Table 2.
Brain ECM stiffness in Alzheimer’s disease subjects in comparison with healthy condition
| Method | Stiffness in AD | Samples (healthy vs. AD subjects) | μ | REF |
|---|---|---|---|---|
| MRE | ↓ | 8 wild-type mice (17.5–23-month-old) and 5 transgenic APP-PS1 (AD) mice (20.5-month-old) |
◾ Wild-type mice: 25.0 ± 6.4 kPa ◾ AD mice: 19.3 ± 3.3 kPa % difference: -22.80% (p = 0.0031) |
[42] |
| MRE | ↓ | 39 wild-type mice (6-week-old) and 45 transgenic APP23 (AD) mice (6-week-old) |
Hippocampal region: ◾ Controls mice: 7.75 ± 0.3 kPa ◾ APP23 mice: 7.01 ± 0.52 kPa % difference: -9.55% |
[43] |
| MRE | ↓ |
28 human patients: ◾ 7 with probable AD ◾ 14 PIB-negative cognitively normal controls (CN-) ◾ 7 PIB-positive cognitively normal controls (CN +) |
◾ CN- group: 2.37 kPa ◾ CN + group: 2.32 kPa ◾ AD group: 2.20 kPa (p = 0.0055) % difference: -7.17% (AD and CN-) and -5.17% (AD and CN +) |
[44] |
| MRE | ↓ |
48 human patients: ◾ 16 amyloid-negative cognitively normal controls (CN-) ◾ 16 amyloid-positive cognitively normal controls (CN +) ◾ 8 amyloid-positive subjects with mild cognitive impairment ◾ 8 amyloid-positive subjects with probable AD |
◾ CN group: 2.51 ± 0.09 kPa ◾ AD group: 2.40 ± 0.09 kPa % difference: -4.38% |
[45] |
| MRE | ↓ |
84 human patients: ◾ 20 normal pressure hydrocephalus patients (60–86 years old) ◾ 8 AD patients (78–87 years old) ◾ dementia with Lewy bodies patients (63–76 years old) ◾ frontotemporal dementia patients (54–65 years old) ◾ 46 cognitively normal controls (56–89 years old) |
A mean of -0.009 ± 0.001 kPa/year | [46] |
| MRE | ↓ |
23 human patients: 11 AD patients (mean age: 76.8) and 12 healthy controls (mean age: 69.4) |
Cerebrum: ◾ healthy controls: 2.50 ± 0.05 kPa ◾ AD patients: 2.25 ± 0.05 kPa % difference: -10% (p = 0.004) |
[47] |
| MRE | ↓ |
42 human patients: 21 AD patients and 21 healthy controls (mean age 75 years) |
Hippocampus: ■ healthy controls: 1.076 ± 0.190 kPa ■ AD patients: 0.863 ± 0.147 kPa % difference: -19.80% (p < 0.001) |
[48] |
| Indentation | ↓ |
Post-mortem brain tissue from frontal lobes of 10 subjects: ◾ 5 AD patients ◾ 5 normal controls |
-23.5% (gray matter) and -27.9% (white matter) (p < 0.0001) | [49] |
| AFM | ↓ | 16 transgenic B6C3-Tg (AD) mice and 27 wild-type littermates |
◾ Wild-type littermates: 0.651 ± 0.138 kPa ◾ AD mice: 0.402 ± 0.097 kPa % difference: -38.25% |
[50] |
ECM data comparison between healthy and pathological human or animal samples with a similar range of age. The applied method (MRE, AFM or indentation), ECM stiffness variation (↑ for an increase and ↓ for a decrement), analyzed samples, shear elasticity (μ) variations, year of the experiment conduction and the article reference are reported. Shear elasticity (μ) is a measure of the elastic shear stiffness of a material. PIB stands for “Pittsburgh Compound B”