TY  - JOUR
AB  - BACKGROUND AND PURPOSE: Lipolysis is tightly regulated by pro-lipolytic β-adrenoceptor signalling, which activates the cAMP/PKA pathway, and by antilipolytic hormones like insulin and FGF1, which counter-regulate lipolysis through cAMP-degrading phosphodiesterases (PDEs). While the spatial compartmentalization of cAMP signalling is recognized, comparisons between distinct cAMP pools remain under-investigated in adipocytes. Moreover, the dynamics of cAMP around lipid droplets (LD) where lipolysis occurs, are particularly intriguing. Thus, we studied whether adipose FGF1/PDE4D and insulin/PDE3B pathways regulate distinct cAMP microdomains to execute their antilipolytic actions. EXPERIMENTAL APPROACH: We evaluated the role of subcellular cAMP pools in lipolysis regulation by PDEs, or antilipolytic hormones, by utilizing EPAC1-based FRET cAMP biosensors specifically designed to localize in the cytoplasm or at the plasma membrane of living cells. Additionally, we developed the first LD-associated cAMP biosensor by fusing the lipid droplet-associated protein perilipin-1 to the EPAC1-based probe. KEY RESULTS: We identified previously unrecognized cAMP pools surrounding LDs that are distinct from cytoplasmic cAMP and resistant to PDE inhibition or antilipolytic stimuli. PDE4D exhibits a stronger effect on all three cAMP pools investigated than PDE3B. FGF1 mainly inhibits the cAMP in the initiation of the signalling at the plasma membrane, whereas insulin targets mainly cytoplasmic cAMP pools. CONCLUSION AND IMPLICATIONS: The discovery of LD-associated cAMP as a distinct subcellular pool suggests that cAMP signalling in adipocytes is more compartmentalized than previously recognized. The distinct pathways by which FGF1 and insulin regulate adipose cell cAMP levels highlight that antilipolytic signalling is not uniform, refining our understanding of lipolysis regulation.
AU  - Krier, J.
AU  - Spähn, D.*
AU  - Lopez, D.A.J.
AU  - Nono, J.L.
AU  - Seigner, J.
AU  - Ussar, S.
AU  - Lukowski, R.*
AU  - Birkenfeld, A.L.
AU  - Sancar, G.
C1  - 75778
C2  - 57987
CY  - 111 River St, Hoboken 07030-5774, Nj Usa
TI  - PDE4D and PDE3B orchestrate distinct cAMP microdomains in 3T3-L1 adipocytes.
JO  - Br. J. Pharmacol.
PB  - Wiley
PY  - 2025
SN  - 0007-1188
ER  - 

TY  - JOUR
AB  - BACKGROUND AND PURPOSE: Methanobactins are peptides with high copper affinity and potential to treat Wilson disease. We examined how two methanobactins (ARBM101 and MB-OB3b) affected copper handling in the LPP Atp7b-/- Wilson disease rat model, compared to penicillamine or saline, by 64Cu positron emission tomography/magnetic resonance imaging. Heterozygotes served as controls. EXPERIMENTAL APPROACH: 64Cu was administered i.v. to 19 LPP and four control rats. A baseline scan was performed 1 h later. LPP rats received one dose of saline, penicillamine, MB-OB3b or ARBM101 i.p. (t = 100 min), followed by a 90-min scan and a final scan at t = 24 h. Controls followed identical procedures without intervention. 64Cu levels were evaluated as % injected dose (%ID) in the liver, kidney and 'abdominal-pelvic region' (intestines and other non-hepatic, non-renal organs). KEY RESULTS: At baseline, hepatic %ID was ≈50% higher in LPP rats than in controls. Intraintestinal 64Cu activity, indicating biliary excretion, was present in controls and absent in LPP rats. After methanobactin injection (but not saline or penicillamine), 64Cu appeared in the small intestines of LPP rats within 10-15 min. Hepatic %ID increased over 24 h in saline-, penicillamine- and MB-OB3b-injected rats but decreased in control rats. ARBM101 almost normalised hepatic 64Cu at 24 h. CONCLUSIONS AND IMPLICATIONS: A single i.p. methanobactin dose restored biliary copper excretion in LPP rats. The effect was more pronounced with ARBM101 than with MB-OB3b. Non-ATP7B transporters must be involved because ATP7B is absent in LPP rats. Methanobactin may have therapeutic potential in Wilson disease.
AU  - Lynderup, E.M.*
AU  - Vendelbo, M.H.*
AU  - Kirk, F.T.*
AU  - Vase, K.H.*
AU  - Alstrup, A.K.O.*
AU  - Rieder, T.*
AU  - DiSpirito, A.A.*
AU  - Semrau, J.D.*
AU  - Laursen, T.L.*
AU  - Ott, P.*
AU  - Zischka, H.
AU  - Sandahl, T.D.*
C1  - 75444
C2  - 58325
CY  - 111 River St, Hoboken 07030-5774, Nj Usa
TI  - Methanobactin rapidly facilitates biliary copper excretion in a Wilson disease rat model visualised by 64Cu PET/MRI.
JO  - Br. J. Pharmacol.
PB  - Wiley
PY  - 2025
SN  - 0007-1188
ER  - 

