Antinociceptive and anti-inflammatory activities of Hymenaea martiana Hayne (Fabaceae) in mice / Atividade antinociceptiva e anti inflamatória de Hymenaea martiana Hayne (Fabaceae) em camundongos

Hymenaea martiana is a species popularly known in Northeastern Brazil as "jatobá" and used in folk medicine to treat pain and inflammation. The aim of this work was to evaluate the antinociceptive and anti-inflammatory activity of H. martiana. In the present study, we carried out an investigation about the effects of the crude ethanolic extract (Hm-EtOH) and the ethyl acetate fraction (Hm-AcOEt) in models of nociception and inflammation in mice. Chemical (acetic acid-induced writhing and formalin) and thermal stimuli (hot plate) were used for the evaluation of antinociceptive activity, while for the anti-inflammatory profile paw edema induced by carrageenan was used, along with leukocyte migration to the peritoneal cavity. The presence of the flavonoid astilbin in the samples was characterized through HPLC-DAD-MS analysis. Hm-EtOH and Hm-AcOEt (100, 200 and 400 mg.kg-¹, i.p.) significantly reduced the number of abdominal contortions and decreased the paw licking time in the formalin test. In the hot plate, the extract increased the latency time of animals. Hm-EtOH and Hm-AcOEt inhibited significantly the increase in the edema after the administration of carrageenan. Hm-EtOH and Hm-AcOEt inhibited leukocyte migration in the peritonitis test. HPLC-DAD-MS analysis of Hm-EtOH and Hm-AcOEt revealed the presence of the flavonoid astilbin in the samples. According to the results of this study, both Hm-EtOH and Hm-AcOEt have antinociceptive and anti-inflammatory activities, which could be related with the presence of flavonoid in the extracts. The results reinforce the popular use of this plant.

Hymenaea martiana é uma espécie popularmente conhecida no Nordeste do Brasil como “jatobᔠe usada na medicina popular para tratar a dor e a inflamação. O objetivo deste trabalho foi avaliar a atividade antinociceptiva e anti inflamatória de H. martiana. No presente estudo, foram avaliados os efeitos do extrato etanólico bruto (Hm-EtOH) e da fração acetato de etila (Hm-AcOEt) em modelos de nocicepção e inflamação em camundongos. Foram utilizados estímulos químicos (contorções abdominais induzidas por ácido acético e teste da formalina) e estímulo térmico (teste da placa quente) para avaliação da atividade antinociceptiva, enquanto no perfil anti-inflamatório foi utilizado o teste do edema de pata induzido por carragenina e migração de leucócitos para a cavidade peritoneal. A presença do flavonoide astilbina nas amostras foi caracterizada através de análise por CLAE-DAD-EM. Hm-EtOH e o Hm-AcOEt (100, 200 e 400 mg.kg-¹, i.p.) reduziram significativamente o número de contorções abdominais e diminuíram o tempo de lambida da pata no teste da formalina. No teste da placa quente, houve aumento do tempo de latência dos animais. Hm-EtOH e Hm-AcOEt inibiram significativamente o aumento do edema após a administração de carragenina, bem como inibiram a migração de leucócitos no teste de peritonite. A análise por CLAE-DAD-EM de Hm-EtOH e Hm-AcOEt revelou a presença do flavonoide astilbina nas amostras. De acordo com os resultados deste estudo, tanto Hm-EtOH quanto o Hm-AcOEt possuem atividades antinociceptiva e anti-inflamatória, o que pode estar relacionado à presença do flavonoide. Os resultados reforçam o uso popular desta planta.

Antinociceptive and anti-inflammatory activities of Hymenaea martiana Hayne (Fabaceae) in mice

Abstract Hymenaea martiana is a species popularly known in Northeastern Brazil as jatobá and used in folk medicine to treat pain and inflammation. The aim of this work was to evaluate the antinociceptive and anti-inflammatory activity of H. martiana. In the present study, we carried out an investigation about the effects of the crude ethanolic extract (Hm-EtOH) and the ethyl acetate fraction (Hm-AcOEt) in models of nociception and inflammation in mice. Chemical (acetic acid-induced writhing and formalin) and thermal stimuli (hot plate) were used for the evaluation of antinociceptive activity, while for the anti-inflammatory profile paw edema induced by carrageenan was used, along with leukocyte migration to the peritoneal cavity. The presence of the flavonoid astilbin in the samples was characterized through HPLC-DAD-MS analysis. Hm-EtOH and Hm-AcOEt (100, 200 and 400 mg.kg-1, i.p.) significantly reduced the number of abdominal contortions and decreased the paw licking time in the formalin test. In the hot plate, the extract increased the latency time of animals. Hm-EtOH and Hm-AcOEt inhibited significantly the increase in the edema after the administration of carrageenan. Hm-EtOH and Hm-AcOEt inhibited leukocyte migration in the peritonitis test. HPLC-DAD-MS analysis of Hm-EtOH and Hm-AcOEt revealed the presence of the flavonoid astilbin in the samples. According to the results of this study, both Hm-EtOH and Hm-AcOEt have antinociceptive and anti-inflammatory activities, which could be related with the presence of flavonoid in the extracts. The results reinforce the popular use of this plant.

