Limits...
Hydrogen sulfide inhibits A2A adenosine receptor agonist induced β-amyloid production in SH-SY5Y neuroblastoma cells via a cAMP dependent pathway.

Nagpure BV, Bian JS - PLoS ONE (2014)

Bottom Line: NaHS induced reductions were accompanied by similar decreases in intracellular cAMP levels and phosphorylation of cAMP responsive element binding protein (CREB).NaHS significantly reduced the elevated cAMP and Aβ42 production caused by forskolin (an adenylyl cyclase, AC agonist) alone or forskolin in combination with IBMX (a phosphodiesterase inhibitor), but had no effect on those caused by IBMX alone.In conclusion, H2S attenuated HENECA induced Aβ42 production in SH-SY5Y neuroblastoma cells through inhibiting γ-secretase via a cAMP dependent pathway.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.

ABSTRACT
Alzheimer's disease (AD) is the leading cause of senile dementia in today's society. Its debilitating symptoms are manifested by disturbances in many important brain functions, which are influenced by adenosine. Hence, adenosinergic system is considered as a potential therapeutic target in AD treatment. In the present study, we found that sodium hydrosulfide (NaHS, an H2S donor, 100 µM) attenuated HENECA (a selective A2A receptor agonist, 10-200 nM) induced β-amyloid (1-42) (Aβ42) production in SH-SY5Y cells. NaHS also interfered with HENECA-stimulated production and post-translational modification of amyloid precursor protein (APP) by inhibiting its maturation. Measurement of the C-terminal APP fragments generated from its enzymatic cleavage by β-site amyloid precursor protein cleaving enzyme 1 (BACE1) showed that NaHS did not have any significant effect on β-secretase activity. However, the direct measurements of HENECA-elevated γ-secretase activity and mRNA expressions of presenilins suggested that the suppression of Aβ42 production in NaHS pretreated cells was mediated by inhibiting γ-secretase. NaHS induced reductions were accompanied by similar decreases in intracellular cAMP levels and phosphorylation of cAMP responsive element binding protein (CREB). NaHS significantly reduced the elevated cAMP and Aβ42 production caused by forskolin (an adenylyl cyclase, AC agonist) alone or forskolin in combination with IBMX (a phosphodiesterase inhibitor), but had no effect on those caused by IBMX alone. Moreover, pretreatment with NaHS significantly attenuated HENECA-elevated AC activity and mRNA expressions of various AC isoforms. These data suggest that NaHS may preferentially suppress AC activity when it was stimulated. In conclusion, H2S attenuated HENECA induced Aβ42 production in SH-SY5Y neuroblastoma cells through inhibiting γ-secretase via a cAMP dependent pathway.

Show MeSH

Related in: MedlinePlus

Effect of NaHS on production and maturation of APP.Representative gel (A) and quantitative analysis (B–C) showing the effects of NaHS (100 µM, 12 hours) on HENECA (100 nM, 24 hours) stimulated production (B) and maturation (C) of APP. The cell lysates were analysed by western blot technique with antibody against N-terminus of APP or β-actin. The extent of maturation of APP is shown as the ratio between mAPP to imAPP. mAPP and imAPP are represented by upper and lower bands in a blot respectively. β-actin was used as a loading control. Data are given as means ± S.E.M, n = 4. ###p<0.001 vs Con group; ***p<0.001 vs HEN group. Con, control; HEN, HENECA.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3921165&req=5

pone-0088508-g006: Effect of NaHS on production and maturation of APP.Representative gel (A) and quantitative analysis (B–C) showing the effects of NaHS (100 µM, 12 hours) on HENECA (100 nM, 24 hours) stimulated production (B) and maturation (C) of APP. The cell lysates were analysed by western blot technique with antibody against N-terminus of APP or β-actin. The extent of maturation of APP is shown as the ratio between mAPP to imAPP. mAPP and imAPP are represented by upper and lower bands in a blot respectively. β-actin was used as a loading control. Data are given as means ± S.E.M, n = 4. ###p<0.001 vs Con group; ***p<0.001 vs HEN group. Con, control; HEN, HENECA.

Mentions: We next sought to monitor the potential effects of H2S on post-translational modification (maturation), which is a major regulatory step in Aβ42 formation. During SDS-PAGE, both mature (mAPP) and immature (imAPP) forms of APP can be distinguished on the basis of their molecular weights. The immature form (N-glycosylated) is reported as ∼110 kD and mature form (N- and O- glycosylated) is ∼130 kD peptide [45]. As shown in Fig 6, HENECA significantly upregulated both holoprotein APP (imAPP + mAPP, Fig 6A & 6B) and the ratio of mAPP and imAPP (Fig 6A & 6C). Pretreatment with NaHS significantly abolished these effects. Thus, the effect of NaHS on HENECA-stimulated Aβ42 production is mediated by inhibition of both production and maturation of APP.


