The cellular mechanism of antipsychotic-induced myocarditis: A systematic review.

Antipsychotic drug-induced myocarditis is a serious and potentially fatal adverse drug reaction characterized by inflammation of the heart muscle (myocardium) that typically develops within the first month after commencing an antipsychotic drug. Although the precise mechanism of this severe adverse drug reaction is unknown, multiple theories have been proposed with varying levels of support from cellular or animal studies. We conducted a systematic review, in accordance with PRISMA guidelines, of published preclinical and clinical studies investigating the cellular mechanism by which antipsychotic drugs induce myocarditis. A literature search including all studies available before December 10, 2022, yielded 15 studies that met our inclusion criteria. Antipsychotics examined in the included studies included clozapine (n = 13), ziprasidone (n = 1), amisulpride (n = 1), haloperidol (n = 1), levomepromazine (n = 1), olanzapine (n = 1), and sertindole (n = 1). The evidence suggests several overlapping mechanistic cascades involving: (1) increased levels of catecholamines, (2) increased proinflammatory cytokines, (3) increased reactive oxygen species (ROS), (4) reduced antioxidant levels and activity, and (5) mitochondrial damage. Notable limitations such as, a focus on clozapine, sample heterogeneity, and use of supratherapeutic doses will need to be addressed in future studies. Discovery of the mechanism by which antipsychotic drugs induce myocarditis will allow the development of clinically-useful biomarkers to identify those patients at increased risk prior to drug exposure. The development or repurposing of therapeutics to prevent or treat drug-induced myocarditis will also be possible and this will enable increased and safe use of antipsychotics for those patients in need.

Generation of two human induced pluripotent stem cell lines from peripheral blood mononuclear cells of clozapine-tolerant and clozapine-induced myocarditis patients with treatment-resistant schizophrenia.

Clozapine has superior efficacy in the treatment of refractory schizophrenia; however, use of clozapine is limited due to severe side effects, including myocarditis. Using non-integrative Sendai virus, we generated induced pluripotent stem cell lines from peripheral blood mononuclear cells of two patients with refractory schizophrenia, one clozapine-tolerant and one clozapine-induced myocarditis. Both cell lines exhibited a normal karyotype and pluripotency was validated by flow cytometry, immunofluorescence and their ability to differentiate into the three germ layers. These lines can be used to generate 2D and 3D patient-specific human cellular models to identify the mechanism by which clozapine induces myocardial inflammation.

Cancer-Associated Fibroblasts Regulate the Plasticity of Breast Cancer Stemness through the Production of Leukemia Inhibitory Factor.

Leukemia inhibitory factor (LIF), as a member of the interleukin-6 cytokine family, plays a complex role in solid tumors. However, the effect of LIF as a tumor microenvironment factor on plasticity control in breast cancer remains largely unknown. In this study, an in vitro investigation is conducted to determine the crosstalk between breast cancer cells and fibroblasts. Based on the results, cancer-associated fibroblasts are producers of LIF in the cocultivation system with breast cancer cells. Treatment with the CAF-CM and human LIF protein significantly promoted stemness through the dedifferentiation process and regaining of stem-cell-like properties. In addition, the results indicate that activation of LIFR signaling in breast cancer cells in the existence of CAF-secreted LIF can induce Nanog and Oct4 expression and increase breast cancer stem cell markers CD24-/CD44+. In contrast, suppression of the LIF receptor by human LIF receptor inhibition antibody decreased the cancer stem cell markers. We found that LIF was frequently overexpressed by CAFs and that LIF expression is necessary for dedifferentiation of breast cancer cell phenotype and regaining of cancer stem cell properties. Our results suggest that targeting LIF/LIFR signaling might be a potent therapeutic strategy for breast cancer and the prevention of tumor recurrence.