Bcl-2 functions in an antioxidant pathway to prevent apoptosis

Antioxidant and Anti-Apoptotic Neuroprotective Effects of Cinnamon in Imiquimod-Induced Lupus

BACKGROUND

Despite accumulating evidence correlating oxidative stress with lupus disease activity, the brain redox pathways are still poorly investigated. Cinnamomum cassia, a widely used spice with powerful antioxidant properties, could be a novel therapeutic candidate in lupus.

METHODS

C57BL/6J female mice were divided into five groups: sham, sham-cinnamon, lupus, lupus-cinnamon starting from induction, and lupus-cinnamon starting two weeks before induction. Lupus was induced by skin application on the right ear with 1.25 mg of 5% imiquimod cream three times per week for six weeks. Cinnamomum cassia was given orally, five days per week, at 200 mg/kg.

RESULTS

Concomitant to TLR7-MYD88 pathway activation, the p-NRF2/NRF2 and p-FOXO3/FOXO3 ratios were increased in the hippocampus and alleviated by cinnamon treatment. BCL-2 positivity was enhanced in hippocampal neurons and reversed only by preventive cinnamon administration. In vitro, exposure of hippocampal cells to the plasma of different groups induced a surge in oxidative stress. This was associated with an increased t-BID/BID ratio. Cinnamon treatment, particularly in the preventive arm, normalized these modifications.

CONCLUSIONS

Our study shows a neuroprotective effect of cinnamon by rescuing brain redox and apoptosis homeostasis in lupus, paving the way for its use as a natural therapeutic compound in the clinical management of lupus.

Fmp40 ampylase regulates cell survival upon oxidative stress by controlling Prx1 and Trx3 oxidation

Reactive oxygen species (ROS), play important roles in cellular signaling, nonetheless are toxic at higher concentrations. Cells have many interconnected, overlapped or backup systems to neutralize ROS, but their regulatory mechanisms remain poorly understood. Here, we reveal an essential role for mitochondrial AMPylase Fmp40 from budding yeast in regulating the redox states of the mitochondrial 1-Cys peroxiredoxin Prx1, which is the only protein shown to neutralize H2O2 with the oxidation of the mitochondrial glutathione and the thioredoxin Trx3, directly involved in the reduction of Prx1. Deletion of FMP40 impacts a cellular response to H2O2 treatment that leads to programmed cell death (PCD) induction and an adaptive response involving up or down regulation of genes encoding, among others the catalase Cta1, PCD inducing factor Aif1, and mitochondrial redoxins Trx3 and Grx2. This ultimately perturbs the reduced glutathione and NADPH cellular pools. We further demonstrated that Fmp40 AMPylates Prx1, Trx3, and Grx2 in vitro and interacts with Trx3 in vivo. AMPylation of the threonine residue 66 in Trx3 is essential for this protein's proper endogenous level and its precursor forms' maturation under oxidative stress conditions. Additionally, we showed the Grx2 involvement in the reduction of Trx3 in vivo. Taken together, Fmp40, through control of the reduction of mitochondrial redoxins, regulates the hydrogen peroxide, GSH and NADPH signaling influencing the yeast cell survival.

Gut microbiome, short-chain fatty acids, alpha-synuclein, neuroinflammation, and ROS/RNS: Relevance to Parkinson's disease and therapeutic implications

In this review, we explore how short-chain fatty acids (SCFAs) produced by the gut microbiome affect Parkinson's disease (PD) through their modulatory interactions with alpha-synuclein, neuroinflammation, and oxidative stress mediated by reactive oxygen and nitrogen species (ROS/RNS). In particular, SCFAs-such as acetate, propionate, and butyrate-are involved in gut-brain communication and can modulate alpha-synuclein aggregation, a hallmark of PD. The gut microbiome of patients with PD has lower levels of SCFAs than healthy individuals. Probiotics may be a potential strategy to restore SCFAs and alleviate PD symptoms, but the underlying mechanisms are not fully understood. Also in this review, we discuss how alpha-synuclein, present in the guts and brains of patients with PD, may induce neuroinflammation and oxidative stress via ROS/RNS. Alpha-synuclein is considered an early biomarker for PD and may link the gut-brain axis to the disease pathogenesis. Therefore, elucidating the role of SCFAs in the gut microbiome and their impact on alpha-synuclein-induced neuroinflammation in microglia and on ROS/RNS is crucial in PD pathogenesis and treatment.

A review of cumulative toxic effects of environmental endocrine disruptors on the zebrafish immune system: Characterization methods, toxic effects and mechanisms

Environmental endocrine disrupting chemicals (EDCs), are a type of exogenous organic pollutants, are ubiquitous in natural aquatic environments. Currently, in addition to neurological, endocrine, developmental and reproductive toxicity, ecotoxicology studies on immunotoxicity are receiving increasing attention. In this review, the composition of immune system of zebrafish, the common indicators of immunotoxicity, the immunotoxicity of EDCs and their molecular mechanism were summarized. We reviewed the immunotoxicity of EDCs on zebrafish mainly in terms of immune organs, immunocytes, immune molecules and immune functions, meanwhile, the possible molecular mechanisms driving these effects were elucidated in terms of endocrine disruption, dysregulation of signaling pathways, and oxidative damage. Hopefully, this review will provide a reference for further investigation of the immunotoxicity of EDCs.

The application of human-derived cell lines in neurotoxicity studies of environmental pollutants

As industrial and societal advancements progress, an increasing number of environmental pollutants linked to human existence have been substantiated to elicit neurotoxicity and developmental neural toxicity. For research in this field, human-derived neural cell lines have become excellent in vitro models. This study examines the utilization of immortalized cell lines, specifically the SH-SY5Y human neuroblastoma cell line, and neural cells derived from human pluripotent stem cells, in the investigation of neurotoxicity and developmental neural toxicity caused by environmental pollutants. The study also explores the culturing techniques employed for these cell lines and provides an overview of the standardized assays used to assess various biological endpoints. The environmental pollutants involved include a variety of organic compounds, heavy metals, and microplastics. The utilization of cell lines derived from human sources holds significant significance in elucidating the neurotoxic effects of environmental pollutants and the underlying mechanisms. Finally, we propose the possibility of improving the in vitro model of the human nervous system and the toxicity detection methods.

Non-canonical BIM-regulated energy metabolism determines drug-induced liver necrosis

Paracetamol (acetaminophen, APAP) overdose severely damages mitochondria and triggers several apoptotic processes in hepatocytes, but the final outcome is fulminant necrotic cell death, resulting in acute liver failure and mortality. Here, we studied this switch of cell death modes and demonstrate a non-canonical role of the apoptosis-regulating BCL-2 homolog BIM/Bcl2l11 in promoting necrosis by regulating cellular bioenergetics. BIM deficiency enhanced total ATP production and shifted the bioenergetic profile towards glycolysis, resulting in persistent protection from APAP-induced liver injury. Modulation of glucose levels and deletion of Mitofusins confirmed that severe APAP toxicity occurs only in cells dependent on oxidative phosphorylation. Glycolytic hepatocytes maintained elevated ATP levels and reduced ROS, which enabled lysosomal recycling of damaged mitochondria by mitophagy. The present study highlights how metabolism and bioenergetics affect drug-induced liver toxicity, and identifies BIM as important regulator of glycolysis, mitochondrial respiration, and oxidative stress signaling.

Insights on Natural Products Against Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that causes the death of motor neurons and consequent muscle paralysis. Despite many efforts to address it, current therapy targeting ALS remains limited, increasing the interest in complementary therapies. Over the years, several herbal preparations and medicinal plants have been studied to prevent and treat this disease, which has received remarkable attention due to their blood-brain barrier penetration properties and low toxicity. Thus, this review presents the therapeutic potential of a variety of medicinal herbs and their relationship with ALS and their physiopathological pathways.

Anticancer effect of umbelliferone on MKN-45 and MIA PaCa-2 cell lines

In this study, the anticancer activity of umbelliferone (7-hydroxycoumarin-UMB) was investigated in MKN-45 human gastric cancer and MIA PaCa-2 human pancreatic cancer cells. The cytotoxic effect of UMB on MKN-45 and MIA PaCa-2 cells was determined by WST-8 cell viability assay; the effect on colony formation and migration potential by colony forming assay and wound healing/cell migration assay. Apoptotic effect of UMB was determined by measuring the change in mitochondrial membrane potentials, reactive oxygen species levels, and Caspase-3 activities in cells. Anticancer drugs cisplatin and gemcitabine were used as positive controls in experiments, and NIH/Swiss 3 T3 mouse embryonic fibroblast cells were used as a healthy cell group. The results of this study showed that umbelliferone had a significant cytotoxic effect in MKN-45 and MIA PaCa-2 cells, especially after 72 h treatment, while its cytotoxic effect in NIH/3 T3 cells was low. Furthermore, UMB reduces significantly the potential of cells to colonize and migrate; it has been determined that it causes apoptosis by decreasing the mitochondrial membrane potential, increasing intracellular ROS levels and Caspase-3 activity. UMB was found to have more anticancer effect on MIA PaCa-2 cells compared to MKN-45 cells. This showed that UMB has a cell-selective effect.

