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1.
Exp Astron (Dordr) ; 52(3): 407-437, 2021.
Article in English | MEDLINE | ID: mdl-35153378

ABSTRACT

The proposed THESEUS mission will vastly expand the capabilities to monitor the high-energy sky. It will specifically exploit large samples of gamma-ray bursts to probe the early universe back to the first generation of stars, and to advance multi-messenger astrophysics by detecting and localizing the counterparts of gravitational waves and cosmic neutrino sources. The combination and coordination of these activities with multi-wavelength, multi-messenger facilities expected to be operating in the 2030s will open new avenues of exploration in many areas of astrophysics, cosmology and fundamental physics, thus adding considerable strength to the overall scientific impact of THESEUS and these facilities. We discuss here a number of these powerful synergies and guest observer opportunities.

2.
Psychol Med ; 50(10): 1727-1735, 2020 07.
Article in English | MEDLINE | ID: mdl-31328716

ABSTRACT

BACKGROUND: Previous research showed that automatic emotion regulation is associated with activation of subcortical areas and subsequent feedforward processes to cortical areas. In contrast, cognitive awareness of emotions is mediated by negative feedback from cortical to subcortical areas. Pregenual anterior cingulate cortex (pgACC) is essential in the modulation of both affect and alexithymia. We considered the interplay between these two mechanisms in the pgACC and their relationship with alexithymia. METHOD: In 68 healthy participants (30 women, age = 26.15 ± 4.22) we tested associations of emotion processing and alexithymia with excitation/inhibition (E/I) balance represented as glutamate (Glu)/GABA in the pgACC measured via magnetic resonance spectroscopy in 7 T. RESULTS: Alexithymia was positively correlated with the Glu/GABA ratio (N = 41, p = 0.0393). Further, cognitive self-awareness showed an association with Glu/GABA (N = 52, p = 0.003), which was driven by a correlation with GABA. In contrast, emotion regulation was only correlated with glutamate levels in the pgACC (N = 49, p = 0.008). CONCLUSION: Our results corroborate the importance of the pgACC as a mediating region of alexithymia, reflected in an altered E/I balance. Furthermore, we could specify that this altered balance is linked to a GABA-related modulation of cognitive self-awareness of emotions.


Subject(s)
Affective Symptoms/metabolism , Emotional Regulation/physiology , Gyrus Cinguli/physiology , Inhibition, Psychological , Adult , Brain Mapping , Cognition , Female , Glutamic Acid/analysis , Healthy Volunteers , Humans , Magnetic Resonance Spectroscopy , Male , Young Adult , gamma-Aminobutyric Acid/analysis
3.
Mol Psychiatry ; 22(1): 113-119, 2017 01.
Article in English | MEDLINE | ID: mdl-27184123

ABSTRACT

There is ample evidence that glucose metabolism in the pregenual anterior cingulate cortex (PACC) is increased in major depressive disorder (MDD), whereas it is still unknown whether glucose levels per se are also elevated. Elevated cerebrospinal fluid (CSF) lactate concentrations in MDD patients might indicate that increased glycolytical metabolization of glucose to lactate in astrocytes either alone or in conjunction with mitochondrial dysfunction results in an accumulation of lactate and contributes to pathophysiological mechanisms of MDD. However, until now, no study investigated in vivo PACC glucose and lactate levels in MDD. Proton magnetic resonance spectroscopy was therefore used to test the hypothesis that patients with MDD have increased PACC glucose and lactate levels. In 40 healthy and depressed participants, spectra were acquired from the PACC using a maximum echo J-resolved spectroscopy protocol. Results show significant increases of glucose and lactate in patients, which are also associated with depression severity. These findings indicate impaired brain energy metabolism in MDD with increased fraction of energy utilization via glycolysis and reduced mitochondrial oxidative clearance of lactate. Targeting these metabolic disturbances might affect the balance of metabolic pathways regulating neuronal energetics and result in an attenuation of the elevated basal activity of brain regions within the neural circuitry of depression.


