Immunohistochemical study of secretory proteins in the developing human exocrine pancreas

Carrère, Jacqueline; Figarella‐Branger, Dominique; Senegas-Balas, F.; Figarella, Catherine; Guy-Crotte, Odette

doi:10.1111/j.1432-0436.1992.tb00680.x

Cited by 40 publications

(37 citation statements)

References 29 publications

(20 reference statements)

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“…However, other investigators have found the gene to be expressed in the exocrine portion of the adult pancreas (12,15), where it encodes pancreatic stone protein, a major constituent of the exocrine pancreatic secretion (38). In the human fetal pancreas, the reg protein has previously been detected in the acinar cells, which were found to be weakly immunoreactive from 16 to 27 wk gestational age, at which point the staining became more intense, and markedly increased at birth (39). We observed very low expression of the reg gene before 16 wk gestation, at which time a dramatic increase was seen.…”

Section: Discussionmentioning

confidence: 67%

“…The nonparallel appearance of secretory proteins in the fetal exocrine pancreas has previously been reported (39,45,46), perhaps reflecting the adaptive ability of the pancreas to the changing composition of the amniotic fluid. Inasmuch as amniotic fluid is devoid of starch, it is not surprising that amylase activity has not been detected in the fetal pancreas (45,46).…”

Section: Discussionmentioning

confidence: 99%

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Developmental Gene Expression in the Human Fetal Pancreas

et al. 1994

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Differential developmental regulation of pancreasspecific genes has not been reported for the human fetal pancreas. We have therefore undertaken a systematic, quantitative analysis of the transcriptional levels of various genes in the human pancreas at different stages of fetal and postnatal development. Using sensitive ribonuclease protection assays, in situ hybridization, and the polymerase chain reaction, our results indicate the following: 1 ) Transcriptional levels of insulin and amylin remain lower in the fetal than in the adult pancreas, whereas glucagon and somatostatin mRNA levels are consistently greater after 14 wk gestation than postnatally. These results are in agreement with previous immunohistochemical studies of these gene products.2 ) The reg gene exhibits a 20-fold increase in mRNA levels after 16 wk gestation. The gene is expressed exclusively in the acinar cells and does not colocalize with insulin. This restricted exocrine expression does not indicate a direct role for the reg gene in islet development. 3 ) Glucose transporter 2 and glucokinase mRNA are detectable as early as 13 wk gestation and remain low throughout development. Glucose transporter 1 reaches adult transcriptional levels by 18 wk gestation. The early detection of glucose transporter 2 and glucokinase implies that lack of expression of these "glucose sensor" genes does not account for the known insensitivity of the fetal p-cells to glucose. (Pediafr Res 36: 537-544, 1994)

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Section: Discussionmentioning

confidence: 67%

Section: Discussionmentioning

confidence: 99%

Developmental Gene Expression in the Human Fetal Pancreas

et al. 1994

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“…However, one study by Yang et al ( 1 ) showed PLRP 1 and 2 mRNAs are expressed from the 16th week of gestation in the human fetal pancreas whereas PTL begins to be expressed after birth. In another study, Carrère et al ( 12 ), using an immunostaining technique, found that BSSL/ CEH protein is detectable earlier than lipase protein in the human exocrine fetal pancreas. This study most likely did not discriminate between PTL and the related proteins, PLRP1 and 2, as they share a high degree of homology and the antibodies used were not necessarily specifi c for PTL.…”

Section: Hydrolysis Of Tg and Product Uptake Are Dependent On The Bilmentioning

confidence: 99%

“…The TG substrate contained triolein and trace amounts of 3 H-triolein emulsifi ed with 10% gum arabic in EM and the RE substrate contained 95% triolein, 5% retinyl palmitate, and a trace amount of retinyl palmitate [pal- [1][2][3][4][5][6][7][8][9][10][11][12][13][14] C] emulsifi ed with gum arabic in EM. The CE substrate was prepared similar to the RE substrate but with 5% cholesteryl oleate and a trace amount of cholesteryl [1-14 C] oleate.…”

