Table 6.
Summary of changes in stratum corneum (SC) organization and SC lipid composition observed in atopic dermatitis (AD), Netherton syndrome (NTS) and psoriasis compared with control. In addition, synthetic lipid systems are provided, in which changes in lipid composition (similar to those observed in AD, NTS and psoriasis) are related to change in lipid organization that could possibly modulate the lipid barrier. No systems are included that result in clear phase separation other than phase separated CHOL. For abbreviations CER subclasses, see Figure 2 and page 2.
| Skin diseases: organization and lipid composition changes relative to control | |||
|---|---|---|---|
| Disease | Organization changes | Changes in composition | Ref. |
| AD | a. Changes in lamellar phasesa b. Orthorhombic packing↓ c. Conformational disordering chains↑ |
FFA chain length:b↓ FFA unsaturation:↑ CER chain length:c ↓ CER-C34:d↑ CER AS↑, NSe, AHe↑ CER NP, NdS, NH, AH, EOS, EOH, EOP↓ |
[49, 101–109, 113, 119] |
| NTS | a. Dramatic changes in lamellar phases b. Conformational disordering↑ |
FFA chain length:f
FFA unsaturation: ↑ 3% to 28.7% CER chain length ↓ CER-C34: ↑ 8.5 to 27.2% CER subclasses: CER NS/AS ↑ EOS, EOP, EOdS, EOH, NP↓ |
[154, 155] |
| Psoriasis | a. Changes in lamellar phases | CER chain length↓ CER NS↑ CER EOS, NP, AH↓ |
[18, 135] |
| Model systems with synthetic CER compositions | |||
| Model with lamellar phases | Change in organization, ordering and/or flux | Change in composition | |
| SPP**** porcine CER or NS model | Short chain FFA increase conformational ordering Ethyl-PABA*flux: 7x↑ |
FFA C24 to FFAmix:g
FFA chain length ↓ |
[246] |
| SPP**** CER NS model | TH flux**: 3x↑ IND flux***: 3.8x↑ TEWL: 2.3x↑ |
FFA C24 to FFAmix:g
FFA chain length ↓ |
[243] |
| LPP/SPP**** human model | Orthorhombic packing ↓ Ethyl-PABA flux*: 2.4x↑ TEWL: 2.8x↑ |
FFA chain length: h↓ | [220] |
| LPP/SPP**** porcine model | Orthorhombic packing↓ Conformational ordering: ↓ LPP and SPP not affected Hydrocortisone flux: 3x↑ TEWL: 4.5x ↑ |
FFA MUFA:j↑ |
[219] |
| LPP/SPP**** porcine model | Orthorhombic packing↓ Conformational ordering↓ Hydrocortison flux:13x↑ |
Synth porcine CER uniform chain length to isolated porcine CERs | [44] |
| LPP/SPP**** human model | No changes in LPP, SPP and lateral packing, Conformational disordering CER NS C34: ↑ Ethyl-PABA*: flux 1.4↑ |
CER NS-C34+CER AS-C34↑:k 0 to 13% | [112] |
| LPP****: NS/NP model |
No change in lipid organization; TEWL↑ |
CER NS/NP ratio varied from 1: 2 to 2:1 | [274] |
| LPP/SPP**** porcine model | LPP ↓ Ethyl-PABA* flux: 1.9x ↑ |
CER EO: 15% to 0% | [211] |
| LPP/SPP**** human model |
LPP↓ TH flux**: no change IND flux***: around 2x↑ TEWL: no change |
CER EOmixl: 30% to 0% CER EOdS, EOS, EOP also reported: 30% to 0 |
[206] |
| SPP**** NS model |
LPP not formed Orthorhombic packing: ↑ TH flux**: 3x↓ IND flux***:2.5↓ TEWL: no change |
CER EOmixl: from 10% to 0% | [217] |
| LPP/SPP**** human model |
LPP↓ Orthorhombic packing:↓ TH flux**: no change IND flux***: 2x↑ TEWL: ↑trend |
CER EOmixl: 10% to 0% CER EOS, EOP and EOdS also reported |
[217] |
| SPP**** NS model |
Slight phase separation NdS system TH flux**: no change IND flux***: no change |
CER NS replaced by CER NdS | [247] |
| SPP**** porcine CER model |
No changes lipid organization Ethyl-PABA flux*: no change |
Porcine CERs replaced by CER NS | [246] |
| LPP**** NS model |
No changes in lipid organization Ethyl-PABA flux*: no change |
CER NS replaced by CER AS | [222] |
Ethyl-PABA=ethyl-para-amino benzoic acid;
TH= theophylline;
IND=indomethacin
LPP= long periodicity phase, SPP= short periodicity phase
= reduction in LPP repeat distance and reduction in shoulder of the complex peak. This shoulder is attributed to the LPP.
= Average chain length of FFA reduced from 21.4 to 18.2 carbon atoms [109].
= Average chain length of CERs reduced from 47.0 to 44.3 total carbon atoms [109].
= CER NS-C34 increased from 3 to 11.4 m/m% [119]; 7 to 16 m/m%. [147]; 1 to 7 m/m% [49].
= Some papers report AH↑, NS↑, others not.
= Average chain length of FFA reduced: from 24.5 to 23.4 (C16/C18 not included) carbon atoms [154].
= Average chain length of FFA reduced from 24 to 22.4 carbon atoms.
= Average chain length of FFA reduced from 22.4 to 20.0 carbon atoms.
= Saturated FFA C22 (42.6%) or FFA C24 (34.7%) replaced by its unsaturated counterpart.
= CER NS-C34 and CER AS-C34 have a acyl chain of 16 carbon atoms, spingoid base is 18 carbon atoms
= EOmix is composed of CER EOS, CER EOP and CER EOdS (approximately 78, 16,4 and 5.6 w/w%, respectively).