25 Years of PI5P

The accidental discovery of PI5P (phosphatidylinositol-5-phosphate) was published 25 years ago, when PIP5K type II (phosphoinositide-4-phosphate 5-kinase) was shown to actually be a 4-kinase that uses PI5P as a substrate to generate PI(4,5)P2. Consequently, PIP5K type II was renamed to PI5P4K, or PIP4K for short, and PI5P became the last of the 7 signaling phosphoinositides to be discovered. Much of what we know about PI5P comes from genetic studies of PIP4K, as the pathways for PI5P synthesis, the downstream targets of PI5P and how PI5P affects cellular function all remain largely enigmatic. Nevertheless, PI5P and PI5P-dependent PI(4,5)P2 synthesis have been clearly implicated in metabolic homeostasis and in diseases such as cancer. Here, we review the past 25 years of PI5P research, with particular emphasis on the impact this small signaling lipid has on human health.

Effects of hypoxia on the gill morphological structure, apoptosis and hypoxia-related gene expression in blunt snout bream (Megalobrama amblycephala)

The blunt snout bream (Megalobrama amblycephala) is a typical hypoxia-sensitive fish, and hypoxia stress leads to reduced vitality and yield during aquaculture. To explore the specific adaptation mechanism under hypoxia, the blunt snout bream was treated with hypoxia (DO = 2.0 ± 0.1 mg/L) for 24 h, followed by 3 h of recovery. Our results depicted that the gill filament structure of blunt snout bream changed after hypoxia. During hypoxia for 24 h, the gill filament structure was altered, including a more than 80% expansion of the lamellar respiratory surface area and a proportionate apoptosis decrease in interlamellar cell mass (ILCM) volume. Thus, the water-blood diffusion distance was shortened to less than 46%. During hypoxia for 24 h, the activity of ROS in gill tissue increased significantly (p < 0.05), while the mitochondrial membrane potential decreased significantly (p < 0.05). During hypoxia, mRNA expression level of anti-apoptotic gene Bcl-2 in the gills of blunt snout bream decreased significantly (p < 0.05), while the expression of pro-apoptotic gene Bax mRNA increased significantly (p < 0.05). Thus, the ratio of Bax/Bcl-2 mRNA increased in the gills of blunt snout bream to promote the activity of Caspase-3. Together, our results indicated hypoxia-induced apoptosis in the gills of blunt snout bream through the mitochondrial pathway. In addition, a decreased expression of Phd1 and an increased expression of Hif-1α in gills under hypoxia stress indicates that blunt snout bream may cope with hypoxia-induced apoptosis by enhancing the HIF pathway. These results provide new insights into fish's adaptation strategies and mechanisms of hypoxia.

Unlocking the potential of snake venom-based molecules against the malaria, Chagas disease, and leishmaniasis triad

Malaria, leishmaniasis and Chagas disease are vector-borne protozoal infections with a disproportionately high impact on the most fragile societies in the world, and despite malaria-focused research gained momentum in the past two decades, both trypanosomiases and leishmaniases remain neglected tropical diseases. Affordable effective drugs remain the mainstay of tackling this burden, but toxicicty, inneficiency against later stage disease, and drug resistance issues are serious shortcomings. One strategy to overcome these hurdles is to get new therapeutics or inspiration in nature. Indeed, snake venoms have been recognized as valuable sources of biomacromolecules, like peptides and proteins, with antiprotozoal activity. This review highlights major snake venom components active against at least one of the three aforementioned diseases, which include phospholipases A2, metalloproteases, L-amino acid oxidases, lectins, and oligopeptides. The relevance of this repertoire of biomacromolecules and the bottlenecks in their clinical translation are discussed considering approaches that should increase the success rate in this arduous task. Overall, this review underlines how venom-derived biomacromolecules could lead to pioneering antiprotozoal treatments and how the drug landscape for neglected diseases may be revolutionized by a closer look at venoms. Further investigations on poorly studied venoms is needed and could add new therapeutics to the pipeline.

Current opinions on mitophagy in fungi

Mitophagy, as one of the most important cellular processes to ensure quality control of mitochondria, aims at transporting damaged, aging, dysfunctional or excess mitochondria to vacuoles (plants and fungi) or lysosomes (mammals) for degradation and recycling. The normal functioning of mitophagy is critical for cellular homeostasis from yeasts to humans. Although the role of mitophagy has been well studied in mammalian cells and in certain model organisms, especially the budding yeast Saccharomyces cerevisiae, our understanding of its significance in other fungi, particularly in pathogenic filamentous fungi, is still at the preliminary stage. Recent studies have shown that mitophagy plays a vital role in spore production, vegetative growth and virulence of pathogenic fungi, which are very different from its roles in mammal and yeast. In this review, we summarize the functions of mitophagy for mitochondrial quality and quantity control, fungal growth and pathogenesis that have been reported in the field of molecular biology over the past two decades. These findings may help researchers and readers to better understand the multiple functions of mitophagy and provide new perspectives for the study of mitophagy in fungal pathogenesis.Abbreviations: AIM/LIR: Atg8-family interacting motif/LC3-interacting region; BAR: Bin-Amphiphysin-Rvs; BNIP3: BCL2 interacting protein 3; CK2: casein kinase 2; Cvt: cytoplasm-to-vacuole targeting; ER: endoplasmic reticulum; IMM: inner mitochondrial membrane; mETC: mitochondrial electron transport chain; OMM: outer mitochondrial membrane; OPTN: optineurin; PAS: phagophore assembly site; PD: Parkinson disease; PE: phosphatidylethanolamine; PHB2: prohibitin 2; PX: Phox homology; ROS, reactive oxygen species; TM: transmembrane.

Molecular mechanisms on how FABP5 inhibitors promote apoptosis-induction sensitivity of prostate cancer cells

Previous work showed that FABP5 inhibitors suppressed the malignant progression of prostate cancer cells, and this suppression might be achieved partially by promoting apoptosis. But the mechanisms involved were not known. Here, we investigated the effect of inhibitors on apoptosis and studied the relevant mechanisms. WtrFABP5 significantly reduced apoptotic cells in 22Rv1 and PC3 by 18% and 42%, respectively. In contrast, the chemical inhibitor SB-FI-26 produced significant increases in percentages of apoptotic cells in 22Rv1 and PC3 by 18.8% (±4.1) and 4.6% (±1.1), respectively. The bio- inhibitor dmrFABP5 also did so by 23.1% (±2.4) and 15.8% (±3.0), respectively, in these cell lines. Both FABP5 inhibitors significantly reduced the levels of the phosphorylated nuclear fatty acid receptor PPARγ, indicating that these inhibitors promoted apoptosis-induction sensitivity of the cancer cells by suppressing the biological activity of PPARγ. Thus, the phosphorylated PPARγ levels were reduced by FABP5 inhibitors, the levels of the phosphorylated AKT and activated nuclear factor kapper B (NFκB) were coordinately altered by additions of the inhibitors. These changes eventually led to the increased levels of cleaved caspase-9 and cleaved caspase-3; and thus, increase in the percentage of cells undergoing apoptosis. In untreated prostate cancer cells, increased FABP5 suppressed the apoptosis by increasing the biological activity of PPARγ, which, in turn, led to a reduced apoptosis by interfering with the AKT or NFκB signaling pathway. Our results suggested that the FABP5 inhibitors enhanced the apoptosis-induction of prostate cancer cells by reversing the biological effect of FABP5 and its related pathway.

Microplastics alter development, behavior, and innate immunity responses following bacterial infection during zebrafish embryo-larval development

Although the hazards of microplastics (MPs) have been explored, no complete data exists on the effect of MPs on the egg chorion. This study aims to evaluate the modification of immune responses, metabolism, and behavior of zebrafish larvae (Danio rerio) depending on the moment of exposure. Larvae were exposed to 5 μm polystyrene microbeads at a concentration of 0, 100, or 1000 μg/l, according to a specified times of exposure (0-4, 4-8, 0-8 days postfertilization (dpf)), followed by a bacterial challenge at 8 dpf. After every 4 and 8 dpf, swimming activity, gene expression related to oxidative stress and immune system responses were assessed. During embryonic development, larvae exposed to a concentration of 1000 μg/l MPs already showed a significantly reduced tail coiling frequency, yolk sac resorption and heartbeat. At 8 dpf, swimming activity was altered, even without ingestion and a few days after the end of MP exposure. Our results indicated a difference in immune system (nfkb, il1β) and apoptosis (casp3a, bcl2) related gene expression depending on the timing of MP exposure, which highlighted a contrasting sensitivity according to the exposure time in MP studies. This study brings new insight into how MPs might affect zebrafish larvae health and development even without ingestion.

