Islets of Langerhans

Publication Title: 
Experimental and Clinical Endocrinology & Diabetes: Official Journal, German Society of Endocrinology [and] German Diabetes Association

The aqueous extract of the fruits of Terminalia chebula Retz. has been evaluated for its antidiabetic activity in streptozotocin (STZ) induced mild diabetic rats and compared with a known drug, tolbutamide. The oral effective dose (ED) of the extract was observed to be 200 mg/kg body weight, which produced a fall of 55.6% (p<0.01) in the oral glucose tolerance test.

Author(s): 
Murali, Y. K.
Anand, P.
Tandon, V.
Singh, R.
Chandra, R.
Murthy, P. S.
Publication Title: 
Cryo Letters

Encapsulating insulin producing cells (INPCs) in an immunoisolation device have been shown to cure diabetes in rodents without the need for immunosuppression. However, micro-encapsulation in semi-solid gels raises longevity and safety concerns for future use of stem cell derived INPCs. We have focused on a durable and retrievable macro-encapsulation (> 10(6) cells) device (TheraCyte). Cryopreservation (CP) of cells preloaded into the device is highly desirable but may require prolonged exposure to cryoprotectants during loading and post-thaw manipulations.

Author(s): 
Yakhnenko, Ilya
Wong, Wallace K.
Katkov, Igor I.
Itkin-Ansari, Pamela
Publication Title: 
Biochemical Society Transactions
Author(s): 
Hales, C. N.
Desai, M.
Ozanne, S. E.
Crowther, N. J.
Publication Title: 
Mechanisms of Ageing and Development

Calorie restriction is the first and most compelling example of life extension in mammals. Much speculation about how CR works has focused on ideas of what causes aging. Since these causes themselves are much disputed, I have instead focused my thinking on lessons from simple model organisms, which have emerged from recent genetic studies. These findings can now be integrated with numerous, elegant studies on CR over the decades, which provide a treasure trove of information about physiological changes that are elicited by this regimen.

Author(s): 
Guarente, Leonard
Publication Title: 
Cell

Sir2 is an NAD-dependent deacetylase that connects metabolism with longevity in yeast, flies, and worms. Mammals have seven Sir2 homologs (SIRT1-7). We show that SIRT4 is a mitochondrial enzyme that uses NAD to ADP-ribosylate and downregulate glutamate dehydrogenase (GDH) activity. GDH is known to promote the metabolism of glutamate and glutamine, generating ATP, which promotes insulin secretion. Loss of SIRT4 in insulinoma cells activates GDH, thereby upregulating amino acid-stimulated insulin secretion.

Author(s): 
Haigis, Marcia C.
Mostoslavsky, Raul
Haigis, Kevin M.
Fahie, Kamau
Christodoulou, Danos C.
Murphy, Andrew J.
Valenzuela, David M.
Yancopoulos, George D.
Karow, Margaret
Blander, Gil
Wolberger, Cynthia
Prolla, Tomas A.
Weindruch, Richard
Alt, Frederick W.
Guarente, Leonard
Publication Title: 
Indian Journal of Experimental Biology

Diabetes mellitus was induced in male CF strain rats by streptozotocin (STZ) and hyperglycaemia and superoxide dismutase (SOD) activity of pancreatic islet cells was assessed on days 7, 14, 21 and 28. STZ induced significant hyperglycaemia and a concomitant decrease in islet cell SOD activity.

Author(s): 
Bhattacharya, S. K.
Satyan, K. S.
Chakrabarti, A.
Publication Title: 
Endocrinology

Beta-cell apoptosis occurs in diabetes mellitus (DM). Heat shock protein (HSP) 27 (human homolog of rodent HSP25) mitigates stress-induced apoptosis but has not been studied in beta-cells. We tested whether HSP27 overexpression attenuates streptozotocin (SZ)-induced DM in vivo and cytokine-induced islet apoptosis in vitro. DM was ascertained by ip glucose tolerance testing, and fasting serum insulin/glucose was measured. Pancreas was stained for insulin, HSP27, and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling, and insulin content was measured.

Author(s): 
Dai, Tiane
Patel-Chamberlin, Mina
Natarajan, Rama
Todorov, Ivan
Ma, Jun
LaPage, Janine
Phillips, Lynetta
Nast, Cynthia C.
Becerra, Diana
Chuang, Peter
Tong, Lili
de Belleroche, Jacqueline
Wells, Dominic J.
Wang, Ying
Adler, Sharon G.
Publication Title: 
Expert Opinion on Biological Therapy

IMPORTANCE OF THE FIELD: Type 1 diabetes mellitus (T1D) is a T-cell mediated autoimmune disease with selective destruction of beta cells. Immunological interventions are directed at arresting the loss of beta-cell function with the promise that this will make it easier for patients to control their glucose levels. AREAS COVERED IN THIS REVIEW: This review provides a summary of the preclinical and clinical research published between 1992 and 2009 using teplizumab and other anti-CD3 antibodies to arrest the loss of beta-cell function in new onset T1D.

Author(s): 
Masharani, Umesh B.
Becker, Joseph
Publication Title: 
Experimental Diabetes Research

Insulin resistance and loss of β-cell mass cause Type 2 diabetes (T2D). The objective of this study was to generate a nongenetic mouse model of T2D. Ninety-six 6-month-old C57BL/6N males were assigned to 1 of 12 groups including (1) low-fat diet (LFD; low-fat control; LFC), (2) LFD with 1 i.p. 40 mg/kg BW streptozotocin (STZ) injection, (3), (4), (5), (6) LFD with 2, 3, 4, or 5 STZ injections on consecutive days, respectively, (7) high-fat diet (HFD), (8) HFD with 1 STZ injection, (9), (10), (11), (12) HFD with 2, 3, 4, or 5 STZ injections on consecutive days, respectively.

Author(s): 
Gilbert, Elizabeth R.
Fu, Zhuo
Liu, Dongmin
Publication Title: 
The Journal of Nutritional Biochemistry

Chronic hyperlipidemia causes β-cell apoptosis and dysfunction, thereby contributing to the pathogenesis of type 2 diabetes (T2D). Thus, searching for agents to promote pancreatic β-cell survival and improve its function could be a promising strategy to prevent and treat T2D. We investigated the effects of kaempferol, a small molecule isolated from ginkgo biloba, on apoptosis and function of β-cells and further determined the mechanism underlying its actions.

Author(s): 
Zhang, Yanling
Zhen, Wei
Maechler, Pierre
Liu, Dongmin

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