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Ephrin-Bs Drive Junctional Downregulation and Actin Stress Fiber Disassembly to Enable Wound Re-epithelialization.

Nunan R, Campbell J, Mori R, Pitulescu ME, Jiang WG, Harding KG, Adams RH, Nobes CD, Martin P - Cell Rep (2015)

Bottom Line: Much is known about how lead-edge cells migrate, but very little is known about the mechanisms that enable active participation by cells further back.Here we show that ephrin-B1 and its receptor EphB2 are both upregulated in vivo, just for the duration of repair, in the first 70 or so rows of epidermal cells, and this signal leads to downregulation of the molecular components of adherens and tight (but not desmosomal) junctions, leading to loosening between neighbors and enabling shuffle room among epidermal cells.If this signaling axis is perturbed, then disrupted healing is a consequence in mouse and man.

View Article: PubMed Central - PubMed

Affiliation: Schools of Biochemistry and Physiology & Pharmacology, University of Bristol, Bristol BS8 1TD, UK.

No MeSH data available.


Related in: MedlinePlus

Overexpression of Ephrin-B1 Leads to Cell-Cell Adhesion Breakdown and May Contribute to Impaired Healing in Chronic Wounds(A) Schematic represents location, size, and timing of biopsy wound made in healthy human volunteers.(B) H&E staining of a day 3 human acute wound. Advancing epidermal margins are indicated by yellow arrowheads.(C) Human acute wounds were immunostained for ephrin-B1 as revealed by DAB (brown) and dual immunofluorescent staining of ephrin-B1 and E-cadherin (green and red).(D) Individual cell transfected with ephrin-B1:GFP plasmid (green) within a confluent monolayer of HaCaTs. Yellow arrowhead indicates intercellular loosening.(E) Immunostaining of ephrin-B1:GFP cells for E-cadherin. White and yellow arrowheads indicate present or absent E-cadherin staining, respectively, at the interface between transfected cell and all neighbors.(F) Ephrin-B1-transfected cells just behind the wound edge at 15 hr post-scratching. The fixed wound is stained for ephrin-B1 (green) and actin (red). Asterisk indicates intercellular space.(G) Schematic illustrates the location and size of biopsies taken from the margin of patients’ venous leg ulcers.(H) Typical healing (n = 6 patients) and non-healing (n = 6 patients) chronic-wound biopsies immunostained for ephrin-B1 to reveal intensity of ephrhin-B1 staining (low magnification) and degree of cell detachment (high magnification). Asterisks indicate the large intercellular spaces.Scale bars, 400 μm (B), 100 μm (C, left), 25 μm (C, middle), 10 μm (C, right), 20 μm (D), 20 μm (E), 20 μm (F), 250 μm (H, low magnification), and 25 μm (H, high magnification).
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fig7: Overexpression of Ephrin-B1 Leads to Cell-Cell Adhesion Breakdown and May Contribute to Impaired Healing in Chronic Wounds(A) Schematic represents location, size, and timing of biopsy wound made in healthy human volunteers.(B) H&E staining of a day 3 human acute wound. Advancing epidermal margins are indicated by yellow arrowheads.(C) Human acute wounds were immunostained for ephrin-B1 as revealed by DAB (brown) and dual immunofluorescent staining of ephrin-B1 and E-cadherin (green and red).(D) Individual cell transfected with ephrin-B1:GFP plasmid (green) within a confluent monolayer of HaCaTs. Yellow arrowhead indicates intercellular loosening.(E) Immunostaining of ephrin-B1:GFP cells for E-cadherin. White and yellow arrowheads indicate present or absent E-cadherin staining, respectively, at the interface between transfected cell and all neighbors.(F) Ephrin-B1-transfected cells just behind the wound edge at 15 hr post-scratching. The fixed wound is stained for ephrin-B1 (green) and actin (red). Asterisk indicates intercellular space.(G) Schematic illustrates the location and size of biopsies taken from the margin of patients’ venous leg ulcers.(H) Typical healing (n = 6 patients) and non-healing (n = 6 patients) chronic-wound biopsies immunostained for ephrin-B1 to reveal intensity of ephrhin-B1 staining (low magnification) and degree of cell detachment (high magnification). Asterisks indicate the large intercellular spaces.Scale bars, 400 μm (B), 100 μm (C, left), 25 μm (C, middle), 10 μm (C, right), 20 μm (D), 20 μm (E), 20 μm (F), 250 μm (H, low magnification), and 25 μm (H, high magnification).

Mentions: Since ephrin KD had such a dramatic effect on murine wound closure, leading to failure of wound re-epithelialization, we wondered whether defects in Eph-ephrin signaling might be in part causal of defective healing in human patients. Day 3 punch biopsy wounds made on the upper arm skin of normal healthy volunteers (Figures 7A–7C; Figures S7A and S7B) exhibited, as in mouse, epidermal migration that contributed to repair of the wound (Figure 7B). Immunostaining of these wounds revealed a rather similar distribution of ephrin-B1 staining to that of healing murine wounds (Figure 7C), except that expression extended back farther (i.e., 100+ cells back from the wound edge). As in healing mouse wounds, E-cadherin immunostaining appeared largely excluded from the basal layers of epidermis in which ephrin-B1 was expressed (Figure 7C), and resin histology revealed intercellular spaces in the migrating epidermal front (Figure S7B). As a first attempt to investigate a clinical link between Eph-ephrin signaling and wound repair, we undertook a qPCR analysis of ephrin-B1 and associated gene transcripts in human chronic wounds. Venous leg ulcers were stratified according to whether they subsequently healed (n = 20) or not (n = 51) within 3 months after initial referral.


