Establishing a Collaborative Genomic Repository for Adult Burn Survivors: A Burn Model System Feasibility Study.

In this study, we aimed to integrate a genetic repository with an existing longitudinal national burn database. We set out two primary objectives, namely (1) to develop standard operating procedures for genetic sample collection and storage, DNA isolation, and data integration into an existing multicenter database; and (2) to demonstrate the feasibility of correlating genetic variation to functional outcomes in a pilot study, using the catechol-O-methyltransferase (COMT) gene. Dubbed the worrier/warrior gene, COMT variants have been associated with varying phenotypes of post-traumatic stress, wellbeing, and resilience.

Using multiplexed functional data to reduce variant classification inequities in underrepresented populations.

Background: Multiplexed Assays of Variant Effects (MAVEs) can test all possible single variants in a gene of interest. The resulting saturation-style functional data may help resolve variant classification disparities between populations, especially for Variants of Uncertain Significance (VUS).

Methods: We analyzed clinical significance classifications in 213,663 individuals of European-like genetic ancestry versus 206,975 individuals of non-European-like genetic ancestry from All of Us and the Genome Aggregation Database.

Guidelines for releasing a variant effect predictor.

Computational methods for assessing the likely impacts of mutations, known as variant effect predictors (VEPs), are widely used in the assessment and interpretation of human genetic variation, as well as in other applications like protein engineering. Many different VEPs have been released to date, and there is tremendous variability in their underlying algorithms and outputs, and in the ways in which the methodologies and predictions are shared. This leads to considerable challenges for end users in knowing which VEPs to use and how to use them.

Defining and Reducing Variant Classification Disparities.

Background: Multiplexed Assays of Variant Effects (MAVEs) can test all possible single variants in a gene of interest. The resulting saturation-style data may help resolve variant classification disparities between populations, especially for variants of uncertain significance (VUS).

Methods: We analyzed clinical significance classifications in 213,663 individuals of European-like genetic ancestry versus 206,975 individuals of non-European-like genetic ancestry from and the Genome Aggregation Database.

Minimum information and guidelines for reporting a multiplexed assay of variant effect.

Multiplexed assays of variant effect (MAVEs) have emerged as a powerful approach for interrogating thousands of genetic variants in a single experiment. The flexibility and widespread adoption of these techniques across diverse disciplines have led to a heterogeneous mix of data formats and descriptions, which complicates the downstream use of the resulting datasets. To address these issues and promote reproducibility and reuse of MAVE data, we define a set of minimum information standards for MAVE data and metadata and outline a controlled vocabulary aligned with established biomedical ontologies for describing these experimental designs.

Workshop report: the clinical application of data from multiplex assays of variant effect (MAVEs), 12 July 2023.

Clinical classification of genomic variants identified on sequencing is often challenging, with many variants classified as Variants of Uncertain Significance (VUS) on account of insufficient evidence. Advances in sequencing and gene synthesis has made feasible multiplexed assays of variant effect (MAVEs), which quantify the functional impact of many thousands of genomic variants in a single experiment. These assays and the functional evidence they generate have the potential to empower more accurate clinical variant classification.

Minimum information and guidelines for reporting a Multiplexed Assay of Variant Effect.

Multiplexed Assays of Variant Effect (MAVEs) have emerged as a powerful approach for interrogating thousands of genetic variants in a single experiment. The flexibility and widespread adoption of these techniques across diverse disciplines has led to a heterogeneous mix of data formats and descriptions, which complicates the downstream use of the resulting datasets. To address these issues and promote reproducibility and reuse of MAVE data, we define a set of minimum information standards for MAVE data and metadata and outline a controlled vocabulary aligned with established biomedical ontologies for describing these experimental designs.

An Atlas of Variant Effects to understand the genome at nucleotide resolution.

Sequencing has revealed hundreds of millions of human genetic variants, and continued efforts will only add to this variant avalanche. Insufficient information exists to interpret the effects of most variants, limiting opportunities for precision medicine and comprehension of genome function. A solution lies in experimental assessment of the functional effect of variants, which can reveal their biological and clinical impact.

Correlation Between the Warrior/Worrier Gene on Post Burn Pruritus and Scarring: A Prospective Cohort Study.

