FATP5 Is Indispensable for the Growth of Intrahepatic Cholangiocarcinoma.

Altered lipid metabolism is a common hallmark of various cancers, including intrahepatic cholangiocarcinoma (ICC), a highly lethal carcinoma that lacks effective treatment options. To elucidate the lipid metabolism changes in ICC, we coupled the expression of the firefly luciferase gene (FFL) to AKT1 (AKT-FFL) via an IRES linker, and then hydrodynamically injected mice with AKT-FFL and Notch1 intracellular cytoplasmic domain (NICD) to establish a luciferase-positive ICC model. This model not only enabled us to monitor and quantify tumor growth by injecting the mice with luciferin, but also allowed us to assess the fatty acid uptake rate by injecting the mice with free fatty acid luciferin (FFA-Luc). The ICC model exhibited robust uptake of exogenous fatty acids compared with the HCC model induced by AKT-FFL/ neuroblastoma Ras (Ras). Lipidomics analysis showed a dramatically higher level of fatty acid in ICC, further supporting the increased fatty acids uptake. Mechanistic studies identified FATP5 as the predominant mediator of fatty acid uptake required for ICC growth using Fatp5 knockout mice and AAV-based shRNA silencing of Fatp5. Our study discovered a novel therapeutic target for the treatment of ICC and shed light on the contributions of lipid metabolism to ICC development. IMPLICATIONS: This study provides the first in vivo evidence that FATP5 is a potential therapeutic target for treating ICC.

Associations Between ADHD Symptoms and Maternal and Birth Outcomes: An Exploratory Analysis in a Multi-Country Cohort of Expectant Mothers.

OBJECTIVE: ADHD symptoms can adversely impact functioning in a range of domains relevant for maternal well-being and fetal development; however, there has been almost no research examining their impact during pregnancy. We aimed to address this gap. METHOD: We used data (n = 1,204) from a longitudinal birth cohort study spanning eight countries to address this gap. RESULTS: ADHD symptoms in the third trimester of pregnancy were associated with lower social support from family (b = -0.16, p = .031), friends (b = -0.16, p = .024), and significant others (b = -0.09, p = .001); higher stress (b = 0.34, p < .001) and depressive symptoms (b = 0.31, p < .001), and increased likelihood of an unwanted pregnancy (b = 0.30, p = .009). Significant associations with tobacco use (b = 0.36, p = .023) and premature birth (b = 0.35, p = .007) did not survive correction for multiple comparisons and there were no significant associations with alcohol use, low birth weight, or unplanned pregnancy. CONCLUSION: Results suggest that women with ADHD symptoms could benefit from earlier, more regular screening for mental health difficulties and greater mental health support during pregnancy.

Patterns of adverse childhood experiences and associations with prenatal substance use and poor infant outcomes in a multi-country cohort of mothers: a latent class analysis.

BACKGROUND: This paper enumerates and characterizes latent classes of adverse childhood experiences and investigates how they relate to prenatal substance use (i.e., smoking, alcohol, and other drugs) and poor infant outcomes (i.e., infant prematurity and low birthweight) across eight low- and middle-income countries (LMICs). METHODS: A total of 1189 mother-infant dyads from the Evidence for Better Lives Study cohort were recruited. Latent class analysis using the Bolck, Croon, and Hagenaars (BCH) 3-step method with auxiliary multilevel logistic regressions was performed. RESULTS: Three high-risk classes and one low-risk class emerged: (1) highly maltreated (7%, n = 89), (2) emotionally and physically abused with intra-familial violence exposure (13%, n = 152), (3), emotionally abused (40%, n = 474), and (4) low household dysfunction and abuse (40%, n = 474). Pairwise comparisons between classes indicate higher probabilities of prenatal drug use in the highly maltreated and emotionally abused classes compared with the low household dysfunction and abuse class. Additionally, the emotionally and physically abused with intra-familial violence exposure class had higher probability of low birthweight than the three remaining classes. CONCLUSION: Our results highlight the multifaceted nature of ACEs and underline the potential importance of exposure to childhood adversities on behaviors and outcomes in the perinatal period. This can inform the design of antenatal support to better address these challenges.

