Post-translational modification of proteins is a strategy widely used in biological systems. It expands the diversity of the proteome and allows for tailoring of both the function and localization of proteins within cells as well as the material properties of structural proteins and matrices. Despite their ubiquity in biology, with a few exceptions, the potential of post-translational modifications in biomaterials synthesis has remained largely untapped. As a proof of concept to demonstrate the feasibility of creating a genetically encoded biohybrid material through post-translational modification, we report here the generation of a family of three stimulus-responsive hybrid materials-fatty-acid-modified elastin-like polypeptides-using a one-pot recombinant expression and post-translational lipidation methodology. These hybrid biomaterials contain an amphiphilic domain, composed of a β-sheet-forming peptide that is post-translationally functionalized with a C alkyl chain, fused to a thermally responsive elastin-like polypeptide. They exhibit temperature-triggered hierarchical self-assembly across multiple length scales with varied structure and material properties that can be controlled at the sequence level.
Inspired by biohybrid molecules that are synthesized in Nature through post-translational modification (PTM), we have exploited a eukaryotic PTM to recombinantly synthesize lipid-polypeptide hybrid materials. By co-expressing yeast N-myristoyltransferase with an elastin-like polypeptide (ELP) fused to a short recognition sequence in E. coli, we show robust and high yield modification of the ELP with myristic acid. The ELP’s reversible phase behavior is retained upon myristoylation and can be tuned to span a 30–60 °C. Myristoylated ELPs provide a versatile platform for genetically pre-programming self-assembly into micelles of varied size and shape. Their lipid cores can be loaded with hydrophobic small molecules by passive diffusion. Encapsulated doxorubicin and paclitaxel exhibit cytotoxic effects on 4T1 and PC3-luc cells, respectively, with potencies similar to chemically conjugated counterparts, and longer plasma circulation than free drug upon intravenous injection in mice.
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Music therapy is gaining popularity as an intervention strategy for children with developmental disabilities, including autism spectrum disorder (ASD). This study was a pilot investigation of a classroom-based music-based intervention, Voices Together®, for improving communication skills in children with ASD and children with intellectual disabilities. Four local public elementary school special education classrooms, serving 5 children with a classification of autistic disorder and 32 children with intellectual disability without autism, were randomly selected to receive one of two levels of exposure to Voices Together music therapy: “long-term” (15 weeks beginning in January 2015 (Time 1), n = 14) or “short-term” (7 weeks beginning 7 weeks later in February (Time 2), n = 17). Using observational ratings, investigators reliably scored participants live in terms of their level of verbal responsiveness to prompts during three songs featured each week of the program. Both groups demonstrated increases in verbal responses over time; however, only the long-term group demonstrated significant within-group increases. Preliminary findings suggest that music therapy delivered in a classroom in 45-minute weekly sessions for 15 weeks can promote improvements in verbal responsiveness among individuals with autism and other developmental disabilities. Findings warrant further investigation into the efficacy of classroom-based music therapy programs.
PURPOSE. Cigarette smoking has been implicated in the pathogenesis of AMD. Integrin dysfunctions have been associated with AMD. Herein, we investigate the effect of risuteganib (RSG), an integrin regulator, on RPE cell injury induced by hydroquinone (HQ), an important oxidant in cigarette smoke. METHODS. Cultured human RPE cells were treated with HQ in the presence or absence of RSG. Cell death, mitochondrial respiration, reactive oxygen species production, and mitochondrial membrane potential were measured by flow cytometry, XFe24 analyzer, and fluorescence plate reader, respectively. Whole transcriptome analysis and gene expression were analyzed by Illumina RNA sequencing and quantitative PCR, respectively. F-actin aggregation was visualized with phalloidin. Levels of heme oxygenase-1, P38, and heat shock protein 27 proteins were measured by Western blot. RESULTS. HQ induced necrosis and apoptosis, decreased mitochondrial bioenergetics, increased reactive oxygen species levels, decreased mitochondrial membrane potential, increased F-actin aggregates, and induced phosphorylation of P38 and heat shock protein 27. HQ, but not RSG alone, induced substantial transcriptome changes that were regulated by RSG cotreatment. RSG cotreatment significantly protected against HQ-induced necrosis and apoptosis, prevented HQ-reduced mitochondrial bioenergetics, decreased HQ-induced reactive oxygen species production, improved HQ-disrupted mitochondrial membrane potential, reduced F-actin aggregates, decreased phosphorylation of P38 and heat shock protein 27, and further upregulated HQ-induced heme oxygenase-1 protein levels. CONCLUSIONS. RSG has no detectable adverse effects on healthy RPE cells, whereas RSG cotreatment protects against HQ-induced injury, mitochondrial dysfunction, and actin reorganization, suggesting a potential role for RSG therapy to treat retinal diseases such as AMD.
PURPOSE. Oxidative stress in retinal pigment epithelial (RPE) cells is associated with agerelated macular degeneration (AMD). Resveratrol exerts a range of protective biologic effects, but its mechanism(s) are not well understood. The aim of this study was to investigate how resveratrol could affect biologic pathways in oxidatively stressed RPE cells. METHODS. Cultured human RPE cells were treated with hydroquinone (HQ) in the presence or absence of resveratrol. Cell viability was determined with WST-1 reagent and trypan blue exclusion. Mitochondrial function was measured with the XFe24 Extracellular Flux Analyzer. Expression of heme oxygenase-1 (HO-1) and glutamate cysteine ligase catalytic subunit was evaluated by qPCR. Endoplasmic reticulum stress protein expression was measured by Western blot. Potential reactions between HQ and resveratrol were investigated using high-performance liquid chromatography mass spectrometry with resveratrol and additional oxidants for comparison. RESULTS. RPE cells treated with the combination of resveratrol and HQ had significantly increased cell viability and improved mitochondrial function when compared with HQtreated cells alone. Resveratrol in combination with HQ significantly upregulated HO-1 mRNA expression above that of HQ-treated cells alone. Resveratrol in combination with HQ upregulated C/EBP homologous protein and spliced X-box binding protein 1. Additionally, new compounds were formed from resveratrol and HQ coincubation. CONCLUSIONS. Resveratrol can ameliorate HQ-induced toxicity in RPE cells through improved mitochondrial bioenergetics, upregulated antioxidant genes, stimulated unfolded protein response, and direct oxidant interaction. This study provides insight into pathways through which resveratrol can protect RPE cells from oxidative damage, a factor thought to contribute to AMD pathogenesis.
Variants in the PAX6 gene have been associated with ophthalmologic, neurologic, and pancreatic differences. We report on a proband, mother, and affected brother who presented with congenital cataracts and glaucoma at a young age. Non-ocular findings are also reported among these family members. After a congenital cataracts next generation sequencing (NGS) gene panel was found to be non-diagnostic in 2016, a more expanded panel in 2020 revealed a novel variant: c.178T>A; p.Tyr60Asn in exon 6 of the PAX6 gene in the proband. The variant is also present in the affected mother and affected brother; it is absent in an unaffected brother. The clinical findings of these three relatives, in conjunction with their genetic testing and the associated PAX6 features reported in the literature, suggest that this novel familial variant may be an underlying etiology for these individuals' ophthalmologic, pancreatic, and olfactory symptoms.
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