Subject(s)
Depressive Disorder, Major/metabolism , Gyrus Cinguli/metabolism , Adult , Aspartic Acid/metabolism , Brain/metabolism , Energy Metabolism , Female , Glucose/metabolism , Gyrus Cinguli/physiology , Humans , Lactic Acid/metabolism , Magnetic Resonance Spectroscopy/methods , Male , Proton Magnetic Resonance Spectroscopy
4.
J Neurooncol ; 126(1): 185-192, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26476729

ABSTRACT

Survival for glioblastoma (GBM) patients with an unmethyated MGMT promoter in their tumor is generally worse than methylated MGMT tumors, as temozolomide (TMZ) response is limited. How to better treat patients with unmethylated MGMT is unknown. We performed a trial combining erlotinib and bevacizumab in unmethylated GBM patients after completion of radiation (RT) and TMZ. GBM patients with an unmethylated MGMT promoter were trial eligible. Patient received standard RT (60 Gy) and TMZ (75 mg/m2 × 6 weeks) after surgical resection of their tumor. After completion of RT they started erlotinib 150 mg daily and bevacizumab 10 mg/kg every 2 weeks until progression. Imaging evaluations occurred every 8 weeks. The primary endpoint was overall survival. Of the 48 unmethylated patients enrolled, 46 were evaluable (29 men and 17 women); median age was 55.5 years (29-75) and median KPS was 90 (70-100). All patients completed RT with TMZ. The median number of cycles (1 cycle was 4 weeks) was 8 (2-47). Forty-one patients either progressed or died with a median progression free survival of 9.2 months. At a follow up of 33 months the median overall survival was 13.2 months. There were no unexpected toxicities and most observed toxicities were categorized as CTC grade 1 or 2. The combination of erlotinib and bevacizumab is tolerable but did not meet our primary endpoint of increasing survival. Importantly, more trials are needed to find better therapies for GBM patients with an unmethylated MGMT promoter.


Subject(s)
Antineoplastic Agents/therapeutic use , Bevacizumab/therapeutic use , Brain Neoplasms/drug therapy , Erlotinib Hydrochloride/therapeutic use , Glioblastoma/drug therapy , Radiotherapy/adverse effects , Adult , DNA Methylation , DNA Modification Methylases/genetics , Dacarbazine/adverse effects , Dacarbazine/analogs & derivatives , Disease-Free Survival , Female , Humans , Male , Middle Aged , Prognosis , Temozolomide , Treatment Outcome , Young Adult
5.
Clin Oral Investig ; 20(3): 621-9, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26243456

ABSTRACT

OBJECTIVES: The aim of this study was to investigate and compare the changes in human periodontal ligament fibroblasts (HPdLFs) and osteoblasts (HOBs) after the application of compressive force (CF) at two different strengths in vitro. MATERIALS AND METHODS: HPdLF and HOB were exposed to CF with various strengths (5 and 10 %) using a Flexercell Compression Unit for 12 h in vitro. Viability was detected via 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) and apoptosis rate by transferase dUTP nick end labeling (TUNEL) assay. The gene expression of alkaline phosphatase (ALP), osteocalcin (OCN), osteoprotegerin (OPG), and receptor activator of NF-κB ligand (RANKL) was analyzed using reverse transcriptase polymerase chain reaction (RT-PCR). Osteopontin (OPN), matrix metalloproteinase-8 (MMP-8), and tissue inhibition of metalloproteinase-1 (TIMP-1) were quantified by an ELISA. RESULTS: Ten percent CF decreased viability, particularly in HOBs, but did not induce increased apoptosis. ALP gene expression increased the most after 5 % CF in HPdLFs and after 10 % CF in HOB. OCN was not affected by CF in either cell line. The highest RANKL/OPG ratio was measured after 5 % CF in both cell lines. OPN was upregulated in HOB by 5 %. HPdLFs showed an upregulation of MMP-8-synthesis and an increased MMP-8/TIMP-1 ratio. CONCLUSIONS: HOBs have a greater effect on bone remodeling through the upregulation of OPN, whereas HPdLFs facilitate orthodontic tooth movement by influencing the extracellular matrix via the MMP-8/TIMP-1 ratio. CLINICAL RELEVANCE: High CF in orthodontics should be avoided to prevent tissue damage, whereas moderate CF enables active tissue remodeling and tooth movement.