Introduction: Associations between genetic variation and clinical conditions suggest that single nucleotide polymorphisms (SNPs) might correlate with postburn outcomes. COMT modulates catecholamine metabolism, and polymorphisms within the rs4680 allele result in variable enzyme activity. Catechol-amines are known to modulate the inflammatory process and may affect scar formation.

The Effects of Early Neuropathic Pain Control With Gabapentin on Long-Term Chronic Pain and Itch in Burn Patients.

Gabapentin has analgesic efficacy for neuropathic pain and is increasingly used in burn care. This study investigated the effect of a neuropathic pain control protocol, as well as early gabapentin initiation (<72 hours from injury) on total inpatient opioid use, chronic pain, and itch. This is a single-institution retrospective cohort study of patients over age 14 admitted between 2006 and 2016 with burns.

MC1R gene polymorphisms are associated with dysfunctional immune responses and wound infection after burn injury.

Background: Systemic inflammatory response syndrome (SIRS) is associated with organ failure and infectious complications after major burn injury. Recent evidence has linked melanocortin signaling to anti-inflammatory and wound-repair functions, with mutations in the melanocortin 1 receptor (MC1R) gene leading to increased inflammatory responses. Our group has previously demonstrated that MC1R gene polymorphisms are associated with postburn hypertrophic scarring.

Use of Best Practice Strategies to Improve Longitudinal Study Participation: Analysis of Telephone Contact Data From the Northwest Regional Burn Model System.

Successful acquisition of survey data in any longitudinal study is key to reducing bias and determining reliable, generalizable findings. As part of a multicenter longitudinal study of patient-reported outcomes, a minimum benchmark for follow-up was set at 80%. In review of our center's participation, we found this benchmark was not consistently met.

Melanocortin-1 Receptor Polymorphisms and the Risk of Complicated Sepsis After Trauma: A Candidate Gene Association Study.

Objective: The aim of the study was to determine if melanocortin-1 receptor (MC1R) single nucleotide polymorphisms (SNPs) are associated with complicated sepsis after trauma.

Background: Nosocomial infections are an important cause of morbidity and mortality after trauma. Several SNPs in inflammation-related genes have been associated with sepsis.

Dermal Fibroblasts from the Red Duroc Pig Have an Inherently Fibrogenic Phenotype: An In Vitro Model of Fibroproliferative Scarring.

Background: The pathophysiology of hypertrophic scarring is unknown in part because of the lack of a robust animal model. Although the red Duroc pig has emerged as a promising in vivo model, the cellular mechanisms underlying Duroc scarring are unknown, and the size and cost of Duroc pigs are obstacles to their use. Given the central role of the dermal fibroblast in scarring, the authors hypothesized that dermal fibroblasts from the Duroc pig exhibit intrinsic differences in key aspects of the fibroblast response to injury compared with those from the Yorkshire pig, a same-species control that heals normally.

Race Does Not Predict Melanocyte Heterogeneous Responses to Dermal Fibroblast-Derived Mediators.

Introduction: Abnormal pigmentation following cutaneous injury causes significant patient distress and represents a barrier to recovery. Wound depth and patient characteristics influence scar pigmentation. However, we know little about the pathophysiology leading to hyperpigmentation in healed shallow wounds and hypopigmentation in deep dermal wound scars.

Genome-wide Association Study of Postburn Scarring Identifies a Novel Protective Variant.

Objective: To identify genetic variants associated with the severity of postburn hypertrophic scarring (HTS) using a genome-wide approach.

Background: Risk of severe postburn HTS is known to depend on race, but the genetic determinants of HTS are unknown.

Methods: We conducted a genome-wide association study (GWAS) in a prospective cohort of adults admitted with deep-partial-thickness burns from 2007 through 2014.

Race and Melanocortin 1 Receptor Polymorphism R163Q Are Associated with Post-Burn Hypertrophic Scarring: A Prospective Cohort Study.

