Management of urosymphyseal fistula and pubic bone osteomyelitis: Description of a new surgical technique by cystectomy, urinary diversion and pelvic filling flap by unilateral pedicled myocutaneous vertical rectus abdominus muscle flap.

Pubic bone osteomyelitis is a rare infection, mostly related to urinary fistula. The published data about the medical or surgical management of this type of infection is relatively poor. In this case study of three patients, we describe our surgical technique for the management of urosymphyseal fistula complicated with pubic bone infection using pelvic filling flap by unilateral pedicled myocutaneous vertical rectus abdominus muscle flap. The first patient had the pelvic space filled with omentum flap. Unfortunately, the patient presented, postoperatively, an enteric fistula resulting from intestine incarceration on the resected bone. Considering this failure, the next two cases, have benefited from a Taylor flap to protect the peritoneal cavity by covering the residual pubic bone. Early complications were pyelonephritis and anemia (Clavien-Dindo 2), but no repeat surgery was required afterwards. The hospital stay for both cases were 26- and 12-days contrary to the first case who was hospitalized for 180-days. In conclusion, despite our limited experience in managing complicated urosymphyseal fistula, Taylor's flap, mainly used for gynecological or rectal surgery, might be a good reproducible solution for the surgical management of this kind of fistula with pubic debridement. It allows to protect the peritoneal cavity with fewer postoperative complications.

IL-17 and IL-22 are pivotal cytokines to delay wound healing of S. aureus and P. aeruginosa infected skin.

Introduction: Although the presence of pathogens in skin wounds is known to delay the wound healing process, the mechanisms underlying this delay remain poorly understood. In the present study, we have investigated the regulatory role of proinflammatory cytokines on the healing kinetics of infected wounds. Methods: We have developed a mouse model of cutaneous wound healing, with or without wound inoculation with Staphylococcus aureus and Pseudomonas aeruginosa, two major pathogens involved in cutaneous wound bacterial infections. Results: Aseptic excision in C57BL/6 mouse skin induced early expression of IL-1ß, TNFα and Oncostatin M (OSM), without detectable expression of IL-22 and IL-17A/F. S. aureus and P. aeruginosa wound inoculation not only increased the expression of IL-1ß and OSM, but also induced a strong cutaneous expression of IL-22, IL-17A and IL-17F, along with an increased number of infiltrating IL-17A and/or IL-22-producing γδ T cells. The same cytokine expression pattern was observed in infected human skin wounds. When compared to uninfected wounds, mouse skin infection delayed the wound healing process. Injection of IL-1α, TNFα, OSM, IL-22 and IL-17 together in the wound edges induced delayed wound healing similar to that induced by the bacterial infection. Wound healing experiments in infected Rag2KO mice (deficient in lymphocytes) showed a wound healing kinetic similar to uninfected Rag2KO mice or WT mice. Rag2KO infected-skin lesions expressed lower levels of IL-17 and IL-22 than WT, suggesting that the expression of these cytokines is mainly dependent on γδ T cells in this model. Wound healing was not delayed in infected IL-17R/IL-22KO, comparable to uninfected control mice. Injection of recombinant IL-22 and IL-17 in infected wound edges of Rag2KO mice re-establish the delayed kinetic of wound healing, as in infected WT mice. Conclusion: These results demonstrate the synergistic and specific effects of IL-22 and IL-17 induced by bacterial infection delay the wound healing process, regardless of the presence of bacteria per se. Therefore, these cytokines play an unexpected role in delayed skin wound healing.

Oncostatin M exerts a protective effect against excessive scarring by counteracting the inductive effect of TGFß1 on fibrosis markers.

Wound healing is a complex physiological process that repairs a skin lesion and produces fibrous tissue. In some cases, this process can lead to hypertrophic scars (HS) or keloid scars (KS), for which the pathophysiology remains poorly understood. Previous studies have reported the presence of oncostatin M (OSM) during the wound healing process; however, the role of OSM in pathological scarring remains to be precisely elucidated. This study aims to analyse the presence and involvement of OSM in the pathological scarring process. It was conducted with 18 patients, including 9 patients with hypertrophic scarring and 9 patients with keloid scarring. Histological tissue analysis of HS and KS showed minor differences in the organization of the extracellular matrix, the inflammatory infiltrate and the keratinocyte phenotype. Transcriptomic analysis showed increased expression levels of fibronectin, collagen I, TGFß1, ß-defensin-2 and S100A7 in both pathological samples. OSM expression levels were greater in HS than in KS and control skin. In vitro, OSM inhibited TGFß1-induced secretion of components of the extracellular matrix by normal and pathological fibroblasts. Overall, we suggest that OSM is involved in pathological wound healing processes by inhibiting the evolution of HS towards KS by controlling the fibrotic effect of TGFß1.

Oncostatin M is overexpressed in skin squamous-cell carcinoma and promotes tumor progression.

