Diminished inhibitory effect of noradrenaline on insulin release from mouse islets transplanted to kidney

Insulin release is inhibited by adrenergic alpha-2 agonism in normal beta-cells. To test whether the inhibitory response to noradrenaline is modified by transplantation, we studied insulin release from freshly isolated islets and from syngeneic islets transplanted under the kidney capsule of non-diabetic C57BL/6 mice. When perifused in vitro, fresh islets, as well as grafts harvested 1 or 3 weeks after transplantation, reacted to 2.5 mol/l noradrenaline with a complete inhibition of insulin release induced by 16.7 mmol/ld-glucose. In contrast, islet grafts harvested after 6, 12, or 21 weeks exhibited a conspicuous insulin secretory response to 16.7 mmol/l glucose in the presence of 2.5 mol/l noradrenaline. Also a concentration of 0.25 mol/l, noradrenaline inhibited the glucose-induced insulin release from fresh islets but not from 6-week-old islet grafts. It is concluded that transplantation under the kidney capsule induces a decreased inhibitory responsiveness to noradrenaline in islet grafts.     

Islet and beta cell volumes in offspring of severely diabetic (ketotic) chinese hamsters

Summary Chinese hamsters bred at the Upjohn Laboratory were studied at varying ages from 15 days to 19 months. Diabetic animals three to six months and those 10 to 19 months of age were glycosuric and hyper glycemic; there was ketonuria and ketonemia but blood glycerol and fasting plasma insulin levels were low when these values were compared with normal control animals of comparable ages. Using quantitative technics developed in our laboratory, the volumes of islets, beta cells and beta granules were diminished. The increase in volume of nongranular cells is progressive with duration of diabetes. Glycogen infiltration was observed in beta cells of these diabetic animals. — Although offspring (fifteen-day-old weanlings) of the mating of two severely diabetic (ketotic) animals were normoglycemic and glycosurie, their plasma insulin levels were higher than those of their controls. The islet volume was somewhat higher than that of the controls but the beta cells were degranulated both by light and electron microscopy; the beta cells exhibited glycogen infiltration. These results are consistent with the thesis that the primary defect is in insulin biosynthesis.

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Insel- und B-Zell-Volumen im Pankreas von Nachkommen schwer diabetischer chinesischer Hamster

Zusammenfassung Mit von den Autoren entwickelten morphometrischen Methoden wurde das B-Zell-Volumen im Pankreas chinesischer Hamster der Upjohn Kolonie bestimmt. Das Alter der untersuchten Tiere schwankte zwischen 15 Tagen und 19 Monaten. Die diabetischen Tiere waren entweder 3 – 6 oder 10–19 Monate alt. Sie waren hyperglykämisch und glykosurisch, teilweise bestand Ketonurie. Die Plasmainsulin- und Glyzerin-Konzentrationen im Gesamtblut waren niedriger als diejenigen gleichaltriger Normaltieren erniedrigt. Bei diabetisehen Tieren waren B-Zell- und-Granula-Volumen vermindert. Mit zunehmender Dauer des Diabetes nahm der Anteil der nicht granulierten B-Zellen zu. Die B-Zellen diabetischer Tiere zeigten Glykogeninfiltration. 15 Tage alte Nachkommen zweier ketotisch-diabetischer Eltern waren normoglykämisch, hatten aber im Vergleich zu gleichaltrigen Kontrolltieren erhöhte Plasmainsulin-Konzentrationen. Das Inselzellvolumen war gegenüber der Norm erhöht, aber die B-Zellen waren degranuliert und zeigten Glykogeninfiltration. Diese Resultate stimmen mit der Hypothese überein, daß der primäre Defekt, der beim chinesischen Hamster die Entwicklung eines diabetischen Syndroms zur Folge hat, die Biosynthese des Insulins betrifft.

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Le, volume des îlots de Langerhans et des cellules B du pancréas de la progéniture de hamsters chinois sévèrement diabetiques