Resumo Hymenaea martiana é uma espécie popularmente conhecida no Nordeste do Brasil como jatobá e usada na medicina popular para tratar a dor e a inflamação. O objetivo deste trabalho foi avaliar a atividade antinociceptiva e anti-inflamatória de H. martiana. No presente estudo, foram avaliados os efeitos do extrato etanólico bruto (Hm-EtOH) e da fração acetato de etila (Hm-AcOEt) em modelos de nocicepção e inflamação em camundongos. Foram utilizados estímulos químicos (contorções abdominais induzidas por ácido acético e teste da formalina) e estímulo térmico (teste da placa quente) para avaliação da atividade antinociceptiva, enquanto no perfil anti-inflamatório foi utilizado o teste do edema de pata induzido por carragenina e migração de leucócitos para a cavidade peritoneal. A presença do flavonoide astilbina nas amostras foi caracterizada através de análise por CLAE-DAD-EM. Hm-EtOH e o Hm-AcOEt (100, 200 e 400 mg.kg-1, i.p.) reduziram significativamente o número de contorções abdominais e diminuíram o tempo de lambida da pata no teste da formalina. No teste da placa quente, houve aumento do tempo de latência dos animais. Hm-EtOH e Hm-AcOEt inibiram significativamente o aumento do edema após a administração de carragenina, bem como inibiram a migração de leucócitos no teste de peritonite. A análise por CLAE-DAD-EM de Hm-EtOH e Hm-AcOEt revelou a presença do flavonoide astilbina nas amostras. De acordo com os resultados deste estudo, tanto Hm-EtOH quanto o Hm-AcOEt possuem atividades antinociceptiva e anti-inflamatória, o que pode estar relacionado à presença do flavonoide. Os resultados reforçam o uso popular desta planta.

Antinociceptive and anti-inflammatory activities of Hymenaea martiana Hayne (Fabaceae) in mice / Atividade antinociceptiva e anti-inflamatória de Hymenaea martiana Hayne (Fabaceae) em camundongos

Hymenaea martiana is a species popularly known in Northeastern Brazil as "jatobá" and used in folk medicine to treat pain and inflammation. The aim of this work was to evaluate the antinociceptive and anti-inflammatory activity of H. martiana. In the present study, we carried out an investigation about the effects of the crude ethanolic extract (Hm-EtOH) and the ethyl acetate fraction (Hm-AcOEt) in models of nociception and inflammation in mice. Chemical (acetic acid-induced writhing and formalin) and thermal stimuli (hot plate) were used for the evaluation of antinociceptive activity, while for the anti-inflammatory profile paw edema induced by carrageenan was used, along with leukocyte migration to the peritoneal cavity. The presence of the flavonoid astilbin in the samples was characterized through HPLC-DAD-MS analysis. Hm-EtOH and Hm-AcOEt (100, 200 and 400 mg.kg-1, i.p.) significantly reduced the number of abdominal contortions and decreased the paw licking time in the formalin test. In the hot plate, the extract increased the latency time of animals. Hm-EtOH and Hm-AcOEt inhibited significantly the increase in the edema after the administration of carrageenan. Hm-EtOH and Hm-AcOEt inhibited leukocyte migration in the peritonitis test. HPLC-DAD-MS analysis of Hm-EtOH and Hm-AcOEt revealed the presence of the flavonoid astilbin in the samples. According to the results of this study, both Hm-EtOH and Hm-AcOEt have antinociceptive and anti-inflammatory activities, which could be related with the presence of flavonoid in the extracts. The results reinforce the popular use of this plant.

