| 41. |
- Russell, Floyd A., et al.
(författare)
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Stemodin-derived analogues with lipid peroxidation, cyclooxygenase enzymes and human tumour cell proliferation inhibitory activities
- 2011
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Ingår i: Phytochemistry. - : Elsevier BV. - 0031-9422. ; 72:18, s. 2361-2368
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Tidskriftsartikel (refereegranskat)abstract
- A series of analogues, derived from the antiviral and cytotoxic diterpene stemodin, were prepared and evaluated for their lipid peroxidation (LPO), cyclooxygenase enzyme-1 (COX-1) and -2 (COX-2), and tumour cell proliferation inhibitory activities. Oxidation of stemodin produced stemodinone, which was then converted to stemod-12-en-2-one. Reaction of the latter under Petrow conditions (bromine; silver acetate/pyridine) yielded mainly dibrominated abeo-stachanes. Solvolysis of the dibromo compounds gave products of hydrolysis, some with rearranged skeleta. In the lipid peroxidation inhibitory assay three of the compounds exhibited prominent activity. Interestingly, all the analogues showed higher COX-1 enzyme inhibition than COX-2. Although a few of the diterpenes limited the growth of some human tumour cell lines, most compounds induced proliferation of such cells.
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| 42. |
- Chang, Yanhai, et al.
(författare)
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Inflammatory cytokine of IL-1β is involved in T-2 toxin-triggered chondrocyte injury and metabolism imbalance by the activation of Wnt/β-catenin signaling
- 2017
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Ingår i: Molecular Immunology. - : Elsevier. - 0161-5890 .- 1872-9142. ; 91, s. 195-201
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Tidskriftsartikel (refereegranskat)abstract
- Mycotoxin T-2 exerts a causative role in Kashin-Beck disease (KBD) suffering chondrocyte apoptosis and cartilage matrix homeostasis disruption. Recent research corroborated the aberrant levels of pro-inflammatory cytokine IL-1ß in KBD patients and mycotoxin environment. In the present study, we investigated the relevance of IL-1ß in T-2 toxin-evoked chondrocyte cytotoxic injury and aberrant catabolism. High levels of IL-1ß were detected in serum and cartilages from KBD patients and in T-2-stimulated chondrocytes. Moreover, knockdown of IL-1ß antagonized the adverse effects of T-2 on cytotoxic injury by enhancing cell viability and inhibiting apoptosis. However, exogenous supplementation of IL-1β further aggravated cell damage in response to T-2. Additionally, cessation of IL-1β rescued T-2-elicited tilt of matrix homeostasis toward catabolism by elevating the transcription of collagen II and aggrecan, promoting release of sulphated glycosaminoglycans (sGAG) and TIMP1, and suppressing matrix metalloproteinases production including MMP-1, MMP-3 and MMP-13. Conversely, IL-1β stimulation deteriorated T-2-induced disruption of matrix metabolism balance toward catabolism. Mechanistic analysis found the high activation of Wnt/β-catenin in KBD patients and chondrocytes upon T-2. Furthermore, this activation was mitigated after IL-1β inhibition, but further enhanced following IL-1β precondition. Importantly, blocking this pathway by transfection with β-catenin alleviated the adverse roles of IL-1β on cytotoxic injury and metabolism disorders under T-2 conditioning. Together, this study elucidates a new insight into how T-2 deteriorates the pathological progression of KBD by regulating inflammation-related pathways, indicating a promising anti-inflammation strategy for KBD therapy.
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| 43. |
- Widhe, Mona, et al.
(författare)
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Recombinant spider silk as matrices for cell culture
- 2010
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Ingår i: Biomaterials. - : Elsevier. - 0142-9612 .- 1878-5905. ; 31:36, s. 9575-85
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Tidskriftsartikel (refereegranskat)abstract
- The recombinant miniature spider silk protein, 4RepCT, was used to fabricate film, foam, fiber and mesh matrices of different dimensionality, microstructure and nanotopography. These matrices were evaluated regarding their suitability for cell culturing. Human primary fibroblasts attached to and grew well on all matrix types, also in the absence of serum proteins or other animal-derived additives. The highest cell counts were obtained on matrices combining film and fiber/mesh. The cells showed an elongated shape that followed the structure of the matrices and exhibited prominent actin filaments. Moreover, the fibroblasts produced, secreted and deposited collagen type I onto the matrices. These results, together with findings of the matrices being mechanically robust, hold promise not only for in vitro cell culturing, but also for tissue engineering applications.
