Clinical predictors of negative/equivocal SPECT imaging outcomes in primary hyperparathyroidism: Factors calling for 18F-choline-PET.

PURPOSE: For minimally invasive surgery of parathyroid adenomas, exact localization diagnostics are essential. Main imaging modalities used for diagnostics are sonography, SPECT with/without CT (traditional imaging) and 18F-choline-PET. The aim of our study was to identify predictors for inconclusive SPECT imaging and subsequently determine in which cases 18F-choline-PET is needed. METHODS: Retrospective analysis of 138 patients with histologically confirmed primary hyperparathyroidism (pHPT). After sonography, patients underwent SPECT or SPECT/CT imaging, with subsequent 18F-choline-PET in cases of disconcordant results. Logistic regression analysis was used to identify clinical and laboratory factors predictive for negative SPECT results. RESULTS: Sensitivity rates for sonography, SPECT, SPECT/CT, and choline-PET were 47 %, 49 %, 71.7 %, and 97 %, respectively. Logistic regression revealed lower PTH levels (p < 0.001), presence of structural thyroid disease (p = 0.018), and negative sonography (p < 0.001) as predictive of negative/equivocal SPECT outcome. An additional traditional imaging CT scan to a SPECT enhanced detection odds, as did greater adenoma weight. Urolithiasis, osteoporosis, and calcium values as measurement of activity and duration of disease showed no significant association with the detection rate. Furthermore, our study demonstrated that 18F-choline-PET exhibited remarkable sensitivity in detecting adenomas among patients with negative/equivocal SPECT results. CONCLUSION: Our study reveals potential predictive factors for a negative/equivocal SPECT outcome in pHPT. Identifying these factors might allow minimizing futile SPECT examinations and perhaps encourage timely utilization of 18F-choline-PET imaging. Our study reinforces the clinical significance of 18F-choline-PET, especially in complex cases with disconcordant results by conventional parathyroid imaging methods.

[Hormonal Causes for Excessive Sweating]. / Hormonelle Ursachen des vermehrten Schwitzens.

Hormonal Causes for Excessive Sweating Abstract: Excessive sweating is a frequent symptom in the general practice, but quite a few patients report their sweating problems only when explicitly asked. The differentiation into night sweats on the one hand and general sweating on the other hand can give us first diagnostic hints. Based on their frequency, night sweats should also trigger questions about panic attacks or sleeping disorders. The most frequent hormonal causes for excessive sweating are the menopause and hyperthyroidism. Hypogonadism in the aging male is a rather rare cause for excessive sweating and must be associated with sexual problems and a repeatedly low morning testosterone. This article provides an overview about the most frequent hormonal causes of excessive sweating and the diagnostic approach.

microRNA-501 controls myogenin+/CD74+ myogenic progenitor cells during muscle regeneration.

OBJECTIVE: Skeletal muscle regeneration is markedly impaired during aging. How adult muscle stem cells contribute to this decrease in regenerative capacity is incompletely understood. We investigated mechanisms of age-related changes in myogenic progenitor cells using the tissue-specific microRNA 501. METHODS: Young and old C57Bl/6 mice were used (3 months or 24 months of age, respectively) with or without global or tissue-specific genetic deletion of miR-501. Muscle regeneration was induced using intramuscular cardiotoxin injection or treadmill exercise and analysed using single cell and bulk RNA sequencing, qRT-PCR and immunofluorescence. Muscle fiber damage was assessed with Evan`s blue dye (EBD). In vitro analysis was performed in primary muscle cells obtained from mice and humans. RESULTS: Single cell sequencing revealed myogenic progenitor cells in miR-501 knockout mice at day 6 after muscle injury that are characterized by high levels of myogenin and CD74. In control mice these cells were less in number and already downregulated after day 3 of muscle injury. Muscle from knockout mice had reduced myofiber size and reduced myofiber resilience to injury and exercise. miR-501 elicits this effect by regulating sarcomeric gene expression through its target gene estrogen-related receptor gamma (Esrrg). Importantly, in aged skeletal muscle where miR-501 was significantly downregulated and its target Esrrg significantly upregulated, the number of myog+/CD74+ cells during regeneration was upregulated to similar levels as observed in 501 knockout mice. Moreover, myog+/CD74+-aged skeletal muscle exhibited a similar decrease in the size of newly formed myofibers and increased number of necrotic myofibers after injury as observed in mice lacking miR-501. CONCLUSIONS: miR-501 and Esrrg are regulated in muscle with decreased regenerative capacity and loss of miR-501 is permissive to the appearance of CD74+ myogenic progenitors. Our data uncover a novel link between the metabolic transcription factor Esrrg and sarcomere formation and demonstrate that stem cell heterogeneity in skeletal muscle during aging is under miRNA control. Targeting Esrrg or myog+/CD74+ progenitor cells might improve fiber size and myofiber resilience to exercise in aged skeletal muscle.