TY  - JOUR
AB  - G protein-coupled receptors (GPCRs) play a crucial role in cell function by transducing signals from the extracellular environment to the inside of the cell. They mediate the effects of various stimuli, including hormones, neurotransmitters, ions, photons, food tastants and odorants, and are renowned drug targets. Advancements in structural biology techniques, including X-ray crystallography and cryo-electron microscopy (cryo-EM), have driven the elucidation of an increasing number of GPCR structures. These structures reveal novel features that shed light on receptor activation, dimerization and oligomerization, dichotomy between orthosteric and allosteric modulation, and the intricate interactions underlying signal transduction, providing insights into diverse ligand-binding modes and signalling pathways. However, a substantial portion of the GPCR repertoire and their activation states remain structurally unexplored. Future efforts should prioritize capturing the full structural diversity of GPCRs across multiple dimensions. To do so, the integration of structural biology with biophysical and computational techniques will be essential. We describe in this review the progress of nuclear magnetic resonance (NMR) to examine GPCR plasticity and conformational dynamics, of atomic force microscopy (AFM) to explore the spatial-temporal dynamics and kinetic aspects of GPCRs, and the recent breakthroughs in artificial intelligence for protein structure prediction to characterize the structures of the entire GPCRome. In summary, the journey through GPCR structural biology provided in this review illustrates how far we have come in decoding these essential proteins architecture and function. Looking ahead, integrating cutting-edge biophysics and computational tools offers a path to navigating the GPCR structural landscape, ultimately advancing GPCR-based applications.
AU  - Kogut-Günthel, M.M.*
AU  - Zara, Z.*
AU  - Nicoli, A.*
AU  - Steuer, A.*
AU  - Lopez-Balastegui, M.*
AU  - Selent, J.*
AU  - Karanth, S.*
AU  - Koehler, M.*
AU  - Ciancetta, A.*
AU  - Abiko, L.A.*
AU  - Hagn, F.
AU  - Di Pizio, A.*
C1  - 71550
C2  - 56275
CY  - 111 River St, Hoboken 07030-5774, Nj Usa
TI  - The path to the G protein-coupled receptor structural landscape: Major milestones and future directions.
JO  - Br. J. Pharmacol.
PB  - Wiley
PY  - 2024
SN  - 0007-1188
ER  - 