Hydrogen sulfide inhibits A2A adenosine receptor agonist induced β-amyloid production in SH-SY5Y neuroblastoma cells via a cAMP dependent pathway.

Nagpure BV, Bian JS - PLoS ONE (2014)

Effect of NaHS on production and maturation of APP.Representative gel (A) and quantitative analysis (B–C) showing the effects of NaHS (100 µM, 12 hours) on HENECA (100 nM, 24 hours) stimulated production (B) and maturation (C) of APP. The cell lysates were analysed by western blot technique with antibody against N-terminus of APP or β-actin. The extent of maturation of APP is shown as the ratio between mAPP to imAPP. mAPP and imAPP are represented by upper and lower bands in a blot respectively. β-actin was used as a loading control. Data are given as means ± S.E.M, n = 4. ###p<0.001 vs Con group; ***p<0.001 vs HEN group. Con, control; HEN, HENECA.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3921165&req=5

pone-0088508-g006: Effect of NaHS on production and maturation of APP.Representative gel (A) and quantitative analysis (B–C) showing the effects of NaHS (100 µM, 12 hours) on HENECA (100 nM, 24 hours) stimulated production (B) and maturation (C) of APP. The cell lysates were analysed by western blot technique with antibody against N-terminus of APP or β-actin. The extent of maturation of APP is shown as the ratio between mAPP to imAPP. mAPP and imAPP are represented by upper and lower bands in a blot respectively. β-actin was used as a loading control. Data are given as means ± S.E.M, n = 4. ###p<0.001 vs Con group; ***p<0.001 vs HEN group. Con, control; HEN, HENECA.
Mentions: We next sought to monitor the potential effects of H2S on post-translational modification (maturation), which is a major regulatory step in Aβ42 formation. During SDS-PAGE, both mature (mAPP) and immature (imAPP) forms of APP can be distinguished on the basis of their molecular weights. The immature form (N-glycosylated) is reported as ∼110 kD and mature form (N- and O- glycosylated) is ∼130 kD peptide [45]. As shown in Fig 6, HENECA significantly upregulated both holoprotein APP (imAPP + mAPP, Fig 6A & 6B) and the ratio of mAPP and imAPP (Fig 6A & 6C). Pretreatment with NaHS significantly abolished these effects. Thus, the effect of NaHS on HENECA-stimulated Aβ42 production is mediated by inhibition of both production and maturation of APP.

Bottom Line: NaHS induced reductions were accompanied by similar decreases in intracellular cAMP levels and phosphorylation of cAMP responsive element binding protein (CREB).NaHS significantly reduced the elevated cAMP and Aβ42 production caused by forskolin (an adenylyl cyclase, AC agonist) alone or forskolin in combination with IBMX (a phosphodiesterase inhibitor), but had no effect on those caused by IBMX alone.In conclusion, H2S attenuated HENECA induced Aβ42 production in SH-SY5Y neuroblastoma cells through inhibiting γ-secretase via a cAMP dependent pathway.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.

ABSTRACT
Alzheimer's disease (AD) is the leading cause of senile dementia in today's society. Its debilitating symptoms are manifested by disturbances in many important brain functions, which are influenced by adenosine. Hence, adenosinergic system is considered as a potential therapeutic target in AD treatment. In the present study, we found that sodium hydrosulfide (NaHS, an H2S donor, 100 µM) attenuated HENECA (a selective A2A receptor agonist, 10-200 nM) induced β-amyloid (1-42) (Aβ42) production in SH-SY5Y cells. NaHS also interfered with HENECA-stimulated production and post-translational modification of amyloid precursor protein (APP) by inhibiting its maturation. Measurement of the C-terminal APP fragments generated from its enzymatic cleavage by β-site amyloid precursor protein cleaving enzyme 1 (BACE1) showed that NaHS did not have any significant effect on β-secretase activity. However, the direct measurements of HENECA-elevated γ-secretase activity and mRNA expressions of presenilins suggested that the suppression of Aβ42 production in NaHS pretreated cells was mediated by inhibiting γ-secretase. NaHS induced reductions were accompanied by similar decreases in intracellular cAMP levels and phosphorylation of cAMP responsive element binding protein (CREB). NaHS significantly reduced the elevated cAMP and Aβ42 production caused by forskolin (an adenylyl cyclase, AC agonist) alone or forskolin in combination with IBMX (a phosphodiesterase inhibitor), but had no effect on those caused by IBMX alone. Moreover, pretreatment with NaHS significantly attenuated HENECA-elevated AC activity and mRNA expressions of various AC isoforms. These data suggest that NaHS may preferentially suppress AC activity when it was stimulated. In conclusion, H2S attenuated HENECA induced Aβ42 production in SH-SY5Y neuroblastoma cells through inhibiting γ-secretase via a cAMP dependent pathway.

Show MeSH
Related in: MedlinePlus