Publications by authors named "Robert E Akins"

Cerebral palsy (CP) is a pediatric onset disorder with poorly understood molecular causes and progression, making early diagnosis difficult. Circular RNAs are regulatory RNAs that show promise as biomarkers in various diseases but the role of circular RNAs in CP is beginning to be understood. This study identified the role of circNFIX in regulating the expression of myocyte-specific enhancer factor 2C (MEF2C), an important transcription factor for sarcomere development.

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CircRNAs are a category of regulatory RNAs that have garnered significant attention in the field of regulatory RNA research due to their structural stability and tissue-specific expression. Their circular configuration, formed via back-splicing, results in a covalently closed structure that exhibits greater resistance to exonucleases compared to linear RNAs. The distinctive regulation of circRNAs is closely associated with several physiological processes, as well as the advancement of pathophysiological processes in several human diseases.

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Background: Higher neighborhood deprivation is associated with hypertension diagnosis in youth. In this study, we assess if there is an association between neighborhood deprivation and antihypertensive therapy prescription among insured youth with a primary hypertension diagnosis.

Methods: Using a retrospective cross-sectional design, we assessed the proportion of youth with a diagnosis of primary hypertension prescribed antihypertensive therapy.

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Institutional Development Award (IDeA) programs build research infrastructure in regions with historically low access to NIH funds. The Mentored Research Development Award (MRDA), a professional development program embedded in our IDeA-funded center, provides junior investigators with mentorship and effort offset to write a grant. We evaluated outcomes from the first eight years (2013-2021; = 55) using administrative records, publicly available data, and a self-report survey ( = 46, 84% response rate).

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Aim: To determine the dose-response relationship of collagenase Clostridium histolyticum (CCH) on collagen content and the change in muscle fiber bundle stiffness after ex vivo treatment of adductor longus biopsies with CCH in children with cerebral palsy (CP).

Method: Biopsy samples of adductor longus from children with CP (classified in Gross Motor Function Classification System levels IV and V) were treated with 0 U/mL, 200 U/mL, 350 U/mL, or 500 U/mL CCH; percentage collagen reduction was measured to determine the dose-response. Peak and steady-state stresses were determined at 1%, 2.

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Importance: The association between degree of neighborhood deprivation and primary hypertension diagnosis in youth remains understudied.

Objective: To assess the association between neighborhood measures of deprivation and primary hypertension diagnosis in youth.

Design, Setting, And Participants: This cross-sectional study included 65 452 Delaware Medicaid-insured youths aged 8 to 18 years between January 1, 2014, and December 31, 2019.

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Spastic type cerebral palsy (CP) is a complex neuromuscular disorder that involves altered skeletal muscle microanatomy and growth, but little is known about the mechanisms contributing to muscle pathophysiology and dysfunction. Traditional genomic approaches have provided limited insight regarding disease onset and severity, but recent epigenomic studies indicate that DNA methylation patterns can be altered in CP. Here, we examined whether a diagnosis of spastic CP is associated with intrinsic DNA methylation differences in myoblasts and myotubes derived from muscle resident stem cell populations (satellite cells; SCs).

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Cerebral palsy is a set of common, severe, motor disabilities categorized by a static, nondegenerative encephalopathy arising in the developing brain and associated with deficits in movement, posture, and activity. Spastic CP, which is the most common type, involves high muscle tone and is associated with altered muscle function including poor muscle growth and contracture, increased extracellular matrix deposition, microanatomic disruption, musculoskeletal deformities, weakness, and difficult movement control. These muscle-related manifestations of CP are major causes of progressive debilitation and frequently require intensive surgical and therapeutic intervention to control.

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Aim: To analyze transcriptomes from muscle tissue and cells to improve our understanding of differences in gene expression and molecular function in cerebral palsy (CP) muscle.

Method: In this case-control study, eight participants with CP (five males, three females; mean [SD] age 14y 2mo [1y 8mo]) and 11 comparison individuals (eight males, three females; mean [SD] age 14y 0mo [2y 6mo]) were enrolled after informed consent/assent and skeletal muscle was obtained during surgery. RNA was extracted from tissue and from primary satellite cells grown to form myotubes in vitro.

