Publications by authors named "Rocco Falchetto"

9 Publications

  • Page 1 of 1

Farnesoid X Receptor Agonism, Acetyl-Coenzyme A Carboxylase Inhibition, and Back Translation of Clinically Observed Endpoints of Lipogenesis in a Murine NASH Model.

Hepatol Commun 2020 Jan 8;4(1):109-125. Epub 2019 Nov 8.

Disease Area X Novartis Institutes for BioMedical Research Basel Switzerland.

A promising approach for the treatment of nonalcoholic steatohepatitis (NASH) is the inhibition of enhanced hepatic lipogenesis (DNL), which is the synthesis of fatty acids from nonlipid sources. This study assesses three approaches to DNL suppression in a newly developed dietary NASH mouse model: i) dietary intervention (switch from NASH-inducing diet to normal diet); ii) inhibition of acetyl-coenzyme A carboxylase (ACC), the enzyme catalyzing the rate-limiting step in DNL; and iii) activation of farnesoid X receptor (FXR), a major transcriptional regulator of DNL. C57BL/6J mice on a high-fat diet combined with consumption of a fructose-sucrose solution developed several of the liver histologic features seen in human disease, including steatosis, inflammation, and fibrosis, accompanied by elevated fibrosis biomarkers and liver injury enzymes. Obesity and metabolic impairments were associated with increased intestinal permeability and progression to adenoma and hepatocellular carcinoma. All three approaches led to resolution of established NASH with fibrosis in mice; however, some differences were noted, e.g., with respect to the degree of hepatic steatosis attenuation. While ACC inhibition resulted in elevated blood triglycerides and peripheral obesity, FXR activation prevented peripheral obesity in NASH mice. Comparative transcriptome analysis underlined the translatability of the mouse model to human NASH and revealed novel mechanistic insights into differential regulation of lipid, inflammatory, and extracellular matrix pathways by FXR agonism and ACC inhibition. Novel insights are provided on back translation of clinically observed endpoints of DNL inhibition by targeting ACC or FXR, which are promising therapeutic options for the treatment of NASH, in a newly developed diet-induced NASH mouse model.
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http://dx.doi.org/10.1002/hep4.1443DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6939503PMC
January 2020

The Patient Perspective: A Matter of Minutes.

Authors:
Rocco Falchetto

Patient 2020 02;13(1):1-6

International Porphyria Patient Network (IPPN), Hegarstrasse 3, 8032, Zürich, Switzerland.

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http://dx.doi.org/10.1007/s40271-019-00399-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6957536PMC
February 2020

Patient Preferences in the Medical Product Lifecycle.

Patient 2020 02;13(1):7-10

Department of Cardiology, Department of Epidemiology, University Medical Center Groningen, Groningen, The Netherlands.

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http://dx.doi.org/10.1007/s40271-019-00400-yDOI Listing
February 2020

A natural ligand for the orphan receptor GPR15 modulates lymphocyte recruitment to epithelia.

Sci Signal 2017 Sep 12;10(496). Epub 2017 Sep 12.

Novartis Institutes for BioMedical Research, CH-4056 Basel, Switzerland.

GPR15 is an orphan G protein-coupled receptor (GPCR) that is found in lymphocytes. It functions as a co-receptor of simian immunodeficiency virus and HIV-2 and plays a role in the trafficking of T cells to the lamina propria in the colon and to the skin. We describe the purification from porcine colonic tissue extracts of an agonistic ligand for GPR15 and its functional characterization. In humans, this ligand, which we named GPR15L, is encoded by the gene and has some features similar to the CC family of chemokines. was found in some human and mouse epithelia exposed to the environment, such as the colon and skin. In humans, was also abundant in the cervix. In skin, was readily detected after immunologic challenge and in human disease, for example, in psoriatic lesions. Allotransplantation of skin from -deficient mice onto wild-type mice resulted in substantial graft protection, suggesting nonredundant roles for GPR15 and GPR15L in the generation of effector T cell responses. Together, these data identify a receptor-ligand pair that is required for immune homeostasis at epithelia and whose modulation may represent an alternative approach to treating conditions affecting the skin such as psoriasis.
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http://dx.doi.org/10.1126/scisignal.aal0180DOI Listing
September 2017

Oxysterols direct immune cell migration via EBI2.

