Selenium and Glutathione-Depleted Rats as a Sensitive Animal Model to Predict Drug-Induced Liver Injury in Humans

Reactive X (where X = O, N, S, C, Cl, Br, and I) species nanomedicine

Reactive oxygen, nitrogen, sulfur, carbonyl, chlorine, bromine, and iodine species (RXS, where X = O, N, S, C, Cl, Br, and I) have important roles in various normal physiological processes and act as essential regulators of cell metabolism; their inherent biological activities govern cell signaling, immune balance, and tissue homeostasis. However, an imbalance between RXS production and consumption will induce the occurrence and development of various diseases. Due to the considerable progress of nanomedicine, a variety of nanosystems that can regulate RXS has been rationally designed and engineered for restoring RXS balance to halt the pathological processes of different diseases. The invention of radical-regulating nanomaterials creates the possibility of intriguing projects for disease treatment and promotes advances in nanomedicine. In this comprehensive review, we summarize, discuss, and highlight very-recent advances in RXS-based nanomedicine for versatile disease treatments. This review particularly focuses on the types and pathological effects of these reactive species and explores the biological effects of RXS-based nanomaterials, accompanied by a discussion and the outlook of the challenges faced and future clinical translations of RXS nanomedicines.

Sodium selenite preserves rBM-MSCs' stemness, differentiation potential, and immunophenotype and protects them against oxidative stress via activation of the Nrf2 signaling pathway

BACKGROUND

The physiological level of reactive oxygen species (ROS) is necessary for many cellular functions. However, during the in-vitro manipulations, cells face a high level of ROS, leading to reduced cell quality. Preventing this abnormal ROS level is a challenging task. Hence, here we evaluated the effect of sodium selenite supplementation on the antioxidant potential, stemness capacity, and differentiation of rat-derived Bone Marrow MSCs (rBM-MSCs) and planned to check our hypothesis on the molecular pathways and networks linked to sodium selenite's antioxidant properties.

METHODS

MTT assay was used to assess the rBM-MSCs cells' viability following sodium selenite supplementation (concentrations of: 0.001, 0.01, 0.1, 1, 10 µM). The expression level of OCT-4, NANOG, and SIRT1 was explored using qPCR. The adipocyte differentiation capacity of MSCs was checked after Sodium Selenite treatment. The DCFH-DA assay was used to determine intracellular ROS levels. Sodium selenite-related expression of HIF-1α, GPX, SOD, TrxR, p-AKT, Nrf2, and p38 markers was determined using western blot. Significant findings were investigated by the String tool to picture the probable molecular network.

RESULTS

Media supplemented with 0.1 µM sodium selenite helped to preserve rBM-MSCs multipotency and keep their surface markers presentation; this also reduced the ROS level and improved the rBM-MSCs' antioxidant and stemness capacity. We observed enhanced viability and reduced senescence for rBM-MSCs. Moreover, sodium selenite helped in rBM-MSCs cytoprotection by regulating the expression of HIF-1 of AKT, Nrf2, SOD, GPX, and TrxR markers.

CONCLUSIONS

We showed that sodium selenite could help protect MSCs during in-vitro manipulations, probably via the Nrf2 pathway.

Dual-targetable fluorescent probe for mapping the fluctuation of peroxynitrite in drug-induced liver injury model

Drug-induced liver injury (DILI) is one of the most common and serious adverse drug reactions which can cause acute liver failure or even death in severe cases. With the incidence rate increasing over the years, DILI has became a frequent clinical liver disease and a global public health problem. As a biomarker of DILI, the detection of peroxynitrite (ONOO^-) has became a powerful tool for the early diagnosis of liver injury. Here, we synthesized five mitochondria-targetable probes, 1-5, for detecting endogenous ONOO^-. Through dye-screening, probe 5 was stood out by its excellent performance. In the presence of ONOO^-, the fluorescence signal of probe 5 reduced 40-fold in 19 s with a low detection limit (9.36 nM). At the same time, the transformation can be observed with the naked eye under sunlight or UV lamp without being affected by the other reactive species. Even better, with low toxicity and high biocompatibility, probe 5 could successfully detect endogenous ONOO^- in the mitochondrion of cells. Finally, probe 5 could specifically target the liver, and can be employed for monitoring the therapeutic effect of hepatoprotective medicine after drug-induced hepatotoxicity in vivo. In brief, probe 5 has the practical application capability for diagnosing the severity of the liver injury and researching the therapeutic effect of antidote in complex bio-systems.

Porous Se@SiO2 Nanoparticles Attenuate Radiation-Induced Cognitive Dysfunction via Modulating Reactive Oxygen Species