Aging alters the metabolic flux signature of the ER-unfolded protein response in vivo in mice.

Age is a risk factor for numerous diseases, including neurodegenerative diseases, cancers, and diabetes. Loss of protein homeostasis is a central hallmark of aging. Activation of the endoplasmic reticulum unfolded protein response (UPRER ) includes changes in protein translation and membrane lipid synthesis. Using stable isotope labeling, a flux "signature" of the UPRER in vivo in mouse liver was developed by inducing ER stress with tunicamycin and measuring rates of both proteome-wide translation and de novo lipogenesis. Several changes in protein synthesis across ontologies were noted with age, including a more dramatic suppression of translation under ER stress in aged mice as compared with young mice. Binding immunoglobulin protein (BiP) synthesis rates and mRNA levels were increased more in aged than young mice. De novo lipogenesis rates decreased under ER stress conditions in aged mice, including both triglyceride and phospholipid fractions. In young mice, a significant reduction was seen only in the triglyceride fraction. These data indicate that aged mice have an exaggerated metabolic flux response to ER stress, which may indicate that aging renders the UPRER less effective in resolving proteotoxic stress.

Application of cognitive screening guidelines by health care providers in diabetes care: A cross-sectional descriptive study.

RATIONALE, AIMS, AND OBJECTIVES: The risk of cognitive dysfunction is higher in people with diabetes than in the general population, and approximately 50% of those with diabetes will develop cognitive impairments as they age. Screening for cognitive dysfunction in people with diabetes can help identify both pathology and those who are at risk for higher health care utilization, but we do not know how health care providers implement cognitive screening recommendations in this population. In this study, we examined health care providers' knowledge of those recommendations and their application of them, as well as factors associated with guideline use. METHODS: This study used a cross-sectional, descriptive correlational design with a convenience sample. All data were collected with a 20-question online survey sent to advanced practice nurses (APNs), medical doctors/doctor of osteopathic medicines (MDs/DOs), and physician assistants (PAs) in Central Texas. RESULTS: One-hundred eighty-one health care providers responded. Participants most frequently said they were "moderately familiar" with guidelines for cognitive impairment screening (60.9%). Twenty-three per cent of physicians, 37.4% of APNs, and 8.3% of PAs indicated that they incorporated routine screening into daily practice. However, 64% did not use standardized tools to assess cognitive function. The most common clinical tasks related to cognitive screening were referral for more in-depth cognitive screening (44%) and education of families regarding cognitive problems (29%). Lack of time was the most common barrier to screening (57.7%). CONCLUSIONS: Most respondents believed that there was a good rationale for assessing cognitive function in people with diabetes. However, despite some familiarity with guidelines for cognitive function screening, most respondents did not use standardized assessment tools. The results indicate variability in clinical practice regarding assessment and practices, such that there may be some variability in outcomes for patients.

Non-technical skills and gastrointestinal endoscopy: a review of the literature.

BACKGROUND: Non-technical skills (NTS) have gained increasing recognition in recent years for their role in safe, effective team performance in healthcare. Gastrointestinal endoscopy is a procedure-based specialty with rapidly advancing technology, significant operational pressures and rapidly changing 'teams of experts'. However, to date there has been little focus on the effect of NTS in this field. OBJECTIVES: This review aims to examine the existing literature on NTS in gastrointestinal endoscopy and identify areas for further research. METHOD: A systematic search of MEDLINE, Embase, Cochrane Library, PsychINFO, CINAHL Plus and PubMed databases was performed using search terms Non-Technical Skills, Team Performance or Team Skills, and Endoscopy, Colonoscopy, OGD, Gastroscopy, Endoscopic Retrograde Cholangio-Pancreatography or Endoscopic Ultrasound. RESULTS: Eighteen relevant publications were found. NTS are deemed an essential component of practice, but so far there is little evidence of their integration into training or competency assessment. Those studies examining the effects of NTS and team training in endoscopy are small and have variable outcome measures with limited evidence of improvement in skills or clinical outcomes. NTS assessment in endoscopy is in its early phases with a few tools in development. CONCLUSIONS: The current literature on NTS in gastrointestinal endoscopy is limited. NTS, however, are deemed an essential component of practice, with potential positive effects on team performance and clinical outcomes. A validated reliable tool would enable evaluation of training and investigation into the effects of NTS on outcomes. There is a clear need for further research in this field.

