Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by abnormalities in multiple components of the immune system resulting in progressive damage to multiple organs. Current treatments for SLE are often intensive and result in side effects and the potential for continued flares and progression of disease. Histone deacetylase (HDAC) enzymes control multiple cellular functions by removing acetyl groups from lysine residues in various proteins. HDAC inhibitors have been investigated as a potential treatment for SLE with promising results, however selective HDAC6 inhibition (HDAC6i) has become a leading candidate for pharmacologic inhibition to reduce the potential for side effects. We hypothesize that HDAC6i will decrease SLE disease by targeting substrates of HDAC6 in multiple components of immunity and organ systems. NZB/W mice were treated with ACY-738 or ACY-1083, followed by evaluation of multiple disease parameters and mechanisms involved in disease pathogenesis within the kidney, bone marrow, and spleen. Within the kidney, HDAC6i decreased glomerular pathology scores, proteinuria, and IgG and C3 deposition. Within glomerular cells, HDAC6i increased alpha-tubulin acetylation and decreased nuclear NF-κB. Within the spleen, there was a dose-dependent decrease in the frequency of Th17 cells and a mild decrease in the frequency of Treg cells. Concurrently, there were decreased levels of IL-12/IL-23 and minimal decreases in TGF-β in the serum. Within the bone marrow, B cell development through Hardy fractions exhibited accelerated progression through later stages as NZB/W mice aged. This accelerated progression may allow B cells to bypass important regulatory checkpoints in maintaining immune tolerance and contribute to autoimmunity. Treatment with an HDAC6i corrected the aberrant B cell development in the bone marrow and RNAseq analysis unveiled six genes (Cebpb, Ccr9, Spib, Nfil3, Lgals1, and Pou2af1) that may play a role in the aforementioned abnormalities. Overall, these findings show that HDAC6i decreased disease in NZB/W mice by targeting multiple components of the immune response, including glomerular cells, T cell subsets in the spleen, and bone marrow B cells. In conclusion, selective HDAC6i is an excellent candidate for pharmacologic therapy for SLE because it targets multiple immune abnormalities involved in SLE pathogenesis while remaining selective and safe. / Ph. D. / Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by multiple abnormalities in the immune system resulting in progressive immune-mediated damage to multiple organs. Current treatment regimens are often intensive, result in side effects, and may only provide temporary relief of disease. Histone deacetylase (HDAC) inhibition is currently being investigated as a new treatment modality for SLE with aims for improved efficacy and decreased potential for unwanted side effects. HDAC enzymes remove acetyl groups from multiple proteins (substrates) and subsequently regulate their function. HDAC6 is a specific HDAC enzyme that is of particular interest and are the subject of the following studies. These studies hypothesize that HDAC6 inhibition will decrease SLE by targeting multiple protein targets involved in the immune-mediated pathway of disease initiation and progression. NZB/W mice were utilized as a model of the human disease, and were treated by HDAC6 inhibitors during various stages of disease progression. Long-term treatment initiated early in disease decreases disease as evidenced by decreased renal pathology scores, immune complex deposition in the kidneys, decreased T cell subtypes in the spleen, and decreased inflammatory cytokines. HDAC6 inhibition corrects abnormal B cell development within the bone marrow of NZB/W mice, which is otherwise altered during disease progression. Furthermore, HDAC6 inhibition altered gene expression within the bone marrow, and deep sequencing analysis revealed multiple genes that may be involved in the pathway of disease progression. Overall, HDAC6 inhibition targets multiple pathways involved in SLE disease initiation and progression in various organs including the bone marrow, spleen, and kidneys. Because SLE is a disease that is multi-factorial and effects multiple organs, it would be ideal that a potential drug therapy also targets multiple targets and organ systems while remaining safe to use. Based on these studies, HDAC6 inhibitors are excellent candidates for the treatment of SLE.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol inst., 2004. / Härtill 5 uppsatser + appendix.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2005. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 5 uppsatser.

