Periodic Reporting for period 1 - redOXFluxMAP (The map of Redox Intracellular Signaling in skin physiology)
Reporting period: 2023-05-01 to 2025-04-30
redOXFluxMAP project explored an intriguing question: how does hydrogen peroxide (H2O2)—a chemical many of us know from bleaching hair or cleaning wounds—actually help our skin heal and regenerate? While H2O2 is often seen as harmful, it also acts as an important messenger in our bodies. Imagine it as a tiny signal flare inside our skin cells, sending urgent messages that tell cells when to grow, divide, or repair damage. This kind of communication is called cell signaling, and H2O2 serves as a redox messenger—a molecule that carries information by changing the balance of oxidation, much like how changing the volume on a radio can send different signals. Our skin relies on carefully timed bursts of H2O2 to trigger these responses. Too much H2O2 can cause damage, while too little can slow down healing. The project focused on understanding how skin cells control these signals and, importantly, how H2O2 moves through different parts of the cell. Redox biology—the study of these oxidation-reduction processes—is a relatively new area of cell biology centered on how H2O2 acts as a signaling molecule. Remarkably, H2O2 is mostly produced inside membrane-enclosed organelles within the cell, such as the endoplasmic reticulum (ER), mitochondria, and outside the cell. Because of this, how easily H2O2 can move between compartments shapes the strength, timing, and duration of its signals. Special protein channels called aquaporins (AQPs) help regulate H2O2’s movement through cell membranes. Some of these AQPs are found on the cell surface, while others are located on membranes inside the cell, like the ER membrane. For example, AQP11 on the ER membrane controls the flow of H2O2 from the ER into the cytoplasm, influencing cellular redox balance. In the skin, redox balance is particularly important. H2O2 helps regulate the growth and maturation of keratinocytes—the main cell type in the outer layer of skin. These cells need the right amount of H2O2 signals to multiply during wound healing and to properly mature to form an effective skin barrier. Too much or too little disrupts this process, potentially leading to problems like chronic wounds or impaired skin function. Emerging research, including work from our team, suggests that specific regions within cells—like the boundary between the ER and cytoplasm—serve as specialized “control centers” for H2O2 signaling. Understanding how these zones function during skin cell differentiation and regeneration is key to unlocking new treatments for skin diseases. Based on this knowledge, the redOXFluxMAP project aimed to map these redox signals with precise spatial and temporal detail, focusing on how H2O2 fluxes influence keratinocyte behavior during skin renewal. The goal was to uncover both the sources of H2O2 signals and their targets within cells, building a comprehensive picture that could guide future therapies targeting redox-related skin conditions.
The redOXFluxMAP project was composed by six Work Packages (WPs), each focused on different aspects of the project. WP1 focused on understanding how hydrogen peroxide-mediated signals operate in skin cells. This research led to one scientific paper currently under review and a second one being prepared. The results were also shared through two published conference papers and presented at three international congresses, with another congress participation already scheduled. Additionally, the fellow supervised a bachelor’s thesis related to this research. Key scientific achievements included confirming where specific H2O2 sensors are located inside skin cells and optimizing how these cells are grown to better study early development. The work highlighted the important role of certain AQPs, in moving hydrogen peroxide through compartments, promoting signals that help skin respond to injuries. WP2 investigated how the protein AQP11 regulates hydrogen peroxide, in skin cells. Although the initial goal was to identify specific target proteins, the research uncovered unexpected findings leading to promising new directions. The work resulted in four peer-reviewed abstracts and included participation in three international conferences—one oral presentation and two posters. Manuscripts based on these findings are currently in preparation. The team identified a previously unknown microdomain within cells where H2O2 is highly concentrated, suggesting it may serve as a specialized site for localized and tightly regulated cell signaling. WP3 aimed to develop a reliable three-dimensional (3D) skin model that can be used to study hydrogen peroxide-mediated signals. This model overcomes previous challenges with skin cell experiments and better replicates real skin structure. The research produced one important manuscript currently under peer review and presentations at two international congresses. This advanced 3D skin model is expected to be a valuable tool for future studies of skin biology and wound healing. The final three work packages (WP4-6) focused on managing the project, supporting the fellow’s career development, and disseminating results. Activities included career planning with the supervisor, teaching undergraduates, and mentoring students. The fellow also actively engaged in scientific conferences and public outreach to promote understanding of skin biology and H2O2 signaling to both experts and the general public. In conclusion, the redOXFluxMAP project resulted in multiple scientific publications, conference contributions, and the development of an advanced 3D skin model, significantly deepening our understanding of skin biology and hydrogen peroxide-mediated signaling in tissue repair. These outcomes provide a solid foundation for future investigations and position both the fellow and the host institution as leaders in the field. Throughout the fellowship, the team actively disseminated findings through high-level scientific platforms and public engagement initiatives, ensuring strong visibility and alignment with MSCA objectives. The rich dataset generated will continue to support further publications and drive progress in redox biology and skin research.
The redOXFluxMAP project set out to comprehensively explore how H2O2 influences keratinocyte differentiation and skin regeneration. Through its dedicated efforts, the project has made significant advances, revealing novel mechanisms and enhancing the tools available for studying skin biology. A pivotal discovery was the critical role of aquaporins, particularly AQP8, in controlling H2O2 transport across keratinocyte cell membranes. This protein is instrumental in generating localized redox signals, which are essential for effective wound healing and overall skin health. Complementing this, the project also uncovered a unique oxidative microdomain at the interface between the endoplasmic reticulum and the cytosol. This finding provides fresh insight into how cells precisely regulate oxidative signaling within specific subcellular compartments. Another major achievement was the creation of a more realistic 3D human skin model using HaCaT cells, a well-established keratinocytic cell line. This success stemmed from an improved culture method, which included specific vitamin supplementation that promoted proper cell differentiation and organization. This enhanced model offers a reliable platform for conducting proof-of-concept experiments, crucially avoiding the variability often associated with the use of primary keratinocytes. Furthermore, it enables the detailed, real-time study of redox processes, opening new possibilities for a deeper understanding of oxidative stress, inflammation, and skin healing. Looking ahead, the potential impact of redOXFluxMAP extends far beyond fundamental research. It directly addresses a major global health issue, given that over 25% of people worldwide suffer from skin disorders, many of which are linked to oxidative stress. By enabling precise monitoring of H2O2 in advanced 3D skin models, the project directly responds to significant medical and societal needs. These sophisticated models hold strong potential for widespread use across the pharmaceutical, cosmetic, and biomedical industries for applications such as drug screening, safety testing, and personalized diagnostics. With the global skin health market, particularly wound care, projected to exceed $22 billion, the project’s innovations offer substantial commercial opportunities. Moreover, the fellow’s specialized expertise in redox biology and tissue engineering provides a solid foundation for future partnerships with industry or the establishment of new ventures focused on advanced skin health technologies.