Cutaneous squamous cell carcinoma (cSCC) is the second most common keratinocyte malignancy and accounts for 20% of skin cancer deaths. Cancer is closely related to inflammation, but the contribution of the tumor microenvironment to cSCC development is poorly understood. We previously showed that oncostatin M (OSM), a cytokine belonging to the IL-6 family, promotes normal keratinocyte proliferation and migration, skin inflammation, and epidermal hyperplasia, both in vitro and in vivo. Here, we show that OSM is overexpressed in human cSCC and is associated with type 1 immune polarization. In vitro, OSM induced STAT-3 and ERK signaling, modified the expression of genes involved in cytokine signaling, proliferation, inhibition of apoptosis, and immune responses, and promoted proliferation and migration of malignant keratinocyte PDVC57 cells. PDVC57 cells grafted in the skin of mice led to rapid cSCC development, associated with OSM expression by tumor-infiltrating neutrophils. Finally, the absence of OSM (OSM-KO mice) led to a 30% reduction of tumor size and reduced M2 polarization in the tumor microenvironment. Globally, these results support a pro-tumoral role of OSM in cSCC development and suggest that a new therapeutic approach targeting this cytokine could be considered.

Development of a new model of reconstituted mouse epidermis and characterization of its response to proinflammatory cytokines.

The development of three-dimensional models of reconstituted mouse epidermis (RME) has been hampered by the difficulty to maintain murine primary keratinocyte cultures and to achieve a complete epidermal stratification. In this study, a new protocol is proposed for the rapid and convenient generation of RME, which reproduces accurately the architecture of a normal mouse epidermis. During RME morphogenesis, the expression of differentiation markers such as keratins, loricrin, filaggrin, E-cadherin and connexins was followed, showing that RME structure at day 5 was similar to those of a normal mouse epidermis, with the acquisition of the natural barrier function. It was also demonstrated that RME responded to skin-relevant proinflammatory cytokines by increasing the expression of antimicrobial peptides and chemokines, and inhibiting epidermal differentiation markers, as in the human system. This new model of RME is therefore suitable to investigate mouse epidermis physiology further and opens new perspectives to generate reconstituted epidermis from transgenic mice.

Interleukin-17A-induced production of acute serum amyloid A by keratinocytes contributes to psoriasis pathogenesis.

BACKGROUND: Acute-serum Amyloid A (A-SAA), one of the major acute-phase proteins, is mainly produced in the liver but extra-hepatic synthesis involving the skin has been reported. Its expression is regulated by the transcription factors NF-κB, C/EBPß, STAT3 activated by proinflammatory cytokines. OBJECTIVES: We investigated A-SAA synthesis by resting and cytokine-activated Normal Human Epidermal Keratinocytes (NHEK), and their inflammatory response to A-SAA stimulation. A-SAA expression was also studied in mouse skin and liver in a model mimicking psoriasis and in the skin and sera of psoriatic and atopic dermatitis (AD) patients. METHODS: NHEK were stimulated by A-SAA or the cytokines IL-1α, IL-17A, IL-22, OSM, TNF-α alone or in combination, previously reported to reproduce features of psoriasis. Murine skins were treated by imiquimod cream. Human skins and sera were obtained from patients with psoriasis and AD. A-SAA mRNA was quantified by RT qPCR. A-SAA proteins were dosed by ELISA or immunonephelemetry assay. RESULTS: IL-1α, TNF-α and mainly IL-17A induced A-SAA expression by NHEK. A-SAA induced its own production and the synthesis of hBD2 and CCL20, both ligands for CCR6, a chemokine receptor involved in the trafficking of Th17 lymphocytes. A-SAA expression was increased in skins and livers from imiquimod-treated mice and in patient skins with psoriasis, but not significantly in those with AD. Correlations between A-SAA and psoriasis severity and duration were observed. CONCLUSION: Keratinocytes could contribute to psoriasis pathogenesis via A-SAA production, maintaining a cutaneous inflammatory environment, activating innate immunity and Th17 lymphocyte recruitment.

Inhibition of keratinocyte differentiation by the synergistic effect of IL-17A, IL-22, IL-1α, TNFα and oncostatin M.

Keratinocyte differentiation program leading to an organized epidermis plays a key role in maintaining the first line of defense of the skin. Epidermal integrity is regulated by a tight communication between keratinocytes and leucocytes, particularly under cytokine control. Imbalance of the cytokine network leads to inflammatory diseases such as psoriasis. Our attempt to model skin inflammation showed that the combination of IL-17A, IL-22, IL-1α, OSM and TNFα (Mix M5) synergistically increases chemokine and antimicrobial-peptide expression, recapitulating some features of psoriasis. Other characteristics of psoriasis are acanthosis and down-regulation of keratinocyte differentiation markers. Our aim was to characterize the specific roles of these cytokines on keratinocyte differentiation, and to compare with psoriatic lesion features. All cytokines decrease keratinocyte differentiation markers, but IL-22 and OSM were the most powerful, and the M5 strongly synergized the effects. In addition, IL-22 and OSM induced epidermal hyperplasia in vitro and M5 induced epidermal thickening and decreased differentiation marker expression in a mouse model, as observed in human psoriatic skin lesions. This study highlights the precise role of cytokines in the skin inflammatory response. IL-22 and OSM more specifically drive epidermal hyperplasia and differentiation loss while IL-1α, IL-17A and TNFα were more involved in the activation of innate immunity.