Résumé Des hamsters chinois provenant de la colonie des Laboratoires Upjohn ont été étudiés à différents âges allant de 15 jours à 19 mois. On trouve une glycosurie et une hyperglycémie chez les animaux diabétiques de 3 à 6 mois et chez ceux de 10 à 19 mois. On observe également une cétonurie et une cétonémie, mais les taux de glycérol sanguin et les taux d'insuline plasmatique à jeun sont bas par comparaison à ceux détectés chez des témoins d'âge comparable. Le volume des îlots, des cellules et des granules, mesuré par des méthodes quantitatives élaborées dans notre laboratoire, est diminué. Le volume des cellules non-granulées augmente progressivement avec la durée du diabète. On observe une infiltration de glycogène dans les cellules B des animaux diabétiques. Bien que la progéniture, âgée de 15 jours, de deux animaux sévèrement diabétiques (avec cétose) ait des taux normaux de glycémie et une glycosurie, leur insulinémie est plus élevée que celle mesurée chez les témoins. Le volume de leurs îlots est un peu plus grand que celui des contrôles, mais, en microscopie optique et électronique, les cellules sont dégranulées et montrent une infiltration de glycogène. Ces résultats confirment l'hypothèse que le défaut primaire est au niveau de la biosynthèse de l'insuline.

     

Cholestatic Liver Injury After Biliary Reconstruction Impairs Transplanted Islet Viability and Function

Islet autotransplantation following total pancreatectomy differs from allograft transplantation with respect to the requirement of biliary reconstruction. Although it is known that careful consideration should be given to postoperative cholestatic liver injury after biliary reconstruction, its direct effects on transplanted islets have not been completely elucidated. In this study, we developed a murine model of postoperative cholestatic liver injury after biliary reconstruction with islet autotransplantation that involved syngeneic intraportal islet transplantation into chemically induced diabetic mice and common bile duct ligation. We assessed the viability and function of the transplanted islets. The impaired viability of transplanted islets and increased blood glucose levels indicated restoration of the diabetic state after common bile duct ligation in this murine model. Furthermore, impaired islet viability and function occurred earlier in the transplanted islets than in the surrounding liver tissues, which was consistent with the faster and higher expression of oxidative stress markers in the transplanted islets. Transplanted islets may be more vulnerable to oxidative stress caused by cholestatic liver injury than the surrounding liver tissue. Therefore, patients should be intensively managed after total pancreatectomy with islet autotransplantation to preserve viability and function of the transplanted islets.     

Trefoil factor 3 in perinatal pancreas is increased by gestational low protein diet and associated with accelerated β-cell maturation

The endocrine pancreas expands markedly in the first postnatal days and the insulin producing β-cells initiate a functional maturation preceded by a morphological change of the islets of Langerhans. Trefoil factor 3 (TFF3) is a secreted peptide expressed in intestinal epithelia, where it promotes migration, but its role in the pancreas is not characterized. The aim of this study was to examine the expression and function of TFF3 in perinatal rat pancreas, ex vivo cultured fetal rat pancreas and in the rat β-cell line INS-1E.

Control or gestational low-protein diet perinatal rat pancreas was harvested at embryonic day 20 (E20), day of birth (P0) and postnatal day 2 (P2). TFF3 mRNA was upregulated 4.5-fold at P0 vs. E20 and downregulated again at P2. In protein-undernourished pups induction of TFF3 at P0 was further increased to 9.7-fold and was increased at P2. TFF3 caused tyrosine phosphorylation of EGFR in INS-1E β-cells, and purified recombinant TFF3 increased both attachment and spreading of INS-1E β-cells. In ex vivo cultures of collagenase digested fetal rat pancreas, a model of perinatal β-cell maturation, TFF3 increased cellular spreading as well as insulin mRNA levels. TFF3 also increased the expression of Pref1/Dlk1 that shares similarities in expression and regulation with TFF3.

These results suggest that TFF3 may promote adhesion and spreading of cells to accelerate β-cell maturation. This study indicates a functional role for TFF3 in pancreatic β-cell maturation in the perinatal period, which is altered by low protein diet during gestation.     

Nodal Langerhans cell histiocytosis with prominent eosinophilic emperipolesis

Multinucleated giant cells of osteoclastic type are known to occur in nodal and extranodal lesions of Langerhans cell histiocytosis (LCH). These giant cells are thought to be derived from phagocytic histiocytes, which correlate with the degree of necrosis in LCH lesions. Emperipolesis commonly seen in Rosai–Dorfman disease is a distinct phenomenon characterized by intact phagocytosed cells in an intracytoplasmic vacuole protected from proteolytic digestion. We present a case of emperipolesis of inflammatory cells especially of eosinophils by multinucleated giant cells of Langhans type in a lymph node involved by LCH—a finding that has not been described previously in the literature. Diagn. Cytopathol. 2015;43:1000–1002. © 2015 Wiley Periodicals, Inc.     