Hymenaea martiana é uma espécie popularmente conhecida no Nordeste do Brasil como "jatobá" e usada na medicina popular para tratar a dor e a inflamação. O objetivo deste trabalho foi avaliar a atividade antinociceptiva e antiinflamatória de H. martiana. No presente estudo, foram avaliados os efeitos do extrato etanólico bruto (Hm-EtOH) e da fração acetato de etila (Hm-AcOEt) em modelos de nocicepção e inflamação em camundongos. Foram utilizados estímulos químicos (contorções abdominais induzidas por ácido acético e teste da formalina) e estímulo térmico (teste da placa quente) para avaliação da atividade antinociceptiva, enquanto no perfil anti-inflamatório foi utilizado o teste do edema de pata induzido por carragenina e migração de leucócitos para a cavidade peritoneal. A presença do flavonoide astilbina nas amostras foi caracterizada através de análise por CLAE-DAD-EM. Hm-EtOH e o Hm-AcOEt (100, 200 e 400 mg.kg-1, i.p.) reduziram significativamente o número de contorções abdominais e diminuíram o tempo de lambida da pata no teste da formalina. No teste da placa quente, houve aumento do tempo de latência dos animais. Hm-EtOH e Hm-AcOEt inibiram significativamente o aumento do edema após a administração de carragenina, bem como inibiram a migração de leucócitos no teste de peritonite. A análise por CLAE-DAD-EM de Hm-EtOH e Hm-AcOEt revelou a presença do flavonoide astilbina nas amostras. De acordo com os resultados deste estudo, tanto Hm-EtOH quanto o Hm-AcOEt possuem atividades antinociceptiva e anti-inflamatória, o que pode estar relacionado à presença do flavonoide. Os resultados reforçam o uso popular desta planta.

Antinociceptive and anti-inflammatory activities of Hymenaea martiana Hayne (Fabaceae) in mice.

Hymenaea martiana is a species popularly known in Northeastern Brazil as "jatobá" and used in folk medicine to treat pain and inflammation. The aim of this work was to evaluate the antinociceptive and anti-inflammatory activity of H. martiana. In the present study, we carried out an investigation about the effects of the crude ethanolic extract (Hm-EtOH) and the ethyl acetate fraction (Hm-AcOEt) in models of nociception and inflammation in mice. Chemical (acetic acid-induced writhing and formalin) and thermal stimuli (hot plate) were used for the evaluation of antinociceptive activity, while for the anti-inflammatory profile paw edema induced by carrageenan was used, along with leukocyte migration to the peritoneal cavity. The presence of the flavonoid astilbin in the samples was characterized through HPLC-DAD-MS analysis. Hm-EtOH and Hm-AcOEt (100, 200 and 400 mg.kg-1, i.p.) significantly reduced the number of abdominal contortions and decreased the paw licking time in the formalin test. In the hot plate, the extract increased the latency time of animals. Hm-EtOH and Hm-AcOEt inhibited significantly the increase in the edema after the administration of carrageenan. Hm-EtOH and Hm-AcOEt inhibited leukocyte migration in the peritonitis test. HPLC-DAD-MS analysis of Hm-EtOH and Hm-AcOEt revealed the presence of the flavonoid astilbin in the samples. According to the results of this study, both Hm-EtOH and Hm-AcOEt have antinociceptive and anti-inflammatory activities, which could be related with the presence of flavonoid in the extracts. The results reinforce the popular use of this plant.

The role of interleukins in vitiligo: a systematic review.

Vitiligo is a disorder of the skin that causes depigmentation and asymptomatic macules whose exact cause is still unclear. Although its aetiology is not fully elucidated, the main theory of its pathomechanism is that it is associated with the autoimmune process. There is few summarized information about the role of inflammatory mediators, as interleukins, in vitiligo, so our aim was to present a systematic review of the role of interleukins in vitiligo, focusing on interleukins. In this review, we included all studies assessing interleukin levels in vitiligo patients conducted up to June 2017. Quality assessment of these studies was performed using the Newcastle-Ottawa Scale (NOS). The interleukins mainly involved were IL-2, IL-4, IL-6, IL-10 and IL-17. The studies highlight the crucial role of IL-17 in the onset and progression of the disease, and its synergistic action with IL-2, IL-6 and IL-33. Dysregulated levels of the interleukins were also correlated with the stage of disease, the affected skin surface area, and indicated as the main factor for lymphocyte infiltration found in depigmented regions. These findings illustrate the growing need for new therapies targeting vitiligo and further research into the role of interleukins as an area of particular interest.