TY  - JOUR
AB  - BACKGROUND AND PURPOSE: Development and progression of heart failure (HF) involve endothelial and myocardial dysfunction as well as a dysregulation of the nitric oxide - soluble guanylyl cyclase - cyclic guanosine monophosphate (NO-sGC-cGMP) signalling pathway. Recently, we reported that the sGC stimulator riociguat (RIO) has beneficial effects on cardiac remodelling and progression of HF in response to chronic pressure overload. Here, we examined if these favourable RIO effects are also reflected in alterations of the myocardial proteome and microRNA profiles. EXPERIMENTAL APPROACH: Male C57BL/6N mice underwent transverse aortic constriction (TAC) and sham operated mice served as controls. TAC and sham animals were randomised and treated with either RIO or vehicle for five weeks, starting three weeks post-surgery when cardiac hypertrophy was established. Afterwards we performed mass spectrometric proteome analyses and microRNA sequencing of proteins and RNAs, respectively, isolated from left ventricles (LV). KEY RESULTS: TAC-induced changes of the LV proteome were significantly reduced by RIO treatment. Bioinformatics analyses revealed that RIO improved TAC-induced cardiovascular disease related pathways, metabolism and energy production, e.g. reversed alterations in the levels of myosin heavy chain 7 (MYH7), cardiac phospholamban (PLN), and ankyrin repeat domain-containing protein 1 (ANKRD1). RIO also attenuated TAC-induced changes of microRNA levels in the LV. CONCLUSION AND IMPLICATIONS: The sGC stimulator RIO has beneficial effects on cardiac structure and function during pressure overload, which is accompanied by a reversal of TAC-induced changes of the cardiac proteome and microRNA profile. Our data support the potential of RIO as a novel HF therapeutic.
AU  - Benkner, A.*
AU  - Rüdebusch, J.*
AU  - Nath, N.*
AU  - Hammer, E.*
AU  - Grube, K.*
AU  - Gross, S.*
AU  - Dhople, V.M.*
AU  - Eckstein, G.
AU  - Meitinger, T.
AU  - Kaderali, L.*
AU  - Völker, U.*
AU  - Fielitz, J.*
AU  - Felix, S.B.*
C1  - 65521
C2  - 52714
SP  - 4575-4592
TI  - Riociguat attenuates left ventricular proteome and microRNA profile changes after experimental aortic stenosis in mice.
JO  - Br. J. Pharmacol.
VL  - 179
IS  - 18
PY  - 2022
SN  - 0007-1188
ER  - 

TY  - JOUR
AB  - Background and purpose:
              
            
            Emphysema is an incurable disease characterized by loss of lung 
      tissue leading to impaired gas exchange. Wnt/β-catenin signaling is 
      reduced in emphysema and exogenous activation of the pathway in 
      experimental models in vivo and in human ex vivo lung tissue improves 
      lung function and structure. We sought to identify a pharmaceutical able
       to activate Wnt/β-catenin signaling and asses its potential to activate
       lung epithelial cells and repair.
          
        
      
        
      
      
                    
                      
      
      
        
          
            
              
                Experimental approach:
              
            
            We screened 1216 human-approved compounds for Wnt/β-catenin 
      signaling activation using luciferase reporter cells, and selected 
      candidates based on their computational predicted protein targets. We 
      further performed confirmatory luciferase reporter and metabolic 
      activity assays. Finally, we studied the regenerative potential in 
      murine adult epithelial cell derived lung organoids and in vivo using a 
      murine elastase-induced emphysema model.
          
        
      
        
      
      
                    
                      
      
      
        
          
            
              
                Key results:
              
            
            The primary screen identified 16 compounds that significantly 
      induced Wnt/β-catenin-dependent luciferase activity. Selected compounds 
      activated Wnt/β-catenin signaling without inducing cell toxicity or 
      proliferation. Two compounds were able to promote organoid formation, 
      which was reversed by pharmacological Wnt/β-catenin inhibition, 
      confirming the Wnt β-catenin-dependent mechanism of action. Amlexanox 
      was used for in vivo evaluation and preventive treatment resulted in 
      improved lung function and structure in emphysematous mouse lungs. 
      Moreover, gene expression of Hgf, an important alveolar repair marker, 
      was increased, whereas disease marker Eln was decreased, indicating that
       amlexanox induces pro-regenerative signaling in emphysema.
          
