1
|
Allam S, Krüger D, Michel K, Schnabl K, Klingenspor M, Schemann M, Annaházi A. Mechanisms involved in the muscle relaxing effects of STW 5 in guinea pig stomach. Neurogastroenterol Motil 2024:e14761. [PMID: 38342975 DOI: 10.1111/nmo.14761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/17/2024] [Accepted: 01/30/2024] [Indexed: 02/13/2024]
Abstract
INTRODUCTION The herbal preparation STW 5 ameliorates functional dyspepsia partly by relaxing smooth muscle of the proximal stomach, thus improving gastric accommodation. We explored the unknown pathways responsible for this effect by testing targets known to modulate gastric smooth muscle relaxation. METHODS STW 5-induced relaxation of smooth muscle strips from guinea pig gastric corpus before and after pharmacological interventions were recorded with force transducers in an organ bath. ORAI1 mRNA expression was tested in the proximal stomach. KEY RESULTS Blockade of Ca2+ -activated K+ and Cl- channels, voltage-gated L- or T-type Ca2+ channels, TRPA1-, TRPV1-, adenosine or 5-HT4 receptors, antagonizing ryanodine receptors, inhibiting cyclooxygenase or sarcoplasmic reticulum calcium ATPase did not affect STW 5-evoked relaxation. Likewise, protein-kinase A or G were not involved. However, the relaxation evoked by STW 5 was significantly reduced by phorbol-12-myristat-13-acetat, an activator of protein-kinase C, by 2- aminoethyldiphenylborinate, an inhibitor of the IP3 receptor-mediated Ca2+ release from the sarcoplasmic reticulum or by SKF-96365, a nonselective store-operated calcium entry (SOCE) blocker. Furthermore, the mixed TRPC3/SOCE inhibitor Pyr3, but not the selective TRPC3 blocker Pyr10, reduced the effect of STW 5. Finally, BTP2, a potent blocker of ORAI-coupled SOCE, almost abolished STW 5-evoked relaxation. Expression of ORAI1 could be demonstrated in the corpus/fundus. CONCLUSIONS & INFERENCES STW 5 inhibited SOCE, most likely ORAI channels, which are modulated by IP3- and PKC-dependent mechanisms. Our findings impact on the design of drugs to induce muscle relaxation and help identify phytochemicals with similar modes of actions to treat gastrointestinal disturbances.
Collapse
Affiliation(s)
- Shady Allam
- Chair of Human Biology, Technical University of Munich, Freising, Germany
- Pharmacology and Toxicology Department, Faculty of Pharmacy, Menoufia University, Shebeen El-Kom, Egypt
| | - Dagmar Krüger
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | - Klaus Michel
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | - Katharina Schnabl
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Martin Klingenspor
- Chair for Molecular Nutritional Medicine, TUM School of Life Sciences, Technical University of Munich, Freising, Germany
| | - Michael Schemann
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | - Anita Annaházi
- Chair of Human Biology, Technical University of Munich, Freising, Germany
- Chair of Zoology, Technical University of Munich, Freising, Germany
| |
Collapse
|
2
|
Elfers K, Schäuffele S, Hoppe S, Michel K, Zeller F, Demir IE, Schemann M, Mazzuoli-Weber G. Distension evoked mucosal secretion in human and porcine colon in vitro. PLoS One 2023; 18:e0282732. [PMID: 37053302 PMCID: PMC10101454 DOI: 10.1371/journal.pone.0282732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 02/20/2023] [Indexed: 04/15/2023] Open
Abstract
It was suggested that intestinal mucosal secretion is enhanced during muscle relaxation and contraction. Mechanisms of mechanically induced secretion have been studied in rodent species. We used voltage clamp Ussing technique to investigate, in human and porcine colonic tissue, secretion evoked by serosal (Pser) or mucosal (Pmuc) pressure application (2-60 mmHg) to induce distension into the mucosal or serosal compartment, respectively. In both species, Pser or Pmuc caused secretion due to Cl- and, in human colon, also HCO3- fluxes. In the human colon, responses were larger in proximal than distal regions. In porcine colon, Pmuc evoked larger responses than Pser whereas the opposite was the case in human colon. In both species, piroxicam revealed a strong prostaglandin (PG) dependent component. Pser and Pmuc induced secretion was tetrodotoxin (TTX) sensitive in porcine colon. In human colon, a TTX sensitive component was only revealed after piroxicam. However, synaptic blockade by ω-conotoxin GVIA reduced the response to mechanical stimuli. Secretion was induced by tensile rather than compressive forces as preventing distension by a filter inhibited the secretion. In conclusion, in both species, distension induced secretion was predominantly mediated by PGs and a rather small nerve dependent response involving mechanosensitive somata and synapses.
Collapse
Affiliation(s)
- Kristin Elfers
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| | | | - Susanne Hoppe
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Klaus Michel
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | | | - Ihsan Ekin Demir
- University Hospital Rechts der Isar, Technical University of Munich, München, Germany
| | - Michael Schemann
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | - Gemma Mazzuoli-Weber
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Hannover, Germany
- Center for Systems Neuroscience (ZSN), Hannover, Germany
| |
Collapse
|
3
|
Michel K, Kuch B, Dengler S, Demir IE, Zeller F, Schemann M. How big is the little brain in the gut? Neuronal numbers in the enteric nervous system of mice, Guinea pig, and human. Neurogastroenterol Motil 2022; 34:e14440. [PMID: 35929768 DOI: 10.1111/nmo.14440] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 05/23/2022] [Accepted: 07/21/2022] [Indexed: 02/08/2023]
Abstract
BACKGROUND Despite numerous studies on the enteric nervous system (ENS), we lack fundamental knowledge on neuronal densities or total neuron numbers in different species. There are more anecdotal than actual figures on nerve counts. METHODS We used standardized preparation techniques and immunohistochemistry with validated panneuronal markers (human or mouse anti-HuD/C) to determine neuronal densities in specimen from the entire gastrointestinal tract of mice, guinea pig, and humans. In parallel, we measured the dimensions of the gastrointestinal regions in mouse and guinea pig. For humans, we had to rely on literature data. KEY RESULTS The average neuronal densities along the gastrointestinal tract were 35,011 ± 25,017 1/cm2 for the myenteric and 16,685 ± 9098 1/cm2 for the submucous plexus in mice, 24,315 ± 16,627 and 11,850 ± 6122 1/cm2 for guinea pig myenteric and submucous plexus, respectively, and 21,698 ± 9492 and 16,367 ± 5655 1/cm2 for human myenteric and submucous plexus, respectively. The total number of neurons in the ENS was 2.6 million for mice, 14.6 million for guinea pig, and 168 million for human. CONCLUSIONS & INFERENCES This study reports the first comprehensive nerve cell count in mice, guinea pig, and human ENS. Neuronal densities were comparable between the three species and the differences in the total numbers of enteric neurons are likely due to body size and intestinal length. The number of enteric neurons is comparable to the number of neurons in the spinal cord for all three species.
Collapse
Affiliation(s)
- Klaus Michel
- Human Biology, Technical University of Munich, Freising, Germany
| | - Birgit Kuch
- Human Biology, Technical University of Munich, Freising, Germany
| | - Sophie Dengler
- Human Biology, Technical University of Munich, Freising, Germany
| | - Ihsan Ekin Demir
- Surgery, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
| | | | - Michael Schemann
- Human Biology, Technical University of Munich, Freising, Germany
| |
Collapse
|
4
|
Annaházi A, Berger TE, Demir IE, Zeller F, Müller M, Anneser M, Skerra A, Michel K, Schemann M. Metabotropic 5-HT receptor-mediated effects in the human submucous plexus. Neurogastroenterol Motil 2022; 34:e14380. [PMID: 35438222 DOI: 10.1111/nmo.14380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 03/04/2022] [Accepted: 03/28/2022] [Indexed: 12/16/2022]
Abstract
BACKGROUND Serotonin (5-HT) is an important mediator in the gastrointestinal tract, acting on different neuronal 5-HT receptors. The ionotropic 5-HT3 receptor mediates immediate but transient spike discharge in human enteric neurons. We studied the role of the metabotropic 5-HT1P , 5-HT4 , and 5-HT7 receptors to activate human submucous neurons. METHODS Neuroimaging using the voltage sensitive dye Di-8-ANEPPS was performed in submucous plexus preparations from human surgical specimens of the small and large intestine. We synthesized a new, stable 5-HT1P agonist, 5-benzyloxyhydrazonoindalpine (5-BOHIP). KEY RESULTS 5-HT evoked a fast and late-onset spike discharge in enteric neurons. The fast component was blocked by the 5-HT3 receptor antagonist cilansetron, while the remaining sustained response was significantly reduced by the 5-HT1P receptor antagonist 5-hydroxytryptophanyl-5-hydroxytryptophan amide (5-HTP-DP). The newly synthesized 5-HT1P agonist 5-BOHIP induced a slowly developing, long-lasting activation of submucous neurons, which was blocked by 5-HTP-DP. We could not demonstrate any 5-HT7 receptor-induced spike discharge based on the lack of response to 5-carboxamidotryptamine. Similarly, the 5-HT4 agonists 5-methoxytryptamine and prucalopride evoked no immediate or late-onset spike discharge. CONCLUSIONS & INFERENCES Our work demonstrated for the first time the presence of functional 5-HT1P receptors on human submucous neurons. Furthermore, we found no evidence for a role of 5-HT4 or 5-HT7 receptors in the postsynaptic activation of human submucous neurons by 5-HT.
Collapse
Affiliation(s)
- Anita Annaházi
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | | | - Ihsan Ekin Demir
- Department of Surgery, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - Florian Zeller
- Department of Surgery, Klinikum Freising, Freising, Germany
| | - Michael Müller
- Chair of Biological Chemistry, Technical University of Munich, Freising, Germany
| | - Markus Anneser
- Chair of Biological Chemistry, Technical University of Munich, Freising, Germany
| | - Arne Skerra
- Chair of Biological Chemistry, Technical University of Munich, Freising, Germany
| | - Klaus Michel
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| | - Michael Schemann
- Chair of Human Biology, Technical University of Munich, Freising, Germany
| |
Collapse
|
5
|
Cuff AR, Demuth OE, Michel K, Otero A, Pintore R, Polet DT, Wiseman ALA, Hutchinson JR. Walking-and Running and Jumping-with Dinosaurs and Their Cousins, Viewed Through the Lens of Evolutionary Biomechanics. Integr Comp Biol 2022; 62:icac049. [PMID: 35595475 DOI: 10.1093/icb/icac049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Archosauria diversified throughout the Triassic Period before experiencing two mass extinctions near its end ∼201 Mya, leaving only the crocodile-lineage (Crocodylomorpha) and bird-lineage (Dinosauria) as survivors; along with the pterosaurian flying reptiles. About 50 years ago, the "locomotor superiority hypothesis" (LSH) proposed that dinosaurs ultimately dominated by the Early Jurassic Period because their locomotion was superior to other archosaurs'. This idea has been debated continuously since, with taxonomic and morphological analyses suggesting dinosaurs were "lucky" rather than surviving due to being biologically superior. However, the LSH has never been tested biomechanically. Here we present integration of experimental data from locomotion in extant archosaurs with inverse and predictive simulations of the same behaviours using musculoskeletal models, showing that we can reliably predict how extant archosaurs walk, run and jump. These simulations have been guiding predictive simulations of extinct archosaurs to estimate how they moved, and we show our progress in that endeavour. The musculoskeletal models used in these simulations can also be used for simpler analyses of form and function such as muscle moment arms, which inform us about more basic biomechanical similarities and differences between archosaurs. Placing all these data into an evolutionary and biomechanical context, we take a fresh look at the LSH as part of a critical review of competing hypotheses for why dinosaurs (and a few other archosaur clades) survived the Late Triassic extinctions. Early dinosaurs had some quantifiable differences in locomotor function and performance vs. some other archosaurs, but other derived dinosaurian features (e.g., metabolic or growth rates, ventilatory abilities) are not necessarily mutually exclusive from the LSH; or maybe even an opportunistic replacement hypothesis; in explaining dinosaurs' success.
