Bioengineered dermal substitutes for the management of traumatic periocular tissue loss.

PURPOSE: Traumatic periocular injuries occasionally result in significant soft tissue loss, for which there are limited management options that provide satisfactory cosmetic and functional outcomes. The authors describe the use of a bioengineered dermal substitute (Integra® Dermal Regeneration Template [DRT], Integra LifeSciences, Plainsboro, NJ) as an alternative to immediate flap reconstruction or skin grafting. METHODS: Retrospective interventional case series of patients who underwent DRT placement for periocular tissue loss at the time of trauma. In each case, primary closure or immediate flap reconstruction was deemed impractical or undesirable due to the size and location of the primary and associated secondary defects. One to four weeks later, the outer silicone layer was removed and healing assessed. Additional reconstructive techniques were performed as needed. RESULTS: Three patients were treated at Bascom Palmer Eye Institute and one at Byers Eye Institute at Stanford. The defects healed completely in two patients, and by 79.2% in a third, with no need for additional reconstructive surgery. In the remaining patient, the defect was significantly downsized by 56.1%, allowing for a simpler flap reconstruction. CONCLUSIONS: Bioengineered dermal substitutes should be considered as a viable alternative to traditional reconstructive techniques for large periocular defects resulting from trauma. The outer silicone layer prevents desiccation and serves as a protective barrier, while the inner collagen matrix organizes the growth of neo-dermis and minimizes wound contraction. The dimensions of cutaneous defects can therefore be reduced dramatically, potentially eliminating the need for skin grafting and/or reducing the ultimate complexity of flap reconstruction.

RNA-Sequencing Gene Expression Profiling of Orbital Adipose-Derived Stem Cell Population Implicate HOX Genes and WNT Signaling Dysregulation in the Pathogenesis of Thyroid-Associated Orbitopathy.

Purpose: The purpose of this study was to characterize the intrinsic cellular properties of orbital adipose-derived stem cells (OASC) from patients with thyroid-associated orbitopathy (TAO) and healthy controls. Methods: Orbital adipose tissue was collected from a total of nine patients: four controls and five patients with TAO. Isolated OASC were characterized with mesenchymal stem cell-specific markers. Orbital adipose-derived stem cells were differentiated into three lineages: chondrocytes, osteocytes, and adipocytes. Reverse transcription PCR of genes involved in the adipogenesis, chondrogenesis, and osteogenesis pathways were selected to assay the differentiation capacities. RNA sequencing analysis (RNA-seq) was performed and results were compared to assess for differences in gene expression between TAO and controls. Selected top-ranked results were confirmed by RT-PCR. Results: Orbital adipose-derived stem cells isolated from orbital fat expressed high levels of mesenchymal stem cell markers, but low levels of the pluripotent stem cell markers. Orbital adipose-derived stem cells isolated from TAO patients exhibited an increase in adipogenesis, and a decrease in chondrogenesis and osteogenesis. RNA-seq disclosed 54 differentially expressed genes. In TAO OASC, expression of early neural crest progenitor marker (WNT signaling, ZIC genes and MSX2) was lost. Meanwhile, ectopic expression of HOXB2 and HOXB3 was found in the OASC from TAO. Conclusion: Our results suggest that there are intrinsic genetic and cellular differences in the OASC populations derived from TAO patients. The upregulation in adipogenesis in OASC of TAO may be is consistent with the clinical phenotype. Downregulation of early neural crest markers and ectopic expression of HOXB2 and HOXB3 in TAO OASC demonstrate dysregulation of developmental and tissue patterning pathways.

Analysis of single nucleotide polymorphisms in the NOS2A gene and interaction with smoking in age-related macular degeneration.

Age-related macular degeneration (AMD) is a complex degenerative retinal disease influenced by both genetic and environmental risk factors. We assessed whether single nucleotide polymorphisms (SNPs) in the NOS2A gene increase risk and modulate the effect of smoking in AMD. 998 Caucasian subjects (712 AMD cases and 286 controls) were genotyped for 17 SNPs in NOS2A. Multivariable logistic regression models containing SNP genotypes, age, sex, smoking status and genotype/smoking interaction were constructed. SNP rs8072199 was significantly associated with AMD (OR = 1.3; 95% CI : 1.02, 1.65; P = 0.035). A significant interaction with smoking was detected at rs2248814 (P = 0.037). Stratified data by genotypes demonstrated that the association between AMD and smoking was stronger in carriers of AA genotypes (OR = 35.98; 95% CI: 3.19, 405.98) than in carriers of the AG genotype (OR = 3.05; 95% CI: 1.36, 6.74) or GG genotype (OR = 2.1; 95% CI: 0.91, 4.84). The results suggest a possible synergistic interaction of AA genotype with smoking, although the result bears replication in larger samples. Our data suggests that SNPs in the NOS2A gene are associated with increased risk for AMD and might modulate the effect of smoking on AMD.