RESUMEN
Acute myeloid leukemia (AML) continues to be a deadly disease, with only 50-70% of patients achieving complete remission and less than 30% of adults having sustained long-term remissions. In order to address these unmet medical needs, we carried out a high-throughput screen of an in-house library of on- and off-patent drugs with the OCI/AML-2 cell line. Through this screen, we discovered adefovir dipi-voxil (adefovir-DP) as being active against human AML. In addition to adefovir-DP, there are second-generation formulations of adefovir, including octadecyloxyethyl adefovir (ODE-adefovir) and hexadecyloxypropyl adefovir (HDP-adefovir), which were designed to overcome the pharmacokinetic problems of the parent compound adefovir. Given the known clinical benefit of nucleoside analogs for the treatment of AML, we undertook studies to evaluate the potential benefit of adefovir-based molecules. In AML cell lines and patient samples, adefovir-DP and ODE-adefovir were highly potent, whereas HDP-adefovir was significantly less active. Interestingly, ODE-adefovir was remarkably less toxic than adefovir-DP towards normal hematopoietic cells. In addition, ODE-adefovir at a dose of 15 mg/kg/day showed potent activity against human AML in a NOD/SCID mouse model, with a reduction of human leukemia in mouse bone marrow of > 40% in all mice tested within 20 days of treatment. Based on its chemical structure, we hypothesized that the cytotoxicity of ODE-adefovir toward AML was through cell cycle arrest and DNA damage. Indeed, ODE-adefovir treatment induced cell cycle arrest in the S phase and increased levels of pH2Ax, indicating the induction of DNA damage. Furthermore, there was an increase in phospho-p53, transactivation of proapoptotic genes and activation of the intrinsic apoptotic pathway. Subsequent investigation unveiled strong synergism between ODE-adefovir and ara-C, making their coadministration of potential clinical benefit. Expression of MRP4, a nucleoside transporter, appeared to influence the response of AML cells to ODE-adefovir, as its inhibition potentiated ODE-adefovir killing. Taken together, our findings indicate that clinical development of ODE-adefovir or related compounds for the treatment of AML is warranted.
Asunto(s)
Adenina/análogos & derivados , Apoptosis/efectos de los fármacos , Citarabina/farmacología , Organofosfonatos/farmacología , Adenina/química , Adenina/farmacología , Adenina/uso terapéutico , Animales , Caspasas/metabolismo , Puntos de Control del Ciclo Celular/efectos de los fármacos , Citarabina/uso terapéutico , Daño del ADN/efectos de los fármacos , Composición de Medicamentos , Resistencia a Antineoplásicos , Sinergismo Farmacológico , Femenino , Histonas/metabolismo , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/patología , Ratones , Ratones Endogámicos NOD , Ratones SCID , Organofosfonatos/química , Organofosfonatos/uso terapéutico , Poli(ADP-Ribosa) Polimerasas/metabolismo , Trasplante Heterólogo , Células Tumorales CultivadasRESUMEN
Complement system is a key system for immune surveillance and homeostasis. Excessive activation of complement system,especially the activation of alternative pathway may play a very important role in the pathogenesis of primary and secondary glomerulonephritis. C3 glomerulopathy is a newly named disease characterized by evident C3 deposition in the glomeruli with little or no immunoglobulin under immunofluorescence (IF). Its clinical and pathological manifestations vary a lot. The decreased plasma C3 and Factor H(FH)suggest that abnormal regulation of complement system plays an importment role in its pathogenesis. C3 glomerulopathy varies a lot as to its clinical manifestation, treatment and prognosis. The inhibition of excessive complement activation might be the key to treating C3 glomerulopathy.
