Bioorthogonal microglia-inspired mesenchymal stem cell bioengineering system creates livable niches for enhancing ischemic stroke recovery via the hormesis

Mesenchymal stem cells (MSCs) experience substantial viability issues in the stroke infarct region, limiting their therapeutic efficacy and clinical translation. High levels of deadly reactive oxygen radicals (ROS) and proinflammatory cytokines (PC) in the infarct milieu kill transplanted MSCs, whereas low levels of beneficial ROS and PC stimulate and improve engrafted MSCs' viability. Based on the intrinsic hormesis effects in cellular biology, we built a microglia-inspired MSC bioengineering system to transform detrimental high-level ROS and PC into vitality enhancers for strengthening MSC therapy. This system is achieved by bioorthogonally arming metabolic glycoengineered MSCs with microglial membrane-coated nanoparticles and an antioxidative extracellular protective layer. In this system, extracellular ROS-scavenging and PC-absorbing layers effectively buffer the deleterious effects and establish a micro-livable niche at the level of a single MSC for transplantation. Meanwhile, the infarct's inanimate milieu is transformed at the tissue level into a new living niche to facilitate healing. The engineered MSCs achieved viability five times higher than natural MSCs at seven days after transplantation and exhibited a superior therapeutic effect for stroke recovery up to 28 days. This vitality-augmented system demonstrates the potential to accelerate the clinical translation of MSC treatment and boost stroke recovery.

Multipollutant reciprocal neurological hazard from smoke particulate matter and heavy metals cadmium and lead in brain nerve terminals

Heavy metals, Cd2+ and Pb2+, and carbonaceous air pollution particulate matter are hazardous neurotoxicants. Here, a capability of water-suspended smoke particulate matter preparations obtained from poplar wood (WPs) and polypropylene fibers (medical facemasks) (MPs) to influence Cd2+/Pb2+-induced neurotoxicity, and vice versa, was monitored using biological system, i.e. isolated presynaptic rat cortex nerve terminals. Combined application of Pb2+ and WPs/MPs to nerve terminals in an acute manner revealed that smoke preparations did not change a Pb2+-induced increase in the extracellular levels of excitatory neurotransmitter L-[14C]glutamate and inhibitory one [3H]GABA, thereby demonstrating additive result and no interference of neurotoxic effects of Pb2+ and particulate matter. Whereas, both smoke preparations decreased a Cd2+-induced increase in the extracellular level of L-[14C]glutamate and [3H]GABA in nerve terminals. In fluorimetric measurements, the metals and smoke preparations demonstrated additive effects on the membrane potential of nerve terminals causing membrane depolarisation. WPs/MPs-induced reduction of spontaneous ROS generation was mitigated by Cd2+ and Pb2+. Therefore, a potential variety of multipollutant heavy metal-/airborne particulate-induced effects on key presynaptic processes was revealed. Multipollutant reciprocal neurological hazard through disturbance of the excitation-inhibition balance, membrane potential and ROS generation was evidenced. This multipollutant approach and data contribute to up-to-date environmental quality/health risk estimation.

The effects of ROMO1 on cervical cancer progression

INTRODUCTION

More than 95% of the cases of Cervical cancer (CC) are now linked to infection with Human papilloma virus (HPV) but the infection alone is not sufficient for starting the oncogenesis. Reactive Oxygen Species (ROS) can promote CC cancerogenesis. ROMO1 is a protein that regulates the production of intracellular ROS and influences cancer cell invasion and proliferation. We aimed to investigate the impact of ROS in CC progression, measured by the expression of ROMO1.

METHODS AND MATERIALS

This is a retrospective study of 75 patients treated at the Department of Oncogynecology, Medical University of Pleven, Bulgaria. Paraffin embedded tumor tissues were immunohistochemically tested for the levels of expression of ROMO1. The results for both Allred score and H-score were investigated for association with tumor size, lymph node status and FIGO stage.

RESULTS

Levels of ROMO1 were significantly higher in FIGO1 stage compared to FIGO2 and FIGO3 according to both scores (for H-score FIGO1 vs FIGO2 p = 0.00012; FIGO 1 vs FIGO3 p = 0.0008; for Allred score FIGO1 vs FIGO2, p = 0.0029; FIGO1 vs FIGO3 (p = 0.012). Statistically significant difference was found according to the H-score between patients with and without metastatic lymph nodes (p = 0.033).