Antinociceptive, anti-inflammatory and antioxidant activities of aqueous extract from Remirea maritima (Cyperaceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Remirea maritima Aubl., popularly known as "capim-da-praia", is popularly employed in the treatment of diarrhea, kidney disease, fever, and for analgesic and anti-inflammatory purposes through the preparation of teas. Few studies have focused on the chemical composition and its biological properties. AIM OF THE STUDY: This work evaluated the antinocipetive, anti-inflammatory and antioxidant activities of the aqueous extract from Remirea maritima Aubl. as well as the isolation and identification of the chemical compounds. MATERIALS AND METHODS: Compounds were isolated from aqueous extract of Remirea maritima through preparative HPLC and the structures were identified by means of NMR and MS analysis. The tests for antinociceptive, anti-inflammatory, and antioxidant activities, along with motor coordination test (Rota rod), were performed over the aqueous extract. RESULTS: The phytochemical investigation of aqueous extract of Remirea maritima resulted in the isolation of three flavone glycosides. The structures of these compounds were determined by means of MS and 1D and 2D NMR data as vitexin-2″-O-ß-D-glucopyranoside, isovitexin-2″-O-ß-D-glucopyranoside, and luteolin-7-O-glucuronide. Acute pretreatment with aqueous extract (100, 200 or 400mg/kg, i.p.) caused a significant decrease (p<0.001) in the number of abdominal writhes. In the formalin test, higher doses significantly inhibited the late (inflammatory pain) phase of formalin-induced licking (p<0.05 or 0.001). In the hot plate test, there was no significant difference in nociceptive behavior, discarding the possible central effect of the aqueous extract. In the rota rod test, it was verified that the aqueous extract in all concentration evaluated does not alter the motor coordination of mice, such antinociceptive results were unlikely to be caused by motor abnormality. In the peritonitis test, induced by carrageenan, the treatment with aqueous extract produced a significant reduction in leukocyte migration in all concentration evaluated. Additionally, a significant reduction of lipoperoxidation (TBARS test) and in nitric oxide formation (.NO Scavenging assay) was observed in antioxidant activity assay. CONCLUSION: The biological and phytochemical investigations of the aqueous extract of Remirea maritima resulted in the identification of three flavone glycosides that have been described here for the first time in Remirea and effective analgesic activity in various pain models, probably mediated via the inhibition of peripheral mediators which could be related to its strong antioxidant effect observed in vitro.

Efecto de la costoplastia en la función pulmonar y la estética en pacientes con escoliosis idiopática del adolescente / Effect of thoracoplasty on pulmonary function and esthetics in patients with adolescent idiopathic scoliosis

Objetivo: Evaluar en pacientes con escoliosis idiopática del adolescente, intervenidos mediante artrodesis vertebral posterior y costoplastia, la función pulmonar y los resultados clínicos y funcionales. Material y método: Evaluamos prospectivamente a 18 pacientes consecutivas con escoliosis idiopática del adolescente con componente torácico, a las que se les realizó artrodesis vertebral posterior instrumentada con costoplastia asociada, con un seguimiento de 2 años. La función pulmonar se valoró por medio de la capacidad vital forzada (CVF) y el volumen espiratorio máximo en el primer segundo (VEM1) en la espirometría basal preoperatoria, al año y a los 2 años postoperatorios. Para la evaluación clínica y funcional se utilizó el cuestionario SRS-22, preoperatorio y a los 2 años de la cirugía. Resultados: La CVF preoperatoria media fue de 2,63 l (77,15% del valor teórico), mientras que el VEM1 medio fue de 2,29 l (79,46% del valor teórico). Los valores medios al año postoperatorio fueron de 2,77 l para la CVF y de 2,48 l para el VEM1 (un 79,8 y un 85,2% de los valores teóricos, respectivamente). A los 2 años postoperatorios, el valor medio de la CVF fue de 2,86 l y del VEM1 de 2,64 l, es decir, un 81,8 y un 89,15% de los valores teóricos, respectivamente. Resultó muy significativa la mejoría en la percepción de la autoimagen del paciente tras la cirugía. Conclusiones: Las pruebas funcionales respiratorias demuestran que los pacientes escolióticos intervenidos experimentaron una mejoría significativa y progresiva de la función respiratoria con respecto al control basal prequirúrgico (AU)

Purpose: To evaluate pulmonary function and clinical and functional outcomes in patients with adolescent idiopathic scoliosis (AIS) treated with posterior spinal fusion and thoracoplasty. Materials and methods: We evaluated prospectively 18 consecutive patients with thoracic AIS treated with instrumented posterior spinal fusion with concomitant thoracoplasty with a 2 years follow-up. Pulmonary function was assessed by forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) before surgery, and one and two years after surgery. We used the SRS-22 questionnaire to assess the clinical outcomes before surgery and two years after surgery. Results: Average absolute preoperative FVC was 2.63 L (theoretical predictive value FVC:77.15%) while FEV1 was 2.29 (theoretical predictive value FEV1:79.46%). At one year postsurgery, mean values of FVC and FEV1 were, respectively, 2.77 and 2.48 (theoretical predictive value FVC: 79.8% and FEV1:85.2%). At two years postsurgery, mean value of FVC was 2.86 L and 2.64L for FVC and FEV1 respectively, that is, FVC: 81.8%, and FEV1:89.15%. The improvement in the self-image item of the patients after surgery on the SRS-22 questionnaire is very significant. Conclusions: The pulmonary function tests show that these scoliotic patients have a significant progressive improvement of FVC and FEV1 at one and two years postsurgery, compared with the preoperative values (AU)

Down-regulation of ceramide production abrogates ionizing radiation-induced cytochrome c release and apoptosis.

