Electrochemical Aptamer-Based Biosensor for Detecting Pap31, a Biomarker for Carrion's Disease.

Carrion's disease, caused by infection with the bacterium (), is effectively treated with antibiotics, but reaches fatality rates of ~90% if untreated. Current diagnostic methods are limited, insufficiently sensitive, or require laboratory technology unavailable in endemic areas. Electrochemical aptamer-based (E-AB) biosensors provide a potential solution for this unmet need, as these biosensors are portable, sensitive, and can rapidly report the detection of small molecule targets.

Macrophages derived from human induced pluripotent stem cells (iPSCs) serve as a high-fidelity cellular model for investigating HIV-1, dengue, and influenza viruses.

Unlabelled: Macrophages are important target cells for diverse viruses and thus represent a valuable system for studying virus biology. Isolation of primary human macrophages is done by culture of dissociated tissues or from differentiated blood monocytes, but these methods are both time consuming and result in low numbers of recovered macrophages. Here, we explore whether macrophages derived from human induced pluripotent stem cells (iPSCs)-which proliferate indefinitely and potentially provide unlimited starting material-could serve as a faithful model system for studying virus biology.

Rapid and Quantitative Detection of Lung Cancer Biomarker ENOX2 Using a Novel Aptamer in an Electrochemical DNA-Based (E-DNA) Biosensor.

To overcome early cancer detection challenges, diagnostic tools enabling more sensitive, rapid, and noninvasive detection are necessary. An attractive cancer target for diagnostic blood tests is human Ecto-NOX disulfide-thiol exchanger 2 (ENOX2), expressed in most human cancer types and regularly shed into blood sera. Here, we developed an electrochemical DNA-based (E-DNA) biosensor that rapidly detects physiologically relevant levels of ENOX2.

Differentiating Human Pluripotent Stem Cells to Cardiomyocytes Using Purified Extracellular Matrix Proteins.

Human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) can be differentiated into cardiomyocytes (hESC-CMs and iPSC-CMs, respectively), which hold great promise for cardiac regenerative medicine and disease modeling efforts. However, the most widely employed differentiation protocols require undefined substrates that are derived from xenogeneic (animal) products, contaminating resultant hESC- and iPSC-CM cultures with xenogeneic proteins and limiting their clinical applicability. Additionally, typical hESC- and iPSC-CM protocols produce CMs that are significantly contaminated by non-CMs and that are immature, requiring lengthy maturation procedures.

Electrochemical DNA Biosensor That Detects Early Celiac Disease Autoantibodies.

Although it is estimated that more than one million Americans have celiac disease (CD), it remains challenging to diagnose. CD, an autoimmune and inflammatory response following the ingestion of gluten-containing foods, has symptoms overlapping with other diseases and requires invasive diagnostics. The gold standard for CD diagnosis involves serologic blood tests followed by invasive confirmatory biopsies.

Allele-specific proximal promoter hypomethylation of the telomerase reverse transcriptase gene (TERT) associates with TERT expression in multiple cancers.

Telomerase reverse transcriptase (TERT) is pathologically expressed in the vast majority of human cancers, but the epigenetic regulation of its expression is only beginning to be understood. In particular, the active TERT gene in cancer cells has been characterized as having a hypermethylated CpG island, opposite to the general association of DNA methylation with gene repression. Here, we analyzed TERT promoter CpG methylation in 833 human cancer cell lines representing 23 different tissue types and found hypermethylation of the upstream portion of the CpG island and more conserved hypomethylation of a region including the proximal TERT promoter and exon 1.

Danon Disease-Associated LAMP-2 Deficiency Drives Metabolic Signature Indicative of Mitochondrial Aging and Fibrosis in Cardiac Tissue and hiPSC-Derived Cardiomyocytes.

Danon disease is a severe X-linked disorder caused by deficiency of the lysosome-associated membrane protein-2 (LAMP-2). Clinical manifestations are phenotypically diverse and consist of hypertrophic and dilated cardiomyopathies, skeletal myopathy, retinopathy, and intellectual dysfunction. Here, we investigated the metabolic landscape of Danon disease by applying a multi-omics approach and combined structural and functional readouts provided by Raman and atomic force microscopy.