The 2-Oxoglutarate Carrier Is S-Nitrosylated in the Spinal Cord of G93A Mutant hSOD1 Mice Resulting in Disruption of Mitochondrial Glutathione Transport

Mitochondrial oxidative stress and dysfunction are strongly implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). Glutathione (GSH) is an endogenous antioxidant that exists as distinct cytosolic and mitochondrial pools. The status of the mitochondrial GSH pool is reliant on transport from the cytosol through the 2-oxoglutarate carrier (OGC), an inner membrane anion carrier. We have previously reported that the outer mitochondrial membrane protein, Bcl-2, directly binds GSH and is a key regulator of OGC-dependent mitochondrial GSH transport. Here, we show that G93A mutant SOD1 (Cu, Zn-superoxide dismutase) reduces the binding of GSH to Bcl-2 and disrupts mitochondrial GSH uptake in vitro. In the G93A mutant hSOD1 mouse model of ALS, mitochondrial GSH is significantly depleted in spinal cord of end-stage mice. Finally, we show that OGC is heavily S-nitrosylated in the spinal cord of end-stage mice and consequently, the GSH uptake capacity of spinal cord mitochondria isolated from these mutant mice is significantly diminished. Collectively, these findings suggest that spinal cord GSH depletion, particularly at the level of the mitochondria, plays a significant role in ALS pathogenesis induced by mutant SOD1. Furthermore, the depletion of mitochondrial GSH in the G93A mutant hSOD1 mouse model may be caused by the S-nitrosylation of OGC and the capacity of mutant SOD1 to disrupt the Bcl-2/GSH interaction, resulting in a disruption of mitochondrial GSH transport.

Oxidative Stress and Extracellular Matrix Remodeling Are Signature Pathways of Extracellular Vesicles Released upon Morphine Exposure on Human Brain Microvascular Endothelial Cells

Morphine, a commonly used antinociceptive drug in hospitals, is known to cross the blood-brain barrier (BBB) by first passing through brain endothelial cells. Despite its pain-relieving effect, morphine also has detrimental effects, such as the potential induction of redox imbalance in the brain. However, there is still insufficient evidence of these effects on the brain, particularly on the brain endothelial cells and the extracellular vesicles that they naturally release. Indeed, extracellular vesicles (EVs) are nanosized bioparticles produced by almost all cell types and are currently thought to reflect the physiological state of their parent cells. These vesicles have emerged as a promising source of biomarkers by indicating the functional or dysfunctional state of their parent cells and, thus, allowing a better understanding of the biological processes involved in an adverse state. However, there is very little information on the morphine effect on human brain microvascular endothelial cells (HBMECs), and even less on their released EVs. Therefore, the current study aimed at unraveling the detrimental mechanisms of morphine exposure (at 1, 10, 25, 50 and 100 µM) for 24 h on human brain microvascular endothelial cells as well as on their associated EVs. Isolation of EVs was carried out using an affinity-based method. Several orthogonal techniques (NTA, western blotting and proteomics analysis) were used to validate the EVs enrichment, quality and concentration. Data-independent mass spectrometry (DIA-MS)-based proteomics was applied in order to analyze the proteome modulations induced by morphine on HBMECs and EVs. We were able to quantify almost 5500 proteins in HBMECs and 1500 proteins in EVs, of which 256 and 148, respectively, were found to be differentially expressed in at least one condition. Pathway enrichment analysis revealed that the "cell adhesion and extracellular matrix remodeling" process and the "HIF1 pathway", a pathway related to oxidative stress responses, were significantly modulated upon morphine exposure in HBMECs and EVs. Altogether, the combination of proteomics and bioinformatics findings highlighted shared pathways between HBMECs exposed to morphine and their released EVs. These results put forward molecular signatures of morphine-induced toxicity in HBMECs that were also carried by EVs. Therefore, EVs could potentially be regarded as a useful tool to investigate brain endothelial cells dysfunction, and to a different extent, the BBB dysfunction in patient circulation using these "signature pathways".

The Microalga Skeletonema marinoi Induces Apoptosis and DNA Damage in K562 Cell Line by Modulating NADPH Oxidase

Chronic myeloid leukemia (CML) is a myeloproliferative disease that activates multiple signaling pathways, causing cells to produce higher levels of reactive oxygen species (ROS). Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) are a major generator of ROS in leukemia, and marine natural products have shown promising activities for the treatment of hematopoietic malignancies. In the present study, we investigated the effect of the marine microalga Skeletonema marinoi (S.M.), a ubiquitous diatom that forms massive blooms in the oceans, on the human leukemia cell line K562. The effects of S.M. extract on cell viability, production of ROS, nitric oxide (NO), and apoptosis were examined. In this preliminary work, S.M. was able to decrease cell viability (p < 0.05) and increase apoptosis levels (p < 0.05) in K562 cells after 48 h of treatment. In addition, the levels of NOX, NO, and malondialdehyde (MDA) were reduced in K562-treated cells (p < 0.05), whereas the levels of SOD, CAT, and GPx increased during treatment (p < 0.05). Finally, analyzing Bax and Bcl-2 expression, we found a significant increase in the proapoptotic protein Bax and a sustained decrease in the antiapoptotic protein Bcl-2 (p < 0.05) in the K562-treated cells.

Plastid methylerythritol phosphate pathway participates in the hypersensitive response-related cell death in Nicotiana benthamiana

Programmed cell death (PCD), a characteristic feature of hypersensitive response (HR) in plants, is an important cellular process often associated with the defense response against pathogens. Here, the involvement of LytB, a gene encoding 4-hydroxy-3-methylbut-2-enyl diphosphate reductase that participates in the final step of the plastid methylerythritol phosphate (MEP) pathway, in plant HR cell death was studied. In Nicotiana benthmiana plants, silencing of the NbLytB gene using virus-induced gene silencing (VIGS) caused plant growth retardation and albino leaves with severely malformed chloroplasts. In NbLytB-silenced plants, HR-related cell death mediated by the expression of either the human proapoptotic protein gene Bax or an R gene with its cognate Avr effector gene was inhibited, whereas that induced by the nonhost pathogen Pseudomonas syringae pv. syringae 61 was enhanced. To dissect the isoprenoid pathway and avoid the pleiotropic effects of VIGS, chemical inhibitors that specifically inhibit isoprenoid biosynthesis in plants were employed. Treatment of N. benthamiana plants with fosmidomycin, a specific inhibitor of the plastid MEP pathway, effectively inhibited HR-related PCD, whereas treatment with mevinolin (a cytoplasmic mevalonate pathway inhibitor) and fluridone (a carotenoid biosynthesis inhibitor) did not. Together, these results suggest that the MEP pathway as well as reactive oxygen species (ROS) generation in the chloroplast play an important role in HR-related PCD, which is not displaced by the cytosolic isoprenoid biosynthesis pathway.

Effect of muscone on anti-apoptotic ability of muskrat prostate primary cells

Muskrat is a small fur animal with a pair of scent glands that can secrete muskrat musk during breeding season. The consensus is muskrat musk functions as a pheromone, but we hypothesized it has a broader role. In previous research, we found the presence of muscone in muskrat musk. To study whether the muscone can affect the apoptosis of muskrat prostate, we carried out the following investigations. Primary muskrat prostate cells were cultured and treated with muscone. Then we drew cell proliferation curves by applying the CCK-8 and used TdT-mediated dUTP nick end labeling (TUNEL) to detect apoptosis. Levels of mRNA transcription and protein expression of Bcl-2 as well as Bax were detected by qRT-PCR and the Western blot. Meanwhile, we collected tissue samples of muskrat prostates and froze sections to analyze the fluorescence signal intensity of BCL-2 and BAX via immunofluorescence. Under the treatment of 30 μmol/L muscone, the proliferation rate of the experimental group exceeded that of the control group, and the proportion of cells undergoing apoptosis was lower in the experimental group. The qRT-PCR and Western blot result showed that, in the experimental group, the ratio of Bcl-2 to Bax mRNA transcription levels increased by 2.85 times and their corresponding protein expression ratio increased by 2.37 times (P < 0.05). Immunofluorescence results were consistent with the cell experiment's results. The fluorescence signal intensity of BCL-2 was higher in the breeding season than nonbreeding season but vice versa for BAX. Based on these results, we speculate that the muscone could regulates prostate development by inhibiting apoptosis.

MYC sensitises cells to apoptosis by driving energetic demand

The MYC oncogene is a potent driver of growth and proliferation but also sensitises cells to apoptosis, which limits its oncogenic potential. MYC induces several biosynthetic programmes and primary cells overexpressing MYC are highly sensitive to glutamine withdrawal suggesting that MYC-induced sensitisation to apoptosis may be due to imbalance of metabolic/energetic supply and demand. Here we show that MYC elevates global transcription and translation, even in the absence of glutamine, revealing metabolic demand without corresponding supply. Glutamine withdrawal from MRC-5 fibroblasts depletes key tricarboxylic acid (TCA) cycle metabolites and, in combination with MYC activation, leads to AMP accumulation and nucleotide catabolism indicative of energetic stress. Further analyses reveal that glutamine supports viability through TCA cycle energetics rather than asparagine biosynthesis and that TCA cycle inhibition confers tumour suppression on MYC-driven lymphoma in vivo. In summary, glutamine supports the viability of MYC-overexpressing cells through an energetic rather than a biosynthetic mechanism.