Previous work has demonstrated that down-regulation of ceramide production after selection of cells with N-oleoylethanolamine (OE), an inhibitor of ceramidase, results in resistance to DNA damage-induced apoptosis. We report here that acute exposure of WEHI-231 cells (murine B-cell lymphoma) to OE activates neutral sphingomyelinase, induces ceramide production and increases intracellular reactive oxygen species. OE exposure also induces mitochondrial permeability, cytochrome c release, and apoptosis. Cells selected for resistance to OE exhibit little if any change in reactive oxygen species and cytochrome c release when exposed either to OE or to toxic doses of ceramide. Importantly, the OE resistant cells are also resistant to ionizing radiation-induced cytochrome c release and apoptosis. These findings demonstrate that down-regulation of neutral sphingomyelinase activity is associated with decreased DNA-damage-induced apoptosis. In addition, the data suggests that agents that modify extranuclear targets responsible for ceramide production select for cells resistant to ionizing radiation-induced apoptosis through alterations in mitochondrial function.

[Combined perioperative ultrafiltration in pediatric cardiac surgery. The preliminary results]. / Ultrafiltración combinada perioperatoria en cirugía cardíaca pediátrica. Resultados preliminares.

INTRODUCTION AND OBJECTIVES: Recently, ultrafiltration techniques are used more and more as a treatment for the inflammatory response of cardiopulmonary bypass. It also provides fine control of fluids. The purpose of this study is to present a technique which combines conventional and modified ultrafiltration and to analyze the obtained results. PATIENTS AND METHODS: 22 patients (mean weight 13.1 +/- 8.4 kg) operated on cardiopulmonary bypass. Combined ultrafiltration was performed during cardiopulmonary bypass (conventional) and after pump (modified ultrafiltration). We analyzed cardiopulmonary bypass variables, the first 24-hour hemodynamics, biological variables (arterial blood gases, cell counts, IL-6, adhesion molecules ICAM-1 and VCAM-1, and coagulation profiles). RESULTS: A total amount of 1,399 +/- 680 ml/m2 of mean combined ultrafiltrate volume was obtained (657 +/- 386 ml/m2 during cardiopulmonary bypass and 845 +/- 358 ml/m2 post-cardiopulmonary bypass). After modified ultrafiltration, hematocrit rose from 23 +/- 2.3 to 32 +/- 4.1, arterial systolic blood pressure rose from 74 +/- 13 to 98 +/- 20 mmHg, heart rate decreased from 133 +/- 22 to 126 +/- 23 bpm, and central versus pressure did not change. A statistically significant relationship (multivariable), was shown between modified ultrafiltration time and VCAM-1 post-ultrafiltration levels. Platelet count was lower and diuresis rose related to cardiopulmonary bypass ultrafiltration volume and diuresis increased. CONCLUSIONS: Perioperative combined ultrafiltration is feasible without undue morbidity and provides adequate hemoconcentration and excellent postoperative hemodynamic results. More studies with control groups are necessary to better define the therapeutic influence in antiinflammatory properties of this technique.

Decreasing the apoptotic threshold of tumor cells through protein kinase C inhibition and sphingomyelinase activation increases tumor killing by ionizing radiation.

Approximately 30% of cancer deaths result from the failure to control local and regional tumors. The goal of radiotherapy is to maximize local and regional tumor cell killing while minimizing normal tissue destruction. Attempts to enhance radiation-mediated tumor cell killing using halogenated pyrimidines, antimetabolites, and other DNA-damaging agents or sensitizers of hypoxic tumor cells have met with only modest clinical success. In an unique strategy to modify tumor radiosensitivity, we used an inhibitor of the protein kinase C group A and B isoforms, chelerythrine chloride (chelerythrine), to enhance the killing effects of ionizing radiation (IR). Protein kinase C activity plays a central role in cellular proliferation, differentiation, and apoptosis. Chelerythrine increases sphingomyelinase activity and enhances IR-mediated cell killing through induction of apoptotic tumor cell death in a radioresistant tumor model both in vitro and in vivo. Although previous reports have suggested that IR-mediated apoptosis correlates with tumor volume reduction, we demonstrate for the first time that lowering the apoptotic threshold increases tumor cell killing in vivo.

Loss of ceramide production confers resistance to radiation-induced apoptosis.