Genetic Risk of Arrhythmic Phenotypes in Patients With Dilated Cardiomyopathy.

Background: Genotype-phenotype correlations in dilated cardiomyopathy (DCM) and, in particular, the effects of gene variants on clinical outcomes remain poorly understood.

Objectives: The purpose of this study was to investigate the prognostic role of genetic variant carrier status in a large cohort of DCM patients.

Methods: A total of 487 DCM patients were analyzed by next-generation sequencing and categorized the disease genes into functional gene groups.

Single-cell imaging reveals unexpected heterogeneity of telomerase reverse transcriptase expression across human cancer cell lines.

Telomerase is pathologically reactivated in most human cancers, where it maintains chromosomal telomeres and allows immortalization. Because telomerase reverse transcriptase (TERT) is usually the limiting component for telomerase activation, numerous studies have measured TERT mRNA levels in populations of cells or in tissues. In comparison, little is known about TERT expression at the single-cell and single-molecule level.

Gold Nanoparticle-Functionalized Reverse Thermal Gel for Tissue Engineering Applications.

Utilizing polymers in cardiac tissue engineering holds promise for restoring function to the heart following myocardial infarction, which is associated with grave morbidity and mortality. To properly mimic native cardiac tissue, materials must not only support cardiac cell growth but also have inherent conductive properties. Here, we present an injectable reverse thermal gel (RTG)-based cardiac cell scaffold system that is both biocompatible and conductive.

Filamin C Truncation Mutations Are Associated With Arrhythmogenic Dilated Cardiomyopathy and Changes in the Cell-Cell Adhesion Structures.

Objectives: The purpose of this study was to assess the phenotype of Filamin C (FLNC) truncating variants in dilated cardiomyopathy (DCM) and understand the mechanism leading to an arrhythmogenic phenotype.

Background: Mutations in FLNC are known to lead to skeletal myopathies, which may have an associated cardiac component. Recently, the clinical spectrum of FLNC mutations has been recognized to include a cardiac-restricted presentation in the absence of skeletal muscle involvement.

Injectable Hydrogels for Cardiac Tissue Engineering.

In light of the limited efficacy of current treatments for cardiac regeneration, tissue engineering approaches have been explored for their potential to provide mechanical support to injured cardiac tissues, deliver cardio-protective molecules, and improve cell-based therapeutic techniques. Injectable hydrogels are a particularly appealing system as they hold promise as a minimally invasive therapeutic approach. Moreover, injectable acellular alginate-based hydrogels have been tested clinically in patients with myocardial infarction (MI) and show preservation of the left ventricular (LV) indices and left ventricular ejection fraction (LVEF).

Injectable Carbon Nanotube-Functionalized Reverse Thermal Gel Promotes Cardiomyocytes Survival and Maturation.

The ability of the adult heart to regenerate cardiomyocytes (CMs) lost after injury is limited, generating interest in developing efficient cell-based transplantation therapies. Rigid carbon nanotubes (CNTs) scaffolds have been used to improve CMs viability, proliferation, and maturation, but they require undesirable invasive surgeries for implantation. To overcome this limitation, we developed an injectable reverse thermal gel (RTG) functionalized with CNTs (RTG-CNT) that transitions from a solution at room temperature to a three-dimensional (3D) gel-based matrix shortly after reaching body temperature.

Impaired mitophagy facilitates mitochondrial damage in Danon disease.

Rationale: Lysosomal associated membrane protein type-2 (LAMP-2) is a highly conserved, ubiquitous protein that is critical for autophagic flux. Loss of function mutations in the LAMP-2 gene cause Danon disease, a rare X-linked disorder characterized by developmental delay, skeletal muscle weakness, and severe cardiomyopathy. We previously found that human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) from Danon patients exhibited significant mitochondrial oxidative stress and apoptosis.

Electrochemical Aptamer Scaffold Biosensors for Detection of Botulism and Ricin Proteins.