N-trans-feruloyltyramine Protects Human Neuroblastoma SK-N-SH Cell Line Against H2O2-Induced Cytotoxicity

Excessive accumulation of reactive oxygen species (ROS) has been regarded as a major contributor of pathogenesis in neurodegenerative diseases. N- trans-feruloyltyramine (NTF), an alkaloid isolated from several plants, has demonstrated an ability to be a potent antioxidant. In this study, the antioxidative and anti-apoptotic properties of NTF extracted from the stems of Polyalthia suberosa were investigated in the human neuroblastoma cell line SK-N-SH. NTF at concentrations ranging from 10 µM to 500 µM were not toxic to cells and reduced intracellular ROS levels significantly. Furthermore, pre-treatment of NTF significantly decreased H2O2-induced ROS generation and attenuated H2O2-mediated cytotoxicity. An increase in the expression of Bax and activated caspase-3 and reduction of Bcl-2 mediated by H2O2 was reversed by pre-treating the cells with 100 µM NTF. Likewise, NTF suppressed the increase of caspase-3 activity induced by H2O2. In conclusion, the findings reveal that NTF improves H2O2-induced intracellular ROS generation and decreases apoptosis. These protective effects of NTF could be useful for oxidative stress-related neurodegenerative conditions.

Design, synthesis and bioactivity of novel naphthalimide-benzotriazole conjugates against A549 cells via targeting BCL2 G-quadruplex and inducing autophagy

AIMS

In this study, a series of novel naphthalimide-benzotriazole conjugates (1a-3c) based on 1, 8-naphthalimide as a core skeleton, aiming at G-quadruplexes, were designed and synthesized, and their anti-cancer activity and mechanism were studied.

MATERIALS AND METHODS

Using the CCK-8 assay, FRET melting, EMSA, CD, and molecular docking, intracellular assays, western blotting, immunofluorescence, and flow cytometry.

KEY FINDINGS

By the CCK-8 assay, it was found that the compound, 2-(3-(piperazin-1-yl)propyl)-6-(1H-benzo [d][1,2,3]triazol-1-yl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (3a), has better activity against A549 cells. Through extracellular assays, including FRET melting, EMSA, CD, and molecular docking, results showed that 3a selectively interacted with BCL2 G-quadruplex(es). Further studies by intracellular assays, including western blotting, immunofluorescence, flow cytometry, etc., verified that 3a mediated the death of A549 cells by two pathways: inhibition of the expression of the BCL2 gene, causing tumor cell apoptosis, and promotion of genetic instability, causing autophagy. This study suggests that the type of compounds, in particular, 3a, may be a potential molecule to explore for BCL2 G-quadruplex-targeted drugs against lung cancer.

SIGNIFICANCE

Our findings demonstrate that compound 3a as a BCL2 G-quadruplex ligand induces DNA damage, autophagy, and apoptosis in A549 cells. This study provides us with a type of lead compound as an anti-tumor drug.

β-Carotene extracted from Blakeslea trispora attenuates oxidative stress, inflammatory, hepatic injury and immune damage induced by copper sulfate in zebrafish (Danio rerio)

β-Carotene, as a kind of potent antioxidant compounds, has gained extensive attention. Blakeslea trispora, a filiform aerobic fungus, has been proposed as a natural source of β-carotene for commercial exploitation. However, it has not yet been investigated whether β-carotene extracted from Blakeslea trispora can attenuate oxidative stress, inflammatory, liver injury and immune damage of zebrafish (Danio rerio) exposed to copper sulfate (CuSO₄). In this study, we evaluated the effects of β-carotene on migration of GFP-labeled neutrophils, histological changes of liver, markers of oxidative, inflammatory cytokines and transaminase analysis, as well as the expression and activities of apoptosis, immune-related certain genes in zebrafish treated with different concentrations of β-carotene (0, 10, 20, 40 μg/mL) after exposure to CuSO₄. The results indicated that β-carotene reduced migration of neutrophils and released liver damage. What's more, β-carotene was found to reduce the index levels of oxidative stress response (HMOX-1, reactive oxygen species (ROS), NADPH, MDA), inflammatory factors (interleukine-1β (IL-1β), interleukine-6 (IL-6), interleukine-8 (IL-8), tumor necrosis factor-α (TNF-α)), liver function protein (AST, ALT) which increased by CuSO₄. β-Carotene also promoted the activities of SOD, GSH-Px, ACP, AKP and LZM and increased the protein of immune-related factors, IgM and IFN-γ after exposure to CuSO₄. Thus, our results demonstrate that β-carotene has an antioxidant, anti-inflammatory and hepatoprotective activity and participation in immunoregulation.

Toxicological impacts of nanopolystyrene on zebrafish oocyte with insight into the mechanism of action: An expression-based analysis

Many studies have investigated the negative impacts of microplastics on teleost fishes with very little or no evidence of their mechanism of action. This scenario entreats us to investigate the toxicities of nanopolystyrene in zebrafish oocyte with emphasis on the mechanism of action. In the present study, the cellular levels of mRNA transcripts of different genetic markers (such as: sod, gpx, nrf2, inos, ucp2, and atp6 (redox-sensitive markers); nfkβ, tnfα, il-10, ikβ, gdf9, and bmp15 (immune markers); gadd45, rad51, p53 and bcl2 (DNA damage and apoptotic)) have been quantified by real-time PCR after 6 h of incubation of isolated oocyte with different doses of nanopolystyrene viz. P0 (control i.e. no polystyrene in culture medium), P1 (100 ng/ml), and P2 (400 ng/ml). Results showed that both the treatment concentrations of nanopolystyrene induce oxidative stress with % DPPH = 30.75, 31.61, and 32.43% for P0, P1, and P2, respectively. Increase in oxidative stress in oocytes with increasing doses of nanopolystyrene was also observed in TBARS assay with MDA content 0.12 and 0.21 μM for P1 and P2, respectively as compaired to the control 0.08 μM. This increased oxidative stress can regulate the expression pattern (upregulation/downregulation) of selected genes leading to different toxic effects like - oxidative stress, immunotoxicity, and apoptosis in oocytes, which suggests the impairment of reproductive functions by nanopolystyrene.

Ca2+-mediated mitochondrial inner membrane permeabilization induces cell death independently of Bax and Bak

The ability of mitochondria to buffer a rapid rise in cytosolic Ca²⁺ is a hallmark of proper cell homeostasis. Here, we employed m-3M3FBS, a putative phospholipase C (PLC) agonist, to explore the relationships between intracellular Ca²⁺ imbalance, mitochondrial physiology, and cell death. m-3M3FBS induced a potent dose-dependent Ca²⁺ release from the endoplasmic reticulum (ER), followed by a rise in intra-mitochondrial Ca²⁺. When the latter exceeded the organelle buffering capacity, an abrupt mitochondrial inner membrane permeabilization (MIMP) occurred, releasing matrix contents into the cytosol. MIMP was followed by cell death that was independent of Bcl-2 family members and inhibitable by the intracellular Ca²⁺ chelator BAPTA-AM. Cyclosporin A (CsA), capable of blocking the mitochondrial permeability transition (MPT), completely prevented cell death induced by m-3M3FBS. However, CsA acted upstream of mitochondria by preventing Ca²⁺ release from ER stores. Therefore, loss of Ca²⁺ intracellular balance and mitochondrial Ca²⁺ overload followed by MIMP induced a cell death process that is distinct from Bcl-2 family-regulated mitochondrial outer membrane permeabilization (MOMP). Further, the inhibition of cell death by CsA or its analogues can be independent of effects on the MPT.

Response to Different Oxygen Partial Pressures and Evolution Analysis of Apoptosis-Related Genes in Plateau Zokor (Myospalax baileyi)

The plateau zokor (Myospalax baileyi) is a native species of the Qinghai–Tibet Plateau that spends its entire life underground in sealed burrows with hypoxic conditions. The present study aimed to assess the sequence characteristics of apoptosis-related genes and the response to different oxygen partial pressures (pO₂) in plateau zokor and Sprague-Dawley rats. The sequences of the p53-induced protein with a death domain (Pidd), p53-upregulated modulator of apoptosis (Puma), insulin-like growth factor binding protein 3 (Igfbp3), and apoptosis protease-activating factor 1 (Apaf1) were evaluated concerning homology and convergent evolution sites, and their mRNA levels were evaluated in different tissues under 14.13 (3,300 m) and 16.12 kPa (2,260 m) pO₂ conditions. Our results showed that, (1) the sequences of the apoptosis-related genes in plateau zokor were highly similar to those of Nannospalax galili, followed by Rattus norvegicus; (2). Pidd, Puma, Igfbp3, and Apaf1 of plateau zokor were found to have five, one, two, and five convergent sites in functional domains with N. galili, respectively. Lastly (3), under low pO₂, the expression of Pidd and Puma was downregulated in the lung of plateau zokors. In turn, Igfbp3 and Apaf1 were upregulated in the liver and lung, and Puma was upregulated in the skeletal muscle of plateau zokor under low pO₂. In Sprague-Dawley rats, low pO₂ downregulated Puma and Apaf1 expression in the liver and downregulated Igfbp3 and Puma in the lung and skeletal muscle separately. In contrast, low pO₂ upregulated Pidd expression in the liver and skeletal muscle of Sprague-Dawley rats. Overall, the expression patterns of Apaf1, Igfbp3, and Puma showed the opposite pattern in the liver, lung, and skeletal muscle, respectively, of plateau zokor as compared with Sprague-Dawley rats. In conclusion, for the long-time adaptation to hypoxic environments, Pidd, Puma, Igfbp3, and Apaf1 of plateau zokor underwent convergent evolution, which we believe may have led to upregulation of their levels under low oxygen partial pressures to induce apoptosis, so as to suppress tumorigenesis under hypoxic environments in plateau zokor.

