Abstract
The amyloid peptides Abeta1-42 and Abeta25-35 strongly inhibited the activity of constitutive neuronal and endothelial nitric oxide synthases (i.e., NOS-I and NOS-III, respectively) in cell-free assays. The molecular mechanism of NOS inhibition by Ab fragments was studied in detail with Abeta25-35. The inhibitory ability was mostly NADPH-dependent and specific for the soluble form of Abeta25-35. Optical, fluorescence, and NMR spectroscopy showed that the soluble, but not aggregated, Abeta25-35 interacted with NADPH, thus suggesting that a direct recruitment of NADPH may result in diminished availability of the redox cofactor for NOS functioning. To assess the physiological relevance of our findings, rat neuronal-like PC12 and glioma C6 cell lines were used as cellular models. After Abeta25-35 internalization into cells was verified, the activity of constitutive NOS was measured using the DAF-2DA detection system and found to be severely impaired upon Abeta25-35 uptake. Consistent with previous results on the molecular cross-talk between NOS isoforms, repression of constitutive NOS by Abeta25-35 resulted in enhanced expression of inducible NOS (NOS-II) mRNA in C6 cells. Our results represent the first evidence that amyloid fragments impair constitutive NOS activity in cell-free and cellular systems, providing a possible molecular mechanism for the onset and/or maintenance of Alzheimer's disease.
| Original language | English |
|---|---|
| Pages (from-to) | 1970-1972 |
| Number of pages | 3 |
| Journal | FASEB Journal |
| Volume | 16 |
| Issue number | 14 |
| Publication status | Published - 2002 |
Fingerprint
Cite this
Beta-amyloid inhibits NOS activity by subtracting NADPH availability. / Venturini, Giorgio; Colasanti, Marco; Persichini, Tiziana; Fioravanti, Emanuela; Ascenzi, Paolo; Palomba, Letizia; Cantoni, Orazio; Musci, Giovanni.
In: FASEB Journal, Vol. 16, No. 14, 2002, p. 1970-1972.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Beta-amyloid inhibits NOS activity by subtracting NADPH availability.
AU - Venturini, Giorgio
AU - Colasanti, Marco
AU - Persichini, Tiziana
AU - Fioravanti, Emanuela
AU - Ascenzi, Paolo
AU - Palomba, Letizia
AU - Cantoni, Orazio
AU - Musci, Giovanni
PY - 2002
Y1 - 2002
N2 - The amyloid peptides Abeta1-42 and Abeta25-35 strongly inhibited the activity of constitutive neuronal and endothelial nitric oxide synthases (i.e., NOS-I and NOS-III, respectively) in cell-free assays. The molecular mechanism of NOS inhibition by Ab fragments was studied in detail with Abeta25-35. The inhibitory ability was mostly NADPH-dependent and specific for the soluble form of Abeta25-35. Optical, fluorescence, and NMR spectroscopy showed that the soluble, but not aggregated, Abeta25-35 interacted with NADPH, thus suggesting that a direct recruitment of NADPH may result in diminished availability of the redox cofactor for NOS functioning. To assess the physiological relevance of our findings, rat neuronal-like PC12 and glioma C6 cell lines were used as cellular models. After Abeta25-35 internalization into cells was verified, the activity of constitutive NOS was measured using the DAF-2DA detection system and found to be severely impaired upon Abeta25-35 uptake. Consistent with previous results on the molecular cross-talk between NOS isoforms, repression of constitutive NOS by Abeta25-35 resulted in enhanced expression of inducible NOS (NOS-II) mRNA in C6 cells. Our results represent the first evidence that amyloid fragments impair constitutive NOS activity in cell-free and cellular systems, providing a possible molecular mechanism for the onset and/or maintenance of Alzheimer's disease.
AB - The amyloid peptides Abeta1-42 and Abeta25-35 strongly inhibited the activity of constitutive neuronal and endothelial nitric oxide synthases (i.e., NOS-I and NOS-III, respectively) in cell-free assays. The molecular mechanism of NOS inhibition by Ab fragments was studied in detail with Abeta25-35. The inhibitory ability was mostly NADPH-dependent and specific for the soluble form of Abeta25-35. Optical, fluorescence, and NMR spectroscopy showed that the soluble, but not aggregated, Abeta25-35 interacted with NADPH, thus suggesting that a direct recruitment of NADPH may result in diminished availability of the redox cofactor for NOS functioning. To assess the physiological relevance of our findings, rat neuronal-like PC12 and glioma C6 cell lines were used as cellular models. After Abeta25-35 internalization into cells was verified, the activity of constitutive NOS was measured using the DAF-2DA detection system and found to be severely impaired upon Abeta25-35 uptake. Consistent with previous results on the molecular cross-talk between NOS isoforms, repression of constitutive NOS by Abeta25-35 resulted in enhanced expression of inducible NOS (NOS-II) mRNA in C6 cells. Our results represent the first evidence that amyloid fragments impair constitutive NOS activity in cell-free and cellular systems, providing a possible molecular mechanism for the onset and/or maintenance of Alzheimer's disease.
UR - http://www.scopus.com/inward/record.url?scp=0036884511&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036884511&partnerID=8YFLogxK
M3 - Article
VL - 16
SP - 1970
EP - 1972
JO - FASEB Journal
JF - FASEB Journal
SN - 0892-6638
IS - 14
ER -