Adipose-derived mesenchymal stem cells rescue rat hippocampal cells from aluminum oxide nanoparticle-induced apoptosis via regulation of P53, Aβ, SOX2, OCT4, and CYP2E1

Aluminium oxide nanoparticles (Al2O3-NPs) exposure impairs cardiovascular physiology and elevates health risk - proteomic and molecular mechanistic insights

The interactions of nanoparticles with biomolecules lead to toxicopathological outcomes through various mechanisms including oxidative stress. In this regard, the interplay of oxidative stress with other molecular mechanisms of cytotoxicity during aluminium oxide nanoparticles (Al2O3-NPs) induced cardiovascular toxicity was not yet precisely explored. Initially, the human serum protein interaction and its corona composition were explored through the gel/label-free proteomics (nLC-HRMS/MS) method. In addition, endothelial cells (EC) and cardiomyoblasts (CM) cultures were employed along with various oxidative stress and cell stress assays. Further, various expression studies (RT-qPCR, western blot, and immunofluorescence), kinase signalling, and siRNA mediated gene knockout assays were performed. Alongside, the in ovo impact on antioxidant enzymes and metabolomic pathways (1H NMR) in the heart validated the role of oxidative stress during cardiotoxicity. The current outcome illustrates the dose-dependent increase of cytotoxicity and caspase (3 and 9) activation. The dose-dependent elevation and its synergy with cardiovascular stress signalling (ET-1 and Ang-II) illustrate the prominent role of oxidative stress during toxicity. In conclusion, the current study connects the role of the redox system and molecular stress pathways during Al2O3-NPs induced cardiotoxicity which extends the knowledge towards the precise health risk assessment during human exposure.

Toxic effects of aluminum nanoparticles: a review

The objective of this state-of-the-art review is to summarize contemporary data on the potential toxic effects of aluminum nanoparticles (AlNPs) and discuss the underlying molecular mechanisms. In vivo studies using laboratory rodents demonstrate that lungs, liver, brain, and the immune system are the primary targets for AlNPs toxicity. Specifically, inhalation exposure to AlNPs induces lung damage by promoting inflammatory infiltration, airway remodeling, septal thickening, and bronchial hyperresponsiveness. AlNPs-induced liver damage is characterized by hepatocyte degeneration and necrosis, liver sinusoid congestion, inflammation, and fibrosis. AlNPs induces neurotoxicity resulting in neurodegeneration, neuroinflammation, altered neurotransmitter metabolism, and subsequent adverse neurobehavioral outcome. In turn, immunotoxicity of AlNPs is characterized by promotion of systemic inflammation along with impaired phagocytosis. In addition to the toxicity exerted by Al2O3NPs itself, the observed toxic effects of AlNPs may be attributed to Al3+ release from the particles with the subsequent induction of oxidative stress, inflammation, mitochondrial dysfunction, genotoxicity, cell cycle dysregulation, and cell death due to apoptosis, necrosis, and ferroptosis. It is also evident that both the size and the form of AlNPs significantly affect its cytotoxicity. However, further studies are required to explore the mechanisms of toxic effects of AlNPs, as well as its potential adverse effects on human health.

Rehabilitation of N, N'-methylenebisacrylamide-induced DNA destruction in the testis of adult rats by adipose-derived mesenchymal stem cells and conditional medium

Environmental pollutant acrylamide has toxic effect on human health. Numerous industries such as the paper, and cosmetics, use acrylamide in their manufacturing. In certain foods, acrylamide arises at extremely high temperatures. Mesenchymal stem cells can shield different tissues from the damaging effects of free radicals induced by acrylamide. This study aimed to compare the therapeutic efficacy against acrylamide-induced toxicity between adipose-derived mesenchymal stem cells (MSCs) and their conditioned media (CM), evaluating which is more effective. Seventy adult male rats were employed in this study, distributed among 5 groups. The control group consisted of 10 rats, while each of the other four groups comprised 15 rats. The AC group received a daily oral acrylamide (AC) dosage of 3 mg/kg. In the AC + AD-MSCs and AC + AD-MSCs CM groups, after 4 weeks of AC administration, rats were injected with 0.65 × 106 AD-MSCs/0.5 ml PBS and 0.5 ml of AD-MSCs CM, respectively, via the caudal vein, and were observed for 15 days. The recovery group (Rec.), subjected to 4 weeks of AC treatment, and was allowed an additional 15 days for recuperation. The result in AC and Rec. groups revealed elevated DNA damage, P53 protein levels, apoptosis, LPO, and testosterone (free and total). In contrast, the administration of CM and the transplanting of AD-MSCs decreased the levels of these proteins. According to histological analysis, treating testicular cells with AD-MSCs mitigated histopathological lesions, fibrosis, and toxicity caused by AC. The regulation of P53, LPO protein levels, and testosterone levels, supported the function of AD-MSCs in lowering testis DNA damage and apoptosis.

Prevention of methylmercury-triggered ROS-mediated impairment of embryo development by co-culture with adult adipose-derived mesenchymal stem cells

Methylmercury (MeHg) is a potent toxin that exerts deleterious effects on human health via environmental contamination. Significant effects of MeHg on neuronal development in embryogenesis have been reported. Recently, our group demonstrated that MeHg exerts toxic effects on pre- and post-implantation embryonic development processes from zygote to blastocyst stage. Our results showed that MeHg impairs embryo development by induction of apoptosis through reactive oxygen species (ROS) generation that triggers caspase-3 cleavage and activation, which, in turn, stimulates p21-activated kinase 2 (PAK2) activity. Importantly, ROS were identified as a key upstream regulator of apoptotic events in MeHg-treated blastocysts. Data from the current study further confirmed that MeHg exerts hazardous effects on cell proliferation, apoptosis, implantation, and pre- and post-implantation embryo development. Notably, MeHg-induced injury was markedly prevented by co-culture with adipose-derived mesenchymal stem cells (ADMSCs) in vitro. Furthermore, ADMSC injection significantly reduced MeHg-mediated deleterious effects on embryo, placenta, and fetal development in vivo. Further investigation of the regulatory mechanisms by which co-cultured ADMSCs could prevent MeHg-induced impairment of embryo development revealed that ADMSCs effectively reduced ROS generation and its subsequent downstream apoptotic events, including loss of mitochondrial membrane potential and activation of caspase-3 and PAK2. The collective findings indicate that co-culture with mesenchymal stem cells (MSCs) or utilization of MSC-derived cell-conditioned medium offers an effective potential therapeutic strategy to prevent impairment of embryo development by MeHg.