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Objective: Intimal hyperplasia (IH) is the expansion of the vascular intimal region after intervention, which can lead to stenosis and eventual failure of vascular grafts or interventional procedures such as angioplasty or stent placement. Our goals were to investigate the development of IH in a rabbit open surgical model and to evaluate the associated pathophysiological processes involving decorin and the platelet derived growth factor-BB / platelet derived growth factor receptor-β / mitogen activated protein kinase (PDGF/PDGFR-β/MAPK) pathway.

Methods: We conducted carotid transection and primary anastomosis on five New Zealand White rabbits to induce IH and examined the associated pathophysiological changes.

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Adventitial fibroblasts (AFs) are critical mediators of vascular remodeling. However, the contributions of AFs towards development of vasculature and the specific mechanisms by which these cells regulate physiological expansion of the vasa vasorum, the specialized microvasculature that supplies nutrients to the vascular wall, are not well understood. To determine the regulatory role of AFs in microvascular endothelial cell (MVEC) neovasculogenesis and to investigate the regulatory pathways utilized for communication between the two cell types, AFs and MVECs were cultured together in poly(ethylene glycol)-based hydrogels.

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Cord blood (CB) mononuclear cell populations have demonstrated significant promise in biomaterials-based regenerative therapies; however, the contributions of monocyte and macrophage subpopulations towards proper tissue healing and regeneration are not well understood, and the phenotypic responses of macrophage to microenvironmental cues have not been well-studied. In this work, we evaluated the effects of cytokine stimulation and altered substrate stiffness. Macrophage derived from CB CD14 monocytes adopted distinct inflammatory (M1) and anti-inflammatory (M2a and M2c) phenotypes in response to cytokine stimulation (M1: lipopolysaccharide (LPS) and interferon (IFN-γ); M2a: interleukin (IL)-4 and IL-13; M2c: IL-10) as determined through expression of relevant cell surface markers and growth factors.

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Adventitial fibroblasts (AFs) are major contributors to vascular remodeling and maladaptive cascades associated with arterial disease, where AFs both contribute to and respond to alterations in their surrounding matrix. The relationships between matrix modulus and human aortic AF (AoAF) function are investigated using poly(ethylene glycol)-based hydrogels designed with matrix metalloproteinase (MMP)-sensitive and integrin-binding peptides. Initial equilibrium shear storage moduli for the substrates examined are 0.

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Fully integrated hydrogel channels were fabricated via interfacial bioorthogonal cross-linking, a diffusion-controlled method for the creation and patterning of synthetic matrices based on the rapid bioorthogonal reaction between s-tetrazines (Tz) and trans-cyclooctene (TCO) dienophiles. Injecting an aqueous solution of a bisTCO cross-linker into a reservoir of tetrazine-modified hyaluronic acid (HA-Tz), while simultaneously drawing the syringe needle through the reservoir, yielded a cross-linked hydrogel channel that was mechanically robust. Fluorescent tags and biochemical signals were spatially patterned into the channel wall through time-dependent perfusion of TCO-conjugated molecules into the lumen of the channel.

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Background: Spastic cerebral palsy (CP) is a leading cause of physical disability. Most people with spastic CP are born with it, but early diagnosis is challenging, and no current biomarker platform readily identifies affected individuals. The aim of this study was to evaluate epigenetic profiles as biomarkers for spastic CP.

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Lipid-siRNA assemblies are modified with photo-responsive polymers to enable spatiotemporally-controlled silencing of interleukin 1 beta (IL1β) and cadherin 11 (CDH11), two genes that are essential drivers of maladaptive responses in human aortic adventitial fibroblasts (AoAFs). These hybrid nanocomplexes address the critical challenge of locally mitigating fibrotic actions that lead to the high rates of vascular graft failures. In particular, the lipid-polymer formulations provide potent silencing of IL1β and CDH11 that is precisely modulated by a photo-release stimulus.