        
      
        
      
      
                    
                      
      
      
        
          
            
              
                Conclusion and implications:
              
            
            Using a drug screen based on Wnt/β-catenin activity, organoid 
      assays, and a murine emphysema model, amlexanox was identified as a 
      novel potential therapeutic for emphysema.
AU  - Costa, R.
AU  - Wagner, D.E.
AU  - Doryab, A.
AU  - De Santis, M.M.
AU  - Schorpp, K.K.
AU  - Rothenaigner, I.
AU  - Lehmann, M.
AU  - Baarsma, H.A.
AU  - Liu, X.
AU  - Schmid, O.
AU  - Campillos, M.J.
AU  - Yildirim, A.Ö.
AU  - Hadian, K.
AU  - Königshoff, M.
C1  - 62188
C2  - 50690
CY  - 111 River St, Hoboken 07030-5774, Nj Usa
SP  - 4026-4041
TI  - A drug screen with approved compounds identifies amlexanox as a novel Wnt/β-catenin activator inducing lung epithelial organoid formation.
JO  - Br. J. Pharmacol.
VL  - 178
IS  - 19
PB  - Wiley
PY  - 2021
SN  - 0007-1188
ER  - 

TY  - JOUR
AB  - Treatment of cardiac arrhythmia remains challenging due to severe side effects of common anti-arrhythmic drugs. We previously demonstrated that mitochondrial Ca2+ uptake in cardiomyocytes represents a promising new candidate structure for safer drug therapy. However, druggable agonists of mitochondrial Ca2+ uptake suitable for preclinical and clinical studies are still missing. Here, we screened 727 compounds with a history of use in human clinical trials for their potential to enhance mitochondrial Ca2+ uptake. As a primary screening platform we used a previously validated permeabilized HeLa cell-based assay and identified three candidates. To reassess these hits in a cardiac system we tested them in cultured cardiomyocytes and found that two compounds, the FDA and EMA approved drugs ezetimibe and disulfiram, were effective in stimulating SR-mitochondria Ca2+ transfer at nanomolar concentrations, which is significantly lower compared to the previously described mitochondrial Ca2+ uptake enhancers (MiCUps) efsevin, a gating modifier of the voltage-dependent anion channel 2, and kaempferol, an agonist of the mitochondrial Ca2+ uniporter. Evaluation of their efficacy in translational models revealed that both substances significantly suppressed arrhythmogenesis in an in vivo zebrafish Ca2+ overload model and suppressed arrhythmogenic signals in both, freshly isolated ventricular cardiomyocytes of a mouse model for catecholaminergic polymorphic ventricular tachycardia (CPVT) and induced pluripotent stem cell derived cardiomyocytes from a CPVT patient. Taken together we identified ezetimibe and disulfiram as novel MiCUPs and efficient suppressors of arrhythmogenesis and as such as promising candidates for future preclinical and clinical studies.
AU  - Sander, P.*
AU  - Feng, M.
AU  - Schweitzer, M.K.*
AU  - Wilting, F.*
AU  - Gutenthaler, S.M.*
AU  - Arduino, D.M.
AU  - Fischbach, S.*
AU  - Dreizehnter, L.*
AU  - Moretti, A.*
AU  - Gudermann, T.*
AU  - Perocchi, F.
AU  - Schredelseker, J.*
C1  - 62649
C2  - 51018
CY  - 111 River St, Hoboken 07030-5774, Nj Usa
TI  - Approved drugs ezetimibe and disulfiram enhance mitochondrial Ca2+ uptake and suppress cardiac arrhythmogenesis.
JO  - Br. J. Pharmacol.
PB  - Wiley
PY  - 2021
SN  - 0007-1188
ER  - 