Collapse
Affiliation(s)
- A R Cuff
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
- Human Anatomy Resource Centre, University of Liverpool, Liverpool, United Kingdom
| | - O E Demuth
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
- Department of Earth Sciences, University of Cambridge, United Kingdom
| | - K Michel
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
| | - A Otero
- CONICET - División Paleontología de Vertebrados, Facultad de Ciencias Naturales y Museo, Anexo Laboratorios, La Plata, Argentina
| | - R Pintore
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
- Mécanismes adaptatifs et évolution (MECADEV) / UMR 7179, CNRS / Muséum National d'Histoire Naturelle, France
| | - D T Polet
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
| | - A L A Wiseman
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
- McDonald Institute for Archaeological Research, University of Cambridge, United Kingdom
| | - J R Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, United Kingdom
| |
Collapse
|
6
|
Michel K, Krüger D, Schäuffele S, Zeller F, Demir IE, Theisen J, Schemann M. Fast synaptic excitatory neurotransmission in the human submucosal plexus. Neurogastroenterol Motil 2021; 33:e14164. [PMID: 33960578 DOI: 10.1111/nmo.14164] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/25/2021] [Accepted: 04/15/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND Acetylcholine is the main excitatory neurotransmitter in the enteric nervous system (ENS) in all animal models examined so far. However, data for the human ENS is scarce. METHODS We used neuroimaging using voltage and calcium dyes, Ussing chamber, and immunohistochemistry to study fast synaptic neurotransmission in submucosal plexus neurons of the human gut. KEY RESULTS Electrical stimulation of intraganglionic fiber tracts led to fast excitatory postsynaptic potentials (fEPSPs) in 29 submucosal neurons which were all blocked by the nicotinic antagonist hexamethonium. The nicotinic agonist DMPP mimicked the effects of electrical stimulation and had excitatory effects on 56 of 73 neurons. The unselective NMDA antagonist MK-801 blocked fEPSPs in 14 out of 22 neurons as well as nicotine evoked spike discharge. In contrast, the application of NMDA showed only weak effects on excitability or calcium transients. This agreed with the finding that the specific NMDA antagonist D-APV reduced fEPSPs in only 1 out of 40 neurons. Application of AMPA or kainite had no effect in 41 neurons or evoked spike discharge in only one out of 41 neurons, respectively. Immunohistochemistry showed that 98.7 ± 2.4% of all submucosal neurons (n = 6 preparations, 1003 neurons) stained positive for the nicotinic receptor (α1 , α2 or α3 -subunit). Hexamethonium (200 µM) reduced nerve-evoked chloride secretion by 34.3 ± 18.6% (n = 14 patients), whereas D-APV had no effect. CONCLUSION & INFERENCE Acetylcholine is the most important mediator of fast excitatory postsynaptic transmission in human submucous plexus neurons whereas glutamatergic fEPSPs were rarely encountered.
Collapse
Affiliation(s)
- Klaus Michel
- Department of Human Biology, TU München, Freising, Germany
| | - Dagmar Krüger
- Department of Human Biology, TU München, Freising, Germany
| | | | - Florian Zeller
- Department of Surgery, Clinical Center Freising, Freising, Germany
| | | | - Jörg Theisen
- Department of Surgery, Klinikum Landkreis Erding, Erding, Germany
| | | |
Collapse
|
7
|
Schemann M, Landmann M, Kelber O, Ammar RM, Krueger D, Michel K. Effects of the herbal preparation STW 5-II on in vitro muscle activity in the guinea pig stomach. Neurogastroenterol Motil 2021; 33:e13984. [PMID: 32936513 DOI: 10.1111/nmo.13984] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/06/2020] [Accepted: 08/17/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND STW 5 is a combination of nine medicinal herbal extracts and used to treat functional gastrointestinal disorders including functional dyspepsia. It has a region-specific effect by relaxing the proximal and contracting the distal stomach. The research combination STW 5-II (Iberogast® Advance) lacks three herbal extracts but seems clinically as effective as STW 5. However, the action of STW 5-II on gastric motility is unknown. METHODS In vitro circular and longitudinal muscle tone and contractility were recorded from guinea pig gastric fundus and antrum with isometric force transducers. KEY RESULTS STW 5-II decreased concentration-dependently (64-512 µg/ml) the tone of circular and longitudinal muscle strips from the fundus. In contrast, STW 5-II increased concentration-dependently contraction amplitude in antral circular and longitudinal muscle. The effects were region-dependent but comparable in the two muscle layers. Application of 512 µg STW 5 or STW 5-II revealed comparable effects in the fundus and antrum circular and longitudinal muscle strips. CONCLUSIONS AND INTERFERENCES STW 5-II had a region-specific effect and relaxed the proximal stomach but increased the contractility in the antrum. It was as effective as STW 5 which may explain its comparable clinical effects in treating functional dyspepsia. Impaired accommodation may be normalized through relaxation of the fundus, while the motility-promoting effects leading to an increase in antral motility may activate the gastric pump.
Collapse
Affiliation(s)
| | | | - O Kelber
- Bayer Consumer Health, Steigerwald Arzneimittelwerk GmbH, Darmstadt, Germany
| | - Ramy M Ammar
- Bayer Consumer Health, Steigerwald Arzneimittelwerk GmbH, Darmstadt, Germany.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh, Egypt
| | - Dagmar Krueger
- Human Biology, Technical University Munich, Freising, Germany
| | - K Michel
- Human Biology, Technical University Munich, Freising, Germany
| |
Collapse
|
8
|
Krueger D, Schäuffele S, Zeller F, Demir IE, Theisen J, Michel K, Schemann M. Peppermint and caraway oils have muscle inhibitory and pro-secretory activity in the human intestine in vitro. Neurogastroenterol Motil 2020; 32:e13748. [PMID: 31612595 DOI: 10.1111/nmo.13748] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/05/2019] [Accepted: 09/27/2019] [Indexed: 02/08/2023]
Abstract
BACKGROUND Herbal medicinal products with a broad activity spectrum may be promising alternatives to treat functional gastrointestinal disorders (FGD). Menthacarin® is a drug with a fixed combination of peppermint and caraway oils, which is clinically used to treat FGD-associated symptoms. MATERIALS We studied the effects of peppermint and caraway oils on contractile and secretory activity in 255 human small and large intestinal preparations derived from surgical resections (73 patients). Motility was recorded in circular smooth muscle strips and secretion with the Ussing chamber-voltage clamp technique. Electrical field stimulation evoked nerve induced contractile responses. KEY RESULTS: Peppermint and caraway oil concentrations dependently inhibited muscle contractility as indicated by sustained muscle relaxation and decrease in phasic contractility. These effects occurred in small and large intestinal preparations with IC50 values ranging between 17 and 90 µg/mL for peppermint oil and between 7 and 127 µg/mL for caraway oil. Neither peppermint nor caraway oil influenced the nerve evoked contractile response. The inhibition of contractile activity, but not the muscle relaxation, was prevented by the L-type calcium channel activator Bay K8644 but not by the neurotoxin tetrodotoxin. Both peppermint oil and caraway oil increased epithelial secretion, which remained in tetrodotoxin. CONCLUSION & INTERFERENCE The findings revealed a strong muscle inhibitory and pro-secretory action of peppermint and caraway oils at clinically relevant concentrations. Both actions were nerve-independent. The inhibition of contractility was mediated by inhibition of L-type calcium channels. The effects on muscle and epithelial activity may contribute to the beneficial effects observed in patients with FGD.
Collapse
Affiliation(s)
- Dagmar Krueger
- Human Biology, Technical University Munich, Freising, Germany
| | | | - Florian Zeller
- Department of Surgery, Klinikum Freising, Freising, Germany
| | - Ihsan Ekin Demir
- Department of Surgery, Klinikum rechts der Isar, Technical University Munich, Munich, Germany
| | - Jörg Theisen
- Department of Surgery, Klinikum Landkreis Erding, Erding, Germany
| | - Klaus Michel
- Human Biology, Technical University Munich, Freising, Germany
| | | |
Collapse
|
9
|
Abstract
The mosquito immune system has evolved in the presence of continuous encounters with fungi that range from food to foes. Herein, we review the field of mosquito-fungal interactions, providing an overview of current knowledge and topics of interest. Mosquitoes encounter fungi in their aquatic and terrestrial habitats. Mosquito larvae are exposed to fungi on plant detritus, within the water column, and at the water surface. Adult mosquitoes are exposed to fungi during indoor and outdoor resting, blood and sugar feeding, mating, and oviposition. Fungi enter the mosquito body through different routes, including ingestion and through active or passive breaches in the cuticle. Oral uptake of fungi can be beneficial to mosquitoes, as yeasts hold nutritional value and support larval development. However, ingestion of or surface contact with fungal entomopathogens leads to colonization of the mosquito with often lethal consequences to the host. The mosquito immune system recognizes fungi and mounts cellular and humoral immune responses in the hemocoel, and possibly epithelial immune responses in the gut. These responses are regulated transcriptionally through multiple signal transduction pathways. Proteolytic protease cascades provide additional regulation of antifungal immunity. Together, these immune responses provide an efficient barrier to fungal infections, which need to be overcome by entomopathogens. Therefore, fungi constitute an excellent tool to examine the molecular underpinnings of mosquito immunity and to identify novel antifungal peptides. In addition, recent advances in mycobiome analyses can now be used to examine the contribution of fungi to various mosquito traits, including vector competence.