Altered Distribution of Unesterified Cholesterol among Lipoprotein Subfractions of Patients with Diabetes Mellitus Type 2.

Biomarkers are important tools to improve the early detection of patients at high risk for developing diabetes as well as the stratification of diabetic patients towards risks of complications. In addition to clinical variables, we analyzed 155 metabolic parameters in plasma samples of 51 healthy volunteers and 66 patients with diabetes using nuclear magnetic resonance (NMR) spectrometry. Upon elastic net analysis with lasso regression, we confirmed the independent associations of diabetes with branched-chain amino acids and lactate (both positive) as well as linoleic acid in plasma and HDL diameter (both inverse). In addition, we found the presence of diabetes independently associated with lower concentrations of free cholesterol in plasma but higher concentrations of free cholesterol in small HDL. Compared to plasmas of non-diabetic controls, plasmas of diabetic subjects contained lower absolute and relative concentrations of free cholesterol in all LDL and HDL subclasses except small HDL but higher absolute and relative concentrations of free cholesterol in all VLDL subclasses (except very small VLDL). These disbalances may reflect disturbances in the transfer of free cholesterol from VLDL to HDL during lipolysis and in the transfer of cell-derived cholesterol from small HDL via larger HDL to LDL.

Activation of PDGF Signaling in the Adult Muscle Stem Cell Niche in Patients With Type 2 Diabetes Mellitus.

CONTEXT: Type 2 diabetes mellitus (T2D) negatively affects muscle mass and function throughout life. Whether adult muscle stem cells contribute to the decrease in muscle health is not clear and insights into the stem cell niche are difficult to obtain. OBJECTIVE: To establish the upstream signaling pathway of microRNA (miR)-501, a marker of activated myogenic progenitor cells, and interrogate this pathway in muscle biopsies from patients with T2D. METHODS: Analysis of primary muscle cell cultures from mice and 4 normoglycemic humans and muscle biopsies from 7 patients with T2D and 7 normoglycemic controls using gene expression, information on histone methylation, peptide screening, and promoter assays. RESULTS: miR-501 shares the promoter of its host gene, isoform 2 of chloride voltage-gated channel 5 (CLCN5-2), and miR-501 expression increases during muscle cell differentiation. We identify platelet-derived growth factor (PDGF) as an upstream regulator of CLCN5-2 and miR-501 via Janus kinase/signal transducer and activator of transcription. Skeletal muscle biopsies from patients with T2D revealed upregulation of PDGF (1.62-fold, P = .002), CLCN5-2 (2.85-fold, P = .03), and miR-501 (1.73-fold, P = .02) compared with normoglycemic controls. In addition, we observed a positive correlation of PDGF and miR-501 in human skeletal muscle (r = 0.542, P = .045, n = 14). CONCLUSIONS: We conclude that paracrine signaling in the adult muscle stem cells niche is activated in T2D. Expression analysis of the PDGF-miR-501 signaling pathway could represent a powerful tool to classify patients in clinical trials that aim to improve muscle health and glucose homeostasis in patients with diabetes.

Prospective Study of Ageing Trajectories in the European DO-HEALTH Study.

