| 1. |
- Barbu, Andreea, et al.
(författare)
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Progranulin Stimulates Proliferation of Mouse Pancreatic Islet Cells and Is Overexpressed in the Endocrine Pancreatic Tissue of an MEN1 Mouse Model
- 2016
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Ingår i: Pancreas. - 0885-3177 .- 1536-4828. ; 45:4, s. 533-540
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Progranulin (PGRN) promotes cell growth and cell cycle progression in several cell types and contributes to tumorigenesis in diverse cancers. We have recently reported PGRN expression in islets and tumors developed in an MEN1 transgenic mouse. Here we sought to investigate PGRN expression and regulation after exposure to hypoxia as well as its effects on pancreatic islet cells and neuroendocrine tumors (NETs) in MEN1 mice.METHODS: Gene and protein expression were analyzed by quantitative polymerase chain reaction, immunohistochemistry, and Western blot. We also investigated PGRN expression in samples from patients carrying pancreatic NETs associated or not with the multiple endocrine neoplasia 1 syndrome, using enzyme-linked immunosorbent assay and immunohistochemistry analysis.RESULTS: Progranulin is upregulated in tumors and islets of the MEN1 mouse as well as in the serum of patients with pancreatic NETs associated with glucagonoma syndrome. In normal mice islets and pancreatic tumors, PGRN expression was strongly potentiated by hypoxia. Progranulin promotes cell proliferation in islet cells and βTC-6 cells, a process paralleled by activation of the mitogen-activated protein kinase signaling cascade.CONCLUSIONS: Our findings identify PGRN as an effective inducer of pancreatic islet cell proliferation and a possible important factor for pancreatic endocrine tumor development.
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| 2. |
- Klint, Helén, et al.
(författare)
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Low-dose exposure to bisphenol A in combination with fructose increases expression of genes regulating angiogenesis and vascular tone in juvenile Fischer 344 rat cardiac tissue
- 2017
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 122:1, s. 20-27
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Epidemiological studies report associations between exposure to the high-volume chemical and endocrine disruptor bisphenol A (BPA) and cardiovascular disorders, but there is a lack of experimental studies addressing the mechanisms of action of BPA on the cardiovascular system. In the present study, effects on markers for cardiovascular function of exposure to BPA and fructose in vivo in rat cardiac tissues, and of BPA exposure in human cardiomyocytes in vitro, were investigated.MATERIALS: Juvenile female Fischer 344 rats were exposed to 5, 50, and 500 μg BPA/kg bodyweight/day in their drinking water from 5 to 15 weeks of age, in combination with 5% fructose. Further, cultured human cardiomyocytes were exposed to 10 nM BPA to 1 × 10(4) nM BPA for six hours. Expression of markers for cardiovascular function and BPA target receptors was investigated using qRT-PCR.RESULTS: Exposure to 5 μg BPA/kg bodyweight/day plus fructose increased mRNA expression of Vegf, Vegfr2, eNos, and Ace1 in rat heart. Exposure of human cardiomyocytes to 1 × 10(4) nM BPA increased mRNA expression of eNOS and ACE1, as well as IL-8 and NFκβ known to regulate inflammatory response.CONCLUSIONS: . Low-dose exposure of juvenile rats to BPA and fructose induced up-regulation of expression of genes controlling angiogenesis and vascular tone in cardiac tissues. The observed effects of BPA in rat heart were in line with our present and previous studies of BPA in human endothelial cells and cardiomyocytes. These findings may aid in understanding the mechanisms of the association between BPA exposure and cardiovascular disorders reported in epidemiological studies.
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| 3. |
- Lejonklou, Margareta H, et al.