Collapse
Affiliation(s)
- P Tawidian
- Division of Biology, Kansas State University, 267 Chalmers Hall, Manhattan, KS, 66506, USA
| | - V L Rhodes
- Missouri Southern State University, Biology Department, Reynolds Hall 220, 3950 E. Newman Rd., Joplin, MO, 64801-1595, USA
| | - K Michel
- Division of Biology, Kansas State University, 267 Chalmers Hall, Manhattan, KS, 66506, USA.
| |
Collapse
|
10
|
Lütt A, Michel K, Krüger D, Volz MS, Nassir M, Schulz E, Poralla L, Tangermann P, Bojarski C, Höltje M, Teegen B, Stöcker W, Schemann M, Siegmund B, Prüss H. High prevalence and functional effects of serum antineuronal antibodies in patients with gastrointestinal disorders. Neurogastroenterol Motil 2018; 30:e13292. [PMID: 29345029 DOI: 10.1111/nmo.13292] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 12/20/2017] [Indexed: 12/13/2022]
Abstract
BACKGROUND Antineuronal antibodies can be associated with both gastrointestinal (GI) and brain disorders. For example, antibodies against the potassium channel subunit dipeptidyl-peptidase-like protein-6 (DPPX) bind to neurons in the central nervous system (CNS) and myenteric plexus and cause encephalitis, commonly preceded by severe unspecific GI symptoms. We therefore investigated the prevalence of antineuronal antibodies indicative of treatable autoimmune CNS etiologies in GI patients. METHODS Serum samples of 107 patients (Crohn's disease n = 42, ulcerative colitis n = 16, irritable bowel syndrome n = 13, others n = 36) and 44 healthy controls were screened for anti-DPPX and further antineuronal antibodies using immunofluorescence on rat brain and intestine and cell-based assays. Functional effects of high-titer reactive sera were assessed in organ bath and Ussing chamber experiments and compared to non-reactive patient sera. KEY RESULTS Twenty-one of 107 patients (19.6%) had antibodies against the enteric nervous system, and 22 (20.6%) had anti-CNS antibodies, thus significantly exceeding frequencies in healthy controls (4.5% each). Screening on cell-based assays excluded established antienteric antibodies. Antibody-positive sera were not associated with motility effects in organ bath experiments. However, they induced significant, tetrodotoxin (TTX)-insensitive secretion in Ussing chambers compared to antibody-negative sera. CONCLUSIONS & INFERENCES Antineuronal antibodies were significantly more frequent in GI patients and associated with functional effects on bowel secretion. Future studies will determine whether such antibodies indicate patients who might benefit from additional antibody-directed therapies. However, well-characterized encephalitis-related autoantibodies such as against DPPX were not detected, underlining their rarity in routine cohorts.
Collapse
Affiliation(s)
- A Lütt
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany.,Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - K Michel
- Human Biology, Technical University of Munich, Freising, Germany
| | - D Krüger
- Human Biology, Technical University of Munich, Freising, Germany
| | - M S Volz
- Medical Department (Gastroenterology, Infectious Diseases and Rheumatology), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - M Nassir
- Medical Department (Gastroenterology, Infectious Diseases and Rheumatology), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - E Schulz
- Medical Department (Gastroenterology, Infectious Diseases and Rheumatology), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - L Poralla
- Medical Department (Gastroenterology, Infectious Diseases and Rheumatology), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - P Tangermann
- Medical Department (Gastroenterology, Infectious Diseases and Rheumatology), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - C Bojarski
- Medical Department (Gastroenterology, Infectious Diseases and Rheumatology), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - M Höltje
- Institute for Integrative Neuroanatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - B Teegen
- Institute for Experimental Immunology affiliated with Euroimmun, Lübeck, Germany
| | - W Stöcker
- Institute for Experimental Immunology affiliated with Euroimmun, Lübeck, Germany
| | - M Schemann
- Human Biology, Technical University of Munich, Freising, Germany
| | - B Siegmund
- Medical Department (Gastroenterology, Infectious Diseases and Rheumatology), Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - H Prüss
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany.,Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
11
|
Kugler EM, Michel K, Kirchenbüchler D, Dreissen G, Csiszár A, Merkel R, Schemann M, Mazzuoli-Weber G. Sensitivity to Strain and Shear Stress of Isolated Mechanosensitive Enteric Neurons. Neuroscience 2018; 372:213-224. [PMID: 29317262 DOI: 10.1016/j.neuroscience.2017.12.052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 12/20/2017] [Accepted: 12/27/2017] [Indexed: 10/18/2022]
Abstract
Within the enteric nervous system, the neurons in charge to control motility of the gastrointestinal tract reside in a particular location nestled between two perpendicular muscle layers which contract and relax. We used primary cultured myenteric neurons of male guinea pigs to study mechanosensitivity of enteric neurons in isolation. Ultrafast Neuroimaging with a voltage-sensitive dye technique was used to record neuronal activity in response to shear stress and strain. Strain was induced by locally deforming the elastic cell culture substrate next to a neuron. Measurements showed that substrate strain was mostly elongating cells. Shear stress was exerted by hydrodynamic forces in a microchannel. Both stimuli induced excitatory responses. Strain activated 14% of the stimulated myenteric neurons that responded with a spike frequency of 1.9 (0.7/3.2) Hz, whereas shear stress excited only a few neurons (5.6%) with a very low spike frequency of 0 (0/0.6) Hz. Thus, shear stress does not seem to be an adequate stimulus for mechanosensitive enteric neurons (MEN) while strain activates enteric neurons in a relevant manner. Analyzing the adaptation behavior of MEN showed that shear stress activated rapidly/slowly/ultraslowly adapting MEN (2/62/36%) whereas strain only slowly (46%) and ultraslowly (54%) MEN. Paired experiments with strain and normal stress revealed three mechanosensitive enteric neuronal populations: one strain-sensitive (37%), one normal stress-sensitive (17%) and one strain- and stress-sensitive (46%). These results indicate that shear stress does not play a role in the neuronal control of motility but normal stress and strain.
Collapse
Affiliation(s)
- Eva Maria Kugler
- Human Biology, Technische Universität München, Freising-Weihenstephan, 85354, Germany.
| | - Klaus Michel
- Human Biology, Technische Universität München, Freising-Weihenstephan, 85354, Germany.
| | - David Kirchenbüchler
- Institute of Complex Systems - Biomechanics, Research Center Jülich, 52425 Jülich, Germany.
| | - Georg Dreissen
- Institute of Complex Systems - Biomechanics, Research Center Jülich, 52425 Jülich, Germany.
| | - Agnes Csiszár
- Institute of Complex Systems - Biomechanics, Research Center Jülich, 52425 Jülich, Germany.
| | - Rudolf Merkel
- Institute of Complex Systems - Biomechanics, Research Center Jülich, 52425 Jülich, Germany.
| | - Michael Schemann
- Human Biology, Technische Universität München, Freising-Weihenstephan, 85354, Germany.
| | - Gemma Mazzuoli-Weber
- Human Biology, Technische Universität München, Freising-Weihenstephan, 85354, Germany.
| |
Collapse
|
12
|
Ostertag D, Annahazi A, Krueger D, Michel K, Demir IE, Ceyhan GO, Zeller F, Schemann M. Tryptase potentiates enteric nerve activation by histamine and serotonin: Relevance for the effects of mucosal biopsy supernatants from irritable bowel syndrome patients. Neurogastroenterol Motil 2017; 29. [PMID: 28374503 DOI: 10.1111/nmo.13070] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 02/23/2017] [Indexed: 01/02/2023]
Abstract
BACKGROUND We previously showed that mucosal biopsy supernatants from irritable bowel syndrome patients activated neurons despite low concentrations of tryptase, histamine, and serotonin which individually would not cause spike discharge. We studied the potentiating responses between these mediators on excitability of enteric neurons. METHODS Calcium-imaging was performed using the calcium-sensitive dye Fluo-4 AM in human submucous plexus preparations from 45 individuals. Histamine, serotonin, and tryptase were applied alone and in combinations to evaluate nerve activation which was assessed by analyzing increase in intracellular Ca2+ ([Ca2+ ]i ), the proportion of responding neurons and the product of both defined as Ca-neuroindex (NI). Protease activated receptor (PAR) 2 activating peptide, PAR2 antagonist and the serine protease-inhibitor FUT-175 were used to particularly investigate the role of proteases. KEY RESULTS Histamine or serotonin (1 μmol/L each) evoked only few small responses (median NI [25%/75%]: 0 [0/148]; 85 [0/705] respectively). Their combined application evoked statistically similar responses (216 [21/651]). Addition of the PAR2 activator tryptase induced a significantly higher Ca-NI (1401 [867/4075]) compared to individual application of tryptase or to coapplied histamine and serotonin. This synergistic potentiation was neither mimicked by PAR2 activating peptide nor reversed by the PAR2 antagonist GB83, but abolished by FUT-175. CONCLUSIONS & INFERENCES We observed synergistic potentiation between histamine, serotonin, and tryptase in enteric neurons, which is mediated by proteolytic activity rather than PAR2 activation. This explained neuronal activation by a cocktail of these mediators despite their low concentrations and despite a relatively small PAR2-mediated response in human submucous neurons.