Base teórica: doenças linfoproliferativas crônicas de linhagem B (DLPC-B) são neoplasias clonais que afetam linfócitos B maduros. A tirosina quinase de Bruton (do inglês Bruton’s tyrosine kinase, BTK) é uma proteína essencial para o desenvolvimento, diferenciação e sinalização nos linfócitos B. Ki-67 é uma proteína nuclear associada à proliferação celular. A avaliação de proteínas envolvidas nas vias de sinalização oncogênicas pode levar ao aprimoramento do diagnóstico, tratamento e definição de prognóstico das DLPC-B. Objetivo: avaliar a expressão de BTK e Ki-67 em linfócitos de portadores de DLPC-B. Métodos: para avaliação de BTK foi realizado um estudo transversal; foi avaliada a expressão de BTK em amostras de pacientes saudáveis e de pacientes com diagnóstico de DLPC-B. Para avaliação de Ki-67 foi realizado um estudo transversal. As amostras foram marcadas com CD45 FITC e CD19 APC para identificação dos linfócitos B. Após a lise das hemácias, foi realizada marcação citoplasmática de BTK PE e/ou Ki-67 PerCP-Cy5.5. O percentual de expressão e a intensidade de fluorescência média (IFM) dos marcadores avaliados foram determinados nos linfócitos B. A análise estatística foi realizada com testes de correlação de Pearson e Spearman entre BTK ou Ki-67 e as demais variáveis clínicas e laboratoriais, e ANOVA seguido por teste post hoc de Bonferroni para comparações entre grupos. Foi considerado resultado significante quando P < 0,05. Resultados: não foram observadas diferenças na expressão de BTK e não houve associação entre a expressão de BTK e as variáveis clínicas avaliadas. A expressão de Ki-67 foi maior nos grupos linfoma do manto, linfoma de Burkitt e linfoma difuso de grandes células B em relação aos demais; após análise multivariada, a IFM de Ki-67 foi associada à IFM de CD38. Conclusão: no presente trabalho, a expressão de BTK em DLPC-B foi similar a de linfócitos B normais e a expressão de Ki-67 foi maior nas DLPC-B com curso clínico mais agressivo. / Background: mature B-cell neoplasms (MBCN) are clonal neoplasms that affect mature B-cell lymphocytes. Bruton’s tyrosine kinase (BTK) is an essential protein for the development, differentiation and signaling in B-cell lymphocytes. Ki-67 is a nuclear protein associated to cellular proliferation. Evaluation of proteins involved in oncogenic signaling pathways can lead to improvement in the diagnosis, treatment and prognosis definition in MBCN. Objective: to evaluate the expression of BTK and Ki-67 in lymphocytes of MBCN patients using flow cytometry. Methods: a cross-sectional study was conducted for BTK assessment; BTK expression was assessed on healthy patients samples and MBCN samples. For evaluation of Ki-67 a cross-sectional study was conducted. Samples were stained with CD45 FITC and CD19 APC for identification of B-cell lymphocytes. After lysis of red blood cells, cytoplasmic staining of BTK PE and/or Ki-67 PerCP-Cy5.5 was performed. Percentage of expression and mean fluorescence intensity (MFI) of the markers were determined in B-cell lymphocytes. Statistical analysis was performed with Pearson and Spearman correlation tests between BTK and Ki-67 and the other clinical and laboratory variables, and ANOVA followed by post-hoc Bonferroni test for comparisons between groups. Results were considered significant when P < 0.05. Results: no differences in BTK expression were identified and there was no association between BTK expression and clinical variables evaluated. Ki-67 expression was higher in mantle cell lymphoma, Burkitt lymphoma and diffuse large B-cell lymphoma cases; after multivariate analysis, MFI of Ki-67 was associated with MFI of CD38. Conclusions: in this study, BTK expression in B-cell neoplasms was similar to that of normal B-cell lymphocytes and Ki-67 expression was higher in MBCN with more aggressive clinical courses.

Uncovering the chromosomal abnormalities associated with human malignancy can provide significant insights into the molecular basis of tumorigenesis, as well as identifying potential targets for therapy. The present study set out to examine the genetic characteristics of t(2;7)(p11-12;q21-22) translocations arising in conjunction with chronic B-cell neoplasia. Using long-range PCR, a t(2;7) was initially mapped in an individual presenting with the preclinical entity CD5- monoclonal B-cell lymphocytosis. This revealed a breakpoint at 2p11.2 localized to the recombination signal of the immunoglobulin kappa (IGK) variable gene IGKV3-15, and a breakpoint at 7q21.2 located 520 bp upstream of cyclin dependent kinase 6 (CDK6). The same approach was subsequently employed to elucidate near-identical t(2;7) breakpoints in 4 additional cases presenting with chronic lymphocytic leukemia or indolent non-Hodgkin lymphomas. The remarkable consistency of these translocations implicates the dysregulation of CDK6 via translocation to IGK as a recurrent pathomechanism during the emergence of B-cell lymphoproliferative disorders.

