Characterization of the Cicatrization Process in Diabetic Foot Ulcers Based on the Production of Reactive Oxygen Species.

The present study aims at evaluating the correlation between the free radical formation and the healing action of lower limbs' ulcers in a randomized controlled trial with the use of an adhesive derived from natural latex associated with a light-emitting diode (LED) circuit. The sample consists of 15 participants with lower limb lesions divided into three groups: group 1 case (5 participants) received the proposed dressing system adhesive of the natural latex associated with the LED circuit; group 2 control (5 participants) received the dressings at home performed by nurses according to and established by the clinic of wounds (treated with calcium alginate or silver foam); and group 3 (5 participants) also received the dressing in their homes with the use of the dressing adhesive derived from the natural latex associated with the LED circuit. The collected data were analyzed qualitatively and quantitatively by electron paramagnetic resonance for determination of free radical formation. Kruskal-Wallis statistical test was used to evaluate the effect of treatment on the lower limb's ulcer cicatrization process and its correlation with free radical. The results obtained corroborated the hypothesis about the reduction of the quantity of these molecules in the end of treatment related to the healing wound.

Efficacy and safety of the combination of isosorbide dinitrate spray and chitosan gel for the treatment of diabetic foot ulcers: A double-blind, randomized, clinical trial.

AIM: To evaluate whether a combination of isosorbide dinitrate spray and chitosan gel (10%) topically applied can have additive benefits for management of diabetic foot ulcers. METHODS: In a randomized, placebo-controlled, double-blinded clinical trial, 68 patients were divided into four groups: Group 1: treated with chitosan gel; Group 2: isosorbide dinitrate spray; Group 3: combination of isosorbide dinitrate spray and chitosan gel; Group 4: placebo. RESULTS: Histological analyses showed a significant regeneration in all groups ( p < 0.001). On the final assessment of the ulcer, using the combination was found a wound closure percentage of 71 ± 30, 70 ± 27 using isosorbide dinitrate, 58 ± 30 with chitosan and 50 ± 16 with placebo. The number of patients who achieved complete ulcer closure was six using the combination, four with isosorbide dinitrate, three with chitosan and one with placebo. The progression in the healing process of the ulcer showed marked inmunohistochemical differences of Von Willebrand Factor, desmin, vascular endothelial growth factor-A and α-smooth muscle actin in all groups ( p < 0.001), but without notable differences between them. CONCLUSION: The combination was better than placebo to reduce the dimensions of the ulcer, accelerate healing and increase the number of patients who achieved complete closure of the ulcer, but the combination was not better than chitosan or isosorbide dinitrate used separately.

Heberprot-P's Effect on Gene Expression in Healing Diabetic Foot Ulcers.

NTRODUCTION Diabetic foot ulcers are a chronic complication in patients with diabetes mellitus. They appear as a result of the combination of diabetic polyneuropathy and angiopathy, and in many cases require amputation of the affected extremity. Clinical trials have demonstrated that repeated local infiltration with Heberprot-P can improve healing of chronic diabetic foot ulcers. Although there is evidence of its effects as a granulation stimulator and on cell migration and proliferation, genetic control mechanisms explaining its anti-inflammatory and oxidative stress reduction properties are not yet thoroughly understood. OBJECTIVE Analyze changes in expression of genes involved in healing after treatment of diabetic foot ulcers with Heberprot-P. METHODS Biopsies were collected from diabetic foot ulcers of 10 responding patients before and after 2 weeks' treatment with Heberprot-P (75-µg applied intralesionally 3 times per week). Total RNA was obtained and quantitative PCR used to determine expression of 26 genes related to inflammation, oxidative stress, cell proliferation, ngiogenesis and extracellular matrix formation. Genetic expression was quantified before and after treatment using REST 2009 v2.0.13. RESULTS After treatment, there was a statistically significant increase in expression of genes related to cell proliferation, angiogenesis and formation of extracellular matrix (PDGFB, CDK4, P21, TP53, ANGPT1, COL1A1, MMP2 and TIMP2). A significant decrease was observed in gene expression related to inflammatory processes and oxidative stress (NFKB1, TNFA and IL-1A). CONCLUSIONS Our findings suggest that Heberprot-P's healing action on diabetic foot ulcers is mediated through changes in genetic expression that reduce hypoxia, inflammation and oxidative stress, and at the same time increase cell proliferation, collagen synthesis and extracellular matrix remodeling. The kinetics of expression of two genes related to extracellular matrix formation needs further exploration. KEYWORDS Epidermal growth factor, EGF, diabetic foot ulcer, wound healing, quantitative real-time PCR, gene expression, Cuba.

