Site-specific variation in the activity of COX-2 alters the pattern of wound healing in the tail and limb of northern house gecko by differentially regulating the expression of local inflammatory mediators

The Role of IL-22 in Wound Healing. Potential Implications in Clinical Practice

“…We included in this subcategory the one study with mixed clinical and experimental design [ 15 ], referring only toward the experimental part of the study; the clinical study will be discussed in the respective subcategory. Three studies [ 18 , 20 , 22 ] referred to skin wounds (33.33% out of nine experimental studies), one [ 19 ] to oral mucosa injury (11.11%), and another [ 23 ] to corneal abrasion (11.11%), while one [ 13 ] study discussed intestinal lesions (11.11%), one [ 12 ] study analyzed colon and skin lesions (11.11%), one [ 15 ] study analyzed peritoneal adhesions formation (11.11%), and another study [ 11 ] referred to appendix (limb/tail) amputations (11.11%). One study [ 11 ] used lizards as experimental animals (for their differential wound healing in two different body parts—limb versus tail), while the others utilized mice.…”

“…Three studies [ 18 , 20 , 22 ] referred to skin wounds (33.33% out of nine experimental studies), one [ 19 ] to oral mucosa injury (11.11%), and another [ 23 ] to corneal abrasion (11.11%), while one [ 13 ] study discussed intestinal lesions (11.11%), one [ 12 ] study analyzed colon and skin lesions (11.11%), one [ 15 ] study analyzed peritoneal adhesions formation (11.11%), and another study [ 11 ] referred to appendix (limb/tail) amputations (11.11%). One study [ 11 ] used lizards as experimental animals (for their differential wound healing in two different body parts—limb versus tail), while the others utilized mice. All studies except one [ 13 ] reported the positive involvement of IL-22 in tissue repair; one study [ 13 ] reported IL-22-independent healing pathways in intestinal lesions.…”

“…Regarding intestinal injury, both IL-22-dependent and IL-22-independent pathways seem to have important roles in tissue repair [ 12 , 13 ]. One interesting report [ 11 ] shows that IL-22 plays a role in both restorative scarless healing and healing through scar tissue in lizards, the cytokine constellation guiding each type of healing. In summary, the experimental studies show that IL-22 mediates the interaction between immune cells and local cells involved in the proliferation and remodeling phase of wound healing.…”

Self-Control of Inflammation during Tail Regeneration of Lizards

“…It is interesting to note that proinflammatory mediators cyclooxygenases 2 (COX2) and prostaglandin E2 (PGE2) are upregulated at the injured site following gecko tail and limb amputation. However, the different outcomes are observed with non-inflammatory activation in the damaged tail but proinflammatory activation in the damaged limb [ 65 ]. During the early healing phase of the tail, EP4 receptor of PGE2 is simultaneously increased, and PGE2-EP4 interaction is correlated to early resolution of inflammation by increasing the anti-inflammatory mediator interleukin-10 (IL-10) and decreasing proinflammatory mediators inducible nitric oxide synthase (iNOS), tumour necrosis factor-alpha (TNF-α), IL-6, IL-17 and IL-22.…”

“…In contrast, the expression of EP2, rather than EP4, is upregulated in the limb. The binding of PGE2 with EP2 leads to the increase of proinflammatory mediators and the reduction of anti-inflammatory mediators [ 65 ]. Such a strategy of the lizard for preventing the activation of inflammation from a tail injury is likely ancient and very efficient.…”