scholarly journals Human islet preparations distributed for research exhibit a variety of insulin-secretory profiles

2015 ◽  
Vol 308 (7) ◽  
pp. E592-E602 ◽  
Author(s):  
Nora S. Kayton ◽  
Gregory Poffenberger ◽  
Joseph Henske ◽  
Chunhua Dai ◽  
Courtney Thompson ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Human Islets ◽  
Glucose Sensing ◽  
Human Islet ◽  
Altered Expression ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Basal Insulin Secretion ◽  
The Many

Human islet research is providing new insights into human islet biology and diabetes, using islets isolated at multiple US centers from donors with varying characteristics. This creates challenges for understanding, interpreting, and integrating research findings from the many laboratories that use these islets. In what is, to our knowledge, the first standardized assessment of human islet preparations from multiple isolation centers, we measured insulin secretion from 202 preparations isolated at 15 centers over 11 years and noted five distinct patterns of insulin secretion. Approximately three quarters were appropriately responsive to stimuli, but one quarter were dysfunctional, with unstable basal insulin secretion and/or an impairment in stimulated insulin secretion. Importantly, the patterns of insulin secretion by responsive human islet preparations (stable Baseline and Fold stimulation of insulin secretion) isolated at different centers were similar and improved slightly over the years studied. When all preparations studied were considered, basal and stimulated insulin secretion did not correlate with isolation center, biological differences of the islet donor, or differences in isolation, such as Cold Ischemia Time. Dysfunctional islet preparations could not be predicted from the information provided by the isolation center and had altered expression of genes encoding components of the glucose-sensing pathway, but not of insulin production or cell death. These results indicate that insulin secretion by most preparations from multiple centers is similar but that in vitro responsiveness of human islets cannot be predicted, necessitating preexperimental human islet assessment. These results should be considered when one is designing, interpreting, and integrating experiments using human islets.

scholarly journals ERK1/2 mediates glucose-regulated POMC gene expression in hypothalamic neurons

2015 ◽  
Vol 54 (2) ◽  
pp. 125-135 ◽  
Author(s):  
Juan Zhang ◽  
Yunting Zhou ◽  
Cheng Chen ◽  
Feiyuan Yu ◽  
Yun Wang ◽  
...  
Keyword(s):  
Specific Inhibitor ◽  
Neuronal Cell ◽  
Glucose Sensing ◽  
Hypothalamic Neurons ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Low Glucose ◽  
Amp Activated Protein Kinase

Hypothalamic glucose-sensing neurons regulate the expression of genes encoding feeding-related neuropetides POMC, AgRP, and NPY – the key components governing metabolic homeostasis. AMP-activated protein kinase (AMPK) is postulated to be the molecular mediator relaying glucose signals to regulate the expression of these neuropeptides. Whether other signaling mediator(s) plays a role is not clear. In this study, we investigated the role of ERK1/2 using primary hypothalamic neurons as the model system. The primary neurons were differentiated from hypothalamic progenitor cells. The differentiated neurons possessed the characteristic neuronal cell morphology and expressed neuronal post-mitotic markers as well as leptin-regulated orexigenic POMC and anorexigenic AgRP/NPY genes. Treatment of cells with glucose dose-dependently increased POMC and decreased AgRP/NPY expression with a concurrent suppression of AMPK phosphorylation. In addition, glucose treatment dose-dependently increased the ERK1/2 phosphorylation. Blockade of ERK1/2 activity with its specific inhibitor PD98059 partially (approximately 50%) abolished glucose-induced POMC expression, but had little effect on AgRP/NPY expression. Conversely, blockade of AMPK activity with its specific inhibitor produced a partial (approximately 50%) reversion of low-glucose-suppressed POMC expression, but almost completely blunted the low-glucose-induced AgRP/NPY expression. The results indicate that ERK1/2 mediated POMC but not AgRP/NPY expression. Confirming the in vitro findings, i.c.v. administration of PD98059 in rats similarly attenuated glucose-induced POMC expression in the hypothalamus, but again had little effect on AgRP/NPY expression. The results are indicative of a novel role of ERK1/2 in glucose-regulated POMC expression and offer new mechanistic insights into hypothalamic glucose sensing.

scholarly journals In vivo transcriptome analysis provides insights into host-dependent expression of virulence factors by Yersinia entomophaga MH96, during infection of Galleria mellonella

