Asthma is a chronic obstructive pulmonary disease (COPD) which affects 1 in every 12 Americans. Symptoms common to asthmatics include dyspnea, increased mucous production and airway hyperresponsiveness. While research over the past few decades has mostly established the immunological basis behind asthma, there have not been radical changes in the treatment modalities. It is believed that in many COPDs, alveolar macrophages play a critical role in disease progression. While evolutionarily, alveolar macrophages played a significant part in protecting the individual from harmful allergens, in asthma there may be an inappropriate activation of the alveolar macrophages to proteases such as cockroach allergen (CRA). Studies show that children living in inner cities with cockroach infestation are more likely to develop asthma than those that reside in rural areas with less exposure to cockroach allergens. In exposed individuals, when the alveolar macrophages come in contact with CRA, an immune cascade is initiated which sensitizes the child. Subsequent exposure to such an antigen will induce asthma like symptoms. One possible way of reducing such a response is to reduce the number of alveolar macrophages thus avoiding the pathalogical effects. Clodronate liposomes are liposomes that are encapsulated with bisphosphonate clodronate. When a macrophage phagocytoses such a liposome, the result is cellular suicide or apoptosis. In this study, we sensitized a murine model of CRA asthma and then monitored the impact of depleted alveolar macrophages using intratracheal administration of clodronate liposomes. We then studied the effect of this depletion on the recruitment of inflammatory cells such as neutrophils and eosinophils which are primary cellular contributors to the asthmatic response. Our studies show that while clodronate liposomes are effective in alveolar macrophage depletion, the subsequent inflammation through neutrophil recruitment interferes with the study of the delicate milieu of cells in the respiratory epithelium of this murine model.

Orientador: Karina Gottardello Zecchin / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-19T22:07:17Z (GMT). No. of bitstreams: 1 Gomes_CamillaBorgesFerreira_M.pdf: 2172456 bytes, checksum: 5dd9bb49385077ce4213db57e518b145 (MD5) Previous issue date: 2012 / Resumo: O comprometimento ósseo em pacientes com câncer é responsável por significativas morbidade e redução da qualidade de vida, principalmente quando se trata de câncer de mama, no qual o esqueleto é o principal sítio de desenvolvimento das metástases. Bisfosfonatos (BPs) contendo ou não nitrogênio são os principais agentes usados no combate à perda óssea como na osteoporose, uma vez que induzem apoptose de osteoclastos. Recentemente foram demonstradas ações antitumoral e antiangiogência dos BPs, in vitro e in vivo. Desse modo, o objetivo deste trabalho foi analisar e comparar os efeitos antitumorais e antiangiogênicos de BP que não contêm nitrogênio (clodronato, CLO) e BP contendo nitrogênio (ácido zoledrônico, ZOL), em linhagem celular derivada de câncer de mama, MCF-7, e em culturas de células endoteliais. Os resultados mostram que ZOL reduziu a proliferação das MCF-7 de maneira dose-dependente, com aumento do número de células nas fases G0/G1, sem alterar a viabilidade. Paralemamente, CLO não mostrou nenhum efeito sobre as células tumorais. O tratamento de células endoteliais de coelho, RAEC, com ZOL ou CLO reduziu a proliferação celular derivada, sem alterar sua viabilidade. Células endoteliais humanas HUVEC mostraram 15% de redução da viabilidade quando tratadas com ZOL, enquanto CLO não mostrou efeitos citotóxicos. A incubação de células HUVEC com meio condicionado por células MCF-7 tratadas com ZOL culminou na redução da proliferação das células endoteliais e na redução da formação de estruturas semelhantes a vasos, in vitro. Esse mesmo meio condicionado pelas células tumorais tratadas com ZOL resultou em menor proliferação de células provenientes de aorta murina, em ensaio ex vivo. Ensaios de imunoabsorbância revelaram diminuição nos níveis de VEGFA total nesse meio condicionado, assim como aumento da quantidade da isoforma antiangiogênica VEGFA165b, após tratamento das MCF-7 com ZOL. Por último, o tratamento das células MCF-7 com ZOL modulou a expressão de VEGFA total e de suas isoformas. Em conjunto, estes achados mostram que ZOL exibe ação antitumoral e antiangiogênica em células de câncer de mama e em células endoteliais. Tais dados contribuem para um maior esclarecimento sobre os mecanismos de ação dos BPs, permitindo buscas por melhorias no uso desses agentes como coadjuvantes na quimioterapia, a fim de minimizar a morbidade decorrente de metástases ósseas em tumores malignos / Abstract: Patients with cancer frequently develop bone metastasis, resulting in considerable morbidity and affecting quality of life. This is particularly important considering breast cancer, in which skeletal is the main site for metastasis. Non-nitrogen-containing and nitrogen-containing bisphosphonates (BPs) are the mainly agents to treat bone loss due to osteoporosis, Paget disease, bone metastasis, multiple myeloma, hypercalcemia and osteogenesis imperfecta. BPs impair bone loss by inducing apoptosis in osteoclasts. Recently it was shown anti-tumoral and anti-angiogenic effects of BPs, in vitro and in vivo. The present study aim to analyze and compare the anti-angiogenic pathway of the non-nitrogen-containing BP, clodronate (CLO), and the nitrogen-containing BP, zoledronic acid (ZOL), using estrogen receptor-positive breast cancer cell line, MCF-7, and endothelial cells. ZOL treatment reduced MCF-7 cell proliferation and induced cell cycle arrest in a dose-dependent manner, while CLO did not affect these cells. Treatment with ZOL or CLO also reduced RAEC cells proliferation, without changes in cell viability. HUVEC cells showed reduced viability after incubation with ZOL, but not with CLO. The conditioned medium by MCF-7 ZOL-treated cells reduced the formation of blood vessels in vitro and proliferation of HUVEC cells, together with lower endothelial cells proliferation derived from mouse aortic rings. Enzyme-linked immunoabsorbent assay showed reduction of ~25% in VEGFA levels, and increased amount of VEGFA165b isoform in the conditioned medium by ZOL-treated MCF-7 cells. The nitrogen-containing BP also modulated the expression of mRNAs for VEGF in MCF-7 treated cells. In all assays, CLO showed less anti-angiogenic properties when compared with ZOL. Data provided from this study amplify the knowledge of BPs actions, contributing for new approaches of bone metastases in malignant tumors / Mestrado / Estomatologia / Mestre em Estomatopatologia

