La interleucina-1Beta aumenta la muerte neuronal en el giro dentado del hipocampo asociada al estado epiléptico en la rata en desarrollo / Interleukin-1Beta increases neuronal death in the hippocampal dentate gyrus associated with status epilepticus in the developing rat

Introducción: La interleucina 1β (IL-1Beta) aumenta la muerte neuronal necrótica debido al estado epiléptico (EE) en el área CA1 del hipocampo de ratas en desarrollo; sin embargo, se desconoce si ejerce un efecto similar en el giro dentado (GD) hipocampal. El objetivo de esta investigación fue analizar el efecto de IL-1Beta en la muerte neuronal inducida por el EE en el GD de ratas Wistar de 14 días de edad. Métodos: El EE se indujo con el modelo de litio-pilocarpina. Seis horas después del inicio del EE, la IL-1Beta se inyectó intracerebroventricularmente (0, 0,3, 3, 30 o 300 ng/μl); grupos adicionales se inyectaron con el antagonista natural del receptor tipoi (IL-1RI) de IL-1Beta (IL-1Ra, 30 ng/μl) en ausencia o presencia de IL-1Beta (3 ng/μl). La muerte neuronal se evaluó en la capa granular del GD 24 h después del EE mediante la tinción de hematoxilina-eosina. Las células muertas se caracterizaron por presentar citosol eosinofílico y núcleos condensados y fragmentados. Resultados: Se observó un incremento en el número de células eosinofílicas en el GD ipsilateral a la inyección de 3 y 300 ng/μl de IL-1Beta en comparación con el grupo vehículo; en el GD contralateral se observó un efecto similar únicamente con 3 ng/μl de IL-1Beta. La coadministración de IL-1Beta con el IL-1Ra no evitó el aumento en el número de células eosinofílicas. Conclusión: La IL-1Beta aumenta la muerte neuronal con morfología apoptótica provocada por el EE en el GD del hipocampo, mecanismo independiente de la activación del receptor IL-1RI (AU)

Background: Interleukin-1Beta (IL-1Beta) increases necrotic neuronal cell death in the CA1 area after induced status epilepticus (SE) in developing rats. However, it remains uncertain whether IL-1Beta has a similar effect on the hippocampal dentate gyrus (DG). In this study, we analysed the effects of IL-1Beta on 14-day-old Wistar rats experiencing DG neuronal death induced by SE. Methods: SE was induced with lithium-pilocarpine. Six hours after SE onset, a group of pups was injected with IL-1β (at 0, 0.3, 3, 30, or 300 ng/μL) in the right ventricle; another group was injected with IL-1Beta receptor (IL-1R1) antagonist (IL-1Ra, at 30 ng/μL) of IL-1RI antagonist (IL-1Ra) alone, and additional group with 30 ng/μL of IL-1Ra plus 3 ng/μL of IL-1Beta. Twenty-four hours after SE onset, neuronal cell death in the dentate gyrus of the dorsal hippocampus was assessed using haematoxylin-eosin staining. Dead cells showed eosinophilic cytoplasm and condensed and fragmented nuclei. Results: We observed an increased number of eosinophilic cells in the hippocampal DG ipsilateral to the site of injection of 3ng/μL and 300 ng/μL of IL-1Beta in comparison with the vehicle group. A similar effect was observed in the hippocampal DG contralateral to the site of injection of 3 ng/μL of IL-1Beta. Administration of both of IL-1Beta and IL-1Ra failed to prevent an increase in the number of eosinophilic cells. Conclusion: Our data suggest that IL-1Betaincreases apoptotic neuronal cell death caused by SE in the hippocampal GD, which is a mechanism independent of IL-1RI activation (AU)

Pharmacokinetics and Pharmacodynamics of Canakinumab in Patients With Systemic Juvenile Idiopathic Arthritis.