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Amber R Paulson ◽  
Maureen O’Callaghan ◽  
Xue-Xian Zhang ◽  
Paul B Rainey ◽  
Mark R H Hurst
Keyword(s):  
Galleria Mellonella ◽  
Functional Enrichment ◽  
Natural Environments ◽  
Insecticidal Toxin ◽  
Heat Stable ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Cell Densities

Abstract The function of microbes can be inferred from knowledge of genes specifically expressed in natural environments. Here, we report the in vivo transcriptome of the entomopathogenic bacterium Yersinia entomophaga MH96, captured during initial, septicemic, and pre-cadaveric stages of intrahemocoelic infection in Galleria mellonella. A total of 1285 genes were significantly upregulated by MH96 during infection; 829 genes responded to in vivo conditions during at least one stage of infection, 289 responded during two stages of infection, and 167 transcripts responded throughout all three stages of infection compared to in vitro conditions at equivalent cell densities. Genes upregulated during the earliest infection stage included components of the insecticidal toxin complex Yen-TC (chi1, chi2, and yenC1), genes for rearrangement hotspot element containing protein yenC3, cytolethal distending toxin cdtAB, and vegetative insecticidal toxin vip2. Genes more highly expressed throughout the infection cycle included the putative heat-stable enterotoxin yenT and three adhesins (usher-chaperone fimbria, filamentous hemagglutinin, and an AidA-like secreted adhesin). Clustering and functional enrichment of gene expression data also revealed expression of genes encoding type III and VI secretion system-associated effectors. Together these data provide insight into the pathobiology of MH96 and serve as an important resource supporting efforts to identify novel insecticidal agents.

scholarly journals The Genes Encoding Small Leucine-Rich Proteoglycans Undergo Differential Expression Alterations in Colorectal Cancer, Depending on Tumor Location

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 2002
Author(s):  
Maria Pilar Solis-Hernandez ◽  
Carla Martín ◽  
Beatriz García ◽  
Natalia Pérez-López ◽  
Yolanda García-Mesa ◽  
...  
Keyword(s):  
Protein Expression ◽  
Survival Data ◽  
Tumor Cell Line ◽  
Tumor Location ◽  
Anatomical Location ◽  
Cell Interior ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
Descending Colon

Small leucine-rich proteoglycans (SLRPs) regulate different processes and undergo significant alterations in various diseases. Colon carcinomas (CCs) are heterogeneous pathologies with important clinical and molecular differences depending on their location, which makes it interesting to analyze the alterations in SLRPs in right- and left-sided tumors (RS- and LSCCs). SLRP transcription levels were studied in 32 CCs using qPCR compared to healthy colon mucosae samples from the same patients, 20 of them from LSCCs and the remaining 12 from RSCCs. Protein expression of genes with significant differences in their transcriptions was analyzed by immunohistochemistry. The alterations observed were related to survival data. The arrangement of transcription of SLRPs was quite similar in ascending and descending colon, but RS- and LSCCs displayed different patterns of alteration, with a greater number of deregulations occurring in the latter. The analysis of protein expression also indicated changes in the location of these molecules, largely moving to the cell interior. While podocan underexpression showed a trend toward better outcomes, no differences were observed in terms of overall survival. In vitro studies using the HT29 tumor cell line suggest that deregulation of SLRPs could affect cell proliferation. SLRPs constitute new differential markers of RS- and LSCCs, showing differences dependent on the anatomical location of the tumor.

scholarly journals Effect of adalimumab on the expression of genes encoding TNF-α signal paths in skin fibroblasts in vitro

2018 ◽  
Vol 35 (4) ◽  
pp. 413-422 ◽  
Author(s):  
Dominika Wcisło-Dziadecka ◽  
Joanna Gola ◽  
Beniamin Grabarek ◽  
Urszula Mazurek ◽  
Ligia Brzezińska-Wcisło ◽  
...  
Keyword(s):  
Skin Fibroblasts ◽  
Expression Of Genes ◽  
Tnf Α ◽  
Genes Encoding

scholarly journals Age-dependent changes in electrophysiology and calcium handling – implications for pediatric cardiac research

2019 ◽  
Author(s):  
Luther M. Swift ◽  
Morgan Burke ◽  
Devon Guerrelli ◽  
Manelle Ramadan ◽  
Marissa Reilly ◽  
...  
Keyword(s):  
Postnatal Development ◽  
Cardiac Electrophysiology ◽  
Calcium Handling ◽  
Cell Coupling ◽  
Altered Expression ◽  
Expression Of Genes ◽  
Age Dependent ◽  
Genes Encoding ◽  
Cardiac Maturation

