What makes community-based, multilevel physical activity promotion last? A systematic review with narrative synthesis on factors for sustainable implementation

AIM

To follow the need for more research and strategies to enhance the knowledge of sustainable implementation, we examined cases of community-based, multilevel physical activity-related health promotion after initial funding has ceased and aimed to identify factors that influence their sustainable implementation.

METHODS

Five scientific databases (PubMed; Scopus; Ebsco Host with CINAHL, PsychInfo, and Sportdiscus; ProQuest and Web of Science) were systematically searched for relevant literature in December 2021. Three reviewers performed a title/abstract screening and independently screened the full texts of the remaining papers, followed by a quality assessment. A narrative synthesis method, including qualitative text analysis, was used to synthesise retrieved articles. As starting point, the framework of Schell et al. containing nine domains for sustainability capacity was used and new emerging themes were inductively added.

RESULTS

The search revealed 270 potentially eligible articles out of 27,652 hits. After the systematic review process, 14 studies were included. In the synthesis, 14 factors influencing the sustainablity of community-based, multilevel physical activity-related health promotion were identified of which six are new factors compared to Schell et al. In particular, our findings bring forth a novel understanding of the importance of the factors 'Participation and Partnerships', 'Empowerment and Capacity Building' and 'Community Support'. A dynamic interplay and high connectedness between factors were visible.

CONCLUSION

The identified factors can help establish a better understanding of sustainability processes within whole-system approaches intervening on multiple levels in the community with the aim of systems change. They are relevant for practitioners, researchers and policy makers alike. Future research should more closely examine based on further theoretical elaboration how an interplay between the factors can promote sustainability and which interdependencies are of particular importance in facilitating sustainable and equitable change.

Decreasing Wapl dosage partially corrects embryonic growth and brain transcriptome phenotypes in Nipbl+/- embryos

Cohesin rings interact with DNA and modulate the expression of thousands of genes. NIPBL loads cohesin onto chromosomes, and WAPL takes it off. Haploinsufficiency for NIPBL causes a developmental disorder, Cornelia de Lange syndrome (CdLS), that is modeled by Nipbl^+/- mice. Mutations in WAPL have not been shown to cause disease or gene expression changes in mammals. Here, we show dysregulation of >1000 genes in Wapl^Δ/+ embryonic mouse brain. The patterns of dysregulation are highly similar in Wapl and Nipbl heterozygotes, suggesting that Wapl mutations may also cause human disease. Since WAPL and NIPBL have opposite effects on cohesin's association with DNA, we asked whether decreasing Wapl dosage could correct phenotypes seen in Nipbl^+/- mice. Gene expression and embryonic growth are partially corrected, but perinatal lethality is not. Our data are consistent with the view that cohesin dynamics play a key role in regulating gene expression.

Decreasing Wapl dosage partially corrects embryonic growth and brain transcriptome phenotypes in Nipbl+/- embryos

Cohesin rings interact with DNA and modulate the expression of thousands of genes. NIPBL loads cohesin onto chromosomes, and WAPL takes it off. Haploinsufficiency for NIPBL causes a developmental disorder, Cornelia de Lange syndrome (CdLS), that is modeled by Nipbl^+/- mice. Mutations in WAPL have not been shown to cause disease or gene expression changes in mammals. Here, we show dysregulation of >1000 genes in Wapl^Δ/+ embryonic mouse brain. The patterns of dysregulation are highly similar in Wapl and Nipbl heterozygotes, suggesting that Wapl mutations may also cause human disease. Since WAPL and NIPBL have opposite effects on cohesin's association with DNA, we asked whether decreasing Wapl dosage could correct phenotypes seen in Nipbl^+/- mice. Gene expression and embryonic growth are partially corrected, but perinatal lethality is not. Our data are consistent with the view that cohesin dynamics play a key role in regulating gene expression.

The Purkinje-myocardial junction is the anatomic origin of ventricular arrhythmia in CPVT

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an arrhythmia syndrome caused by gene mutations that render RYR2 Ca release channels hyperactive, provoking spontaneous Ca release and delayed afterdepolarizations (DADs). What remains unknown is the cellular source of ventricular arrhythmia triggered by DADs: Purkinje cells in the conduction system or ventricular cardiomyocytes in the working myocardium. To answer this question, we used a genetic approach in mice to knock out cardiac calsequestrin either in Purkinje cells or in ventricular cardiomyocytes. Total loss of calsequestrin in the heart causes a severe CPVT phenotype in mice and humans. We found that loss of calsequestrin only in ventricular myocytes produced a full-blown CPVT phenotype, whereas mice with loss of calsequestrin only in Purkinje cells were comparable to WT mice. Subendocardial chemical ablation or restoration of calsequestrin expression in subendocardial cardiomyocytes neighboring Purkinje cells was sufficient to protect against catecholamine-induced arrhythmias. In silico modeling demonstrated that DADs in ventricular myocardium can trigger full action potentials in the Purkinje fiber, but not vice versa. Hence, ectopic beats in CPVT are likely generated at the Purkinje-myocardial junction via a heretofore unrecognized tissue mechanism, whereby DADs in the ventricular myocardium trigger full action potentials in adjacent Purkinje cells.

