Secondly, 8–9-week-old euglycaemic female NOD mice were divided into four 16-mice experimental groups treated with human apoTf at doses of 0·1, 1 and 2·5 mg/kg or PBS six times a week for
12 consecutive weeks [13]. These treatment regimens were chosen on the basis of Temozolomide mw the different natural course of disease development in the DP-BB rats and the NOD mouse. Most female NOD mice, which exhibit a higher incidence of the disease than males, develop hyperglycaemia by the age of 35 weeks after a prolonged prediabetic period characterized from progressive insulitis that initiates from the age of 4–5 weeks [14]. In contrast, T1DM, that has a similar incidence in male and female DP-BB rats, is characterized from a more rapid course than that observed in the NOD mouse, with most of the animals developing diabetes by the age of 120 days after a short period of insulitis that develops in a non-synchronous manner between the ages of
30 and 60 days [15]. Accordingly, both in the NOD mice and the DP-BB rats, we initiate treatment under a ‘late prophylactic’ at a time when most of the animals have developed signs of insulitis. As established previously, type 1 diabetes was diagnosed in the presence of 2 consecutive days of detectable glycosuria and plasma glucose levels ≥200 mg/dl [12] using a FreeStyle Glucometer (Abbot, Abbot Park, IL, USA) and all experiments were performed in duplicate. Animals were killed when the diagnosis Selleck Erlotinib was made. To evaluate the impact of apoTf on the development of insulitis and the production of cytokines, euglycaemic 5-week-old female NOD mice were treated for 12 consecutive weeks with either apoTf (2·5 mg/kg, n = 24) or its vehicle (n = 20) and then killed to collect pancreas, blood samples, spleens and pancreatic lymph nodes for histological and immunological analyses [16]. For the histological examination of pancreatic islets, samples were fixed in Bouin’s solution embedded in paraffin for light microscopy [17]. Serial sections (5 µm thick) were stained with haematoxylin and Chorioepithelioma eosin and
only sections containing 10 or more islets were selected to be graded blindly by two observers (0, no infiltrate; 1, periductular infiltrate; 2 peri-islet infiltrate; 3 intra-islet infiltrate; and 4, intra-islet infiltrate associated with beta cell destruction) [18]. Pancreatic lymph nodes and spleens were isolated aseptically and minced to yield single-cell suspensions in culture medium with RPMI-1640 added with 10% fetal bovine serum (FBS; Sigma), 2 mM L-glutamine, 10 mM HEPES, 1 mM sodium pyruvate, 100 units/ml penicillin and 5 µg/ml streptomycin (Gibco, Grand Island, NY, USA). After centrifuging spleen cell suspensions at 300 g for 10 min, red blood cells were lysed with 3 ml of chilled red blood cell lysis buffer (Sigma) on ice for 5 min and then washed three times with chilled culture medium.