Medial thighplasty after massive weight loss: are there any risk factors for postoperative complications?

BACKGROUND: With the increasing incidence of obesity in Western societies, an increasing number of patients undergo bariatric surgery that leads to functional and aesthetic sequelae related to a rapid and massive weight loss, namely, skin and fat excess. The goal of surgical management after massive weight loss is to optimize the functional results obtained from bariatric surgery or diet by removal of the redundant skin folds. The authors report their experience with medial thighplasty after massive weight loss and identify factors predictive of postoperative complications. METHODS: This retrospective study investigated 53 patients who underwent surgery for medial thighplasty after massive weight loss. Data were collected through chart review and submitted to statistical analysis. RESULTS: The average weight loss before thighplasty was 43.5 ± 14.9 kg, and 39.6 % of the patients experienced at least one complication. The complications were seroma (9.4 %), wound dehiscence (20.8 %), scar migration (17 %), wound infection (5.7 %), and partial skin necrosis (1.9 %). The body mass index (BMI) before massive weight loss and the BMI before medial thighplasty were found to be risk factors for the development of a postoperative complication. CONCLUSION: Few guidelines exist for the optimization of care and safety in this complex patient population. The information from this retrospective study complements the current data from the literature and can help surgeons select patients eligible for medial thighplasty. This report shows that the BMI before medial thighplasty should be taken into consideration for patients willing to undergo a body-contouring procedure. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Involvement of IL-1 and oncostatin M in acanthosis associated with hypertensive leg ulcer.

Hypertensive leg ulcer (HLU) is an inflammatory disease characterized by intense pain, alteration of vascularization, and skin necrosis. The optimal treatment relies on surgical removal of necrotic tissues covered by a split-skin graft. We studied the histomorphology of the lesions and investigated the involvement of inflammatory cells and cytokines to further define the physiopathology of HLU. We report epidermis acanthosis and a preferential occlusion of the precapillary arterioles with infiltration of neutrophils, macrophages, and T lymphocytes in the dermis. OSM, IL-1ß, and IL-6 were overexpressed in the ulcer, whereas the Th17-derived cytokines were not. In vitro, the addition of IL-1ß and OSM promoted acanthosis and destructuring of reconstructed epidermis. Exogenous IL-1ß and OSM synergistically induced epidermal acanthosis in mice. These data show that OSM and IL-1ß are not only a biological characteristic signature of HLU, but these cytokines reflect a specific inflammatory state, directly involved in the pathogenesis. We suggest that anti-cytokine biotherapies could be an alternative strategy to surgery to treat HLU.

Skin Inflammation Induced by the Synergistic Action of IL-17A, IL-22, Oncostatin M, IL-1{alpha}, and TNF-{alpha} Recapitulates Some Features of Psoriasis.

Keratinocytes play a crucial role in the regulation of skin inflammation, responding to environmental and immune cells stimuli. They produce soluble factors that can act in an autocrine or paracrine manner on immune cells or directly on aggressors. A screening of the activities of 36 cytokines on keratinocyte gene expression identified IL-17A, IL-22, oncostatin M, TNF-alpha, and IL-1alpha as potent cytokines in inducing cutaneous inflammation. These five proinflammatory cytokines synergistically increased production of CXCL8 and beta-defensin 2 (BD2). In addition, ex vivo studies on human skin explants demonstrated upregulation of BD2, S100A7, and CXCL8 expression in response to the same combination of cytokines. In vivo intradermal injection of these five cytokines in mouse increased CXCL1, CXCL2, CXCL3, S100A9, and BD3 expression, associated with neutrophil infiltration. We confirmed and extended this synergistic effect using quantitative real-time PCR analysis and observed increased expression of nine chemokines and 12 antimicrobial peptides. Production of CXCL, CXCL5, and CXCL8 by keratinocytes stimulated in the presence of this cytokine combination was associated with increased neutrophil chemotactic activity. Similarly, high production of BD2, BD3, and S100A7 was associated with an increased antimicrobial activity. Finally, the transcriptional profile observed in this in vitro model of inflammatory keratinocytes correlated with the one of lesional psoriatic skin. Our results demonstrate the important potentiating activities of IL-17A, IL-22, oncostatin M, TNF-alpha, and IL-1alpha on keratinocytes. This is particularly interesting in the context of psoriasis where these cytokines are overexpressed and could synergize to play an important role in upregulation of chemokines and antimicrobial peptides production.