Asunto(s)
Activación de Complemento/fisiología , Complemento C3/metabolismo , Vía Alternativa del Complemento/fisiología , Glomerulonefritis/etiología , Vía Alternativa del Complemento/inmunología , Proteínas del Sistema Complemento/inmunología , Glomerulonefritis/clasificación , Glomerulonefritis/inmunología , Humanos , Glomérulos Renales/metabolismo , Glomérulos Renales/patologíaRESUMEN
OBJECTIVE: To analyze the characteristics of repeated renal biopsy-proven primary focal segmental glomerulosclerosis (PFSGS) in 8 children, and to reveal the relationship between clinical features and pathology, between the two times of renal biopsy pathology, and the indications for repeated renal biopsy. METHOD: The records of cases who ever experienced renal biopsy in this hospital were reviewed, of whom 8 cases of repeated renal biopsy-proven PFSGS were enrolled. The clinical manifestations, the reason why they had renal biopsy again, the difference in renal pathological findings, between the two biopsies and their therapeutic response. The classification of focal segmental glomerulosclerosis (FSGS) was based on the new criteria suggested by D'Agati in 2004. RESULT: Of the 8 cases, age of onset ranged from 1 to 12 years, all were diagnosed as nephrotic syndrome (NS), the age of first biopsy ranged from 1.1 to 15.0 years, and the follow-up period was 10 months to 14 years. The reason for repeated biopsy was poor therapeutic response, continuous heavy proteinuria, or the progressive renal dysfunction. Four cases had the both biopsies in this hospital, and the first renal pathology showed minimal change disease (MCD), mesangial proliferation, FSGS CELL type and FSGS GTL type. After the second biopsy, they were additionally treated with immunosuppressive agents or switched to another one, 2 cases with FSGS COLL type presented renal dysfunction or end stage renal disease (ESRD), 1 case who developed the disease at 1.4 years of age, presented renal dysfunction at 10 months follow-up. The remaining 5 cases acquired complete remission. CONCLUSION: FSGS is a clinicopathological syndrome, NS predominates clinically. It often indicates pathologic transformation when the patients show poor therapeutic response or continuous heavy proteinuria without remission. Mesangial proliferation can convert into FSGS, and the subtype of FSGS can shift. FSGS COLL type and onset at young age may suggest poor prognosis.
Asunto(s)
Biopsia , Glomeruloesclerosis Focal y Segmentaria/patología , Riñón/patología , Niño , Preescolar , Femenino , Humanos , Lactante , MasculinoRESUMEN
OBJECTIVE: To study the characteristics of clinicopathology and prognosis of 3 pediatric cases diagnosed as C3 glomerulopathy, and to improve the understanding of C3 glomerulopathy in children. METHOD: The medical record, plasma complement C3, Factor H (FH) and its autoantibody, and therapeutic response of the 3 cases were analyzed, and their prognosis were followed up. RESULT: Of the 3 cases, 2 were male and 1 was female, the age of onset was 9 years, 12 years, 5 years 4 months, the duration from onset to renal biopsy was 3 months, 7 months and 20 days, and the follow-up period were 2.6 years, 8 months and 1.5 years respectively. CLINICAL MANIFESTATIONS: All the 3 cases showed microscopic hematuria, with or without gross hematuria and proteinuria. Two showed persistently decreased plasma complement C3, in the other one C3 was in normal lower limit, all presented with decreased FH concertration, in 1 case anti-FH antibody was positive. Their clinical diagnosis was post-streptococcal glomerulonephritis, nephrotic syndrome (NS) nephritis type, and mesangial proliferative glomerulonephritis respectively. PATHOLOGICAL FINDINGS: All showed evident deposition of C3 on glomerular basement membrance (GBM) and mesangial region by immunofluorescence (IF) and electron dense deposit in GBM, mesangial region or para-mesangial region by Electron microscopic (EM) examination Treatment and prognosis: The case with NS showed no response to steroid, so steroid was gradually stopped after renal biopsy and replaced by angiotensin converting enzyme inhibitors (ACEI) and angiotensin receptor antagonist (ARB). The other two cases were treated with ACEI and renal protective treatment. Of the 3 cases, one gradually showed elevated serum creatinine (Scr) and decreased creatinine clearance rate (Ccr), the other two were normal, but slightly increased indications for early kidney injury. CONCLUSION: C3 glomerulopathy is characterized by evident C3 deposition under IF. Its clinical and pathological manifestations vary a lot. The decreased plasma C3 and FH suggest that the abnormal regulation of complement system play an importment role in its pathogenesis.
