From scientific discovery to cures: bright stars within a galaxy.

We propose that data mining and network analysis utilizing public databases can identify and quantify relationships between scientific discoveries and major advances in medicine (cures). Further development of such approaches could help to increase public understanding and governmental support for life science research and could enhance decision making in the quest for cures.

Muscle-specific activation of Ca(2+)/calmodulin-dependent protein kinase IV increases whole-body insulin action in mice.

AIMS/HYPOTHESIS: Aerobic exercise increases muscle glucose and improves insulin action through numerous pathways, including activation of Ca(2+)/calmodulin-dependent protein kinases (CAMKs) and peroxisome proliferator γ coactivator 1α (PGC-1α). While overexpression of PGC-1α increases muscle mitochondrial content and oxidative type I fibres, it does not improve insulin action. Activation of CAMK4 also increases the content of type I muscle fibres, PGC-1α level and mitochondrial content. However, it remains unknown whether CAMK4 activation improves insulin action on glucose metabolism in vivo. METHODS: The effects of CAMK4 activation on skeletal muscle insulin action were quantified using transgenic mice with a truncated and constitutively active form of CAMK4 (CAMK4([Symbol: see text])) in skeletal muscle. Tissue-specific insulin sensitivity was assessed in vivo using a hyperinsulinaemic-euglycaemic clamp and isotopic measurements of glucose metabolism. RESULTS: The rate of insulin-stimulated whole-body glucose uptake was increased by ∼25% in CAMK4([Symbol: see text]) mice. This was largely attributed to an increase of ∼60% in insulin-stimulated glucose uptake in the quadriceps, the largest hindlimb muscle. These changes were associated with improvements in insulin signalling, as reflected by increased phosphorylation of Akt and its substrates and an increase in the level of GLUT4 protein. In addition, there were extramuscular effects: CAMK4([Symbol: see text]) mice had improved hepatic and adipose insulin action. These pleiotropic effects were associated with increased levels of PGC-1α-related myokines in CAMK4([Symbol: see text]) skeletal muscle. CONCLUSIONS/INTERPRETATION: Activation of CAMK4 enhances mitochondrial biogenesis in skeletal muscle while also coordinating improvements in whole-body insulin-mediated glucose.

A global partnership in medical education between Duke University and the National University of Singapore.

Duke University and the National University of Singapore (NUS) have partnered to launch a new medical school that brings the American style of postbaccalaureate medical education to Asia. The new institution, called the Duke-NUS Graduate Medical School (GMS) and located in Singapore adjacent to the Singapore General Hospital, admitted its inaugural class of students representing citizens of seven nations in August 2007. The project represents an investment of more than $350 million from three ministries of the Singapore government, and a commitment on Duke's part to provide senior leadership and recruit faculty from Duke, from other international locales, and from within Singapore itself. Graduating students who complete the four-year Duke curriculum will receive an MD degree awarded jointly by Duke and NUS, thereby distinguishing this school from medical education in most Asian institutions that award an MBBS degree after a five-year period of study that follows directly from secondary school. The emphasis of the Duke-NUS GMS is to prepare physician-scientists for academic careers, with plans for 20% of each class to complete a combined MD/PhD degree. This article describes events leading up to this partnership and details of the relationship, including curriculum, organizational structure, milestones, and goals.

Improving the health of the community: Duke's experience with community engagement.

Evidence is accumulating that the United States is falling behind in its potential to translate biomedical advances into practical applications for the population. Societal forces, increased awareness of health disparities, and the direction of clinical and translational research are producing a compelling case for AHCs to bridge the gaps between scientific knowledge and medical advancement and between medical advancement and health. The Duke University Health System, the city and county of Durham, North Carolina, and multiple local nonprofit and civic organizations are actively engaged in addressing this need. More than a decade ago, Duke and its community partners began collaborating on projects to meet specific, locally defined community health needs. In 2005, Duke and Durham jointly developed a set of Principles of Community Engagement reflecting the key elements of the partnership and crafted an educational infrastructure to train health professionals in the principles and practice of community engagement. And, most recently, Duke has worked to establish the Duke Translational Medicine Institute, funded in part by a National Institutes of Health Clinical Translational Science Award, to improve health through innovative behavioral, social, and medical knowledge, matched with community engagement and the information sciences.

Transcriptional regulation of cardiac progenitor cell populations.

Transcriptome-wide analysis of dynamically regulated progenitor cell populations has the potential to elucidate key aspects of cardiac development. The heart, as the first organ to develop in the mammal, is a technically challenging but clinically relevant target for study. To define the transcriptional program of the cardiac progenitor, we used a novel transgenic strategy and fluorescence-activated cell sorting to reliably label and isolate cardiac progenitors directly from mouse embryos. Pure populations of cardiac progenitor cells were isolated from the cardiac crescent and 2 subsequent stages of heart development: the linear heart tube and the looping heart. RNA was isolated from stage-specific cardiac progenitors and subjected to transcriptome analysis by oligonucleotide array hybridization. The cardiac transcriptional regulatory programs were compared with the molecular programs of age-matched noncardiac embryonic cells, embryonic stem cells, adult cardiomyocytes, and each other to identify sets of genes exhibiting differential expression in the cardiac progenitor cell population. These results define the transcriptional profile of mammalian cardiac progenitor cells and provide insight into the molecular regulation of the earliest periods of heart development.