Calcitriol promotes proangiogenic molecules in keratinocytes in a diabetic foot ulcer model.

Foot ulceration is one of the most common and complex sequelae of diabetes mellitus, generally posing a therapeutic challenge due to poor healing responses and high rates of complications, including peripheral vascular disease, ischemia and infections. Calcitriol, the most active vitamin D metabolite, induces antimicrobial peptides production in keratinocytes from diabetic foot ulcers (DFU); however, little is known about its effects on angiogenic factors in this pathology. Herein we aimed at studying whether calcitriol induces angiogenic molecules in keratinocytes under normoxic and hypoxic conditions, and if these molecules are able to improve cell migration in vitro. Evaluation of DFU samples by immunohistochemistry showed increased VEGF and decreased angiogenin and HIF-1α expression compared to controls, suggesting an altered pattern of angiogenic factors in DFU. Interestingly, incubation of keratinocytes with calcitriol significantly upregulated VEGFA, HIF-1α and angiogenin gene expression, while the resulting cell culture media stimulated both endothelial cells and keratinocytes migration in an in vitro wound closure assay under a normoxic environment (p<0.05). Moreover, the culture media of calcitriol-treated keratinocytes stimulated cell migration in a similar extent as exogenous VEGF or EGF in endothelial and keratinocytes cells. These results suggest that the altered profile of angiogenic molecules in DFU might be improved by local or systemic treatment with calcitriol under normoxic conditions, which could probably be achieved with hyperbaric oxygen therapy. Given that calcitriol not only augments proangiogenic factors but also induces antimicrobial peptides expression, this hormone should be further investigated in clinical trials of DFU.

Expression of high-mobility group box protein 1 in diabetic foot atherogenesis.

The role of high mobility group box 1 (HMGB1) has been demonstrated in stroke and coronary artery disease but not in peripheral arterial occlusive disease (PAOD). The pathogenesis of HMGB1 in acute and chronic vascular injury is also not well understood. We hypothesized that HMGB1 induces inflammatory markers in diabetic PAOD patients. We studied 36 diabetic patients, including 29 patients with PAOD, who had undergone amputation for diabetic foot and 7 nondiabetic patients who had undergone amputation after traumatic injury. Expression of HMGB1 and inflammatory markers were quantified using immunohistochemical staining. Mitochondrial DNA copy number was quantified using real-time polymerase chain reaction. Compared with that in the traumatic amputation group, HMGB1 expression in vessels was significantly higher in the diabetes and diabetic PAOD groups. In all subjects, arterial stenosis grade was positively correlated with the expression levels of HMGB1, 8-hydroxyguanosine, malondialdehyde, vascular cell adhesion molecule 1, and inflammatory markers CD3, and CD68 in both the intima and the media of vessels. Furthermore, HMGB1 expression level was positively correlated with 8-hydroxyguanosine, vascular cell adhesion molecule 1, nuclear factor-kB, CD3, and CD68 expression. Within the PAOD subgroup, subjects with HMGB1 expression had higher expression of the autophagy marker LC3A/B and higher mitochondrial DNA copy number. HMGB1 may be an inflammatory mediator with roles in oxidative damage and proinflammatory and inflammatory processes in diabetic atherogenesis. Moreover, it may have dual effects by compensating for increased mitochondrial DNA copy number and increased autophagy marker expression.

1,25-dihydroxyvitamin D3 induces LL-37 and HBD-2 production in keratinocytes from diabetic foot ulcers promoting wound healing: an in vitro model.

