islet cell

島細胞

関

endocrine pancreas、islets of Langerhans、pancreatic islet

同

islet cell, regeneration of

WordNet

1. small room in which a monk or nun lives (同)cubicle
2. a device that delivers an electric current as the result of a chemical reaction (同)electric cell
3. a room where a prisoner is kept (同)jail cell, prison cell
4. (biology) the basic structural and functional unit of all organisms; they may exist as independent units of life (as in monads) or may form colonies or tissues as in higher plants and animals
5. any small compartment; "the cells of a honeycomb"
6. a small unit serving as part of or as the nucleus of a larger political movement (同)cadre
7. a small island (同)islet

PrepTutorEJDIC

1. (刑務所の)『独房』;(修道院の)小さい独居室 / (ミツバチの)みつ房,巣穴 / 小さい部屋 / 『細胞』 / 電池 / 花粉室 / (共産党などの)細胞
2. 《詩》島(island)
3. 小島

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/03/12 05:30:46」(JST)

wiki en

[Wiki en表示]

Not to be confused with Langerhans cells, found in the epidermis.

Islets of Langerhans
Islet of Langerhans (mouse) in its typical proximity to a blood vessel; insulin in red, nuclei in blue.
Islets of Langerhans, hemalum-eosin stain.
Latin	insulae pancreaticae

This photograph shows a mouse pancreatic islet, an often spherical group of hormone-producing cells. Insulin is labelled here in green, glucagon in red, and the nuclei in blue.

The diagram shows the structural differences between rat islets (top) and humans islets (bottom) as well as the ventral part (left) and the dorsal part (right) of the pancreas. Different cell types are colour-coded. Rodent islets, unlike the human ones, show the characteristic insulin core.

A porcine islet of Langerhans. The left image is a brightfield image created using hematoxylin stain; nuclei are dark circles and the acinar pancreatic tissue is darker than the islet tissue. The right image is the same section stained by immunofluorescence against insulin, indicating beta cells.

The islets of Langerhans are the regions of the pancreas that contain its endocrine (i.e., hormone-producing) cells. Discovered in 1869 by German pathological anatomist Paul Langerhans at the age of 22, the islets of Langerhans constitute approximately 1 to 2% of the mass of the pancreas.

Anatomy and histology

There are about one million islets distributed throughout the pancreas of a healthy adult human,^:914 each of which measures about 0.2 mm in diameter.^:914 Each is separated from the surrounding pancreatic tissue by a thin fibrous connective tissue capsule which is continuous with the fibrous connective tissue that is interwoven throughout the rest of the pancreas.^:914 The combined mass of the islets is 1 to 1.5 grams.

Cell types

Hormones produced in the islets of Langerhans are secreted directly into the blood flow by (at least) five different types of cells. In rat islets, endocrine cell subsets are distributed as follows:

• Alpha cells producing glucagon (15–20% of total islet cells)
• Beta cells producing insulin and amylin (65–80%)
• Delta cells producing somatostatin (3–10%)
• PP cells (gamma cells) producing pancreatic polypeptide (3–5%)
• Epsilon cells producing ghrelin (<1%)

It has been recognized that the cytoarchitecture of pancreatic islets differs between species. In particular, while rodent islets are characterized by a predominant proportion of insulin-producing beta cells in the core of the cluster and by scarce alpha, delta and PP cells in the periphery, human islets display alpha and beta cells in close relationship with each other throughout the cluster.

Islets can influence each other through paracrine and autocrine communication, and beta cells are coupled electrically to other beta cells (but not to other cell types).

Paracrine feedback

The paracrine feedback system of the islets of Langerhans has the following structure:

• Insulin: activates beta cells and inhibits alpha cells
• Glucagon: activates alpha cells which activates beta cells and delta cells
• Somatostatin: inhibits alpha cells and beta cells

Electrical activity

Electrical activity of pancreatic islets has been studied using patch clamp techniques, and it has turned out that the behavior of cells in intact islets differs significantly from the behavior of dispersed cells.

