Injection of bleomycin in newborn mice induces autoimmune sialitis that is transferred by CD4 T cells

Sclerotic effect of bleomycin on the submandibular gland: an experimental model

OBJECTIVES

To evaluate the sclerotic effect of bleomycin on the submandibular gland histopathologically and assess it as a possible alternative therapy for sialorrhea.

METHODS

An experimental model was designed and 18 New Zealand white rabbits were used. The rabbits were divided into two groups: a bleomycin group (n=9) and a sham group (n=9). The submandibular glands of the bleomycin group were injected with 0.3 ml bleomycin (3mg/ml) while the sham group received 0.3 ml saline. Four weeks after the procedure, the glands were removed. Histopathological studies including hematoxylin-eosin and Masson's trichrome stain were carried out. The glands were evaluated for tissue inflammation, fibrosis, edema, lipomatosis, atrophy and congestion. To investigate apoptosis, terminal deoxynucleotidyl transferase (TdT)-mediated digoxigenin-11-dUTP nick-end labeling (TUNEL) immunohistochemical staining was used.

RESULTS

In the group injected with bleomycin, inflammation (n=8), edema (n=4), fibrosis (n=3), congestion (n=4) and lipomatosis (n=7) were observed. In the sham group, only lipomatosis was observed. The TUNEL assay results were 5.06 ± 1.18 (p<0.05) for acinar cells and 8.46 ± 0.82 (p<0.05) for ductal cells in the bleomycin group. This was significantly different from the results in the sham group.

CONCLUSIONS

Apoptosis, inflammation, fibrosis, edema, lipomatosis and congestion were observed in the ductal and acinar cells of the bleomycin group. Bleomycin may be an alternative treatment for sialorrhea cases. However, more research is needed.

A genetic approach to the prediction of drug side effects: bleomycin induces concordant phenotypes in mice of the collaborative cross

The antineoplastic drug bleomycin leads to the side effect of pulmonary fibrosis in both humans and mice. We challenged genetically diverse inbred lines of mice from the Collaborative Cross with bleomycin to determine the heritability of this phenotype. Sibling pairs of mice from 40 lines were treated with bleomycin. Lung disease was assessed by scoring lung pathology and by measuring soluble collagen levels in lavage fluid. Serum micro ribonucleic acids (miRNAs) were also measured. Inbred sibling pairs of animals demonstrated high coinheritance of the phenotypes of disease susceptibility or disease resistance. The plasma levels of one miRNA were clearly correlated in sibling mice. The results showed that, as in humans, the lines that comprise the Collaborative Cross exhibited wide genetic variation in response to this drug. This finding suggests that the genetically diverse Collaborative Cross animals may reveal drug effects that might be missed if a study were based on a conventional mouse strain.

Inhibition of bleomycin-induced pulmonary fibrosis through pre-treatment with collagen type V

BACKGROUND

Tolerance to collagen structures has been shown to inhibit the progression of autoimmune scleroderma and rheumatoid arthritis. More recently, tolerance induction to collagen type V (colV) in experimental models of lung transplantation was shown to ameliorate the complex pathology known as "chronic rejection." The link between colV autoimmunity and progressive graft dysfunction and subsequent development of bronchiolitis obliterans syndrome (BOS) has been established in human lung transplant recipients. We hypothesized that intravenous injection of colV inhibits development of lung fibrosis in a bleomycin-induced lung injury mouse model.

METHODS

Experimental animals were injected intravenously with saline or colV 10 days before intratracheal instillation of bleomycin. Pulmonary inflammation was monitored and quantified for the presence of cells in the bronchoalveolar lavage (BAL) fluid by flow cytometry and histology of lung tissue.

RESULTS

ColV-pre-treated animals showed a significant reduction in lung inflammation compared with non-treated animals, according to histology and morphometry. The number of inflammatory cells in the BAL fluid was significantly reduced and associated with a lower proportion of gammadelta T cells and CD4(+) T cells in the colV-pre-treated group. Matrix metalloproteinase-2 and -9 (MMP-2 and -9; also known as gelatinase A and gelatinase B, respectively) levels in the BAL fluid were significantly reduced in colV-pre-treated mice compared with the non-treated mice. In addition, intravenous injection of colV was associated with a significant reduction in the relative expression of interleukin (IL)-6, IL-17 and IL-22 in cells present in BAL fluid at 7 and 14 days after bleomycin instillation.

CONCLUSIONS

Pre-treatment by intravenous injection of colV inhibits bleomycin-induced pulmonary fibrosis by inhibiting IL-6 and IL-17 production. Fibrosis treatment in this context therefore should target induction of colV tolerance and Th17 development.