MCIP1 overexpression suppresses left ventricular remodeling and sustains cardiac function after myocardial infarction.

Pathological remodeling of the left ventricle (LV) after myocardial infarction (MI) is a major cause of heart failure. Although cardiac hypertrophy after increased loading conditions has been recognized as a clinical risk factor for human heart failure, it is unknown whether post-MI hypertrophic remodeling of the myocardium is beneficial for cardiac function over time, nor which regulatory pathways play a crucial role in this process. To address these questions, transgenic (TG) mice engineered to overexpress modulatory calcineurin-interacting protein-1 (MCIP1) in the myocardium were used to achieve cardiac-specific inhibition of calcineurin activation. MCIP1-TG mice and their wild-type (WT) littermates, were subjected to MI and analyzed 4 weeks later. At 4 weeks after MI, calcineurin was activated in the LV of WT mice, which was significantly reduced in MCIP1-TG mice. WT mice displayed a 78% increase in LV mass after MI, which was reduced by 38% in MCIP1-TG mice. Echocardiography indicated marked LV dilation and loss of systolic function in WT-MI mice, whereas TG-MI mice displayed a remarkable preservation of LV geometry and contractility, a pronounced reduction in myofiber hypertrophy, collagen deposition, and beta-MHC expression compared with WT-MI mice. Together, these results reveal a protective role for MCIP1 in the post-MI heart and suggest that calcineurin is a crucial regulator of postinfarction-induced pathological LV remodeling. The improvement in functional, structural, and molecular abnormalities in MCIP1-TG mice challenges the adaptive value of post-MI hypertrophy of the remote myocardium. The full text of this article is available online at http://circres.ahajournals.org.

The role of modulatory calcineurin-interacting proteins in calcineurin signaling.

Modulatory calcineurin-interacting proteins (MCIPs), also known as the Down syndrome critical region 1 (DSCR1) and DSCR1-like proteins, are a recently described family of small, structurally related proteins that are preferentially expressed in heart, skeletal muscle, and brain. MCIP proteins can bind to and inhibit calcineurin, a calcium/calmodulin-regulated serine/threonine protein phosphatase that is activated during cardiac hypertrophy and failure. Transcription of the mammalian MCIP1 gene is induced by calcineurin, suggesting that it functions as an endogenous feedback regulator of calcineurin signal transduction. Forced expression of human MCIP1 protein in the hearts of transgenic mice attenuates the hypertrophic response to a broad range of stimuli. This review summarizes work from a number of laboratories on the structure, regulation, and function of MCIP proteins.

Incubating the research independence of a medical scientist training program graduate: a case study.

PROBLEM: Physician-scientists play a critical role in discovering new biological knowledge and translating findings into medical practices that can improve clinical outcomes. Collectively, the National Institutes of Health (NIH) and its affiliated Medical Scientist Training Programs (MSTPs) invest upwards of $500,000 to fully train each of the 900+ MD/PhD students enrolled in these programs. Nevertheless, graduates face the challenges of navigating fragmented intervals of clinical training and research engagement, reinitiating research upon completing their residencies, managing financial pressures, and competing for funding following what is typically four or more years of research inactivity. Together, these barriers contribute to the high attrition rate of MSTP graduates from research careers. APPROACH: The authors designed and implemented (2009-2014), for a single trainee, an alternative postgraduate training model characterized by early research engagement, strategic mentoring, unyoked clinical and research milestones, and dedicated financial support. OUTCOMES: The pilot training experiment was so successful that the trainee secured an NIH project grant and completed his transition to research independence 3.5 years after starting the experimental training schedule-nearly 9 years earlier (based on age) than is typical for MD/PhDs transitioning from mentored to independent research. This success has demonstrated that unyoking research engagement from conventional calendar-based clinical training milestones is a feasible, effective means of incubating research independence in MSTP graduates. NEXT STEPS: The authors encourage the design and application of similar unconventional approaches that interweave residency training with ongoing research activity for appropriate candidates, especially in subspecialties with increased MSTP graduate enrollment.

Prospective medicine: the next health care transformation.

The introduction of science into the practice of medicine in the early 20th century was a transforming event for the profession. Now, breakthroughs in science and know how make it possible to transform care once again and to fix the broken U.S. health care system. To realize this potential, new models of prospective health care must be created and validated. Prospective health care would determine the risk for individuals to develop specific diseases, detect the disease's earliest onset, and prevent or intervene early enough to provide maximum benefit. Each individual would have a personalized health plan to accomplish this. Current knowledge is already sufficient to implement this approach, but there are no effective practice models, delivery systems, and appropriate reimbursement mechanisms. The authors describe the mechanisms of managing care prospectively, describe the components of a personalized health plan, and show how prospective care could relate to a community or group of covered individuals. They conclude by stressing that all interested parties, including academic health centers, insurers, and payers, will need to work together to develop innovative applications of new technologies and appropriate delivery models. At their own institution, pilot programs to foster prospective health care have already begun, and another initiative to develop models to use genomic medicine is also underway. Bipartisan political support will also be needed to help achieve rational reimbursement between providers and payers, so that prospective care can fulfill its promise of being the best cost-effective model to improve the nation's health.

