17β-Estradiol protects mesenchymal stem cells against high glucose-induced mitochondrial oxidants production via Nrf2/Sirt3/MnSOD signaling

Crosstalk between mitochondrial metabolism and oxidoreductive homeostasis: a new perspective for understanding the effects of bioactive dietary compounds

Mitochondria play an important role in a number of fundamental cellular processes, including energy production, biosynthetic pathways and cellular oxidoreductive homeostasis (redox status), and their dysfunction can lead to numerous pathophysiological consequences. As the biochemical mechanisms orchestrating mitochondrial metabolism and redox homeostasis are functionally linked, mitochondria have been identified as a potential therapeutic target. Consequently, considerable effort has been made to evaluate the efficacy of natural compounds that modulate mitochondrial function. Molecules produced by plants (for example, polyphenols and isothiocyanates) have been shown to modulate mitochondrial metabolism/biogenesis and redox status; however, despite the existence of a functional link, few studies have considered the combined efficacy of these mitochondrial functions. The present review provides a complete overview of the molecular pathways involved in modulating mitochondrial metabolism/biogenesis and redox status. Crosstalk between these critical mechanisms is also discussed, whilst major data from the literature regarding their antioxidant abilities are described and critically analysed. We also provide a summary of recent evidence regarding the ability of several plant-derived compounds to target these mitochondrial functions. An in-depth understanding of the functional link between mitochondrial metabolism/biogenesis and redox status could facilitate the analysis of the biological effects of natural compounds as well as the development of new therapeutic approaches.

Octyl itaconate inhibits osteoclastogenesis by suppressing Hrd1 and activating Nrf2 signaling

The endogenous metabolite itaconate has emerged as a regulator of macrophage function that limits inflammation. However, its effect on cell differentiation and osteoclast-related diseases is unclear. Here, for the first time, we explored the effect of itaconate and its cell-permeable itaconate derivative, 4-octyl itaconate (OI) on osteoclast differentiation in vitro and in vivo. Firstly, we demonstrated that itaconate concentration was lower in estrogen-deficient mice. OI released itaconate and induced the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2) in bone marrow-derived macrophages during osteoclastogenesis. Furthermore, OI significantly suppressed the early, middle, and late stages of osteoclastogenesis induced by receptor activator of NF-κB ligand in vitro, as confirmed by tartrate-resistant acid phosphatase staining. Moreover, it significantly inhibited fibrous actin ring formation and bone resorption in vitro. Mechanistically, we observed that OI enhanced Nrf2 expression by suppressing its association with ubiquitin via inhibition of the E3 ubiquitin ligase (Hrd1). OI also inhibited LPS-induced the reactive oxygen species and inflammatory responses via Hrd1. An estrogen deficiency (via ovariectomy)-induced osteoporosis model was also established. Here, on micro-computed tomography and histologic analysis showed that OI effectively suppressed ovariectomy-induced bone loss. In summary, OI, an itaconate derivative, can inhibit osteoclastogenesis in vitro and in vivo, indicating that OI could be a potential drug to treat osteoclast-related diseases; our results also link itaconate to the development of osteoporosis.-Sun, X., Zhang, B., Pan, X., Huang, H., Xie, Z., Ma, Y., Hu, B., Wang, J., Chen, Z., Shi, P. Octyl itaconate inhibits osteoclastogenesis by suppressing Hrd1 and activating Nrf2 signaling.

Effect of aging on behaviour of mesenchymal stem cells

Organs whose source is the mesoderm lineage contain a subpopulation of stem cells that are able to differentiate among mesodermal derivatives (chondrocytes, osteocytes, adipocytes). This subpopulation of adult stem cells, called "mesenchymal stem cells" or "mesenchymal stromal cells (MSCs)", contributes directly to the homeostatic maintenance of their organs; hence, their senescence could be very deleterious for human bodily functions. MSCs are easily isolated and amenable their expansion in vitro because of the research demanding to test them in many diverse clinical indications. All of these works are shown by the rapidly expanding literature that includes many in vivo animal models. We do not have an in-depth understanding of mechanisms that induce cellular senescence, and to further clarify the consequences of the senescence process in MSCs, some hints may be derived from the study of cellular behaviour in vivo and in vitro, autophagy, mitochondrial stress and exosomal activity. In this particular work, we decided to review these biological features in the literature on MSC senescence over the last three years.

Preeclampsia and intrauterine growth restriction: Role of human umbilical cord mesenchymal stem cells-trophoblast cross-talk

Background

Oxidative stress is involved in the pathogenesis and maintenance of pregnancy-related disorders, such as intrauterine growth restriction (IUGR) and preeclampsia (PE). Human umbilical cord mesenchymal stem cells (hUMSCs) have been suggested as a possible therapeutic tool for the treatment of pregnancy-related disorders in view of their paracrine actions on trophoblast cells.

Objectives

To quantify the plasma markers of peroxidation in patients affected by PE and IUGR and to examine the role of oxidative stress in the pathophysiology of PE and IUGR in vitro by using hUMSCs from physiological and pathological pregnancies and a trophoblast cell line (HTR-8/SVneo).