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| 44. |
- Zhao, Guang-Hui, et al.
(författare)
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A preliminary analysis of microRNA profiles in the subchondral bone between Kashin-Beck disease and primary knee osteoarthritis
- 2019
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Ingår i: Clinical Rheumatology. - : Springer Science and Business Media LLC. - 0770-3198 .- 1434-9949. ; 38:9, s. 2637-2645
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Kashin-Beck disease (KBD) is a chronic osteochondral disorder primarily associated with cartilage degeneration. The bone texture structure in KBD was also changed but it was not identical to primary knee osteoarthritis (OA). This study investigates the differences in microRNA (miRNA) profiles of subchondral bone collected from patients suffering from KBD in comparison with those with primary knee osteoarthritis (OA).METHODS: Subchondral bone tissues were taken from four patients with KBD and four patients with primary knee OA undergoing total knee replacement. The miRNA array profiling was performed using an Affymetrix miRNA 4.0 Array, and then the target gene predictions and function annotations of the predicted targets were performed.RESULTS: Our results showed that 124 miRNAs had lower expression levels in the subchondral bone sampled from KBD patients in comparison with OA patients. Gene ontology (GO) and KEGG pathway analyses of the predicted targets demonstrated numerous significantly enriched GO terms and signal pathways essential for bone development and integrity, such as metabolic processes, PI3K-Akt, and MAPK signaling pathways.CONCLUSIONS: Our study confirms that a large set of miRNAs are differentially expressed in the subchondral bone of patients with KBD and OA and contributes new insights into potential pathological changes in the subchondral bone of KBD patients.
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| 45. |
- Nowak, Christoph, 1986-
(författare)
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Insulin Resistance : Causes, biomarkers and consequences
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The worldwide increasing number of persons affected by largely preventable diseases like diabetes demands better prevention and treatment. Insulin is required for effective utilisation of circulating nutrients. Impaired responsiveness to insulin (insulin resistance, IR) is a hallmark of type 2 diabetes and independently raises the risk of heart attack and stroke. The pathophysiology of IR is incompletely understood. High-throughput measurement of large numbers of circulating biomarkers may provide new insights beyond established risk factors.The aims of this thesis were to (i) use proteomics, metabolomics and genomics methods in large community samples to identify biomarkers of IR; (ii) assess biomarkers for risk prediction and insights into aetiology and consequences of IR; and (iii) use Mendelian randomisation analysis to assess causality.In Study I, analysis of 80 circulating proteins in 70-to-77-year-old Swedes identified cathepsin D as a biomarker for IR and highlighted a tentative causal effect of IR on raised plasma tissue plasminogen activator levels. In Study II, nontargeted fasting plasma metabolomics was used to discover 52 metabolites associated with glycaemic traits in non-diabetic 70-year-old men. Replication in independent samples of several thousand persons provided evidence for a causal effect of IR on reduced plasma oleic acid and palmitoleic acid levels. In Study III, nontargeted metabolomics in plasma samples obtained at three time points during an oral glucose challenge in 70-year-old men identified associations between a physiologic measure of IR and concentration changes in medium-chain acylcarnitines, monounsaturated fatty acids, bile acids and lysophosphatidylethanolamines. Study IV provided evidence in two large longitudinal cohorts for causal effects of type 2 diabetes and impaired insulin secretion on raised coronary artery disease risk.In conclusion, the Studies in this thesis provide new insights into the pathophysiology and adverse health consequences of IR and illustrate the value of combining traditional epidemiologic designs with recent molecular techniques and bioinformatics methods. The results provide limited evidence for the role of circulating proteins and small molecules in IR and require replication in separate studies and validation in experimental designs.