Impairment of early fracture healing by skeletal muscle trauma is restored by FK506.

BACKGROUND: Heightened local inflammation due to muscle trauma or disease is associated with impaired bone regeneration. METHODS: We hypothesized that FK506, an FDA approved immunomodulatory compound with neurotrophic and osteogenic effects, will rescue the early phase of fracture healing which is impaired by concomitant muscle trauma in male (~4 months old) Lewis rats. FK506 (1 mg/kg; i.p.) or saline was administered systemically for 14 days after an endogenously healing tibia osteotomy was created and fixed with an intermedullary pin, and the overlying tibialis anterior (TA) muscle was either left uninjured or incurred volumetric muscle loss injury (6 mm full thickness biopsy from middle third of the muscle). RESULTS: The salient observations of this study were that 1) concomitant TA muscle trauma impaired recovery of tibia mechanical properties 28 days post-injury, 2) FK506 administration rescued the recovery of tibia mechanical properties in the presence of concomitant TA muscle trauma but did not augment mechanical recovery of an isolated osteotomy (no muscle trauma), 3) T lymphocytes and macrophage presence within the traumatized musculature were heightened by trauma and attenuated by FK506 3 days post-injury, and 4) T lymphocyte but not macrophage presence within the fracture callus were attenuated by FK506 at 14 days post-injury. FK506 did not improve TA muscle isometric torque production CONCLUSION: Collectively, these findings support the administration of FK506 to ameliorate healing of fractures with severe muscle trauma comorbidity. The results suggest one potential mechanism of action is a reduction in local T lymphocytes within the injured musculoskeletal tissue, though other mechanisms to include direct osteogenic effects of FK506 require further investigation.

Achieving Acetylcholine Receptor Clustering in Tissue-Engineered Skeletal Muscle Constructs In vitro through a Materials-Directed Agrin Delivery Approach.

Volumetric muscle loss (VML) can result from trauma, infection, congenital anomalies, or surgery, and produce permanent functional and cosmetic deficits. There are no effective treatment options for VML injuries, and recent advances toward development of muscle constructs lack the ability to achieve innervation necessary for long-term function. We sought to develop a proof-of-concept biomaterial construct that could achieve acetylcholine receptor (AChR) clustering on muscle-derived cells (MDCs) in vitro. The approach consisted of the presentation of neural (Z+) agrin from the surface of microspheres embedded with a fibrin hydrogel to muscle cells (C2C12 cell line or primary rat MDCs). AChR clustering was spatially restricted to areas of cell (C2C12)-microsphere contact when the microspheres were delivered in suspension or when they were incorporated into a thin (2D) fibrin hydrogel. AChR clusters were observed from 16 to 72 h after treatment when Z+ agrin was adsorbed to the microspheres, and for greater than 120 h when agrin was covalently coupled to the microspheres. Little to no AChR clustering was observed when agrin-coated microspheres were delivered from specially designed 3D fibrin constructs. However, cyclic stretch in combination with agrin-presenting microspheres led to dramatic enhancement of AChR clustering in cells cultured on these 3D fibrin constructs, suggesting a synergistic effect between mechanical strain and agrin stimulation of AChR clustering in vitro. These studies highlight a strategy for maintaining a physiological phenotype characterized by motor endplates of muscle cells used in tissue engineering strategies for muscle regeneration. As such, these observations may provide an important first step toward improving function of tissue-engineered constructs for treatment of VML injuries.