Nature 2011 Jul 27;475(7357):524-7. Epub 2011 Jul 27.

Euroscreen S.A., 6041 Gosselies, Belgium.

Epstein-Barr virus-induced gene 2 (EBI2, also known as GPR183) is a G-protein-coupled receptor that is required for humoral immune responses; polymorphisms in the receptor have been associated with inflammatory autoimmune diseases. The natural ligand for EBI2 has been unknown. Here we describe the identification of 7α,25-dihydroxycholesterol (also called 7α,25-OHC or 5-cholesten-3β,7α,25-triol) as a potent and selective agonist of EBI2. Functional activation of human EBI2 by 7α,25-OHC and closely related oxysterols was verified by monitoring second messenger readouts and saturable, high-affinity radioligand binding. Furthermore, we find that 7α,25-OHC and closely related oxysterols act as chemoattractants for immune cells expressing EBI2 by directing cell migration in vitro and in vivo. A critical enzyme required for the generation of 7α,25-OHC is cholesterol 25-hydroxylase (CH25H). Similar to EBI2 receptor knockout mice, mice deficient in CH25H fail to position activated B cells within the spleen to the outer follicle and mount a reduced plasma cell response after an immune challenge. This demonstrates that CH25H generates EBI2 biological activity in vivo and indicates that the EBI2-oxysterol signalling pathway has an important role in the adaptive immune response.
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http://dx.doi.org/10.1038/nature10280DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4297623PMC
July 2011

Identification of a potent Janus kinase 3 inhibitor with high selectivity within the Janus kinase family.

J Med Chem 2011 Jan 14;54(1):284-8. Epub 2010 Dec 14.

Novartis Institutes for BioMedical Research, Forum 1, Novartis Campus, Basel, Switzerland.

We describe a synthetic approach toward the rapid modification of phenyl-indolyl maleimides and the discovery of potent Jak3 inhibitor 1 with high selectivity within the Jak kinase family. We provide a rationale for this unprecedented selectivity based on the X-ray crystal structure of an analogue of 1 bound to the ATP-binding site of Jak3. While equally potent compared to the Pfizer pan Jak inhibitor CP-690,550 (2) in an enzymatic Jak3 assay, compound 1 was found to be 20-fold less potent in cellular assays measuring cytokine-triggered signaling through cytokine receptors containing the common γ chain (γC). Contrary to compound 1, compound 2 inhibited Jak1 in addition to Jak3. Permeability and cellular concentrations of compounds 1 and 2 were similar. As Jak3 always cooperates with Jak1 for signaling, we speculate that specific inhibition of Jak3 is not sufficient to efficiently block γC cytokine signal transduction required for strong immunosuppression.
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http://dx.doi.org/10.1021/jm101157qDOI Listing
January 2011

Absolute quantification of monoclonal antibodies in biofluids by liquid chromatography-tandem mass spectrometry.

Anal Chem 2008 Feb 25;80(4):1290-6. Epub 2008 Jan 25.

BioAnalytical Sciences, Discovery Technologies, Novartis Institutes for BioMedical Research, Novartis, Basel, Switzerland.

