Novel Mutants of the Human β1-Adrenergic Receptor Reveal Amino Acids Relevant for Receptor Activation

Activation of G protein-coupled receptors like the beta(1)-adrenergic receptor results in conformational changes that ultimately lead to signal propagation through a G protein to an effector like adenylyl cyclase. In this study we identified amino acids that seem to be critical for activation of the human beta(1)-adrenergic receptor. Activation patterns of mutant receptors were analyzed using two structurally different ligands for beta-adrenergic receptors that both are mixed agonist/antagonists. Broxaterol and terbutaline are agonists at beta(2)- and beta(3)-receptors; however, they act as antagonists at the beta(1)-subtype. We reasoned that this functional selectivity may be reflected by a corresponding sequence pattern in the receptor subtypes. Therefore, we exchanged single amino acids of the beta(1)-adrenergic receptor for residues that were identical in the beta(2)- and beta(3)-subtypes but different in the beta(1)-receptor. Pharmacological characterization of such receptor mutants revealed that binding of a panel of agonists and antagonists including broxaterol and terbutaline was unaltered. However, two of the mutants (I185V and D212N) were activated by broxaterol and terbutaline, which acted as antagonists at the wild-type receptor. Two additional mutants (V120L and K253R) could be activated by terbutaline alone, which is structurally more closely related to endogenous catecholamines like epinephrine than to broxaterol. A model of the human beta(1)-adrenergic receptor showed that the four gain-of-function mutations are outside of the putative ligand-binding domain substantiating the lack of an effect of the mutations on binding characteristics. These results support the notion that Val-120, Ile-185, Asp-212, and Lys-253 are critically involved in conformational changes occurring during receptor activation

disrupted relationship with memory performance and potential implications for delusions

Recent concepts have highlighted the role of the hippocampus and adjacent medial temporal lobe (MTL) in positive symptoms like delusions in schizophrenia. In healthy individuals, the MTL is critically involved in the detection and encoding of novel information. Here, we aimed to investigate whether dysfunctional novelty processing by the MTL might constitute a potential neural mechanism contributing to the pathophysiology of delusions, using functional magnetic resonance imaging (fMRI) in 16 unmedicated patients with paranoid schizophrenia and 20 age-matched healthy controls. All patients experienced positive symptoms at time of participation. Participants performed a visual target detection task with complex scene stimuli in which novel and familiar rare stimuli were presented randomly intermixed with a standard and a target picture. Presentation of novel relative to familiar images was associated with hippocampal activation in both patients and healthy controls, but only healthy controls showed a positive relationship between novelty- related hippocampal activation and recognition memory performance after 24 h. Patients, but not controls, showed a robust neural response in the orbitofrontal cortex (OFC) during presentation of novel stimuli. Functional connectivity analysis in the patients further revealed a novelty-related increase of functional connectivity of both the hippocampus and the OFC with the rostral anterior cingulate cortex (rACC) and the ventral striatum (VS). Notably, delusions correlated positively with the difference of the functional connectivity of the hippocampus vs. the OFC with the rACC. Taken together, our results suggest that alterations of fronto-limbic novelty processing may contribute to the pathophysiology of delusions in patients with acute psychosis

Eddy Study to Understand Physical-Chemical-Biological Coupling and the Biological Carbon Pump as a Function of Eddy Type off West Africa, Cruise No. M160, 23.11.2019 - 20.12.2019, Mindelo (Cabo Verde) - Mindelo (Cabo Verde)