Ionizing radiation mediates cell death, in part, through chromosomal damage following one or more cell divisions. X-rays also induce programmed cell death (apoptosis) in some cell types both in vitro and in vivo. Both neutral and acidic sphingomyelinases, which generate the lipid second messenger ceramide, are reported to induce apoptosis following ionizing radiation and other death signals such as tumor necrosis factor alpha and Fas ligand. Herein we report that a loss of ceramide production from a neutral sphingomyelinase generates a radioresistant phenotype as measured by a marked decrease in apoptosis. A WEHI-231 subline made deficient in ceramide production was found to be resistant to apoptosis compared with the parental subline following treatment with X-rays. The resistant subline underwent two to three subsequent cell divisions following X-irradiation, confirming that X-rays induce cell death through both mitotic and apoptotic mechanisms. These data suggest that loss of ceramide production following X-rays represents an extranuclear mechanism for the development of radioresistance. Modulation of extranuclear signals may increase tumor cell killing following radiation and represent new cellular targets for cancer therapy.

Anti-immunoglobulin-induced apoptosis in WEHI 231 cells involves the slow formation of ceramide from sphingomyelin and is blocked by bcl-XL.

Prolonged (>24 h) exposure to anti-IgM (an antigen surrogate that induces membrane cross-linking and apoptosis) induced a 3-fold increase in the mass of endogenous ceramide measured by 32P labeling by diacylglycerol kinase and a 4-fold increase in ceramide as measured by metabolic labeling with [3H]palmitate in a B-lymphocyte cell line, WEHI 231. This correlated with the induction of apoptosis. Shorter exposure times to anti-IgM (up to 8 h) failed to elicit apoptosis and did not elicit increased ceramide formation. After 8 h, apoptosis occurs concomitantly with ceramide formation over the next 40 h. Further, we showed that exogenous ceramide mimicked anti-IgM-induced apoptosis and that apoptosis was potentiated in serum-free media. Treatment of cells with an inhibitor of ceramide catabolism, N-oleoylethanolamine, increased both ceramide formation and apoptosis and accelerated apoptosis induced by anti-IgM. To examine further how ceramide metabolism is involved in apoptosis, we derived cell lines from a small population of cells resistant to N-oleoylethanolamine. These cell lines were selected based on an altered ceramide metabolic pathway, were resistant to apoptosis induced by anti-IgM, and showed no significant increase in ceramide when challenged with anti-IgM. The basis of this resistance was shown to be the failure to activate neutral sphingomyelinase activity following 24-h treatment with anti-IgM, in contrast to the 2-fold increase in neutral sphingomyelinase activity observed in wild type cells. We have shown previously that transfection of WEHI cells with bcl-xL conferred resistance to anti-IgM-induced apoptosis, whereas transfection with bcl-2 did not (Gottschalk, A., Boise, L., Thompson, C., and Quintans, J. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 7350-7354). In this study, these bcl-xL transfectants also displayed increased resistance to exogenous N-acetylsphingosine (C2-ceramide) or N-hexanoylsphingosine (C6-ceramide). However, when challenged with anti-IgM the bcl-xL transfectants produced levels of ceramide similar to wild type cells, suggesting that ceramide formation is upstream of bcl-xL and that it is a major determinant of B-cell death.

Effect of extended sleep deprivation on tumor growth in rats.

To assess the effect of chronic sleep deprivation on host defense, we observed growth and regression of a subdermal allogenic carcinoma (Walker 256 rat tumor) in rats undergoing 10 days of total sleep deprivation (TSD rats), yoked stimulus control (TSC) rats that were partially sleep deprived, and home cage control (HCC) rats. Tumor size was measured daily. Integrated tumor size was smaller in TSD rats than in both TSC (P = 0.04) and HCC rats (P = 0.0003). Thus host defense against these tumors (as defined by reduction in tumor size) was improved by sleep deprivation. This improvement could be a nonspecific effect, e.g., tumor growth can be inhibited by a catabolic state (dietary restriction). TSD and TSC rats lost body weight, indicating a catabolic state. However, tumor size was not predicted by body weight change, but was predicted by change in sleep time (P = 0.02). Host defense enhancement could alternatively result from enhanced immune response. Early tumor size (5 days) was similar in the three groups, but peaked sooner in TSD rats than in both TSC (P = 0.05) and HCC rats (P = 0.01), leading to large differences in size later. Immune-suppressed rats also showed little difference from HCC rats in early growth but large differences later. Thus host defense in an in vivo model that manifests a systemic immune response can be enhanced by sleep deprivation with timing, which is consistent with an enhancement of the immune response.

Immunosuppression of thyroiditis.