Ephrin-Bs Drive Junctional Downregulation and Actin Stress Fiber Disassembly to Enable Wound Re-epithelialization.

Nunan R, Campbell J, Mori R, Pitulescu ME, Jiang WG, Harding KG, Adams RH, Nobes CD, Martin P - Cell Rep (2015)

Overexpression of Ephrin-B1 Leads to Cell-Cell Adhesion Breakdown and May Contribute to Impaired Healing in Chronic Wounds(A) Schematic represents location, size, and timing of biopsy wound made in healthy human volunteers.(B) H&E staining of a day 3 human acute wound. Advancing epidermal margins are indicated by yellow arrowheads.(C) Human acute wounds were immunostained for ephrin-B1 as revealed by DAB (brown) and dual immunofluorescent staining of ephrin-B1 and E-cadherin (green and red).(D) Individual cell transfected with ephrin-B1:GFP plasmid (green) within a confluent monolayer of HaCaTs. Yellow arrowhead indicates intercellular loosening.(E) Immunostaining of ephrin-B1:GFP cells for E-cadherin. White and yellow arrowheads indicate present or absent E-cadherin staining, respectively, at the interface between transfected cell and all neighbors.(F) Ephrin-B1-transfected cells just behind the wound edge at 15 hr post-scratching. The fixed wound is stained for ephrin-B1 (green) and actin (red). Asterisk indicates intercellular space.(G) Schematic illustrates the location and size of biopsies taken from the margin of patients’ venous leg ulcers.(H) Typical healing (n = 6 patients) and non-healing (n = 6 patients) chronic-wound biopsies immunostained for ephrin-B1 to reveal intensity of ephrhin-B1 staining (low magnification) and degree of cell detachment (high magnification). Asterisks indicate the large intercellular spaces.Scale bars, 400 μm (B), 100 μm (C, left), 25 μm (C, middle), 10 μm (C, right), 20 μm (D), 20 μm (E), 20 μm (F), 250 μm (H, low magnification), and 25 μm (H, high magnification).
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fig7: Overexpression of Ephrin-B1 Leads to Cell-Cell Adhesion Breakdown and May Contribute to Impaired Healing in Chronic Wounds(A) Schematic represents location, size, and timing of biopsy wound made in healthy human volunteers.(B) H&E staining of a day 3 human acute wound. Advancing epidermal margins are indicated by yellow arrowheads.(C) Human acute wounds were immunostained for ephrin-B1 as revealed by DAB (brown) and dual immunofluorescent staining of ephrin-B1 and E-cadherin (green and red).(D) Individual cell transfected with ephrin-B1:GFP plasmid (green) within a confluent monolayer of HaCaTs. Yellow arrowhead indicates intercellular loosening.(E) Immunostaining of ephrin-B1:GFP cells for E-cadherin. White and yellow arrowheads indicate present or absent E-cadherin staining, respectively, at the interface between transfected cell and all neighbors.(F) Ephrin-B1-transfected cells just behind the wound edge at 15 hr post-scratching. The fixed wound is stained for ephrin-B1 (green) and actin (red). Asterisk indicates intercellular space.(G) Schematic illustrates the location and size of biopsies taken from the margin of patients’ venous leg ulcers.(H) Typical healing (n = 6 patients) and non-healing (n = 6 patients) chronic-wound biopsies immunostained for ephrin-B1 to reveal intensity of ephrhin-B1 staining (low magnification) and degree of cell detachment (high magnification). Asterisks indicate the large intercellular spaces.Scale bars, 400 μm (B), 100 μm (C, left), 25 μm (C, middle), 10 μm (C, right), 20 μm (D), 20 μm (E), 20 μm (F), 250 μm (H, low magnification), and 25 μm (H, high magnification).
Mentions: Since ephrin KD had such a dramatic effect on murine wound closure, leading to failure of wound re-epithelialization, we wondered whether defects in Eph-ephrin signaling might be in part causal of defective healing in human patients. Day 3 punch biopsy wounds made on the upper arm skin of normal healthy volunteers (Figures 7A–7C; Figures S7A and S7B) exhibited, as in mouse, epidermal migration that contributed to repair of the wound (Figure 7B). Immunostaining of these wounds revealed a rather similar distribution of ephrin-B1 staining to that of healing murine wounds (Figure 7C), except that expression extended back farther (i.e., 100+ cells back from the wound edge). As in healing mouse wounds, E-cadherin immunostaining appeared largely excluded from the basal layers of epidermis in which ephrin-B1 was expressed (Figure 7C), and resin histology revealed intercellular spaces in the migrating epidermal front (Figure S7B). As a first attempt to investigate a clinical link between Eph-ephrin signaling and wound repair, we undertook a qPCR analysis of ephrin-B1 and associated gene transcripts in human chronic wounds. Venous leg ulcers were stratified according to whether they subsequently healed (n = 20) or not (n = 51) within 3 months after initial referral.

Bottom Line: Much is known about how lead-edge cells migrate, but very little is known about the mechanisms that enable active participation by cells further back.Here we show that ephrin-B1 and its receptor EphB2 are both upregulated in vivo, just for the duration of repair, in the first 70 or so rows of epidermal cells, and this signal leads to downregulation of the molecular components of adherens and tight (but not desmosomal) junctions, leading to loosening between neighbors and enabling shuffle room among epidermal cells.If this signaling axis is perturbed, then disrupted healing is a consequence in mouse and man.

View Article: PubMed Central - PubMed

Affiliation: Schools of Biochemistry and Physiology & Pharmacology, University of Bristol, Bristol BS8 1TD, UK.

No MeSH data available.


Related in: MedlinePlus