Cruise M160 is part of concerted MOSES/REEBUS Eddy Study featuring three major research expeditions (M156, M160, MSM104). It aims to develop both a qualitative and quantitative understanding of the role of physical-chemical-biological coupling in eddies for the biological pump. The study is part of the MOSES “Ocean Eddies” event chain, which follows three major hypotheses to be addressed by the MOSES/REEBUS field campaigns: (1) Mesoscale and sub-mesoscale eddies play an important role in transferring energy along the energy cascade from the large-scale circulation to dissipation at the molecular level. (2) Mesoscale and sub-mesoscale eddies are important drivers in determining onset, magnitude and characteristics of biological productivity in the ocean and contribute significantly to global primary production and particle export and transfer to the deep ocean. (3) Mesoscale and sub-mesoscale eddies are important for shaping extreme biogeochemical environments (e.g., pH, oxygen) in the oceans, thus acting as a source/sink function for greenhouse gases. In contrast to the other two legs, MOSES Eddy Study II during M160 did not include any benthic work but focused entirely on the pelagic dynamics within eddies. It accomplished a multi-disciplinary, multi-parameter and multi-platform study of two discrete cyclonic eddies in an unprecedented complexity. The pre-cruise search for discrete eddies suitable for detailed study during M160 had already started a few months prior to the cruise. Remote sensing data products (sea surface height, sea surface temperature, ocean color/chlorophyll a) were used in combination with eddy detection algorithms and numerical modelling to identify and track eddies in the entire eddy field off West Africa. In addition, 2 gliders and 1 waveglider had been set out from Mindelo/Cabo Verde for pre-cruise mapping of the potential working area north of the Cabo Verdean archipelago. At the start of M160, a few suitable eddies – mostly of cyclonic type – had been identified, some of which were outside the safe operation range of the motorglider plane. As technical problems delayed the flight operations, the first eddy (center at 14.5°N/25°W) for detailed study was chosen to the southwest of the island of Fogo. It was decided to carry out a first hydrographic survey there followed by the deployment of a suite of instruments (gliders, waveglider, floats, drifter short-term mooring). Such instrumented, we left this first eddy and transited – via a strong anticyclonic feature southwest of the island of Santiago – to the region northeast of the island of Sal, i.e. in the working range of the glider plane. During the transit, a full suite of underway measurements as well as CTD/RO section along 22°W (16°-18.5°N) were carried in search for sub-surface expressions of anticyclonic eddy features. In the northeast, we had identified the second strong cyclonic eddy (center at 18°N/22.5°W) which was chosen for detailed study starting with a complete hydrographic survey (ADCP, CTD/RO, other routine station work). After completion of the mesoscale work program, we identified a strong frontal region at the southwestern rim of the cyclonic eddy, which was chosen for the first sub-mesoscale study with aerial observation component. There, the first dye release experiment was carried out which consisted of the dye release itself followed by an intense multi-platforms study of the vertical and horizontal spreading of the initial dye streak. This work was METEOR-Berichte, Cruise M160, Mindelo – Mindelo, 23.11.2019 4 – 20.12.2019 supported and partly guided by aerial observation of the research motorglider Stemme, which was still somewhat compromised by technical issues and meteorological conditions (high cloud cover, Saharan dust event). Nevertheless, this first dye release experiment was successful and showed rapid movement of the dynamic meandering front. After completion of work on this second eddy and execution of a focused sampling program at the Cape Verde Ocean Observation, RV METEOR returned to the first eddy for continuation of the work started there in the beginning of the cruise. This was accompanied by a relocation of the airbase of Stemme from the international airport of Sal to the domestic airport of Fogo. The further execution of the eddy study at this first eddy, which again included a complete hydrographic survey followed by a mesoscale eddy study with dye release, was therefore possible with aerial observations providing important guidance for work on RV METEOR. Overall, M160 accomplished an extremely intense and complex work program with 212 instrument deployments during station work, 137 h of observation with towed instruments and a wide range of underway measurements throughout the cruise. Up to about 30 individually tracked platforms (Seadrones, glider, wavegliders, drifters, floats) were in the water at the same time providing unprecedented and orchestrated observation capabilities in an eddy. All planned work components were achieved and all working groups acquired the expected numbers of instrument deployments and sampling opportunities

Wnt Pathway in Bone Repair and Regeneration – What Do We Know So Far

Wnt signaling plays a central regulatory role across a remarkably diverse range of functions during embryonic development, including those involved in the formation of bone and cartilage. Wnt signaling continues to play a critical role in adult osteogenic differentiation of mesenchymal stem cells. Disruptions in this highly-conserved and complex system leads to various pathological conditions, including impaired bone healing, autoimmune diseases and malignant degeneration. For reconstructive surgeons, critically sized skeletal defects represent a major challenge. These are frequently associated with significant morbidity in both the recipient and donor sites. The Wnt pathway is an attractive therapeutic target with the potential to directly modulate stem cells responsible for skeletal tissue regeneration and promote bone growth, suggesting that Wnt factors could be used to promote bone healing after trauma. This review summarizes our current understanding of the essential role of the Wnt pathway in bone regeneration and repair