The genetic determinants of post-burn hypertrophic scarring (HTS) are unknown, and melanocortin 1 receptor (MC1R) loss-of-function leads to fibrogenesis in experimental models. To examine the associations between self-identified race and MC1R single-nucleotide polymorphisms (SNPs) with severity of post-burn HTS, we conducted a prospective cohort study of burned adults admitted to our institution over 7 years. Subjects were evaluated using the Vancouver Scar Scale (VSS), asked to rate their itching, and genotyped for 8 MC1R SNPs.

Targeted metabolic profiling of wounds in diabetic and nondiabetic mice.

While cellular metabolism is known to regulate a number of key biological processes such as cell growth and proliferation, its role in wound healing is unknown. We hypothesized that cutaneous injury would induce significant metabolic changes and that the impaired wound healing seen in diabetes would be associated with a dysfunctional metabolic response to injury. We used a targeted metabolomics approach to characterize the metabolic profile of uninjured skin and full-thickness wounds at day 7 postinjury in nondiabetic (db/-) and diabetic (db/db) mice.

Genetic risk factors for hypertrophic scar development.

Hypertrophic scars (HTSs) occur in 30 to 72% patients after thermal injury. Risk factors include skin color, female sex, young age, burn site, and burn severity. Recent correlations between genetic variations and clinical conditions suggest that single-nucleotide polymorphisms (SNPs) may be associated with HTS formation.

Differentiation state determines neural effects on microvascular endothelial cells.

Growing evidence indicates that nerves and capillaries interact paracrinely in uninjured skin and cutaneous wounds. Although mature neurons are the predominant neural cell in the skin, neural progenitor cells have also been detected in uninjured adult skin. The aim of this study was to characterize differential paracrine effects of neural progenitor cells and mature sensory neurons on dermal microvascular endothelial cells.

Unsaturated fatty acids induce mesenchymal stem cells to increase secretion of angiogenic mediators.

Mesenchymal stem cells (MSC) represent emerging cell-based therapies for diabetes and associated complications. Ongoing clinical trials are using exogenous MSC to treat type 1 and 2 diabetes, cardiovascular disease and non-healing wounds due to diabetes. The majority of these trials are aimed at exploiting the ability of these multipotent mesenchymal stromal cells to release soluble mediators that reduce inflammation and promote both angiogenesis and cell survival at sites of tissue damage.

Spatial and temporal localization of the melanocortin 1 receptor and its ligand α-melanocyte-stimulating hormone during cutaneous wound repair.

Growing evidence indicates that the melanocortin 1 receptor (MC1R) and its ligand α-melanocyte-stimulating hormone (α-MSH) have other functions in the skin in addition to pigment production. Activation of the MC1R/α-MSH signaling pathway has been implicated in the regulation of both inflammation and extracellular matrix homeostasis. However, little is known about the role of MC1R/α-MSH signaling in the regulation of inflammatory and fibroproliferative responses to cutaneous injury.

Mesenchymal stem cells induce dermal fibroblast responses to injury.

Although bone marrow-derived mesenchymal stem cells have been shown to promote repair when applied to cutaneous wounds, the mechanism for this response remains to be determined. The aim of this study was to determine the effects of paracrine signaling from mesenchymal stem cells on dermal fibroblast responses to injury including proliferation, migration and expression of genes important in wound repair. Dermal fibroblasts were co-cultured with bone marrow-derived mesenchymal stem cells grown in inserts, which allowed for paracrine interactions without direct cell contact.

Elevated glucose and fatty acid levels impair substance P-induced dermal microvascular endothelial cell migration and proliferation in an agarose gel model system.

Substance P (SP), a sensory nerve derived neuropeptide, has been implicated in wound repair. Our hypothesis was that oxidative effects of elevated glucose and fatty acid levels as seen with diabetes mellitus inhibit SP-mediated endothelial cell directional migration and proliferation. Using a 2% agarose gel, immortalized human microvascular endothelial cells (HMEC-1) were plated into a 1.

Substance P enhances wound closure in nitric oxide synthase knockout mice.

Introduction: The neuropeptide, substance P (SP), up-regulates nitric oxide production (NO). The purpose of this study was to determine whether SP enhances response to cutaneous injury in nitric oxide synthase knockout (NOS null) mice.

Methods: We studied mice with targeted deletions of the 3 NOS genes, neuronal NOS, inducible NOS, or endothelial NOS.