Table 4.
Post-traumatic inflammatory consequences on aged animals. Abbreviations: ↑: increase; ↓: decrease; CCI: controlled cortical impact; CD: cluster of differentiation; CX3CL1: chemokine (C-X3-C motif) ligand 1; d: days post-injury; h: hours post-injury; IFNγ: interferon γ; IL: interleukin; iNOS: inducible nitric oxide synthase; LFP: lateral fluid percussion; M: post-natal months; MCP-1: monocyte chemoattractant protein-1; NC: not compared; TBI: traumatic brain injury; TGFβ: transforming growth factor β; TNFα: tumor necrosis factor α; W: post-natal weeks; YA: young adult.
| Animal and TBI Model | Age (Aged) |
Compa-rison Age (YA) |
Main Highlights | Reference | ||
|---|---|---|---|---|---|---|
| Microglia | Astrocytes | Cytokines and Other Immune Cells | ||||
|
Mice
LFP, open skull, unilateral |
M12 | M1.5/3 | - activation aged >> YA at 7 and 28 d | - activation aged >> YA at 7 and 28 d | [199] | |
|
Mice
CCI, open skull, unilateral |
M18 | M3 | - number aged < YA at baseline and 3 d - ↑ aged > YA at 3 d - ↓ phagocytic capacities in aged at 3 d |
- TNFα, and IL-1β expression aged > YA at 3 d - ↑ immune cells infiltration at 3 d |
[200] | |
|
Mice
CCI, open skull, unilateral |
M18 | M4 | - activation in aged from 1 to 7 d (hippocampus and cortex) - Activation in YA from 1 to 3 d - Gene expression of reactive astrocytes, inflammatory response, complement pathway, and synaptic support are modified in aged - Loss of astrocytes function and astrogliopathy in aged - No clear dichotomy A1/A2 in aged |
[201] | ||
|
Mice
CCI, open skull, unilateral |
M19 | NC | - ↑ at 7 and 30 d (hippocampus) - ↑ at 10 and 30 d (total brain) - ↑ phagocytic activity at 30 but not 10 d |
[202] | ||
|
Mice
CCI, open skull, unilateral |
M20/25 | M3/6 | - ↑ pro-inflammatory markers (IL-1β, TNFα, and iNOS) in aged at 7 d - ↓ anti-inflammatory markers (Ym1, CD206, TGFβ, and IL-4Ra) in aged at 7 d - chemotactic ligands expression aged > YA at 4 and 7 d - monocyte infiltration aged > YA at 4 and 7 d |
[203] | ||
|
Mice
CCI, open skull, unilateral |
M21 | M2 | - IL-1β, TNFα and IL-6 expression aged > YA at baseline - IL-1β expression in aged > YA at 3 d |
[204] | ||
|
Mice
CCI, open skull, unilateral |
M21 | M2 | - M2a phenotype aged > YA at 1 d - M2a phenotype aged < YA at 5 d |
- inflammatory markers expression aged ≠ YA at 1 and 5 d | [205] | |
|
Mice
CCI, open skull, unilateral |
M21/24 | M5/6 | - number aged > YA at baseline and from 1 to 28 d (hippocampus) | - number aged > YA at baseline and from 1 to 28 d (hippocampus) | [206] | |
|
Mice
CCI, open skull, unilateral |
M21/24 | NC | - ↑ at 30 and 60 d (thalamus) | [207] | ||
|
Mice
LFP, open skull, unilateral |
M22/25 | M5/6 | - cytokine expression profile aged ≠ YA | [208] | ||
|
Mice
CCI, open skull, unilateral |
M23 | M3 | - activation aged > YA at 1 d | - Anti-inflammatory chemokine CX3CL1 ↓ in aged at 1 d - recruitment and activation of peripheral immune cells aged > YA at 1 d |
[209] | |
|
Mice
CCI, open skull, unilateral |
M24 | M3 | - activation aged > YA at 7 d (cortex and hippocampus) - M1 phenotype genes expression levels aged > YA at 1 d (cortex) - variation in M2a phenotype genes expression at 1 d (cortex) - M2c phenotype genes expression aged < YA at 1 d (cortex) |
[210] | ||
|
Rats
LFP, open skull, unilateral |
M12 | W10 | - number of leukocytes, myeloid cells and microglia aged < YA (ipsilateral hemisphere) | [211] | ||
|
Rats
Penetrating TBI, open skull, unilateral |
M20/22 | M5/12 | - number aged < YA at 2 d | - number aged > YA at 2 d | [212] | |