ABSTRACTRationaleThe heart continues to develop and mature after birth and into adolescence. Accordingly, cardiac maturation is likely to include a progressive refinement in both organ morphology and function during the postnatal period. Yet, age-dependent changes in cardiac electrophysiology and calcium handling have not yet been fully characterized.ObjectiveThe objective of this study, was to examine the relationship between cardiac maturation, electrophysiology, and calcium handling throughout postnatal development in a rat model.MethodsPostnatal rat cardiac maturation was determined by measuring the expression of genes involved in cell-cell coupling, electrophysiology, and calcium handling. In vivo electrocardiograms were recorded from neonatal, juvenile, and adult animals. Simultaneous dual optical mapping of transmembrane voltage and calcium transients was performed on isolated, Langendorff-perfused rat hearts (postnatal day 0–3, 4-7, 8-14, adult).ResultsYounger, immature hearts displayed slowed electrical conduction, prolonged action potential duration and increased ventricular refractoriness. Slowed calcium handling in the immature heart increased the propensity for calcium transient alternans which corresponded to alterations in the expression of genes encoding calcium handling proteins. Developmental changes in cardiac electrophysiology were associated with the altered expression of genes encoding potassium channels and intercalated disc proteins.ConclusionUsing an intact whole heart model, this study highlights chronological changes in cardiac electrophysiology and calcium handling throughout postnatal development. Results of this study can serve as a comprehensive baseline for future studies focused on pediatric cardiac research, safety assessment and/or preclinical testing using rodent models.

scholarly journals Strain-specific differences in age-related changes in rat susceptibility to experimental autoimmune encephalomyelitis and dendritic cell cytokine gene expression

Genetika ◽  
2014 ◽  
Vol 46 (1) ◽  
pp. 287-301 ◽  
Author(s):  
Biljana Bufan ◽  
Jasmina Djikic ◽  
Mirjana Nacka-Aleksic ◽  
Zorica Stojic-Vukanic ◽  
Mirjana Dimitrijevic ◽  
...  
Keyword(s):  
Dendritic Cell ◽  
Rt Pcr ◽  
Autoimmune Encephalomyelitis ◽  
Expression Of Genes ◽  
Age Related ◽  
Genes Encoding ◽  
Immunosuppressive Cytokines ◽  
Age Related Changes ◽  
Experimental Autoimmune

Experimental autoimmune encephalomyelitis (EAE) is an animal model of multiple sclerosis, a prototype of Th1/Th17-mediated organ-specific autoimmune disease. In the rat, susceptibility to development of these diseases is shown to be strain-and age-dependent. In adult rats of distinct strains, it correlates with splenic dendritic cell (DC) subset composition, which also exhibit age-related changes. The aim of this study was to examine influence of aging on: i) Albino Oxford (relatively resistant to EAE) and Dark Agouti (susceptible to EAE) rat development of EAE and ii) their splenic conventional (OX62+) DC population in respect to its subset composition and expression of mRNAs for proinflammatory and immunosuppressive cytokines. We used 3month-old (young) and 26-month-old (aged) rats of AO and DA strain. The rats were immunized for EAE with rat spinal cord homogenate in complete Freund?s adjuvant and clinical course of the disease was followed. Fresh OX62+DCs were examined for the expression of CD4 (using flow cytometry) and genes encoding cytokines influencing DC activation/maturation (TNF-? and IL-6) using RT-PCR. Additionally, in vitro lipopolysaccharide (LPS) activated/matured DCs were examined for the expression of genes encoding cytokines controlling Th1/Th17 cell polarization using RT-PCR. With aging, AO rats became more susceptible, whereas DA rats largely lose their susceptibility to the induction of EAE. In AO rats aging shifted CD4+:CD4DC ratio towards CD4-cells, producing large amount of proinflammatory cytokines, whereas in DA rats CD4+:CD4-DC ratio remained stable with aging. In fresh DCs from rats of both the strains the expression of TNF-? mRNA increased with aging, whereas that of IL-6 mRNA decreased and increased in DCs from AO and DA rats, respectively. Following in vitro LPS stimulation OX62+ DCs from aged AO rats up-regulated the expression of mRNA for IL-23p19 (specific subunit of IL-23; crucial for sustained IL-17 production) and IL-1? (positive IL-17 regulator), whereas down-regulated the expression of IL-10 (negative IL-17 regulator) when compared with young strain-matched rats. In DA rats aging incresed IL-23p19 mRNA expression in LPS-stimulated DCs, whereas exerted the opposing effects on the expression of mRNAs for IL-10 and IL-1? compared to AO rats. Irrespective of the rat strain, aging did not influence mRNA expression for IL-12p35 (driving Th1 polarization) in DCs. Overall, results suggest role of changes in the expression of genes encoding proinflammatory and immunosuppressive cytokines in development of age-related alterations in rat susceptibility to EAE induction.

