Systemic Sclerosis – Bleomycin-Induced Systemic Sclerosis (Osmotic Pump)

Description

In this preclinical model of systemic sclerosis, dermal and pulmonary fibrosis are induced by subcutaneously (SC) administering bleomycin over the course of 28 days. To induce disease, an osmotic pump containing bleomycin is subcutaneously implanted in the backs of anesthetized mice. Animals are evaluated daily for body weight and respiratory status. After animals are sacrificed, lung weight, collagen content and fibrosis scores are determined in both lungs and skin.

Model Systems
  • C57Bl/6 Mice
Standard Readouts
  • Percent weight change
  • Lung weight
  • Lung and skin histopathology
  • Lung mechanics
  • Lung and skin collagen content
Additional Readouts
  • BAL total and differential cell counts
  • BAL fluid and lung cytokines
  • Lung and skin immunophenotyping
  • Custom assays
Representative DataClick Image to Enlarge
Lung Histology in SC Osmotic Pump Bleomycin-Induced Systemic Sclerosis

C57Bl/6 mice are administered Bleomycin for 28 days through a SC implanted osmotic pump and Day 28 lungs are processed for histopathology. H&E-stained lungs from animals administered saline or 50 mg/kg, 100 mg/kg, or 150 mg/kg Bleomycin.

Lung Pathology Scoring in SC Osmotic Pump Bleomycin-Induced Systemic Sclerosis

C57Bl/6 mice are administered Bleomycin for 28 days through a SC implanted osmotic pump. Pathology assessment of Day 28 lungs from SC Osmotic Pump-Bleomycin administered animals. Ashcroft score is determined in H&E-stained tissue using a modified Ashcroft Scale graded from 0-8. Fibrosis score is determined in Masson’s Trichrome-stained tissue using a 0-5 semi-quantitative scoring scale of area staining positive for collagen. (*p<0.05 compared to the saline-control).

Body Weight Change and Wet Lung Weight in SC Osmotic Pump Bleomycin-Induced Systemic Sclerosis

C57Bl/6 mice are administered Bleomycin for 28 days through a SC implanted osmotic pump. Animals are weighed daily, and body weight compared to Day 0 is calculated. The AUC is calculated to compare treatment arms and is shown in the inset. Wet lung weight normalized to Day 28 body weight of Day 28 lungs from SC Osmotic Pump-Bleomycin administered animals. (*p<0.05; ***p<0.001 compared to the saline-control).

Inflammatory Cells in BAL fluid from SC Osmotic Pump Bleomycin-Induced Pulmonary Fibrosis

C57Bl/6 mice are administered Bleomycin for 28 days through a SC implanted osmotic pump and BAL fluid is assessed at 28 days for total cells and total neutrophils following administration of either 50 mg/kg, 100 mg/kg, or 150 mg/kg Bleomycin. (*p<0.05; **p<0.01 compared to the saline-control).

Functional Lung Measurements in SC Osmotic Pump Bleomycin-Induced Systemic Sclerosis

C57Bl/6 mice are administered Bleomycin for 28 days through a SC implanted osmotic pump and lung mechanics are assessed at 28 days following administration of either 50 mg/kg, 100 mg/kg, or 150 mg/kg Bleomycin. (*p<0.05; **p<0.01; ***p<0.001 compared to the saline-control).

Skin Histology in SC Osmotic Pump Bleomycin-Induced Systemic Sclerosis

C57Bl/6 mice are administered Bleomycin for 28 days through a SC implanted osmotic pump and Day 28 skin samples are processed for histopathology. H&E-stained skin from animals administered saline or 50 mg/kg, 100 mg/kg, or 150 mg/kg Bleomycin.

Skin Pathology in SC Osmotic Pump Bleomycin-Induced Systemic Sclerosis

C57Bl/6 mice are administered Bleomycin for 28 days through a SC implanted osmotic pump. Pathology assessment of Day 28 skin from SC Osmotic Pump-Bleomycin administered animals. Dermal thickness is measured, and fibrosis score is determined in Masson’s Trichrome-stained tissue using a 0-5 semi-quantitative scoring scale of area staining positive for collagen. (*p<0.05; **p<0.01 compared to the saline-control).

Daniel Lichtman

Managing Partner