The characterization of the pharmacokinetic (PK) and pharmacodynamic (PD) properties in pediatric patients is essential in supporting the recommended dosage of canakinumab in the relevant population. Here the PK and PD properties of canakinumab-a monoclonal antibody-in pediatric patients with systemic juvenile idiopathic arthritis (SJIA) are presented. Blood samples were obtained from 4 phase 2/3 clinical studies in patients with SJIA. Canakinumab PK properties and total interleukin (IL)-1ß kinetic properties were characterized by a population-based PK-binding model. On administration, canakinumab increased total IL-1ß complex in SJIA patients. Canakinumab clearance and volume of distribution were not impacted by age in pediatric patients after correction for the patient's body weight. The estimated serum clearance of canakinumab was 0.106 ± 0.00689 L/day, with a corresponding volume of distribution at steady state of 3.2 L and an estimated half-life of 22 days, based on a model typical body weight of 33 kg. Body-weight-based dosing provided comparable canakinumab exposure across the age groups in patients 2 to <20 years with SJIA. In younger children, a modest increase in the turnover rate of IL-1ß was observed. Compared to other indications, IL-1ß production rate was higher and clearance was slower in patients with SJIA. Low immunogenicity incidence of 3.1% was observed, and none of the patients had neutralizing antibodies. In conclusion, the PK/PD findings further support dose selection of canakinumab in patients with SJIA.

Red blood cell ghosts as promising drug carriers to target wound infections.

Autologous red blood cell ghosts (RBC ghosts) can carry cytokines to the sites of inflammation. The targeting moiety of the RBC ghosts is associated with the nature of purulent inflammation, where the erythrocytes are phagocyted and encapsulated drugs are released. In the present study we have investigated the healing potential of RBC ghosts loaded with cytokine IL-1ß and antibiotic. Additionally, the pharmacokinetic properties of RBC ghosts loaded with IL-1ß were studied. 35 Male Wistar rats (250-300g) were used in the pharmacokinetic study and in a wound infection model where a suspension of Staphylococcus aureus was placed into a surgical cut of the skin and subcutaneous tissue in the femoral region. In order to monitor progression of the wound repair processes, wound swabs or aspiration biopsies were taken for analyses on the 1st-6th days. Wound repair dynamics assessment was based on suppression of S. aureus growth, signs of pain, time of disappearance of pus and infiltration around the wound. Visual observations, as well as microbiological and cytological analysis of wound exudates demonstrated a significant acceleration of healing processes in a group of animals treated with a local injection of IL-1ß and ceftriaxone encapsulated into RBC ghosts when compared to the animals treated either with a local or IM injection of free drugs. For the pharmacokinetic study, single IV injections of either free or encapsulated IL-1ß were made and the concentration of IL-1ß in serum samples and tissue homogenates were determined. Encapsulation in RBC ghosts improved pharmacokinetic profiles of IL-1ß by increasing the half-life, reducing its clearance, and increasing the deposition of the drug in the liver, spleen and lungs. These data suggest that RBC ghosts are effective drug carriers for targeted delivery of cytokines to the sites of inflammation, and have a potential for improving the treatment outcomes of purulent diseases.

Tumor-targeting properties of novel immunocytokines based on murine IL1ß and IL6.

There is an increasing biotechnological interest in 'arming' therapeutic antibodies with bioactive payloads. Many antibody-cytokine fusion proteins (immunocytokines) have been described and some of these biopharmaceuticals have progressed to clinical studies. Here, we describe for the first time the expression and in vivo characterization of immunocytokines based on murine IL1ß and IL6. These potent pro-inflammatory cytokines were fused at the N-terminus or at the C-terminus of the monoclonal antibodies F8 (specific to the alternatively-spliced extra-domain A domain of fibronectin, a marker of tumor angiogenesis). All immunocytokines retained the binding properties of the parental antibody and were homogenous, when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and size-exclusion chromatography, except for the N-terminal fusion of IL1ß which revealed the presence of glycosylated species. When analyzed by quantitative biodistribution analysis using radioiodinated protein preparations, F8 fusions with IL6 revealed a preferential accumulation at the tumor site for both cytokine orientations, whereas IL1ß fusions exhibited lower tumor to organ ratios and a slower blood clearance profile. The fusion proteins with the cytokine payload at the C-terminus were studied in therapy experiments in immunocompetent mice bearing F9 tumors. Immunocytokines based on IL1ß resulted in 10% body weight loss at a 5-µg dose, whereas IL6-based products caused a 5% body weight loss at a 225-µg dose. Both F8-IL1ß and F8-IL6 exhibited a <50% inhibition of tumor growth rate, which was substantially lower than the one previously reported for F8-TNF, a closely related pro-inflammatory immunocytokine. This study indicates that IL6 can be efficiently delivered to the tumor neo-vasculature by fusion with the F8 antibody. While F8-IL6 was not as potent as other F8-based immunocytokines that exhibit similar biodistribution profiles, the fusion protein sheds light on the different roles of pro-inflammatory cytokines in boosting immunity against the tumor.