Uncovering the chromosomal abnormalities associated with human malignancy can provide significant insights into the molecular basis of tumorigenesis, as well as identifying potential targets for therapy. The present study set out to examine the genetic characteristics of t(2;7)(p11-12;q21-22) translocations arising in conjunction with chronic B-cell neoplasia. Using long-range PCR, a t(2;7) was initially mapped in an individual presenting with the preclinical entity CD5- monoclonal B-cell lymphocytosis. This revealed a breakpoint at 2p11.2 localized to the recombination signal of the immunoglobulin kappa (IGK) variable gene IGKV3-15, and a breakpoint at 7q21.2 located 520 bp upstream of cyclin dependent kinase 6 (CDK6). The same approach was subsequently employed to elucidate near-identical t(2;7) breakpoints in 4 additional cases presenting with chronic lymphocytic leukemia or indolent non-Hodgkin lymphomas. The remarkable consistency of these translocations implicates the dysregulation of CDK6 via translocation to IGK as a recurrent pathomechanism during the emergence of B-cell lymphoproliferative disorders.

Base teórica: doenças linfoproliferativas crônicas de linhagem B (DLPC-B) são neoplasias clonais que afetam linfócitos B maduros. A tirosina quinase de Bruton (do inglês Bruton’s tyrosine kinase, BTK) é uma proteína essencial para o desenvolvimento, diferenciação e sinalização nos linfócitos B. Ki-67 é uma proteína nuclear associada à proliferação celular. A avaliação de proteínas envolvidas nas vias de sinalização oncogênicas pode levar ao aprimoramento do diagnóstico, tratamento e definição de prognóstico das DLPC-B. Objetivo: avaliar a expressão de BTK e Ki-67 em linfócitos de portadores de DLPC-B. Métodos: para avaliação de BTK foi realizado um estudo transversal; foi avaliada a expressão de BTK em amostras de pacientes saudáveis e de pacientes com diagnóstico de DLPC-B. Para avaliação de Ki-67 foi realizado um estudo transversal. As amostras foram marcadas com CD45 FITC e CD19 APC para identificação dos linfócitos B. Após a lise das hemácias, foi realizada marcação citoplasmática de BTK PE e/ou Ki-67 PerCP-Cy5.5. O percentual de expressão e a intensidade de fluorescência média (IFM) dos marcadores avaliados foram determinados nos linfócitos B. A análise estatística foi realizada com testes de correlação de Pearson e Spearman entre BTK ou Ki-67 e as demais variáveis clínicas e laboratoriais, e ANOVA seguido por teste post hoc de Bonferroni para comparações entre grupos. Foi considerado resultado significante quando P < 0,05. Resultados: não foram observadas diferenças na expressão de BTK e não houve associação entre a expressão de BTK e as variáveis clínicas avaliadas. A expressão de Ki-67 foi maior nos grupos linfoma do manto, linfoma de Burkitt e linfoma difuso de grandes células B em relação aos demais; após análise multivariada, a IFM de Ki-67 foi associada à IFM de CD38. Conclusão: no presente trabalho, a expressão de BTK em DLPC-B foi similar a de linfócitos B normais e a expressão de Ki-67 foi maior nas DLPC-B com curso clínico mais agressivo. / Background: mature B-cell neoplasms (MBCN) are clonal neoplasms that affect mature B-cell lymphocytes. Bruton’s tyrosine kinase (BTK) is an essential protein for the development, differentiation and signaling in B-cell lymphocytes. Ki-67 is a nuclear protein associated to cellular proliferation. Evaluation of proteins involved in oncogenic signaling pathways can lead to improvement in the diagnosis, treatment and prognosis definition in MBCN. Objective: to evaluate the expression of BTK and Ki-67 in lymphocytes of MBCN patients using flow cytometry. Methods: a cross-sectional study was conducted for BTK assessment; BTK expression was assessed on healthy patients samples and MBCN samples. For evaluation of Ki-67 a cross-sectional study was conducted. Samples were stained with CD45 FITC and CD19 APC for identification of B-cell lymphocytes. After lysis of red blood cells, cytoplasmic staining of BTK PE and/or Ki-67 PerCP-Cy5.5 was performed. Percentage of expression and mean fluorescence intensity (MFI) of the markers were determined in B-cell lymphocytes. Statistical analysis was performed with Pearson and Spearman correlation tests between BTK and Ki-67 and the other clinical and laboratory variables, and ANOVA followed by post-hoc Bonferroni test for comparisons between groups. Results were considered significant when P < 0.05. Results: no differences in BTK expression were identified and there was no association between BTK expression and clinical variables evaluated. Ki-67 expression was higher in mantle cell lymphoma, Burkitt lymphoma and diffuse large B-cell lymphoma cases; after multivariate analysis, MFI of Ki-67 was associated with MFI of CD38. Conclusions: in this study, BTK expression in B-cell neoplasms was similar to that of normal B-cell lymphocytes and Ki-67 expression was higher in MBCN with more aggressive clinical courses.

