Diabetes Basic Training Program: Empowering Veterans for Wellness.

Background: Diabetes impacts 1 in 4 patients in the Veterans Health Administration and is associated with serious negative health consequences in addition to high health care system utilization and cost. The Cincinnati Veterans Affairs Medical Center developed Diabetes Basic Training, a 9-week intervention that blends medical consultation with group support and training in self-management strategies for enhancing patient motivation and empowerment. Observations: Diabetes Basic Training combined 3 monthly shared medical appointments and 6 Diabetes Self-Management Program sessions led in part by trained peers with diabetes. Diabetes Self-Management Program sessions focus on educating patients on diabetes and self-management tools and encourage active practice in building self-management skills and confidence. During shared medical appointments, a clinical psychologist or psychology postdoctoral fellow skilled in motivational interviewing facilitated the group to enhance patient motivation and empowerment for improved diabetes self-management. Conclusions: This novel program combined 2 types of group appointments to provide veterans with access to health care professionals and education on diabetes self-management. Preliminary results suggest the need for larger studies and that these programs may be beneficial in a veteran population.

Characterization of a small animal growth plate injury model using microcomputed tomography.

Injuries to the growth plate remain a significant clinical challenge. The need to better understand mechanisms of growth disruption following transphyseal injuries and evaluate new therapeutic approaches to growth restoration motivates development of a well characterized model of growth plate injury. The goals of this study were to develop a growth plate defect model in the rat and to use microcomputed tomography (micro-CT) imaging to detect and quantify associated changes in growth plate morphology and mineralization over time following injury and in response to treatment. Three-dimensional images of the growth plate were created from micro-CT scans and used to quantify the volume of mineralized tissue within the defect site. Growth plate thickness and volume as well as the degree of growth plate fusion were also measured from the reconstructed 3D images. Growth deficiency was then quantified as a function of time post-injury from whole limb micro-CT scans. Finally, this model was used to determine the ability of an injectable in situ gelling hydrogel to prevent formation of a bony bridge within the defect and the subsequent effect on limb length deficiency and changes to growth plate morphology. Growth plate injury resulted in significant shortening of the defect limb by day 28 and significant thinning and fusion of the surrounding growth plate up to day 112. Limb length reduction was correlated with changes in the growth plate volume and average thickness at day 56. Injection of an in situ gelling agarose into the defect resulted in a reduction of limb length discrepancy as well as a thicker growth plate on average compared to empty defect controls. These results establish a novel method of characterizing changes in whole bone and growth plate morphology due to a growth plate injury and indicate that treatment with agarose hydrogel reduces limb length discrepancy but is not sufficient to regenerate growth plate tissue or fully restore growth function.

Socioeconomic Status and Coronary Heart Disease Risk: The Role of Social Cognitive Factors.

The aim of this study is to examine existing research on social cognitive factors that may, in part, mediate the relationship between socioeconomic status (SES) and coronary heart disease (CHD). We focus on how social status is 'carried' in the mental systems of individuals, and how these systems differentially affect CHD risk and associated behaviors. To this end, literatures documenting the association of various social cognitive factors (e.g., social comparison, perceived discrimination, and self-efficacy) with cardiovascular disease are reviewed as are literatures regarding the relationship of these factors to SES. Possible mechanisms through which social cognitions may affect health are addressed. In addition, directions for future research are discussed, and a model identifying the possible associations between social cognitive factors, SES, and coronary disease is provided.

Subjective socioeconomic status and presence of the metabolic syndrome in midlife community volunteers.

OBJECTIVE: Objective indices of socioeconomic status (SES) predict diverse sources of morbidity and mortality as well as numerous biological and behavioral risk factors for disease. Here we examine whether subjective measures of SES may be similarly associated with measured risk factors including the metabolic syndrome and its components of elevated blood pressure, high fasting glucose, dyslipidemia, and central adiposity. METHODS: Observations were based on a community sample of 981 adults (30-54 years of age; 52% female; 84% white, 16% African American). Subjective SES was measured, using the nationally referenced (U.S.) MacArthur Scale of Subjective Social Status, and objective SES was indexed by composite of years of education and family income. RESULTS: Likelihood of meeting the criteria for presence of the metabolic syndrome varied inversely with subjective SES (odds ratio [OR] = 0.75; 95% Confidence Interval [CI] = 0.64-0.88, for a 1-standard deviation increase in subjective SES, adjusted for age, sex, and race), and this association persisted on further adjustment for objective SES (OR = 0.82; 95% CI = 0.68-0.99). Subjective SES was also associated inversely with blood pressure, waist circumference, and serum triglycerides, and positively with HDL cholesterol. Level of physical activity and smoking status were predicted by subjective SES as well, but adjusting for these health behaviors did not appreciably reduce associations of subjective SES with metabolic syndrome and syndrome components. CONCLUSIONS: These findings support speculation that perceived social standing is associated with prominent cardiovascular risk factors and may prove a useful adjunct to conventional socioeconomic indicators in epidemiological research.