INTRODUCTION: Ageing trajectories range from delayed ageing with extended health to accelerated ageing, with an increased risk of frailty. We evaluated the prevalence and prospective change between health states among community-dwelling European older adults. METHODS: This prospective study is a secondary analysis of DO-HEALTH, a randomized trial that included adults aged 70 years and older across 5 European countries. Healthy agers (HA) fulfilled the Nurses' Health Study healthy ageing criteria and accelerated agers were non-HA being at least pre-frail according to the Fried frailty criteria. We assessed the proportion of participants changing between health states over 4 assessments and evaluated the odds of changing to a more favourable category. To increase reliability and avoid regression to the mean, we averaged the first 2 years and compared them to the average of the last 2 years. RESULTS: Of 2,157 participants, 12.4% were excluded for meeting both healthy ageing and pre-frailty criteria simultaneously. Among the remaining 1,889 participants (mean age 75.1 years, 60.9% female), 23.1% were initially HA, 44.4% were non-HA but not pre-frail, and 32.6% were pre-frail or frail. Subsequently, 65.3% remained in the same health state, 12.0% improved to a healthier state, and 22.8% progressed to a less advantageous state. After adjusting for sex, study centre, treatment, and body mass index, each year of age was associated with 6% lower odds of improving health states. Women had 35% higher odds than men of following a disadvantageous trajectory. CONCLUSION: We observed dynamic trajectories of ageing where transitioning to a healthier state became less likely with advancing age and among women.

Growth hormone/IGF-I-dependent signaling restores decreased expression of the myokine SPARC in aged skeletal muscle.

Skeletal muscle exerts many beneficial effects on the human body including the contraction-dependent secretion of peptides termed myokines. We have recently connected the myokine secreted protein acidic and rich in cysteine (SPARC) to the formation of intramuscular adipose tissue (IMAT) in skeletal muscle from aged mice and humans. Here, we searched for inducers of SPARC in order to uncover novel treatment approaches for IMAT. Endurance exercise in mice as well as forskolin treatment in vitro only modestly activated SPARC levels. However, through pharmacological treatments in vitro, we identified IGF-I as a potent inducer of SPARC expression in muscle cells, likely through a direct activation of its promoter via phosphatidylinositol 4,5-bisphospate 3-kinase (PI3K)-dependent signaling. We employed two different mouse models of growth hormone (GH)/IGF-I deficiency to solidify our understanding of the relationship between IGF-I and SPARC in vivo. GH administration robustly increased intramuscular SPARC levels (3.5-fold) in GH releasing hormone receptor-deficient mice and restored low intramuscular SPARC expression in skeletal muscle from aged mice. Intramuscular glycerol injections induced higher levels of adipocyte markers (adiponectin, perilipin) in aged compared to young mice, which was not prevented by GH treatment. Our study provides a roadmap for the study of myokine regulation during aging and demonstrates that the GH/IGF-I axis is critical for SPARC expression in skeletal muscle. Although GH treatment did not prevent IMAT formation in the glycerol model, targeting SPARC by exercise or by activation of IGF-I signaling might offer a novel therapeutic strategy against IMAT formation during aging. KEY MESSAGES : IGF-I regulates the myokine SPARC in muscle cells directly at the promoter level. GH/IGF-I is able to restore the decreased SPARC levels in aged skeletal muscle. The glycerol model induces higher adipocyte markers in aged compared to young muscle. GH treatment does not prevent IMAT formation in the glycerol model.

Reproducible Determination of High-Density Lipoprotein Proteotypes.

High-density lipoprotein (HDL) is a heterogeneous mixture of blood-circulating multimolecular particles containing many different proteins, lipids, and RNAs. Recent advancements in mass spectrometry-based proteotype analysis show promise for the analysis of proteoforms across large patient cohorts. In order to create the required spectral libraries enabling these data-independent acquisition (DIA) strategies, HDL was isolated from the plasma of more than 300 patients with a multiplicity of physiological HDL states. HDL proteome spectral libraries consisting of 296 protein groups and more than 786 peptidoforms were established, and the performance of the DIA strategy was benchmarked for the detection of HDL proteotype differences between healthy individuals and a cohort of patients suffering from diabetes mellitus type 2 and/or coronary heart disease. Bioinformatic interrogation of the data using the generated spectral libraries showed that the DIA approach enabled robust HDL proteotype determination. HDL peptidoform analysis enabled by using spectral libraries allowed for the identification of post-translational modifications, such as in APOA1, which could affect HDL functionality. From a technical point of view, data analysis further shows that protein and peptide quantities are currently more discriminative between different HDL proteotypes than peptidoforms without further enrichment. Together, DIA-based HDL proteotyping enables the robust digitization of HDL proteotypes as a basis for the analysis of larger clinical cohorts.

FGF-2-dependent signaling activated in aged human skeletal muscle promotes intramuscular adipogenesis.

