Cyclophosphamide modulated the foreign body inflammatory reaction in tilapia (Oreochromis niloticus)

Innate immunity response of zafirlukast treated-tilapia during foreign body inflammation

There is limited knowledge regarding the blockade of cysteinyl leukotriene receptors (CysLTRs) and their effects in teleost fish. The present study investigated the effects of Zafirlukast, antagonist of CysLTR1 receptor, on the foreign body inflammatory reaction in Nile tilapia (Oreochromis niloticus). Zafirlukast-treated tilapia demonstrated a decrease in the formation of multinucleated foreign body giant cells and Langhans cells on the round glass coverslips implanted in the subcutaneous tissue, along with a significant reduction in white blood cell counts and decreased production of reactive oxygen species. There was an increase in serum levels of α2-macroglobulins, as well as a decrease in ceruloplasmin and haptoglobin. Zafirlukast treatment led to a significant decrease in the area of splenic melanomacrophage centers and a reduction in the presence of lipofuscin. These findings highlight the potential anti-inflammatory effects of zafirlukast treatment in tilapia and indicate its action on CysLTR1 receptor, modulating the innate immune response of tilapia during the foreign body reaction. The comprehension of chronic inflammation mechanisms in fish has become increasingly relevant, especially concerning the utilization of biomaterials for vaccine and drug delivery.

Antagonism of cysteinyl leukotriene receptors by zafirlukast modulated acute inflammatory reaction in tilapia, Oreochromis niloticus

To identify activation pathways and effector mechanisms of innate immunity in fish has become relevant for the sanitary management of intensive fish farming. However, little is known about the blocking of cysteinyl leukotrienes receptors (CysLTRs) and their effects in teleost fish. Our study evaluated the anti-inflammatory effect of 250 and 500 μg zafirlukast (antagonist of CysLTRs)/kg b.w., administered orally in the diet, during acute inflammatory reaction induced by Aeromonas hydrophila bacterins in Oreochromis niloticus. 80 tilapia were distributed in 10 aquariums (100L of water each, n = 8) to constitute three treatments: Control (inoculated with A. hydrophila bacterin and untreated); Treated with 250 μg or 500 μg of zafirlukast/kg b.w. and inoculated. To be evaluated in three periods: 6, 24 and 48 h post-inoculation (HPI), totaling nine aquariums. A tenth group was sampled without any stimulus to constitute reference values (Physiological standards). Tilapia treated with zafirlukast demonstrated dose-response effect in the decrease of accumulated inflammatory cells, strongly influenced by granulocytes and macrophages. Zafirlukast treated-tilapia showed decrease in blood leukocyte counts (mainly neutrophils, and monocytes) and reactive oxygen species production. Treatment with zafirlukast resulted in down-regulation of ceruloplasmin, complement 3, alpha2-macroglobulin, transferrin and apolipoprotein A1, as well as up-regulation of haptoglobin. Our study provided convincing results in the pathophysiology of tilapia inflammatory reaction, considering that treatment with zafirlukast, antagonist of cysteinyl leukotriene receptors, resulted in a dose-response effect by suppressing the dynamics between leukocytes in the bloodstream and cell accumulation in the inflamed focus, as well as modulated the leukocyte oxidative burst and the acute phase protein response.

Low dosage use of cyclophosphamide improves the survival of patients with systemic lupus erythematosus

OBJECTIVE

To investigate the effect of cyclophosphamide (CYC) on organ involvement and SLE patients' overall and cause-specific mortality.

METHODS

Information about CYC prescription was taken from the Jiangsu Lupus database, which was set up to collect medical records from SLE patients since their first admission during 1999-2009 in Jiangsu province, China. Follow-up studies were carried out in 2010 and 2015 to check the survival status of the patients. Cox regression models were used to estimate the hazard ratio (HR) and 95% CI. Kaplan-Meier model was used to assess the effect of CYC on mortality between organ involvement and non-involvement.

RESULTS

There were 221 deaths observed out of 2446 SLE patients. CYC users decreased overall mortality of SLE (8.4%) with adjusted HR (95% CI) of 0.74 (0.56-0.97), as compared to non-users. A decrease in overall mortality of SLE was found in the low dosage (< 600 mg) of CYC users, with adjusted HR (95% CI) of 0.54 (0.36-0.81). The protection of CYC on mortality of SLE was further observed in subgroups, such as female; SLEDAI score ≥ 15 group; and those with neuropsychiatric, renal, and hematological involvements, and low serum C3. In addition, CYC could eliminate the differences in mortality between organ involvement and non-involvement, including renal, neuropsychiatric, cardiopulmonary, gastrointestinal, and hematological involvement, but not for mucocutaneous and musculoskeletal involvement.

CONCLUSION

Low dosage use of CYC decreased the risk of overall mortality of SLE. CYC might improve the survival of SLE patients with renal, neuropsychiatric, cardiopulmonary, gastrointestinal, and hematological involvements. Key Points • Cyclophosphamide decreases overall mortality of SLE patients. • Decreased mortality is mainly observed from low dosage use of cyclophosphamide. • Cyclophosphamide improves the survival of SLE patients when major systems such as renal, neuropsychiatric, cardiopulmonary, gastrointestinal, and hematological are involved.

Teleost Fish as an Experimental Model for Vaccine Development

Advances in vaccine development depend on animal models to test innovative therapies. Recent studies have reported the successful introduction of teleost fish as a new vertebrate model in scientific research, with emphasis on the species Danio rerio (zebrafish). This chapter aims to give an overview of important aspects related to the immune system of fish, as well as the current progress of the successful use of these animals in studies for the development of vaccines, assisting in the determination of efficacy and clinical safety. Among the advantages of using fish for the development of vaccines and immunomodulatory drugs, it is worth highlighting the reproductive capacity of these animals resulting in a high number of individuals belonging to the same spawning, transparent embryos, low cost of breeding and high genetic similarity that favor translational responses to vertebrate organisms like humans.

Zebrafish as a model to study inflammation: A tool for drug discovery

This study aims to demonstrate the applicability and importance of zebrafish (Danio rerio) model to study acute and chronic inflammatory responses induced by different stimuli: carrageenan phlogogen (nonimmune); acute infection by bacteria (immune); foreign body reaction (chronic inflammation by round glass coverslip implantation); reaction induced by xenotransplantation. In addition to the advantages of presenting low breeding cost, high prolificity, transparent embryos, high number of individuals belonging to the same spawning and high genetic similarity that favor translational responses to vertebrate organisms like humans, zebrafish proved to be an excellent tool, allowing the evaluation of edema formation, accumulation of inflammatory cells in the exudate, mediators, signaling pathways, gene expression and production of specific proteins. Our studies demonstrated the versatility of fish models to investigate the inflammatory response and its pathophysiology, essential for the successful development of studies to discover innovative pharmacological strategies.