Recombinant HvRNASET2 protein induces marked connective tissue remodelling in the invertebrate model Hirudo verbana

• Published in: Cell and tissue research 2020-06, Vol.380 (3), p.565-579
• Main Authors: Baranzini, Nicolò, Weiss-Gayet, Michèle, Chazaud, Bénédicte, Monti, Laura, de Eguileor, Magda, Tettamanti, Gianluca, Acquati, Francesco, Grimaldi, Annalisa
• Format: Article
• Language: English
• Subjects: Animals; Bacterial infections; Biomedical and Life Sciences; Biomedicine; Body wall; Cell activation; Cell Line; Collagen; Collagen Type I - metabolism; Connective tissue; Connective Tissue - drug effects; Connective Tissue - physiology; Connective tissues; Fibroblast growth factor 2; Fibroblast growth factors; Fibroblasts; Fibroblasts - drug effects; Health aspects; Hirudo medicinalis - drug effects; Hirudo verbana; Human Genetics; Humans; Immune response; Inflammation; Injection; Invertebrates; Macrophages; Molecular Medicine; Proteins; Proteomics; Receptor, Fibroblast Growth Factor, Type 1 - metabolism; Recombinant Proteins - pharmacology; Regular Article; Ribonuclease; Ribonuclease Rh; Ribonuclease S; Ribonuclease T2; Ribonucleases - pharmacology
• ISSN: 0302-766X; 1432-0878
• DOI: 10.1007/s00441-020-03174-0

The RNASET2 ribonuclease, belonging to the highly conserved RH/T2/s RNase gene family, has been recently shown to modulate inflammatory processes in both vertebrates and invertebrates. Indeed, the RNASET2 protein acts as a chemoattractor for macrophages in both in vitro and in vivo experimental settings and its expression significantly increases following bacterial infections. Moreover, we recently observed that injection of human recombinant RNASET2 protein in the body wall of the medicinal leech (a consolidated invertebrate model for both immune response and tissue regeneration) not only induced immune cell recruitment but also apparently triggered massive connective tissue remodelling as well. Based on these data, we evaluate here a possible role of leech recombinant RNASET2 protein (r Hv RNASET2) in connective tissue remodelling by characterizing the cell types involved in this process through histochemical, morphological and immunofluorescent assays. Moreover, a time-course expression analysis of newly synthesized pro-collagen1α1 (COL1α1) and basic FGF receptor (bFGFR, a known fibroblast marker) following r Hv RNASET2 injection in the leech body wall further supported the occurrence of r Hv RNASET2-mediated matrix remodelling. Human MRC-5 fibroblast cells were also investigated in order to evaluate their pattern of collagen neosynthesis driven by r Hv RNASET2 injection. Taken together, the data reported in this work provide compelling evidence in support of a pleiotropic role for RNASET2 in orchestrating an evolutionarily conserved crosstalk between inflammatory response and regenerative process, based on macrophage recruitment and fibroblast activation, coupled to a massive extracellular reorganization.