(författare)
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Accelerated Proliferation and Differential Global Gene Expression in Pancreatic Islets of Five-Week-Old Heterozygous Men1 Mice : Men1 Is a Haploinsufficient Suppressor
- 2012
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 153:6, s. 2588-2598
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Tidskriftsartikel (refereegranskat)abstract
- Individuals carrying heterozygous (hz) MEN1 (Multiple Endocrine Neoplasia Syndrome Type 1) germ line mutations develop endocrine tumors as a result of somatic loss of the wild-type (wt) allele. However, endocrine cell proliferation has been observed despite wt allele retention, indicating haploinsufficiency. To study downstream molecular effects of the hz haplotype, a germ line Men1 hz mouse model was used to explore differences in global endocrine pancreatic gene expression. Because islet cells of 5-wk-old hz mice express Menin from the retained wt Men1 allele, these were isolated after collagenase digestion of the pancreas, and used for global gene expression array. Wild-type littermates were used for comparison. Array findings were corroborated by quantitative PCR, Western blotting, in situ proximity ligation assay, and immunohistochemistry. The hz islets show increased proliferation: the Ki-67 index was twice as high as in wt islets (3.48 vs. 1.74%; P = 0.024). The microarray results demonstrated that several genes were differentially expressed. Some selected genes were studied on the protein level, e.g. the cytoskeletal regulator myristoylated alanine-rich protein kinase C substrate (Marcks) was significantly less expressed in hz islets, using in situ proximity ligation assay and Western blotting (P < 0.001 and P < 0.01, respectively). Further, gene ontology analysis showed that genes with higher mRNA expression in the hz endocrine pancreas were associated with e.g. chromatin maintenance and apoptosis. Lower mRNA was observed for genes involved in growth factor binding. In conclusion, despite retained Menin expression, proliferation was accelerated, and numerous genes were differentially expressed in the endocrine pancreas of 5-wk-old hz Men1 mice, corroborating the hypothesis that MEN1 is a haploinsufficient suppressor.
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| 4. |
- Lejonklou, Margareta H., et al.
(författare)
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Low-dose developmental exposure to bisphenol A alters the femoral bone geometry in wistar rats
- 2016
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 164, s. 339-346
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Tidskriftsartikel (refereegranskat)abstract
- Background: Bisphenol A (BPA) is a chemical produced in large volumes for use in manufacturing of consumer products and industrial applications, and an endocrine disruptor known to affect several hormonal systems. Bone produces hormones and is additionally a sensitive hormone target tissue, and is thus potentially sensitive to low doses of endocrine disruptors such as BPA, especially during development. Methods: 110 pregnant Wistar rats were gavaged with 0; 25 mu g; 250 mu g; 5000 mu g or 50,000 mu g BPA/kg bodyweight (bw)/day from gestational day 7 until weaning at postnatal day 22. The three-month-old offspring were sacrificed and right femurs collected for length measurements, geometrical measurements by peripheral quantitative computed tomography (pQCT), as well as for analyses of biomechanical properties using the three-point-bending method. Results: The femur was elongated in female offspring of dams exposed to 25 or 5000 mu g BPA/kg bw/day (1.8% and 2.1%, respectively), and increased cortical thickness (4.7%) was observed in male offspring of dams exposed to 25 mu g BPA/kg bw/day, compared to controls (p < 0.005). The biomechanical properties of the bone were not significantly altered. Conclusions: In utero and lactational exposure to the lowest BPA dose used in this study altered femoral geometry in both male and female offspring. This was observed at 25 mu g BPA/kg bw/day, a dose lower than the Human Equivalent Dose (HED) applied by EFSA to set a temporary TDI (609 mu g BPA/kg bw/day), and far lower than the No-Observed-Adverse-Effect-Level (NOAEL) (5000 mu g BPA/kg bw/day) on which the US FDA TDI is based.
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| 5. |
- Lind, Lars, et al.
(författare)
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Uppsala Consensus Statement on Environmental Contaminants and the Global Obesity Epidemic
- 2016
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Ingår i: Journal of Environmental Health Perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 124:5, s. A81-A83
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Tidskriftsartikel (refereegranskat)abstract
- From the lectures presented at the 2nd International Workshop on Obesity and Environmental Contaminants, which was held in Uppsala, Sweden, on 8–9 October 2015, it became evident that the findings from numerous animal and epidemiological studies are consistent with the hypothesis that environmental contaminants could contribute to the global obesity epidemic. To increase awareness of this important issue among scientists, regulatory agencies, politicians, chemical industry management, and the general public, the authors summarize compelling scientific evidence that supports the hypothesis and discuss actions that could restrict the possible harmful effects of environmental contaminants on obesity.
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