scholarly journals Cyclophilin a as a Mediator of Tissue Injure and Nephrotoxicity

2012 ◽  
Vol 4 (2) ◽  
pp. 42-44
Author(s):  
Grace Moscoso-Solorzano ◽  
Gianna Mastroianni-Kirsztajn
Keyword(s):  
Molecular Mechanisms ◽  
Tissue Injury ◽  
Cyclophilin A ◽  
Common Mechanism ◽  
Ppiase Activity ◽  
Expression Of Genes ◽  
Inflammatory Stimuli ◽  
Genes Encoding ◽  
Inflammatory Processes

Cyclophilin A (CypA) belongs to the peptidyl-prolil isomerase (PPlase) family of proteins and it is also known as the cellular receptor for cyclosporine A (CsA). CsA binds to CypA and inhibits the PPIase activity, but the CypA-CsA complex also binds to calcineurin that promotes the expression of genes encoding cytokines and other proteins required for immune response. In addition, the polymorphism variation of CypA promoter seems to have an influence on the expression of CypA in in vitro studies. CypA was also implicated in inflammatory processes (such as, among others, those observed in rheumatoid arthritis, atherosclerotic disease, nephrotoxicity) and it can be secreted by cells in response to inflammatory stimuli. CypA can also have a role in the molecular mechanisms by which CsA induces nephroxicity but these remain poorly understood. Recent studies suggest that CsA inhibition of CypA PPlase activity is a possible mechanism of this drug toxicity. In addition, CypA overexpression could be protective against CsA nephrotoxicity. Finally, the putative common mechanism by which CypA could be involved in CsA nephrotoxicity and tissue injury is related to its proinflammatory effects in cells.

scholarly journals Proteomic Profiling Reveals the Ambivalent Character of the Mesenchymal Stem Cell Secretome: Assessing the Effect of Preconditioned Media on Isolated Human Islets

2020 ◽  
Vol 29 ◽  
pp. 096368972095233
Author(s):  
Heide Brandhorst ◽  
Daniel Brandhorst ◽  
Anju Abraham ◽  
Samuel Acreman ◽  
Simen W. Schive ◽  
...  
Keyword(s):  
Culture Media ◽  
Human Islets ◽  
Human Islet ◽  
Physical Contact ◽  
Proteomic Profiling ◽  
Protective Capacity ◽  
Islet Culture ◽  
Proinflammatory Mediators ◽  
Related Proteins

Previous studies in rodents have indicated that function and survival of transplanted islets can be substantially improved by mesenchymal stem cells (MSC). The few human islet studies to date have confirmed these findings but have not determined whether physical contact between MSC and islets is required or whether the benefit to islets results from MSC-secreted proteins. This study aimed to investigate the protective capacity of MSC-preconditioned media for human islets. MSC were cultured for 2 or 5 days in normoxia or hypoxia before harvesting the cell-depleted media for human islet culture in normoxia or hypoxia for 6–8 or 3–4 days, respectively. To characterize MSC-preconditioned media, proteomic secretome profiling was performed to identify angiogenesis- and inflammation-related proteins. A protective effect of MSC-preconditioned media on survival and in vitro function of hypoxic human islets was observed irrespective of the atmosphere used for MSC preconditioning. Islet morphology changed markedly when media from hypoxic MSC were used for culture. However, PDX-1 and insulin gene expression did not confirm a change in the genetic phenotype of these islets. Proteomic profiling of preconditioned media revealed the heterogenicity of the secretome comprising angiogenic and antiapoptotic as well as angiostatic or proinflammatory mediators released at an identical pattern regardless whether MSC had been cultured in normoxic or hypoxic atmosphere. These findings do not allow a clear discrimination between normoxia and hypoxia as stimulus for protective MSC capabilities but indicate an ambivalent character of the MSC angiogenesis- and inflammation-related secretome. Nevertheless, culture of human islets in acellular MSC-preconditioned media resulted in improved morphological and functional islet integrity suggesting a disbalance in favor of protective factors. Further approaches should aim to eliminate potentially detrimental factors to enable the production of advanced clinical grade islet culture media with higher protective qualities.

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