Ferroptosis-inducing agents compromise in vitro human islet viability and function

Abstract

Human islet transplantation has been hampered by donor cell death associated with the islet preparation procedure before transplantation. Regulated necrosis pathways are biochemically and morphologically distinct from apoptosis. Recently, ferroptosis was identified as a non-apoptotic form of iron-dependent regulated necrosis implicated in various pathological conditions. Mediators of islet oxidative stress, including glutathione peroxidase-4 (GPX4), have been identified as inhibitors of ferroptosis, and mechanisms that affect GPX4 function can impact islet function and viability. Ferroptosis has not been investigated directly in human islets, and its relevance in islet transplantation remains unknown. Herein, we sought to determine whether in vitro human islet viability and function is compromised in the presence of two distinct ferroptosis-inducing agents (FIA), erastin or RSL3, and whether these effects could be rescued with ferroptosis inhibitors, ferrostatin-1 (Fer-1), or desferrioxamine (DFO). Viability, as assessed by lactate dehydrogenase (LDH) release, revealed significant death in erastin- and RSL3-treated islets, 20.3% ± 3.8 and 24.4% ± 2.5, 24 h post culture, respectively. These effects were ameliorated in islets pre-treated with Fer-1 or the iron chelator, desferrioxamine (DFO). Stimulation index, a marker of islet function revealed a significant reduction in function in erastin-treated islets (control 1.97 ± 0.13 vs. 50 μM erastin 1.32 ± 0.1) (p < 0.05). Fer-1 and DFO pre-treatment alone did not augment islet viability or function. Pre-treatment of islets with erastin or Fer-1 did not impact in vivo engraftment in an immunodeficient mouse transplant model. Our data reveal that islets are indeed susceptible to ferroptosis in vitro, and induction of this novel cell death modality leads to compromised islet function, which can be recoverable in the presence of the ferroptosis inhibitors. The in vivo impact of this pathway in islet transplantation remains elusive given the constraints of our study, but warrants continued investigation.

Diverse compounds from pleuromutilin lead to a thioredoxin inhibitor and inducer of ferroptosis

“…Depletion of the glutathione antioxidant system and pharmacological inhibition or degradation of glutathione peroxidase 4 (GPX4) are the main known systems that control ferroptosis. 40,41,43,44,51,64 In contrast, the collected data suggest that ferroptocide targets a different antioxidant system (thioredoxin) to induce ferroptosis; it is likely that inhibition of thioredoxin causes a drastic imbalance in the ROS levels, overwhelms cellular antioxidant responses (as seen at the transcript level), and causes ferroptosis. This hypothesis is supported by genetic knockdown studies of thioredoxin, which lead to accumulation of large amounts of ROS, lipid ROS and sensitization of siTXN cells to ferroptocide treatment.…”

Ferroptosis: past, present and future

“…The induction of ferroptosis leads to impaired islet function, while ferroptosis inhibitors restores islet function. This provides an experimental basis for human islet transplantation and the treatment of type one diabetes 83 . In addition, ferroptosis has been found to play a regulatory role in the progression of the diseases, such as acute myeloid leukemia 84 , age-related macular degeneration (AMD) 85 , psoriasis 86 , and hemolytic disorders 87 .…”

Inhibitory Effect and Mechanism of Action of Quercetin and Quercetin Diels-Alder anti-Dimer on Erastin-Induced Ferroptosis in Bone Marrow-Derived Mesenchymal Stem Cells

“…Therefore, using the lactate dehydrogenase (LDH) release assay, the quercetin and QDAD groups were found to decrease cellular death ( Figure 5A) and increase cellular viability ( Figure 5B). Based on these cellular assays and previous findings [9,65], it can be summarized that both quercetin and QDAD showed a ferroptosis-inhibitory effect; however, quercetin was more effective than QDAD. This can be partly supported by previous findings indicating that quercetin inhibits oxidative stress in neuronal [12][13][14] and other cells [15].…”

“…On the other hand, the negative modulation of ferroptosis can inhibit cellular death to improve the feasibility of transplantation application to treat ferroptosis-related diseases, e.g., Parkinson's disease [6][7][8]. As a result, discovering novel ferroptosis inhibitors has become a hot pursuit in cell biology and chemical biology [8,9].…”