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| 46. |
- Dieterich, Lothar
(författare)
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Molecular Regulation of Inflammation and Angiogenesis in the Tumor Microenvironment
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Tumor growth and progression not only depend on properties of the malignant cells but are strongly influenced by the tumor microenvironment. The tumor stroma consists of various cell types such as inflammatory cells, endothelial cells and fibroblasts, which can either inhibit or promote tumor growth. Consequently, therapeutic targeting of the tumor stroma is increasingly recognized as an important tool to fight cancer. Two particularly important processes that contribute to the pathology of most types of tumors are angiogenesis and inflammation. In order to target these processes specifically and efficiently, it is fundamental to identify and understand the factors and signaling pathways involved. This thesis initially describes the multiple functions of the small heat shock protein αB-crystallin in the tumor microenvironment. αB-crystallin was first identified in a screen of proteins specifically up-regulated in endothelial cells forming vessel-like structures. We found that αB-crystallin is expressed in a subset of tumor vessels and promotes angiogenesis by inhibiting endothelial apoptosis, suggesting that targeting of αB-crystallin might inhibit angiogenesis and thereby decrease tumor growth. However, we also discovered an important role of αB-crystallin in regulation of inflammatory processes. We show that αB-crystallin increases the surface levels of E-selectin, an important leukocyte-endothelial adhesion molecule. Thereby, αB-crystallin may alter leukocyte recruitment to inflamed tissues such as the tumor stroma. In addition, we found that αB-crystallin is expressed in immature myeloid cells that accumulate in the periphery and at the tumor site during tumor development. Importantly, lack of αB-crystallin resulted in increased accumulation of immature myeloid cells, which might increase tumor associated inflammation. Finally, through combining laser microdissection of vessels from human tissue and microarray analysis, we identified a gene expression signature specifically associated with vessels in high grade glioma. Blood vessels in malignant glioma are highly abnormal and contribute to the pathology of the disease. Thus, knowledge about the molecular set-up of these vessels might contribute to the development of future vascular normalizing treatments.
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| 47. |
- Nilsson, Daniel, 1975, et al.
(författare)
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Foxc2 is essential for podocyte function.
- 2019
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Ingår i: Physiological reports. - : Wiley. - 2051-817X. ; 7:9
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Tidskriftsartikel (refereegranskat)abstract
- Foxc2 is one of the earliest podocyte markers during glomerular development. To circumvent embryonic lethal effects of global deletion of Foxc2, and to specifically investigate the role of Foxc2 in podocytes, we generated mice with a podocyte-specific Foxc2 deletion. Mice carrying the homozygous deletion developed early proteinuria which progressed rapidly into end stage kidney failure and death around postnatal day 10. Conditional loss of Foxc2 in podocytes caused typical characteristics of podocyte injury, such as podocyte foot process effacement and podocyte microvillus transformation, probably caused by disruption of the slit diaphragm. These effects were accompanied by a redistribution of several proteins known to be necessary for correct podocyte structure. One target gene that showed reduced glomerular expression was Nrp1, the gene encoding neuropilin 1, a protein that has been linked to diabetic nephropathy and proteinuria. We could show that NRP1 was regulated by Foxc2 invitro, but podocyte-specific ablation of Nrp1 in mice did not generate any phenotype in terms of proteinuria, suggesting that the gene might have more important roles in endothelial cells than in podocytes. Taken together, this study highlights a critical role for Foxc2 as an important gene for podocyte function.
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| 48. |
- Gillman, Anna, et al.
(författare)
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Oseltamivir-Resistant Influenza A (H1N1) Virus Strain with an H274Y Mutation in Neuraminidase Persists without Drug Pressure in Infected Mallards
- 2015
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Ingår i: Applied and Environmental Microbiology. - : American Society for Microbiology. - 0099-2240 .- 1098-5336. ; 81:7, s. 2378-2383
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Tidskriftsartikel (refereegranskat)abstract
- Influenza A virus (IAV) has its natural reservoir in wild waterfowl and emerging human IAVs often contain gene segments from avian viruses. The active drug metabolite of oseltamivir (oseltamivir carboxylate (OC)), stockpiled as Tamiflu® for influenza pandemic preparedness, is not removed by conventional sewage treatment and has been detected in river water. There, it may there exert evolutionary pressure on avian IAV in waterfowl, resulting in development of resistant viral variants. A resistant avian IAV can circulate among wild birds only if resistance does not restrict viral fitness and if the resistant virus can persist without continuous drug pressure. In this in vivo Mallard (Anas platyrhynchos) study we tested if an OC-resistant avian IAV strain (A(H1N1)/NA-H274Y) could retain resistance while drug pressure was gradually removed. Successively infected Mallards were exposed to decreasing levels of OC, and fecal samples were analyzed for neuraminidase sequence and phenotypic resistance. No reversion to wild-type virus was observed during the experiment, which included 17 days of viral transmission in 10 ducks exposed to OC concentrations below resistance induction levels. We conclude that resistance in avian IAV, induced by OC exposure of the natural host, can persist in absence of the drug. Thus, there is a risk that human pathogenic IAVs that evolve from IAVs circulating among wild birds may contain resistance mutations. An oseltamivir resistant pandemic IAV would be a substantial public health threat. Therefore, our observations underscore the need for prudent oseltamivir use, upgraded sewage treatment and resistance surveillance of IAV in wild birds.