Aged skeletal muscle is markedly affected by fatty muscle infiltration, and strategies to reduce the occurrence of intramuscular adipocytes are urgently needed. Here, we show that fibroblast growth factor-2 (FGF-2) not only stimulates muscle growth but also promotes intramuscular adipogenesis. Using multiple screening assays upstream and downstream of microRNA (miR)-29a signaling, we located the secreted protein and adipogenic inhibitor SPARC to an FGF-2 signaling pathway that is conserved between skeletal muscle cells from mice and humans and that is activated in skeletal muscle of aged mice and humans. FGF-2 induces the miR-29a/SPARC axis through transcriptional activation of FRA-1, which binds and activates an evolutionary conserved AP-1 site element proximal in the miR-29a promoter. Genetic deletions in muscle cells and adeno-associated virus-mediated overexpression of FGF-2 or SPARC in mouse skeletal muscle revealed that this axis regulates differentiation of fibro/adipogenic progenitors in vitro and intramuscular adipose tissue (IMAT) formation in vivo. Skeletal muscle from human donors aged >75 y versus <55 y showed activation of FGF-2-dependent signaling and increased IMAT. Thus, our data highlights a disparate role of FGF-2 in adult skeletal muscle and reveals a pathway to combat fat accumulation in aged human skeletal muscle.

Genetic deletion of microRNA biogenesis in muscle cells reveals a hierarchical non-clustered network that controls focal adhesion signaling during muscle regeneration.

OBJECTIVE: Decreased muscle mass is a major contributor to age-related morbidity, and strategies to improve muscle regeneration during ageing are urgently needed. Our aim was to identify the subset of relevant microRNAs (miRNAs) that partake in critical aspects of muscle cell differentiation, irrespective of computational predictions, genomic clustering or differential expression of the miRNAs. METHODS: miRNA biogenesis was deleted in primary myoblasts using a tamoxifen-inducible CreLox system and combined with an add-back miRNA library screen. RNA-seq experiments, cellular signalling events, and glycogen synthesis, along with miRNA inhibitors, were performed in human primary myoblasts. Muscle regeneration in young and aged mice was assessed using the cardiotoxin (CTX) model. RESULTS: We identified a hierarchical non-clustered miRNA network consisting of highly (miR-29a), moderately (let-7) and mildly active (miR-125b, miR-199a, miR-221) miRNAs that cooperate by directly targeting members of the focal adhesion complex. Through RNA-seq experiments comparing single versus combinatorial inhibition of the miRNAs, we uncovered a fundamental feature of this network, that miRNA activity inversely correlates to miRNA cooperativity. During myoblast differentiation, combinatorial inhibition of the five miRNAs increased activation of focal adhesion kinase (FAK), AKT, and p38 mitogen-activated protein kinase (MAPK), and improved myotube formation and insulin-dependent glycogen synthesis. Moreover, antagonizing the miRNA network in vivo following CTX-induced muscle regeneration enhanced muscle mass and myofiber formation in young and aged mice. CONCLUSION: Our results provide novel insights into the dynamics of miRNA cooperativity and identify a miRNA network as therapeutic target for impaired focal adhesion signalling and muscle regeneration during ageing.

Structure-function relationships of HDL in diabetes and coronary heart disease.

High-density lipoproteins (HDL) contain hundreds of lipid species and proteins and exert many potentially vasoprotective and antidiabetogenic activities on cells. To resolve structure-function-disease relationships of HDL, we characterized HDL of 51 healthy subjects and 98 patients with diabetes (T2DM), coronary heart disease (CHD), or both for protein and lipid composition, as well as functionality in 5 cell types. The integration of 40 clinical characteristics, 34 nuclear magnetic resonance (NMR) features, 182 proteins, 227 lipid species, and 12 functional read-outs by high-dimensional statistical modeling revealed, first, that CHD and T2DM are associated with different changes of HDL in size distribution, protein and lipid composition, and function. Second, different cellular functions of HDL are weakly correlated with each other and determined by different structural components. Cholesterol efflux capacity (CEC) was no proxy of other functions. Third, 3 potentially novel determinants of HDL function were identified and validated by the use of artificially reconstituted HDL, namely the sphingadienine-based sphingomyelin SM 42:3 and glycosylphosphatidylinositol-phospholipase D1 for the ability of HDL to inhibit starvation-induced apoptosis of human aortic endothelial cells and apolipoprotein F for the ability of HDL to promote maximal respiration of brown adipocytes.