A transient cell-shielding method for viable MSC delivery within hydrophobic scaffolds polymerized in situ.

Cell-based therapies have emerged as promising approaches for regenerative medicine. Hydrophobic poly(ester urethane)s offer the advantages of robust mechanical properties, cell attachment without the use of peptides, and controlled degradation by oxidative and hydrolytic mechanisms. However, the application of injectable hydrophobic polymers to cell delivery is limited by the challenges of protecting cells from reaction products and creating a macroporous architecture post-cure. We designed injectable carriers for cell delivery derived from reactive, hydrophobic polyisocyanate and polyester triol precursors. To overcome cell death caused by reaction products from in situ polymerization, we encapsulated bone marrow-derived stem cells (BMSCs) in fastdegrading, oxidized alginate beads prior to mixing with the hydrophobic precursors. Cells survived the polymerization at >70% viability, and rapid dissolution of oxidized alginate beads after the scaffold cured created interconnected macropores that facilitated cellular adhesion to the scaffold in vitro. Applying this injectable system to deliver BMSCs to rat excisional skin wounds showed that the scaffolds supported survival of transplanted cells and infiltration of host cells, which improved new tissue formation compared to both implanted, pre-formed scaffolds seeded with cells and acellular controls. Our design is the first to enable injectable delivery of settable, hydrophobic scaffolds where cell encapsulation provides a mechanism for both temporary cytoprotection during polymerization and rapid formation of macropores post-polymerization. This simple approach provides potential advantages for cell delivery relative to hydrogel technologies, which have weaker mechanical properties and require incorporation of peptides to achieve cell adhesion and degradability.

Soluble factors from biofilms of wound pathogens modulate human bone marrow-derived stromal cell differentiation, migration, angiogenesis, and cytokine secretion.

BACKGROUND: Chronic, non-healing wounds are often characterized by the persistence of bacteria within biofilms - aggregations of cells encased within a self-produced polysaccharide matrix. Biofilm bacteria exhibit unique characteristics from planktonic, or culture-grown, bacterial phenotype, including diminished responses to antimicrobial therapy and persistence against host immune responses. Mesenchymal stromal cells (MSCs) are host cells characterized by their multifunctional ability to undergo differentiation into multiple cell types and modulation of host-immune responses by secreting factors that promote wound healing. While these characteristics make MSCs an attractive therapeutic for wounds, these pro-healing activities may be differentially influenced in the context of an infection (i.e., biofilm related infections) within chronic wounds. Herein, we evaluated the effect of soluble factors derived from biofilms of clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa on the viability, differentiation, and paracrine activity of human MSCs to evaluate the influence of biofilms on MSC activity in vitro. RESULTS: Exposure of MSCs to biofilm-conditioned medias of S. aureus and P. aeruginosa resulted in reductions in cell viability, in part due to activation of apoptosis. Similarly, exposure to soluble factors from biofilms was also observed to diminish the migration ability of cells and to hinder multi-lineage differentiation of MSCs. In contrast to these findings, exposure of MSCs to soluble factors from biofilms resulted in significant increases in the release of paracrine factors involved in inflammation and wound healing. CONCLUSIONS: Collectively, these findings demonstrate that factors produced by biofilms can negatively impact the intrinsic properties of MSCs, in particular limiting the migratory and differentiation capacity of MSCs. Consequently, these studies suggest use/application of stem-cell therapies in the context of infection may have a limited therapeutic effect.

Screening and brief intervention for substance misuse: Does it reduce aggression and HIV-related risk behaviours?

PURPOSE: To explore whether reducing substance misuse through a brief motivational intervention also reduces aggression and HIV risk behaviours. METHODS: Participants were enrolled in a randomized controlled trial in primary care if they screened positive for substance misuse. Substance misuse was assessed using the Alcohol, Smoking and Substance Involvement Screening Test; aggression, using a modified version of the Explicit Aggression Scale; and HIV risk, through a count of common risk behaviours. The intervention was received on the day of the baseline interview, with a 3-month follow-up. RESULTS: Participants who received the intervention were significantly more likely to reduce their alcohol use than those who did not; no effect was identified for other substances. In addition, participants who reduced substance misuse (whether as an effect of the intervention or not) also reduced aggression but not HIV risk behaviours. CONCLUSIONS: Reducing substance misuse through any means reduces aggression; other interventions are needed for HIV risk reduction.

