CYLD regulates keratinocyte differentiation and skin cancer progression in humans

CYLD is a gene mutated in familial cylindromatosis and related diseases, leading to the development of skin appendages tumors. Although the deubiquitinase CYLD is a skin tumor suppressor, its role in skin physiology is unknown. Using skin organotypic cultures as experimental model to mimic human skin, we have found that CYLD acts as a regulator of epidermal differentiation in humans through the JNK signaling pathway. We have determined the requirement of CYLD for the maintenance of epidermal polarity, keratinocyte differentiation and apoptosis. We show that CYLD overexpression increases keratinocyte differentiation while CYLD loss of function impairs epidermal differentiation. In addition, we describe the important role of CYLD in the control of human non-melanoma skin cancer progression. Our results show the reversion of the malignancy of human squamous cell carcinomas that express increased levels of CYLD, while its functional inhibition enhances the aggressiveness of these tumors which progress toward spindle cell carcinomas. We have found that the mechanisms through which CYLD regulates skin cancer progression include the control of tumor differentiation, angiogenesis and cell survival. These findings of the role of CYLD in human skin cancer prognosis make our results relevant from a therapeutic point of view, and open new avenues for exploring novel cancer therapies

Truncation of the Deubiquitinating Domain of CYLD in Myelomonocytic Cells Attenuates Inflammatory Responses

The cylindromatosis tumor suppressor (CYLD) is a deubiquitinating enzyme that has been implicated in various aspects of adaptive and innate immune responses. Nevertheless, the role of CYLD in the function of specific types of immune cells remains elusive. In this report we have used conditional gene targeting in mice to address the role of the deubiquitinating activity of CYLD in the myelomonocytic lineage. Truncation of the deubiquitinating domain of CYLD specifically in myelomonocytic cells impaired the development of lethal LPS-induced endotoxic shock and the accumulation of thioglycollate-elicited peritoneal macrophages. Our data establish CYLD as a regulator of monocyte-macrophage activation in response to inflammatory stimuli and identify it as a potential target for therapeutic intervention in relevant inflammatory disorders in humans

Evaluation of NV556, a Novel Cyclophilin Inhibitor, as a Potential Antifibrotic Compound for Liver Fibrosis

Hepatic fibrosis can result as a pathological response to nonalcoholic steatohepatitis (NASH). Cirrhosis, the late stage of fibrosis, has been linked to poor survival and an increased risk of developing hepatocellular carcinoma, with limited treatment options available. Therefore, there is an unmet need for novel effective antifibrotic compounds. Cyclophilins are peptidyl-prolyl cis-trans isomerases that facilitate protein folding and conformational changes affecting the function of the targeted proteins. Due to their activity, cyclophilins have been presented as key factors in several stages of the fibrotic process. In this study, we investigated the antifibrotic effects of NV556, a novel potent sanglifehrin-based cyclophilin inhibitor, in vitro and in vivo. NV556 potential antifibrotic effect was evaluated in two well-established animal models of NASH, STAM, and methionine-choline-deficient (MCD) mice, as well as in an in vitro 3D human liver ECM culture of LX2 cells, a human hepatic stellate cell line. We demonstrate that NV556 decreased liver fibrosis in both STAM and MCD in vivo models and decreased collagen production in TGFβ1-activated hepatic stellate cells in vitro. Taken together, these results present NV556 as a potential candidate for the treatment of liver fibrosis

CYLD Enhances Severe Listeriosis by Impairing IL-6/STAT3-Dependent Fibrin Production

The facultative intracellular bacterium Listeria monocytogenes (Lm) may cause severe infection in humans and livestock. Control of acute listeriosis is primarily dependent on innate immune responses, which are strongly regulated by NF-kappa B, and tissue protective factors including fibrin. However, molecular pathways connecting NF-kappa B and fibrin production are poorly described. Here, we investigated whether the deubiquitinating enzyme CYLD, which is an inhibitor of NF-kappa B-dependent immune responses, regulated these protective host responses in murine listeriosis. Upon high dose systemic infection, all C57BL/6 Cyld(-/-) mice survived, whereas 100% of wildtype mice succumbed due to severe liver pathology with impaired pathogen control and hemorrhage within 6 days. Upon in vitro infection with Lm, CYLD reduced NF-kappa B-dependent production of reactive oxygen species, interleukin (IL)-6 secretion, and control of bacteria in macrophages. Furthermore, Western blot analyses showed that CYLD impaired STAT3-dependent fibrin production in cultivated hepatocytes. Immunoprecipitation experiments revealed that CYLD interacted with STAT3 in the cytoplasm and strongly reduced K63-ubiquitination of STAT3 in IL-6 stimulated hepatocytes. In addition, CYLD diminished IL-6-induced STAT3 activity by reducing nuclear accumulation of phosphorylated STAT3. In vivo, CYLD also reduced hepatic STAT3 K63-ubiquitination and activation, NF-kappa B activation, IL-6 and NOX2 mRNA production as well as fibrin production in murine listeriosis. In vivo neutralization of IL-6 by anti-IL-6 antibody, STAT3 by siRNA, and fibrin by warfarin treatment, respectively, demonstrated that IL-6-induced, STAT3-mediated fibrin production significantly contributed to protection in Cyld(-/-) mice. In addition, in vivo Cyld siRNA treatment increased STAT3 phosphorylation, fibrin production, pathogen control and survival of Lm-infected WT mice illustrating that therapeutic inhibition of CYLD augments the protective NF-kappa B/IL-6/STAT3 pathway and fibrin production