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| 49. |
- Heyman, Lovisa
(författare)
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Berries in Prevention of Metabolic Disease – focus on obesity, diabetes and gut microbiota
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The increasing prevalence of obesity is a worldwide health problem closely linked to diet and lifestyle factors. Obesity is associated with increased risk of several metabolic disorders including insulin resistance, nonalcoholic fatty liver disease and type 2 diabetes. Hence, there is a great need to identify dietary strategies for the prevention of obesity and related diseases. This thesis investigates the potential of different berries to mediate beneficial health effects in a mouse model of diet-induced obesity and prediabetes. We found that supplementation with lingonberries, blackcurrants and bilberries reduced body weight gain, insulin resistance, low-grade inflammation and hepatic lipid accumulation in C57BL/6J mice fed a high-fat diet. Supplementation with raspberries, crowberries, blackberries or prunes had no or small effects, whereas açai berries promoted development of obesity and fatty liver compared to the control group receiving high-fat diet without berries. Global hepatic gene expression analysis revealed that the phenotype in the lingonberry and bilberry groups was coupled to an anti-inflammatory effect, including downregulation of acute-phase proteins and inflammatory mediators. Mice receiving açai displayed an upregulation of steatosis markers and genes related to lipid synthesis, in line with the exacerbation of high-fat-induced fatty liver in these mice. The HELP-tagging assay was used to identify differentially methylated CpG sites in the lingonberry group compared to the high-fat control group. Lingonberries induced genome-wide and specific alterations of DNA methylation, however the significance of these findings remains to be established. Furthermore, different batches of lingonberries were found to have different capacity to prevent obesity. However lingonberries prevented low-grade inflammation, metabolic endotoxemia and modified the gut microbiota of high-fat fed mice, including increasing the Firmicutes/Bacteroidetes ratio. These findings were independent of effects on body weight gain and achieved regardless of the source of berries. The capacity of lingonberries to counteract negative outcomes of an unhealthy diet should be further evaluated in humans, including assessment of anti-inflammation and microbiota modulation. The generated knowledge about berries and their effects on metabolism may be useful in designing future dietary strategies aimed at preventing metabolic disease.
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| 50. |
- Leja, Justyna, 1982-
(författare)
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Oncolytic Adenovirus Therapy of Neuroendocrine Tumors
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Neuroendocrine tumors (NETs), originally described as carcinoids, represent a rare and heterogeneous group of neoplasms associated with intensive secretion of hormones, bioactive peptides and amines. Most of the patients are diagnosed at a late stage of disease, often with liver metastases. Surgery remains the main treatment to control metastatic disease, but is not curative. Oncolytic virotherapy represents a promising approach to treat cancer and different strategies have been exploited to restrict viral replication to tumor cells. We developed an oncolytic adenovirus based on serotype 5, Ad5[CgA-E1A], where the chromogranin A (CgA) promoter controls expression of the E1A gene and thereby virus replication. We found that Ad5[CgA-E1A], selectively replicates in NET cells and it is able to suppress fast-growing human BON carcinoid tumors in nude mice. The activity of Ad5[CgA-E1A] was not completely blocked in liver cells. We further repressed virus replication in hepatocytes by targeting E1A with miR122, an miRNA specifically expressed in the liver. miRNAs bind to mRNA and induce its cleavage or translational blockage. By insertion of tandem repeats of miR122 target sequences in 3’UTR of E1A gene, we observed reduced E1A protein expression and replication arrest in miR122 expressing liver cells. The oncolytic potency of the miR122-targeted virus was not affected in NET cells. Since some NET and neuroblastoma cells express high levels of somatostatin receptors (SSTRs), we introduced in the virus fiber knob cyclic peptides, which contain four amino acids (FWKT) and mimic the binding site of somatostatin for SSTRs. The FWKT-modified Ad5 transduces midgut carcinoid cells from liver metastases about 3-4 times better than non-modified Ad5. Moreover, FWKT-modified Ad5 overcomes neutralization in an ex vivo human blood loop model to a greater extent than Ad5, indicating that the fiber knob modification may prolong the systemic circulation time. NETs represent a huge therapeutic challenge and novel diagnostic markers are needed for early detection and effective treatment of NETs. We have profiled primary tumors and liver metastases of ileocaceal NETs, using Affymetrix microarrays and advanced bioinformatics. We have identified six novel marker genes and show high similarity between primary lesions and liver metastases transcriptome by hierarchical clustering analysis.
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