Subject(s)
Fibroblasts/physiology , Osteoblasts/physiology , Periodontal Ligament/cytology , Stress, Mechanical , Apoptosis , Biomechanical Phenomena , Cell Survival , Enzyme-Linked Immunosorbent Assay , Fibroblasts/chemistry , Humans , In Situ Nick-End Labeling , In Vitro Techniques , Osteoblasts/chemistry , Reverse Transcriptase Polymerase Chain Reaction
6.
J Digit Imaging ; 27(3): 351-68, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24197278

ABSTRACT

We present a novel algorithm for the extraction of cavity features on images of human vessels. Fat deposits in the inner wall of such structure introduce artifacts, and regions in the images captured invalidating the usual assumption of an elliptical model which makes the process of extracting the central passage effectively more difficult. Our approach was designed to cope with these challenges and extract the required image features in a fully automated, accurate, and efficient way using two stages: the first allows to determine a bounding segmentation mask to prevent major leakages from pixels of the cavity area by using a circular region fill that operates as a paint brush followed by Principal Component Analysis with auto correction; the second allows to extract a precise cavity enclosure using a micro-dilation filter and an edge-walking scheme. The accuracy of the algorithm has been tested using 30 computed tomography angiography scans of the lower part of the body containing different degrees of inner wall distortion. The results were compared to manual annotations from a specialist resulting in sensitivity around 98 %, false positive rate around 8 %, and positive predictive value around 93 %. The average execution time was 24 and 18 ms on two types of commodity hardware over sections of 15 cm of length (approx. 1 ms per contour) which makes it more than suitable for use in interactive software applications. Reproducibility tests were also carried out with synthetic images showing no variation for the computed diameters against the theoretical measure.


Subject(s)
Angiography/methods , Image Interpretation, Computer-Assisted/methods , Pattern Recognition, Automated/methods , Radiography, Interventional/methods , Algorithms , Artifacts , Humans , Radiographic Image Enhancement , Reproducibility of Results , Sensitivity and Specificity , Software , Tomography, X-Ray Computed/methods
7.
Neuroimage ; 60(4): 2300-8, 2012 May 01.
Article in English | MEDLINE | ID: mdl-22387169

ABSTRACT

The Mismatch Negativity (MMN) component of the event-related potentials is generated when a detectable spectrotemporal feature of the incoming sound does not match the sensory model set up by preceding repeated stimuli. MMN is enhanced at frontocentral scalp sites for deviant words when compared to acoustically similar deviant pseudowords, suggesting that automatic access to long-term memory traces for spoken words contributes to MMN generation. Does spectrotemporal feature matching also drive automatic lexical access? To test this, we recorded human auditory event-related potentials (ERPs) to disyllabic spoken words and pseudowords within a passive oddball paradigm. We first aimed at replicating the word-related MMN enhancement effect for Spanish, thereby adding to the available cross-linguistic evidence (e.g., Finnish, English). We then probed its resilience to spectrotemporal perturbation by inserting short (20 ms) and long (120 ms) silent gaps between first and second syllables of deviant and standard stimuli. A significantly enhanced, frontocentrally distributed MMN to deviant words was found for stimuli with no gap. The long gap yielded no deviant word MMN, showing that prior expectations of word form limits in a given language influence deviance detection processes. Crucially, the insertion of a short gap suppressed deviant word MMN enhancement at frontocentral sites. We propose that spectrotemporal point-wise matching constitutes a core mechanism for fast serial computations in audition and language, bridging sensory and long-term memory systems.


Subject(s)
Evoked Potentials, Auditory/physiology , Memory/physiology , Speech Perception/physiology , Adult , Electroencephalography , Female , Humans , Male , Signal Processing, Computer-Assisted , Young Adult
8.
Amino Acids ; 42(1): 23-38, 2012 Jan.
Article in English | MEDLINE | ID: mdl-20556625

ABSTRACT

Protein damage, caused by radicals, is involved in many diseases and in the aging process. Therefore, it is crucial to understand how protein damage can be limited, repaired or removed. To degrade damaged proteins, several intracellular proteolytic systems exist. One of the most important contributors in intracellular protein degradation of oxidized, aggregated and misfolded proteins is the proteasomal system. The proteasome is not a simple, unregulated structure. It is a more complex proteolytic composition that undergoes diverse regulation in situations of oxidative stress, aging and pathology. In addition to that, numerous studies revealed that the proteasome activity is altered during life time, contributing to the aging process. In addition, in the nervous system, the proteasome plays an important role in maintaining neuronal protein homeostasis. However, alterations in the activity may have an impact on the onset of neurodegenerative diseases. In this review, we discuss what is presently known about protein damage, the role of the proteasome in the degradation of damaged proteins and how the proteasome is regulated. Special emphasis was laid on the role of the proteasome in neurodegenerative diseases.


