Biomedical subjects

Wolfgang Schmid

Publications and source records attributed to Wolfgang Schmid.

13 recordsLinked to original sources

PubMed2006

Preparative isolation of isoflavones from soy and red clover.

Numerous studies have demonstrated the potential of isoflavones occurring in soy (Glycine max L.) and red clover (Trifolium pratense L.) to alleviate climacteric complaints. They have also shown beneficial effects on the cardiovascular system and in the prevention of osteoporosis. As a result, several companies offer nutraceuticals based on soy or red clover extracts. The aim of the present study was the isolation of pure isoflavones on a preparative scale, in order to obtain standards for biological tests and for the quantification of isoflavones in nutraceuticals and foods. High-speed countercurrent chromatography, a special type of liquid-liquid partition chromatography, was applied to the preparative isolation of isoflavones. By using this technique the major monoglucosylated and acetylated isoflavones from soy extracts were obtained after a cleaning-up step on Amberlite XAD-7 material. Furthermore, it was possible to isolate isoflavone aglycones as well as glycosides from a red clover extract. Purity and identity of the isolated isoflavones were confirmed by HPLC with DAD, HPLC-ESI multiple-MS, and NMR spectroscopy.

Chromatography, High Pressure Liquid↗

PubMed2006

Music therapy in the treatment of multiple sclerosis: a comprehensive literature review.

Coping with multiple sclerosis symptoms still remains a challenge for each patient suffering from this chronic inflammatory disease. Therefore, patients often turn to using complementary and alternative medicine (CAM). In this review, the authors aimed to investigate the current state of literature of music therapy in the treatment of multiple sclerosis (MS). Medline, PubMed, Embase, AMED, CAMbase and the Music Therapy World Journal Index were searched for the terms MS and 'music therapy'. In addition, an internet search using Google Scholar was performed. The authors found seven case-reports/series and seven studies on music therapy for MS-patients. Both the case reports and studies presented here are pioneer work. Most of the studies are naturally predominated by the use of qualitative and uncontrolled research designs. Nevertheless, the results of the studies as well as the case reports demonstrate patients' improvement in the domains of self-acceptance, anxiety and depression. The results of the studies as well as the case reports define a sufficient basis for further music therapeutical work as they show a variety of psychosocial and emotional benefits for MS patients.

Humans↗

PubMed2005

Mice with genetically altered glucocorticoid receptor expression show altered sensitivity for stress-induced depressive reactions.

Altered glucocorticoid receptor (GR) signaling is a postulated mechanism for the pathogenesis of major depression. To mimic the human situation of altered GR function claimed for depression, we generated mouse strains that underexpress or overexpress GR, but maintain the regulatory genetic context controlling the GR gene. To achieve this goal, we used the following: (1) GR-heterozygous mutant mice (GR+/-) with a 50% GR gene dose reduction, and (2) mice overexpressing GR by a yeast artificial chromosome resulting in a twofold gene dose elevation. GR+/- mice exhibit normal baseline behaviors but demonstrate increased helplessness after stress exposure, a behavioral correlate of depression in mice. Similar to depressed patients, GR+/- mice have a disinhibited hypothalamic-pituitary-adrenal (HPA) system and a pathological dexamethasone/corticotropin-releasing hormone test. Thus, they represent a murine depression model with good face and construct validity. Overexpression of GR in mice evokes reduced helplessness after stress exposure, and an enhanced HPA system feedback regulation. Therefore, they may represent a model for a stress-resistant strain. These mouse models can now be used to study biological changes underlying the pathogenesis of depressive disorders. As a first potential molecular correlate for such changes, we identified a downregulation of BDNF protein content in the hippocampus of GR+/- mice, which is in agreement with the so-called neurotrophin hypothesis of depression.

Animals↗

PubMed2005

Glucocorticoids inhibit activation-induced cell death (AICD) via direct DNA-dependent repression of the CD95 ligand gene by a glucocorticoid receptor dimer.

Glucocorticoids (GCs) play an important role in the regulation of peripheral T-cell survival. Their molecular mechanism of action and the question of whether they have the ability to inhibit apoptosis in vivo, however, are not fully elucidated. Signal transduction through the glucocorticoid receptor (GR) is complex and involves different pathways. Therefore, we used mice with T-cell-specific inactivation of the GR as well as mice with a function-selective mutation in the GR to determine the signaling mechanism. Evidence is presented for a functional role of direct binding of the GR to 2 negative glucocorticoid regulatory elements (nGREs) in the CD95 (APO-1/Fas) ligand (L) promoter. Binding of GRs to these nGREs reduces activation-induced CD95L expression in T cells. These in vitro results are fully supported by data obtained in vivo. Administration of GCs to mice leads to inhibition of activation-induced cell death (AICD). Thus, GC-mediated inhibition of CD95L expression of activated T cells might contribute to the anti-inflammatory function of steroid drugs.

Animals↗

PubMed2004

Inactivation of the glucocorticoid receptor in hepatocytes leads to fasting hypoglycemia and ameliorates hyperglycemia in streptozotocin-induced diabetes mellitus.