Protein-coated poly(L-lactic acid) fibers provide a substrate for differentiation of human skeletal muscle cells.

Tissue engineering represents a potential method for repairing damaged skeletal muscle tissue. Extracellular matrix (ECM) proteins were evaluated for their ability to aid in cell attachment, whereas a poly(L-lactic acid) (PLLA) fiber scaffold was tested as a substrate for the differentiation of human skeletal muscle cells. In comparison to uncoated or gelatin-coated PLLA films, cell attachment increased significantly (p < 0.001) on PLLA films coated with ECM gel, fibronectin, or laminin. Myoblasts differentiated into multinucleated myofibers on ECM gel-coated PLLA fibers, and expressed muscle markers such as myosin and alpha-actinin. Oligonucleotide microarray analysis showed similar gene expression profiles for human skeletal muscle cells on ECM gel-coated PLLA fibers as to that observed for myofibers on tissue culture plates. Therefore, PLLA fibers coated with ECM proteins provide a scaffold for the development of skeletal muscle tissue for tissue engineering and cell transplantation applications.

Bcl3 interacts cooperatively with peroxisome proliferator-activated receptor gamma (PPARgamma) coactivator 1alpha to coactivate nuclear receptors estrogen-related receptor alpha and PPARalpha.

Estrogen-related receptors (ERRs) play critical roles in regulation of cellular energy metabolism in response to inducible coactivators such as peroxisome proliferator-activated receptor gamma (PPARgamma) coactivator 1alpha (PGC-1alpha). A yeast two-hybrid screen led to the identification of the cytokine-stimulated transcriptional regulator, Bcl3, as an ERRalpha coactivator. Bcl3 was shown to synergize with PGC-1alpha to coactivate ERRalpha. Chromatin immunoprecipitation studies demonstrated that ERRalpha, PGC-1alpha, and Bcl3 form a complex on an ERRalpha-responsive element within the pyruvate dehydrogenase kinase 4 gene promoter in cardiac myocytes. Mapping studies demonstrated that Bc13 interacts with PGC-1alpha and ERRalpha, allowing for interaction with both proteins. Transcriptional profiling demonstrated that Bcl3 activates genes involved in diverse pathways including a subset involved in cellular energy metabolism known to be regulated by PGC-1alpha, ERRalpha, and a second nuclear receptor, PPARalpha. Consistent with the gene expression profiling results, Bcl3 was shown to synergistically coactivate PPARalpha with PGC-1alpha in a manner similar to ERRalpha. We propose that the cooperativity between Bcl3 and PGC-1alpha may serve as a point of convergence on nuclear receptor targets to direct programs orchestrating inflammatory and energy metabolism responses in heart and other tissues.

Regulation of GLUT4 expression in denervated skeletal muscle.

Denervation by sciatic nerve resection causes decreased muscle glucose transporter 4 (GLUT4) expression, but little is known about the signaling events that cause this decrease. Experiments were designed to test the hypothesis that decreased GLUT4 expression in denervated muscle occurs because of decreased calcium/CaMK activity, which would then lead to decreased activation of the transcription factors myocyte enhancer factor 2 (MEF2) and GLUT4 enhancer factor (GEF), which are required for normal GLUT4 expression. GLUT4 mRNA was elevated in mice expressing constitutively active CaMK isoform IV (CaMKIV) and decreased by denervation. Denervation decreased GEF binding to the promoter and the content of GEF in the nucleus, but there was no change in either MEF2 binding or MEF2 protein content. Expression of a MEF2-dependent reporter gene did not change in denervated skeletal muscle. To determine the domains of the GLUT4 promoter that respond to denervation, transgenic mice expressing the chloramphenicol acetyl transferase (CAT) reporter gene driven by different lengths of the human GLUT4 promoter were denervated. Using several different promoter/reporter gene constructs, we found that all areas of the GLUT4 promoter were truncated or missing, except for the MEF2 binding domain and the basal promoter. All of the GLUT4 promoter/CAT reporter constructs evaluated responded normally to denervation. Our data lead us to conclude that decreased CaMK activity is not the reason for decreased GLUT4 content in denervated muscle and that negative control of GLUT4 expression is not mediated through the MEF2 or GEF-binding domains. These findings indicate that withdrawal of a GEF- or MEF2-dependent signal is not likely a major determinant of the denervation effect on GLUT4 expression. Thus, the response to denervation may be mediated by other elements present in the basal promoter of the GLUT4 gene.