The development of a quantification method for monoclonal antibodies in serum has been accomplished by high-performance liquid chromatography multiple reactions monitoring mass spectrometry. A human monoclonal antibody (HmAb) was used as the model protein for method development and validation. A peptide from the CDR3-region of its heavy chain was selected and used for quantifying the entire mAb. This signature peptide served as a template for the internal standard. Prior to mass spectrometric analysis approximately 50% of the total serum protein content was removed by albumin depletion. The accuracy of the method ranged between 99 and 112% in cynomolgus monkey serum. The intra-assay coefficient of variation (CV) was lower than 4% at 4 microg/mL and 200 microg/mL HmAb (n = 3). The CV at 400 microg/mL corresponded to 9% (n = 3). In addition, the interassay variation was investigated in a male cynomolgus serum pool and in a female cynomolgus serum pool. The CV for the male cynomolgus pool at 4 microg/mL HmAb was 7% (n = 3). The CV obtained from the female pool was 8% (n = 3), at 4 microg/mL. The dynamic range of the method was 3 orders of magnitude. After albumin depletion of 25 microL of serum, a lowest limit of quantification of 2 microg/mL HmAb was reached in both human and cynomolgus monkey samples.
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http://dx.doi.org/10.1021/ac702115bDOI Listing
February 2008

Quality control in combinatorial chemistry: determinations of amounts and comparison of the "purity" of LC-MS-purified samples by NMR, LC-UV and CLND.

J Comb Chem 2005 May-Jun;7(3):364-71

Novartis Institutes for BioMedical Research, Lead Synthesis & Chemogenetics and Analytical & Imaging Sciences, CH-4002 Basel, Switzerland.

The absolute purities of 20 purified samples from a combinatorial library have been determined by a new method that uses the DMSO sidebands [1J[13C-1H]] as an internal standard for quantification. The obtained absolute amounts are compared with the amounts of sample obtained by weighing, with the calculated weights obtained by chemiluminescent nitrogen detection (CLND) chromatography and with the relative purities obtained by LC-UV chromatography.
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http://dx.doi.org/10.1021/cc049850rDOI Listing
July 2005

Two-dimensional electrophoresis protein profiling and identification in rat bronchoalveolar lavage fluid following allergen and endotoxin challenge.

Proteomics 2004 Jul;4(7):2101-10

Novartis Institutes for Biomedical Research, Central Technologies-Analytical & Imaging Sciences Unit, CH-4002 Basel, Switzerland.

The protein content of bronchoalveolar lavage fluid (BALF) from actively sensitised Brown Norway (BN) rats challenged with allergen (ovalbumin, OA) and from naïve Brown Norway rats challenged with endotoxin (lipopolysaccharide, LPS) was analyzed and compared to healthy controls treated with vehicle only. BALF proteins were analyzed by one-dimensional (1-D) and two-dimensional (2-D) gel electrophoresis and identified by peptide mass fingerprinting matrix assisted laser desorption/ionization-mass spectrometry (MALDI-MS) or nanoliquid chromatography-tandem MS (nanoLC-MS/MS) after in-gel trypsin digestion of selected 2-D gel spots. Our study shows that the BALF protein profile is significantly different in animals after allergen (OA) or endotoxin (LPS) challenge as compared to controls, concerning the content of proteins derived from plasma or produced locally in the lung. In both challenges the following proteins presented patterns which differed qualitatively compared to control: T-kininogen I and II, alpha-1-antitrypsin, calgranulin A, fetuin A and B, and haptoglobin. Other proteins were diminished in both challenges, such as Clara cell 10 kDa secretory protein (CC10) and pulmonary surfactant associated protein B (SP-B); c-reactive protein increased in the OA-challenge and decreased in the LPS-challenge, and pulmonary surfactant associated protein A (SP-A) was decreased in the OA-challenge and was not significantly changed in the LPS-challenge. The identified proteins could be important not only for the diagnosis but have also interesting implications for medical treatment of lung inflammatory conditions. Furthermore, even if based on a limited number of animals, our results are of interest for the identification of lung protein markers and a better understanding of the mechanisms involved in the pathogenesis of lung diseases.
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http://dx.doi.org/10.1002/pmic.200300727DOI Listing
July 2004