Proceeding of Veterinary and Animal Science Days 2016, 8th- 10th June, Milan, Italy 

HAF © 2013 

Vol. III, No. 1s  ISSN: 2283-3927 

   

 

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Keywords 

Epigenetic Conversion, 

Pancreatic Differentiation, 

Glucose Concentration, 

Physiological Environment 

 

CORRESPONDING AUTHOR 

Alessandro Zenobi 

alessandro.zenobi@unimi.it 

 

JOURNAL HOME PAGE 

riviste.unimi.it/index.php/haf 

High glucose concentrations are required 

for endocrine pancreatic differentiation 

of mammalian adult fibroblasts. 

 

A. Zenobia *, F. Gandolfia, T. A. L. Brevini a 

a Department of Health, Animal Science and Food Safety, University of 
Milan, Via Celoria 10, 20133 Milan, Italy 

 

 

Abstract 
Epigenetic conversion overcomes the stability of a terminally differentiated cell, allowing phenotype 

switch and providing an unlimited source of autologous cells of a different type. It is based on the 

exposure to an epigenetic modifier that increases cell plasticity, followed by a differentiation protocol. 

In our work we treat mammalian dermal fibroblasts with the demethylating agent 5-azacytidine. Cell 

differentiation is directed toward the endocrine pancreatic lineage, with a sequential combination of 

key growth factors. The overall duration of the process is 36 days (Pennarossa, 2013; Brevini, 2015; Brevini, 

2015). However, this protocol, as well as all differentiation procedures described in the literature, uses 

high and non-physiological concentrations of glucose. Here we report experiments aimed at 

investigating whether the use of lower glucose concentrations, that more closely mimic the in vivo 

physiological environment, can support fibroblast conversion into β-like cells. To do so, cells were 

cultured as described above, but using lower and more physiological glucose levels, namely 5.5 and 8.5 

mM that correspond to normoglycaemia before and after meals (International Diabetes Federation, 

2007). Our results show that mammalian cells are not able to differentiate into insulin secreting cells in 

a low glucose environment. In particular, cells do not aggregate into pancreatic islet structures and 

display an altered gene expression pattern for several early pancreatic markers, when compared to the 

standard trend obtained with 17.5 mM of glucose. These results suggest that high glucose levels are 

essential for the achievement of the endocrine pancreatic differentiation process in mammalian cells 

and appear to be crucial for functional efficiency and morphological organization. 
 

References 

Brevini, T.A.L., Pennarossa, G., Acocella, F., Brizzola, S., Zenobi, A., Gandolfi, F., 2015. Skin derived insulin-secreting cells as a potential therapy 

for diabetes in the dog. The Veterinary Journal 211, 52-56; 

Brevini, T.A.L., Pennarossa, G., Maffei, S., Zenobi, A., Gandolfi, F., 2015. Epigenetic conversion as a safe and simple method to obtain insulin-

secreting cells from adult skin fibroblasts. JoVe 109, e53880; 

International Diabetes Federation, 2007. Guidance for Management of Postmeal Glucose; 

Pennarossa, G., Maffei S., Campagnol, M., Tarantini, L., Gandolfi, F., Brevini, T.A.L. 2013. Brief demethylation step allows the conversion of 

adult human skin fibroblasts into insulin-secreting cells. PNAS 110(22), 8948–8953. 

http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en