Effect of intermittent fasting on saving zone of stasis in burn wounds in rats

BACKGROUND

Intermittent Fasting (IF) has proved to have various positive effects on life span, diseases, and healing of tissues in rodents. We evaluated the protective effect of fasting in maintaining the ischemic zones in burn wounds.

METHODS

In this study, 20 rats were divided into two groups where the IF rats were deprived of food for three months. Burn wounds were created by burn comb model on the back of all rats. On days 3 and 21 after injury, five rats in each group were euthanized whereby samples were collected for histopathological, immunohistochemical (Bcl2, P53 and VEGF), and biochemical (MDA, TAC, HP) evaluations.

RESULTS

Histopathological analysis revealed epithelial layer and zone of ischemia remained viable in the intermittent fasting group on day 3. On the 21st day, epithelialization, angiogenesis, inflammation, fibrocyte-fibroblast, and collagen density were different in the ischemic and necrotic zones between the control and intermittent fasting groups (p<0.05). We found no statistical differences in Bcl2, P53, VEGF, MDA, TAC, and HP on day 3 between the intermittent fasting and control groups.

CONCLUSIONS

Intermittent fasting before burn wounds reduces tissue damage caused by ischemia and enhanced the viability of cells in zone of stasis. It also accelerated wound healing by increasing epithelialization and collagen production in the skin and regulating inflammatory responses. This intervention appears to be related to better collagen arrangement and angiogenesis.

Salidroside Exerts Beneficial Effect on Testicular Ischemia-Reperfusion Injury in Rats

Testicular torsion-detorsion results in testicular ischemia-reperfusion injury, which is associated with overgeneration of reactive oxygen species. Salidroside, a major bioactive ingredient extracted from Rhodiola rosea, has strong antioxidant activity. The purpose of this study was to examine the effect of salidroside on testicular ischemia-reperfusion injury. Sixty rats were randomly separated into 3 experimental groups: group A = sham-operated control; group B = testicular ischemia-reperfusion; and group C = testicular ischemia-reperfusion treated with salidroside. The rats in the sham-operated control group received all surgical procedures except testicular torsion-detorsion. The testicular ischemia-reperfusion group underwent 2 hours of left testicular torsion followed by detorsion. The rats in the salidroside-treated group received the same surgical procedure as in testicular ischemia-reperfusion group, but salidroside was injected intraperitoneally at reperfusion. Testicular malondialdehyde content (a reliable index of reactive oxygen species) and protein expression of superoxide dismutase and catalase which are primary antioxidant enzymes in testes were measured at 4 hours after reperfusion. Testicular spermatogenesis was evaluated at 3 months after reperfusion. The malondialdehyde content increased significantly, while superoxide dismutase and catalase protein expression and testicular spermatogenesis reduced significantly in ipsilateral testes of testicular ischemia-reperfusion group, as compared with sham-operated control group. Therapy with salidroside significantly reduced malondialdehyde content and significantly enhanced superoxide dismutase and catalase protein expression and spermatogenesis in ipsilateral testes, as compared with testicular ischemia-reperfusion group. The present findings indicate that treatment with salidroside ameliorates testicular ischemia-reperfusion injury by reducing reactive oxygen species level by upregulating superoxide dismutase and catalase protein expression.

A Rheostat of Ceramide and Sphingosine-1-Phosphate as a Determinant of Oxidative Stress-Mediated Kidney Injury

Reactive oxygen species (ROS) modulate sphingolipid metabolism, including enzymes that generate ceramide and sphingosine-1-phosphate (S1P), and a ROS-antioxidant rheostat determines the metabolism of ceramide-S1P. ROS induce ceramide production by activating ceramide-producing enzymes, leading to apoptosis, while they inhibit S1P production, which promotes survival by suppressing sphingosine kinases (SphKs). A ceramide-S1P rheostat regulates ROS-induced mitochondrial dysfunction, apoptotic/anti-apoptotic Bcl-2 family proteins and signaling pathways, leading to apoptosis, survival, cell proliferation, inflammation and fibrosis in the kidney. Ceramide inhibits the mitochondrial respiration chain and induces ceramide channel formation and the closure of voltage-dependent anion channels, leading to mitochondrial dysfunction, altered Bcl-2 family protein expression, ROS generation and disturbed calcium homeostasis. This activates ceramide-induced signaling pathways, leading to apoptosis. These events are mitigated by S1P/S1P receptors (S1PRs) that restore mitochondrial function and activate signaling pathways. SphK1 promotes survival and cell proliferation and inhibits inflammation, while SphK2 has the opposite effect. However, both SphK1 and SphK2 promote fibrosis. Thus, a ceramide-SphKs/S1P rheostat modulates oxidant-induced kidney injury by affecting mitochondrial function, ROS production, Bcl-2 family proteins, calcium homeostasis and their downstream signaling pathways. This review will summarize the current evidence for a role of interaction between ROS-antioxidants and ceramide-SphKs/S1P and of a ceramide-SphKs/S1P rheostat in the regulation of oxidative stress-mediated kidney diseases.

Minocycline can reduce testicular apoptosis related to varicocele in male rats

The current research aimed to assess the impacts of Minocycline on varicocele-induced regulation of apoptotic-related genes and oxidative stress in the testis of adult Wistar rats. Thirty-two rats were divided into 4 groups: sham, varicocele (VcI), varicocele treated with Minocycline (VcI + Mno) for 56 days and healthy rats treated with minocycline (Mno). After 8 weeks, the oxidative stress markers levels in serum were investigated, afterwards, the level of Bax and Bcl-2 expression were assessed through 'immunocytochemistry' and RT-qPCR assays. Also, the rate of apoptosis was evaluated through the TUNEL method. Johnson's score, 'the width of epithelium' and 'seminiferous tubules diameter' were ameliorated in the VcI + Mno group in comparison with the Vcl group. Administration of Minocycline raised the 'Glutathione peroxidase' and 'Superoxide dismutase' levels in serum and declined the Malondialdehyde level in serum (p = 0.001). Furthermore, current study represented that minocycline reduced Bax and enhanced the expression of Bcl-2 gene and protein in comparison with the Vcl group (p < 0.05). In addition, Minocycline administration significantly declined the rate of apoptosis in germ cells (p < 0.05). Our study demonstrated that the administration of Minocycline could improve testicular injury in varicocele-induced rats by its antioxidant activity.

Genome-wide screening in the haploid system reveals Slc25a43 as a target gene of oxidative toxicity

Reactive oxygen species (ROS) are extensively assessed in physiological and pathological studies; however, the genes and mechanisms involved in antioxidant reactions are elusive. To address this knowledge gap, we used a forward genetic approach with mouse haploid embryonic stem cells (haESCs) to generate high-throughput mutant libraries, from which numerous oxidative stress-targeting genes were screened out. We performed proof-of-concept experiments to validate the potential inserted genes. Slc25a43 (one of the candidates) knockout (KO) ESCs presented reduced damage caused by ROS and higher cell viability when exposed to H₂O₂. Subsequently, ROS production and mitochondrial function analysis also confirmed that Slc25a43 was a main target gene of oxidative toxicity. In addition, we identified that KO of Slc25a43 activated mitochondria-related genes including Nlrx1 to protect ESCs from oxidative damage. Overall, our findings facilitated revealing target genes of oxidative stress and shed lights on the mechanism underlying oxidative death.