Hepatic glucose production by gluconeogenesis is the main source of glucose during fasting and contributes significantly to hyperglycemia in diabetes mellitus. Accordingly, glucose metabolism is tightly controlled by a variety of hormones including insulin, epinephrine, glucagon, and glucocorticoids (GCs) acting on various cell types. GC effects are mediated by the GC receptor (GR), a ligand-dependent transcription factor, which in the liver and kidney controls gluconeogenesis by induction of gluconeogenic enzymes. To specifically study the contribution of GC on liver carbohydrate metabolism, we generated mice with an inactivation of the GR gene exclusively in hepatocytes using the Cre/loxP technology. Half of the mutant mice die within the first 2 d after birth most likely due to hypoglycemia. Adult mice have normal blood sugar under basal conditions but show hypoglycemia after prolonged starvation due to reduced expression of genes involved in gluconeogenesis. We further demonstrate that absence of GR in hepatocytes limits the development of hyperglycemia in streptozotocin-induced diabetes mellitus probably due to impaired induction of gluconeogenesis. These findings show the essential role of GR function in liver glucose metabolism during fasting and in diabetic mice and indicate that liver-specific GC antagonists could be beneficial in control of diabetic hyperglycemia.

Animals↗

PubMed2004

Glucocorticoid receptor function in hepatocytes is essential to promote postnatal body growth.

Mice carrying a hepatocyte-specific inactivation of the glucorticoid receptor (GR) gene show a dramatic reduction in body size. Growth hormone signaling mediated by the Stat5 transcription factors is impaired. We show that Stat5 proteins physically interact with GR and GR is present in vivo on Stat5-dependent IGF-I and ALS regulatory regions. Interestingly, mice with a DNA-binding-deficient GR but an unaltered ability to interact with STAT5 (GR(dim/dim)) have a normal body size and normal levels of Stat5-dependent mRNAs. These findings strongly support the model in which GR acts as a coactivator for Stat5-dependent transcription upon GH stimulation and reveal an essential role of hepatic GR in the control of body growth.

Animals↗

PubMed2004

CREB function is required for normal thymic cellularity and post-irradiation recovery.

Recent generation of genetically modified Creb1 mutant mice has revealed an important role for CREB (cAMP responsive element binding protein) and the related proteins CREM (cAMP responsive element modulator) and ATF1 (activating transcription factor 1) in cell survival, in agreement with previous studies using overexpression of dominant-negative CREB (dnCREB). CREB and ATF1 are abundantly expressed in T cells and are rapidly activated by phosphorylation when T cells are stimulated through the T cell antigen receptor. We show that T cell-specific loss of CREB in mice, in combination with the loss of ATF1, results in reduced thymic cellularity and delayed thymic recovery following sublethal irradiation but no changes in T cell development or activation. These data show that loss of CREB function has specific effects on thymic T lymphocyte proliferation and homeostasis in vivo.

Activating Transcription Factor 1↗

PubMed2004

High-accuracy amplification of nanogram total RNA amounts for gene profiling.

Microarray-based gene profiling of laser-assisted microdissected tissues or clinical biopsies is still a challenge since the amount of total RNA in such samples is limited and amplification of RNA is mandatory. Representative amplification of mRNA is highly dependent on the reverse transcription reaction, which is error prone, and on the number of amplification cycles. To improve the accuracy of RNA amplification, we optimized, combined, and tested different amplification strategies for Affymetrix oligonucleotide array hybridization. We demonstrate that different protocols differ significantly in quality of mRNA amplification. To demonstrate the accuracy and reproducibility of our optimized protocol in a clinical setting, we analyzed total RNAs from laser-assisted, microdissected cells of human prostate tissues. On the basis of these results, we recommend a standard reverse transcription reaction for small-sample-transcriptome profiling experiments as part of the Minimal Information about a Microarray Experiment (MIAME) set of standards.

Animals↗

PubMed2004

Active music therapy in the treatment of multiple sclerosis patients: a matched control study.

Twenty multiple sclerosis patients (14 female, 6 male) were involved in the study, their ages ranging rom 29 to 47 years. Ten participants formed the therapy group, and 10 the control group. The groups were comparable on the standard neurological classification scheme Expanded Disability Status Scale (EDSS). Exclusion criteria were pregnancy and mental disorders requiring medication. Measurements were taken before therapy began (T1), and subsequently every 3 months (T2-T4). This battery included indicators of clinical depression and anxiety (Beck Depression Inventory and Hospital Anxiety and Depression Scale), a self-acceptance scale (SESA) and a life quality assessment (Hamburg Quality of Life Questionnaire in Multiple Sclerosis). In addition, data were collected on cognitive (MSFC) and functional (EDSS) parameters. Patients in the therapy group received 3 blocks of music therapy in single sessions over the course of the one year project (8 to 10 sessions respectively). The music therapy approach used for this study is based on the Nordoff Robbins approach (Nordoff & Robbins, 1977). There was no significant difference between the music therapy treatment group and the control group. However, the effect size statistics comparing both groups show a medium effect size on the scales measuring self esteem (d = 0.5423, r =.026), depression HAD-D (d = 0.63, r = 0.310) and anxiety HAD-A (d = 0.63, r = 0.310). Significant improvements were found for the therapy group over time (T1-T4) in the scale values of self esteem, depression, and anxiety. Given the stigmatizing effect of a chronic degenerative disease, the positive benefits of music therapy point to a realm of aesthetic considerations in assessing clinical improvement.