Cloning of the IL-1ß3 gene and IL-1ß4 pseudogene in salmonids uncovers a second type of IL-1ß gene in teleost fish.

To date two closely related interleukin-1ß genes (IL-1ß1 and IL-ß2) have been found in salmonids. The cloning of trout and salmon IL-1ß3, and a salmon IL-1ß4 pseudogene reveals that two types of IL-1ß genes exist in teleost species. Type I teleost IL-1ß genes, including salmonid IL-1ß3, share a similar 6 coding exon structure as in tetrapods. Type II teleost IL-1ß genes, e.g. salmonid IL-1ß1-2, lack one or two coding exons at their 5'-end, and share higher identities within this subgroup than within the type I subgroup. Both types of IL-1ß genes have been found in species of Salmoniformes, Perciformes and Beloniformes, suggesting the divergence occurred early in teleost evolution. Trout IL-1ß3 is highly expressed in ovary suggesting a role in reproduction. A relatively high constitutive expression in gills, spleen and kidney and the up-regulation by PAMPs, proinflammatory cytokines and viral infection suggests IL-1ß3 also has a role in inflammation and host defence.

Ovine proinflammatory cytokines cross the murine blood-brain barrier by a common saturable transport mechanism.

OBJECTIVES: The cytokines interleukin (IL)-1beta and IL-6 are modulators of the neuroimmune axis and have been implicated in neuronal cell death cascades after ischemia or infection. Previous work has shown that some cross-species conservation exists between human and rodent blood-brain barrier (BBB) transport systems. To further assess cross-species conservation of cytokine transport across the BBB, the current studies investigated permeability and inhibition of ovine IL-1beta and IL-6 in the mouse. METHODS: IL-1beta or IL-6 was radioactively labeled with (131)I and injected into the jugular vein at time zero. A subset of mice received 1 or 3 microg/mouse of an unlabeled ovine or murine cytokine (IL-1beta or IL-6) to assess self- and/or cross-inhibition of transport. Permeability was assessed using multiple-regression analysis. RESULTS: There was a significant linear relationship for both ovine (131)I-IL-1beta and (131)I-IL-6 between brain/serum ratios and exposure time, indicating BBB permeability. Inclusion of 3 microg/mouse unlabeled ovine IL-1beta or IL-6 significantly reduced the transport of ovine (131)I-IL-1beta or (131)I-IL-6, respectively, across the BBB. Transport of both ovine (131)I-IL-1beta and (131)I-IL-6 was significantly inhibited by 1 microg/mouse of murine IL-1beta or IL-6, respectively. In contrast, 1 microg/mouse of unlabeled ovine IL-1beta or IL-6 did not inhibit the transport of murine (131)I-IL-1beta or (131)I-IL-6. CONCLUSIONS: Ovine IL-1beta and IL-6 cross the mouse BBB by saturable transport. Inhibition of transport by murine homologs indicates that both species use the same transport mechanisms. Conversely, an inability of ovine cytokines to significantly inhibit the transport of murine cytokines indicates that mouse BBB has a lower affinity for ovine than murine cytokines. Knowledge of species-conserved BBB transport mechanisms may facilitate the development of novel animal models of central nervous system pathogenesis.

