAU isoforms 62,63 , show proper axonal TAU localization, and mimic the phosphorylation state of TAU in the adult human brain [64][65][66][67] . In brief, SH-SY5Y-derived neurons unite the benefits of a cell linei.e.…”

Tau protein plays a role in the mechanism of cognitive disorders induced by anesthetic drugs

“…Quantitative studies in vitro showed that the microtubule-binding capacity of tau protein decreased by 35, 25, and 10%, respectively, after phosphorylation at Ser262, Thr231, and Ser235 sites. Therefore, the phosphorylation site of tau protein plays an important role in tau protein-induced neurodegeneration (Haase et al, 2004;Stokin and Goldstein, 2006;Majd et al, 2018). According to the latest research, an interdependent relationship hypothesis has been reported.…”

Steroids and Alzheimer’s Disease: Changes Associated with Pathology and Therapeutic Potential

“…E2 treatment sustained tau hyperphosphorylation induced by protein kinase A activation in human embryonic kidney HEK293 cells stably expressing tau441 [ 96 ]. Similarly, it enhanced tau phosphorylation on several epitopes (Ser396, Ser262 but not Ser202/Thr205 (AT8)) through adenosine monophosphate protein kinase activation human SH-SH5Y neuroblastoma cells [ 97 ]. In contrast, it attenuated tau hyperphosphorylation at multiple sites (S396/404, Thr231, Thr205, S199/202) induced by transient GSK3β overexpression in mouse N2A neuroblastoma cells [ 98 ].…”