J Mol Endocrinol
November 2017
Exosomes are extracellular vesicles (EVs) secreted from a majority of cell types. Exosomes play a role in healthy and pathogenic intercellular interactions via the transfer of proteins, lipids and RNA. The contents and effects of exosomes vary depending on the properties of the originating cell.
View Article and Find Full Text PDFGinseng has attracted interest because of its potential therapeutic role in diabetes therapy. No direct evidence has shown the effects of ginseng and its components, ginsenosides, on human islet β cell. In this study, we evaluated ginseng extract and ginsenosides (Rb2, Re, Rg1, Rd) on human pancreatic β cell function.
View Article and Find Full Text PDFJ Stem Cell Res Ther
April 2015
Apoptosis is one of the major factors contributing to the failure of human islet transplantation. Contributors to islet apoptosis exist in both the pre-transplantation and post transplantation stages. Factors include the islet isolation process, deterioration in vitro prior to transplantation, and immune rejection post transplantation.
View Article and Find Full Text PDFThe World Health Organization estimates that diabetes will be the fourth most prevalent disease by 2050. Developing a new therapy for diabetes is a challenge for researchers and clinicians in field. Many medications are being used for treatment of diabetes however with no conclusive and effective results therefore alternative therapies are required.
View Article and Find Full Text PDFAims: Allogeneic bone marrow (BM) has been shown to support human islet survival and function in long-term culture by initiating human islet vascularization and β-cell regeneration. Various BM subpopulations may play different roles in human islet functions and survival. In this paper we investigated the effects of BM and its subpopulations, endothelial progenitor cells (E) and mesenchymal (M) cells on human islet's β-cell function and regeneration.
View Article and Find Full Text PDFA very small tripeptide amide L-pyroglutamyl-L-histidyl-L-prolineamide (L-PHP, Thyrotropin-Releasing Hormone, TRH), was first identified in the brain hypothalamus area. Further studies found that L-PHP was expressed in pancreas. The biological role of pancreatic L-PHP is still not clear.
View Article and Find Full Text PDFOncology (Williston Park)
March 2010
The combination of oxaliplatin plus fluorouracil/leucovorin is known as the FOLFOX regimen, and it has become a standard regimen for colorectal cancer (CRC), both as adjuvant therapy and as treatment for metastatic disease. Unfortunately, platinum-based chemotherapies also produce neurotoxicity as a side effect. Neurotoxicity is the most common dose-limiting toxicity of oxaliplatin, and it is one of the major causes for patients to stop receiving chemotherapy.
View Article and Find Full Text PDFWe hypothesize that specific bone marrow lineages and cytokine treatment may facilitate bone marrow migration into islets, leading to a conversion into insulin producing cells in vivo. In this study we focused on identifying which bone marrow subpopulations and cytokine treatments play a role in bone marrow supporting islet function in vivo by evaluating whether bone marrow is capable of migrating into islets as well as converting into insulin positive cells. We approached this aim by utilizing several bone marrow lineages and cytokine-treated bone marrow from green fluorescent protein (GFP) positive bone marrow donors.
View Article and Find Full Text PDFBiochem Biophys Res Commun
September 2008
Hyperglycemia in thyrotropin-releasing hormone (TRH) null mice indicates that TRH is involved in the regulation of glucose homeostasis. Further, TRH levels in the pancreas peak during the stages of late embryonic and early neonatal beta cell development. These observations are consistent in linking TRH to islet cell proliferation and differentiation.
View Article and Find Full Text PDFBiochem Biophys Res Commun
October 2007
In this study, we have established a new strategy increasing human islet longevity utilizing allogeneic whole bone marrow (BM) co-cultured with human islets. The cultured islets' function and survival have been evaluated by analysis of insulin secretion in response to high-glucose-challenge, morphological evaluation of cell growth. Human islet only culture failed to reveal evidence of long term survival, growth or function in terms of insulin release or insulin response to glucose challenge.
View Article and Find Full Text PDFAm J Physiol Endocrinol Metab
May 2006
Thyrotropin-releasing hormone (TRH) and its receptor subtype TRH receptor-1 (TRHR1) are found in pancreatic beta-cells, and it has been shown that TRH might have potential for autocrine/paracrine regulation through the TRHR1 receptor. In this paper, TRHR1 is studied to find whether it can initiate multiple signal transduction pathways to activate the epidermal growth factor (EGF) receptor in pancreatic beta-cells. By initiating TRHR1 G protein-coupled receptor (GPCR) and dissociated alphabetagamma-complex, TRH (200 nM) activates tyrosine residues at Tyr845 (a known target for Src) and Tyr1068 in the EGF receptor complex of an immortalized mouse beta-cell line, betaTC-6.
View Article and Find Full Text PDFThyrotropin-releasing hormone (TRH), originally identified as a hypothalamic hormone, is expressed in the pancreas. The peptide has been shown to control glycemia, although the role of TRH in the pancreas has not yet been clarified. In quiescent INS-1 cells (rat immortalized beta-cell line), 200 nM of TRH for 24 hours significantly increased insulin levels in the culture medium and in cell extracts.
View Article and Find Full Text PDFA steroidal glycoside with anorectic activity in animals, termed P57AS3 (P57), was isolated from Hoodia gordonii and found to have homologies to the steroidal core of cardiac glycosides. Intracerebroventricular (i.c.
View Article and Find Full Text PDFContext: Thyrotropin releasing hormone (TRH), originally identified as a hypothalamic hormone, expresses in the pancreas. The effects of TRH such as, inhibiting amylase secretion in rats through a direct effect on acinar cells, enhancing basal glucagon secretion from isolated perfused rat pancreas, and potentiating glucose-stimulated insulin secretion in perfused rat islets and insulin-secreting clonal beta-cell lines, suggest that TRH may play a role in pancreas. TRH also enlarged pancreas and increased pancreatic DNA content but deletion of TRH gene expression caused hyperglycemia in mice, suggesting that TRH may play a critical role in pancreatic development; however, the biological mechanisms of TRH in the adult pancreas remains unclear.
View Article and Find Full Text PDFThe effects of thyroid hormone on whole body energy metabolism and compensatory effects on food intake are well established. However, the hypothalamic mechanisms that translate perceived whole body energy demands into subsequent appetitive behavior are incompletely understood. In order to address this question, we tested the effects of T3 on food intake and body weight in rats and measured neuronal Na/K ATPase activity and ATP content in the hypothalamus.
View Article and Find Full Text PDFThyrotropin-releasing hormone (TRH) is best known for its hypothalamic neuroendocrine role in regulating thyroid function. In extra-hypothalamic regions in vitro, we have shown TRH to have a protective effect against synaptic loss and neuronal apoptosis. A role for TRH in Alzheimer's disease (AD) has not been established previously.
View Article and Find Full Text PDF