scholarly journals Wingless-Type MMTV Integration Site Family Member 5a Is a Key Secreted Islet Stellate Cell-Derived Product that Regulates Islet Function

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Xu ◽  
Jun Liang ◽  
H. F. Geng ◽  
Jun Lu ◽  
Rui Li ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Family Member ◽  
Stellate Cell ◽  
Integration Site ◽  
Islet Function ◽  
Insulin Production ◽  
The Status ◽  
Secretory Products

Background. Emerging evidence suggests that T2DM is attributable to the dysfunction of β-cells and the activation of islet stellate cells (ISCs). The wingless-type MMTV integration site family member 5a (Wnt5a)/frizzled 5 (Fzd5) signalling pathway might take part in this process. Our study is aimed at defining the status of ISCs during β-cell insulin secretion homeostasis by determining the role of the Wnt5a protein in the regulation of insulin production. We examined the effects of the status of ISCs on β-cell insulin secretion in normoglycemic db/m and hyperglycaemic db/db mice. Methods. iTRAQ protein screening and RNA interference were used to determine novel ISC-derived secretory products that may use other mechanisms to influence the function of islets. Results. We showed a significant reduction in insulin secretion by β-cells in vitro when they were cocultured with db/db ISCs compared to when they were cocultured with ISCs isolated from normoglycemic db/m mice; in addition, both Wnt5a and its receptor Fzd5 were more highly expressed by quiescent ISCs than by activated db/db ISCs. Treatment with exogenous Wnt5a increased the secretion of insulin in association with the deactivation of ISCs. Conclusion. Our observations revealed that the Wnt5a protein is a key effector of ISC-mediated improvement in islet function.

scholarly journals Investigations on the Role of the MicroRNA-338-5p/Wnt Family Member 2B (WNT2B) Axis in Regulating the Pathogenesis of Nasopharyngeal Carcinoma (NPC)

2021 ◽  
Vol 11 ◽  
Author(s):  
Suzhen Wang ◽  
Tianning Yang ◽  
Zhengxiang He
Keyword(s):  
Family Member ◽  
Colony Formation ◽  
Epithelial Mesenchymal Transition ◽  
Colony Formation Assay ◽  
Transwell Assay ◽  
Mesenchymal Transition ◽  
Downstream Target

BackgroundThe involvement of microRNA-338-5p in modulating NPC pathogenesis is still largely unknown, and this study aimed to investigate this issue.MethodsThe expressions of cancer associated genes were determined by Real-Time qPCR and Western Blot, and cell apoptosis was determined by flow cytometer (FCM). CCK-8 assay and colony formation assay were respectively used to determine cell proliferation and colony formation abilities. Transwell assay was used to evaluate cell migration. The expression levels of Ki67 protein in mice tissues were measured by Immunohistochemistry (IHC) assay.ResultsThe present study found that microRNA-338-5p suppressed NPC progression by degrading its downstream target, Wnt family member 2B (WNT2B). Specifically, microRNA-338-5p tended to be low-expressed in NPC tissues and cell lines, compared to the non-tumor nasopharyngeal mucosa tissues and normal nasopharyngeal cell line (NP69). Upregulation of microRNA-338-5p inhibited proliferation, mobility, and epithelial-mesenchymal transition (EMT) in NPC cells in vitro, while silencing of microRNA-338-5p had opposite effects. Consistently, microRNA-338-5p suppressed tumorigenesis of NPC cells in vivo. In addition, microRNA-338-5p targeted WNT2B for degradation and inhibition, and the inhibiting effects of microRNA-338-5p overexpression on NPC development were reversed by upregulating WNT2B.ConclusionsTaken together, we concluded that microRNA-338-5p targeted WNT2B to hinder NPC development.

scholarly journals A possible role of plasma glutathione in glucose-mediated insulin secretion: in vitro and in vivo studies in rats

Diabetologia ◽  
1989 ◽  
Vol 32 (11) ◽  
Author(s):  
H.P.T. Ammon ◽  
S. Klumpp ◽  
A. Fu� ◽  
E.J. Verspohl ◽  
H. Jaeschke ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
In Vivo Studies ◽  
Plasma Glutathione ◽  
Insulin Secretion In Vitro

scholarly journals Progranulin attenuates liver fibrosis by downregulating the inflammatory response

2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Wonbeak Yoo ◽  
Jaemin Lee ◽  
Kyung Hee Noh ◽  
Sangmin Lee ◽  
Dana Jung ◽  
...  
Keyword(s):  
Liver Disease ◽  
Liver Fibrosis ◽  
Cell Activation ◽  
Stellate Cell ◽  
Raw 264.7 Cells ◽  
Protective Effects ◽  
Deficient Diet ◽  
A Cell

Abstract Progranulin (PGRN) is a cysteine-rich secreted protein expressed in endothelial cells, immune cells, neurons, and adipocytes. It was first identified for its growth factor-like properties, being implicated in tissue remodeling, development, inflammation, and protein homeostasis. However, these findings are controversial, and the role of PGRN in liver disease remains unknown. In the current study, we examined the effect of PGRN in two different models of chronic liver disease, methionine‐choline‐deficient diet (MCD)-induced non-alcoholic steatohepatitis (NASH) and carbon tetrachloride (CCl4)-induced liver fibrosis. To induce long-term expression of PGRN, PGRN-expressing adenovirus was delivered via injection into the tibialis anterior. In the CCl4-induced fibrosis model, PGRN showed protective effects against hepatic injury, inflammation, and fibrosis via inhibition of nuclear transcription factor kappa B (NF-κB) phosphorylation. PGRN also decreased lipid accumulation and inhibited pro-inflammatory cytokine production and fibrosis in the MCD-induced NASH model. In vitro treatment of primary macrophages and Raw 264.7 cells with conditioned media from hepatocytes pre-treated with PGRN prior to stimulation with tumor necrosis factor (TNF)-α or palmitate decreased their expression of pro-inflammatory genes. Furthermore, PGRN suppressed inflammatory and fibrotic gene expression in a cell culture model of hepatocyte injury and primary stellate cell activation. These observations increase our understanding of the role of PGRN in liver injury and suggest PGRN delivery as a potential therapeutic strategy in chronic inflammatory liver disease.