The "can do, do do" concept in individuals with chronic obstructive pulmonary disease: an exploration of psychological mechanisms

Background

The “can do, do do” concept aims at identifying subgroups among persons with chronic obstructive pulmonary disease (COPD). Following a two-dimensional categorization, individuals are binarily classified with respect to their levels of physical capacity (“can’t do” or “can do”) and physical activity (“don’t do” or “do do”), resulting in four disjunct quadrants. The approach has been debated recently and the latest articles have concluded that the quadrants should be specifically examined in terms of psychological aspects of physical activity. Therefore, the goal of the present study was to explore the role of psychological variables in physical activity in the context of the “can do, do do” quadrant concept.

Methods

Within the scope of secondary data analyses of the “Stay Active After Rehabilitation” (STAR) randomized controlled trial, a total of 298 COPD rehabilitants of an inpatient pulmonary rehabilitation program were grouped into the suggested quadrants. We set fixed cut-offs at 70% of relative 6-min walking test performances for healthy individuals (physical capacity dimension) and 5.000 steps per day (physical activity dimension). Univariate and multivariate logistic regression analyses served to analyze whether depression scores, fear avoidance behaviors, disease-specific anxiety, self-concordance for physical activity, and five indicators of physical activity-related health competence (PAHCO) effectively discriminated between the “don’t do” and “do do” groups.

Results

Among persons with lower relative physical capacity, depression scores, fear avoidance behaviors, and disease-specific anxiety (univariate case) significantly differentiated between the more and the less active. Among persons with higher relative physical capacity, fear avoidance behaviors, disease-specific anxiety, as well as three PAHCO indicators (physical activity-specific self-efficacy, self-control, and affect regulation) significantly separated the more and the less active. In multivariate analyses, only fear avoidance behaviors and affect regulation discriminated among individuals with better relative physical capacity.

Conclusion

The findings identified important psychological and competence-oriented variables that explain discrepancies in the quadrant concept. Based on this, we discuss implications for physical activity promotion in individuals with COPD. Respiratory research can benefit from future studies complementing the quadrant concept through further behavioral analyses.

Trial registration Clinicaltrials.gov, ID: NCT02966561. Registered 17 November, 2016, https://clinicaltrials.gov/ct2/show/NCT02966561.

Cardiac pathologies in mouse loss of imprinting models are due to misexpression of H19 long noncoding RNA

Maternal loss of imprinting (LOI) at the H19/IGF2 locus results in biallelic IGF2 and reduced H19 expression and is associated with Beckwith–-Wiedemann syndrome (BWS). We use mouse models for LOI to understand the relative importance of Igf2 and H19 mis-expression in BWS phenotypes. Here we focus on cardiovascular phenotypes and show that neonatal cardiomegaly is exclusively dependent on increased Igf2. Circulating IGF2 binds cardiomyocyte receptors to hyperactivate mTOR signaling, resulting in cellular hyperplasia and hypertrophy. These Igf2-dependent phenotypes are transient: cardiac size returns to normal once Igf2 expression is suppressed postnatally. However, reduced H19 expression is sufficient to cause progressive heart pathologies including fibrosis and reduced ventricular function. In the heart, H19 expression is primarily in endothelial cells (ECs) and regulates EC differentiation both in vivo and in vitro. Finally, we establish novel mouse models to show that cardiac phenotypes depend on H19 lncRNA interactions with Mirlet7 microRNAs.

Paternal bias expression of Igf2as is enhancer-dependent on the imprinting cluster of Igf2, H19 and Nctc1 in muscle cells

Igf2, H19, and Nctc1 are linked co-regulated genes on distal mouse chromosome 7. This locus is an important model both for studying mechanisms of monoallelic expression and for elucidating the role of cis-regulatory elements – enhancers and insulators – in organizing chromatin and gene expression across a large domain. In this study we characterize regulated expression of the Igf2 antisense transcript (Igf2as) in primary muscle cells. We demonstrate that Igf2as is imprinted (expressed only from the paternal chromosome). We also show that Igf2as expression during differentiation follows the same patterns as Igf2 and H19. Moreover, this expression is dependent upon the same shared enhancer element. Thus, our work shows that the imprinted cluster includes Igf2as in addition to H19, Igf2, and Nctc1.