Base teórica: doenças linfoproliferativas crônicas de linhagem B (DLPC-B) são neoplasias clonais que afetam linfócitos B maduros. A tirosina quinase de Bruton (do inglês Bruton’s tyrosine kinase, BTK) é uma proteína essencial para o desenvolvimento, diferenciação e sinalização nos linfócitos B. Ki-67 é uma proteína nuclear associada à proliferação celular. A avaliação de proteínas envolvidas nas vias de sinalização oncogênicas pode levar ao aprimoramento do diagnóstico, tratamento e definição de prognóstico das DLPC-B. Objetivo: avaliar a expressão de BTK e Ki-67 em linfócitos de portadores de DLPC-B. Métodos: para avaliação de BTK foi realizado um estudo transversal; foi avaliada a expressão de BTK em amostras de pacientes saudáveis e de pacientes com diagnóstico de DLPC-B. Para avaliação de Ki-67 foi realizado um estudo transversal. As amostras foram marcadas com CD45 FITC e CD19 APC para identificação dos linfócitos B. Após a lise das hemácias, foi realizada marcação citoplasmática de BTK PE e/ou Ki-67 PerCP-Cy5.5. O percentual de expressão e a intensidade de fluorescência média (IFM) dos marcadores avaliados foram determinados nos linfócitos B. A análise estatística foi realizada com testes de correlação de Pearson e Spearman entre BTK ou Ki-67 e as demais variáveis clínicas e laboratoriais, e ANOVA seguido por teste post hoc de Bonferroni para comparações entre grupos. Foi considerado resultado significante quando P < 0,05. Resultados: não foram observadas diferenças na expressão de BTK e não houve associação entre a expressão de BTK e as variáveis clínicas avaliadas. A expressão de Ki-67 foi maior nos grupos linfoma do manto, linfoma de Burkitt e linfoma difuso de grandes células B em relação aos demais; após análise multivariada, a IFM de Ki-67 foi associada à IFM de CD38. Conclusão: no presente trabalho, a expressão de BTK em DLPC-B foi similar a de linfócitos B normais e a expressão de Ki-67 foi maior nas DLPC-B com curso clínico mais agressivo. / Background: mature B-cell neoplasms (MBCN) are clonal neoplasms that affect mature B-cell lymphocytes. Bruton’s tyrosine kinase (BTK) is an essential protein for the development, differentiation and signaling in B-cell lymphocytes. Ki-67 is a nuclear protein associated to cellular proliferation. Evaluation of proteins involved in oncogenic signaling pathways can lead to improvement in the diagnosis, treatment and prognosis definition in MBCN. Objective: to evaluate the expression of BTK and Ki-67 in lymphocytes of MBCN patients using flow cytometry. Methods: a cross-sectional study was conducted for BTK assessment; BTK expression was assessed on healthy patients samples and MBCN samples. For evaluation of Ki-67 a cross-sectional study was conducted. Samples were stained with CD45 FITC and CD19 APC for identification of B-cell lymphocytes. After lysis of red blood cells, cytoplasmic staining of BTK PE and/or Ki-67 PerCP-Cy5.5 was performed. Percentage of expression and mean fluorescence intensity (MFI) of the markers were determined in B-cell lymphocytes. Statistical analysis was performed with Pearson and Spearman correlation tests between BTK and Ki-67 and the other clinical and laboratory variables, and ANOVA followed by post-hoc Bonferroni test for comparisons between groups. Results were considered significant when P < 0.05. Results: no differences in BTK expression were identified and there was no association between BTK expression and clinical variables evaluated. Ki-67 expression was higher in mantle cell lymphoma, Burkitt lymphoma and diffuse large B-cell lymphoma cases; after multivariate analysis, MFI of Ki-67 was associated with MFI of CD38. Conclusions: in this study, BTK expression in B-cell neoplasms was similar to that of normal B-cell lymphocytes and Ki-67 expression was higher in MBCN with more aggressive clinical courses.