RESUMO
We recently identified elevated annexin A6 (AnxA6) protein levels in Niemann-Pick-type C1 (NPC1) mutant cells. In these cells, AnxA6 depletion rescued the cholesterol accumulation associated with NPC1 deficiency. Here, we demonstrate that elevated AnxA6 protein levels in NPC1 mutants or upon pharmacological NPC1 inhibition, using U18666A, were not due to upregulated AnxA6 mRNA expression, but caused by defects in AnxA6 protein degradation. Two KFERQ-motifs are believed to target AnxA6 to lysosomes for chaperone-mediated autophagy (CMA), and we hypothesized that the cholesterol accumulation in endolysosomes (LE/Lys) triggered by the NPC1 inhibition could interfere with the CMA pathway. Therefore, AnxA6 protein amounts and cholesterol levels in the LE/Lys (LE-Chol) compartment were analyzed in NPC1 mutant cells ectopically expressing lysosome-associated membrane protein 2A (Lamp2A), which is well known to induce the CMA pathway. Strikingly, AnxA6 protein amounts were strongly decreased and coincided with significantly reduced LE-Chol levels in NPC1 mutant cells upon Lamp2A overexpression. Therefore, these findings suggest Lamp2A-mediated restoration of CMA in NPC1 mutant cells to lower LE-Chol levels with concomitant lysosomal AnxA6 degradation. Collectively, we propose CMA to permit a feedback loop between AnxA6 and cholesterol levels in LE/Lys, encompassing a novel mechanism for regulating cholesterol homeostasis in NPC1 disease.
Assuntos
Anexina A6/metabolismo , Colesterol/metabolismo , Endossomos/metabolismo , Retroalimentação Fisiológica , Peptídeos e Proteínas de Sinalização Intracelular/genética , Lisossomos/metabolismo , Mutação/genética , Proteólise , Animais , Células CHO , Cricetulus , Endossomos/ultraestrutura , Proteínas de Fluorescência Verde/metabolismo , Humanos , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Lisossomos/ultraestrutura , Modelos Biológicos , Proteína C1 de Niemann-PickRESUMO
IMPORTANCE: Given the infrequent occurrence of hydroxychloroquine toxic effects, few data are available about the presenting features and long-term follow-up of patients with hydroxychloroquine retinopathy, making it difficult to surmise the clinical course of patients after cessation of drug treatment. OBJECTIVE: To report functional and structural findings of hydroxychloroquine retinal toxic effects after drug therapy discontinuation. DESIGN: A retrospective medical record review was performed to identify patients taking hydroxychloroquine who were screened for toxic effects from January 1, 2009, through August 31, 2012, in the eye centers of Northwestern University and the University of Southern California. SETTING: Northwestern University Sorrel Rosin Eye Center, Chicago, Illinois, and the Doheny Eye Institute at the University of Southern California, Los Angeles. PARTICIPANTS: Seven consecutive patients diagnosed as having hydroxychloroquine retinal toxic effects. MAIN OUTCOME AND MEASURE: Retinal toxic effects. RESULTS: Seven patients (1 man and 6 women) with a mean age of 55.9 years (age range, 25-74 years) developed retinal toxic effects after using hydroxychloroquine for a mean of 10.4 years (range, 3-19 years). Fundus examination revealed macular pigmentary changes in all 7 patients, corresponding to abnormal fundus autofluorescence (FAF). On spectral domain optical coherence tomography, there was outer retinal foveal resistance (preservation of the external limiting membrane and the photoreceptor layer) in 6 patients. After drug therapy discontinuation, 5 patients experienced outer retinal regeneration (3 subfoveally and 2 parafoveally), with associated functional visual improvement on static perimetry in 2 patients. Over time, FAF remained stable in 3 patients, whereas the remaining patients had a pattern of hypoautofluorescence that replaced areas of initial hyperautofluorescence (2 patients) and enlargement of the total area of abnormal FAF (2 patients). CONCLUSIONS AND RELEVANCE: Preservation of the external limiting membrane carries a positive prognostic value in hydroxychloroquine toxic effects because it may be associated with regeneration of the photoreceptor layer and with potential functional visual improvement on static perimetry. The patterns of abnormal FAF persist despite cessation of the medication, with enlargement of the total area of abnormal FAF being the hallmark of severe toxic effects. Relative foveal resistance in hydroxychloroquine toxic effects was supported by this case series. These findings emphasize the importance of early detection and the need for correlating clinical observations with multimodal imaging, particularly FAF and spectral domain optical coherence tomography.