Uncoupling protein 1 expression in adipocytes derived from skeletal muscle fibro/adipogenic progenitors is under genetic and hormonal control.

BACKGROUND: Intramuscular fatty infiltration is generally associated with the accumulation of white adipocytes in skeletal muscle and unfavourable metabolic outcomes. It is, however, still unclear whether intramuscular adipocytes could also acquire a brown-like phenotype. Here, we detected intramuscular expression of brown adipocyte markers during fatty infiltration in an obesity-resistant mouse strain and extensively compared the potential of two different stem cell populations residing in skeletal muscle to differentiate into brown-like adipocytes. METHODS: Fatty infiltration was induced using intramuscular glycerol or cardiotoxin injection in the tibialis anterior muscles of young or aged 129S6/SvEvTac (Sv/129) mice or interleukin-6 (IL-6) knockout mice, and the expression of general and brown adipocyte markers was assessed after 4 weeks. Fibro/adipogenic progenitors (FAPs) and myogenic progenitors were prospectively isolated using fluorescence-activated cell sorting from skeletal muscle of male and female C57Bl6/6J and Sv/129 mice, and monoclonal and polyclonal cultures were treated with brown adipogenic medium. Additionally, FAPs were differentiated with medium supplemented or not with triiodothyronine. RESULTS: Although skeletal muscle expression of uncoupling protein 1 (Ucp1) was barely detectable in uninjected tibialis anterior muscle, it was drastically induced following intramuscular adipogenesis in Sv/129 mice and further increased in response to beta 3-adrenergic stimulation. Intramuscular Ucp1 expression did not depend on IL-6 and was preserved in aged skeletal muscle. Myogenic progenitors did not form adipocytes neither in polyclonal nor monoclonal cultures. Fibro/adipogenic progenitors, on the other hand, readily differentiated into brown-like, UCP1+ adipocytes. Uncoupling protein 1 expression in differentiated FAPs was regulated by genetic background, sex, and triiodothyronine treatment independently of adipogenic differentiation levels. CONCLUSIONS: Intramuscular adipogenesis is associated with increased Ucp1 expression in skeletal muscle from obesity-resistant mice. Fibro/adipogenic progenitors provide a likely source for intramuscular adipocytes expressing UCP1 under control of both genetic and hormonal factors. Therefore, FAPs constitute a possible target for therapies aiming at the browning of intramuscular adipose tissue and the metabolic improvement of skeletal muscle affected by fatty infiltration.

Strategies to use microRNAs as therapeutic targets.

MicroRNAs (miRNAs) provide a unique mechanism of gene regulation and play a key role in different pathologies ranging from metabolic diseases to cancer. miRNAs can impact biological function as either suppressors of gene expression when their expression levels are enhanced in a disease state or they can cause upregulation of gene expression when their expression levels are reduced. Therefore both gain- and loss-of- function strategies are needed to fully exploit their therapeutic potential. miRNA research first focused on inhibition of single miRNAs using oligonucleotide inhibitors. However, more recent approaches explore the potential to deliver oligonucleotides to mimic miRNA expression or to employ small molecules to increase or inhibit miRNA function. Although we need to know more about the potential side effects and tissue specific delivery systems, these studies provide grounds to further exploit miRNAs as novel therapeutic targets in the clinic.

MicroRNA deep sequencing in two adult stem cell populations identifies miR-501 as a novel regulator of myosin heavy chain during muscle regeneration.

MicroRNAs (miRNAs) are important regulators of skeletal muscle regeneration, but the underlying mechanisms are still incompletely understood. Here, comparative miRNA sequencing analysis of myogenic progenitor cells (MPs) and non-myogenic fibroblast-adipocyte progenitors (FAPs) during cardiotoxin (CTX)-induced muscle injury uncovered miR-501 as a novel muscle-specific miRNA. miR-501 is an intronic miRNA and its expression levels in MPs correlated with its host gene, chloride channel, voltage-sensitive 5 (Clcn5). Pharmacological inhibition of miR-501 dramatically blunted the induction of embryonic myosin heavy chain (MYH3) and, to a lesser extent, adult myosin isoforms during muscle regeneration, and promoted small-diameter neofibers. An unbiased target identification approach in primary myoblasts validated gigaxonin as a target of miR-501 that mimicked the effect of miR-501 inhibition on MYH3 expression. In the mdx mouse model, which models a pathological disease state, not only was miR-501 induced in regenerating skeletal muscle, but also its serum levels were increased, which correlated with the disease state of the animals. Our results suggest that miR-501 plays a key role in adult muscle regeneration and might serve as a novel serum biomarker for the activation of adult muscle stem cells.

