Diflovidazin damages the hematopoietic stem cells to zebrafish embryos via the TLR4/ NF-κB/ p53 pathway

Exposure to environmental contaminants frequently induces the occurrence of blood diseases, but the underlying molecular mechanisms are scarcely known. The toxicity of Diflovidazin (DFD), a widely used mite-remover, to the blood system of non-target organisms requires urgent elucidation. To investigate the deleterious effects of DFD (2, 2.5, and 3 mg/L) on the development and survive of hematopoietic stem cells (HSCs), the zebrafish model was used in this study. DFD exposure reduced the number of HSCs and their subtypes, including macrophages, neutrophils, thymus T-cells, erythrocytes, and platelets. The significant changes in the abnormal apoptosis and differentiation of HSCs were the major reasons for the reduction in blood cells. Using small-molecule antagonists and p53 morpholino revealed that the NF-κB/p53 pathway was responsible for the apoptosis of HSCs upon DFD exposure. The restoration results attributed to the TLR4 inhibitor and molecular docking showed that the TLR4 protein, which was upstream of NF-κB signaling, played a vital role in DFD toxicology. This study elucidates the role and molecular mechanism of DFD in damaging zebrafish HSCs. It provides a theoretical basis for the occurrence of various blood diseases in zebrafish and other organisms.

[Acquired haemophilia A: two cases]

BACKGROUND

Acquired haemophilia A (AH) is an uncommon bleeding disorder that presents as multiple, disseminated spontaneous subcutaneous bleeds. Diagnosis may be made on the basis of prolonged activated partial thromboplastin time (aPTT). The severity of the disease is associated with the low risk of haemoglobin levels and with potential links with other diseases.

OBSERVATIONS

Two men were hospitalized for extensive and spontaneous subcutaneous hematoma. In both cases, the International Normalized Ratio (INR) was normal, but aPTT was 3 times higher than normal. Autoantibodies against coagulation factor VIII confirmed the diagnosis of AH. The patients received immunomodulatory treatment. In one patient, diffuse large B-cell lymphoma was discovered one year after successful treatment of AH.

DISCUSSION

AH may be revealed by areas of bruising, subutaneous haematomas mimicking erythema nodosum, and muscle pain. APTT results alone can prompt the biologist to screen for factor VIII inhibitors. Aside from the risk of fatal bleeding, in half of all cases, the prognosis is determined by associated disorders such as blood dyscrasias, solid tumours, autoimmune diseases, use of certain medicines and pregnancy. After treatment for bleeding complications, therapy focuses on restoring the coagulation time. The aim of immunomodulatory therapy is to stem production of autoantibodies against coagulation factor VIII.

CONCLUSION

AH must be considered rapidly in order to reduce the risk of bleeding emergencies and to screen for potential related diseases.