Diabetic foot ulcers (DFU) are one of the most common diabetes-related cause of hospitalization and often lead to severe infections and poor healing. It has been recently reported that patients with DFU have lower levels of antimicrobial peptides (AMPs) at the lesion area, which contributes with the impairment of wound healing. The aim of this study was to determine whether 1,25-dihydroxyvitamin D3 (1,25 (OH)2 D3) and L-isoleucine induced HBD-2 and LL-37 in primary cultures from DFU. We developed primary cell cultures from skin biopsies from 15 patients with DFU and 15 from healthy donors. Cultures were treated with 1,25 (OH)2D3 or L-isoleucine for 18 h. Keratinocytes phenotype was identified by western blot and flow cytometry. Real time qPCR for DEFB4, CAMP and VDR gene expression was performed as well as an ELISA to measure HBD-2 and LL-37 in supernatant. Antimicrobial activity, in vitro, wound healing and proliferation assays were performed with conditioned supernatant. The results show that primary culture from DFU treated with 1,25(OH)2D3, increased DEFB4 and CAMP gene expression and increased the production of HBD-2 and LL-37 in the culture supernatant. These supernatants had antimicrobial activity over E. coli and induced remarkable keratinocyte migration. In conclusion the 1,25(OH)2D3 restored the production of AMPs in primary cell from DFU which were capable to improve the in vitro wound healing assays, suggesting their potential therapeutic use on the treatment of DFU.

Expression of cell proliferation cycle negative regulators in fibroblasts of an ischemic diabetic foot ulcer. A clinical case report.

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.

Expression of antimicrobial peptides in diabetic foot ulcer.

BACKGROUND: Foot ulcers are one of the main diabetes complications due to its high frequency and difficulty of complete healing. There are several factors that participate in diabetic ulcers development and limited information exists about the role of antimicrobial peptides (AMP) in its pathogenesis. OBJECTIVE: The aim of this study was to analyze the expression pattern of the main AMPs: Human Neutrophil Peptide (HNP)-1, Human ß-defensin (HBD)-1, HBD-2, HBD-3, HBD-4 and cathelicidin LL-37 in biopsies from diabetic foot ulcers (DFU). METHODS: 20 biopsies from DFU grade 3 according to Wagner's classification and 20 biopsies from healthy donors were obtained. Real time PCR, immunohistochemistry and primary cell cultures were performed. RESULTS: ß-Defensins were overexpressed in DFU, whereas LL-37 has low or none expression in comparison with healthy skin. When primary cell culture from these biopsies were performed and infected with Staphylococcus aureus, epidermal cell from diabetic ulcers showed lower LL-37 expression compared with cell cultures from healthy donors skin. CONCLUSION: These results suggest that though most AMPs are expressed in DFU, this production is not appropriate to promote wound healing and contain secondary infections.

De Marco Formula effectiveness as an adjunctive therapy to prevent infected ischemic diabetic foot amputation and reduce plasma fibrinogen.

BACKGROUND: De Marco Formula (DMF) is a new procaine chemical combination of Procaine HCl and polyvinylpyrrolidone. A prospective randomized controlled clinical trial demonstrated that infected ischemic diabetic foot treatment with DMF for 52 days as an adjuvant with conventional therapy reduced major amputations. OBJECTIVE: To evaluate the possible association of clinical effectiveness and plasma fibrinogen reduction with DMF therapy. METHODS: Adult patients, 24 male/23 female, suffering from infected ischemic diabetic foot ulcers were randomly assigned to receive conventional therapy alone (group A, N=24) or combined with DMF (receiving 0, 15 ml/kg day i.m.) for ten days and then twice a week until lesion healing or completion of 52 days (group B, N=23). Fibrinogen concentrations were determined before and after a ten-day treatment period. Treatment clinical responses were considered favorable if major amputations were not needed. Pre and post-treatment fibrinogen values were compared within each group and between groups. Differences were considered statistically significant for p<0, 05. RESULTS: Fifty percent of group A patients (12/24) and 21.7% of the Group B (5/23) showed unfavorable responses (a 56.6% reduction for group B). There were not statistical differences between pre and post-treatment fibrinogen within Group A (406.7±49.08 vs. 354.6±62.5, p=0,11). However, post-treatment values were significantly lower within Group B (298.9±15.24 vs. 487.1±49.08, p=0, 0016). Patients who showed favorable responses had statistically lower fibrinogen concentrations than those with unfavorable responses (280±5.1 vs. 310±7,1, p=0.002) within group B. CONCLUSION: DMF combined with conventional therapy for infected ischemic diabetic foot was associated with plasma fibrinogen decrease.