Assuntos
Antirreumáticos/efeitos adversos , Hidroxicloroquina/efeitos adversos , Imagem Multimodal , Retina/patologia , Doenças Retinianas/diagnóstico , Suspensão de Tratamento , Adulto , Idoso , Artrite Reumatoide/tratamento farmacológico , Progressão da Doença , Feminino , Angiofluoresceinografia , Seguimentos , Humanos , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Retina/efeitos dos fármacos , Retina/fisiopatologia , Doenças Retinianas/induzido quimicamente , Doenças Retinianas/fisiopatologia , Estudos Retrospectivos , Tomografia de Coerência Óptica , Acuidade Visual/fisiologia , Testes de Campo Visual , Campos Visuais/fisiologiaRESUMO
PURPOSE: The purpose of the study was to determine the effectiveness of megestrol acetate (MA) and olanzapine (OLN) for the treatment of cancer-related anorexia (CRA). METHODS: Eighty adult patients with advanced gastrointestinal cancer or lung cancer (stages III and IV) with CRA (loss of appetite and greater than or equal to 5% loss of preillness stable weight) were randomized to receive daily MA or MA plus OLN for a period of 8 weeks. Patients were assessed weekly using the M.D. Anderson Symptom Inventory with specific measurement of weight, appetite, nausea, and quality of life (QOL) measures. RESULTS: For the 37 patients receiving MA, 15 patients had a greater than or equal to 5% weight gain, 2 patients had an appetite improvement, 3 patients had an improvement in nausea, and 5 patients had an improvement in QOL at both 4 and 8 weeks. For the 39 patients receiving MA plus OLN, 33 patients had a greater than or equal to 5% weight gain, 25 patients had an appetite improvement, 21 patients had an improvement in nausea, and 23 patients had an improvement in QOL at both 4 and 8 weeks, and there was an improvement in general activity, mood, work, walking, and enjoyment at 8 weeks. There were no grade III or IV treatment-related toxicities in patients receiving MA or the combination of MA plus OLN. CONCLUSIONS: The combination of MA and OLN appears to be an effective intervention for patients with CRA.
Assuntos
Anorexia/tratamento farmacológico , Estimulantes do Apetite/uso terapêutico , Benzodiazepinas/uso terapêutico , Acetato de Megestrol/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anorexia/etiologia , Apetite/efeitos dos fármacos , Estimulantes do Apetite/administração & dosagem , Benzodiazepinas/administração & dosagem , Peso Corporal/efeitos dos fármacos , Quimioterapia Combinada , Feminino , Neoplasias Gastrointestinais/complicações , Humanos , Neoplasias Pulmonares/complicações , Masculino , Acetato de Megestrol/administração & dosagem , Pessoa de Meia-Idade , Náusea/induzido quimicamente , Estadiamento de Neoplasias , Olanzapina , Qualidade de Vida , Inibidores Seletivos de Recaptação de Serotonina/administração & dosagem , Inibidores Seletivos de Recaptação de Serotonina/uso terapêuticoRESUMO
BACKGROUND: Studies have shown that there is a high prevalence of depression in cancer patients. Women with breast cancer may have an even higher risk of depression particularly in a postmenopausal or estrogen deficiency state. A small number of randomized controlled trials have examined the efficacy of antidepressants compared to that of a placebo in cancer patients, but some results have been difficult to interpret due to a heterogeneous patient group. In the current investigation, we screened newly diagnosed early stage breast cancer patients for depressive symptoms prior to the initiation of adjuvant therapy and investigated whether the oral antidepressant fluoxetine affected depressive symptoms, completion of adjuvant treatment, and quality of life. METHODS: Patients with newly diagnosed early stage breast cancer were screened for depressive symptoms prior to the initiation of adjuvant therapy. Patients with depressive symptoms were randomized to a daily oral fluoxetine or a placebo. Patients were then followed for 6 months and evaluated for quality of life, completion of adjuvant treatment, and depressive symptoms. RESULTS: A high percentage of patients with newly diagnosed early stage breast cancer were found to have depressive symptoms prior to the initiation of adjuvant therapy. The use of fluoxetine for 6 months resulted in an improvement in quality of life, a higher completion of adjuvant treatment (chemotherapy, hormonal therapy, chemotherapy plus hormonal therapy), and a reduction in depressive symptoms compared to patients who received placebo. CONCLUSIONS: An antidepressant should be considered for early stage breast cancer patients with depressive symptoms who are receiving adjuvant treatment.