Human mesenchymal stem cell differentiation on self-assembled monolayers presenting different surface chemistries.

Human mesenchymal stem cells (hMSCs) have tremendous potential as a cell source for regenerative medicine due to their capacity for differentiation into a wide range of connective tissue cell types. Although significant progress has been made in the identification of defined growth factor conditions to induce lineage commitment, the effect of underlying biomaterial properties on functional differentiation is far less understood. Here we conduct a systematic assessment of the role for surface chemistry on cell growth, morphology, gene expression and function during hMSC commitment along osteogenic, chondrogenic and adipogenic lineages. Using self-assembled monolayers of omega-functionalized alkanethiols on gold as model substrates, we demonstrate that biomaterial surface chemistry differentially modulates hMSC differentiation in a lineage-dependent manner. These results highlight the importance of initial biomaterial surface chemistry on long-term functional differentiation of adult stem cells, and suggest that surface properties are a critical parameter that must be considered in the design of biomaterials for stem cell-based regenerative medicine strategies.

CTCF: master weaver of the genome.

CTCF is a highly conserved zinc finger protein implicated in diverse regulatory functions, including transcriptional activation/repression, insulation, imprinting, and X chromosome inactivation. Here we re-evaluate data supporting these roles in the context of mechanistic insights provided by recent genome-wide studies and highlight evidence for CTCF-mediated intra- and interchromosomal contacts at several developmentally regulated genomic loci. These analyses support a primary role for CTCF in the global organization of chromatin architecture and suggest that CTCF may be a heritable component of an epigenetic system regulating the interplay between DNA methylation, higher-order chromatin structure, and lineage-specific gene expression.

Parental education is related to C-reactive protein among female middle-aged community volunteers.

Growing evidence suggests that socioeconomic attributes of both childhood and adulthood confer risk for cardiovascular morbidity and mortality. In this study, we examine the association of both parental and individual educational attainment with C-reactive protein (CRP), an inflammatory mediator relevant to cardiovascular pathophysiology, in a mid-life community sample. Subjects were 811 men and women (394 men/417 women; 87% European-American/13% African-American), 30-54 years of age. Plasma concentrations of CRP were determined from blood samples obtained at a single session following an overnight fast. Regression analyses adjusting for age and race showed both parental education and individual education to be associated inversely with CRP in women, but not men. The relationship of parental education with CRP in women persisted on multivariable adjustment for both lifestyle risk factors (smoking, alcohol consumption, sleep, exercise, body mass index) and individual SES. Independent of reported personal educational attainment, mid-life adult women whose parents achieved fewer years of educational attainment exhibit higher levels of circulating CRP than women with higher parental education. This association may help explain the increased risk of atherosclerotic cardiovascular morbidity and mortality conferred by low childhood socioeconomic status.

Retroviral-mediated gene therapy for the differentiation of primary cells into a mineralizing osteoblastic phenotype.

Bone tissue engineering has emerged as a promising strategy for the repair of critical-sized skeletal fractures. However, the clinical application of this approach has been limited by the availability of a robust mineralizing cell source. Non-osteogenic cells, such as skin fibroblasts, are an attractive cell-source alternative because they are easy to harvest from autologous donor skin biopsies and display a high capacity for in vitro expansion. We have recently demonstrated that retroviral gene delivery of the osteoblastic transcription factor Runx2/Cbfa1 promotes osteogenic differentiation in primary dermal fibroblasts cultured in monolayer. Notably, sustained expression of Runx2 was not sufficient to promote functional osteogenesis in these cells, and co-treatment with the steroid hormone dexamethasone was required to induce deposition of biologically-equivalent matrix mineralization. On the basis of these results, we then investigated the osteogenic capacity of these genetically engineered fibroblasts when seeded on polymeric scaffolds in vitro and in vivo. These experiments demonstrated that Runx2-expressing fibroblasts seeded on collagen scaffolds produce significant levels of matrix mineralization after 28 days in vivo implantation in a subcutaneous, heterotopic site. Overall, these results offer evidence that transcription factor-based gene therapy may be a powerful strategy for the conversion of a non-osteogenic cellular phenotype into a mineralizing cell source for bone repair applications. This concept may also be applied to control functional differentiation in a broad range of cell types and tissue engineering applications. The chapter below outlines detailed methods for the isolation and ex vivo genetic modification of primary dermal fibroblasts using retroviral-mediated delivery of the Runx2 transgene in both monolayer culture and three-dimensional scaffolds.