Adult↗

PubMed2003

Analysis of CREM-dependent gene expression during mouse spermatogenesis.

The transcription factors CREM, CREB, and ATF-1 constitute a subfamily of beta-Zip transcription factors. Several different kinase cascades regulate the activity of these proteins. The activator splice-isoform CREMtau is specifically and highly expressed in post-meiotic germ cells during mouse spermatogenesis. Male mice lacking CREMtau expression are sterile because of stage-specific arrest of sperm maturation as the spermatids undergo apoptosis. In order to characterize the genes that are controlled by CREM during post-meiotic differentiation of round spermatids, we compared the expression levels of mRNA prepared from testes of wild-type and CREM-deficient mice by suppression subtractive hybridization (SSH) and affymetrix oligonucleotide arrays. A set of 956 unique sequences found in the CREM SSH library was further characterized by generating stage-specific expression profiles during spermatogenesis by hybridization with cDNA from pre-pubertal mice at defined stages of spermatogenesis using nylon DNA arrays. The resulting expression profiles were arranged in a linear order according to similarity in their profile shapes to find co-regulation of functionally related genes. Our data shows that a large number of genes are transcriptionally activated in round spermatids when CREM activity is maximal, including functional groups like transcription factors, proteins involved in signal transduction, and metabolic enzymes, therefore providing novel information of post-meiotic expression of many known as well as novel genes that are either directly or indirectly influenced by CREM expression.

Animals↗

PubMed2002

Disruption of CREB function in brain leads to neurodegeneration.

Control of cellular survival and proliferation is dependent on extracellular signals and is a prerequisite for ordered tissue development and maintenance. Activation of the cAMP responsive element binding protein (CREB) by phosphorylation has been implicated in the survival of mammalian cells. To define its roles in the mouse central nervous system, we disrupted Creb1 in brain of developing and adult mice using the Cre/loxP system. Mice with a Crem(-/-) background and lacking Creb in the central nervous system during development show extensive apoptosis of postmitotic neurons. By contrast, mice in which both Creb1 and Crem are disrupted in the postnatal forebrain show progressive neurodegeneration in the hippocampus and in the dorsolateral striatum. The striatal phenotype is reminiscent of Huntington disease and is consistent with the postulated role of CREB-mediated signaling in polyglutamine-triggered diseases.

Animals↗

PubMed2002

Phosphorylation of CREB Ser142 regulates light-induced phase shifts of the circadian clock.

Biological rhythms are driven in mammals by a central circadian clock located in the suprachiasmatic nucleus (SCN). Light-induced phase shifting of this clock is correlated with phosphorylation of CREB at Ser133 in the SCN. Here, we characterize phosphorylation of CREB at Ser142 and describe its contribution to the entrainment of the clock. In the SCN, light and glutamate strongly induce CREB Ser142 phosphorylation. To determine the physiological relevance of phosphorylation at Ser142, we generated a mouse mutant, CREB(S142A), lacking this phosphorylation site. Light-induced phase shifts of locomotion and expression of c-Fos and mPer1 in the SCN are significantly attenuated in CREB(S142A) mutants. Our findings provide genetic evidence that CREB Ser142 phosphorylation is involved in the entrainment of the mammalian clock and reveal a novel phosphorylation-dependent regulation of CREB activity.

Amino Acid Sequence↗

PubMed2002

Activating transcription factor 1 and CREB are important for cell survival during early mouse development.

Activating transcription factor 1 (ATF1), CREB, and the cyclic AMP (cAMP) response element modulatory protein (CREM), which constitute a subfamily of the basic leucine zipper transcription factors, activate gene expression by binding as homo- or heterodimers to the cAMP response element in regulatory regions of target genes. To investigate the function of ATF1 in vivo, we inactivated the corresponding gene by homologous recombination. In contrast to CREB-deficient mice, which suffer from perinatal lethality, mice lacking ATF1 do not exhibit any discernible phenotypic abnormalities. Since ATF1 and CREB but not CREM are strongly coexpressed during early mouse development, we generated mice deficient for both CREB and ATF1. ATF1(-/-) CREB(-/-) embryos die before implantation due to developmental arrest. ATF1(+/-) CREB(-/-) embryos display a phenotype of embryonic lethality around embryonic day 9.5 due to massive apoptosis. These results indicate that CREB and ATF1 act in concert to mediate signals essential for maintaining cell viability during early embryonic development.

Activating Transcription Factor 1↗