Subject(s)
Proteasome Endopeptidase Complex/metabolism , Proteins/metabolism , Animals , Humans , Oxidation-Reduction
9.
J Neurooncol ; 107(1): 133-8, 2012 Mar.
Article in English | MEDLINE | ID: mdl-21984064

ABSTRACT

Bevacizumab is frequently used to treat patients with recurrent high-grade glioma (HGG), but responses are generally not durable. Panobinostat is a histone deacetylase inhibitor with anti-neoplastic and anti-angiogenic effects and may work synergistically with VEGF inhibitors. We performed a phase I study to evaluate the safety and tolerability of the combination of orally administered panobinostat with bevacizumab in patients with recurrent HGG. Patients with recurrent HGG were treated on a 3 + 3 trial design. Patients received bevacizumab 10 mg/kg every other week in combination with oral panobinostat. The starting dose of panobinostat was 20 mg three times per week, weekly (cohort 1). Due to concerns for thrombocytopenia with the weekly dosing regimen, the protocol was amended to examine an every other week regimen. Cohort 2 received panobinostat 20 mg three times per week, every other week, and cohort 3 received 30 mg three times per week, every other week. Dose-limiting toxicity during the first 30 days was used to determine the maximum-tolerated dose. Twelve patients (median age 50, median KPS 90) with recurrent HGG were enrolled. One dose-limiting toxicity (DLT) (Grade 3 thrombocytopenia) was observed in cohort 1. No DLTs were observed in cohorts 2 and 3. The following grade 3 toxicities were seen in one patient each: thrombocytopenia, hypophosphatemia, esophageal hemorrhage, and deep venous thrombosis. There were no grade 4 or 5 toxicities. There were three patients with partial responses and seven with stable disease. The recommended doses for further study are oral panobinostat 30 mg three times per week, every other week, in combination with bevacizumab 10 mg/kg every other week. A phase II clinical trial in recurrent HGG is underway.


Subject(s)
Angiogenesis Inhibitors/therapeutic use , Antibodies, Monoclonal, Humanized/therapeutic use , Brain Neoplasms/drug therapy , Glioma/drug therapy , Hydroxamic Acids/therapeutic use , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols , Bevacizumab , Brain Neoplasms/mortality , Brain Neoplasms/pathology , Female , Follow-Up Studies , Glioma/mortality , Glioma/pathology , Humans , Indoles , Male , Maximum Tolerated Dose , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/mortality , Neoplasm Recurrence, Local/pathology , Panobinostat , Survival Rate , Treatment Outcome
10.
Klin Padiatr ; 224(4): 252-5, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22187332

ABSTRACT

Infections with Pseudomonas aeruginosa can cause the hot-foot syndrome, presenting with painful plantar erythematous nodules. Particularly, the mechanically stressed areas of the foot are affected after contact with contaminated water from saunas, swimming pools, hot tubs, etc. We report an outbreak of hot-foot syndrome caused by Pseudomonas in 10 patients. The therapeutic regimens applied reached from local antiseptic therapy to systemic antibiotics.


Subject(s)
Disease Outbreaks , Foot Dermatoses/diagnosis , Pseudomonas Infections/diagnosis , Pseudomonas aeruginosa , Adult , Anti-Infective Agents/administration & dosage , Ceftazidime/administration & dosage , Child , Child, Preschool , Ciprofloxacin/administration & dosage , Diagnosis, Differential , Female , Foot Dermatoses/drug therapy , Foot Dermatoses/etiology , Gentamicins/administration & dosage , Humans , Infusions, Intravenous , Male , Ointments , Povidone-Iodine/administration & dosage , Pseudomonas Infections/drug therapy , Pseudomonas Infections/transmission , Swimming Pools
11.
Schmerz ; 25(5): 534-43, 2011 Sep.
Article in German | MEDLINE | ID: mdl-21909742