Comparison of Decontamination Methods for Human Skin Grafts.

Skin grafts intended for autologous transplant may be dropped on the operating room floor during handling. The authors examined optimal procedures for decontaminating tissue intended for burn surgery. Porcine skin (5 × 5 cm sections) harvested from expired animals using standard procedures was inoculated with either 10(6) CFU/ml Staphylococcus aureus or Klebsiella pneumoniae. Decontaminating strategies were compared: 10% povidone iodine, 0.04% chlorhexidine, or 50 U/ml bacitracin for injection, and mechanical agitation using normal saline or sterile water; each agent was applied for 60 seconds. Each skin section was blended and plated on agar for bacterial enumeration using the spread plate method. Tissue viability was evaluated in parallel using a cell viability reagent, along with a control (heat at 200 °C for 5 min). Bacterial counts were log transformed; one-way ANOVA with Tukey-Kramer HSD analysis were performed. Concentration of organisms <10(5) CFU/g was considered clinically insignificant colonization. Eight donors provided 21 S. aureus and six K. pneumoniae samples. After exposure, mean organism concentration (CFU/g) was <10(5) for povidone iodine (S. aureus 2.83 × 10(4); K. pneumoniae 1.85 × 10(4)), chlorhexidine (S. aureus 4.52 × 10(4); K. pneumoniae 1.77 × 10(4)), and normal saline (K. pneumoniae 8.76 × 10(4)) treated groups. After log transform, only povidone iodine and chlorhexidine were found to be different from control in both groups. Viability was decreased in the positive control group, but not in treatment groups. Agents routinely used for surgical skin prep (povidone iodine and chlorhexidine), reduced both Gram-positive and Gram-negative contamination in tissue intended for skin grafting procedures. Antiseptic treatments did not impair the cellular viability of porcine skin.

Adapting a blended motivational interviewing and problem-solving intervention to address risky substance use amongst South Africans.

The purpose of this study was to examine the acceptability and initial substance use outcomes of a blended motivational interviewing (MI) and problem-solving therapy (PST) intervention, delivered by peer counsellors. Twenty people who scored at risk for substance use according to the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) received a five session blended MI-PST intervention and were assessed at baseline and at three months. An open-ended semi-structured interview, designed to identify possible factors that may hinder or promote the acceptability of the intervention was also conducted. Fifteen participants completed the intervention and the three-month follow-up. According to ASSIST scores, participants significantly reduced their substance use (p > 0.001) at the three-month follow-up. Randomized controlled trials are needed to evaluate the effect of this intervention more rigorously.

Functions of FUS/TLS from DNA repair to stress response: implications for ALS.

Fused in sarcoma/translocated in liposarcoma (FUS/TLS or FUS) is a multifunctional DNA-/RNA-binding protein that is involved in a variety of cellular functions including transcription, protein translation, RNA splicing, and transport. FUS was initially identified as a fusion oncoprotein, and thus, the early literature focused on the role of FUS in cancer. With the recent discoveries revealing the role of FUS in neurodegenerative diseases, namely amyotrophic lateral sclerosis and frontotemporal lobar degeneration, there has been a renewed interest in elucidating the normal functions of FUS. It is not clear which, if any, endogenous functions of FUS are involved in disease pathogenesis. Here, we review what is currently known regarding the normal functions of FUS with an emphasis on DNA damage repair, RNA processing, and cellular stress response. Further, we discuss how ALS-causing mutations can potentially alter the role of FUS in these pathways, thereby contributing to disease pathogenesis.