Study design

In pathological and physiological pregnancies the plasma markers of oxidative stress, arterial blood pressure, serum uric acid, 24h proteinuria, weight gain and body mass index (BMI) were examined. Furthermore, the pulsatility index (PI) of uterine and umbilical arteries, and of fetal middle cerebral artery was measured. In vitro, the different responses of hUMSCs, taken from physiological and pathological pregnancies, and of HTR-8/SVneo to pregnancy-related hormones in terms of viability and nitric oxide (NO) release were investigated. In some experiments, the above measurements were performed on co-cultures between HTR-8/SVneo and hUMSCs.

Results

The results obtained have shown that in pathological pregnancies, body mass index, serum acid uric, pulsatility index in uterine and umbilical arteries and markers of oxidative stress were higher than those found in physiological ones. Moreover, in PE and IUGR, a relation was observed between laboratory and clinical findings and the increased levels of oxidative stress. HTR-8/SVneo and hUMSCs showed reduced viability and increased NO production when stressed with H₂O₂. Finally, HTR-8/SVneo cultured in cross-talk with hUMSCs from pathological pregnancies showed a deterioration of cell viability and NO release when treated with pregnancy-related hormones.

Conclusion

Our findings support that hUMSCs taken from patients affected by PE and IUGR have significant features in comparison with those from physiologic pregnancies. Moreover, the cross-talk between hUMSCs and trophoblast cells might be involved in the etiopathology of IUGR and PE secondary to oxidative stress.

MicroRNA-128-3p aggravates doxorubicin-induced liver injury by promoting oxidative stress via targeting Sirtuin-1

As one classic anticancer drug, clinical application of Doxorubicin (Dox) is limited due to its side effects. In our previous work, we have investigated the drug targets to treat Dox-induced cardiotoxicity, hepatotoxicity and nephrotoxicity. In this paper, the mechanisms and new drug-target associated with Dox-induced hepatotoxicity were explored. The results showed that Dox markedly inhibited cell viability and cellular respiration, induced cell morphologic change and increased ROS level. Moreover, Dox increased ALT and AST levels, caused pathological damage, increased MDA level and decreased SOD level in mice. Mechanism investigation showed that Dox markedly up-regulated the expression level of miR-128-3p, down-regulated Sirt1 expression level and affected the protein levels of Nrf2, Keap1, Sirt3, NQO1 and HO-1 to cause oxidative stress in liver. Furthermore, double-luciferase reporter assay, and co-transfection test showed that miR-128-3p directly targeted Sirt1. In addition, miR-128-3p mimics in AML-12 cells enhanced Dox-induced oxidative damage via inhibiting cellular respiration, increasing ROS level and mitochondrial superoxide formation. The protein levels of Sirt1, Nrf2, Sirt3, NQO1 and HO-1 in miR-128-3p mimic + Dox group were decreased compared with Dox group. Transfection of miR-128-3p inhibitor weakened Dox-induced oxidative damage via increasing cellular respiration, suppressing cellular ROS level and mitochondrial superoxide formation. The protein levels of Sirt1, Nrf2, Sirt3, NQO1 and HO-1 in miR-128-3p inhibitor + Dox group were increased compared with Dox group. In mice, Dox-induced liver damage was deteriorated by miR-128-3p agomir via increasing the levels of ALT, AST, MDA, and down-regulating the protein levels of Sirt1, Nrf2, Sirt3, NQO1 and HO-1. While, miR-128-3p antagomir alleviated liver injury via decreasing the levels of ALT, AST, MDA, and up-regulating the protein levels of Sirt1, Nrf2, Sirt3, NQO1 and HO-1. Our data showed that miRNA-128-3p aggravated Dox-induced liver injury by promoting oxidative stress via targeting Sirt1, which should be considered as one new drug target to treat Dox-induced liver injury.

Mitochondrial dysfunction in acute kidney injury and sex-specific implications

The kidney is one of the most energy-demanding organs in the human body, and the maintenance of mitochondrial homeostasis is central to kidney function. Recent advances have led to a greater appreciation of how mitochondrial dysfunction contributes to the pathogenesis of AKI, from decreased ATP production, to enhanced mitochondrial oxidative stress, cell necrosis and apoptosis. Accumulating evidence suggests sexual dimorphism in the response to AKI with males demonstrating greater risk for developing ischemia-reperfusion and sepsis-induced kidney injury. In contrast, females may be more susceptible to nephrotoxic-AKI. There are important sex-related differences in mitochondrial respiration, biogenesis and dynamics that likely contribute to the observed sexual dimorphism in AKI. Sex hormones mediate many of these differences with multiple preclinical studies demonstrating the renoprotective actions of estrogen in many rodent models of AKI. Estrogenic control of mitochondrial biogenesis, function and reactive oxygen species (ROS) generation is discussed. Furthermore, the potential role for sex chromosomes in mediating sex differences in AKI is examined. Novel animal models such as the "four core genotypes" (FCG) mouse model provide us with important tools to study sex chromosome effects in kidney health and disease. By understanding the influences of sexual dimorphism or sex hormones on mitochondrial homeostasis and disease manifestations, we may be able to identify novel therapeutic targets and improve existing treatment options for AKI.