Islet transplantation as a treatment for type 1 diabetes

Islet transplantation has the possibility of restoring beta cell function from diabetes, offering an alternative to a complete pancreas transplantation or an artificial pancreas.

Because the beta cells in the islets of Langerhans are selectively destroyed by an autoimmune process in type 1 diabetes, clinicians and researchers are actively pursuing islet transplantation as a means of restoring physiological beta cell function in patients with type 1 diabetes.

Recent clinical trials have shown that insulin independence and improved metabolic control can be reproducibly obtained after transplantation of cadaveric donor islets into patients with unstable type 1 diabetes.

Islet transplantation for type 1 diabetes currently requires potent immunosuppression to prevent host rejection of donor islets.

An alternative source of beta cells, such insulin-producing cells derived from adult stem cells or progenitor cells would contribute to overcoming the current shortage of donor organs for transplantation. The field of regenerative medicine is rapidly evolving and offers great hope for the nearest future. However, type 1 diabetes is the result of the autoimmune destruction of beta cells in the pancreas. Therefore, an effective cure will require a sequential, integrated approach that combines adequate and safe immune interventions with beta cell regenerative approaches.

Another potential source of beta cells may be xenotransplantation. The most likely source for xenogeneic islets for transplantation into human currently under evaluation is the pig pancreas. Interestingly, human and porcine insulin differ only for one aminoacid, and insulin extracted from porcine pancreata has been used for the treatment of patients with diabetes before the development of recombinant human insulin technology. Several studies in small and large animals models have shown that transplantation of islet cells across species is possible. However, several problems need to be overcome for porcine islet transplantation to become a viable clinical option. The immunogenicity of xenogeneic tissues may be different from and even stronger than allogeneic tissues. For instance, Galalpha1-3Galbeta1-4GlcNAc (alpha galactosidase, alpha-Gal) expressed on porcine cells represents a major barrier to xenotransplantation being the target of preformed antibodies present in human blood. Remarkable progress has been recorded in the development of genetically modified pigs lacking or overexpressing molecules that may improve acceptance of transplanted tissues across into humans. Pigs lacking alpha-Gal or overexpressing human Decay Accelerating Factor (hDAF), amongst others, have been generated to study the impact on transplanted outcome in nonhuman primate models. Another possible antigenic target is the Hanganutziu-Deichter antigen, a sialic acid found in pigs and not humans, which may contribute to immunogenicity of porcine islets. Another limitation is the risk for transmission of zoonotic infections from pigs to humans, particularly from Porcine Endogenous Retro-Viruses (PERV). Amongst the approaches proposed to overcome islet xenorejection is immunoisolation of the clusters using encapsulation techniques that may shield them from immune attack. Studies in rodents and large animals have shown great promise that justify cautious optimism for the near future. Nonrandomized, uncontrolled pilot clinical trials are current ongoing in subject with insulin-requiring diabetes to test the efficacy of encapsulation techniques to protect xenogeneic islets in the absence of chronic anti-rejection drugs.

Gallery

• Hormones/islet architecture
• Mouse islet immunostained for pancreatic polypeptide

• Mouse islet immunostained for insulin

• Mouse islet immunostained for glucagon

• Illustration of dog pancreas. 250x.

See also

• Human anatomy
• Pancreatic hormone
• Neuroendocrine tumor

References

External links

• "The Islets of Langerhans", Karolinska Institutet, Sweden
• "Islets"
• Islet Society
• MeSH A03.734.414
• "Pancreas, human – H&E", Blue Histology – Accessory Digestive Glands, School of Anatomy and Human Biology,

UpToDate Contents

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English Journal

• Influence of gender and time diet exposure on endocrine pancreas remodeling in response to high fat diet-induced metabolic disturbances in mice.

• Oliveira RB1, Maschio DA1, Carvalho CP2, Collares-Buzato CB3.
• Annals of anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft.Ann Anat.2015 Jul;200:88-97. doi: 10.1016/j.aanat.2015.01.007. Epub 2015 Mar 3.
• In this study, we investigated a possible sexual dimorphism regarding metabolic response and structural and functional adaptations of the endocrine pancreas after exposure to a high-fat diet (HFd). On chow diet, male and female C57BL/6/JUnib mice showed similar metabolic and morphometric parameters,
• PMID 25819502

• SR-135, a peroxynitrite decomposing catalyst, enhances β-cell function and survival in B6D2F1 mice fed a high fat diet.