Effectiveness of nurse-practitioner-delivered brief motivational intervention for young adult alcohol and drug use in primary care in South Africa: a randomized clinical trial.

AIMS: To assess the effectiveness of brief motivational intervention for alcohol and drug use in young adult primary care patients in a low-income population and country. METHODS: A randomized controlled trial in a public-sector clinic in Delft, a township in the Western Cape, South Africa recruited 403 patients who were randomized to either single-session, nurse practitioner-delivered Brief Motivational Intervention plus referral list or usual care plus referral list, and followed up at 3 months. RESULTS: Although rates of at-risk alcohol use and drug use did not differ by treatment arm at follow-up, patients assigned to the Brief Motivational Intervention had significantly reduced scores on ASSIST (Alcohol, Smoking and Substance Involvement Screening Test) for alcohol-the most prevalent substance. CONCLUSION: Brief Motivational Intervention may be effective at reducing at-risk alcohol use in the short term among low-income young adult primary care patients; additional research is needed to examine long-term outcomes.

Characterization and multilineage potential of cells derived from isolated microvascular fragments.

BACKGROUND: A number of therapies are being developed that use microvessels isolated from adipose tissue (microvascular fragments [MVFs]) to improve tissue perfusion and implant survival. Because it has been demonstrated that stem cells are associated with microvessels, the purpose of these studies was to gain further insight into the stem cells associated with MVFs to better understand their therapeutic potential. MATERIALS AND METHODS: Cells derived from MVF explants were compared with adipose-derived stem cells (ASCs) based on the expression of cell surface proteins for mesenchymal stem cells and their capacity for angiogenic, neurogenic, adipogenic, and osteogenic differentiation. RESULTS: The expression of cell surface proteins for mesenchymal stem cell markers was similar between MVF-derived cells and ASCs; however, the increase in markers consistent with endothelial cells and pericytes was accompanied by an improved ability to form capillary-like networks when cultured on matrigel. MVF-derived cells had increased neuregulin, leptin, and osteopontin expression compared with ASCs when exposed to neurogenic, adipogenic, and osteogenic induction media, respectively. CONCLUSIONS: The stem cell functionality of cells derived from MVFs is retained after their isolation. This helps to explain the ability of MVFs to improve tissue perfusion and has implications for the use of MVFs as a means to deliver stem cells within their niche.

Asynchronous inflammation and myogenic cell migration limit muscle tissue regeneration mediated by a cellular scaffolds.

Volumetric muscle loss (VML) following orthopaedic trauma results in chronic loss of strength and can contribute to disability. Tissue engineering and regenerative medicine approaches to regenerate the lost skeletal muscle and improve functional outcomes are currently under development. At the forefront of these efforts, decellularized extracellular matrices (ECMs) have reached clinical testing and provide the foundation for other approaches that include stem/progenitor cell delivery. ECMs have been demonstrated to possess many qualities to initiate regeneration, to include stem cell chemotaxis and pro-regenerative macrophage polarization. However, the majority of observations indicate that ECM-repair of VML does not promote appreciable muscle fiber regeneration. In a recent study, ECM-repair of VML was compared to classical muscle fiber regeneration (Garg et al., 2014, Cell & Tissue Research) mediated by autologous minced grafts. The most salient findings of this study were: 1) Satellite cells did not migrate into the scaffold beyond ~0.5 mm from the remaining host tissue, although other migratory stem cells (Sca-1+) were observed throughout the scaffold;2) Macrophage migration to the scaffold was over two-times that observed with muscle grafts, but they appeared to be less active, as gene expression of pro- and anti-inflammatory cytokines (TNF-α, IL-12, IL-4, IL-10, VEGF, and TGF-ß1) was significantly reduced in scaffold-repaired muscles; And, 3) scaffolds did not promote appreciable muscle fiber regeneration. Collectively, these data suggest that the events following ECM transplantation in VML are either incongruous or asynchronous with classical muscle fiber regeneration.

Amyotrophic lateral sclerosis-linked FUS/TLS alters stress granule assembly and dynamics.