Gallic acid rescues uranyl acetate induced-hepatic dysfunction in rats by its antioxidant and cytoprotective potentials

BACKGROUND

The liver was identified as a primary target organ for the chemo-radiological effects of uranyl acetate (UA). Although the anti-oxidant and anti-apoptotic properties of gallic acid (GA) make it a promising phytochemical to resist its hazards, there is no available data in this area of research.

METHODS

To address this issue, eighteen rats were randomly and equally divided into three groups. One group was received carboxymethyl cellulose (vehicle of GA) and kept as a control. The UA group was injected intraperitoneally with UA at a single dose of 5 mg/kg body weight. The third group (GA + UA group) was treated with GA orally at a dose of 100 mg/kg body weight for 14 days before UA exposure. UA was injected on the 15th day of the experiment in either the UA group or the GA + UA group. The biochemical, histological, and immunohistochemical findings in the GA + UA group were compared to both control and UA groups.

RESULTS

The results showed that UA exposure led to a range of adverse effects. These included elevated plasma levels of aspartate aminotransferase, lactate dehydrogenase, total protein, globulin, glucose, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and very-low-density lipoprotein and decreased plasma levels of high-density lipoprotein cholesterol. The exposure also disrupted the redox balance, evident through decreased plasma total antioxidant capacity and hepatic nitric oxide, superoxide dismutase, reduced glutathione, glutathione-S-transferase, glutathione reductase, and glutathione peroxidase and increased hepatic oxidized glutathione and malondialdehyde. Plasma levels of albumin and alanine aminotransferase did not significantly change in all groups. Histopathological analysis revealed damage to liver tissue, characterized by deteriorations in tissue structure, excessive collagen accumulation, and depletion of glycogen. Furthermore, UA exposure up-regulated the immuno-expression of cleaved caspase-3 and down-regulated the immuno-expression of nuclear factor-erythroid-2-related factor 2 in hepatic tissues, indicating an induction of apoptosis and oxidative stress response. However, the pre-treatment with GA proved to be effective in mitigating these negative effects induced by UA exposure, except for the disturbances in the lipid profile.

CONCLUSIONS

The study suggests that GA has the potential to act as a protective agent against the adverse effects of UA exposure on the liver. Its ability to restore redox balance and inhibit apoptosis makes it a promising candidate for countering the harmful effects of chemo-radiological agents such as UA.

Al2O3 nanoparticles trigger the embryonic hepatotoxic response and potentiate TNF-α-induced apoptosis-modulatory effect of p38 MAPK and JNK inhibitors

Recent evidences illustrated that the release of aluminum oxide nanoparticles (Al₂O₃-NPs) into the biosphere may pose risk to the environment and cause adverse effects on living organisms including humans. The current study assessed the hepatotoxic effects of Al₂O₃-NPs on developing chicken embryo and cell culture models. Results demonstrated that Al₂O₃-NPs exposure causes histological abnormalities and increased the level of tissue damage markers (ALP, AST, and ALT) in the embryonic liver. Furthermore, increased oxidative stress (TBARS) and impaired function of antioxidant enzymes (SOD, CAT, and GPx) were also observed. Moreover, it adversely affects red blood cells (RBC) morphology, liver metabolism, and stress response gene expression (HO-1 and NQO-1). Dose-dependent ROS generation and cytotoxic response in addition to potentiating effect on tumor necrosis factor alpha (TNF-α)-induced apoptosis (caspase-3 activity) were also observed. Inhibition of p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) pathways modulates Al₂O₃-NPs-induced apoptosis in HepG2 cells. Novel mechanisms behind embryonic hepatotoxicity, cytotoxic potentiating effects, and possible prevention strategies have been explored.

Impact of Graphene Derivatives as Artificial Extracellular Matrices on Mesenchymal Stem Cells

Thanks to stem cells' capability to differentiate into multiple cell types, damaged human tissues and organs can be rapidly well-repaired. Therefore, their applicability in the emerging field of regenerative medicine can be further expanded, serving as a promising multifunctional tool for tissue engineering, treatments for various diseases, and other biomedical applications as well. However, the differentiation and survival of the stem cells into specific lineages is crucial to be exclusively controlled. In this frame, growth factors and chemical agents are utilized to stimulate and adjust proliferation and differentiation of the stem cells, although challenges related with degradation, side effects, and high cost should be overcome. Owing to their unique physicochemical and biological properties, graphene-based nanomaterials have been widely used as scaffolds to manipulate stem cell growth and differentiation potential. Herein, we provide the most recent research progress in mesenchymal stem cells (MSCs) growth, differentiation and function utilizing graphene derivatives as extracellular scaffolds. The interaction of graphene derivatives in human and rat MSCs has been also evaluated. Graphene-based nanomaterials are biocompatible, exhibiting a great potential applicability in stem-cell-mediated regenerative medicine as they may promote the behaviour control of the stem cells. Finally, the challenges, prospects and future trends in the field are discussed.