The CD34 surface antigen is restricted to glucagon-expressing cells in the early developing bovine pancreas

Abstract

Controversy remains regarding the origin of the pancreatic endocrine cells. It is generally accepted that the majority of insulin-secreting cells derive from the endodermal epithelium of the gastrointestinal tract. The aim of this study was to determine the contribution made by a particular cluster of differentiation (CD)-positive cells to the development of the bovine endocrine pancreas. In bovine embryos and foetuses with crown to rump lengths (CRL) ranging from 1 to 47 cm, cells staining positively for CD34 and/or CD133 were always more numerous in the left lobe and body of pancreas than in the right lobe. In the early stages of pancreatic development (CRL <5 cm), CD34 and/or CD133-reactive cells were concentrated within the epithelial cell cords that form the primitive pancreas. In later developmental stages (CRL >5 cm), individual or groups of CD34 and/or CD133-reactive cells were present in newly formed acini, which bulged out from the duct system that had arisen from the cords. Some of the positively stained cells accumulated in focal areas associated with hyperplastic intra-acinar cells. These "acino-insula-like complexes" appeared to enlarge with age and develop into intralobular Islets of Langerhans. Most of the described CD34 and/or CD133-reactive cells displayed co-localisation with glucagon. A negligible number of these cells showed co-localisation with insulin. Glucagon-stained cells were distinct from insulin-stained cells and were more abundant in embryonic and early foetal pancreata. Our data demonstrate that CD34 and/or CD133-reactive cells contribute to the pancreatic alpha cell population during early foetal development in cattle.

Dual origin, development, and fate of bovine pancreatic islets

“…; Merkwitz et al. ). In brief, paraffin sections were dewaxed in xylene and brought to distilled water by hydration in graded alcohols.…”

“…As part of the immunohistochemical detection of islet hormones, pre‐absorption control experiments were performed as described in detail elsewhere (Merkwitz et al. ). In brief, to demonstrate specificity of staining, primary antibodies were pre‐incubated with a manifold excess of the corresponding target hormone before being applied to tissues.…”

“…The endocrine cells are initially dispersed as single cells, or small clusters of cells, between the exocrine precursor cells (Merkwitz et al. ), before becoming increasingly confined to morphologically tangible islets.…”

Immunohistochemistry detected and localized cannabinoid receptor type 2 in bovine fetal pancreas at late gestation

“…8 However, the expression of the components of the endocannabinoid system in the pancreas still needs to be elucidated because often there is no consensus on its distribution in the endocrine islets, for which descriptions are starkly contrasting, especially between animals of different species, such as rats and mice. 9 , 10 Moreover, in human pancreas the CB2 receptor was also found in the exocrine pancreas, unlike what had been previously reported for laboratory animals. 6 , 11 …”

Recent progress in histochemistry and cell biology

“…Unfortunately, transcription factors are intracellularly located and therefore their markers are of limited use to isolate viable stem/ progenitor cells from pancreatic tissue by fluorescenceactivated cell sorting (FACS) or magnetic-activated cell sorting (MACS). To overcome this shortage, Merkwitz et al (2011) focused on the cluster of differentiation (CD) molecules CD133 and CD34 in developing bovine endocrine pancreas, which have been also described in ductal pancreatic cells in rodents (Hori et al 2008;Sugiyama et al 2007) and humans (Karbanova et al 2008;Lardon et al 2008). CD34-and/or CD133-positive cells exhibited co-localisation with glucagon and are more abundant in embryonic and early fetal pancreata than insulin-producing cells.…”