Ferroptosis is essential for diabetic cardiomyopathy and is prevented by sulforaphane via AMPK/NRF2 pathways

Herein, we define the role of ferroptosis in the pathogenesis of diabetic cardiomyopathy (DCM) by examining the expression of key regulators of ferroptosis in mice with DCM and a new ex vivo DCM model. Advanced glycation end-products (AGEs), an important pathogenic factor of DCM, were found to induce ferroptosis in engineered cardiac tissues (ECTs), as reflected through increased levels of Ptgs2 and lipid peroxides and decreased ferritin and SLC7A11 levels. Typical morphological changes of ferroptosis in cardiomyocytes were observed using transmission electron microscopy. Inhibition of ferroptosis with ferrostatin-1 and deferoxamine prevented AGE-induced ECT remodeling and dysfunction. Ferroptosis was also evidenced in the heart of type 2 diabetic mice with DCM. Inhibition of ferroptosis by liproxstatin-1 prevented the development of diastolic dysfunction at 3 months after the onset of diabetes. Nuclear factor erythroid 2-related factor 2 (NRF2) activated by sulforaphane inhibited cardiac cell ferroptosis in both AGE-treated ECTs and hearts of DCM mice by upregulating ferritin and SLC7A11 levels. The protective effect of sulforaphane on ferroptosis was AMP-activated protein kinase (AMPK)-dependent. These findings suggest that ferroptosis plays an essential role in the pathogenesis of DCM; sulforaphane prevents ferroptosis and associated pathogenesis via AMPK-mediated NRF2 activation. This suggests a feasible therapeutic approach with sulforaphane to clinically prevent ferroptosis and DCM.

Frequencies of cytotoxic T lymphocyte precursor estimate in three different populations.

There is speculation that high cytotoxic T lymphocyte precursor frequencies (CTLpf) correlate with poor clinical outcome of bone marrow/organ transplantation. It is also believed that human umbilical cord blood is immunologically naive, and, therefore cord blood T cells may be less able to mediate graft versus host disease than marrow-derived T cells. CTLpf were determined in peripheral blood mononuclear cells collected from healthy adults, human umbilical cord blood and renal dialysis patients who were randomly selected and entered into this study. A highly sensitive non-radioactive Europium release cytotoxicity assay was optimized and modified to carry out the CTLpf estimation by using the principle of limiting dilution analysis. The results of CTLpf in healthy adults ranged from 1/694 to 1/66,666, median 1/7,339 (n=10); cord blood ranged from 1/1,562 to 1/35,714, median 1/10,162 (n=6) and dialysis patients ranged from 1/1,054 to 1/17,857 median 1/5,208 (n=9). The results demonstrated that there is little difference of CTLpf median values between the groups, but there is a wide variation of CTLpf between individuals within a population. It suggests that this variation should be taken into account when considering CTLpf assay as pre-transplantation cross-match procedure.