Photochemically produced SO2 in the atmosphere of WASP-39b

Photochemistry is a fundamental process of planetary atmospheres that regulates the atmospheric composition and stability1. However, no unambiguous photochemical products have been detected in exoplanet atmospheres so far. Recent observations from the JWST Transiting Exoplanet Community Early Release Science Program2,3 found a spectral absorption feature at 4.05 μm arising from sulfur dioxide (SO2) in the atmosphere of WASP-39b. WASP-39b is a 1.27-Jupiter-radii, Saturn-mass (0.28 MJ) gas giant exoplanet orbiting a Sun-like star with an equilibrium temperature of around 1,100 K (ref. 4). The most plausible way of generating SO2 in such an atmosphere is through photochemical processes5,6. Here we show that the SO2 distribution computed by a suite of photochemical models robustly explains the 4.05-μm spectral feature identified by JWST transmission observations7 with NIRSpec PRISM (2.7σ)8 and G395H (4.5σ)9. SO2 is produced by successive oxidation of sulfur radicals freed when hydrogen sulfide (H2S) is destroyed. The sensitivity of the SO2 feature to the enrichment of the atmosphere by heavy elements (metallicity) suggests that it can be used as a tracer of atmospheric properties, with WASP-39b exhibiting an inferred metallicity of about 10× solar. We further point out that SO2 also shows observable features at ultraviolet and thermal infrared wavelengths not available from the existing observations

Photochemically-produced SO2_2 in the atmosphere of WASP-39b

Photochemistry is a fundamental process of planetary atmospheres that regulates the atmospheric composition and stability. However, no unambiguous photochemical products have been detected in exoplanet atmospheres to date. Recent observations from the JWST Transiting Exoplanet Early Release Science Program found a spectral absorption feature at 4.05 $\mu$m arising from SO$_2$ in the atmosphere of WASP-39b. WASP-39b is a 1.27-Jupiter-radii, Saturn-mass (0.28 M$_J$) gas giant exoplanet orbiting a Sun-like star with an equilibrium temperature of $\sim$1100 K. The most plausible way of generating SO$_2$ in such an atmosphere is through photochemical processes. Here we show that the SO$_2$ distribution computed by a suite of photochemical models robustly explains the 4.05 $\mu$m spectral feature identified by JWST transmission observations with NIRSpec PRISM (2.7$\sigma$) and G395H (4.5$\sigma$). SO$_2$ is produced by successive oxidation of sulphur radicals freed when hydrogen sulphide (H$_2$S) is destroyed. The sensitivity of the SO$_2$ feature to the enrichment of the atmosphere by heavy elements (metallicity) suggests that it can be used as a tracer of atmospheric properties, with WASP-39b exhibiting an inferred metallicity of $\sim$10$\times$ solar. We further point out that SO$_2$ also shows observable features at ultraviolet and thermal infrared wavelengths not available from the existing observations.Comment: 39 pages, 14 figures, accepted to be published in Natur