Immunization of mice with 50 micrograms human thyroglobulin (TG) in complete Freund's adjuvant leads to histological thyroiditis; production of IgG, IgA, and IgM anti-TG antibodies; and in vitro proliferative responses after incubation of lymphocytes with TG. Oral administration of 500 micrograms TG at four intervals before Tg immunization and once afterward causes up to 80% suppression of these responses. The effect is antigen specific and dose dependent. Feeding TG after immunization produces a 40% reduction in responses. We wished to define the mechanism of this antigen-specific oral tolerization. Popliteal lymph nodes (PLN) of orally tolerized animals (T) are reduced in size compared to those in immunized (I) animals not fed TG. PLN and mesenteric lymph nodes (MLN) of I animals produce interleukin-2 (IL-2) and interferon-gamma (IFN gamma) after in vitro incubation with TG, typical of an inflammatory immune response. PLN and MLN of tolerized animals do not proliferate in response to antigen, do not produce IL-2 or IFN gamma, but do not produce the cytokines IL-4 and transforming growth factor-beta (TGF beta). Mixing in vitro of spleen cells from T and I animals causes a reduction in the immune response when incubated with TG, but no reduction in response to purified protein derivative (PPD) (the antigen in complete Freund's adjuvant). When T splenocytes are incubated with TG and PPD together, the response to TG and PPD is suppressed. Partially purified CD8+ cells from tolerized animals produce IL-4 and TGF beta after exposure to human TG and induce suppression, whereas partially purified CD4+ cells produce IL-2 and IFN gamma and do not cause suppression. MLN cells do not proliferate in response to antigen, but do produce inhibitory cytokines. T animals appear to shift the immune response from a Th-1 helper cell subset response to a Th-2 helper cell immunosuppressive response. In this model, oral tolerization produces a dramatic reduction in the immune response. Exposure of MLN to oral TG appears to cause the production of regulatory cells that migrate to spleen and PLN. In vitro studies demonstrate that on exposure to antigen, these regulatory cells produce IL-4 and TGF beta, which suppress all aspects of specific immune responsiveness and nonspecifically suppress other ongoing immune responses (bystander effect). Oral tolerization may include some element of T cell deletion or anergy. This model defines an experimental system with possible relevance to immunosuppression of human autoimmune thyroid disease.

Protein kinase C inhibition induces apoptosis and ceramide production through activation of a neutral sphingomyelinase.

We report that WEHI-231 undergo apoptosis following exposure to the protein kinase C inhibitors chelerythrine chloride and calphostin C. Following the addition of chelerythrine or calphostin C to WEHI-231 cells, ceramide production increased over baseline levels with a concurrent decrease in sphingomyelin. More detailed examinations determined that the ceramide accumulation resulted from activation of neutral, but not acidic, sphingomyelinase. These results suggest an antagonistic relationship between protein kinase C activity and ceramide in the signaling events preceding apoptosis.

The ability of Bcl-x(L) and Bcl-2 to prevent apoptosis can be differentially regulated.

Although expression of Bcl-2 has been shown to prevent apoptosis under many circumstances, there are several systems in which Bcl-2 fails to promote cell survival. We have previously reported that Bcl-2 and Bcl-x(L) display differential ability to protect WEHI-231 cells from multiple inducers of apoptosis. A possible explanation for this paradox was provided by the discovery of Bax. Bax is a Bcl-2-related protein which can inhibit the ability of Bcl-2 to enhance the survival of growth factor-dependent cell lines in the absence of growth factor. Consistent with the possibility that Bcl-2 function in WEHI-231 cells is inhibited by Bax, WEHI-231 cells were found to express a high level of Bax. To directly test the effects of Bax expression on Bcl-x(L) function, FL5.12 cells were transfected with both genes. Although Bax overexpression can inhibit Bcl-2 from prolonging cell survival upon growth factor withdrawal, Bax overexpression did not inhibit Bcl-x(L) from preventing apoptosis in this cell line. Although Bcl-2 and Bcl-x(L) were both found to be able to form heterodimers with Bax, the majority of Bax in both cases was not complexed to a partner. Our data suggest that Bcl-x(L) does not function by simply preventing the formation of Bax homodimers which promote cell death. Instead Bax appears to display selectivity in its ability to inhibit Bcl-2 but not Bcl-x(L) from prolonging survival. Furthermore, our data suggest that the abilities of Bcl-2 and Bcl-x(L) to promote cell survival are not identical and can be independently regulated within a cell. Regulation of a cell's apoptotic threshold is likely to result from a complex set of interactions among Bcl-2 family members and other, as yet uncharacterised, regulators of apoptosis.

Cross-talk between ceramide and PKC activity in the control of apoptosis in WEHI-231.