Collapse
Affiliation(s)
- D Ostertag
- Human Biology, Technical University of Munich, Freising, Germany
| | - A Annahazi
- Human Biology, Technical University of Munich, Freising, Germany
| | - D Krueger
- Human Biology, Technical University of Munich, Freising, Germany
| | - K Michel
- Human Biology, Technical University of Munich, Freising, Germany
| | - I E Demir
- Department of Surgery, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - G O Ceyhan
- Department of Surgery, Klinikum Rechts der Isar, Technical University of Munich, Munich, Germany
| | - F Zeller
- Department of Surgery, Klinikum Freising, Freising, Germany
| | - M Schemann
- Human Biology, Technical University of Munich, Freising, Germany
| |
Collapse
|
13
|
Baudet E, Gutierrez-Arroyo A, Baillieul M, Charrier J, Němec P, Bodiou L, Lemaitre J, Rinnert E, Michel K, Bureau B, Adam JL, Nazabal V. Development of an evanescent optical integrated sensor in the mid-infrared for detection of pollution in groundwater or seawater. ACTA ACUST UNITED AC 2017. [DOI: 10.1080/20550308.2017.1338211] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- E. Baudet
- Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, Rennes, France
| | | | - M. Baillieul
- Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, Rennes, France
| | - J. Charrier
- FOTON -UMR-CNRS 6082, ENSSAT, Lannion Cedex, France
| | - P. Němec
- Faculty of Chemical Technology, Department of Graphic Arts and Photophysics, University of Pardubice, Pardubice, Czech Republic
| | - L. Bodiou
- FOTON -UMR-CNRS 6082, ENSSAT, Lannion Cedex, France
| | - J. Lemaitre
- FOTON -UMR-CNRS 6082, ENSSAT, Lannion Cedex, France
| | - E. Rinnert
- Laboratoire Détection, Capteurs et Mesures, Dpt. Recherches et Développements Technologiques, IFREMER, Plouzané, France
| | - K. Michel
- BRGM, Direction Eau, Environnement et Ecotechnologies, Unité Bio-Géochimie environnementale et qualité de l’Eau, Orléans, France
| | - B. Bureau
- Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, Rennes, France
| | - J. L. Adam
- Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, Rennes, France
| | - V. Nazabal
- Institut des Sciences Chimiques de Rennes, UMR-CNRS 6226, Equipe Verres et Céramiques, Université de Rennes 1, Rennes, France
| |
Collapse
|
14
|
Pasler M, Michel K, Marrazzo L, Obenland M, Pallotta S, Wirtz H, Lutterbach J. PO-0772: Patient-specific realtime error detection for VMAT based on transmission detector measurements. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31209-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
15
|
Mills MK, Nayduch D, McVey DS, Michel K. Functional Validation of Apoptosis Genes IAP1 and DRONC in Midgut Tissue of the Biting Midge Culicoides sonorensis (Diptera: Ceratopogonidae) by RNAi. J Med Entomol 2017; 54:559-567. [PMID: 28399198 PMCID: PMC5502902 DOI: 10.1093/jme/tjw225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Indexed: 05/02/2023]
Abstract
Culicoides biting midges transmit multiple ruminant viruses, including bluetongue virus and epizootic hemorrhagic disease virus, causing significant economic burden worldwide. To further enhance current control techniques, understanding vector-virus interactions within the midge is critical. We developed previously a double-stranded RNA (dsRNA) delivery method to induce RNA interference (RNAi) for targeted gene knockdown in adult Culicoides sonorensis Wirth & Jones. Here, we confirm the C. sonorensis inhibitor of apoptosis 1 (CsIAP1) as an anti-apoptotic functional ortholog of IAP1 in Drosophila, identify the ortholog of the Drosophila initiator caspase DRONC (CsDRONC), and demonstrate that injection of dsRNA into the hemocoel can be used for targeted knockdown in the midgut in C. sonorensis. We observed CsIAP1 transcript reduction in whole midges, with highest transcript reduction in midgut tissues. IAP1knockdown (kd) resulted in pro-apoptotic caspase activation in midgut tissues. In IAP1kd midges, midgut tissue integrity and size were severely compromised. This phenotype, as well as reduced longevity, was partially reverted by co-RNAi suppression of CsDRONC and CsIAP1. Therefore, RNAi can be directed to the midgut of C. sonorensis, the initial site of virus infection, using dsRNA injection into the hemocoel. In addition, we provide evidence that the core apoptosis pathway is conserved in C. sonorensis and can be experimentally activated in the midgut to reduce longevity in C. sonorensis. This study thus paves the way for future reverse genetic analyses of midgut-virus interactions in C. sonorensis, including the putative antiviral properties of RNAi and apoptosis pathways.
Collapse
Affiliation(s)
- M K Mills
- Division of Biology, Kansas State University, Manhattan, KS 66506 (; )
| | - D Nayduch
- United States Department of Agriculture, Agricultural Research Service Arthropod Borne Animal Disease Research Unit, Manhattan, KS 66502
| | - D S McVey
- United States Department of Agriculture, Agricultural Research Service Arthropod Borne Animal Disease Research Unit, Manhattan, KS 66502
| | - K Michel
- Division of Biology, Kansas State University, Manhattan, KS 66506 (; )
| |
Collapse
|
16
|
Bose N, Ottoson N, Harrison B, Chan A, Bykowski Jonas A, Qiu X, Ma M, Huhn R, Lowe J, Walsh R, Gorden K, Leonardo S, Ertelt K, Danielson M, Michel K, Patchen M, Uhlik M, Iglesias J, Graff J. Anti-beta glucan antibodies represent a mechanism-based biomarker to select patients responsive to the novel immunotherapeutic, Imprime PGG. Eur J Cancer 2016. [DOI: 10.1016/s0959-8049(16)32915-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
17
|
Li Q, Michel K, Annahazi A, Demir IE, Ceyhan GO, Zeller F, Komorowski L, Stöcker W, Beyak MJ, Grundy D, Farrugia G, De Giorgio R, Schemann M. Anti-Hu antibodies activate enteric and sensory neurons. Sci Rep 2016; 6:38216. [PMID: 27905561 PMCID: PMC5131267 DOI: 10.1038/srep38216] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 11/07/2016] [Indexed: 02/07/2023] Open
Abstract
IgG of type 1 anti-neuronal nuclear antibody (ANNA-1, anti-Hu) specificity is a serological marker of paraneoplastic neurological autoimmunity (including enteric/autonomic) usually related to small-cell lung carcinoma. We show here that IgG isolated from such sera and also affinity-purified anti-HuD label enteric neurons and cause an immediate spike discharge in enteric and visceral sensory neurons. Both labelling and activation of enteric neurons was prevented by preincubation with the HuD antigen. Activation of enteric neurons was inhibited by the nicotinic receptor antagonists hexamethonium and dihydro-β-erythroidine and reduced by the P2X antagonist pyridoxal phosphate-6-azo (benzene-2,4-disulfonic acid (PPADS) but not by the 5-HT3 antagonist tropisetron or the N-type Ca-channel blocker ω-Conotoxin GVIA. Ca++ imaging experiments confirmed activation of enteric neurons but not enteric glia. These findings demonstrate a direct excitatory action of ANNA-1, in particular anti-HuD, on visceral sensory and enteric neurons, which involves nicotinic and P2X receptors. The results provide evidence for a novel link between nerve activation and symptom generation in patients with antibody-mediated gut dysfunction.
Collapse
Affiliation(s)
- Qin Li
- Human Biology, Technical University of Munich, Freising, Germany.,Department of Physiology, Shandong University School of Medicine, Jinan, China
| | - Klaus Michel
- Human Biology, Technical University of Munich, Freising, Germany
| | - Anita Annahazi
- Human Biology, Technical University of Munich, Freising, Germany
| | - Ihsan E Demir
- Department of Surgery, Klinikum Rechts der Isar, Technical University of Munich; Munich, Germany
| | - Güralp O Ceyhan
- Department of Surgery, Klinikum Rechts der Isar, Technical University of Munich; Munich, Germany
| | | | - Lars Komorowski
- Institute for Experimental Immunology, Euroimmun AG, Lübeck, Germany
| | - Winfried Stöcker
- Institute for Experimental Immunology, Euroimmun AG, Lübeck, Germany
| | - Michael J Beyak
- GI Diseases Research Unit, Queen's University, Kingston, ON, Canada
| | - David Grundy
- Department of Biomedical Sciences, University of Sheffield, Sheffield, UK
| | | | - Roberto De Giorgio
- Department of Medical and Surgical Sciences and Center for Applied Biomedical Research, University of Bologna, Bologna, Italy
| | - Michael Schemann
- Human Biology, Technical University of Munich, Freising, Germany
| |
Collapse
|
18
|
Michel K, Santella R, Steers J, Sahajpal A, Downey FX, Thohan V, Oaks M. Many de novo donor-specific antibodies recognize β2 -microglobulin-free, but not intact HLA heterodimers. HLA 2016; 87:356-66. [PMID: 27060279 PMCID: PMC5071754 DOI: 10.1111/tan.12775] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/16/2016] [Accepted: 02/24/2016] [Indexed: 11/27/2022]
Abstract
Solid‐phase single antigen bead (SAB) assays are standard of care for detection and identification of donor‐specific antibody (DSA) in patients who receive solid organ transplantation (SOT). While several studies have documented the reproducibility and sensitivity of SAB testing for DSA, there are little data available concerning its specificity. This study describes the identification of antibodies to β2‐microglobulin‐free human leukocyte antigen (β2‐m‐fHLA) heavy chains on SAB arrays and provides a reassessment of the clinical relevance of DSA testing by this platform. Post‐transplant sera from 55 patients who were positive for de novo donor‐specific antibodies on a SAB solid‐phase immunoassay were tested under denaturing conditions in order to identify antibodies reactive with β2‐m‐fHLA or native HLA (nHLA). Antibodies to β2‐m‐fHLA were present in nearly half of patients being monitored in the post‐transplant period. The frequency of antibodies to β2‐m‐fHLA was similar among DSA and HLA antigens that were irrelevant to the transplant (non‐DSA). Among the seven patients with clinical or pathologic antibody‐mediated rejection (AMR), none had antibodies to β2‐m‐fHLA exclusively; thus, the clinical relevance of β2‐m‐fHLA is unclear. Our data suggests that SAB testing produces false positive reactions due to the presence of β2‐m‐fHLA and these can lead to inappropriate assignment of unacceptable antigens during transplant listing and possibly inaccurate identification of DSA in the post‐transplant period.
Collapse
Affiliation(s)
- K Michel
- Transplant Program, Aurora St. Luke's Medical Center, Milwaukee, WI, USA
| | - R Santella
- Transplant Institute, Avera McKennan Hospital and University System, Sioux Falls, SD, USA
| | - J Steers
- Transplant Institute, Avera McKennan Hospital and University System, Sioux Falls, SD, USA
| | - A Sahajpal
- Transplant Program, Aurora St. Luke's Medical Center, Milwaukee, WI, USA
| | - F X Downey
- Transplant Program, Aurora St. Luke's Medical Center, Milwaukee, WI, USA
| | - V Thohan
- Transplant Program, Aurora St. Luke's Medical Center, Milwaukee, WI, USA
| | - M Oaks
- Transplant Program, Aurora St. Luke's Medical Center, Milwaukee, WI, USA
| |
Collapse
|
19
|
Houard A, Jukna V, Point G, André YB, Klingebiel S, Schultze M, Michel K, Metzger T, Mysyrowicz A. Study of filamentation with a high power high repetition rate ps laser at 1.03 µm. Opt Express 2016; 24:7437-7448. [PMID: 27137034 DOI: 10.1364/oe.24.007437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We study the propagation of intense, high repetition rate laser pulses of picosecond duration at 1.03 µm central wavelength through air. Evidence of filamentation is obtained from measurements of the beam profile as a function of distance, from photoemission imaging and from spatially resolved sonometric recordings. Good agreement is found with numerical simulations. Simulations reveal an important self shortening of the pulse duration, suggesting that laser pulses with few optical cycles could be obtained via double filamentation. An important lowering of the voltage required to induce guided electric discharges between charged electrodes is measured at high laser pulse repetition rate.