NOVEL MUTANTS OF THE HUMAN BETA1-ADRENERGIC RECEPTOR REVEAL AMINO ACIDS RELEVANT FOR RECEPTOR ACTIVATION

Eine durch Aktivierung eines G-Protein gekoppelten Rezeptors induzierte Konfirmationsänderung resultiert in einer Signaltransduktion durch das G-Protein zu einem Effektorenzym wie der Adenylylcyclase. In dieser Arbeit konnten Aminosäuren in dem zur G-Protein gekoppelten Rezeptorfamilie zugehörigen beta1-adrenergen Rezeptor identifiziert werden, welche für dessen Aktivierung von Bedeutung sind. Der Analyse von beta1-adrenergen Rezeptormutanten lag die Erkenntnis zu Grunde, dass therapeutisch genutzte Liganden wie Terbutalin, oder das experimentell eingesetzte Broxaterol Agonisten am beta2- und beta3-adrenergen Rezeptor, jedoch Antagonisten am beta1-adrenergen Rezeptor sind. Dieses Verhalten wurde zum Anlass genommen spezifische Aminosäuren zu identifizieren, welche eine bedeutende Funktion in der Aktivierung von beta -Rezeptorsubtypen haben könnten. Nach einem Aminosäurevergleich innerhalb der Familie der beta-adrenergen Rezeptoren konnten Aminosäurepositionen identifiziert werden, die identisch im beta2- bzw. beta3-Rezeptor sind und sich von denen des beta1- Rezeptors unterscheiden und damit das Aktivierungsprofil von Broxaterol und Terbutalin widerspiegeln. Mit zielgerichteten Punktmutationen wurden nun insbesondere im Bereich der Transmembranregionen solche Aminosäuren im beta1-adrenergen Rezeptor durch die entsprechende des beta2- (beta3-) Rezeptors ersetzt. Obwohl keine der getesteten Mutanten Unterschiede im pharmakologischen Bindungsprofil zeigten, konnten vier Mutanten gefunden werden, welche partiell oder vollständig durch Broxaterol oder Terbutalin aktiviert wurden. Die beiden Mutanten I185L sowie D212N konnten mit Broxaterol und Terbutalin aktiviert werden, zwei Liganden, die Antagonisten am beta1- Wildtyprezeptor sind. Außerdem konnten zwei weitere Mutanten, V120L und K253R, durch Terbutalin aktiviert werden. Betrachtet man die Struktur von Terbutalin, so ist dieser Ligand den endogenen Katecholaminen ähnlicher als Broxaterol. Ein Rezeptormodell zeigt, dass die vier relevanten Aminosäuren außerhalb der Ligandenbindungsregion liegen und somit eine direkte Interaktion mit dem Liganden unwahrscheinlich erscheint. Diese These wird durch das im Vergleich zum Wildtyp nicht veränderte Bindungsprofil der beta1-Rezeptormutanten unterstützt. Diese Ergebnisse legen nahe, dass die Aminosäuren V120, I185, D212 und K253 in der ligandeninduzierten Konfirmationsänderung des beta1-Rezeptors von Bedeutung sind.Activation of G protein-coupled receptors like the beta1-adrenergic receptor results in conformational changes which ultimately lead to signal propagation through a G protein to an effector like adenylyl cyclase. In this study we identify amino acids which seem to be critical for activation of the human beta1-adrenergic receptor. Activation patterns of mutant receptors were analyzed using two structurally different ligands for beta-adrenergic receptors which both are mixed agonist/antagonists. Broxaterol and terbutaline are agonists at beta2- and beta3-receptors, however, they act as antagonists at the beta1-subtype. We reasoned that this functional selectivity may be reflected by a corresponding sequence pattern in the receptor subtypes. Therefore, we exchanged single amino acids of the beta1-adrenergic receptor for residues that were identical in the beta2- and beta3- subtypes but different in the beta1-receptor. Pharmacological characterization of such receptor mutants revealed that binding of a panel of agonists and antagonists including broxaterol and terbutaline was unaltered. However, two of the mutants (I185V and D212N) were activated by broxaterol and terbutaline which acted as antagonists at the wilde-type receptor. Two additional mutants (V120L and K253R) could be activated by terbutaline alone which is structurally more closely related to endogenous catecholamines like epinephrine than to broxaterol. A model of the human beta1-adrenergic receptor showed that the four gain-of-function mutations are outside of the putative ligand-binding domain substantiating the lack of an effect of the mutations on binding characteristics. These results support the notion that V120, I185, D212 and K253 are critically involved in conformational changes occuring during receptor activation

Diabetes, hyperglykemi och sårinfektion : - en studie av riskfaktorer för att drabbas av postoperativ sårinfektion efter CABG-kirurgi

