TNFα depleting therapy improves fertility and animal welfare in TNFα-driven transgenic models of polyarthritis when administered in their routine breeding

Abstract

Transgenic tumour necrosis factor alpha (TNFα)-driven models of polyarthritis such as the TNFΔARE mouse have proven to be invaluable in delineating aspects of inflammatory disease pathophysiology in humans. Unfortunately, the onset of joint destruction and inflammation in these models represents a significant detriment to breeding management. We examined whether TNFα depleting therapy ‘infliximab’ might represent a significant refinement in routine breeding. Clinical scores of joint inflammation were assessed in TNFΔARE males receiving either infliximab (10 mg/kg) or saline by twice-weekly intraperitoneal injection. Joint histology and bone morphology were assessed by histological analysis and micro-computed tomography (CT), respectively. Analysis of breeding was examined retrospectively in TNFΔARE males prior to, and following, regular introduction of infliximab. Clinical scores of inflammation were significantly reduced in TNFΔARE males receiving infliximab (control 6.6 arbitrary units [AU] ± 0.88 versus infliximab 4.4 AU ± 1.4; P < 0.05), while measures of pannus invasion and bone erosion by histology and micro-CT were markedly reduced. In the breeding groups, TNFΔARE males receiving infliximab injections sired more litters over their breeding lifespan (control 1.69 ± 0.22 versus infliximab 3.00 ± 0.19; P < 0.005). Furthermore, prior to infliximab, TNFΔARE males had a 26% risk of failing to sire any litters. This was reduced to 7% after the introduction of infliximab. This study is the first to report that regular administration of infliximab is effective at suppressing disease activity and improving animal welfare in TNFΔARE animals. In addition, we have shown that infliximab is highly efficacious in improving breeding behaviour and increasing the number of litters sired by TNFΔARE males.

Therapeutic glucocorticoids prevent bone loss but drive muscle wasting when administered in chronic polyarthritis

“…Interventions were designed to model initial preventative bridging therapeutic glucocorticoid treatments in early onset disease. Following the administration of vehicle and corticosterone, mice were scored twice weekly for clinical scores of disease activity and arthritic paw scores as previously described [18, 19]. Mobility of animals within cages was assessed by measuring numbers of rotations walked by animals in a 3-min period and normalised to rotations per minute to get an activity score.…”

11 Beta-hydroxysteroid dehydrogenase type 1 regulates synovitis, joint destruction, and systemic bone loss in chronic polyarthritis

“…Tg197 mice (TNF-tg) that express stabilised human TNFα mRNA on a C57BL/6J strain background were obtained from Dr George Kollias (BSRC Fleming, Athens, Greece) [ 15 ]. Animals were scored for joint inflammation using a 16 point system 9,19 : Clinical scores were calculated from measures of weight loss, behaviour, mobility, duration of joint swelling, mouse grimace and evidence of joint inflammation as previously reported [ 9 , 19 ]. At nine weeks, animals were culled and front paws, hind limbs and tibias collected.…”

“…11β-HSD1 knock out (KO) animals with global 11β-HSD1 deletion were crossed with TNF-tg animals to generate TNF‐tg 11βKO animals as previously described [ 9 ]. Breeding animals were maintained on anti-human TNFα monoclonal antibody (infliximab), as previously reported, to control inflammation and facilitate breeding [ 19 ]. Mesenchymal targeted 11β-HSD1 KO animals were created by crossing floxed HSD11B1 mice with Twist2-cre animals (where cre recombinase activity is reported to target mesenchymal derived cell populations such as osteoblasts, chondrocytes and FLS), to generate 11βHSD1flx/flx/Twist2cre animals [ [20] , [21] , [22] ].…”

“…Histochemistry was performed on paraffin-embedded 10 μm sections following decalcification in 0.5 M ethylenediaminetetraacetic acid (EDTA). Pannus size at the metatarsal-phalangeal joint interface was determined using Image J software as previously reported [ 19 ]. Sections were stained with safranin O and fast green to quantify cartilage thickness and proteoglycan loss across cartilage of the humerus/ulna interface using Image J software.…”

“…MeshLab 1.3.2 (open source software) was used to modify the raw meshes and samples were shaded in MeshLab using ambient occlusion. Meshes were scored as previously reported [ 19 ].…”