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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.

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Effect of NaHS on activities of β- and γ-secretases.A–B: Representative gel (A) and quantitative analysis (B) showing NaHS (25–100 µM, 12 hours) and HENECA (100 nM, 24 hours) failed to affect β-CTF (C99) expression in SH-SY5Y cells. The membrane fractions were analysed by western blot with antibody against c-terminal fragment of APP (C99) or β-actin. C–D:Effect of NaHS (100 µM) and a γ-secretase inhibitor, DAPT (1 µM, 1 hour) on HENECA (100 nM)-stimulated γ-secretase activity (C) and Aβ42 formation (D) in SH-SY5Y cells expressing APPswe. E: Effect of NaHS (100 µM) on γ-secretase activity in SH-SY5Y cells preincubated with AC antagonist, SQ 22536 (300 µM). Data are given as means ± S.E.M, n = 4–6. ###p<0.001 vs Con group; ***p<0.001 vs HEN group. Con, control; HEN, HENECA.
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pone-0088508-g007: Effect of NaHS on activities of β- and γ-secretases.A–B: Representative gel (A) and quantitative analysis (B) showing NaHS (25–100 µM, 12 hours) and HENECA (100 nM, 24 hours) failed to affect β-CTF (C99) expression in SH-SY5Y cells. The membrane fractions were analysed by western blot with antibody against c-terminal fragment of APP (C99) or β-actin. C–D:Effect of NaHS (100 µM) and a γ-secretase inhibitor, DAPT (1 µM, 1 hour) on HENECA (100 nM)-stimulated γ-secretase activity (C) and Aβ42 formation (D) in SH-SY5Y cells expressing APPswe. E: Effect of NaHS (100 µM) on γ-secretase activity in SH-SY5Y cells preincubated with AC antagonist, SQ 22536 (300 µM). Data are given as means ± S.E.M, n = 4–6. ###p<0.001 vs Con group; ***p<0.001 vs HEN group. Con, control; HEN, HENECA.

Mentions: β –secretase cleavage of APP gives rise to production of β-C-terminal fragment, C99. Thus, the amount of C99 generated is considered as an index of β–secretase activity. As evident from Fig 7A and 7B, neither HENECA nor NaHS pretreatment (25–100 µM) was able to induce any significant change in C99 expression. This suggests that NaHS does not affect the activity of β–secretase in SH-SY5Y cells.


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 activities of β- and γ-secretases.A–B: Representative gel (A) and quantitative analysis (B) showing NaHS (25–100 µM, 12 hours) and HENECA (100 nM, 24 hours) failed to affect β-CTF (C99) expression in SH-SY5Y cells. The membrane fractions were analysed by western blot with antibody against c-terminal fragment of APP (C99) or β-actin. C–D:Effect of NaHS (100 µM) and a γ-secretase inhibitor, DAPT (1 µM, 1 hour) on HENECA (100 nM)-stimulated γ-secretase activity (C) and Aβ42 formation (D) in SH-SY5Y cells expressing APPswe. E: Effect of NaHS (100 µM) on γ-secretase activity in SH-SY5Y cells preincubated with AC antagonist, SQ 22536 (300 µM). Data are given as means ± S.E.M, n = 4–6. ###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-g007: Effect of NaHS on activities of β- and γ-secretases.A–B: Representative gel (A) and quantitative analysis (B) showing NaHS (25–100 µM, 12 hours) and HENECA (100 nM, 24 hours) failed to affect β-CTF (C99) expression in SH-SY5Y cells. The membrane fractions were analysed by western blot with antibody against c-terminal fragment of APP (C99) or β-actin. C–D:Effect of NaHS (100 µM) and a γ-secretase inhibitor, DAPT (1 µM, 1 hour) on HENECA (100 nM)-stimulated γ-secretase activity (C) and Aβ42 formation (D) in SH-SY5Y cells expressing APPswe. E: Effect of NaHS (100 µM) on γ-secretase activity in SH-SY5Y cells preincubated with AC antagonist, SQ 22536 (300 µM). Data are given as means ± S.E.M, n = 4–6. ###p<0.001 vs Con group; ***p<0.001 vs HEN group. Con, control; HEN, HENECA.
Mentions: β –secretase cleavage of APP gives rise to production of β-C-terminal fragment, C99. Thus, the amount of C99 generated is considered as an index of β–secretase activity. As evident from Fig 7A and 7B, neither HENECA nor NaHS pretreatment (25–100 µM) was able to induce any significant change in C99 expression. This suggests that NaHS does not affect the activity of β–secretase in SH-SY5Y cells.

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