Measurement of Electron Backscattering in the Energy Range of Neutron β\beta-Decay

We report on the first detailed measurements of electron backscattering from low Z targets at energies up to 124 keV. Both energy and angular distributions of the backscattered electrons are measured and compared with electron transport simulations based on the Geant4 and Penelope Monte Carlo simulation codes. Comparisons are also made with previous, less extensive, measurements and with measurements at lower energies.Comment: 9 pages, 8 figures, accepted for publication in Phys. Rev.

Optineurin Is Required for CYLD-Dependent Inhibition of TNFα-Induced NF-κB Activation

The nuclear factor kappa B (NF-κB) regulates genes that function in diverse cellular processes like inflammation, immunity and cell survival. The activation of NF-κB is tightly controlled and the deubiquitinase CYLD has emerged as a key negative regulator of NF-κB signalling. Optineurin, mutated in certain glaucomas and amyotrophic lateral sclerosis, is also a negative regulator of NF-κB activation. It competes with NEMO (NF-κB essential modulator) for binding to ubiquitinated RIP (receptor interacting protein) to prevent NF-κB activation. Recently we identified CYLD as optineurin-interacting protein. Here we have analysed the functional significance of interaction of optineurin with CYLD. Our results show that a glaucoma-associated mutant of optineurin, H486R, is altered in its interaction with CYLD. Unlike wild-type optineurin, the H486R mutant did not inhibit tumour necrosis factor α (TNFα)-induced NF-κB activation. CYLD mediated inhibition of TNFα-induced NF-κB activation was abrogated by expression of the H486R mutant. Upon knockdown of optineurin, CYLD was unable to inhibit TNFα-induced NF-κB activation and showed drastically reduced interaction with ubiquitinated RIP. The level of ubiquitinated RIP was increased in optineurin knockdown cells. Deubiquitination of RIP by over-expressed CYLD was abrogated in optineurin knockdown cells. These results suggest that optineurin regulates NF-κB activation by mediating interaction of CYLD with ubiquitinated RIP thus facilitating deubiquitination of RIP

Effects of immunosuppressive drugs on COVID-19 severity in patients with autoimmune hepatitis

