328 research outputs found
p63 is a key regulator of iRHOM2 signalling in the keratinocyte stress response.
Hyperproliferative keratinocytes induced by trauma, hyperkeratosis and/or inflammation display molecular signatures similar to those of palmoplantar epidermis. Inherited gain-of-function mutations in RHBDF2 (encoding iRHOM2) are associated with a hyperproliferative palmoplantar keratoderma and squamous oesophageal cancer syndrome (termed TOC). In contrast, genetic ablation of rhbdf2 in mice leads to a thinning of the mammalian footpad, and reduces keratinocyte hyperproliferation and migration. Here, we report that iRHOM2 is a novel target gene of p63 and that both p63 and iRHOM2 differentially regulate cellular stress-associated signalling pathways in normal and hyperproliferative keratinocytes. We demonstrate that p63-iRHOM2 regulates cell survival and response to oxidative stress via modulation of SURVIVIN and Cytoglobin, respectively. Furthermore, the antioxidant compound Sulforaphane downregulates p63-iRHOM2 expression, leading to reduced proliferation, inflammation, survival and ROS production. These findings elucidate a novel p63-associated pathway that identifies iRHOM2 modulation as a potential therapeutic target to treat hyperproliferative skin disease and neoplasia
Tylosis with oesophageal cancer: Diagnosis, management and molecular mechanisms
Research on iRHOM2 in the Kelsell group is funded by an MRC project grant,
a MRC Clinical Fellowship (to TM) and a Cancer Research UK program grant
Rhomboid family member 2 regulates cytoskeletal stress-associated Keratin 16.
Keratin 16 (K16) is a cytoskeletal scaffolding protein highly expressed at pressure-bearing sites of the mammalian footpad. It can be induced in hyperproliferative states such as wound healing, inflammation and cancer. Here we show that the inactive rhomboid protease RHBDF2 (iRHOM2) regulates thickening of the footpad epidermis through its interaction with K16. K16 expression is absent in the thinned footpads of irhom2-/- mice compared with irhom2+/+mice, due to reduced keratinocyte proliferation. Gain-of-function mutations in iRHOM2 underlie Tylosis with oesophageal cancer (TOC), characterized by palmoplantar thickening, upregulate K16 with robust downregulation of its type II keratin binding partner, K6. By orchestrating the remodelling and turnover of K16, and uncoupling it from K6, iRHOM2 regulates the epithelial response to physical stress. These findings contribute to our understanding of the molecular mechanisms underlying hyperproliferation of the palmoplantar epidermis in both physiological and disease states, and how this 'stress' keratin is regulated
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Cleavage of the pseudoprotease iRhom2 by the signal peptidase complex reveals an ER-to-nucleus signaling pathway.
iRhoms are pseudoprotease members of the rhomboid-like superfamily and are cardinal regulators of inflammatory and growth factor signaling; they function primarily by recognizing transmembrane domains of their clients. Here, we report a mechanistically distinct nuclear function of iRhoms, showing that both human and mouse iRhom2 are non-canonical substrates of signal peptidase complex (SPC), the protease that removes signal peptides from secreted proteins. Cleavage of iRhom2 generates an N-terminal fragment that enters the nucleus and modifies the transcriptome, in part by binding C-terminal binding proteins (CtBPs). The biological significance of nuclear iRhom2 is indicated by elevated levels in skin biopsies of patients with psoriasis, tylosis with oesophageal cancer (TOC), and non-epidermolytic palmoplantar keratoderma (NEPPK); increased iRhom2 cleavage in a keratinocyte model of psoriasis; and nuclear iRhom2 promoting proliferation of keratinocytes. Overall, this work identifies an unexpected SPC-dependent ER-to-nucleus signaling pathway and demonstrates that iRhoms can mediate nuclear signaling
Exercise Addiction in Athletes and Leisure Exercisers: The Moderating Role of Passion
Background and aims Recently, empirical research has linked obsessive passion to the etiology of exercise addiction, and the conceptual reason behind the fact that the latter is more prevalent in athletes than leisure exercisers has been challenged. The aim of this study was to determine the link between exercise addiction and harmonious passion, obsessive passion, and dedication to sports, in the context of athletic levels. A sample comprised of low- and high-level competitive athletes and non-competitive leisure exercisers (n = 313) was examined, in a cross-sectional design, in which participants completed the Spanish validated versions of the Exercise Addiction Inventory (Sicilia, AlÃas-GarcÃa, Ferriz, & Moreno-Murcia, 2013) and Passion Scale (Chamarro et al., 2015). Results Obsessive passion and dedication to sports emerged as strong predictors of exercise addiction. Competitive athletes scored higher than leisure exercisers on all measures. Athletes competing at low and high levels only differed in dedication to their sports from each other. Team-sports athletes reported greater harmonious and obsessive passions, and dedication to sports, but not different exercise addictions, than people taking part in individual sports. Conclusions The concept of exercise addiction is not a plain and independent construct and may not reflect a psychological dysfunction in the athletic population. Athletes could interpret exercise addiction screening-items differently from non-athletes. Athletes in team sports report greater passion and dedication than those practicing individual sports
ADAM17/EGFR axis promotes transglutaminase-dependent skin barrier formation through phosholipase C gamma 1 and protein kinase C pathways
This work was supported by the German Research Foundation DFG (SFB 850/B6) and by the Fritz-Thyssen
foundation (Az.10.14.2.150) to C.-W.F and the Medical Research Council (MR/L010402/1) to D.P.K
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