Section: Experimental Designmentioning

confidence: 99%

BSSL and PLRP2: key enzymes for lipid digestion in the newborn examined using the Caco-2 cell line

Andersson

Hernell

Bläckberg

et al. 2011

Journal of Lipid Research

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“…In the rat and mouse, PTL is not expressed until close to weaning. A careful analysis of human newborns has not been done although they have low levels of lipase activity in pancreatic fluid up to 6-12 months of age, suggesting absent or low levels of PTL expression (23)(24)(25)(26). Even though the analysis is incomplete, it is clear that these closely related genes show discoordinate temporal and species-specific expression.…”

Section: Physiologymentioning

confidence: 99%

The triglyceride lipases of the pancreas

Lowe

2002

Journal of Lipid Research

258

204

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Pancreatic triglyceride lipase (PTL) and its protein cofactor, colipase, are required for efficient dietary triglyceride digestion. In addition to PTL, pancreatic acinar cells synthesize two pancreatic lipase related proteins (PLRP1 and PLRP2), which have a high degree of sequence and structural homology with PTL. PLRP1 has no known activity. PTL and PLRP2 differ in substrate specificity, behavior in bile salts and dependence on colipase. Each protein has a globular amino-terminal (N-terminal) domain, which contains the catalytic site for PTL and PLRP2, and a ␤ -sandwich carboxyl-terminal (C-terminal) domain, which includes the predominant colipase-binding site for PTL. In The digestion and absorption of long-chain triglycerides, the major dietary lipid, is a highly efficient process involving several distinct steps, emulsification, hydrolysis by lipases into fatty acids and monoacylglycerols, dispersion of these products into an aqueous environment, and uptake by enterocytes (1). The first step, emulsification, begins with cooking, continues with chewing, and finishes in the stomach (1, 2). Several triglyceride lipases participate in the second step, the hydrolysis of dietary lipids. Hydrolysis starts in the stomach where, in humans, gastric lipase cleaves 15-20% of the fatty acids and goes to completion in the upper small intestine where the emulsion mixes with pancreatic juice containing several lipases capable of hydrolyzing triglycerides (3, 4). The resulting products form mixed micelles with bile salts, which, in turn, are absorbed by enterocytes.The efficient digestion of dietary fats is all the more remarkable when the physical properties of the emulsion particles and the environment of the duodenum are considered (2, 5, 6). The emulsion particles form a complicated oil phase that creates an interface with the aqueous environment the lipases prefer. Virtually all of the dietary triglyceride and diglycerides segregate into the core of the emulsion particle, which is covered by a monolayer or multilamellar phase of mostly polar lipids, phospholipids, and fatty acids, with a small percentage of cholesterol and of triglycerides. Additionally, denatured dietary proteins, dietary oligosaccharides, and bile salts coat the surface, adding further complexity to the interface. As lipolysis proceeds, the composition and physical properties of the interface change continuously as products form and leave the interface (1). Consequently, the interface separates triglyceride lipases from the bulk of their substrate and presents obstacles to productive binding with interfacial substrate; that is, digestive lipases must associate with the scarce substrate in the interface and avoid nonproductive adsorption by the abundant amphipathic lipids.The exocrine pancreas secretes several lipases that have overcome the kinetic challenges presented by emulsion particles. One of these lipases, pancreatic triglyceride lipase (PTL), predominates in vivo as evidenced by the fat malabsorption in patients with isolated PTL defic...

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Immunohistochemical study of secretory proteins in the developing human exocrine pancreas

Cited by 40 publications

References 29 publications

Developmental Gene Expression in the Human Fetal Pancreas

Developmental Gene Expression in the Human Fetal Pancreas

BSSL and PLRP2: key enzymes for lipid digestion in the newborn examined using the Caco-2 cell line

The triglyceride lipases of the pancreas

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