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Lipid changes within the epidermis of living skin equivalents observed across a time-course by MALDI-MS imaging and profiling.

Mitchell CA, Long H, Donaldson M, Francese S, Clench MR - Lipids Health Dis (2015)

Bottom Line: In particular development of an epidermal layer was observable as a compaction of the distribution of phosphatidylcholine species.MSI can be used to study changes in lipid composition in LSE.Determination of the changes in lipid distribution during the maturation of the LSE will assist in the identification of treatment responses in future investigations.

View Article: PubMed Central - PubMed

Affiliation: Biomedical Research Centre, Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK. c.mitchell@surrey.ac.uk.

ABSTRACT

Background: Mass spectrometry imaging (MSI) is a powerful tool for the study of intact tissue sections. Here, its application to the study of the distribution of lipids in sections of reconstructed living skin equivalents during their development and maturation is described.

Methods: Living skin equivalent (LSE) samples were obtained at 14 days development, re-suspended in maintenance medium and incubated for 24 h after delivery. The medium was then changed, the LSE re-incubated and samples taken at 4, 6 and 24 h time points. Mass spectra and mass spectral images were recorded from 12 μm sections of the LSE taken at each time point for comparison using matrix assisted laser desorption ionisation mass spectrometry.

Results: A large number of lipid species were identified in the LSE via accurate mass-measurement MS and MSMS experiments carried out directly on the tissue sections. MS images acquired at a spatial resolution of 50 μm × 50 μm showed the distribution of identified lipids within the developing LSE and changes in their distribution with time. In particular development of an epidermal layer was observable as a compaction of the distribution of phosphatidylcholine species.

Conclusions: MSI can be used to study changes in lipid composition in LSE. Determination of the changes in lipid distribution during the maturation of the LSE will assist in the identification of treatment responses in future investigations.

No MeSH data available.


Principal component analysis of MALDI-MS spectra acquired from LSE. Score plots were generated showing groupings and variability between the 4, 6 and 24 h group spectra from the a) epidermis or c) dermis regions of the skin. The loading plots show a distribution of m/z spectra ion species which are contributors of grouping and variability in the b) epidermis or d) dermis between the time-course groups; the quadrant space in corresponding between the plots
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Fig2: Principal component analysis of MALDI-MS spectra acquired from LSE. Score plots were generated showing groupings and variability between the 4, 6 and 24 h group spectra from the a) epidermis or c) dermis regions of the skin. The loading plots show a distribution of m/z spectra ion species which are contributors of grouping and variability in the b) epidermis or d) dermis between the time-course groups; the quadrant space in corresponding between the plots

Mentions: Principle component analysis (PCA) scores and loadings plots were performed to identify changes that occurred in the LSE samples during the time course study. Figure 2 shows the PCA plots obtained from the analysis of the spectra taken from the epidermis alone: Fig. 2a, c shows the scores plot giving the extent of groupings and variability between the skin spectra at different time points. Figure 2b and d shows the loadings plot comprising of the spatial distribution of m/z spectral species in correspondence to the scores plot positions. Figure 2a and b show the corresponding scores and loadings plots for observable changes in epidermal regions; Fig. 2c, d for the dermis. The epidermis PCA scores plot (Fig. 2a) show an overall trend which is that; the 24 h group is more separated in the PCA space than the 4 and 6 h spectra groups. For the scores plots for in the dermal region however (Fig. 2c), the spectra seemed to associate more with each other as the time-course progressed; the 4 h group being the most distinct. In the loadings plot obtained from the epidermis data (Fig. 2b) it can be seen that m/z 759, 757 and 732 are major contributors to the observed variance. Examination of the dermis PCA loadings plot (Fig. 2d), suggests that m/z 760, 758, 732 and 734 appeared to distinguish the 4 h group within the lower right quadrants of the loadings plot.Fig. 2


Lipid changes within the epidermis of living skin equivalents observed across a time-course by MALDI-MS imaging and profiling.

Mitchell CA, Long H, Donaldson M, Francese S, Clench MR - Lipids Health Dis (2015)

Principal component analysis of MALDI-MS spectra acquired from LSE. Score plots were generated showing groupings and variability between the 4, 6 and 24 h group spectra from the a) epidermis or c) dermis regions of the skin. The loading plots show a distribution of m/z spectra ion species which are contributors of grouping and variability in the b) epidermis or d) dermis between the time-course groups; the quadrant space in corresponding between the plots
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4525729&req=5

Fig2: Principal component analysis of MALDI-MS spectra acquired from LSE. Score plots were generated showing groupings and variability between the 4, 6 and 24 h group spectra from the a) epidermis or c) dermis regions of the skin. The loading plots show a distribution of m/z spectra ion species which are contributors of grouping and variability in the b) epidermis or d) dermis between the time-course groups; the quadrant space in corresponding between the plots
Mentions: Principle component analysis (PCA) scores and loadings plots were performed to identify changes that occurred in the LSE samples during the time course study. Figure 2 shows the PCA plots obtained from the analysis of the spectra taken from the epidermis alone: Fig. 2a, c shows the scores plot giving the extent of groupings and variability between the skin spectra at different time points. Figure 2b and d shows the loadings plot comprising of the spatial distribution of m/z spectral species in correspondence to the scores plot positions. Figure 2a and b show the corresponding scores and loadings plots for observable changes in epidermal regions; Fig. 2c, d for the dermis. The epidermis PCA scores plot (Fig. 2a) show an overall trend which is that; the 24 h group is more separated in the PCA space than the 4 and 6 h spectra groups. For the scores plots for in the dermal region however (Fig. 2c), the spectra seemed to associate more with each other as the time-course progressed; the 4 h group being the most distinct. In the loadings plot obtained from the epidermis data (Fig. 2b) it can be seen that m/z 759, 757 and 732 are major contributors to the observed variance. Examination of the dermis PCA loadings plot (Fig. 2d), suggests that m/z 760, 758, 732 and 734 appeared to distinguish the 4 h group within the lower right quadrants of the loadings plot.Fig. 2

Bottom Line: In particular development of an epidermal layer was observable as a compaction of the distribution of phosphatidylcholine species.MSI can be used to study changes in lipid composition in LSE.Determination of the changes in lipid distribution during the maturation of the LSE will assist in the identification of treatment responses in future investigations.

View Article: PubMed Central - PubMed

Affiliation: Biomedical Research Centre, Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK. c.mitchell@surrey.ac.uk.

ABSTRACT

Background: Mass spectrometry imaging (MSI) is a powerful tool for the study of intact tissue sections. Here, its application to the study of the distribution of lipids in sections of reconstructed living skin equivalents during their development and maturation is described.

Methods: Living skin equivalent (LSE) samples were obtained at 14 days development, re-suspended in maintenance medium and incubated for 24 h after delivery. The medium was then changed, the LSE re-incubated and samples taken at 4, 6 and 24 h time points. Mass spectra and mass spectral images were recorded from 12 μm sections of the LSE taken at each time point for comparison using matrix assisted laser desorption ionisation mass spectrometry.

Results: A large number of lipid species were identified in the LSE via accurate mass-measurement MS and MSMS experiments carried out directly on the tissue sections. MS images acquired at a spatial resolution of 50 μm × 50 μm showed the distribution of identified lipids within the developing LSE and changes in their distribution with time. In particular development of an epidermal layer was observable as a compaction of the distribution of phosphatidylcholine species.

Conclusions: MSI can be used to study changes in lipid composition in LSE. Determination of the changes in lipid distribution during the maturation of the LSE will assist in the identification of treatment responses in future investigations.

No MeSH data available.