Collapse
|
20
|
Burón P, Jimenez-Trevino L, Saiz PA, García-Portilla MP, Corcoran P, Carli V, Fekete S, Hadlaczky G, Hegerl U, Michel K, Sarchiapone M, Temnik S, Värnick A, Verbanck P, Wasserman D, Schmidtke A, Bobes J. Reasons for Attempted Suicide in Europe: Prevalence, Associated Factors, and Risk of Repetition. Arch Suicide Res 2016; 20:45-58. [PMID: 26726966 DOI: 10.1080/13811118.2015.1004481] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
To examine the prevalence of specific reasons for attempted suicide, factors associated with them, and whether reasons for attempted suicide influence risk of repetition. As part of the Monitoring Suicide in Europe (MONSUE) project, data on 4,683 suicide attempters from nine European countries were collected. Independence tests were used to study the influence of age, gender, and other factors on reported reasons. We examined risk of repetition using logistic regression analysis. Interpersonal conflict was common for all patients except those widowed, living alone, or retired. Mental health problems were prevalent among over 45 year-olds, patients unable to work, and patients with a history of at least three suicide attempts. Financial difficulties were cited more often by patients who were 45-64 years old, divorced or separated, living with children only, and unemployed. Close bereavement/serious illness and own physical illness were associated with those over 65 years of age. Two reasons for suicide attempt, interpersonal conflict and mental health problems, were associated with increased risk of repetition independent of other factors. Suicide attempters have a multitude of problems of varying prevalence depending on age, gender, and other factors. They present a range of clinical profiles that require a multidisciplinary response.
Collapse
|
21
|
Krueger D, Michel K, Zeller F, Demir IE, Ceyhan GO, Slotta-Huspenina J, Schemann M. Neural influences on human intestinal epithelium in vitro. J Physiol 2015; 594:357-72. [PMID: 26527433 DOI: 10.1113/jp271493] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 10/20/2015] [Indexed: 12/12/2022] Open
Abstract
KEY POINTS We present the first systematic and, up to now, most comprehensive evaluation of the basic features of epithelial functions, such as basal and nerve-evoked secretion, as well as tissue resistance, in over 2200 surgical specimens of human small and large intestine. We found no evidence for impaired nerve-evoked epithelial secretion or tissue resistance with age or disease pathologies (stomach, pancreas or colon cancer, polyps, diverticulitis, stoma reversal). This indicates the validity of future studies on epithelial secretion or resistance that are based on data from a variety of surgical specimens. ACh mainly mediated nerve-evoked and basal secretion in the small intestine, whereas vasoactive intestinal peptide and nitric oxide were the primary pro-secretory transmitters in the large intestine. The results of the present study revealed novel insights into regional differences in nerve-mediated secretion in the human intestine and comprise the basis by which to more specifically target impaired epithelial functions in the diseased gut. ABSTRACT Knowledge on basic features of epithelial functions in the human intestine is scarce. We used Ussing chamber techniques to record basal tissue resistance (R-basal) and short circuit currents (ISC; secretion) under basal conditions (ISC-basal) and after electrical field stimulation (ISC-EFS) of nerves in 2221 resectates from 435 patients. ISC-EFS was TTX-sensitive and of comparable magnitude in the small and large intestine. ISC-EFS or R-basal were not influenced by the patients' age, sex or disease pathologies (cancer, polyps, diverticulitis). Ion substitution, bumetanide or adenylate cyclase inhibition studies suggested that ISC-EFS depended on epithelial cAMP-driven chloride and bicarbonate secretion but not on amiloride-sensitive sodium absorption. Although atropine-sensitive cholinergic components prevailed for ISC-EFS of the duodenum, jejunum and ileum, PG97-269-sensitive [vasoactive intestinal peptide (VIP) receptor 1 antagonist] VIPergic together with L-NAME-sensitive nitrergic components dominated the ISC-EFS in colonic preparations. Differences in numbers of cholinergic or VIPergic neurons, sensitivity of epithelial muscarinic or VIP receptors, or stimulus frequency-dependent transmitter release were not responsible for the region-specific transmitter contribution to ISC-EFS. Instead, the low atropine-sensitivity of ISC-EFS in the colon was the result of high cholinesterase activity because neostigmine revealed cholinergic components. Colonic ISC-EFS remained unchanged after tachykinin, P2X, P2Y or A1 and A2 receptor blockade. R-basal was smaller and ISC-basal was higher in the small intestine. TTX and bumetanide decreased ISC-basal in all regions, suggesting nerve-dependent secretory tone. ISC-basal was atropine-sensitive in the small intestine and PG97-269-sensitive in the large intestine. This comprehensive study reveals novel insights into region-specific nerve-mediated secretion in the human small and large intestine.
Collapse
Affiliation(s)
- Dagmar Krueger
- Human Biology, Technische Universität München, Freising, Germany
| | - Klaus Michel
- Human Biology, Technische Universität München, Freising, Germany
| | | | - Ihsan E Demir
- Department of General Surgery, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Güralp O Ceyhan
- Department of General Surgery, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Julia Slotta-Huspenina
- Institute of Pathology, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Michael Schemann
- Human Biology, Technische Universität München, Freising, Germany
| |
Collapse
|
22
|
Kugler EM, Michel K, Zeller F, Demir IE, Ceyhan GO, Schemann M, Mazzuoli-Weber G. Mechanical stress activates neurites and somata of myenteric neurons. Front Cell Neurosci 2015; 9:342. [PMID: 26441520 PMCID: PMC4569744 DOI: 10.3389/fncel.2015.00342] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 08/18/2015] [Indexed: 12/24/2022] Open
Abstract
The particular location of myenteric neurons, sandwiched between the 2 muscle layers of the gut, implies that their somata and neurites undergo mechanical stress during gastrointestinal motility. Existence of mechanosensitive enteric neurons (MEN) is undoubted but many of their basic features remain to be studied. In this study, we used ultra-fast neuroimaging to record activity of primary cultured myenteric neurons of guinea pig and human intestine after von Frey hair evoked deformation of neurites and somata. Independent component analysis was applied to reconstruct neuronal morphology and follow neuronal signals. Of the cultured neurons 45% (114 out of 256, 30 guinea pigs) responded to neurite probing with a burst spike frequency of 13.4 Hz. Action potentials generated at the stimulation site invaded the soma and other neurites. Mechanosensitive sites were expressed across large areas of neurites. Many mechanosensitive neurites appeared to have afferent and efferent functions as those that responded to deformation also conducted spikes coming from the soma. Mechanosensitive neurites were also activated by nicotine application. This supported the concept of multifunctional MEN. 14% of the neurons (13 out of 96, 18 guinea pigs) responded to soma deformation with burst spike discharge of 17.9 Hz. Firing of MEN adapted rapidly (RAMEN), slowly (SAMEN), or ultra-slowly (USAMEN). The majority of MEN showed SAMEN behavior although significantly more RAMEN occurred after neurite probing. Cultured myenteric neurons from human intestine had similar properties. Compared to MEN, dorsal root ganglion neurons were activated by neurite but not by soma deformation with slow adaptation of firing. We demonstrated that MEN exhibit specific features very likely reflecting adaptation to their specialized functions in the gut.
Collapse
Affiliation(s)
- Eva M Kugler
- Human Biology, Technische Universitaet Muenchen Freising, Germany
| | - Klaus Michel
- Human Biology, Technische Universitaet Muenchen Freising, Germany
| | - Florian Zeller
- Department of Surgery, Klinikum Freising Freising, Germany
| | - Ihsan E Demir
- Department of Surgery, Klinikum Rechts der Isar, Technische Universitaet Muenchen Munich, Germany
| | - Güralp O Ceyhan
- Department of Surgery, Klinikum Rechts der Isar, Technische Universitaet Muenchen Munich, Germany
| | - Michael Schemann
- Human Biology, Technische Universitaet Muenchen Freising, Germany
| | | |
Collapse
|
23
|
Piepgras J, Höltje M, Michel K, Li Q, Otto C, Drenckhahn C, Probst C, Schemann M, Jarius S, Stöcker W, Balint B, Meinck HM, Buchert R, Dalmau J, Ahnert-Hilger G, Ruprecht K. Anti-DPPX encephalitis: pathogenic effects of antibodies on gut and brain neurons. Neurology 2015; 85:890-7. [PMID: 26291285 DOI: 10.1212/wnl.0000000000001907] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 05/07/2015] [Indexed: 01/01/2023] Open
Abstract
OBJECTIVE To characterize pathogenic effects of antibodies to dipeptidyl-peptidase-like protein 6 (DPPX), a subunit of Kv4.2 potassium channels, on gut and brain neurons. METHODS We identified a new patient with anti-DPPX encephalitis and analyzed the effects of the patient's serum and purified immunoglobulin G (IgG), and of serum of a previous patient with anti-DPPX encephalitis, on the activity of enteric neurons by voltage-sensitive dye imaging in guinea pig myenteric and human submucous plexus preparations. We studied the subcellular localization of DPPX by immunocytochemistry in cultured murine hippocampal neurons using sera of 4 patients with anti-DPPX encephalitis. We investigated the influence of anti-DPPX-containing serum and purified IgG on neuronal surface expression of DPPX and Kv4.2 by immunoblots of purified murine hippocampal neuron membranes. RESULTS The new patient with anti-DPPX encephalitis presented with a 2-month episode of diarrhea, which was followed by tremor, disorientation, and mild memory impairment. Anti-DPPX-IgG-containing sera and purified IgG increased the excitability and action potential frequency of guinea pig and human enteric nervous system neurons. Patient sera revealed a somatodendritic and perisynaptic neuronal surface staining that colocalized with the signal of commercial anti-DPPX and Kv4.2 antibodies. Incubation of hippocampal neurons with patient serum and purified IgG resulted in a decreased expression of DPPX and Kv4.2 in neuronal membranes. CONCLUSIONS Hyperexcitability of enteric nervous system neurons and downregulation of DPPX and Kv4.2 from hippocampal neuron membranes mirror the clinical phenotype of patients with anti-DPPX encephalitis and support a pathogenic role of anti-DPPX antibodies in anti-DPPX encephalitis.
