Table 1 Review of reported effects on the barrier function, such as proliferation, differentiation, and PM penetration in varying skin models upon exposure to PM
Model | PM type | Dose and application | Exposure time | Main findings | Ref. |
|---|---|---|---|---|---|
Ex vivo human skin | SRM® 1649b | 2 mg/cm2, topical | 24 h | - Pyknotic nuclei. - Decreased collagen-1 protein expression. | [119] |
Pig | SRM® 1648a and 1649b | 100 μg/m2, topical | 5 d | - Decreased E-cadherin, cytokeratin, and filaggrin protein expression. | [120] |
Mice, BALB/c with disrupted barrier | PM ≤1 μm from Seoul, Korea | 8 μg/cm2, topical | 6 h and 2 w repetitive exposures, 10 times total | - Healthy barrier: PM remained in follicles. - Disrupted barrier: penetration of PM in SS. - Repeated exposure: dermal penetration of PM. | [121] |
Mice, BALB/c | SRM® 1649b | 100 μg/m2, topical | 24 h repetitive exposures, 5 d total | - Decreased filaggrin protein expression. | [122] |
Mice, HR-1 | SRM® 1650b | 100 μg/mL, topical | 7 d | - PM internalization. | [123] |
SRM® 1650b | 100 μg/mL, topical | 7 d | - Increased keratin 10 and PCNA protein expression. | [124] | |
HSE | SRM® 2975 | 200 μg/mL, systemic | 2 d repetitive exposures, 6 d total | - Decreased keratin 16, keratin 17, and Ki67 protein expression. | [125] |
ERM-CZ120 | 200 μg/mL, systemic | 48 h | - Altered morphology of epidermis. | [126] | |
HEE | Diesel PM or vapor | 0.05% (v/v), systemic | 20 d | - Decreased protein expression of cornifin A, suprabasin, and antileukoproteinase. | [127] |
CAPs, PM2.5 | 0.5 and 2.0 μg/cm2, topical | 24 and 48 h | - PM penetration in SC after 24 h. - PM penetration in deeper layers after 48 h. - No alterations in morphology. | [128] | |
CRM no. 28 | 25 mg, topical | 6 h | - Claudin 4 gene expression is upregulated. - No changes in mRNA expression of filaggrin, loricrin, involucrin, transglutaminase 1, keratin 1, keratin 10, keratin 5, and keratin 14. | [129] | |
SRM® 1648a | 200 ppm, systemic | 96 h | - Altered morphology. - Decreased PCNA and filaggrin protein expression. | [130] | |
SRM® 1648a | 2.2, 8.9, and 17.9 μg/cm2, topical | 24 and 48 h | - Decreased cytokeratin 10, involucrin, and loricrin protein expression. - Increased barrier permeability for 17.9 μg/cm2. - Increased protein expression of aquaporin 3. | [131] | |
PM2.5 from Seoul, Korea | 50 μg/mL, topical | 24 h | - Decreased keratin-10, claudin-1, desmocollin-1, and IFN-γ protein expression. - Increased S100A7 and S100A8 protein expression. | [132] | |
PM0.3–2.5 from Benin, West-Africa | 30 μg/cm2, topical | 24 h | - Decreased loricrin protein expression. | [133] | |
PM2.5 from Xi’an, China | 50 μg/mL, systemic | 24 h repetitive exposures, 2, 4, or 6 d total | - Increased cholesterol levels. - Reduced squalene levels. | [134] | |
NHDF | SRM®2787 | 30 μg/cm2, systemic | 24 h | - PM internalization into autolysosomes. | [135] |
ERM-CZ100 | 200 μg/mL, systemic | 24 h | - Increased elastase and collagenase activity. - Increased procollagen protein expression. | [136] | |
The pre-conditioned medium of HaCaT treated with CRM no. 28 | 125 μg/mL, systemic | 30 m, 48 h post-incubation | - Increased elastase and collagenase activity. | [137] | |
NHEK | PM2.5 from Xi’an, China | 50 μg/mL, systemic | 24 h | - Top upregulated genes of transcriptomics analysis are S100A8, S100A9, keratin 6B, keratin 19, serpin B3, and mostly the genes are involved in cholesterol metabolism. | [134] |
Diesel PM or vapor | 0.05% (v/v), systemic | 20 d | - Decreased envoplakin, suprabasin, filaggrin, involucrin, sciellin, caspase-14, cornifin-A protein, keratin-1, and keratin-10 protein expression. | [127] | |
Diesel PM | 30 and 60 μg/mL, systemic | 24 h | - PM internalization. | [138] | |
Asian dust storm particles from Seoul, Korea | 25 μg/mL, systemic | 24 h | - Increased caspase 14 and ITGA6 mRNA expression. | [139] | |
PM ≤1 μm from Seoul, Korea | 40 μg/cm2, systemic | 24 h | - PM internalization. | [121] | |
PM2.5 from Seoul, Korea | 50 μg/mL, systemic | 2 or 4 d | - Decreased number and length of cilia. - Increased SPRR3 protein expression. - Decreased keratin 1, keratin 10, and IFT88 mRNA expression. | [140] | |
SRM®2786 | 1 mg/mL, systemic | 6 h | - RNA-Seq analysis: Upregulation of keratin-associated protein 2–3, keratin 13, keratin 34, and claudin 4. Downregulation of growth differentiation factor 15. | [141] | |
PM2.5 from Seoul, Korea | 25 μg/mL, systemic | 24 h | - Top upregulated genes from transcriptomics analysis are SPRR family members and other cornified envelope-related genes, transglutaminase 3, involucrin, filaggrin, keratin 10, keratin 15, S100A7, S100A8, S100A9, and S10012. | [132] | |
HaCaT | CRM no. 28 | 125 μg/mL, systemic | 30 m, 24 h post-incubation | - Increased elastase and collagenase activity. | [137] |
SRM® 1649b | 50 μg/cm2, systemic | 24 h | - Decreased aquaporin-3 protein expression. | [142] | |
SRM® 1649b | 50 μg/cm2, systemic | 24 h | - Decreased filaggrin, repetin, involucrin, and loricrin protein expression after 24 h. | [143] | |
PM2.5 from Shanghai, China | 10–100 μg/mL, systemic | 24 h | - Increased involucrin, repetin, and filaggrin (highest dose) protein expression. - No changes in loricrin protein expression. | [144] | |
SRM® 1649b | 25 and 50 μg/cm2, systemic | 4 and 24 h | - Decreased filaggrin protein expression. | [122] | |
SRM® 1650b | 50 μg/mL, systemic | 1, 4, 8, 12, and 24 h | - PM internalization. | [123] | |
SRM® 2975 | 100 and 200 μg/mL, systemic | 24 h | - No changes in loricrin protein expression. - Increased involucrin protein expression. - Decreased keratin 16, keratin 17, and Ki67 protein expression. - Decreased BrdU incorporation. | [125] | |
CAPs, PM2.5 | 5–25 μg/mL, systemic | 1, 3, 6, and 24 h | - PM internalization. | [145] |