TY  - JOUR
AB  - Background and Purpose: Heart failure is associated with an impaired NO–soluble guanylyl cyclase (sGC)–cGMP pathway and its augmentation is thought to be beneficial for its therapy. We hypothesized that stimulation of sGC by the sGC stimulator riociguat prevents pathological cardiac remodelling and heart failure in response to chronic pressure overload. Experimental Approach: Transverse aortic constriction or sham surgery was performed in C57BL/6N mice. After 3 weeks of transverse aortic constriction when heart failure was established, animals receive either riociguat or its vehicle for 5 additional weeks. Cardiac function was evaluated weekly by echocardiography. Eight weeks after surgery, histological analyses were performed to evaluate remodelling and the transcriptome of the left ventricles (LVs) was analysed by RNA sequencing. Cell culture experiments were used for mechanistically studies. Key Results: Transverse aortic constriction resulted in a continuous decrease of LV ejection fraction and an increase in LV mass until week 3. Five weeks of riociguat treatment resulted in an improved LV ejection fraction and a decrease in the ratio of left ventricular mass to total body weight (LVM/BW), myocardial fibrosis and myocyte cross-sectional area. RNA sequencing revealed that riociguat reduced the expression of myocardial stress and remodelling genes (e.g. Nppa, Nppb, Myh7 and collagen) and attenuated the activation of biological pathways associated with cardiac hypertrophy and heart failure. Riociguat reversed pathological stress response in cultivated myocytes and fibroblasts. Conclusion and Implications: Stimulation of the sGC reverses transverse aortic constriction-induced heart failure and remodelling, which is associated with improved myocardial gene expression.
AU  - Rüdebusch, J.*
AU  - Benkner, A.*
AU  - Nath, N.*
AU  - Fleuch, L.*
AU  - Kaderali, L.*
AU  - Grube, K.*
AU  - Klingel, K.*
AU  - Eckstein, G.N.
AU  - Meitinger, T.
AU  - Fielitz, J.*
AU  - Felix, S.B.*
C1  - 60888
C2  - 49644
CY  - 111 River St, Hoboken 07030-5774, Nj Usa
TI  - Stimulation of soluble guanylyl cyclase (sGC) by riociguat attenuates heart failure and pathological cardiac remodelling.
JO  - Br. J. Pharmacol.
PB  - Wiley
PY  - 2020
SN  - 0007-1188
ER  - 

TY  - JOUR
AB  - Background and Purpose In polychemotherapy protocols, that is for treatment of neuroblastoma and Ewing sarcoma, Vinca alkaloids and cell cycle-arresting drugs are usually administered on the same day. Here we studied whether this combination enables the optimal antitumour effects of Vinca alkaloids to be manifested. Experimental Approach Vinca alkaloids were tested in a preclinical mouse model in vivo and in vitro in combination with cell cycle-arresting drugs. Signalling pathways were characterized using RNA interference. Key Results In vitro, knockdown of cyclins significantly inhibited vincristine-induced cell death indicating, in accordance with previous findings, Vinca alkaloids require active cell cycling and M-phase transition for induction of cell death. In contrast, anthracyclines, irradiation and dexamethasone arrested the cell cycle and acted like cytostatic drugs. The combination of Vinca alkaloids with cytostatic therapeutics resulted in diminished cell death in 31 of 36 (86%) tumour cell lines. In a preclinical tumour model, anthracyclines significantly inhibited the antitumour effect of Vinca alkaloids in vivo. Antitumour effects of Vinca alkaloids in the presence of cytostatic drugs were restored by caffeine, which maintained active cell cycling, or by knockdown of p53, which prevented drug-induced cell cycle arrest. Therapeutically most important, optimal antitumour effects were obtained in vivo upon separating the application of Vinca alkaloids from cytostatic therapeutics. Conclusion and Implications Clinical trials are required to prove whether Vinca alkaloids act more efficiently in cancer patients if they are applied uncoupled from cytostatic therapies. On a conceptual level, our data suggest the implementation of polychemotherapy protocols based on molecular mechanisms of drugdrug interactions.
AU  - Ehrhardt, H.
AU  - Pannert, L.
AU  - Pfeiffer, S.
AU  - Wachter, F.
AU  - Amtmann, E.*
AU  - Jeremias, I.
C1  - 23746
C2  - 31284
SP  - 1558-1569
TI  - Enhanced anti-tumour effects of vinca alkaloids given separately from cytostatic therapies.
JO  - Br. J. Pharmacol.
VL  - 168
IS  - 7
PB  - Wiley-Blackwell
PY  - 2013
SN  - 0007-1188
ER  -