Autologous skin substitute for hard-to-heal ulcers: retrospective analysis on safety, applicability, and efficacy in an outpatient and hospitalized setting.

Chronic ulcers ((arterio)venous, decubitus, or postoperative) have no tendency to heal within a period of at least 3 months despite optimal therapy according to internationally accepted guidelines. This retrospective study evaluates the safety and efficacy of an autologous, dermal-epidermal skin substitute (SS) for treating ulcers of various origins. Ulcers were treated within 7 Dutch centers over 5 years. Sixty-six ulcers (size: 0.75-150 cm²; duration: 0.25-32 years) with a follow-up time of 24 weeks after a single-skin substitute application were assessed. Wound-bed preparation consisted of vacuum-assisted-closure-therapy (5 days, hospitalized) or application of acellular dermis (5-7 days, outpatient). Time to heal, adverse events, and recurrence 1 year after complete healing were recorded. Complete ulcer healing occurred in 36 of 66 ulcers (55%) at 24 weeks. At that time point, a further 29% of ulcers showed decrease in ulcer size between 50 and 99%. No difference was observed between the hospitalized vs. outpatient treatment with complete healing. There were 32 of 36 healed ulcers that were available for follow-up 1 year after complete closure, of which 27 (84%) were still closed. Only two minor/moderate possibly related adverse events were recorded. This retrospective analysis shows that SS provides a safe and successful treatment for particularly chronic ulcers of various origins.

Simple wound exudate collection method identifies bioactive cytokines and chemokines in (arterio) venous ulcers.

A major challenge for clinicians treating (arterio) venous leg ulcers is to decide between standard therapy and advanced interventions. Here, we developed a simple method to collect human material representative of the ulcer wound bed, which can be used to identify biomarkers for prognostic test development. Superficial surgical debridement was performed using a small vidal curette during the weekly visit to the outpatient clinic. Moist, easily removable debridement material essentially blood free (including necrotic and nonviable slough) was collected from the surface of the ulcer. The amount ranged from 5.5 mg to 78 mg material per ulcer. Seventeen cytokines, chemokines, and growth factors were extracted and analyzed by enzyme-linked immunosorbent assay (concentration range: 0.0005-78 ng/mg total protein). Notably, CXCL8 was by far the most abundant protein present. Inflammatory mediators were more abundant than anti-inflammatory mediators (e.g., interleukin (IL)-10 and transforming growth factor-ß1). Bioactivity assays showed chronic wound extracts to be capable of stimulating fibroblast migration in a chemokine-dependent manner and also capable of stimulating healthy cells within skin substitutes to secrete wound healing mediators (CCL2, CXCL1, CXCL8, IL-6) in an IL-1α dependent manner. Collection of debridement tissue enables investigation of the ulcer environment in an easy noninvasive manner that may be suitable for prognostic test development.

Parkin protects against the toxicity associated with mutant alpha-synuclein: proteasome dysfunction selectively affects catecholaminergic neurons.

One hypothesis for the etiology of Parkinson's disease (PD) is that subsets of neurons are vulnerable to a failure in proteasome-mediated protein turnover. Here we show that overexpression of mutant alpha-synuclein increases sensitivity to proteasome inhibitors by decreasing proteasome function. Overexpression of parkin decreases sensitivity to proteasome inhibitors in a manner dependent on parkin's ubiquitin-protein E3 ligase activity, and antisense knockdown of parkin increases sensitivity to proteasome inhibitors. Mutant alpha-synuclein also causes selective toxicity to catecholaminergic neurons in primary midbrain cultures, an effect that can be mimicked by the application of proteasome inhibitors. Parkin is capable of rescuing the toxic effects of mutant alpha-synuclein or proteasome inhibition in these cells. Therefore, parkin and alpha-synuclein are linked by common effects on a pathway associated with selective cell death in catecholaminergic neurons.

Sequence conservation between mouse and human synphilin-1.

Synphilin-1 has been shown to interact with alpha-synuclein, which in turn is associated with Parkinson's disease. However, the function of synphilin-1 is unknown. We have cloned mouse synphilin in an attempt to describe conserved and therefore likely functional domains. The deduced amino acid sequence of the protein shows extensive homology with its human counterpart, with greatest similarities in those regions that contain ankyrin-like motifs and the coiled-coil domain. Expression of mouse synphilin-1 across tissues is similar to its human counterpart and not limited to brain. The results show that the synphilin-1 sequence and expression patterns are conserved across species.