Background: We investigated associations between baseline use of immunosuppressive drugs and severity of Coronavirus Disease 2019 (COVID-19) in autoimmune hepatitis (AIH). Patients and methods: Data of AIH patients with laboratory confirmed COVID-19 were retrospectively collected from 15 countries. The outcomes of AIH patients who were on immunosuppression at the time of COVID-19 were compared to patients who were not on AIH medication. The clinical courses of COVID-19 were classified as (i)-no hospitalization, (ii)-hospitalization without oxygen supplementation, (iii)-hospitalization with oxygen supplementation by nasal cannula or mask, (iv)-intensive care unit (ICU) admission with non-invasive mechanical ventilation, (v)-ICU admission with invasive mechanical ventilation or (vi)-death and analysed using ordinal logistic regression. Results: We included 254 AIH patients (79.5%, female) with a median age of 50 (range, 17-85) years. At the onset of COVID-19, 234 patients (92.1%) were on treatment with glucocorticoids (n = 156), thiopurines (n = 151), mycophenolate mofetil (n = 22) or tacrolimus (n = 16), alone or in combinations. Overall, 94 (37%) patients were hospitalized and 18 (7.1%) patients died. Use of systemic glucocorticoids (adjusted odds ratio [aOR] 4.73, 95% CI 1.12-25.89) and thiopurines (aOR 4.78, 95% CI 1.33-23.50) for AIH was associated with worse COVID-19 severity, after adjusting for age-sex, comorbidities and presence of cirrhosis. Baseline treatment with mycophenolate mofetil (aOR 3.56, 95% CI 0.76-20.56) and tacrolimus (aOR 4.09, 95% CI 0.69-27.00) were also associated with more severe COVID-19 courses in a smaller subset of treated patients. Conclusion: Baseline treatment with systemic glucocorticoids or thiopurines prior to the onset of COVID-19 was significantly associated with COVID-19 severity in patients with AIH.Fil: Efe, Cumali. Harran University Hospita; TurquíaFil: Lammert, Craig. University School of Medicine Indianapolis; Estados UnidosFil: Taşçılar, Koray. Universitat Erlangen-Nuremberg; AlemaniaFil: Dhanasekaran, Renumathy. University of Stanford; Estados UnidosFil: Ebik, Berat. Gazi Yasargil Education And Research Hospital; TurquíaFil: Higuera de la Tijera, Fatima. Hospital General de México; MéxicoFil: Calışkan, Ali R.. No especifíca;Fil: Peralta, Mirta. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Gerussi, Alessio. Università degli Studi di Milano; ItaliaFil: Massoumi, Hatef. No especifíca;Fil: Catana, Andreea M.. Harvard Medical School; Estados UnidosFil: Purnak, Tugrul. University of Texas; Estados UnidosFil: Rigamonti, Cristina. Università del Piemonte Orientale ; ItaliaFil: Aldana, Andres J. G.. Fundacion Santa Fe de Bogota; ColombiaFil: Khakoo, Nidah. Miami University; Estados UnidosFil: Nazal, Leyla. Clinica Las Condes; ChileFil: Frager, Shalom. Montefiore Medical Center; Estados UnidosFil: Demir, Nurhan. Haseki Training And Research Hospital; TurquíaFil: Irak, Kader. Kanuni Sultan Suleyman Training And Research Hospital; TurquíaFil: Melekoğlu Ellik, Zeynep. Ankara University Medical Faculty; TurquíaFil: Kacmaz, Hüseyin. Adıyaman University; TurquíaFil: Balaban, Yasemin. Hacettepe University; TurquíaFil: Atay, Kadri. No especifíca;Fil: Eren, Fatih. No especifíca;Fil: Alvares da-Silva, Mario R.. Universidade Federal do Rio Grande do Sul; BrasilFil: Cristoferi, Laura. Università degli Studi di Milano; ItaliaFil: Urzua, Álvaro. Universidad de Chile; ChileFil: Eşkazan, Tuğçe. Cerrahpaşa School of Medicine; TurquíaFil: Magro, Bianca. No especifíca;Fil: Snijders, Romee. No especifíca;Fil: Barutçu, Sezgin. No especifíca;Fil: Lytvyak, Ellina. University of Alberta; CanadáFil: Zazueta, Godolfino M.. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Demirezer Bolat, Aylin. Ankara City Hospital; TurquíaFil: Aydın, Mesut. Van Yuzuncu Yil University; TurquíaFil: Amorós Martín, Alexandra Noemí. No especifíca;Fil: De Martin, Eleonora. No especifíca;Fil: Ekin, Nazım. No especifíca;Fil: Yıldırım, Sümeyra. No especifíca;Fil: Yavuz, Ahmet. No especifíca;Fil: Bıyık, Murat. Necmettin Erbakan University; TurquíaFil: Narro, Graciela C.. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Bıyık, Murat. Uludag University; TurquíaFil: Kıyıcı, Murat. No especifíca;Fil: Kahramanoğlu Aksoy, Evrim. No especifíca;Fil: Vincent, Maria. No especifíca;Fil: Carr, Rotonya M.. University of Pennsylvania; Estados UnidosFil: Günşar, Fulya. No especifíca;Fil: Reyes, Eira C.. Hepatology Unit. Hospital Militar Central de México; MéxicoFil: Harputluoğlu, Murat. Inönü University School of Medicine; TurquíaFil: Aloman, Costica. Rush University Medical Center; Estados UnidosFil: Gatselis, Nikolaos K.. University Hospital Of Larissa; GreciaFil: Üstündağ, Yücel. No especifíca;Fil: Brahm, Javier. Clinica Las Condes; ChileFil: Vargas, Nataly C. E.. Hospital Nacional Almanzor Aguinaga Asenjo; PerúFil: Güzelbulut, Fatih. No especifíca;Fil: Garcia, Sandro R.. Hospital Iv Víctor Lazarte Echegaray; PerúFil: Aguirre, Jonathan. Hospital Angeles del Pedregal; MéxicoFil: Anders, Margarita. Hospital Alemán; ArgentinaFil: Ratusnu, Natalia. Hospital Regional de Ushuaia; ArgentinaFil: Hatemi, Ibrahim. No especifíca;Fil: Mendizabal, Manuel. Universidad Austral; ArgentinaFil: Floreani, Annarosa. Università di Padova; ItaliaFil: Fagiuoli, Stefano. No especifíca;Fil: Silva, Marcelo. Universidad Austral; ArgentinaFil: Idilman, Ramazan. No especifíca;Fil: Satapathy, Sanjaya K.. No especifíca;Fil: Silveira, Marina. University of Yale. School of Medicine; Estados UnidosFil: Drenth, Joost P. H.. No especifíca;Fil: Dalekos, George N.. No especifíca;Fil: N.Assis, David. University of Yale. School of Medicine; Estados UnidosFil: Björnsson, Einar. No especifíca;Fil: Boyer, James L.. University of Yale. School of Medicine; Estados UnidosFil: Yoshida, Eric M.. University of British Columbia; CanadáFil: Invernizzi, Pietro. Università degli Studi di Milano; ItaliaFil: Levy, Cynthia. University of Miami; Estados UnidosFil: Montano Loza, Aldo J.. University of Alberta; CanadáFil: Schiano, Thomas D.. No especifíca;Fil: Ridruejo, Ezequiel. Universidad Austral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. CEMIC-CONICET. Centro de Educaciones Médicas e Investigaciones Clínicas "Norberto Quirno". CEMIC-CONICET; ArgentinaFil: Wahlin, Staffan. No especifíca