Electrochemical DNA (E-DNA) biosensors enable the detection and quantification of a variety of molecular targets, including oligonucleotides, small molecules, heavy metals, antibodies, and proteins. Here we describe the design, electrode preparation and sensor attachment, and voltammetry conditions needed to generate and perform measurements using E-DNA biosensors against two protein targets, the biological toxins ricin and botulinum neurotoxin. This method can be applied to generate E-DNA biosensors for the detection of many other protein targets, with potential advantages over other systems including sensitive detection limits typically in the nanomolar range, real-time monitoring, and reusable biosensors.

Gene Splice Mutations Cause Dilated Cardiomyopathy.

Objective: To identify novel dilated cardiomyopathy (DCM) causing genes, and to elucidate the pathological mechanism leading to DCM by utilizing zebrafish as a model organism.

Background: DCM, a major cause of heart failure, is frequently familial and caused by a genetic defect. However, only 50% of DCM cases can be attributed to a known DCM gene variant, motivating the ongoing search for novel disease genes.

Natural History of Dilated Cardiomyopathy in Children.

Background: The long-term progression of idiopathic dilated cardiomyopathy (DCM) in pediatric patients compared with adult patients has not been previously characterized. In this study, we compared outcome and long-term progression of pediatric and adult DCM populations.

Methods And Results: Between 1988 and 2014, 927 DCM patients were consecutively enrolled.

Danon disease - dysregulation of autophagy in a multisystem disorder with cardiomyopathy.

Danon disease is a rare, severe X-linked form of cardiomyopathy caused by deficiency of lysosome-associated membrane protein 2 (LAMP-2). Other clinical manifestations include skeletal myopathy, cognitive defects and visual problems. Although individuals with Danon disease have been clinically described since the early 1980s, the underlying molecular mechanisms involved in pathological progression remain poorly understood.

Electrochemical aptamer scaffold biosensors for detection of botulism and ricin toxins.

Protein toxins present considerable health risks, but detection often requires laborious analysis. Here, we developed electrochemical aptamer biosensors for ricin and botulinum neurotoxins, which display robust and specific signal at nanomolar concentrations and function in dilute serum. These biosensors may aid future efforts for the rapid diagnosis of toxins.

Differentiation of human pluripotent stem cells to retinal pigmented epithelium in defined conditions using purified extracellular matrix proteins.

A potential application of human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) is the generation of retinal pigmented epithelium (RPE) to treat age-related macular degeneration (AMD), a common but incurable retinal disease. RPE cells derived from hESCs (hESC-RPEs) and iPSCs (iPSC-RPEs) express essential RPE markers and can rescue visual function in animal models. However, standard differentiation protocols yield RPE cells at low frequency, especially from iPSC lines, and the common use of Matrigel and xenogeneic feeder cells is not compatible with clinical applications.

Pluripotent human stem cells for the treatment of retinal disease.

Despite advancements made in our understanding of ocular biology, therapeutic options for many debilitating retinal diseases remain limited. Stem cell-based therapies are a potential avenue for treatment of retinal disease, and this mini-review will focus on current research in this area. Cellular therapies to replace retinal pigmented epithelium (RPE) and/or photoreceptors to treat age-related macular degeneration (AMD), Stargardt's macular dystrophy, and retinitis pigmentosa are currently being developed.

Roles of integrins in human induced pluripotent stem cell growth on Matrigel and vitronectin.

Human induced pluripotent stem cells (iPSCs) hold promise as a source of adult-derived, patient-specific pluripotent cells for use in cell-based regenerative therapies. However, current methods of cell culture are tedious and expensive, and the mechanisms underlying cell proliferation are not understood. In this study, we investigated expression and function of iPSC integrin extracellular matrix receptors to better understand the molecular mechanisms of cell adhesion, survival, and proliferation.

Derivation of functional retinal pigmented epithelium from induced pluripotent stem cells.

Human induced pluripotent stem cells (iPSCs) have great promise for cellular therapy, but it is unclear if they have the same potential as human embryonic stem cells (hESCs) to differentiate into specialized cell types. Ocular cells such as the retinal pigmented epithelium (RPE) are of particular interest because they could be used to treat degenerative eye diseases, including age-related macular degeneration and retinitis pigmentosa. We show here that iPSCs generated using Oct4, Sox2, Nanog, and Lin28 can spontaneously differentiate into RPE cells, which can then be isolated and cultured to form highly differentiated RPE monolayers.