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Table 1 Summary of image data quality

From: Spatially transformed fluorescence image data for ERK-MAPK and selected proteins within human epidermis

Target

Quality

Notes

Raf-1 (total)

Raf-1 also known as c-Raf. Cytoplasmic and nuclear signal across all three patients. Some patient-specific differences, with Pat2 in particular showing a stronger signal within the basal layer. Pat3 image data contains two dermal protrusions. Nuclear localisation within the suprabasal keratinocytes was unexpected.

Raf-1 (pS338)

Raf-1 also known as c-Raf. Moderate cytoplasmic signal intensity with some nuclear signal, and good cellular morphology for Pat1 and Pat2. Tissue sample for Pat3 shows some evidence of degradation or dehydration from storage; however, the fluorescence signal data show quantitative agreement with those from Pat1 and Pat2.

MEK1/MEK2 (total)

MEK1/2 also known as MAPKK1/2. Primarily cytoplasmic localisation with some nuclear signal and non-specific signal within fully differentiated corneocytes. Potential epitope masking with phosphorylated MEK1/2, as cytoplasmic MEK1/2 tends to decrease over the spinous and granular layers where the levels of phospho-MEK1/2 show a strong increase (Additional file 4). Pat1 tissue at a slight angle to the imaging plane.

MEK1/MEK2 (pS218/pS222)

MEK1/2 also known as MAPKK1/2. Very good fluorescence signal intensity with predominantly cytoplasmic nuclear localisation across all three patients. Pat1 tissue is at a slight angle relative to the imaging plane. Tissue thicknesses quite different across patients (tissue from Pat2 very thick, from Pat3 very thin).

ERK1/ERK2 (total)

ERK1/2 also known as MAPK3/1. Pat2 shows the best signal intensity and cellular morphology. Although the signal intensity for Pat1 and Pat3 are not much greater than the signal-to-noise-ratio, the mean-normalised LOESS-smoothed data show good agreement.

ERK1/ERK2 (pT183/pY185)

ERK1/2 also known as MAPK3/1. Pat1 shows the best signal intensity and cellular morphology.

NB: Pat2 data were collected using Alexa-555, not Alexa-488 as with the remaining data (which led to changes in captured spectra), as problems were encountered with the data collected during the Alexa-488 labelling experiment for this patient.

Calmodulin

Very good fluorescence signal intensity, with strong signals in the plasma membrane of basal cells and the nucleus of suprabasal cells. Differences in patient skin thickness very pronounced (tissue from Pat2 very thick, from Pat3 very thin).

β1 integrin

β1 integrin also known as CD29. Very strong plasma membrane signal intensity within the basal keratinocytes of all three patients, predominantly localised to the apicolateral cell surface. A moderate signal intensity was often observed for suprabasal keratinocytes within the lower tissue layers. Pat3 tissue at a slight angle relative to the imaging plane.

β4 integrin

Unexpected cytoplasmic signal intensity across most of the epidermis (potentially non-specific). The signal intensity is strongest in the basal membrane of basal keratinocytes (where hemidesmosomes are localised). The cytoplasmic signal, at least within basal keratinocytes, might be attributed to endocytosis of the underlying basal lamina.

Stratifin

Stratifin also known as 14-3-3σ. Very strong cytoplasmic signal intensity across the epidermis of all three patients. Pat1 tissue is at a slight angle to the imaging plane.

c-Jun

Pat1 tissue shows moderate signal intensity and morphology, but the centre of the epidermis is not properly aligned with the imaging plane. Some patient-specific differences are noticeable, with nuclear signal intensity stronger in Pat2. Cells with strong nuclear c-Jun signal are primarily located within the basal layer in all three patients.

Jun-B

Fairly good signal intensity and cellular morphology across all three patients, with signals from the cytoplasm and nucleus.

c-Fos

Pat1 tissue has an unusual morphology, with the dermis extending up into the epidermis within this data stack. There are some differences between patients: c-Fos is primarily localised to the nucleus with a moderate signal intensity for Pat2; whereas Pat1 and Pat3 show a moderate cytoplasmic signal (providing better cellular morphology) and a very strong nuclear signal intensity.

Fra2

The data show a particularly punctate pattern within the nucleus and a more diffuse cytoplasmic signal. For Pat1, the tissue seems to be at an angle relative to the image plane; Pat2 and Pat3 data have better signal intensity and cellular morphology.

K10

Good cytoplasmic signal intensity within suprabasal cells of all three patients. For Pat1 and Pat2 the tissue is slightly out of the imaging plane.

K14

Strong cytoplasmic signal intensity within basal keratinocytes of all three patients. The intracellular and intercellular variations in signal intensity were unexpected for an intermediate filament protein. Some expression was observed in early suprabasal cells. Pat2 tissue contains a dermal protrusion into the epidermis.

  1. The immunofluorescence targets are listed, with a qualitative score of image data quality and brief notes on the staining. Additional file 3 contains further information on these targets and the antibodies used for immunofluorescence labelling. Additional file 4 contains a more detailed comparison of these data with those from previous studies of epidermal biology. Pat, patient