Rea Kozeljacさん

“A mind that is stretched by a new experience can never go back to its old dimensions.” – O. W. Holmes

Visiting Japan had always been a dream of mine, but I could never have imagined experiencing it in such a wonderful and meaningful setting. My journey began when I applied for the exchange programme offered by my beloved MEDRI. At first, I didn’t think too much of it, as I knew that many other deserving colleagues had applied for the programme as well. When I received the news that I had been selected, I was incredibly happy and grateful for the opportunity. Still, somehow, it all felt like a fever dream — almost too good to be true. That feeling lasted until I finally arrived in sunny Nishinomiya, where Shinya-san, one of the university administrators, was waiting to welcome my colleague and me. His warm welcome was my very first impression of the Japanese people, and it immediately made me feel that this journey was going to be something truly special.

My first impression of the university could be described in just one word – huge. The whole experience initially felt overwhelming, and the university buildings seemed even more impressive. At first, I was worried that I might not fit into such a large community, but those worries quickly disappeared on Monday morning when my programme officially began. That was when I met Kuroda-sensei, the head of the Department of Immunology.

The programme prepared by Kuroda-sensei focused on lung immunology, more specifically on asthma exacerbations. Over the following three weeks, I had the opportunity to investigate inflammatory reactions induced by various allergens and other stimuli, focusing particularly on IL-1α production. Through these experiments, I discovered the power and beauty of non-clinical research, something I had never had the opportunity to experience before. With Kuroda-sensei as my mentor, every obstacle became a challenge to overcome, and every question was met with a patient and thoughtful answer. With that in mind, I would like to briefly present the main findings of my research.

The health of our loved ones, as well as our own, is something we often wish and hope for. This is why airborne particles contributing to air pollution represent an important health concern. Among these pollutants, PM2.5 particles are particularly significant. PM2.5 refers to very fine airborne particles with a diameter of 2.5 micrometres or smaller. They originate from many different sources, including vehicle exhaust, factories, power plants and wildfires. Due to their extremely small size, these particles can penetrate deep into the respiratory tract and contribute to inflammatory processes.

Interestingly, some components of PM2.5 share similarities with Asian Sand Dust, which is transported from continental Asian deserts and can reach Japan, particularly during the spring. This raises the possibility that exposure to Sand Dust may contribute to respiratory inflammation and the exacerbation of respiratory conditions in susceptible individuals.

The exact mechanisms through which particulate matter exacerbates inflammatory reactions are complex and not yet fully understood. However, interactions with immune pathways, including those involved in allergic and type 2 inflammatory responses, may contribute to these effects. An allergen is a normally harmless substance that can trigger an allergic reaction in predisposed individuals. In the presence of additional inflammatory stimuli or adjuvant effects, activation of the innate immune system can further amplify the immune response.

IL-1α is an important pro-inflammatory cytokine that can act as an early signal of tissue damage. Unlike many cytokines that are mainly produced and secreted following cellular activation, IL-1α can already be present inside cells and may be released when cells are damaged. This is particularly relevant to our experiment because particulate matter, such as Sand Dust, can induce cellular stress or damage. When the cell membrane is disrupted, intracellular IL-1α can be released into the extracellular environment, where it acts as a danger signal and promotes inflammation.

The results of my research were consistent with this mechanism. Sand Dust induced one of the strongest IL-1α responses in the supernatant and also showed high IL-1α-related activity in the mCherry reporter experiment compared with the other tested samples. Once released, IL-1α can promote local inflammatory responses and contribute to the recruitment and activation of additional immune cells. Therefore, our findings support the hypothesis that particle-induced cellular stress or damage, together with IL-1α release, may represent an important mechanism contributing to particle-induced lung inflammation.

The most memorable part of my adventure in Japan was undoubtedly the friendships I formed with Hitomi, Tamaki and Shiho. Through them, I had the opportunity to truly experience Nishinomiya in all its dimensions – both traditional and modern. As a Catholic, I had not previously been very familiar with Buddhist traditions and customs, which made discovering them even more fascinating. Visiting shrines, watching people write their wishes on ema, and seeing them draw omikuji to seek guidance about their fortune and future was a completely new and memorable experience for me. It allowed me to experience a culture different from my own and appreciate the traditions that have been preserved for generations. At the same time, Hitomi, Tamaki and Shiho introduced me to another side of Japan – everyday student life. Spending time together, sharing conversations, exploring the city and simply enjoying ordinary moments allowed me to experience Japan not only as a visitor, but also, even if only briefly, as a part of their everyday life. Those moments and friendships are something I will carry with me long after returning home.

To conclude, I would like to express my sincere gratitude to Hyogo Medical University for its incredible hospitality and kindness. From all the administrative support to the guest house that became my home away from home, I felt welcomed throughout my entire stay. However, more than the university, the research or the places I visited, the true highlight of this exchange was the people I met along the way. They are the reason these three weeks passed much faster than I ever wanted them to. For the knowledge, the experiences, the memories and, most importantly, the people – thank you from the bottom of my heart.

本当にありがとうございました。