BRD4 directs hematopoietic stem cell development and modulates macrophage inflammatory responses

BRD4 is a BET family protein that binds acetylated histones and regulates transcription. BET/BRD4 inhibitors block blood cancer growth and inflammation and serve as a new therapeutic strategy. However, the biological role of BRD4 in normal hematopoiesis and inflammation is not fully understood. Analysis of Brd4 conditional knockout (KO) mice showed that BRD4 is required for hematopoietic stem cell expansion and progenitor development. Nevertheless, BRD4 played limited roles in macrophage development and inflammatory response to LPS ChIP-seq analysis showed that despite its limited importance, BRD4 broadly occupied the macrophage genome and participated in super-enhancer (SE) formation. Although BRD4 is critical for SE formation in cancer, BRD4 was not required for macrophage SEs, as KO macrophages created alternate, BRD4-less SEs that compensated BRD4 loss. This and additional mechanisms led to the retention of inflammatory responses in macrophages. Our results illustrate a context-dependent role of BRD4 and plasticity of epigenetic regulation.

Conditional ablation and conditional rescue models for Casq2 elucidate the role of development and of cell-type specific expression of Casq2 in the CPVT2 phenotype

Cardiac calsequestrin (Casq2) associates with the ryanodine receptor 2 channel in the junctional sarcoplasmic reticulum to regulate Ca2+ release into the cytoplasm. Patients carrying mutations in CASQ2 display low resting heart rates under basal conditions and stress-induced polymorphic ventricular tachycardia (CPVT). In this study, we generate and characterize novel conditional deletion and conditional rescue mouse models to test the influence of developmental programs on the heart rate and CPVT phenotypes. We also compare the requirements for Casq2 function in the cardiac conduction system (CCS) and in working cardiomyocytes. Our study shows that the CPVT phenotype is dependent upon concurrent loss of Casq2 function in both the CCS and in working cardiomyocytes. Accordingly, restoration of Casq2 in only the CCS prevents CPVT. In addition, occurrence of CPVT is independent of the developmental history of Casq2-deficiency. In contrast, resting heart rate depends upon Casq2 gene activity only in the CCS and upon developmental history. Finally, our data support a model where low basal heart rate is a significant risk factor for CPVT.

In Inflamed Intestinal Tissues and Epithelial Cells, Interleukin 22 Signaling Increases Expression of H19 Long Noncoding RNA, Which Promotes Mucosal Regeneration

BACKGROUND & AIMS

Inflammation affects regeneration of the intestinal epithelia; long noncoding RNAs (lncRNAs) regulate cell functions, such as proliferation, differentiation, and migration. We investigated the mechanisms by which the lncRNA H19, imprinted maternally expressed transcript (H19) regulates regeneration of intestinal epithelium using cell cultures and mouse models of inflammation.

METHODS

We performed RNA-sequencing transcriptome analyses of intestinal tissues from mice with lipopolysaccharide (LPS)-induced sepsis to identify lncRNAs associated with inflammation; findings were confirmed by quantitative real-time polymerase chain reaction and in situ hybridization analyses of intestinal tissues from mice with sepsis or dextran sulfate sodium (DSS)-induced mucosal wound healing and patients with ulcerative colitis compared to healthy individuals (controls). We screened cytokines for their ability to induce expression of H19 in HT-29 cells and intestinal epithelial cells (IECs), and confirmed findings in crypt epithelial organoids derived from mouse small intestine. IECs were incubated with different signal transduction inhibitors and effects on H19 lncRNA levels were measured. We assessed intestinal epithelial proliferation or regeneration in H19ΔEx1/+ mice given LPS or DSS vs wild-type littermates (control mice). H19 was overexpressed in IECs using lentiviral vectors and cell proliferation was measured. We performed RNA antisense purification, RNA immunoprecipitation, and luciferase reporter assays to study functions of H19 in IECs.

RESULTS

In RNA-sequencing transcriptome analysis of lncRNA expression in intestinal tissues from mice, we found that levels of H19 lncRNA changed significantly with LPS exposure. Levels of H19 lncRNA increased in intestinal tissues of patients with ulcerative colitis, mice with LPS-induced and polymicrobial sepsis, or mice with DSS-induced colitis, compared with controls. Increased H19 lncRNA localized to epithelial cells in the intestine, regardless of Lgr5 messenger RNA expression. Exposure of IECs to interleukin 22 (IL22) increased levels of H19 lncRNA with time and dose, which required STAT3 and protein kinase A activity. IL22 induced expression of H19 in mouse intestinal epithelial organoids within 6 hours. Exposure to IL22 increased growth of intestinal epithelial organoids derived from control mice, but not H19ΔEx1/+ mice. Overexpression of H19 in HT-29 cells increased their proliferation. Intestinal mucosa healed more slowly after withdrawal of DSS from H19ΔEx1/+ mice vs control mice. Crypt epithelial cells from H19ΔEx1/+ mice proliferated more slowly than those from control mice after exposure to LPS. H19 lncRNA bound to p53 and microRNAs that inhibit cell proliferation, including microRNA 34a and let-7; H19 lncRNA binding blocked their function, leading to increased expression of genes that promote regeneration of the epithelium.