scholarly journals Loss-of-Function Mutation of the Galanin Gene Is Associated with Perturbed Islet Function in Mice

Endocrinology ◽  
2004 ◽  
Vol 145 (7) ◽  
pp. 3190-3196 ◽  
Author(s):  
Bo Ahrén ◽  
Giovanni Pacini ◽  
David Wynick ◽  
Nils Wierup ◽  
Frank Sundler
Keyword(s):  
Insulin Secretion ◽  
Islet Cells ◽  
Insulin Response ◽  
Tolerance Test ◽  
Glucose Disposal ◽  
Islet Function ◽  
Loss Of Function ◽  
Euglycemic Hyperinsulinemic Clamp

Abstract The neuropeptide galanin is expressed in sympathetic nerve terminals that surround islet cells and inhibits insulin secretion. To explore its role for islet function, we studied mice with a loss-of-function mutation in the galanin gene [galanin knockout (KO) mice]. Intravenous 2-deoxy-glucose, which activates both the sympathetic and parasympathetic branches of the autonomic nervous system, caused an initial (1–5 min) inhibition of insulin secretion that was impaired in galanin KO mice (P = 0.027), followed by a subsequent stimulation of insulin secretion that was augmented in galanin KO mice (P < 0.01). Similar effects were seen after chemical sympathectomy by 6-hydroxydopamine. In contrast, galanin KO mice had a reduced insulin response to glucose, both in vivo (P < 0.001) and in isolated islets (P < 0.001), and to arginine, both in vivo (P = 0.012) and in vitro (P = 0.018). During an iv glucose tolerance test, galanin KO mice had impaired glucose disposal (P = 0.005) due to a reduced insulin response (P < 0.001) and a reduced insulin-independent glucose elimination (glucose effectiveness; P = 0.040). Insulin sensitivity, as judged by a euglycemic, hyperinsulinemic clamp technique, was slightly increased in galanin KO mice (P = 0.032). We conclude that 1) galanin may contribute to sympathetic influences inhibiting insulin secretion in mice, and 2) galanin KO mice have a reduced glucose-induced insulin secretion.

Congenital Duplication of the Palm in a Patient with Multiple Anomalies

2003 ◽  
Vol 28 (3) ◽  
pp. 276-279 ◽  
Author(s):  
M. M. AL-QATTAN
Keyword(s):  
Family Member ◽  
Integration Site ◽  
Mammary Tumour ◽  
Mouse Mammary Tumour Virus ◽  
Virus Integration ◽  
Virus Integration Site

In 1995, Parr and McMahon described a syndrome of congenital duplication of footpads in mice which lacked a protein called ‘Wingless-type mouse mammary tumour virus integration site family member 7a” (Wnt-7a). This syndrome has not been described in humans and the following report describes a similar syndrome in a Saudi girl. The role of Wnt-7a in the development of the limb along the dorso-ventral axis is discussed, along with interaction between the Wnt-7a and other axes of limb growth.

Transgenic overexpression of intraislet ghrelin does not affect insulin secretion or glucose metabolism in vivo

2012 ◽  
Vol 302 (4) ◽  
pp. E403-E408 ◽  
Author(s):  
Mika Bando ◽  
Hiroshi Iwakura ◽  
Hiroyuki Ariyasu ◽  
Hiroshi Hosoda ◽  
Go Yamada ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Glucose Metabolism ◽  
Medium Chain Triglyceride ◽  
Physiological Role ◽  
Standard Diet ◽  
Entry Site ◽  
Insulin Secretion In Vivo

Whereas ghrelin is produced primarily in the stomach, a small amount of it is produced in pancreatic islets. Although exogenous administration of ghrelin suppresses insulin secretion in vitro or in vivo, the role of intraislet ghrelin in the regulation of insulin secretion in vivo remains unclear. To understand the physiological role of intraislet ghrelin in insulin secretion and glucose metabolism, we developed a transgenic (Tg) mouse model, rat insulin II promoter ghrelin-internal ribosomal entry site-ghrelin O-acyl transferase (RIP-GG) Tg mice, in which mouse ghrelin cDNA and ghrelin O-acyltransferase are overexpressed under the control of the rat insulin II promoter. Although pancreatic desacyl ghrelin levels were elevated in RIP-GG Tg mice, pancreatic ghrelin levels were not altered in animals on a standard diet. However, when Tg mice were fed a medium-chain triglyceride-rich diet (MCTD), pancreatic ghrelin levels were elevated to ∼16 times that seen in control animals. It seems likely that the gastric ghrelin cells possess specific machinery to provide the octanoyl acid necessary for ghrelin acylation but that this machinery is absent from pancreatic β-cells. Despite the overexpression of ghrelin, plasma ghrelin levels in the portal veins of RIP-GG Tg mice were unchanged from control levels. Glucose tolerance, insulin secretion, and islet architecture in RIP-GG Tg mice were not significantly different even when the mice were fed a MCTD. These results indicate that intraislet ghrelin does not play a major role in the regulation of insulin secretion in vivo.

Sign in / Sign up

Export Citation Format

Share Document