WEHI-231, a murine B-cell lymphoma, readily undergoes programmed cell death following surface immunoglobulin (Ig) cross-linking [1]. Ceramide has been shown to induce apoptosis in WEHI-231 following its exposure to anti-lg antibodies, dexamethasone, and irradiation [2]. Recently, Haimovitz-Friedman et al. have demonstrated in endothelial cells that PMA not only prevented ceramide mediated apoptosis, but inhibited the generation of ceramide following irradiation [3]. In this paper we use highly specific PKC inhibitors to explore the connection between PKC activity, ceramide signaling and apoptosis. Both chelerythrine chloride and calphostin C triggered rapid apoptosis in WEHI-231 and acted in synergy with exogenous ceramide to induce apoptosis. Detailed studies of chelerythrine's mechanism of action revealed that 30 minutes following addition of 10 microM chelerythrine, sphingomyelin and phosphatidylcholine (PC) mass decreased confirming our previous findings of neutral, but not acidic, sphingomyelinase activation following treatment with PKC inhibitors [4]. The novel observation that inhibition of PKC isoforms present in WEHI-231 leads to a rapid rise in cellular ceramide as a results of sphingomyelin hydrolysis further suggests an antagonistic relationship between PKC activity and ceramide in the signaling events preceding apoptosis.

Suppression of development of experimental autoimmune thyroiditis by oral administration of thyroglobulin.

Experimental autoimmune thyroiditis (EAT), which to some extent represents an experimental model of human chronic lymphocytic thyroiditis, is an organ-specific autoimmune disease characterized by autoantibody production to thyroid antigens (Ag) and mononuclear infiltration of the thyroid gland. EAT induced by immunization with human thyroglobulin (hTG) with Freund's adjuvant in CBA/J (H-2K) mice is associated with prominent B and T cell responses. We report that oral administration of hTG effectively reduces the immune responses in EAT in mice in an Ag-specific manner. Both cellular and humoral immune responses are reduced in a dose-dependent manner. Histological evidence of disease is dramatically reduced. Suppression of the immune responses is seen 2 weeks after Ag challenge, with partial inhibition of proliferative and antibody responses. Six weeks after immunization, further inhibition is observed of both T and B cell responses. Hyporesponsiveness of T and B cell reactivity is seen only to hTG; T and B cell responses to other immunogens are not affected, including purified protein derivative and the nonrelated Ag BSA. This model may provide the basis for immunotherapy of autoimmune thyroid diseases in man.

The role of bcl-XL in CD40-mediated rescue from anti-mu-induced apoptosis in WEHI-231 B lymphoma cells.

The phenotypically immature B cell lymphoma WEHI-231 undergoes apoptotic cell death when cultured with anti-immunoglobulin (Ig) antibodies, via a bcl-2-independent mechanism. We have therefore studied the role of the bcl-2-related protein bcl-x in controlling cell death in WEHI-231. We find that overexpression of the long form of bcl-x (bcl-XL) renders these cells refractory to anti-Ig-induced cell death. Stimulation of WEHI-231 via CD40 has similar protective effects. We show here that ligation of CD40 rapidly induces the appearance of the bcl-XL protein in WEHI-231, while stimulation via sIgM, sIgD, CD5 or CD45 receptors, or with phorbol esters plus ionomycin does not. WEHI-231 cells also rapidly undergo massive apoptosis following culture with thapsigargin, a specific inhibitor of the Ca(2+)-ATPase of the endoplasmic reticulum: this is also reversed by anti-CD40, or by overexpression of bcl-XL. We, therefore, conclude that bcl-XL plays a key role in the regulation of antigen receptor-mediated apoptosis via CD40 in WEHI-231. In addition, the fact that this protein is not induced in WEHI-231 in response to phorbol dibutyrate plus ionomycin points to a fundamental signaling defect in these cells, which could conceivably be a reflection of their immature, apoptosis-susceptible phenotype.

Resistance to anti-IgM-induced apoptosis in a WEHI-231 subline is due to insufficient production of ceramide.

We describe the properties of a physiological cell death (PCD)-resistant subline of WEHI-231 generated from the PCD-susceptible WEHI-231.7 JM cell line maintained in our laboratory. The PCD-resistant WEHI-231.7 JMRE subline was uniquely resistant to anti-immunoglobulin (Ig)M-induced PCD but not to irradiation and etoposide. In these sublines, we compared the expression of genes implicated in regulating PCD. Northern analysis of c-myc, c-fos, egr-1, Fas, p53 and retinoblastoma revealed similar basal levels of expression in all sublines tested and comparable responses to anti-IgM treatment. Similarly, the expression of bcl-2, bcl-x, bax and IL-1 beta converting enzyme did not correlate with susceptibility to anti-IgM-induced PCD. Next, we systematically studied signal transduction events including: tyrosine phosphorylation, Ca++ flux, and ceramide production in the Jm and JMRE sublines. The tyrosine phosphorylation patterns and the Ca++ influx generated following sIgM engagement were very similar in the JM and JMRE sublines. In contrast, the generation of ceramide differed in the PCD-resistant and PCD-susceptible sublines. Ceramide is produced following cross-linking sIgM on WEHI-231.7 JM cells and causes PCD. Ceramide levels in anti-IgM-treated WEHI-231.7 JMRE cells are low and appear to be insufficient to induce PCD.