INTRODUCTION: The aging process is intricately linked to alterations in cellular and tissue structures, with the respiratory system being particularly susceptible to age-related changes. Therefore, this study aimed to profile the activity of proteases using activity-based probes in lung tissues of old and young rats, focusing on the expression levels of different, in particular cathepsins G and X and matrix Metalloproteinases (MMPs). Additionally, the impact on extracellular matrix (ECM) components, particularly fibronectin, in relation to age-related histological and ultrastructural changes in lung tissues was investigated. MATERIALS AND METHODS: Lung tissues from old and young rats were subjected to activity-based probe profiling to assess the activity of different proteases. Expression levels of cathepsins G and X were quantified, and zymography was performed to evaluate matrix metalloproteinases activity. Furthermore, ECM components, specifically fibronectin, were examined for signs of degradation in the old lung tissues compared to the young ones. Moreover, histological, immunohistochemical and ultrastructural assessments of old and young lung tissue were also conducted. RESULTS: Our results showed that the expression levels of cathepsins G and X were notably higher in old rat lung tissues in contrast to those in young rat lung tissues. Zymography analysis revealed elevated MMP activity in the old lung tissues compared to the young ones. Particularly, significant degradation of fibronectin, an essential ECM component, was observed in the old lung tissues. Numerous histological and ultrastructural alterations were observed in old lung tissues compared to young lung tissues. DISCUSSION AND CONCLUSION: The findings indicate an age-related upregulation of cathepsins G and X along with heightened MMP activity in old rat lung tissues, potentially contributing to the degradation of fibronectin within the ECM. These alterations highlight potential mechanisms underlying age-associated changes in lung tissue integrity and provide insights into protease-mediated ECM remodeling in the context of aging lungs.

• MeSH
• extracelulární matrix metabolismus   ultrastruktura   MeSH
• fibronektiny * metabolismus   MeSH
• kathepsin G metabolismus   MeSH
• krysa rodu Rattus MeSH
• lyzozomy ultrastruktura   metabolismus   MeSH
• matrixové metaloproteinasy metabolismus   MeSH
• plíce * ultrastruktura   metabolismus   MeSH
• proteasy metabolismus   MeSH
• stárnutí * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fibronektiny * MeSH
• kathepsin G MeSH
• matrixové metaloproteinasy MeSH
• proteasy MeSH

The rhabditid nematode Strongyloides stercoralis is known worldwide as the causative agent of strongyloidiasis in humans. In addition to public health concerns, S. stercoralis also infects dogs, which represent a possible reservoir for potentially zoonotic transmissions. We describe the first confirmed case of fatal disseminated infection in a dog in the Czech Republic. The microscopic and histological results were supported by a complex genotyping approach. Using high-throughput sequencing of the hypervariable region (HVR-IV) of 18S rDNA and Sanger sequencing of the partial cytochrome c oxidase subunit 1 gene (cox1), the potentially zoonotic haplotype/lineage A of S. stercoralis was confirmed, while the solely canine haplotype/lineage B was not found. The development of the disease is mainly associated with immunodeficiency, and in this case, it was triggered by inappropriate treatment, in particular the use of corticosteroids.

• Klíčová slova
• Strongyloides stercoralis, Strongyloidiasis, dog, high-throughput sequencing, zoonotic,
• MeSH
• DNA helmintů MeSH
• fatální výsledek MeSH
• fylogeneze MeSH
• genotyp MeSH
• nemoci psů * parazitologie   MeSH
• psi MeSH
• respirační komplex IV genetika   MeSH
• RNA ribozomální 18S genetika   analýza   MeSH
• Strongyloides stercoralis * genetika   izolace a purifikace   MeSH
• strongyloidiáza * veterinární   parazitologie   diagnóza   farmakoterapie   MeSH
• vysoce účinné nukleotidové sekvenování * MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• DNA helmintů MeSH
• respirační komplex IV MeSH
• RNA ribozomální 18S MeSH