MicroRNA-29a in Adult Muscle Stem Cells Controls Skeletal Muscle Regeneration During Injury and Exercise Downstream of Fibroblast Growth Factor-2.

The expansion of myogenic progenitors (MPs) in the adult muscle stem cell niche is critical for the regeneration of skeletal muscle. Activation of quiescent MPs depends on the dismantling of the basement membrane and increased access to growth factors such as fibroblast growth factor-2 (FGF2). Here, we demonstrate using microRNA (miRNA) profiling in mouse and human myoblasts that the capacity of FGF2 to stimulate myoblast proliferation is mediated by miR-29a. FGF2 induces miR-29a expression and inhibition of miR-29a using pharmacological or genetic deletion decreases myoblast proliferation. Next generation RNA sequencing from miR-29a knockout myoblasts (Pax7(CE/+) ; miR-29a(flox/flox) ) identified members of the basement membrane as the most abundant miR-29a targets. Using gain- and loss-of-function experiments, we confirm that miR-29a coordinately regulates Fbn1, Lamc1, Nid2, Col4a1, Hspg2 and Sparc in myoblasts in vitro and in MPs in vivo. Induction of FGF2 and miR-29a and downregulation of its target genes precedes muscle regeneration during cardiotoxin (CTX)-induced muscle injury. Importantly, MP-specific tamoxifen-induced deletion of miR-29a in adult skeletal muscle decreased the proliferation and formation of newly formed myofibers during both CTX-induced muscle injury and after a single bout of eccentric exercise. Our results identify a novel miRNA-based checkpoint of the basement membrane in the adult muscle stem cell niche. Strategies targeting miR-29a might provide useful clinical approaches to maintain muscle mass in disease states such as ageing that involve aberrant FGF2 signaling.

Growth hormone replacement therapy regulates microRNA-29a and targets involved in insulin resistance.

UNLABELLED: Replacement of growth hormone (GH) in patients suffering from GH deficiency (GHD) offers clinical benefits on body composition, exercise capacity, and skeletal integrity. However, GH replacement therapy (GHRT) is also associated with insulin resistance, but the mechanisms are incompletely understood. We demonstrate that in GH-deficient mice (growth hormone-releasing hormone receptor (Ghrhr)(lit/lit)), insulin resistance after GHRT involves the upregulation of the extracellular matrix (ECM) and the downregulation of microRNA miR-29a in skeletal muscle. Based on RNA deep sequencing of skeletal muscle from GH-treated Ghrhr(lit/lit) mice, we identified several upregulated genes as predicted miR-29a targets that are negative regulators of insulin signaling or profibrotic/proinflammatory components of the ECM. Using gain- and loss-of-function studies, five of these genes were confirmed as endogenous targets of miR-29a in human myotubes (PTEN, COL3A1, FSTL1, SERPINH1, SPARC). In addition, in human myotubes, IGF1, but not GH, downregulated miR-29a expression and upregulated COL3A1. These results were confirmed in a group of GH-deficient patients after 4 months of GHRT. Serum IGF1 increased, skeletal muscle miR-29a decreased, and miR-29a targets were upregulated in patients with a reduced insulin response (homeostatic model assessment of insulin resistance (HOMA-IR)) after GHRT. We conclude that miR-29a could contribute to the metabolic response of muscle tissue to GHRT by regulating ECM components and PTEN. miR-29a and its targets might be valuable biomarkers for muscle metabolism following GH replacement. KEY MESSAGES: GHRT most significantly affects the ECM cluster in skeletal muscle from mice. GHRT downregulates miR-29a and upregulates miR-29a targets in skeletal muscle from mice. PTEN, COL3A1, FSTL1, SERPINH1, and SPARC are endogenous miR-29a targets in human myotubes. IGF1 decreases miR-29a levels in human myotubes. miR-29a and its targets are regulated during GHRT in skeletal muscle from humans.