Olfactory sensory neurons (OSNs) undergo continual degeneration and replacement throughout life, a cycle that can be synchronized experimentally by performing olfactory bulbectomy (OBX). OBX induces apoptosis of mature OSNs, which is followed by an increase in the proliferation of progenitor basal cells. Macrophages, functionally diverse immune effector cells, phagocytose the apoptotic OSNs and regulate the proliferation of basal cells. This provides an advantageous environment to study how macrophages regulate neuronal death, proliferation, and replacement. The purpose of this dissertation was to identify the cellular and molecular mechanisms by which macrophages regulate the degeneration/proliferation cycle of OSNs. Macrophages were selectively depleted using liposome-encapsulated clodronate (Lip-C). Intranasal and intravenous administration of Lip-C decreased the number of macrophages in the OE of sham and OBX mice by 38% and 35%, respectively, compared to mice treated with empty liposomes (Lip-O). Macrophage depletion significantly decreased OE thickness (22% and 21%, p<0.05), the number of mature OSNs (1.2- and 1.9-fold, p<0.05), and basal cell proliferation (7.6- and 3.8-fold, p<0.05) in sham and OBX mice, respectively, compared to Lip-O mice. Additionally, at 48 h following OBX, OSN apoptosis increased significantly (p<0.05) in the OE of Lip-C mice compared to Lip-O mice. A microarray analysis was performed to identify the genomic changes underlying the cellular changes associated with macrophage depletion. There were 4,024 genes with either a significant interaction between group (Lip-C vs. Lip-O) and treatment (OBX vs. sham) or a significant main effect. There were a number of significantly regulated immune response and cytoskeletal genes, and genes encoding neurogenesis regulators and growth factors, most of which were expressed at lower levels in Lip-C mice compared to Lip-O mice. Sdf1, the ligand for the chemokine receptor Cxcr4 involved in leukocyte trafficking, axon guidance, and cell migration, was localized to macrophages on the protein level. Additionally, the microarray expression pattern of Hdgf, a growth factor that promotes neuronal survival and proliferation, was validated on the protein level using immunohistochemistry. HDGF appeared to be localized to basal cells and OSNs where it could act as a proliferative or survival factor whose expression is regulated in part by macrophages.

The Affymetrix GeneChip® Canine Genome 2.0 microarray is re-annotated using AgBase tools, up-to-date ID mapping and GO annotations associated with publicly available gene products updated on this array. This re-annotation makes the array more useful for researchers using the canine microarray for biological discovery. We use flow cytometry to determine if liposomal clodronate (LC) is an acceptable alternative to surgical splenectomy to facilitate detection of subclinical infection with Babesia canis in potential blood donor greyhounds. Our study shows that LC is not a reliable means of exposing babesiosis in greyhounds with a recent history of infection. We evaluate the effect of depletion of antigen presenting cells on regulatory T cells (Tregs) in dogs treated with LC by multi-color flow cytometry. We demonstrate that LC promotes increases in the CD4+CD25+FOXP3+ Tregs affecting mostly the CD4+CD25lowFOXP3+ Tregs subset suggesting a role of monocytes in naïve T cell priming and differentiation into Tregs.

No description available.

