Soon after epidermal growth factor (EGF) discovery, some in vivo models appeared demonstrating its property to enhance cutaneous wound healing. EGF was the first growth factor (GF) introduced in the clinical arena as a healing enhancer, exerting its mitogenic effects on epithelial, fibroblastoid, and endothelial cells via a tyrosine kinase membrane receptor. Compelling evidences from the 90s documented that, for EGF, locally prolonged bioavailability and hourly interaction with the receptor were necessary for a successful tissue response. Eventually, the enthusiasm on the clinical use of EGF to steer the healing process was wiped out as the topical route to deliver proteins started to be questioned. The simultaneous in vivo experiments, emphasizing the impact of the parenterally administered EGF on epithelial and nonepithelial organs in terms of mitogenesis and cytoprotection, rendered the theoretical fundamentals for the injectable use of EGF and shaped the hypothesis that locally infiltrating the diabetic ulcers would lead to an effective healing. Although the diabetic chronic wounds microenvironment is hostile for local GFs bioavailability, EGF local infiltration circumvented the limitations of its topical application, thus expanding its therapeutic prospect. Our clinical pharmacovigilance and basic studies attest the significance of the GF local infiltration for chronic wounds healing.

Wound chronification and opportunistic infections stand as major factors leading to lower extremities amputations in diabetes. The molecular mechanisms underlying diabetic's torpid healing have not been elucidated. We present the case of a female diabetic patient that after a plantar abscess surgical drainage, tight glycaemia control and infection clearance; the wound bed evolved to chronification with poor matrix accumulation, scant angiogenesis and no evidence of dermo-epidermal contours contraction. Ulcer fibroblasts yet cultured under 'physiological' conditions exhibited a slow and declining proliferative response. Diabetic fibroblasts cycle arrest occurred earlier than non-diabetic counterparts. This in vitro premature arrest-senescence phenotype appeared related to the transcriptional upregulation of p53 and the proto-oncogene c-myc; with a concomitant expression reduction of the survival and cellular growth promoters Akt and mTOR. Importantly, immunocytochemistry of the diabetic ulcer-derived fibroblasts proved nuclear over expression of potent proliferation inhibitors and pro-senescence proteins as p53 phosphorylated on serine-15 and p21(Cip) (1). In line with this, cyclin D1 appeared substantially underexpressed in these cells. We postulate that the downregulation of the Akt/mTOR/cyclin D1 axis by the proximal activation of p53 and p21 due to stressor factors, impose an arrest/pro-senescence programme that translated in a torpid and slow healing process.

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Decubitus and diabetic foot ulcers remain as important clinical challenges with significant socioeconomic impact. Both are individual forms of chronic wounds with diverse proximal ethiopathogenic triggers. This study aimed to characterize and compare the main histological features as the transcriptional expression profile of a set of wound-healing relevant genes of the ulcers' granulation tissue. Following patients' consent, biopsies were collected from sacrolumbar pressure ulcers (N=5, stage IV) and diabetic foot ulcers (N=9, both of neuropathic and ischemic origin) with clean, non-infected granulation tissue. Biopsies fragments were processed for histological analysis and for RNA extraction and subsequent transcriptional expression characterization via RT-PCR. The group of targeted genes included cell proliferation control, extracellular matrix, glucose metabolism, anabolismsurvival, as anti-hypoxia and anti-oxidant defense. Gene expression was determined, normalized with an internal housekeeping gene, and statistically compared. Each class of chronic ulcer granulation tissue: decubitus, and diabetics' ischemic and neuropathic proved to develop a particular histological pattern thus establishing individual differences. Moreover, diabetes appeared to significantly reduce the expression of numerous genes irrespective to their biological significance. Most importantly, we found that diabetic granulation tissue cells exhibit a sort of "genetic or epigenetic imprinting" for the expression of glucose-metabolism related genes which are deeply involved in type-2 diabetes pathophysiology. Our data indicate that in addition to a protracted inflammation and abnormal angiogenesis, diabetic granulation tissue cells are affected by gene expression failures that may lead to a negative pro-anabolic and energetic balance. J ou rna l o f D ia be tes & M e ta bolism