Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 4 uppsatser.

C1q TNF-related protein-3 (CTRP3) is effective at preventing high-fat diet-induced fatty liver; Recent studies have shown that overexpression of C1q TNF-related protein-3 (CTRP3) in mice fed a high alcohol diet can protect the animal from developing fatty liver disease, and therefore may be a possible treatment for alcoholic fatty liver disease (ALD). However, the possible effects of overexpression of CTRP3 on other tissue has not been widely investigated. If overexpression of CTRP3 proves to be harmful to other tissues, its use as a treatment for ALD would come into question. This study utilized kidney tissue from mice that were fed a high fat diet for 13-14 weeks. The feeding started when the mice were 7 weeks old and continued for 9 weeks. The mice were divided into 4 categories: wild-type/low fat diet, wild-type/high fat diet, transgenic/low fat diet, and transgenic/high fat diet. The kidneys were harvested and fixed in 4% paraformaldehyde and subsequently paraffin embedded. Sections were cut at 4µ and stained using three different staining techniques: standard H&E, Periodic Acid Schiff (PAS), and Masson’s Trichrome Staining. These three methods were utilized to better visualize possible effects on the tissue, i.e. changes in connective tissue deposition or basement membrane thicknesses, etc. Light microscopic examination of the tissues to date has revealed abnormalities in some of the kidney tubules in the transgenic high fat diet group. These same abnormalities have not been observed in the other treatment groups. This study is still in its early stages and much more in-depth investigation is needed to determine which of the tubules of the nephron are affected, and what this effect is. If this study confirms that overexpression of CTRP3 coupled with a high fat diet is harmful to kidney tissues, the use of CTRP3 in the treatment of ALD would require careful monitoring of the patient’s diet.

La douleur neuropathique suite à une lésion d'un nerf périphérique est une condition répandue pour laquelle aucun traitement efficace n'est disponible. Sans nier le rôle joué par les neurones au niveau du système nerveux central (SNC), des données récentes ont démontré la participation active des cellules gliales dans le développement de la douleur neuropathique. En effet, des études ont montré un rôle critique des cellules gliales dans l'initiation et la maintenance de l'hypersensibilité liée à la douleur. Cependant, les origines de ces cellules gliales activées et les déclencheurs de leur activation n'ont pas encore été élucidés. Nous avons démontré dans cette étude que suite à une blessure au nerf périphérique, causée par la ligation partielle du nerf sciatique, en plus des l'activation de microglies résidentes du SNC, les cellules hématogènes, macrophages/monocytes, infiltrent la moelle épiniere, prolifèrent et se différencient en microglies ramifiées. La signalisation entre la chimiokine "monocyte chemoattractant protein-1" (MCP-1, CCL2) et son récepteur CCR2 est critique dans l'activation des cellules microglials de la moelle épiniere. En effet, l'injection intrathécale de MCP-1 exogène entraine l'activation des microglies chez des souris sauvages, mais pas chez des souris déficientes en CCR2. De plus, un traitement avec un anticorps neutralisant dirigé contre MCP-1 a empêché l'infiltration de cellules microglials dérivées de la moelle osseuse (MDMO) dans la moelle épiniere après le dommage du nerf sciatique. En utilisant les souris CCR2 knock-out-sélectif dans la microglie résidente ou la MDMO, nous avons constaté que, bien que des souris CCR2 knock-out-total n'ont pas développé l'activation microgliale ni l'allodynie mécanique, l'expression de CCR2 soit dans les microglies résidentes ou dans les MDMO est suffisante pour le développement d'allodynie mécanique. Ainsi, pour soulager de façon efficace la douleur neuropathique, il faut viser non seulement la microglie résidente du SNC, mais aussi la microglie provenant de la circulation sanguine. Ces découvertes ouvrent la porte pour une nouvelle stratégie thérapeutique: on peut profiter de la capacité naturelle des cellules dérivées de la moelle osseuse qui s'infiltrent sélectivement des régions affectées du SNC en utilisant ces cellules comme le véhicule pour la livraison de médicaments afin de contrôler l'hypersensibilité et la douleur chronique.