Asunto(s)
Complemento C3/metabolismo , Factor H de Complemento/metabolismo , Glomerulonefritis/patología , Glomérulos Renales/metabolismo , Antagonistas de Receptores de Angiotensina/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Niño , Preescolar , Factor H de Complemento/deficiencia , Femenino , Técnica del Anticuerpo Fluorescente , Glomerulonefritis/complicaciones , Glomerulonefritis/tratamiento farmacológico , Glomerulonefritis/metabolismo , Hematuria/etiología , Hematuria/patología , Humanos , Glomérulos Renales/patología , Masculino , Síndrome Nefrótico/etiología , Síndrome Nefrótico/patología , Proteinuria/etiología , Proteinuria/patologíaRESUMEN
BACKGROUND: Patients sustaining major trauma are predisposed to the development of organ dysfunction. We have shown that oxidant stress generated by hemorrhagic shock/resuscitation (S/R) in rodents increases lipopolysaccharide (LPS)-induced lung injury and translocation of nuclear factor kappa B (NF-kappaB) in alveolar macrophages (AMs). In addition, using a cellular model, we have shown that priming with oxidants reprograms LPS signaling through an Src-dependent pathway. In the present studies, we hypothesize that oxidant priming by S/R in vivo involves Src family kinases. METHODS: Rats were bled to a mean arterial pressure of 40 mmHg and maintained for 1 hour, then resuscitated with shed blood and equal volume of Ringer's lactate. In some studies, animals received the antioxidant NAC (0.5 g/kg) or a Src family inhibitor, PP2 (0.1 or 0.2 mg/kg), before resuscitation. LPS was given intratracheally (30 mg/kg) for 4 hours. AMs were lavaged, and total cell counts were determined. AMs were also obtained at end resuscitation and exposed to LPS (0.1 microg/mL) from 0 to 60 minutes. Activation of Hck, an Src family kinase, was analyzed by Western blot using a phosphospecific antibody. Nuclear extracts were obtained to examine NF-kappaB translocation. RESULTS: S/R caused a rise in Src family activity compared with sham animals as shown by the phosphorylation of Hck. This was prevented by treating the animals during resuscitation with NAC. The LPS-induced NF-kappaB translocation in AMs after shock/resuscitation was 3-fold higher than in sham AMs treated with LPS. This augmented translocation was prevented by pretreating the animals with PP2 before resuscitation. In a parallel fashion, PP2 pretreatment reduced the absolute lung neutrophil sequestration. CONCLUSION: Oxidant stress generated during S/R in vivo causes Src family kinase activation in AMs. Inhibition of Src activation by PP2 attenuates AM priming for increased LPS responsiveness after hemorrhagic shock and causes a modest reduction in lung injury. Inhibition of the Src family kinases may be a novel approach for the treatment of lung injury after trauma.
Asunto(s)
Estrés Oxidativo , Síndrome de Dificultad Respiratoria/etiología , Familia-src Quinasas/fisiología , Animales , Lipopolisacáridos/toxicidad , Masculino , FN-kappa B/metabolismo , Neutrófilos/fisiología , Fosforilación , Transporte de Proteínas , Pirimidinas/farmacología , Ratas , Ratas Sprague-Dawley , Choque Hemorrágico/enzimología , Tirosina/metabolismoRESUMEN
OBJECTIVE: To evaluate novel indications for the use of human albumin solutions in the prevention and treatment of acute lung injury following shock/resuscitation and to test the hypothesis that 25% human albumin is an effective resuscitation fluid as well as an immunomodulatory agent protective against lung injury in our model. DESIGN: A previously developed rodent model of acute lung injury in which resuscitated shock primes for increased lung injury in response to a small dose of intratracheal lipopolysaccharide. SETTING: University-affiliated hospital. SUBJECTS: Sprague Dawley rats weighing 300-350 g. INTERVENTIONS: Animals were bled to a mean arterial pressure of 40 mm Hg and maintained in a shock phase for 1 hr. Animals then were resuscitated by transfusion of the shed blood plus an equal volume of Ringer's lactate or their shed blood plus 3 mL/kg volume of 25% albumin or their shed blood plus 15 mL/kg of 5% human albumin over a period of 2 hrs. To test for the possible role of 25% albumin as an antioxidant, we also performed resuscitation with Ringer's lactate supplemented with N-acetylcysteine or 25% albumin depleted of its antioxidant properties by N-ethylmaleimide. Mean arterial pressure was monitored continuously. One hour after resuscitation, 100 microg of lipopolysaccharide in 200 microL of saline was administered intratracheally. MEASUREMENTS AND MAIN RESULTS: Resuscitation with 25% albumin significantly reduced transpulmonary protein flux, bronchoalveolar lavage fluid neutrophil counts, and the degree of histopathological injury compared with resuscitation with Ringer's lactate or 5% albumin. To delineate the underlying mechanism of this beneficial effect, the production of cytokine-induced neutrophil chemoattractant as well as nuclear translocation of its critical transcription factor nuclear factor-kappaB was measured. Both cytokine-induced neutrophil chemoattractant messenger RNA concentrations and nuclear factor-kappaB translocation were diminished following 25% albumin resuscitation. Furthermore, 25% albumin significantly decreased lipid peroxidation in plasma as measured by 8-isoprostane concentrations. N-ethylmaleimide modified 25% albumin, possessing lesser antioxidant activity, exhibited an attenuated protection from lung injury. CONCLUSIONS: Resuscitation with 25% albumin attenuates lung injury in this rat model. The beneficial effect was due to reduced neutrophil sequestration. The antioxidant properties of the 25% albumin preparation appeared to be partially responsible for the effects observed. These studies suggest a novel role for 25% albumin as an anti-inflammatory agent in neutrophil-mediated diseases, such as acute respiratory distress syndrome.