Microglia and brain-resident macrophages are the sentinel immune cells of the central nervous system (CNS), and are ideally situated to respond to any damage to the brain parenchyma or vasculature. Circulating leukocytes are generally excluded from the CNS environment under homeostatic conditions but can gain access to this region in diseases that disrupt immune system function and blood-brain barrier integrity. Although these diverse immune cells exhibit properties that may engender them to be well-suited to resolve microcirculatory insults, their relative contributions to the recanalization of capillary rupture in the cortex, known as cerebral microbleeds (CMBs), has yet to be described. CMBs are particularly concerning in conditions, such as diabetes mellitus (DM), in which these insults occur more frequently and potentially underlie the onset and progression of cognitive decline. Using in vivo 2-photon microscopy and confocal imaging, here I highlight the compromised repair of CMBs in a mouse model of type 1 DM and characterize the robust, heterogeneous macrophage response to these insults. Specifically, 20% of damaged capillaries were eliminated from the circulation in the diabetic cortex and chronic insulin treatment failed to prevent this microvascular loss. Administration of interferon-α or interferon-γ neutralizing antibodies to dampen inflammatory signalling, or dexamethasone to reduce global inflammation, also failed to improve repair rates of damaged microvessels in diabetic mice. In contrast, CMBs in nondiabetic mice repaired without exception. Interestingly, depletion of CNS macrophages using the colony stimulating factor-1 receptor antagonist PLX5622 resulted in microvascular elimination in nondiabetic mice. Given the robust depletion of brain macrophage populations with this treatment, at first these data suggested that these cells were necessary for microvascular repair since their elimination produced vessel loss. However, by parsing the data I identified that microvessels repaired in all cases where macrophages were not identified at the CMB; when CX3CR1+ aggregate was localized to the injury, ~20% of microvessels were eliminated. These findings show that CNS macrophages are not required for microvascular repair following CMB. Immunofluorescent co-labelling of various microglial and macrophage markers within the diabetic CMB milieu revealed a novel population of Mac2+/TMEM119- cells, distinct from homeostatic TMEM119+ microglia. These cells reliably localized to CMBs that failed to repair and rarely associated with vessels that recanalized; Mac2+/TMEM119- cells were not found within nondiabetic CMBs. Treatment of diabetic mice with clodronate liposomes (CLR) to deplete circulating phagocytic leukocytes prevented aggregation of Mac2+/TMEM119- cells to CMBs and improved capillary repair rates. The efficacy of CLR in excluding these cells from the CMB aggregate, coincident with eradication of monocytes from circulation, indicated that these cells likely arose from the periphery. In vivo 2-photon imaging revealed significant increases in lipofuscin at the site of diabetic CMBs relative to the nondiabetic context; other phagocytic markers including CD68 and TREM2 were also upregulated. Mac2+/TMEM119- cells showed elevated lipofuscin content relative to homeostatic microglia; their association with CMBs may thus signal an increase in phagocytosis that contributes to capillary pruning. Taken together, these data identify a novel Mac2+/TMEM119- macrophage associated with pathological microvascular elimination following CMB in the diabetic neocortex. These findings highlight the diversity of immune cell responses to CNS injury and provide insights into the cellular mechanisms of capillary pruning. Furthermore, these advances in our understanding of the regulation of microvascular elimination in the diabetic brain may have clinical implications for patients with DM as they provide evidence for putative adjuvant anti-inflammatory treatments, such as CLR, in mitigating cerebrovascular pathology. / Graduate / 2022-05-06

Experimentelle Melanin-induzierte Uveitis (EMIU): Modulation der Leukozyten-Endothelzell-Interaktion durch Makrophagendepletion - intravitalmikroskopische Analysen. Einleitung: Die Experimentelle Melanininduzierte Uveitis (EMIU) dient als Modell für eine autoimmune Iridozyklitis und Choroiditis. Die frühe Entzündungsreaktion ist durch eine gesteigerte Leukozyten-Endothel-Interaktion gekennzeichnet. Um die Rolle von Makrophagen bei der Induktion der EMIU zu untersuchen, analysierten wir Veränderungen der Leukozyten-Endothel-Interaktionen in Irisvenolen anästhesierter Ratten nach Makrophagendepletion mit liposomalem Clodronat. Methoden: Die EMIU wurde durch intraperitoneale Injektion einer Emulsion aus 250 µg bovinen Melanosomen in komplettem Freund Adjuvant und Pertussistoxin bei Lewis Ratten induziert. Die Tiere wurden mit 2 ml Clodronat-Liposomen (Clodronat-lip) an den Tagen 2; 1; 4; 6 beziehungsweise 8 nach Immunisierung behandelt. Kontrolltiere erhielten anstelle von Clodronat-lip Leerliposomen (Kontrolle). Für die Intravitalfluoreszenzmikroskopie wurden Leukozyten intravasal mit Rhodamin 6G gefärbt. Anschließend wurden die postkapillären Irisvenolen am 4.; 6.; 8. und 10. Tag untersucht, um die Zahl der rollenden und fest am Endothel adhärenten Leukozyten zu quantifizieren. Weitere Parameter wie Zellzahl und Proteingehalt des Kammerwassers, TNF-alpha und IFN-gamma im Plasma und das Differentialblutbild wurden zur Charakterisierung der Entzündungsreaktion herangezogen. Ergebnisse: Bei makrophagendepletierten Tieren konnten spaltlampenmikroskopisch keine entzündlichen Veränderungen des Vorderabschnittes beobachtet werden. Der prozentuale Anteil rollender Leukozyten war am 8. Tag mit 2 +/- 1.1 vs. 15.2 +/- 1.6; 5.2 +/- 0.5% (Clodronat-lip vs. EMIU; Kontrolle, Mittelwert +/- MSF, ANOVA, p