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Arteries for bypass grafting are harvested either with neighboring tissue attached or as skeletonized vessels that are free of surrounding tissue. There are significant benefits to skeletonization, but reports suggest that skeletonized vessels may develop structural defects and are at risk for atherosclerosis. We investigated the specific short-term effects of skeletonization on carotid artery biomechanics and microanatomy in a rabbit model.

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Adventitial fibroblasts (AFs) are key determinants of arterial function and critical mediators of arterial disease progression. The effects of altered stiffness, particularly those observed across individuals during normal vascular function, and the mechanisms by which AFs respond to altered stiffness, are not well understood. To study the effects of matrix stiffness on AF phenotype, cytokine production, and the regulatory pathways utilized to interpret basic cell-matrix interactions, human aortic AFs were grown in 5%, 7.

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Purpose: Gubernaculum-cremaster complex development is hormonally regulated and abnormal in a cryptorchid rat model. Using cell tracking techniques and imaging we studied myogenic phenotypes and fates in the fetal rat gubernaculum-cremaster complex.

Materials And Methods: Embryonic day 17 gubernaculum-cremaster complexes were labeled with CellTracker™ or the DNA synthesis marker EdU (5-ethynyl-2'-deoxyuridine), or immobilized in Matrigel® and grown in culture.

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Hydrogels derived from resilin-like polypeptides (RLPs) have shown outstanding mechanical resilience and cytocompatibility; expanding the versatility of RLP-based materials via conjugation with other polypeptides and polymers would offer great promise in the design of a range of materials. Here, we present an investigation of the biochemical and mechanical properties of hybrid hydrogels composed of a recombinant RLP and a multiarm PEG macromer. These hybrid hydrogels can be rapidly cross-linked through a Michael-type addition reaction between the thiols of cysteine residues on the RLP and vinyl sulfone groups on the multiarm PEG.

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Study Hypothesis: Susceptibility to inherited cryptorchidism in the LE/orl rat may be associated with genetic loci that influence developmental patterning of the gubernaculum by the fetal testis.

Study Finding: Cryptorchidism in the LE/orl rat is associated with a unique combination of homozygous minor alleles at multiple loci, and the encoded proteins are co-localized with androgen receptor (AR) and Leydig cells in fetal gubernaculum and testis, respectively.

What Is Known Already: Prior studies have shown aberrant perinatal gubernacular migration, muscle patterning defects and reduced fetal testicular testosterone in the LE/orl strain.

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Adult and congenital cardiovascular diseases are significant health problems that are often managed using surgery. Bypass grafting is a principal therapy, but grafts fail at high rates due to hyperplasia, fibrosis, and atherosclerosis. Biocompatible, cellularized materials that attenuate these complications and encourage healthy microvascularization could reduce graft failure, but an improved understanding of biomaterial effects on human stem cells is needed to reach clinical utility.

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Purpose: Based on a genome-wide association study of testicular dysgenesis syndrome showing a possible association with TGFBR3, we analyzed data from a larger, phenotypically restricted cryptorchidism population for potential replication of this signal.

Materials And Methods: We excluded samples based on strict quality control criteria, leaving 844 cases and 2,718 controls of European ancestry that were analyzed in 2 separate groups based on genotyping platform (ie Illumina® HumanHap550, version 1 or 3, or Human610-Quad, version 1 BeadChip in group 1 and Human OmniExpress 12, version 1 BeadChip platform in group 2). Analyses included genotype imputation at the TGFBR3 locus, association analysis of imputed data with correction for population substructure, subsequent meta-analysis of data for groups 1 and 2, and selective genotyping of independent cases (330) and controls (324) for replication.

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Cryptorchidism, or undescended testis, is a common male genital anomaly of unclear etiology. Hormonal stimulation of the developing fetal gubernaculum by testicular androgens and insulin-like 3 (INSL3) is required for testicular descent. In studies of the orl fetal rat, one of several reported strains with inherited cryptorchidism, we studied hormone levels, gene expression in intact and hormone-stimulated gubernaculum, and imaging of the developing cremaster muscle facilitated by a tissue clearing protocol to further characterize development of the orl gubernaculum.

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