A case of invasive Langerhans cell histiocytosis localizing only in the lung and diagnosed as pneumothorax in an adolescent female

In infants, Langerhans cell histiocytosis (LCH) is associated with poor clinical outcomes as Langerhans cells invade and damage multiple organs, a presentation that is different from that in adults. Here, we present a case of a 15-year-old female who visited ourclinic complaining of right chest pain and dyspnea. She was diagnosed with right pneumothorax by chest X-ray. Chest computed tomography showed multiple cystic changes in the bilateral lung. Additionally, bullous lesions occupying the upper lobe and multiple white tiny nodules on the surface of the lung were observed by thoracoscopy. These nodules comprised proliferating atypical CD1a/S-100-positive cells invading the pulmonary parenchyma, leading to the diagnosis of LCH. Because of the extensive invasion into the pulmonary parenchyma, chemotherapy was administered. This case of LCH was unique in that the age of onset was atypical and the tumor cells occupied a single organ, despite their malignant behavior.     

Programmed cell death 1 (PD-1) regulates the effector function of CD8 T cells via PD-L1 expressed on target keratinocytes

Programmed cell death 1 (PD-1) is an inhibitory molecule expressed by activated T cells. Its ligands (PD-L1 and -L2; PD-Ls) are expressed not only by a variety of leukocytes but also by stromal cells. To assess the role of PD-1 in CD8 T cell-mediated diseases, we used PD-1-knockout (KO) OVA-specific T cell-receptor transgenic (Tg) CD8 T cells (OT-I cells) in a murine model of mucocutaneous graft-versus-host disease (GVHD). We found that mice expressing OVA on epidermal keratinocytes (K14-mOVA mice) developed markedly enhanced GVHD-like disease after transfer of PD-1-KO OT-I cells as compared to those mice transferred with wild-type OT-I cells. In addition, K14-mOVA × OT-I double Tg (DTg) mice do not develop GVHD-like disease after adoptive transfer of OT-I cells, while transfer of PD-1-KO OT-I cells caused GVHD-like disease in a Fas/Fas-L independent manner. These results suggest that PD-1/PD-Ls-interactions have stronger inhibitory effects on pathogenic CD8 T cells than does Fas/Fas-L-interactions. Keratinocytes from K14-mOVA mice with GVHD-like skin lesions express PD-L1, while those from mice without the disease do not. These findings reflect the fact that primary keratinocytes express PD-L1 when stimulated by interferon-γ in vitro. When co-cultured with K14-mOVA keratinocytes for 2 days, PD-1-KO OT-I cells exhibited enhanced proliferation and activation compared to wild-type OT-I cells. In addition, knockdown of 50% PD-L1 expression on the keratinocytes with transfection of PD-L1-siRNA enhanced OT-I cell proliferation. In aggregate, our data strongly suggest that PD-L1, expressed on activated target keratinocytes presenting autoantigens, regulates autoaggressive CD8 T cells, and inhibits the development of mucocutaneous autoimmune diseases.     

Small Nerve Fiber Damage and Langerhans Cells in Type 1 and Type 2 Diabetes and LADA Measured by Corneal Confocal Microscopy

PurposeIncreased corneal and epidermal Langerhans cells (LCs) have been reported in patients with diabetic neuropathy. The aim of this study was to quantify the density of LCs in relation to corneal nerve morphology and the presence of diabetic neuropathy and to determine if this differed in patients with type 1 diabetes mellitus (T1DM), type 2 diabetes mellitus (T2DM), and latent autoimmune diabetes of adults (LADA).MethodsPatients with T1DM (n = 25), T2DM (n = 36), or LADA (n = 23) and control subjects (n = 23) underwent detailed assessment of peripheral neuropathy and corneal confocal microscopy. Corneal nerve fiber density (CNFD), branch density (CNBD), length (CNFL) and total, immature and mature LC densities were quantified.ResultsLower CNFD (P < 0.001), CNBD (P < 0.0001), and CNFL (P < 0.0001) and higher LC density (P = 0.03) were detected in patients with T1DM, T2DM, and LADA compared to controls. CNBD was inversely correlated with mature (r = –0.5; P = 0.008), immature (r = –0.4; P = 0.02) and total (r = –0.5; P = 0.01) LC density, and CNFL was inversely correlated with immature LC density (r = –0.4; P = 0.03) in patients with T1DM but not in patients with T2DM and LADA.ConclusionsThis study shows significant corneal nerve loss and an increase in LC density in patients with T1DM, T2DM, and LADA. Furthermore, increased LC density correlated with corneal nerve loss in patients with T1DM.