CONCLUSIONS

The level of lncRNA H19 is increased in inflamed intestinal tissues from mice and patients. The inflammatory cytokine IL22 induces expression of H19 in IECs, which is required for intestinal epithelial proliferation and mucosal healing. H19 lncRNA appears to inhibit p53 protein and microRNA 34a and let-7 to promote proliferation of IECs and epithelial regeneration.

Circular RNAs and competing endogenous RNA (ceRNA) networks

In recent years, advances in bioinformatics approaches have allowed a systematic characterization of circular RNAs (circRNAs) across a variety of cell types. Demonstration of cell type specificity, regulated expression, and conservation between species all suggest that circRNAs have functional importance. Especially, investigators have begun focusing on the possibility that circRNAs operate as part of competing endogenous RNA (ceRNA) regulatory networks that are proposed to play critical roles in normal development and in pathologic conditions like cancer.

A randomized study to evaluate the effect of exercise on fatigue in people with relapsing-remitting multiple sclerosis treated with fingolimod

Background

Fatigue is a major symptom of multiple sclerosis (MS) in patients, and it has been shown to improve with physical exercise. Although fingolimod might lessen fatigue, it is unclear how patients treated with fingolimod react to physical activity regarding fatigue.

Objective

This study evaluated the effect of an exercise intervention on fatigue in relapsing–remitting MS patients receiving fingolimod.

Methods

People with MS (PwMS) were randomized to either a structured internet-based exercise program (e-training) or no e-training intervention. The primary endpoint was the change in the Modified Fatigue Impact Scale (mFIS) after six months.

Results

The primary analysis showed no statistically significant difference between groups in the mFIS change. Subgroup analyses revealed a beneficial effect of physical exercise for PwMS with low aerobic capacity and with low aerobic capacity plus more severe fatigue. The incidence of adverse events was similar in both groups. No cardiovascular events were reported. The majority of PwMS were relapse free.

Conclusion

Physical exercise benefits on fatigue may depend on the physical capacity of the patient and requires individualized training. Consistent with previous studies, these results suggest that physical exercise generally does not impose a risk and that this holds true also for patients receiving fingolimod.

Trial registration: ClinicalTrials.gov, NCT01490840.

Loss of imprinting mutations define both distinct and overlapping roles for misexpression of IGF2 and of H19 lncRNA

Imprinted genes occur in discrete clusters that are coordinately regulated by shared DNA elements called Imprinting Control Regions. H19 and Igf2 are linked imprinted genes that play critical roles in development. Loss of imprinting (LOI) at the IGF2/H19 locus on the maternal chromosome is associated with the developmental disorder Beckwith Wiedemann Syndrome (BWS) and with several cancers. Here we use comprehensive genetic and genomic analyses to follow muscle development in a mouse model of BWS to dissect the separate and shared roles for misexpression of Igf2 and H19 in the disease phenotype. We show that LOI results in defects in muscle differentiation and hypertrophy and identify primary downstream targets: Igf2 overexpression results in over-activation of MAPK signaling while loss of H19 lncRNA prevents normal down regulation of p53 activity and therefore results in reduced AKT/mTOR signaling. Moreover, we demonstrate instances where H19 and Igf2 misexpression work separately, cooperatively, and antagonistically to establish the developmental phenotype. This study thus identifies new biochemical roles for the H19 lncRNA and underscores that LOI phenotypes are multigenic so that complex interactions will contribute to disease outcomes.

Making choices-how stochastic decisions determine disease progression

Park and Pfeifer discuss Ginart et al.’s use of RNA FISH to measure allele-specific expression in single cells derived from a mouse model of a human imprinting disorder and their finding that differential methylation at the imprinting control region underlies the observed cell-to-cell variability.

In this issue of Genes & Development, Ginart and colleagues (pp. 567–578) study a mouse model for Russell-Silver syndrome (RSS) and show that similar cells within one individual can display distinct gene expression patterns because of epigenetic marks that are established stochastically during early development. Their results provide an excellent explanation for phenotypes seen in RSS and other imprinting disorders and especially help us understand how patients with similar or even identical genetic mutations can display distinct disease profiles.

Inhibition of Formation of Rev-RRE Complex by Pyronin Y

The interaction of pyronin Y, an RNA intercalating drug, with the binding of Rev protein from human immunodeficiency virus type 1 (HIV-1) to Rev-responsive element (RRE)-containing env RNA was studied. In gel retardation assays, recombinant Rev protein tightly bound to in vitro transcribed RRE RNA. Nitrocellulose-filter-binding studies revealed a dissociation constant of ≈(1–2) = 10−10M (Pfeifer et al., 1991). Pyronin Y efficiently suppressed formation of the Rev-RRE complex. At a concentration of 1 μg ml−1, complex formation was almost completely inhibited. Electron microscopy showed that Rev oligomerizes in the presence of RRE-containing RNA with the formation of short rod-like structures or long filaments, depending on the length of the transcript. Assembly of Rev protein along RRE-containing RNAs was abolished after addition of pyronin Y. Thus pyronin Y represents the first compound described to inhibit Rev-RRE complex formation.