Toxicogen¨¦tica del tratamiento antirretroviral (I): lipodistrofia, alteraciones metab¨®licas y arteriosclerosis / Toxicogenetics of antiretroviral treatment (1): Lipodystrophy, metabolic perturbations and atherosclerosis

Entre los efectos adversos del tratamiento antirretroviral, probablemente el m¨¢s trascendente sea la toxicidad metab¨®lica y sobre el tejido adiposo por sus eventuales consecuencias a largo plazo en t¨¦rminos de riesgo cadiovascular. Dado que no todos los pacientes tratados con f¨¢rmacos antirretrovirales la presentan, se ha postulado que debe existir una predisposici¨®n gen¨¦tica. La informaci¨®n actualmente disponible es, a menudo, no concordante. Se ha demostrado de forma consistente que los polimorfismos en los genes que codifican para las apolipoprote¨ªnas A5, C3 y E, para las prote¨ªnas transportadoras de ¨¦steres de colesterol (CETP), y en el cassette de enlace a ATP tipo A1 (ABCA1), modulan la generaci¨®n de la dislipidemia secundaria al tratamiento antirretroviral, especialmente si ¨¦ste contiene inhibidores de la proteasa (IP). En cuanto a los polimorfismos de la prote¨ªna de uni¨®n al elemento regulador de esteroles tipo 1 (SREBP1), no existen evidencias concordantes. En el caso de la redistribuci¨®n de la grasa corporal o lipodistrofia, se ha estudiado si mutaciones en el ADN mitocondrial modulan el riesgo de aparici¨®n, con resultados no concluyentes. Se ha descartado de forma rotunda la existencia de mutaciones en el gen de la lamina. Se han investigado los polimorfismos de genes que codifican para citocinas proinflamatorias, incluyendo el factor de necrosis tumoral alfa (TNF-¦Á), la interleucina 1 beta (IL-1¦Â) y la interleucina 6 (IL-6), con evidencias contradictorias en el caso del TNF-¦Á, negativas en el caso de la IL-6 y datos que sugieren una asociaci¨®n positiva en el caso de la IL-1¦Â. Por otra parte, los polimorfismos en el gen que codifica el factor derivado de c¨¦lulas de la estroma-1 (SDF-1) y la prote¨ªna quimioatractiva de monocitos-1 (MCP-1) se han relacionado con la presencia de arteriosclerosis subcl¨ªnica en pacientes infectados por el VIH-1 que reciben tratamiento antirretroviral(AU)

Among the adverse effects attributed to antiretroviral therapy, one of the most striking is probably the appearance of the lipodystrophy syndrome and its associated metabolic derangements, given its potential long-term effect as a cardiovascular risk factor. Since not all patients who receive antiretroviral drugs experience these adverse effects, a host genetic predisposition has been postulated. However, currently available data on this issue is inconclusive and preliminary. It has been consistently demonstrated that polymorphisms in the genes that encode for apolipoproteins A5, C3 and E, for the cholesterol ester transporter proteins (CETP), and in the ATP binding cassette type A1 (ABCA1) influence the development of dyslipidemia in patients treated with antiretroviral drugs, particularly if the therapeutic regimen includes protease inhibitors. Data on the effect of polymorphisms in the sterol regulatory ester binding protein type 1 (SREBP1) are inconsistent. The effect of mitochondrial DNA mutations on the risk of lipodystrophy has been assessed, with inconclusive data. No polymorphisms in the lamin A gene have been detected. Investigations have assessed the effect of diverse polymorphisms in the genes that encode for several proinflammatory cytokines such as tumour necrosis factor alpha (TNF-¦Á), interleukin-1-beta (IL-1¦Â) and interleukin-6 (IL-6). The results show inconsistent data in the case of TNF-¦Á, no association in the case of IL-6, and preliminary positive associations in IL-1¦Â. In contrast, polymorphisms in the genes encoding for stromal derived factor 1 (SDF-1) and for monocyte chemoattractant protein 1 (MCP-1) have been shown to influence the development of subclinical atherosclerosis in HIV-1-infected patients treated with antiretroviral drugs(AU)