A euglycaemic/non-diabetic perinatal environment does not alleviate early beta cell maldevelopment and type 2 diabetes risk in the GK/Par rat model.
OBJECTIVE
We used the GK/Par rat, a spontaneous model of type 2 diabetes with early defective beta cell neogenesis, to determine whether the development of GK/Par offspring in a non-diabetic intrauterine/postnatal environment would prevent the alteration of fetal beta cell mass (BCM) and ultimately decrease the risk of diabetes later in adult life.


METHODS
We used an embryo-transfer approach, with fertilised GK/Par ovocytes (oGK) being transferred into pregnant Wistar (W) or GK/Par females (pW and pGK). Offspring were phenotyped at fetal age E18.5 and at 10 weeks of age, for BCM, expression of genes of pancreatic progenitor cell regulators (Igf2, Igf1r, Sox9, Pdx1 and Ngn3), glucose tolerance and insulin secretion.


RESULTS
(1) Alterations in neogenesis markers/regulators and BCM were as severe in the oGK/pW E18.5 fetuses as in the oGK/pGK group. (2) Adult offspring from oGK transfers into GK (oGK/pGK/sGK) had the expected diabetic phenotype compared with unmanipulated GK rats. (3) Adult offspring from oGK reared in pW mothers and milked by GK foster mothers had reduced BCM, basal hyperglycaemia, glucose intolerance and low insulin, to an extent similar to that of oGK/pGK/sGK offspring. (4) In adult offspring from oGK transferred into pW mothers and milked by their W mothers (oGK/pW/sW), the phenotype was similar to that in oGK/pGK/sGK or oGK/pW/sGK offspring.


CONCLUSIONS
These data support the conclusion that early BCM alteration and subsequent diabetes risk in the GK/Par model are not removed despite normalisation of the prenatal and postnatal environments, either isolated or combined.
Université Paris-Diderot, Sorbonne Paris Cité, Laboratoire B2PE, Unité BFA, CNRS EAC 4413, Paris, France.
A
A
Chavey
D
D
Bailbé
L
L
Maulny
J P
JP
Renard
J
J
Movassat
B
B
Portha
D000818:Animals; D003924:Diabetes Mellitus, Type 2 / Q000196:embryology* / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D004195:Disease Models, Animal; D004624:Embryo Transfer; D005260:Female; D047109:Fetal Development; D018149:Glucose Intolerance / Q000196:embryology / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D007335:Insulin-Like Growth Factor II / Q000378:metabolism; D050417:Insulin-Secreting Cells / Q000378:metabolism / Q000473:pathology*; D007774:Lactation; D008297:Male; D010179:Pancreas / Q000196:embryology* / Q000378:metabolism / Q000473:pathology*; D011247:Pregnancy; D011254:Pregnancy in Diabetics / Q000503:physiopathology; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D055758:SOX9 Transcription Factor / Q000378:metabolism
D007328:Insulin; D055758:SOX9 Transcription Factor; D007335:Insulin-Like Growth Factor II; D017526:Receptor, IGF Type 1