H19ICR mediated transcriptional silencing does not require target promoter methylation

Transcription of the reciprocally imprinted genes Insulin-like growth factor 2 (Igf2) and H19 is orchestrated by the 2.4-kb H19 Imprinting Control Region (H19ICR) located upstream of H19. Three known functions are associated with the H19ICR: (1) it is a germline differentially methylated region, (2) it is a transcriptional insulator, and (3) it is a transcriptional silencer. The molecular mechanisms of the DMR and insulator functions have been well characterized but the basis for the ICR's silencer function is less well understood. In order to study the role the H19ICR intrinsically plays in gene silencing, we transferred the 2.4-kb H19ICR to a heterologous non-imprinted location on chromosome 5, upstream of the alpha fetoprotein (Afp) promoter. Independent of its orientation, the 2.4-kb H19ICR silences transcription from the paternal Afp promoter. Thus silencing is a function intrinsic to this DNA element. Further, ICR mediated silencing is a developmental process that, unexpectedly, does not occur through DNA methylation at the target promoter.

Annexin A1 Deficiency does not Affect Myofiber Repair but Delays Regeneration of Injured Muscles

Repair and regeneration of the injured skeletal myofiber involves fusion of intracellular vesicles with sarcolemma and fusion of the muscle progenitor cells respectively. In vitro experiments have identified involvement of Annexin A1 (Anx A1) in both these fusion processes. To determine if Anx A1 contributes to these processes during muscle repair in vivo, we have assessed muscle growth and repair in Anx A1-deficient mouse (AnxA1-/-). We found that the lack of Anx A1 does not affect the muscle size and repair of myofibers following focal sarcolemmal injury and lengthening contraction injury. However, the lack of Anx A1 delayed muscle regeneration after notexin-induced injury. This delay in muscle regeneration was not caused by a slowdown in proliferation and differentiation of satellite cells. Instead, lack of Anx A1 lowered the proportion of differentiating myoblasts that managed to fuse with the injured myofibers by days 5 and 7 after notexin injury as compared to the wild type (w.t.) mice. Despite this early slowdown in fusion of Anx A1-/- myoblasts, regeneration caught up at later times post injury. These results establish in vivo role of Anx A1 in cell fusion required for myofiber regeneration and not in intracellular vesicle fusion needed for repair of myofiber sarcolemma.

[Sensorimotor Deficits in Functional Ankle Instability]

Lateral ankle sprains are among the most common sports injuries, with a prevalence of 25 to 30 % of all injuries. At least one-third of individuals develop long-term complaints and chronic instabilities at the ankle, which in many cases cannot be attributed to mechanical insufficiencies of the joint. This condition is referred to as functional ankle instability (FAI). Impairments of the sensorimotor control system, such as disturbed proprioception and postural control, as well as reduced muscle strength and reflex activity, have been suggested to contribute to the aetiology of FAI. This review summarises the current body of literature regarding sensorimotor control in individuals with FAI. We discuss the results in the context of current neurophysiological models of the development of functional joint instabilities.

[Acceptance of the Implementation of Standardised Patient Education Programmes by the Multidisciplinary Rehabilitation Team Using the Example of a Back School - A Qualitative Study]

AIM

The transfer of standardised patient education programmes into practice is a complex process with a multitude of influencing factors. Determinants relate among others to the organisation and individuals (e. g., practitioner, patient). Knowledge about individual factors regarding the trainers of patient education programmes in the German rehabilitation system is scarce. The aim of this study is to explore the acceptance of trainers concerning the implementation of a standardised back school and to derive facilitators and barriers to the implementation of patient education programmes.

METHODS

Semi-structured guideline-based interviews were conducted in 10 rehabilitation clinics. The sample consisted of 46 trainers (25 women): 11 physicians, 11 psychologists, 21 physio-/exercise therapists and 3 occupational therapists with a mean age of 41. The opinions of the trainers regarding the central components of back schools in general, their opinions about the new curriculum, their expectations on its implementation, anticipated difficulties with implementation and requests to the project team were explored as indicators for acceptance. The data were analysed with a multi-step qualitative content analysis.

RESULTS

6 main categories comprising 136 subcategories were created and 729 quotations coded. Regarding the central components that should be covered by back schools, back-friendly behaviour was addressed most often. Opinions regarding the new curriculum were mostly positive. Trainers' approval of content and methods was highlighted and the similarity with existing offers in the clinics as well as the structure of the programme were rated positively. The trainers expected an increased patient orientation and personal development as well as a common, coherent language and interdisciplinarity. Difficulties were anticipated regarding time and personnel as well as therapy and appointment planning and also regarding the motivation/acceptance of patients. A wish for communication, education of trainers and feedback was directed at the project team.