ABSTRACT

BACKGROUND: Parents become increasingly more responsible for the postoperative pain management of their children. Useful and valid pain assessments for parents may improve pain measurement. The aim of this study was to evaluate a German version of the parents' postoperative pain measure (PPPM-D). METHODS: After translation of the PPPM into German 52 children between 2 and 12 years of age, undergoing orthopedic and trauma surgery, were included in a prospective study. At least one of the parents completed the PPPM-D on the preoperative day and the day of surgery until postoperative day 5. Both, the children's and infants postoperative pain scale (CHIPPS) for children between 2 and 4 years and the faces pain scale revised (FPS-R) for children between 5 and 12 years were also assessed. Moreover, the acceptance of the PPPM-D by the parents was assessed. RESULTS: The PPPM-D showed satisfactory reliability (Cronbach's α values = 0.77-0.87). Construct validity was demonstrated with strong correlations with the CHIPPS and the FPS-R. Discriminative validity was shown by both statistically and clinically significant differences between minor, medial and major surgeries on the first 3 days after surgery. The examination of sensitivity to change yielded promising results. The PPPM-D was well accepted by the participating parents. CONCLUSIONS: The results of this study provide evidence of the reliability, validity and high acceptance of the PPPM-D as an assessment tool of postoperative pain among children aged 2 through to 12 years of age after orthopedic or trauma surgery.


Subject(s)
Cross-Cultural Comparison , Pain Measurement/methods , Pain, Postoperative/diagnosis , Child , Child, Preschool , Female , Germany , Humans , Male , Orthopedic Procedures , Pain Measurement/statistics & numerical data , Parents , Prospective Studies , Sensitivity and Specificity , Translating , Wounds and Injuries/surgery
12.
J Psychiatr Res ; 136: 402-408, 2021 04.
Article in English | MEDLINE | ID: mdl-33647855

ABSTRACT

Major depressive disorder (MDD) is characterized by heterogeneous cognitive, affective and somatic symptoms. Hence, the investigation of differential treatment effects on these symptoms as well as the identification of symptom specific biomarkers might crucially contribute to the development of individualized treatment strategies. We here aimed to examine symptom specific responses to treatment with ketamine, which repeatedly demonstrated rapid antidepressant effects in severe MDD. Additionally, we investigated working memory (WM) related brain activity associated with changes in distinct symptoms in order to identify specific response predictors. In a sample of 47 MDD patients receiving a single sub-anesthetic dose of ketamine, we applied a three-factor solution of the Beck Depression Inventory (BDI) to detect symptom specific changes 24 h post-infusion. A subsample of 16 patients underwent additional fMRI scanning during an emotional working memory task prior to ketamine treatment. Since functional aberrations in the default mode network (DMN) as well as in the dorsolateral prefrontal cortex (DLPFC) have been associated with impaired cognitive and emotional processing in MDD, we investigated neural activity in these regions. Our results showed that ketamine differentially affects MDD symptoms, with the largest symptom reduction in the cognitive domain. WM related neuroimaging results indicated that a more pronounced effect of ketamine on cognitive symptoms is predicted by lower DMN deactivation and higher DLPFC activation. Findings thereby not only indicate that ketamine's antidepressant efficacy is driven by a pro-cognitive mechanism, but also suggest that this might be mediated by increased potential for adaptive adjustment in the circumscribed brain regions.


Subject(s)
Depressive Disorder, Major , Ketamine , Antidepressive Agents/therapeutic use , Brain Mapping , Cognition , Depressive Disorder, Major/complications , Depressive Disorder, Major/drug therapy , Humans , Ketamine/pharmacology , Ketamine/therapeutic use , Magnetic Resonance Imaging
13.
J Exp Med ; 185(6): 1137-42, 1997 Mar 17.
Article in English | MEDLINE | ID: mdl-9091587

ABSTRACT

Apoptosis is a genetically programmed series of events that results in cell death. As a consequence, it is difficult to identify dominant genes that play a role in this process using genetic selections in conventional cell culture systems. Accordingly, we have established an efficient expression screen to isolate dominant, apoptosis-inducing genes. The assay is based on the apoptotic morphology induced in the human kidney cell line 293 after transient transfection of small plasmid pools from normalized cDNA expression libraries. Using this assay, we isolated a novel isoform of the proto-oncogene Neu differentiation factor (NDF), a ligand for erbB receptor tyrosine kinases. Several lines of experimental evidence indicate that this gene kills in a cell-autonomous fashion and independently of known erbB receptors. This apoptotic property of an NDF isoform is readily contrasted with NDF's transforming potential and might balance the tendency to tumorigenesis in cells that overexpress NDF.