Acetylshikonin induces autophagy-dependent apoptosis through the key LKB1-AMPK and PI3K/Akt-regulated mTOR signalling pathways in HL-60 cells

Acetylshikonin (ASK) is a natural naphthoquinone derivative of traditional Chinese medicine Lithospermum erythrorhyzon. It has been reported that ASK has bactericidal, anti‐inflammatory and antitumour effects. However, whether ASK induces apoptosis and autophagy in acute myeloid leukaemia (AML) cells and the underlying mechanism are still unclear. Here, we explored the roles of apoptosis and autophagy in ASK‐induced cell death and the potential molecular mechanisms in human AML HL‐60 cells. The results demonstrated that ASK remarkably inhibited the cell proliferation, viability and induced apoptosis in HL‐60 cells through the mitochondrial pathway, and ASK promoted cell cycle arrest in the S‐phase. In addition, the increased formation of autophagosomes, the turnover from light chain 3B (LC3B) I to LC3B II and decrease of P62 suggested the induction of autophagy by ASK. Furthermore, ASK significantly decreased PI3K, phospho‐Akt and p‐p70S6K expression, while enhanced phospho‐AMP‐activated protein kinase (AMPK) and phospho‐liver kinase B1(LKB1) expression. The suppression of ASK‐induced the conversion from LC3B I to LC3B II caused by the application of inhibitors of AMPK (compound C) demonstrated that ASK‐induced autophagy depends on the LKB1/AMPK pathway. These data suggested that the autophagy induced by ASK were dependent on the activation of LKB1/AMPK signalling and suppression of PI3K/Akt/mTOR pathways. The cleavage of the apoptosis‐related markers caspase‐3 and caspase‐9 and the activity of caspase‐3 induced by ASK were markedly reduced by inhibitor of AMPK (compound C), an autophagy inhibitor 3‐methyladenine (3‐MA) and another autophagy inhibitor chloroquine (CQ). Taken together, our data reveal that ASK‐induced HL‐60 cell apoptosis is dependent on the activation of autophagy via the LKB1/AMPK and PI3K/Akt‐regulated mTOR signalling pathways.

PEGylation and antioxidant effects of a human glutathione peroxidase 1 mutant

Human glutathione peroxidase1 (hGPx1) is a good antioxidant and potential drug, but the limited availability and poor stability of hGPx1 have affected its development and application. To solve this problem, we prepared a hGPx1 mutant (GPx1M) with high activity in an Escherichia coli BL21(DE3)cys auxotrophic strain using a single protein production (SPP) system. In this study, the GPx1M was conjugated with methoxypolyethylene glycol-succinimidyl succinate (SS-mPEG, M_w = 5 kDa) chains to enhance its stability. SS-mPEG-GPx1M and GPx1M exhibited similar enzymatic activity and stability toward pH and temperature change, and in a few cases, SS-mPEG-GPx1M was discovered to widen the range of pH stability and increase the temperature stability. Lys 38 was confirmed as PEGylated site by liquid-mass spectrometry. H9c2 cardiomyoblast cells and Sprague-Dawley (SD) rats were used to evaluate the effects of GPx1M and SS-mPEG-GPx1M on preventing or alleviating adriamycin (ADR)-mediated cardiotoxicity, respectively. The results indicated that GPx1M and SS-mPEG-GPx1M had good antioxidant effects in vitro and in vivo, and the effect of SS-mPEG-GPx1M is more prominent than GPx1M in vivo. Thus, PEGylation might be a promising method for the application of GPx1M as an important antioxidant and potential drug.

Low oxygen environment and astaxanthin supplementation promote the developmental competence of bovine oocytes derived from early antral follicles during 8 days of in vitro growth in a gas-permeable culture device

We evaluated the effects of a constant low (5-5%) and modulated (5-20%) oxygen environments on the in vitro development of bovine oocyte-cumulus-granulosa cell complexes (OCGCs) cultured in the presence or absence of an antioxidant (astaxanthin: Ax). OCGCs were cultured in a gas permeable culture device for 8 days in 5-5% O₂ (±Ax) and 5-20% O₂ (±Ax) culture conditions. In the oxygen modulated culture conditions, the oxygen concentration was switched from 5% to 20% on day 4 of culture. Ax promoted the viability of OCGCs (P < 0.05), but both oxygen and Ax had a significant effect on ROS production levels by OCGCs (P < 0.05). Specifically, ROS levels were significantly lower and higher under 5-5% O₂ (+Ax) and 5-20% O₂ (-Ax) conditions, respectively (P < 0.05), with intermediate levels observed in the 5-5% O₂ (-Ax) and the 5-20% O₂ (+Ax) culture conditions. The steroidogenic pattern was characterized by increasing estradiol-17β but with constant progesterone production levels regardless of culture conditions, suggesting the inhibition of luteinization-like changes in granulosa cells. OCGCs cultured in the 5-20% O₂ (+Ax) had higher nuclear maturation rates (P < 0.05) that were similar to the oocytes grown in vivo. However, there was no clear difference in the subsequent cleavage rates among the 5-5% O₂ (±Ax) and the 5-20% O₂ (+Ax) culture conditions (P > 0.05). A constant low oxygen environment significantly promoted the blastocyst rates (P < 0.05); however, the presence of Ax in the 5-20% O₂ (+Ax) condition also promoted development similar to the OCGCs cultured in the 5-5% O₂ (-Ax) condition (P > 0.05). In conclusion, exposure of OCGCs to constant low oxygen or oxygen modulation in the presence of Ax promotes the healthy development of OCGCs during the 8-day IVG culture using the gas permeable culture device.

MicroRNAs and Diabetes Mellitus Type 1

Type 1 diabetes mellitus is a multifactorial, progressive, autoimmune disease with a strong genetic feature that can affect multiple organs, including the kidney, eyes, and nerves. Early detection of type 1 diabetes can help critically to avoid serious damages to these organs. MicroRNAs are small RNA molecules that act in post-transcriptional gene regulation by attaching to the complementary sequence in the 3'-untranslated region of their target genes. Alterations in the expression of microRNA coding genes are extensively reported in several diseases, such as type 1 diabetes. Presenting non-invasive biomarkers for early detection of type 1 diabetes by quantifying microRNAs gene expression level can be a significant step in biotechnology and medicine. This review discusses the area of microRNAs dysregulation in type 1 diabetes and affected molecular mechanisms involved in pancreatic islet cell formation and dysregulation in the expression of inflammatory elements as well as pro-inflammatory cytokines.

Antioxidant enzyme peroxiredoxin 5 regulates cyst growth and ciliogenesis via modulating Plk1 stability

Oxidative stress is emerging as a contributing factor to the homeostasis in cystic diseases. However, the role antioxidant enzymes play in the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD) remains elusive. Peroxiredoxin 5 (Prdx5) is an antioxidant enzyme that catalyzes the reduction of H2 O2 and alkyl hydroperoxide and plays an important role in different biological processes. In this study, we show that Prdx5 is downregulated in a PKD mutant mouse model and ADPKD patient kidneys. Knockdown of Prdx5 resulted in the formation of cysts in a three-dimensional mouse inner medullar collecting duct (IMCD) cell Matrigel culture system. The mechanisms of Prdx5 deficiency mediated cyst growth include: (1) induction of oxidative stress as indicated by increased mRNA expression of heme oxygenase-1, an oxidant stress marker; (2) activation of Erk, S6 and mTORC1, which contribute to cystic renal epithelial cell proliferation and cyst growth; (3) abnormal centrosome amplification and multipolar spindle formation which result in genome instability; (4) upregulation of Polo-like kinase 1 (Plk1) and Aurora kinase A, important mitotic kinases involved in cell proliferation and ciliogenesis; (5) impaired formation of primary cilia in mouse IMCD3 and retinal pigment epithelial cells, which could be rescued by inhibiting Plk1 activity; and (6) restraining the effect of Wnt3a and Wnt5a ligands on primary cilia in mouse IMCD3 cells, while regulating the activity of the canonical and non-canonical Wnt signaling in a separate cilia independent mechanism, respectively. Importantly, we found that targeting Plk1 with its inhibitor, volasertib, delayed cyst growth in Pkd1 conditional knockout mouse kidneys. Together, these findings indicate that Prdx5 is an important antioxidant that regulates cyst growth via diverse mechanisms, in particular, the Prdx5-Plk1 axis, and that induction and activation of Prdx5, alone or together with inhibition of Plk1, represent a promising strategy for combatting ADPKD.

In vitro and in vivo assessment of biocompatibility of AZ31 alloy as biliary stents: a preclinical approach

INTRODUCTION

Biomaterial technology due to its lack of or minimal side effects in tissues has great potential. Traditionally biomaterials used were cobalt-chromium, stainless steel and nitinol alloys. Biomaterials such as magnesium (Mg) and zinc (Zn) have good biocompatibility and consequently can be a potential material for medical implants. To date, the effects of AZ31 alloy stent on cell apoptosis are still unclear. The current investigation was designed to determine the effect of AZ31 alloy stent on necrosis and apoptosis of common bile duct (CBD) epithelial cells.

MATERIAL AND METHODS

We experimented with application of different concentrations of AZ31 alloy stent to primary mouse extrahepatic bile epithelial cells (MEBECs) and estimated the effect on apoptosis and necrotic cells. Apoptosis and pro-apoptosis expression were estimated through real-time PCR. For in vivo protocol, we used rabbits, implanted the AZ31 bile stent, and estimated its effect on the CBD. AZ31 (40%) concentration showed an effect on the apoptotic and necrotic cells.