CONCLUSION

The study demonstrates high acceptance of programme implementation and central components of modern patient education programmes among trainers. The basis of individual facilitators and barriers has been investigated and might contribute to further development of implementation interventions. Communication and education considering those factors play a central role.

Functional ankle instability as a risk factor for osteoarthritis: using T2-mapping to analyze early cartilage degeneration in the ankle joint of young athletes

OBJECTIVE

The aim of this study was to investigate, using T2-mapping, the impact of functional instability in the ankle joint on the development of early cartilage damage.

METHODS

Ethical approval for this study was provided. Thirty-six volunteers from the university sports program were divided into three groups according to their ankle status: functional ankle instability (FAI, initial ankle sprain with residual instability); ankle sprain Copers (initial sprain, without residual instability); and controls (without a history of ankle injuries). Quantitative T2-mapping magnetic resonance imaging (MRI) was performed at the beginning ('early-unloading') and at the end ('late-unloading') of the MR-examination, with a mean time span of 27 min. Zonal region-of-interest T2-mapping was performed on the talar and tibial cartilage in the deep and superficial layers. The inter-group comparisons of T2-values were analyzed using paired and unpaired t-tests. Statistical analysis of variance was performed.

RESULTS

T2-values showed significant to highly significant differences in 11 of 12 regions throughout the groups. In early-unloading, the FAI-group showed a significant increase in quantitative T2-values in the medial, talar regions (P = 0.008, P = 0.027), whereas the Coper-group showed this enhancement in the central-lateral regions (P = 0.05). Especially the comparison of early-loading to late-unloading values revealed significantly decreasing T2-values over time laterally and significantly increasing T2-values medially in the FAI-group, which were not present in the Coper- or control-group.

CONCLUSION

Functional instability causes unbalanced loading in the ankle joint, resulting in cartilage alterations as assessed by quantitative T2-mapping. This approach can visualize and localize early cartilage abnormalities, possibly enabling specific treatment options to prevent osteoarthritis in young athletes.

The H19 long noncoding RNA gives rise to microRNAs miR-675-3p and miR-675-5p to promote skeletal muscle differentiation and regeneration

The H19 long noncoding RNA is repressed after birth, except in skeletal muscle. Dey et al. discover that H19 exon1 encodes miR-675-3p and miR-675-5p. The inhibition of myogenesis by H19 depletion is rescued by expression of miR-675-3p and miR-675-5p. The abnormal skeletal muscle regeneration in H19-deficient mice is rectified by reintroducing miR-675-3p and miR-675-5p. These miRs target the anti-differentiation Smad transcription factors and the DNA replication initiation factor Cdc6. In summary, H19 gives rise to microRNAs to promote skeletal muscle differentiation and regeneration.

Regulated expression of the H19 long noncoding RNA gene has been well characterized as a paradigm for genomic imprinting, but the H19 RNA's biological function remains largely unclear. H19 is abundantly expressed maternally in embryonic tissues but is strongly repressed after birth, and significant transcription persists only in skeletal muscle. Thus, we examined the role of the H19 RNA in skeletal muscle differentiation and regeneration. Knockdown of H19 RNA in myoblast cells and H19 knockout mouse satellite cells decreases differentiation. H19 exon1 encodes two conserved microRNAs, miR-675-3p and miR-675-5p, both of which are induced during skeletal muscle differentiation. The inhibition of myogenesis by H19 depletion during myoblast differentiation is rescued by exogenous expression of miR-675-3p and miR-675-5p. H19-deficient mice display abnormal skeletal muscle regeneration after injury, which is rectified by reintroduction of miR-675-3p and miR-675-5p. miR-675-3p and miR-675-5p function by directly targeting and down-regulating the anti-differentiation Smad transcription factors critical for the bone morphogenetic protein (BMP) pathway and the DNA replication initiation factor Cdc6. Therefore, the H19 long noncoding RNA has a critical trans-regulatory function in skeletal muscle differentiation and regeneration that is mediated by the microRNAs encoded within H19.

[Physical activity and exercise recommendations for cancer patients during rehabilitation]

AIM OF THE WORK

Cancer and its commonly required continuous and intensive medical treatment have a profound and lasting effect on patients' physical, functional, emotional and social wellbeing. In this context the positive comprehensive effects of physical exercise interventions increasingly prove to be promising. The aim of this review is to derive physical exercise recommendations for patients with cancer, especially concerning aerobic and resistance training during rehabilitation, based on the current literature. In a second step the 3 main cancer types breast cancer, prostate cancer and colon cancer and their distinctive features will be addressed briefly.

METHODS

A hierarchic literature research was conducted using the medical information portal Medpilot. The evaluation system of the "European Society of Cardiology" was applied in order to evaluate the evidence and compile evidence-based exercise recommendations for patients with cancer.

RESULTS

When summing up the current data, physical exercise proves to be efficient, safe and feasible for patients with cancer. Both aerobic and resistance training have a positive influence on a patient's physical, psychological and social level and should therefore be included in every exercise program.