Collapse
Affiliation(s)
- Johannes Piepgras
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Markus Höltje
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Klaus Michel
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Qin Li
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Carolin Otto
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Christoph Drenckhahn
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Christian Probst
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Michael Schemann
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Sven Jarius
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Winfried Stöcker
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Bettina Balint
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Hans-Michael Meinck
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Ralph Buchert
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Josep Dalmau
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Gudrun Ahnert-Hilger
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain
| | - Klemens Ruprecht
- From the Department of Neurology (J.P., K.R.), Institute for Integrative Neuroanatomy (J.P., M.H., C.D., G.A.-H.), and Department of Nuclear Medicine (R.B.), Charité-Universitätsmedizin Berlin; the Department of Human Biology (K.M., Q.L., M.S.), Technische Universität München, Munich, Germany; the Department of Physiology (Q.L.), Shangdong University School of Medicine, China; St. Josefs-Krankenhaus Potsdam (C.O.); the Institute for Experimental Immunology (C.P., W.S.), affiliated to Euroimmun AG, Lübeck; Molecular Neuroimmunology and Department of Neurology (S.J., B.B., H.-M.M.), University of Heidelberg, Germany; and the Catalan Institution of Research and Advanced Studies (ICREA) and Biomedical Research Institute August Pi i Sunyer (IDIBAPS) (J.D.), Hospital Clinic, University of Barcelona, Spain.
| |
Collapse
|
24
|
Brugmann W, Laureano A, Michel K, Tao RH, Kennis B, Somanchi S, Denman C, Ho KC, Silla L, Singh H, Huls H, Sandberg D, Lee D, Bankson J, Huang A, Cooper L, Gopalakrishnan V. IM-07 * NK CELL IMMUNOTHERAPY FOR PEDIATRIC BRAIN TUMORS: OVERCOMING RESISTANCE TO EXPAND THERAPEUTIC SUCCESS. Neuro Oncol 2015. [DOI: 10.1093/neuonc/nov061.62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
25
|
Liñán-Rico A, Wunderlich JE, Enneking JT, Tso DR, Grants I, Williams KC, Otey A, Michel K, Schemann M, Needleman B, Harzman A, Christofi FL. Neuropharmacology of purinergic receptors in human submucous plexus: Involvement of P2X₁, P2X₂, P2X₃ channels, P2Y and A₃ metabotropic receptors in neurotransmission. Neuropharmacology 2015; 95:83-99. [PMID: 25724083 DOI: 10.1016/j.neuropharm.2015.02.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 02/11/2015] [Accepted: 02/15/2015] [Indexed: 02/08/2023]
Abstract
RATIONALE The role of purinergic signaling in human ENS is not well understood. We sought to further characterize the neuropharmacology of purinergic receptors in human ENS and test the hypothesis that endogenous purines are critical regulators of neurotransmission. EXPERIMENTAL APPROACH LSCM-Fluo-4/(Ca(2+))-imaging of postsynaptic Ca(2+) transients (PSCaTs) was used as a reporter of synaptic transmission evoked by fiber tract electrical stimulation in human SMP surgical preparations. Pharmacological analysis of purinergic signaling was done in 1,556 neurons (identified by HuC/D-immunoreactivity) in 235 ganglia from 107 patients; P2XR-immunoreactivity was evaluated in 19 patients. Real-time MSORT (Di-8-ANEPPS) imaging tested effects of adenosine on fast excitatory synaptic potentials (fEPSPs). RESULTS Synaptic transmission is sensitive to pharmacological manipulations that alter accumulation of extracellular purines: Apyrase blocks PSCaTs in a majority of neurons. An ecto-NTPDase-inhibitor 6-N,N-diethyl-D-β,γ-dibromomethyleneATP or adenosine deaminase augments PSCaTs. Blockade of reuptake/deamination of eADO inhibits PSCaTs. Adenosine inhibits fEPSPs and PSCaTs (IC50 = 25 µM), sensitive to MRS1220-antagonism (A3AR). A P2Y agonist ADPβS inhibits PSCaTs (IC50 = 111 nM) in neurons without stimulatory ADPbS responses (EC50 = 960 nM). ATP or a P2X1,2,2/3 (α,β-MeATP) agonist evokes fast, slow, biphasic Ca(2+) transients or Ca(2+) oscillations (ATP,EC50 = 400 mM). PSCaTs are sensitive to P2X1 antagonist NF279. Low (20 nM) or high (5 µM) concentrations of P2X antagonist TNP-ATP block PSCaTs in different neurons; proportions of neurons with P2XR-immunoreactivity follow the order P2X2 > P2X1 >> P2X3; P2X1 + P2X2 and P2X3 + P2X2 are co-localized. RT-PCR identified mRNA-transcripts for P2X1-7, P2Y1,2,12-14R. CONCLUSIONS Purines are critical regulators of neurotransmission in human ENS. Purinergic signaling involves P2X1, P2X2, P2X3 channels, P2X1 + P2X2 co-localization and inhibitory P2Y or A3 receptors. These are potential novel therapeutic targets for neurogastroenterology.
Collapse
Affiliation(s)
- A Liñán-Rico
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - J E Wunderlich
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - J T Enneking
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - D R Tso
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - I Grants
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - K C Williams
- Division of Pediatric Gastroenterology, The Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - A Otey
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - K Michel
- Human Biology, Technische Universität München, Freising, Germany
| | - M Schemann
- Human Biology, Technische Universität München, Freising, Germany
| | - B Needleman
- Department of Surgery, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - A Harzman
- Department of Surgery, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA
| | - F L Christofi
- Department of Anesthesiology, The Wexner Medical Center at The Ohio State University, Columbus, OH, USA.
| |
Collapse
|
26
|
Abstract
Biting midges in the genus Culicoides are important vectors of arboviral diseases, including epizootic haemorrhagic disease, bluetongue and most likely Schmallenberg, which cause significant economic burdens worldwide. Research on these vectors has been hindered by the lack of a sequenced genome, the difficulty of consistent culturing of certain species and the absence of molecular techniques such as RNA interference (RNAi). Here, we report the establishment of RNAi as a research tool for the adult midge, Culicoides sonorensis. Based on previous research and transcriptome analysis, which revealed putative small interfering RNA pathway member orthologues, we hypothesized that adult C. sonorensis midges have the molecular machinery needed to perform RNA silencing. Injection of control double-stranded RNA targeting green fluorescent protein (dsGFP), into the haemocoel of 2-3-day-old adult female midges resulted in survival curves that support virus transmission. dsRNA injection targeting the newly identified C. sonorensis inhibitor of apoptosis protein 1 (CsIAP1) orthologue resulted in a 40% decrease of transcript levels and 73% shorter median survivals as compared with dsGFP-injected controls. These results reveal the conserved function of IAP1. Importantly, they also demonstrate the feasibility of RNAi by dsRNA injection in adult midges, which will greatly facilitate studies of the underlying mechanisms of vector competence in C. sonorensis.
Collapse
Affiliation(s)
- Mary K. Mills
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - D. Nayduch
- USDA-ARS, Center for Grain and Animal Health Research, Arthropod Borne Animal Diseases Research Unit, Manhattan, KS 66502, USA
| | - K. Michel
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
- Corresponding author: Kristin Michel,
| |
Collapse
|
27
|
Ostertag D, Buhner S, Michel K, Pehl C, Kurjak M, Götzberger M, Schulte-Frohlinde E, Frieling T, Enck P, Phillip J, Schemann M. Reduced Responses of Submucous Neurons from Irritable Bowel Syndrome Patients to a Cocktail Containing Histamine, Serotonin, TNFα, and Tryptase (IBS-Cocktail). Front Neurosci 2015; 9:465. [PMID: 26733780 PMCID: PMC4679876 DOI: 10.3389/fnins.2015.00465] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 11/23/2015] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND AND AIMS Malfunctions of enteric neurons are believed to play an important role in the pathophysiology of irritable bowel syndrome (IBS). Our aim was to investigate whether neuronal activity in biopsies from IBS patients is altered in comparison to healthy controls (HC). METHODS Activity of human submucous neurons in response to electrical nerve stimulation and local application of nicotine or a mixture of histamine, serotonin, tryptase, and TNF-α (IBS-cocktail) was recorded in biopsies from 17 HC and 35 IBS patients with the calcium-sensitive-dye Fluo-4 AM. The concentrations of the mediators resembeled those found in biopsy supernatants or blood. Neuronal activity in guinea-pig submucous neurons was studied with the voltage-sensitive-dye di-8-ANEPPS. RESULTS Activity in submucous ganglia in response to nicotine or electrical nerve stimulation was not different between HC and IBS patients (P = 0.097 or P = 0.448). However, the neuronal response after application of the IBS-cocktail was significantly decreased (P = 0.039) independent of whether diarrhea (n = 12), constipation (n = 5) or bloating (n = 5) was the predominant symptom. In agreement with this we found that responses of submucous ganglia conditioned by overnight incubation with IBS mucosal biopsy supernatant to spritz application of this supernatant was significantly reduced (P = 0.019) when compared to incubation with HC supernatant. CONCLUSION We demonstrated for the first time reduced neuronal responses in mucosal IBS biopsies to an IBS mediator cocktail. While excitability to classical stimuli of enteric neurons was comparable to HC, the activation by the IBS-cocktail was decreased. This was very likely due to desensitization to mediators constantly released by mucosal and immune cells in the gut wall of IBS patients.
Collapse
Affiliation(s)
| | - Sabine Buhner
- Human Biology, Technische Universität MünchenFreising, Germany
| | - Klaus Michel
- Human Biology, Technische Universität MünchenFreising, Germany
| | | | | | | | | | | | - Paul Enck
- Academic Hospital TübingenTübingen, Germany
| | | | - Michael Schemann
- Human Biology, Technische Universität MünchenFreising, Germany
- *Correspondence: Michael Schemann
| |
Collapse
|
28
|
Matteoli G, Gomez-Pinilla PJ, Nemethova A, Di Giovangiulio M, Cailotto C, van Bree SH, Michel K, Tracey KJ, Schemann M, Boesmans W, Vanden Berghe P, Boeckxstaens GE. A distinct vagal anti-inflammatory pathway modulates intestinal muscularis resident macrophages independent of the spleen. Gut 2014; 63:938-48. [PMID: 23929694 DOI: 10.1136/gutjnl-2013-304676] [Citation(s) in RCA: 297] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The cholinergic anti-inflammatory pathway (CAIP) has been proposed as a key mechanism by which the brain, through the vagus nerve, modulates the immune system in the spleen. Vagus nerve stimulation (VNS) reduces intestinal inflammation and improves postoperative ileus. We investigated the neural pathway involved and the cells mediating the anti-inflammatory effect of VNS in the gut. The effect of VNS on intestinal inflammation and transit was investigated in wild-type, splenic denervated and Rag-1 knockout mice. To define the possible role of α7 nicotinic acetylcholine receptor (α7nAChR), we used knockout and bone marrow chimaera mice. Anterograde tracing of vagal efferents, cell sorting and Ca(2+) imaging were used to reveal the intestinal cells targeted by the vagus nerve. VNS attenuates surgery-induced intestinal inflammation and improves postoperative intestinal transit in wild-type, splenic denervated and T-cell-deficient mice. In contrast, VNS is ineffective in α7nAChR knockout mice and α7nAChR-deficient bone marrow chimaera mice. Anterograde labelling fails to detect vagal efferents contacting resident macrophages, but shows close contacts between cholinergic myenteric neurons and resident macrophages expressing α7nAChR. Finally, α7nAChR activation modulates ATP-induced Ca(2+) response in small intestine resident macrophages. We show that the anti-inflammatory effect of the VNS in the intestine is independent of the spleen and T cells. Instead, the vagus nerve interacts with cholinergic myenteric neurons in close contact with the muscularis macrophages. Our data suggest that intestinal muscularis resident macrophages expressing α7nAChR are most likely the ultimate target of the gastrointestinal CAIP.