Engineering graded tissue interfaces.

Interfacial zones between tissues provide specialized, transitional junctions central to normal tissue function. Regenerative medicine strategies focused on multiple cell types and/or bi/tri-layered scaffolds do not provide continuously graded interfaces, severely limiting the integration and biological performance of engineered tissue substitutes. Inspired by the bone-soft tissue interface, we describe a biomaterial-mediated gene transfer strategy for spatially regulated genetic modification and differentiation of primary dermal fibroblasts within tissue-engineered constructs. We demonstrate that zonal organization of osteoblastic and fibroblastic cellular phenotypes can be engineered by a simple, one-step seeding of fibroblasts onto scaffolds containing a spatial distribution of retrovirus encoding the osteogenic transcription factor Runx2/Cbfa1. Gradients of immobilized retrovirus, achieved via deposition of controlled poly(L-lysine) densities, resulted in spatial patterns of transcription factor expression, osteoblastic differentiation, and mineralized matrix deposition. Notably, this graded distribution of mineral deposition and mechanical properties was maintained when implanted in vivo in an ectopic site. Development of this facile and robust strategy is significant toward the regeneration of continuous interfacial zones that mimic the cellular and microstructural characteristics of native tissue.

Dermal fibroblasts genetically modified to express Runx2/Cbfa1 as a mineralizing cell source for bone tissue engineering.

Cell-based bone tissue engineering strategies have been effectively applied toward the development of grafting templates for skeletal repair and regeneration, but remain limited by inadequate availability of a robust mineralizing cell source. Dermal fibroblasts have emerged as a particularly promising cell alternative because they are harvested from autologous donors through minimally invasive skin biopsy and display a high capacity for in vitro expansion. In the present study, we investigated retroviral gene delivery of the osteogenic transcription factor Runx2 as a mineralization induction strategy in primary dermal fibroblasts. We demonstrate that constitutive overexpression of Runx2 induced osteogenic gene expression and mineralized nodule deposition in fibroblasts cultured on 3-dimensional fibrous collagen disks in vitro. Fourier transform infrared analysis revealed that Runx2 expressing fibroblasts deposit a carbonate-containing, poorly crystalline hydroxyapatite, whereas control constructs did not contain biologically-equivalent mineral. Importantly, Runx2-transduced fibroblasts formed mineralized templates in vivo after implantation in a subcutaneous, heterotopic site, whereas minimal mineralization was evident in control constructs. Furthermore, immunohistochemical analysis indicated that Runx2-engineered cells co-localized with mineral deposits in vivo, suggesting that nodule formation primarily originated from transplanted donor cells. These results establish Runx2-genetic engineering as a strategy for the conversion of a non-osteogenic cellular phenotype into a mineralizing cell source for bone repair applications. Cellular therapies based on primary dermal fibroblasts would be particularly beneficial for patients with compromised ability to recruit endogenous osteoprogenitors to the site of injury as a result of extreme trauma, age, radiation treatment, or osteolytic disease.

Genetic engineering for skeletal regenerative medicine.

The clinical challenges of skeletal regenerative medicine have motivated significant advances in cellular and tissue engineering in recent years. In particular, advances in molecular biology have provided the tools necessary for the design of gene-based strategies for skeletal tissue repair. Consequently, genetic engineering has emerged as a promising method to address the need for sustained and robust cellular differentiation and extracellular matrix production. As a result, gene therapy has been established as a conventional approach to enhance cellular activities for skeletal tissue repair. Recent literature clearly demonstrates that genetic engineering is a principal factor in constructing effective methods for tissue engineering approaches to bone, cartilage, and connective tissue regeneration. This review highlights this literature, including advances in the development of efficacious gene carriers, novel cell sources, successful delivery strategies, and optimal target genes. The current status of the field and the challenges impeding the clinical realization of these approaches are also discussed.

Virus-based gene therapy strategies for bone regeneration.