Subject(s)
Apoptosis , Genes, Dominant , Glycoproteins/biosynthesis , Animals , Cell Line , DNA Primers , DNA, Complementary , Glycoproteins/analysis , Glycoproteins/physiology , Humans , Kidney , Mice , Mice, Inbred Strains , Neuregulins , Plasmids , Polymerase Chain Reaction , Proto-Oncogene Mas , Recombinant Proteins/biosynthesis , Transfection
14.
J Exp Med ; 188(8): 1535-9, 1998 Oct 19.
Article in English | MEDLINE | ID: mdl-9782131

ABSTRACT

Neu differentiation factor (NDF, also called neuregulin) is a potent inducer of epithelial cell proliferation and has been shown to induce mammary carcinomas in transgenic mice. Notwithstanding this proliferative effect, we have shown that a novel isoform of NDF can induce apoptosis when overexpressed. Here we report that this property also extends to other NDF isoforms and that the cytoplasmic portion of NDF is largely responsible for the apoptotic effect, whereas the proliferative activity is likely to depend upon the secreted version of NDF. In accordance with these contradictory properties, we find that tumors induced by NDF display extensive apoptosis in vivo. NDF is therefore an oncogene whose deregulation can induce transformation as well as apoptosis.


Subject(s)
Apoptosis/drug effects , Glycoproteins/pharmacology , Oncogenes , Animals , Cricetinae , Neuregulins , Structure-Activity Relationship
15.
J Affect Disord ; 274: 522-534, 2020 09 01.
Article in English | MEDLINE | ID: mdl-32663985

ABSTRACT

BACKGROUND: Depression and the experience of early adversity are associated with impairments in interpersonal and social cognitive functioning. The neural mechanisms involved in these impairments remain insufficiently understood. METHODS: In a sample of 48 depressed and 50 healthy participants, we explored seed-to-voxel functional connectivity (FC) during the recall of formative relationship episodes using functional magnetic resonance imaging. RESULTS: While depressive symptoms were associated with increased FC of brain regions that form an introspective socio-affective network, such as the precuneus, bilateral anterior insula, dorsal anterior cingulate cortex, left amygdala, and medial prefrontal cortex, early adversity linked to decreased FC of brain regions mediating emotion processing such as the bilateral anterior insula and increased FC of the bilateral parahippocampal gyrus. LIMITATIONS: We report both results that are corrected for the number of seeds tested in FC analyses using strict Bonferroni adjustments and unadjusted results as part of an exploratory analysis. DISCUSSION: Our findings suggest that depression and early adversity are associated with differential FC patterns in the brain during the recall of formative relationship episodes. Hyperconnectivity of an introspective socio-affective network associated with depressive symptoms may link to enhanced self-focus and emotional reactivity. Patterns of neural activation associated with early adversity may underpin numbed affective states or enhanced affective memory regulation. Overall, these findings inform about the neural underpinnings of a reflective ability that is predictive of the adaptation to depression and to early adversity and relevant for psychotherapy outcomes.


Subject(s)
Brain Mapping , Depression , Brain/diagnostic imaging , Depression/diagnostic imaging , Humans , Magnetic Resonance Imaging , Mental Recall
16.
J Cell Biol ; 147(7): 1493-502, 1999 Dec 27.
Article in English | MEDLINE | ID: mdl-10613907

ABSTRACT

Here, we describe the isolation of adenine nucleotide translocase-1 (ANT-1) in a screen for dominant, apoptosis-inducing genes. ANT-1 is a component of the mitochondrial permeability transition complex, a protein aggregate connecting the inner with the outer mitochondrial membrane that has recently been implicated in apoptosis. ANT-1 expression led to all features of apoptosis, such as phenotypic alterations, collapse of the mitochondrial membrane potential, cytochrome c release, caspase activation, and DNA degradation. Both point mutations that impair ANT-1 in its known activity to transport ADP and ATP as well as the NH(2)-terminal half of the protein could still induce apoptosis. Interestingly, ANT-2, a highly homologous protein could not lead to cell death, demonstrating the specificity of the signal for apoptosis induction. In contrast to Bax, a proapoptotic Bcl-2 gene, ANT-1 was unable to elicit a form of cell death in yeast. This and the observed repression of apoptosis by the ANT-1-interacting protein cyclophilin D suggest that the suicidal effect of ANT-1 is mediated by specific protein-protein interactions within the permeability transition pore.