Radiotherapy has been widely used to manage primary and metastatic brain tumors. However, hippocampal damage and subsequent cognitive dysfunction are common complications of whole brain radiation (WBI). In this study, Se@SiO₂ nanoparticles (NPs) with antioxidant properties were synthesized. Se@SiO₂ NPs were characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The reactive oxygen species (ROS) scavenging ability of Se@SiO₂ NPs was assessed using a dichloro-dihydro-fluorescein diacetate (DCFH-DA) probe. Apoptosis of HT-22 cells treated with H₂O₂ and Se@SiO₂ NPs was assessed by annexin V-FITC/PI and JC-1 staining. Western blotting was used to evaluate inflammation-related signaling pathways. In vivo, the distribution and excretion of Se@SiO₂ NPs were assessed using in vivo imaging system (IVIS). The biosafety and antioxidant effects of Se@SiO₂ NPs were assessed. Neurogenesis in the hippocampus of mice was detected through neuron-specific nuclear protein (NeuN) and 5-bromo-2'-deoxyuridine (BrdU) immunofluorescence staining. The cognitive abilities of mice were also assessed using the Morris water maze test. Results showed that porous Se@SiO₂ NPs were successfully synthesized with uniform spherical structures. In vitro, Se@SiO₂ NPs inhibited ROS levels in mouse hippocampal neuronal cell line HT-22 treated with H₂O₂. Furthermore, Se@SiO₂ NPs suppressed the apoptotic rate of HT-22 cells by regulating apoptosis-related proteins. Se@SiO₂ NPs regulated the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways, thereby reducing the expression of inflammatory factors. In vivo, Se@SiO₂ NPs showed high biocompatibility at a concentration of 1.25 μg/μL. Se@SiO₂ NPs inhibited ROS and promoted neurogenesis in the hippocampus, as well as improved cognitive ability in radiation-induced mice. In conclusion, Se@SiO₂ NPs protected the hippocampus from oxidative stress injury and neuroinflammation. Se@SiO₂ NPs treatment may be a potential therapeutic strategy for radiation-induced cognitive dysfunction.

Microsomal prostaglandin E2 synthase-1 and its inhibitors: Molecular mechanisms and therapeutic significance

Inflammation is closely linked to the abnormal phospholipid metabolism chain of cyclooxygenase-2/microsomal prostaglandin E₂ synthase-1/prostaglandin E₂ (COX-2/mPGES-1/PGE₂). In clinical practice, non-steroidal anti-inflammatory drugs (NSAIDs) as upstream COX-2 enzyme activity inhibitors are widely used to block COX-2 cascade to relieve inflammatory response. However, NSAIDs could also cause cardiovascular and gastrointestinal side effects due to its inhibition on other prostaglandins generation. To avoid this, targeting downstream mPGES-1 instead of upstream COX is preferable to selectively block overexpressed PGE₂ in inflammatory diseases. Some mPGES-1 inhibitor candidates including synthetic compounds, natural products and existing anti-inflammatory drugs have been proved to be effective in in vitro experiments. After 20 years of in-depth research on mPGES-1 and its inhibitors, ISC 27864 have completed phase II clinical trial. In this review, we intend to summarize mPGES-1 inhibitors focused on their inhibitory specificity with perspectives for future drug development.

Oxidative Stress Management in Chronic Liver Diseases and Hepatocellular Carcinoma

Chronic viral hepatitis B and C and non-alcoholic fatty liver disease (NAFLD) have been widely acknowledged to be the leading causes of liver cirrhosis and hepatocellular carcinoma. As anti-viral treatment progresses, the impact of NAFLD is increasing. NAFLD can coexist with chronic viral hepatitis and exacerbate its progression. Oxidative stress has been recognized as a chronic liver disease progression-related and cancer-initiating stress response. However, there are still many unresolved issues concerning oxidative stress, such as the correlation between the natural history of the disease and promising treatment protocols. Recent findings indicate that oxidative stress is also an anti-cancer response that is necessary to kill cancer cells. Oxidative stress might therefore be a cancer-initiating response that should be down regulated in the pre-cancerous stage in patients with risk factors for cancer, while it is an anti-cancer cell response that should not be down regulated in the post-cancerous stage, especially in patients using anti-cancer agents. Antioxidant nutrients should be administered carefully according to the patients’ disease status. In this review, we will highlight these paradoxical effects of oxidative stress in chronic liver diseases, pre- and post-carcinogenesis.

4-hydroxy-2(3H)-benzoxazolone alleviates acetaminophen-induced hepatic injury by inhibiting NF-κB and activating Nrf2/HO-1 signaling pathways

The purpose of this study is to evaluate the protective effect of 4-hydroxy-2(3H)-benzoxazolone from Acanthus ilicifolius (HBAI) on acute liver injury induced by acetaminophen in mice and its mechanism. Mice were continuously treated with HBAI (200, 100, 50 mg/kg) once a day for 10 days. After that, the mice were fasted for 8 hours, followed by intraperitoneal injection of acetaminophen (300 mg/kg). The results showed that HBAI pretreatment significantly reduced acetaminophen-induced liver tissue congestion, hepatocyte apoptosis and necrosis, and inflammatory cell infiltration. HBAI could effectively reduce the levels of serum alanine aminotransferase, aspartate aminotransferase, total bilirubin, reactive oxygen species and malondialdehyde. Interestingly, the activities of liver catalase, superoxide dismutase, glutathione and glutathione reductase were enhanced by HBAI pretreatment. Moreover, HBAI pretreatment alleviated acetaminophen-induced hepatocyte apoptosis by regulating the expression of Bcl-2 family proteins and the mitochondrial function. Further study showed that HBAI pretreatment effectively promoted the expression of Nrf2 and its signal downstream HO-1, NQO1, GCLC, GCLM, and MGST-1, suggesting the activation of the Nrf2/HO-1 signaling pathway. Meanwhile, HBAI attenuated the phosphorylation of NF-κBp65, IKKα/β, and IκBα, as well as the expression of NF-κBp50, which indicated that HBAI blocked the signal transduction of NF-κB pathway. In conclusion, HBAI protects against acetaminophen-induced acute liver injury by inhibiting the NF-κB and activating Nrf2/HO-1 signaling pathways.