Gene therapy has emerged as a promising strategy for the repair and regeneration of damaged musculoskeletal tissues. Application of this paradigm to bone healing has shown enhanced efficacy in preclinical animal studies compared to conventional bone grafting approaches. This review discusses current and emerging virus-based genetic engineering strategies for the delivery of therapeutic molecules which promote skeletal regeneration. Viral gene delivery vectors are discussed in the context of bone repair in order to illustrate the challenges and applications of these methods with tissue-specific examples. Moreover the concepts discussed can be broadly applied to promote healing in a wide range of tissues. We also present important considerations involved in the application of these gene therapy techniques to a variety of osteogenic (e.g. bone marrow-derived cells) and non-osteogenic (e.g. fibroblasts and skeletal myoblasts) cell types. Criteria for the selection of regenerative molecules with soluble versus intracellular modes of action and emerging combinatorial approaches are also discussed. Overall, gene transfer technologies have the potential to overcome limitations associated with existing bone grafting approaches and may enable investigators to design therapies which more closely mimic the complex spatial and temporal cascade of proteins involved in endogenous bone development and repair.

Mineralization capacity of Runx2/Cbfa1-genetically engineered fibroblasts is scaffold dependent.

Development of tissue-engineered constructs for skeletal regeneration of large critical-sized defects requires the identification of a sustained mineralizing cell source and careful optimization of scaffold architecture and surface properties. We have recently reported that Runx2-genetically engineered primary dermal fibroblasts express a mineralizing phenotype in monolayer culture, highlighting their potential as an autologous osteoblastic cell source which can be easily obtained in large quantities. The objective of the present study was to evaluate the osteogenic potential of Runx2-expressing fibroblasts when cultured in vitro on three commercially available scaffolds with divergent properties: fused deposition-modeled polycaprolactone (PCL), gas-foamed polylactide-co-glycolide (PLGA), and fibrous collagen disks. We demonstrate that the mineralization capacity of Runx2-engineered fibroblasts is scaffold dependent, with collagen foams exhibiting ten-fold higher mineral volume compared to PCL and PLGA matrices. Constructs were differentially colonized by genetically modified fibroblasts, but scaffold-directed changes in DNA content did not correlate with trends in mineral deposition. Sustained expression of Runx2 upregulated osteoblastic gene expression relative to unmodified control cells, and the magnitude of this expression was modulated by scaffold properties. Histological analyses revealed that matrix mineralization co-localized with cellular distribution, which was confined to the periphery of fibrous collagen and PLGA sponges and around the circumference of PCL microfilaments. Finally, FTIR spectroscopy verified that mineral deposits within all Runx2-engineered scaffolds displayed the chemical signature characteristic of carbonate-containing, poorly crystalline hydroxyapatite. These results highlight the important effect of scaffold properties on the capacity of Runx2-expressing primary dermal fibroblasts to differentiate into a mineralizing osteoblastic phenotype for bone tissue engineering applications.

Glucocorticoid-induced osteogenesis is negatively regulated by Runx2/Cbfa1 serine phosphorylation.

Glucocorticoid hormones have complex stimulatory and inhibitory effects on skeletal metabolism. Endogenous glucocorticoid signaling is required for normal bone formation in vivo, and synthetic glucocorticoids, such as dexamethasone, promote osteoblastic differentiation in several in vitro model systems. The mechanism by which these hormones induce osteogenesis remains poorly understood. We demonstrate here that the coordinate action of dexamethasone and the osteogenic transcription factor Runx2/Cbfa1 synergistically induces osteocalcin and bone sialoprotein gene expression, alkaline phosphatase activity, and biological mineral deposition in primary dermal fibroblasts. Dexamethasone decreased Runx2 phosphoserine levels, particularly on Ser125, in parallel with the upregulation of mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1) through a glucocorticoid-receptor-mediated mechanism. Inhibition of MKP-1 abrogated the dexamethasone-induced decrease in Runx2 serine phosphorylation, suggesting that glucocorticoids modulate Runx2 phosphorylation via MKP-1. Mutation of Ser125 to glutamic acid, mimicking constitutive phosphorylation, inhibited Runx2-mediated osteoblastic differentiation, which was not rescued by dexamethasone treatment. Conversely, mutation of Ser125 to glycine, mimicking constitutive dephosphorylation, markedly increased osteoblastic differentiation, which was enhanced by, but did not require, additional dexamethasone supplementation. Collectively, these results demonstrate that dexamethasone induces osteogenesis, at least in part, by modulating the phosphorylation state of a negative-regulatory serine residue (Ser125) on Runx2. This work identifies a novel mechanism for glucocorticoid-induced osteogenic differentiation and provides insights into the role of Runx2 phosphorylation during skeletal development.