Subject(s)
Apoptosis/physiology , Cyclophilins , Intracellular Membranes/enzymology , Mitochondria/enzymology , Mitochondrial ADP, ATP Translocases/physiology , Animals , Apoptosis/drug effects , Cell Death/physiology , Cell Division/physiology , Cell Line , Cricetinae , Peptidyl-Prolyl Isomerase F , Humans , Immunophilins/physiology , Intracellular Membranes/physiology , Membrane Potentials/physiology , Mice , Mitochondria/physiology , Mitochondrial ADP, ATP Translocases/antagonists & inhibitors , Peptide Fragments/physiology , Permeability , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/growth & development
17.
J Cell Biol ; 134(1): 13-23, 1996 Jul.
Article in English | MEDLINE | ID: mdl-8698809

ABSTRACT

Among the many target genes of the transcription factor NF-kappaB are p53 and c-myc, both of which are involved in apoptosis. This prompted us to investigate the role of NF-kappaB in this process. We report that NF-kappaB is potently activated upon serum starvation, a condition leading to apoptosis in 293 cells. Similar to Bcl-2, a transdominant-negative mutant of the NF-kappaB p65 subunit partially inhibited apoptosis, indicating a direct involvement of the transcription factor in induction of cell death. As expected, the p65 mutant suppresses kappaB-dependent gene expression. Surprisingly, transiently or stably overexpressed Bcl-2 had the same effect. The transcription inhibitory activity of the two proteins correlated with their cell death protective potential. Like Bcl-2, the related protein Bcl-xL but not Bcl-xS was able to suppress kB-dependent transcription. Bcl-2 inhibited NF-kappaB activity by an unusual mechanism. It did not prevent the release of IkappaB in the cytoplasm but down-modulated the transactivating potential of nuclear p65. These data show that NF-kappaB can participate in apoptosis. We suggest that at least part of the anti-apoptotic potential of Bcl-2 may be explained from a hitherto undiscovered activity of Bcl-2 in controlling nuclear gene expression.


Subject(s)
Apoptosis , Gene Expression Regulation , NF-kappa B/metabolism , Proto-Oncogene Proteins/metabolism , Animals , Biological Transport , Cell Line , Cell Nucleus/metabolism , Chlorocebus aethiops , Culture Media , DNA-Binding Proteins/metabolism , Humans , Proto-Oncogene Proteins c-bcl-2 , Transcription, Genetic , Transcriptional Activation
18.
J Cell Biol ; 155(4): 531-42, 2001 Nov 12.
Article in English | MEDLINE | ID: mdl-11706048

ABSTRACT

Functional development of mammary epithelium during pregnancy depends on prolactin signaling. However, the underlying molecular and cellular events are not fully understood. We examined the specific contributions of the prolactin receptor (PrlR) and the signal transducers and activators of transcription 5a and 5b (referred to as Stat5) in the formation and differentiation of mammary alveolar epithelium. PrlR- and Stat5-null mammary epithelia were transplanted into wild-type hosts, and pregnancy-mediated development was investigated at a histological and molecular level. Stat5-null mammary epithelium developed ducts but failed to form alveoli, and no milk protein gene expression was observed. In contrast, PrlR-null epithelium formed alveoli-like structures with small open lumina. Electron microscopy revealed undifferentiated features of organelles and a perturbation of cell-cell contacts in PrlR- and Stat5-null epithelia. Expression of NKCC1, an Na-K-Cl cotransporter characteristic for ductal epithelia, and ZO-1, a protein associated with tight junction, were maintained in the alveoli-like structures of PrlR- and Stat5-null epithelia. In contrast, the Na-Pi cotransporter Npt2b, and the gap junction component connexin 32, usually expressed in secretory epithelia, were undetectable in PrlR- and Stat5-null mice. These data demonstrate that signaling via the PrlR and Stat5 is critical for the proliferation and differentiation of mammary alveoli during pregnancy.