RESULTS

Real-time PCR revealed that AZ31 (40%) concentration increased the apoptotic genes such as NF-κB, caspase-3, Bax and Bax/Bcl-2 ratio as compared to the control group. In the in vivo experiment, AZ31 alloy stents were implanted into the CBD and showed an effect on the alteration the hematological, hepatic and non-hepatic parameters.

CONCLUSIONS

To conclude, it can be stated that AZ31 induces apoptosis via alteration in genes including nuclear factor kappa-B (NF-κB), caspase-3, Bax and Bax/Bcl-2 ratio and improved the hematological, hepatic and non-hepatic parameters.

Citric Acid Promoting B Lymphocyte Differentiation and Anti-epithelial Cells Apoptosis Mediate the Protective Effects of Hermetia illucens Feed in ETEC Induced Piglets Diarrhea

Newborn piglets are prone to diarrhea after weaning as a result of changes in their environment and feed. Enterotoxigenic Escherichia coli (ETEC) K88 strain is a typical pathogen that causes diarrhea in such stage of piglets. Hermetia illucens larvae are widely used in livestock and poultry production because of their high nutritional value and immunoregulatory effects. This study aimed to evaluate the protective effects of H. illucens feed in protecting against ETEC induced diarrhea in piglets and to unravel the mechanisms of immune modulation and intestinal barrier maintenance. The results showed that after ETEC infection, citric acid in the serum of the groups fed on H. illucens larvae increased significantly, which stimulated macrophages to secrete cytokines that promote B lymphocyte differentiation, ultimately increasing the production of IgA and IgG in serum. Concomitantly, citric acid also had a positive effect on the intestinal barrier damaged due to ETEC infection by inhibiting the production of inflammatory cytokines, reducing the Bcl-2/Bax ratio, and promoting the expression of tight junction proteins. Correlation analysis showed that the increase of citric acid levels might be related to Massilia. Thus, citric acid derived from H. illucens larvae can improve the immune performance of weaned piglets and reduce ETEC-induced damage to the intestinal barrier in weaned piglets.

Seasonal cellular stress phenomena and phenotypic plasticity in land snail Helix lucorum populations from different altitudes

Temperature, a major abiotic environmental factor, regulates various physiological functions in land snails and therefore determines their biogeographical distribution. Thus, species with different distributions may present different thermal tolerance limits. Additionally, the intense reactivation of snail metabolic rate upon arousal from hibernation or estivation may provoke stress. Land snails, Helix lucorum, display a wide altitudinal distribution resulting in populations being exposed to different seasonal temperature variations. The aim of the present study was to investigate the expression of heat shock proteins (Hsps), mitogen activated protein kinases (MAPKs) and proteins that are related to apoptosis (Bcl-2, ubiquitin), that have 'cytoprotective' roles and are also considered to be reliable indicators of stress because of their crucial role in maintaining cellular homeostasis. These proteins were assessed in H. lucorum individuals from two different populations, one at Axios (sea level, 0 m) and the other at Kokkinopilos (Olympus, 1250 m), as well as after mutual population exchanges, in order to find out whether the different responses of these stress-related proteins depend solely on the environmental temperature. The results showed seasonally altered levels in all studied proteins in the hepatopancreas and foot of snails, both among different populations and between the same populations exposed to varying altitudes. However, individuals of the same population in their native habitat or acclimatized to a different habitat showed a relatively similar pattern of expression, supporting the induction of the specific proteins according to the life history of each species.

Mitophagy in Yeast: Decades of Research

Mitophagy, the selective degradation of mitochondria by autophagy, is one of the most important mechanisms of mitochondrial quality control, and its proper functioning is essential for cellular homeostasis. In this review, we describe the most important milestones achieved during almost 2 decades of research on yeasts, which shed light on the molecular mechanisms, regulation, and role of the Atg32 receptor in this process. We analyze the role of ROS in mitophagy and discuss the physiological roles of mitophagy in unicellular organisms, such as yeast; these roles are very different from those in mammals. Additionally, we discuss some of the different tools available for studying mitophagy.

Diosmetin inhibits cell growth and proliferation by regulating the cell cycle and lipid metabolism pathway in hepatocellular carcinoma

Diosmetin (DSM), a newly discovered natural flavonoid, found in citrus plants and olive leaves, has been reported to inhibit the progression of cancer when used as a food supplement. This study aimed to investigate DSM's anti-hepatocellular carcinoma (HCC) properties and possible molecular mechanisms. Hep3B and HCCLM3 cells were selected to evaluate the anti-HCC properties of DSM in vitro. RNA sequencing (RNA-seq) was used to identify the possible molecular targets and pathways. Gas chromatography-mass spectrometry (GC-MS) was used to evaluate the effect of DSM treatment on the primary metabolites of HCCLM3 cells. Tumor xenograft was performed in nude mice to examine the anti-HCC properties of DSM in vivo. The results showed that DSM inhibited the proliferation and migration of HCC cells in vitro in a dose-dependent manner. RNA-seq identified 4459 differentially expressed genes (DEGs) that were highly enriched in the cell cycle pathway. In addition, DSM regulated cell growth by arresting the cell cycle in the G1 phase by decreasing the expression of BCL2, CDK1, and CCND1. Furthermore, metabolomics analysis revealed that DSM interfered with the lipid metabolism pathway of HCC cells by significantly inhibiting the synthesis of metabolites, such as acetic acid, decanoic acid, glycerol, and L-proline. Subcutaneous tumor formation experiments revealed that DSM significantly reduced the tumor volume and weight when compared to the control. Immunohistochemical analysis further revealed that DSM treatment significantly decreased the expression of the proliferative marker KI67. Our findings demonstrated that DSM exhibited antitumor effects on HCC cells by inhibiting cell proliferation via cell cycle arrest and interfering with lipid metabolism.

Effect of mifepristone and lithospermum combination regimen on medical abortion in early pregnancy rats

OBJECTIVE

To investigate the optimal dose of mifepristone and lithospermum combination regimen on medical abortion in early pregnancy rats without increasing side effects.

STUDY DESIGN

Sixty sexually mature female Sprague Dawley (SD) rats with early pregnancy were randomly allocated into 10 groups, including a control group (treated with 0.5% CMC-Na) and nine experiments (treated with 1 mg/kg mifepristone, and 90, 180, 270, and 540 mg/kg lithospermum, and 90/180/270/540 mg/kg lithospermum +1 mg/kg mifepristone, respectively). The hormone levels, factors associated with endometrial bleeding, oxidative stress, and apoptotic proteins in the endometrium, were then investigated.

RESULTS

The results demonstrated that 540 mg/kg lithospermum plus 1 mg/kg mifepristone treatment significantly improved the abortion rate when compared with the control group. Compared with the 1 mg/kg mifepristone, 540 mg/kg lithospermum plus 1 mg/kg mifepristone treatment did not induce significant increase in factors associated with abnormal endometrial bleeding, such as matrix metalloproteinase-9 (MMP9). However, mifepristone and lithospermum combination regimen promoted the expression level of malondialdehyde (MDA), activated caspase 3, caspase 9 and Bax, meanwhile, reduced the expression of superoxide dismutase (SOD) and Bcl-2.

CONCLUSION

These findings provided strong evidence that mifepristone and lithospermum combination regimen can obtain satisfactory abortion effect without increasing the expression level of bleeding-related factors.

Membrane Depolarization and Apoptosis-Like Cell Death in an Alkaline Environment in the Rice Pathogen Burkholderia glumae

The rice pathogen Burkholderia glumae uses amino acids as a principal carbon source and thus produces ammonia in amino acid-rich culture medium such as Luria-Bertani (LB) broth. To counteract ammonia-mediated environmental alkaline toxicity, the bacterium produces a public good, oxalate, in a quorum sensing (QS)-dependent manner. QS mutants of B. glumae experience alkaline toxicity and may undergo cell death at the stationary phase when grown in LB medium. Here, we show that the cell-death processes of QS mutants due to alkaline environmental conditions are similar to the apoptosis-like cell death reported in other bacteria. Staining QS mutants with bis-(1,3-dibutylbarbituric acid)-trimethine oxonol revealed membrane depolarization. CellROX™ staining showed excessive generation of reactive oxygen species (ROS) in QS mutants. The expression of genes encoding HNH endonuclease (BGLU_1G15690), oligoribonuclease (BGLU_1G09120), ribonuclease E (BGLU_1G09400), and Hu-beta (BGLU_1G13530) was significantly elevated in QS mutants compared to that in wild-type BGR1, consistent with the degradation of cellular materials as observed under transmission electron microscopy (TEM). A homeostatic neutral pH was not attainable by QS mutants grown in LB broth or by wild-type BGR1 grown in an artificially amended alkaline environment. At an artificially adjusted alkaline pH, wild-type BGR1 underwent apoptosis-like cell death similar to that observed in QS mutants. These results show that environmental alkaline stress interferes with homeostatic neutral cellular pH, induces membrane depolarization, and causes apoptosis-like cell death in B. glumae.

