Hyaluronidases are groups of enzymes that degrade hyaluronic acid (HA). To stop enzymatic hydrolysis we modified testicular hyaluronidase (HYAL) by activated polyethylene oxide with the help of electron-beam synthesis. As a result we received pegylated hyaluronidase (pegHYAL). Spiperone is a selective D2 dopamine receptor antagonist. It was demonstrated on the model of a single bleomycin damage of alveolar epithelium that during the inflammatory phase monotherapy by pegHYAL or spiperone reduced the populations of hematopoietic stem /progenitor cells in the lung parenchyma. PegHYAL also reduced the levels of transforming growth factor (TGF)-β, interleukin (IL)-1β, tumor necrosis factor (TNF)-α in the serum and lungs, while spiperone reduced the level of the serum IL-1β. Polytherapy by spiperone and pegHYAL caused the increase of the quantity of hematopoietic stem/ progenitor cells in the lungs. Such an influx of blood cell precursors was observed on the background of considerable fall level of TGF-β and the increase level of TNF-α in the serum and lungs. These results show pegHYAL reduced the bleomycin-induced fibrosis reaction (production and accumulation of collagen) in the lung parenchyma. This effect was observed at a single and repetitive bleomycin damage of alveolar epithelium, the antifibrotic activity of pegHYAL surpassing the activity of testicular HYAL. The antifibrotic effect of pegHYAL is enhanced by an additional instillation of spiperone. Therapy by pegHYAL causes the flow of CD31‒CD34‒CD45‒CD44+CD73+CD90+CD106+-cells into the fibrous lungs. These cells are incapable of differentiating into fibroblast cells. Spiperone instillation separately or together with pegHYAL reduced the MSC-like cells considerably. These data enable us to assume, that pegHYAL is a new and promising instrument both for preventive and therapy of toxic pneumofibrosis. The blockage of D2 dopamine receptors with the following change of hyaluronan matrix can be considered as a new strategy in treatment of pneumofibrosis.

On the model of toxic diffuse pulmonary fibrosis induced by intratracheal administration of bleomycin, we studied reactions of the blood system, content of stem cells, committed hemopoietic and stromal progenitor cells in the bone marrow, spleen and peripheral blood of C57Bl/6 mice. It was shown that the development of diffuse pulmonary fibrosis was accompanied by hyperplasia of bone marrow hemopoiesis and leukocytosis in the peripheral blood. Activation of the erythroid and granulocytic hemopoietic stems was related to stimulation of hemopoietic stem cells (polypotent cells, granulocyte/erythroid/macrophage/megakaryocyte precursor cells) and committed erythroid and myeloid progenitor cells in the bone marrow. At the same time, the number of stromal precursors increased. Bleomycin increased the count of hemopoietic stem cells the peripheral blood and spleen and reduced the content of mesenchymal stem cells in the spleen and bone marrow.

The effects of antiserotonin preparation on the development of the connective tissue in the lungs, reaction of the blood system, and the content of hemopoietic stem cells, committed hemopoietic and stromal precursors in BM, spleen, and peripheral blood were studied on C57Bl/6 mice with experimental toxic lung fibrosis caused by intratracheal administration of bleomycin. It was demonstrated that the antiserotonin drug inhibits the growth of the connective tissue in the lungs and attenuates the course inflammatory process primarily due to inhibition of the granulocytic lineage, which was related to suppression of hemopoietic stem cells. Reduced content of the stromal precursor cells in BM and spleen was noted.

Using the model of lung fibrosis induced by intratracheal administration of bleomycin we studied anti-fibrotic activity of combined treatment with neuroleptic haloperidol and hyaluronidase immobilized on polyethylene oxide using electron-beam synthesis. It was shown that successive administration of immobilized hyaluronidase and the neuroleptic drug inhibits deposition of collagen fibers in the bleomycin-treated lungs. Combined treatment with the test compounds reduced swelling of the alveolar epithelium, exudation and infiltration of the alveolar interstitium and alveolar passages by inflammatory cells, and desquamation of alveolocytes into alveolar lumen, so that the alveolar-capillary membrane function was preserved.

We studied differentiation of multipotent mesenchymal stromal cells (MMSC) of the lungs of C57Bl/6 mice with bleomycin-induced pneumofibrosis. Adherent mononuclear cells found in mouse lungs demonstrated mesenchymal phenotype and expressed CD44, CD73, CD90, and CD106, but not CD31, CD34, and CD45. The cells with MMSC characteristics differentiate in vitro into various cells of stromal lines (chondrocytes, osteogenic cells, adipocytes, and fibroblasts). Bleomycin increased the growth rate of MMSC and selectively promoted their differentiation towards fibroblast cells.