Bakgrund: Postoperativa sårinfektioner är en vanligt förekommande vårdrelaterad infektion, och orsakar stort lidande för patienten och stora kostnader för sjukvården. Diabetes är en riskfaktor för att utveckla postoperativ sårinfektion, och har liksom hyperglykemi fysiologiska effekter som bidrar till en ökad risk att utveckla postoperativ sårinfektion. Syftet med denna studie var att undersöka sambandet mellan diabetes, postoperativ hyperglykemi och postoperativ sårinfektion hos patienter som genomgått CABG-kirurgi. Metod: Studien designades som en kvantitativ retrospektiv studie med deskriptiv ansats. Data insamlades dels från vårdenhetens egen infektionsregistrering, dels genom granskning av 276 patientjournaler på den aktuella vårdenheten. Urvalet gjordes med ett systematiskt urval från en population med totalt 890 patienter under åren 2006 - 2008. Resultat: Den genomförda studien kunde inte påvisa några statistiskt säkerställda samband mellan riskfaktorerna diabetes, förhöjda värden av HbA1c, postoperativ hyperglykemi och postoperativ sårinfektion med hjälp av bivariat analys. Emellertid visar en multivariat logistisk regressionsanalys att det starkaste sambandet finns mellan ett förhöjt preoperativt värde för HbA1c och postoperativ sårinfektion. Slutsats: Den genomförda studien tyder på att det finns ett samband mellan preoperativt förhöjt HbA1c och postoperativ sårinfektion. Det behövs dock sannolikt mer forskning på området för att kunna säkerställa sambandet mellan diabetes, postoperativ hyperglykemi och postoperativ sårinfektion efter CABG-kirurgi. Background: Surgical wound infections are a common health care related infection, which causes great suffering for the patient, as well as great costs for the health care system. Diabetes mellitus is a risk factor for developing a surgical wound infection, and hyperglycemia has physiological effects that also contribute to this risk. Purpose: The purpose of this study was to examine the correlation between diabetes mellitus, post operative hyperglycemia and surgical wound infections in patients which had undergone CABG-surgery. Method: The study was designed as a retrospective quantitative study with a descriptive approach. Data was collected from the care unit’s own registration of patient-reported infections, as well as a review of the medical records of the 276 patients included in the sample. The sampling was done from a population of 890 patients who had undergone CABG-surgery in the years of 2006 through 2008. Results: This study could not find any correlation of statistical significance of the reviewed risk factors and the development of a surgical wound infection after CABG-surgery using a bivariate statistical analysis. However, a multiple logistic regression analysis showed that the strongest correlation was between elevated levels of preoperative HbA1c and surgical wound infection after CABG-surgery. Conclusion: More comprehensive research in the area is needed to fully understand the correlation between diabetes, postoperative hyperglycemia and surgical wound infections after CABG-surgery.

Det nya lönesystemet : Vägen till ett nytt lönesystem där icke monetära och monetära medel samspelar

När företagets ledning ska arbeta fram ”det nya lönesystemet” har vi kommit fram till att de anställda ska vara med och tycka till innan någon implementering sker. Vi anser att medarbetarna har en viktig roll vid framarbetandet av det nya lönesystemet då det ska verka för att motivera just medarbetarna. Vi säger vidare att under och efter implementeringsprocessens gång ska det finnas någon form av stöd och uppföljningssystem som är enkelt och lättåtkomligt för medarbetarna. Ett lyckat framtagande som resulterar i ett attraktivt lönesystem borde leda till att företaget vinner konkurrensfördelar under en längre framtid

Absence of endochondral ossification and craniosynostosis in posterior frontal cranial sutures of Axin2(-/-) mice.

During the first month of life, the murine posterior-frontal suture (PF) of the cranial vault closes through endochondral ossification, while other sutures remain patent. These processes are tightly regulated by canonical Wnt signaling. Low levels of active canonical Wnt signaling enable endochondral ossification and therefore PF-suture closure, whereas constitutive activation of canonical Wnt causes PF-suture patency. We therefore sought to test this concept with a knockout mouse model. PF-sutures of Axin2(-/-) mice, which resemble a state of constantly activated canonical Wnt signaling, were investigated during the physiological time course of PF-suture closure and compared in detail with wild type littermates. Histological analysis revealed that the architecture in Axin2(-/-) PF-sutures was significantly altered in comparison to wild type. The distance between the endocranial layers was dramatically increased and suture closure was significantly delayed. Moreover, physiological endochondral ossification did not occur, rather an ectopic cartilage appeared between the endocranial and ectocranial bone layers at P7 which eventually involutes at P13. Quantitative PCR analysis showed the lack of Col10α1 upregulation in Axin2(-/-) PF-suture. Immunohistochemistry and gene expression analysis also revealed high levels of type II collagen as compared to type I collagen and absence of Mmp-9 in the cartilage of Axin2(-/-) PF-suture. Moreover, TUNEL staining showed a high percentage of apoptotic chondrocytes in Axin2(-/-) PF-sutures at P9 and P11 as compared to wild type. These data indicated that Axin2(-/-) PF-sutures lack physiological endochondral ossification, contain ectopic cartilage and display delayed suture closure