Endometrial adenocarcinoma is the most common gynaecological malignancy in Western countries, affecting mainly post-menopausal women with a frequency of 15-20 per 100 000 women per year. Over-expression of the cyclooxygenase (COX) enzymes and prostaglandin receptors has been demonstrated in endometrial adenocarcinoma as well as other gynaecological pathologies. Increased expression of the prostaglandin F2α (PGF2α) receptor (FP) has been previously demonstrated in endometrial adenocarcinoma. A role for the FP receptor in the promotion of endometrial adenocarcinoma has been shown, with evidence for elevated PGF2α-FP signalling up-regulating angiogenic and tumourigenic genes, and increasing proliferation and migration of neoplastic epithelial cells. This thesis examines signalling pathways regulated by and interacting with the FP receptor that influence chemokine expression and subsequent effects in endometrial adenocarcinoma. To investigate PGF2α-FP interactions in endometrial adenocarcinoma, an endometrial epithelial cell line of adenocarcinoma origin (Ishikawa cells) stably transfected with the FP receptor to levels seen in cancer was used (FPS cells). An antibody array identified the chemokine C-X-C motif Ligand 1 (CXCL1) as a target gene regulated by PGF2α-FP signalling in this cell line. Expression of CXCL1 and its receptor, CXCR2, were elevated in cancer tissue as compared to normal endometrium and localised to glandular epithelium, endothelium and stroma. The induction of CXCL1 expression in FPS cells and endometrial adenocarcinoma explants was determined to be by a signalling pathway involving Gq, the epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase (ERK). The infiltration of immune cells into endometrial adenocarcinoma as compared to normal endometrium was then investigated. Increased neutrophils were present in endometrial adenocarcinoma compared with normal endometrium, and the expression of CXCR2 was colocalised to neutrophils. In vitro chemotaxis assays demonstrated that conditioned media from PGF2α-treated FPS cells stimulated human neutrophil chemotaxis which could be abolished by CXCL1 protein immunoneutralisation from the conditioned media or antagonism of CXCR2 on neutrophils. Moreover, xenograft tumours in nude mice arising from inoculation with FPS cells had higher neutrophil infiltration compared to tumours arising from wild-type cells or following treatment of mice bearing FPS tumours with CXCL1-neutralising antibody. Therefore, the up-regulation of CXCL1 by PGF2α promoted neutrophil chemotaxis into endometrial adenocarcinoma. The expression of a further chemokine, CC motif Ligand 20 (CCL20) was determined to be regulated by PGF2α -FP signalling in endometrial adenocarcinoma, and expression of CCL20 and its receptor CCR6 was elevated in endometrial adenocarcinoma. The induction of CCL20 by PGF2α -FP signalling in FPS cells was dependent on the signalling molecules Gq, EGFR, ERK, calcineurin and nuclear factor of activated T-cells (NFAT). The treatment of endometrial epithelial cells with recombinant CCL20 caused a significant increase in proliferation. Finally interactions between the signalling pathway of another pro-inflammatory lipid, lysophosphatidic acid (LPA), and FP receptor signalling in endometrial adenocarcinoma were examined. LPA increased expression of the FP receptor and the FP target genes previously discussed in this thesis, CXCL1 and CCL20, in FPS cells. Expression of the LPA receptors (LPAR) 1, 2 and 3 was localised in endometrial tissue, and LPAR2 and 3 were found to be elevated in endometrial adenocarcinoma compared with normal endometrium, suggesting amplification of the PGF2α -FP signalling pathway by LPA was possible. Collectively, these data demonstrate that inflammatory cytokine signalling pathways regulated by PGF2α-FP activation can promote immune cell infiltration and proliferation of endometrial adenocarcinoma, and that interaction of LPA and PGF2α-FP signalling in endometrial adenocarcinoma may exacerbate the disease.

published_or_final_version / Pathology / Doctoral / Doctor of Philosophy

published_or_final_version / Paediatrics / Doctoral / Doctor of Philosophy

Acute allograft rejection remains a major problem in solid organ transplantation, because rejection may lead to acute or chronic loss of graft function. The failure of certain anti-rejection prophylactic treatments suggests that several unexpected pathways might be involved in the rejection process. The aim of our experiments was to investigate the effector mechanisms responsible for skin graft rejection in mice. To adress this question, we took advantage of the possibility to restrict the alloimmune response to isolated allogeneic MHC class II molecules or to isolated minor transplantation antigens, combined with the possibility to study separately the response of CD4+ or CD8+ T cells in mice deficient for Th1 or Th2 cytokines or cytotoxic molecules. We used the bm12 skin graft combination (C57BL/6 H2Kbm12 grafted on C57BL/6 H2Kb) as a model of single MHC class II disparity and the b2microglobulin skin graft model (C57BL/6 b2m+/+ grafted on C57BL/6 b2m-/-) as a model of minor transplantation antigen disparity. Our goal was to engage a limited number of effectors, trying in a second time to block each rejection pathway selectively. We showed that Fas/FasL-mediated CD4+ T cells cytotoxicity, eosinophil recruitment, activation and degranulation induced by Th2 derived cytokines, and CD4-derived IFN-g production are involved in the rejection of grafts bearing either a single MHC class II disparity or b2m-derived minor histocompatibilty antigens. In addition, rejection of MHC class II disparate skin grafts also includes the participation of neutrophils, in particular conditions where the occurrence of the Th2/eosinophil pathway was prevented. Altogether, our data show a multiplicity and a redundancy of the effector pathways participating in allograft rejection. Among the different effectors pathways identified, including effectors from both innate and adaptive immune systems, some act synergistically, whereas others act as alternative pathways, depending of the degree of donor-recipient mismatch.

No description available.

No description available.