CONCLUSION

To the best of our knowledge this is the first study testing immunohistochemically the expression of ROMO1 for CC progression. The levels of ROMO1 were significantly higher in early stage tumors compared to advanced. Bearing in mind that only 75 patients were tested, further studies are required to evaluate the value of ROS in CC.

The mitochondria-targeting antioxidant MitoQ alleviated lipopolysaccharide/ d-galactosamine-induced acute liver injury in mice

The mitochondria are the primary source of reactive oxygen species (ROS) under pathological condition, but the significance of mitochondrial ROS in the development of Lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced acute liver injury remains unclear. In the present study, the level of mitochondrial ROS in LPS/D-Gal has been determined by MitoSox staining and the potential roles of mitochondrial ROS in LPS/D-Gal-induced liver injury have been investigated by using the mitochondria-targeting antioxidant MitoQ. The results indicated that LPS/D-Gal exposure induced the generation of mitochondrial ROS while treatment with MitoQ reduced the level of mitochondrial ROS. Treatment with MitoQ ameliorated LPS/D-Gal-induced histopathologic abnormalities, suppressed the elevation of AST and ALT, and increased the survival rate of the experimental animals. Treatment with MitoQ also suppressed LPS/D-Gal-induced production of tumor necrosis factor α (TNF-α), inhibited the activities of caspase-3, caspase-8 and caspase-9, decreased the level of cleaved caspase-3 and reduced the counts of TUNEL positive cells. These results indicate that mitochondrial ROS is involved in the development of LPS-induced acute liver injury and the mitochondria-targeting antioxidant MitoQ might have potential value for the treatment of inflammation-based acute liver injury.

Expression of CD44 variant 9 induces chemoresistance of gastric cancer by controlling intracellular reactive oxygen spices accumulation

BACKGROUND

CD44 variant 9 (CD44v9) has been reported to suppress reactive oxygen spices (ROS) in association with antioxidant factors such as glutathione (GSH) and glutathione peroxidase 2 (GPx2), resulting in promoted tumor growth.

METHODS

CD44v9 and GPx2 expression were investigated by immunohistochemistry in resected specimens from 193 gastric cancer (GC) patients without preoperative chemotherapy and in pretreatment biopsy specimens from 29 GC patients with preoperative chemotherapy. We analyzed the relationship between CD44v9 expression and clinicopathological factors, prognosis, and pathological response to chemotherapy. In GC cell lines, we examined the relationship between CD44v9 expression and chemotherapeutic sensitivity.

RESULTS

In patients without preoperative chemotherapy, CD44v9 expression was significantly associated with depth of invasion, lymphatic permeation, vascular invasion, distant metastasis and GPx2 expression. In multivariate analysis, CD44v9 expression was an independent poor prognosis factor for overall survival and recurrence-free survival. In patients with preoperative chemotherapy, CD44v9 expression was significantly associated with worse pathological response and GPx2 expression. In GC cell lines, downregulation of CD44v9 expression enhanced chemotherapeutic sensitivity to 5-fluorouracil with changing GSH and ROS levels.

CONCLUSIONS

CD44v9-positive expression was associated with chemotherapeutic resistance by controlling intracellular accumulated ROS, suggesting that CD44v9 may be a predictive biomarker for chemotherapy in GC.

The role of oxidative stress in skeletal muscle injury and regeneration: focus on antioxidant enzymes

Reactive oxygen species (ROS) are generated in skeletal muscle both during the rest and contractile activity. Myogenic cells are equipped with antioxidant enzymes, like superoxide dismutase, catalase, glutathione peroxidase, γ-glutamylcysteine synthetase and heme oxygenase-1. These enzymes not only neutralise excessive ROS, but also affect myogenic regeneration at several stages: influence post-injury inflammatory reaction, enhance viability and proliferation of muscle satellite cells and myoblasts and affect their differentiation. Finally, antioxidant enzymes regulate also processes accompanying muscle regeneration-induce angiogenesis and reduce fibrosis. Elevated ROS production was also observed in Duchenne muscular dystrophy (DMD), a disease characterised by degeneration of muscle tissue and therefore-increased rate of myogenic regeneration. Antioxidant enzymes are consequently considered as target for therapies counteracting dystrophic symptoms. In this review we present current knowledge regarding the role of oxidative stress and systems of enzymatic antioxidant defence in muscular regeneration after both acute injury and persistent muscular degeneration.