CONCLUSION

While the evidence for breast cancer and increasingly also for prostate cancer is strong, research in colon cancer, for example, is still sparse. In order to create precise recommendations regarding the ideal exercise type and dose for the different cancer types during various treatment phases further high quality studies are necessary.

The Igf2/H19 muscle enhancer is an active transcriptional complex

In eukaryotic cells, gene expression is mediated by enhancer activation of RNA polymerase at distant promoters. Recently, distinctions between enhancers and promoters have been blurred by the discovery that enhancers are associated with RNA polymerase and are sites of RNA synthesis. Here, we present an analysis of the insulin-like growth factor 2/H19 muscle enhancer. This enhancer includes a short conserved core element that is organized into chromatin typical of mammalian enhancers, binds tissue-specific transcription factors and functions on its own in vitro to activate promoter transcription. However, in a chromosomal context, this element is not sufficient to activate distant promoters. Instead, enhancer function also requires transcription in cis of a long non-coding RNA, Nctc1. Thus, the insulin-like growth factor 2/H19 enhancer is an active transcriptional complex whose own transcription is essential to its function.

Extracellular annexins and dynamin are important for sequential steps in myoblast fusion

Annexins A1 and A5 are important for initial lipid mixing, whereas subsequent stages of myoblast fusion depend on dynamin, phosphatidylinositol(4,5)bisphosphate, and cellular metabolism.

Myoblast fusion into multinucleated myotubes is a crucial step in skeletal muscle development and regeneration. Here, we accumulated murine myoblasts at the ready-to-fuse stage by blocking formation of early fusion intermediates with lysophosphatidylcholine. Lifting the block allowed us to explore a largely synchronized fusion. We found that initial merger of two cell membranes detected as lipid mixing involved extracellular annexins A1 and A5 acting in a functionally redundant manner. Subsequent stages of myoblast fusion depended on dynamin activity, phosphatidylinositol(4,5)bisphosphate content, and cell metabolism. Uncoupling fusion from preceding stages of myogenesis will help in the analysis of the interplay between protein machines that initiate and complete cell unification and in the identification of additional protein players controlling different fusion stages.

Promoter cross-talk via a shared enhancer explains paternally biased expression of Nctc1 at the Igf2/H19/Nctc1 imprinted locus

Developmentally regulated transcription often depends on physical interactions between distal enhancers and their cognate promoters. Recent genomic analyses suggest that promoter–promoter interactions might play a similarly critical role in organizing the genome and establishing cell-type-specific gene expression. The Igf2/H19 locus has been a valuable model for clarifying the role of long-range interactions between cis-regulatory elements. Imprinted expression of the linked, reciprocally imprinted genes is explained by parent-of-origin-specific chromosomal loop structures between the paternal Igf2 or maternal H19 promoters and their shared tissue-specific enhancer elements. Here, we further analyze these loop structures for their composition and their impact on expression of the linked long non-coding RNA, Nctc1. We show that Nctc1 is co-regulated with Igf2 and H19 and physically interacts with the shared muscle enhancer. In fact, all three co-regulated genes have the potential to interact not only with the shared enhancer but also with each other via their enhancer interactions. Furthermore, developmental and genetic analyses indicate functional significance for these promoter–promoter interactions. Altogether, we present a novel mechanism to explain developmental specific imprinting of Nctc1 and provide new information about enhancer mechanisms and about the role of chromatin domains in establishing gene expression patterns.

Risk-reducing Surgery in Women at Risk for Familial Breast or Ovarian Cancer

An estimated 5 % of breast cancers and 10 % of ovarian cancers may be due to inherited autosomal dominant breast and ovarian cancer alleles BRCA1 und BRCA2. According to population-based studies 1 or 2 women per 1000 carry such a risk allele. The cumulative cancer risk for healthy women with a BRCA-mutation is between 60 and 85 % for breast cancer and between 20 and 60 % for ovarian cancer. Recent studies have reported an increased risk for contralateral breast cancer in women after unilateral breast cancer. Since 1997 the German Cancer Aid has supported an interdisciplinary approach for high-risk women consisting of genetic testing, counselling and prevention in 12 specialised centres. Since 2005 this concept has received additional support from health insurance companies, and results have been assessed with regard to outcomes (e.g. reduced mortality due to more intensive early diagnosis). The number of centres has increased to 15 at various university hospitals. These interdisciplinary centres offer women the opportunity to participate in a structured screening programme for the early diagnosis of breast cancer and provide non-directive counselling on the options for risk-reducing surgery, e.g., prophylactic bilateral salpingo-oophorectomy, prophylactic bilateral mastectomy or contralateral prophylactic mastectomy after unilateral breast cancer. Such surgical interventions can significantly reduce the risk of disease, the respective disease-specific mortality and - particularly prophylactic bilateral salpingo-oophorectomy - total mortality in BRCA-mutation carriers.

