Oral Presentation Australian Diabetes Society and the Australian Diabetes Educators Association Annual Scientific Meeting 2016

Targeting Connective Tissue Growth Factor (CTGF/CCN2) Protects Against Progressive Non-Alcoholic Steatohepatitis in a Preclinical Model Induced by High-Fat Feeding and Type 2 Diabetes. (#15)

Jing Ren 1 2 , Xiaoyu Wang 1 2 , Christine Yee 3 , Susan V. McLennan 1 2 , Stephen M. Twigg 1 2
  1. Charles Perkins Centre and Sydney Medical School, University of Sydney, Sydney, NSW, Australia
  2. Endocrinology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
  3. The University of Sydney, Sydney, NSW, Australia

As diabetes accelerates NASH, a role for the growth factor, CTGF/CCN2, in NASH pathogenesis was investigated using anti-CTGF neutralising antibody intervention in a rodent diabetes model.

Methods: Male wild type C57BL/6 mice were fed Chow or high fat diet (HFD) for 15 weeks. Then some per group were randomly assigned low dose streptozotocin (STZ: 3x65mg/kg) to induce type 2 diabetes. Some mice from each group were treated with in-house generated rabbit anti-rhCTGF neutralising antibody (i.p. 150µg per mouse twice/week), for a subsequent 10 weeks. Normal rabbit IgG (150µg per mouse twice/week) was used as control.

Results: NASH developed in HFD plus diabetes (HFD+DM) across 10 weeks of diabetes (25 weeks’ study). Anti-CTGF neutralising antibody prevented collagen-I (~10 fold) and collagen-III (~7 fold) mRNA induction (p<0.05) and showed a trend to normalise collagen IV-α1, collagen-VI and FN mRNA induction in HFD+DM. The neutralising antibody also significantly prevented pro-inflammatory MCP-1 mRNA induction (4.2 fold, p<0.05) and showed a trend to normalise TNF-α, IL-1β and IL-6 mRNA in the HFD+DM group. At the protein level, collagen accumulation by PSR stain and collagen-I protein increases in HFD+DM, were prevented (55% for PSR and 45% for collagen-I) by anti-CTGF antibody (each P<0.05). Phosphorylation of the pro-fibrotic ERK signalling pathway in liver was prevented by the in vivo neutralising antibody (p<0.05). In addition, profiles of CCN members detected in the NASH model showed CCN1 mRNA level was induced (1.7 fold) in the HFD+DM model (p<0.05), CCN3 was down-regulated in HFD+DM at mRNA and protein level, whilst there was no dysregulation for CCN4, CCN5 or CCN6. CCN3 down-regulation was prevented by the anti-CTGF neutralising antibody (p<0.05).

In summary, this in vivo data indicates that CTGF/CCN2 is a molecular target in NASH exacerbated by high fat diet with diabetes, and that ERK signalling is implicated in this process.