BACKGROUND: Amyotrophic lateral sclerosis (ALS)-linked fused in sarcoma/translocated in liposarcoma (FUS/TLS or FUS) is concentrated within cytoplasmic stress granules under conditions of induced stress. Since only the mutants, but not the endogenous wild-type FUS, are associated with stress granules under most of the stress conditions reported to date, the relationship between FUS and stress granules represents a mutant-specific phenotype and thus may be of significance in mutant-induced pathogenesis. While the association of mutant-FUS with stress granules is well established, the effect of the mutant protein on stress granules has not been examined. Here we investigated the effect of mutant-FUS on stress granule formation and dynamics under conditions of oxidative stress. RESULTS: We found that expression of mutant-FUS delays the assembly of stress granules. However, once stress granules containing mutant-FUS are formed, they are more dynamic, larger and more abundant compared to stress granules lacking FUS. Once stress is removed, stress granules disassemble more rapidly in cells expressing mutant-FUS. These effects directly correlate with the degree of mutant-FUS cytoplasmic localization, which is induced by mutations in the nuclear localization signal of the protein. We also determine that the RGG domains within FUS play a key role in its association to stress granules. While there has been speculation that arginine methylation within these RGG domains modulates the incorporation of FUS into stress granules, our results demonstrate that this post-translational modification is not involved. CONCLUSIONS: Our results indicate that mutant-FUS alters the dynamic properties of stress granules, which is consistent with a gain-of-toxic mechanism for mutant-FUS in stress granule assembly and cellular stress response.

FUS/TLS assembles into stress granules and is a prosurvival factor during hyperosmolar stress.

FUsed in Sarcoma/Translocated in LipoSarcoma (FUS/TLS or FUS) has been linked to several biological processes involving DNA and RNA processing, and has been associated with multiple diseases, including myxoid liposarcoma and amyotrophic lateral sclerosis (ALS). ALS-associated mutations cause FUS to associate with stalled translational complexes called stress granules under conditions of stress. However, little is known regarding the normal role of endogenous (non-disease linked) FUS in cellular stress response. Here, we demonstrate that endogenous FUS exerts a robust response to hyperosmolar stress induced by sorbitol. Hyperosmolar stress causes an immediate re-distribution of nuclear FUS to the cytoplasm, where it incorporates into stress granules. The redistribution of FUS to the cytoplasm is modulated by methyltransferase activity, whereas the inhibition of methyltransferase activity does not affect the incorporation of FUS into stress granules. The response to hyperosmolar stress is specific, since endogenous FUS does not redistribute to the cytoplasm in response to sodium arsenite, hydrogen peroxide, thapsigargin, or heat shock, all of which induce stress granule assembly. Intriguingly, cells with reduced expression of FUS exhibit a loss of cell viability in response to sorbitol, indicating a prosurvival role for endogenous FUS in the cellular response to hyperosmolar stress.

The promotion of a functional fibrosis in skeletal muscle with volumetric muscle loss injury following the transplantation of muscle-ECM.

Tissue engineering strategies that primarily use biological extracellular matrices (ECMs) with or without the inclusion of a stem or progenitor cell source are under development for the treatment of trauma resulting in the loss of a large volume of skeletal muscle (i.e., volumetric muscle loss; VML). The explicit goal is to restore functional capacity to the injured tissue by promoting generation of muscle fibers. In the current study, a syngeneic muscle-derived ECM (mECM) was transplanted in a rat tibialis anterior (TA) muscle VML model. Instead of muscle fiber generation a large fibrotic mass was produced by mECM transplantation out to six months post-injury. Surprisingly, recovery of one-third of the original functional deficit was still achieved by two months post-injury following mECM transplantation. These counterintuitive findings may be due, at least in part, to the ability of mECM to attenuate muscle damage in the remaining muscle as compared to non-repaired muscle. These findings point to a novel role of biological ECMs for the treatment of VML, wherein the remaining muscle mass is protected from prolonged overload injury.