Collapse
Affiliation(s)
- Gianluca Matteoli
- Department of Clinical and Experimental Medicine, Translational Research Center for Gastrointestinal Disorders (TARGID), University of Leuven, , Leuven, Belgium
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Michel K, Zarogiannis SG. Clinical tests for intestinal permeability: ‘Sweet’ transition from clinical to basic physiology. Clin Exp Pharmacol Physiol 2014; 41:105-6. [DOI: 10.1111/1440-1681.12192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Klaus Michel
- Department of Human Biology; Technische Universität München; Freising Germany
| | - Sotirios G Zarogiannis
- Department of Physiology; University of Thessaly Medical School; Biopolis; Larissa Greece
| |
Collapse
|
30
|
Bilkei-Gorzo A, Mauer D, Michel K, Zimmer A. Dynorphins regulate the strength of social memory. Neuropharmacology 2014; 77:406-13. [DOI: 10.1016/j.neuropharm.2013.10.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 09/30/2013] [Accepted: 10/15/2013] [Indexed: 11/16/2022]
|
31
|
Jones D, Beaubien S, Barlow T, Barkwith A, Hannis S, Lister T, Strutt M, Bellomo T, Annunziatellis A, Graziani S, Lombardi S, Ruggiero L, Braibant G, Gal F, Joublin F, Michel K. Baseline variability in onshore near surface gases and implications for monitoring at CO2 storage sites. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.egypro.2014.11.447] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
32
|
Maubec N, Lerouge C, Lahfid A, Wille G, Michel K, Bourrat X. Coupled SEM-microRaman system: A powerful tool to characterize a micrometric aluminum-phosphate–sulfate (APS). J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2013.05.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
33
|
Mittal S, Shaw RE, Michel K, Palekar R, Arshad A, Musat D, Preminger M, Sichrovsky T, Steinberg JS. The impact of the AIGISRX antimicrobial pouch on Cardiac Implantable Electronic Device (CIED) infection rates: a comparison of de novo vs non-de novo procedures. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht308.p1381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
34
|
Mittal S, Shaw RE, Michel K, Palekar R, Arshad A, Musat D, Preminger M, Sichrovsky T, Steinberg JSS. Cardiac Implantable Electronic Device (CIED) infections: incidence, risk factors, and implications for hospital surveillance programs. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht308.p1402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
35
|
Krueger D, Michel K, Allam S, Weiser T, Demir IE, Ceyhan GO, Zeller F, Schemann M. Effect of hyoscine butylbromide (Buscopan®) on cholinergic pathways in the human intestine. Neurogastroenterol Motil 2013; 25:e530-9. [PMID: 23682729 DOI: 10.1111/nmo.12156] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 04/23/2013] [Indexed: 12/12/2022]
Abstract
BACKGROUND Hyoscine butylbromide (HBB, Buscopan(®) ) is clinically used to treat intestinal cramps and visceral pain. Various studies, mainly on animal tissues, suggested that its antimuscarinic action is responsible for its spasmolytic effect. However, functional in vitro studies with human tissue have not been performed so far. METHODS We wanted to provide a comprehensive study on the mode of action of HBB in human intestinal samples and investigated HBB (1 nmol L(-1) -10 μmol L(-1)) effects on muscle activity with isometric force transducers and calcium imaging, on epithelial secretion with Ussing chamber technique and on enteric neurons using fast neuroimaging. KEY RESULTS Hyoscine butylbromide concentration dependently reduced muscle contractions, calcium mobilization, and epithelial secretion induced by the muscarinic agonist bethanechol with IC50 values of 429, 121, and 224 nmol L(-1), respectively. Forskolin-induced secretion was not altered by HBB. Cholinergic muscarinic muscle and epithelial responses evoked by electrical nerve stimulation were inhibited by 1-10 μmol L(-1) HBB. Moreover, HBB significantly reduced the bethanechol-induced action potential discharge in enteric neurons. Interestingly, we observed that high concentrations of HBB (10 μmol L(-1)) moderately decreased nicotinic receptor-mediated secretion, motility, and nerve activity. CONCLUSIONS & INFERENCES The results demonstrated the strong antimuscarinic action of HBB whereas the nicotinic antagonism at higher concentrations plays at most a moderate modulatory role. The muscle relaxing effect of HBB and its inhibition of muscarinic nerve activation likely explain its clinical use as an antispasmodic drug. Our results further highlight a so far unknown antisecretory action of HBB which warrants further clinical studies on its use in secretory disorders.
Collapse
Affiliation(s)
- D Krueger
- Human Biology, Technische Universität München, Freising, Germany
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Kugler E, Michel K, Kirchenbüchler D, Dreissen G, Merkel R, Schemann M, Mazzuoli G. Physiological mechanical stimulation activates isolated myenteric neurons. Auton Neurosci 2013. [DOI: 10.1016/j.autneu.2013.05.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
37
|
Rubinstein A, Yang J, Martin R, Kingsley C, Delacerda J, Michel K, Zhang L, Tailor R, Pan T, Yang P, Hazle J, Court L. SU-D-144-03: Respiratory Motion Management for High-Precision Small Animal Irradiation. Med Phys 2013. [DOI: 10.1118/1.4814063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
38
|
Zhang L, Michel K, Yang J, Rubinstein A, Kingsley C, Delacerda J, Balter P, Court L. SU-E-J-34: A Multi-Modality Image Atlas for Transforming An MR Image Into a Pseudo CT Image for MRI-Based IGRT Application. Med Phys 2013. [DOI: 10.1118/1.4814246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
|
39
|
Maubec N, Lahfid A, Lerouge C, Wille G, Michel K. Characterization of alunite supergroup minerals by Raman spectroscopy. Spectrochim Acta A Mol Biomol Spectrosc 2012; 96:925-939. [PMID: 22954806 DOI: 10.1016/j.saa.2012.07.094] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 06/25/2012] [Accepted: 07/05/2012] [Indexed: 06/01/2023]
Abstract
Raman spectroscopy has been used to study the molecular structure of different natural minerals of the alunite supergroup (AB(3)(XO(4))(2)(OH)(6)), with A=K(+), Na(+), Ca(2+), Sr(2+), Ba(2+), B=Al(3+), Fe(3+) and X=S(6+), P(5+). The influence of the ions, in A-, B- and X-sites, is highlighted in the Raman spectra by variations in the position of certain vibrations and is discussed in association with published crystallographic data in order to describe the observed differences. It was found that A-site substitutions are characterized by wavenumber shifts of the vibrations involving hydroxyl groups. The positions of these vibrational bands vary linearly with the ionic radius of the ions in this site. B-site substitutions induce shifts of all bands due to structural modifications that lead to differences in the chemical environment around the hydroxyl and XO(4) groups and changes in B-O bond lengths. A correlation showed that these shifts correlate well with the ionic radii of the B-ions. The spectra of compounds containing both sulfate and phosphate groups are described by numerous vibration bands caused by a complex elemental composition and a symmetry change of the XO(4) groups. This study has also made it possible to generalize substitution effects on the wavenumbers of several vibrations and show that Raman spectroscopy could be a powerful tool for identifying and distinguishing minerals of the alunite supergroup.
Collapse
Affiliation(s)
- N Maubec
- BRGM, 3 Avenue Claude Guillemin, BP 36009, 45060 Orléans Cédex 2, France.
| | | | | | | | | |
Collapse
|
40
|
Bursztein Lipsicas C, Makinen IH, Wasserman D, Apter A, Kerkhof A, Michel K, Salander Renberg E, van Heeringen K, Varnik A, Schmidtke A. Gender distribution of suicide attempts among immigrant groups in European countries--an international perspective. Eur J Public Health 2012; 23:279-84. [DOI: 10.1093/eurpub/cks029] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
41
|
Mueller K, Michel K, Krueger D, Demir IE, Ceyhan GO, Zeller F, Kreis ME, Schemann M. Activity of protease-activated receptors in the human submucous plexus. Gastroenterology 2011; 141:2088-2097.e1. [PMID: 21875497 DOI: 10.1053/j.gastro.2011.08.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 07/25/2011] [Accepted: 08/19/2011] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Protease-activated receptors (PARs) are expressed in the enteric nervous system. Excessive release of proteases has been reported in functional and inflammatory bowel diseases. Studies in several animal models indicate the involvement of neural PARs. We studied the actions of different PAR-activating peptides (AP) in the human submucous plexus and performed comparative studies in guinea pig submucous neurons. METHODS We used voltage- and calcium-sensitive dye recordings to study the effects of PAR1-AP, PAR2-AP, PAR4-AP, the PAR1 activator thrombin, and the PAR2 activator tryptase on neurons and glia in human and guinea pig submucous plexus. Human preparations were derived from surgical resections. Levels of mucosal secretion evoked by PAR-APs were measured in Ussing chambers. RESULTS PAR1-AP and thrombin evoked a prominent spike discharge and intracellular Ca(2+) concentration ([Ca](i)) transients in most human submucous neurons and glia. PAR2-AP, tryptase, and PAR4-AP caused significantly weaker responses in a minor population. In contrast, PAR2-AP evoked much stronger responses in enteric neurons and glia of guinea pigs than did PAR1-AP or PAR4-AP. PAR1-AP, but not PAR2-AP or PAR4-AP, evoked a nerve-mediated secretion in human epithelium. The PAR1 antagonist SCH79797 inhibited the PAR1-AP, and thrombin evoked responses on neurons, glia, and epithelial secretion. In the submucous layer of human intestine, but not guinea pig intestine, PAR2-AP evoked [Ca](i) signals in CD68(+) macrophages. CONCLUSIONS In the human submucous plexus, PAR1, rather than PAR2 or PAR4, activates nerves and glia. These findings indicate that PAR1 should be the focus of future studies on neural PAR-mediated actions in the human intestine; PAR1 might be developed as a therapeutic target for gastrointestinal disorders associated with increased levels of proteases.
Collapse
Affiliation(s)
- Kerstin Mueller
- Human Biology, Technische Universität München, Freising, Germany
| | | | | | | | | | | | | | | |
Collapse
|
42
|
Michel K, Michaelis M, Mazzuoli G, Mueller K, Vanden Berghe P, Schemann M. Fast calcium and voltage-sensitive dye imaging in enteric neurones reveal calcium peaks associated with single action potential discharge. J Physiol 2011; 589:5941-7. [PMID: 22041184 DOI: 10.1113/jphysiol.2011.219550] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Slow changes in [Ca(2+)](i) reflect increased neuronal activity. Our study demonstrates that single-trial fast [Ca(2+)](i) imaging (≥200 Hz sampling rate) revealed peaks each of which are associated with single spike discharge recorded by consecutive voltage-sensitive dye (VSD) imaging in enteric neurones and nerve fibres. Fast [Ca(2+)](i) imaging also revealed subthreshold fast excitatory postsynaptic potentials. Nicotine-evoked [Ca(2+)](i) peaks were reduced by -conotoxin and blocked by ruthenium red or tetrodotoxin. Fast [Ca(2+)](i) imaging can be used to directly record single action potentials in enteric neurones. [Ca(2+)](i) peaks required opening of voltage-gated sodium and calcium channels as well as Ca(2+) release from intracellular stores.