• Johns M1, Fyalka R1, Shea JA1, Neumann WL2, Rausaria S2, Msengi EN2, Imani-Nejad M2, Zollars H2, McPherson T2, Schober J2, Wooten J3, Kwon G4.
• Archives of biochemistry and biophysics.Arch Biochem Biophys.2015 Jul;577-578:49-59. doi: 10.1016/j.abb.2015.04.005. Epub 2015 Apr 29.
• Peroxynitrite has been implicated in β-cell dysfunction and insulin resistance in obesity. Chemical catalysts that destroy peroxynitrite, therefore, may have therapeutic value for treating type 2 diabetes. To this end, we have recently demonstrated that Mn(III) bis(hydroxyphenyl)-dipyrromethene com
• PMID 25935364

• Slit and Semaphorin signaling governed by Islet transcription factors positions motor neuron somata within the neural tube.

• Lee H1, Kim M2, Kim N1, Macfarlan T3, Pfaff SL4, Mastick GS2, Song MR5.
• Experimental neurology.Exp Neurol.2015 Jul;269:17-27. doi: 10.1016/j.expneurol.2015.03.024. Epub 2015 Apr 3.
• Motor neurons send out axons to peripheral muscles while their cell bodies remain in the ventral spinal cord. The unique configuration of motor neurons spanning the border between the CNS and PNS has been explained by structural barriers such as boundary cap (BC) cells, basal lamina and radial glia.
• PMID 25843547

Japanese Journal

• 糖尿病の再生医療 : 膵島細胞シートによる膵島移植の新展開 (特集 細胞シート再生医療)

• 清水 裕史,後藤 満一,岡野 光夫
• 細胞 47(8), 386-389, 2015-07
• NAID 40020568398

• ヒト2 型糖尿病における膵島アミロイド沈着は膵島炎症を惹起し，β細胞容積を低下させる

• 鎌田 耕輔
• 弘前医学 66(1), 90-91, 2015-04-06
• NAID 120005606082

• Impact of Sox9 Dosage and Hes1-mediated Notch Signaling in Controlling the Plasticity of Adult Pancreatic Duct Cells in Mice.

• Hosokawa Shinichi,Furuyama Kenichiro,Horiguchi Masashi,Aoyama Yoshiki,Tsuboi Kunihiko,Sakikubo Morito,Goto Toshihiko,Hirata Koji,Tanabe Wataru,Nakano Yasuhiro,Akiyama Haruhiko,Kageyama Ryoichiro,Uemoto Shinji,Kawaguchi Yoshiya
• Scientific reports 5, 2015-02-17
• … In the adult pancreas, there has been a long-standing dispute as to whether stem/precursor populations that retain plasticity to differentiate into endocrine or acinar cell types exist in ducts. … Acinar cell differentiation was accelerated by Hes1 inactivation, but suppressed by NICD induction in adult Sox9-expressing cells. …
• NAID 120005575180

Related Links

• Islets of Langerhans - Wikipedia, the free encyclopedia

Hormones produced in the islets of Langerhans are secreted directly into the blood flow by (at least) five different types of cells. In rat islets, endocrine cell subsets are distributed as follows: Alpha cells producing ...

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★リンクテーブル★

リンク元	「島細胞」「膵島細胞」
拡張検索	「islet cell tumor」
関連記事	「islet」「cell」

「島細胞」

　　[★]

英

islet cell

関

ランゲルハンス島、膵島、膵内分泌部

「膵島細胞」

　　[★]

英

islet cell

関

膵島

「islet cell tumor」

　　[★] 膵島細胞腫瘍

関

pancreatic endocrine tumor

「islet」

　　[★]

• n.

• 島

• adj.

• 島状の

関

insula、insulae

　

「cell」

　　[★] 細胞