Alternative nighttime nutrition regimens in glycogen storage disease type I: a controlled crossover study.

BACKGROUND: Traditional approaches for nighttime glycemic control in glycogen storage disease type I (GSDI) include continuous tube feeding, or ingestion of uncooked corn starch (CS) at bedtime. A modified corn starch (MCS) has been shown to prolong euglycemia in some patients. The aim of this study was to evaluate whether stable nighttime glucose control can be achieved with other types of slowly digested carbohydrates in adult GSDI patients. METHODS: In this cross-over study, nocturnal glucose control and fasting times were assessed with three different nocturnal nutrition regimens in five patients, using continuous glucose monitoring (CGMS) in an outpatient everyday life setting. For each patient, continuous glucose profiles were measured after ingestion of (1) CS, (2) MCS or (3) a pasta meal at bedtime, during 5 to 6 consecutive nights for each regimen. RESULTS: Stable nocturnal glucose control was achieved for all patients with a pasta meal, with a mean duration of glycemia >3.5 mmol/l of 7.6 h (range 5.7-10.8), and >4 mmol/l of 7 h (5.2-9.2), similar to CS and MCS. Fasting glucose before breakfast on workdays (after 7.1 ± 0.8 h) was not significantly different between the three interventions (CS 4.1 ± 0.5 mmol/l, MCS 4.6 ± 0.7 mmol/l, pasta 4.3 ± 0.9 mmol/l). During prolonged fasting on weekends, longer duration of normoglycemia was achieved with CS or MCS than with pasta. CONCLUSION: Consumption of cooked pasta is a suitable and more palatable alternative to uncooked corn starch to achieve nighttime glucose control in adult patients with GSDI.

MicroRNA-194 is a target of transcription factor 1 (Tcf1, HNF1α) in adult liver and controls expression of frizzled-6.

UNLABELLED: Transcription factor 1 (Tcf1; hepatocyte nuclear factor 1α [HNF1α]) is critical for hepatocyte development and function. Whether Tcf1 also regulates hepatic microRNAs (miRNAs) has not been investigated yet. Here we analyzed Tcf1-dependent miRNA expression in adult mice in which this transcription factor had been genetically deleted (Tcf1(-/-) ) using miRNA microarray analysis. The miR-192/-194 cluster was markedly down-regulated in liver of Tcf1(-/-) mice. MiR-192/-194 levels were also decreased in two other tissues that express Tcf1, kidney and small intestine, although to a lesser extent than in liver. In order to identify targets of miR-192/-194 in vivo we combined Affymetrix gene analysis of liver in which miR-192/-194 had been silenced or overexpressed, respectively, and tested regulated messenger RNAs (mRNAs) with multiple binding sites for these miRNAs. This approach revealed frizzled-6 (Fzd6) as a robust endogenous target of miR-194. MiR-194 also targets human FZD6 and expression of miR-194 and Fzd6 are inversely correlated in a mouse model of hepatocellular carcinoma (Dgcr8(flox/flox) p53(flox/flox) × Alb-Cre). CONCLUSION: Our results support a role of miR-194 in liver tumorigenesis through its endogenous target Fzd6. These results may have important implications for Tcf1-mediated liver proliferation.

[Diagnosis and therapy of hyperthyreosis]. / Diagnostik und Therapie der Hyperthyreose.

Hyperthyreosis, diabetes and calcium disorders are frequent endocrine diseases that are often encountered by the primary care physician. The diagnosis of hyperthyreosis can be established by many different laboratory and analytical tests. However, the clinical context can often guide a specific diagnostic approach. Graves disease and toxic adenomas are the most frequent causes of hyperthyreosis. Diagnosis of Graves disease is most frequent between age 35 and 60 and about 10-20% of patients show already initially signs of endocrine orbithopathy. Measurement of thyroid stimulating immunoglobulins (TSI) is especially valuable in unclear cases. Toxic adenomas are always diagnosed by thyroid uptake studies. Rare causes of hyperthyreosis include thyreoiditis, which is characterized by transient hyperthyreosis (<2 months), and thyrotoxicosis factitia. Here, we discuss diagnosis and therapy of different causes of hyperthyreosis based on three clinical examples.