<i>Xenopus tropicalis</i> wound closure: promotion of re-epithelialisation and proliferation by TRH.

<p>(<b>A</b>) Representative images of the re-epithelialisation sheet in control, 10 nM and 10 µM TRH-treated punch wounds at day 7 in culture (scale bars: 0.5 mm). White-hatched lines indicate the leading edge of new epithelial sheets. (<b>B</b>) Representative images of PH3-positive cells in control, 10 nM and 10 µM TRH-treated punch wounds at day 7 in culture. The white-hatched line demarcates new epithelial tongue. (<b>C</b>) Representative images of TUNEL-positive cells in control, 10 nM and 10 µM TRH-treated punch wounds at day 7 in culture. The white-hatched line demarcates new epithelial tongue. Scale bars in (<b>B</b>) and (<b>C</b>) are 100 µm. (<b>D</b>) The graph shows the percentage reduction in wound-area of <i>X. tropicalis</i> punch wounds in control, 10 nM and 10 µM TRH-treated skin. (<b>E</b>) Percentage of proliferative (PH3-positive) cells present in the new epithelial tongue during re-epithelialisation. (<b>F</b>) Percentage of apoptotic (TUNEL-positive) cells present in the new epithelial tongue during re-epithelialisation. Data are mean ± SEM of 16 frogs (8 male and 8 female). Significance relative to control data at the same time-point denoted by *P<0.05, ***P<0.001.</p

Increased re-epithelialisation and proliferation in human skin following 17β-estradiol treatment.

<p>(<b>A</b>) Representative H&E stained sections of human skin punch-wounds following 6 days culture with either vehicle control, 100 nM or 1 µM 17β-estradiol (Est). New epithelial tongue indicated by red lines, scale bar represents 50 µm. (<b>B</b>) Representative images of Ki-67-TUNEL double-stained sections of human skin punch wounds following 6 days culture with either vehicle control, 100 nM or 1 µM 17β-estradiol. The white-hatched line demarcates new epithelial tongue. (<b>C</b>) The graph displays length measurements of the new epithelial tongue (as demarcated by the red lines in <b>A</b>) as analysed from H&E stained human skin sections following treatment with vehicle control, 100 nM and 1 µM 17β-estradiol. (<b>D</b>) Percentage of proliferative (Ki67-positive) cells in the new epithelial tongue of vehicle control, 100 nM and 1 µM 17β-estradiol-treated human skin wounds. (<b>E</b>) Percentage of apoptotic (TUNEL-positive) cells in the new epithelial tongue of vehicle control, 100 nM and 1 µM 17β estradiol-treated human skin wounds. Data are mean ± SEM of 4 female donors. Significance relative to control data denoted by *P<0.05, **P<0.01, ***P<0.001.</p

TRH stimulates re-epithelialisation and enhances proliferation in wounded human skin.

<p>(<b>A</b>) Representative H&E stained sections of human skin punch-wounds following 6 days culture with either vehicle control or 10 ng/mL TRH. New epithelial tongues indicated by the white-hatched lines. Scale bars represent 50 µm. (<b>B</b>) Representative images of Ki-67-TUNEL double-stained sections of human skin punch wounds following 6 days culture with either vehicle control or 10 ng/mL TRH. The white-hatched line demarcates new epithelial tongue. (<b>C</b>) The graph displays length measurements of the new epithelial tongue (as demarcated by the white-hatched lines in <b>A</b>) as analysed from H&E stained human skin sections following treatment with vehicle control, 5 ng/mL and 10 ng/mL TRH. (<b>D</b>) Percentage of proliferative (Ki67-positive) cells in the new epithelial tongue of vehicle control, 5 ng/mL and 10 ng/mL TRH-treated human skin wounds. (<b>E</b>) Percentage of apoptotic (TUNEL-positive) cells in the new epithelial tongue of vehicle control, 5 ng/mL and 10 ng/mL TRH-treated human skin wounds. Data are mean ± SEM of 4 female donors. Significance relative to control data at the same time-point denoted by *P<0.05, **P<0.01, ***P<0.001.</p

TRH increases cytokeratin 6 but not involucrin expression in human skin punch wounds.

<p>(<b>A</b>) Representative images indicated cytokeratin 6 (CK6) expression in control, 5 ng/mL and 10 ng/mL TRH-treated human skin punch wound sections, 6 Days post-wounding. The white-hatched line demarcates new epithelial tongue. (<b>B</b>) Representative images indicating involucrin (Inv) expression in control, 5 ng/mL and 10 ng/mL TRH-treated human skin punch wound sections, 6 Days post-wounding. The white-hatched line demarcates new epithelial tongue. (<b>C</b>) Quantification of involucrin immunoreactivity in the new epithelial tongues indicated in (A). (<b>D</b>) Quantification of CK6 immunoreactivity in the new epithelial tongues indicated in (B). Data are mean ± SEM of 4 female donors. Significance relative to control data at the same time-point denoted by **P<0.01, ***P<0.001.</p

<i>Xenopus tropicalis</i> mitosis: TRH increases epidermal mitosis.

<p>(<b>A–C</b>) Representative images of Weigert’s stained <i>X. tropicalis</i> epidermis with black arrows indicating mitotic cells. (<b>D</b>) The graph shows the percentage of mitotic figures identified by Weigert’s staining in the <i>X. tropicalis</i> epidermis. 200 nuclei were analysed per skin section, with 3 sections per animal counted. (<b>E</b>) The graph displays the total number of DAPI+ nuclei in the new epithelial tongues. Data are mean ± SEM of 4 frogs (2 male and 2 female). Significance relative to control data at the same time-point denoted by **P<0.01, ***P<0.001.</p

Frog serum and estrogen promote re-epithelialisation and proliferation in <i>Xenopus tropicalis</i> skin.

<p>(<b>A</b>) Representative images of re-epithelialisation sheet in control, 5% frog serum and 100 nM 17β-estradiol (Est)-treated punch wounds at day 7 in culture (scale bars: 0.5 mm). White-hatched lines indicate the leading edge of new epithelial sheets. (<b>B</b>) Representative images of PH3-positive cells in control, 5% frog serum and 100 nM 17β-estradiol-treated punch wounds at day 7 in culture. The white-hatched line demarcates new epithelial tongue. (<b>C</b>) Representative images of TUNEL-positive cells in control, 5% frog serum and 100 nM 17β-estradiol-treated punch wounds at day 7 in culture. The white-hatched line demarcates new epithelial tongue. Scale bars in (<b>B</b>) and (<b>C</b>) are 100 µm. (<b>D</b>) The graph shows the percentage reduction in wound-area of <i>Xenopus tropicalis</i> punch wounds in control, 5% frog serum (FS) and 100 nM 17β-estradiol-treated skin. (<b>E</b>) Percentage of proliferative (PH3-positive) cells present in the new epithelial tongue during re-epithelialisation. (<b>F</b>) Percentage of apoptotic (TUNEL-positive) cells present in the new epithelial tongue during re-epithelialisation. Data are mean ± SEM of 4–5 frogs (2 male and 3 female). Significance relative to control data at the same time-point denoted by *P<0.05, **P<0.01, ***P<0.001.</p