Dysregulated Autophagy Leads to Oxidative Stress and Aberrant Expression of ABC Transporters in Women with Early Miscarriage

Early miscarriage (EMC) is a devastating obstetrical complication. ATP-binding cassette (ABC) transporters mediate cholesterol transfer across the placenta and enhance cell survival by effluxing substrates from target cells in the presence of stressors. Recent evidence reports an intricate interplay between autophagy and ABC transporters. We hypothesized that dysregulated autophagy and oxidative stress (OS) in the placenta leads to abnormal expression of membrane transporters contributing to poor pregnancy survival in EMC. We determined mRNA and protein expression of autophagy genes (Beclin-1/Bcl-2/LC3I/LC3II/p62) and ABC transporters (ABCA1/ABCG1/ABCG2) in placentae from EMC patients (n = 20), term controls (n = 19), first trimester (n = 6), and term controls (n = 5) controls. Oxidative/antioxidant status and biomarkers of oxidative damage were evaluated in maternal serum and placentae from EMC and healthy controls. In EMC, placental expression of LC3II/LC3I as well as of the key autophagy regulatory proteins Beclin-1 and Bcl-2 were reduced, whereas p62 was increased. Both in the serum and placentae of EMC patients, total OS was elevated reflected by increased oxidative damage markers (8-OHdG/malondialdehyde/carbonyl formation) accompanied by diminished levels of total antioxidant status, catalase, and total glutathione. Furthermore, we found reduced ABCG1 and increased ABCG2 expression. These findings suggest that a decreased autophagy status triggers Bcl-2-dependent OS leading to macromolecule damage in EMC placentae. The decreased expression of ABCG1 contributes to reduced cholesterol export to the growing fetus. Increasing ABCG2 expression could represent a protective feedback mechanism under inhibited autophagy conditions. In conclusion, dysregulated autophagy combined with increased oxidative toxicity and aberrant expression of placental ABC transporters affects materno-fetal health in EMC.

Functional Characterization of the Wheat Macrophage Migration Inhibitory Factor TaMIF1 in Wheat-Stripe Rust (Puccinia striiformis) Interaction

Simple Summary

There have been many breakthroughs in MIF function and mechanism investigation in vertebrates, but it has rarely been studied in plants. Here, we aimed to characterize the function of MIF in wheat and its potential role in Wheat-Stripe rust interaction. We showed that wheat MIF has some similarities with that MIF in vertebrates, such as subcellular localization in both the cytosol and nuclei, as well as significant tautomerase activity, and both can inhibit Bax-induced programmed cell death. In the wheat–Pst interaction, TaMIF1 is upregulated during Pst infection. Silencing TaMIF1 decreased Pst infection of wheat tissues, and the accumulation of ROS was increased in TaMIF1-silenced wheat leaves, which hinted that TaMIF1 mainly modulates the ROS signaling and then alters the subsequent immune responses. The function characterization of TaMIF1 provides significant insight into the role of MIFs across kingdoms and helpful in-depth functional mechanism analysis on these proteins.

Abstract

Macrophage migration inhibitory factor (MIF), named for its role in inhibiting macrophage/monocyte migration, has multiple functions in modulation of inflammation, cell proliferation, angiogenesis, and tumorigenesis in vertebrates. Although homologs of this gene can be found in plants, the function of MIF in plants remains obscure. Here, we characterized TaMIF1 in Triticum aestivum resembling the MIF secreted from Homo sapiens. Transcript analysis revealed that TaMIF1 responded to stripe rust infection of wheat and was upregulated during the infection stage. TaMIF1 was localized to both the cytosol and nuclei in wheat mesophyll protoplast. Additionally, TaMIF1 possessed significant tautomerase activity, indicating conservation of MIFs across kingdoms. Agrobacterium tumefaciens infiltration assay demonstrated that TaMIF1 was capable of suppressing programmed cell death hinting its role in plant immunity. Heterologous expression of TaMIF1 increased fission yeast sensitivity to oxidative stress. Silencing TaMIF1 decreased the susceptibility of wheat to Pst seemingly through increasing reactive oxygen species accumulation. In conclusion, functions of the TaMIF1 were investigated in this study, which provides significant insight into understanding the role of MIFs across kingdoms.

Cytotoxic effects of dental calculus particles and freeze-dried Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum on HSC-2 oral epithelial cells and THP-1 macrophages

BACKGROUND

Periodontitis is an inflammatory disease initiated by dental deposits. Microorganisms in the dental biofilm induce cell death in epithelial cells, contributing to the breakdown of epithelial barrier function. Recently, dental calculus has also been implicated in pyroptotic cell death in oral epithelium. We analyzed the cytotoxic effects of dental calculus and freeze-dried periodontopathic bacteria on oral epithelial cells and macrophages.

METHODS

HSC-2 (human oral squamous carcinoma cells) and phorbol 12-myristate 13-acetate-differentiated THP-1 macrophages were exposed to dental calculus or one of two species of freeze-dried bacterium, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum. Following incubation for 24 hours, we measured cytotoxicity via lactate dehydrogenase release. Cells were then incubated with glyburide, an NLRP3 inflammasome inhibitor, to assess the potential role of pyroptosis. We also conducted a permeability assay to analyze the effects on epithelial barrier function.

RESULTS

Dental calculus induced dose-dependent cell death in HSC-2 cells, whereas cell death induced by freeze-dried bacteria was insignificant. Conversely, freeze-dried bacteria induced more cell death than dental calculus in THP-1 macrophages. Cell death induced by dental calculus but not by freeze-dried bacteria was inhibited by glyburide, indicating that these are different types of cell death. In the permeability assays, dental calculus but not freeze-dried bacteria attenuated the barrier function of HSC-2 cell monolayers.

CONCLUSION

Due to the low sensitivity of HSC-2 cells to microbial cytotoxicity, dental calculus had stronger cytotoxic effects on HSC-2 cell monolayers than freeze-dried A. actinomycetemcomitans and F. nucleatum, suggesting that it plays a critical role in the breakdown of crevicular/pocket epithelium integrity.

Diffusion tensor imaging of the hippocampus reflects the severity of hippocampal injury induced by global cerebral ischemia/reperfusion injury

At present, predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury (GCI/RI) is a clinical problem. After such an injury, clinical indicators that can directly reflect neurological dysfunction are lacking. The change in hippocampal microstructure is the key to memory formation and consolidation. Diffusion tensor imaging is a highly sensitive tool for visualizing injury to hippocampal microstructure. Although hippocampal microstructure, brain-derived neurotrophic factor (BDNF), and tropomyosin-related kinase B (TrkB) levels are closely related to nerve injury and the repair process after GCI/RI, whether these indicators can reflect the severity of such hippocampal injury remains unknown. To address this issue, we established rat models of GCI/RI using the four-vessel occlusion method. Diffusion tensor imaging parameters, BDNF, and TrkB levels were correlated with modified neurological severity scores. The results revealed that after GCI/RI, while neurological function was not related to BDNF and TrkB levels, it was related to hippocampal fractional anisotropy. These findings suggest that hippocampal fractional anisotropy can reflect the severity of hippocampal injury after global GCI/RI. The study was approved by the Institutional Animal Care and Use Committee of Capital Medical University, China (approval No. AEEI-2015-139) on November 9, 2015.

Dexmedetomidine Ameliorates Postoperative Cognitive Dysfunction in Aged Mice

Neuroinflammation and oxidative stress coexist and interact in the progression of postoperative cognitive dysfunction (POCD) and other neurodegenerative disease. Mounting studies reveal that Dexmedetomidine (Dex) possesses anti-inflammatory and antioxidant properties. Nevertheless, whether Dex exerts neuroprotective effect on the cognitive sequelae of oxidative stress and inflammatory process remains unclear. A mouse model of abdominal exploratory laparotomy-induced cognitive dysfunction was employed to explore the underlying mechanism of neuroprotective effects exerted by Dex in POCD. Aged mice were treated with Dex (20 µg/kg) 20 min prior to surgery. Open field test (OFT) and Morris water maze (MWM) were employed to examine the cognitive function on postoperative day 3 (POD 3) or POD 7. In the present study, mice underwent surgery exhibited cognitive impairment without altering spontaneous locomotor activity, while the surgery-induced cognitive impairment could be alleviated by Dex pretreatment. Dex inhibited surgery-induced pro-inflammatory cytokines accumulation and microglial activation in the hippocampi of mice. Furthermore, Dex decreased MDA levels, enhanced SOD activity, modulated CDK5 activity and increased BDNF expression in the hippocampus. In addition, Dex remarkably reduced the surgery-induced increased ratio of Bax/Bcl-2 and apoptotic neurons in the hippocampi of aged mice. Collectively, our study provides evidence that Dex may exert neuroprotective effects against surgery-induced cognitive impairment through mechanisms involving its anti-inflammatory and antioxidant properties, as well as the suppression on the mitochondrial permeability transition pore and apoptosis-related pathway.