Collapse
Affiliation(s)
- K Michel
- Human Biology, Technische Universität München, Freising, Germany
| | | | | | | | | | | |
Collapse
|
43
|
Vignali S, Peter N, Ceyhan G, Demir IE, Zeller F, Senseman D, Michel K, Schemann M. Recordings from human myenteric neurons using voltage-sensitive dyes. J Neurosci Methods 2010; 192:240-8. [PMID: 20691728 DOI: 10.1016/j.jneumeth.2010.07.038] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Revised: 07/02/2010] [Accepted: 07/29/2010] [Indexed: 11/15/2022]
Abstract
Voltage-sensitive dye (VSD) imaging became a powerful tool to detect neural activity in the enteric nervous system, including its routine use in submucous neurons in freshly dissected human tissue. However, VSD imaging of human myenteric neurons remained a challenge because of limited visibility of the ganglia and dye accessibility. We describe a protocol to apply VSD for recordings of human myenteric neurons in freshly dissected tissue and myenteric neurons in primary cultures. VSD imaging of guinea-pig myenteric neurons was used for reference. Electrical stimulation of interganglionic fiber tracts and exogenous application of nicotine or elevated KCl solution was used to evoke action potentials. Bath application of the VSDs Annine-6Plus, Di-4-ANEPPS, Di-8-ANEPPQ, Di-4-ANEPPDHQ or Di-8-ANEPPS revealed no neural signals in human tissue although most of these VSD worked in guinea-pig tissue. Unlike methylene blue and FM1-43, 4-Di-2-ASP did not influence spike discharge and was used in human tissue to visualize myenteric ganglia as a prerequisite for targeted intraganglionic VSD application. Of all VSDs, only intraganglionic injection of Di-8-ANEPPS by a volume controlled injector revealed neuronal signals in human tissue. Signal-to-noise ratio increased by addition of dipicrylamine to Di-8-ANEPPS (0.98±0.16 vs. 2.4±0.62). Establishing VSD imaging in primary cultures of human myenteric neurons led to a further improvement of signal-to-noise ratio. This allowed us to routinely record spike discharge after nicotine application. The described protocol enabled reliable VSD recordings from human myenteric neurons but may also be relevant for the use of other fluorescent dyes in human tissues.
Collapse
Affiliation(s)
- Sheila Vignali
- Human Biology, Technische Universität München, Liesel-Beckmann-Strasse 4, 85354 Freising-Weihenstephan, Germany
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Gnatta D, Keitel E, Heineck I, Cardoso B, Rodrigues A, Michel K, Garcia V. Use of Tacrolimus and the Development of Posttransplant Diabetes Mellitus: A Brazilian Single-Center, Observational Study. Transplant Proc 2010; 42:475-8. [DOI: 10.1016/j.transproceed.2010.02.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
45
|
Schemann M, Hafsi N, Michel K, Kober OI, Wollmann J, Li Q, Zeller F, Langer R, Lee K, Cellek S. The beta3-adrenoceptor agonist GW427353 (Solabegron) decreases excitability of human enteric neurons via release of somatostatin. Gastroenterology 2010; 138:266-74. [PMID: 19786030 DOI: 10.1053/j.gastro.2009.09.046] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2009] [Revised: 08/07/2009] [Accepted: 09/17/2009] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS beta3 Adrenoceptor (beta3-AR) is expressed on adipocytes and enteric neurons. GW427353 is a human selective beta3-AR agonist with visceral analgesic effects. Some of its effects may involve release of somatostatin (SST) and actions on enteric neurons. The aim of this study was to investigate the mode of action of GW427353 in human submucous neurons. METHODS Voltage sensitive dye imaging was used to record from human submucous neurons. SST release from human primary adipocytes was measured with enzyme-linked immunoabsorbent assay. Immunohistochemistry was used to detect adiponectin, beta3-AR, SST, SST2 receptors, tyrosine hydroxylase (TH), and protein gene product 9.5. RESULTS Confocal imaging showed cytoplasmic beta3-AR labeling in somata of submucous neurons and nerve varicosities. GW427353 had no direct postsynaptic actions but decreased fast synaptic input to submucous neurons. Tissue perfusion with GW427353 reduced nicotine-evoked neuronal spike frequency, an effect prevented by the beta3-AR antagonist SR-59230 and the SST2-receptor antagonist CYN154806 and mimicked by the SST2 receptor agonist octreotide. Adipocytes expressed adiponectin, beta3-AR, and SST. TH-positive fibers were in close proximity to adipocytes. Submucous neurons expressed SST2 receptors. Human primary adipocytes released SST in response to GW427353 in a concentration-dependent manner, an effect abolished by SR-59230. CONCLUSIONS Inhibitory action of GW427353 involves release of SST which stimulates inhibitory SST2 receptors on human submucous neurons. Adipocytes are a potential source for SST. beta3-AR activation may be a promising approach to reduce enteric neuron hyperexcitability. The action of GW427353 may be the neurophysiologic correlate of its beneficial effect in patients with irritable bowel syndrome.
Collapse
Affiliation(s)
- Michael Schemann
- Human Biology, Technische Universität München, Freising, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Krueger D, Gruber L, Buhner S, Zeller F, Langer R, Seidl S, Michel K, Schemann M. The multi-herbal drug STW 5 (Iberogast) has prosecretory action in the human intestine. Neurogastroenterol Motil 2009; 21:1203-e110. [PMID: 19210628 DOI: 10.1111/j.1365-2982.2008.01242.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
There is growing evidence that STW 5 (Iberogast), fixed combination of hydroethanolic herbal extracts), besides being effective in functional dyspepsia, also improves symptoms in irritable bowel syndrome (IBS). Clinical data indicate that modulation of mucosal secretion is a promising approach to treat intestinal disorders associated with IBS. We therefore explored the effect of STW 5 on secretion in the human intestine and the mechanisms by which it acts. The Ussing chamber technique was used to measure mucosal secretion in human intestinal mucosa/submucosa preparations and in human epithelial cell line T84. In addition, we recorded STW 5 effects on human enteric neurons with voltage sensitive dye imaging. In human tissue and T84 cells STW 5 induced a dose-dependent increase in ion secretion that was significantly reduced by the Na-K-Cl cotransporter blocker bumetanide, the adenylate cyclase inhibitor MDL-12 330, the non-specific and selective cystic fibrosis transmembrane conductance regulator (CFTR) inhibitors glibenclamide and CFTR(inh)-172, respectively, and the blocker of calcium dependent Cl(-) channels (ClCa) SITS (4-acetamido-4-isothiocyanatostilbene-2,2-disulphonic acid). It was unaffected by amiloride, a blocker of epithelial Na(+) channels. In human tissue, the nerve blocker tetrodotoxin significantly suppressed the STW 5 response. STW 5 evoked an increased spike discharge in 51% of human submucous neurons. Results suggest that STW 5 is a secretogogue in the human intestine by direct epithelial actions and through activation of enteric neurons. The prosecretory effect is due to increased epithelial Cl(-) fluxes via CFTR and Ca-dependent ClCa channels. STW 5 may be a novel option to treat secretory disorders associated with IBS and constipation.
Collapse
Affiliation(s)
- D Krueger
- Department of Human Biology, Technische Universität München, München, Germany
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Buhner S, Li Q, Vignali S, Barbara G, De Giorgio R, Stanghellini V, Cremon C, Zeller F, Langer R, Daniel H, Michel K, Schemann M. Activation of human enteric neurons by supernatants of colonic biopsy specimens from patients with irritable bowel syndrome. Gastroenterology 2009; 137:1425-34. [PMID: 19596012 DOI: 10.1053/j.gastro.2009.07.005] [Citation(s) in RCA: 262] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 06/08/2009] [Accepted: 07/07/2009] [Indexed: 12/11/2022]
Abstract
BACKGROUND & AIMS Pathological features in irritable bowel syndrome (IBS) include alterations in mucosal cell content and mediator release that might alter signaling to nearby submucosal neurons. METHODS Voltage sensitive dye imaging was used to record the effects of mediators, released from mucosal biopsies of IBS patients, on cell bodies of 1207 submucosal neurons from 76 human colonic tissue specimens. Supernatants, containing these mediators, were collected following incubation with colonic mucosal biopsies from 7 patients with diarrhea-predominant IBS (D-IBS), 4 with constipation-predominant IBS (C-IBS), and 4 healthy controls. Serotonin, histamine and tryptase concentrations in supernatants and lamina propria mast cell density were determined. RESULTS In contrast to controls, IBS supernatants significantly increased the rate of spike discharge in 58% of human submucosal neurons. Neurons that responded to IBS supernatant had a median spike frequency of 2.4 Hz compared to 0 Hz for control supernatants. Supernatants from C-IBS and D-IBS evoked similar spike discharge. The activation induced by IBS supernatants was inhibited by histamine receptor (H1-H3) antagonists, 5-HT3 receptor antagonist, and protease inhibition. Serotonin, histamine and tryptase levels in supernatants correlated with the spike discharge induced by the supernatants. Mast cells density as well as histamine and tryptase levels in supernatants were higher in IBS than in controls. CONCLUSIONS Mediators released from mucosal biopsies of IBS patients can activate human submucosal neurons. The activation required histamine, serotonin and proteases but was not associated with IBS subtype. Altered signaling between mucosa and the enteric nervous system might be involved in IBS pathogenesis.
Collapse
Affiliation(s)
- Sabine Buhner
- Human Biology, Technische Universität München, Freising, Germany
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Ozolins V, Akbarzadeh AR, Gunaydin H, Michel K, Wolverton C, Majzoub EH. First-principles computational discovery of materials for hydrogen storage. ACTA ACUST UNITED AC 2009. [DOI: 10.1088/1742-6596/180/1/012076] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
49
|
Bertrand R, Michel K, Schemann M, Bertrand P. P4.11 Exploring short term plasticity in the enteric nervous system: Voltage-sensitive dye recordings of guinea pig myenteric neurons. Auton Neurosci 2009. [DOI: 10.1016/j.autneu.2009.05.178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
50
|
Abstract
Repair of biopolymers is a critical issue, especially with aged restorations. Obtaining a chemical bond to the repair surface might solve this problem. We hypothesized that certain repair liquids are suitable to establish a strong bond to an artificially aged dimethacrylate-based biopolymer for temporary restorations. Specimens made of a self-curing temporary crown-and-bridge material were prepared and thermocycled for 7 days (5000x, 5-55 degrees C). Cylinders made of light-curing composites (n=10) were bonded onto the specimen surface, either after grinding or after the application of 4 different experimental repair liquids (Bis-GMA:TEGDMA mixture=bonding, methylmethacrylate=MMA, bonding & acetone, bonding & MMA). A shear bond strength test was performed 24 hrs after repair. The highest bond strength was obtained with the bonding & acetone liquid (20.1+/-2.2 MPa). The use of MMA significantly affected the bond strength (6.8+/-1.9 MPa). MMA is inadequate as a repair liquid on aged composite-based biopolymers.
Collapse
Affiliation(s)
- M Balkenhol
- Department of Prosthetic Dentistry, Justus-Liebig-University, Schlangenzahl 14, D-35392 Giessen, Germany.
| | | | | | | |
Collapse
|