Open AccessPotential role of two novel agonists of thyroid hormone receptor‐β on liver regeneration
Author(s) -
Perra Andrea,
Kowalik Marta Anna,
Cabras Lavinia,
Runfola Massimiliano,
Sestito Simona,
Migliore Cristina,
Giordano Silvia,
Chiellini Grazia,
Rapposelli Simona,
Columbano Amedeo
Publication year - 2020
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/cpr.12808
Subject(s) - triiodothyronine , endocrinology , medicine , hepatocyte , thyroid hormone receptor , agonist , liver regeneration , thyroid , hormone , bromodeoxyuridine , biology , regeneration (biology) , receptor , immunohistochemistry , microbiology and biotechnology , biochemistry , in vitro
Objectives Although the hepatomitogenic activity of triiodothyronine (T3) is well established, the wide range of harmful effects exerted by this hormone precludes its use in liver regenerative therapy. Selective agonists of the beta isoform of thyroid hormone receptor (TRβ) do not exhibit T3‐induced cardiotoxicity and show a good safety profile in patients with NASH. The aim of this study was to investigate whether two novel TRβ agonists, the prodrug TG68 and the active compound IS25 could stimulate hepatocyte proliferation without T3/TRα‐dependent side effects. Methods Rats were treated with three different doses (12.5, 25 and 50 μg/100 g body weight) for one week. Hepatocyte proliferation, liver injury and serum biochemical parameters were measured by immunohistochemistry, qRT‐PCR and Western blot. Results Both drugs increased hepatocyte proliferation as assessed by bromodeoxyuridine incorporation (from 14% to 28% vs 5% of controls) and mitotic activity. Enhanced proliferation occurred in the absence of significant signs of liver injury as shown by lack of increased serum transaminase levels or of apoptosis. No cardiac or renal hypertrophy typically associated with treatment with T3 was observed. Importantly, no proliferation of pancreatic acinar cells, such as that seen after administration of T3 or the TRβ agonist GC1 was detected following either TG68 or IS25, demonstrating the hepato‐specificity of these novel TRβ agonists. Conclusions The present study shows that TG68 and IS25 induce massive hepatocyte proliferation without overt toxicity. Hence, these agents may have a significant clinical application for regenerative therapies in liver transplantation or other surgical settings.