An ectopic CTCF-dependent transcriptional insulator influences the choice of Vβ gene segments for VDJ recombination at TCRβ locus

Insulators regulate transcription as they modulate the interactions between enhancers and promoters by organizing the chromatin into distinct domains. To gain better understanding of the nature of chromatin domains defined by insulators, we analyzed the ability of an insulator to interfere in VDJ recombination, a process that is critically dependent on long-range interactions between diverse types of cis-acting DNA elements. A well-established CTCF-dependent transcriptional insulator, H19 imprint control region (H19-ICR), was inserted in the mouse TCRβ locus by genetic manipulation. Analysis of the mutant mice demonstrated that the insulator retains its CTCF and position-dependent enhancer-blocking potential in this heterologous context in vivo. Remarkably, the inserted H19-ICR appears to have the ability to modulate cis-DNA interactions between recombination signal sequence elements of the TCRβ locus leading to a dramatically altered usage of Vβ segments for Vβ-to-DβJβ recombination in the mutant mice. This reveals a novel ability of CTCF to govern long range cis-DNA interactions other than enhancer-promoter interactions and suggests that CTCF-dependent insulators may play a diverse and complex role in genome organization beyond transcriptional control. Our functional analysis of mutated TCRβ locus supports the emerging role of CTCF in governing VDJ recombination.

Accurate measurement of the relative abundance of different DNA species in complex DNA mixtures

A molecular tool that can compare the abundances of different DNA sequences is necessary for comparing intergenic or interspecific gene expression. We devised and verified such a tool using a quantitative competitive polymerase chain reaction approach. For this approach, we adapted a competitor array, an artificially made plasmid DNA in which all the competitor templates for the target DNAs are arranged with a defined ratio, and melting analysis for allele quantitation for accurate quantitation of the fractional ratios of competitively amplified DNAs. Assays on two sets of DNA mixtures with explicitly known compositional structures of the test sequences were performed. The resultant average relative errors of 0.059 and 0.021 emphasize the highly accurate nature of this method. Furthermore, the method's capability of obtaining biological data is demonstrated by the fact that it can illustrate the tissue-specific quantitative expression signatures of the three housekeeping genes G6pdx, Ubc, and Rps27 by using the forms of the relative abundances of their transcripts, and the differential preferences of Igf2 enhancers for each of the multiple Igf2 promoters for the transcription.

[Resource management: ICF-oriented exercise programs for patients with diabetes mellitus type 2. Chronic illnesses and biopsychosocial status]

Common health problems are increasing due to the combination of decreased physical activity demands in everyday life and demographic changes; thus, the importance of exercise therapy is increasing. The incidence and prevalence of today's predominant chronic diseases are directly related to physical activity. However, daily clinical routine does not stay abreast with these changes. The education of physicians, and thus their scope of action, is dominated by biomedical therapy concepts, predominantly drug therapy concepts. Differential and consolidated findings of modern exercise and sport science are astonishingly rare in the counselling and treatment portfolio of medical care. The present disease management program for persons with diabetes mellitus type 2 is a good example. Referring to this background, the authors address the new approach of "ICF-oriented exercise programs and biopsychosocial status." They present resource-related interventional strategies and health care concepts for chronic health disorders like the metabolic syndrome or diabetes mellitus type 2. The relevance and use of active health promotion and care - due to lifestyle- and age-related health problems of the population - will increase in importance and be more commonly recommended.

[Behaviour-orientated exercise therapy--initiating and maintaining a physically active lifestyle]

BACKGROUND

The promotion of a physically active lifestyle has become an important issue in exercise therapy. Exercise-only interventions are frequently used for the rehabilitation of individuals with chronic diseases. These do indeed improve functional and physical performance, but they are not alone sufficient to initiate long lasting changes in physical-activity behaviour. Behaviour-related aspects are rarely integrated into exercise-therapy interventions.

OBJECTIVE

Based on theories of health behaviour change, effective techniques for changing physical-activity behaviour in the context of exercise therapy will be identified.

METHODOLOGY

The starting point is a theory-driven definition of individual behavioural determinants of physical activity and the identification of techniques for influencing the determinants. Subsequently, the potential of the techniques for enhancing physical activity is evaluated. The available evidence was reviewed on the basis of international reviews and control-group studies from the German rehabilitation setting. Finally, recommendations are offered for designing exercise-based interventions to promote participation in and adherence to physical activity.

RESULTS

A total of 28 techniques for the promotion of physical activity behaviour were identified. An approach that proved particularly effective was self-monitoring of physical activity behaviour in a variety of combinations with other techniques, such as contracting, feedback, rewards, generating one's own varied exercise experience, action planning and barrier management.

DISCUSSION

The integration of behaviour-related techniques in the context of exercise therapy interventions shows great promise as a means of initiating and promoting a physically active lifestyle.