Subject(s)
DNA-Binding Proteins/physiology , Mammary Glands, Animal/cytology , Milk Proteins , Pregnancy, Animal , Trans-Activators/physiology , Animals , Cell Differentiation , Cell Division , Connexins/metabolism , Connexins/physiology , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Epidermal Growth Factor/administration & dosage , Epidermal Growth Factor/metabolism , Epithelial Cells/cytology , Female , Growth Hormone/administration & dosage , Growth Hormone/metabolism , Mammary Glands, Animal/anatomy & histology , Mammary Glands, Animal/embryology , Mice , Mice, Inbred C57BL , Mice, Knockout , Pregnancy , Receptors, Prolactin/genetics , Receptors, Prolactin/metabolism , Receptors, Prolactin/physiology , STAT5 Transcription Factor , Sodium-Potassium-Chloride Symporters/metabolism , Solute Carrier Family 12, Member 2 , Trans-Activators/genetics , Trans-Activators/metabolism , Gap Junction beta-1 Protein
19.
Science ; 271(5255): 1601-4, 1996 Mar 15.
Article in English | MEDLINE | ID: mdl-8599120

ABSTRACT

Diffusible factors of several protein families control appendage outgrowth and patterning in both insects and vertebrates. In Drosophila wing development, the gene decapentaplegic (dpp) is expressed along the anteroposterior compartment boundary. Early wingless (wg) expression is involved in setting up the dorsoventral boundary. Interaction between dpp- and wg-expressing cells promotes appendage outgrowth. Here, it is shown that optomotor-blind (omb) expression is required for distal wing development and is controlled by both dpp and wg. Ectopic omb expression can lead to the growth of additional wings. Thus, omb is essential for wing development and is controlled by two signaling pathways.


Subject(s)
DNA-Binding Proteins/genetics , Drosophila Proteins , Drosophila/genetics , Gene Expression Regulation, Developmental , Insect Hormones/genetics , Nerve Tissue Proteins/genetics , Proto-Oncogene Proteins/genetics , T-Box Domain Proteins , Wings, Animal/growth & development , Animals , DNA-Binding Proteins/physiology , Drosophila/growth & development , Genes, Insect , Insect Hormones/physiology , Larva/genetics , Larva/growth & development , Mutation , Nerve Tissue Proteins/physiology , Phenotype , Proto-Oncogene Proteins/physiology , Signal Transduction , Wnt1 Protein
20.
Nucleic Acids Res ; 35(2): 441-54, 2007.
Article in English | MEDLINE | ID: mdl-17169991

ABSTRACT

Ribosomal proteins are assumed to stabilize specific RNA structures and promote compact folding of the large rRNA. The conformational dynamics of the protein between the bound and unbound state play an important role in the binding process. We have studied those dynamical changes in detail for the highly conserved complex between the ribosomal protein L11 and the GTPase region of 23S rRNA. The RNA domain is compactly folded into a well defined tertiary structure, which is further stabilized by the association with the C-terminal domain of the L11 protein (L11(ctd)). In addition, the N-terminal domain of L11 (L11(ntd)) is implicated in the binding of the natural thiazole antibiotic thiostrepton, which disrupts the elongation factor function. We have studied the conformation of the ribosomal protein and its dynamics by NMR in the unbound state, the RNA bound state and in the ternary complex with the RNA and thiostrepton. Our data reveal a rearrangement of the L11(ntd), placing it closer to the RNA after binding of thiostrepton, which may prevent binding of elongation factors. We propose a model for the ternary L11-RNA-thiostrepton complex that is additionally based on interaction data and conformational information of the L11 protein. The model is consistent with earlier findings and provides an explanation for the role of L11(ntd) in elongation factor binding.


Subject(s)
Anti-Bacterial Agents/chemistry , RNA, Ribosomal, 23S/chemistry , Ribosomal Proteins/chemistry , Thiostrepton/chemistry , Anti-Bacterial Agents/metabolism , Binding Sites , Models, Molecular , Nuclear Magnetic Resonance, Biomolecular , Protein Structure, Tertiary , RNA, Ribosomal, 23S/metabolism , Ribosomal Proteins/metabolism , Thiostrepton/metabolism
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