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NADPH-oxidase activation and cognition in Alzheimer disease progression
Ansari MA, Scheff SW.. Free radical biology & medicine, 2011-03-30
Topic: Amyloid, tau and blood-test diagnosis
Superoxide production via NADPH-oxidase (NOX) has been shown to play a role in a variety of neurological disorders, including Alzheimer disease (AD). To improve our understanding of the NOX system and cognitive impairment, we studied the various protein components of the phagocytic isoform (gp91(phox), or NOX2) in the frontal and temporal cortex of age- and postmortem-matched samples. Individuals underwent antemortem cognitive testing and postmortem histopathologic assessment to determine disease progression and assignment to one of the following groups: no cognitive impairment (NCI), preclinical AD, mild cognitive impairment (MCI), early AD, and mild-to-moderate AD. Biochemical methods were used to determine overall NOX activity as well as levels of the various subunits (gp91(phox), p67(phox), p47(phox), p40(phox), and p22(phox)). Overall enzyme activity was significantly elevated in the MCI cohort in both cortical regions compared to the NCI cohort. This activity level remained elevated in the AD groups. Only the NOX cytosolic subunit proteins (p67(phox), p47(phox), and p40(phox) ) were significantly elevated with disease progression; the membrane-bound subunits (gp91(phox) and p22(phox)) remained stable. In addition, there was a robust correlation between NOX activity and the individual's cognitive status such that as the enzyme activity increased, cognitive performance decreased. Collectively, these data show that upregulated NADPH-oxidase in frontal and temporal cortex suggests that increases in NOX-associated redox pathways might participate in early pathogenesis and contribute to AD progression.
Key findings
- Biochemical methods were used to determine overall NOX activity as well as levels of the various subunits (gp91(phox), p67(phox), p47(phox), p40(phox), and p22(phox)).
- Overall enzyme activity was significantly elevated in the MCI cohort in both cortical regions compared to the NCI cohort.
- Only the NOX cytosolic subunit proteins (p67(phox), p47(phox), and p40(phox) ) were significantly elevated with disease progression; the membrane-bound subunits (gp91(phox) and p22(phox)) remained stable.
- Collectively, these data show that upregulated NADPH-oxidase in frontal and temporal cortex suggests that increases in NOX-associated redox pathways might participate in early pathogenesis and contribute to AD progression.
Why it matters
This study found that NADPH-oxidase enzyme activity was elevated in the brain tissue of people with mild cognitive impairment and Alzheimer's disease compared to those with no cognitive impairment. The findings describe a biological change associated with disease progression but do not test any treatment or prevention.
Study details
- Evidence strengthModerate
How this study scored 44/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Free radical biology & medicine) |
| Journal's citation record | 3 / 4 | Free Radical Biology and Medicine: journal h-index 378 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2011 — within 20 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 131 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 7.7 citations a year over 17 year(s) since 2011 |
| Impact for its field and year | 3 / 6 | Cited 6.6× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 4 other studies in this library |
| Still being cited | 2 / 4 | Cited 16 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 3 / 4 | Last-listed author Stephen W. Scheff: h-index 86 (OpenAlex, whole career) |
| Institution's track record | 1 / 3 | University of Kentucky: institution h-index 824 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 21457777) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 44 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1016/j.freeradbiomed.2011.03.025
- PubMed: 21457777
- Original source →
- Free full text: PubMed Central →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
APA 7th
Ansari, M. A., & Scheff, S. W. (2011). NADPH-oxidase activation and cognition in Alzheimer disease progression. Free radical biology & medicine. https://doi.org/10.1016/j.freeradbiomed.2011.03.025
Vancouver
Ansari MA, Scheff SW. NADPH-oxidase activation and cognition in Alzheimer disease progression. Free radical biology & medicine. 2011. doi:10.1016/j.freeradbiomed.2011.03.025. PMID: 21457777.
BibTeX
@article{ansari2011-21457777,
author = {Ansari, M. A. and Scheff, S. W.},
title = {{NADPH-oxidase activation and cognition in Alzheimer disease progression}},
journal = {Free radical biology \& medicine},
year = {2011},
doi = {10.1016/j.freeradbiomed.2011.03.025},
pmid = {21457777},
url = {https://doi.org/10.1016/j.freeradbiomed.2011.03.025}
}
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